diff --git a/src/kernel/linux/v4.14/fs/f2fs/Kconfig b/src/kernel/linux/v4.14/fs/f2fs/Kconfig
new file mode 100644
index 0000000..378c221
--- /dev/null
+++ b/src/kernel/linux/v4.14/fs/f2fs/Kconfig
@@ -0,0 +1,104 @@
+config F2FS_FS
+	tristate "F2FS filesystem support"
+	depends on BLOCK
+	select CRYPTO
+	select CRYPTO_CRC32
+	help
+	  F2FS is based on Log-structured File System (LFS), which supports
+	  versatile "flash-friendly" features. The design has been focused on
+	  addressing the fundamental issues in LFS, which are snowball effect
+	  of wandering tree and high cleaning overhead.
+
+	  Since flash-based storages show different characteristics according to
+	  the internal geometry or flash memory management schemes aka FTL, F2FS
+	  and tools support various parameters not only for configuring on-disk
+	  layout, but also for selecting allocation and cleaning algorithms.
+
+	  If unsure, say N.
+
+config F2FS_STAT_FS
+	bool "F2FS Status Information"
+	depends on F2FS_FS && DEBUG_FS
+	default y
+	help
+	  /sys/kernel/debug/f2fs/ contains information about all the partitions
+	  mounted as f2fs. Each file shows the whole f2fs information.
+
+	  /sys/kernel/debug/f2fs/status includes:
+	    - major filesystem information managed by f2fs currently
+	    - average SIT information about whole segments
+	    - current memory footprint consumed by f2fs.
+
+config F2FS_FS_XATTR
+	bool "F2FS extended attributes"
+	depends on F2FS_FS
+	default y
+	help
+	  Extended attributes are name:value pairs associated with inodes by
+	  the kernel or by users (see the attr(5) manual page, or visit
+	  <http://acl.bestbits.at/> for details).
+
+	  If unsure, say N.
+
+config F2FS_FS_POSIX_ACL
+	bool "F2FS Access Control Lists"
+	depends on F2FS_FS_XATTR
+	select FS_POSIX_ACL
+	default y
+	help
+	  Posix Access Control Lists (ACLs) support permissions for users and
+	  groups beyond the owner/group/world scheme.
+
+	  To learn more about Access Control Lists, visit the POSIX ACLs for
+	  Linux website <http://acl.bestbits.at/>.
+
+	  If you don't know what Access Control Lists are, say N
+
+config F2FS_FS_SECURITY
+	bool "F2FS Security Labels"
+	depends on F2FS_FS_XATTR
+	help
+	  Security labels provide an access control facility to support Linux
+	  Security Models (LSMs) accepted by AppArmor, SELinux, Smack and TOMOYO
+	  Linux. This option enables an extended attribute handler for file
+	  security labels in the f2fs filesystem, so that it requires enabling
+	  the extended attribute support in advance.
+
+	  If you are not using a security module, say N.
+
+config F2FS_CHECK_FS
+	bool "F2FS consistency checking feature"
+	depends on F2FS_FS
+	help
+	  Enables BUG_ONs which check the filesystem consistency in runtime.
+
+	  If you want to improve the performance, say N.
+
+config F2FS_FS_ENCRYPTION
+	bool "F2FS Encryption"
+	depends on F2FS_FS
+	depends on F2FS_FS_XATTR
+	select FS_ENCRYPTION
+	help
+	  Enable encryption of f2fs files and directories.  This
+	  feature is similar to ecryptfs, but it is more memory
+	  efficient since it avoids caching the encrypted and
+	  decrypted pages in the page cache.
+
+config F2FS_IO_TRACE
+	bool "F2FS IO tracer"
+	depends on F2FS_FS
+	depends on FUNCTION_TRACER
+	help
+	  F2FS IO trace is based on a function trace, which gathers process
+	  information and block IO patterns in the filesystem level.
+
+	  If unsure, say N.
+
+config F2FS_FAULT_INJECTION
+	bool "F2FS fault injection facility"
+	depends on F2FS_FS
+	help
+	  Test F2FS to inject faults such as ENOMEM, ENOSPC, and so on.
+
+	  If unsure, say N.
diff --git a/src/kernel/linux/v4.14/fs/f2fs/Makefile b/src/kernel/linux/v4.14/fs/f2fs/Makefile
new file mode 100644
index 0000000..776c4b9
--- /dev/null
+++ b/src/kernel/linux/v4.14/fs/f2fs/Makefile
@@ -0,0 +1,10 @@
+# SPDX-License-Identifier: GPL-2.0
+obj-$(CONFIG_F2FS_FS) += f2fs.o
+
+f2fs-y		:= dir.o file.o inode.o namei.o hash.o super.o inline.o
+f2fs-y		+= checkpoint.o gc.o data.o node.o segment.o recovery.o
+f2fs-y		+= shrinker.o extent_cache.o sysfs.o
+f2fs-$(CONFIG_F2FS_STAT_FS) += debug.o
+f2fs-$(CONFIG_F2FS_FS_XATTR) += xattr.o
+f2fs-$(CONFIG_F2FS_FS_POSIX_ACL) += acl.o
+f2fs-$(CONFIG_F2FS_IO_TRACE) += trace.o
diff --git a/src/kernel/linux/v4.14/fs/f2fs/acl.c b/src/kernel/linux/v4.14/fs/f2fs/acl.c
new file mode 100644
index 0000000..b9fe937
--- /dev/null
+++ b/src/kernel/linux/v4.14/fs/f2fs/acl.c
@@ -0,0 +1,408 @@
+/*
+ * fs/f2fs/acl.c
+ *
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ *             http://www.samsung.com/
+ *
+ * Portions of this code from linux/fs/ext2/acl.c
+ *
+ * Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/f2fs_fs.h>
+#include "f2fs.h"
+#include "xattr.h"
+#include "acl.h"
+
+static inline size_t f2fs_acl_size(int count)
+{
+	if (count <= 4) {
+		return sizeof(struct f2fs_acl_header) +
+			count * sizeof(struct f2fs_acl_entry_short);
+	} else {
+		return sizeof(struct f2fs_acl_header) +
+			4 * sizeof(struct f2fs_acl_entry_short) +
+			(count - 4) * sizeof(struct f2fs_acl_entry);
+	}
+}
+
+static inline int f2fs_acl_count(size_t size)
+{
+	ssize_t s;
+	size -= sizeof(struct f2fs_acl_header);
+	s = size - 4 * sizeof(struct f2fs_acl_entry_short);
+	if (s < 0) {
+		if (size % sizeof(struct f2fs_acl_entry_short))
+			return -1;
+		return size / sizeof(struct f2fs_acl_entry_short);
+	} else {
+		if (s % sizeof(struct f2fs_acl_entry))
+			return -1;
+		return s / sizeof(struct f2fs_acl_entry) + 4;
+	}
+}
+
+static struct posix_acl *f2fs_acl_from_disk(const char *value, size_t size)
+{
+	int i, count;
+	struct posix_acl *acl;
+	struct f2fs_acl_header *hdr = (struct f2fs_acl_header *)value;
+	struct f2fs_acl_entry *entry = (struct f2fs_acl_entry *)(hdr + 1);
+	const char *end = value + size;
+
+	if (hdr->a_version != cpu_to_le32(F2FS_ACL_VERSION))
+		return ERR_PTR(-EINVAL);
+
+	count = f2fs_acl_count(size);
+	if (count < 0)
+		return ERR_PTR(-EINVAL);
+	if (count == 0)
+		return NULL;
+
+	acl = posix_acl_alloc(count, GFP_NOFS);
+	if (!acl)
+		return ERR_PTR(-ENOMEM);
+
+	for (i = 0; i < count; i++) {
+
+		if ((char *)entry > end)
+			goto fail;
+
+		acl->a_entries[i].e_tag  = le16_to_cpu(entry->e_tag);
+		acl->a_entries[i].e_perm = le16_to_cpu(entry->e_perm);
+
+		switch (acl->a_entries[i].e_tag) {
+		case ACL_USER_OBJ:
+		case ACL_GROUP_OBJ:
+		case ACL_MASK:
+		case ACL_OTHER:
+			entry = (struct f2fs_acl_entry *)((char *)entry +
+					sizeof(struct f2fs_acl_entry_short));
+			break;
+
+		case ACL_USER:
+			acl->a_entries[i].e_uid =
+				make_kuid(&init_user_ns,
+						le32_to_cpu(entry->e_id));
+			entry = (struct f2fs_acl_entry *)((char *)entry +
+					sizeof(struct f2fs_acl_entry));
+			break;
+		case ACL_GROUP:
+			acl->a_entries[i].e_gid =
+				make_kgid(&init_user_ns,
+						le32_to_cpu(entry->e_id));
+			entry = (struct f2fs_acl_entry *)((char *)entry +
+					sizeof(struct f2fs_acl_entry));
+			break;
+		default:
+			goto fail;
+		}
+	}
+	if ((char *)entry != end)
+		goto fail;
+	return acl;
+fail:
+	posix_acl_release(acl);
+	return ERR_PTR(-EINVAL);
+}
+
+static void *f2fs_acl_to_disk(struct f2fs_sb_info *sbi,
+				const struct posix_acl *acl, size_t *size)
+{
+	struct f2fs_acl_header *f2fs_acl;
+	struct f2fs_acl_entry *entry;
+	int i;
+
+	f2fs_acl = f2fs_kmalloc(sbi, sizeof(struct f2fs_acl_header) +
+			acl->a_count * sizeof(struct f2fs_acl_entry),
+			GFP_NOFS);
+	if (!f2fs_acl)
+		return ERR_PTR(-ENOMEM);
+
+	f2fs_acl->a_version = cpu_to_le32(F2FS_ACL_VERSION);
+	entry = (struct f2fs_acl_entry *)(f2fs_acl + 1);
+
+	for (i = 0; i < acl->a_count; i++) {
+
+		entry->e_tag  = cpu_to_le16(acl->a_entries[i].e_tag);
+		entry->e_perm = cpu_to_le16(acl->a_entries[i].e_perm);
+
+		switch (acl->a_entries[i].e_tag) {
+		case ACL_USER:
+			entry->e_id = cpu_to_le32(
+					from_kuid(&init_user_ns,
+						acl->a_entries[i].e_uid));
+			entry = (struct f2fs_acl_entry *)((char *)entry +
+					sizeof(struct f2fs_acl_entry));
+			break;
+		case ACL_GROUP:
+			entry->e_id = cpu_to_le32(
+					from_kgid(&init_user_ns,
+						acl->a_entries[i].e_gid));
+			entry = (struct f2fs_acl_entry *)((char *)entry +
+					sizeof(struct f2fs_acl_entry));
+			break;
+		case ACL_USER_OBJ:
+		case ACL_GROUP_OBJ:
+		case ACL_MASK:
+		case ACL_OTHER:
+			entry = (struct f2fs_acl_entry *)((char *)entry +
+					sizeof(struct f2fs_acl_entry_short));
+			break;
+		default:
+			goto fail;
+		}
+	}
+	*size = f2fs_acl_size(acl->a_count);
+	return (void *)f2fs_acl;
+
+fail:
+	kfree(f2fs_acl);
+	return ERR_PTR(-EINVAL);
+}
+
+static struct posix_acl *__f2fs_get_acl(struct inode *inode, int type,
+						struct page *dpage)
+{
+	int name_index = F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT;
+	void *value = NULL;
+	struct posix_acl *acl;
+	int retval;
+
+	if (type == ACL_TYPE_ACCESS)
+		name_index = F2FS_XATTR_INDEX_POSIX_ACL_ACCESS;
+
+	retval = f2fs_getxattr(inode, name_index, "", NULL, 0, dpage);
+	if (retval > 0) {
+		value = f2fs_kmalloc(F2FS_I_SB(inode), retval, GFP_F2FS_ZERO);
+		if (!value)
+			return ERR_PTR(-ENOMEM);
+		retval = f2fs_getxattr(inode, name_index, "", value,
+							retval, dpage);
+	}
+
+	if (retval > 0)
+		acl = f2fs_acl_from_disk(value, retval);
+	else if (retval == -ENODATA)
+		acl = NULL;
+	else
+		acl = ERR_PTR(retval);
+	kfree(value);
+
+	return acl;
+}
+
+struct posix_acl *f2fs_get_acl(struct inode *inode, int type)
+{
+	return __f2fs_get_acl(inode, type, NULL);
+}
+
+static int __f2fs_set_acl(struct inode *inode, int type,
+			struct posix_acl *acl, struct page *ipage)
+{
+	int name_index;
+	void *value = NULL;
+	size_t size = 0;
+	int error;
+	umode_t mode = inode->i_mode;
+
+	switch (type) {
+	case ACL_TYPE_ACCESS:
+		name_index = F2FS_XATTR_INDEX_POSIX_ACL_ACCESS;
+		if (acl && !ipage) {
+			error = posix_acl_update_mode(inode, &mode, &acl);
+			if (error)
+				return error;
+			set_acl_inode(inode, mode);
+		}
+		break;
+
+	case ACL_TYPE_DEFAULT:
+		name_index = F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT;
+		if (!S_ISDIR(inode->i_mode))
+			return acl ? -EACCES : 0;
+		break;
+
+	default:
+		return -EINVAL;
+	}
+
+	if (acl) {
+		value = f2fs_acl_to_disk(F2FS_I_SB(inode), acl, &size);
+		if (IS_ERR(value)) {
+			clear_inode_flag(inode, FI_ACL_MODE);
+			return PTR_ERR(value);
+		}
+	}
+
+	error = f2fs_setxattr(inode, name_index, "", value, size, ipage, 0);
+
+	kfree(value);
+	if (!error)
+		set_cached_acl(inode, type, acl);
+
+	clear_inode_flag(inode, FI_ACL_MODE);
+	return error;
+}
+
+int f2fs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
+{
+	if (unlikely(f2fs_cp_error(F2FS_I_SB(inode))))
+		return -EIO;
+
+	return __f2fs_set_acl(inode, type, acl, NULL);
+}
+
+/*
+ * Most part of f2fs_acl_clone, f2fs_acl_create_masq, f2fs_acl_create
+ * are copied from posix_acl.c
+ */
+static struct posix_acl *f2fs_acl_clone(const struct posix_acl *acl,
+							gfp_t flags)
+{
+	struct posix_acl *clone = NULL;
+
+	if (acl) {
+		int size = sizeof(struct posix_acl) + acl->a_count *
+				sizeof(struct posix_acl_entry);
+		clone = kmemdup(acl, size, flags);
+		if (clone)
+			refcount_set(&clone->a_refcount, 1);
+	}
+	return clone;
+}
+
+static int f2fs_acl_create_masq(struct posix_acl *acl, umode_t *mode_p)
+{
+	struct posix_acl_entry *pa, *pe;
+	struct posix_acl_entry *group_obj = NULL, *mask_obj = NULL;
+	umode_t mode = *mode_p;
+	int not_equiv = 0;
+
+	/* assert(atomic_read(acl->a_refcount) == 1); */
+
+	FOREACH_ACL_ENTRY(pa, acl, pe) {
+		switch(pa->e_tag) {
+		case ACL_USER_OBJ:
+			pa->e_perm &= (mode >> 6) | ~S_IRWXO;
+			mode &= (pa->e_perm << 6) | ~S_IRWXU;
+			break;
+
+		case ACL_USER:
+		case ACL_GROUP:
+			not_equiv = 1;
+			break;
+
+		case ACL_GROUP_OBJ:
+			group_obj = pa;
+			break;
+
+		case ACL_OTHER:
+			pa->e_perm &= mode | ~S_IRWXO;
+			mode &= pa->e_perm | ~S_IRWXO;
+			break;
+
+		case ACL_MASK:
+			mask_obj = pa;
+			not_equiv = 1;
+			break;
+
+		default:
+			return -EIO;
+		}
+	}
+
+	if (mask_obj) {
+		mask_obj->e_perm &= (mode >> 3) | ~S_IRWXO;
+		mode &= (mask_obj->e_perm << 3) | ~S_IRWXG;
+	} else {
+		if (!group_obj)
+			return -EIO;
+		group_obj->e_perm &= (mode >> 3) | ~S_IRWXO;
+		mode &= (group_obj->e_perm << 3) | ~S_IRWXG;
+	}
+
+	*mode_p = (*mode_p & ~S_IRWXUGO) | mode;
+        return not_equiv;
+}
+
+static int f2fs_acl_create(struct inode *dir, umode_t *mode,
+		struct posix_acl **default_acl, struct posix_acl **acl,
+		struct page *dpage)
+{
+	struct posix_acl *p;
+	struct posix_acl *clone;
+	int ret;
+
+	*acl = NULL;
+	*default_acl = NULL;
+
+	if (S_ISLNK(*mode) || !IS_POSIXACL(dir))
+		return 0;
+
+	p = __f2fs_get_acl(dir, ACL_TYPE_DEFAULT, dpage);
+	if (!p || p == ERR_PTR(-EOPNOTSUPP)) {
+		*mode &= ~current_umask();
+		return 0;
+	}
+	if (IS_ERR(p))
+		return PTR_ERR(p);
+
+	clone = f2fs_acl_clone(p, GFP_NOFS);
+	if (!clone) {
+		ret = -ENOMEM;
+		goto release_acl;
+	}
+
+	ret = f2fs_acl_create_masq(clone, mode);
+	if (ret < 0)
+		goto release_clone;
+
+	if (ret == 0)
+		posix_acl_release(clone);
+	else
+		*acl = clone;
+
+	if (!S_ISDIR(*mode))
+		posix_acl_release(p);
+	else
+		*default_acl = p;
+
+	return 0;
+
+release_clone:
+	posix_acl_release(clone);
+release_acl:
+	posix_acl_release(p);
+	return ret;
+}
+
+int f2fs_init_acl(struct inode *inode, struct inode *dir, struct page *ipage,
+							struct page *dpage)
+{
+	struct posix_acl *default_acl = NULL, *acl = NULL;
+	int error = 0;
+
+	error = f2fs_acl_create(dir, &inode->i_mode, &default_acl, &acl, dpage);
+	if (error)
+		return error;
+
+	f2fs_mark_inode_dirty_sync(inode, true);
+
+	if (default_acl) {
+		error = __f2fs_set_acl(inode, ACL_TYPE_DEFAULT, default_acl,
+				       ipage);
+		posix_acl_release(default_acl);
+	}
+	if (acl) {
+		if (!error)
+			error = __f2fs_set_acl(inode, ACL_TYPE_ACCESS, acl,
+					       ipage);
+		posix_acl_release(acl);
+	}
+
+	return error;
+}
diff --git a/src/kernel/linux/v4.14/fs/f2fs/acl.h b/src/kernel/linux/v4.14/fs/f2fs/acl.h
new file mode 100644
index 0000000..2c68518
--- /dev/null
+++ b/src/kernel/linux/v4.14/fs/f2fs/acl.h
@@ -0,0 +1,53 @@
+/*
+ * fs/f2fs/acl.h
+ *
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ *             http://www.samsung.com/
+ *
+ * Portions of this code from linux/fs/ext2/acl.h
+ *
+ * Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#ifndef __F2FS_ACL_H__
+#define __F2FS_ACL_H__
+
+#include <linux/posix_acl_xattr.h>
+
+#define F2FS_ACL_VERSION	0x0001
+
+struct f2fs_acl_entry {
+	__le16 e_tag;
+	__le16 e_perm;
+	__le32 e_id;
+};
+
+struct f2fs_acl_entry_short {
+	__le16 e_tag;
+	__le16 e_perm;
+};
+
+struct f2fs_acl_header {
+	__le32 a_version;
+};
+
+#ifdef CONFIG_F2FS_FS_POSIX_ACL
+
+extern struct posix_acl *f2fs_get_acl(struct inode *, int);
+extern int f2fs_set_acl(struct inode *, struct posix_acl *, int);
+extern int f2fs_init_acl(struct inode *, struct inode *, struct page *,
+							struct page *);
+#else
+#define f2fs_get_acl	NULL
+#define f2fs_set_acl	NULL
+
+static inline int f2fs_init_acl(struct inode *inode, struct inode *dir,
+				struct page *ipage, struct page *dpage)
+{
+	return 0;
+}
+#endif
+#endif /* __F2FS_ACL_H__ */
diff --git a/src/kernel/linux/v4.14/fs/f2fs/checkpoint.c b/src/kernel/linux/v4.14/fs/f2fs/checkpoint.c
new file mode 100644
index 0000000..60f57c2
--- /dev/null
+++ b/src/kernel/linux/v4.14/fs/f2fs/checkpoint.c
@@ -0,0 +1,1532 @@
+/*
+ * fs/f2fs/checkpoint.c
+ *
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ *             http://www.samsung.com/
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/fs.h>
+#include <linux/bio.h>
+#include <linux/mpage.h>
+#include <linux/writeback.h>
+#include <linux/blkdev.h>
+#include <linux/f2fs_fs.h>
+#include <linux/pagevec.h>
+#include <linux/swap.h>
+
+#include "f2fs.h"
+#include "node.h"
+#include "segment.h"
+#include "trace.h"
+#include <trace/events/f2fs.h>
+
+static struct kmem_cache *ino_entry_slab;
+struct kmem_cache *inode_entry_slab;
+
+void f2fs_stop_checkpoint(struct f2fs_sb_info *sbi, bool end_io)
+{
+	set_ckpt_flags(sbi, CP_ERROR_FLAG);
+	if (!end_io)
+		f2fs_flush_merged_writes(sbi);
+}
+
+/*
+ * We guarantee no failure on the returned page.
+ */
+struct page *grab_meta_page(struct f2fs_sb_info *sbi, pgoff_t index)
+{
+	struct address_space *mapping = META_MAPPING(sbi);
+	struct page *page = NULL;
+repeat:
+	page = f2fs_grab_cache_page(mapping, index, false);
+	if (!page) {
+		cond_resched();
+		goto repeat;
+	}
+	f2fs_wait_on_page_writeback(page, META, true);
+	if (!PageUptodate(page))
+		SetPageUptodate(page);
+	return page;
+}
+
+/*
+ * We guarantee no failure on the returned page.
+ */
+static struct page *__get_meta_page(struct f2fs_sb_info *sbi, pgoff_t index,
+							bool is_meta)
+{
+	struct address_space *mapping = META_MAPPING(sbi);
+	struct page *page;
+	struct f2fs_io_info fio = {
+		.sbi = sbi,
+		.type = META,
+		.op = REQ_OP_READ,
+		.op_flags = REQ_META | REQ_PRIO,
+		.old_blkaddr = index,
+		.new_blkaddr = index,
+		.encrypted_page = NULL,
+		.is_meta = is_meta,
+	};
+
+	if (unlikely(!is_meta))
+		fio.op_flags &= ~REQ_META;
+repeat:
+	page = f2fs_grab_cache_page(mapping, index, false);
+	if (!page) {
+		cond_resched();
+		goto repeat;
+	}
+	if (PageUptodate(page))
+		goto out;
+
+	fio.page = page;
+
+	if (f2fs_submit_page_bio(&fio)) {
+		memset(page_address(page), 0, PAGE_SIZE);
+		f2fs_stop_checkpoint(sbi, false);
+		f2fs_bug_on(sbi, 1);
+		return page;
+	}
+
+	lock_page(page);
+	if (unlikely(page->mapping != mapping)) {
+		f2fs_put_page(page, 1);
+		goto repeat;
+	}
+
+	/*
+	 * if there is any IO error when accessing device, make our filesystem
+	 * readonly and make sure do not write checkpoint with non-uptodate
+	 * meta page.
+	 */
+	if (unlikely(!PageUptodate(page)))
+		f2fs_stop_checkpoint(sbi, false);
+out:
+	return page;
+}
+
+struct page *get_meta_page(struct f2fs_sb_info *sbi, pgoff_t index)
+{
+	return __get_meta_page(sbi, index, true);
+}
+
+/* for POR only */
+struct page *get_tmp_page(struct f2fs_sb_info *sbi, pgoff_t index)
+{
+	return __get_meta_page(sbi, index, false);
+}
+
+bool f2fs_is_valid_blkaddr(struct f2fs_sb_info *sbi,
+					block_t blkaddr, int type)
+{
+	switch (type) {
+	case META_NAT:
+		break;
+	case META_SIT:
+		if (unlikely(blkaddr >= SIT_BLK_CNT(sbi)))
+			return false;
+		break;
+	case META_SSA:
+		if (unlikely(blkaddr >= MAIN_BLKADDR(sbi) ||
+			blkaddr < SM_I(sbi)->ssa_blkaddr))
+			return false;
+		break;
+	case META_CP:
+		if (unlikely(blkaddr >= SIT_I(sbi)->sit_base_addr ||
+			blkaddr < __start_cp_addr(sbi)))
+			return false;
+		break;
+	case META_POR:
+	case DATA_GENERIC:
+		if (unlikely(blkaddr >= MAX_BLKADDR(sbi) ||
+			blkaddr < MAIN_BLKADDR(sbi))) {
+			if (type == DATA_GENERIC) {
+				f2fs_msg(sbi->sb, KERN_WARNING,
+					"access invalid blkaddr:%u", blkaddr);
+				WARN_ON(1);
+			}
+			return false;
+		}
+		break;
+	case META_GENERIC:
+		if (unlikely(blkaddr < SEG0_BLKADDR(sbi) ||
+			blkaddr >= MAIN_BLKADDR(sbi)))
+			return false;
+		break;
+	default:
+		BUG();
+	}
+
+	return true;
+}
+
+/*
+ * Readahead CP/NAT/SIT/SSA pages
+ */
+int ra_meta_pages(struct f2fs_sb_info *sbi, block_t start, int nrpages,
+							int type, bool sync)
+{
+	struct page *page;
+	block_t blkno = start;
+	struct f2fs_io_info fio = {
+		.sbi = sbi,
+		.type = META,
+		.op = REQ_OP_READ,
+		.op_flags = sync ? (REQ_META | REQ_PRIO) : REQ_RAHEAD,
+		.encrypted_page = NULL,
+		.in_list = false,
+		.is_meta = (type != META_POR),
+	};
+	struct blk_plug plug;
+
+	if (unlikely(type == META_POR))
+		fio.op_flags &= ~REQ_META;
+
+	blk_start_plug(&plug);
+	for (; nrpages-- > 0; blkno++) {
+
+		if (!f2fs_is_valid_blkaddr(sbi, blkno, type))
+			goto out;
+
+		switch (type) {
+		case META_NAT:
+			if (unlikely(blkno >=
+					NAT_BLOCK_OFFSET(NM_I(sbi)->max_nid)))
+				blkno = 0;
+			/* get nat block addr */
+			fio.new_blkaddr = current_nat_addr(sbi,
+					blkno * NAT_ENTRY_PER_BLOCK);
+			break;
+		case META_SIT:
+			/* get sit block addr */
+			fio.new_blkaddr = current_sit_addr(sbi,
+					blkno * SIT_ENTRY_PER_BLOCK);
+			break;
+		case META_SSA:
+		case META_CP:
+		case META_POR:
+			fio.new_blkaddr = blkno;
+			break;
+		default:
+			BUG();
+		}
+
+		page = f2fs_grab_cache_page(META_MAPPING(sbi),
+						fio.new_blkaddr, false);
+		if (!page)
+			continue;
+		if (PageUptodate(page)) {
+			f2fs_put_page(page, 1);
+			continue;
+		}
+
+		fio.page = page;
+		f2fs_submit_page_bio(&fio);
+		f2fs_put_page(page, 0);
+	}
+out:
+	blk_finish_plug(&plug);
+	return blkno - start;
+}
+
+void ra_meta_pages_cond(struct f2fs_sb_info *sbi, pgoff_t index)
+{
+	struct page *page;
+	bool readahead = false;
+
+	page = find_get_page(META_MAPPING(sbi), index);
+	if (!page || !PageUptodate(page))
+		readahead = true;
+	f2fs_put_page(page, 0);
+
+	if (readahead)
+		ra_meta_pages(sbi, index, BIO_MAX_PAGES, META_POR, true);
+}
+
+static int __f2fs_write_meta_page(struct page *page,
+				struct writeback_control *wbc,
+				enum iostat_type io_type)
+{
+	struct f2fs_sb_info *sbi = F2FS_P_SB(page);
+
+	trace_f2fs_writepage(page, META);
+
+	if (unlikely(f2fs_cp_error(sbi))) {
+		dec_page_count(sbi, F2FS_DIRTY_META);
+		unlock_page(page);
+		return 0;
+	}
+	if (unlikely(is_sbi_flag_set(sbi, SBI_POR_DOING)))
+		goto redirty_out;
+	if (wbc->for_reclaim && page->index < GET_SUM_BLOCK(sbi, 0))
+		goto redirty_out;
+
+	write_meta_page(sbi, page, io_type);
+	dec_page_count(sbi, F2FS_DIRTY_META);
+
+	if (wbc->for_reclaim)
+		f2fs_submit_merged_write_cond(sbi, page->mapping->host,
+						0, page->index, META);
+
+	unlock_page(page);
+
+	if (unlikely(f2fs_cp_error(sbi)))
+		f2fs_submit_merged_write(sbi, META);
+
+	return 0;
+
+redirty_out:
+	redirty_page_for_writepage(wbc, page);
+	return AOP_WRITEPAGE_ACTIVATE;
+}
+
+static int f2fs_write_meta_page(struct page *page,
+				struct writeback_control *wbc)
+{
+	return __f2fs_write_meta_page(page, wbc, FS_META_IO);
+}
+
+static int f2fs_write_meta_pages(struct address_space *mapping,
+				struct writeback_control *wbc)
+{
+	struct f2fs_sb_info *sbi = F2FS_M_SB(mapping);
+	long diff, written;
+
+	if (unlikely(is_sbi_flag_set(sbi, SBI_POR_DOING)))
+		goto skip_write;
+
+	/* collect a number of dirty meta pages and write together */
+	if (wbc->for_kupdate ||
+		get_pages(sbi, F2FS_DIRTY_META) < nr_pages_to_skip(sbi, META))
+		goto skip_write;
+
+	/* if locked failed, cp will flush dirty pages instead */
+	if (!mutex_trylock(&sbi->cp_mutex))
+		goto skip_write;
+
+	trace_f2fs_writepages(mapping->host, wbc, META);
+	diff = nr_pages_to_write(sbi, META, wbc);
+	written = sync_meta_pages(sbi, META, wbc->nr_to_write, FS_META_IO);
+	mutex_unlock(&sbi->cp_mutex);
+	wbc->nr_to_write = max((long)0, wbc->nr_to_write - written - diff);
+	return 0;
+
+skip_write:
+	wbc->pages_skipped += get_pages(sbi, F2FS_DIRTY_META);
+	trace_f2fs_writepages(mapping->host, wbc, META);
+	return 0;
+}
+
+long sync_meta_pages(struct f2fs_sb_info *sbi, enum page_type type,
+				long nr_to_write, enum iostat_type io_type)
+{
+	struct address_space *mapping = META_MAPPING(sbi);
+	pgoff_t index = 0, end = ULONG_MAX, prev = ULONG_MAX;
+	struct pagevec pvec;
+	long nwritten = 0;
+	struct writeback_control wbc = {
+		.for_reclaim = 0,
+	};
+	struct blk_plug plug;
+
+	pagevec_init(&pvec, 0);
+
+	blk_start_plug(&plug);
+
+	while (index <= end) {
+		int i, nr_pages;
+		nr_pages = pagevec_lookup_tag(&pvec, mapping, &index,
+				PAGECACHE_TAG_DIRTY,
+				min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1);
+		if (unlikely(nr_pages == 0))
+			break;
+
+		for (i = 0; i < nr_pages; i++) {
+			struct page *page = pvec.pages[i];
+
+			if (prev == ULONG_MAX)
+				prev = page->index - 1;
+			if (nr_to_write != LONG_MAX && page->index != prev + 1) {
+				pagevec_release(&pvec);
+				goto stop;
+			}
+
+			lock_page(page);
+
+			if (unlikely(page->mapping != mapping)) {
+continue_unlock:
+				unlock_page(page);
+				continue;
+			}
+			if (!PageDirty(page)) {
+				/* someone wrote it for us */
+				goto continue_unlock;
+			}
+
+			f2fs_wait_on_page_writeback(page, META, true);
+
+			BUG_ON(PageWriteback(page));
+			if (!clear_page_dirty_for_io(page))
+				goto continue_unlock;
+
+			if (__f2fs_write_meta_page(page, &wbc, io_type)) {
+				unlock_page(page);
+				break;
+			}
+			nwritten++;
+			prev = page->index;
+			if (unlikely(nwritten >= nr_to_write))
+				break;
+		}
+		pagevec_release(&pvec);
+		cond_resched();
+	}
+stop:
+	if (nwritten)
+		f2fs_submit_merged_write(sbi, type);
+
+	blk_finish_plug(&plug);
+
+	return nwritten;
+}
+
+static int f2fs_set_meta_page_dirty(struct page *page)
+{
+	trace_f2fs_set_page_dirty(page, META);
+
+	if (!PageUptodate(page))
+		SetPageUptodate(page);
+	if (!PageDirty(page)) {
+		__set_page_dirty_nobuffers(page);
+		inc_page_count(F2FS_P_SB(page), F2FS_DIRTY_META);
+		SetPagePrivate(page);
+		f2fs_trace_pid(page);
+		return 1;
+	}
+	return 0;
+}
+
+const struct address_space_operations f2fs_meta_aops = {
+	.writepage	= f2fs_write_meta_page,
+	.writepages	= f2fs_write_meta_pages,
+	.set_page_dirty	= f2fs_set_meta_page_dirty,
+	.invalidatepage = f2fs_invalidate_page,
+	.releasepage	= f2fs_release_page,
+#ifdef CONFIG_MIGRATION
+	.migratepage    = f2fs_migrate_page,
+#endif
+};
+
+static void __add_ino_entry(struct f2fs_sb_info *sbi, nid_t ino,
+						unsigned int devidx, int type)
+{
+	struct inode_management *im = &sbi->im[type];
+	struct ino_entry *e, *tmp;
+
+	tmp = f2fs_kmem_cache_alloc(ino_entry_slab, GFP_NOFS);
+
+	radix_tree_preload(GFP_NOFS | __GFP_NOFAIL);
+
+	spin_lock(&im->ino_lock);
+	e = radix_tree_lookup(&im->ino_root, ino);
+	if (!e) {
+		e = tmp;
+		if (unlikely(radix_tree_insert(&im->ino_root, ino, e)))
+			f2fs_bug_on(sbi, 1);
+
+		memset(e, 0, sizeof(struct ino_entry));
+		e->ino = ino;
+
+		list_add_tail(&e->list, &im->ino_list);
+		if (type != ORPHAN_INO)
+			im->ino_num++;
+	}
+
+	if (type == FLUSH_INO)
+		f2fs_set_bit(devidx, (char *)&e->dirty_device);
+
+	spin_unlock(&im->ino_lock);
+	radix_tree_preload_end();
+
+	if (e != tmp)
+		kmem_cache_free(ino_entry_slab, tmp);
+}
+
+static void __remove_ino_entry(struct f2fs_sb_info *sbi, nid_t ino, int type)
+{
+	struct inode_management *im = &sbi->im[type];
+	struct ino_entry *e;
+
+	spin_lock(&im->ino_lock);
+	e = radix_tree_lookup(&im->ino_root, ino);
+	if (e) {
+		list_del(&e->list);
+		radix_tree_delete(&im->ino_root, ino);
+		im->ino_num--;
+		spin_unlock(&im->ino_lock);
+		kmem_cache_free(ino_entry_slab, e);
+		return;
+	}
+	spin_unlock(&im->ino_lock);
+}
+
+void add_ino_entry(struct f2fs_sb_info *sbi, nid_t ino, int type)
+{
+	/* add new dirty ino entry into list */
+	__add_ino_entry(sbi, ino, 0, type);
+}
+
+void remove_ino_entry(struct f2fs_sb_info *sbi, nid_t ino, int type)
+{
+	/* remove dirty ino entry from list */
+	__remove_ino_entry(sbi, ino, type);
+}
+
+/* mode should be APPEND_INO or UPDATE_INO */
+bool exist_written_data(struct f2fs_sb_info *sbi, nid_t ino, int mode)
+{
+	struct inode_management *im = &sbi->im[mode];
+	struct ino_entry *e;
+
+	spin_lock(&im->ino_lock);
+	e = radix_tree_lookup(&im->ino_root, ino);
+	spin_unlock(&im->ino_lock);
+	return e ? true : false;
+}
+
+void release_ino_entry(struct f2fs_sb_info *sbi, bool all)
+{
+	struct ino_entry *e, *tmp;
+	int i;
+
+	for (i = all ? ORPHAN_INO : APPEND_INO; i < MAX_INO_ENTRY; i++) {
+		struct inode_management *im = &sbi->im[i];
+
+		spin_lock(&im->ino_lock);
+		list_for_each_entry_safe(e, tmp, &im->ino_list, list) {
+			list_del(&e->list);
+			radix_tree_delete(&im->ino_root, e->ino);
+			kmem_cache_free(ino_entry_slab, e);
+			im->ino_num--;
+		}
+		spin_unlock(&im->ino_lock);
+	}
+}
+
+void set_dirty_device(struct f2fs_sb_info *sbi, nid_t ino,
+					unsigned int devidx, int type)
+{
+	__add_ino_entry(sbi, ino, devidx, type);
+}
+
+bool is_dirty_device(struct f2fs_sb_info *sbi, nid_t ino,
+					unsigned int devidx, int type)
+{
+	struct inode_management *im = &sbi->im[type];
+	struct ino_entry *e;
+	bool is_dirty = false;
+
+	spin_lock(&im->ino_lock);
+	e = radix_tree_lookup(&im->ino_root, ino);
+	if (e && f2fs_test_bit(devidx, (char *)&e->dirty_device))
+		is_dirty = true;
+	spin_unlock(&im->ino_lock);
+	return is_dirty;
+}
+
+int acquire_orphan_inode(struct f2fs_sb_info *sbi)
+{
+	struct inode_management *im = &sbi->im[ORPHAN_INO];
+	int err = 0;
+
+	spin_lock(&im->ino_lock);
+
+#ifdef CONFIG_F2FS_FAULT_INJECTION
+	if (time_to_inject(sbi, FAULT_ORPHAN)) {
+		spin_unlock(&im->ino_lock);
+		f2fs_show_injection_info(FAULT_ORPHAN);
+		return -ENOSPC;
+	}
+#endif
+	if (unlikely(im->ino_num >= sbi->max_orphans))
+		err = -ENOSPC;
+	else
+		im->ino_num++;
+	spin_unlock(&im->ino_lock);
+
+	return err;
+}
+
+void release_orphan_inode(struct f2fs_sb_info *sbi)
+{
+	struct inode_management *im = &sbi->im[ORPHAN_INO];
+
+	spin_lock(&im->ino_lock);
+	f2fs_bug_on(sbi, im->ino_num == 0);
+	im->ino_num--;
+	spin_unlock(&im->ino_lock);
+}
+
+void add_orphan_inode(struct inode *inode)
+{
+	/* add new orphan ino entry into list */
+	__add_ino_entry(F2FS_I_SB(inode), inode->i_ino, 0, ORPHAN_INO);
+	update_inode_page(inode);
+}
+
+void remove_orphan_inode(struct f2fs_sb_info *sbi, nid_t ino)
+{
+	/* remove orphan entry from orphan list */
+	__remove_ino_entry(sbi, ino, ORPHAN_INO);
+}
+
+static int recover_orphan_inode(struct f2fs_sb_info *sbi, nid_t ino)
+{
+	struct inode *inode;
+	struct node_info ni;
+	int err = acquire_orphan_inode(sbi);
+
+	if (err)
+		goto err_out;
+
+	__add_ino_entry(sbi, ino, 0, ORPHAN_INO);
+
+	inode = f2fs_iget_retry(sbi->sb, ino);
+	if (IS_ERR(inode)) {
+		/*
+		 * there should be a bug that we can't find the entry
+		 * to orphan inode.
+		 */
+		f2fs_bug_on(sbi, PTR_ERR(inode) == -ENOENT);
+		return PTR_ERR(inode);
+	}
+
+	err = dquot_initialize(inode);
+	if (err)
+		goto err_out;
+
+	dquot_initialize(inode);
+	clear_nlink(inode);
+
+	/* truncate all the data during iput */
+	iput(inode);
+
+	get_node_info(sbi, ino, &ni);
+
+	/* ENOMEM was fully retried in f2fs_evict_inode. */
+	if (ni.blk_addr != NULL_ADDR) {
+		err = -EIO;
+		goto err_out;
+	}
+	__remove_ino_entry(sbi, ino, ORPHAN_INO);
+	return 0;
+
+err_out:
+	set_sbi_flag(sbi, SBI_NEED_FSCK);
+	f2fs_msg(sbi->sb, KERN_WARNING,
+			"%s: orphan failed (ino=%x), run fsck to fix.",
+			__func__, ino);
+	return err;
+}
+
+int recover_orphan_inodes(struct f2fs_sb_info *sbi)
+{
+	block_t start_blk, orphan_blocks, i, j;
+	unsigned int s_flags = sbi->sb->s_flags;
+	int err = 0;
+#ifdef CONFIG_QUOTA
+	int quota_enabled;
+#endif
+
+	if (!is_set_ckpt_flags(sbi, CP_ORPHAN_PRESENT_FLAG))
+		return 0;
+
+	if (s_flags & MS_RDONLY) {
+		f2fs_msg(sbi->sb, KERN_INFO, "orphan cleanup on readonly fs");
+		sbi->sb->s_flags &= ~MS_RDONLY;
+	}
+
+#ifdef CONFIG_QUOTA
+	/* Needed for iput() to work correctly and not trash data */
+	sbi->sb->s_flags |= MS_ACTIVE;
+
+	/* Turn on quotas so that they are updated correctly */
+	quota_enabled = f2fs_enable_quota_files(sbi, s_flags & MS_RDONLY);
+#endif
+
+	start_blk = __start_cp_addr(sbi) + 1 + __cp_payload(sbi);
+	orphan_blocks = __start_sum_addr(sbi) - 1 - __cp_payload(sbi);
+
+	ra_meta_pages(sbi, start_blk, orphan_blocks, META_CP, true);
+
+	for (i = 0; i < orphan_blocks; i++) {
+		struct page *page = get_meta_page(sbi, start_blk + i);
+		struct f2fs_orphan_block *orphan_blk;
+
+		orphan_blk = (struct f2fs_orphan_block *)page_address(page);
+		for (j = 0; j < le32_to_cpu(orphan_blk->entry_count); j++) {
+			nid_t ino = le32_to_cpu(orphan_blk->ino[j]);
+			err = recover_orphan_inode(sbi, ino);
+			if (err) {
+				f2fs_put_page(page, 1);
+				goto out;
+			}
+		}
+		f2fs_put_page(page, 1);
+	}
+	/* clear Orphan Flag */
+	clear_ckpt_flags(sbi, CP_ORPHAN_PRESENT_FLAG);
+out:
+#ifdef CONFIG_QUOTA
+	/* Turn quotas off */
+	if (quota_enabled)
+		f2fs_quota_off_umount(sbi->sb);
+#endif
+	sbi->sb->s_flags = s_flags; /* Restore MS_RDONLY status */
+
+	return err;
+}
+
+static void write_orphan_inodes(struct f2fs_sb_info *sbi, block_t start_blk)
+{
+	struct list_head *head;
+	struct f2fs_orphan_block *orphan_blk = NULL;
+	unsigned int nentries = 0;
+	unsigned short index = 1;
+	unsigned short orphan_blocks;
+	struct page *page = NULL;
+	struct ino_entry *orphan = NULL;
+	struct inode_management *im = &sbi->im[ORPHAN_INO];
+
+	orphan_blocks = GET_ORPHAN_BLOCKS(im->ino_num);
+
+	/*
+	 * we don't need to do spin_lock(&im->ino_lock) here, since all the
+	 * orphan inode operations are covered under f2fs_lock_op().
+	 * And, spin_lock should be avoided due to page operations below.
+	 */
+	head = &im->ino_list;
+
+	/* loop for each orphan inode entry and write them in Jornal block */
+	list_for_each_entry(orphan, head, list) {
+		if (!page) {
+			page = grab_meta_page(sbi, start_blk++);
+			orphan_blk =
+				(struct f2fs_orphan_block *)page_address(page);
+			memset(orphan_blk, 0, sizeof(*orphan_blk));
+		}
+
+		orphan_blk->ino[nentries++] = cpu_to_le32(orphan->ino);
+
+		if (nentries == F2FS_ORPHANS_PER_BLOCK) {
+			/*
+			 * an orphan block is full of 1020 entries,
+			 * then we need to flush current orphan blocks
+			 * and bring another one in memory
+			 */
+			orphan_blk->blk_addr = cpu_to_le16(index);
+			orphan_blk->blk_count = cpu_to_le16(orphan_blocks);
+			orphan_blk->entry_count = cpu_to_le32(nentries);
+			set_page_dirty(page);
+			f2fs_put_page(page, 1);
+			index++;
+			nentries = 0;
+			page = NULL;
+		}
+	}
+
+	if (page) {
+		orphan_blk->blk_addr = cpu_to_le16(index);
+		orphan_blk->blk_count = cpu_to_le16(orphan_blocks);
+		orphan_blk->entry_count = cpu_to_le32(nentries);
+		set_page_dirty(page);
+		f2fs_put_page(page, 1);
+	}
+}
+
+static int get_checkpoint_version(struct f2fs_sb_info *sbi, block_t cp_addr,
+		struct f2fs_checkpoint **cp_block, struct page **cp_page,
+		unsigned long long *version)
+{
+	unsigned long blk_size = sbi->blocksize;
+	size_t crc_offset = 0;
+	__u32 crc = 0;
+
+	*cp_page = get_meta_page(sbi, cp_addr);
+	*cp_block = (struct f2fs_checkpoint *)page_address(*cp_page);
+
+	crc_offset = le32_to_cpu((*cp_block)->checksum_offset);
+	if (crc_offset > (blk_size - sizeof(__le32))) {
+		f2fs_put_page(*cp_page, 1);
+		f2fs_msg(sbi->sb, KERN_WARNING,
+			"invalid crc_offset: %zu", crc_offset);
+		return -EINVAL;
+	}
+
+	crc = cur_cp_crc(*cp_block);
+	if (!f2fs_crc_valid(sbi, crc, *cp_block, crc_offset)) {
+		f2fs_put_page(*cp_page, 1);
+		f2fs_msg(sbi->sb, KERN_WARNING, "invalid crc value");
+		return -EINVAL;
+	}
+
+	*version = cur_cp_version(*cp_block);
+	return 0;
+}
+
+static struct page *validate_checkpoint(struct f2fs_sb_info *sbi,
+				block_t cp_addr, unsigned long long *version)
+{
+	struct page *cp_page_1 = NULL, *cp_page_2 = NULL;
+	struct f2fs_checkpoint *cp_block = NULL;
+	unsigned long long cur_version = 0, pre_version = 0;
+	int err;
+
+	err = get_checkpoint_version(sbi, cp_addr, &cp_block,
+					&cp_page_1, version);
+	if (err)
+		return NULL;
+
+	if (le32_to_cpu(cp_block->cp_pack_total_block_count) >
+					sbi->blocks_per_seg) {
+		f2fs_msg(sbi->sb, KERN_WARNING,
+			"invalid cp_pack_total_block_count:%u",
+			le32_to_cpu(cp_block->cp_pack_total_block_count));
+		goto invalid_cp;
+	}
+	pre_version = *version;
+
+	cp_addr += le32_to_cpu(cp_block->cp_pack_total_block_count) - 1;
+	err = get_checkpoint_version(sbi, cp_addr, &cp_block,
+					&cp_page_2, version);
+	if (err)
+		goto invalid_cp;
+	cur_version = *version;
+
+	if (cur_version == pre_version) {
+		*version = cur_version;
+		f2fs_put_page(cp_page_2, 1);
+		return cp_page_1;
+	}
+	f2fs_put_page(cp_page_2, 1);
+invalid_cp:
+	f2fs_put_page(cp_page_1, 1);
+	return NULL;
+}
+
+int get_valid_checkpoint(struct f2fs_sb_info *sbi)
+{
+	struct f2fs_checkpoint *cp_block;
+	struct f2fs_super_block *fsb = sbi->raw_super;
+	struct page *cp1, *cp2, *cur_page;
+	unsigned long blk_size = sbi->blocksize;
+	unsigned long long cp1_version = 0, cp2_version = 0;
+	unsigned long long cp_start_blk_no;
+	unsigned int cp_blks = 1 + __cp_payload(sbi);
+	block_t cp_blk_no;
+	int i;
+	int err;
+
+	sbi->ckpt = f2fs_kzalloc(sbi, cp_blks * blk_size, GFP_KERNEL);
+	if (!sbi->ckpt)
+		return -ENOMEM;
+	/*
+	 * Finding out valid cp block involves read both
+	 * sets( cp pack1 and cp pack 2)
+	 */
+	cp_start_blk_no = le32_to_cpu(fsb->cp_blkaddr);
+	cp1 = validate_checkpoint(sbi, cp_start_blk_no, &cp1_version);
+
+	/* The second checkpoint pack should start at the next segment */
+	cp_start_blk_no += ((unsigned long long)1) <<
+				le32_to_cpu(fsb->log_blocks_per_seg);
+	cp2 = validate_checkpoint(sbi, cp_start_blk_no, &cp2_version);
+
+	if (cp1 && cp2) {
+		if (ver_after(cp2_version, cp1_version))
+			cur_page = cp2;
+		else
+			cur_page = cp1;
+	} else if (cp1) {
+		cur_page = cp1;
+	} else if (cp2) {
+		cur_page = cp2;
+	} else {
+		err = -EFSCORRUPTED;
+		goto fail_no_cp;
+	}
+
+	cp_block = (struct f2fs_checkpoint *)page_address(cur_page);
+	memcpy(sbi->ckpt, cp_block, blk_size);
+
+	if (cur_page == cp1)
+		sbi->cur_cp_pack = 1;
+	else
+		sbi->cur_cp_pack = 2;
+
+	/* Sanity checking of checkpoint */
+	if (sanity_check_ckpt(sbi)) {
+		err = -EFSCORRUPTED;
+		goto free_fail_no_cp;
+	}
+
+	if (cp_blks <= 1)
+		goto done;
+
+	cp_blk_no = le32_to_cpu(fsb->cp_blkaddr);
+	if (cur_page == cp2)
+		cp_blk_no += 1 << le32_to_cpu(fsb->log_blocks_per_seg);
+
+	for (i = 1; i < cp_blks; i++) {
+		void *sit_bitmap_ptr;
+		unsigned char *ckpt = (unsigned char *)sbi->ckpt;
+
+		cur_page = get_meta_page(sbi, cp_blk_no + i);
+		sit_bitmap_ptr = page_address(cur_page);
+		memcpy(ckpt + i * blk_size, sit_bitmap_ptr, blk_size);
+		f2fs_put_page(cur_page, 1);
+	}
+done:
+	f2fs_put_page(cp1, 1);
+	f2fs_put_page(cp2, 1);
+	return 0;
+
+free_fail_no_cp:
+	f2fs_put_page(cp1, 1);
+	f2fs_put_page(cp2, 1);
+fail_no_cp:
+	kfree(sbi->ckpt);
+	return err;
+}
+
+static void __add_dirty_inode(struct inode *inode, enum inode_type type)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	int flag = (type == DIR_INODE) ? FI_DIRTY_DIR : FI_DIRTY_FILE;
+
+	if (is_inode_flag_set(inode, flag))
+		return;
+
+	set_inode_flag(inode, flag);
+	if (!f2fs_is_volatile_file(inode))
+		list_add_tail(&F2FS_I(inode)->dirty_list,
+						&sbi->inode_list[type]);
+	stat_inc_dirty_inode(sbi, type);
+}
+
+static void __remove_dirty_inode(struct inode *inode, enum inode_type type)
+{
+	int flag = (type == DIR_INODE) ? FI_DIRTY_DIR : FI_DIRTY_FILE;
+
+	if (get_dirty_pages(inode) || !is_inode_flag_set(inode, flag))
+		return;
+
+	list_del_init(&F2FS_I(inode)->dirty_list);
+	clear_inode_flag(inode, flag);
+	stat_dec_dirty_inode(F2FS_I_SB(inode), type);
+}
+
+void update_dirty_page(struct inode *inode, struct page *page)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	enum inode_type type = S_ISDIR(inode->i_mode) ? DIR_INODE : FILE_INODE;
+
+	if (!S_ISDIR(inode->i_mode) && !S_ISREG(inode->i_mode) &&
+			!S_ISLNK(inode->i_mode))
+		return;
+
+	spin_lock(&sbi->inode_lock[type]);
+	if (type != FILE_INODE || test_opt(sbi, DATA_FLUSH))
+		__add_dirty_inode(inode, type);
+	inode_inc_dirty_pages(inode);
+	spin_unlock(&sbi->inode_lock[type]);
+
+	SetPagePrivate(page);
+	f2fs_trace_pid(page);
+}
+
+void remove_dirty_inode(struct inode *inode)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	enum inode_type type = S_ISDIR(inode->i_mode) ? DIR_INODE : FILE_INODE;
+
+	if (!S_ISDIR(inode->i_mode) && !S_ISREG(inode->i_mode) &&
+			!S_ISLNK(inode->i_mode))
+		return;
+
+	if (type == FILE_INODE && !test_opt(sbi, DATA_FLUSH))
+		return;
+
+	spin_lock(&sbi->inode_lock[type]);
+	__remove_dirty_inode(inode, type);
+	spin_unlock(&sbi->inode_lock[type]);
+}
+
+int sync_dirty_inodes(struct f2fs_sb_info *sbi, enum inode_type type)
+{
+	struct list_head *head;
+	struct inode *inode;
+	struct f2fs_inode_info *fi;
+	bool is_dir = (type == DIR_INODE);
+	unsigned long ino = 0;
+
+	trace_f2fs_sync_dirty_inodes_enter(sbi->sb, is_dir,
+				get_pages(sbi, is_dir ?
+				F2FS_DIRTY_DENTS : F2FS_DIRTY_DATA));
+retry:
+	if (unlikely(f2fs_cp_error(sbi)))
+		return -EIO;
+
+	spin_lock(&sbi->inode_lock[type]);
+
+	head = &sbi->inode_list[type];
+	if (list_empty(head)) {
+		spin_unlock(&sbi->inode_lock[type]);
+		trace_f2fs_sync_dirty_inodes_exit(sbi->sb, is_dir,
+				get_pages(sbi, is_dir ?
+				F2FS_DIRTY_DENTS : F2FS_DIRTY_DATA));
+		return 0;
+	}
+	fi = list_first_entry(head, struct f2fs_inode_info, dirty_list);
+	inode = igrab(&fi->vfs_inode);
+	spin_unlock(&sbi->inode_lock[type]);
+	if (inode) {
+		unsigned long cur_ino = inode->i_ino;
+
+		if (is_dir)
+			F2FS_I(inode)->cp_task = current;
+
+		filemap_fdatawrite(inode->i_mapping);
+
+		if (is_dir)
+			F2FS_I(inode)->cp_task = NULL;
+
+		iput(inode);
+		/* We need to give cpu to another writers. */
+		if (ino == cur_ino) {
+			congestion_wait(BLK_RW_ASYNC, HZ/50);
+			cond_resched();
+		} else {
+			ino = cur_ino;
+		}
+	} else {
+		/*
+		 * We should submit bio, since it exists several
+		 * wribacking dentry pages in the freeing inode.
+		 */
+		f2fs_submit_merged_write(sbi, DATA);
+		cond_resched();
+	}
+	goto retry;
+}
+
+int f2fs_sync_inode_meta(struct f2fs_sb_info *sbi)
+{
+	struct list_head *head = &sbi->inode_list[DIRTY_META];
+	struct inode *inode;
+	struct f2fs_inode_info *fi;
+	s64 total = get_pages(sbi, F2FS_DIRTY_IMETA);
+
+	while (total--) {
+		if (unlikely(f2fs_cp_error(sbi)))
+			return -EIO;
+
+		spin_lock(&sbi->inode_lock[DIRTY_META]);
+		if (list_empty(head)) {
+			spin_unlock(&sbi->inode_lock[DIRTY_META]);
+			return 0;
+		}
+		fi = list_first_entry(head, struct f2fs_inode_info,
+							gdirty_list);
+		inode = igrab(&fi->vfs_inode);
+		spin_unlock(&sbi->inode_lock[DIRTY_META]);
+		if (inode) {
+			sync_inode_metadata(inode, 0);
+
+			/* it's on eviction */
+			if (is_inode_flag_set(inode, FI_DIRTY_INODE))
+				update_inode_page(inode);
+			iput(inode);
+		}
+	}
+	return 0;
+}
+
+static void __prepare_cp_block(struct f2fs_sb_info *sbi)
+{
+	struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	nid_t last_nid = nm_i->next_scan_nid;
+
+	next_free_nid(sbi, &last_nid);
+	ckpt->valid_block_count = cpu_to_le64(valid_user_blocks(sbi));
+	ckpt->valid_node_count = cpu_to_le32(valid_node_count(sbi));
+	ckpt->valid_inode_count = cpu_to_le32(valid_inode_count(sbi));
+	ckpt->next_free_nid = cpu_to_le32(last_nid);
+}
+
+/*
+ * Freeze all the FS-operations for checkpoint.
+ */
+static int block_operations(struct f2fs_sb_info *sbi)
+{
+	struct writeback_control wbc = {
+		.sync_mode = WB_SYNC_ALL,
+		.nr_to_write = LONG_MAX,
+		.for_reclaim = 0,
+	};
+	struct blk_plug plug;
+	int err = 0;
+
+	blk_start_plug(&plug);
+
+retry_flush_dents:
+	f2fs_lock_all(sbi);
+	/* write all the dirty dentry pages */
+	if (get_pages(sbi, F2FS_DIRTY_DENTS)) {
+		f2fs_unlock_all(sbi);
+		err = sync_dirty_inodes(sbi, DIR_INODE);
+		if (err)
+			goto out;
+		cond_resched();
+		goto retry_flush_dents;
+	}
+
+	/*
+	 * POR: we should ensure that there are no dirty node pages
+	 * until finishing nat/sit flush. inode->i_blocks can be updated.
+	 */
+	down_write(&sbi->node_change);
+
+	if (get_pages(sbi, F2FS_DIRTY_IMETA)) {
+		up_write(&sbi->node_change);
+		f2fs_unlock_all(sbi);
+		err = f2fs_sync_inode_meta(sbi);
+		if (err)
+			goto out;
+		cond_resched();
+		goto retry_flush_dents;
+	}
+
+retry_flush_nodes:
+	down_write(&sbi->node_write);
+
+	if (get_pages(sbi, F2FS_DIRTY_NODES)) {
+		up_write(&sbi->node_write);
+		err = sync_node_pages(sbi, &wbc, false, FS_CP_NODE_IO);
+		if (err) {
+			up_write(&sbi->node_change);
+			f2fs_unlock_all(sbi);
+			goto out;
+		}
+		cond_resched();
+		goto retry_flush_nodes;
+	}
+
+	/*
+	 * sbi->node_change is used only for AIO write_begin path which produces
+	 * dirty node blocks and some checkpoint values by block allocation.
+	 */
+	__prepare_cp_block(sbi);
+	up_write(&sbi->node_change);
+out:
+	blk_finish_plug(&plug);
+	return err;
+}
+
+static void unblock_operations(struct f2fs_sb_info *sbi)
+{
+	up_write(&sbi->node_write);
+	f2fs_unlock_all(sbi);
+}
+
+static void wait_on_all_pages_writeback(struct f2fs_sb_info *sbi)
+{
+	DEFINE_WAIT(wait);
+
+	for (;;) {
+		prepare_to_wait(&sbi->cp_wait, &wait, TASK_UNINTERRUPTIBLE);
+
+		if (!get_pages(sbi, F2FS_WB_CP_DATA))
+			break;
+
+		io_schedule_timeout(5*HZ);
+	}
+	finish_wait(&sbi->cp_wait, &wait);
+}
+
+static void update_ckpt_flags(struct f2fs_sb_info *sbi, struct cp_control *cpc)
+{
+	unsigned long orphan_num = sbi->im[ORPHAN_INO].ino_num;
+	struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
+	unsigned long flags;
+
+	spin_lock_irqsave(&sbi->cp_lock, flags);
+
+	if ((cpc->reason & CP_UMOUNT) &&
+			le32_to_cpu(ckpt->cp_pack_total_block_count) >
+			sbi->blocks_per_seg - NM_I(sbi)->nat_bits_blocks)
+		disable_nat_bits(sbi, false);
+
+	if (cpc->reason & CP_TRIMMED)
+		__set_ckpt_flags(ckpt, CP_TRIMMED_FLAG);
+	else
+		__clear_ckpt_flags(ckpt, CP_TRIMMED_FLAG);
+
+	if (cpc->reason & CP_UMOUNT)
+		__set_ckpt_flags(ckpt, CP_UMOUNT_FLAG);
+	else
+		__clear_ckpt_flags(ckpt, CP_UMOUNT_FLAG);
+
+	if (cpc->reason & CP_FASTBOOT)
+		__set_ckpt_flags(ckpt, CP_FASTBOOT_FLAG);
+	else
+		__clear_ckpt_flags(ckpt, CP_FASTBOOT_FLAG);
+
+	if (orphan_num)
+		__set_ckpt_flags(ckpt, CP_ORPHAN_PRESENT_FLAG);
+	else
+		__clear_ckpt_flags(ckpt, CP_ORPHAN_PRESENT_FLAG);
+
+	if (is_sbi_flag_set(sbi, SBI_NEED_FSCK))
+		__set_ckpt_flags(ckpt, CP_FSCK_FLAG);
+
+	/* set this flag to activate crc|cp_ver for recovery */
+	__set_ckpt_flags(ckpt, CP_CRC_RECOVERY_FLAG);
+	__clear_ckpt_flags(ckpt, CP_NOCRC_RECOVERY_FLAG);
+
+	spin_unlock_irqrestore(&sbi->cp_lock, flags);
+}
+
+static void commit_checkpoint(struct f2fs_sb_info *sbi,
+	void *src, block_t blk_addr)
+{
+	struct writeback_control wbc = {
+		.for_reclaim = 0,
+	};
+
+	/*
+	 * pagevec_lookup_tag and lock_page again will take
+	 * some extra time. Therefore, update_meta_pages and
+	 * sync_meta_pages are combined in this function.
+	 */
+	struct page *page = grab_meta_page(sbi, blk_addr);
+	int err;
+
+	memcpy(page_address(page), src, PAGE_SIZE);
+	set_page_dirty(page);
+
+	f2fs_wait_on_page_writeback(page, META, true);
+	f2fs_bug_on(sbi, PageWriteback(page));
+	if (unlikely(!clear_page_dirty_for_io(page)))
+		f2fs_bug_on(sbi, 1);
+
+	/* writeout cp pack 2 page */
+	err = __f2fs_write_meta_page(page, &wbc, FS_CP_META_IO);
+	f2fs_bug_on(sbi, err);
+
+	f2fs_put_page(page, 0);
+
+	/* submit checkpoint (with barrier if NOBARRIER is not set) */
+	f2fs_submit_merged_write(sbi, META_FLUSH);
+}
+
+static int do_checkpoint(struct f2fs_sb_info *sbi, struct cp_control *cpc)
+{
+	struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	unsigned long orphan_num = sbi->im[ORPHAN_INO].ino_num, flags;
+	block_t start_blk;
+	unsigned int data_sum_blocks, orphan_blocks;
+	__u32 crc32 = 0;
+	int i;
+	int cp_payload_blks = __cp_payload(sbi);
+	struct super_block *sb = sbi->sb;
+	struct curseg_info *seg_i = CURSEG_I(sbi, CURSEG_HOT_NODE);
+	u64 kbytes_written;
+	int err;
+
+	/* Flush all the NAT/SIT pages */
+	while (get_pages(sbi, F2FS_DIRTY_META)) {
+		sync_meta_pages(sbi, META, LONG_MAX, FS_CP_META_IO);
+		if (unlikely(f2fs_cp_error(sbi)))
+			return -EIO;
+	}
+
+	/*
+	 * modify checkpoint
+	 * version number is already updated
+	 */
+	ckpt->elapsed_time = cpu_to_le64(get_mtime(sbi));
+	ckpt->free_segment_count = cpu_to_le32(free_segments(sbi));
+	for (i = 0; i < NR_CURSEG_NODE_TYPE; i++) {
+		ckpt->cur_node_segno[i] =
+			cpu_to_le32(curseg_segno(sbi, i + CURSEG_HOT_NODE));
+		ckpt->cur_node_blkoff[i] =
+			cpu_to_le16(curseg_blkoff(sbi, i + CURSEG_HOT_NODE));
+		ckpt->alloc_type[i + CURSEG_HOT_NODE] =
+				curseg_alloc_type(sbi, i + CURSEG_HOT_NODE);
+	}
+	for (i = 0; i < NR_CURSEG_DATA_TYPE; i++) {
+		ckpt->cur_data_segno[i] =
+			cpu_to_le32(curseg_segno(sbi, i + CURSEG_HOT_DATA));
+		ckpt->cur_data_blkoff[i] =
+			cpu_to_le16(curseg_blkoff(sbi, i + CURSEG_HOT_DATA));
+		ckpt->alloc_type[i + CURSEG_HOT_DATA] =
+				curseg_alloc_type(sbi, i + CURSEG_HOT_DATA);
+	}
+
+	/* 2 cp  + n data seg summary + orphan inode blocks */
+	data_sum_blocks = npages_for_summary_flush(sbi, false);
+	spin_lock_irqsave(&sbi->cp_lock, flags);
+	if (data_sum_blocks < NR_CURSEG_DATA_TYPE)
+		__set_ckpt_flags(ckpt, CP_COMPACT_SUM_FLAG);
+	else
+		__clear_ckpt_flags(ckpt, CP_COMPACT_SUM_FLAG);
+	spin_unlock_irqrestore(&sbi->cp_lock, flags);
+
+	orphan_blocks = GET_ORPHAN_BLOCKS(orphan_num);
+	ckpt->cp_pack_start_sum = cpu_to_le32(1 + cp_payload_blks +
+			orphan_blocks);
+
+	if (__remain_node_summaries(cpc->reason))
+		ckpt->cp_pack_total_block_count = cpu_to_le32(F2FS_CP_PACKS+
+				cp_payload_blks + data_sum_blocks +
+				orphan_blocks + NR_CURSEG_NODE_TYPE);
+	else
+		ckpt->cp_pack_total_block_count = cpu_to_le32(F2FS_CP_PACKS +
+				cp_payload_blks + data_sum_blocks +
+				orphan_blocks);
+
+	/* update ckpt flag for checkpoint */
+	update_ckpt_flags(sbi, cpc);
+
+	/* update SIT/NAT bitmap */
+	get_sit_bitmap(sbi, __bitmap_ptr(sbi, SIT_BITMAP));
+	get_nat_bitmap(sbi, __bitmap_ptr(sbi, NAT_BITMAP));
+
+	crc32 = f2fs_crc32(sbi, ckpt, le32_to_cpu(ckpt->checksum_offset));
+	*((__le32 *)((unsigned char *)ckpt +
+				le32_to_cpu(ckpt->checksum_offset)))
+				= cpu_to_le32(crc32);
+
+	start_blk = __start_cp_next_addr(sbi);
+
+	/* write nat bits */
+	if (enabled_nat_bits(sbi, cpc)) {
+		__u64 cp_ver = cur_cp_version(ckpt);
+		block_t blk;
+
+		cp_ver |= ((__u64)crc32 << 32);
+		*(__le64 *)nm_i->nat_bits = cpu_to_le64(cp_ver);
+
+		blk = start_blk + sbi->blocks_per_seg - nm_i->nat_bits_blocks;
+		for (i = 0; i < nm_i->nat_bits_blocks; i++)
+			update_meta_page(sbi, nm_i->nat_bits +
+					(i << F2FS_BLKSIZE_BITS), blk + i);
+
+		/* Flush all the NAT BITS pages */
+		while (get_pages(sbi, F2FS_DIRTY_META)) {
+			sync_meta_pages(sbi, META, LONG_MAX, FS_CP_META_IO);
+			if (unlikely(f2fs_cp_error(sbi)))
+				return -EIO;
+		}
+	}
+
+	/* write out checkpoint buffer at block 0 */
+	update_meta_page(sbi, ckpt, start_blk++);
+
+	for (i = 1; i < 1 + cp_payload_blks; i++)
+		update_meta_page(sbi, (char *)ckpt + i * F2FS_BLKSIZE,
+							start_blk++);
+
+	if (orphan_num) {
+		write_orphan_inodes(sbi, start_blk);
+		start_blk += orphan_blocks;
+	}
+
+	write_data_summaries(sbi, start_blk);
+	start_blk += data_sum_blocks;
+
+	/* Record write statistics in the hot node summary */
+	kbytes_written = sbi->kbytes_written;
+	if (sb->s_bdev->bd_part)
+		kbytes_written += BD_PART_WRITTEN(sbi);
+
+	seg_i->journal->info.kbytes_written = cpu_to_le64(kbytes_written);
+
+	if (__remain_node_summaries(cpc->reason)) {
+		write_node_summaries(sbi, start_blk);
+		start_blk += NR_CURSEG_NODE_TYPE;
+	}
+
+	/* update user_block_counts */
+	sbi->last_valid_block_count = sbi->total_valid_block_count;
+	percpu_counter_set(&sbi->alloc_valid_block_count, 0);
+
+	/* Here, we have one bio having CP pack except cp pack 2 page */
+	sync_meta_pages(sbi, META, LONG_MAX, FS_CP_META_IO);
+
+	/* wait for previous submitted meta pages writeback */
+	wait_on_all_pages_writeback(sbi);
+
+	if (unlikely(f2fs_cp_error(sbi)))
+		return -EIO;
+
+	/* flush all device cache */
+	err = f2fs_flush_device_cache(sbi);
+	if (err)
+		return err;
+
+	/* barrier and flush checkpoint cp pack 2 page if it can */
+	commit_checkpoint(sbi, ckpt, start_blk);
+	wait_on_all_pages_writeback(sbi);
+
+	release_ino_entry(sbi, false);
+
+	if (unlikely(f2fs_cp_error(sbi)))
+		return -EIO;
+
+	clear_sbi_flag(sbi, SBI_IS_DIRTY);
+	clear_sbi_flag(sbi, SBI_NEED_CP);
+	__set_cp_next_pack(sbi);
+
+	/*
+	 * redirty superblock if metadata like node page or inode cache is
+	 * updated during writing checkpoint.
+	 */
+	if (get_pages(sbi, F2FS_DIRTY_NODES) ||
+			get_pages(sbi, F2FS_DIRTY_IMETA))
+		set_sbi_flag(sbi, SBI_IS_DIRTY);
+
+	f2fs_bug_on(sbi, get_pages(sbi, F2FS_DIRTY_DENTS));
+
+	return 0;
+}
+
+/*
+ * We guarantee that this checkpoint procedure will not fail.
+ */
+int write_checkpoint(struct f2fs_sb_info *sbi, struct cp_control *cpc)
+{
+	struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
+	unsigned long long ckpt_ver;
+	int err = 0;
+
+	mutex_lock(&sbi->cp_mutex);
+
+	if (!is_sbi_flag_set(sbi, SBI_IS_DIRTY) &&
+		((cpc->reason & CP_FASTBOOT) || (cpc->reason & CP_SYNC) ||
+		((cpc->reason & CP_DISCARD) && !sbi->discard_blks)))
+		goto out;
+	if (unlikely(f2fs_cp_error(sbi))) {
+		err = -EIO;
+		goto out;
+	}
+	if (f2fs_readonly(sbi->sb)) {
+		err = -EROFS;
+		goto out;
+	}
+
+	trace_f2fs_write_checkpoint(sbi->sb, cpc->reason, "start block_ops");
+
+	err = block_operations(sbi);
+	if (err)
+		goto out;
+
+	trace_f2fs_write_checkpoint(sbi->sb, cpc->reason, "finish block_ops");
+
+	f2fs_flush_merged_writes(sbi);
+
+	/* this is the case of multiple fstrims without any changes */
+	if (cpc->reason & CP_DISCARD) {
+		if (!exist_trim_candidates(sbi, cpc)) {
+			unblock_operations(sbi);
+			goto out;
+		}
+
+		if (NM_I(sbi)->dirty_nat_cnt == 0 &&
+				SIT_I(sbi)->dirty_sentries == 0 &&
+				prefree_segments(sbi) == 0) {
+			flush_sit_entries(sbi, cpc);
+			clear_prefree_segments(sbi, cpc);
+			unblock_operations(sbi);
+			goto out;
+		}
+	}
+
+	/*
+	 * update checkpoint pack index
+	 * Increase the version number so that
+	 * SIT entries and seg summaries are written at correct place
+	 */
+	ckpt_ver = cur_cp_version(ckpt);
+	ckpt->checkpoint_ver = cpu_to_le64(++ckpt_ver);
+
+	/* write cached NAT/SIT entries to NAT/SIT area */
+	flush_nat_entries(sbi, cpc);
+	flush_sit_entries(sbi, cpc);
+
+	/* unlock all the fs_lock[] in do_checkpoint() */
+	err = do_checkpoint(sbi, cpc);
+	if (err)
+		release_discard_addrs(sbi);
+	else
+		clear_prefree_segments(sbi, cpc);
+
+	unblock_operations(sbi);
+	stat_inc_cp_count(sbi->stat_info);
+
+	if (cpc->reason & CP_RECOVERY)
+		f2fs_msg(sbi->sb, KERN_NOTICE,
+			"checkpoint: version = %llx", ckpt_ver);
+
+	/* do checkpoint periodically */
+	f2fs_update_time(sbi, CP_TIME);
+	trace_f2fs_write_checkpoint(sbi->sb, cpc->reason, "finish checkpoint");
+out:
+	mutex_unlock(&sbi->cp_mutex);
+	return err;
+}
+
+void init_ino_entry_info(struct f2fs_sb_info *sbi)
+{
+	int i;
+
+	for (i = 0; i < MAX_INO_ENTRY; i++) {
+		struct inode_management *im = &sbi->im[i];
+
+		INIT_RADIX_TREE(&im->ino_root, GFP_ATOMIC);
+		spin_lock_init(&im->ino_lock);
+		INIT_LIST_HEAD(&im->ino_list);
+		im->ino_num = 0;
+	}
+
+	sbi->max_orphans = (sbi->blocks_per_seg - F2FS_CP_PACKS -
+			NR_CURSEG_TYPE - __cp_payload(sbi)) *
+				F2FS_ORPHANS_PER_BLOCK;
+}
+
+int __init create_checkpoint_caches(void)
+{
+	ino_entry_slab = f2fs_kmem_cache_create("f2fs_ino_entry",
+			sizeof(struct ino_entry));
+	if (!ino_entry_slab)
+		return -ENOMEM;
+	inode_entry_slab = f2fs_kmem_cache_create("f2fs_inode_entry",
+			sizeof(struct inode_entry));
+	if (!inode_entry_slab) {
+		kmem_cache_destroy(ino_entry_slab);
+		return -ENOMEM;
+	}
+	return 0;
+}
+
+void destroy_checkpoint_caches(void)
+{
+	kmem_cache_destroy(ino_entry_slab);
+	kmem_cache_destroy(inode_entry_slab);
+}
diff --git a/src/kernel/linux/v4.14/fs/f2fs/data.c b/src/kernel/linux/v4.14/fs/f2fs/data.c
new file mode 100644
index 0000000..4048602
--- /dev/null
+++ b/src/kernel/linux/v4.14/fs/f2fs/data.c
@@ -0,0 +1,2700 @@
+/*
+ * fs/f2fs/data.c
+ *
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ *             http://www.samsung.com/
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/fs.h>
+#include <linux/f2fs_fs.h>
+#include <linux/buffer_head.h>
+#include <linux/mpage.h>
+#include <linux/writeback.h>
+#include <linux/backing-dev.h>
+#include <linux/pagevec.h>
+#include <linux/blkdev.h>
+#include <linux/bio.h>
+#include <linux/prefetch.h>
+#include <linux/uio.h>
+#include <linux/cleancache.h>
+#include <linux/sched/signal.h>
+
+#include "f2fs.h"
+#include "node.h"
+#include "segment.h"
+#include "trace.h"
+#include <trace/events/f2fs.h>
+#include <trace/events/android_fs.h>
+
+#define NUM_PREALLOC_POST_READ_CTXS	128
+
+static struct kmem_cache *bio_post_read_ctx_cache;
+static mempool_t *bio_post_read_ctx_pool;
+
+static bool __is_cp_guaranteed(struct page *page)
+{
+	struct address_space *mapping = page->mapping;
+	struct inode *inode;
+	struct f2fs_sb_info *sbi;
+
+	if (!mapping)
+		return false;
+
+	inode = mapping->host;
+	sbi = F2FS_I_SB(inode);
+
+	if (inode->i_ino == F2FS_META_INO(sbi) ||
+			inode->i_ino ==  F2FS_NODE_INO(sbi) ||
+			S_ISDIR(inode->i_mode) ||
+			is_cold_data(page))
+		return true;
+	return false;
+}
+
+/* postprocessing steps for read bios */
+enum bio_post_read_step {
+	STEP_INITIAL = 0,
+	STEP_DECRYPT,
+};
+
+struct bio_post_read_ctx {
+	struct bio *bio;
+	struct work_struct work;
+	unsigned int cur_step;
+	unsigned int enabled_steps;
+};
+
+static void __read_end_io(struct bio *bio)
+{
+	struct page *page;
+	struct bio_vec *bv;
+	int i;
+
+	bio_for_each_segment_all(bv, bio, i) {
+		page = bv->bv_page;
+
+		/* PG_error was set if any post_read step failed */
+		if (bio->bi_status || PageError(page)) {
+			ClearPageUptodate(page);
+			SetPageError(page);
+		} else {
+			SetPageUptodate(page);
+		}
+		unlock_page(page);
+	}
+	if (bio->bi_private)
+		mempool_free(bio->bi_private, bio_post_read_ctx_pool);
+	bio_put(bio);
+}
+
+static void bio_post_read_processing(struct bio_post_read_ctx *ctx);
+
+static void decrypt_work(struct work_struct *work)
+{
+	struct bio_post_read_ctx *ctx =
+		container_of(work, struct bio_post_read_ctx, work);
+
+	fscrypt_decrypt_bio(ctx->bio);
+
+	bio_post_read_processing(ctx);
+}
+
+static void bio_post_read_processing(struct bio_post_read_ctx *ctx)
+{
+	switch (++ctx->cur_step) {
+	case STEP_DECRYPT:
+		if (ctx->enabled_steps & (1 << STEP_DECRYPT)) {
+			INIT_WORK(&ctx->work, decrypt_work);
+			fscrypt_enqueue_decrypt_work(&ctx->work);
+			return;
+		}
+		ctx->cur_step++;
+		/* fall-through */
+	default:
+		__read_end_io(ctx->bio);
+	}
+}
+
+static bool f2fs_bio_post_read_required(struct bio *bio)
+{
+	return bio->bi_private && !bio->bi_status;
+}
+
+static void f2fs_read_end_io(struct bio *bio)
+{
+#ifdef CONFIG_F2FS_FAULT_INJECTION
+	if (time_to_inject(F2FS_P_SB(bio->bi_io_vec->bv_page), FAULT_IO)) {
+		f2fs_show_injection_info(FAULT_IO);
+		bio->bi_status = BLK_STS_IOERR;
+	}
+#endif
+
+	if (f2fs_bio_post_read_required(bio)) {
+		struct bio_post_read_ctx *ctx = bio->bi_private;
+
+		ctx->cur_step = STEP_INITIAL;
+		bio_post_read_processing(ctx);
+		return;
+	}
+
+	__read_end_io(bio);
+}
+
+static void f2fs_write_end_io(struct bio *bio)
+{
+	struct f2fs_sb_info *sbi = bio->bi_private;
+	struct bio_vec *bvec;
+	int i;
+
+	bio_for_each_segment_all(bvec, bio, i) {
+		struct page *page = bvec->bv_page;
+		enum count_type type = WB_DATA_TYPE(page);
+
+		if (IS_DUMMY_WRITTEN_PAGE(page)) {
+			set_page_private(page, (unsigned long)NULL);
+			ClearPagePrivate(page);
+			unlock_page(page);
+			mempool_free(page, sbi->write_io_dummy);
+
+			if (unlikely(bio->bi_status))
+				f2fs_stop_checkpoint(sbi, true);
+			continue;
+		}
+
+		fscrypt_pullback_bio_page(&page, true);
+
+		if (unlikely(bio->bi_status)) {
+			mapping_set_error(page->mapping, -EIO);
+			if (type == F2FS_WB_CP_DATA)
+				f2fs_stop_checkpoint(sbi, true);
+		}
+
+		f2fs_bug_on(sbi, page->mapping == NODE_MAPPING(sbi) &&
+					page->index != nid_of_node(page));
+
+		dec_page_count(sbi, type);
+		clear_cold_data(page);
+		end_page_writeback(page);
+	}
+	if (!get_pages(sbi, F2FS_WB_CP_DATA) &&
+				wq_has_sleeper(&sbi->cp_wait))
+		wake_up(&sbi->cp_wait);
+
+	bio_put(bio);
+}
+
+/*
+ * Return true, if pre_bio's bdev is same as its target device.
+ */
+struct block_device *f2fs_target_device(struct f2fs_sb_info *sbi,
+				block_t blk_addr, struct bio *bio)
+{
+	struct block_device *bdev = sbi->sb->s_bdev;
+	int i;
+
+	if (f2fs_is_multi_device(sbi)) {
+		for (i = 0; i < sbi->s_ndevs; i++) {
+			if (FDEV(i).start_blk <= blk_addr &&
+			    FDEV(i).end_blk >= blk_addr) {
+				blk_addr -= FDEV(i).start_blk;
+				bdev = FDEV(i).bdev;
+				break;
+			}
+		}
+	}
+	if (bio) {
+		bio_set_dev(bio, bdev);
+		bio->bi_iter.bi_sector = SECTOR_FROM_BLOCK(blk_addr);
+	}
+	return bdev;
+}
+
+int f2fs_target_device_index(struct f2fs_sb_info *sbi, block_t blkaddr)
+{
+	int i;
+
+	if (!f2fs_is_multi_device(sbi))
+		return 0;
+
+	for (i = 0; i < sbi->s_ndevs; i++)
+		if (FDEV(i).start_blk <= blkaddr && FDEV(i).end_blk >= blkaddr)
+			return i;
+	return 0;
+}
+
+static bool __same_bdev(struct f2fs_sb_info *sbi,
+				block_t blk_addr, struct bio *bio)
+{
+	struct block_device *b = f2fs_target_device(sbi, blk_addr, NULL);
+	return bio->bi_disk == b->bd_disk && bio->bi_partno == b->bd_partno;
+}
+
+/*
+ * Low-level block read/write IO operations.
+ */
+static struct bio *__bio_alloc(struct f2fs_sb_info *sbi, block_t blk_addr,
+				struct writeback_control *wbc,
+				int npages, bool is_read,
+				enum page_type type, enum temp_type temp)
+{
+	struct bio *bio;
+
+	bio = f2fs_bio_alloc(sbi, npages, true);
+
+	f2fs_target_device(sbi, blk_addr, bio);
+	if (is_read) {
+		bio->bi_end_io = f2fs_read_end_io;
+		bio->bi_private = NULL;
+	} else {
+		bio->bi_end_io = f2fs_write_end_io;
+		bio->bi_private = sbi;
+		bio->bi_write_hint = io_type_to_rw_hint(sbi, type, temp);
+	}
+	if (wbc)
+		wbc_init_bio(wbc, bio);
+
+	return bio;
+}
+
+static inline void __submit_bio(struct f2fs_sb_info *sbi,
+				struct bio *bio, enum page_type type)
+{
+	if (!is_read_io(bio_op(bio))) {
+		unsigned int start;
+
+		if (type != DATA && type != NODE)
+			goto submit_io;
+
+		if (f2fs_sb_has_blkzoned(sbi->sb) && current->plug)
+			blk_finish_plug(current->plug);
+
+		start = bio->bi_iter.bi_size >> F2FS_BLKSIZE_BITS;
+		start %= F2FS_IO_SIZE(sbi);
+
+		if (start == 0)
+			goto submit_io;
+
+		/* fill dummy pages */
+		for (; start < F2FS_IO_SIZE(sbi); start++) {
+			struct page *page =
+				mempool_alloc(sbi->write_io_dummy,
+					GFP_NOIO | __GFP_ZERO | __GFP_NOFAIL);
+			f2fs_bug_on(sbi, !page);
+
+			SetPagePrivate(page);
+			set_page_private(page, (unsigned long)DUMMY_WRITTEN_PAGE);
+			lock_page(page);
+			if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE)
+				f2fs_bug_on(sbi, 1);
+		}
+		/*
+		 * In the NODE case, we lose next block address chain. So, we
+		 * need to do checkpoint in f2fs_sync_file.
+		 */
+		if (type == NODE)
+			set_sbi_flag(sbi, SBI_NEED_CP);
+	}
+submit_io:
+	if (is_read_io(bio_op(bio)))
+		trace_f2fs_submit_read_bio(sbi->sb, type, bio);
+	else
+		trace_f2fs_submit_write_bio(sbi->sb, type, bio);
+	submit_bio(bio);
+}
+
+static void __submit_merged_bio(struct f2fs_bio_info *io)
+{
+	struct f2fs_io_info *fio = &io->fio;
+
+	if (!io->bio)
+		return;
+
+	bio_set_op_attrs(io->bio, fio->op, fio->op_flags);
+
+	if (is_read_io(fio->op))
+		trace_f2fs_prepare_read_bio(io->sbi->sb, fio->type, io->bio);
+	else
+		trace_f2fs_prepare_write_bio(io->sbi->sb, fio->type, io->bio);
+
+	__submit_bio(io->sbi, io->bio, fio->type);
+	io->bio = NULL;
+}
+
+static bool __has_merged_page(struct f2fs_bio_info *io,
+				struct inode *inode, nid_t ino, pgoff_t idx)
+{
+	struct bio_vec *bvec;
+	struct page *target;
+	int i;
+
+	if (!io->bio)
+		return false;
+
+	if (!inode && !ino)
+		return true;
+
+	bio_for_each_segment_all(bvec, io->bio, i) {
+
+		if (bvec->bv_page->mapping)
+			target = bvec->bv_page;
+		else
+			target = fscrypt_control_page(bvec->bv_page);
+
+		if (idx != target->index)
+			continue;
+
+		if (inode && inode == target->mapping->host)
+			return true;
+		if (ino && ino == ino_of_node(target))
+			return true;
+	}
+
+	return false;
+}
+
+static bool has_merged_page(struct f2fs_sb_info *sbi, struct inode *inode,
+				nid_t ino, pgoff_t idx, enum page_type type)
+{
+	enum page_type btype = PAGE_TYPE_OF_BIO(type);
+	enum temp_type temp;
+	struct f2fs_bio_info *io;
+	bool ret = false;
+
+	for (temp = HOT; temp < NR_TEMP_TYPE; temp++) {
+		io = sbi->write_io[btype] + temp;
+
+		down_read(&io->io_rwsem);
+		ret = __has_merged_page(io, inode, ino, idx);
+		up_read(&io->io_rwsem);
+
+		/* TODO: use HOT temp only for meta pages now. */
+		if (ret || btype == META)
+			break;
+	}
+	return ret;
+}
+
+static void __f2fs_submit_merged_write(struct f2fs_sb_info *sbi,
+				enum page_type type, enum temp_type temp)
+{
+	enum page_type btype = PAGE_TYPE_OF_BIO(type);
+	struct f2fs_bio_info *io = sbi->write_io[btype] + temp;
+
+	down_write(&io->io_rwsem);
+
+	/* change META to META_FLUSH in the checkpoint procedure */
+	if (type >= META_FLUSH) {
+		io->fio.type = META_FLUSH;
+		io->fio.op = REQ_OP_WRITE;
+		io->fio.op_flags = REQ_META | REQ_PRIO | REQ_SYNC;
+		if (!test_opt(sbi, NOBARRIER))
+			io->fio.op_flags |= REQ_PREFLUSH | REQ_FUA;
+	}
+	__submit_merged_bio(io);
+	up_write(&io->io_rwsem);
+}
+
+static void __submit_merged_write_cond(struct f2fs_sb_info *sbi,
+				struct inode *inode, nid_t ino, pgoff_t idx,
+				enum page_type type, bool force)
+{
+	enum temp_type temp;
+
+	if (!force && !has_merged_page(sbi, inode, ino, idx, type))
+		return;
+
+	for (temp = HOT; temp < NR_TEMP_TYPE; temp++) {
+
+		__f2fs_submit_merged_write(sbi, type, temp);
+
+		/* TODO: use HOT temp only for meta pages now. */
+		if (type >= META)
+			break;
+	}
+}
+
+void f2fs_submit_merged_write(struct f2fs_sb_info *sbi, enum page_type type)
+{
+	__submit_merged_write_cond(sbi, NULL, 0, 0, type, true);
+}
+
+void f2fs_submit_merged_write_cond(struct f2fs_sb_info *sbi,
+				struct inode *inode, nid_t ino, pgoff_t idx,
+				enum page_type type)
+{
+	__submit_merged_write_cond(sbi, inode, ino, idx, type, false);
+}
+
+void f2fs_flush_merged_writes(struct f2fs_sb_info *sbi)
+{
+	f2fs_submit_merged_write(sbi, DATA);
+	f2fs_submit_merged_write(sbi, NODE);
+	f2fs_submit_merged_write(sbi, META);
+}
+
+/*
+ * Fill the locked page with data located in the block address.
+ * A caller needs to unlock the page on failure.
+ */
+int f2fs_submit_page_bio(struct f2fs_io_info *fio)
+{
+	struct bio *bio;
+	struct page *page = fio->encrypted_page ?
+			fio->encrypted_page : fio->page;
+
+	if (!f2fs_is_valid_blkaddr(fio->sbi, fio->new_blkaddr,
+			__is_meta_io(fio) ? META_GENERIC : DATA_GENERIC))
+		return -EFSCORRUPTED;
+
+	trace_f2fs_submit_page_bio(page, fio);
+	f2fs_trace_ios(fio, 0);
+
+	/* Allocate a new bio */
+	bio = __bio_alloc(fio->sbi, fio->new_blkaddr, fio->io_wbc,
+				1, is_read_io(fio->op), fio->type, fio->temp);
+
+	if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) {
+		bio_put(bio);
+		return -EFAULT;
+	}
+	bio_set_op_attrs(bio, fio->op, fio->op_flags);
+
+	if (!is_read_io(fio->op))
+		inc_page_count(fio->sbi, WB_DATA_TYPE(fio->page));
+
+	__submit_bio(fio->sbi, bio, fio->type);
+	return 0;
+}
+
+int f2fs_submit_page_write(struct f2fs_io_info *fio)
+{
+	struct f2fs_sb_info *sbi = fio->sbi;
+	enum page_type btype = PAGE_TYPE_OF_BIO(fio->type);
+	struct f2fs_bio_info *io = sbi->write_io[btype] + fio->temp;
+	struct page *bio_page;
+	int err = 0;
+
+	f2fs_bug_on(sbi, is_read_io(fio->op));
+
+	down_write(&io->io_rwsem);
+next:
+	if (fio->in_list) {
+		spin_lock(&io->io_lock);
+		if (list_empty(&io->io_list)) {
+			spin_unlock(&io->io_lock);
+			goto out_fail;
+		}
+		fio = list_first_entry(&io->io_list,
+						struct f2fs_io_info, list);
+		list_del(&fio->list);
+		spin_unlock(&io->io_lock);
+	}
+
+	if (__is_valid_data_blkaddr(fio->old_blkaddr))
+		verify_block_addr(fio, fio->old_blkaddr);
+	verify_block_addr(fio, fio->new_blkaddr);
+
+	bio_page = fio->encrypted_page ? fio->encrypted_page : fio->page;
+
+	/* set submitted = true as a return value */
+	fio->submitted = true;
+
+	inc_page_count(sbi, WB_DATA_TYPE(bio_page));
+
+	if (io->bio && (io->last_block_in_bio != fio->new_blkaddr - 1 ||
+	    (io->fio.op != fio->op || io->fio.op_flags != fio->op_flags) ||
+			!__same_bdev(sbi, fio->new_blkaddr, io->bio)))
+		__submit_merged_bio(io);
+alloc_new:
+	if (io->bio == NULL) {
+		if ((fio->type == DATA || fio->type == NODE) &&
+				fio->new_blkaddr & F2FS_IO_SIZE_MASK(sbi)) {
+			err = -EAGAIN;
+			dec_page_count(sbi, WB_DATA_TYPE(bio_page));
+			goto out_fail;
+		}
+		io->bio = __bio_alloc(sbi, fio->new_blkaddr, fio->io_wbc,
+						BIO_MAX_PAGES, false,
+						fio->type, fio->temp);
+		io->fio = *fio;
+	}
+
+	if (bio_add_page(io->bio, bio_page, PAGE_SIZE, 0) < PAGE_SIZE) {
+		__submit_merged_bio(io);
+		goto alloc_new;
+	}
+
+	if (fio->io_wbc)
+		wbc_account_io(fio->io_wbc, bio_page, PAGE_SIZE);
+
+	io->last_block_in_bio = fio->new_blkaddr;
+	f2fs_trace_ios(fio, 0);
+
+	trace_f2fs_submit_page_write(fio->page, fio);
+
+	if (fio->in_list)
+		goto next;
+out_fail:
+	up_write(&io->io_rwsem);
+	return err;
+}
+
+static struct bio *f2fs_grab_read_bio(struct inode *inode, block_t blkaddr,
+							 unsigned nr_pages)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct bio *bio;
+	struct bio_post_read_ctx *ctx;
+	unsigned int post_read_steps = 0;
+
+	if (!f2fs_is_valid_blkaddr(sbi, blkaddr, DATA_GENERIC))
+		return ERR_PTR(-EFAULT);
+
+	bio = f2fs_bio_alloc(sbi, min_t(int, nr_pages, BIO_MAX_PAGES), false);
+	if (!bio)
+		return ERR_PTR(-ENOMEM);
+	f2fs_target_device(sbi, blkaddr, bio);
+	bio->bi_end_io = f2fs_read_end_io;
+	bio_set_op_attrs(bio, REQ_OP_READ, 0);
+
+	if (f2fs_encrypted_file(inode))
+		post_read_steps |= 1 << STEP_DECRYPT;
+	if (post_read_steps) {
+		ctx = mempool_alloc(bio_post_read_ctx_pool, GFP_NOFS);
+		if (!ctx) {
+			bio_put(bio);
+			return ERR_PTR(-ENOMEM);
+		}
+		ctx->bio = bio;
+		ctx->enabled_steps = post_read_steps;
+		bio->bi_private = ctx;
+
+		/* wait the page to be moved by cleaning */
+		f2fs_wait_on_block_writeback(sbi, blkaddr);
+	}
+
+	return bio;
+}
+
+/* This can handle encryption stuffs */
+static int f2fs_submit_page_read(struct inode *inode, struct page *page,
+							block_t blkaddr)
+{
+	struct bio *bio = f2fs_grab_read_bio(inode, blkaddr, 1);
+
+	if (IS_ERR(bio))
+		return PTR_ERR(bio);
+
+	if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) {
+		bio_put(bio);
+		return -EFAULT;
+	}
+	__submit_bio(F2FS_I_SB(inode), bio, DATA);
+	return 0;
+}
+
+static void __set_data_blkaddr(struct dnode_of_data *dn)
+{
+	struct f2fs_node *rn = F2FS_NODE(dn->node_page);
+	__le32 *addr_array;
+	int base = 0;
+
+	if (IS_INODE(dn->node_page) && f2fs_has_extra_attr(dn->inode))
+		base = get_extra_isize(dn->inode);
+
+	/* Get physical address of data block */
+	addr_array = blkaddr_in_node(rn);
+	addr_array[base + dn->ofs_in_node] = cpu_to_le32(dn->data_blkaddr);
+}
+
+/*
+ * Lock ordering for the change of data block address:
+ * ->data_page
+ *  ->node_page
+ *    update block addresses in the node page
+ */
+void set_data_blkaddr(struct dnode_of_data *dn)
+{
+	f2fs_wait_on_page_writeback(dn->node_page, NODE, true);
+	__set_data_blkaddr(dn);
+	if (set_page_dirty(dn->node_page))
+		dn->node_changed = true;
+}
+
+void f2fs_update_data_blkaddr(struct dnode_of_data *dn, block_t blkaddr)
+{
+	dn->data_blkaddr = blkaddr;
+	set_data_blkaddr(dn);
+	f2fs_update_extent_cache(dn);
+}
+
+/* dn->ofs_in_node will be returned with up-to-date last block pointer */
+int reserve_new_blocks(struct dnode_of_data *dn, blkcnt_t count)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(dn->inode);
+	int err;
+
+	if (!count)
+		return 0;
+
+	if (unlikely(is_inode_flag_set(dn->inode, FI_NO_ALLOC)))
+		return -EPERM;
+	if (unlikely((err = inc_valid_block_count(sbi, dn->inode, &count))))
+		return err;
+
+	trace_f2fs_reserve_new_blocks(dn->inode, dn->nid,
+						dn->ofs_in_node, count);
+
+	f2fs_wait_on_page_writeback(dn->node_page, NODE, true);
+
+	for (; count > 0; dn->ofs_in_node++) {
+		block_t blkaddr = datablock_addr(dn->inode,
+					dn->node_page, dn->ofs_in_node);
+		if (blkaddr == NULL_ADDR) {
+			dn->data_blkaddr = NEW_ADDR;
+			__set_data_blkaddr(dn);
+			count--;
+		}
+	}
+
+	if (set_page_dirty(dn->node_page))
+		dn->node_changed = true;
+	return 0;
+}
+
+/* Should keep dn->ofs_in_node unchanged */
+int reserve_new_block(struct dnode_of_data *dn)
+{
+	unsigned int ofs_in_node = dn->ofs_in_node;
+	int ret;
+
+	ret = reserve_new_blocks(dn, 1);
+	dn->ofs_in_node = ofs_in_node;
+	return ret;
+}
+
+int f2fs_reserve_block(struct dnode_of_data *dn, pgoff_t index)
+{
+	bool need_put = dn->inode_page ? false : true;
+	int err;
+
+	err = get_dnode_of_data(dn, index, ALLOC_NODE);
+	if (err)
+		return err;
+
+	if (dn->data_blkaddr == NULL_ADDR)
+		err = reserve_new_block(dn);
+	if (err || need_put)
+		f2fs_put_dnode(dn);
+	return err;
+}
+
+int f2fs_get_block(struct dnode_of_data *dn, pgoff_t index)
+{
+	struct extent_info ei  = {0,0,0};
+	struct inode *inode = dn->inode;
+
+	if (f2fs_lookup_extent_cache(inode, index, &ei)) {
+		dn->data_blkaddr = ei.blk + index - ei.fofs;
+		return 0;
+	}
+
+	return f2fs_reserve_block(dn, index);
+}
+
+struct page *get_read_data_page(struct inode *inode, pgoff_t index,
+						int op_flags, bool for_write)
+{
+	struct address_space *mapping = inode->i_mapping;
+	struct dnode_of_data dn;
+	struct page *page;
+	struct extent_info ei = {0,0,0};
+	int err;
+
+	page = f2fs_grab_cache_page(mapping, index, for_write);
+	if (!page)
+		return ERR_PTR(-ENOMEM);
+
+	if (f2fs_lookup_extent_cache(inode, index, &ei)) {
+		dn.data_blkaddr = ei.blk + index - ei.fofs;
+		goto got_it;
+	}
+
+	set_new_dnode(&dn, inode, NULL, NULL, 0);
+	err = get_dnode_of_data(&dn, index, LOOKUP_NODE);
+	if (err)
+		goto put_err;
+	f2fs_put_dnode(&dn);
+
+	if (unlikely(dn.data_blkaddr == NULL_ADDR)) {
+		err = -ENOENT;
+		goto put_err;
+	}
+got_it:
+	if (PageUptodate(page)) {
+		unlock_page(page);
+		return page;
+	}
+
+	/*
+	 * A new dentry page is allocated but not able to be written, since its
+	 * new inode page couldn't be allocated due to -ENOSPC.
+	 * In such the case, its blkaddr can be remained as NEW_ADDR.
+	 * see, f2fs_add_link -> get_new_data_page -> init_inode_metadata.
+	 */
+	if (dn.data_blkaddr == NEW_ADDR) {
+		zero_user_segment(page, 0, PAGE_SIZE);
+		if (!PageUptodate(page))
+			SetPageUptodate(page);
+		unlock_page(page);
+		return page;
+	}
+
+	err = f2fs_submit_page_read(inode, page, dn.data_blkaddr);
+	if (err)
+		goto put_err;
+	return page;
+
+put_err:
+	f2fs_put_page(page, 1);
+	return ERR_PTR(err);
+}
+
+struct page *find_data_page(struct inode *inode, pgoff_t index)
+{
+	struct address_space *mapping = inode->i_mapping;
+	struct page *page;
+
+	page = find_get_page(mapping, index);
+	if (page && PageUptodate(page))
+		return page;
+	f2fs_put_page(page, 0);
+
+	page = get_read_data_page(inode, index, 0, false);
+	if (IS_ERR(page))
+		return page;
+
+	if (PageUptodate(page))
+		return page;
+
+	wait_on_page_locked(page);
+	if (unlikely(!PageUptodate(page))) {
+		f2fs_put_page(page, 0);
+		return ERR_PTR(-EIO);
+	}
+	return page;
+}
+
+/*
+ * If it tries to access a hole, return an error.
+ * Because, the callers, functions in dir.c and GC, should be able to know
+ * whether this page exists or not.
+ */
+struct page *get_lock_data_page(struct inode *inode, pgoff_t index,
+							bool for_write)
+{
+	struct address_space *mapping = inode->i_mapping;
+	struct page *page;
+repeat:
+	page = get_read_data_page(inode, index, 0, for_write);
+	if (IS_ERR(page))
+		return page;
+
+	/* wait for read completion */
+	lock_page(page);
+	if (unlikely(page->mapping != mapping)) {
+		f2fs_put_page(page, 1);
+		goto repeat;
+	}
+	if (unlikely(!PageUptodate(page))) {
+		f2fs_put_page(page, 1);
+		return ERR_PTR(-EIO);
+	}
+	return page;
+}
+
+/*
+ * Caller ensures that this data page is never allocated.
+ * A new zero-filled data page is allocated in the page cache.
+ *
+ * Also, caller should grab and release a rwsem by calling f2fs_lock_op() and
+ * f2fs_unlock_op().
+ * Note that, ipage is set only by make_empty_dir, and if any error occur,
+ * ipage should be released by this function.
+ */
+struct page *get_new_data_page(struct inode *inode,
+		struct page *ipage, pgoff_t index, bool new_i_size)
+{
+	struct address_space *mapping = inode->i_mapping;
+	struct page *page;
+	struct dnode_of_data dn;
+	int err;
+
+	page = f2fs_grab_cache_page(mapping, index, true);
+	if (!page) {
+		/*
+		 * before exiting, we should make sure ipage will be released
+		 * if any error occur.
+		 */
+		f2fs_put_page(ipage, 1);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	set_new_dnode(&dn, inode, ipage, NULL, 0);
+	err = f2fs_reserve_block(&dn, index);
+	if (err) {
+		f2fs_put_page(page, 1);
+		return ERR_PTR(err);
+	}
+	if (!ipage)
+		f2fs_put_dnode(&dn);
+
+	if (PageUptodate(page))
+		goto got_it;
+
+	if (dn.data_blkaddr == NEW_ADDR) {
+		zero_user_segment(page, 0, PAGE_SIZE);
+		if (!PageUptodate(page))
+			SetPageUptodate(page);
+	} else {
+		f2fs_put_page(page, 1);
+
+		/* if ipage exists, blkaddr should be NEW_ADDR */
+		f2fs_bug_on(F2FS_I_SB(inode), ipage);
+		page = get_lock_data_page(inode, index, true);
+		if (IS_ERR(page))
+			return page;
+	}
+got_it:
+	if (new_i_size && i_size_read(inode) <
+				((loff_t)(index + 1) << PAGE_SHIFT))
+		f2fs_i_size_write(inode, ((loff_t)(index + 1) << PAGE_SHIFT));
+	return page;
+}
+
+static int __allocate_data_block(struct dnode_of_data *dn, int seg_type)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(dn->inode);
+	struct f2fs_summary sum;
+	struct node_info ni;
+	pgoff_t fofs;
+	blkcnt_t count = 1;
+	int err;
+
+	if (unlikely(is_inode_flag_set(dn->inode, FI_NO_ALLOC)))
+		return -EPERM;
+
+	dn->data_blkaddr = datablock_addr(dn->inode,
+				dn->node_page, dn->ofs_in_node);
+	if (dn->data_blkaddr == NEW_ADDR)
+		goto alloc;
+
+	if (unlikely((err = inc_valid_block_count(sbi, dn->inode, &count))))
+		return err;
+
+alloc:
+	get_node_info(sbi, dn->nid, &ni);
+	set_summary(&sum, dn->nid, dn->ofs_in_node, ni.version);
+
+	allocate_data_block(sbi, NULL, dn->data_blkaddr, &dn->data_blkaddr,
+					&sum, seg_type, NULL, false);
+	set_data_blkaddr(dn);
+
+	/* update i_size */
+	fofs = start_bidx_of_node(ofs_of_node(dn->node_page), dn->inode) +
+							dn->ofs_in_node;
+	if (i_size_read(dn->inode) < ((loff_t)(fofs + 1) << PAGE_SHIFT))
+		f2fs_i_size_write(dn->inode,
+				((loff_t)(fofs + 1) << PAGE_SHIFT));
+	return 0;
+}
+
+int f2fs_preallocate_blocks(struct kiocb *iocb, struct iov_iter *from)
+{
+	struct inode *inode = file_inode(iocb->ki_filp);
+	struct f2fs_map_blocks map;
+	int flag;
+	int err = 0;
+	bool direct_io = iocb->ki_flags & IOCB_DIRECT;
+
+	/* convert inline data for Direct I/O*/
+	if (direct_io) {
+		err = f2fs_convert_inline_inode(inode);
+		if (err)
+			return err;
+	}
+
+	if (is_inode_flag_set(inode, FI_NO_PREALLOC))
+		return 0;
+
+	map.m_lblk = F2FS_BLK_ALIGN(iocb->ki_pos);
+	map.m_len = F2FS_BYTES_TO_BLK(iocb->ki_pos + iov_iter_count(from));
+	if (map.m_len > map.m_lblk)
+		map.m_len -= map.m_lblk;
+	else
+		map.m_len = 0;
+
+	map.m_next_pgofs = NULL;
+	map.m_next_extent = NULL;
+	map.m_seg_type = NO_CHECK_TYPE;
+
+	if (direct_io) {
+		map.m_seg_type = rw_hint_to_seg_type(iocb->ki_hint);
+		flag = f2fs_force_buffered_io(inode, WRITE) ?
+					F2FS_GET_BLOCK_PRE_AIO :
+					F2FS_GET_BLOCK_PRE_DIO;
+		goto map_blocks;
+	}
+	if (iocb->ki_pos + iov_iter_count(from) > MAX_INLINE_DATA(inode)) {
+		err = f2fs_convert_inline_inode(inode);
+		if (err)
+			return err;
+	}
+	if (f2fs_has_inline_data(inode))
+		return err;
+
+	flag = F2FS_GET_BLOCK_PRE_AIO;
+
+map_blocks:
+	err = f2fs_map_blocks(inode, &map, 1, flag);
+	if (map.m_len > 0 && err == -ENOSPC) {
+		if (!direct_io)
+			set_inode_flag(inode, FI_NO_PREALLOC);
+		err = 0;
+	}
+	return err;
+}
+
+static inline void __do_map_lock(struct f2fs_sb_info *sbi, int flag, bool lock)
+{
+	if (flag == F2FS_GET_BLOCK_PRE_AIO) {
+		if (lock)
+			down_read(&sbi->node_change);
+		else
+			up_read(&sbi->node_change);
+	} else {
+		if (lock)
+			f2fs_lock_op(sbi);
+		else
+			f2fs_unlock_op(sbi);
+	}
+}
+
+/*
+ * f2fs_map_blocks() now supported readahead/bmap/rw direct_IO with
+ * f2fs_map_blocks structure.
+ * If original data blocks are allocated, then give them to blockdev.
+ * Otherwise,
+ *     a. preallocate requested block addresses
+ *     b. do not use extent cache for better performance
+ *     c. give the block addresses to blockdev
+ */
+int f2fs_map_blocks(struct inode *inode, struct f2fs_map_blocks *map,
+						int create, int flag)
+{
+	unsigned int maxblocks = map->m_len;
+	struct dnode_of_data dn;
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	int mode = create ? ALLOC_NODE : LOOKUP_NODE;
+	pgoff_t pgofs, end_offset, end;
+	int err = 0, ofs = 1;
+	unsigned int ofs_in_node, last_ofs_in_node;
+	blkcnt_t prealloc;
+	struct extent_info ei = {0,0,0};
+	block_t blkaddr;
+	unsigned int start_pgofs;
+
+	if (!maxblocks)
+		return 0;
+
+	map->m_len = 0;
+	map->m_flags = 0;
+
+	/* it only supports block size == page size */
+	pgofs =	(pgoff_t)map->m_lblk;
+	end = pgofs + maxblocks;
+
+	if (!create && f2fs_lookup_extent_cache(inode, pgofs, &ei)) {
+		map->m_pblk = ei.blk + pgofs - ei.fofs;
+		map->m_len = min((pgoff_t)maxblocks, ei.fofs + ei.len - pgofs);
+		map->m_flags = F2FS_MAP_MAPPED;
+		if (map->m_next_extent)
+			*map->m_next_extent = pgofs + map->m_len;
+		goto out;
+	}
+
+next_dnode:
+	if (create)
+		__do_map_lock(sbi, flag, true);
+
+	/* When reading holes, we need its node page */
+	set_new_dnode(&dn, inode, NULL, NULL, 0);
+	err = get_dnode_of_data(&dn, pgofs, mode);
+	if (err) {
+		if (flag == F2FS_GET_BLOCK_BMAP)
+			map->m_pblk = 0;
+		if (err == -ENOENT) {
+			err = 0;
+			if (map->m_next_pgofs)
+				*map->m_next_pgofs =
+					get_next_page_offset(&dn, pgofs);
+			if (map->m_next_extent)
+				*map->m_next_extent =
+					get_next_page_offset(&dn, pgofs);
+		}
+		goto unlock_out;
+	}
+
+	start_pgofs = pgofs;
+	prealloc = 0;
+	last_ofs_in_node = ofs_in_node = dn.ofs_in_node;
+	end_offset = ADDRS_PER_PAGE(dn.node_page, inode);
+
+next_block:
+	blkaddr = datablock_addr(dn.inode, dn.node_page, dn.ofs_in_node);
+
+	if (__is_valid_data_blkaddr(blkaddr) &&
+		!f2fs_is_valid_blkaddr(sbi, blkaddr, DATA_GENERIC)) {
+		err = -EFSCORRUPTED;
+		goto sync_out;
+	}
+
+	if (!is_valid_data_blkaddr(sbi, blkaddr)) {
+		if (create) {
+			if (unlikely(f2fs_cp_error(sbi))) {
+				err = -EIO;
+				goto sync_out;
+			}
+			if (flag == F2FS_GET_BLOCK_PRE_AIO) {
+				if (blkaddr == NULL_ADDR) {
+					prealloc++;
+					last_ofs_in_node = dn.ofs_in_node;
+				}
+			} else {
+				err = __allocate_data_block(&dn,
+							map->m_seg_type);
+				if (!err)
+					set_inode_flag(inode, FI_APPEND_WRITE);
+			}
+			if (err)
+				goto sync_out;
+			map->m_flags |= F2FS_MAP_NEW;
+			blkaddr = dn.data_blkaddr;
+		} else {
+			if (flag == F2FS_GET_BLOCK_BMAP) {
+				map->m_pblk = 0;
+				goto sync_out;
+			}
+			if (flag == F2FS_GET_BLOCK_PRECACHE)
+				goto sync_out;
+			if (flag == F2FS_GET_BLOCK_FIEMAP &&
+						blkaddr == NULL_ADDR) {
+				if (map->m_next_pgofs)
+					*map->m_next_pgofs = pgofs + 1;
+				goto sync_out;
+			}
+			if (flag != F2FS_GET_BLOCK_FIEMAP) {
+				/* for defragment case */
+				if (map->m_next_pgofs)
+					*map->m_next_pgofs = pgofs + 1;
+				goto sync_out;
+			}
+		}
+	}
+
+	if (flag == F2FS_GET_BLOCK_PRE_AIO)
+		goto skip;
+
+	if (map->m_len == 0) {
+		/* preallocated unwritten block should be mapped for fiemap. */
+		if (blkaddr == NEW_ADDR)
+			map->m_flags |= F2FS_MAP_UNWRITTEN;
+		map->m_flags |= F2FS_MAP_MAPPED;
+
+		map->m_pblk = blkaddr;
+		map->m_len = 1;
+	} else if ((map->m_pblk != NEW_ADDR &&
+			blkaddr == (map->m_pblk + ofs)) ||
+			(map->m_pblk == NEW_ADDR && blkaddr == NEW_ADDR) ||
+			flag == F2FS_GET_BLOCK_PRE_DIO) {
+		ofs++;
+		map->m_len++;
+	} else {
+		goto sync_out;
+	}
+
+skip:
+	dn.ofs_in_node++;
+	pgofs++;
+
+	/* preallocate blocks in batch for one dnode page */
+	if (flag == F2FS_GET_BLOCK_PRE_AIO &&
+			(pgofs == end || dn.ofs_in_node == end_offset)) {
+
+		dn.ofs_in_node = ofs_in_node;
+		err = reserve_new_blocks(&dn, prealloc);
+		if (err)
+			goto sync_out;
+
+		map->m_len += dn.ofs_in_node - ofs_in_node;
+		if (prealloc && dn.ofs_in_node != last_ofs_in_node + 1) {
+			err = -ENOSPC;
+			goto sync_out;
+		}
+		dn.ofs_in_node = end_offset;
+	}
+
+	if (pgofs >= end)
+		goto sync_out;
+	else if (dn.ofs_in_node < end_offset)
+		goto next_block;
+
+	if (flag == F2FS_GET_BLOCK_PRECACHE) {
+		if (map->m_flags & F2FS_MAP_MAPPED) {
+			unsigned int ofs = start_pgofs - map->m_lblk;
+
+			f2fs_update_extent_cache_range(&dn,
+				start_pgofs, map->m_pblk + ofs,
+				map->m_len - ofs);
+		}
+	}
+
+	f2fs_put_dnode(&dn);
+
+	if (create) {
+		__do_map_lock(sbi, flag, false);
+		f2fs_balance_fs(sbi, dn.node_changed);
+	}
+	goto next_dnode;
+
+sync_out:
+	if (flag == F2FS_GET_BLOCK_PRECACHE) {
+		if (map->m_flags & F2FS_MAP_MAPPED) {
+			unsigned int ofs = start_pgofs - map->m_lblk;
+
+			f2fs_update_extent_cache_range(&dn,
+				start_pgofs, map->m_pblk + ofs,
+				map->m_len - ofs);
+		}
+		if (map->m_next_extent)
+			*map->m_next_extent = pgofs + 1;
+	}
+	f2fs_put_dnode(&dn);
+unlock_out:
+	if (create) {
+		__do_map_lock(sbi, flag, false);
+		f2fs_balance_fs(sbi, dn.node_changed);
+	}
+out:
+	trace_f2fs_map_blocks(inode, map, err);
+	return err;
+}
+
+bool f2fs_overwrite_io(struct inode *inode, loff_t pos, size_t len)
+{
+	struct f2fs_map_blocks map;
+	block_t last_lblk;
+	int err;
+
+	if (pos + len > i_size_read(inode))
+		return false;
+
+	map.m_lblk = F2FS_BYTES_TO_BLK(pos);
+	map.m_next_pgofs = NULL;
+	map.m_next_extent = NULL;
+	map.m_seg_type = NO_CHECK_TYPE;
+	last_lblk = F2FS_BLK_ALIGN(pos + len);
+
+	while (map.m_lblk < last_lblk) {
+		map.m_len = last_lblk - map.m_lblk;
+		err = f2fs_map_blocks(inode, &map, 0, F2FS_GET_BLOCK_DEFAULT);
+		if (err || map.m_len == 0)
+			return false;
+		map.m_lblk += map.m_len;
+	}
+	return true;
+}
+
+static int __get_data_block(struct inode *inode, sector_t iblock,
+			struct buffer_head *bh, int create, int flag,
+			pgoff_t *next_pgofs, int seg_type)
+{
+	struct f2fs_map_blocks map;
+	int err;
+
+	map.m_lblk = iblock;
+	map.m_len = bh->b_size >> inode->i_blkbits;
+	map.m_next_pgofs = next_pgofs;
+	map.m_next_extent = NULL;
+	map.m_seg_type = seg_type;
+
+	err = f2fs_map_blocks(inode, &map, create, flag);
+	if (!err) {
+		map_bh(bh, inode->i_sb, map.m_pblk);
+		bh->b_state = (bh->b_state & ~F2FS_MAP_FLAGS) | map.m_flags;
+		bh->b_size = (u64)map.m_len << inode->i_blkbits;
+	}
+	return err;
+}
+
+static int get_data_block(struct inode *inode, sector_t iblock,
+			struct buffer_head *bh_result, int create, int flag,
+			pgoff_t *next_pgofs)
+{
+	return __get_data_block(inode, iblock, bh_result, create,
+							flag, next_pgofs,
+							NO_CHECK_TYPE);
+}
+
+static int get_data_block_dio(struct inode *inode, sector_t iblock,
+			struct buffer_head *bh_result, int create)
+{
+	return __get_data_block(inode, iblock, bh_result, create,
+						F2FS_GET_BLOCK_DEFAULT, NULL,
+						rw_hint_to_seg_type(
+							inode->i_write_hint));
+}
+
+static int get_data_block_bmap(struct inode *inode, sector_t iblock,
+			struct buffer_head *bh_result, int create)
+{
+	/* Block number less than F2FS MAX BLOCKS */
+	if (unlikely(iblock >= F2FS_I_SB(inode)->max_file_blocks))
+		return -EFBIG;
+
+	return __get_data_block(inode, iblock, bh_result, create,
+						F2FS_GET_BLOCK_BMAP, NULL,
+						NO_CHECK_TYPE);
+}
+
+static inline sector_t logical_to_blk(struct inode *inode, loff_t offset)
+{
+	return (offset >> inode->i_blkbits);
+}
+
+static inline loff_t blk_to_logical(struct inode *inode, sector_t blk)
+{
+	return (blk << inode->i_blkbits);
+}
+
+static int f2fs_xattr_fiemap(struct inode *inode,
+				struct fiemap_extent_info *fieinfo)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct page *page;
+	struct node_info ni;
+	__u64 phys = 0, len;
+	__u32 flags;
+	nid_t xnid = F2FS_I(inode)->i_xattr_nid;
+	int err = 0;
+
+	if (f2fs_has_inline_xattr(inode)) {
+		int offset;
+
+		page = f2fs_grab_cache_page(NODE_MAPPING(sbi),
+						inode->i_ino, false);
+		if (!page)
+			return -ENOMEM;
+
+		get_node_info(sbi, inode->i_ino, &ni);
+
+		phys = (__u64)blk_to_logical(inode, ni.blk_addr);
+		offset = offsetof(struct f2fs_inode, i_addr) +
+					sizeof(__le32) * (DEF_ADDRS_PER_INODE -
+					get_inline_xattr_addrs(inode));
+
+		phys += offset;
+		len = inline_xattr_size(inode);
+
+		f2fs_put_page(page, 1);
+
+		flags = FIEMAP_EXTENT_DATA_INLINE | FIEMAP_EXTENT_NOT_ALIGNED;
+
+		if (!xnid)
+			flags |= FIEMAP_EXTENT_LAST;
+
+		err = fiemap_fill_next_extent(fieinfo, 0, phys, len, flags);
+		if (err || err == 1)
+			return err;
+	}
+
+	if (xnid) {
+		page = f2fs_grab_cache_page(NODE_MAPPING(sbi), xnid, false);
+		if (!page)
+			return -ENOMEM;
+
+		get_node_info(sbi, xnid, &ni);
+
+		phys = (__u64)blk_to_logical(inode, ni.blk_addr);
+		len = inode->i_sb->s_blocksize;
+
+		f2fs_put_page(page, 1);
+
+		flags = FIEMAP_EXTENT_LAST;
+	}
+
+	if (phys)
+		err = fiemap_fill_next_extent(fieinfo, 0, phys, len, flags);
+
+	return (err < 0 ? err : 0);
+}
+
+int f2fs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
+		u64 start, u64 len)
+{
+	struct buffer_head map_bh;
+	sector_t start_blk, last_blk;
+	pgoff_t next_pgofs;
+	u64 logical = 0, phys = 0, size = 0;
+	u32 flags = 0;
+	int ret = 0;
+
+	if (fieinfo->fi_flags & FIEMAP_FLAG_CACHE) {
+		ret = f2fs_precache_extents(inode);
+		if (ret)
+			return ret;
+	}
+
+	ret = fiemap_check_flags(fieinfo, FIEMAP_FLAG_SYNC | FIEMAP_FLAG_XATTR);
+	if (ret)
+		return ret;
+
+	inode_lock(inode);
+
+	if (fieinfo->fi_flags & FIEMAP_FLAG_XATTR) {
+		ret = f2fs_xattr_fiemap(inode, fieinfo);
+		goto out;
+	}
+
+	if (f2fs_has_inline_data(inode)) {
+		ret = f2fs_inline_data_fiemap(inode, fieinfo, start, len);
+		if (ret != -EAGAIN)
+			goto out;
+	}
+
+	if (logical_to_blk(inode, len) == 0)
+		len = blk_to_logical(inode, 1);
+
+	start_blk = logical_to_blk(inode, start);
+	last_blk = logical_to_blk(inode, start + len - 1);
+
+next:
+	memset(&map_bh, 0, sizeof(struct buffer_head));
+	map_bh.b_size = len;
+
+	ret = get_data_block(inode, start_blk, &map_bh, 0,
+					F2FS_GET_BLOCK_FIEMAP, &next_pgofs);
+	if (ret)
+		goto out;
+
+	/* HOLE */
+	if (!buffer_mapped(&map_bh)) {
+		start_blk = next_pgofs;
+
+		if (blk_to_logical(inode, start_blk) < blk_to_logical(inode,
+					F2FS_I_SB(inode)->max_file_blocks))
+			goto prep_next;
+
+		flags |= FIEMAP_EXTENT_LAST;
+	}
+
+	if (size) {
+		if (f2fs_encrypted_inode(inode))
+			flags |= FIEMAP_EXTENT_DATA_ENCRYPTED;
+
+		ret = fiemap_fill_next_extent(fieinfo, logical,
+				phys, size, flags);
+	}
+
+	if (start_blk > last_blk || ret)
+		goto out;
+
+	logical = blk_to_logical(inode, start_blk);
+	phys = blk_to_logical(inode, map_bh.b_blocknr);
+	size = map_bh.b_size;
+	flags = 0;
+	if (buffer_unwritten(&map_bh))
+		flags = FIEMAP_EXTENT_UNWRITTEN;
+
+	start_blk += logical_to_blk(inode, size);
+
+prep_next:
+	cond_resched();
+	if (fatal_signal_pending(current))
+		ret = -EINTR;
+	else
+		goto next;
+out:
+	if (ret == 1)
+		ret = 0;
+
+	inode_unlock(inode);
+	return ret;
+}
+
+/*
+ * This function was originally taken from fs/mpage.c, and customized for f2fs.
+ * Major change was from block_size == page_size in f2fs by default.
+ */
+static int f2fs_mpage_readpages(struct address_space *mapping,
+			struct list_head *pages, struct page *page,
+			unsigned nr_pages)
+{
+	struct bio *bio = NULL;
+	sector_t last_block_in_bio = 0;
+	struct inode *inode = mapping->host;
+	const unsigned blkbits = inode->i_blkbits;
+	const unsigned blocksize = 1 << blkbits;
+	sector_t block_in_file;
+	sector_t last_block;
+	sector_t last_block_in_file;
+	sector_t block_nr;
+	struct f2fs_map_blocks map;
+
+	map.m_pblk = 0;
+	map.m_lblk = 0;
+	map.m_len = 0;
+	map.m_flags = 0;
+	map.m_next_pgofs = NULL;
+	map.m_next_extent = NULL;
+	map.m_seg_type = NO_CHECK_TYPE;
+
+	for (; nr_pages; nr_pages--) {
+		if (pages) {
+			page = list_last_entry(pages, struct page, lru);
+
+			prefetchw(&page->flags);
+			list_del(&page->lru);
+			if (add_to_page_cache_lru(page, mapping,
+						  page->index,
+						  readahead_gfp_mask(mapping)))
+				goto next_page;
+		}
+
+		block_in_file = (sector_t)page->index;
+		last_block = block_in_file + nr_pages;
+		last_block_in_file = (i_size_read(inode) + blocksize - 1) >>
+								blkbits;
+		if (last_block > last_block_in_file)
+			last_block = last_block_in_file;
+
+		/*
+		 * Map blocks using the previous result first.
+		 */
+		if ((map.m_flags & F2FS_MAP_MAPPED) &&
+				block_in_file > map.m_lblk &&
+				block_in_file < (map.m_lblk + map.m_len))
+			goto got_it;
+
+		/*
+		 * Then do more f2fs_map_blocks() calls until we are
+		 * done with this page.
+		 */
+		map.m_flags = 0;
+
+		if (block_in_file < last_block) {
+			map.m_lblk = block_in_file;
+			map.m_len = last_block - block_in_file;
+
+			if (f2fs_map_blocks(inode, &map, 0,
+						F2FS_GET_BLOCK_DEFAULT))
+				goto set_error_page;
+		}
+got_it:
+		if ((map.m_flags & F2FS_MAP_MAPPED)) {
+			block_nr = map.m_pblk + block_in_file - map.m_lblk;
+			SetPageMappedToDisk(page);
+
+			if (!PageUptodate(page) && !cleancache_get_page(page)) {
+				SetPageUptodate(page);
+				goto confused;
+			}
+
+			if (!f2fs_is_valid_blkaddr(F2FS_I_SB(inode), block_nr,
+								DATA_GENERIC))
+				goto set_error_page;
+		} else {
+			zero_user_segment(page, 0, PAGE_SIZE);
+			if (!PageUptodate(page))
+				SetPageUptodate(page);
+			unlock_page(page);
+			goto next_page;
+		}
+
+		/*
+		 * This page will go to BIO.  Do we need to send this
+		 * BIO off first?
+		 */
+		if (bio && (last_block_in_bio != block_nr - 1 ||
+			!__same_bdev(F2FS_I_SB(inode), block_nr, bio))) {
+submit_and_realloc:
+			__submit_bio(F2FS_I_SB(inode), bio, DATA);
+			bio = NULL;
+		}
+		if (bio == NULL) {
+			bio = f2fs_grab_read_bio(inode, block_nr, nr_pages);
+			if (IS_ERR(bio)) {
+				bio = NULL;
+				goto set_error_page;
+			}
+		}
+
+		if (bio_add_page(bio, page, blocksize, 0) < blocksize)
+			goto submit_and_realloc;
+
+		last_block_in_bio = block_nr;
+		goto next_page;
+set_error_page:
+		SetPageError(page);
+		zero_user_segment(page, 0, PAGE_SIZE);
+		unlock_page(page);
+		goto next_page;
+confused:
+		if (bio) {
+			__submit_bio(F2FS_I_SB(inode), bio, DATA);
+			bio = NULL;
+		}
+		unlock_page(page);
+next_page:
+		if (pages)
+			put_page(page);
+	}
+	BUG_ON(pages && !list_empty(pages));
+	if (bio)
+		__submit_bio(F2FS_I_SB(inode), bio, DATA);
+	return 0;
+}
+
+static int f2fs_read_data_page(struct file *file, struct page *page)
+{
+	struct inode *inode = page->mapping->host;
+	int ret = -EAGAIN;
+
+	trace_f2fs_readpage(page, DATA);
+
+	/* If the file has inline data, try to read it directly */
+	if (f2fs_has_inline_data(inode))
+		ret = f2fs_read_inline_data(inode, page);
+	if (ret == -EAGAIN)
+		ret = f2fs_mpage_readpages(page->mapping, NULL, page, 1);
+	return ret;
+}
+
+static int f2fs_read_data_pages(struct file *file,
+			struct address_space *mapping,
+			struct list_head *pages, unsigned nr_pages)
+{
+	struct inode *inode = mapping->host;
+	struct page *page = list_last_entry(pages, struct page, lru);
+
+	trace_f2fs_readpages(inode, page, nr_pages);
+
+	/* If the file has inline data, skip readpages */
+	if (f2fs_has_inline_data(inode))
+		return 0;
+
+	return f2fs_mpage_readpages(mapping, pages, NULL, nr_pages);
+}
+
+static int encrypt_one_page(struct f2fs_io_info *fio)
+{
+	struct inode *inode = fio->page->mapping->host;
+	gfp_t gfp_flags = GFP_NOFS;
+
+	if (!f2fs_encrypted_file(inode))
+		return 0;
+
+	/* wait for GCed page writeback via META_MAPPING */
+	f2fs_wait_on_block_writeback(fio->sbi, fio->old_blkaddr);
+
+retry_encrypt:
+	fio->encrypted_page = fscrypt_encrypt_page(inode, fio->page,
+			PAGE_SIZE, 0, fio->page->index, gfp_flags);
+	if (!IS_ERR(fio->encrypted_page))
+		return 0;
+
+	/* flush pending IOs and wait for a while in the ENOMEM case */
+	if (PTR_ERR(fio->encrypted_page) == -ENOMEM) {
+		f2fs_flush_merged_writes(fio->sbi);
+		congestion_wait(BLK_RW_ASYNC, HZ/50);
+		gfp_flags |= __GFP_NOFAIL;
+		goto retry_encrypt;
+	}
+	return PTR_ERR(fio->encrypted_page);
+}
+
+static inline bool check_inplace_update_policy(struct inode *inode,
+				struct f2fs_io_info *fio)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	unsigned int policy = SM_I(sbi)->ipu_policy;
+
+	if (policy & (0x1 << F2FS_IPU_FORCE))
+		return true;
+	if (policy & (0x1 << F2FS_IPU_SSR) && need_SSR(sbi))
+		return true;
+	if (policy & (0x1 << F2FS_IPU_UTIL) &&
+			utilization(sbi) > SM_I(sbi)->min_ipu_util)
+		return true;
+	if (policy & (0x1 << F2FS_IPU_SSR_UTIL) && need_SSR(sbi) &&
+			utilization(sbi) > SM_I(sbi)->min_ipu_util)
+		return true;
+
+	/*
+	 * IPU for rewrite async pages
+	 */
+	if (policy & (0x1 << F2FS_IPU_ASYNC) &&
+			fio && fio->op == REQ_OP_WRITE &&
+			!(fio->op_flags & REQ_SYNC) &&
+			!f2fs_encrypted_inode(inode))
+		return true;
+
+	/* this is only set during fdatasync */
+	if (policy & (0x1 << F2FS_IPU_FSYNC) &&
+			is_inode_flag_set(inode, FI_NEED_IPU))
+		return true;
+
+	return false;
+}
+
+bool should_update_inplace(struct inode *inode, struct f2fs_io_info *fio)
+{
+	if (f2fs_is_pinned_file(inode))
+		return true;
+
+	/* if this is cold file, we should overwrite to avoid fragmentation */
+	if (file_is_cold(inode))
+		return true;
+
+	return check_inplace_update_policy(inode, fio);
+}
+
+bool should_update_outplace(struct inode *inode, struct f2fs_io_info *fio)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+
+	if (test_opt(sbi, LFS))
+		return true;
+	if (S_ISDIR(inode->i_mode))
+		return true;
+	if (f2fs_is_atomic_file(inode))
+		return true;
+	if (fio) {
+		if (is_cold_data(fio->page))
+			return true;
+		if (IS_ATOMIC_WRITTEN_PAGE(fio->page))
+			return true;
+	}
+	return false;
+}
+
+static inline bool need_inplace_update(struct f2fs_io_info *fio)
+{
+	struct inode *inode = fio->page->mapping->host;
+
+	if (should_update_outplace(inode, fio))
+		return false;
+
+	return should_update_inplace(inode, fio);
+}
+
+int do_write_data_page(struct f2fs_io_info *fio)
+{
+	struct page *page = fio->page;
+	struct inode *inode = page->mapping->host;
+	struct dnode_of_data dn;
+	struct extent_info ei = {0,0,0};
+	bool ipu_force = false;
+	int err = 0;
+
+	set_new_dnode(&dn, inode, NULL, NULL, 0);
+	if (need_inplace_update(fio) &&
+			f2fs_lookup_extent_cache(inode, page->index, &ei)) {
+		fio->old_blkaddr = ei.blk + page->index - ei.fofs;
+
+		if (!f2fs_is_valid_blkaddr(fio->sbi, fio->old_blkaddr,
+							DATA_GENERIC))
+			return -EFSCORRUPTED;
+
+		ipu_force = true;
+		fio->need_lock = LOCK_DONE;
+		goto got_it;
+	}
+
+	/* Deadlock due to between page->lock and f2fs_lock_op */
+	if (fio->need_lock == LOCK_REQ && !f2fs_trylock_op(fio->sbi))
+		return -EAGAIN;
+
+	err = get_dnode_of_data(&dn, page->index, LOOKUP_NODE);
+	if (err)
+		goto out;
+
+	fio->old_blkaddr = dn.data_blkaddr;
+
+	/* This page is already truncated */
+	if (fio->old_blkaddr == NULL_ADDR) {
+		ClearPageUptodate(page);
+		clear_cold_data(page);
+		goto out_writepage;
+	}
+got_it:
+	if (__is_valid_data_blkaddr(fio->old_blkaddr) &&
+		!f2fs_is_valid_blkaddr(fio->sbi, fio->old_blkaddr,
+							DATA_GENERIC)) {
+		err = -EFSCORRUPTED;
+		goto out_writepage;
+	}
+	/*
+	 * If current allocation needs SSR,
+	 * it had better in-place writes for updated data.
+	 */
+	if (ipu_force || (is_valid_data_blkaddr(fio->sbi, fio->old_blkaddr) &&
+					need_inplace_update(fio))) {
+		err = encrypt_one_page(fio);
+		if (err)
+			goto out_writepage;
+
+		set_page_writeback(page);
+		ClearPageError(page);
+		f2fs_put_dnode(&dn);
+		if (fio->need_lock == LOCK_REQ)
+			f2fs_unlock_op(fio->sbi);
+		err = rewrite_data_page(fio);
+		trace_f2fs_do_write_data_page(fio->page, IPU);
+		set_inode_flag(inode, FI_UPDATE_WRITE);
+		return err;
+	}
+
+	if (fio->need_lock == LOCK_RETRY) {
+		if (!f2fs_trylock_op(fio->sbi)) {
+			err = -EAGAIN;
+			goto out_writepage;
+		}
+		fio->need_lock = LOCK_REQ;
+	}
+
+	err = encrypt_one_page(fio);
+	if (err)
+		goto out_writepage;
+
+	set_page_writeback(page);
+	ClearPageError(page);
+
+	/* LFS mode write path */
+	write_data_page(&dn, fio);
+	trace_f2fs_do_write_data_page(page, OPU);
+	set_inode_flag(inode, FI_APPEND_WRITE);
+	if (page->index == 0)
+		set_inode_flag(inode, FI_FIRST_BLOCK_WRITTEN);
+out_writepage:
+	f2fs_put_dnode(&dn);
+out:
+	if (fio->need_lock == LOCK_REQ)
+		f2fs_unlock_op(fio->sbi);
+	return err;
+}
+
+static int __write_data_page(struct page *page, bool *submitted,
+				struct writeback_control *wbc,
+				enum iostat_type io_type)
+{
+	struct inode *inode = page->mapping->host;
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	loff_t i_size = i_size_read(inode);
+	const pgoff_t end_index = ((unsigned long long) i_size)
+							>> PAGE_SHIFT;
+	loff_t psize = (loff_t)(page->index + 1) << PAGE_SHIFT;
+	unsigned offset = 0;
+	bool need_balance_fs = false;
+	int err = 0;
+	struct f2fs_io_info fio = {
+		.sbi = sbi,
+		.ino = inode->i_ino,
+		.type = DATA,
+		.op = REQ_OP_WRITE,
+		.op_flags = wbc_to_write_flags(wbc),
+		.old_blkaddr = NULL_ADDR,
+		.page = page,
+		.encrypted_page = NULL,
+		.submitted = false,
+		.need_lock = LOCK_RETRY,
+		.io_type = io_type,
+		.io_wbc = wbc,
+	};
+
+	trace_f2fs_writepage(page, DATA);
+
+	/* we should bypass data pages to proceed the kworkder jobs */
+	if (unlikely(f2fs_cp_error(sbi))) {
+		mapping_set_error(page->mapping, -EIO);
+		goto out;
+	}
+
+	if (unlikely(is_sbi_flag_set(sbi, SBI_POR_DOING)))
+		goto redirty_out;
+
+	if (page->index < end_index)
+		goto write;
+
+	/*
+	 * If the offset is out-of-range of file size,
+	 * this page does not have to be written to disk.
+	 */
+	offset = i_size & (PAGE_SIZE - 1);
+	if ((page->index >= end_index + 1) || !offset)
+		goto out;
+
+	zero_user_segment(page, offset, PAGE_SIZE);
+write:
+	if (f2fs_is_drop_cache(inode))
+		goto out;
+	/* we should not write 0'th page having journal header */
+	if (f2fs_is_volatile_file(inode) && (!page->index ||
+			(!wbc->for_reclaim &&
+			available_free_memory(sbi, BASE_CHECK))))
+		goto redirty_out;
+
+	/* Dentry blocks are controlled by checkpoint */
+	if (S_ISDIR(inode->i_mode)) {
+		fio.need_lock = LOCK_DONE;
+		err = do_write_data_page(&fio);
+		goto done;
+	}
+
+	if (!wbc->for_reclaim)
+		need_balance_fs = true;
+	else if (has_not_enough_free_secs(sbi, 0, 0))
+		goto redirty_out;
+	else
+		set_inode_flag(inode, FI_HOT_DATA);
+
+	err = -EAGAIN;
+	if (f2fs_has_inline_data(inode)) {
+		err = f2fs_write_inline_data(inode, page);
+		if (!err)
+			goto out;
+	}
+
+	if (err == -EAGAIN) {
+		err = do_write_data_page(&fio);
+		if (err == -EAGAIN) {
+			fio.need_lock = LOCK_REQ;
+			err = do_write_data_page(&fio);
+		}
+	}
+
+	if (err) {
+		file_set_keep_isize(inode);
+	} else {
+		down_write(&F2FS_I(inode)->i_sem);
+		if (F2FS_I(inode)->last_disk_size < psize)
+			F2FS_I(inode)->last_disk_size = psize;
+		up_write(&F2FS_I(inode)->i_sem);
+	}
+
+done:
+	if (err && err != -ENOENT)
+		goto redirty_out;
+
+out:
+	inode_dec_dirty_pages(inode);
+	if (err) {
+		ClearPageUptodate(page);
+		clear_cold_data(page);
+	}
+
+	if (wbc->for_reclaim) {
+		f2fs_submit_merged_write_cond(sbi, inode, 0, page->index, DATA);
+		clear_inode_flag(inode, FI_HOT_DATA);
+		remove_dirty_inode(inode);
+		submitted = NULL;
+	}
+
+	unlock_page(page);
+	if (!S_ISDIR(inode->i_mode))
+		f2fs_balance_fs(sbi, need_balance_fs);
+
+	if (unlikely(f2fs_cp_error(sbi))) {
+		f2fs_submit_merged_write(sbi, DATA);
+		submitted = NULL;
+	}
+
+	if (submitted)
+		*submitted = fio.submitted;
+
+	return 0;
+
+redirty_out:
+	redirty_page_for_writepage(wbc, page);
+	/*
+	 * pageout() in MM traslates EAGAIN, so calls handle_write_error()
+	 * -> mapping_set_error() -> set_bit(AS_EIO, ...).
+	 * file_write_and_wait_range() will see EIO error, which is critical
+	 * to return value of fsync() followed by atomic_write failure to user.
+	 */
+	if (!err || wbc->for_reclaim)
+		return AOP_WRITEPAGE_ACTIVATE;
+	unlock_page(page);
+	return err;
+}
+
+static int f2fs_write_data_page(struct page *page,
+					struct writeback_control *wbc)
+{
+	return __write_data_page(page, NULL, wbc, FS_DATA_IO);
+}
+
+/*
+ * This function was copied from write_cche_pages from mm/page-writeback.c.
+ * The major change is making write step of cold data page separately from
+ * warm/hot data page.
+ */
+static int f2fs_write_cache_pages(struct address_space *mapping,
+					struct writeback_control *wbc,
+					enum iostat_type io_type)
+{
+	int ret = 0;
+	int done = 0;
+	struct pagevec pvec;
+	int nr_pages;
+	pgoff_t uninitialized_var(writeback_index);
+	pgoff_t index;
+	pgoff_t end;		/* Inclusive */
+	pgoff_t done_index;
+	pgoff_t last_idx = ULONG_MAX;
+	int cycled;
+	int range_whole = 0;
+	int tag;
+
+	pagevec_init(&pvec, 0);
+
+	if (get_dirty_pages(mapping->host) <=
+				SM_I(F2FS_M_SB(mapping))->min_hot_blocks)
+		set_inode_flag(mapping->host, FI_HOT_DATA);
+	else
+		clear_inode_flag(mapping->host, FI_HOT_DATA);
+
+	if (wbc->range_cyclic) {
+		writeback_index = mapping->writeback_index; /* prev offset */
+		index = writeback_index;
+		if (index == 0)
+			cycled = 1;
+		else
+			cycled = 0;
+		end = -1;
+	} else {
+		index = wbc->range_start >> PAGE_SHIFT;
+		end = wbc->range_end >> PAGE_SHIFT;
+		if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
+			range_whole = 1;
+		cycled = 1; /* ignore range_cyclic tests */
+	}
+	if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
+		tag = PAGECACHE_TAG_TOWRITE;
+	else
+		tag = PAGECACHE_TAG_DIRTY;
+retry:
+	if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
+		tag_pages_for_writeback(mapping, index, end);
+	done_index = index;
+	while (!done && (index <= end)) {
+		int i;
+
+		nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, tag,
+			      min(end - index, (pgoff_t)PAGEVEC_SIZE - 1) + 1);
+		if (nr_pages == 0)
+			break;
+
+		for (i = 0; i < nr_pages; i++) {
+			struct page *page = pvec.pages[i];
+			bool submitted = false;
+
+			if (page->index > end) {
+				done = 1;
+				break;
+			}
+
+			done_index = page->index;
+retry_write:
+			lock_page(page);
+
+			if (unlikely(page->mapping != mapping)) {
+continue_unlock:
+				unlock_page(page);
+				continue;
+			}
+
+			if (!PageDirty(page)) {
+				/* someone wrote it for us */
+				goto continue_unlock;
+			}
+
+			if (PageWriteback(page)) {
+				if (wbc->sync_mode != WB_SYNC_NONE)
+					f2fs_wait_on_page_writeback(page,
+								DATA, true);
+				else
+					goto continue_unlock;
+			}
+
+			BUG_ON(PageWriteback(page));
+			if (!clear_page_dirty_for_io(page))
+				goto continue_unlock;
+
+			ret = __write_data_page(page, &submitted, wbc, io_type);
+			if (unlikely(ret)) {
+				/*
+				 * keep nr_to_write, since vfs uses this to
+				 * get # of written pages.
+				 */
+				if (ret == AOP_WRITEPAGE_ACTIVATE) {
+					unlock_page(page);
+					ret = 0;
+					continue;
+				} else if (ret == -EAGAIN) {
+					ret = 0;
+					if (wbc->sync_mode == WB_SYNC_ALL) {
+						cond_resched();
+						congestion_wait(BLK_RW_ASYNC,
+									HZ/50);
+						goto retry_write;
+					}
+					continue;
+				}
+				done_index = page->index + 1;
+				done = 1;
+				break;
+			} else if (submitted) {
+				last_idx = page->index;
+			}
+
+			/* give a priority to WB_SYNC threads */
+			if ((atomic_read(&F2FS_M_SB(mapping)->wb_sync_req) ||
+					--wbc->nr_to_write <= 0) &&
+					wbc->sync_mode == WB_SYNC_NONE) {
+				done = 1;
+				break;
+			}
+		}
+		pagevec_release(&pvec);
+		cond_resched();
+	}
+
+	if (!cycled && !done) {
+		cycled = 1;
+		index = 0;
+		end = writeback_index - 1;
+		goto retry;
+	}
+	if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
+		mapping->writeback_index = done_index;
+
+	if (last_idx != ULONG_MAX)
+		f2fs_submit_merged_write_cond(F2FS_M_SB(mapping), mapping->host,
+						0, last_idx, DATA);
+
+	return ret;
+}
+
+int __f2fs_write_data_pages(struct address_space *mapping,
+						struct writeback_control *wbc,
+						enum iostat_type io_type)
+{
+	struct inode *inode = mapping->host;
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct blk_plug plug;
+	int ret;
+
+	/* deal with chardevs and other special file */
+	if (!mapping->a_ops->writepage)
+		return 0;
+
+	/* skip writing if there is no dirty page in this inode */
+	if (!get_dirty_pages(inode) && wbc->sync_mode == WB_SYNC_NONE)
+		return 0;
+
+	/* during POR, we don't need to trigger writepage at all. */
+	if (unlikely(is_sbi_flag_set(sbi, SBI_POR_DOING)))
+		goto skip_write;
+
+	if (S_ISDIR(inode->i_mode) && wbc->sync_mode == WB_SYNC_NONE &&
+			get_dirty_pages(inode) < nr_pages_to_skip(sbi, DATA) &&
+			available_free_memory(sbi, DIRTY_DENTS))
+		goto skip_write;
+
+	/* skip writing during file defragment */
+	if (is_inode_flag_set(inode, FI_DO_DEFRAG))
+		goto skip_write;
+
+	trace_f2fs_writepages(mapping->host, wbc, DATA);
+
+	/* to avoid spliting IOs due to mixed WB_SYNC_ALL and WB_SYNC_NONE */
+	if (wbc->sync_mode == WB_SYNC_ALL)
+		atomic_inc(&sbi->wb_sync_req);
+	else if (atomic_read(&sbi->wb_sync_req))
+		goto skip_write;
+
+	blk_start_plug(&plug);
+	ret = f2fs_write_cache_pages(mapping, wbc, io_type);
+	blk_finish_plug(&plug);
+
+	if (wbc->sync_mode == WB_SYNC_ALL)
+		atomic_dec(&sbi->wb_sync_req);
+	/*
+	 * if some pages were truncated, we cannot guarantee its mapping->host
+	 * to detect pending bios.
+	 */
+
+	remove_dirty_inode(inode);
+	return ret;
+
+skip_write:
+	wbc->pages_skipped += get_dirty_pages(inode);
+	trace_f2fs_writepages(mapping->host, wbc, DATA);
+	return 0;
+}
+
+static int f2fs_write_data_pages(struct address_space *mapping,
+			    struct writeback_control *wbc)
+{
+	struct inode *inode = mapping->host;
+
+	return __f2fs_write_data_pages(mapping, wbc,
+			F2FS_I(inode)->cp_task == current ?
+			FS_CP_DATA_IO : FS_DATA_IO);
+}
+
+static void f2fs_write_failed(struct address_space *mapping, loff_t to)
+{
+	struct inode *inode = mapping->host;
+	loff_t i_size = i_size_read(inode);
+
+	if (to > i_size) {
+		down_write(&F2FS_I(inode)->i_mmap_sem);
+		truncate_pagecache(inode, i_size);
+		truncate_blocks(inode, i_size, true);
+		up_write(&F2FS_I(inode)->i_mmap_sem);
+	}
+}
+
+static int prepare_write_begin(struct f2fs_sb_info *sbi,
+			struct page *page, loff_t pos, unsigned len,
+			block_t *blk_addr, bool *node_changed)
+{
+	struct inode *inode = page->mapping->host;
+	pgoff_t index = page->index;
+	struct dnode_of_data dn;
+	struct page *ipage;
+	bool locked = false;
+	struct extent_info ei = {0,0,0};
+	int err = 0;
+	int flag;
+
+	/*
+	 * we already allocated all the blocks, so we don't need to get
+	 * the block addresses when there is no need to fill the page.
+	 */
+	if (!f2fs_has_inline_data(inode) && len == PAGE_SIZE &&
+			!is_inode_flag_set(inode, FI_NO_PREALLOC))
+		return 0;
+
+	/* f2fs_lock_op avoids race between write CP and convert_inline_page */
+	if (f2fs_has_inline_data(inode) && pos + len > MAX_INLINE_DATA(inode))
+		flag = F2FS_GET_BLOCK_DEFAULT;
+	else
+		flag = F2FS_GET_BLOCK_PRE_AIO;
+
+	if (f2fs_has_inline_data(inode) ||
+			(pos & PAGE_MASK) >= i_size_read(inode)) {
+		__do_map_lock(sbi, flag, true);
+		locked = true;
+	}
+restart:
+	/* check inline_data */
+	ipage = get_node_page(sbi, inode->i_ino);
+	if (IS_ERR(ipage)) {
+		err = PTR_ERR(ipage);
+		goto unlock_out;
+	}
+
+	set_new_dnode(&dn, inode, ipage, ipage, 0);
+
+	if (f2fs_has_inline_data(inode)) {
+		if (pos + len <= MAX_INLINE_DATA(inode)) {
+			read_inline_data(page, ipage);
+			set_inode_flag(inode, FI_DATA_EXIST);
+			if (inode->i_nlink)
+				set_inline_node(ipage);
+		} else {
+			err = f2fs_convert_inline_page(&dn, page);
+			if (err)
+				goto out;
+			if (dn.data_blkaddr == NULL_ADDR)
+				err = f2fs_get_block(&dn, index);
+		}
+	} else if (locked) {
+		err = f2fs_get_block(&dn, index);
+	} else {
+		if (f2fs_lookup_extent_cache(inode, index, &ei)) {
+			dn.data_blkaddr = ei.blk + index - ei.fofs;
+		} else {
+			/* hole case */
+			err = get_dnode_of_data(&dn, index, LOOKUP_NODE);
+			if (err || dn.data_blkaddr == NULL_ADDR) {
+				f2fs_put_dnode(&dn);
+				__do_map_lock(sbi, F2FS_GET_BLOCK_PRE_AIO,
+								true);
+				WARN_ON(flag != F2FS_GET_BLOCK_PRE_AIO);
+				locked = true;
+				goto restart;
+			}
+		}
+	}
+
+	/* convert_inline_page can make node_changed */
+	*blk_addr = dn.data_blkaddr;
+	*node_changed = dn.node_changed;
+out:
+	f2fs_put_dnode(&dn);
+unlock_out:
+	if (locked)
+		__do_map_lock(sbi, flag, false);
+	return err;
+}
+
+static int f2fs_write_begin(struct file *file, struct address_space *mapping,
+		loff_t pos, unsigned len, unsigned flags,
+		struct page **pagep, void **fsdata)
+{
+	struct inode *inode = mapping->host;
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct page *page = NULL;
+	pgoff_t index = ((unsigned long long) pos) >> PAGE_SHIFT;
+	bool need_balance = false, drop_atomic = false;
+	block_t blkaddr = NULL_ADDR;
+	int err = 0;
+
+	if (trace_android_fs_datawrite_start_enabled()) {
+		char *path, pathbuf[MAX_TRACE_PATHBUF_LEN];
+
+		path = android_fstrace_get_pathname(pathbuf,
+						    MAX_TRACE_PATHBUF_LEN,
+						    inode);
+		trace_android_fs_datawrite_start(inode, pos, len,
+						 current->pid, path,
+						 current->comm);
+	}
+	trace_f2fs_write_begin(inode, pos, len, flags);
+
+	if (f2fs_is_atomic_file(inode) &&
+			!available_free_memory(sbi, INMEM_PAGES)) {
+		err = -ENOMEM;
+		drop_atomic = true;
+		goto fail;
+	}
+
+	/*
+	 * We should check this at this moment to avoid deadlock on inode page
+	 * and #0 page. The locking rule for inline_data conversion should be:
+	 * lock_page(page #0) -> lock_page(inode_page)
+	 */
+	if (index != 0) {
+		err = f2fs_convert_inline_inode(inode);
+		if (err)
+			goto fail;
+	}
+repeat:
+	/*
+	 * Do not use grab_cache_page_write_begin() to avoid deadlock due to
+	 * wait_for_stable_page. Will wait that below with our IO control.
+	 */
+	page = f2fs_pagecache_get_page(mapping, index,
+				FGP_LOCK | FGP_WRITE | FGP_CREAT, GFP_NOFS);
+	if (!page) {
+		err = -ENOMEM;
+		goto fail;
+	}
+
+	*pagep = page;
+
+	err = prepare_write_begin(sbi, page, pos, len,
+					&blkaddr, &need_balance);
+	if (err)
+		goto fail;
+
+	if (need_balance && has_not_enough_free_secs(sbi, 0, 0)) {
+		unlock_page(page);
+		f2fs_balance_fs(sbi, true);
+		lock_page(page);
+		if (page->mapping != mapping) {
+			/* The page got truncated from under us */
+			f2fs_put_page(page, 1);
+			goto repeat;
+		}
+	}
+
+	f2fs_wait_on_page_writeback(page, DATA, false);
+
+	/* wait for GCed page writeback via META_MAPPING */
+	if (f2fs_post_read_required(inode))
+		f2fs_wait_on_block_writeback(sbi, blkaddr);
+
+	if (len == PAGE_SIZE || PageUptodate(page))
+		return 0;
+
+	if (!(pos & (PAGE_SIZE - 1)) && (pos + len) >= i_size_read(inode)) {
+		zero_user_segment(page, len, PAGE_SIZE);
+		return 0;
+	}
+
+	if (blkaddr == NEW_ADDR) {
+		zero_user_segment(page, 0, PAGE_SIZE);
+		SetPageUptodate(page);
+	} else {
+		err = f2fs_submit_page_read(inode, page, blkaddr);
+		if (err)
+			goto fail;
+
+		lock_page(page);
+		if (unlikely(page->mapping != mapping)) {
+			f2fs_put_page(page, 1);
+			goto repeat;
+		}
+		if (unlikely(!PageUptodate(page))) {
+			err = -EIO;
+			goto fail;
+		}
+	}
+	return 0;
+
+fail:
+	f2fs_put_page(page, 1);
+	f2fs_write_failed(mapping, pos + len);
+	if (drop_atomic)
+		drop_inmem_pages_all(sbi);
+	return err;
+}
+
+static int f2fs_write_end(struct file *file,
+			struct address_space *mapping,
+			loff_t pos, unsigned len, unsigned copied,
+			struct page *page, void *fsdata)
+{
+	struct inode *inode = page->mapping->host;
+
+	trace_android_fs_datawrite_end(inode, pos, len);
+	trace_f2fs_write_end(inode, pos, len, copied);
+
+	/*
+	 * This should be come from len == PAGE_SIZE, and we expect copied
+	 * should be PAGE_SIZE. Otherwise, we treat it with zero copied and
+	 * let generic_perform_write() try to copy data again through copied=0.
+	 */
+	if (!PageUptodate(page)) {
+		if (unlikely(copied != len))
+			copied = 0;
+		else
+			SetPageUptodate(page);
+	}
+	if (!copied)
+		goto unlock_out;
+
+	set_page_dirty(page);
+
+	if (pos + copied > i_size_read(inode))
+		f2fs_i_size_write(inode, pos + copied);
+unlock_out:
+	f2fs_put_page(page, 1);
+	f2fs_update_time(F2FS_I_SB(inode), REQ_TIME);
+	return copied;
+}
+
+static int check_direct_IO(struct inode *inode, struct iov_iter *iter,
+			   loff_t offset)
+{
+	unsigned blocksize_mask = inode->i_sb->s_blocksize - 1;
+
+	if (offset & blocksize_mask)
+		return -EINVAL;
+
+	if (iov_iter_alignment(iter) & blocksize_mask)
+		return -EINVAL;
+
+	return 0;
+}
+
+static ssize_t f2fs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
+{
+	struct address_space *mapping = iocb->ki_filp->f_mapping;
+	struct inode *inode = mapping->host;
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	size_t count = iov_iter_count(iter);
+	loff_t offset = iocb->ki_pos;
+	int rw = iov_iter_rw(iter);
+	int err;
+	enum rw_hint hint = iocb->ki_hint;
+	int whint_mode = F2FS_OPTION(sbi).whint_mode;
+
+	err = check_direct_IO(inode, iter, offset);
+	if (err)
+		return err;
+
+	if (f2fs_force_buffered_io(inode, rw))
+		return 0;
+
+	trace_f2fs_direct_IO_enter(inode, offset, count, rw);
+
+	if (trace_android_fs_dataread_start_enabled() &&
+	    (rw == READ)) {
+		char *path, pathbuf[MAX_TRACE_PATHBUF_LEN];
+
+		path = android_fstrace_get_pathname(pathbuf,
+						    MAX_TRACE_PATHBUF_LEN,
+						    inode);
+		trace_android_fs_dataread_start(inode, offset,
+						count, current->pid, path,
+						current->comm);
+	}
+	if (trace_android_fs_datawrite_start_enabled() &&
+	    (rw == WRITE)) {
+		char *path, pathbuf[MAX_TRACE_PATHBUF_LEN];
+
+		path = android_fstrace_get_pathname(pathbuf,
+						    MAX_TRACE_PATHBUF_LEN,
+						    inode);
+		trace_android_fs_datawrite_start(inode, offset, count,
+						 current->pid, path,
+						 current->comm);
+	}
+	if (rw == WRITE && whint_mode == WHINT_MODE_OFF)
+		iocb->ki_hint = WRITE_LIFE_NOT_SET;
+
+	if (!down_read_trylock(&F2FS_I(inode)->dio_rwsem[rw])) {
+		if (iocb->ki_flags & IOCB_NOWAIT) {
+			iocb->ki_hint = hint;
+			err = -EAGAIN;
+			goto out;
+		}
+		down_read(&F2FS_I(inode)->dio_rwsem[rw]);
+	}
+
+	err = blockdev_direct_IO(iocb, inode, iter, get_data_block_dio);
+	up_read(&F2FS_I(inode)->dio_rwsem[rw]);
+
+	if (rw == WRITE) {
+		if (whint_mode == WHINT_MODE_OFF)
+			iocb->ki_hint = hint;
+		if (err > 0) {
+			f2fs_update_iostat(F2FS_I_SB(inode), APP_DIRECT_IO,
+									err);
+			set_inode_flag(inode, FI_UPDATE_WRITE);
+		} else if (err < 0) {
+			f2fs_write_failed(mapping, offset + count);
+		}
+	}
+out:
+	if (trace_android_fs_dataread_start_enabled() &&
+	    (rw == READ))
+		trace_android_fs_dataread_end(inode, offset, count);
+	if (trace_android_fs_datawrite_start_enabled() &&
+	    (rw == WRITE))
+		trace_android_fs_datawrite_end(inode, offset, count);
+
+	trace_f2fs_direct_IO_exit(inode, offset, count, rw, err);
+
+	return err;
+}
+
+void f2fs_invalidate_page(struct page *page, unsigned int offset,
+							unsigned int length)
+{
+	struct inode *inode = page->mapping->host;
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+
+	if (inode->i_ino >= F2FS_ROOT_INO(sbi) &&
+		(offset % PAGE_SIZE || length != PAGE_SIZE))
+		return;
+
+	if (PageDirty(page)) {
+		if (inode->i_ino == F2FS_META_INO(sbi)) {
+			dec_page_count(sbi, F2FS_DIRTY_META);
+		} else if (inode->i_ino == F2FS_NODE_INO(sbi)) {
+			dec_page_count(sbi, F2FS_DIRTY_NODES);
+		} else {
+			inode_dec_dirty_pages(inode);
+			remove_dirty_inode(inode);
+		}
+	}
+
+	clear_cold_data(page);
+
+	/* This is atomic written page, keep Private */
+	if (IS_ATOMIC_WRITTEN_PAGE(page))
+		return drop_inmem_page(inode, page);
+
+	set_page_private(page, 0);
+	ClearPagePrivate(page);
+}
+
+int f2fs_release_page(struct page *page, gfp_t wait)
+{
+	/* If this is dirty page, keep PagePrivate */
+	if (PageDirty(page))
+		return 0;
+
+	/* This is atomic written page, keep Private */
+	if (IS_ATOMIC_WRITTEN_PAGE(page))
+		return 0;
+
+	clear_cold_data(page);
+	set_page_private(page, 0);
+	ClearPagePrivate(page);
+	return 1;
+}
+
+static int f2fs_set_data_page_dirty(struct page *page)
+{
+	struct address_space *mapping = page->mapping;
+	struct inode *inode = mapping->host;
+
+	trace_f2fs_set_page_dirty(page, DATA);
+
+	if (!PageUptodate(page))
+		SetPageUptodate(page);
+
+	if (f2fs_is_atomic_file(inode) && !f2fs_is_commit_atomic_write(inode)) {
+		if (!IS_ATOMIC_WRITTEN_PAGE(page)) {
+			register_inmem_page(inode, page);
+			return 1;
+		}
+		/*
+		 * Previously, this page has been registered, we just
+		 * return here.
+		 */
+		return 0;
+	}
+
+	if (!PageDirty(page)) {
+		__set_page_dirty_nobuffers(page);
+		update_dirty_page(inode, page);
+		return 1;
+	}
+	return 0;
+}
+
+static sector_t f2fs_bmap(struct address_space *mapping, sector_t block)
+{
+	struct inode *inode = mapping->host;
+
+	if (f2fs_has_inline_data(inode))
+		return 0;
+
+	/* make sure allocating whole blocks */
+	if (mapping_tagged(mapping, PAGECACHE_TAG_DIRTY))
+		filemap_write_and_wait(mapping);
+
+	return generic_block_bmap(mapping, block, get_data_block_bmap);
+}
+
+#ifdef CONFIG_MIGRATION
+#include <linux/migrate.h>
+
+int f2fs_migrate_page(struct address_space *mapping,
+		struct page *newpage, struct page *page, enum migrate_mode mode)
+{
+	int rc, extra_count;
+	struct f2fs_inode_info *fi = F2FS_I(mapping->host);
+	bool atomic_written = IS_ATOMIC_WRITTEN_PAGE(page);
+
+	BUG_ON(PageWriteback(page));
+
+	/* migrating an atomic written page is safe with the inmem_lock hold */
+	if (atomic_written) {
+		if (mode != MIGRATE_SYNC)
+			return -EBUSY;
+		if (!mutex_trylock(&fi->inmem_lock))
+			return -EAGAIN;
+	}
+
+	/*
+	 * A reference is expected if PagePrivate set when move mapping,
+	 * however F2FS breaks this for maintaining dirty page counts when
+	 * truncating pages. So here adjusting the 'extra_count' make it work.
+	 */
+	extra_count = (atomic_written ? 1 : 0) - page_has_private(page);
+	rc = migrate_page_move_mapping(mapping, newpage,
+				page, NULL, mode, extra_count);
+	if (rc != MIGRATEPAGE_SUCCESS) {
+		if (atomic_written)
+			mutex_unlock(&fi->inmem_lock);
+		return rc;
+	}
+
+	if (atomic_written) {
+		struct inmem_pages *cur;
+		list_for_each_entry(cur, &fi->inmem_pages, list)
+			if (cur->page == page) {
+				cur->page = newpage;
+				break;
+			}
+		mutex_unlock(&fi->inmem_lock);
+		put_page(page);
+		get_page(newpage);
+	}
+
+	if (PagePrivate(page))
+		SetPagePrivate(newpage);
+	set_page_private(newpage, page_private(page));
+
+	if (mode != MIGRATE_SYNC_NO_COPY)
+		migrate_page_copy(newpage, page);
+	else
+		migrate_page_states(newpage, page);
+
+	return MIGRATEPAGE_SUCCESS;
+}
+#endif
+
+const struct address_space_operations f2fs_dblock_aops = {
+	.readpage	= f2fs_read_data_page,
+	.readpages	= f2fs_read_data_pages,
+	.writepage	= f2fs_write_data_page,
+	.writepages	= f2fs_write_data_pages,
+	.write_begin	= f2fs_write_begin,
+	.write_end	= f2fs_write_end,
+	.set_page_dirty	= f2fs_set_data_page_dirty,
+	.invalidatepage	= f2fs_invalidate_page,
+	.releasepage	= f2fs_release_page,
+	.direct_IO	= f2fs_direct_IO,
+	.bmap		= f2fs_bmap,
+#ifdef CONFIG_MIGRATION
+	.migratepage    = f2fs_migrate_page,
+#endif
+};
+
+int __init f2fs_init_post_read_processing(void)
+{
+	bio_post_read_ctx_cache = KMEM_CACHE(bio_post_read_ctx, 0);
+	if (!bio_post_read_ctx_cache)
+		goto fail;
+	bio_post_read_ctx_pool =
+		mempool_create_slab_pool(NUM_PREALLOC_POST_READ_CTXS,
+					 bio_post_read_ctx_cache);
+	if (!bio_post_read_ctx_pool)
+		goto fail_free_cache;
+	return 0;
+
+fail_free_cache:
+	kmem_cache_destroy(bio_post_read_ctx_cache);
+fail:
+	return -ENOMEM;
+}
+
+void __exit f2fs_destroy_post_read_processing(void)
+{
+	mempool_destroy(bio_post_read_ctx_pool);
+	kmem_cache_destroy(bio_post_read_ctx_cache);
+}
diff --git a/src/kernel/linux/v4.14/fs/f2fs/debug.c b/src/kernel/linux/v4.14/fs/f2fs/debug.c
new file mode 100644
index 0000000..a66107b
--- /dev/null
+++ b/src/kernel/linux/v4.14/fs/f2fs/debug.c
@@ -0,0 +1,516 @@
+/*
+ * f2fs debugging statistics
+ *
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ *             http://www.samsung.com/
+ * Copyright (c) 2012 Linux Foundation
+ * Copyright (c) 2012 Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/fs.h>
+#include <linux/backing-dev.h>
+#include <linux/f2fs_fs.h>
+#include <linux/blkdev.h>
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
+
+#include "f2fs.h"
+#include "node.h"
+#include "segment.h"
+#include "gc.h"
+
+static LIST_HEAD(f2fs_stat_list);
+static struct dentry *f2fs_debugfs_root;
+static DEFINE_MUTEX(f2fs_stat_mutex);
+
+static void update_general_status(struct f2fs_sb_info *sbi)
+{
+	struct f2fs_stat_info *si = F2FS_STAT(sbi);
+	int i;
+
+	/* validation check of the segment numbers */
+	si->hit_largest = atomic64_read(&sbi->read_hit_largest);
+	si->hit_cached = atomic64_read(&sbi->read_hit_cached);
+	si->hit_rbtree = atomic64_read(&sbi->read_hit_rbtree);
+	si->hit_total = si->hit_largest + si->hit_cached + si->hit_rbtree;
+	si->total_ext = atomic64_read(&sbi->total_hit_ext);
+	si->ext_tree = atomic_read(&sbi->total_ext_tree);
+	si->zombie_tree = atomic_read(&sbi->total_zombie_tree);
+	si->ext_node = atomic_read(&sbi->total_ext_node);
+	si->ndirty_node = get_pages(sbi, F2FS_DIRTY_NODES);
+	si->ndirty_dent = get_pages(sbi, F2FS_DIRTY_DENTS);
+	si->ndirty_meta = get_pages(sbi, F2FS_DIRTY_META);
+	si->ndirty_data = get_pages(sbi, F2FS_DIRTY_DATA);
+	si->ndirty_qdata = get_pages(sbi, F2FS_DIRTY_QDATA);
+	si->ndirty_imeta = get_pages(sbi, F2FS_DIRTY_IMETA);
+	si->ndirty_dirs = sbi->ndirty_inode[DIR_INODE];
+	si->ndirty_files = sbi->ndirty_inode[FILE_INODE];
+	si->nquota_files = sbi->nquota_files;
+	si->ndirty_all = sbi->ndirty_inode[DIRTY_META];
+	si->inmem_pages = get_pages(sbi, F2FS_INMEM_PAGES);
+	si->aw_cnt = atomic_read(&sbi->aw_cnt);
+	si->vw_cnt = atomic_read(&sbi->vw_cnt);
+	si->max_aw_cnt = atomic_read(&sbi->max_aw_cnt);
+	si->max_vw_cnt = atomic_read(&sbi->max_vw_cnt);
+	si->nr_wb_cp_data = get_pages(sbi, F2FS_WB_CP_DATA);
+	si->nr_wb_data = get_pages(sbi, F2FS_WB_DATA);
+	if (SM_I(sbi) && SM_I(sbi)->fcc_info) {
+		si->nr_flushed =
+			atomic_read(&SM_I(sbi)->fcc_info->issued_flush);
+		si->nr_flushing =
+			atomic_read(&SM_I(sbi)->fcc_info->issing_flush);
+		si->flush_list_empty =
+			llist_empty(&SM_I(sbi)->fcc_info->issue_list);
+	}
+	if (SM_I(sbi) && SM_I(sbi)->dcc_info) {
+		si->nr_discarded =
+			atomic_read(&SM_I(sbi)->dcc_info->issued_discard);
+		si->nr_discarding =
+			atomic_read(&SM_I(sbi)->dcc_info->issing_discard);
+		si->nr_discard_cmd =
+			atomic_read(&SM_I(sbi)->dcc_info->discard_cmd_cnt);
+		si->undiscard_blks = SM_I(sbi)->dcc_info->undiscard_blks;
+	}
+	si->total_count = (int)sbi->user_block_count / sbi->blocks_per_seg;
+	si->rsvd_segs = reserved_segments(sbi);
+	si->overp_segs = overprovision_segments(sbi);
+	si->valid_count = valid_user_blocks(sbi);
+	si->discard_blks = discard_blocks(sbi);
+	si->valid_node_count = valid_node_count(sbi);
+	si->valid_inode_count = valid_inode_count(sbi);
+	si->inline_xattr = atomic_read(&sbi->inline_xattr);
+	si->inline_inode = atomic_read(&sbi->inline_inode);
+	si->inline_dir = atomic_read(&sbi->inline_dir);
+	si->append = sbi->im[APPEND_INO].ino_num;
+	si->update = sbi->im[UPDATE_INO].ino_num;
+	si->orphans = sbi->im[ORPHAN_INO].ino_num;
+	si->utilization = utilization(sbi);
+
+	si->free_segs = free_segments(sbi);
+	si->free_secs = free_sections(sbi);
+	si->prefree_count = prefree_segments(sbi);
+	si->dirty_count = dirty_segments(sbi);
+	si->node_pages = NODE_MAPPING(sbi)->nrpages;
+	si->meta_pages = META_MAPPING(sbi)->nrpages;
+	si->nats = NM_I(sbi)->nat_cnt;
+	si->dirty_nats = NM_I(sbi)->dirty_nat_cnt;
+	si->sits = MAIN_SEGS(sbi);
+	si->dirty_sits = SIT_I(sbi)->dirty_sentries;
+	si->free_nids = NM_I(sbi)->nid_cnt[FREE_NID];
+	si->avail_nids = NM_I(sbi)->available_nids;
+	si->alloc_nids = NM_I(sbi)->nid_cnt[PREALLOC_NID];
+	si->bg_gc = sbi->bg_gc;
+	si->util_free = (int)(free_user_blocks(sbi) >> sbi->log_blocks_per_seg)
+		* 100 / (int)(sbi->user_block_count >> sbi->log_blocks_per_seg)
+		/ 2;
+	si->util_valid = (int)(written_block_count(sbi) >>
+						sbi->log_blocks_per_seg)
+		* 100 / (int)(sbi->user_block_count >> sbi->log_blocks_per_seg)
+		/ 2;
+	si->util_invalid = 50 - si->util_free - si->util_valid;
+	for (i = CURSEG_HOT_DATA; i <= CURSEG_COLD_NODE; i++) {
+		struct curseg_info *curseg = CURSEG_I(sbi, i);
+		si->curseg[i] = curseg->segno;
+		si->cursec[i] = GET_SEC_FROM_SEG(sbi, curseg->segno);
+		si->curzone[i] = GET_ZONE_FROM_SEC(sbi, si->cursec[i]);
+	}
+
+	for (i = 0; i < 2; i++) {
+		si->segment_count[i] = sbi->segment_count[i];
+		si->block_count[i] = sbi->block_count[i];
+	}
+
+	si->inplace_count = atomic_read(&sbi->inplace_count);
+}
+
+/*
+ * This function calculates BDF of every segments
+ */
+static void update_sit_info(struct f2fs_sb_info *sbi)
+{
+	struct f2fs_stat_info *si = F2FS_STAT(sbi);
+	unsigned long long blks_per_sec, hblks_per_sec, total_vblocks;
+	unsigned long long bimodal, dist;
+	unsigned int segno, vblocks;
+	int ndirty = 0;
+
+	bimodal = 0;
+	total_vblocks = 0;
+	blks_per_sec = BLKS_PER_SEC(sbi);
+	hblks_per_sec = blks_per_sec / 2;
+	for (segno = 0; segno < MAIN_SEGS(sbi); segno += sbi->segs_per_sec) {
+		vblocks = get_valid_blocks(sbi, segno, true);
+		dist = abs(vblocks - hblks_per_sec);
+		bimodal += dist * dist;
+
+		if (vblocks > 0 && vblocks < blks_per_sec) {
+			total_vblocks += vblocks;
+			ndirty++;
+		}
+	}
+	dist = div_u64(MAIN_SECS(sbi) * hblks_per_sec * hblks_per_sec, 100);
+	si->bimodal = div64_u64(bimodal, dist);
+	if (si->dirty_count)
+		si->avg_vblocks = div_u64(total_vblocks, ndirty);
+	else
+		si->avg_vblocks = 0;
+}
+
+/*
+ * This function calculates memory footprint.
+ */
+static void update_mem_info(struct f2fs_sb_info *sbi)
+{
+	struct f2fs_stat_info *si = F2FS_STAT(sbi);
+	unsigned npages;
+	int i;
+
+	if (si->base_mem)
+		goto get_cache;
+
+	/* build stat */
+	si->base_mem = sizeof(struct f2fs_stat_info);
+
+	/* build superblock */
+	si->base_mem += sizeof(struct f2fs_sb_info) + sbi->sb->s_blocksize;
+	si->base_mem += 2 * sizeof(struct f2fs_inode_info);
+	si->base_mem += sizeof(*sbi->ckpt);
+
+	/* build sm */
+	si->base_mem += sizeof(struct f2fs_sm_info);
+
+	/* build sit */
+	si->base_mem += sizeof(struct sit_info);
+	si->base_mem += MAIN_SEGS(sbi) * sizeof(struct seg_entry);
+	si->base_mem += f2fs_bitmap_size(MAIN_SEGS(sbi));
+	si->base_mem += 2 * SIT_VBLOCK_MAP_SIZE * MAIN_SEGS(sbi);
+	if (f2fs_discard_en(sbi))
+		si->base_mem += SIT_VBLOCK_MAP_SIZE * MAIN_SEGS(sbi);
+	si->base_mem += SIT_VBLOCK_MAP_SIZE;
+	if (sbi->segs_per_sec > 1)
+		si->base_mem += MAIN_SECS(sbi) * sizeof(struct sec_entry);
+	si->base_mem += __bitmap_size(sbi, SIT_BITMAP);
+
+	/* build free segmap */
+	si->base_mem += sizeof(struct free_segmap_info);
+	si->base_mem += f2fs_bitmap_size(MAIN_SEGS(sbi));
+	si->base_mem += f2fs_bitmap_size(MAIN_SECS(sbi));
+
+	/* build curseg */
+	si->base_mem += sizeof(struct curseg_info) * NR_CURSEG_TYPE;
+	si->base_mem += PAGE_SIZE * NR_CURSEG_TYPE;
+
+	/* build dirty segmap */
+	si->base_mem += sizeof(struct dirty_seglist_info);
+	si->base_mem += NR_DIRTY_TYPE * f2fs_bitmap_size(MAIN_SEGS(sbi));
+	si->base_mem += f2fs_bitmap_size(MAIN_SECS(sbi));
+
+	/* build nm */
+	si->base_mem += sizeof(struct f2fs_nm_info);
+	si->base_mem += __bitmap_size(sbi, NAT_BITMAP);
+	si->base_mem += (NM_I(sbi)->nat_bits_blocks << F2FS_BLKSIZE_BITS);
+	si->base_mem += NM_I(sbi)->nat_blocks * NAT_ENTRY_BITMAP_SIZE;
+	si->base_mem += NM_I(sbi)->nat_blocks / 8;
+	si->base_mem += NM_I(sbi)->nat_blocks * sizeof(unsigned short);
+
+get_cache:
+	si->cache_mem = 0;
+
+	/* build gc */
+	if (sbi->gc_thread)
+		si->cache_mem += sizeof(struct f2fs_gc_kthread);
+
+	/* build merge flush thread */
+	if (SM_I(sbi)->fcc_info)
+		si->cache_mem += sizeof(struct flush_cmd_control);
+	if (SM_I(sbi)->dcc_info) {
+		si->cache_mem += sizeof(struct discard_cmd_control);
+		si->cache_mem += sizeof(struct discard_cmd) *
+			atomic_read(&SM_I(sbi)->dcc_info->discard_cmd_cnt);
+	}
+
+	/* free nids */
+	si->cache_mem += (NM_I(sbi)->nid_cnt[FREE_NID] +
+				NM_I(sbi)->nid_cnt[PREALLOC_NID]) *
+				sizeof(struct free_nid);
+	si->cache_mem += NM_I(sbi)->nat_cnt * sizeof(struct nat_entry);
+	si->cache_mem += NM_I(sbi)->dirty_nat_cnt *
+					sizeof(struct nat_entry_set);
+	si->cache_mem += si->inmem_pages * sizeof(struct inmem_pages);
+	for (i = 0; i < MAX_INO_ENTRY; i++)
+		si->cache_mem += sbi->im[i].ino_num * sizeof(struct ino_entry);
+	si->cache_mem += atomic_read(&sbi->total_ext_tree) *
+						sizeof(struct extent_tree);
+	si->cache_mem += atomic_read(&sbi->total_ext_node) *
+						sizeof(struct extent_node);
+
+	si->page_mem = 0;
+	npages = NODE_MAPPING(sbi)->nrpages;
+	si->page_mem += (unsigned long long)npages << PAGE_SHIFT;
+	npages = META_MAPPING(sbi)->nrpages;
+	si->page_mem += (unsigned long long)npages << PAGE_SHIFT;
+}
+
+static int stat_show(struct seq_file *s, void *v)
+{
+	struct f2fs_stat_info *si;
+	int i = 0;
+	int j;
+
+	mutex_lock(&f2fs_stat_mutex);
+	list_for_each_entry(si, &f2fs_stat_list, stat_list) {
+		update_general_status(si->sbi);
+
+		seq_printf(s, "\n=====[ partition info(%pg). #%d, %s, CP: %s]=====\n",
+			si->sbi->sb->s_bdev, i++,
+			f2fs_readonly(si->sbi->sb) ? "RO": "RW",
+			f2fs_cp_error(si->sbi) ? "Error": "Good");
+		seq_printf(s, "[SB: 1] [CP: 2] [SIT: %d] [NAT: %d] ",
+			   si->sit_area_segs, si->nat_area_segs);
+		seq_printf(s, "[SSA: %d] [MAIN: %d",
+			   si->ssa_area_segs, si->main_area_segs);
+		seq_printf(s, "(OverProv:%d Resv:%d)]\n\n",
+			   si->overp_segs, si->rsvd_segs);
+		if (test_opt(si->sbi, DISCARD))
+			seq_printf(s, "Utilization: %u%% (%u valid blocks, %u discard blocks)\n",
+				si->utilization, si->valid_count, si->discard_blks);
+		else
+			seq_printf(s, "Utilization: %u%% (%u valid blocks)\n",
+				si->utilization, si->valid_count);
+
+		seq_printf(s, "  - Node: %u (Inode: %u, ",
+			   si->valid_node_count, si->valid_inode_count);
+		seq_printf(s, "Other: %u)\n  - Data: %u\n",
+			   si->valid_node_count - si->valid_inode_count,
+			   si->valid_count - si->valid_node_count);
+		seq_printf(s, "  - Inline_xattr Inode: %u\n",
+			   si->inline_xattr);
+		seq_printf(s, "  - Inline_data Inode: %u\n",
+			   si->inline_inode);
+		seq_printf(s, "  - Inline_dentry Inode: %u\n",
+			   si->inline_dir);
+		seq_printf(s, "  - Orphan/Append/Update Inode: %u, %u, %u\n",
+			   si->orphans, si->append, si->update);
+		seq_printf(s, "\nMain area: %d segs, %d secs %d zones\n",
+			   si->main_area_segs, si->main_area_sections,
+			   si->main_area_zones);
+		seq_printf(s, "  - COLD  data: %d, %d, %d\n",
+			   si->curseg[CURSEG_COLD_DATA],
+			   si->cursec[CURSEG_COLD_DATA],
+			   si->curzone[CURSEG_COLD_DATA]);
+		seq_printf(s, "  - WARM  data: %d, %d, %d\n",
+			   si->curseg[CURSEG_WARM_DATA],
+			   si->cursec[CURSEG_WARM_DATA],
+			   si->curzone[CURSEG_WARM_DATA]);
+		seq_printf(s, "  - HOT   data: %d, %d, %d\n",
+			   si->curseg[CURSEG_HOT_DATA],
+			   si->cursec[CURSEG_HOT_DATA],
+			   si->curzone[CURSEG_HOT_DATA]);
+		seq_printf(s, "  - Dir   dnode: %d, %d, %d\n",
+			   si->curseg[CURSEG_HOT_NODE],
+			   si->cursec[CURSEG_HOT_NODE],
+			   si->curzone[CURSEG_HOT_NODE]);
+		seq_printf(s, "  - File   dnode: %d, %d, %d\n",
+			   si->curseg[CURSEG_WARM_NODE],
+			   si->cursec[CURSEG_WARM_NODE],
+			   si->curzone[CURSEG_WARM_NODE]);
+		seq_printf(s, "  - Indir nodes: %d, %d, %d\n",
+			   si->curseg[CURSEG_COLD_NODE],
+			   si->cursec[CURSEG_COLD_NODE],
+			   si->curzone[CURSEG_COLD_NODE]);
+		seq_printf(s, "\n  - Valid: %d\n  - Dirty: %d\n",
+			   si->main_area_segs - si->dirty_count -
+			   si->prefree_count - si->free_segs,
+			   si->dirty_count);
+		seq_printf(s, "  - Prefree: %d\n  - Free: %d (%d)\n\n",
+			   si->prefree_count, si->free_segs, si->free_secs);
+		seq_printf(s, "CP calls: %d (BG: %d)\n",
+				si->cp_count, si->bg_cp_count);
+		seq_printf(s, "GC calls: %d (BG: %d)\n",
+			   si->call_count, si->bg_gc);
+		seq_printf(s, "  - data segments : %d (%d)\n",
+				si->data_segs, si->bg_data_segs);
+		seq_printf(s, "  - node segments : %d (%d)\n",
+				si->node_segs, si->bg_node_segs);
+		seq_printf(s, "Try to move %d blocks (BG: %d)\n", si->tot_blks,
+				si->bg_data_blks + si->bg_node_blks);
+		seq_printf(s, "  - data blocks : %d (%d)\n", si->data_blks,
+				si->bg_data_blks);
+		seq_printf(s, "  - node blocks : %d (%d)\n", si->node_blks,
+				si->bg_node_blks);
+		seq_puts(s, "\nExtent Cache:\n");
+		seq_printf(s, "  - Hit Count: L1-1:%llu L1-2:%llu L2:%llu\n",
+				si->hit_largest, si->hit_cached,
+				si->hit_rbtree);
+		seq_printf(s, "  - Hit Ratio: %llu%% (%llu / %llu)\n",
+				!si->total_ext ? 0 :
+				div64_u64(si->hit_total * 100, si->total_ext),
+				si->hit_total, si->total_ext);
+		seq_printf(s, "  - Inner Struct Count: tree: %d(%d), node: %d\n",
+				si->ext_tree, si->zombie_tree, si->ext_node);
+		seq_puts(s, "\nBalancing F2FS Async:\n");
+		seq_printf(s, "  - IO (CP: %4d, Data: %4d, Flush: (%4d %4d %4d), "
+			"Discard: (%4d %4d)) cmd: %4d undiscard:%4u\n",
+			   si->nr_wb_cp_data, si->nr_wb_data,
+			   si->nr_flushing, si->nr_flushed,
+			   si->flush_list_empty,
+			   si->nr_discarding, si->nr_discarded,
+			   si->nr_discard_cmd, si->undiscard_blks);
+		seq_printf(s, "  - inmem: %4d, atomic IO: %4d (Max. %4d), "
+			"volatile IO: %4d (Max. %4d)\n",
+			   si->inmem_pages, si->aw_cnt, si->max_aw_cnt,
+			   si->vw_cnt, si->max_vw_cnt);
+		seq_printf(s, "  - nodes: %4d in %4d\n",
+			   si->ndirty_node, si->node_pages);
+		seq_printf(s, "  - dents: %4d in dirs:%4d (%4d)\n",
+			   si->ndirty_dent, si->ndirty_dirs, si->ndirty_all);
+		seq_printf(s, "  - datas: %4d in files:%4d\n",
+			   si->ndirty_data, si->ndirty_files);
+		seq_printf(s, "  - quota datas: %4d in quota files:%4d\n",
+			   si->ndirty_qdata, si->nquota_files);
+		seq_printf(s, "  - meta: %4d in %4d\n",
+			   si->ndirty_meta, si->meta_pages);
+		seq_printf(s, "  - imeta: %4d\n",
+			   si->ndirty_imeta);
+		seq_printf(s, "  - NATs: %9d/%9d\n  - SITs: %9d/%9d\n",
+			   si->dirty_nats, si->nats, si->dirty_sits, si->sits);
+		seq_printf(s, "  - free_nids: %9d/%9d\n  - alloc_nids: %9d\n",
+			   si->free_nids, si->avail_nids, si->alloc_nids);
+		seq_puts(s, "\nDistribution of User Blocks:");
+		seq_puts(s, " [ valid | invalid | free ]\n");
+		seq_puts(s, "  [");
+
+		for (j = 0; j < si->util_valid; j++)
+			seq_putc(s, '-');
+		seq_putc(s, '|');
+
+		for (j = 0; j < si->util_invalid; j++)
+			seq_putc(s, '-');
+		seq_putc(s, '|');
+
+		for (j = 0; j < si->util_free; j++)
+			seq_putc(s, '-');
+		seq_puts(s, "]\n\n");
+		seq_printf(s, "IPU: %u blocks\n", si->inplace_count);
+		seq_printf(s, "SSR: %u blocks in %u segments\n",
+			   si->block_count[SSR], si->segment_count[SSR]);
+		seq_printf(s, "LFS: %u blocks in %u segments\n",
+			   si->block_count[LFS], si->segment_count[LFS]);
+
+		/* segment usage info */
+		update_sit_info(si->sbi);
+		seq_printf(s, "\nBDF: %u, avg. vblocks: %u\n",
+			   si->bimodal, si->avg_vblocks);
+
+		/* memory footprint */
+		update_mem_info(si->sbi);
+		seq_printf(s, "\nMemory: %llu KB\n",
+			(si->base_mem + si->cache_mem + si->page_mem) >> 10);
+		seq_printf(s, "  - static: %llu KB\n",
+				si->base_mem >> 10);
+		seq_printf(s, "  - cached: %llu KB\n",
+				si->cache_mem >> 10);
+		seq_printf(s, "  - paged : %llu KB\n",
+				si->page_mem >> 10);
+	}
+	mutex_unlock(&f2fs_stat_mutex);
+	return 0;
+}
+
+static int stat_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, stat_show, inode->i_private);
+}
+
+static const struct file_operations stat_fops = {
+	.owner = THIS_MODULE,
+	.open = stat_open,
+	.read = seq_read,
+	.llseek = seq_lseek,
+	.release = single_release,
+};
+
+int f2fs_build_stats(struct f2fs_sb_info *sbi)
+{
+	struct f2fs_super_block *raw_super = F2FS_RAW_SUPER(sbi);
+	struct f2fs_stat_info *si;
+
+	si = f2fs_kzalloc(sbi, sizeof(struct f2fs_stat_info), GFP_KERNEL);
+	if (!si)
+		return -ENOMEM;
+
+	si->all_area_segs = le32_to_cpu(raw_super->segment_count);
+	si->sit_area_segs = le32_to_cpu(raw_super->segment_count_sit);
+	si->nat_area_segs = le32_to_cpu(raw_super->segment_count_nat);
+	si->ssa_area_segs = le32_to_cpu(raw_super->segment_count_ssa);
+	si->main_area_segs = le32_to_cpu(raw_super->segment_count_main);
+	si->main_area_sections = le32_to_cpu(raw_super->section_count);
+	si->main_area_zones = si->main_area_sections /
+				le32_to_cpu(raw_super->secs_per_zone);
+	si->sbi = sbi;
+	sbi->stat_info = si;
+
+	atomic64_set(&sbi->total_hit_ext, 0);
+	atomic64_set(&sbi->read_hit_rbtree, 0);
+	atomic64_set(&sbi->read_hit_largest, 0);
+	atomic64_set(&sbi->read_hit_cached, 0);
+
+	atomic_set(&sbi->inline_xattr, 0);
+	atomic_set(&sbi->inline_inode, 0);
+	atomic_set(&sbi->inline_dir, 0);
+	atomic_set(&sbi->inplace_count, 0);
+
+	atomic_set(&sbi->aw_cnt, 0);
+	atomic_set(&sbi->vw_cnt, 0);
+	atomic_set(&sbi->max_aw_cnt, 0);
+	atomic_set(&sbi->max_vw_cnt, 0);
+
+	mutex_lock(&f2fs_stat_mutex);
+	list_add_tail(&si->stat_list, &f2fs_stat_list);
+	mutex_unlock(&f2fs_stat_mutex);
+
+	return 0;
+}
+
+void f2fs_destroy_stats(struct f2fs_sb_info *sbi)
+{
+	struct f2fs_stat_info *si = F2FS_STAT(sbi);
+
+	mutex_lock(&f2fs_stat_mutex);
+	list_del(&si->stat_list);
+	mutex_unlock(&f2fs_stat_mutex);
+
+	kfree(si);
+}
+
+int __init f2fs_create_root_stats(void)
+{
+	struct dentry *file;
+
+	f2fs_debugfs_root = debugfs_create_dir("f2fs", NULL);
+	if (!f2fs_debugfs_root)
+		return -ENOMEM;
+
+	file = debugfs_create_file("status", S_IRUGO, f2fs_debugfs_root,
+			NULL, &stat_fops);
+	if (!file) {
+		debugfs_remove(f2fs_debugfs_root);
+		f2fs_debugfs_root = NULL;
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+void f2fs_destroy_root_stats(void)
+{
+	if (!f2fs_debugfs_root)
+		return;
+
+	debugfs_remove_recursive(f2fs_debugfs_root);
+	f2fs_debugfs_root = NULL;
+}
diff --git a/src/kernel/linux/v4.14/fs/f2fs/dir.c b/src/kernel/linux/v4.14/fs/f2fs/dir.c
new file mode 100644
index 0000000..7e2264f
--- /dev/null
+++ b/src/kernel/linux/v4.14/fs/f2fs/dir.c
@@ -0,0 +1,942 @@
+/*
+ * fs/f2fs/dir.c
+ *
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ *             http://www.samsung.com/
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/fs.h>
+#include <linux/f2fs_fs.h>
+#include <linux/sched/signal.h>
+#include "f2fs.h"
+#include "node.h"
+#include "acl.h"
+#include "xattr.h"
+#include <trace/events/f2fs.h>
+
+static unsigned long dir_blocks(struct inode *inode)
+{
+	return ((unsigned long long) (i_size_read(inode) + PAGE_SIZE - 1))
+							>> PAGE_SHIFT;
+}
+
+static unsigned int dir_buckets(unsigned int level, int dir_level)
+{
+	if (level + dir_level < MAX_DIR_HASH_DEPTH / 2)
+		return 1 << (level + dir_level);
+	else
+		return MAX_DIR_BUCKETS;
+}
+
+static unsigned int bucket_blocks(unsigned int level)
+{
+	if (level < MAX_DIR_HASH_DEPTH / 2)
+		return 2;
+	else
+		return 4;
+}
+
+static unsigned char f2fs_filetype_table[F2FS_FT_MAX] = {
+	[F2FS_FT_UNKNOWN]	= DT_UNKNOWN,
+	[F2FS_FT_REG_FILE]	= DT_REG,
+	[F2FS_FT_DIR]		= DT_DIR,
+	[F2FS_FT_CHRDEV]	= DT_CHR,
+	[F2FS_FT_BLKDEV]	= DT_BLK,
+	[F2FS_FT_FIFO]		= DT_FIFO,
+	[F2FS_FT_SOCK]		= DT_SOCK,
+	[F2FS_FT_SYMLINK]	= DT_LNK,
+};
+
+static unsigned char f2fs_type_by_mode[S_IFMT >> S_SHIFT] = {
+	[S_IFREG >> S_SHIFT]	= F2FS_FT_REG_FILE,
+	[S_IFDIR >> S_SHIFT]	= F2FS_FT_DIR,
+	[S_IFCHR >> S_SHIFT]	= F2FS_FT_CHRDEV,
+	[S_IFBLK >> S_SHIFT]	= F2FS_FT_BLKDEV,
+	[S_IFIFO >> S_SHIFT]	= F2FS_FT_FIFO,
+	[S_IFSOCK >> S_SHIFT]	= F2FS_FT_SOCK,
+	[S_IFLNK >> S_SHIFT]	= F2FS_FT_SYMLINK,
+};
+
+void set_de_type(struct f2fs_dir_entry *de, umode_t mode)
+{
+	de->file_type = f2fs_type_by_mode[(mode & S_IFMT) >> S_SHIFT];
+}
+
+unsigned char get_de_type(struct f2fs_dir_entry *de)
+{
+	if (de->file_type < F2FS_FT_MAX)
+		return f2fs_filetype_table[de->file_type];
+	return DT_UNKNOWN;
+}
+
+static unsigned long dir_block_index(unsigned int level,
+				int dir_level, unsigned int idx)
+{
+	unsigned long i;
+	unsigned long bidx = 0;
+
+	for (i = 0; i < level; i++)
+		bidx += dir_buckets(i, dir_level) * bucket_blocks(i);
+	bidx += idx * bucket_blocks(level);
+	return bidx;
+}
+
+static struct f2fs_dir_entry *find_in_block(struct page *dentry_page,
+				struct fscrypt_name *fname,
+				f2fs_hash_t namehash,
+				int *max_slots,
+				struct page **res_page)
+{
+	struct f2fs_dentry_block *dentry_blk;
+	struct f2fs_dir_entry *de;
+	struct f2fs_dentry_ptr d;
+
+	dentry_blk = (struct f2fs_dentry_block *)page_address(dentry_page);
+
+	make_dentry_ptr_block(NULL, &d, dentry_blk);
+	de = find_target_dentry(fname, namehash, max_slots, &d);
+	if (de)
+		*res_page = dentry_page;
+
+	return de;
+}
+
+struct f2fs_dir_entry *find_target_dentry(struct fscrypt_name *fname,
+			f2fs_hash_t namehash, int *max_slots,
+			struct f2fs_dentry_ptr *d)
+{
+	struct f2fs_dir_entry *de;
+	unsigned long bit_pos = 0;
+	int max_len = 0;
+
+	if (max_slots)
+		*max_slots = 0;
+	while (bit_pos < d->max) {
+		if (!test_bit_le(bit_pos, d->bitmap)) {
+			bit_pos++;
+			max_len++;
+			continue;
+		}
+
+		de = &d->dentry[bit_pos];
+
+		if (unlikely(!de->name_len)) {
+			bit_pos++;
+			continue;
+		}
+
+		if (de->hash_code == namehash &&
+		    fscrypt_match_name(fname, d->filename[bit_pos],
+				       le16_to_cpu(de->name_len)))
+			goto found;
+
+		if (max_slots && max_len > *max_slots)
+			*max_slots = max_len;
+		max_len = 0;
+
+		bit_pos += GET_DENTRY_SLOTS(le16_to_cpu(de->name_len));
+	}
+
+	de = NULL;
+found:
+	if (max_slots && max_len > *max_slots)
+		*max_slots = max_len;
+	return de;
+}
+
+static struct f2fs_dir_entry *find_in_level(struct inode *dir,
+					unsigned int level,
+					struct fscrypt_name *fname,
+					struct page **res_page)
+{
+	struct qstr name = FSTR_TO_QSTR(&fname->disk_name);
+	int s = GET_DENTRY_SLOTS(name.len);
+	unsigned int nbucket, nblock;
+	unsigned int bidx, end_block;
+	struct page *dentry_page;
+	struct f2fs_dir_entry *de = NULL;
+	bool room = false;
+	int max_slots;
+	f2fs_hash_t namehash = f2fs_dentry_hash(&name, fname);
+
+	nbucket = dir_buckets(level, F2FS_I(dir)->i_dir_level);
+	nblock = bucket_blocks(level);
+
+	bidx = dir_block_index(level, F2FS_I(dir)->i_dir_level,
+					le32_to_cpu(namehash) % nbucket);
+	end_block = bidx + nblock;
+
+	for (; bidx < end_block; bidx++) {
+		/* no need to allocate new dentry pages to all the indices */
+		dentry_page = find_data_page(dir, bidx);
+		if (IS_ERR(dentry_page)) {
+			if (PTR_ERR(dentry_page) == -ENOENT) {
+				room = true;
+				continue;
+			} else {
+				*res_page = dentry_page;
+				break;
+			}
+		}
+
+		de = find_in_block(dentry_page, fname, namehash, &max_slots,
+								res_page);
+		if (de)
+			break;
+
+		if (max_slots >= s)
+			room = true;
+		f2fs_put_page(dentry_page, 0);
+	}
+
+	if (!de && room && F2FS_I(dir)->chash != namehash) {
+		F2FS_I(dir)->chash = namehash;
+		F2FS_I(dir)->clevel = level;
+	}
+
+	return de;
+}
+
+struct f2fs_dir_entry *__f2fs_find_entry(struct inode *dir,
+			struct fscrypt_name *fname, struct page **res_page)
+{
+	unsigned long npages = dir_blocks(dir);
+	struct f2fs_dir_entry *de = NULL;
+	unsigned int max_depth;
+	unsigned int level;
+
+	if (f2fs_has_inline_dentry(dir)) {
+		*res_page = NULL;
+		de = find_in_inline_dir(dir, fname, res_page);
+		goto out;
+	}
+
+	if (npages == 0) {
+		*res_page = NULL;
+		goto out;
+	}
+
+	max_depth = F2FS_I(dir)->i_current_depth;
+	if (unlikely(max_depth > MAX_DIR_HASH_DEPTH)) {
+		f2fs_msg(F2FS_I_SB(dir)->sb, KERN_WARNING,
+				"Corrupted max_depth of %lu: %u",
+				dir->i_ino, max_depth);
+		max_depth = MAX_DIR_HASH_DEPTH;
+		f2fs_i_depth_write(dir, max_depth);
+	}
+
+	for (level = 0; level < max_depth; level++) {
+		*res_page = NULL;
+		de = find_in_level(dir, level, fname, res_page);
+		if (de || IS_ERR(*res_page))
+			break;
+	}
+out:
+	/* This is to increase the speed of f2fs_create */
+	if (!de)
+		F2FS_I(dir)->task = current;
+	return de;
+}
+
+/*
+ * Find an entry in the specified directory with the wanted name.
+ * It returns the page where the entry was found (as a parameter - res_page),
+ * and the entry itself. Page is returned mapped and unlocked.
+ * Entry is guaranteed to be valid.
+ */
+struct f2fs_dir_entry *f2fs_find_entry(struct inode *dir,
+			const struct qstr *child, struct page **res_page)
+{
+	struct f2fs_dir_entry *de = NULL;
+	struct fscrypt_name fname;
+	int err;
+
+	err = fscrypt_setup_filename(dir, child, 1, &fname);
+	if (err) {
+		if (err == -ENOENT)
+			*res_page = NULL;
+		else
+			*res_page = ERR_PTR(err);
+		return NULL;
+	}
+
+	de = __f2fs_find_entry(dir, &fname, res_page);
+
+	fscrypt_free_filename(&fname);
+	return de;
+}
+
+struct f2fs_dir_entry *f2fs_parent_dir(struct inode *dir, struct page **p)
+{
+	struct qstr dotdot = QSTR_INIT("..", 2);
+
+	return f2fs_find_entry(dir, &dotdot, p);
+}
+
+ino_t f2fs_inode_by_name(struct inode *dir, const struct qstr *qstr,
+							struct page **page)
+{
+	ino_t res = 0;
+	struct f2fs_dir_entry *de;
+
+	de = f2fs_find_entry(dir, qstr, page);
+	if (de) {
+		res = le32_to_cpu(de->ino);
+		f2fs_put_page(*page, 0);
+	}
+
+	return res;
+}
+
+void f2fs_set_link(struct inode *dir, struct f2fs_dir_entry *de,
+		struct page *page, struct inode *inode)
+{
+	enum page_type type = f2fs_has_inline_dentry(dir) ? NODE : DATA;
+	lock_page(page);
+	f2fs_wait_on_page_writeback(page, type, true);
+	de->ino = cpu_to_le32(inode->i_ino);
+	set_de_type(de, inode->i_mode);
+	set_page_dirty(page);
+
+	dir->i_mtime = dir->i_ctime = current_time(dir);
+	f2fs_mark_inode_dirty_sync(dir, false);
+	f2fs_put_page(page, 1);
+}
+
+static void init_dent_inode(const struct qstr *name, struct page *ipage)
+{
+	struct f2fs_inode *ri;
+
+	f2fs_wait_on_page_writeback(ipage, NODE, true);
+
+	/* copy name info. to this inode page */
+	ri = F2FS_INODE(ipage);
+	ri->i_namelen = cpu_to_le32(name->len);
+	memcpy(ri->i_name, name->name, name->len);
+	set_page_dirty(ipage);
+}
+
+void do_make_empty_dir(struct inode *inode, struct inode *parent,
+					struct f2fs_dentry_ptr *d)
+{
+	struct qstr dot = QSTR_INIT(".", 1);
+	struct qstr dotdot = QSTR_INIT("..", 2);
+
+	/* update dirent of "." */
+	f2fs_update_dentry(inode->i_ino, inode->i_mode, d, &dot, 0, 0);
+
+	/* update dirent of ".." */
+	f2fs_update_dentry(parent->i_ino, parent->i_mode, d, &dotdot, 0, 1);
+}
+
+static int make_empty_dir(struct inode *inode,
+		struct inode *parent, struct page *page)
+{
+	struct page *dentry_page;
+	struct f2fs_dentry_block *dentry_blk;
+	struct f2fs_dentry_ptr d;
+
+	if (f2fs_has_inline_dentry(inode))
+		return make_empty_inline_dir(inode, parent, page);
+
+	dentry_page = get_new_data_page(inode, page, 0, true);
+	if (IS_ERR(dentry_page))
+		return PTR_ERR(dentry_page);
+
+	dentry_blk = page_address(dentry_page);
+
+	make_dentry_ptr_block(NULL, &d, dentry_blk);
+	do_make_empty_dir(inode, parent, &d);
+
+	set_page_dirty(dentry_page);
+	f2fs_put_page(dentry_page, 1);
+	return 0;
+}
+
+struct page *init_inode_metadata(struct inode *inode, struct inode *dir,
+			const struct qstr *new_name, const struct qstr *orig_name,
+			struct page *dpage)
+{
+	struct page *page;
+	int dummy_encrypt = DUMMY_ENCRYPTION_ENABLED(F2FS_I_SB(dir));
+	int err;
+
+	if (is_inode_flag_set(inode, FI_NEW_INODE)) {
+		page = new_inode_page(inode);
+		if (IS_ERR(page))
+			return page;
+
+		if (S_ISDIR(inode->i_mode)) {
+			/* in order to handle error case */
+			get_page(page);
+			err = make_empty_dir(inode, dir, page);
+			if (err) {
+				lock_page(page);
+				goto put_error;
+			}
+			put_page(page);
+		}
+
+		err = f2fs_init_acl(inode, dir, page, dpage);
+		if (err)
+			goto put_error;
+
+		err = f2fs_init_security(inode, dir, orig_name, page);
+		if (err)
+			goto put_error;
+
+		if ((f2fs_encrypted_inode(dir) || dummy_encrypt) &&
+					f2fs_may_encrypt(inode)) {
+			err = fscrypt_inherit_context(dir, inode, page, false);
+			if (err)
+				goto put_error;
+		}
+	} else {
+		page = get_node_page(F2FS_I_SB(dir), inode->i_ino);
+		if (IS_ERR(page))
+			return page;
+	}
+
+	if (new_name) {
+		init_dent_inode(new_name, page);
+		if (f2fs_encrypted_inode(dir))
+			file_set_enc_name(inode);
+	}
+
+	/*
+	 * This file should be checkpointed during fsync.
+	 * We lost i_pino from now on.
+	 */
+	if (is_inode_flag_set(inode, FI_INC_LINK)) {
+		if (!S_ISDIR(inode->i_mode))
+			file_lost_pino(inode);
+		/*
+		 * If link the tmpfile to alias through linkat path,
+		 * we should remove this inode from orphan list.
+		 */
+		if (inode->i_nlink == 0)
+			remove_orphan_inode(F2FS_I_SB(dir), inode->i_ino);
+		f2fs_i_links_write(inode, true);
+	}
+	return page;
+
+put_error:
+	clear_nlink(inode);
+	update_inode(inode, page);
+	f2fs_put_page(page, 1);
+	return ERR_PTR(err);
+}
+
+void update_parent_metadata(struct inode *dir, struct inode *inode,
+						unsigned int current_depth)
+{
+	if (inode && is_inode_flag_set(inode, FI_NEW_INODE)) {
+		if (S_ISDIR(inode->i_mode))
+			f2fs_i_links_write(dir, true);
+		clear_inode_flag(inode, FI_NEW_INODE);
+	}
+	dir->i_mtime = dir->i_ctime = current_time(dir);
+	f2fs_mark_inode_dirty_sync(dir, false);
+
+	if (F2FS_I(dir)->i_current_depth != current_depth)
+		f2fs_i_depth_write(dir, current_depth);
+
+	if (inode && is_inode_flag_set(inode, FI_INC_LINK))
+		clear_inode_flag(inode, FI_INC_LINK);
+}
+
+int room_for_filename(const void *bitmap, int slots, int max_slots)
+{
+	int bit_start = 0;
+	int zero_start, zero_end;
+next:
+	zero_start = find_next_zero_bit_le(bitmap, max_slots, bit_start);
+	if (zero_start >= max_slots)
+		return max_slots;
+
+	zero_end = find_next_bit_le(bitmap, max_slots, zero_start);
+	if (zero_end - zero_start >= slots)
+		return zero_start;
+
+	bit_start = zero_end + 1;
+
+	if (zero_end + 1 >= max_slots)
+		return max_slots;
+	goto next;
+}
+
+void f2fs_update_dentry(nid_t ino, umode_t mode, struct f2fs_dentry_ptr *d,
+				const struct qstr *name, f2fs_hash_t name_hash,
+				unsigned int bit_pos)
+{
+	struct f2fs_dir_entry *de;
+	int slots = GET_DENTRY_SLOTS(name->len);
+	int i;
+
+	de = &d->dentry[bit_pos];
+	de->hash_code = name_hash;
+	de->name_len = cpu_to_le16(name->len);
+	memcpy(d->filename[bit_pos], name->name, name->len);
+	de->ino = cpu_to_le32(ino);
+	set_de_type(de, mode);
+	for (i = 0; i < slots; i++) {
+		__set_bit_le(bit_pos + i, (void *)d->bitmap);
+		/* avoid wrong garbage data for readdir */
+		if (i)
+			(de + i)->name_len = 0;
+	}
+}
+
+int f2fs_add_regular_entry(struct inode *dir, const struct qstr *new_name,
+				const struct qstr *orig_name,
+				struct inode *inode, nid_t ino, umode_t mode)
+{
+	unsigned int bit_pos;
+	unsigned int level;
+	unsigned int current_depth;
+	unsigned long bidx, block;
+	f2fs_hash_t dentry_hash;
+	unsigned int nbucket, nblock;
+	struct page *dentry_page = NULL;
+	struct f2fs_dentry_block *dentry_blk = NULL;
+	struct f2fs_dentry_ptr d;
+	struct page *page = NULL;
+	int slots, err = 0;
+
+	level = 0;
+	slots = GET_DENTRY_SLOTS(new_name->len);
+	dentry_hash = f2fs_dentry_hash(new_name, NULL);
+
+	current_depth = F2FS_I(dir)->i_current_depth;
+	if (F2FS_I(dir)->chash == dentry_hash) {
+		level = F2FS_I(dir)->clevel;
+		F2FS_I(dir)->chash = 0;
+	}
+
+start:
+#ifdef CONFIG_F2FS_FAULT_INJECTION
+	if (time_to_inject(F2FS_I_SB(dir), FAULT_DIR_DEPTH)) {
+		f2fs_show_injection_info(FAULT_DIR_DEPTH);
+		return -ENOSPC;
+	}
+#endif
+	if (unlikely(current_depth == MAX_DIR_HASH_DEPTH))
+		return -ENOSPC;
+
+	/* Increase the depth, if required */
+	if (level == current_depth)
+		++current_depth;
+
+	nbucket = dir_buckets(level, F2FS_I(dir)->i_dir_level);
+	nblock = bucket_blocks(level);
+
+	bidx = dir_block_index(level, F2FS_I(dir)->i_dir_level,
+				(le32_to_cpu(dentry_hash) % nbucket));
+
+	for (block = bidx; block <= (bidx + nblock - 1); block++) {
+		dentry_page = get_new_data_page(dir, NULL, block, true);
+		if (IS_ERR(dentry_page))
+			return PTR_ERR(dentry_page);
+
+		dentry_blk = page_address(dentry_page);
+		bit_pos = room_for_filename(&dentry_blk->dentry_bitmap,
+						slots, NR_DENTRY_IN_BLOCK);
+		if (bit_pos < NR_DENTRY_IN_BLOCK)
+			goto add_dentry;
+
+		f2fs_put_page(dentry_page, 1);
+	}
+
+	/* Move to next level to find the empty slot for new dentry */
+	++level;
+	goto start;
+add_dentry:
+	f2fs_wait_on_page_writeback(dentry_page, DATA, true);
+
+	if (inode) {
+		down_write(&F2FS_I(inode)->i_sem);
+		page = init_inode_metadata(inode, dir, new_name,
+						orig_name, NULL);
+		if (IS_ERR(page)) {
+			err = PTR_ERR(page);
+			goto fail;
+		}
+	}
+
+	make_dentry_ptr_block(NULL, &d, dentry_blk);
+	f2fs_update_dentry(ino, mode, &d, new_name, dentry_hash, bit_pos);
+
+	set_page_dirty(dentry_page);
+
+	if (inode) {
+		f2fs_i_pino_write(inode, dir->i_ino);
+		f2fs_put_page(page, 1);
+	}
+
+	update_parent_metadata(dir, inode, current_depth);
+fail:
+	if (inode)
+		up_write(&F2FS_I(inode)->i_sem);
+
+	f2fs_put_page(dentry_page, 1);
+
+	return err;
+}
+
+int __f2fs_do_add_link(struct inode *dir, struct fscrypt_name *fname,
+				struct inode *inode, nid_t ino, umode_t mode)
+{
+	struct qstr new_name;
+	int err = -EAGAIN;
+
+	new_name.name = fname_name(fname);
+	new_name.len = fname_len(fname);
+
+	if (f2fs_has_inline_dentry(dir))
+		err = f2fs_add_inline_entry(dir, &new_name, fname->usr_fname,
+							inode, ino, mode);
+	if (err == -EAGAIN)
+		err = f2fs_add_regular_entry(dir, &new_name, fname->usr_fname,
+							inode, ino, mode);
+
+	f2fs_update_time(F2FS_I_SB(dir), REQ_TIME);
+	return err;
+}
+
+/*
+ * Caller should grab and release a rwsem by calling f2fs_lock_op() and
+ * f2fs_unlock_op().
+ */
+int __f2fs_add_link(struct inode *dir, const struct qstr *name,
+				struct inode *inode, nid_t ino, umode_t mode)
+{
+	struct fscrypt_name fname;
+	struct page *page = NULL;
+	struct f2fs_dir_entry *de = NULL;
+	int err;
+
+	err = fscrypt_setup_filename(dir, name, 0, &fname);
+	if (err)
+		return err;
+
+	/*
+	 * An immature stakable filesystem shows a race condition between lookup
+	 * and create. If we have same task when doing lookup and create, it's
+	 * definitely fine as expected by VFS normally. Otherwise, let's just
+	 * verify on-disk dentry one more time, which guarantees filesystem
+	 * consistency more.
+	 */
+	if (current != F2FS_I(dir)->task) {
+		de = __f2fs_find_entry(dir, &fname, &page);
+		F2FS_I(dir)->task = NULL;
+	}
+	if (de) {
+		f2fs_put_page(page, 0);
+		err = -EEXIST;
+	} else if (IS_ERR(page)) {
+		err = PTR_ERR(page);
+	} else {
+		err = __f2fs_do_add_link(dir, &fname, inode, ino, mode);
+	}
+	fscrypt_free_filename(&fname);
+	return err;
+}
+
+int f2fs_do_tmpfile(struct inode *inode, struct inode *dir)
+{
+	struct page *page;
+	int err = 0;
+
+	down_write(&F2FS_I(inode)->i_sem);
+	page = init_inode_metadata(inode, dir, NULL, NULL, NULL);
+	if (IS_ERR(page)) {
+		err = PTR_ERR(page);
+		goto fail;
+	}
+	f2fs_put_page(page, 1);
+
+	clear_inode_flag(inode, FI_NEW_INODE);
+fail:
+	up_write(&F2FS_I(inode)->i_sem);
+	f2fs_update_time(F2FS_I_SB(inode), REQ_TIME);
+	return err;
+}
+
+void f2fs_drop_nlink(struct inode *dir, struct inode *inode)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
+
+	down_write(&F2FS_I(inode)->i_sem);
+
+	if (S_ISDIR(inode->i_mode))
+		f2fs_i_links_write(dir, false);
+	inode->i_ctime = current_time(inode);
+
+	f2fs_i_links_write(inode, false);
+	if (S_ISDIR(inode->i_mode)) {
+		f2fs_i_links_write(inode, false);
+		f2fs_i_size_write(inode, 0);
+	}
+	up_write(&F2FS_I(inode)->i_sem);
+
+	if (inode->i_nlink == 0)
+		add_orphan_inode(inode);
+	else
+		release_orphan_inode(sbi);
+}
+
+/*
+ * It only removes the dentry from the dentry page, corresponding name
+ * entry in name page does not need to be touched during deletion.
+ */
+void f2fs_delete_entry(struct f2fs_dir_entry *dentry, struct page *page,
+					struct inode *dir, struct inode *inode)
+{
+	struct	f2fs_dentry_block *dentry_blk;
+	unsigned int bit_pos;
+	int slots = GET_DENTRY_SLOTS(le16_to_cpu(dentry->name_len));
+	struct address_space *mapping = page_mapping(page);
+	unsigned long flags;
+	int i;
+
+	f2fs_update_time(F2FS_I_SB(dir), REQ_TIME);
+
+	if (F2FS_OPTION(F2FS_I_SB(dir)).fsync_mode == FSYNC_MODE_STRICT)
+		add_ino_entry(F2FS_I_SB(dir), dir->i_ino, TRANS_DIR_INO);
+
+	if (f2fs_has_inline_dentry(dir))
+		return f2fs_delete_inline_entry(dentry, page, dir, inode);
+
+	lock_page(page);
+	f2fs_wait_on_page_writeback(page, DATA, true);
+
+	dentry_blk = page_address(page);
+	bit_pos = dentry - dentry_blk->dentry;
+	for (i = 0; i < slots; i++)
+		__clear_bit_le(bit_pos + i, &dentry_blk->dentry_bitmap);
+
+	/* Let's check and deallocate this dentry page */
+	bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap,
+			NR_DENTRY_IN_BLOCK,
+			0);
+	set_page_dirty(page);
+
+	dir->i_ctime = dir->i_mtime = current_time(dir);
+	f2fs_mark_inode_dirty_sync(dir, false);
+
+	if (inode)
+		f2fs_drop_nlink(dir, inode);
+
+	if (bit_pos == NR_DENTRY_IN_BLOCK &&
+			!truncate_hole(dir, page->index, page->index + 1)) {
+		spin_lock_irqsave(&mapping->tree_lock, flags);
+		radix_tree_tag_clear(&mapping->page_tree, page_index(page),
+				     PAGECACHE_TAG_DIRTY);
+		spin_unlock_irqrestore(&mapping->tree_lock, flags);
+
+		clear_page_dirty_for_io(page);
+		ClearPagePrivate(page);
+		ClearPageUptodate(page);
+		clear_cold_data(page);
+		inode_dec_dirty_pages(dir);
+		remove_dirty_inode(dir);
+	}
+	f2fs_put_page(page, 1);
+}
+
+bool f2fs_empty_dir(struct inode *dir)
+{
+	unsigned long bidx;
+	struct page *dentry_page;
+	unsigned int bit_pos;
+	struct f2fs_dentry_block *dentry_blk;
+	unsigned long nblock = dir_blocks(dir);
+
+	if (f2fs_has_inline_dentry(dir))
+		return f2fs_empty_inline_dir(dir);
+
+	for (bidx = 0; bidx < nblock; bidx++) {
+		dentry_page = get_lock_data_page(dir, bidx, false);
+		if (IS_ERR(dentry_page)) {
+			if (PTR_ERR(dentry_page) == -ENOENT)
+				continue;
+			else
+				return false;
+		}
+
+		dentry_blk = page_address(dentry_page);
+		if (bidx == 0)
+			bit_pos = 2;
+		else
+			bit_pos = 0;
+		bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap,
+						NR_DENTRY_IN_BLOCK,
+						bit_pos);
+
+		f2fs_put_page(dentry_page, 1);
+
+		if (bit_pos < NR_DENTRY_IN_BLOCK)
+			return false;
+	}
+	return true;
+}
+
+int f2fs_fill_dentries(struct dir_context *ctx, struct f2fs_dentry_ptr *d,
+			unsigned int start_pos, struct fscrypt_str *fstr)
+{
+	unsigned char d_type = DT_UNKNOWN;
+	unsigned int bit_pos;
+	struct f2fs_dir_entry *de = NULL;
+	struct fscrypt_str de_name = FSTR_INIT(NULL, 0);
+	struct f2fs_sb_info *sbi = F2FS_I_SB(d->inode);
+
+	bit_pos = ((unsigned long)ctx->pos % d->max);
+
+	while (bit_pos < d->max) {
+		bit_pos = find_next_bit_le(d->bitmap, d->max, bit_pos);
+		if (bit_pos >= d->max)
+			break;
+
+		de = &d->dentry[bit_pos];
+		if (de->name_len == 0) {
+			bit_pos++;
+			ctx->pos = start_pos + bit_pos;
+			continue;
+		}
+
+		d_type = get_de_type(de);
+
+		de_name.name = d->filename[bit_pos];
+		de_name.len = le16_to_cpu(de->name_len);
+
+		/* check memory boundary before moving forward */
+		bit_pos += GET_DENTRY_SLOTS(le16_to_cpu(de->name_len));
+		if (unlikely(bit_pos > d->max ||
+				le16_to_cpu(de->name_len) > F2FS_NAME_LEN)) {
+			f2fs_msg(F2FS_I_SB(d->inode)->sb, KERN_WARNING,
+				"%s: corrupted namelen=%d, run fsck to fix.",
+				__func__, le16_to_cpu(de->name_len));
+			set_sbi_flag(F2FS_I_SB(d->inode)->sb->s_fs_info, SBI_NEED_FSCK);
+			return -EINVAL;
+		}
+
+		if (f2fs_encrypted_inode(d->inode)) {
+			int save_len = fstr->len;
+			int err;
+
+			err = fscrypt_fname_disk_to_usr(d->inode,
+						(u32)de->hash_code, 0,
+						&de_name, fstr);
+			if (err)
+				return err;
+
+			de_name = *fstr;
+			fstr->len = save_len;
+		}
+
+		if (!dir_emit(ctx, de_name.name, de_name.len,
+					le32_to_cpu(de->ino), d_type))
+			return 1;
+
+		if (sbi->readdir_ra == 1)
+			ra_node_page(sbi, le32_to_cpu(de->ino));
+
+		ctx->pos = start_pos + bit_pos;
+	}
+	return 0;
+}
+
+static int f2fs_readdir(struct file *file, struct dir_context *ctx)
+{
+	struct inode *inode = file_inode(file);
+	unsigned long npages = dir_blocks(inode);
+	struct f2fs_dentry_block *dentry_blk = NULL;
+	struct page *dentry_page = NULL;
+	struct file_ra_state *ra = &file->f_ra;
+	loff_t start_pos = ctx->pos;
+	unsigned int n = ((unsigned long)ctx->pos / NR_DENTRY_IN_BLOCK);
+	struct f2fs_dentry_ptr d;
+	struct fscrypt_str fstr = FSTR_INIT(NULL, 0);
+	int err = 0;
+
+	if (f2fs_encrypted_inode(inode)) {
+		err = fscrypt_get_encryption_info(inode);
+		if (err && err != -ENOKEY)
+			goto out;
+
+		err = fscrypt_fname_alloc_buffer(inode, F2FS_NAME_LEN, &fstr);
+		if (err < 0)
+			goto out;
+	}
+
+	if (f2fs_has_inline_dentry(inode)) {
+		err = f2fs_read_inline_dir(file, ctx, &fstr);
+		goto out_free;
+	}
+
+	for (; n < npages; n++, ctx->pos = n * NR_DENTRY_IN_BLOCK) {
+
+		/* allow readdir() to be interrupted */
+		if (fatal_signal_pending(current)) {
+			err = -ERESTARTSYS;
+			goto out_free;
+		}
+		cond_resched();
+
+		/* readahead for multi pages of dir */
+		if (npages - n > 1 && !ra_has_index(ra, n))
+			page_cache_sync_readahead(inode->i_mapping, ra, file, n,
+				min(npages - n, (pgoff_t)MAX_DIR_RA_PAGES));
+
+		dentry_page = get_lock_data_page(inode, n, false);
+		if (IS_ERR(dentry_page)) {
+			err = PTR_ERR(dentry_page);
+			if (err == -ENOENT) {
+				err = 0;
+				continue;
+			} else {
+				goto out_free;
+			}
+		}
+
+		dentry_blk = page_address(dentry_page);
+
+		make_dentry_ptr_block(inode, &d, dentry_blk);
+
+		err = f2fs_fill_dentries(ctx, &d,
+				n * NR_DENTRY_IN_BLOCK, &fstr);
+		if (err) {
+			f2fs_put_page(dentry_page, 1);
+			break;
+		}
+
+		f2fs_put_page(dentry_page, 1);
+	}
+out_free:
+	fscrypt_fname_free_buffer(&fstr);
+out:
+	trace_f2fs_readdir(inode, start_pos, ctx->pos, err);
+	return err < 0 ? err : 0;
+}
+
+static int f2fs_dir_open(struct inode *inode, struct file *filp)
+{
+	if (f2fs_encrypted_inode(inode))
+		return fscrypt_get_encryption_info(inode) ? -EACCES : 0;
+	return 0;
+}
+
+const struct file_operations f2fs_dir_operations = {
+	.llseek		= generic_file_llseek,
+	.read		= generic_read_dir,
+	.iterate_shared	= f2fs_readdir,
+	.fsync		= f2fs_sync_file,
+	.open		= f2fs_dir_open,
+	.unlocked_ioctl	= f2fs_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl   = f2fs_compat_ioctl,
+#endif
+};
diff --git a/src/kernel/linux/v4.14/fs/f2fs/extent_cache.c b/src/kernel/linux/v4.14/fs/f2fs/extent_cache.c
new file mode 100644
index 0000000..d5a861b
--- /dev/null
+++ b/src/kernel/linux/v4.14/fs/f2fs/extent_cache.c
@@ -0,0 +1,822 @@
+/*
+ * f2fs extent cache support
+ *
+ * Copyright (c) 2015 Motorola Mobility
+ * Copyright (c) 2015 Samsung Electronics
+ * Authors: Jaegeuk Kim <jaegeuk@kernel.org>
+ *          Chao Yu <chao2.yu@samsung.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/fs.h>
+#include <linux/f2fs_fs.h>
+
+#include "f2fs.h"
+#include "node.h"
+#include <trace/events/f2fs.h>
+
+static struct rb_entry *__lookup_rb_tree_fast(struct rb_entry *cached_re,
+							unsigned int ofs)
+{
+	if (cached_re) {
+		if (cached_re->ofs <= ofs &&
+				cached_re->ofs + cached_re->len > ofs) {
+			return cached_re;
+		}
+	}
+	return NULL;
+}
+
+static struct rb_entry *__lookup_rb_tree_slow(struct rb_root *root,
+							unsigned int ofs)
+{
+	struct rb_node *node = root->rb_node;
+	struct rb_entry *re;
+
+	while (node) {
+		re = rb_entry(node, struct rb_entry, rb_node);
+
+		if (ofs < re->ofs)
+			node = node->rb_left;
+		else if (ofs >= re->ofs + re->len)
+			node = node->rb_right;
+		else
+			return re;
+	}
+	return NULL;
+}
+
+struct rb_entry *__lookup_rb_tree(struct rb_root *root,
+				struct rb_entry *cached_re, unsigned int ofs)
+{
+	struct rb_entry *re;
+
+	re = __lookup_rb_tree_fast(cached_re, ofs);
+	if (!re)
+		return __lookup_rb_tree_slow(root, ofs);
+
+	return re;
+}
+
+struct rb_node **__lookup_rb_tree_for_insert(struct f2fs_sb_info *sbi,
+				struct rb_root *root, struct rb_node **parent,
+				unsigned int ofs)
+{
+	struct rb_node **p = &root->rb_node;
+	struct rb_entry *re;
+
+	while (*p) {
+		*parent = *p;
+		re = rb_entry(*parent, struct rb_entry, rb_node);
+
+		if (ofs < re->ofs)
+			p = &(*p)->rb_left;
+		else if (ofs >= re->ofs + re->len)
+			p = &(*p)->rb_right;
+		else
+			f2fs_bug_on(sbi, 1);
+	}
+
+	return p;
+}
+
+/*
+ * lookup rb entry in position of @ofs in rb-tree,
+ * if hit, return the entry, otherwise, return NULL
+ * @prev_ex: extent before ofs
+ * @next_ex: extent after ofs
+ * @insert_p: insert point for new extent at ofs
+ * in order to simpfy the insertion after.
+ * tree must stay unchanged between lookup and insertion.
+ */
+struct rb_entry *__lookup_rb_tree_ret(struct rb_root *root,
+				struct rb_entry *cached_re,
+				unsigned int ofs,
+				struct rb_entry **prev_entry,
+				struct rb_entry **next_entry,
+				struct rb_node ***insert_p,
+				struct rb_node **insert_parent,
+				bool force)
+{
+	struct rb_node **pnode = &root->rb_node;
+	struct rb_node *parent = NULL, *tmp_node;
+	struct rb_entry *re = cached_re;
+
+	*insert_p = NULL;
+	*insert_parent = NULL;
+	*prev_entry = NULL;
+	*next_entry = NULL;
+
+	if (RB_EMPTY_ROOT(root))
+		return NULL;
+
+	if (re) {
+		if (re->ofs <= ofs && re->ofs + re->len > ofs)
+			goto lookup_neighbors;
+	}
+
+	while (*pnode) {
+		parent = *pnode;
+		re = rb_entry(*pnode, struct rb_entry, rb_node);
+
+		if (ofs < re->ofs)
+			pnode = &(*pnode)->rb_left;
+		else if (ofs >= re->ofs + re->len)
+			pnode = &(*pnode)->rb_right;
+		else
+			goto lookup_neighbors;
+	}
+
+	*insert_p = pnode;
+	*insert_parent = parent;
+
+	re = rb_entry(parent, struct rb_entry, rb_node);
+	tmp_node = parent;
+	if (parent && ofs > re->ofs)
+		tmp_node = rb_next(parent);
+	*next_entry = rb_entry_safe(tmp_node, struct rb_entry, rb_node);
+
+	tmp_node = parent;
+	if (parent && ofs < re->ofs)
+		tmp_node = rb_prev(parent);
+	*prev_entry = rb_entry_safe(tmp_node, struct rb_entry, rb_node);
+	return NULL;
+
+lookup_neighbors:
+	if (ofs == re->ofs || force) {
+		/* lookup prev node for merging backward later */
+		tmp_node = rb_prev(&re->rb_node);
+		*prev_entry = rb_entry_safe(tmp_node, struct rb_entry, rb_node);
+	}
+	if (ofs == re->ofs + re->len - 1 || force) {
+		/* lookup next node for merging frontward later */
+		tmp_node = rb_next(&re->rb_node);
+		*next_entry = rb_entry_safe(tmp_node, struct rb_entry, rb_node);
+	}
+	return re;
+}
+
+bool __check_rb_tree_consistence(struct f2fs_sb_info *sbi,
+						struct rb_root *root)
+{
+#ifdef CONFIG_F2FS_CHECK_FS
+	struct rb_node *cur = rb_first(root), *next;
+	struct rb_entry *cur_re, *next_re;
+
+	if (!cur)
+		return true;
+
+	while (cur) {
+		next = rb_next(cur);
+		if (!next)
+			return true;
+
+		cur_re = rb_entry(cur, struct rb_entry, rb_node);
+		next_re = rb_entry(next, struct rb_entry, rb_node);
+
+		if (cur_re->ofs + cur_re->len > next_re->ofs) {
+			f2fs_msg(sbi->sb, KERN_INFO, "inconsistent rbtree, "
+				"cur(%u, %u) next(%u, %u)",
+				cur_re->ofs, cur_re->len,
+				next_re->ofs, next_re->len);
+			return false;
+		}
+
+		cur = next;
+	}
+#endif
+	return true;
+}
+
+static struct kmem_cache *extent_tree_slab;
+static struct kmem_cache *extent_node_slab;
+
+static struct extent_node *__attach_extent_node(struct f2fs_sb_info *sbi,
+				struct extent_tree *et, struct extent_info *ei,
+				struct rb_node *parent, struct rb_node **p)
+{
+	struct extent_node *en;
+
+	en = kmem_cache_alloc(extent_node_slab, GFP_ATOMIC);
+	if (!en)
+		return NULL;
+
+	en->ei = *ei;
+	INIT_LIST_HEAD(&en->list);
+	en->et = et;
+
+	rb_link_node(&en->rb_node, parent, p);
+	rb_insert_color(&en->rb_node, &et->root);
+	atomic_inc(&et->node_cnt);
+	atomic_inc(&sbi->total_ext_node);
+	return en;
+}
+
+static void __detach_extent_node(struct f2fs_sb_info *sbi,
+				struct extent_tree *et, struct extent_node *en)
+{
+	rb_erase(&en->rb_node, &et->root);
+	atomic_dec(&et->node_cnt);
+	atomic_dec(&sbi->total_ext_node);
+
+	if (et->cached_en == en)
+		et->cached_en = NULL;
+	kmem_cache_free(extent_node_slab, en);
+}
+
+/*
+ * Flow to release an extent_node:
+ * 1. list_del_init
+ * 2. __detach_extent_node
+ * 3. kmem_cache_free.
+ */
+static void __release_extent_node(struct f2fs_sb_info *sbi,
+			struct extent_tree *et, struct extent_node *en)
+{
+	spin_lock(&sbi->extent_lock);
+	f2fs_bug_on(sbi, list_empty(&en->list));
+	list_del_init(&en->list);
+	spin_unlock(&sbi->extent_lock);
+
+	__detach_extent_node(sbi, et, en);
+}
+
+static struct extent_tree *__grab_extent_tree(struct inode *inode)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct extent_tree *et;
+	nid_t ino = inode->i_ino;
+
+	mutex_lock(&sbi->extent_tree_lock);
+	et = radix_tree_lookup(&sbi->extent_tree_root, ino);
+	if (!et) {
+		et = f2fs_kmem_cache_alloc(extent_tree_slab, GFP_NOFS);
+		f2fs_radix_tree_insert(&sbi->extent_tree_root, ino, et);
+		memset(et, 0, sizeof(struct extent_tree));
+		et->ino = ino;
+		et->root = RB_ROOT;
+		et->cached_en = NULL;
+		rwlock_init(&et->lock);
+		INIT_LIST_HEAD(&et->list);
+		atomic_set(&et->node_cnt, 0);
+		atomic_inc(&sbi->total_ext_tree);
+	} else {
+		atomic_dec(&sbi->total_zombie_tree);
+		list_del_init(&et->list);
+	}
+	mutex_unlock(&sbi->extent_tree_lock);
+
+	/* never died until evict_inode */
+	F2FS_I(inode)->extent_tree = et;
+
+	return et;
+}
+
+static struct extent_node *__init_extent_tree(struct f2fs_sb_info *sbi,
+				struct extent_tree *et, struct extent_info *ei)
+{
+	struct rb_node **p = &et->root.rb_node;
+	struct extent_node *en;
+
+	en = __attach_extent_node(sbi, et, ei, NULL, p);
+	if (!en)
+		return NULL;
+
+	et->largest = en->ei;
+	et->cached_en = en;
+	return en;
+}
+
+static unsigned int __free_extent_tree(struct f2fs_sb_info *sbi,
+					struct extent_tree *et)
+{
+	struct rb_node *node, *next;
+	struct extent_node *en;
+	unsigned int count = atomic_read(&et->node_cnt);
+
+	node = rb_first(&et->root);
+	while (node) {
+		next = rb_next(node);
+		en = rb_entry(node, struct extent_node, rb_node);
+		__release_extent_node(sbi, et, en);
+		node = next;
+	}
+
+	return count - atomic_read(&et->node_cnt);
+}
+
+static void __drop_largest_extent(struct inode *inode,
+					pgoff_t fofs, unsigned int len)
+{
+	struct extent_info *largest = &F2FS_I(inode)->extent_tree->largest;
+
+	if (fofs < largest->fofs + largest->len && fofs + len > largest->fofs) {
+		largest->len = 0;
+		f2fs_mark_inode_dirty_sync(inode, true);
+	}
+}
+
+/* return true, if inode page is changed */
+static bool __f2fs_init_extent_tree(struct inode *inode, struct f2fs_extent *i_ext)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct extent_tree *et;
+	struct extent_node *en;
+	struct extent_info ei;
+
+	if (!f2fs_may_extent_tree(inode)) {
+		/* drop largest extent */
+		if (i_ext && i_ext->len) {
+			i_ext->len = 0;
+			return true;
+		}
+		return false;
+	}
+
+	et = __grab_extent_tree(inode);
+
+	if (!i_ext || !i_ext->len)
+		return false;
+
+	get_extent_info(&ei, i_ext);
+
+	write_lock(&et->lock);
+	if (atomic_read(&et->node_cnt))
+		goto out;
+
+	en = __init_extent_tree(sbi, et, &ei);
+	if (en) {
+		spin_lock(&sbi->extent_lock);
+		list_add_tail(&en->list, &sbi->extent_list);
+		spin_unlock(&sbi->extent_lock);
+	}
+out:
+	write_unlock(&et->lock);
+	return false;
+}
+
+bool f2fs_init_extent_tree(struct inode *inode, struct f2fs_extent *i_ext)
+{
+	bool ret =  __f2fs_init_extent_tree(inode, i_ext);
+
+	if (!F2FS_I(inode)->extent_tree)
+		set_inode_flag(inode, FI_NO_EXTENT);
+
+	return ret;
+}
+
+static bool f2fs_lookup_extent_tree(struct inode *inode, pgoff_t pgofs,
+							struct extent_info *ei)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct extent_tree *et = F2FS_I(inode)->extent_tree;
+	struct extent_node *en;
+	bool ret = false;
+
+	f2fs_bug_on(sbi, !et);
+
+	trace_f2fs_lookup_extent_tree_start(inode, pgofs);
+
+	read_lock(&et->lock);
+
+	if (et->largest.fofs <= pgofs &&
+			et->largest.fofs + et->largest.len > pgofs) {
+		*ei = et->largest;
+		ret = true;
+		stat_inc_largest_node_hit(sbi);
+		goto out;
+	}
+
+	en = (struct extent_node *)__lookup_rb_tree(&et->root,
+				(struct rb_entry *)et->cached_en, pgofs);
+	if (!en)
+		goto out;
+
+	if (en == et->cached_en)
+		stat_inc_cached_node_hit(sbi);
+	else
+		stat_inc_rbtree_node_hit(sbi);
+
+	*ei = en->ei;
+	spin_lock(&sbi->extent_lock);
+	if (!list_empty(&en->list)) {
+		list_move_tail(&en->list, &sbi->extent_list);
+		et->cached_en = en;
+	}
+	spin_unlock(&sbi->extent_lock);
+	ret = true;
+out:
+	stat_inc_total_hit(sbi);
+	read_unlock(&et->lock);
+
+	trace_f2fs_lookup_extent_tree_end(inode, pgofs, ei);
+	return ret;
+}
+
+static struct extent_node *__try_merge_extent_node(struct inode *inode,
+				struct extent_tree *et, struct extent_info *ei,
+				struct extent_node *prev_ex,
+				struct extent_node *next_ex)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct extent_node *en = NULL;
+
+	if (prev_ex && __is_back_mergeable(ei, &prev_ex->ei)) {
+		prev_ex->ei.len += ei->len;
+		ei = &prev_ex->ei;
+		en = prev_ex;
+	}
+
+	if (next_ex && __is_front_mergeable(ei, &next_ex->ei)) {
+		next_ex->ei.fofs = ei->fofs;
+		next_ex->ei.blk = ei->blk;
+		next_ex->ei.len += ei->len;
+		if (en)
+			__release_extent_node(sbi, et, prev_ex);
+
+		en = next_ex;
+	}
+
+	if (!en)
+		return NULL;
+
+	__try_update_largest_extent(inode, et, en);
+
+	spin_lock(&sbi->extent_lock);
+	if (!list_empty(&en->list)) {
+		list_move_tail(&en->list, &sbi->extent_list);
+		et->cached_en = en;
+	}
+	spin_unlock(&sbi->extent_lock);
+	return en;
+}
+
+static struct extent_node *__insert_extent_tree(struct inode *inode,
+				struct extent_tree *et, struct extent_info *ei,
+				struct rb_node **insert_p,
+				struct rb_node *insert_parent)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct rb_node **p;
+	struct rb_node *parent = NULL;
+	struct extent_node *en = NULL;
+
+	if (insert_p && insert_parent) {
+		parent = insert_parent;
+		p = insert_p;
+		goto do_insert;
+	}
+
+	p = __lookup_rb_tree_for_insert(sbi, &et->root, &parent, ei->fofs);
+do_insert:
+	en = __attach_extent_node(sbi, et, ei, parent, p);
+	if (!en)
+		return NULL;
+
+	__try_update_largest_extent(inode, et, en);
+
+	/* update in global extent list */
+	spin_lock(&sbi->extent_lock);
+	list_add_tail(&en->list, &sbi->extent_list);
+	et->cached_en = en;
+	spin_unlock(&sbi->extent_lock);
+	return en;
+}
+
+static void f2fs_update_extent_tree_range(struct inode *inode,
+				pgoff_t fofs, block_t blkaddr, unsigned int len)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct extent_tree *et = F2FS_I(inode)->extent_tree;
+	struct extent_node *en = NULL, *en1 = NULL;
+	struct extent_node *prev_en = NULL, *next_en = NULL;
+	struct extent_info ei, dei, prev;
+	struct rb_node **insert_p = NULL, *insert_parent = NULL;
+	unsigned int end = fofs + len;
+	unsigned int pos = (unsigned int)fofs;
+
+	if (!et)
+		return;
+
+	trace_f2fs_update_extent_tree_range(inode, fofs, blkaddr, len);
+
+	write_lock(&et->lock);
+
+	if (is_inode_flag_set(inode, FI_NO_EXTENT)) {
+		write_unlock(&et->lock);
+		return;
+	}
+
+	prev = et->largest;
+	dei.len = 0;
+
+	/*
+	 * drop largest extent before lookup, in case it's already
+	 * been shrunk from extent tree
+	 */
+	__drop_largest_extent(inode, fofs, len);
+
+	/* 1. lookup first extent node in range [fofs, fofs + len - 1] */
+	en = (struct extent_node *)__lookup_rb_tree_ret(&et->root,
+					(struct rb_entry *)et->cached_en, fofs,
+					(struct rb_entry **)&prev_en,
+					(struct rb_entry **)&next_en,
+					&insert_p, &insert_parent, false);
+	if (!en)
+		en = next_en;
+
+	/* 2. invlidate all extent nodes in range [fofs, fofs + len - 1] */
+	while (en && en->ei.fofs < end) {
+		unsigned int org_end;
+		int parts = 0;	/* # of parts current extent split into */
+
+		next_en = en1 = NULL;
+
+		dei = en->ei;
+		org_end = dei.fofs + dei.len;
+		f2fs_bug_on(sbi, pos >= org_end);
+
+		if (pos > dei.fofs &&	pos - dei.fofs >= F2FS_MIN_EXTENT_LEN) {
+			en->ei.len = pos - en->ei.fofs;
+			prev_en = en;
+			parts = 1;
+		}
+
+		if (end < org_end && org_end - end >= F2FS_MIN_EXTENT_LEN) {
+			if (parts) {
+				set_extent_info(&ei, end,
+						end - dei.fofs + dei.blk,
+						org_end - end);
+				en1 = __insert_extent_tree(inode, et, &ei,
+							NULL, NULL);
+				next_en = en1;
+			} else {
+				en->ei.fofs = end;
+				en->ei.blk += end - dei.fofs;
+				en->ei.len -= end - dei.fofs;
+				next_en = en;
+			}
+			parts++;
+		}
+
+		if (!next_en) {
+			struct rb_node *node = rb_next(&en->rb_node);
+
+			next_en = rb_entry_safe(node, struct extent_node,
+						rb_node);
+		}
+
+		if (parts)
+			__try_update_largest_extent(inode, et, en);
+		else
+			__release_extent_node(sbi, et, en);
+
+		/*
+		 * if original extent is split into zero or two parts, extent
+		 * tree has been altered by deletion or insertion, therefore
+		 * invalidate pointers regard to tree.
+		 */
+		if (parts != 1) {
+			insert_p = NULL;
+			insert_parent = NULL;
+		}
+		en = next_en;
+	}
+
+	/* 3. update extent in extent cache */
+	if (blkaddr) {
+
+		set_extent_info(&ei, fofs, blkaddr, len);
+		if (!__try_merge_extent_node(inode, et, &ei, prev_en, next_en))
+			__insert_extent_tree(inode, et, &ei,
+						insert_p, insert_parent);
+
+		/* give up extent_cache, if split and small updates happen */
+		if (dei.len >= 1 &&
+				prev.len < F2FS_MIN_EXTENT_LEN &&
+				et->largest.len < F2FS_MIN_EXTENT_LEN) {
+			__drop_largest_extent(inode, 0, UINT_MAX);
+			set_inode_flag(inode, FI_NO_EXTENT);
+		}
+	}
+
+	if (is_inode_flag_set(inode, FI_NO_EXTENT))
+		__free_extent_tree(sbi, et);
+
+	write_unlock(&et->lock);
+}
+
+unsigned int f2fs_shrink_extent_tree(struct f2fs_sb_info *sbi, int nr_shrink)
+{
+	struct extent_tree *et, *next;
+	struct extent_node *en;
+	unsigned int node_cnt = 0, tree_cnt = 0;
+	int remained;
+
+	if (!test_opt(sbi, EXTENT_CACHE))
+		return 0;
+
+	if (!atomic_read(&sbi->total_zombie_tree))
+		goto free_node;
+
+	if (!mutex_trylock(&sbi->extent_tree_lock))
+		goto out;
+
+	/* 1. remove unreferenced extent tree */
+	list_for_each_entry_safe(et, next, &sbi->zombie_list, list) {
+		if (atomic_read(&et->node_cnt)) {
+			write_lock(&et->lock);
+			node_cnt += __free_extent_tree(sbi, et);
+			write_unlock(&et->lock);
+		}
+		f2fs_bug_on(sbi, atomic_read(&et->node_cnt));
+		list_del_init(&et->list);
+		radix_tree_delete(&sbi->extent_tree_root, et->ino);
+		kmem_cache_free(extent_tree_slab, et);
+		atomic_dec(&sbi->total_ext_tree);
+		atomic_dec(&sbi->total_zombie_tree);
+		tree_cnt++;
+
+		if (node_cnt + tree_cnt >= nr_shrink)
+			goto unlock_out;
+		cond_resched();
+	}
+	mutex_unlock(&sbi->extent_tree_lock);
+
+free_node:
+	/* 2. remove LRU extent entries */
+	if (!mutex_trylock(&sbi->extent_tree_lock))
+		goto out;
+
+	remained = nr_shrink - (node_cnt + tree_cnt);
+
+	spin_lock(&sbi->extent_lock);
+	for (; remained > 0; remained--) {
+		if (list_empty(&sbi->extent_list))
+			break;
+		en = list_first_entry(&sbi->extent_list,
+					struct extent_node, list);
+		et = en->et;
+		if (!write_trylock(&et->lock)) {
+			/* refresh this extent node's position in extent list */
+			list_move_tail(&en->list, &sbi->extent_list);
+			continue;
+		}
+
+		list_del_init(&en->list);
+		spin_unlock(&sbi->extent_lock);
+
+		__detach_extent_node(sbi, et, en);
+
+		write_unlock(&et->lock);
+		node_cnt++;
+		spin_lock(&sbi->extent_lock);
+	}
+	spin_unlock(&sbi->extent_lock);
+
+unlock_out:
+	mutex_unlock(&sbi->extent_tree_lock);
+out:
+	trace_f2fs_shrink_extent_tree(sbi, node_cnt, tree_cnt);
+
+	return node_cnt + tree_cnt;
+}
+
+unsigned int f2fs_destroy_extent_node(struct inode *inode)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct extent_tree *et = F2FS_I(inode)->extent_tree;
+	unsigned int node_cnt = 0;
+
+	if (!et || !atomic_read(&et->node_cnt))
+		return 0;
+
+	write_lock(&et->lock);
+	node_cnt = __free_extent_tree(sbi, et);
+	write_unlock(&et->lock);
+
+	return node_cnt;
+}
+
+void f2fs_drop_extent_tree(struct inode *inode)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct extent_tree *et = F2FS_I(inode)->extent_tree;
+
+	if (!f2fs_may_extent_tree(inode))
+		return;
+
+	set_inode_flag(inode, FI_NO_EXTENT);
+
+	write_lock(&et->lock);
+	__free_extent_tree(sbi, et);
+	__drop_largest_extent(inode, 0, UINT_MAX);
+	write_unlock(&et->lock);
+}
+
+void f2fs_destroy_extent_tree(struct inode *inode)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct extent_tree *et = F2FS_I(inode)->extent_tree;
+	unsigned int node_cnt = 0;
+
+	if (!et)
+		return;
+
+	if (inode->i_nlink && !is_bad_inode(inode) &&
+					atomic_read(&et->node_cnt)) {
+		mutex_lock(&sbi->extent_tree_lock);
+		list_add_tail(&et->list, &sbi->zombie_list);
+		atomic_inc(&sbi->total_zombie_tree);
+		mutex_unlock(&sbi->extent_tree_lock);
+		return;
+	}
+
+	/* free all extent info belong to this extent tree */
+	node_cnt = f2fs_destroy_extent_node(inode);
+
+	/* delete extent tree entry in radix tree */
+	mutex_lock(&sbi->extent_tree_lock);
+	f2fs_bug_on(sbi, atomic_read(&et->node_cnt));
+	radix_tree_delete(&sbi->extent_tree_root, inode->i_ino);
+	kmem_cache_free(extent_tree_slab, et);
+	atomic_dec(&sbi->total_ext_tree);
+	mutex_unlock(&sbi->extent_tree_lock);
+
+	F2FS_I(inode)->extent_tree = NULL;
+
+	trace_f2fs_destroy_extent_tree(inode, node_cnt);
+}
+
+bool f2fs_lookup_extent_cache(struct inode *inode, pgoff_t pgofs,
+					struct extent_info *ei)
+{
+	if (!f2fs_may_extent_tree(inode))
+		return false;
+
+	return f2fs_lookup_extent_tree(inode, pgofs, ei);
+}
+
+void f2fs_update_extent_cache(struct dnode_of_data *dn)
+{
+	pgoff_t fofs;
+	block_t blkaddr;
+
+	if (!f2fs_may_extent_tree(dn->inode))
+		return;
+
+	if (dn->data_blkaddr == NEW_ADDR)
+		blkaddr = NULL_ADDR;
+	else
+		blkaddr = dn->data_blkaddr;
+
+	fofs = start_bidx_of_node(ofs_of_node(dn->node_page), dn->inode) +
+								dn->ofs_in_node;
+	f2fs_update_extent_tree_range(dn->inode, fofs, blkaddr, 1);
+}
+
+void f2fs_update_extent_cache_range(struct dnode_of_data *dn,
+				pgoff_t fofs, block_t blkaddr, unsigned int len)
+
+{
+	if (!f2fs_may_extent_tree(dn->inode))
+		return;
+
+	f2fs_update_extent_tree_range(dn->inode, fofs, blkaddr, len);
+}
+
+void init_extent_cache_info(struct f2fs_sb_info *sbi)
+{
+	INIT_RADIX_TREE(&sbi->extent_tree_root, GFP_NOIO);
+	mutex_init(&sbi->extent_tree_lock);
+	INIT_LIST_HEAD(&sbi->extent_list);
+	spin_lock_init(&sbi->extent_lock);
+	atomic_set(&sbi->total_ext_tree, 0);
+	INIT_LIST_HEAD(&sbi->zombie_list);
+	atomic_set(&sbi->total_zombie_tree, 0);
+	atomic_set(&sbi->total_ext_node, 0);
+}
+
+int __init create_extent_cache(void)
+{
+	extent_tree_slab = f2fs_kmem_cache_create("f2fs_extent_tree",
+			sizeof(struct extent_tree));
+	if (!extent_tree_slab)
+		return -ENOMEM;
+	extent_node_slab = f2fs_kmem_cache_create("f2fs_extent_node",
+			sizeof(struct extent_node));
+	if (!extent_node_slab) {
+		kmem_cache_destroy(extent_tree_slab);
+		return -ENOMEM;
+	}
+	return 0;
+}
+
+void destroy_extent_cache(void)
+{
+	kmem_cache_destroy(extent_node_slab);
+	kmem_cache_destroy(extent_tree_slab);
+}
diff --git a/src/kernel/linux/v4.14/fs/f2fs/f2fs.h b/src/kernel/linux/v4.14/fs/f2fs/f2fs.h
new file mode 100644
index 0000000..3d5abc6
--- /dev/null
+++ b/src/kernel/linux/v4.14/fs/f2fs/f2fs.h
@@ -0,0 +1,3360 @@
+/*
+ * fs/f2fs/f2fs.h
+ *
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ *             http://www.samsung.com/
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#ifndef _LINUX_F2FS_H
+#define _LINUX_F2FS_H
+
+#include <linux/types.h>
+#include <linux/page-flags.h>
+#include <linux/buffer_head.h>
+#include <linux/slab.h>
+#include <linux/crc32.h>
+#include <linux/magic.h>
+#include <linux/kobject.h>
+#include <linux/sched.h>
+#include <linux/cred.h>
+#include <linux/vmalloc.h>
+#include <linux/bio.h>
+#include <linux/blkdev.h>
+#include <linux/quotaops.h>
+#include <crypto/hash.h>
+
+#define __FS_HAS_ENCRYPTION IS_ENABLED(CONFIG_F2FS_FS_ENCRYPTION)
+#include <linux/fscrypt.h>
+
+#ifdef CONFIG_F2FS_CHECK_FS
+#define f2fs_bug_on(sbi, condition)	BUG_ON(condition)
+#else
+#define f2fs_bug_on(sbi, condition)					\
+	do {								\
+		if (unlikely(condition)) {				\
+			WARN_ON(1);					\
+			set_sbi_flag(sbi, SBI_NEED_FSCK);		\
+		}							\
+	} while (0)
+#endif
+
+#ifdef CONFIG_F2FS_FAULT_INJECTION
+enum {
+	FAULT_KMALLOC,
+	FAULT_KVMALLOC,
+	FAULT_PAGE_ALLOC,
+	FAULT_PAGE_GET,
+	FAULT_ALLOC_BIO,
+	FAULT_ALLOC_NID,
+	FAULT_ORPHAN,
+	FAULT_BLOCK,
+	FAULT_DIR_DEPTH,
+	FAULT_EVICT_INODE,
+	FAULT_TRUNCATE,
+	FAULT_IO,
+	FAULT_CHECKPOINT,
+	FAULT_MAX,
+};
+
+struct f2fs_fault_info {
+	atomic_t inject_ops;
+	unsigned int inject_rate;
+	unsigned int inject_type;
+};
+
+extern char *fault_name[FAULT_MAX];
+#define IS_FAULT_SET(fi, type) ((fi)->inject_type & (1 << (type)))
+#endif
+
+/*
+ * For mount options
+ */
+#define F2FS_MOUNT_BG_GC		0x00000001
+#define F2FS_MOUNT_DISABLE_ROLL_FORWARD	0x00000002
+#define F2FS_MOUNT_DISCARD		0x00000004
+#define F2FS_MOUNT_NOHEAP		0x00000008
+#define F2FS_MOUNT_XATTR_USER		0x00000010
+#define F2FS_MOUNT_POSIX_ACL		0x00000020
+#define F2FS_MOUNT_DISABLE_EXT_IDENTIFY	0x00000040
+#define F2FS_MOUNT_INLINE_XATTR		0x00000080
+#define F2FS_MOUNT_INLINE_DATA		0x00000100
+#define F2FS_MOUNT_INLINE_DENTRY	0x00000200
+#define F2FS_MOUNT_FLUSH_MERGE		0x00000400
+#define F2FS_MOUNT_NOBARRIER		0x00000800
+#define F2FS_MOUNT_FASTBOOT		0x00001000
+#define F2FS_MOUNT_EXTENT_CACHE		0x00002000
+#define F2FS_MOUNT_FORCE_FG_GC		0x00004000
+#define F2FS_MOUNT_DATA_FLUSH		0x00008000
+#define F2FS_MOUNT_FAULT_INJECTION	0x00010000
+#define F2FS_MOUNT_ADAPTIVE		0x00020000
+#define F2FS_MOUNT_LFS			0x00040000
+#define F2FS_MOUNT_USRQUOTA		0x00080000
+#define F2FS_MOUNT_GRPQUOTA		0x00100000
+#define F2FS_MOUNT_PRJQUOTA		0x00200000
+#define F2FS_MOUNT_QUOTA		0x00400000
+#define F2FS_MOUNT_INLINE_XATTR_SIZE	0x00800000
+#define F2FS_MOUNT_RESERVE_ROOT		0x01000000
+
+#define F2FS_OPTION(sbi)	((sbi)->mount_opt)
+#define clear_opt(sbi, option)	(F2FS_OPTION(sbi).opt &= ~F2FS_MOUNT_##option)
+#define set_opt(sbi, option)	(F2FS_OPTION(sbi).opt |= F2FS_MOUNT_##option)
+#define test_opt(sbi, option)	(F2FS_OPTION(sbi).opt & F2FS_MOUNT_##option)
+
+#define ver_after(a, b)	(typecheck(unsigned long long, a) &&		\
+		typecheck(unsigned long long, b) &&			\
+		((long long)((a) - (b)) > 0))
+
+typedef u32 block_t;	/*
+			 * should not change u32, since it is the on-disk block
+			 * address format, __le32.
+			 */
+typedef u32 nid_t;
+
+struct f2fs_mount_info {
+	unsigned int opt;
+	int write_io_size_bits;		/* Write IO size bits */
+	block_t root_reserved_blocks;	/* root reserved blocks */
+	kuid_t s_resuid;		/* reserved blocks for uid */
+	kgid_t s_resgid;		/* reserved blocks for gid */
+	int active_logs;		/* # of active logs */
+	int inline_xattr_size;		/* inline xattr size */
+#ifdef CONFIG_F2FS_FAULT_INJECTION
+	struct f2fs_fault_info fault_info;	/* For fault injection */
+#endif
+#ifdef CONFIG_QUOTA
+	/* Names of quota files with journalled quota */
+	char *s_qf_names[MAXQUOTAS];
+	int s_jquota_fmt;			/* Format of quota to use */
+#endif
+	/* For which write hints are passed down to block layer */
+	int whint_mode;
+	int alloc_mode;			/* segment allocation policy */
+	int fsync_mode;			/* fsync policy */
+	bool test_dummy_encryption;	/* test dummy encryption */
+};
+
+#define F2FS_FEATURE_ENCRYPT		0x0001
+#define F2FS_FEATURE_BLKZONED		0x0002
+#define F2FS_FEATURE_ATOMIC_WRITE	0x0004
+#define F2FS_FEATURE_EXTRA_ATTR		0x0008
+#define F2FS_FEATURE_PRJQUOTA		0x0010
+#define F2FS_FEATURE_INODE_CHKSUM	0x0020
+#define F2FS_FEATURE_FLEXIBLE_INLINE_XATTR	0x0040
+#define F2FS_FEATURE_QUOTA_INO		0x0080
+#define F2FS_FEATURE_INODE_CRTIME	0x0100
+#define F2FS_FEATURE_LOST_FOUND		0x0200
+#define F2FS_FEATURE_VERITY		0x0400	/* reserved */
+
+#define F2FS_HAS_FEATURE(sb, mask)					\
+	((F2FS_SB(sb)->raw_super->feature & cpu_to_le32(mask)) != 0)
+#define F2FS_SET_FEATURE(sb, mask)					\
+	(F2FS_SB(sb)->raw_super->feature |= cpu_to_le32(mask))
+#define F2FS_CLEAR_FEATURE(sb, mask)					\
+	(F2FS_SB(sb)->raw_super->feature &= ~cpu_to_le32(mask))
+
+/*
+ * Default values for user and/or group using reserved blocks
+ */
+#define	F2FS_DEF_RESUID		0
+#define	F2FS_DEF_RESGID		0
+
+/*
+ * For checkpoint manager
+ */
+enum {
+	NAT_BITMAP,
+	SIT_BITMAP
+};
+
+#define	CP_UMOUNT	0x00000001
+#define	CP_FASTBOOT	0x00000002
+#define	CP_SYNC		0x00000004
+#define	CP_RECOVERY	0x00000008
+#define	CP_DISCARD	0x00000010
+#define CP_TRIMMED	0x00000020
+
+#define MAX_DISCARD_BLOCKS(sbi)		BLKS_PER_SEC(sbi)
+#define DEF_MAX_DISCARD_REQUEST		8	/* issue 8 discards per round */
+#define DEF_MAX_DISCARD_LEN		512	/* Max. 2MB per discard */
+#define DEF_MIN_DISCARD_ISSUE_TIME	50	/* 50 ms, if exists */
+#define DEF_MAX_DISCARD_ISSUE_TIME	60000	/* 60 s, if no candidates */
+#define DEF_DISCARD_URGENT_UTIL		80	/* do more discard over 80% */
+#define DEF_CP_INTERVAL			60	/* 60 secs */
+#define DEF_IDLE_INTERVAL		5	/* 5 secs */
+
+struct cp_control {
+	int reason;
+	__u64 trim_start;
+	__u64 trim_end;
+	__u64 trim_minlen;
+};
+
+/*
+ * indicate meta/data type
+ */
+enum {
+	META_CP,
+	META_NAT,
+	META_SIT,
+	META_SSA,
+	META_POR,
+	DATA_GENERIC,
+	META_GENERIC,
+};
+
+/* for the list of ino */
+enum {
+	ORPHAN_INO,		/* for orphan ino list */
+	APPEND_INO,		/* for append ino list */
+	UPDATE_INO,		/* for update ino list */
+	TRANS_DIR_INO,		/* for trasactions dir ino list */
+	FLUSH_INO,		/* for multiple device flushing */
+	MAX_INO_ENTRY,		/* max. list */
+};
+
+struct ino_entry {
+	struct list_head list;		/* list head */
+	nid_t ino;			/* inode number */
+	unsigned int dirty_device;	/* dirty device bitmap */
+};
+
+/* for the list of inodes to be GCed */
+struct inode_entry {
+	struct list_head list;	/* list head */
+	struct inode *inode;	/* vfs inode pointer */
+};
+
+/* for the bitmap indicate blocks to be discarded */
+struct discard_entry {
+	struct list_head list;	/* list head */
+	block_t start_blkaddr;	/* start blockaddr of current segment */
+	unsigned char discard_map[SIT_VBLOCK_MAP_SIZE];	/* segment discard bitmap */
+};
+
+/* default discard granularity of inner discard thread, unit: block count */
+#define DEFAULT_DISCARD_GRANULARITY		16
+
+/* max discard pend list number */
+#define MAX_PLIST_NUM		512
+#define plist_idx(blk_num)	((blk_num) >= MAX_PLIST_NUM ?		\
+					(MAX_PLIST_NUM - 1) : (blk_num - 1))
+
+enum {
+	D_PREP,
+	D_SUBMIT,
+	D_DONE,
+};
+
+struct discard_info {
+	block_t lstart;			/* logical start address */
+	block_t len;			/* length */
+	block_t start;			/* actual start address in dev */
+};
+
+struct discard_cmd {
+	struct rb_node rb_node;		/* rb node located in rb-tree */
+	union {
+		struct {
+			block_t lstart;	/* logical start address */
+			block_t len;	/* length */
+			block_t start;	/* actual start address in dev */
+		};
+		struct discard_info di;	/* discard info */
+
+	};
+	struct list_head list;		/* command list */
+	struct completion wait;		/* compleation */
+	struct block_device *bdev;	/* bdev */
+	unsigned short ref;		/* reference count */
+	unsigned char state;		/* state */
+	int error;			/* bio error */
+};
+
+enum {
+	DPOLICY_BG,
+	DPOLICY_FORCE,
+	DPOLICY_FSTRIM,
+	DPOLICY_UMOUNT,
+	MAX_DPOLICY,
+};
+
+struct discard_policy {
+	int type;			/* type of discard */
+	unsigned int min_interval;	/* used for candidates exist */
+	unsigned int max_interval;	/* used for candidates not exist */
+	unsigned int max_requests;	/* # of discards issued per round */
+	unsigned int io_aware_gran;	/* minimum granularity discard not be aware of I/O */
+	bool io_aware;			/* issue discard in idle time */
+	bool sync;			/* submit discard with REQ_SYNC flag */
+	unsigned int granularity;	/* discard granularity */
+};
+
+struct discard_cmd_control {
+	struct task_struct *f2fs_issue_discard;	/* discard thread */
+	struct list_head entry_list;		/* 4KB discard entry list */
+	struct list_head pend_list[MAX_PLIST_NUM];/* store pending entries */
+	struct list_head wait_list;		/* store on-flushing entries */
+	struct list_head fstrim_list;		/* in-flight discard from fstrim */
+	wait_queue_head_t discard_wait_queue;	/* waiting queue for wake-up */
+	unsigned int discard_wake;		/* to wake up discard thread */
+	struct mutex cmd_lock;
+	unsigned int nr_discards;		/* # of discards in the list */
+	unsigned int max_discards;		/* max. discards to be issued */
+	unsigned int discard_granularity;	/* discard granularity */
+	unsigned int undiscard_blks;		/* # of undiscard blocks */
+	atomic_t issued_discard;		/* # of issued discard */
+	atomic_t issing_discard;		/* # of issing discard */
+	atomic_t discard_cmd_cnt;		/* # of cached cmd count */
+	struct rb_root root;			/* root of discard rb-tree */
+};
+
+/* for the list of fsync inodes, used only during recovery */
+struct fsync_inode_entry {
+	struct list_head list;	/* list head */
+	struct inode *inode;	/* vfs inode pointer */
+	block_t blkaddr;	/* block address locating the last fsync */
+	block_t last_dentry;	/* block address locating the last dentry */
+};
+
+#define nats_in_cursum(jnl)		(le16_to_cpu((jnl)->n_nats))
+#define sits_in_cursum(jnl)		(le16_to_cpu((jnl)->n_sits))
+
+#define nat_in_journal(jnl, i)		((jnl)->nat_j.entries[i].ne)
+#define nid_in_journal(jnl, i)		((jnl)->nat_j.entries[i].nid)
+#define sit_in_journal(jnl, i)		((jnl)->sit_j.entries[i].se)
+#define segno_in_journal(jnl, i)	((jnl)->sit_j.entries[i].segno)
+
+#define MAX_NAT_JENTRIES(jnl)	(NAT_JOURNAL_ENTRIES - nats_in_cursum(jnl))
+#define MAX_SIT_JENTRIES(jnl)	(SIT_JOURNAL_ENTRIES - sits_in_cursum(jnl))
+
+static inline int update_nats_in_cursum(struct f2fs_journal *journal, int i)
+{
+	int before = nats_in_cursum(journal);
+
+	journal->n_nats = cpu_to_le16(before + i);
+	return before;
+}
+
+static inline int update_sits_in_cursum(struct f2fs_journal *journal, int i)
+{
+	int before = sits_in_cursum(journal);
+
+	journal->n_sits = cpu_to_le16(before + i);
+	return before;
+}
+
+static inline bool __has_cursum_space(struct f2fs_journal *journal,
+							int size, int type)
+{
+	if (type == NAT_JOURNAL)
+		return size <= MAX_NAT_JENTRIES(journal);
+	return size <= MAX_SIT_JENTRIES(journal);
+}
+
+/*
+ * ioctl commands
+ */
+#define F2FS_IOC_GETFLAGS		FS_IOC_GETFLAGS
+#define F2FS_IOC_SETFLAGS		FS_IOC_SETFLAGS
+#define F2FS_IOC_GETVERSION		FS_IOC_GETVERSION
+
+#define F2FS_IOCTL_MAGIC		0xf5
+#define F2FS_IOC_START_ATOMIC_WRITE	_IO(F2FS_IOCTL_MAGIC, 1)
+#define F2FS_IOC_COMMIT_ATOMIC_WRITE	_IO(F2FS_IOCTL_MAGIC, 2)
+#define F2FS_IOC_START_VOLATILE_WRITE	_IO(F2FS_IOCTL_MAGIC, 3)
+#define F2FS_IOC_RELEASE_VOLATILE_WRITE	_IO(F2FS_IOCTL_MAGIC, 4)
+#define F2FS_IOC_ABORT_VOLATILE_WRITE	_IO(F2FS_IOCTL_MAGIC, 5)
+#define F2FS_IOC_GARBAGE_COLLECT	_IOW(F2FS_IOCTL_MAGIC, 6, __u32)
+#define F2FS_IOC_WRITE_CHECKPOINT	_IO(F2FS_IOCTL_MAGIC, 7)
+#define F2FS_IOC_DEFRAGMENT		_IOWR(F2FS_IOCTL_MAGIC, 8,	\
+						struct f2fs_defragment)
+#define F2FS_IOC_MOVE_RANGE		_IOWR(F2FS_IOCTL_MAGIC, 9,	\
+						struct f2fs_move_range)
+#define F2FS_IOC_FLUSH_DEVICE		_IOW(F2FS_IOCTL_MAGIC, 10,	\
+						struct f2fs_flush_device)
+#define F2FS_IOC_GARBAGE_COLLECT_RANGE	_IOW(F2FS_IOCTL_MAGIC, 11,	\
+						struct f2fs_gc_range)
+#define F2FS_IOC_GET_FEATURES		_IOR(F2FS_IOCTL_MAGIC, 12, __u32)
+#define F2FS_IOC_SET_PIN_FILE		_IOW(F2FS_IOCTL_MAGIC, 13, __u32)
+#define F2FS_IOC_GET_PIN_FILE		_IOR(F2FS_IOCTL_MAGIC, 14, __u32)
+#define F2FS_IOC_PRECACHE_EXTENTS	_IO(F2FS_IOCTL_MAGIC, 15)
+
+#define F2FS_IOC_SET_ENCRYPTION_POLICY	FS_IOC_SET_ENCRYPTION_POLICY
+#define F2FS_IOC_GET_ENCRYPTION_POLICY	FS_IOC_GET_ENCRYPTION_POLICY
+#define F2FS_IOC_GET_ENCRYPTION_PWSALT	FS_IOC_GET_ENCRYPTION_PWSALT
+
+/*
+ * should be same as XFS_IOC_GOINGDOWN.
+ * Flags for going down operation used by FS_IOC_GOINGDOWN
+ */
+#define F2FS_IOC_SHUTDOWN	_IOR('X', 125, __u32)	/* Shutdown */
+#define F2FS_GOING_DOWN_FULLSYNC	0x0	/* going down with full sync */
+#define F2FS_GOING_DOWN_METASYNC	0x1	/* going down with metadata */
+#define F2FS_GOING_DOWN_NOSYNC		0x2	/* going down */
+#define F2FS_GOING_DOWN_METAFLUSH	0x3	/* going down with meta flush */
+
+#if defined(__KERNEL__) && defined(CONFIG_COMPAT)
+/*
+ * ioctl commands in 32 bit emulation
+ */
+#define F2FS_IOC32_GETFLAGS		FS_IOC32_GETFLAGS
+#define F2FS_IOC32_SETFLAGS		FS_IOC32_SETFLAGS
+#define F2FS_IOC32_GETVERSION		FS_IOC32_GETVERSION
+#endif
+
+#define F2FS_IOC_FSGETXATTR		FS_IOC_FSGETXATTR
+#define F2FS_IOC_FSSETXATTR		FS_IOC_FSSETXATTR
+
+struct f2fs_gc_range {
+	u32 sync;
+	u64 start;
+	u64 len;
+};
+
+struct f2fs_defragment {
+	u64 start;
+	u64 len;
+};
+
+struct f2fs_move_range {
+	u32 dst_fd;		/* destination fd */
+	u64 pos_in;		/* start position in src_fd */
+	u64 pos_out;		/* start position in dst_fd */
+	u64 len;		/* size to move */
+};
+
+struct f2fs_flush_device {
+	u32 dev_num;		/* device number to flush */
+	u32 segments;		/* # of segments to flush */
+};
+
+/* for inline stuff */
+#define DEF_INLINE_RESERVED_SIZE	1
+#define DEF_MIN_INLINE_SIZE		1
+static inline int get_extra_isize(struct inode *inode);
+static inline int get_inline_xattr_addrs(struct inode *inode);
+#define MAX_INLINE_DATA(inode)	(sizeof(__le32) *			\
+				(CUR_ADDRS_PER_INODE(inode) -		\
+				get_inline_xattr_addrs(inode) -	\
+				DEF_INLINE_RESERVED_SIZE))
+
+/* for inline dir */
+#define NR_INLINE_DENTRY(inode)	(MAX_INLINE_DATA(inode) * BITS_PER_BYTE / \
+				((SIZE_OF_DIR_ENTRY + F2FS_SLOT_LEN) * \
+				BITS_PER_BYTE + 1))
+#define INLINE_DENTRY_BITMAP_SIZE(inode)	((NR_INLINE_DENTRY(inode) + \
+					BITS_PER_BYTE - 1) / BITS_PER_BYTE)
+#define INLINE_RESERVED_SIZE(inode)	(MAX_INLINE_DATA(inode) - \
+				((SIZE_OF_DIR_ENTRY + F2FS_SLOT_LEN) * \
+				NR_INLINE_DENTRY(inode) + \
+				INLINE_DENTRY_BITMAP_SIZE(inode)))
+
+/*
+ * For INODE and NODE manager
+ */
+/* for directory operations */
+struct f2fs_dentry_ptr {
+	struct inode *inode;
+	void *bitmap;
+	struct f2fs_dir_entry *dentry;
+	__u8 (*filename)[F2FS_SLOT_LEN];
+	int max;
+	int nr_bitmap;
+};
+
+static inline void make_dentry_ptr_block(struct inode *inode,
+		struct f2fs_dentry_ptr *d, struct f2fs_dentry_block *t)
+{
+	d->inode = inode;
+	d->max = NR_DENTRY_IN_BLOCK;
+	d->nr_bitmap = SIZE_OF_DENTRY_BITMAP;
+	d->bitmap = t->dentry_bitmap;
+	d->dentry = t->dentry;
+	d->filename = t->filename;
+}
+
+static inline void make_dentry_ptr_inline(struct inode *inode,
+					struct f2fs_dentry_ptr *d, void *t)
+{
+	int entry_cnt = NR_INLINE_DENTRY(inode);
+	int bitmap_size = INLINE_DENTRY_BITMAP_SIZE(inode);
+	int reserved_size = INLINE_RESERVED_SIZE(inode);
+
+	d->inode = inode;
+	d->max = entry_cnt;
+	d->nr_bitmap = bitmap_size;
+	d->bitmap = t;
+	d->dentry = t + bitmap_size + reserved_size;
+	d->filename = t + bitmap_size + reserved_size +
+					SIZE_OF_DIR_ENTRY * entry_cnt;
+}
+
+/*
+ * XATTR_NODE_OFFSET stores xattrs to one node block per file keeping -1
+ * as its node offset to distinguish from index node blocks.
+ * But some bits are used to mark the node block.
+ */
+#define XATTR_NODE_OFFSET	((((unsigned int)-1) << OFFSET_BIT_SHIFT) \
+				>> OFFSET_BIT_SHIFT)
+enum {
+	ALLOC_NODE,			/* allocate a new node page if needed */
+	LOOKUP_NODE,			/* look up a node without readahead */
+	LOOKUP_NODE_RA,			/*
+					 * look up a node with readahead called
+					 * by get_data_block.
+					 */
+};
+
+#define F2FS_LINK_MAX	0xffffffff	/* maximum link count per file */
+
+#define MAX_DIR_RA_PAGES	4	/* maximum ra pages of dir */
+
+/* vector size for gang look-up from extent cache that consists of radix tree */
+#define EXT_TREE_VEC_SIZE	64
+
+/* for in-memory extent cache entry */
+#define F2FS_MIN_EXTENT_LEN	64	/* minimum extent length */
+
+/* number of extent info in extent cache we try to shrink */
+#define EXTENT_CACHE_SHRINK_NUMBER	128
+
+struct rb_entry {
+	struct rb_node rb_node;		/* rb node located in rb-tree */
+	unsigned int ofs;		/* start offset of the entry */
+	unsigned int len;		/* length of the entry */
+};
+
+struct extent_info {
+	unsigned int fofs;		/* start offset in a file */
+	unsigned int len;		/* length of the extent */
+	u32 blk;			/* start block address of the extent */
+};
+
+struct extent_node {
+	struct rb_node rb_node;
+	union {
+		struct {
+			unsigned int fofs;
+			unsigned int len;
+			u32 blk;
+		};
+		struct extent_info ei;	/* extent info */
+
+	};
+	struct list_head list;		/* node in global extent list of sbi */
+	struct extent_tree *et;		/* extent tree pointer */
+};
+
+struct extent_tree {
+	nid_t ino;			/* inode number */
+	struct rb_root root;		/* root of extent info rb-tree */
+	struct extent_node *cached_en;	/* recently accessed extent node */
+	struct extent_info largest;	/* largested extent info */
+	struct list_head list;		/* to be used by sbi->zombie_list */
+	rwlock_t lock;			/* protect extent info rb-tree */
+	atomic_t node_cnt;		/* # of extent node in rb-tree*/
+};
+
+/*
+ * This structure is taken from ext4_map_blocks.
+ *
+ * Note that, however, f2fs uses NEW and MAPPED flags for f2fs_map_blocks().
+ */
+#define F2FS_MAP_NEW		(1 << BH_New)
+#define F2FS_MAP_MAPPED		(1 << BH_Mapped)
+#define F2FS_MAP_UNWRITTEN	(1 << BH_Unwritten)
+#define F2FS_MAP_FLAGS		(F2FS_MAP_NEW | F2FS_MAP_MAPPED |\
+				F2FS_MAP_UNWRITTEN)
+
+struct f2fs_map_blocks {
+	block_t m_pblk;
+	block_t m_lblk;
+	unsigned int m_len;
+	unsigned int m_flags;
+	pgoff_t *m_next_pgofs;		/* point next possible non-hole pgofs */
+	pgoff_t *m_next_extent;		/* point to next possible extent */
+	int m_seg_type;
+};
+
+/* for flag in get_data_block */
+enum {
+	F2FS_GET_BLOCK_DEFAULT,
+	F2FS_GET_BLOCK_FIEMAP,
+	F2FS_GET_BLOCK_BMAP,
+	F2FS_GET_BLOCK_PRE_DIO,
+	F2FS_GET_BLOCK_PRE_AIO,
+	F2FS_GET_BLOCK_PRECACHE,
+};
+
+/*
+ * i_advise uses FADVISE_XXX_BIT. We can add additional hints later.
+ */
+#define FADVISE_COLD_BIT	0x01
+#define FADVISE_LOST_PINO_BIT	0x02
+#define FADVISE_ENCRYPT_BIT	0x04
+#define FADVISE_ENC_NAME_BIT	0x08
+#define FADVISE_KEEP_SIZE_BIT	0x10
+#define FADVISE_HOT_BIT		0x20
+#define FADVISE_VERITY_BIT	0x40	/* reserved */
+
+#define file_is_cold(inode)	is_file(inode, FADVISE_COLD_BIT)
+#define file_wrong_pino(inode)	is_file(inode, FADVISE_LOST_PINO_BIT)
+#define file_set_cold(inode)	set_file(inode, FADVISE_COLD_BIT)
+#define file_lost_pino(inode)	set_file(inode, FADVISE_LOST_PINO_BIT)
+#define file_clear_cold(inode)	clear_file(inode, FADVISE_COLD_BIT)
+#define file_got_pino(inode)	clear_file(inode, FADVISE_LOST_PINO_BIT)
+#define file_is_encrypt(inode)	is_file(inode, FADVISE_ENCRYPT_BIT)
+#define file_set_encrypt(inode)	set_file(inode, FADVISE_ENCRYPT_BIT)
+#define file_clear_encrypt(inode) clear_file(inode, FADVISE_ENCRYPT_BIT)
+#define file_enc_name(inode)	is_file(inode, FADVISE_ENC_NAME_BIT)
+#define file_set_enc_name(inode) set_file(inode, FADVISE_ENC_NAME_BIT)
+#define file_keep_isize(inode)	is_file(inode, FADVISE_KEEP_SIZE_BIT)
+#define file_set_keep_isize(inode) set_file(inode, FADVISE_KEEP_SIZE_BIT)
+#define file_is_hot(inode)	is_file(inode, FADVISE_HOT_BIT)
+#define file_set_hot(inode)	set_file(inode, FADVISE_HOT_BIT)
+#define file_clear_hot(inode)	clear_file(inode, FADVISE_HOT_BIT)
+
+#define DEF_DIR_LEVEL		0
+
+struct f2fs_inode_info {
+	struct inode vfs_inode;		/* serve a vfs inode */
+	unsigned long i_flags;		/* keep an inode flags for ioctl */
+	unsigned char i_advise;		/* use to give file attribute hints */
+	unsigned char i_dir_level;	/* use for dentry level for large dir */
+	union {
+		unsigned int i_current_depth;	/* only for directory depth */
+		unsigned short i_gc_failures;	/* only for regular file */
+	};
+	unsigned int i_pino;		/* parent inode number */
+	umode_t i_acl_mode;		/* keep file acl mode temporarily */
+
+	/* Use below internally in f2fs*/
+	unsigned long flags;		/* use to pass per-file flags */
+	struct rw_semaphore i_sem;	/* protect fi info */
+	atomic_t dirty_pages;		/* # of dirty pages */
+	f2fs_hash_t chash;		/* hash value of given file name */
+	unsigned int clevel;		/* maximum level of given file name */
+	struct task_struct *task;	/* lookup and create consistency */
+	struct task_struct *cp_task;	/* separate cp/wb IO stats*/
+	nid_t i_xattr_nid;		/* node id that contains xattrs */
+	loff_t	last_disk_size;		/* lastly written file size */
+
+#ifdef CONFIG_QUOTA
+	struct dquot *i_dquot[MAXQUOTAS];
+
+	/* quota space reservation, managed internally by quota code */
+	qsize_t i_reserved_quota;
+#endif
+	struct list_head dirty_list;	/* dirty list for dirs and files */
+	struct list_head gdirty_list;	/* linked in global dirty list */
+	struct list_head inmem_ilist;	/* list for inmem inodes */
+	struct list_head inmem_pages;	/* inmemory pages managed by f2fs */
+	struct task_struct *inmem_task;	/* store inmemory task */
+	struct mutex inmem_lock;	/* lock for inmemory pages */
+	struct extent_tree *extent_tree;	/* cached extent_tree entry */
+	struct rw_semaphore dio_rwsem[2];/* avoid racing between dio and gc */
+	struct rw_semaphore i_mmap_sem;
+	struct rw_semaphore i_xattr_sem; /* avoid racing between reading and changing EAs */
+
+	int i_extra_isize;		/* size of extra space located in i_addr */
+	kprojid_t i_projid;		/* id for project quota */
+	int i_inline_xattr_size;	/* inline xattr size */
+	struct timespec i_crtime;	/* inode creation time */
+	struct timespec i_disk_time[4];	/* inode disk times */
+};
+
+static inline void get_extent_info(struct extent_info *ext,
+					struct f2fs_extent *i_ext)
+{
+	ext->fofs = le32_to_cpu(i_ext->fofs);
+	ext->blk = le32_to_cpu(i_ext->blk);
+	ext->len = le32_to_cpu(i_ext->len);
+}
+
+static inline void set_raw_extent(struct extent_info *ext,
+					struct f2fs_extent *i_ext)
+{
+	i_ext->fofs = cpu_to_le32(ext->fofs);
+	i_ext->blk = cpu_to_le32(ext->blk);
+	i_ext->len = cpu_to_le32(ext->len);
+}
+
+static inline void set_extent_info(struct extent_info *ei, unsigned int fofs,
+						u32 blk, unsigned int len)
+{
+	ei->fofs = fofs;
+	ei->blk = blk;
+	ei->len = len;
+}
+
+static inline bool __is_discard_mergeable(struct discard_info *back,
+						struct discard_info *front)
+{
+	return (back->lstart + back->len == front->lstart) &&
+		(back->len + front->len < DEF_MAX_DISCARD_LEN);
+}
+
+static inline bool __is_discard_back_mergeable(struct discard_info *cur,
+						struct discard_info *back)
+{
+	return __is_discard_mergeable(back, cur);
+}
+
+static inline bool __is_discard_front_mergeable(struct discard_info *cur,
+						struct discard_info *front)
+{
+	return __is_discard_mergeable(cur, front);
+}
+
+static inline bool __is_extent_mergeable(struct extent_info *back,
+						struct extent_info *front)
+{
+	return (back->fofs + back->len == front->fofs &&
+			back->blk + back->len == front->blk);
+}
+
+static inline bool __is_back_mergeable(struct extent_info *cur,
+						struct extent_info *back)
+{
+	return __is_extent_mergeable(back, cur);
+}
+
+static inline bool __is_front_mergeable(struct extent_info *cur,
+						struct extent_info *front)
+{
+	return __is_extent_mergeable(cur, front);
+}
+
+extern void f2fs_mark_inode_dirty_sync(struct inode *inode, bool sync);
+static inline void __try_update_largest_extent(struct inode *inode,
+			struct extent_tree *et, struct extent_node *en)
+{
+	if (en->ei.len > et->largest.len) {
+		et->largest = en->ei;
+		f2fs_mark_inode_dirty_sync(inode, true);
+	}
+}
+
+/*
+ * For free nid management
+ */
+enum nid_state {
+	FREE_NID,		/* newly added to free nid list */
+	PREALLOC_NID,		/* it is preallocated */
+	MAX_NID_STATE,
+};
+
+struct f2fs_nm_info {
+	block_t nat_blkaddr;		/* base disk address of NAT */
+	nid_t max_nid;			/* maximum possible node ids */
+	nid_t available_nids;		/* # of available node ids */
+	nid_t next_scan_nid;		/* the next nid to be scanned */
+	unsigned int ram_thresh;	/* control the memory footprint */
+	unsigned int ra_nid_pages;	/* # of nid pages to be readaheaded */
+	unsigned int dirty_nats_ratio;	/* control dirty nats ratio threshold */
+
+	/* NAT cache management */
+	struct radix_tree_root nat_root;/* root of the nat entry cache */
+	struct radix_tree_root nat_set_root;/* root of the nat set cache */
+	struct rw_semaphore nat_tree_lock;	/* protect nat_tree_lock */
+	struct list_head nat_entries;	/* cached nat entry list (clean) */
+	unsigned int nat_cnt;		/* the # of cached nat entries */
+	unsigned int dirty_nat_cnt;	/* total num of nat entries in set */
+	unsigned int nat_blocks;	/* # of nat blocks */
+
+	/* free node ids management */
+	struct radix_tree_root free_nid_root;/* root of the free_nid cache */
+	struct list_head free_nid_list;		/* list for free nids excluding preallocated nids */
+	unsigned int nid_cnt[MAX_NID_STATE];	/* the number of free node id */
+	spinlock_t nid_list_lock;	/* protect nid lists ops */
+	struct mutex build_lock;	/* lock for build free nids */
+	unsigned char **free_nid_bitmap;
+	unsigned char *nat_block_bitmap;
+	unsigned short *free_nid_count;	/* free nid count of NAT block */
+
+	/* for checkpoint */
+	char *nat_bitmap;		/* NAT bitmap pointer */
+
+	unsigned int nat_bits_blocks;	/* # of nat bits blocks */
+	unsigned char *nat_bits;	/* NAT bits blocks */
+	unsigned char *full_nat_bits;	/* full NAT pages */
+	unsigned char *empty_nat_bits;	/* empty NAT pages */
+#ifdef CONFIG_F2FS_CHECK_FS
+	char *nat_bitmap_mir;		/* NAT bitmap mirror */
+#endif
+	int bitmap_size;		/* bitmap size */
+};
+
+/*
+ * this structure is used as one of function parameters.
+ * all the information are dedicated to a given direct node block determined
+ * by the data offset in a file.
+ */
+struct dnode_of_data {
+	struct inode *inode;		/* vfs inode pointer */
+	struct page *inode_page;	/* its inode page, NULL is possible */
+	struct page *node_page;		/* cached direct node page */
+	nid_t nid;			/* node id of the direct node block */
+	unsigned int ofs_in_node;	/* data offset in the node page */
+	bool inode_page_locked;		/* inode page is locked or not */
+	bool node_changed;		/* is node block changed */
+	char cur_level;			/* level of hole node page */
+	char max_level;			/* level of current page located */
+	block_t	data_blkaddr;		/* block address of the node block */
+};
+
+static inline void set_new_dnode(struct dnode_of_data *dn, struct inode *inode,
+		struct page *ipage, struct page *npage, nid_t nid)
+{
+	memset(dn, 0, sizeof(*dn));
+	dn->inode = inode;
+	dn->inode_page = ipage;
+	dn->node_page = npage;
+	dn->nid = nid;
+}
+
+/*
+ * For SIT manager
+ *
+ * By default, there are 6 active log areas across the whole main area.
+ * When considering hot and cold data separation to reduce cleaning overhead,
+ * we split 3 for data logs and 3 for node logs as hot, warm, and cold types,
+ * respectively.
+ * In the current design, you should not change the numbers intentionally.
+ * Instead, as a mount option such as active_logs=x, you can use 2, 4, and 6
+ * logs individually according to the underlying devices. (default: 6)
+ * Just in case, on-disk layout covers maximum 16 logs that consist of 8 for
+ * data and 8 for node logs.
+ */
+#define	NR_CURSEG_DATA_TYPE	(3)
+#define NR_CURSEG_NODE_TYPE	(3)
+#define NR_CURSEG_TYPE	(NR_CURSEG_DATA_TYPE + NR_CURSEG_NODE_TYPE)
+
+enum {
+	CURSEG_HOT_DATA	= 0,	/* directory entry blocks */
+	CURSEG_WARM_DATA,	/* data blocks */
+	CURSEG_COLD_DATA,	/* multimedia or GCed data blocks */
+	CURSEG_HOT_NODE,	/* direct node blocks of directory files */
+	CURSEG_WARM_NODE,	/* direct node blocks of normal files */
+	CURSEG_COLD_NODE,	/* indirect node blocks */
+	NO_CHECK_TYPE,
+};
+
+struct flush_cmd {
+	struct completion wait;
+	struct llist_node llnode;
+	nid_t ino;
+	int ret;
+};
+
+struct flush_cmd_control {
+	struct task_struct *f2fs_issue_flush;	/* flush thread */
+	wait_queue_head_t flush_wait_queue;	/* waiting queue for wake-up */
+	atomic_t issued_flush;			/* # of issued flushes */
+	atomic_t issing_flush;			/* # of issing flushes */
+	struct llist_head issue_list;		/* list for command issue */
+	struct llist_node *dispatch_list;	/* list for command dispatch */
+};
+
+struct f2fs_sm_info {
+	struct sit_info *sit_info;		/* whole segment information */
+	struct free_segmap_info *free_info;	/* free segment information */
+	struct dirty_seglist_info *dirty_info;	/* dirty segment information */
+	struct curseg_info *curseg_array;	/* active segment information */
+
+	struct rw_semaphore curseg_lock;	/* for preventing curseg change */
+
+	block_t seg0_blkaddr;		/* block address of 0'th segment */
+	block_t main_blkaddr;		/* start block address of main area */
+	block_t ssa_blkaddr;		/* start block address of SSA area */
+
+	unsigned int segment_count;	/* total # of segments */
+	unsigned int main_segments;	/* # of segments in main area */
+	unsigned int reserved_segments;	/* # of reserved segments */
+	unsigned int ovp_segments;	/* # of overprovision segments */
+
+	/* a threshold to reclaim prefree segments */
+	unsigned int rec_prefree_segments;
+
+	/* for batched trimming */
+	unsigned int trim_sections;		/* # of sections to trim */
+
+	struct list_head sit_entry_set;	/* sit entry set list */
+
+	unsigned int ipu_policy;	/* in-place-update policy */
+	unsigned int min_ipu_util;	/* in-place-update threshold */
+	unsigned int min_fsync_blocks;	/* threshold for fsync */
+	unsigned int min_hot_blocks;	/* threshold for hot block allocation */
+	unsigned int min_ssr_sections;	/* threshold to trigger SSR allocation */
+
+	/* for flush command control */
+	struct flush_cmd_control *fcc_info;
+
+	/* for discard command control */
+	struct discard_cmd_control *dcc_info;
+};
+
+/*
+ * For superblock
+ */
+/*
+ * COUNT_TYPE for monitoring
+ *
+ * f2fs monitors the number of several block types such as on-writeback,
+ * dirty dentry blocks, dirty node blocks, and dirty meta blocks.
+ */
+#define WB_DATA_TYPE(p)	(__is_cp_guaranteed(p) ? F2FS_WB_CP_DATA : F2FS_WB_DATA)
+enum count_type {
+	F2FS_DIRTY_DENTS,
+	F2FS_DIRTY_DATA,
+	F2FS_DIRTY_QDATA,
+	F2FS_DIRTY_NODES,
+	F2FS_DIRTY_META,
+	F2FS_INMEM_PAGES,
+	F2FS_DIRTY_IMETA,
+	F2FS_WB_CP_DATA,
+	F2FS_WB_DATA,
+	NR_COUNT_TYPE,
+};
+
+/*
+ * The below are the page types of bios used in submit_bio().
+ * The available types are:
+ * DATA			User data pages. It operates as async mode.
+ * NODE			Node pages. It operates as async mode.
+ * META			FS metadata pages such as SIT, NAT, CP.
+ * NR_PAGE_TYPE		The number of page types.
+ * META_FLUSH		Make sure the previous pages are written
+ *			with waiting the bio's completion
+ * ...			Only can be used with META.
+ */
+#define PAGE_TYPE_OF_BIO(type)	((type) > META ? META : (type))
+enum page_type {
+	DATA,
+	NODE,
+	META,
+	NR_PAGE_TYPE,
+	META_FLUSH,
+	INMEM,		/* the below types are used by tracepoints only. */
+	INMEM_DROP,
+	INMEM_INVALIDATE,
+	INMEM_REVOKE,
+	IPU,
+	OPU,
+};
+
+enum temp_type {
+	HOT = 0,	/* must be zero for meta bio */
+	WARM,
+	COLD,
+	NR_TEMP_TYPE,
+};
+
+enum need_lock_type {
+	LOCK_REQ = 0,
+	LOCK_DONE,
+	LOCK_RETRY,
+};
+
+enum cp_reason_type {
+	CP_NO_NEEDED,
+	CP_NON_REGULAR,
+	CP_HARDLINK,
+	CP_SB_NEED_CP,
+	CP_WRONG_PINO,
+	CP_NO_SPC_ROLL,
+	CP_NODE_NEED_CP,
+	CP_FASTBOOT_MODE,
+	CP_SPEC_LOG_NUM,
+	CP_RECOVER_DIR,
+};
+
+enum iostat_type {
+	APP_DIRECT_IO,			/* app direct IOs */
+	APP_BUFFERED_IO,		/* app buffered IOs */
+	APP_WRITE_IO,			/* app write IOs */
+	APP_MAPPED_IO,			/* app mapped IOs */
+	FS_DATA_IO,			/* data IOs from kworker/fsync/reclaimer */
+	FS_NODE_IO,			/* node IOs from kworker/fsync/reclaimer */
+	FS_META_IO,			/* meta IOs from kworker/reclaimer */
+	FS_GC_DATA_IO,			/* data IOs from forground gc */
+	FS_GC_NODE_IO,			/* node IOs from forground gc */
+	FS_CP_DATA_IO,			/* data IOs from checkpoint */
+	FS_CP_NODE_IO,			/* node IOs from checkpoint */
+	FS_CP_META_IO,			/* meta IOs from checkpoint */
+	FS_DISCARD,			/* discard */
+	NR_IO_TYPE,
+};
+
+struct f2fs_io_info {
+	struct f2fs_sb_info *sbi;	/* f2fs_sb_info pointer */
+	nid_t ino;		/* inode number */
+	enum page_type type;	/* contains DATA/NODE/META/META_FLUSH */
+	enum temp_type temp;	/* contains HOT/WARM/COLD */
+	int op;			/* contains REQ_OP_ */
+	int op_flags;		/* req_flag_bits */
+	block_t new_blkaddr;	/* new block address to be written */
+	block_t old_blkaddr;	/* old block address before Cow */
+	struct page *page;	/* page to be written */
+	struct page *encrypted_page;	/* encrypted page */
+	struct list_head list;		/* serialize IOs */
+	bool submitted;		/* indicate IO submission */
+	int need_lock;		/* indicate we need to lock cp_rwsem */
+	bool in_list;		/* indicate fio is in io_list */
+	bool is_meta;		/* indicate borrow meta inode mapping or not */
+	enum iostat_type io_type;	/* io type */
+	struct writeback_control *io_wbc; /* writeback control */
+};
+
+#define is_read_io(rw) ((rw) == READ)
+struct f2fs_bio_info {
+	struct f2fs_sb_info *sbi;	/* f2fs superblock */
+	struct bio *bio;		/* bios to merge */
+	sector_t last_block_in_bio;	/* last block number */
+	struct f2fs_io_info fio;	/* store buffered io info. */
+	struct rw_semaphore io_rwsem;	/* blocking op for bio */
+	spinlock_t io_lock;		/* serialize DATA/NODE IOs */
+	struct list_head io_list;	/* track fios */
+};
+
+#define FDEV(i)				(sbi->devs[i])
+#define RDEV(i)				(raw_super->devs[i])
+struct f2fs_dev_info {
+	struct block_device *bdev;
+	char path[MAX_PATH_LEN];
+	unsigned int total_segments;
+	block_t start_blk;
+	block_t end_blk;
+#ifdef CONFIG_BLK_DEV_ZONED
+	unsigned int nr_blkz;			/* Total number of zones */
+	u8 *blkz_type;				/* Array of zones type */
+#endif
+};
+
+enum inode_type {
+	DIR_INODE,			/* for dirty dir inode */
+	FILE_INODE,			/* for dirty regular/symlink inode */
+	DIRTY_META,			/* for all dirtied inode metadata */
+	ATOMIC_FILE,			/* for all atomic files */
+	NR_INODE_TYPE,
+};
+
+/* for inner inode cache management */
+struct inode_management {
+	struct radix_tree_root ino_root;	/* ino entry array */
+	spinlock_t ino_lock;			/* for ino entry lock */
+	struct list_head ino_list;		/* inode list head */
+	unsigned long ino_num;			/* number of entries */
+};
+
+/* For s_flag in struct f2fs_sb_info */
+enum {
+	SBI_IS_DIRTY,				/* dirty flag for checkpoint */
+	SBI_IS_CLOSE,				/* specify unmounting */
+	SBI_NEED_FSCK,				/* need fsck.f2fs to fix */
+	SBI_POR_DOING,				/* recovery is doing or not */
+	SBI_NEED_SB_WRITE,			/* need to recover superblock */
+	SBI_NEED_CP,				/* need to checkpoint */
+};
+
+enum {
+	CP_TIME,
+	REQ_TIME,
+	MAX_TIME,
+};
+
+enum {
+	WHINT_MODE_OFF,		/* not pass down write hints */
+	WHINT_MODE_USER,	/* try to pass down hints given by users */
+	WHINT_MODE_FS,		/* pass down hints with F2FS policy */
+};
+
+enum {
+	ALLOC_MODE_DEFAULT,	/* stay default */
+	ALLOC_MODE_REUSE,	/* reuse segments as much as possible */
+};
+
+enum fsync_mode {
+	FSYNC_MODE_POSIX,	/* fsync follows posix semantics */
+	FSYNC_MODE_STRICT,	/* fsync behaves in line with ext4 */
+	FSYNC_MODE_NOBARRIER,	/* fsync behaves nobarrier based on posix */
+};
+
+#ifdef CONFIG_F2FS_FS_ENCRYPTION
+#define DUMMY_ENCRYPTION_ENABLED(sbi) \
+			(unlikely(F2FS_OPTION(sbi).test_dummy_encryption))
+#else
+#define DUMMY_ENCRYPTION_ENABLED(sbi) (0)
+#endif
+
+struct f2fs_sb_info {
+	struct super_block *sb;			/* pointer to VFS super block */
+	struct proc_dir_entry *s_proc;		/* proc entry */
+	struct f2fs_super_block *raw_super;	/* raw super block pointer */
+	struct rw_semaphore sb_lock;		/* lock for raw super block */
+	int valid_super_block;			/* valid super block no */
+	unsigned long s_flag;				/* flags for sbi */
+
+#ifdef CONFIG_BLK_DEV_ZONED
+	unsigned int blocks_per_blkz;		/* F2FS blocks per zone */
+	unsigned int log_blocks_per_blkz;	/* log2 F2FS blocks per zone */
+#endif
+
+	/* for node-related operations */
+	struct f2fs_nm_info *nm_info;		/* node manager */
+	struct inode *node_inode;		/* cache node blocks */
+
+	/* for segment-related operations */
+	struct f2fs_sm_info *sm_info;		/* segment manager */
+
+	/* for bio operations */
+	struct f2fs_bio_info *write_io[NR_PAGE_TYPE];	/* for write bios */
+	struct mutex wio_mutex[NR_PAGE_TYPE - 1][NR_TEMP_TYPE];
+						/* bio ordering for NODE/DATA */
+	mempool_t *write_io_dummy;		/* Dummy pages */
+
+	/* for checkpoint */
+	struct f2fs_checkpoint *ckpt;		/* raw checkpoint pointer */
+	int cur_cp_pack;			/* remain current cp pack */
+	spinlock_t cp_lock;			/* for flag in ckpt */
+	struct inode *meta_inode;		/* cache meta blocks */
+	struct mutex cp_mutex;			/* checkpoint procedure lock */
+	struct rw_semaphore cp_rwsem;		/* blocking FS operations */
+	struct rw_semaphore node_write;		/* locking node writes */
+	struct rw_semaphore node_change;	/* locking node change */
+	wait_queue_head_t cp_wait;
+	unsigned long last_time[MAX_TIME];	/* to store time in jiffies */
+	long interval_time[MAX_TIME];		/* to store thresholds */
+
+	struct inode_management im[MAX_INO_ENTRY];      /* manage inode cache */
+
+	/* for orphan inode, use 0'th array */
+	unsigned int max_orphans;		/* max orphan inodes */
+
+	/* for inode management */
+	struct list_head inode_list[NR_INODE_TYPE];	/* dirty inode list */
+	spinlock_t inode_lock[NR_INODE_TYPE];	/* for dirty inode list lock */
+
+	/* for extent tree cache */
+	struct radix_tree_root extent_tree_root;/* cache extent cache entries */
+	struct mutex extent_tree_lock;	/* locking extent radix tree */
+	struct list_head extent_list;		/* lru list for shrinker */
+	spinlock_t extent_lock;			/* locking extent lru list */
+	atomic_t total_ext_tree;		/* extent tree count */
+	struct list_head zombie_list;		/* extent zombie tree list */
+	atomic_t total_zombie_tree;		/* extent zombie tree count */
+	atomic_t total_ext_node;		/* extent info count */
+
+	/* basic filesystem units */
+	unsigned int log_sectors_per_block;	/* log2 sectors per block */
+	unsigned int log_blocksize;		/* log2 block size */
+	unsigned int blocksize;			/* block size */
+	unsigned int root_ino_num;		/* root inode number*/
+	unsigned int node_ino_num;		/* node inode number*/
+	unsigned int meta_ino_num;		/* meta inode number*/
+	unsigned int log_blocks_per_seg;	/* log2 blocks per segment */
+	unsigned int blocks_per_seg;		/* blocks per segment */
+	unsigned int segs_per_sec;		/* segments per section */
+	unsigned int secs_per_zone;		/* sections per zone */
+	unsigned int total_sections;		/* total section count */
+	unsigned int total_node_count;		/* total node block count */
+	unsigned int total_valid_node_count;	/* valid node block count */
+	loff_t max_file_blocks;			/* max block index of file */
+	int dir_level;				/* directory level */
+	unsigned int trigger_ssr_threshold;	/* threshold to trigger ssr */
+	int readdir_ra;				/* readahead inode in readdir */
+
+	block_t user_block_count;		/* # of user blocks */
+	block_t total_valid_block_count;	/* # of valid blocks */
+	block_t discard_blks;			/* discard command candidats */
+	block_t last_valid_block_count;		/* for recovery */
+	block_t reserved_blocks;		/* configurable reserved blocks */
+	block_t current_reserved_blocks;	/* current reserved blocks */
+
+	unsigned int nquota_files;		/* # of quota sysfile */
+
+	u32 s_next_generation;			/* for NFS support */
+
+	/* # of pages, see count_type */
+	atomic_t nr_pages[NR_COUNT_TYPE];
+	/* # of allocated blocks */
+	struct percpu_counter alloc_valid_block_count;
+
+	/* writeback control */
+	atomic_t wb_sync_req;			/* count # of WB_SYNC threads */
+
+	/* valid inode count */
+	struct percpu_counter total_valid_inode_count;
+
+	struct f2fs_mount_info mount_opt;	/* mount options */
+
+	/* for cleaning operations */
+	struct mutex gc_mutex;			/* mutex for GC */
+	struct f2fs_gc_kthread	*gc_thread;	/* GC thread */
+	unsigned int cur_victim_sec;		/* current victim section num */
+
+	/* threshold for converting bg victims for fg */
+	u64 fggc_threshold;
+
+	/* threshold for gc trials on pinned files */
+	u64 gc_pin_file_threshold;
+
+	/* maximum # of trials to find a victim segment for SSR and GC */
+	unsigned int max_victim_search;
+
+	/*
+	 * for stat information.
+	 * one is for the LFS mode, and the other is for the SSR mode.
+	 */
+#ifdef CONFIG_F2FS_STAT_FS
+	struct f2fs_stat_info *stat_info;	/* FS status information */
+	unsigned int segment_count[2];		/* # of allocated segments */
+	unsigned int block_count[2];		/* # of allocated blocks */
+	atomic_t inplace_count;		/* # of inplace update */
+	atomic64_t total_hit_ext;		/* # of lookup extent cache */
+	atomic64_t read_hit_rbtree;		/* # of hit rbtree extent node */
+	atomic64_t read_hit_largest;		/* # of hit largest extent node */
+	atomic64_t read_hit_cached;		/* # of hit cached extent node */
+	atomic_t inline_xattr;			/* # of inline_xattr inodes */
+	atomic_t inline_inode;			/* # of inline_data inodes */
+	atomic_t inline_dir;			/* # of inline_dentry inodes */
+	atomic_t aw_cnt;			/* # of atomic writes */
+	atomic_t vw_cnt;			/* # of volatile writes */
+	atomic_t max_aw_cnt;			/* max # of atomic writes */
+	atomic_t max_vw_cnt;			/* max # of volatile writes */
+	int bg_gc;				/* background gc calls */
+	unsigned int ndirty_inode[NR_INODE_TYPE];	/* # of dirty inodes */
+#endif
+	spinlock_t stat_lock;			/* lock for stat operations */
+
+	/* For app/fs IO statistics */
+	spinlock_t iostat_lock;
+	unsigned long long write_iostat[NR_IO_TYPE];
+	bool iostat_enable;
+
+	/* For sysfs suppport */
+	struct kobject s_kobj;
+	struct completion s_kobj_unregister;
+
+	/* For shrinker support */
+	struct list_head s_list;
+	int s_ndevs;				/* number of devices */
+	struct f2fs_dev_info *devs;		/* for device list */
+	unsigned int dirty_device;		/* for checkpoint data flush */
+	spinlock_t dev_lock;			/* protect dirty_device */
+	struct mutex umount_mutex;
+	unsigned int shrinker_run_no;
+
+	/* For write statistics */
+	u64 sectors_written_start;
+	u64 kbytes_written;
+
+	/* Reference to checksum algorithm driver via cryptoapi */
+	struct crypto_shash *s_chksum_driver;
+
+	/* Precomputed FS UUID checksum for seeding other checksums */
+	__u32 s_chksum_seed;
+};
+
+#ifdef CONFIG_F2FS_FAULT_INJECTION
+#define f2fs_show_injection_info(type)				\
+	printk("%sF2FS-fs : inject %s in %s of %pF\n",		\
+		KERN_INFO, fault_name[type],			\
+		__func__, __builtin_return_address(0))
+static inline bool time_to_inject(struct f2fs_sb_info *sbi, int type)
+{
+	struct f2fs_fault_info *ffi = &F2FS_OPTION(sbi).fault_info;
+
+	if (!ffi->inject_rate)
+		return false;
+
+	if (!IS_FAULT_SET(ffi, type))
+		return false;
+
+	atomic_inc(&ffi->inject_ops);
+	if (atomic_read(&ffi->inject_ops) >= ffi->inject_rate) {
+		atomic_set(&ffi->inject_ops, 0);
+		return true;
+	}
+	return false;
+}
+#endif
+
+/*
+ * Test if the mounted volume is a multi-device volume.
+ *   - For a single regular disk volume, sbi->s_ndevs is 0.
+ *   - For a single zoned disk volume, sbi->s_ndevs is 1.
+ *   - For a multi-device volume, sbi->s_ndevs is always 2 or more.
+ */
+static inline bool f2fs_is_multi_device(struct f2fs_sb_info *sbi)
+{
+	return sbi->s_ndevs > 1;
+}
+
+/* For write statistics. Suppose sector size is 512 bytes,
+ * and the return value is in kbytes. s is of struct f2fs_sb_info.
+ */
+#define BD_PART_WRITTEN(s)						 \
+(((u64)part_stat_read((s)->sb->s_bdev->bd_part, sectors[1]) -		 \
+		(s)->sectors_written_start) >> 1)
+
+static inline void f2fs_update_time(struct f2fs_sb_info *sbi, int type)
+{
+	sbi->last_time[type] = jiffies;
+}
+
+static inline bool f2fs_time_over(struct f2fs_sb_info *sbi, int type)
+{
+	unsigned long interval = sbi->interval_time[type] * HZ;
+
+	return time_after(jiffies, sbi->last_time[type] + interval);
+}
+
+static inline bool is_idle(struct f2fs_sb_info *sbi)
+{
+	struct block_device *bdev = sbi->sb->s_bdev;
+	struct request_queue *q = bdev_get_queue(bdev);
+	struct request_list *rl = &q->root_rl;
+
+	if (rl->count[BLK_RW_SYNC] || rl->count[BLK_RW_ASYNC])
+		return 0;
+
+	return f2fs_time_over(sbi, REQ_TIME);
+}
+
+/*
+ * Inline functions
+ */
+static inline u32 __f2fs_crc32(struct f2fs_sb_info *sbi, u32 crc,
+			      const void *address, unsigned int length)
+{
+	struct {
+		struct shash_desc shash;
+		char ctx[4];
+	} desc;
+	int err;
+
+	BUG_ON(crypto_shash_descsize(sbi->s_chksum_driver) != sizeof(desc.ctx));
+
+	desc.shash.tfm = sbi->s_chksum_driver;
+	desc.shash.flags = 0;
+	*(u32 *)desc.ctx = crc;
+
+	err = crypto_shash_update(&desc.shash, address, length);
+	BUG_ON(err);
+
+	return *(u32 *)desc.ctx;
+}
+
+static inline u32 f2fs_crc32(struct f2fs_sb_info *sbi, const void *address,
+			   unsigned int length)
+{
+	return __f2fs_crc32(sbi, F2FS_SUPER_MAGIC, address, length);
+}
+
+static inline bool f2fs_crc_valid(struct f2fs_sb_info *sbi, __u32 blk_crc,
+				  void *buf, size_t buf_size)
+{
+	return f2fs_crc32(sbi, buf, buf_size) == blk_crc;
+}
+
+static inline u32 f2fs_chksum(struct f2fs_sb_info *sbi, u32 crc,
+			      const void *address, unsigned int length)
+{
+	return __f2fs_crc32(sbi, crc, address, length);
+}
+
+static inline struct f2fs_inode_info *F2FS_I(struct inode *inode)
+{
+	return container_of(inode, struct f2fs_inode_info, vfs_inode);
+}
+
+static inline struct f2fs_sb_info *F2FS_SB(struct super_block *sb)
+{
+	return sb->s_fs_info;
+}
+
+static inline struct f2fs_sb_info *F2FS_I_SB(struct inode *inode)
+{
+	return F2FS_SB(inode->i_sb);
+}
+
+static inline struct f2fs_sb_info *F2FS_M_SB(struct address_space *mapping)
+{
+	return F2FS_I_SB(mapping->host);
+}
+
+static inline struct f2fs_sb_info *F2FS_P_SB(struct page *page)
+{
+	return F2FS_M_SB(page->mapping);
+}
+
+static inline struct f2fs_super_block *F2FS_RAW_SUPER(struct f2fs_sb_info *sbi)
+{
+	return (struct f2fs_super_block *)(sbi->raw_super);
+}
+
+static inline struct f2fs_checkpoint *F2FS_CKPT(struct f2fs_sb_info *sbi)
+{
+	return (struct f2fs_checkpoint *)(sbi->ckpt);
+}
+
+static inline struct f2fs_node *F2FS_NODE(struct page *page)
+{
+	return (struct f2fs_node *)page_address(page);
+}
+
+static inline struct f2fs_inode *F2FS_INODE(struct page *page)
+{
+	return &((struct f2fs_node *)page_address(page))->i;
+}
+
+static inline struct f2fs_nm_info *NM_I(struct f2fs_sb_info *sbi)
+{
+	return (struct f2fs_nm_info *)(sbi->nm_info);
+}
+
+static inline struct f2fs_sm_info *SM_I(struct f2fs_sb_info *sbi)
+{
+	return (struct f2fs_sm_info *)(sbi->sm_info);
+}
+
+static inline struct sit_info *SIT_I(struct f2fs_sb_info *sbi)
+{
+	return (struct sit_info *)(SM_I(sbi)->sit_info);
+}
+
+static inline struct free_segmap_info *FREE_I(struct f2fs_sb_info *sbi)
+{
+	return (struct free_segmap_info *)(SM_I(sbi)->free_info);
+}
+
+static inline struct dirty_seglist_info *DIRTY_I(struct f2fs_sb_info *sbi)
+{
+	return (struct dirty_seglist_info *)(SM_I(sbi)->dirty_info);
+}
+
+static inline struct address_space *META_MAPPING(struct f2fs_sb_info *sbi)
+{
+	return sbi->meta_inode->i_mapping;
+}
+
+static inline struct address_space *NODE_MAPPING(struct f2fs_sb_info *sbi)
+{
+	return sbi->node_inode->i_mapping;
+}
+
+static inline bool is_sbi_flag_set(struct f2fs_sb_info *sbi, unsigned int type)
+{
+	return test_bit(type, &sbi->s_flag);
+}
+
+static inline void set_sbi_flag(struct f2fs_sb_info *sbi, unsigned int type)
+{
+	set_bit(type, &sbi->s_flag);
+}
+
+static inline void clear_sbi_flag(struct f2fs_sb_info *sbi, unsigned int type)
+{
+	clear_bit(type, &sbi->s_flag);
+}
+
+static inline unsigned long long cur_cp_version(struct f2fs_checkpoint *cp)
+{
+	return le64_to_cpu(cp->checkpoint_ver);
+}
+
+static inline unsigned long f2fs_qf_ino(struct super_block *sb, int type)
+{
+	if (type < F2FS_MAX_QUOTAS)
+		return le32_to_cpu(F2FS_SB(sb)->raw_super->qf_ino[type]);
+	return 0;
+}
+
+static inline __u64 cur_cp_crc(struct f2fs_checkpoint *cp)
+{
+	size_t crc_offset = le32_to_cpu(cp->checksum_offset);
+	return le32_to_cpu(*((__le32 *)((unsigned char *)cp + crc_offset)));
+}
+
+static inline bool __is_set_ckpt_flags(struct f2fs_checkpoint *cp, unsigned int f)
+{
+	unsigned int ckpt_flags = le32_to_cpu(cp->ckpt_flags);
+
+	return ckpt_flags & f;
+}
+
+static inline bool is_set_ckpt_flags(struct f2fs_sb_info *sbi, unsigned int f)
+{
+	return __is_set_ckpt_flags(F2FS_CKPT(sbi), f);
+}
+
+static inline void __set_ckpt_flags(struct f2fs_checkpoint *cp, unsigned int f)
+{
+	unsigned int ckpt_flags;
+
+	ckpt_flags = le32_to_cpu(cp->ckpt_flags);
+	ckpt_flags |= f;
+	cp->ckpt_flags = cpu_to_le32(ckpt_flags);
+}
+
+static inline void set_ckpt_flags(struct f2fs_sb_info *sbi, unsigned int f)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&sbi->cp_lock, flags);
+	__set_ckpt_flags(F2FS_CKPT(sbi), f);
+	spin_unlock_irqrestore(&sbi->cp_lock, flags);
+}
+
+static inline void __clear_ckpt_flags(struct f2fs_checkpoint *cp, unsigned int f)
+{
+	unsigned int ckpt_flags;
+
+	ckpt_flags = le32_to_cpu(cp->ckpt_flags);
+	ckpt_flags &= (~f);
+	cp->ckpt_flags = cpu_to_le32(ckpt_flags);
+}
+
+static inline void clear_ckpt_flags(struct f2fs_sb_info *sbi, unsigned int f)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&sbi->cp_lock, flags);
+	__clear_ckpt_flags(F2FS_CKPT(sbi), f);
+	spin_unlock_irqrestore(&sbi->cp_lock, flags);
+}
+
+static inline void disable_nat_bits(struct f2fs_sb_info *sbi, bool lock)
+{
+	unsigned long flags;
+
+	set_sbi_flag(sbi, SBI_NEED_FSCK);
+
+	if (lock)
+		spin_lock_irqsave(&sbi->cp_lock, flags);
+	__clear_ckpt_flags(F2FS_CKPT(sbi), CP_NAT_BITS_FLAG);
+	kfree(NM_I(sbi)->nat_bits);
+	NM_I(sbi)->nat_bits = NULL;
+	if (lock)
+		spin_unlock_irqrestore(&sbi->cp_lock, flags);
+}
+
+static inline bool enabled_nat_bits(struct f2fs_sb_info *sbi,
+					struct cp_control *cpc)
+{
+	bool set = is_set_ckpt_flags(sbi, CP_NAT_BITS_FLAG);
+
+	return (cpc) ? (cpc->reason & CP_UMOUNT) && set : set;
+}
+
+static inline void f2fs_lock_op(struct f2fs_sb_info *sbi)
+{
+	down_read(&sbi->cp_rwsem);
+}
+
+static inline int f2fs_trylock_op(struct f2fs_sb_info *sbi)
+{
+	return down_read_trylock(&sbi->cp_rwsem);
+}
+
+static inline void f2fs_unlock_op(struct f2fs_sb_info *sbi)
+{
+	up_read(&sbi->cp_rwsem);
+}
+
+static inline void f2fs_lock_all(struct f2fs_sb_info *sbi)
+{
+	down_write(&sbi->cp_rwsem);
+}
+
+static inline void f2fs_unlock_all(struct f2fs_sb_info *sbi)
+{
+	up_write(&sbi->cp_rwsem);
+}
+
+static inline int __get_cp_reason(struct f2fs_sb_info *sbi)
+{
+	int reason = CP_SYNC;
+
+	if (test_opt(sbi, FASTBOOT))
+		reason = CP_FASTBOOT;
+	if (is_sbi_flag_set(sbi, SBI_IS_CLOSE))
+		reason = CP_UMOUNT;
+	return reason;
+}
+
+static inline bool __remain_node_summaries(int reason)
+{
+	return (reason & (CP_UMOUNT | CP_FASTBOOT));
+}
+
+static inline bool __exist_node_summaries(struct f2fs_sb_info *sbi)
+{
+	return (is_set_ckpt_flags(sbi, CP_UMOUNT_FLAG) ||
+			is_set_ckpt_flags(sbi, CP_FASTBOOT_FLAG));
+}
+
+/*
+ * Check whether the inode has blocks or not
+ */
+static inline int F2FS_HAS_BLOCKS(struct inode *inode)
+{
+	block_t xattr_block = F2FS_I(inode)->i_xattr_nid ? 1 : 0;
+
+	return (inode->i_blocks >> F2FS_LOG_SECTORS_PER_BLOCK) > xattr_block;
+}
+
+static inline bool f2fs_has_xattr_block(unsigned int ofs)
+{
+	return ofs == XATTR_NODE_OFFSET;
+}
+
+static inline bool __allow_reserved_blocks(struct f2fs_sb_info *sbi,
+					struct inode *inode, bool cap)
+{
+	if (!inode)
+		return true;
+	if (!test_opt(sbi, RESERVE_ROOT))
+		return false;
+	if (IS_NOQUOTA(inode))
+		return true;
+	if (uid_eq(F2FS_OPTION(sbi).s_resuid, current_fsuid()))
+		return true;
+	if (!gid_eq(F2FS_OPTION(sbi).s_resgid, GLOBAL_ROOT_GID) &&
+					in_group_p(F2FS_OPTION(sbi).s_resgid))
+		return true;
+	if (cap && capable(CAP_SYS_RESOURCE))
+		return true;
+	return false;
+}
+
+static inline void f2fs_i_blocks_write(struct inode *, block_t, bool, bool);
+static inline int inc_valid_block_count(struct f2fs_sb_info *sbi,
+				 struct inode *inode, blkcnt_t *count)
+{
+	blkcnt_t diff = 0, release = 0;
+	block_t avail_user_block_count;
+	int ret;
+
+	ret = dquot_reserve_block(inode, *count);
+	if (ret)
+		return ret;
+
+#ifdef CONFIG_F2FS_FAULT_INJECTION
+	if (time_to_inject(sbi, FAULT_BLOCK)) {
+		f2fs_show_injection_info(FAULT_BLOCK);
+		release = *count;
+		goto enospc;
+	}
+#endif
+	/*
+	 * let's increase this in prior to actual block count change in order
+	 * for f2fs_sync_file to avoid data races when deciding checkpoint.
+	 */
+	percpu_counter_add(&sbi->alloc_valid_block_count, (*count));
+
+	spin_lock(&sbi->stat_lock);
+	sbi->total_valid_block_count += (block_t)(*count);
+	avail_user_block_count = sbi->user_block_count -
+					sbi->current_reserved_blocks;
+
+	if (!__allow_reserved_blocks(sbi, inode, true))
+		avail_user_block_count -= F2FS_OPTION(sbi).root_reserved_blocks;
+
+	if (unlikely(sbi->total_valid_block_count > avail_user_block_count)) {
+		diff = sbi->total_valid_block_count - avail_user_block_count;
+		if (diff > *count)
+			diff = *count;
+		*count -= diff;
+		release = diff;
+		sbi->total_valid_block_count -= diff;
+		if (!*count) {
+			spin_unlock(&sbi->stat_lock);
+			percpu_counter_sub(&sbi->alloc_valid_block_count, diff);
+			goto enospc;
+		}
+	}
+	spin_unlock(&sbi->stat_lock);
+
+	if (unlikely(release))
+		dquot_release_reservation_block(inode, release);
+	f2fs_i_blocks_write(inode, *count, true, true);
+	return 0;
+
+enospc:
+	dquot_release_reservation_block(inode, release);
+	return -ENOSPC;
+}
+
+void f2fs_msg(struct super_block *sb, const char *level, const char *fmt, ...);
+static inline void dec_valid_block_count(struct f2fs_sb_info *sbi,
+						struct inode *inode,
+						block_t count)
+{
+	blkcnt_t sectors = count << F2FS_LOG_SECTORS_PER_BLOCK;
+
+	spin_lock(&sbi->stat_lock);
+	f2fs_bug_on(sbi, sbi->total_valid_block_count < (block_t) count);
+	sbi->total_valid_block_count -= (block_t)count;
+	if (sbi->reserved_blocks &&
+		sbi->current_reserved_blocks < sbi->reserved_blocks)
+		sbi->current_reserved_blocks = min(sbi->reserved_blocks,
+					sbi->current_reserved_blocks + count);
+	spin_unlock(&sbi->stat_lock);
+	if (unlikely(inode->i_blocks < sectors)) {
+		f2fs_msg(sbi->sb, KERN_WARNING,
+			"Inconsistent i_blocks, ino:%lu, iblocks:%llu, sectors:%llu",
+			inode->i_ino,
+			(unsigned long long)inode->i_blocks,
+			(unsigned long long)sectors);
+		set_sbi_flag(sbi, SBI_NEED_FSCK);
+		return;
+	}
+	f2fs_i_blocks_write(inode, count, false, true);
+}
+
+static inline void inc_page_count(struct f2fs_sb_info *sbi, int count_type)
+{
+	atomic_inc(&sbi->nr_pages[count_type]);
+
+	if (count_type == F2FS_DIRTY_DATA || count_type == F2FS_INMEM_PAGES ||
+		count_type == F2FS_WB_CP_DATA || count_type == F2FS_WB_DATA)
+		return;
+
+	set_sbi_flag(sbi, SBI_IS_DIRTY);
+}
+
+static inline void inode_inc_dirty_pages(struct inode *inode)
+{
+	atomic_inc(&F2FS_I(inode)->dirty_pages);
+	inc_page_count(F2FS_I_SB(inode), S_ISDIR(inode->i_mode) ?
+				F2FS_DIRTY_DENTS : F2FS_DIRTY_DATA);
+	if (IS_NOQUOTA(inode))
+		inc_page_count(F2FS_I_SB(inode), F2FS_DIRTY_QDATA);
+}
+
+static inline void dec_page_count(struct f2fs_sb_info *sbi, int count_type)
+{
+	atomic_dec(&sbi->nr_pages[count_type]);
+}
+
+static inline void inode_dec_dirty_pages(struct inode *inode)
+{
+	if (!S_ISDIR(inode->i_mode) && !S_ISREG(inode->i_mode) &&
+			!S_ISLNK(inode->i_mode))
+		return;
+
+	atomic_dec(&F2FS_I(inode)->dirty_pages);
+	dec_page_count(F2FS_I_SB(inode), S_ISDIR(inode->i_mode) ?
+				F2FS_DIRTY_DENTS : F2FS_DIRTY_DATA);
+	if (IS_NOQUOTA(inode))
+		dec_page_count(F2FS_I_SB(inode), F2FS_DIRTY_QDATA);
+}
+
+static inline s64 get_pages(struct f2fs_sb_info *sbi, int count_type)
+{
+	return atomic_read(&sbi->nr_pages[count_type]);
+}
+
+static inline int get_dirty_pages(struct inode *inode)
+{
+	return atomic_read(&F2FS_I(inode)->dirty_pages);
+}
+
+static inline int get_blocktype_secs(struct f2fs_sb_info *sbi, int block_type)
+{
+	unsigned int pages_per_sec = sbi->segs_per_sec * sbi->blocks_per_seg;
+	unsigned int segs = (get_pages(sbi, block_type) + pages_per_sec - 1) >>
+						sbi->log_blocks_per_seg;
+
+	return segs / sbi->segs_per_sec;
+}
+
+static inline block_t valid_user_blocks(struct f2fs_sb_info *sbi)
+{
+	return sbi->total_valid_block_count;
+}
+
+static inline block_t discard_blocks(struct f2fs_sb_info *sbi)
+{
+	return sbi->discard_blks;
+}
+
+static inline unsigned long __bitmap_size(struct f2fs_sb_info *sbi, int flag)
+{
+	struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
+
+	/* return NAT or SIT bitmap */
+	if (flag == NAT_BITMAP)
+		return le32_to_cpu(ckpt->nat_ver_bitmap_bytesize);
+	else if (flag == SIT_BITMAP)
+		return le32_to_cpu(ckpt->sit_ver_bitmap_bytesize);
+
+	return 0;
+}
+
+static inline block_t __cp_payload(struct f2fs_sb_info *sbi)
+{
+	return le32_to_cpu(F2FS_RAW_SUPER(sbi)->cp_payload);
+}
+
+static inline void *__bitmap_ptr(struct f2fs_sb_info *sbi, int flag)
+{
+	struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
+	int offset;
+
+	if (is_set_ckpt_flags(sbi, CP_LARGE_NAT_BITMAP_FLAG)) {
+		offset = (flag == SIT_BITMAP) ?
+			le32_to_cpu(ckpt->nat_ver_bitmap_bytesize) : 0;
+		return &ckpt->sit_nat_version_bitmap + offset;
+	}
+
+	if (__cp_payload(sbi) > 0) {
+		if (flag == NAT_BITMAP)
+			return &ckpt->sit_nat_version_bitmap;
+		else
+			return (unsigned char *)ckpt + F2FS_BLKSIZE;
+	} else {
+		offset = (flag == NAT_BITMAP) ?
+			le32_to_cpu(ckpt->sit_ver_bitmap_bytesize) : 0;
+		return &ckpt->sit_nat_version_bitmap + offset;
+	}
+}
+
+static inline block_t __start_cp_addr(struct f2fs_sb_info *sbi)
+{
+	block_t start_addr = le32_to_cpu(F2FS_RAW_SUPER(sbi)->cp_blkaddr);
+
+	if (sbi->cur_cp_pack == 2)
+		start_addr += sbi->blocks_per_seg;
+	return start_addr;
+}
+
+static inline block_t __start_cp_next_addr(struct f2fs_sb_info *sbi)
+{
+	block_t start_addr = le32_to_cpu(F2FS_RAW_SUPER(sbi)->cp_blkaddr);
+
+	if (sbi->cur_cp_pack == 1)
+		start_addr += sbi->blocks_per_seg;
+	return start_addr;
+}
+
+static inline void __set_cp_next_pack(struct f2fs_sb_info *sbi)
+{
+	sbi->cur_cp_pack = (sbi->cur_cp_pack == 1) ? 2 : 1;
+}
+
+static inline block_t __start_sum_addr(struct f2fs_sb_info *sbi)
+{
+	return le32_to_cpu(F2FS_CKPT(sbi)->cp_pack_start_sum);
+}
+
+static inline int inc_valid_node_count(struct f2fs_sb_info *sbi,
+					struct inode *inode, bool is_inode)
+{
+	block_t	valid_block_count;
+	unsigned int valid_node_count;
+	bool quota = inode && !is_inode;
+
+	if (quota) {
+		int ret = dquot_reserve_block(inode, 1);
+		if (ret)
+			return ret;
+	}
+
+#ifdef CONFIG_F2FS_FAULT_INJECTION
+	if (time_to_inject(sbi, FAULT_BLOCK)) {
+		f2fs_show_injection_info(FAULT_BLOCK);
+		goto enospc;
+	}
+#endif
+
+	spin_lock(&sbi->stat_lock);
+
+	valid_block_count = sbi->total_valid_block_count +
+					sbi->current_reserved_blocks + 1;
+
+	if (!__allow_reserved_blocks(sbi, inode, false))
+		valid_block_count += F2FS_OPTION(sbi).root_reserved_blocks;
+
+	if (unlikely(valid_block_count > sbi->user_block_count)) {
+		spin_unlock(&sbi->stat_lock);
+		goto enospc;
+	}
+
+	valid_node_count = sbi->total_valid_node_count + 1;
+	if (unlikely(valid_node_count > sbi->total_node_count)) {
+		spin_unlock(&sbi->stat_lock);
+		goto enospc;
+	}
+
+	sbi->total_valid_node_count++;
+	sbi->total_valid_block_count++;
+	spin_unlock(&sbi->stat_lock);
+
+	if (inode) {
+		if (is_inode)
+			f2fs_mark_inode_dirty_sync(inode, true);
+		else
+			f2fs_i_blocks_write(inode, 1, true, true);
+	}
+
+	percpu_counter_inc(&sbi->alloc_valid_block_count);
+	return 0;
+
+enospc:
+	if (quota)
+		dquot_release_reservation_block(inode, 1);
+	return -ENOSPC;
+}
+
+static inline void dec_valid_node_count(struct f2fs_sb_info *sbi,
+					struct inode *inode, bool is_inode)
+{
+	spin_lock(&sbi->stat_lock);
+
+	f2fs_bug_on(sbi, !sbi->total_valid_block_count);
+	f2fs_bug_on(sbi, !sbi->total_valid_node_count);
+	f2fs_bug_on(sbi, !is_inode && !inode->i_blocks);
+
+	sbi->total_valid_node_count--;
+	sbi->total_valid_block_count--;
+	if (sbi->reserved_blocks &&
+		sbi->current_reserved_blocks < sbi->reserved_blocks)
+		sbi->current_reserved_blocks++;
+
+	spin_unlock(&sbi->stat_lock);
+
+	if (!is_inode)
+		f2fs_i_blocks_write(inode, 1, false, true);
+}
+
+static inline unsigned int valid_node_count(struct f2fs_sb_info *sbi)
+{
+	return sbi->total_valid_node_count;
+}
+
+static inline void inc_valid_inode_count(struct f2fs_sb_info *sbi)
+{
+	percpu_counter_inc(&sbi->total_valid_inode_count);
+}
+
+static inline void dec_valid_inode_count(struct f2fs_sb_info *sbi)
+{
+	percpu_counter_dec(&sbi->total_valid_inode_count);
+}
+
+static inline s64 valid_inode_count(struct f2fs_sb_info *sbi)
+{
+	return percpu_counter_sum_positive(&sbi->total_valid_inode_count);
+}
+
+static inline struct page *f2fs_grab_cache_page(struct address_space *mapping,
+						pgoff_t index, bool for_write)
+{
+#ifdef CONFIG_F2FS_FAULT_INJECTION
+	struct page *page;
+
+	if (!for_write)
+		page = find_get_page_flags(mapping, index,
+						FGP_LOCK | FGP_ACCESSED);
+	else
+		page = find_lock_page(mapping, index);
+	if (page)
+		return page;
+
+	if (time_to_inject(F2FS_M_SB(mapping), FAULT_PAGE_ALLOC)) {
+		f2fs_show_injection_info(FAULT_PAGE_ALLOC);
+		return NULL;
+	}
+#endif
+	if (!for_write)
+		return grab_cache_page(mapping, index);
+	return grab_cache_page_write_begin(mapping, index, AOP_FLAG_NOFS);
+}
+
+static inline struct page *f2fs_pagecache_get_page(
+				struct address_space *mapping, pgoff_t index,
+				int fgp_flags, gfp_t gfp_mask)
+{
+#ifdef CONFIG_F2FS_FAULT_INJECTION
+	if (time_to_inject(F2FS_M_SB(mapping), FAULT_PAGE_GET)) {
+		f2fs_show_injection_info(FAULT_PAGE_GET);
+		return NULL;
+	}
+#endif
+	return pagecache_get_page(mapping, index, fgp_flags, gfp_mask);
+}
+
+static inline void f2fs_copy_page(struct page *src, struct page *dst)
+{
+	char *src_kaddr = kmap(src);
+	char *dst_kaddr = kmap(dst);
+
+	memcpy(dst_kaddr, src_kaddr, PAGE_SIZE);
+	kunmap(dst);
+	kunmap(src);
+}
+
+static inline void f2fs_put_page(struct page *page, int unlock)
+{
+	if (!page)
+		return;
+
+	if (unlock) {
+		f2fs_bug_on(F2FS_P_SB(page), !PageLocked(page));
+		unlock_page(page);
+	}
+	put_page(page);
+}
+
+static inline void f2fs_put_dnode(struct dnode_of_data *dn)
+{
+	if (dn->node_page)
+		f2fs_put_page(dn->node_page, 1);
+	if (dn->inode_page && dn->node_page != dn->inode_page)
+		f2fs_put_page(dn->inode_page, 0);
+	dn->node_page = NULL;
+	dn->inode_page = NULL;
+}
+
+static inline struct kmem_cache *f2fs_kmem_cache_create(const char *name,
+					size_t size)
+{
+	return kmem_cache_create(name, size, 0, SLAB_RECLAIM_ACCOUNT, NULL);
+}
+
+static inline void *f2fs_kmem_cache_alloc(struct kmem_cache *cachep,
+						gfp_t flags)
+{
+	void *entry;
+
+	entry = kmem_cache_alloc(cachep, flags);
+	if (!entry)
+		entry = kmem_cache_alloc(cachep, flags | __GFP_NOFAIL);
+	return entry;
+}
+
+static inline struct bio *f2fs_bio_alloc(struct f2fs_sb_info *sbi,
+						int npages, bool no_fail)
+{
+	struct bio *bio;
+
+	if (no_fail) {
+		/* No failure on bio allocation */
+		bio = bio_alloc(GFP_NOIO, npages);
+		if (!bio)
+			bio = bio_alloc(GFP_NOIO | __GFP_NOFAIL, npages);
+		return bio;
+	}
+#ifdef CONFIG_F2FS_FAULT_INJECTION
+	if (time_to_inject(sbi, FAULT_ALLOC_BIO)) {
+		f2fs_show_injection_info(FAULT_ALLOC_BIO);
+		return NULL;
+	}
+#endif
+	return bio_alloc(GFP_KERNEL, npages);
+}
+
+static inline void f2fs_radix_tree_insert(struct radix_tree_root *root,
+				unsigned long index, void *item)
+{
+	while (radix_tree_insert(root, index, item))
+		cond_resched();
+}
+
+#define RAW_IS_INODE(p)	((p)->footer.nid == (p)->footer.ino)
+
+static inline bool IS_INODE(struct page *page)
+{
+	struct f2fs_node *p = F2FS_NODE(page);
+
+	return RAW_IS_INODE(p);
+}
+
+static inline int offset_in_addr(struct f2fs_inode *i)
+{
+	return (i->i_inline & F2FS_EXTRA_ATTR) ?
+			(le16_to_cpu(i->i_extra_isize) / sizeof(__le32)) : 0;
+}
+
+static inline __le32 *blkaddr_in_node(struct f2fs_node *node)
+{
+	return RAW_IS_INODE(node) ? node->i.i_addr : node->dn.addr;
+}
+
+static inline int f2fs_has_extra_attr(struct inode *inode);
+static inline block_t datablock_addr(struct inode *inode,
+			struct page *node_page, unsigned int offset)
+{
+	struct f2fs_node *raw_node;
+	__le32 *addr_array;
+	int base = 0;
+	bool is_inode = IS_INODE(node_page);
+
+	raw_node = F2FS_NODE(node_page);
+
+	/* from GC path only */
+	if (is_inode) {
+		if (!inode)
+			base = offset_in_addr(&raw_node->i);
+		else if (f2fs_has_extra_attr(inode))
+			base = get_extra_isize(inode);
+	}
+
+	addr_array = blkaddr_in_node(raw_node);
+	return le32_to_cpu(addr_array[base + offset]);
+}
+
+static inline int f2fs_test_bit(unsigned int nr, char *addr)
+{
+	int mask;
+
+	addr += (nr >> 3);
+	mask = 1 << (7 - (nr & 0x07));
+	return mask & *addr;
+}
+
+static inline void f2fs_set_bit(unsigned int nr, char *addr)
+{
+	int mask;
+
+	addr += (nr >> 3);
+	mask = 1 << (7 - (nr & 0x07));
+	*addr |= mask;
+}
+
+static inline void f2fs_clear_bit(unsigned int nr, char *addr)
+{
+	int mask;
+
+	addr += (nr >> 3);
+	mask = 1 << (7 - (nr & 0x07));
+	*addr &= ~mask;
+}
+
+static inline int f2fs_test_and_set_bit(unsigned int nr, char *addr)
+{
+	int mask;
+	int ret;
+
+	addr += (nr >> 3);
+	mask = 1 << (7 - (nr & 0x07));
+	ret = mask & *addr;
+	*addr |= mask;
+	return ret;
+}
+
+static inline int f2fs_test_and_clear_bit(unsigned int nr, char *addr)
+{
+	int mask;
+	int ret;
+
+	addr += (nr >> 3);
+	mask = 1 << (7 - (nr & 0x07));
+	ret = mask & *addr;
+	*addr &= ~mask;
+	return ret;
+}
+
+static inline void f2fs_change_bit(unsigned int nr, char *addr)
+{
+	int mask;
+
+	addr += (nr >> 3);
+	mask = 1 << (7 - (nr & 0x07));
+	*addr ^= mask;
+}
+
+#define F2FS_REG_FLMASK		(~(FS_DIRSYNC_FL | FS_TOPDIR_FL))
+#define F2FS_OTHER_FLMASK	(FS_NODUMP_FL | FS_NOATIME_FL)
+#define F2FS_FL_INHERITED	(FS_PROJINHERIT_FL)
+
+static inline __u32 f2fs_mask_flags(umode_t mode, __u32 flags)
+{
+	if (S_ISDIR(mode))
+		return flags;
+	else if (S_ISREG(mode))
+		return flags & F2FS_REG_FLMASK;
+	else
+		return flags & F2FS_OTHER_FLMASK;
+}
+
+/* used for f2fs_inode_info->flags */
+enum {
+	FI_NEW_INODE,		/* indicate newly allocated inode */
+	FI_DIRTY_INODE,		/* indicate inode is dirty or not */
+	FI_AUTO_RECOVER,	/* indicate inode is recoverable */
+	FI_DIRTY_DIR,		/* indicate directory has dirty pages */
+	FI_INC_LINK,		/* need to increment i_nlink */
+	FI_ACL_MODE,		/* indicate acl mode */
+	FI_NO_ALLOC,		/* should not allocate any blocks */
+	FI_FREE_NID,		/* free allocated nide */
+	FI_NO_EXTENT,		/* not to use the extent cache */
+	FI_INLINE_XATTR,	/* used for inline xattr */
+	FI_INLINE_DATA,		/* used for inline data*/
+	FI_INLINE_DENTRY,	/* used for inline dentry */
+	FI_APPEND_WRITE,	/* inode has appended data */
+	FI_UPDATE_WRITE,	/* inode has in-place-update data */
+	FI_NEED_IPU,		/* used for ipu per file */
+	FI_ATOMIC_FILE,		/* indicate atomic file */
+	FI_ATOMIC_COMMIT,	/* indicate the state of atomical committing */
+	FI_VOLATILE_FILE,	/* indicate volatile file */
+	FI_FIRST_BLOCK_WRITTEN,	/* indicate #0 data block was written */
+	FI_DROP_CACHE,		/* drop dirty page cache */
+	FI_DATA_EXIST,		/* indicate data exists */
+	FI_INLINE_DOTS,		/* indicate inline dot dentries */
+	FI_DO_DEFRAG,		/* indicate defragment is running */
+	FI_DIRTY_FILE,		/* indicate regular/symlink has dirty pages */
+	FI_NO_PREALLOC,		/* indicate skipped preallocated blocks */
+	FI_HOT_DATA,		/* indicate file is hot */
+	FI_EXTRA_ATTR,		/* indicate file has extra attribute */
+	FI_PROJ_INHERIT,	/* indicate file inherits projectid */
+	FI_PIN_FILE,		/* indicate file should not be gced */
+};
+
+static inline void __mark_inode_dirty_flag(struct inode *inode,
+						int flag, bool set)
+{
+	switch (flag) {
+	case FI_INLINE_XATTR:
+	case FI_INLINE_DATA:
+	case FI_INLINE_DENTRY:
+	case FI_NEW_INODE:
+		if (set)
+			return;
+	case FI_DATA_EXIST:
+	case FI_INLINE_DOTS:
+	case FI_PIN_FILE:
+		f2fs_mark_inode_dirty_sync(inode, true);
+	}
+}
+
+static inline void set_inode_flag(struct inode *inode, int flag)
+{
+	if (!test_bit(flag, &F2FS_I(inode)->flags))
+		set_bit(flag, &F2FS_I(inode)->flags);
+	__mark_inode_dirty_flag(inode, flag, true);
+}
+
+static inline int is_inode_flag_set(struct inode *inode, int flag)
+{
+	return test_bit(flag, &F2FS_I(inode)->flags);
+}
+
+static inline void clear_inode_flag(struct inode *inode, int flag)
+{
+	if (test_bit(flag, &F2FS_I(inode)->flags))
+		clear_bit(flag, &F2FS_I(inode)->flags);
+	__mark_inode_dirty_flag(inode, flag, false);
+}
+
+static inline void set_acl_inode(struct inode *inode, umode_t mode)
+{
+	F2FS_I(inode)->i_acl_mode = mode;
+	set_inode_flag(inode, FI_ACL_MODE);
+	f2fs_mark_inode_dirty_sync(inode, false);
+}
+
+static inline void f2fs_i_links_write(struct inode *inode, bool inc)
+{
+	if (inc)
+		inc_nlink(inode);
+	else
+		drop_nlink(inode);
+	f2fs_mark_inode_dirty_sync(inode, true);
+}
+
+static inline void f2fs_i_blocks_write(struct inode *inode,
+					block_t diff, bool add, bool claim)
+{
+	bool clean = !is_inode_flag_set(inode, FI_DIRTY_INODE);
+	bool recover = is_inode_flag_set(inode, FI_AUTO_RECOVER);
+
+	/* add = 1, claim = 1 should be dquot_reserve_block in pair */
+	if (add) {
+		if (claim)
+			dquot_claim_block(inode, diff);
+		else
+			dquot_alloc_block_nofail(inode, diff);
+	} else {
+		dquot_free_block(inode, diff);
+	}
+
+	f2fs_mark_inode_dirty_sync(inode, true);
+	if (clean || recover)
+		set_inode_flag(inode, FI_AUTO_RECOVER);
+}
+
+static inline void f2fs_i_size_write(struct inode *inode, loff_t i_size)
+{
+	bool clean = !is_inode_flag_set(inode, FI_DIRTY_INODE);
+	bool recover = is_inode_flag_set(inode, FI_AUTO_RECOVER);
+
+	if (i_size_read(inode) == i_size)
+		return;
+
+	i_size_write(inode, i_size);
+	f2fs_mark_inode_dirty_sync(inode, true);
+	if (clean || recover)
+		set_inode_flag(inode, FI_AUTO_RECOVER);
+}
+
+static inline void f2fs_i_depth_write(struct inode *inode, unsigned int depth)
+{
+	F2FS_I(inode)->i_current_depth = depth;
+	f2fs_mark_inode_dirty_sync(inode, true);
+}
+
+static inline void f2fs_i_gc_failures_write(struct inode *inode,
+					unsigned int count)
+{
+	F2FS_I(inode)->i_gc_failures = count;
+	f2fs_mark_inode_dirty_sync(inode, true);
+}
+
+static inline void f2fs_i_xnid_write(struct inode *inode, nid_t xnid)
+{
+	F2FS_I(inode)->i_xattr_nid = xnid;
+	f2fs_mark_inode_dirty_sync(inode, true);
+}
+
+static inline void f2fs_i_pino_write(struct inode *inode, nid_t pino)
+{
+	F2FS_I(inode)->i_pino = pino;
+	f2fs_mark_inode_dirty_sync(inode, true);
+}
+
+static inline void get_inline_info(struct inode *inode, struct f2fs_inode *ri)
+{
+	struct f2fs_inode_info *fi = F2FS_I(inode);
+
+	if (ri->i_inline & F2FS_INLINE_XATTR)
+		set_bit(FI_INLINE_XATTR, &fi->flags);
+	if (ri->i_inline & F2FS_INLINE_DATA)
+		set_bit(FI_INLINE_DATA, &fi->flags);
+	if (ri->i_inline & F2FS_INLINE_DENTRY)
+		set_bit(FI_INLINE_DENTRY, &fi->flags);
+	if (ri->i_inline & F2FS_DATA_EXIST)
+		set_bit(FI_DATA_EXIST, &fi->flags);
+	if (ri->i_inline & F2FS_INLINE_DOTS)
+		set_bit(FI_INLINE_DOTS, &fi->flags);
+	if (ri->i_inline & F2FS_EXTRA_ATTR)
+		set_bit(FI_EXTRA_ATTR, &fi->flags);
+	if (ri->i_inline & F2FS_PIN_FILE)
+		set_bit(FI_PIN_FILE, &fi->flags);
+}
+
+static inline void set_raw_inline(struct inode *inode, struct f2fs_inode *ri)
+{
+	ri->i_inline = 0;
+
+	if (is_inode_flag_set(inode, FI_INLINE_XATTR))
+		ri->i_inline |= F2FS_INLINE_XATTR;
+	if (is_inode_flag_set(inode, FI_INLINE_DATA))
+		ri->i_inline |= F2FS_INLINE_DATA;
+	if (is_inode_flag_set(inode, FI_INLINE_DENTRY))
+		ri->i_inline |= F2FS_INLINE_DENTRY;
+	if (is_inode_flag_set(inode, FI_DATA_EXIST))
+		ri->i_inline |= F2FS_DATA_EXIST;
+	if (is_inode_flag_set(inode, FI_INLINE_DOTS))
+		ri->i_inline |= F2FS_INLINE_DOTS;
+	if (is_inode_flag_set(inode, FI_EXTRA_ATTR))
+		ri->i_inline |= F2FS_EXTRA_ATTR;
+	if (is_inode_flag_set(inode, FI_PIN_FILE))
+		ri->i_inline |= F2FS_PIN_FILE;
+}
+
+static inline int f2fs_has_extra_attr(struct inode *inode)
+{
+	return is_inode_flag_set(inode, FI_EXTRA_ATTR);
+}
+
+static inline int f2fs_has_inline_xattr(struct inode *inode)
+{
+	return is_inode_flag_set(inode, FI_INLINE_XATTR);
+}
+
+static inline unsigned int addrs_per_inode(struct inode *inode)
+{
+	return CUR_ADDRS_PER_INODE(inode) - get_inline_xattr_addrs(inode);
+}
+
+static inline void *inline_xattr_addr(struct inode *inode, struct page *page)
+{
+	struct f2fs_inode *ri = F2FS_INODE(page);
+
+	return (void *)&(ri->i_addr[DEF_ADDRS_PER_INODE -
+					get_inline_xattr_addrs(inode)]);
+}
+
+static inline int inline_xattr_size(struct inode *inode)
+{
+	return get_inline_xattr_addrs(inode) * sizeof(__le32);
+}
+
+static inline int f2fs_has_inline_data(struct inode *inode)
+{
+	return is_inode_flag_set(inode, FI_INLINE_DATA);
+}
+
+static inline int f2fs_exist_data(struct inode *inode)
+{
+	return is_inode_flag_set(inode, FI_DATA_EXIST);
+}
+
+static inline int f2fs_has_inline_dots(struct inode *inode)
+{
+	return is_inode_flag_set(inode, FI_INLINE_DOTS);
+}
+
+static inline bool f2fs_is_pinned_file(struct inode *inode)
+{
+	return is_inode_flag_set(inode, FI_PIN_FILE);
+}
+
+static inline bool f2fs_is_atomic_file(struct inode *inode)
+{
+	return is_inode_flag_set(inode, FI_ATOMIC_FILE);
+}
+
+static inline bool f2fs_is_commit_atomic_write(struct inode *inode)
+{
+	return is_inode_flag_set(inode, FI_ATOMIC_COMMIT);
+}
+
+static inline bool f2fs_is_volatile_file(struct inode *inode)
+{
+	return is_inode_flag_set(inode, FI_VOLATILE_FILE);
+}
+
+static inline bool f2fs_is_first_block_written(struct inode *inode)
+{
+	return is_inode_flag_set(inode, FI_FIRST_BLOCK_WRITTEN);
+}
+
+static inline bool f2fs_is_drop_cache(struct inode *inode)
+{
+	return is_inode_flag_set(inode, FI_DROP_CACHE);
+}
+
+static inline void *inline_data_addr(struct inode *inode, struct page *page)
+{
+	struct f2fs_inode *ri = F2FS_INODE(page);
+	int extra_size = get_extra_isize(inode);
+
+	return (void *)&(ri->i_addr[extra_size + DEF_INLINE_RESERVED_SIZE]);
+}
+
+static inline int f2fs_has_inline_dentry(struct inode *inode)
+{
+	return is_inode_flag_set(inode, FI_INLINE_DENTRY);
+}
+
+static inline int is_file(struct inode *inode, int type)
+{
+	return F2FS_I(inode)->i_advise & type;
+}
+
+static inline void set_file(struct inode *inode, int type)
+{
+	F2FS_I(inode)->i_advise |= type;
+	f2fs_mark_inode_dirty_sync(inode, true);
+}
+
+static inline void clear_file(struct inode *inode, int type)
+{
+	F2FS_I(inode)->i_advise &= ~type;
+	f2fs_mark_inode_dirty_sync(inode, true);
+}
+
+static inline bool f2fs_skip_inode_update(struct inode *inode, int dsync)
+{
+	bool ret;
+
+	if (dsync) {
+		struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+
+		spin_lock(&sbi->inode_lock[DIRTY_META]);
+		ret = list_empty(&F2FS_I(inode)->gdirty_list);
+		spin_unlock(&sbi->inode_lock[DIRTY_META]);
+		return ret;
+	}
+	if (!is_inode_flag_set(inode, FI_AUTO_RECOVER) ||
+			file_keep_isize(inode) ||
+			i_size_read(inode) & ~PAGE_MASK)
+		return false;
+
+	if (!timespec_equal(F2FS_I(inode)->i_disk_time, &inode->i_atime))
+		return false;
+	if (!timespec_equal(F2FS_I(inode)->i_disk_time + 1, &inode->i_ctime))
+		return false;
+	if (!timespec_equal(F2FS_I(inode)->i_disk_time + 2, &inode->i_mtime))
+		return false;
+	if (!timespec_equal(F2FS_I(inode)->i_disk_time + 3,
+						&F2FS_I(inode)->i_crtime))
+		return false;
+
+	down_read(&F2FS_I(inode)->i_sem);
+	ret = F2FS_I(inode)->last_disk_size == i_size_read(inode);
+	up_read(&F2FS_I(inode)->i_sem);
+
+	return ret;
+}
+
+static inline bool f2fs_readonly(struct super_block *sb)
+{
+	return sb_rdonly(sb);
+}
+
+static inline bool f2fs_cp_error(struct f2fs_sb_info *sbi)
+{
+	return is_set_ckpt_flags(sbi, CP_ERROR_FLAG);
+}
+
+static inline bool is_dot_dotdot(const struct qstr *str)
+{
+	if (str->len == 1 && str->name[0] == '.')
+		return true;
+
+	if (str->len == 2 && str->name[0] == '.' && str->name[1] == '.')
+		return true;
+
+	return false;
+}
+
+static inline bool f2fs_may_extent_tree(struct inode *inode)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+
+	if (!test_opt(sbi, EXTENT_CACHE) ||
+			is_inode_flag_set(inode, FI_NO_EXTENT))
+		return false;
+
+	/*
+	 * for recovered files during mount do not create extents
+	 * if shrinker is not registered.
+	 */
+	if (list_empty(&sbi->s_list))
+		return false;
+
+	return S_ISREG(inode->i_mode);
+}
+
+static inline void *f2fs_kmalloc(struct f2fs_sb_info *sbi,
+					size_t size, gfp_t flags)
+{
+#ifdef CONFIG_F2FS_FAULT_INJECTION
+	if (time_to_inject(sbi, FAULT_KMALLOC)) {
+		f2fs_show_injection_info(FAULT_KMALLOC);
+		return NULL;
+	}
+#endif
+	return kmalloc(size, flags);
+}
+
+static inline void *f2fs_kzalloc(struct f2fs_sb_info *sbi,
+					size_t size, gfp_t flags)
+{
+	return f2fs_kmalloc(sbi, size, flags | __GFP_ZERO);
+}
+
+static inline void *f2fs_kvmalloc(struct f2fs_sb_info *sbi,
+					size_t size, gfp_t flags)
+{
+#ifdef CONFIG_F2FS_FAULT_INJECTION
+	if (time_to_inject(sbi, FAULT_KVMALLOC)) {
+		f2fs_show_injection_info(FAULT_KVMALLOC);
+		return NULL;
+	}
+#endif
+	return kvmalloc(size, flags);
+}
+
+static inline void *f2fs_kvzalloc(struct f2fs_sb_info *sbi,
+					size_t size, gfp_t flags)
+{
+	return f2fs_kvmalloc(sbi, size, flags | __GFP_ZERO);
+}
+
+static inline int get_extra_isize(struct inode *inode)
+{
+	return F2FS_I(inode)->i_extra_isize / sizeof(__le32);
+}
+
+static inline int get_inline_xattr_addrs(struct inode *inode)
+{
+	return F2FS_I(inode)->i_inline_xattr_size;
+}
+
+#define get_inode_mode(i) \
+	((is_inode_flag_set(i, FI_ACL_MODE)) ? \
+	 (F2FS_I(i)->i_acl_mode) : ((i)->i_mode))
+
+#define F2FS_TOTAL_EXTRA_ATTR_SIZE			\
+	(offsetof(struct f2fs_inode, i_extra_end) -	\
+	offsetof(struct f2fs_inode, i_extra_isize))	\
+
+#define F2FS_OLD_ATTRIBUTE_SIZE	(offsetof(struct f2fs_inode, i_addr))
+#define F2FS_FITS_IN_INODE(f2fs_inode, extra_isize, field)		\
+		((offsetof(typeof(*f2fs_inode), field) +	\
+		sizeof((f2fs_inode)->field))			\
+		<= (F2FS_OLD_ATTRIBUTE_SIZE + extra_isize))	\
+
+static inline void f2fs_reset_iostat(struct f2fs_sb_info *sbi)
+{
+	int i;
+
+	spin_lock(&sbi->iostat_lock);
+	for (i = 0; i < NR_IO_TYPE; i++)
+		sbi->write_iostat[i] = 0;
+	spin_unlock(&sbi->iostat_lock);
+}
+
+static inline void f2fs_update_iostat(struct f2fs_sb_info *sbi,
+			enum iostat_type type, unsigned long long io_bytes)
+{
+	if (!sbi->iostat_enable)
+		return;
+	spin_lock(&sbi->iostat_lock);
+	sbi->write_iostat[type] += io_bytes;
+
+	if (type == APP_WRITE_IO || type == APP_DIRECT_IO)
+		sbi->write_iostat[APP_BUFFERED_IO] =
+			sbi->write_iostat[APP_WRITE_IO] -
+			sbi->write_iostat[APP_DIRECT_IO];
+	spin_unlock(&sbi->iostat_lock);
+}
+
+#define __is_meta_io(fio) (PAGE_TYPE_OF_BIO(fio->type) == META &&	\
+				(!is_read_io(fio->op) || fio->is_meta))
+
+bool f2fs_is_valid_blkaddr(struct f2fs_sb_info *sbi,
+					block_t blkaddr, int type);
+static inline void verify_blkaddr(struct f2fs_sb_info *sbi,
+					block_t blkaddr, int type)
+{
+	if (!f2fs_is_valid_blkaddr(sbi, blkaddr, type)) {
+		f2fs_msg(sbi->sb, KERN_ERR,
+			"invalid blkaddr: %u, type: %d, run fsck to fix.",
+			blkaddr, type);
+		f2fs_bug_on(sbi, 1);
+	}
+}
+
+static inline bool __is_valid_data_blkaddr(block_t blkaddr)
+{
+	if (blkaddr == NEW_ADDR || blkaddr == NULL_ADDR)
+		return false;
+	return true;
+}
+
+static inline bool is_valid_data_blkaddr(struct f2fs_sb_info *sbi,
+						block_t blkaddr)
+{
+	if (!__is_valid_data_blkaddr(blkaddr))
+		return false;
+	verify_blkaddr(sbi, blkaddr, DATA_GENERIC);
+	return true;
+}
+
+/*
+ * file.c
+ */
+int f2fs_sync_file(struct file *file, loff_t start, loff_t end, int datasync);
+void truncate_data_blocks(struct dnode_of_data *dn);
+int truncate_blocks(struct inode *inode, u64 from, bool lock);
+int f2fs_truncate(struct inode *inode);
+int f2fs_getattr(const struct path *path, struct kstat *stat,
+			u32 request_mask, unsigned int flags);
+int f2fs_setattr(struct dentry *dentry, struct iattr *attr);
+int truncate_hole(struct inode *inode, pgoff_t pg_start, pgoff_t pg_end);
+void truncate_data_blocks_range(struct dnode_of_data *dn, int count);
+int f2fs_precache_extents(struct inode *inode);
+long f2fs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg);
+long f2fs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
+int f2fs_pin_file_control(struct inode *inode, bool inc);
+
+/*
+ * inode.c
+ */
+void f2fs_set_inode_flags(struct inode *inode);
+bool f2fs_inode_chksum_verify(struct f2fs_sb_info *sbi, struct page *page);
+void f2fs_inode_chksum_set(struct f2fs_sb_info *sbi, struct page *page);
+struct inode *f2fs_iget(struct super_block *sb, unsigned long ino);
+struct inode *f2fs_iget_retry(struct super_block *sb, unsigned long ino);
+int try_to_free_nats(struct f2fs_sb_info *sbi, int nr_shrink);
+void update_inode(struct inode *inode, struct page *node_page);
+void update_inode_page(struct inode *inode);
+int f2fs_write_inode(struct inode *inode, struct writeback_control *wbc);
+void f2fs_evict_inode(struct inode *inode);
+void handle_failed_inode(struct inode *inode);
+
+/*
+ * namei.c
+ */
+int update_extension_list(struct f2fs_sb_info *sbi, const char *name,
+							bool hot, bool set);
+struct dentry *f2fs_get_parent(struct dentry *child);
+
+/*
+ * dir.c
+ */
+void set_de_type(struct f2fs_dir_entry *de, umode_t mode);
+unsigned char get_de_type(struct f2fs_dir_entry *de);
+struct f2fs_dir_entry *find_target_dentry(struct fscrypt_name *fname,
+			f2fs_hash_t namehash, int *max_slots,
+			struct f2fs_dentry_ptr *d);
+int f2fs_fill_dentries(struct dir_context *ctx, struct f2fs_dentry_ptr *d,
+			unsigned int start_pos, struct fscrypt_str *fstr);
+void do_make_empty_dir(struct inode *inode, struct inode *parent,
+			struct f2fs_dentry_ptr *d);
+struct page *init_inode_metadata(struct inode *inode, struct inode *dir,
+			const struct qstr *new_name,
+			const struct qstr *orig_name, struct page *dpage);
+void update_parent_metadata(struct inode *dir, struct inode *inode,
+			unsigned int current_depth);
+int room_for_filename(const void *bitmap, int slots, int max_slots);
+void f2fs_drop_nlink(struct inode *dir, struct inode *inode);
+struct f2fs_dir_entry *__f2fs_find_entry(struct inode *dir,
+			struct fscrypt_name *fname, struct page **res_page);
+struct f2fs_dir_entry *f2fs_find_entry(struct inode *dir,
+			const struct qstr *child, struct page **res_page);
+struct f2fs_dir_entry *f2fs_parent_dir(struct inode *dir, struct page **p);
+ino_t f2fs_inode_by_name(struct inode *dir, const struct qstr *qstr,
+			struct page **page);
+void f2fs_set_link(struct inode *dir, struct f2fs_dir_entry *de,
+			struct page *page, struct inode *inode);
+void f2fs_update_dentry(nid_t ino, umode_t mode, struct f2fs_dentry_ptr *d,
+			const struct qstr *name, f2fs_hash_t name_hash,
+			unsigned int bit_pos);
+int f2fs_add_regular_entry(struct inode *dir, const struct qstr *new_name,
+			const struct qstr *orig_name,
+			struct inode *inode, nid_t ino, umode_t mode);
+int __f2fs_do_add_link(struct inode *dir, struct fscrypt_name *fname,
+			struct inode *inode, nid_t ino, umode_t mode);
+int __f2fs_add_link(struct inode *dir, const struct qstr *name,
+			struct inode *inode, nid_t ino, umode_t mode);
+void f2fs_delete_entry(struct f2fs_dir_entry *dentry, struct page *page,
+			struct inode *dir, struct inode *inode);
+int f2fs_do_tmpfile(struct inode *inode, struct inode *dir);
+bool f2fs_empty_dir(struct inode *dir);
+
+static inline int f2fs_add_link(struct dentry *dentry, struct inode *inode)
+{
+	return __f2fs_add_link(d_inode(dentry->d_parent), &dentry->d_name,
+				inode, inode->i_ino, inode->i_mode);
+}
+
+/*
+ * super.c
+ */
+int f2fs_inode_dirtied(struct inode *inode, bool sync);
+void f2fs_inode_synced(struct inode *inode);
+int f2fs_enable_quota_files(struct f2fs_sb_info *sbi, bool rdonly);
+void f2fs_quota_off_umount(struct super_block *sb);
+int f2fs_commit_super(struct f2fs_sb_info *sbi, bool recover);
+int f2fs_sync_fs(struct super_block *sb, int sync);
+extern __printf(3, 4)
+void f2fs_msg(struct super_block *sb, const char *level, const char *fmt, ...);
+int sanity_check_ckpt(struct f2fs_sb_info *sbi);
+
+/*
+ * hash.c
+ */
+f2fs_hash_t f2fs_dentry_hash(const struct qstr *name_info,
+				struct fscrypt_name *fname);
+
+/*
+ * node.c
+ */
+struct dnode_of_data;
+struct node_info;
+
+int check_nid_range(struct f2fs_sb_info *sbi, nid_t nid);
+bool available_free_memory(struct f2fs_sb_info *sbi, int type);
+int need_dentry_mark(struct f2fs_sb_info *sbi, nid_t nid);
+bool is_checkpointed_node(struct f2fs_sb_info *sbi, nid_t nid);
+bool need_inode_block_update(struct f2fs_sb_info *sbi, nid_t ino);
+void get_node_info(struct f2fs_sb_info *sbi, nid_t nid, struct node_info *ni);
+pgoff_t get_next_page_offset(struct dnode_of_data *dn, pgoff_t pgofs);
+int get_dnode_of_data(struct dnode_of_data *dn, pgoff_t index, int mode);
+int truncate_inode_blocks(struct inode *inode, pgoff_t from);
+int truncate_xattr_node(struct inode *inode);
+int wait_on_node_pages_writeback(struct f2fs_sb_info *sbi, nid_t ino);
+int remove_inode_page(struct inode *inode);
+struct page *new_inode_page(struct inode *inode);
+struct page *new_node_page(struct dnode_of_data *dn, unsigned int ofs);
+void ra_node_page(struct f2fs_sb_info *sbi, nid_t nid);
+struct page *get_node_page(struct f2fs_sb_info *sbi, pgoff_t nid);
+struct page *get_node_page_ra(struct page *parent, int start);
+void move_node_page(struct page *node_page, int gc_type);
+int fsync_node_pages(struct f2fs_sb_info *sbi, struct inode *inode,
+			struct writeback_control *wbc, bool atomic);
+int sync_node_pages(struct f2fs_sb_info *sbi, struct writeback_control *wbc,
+			bool do_balance, enum iostat_type io_type);
+void build_free_nids(struct f2fs_sb_info *sbi, bool sync, bool mount);
+bool alloc_nid(struct f2fs_sb_info *sbi, nid_t *nid);
+void alloc_nid_done(struct f2fs_sb_info *sbi, nid_t nid);
+void alloc_nid_failed(struct f2fs_sb_info *sbi, nid_t nid);
+int try_to_free_nids(struct f2fs_sb_info *sbi, int nr_shrink);
+void recover_inline_xattr(struct inode *inode, struct page *page);
+int recover_xattr_data(struct inode *inode, struct page *page);
+int recover_inode_page(struct f2fs_sb_info *sbi, struct page *page);
+void restore_node_summary(struct f2fs_sb_info *sbi,
+			unsigned int segno, struct f2fs_summary_block *sum);
+void flush_nat_entries(struct f2fs_sb_info *sbi, struct cp_control *cpc);
+int build_node_manager(struct f2fs_sb_info *sbi);
+void destroy_node_manager(struct f2fs_sb_info *sbi);
+int __init create_node_manager_caches(void);
+void destroy_node_manager_caches(void);
+
+/*
+ * segment.c
+ */
+bool need_SSR(struct f2fs_sb_info *sbi);
+void register_inmem_page(struct inode *inode, struct page *page);
+void drop_inmem_pages_all(struct f2fs_sb_info *sbi);
+void drop_inmem_pages(struct inode *inode);
+void drop_inmem_page(struct inode *inode, struct page *page);
+int commit_inmem_pages(struct inode *inode);
+void f2fs_balance_fs(struct f2fs_sb_info *sbi, bool need);
+void f2fs_balance_fs_bg(struct f2fs_sb_info *sbi);
+int f2fs_issue_flush(struct f2fs_sb_info *sbi, nid_t ino);
+int create_flush_cmd_control(struct f2fs_sb_info *sbi);
+int f2fs_flush_device_cache(struct f2fs_sb_info *sbi);
+void destroy_flush_cmd_control(struct f2fs_sb_info *sbi, bool free);
+void invalidate_blocks(struct f2fs_sb_info *sbi, block_t addr);
+bool is_checkpointed_data(struct f2fs_sb_info *sbi, block_t blkaddr);
+void drop_discard_cmd(struct f2fs_sb_info *sbi);
+void stop_discard_thread(struct f2fs_sb_info *sbi);
+bool f2fs_wait_discard_bios(struct f2fs_sb_info *sbi);
+void clear_prefree_segments(struct f2fs_sb_info *sbi, struct cp_control *cpc);
+void release_discard_addrs(struct f2fs_sb_info *sbi);
+int npages_for_summary_flush(struct f2fs_sb_info *sbi, bool for_ra);
+void allocate_new_segments(struct f2fs_sb_info *sbi);
+int f2fs_trim_fs(struct f2fs_sb_info *sbi, struct fstrim_range *range);
+bool exist_trim_candidates(struct f2fs_sb_info *sbi, struct cp_control *cpc);
+struct page *get_sum_page(struct f2fs_sb_info *sbi, unsigned int segno);
+void update_meta_page(struct f2fs_sb_info *sbi, void *src, block_t blk_addr);
+void write_meta_page(struct f2fs_sb_info *sbi, struct page *page,
+						enum iostat_type io_type);
+void write_node_page(unsigned int nid, struct f2fs_io_info *fio);
+void write_data_page(struct dnode_of_data *dn, struct f2fs_io_info *fio);
+int rewrite_data_page(struct f2fs_io_info *fio);
+void __f2fs_replace_block(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
+			block_t old_blkaddr, block_t new_blkaddr,
+			bool recover_curseg, bool recover_newaddr);
+void f2fs_replace_block(struct f2fs_sb_info *sbi, struct dnode_of_data *dn,
+			block_t old_addr, block_t new_addr,
+			unsigned char version, bool recover_curseg,
+			bool recover_newaddr);
+void allocate_data_block(struct f2fs_sb_info *sbi, struct page *page,
+			block_t old_blkaddr, block_t *new_blkaddr,
+			struct f2fs_summary *sum, int type,
+			struct f2fs_io_info *fio, bool add_list);
+void f2fs_wait_on_page_writeback(struct page *page,
+			enum page_type type, bool ordered);
+void f2fs_wait_on_block_writeback(struct f2fs_sb_info *sbi, block_t blkaddr);
+void write_data_summaries(struct f2fs_sb_info *sbi, block_t start_blk);
+void write_node_summaries(struct f2fs_sb_info *sbi, block_t start_blk);
+int lookup_journal_in_cursum(struct f2fs_journal *journal, int type,
+			unsigned int val, int alloc);
+void flush_sit_entries(struct f2fs_sb_info *sbi, struct cp_control *cpc);
+int build_segment_manager(struct f2fs_sb_info *sbi);
+void destroy_segment_manager(struct f2fs_sb_info *sbi);
+int __init create_segment_manager_caches(void);
+void destroy_segment_manager_caches(void);
+int rw_hint_to_seg_type(enum rw_hint hint);
+enum rw_hint io_type_to_rw_hint(struct f2fs_sb_info *sbi, enum page_type type,
+				enum temp_type temp);
+
+/*
+ * checkpoint.c
+ */
+void f2fs_stop_checkpoint(struct f2fs_sb_info *sbi, bool end_io);
+struct page *grab_meta_page(struct f2fs_sb_info *sbi, pgoff_t index);
+struct page *get_meta_page(struct f2fs_sb_info *sbi, pgoff_t index);
+struct page *get_tmp_page(struct f2fs_sb_info *sbi, pgoff_t index);
+bool f2fs_is_valid_blkaddr(struct f2fs_sb_info *sbi,
+					block_t blkaddr, int type);
+int ra_meta_pages(struct f2fs_sb_info *sbi, block_t start, int nrpages,
+			int type, bool sync);
+void ra_meta_pages_cond(struct f2fs_sb_info *sbi, pgoff_t index);
+long sync_meta_pages(struct f2fs_sb_info *sbi, enum page_type type,
+			long nr_to_write, enum iostat_type io_type);
+void add_ino_entry(struct f2fs_sb_info *sbi, nid_t ino, int type);
+void remove_ino_entry(struct f2fs_sb_info *sbi, nid_t ino, int type);
+void release_ino_entry(struct f2fs_sb_info *sbi, bool all);
+bool exist_written_data(struct f2fs_sb_info *sbi, nid_t ino, int mode);
+void set_dirty_device(struct f2fs_sb_info *sbi, nid_t ino,
+					unsigned int devidx, int type);
+bool is_dirty_device(struct f2fs_sb_info *sbi, nid_t ino,
+					unsigned int devidx, int type);
+int f2fs_sync_inode_meta(struct f2fs_sb_info *sbi);
+int acquire_orphan_inode(struct f2fs_sb_info *sbi);
+void release_orphan_inode(struct f2fs_sb_info *sbi);
+void add_orphan_inode(struct inode *inode);
+void remove_orphan_inode(struct f2fs_sb_info *sbi, nid_t ino);
+int recover_orphan_inodes(struct f2fs_sb_info *sbi);
+int get_valid_checkpoint(struct f2fs_sb_info *sbi);
+void update_dirty_page(struct inode *inode, struct page *page);
+void remove_dirty_inode(struct inode *inode);
+int sync_dirty_inodes(struct f2fs_sb_info *sbi, enum inode_type type);
+int write_checkpoint(struct f2fs_sb_info *sbi, struct cp_control *cpc);
+void init_ino_entry_info(struct f2fs_sb_info *sbi);
+int __init create_checkpoint_caches(void);
+void destroy_checkpoint_caches(void);
+
+/*
+ * data.c
+ */
+int f2fs_init_post_read_processing(void);
+void f2fs_destroy_post_read_processing(void);
+void f2fs_submit_merged_write(struct f2fs_sb_info *sbi, enum page_type type);
+void f2fs_submit_merged_write_cond(struct f2fs_sb_info *sbi,
+				struct inode *inode, nid_t ino, pgoff_t idx,
+				enum page_type type);
+void f2fs_flush_merged_writes(struct f2fs_sb_info *sbi);
+int f2fs_submit_page_bio(struct f2fs_io_info *fio);
+int f2fs_submit_page_write(struct f2fs_io_info *fio);
+struct block_device *f2fs_target_device(struct f2fs_sb_info *sbi,
+			block_t blk_addr, struct bio *bio);
+int f2fs_target_device_index(struct f2fs_sb_info *sbi, block_t blkaddr);
+void set_data_blkaddr(struct dnode_of_data *dn);
+void f2fs_update_data_blkaddr(struct dnode_of_data *dn, block_t blkaddr);
+int reserve_new_blocks(struct dnode_of_data *dn, blkcnt_t count);
+int reserve_new_block(struct dnode_of_data *dn);
+int f2fs_get_block(struct dnode_of_data *dn, pgoff_t index);
+int f2fs_preallocate_blocks(struct kiocb *iocb, struct iov_iter *from);
+int f2fs_reserve_block(struct dnode_of_data *dn, pgoff_t index);
+struct page *get_read_data_page(struct inode *inode, pgoff_t index,
+			int op_flags, bool for_write);
+struct page *find_data_page(struct inode *inode, pgoff_t index);
+struct page *get_lock_data_page(struct inode *inode, pgoff_t index,
+			bool for_write);
+struct page *get_new_data_page(struct inode *inode,
+			struct page *ipage, pgoff_t index, bool new_i_size);
+int do_write_data_page(struct f2fs_io_info *fio);
+int f2fs_map_blocks(struct inode *inode, struct f2fs_map_blocks *map,
+			int create, int flag);
+int f2fs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
+			u64 start, u64 len);
+bool should_update_inplace(struct inode *inode, struct f2fs_io_info *fio);
+bool should_update_outplace(struct inode *inode, struct f2fs_io_info *fio);
+int __f2fs_write_data_pages(struct address_space *mapping,
+						struct writeback_control *wbc,
+						enum iostat_type io_type);
+void f2fs_invalidate_page(struct page *page, unsigned int offset,
+			unsigned int length);
+int f2fs_release_page(struct page *page, gfp_t wait);
+#ifdef CONFIG_MIGRATION
+int f2fs_migrate_page(struct address_space *mapping, struct page *newpage,
+			struct page *page, enum migrate_mode mode);
+#endif
+bool f2fs_overwrite_io(struct inode *inode, loff_t pos, size_t len);
+
+/*
+ * gc.c
+ */
+int start_gc_thread(struct f2fs_sb_info *sbi);
+void stop_gc_thread(struct f2fs_sb_info *sbi);
+block_t start_bidx_of_node(unsigned int node_ofs, struct inode *inode);
+int f2fs_gc(struct f2fs_sb_info *sbi, bool sync, bool background,
+			unsigned int segno);
+void build_gc_manager(struct f2fs_sb_info *sbi);
+
+/*
+ * recovery.c
+ */
+int recover_fsync_data(struct f2fs_sb_info *sbi, bool check_only);
+bool space_for_roll_forward(struct f2fs_sb_info *sbi);
+
+/*
+ * debug.c
+ */
+#ifdef CONFIG_F2FS_STAT_FS
+struct f2fs_stat_info {
+	struct list_head stat_list;
+	struct f2fs_sb_info *sbi;
+	int all_area_segs, sit_area_segs, nat_area_segs, ssa_area_segs;
+	int main_area_segs, main_area_sections, main_area_zones;
+	unsigned long long hit_largest, hit_cached, hit_rbtree;
+	unsigned long long hit_total, total_ext;
+	int ext_tree, zombie_tree, ext_node;
+	int ndirty_node, ndirty_dent, ndirty_meta, ndirty_imeta;
+	int ndirty_data, ndirty_qdata;
+	int inmem_pages;
+	unsigned int ndirty_dirs, ndirty_files, nquota_files, ndirty_all;
+	int nats, dirty_nats, sits, dirty_sits;
+	int free_nids, avail_nids, alloc_nids;
+	int total_count, utilization;
+	int bg_gc, nr_wb_cp_data, nr_wb_data;
+	int nr_flushing, nr_flushed, flush_list_empty;
+	int nr_discarding, nr_discarded;
+	int nr_discard_cmd;
+	unsigned int undiscard_blks;
+	int inline_xattr, inline_inode, inline_dir, append, update, orphans;
+	int aw_cnt, max_aw_cnt, vw_cnt, max_vw_cnt;
+	unsigned int valid_count, valid_node_count, valid_inode_count, discard_blks;
+	unsigned int bimodal, avg_vblocks;
+	int util_free, util_valid, util_invalid;
+	int rsvd_segs, overp_segs;
+	int dirty_count, node_pages, meta_pages;
+	int prefree_count, call_count, cp_count, bg_cp_count;
+	int tot_segs, node_segs, data_segs, free_segs, free_secs;
+	int bg_node_segs, bg_data_segs;
+	int tot_blks, data_blks, node_blks;
+	int bg_data_blks, bg_node_blks;
+	int curseg[NR_CURSEG_TYPE];
+	int cursec[NR_CURSEG_TYPE];
+	int curzone[NR_CURSEG_TYPE];
+
+	unsigned int segment_count[2];
+	unsigned int block_count[2];
+	unsigned int inplace_count;
+	unsigned long long base_mem, cache_mem, page_mem;
+};
+
+static inline struct f2fs_stat_info *F2FS_STAT(struct f2fs_sb_info *sbi)
+{
+	return (struct f2fs_stat_info *)sbi->stat_info;
+}
+
+#define stat_inc_cp_count(si)		((si)->cp_count++)
+#define stat_inc_bg_cp_count(si)	((si)->bg_cp_count++)
+#define stat_inc_call_count(si)		((si)->call_count++)
+#define stat_inc_bggc_count(sbi)	((sbi)->bg_gc++)
+#define stat_inc_dirty_inode(sbi, type)	((sbi)->ndirty_inode[type]++)
+#define stat_dec_dirty_inode(sbi, type)	((sbi)->ndirty_inode[type]--)
+#define stat_inc_total_hit(sbi)		(atomic64_inc(&(sbi)->total_hit_ext))
+#define stat_inc_rbtree_node_hit(sbi)	(atomic64_inc(&(sbi)->read_hit_rbtree))
+#define stat_inc_largest_node_hit(sbi)	(atomic64_inc(&(sbi)->read_hit_largest))
+#define stat_inc_cached_node_hit(sbi)	(atomic64_inc(&(sbi)->read_hit_cached))
+#define stat_inc_inline_xattr(inode)					\
+	do {								\
+		if (f2fs_has_inline_xattr(inode))			\
+			(atomic_inc(&F2FS_I_SB(inode)->inline_xattr));	\
+	} while (0)
+#define stat_dec_inline_xattr(inode)					\
+	do {								\
+		if (f2fs_has_inline_xattr(inode))			\
+			(atomic_dec(&F2FS_I_SB(inode)->inline_xattr));	\
+	} while (0)
+#define stat_inc_inline_inode(inode)					\
+	do {								\
+		if (f2fs_has_inline_data(inode))			\
+			(atomic_inc(&F2FS_I_SB(inode)->inline_inode));	\
+	} while (0)
+#define stat_dec_inline_inode(inode)					\
+	do {								\
+		if (f2fs_has_inline_data(inode))			\
+			(atomic_dec(&F2FS_I_SB(inode)->inline_inode));	\
+	} while (0)
+#define stat_inc_inline_dir(inode)					\
+	do {								\
+		if (f2fs_has_inline_dentry(inode))			\
+			(atomic_inc(&F2FS_I_SB(inode)->inline_dir));	\
+	} while (0)
+#define stat_dec_inline_dir(inode)					\
+	do {								\
+		if (f2fs_has_inline_dentry(inode))			\
+			(atomic_dec(&F2FS_I_SB(inode)->inline_dir));	\
+	} while (0)
+#define stat_inc_seg_type(sbi, curseg)					\
+		((sbi)->segment_count[(curseg)->alloc_type]++)
+#define stat_inc_block_count(sbi, curseg)				\
+		((sbi)->block_count[(curseg)->alloc_type]++)
+#define stat_inc_inplace_blocks(sbi)					\
+		(atomic_inc(&(sbi)->inplace_count))
+#define stat_inc_atomic_write(inode)					\
+		(atomic_inc(&F2FS_I_SB(inode)->aw_cnt))
+#define stat_dec_atomic_write(inode)					\
+		(atomic_dec(&F2FS_I_SB(inode)->aw_cnt))
+#define stat_update_max_atomic_write(inode)				\
+	do {								\
+		int cur = atomic_read(&F2FS_I_SB(inode)->aw_cnt);	\
+		int max = atomic_read(&F2FS_I_SB(inode)->max_aw_cnt);	\
+		if (cur > max)						\
+			atomic_set(&F2FS_I_SB(inode)->max_aw_cnt, cur);	\
+	} while (0)
+#define stat_inc_volatile_write(inode)					\
+		(atomic_inc(&F2FS_I_SB(inode)->vw_cnt))
+#define stat_dec_volatile_write(inode)					\
+		(atomic_dec(&F2FS_I_SB(inode)->vw_cnt))
+#define stat_update_max_volatile_write(inode)				\
+	do {								\
+		int cur = atomic_read(&F2FS_I_SB(inode)->vw_cnt);	\
+		int max = atomic_read(&F2FS_I_SB(inode)->max_vw_cnt);	\
+		if (cur > max)						\
+			atomic_set(&F2FS_I_SB(inode)->max_vw_cnt, cur);	\
+	} while (0)
+#define stat_inc_seg_count(sbi, type, gc_type)				\
+	do {								\
+		struct f2fs_stat_info *si = F2FS_STAT(sbi);		\
+		si->tot_segs++;						\
+		if ((type) == SUM_TYPE_DATA) {				\
+			si->data_segs++;				\
+			si->bg_data_segs += (gc_type == BG_GC) ? 1 : 0;	\
+		} else {						\
+			si->node_segs++;				\
+			si->bg_node_segs += (gc_type == BG_GC) ? 1 : 0;	\
+		}							\
+	} while (0)
+
+#define stat_inc_tot_blk_count(si, blks)				\
+	((si)->tot_blks += (blks))
+
+#define stat_inc_data_blk_count(sbi, blks, gc_type)			\
+	do {								\
+		struct f2fs_stat_info *si = F2FS_STAT(sbi);		\
+		stat_inc_tot_blk_count(si, blks);			\
+		si->data_blks += (blks);				\
+		si->bg_data_blks += ((gc_type) == BG_GC) ? (blks) : 0;	\
+	} while (0)
+
+#define stat_inc_node_blk_count(sbi, blks, gc_type)			\
+	do {								\
+		struct f2fs_stat_info *si = F2FS_STAT(sbi);		\
+		stat_inc_tot_blk_count(si, blks);			\
+		si->node_blks += (blks);				\
+		si->bg_node_blks += ((gc_type) == BG_GC) ? (blks) : 0;	\
+	} while (0)
+
+int f2fs_build_stats(struct f2fs_sb_info *sbi);
+void f2fs_destroy_stats(struct f2fs_sb_info *sbi);
+int __init f2fs_create_root_stats(void);
+void f2fs_destroy_root_stats(void);
+#else
+#define stat_inc_cp_count(si)				do { } while (0)
+#define stat_inc_bg_cp_count(si)			do { } while (0)
+#define stat_inc_call_count(si)				do { } while (0)
+#define stat_inc_bggc_count(si)				do { } while (0)
+#define stat_inc_dirty_inode(sbi, type)			do { } while (0)
+#define stat_dec_dirty_inode(sbi, type)			do { } while (0)
+#define stat_inc_total_hit(sb)				do { } while (0)
+#define stat_inc_rbtree_node_hit(sb)			do { } while (0)
+#define stat_inc_largest_node_hit(sbi)			do { } while (0)
+#define stat_inc_cached_node_hit(sbi)			do { } while (0)
+#define stat_inc_inline_xattr(inode)			do { } while (0)
+#define stat_dec_inline_xattr(inode)			do { } while (0)
+#define stat_inc_inline_inode(inode)			do { } while (0)
+#define stat_dec_inline_inode(inode)			do { } while (0)
+#define stat_inc_inline_dir(inode)			do { } while (0)
+#define stat_dec_inline_dir(inode)			do { } while (0)
+#define stat_inc_atomic_write(inode)			do { } while (0)
+#define stat_dec_atomic_write(inode)			do { } while (0)
+#define stat_update_max_atomic_write(inode)		do { } while (0)
+#define stat_inc_volatile_write(inode)			do { } while (0)
+#define stat_dec_volatile_write(inode)			do { } while (0)
+#define stat_update_max_volatile_write(inode)		do { } while (0)
+#define stat_inc_seg_type(sbi, curseg)			do { } while (0)
+#define stat_inc_block_count(sbi, curseg)		do { } while (0)
+#define stat_inc_inplace_blocks(sbi)			do { } while (0)
+#define stat_inc_seg_count(sbi, type, gc_type)		do { } while (0)
+#define stat_inc_tot_blk_count(si, blks)		do { } while (0)
+#define stat_inc_data_blk_count(sbi, blks, gc_type)	do { } while (0)
+#define stat_inc_node_blk_count(sbi, blks, gc_type)	do { } while (0)
+
+static inline int f2fs_build_stats(struct f2fs_sb_info *sbi) { return 0; }
+static inline void f2fs_destroy_stats(struct f2fs_sb_info *sbi) { }
+static inline int __init f2fs_create_root_stats(void) { return 0; }
+static inline void f2fs_destroy_root_stats(void) { }
+#endif
+
+extern const struct file_operations f2fs_dir_operations;
+extern const struct file_operations f2fs_file_operations;
+extern const struct inode_operations f2fs_file_inode_operations;
+extern const struct address_space_operations f2fs_dblock_aops;
+extern const struct address_space_operations f2fs_node_aops;
+extern const struct address_space_operations f2fs_meta_aops;
+extern const struct inode_operations f2fs_dir_inode_operations;
+extern const struct inode_operations f2fs_symlink_inode_operations;
+extern const struct inode_operations f2fs_encrypted_symlink_inode_operations;
+extern const struct inode_operations f2fs_special_inode_operations;
+extern struct kmem_cache *inode_entry_slab;
+
+/*
+ * inline.c
+ */
+bool f2fs_may_inline_data(struct inode *inode);
+bool f2fs_may_inline_dentry(struct inode *inode);
+void read_inline_data(struct page *page, struct page *ipage);
+void truncate_inline_inode(struct inode *inode, struct page *ipage, u64 from);
+int f2fs_read_inline_data(struct inode *inode, struct page *page);
+int f2fs_convert_inline_page(struct dnode_of_data *dn, struct page *page);
+int f2fs_convert_inline_inode(struct inode *inode);
+int f2fs_write_inline_data(struct inode *inode, struct page *page);
+bool recover_inline_data(struct inode *inode, struct page *npage);
+struct f2fs_dir_entry *find_in_inline_dir(struct inode *dir,
+			struct fscrypt_name *fname, struct page **res_page);
+int make_empty_inline_dir(struct inode *inode, struct inode *parent,
+			struct page *ipage);
+int f2fs_add_inline_entry(struct inode *dir, const struct qstr *new_name,
+			const struct qstr *orig_name,
+			struct inode *inode, nid_t ino, umode_t mode);
+void f2fs_delete_inline_entry(struct f2fs_dir_entry *dentry, struct page *page,
+			struct inode *dir, struct inode *inode);
+bool f2fs_empty_inline_dir(struct inode *dir);
+int f2fs_read_inline_dir(struct file *file, struct dir_context *ctx,
+			struct fscrypt_str *fstr);
+int f2fs_inline_data_fiemap(struct inode *inode,
+			struct fiemap_extent_info *fieinfo,
+			__u64 start, __u64 len);
+
+/*
+ * shrinker.c
+ */
+unsigned long f2fs_shrink_count(struct shrinker *shrink,
+			struct shrink_control *sc);
+unsigned long f2fs_shrink_scan(struct shrinker *shrink,
+			struct shrink_control *sc);
+void f2fs_join_shrinker(struct f2fs_sb_info *sbi);
+void f2fs_leave_shrinker(struct f2fs_sb_info *sbi);
+
+/*
+ * extent_cache.c
+ */
+struct rb_entry *__lookup_rb_tree(struct rb_root *root,
+				struct rb_entry *cached_re, unsigned int ofs);
+struct rb_node **__lookup_rb_tree_for_insert(struct f2fs_sb_info *sbi,
+				struct rb_root *root, struct rb_node **parent,
+				unsigned int ofs);
+struct rb_entry *__lookup_rb_tree_ret(struct rb_root *root,
+		struct rb_entry *cached_re, unsigned int ofs,
+		struct rb_entry **prev_entry, struct rb_entry **next_entry,
+		struct rb_node ***insert_p, struct rb_node **insert_parent,
+		bool force);
+bool __check_rb_tree_consistence(struct f2fs_sb_info *sbi,
+						struct rb_root *root);
+unsigned int f2fs_shrink_extent_tree(struct f2fs_sb_info *sbi, int nr_shrink);
+bool f2fs_init_extent_tree(struct inode *inode, struct f2fs_extent *i_ext);
+void f2fs_drop_extent_tree(struct inode *inode);
+unsigned int f2fs_destroy_extent_node(struct inode *inode);
+void f2fs_destroy_extent_tree(struct inode *inode);
+bool f2fs_lookup_extent_cache(struct inode *inode, pgoff_t pgofs,
+			struct extent_info *ei);
+void f2fs_update_extent_cache(struct dnode_of_data *dn);
+void f2fs_update_extent_cache_range(struct dnode_of_data *dn,
+			pgoff_t fofs, block_t blkaddr, unsigned int len);
+void init_extent_cache_info(struct f2fs_sb_info *sbi);
+int __init create_extent_cache(void);
+void destroy_extent_cache(void);
+
+/*
+ * sysfs.c
+ */
+int __init f2fs_init_sysfs(void);
+void f2fs_exit_sysfs(void);
+int f2fs_register_sysfs(struct f2fs_sb_info *sbi);
+void f2fs_unregister_sysfs(struct f2fs_sb_info *sbi);
+
+/*
+ * crypto support
+ */
+static inline bool f2fs_encrypted_inode(struct inode *inode)
+{
+	return file_is_encrypt(inode);
+}
+
+static inline bool f2fs_encrypted_file(struct inode *inode)
+{
+	return f2fs_encrypted_inode(inode) && S_ISREG(inode->i_mode);
+}
+
+static inline void f2fs_set_encrypted_inode(struct inode *inode)
+{
+#ifdef CONFIG_F2FS_FS_ENCRYPTION
+	file_set_encrypt(inode);
+	inode->i_flags |= S_ENCRYPTED;
+#endif
+}
+
+/*
+ * Returns true if the reads of the inode's data need to undergo some
+ * postprocessing step, like decryption or authenticity verification.
+ */
+static inline bool f2fs_post_read_required(struct inode *inode)
+{
+	return f2fs_encrypted_file(inode);
+}
+
+#define F2FS_FEATURE_FUNCS(name, flagname) \
+static inline int f2fs_sb_has_##name(struct super_block *sb) \
+{ \
+	return F2FS_HAS_FEATURE(sb, F2FS_FEATURE_##flagname); \
+}
+
+F2FS_FEATURE_FUNCS(encrypt, ENCRYPT);
+F2FS_FEATURE_FUNCS(blkzoned, BLKZONED);
+F2FS_FEATURE_FUNCS(extra_attr, EXTRA_ATTR);
+F2FS_FEATURE_FUNCS(project_quota, PRJQUOTA);
+F2FS_FEATURE_FUNCS(inode_chksum, INODE_CHKSUM);
+F2FS_FEATURE_FUNCS(flexible_inline_xattr, FLEXIBLE_INLINE_XATTR);
+F2FS_FEATURE_FUNCS(quota_ino, QUOTA_INO);
+F2FS_FEATURE_FUNCS(inode_crtime, INODE_CRTIME);
+F2FS_FEATURE_FUNCS(lost_found, LOST_FOUND);
+
+#ifdef CONFIG_BLK_DEV_ZONED
+static inline int get_blkz_type(struct f2fs_sb_info *sbi,
+			struct block_device *bdev, block_t blkaddr)
+{
+	unsigned int zno = blkaddr >> sbi->log_blocks_per_blkz;
+	int i;
+
+	for (i = 0; i < sbi->s_ndevs; i++)
+		if (FDEV(i).bdev == bdev)
+			return FDEV(i).blkz_type[zno];
+	return -EINVAL;
+}
+#endif
+
+static inline bool f2fs_discard_en(struct f2fs_sb_info *sbi)
+{
+	struct request_queue *q = bdev_get_queue(sbi->sb->s_bdev);
+
+	return blk_queue_discard(q) || f2fs_sb_has_blkzoned(sbi->sb);
+}
+
+static inline void set_opt_mode(struct f2fs_sb_info *sbi, unsigned int mt)
+{
+	clear_opt(sbi, ADAPTIVE);
+	clear_opt(sbi, LFS);
+
+	switch (mt) {
+	case F2FS_MOUNT_ADAPTIVE:
+		set_opt(sbi, ADAPTIVE);
+		break;
+	case F2FS_MOUNT_LFS:
+		set_opt(sbi, LFS);
+		break;
+	}
+}
+
+static inline bool f2fs_may_encrypt(struct inode *inode)
+{
+#ifdef CONFIG_F2FS_FS_ENCRYPTION
+	umode_t mode = inode->i_mode;
+
+	return (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode));
+#else
+	return 0;
+#endif
+}
+
+static inline bool f2fs_force_buffered_io(struct inode *inode, int rw)
+{
+	return (f2fs_post_read_required(inode) ||
+			(rw == WRITE && test_opt(F2FS_I_SB(inode), LFS)) ||
+			F2FS_I_SB(inode)->s_ndevs);
+}
+
+#endif
+
+#define EFSBADCRC	EBADMSG		/* Bad CRC detected */
+#define EFSCORRUPTED	EUCLEAN		/* Filesystem is corrupted */
+
diff --git a/src/kernel/linux/v4.14/fs/f2fs/file.c b/src/kernel/linux/v4.14/fs/f2fs/file.c
new file mode 100644
index 0000000..be68661
--- /dev/null
+++ b/src/kernel/linux/v4.14/fs/f2fs/file.c
@@ -0,0 +1,3042 @@
+/*
+ * fs/f2fs/file.c
+ *
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ *             http://www.samsung.com/
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/fs.h>
+#include <linux/f2fs_fs.h>
+#include <linux/stat.h>
+#include <linux/buffer_head.h>
+#include <linux/writeback.h>
+#include <linux/blkdev.h>
+#include <linux/falloc.h>
+#include <linux/types.h>
+#include <linux/compat.h>
+#include <linux/uaccess.h>
+#include <linux/mount.h>
+#include <linux/pagevec.h>
+#include <linux/uio.h>
+#include <linux/uuid.h>
+#include <linux/file.h>
+
+#include "f2fs.h"
+#include "node.h"
+#include "segment.h"
+#include "xattr.h"
+#include "acl.h"
+#include "gc.h"
+#include "trace.h"
+#include <trace/events/f2fs.h>
+
+static int f2fs_filemap_fault(struct vm_fault *vmf)
+{
+	struct inode *inode = file_inode(vmf->vma->vm_file);
+	int err;
+
+	down_read(&F2FS_I(inode)->i_mmap_sem);
+	err = filemap_fault(vmf);
+	up_read(&F2FS_I(inode)->i_mmap_sem);
+
+	return err;
+}
+
+static int f2fs_vm_page_mkwrite(struct vm_fault *vmf)
+{
+	struct page *page = vmf->page;
+	struct inode *inode = file_inode(vmf->vma->vm_file);
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct dnode_of_data dn;
+	int err;
+
+	if (unlikely(f2fs_cp_error(sbi))) {
+		err = -EIO;
+		goto err;
+	}
+
+	sb_start_pagefault(inode->i_sb);
+
+	f2fs_bug_on(sbi, f2fs_has_inline_data(inode));
+
+	/* block allocation */
+	f2fs_lock_op(sbi);
+	set_new_dnode(&dn, inode, NULL, NULL, 0);
+	err = f2fs_reserve_block(&dn, page->index);
+	if (err) {
+		f2fs_unlock_op(sbi);
+		goto out;
+	}
+	f2fs_put_dnode(&dn);
+	f2fs_unlock_op(sbi);
+
+	f2fs_balance_fs(sbi, dn.node_changed);
+
+	file_update_time(vmf->vma->vm_file);
+	down_read(&F2FS_I(inode)->i_mmap_sem);
+	lock_page(page);
+	if (unlikely(page->mapping != inode->i_mapping ||
+			page_offset(page) > i_size_read(inode) ||
+			!PageUptodate(page))) {
+		unlock_page(page);
+		err = -EFAULT;
+		goto out_sem;
+	}
+
+	/*
+	 * check to see if the page is mapped already (no holes)
+	 */
+	if (PageMappedToDisk(page))
+		goto mapped;
+
+	/* page is wholly or partially inside EOF */
+	if (((loff_t)(page->index + 1) << PAGE_SHIFT) >
+						i_size_read(inode)) {
+		unsigned offset;
+		offset = i_size_read(inode) & ~PAGE_MASK;
+		zero_user_segment(page, offset, PAGE_SIZE);
+	}
+	set_page_dirty(page);
+	if (!PageUptodate(page))
+		SetPageUptodate(page);
+
+	f2fs_update_iostat(sbi, APP_MAPPED_IO, F2FS_BLKSIZE);
+
+	trace_f2fs_vm_page_mkwrite(page, DATA);
+mapped:
+	/* fill the page */
+	f2fs_wait_on_page_writeback(page, DATA, false);
+
+	/* wait for GCed page writeback via META_MAPPING */
+	if (f2fs_post_read_required(inode))
+		f2fs_wait_on_block_writeback(sbi, dn.data_blkaddr);
+
+out_sem:
+	up_read(&F2FS_I(inode)->i_mmap_sem);
+out:
+	sb_end_pagefault(inode->i_sb);
+	f2fs_update_time(sbi, REQ_TIME);
+err:
+	return block_page_mkwrite_return(err);
+}
+
+static const struct vm_operations_struct f2fs_file_vm_ops = {
+	.fault		= f2fs_filemap_fault,
+	.map_pages	= filemap_map_pages,
+	.page_mkwrite	= f2fs_vm_page_mkwrite,
+};
+
+static int get_parent_ino(struct inode *inode, nid_t *pino)
+{
+	struct dentry *dentry;
+
+	inode = igrab(inode);
+	dentry = d_find_any_alias(inode);
+	iput(inode);
+	if (!dentry)
+		return 0;
+
+	*pino = parent_ino(dentry);
+	dput(dentry);
+	return 1;
+}
+
+static inline enum cp_reason_type need_do_checkpoint(struct inode *inode)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	enum cp_reason_type cp_reason = CP_NO_NEEDED;
+
+	if (!S_ISREG(inode->i_mode))
+		cp_reason = CP_NON_REGULAR;
+	else if (inode->i_nlink != 1)
+		cp_reason = CP_HARDLINK;
+	else if (is_sbi_flag_set(sbi, SBI_NEED_CP))
+		cp_reason = CP_SB_NEED_CP;
+	else if (file_wrong_pino(inode))
+		cp_reason = CP_WRONG_PINO;
+	else if (!space_for_roll_forward(sbi))
+		cp_reason = CP_NO_SPC_ROLL;
+	else if (!is_checkpointed_node(sbi, F2FS_I(inode)->i_pino))
+		cp_reason = CP_NODE_NEED_CP;
+	else if (test_opt(sbi, FASTBOOT))
+		cp_reason = CP_FASTBOOT_MODE;
+	else if (F2FS_OPTION(sbi).active_logs == 2)
+		cp_reason = CP_SPEC_LOG_NUM;
+	else if (F2FS_OPTION(sbi).fsync_mode == FSYNC_MODE_STRICT &&
+		need_dentry_mark(sbi, inode->i_ino) &&
+		exist_written_data(sbi, F2FS_I(inode)->i_pino, TRANS_DIR_INO))
+		cp_reason = CP_RECOVER_DIR;
+
+	return cp_reason;
+}
+
+static bool need_inode_page_update(struct f2fs_sb_info *sbi, nid_t ino)
+{
+	struct page *i = find_get_page(NODE_MAPPING(sbi), ino);
+	bool ret = false;
+	/* But we need to avoid that there are some inode updates */
+	if ((i && PageDirty(i)) || need_inode_block_update(sbi, ino))
+		ret = true;
+	f2fs_put_page(i, 0);
+	return ret;
+}
+
+static void try_to_fix_pino(struct inode *inode)
+{
+	struct f2fs_inode_info *fi = F2FS_I(inode);
+	nid_t pino;
+
+	down_write(&fi->i_sem);
+	if (file_wrong_pino(inode) && inode->i_nlink == 1 &&
+			get_parent_ino(inode, &pino)) {
+		f2fs_i_pino_write(inode, pino);
+		file_got_pino(inode);
+	}
+	up_write(&fi->i_sem);
+}
+
+static int f2fs_do_sync_file(struct file *file, loff_t start, loff_t end,
+						int datasync, bool atomic)
+{
+	struct inode *inode = file->f_mapping->host;
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	nid_t ino = inode->i_ino;
+	int ret = 0;
+	enum cp_reason_type cp_reason = 0;
+	struct writeback_control wbc = {
+		.sync_mode = WB_SYNC_ALL,
+		.nr_to_write = LONG_MAX,
+		.for_reclaim = 0,
+	};
+
+	if (unlikely(f2fs_readonly(inode->i_sb)))
+		return 0;
+
+	trace_f2fs_sync_file_enter(inode);
+
+	if (S_ISDIR(inode->i_mode))
+		goto go_write;
+
+	/* if fdatasync is triggered, let's do in-place-update */
+	if (datasync || get_dirty_pages(inode) <= SM_I(sbi)->min_fsync_blocks)
+		set_inode_flag(inode, FI_NEED_IPU);
+	ret = file_write_and_wait_range(file, start, end);
+	clear_inode_flag(inode, FI_NEED_IPU);
+
+	if (ret) {
+		trace_f2fs_sync_file_exit(inode, cp_reason, datasync, ret);
+		return ret;
+	}
+
+	/* if the inode is dirty, let's recover all the time */
+	if (!f2fs_skip_inode_update(inode, datasync)) {
+		f2fs_write_inode(inode, NULL);
+		goto go_write;
+	}
+
+	/*
+	 * if there is no written data, don't waste time to write recovery info.
+	 */
+	if (!is_inode_flag_set(inode, FI_APPEND_WRITE) &&
+			!exist_written_data(sbi, ino, APPEND_INO)) {
+
+		/* it may call write_inode just prior to fsync */
+		if (need_inode_page_update(sbi, ino))
+			goto go_write;
+
+		if (is_inode_flag_set(inode, FI_UPDATE_WRITE) ||
+				exist_written_data(sbi, ino, UPDATE_INO))
+			goto flush_out;
+		goto out;
+	}
+go_write:
+	/*
+	 * Both of fdatasync() and fsync() are able to be recovered from
+	 * sudden-power-off.
+	 */
+	down_read(&F2FS_I(inode)->i_sem);
+	cp_reason = need_do_checkpoint(inode);
+	up_read(&F2FS_I(inode)->i_sem);
+
+	if (cp_reason) {
+		/* all the dirty node pages should be flushed for POR */
+		ret = f2fs_sync_fs(inode->i_sb, 1);
+
+		/*
+		 * We've secured consistency through sync_fs. Following pino
+		 * will be used only for fsynced inodes after checkpoint.
+		 */
+		try_to_fix_pino(inode);
+		clear_inode_flag(inode, FI_APPEND_WRITE);
+		clear_inode_flag(inode, FI_UPDATE_WRITE);
+		goto out;
+	}
+sync_nodes:
+	ret = fsync_node_pages(sbi, inode, &wbc, atomic);
+	if (ret)
+		goto out;
+
+	/* if cp_error was enabled, we should avoid infinite loop */
+	if (unlikely(f2fs_cp_error(sbi))) {
+		ret = -EIO;
+		goto out;
+	}
+
+	if (need_inode_block_update(sbi, ino)) {
+		f2fs_mark_inode_dirty_sync(inode, true);
+		f2fs_write_inode(inode, NULL);
+		goto sync_nodes;
+	}
+
+	/*
+	 * If it's atomic_write, it's just fine to keep write ordering. So
+	 * here we don't need to wait for node write completion, since we use
+	 * node chain which serializes node blocks. If one of node writes are
+	 * reordered, we can see simply broken chain, resulting in stopping
+	 * roll-forward recovery. It means we'll recover all or none node blocks
+	 * given fsync mark.
+	 */
+	if (!atomic) {
+		ret = wait_on_node_pages_writeback(sbi, ino);
+		if (ret)
+			goto out;
+	}
+
+	/* once recovery info is written, don't need to tack this */
+	remove_ino_entry(sbi, ino, APPEND_INO);
+	clear_inode_flag(inode, FI_APPEND_WRITE);
+flush_out:
+	if (!atomic && F2FS_OPTION(sbi).fsync_mode != FSYNC_MODE_NOBARRIER)
+		ret = f2fs_issue_flush(sbi, inode->i_ino);
+	if (!ret) {
+		remove_ino_entry(sbi, ino, UPDATE_INO);
+		clear_inode_flag(inode, FI_UPDATE_WRITE);
+		remove_ino_entry(sbi, ino, FLUSH_INO);
+	}
+	f2fs_update_time(sbi, REQ_TIME);
+out:
+	trace_f2fs_sync_file_exit(inode, cp_reason, datasync, ret);
+	f2fs_trace_ios(NULL, 1);
+	return ret;
+}
+
+int f2fs_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
+{
+	if (unlikely(f2fs_cp_error(F2FS_I_SB(file_inode(file)))))
+		return -EIO;
+	return f2fs_do_sync_file(file, start, end, datasync, false);
+}
+
+static pgoff_t __get_first_dirty_index(struct address_space *mapping,
+						pgoff_t pgofs, int whence)
+{
+	struct pagevec pvec;
+	int nr_pages;
+
+	if (whence != SEEK_DATA)
+		return 0;
+
+	/* find first dirty page index */
+	pagevec_init(&pvec, 0);
+	nr_pages = pagevec_lookup_tag(&pvec, mapping, &pgofs,
+					PAGECACHE_TAG_DIRTY, 1);
+	pgofs = nr_pages ? pvec.pages[0]->index : ULONG_MAX;
+	pagevec_release(&pvec);
+	return pgofs;
+}
+
+static bool __found_offset(struct f2fs_sb_info *sbi, block_t blkaddr,
+				pgoff_t dirty, pgoff_t pgofs, int whence)
+{
+	switch (whence) {
+	case SEEK_DATA:
+		if ((blkaddr == NEW_ADDR && dirty == pgofs) ||
+			is_valid_data_blkaddr(sbi, blkaddr))
+			return true;
+		break;
+	case SEEK_HOLE:
+		if (blkaddr == NULL_ADDR)
+			return true;
+		break;
+	}
+	return false;
+}
+
+static loff_t f2fs_seek_block(struct file *file, loff_t offset, int whence)
+{
+	struct inode *inode = file->f_mapping->host;
+	loff_t maxbytes = inode->i_sb->s_maxbytes;
+	struct dnode_of_data dn;
+	pgoff_t pgofs, end_offset, dirty;
+	loff_t data_ofs = offset;
+	loff_t isize;
+	int err = 0;
+
+	inode_lock(inode);
+
+	isize = i_size_read(inode);
+	if (offset >= isize)
+		goto fail;
+
+	/* handle inline data case */
+	if (f2fs_has_inline_data(inode) || f2fs_has_inline_dentry(inode)) {
+		if (whence == SEEK_HOLE)
+			data_ofs = isize;
+		goto found;
+	}
+
+	pgofs = (pgoff_t)(offset >> PAGE_SHIFT);
+
+	dirty = __get_first_dirty_index(inode->i_mapping, pgofs, whence);
+
+	for (; data_ofs < isize; data_ofs = (loff_t)pgofs << PAGE_SHIFT) {
+		set_new_dnode(&dn, inode, NULL, NULL, 0);
+		err = get_dnode_of_data(&dn, pgofs, LOOKUP_NODE);
+		if (err && err != -ENOENT) {
+			goto fail;
+		} else if (err == -ENOENT) {
+			/* direct node does not exists */
+			if (whence == SEEK_DATA) {
+				pgofs = get_next_page_offset(&dn, pgofs);
+				continue;
+			} else {
+				goto found;
+			}
+		}
+
+		end_offset = ADDRS_PER_PAGE(dn.node_page, inode);
+
+		/* find data/hole in dnode block */
+		for (; dn.ofs_in_node < end_offset;
+				dn.ofs_in_node++, pgofs++,
+				data_ofs = (loff_t)pgofs << PAGE_SHIFT) {
+			block_t blkaddr;
+			blkaddr = datablock_addr(dn.inode,
+					dn.node_page, dn.ofs_in_node);
+
+			if (__is_valid_data_blkaddr(blkaddr) &&
+				!f2fs_is_valid_blkaddr(F2FS_I_SB(inode),
+						blkaddr, DATA_GENERIC)) {
+				f2fs_put_dnode(&dn);
+				goto fail;
+			}
+
+			if (__found_offset(F2FS_I_SB(inode), blkaddr, dirty,
+							pgofs, whence)) {
+				f2fs_put_dnode(&dn);
+				goto found;
+			}
+		}
+		f2fs_put_dnode(&dn);
+	}
+
+	if (whence == SEEK_DATA)
+		goto fail;
+found:
+	if (whence == SEEK_HOLE && data_ofs > isize)
+		data_ofs = isize;
+	inode_unlock(inode);
+	return vfs_setpos(file, data_ofs, maxbytes);
+fail:
+	inode_unlock(inode);
+	return -ENXIO;
+}
+
+static loff_t f2fs_llseek(struct file *file, loff_t offset, int whence)
+{
+	struct inode *inode = file->f_mapping->host;
+	loff_t maxbytes = inode->i_sb->s_maxbytes;
+
+	switch (whence) {
+	case SEEK_SET:
+	case SEEK_CUR:
+	case SEEK_END:
+		return generic_file_llseek_size(file, offset, whence,
+						maxbytes, i_size_read(inode));
+	case SEEK_DATA:
+	case SEEK_HOLE:
+		if (offset < 0)
+			return -ENXIO;
+		return f2fs_seek_block(file, offset, whence);
+	}
+
+	return -EINVAL;
+}
+
+static int f2fs_file_mmap(struct file *file, struct vm_area_struct *vma)
+{
+	struct inode *inode = file_inode(file);
+	int err;
+
+	if (unlikely(f2fs_cp_error(F2FS_I_SB(inode))))
+		return -EIO;
+
+	/* we don't need to use inline_data strictly */
+	err = f2fs_convert_inline_inode(inode);
+	if (err)
+		return err;
+
+	file_accessed(file);
+	vma->vm_ops = &f2fs_file_vm_ops;
+	return 0;
+}
+
+static int f2fs_file_open(struct inode *inode, struct file *filp)
+{
+	int err = fscrypt_file_open(inode, filp);
+
+	if (err)
+		return err;
+
+	filp->f_mode |= FMODE_NOWAIT;
+
+	return dquot_file_open(inode, filp);
+}
+
+void truncate_data_blocks_range(struct dnode_of_data *dn, int count)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(dn->inode);
+	struct f2fs_node *raw_node;
+	int nr_free = 0, ofs = dn->ofs_in_node, len = count;
+	__le32 *addr;
+	int base = 0;
+
+	if (IS_INODE(dn->node_page) && f2fs_has_extra_attr(dn->inode))
+		base = get_extra_isize(dn->inode);
+
+	raw_node = F2FS_NODE(dn->node_page);
+	addr = blkaddr_in_node(raw_node) + base + ofs;
+
+	for (; count > 0; count--, addr++, dn->ofs_in_node++) {
+		block_t blkaddr = le32_to_cpu(*addr);
+		if (blkaddr == NULL_ADDR)
+			continue;
+
+		dn->data_blkaddr = NULL_ADDR;
+		set_data_blkaddr(dn);
+
+		if (__is_valid_data_blkaddr(blkaddr) &&
+			!f2fs_is_valid_blkaddr(sbi, blkaddr, DATA_GENERIC))
+			continue;
+
+		invalidate_blocks(sbi, blkaddr);
+		if (dn->ofs_in_node == 0 && IS_INODE(dn->node_page))
+			clear_inode_flag(dn->inode, FI_FIRST_BLOCK_WRITTEN);
+		nr_free++;
+	}
+
+	if (nr_free) {
+		pgoff_t fofs;
+		/*
+		 * once we invalidate valid blkaddr in range [ofs, ofs + count],
+		 * we will invalidate all blkaddr in the whole range.
+		 */
+		fofs = start_bidx_of_node(ofs_of_node(dn->node_page),
+							dn->inode) + ofs;
+		f2fs_update_extent_cache_range(dn, fofs, 0, len);
+		dec_valid_block_count(sbi, dn->inode, nr_free);
+	}
+	dn->ofs_in_node = ofs;
+
+	f2fs_update_time(sbi, REQ_TIME);
+	trace_f2fs_truncate_data_blocks_range(dn->inode, dn->nid,
+					 dn->ofs_in_node, nr_free);
+}
+
+void truncate_data_blocks(struct dnode_of_data *dn)
+{
+	truncate_data_blocks_range(dn, ADDRS_PER_BLOCK);
+}
+
+static int truncate_partial_data_page(struct inode *inode, u64 from,
+								bool cache_only)
+{
+	unsigned offset = from & (PAGE_SIZE - 1);
+	pgoff_t index = from >> PAGE_SHIFT;
+	struct address_space *mapping = inode->i_mapping;
+	struct page *page;
+
+	if (!offset && !cache_only)
+		return 0;
+
+	if (cache_only) {
+		page = find_lock_page(mapping, index);
+		if (page && PageUptodate(page))
+			goto truncate_out;
+		f2fs_put_page(page, 1);
+		return 0;
+	}
+
+	page = get_lock_data_page(inode, index, true);
+	if (IS_ERR(page))
+		return PTR_ERR(page) == -ENOENT ? 0 : PTR_ERR(page);
+truncate_out:
+	f2fs_wait_on_page_writeback(page, DATA, true);
+	zero_user(page, offset, PAGE_SIZE - offset);
+
+	/* An encrypted inode should have a key and truncate the last page. */
+	f2fs_bug_on(F2FS_I_SB(inode), cache_only && f2fs_encrypted_inode(inode));
+	if (!cache_only)
+		set_page_dirty(page);
+	f2fs_put_page(page, 1);
+	return 0;
+}
+
+int truncate_blocks(struct inode *inode, u64 from, bool lock)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct dnode_of_data dn;
+	pgoff_t free_from;
+	int count = 0, err = 0;
+	struct page *ipage;
+	bool truncate_page = false;
+
+	trace_f2fs_truncate_blocks_enter(inode, from);
+
+	free_from = (pgoff_t)F2FS_BLK_ALIGN(from);
+
+	if (free_from >= sbi->max_file_blocks)
+		goto free_partial;
+
+	if (lock)
+		f2fs_lock_op(sbi);
+
+	ipage = get_node_page(sbi, inode->i_ino);
+	if (IS_ERR(ipage)) {
+		err = PTR_ERR(ipage);
+		goto out;
+	}
+
+	if (f2fs_has_inline_data(inode)) {
+		truncate_inline_inode(inode, ipage, from);
+		f2fs_put_page(ipage, 1);
+		truncate_page = true;
+		goto out;
+	}
+
+	set_new_dnode(&dn, inode, ipage, NULL, 0);
+	err = get_dnode_of_data(&dn, free_from, LOOKUP_NODE_RA);
+	if (err) {
+		if (err == -ENOENT)
+			goto free_next;
+		goto out;
+	}
+
+	count = ADDRS_PER_PAGE(dn.node_page, inode);
+
+	count -= dn.ofs_in_node;
+	f2fs_bug_on(sbi, count < 0);
+
+	if (dn.ofs_in_node || IS_INODE(dn.node_page)) {
+		truncate_data_blocks_range(&dn, count);
+		free_from += count;
+	}
+
+	f2fs_put_dnode(&dn);
+free_next:
+	err = truncate_inode_blocks(inode, free_from);
+out:
+	if (lock)
+		f2fs_unlock_op(sbi);
+free_partial:
+	/* lastly zero out the first data page */
+	if (!err)
+		err = truncate_partial_data_page(inode, from, truncate_page);
+
+	trace_f2fs_truncate_blocks_exit(inode, err);
+	return err;
+}
+
+int f2fs_truncate(struct inode *inode)
+{
+	int err;
+
+	if (unlikely(f2fs_cp_error(F2FS_I_SB(inode))))
+		return -EIO;
+
+	if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
+				S_ISLNK(inode->i_mode)))
+		return 0;
+
+	trace_f2fs_truncate(inode);
+
+#ifdef CONFIG_F2FS_FAULT_INJECTION
+	if (time_to_inject(F2FS_I_SB(inode), FAULT_TRUNCATE)) {
+		f2fs_show_injection_info(FAULT_TRUNCATE);
+		return -EIO;
+	}
+#endif
+	/* we should check inline_data size */
+	if (!f2fs_may_inline_data(inode)) {
+		err = f2fs_convert_inline_inode(inode);
+		if (err)
+			return err;
+	}
+
+	err = truncate_blocks(inode, i_size_read(inode), true);
+	if (err)
+		return err;
+
+	inode->i_mtime = inode->i_ctime = current_time(inode);
+	f2fs_mark_inode_dirty_sync(inode, false);
+	return 0;
+}
+
+int f2fs_getattr(const struct path *path, struct kstat *stat,
+		 u32 request_mask, unsigned int query_flags)
+{
+	struct inode *inode = d_inode(path->dentry);
+	struct f2fs_inode_info *fi = F2FS_I(inode);
+	struct f2fs_inode *ri;
+	unsigned int flags;
+
+	if (f2fs_has_extra_attr(inode) &&
+			f2fs_sb_has_inode_crtime(inode->i_sb) &&
+			F2FS_FITS_IN_INODE(ri, fi->i_extra_isize, i_crtime)) {
+		stat->result_mask |= STATX_BTIME;
+		stat->btime.tv_sec = fi->i_crtime.tv_sec;
+		stat->btime.tv_nsec = fi->i_crtime.tv_nsec;
+	}
+
+	flags = fi->i_flags & (FS_FL_USER_VISIBLE | FS_PROJINHERIT_FL);
+	if (flags & FS_APPEND_FL)
+		stat->attributes |= STATX_ATTR_APPEND;
+	if (flags & FS_COMPR_FL)
+		stat->attributes |= STATX_ATTR_COMPRESSED;
+	if (f2fs_encrypted_inode(inode))
+		stat->attributes |= STATX_ATTR_ENCRYPTED;
+	if (flags & FS_IMMUTABLE_FL)
+		stat->attributes |= STATX_ATTR_IMMUTABLE;
+	if (flags & FS_NODUMP_FL)
+		stat->attributes |= STATX_ATTR_NODUMP;
+
+	stat->attributes_mask |= (STATX_ATTR_APPEND |
+				  STATX_ATTR_COMPRESSED |
+				  STATX_ATTR_ENCRYPTED |
+				  STATX_ATTR_IMMUTABLE |
+				  STATX_ATTR_NODUMP);
+
+	generic_fillattr(inode, stat);
+
+	/* we need to show initial sectors used for inline_data/dentries */
+	if ((S_ISREG(inode->i_mode) && f2fs_has_inline_data(inode)) ||
+					f2fs_has_inline_dentry(inode))
+		stat->blocks += (stat->size + 511) >> 9;
+
+	return 0;
+}
+
+#ifdef CONFIG_F2FS_FS_POSIX_ACL
+static void __setattr_copy(struct inode *inode, const struct iattr *attr)
+{
+	unsigned int ia_valid = attr->ia_valid;
+
+	if (ia_valid & ATTR_UID)
+		inode->i_uid = attr->ia_uid;
+	if (ia_valid & ATTR_GID)
+		inode->i_gid = attr->ia_gid;
+	if (ia_valid & ATTR_ATIME)
+		inode->i_atime = timespec_trunc(attr->ia_atime,
+						inode->i_sb->s_time_gran);
+	if (ia_valid & ATTR_MTIME)
+		inode->i_mtime = timespec_trunc(attr->ia_mtime,
+						inode->i_sb->s_time_gran);
+	if (ia_valid & ATTR_CTIME)
+		inode->i_ctime = timespec_trunc(attr->ia_ctime,
+						inode->i_sb->s_time_gran);
+	if (ia_valid & ATTR_MODE) {
+		umode_t mode = attr->ia_mode;
+
+		if (!in_group_p(inode->i_gid) && !capable(CAP_FSETID))
+			mode &= ~S_ISGID;
+		set_acl_inode(inode, mode);
+	}
+}
+#else
+#define __setattr_copy setattr_copy
+#endif
+
+int f2fs_setattr(struct dentry *dentry, struct iattr *attr)
+{
+	struct inode *inode = d_inode(dentry);
+	int err;
+	bool size_changed = false;
+
+	if (unlikely(f2fs_cp_error(F2FS_I_SB(inode))))
+		return -EIO;
+
+	err = setattr_prepare(dentry, attr);
+	if (err)
+		return err;
+
+	err = fscrypt_prepare_setattr(dentry, attr);
+	if (err)
+		return err;
+
+	if (is_quota_modification(inode, attr)) {
+		err = dquot_initialize(inode);
+		if (err)
+			return err;
+	}
+	if ((attr->ia_valid & ATTR_UID &&
+		!uid_eq(attr->ia_uid, inode->i_uid)) ||
+		(attr->ia_valid & ATTR_GID &&
+		!gid_eq(attr->ia_gid, inode->i_gid))) {
+		err = dquot_transfer(inode, attr);
+		if (err)
+			return err;
+	}
+
+	if (attr->ia_valid & ATTR_SIZE) {
+		if (attr->ia_size <= i_size_read(inode)) {
+			down_write(&F2FS_I(inode)->i_mmap_sem);
+			truncate_setsize(inode, attr->ia_size);
+			err = f2fs_truncate(inode);
+			up_write(&F2FS_I(inode)->i_mmap_sem);
+			if (err)
+				return err;
+		} else {
+			/*
+			 * do not trim all blocks after i_size if target size is
+			 * larger than i_size.
+			 */
+			down_write(&F2FS_I(inode)->i_mmap_sem);
+			truncate_setsize(inode, attr->ia_size);
+			up_write(&F2FS_I(inode)->i_mmap_sem);
+
+			/* should convert inline inode here */
+			if (!f2fs_may_inline_data(inode)) {
+				err = f2fs_convert_inline_inode(inode);
+				if (err)
+					return err;
+			}
+			inode->i_mtime = inode->i_ctime = current_time(inode);
+		}
+
+		down_write(&F2FS_I(inode)->i_sem);
+		F2FS_I(inode)->last_disk_size = i_size_read(inode);
+		up_write(&F2FS_I(inode)->i_sem);
+
+		size_changed = true;
+	}
+
+	__setattr_copy(inode, attr);
+
+	if (attr->ia_valid & ATTR_MODE) {
+		err = posix_acl_chmod(inode, get_inode_mode(inode));
+		if (err || is_inode_flag_set(inode, FI_ACL_MODE)) {
+			inode->i_mode = F2FS_I(inode)->i_acl_mode;
+			clear_inode_flag(inode, FI_ACL_MODE);
+		}
+	}
+
+	/* file size may changed here */
+	f2fs_mark_inode_dirty_sync(inode, size_changed);
+
+	/* inode change will produce dirty node pages flushed by checkpoint */
+	f2fs_balance_fs(F2FS_I_SB(inode), true);
+
+	return err;
+}
+
+const struct inode_operations f2fs_file_inode_operations = {
+	.getattr	= f2fs_getattr,
+	.setattr	= f2fs_setattr,
+	.get_acl	= f2fs_get_acl,
+	.set_acl	= f2fs_set_acl,
+#ifdef CONFIG_F2FS_FS_XATTR
+	.listxattr	= f2fs_listxattr,
+#endif
+	.fiemap		= f2fs_fiemap,
+};
+
+static int fill_zero(struct inode *inode, pgoff_t index,
+					loff_t start, loff_t len)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct page *page;
+
+	if (!len)
+		return 0;
+
+	f2fs_balance_fs(sbi, true);
+
+	f2fs_lock_op(sbi);
+	page = get_new_data_page(inode, NULL, index, false);
+	f2fs_unlock_op(sbi);
+
+	if (IS_ERR(page))
+		return PTR_ERR(page);
+
+	f2fs_wait_on_page_writeback(page, DATA, true);
+	zero_user(page, start, len);
+	set_page_dirty(page);
+	f2fs_put_page(page, 1);
+	return 0;
+}
+
+int truncate_hole(struct inode *inode, pgoff_t pg_start, pgoff_t pg_end)
+{
+	int err;
+
+	while (pg_start < pg_end) {
+		struct dnode_of_data dn;
+		pgoff_t end_offset, count;
+
+		set_new_dnode(&dn, inode, NULL, NULL, 0);
+		err = get_dnode_of_data(&dn, pg_start, LOOKUP_NODE);
+		if (err) {
+			if (err == -ENOENT) {
+				pg_start = get_next_page_offset(&dn, pg_start);
+				continue;
+			}
+			return err;
+		}
+
+		end_offset = ADDRS_PER_PAGE(dn.node_page, inode);
+		count = min(end_offset - dn.ofs_in_node, pg_end - pg_start);
+
+		f2fs_bug_on(F2FS_I_SB(inode), count == 0 || count > end_offset);
+
+		truncate_data_blocks_range(&dn, count);
+		f2fs_put_dnode(&dn);
+
+		pg_start += count;
+	}
+	return 0;
+}
+
+static int punch_hole(struct inode *inode, loff_t offset, loff_t len)
+{
+	pgoff_t pg_start, pg_end;
+	loff_t off_start, off_end;
+	int ret;
+
+	ret = f2fs_convert_inline_inode(inode);
+	if (ret)
+		return ret;
+
+	pg_start = ((unsigned long long) offset) >> PAGE_SHIFT;
+	pg_end = ((unsigned long long) offset + len) >> PAGE_SHIFT;
+
+	off_start = offset & (PAGE_SIZE - 1);
+	off_end = (offset + len) & (PAGE_SIZE - 1);
+
+	if (pg_start == pg_end) {
+		ret = fill_zero(inode, pg_start, off_start,
+						off_end - off_start);
+		if (ret)
+			return ret;
+	} else {
+		if (off_start) {
+			ret = fill_zero(inode, pg_start++, off_start,
+						PAGE_SIZE - off_start);
+			if (ret)
+				return ret;
+		}
+		if (off_end) {
+			ret = fill_zero(inode, pg_end, 0, off_end);
+			if (ret)
+				return ret;
+		}
+
+		if (pg_start < pg_end) {
+			struct address_space *mapping = inode->i_mapping;
+			loff_t blk_start, blk_end;
+			struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+
+			f2fs_balance_fs(sbi, true);
+
+			blk_start = (loff_t)pg_start << PAGE_SHIFT;
+			blk_end = (loff_t)pg_end << PAGE_SHIFT;
+			down_write(&F2FS_I(inode)->i_mmap_sem);
+			truncate_inode_pages_range(mapping, blk_start,
+					blk_end - 1);
+
+			f2fs_lock_op(sbi);
+			ret = truncate_hole(inode, pg_start, pg_end);
+			f2fs_unlock_op(sbi);
+			up_write(&F2FS_I(inode)->i_mmap_sem);
+		}
+	}
+
+	return ret;
+}
+
+static int __read_out_blkaddrs(struct inode *inode, block_t *blkaddr,
+				int *do_replace, pgoff_t off, pgoff_t len)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct dnode_of_data dn;
+	int ret, done, i;
+
+next_dnode:
+	set_new_dnode(&dn, inode, NULL, NULL, 0);
+	ret = get_dnode_of_data(&dn, off, LOOKUP_NODE_RA);
+	if (ret && ret != -ENOENT) {
+		return ret;
+	} else if (ret == -ENOENT) {
+		if (dn.max_level == 0)
+			return -ENOENT;
+		done = min((pgoff_t)ADDRS_PER_BLOCK - dn.ofs_in_node, len);
+		blkaddr += done;
+		do_replace += done;
+		goto next;
+	}
+
+	done = min((pgoff_t)ADDRS_PER_PAGE(dn.node_page, inode) -
+							dn.ofs_in_node, len);
+	for (i = 0; i < done; i++, blkaddr++, do_replace++, dn.ofs_in_node++) {
+		*blkaddr = datablock_addr(dn.inode,
+					dn.node_page, dn.ofs_in_node);
+		if (!is_checkpointed_data(sbi, *blkaddr)) {
+
+			if (test_opt(sbi, LFS)) {
+				f2fs_put_dnode(&dn);
+				return -ENOTSUPP;
+			}
+
+			/* do not invalidate this block address */
+			f2fs_update_data_blkaddr(&dn, NULL_ADDR);
+			*do_replace = 1;
+		}
+	}
+	f2fs_put_dnode(&dn);
+next:
+	len -= done;
+	off += done;
+	if (len)
+		goto next_dnode;
+	return 0;
+}
+
+static int __roll_back_blkaddrs(struct inode *inode, block_t *blkaddr,
+				int *do_replace, pgoff_t off, int len)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct dnode_of_data dn;
+	int ret, i;
+
+	for (i = 0; i < len; i++, do_replace++, blkaddr++) {
+		if (*do_replace == 0)
+			continue;
+
+		set_new_dnode(&dn, inode, NULL, NULL, 0);
+		ret = get_dnode_of_data(&dn, off + i, LOOKUP_NODE_RA);
+		if (ret) {
+			dec_valid_block_count(sbi, inode, 1);
+			invalidate_blocks(sbi, *blkaddr);
+		} else {
+			f2fs_update_data_blkaddr(&dn, *blkaddr);
+		}
+		f2fs_put_dnode(&dn);
+	}
+	return 0;
+}
+
+static int __clone_blkaddrs(struct inode *src_inode, struct inode *dst_inode,
+			block_t *blkaddr, int *do_replace,
+			pgoff_t src, pgoff_t dst, pgoff_t len, bool full)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(src_inode);
+	pgoff_t i = 0;
+	int ret;
+
+	while (i < len) {
+		if (blkaddr[i] == NULL_ADDR && !full) {
+			i++;
+			continue;
+		}
+
+		if (do_replace[i] || blkaddr[i] == NULL_ADDR) {
+			struct dnode_of_data dn;
+			struct node_info ni;
+			size_t new_size;
+			pgoff_t ilen;
+
+			set_new_dnode(&dn, dst_inode, NULL, NULL, 0);
+			ret = get_dnode_of_data(&dn, dst + i, ALLOC_NODE);
+			if (ret)
+				return ret;
+
+			get_node_info(sbi, dn.nid, &ni);
+			ilen = min((pgoff_t)
+				ADDRS_PER_PAGE(dn.node_page, dst_inode) -
+						dn.ofs_in_node, len - i);
+			do {
+				dn.data_blkaddr = datablock_addr(dn.inode,
+						dn.node_page, dn.ofs_in_node);
+				truncate_data_blocks_range(&dn, 1);
+
+				if (do_replace[i]) {
+					f2fs_i_blocks_write(src_inode,
+							1, false, false);
+					f2fs_i_blocks_write(dst_inode,
+							1, true, false);
+					f2fs_replace_block(sbi, &dn, dn.data_blkaddr,
+					blkaddr[i], ni.version, true, false);
+
+					do_replace[i] = 0;
+				}
+				dn.ofs_in_node++;
+				i++;
+				new_size = (loff_t)(dst + i) << PAGE_SHIFT;
+				if (dst_inode->i_size < new_size)
+					f2fs_i_size_write(dst_inode, new_size);
+			} while (--ilen && (do_replace[i] || blkaddr[i] == NULL_ADDR));
+
+			f2fs_put_dnode(&dn);
+		} else {
+			struct page *psrc, *pdst;
+
+			psrc = get_lock_data_page(src_inode, src + i, true);
+			if (IS_ERR(psrc))
+				return PTR_ERR(psrc);
+			pdst = get_new_data_page(dst_inode, NULL, dst + i,
+								true);
+			if (IS_ERR(pdst)) {
+				f2fs_put_page(psrc, 1);
+				return PTR_ERR(pdst);
+			}
+			f2fs_copy_page(psrc, pdst);
+			set_page_dirty(pdst);
+			f2fs_put_page(pdst, 1);
+			f2fs_put_page(psrc, 1);
+
+			ret = truncate_hole(src_inode, src + i, src + i + 1);
+			if (ret)
+				return ret;
+			i++;
+		}
+	}
+	return 0;
+}
+
+static int __exchange_data_block(struct inode *src_inode,
+			struct inode *dst_inode, pgoff_t src, pgoff_t dst,
+			pgoff_t len, bool full)
+{
+	block_t *src_blkaddr;
+	int *do_replace;
+	pgoff_t olen;
+	int ret;
+
+	while (len) {
+		olen = min((pgoff_t)4 * ADDRS_PER_BLOCK, len);
+
+		src_blkaddr = f2fs_kvzalloc(F2FS_I_SB(src_inode),
+					sizeof(block_t) * olen, GFP_KERNEL);
+		if (!src_blkaddr)
+			return -ENOMEM;
+
+		do_replace = f2fs_kvzalloc(F2FS_I_SB(src_inode),
+					sizeof(int) * olen, GFP_KERNEL);
+		if (!do_replace) {
+			kvfree(src_blkaddr);
+			return -ENOMEM;
+		}
+
+		ret = __read_out_blkaddrs(src_inode, src_blkaddr,
+					do_replace, src, olen);
+		if (ret)
+			goto roll_back;
+
+		ret = __clone_blkaddrs(src_inode, dst_inode, src_blkaddr,
+					do_replace, src, dst, olen, full);
+		if (ret)
+			goto roll_back;
+
+		src += olen;
+		dst += olen;
+		len -= olen;
+
+		kvfree(src_blkaddr);
+		kvfree(do_replace);
+	}
+	return 0;
+
+roll_back:
+	__roll_back_blkaddrs(src_inode, src_blkaddr, do_replace, src, len);
+	kvfree(src_blkaddr);
+	kvfree(do_replace);
+	return ret;
+}
+
+static int f2fs_do_collapse(struct inode *inode, pgoff_t start, pgoff_t end)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	pgoff_t nrpages = (i_size_read(inode) + PAGE_SIZE - 1) / PAGE_SIZE;
+	int ret;
+
+	f2fs_balance_fs(sbi, true);
+	f2fs_lock_op(sbi);
+
+	f2fs_drop_extent_tree(inode);
+
+	ret = __exchange_data_block(inode, inode, end, start, nrpages - end, true);
+	f2fs_unlock_op(sbi);
+	return ret;
+}
+
+static int f2fs_collapse_range(struct inode *inode, loff_t offset, loff_t len)
+{
+	pgoff_t pg_start, pg_end;
+	loff_t new_size;
+	int ret;
+
+	if (offset + len >= i_size_read(inode))
+		return -EINVAL;
+
+	/* collapse range should be aligned to block size of f2fs. */
+	if (offset & (F2FS_BLKSIZE - 1) || len & (F2FS_BLKSIZE - 1))
+		return -EINVAL;
+
+	ret = f2fs_convert_inline_inode(inode);
+	if (ret)
+		return ret;
+
+	pg_start = offset >> PAGE_SHIFT;
+	pg_end = (offset + len) >> PAGE_SHIFT;
+
+	/* avoid gc operation during block exchange */
+	down_write(&F2FS_I(inode)->dio_rwsem[WRITE]);
+
+	down_write(&F2FS_I(inode)->i_mmap_sem);
+	/* write out all dirty pages from offset */
+	ret = filemap_write_and_wait_range(inode->i_mapping, offset, LLONG_MAX);
+	if (ret)
+		goto out_unlock;
+
+	truncate_pagecache(inode, offset);
+
+	ret = f2fs_do_collapse(inode, pg_start, pg_end);
+	if (ret)
+		goto out_unlock;
+
+	/* write out all moved pages, if possible */
+	filemap_write_and_wait_range(inode->i_mapping, offset, LLONG_MAX);
+	truncate_pagecache(inode, offset);
+
+	new_size = i_size_read(inode) - len;
+	truncate_pagecache(inode, new_size);
+
+	ret = truncate_blocks(inode, new_size, true);
+	if (!ret)
+		f2fs_i_size_write(inode, new_size);
+out_unlock:
+	up_write(&F2FS_I(inode)->i_mmap_sem);
+	up_write(&F2FS_I(inode)->dio_rwsem[WRITE]);
+	return ret;
+}
+
+static int f2fs_do_zero_range(struct dnode_of_data *dn, pgoff_t start,
+								pgoff_t end)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(dn->inode);
+	pgoff_t index = start;
+	unsigned int ofs_in_node = dn->ofs_in_node;
+	blkcnt_t count = 0;
+	int ret;
+
+	for (; index < end; index++, dn->ofs_in_node++) {
+		if (datablock_addr(dn->inode, dn->node_page,
+					dn->ofs_in_node) == NULL_ADDR)
+			count++;
+	}
+
+	dn->ofs_in_node = ofs_in_node;
+	ret = reserve_new_blocks(dn, count);
+	if (ret)
+		return ret;
+
+	dn->ofs_in_node = ofs_in_node;
+	for (index = start; index < end; index++, dn->ofs_in_node++) {
+		dn->data_blkaddr = datablock_addr(dn->inode,
+					dn->node_page, dn->ofs_in_node);
+		/*
+		 * reserve_new_blocks will not guarantee entire block
+		 * allocation.
+		 */
+		if (dn->data_blkaddr == NULL_ADDR) {
+			ret = -ENOSPC;
+			break;
+		}
+		if (dn->data_blkaddr != NEW_ADDR) {
+			invalidate_blocks(sbi, dn->data_blkaddr);
+			dn->data_blkaddr = NEW_ADDR;
+			set_data_blkaddr(dn);
+		}
+	}
+
+	f2fs_update_extent_cache_range(dn, start, 0, index - start);
+
+	return ret;
+}
+
+static int f2fs_zero_range(struct inode *inode, loff_t offset, loff_t len,
+								int mode)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct address_space *mapping = inode->i_mapping;
+	pgoff_t index, pg_start, pg_end;
+	loff_t new_size = i_size_read(inode);
+	loff_t off_start, off_end;
+	int ret = 0;
+
+	ret = inode_newsize_ok(inode, (len + offset));
+	if (ret)
+		return ret;
+
+	ret = f2fs_convert_inline_inode(inode);
+	if (ret)
+		return ret;
+
+	down_write(&F2FS_I(inode)->i_mmap_sem);
+	ret = filemap_write_and_wait_range(mapping, offset, offset + len - 1);
+	if (ret)
+		goto out_sem;
+
+	truncate_pagecache_range(inode, offset, offset + len - 1);
+
+	pg_start = ((unsigned long long) offset) >> PAGE_SHIFT;
+	pg_end = ((unsigned long long) offset + len) >> PAGE_SHIFT;
+
+	off_start = offset & (PAGE_SIZE - 1);
+	off_end = (offset + len) & (PAGE_SIZE - 1);
+
+	if (pg_start == pg_end) {
+		ret = fill_zero(inode, pg_start, off_start,
+						off_end - off_start);
+		if (ret)
+			goto out_sem;
+
+		new_size = max_t(loff_t, new_size, offset + len);
+	} else {
+		if (off_start) {
+			ret = fill_zero(inode, pg_start++, off_start,
+						PAGE_SIZE - off_start);
+			if (ret)
+				goto out_sem;
+
+			new_size = max_t(loff_t, new_size,
+					(loff_t)pg_start << PAGE_SHIFT);
+		}
+
+		for (index = pg_start; index < pg_end;) {
+			struct dnode_of_data dn;
+			unsigned int end_offset;
+			pgoff_t end;
+
+			f2fs_lock_op(sbi);
+
+			set_new_dnode(&dn, inode, NULL, NULL, 0);
+			ret = get_dnode_of_data(&dn, index, ALLOC_NODE);
+			if (ret) {
+				f2fs_unlock_op(sbi);
+				goto out;
+			}
+
+			end_offset = ADDRS_PER_PAGE(dn.node_page, inode);
+			end = min(pg_end, end_offset - dn.ofs_in_node + index);
+
+			ret = f2fs_do_zero_range(&dn, index, end);
+			f2fs_put_dnode(&dn);
+			f2fs_unlock_op(sbi);
+
+			f2fs_balance_fs(sbi, dn.node_changed);
+
+			if (ret)
+				goto out;
+
+			index = end;
+			new_size = max_t(loff_t, new_size,
+					(loff_t)index << PAGE_SHIFT);
+		}
+
+		if (off_end) {
+			ret = fill_zero(inode, pg_end, 0, off_end);
+			if (ret)
+				goto out;
+
+			new_size = max_t(loff_t, new_size, offset + len);
+		}
+	}
+
+out:
+	if (new_size > i_size_read(inode)) {
+		if (mode & FALLOC_FL_KEEP_SIZE)
+			file_set_keep_isize(inode);
+		else
+			f2fs_i_size_write(inode, new_size);
+	}
+out_sem:
+	up_write(&F2FS_I(inode)->i_mmap_sem);
+
+	return ret;
+}
+
+static int f2fs_insert_range(struct inode *inode, loff_t offset, loff_t len)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	pgoff_t nr, pg_start, pg_end, delta, idx;
+	loff_t new_size;
+	int ret = 0;
+
+	new_size = i_size_read(inode) + len;
+	ret = inode_newsize_ok(inode, new_size);
+	if (ret)
+		return ret;
+
+	if (offset >= i_size_read(inode))
+		return -EINVAL;
+
+	/* insert range should be aligned to block size of f2fs. */
+	if (offset & (F2FS_BLKSIZE - 1) || len & (F2FS_BLKSIZE - 1))
+		return -EINVAL;
+
+	ret = f2fs_convert_inline_inode(inode);
+	if (ret)
+		return ret;
+
+	f2fs_balance_fs(sbi, true);
+
+	/* avoid gc operation during block exchange */
+	down_write(&F2FS_I(inode)->dio_rwsem[WRITE]);
+
+	down_write(&F2FS_I(inode)->i_mmap_sem);
+	ret = truncate_blocks(inode, i_size_read(inode), true);
+	if (ret)
+		goto out;
+
+	/* write out all dirty pages from offset */
+	ret = filemap_write_and_wait_range(inode->i_mapping, offset, LLONG_MAX);
+	if (ret)
+		goto out;
+
+	truncate_pagecache(inode, offset);
+
+	pg_start = offset >> PAGE_SHIFT;
+	pg_end = (offset + len) >> PAGE_SHIFT;
+	delta = pg_end - pg_start;
+	idx = (i_size_read(inode) + PAGE_SIZE - 1) / PAGE_SIZE;
+
+	while (!ret && idx > pg_start) {
+		nr = idx - pg_start;
+		if (nr > delta)
+			nr = delta;
+		idx -= nr;
+
+		f2fs_lock_op(sbi);
+		f2fs_drop_extent_tree(inode);
+
+		ret = __exchange_data_block(inode, inode, idx,
+					idx + delta, nr, false);
+		f2fs_unlock_op(sbi);
+	}
+
+	/* write out all moved pages, if possible */
+	filemap_write_and_wait_range(inode->i_mapping, offset, LLONG_MAX);
+	truncate_pagecache(inode, offset);
+
+	if (!ret)
+		f2fs_i_size_write(inode, new_size);
+out:
+	up_write(&F2FS_I(inode)->i_mmap_sem);
+	up_write(&F2FS_I(inode)->dio_rwsem[WRITE]);
+	return ret;
+}
+
+static int expand_inode_data(struct inode *inode, loff_t offset,
+					loff_t len, int mode)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct f2fs_map_blocks map = { .m_next_pgofs = NULL,
+			.m_next_extent = NULL, .m_seg_type = NO_CHECK_TYPE };
+	pgoff_t pg_end;
+	loff_t new_size = i_size_read(inode);
+	loff_t off_end;
+	int err;
+
+	err = inode_newsize_ok(inode, (len + offset));
+	if (err)
+		return err;
+
+	err = f2fs_convert_inline_inode(inode);
+	if (err)
+		return err;
+
+	f2fs_balance_fs(sbi, true);
+
+	pg_end = ((unsigned long long)offset + len) >> PAGE_SHIFT;
+	off_end = (offset + len) & (PAGE_SIZE - 1);
+
+	map.m_lblk = ((unsigned long long)offset) >> PAGE_SHIFT;
+	map.m_len = pg_end - map.m_lblk;
+	if (off_end)
+		map.m_len++;
+
+	err = f2fs_map_blocks(inode, &map, 1, F2FS_GET_BLOCK_PRE_AIO);
+	if (err) {
+		pgoff_t last_off;
+
+		if (!map.m_len)
+			return err;
+
+		last_off = map.m_lblk + map.m_len - 1;
+
+		/* update new size to the failed position */
+		new_size = (last_off == pg_end) ? offset + len:
+					(loff_t)(last_off + 1) << PAGE_SHIFT;
+	} else {
+		new_size = ((loff_t)pg_end << PAGE_SHIFT) + off_end;
+	}
+
+	if (new_size > i_size_read(inode)) {
+		if (mode & FALLOC_FL_KEEP_SIZE)
+			file_set_keep_isize(inode);
+		else
+			f2fs_i_size_write(inode, new_size);
+	}
+
+	return err;
+}
+
+static long f2fs_fallocate(struct file *file, int mode,
+				loff_t offset, loff_t len)
+{
+	struct inode *inode = file_inode(file);
+	long ret = 0;
+
+	if (unlikely(f2fs_cp_error(F2FS_I_SB(inode))))
+		return -EIO;
+
+	/* f2fs only support ->fallocate for regular file */
+	if (!S_ISREG(inode->i_mode))
+		return -EINVAL;
+
+	if (f2fs_encrypted_inode(inode) &&
+		(mode & (FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_INSERT_RANGE)))
+		return -EOPNOTSUPP;
+
+	if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE |
+			FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_ZERO_RANGE |
+			FALLOC_FL_INSERT_RANGE))
+		return -EOPNOTSUPP;
+
+	inode_lock(inode);
+
+	if (mode & FALLOC_FL_PUNCH_HOLE) {
+		if (offset >= inode->i_size)
+			goto out;
+
+		ret = punch_hole(inode, offset, len);
+	} else if (mode & FALLOC_FL_COLLAPSE_RANGE) {
+		ret = f2fs_collapse_range(inode, offset, len);
+	} else if (mode & FALLOC_FL_ZERO_RANGE) {
+		ret = f2fs_zero_range(inode, offset, len, mode);
+	} else if (mode & FALLOC_FL_INSERT_RANGE) {
+		ret = f2fs_insert_range(inode, offset, len);
+	} else {
+		ret = expand_inode_data(inode, offset, len, mode);
+	}
+
+	if (!ret) {
+		inode->i_mtime = inode->i_ctime = current_time(inode);
+		f2fs_mark_inode_dirty_sync(inode, false);
+		f2fs_update_time(F2FS_I_SB(inode), REQ_TIME);
+	}
+
+out:
+	inode_unlock(inode);
+
+	trace_f2fs_fallocate(inode, mode, offset, len, ret);
+	return ret;
+}
+
+static int f2fs_release_file(struct inode *inode, struct file *filp)
+{
+	/*
+	 * f2fs_relase_file is called at every close calls. So we should
+	 * not drop any inmemory pages by close called by other process.
+	 */
+	if (!(filp->f_mode & FMODE_WRITE) ||
+			atomic_read(&inode->i_writecount) != 1)
+		return 0;
+
+	/* some remained atomic pages should discarded */
+	if (f2fs_is_atomic_file(inode))
+		drop_inmem_pages(inode);
+	if (f2fs_is_volatile_file(inode)) {
+		clear_inode_flag(inode, FI_VOLATILE_FILE);
+		stat_dec_volatile_write(inode);
+		set_inode_flag(inode, FI_DROP_CACHE);
+		filemap_fdatawrite(inode->i_mapping);
+		clear_inode_flag(inode, FI_DROP_CACHE);
+	}
+	return 0;
+}
+
+static int f2fs_file_flush(struct file *file, fl_owner_t id)
+{
+	struct inode *inode = file_inode(file);
+
+	/*
+	 * If the process doing a transaction is crashed, we should do
+	 * roll-back. Otherwise, other reader/write can see corrupted database
+	 * until all the writers close its file. Since this should be done
+	 * before dropping file lock, it needs to do in ->flush.
+	 */
+	if (f2fs_is_atomic_file(inode) &&
+			F2FS_I(inode)->inmem_task == current)
+		drop_inmem_pages(inode);
+	return 0;
+}
+
+static int f2fs_ioc_getflags(struct file *filp, unsigned long arg)
+{
+	struct inode *inode = file_inode(filp);
+	struct f2fs_inode_info *fi = F2FS_I(inode);
+	unsigned int flags = fi->i_flags &
+			(FS_FL_USER_VISIBLE | FS_PROJINHERIT_FL);
+	return put_user(flags, (int __user *)arg);
+}
+
+static int __f2fs_ioc_setflags(struct inode *inode, unsigned int flags)
+{
+	struct f2fs_inode_info *fi = F2FS_I(inode);
+	unsigned int oldflags;
+
+	/* Is it quota file? Do not allow user to mess with it */
+	if (IS_NOQUOTA(inode))
+		return -EPERM;
+
+	flags = f2fs_mask_flags(inode->i_mode, flags);
+
+	oldflags = fi->i_flags;
+
+	if ((flags ^ oldflags) & (FS_APPEND_FL | FS_IMMUTABLE_FL))
+		if (!capable(CAP_LINUX_IMMUTABLE))
+			return -EPERM;
+
+	flags = flags & (FS_FL_USER_MODIFIABLE | FS_PROJINHERIT_FL);
+	flags |= oldflags & ~(FS_FL_USER_MODIFIABLE | FS_PROJINHERIT_FL);
+	fi->i_flags = flags;
+
+	if (fi->i_flags & FS_PROJINHERIT_FL)
+		set_inode_flag(inode, FI_PROJ_INHERIT);
+	else
+		clear_inode_flag(inode, FI_PROJ_INHERIT);
+
+	inode->i_ctime = current_time(inode);
+	f2fs_set_inode_flags(inode);
+	f2fs_mark_inode_dirty_sync(inode, true);
+	return 0;
+}
+
+static int f2fs_ioc_setflags(struct file *filp, unsigned long arg)
+{
+	struct inode *inode = file_inode(filp);
+	unsigned int flags;
+	int ret;
+
+	if (!inode_owner_or_capable(inode))
+		return -EACCES;
+
+	if (get_user(flags, (int __user *)arg))
+		return -EFAULT;
+
+	ret = mnt_want_write_file(filp);
+	if (ret)
+		return ret;
+
+	inode_lock(inode);
+
+	ret = __f2fs_ioc_setflags(inode, flags);
+
+	inode_unlock(inode);
+	mnt_drop_write_file(filp);
+	return ret;
+}
+
+static int f2fs_ioc_getversion(struct file *filp, unsigned long arg)
+{
+	struct inode *inode = file_inode(filp);
+
+	return put_user(inode->i_generation, (int __user *)arg);
+}
+
+static int f2fs_ioc_start_atomic_write(struct file *filp)
+{
+	struct inode *inode = file_inode(filp);
+	int ret;
+
+	if (!inode_owner_or_capable(inode))
+		return -EACCES;
+
+	if (!S_ISREG(inode->i_mode))
+		return -EINVAL;
+
+	ret = mnt_want_write_file(filp);
+	if (ret)
+		return ret;
+
+	inode_lock(inode);
+
+	down_write(&F2FS_I(inode)->dio_rwsem[WRITE]);
+
+	if (f2fs_is_atomic_file(inode))
+		goto out;
+
+	ret = f2fs_convert_inline_inode(inode);
+	if (ret)
+		goto out;
+
+	set_inode_flag(inode, FI_ATOMIC_FILE);
+	set_inode_flag(inode, FI_HOT_DATA);
+	f2fs_update_time(F2FS_I_SB(inode), REQ_TIME);
+
+	if (!get_dirty_pages(inode))
+		goto inc_stat;
+
+	f2fs_msg(F2FS_I_SB(inode)->sb, KERN_WARNING,
+		"Unexpected flush for atomic writes: ino=%lu, npages=%u",
+					inode->i_ino, get_dirty_pages(inode));
+	ret = filemap_write_and_wait_range(inode->i_mapping, 0, LLONG_MAX);
+	if (ret) {
+		clear_inode_flag(inode, FI_ATOMIC_FILE);
+		clear_inode_flag(inode, FI_HOT_DATA);
+		goto out;
+	}
+
+inc_stat:
+	F2FS_I(inode)->inmem_task = current;
+	stat_inc_atomic_write(inode);
+	stat_update_max_atomic_write(inode);
+out:
+	up_write(&F2FS_I(inode)->dio_rwsem[WRITE]);
+	inode_unlock(inode);
+	mnt_drop_write_file(filp);
+	return ret;
+}
+
+static int f2fs_ioc_commit_atomic_write(struct file *filp)
+{
+	struct inode *inode = file_inode(filp);
+	int ret;
+
+	if (!inode_owner_or_capable(inode))
+		return -EACCES;
+
+	ret = mnt_want_write_file(filp);
+	if (ret)
+		return ret;
+
+	inode_lock(inode);
+
+	down_write(&F2FS_I(inode)->dio_rwsem[WRITE]);
+
+	if (f2fs_is_volatile_file(inode))
+		goto err_out;
+
+	if (f2fs_is_atomic_file(inode)) {
+		ret = commit_inmem_pages(inode);
+		if (ret)
+			goto err_out;
+
+		ret = f2fs_do_sync_file(filp, 0, LLONG_MAX, 0, true);
+		if (!ret) {
+			clear_inode_flag(inode, FI_ATOMIC_FILE);
+			clear_inode_flag(inode, FI_HOT_DATA);
+			stat_dec_atomic_write(inode);
+		}
+	} else {
+		ret = f2fs_do_sync_file(filp, 0, LLONG_MAX, 1, false);
+	}
+err_out:
+	up_write(&F2FS_I(inode)->dio_rwsem[WRITE]);
+	inode_unlock(inode);
+	mnt_drop_write_file(filp);
+	return ret;
+}
+
+static int f2fs_ioc_start_volatile_write(struct file *filp)
+{
+	struct inode *inode = file_inode(filp);
+	int ret;
+
+	if (!inode_owner_or_capable(inode))
+		return -EACCES;
+
+	if (!S_ISREG(inode->i_mode))
+		return -EINVAL;
+
+	ret = mnt_want_write_file(filp);
+	if (ret)
+		return ret;
+
+	inode_lock(inode);
+
+	if (f2fs_is_volatile_file(inode))
+		goto out;
+
+	ret = f2fs_convert_inline_inode(inode);
+	if (ret)
+		goto out;
+
+	stat_inc_volatile_write(inode);
+	stat_update_max_volatile_write(inode);
+
+	set_inode_flag(inode, FI_VOLATILE_FILE);
+	f2fs_update_time(F2FS_I_SB(inode), REQ_TIME);
+out:
+	inode_unlock(inode);
+	mnt_drop_write_file(filp);
+	return ret;
+}
+
+static int f2fs_ioc_release_volatile_write(struct file *filp)
+{
+	struct inode *inode = file_inode(filp);
+	int ret;
+
+	if (!inode_owner_or_capable(inode))
+		return -EACCES;
+
+	ret = mnt_want_write_file(filp);
+	if (ret)
+		return ret;
+
+	inode_lock(inode);
+
+	if (!f2fs_is_volatile_file(inode))
+		goto out;
+
+	if (!f2fs_is_first_block_written(inode)) {
+		ret = truncate_partial_data_page(inode, 0, true);
+		goto out;
+	}
+
+	ret = punch_hole(inode, 0, F2FS_BLKSIZE);
+out:
+	inode_unlock(inode);
+	mnt_drop_write_file(filp);
+	return ret;
+}
+
+static int f2fs_ioc_abort_volatile_write(struct file *filp)
+{
+	struct inode *inode = file_inode(filp);
+	int ret;
+
+	if (!inode_owner_or_capable(inode))
+		return -EACCES;
+
+	ret = mnt_want_write_file(filp);
+	if (ret)
+		return ret;
+
+	inode_lock(inode);
+
+	if (f2fs_is_atomic_file(inode))
+		drop_inmem_pages(inode);
+	if (f2fs_is_volatile_file(inode)) {
+		clear_inode_flag(inode, FI_VOLATILE_FILE);
+		stat_dec_volatile_write(inode);
+		ret = f2fs_do_sync_file(filp, 0, LLONG_MAX, 0, true);
+	}
+
+	inode_unlock(inode);
+
+	mnt_drop_write_file(filp);
+	f2fs_update_time(F2FS_I_SB(inode), REQ_TIME);
+	return ret;
+}
+
+static int f2fs_ioc_shutdown(struct file *filp, unsigned long arg)
+{
+	struct inode *inode = file_inode(filp);
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct super_block *sb = sbi->sb;
+	__u32 in;
+	int ret = 0;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
+	if (get_user(in, (__u32 __user *)arg))
+		return -EFAULT;
+
+	if (in != F2FS_GOING_DOWN_FULLSYNC) {
+		ret = mnt_want_write_file(filp);
+		if (ret)
+			return ret;
+	}
+
+	switch (in) {
+	case F2FS_GOING_DOWN_FULLSYNC:
+		sb = freeze_bdev(sb->s_bdev);
+		if (IS_ERR(sb)) {
+			ret = PTR_ERR(sb);
+			goto out;
+		}
+		if (sb) {
+			f2fs_stop_checkpoint(sbi, false);
+			thaw_bdev(sb->s_bdev, sb);
+		}
+		break;
+	case F2FS_GOING_DOWN_METASYNC:
+		/* do checkpoint only */
+		ret = f2fs_sync_fs(sb, 1);
+		if (ret)
+			goto out;
+		f2fs_stop_checkpoint(sbi, false);
+		break;
+	case F2FS_GOING_DOWN_NOSYNC:
+		f2fs_stop_checkpoint(sbi, false);
+		break;
+	case F2FS_GOING_DOWN_METAFLUSH:
+		sync_meta_pages(sbi, META, LONG_MAX, FS_META_IO);
+		f2fs_stop_checkpoint(sbi, false);
+		break;
+	default:
+		ret = -EINVAL;
+		goto out;
+	}
+
+	stop_gc_thread(sbi);
+	stop_discard_thread(sbi);
+
+	drop_discard_cmd(sbi);
+	clear_opt(sbi, DISCARD);
+
+	f2fs_update_time(sbi, REQ_TIME);
+out:
+	if (in != F2FS_GOING_DOWN_FULLSYNC)
+		mnt_drop_write_file(filp);
+	return ret;
+}
+
+static int f2fs_ioc_fitrim(struct file *filp, unsigned long arg)
+{
+	struct inode *inode = file_inode(filp);
+	struct super_block *sb = inode->i_sb;
+	struct request_queue *q = bdev_get_queue(sb->s_bdev);
+	struct fstrim_range range;
+	int ret;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
+	if (!blk_queue_discard(q))
+		return -EOPNOTSUPP;
+
+	if (copy_from_user(&range, (struct fstrim_range __user *)arg,
+				sizeof(range)))
+		return -EFAULT;
+
+	ret = mnt_want_write_file(filp);
+	if (ret)
+		return ret;
+
+	range.minlen = max((unsigned int)range.minlen,
+				q->limits.discard_granularity);
+	ret = f2fs_trim_fs(F2FS_SB(sb), &range);
+	mnt_drop_write_file(filp);
+	if (ret < 0)
+		return ret;
+
+	if (copy_to_user((struct fstrim_range __user *)arg, &range,
+				sizeof(range)))
+		return -EFAULT;
+	f2fs_update_time(F2FS_I_SB(inode), REQ_TIME);
+	return 0;
+}
+
+static bool uuid_is_nonzero(__u8 u[16])
+{
+	int i;
+
+	for (i = 0; i < 16; i++)
+		if (u[i])
+			return true;
+	return false;
+}
+
+static int f2fs_ioc_set_encryption_policy(struct file *filp, unsigned long arg)
+{
+	struct inode *inode = file_inode(filp);
+
+	if (!f2fs_sb_has_encrypt(inode->i_sb))
+		return -EOPNOTSUPP;
+
+	f2fs_update_time(F2FS_I_SB(inode), REQ_TIME);
+
+	return fscrypt_ioctl_set_policy(filp, (const void __user *)arg);
+}
+
+static int f2fs_ioc_get_encryption_policy(struct file *filp, unsigned long arg)
+{
+	if (!f2fs_sb_has_encrypt(file_inode(filp)->i_sb))
+		return -EOPNOTSUPP;
+	return fscrypt_ioctl_get_policy(filp, (void __user *)arg);
+}
+
+static int f2fs_ioc_get_encryption_pwsalt(struct file *filp, unsigned long arg)
+{
+	struct inode *inode = file_inode(filp);
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	int err;
+
+	if (!f2fs_sb_has_encrypt(inode->i_sb))
+		return -EOPNOTSUPP;
+
+	err = mnt_want_write_file(filp);
+	if (err)
+		return err;
+
+	down_write(&sbi->sb_lock);
+
+	if (uuid_is_nonzero(sbi->raw_super->encrypt_pw_salt))
+		goto got_it;
+
+	/* update superblock with uuid */
+	generate_random_uuid(sbi->raw_super->encrypt_pw_salt);
+
+	err = f2fs_commit_super(sbi, false);
+	if (err) {
+		/* undo new data */
+		memset(sbi->raw_super->encrypt_pw_salt, 0, 16);
+		goto out_err;
+	}
+got_it:
+	if (copy_to_user((__u8 __user *)arg, sbi->raw_super->encrypt_pw_salt,
+									16))
+		err = -EFAULT;
+out_err:
+	up_write(&sbi->sb_lock);
+	mnt_drop_write_file(filp);
+	return err;
+}
+
+static int f2fs_ioc_gc(struct file *filp, unsigned long arg)
+{
+	struct inode *inode = file_inode(filp);
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	__u32 sync;
+	int ret;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
+	if (get_user(sync, (__u32 __user *)arg))
+		return -EFAULT;
+
+	if (f2fs_readonly(sbi->sb))
+		return -EROFS;
+
+	ret = mnt_want_write_file(filp);
+	if (ret)
+		return ret;
+
+	if (!sync) {
+		if (!mutex_trylock(&sbi->gc_mutex)) {
+			ret = -EBUSY;
+			goto out;
+		}
+	} else {
+		mutex_lock(&sbi->gc_mutex);
+	}
+
+	ret = f2fs_gc(sbi, sync, true, NULL_SEGNO);
+out:
+	mnt_drop_write_file(filp);
+	return ret;
+}
+
+static int f2fs_ioc_gc_range(struct file *filp, unsigned long arg)
+{
+	struct inode *inode = file_inode(filp);
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct f2fs_gc_range range;
+	u64 end;
+	int ret;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
+	if (copy_from_user(&range, (struct f2fs_gc_range __user *)arg,
+							sizeof(range)))
+		return -EFAULT;
+
+	if (f2fs_readonly(sbi->sb))
+		return -EROFS;
+
+	ret = mnt_want_write_file(filp);
+	if (ret)
+		return ret;
+
+	end = range.start + range.len;
+	if (range.start < MAIN_BLKADDR(sbi) || end >= MAX_BLKADDR(sbi)) {
+		ret = -EINVAL;
+		goto out;
+	}
+do_more:
+	if (!range.sync) {
+		if (!mutex_trylock(&sbi->gc_mutex)) {
+			ret = -EBUSY;
+			goto out;
+		}
+	} else {
+		mutex_lock(&sbi->gc_mutex);
+	}
+
+	ret = f2fs_gc(sbi, range.sync, true, GET_SEGNO(sbi, range.start));
+	range.start += BLKS_PER_SEC(sbi);
+	if (range.start <= end)
+		goto do_more;
+out:
+	mnt_drop_write_file(filp);
+	return ret;
+}
+
+static int f2fs_ioc_write_checkpoint(struct file *filp, unsigned long arg)
+{
+	struct inode *inode = file_inode(filp);
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	int ret;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
+	if (f2fs_readonly(sbi->sb))
+		return -EROFS;
+
+	ret = mnt_want_write_file(filp);
+	if (ret)
+		return ret;
+
+	ret = f2fs_sync_fs(sbi->sb, 1);
+
+	mnt_drop_write_file(filp);
+	return ret;
+}
+
+static int f2fs_defragment_range(struct f2fs_sb_info *sbi,
+					struct file *filp,
+					struct f2fs_defragment *range)
+{
+	struct inode *inode = file_inode(filp);
+	struct f2fs_map_blocks map = { .m_next_extent = NULL,
+					.m_seg_type = NO_CHECK_TYPE };
+	struct extent_info ei = {0,0,0};
+	pgoff_t pg_start, pg_end, next_pgofs;
+	unsigned int blk_per_seg = sbi->blocks_per_seg;
+	unsigned int total = 0, sec_num;
+	block_t blk_end = 0;
+	bool fragmented = false;
+	int err;
+
+	/* if in-place-update policy is enabled, don't waste time here */
+	if (should_update_inplace(inode, NULL))
+		return -EINVAL;
+
+	pg_start = range->start >> PAGE_SHIFT;
+	pg_end = (range->start + range->len) >> PAGE_SHIFT;
+
+	f2fs_balance_fs(sbi, true);
+
+	inode_lock(inode);
+
+	/* writeback all dirty pages in the range */
+	err = filemap_write_and_wait_range(inode->i_mapping, range->start,
+						range->start + range->len - 1);
+	if (err)
+		goto out;
+
+	/*
+	 * lookup mapping info in extent cache, skip defragmenting if physical
+	 * block addresses are continuous.
+	 */
+	if (f2fs_lookup_extent_cache(inode, pg_start, &ei)) {
+		if (ei.fofs + ei.len >= pg_end)
+			goto out;
+	}
+
+	map.m_lblk = pg_start;
+	map.m_next_pgofs = &next_pgofs;
+
+	/*
+	 * lookup mapping info in dnode page cache, skip defragmenting if all
+	 * physical block addresses are continuous even if there are hole(s)
+	 * in logical blocks.
+	 */
+	while (map.m_lblk < pg_end) {
+		map.m_len = pg_end - map.m_lblk;
+		err = f2fs_map_blocks(inode, &map, 0, F2FS_GET_BLOCK_DEFAULT);
+		if (err)
+			goto out;
+
+		if (!(map.m_flags & F2FS_MAP_FLAGS)) {
+			map.m_lblk = next_pgofs;
+			continue;
+		}
+
+		if (blk_end && blk_end != map.m_pblk)
+			fragmented = true;
+
+		/* record total count of block that we're going to move */
+		total += map.m_len;
+
+		blk_end = map.m_pblk + map.m_len;
+
+		map.m_lblk += map.m_len;
+	}
+
+	if (!fragmented)
+		goto out;
+
+	sec_num = (total + BLKS_PER_SEC(sbi) - 1) / BLKS_PER_SEC(sbi);
+
+	/*
+	 * make sure there are enough free section for LFS allocation, this can
+	 * avoid defragment running in SSR mode when free section are allocated
+	 * intensively
+	 */
+	if (has_not_enough_free_secs(sbi, 0, sec_num)) {
+		err = -EAGAIN;
+		goto out;
+	}
+
+	map.m_lblk = pg_start;
+	map.m_len = pg_end - pg_start;
+	total = 0;
+
+	while (map.m_lblk < pg_end) {
+		pgoff_t idx;
+		int cnt = 0;
+
+do_map:
+		map.m_len = pg_end - map.m_lblk;
+		err = f2fs_map_blocks(inode, &map, 0, F2FS_GET_BLOCK_DEFAULT);
+		if (err)
+			goto clear_out;
+
+		if (!(map.m_flags & F2FS_MAP_FLAGS)) {
+			map.m_lblk = next_pgofs;
+			continue;
+		}
+
+		set_inode_flag(inode, FI_DO_DEFRAG);
+
+		idx = map.m_lblk;
+		while (idx < map.m_lblk + map.m_len && cnt < blk_per_seg) {
+			struct page *page;
+
+			page = get_lock_data_page(inode, idx, true);
+			if (IS_ERR(page)) {
+				err = PTR_ERR(page);
+				goto clear_out;
+			}
+
+			set_page_dirty(page);
+			f2fs_put_page(page, 1);
+
+			idx++;
+			cnt++;
+			total++;
+		}
+
+		map.m_lblk = idx;
+
+		if (idx < pg_end && cnt < blk_per_seg)
+			goto do_map;
+
+		clear_inode_flag(inode, FI_DO_DEFRAG);
+
+		err = filemap_fdatawrite(inode->i_mapping);
+		if (err)
+			goto out;
+	}
+clear_out:
+	clear_inode_flag(inode, FI_DO_DEFRAG);
+out:
+	inode_unlock(inode);
+	if (!err)
+		range->len = (u64)total << PAGE_SHIFT;
+	return err;
+}
+
+static int f2fs_ioc_defragment(struct file *filp, unsigned long arg)
+{
+	struct inode *inode = file_inode(filp);
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct f2fs_defragment range;
+	int err;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
+	if (!S_ISREG(inode->i_mode) || f2fs_is_atomic_file(inode))
+		return -EINVAL;
+
+	if (f2fs_readonly(sbi->sb))
+		return -EROFS;
+
+	if (copy_from_user(&range, (struct f2fs_defragment __user *)arg,
+							sizeof(range)))
+		return -EFAULT;
+
+	/* verify alignment of offset & size */
+	if (range.start & (F2FS_BLKSIZE - 1) || range.len & (F2FS_BLKSIZE - 1))
+		return -EINVAL;
+
+	if (unlikely((range.start + range.len) >> PAGE_SHIFT >
+					sbi->max_file_blocks))
+		return -EINVAL;
+
+	err = mnt_want_write_file(filp);
+	if (err)
+		return err;
+
+	err = f2fs_defragment_range(sbi, filp, &range);
+	mnt_drop_write_file(filp);
+
+	f2fs_update_time(sbi, REQ_TIME);
+	if (err < 0)
+		return err;
+
+	if (copy_to_user((struct f2fs_defragment __user *)arg, &range,
+							sizeof(range)))
+		return -EFAULT;
+
+	return 0;
+}
+
+static int f2fs_move_file_range(struct file *file_in, loff_t pos_in,
+			struct file *file_out, loff_t pos_out, size_t len)
+{
+	struct inode *src = file_inode(file_in);
+	struct inode *dst = file_inode(file_out);
+	struct f2fs_sb_info *sbi = F2FS_I_SB(src);
+	size_t olen = len, dst_max_i_size = 0;
+	size_t dst_osize;
+	int ret;
+
+	if (file_in->f_path.mnt != file_out->f_path.mnt ||
+				src->i_sb != dst->i_sb)
+		return -EXDEV;
+
+	if (unlikely(f2fs_readonly(src->i_sb)))
+		return -EROFS;
+
+	if (!S_ISREG(src->i_mode) || !S_ISREG(dst->i_mode))
+		return -EINVAL;
+
+	if (f2fs_encrypted_inode(src) || f2fs_encrypted_inode(dst))
+		return -EOPNOTSUPP;
+
+	if (src == dst) {
+		if (pos_in == pos_out)
+			return 0;
+		if (pos_out > pos_in && pos_out < pos_in + len)
+			return -EINVAL;
+	}
+
+	inode_lock(src);
+	down_write(&F2FS_I(src)->dio_rwsem[WRITE]);
+	if (src != dst) {
+		ret = -EBUSY;
+		if (!inode_trylock(dst))
+			goto out;
+		if (!down_write_trylock(&F2FS_I(dst)->dio_rwsem[WRITE])) {
+			inode_unlock(dst);
+			goto out;
+		}
+	}
+
+	ret = -EINVAL;
+	if (pos_in + len > src->i_size || pos_in + len < pos_in)
+		goto out_unlock;
+	if (len == 0)
+		olen = len = src->i_size - pos_in;
+	if (pos_in + len == src->i_size)
+		len = ALIGN(src->i_size, F2FS_BLKSIZE) - pos_in;
+	if (len == 0) {
+		ret = 0;
+		goto out_unlock;
+	}
+
+	dst_osize = dst->i_size;
+	if (pos_out + olen > dst->i_size)
+		dst_max_i_size = pos_out + olen;
+
+	/* verify the end result is block aligned */
+	if (!IS_ALIGNED(pos_in, F2FS_BLKSIZE) ||
+			!IS_ALIGNED(pos_in + len, F2FS_BLKSIZE) ||
+			!IS_ALIGNED(pos_out, F2FS_BLKSIZE))
+		goto out_unlock;
+
+	ret = f2fs_convert_inline_inode(src);
+	if (ret)
+		goto out_unlock;
+
+	ret = f2fs_convert_inline_inode(dst);
+	if (ret)
+		goto out_unlock;
+
+	/* write out all dirty pages from offset */
+	ret = filemap_write_and_wait_range(src->i_mapping,
+					pos_in, pos_in + len);
+	if (ret)
+		goto out_unlock;
+
+	ret = filemap_write_and_wait_range(dst->i_mapping,
+					pos_out, pos_out + len);
+	if (ret)
+		goto out_unlock;
+
+	f2fs_balance_fs(sbi, true);
+	f2fs_lock_op(sbi);
+	ret = __exchange_data_block(src, dst, pos_in >> F2FS_BLKSIZE_BITS,
+				pos_out >> F2FS_BLKSIZE_BITS,
+				len >> F2FS_BLKSIZE_BITS, false);
+
+	if (!ret) {
+		if (dst_max_i_size)
+			f2fs_i_size_write(dst, dst_max_i_size);
+		else if (dst_osize != dst->i_size)
+			f2fs_i_size_write(dst, dst_osize);
+	}
+	f2fs_unlock_op(sbi);
+out_unlock:
+	if (src != dst) {
+		up_write(&F2FS_I(dst)->dio_rwsem[WRITE]);
+		inode_unlock(dst);
+	}
+out:
+	up_write(&F2FS_I(src)->dio_rwsem[WRITE]);
+	inode_unlock(src);
+	return ret;
+}
+
+static int f2fs_ioc_move_range(struct file *filp, unsigned long arg)
+{
+	struct f2fs_move_range range;
+	struct fd dst;
+	int err;
+
+	if (!(filp->f_mode & FMODE_READ) ||
+			!(filp->f_mode & FMODE_WRITE))
+		return -EBADF;
+
+	if (copy_from_user(&range, (struct f2fs_move_range __user *)arg,
+							sizeof(range)))
+		return -EFAULT;
+
+	dst = fdget(range.dst_fd);
+	if (!dst.file)
+		return -EBADF;
+
+	if (!(dst.file->f_mode & FMODE_WRITE)) {
+		err = -EBADF;
+		goto err_out;
+	}
+
+	err = mnt_want_write_file(filp);
+	if (err)
+		goto err_out;
+
+	err = f2fs_move_file_range(filp, range.pos_in, dst.file,
+					range.pos_out, range.len);
+
+	mnt_drop_write_file(filp);
+	if (err)
+		goto err_out;
+
+	if (copy_to_user((struct f2fs_move_range __user *)arg,
+						&range, sizeof(range)))
+		err = -EFAULT;
+err_out:
+	fdput(dst);
+	return err;
+}
+
+static int f2fs_ioc_flush_device(struct file *filp, unsigned long arg)
+{
+	struct inode *inode = file_inode(filp);
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct sit_info *sm = SIT_I(sbi);
+	unsigned int start_segno = 0, end_segno = 0;
+	unsigned int dev_start_segno = 0, dev_end_segno = 0;
+	struct f2fs_flush_device range;
+	int ret;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
+	if (f2fs_readonly(sbi->sb))
+		return -EROFS;
+
+	if (copy_from_user(&range, (struct f2fs_flush_device __user *)arg,
+							sizeof(range)))
+		return -EFAULT;
+
+	if (!f2fs_is_multi_device(sbi) || sbi->s_ndevs - 1 <= range.dev_num ||
+			sbi->segs_per_sec != 1) {
+		f2fs_msg(sbi->sb, KERN_WARNING,
+			"Can't flush %u in %d for segs_per_sec %u != 1\n",
+				range.dev_num, sbi->s_ndevs,
+				sbi->segs_per_sec);
+		return -EINVAL;
+	}
+
+	ret = mnt_want_write_file(filp);
+	if (ret)
+		return ret;
+
+	if (range.dev_num != 0)
+		dev_start_segno = GET_SEGNO(sbi, FDEV(range.dev_num).start_blk);
+	dev_end_segno = GET_SEGNO(sbi, FDEV(range.dev_num).end_blk);
+
+	start_segno = sm->last_victim[FLUSH_DEVICE];
+	if (start_segno < dev_start_segno || start_segno >= dev_end_segno)
+		start_segno = dev_start_segno;
+	end_segno = min(start_segno + range.segments, dev_end_segno);
+
+	while (start_segno < end_segno) {
+		if (!mutex_trylock(&sbi->gc_mutex)) {
+			ret = -EBUSY;
+			goto out;
+		}
+		sm->last_victim[GC_CB] = end_segno + 1;
+		sm->last_victim[GC_GREEDY] = end_segno + 1;
+		sm->last_victim[ALLOC_NEXT] = end_segno + 1;
+		ret = f2fs_gc(sbi, true, true, start_segno);
+		if (ret == -EAGAIN)
+			ret = 0;
+		else if (ret < 0)
+			break;
+		start_segno++;
+	}
+out:
+	mnt_drop_write_file(filp);
+	return ret;
+}
+
+static int f2fs_ioc_get_features(struct file *filp, unsigned long arg)
+{
+	struct inode *inode = file_inode(filp);
+	u32 sb_feature = le32_to_cpu(F2FS_I_SB(inode)->raw_super->feature);
+
+	/* Must validate to set it with SQLite behavior in Android. */
+	sb_feature |= F2FS_FEATURE_ATOMIC_WRITE;
+
+	return put_user(sb_feature, (u32 __user *)arg);
+}
+
+#ifdef CONFIG_QUOTA
+static int f2fs_ioc_setproject(struct file *filp, __u32 projid)
+{
+	struct inode *inode = file_inode(filp);
+	struct f2fs_inode_info *fi = F2FS_I(inode);
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct super_block *sb = sbi->sb;
+	struct dquot *transfer_to[MAXQUOTAS] = {};
+	struct page *ipage;
+	kprojid_t kprojid;
+	int err;
+
+	if (!f2fs_sb_has_project_quota(sb)) {
+		if (projid != F2FS_DEF_PROJID)
+			return -EOPNOTSUPP;
+		else
+			return 0;
+	}
+
+	if (!f2fs_has_extra_attr(inode))
+		return -EOPNOTSUPP;
+
+	kprojid = make_kprojid(&init_user_ns, (projid_t)projid);
+
+	if (projid_eq(kprojid, F2FS_I(inode)->i_projid))
+		return 0;
+
+	err = mnt_want_write_file(filp);
+	if (err)
+		return err;
+
+	err = -EPERM;
+	inode_lock(inode);
+
+	/* Is it quota file? Do not allow user to mess with it */
+	if (IS_NOQUOTA(inode))
+		goto out_unlock;
+
+	ipage = get_node_page(sbi, inode->i_ino);
+	if (IS_ERR(ipage)) {
+		err = PTR_ERR(ipage);
+		goto out_unlock;
+	}
+
+	if (!F2FS_FITS_IN_INODE(F2FS_INODE(ipage), fi->i_extra_isize,
+								i_projid)) {
+		err = -EOVERFLOW;
+		f2fs_put_page(ipage, 1);
+		goto out_unlock;
+	}
+	f2fs_put_page(ipage, 1);
+
+	err = dquot_initialize(inode);
+	if (err)
+		goto out_unlock;
+
+	transfer_to[PRJQUOTA] = dqget(sb, make_kqid_projid(kprojid));
+	if (!IS_ERR(transfer_to[PRJQUOTA])) {
+		err = __dquot_transfer(inode, transfer_to);
+		dqput(transfer_to[PRJQUOTA]);
+		if (err)
+			goto out_dirty;
+	}
+
+	F2FS_I(inode)->i_projid = kprojid;
+	inode->i_ctime = current_time(inode);
+out_dirty:
+	f2fs_mark_inode_dirty_sync(inode, true);
+out_unlock:
+	inode_unlock(inode);
+	mnt_drop_write_file(filp);
+	return err;
+}
+#else
+static int f2fs_ioc_setproject(struct file *filp, __u32 projid)
+{
+	if (projid != F2FS_DEF_PROJID)
+		return -EOPNOTSUPP;
+	return 0;
+}
+#endif
+
+/* Transfer internal flags to xflags */
+static inline __u32 f2fs_iflags_to_xflags(unsigned long iflags)
+{
+	__u32 xflags = 0;
+
+	if (iflags & FS_SYNC_FL)
+		xflags |= FS_XFLAG_SYNC;
+	if (iflags & FS_IMMUTABLE_FL)
+		xflags |= FS_XFLAG_IMMUTABLE;
+	if (iflags & FS_APPEND_FL)
+		xflags |= FS_XFLAG_APPEND;
+	if (iflags & FS_NODUMP_FL)
+		xflags |= FS_XFLAG_NODUMP;
+	if (iflags & FS_NOATIME_FL)
+		xflags |= FS_XFLAG_NOATIME;
+	if (iflags & FS_PROJINHERIT_FL)
+		xflags |= FS_XFLAG_PROJINHERIT;
+	return xflags;
+}
+
+#define F2FS_SUPPORTED_FS_XFLAGS (FS_XFLAG_SYNC | FS_XFLAG_IMMUTABLE | \
+				  FS_XFLAG_APPEND | FS_XFLAG_NODUMP | \
+				  FS_XFLAG_NOATIME | FS_XFLAG_PROJINHERIT)
+
+/* Flags we can manipulate with through EXT4_IOC_FSSETXATTR */
+#define F2FS_FL_XFLAG_VISIBLE		(FS_SYNC_FL | \
+					 FS_IMMUTABLE_FL | \
+					 FS_APPEND_FL | \
+					 FS_NODUMP_FL | \
+					 FS_NOATIME_FL | \
+					 FS_PROJINHERIT_FL)
+
+/* Transfer xflags flags to internal */
+static inline unsigned long f2fs_xflags_to_iflags(__u32 xflags)
+{
+	unsigned long iflags = 0;
+
+	if (xflags & FS_XFLAG_SYNC)
+		iflags |= FS_SYNC_FL;
+	if (xflags & FS_XFLAG_IMMUTABLE)
+		iflags |= FS_IMMUTABLE_FL;
+	if (xflags & FS_XFLAG_APPEND)
+		iflags |= FS_APPEND_FL;
+	if (xflags & FS_XFLAG_NODUMP)
+		iflags |= FS_NODUMP_FL;
+	if (xflags & FS_XFLAG_NOATIME)
+		iflags |= FS_NOATIME_FL;
+	if (xflags & FS_XFLAG_PROJINHERIT)
+		iflags |= FS_PROJINHERIT_FL;
+
+	return iflags;
+}
+
+static int f2fs_ioc_fsgetxattr(struct file *filp, unsigned long arg)
+{
+	struct inode *inode = file_inode(filp);
+	struct f2fs_inode_info *fi = F2FS_I(inode);
+	struct fsxattr fa;
+
+	memset(&fa, 0, sizeof(struct fsxattr));
+	fa.fsx_xflags = f2fs_iflags_to_xflags(fi->i_flags &
+				(FS_FL_USER_VISIBLE | FS_PROJINHERIT_FL));
+
+	if (f2fs_sb_has_project_quota(inode->i_sb))
+		fa.fsx_projid = (__u32)from_kprojid(&init_user_ns,
+							fi->i_projid);
+
+	if (copy_to_user((struct fsxattr __user *)arg, &fa, sizeof(fa)))
+		return -EFAULT;
+	return 0;
+}
+
+static int f2fs_ioc_fssetxattr(struct file *filp, unsigned long arg)
+{
+	struct inode *inode = file_inode(filp);
+	struct f2fs_inode_info *fi = F2FS_I(inode);
+	struct fsxattr fa;
+	unsigned int flags;
+	int err;
+
+	if (copy_from_user(&fa, (struct fsxattr __user *)arg, sizeof(fa)))
+		return -EFAULT;
+
+	/* Make sure caller has proper permission */
+	if (!inode_owner_or_capable(inode))
+		return -EACCES;
+
+	if (fa.fsx_xflags & ~F2FS_SUPPORTED_FS_XFLAGS)
+		return -EOPNOTSUPP;
+
+	flags = f2fs_xflags_to_iflags(fa.fsx_xflags);
+	if (f2fs_mask_flags(inode->i_mode, flags) != flags)
+		return -EOPNOTSUPP;
+
+	err = mnt_want_write_file(filp);
+	if (err)
+		return err;
+
+	inode_lock(inode);
+	flags = (fi->i_flags & ~F2FS_FL_XFLAG_VISIBLE) |
+				(flags & F2FS_FL_XFLAG_VISIBLE);
+	err = __f2fs_ioc_setflags(inode, flags);
+	inode_unlock(inode);
+	mnt_drop_write_file(filp);
+	if (err)
+		return err;
+
+	err = f2fs_ioc_setproject(filp, fa.fsx_projid);
+	if (err)
+		return err;
+
+	return 0;
+}
+
+int f2fs_pin_file_control(struct inode *inode, bool inc)
+{
+	struct f2fs_inode_info *fi = F2FS_I(inode);
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+
+	/* Use i_gc_failures for normal file as a risk signal. */
+	if (inc)
+		f2fs_i_gc_failures_write(inode, fi->i_gc_failures + 1);
+
+	if (fi->i_gc_failures > sbi->gc_pin_file_threshold) {
+		f2fs_msg(sbi->sb, KERN_WARNING,
+			"%s: Enable GC = ino %lx after %x GC trials\n",
+			__func__, inode->i_ino, fi->i_gc_failures);
+		clear_inode_flag(inode, FI_PIN_FILE);
+		return -EAGAIN;
+	}
+	return 0;
+}
+
+static int f2fs_ioc_set_pin_file(struct file *filp, unsigned long arg)
+{
+	struct inode *inode = file_inode(filp);
+	__u32 pin;
+	int ret = 0;
+
+	if (!inode_owner_or_capable(inode))
+		return -EACCES;
+
+	if (get_user(pin, (__u32 __user *)arg))
+		return -EFAULT;
+
+	if (!S_ISREG(inode->i_mode))
+		return -EINVAL;
+
+	if (f2fs_readonly(F2FS_I_SB(inode)->sb))
+		return -EROFS;
+
+	ret = mnt_want_write_file(filp);
+	if (ret)
+		return ret;
+
+	inode_lock(inode);
+
+	if (should_update_outplace(inode, NULL)) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	if (!pin) {
+		clear_inode_flag(inode, FI_PIN_FILE);
+		F2FS_I(inode)->i_gc_failures = 1;
+		goto done;
+	}
+
+	if (f2fs_pin_file_control(inode, false)) {
+		ret = -EAGAIN;
+		goto out;
+	}
+	ret = f2fs_convert_inline_inode(inode);
+	if (ret)
+		goto out;
+
+	set_inode_flag(inode, FI_PIN_FILE);
+	ret = F2FS_I(inode)->i_gc_failures;
+done:
+	f2fs_update_time(F2FS_I_SB(inode), REQ_TIME);
+out:
+	inode_unlock(inode);
+	mnt_drop_write_file(filp);
+	return ret;
+}
+
+static int f2fs_ioc_get_pin_file(struct file *filp, unsigned long arg)
+{
+	struct inode *inode = file_inode(filp);
+	__u32 pin = 0;
+
+	if (is_inode_flag_set(inode, FI_PIN_FILE))
+		pin = F2FS_I(inode)->i_gc_failures;
+	return put_user(pin, (u32 __user *)arg);
+}
+
+int f2fs_precache_extents(struct inode *inode)
+{
+	struct f2fs_inode_info *fi = F2FS_I(inode);
+	struct f2fs_map_blocks map;
+	pgoff_t m_next_extent;
+	loff_t end;
+	int err;
+
+	if (is_inode_flag_set(inode, FI_NO_EXTENT))
+		return -EOPNOTSUPP;
+
+	map.m_lblk = 0;
+	map.m_next_pgofs = NULL;
+	map.m_next_extent = &m_next_extent;
+	map.m_seg_type = NO_CHECK_TYPE;
+	end = F2FS_I_SB(inode)->max_file_blocks;
+
+	while (map.m_lblk < end) {
+		map.m_len = end - map.m_lblk;
+
+		down_write(&fi->dio_rwsem[WRITE]);
+		err = f2fs_map_blocks(inode, &map, 0, F2FS_GET_BLOCK_PRECACHE);
+		up_write(&fi->dio_rwsem[WRITE]);
+		if (err)
+			return err;
+
+		map.m_lblk = m_next_extent;
+	}
+
+	return err;
+}
+
+static int f2fs_ioc_precache_extents(struct file *filp, unsigned long arg)
+{
+	return f2fs_precache_extents(file_inode(filp));
+}
+
+long f2fs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
+{
+	if (unlikely(f2fs_cp_error(F2FS_I_SB(file_inode(filp)))))
+		return -EIO;
+
+	switch (cmd) {
+	case F2FS_IOC_GETFLAGS:
+		return f2fs_ioc_getflags(filp, arg);
+	case F2FS_IOC_SETFLAGS:
+		return f2fs_ioc_setflags(filp, arg);
+	case F2FS_IOC_GETVERSION:
+		return f2fs_ioc_getversion(filp, arg);
+	case F2FS_IOC_START_ATOMIC_WRITE:
+		return f2fs_ioc_start_atomic_write(filp);
+	case F2FS_IOC_COMMIT_ATOMIC_WRITE:
+		return f2fs_ioc_commit_atomic_write(filp);
+	case F2FS_IOC_START_VOLATILE_WRITE:
+		return f2fs_ioc_start_volatile_write(filp);
+	case F2FS_IOC_RELEASE_VOLATILE_WRITE:
+		return f2fs_ioc_release_volatile_write(filp);
+	case F2FS_IOC_ABORT_VOLATILE_WRITE:
+		return f2fs_ioc_abort_volatile_write(filp);
+	case F2FS_IOC_SHUTDOWN:
+		return f2fs_ioc_shutdown(filp, arg);
+	case FITRIM:
+		return f2fs_ioc_fitrim(filp, arg);
+	case F2FS_IOC_SET_ENCRYPTION_POLICY:
+		return f2fs_ioc_set_encryption_policy(filp, arg);
+	case F2FS_IOC_GET_ENCRYPTION_POLICY:
+		return f2fs_ioc_get_encryption_policy(filp, arg);
+	case F2FS_IOC_GET_ENCRYPTION_PWSALT:
+		return f2fs_ioc_get_encryption_pwsalt(filp, arg);
+	case F2FS_IOC_GARBAGE_COLLECT:
+		return f2fs_ioc_gc(filp, arg);
+	case F2FS_IOC_GARBAGE_COLLECT_RANGE:
+		return f2fs_ioc_gc_range(filp, arg);
+	case F2FS_IOC_WRITE_CHECKPOINT:
+		return f2fs_ioc_write_checkpoint(filp, arg);
+	case F2FS_IOC_DEFRAGMENT:
+		return f2fs_ioc_defragment(filp, arg);
+	case F2FS_IOC_MOVE_RANGE:
+		return f2fs_ioc_move_range(filp, arg);
+	case F2FS_IOC_FLUSH_DEVICE:
+		return f2fs_ioc_flush_device(filp, arg);
+	case F2FS_IOC_GET_FEATURES:
+		return f2fs_ioc_get_features(filp, arg);
+	case F2FS_IOC_FSGETXATTR:
+		return f2fs_ioc_fsgetxattr(filp, arg);
+	case F2FS_IOC_FSSETXATTR:
+		return f2fs_ioc_fssetxattr(filp, arg);
+	case F2FS_IOC_GET_PIN_FILE:
+		return f2fs_ioc_get_pin_file(filp, arg);
+	case F2FS_IOC_SET_PIN_FILE:
+		return f2fs_ioc_set_pin_file(filp, arg);
+	case F2FS_IOC_PRECACHE_EXTENTS:
+		return f2fs_ioc_precache_extents(filp, arg);
+	default:
+		return -ENOTTY;
+	}
+}
+
+static ssize_t f2fs_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
+{
+	struct file *file = iocb->ki_filp;
+	struct inode *inode = file_inode(file);
+	struct blk_plug plug;
+	ssize_t ret;
+
+	if (unlikely(f2fs_cp_error(F2FS_I_SB(inode))))
+		return -EIO;
+
+	if ((iocb->ki_flags & IOCB_NOWAIT) && !(iocb->ki_flags & IOCB_DIRECT))
+		return -EINVAL;
+
+	if (!inode_trylock(inode)) {
+		if (iocb->ki_flags & IOCB_NOWAIT)
+			return -EAGAIN;
+		inode_lock(inode);
+	}
+
+	ret = generic_write_checks(iocb, from);
+	if (ret > 0) {
+		bool preallocated = false;
+		size_t target_size = 0;
+		int err;
+
+		if (iov_iter_fault_in_readable(from, iov_iter_count(from)))
+			set_inode_flag(inode, FI_NO_PREALLOC);
+
+		if ((iocb->ki_flags & IOCB_NOWAIT) &&
+			(iocb->ki_flags & IOCB_DIRECT)) {
+				if (!f2fs_overwrite_io(inode, iocb->ki_pos,
+						iov_iter_count(from)) ||
+					f2fs_has_inline_data(inode) ||
+					f2fs_force_buffered_io(inode, WRITE)) {
+						inode_unlock(inode);
+						return -EAGAIN;
+				}
+
+		} else {
+			preallocated = true;
+			target_size = iocb->ki_pos + iov_iter_count(from);
+
+			err = f2fs_preallocate_blocks(iocb, from);
+			if (err) {
+				clear_inode_flag(inode, FI_NO_PREALLOC);
+				inode_unlock(inode);
+				return err;
+			}
+		}
+		blk_start_plug(&plug);
+		ret = __generic_file_write_iter(iocb, from);
+		blk_finish_plug(&plug);
+		clear_inode_flag(inode, FI_NO_PREALLOC);
+
+		/* if we couldn't write data, we should deallocate blocks. */
+		if (preallocated && i_size_read(inode) < target_size)
+			f2fs_truncate(inode);
+
+		if (ret > 0)
+			f2fs_update_iostat(F2FS_I_SB(inode), APP_WRITE_IO, ret);
+	}
+	inode_unlock(inode);
+
+	if (ret > 0)
+		ret = generic_write_sync(iocb, ret);
+	return ret;
+}
+
+#ifdef CONFIG_COMPAT
+long f2fs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+	switch (cmd) {
+	case F2FS_IOC32_GETFLAGS:
+		cmd = F2FS_IOC_GETFLAGS;
+		break;
+	case F2FS_IOC32_SETFLAGS:
+		cmd = F2FS_IOC_SETFLAGS;
+		break;
+	case F2FS_IOC32_GETVERSION:
+		cmd = F2FS_IOC_GETVERSION;
+		break;
+	case F2FS_IOC_START_ATOMIC_WRITE:
+	case F2FS_IOC_COMMIT_ATOMIC_WRITE:
+	case F2FS_IOC_START_VOLATILE_WRITE:
+	case F2FS_IOC_RELEASE_VOLATILE_WRITE:
+	case F2FS_IOC_ABORT_VOLATILE_WRITE:
+	case F2FS_IOC_SHUTDOWN:
+	case F2FS_IOC_SET_ENCRYPTION_POLICY:
+	case F2FS_IOC_GET_ENCRYPTION_PWSALT:
+	case F2FS_IOC_GET_ENCRYPTION_POLICY:
+	case F2FS_IOC_GARBAGE_COLLECT:
+	case F2FS_IOC_GARBAGE_COLLECT_RANGE:
+	case F2FS_IOC_WRITE_CHECKPOINT:
+	case F2FS_IOC_DEFRAGMENT:
+	case F2FS_IOC_MOVE_RANGE:
+	case F2FS_IOC_FLUSH_DEVICE:
+	case F2FS_IOC_GET_FEATURES:
+	case F2FS_IOC_FSGETXATTR:
+	case F2FS_IOC_FSSETXATTR:
+	case F2FS_IOC_GET_PIN_FILE:
+	case F2FS_IOC_SET_PIN_FILE:
+	case F2FS_IOC_PRECACHE_EXTENTS:
+		break;
+	default:
+		return -ENOIOCTLCMD;
+	}
+	return f2fs_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
+}
+#endif
+
+const struct file_operations f2fs_file_operations = {
+	.llseek		= f2fs_llseek,
+	.read_iter	= generic_file_read_iter,
+	.write_iter	= f2fs_file_write_iter,
+	.open		= f2fs_file_open,
+	.release	= f2fs_release_file,
+	.mmap		= f2fs_file_mmap,
+	.flush		= f2fs_file_flush,
+	.fsync		= f2fs_sync_file,
+	.fallocate	= f2fs_fallocate,
+	.unlocked_ioctl	= f2fs_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl	= f2fs_compat_ioctl,
+#endif
+	.splice_read	= generic_file_splice_read,
+	.splice_write	= iter_file_splice_write,
+};
diff --git a/src/kernel/linux/v4.14/fs/f2fs/gc.c b/src/kernel/linux/v4.14/fs/f2fs/gc.c
new file mode 100644
index 0000000..558ba62
--- /dev/null
+++ b/src/kernel/linux/v4.14/fs/f2fs/gc.c
@@ -0,0 +1,1136 @@
+/*
+ * fs/f2fs/gc.c
+ *
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ *             http://www.samsung.com/
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/fs.h>
+#include <linux/module.h>
+#include <linux/backing-dev.h>
+#include <linux/init.h>
+#include <linux/f2fs_fs.h>
+#include <linux/kthread.h>
+#include <linux/delay.h>
+#include <linux/freezer.h>
+
+#include "f2fs.h"
+#include "node.h"
+#include "segment.h"
+#include "gc.h"
+#include <trace/events/f2fs.h>
+
+static int gc_thread_func(void *data)
+{
+	struct f2fs_sb_info *sbi = data;
+	struct f2fs_gc_kthread *gc_th = sbi->gc_thread;
+	wait_queue_head_t *wq = &sbi->gc_thread->gc_wait_queue_head;
+	unsigned int wait_ms;
+
+	wait_ms = gc_th->min_sleep_time;
+
+	set_freezable();
+	do {
+		wait_event_interruptible_timeout(*wq,
+				kthread_should_stop() || freezing(current) ||
+				gc_th->gc_wake,
+				msecs_to_jiffies(wait_ms));
+
+		/* give it a try one time */
+		if (gc_th->gc_wake)
+			gc_th->gc_wake = 0;
+
+		if (try_to_freeze())
+			continue;
+		if (kthread_should_stop())
+			break;
+
+		if (sbi->sb->s_writers.frozen >= SB_FREEZE_WRITE) {
+			increase_sleep_time(gc_th, &wait_ms);
+			continue;
+		}
+
+#ifdef CONFIG_F2FS_FAULT_INJECTION
+		if (time_to_inject(sbi, FAULT_CHECKPOINT)) {
+			f2fs_show_injection_info(FAULT_CHECKPOINT);
+			f2fs_stop_checkpoint(sbi, false);
+		}
+#endif
+
+		if (!sb_start_write_trylock(sbi->sb))
+			continue;
+
+		/*
+		 * [GC triggering condition]
+		 * 0. GC is not conducted currently.
+		 * 1. There are enough dirty segments.
+		 * 2. IO subsystem is idle by checking the # of writeback pages.
+		 * 3. IO subsystem is idle by checking the # of requests in
+		 *    bdev's request list.
+		 *
+		 * Note) We have to avoid triggering GCs frequently.
+		 * Because it is possible that some segments can be
+		 * invalidated soon after by user update or deletion.
+		 * So, I'd like to wait some time to collect dirty segments.
+		 */
+		if (gc_th->gc_urgent) {
+			wait_ms = gc_th->urgent_sleep_time;
+			mutex_lock(&sbi->gc_mutex);
+			goto do_gc;
+		}
+
+		if (!mutex_trylock(&sbi->gc_mutex))
+			goto next;
+
+		if (!is_idle(sbi)) {
+			increase_sleep_time(gc_th, &wait_ms);
+			mutex_unlock(&sbi->gc_mutex);
+			goto next;
+		}
+
+		if (has_enough_invalid_blocks(sbi))
+			decrease_sleep_time(gc_th, &wait_ms);
+		else
+			increase_sleep_time(gc_th, &wait_ms);
+do_gc:
+		stat_inc_bggc_count(sbi);
+
+		/* if return value is not zero, no victim was selected */
+		if (f2fs_gc(sbi, test_opt(sbi, FORCE_FG_GC), true, NULL_SEGNO))
+			wait_ms = gc_th->no_gc_sleep_time;
+
+		trace_f2fs_background_gc(sbi->sb, wait_ms,
+				prefree_segments(sbi), free_segments(sbi));
+
+		/* balancing f2fs's metadata periodically */
+		f2fs_balance_fs_bg(sbi);
+next:
+		sb_end_write(sbi->sb);
+
+	} while (!kthread_should_stop());
+	return 0;
+}
+
+int start_gc_thread(struct f2fs_sb_info *sbi)
+{
+	struct f2fs_gc_kthread *gc_th;
+	dev_t dev = sbi->sb->s_bdev->bd_dev;
+	int err = 0;
+
+	gc_th = f2fs_kmalloc(sbi, sizeof(struct f2fs_gc_kthread), GFP_KERNEL);
+	if (!gc_th) {
+		err = -ENOMEM;
+		goto out;
+	}
+
+	gc_th->urgent_sleep_time = DEF_GC_THREAD_URGENT_SLEEP_TIME;
+	gc_th->min_sleep_time = DEF_GC_THREAD_MIN_SLEEP_TIME;
+	gc_th->max_sleep_time = DEF_GC_THREAD_MAX_SLEEP_TIME;
+	gc_th->no_gc_sleep_time = DEF_GC_THREAD_NOGC_SLEEP_TIME;
+
+	gc_th->gc_idle = 0;
+	gc_th->gc_urgent = 0;
+	gc_th->gc_wake= 0;
+
+	sbi->gc_thread = gc_th;
+	init_waitqueue_head(&sbi->gc_thread->gc_wait_queue_head);
+	sbi->gc_thread->f2fs_gc_task = kthread_run(gc_thread_func, sbi,
+			"f2fs_gc-%u:%u", MAJOR(dev), MINOR(dev));
+	if (IS_ERR(gc_th->f2fs_gc_task)) {
+		err = PTR_ERR(gc_th->f2fs_gc_task);
+		kfree(gc_th);
+		sbi->gc_thread = NULL;
+	}
+out:
+	return err;
+}
+
+void stop_gc_thread(struct f2fs_sb_info *sbi)
+{
+	struct f2fs_gc_kthread *gc_th = sbi->gc_thread;
+	if (!gc_th)
+		return;
+	kthread_stop(gc_th->f2fs_gc_task);
+	kfree(gc_th);
+	sbi->gc_thread = NULL;
+}
+
+static int select_gc_type(struct f2fs_gc_kthread *gc_th, int gc_type)
+{
+	int gc_mode = (gc_type == BG_GC) ? GC_CB : GC_GREEDY;
+
+	if (!gc_th)
+		return gc_mode;
+
+	if (gc_th->gc_idle) {
+		if (gc_th->gc_idle == 1)
+			gc_mode = GC_CB;
+		else if (gc_th->gc_idle == 2)
+			gc_mode = GC_GREEDY;
+	}
+	if (gc_th->gc_urgent)
+		gc_mode = GC_GREEDY;
+	return gc_mode;
+}
+
+static void select_policy(struct f2fs_sb_info *sbi, int gc_type,
+			int type, struct victim_sel_policy *p)
+{
+	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
+
+	if (p->alloc_mode == SSR) {
+		p->gc_mode = GC_GREEDY;
+		p->dirty_segmap = dirty_i->dirty_segmap[type];
+		p->max_search = dirty_i->nr_dirty[type];
+		p->ofs_unit = 1;
+	} else {
+		p->gc_mode = select_gc_type(sbi->gc_thread, gc_type);
+		p->dirty_segmap = dirty_i->dirty_segmap[DIRTY];
+		p->max_search = dirty_i->nr_dirty[DIRTY];
+		p->ofs_unit = sbi->segs_per_sec;
+	}
+
+	/* we need to check every dirty segments in the FG_GC case */
+	if (gc_type != FG_GC &&
+			(sbi->gc_thread && !sbi->gc_thread->gc_urgent) &&
+			p->max_search > sbi->max_victim_search)
+		p->max_search = sbi->max_victim_search;
+
+	/* let's select beginning hot/small space first in no_heap mode*/
+	if (test_opt(sbi, NOHEAP) &&
+		(type == CURSEG_HOT_DATA || IS_NODESEG(type)))
+		p->offset = 0;
+	else
+		p->offset = SIT_I(sbi)->last_victim[p->gc_mode];
+}
+
+static unsigned int get_max_cost(struct f2fs_sb_info *sbi,
+				struct victim_sel_policy *p)
+{
+	/* SSR allocates in a segment unit */
+	if (p->alloc_mode == SSR)
+		return sbi->blocks_per_seg;
+	if (p->gc_mode == GC_GREEDY)
+		return 2 * sbi->blocks_per_seg * p->ofs_unit;
+	else if (p->gc_mode == GC_CB)
+		return UINT_MAX;
+	else /* No other gc_mode */
+		return 0;
+}
+
+static unsigned int check_bg_victims(struct f2fs_sb_info *sbi)
+{
+	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
+	unsigned int secno;
+
+	/*
+	 * If the gc_type is FG_GC, we can select victim segments
+	 * selected by background GC before.
+	 * Those segments guarantee they have small valid blocks.
+	 */
+	for_each_set_bit(secno, dirty_i->victim_secmap, MAIN_SECS(sbi)) {
+		if (sec_usage_check(sbi, secno))
+			continue;
+
+		if (no_fggc_candidate(sbi, secno))
+			continue;
+
+		clear_bit(secno, dirty_i->victim_secmap);
+		return GET_SEG_FROM_SEC(sbi, secno);
+	}
+	return NULL_SEGNO;
+}
+
+static unsigned int get_cb_cost(struct f2fs_sb_info *sbi, unsigned int segno)
+{
+	struct sit_info *sit_i = SIT_I(sbi);
+	unsigned int secno = GET_SEC_FROM_SEG(sbi, segno);
+	unsigned int start = GET_SEG_FROM_SEC(sbi, secno);
+	unsigned long long mtime = 0;
+	unsigned int vblocks;
+	unsigned char age = 0;
+	unsigned char u;
+	unsigned int i;
+
+	for (i = 0; i < sbi->segs_per_sec; i++)
+		mtime += get_seg_entry(sbi, start + i)->mtime;
+	vblocks = get_valid_blocks(sbi, segno, true);
+
+	mtime = div_u64(mtime, sbi->segs_per_sec);
+	vblocks = div_u64(vblocks, sbi->segs_per_sec);
+
+	u = (vblocks * 100) >> sbi->log_blocks_per_seg;
+
+	/* Handle if the system time has changed by the user */
+	if (mtime < sit_i->min_mtime)
+		sit_i->min_mtime = mtime;
+	if (mtime > sit_i->max_mtime)
+		sit_i->max_mtime = mtime;
+	if (sit_i->max_mtime != sit_i->min_mtime)
+		age = 100 - div64_u64(100 * (mtime - sit_i->min_mtime),
+				sit_i->max_mtime - sit_i->min_mtime);
+
+	return UINT_MAX - ((100 * (100 - u) * age) / (100 + u));
+}
+
+static inline unsigned int get_gc_cost(struct f2fs_sb_info *sbi,
+			unsigned int segno, struct victim_sel_policy *p)
+{
+	if (p->alloc_mode == SSR)
+		return get_seg_entry(sbi, segno)->ckpt_valid_blocks;
+
+	/* alloc_mode == LFS */
+	if (p->gc_mode == GC_GREEDY)
+		return get_valid_blocks(sbi, segno, true);
+	else
+		return get_cb_cost(sbi, segno);
+}
+
+static unsigned int count_bits(const unsigned long *addr,
+				unsigned int offset, unsigned int len)
+{
+	unsigned int end = offset + len, sum = 0;
+
+	while (offset < end) {
+		if (test_bit(offset++, addr))
+			++sum;
+	}
+	return sum;
+}
+
+/*
+ * This function is called from two paths.
+ * One is garbage collection and the other is SSR segment selection.
+ * When it is called during GC, it just gets a victim segment
+ * and it does not remove it from dirty seglist.
+ * When it is called from SSR segment selection, it finds a segment
+ * which has minimum valid blocks and removes it from dirty seglist.
+ */
+static int get_victim_by_default(struct f2fs_sb_info *sbi,
+		unsigned int *result, int gc_type, int type, char alloc_mode)
+{
+	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
+	struct sit_info *sm = SIT_I(sbi);
+	struct victim_sel_policy p;
+	unsigned int secno, last_victim;
+	unsigned int last_segment = MAIN_SEGS(sbi);
+	unsigned int nsearched = 0;
+
+	mutex_lock(&dirty_i->seglist_lock);
+
+	p.alloc_mode = alloc_mode;
+	select_policy(sbi, gc_type, type, &p);
+
+	p.min_segno = NULL_SEGNO;
+	p.min_cost = get_max_cost(sbi, &p);
+
+	if (*result != NULL_SEGNO) {
+		if (get_valid_blocks(sbi, *result, false) &&
+			!sec_usage_check(sbi, GET_SEC_FROM_SEG(sbi, *result)))
+			p.min_segno = *result;
+		goto out;
+	}
+
+	if (p.max_search == 0)
+		goto out;
+
+	last_victim = sm->last_victim[p.gc_mode];
+	if (p.alloc_mode == LFS && gc_type == FG_GC) {
+		p.min_segno = check_bg_victims(sbi);
+		if (p.min_segno != NULL_SEGNO)
+			goto got_it;
+	}
+
+	while (1) {
+		unsigned long cost;
+		unsigned int segno;
+
+		segno = find_next_bit(p.dirty_segmap, last_segment, p.offset);
+		if (segno >= last_segment) {
+			if (sm->last_victim[p.gc_mode]) {
+				last_segment =
+					sm->last_victim[p.gc_mode];
+				sm->last_victim[p.gc_mode] = 0;
+				p.offset = 0;
+				continue;
+			}
+			break;
+		}
+
+		p.offset = segno + p.ofs_unit;
+		if (p.ofs_unit > 1) {
+			p.offset -= segno % p.ofs_unit;
+			nsearched += count_bits(p.dirty_segmap,
+						p.offset - p.ofs_unit,
+						p.ofs_unit);
+		} else {
+			nsearched++;
+		}
+
+		secno = GET_SEC_FROM_SEG(sbi, segno);
+
+		if (sec_usage_check(sbi, secno))
+			goto next;
+		if (gc_type == BG_GC && test_bit(secno, dirty_i->victim_secmap))
+			goto next;
+		if (gc_type == FG_GC && p.alloc_mode == LFS &&
+					no_fggc_candidate(sbi, secno))
+			goto next;
+
+		cost = get_gc_cost(sbi, segno, &p);
+
+		if (p.min_cost > cost) {
+			p.min_segno = segno;
+			p.min_cost = cost;
+		}
+next:
+		if (nsearched >= p.max_search) {
+			if (!sm->last_victim[p.gc_mode] && segno <= last_victim)
+				sm->last_victim[p.gc_mode] = last_victim + 1;
+			else
+				sm->last_victim[p.gc_mode] = segno + 1;
+			sm->last_victim[p.gc_mode] %= MAIN_SEGS(sbi);
+			break;
+		}
+	}
+	if (p.min_segno != NULL_SEGNO) {
+got_it:
+		if (p.alloc_mode == LFS) {
+			secno = GET_SEC_FROM_SEG(sbi, p.min_segno);
+			if (gc_type == FG_GC)
+				sbi->cur_victim_sec = secno;
+			else
+				set_bit(secno, dirty_i->victim_secmap);
+		}
+		*result = (p.min_segno / p.ofs_unit) * p.ofs_unit;
+
+		trace_f2fs_get_victim(sbi->sb, type, gc_type, &p,
+				sbi->cur_victim_sec,
+				prefree_segments(sbi), free_segments(sbi));
+	}
+out:
+	mutex_unlock(&dirty_i->seglist_lock);
+
+	return (p.min_segno == NULL_SEGNO) ? 0 : 1;
+}
+
+static const struct victim_selection default_v_ops = {
+	.get_victim = get_victim_by_default,
+};
+
+static struct inode *find_gc_inode(struct gc_inode_list *gc_list, nid_t ino)
+{
+	struct inode_entry *ie;
+
+	ie = radix_tree_lookup(&gc_list->iroot, ino);
+	if (ie)
+		return ie->inode;
+	return NULL;
+}
+
+static void add_gc_inode(struct gc_inode_list *gc_list, struct inode *inode)
+{
+	struct inode_entry *new_ie;
+
+	if (inode == find_gc_inode(gc_list, inode->i_ino)) {
+		iput(inode);
+		return;
+	}
+	new_ie = f2fs_kmem_cache_alloc(inode_entry_slab, GFP_NOFS);
+	new_ie->inode = inode;
+
+	f2fs_radix_tree_insert(&gc_list->iroot, inode->i_ino, new_ie);
+	list_add_tail(&new_ie->list, &gc_list->ilist);
+}
+
+static void put_gc_inode(struct gc_inode_list *gc_list)
+{
+	struct inode_entry *ie, *next_ie;
+	list_for_each_entry_safe(ie, next_ie, &gc_list->ilist, list) {
+		radix_tree_delete(&gc_list->iroot, ie->inode->i_ino);
+		iput(ie->inode);
+		list_del(&ie->list);
+		kmem_cache_free(inode_entry_slab, ie);
+	}
+}
+
+static int check_valid_map(struct f2fs_sb_info *sbi,
+				unsigned int segno, int offset)
+{
+	struct sit_info *sit_i = SIT_I(sbi);
+	struct seg_entry *sentry;
+	int ret;
+
+	down_read(&sit_i->sentry_lock);
+	sentry = get_seg_entry(sbi, segno);
+	ret = f2fs_test_bit(offset, sentry->cur_valid_map);
+	up_read(&sit_i->sentry_lock);
+	return ret;
+}
+
+/*
+ * This function compares node address got in summary with that in NAT.
+ * On validity, copy that node with cold status, otherwise (invalid node)
+ * ignore that.
+ */
+static void gc_node_segment(struct f2fs_sb_info *sbi,
+		struct f2fs_summary *sum, unsigned int segno, int gc_type)
+{
+	struct f2fs_summary *entry;
+	block_t start_addr;
+	int off;
+	int phase = 0;
+
+	start_addr = START_BLOCK(sbi, segno);
+
+next_step:
+	entry = sum;
+
+	for (off = 0; off < sbi->blocks_per_seg; off++, entry++) {
+		nid_t nid = le32_to_cpu(entry->nid);
+		struct page *node_page;
+		struct node_info ni;
+
+		/* stop BG_GC if there is not enough free sections. */
+		if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0))
+			return;
+
+		if (check_valid_map(sbi, segno, off) == 0)
+			continue;
+
+		if (phase == 0) {
+			ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nid), 1,
+							META_NAT, true);
+			continue;
+		}
+
+		if (phase == 1) {
+			ra_node_page(sbi, nid);
+			continue;
+		}
+
+		/* phase == 2 */
+		node_page = get_node_page(sbi, nid);
+		if (IS_ERR(node_page))
+			continue;
+
+		/* block may become invalid during get_node_page */
+		if (check_valid_map(sbi, segno, off) == 0) {
+			f2fs_put_page(node_page, 1);
+			continue;
+		}
+
+		get_node_info(sbi, nid, &ni);
+		if (ni.blk_addr != start_addr + off) {
+			f2fs_put_page(node_page, 1);
+			continue;
+		}
+
+		move_node_page(node_page, gc_type);
+		stat_inc_node_blk_count(sbi, 1, gc_type);
+	}
+
+	if (++phase < 3)
+		goto next_step;
+}
+
+/*
+ * Calculate start block index indicating the given node offset.
+ * Be careful, caller should give this node offset only indicating direct node
+ * blocks. If any node offsets, which point the other types of node blocks such
+ * as indirect or double indirect node blocks, are given, it must be a caller's
+ * bug.
+ */
+block_t start_bidx_of_node(unsigned int node_ofs, struct inode *inode)
+{
+	unsigned int indirect_blks = 2 * NIDS_PER_BLOCK + 4;
+	unsigned int bidx;
+
+	if (node_ofs == 0)
+		return 0;
+
+	if (node_ofs <= 2) {
+		bidx = node_ofs - 1;
+	} else if (node_ofs <= indirect_blks) {
+		int dec = (node_ofs - 4) / (NIDS_PER_BLOCK + 1);
+		bidx = node_ofs - 2 - dec;
+	} else {
+		int dec = (node_ofs - indirect_blks - 3) / (NIDS_PER_BLOCK + 1);
+		bidx = node_ofs - 5 - dec;
+	}
+	return bidx * ADDRS_PER_BLOCK + ADDRS_PER_INODE(inode);
+}
+
+static bool is_alive(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
+		struct node_info *dni, block_t blkaddr, unsigned int *nofs)
+{
+	struct page *node_page;
+	nid_t nid;
+	unsigned int ofs_in_node;
+	block_t source_blkaddr;
+
+	nid = le32_to_cpu(sum->nid);
+	ofs_in_node = le16_to_cpu(sum->ofs_in_node);
+
+	node_page = get_node_page(sbi, nid);
+	if (IS_ERR(node_page))
+		return false;
+
+	get_node_info(sbi, nid, dni);
+
+	if (sum->version != dni->version) {
+		f2fs_msg(sbi->sb, KERN_WARNING,
+				"%s: valid data with mismatched node version.",
+				__func__);
+		set_sbi_flag(sbi, SBI_NEED_FSCK);
+	}
+
+	*nofs = ofs_of_node(node_page);
+	source_blkaddr = datablock_addr(NULL, node_page, ofs_in_node);
+	f2fs_put_page(node_page, 1);
+
+	if (source_blkaddr != blkaddr)
+		return false;
+	return true;
+}
+
+/*
+ * Move data block via META_MAPPING while keeping locked data page.
+ * This can be used to move blocks, aka LBAs, directly on disk.
+ */
+static void move_data_block(struct inode *inode, block_t bidx,
+					unsigned int segno, int off)
+{
+	struct f2fs_io_info fio = {
+		.sbi = F2FS_I_SB(inode),
+		.ino = inode->i_ino,
+		.type = DATA,
+		.temp = COLD,
+		.op = REQ_OP_READ,
+		.op_flags = 0,
+		.encrypted_page = NULL,
+		.in_list = false,
+	};
+	struct dnode_of_data dn;
+	struct f2fs_summary sum;
+	struct node_info ni;
+	struct page *page;
+	block_t newaddr;
+	int err;
+
+	/* do not read out */
+	page = f2fs_grab_cache_page(inode->i_mapping, bidx, false);
+	if (!page)
+		return;
+
+	if (!check_valid_map(F2FS_I_SB(inode), segno, off))
+		goto out;
+
+	if (f2fs_is_atomic_file(inode))
+		goto out;
+
+	if (f2fs_is_pinned_file(inode)) {
+		f2fs_pin_file_control(inode, true);
+		goto out;
+	}
+
+	set_new_dnode(&dn, inode, NULL, NULL, 0);
+	err = get_dnode_of_data(&dn, bidx, LOOKUP_NODE);
+	if (err)
+		goto out;
+
+	if (unlikely(dn.data_blkaddr == NULL_ADDR)) {
+		ClearPageUptodate(page);
+		goto put_out;
+	}
+
+	/*
+	 * don't cache encrypted data into meta inode until previous dirty
+	 * data were writebacked to avoid racing between GC and flush.
+	 */
+	f2fs_wait_on_page_writeback(page, DATA, true);
+
+	get_node_info(fio.sbi, dn.nid, &ni);
+	set_summary(&sum, dn.nid, dn.ofs_in_node, ni.version);
+
+	/* read page */
+	fio.page = page;
+	fio.new_blkaddr = fio.old_blkaddr = dn.data_blkaddr;
+
+	allocate_data_block(fio.sbi, NULL, fio.old_blkaddr, &newaddr,
+					&sum, CURSEG_COLD_DATA, NULL, false);
+
+	fio.encrypted_page = f2fs_pagecache_get_page(META_MAPPING(fio.sbi),
+				newaddr, FGP_LOCK | FGP_CREAT, GFP_NOFS);
+	if (!fio.encrypted_page) {
+		err = -ENOMEM;
+		goto recover_block;
+	}
+
+	err = f2fs_submit_page_bio(&fio);
+	if (err)
+		goto put_page_out;
+
+	/* write page */
+	lock_page(fio.encrypted_page);
+
+	if (unlikely(fio.encrypted_page->mapping != META_MAPPING(fio.sbi))) {
+		err = -EIO;
+		goto put_page_out;
+	}
+	if (unlikely(!PageUptodate(fio.encrypted_page))) {
+		err = -EIO;
+		goto put_page_out;
+	}
+
+	set_page_dirty(fio.encrypted_page);
+	f2fs_wait_on_page_writeback(fio.encrypted_page, DATA, true);
+	if (clear_page_dirty_for_io(fio.encrypted_page))
+		dec_page_count(fio.sbi, F2FS_DIRTY_META);
+
+	set_page_writeback(fio.encrypted_page);
+	ClearPageError(page);
+
+	/* allocate block address */
+	f2fs_wait_on_page_writeback(dn.node_page, NODE, true);
+
+	fio.op = REQ_OP_WRITE;
+	fio.op_flags = REQ_SYNC;
+	fio.new_blkaddr = newaddr;
+	err = f2fs_submit_page_write(&fio);
+	if (err) {
+		if (PageWriteback(fio.encrypted_page))
+			end_page_writeback(fio.encrypted_page);
+		goto put_page_out;
+	}
+
+	f2fs_update_iostat(fio.sbi, FS_GC_DATA_IO, F2FS_BLKSIZE);
+
+	f2fs_update_data_blkaddr(&dn, newaddr);
+	set_inode_flag(inode, FI_APPEND_WRITE);
+	if (page->index == 0)
+		set_inode_flag(inode, FI_FIRST_BLOCK_WRITTEN);
+put_page_out:
+	f2fs_put_page(fio.encrypted_page, 1);
+recover_block:
+	if (err)
+		__f2fs_replace_block(fio.sbi, &sum, newaddr, fio.old_blkaddr,
+								true, true);
+put_out:
+	f2fs_put_dnode(&dn);
+out:
+	f2fs_put_page(page, 1);
+}
+
+static void move_data_page(struct inode *inode, block_t bidx, int gc_type,
+							unsigned int segno, int off)
+{
+	struct page *page;
+
+	page = get_lock_data_page(inode, bidx, true);
+	if (IS_ERR(page))
+		return;
+
+	if (!check_valid_map(F2FS_I_SB(inode), segno, off))
+		goto out;
+
+	if (f2fs_is_atomic_file(inode))
+		goto out;
+	if (f2fs_is_pinned_file(inode)) {
+		if (gc_type == FG_GC)
+			f2fs_pin_file_control(inode, true);
+		goto out;
+	}
+
+	if (gc_type == BG_GC) {
+		if (PageWriteback(page))
+			goto out;
+		set_page_dirty(page);
+		set_cold_data(page);
+	} else {
+		struct f2fs_io_info fio = {
+			.sbi = F2FS_I_SB(inode),
+			.ino = inode->i_ino,
+			.type = DATA,
+			.temp = COLD,
+			.op = REQ_OP_WRITE,
+			.op_flags = REQ_SYNC,
+			.old_blkaddr = NULL_ADDR,
+			.page = page,
+			.encrypted_page = NULL,
+			.need_lock = LOCK_REQ,
+			.io_type = FS_GC_DATA_IO,
+		};
+		bool is_dirty = PageDirty(page);
+		int err;
+
+retry:
+		set_page_dirty(page);
+		f2fs_wait_on_page_writeback(page, DATA, true);
+		if (clear_page_dirty_for_io(page)) {
+			inode_dec_dirty_pages(inode);
+			remove_dirty_inode(inode);
+		}
+
+		set_cold_data(page);
+
+		err = do_write_data_page(&fio);
+		if (err) {
+			clear_cold_data(page);
+			if (err == -ENOMEM) {
+				congestion_wait(BLK_RW_ASYNC, HZ/50);
+				goto retry;
+			}
+			if (is_dirty)
+				set_page_dirty(page);
+		}
+	}
+out:
+	f2fs_put_page(page, 1);
+}
+
+/*
+ * This function tries to get parent node of victim data block, and identifies
+ * data block validity. If the block is valid, copy that with cold status and
+ * modify parent node.
+ * If the parent node is not valid or the data block address is different,
+ * the victim data block is ignored.
+ */
+static void gc_data_segment(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
+		struct gc_inode_list *gc_list, unsigned int segno, int gc_type)
+{
+	struct super_block *sb = sbi->sb;
+	struct f2fs_summary *entry;
+	block_t start_addr;
+	int off;
+	int phase = 0;
+
+	start_addr = START_BLOCK(sbi, segno);
+
+next_step:
+	entry = sum;
+
+	for (off = 0; off < sbi->blocks_per_seg; off++, entry++) {
+		struct page *data_page;
+		struct inode *inode;
+		struct node_info dni; /* dnode info for the data */
+		unsigned int ofs_in_node, nofs;
+		block_t start_bidx;
+		nid_t nid = le32_to_cpu(entry->nid);
+
+		/* stop BG_GC if there is not enough free sections. */
+		if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0))
+			return;
+
+		if (check_valid_map(sbi, segno, off) == 0)
+			continue;
+
+		if (phase == 0) {
+			ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nid), 1,
+							META_NAT, true);
+			continue;
+		}
+
+		if (phase == 1) {
+			ra_node_page(sbi, nid);
+			continue;
+		}
+
+		/* Get an inode by ino with checking validity */
+		if (!is_alive(sbi, entry, &dni, start_addr + off, &nofs))
+			continue;
+
+		if (phase == 2) {
+			ra_node_page(sbi, dni.ino);
+			continue;
+		}
+
+		ofs_in_node = le16_to_cpu(entry->ofs_in_node);
+
+		if (phase == 3) {
+			inode = f2fs_iget(sb, dni.ino);
+			if (IS_ERR(inode) || is_bad_inode(inode))
+				continue;
+
+			/* if inode uses special I/O path, let's go phase 3 */
+			if (f2fs_post_read_required(inode)) {
+				add_gc_inode(gc_list, inode);
+				continue;
+			}
+
+			if (!down_write_trylock(
+				&F2FS_I(inode)->dio_rwsem[WRITE])) {
+				iput(inode);
+				continue;
+			}
+
+			start_bidx = start_bidx_of_node(nofs, inode);
+			data_page = get_read_data_page(inode,
+					start_bidx + ofs_in_node, REQ_RAHEAD,
+					true);
+			up_write(&F2FS_I(inode)->dio_rwsem[WRITE]);
+			if (IS_ERR(data_page)) {
+				iput(inode);
+				continue;
+			}
+
+			f2fs_put_page(data_page, 0);
+			add_gc_inode(gc_list, inode);
+			continue;
+		}
+
+		/* phase 4 */
+		inode = find_gc_inode(gc_list, dni.ino);
+		if (inode) {
+			struct f2fs_inode_info *fi = F2FS_I(inode);
+			bool locked = false;
+
+			if (S_ISREG(inode->i_mode)) {
+				if (!down_write_trylock(&fi->dio_rwsem[READ]))
+					continue;
+				if (!down_write_trylock(
+						&fi->dio_rwsem[WRITE])) {
+					up_write(&fi->dio_rwsem[READ]);
+					continue;
+				}
+				locked = true;
+
+				/* wait for all inflight aio data */
+				inode_dio_wait(inode);
+			}
+
+			start_bidx = start_bidx_of_node(nofs, inode)
+								+ ofs_in_node;
+			if (f2fs_post_read_required(inode))
+				move_data_block(inode, start_bidx, segno, off);
+			else
+				move_data_page(inode, start_bidx, gc_type,
+								segno, off);
+
+			if (locked) {
+				up_write(&fi->dio_rwsem[WRITE]);
+				up_write(&fi->dio_rwsem[READ]);
+			}
+
+			stat_inc_data_blk_count(sbi, 1, gc_type);
+		}
+	}
+
+	if (++phase < 5)
+		goto next_step;
+}
+
+static int __get_victim(struct f2fs_sb_info *sbi, unsigned int *victim,
+			int gc_type)
+{
+	struct sit_info *sit_i = SIT_I(sbi);
+	int ret;
+
+	down_write(&sit_i->sentry_lock);
+	ret = DIRTY_I(sbi)->v_ops->get_victim(sbi, victim, gc_type,
+					      NO_CHECK_TYPE, LFS);
+	up_write(&sit_i->sentry_lock);
+	return ret;
+}
+
+static int do_garbage_collect(struct f2fs_sb_info *sbi,
+				unsigned int start_segno,
+				struct gc_inode_list *gc_list, int gc_type)
+{
+	struct page *sum_page;
+	struct f2fs_summary_block *sum;
+	struct blk_plug plug;
+	unsigned int segno = start_segno;
+	unsigned int end_segno = start_segno + sbi->segs_per_sec;
+	int seg_freed = 0;
+	unsigned char type = IS_DATASEG(get_seg_entry(sbi, segno)->type) ?
+						SUM_TYPE_DATA : SUM_TYPE_NODE;
+
+	/* readahead multi ssa blocks those have contiguous address */
+	if (sbi->segs_per_sec > 1)
+		ra_meta_pages(sbi, GET_SUM_BLOCK(sbi, segno),
+					sbi->segs_per_sec, META_SSA, true);
+
+	/* reference all summary page */
+	while (segno < end_segno) {
+		sum_page = get_sum_page(sbi, segno++);
+		unlock_page(sum_page);
+	}
+
+	blk_start_plug(&plug);
+
+	for (segno = start_segno; segno < end_segno; segno++) {
+
+		/* find segment summary of victim */
+		sum_page = find_get_page(META_MAPPING(sbi),
+					GET_SUM_BLOCK(sbi, segno));
+		f2fs_put_page(sum_page, 0);
+
+		if (get_valid_blocks(sbi, segno, false) == 0)
+			goto freed;
+		if (!PageUptodate(sum_page) || unlikely(f2fs_cp_error(sbi)))
+			goto next;
+
+		sum = page_address(sum_page);
+		if (type != GET_SUM_TYPE((&sum->footer))) {
+			f2fs_msg(sbi->sb, KERN_ERR, "Inconsistent segment (%u) "
+				"type [%d, %d] in SSA and SIT",
+				segno, type, GET_SUM_TYPE((&sum->footer)));
+			set_sbi_flag(sbi, SBI_NEED_FSCK);
+			goto next;
+		}
+
+		/*
+		 * this is to avoid deadlock:
+		 * - lock_page(sum_page)         - f2fs_replace_block
+		 *  - check_valid_map()            - down_write(sentry_lock)
+		 *   - down_read(sentry_lock)     - change_curseg()
+		 *                                  - lock_page(sum_page)
+		 */
+		if (type == SUM_TYPE_NODE)
+			gc_node_segment(sbi, sum->entries, segno, gc_type);
+		else
+			gc_data_segment(sbi, sum->entries, gc_list, segno,
+								gc_type);
+
+		stat_inc_seg_count(sbi, type, gc_type);
+
+freed:
+		if (gc_type == FG_GC &&
+				get_valid_blocks(sbi, segno, false) == 0)
+			seg_freed++;
+next:
+		f2fs_put_page(sum_page, 0);
+	}
+
+	if (gc_type == FG_GC)
+		f2fs_submit_merged_write(sbi,
+				(type == SUM_TYPE_NODE) ? NODE : DATA);
+
+	blk_finish_plug(&plug);
+
+	stat_inc_call_count(sbi->stat_info);
+
+	return seg_freed;
+}
+
+int f2fs_gc(struct f2fs_sb_info *sbi, bool sync,
+			bool background, unsigned int segno)
+{
+	int gc_type = sync ? FG_GC : BG_GC;
+	int sec_freed = 0, seg_freed = 0, total_freed = 0;
+	int ret = 0;
+	struct cp_control cpc;
+	unsigned int init_segno = segno;
+	struct gc_inode_list gc_list = {
+		.ilist = LIST_HEAD_INIT(gc_list.ilist),
+		.iroot = RADIX_TREE_INIT(GFP_NOFS),
+	};
+
+	trace_f2fs_gc_begin(sbi->sb, sync, background,
+				get_pages(sbi, F2FS_DIRTY_NODES),
+				get_pages(sbi, F2FS_DIRTY_DENTS),
+				get_pages(sbi, F2FS_DIRTY_IMETA),
+				free_sections(sbi),
+				free_segments(sbi),
+				reserved_segments(sbi),
+				prefree_segments(sbi));
+
+	cpc.reason = __get_cp_reason(sbi);
+gc_more:
+	if (unlikely(!(sbi->sb->s_flags & MS_ACTIVE))) {
+		ret = -EINVAL;
+		goto stop;
+	}
+	if (unlikely(f2fs_cp_error(sbi))) {
+		ret = -EIO;
+		goto stop;
+	}
+
+	if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0)) {
+		/*
+		 * For example, if there are many prefree_segments below given
+		 * threshold, we can make them free by checkpoint. Then, we
+		 * secure free segments which doesn't need fggc any more.
+		 */
+		if (prefree_segments(sbi)) {
+			ret = write_checkpoint(sbi, &cpc);
+			if (ret)
+				goto stop;
+		}
+		if (has_not_enough_free_secs(sbi, 0, 0))
+			gc_type = FG_GC;
+	}
+
+	/* f2fs_balance_fs doesn't need to do BG_GC in critical path. */
+	if (gc_type == BG_GC && !background) {
+		ret = -EINVAL;
+		goto stop;
+	}
+	if (!__get_victim(sbi, &segno, gc_type)) {
+		ret = -ENODATA;
+		goto stop;
+	}
+
+	seg_freed = do_garbage_collect(sbi, segno, &gc_list, gc_type);
+	if (gc_type == FG_GC && seg_freed == sbi->segs_per_sec)
+		sec_freed++;
+	total_freed += seg_freed;
+
+	if (gc_type == FG_GC)
+		sbi->cur_victim_sec = NULL_SEGNO;
+
+	if (!sync) {
+		if (has_not_enough_free_secs(sbi, sec_freed, 0)) {
+			segno = NULL_SEGNO;
+			goto gc_more;
+		}
+
+		if (gc_type == FG_GC)
+			ret = write_checkpoint(sbi, &cpc);
+	}
+stop:
+	SIT_I(sbi)->last_victim[ALLOC_NEXT] = 0;
+	SIT_I(sbi)->last_victim[FLUSH_DEVICE] = init_segno;
+
+	trace_f2fs_gc_end(sbi->sb, ret, total_freed, sec_freed,
+				get_pages(sbi, F2FS_DIRTY_NODES),
+				get_pages(sbi, F2FS_DIRTY_DENTS),
+				get_pages(sbi, F2FS_DIRTY_IMETA),
+				free_sections(sbi),
+				free_segments(sbi),
+				reserved_segments(sbi),
+				prefree_segments(sbi));
+
+	mutex_unlock(&sbi->gc_mutex);
+
+	put_gc_inode(&gc_list);
+
+	if (sync && !ret)
+		ret = sec_freed ? 0 : -EAGAIN;
+	return ret;
+}
+
+void build_gc_manager(struct f2fs_sb_info *sbi)
+{
+	u64 main_count, resv_count, ovp_count;
+
+	DIRTY_I(sbi)->v_ops = &default_v_ops;
+
+	/* threshold of # of valid blocks in a section for victims of FG_GC */
+	main_count = SM_I(sbi)->main_segments << sbi->log_blocks_per_seg;
+	resv_count = SM_I(sbi)->reserved_segments << sbi->log_blocks_per_seg;
+	ovp_count = SM_I(sbi)->ovp_segments << sbi->log_blocks_per_seg;
+
+	sbi->fggc_threshold = div64_u64((main_count - ovp_count) *
+				BLKS_PER_SEC(sbi), (main_count - resv_count));
+	sbi->gc_pin_file_threshold = DEF_GC_FAILED_PINNED_FILES;
+
+	/* give warm/cold data area from slower device */
+	if (f2fs_is_multi_device(sbi) && sbi->segs_per_sec == 1)
+		SIT_I(sbi)->last_victim[ALLOC_NEXT] =
+				GET_SEGNO(sbi, FDEV(0).end_blk) + 1;
+}
diff --git a/src/kernel/linux/v4.14/fs/f2fs/gc.h b/src/kernel/linux/v4.14/fs/f2fs/gc.h
new file mode 100644
index 0000000..b0045d4
--- /dev/null
+++ b/src/kernel/linux/v4.14/fs/f2fs/gc.h
@@ -0,0 +1,115 @@
+/*
+ * fs/f2fs/gc.h
+ *
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ *             http://www.samsung.com/
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#define GC_THREAD_MIN_WB_PAGES		1	/*
+						 * a threshold to determine
+						 * whether IO subsystem is idle
+						 * or not
+						 */
+#define DEF_GC_THREAD_URGENT_SLEEP_TIME	500	/* 500 ms */
+#define DEF_GC_THREAD_MIN_SLEEP_TIME	30000	/* milliseconds */
+#define DEF_GC_THREAD_MAX_SLEEP_TIME	60000
+#define DEF_GC_THREAD_NOGC_SLEEP_TIME	300000	/* wait 5 min */
+#define LIMIT_INVALID_BLOCK	40 /* percentage over total user space */
+#define LIMIT_FREE_BLOCK	40 /* percentage over invalid + free space */
+
+#define DEF_GC_FAILED_PINNED_FILES	2048
+
+/* Search max. number of dirty segments to select a victim segment */
+#define DEF_MAX_VICTIM_SEARCH 4096 /* covers 8GB */
+
+struct f2fs_gc_kthread {
+	struct task_struct *f2fs_gc_task;
+	wait_queue_head_t gc_wait_queue_head;
+
+	/* for gc sleep time */
+	unsigned int urgent_sleep_time;
+	unsigned int min_sleep_time;
+	unsigned int max_sleep_time;
+	unsigned int no_gc_sleep_time;
+
+	/* for changing gc mode */
+	unsigned int gc_idle;
+	unsigned int gc_urgent;
+	unsigned int gc_wake;
+};
+
+struct gc_inode_list {
+	struct list_head ilist;
+	struct radix_tree_root iroot;
+};
+
+/*
+ * inline functions
+ */
+static inline block_t free_user_blocks(struct f2fs_sb_info *sbi)
+{
+	if (free_segments(sbi) < overprovision_segments(sbi))
+		return 0;
+	else
+		return (free_segments(sbi) - overprovision_segments(sbi))
+			<< sbi->log_blocks_per_seg;
+}
+
+static inline block_t limit_invalid_user_blocks(struct f2fs_sb_info *sbi)
+{
+	return (long)(sbi->user_block_count * LIMIT_INVALID_BLOCK) / 100;
+}
+
+static inline block_t limit_free_user_blocks(struct f2fs_sb_info *sbi)
+{
+	block_t reclaimable_user_blocks = sbi->user_block_count -
+		written_block_count(sbi);
+	return (long)(reclaimable_user_blocks * LIMIT_FREE_BLOCK) / 100;
+}
+
+static inline void increase_sleep_time(struct f2fs_gc_kthread *gc_th,
+							unsigned int *wait)
+{
+	unsigned int min_time = gc_th->min_sleep_time;
+	unsigned int max_time = gc_th->max_sleep_time;
+
+	if (*wait == gc_th->no_gc_sleep_time)
+		return;
+
+	if ((long long)*wait + (long long)min_time > (long long)max_time)
+		*wait = max_time;
+	else
+		*wait += min_time;
+}
+
+static inline void decrease_sleep_time(struct f2fs_gc_kthread *gc_th,
+							unsigned int *wait)
+{
+	unsigned int min_time = gc_th->min_sleep_time;
+
+	if (*wait == gc_th->no_gc_sleep_time)
+		*wait = gc_th->max_sleep_time;
+
+	if ((long long)*wait - (long long)min_time < (long long)min_time)
+		*wait = min_time;
+	else
+		*wait -= min_time;
+}
+
+static inline bool has_enough_invalid_blocks(struct f2fs_sb_info *sbi)
+{
+	block_t invalid_user_blocks = sbi->user_block_count -
+					written_block_count(sbi);
+	/*
+	 * Background GC is triggered with the following conditions.
+	 * 1. There are a number of invalid blocks.
+	 * 2. There is not enough free space.
+	 */
+	if (invalid_user_blocks > limit_invalid_user_blocks(sbi) &&
+			free_user_blocks(sbi) < limit_free_user_blocks(sbi))
+		return true;
+	return false;
+}
diff --git a/src/kernel/linux/v4.14/fs/f2fs/hash.c b/src/kernel/linux/v4.14/fs/f2fs/hash.c
new file mode 100644
index 0000000..eb2e031
--- /dev/null
+++ b/src/kernel/linux/v4.14/fs/f2fs/hash.c
@@ -0,0 +1,108 @@
+/*
+ * fs/f2fs/hash.c
+ *
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ *             http://www.samsung.com/
+ *
+ * Portions of this code from linux/fs/ext3/hash.c
+ *
+ * Copyright (C) 2002 by Theodore Ts'o
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/types.h>
+#include <linux/fs.h>
+#include <linux/f2fs_fs.h>
+#include <linux/cryptohash.h>
+#include <linux/pagemap.h>
+
+#include "f2fs.h"
+
+/*
+ * Hashing code copied from ext3
+ */
+#define DELTA 0x9E3779B9
+
+static void TEA_transform(unsigned int buf[4], unsigned int const in[])
+{
+	__u32 sum = 0;
+	__u32 b0 = buf[0], b1 = buf[1];
+	__u32 a = in[0], b = in[1], c = in[2], d = in[3];
+	int n = 16;
+
+	do {
+		sum += DELTA;
+		b0 += ((b1 << 4)+a) ^ (b1+sum) ^ ((b1 >> 5)+b);
+		b1 += ((b0 << 4)+c) ^ (b0+sum) ^ ((b0 >> 5)+d);
+	} while (--n);
+
+	buf[0] += b0;
+	buf[1] += b1;
+}
+
+static void str2hashbuf(const unsigned char *msg, size_t len,
+				unsigned int *buf, int num)
+{
+	unsigned pad, val;
+	int i;
+
+	pad = (__u32)len | ((__u32)len << 8);
+	pad |= pad << 16;
+
+	val = pad;
+	if (len > num * 4)
+		len = num * 4;
+	for (i = 0; i < len; i++) {
+		if ((i % 4) == 0)
+			val = pad;
+		val = msg[i] + (val << 8);
+		if ((i % 4) == 3) {
+			*buf++ = val;
+			val = pad;
+			num--;
+		}
+	}
+	if (--num >= 0)
+		*buf++ = val;
+	while (--num >= 0)
+		*buf++ = pad;
+}
+
+f2fs_hash_t f2fs_dentry_hash(const struct qstr *name_info,
+				struct fscrypt_name *fname)
+{
+	__u32 hash;
+	f2fs_hash_t f2fs_hash;
+	const unsigned char *p;
+	__u32 in[8], buf[4];
+	const unsigned char *name = name_info->name;
+	size_t len = name_info->len;
+
+	/* encrypted bigname case */
+	if (fname && !fname->disk_name.name)
+		return cpu_to_le32(fname->hash);
+
+	if (is_dot_dotdot(name_info))
+		return 0;
+
+	/* Initialize the default seed for the hash checksum functions */
+	buf[0] = 0x67452301;
+	buf[1] = 0xefcdab89;
+	buf[2] = 0x98badcfe;
+	buf[3] = 0x10325476;
+
+	p = name;
+	while (1) {
+		str2hashbuf(p, len, in, 4);
+		TEA_transform(buf, in);
+		p += 16;
+		if (len <= 16)
+			break;
+		len -= 16;
+	}
+	hash = buf[0];
+	f2fs_hash = cpu_to_le32(hash & ~F2FS_HASH_COL_BIT);
+	return f2fs_hash;
+}
diff --git a/src/kernel/linux/v4.14/fs/f2fs/inline.c b/src/kernel/linux/v4.14/fs/f2fs/inline.c
new file mode 100644
index 0000000..d65dd11
--- /dev/null
+++ b/src/kernel/linux/v4.14/fs/f2fs/inline.c
@@ -0,0 +1,730 @@
+/*
+ * fs/f2fs/inline.c
+ * Copyright (c) 2013, Intel Corporation
+ * Authors: Huajun Li <huajun.li@intel.com>
+ *          Haicheng Li <haicheng.li@intel.com>
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/fs.h>
+#include <linux/f2fs_fs.h>
+
+#include "f2fs.h"
+#include "node.h"
+#include <trace/events/android_fs.h>
+
+bool f2fs_may_inline_data(struct inode *inode)
+{
+	if (f2fs_is_atomic_file(inode))
+		return false;
+
+	if (!S_ISREG(inode->i_mode) && !S_ISLNK(inode->i_mode))
+		return false;
+
+	if (i_size_read(inode) > MAX_INLINE_DATA(inode))
+		return false;
+
+	if (f2fs_post_read_required(inode))
+		return false;
+
+	return true;
+}
+
+bool f2fs_may_inline_dentry(struct inode *inode)
+{
+	if (!test_opt(F2FS_I_SB(inode), INLINE_DENTRY))
+		return false;
+
+	if (!S_ISDIR(inode->i_mode))
+		return false;
+
+	return true;
+}
+
+void read_inline_data(struct page *page, struct page *ipage)
+{
+	struct inode *inode = page->mapping->host;
+	void *src_addr, *dst_addr;
+
+	if (PageUptodate(page))
+		return;
+
+	f2fs_bug_on(F2FS_P_SB(page), page->index);
+
+	zero_user_segment(page, MAX_INLINE_DATA(inode), PAGE_SIZE);
+
+	/* Copy the whole inline data block */
+	src_addr = inline_data_addr(inode, ipage);
+	dst_addr = kmap_atomic(page);
+	memcpy(dst_addr, src_addr, MAX_INLINE_DATA(inode));
+	flush_dcache_page(page);
+	kunmap_atomic(dst_addr);
+	if (!PageUptodate(page))
+		SetPageUptodate(page);
+}
+
+void truncate_inline_inode(struct inode *inode, struct page *ipage, u64 from)
+{
+	void *addr;
+
+	if (from >= MAX_INLINE_DATA(inode))
+		return;
+
+	addr = inline_data_addr(inode, ipage);
+
+	f2fs_wait_on_page_writeback(ipage, NODE, true);
+	memset(addr + from, 0, MAX_INLINE_DATA(inode) - from);
+	set_page_dirty(ipage);
+
+	if (from == 0)
+		clear_inode_flag(inode, FI_DATA_EXIST);
+}
+
+int f2fs_read_inline_data(struct inode *inode, struct page *page)
+{
+	struct page *ipage;
+
+	if (trace_android_fs_dataread_start_enabled()) {
+		char *path, pathbuf[MAX_TRACE_PATHBUF_LEN];
+
+		path = android_fstrace_get_pathname(pathbuf,
+						    MAX_TRACE_PATHBUF_LEN,
+						    inode);
+		trace_android_fs_dataread_start(inode, page_offset(page),
+						PAGE_SIZE, current->pid,
+						path, current->comm);
+	}
+
+	ipage = get_node_page(F2FS_I_SB(inode), inode->i_ino);
+	if (IS_ERR(ipage)) {
+		trace_android_fs_dataread_end(inode, page_offset(page),
+					      PAGE_SIZE);
+		unlock_page(page);
+		return PTR_ERR(ipage);
+	}
+
+	if (!f2fs_has_inline_data(inode)) {
+		f2fs_put_page(ipage, 1);
+		trace_android_fs_dataread_end(inode, page_offset(page),
+					      PAGE_SIZE);
+		return -EAGAIN;
+	}
+
+	if (page->index)
+		zero_user_segment(page, 0, PAGE_SIZE);
+	else
+		read_inline_data(page, ipage);
+
+	if (!PageUptodate(page))
+		SetPageUptodate(page);
+	f2fs_put_page(ipage, 1);
+	trace_android_fs_dataread_end(inode, page_offset(page),
+				      PAGE_SIZE);
+	unlock_page(page);
+	return 0;
+}
+
+int f2fs_convert_inline_page(struct dnode_of_data *dn, struct page *page)
+{
+	struct f2fs_io_info fio = {
+		.sbi = F2FS_I_SB(dn->inode),
+		.ino = dn->inode->i_ino,
+		.type = DATA,
+		.op = REQ_OP_WRITE,
+		.op_flags = REQ_SYNC | REQ_PRIO,
+		.page = page,
+		.encrypted_page = NULL,
+		.io_type = FS_DATA_IO,
+	};
+	int dirty, err;
+
+	if (!f2fs_exist_data(dn->inode))
+		goto clear_out;
+
+	err = f2fs_reserve_block(dn, 0);
+	if (err)
+		return err;
+
+	if (unlikely(dn->data_blkaddr != NEW_ADDR)) {
+		f2fs_put_dnode(dn);
+		set_sbi_flag(fio.sbi, SBI_NEED_FSCK);
+		f2fs_msg(fio.sbi->sb, KERN_WARNING,
+			"%s: corrupted inline inode ino=%lx, i_addr[0]:0x%x, "
+			"run fsck to fix.",
+			__func__, dn->inode->i_ino, dn->data_blkaddr);
+		return -EFSCORRUPTED;
+	}
+
+	f2fs_bug_on(F2FS_P_SB(page), PageWriteback(page));
+
+	read_inline_data(page, dn->inode_page);
+	set_page_dirty(page);
+
+	/* clear dirty state */
+	dirty = clear_page_dirty_for_io(page);
+
+	/* write data page to try to make data consistent */
+	set_page_writeback(page);
+	ClearPageError(page);
+	fio.old_blkaddr = dn->data_blkaddr;
+	set_inode_flag(dn->inode, FI_HOT_DATA);
+	write_data_page(dn, &fio);
+	f2fs_wait_on_page_writeback(page, DATA, true);
+	if (dirty) {
+		inode_dec_dirty_pages(dn->inode);
+		remove_dirty_inode(dn->inode);
+	}
+
+	/* this converted inline_data should be recovered. */
+	set_inode_flag(dn->inode, FI_APPEND_WRITE);
+
+	/* clear inline data and flag after data writeback */
+	truncate_inline_inode(dn->inode, dn->inode_page, 0);
+	clear_inline_node(dn->inode_page);
+clear_out:
+	stat_dec_inline_inode(dn->inode);
+	clear_inode_flag(dn->inode, FI_INLINE_DATA);
+	f2fs_put_dnode(dn);
+	return 0;
+}
+
+int f2fs_convert_inline_inode(struct inode *inode)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct dnode_of_data dn;
+	struct page *ipage, *page;
+	int err = 0;
+
+	if (!f2fs_has_inline_data(inode))
+		return 0;
+
+	page = f2fs_grab_cache_page(inode->i_mapping, 0, false);
+	if (!page)
+		return -ENOMEM;
+
+	f2fs_lock_op(sbi);
+
+	ipage = get_node_page(sbi, inode->i_ino);
+	if (IS_ERR(ipage)) {
+		err = PTR_ERR(ipage);
+		goto out;
+	}
+
+	set_new_dnode(&dn, inode, ipage, ipage, 0);
+
+	if (f2fs_has_inline_data(inode))
+		err = f2fs_convert_inline_page(&dn, page);
+
+	f2fs_put_dnode(&dn);
+out:
+	f2fs_unlock_op(sbi);
+
+	f2fs_put_page(page, 1);
+
+	f2fs_balance_fs(sbi, dn.node_changed);
+
+	return err;
+}
+
+int f2fs_write_inline_data(struct inode *inode, struct page *page)
+{
+	void *src_addr, *dst_addr;
+	struct dnode_of_data dn;
+	struct address_space *mapping = page_mapping(page);
+	unsigned long flags;
+	int err;
+
+	set_new_dnode(&dn, inode, NULL, NULL, 0);
+	err = get_dnode_of_data(&dn, 0, LOOKUP_NODE);
+	if (err)
+		return err;
+
+	if (!f2fs_has_inline_data(inode)) {
+		f2fs_put_dnode(&dn);
+		return -EAGAIN;
+	}
+
+	f2fs_bug_on(F2FS_I_SB(inode), page->index);
+
+	f2fs_wait_on_page_writeback(dn.inode_page, NODE, true);
+	src_addr = kmap_atomic(page);
+	dst_addr = inline_data_addr(inode, dn.inode_page);
+	memcpy(dst_addr, src_addr, MAX_INLINE_DATA(inode));
+	kunmap_atomic(src_addr);
+	set_page_dirty(dn.inode_page);
+
+	spin_lock_irqsave(&mapping->tree_lock, flags);
+	radix_tree_tag_clear(&mapping->page_tree, page_index(page),
+			     PAGECACHE_TAG_DIRTY);
+	spin_unlock_irqrestore(&mapping->tree_lock, flags);
+
+	set_inode_flag(inode, FI_APPEND_WRITE);
+	set_inode_flag(inode, FI_DATA_EXIST);
+
+	clear_inline_node(dn.inode_page);
+	f2fs_put_dnode(&dn);
+	return 0;
+}
+
+bool recover_inline_data(struct inode *inode, struct page *npage)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct f2fs_inode *ri = NULL;
+	void *src_addr, *dst_addr;
+	struct page *ipage;
+
+	/*
+	 * The inline_data recovery policy is as follows.
+	 * [prev.] [next] of inline_data flag
+	 *    o       o  -> recover inline_data
+	 *    o       x  -> remove inline_data, and then recover data blocks
+	 *    x       o  -> remove inline_data, and then recover inline_data
+	 *    x       x  -> recover data blocks
+	 */
+	if (IS_INODE(npage))
+		ri = F2FS_INODE(npage);
+
+	if (f2fs_has_inline_data(inode) &&
+			ri && (ri->i_inline & F2FS_INLINE_DATA)) {
+process_inline:
+		ipage = get_node_page(sbi, inode->i_ino);
+		f2fs_bug_on(sbi, IS_ERR(ipage));
+
+		f2fs_wait_on_page_writeback(ipage, NODE, true);
+
+		src_addr = inline_data_addr(inode, npage);
+		dst_addr = inline_data_addr(inode, ipage);
+		memcpy(dst_addr, src_addr, MAX_INLINE_DATA(inode));
+
+		set_inode_flag(inode, FI_INLINE_DATA);
+		set_inode_flag(inode, FI_DATA_EXIST);
+
+		set_page_dirty(ipage);
+		f2fs_put_page(ipage, 1);
+		return true;
+	}
+
+	if (f2fs_has_inline_data(inode)) {
+		ipage = get_node_page(sbi, inode->i_ino);
+		f2fs_bug_on(sbi, IS_ERR(ipage));
+		truncate_inline_inode(inode, ipage, 0);
+		clear_inode_flag(inode, FI_INLINE_DATA);
+		f2fs_put_page(ipage, 1);
+	} else if (ri && (ri->i_inline & F2FS_INLINE_DATA)) {
+		if (truncate_blocks(inode, 0, false))
+			return false;
+		goto process_inline;
+	}
+	return false;
+}
+
+struct f2fs_dir_entry *find_in_inline_dir(struct inode *dir,
+			struct fscrypt_name *fname, struct page **res_page)
+{
+	struct f2fs_sb_info *sbi = F2FS_SB(dir->i_sb);
+	struct qstr name = FSTR_TO_QSTR(&fname->disk_name);
+	struct f2fs_dir_entry *de;
+	struct f2fs_dentry_ptr d;
+	struct page *ipage;
+	void *inline_dentry;
+	f2fs_hash_t namehash;
+
+	ipage = get_node_page(sbi, dir->i_ino);
+	if (IS_ERR(ipage)) {
+		*res_page = ipage;
+		return NULL;
+	}
+
+	namehash = f2fs_dentry_hash(&name, fname);
+
+	inline_dentry = inline_data_addr(dir, ipage);
+
+	make_dentry_ptr_inline(dir, &d, inline_dentry);
+	de = find_target_dentry(fname, namehash, NULL, &d);
+	unlock_page(ipage);
+	if (de)
+		*res_page = ipage;
+	else
+		f2fs_put_page(ipage, 0);
+
+	return de;
+}
+
+int make_empty_inline_dir(struct inode *inode, struct inode *parent,
+							struct page *ipage)
+{
+	struct f2fs_dentry_ptr d;
+	void *inline_dentry;
+
+	inline_dentry = inline_data_addr(inode, ipage);
+
+	make_dentry_ptr_inline(inode, &d, inline_dentry);
+	do_make_empty_dir(inode, parent, &d);
+
+	set_page_dirty(ipage);
+
+	/* update i_size to MAX_INLINE_DATA */
+	if (i_size_read(inode) < MAX_INLINE_DATA(inode))
+		f2fs_i_size_write(inode, MAX_INLINE_DATA(inode));
+	return 0;
+}
+
+/*
+ * NOTE: ipage is grabbed by caller, but if any error occurs, we should
+ * release ipage in this function.
+ */
+static int f2fs_move_inline_dirents(struct inode *dir, struct page *ipage,
+							void *inline_dentry)
+{
+	struct page *page;
+	struct dnode_of_data dn;
+	struct f2fs_dentry_block *dentry_blk;
+	struct f2fs_dentry_ptr src, dst;
+	int err;
+
+	page = f2fs_grab_cache_page(dir->i_mapping, 0, false);
+	if (!page) {
+		f2fs_put_page(ipage, 1);
+		return -ENOMEM;
+	}
+
+	set_new_dnode(&dn, dir, ipage, NULL, 0);
+	err = f2fs_reserve_block(&dn, 0);
+	if (err)
+		goto out;
+
+	if (unlikely(dn.data_blkaddr != NEW_ADDR)) {
+		f2fs_put_dnode(&dn);
+		set_sbi_flag(F2FS_P_SB(page), SBI_NEED_FSCK);
+		f2fs_msg(F2FS_P_SB(page)->sb, KERN_WARNING,
+			"%s: corrupted inline inode ino=%lx, i_addr[0]:0x%x, "
+			"run fsck to fix.",
+			__func__, dir->i_ino, dn.data_blkaddr);
+		err = -EFSCORRUPTED;
+		goto out;
+	}
+
+	f2fs_wait_on_page_writeback(page, DATA, true);
+	zero_user_segment(page, MAX_INLINE_DATA(dir), PAGE_SIZE);
+
+	dentry_blk = page_address(page);
+
+	make_dentry_ptr_inline(dir, &src, inline_dentry);
+	make_dentry_ptr_block(dir, &dst, dentry_blk);
+
+	/* copy data from inline dentry block to new dentry block */
+	memcpy(dst.bitmap, src.bitmap, src.nr_bitmap);
+	memset(dst.bitmap + src.nr_bitmap, 0, dst.nr_bitmap - src.nr_bitmap);
+	/*
+	 * we do not need to zero out remainder part of dentry and filename
+	 * field, since we have used bitmap for marking the usage status of
+	 * them, besides, we can also ignore copying/zeroing reserved space
+	 * of dentry block, because them haven't been used so far.
+	 */
+	memcpy(dst.dentry, src.dentry, SIZE_OF_DIR_ENTRY * src.max);
+	memcpy(dst.filename, src.filename, src.max * F2FS_SLOT_LEN);
+
+	if (!PageUptodate(page))
+		SetPageUptodate(page);
+	set_page_dirty(page);
+
+	/* clear inline dir and flag after data writeback */
+	truncate_inline_inode(dir, ipage, 0);
+
+	stat_dec_inline_dir(dir);
+	clear_inode_flag(dir, FI_INLINE_DENTRY);
+
+	f2fs_i_depth_write(dir, 1);
+	if (i_size_read(dir) < PAGE_SIZE)
+		f2fs_i_size_write(dir, PAGE_SIZE);
+out:
+	f2fs_put_page(page, 1);
+	return err;
+}
+
+static int f2fs_add_inline_entries(struct inode *dir, void *inline_dentry)
+{
+	struct f2fs_dentry_ptr d;
+	unsigned long bit_pos = 0;
+	int err = 0;
+
+	make_dentry_ptr_inline(dir, &d, inline_dentry);
+
+	while (bit_pos < d.max) {
+		struct f2fs_dir_entry *de;
+		struct qstr new_name;
+		nid_t ino;
+		umode_t fake_mode;
+
+		if (!test_bit_le(bit_pos, d.bitmap)) {
+			bit_pos++;
+			continue;
+		}
+
+		de = &d.dentry[bit_pos];
+
+		if (unlikely(!de->name_len)) {
+			bit_pos++;
+			continue;
+		}
+
+		new_name.name = d.filename[bit_pos];
+		new_name.len = le16_to_cpu(de->name_len);
+
+		ino = le32_to_cpu(de->ino);
+		fake_mode = get_de_type(de) << S_SHIFT;
+
+		err = f2fs_add_regular_entry(dir, &new_name, NULL, NULL,
+							ino, fake_mode);
+		if (err)
+			goto punch_dentry_pages;
+
+		bit_pos += GET_DENTRY_SLOTS(le16_to_cpu(de->name_len));
+	}
+	return 0;
+punch_dentry_pages:
+	truncate_inode_pages(&dir->i_data, 0);
+	truncate_blocks(dir, 0, false);
+	remove_dirty_inode(dir);
+	return err;
+}
+
+static int f2fs_move_rehashed_dirents(struct inode *dir, struct page *ipage,
+							void *inline_dentry)
+{
+	void *backup_dentry;
+	int err;
+
+	backup_dentry = f2fs_kmalloc(F2FS_I_SB(dir),
+				MAX_INLINE_DATA(dir), GFP_F2FS_ZERO);
+	if (!backup_dentry) {
+		f2fs_put_page(ipage, 1);
+		return -ENOMEM;
+	}
+
+	memcpy(backup_dentry, inline_dentry, MAX_INLINE_DATA(dir));
+	truncate_inline_inode(dir, ipage, 0);
+
+	unlock_page(ipage);
+
+	err = f2fs_add_inline_entries(dir, backup_dentry);
+	if (err)
+		goto recover;
+
+	lock_page(ipage);
+
+	stat_dec_inline_dir(dir);
+	clear_inode_flag(dir, FI_INLINE_DENTRY);
+	kfree(backup_dentry);
+	return 0;
+recover:
+	lock_page(ipage);
+	f2fs_wait_on_page_writeback(ipage, NODE, true);
+	memcpy(inline_dentry, backup_dentry, MAX_INLINE_DATA(dir));
+	f2fs_i_depth_write(dir, 0);
+	f2fs_i_size_write(dir, MAX_INLINE_DATA(dir));
+	set_page_dirty(ipage);
+	f2fs_put_page(ipage, 1);
+
+	kfree(backup_dentry);
+	return err;
+}
+
+static int f2fs_convert_inline_dir(struct inode *dir, struct page *ipage,
+							void *inline_dentry)
+{
+	if (!F2FS_I(dir)->i_dir_level)
+		return f2fs_move_inline_dirents(dir, ipage, inline_dentry);
+	else
+		return f2fs_move_rehashed_dirents(dir, ipage, inline_dentry);
+}
+
+int f2fs_add_inline_entry(struct inode *dir, const struct qstr *new_name,
+				const struct qstr *orig_name,
+				struct inode *inode, nid_t ino, umode_t mode)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
+	struct page *ipage;
+	unsigned int bit_pos;
+	f2fs_hash_t name_hash;
+	void *inline_dentry = NULL;
+	struct f2fs_dentry_ptr d;
+	int slots = GET_DENTRY_SLOTS(new_name->len);
+	struct page *page = NULL;
+	int err = 0;
+
+	ipage = get_node_page(sbi, dir->i_ino);
+	if (IS_ERR(ipage))
+		return PTR_ERR(ipage);
+
+	inline_dentry = inline_data_addr(dir, ipage);
+	make_dentry_ptr_inline(dir, &d, inline_dentry);
+
+	bit_pos = room_for_filename(d.bitmap, slots, d.max);
+	if (bit_pos >= d.max) {
+		err = f2fs_convert_inline_dir(dir, ipage, inline_dentry);
+		if (err)
+			return err;
+		err = -EAGAIN;
+		goto out;
+	}
+
+	if (inode) {
+		down_write(&F2FS_I(inode)->i_sem);
+		page = init_inode_metadata(inode, dir, new_name,
+						orig_name, ipage);
+		if (IS_ERR(page)) {
+			err = PTR_ERR(page);
+			goto fail;
+		}
+	}
+
+	f2fs_wait_on_page_writeback(ipage, NODE, true);
+
+	name_hash = f2fs_dentry_hash(new_name, NULL);
+	f2fs_update_dentry(ino, mode, &d, new_name, name_hash, bit_pos);
+
+	set_page_dirty(ipage);
+
+	/* we don't need to mark_inode_dirty now */
+	if (inode) {
+		f2fs_i_pino_write(inode, dir->i_ino);
+		f2fs_put_page(page, 1);
+	}
+
+	update_parent_metadata(dir, inode, 0);
+fail:
+	if (inode)
+		up_write(&F2FS_I(inode)->i_sem);
+out:
+	f2fs_put_page(ipage, 1);
+	return err;
+}
+
+void f2fs_delete_inline_entry(struct f2fs_dir_entry *dentry, struct page *page,
+					struct inode *dir, struct inode *inode)
+{
+	struct f2fs_dentry_ptr d;
+	void *inline_dentry;
+	int slots = GET_DENTRY_SLOTS(le16_to_cpu(dentry->name_len));
+	unsigned int bit_pos;
+	int i;
+
+	lock_page(page);
+	f2fs_wait_on_page_writeback(page, NODE, true);
+
+	inline_dentry = inline_data_addr(dir, page);
+	make_dentry_ptr_inline(dir, &d, inline_dentry);
+
+	bit_pos = dentry - d.dentry;
+	for (i = 0; i < slots; i++)
+		__clear_bit_le(bit_pos + i, d.bitmap);
+
+	set_page_dirty(page);
+	f2fs_put_page(page, 1);
+
+	dir->i_ctime = dir->i_mtime = current_time(dir);
+	f2fs_mark_inode_dirty_sync(dir, false);
+
+	if (inode)
+		f2fs_drop_nlink(dir, inode);
+}
+
+bool f2fs_empty_inline_dir(struct inode *dir)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
+	struct page *ipage;
+	unsigned int bit_pos = 2;
+	void *inline_dentry;
+	struct f2fs_dentry_ptr d;
+
+	ipage = get_node_page(sbi, dir->i_ino);
+	if (IS_ERR(ipage))
+		return false;
+
+	inline_dentry = inline_data_addr(dir, ipage);
+	make_dentry_ptr_inline(dir, &d, inline_dentry);
+
+	bit_pos = find_next_bit_le(d.bitmap, d.max, bit_pos);
+
+	f2fs_put_page(ipage, 1);
+
+	if (bit_pos < d.max)
+		return false;
+
+	return true;
+}
+
+int f2fs_read_inline_dir(struct file *file, struct dir_context *ctx,
+				struct fscrypt_str *fstr)
+{
+	struct inode *inode = file_inode(file);
+	struct page *ipage = NULL;
+	struct f2fs_dentry_ptr d;
+	void *inline_dentry = NULL;
+	int err;
+
+	make_dentry_ptr_inline(inode, &d, inline_dentry);
+
+	if (ctx->pos == d.max)
+		return 0;
+
+	ipage = get_node_page(F2FS_I_SB(inode), inode->i_ino);
+	if (IS_ERR(ipage))
+		return PTR_ERR(ipage);
+
+	/*
+	 * f2fs_readdir was protected by inode.i_rwsem, it is safe to access
+	 * ipage without page's lock held.
+	 */
+	unlock_page(ipage);
+
+	inline_dentry = inline_data_addr(inode, ipage);
+
+	make_dentry_ptr_inline(inode, &d, inline_dentry);
+
+	err = f2fs_fill_dentries(ctx, &d, 0, fstr);
+	if (!err)
+		ctx->pos = d.max;
+
+	f2fs_put_page(ipage, 0);
+	return err < 0 ? err : 0;
+}
+
+int f2fs_inline_data_fiemap(struct inode *inode,
+		struct fiemap_extent_info *fieinfo, __u64 start, __u64 len)
+{
+	__u64 byteaddr, ilen;
+	__u32 flags = FIEMAP_EXTENT_DATA_INLINE | FIEMAP_EXTENT_NOT_ALIGNED |
+		FIEMAP_EXTENT_LAST;
+	struct node_info ni;
+	struct page *ipage;
+	int err = 0;
+
+	ipage = get_node_page(F2FS_I_SB(inode), inode->i_ino);
+	if (IS_ERR(ipage))
+		return PTR_ERR(ipage);
+
+	if (!f2fs_has_inline_data(inode)) {
+		err = -EAGAIN;
+		goto out;
+	}
+
+	ilen = min_t(size_t, MAX_INLINE_DATA(inode), i_size_read(inode));
+	if (start >= ilen)
+		goto out;
+	if (start + len < ilen)
+		ilen = start + len;
+	ilen -= start;
+
+	get_node_info(F2FS_I_SB(inode), inode->i_ino, &ni);
+	byteaddr = (__u64)ni.blk_addr << inode->i_sb->s_blocksize_bits;
+	byteaddr += (char *)inline_data_addr(inode, ipage) -
+					(char *)F2FS_INODE(ipage);
+	err = fiemap_fill_next_extent(fieinfo, start, byteaddr, ilen, flags);
+out:
+	f2fs_put_page(ipage, 1);
+	return err;
+}
diff --git a/src/kernel/linux/v4.14/fs/f2fs/inode.c b/src/kernel/linux/v4.14/fs/f2fs/inode.c
new file mode 100644
index 0000000..ff7eab5
--- /dev/null
+++ b/src/kernel/linux/v4.14/fs/f2fs/inode.c
@@ -0,0 +1,726 @@
+/*
+ * fs/f2fs/inode.c
+ *
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ *             http://www.samsung.com/
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/fs.h>
+#include <linux/f2fs_fs.h>
+#include <linux/buffer_head.h>
+#include <linux/backing-dev.h>
+#include <linux/writeback.h>
+
+#include "f2fs.h"
+#include "node.h"
+#include "segment.h"
+
+#include <trace/events/f2fs.h>
+
+void f2fs_mark_inode_dirty_sync(struct inode *inode, bool sync)
+{
+	if (is_inode_flag_set(inode, FI_NEW_INODE))
+		return;
+
+	if (f2fs_inode_dirtied(inode, sync))
+		return;
+
+	mark_inode_dirty_sync(inode);
+}
+
+void f2fs_set_inode_flags(struct inode *inode)
+{
+	unsigned int flags = F2FS_I(inode)->i_flags;
+	unsigned int new_fl = 0;
+
+	if (flags & FS_SYNC_FL)
+		new_fl |= S_SYNC;
+	if (flags & FS_APPEND_FL)
+		new_fl |= S_APPEND;
+	if (flags & FS_IMMUTABLE_FL)
+		new_fl |= S_IMMUTABLE;
+	if (flags & FS_NOATIME_FL)
+		new_fl |= S_NOATIME;
+	if (flags & FS_DIRSYNC_FL)
+		new_fl |= S_DIRSYNC;
+	if (f2fs_encrypted_inode(inode))
+		new_fl |= S_ENCRYPTED;
+	inode_set_flags(inode, new_fl,
+			S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC|
+			S_ENCRYPTED);
+}
+
+static void __get_inode_rdev(struct inode *inode, struct f2fs_inode *ri)
+{
+	int extra_size = get_extra_isize(inode);
+
+	if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
+			S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
+		if (ri->i_addr[extra_size])
+			inode->i_rdev = old_decode_dev(
+				le32_to_cpu(ri->i_addr[extra_size]));
+		else
+			inode->i_rdev = new_decode_dev(
+				le32_to_cpu(ri->i_addr[extra_size + 1]));
+	}
+}
+
+static int __written_first_block(struct f2fs_sb_info *sbi,
+					struct f2fs_inode *ri)
+{
+	block_t addr = le32_to_cpu(ri->i_addr[offset_in_addr(ri)]);
+
+	if (!__is_valid_data_blkaddr(addr))
+		return 1;
+	if (!f2fs_is_valid_blkaddr(sbi, addr, DATA_GENERIC))
+		return -EFSCORRUPTED;
+	return 0;
+}
+
+static void __set_inode_rdev(struct inode *inode, struct f2fs_inode *ri)
+{
+	int extra_size = get_extra_isize(inode);
+
+	if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
+		if (old_valid_dev(inode->i_rdev)) {
+			ri->i_addr[extra_size] =
+				cpu_to_le32(old_encode_dev(inode->i_rdev));
+			ri->i_addr[extra_size + 1] = 0;
+		} else {
+			ri->i_addr[extra_size] = 0;
+			ri->i_addr[extra_size + 1] =
+				cpu_to_le32(new_encode_dev(inode->i_rdev));
+			ri->i_addr[extra_size + 2] = 0;
+		}
+	}
+}
+
+static void __recover_inline_status(struct inode *inode, struct page *ipage)
+{
+	void *inline_data = inline_data_addr(inode, ipage);
+	__le32 *start = inline_data;
+	__le32 *end = start + MAX_INLINE_DATA(inode) / sizeof(__le32);
+
+	while (start < end) {
+		if (*start++) {
+			f2fs_wait_on_page_writeback(ipage, NODE, true);
+
+			set_inode_flag(inode, FI_DATA_EXIST);
+			set_raw_inline(inode, F2FS_INODE(ipage));
+			set_page_dirty(ipage);
+			return;
+		}
+	}
+	return;
+}
+
+static bool f2fs_enable_inode_chksum(struct f2fs_sb_info *sbi, struct page *page)
+{
+	struct f2fs_inode *ri = &F2FS_NODE(page)->i;
+	int extra_isize = le32_to_cpu(ri->i_extra_isize);
+
+	if (!f2fs_sb_has_inode_chksum(sbi->sb))
+		return false;
+
+	if (!RAW_IS_INODE(F2FS_NODE(page)) || !(ri->i_inline & F2FS_EXTRA_ATTR))
+		return false;
+
+	if (!F2FS_FITS_IN_INODE(ri, extra_isize, i_inode_checksum))
+		return false;
+
+	return true;
+}
+
+static __u32 f2fs_inode_chksum(struct f2fs_sb_info *sbi, struct page *page)
+{
+	struct f2fs_node *node = F2FS_NODE(page);
+	struct f2fs_inode *ri = &node->i;
+	__le32 ino = node->footer.ino;
+	__le32 gen = ri->i_generation;
+	__u32 chksum, chksum_seed;
+	__u32 dummy_cs = 0;
+	unsigned int offset = offsetof(struct f2fs_inode, i_inode_checksum);
+	unsigned int cs_size = sizeof(dummy_cs);
+
+	chksum = f2fs_chksum(sbi, sbi->s_chksum_seed, (__u8 *)&ino,
+							sizeof(ino));
+	chksum_seed = f2fs_chksum(sbi, chksum, (__u8 *)&gen, sizeof(gen));
+
+	chksum = f2fs_chksum(sbi, chksum_seed, (__u8 *)ri, offset);
+	chksum = f2fs_chksum(sbi, chksum, (__u8 *)&dummy_cs, cs_size);
+	offset += cs_size;
+	chksum = f2fs_chksum(sbi, chksum, (__u8 *)ri + offset,
+						F2FS_BLKSIZE - offset);
+	return chksum;
+}
+
+bool f2fs_inode_chksum_verify(struct f2fs_sb_info *sbi, struct page *page)
+{
+	struct f2fs_inode *ri;
+	__u32 provided, calculated;
+
+	if (!f2fs_enable_inode_chksum(sbi, page) ||
+			PageDirty(page) || PageWriteback(page))
+		return true;
+
+	ri = &F2FS_NODE(page)->i;
+	provided = le32_to_cpu(ri->i_inode_checksum);
+	calculated = f2fs_inode_chksum(sbi, page);
+
+	if (provided != calculated)
+		f2fs_msg(sbi->sb, KERN_WARNING,
+			"checksum invalid, ino = %x, %x vs. %x",
+			ino_of_node(page), provided, calculated);
+
+	return provided == calculated;
+}
+
+void f2fs_inode_chksum_set(struct f2fs_sb_info *sbi, struct page *page)
+{
+	struct f2fs_inode *ri = &F2FS_NODE(page)->i;
+
+	if (!f2fs_enable_inode_chksum(sbi, page))
+		return;
+
+	ri->i_inode_checksum = cpu_to_le32(f2fs_inode_chksum(sbi, page));
+}
+
+static bool sanity_check_inode(struct inode *inode, struct page *node_page)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct f2fs_inode_info *fi = F2FS_I(inode);
+	unsigned long long iblocks;
+
+	iblocks = le64_to_cpu(F2FS_INODE(node_page)->i_blocks);
+	if (!iblocks) {
+		set_sbi_flag(sbi, SBI_NEED_FSCK);
+		f2fs_msg(sbi->sb, KERN_WARNING,
+			"%s: corrupted inode i_blocks i_ino=%lx iblocks=%llu, "
+			"run fsck to fix.",
+			__func__, inode->i_ino, iblocks);
+		return false;
+	}
+
+	if (ino_of_node(node_page) != nid_of_node(node_page)) {
+		set_sbi_flag(sbi, SBI_NEED_FSCK);
+		f2fs_msg(sbi->sb, KERN_WARNING,
+			"%s: corrupted inode footer i_ino=%lx, ino,nid: "
+			"[%u, %u] run fsck to fix.",
+			__func__, inode->i_ino,
+			ino_of_node(node_page), nid_of_node(node_page));
+		return false;
+	}
+
+	if (f2fs_has_extra_attr(inode) &&
+			!f2fs_sb_has_extra_attr(sbi->sb)) {
+		set_sbi_flag(sbi, SBI_NEED_FSCK);
+		f2fs_msg(sbi->sb, KERN_WARNING,
+			"%s: inode (ino=%lx) is with extra_attr, "
+			"but extra_attr feature is off",
+			__func__, inode->i_ino);
+		return false;
+	}
+
+	if (fi->i_extra_isize > F2FS_TOTAL_EXTRA_ATTR_SIZE ||
+			fi->i_extra_isize % sizeof(__le32)) {
+		set_sbi_flag(sbi, SBI_NEED_FSCK);
+		f2fs_msg(sbi->sb, KERN_WARNING,
+			"%s: inode (ino=%lx) has corrupted i_extra_isize: %d, "
+			"max: %zu",
+			__func__, inode->i_ino, fi->i_extra_isize,
+			F2FS_TOTAL_EXTRA_ATTR_SIZE);
+		return false;
+	}
+
+	if (F2FS_I(inode)->extent_tree) {
+		struct extent_info *ei = &F2FS_I(inode)->extent_tree->largest;
+
+		if (ei->len &&
+			(!f2fs_is_valid_blkaddr(sbi, ei->blk, DATA_GENERIC) ||
+			!f2fs_is_valid_blkaddr(sbi, ei->blk + ei->len - 1,
+							DATA_GENERIC))) {
+			set_sbi_flag(sbi, SBI_NEED_FSCK);
+			f2fs_msg(sbi->sb, KERN_WARNING,
+				"%s: inode (ino=%lx) extent info [%u, %u, %u] "
+				"is incorrect, run fsck to fix",
+				__func__, inode->i_ino,
+				ei->blk, ei->fofs, ei->len);
+			return false;
+		}
+	}
+	return true;
+}
+
+static int do_read_inode(struct inode *inode)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct f2fs_inode_info *fi = F2FS_I(inode);
+	struct page *node_page;
+	struct f2fs_inode *ri;
+	projid_t i_projid;
+	int err;
+
+	/* Check if ino is within scope */
+	if (check_nid_range(sbi, inode->i_ino))
+		return -EINVAL;
+
+	node_page = get_node_page(sbi, inode->i_ino);
+	if (IS_ERR(node_page))
+		return PTR_ERR(node_page);
+
+	ri = F2FS_INODE(node_page);
+
+	inode->i_mode = le16_to_cpu(ri->i_mode);
+	i_uid_write(inode, le32_to_cpu(ri->i_uid));
+	i_gid_write(inode, le32_to_cpu(ri->i_gid));
+	set_nlink(inode, le32_to_cpu(ri->i_links));
+	inode->i_size = le64_to_cpu(ri->i_size);
+	inode->i_blocks = SECTOR_FROM_BLOCK(le64_to_cpu(ri->i_blocks) - 1);
+
+	inode->i_atime.tv_sec = le64_to_cpu(ri->i_atime);
+	inode->i_ctime.tv_sec = le64_to_cpu(ri->i_ctime);
+	inode->i_mtime.tv_sec = le64_to_cpu(ri->i_mtime);
+	inode->i_atime.tv_nsec = le32_to_cpu(ri->i_atime_nsec);
+	inode->i_ctime.tv_nsec = le32_to_cpu(ri->i_ctime_nsec);
+	inode->i_mtime.tv_nsec = le32_to_cpu(ri->i_mtime_nsec);
+	inode->i_generation = le32_to_cpu(ri->i_generation);
+
+	fi->i_current_depth = le32_to_cpu(ri->i_current_depth);
+	fi->i_xattr_nid = le32_to_cpu(ri->i_xattr_nid);
+	fi->i_flags = le32_to_cpu(ri->i_flags);
+	fi->flags = 0;
+	fi->i_advise = ri->i_advise;
+	fi->i_pino = le32_to_cpu(ri->i_pino);
+	fi->i_dir_level = ri->i_dir_level;
+
+	if (f2fs_init_extent_tree(inode, &ri->i_ext))
+		set_page_dirty(node_page);
+
+	get_inline_info(inode, ri);
+
+	fi->i_extra_isize = f2fs_has_extra_attr(inode) ?
+					le16_to_cpu(ri->i_extra_isize) : 0;
+
+	if (f2fs_sb_has_flexible_inline_xattr(sbi->sb)) {
+		f2fs_bug_on(sbi, !f2fs_has_extra_attr(inode));
+		fi->i_inline_xattr_size = le16_to_cpu(ri->i_inline_xattr_size);
+	} else if (f2fs_has_inline_xattr(inode) ||
+				f2fs_has_inline_dentry(inode)) {
+		fi->i_inline_xattr_size = DEFAULT_INLINE_XATTR_ADDRS;
+	} else {
+
+		/*
+		 * Previous inline data or directory always reserved 200 bytes
+		 * in inode layout, even if inline_xattr is disabled. In order
+		 * to keep inline_dentry's structure for backward compatibility,
+		 * we get the space back only from inline_data.
+		 */
+		fi->i_inline_xattr_size = 0;
+	}
+
+	if (!sanity_check_inode(inode, node_page)) {
+		f2fs_put_page(node_page, 1);
+		return -EFSCORRUPTED;
+	}
+
+	/* check data exist */
+	if (f2fs_has_inline_data(inode) && !f2fs_exist_data(inode))
+		__recover_inline_status(inode, node_page);
+
+	/* get rdev by using inline_info */
+	__get_inode_rdev(inode, ri);
+
+	err = __written_first_block(sbi, ri);
+	if (err < 0) {
+		f2fs_put_page(node_page, 1);
+		return err;
+	}
+	if (!err)
+		set_inode_flag(inode, FI_FIRST_BLOCK_WRITTEN);
+
+	if (!need_inode_block_update(sbi, inode->i_ino))
+		fi->last_disk_size = inode->i_size;
+
+	if (fi->i_flags & FS_PROJINHERIT_FL)
+		set_inode_flag(inode, FI_PROJ_INHERIT);
+
+	if (f2fs_has_extra_attr(inode) && f2fs_sb_has_project_quota(sbi->sb) &&
+			F2FS_FITS_IN_INODE(ri, fi->i_extra_isize, i_projid))
+		i_projid = (projid_t)le32_to_cpu(ri->i_projid);
+	else
+		i_projid = F2FS_DEF_PROJID;
+	fi->i_projid = make_kprojid(&init_user_ns, i_projid);
+
+	if (f2fs_has_extra_attr(inode) && f2fs_sb_has_inode_crtime(sbi->sb) &&
+			F2FS_FITS_IN_INODE(ri, fi->i_extra_isize, i_crtime)) {
+		fi->i_crtime.tv_sec = le64_to_cpu(ri->i_crtime);
+		fi->i_crtime.tv_nsec = le32_to_cpu(ri->i_crtime_nsec);
+	}
+
+	F2FS_I(inode)->i_disk_time[0] = inode->i_atime;
+	F2FS_I(inode)->i_disk_time[1] = inode->i_ctime;
+	F2FS_I(inode)->i_disk_time[2] = inode->i_mtime;
+	F2FS_I(inode)->i_disk_time[3] = F2FS_I(inode)->i_crtime;
+	f2fs_put_page(node_page, 1);
+
+	stat_inc_inline_xattr(inode);
+	stat_inc_inline_inode(inode);
+	stat_inc_inline_dir(inode);
+
+	return 0;
+}
+
+struct inode *f2fs_iget(struct super_block *sb, unsigned long ino)
+{
+	struct f2fs_sb_info *sbi = F2FS_SB(sb);
+	struct inode *inode;
+	int ret = 0;
+
+	inode = iget_locked(sb, ino);
+	if (!inode)
+		return ERR_PTR(-ENOMEM);
+
+	if (!(inode->i_state & I_NEW)) {
+		trace_f2fs_iget(inode);
+		return inode;
+	}
+	if (ino == F2FS_NODE_INO(sbi) || ino == F2FS_META_INO(sbi))
+		goto make_now;
+
+	ret = do_read_inode(inode);
+	if (ret)
+		goto bad_inode;
+make_now:
+	if (ino == F2FS_NODE_INO(sbi)) {
+		inode->i_mapping->a_ops = &f2fs_node_aops;
+		mapping_set_gfp_mask(inode->i_mapping, GFP_F2FS_ZERO);
+	} else if (ino == F2FS_META_INO(sbi)) {
+		inode->i_mapping->a_ops = &f2fs_meta_aops;
+		mapping_set_gfp_mask(inode->i_mapping, GFP_F2FS_ZERO);
+	} else if (S_ISREG(inode->i_mode)) {
+		inode->i_op = &f2fs_file_inode_operations;
+		inode->i_fop = &f2fs_file_operations;
+		inode->i_mapping->a_ops = &f2fs_dblock_aops;
+	} else if (S_ISDIR(inode->i_mode)) {
+		inode->i_op = &f2fs_dir_inode_operations;
+		inode->i_fop = &f2fs_dir_operations;
+		inode->i_mapping->a_ops = &f2fs_dblock_aops;
+		inode_nohighmem(inode);
+	} else if (S_ISLNK(inode->i_mode)) {
+		if (f2fs_encrypted_inode(inode))
+			inode->i_op = &f2fs_encrypted_symlink_inode_operations;
+		else
+			inode->i_op = &f2fs_symlink_inode_operations;
+		inode_nohighmem(inode);
+		inode->i_mapping->a_ops = &f2fs_dblock_aops;
+	} else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
+			S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
+		inode->i_op = &f2fs_special_inode_operations;
+		init_special_inode(inode, inode->i_mode, inode->i_rdev);
+	} else {
+		ret = -EIO;
+		goto bad_inode;
+	}
+	f2fs_set_inode_flags(inode);
+	unlock_new_inode(inode);
+	trace_f2fs_iget(inode);
+	return inode;
+
+bad_inode:
+	f2fs_inode_synced(inode);
+	iget_failed(inode);
+	trace_f2fs_iget_exit(inode, ret);
+	return ERR_PTR(ret);
+}
+
+struct inode *f2fs_iget_retry(struct super_block *sb, unsigned long ino)
+{
+	struct inode *inode;
+retry:
+	inode = f2fs_iget(sb, ino);
+	if (IS_ERR(inode)) {
+		if (PTR_ERR(inode) == -ENOMEM) {
+			congestion_wait(BLK_RW_ASYNC, HZ/50);
+			goto retry;
+		}
+	}
+	return inode;
+}
+
+void update_inode(struct inode *inode, struct page *node_page)
+{
+	struct f2fs_inode *ri;
+	struct extent_tree *et = F2FS_I(inode)->extent_tree;
+
+	f2fs_wait_on_page_writeback(node_page, NODE, true);
+	set_page_dirty(node_page);
+
+	f2fs_inode_synced(inode);
+
+	ri = F2FS_INODE(node_page);
+
+	ri->i_mode = cpu_to_le16(inode->i_mode);
+	ri->i_advise = F2FS_I(inode)->i_advise;
+	ri->i_uid = cpu_to_le32(i_uid_read(inode));
+	ri->i_gid = cpu_to_le32(i_gid_read(inode));
+	ri->i_links = cpu_to_le32(inode->i_nlink);
+	ri->i_size = cpu_to_le64(i_size_read(inode));
+	ri->i_blocks = cpu_to_le64(SECTOR_TO_BLOCK(inode->i_blocks) + 1);
+
+	if (et) {
+		read_lock(&et->lock);
+		set_raw_extent(&et->largest, &ri->i_ext);
+		read_unlock(&et->lock);
+	} else {
+		memset(&ri->i_ext, 0, sizeof(ri->i_ext));
+	}
+	set_raw_inline(inode, ri);
+
+	ri->i_atime = cpu_to_le64(inode->i_atime.tv_sec);
+	ri->i_ctime = cpu_to_le64(inode->i_ctime.tv_sec);
+	ri->i_mtime = cpu_to_le64(inode->i_mtime.tv_sec);
+	ri->i_atime_nsec = cpu_to_le32(inode->i_atime.tv_nsec);
+	ri->i_ctime_nsec = cpu_to_le32(inode->i_ctime.tv_nsec);
+	ri->i_mtime_nsec = cpu_to_le32(inode->i_mtime.tv_nsec);
+	ri->i_current_depth = cpu_to_le32(F2FS_I(inode)->i_current_depth);
+	ri->i_xattr_nid = cpu_to_le32(F2FS_I(inode)->i_xattr_nid);
+	ri->i_flags = cpu_to_le32(F2FS_I(inode)->i_flags);
+	ri->i_pino = cpu_to_le32(F2FS_I(inode)->i_pino);
+	ri->i_generation = cpu_to_le32(inode->i_generation);
+	ri->i_dir_level = F2FS_I(inode)->i_dir_level;
+
+	if (f2fs_has_extra_attr(inode)) {
+		ri->i_extra_isize = cpu_to_le16(F2FS_I(inode)->i_extra_isize);
+
+		if (f2fs_sb_has_flexible_inline_xattr(F2FS_I_SB(inode)->sb))
+			ri->i_inline_xattr_size =
+				cpu_to_le16(F2FS_I(inode)->i_inline_xattr_size);
+
+		if (f2fs_sb_has_project_quota(F2FS_I_SB(inode)->sb) &&
+			F2FS_FITS_IN_INODE(ri, F2FS_I(inode)->i_extra_isize,
+								i_projid)) {
+			projid_t i_projid;
+
+			i_projid = from_kprojid(&init_user_ns,
+						F2FS_I(inode)->i_projid);
+			ri->i_projid = cpu_to_le32(i_projid);
+		}
+
+		if (f2fs_sb_has_inode_crtime(F2FS_I_SB(inode)->sb) &&
+			F2FS_FITS_IN_INODE(ri, F2FS_I(inode)->i_extra_isize,
+								i_crtime)) {
+			ri->i_crtime =
+				cpu_to_le64(F2FS_I(inode)->i_crtime.tv_sec);
+			ri->i_crtime_nsec =
+				cpu_to_le32(F2FS_I(inode)->i_crtime.tv_nsec);
+		}
+	}
+
+	__set_inode_rdev(inode, ri);
+
+	/* deleted inode */
+	if (inode->i_nlink == 0)
+		clear_inline_node(node_page);
+
+	F2FS_I(inode)->i_disk_time[0] = inode->i_atime;
+	F2FS_I(inode)->i_disk_time[1] = inode->i_ctime;
+	F2FS_I(inode)->i_disk_time[2] = inode->i_mtime;
+	F2FS_I(inode)->i_disk_time[3] = F2FS_I(inode)->i_crtime;
+}
+
+void update_inode_page(struct inode *inode)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct page *node_page;
+retry:
+	node_page = get_node_page(sbi, inode->i_ino);
+	if (IS_ERR(node_page)) {
+		int err = PTR_ERR(node_page);
+		if (err == -ENOMEM) {
+			cond_resched();
+			goto retry;
+		} else if (err != -ENOENT) {
+			f2fs_stop_checkpoint(sbi, false);
+		}
+		return;
+	}
+	update_inode(inode, node_page);
+	f2fs_put_page(node_page, 1);
+}
+
+int f2fs_write_inode(struct inode *inode, struct writeback_control *wbc)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+
+	if (inode->i_ino == F2FS_NODE_INO(sbi) ||
+			inode->i_ino == F2FS_META_INO(sbi))
+		return 0;
+
+	if (!is_inode_flag_set(inode, FI_DIRTY_INODE))
+		return 0;
+
+	/*
+	 * We need to balance fs here to prevent from producing dirty node pages
+	 * during the urgent cleaning time when runing out of free sections.
+	 */
+	update_inode_page(inode);
+	if (wbc && wbc->nr_to_write)
+		f2fs_balance_fs(sbi, true);
+	return 0;
+}
+
+/*
+ * Called at the last iput() if i_nlink is zero
+ */
+void f2fs_evict_inode(struct inode *inode)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	nid_t xnid = F2FS_I(inode)->i_xattr_nid;
+	int err = 0;
+
+	/* some remained atomic pages should discarded */
+	if (f2fs_is_atomic_file(inode))
+		drop_inmem_pages(inode);
+
+	trace_f2fs_evict_inode(inode);
+	truncate_inode_pages_final(&inode->i_data);
+
+	if (inode->i_ino == F2FS_NODE_INO(sbi) ||
+			inode->i_ino == F2FS_META_INO(sbi))
+		goto out_clear;
+
+	f2fs_bug_on(sbi, get_dirty_pages(inode));
+	remove_dirty_inode(inode);
+
+	f2fs_destroy_extent_tree(inode);
+
+	if (inode->i_nlink || is_bad_inode(inode))
+		goto no_delete;
+
+	dquot_initialize(inode);
+
+	remove_ino_entry(sbi, inode->i_ino, APPEND_INO);
+	remove_ino_entry(sbi, inode->i_ino, UPDATE_INO);
+	remove_ino_entry(sbi, inode->i_ino, FLUSH_INO);
+
+	sb_start_intwrite(inode->i_sb);
+	set_inode_flag(inode, FI_NO_ALLOC);
+	i_size_write(inode, 0);
+retry:
+	if (F2FS_HAS_BLOCKS(inode))
+		err = f2fs_truncate(inode);
+
+#ifdef CONFIG_F2FS_FAULT_INJECTION
+	if (time_to_inject(sbi, FAULT_EVICT_INODE)) {
+		f2fs_show_injection_info(FAULT_EVICT_INODE);
+		err = -EIO;
+	}
+#endif
+	if (!err) {
+		f2fs_lock_op(sbi);
+		err = remove_inode_page(inode);
+		f2fs_unlock_op(sbi);
+		if (err == -ENOENT)
+			err = 0;
+	}
+
+	/* give more chances, if ENOMEM case */
+	if (err == -ENOMEM) {
+		err = 0;
+		goto retry;
+	}
+
+	if (err)
+		update_inode_page(inode);
+	dquot_free_inode(inode);
+	sb_end_intwrite(inode->i_sb);
+no_delete:
+	dquot_drop(inode);
+
+	stat_dec_inline_xattr(inode);
+	stat_dec_inline_dir(inode);
+	stat_dec_inline_inode(inode);
+
+	if (likely(!is_set_ckpt_flags(sbi, CP_ERROR_FLAG)))
+		f2fs_bug_on(sbi, is_inode_flag_set(inode, FI_DIRTY_INODE));
+	else
+		f2fs_inode_synced(inode);
+
+	/* ino == 0, if f2fs_new_inode() was failed t*/
+	if (inode->i_ino)
+		invalidate_mapping_pages(NODE_MAPPING(sbi), inode->i_ino,
+							inode->i_ino);
+	if (xnid)
+		invalidate_mapping_pages(NODE_MAPPING(sbi), xnid, xnid);
+	if (inode->i_nlink) {
+		if (is_inode_flag_set(inode, FI_APPEND_WRITE))
+			add_ino_entry(sbi, inode->i_ino, APPEND_INO);
+		if (is_inode_flag_set(inode, FI_UPDATE_WRITE))
+			add_ino_entry(sbi, inode->i_ino, UPDATE_INO);
+	}
+	if (is_inode_flag_set(inode, FI_FREE_NID)) {
+		alloc_nid_failed(sbi, inode->i_ino);
+		clear_inode_flag(inode, FI_FREE_NID);
+	} else {
+		/*
+		 * If xattr nid is corrupted, we can reach out error condition,
+		 * err & !exist_written_data(sbi, inode->i_ino, ORPHAN_INO)).
+		 * In that case, check_nid_range() is enough to give a clue.
+		 */
+	}
+out_clear:
+	fscrypt_put_encryption_info(inode);
+	clear_inode(inode);
+}
+
+/* caller should call f2fs_lock_op() */
+void handle_failed_inode(struct inode *inode)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct node_info ni;
+
+	/*
+	 * clear nlink of inode in order to release resource of inode
+	 * immediately.
+	 */
+	clear_nlink(inode);
+
+	/*
+	 * we must call this to avoid inode being remained as dirty, resulting
+	 * in a panic when flushing dirty inodes in gdirty_list.
+	 */
+	update_inode_page(inode);
+	f2fs_inode_synced(inode);
+
+	/* don't make bad inode, since it becomes a regular file. */
+	unlock_new_inode(inode);
+
+	/*
+	 * Note: we should add inode to orphan list before f2fs_unlock_op()
+	 * so we can prevent losing this orphan when encoutering checkpoint
+	 * and following suddenly power-off.
+	 */
+	get_node_info(sbi, inode->i_ino, &ni);
+
+	if (ni.blk_addr != NULL_ADDR) {
+		int err = acquire_orphan_inode(sbi);
+		if (err) {
+			set_sbi_flag(sbi, SBI_NEED_FSCK);
+			f2fs_msg(sbi->sb, KERN_WARNING,
+				"Too many orphan inodes, run fsck to fix.");
+		} else {
+			add_orphan_inode(inode);
+		}
+		alloc_nid_done(sbi, inode->i_ino);
+	} else {
+		set_inode_flag(inode, FI_FREE_NID);
+	}
+
+	f2fs_unlock_op(sbi);
+
+	/* iput will drop the inode object */
+	iput(inode);
+}
diff --git a/src/kernel/linux/v4.14/fs/f2fs/namei.c b/src/kernel/linux/v4.14/fs/f2fs/namei.c
new file mode 100644
index 0000000..fd0820f
--- /dev/null
+++ b/src/kernel/linux/v4.14/fs/f2fs/namei.c
@@ -0,0 +1,1249 @@
+/*
+ * fs/f2fs/namei.c
+ *
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ *             http://www.samsung.com/
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/fs.h>
+#include <linux/f2fs_fs.h>
+#include <linux/pagemap.h>
+#include <linux/sched.h>
+#include <linux/ctype.h>
+#include <linux/dcache.h>
+#include <linux/namei.h>
+#include <linux/quotaops.h>
+
+#include "f2fs.h"
+#include "node.h"
+#include "xattr.h"
+#include "acl.h"
+#include <trace/events/f2fs.h>
+
+static struct inode *f2fs_new_inode(struct inode *dir, umode_t mode)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
+	nid_t ino;
+	struct inode *inode;
+	bool nid_free = false;
+	int xattr_size = 0;
+	int err;
+
+	inode = new_inode(dir->i_sb);
+	if (!inode)
+		return ERR_PTR(-ENOMEM);
+
+	f2fs_lock_op(sbi);
+	if (!alloc_nid(sbi, &ino)) {
+		f2fs_unlock_op(sbi);
+		err = -ENOSPC;
+		goto fail;
+	}
+	f2fs_unlock_op(sbi);
+
+	nid_free = true;
+
+	inode_init_owner(inode, dir, mode);
+
+	inode->i_ino = ino;
+	inode->i_blocks = 0;
+	inode->i_mtime = inode->i_atime = inode->i_ctime =
+			F2FS_I(inode)->i_crtime = current_time(inode);
+	inode->i_generation = sbi->s_next_generation++;
+
+	err = insert_inode_locked(inode);
+	if (err) {
+		err = -EINVAL;
+		goto fail;
+	}
+
+	if (f2fs_sb_has_project_quota(sbi->sb) &&
+		(F2FS_I(dir)->i_flags & FS_PROJINHERIT_FL))
+		F2FS_I(inode)->i_projid = F2FS_I(dir)->i_projid;
+	else
+		F2FS_I(inode)->i_projid = make_kprojid(&init_user_ns,
+							F2FS_DEF_PROJID);
+
+	err = dquot_initialize(inode);
+	if (err)
+		goto fail_drop;
+
+	err = dquot_alloc_inode(inode);
+	if (err)
+		goto fail_drop;
+
+	set_inode_flag(inode, FI_NEW_INODE);
+
+	/* If the directory encrypted, then we should encrypt the inode. */
+	if ((f2fs_encrypted_inode(dir) || DUMMY_ENCRYPTION_ENABLED(sbi)) &&
+				f2fs_may_encrypt(inode))
+		f2fs_set_encrypted_inode(inode);
+
+	if (f2fs_sb_has_extra_attr(sbi->sb)) {
+		set_inode_flag(inode, FI_EXTRA_ATTR);
+		F2FS_I(inode)->i_extra_isize = F2FS_TOTAL_EXTRA_ATTR_SIZE;
+	}
+
+	if (test_opt(sbi, INLINE_XATTR))
+		set_inode_flag(inode, FI_INLINE_XATTR);
+
+	if (test_opt(sbi, INLINE_DATA) && f2fs_may_inline_data(inode))
+		set_inode_flag(inode, FI_INLINE_DATA);
+	if (f2fs_may_inline_dentry(inode))
+		set_inode_flag(inode, FI_INLINE_DENTRY);
+
+	if (f2fs_sb_has_flexible_inline_xattr(sbi->sb)) {
+		f2fs_bug_on(sbi, !f2fs_has_extra_attr(inode));
+		if (f2fs_has_inline_xattr(inode))
+			xattr_size = F2FS_OPTION(sbi).inline_xattr_size;
+		/* Otherwise, will be 0 */
+	} else if (f2fs_has_inline_xattr(inode) ||
+				f2fs_has_inline_dentry(inode)) {
+		xattr_size = DEFAULT_INLINE_XATTR_ADDRS;
+	}
+	F2FS_I(inode)->i_inline_xattr_size = xattr_size;
+
+	f2fs_init_extent_tree(inode, NULL);
+
+	stat_inc_inline_xattr(inode);
+	stat_inc_inline_inode(inode);
+	stat_inc_inline_dir(inode);
+
+	F2FS_I(inode)->i_flags =
+		f2fs_mask_flags(mode, F2FS_I(dir)->i_flags & F2FS_FL_INHERITED);
+
+	if (S_ISDIR(inode->i_mode))
+		F2FS_I(inode)->i_flags |= FS_INDEX_FL;
+
+	if (F2FS_I(inode)->i_flags & FS_PROJINHERIT_FL)
+		set_inode_flag(inode, FI_PROJ_INHERIT);
+
+	trace_f2fs_new_inode(inode, 0);
+	return inode;
+
+fail:
+	trace_f2fs_new_inode(inode, err);
+	make_bad_inode(inode);
+	if (nid_free)
+		set_inode_flag(inode, FI_FREE_NID);
+	iput(inode);
+	return ERR_PTR(err);
+fail_drop:
+	trace_f2fs_new_inode(inode, err);
+	dquot_drop(inode);
+	inode->i_flags |= S_NOQUOTA;
+	if (nid_free)
+		set_inode_flag(inode, FI_FREE_NID);
+	clear_nlink(inode);
+	unlock_new_inode(inode);
+	iput(inode);
+	return ERR_PTR(err);
+}
+
+static int is_extension_exist(const unsigned char *s, const char *sub)
+{
+	size_t slen = strlen(s);
+	size_t sublen = strlen(sub);
+	int i;
+
+	/*
+	 * filename format of multimedia file should be defined as:
+	 * "filename + '.' + extension + (optional: '.' + temp extension)".
+	 */
+	if (slen < sublen + 2)
+		return 0;
+
+	for (i = 1; i < slen - sublen; i++) {
+		if (s[i] != '.')
+			continue;
+		if (!strncasecmp(s + i + 1, sub, sublen))
+			return 1;
+	}
+
+	return 0;
+}
+
+/*
+ * Set multimedia files as cold files for hot/cold data separation
+ */
+static inline void set_file_temperature(struct f2fs_sb_info *sbi, struct inode *inode,
+		const unsigned char *name)
+{
+	__u8 (*extlist)[F2FS_EXTENSION_LEN] = sbi->raw_super->extension_list;
+	int i, cold_count, hot_count;
+
+	down_read(&sbi->sb_lock);
+
+	cold_count = le32_to_cpu(sbi->raw_super->extension_count);
+	hot_count = sbi->raw_super->hot_ext_count;
+
+	for (i = 0; i < cold_count + hot_count; i++) {
+		if (!is_extension_exist(name, extlist[i]))
+			continue;
+		if (i < cold_count)
+			file_set_cold(inode);
+		else
+			file_set_hot(inode);
+		break;
+	}
+
+	up_read(&sbi->sb_lock);
+}
+
+int update_extension_list(struct f2fs_sb_info *sbi, const char *name,
+							bool hot, bool set)
+{
+	__u8 (*extlist)[F2FS_EXTENSION_LEN] = sbi->raw_super->extension_list;
+	int cold_count = le32_to_cpu(sbi->raw_super->extension_count);
+	int hot_count = sbi->raw_super->hot_ext_count;
+	int total_count = cold_count + hot_count;
+	int start, count;
+	int i;
+
+	if (set) {
+		if (total_count == F2FS_MAX_EXTENSION)
+			return -EINVAL;
+	} else {
+		if (!hot && !cold_count)
+			return -EINVAL;
+		if (hot && !hot_count)
+			return -EINVAL;
+	}
+
+	if (hot) {
+		start = cold_count;
+		count = total_count;
+	} else {
+		start = 0;
+		count = cold_count;
+	}
+
+	for (i = start; i < count; i++) {
+		if (strcmp(name, extlist[i]))
+			continue;
+
+		if (set)
+			return -EINVAL;
+
+		memcpy(extlist[i], extlist[i + 1],
+				F2FS_EXTENSION_LEN * (total_count - i - 1));
+		memset(extlist[total_count - 1], 0, F2FS_EXTENSION_LEN);
+		if (hot)
+			sbi->raw_super->hot_ext_count = hot_count - 1;
+		else
+			sbi->raw_super->extension_count =
+						cpu_to_le32(cold_count - 1);
+		return 0;
+	}
+
+	if (!set)
+		return -EINVAL;
+
+	if (hot) {
+		strncpy(extlist[count], name, strlen(name));
+		sbi->raw_super->hot_ext_count = hot_count + 1;
+	} else {
+		char buf[F2FS_MAX_EXTENSION][F2FS_EXTENSION_LEN];
+
+		memcpy(buf, &extlist[cold_count],
+				F2FS_EXTENSION_LEN * hot_count);
+		memset(extlist[cold_count], 0, F2FS_EXTENSION_LEN);
+		strncpy(extlist[cold_count], name, strlen(name));
+		memcpy(&extlist[cold_count + 1], buf,
+				F2FS_EXTENSION_LEN * hot_count);
+		sbi->raw_super->extension_count = cpu_to_le32(cold_count + 1);
+	}
+	return 0;
+}
+
+static int f2fs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
+						bool excl)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
+	struct inode *inode;
+	nid_t ino = 0;
+	int err;
+
+	if (unlikely(f2fs_cp_error(sbi)))
+		return -EIO;
+
+	err = dquot_initialize(dir);
+	if (err)
+		return err;
+
+	inode = f2fs_new_inode(dir, mode);
+	if (IS_ERR(inode))
+		return PTR_ERR(inode);
+
+	if (!test_opt(sbi, DISABLE_EXT_IDENTIFY))
+		set_file_temperature(sbi, inode, dentry->d_name.name);
+
+	inode->i_op = &f2fs_file_inode_operations;
+	inode->i_fop = &f2fs_file_operations;
+	inode->i_mapping->a_ops = &f2fs_dblock_aops;
+	ino = inode->i_ino;
+
+	f2fs_lock_op(sbi);
+	err = f2fs_add_link(dentry, inode);
+	if (err)
+		goto out;
+	f2fs_unlock_op(sbi);
+
+	alloc_nid_done(sbi, ino);
+
+	d_instantiate_new(dentry, inode);
+
+	if (IS_DIRSYNC(dir))
+		f2fs_sync_fs(sbi->sb, 1);
+
+	f2fs_balance_fs(sbi, true);
+	return 0;
+out:
+	handle_failed_inode(inode);
+	return err;
+}
+
+static int f2fs_link(struct dentry *old_dentry, struct inode *dir,
+		struct dentry *dentry)
+{
+	struct inode *inode = d_inode(old_dentry);
+	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
+	int err;
+
+	if (unlikely(f2fs_cp_error(sbi)))
+		return -EIO;
+
+	err = fscrypt_prepare_link(old_dentry, dir, dentry);
+	if (err)
+		return err;
+
+	if (is_inode_flag_set(dir, FI_PROJ_INHERIT) &&
+			(!projid_eq(F2FS_I(dir)->i_projid,
+			F2FS_I(old_dentry->d_inode)->i_projid)))
+		return -EXDEV;
+
+	err = dquot_initialize(dir);
+	if (err)
+		return err;
+
+	f2fs_balance_fs(sbi, true);
+
+	inode->i_ctime = current_time(inode);
+	ihold(inode);
+
+	set_inode_flag(inode, FI_INC_LINK);
+	f2fs_lock_op(sbi);
+	err = f2fs_add_link(dentry, inode);
+	if (err)
+		goto out;
+	f2fs_unlock_op(sbi);
+
+	d_instantiate(dentry, inode);
+
+	if (IS_DIRSYNC(dir))
+		f2fs_sync_fs(sbi->sb, 1);
+	return 0;
+out:
+	clear_inode_flag(inode, FI_INC_LINK);
+	iput(inode);
+	f2fs_unlock_op(sbi);
+	return err;
+}
+
+struct dentry *f2fs_get_parent(struct dentry *child)
+{
+	struct qstr dotdot = QSTR_INIT("..", 2);
+	struct page *page;
+	unsigned long ino = f2fs_inode_by_name(d_inode(child), &dotdot, &page);
+	if (!ino) {
+		if (IS_ERR(page))
+			return ERR_CAST(page);
+		return ERR_PTR(-ENOENT);
+	}
+	return d_obtain_alias(f2fs_iget(child->d_sb, ino));
+}
+
+static int __recover_dot_dentries(struct inode *dir, nid_t pino)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
+	struct qstr dot = QSTR_INIT(".", 1);
+	struct qstr dotdot = QSTR_INIT("..", 2);
+	struct f2fs_dir_entry *de;
+	struct page *page;
+	int err = 0;
+
+	if (f2fs_readonly(sbi->sb)) {
+		f2fs_msg(sbi->sb, KERN_INFO,
+			"skip recovering inline_dots inode (ino:%lu, pino:%u) "
+			"in readonly mountpoint", dir->i_ino, pino);
+		return 0;
+	}
+
+	err = dquot_initialize(dir);
+	if (err)
+		return err;
+
+	f2fs_balance_fs(sbi, true);
+
+	f2fs_lock_op(sbi);
+
+	de = f2fs_find_entry(dir, &dot, &page);
+	if (de) {
+		f2fs_put_page(page, 0);
+	} else if (IS_ERR(page)) {
+		err = PTR_ERR(page);
+		goto out;
+	} else {
+		err = __f2fs_add_link(dir, &dot, NULL, dir->i_ino, S_IFDIR);
+		if (err)
+			goto out;
+	}
+
+	de = f2fs_find_entry(dir, &dotdot, &page);
+	if (de)
+		f2fs_put_page(page, 0);
+	else if (IS_ERR(page))
+		err = PTR_ERR(page);
+	else
+		err = __f2fs_add_link(dir, &dotdot, NULL, pino, S_IFDIR);
+out:
+	if (!err)
+		clear_inode_flag(dir, FI_INLINE_DOTS);
+
+	f2fs_unlock_op(sbi);
+	return err;
+}
+
+static struct dentry *f2fs_lookup(struct inode *dir, struct dentry *dentry,
+		unsigned int flags)
+{
+	struct inode *inode = NULL;
+	struct f2fs_dir_entry *de;
+	struct page *page;
+	struct dentry *new;
+	nid_t ino = -1;
+	int err = 0;
+	unsigned int root_ino = F2FS_ROOT_INO(F2FS_I_SB(dir));
+
+	trace_f2fs_lookup_start(dir, dentry, flags);
+
+	err = fscrypt_prepare_lookup(dir, dentry, flags);
+	if (err)
+		goto out;
+
+	if (dentry->d_name.len > F2FS_NAME_LEN) {
+		err = -ENAMETOOLONG;
+		goto out;
+	}
+
+	de = f2fs_find_entry(dir, &dentry->d_name, &page);
+	if (!de) {
+		if (IS_ERR(page)) {
+			err = PTR_ERR(page);
+			goto out;
+		}
+		goto out_splice;
+	}
+
+	ino = le32_to_cpu(de->ino);
+	f2fs_put_page(page, 0);
+
+	inode = f2fs_iget(dir->i_sb, ino);
+	if (IS_ERR(inode)) {
+		err = PTR_ERR(inode);
+		goto out;
+	}
+
+	if ((dir->i_ino == root_ino) && f2fs_has_inline_dots(dir)) {
+		err = __recover_dot_dentries(dir, root_ino);
+		if (err)
+			goto out_iput;
+	}
+
+	if (f2fs_has_inline_dots(inode)) {
+		err = __recover_dot_dentries(inode, dir->i_ino);
+		if (err)
+			goto out_iput;
+	}
+	if (f2fs_encrypted_inode(dir) &&
+	    (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)) &&
+	    !fscrypt_has_permitted_context(dir, inode)) {
+		f2fs_msg(inode->i_sb, KERN_WARNING,
+			 "Inconsistent encryption contexts: %lu/%lu",
+			 dir->i_ino, inode->i_ino);
+		err = -EPERM;
+		goto out_iput;
+	}
+out_splice:
+	new = d_splice_alias(inode, dentry);
+	if (IS_ERR(new))
+		err = PTR_ERR(new);
+	trace_f2fs_lookup_end(dir, dentry, ino, err);
+	return new;
+out_iput:
+	iput(inode);
+out:
+	trace_f2fs_lookup_end(dir, dentry, ino, err);
+	return ERR_PTR(err);
+}
+
+static int f2fs_unlink(struct inode *dir, struct dentry *dentry)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
+	struct inode *inode = d_inode(dentry);
+	struct f2fs_dir_entry *de;
+	struct page *page;
+	int err = -ENOENT;
+
+	trace_f2fs_unlink_enter(dir, dentry);
+
+	if (unlikely(f2fs_cp_error(sbi)))
+		return -EIO;
+
+	err = dquot_initialize(dir);
+	if (err)
+		return err;
+	err = dquot_initialize(inode);
+	if (err)
+		return err;
+
+	de = f2fs_find_entry(dir, &dentry->d_name, &page);
+	if (!de) {
+		if (IS_ERR(page))
+			err = PTR_ERR(page);
+		goto fail;
+	}
+
+	f2fs_balance_fs(sbi, true);
+
+	f2fs_lock_op(sbi);
+	err = acquire_orphan_inode(sbi);
+	if (err) {
+		f2fs_unlock_op(sbi);
+		f2fs_put_page(page, 0);
+		goto fail;
+	}
+	f2fs_delete_entry(de, page, dir, inode);
+	f2fs_unlock_op(sbi);
+
+	if (IS_DIRSYNC(dir))
+		f2fs_sync_fs(sbi->sb, 1);
+fail:
+	trace_f2fs_unlink_exit(inode, err);
+	return err;
+}
+
+static const char *f2fs_get_link(struct dentry *dentry,
+				 struct inode *inode,
+				 struct delayed_call *done)
+{
+	const char *link = page_get_link(dentry, inode, done);
+	if (!IS_ERR(link) && !*link) {
+		/* this is broken symlink case */
+		do_delayed_call(done);
+		clear_delayed_call(done);
+		link = ERR_PTR(-ENOENT);
+	}
+	return link;
+}
+
+static int f2fs_symlink(struct inode *dir, struct dentry *dentry,
+					const char *symname)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
+	struct inode *inode;
+	size_t len = strlen(symname);
+	struct fscrypt_str disk_link;
+	int err;
+
+	if (unlikely(f2fs_cp_error(sbi)))
+		return -EIO;
+
+	err = fscrypt_prepare_symlink(dir, symname, len, dir->i_sb->s_blocksize,
+				      &disk_link);
+	if (err)
+		return err;
+
+	err = dquot_initialize(dir);
+	if (err)
+		return err;
+
+	inode = f2fs_new_inode(dir, S_IFLNK | S_IRWXUGO);
+	if (IS_ERR(inode))
+		return PTR_ERR(inode);
+
+	if (IS_ENCRYPTED(inode))
+		inode->i_op = &f2fs_encrypted_symlink_inode_operations;
+	else
+		inode->i_op = &f2fs_symlink_inode_operations;
+	inode_nohighmem(inode);
+	inode->i_mapping->a_ops = &f2fs_dblock_aops;
+
+	f2fs_lock_op(sbi);
+	err = f2fs_add_link(dentry, inode);
+	if (err)
+		goto out_handle_failed_inode;
+	f2fs_unlock_op(sbi);
+	alloc_nid_done(sbi, inode->i_ino);
+
+	err = fscrypt_encrypt_symlink(inode, symname, len, &disk_link);
+	if (err)
+		goto err_out;
+
+	err = page_symlink(inode, disk_link.name, disk_link.len);
+
+err_out:
+	d_instantiate_new(dentry, inode);
+
+	/*
+	 * Let's flush symlink data in order to avoid broken symlink as much as
+	 * possible. Nevertheless, fsyncing is the best way, but there is no
+	 * way to get a file descriptor in order to flush that.
+	 *
+	 * Note that, it needs to do dir->fsync to make this recoverable.
+	 * If the symlink path is stored into inline_data, there is no
+	 * performance regression.
+	 */
+	if (!err) {
+		filemap_write_and_wait_range(inode->i_mapping, 0,
+							disk_link.len - 1);
+
+		if (IS_DIRSYNC(dir))
+			f2fs_sync_fs(sbi->sb, 1);
+	} else {
+		f2fs_unlink(dir, dentry);
+	}
+
+	f2fs_balance_fs(sbi, true);
+	goto out_free_encrypted_link;
+
+out_handle_failed_inode:
+	handle_failed_inode(inode);
+out_free_encrypted_link:
+	if (disk_link.name != (unsigned char *)symname)
+		kfree(disk_link.name);
+	return err;
+}
+
+static int f2fs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
+	struct inode *inode;
+	int err;
+
+	if (unlikely(f2fs_cp_error(sbi)))
+		return -EIO;
+
+	err = dquot_initialize(dir);
+	if (err)
+		return err;
+
+	inode = f2fs_new_inode(dir, S_IFDIR | mode);
+	if (IS_ERR(inode))
+		return PTR_ERR(inode);
+
+	inode->i_op = &f2fs_dir_inode_operations;
+	inode->i_fop = &f2fs_dir_operations;
+	inode->i_mapping->a_ops = &f2fs_dblock_aops;
+	inode_nohighmem(inode);
+
+	set_inode_flag(inode, FI_INC_LINK);
+	f2fs_lock_op(sbi);
+	err = f2fs_add_link(dentry, inode);
+	if (err)
+		goto out_fail;
+	f2fs_unlock_op(sbi);
+
+	alloc_nid_done(sbi, inode->i_ino);
+
+	d_instantiate_new(dentry, inode);
+
+	if (IS_DIRSYNC(dir))
+		f2fs_sync_fs(sbi->sb, 1);
+
+	f2fs_balance_fs(sbi, true);
+	return 0;
+
+out_fail:
+	clear_inode_flag(inode, FI_INC_LINK);
+	handle_failed_inode(inode);
+	return err;
+}
+
+static int f2fs_rmdir(struct inode *dir, struct dentry *dentry)
+{
+	struct inode *inode = d_inode(dentry);
+	if (f2fs_empty_dir(inode))
+		return f2fs_unlink(dir, dentry);
+	return -ENOTEMPTY;
+}
+
+static int f2fs_mknod(struct inode *dir, struct dentry *dentry,
+				umode_t mode, dev_t rdev)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
+	struct inode *inode;
+	int err = 0;
+
+	if (unlikely(f2fs_cp_error(sbi)))
+		return -EIO;
+
+	err = dquot_initialize(dir);
+	if (err)
+		return err;
+
+	inode = f2fs_new_inode(dir, mode);
+	if (IS_ERR(inode))
+		return PTR_ERR(inode);
+
+	init_special_inode(inode, inode->i_mode, rdev);
+	inode->i_op = &f2fs_special_inode_operations;
+
+	f2fs_lock_op(sbi);
+	err = f2fs_add_link(dentry, inode);
+	if (err)
+		goto out;
+	f2fs_unlock_op(sbi);
+
+	alloc_nid_done(sbi, inode->i_ino);
+
+	d_instantiate_new(dentry, inode);
+
+	if (IS_DIRSYNC(dir))
+		f2fs_sync_fs(sbi->sb, 1);
+
+	f2fs_balance_fs(sbi, true);
+	return 0;
+out:
+	handle_failed_inode(inode);
+	return err;
+}
+
+static int __f2fs_tmpfile(struct inode *dir, struct dentry *dentry,
+					umode_t mode, struct inode **whiteout)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
+	struct inode *inode;
+	int err;
+
+	err = dquot_initialize(dir);
+	if (err)
+		return err;
+
+	inode = f2fs_new_inode(dir, mode);
+	if (IS_ERR(inode))
+		return PTR_ERR(inode);
+
+	if (whiteout) {
+		init_special_inode(inode, inode->i_mode, WHITEOUT_DEV);
+		inode->i_op = &f2fs_special_inode_operations;
+	} else {
+		inode->i_op = &f2fs_file_inode_operations;
+		inode->i_fop = &f2fs_file_operations;
+		inode->i_mapping->a_ops = &f2fs_dblock_aops;
+	}
+
+	f2fs_lock_op(sbi);
+	err = acquire_orphan_inode(sbi);
+	if (err)
+		goto out;
+
+	err = f2fs_do_tmpfile(inode, dir);
+	if (err)
+		goto release_out;
+
+	/*
+	 * add this non-linked tmpfile to orphan list, in this way we could
+	 * remove all unused data of tmpfile after abnormal power-off.
+	 */
+	add_orphan_inode(inode);
+	alloc_nid_done(sbi, inode->i_ino);
+
+	if (whiteout) {
+		f2fs_i_links_write(inode, false);
+		*whiteout = inode;
+	} else {
+		d_tmpfile(dentry, inode);
+	}
+	/* link_count was changed by d_tmpfile as well. */
+	f2fs_unlock_op(sbi);
+	unlock_new_inode(inode);
+
+	f2fs_balance_fs(sbi, true);
+	return 0;
+
+release_out:
+	release_orphan_inode(sbi);
+out:
+	handle_failed_inode(inode);
+	return err;
+}
+
+static int f2fs_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
+
+	if (unlikely(f2fs_cp_error(sbi)))
+		return -EIO;
+
+	if (f2fs_encrypted_inode(dir) || DUMMY_ENCRYPTION_ENABLED(sbi)) {
+		int err = fscrypt_get_encryption_info(dir);
+		if (err)
+			return err;
+	}
+
+	return __f2fs_tmpfile(dir, dentry, mode, NULL);
+}
+
+static int f2fs_create_whiteout(struct inode *dir, struct inode **whiteout)
+{
+	if (unlikely(f2fs_cp_error(F2FS_I_SB(dir))))
+		return -EIO;
+
+	return __f2fs_tmpfile(dir, NULL, S_IFCHR | WHITEOUT_MODE, whiteout);
+}
+
+static int f2fs_rename(struct inode *old_dir, struct dentry *old_dentry,
+			struct inode *new_dir, struct dentry *new_dentry,
+			unsigned int flags)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(old_dir);
+	struct inode *old_inode = d_inode(old_dentry);
+	struct inode *new_inode = d_inode(new_dentry);
+	struct inode *whiteout = NULL;
+	struct page *old_dir_page;
+	struct page *old_page, *new_page = NULL;
+	struct f2fs_dir_entry *old_dir_entry = NULL;
+	struct f2fs_dir_entry *old_entry;
+	struct f2fs_dir_entry *new_entry;
+	bool is_old_inline = f2fs_has_inline_dentry(old_dir);
+	int err = -ENOENT;
+
+	if (unlikely(f2fs_cp_error(sbi)))
+		return -EIO;
+
+	if (is_inode_flag_set(new_dir, FI_PROJ_INHERIT) &&
+			(!projid_eq(F2FS_I(new_dir)->i_projid,
+			F2FS_I(old_dentry->d_inode)->i_projid)))
+		return -EXDEV;
+
+	err = dquot_initialize(old_dir);
+	if (err)
+		goto out;
+
+	err = dquot_initialize(new_dir);
+	if (err)
+		goto out;
+
+	if (new_inode) {
+		err = dquot_initialize(new_inode);
+		if (err)
+			goto out;
+	}
+
+	old_entry = f2fs_find_entry(old_dir, &old_dentry->d_name, &old_page);
+	if (!old_entry) {
+		if (IS_ERR(old_page))
+			err = PTR_ERR(old_page);
+		goto out;
+	}
+
+	if (S_ISDIR(old_inode->i_mode)) {
+		old_dir_entry = f2fs_parent_dir(old_inode, &old_dir_page);
+		if (!old_dir_entry) {
+			if (IS_ERR(old_dir_page))
+				err = PTR_ERR(old_dir_page);
+			goto out_old;
+		}
+	}
+
+	if (flags & RENAME_WHITEOUT) {
+		err = f2fs_create_whiteout(old_dir, &whiteout);
+		if (err)
+			goto out_dir;
+	}
+
+	if (new_inode) {
+
+		err = -ENOTEMPTY;
+		if (old_dir_entry && !f2fs_empty_dir(new_inode))
+			goto out_whiteout;
+
+		err = -ENOENT;
+		new_entry = f2fs_find_entry(new_dir, &new_dentry->d_name,
+						&new_page);
+		if (!new_entry) {
+			if (IS_ERR(new_page))
+				err = PTR_ERR(new_page);
+			goto out_whiteout;
+		}
+
+		f2fs_balance_fs(sbi, true);
+
+		f2fs_lock_op(sbi);
+
+		err = acquire_orphan_inode(sbi);
+		if (err)
+			goto put_out_dir;
+
+		f2fs_set_link(new_dir, new_entry, new_page, old_inode);
+
+		new_inode->i_ctime = current_time(new_inode);
+		down_write(&F2FS_I(new_inode)->i_sem);
+		if (old_dir_entry)
+			f2fs_i_links_write(new_inode, false);
+		f2fs_i_links_write(new_inode, false);
+		up_write(&F2FS_I(new_inode)->i_sem);
+
+		if (!new_inode->i_nlink)
+			add_orphan_inode(new_inode);
+		else
+			release_orphan_inode(sbi);
+	} else {
+		f2fs_balance_fs(sbi, true);
+
+		f2fs_lock_op(sbi);
+
+		err = f2fs_add_link(new_dentry, old_inode);
+		if (err) {
+			f2fs_unlock_op(sbi);
+			goto out_whiteout;
+		}
+
+		if (old_dir_entry)
+			f2fs_i_links_write(new_dir, true);
+
+		/*
+		 * old entry and new entry can locate in the same inline
+		 * dentry in inode, when attaching new entry in inline dentry,
+		 * it could force inline dentry conversion, after that,
+		 * old_entry and old_page will point to wrong address, in
+		 * order to avoid this, let's do the check and update here.
+		 */
+		if (is_old_inline && !f2fs_has_inline_dentry(old_dir)) {
+			f2fs_put_page(old_page, 0);
+			old_page = NULL;
+
+			old_entry = f2fs_find_entry(old_dir,
+						&old_dentry->d_name, &old_page);
+			if (!old_entry) {
+				err = -ENOENT;
+				if (IS_ERR(old_page))
+					err = PTR_ERR(old_page);
+				f2fs_unlock_op(sbi);
+				goto out_whiteout;
+			}
+		}
+	}
+
+	down_write(&F2FS_I(old_inode)->i_sem);
+	if (!old_dir_entry || whiteout)
+		file_lost_pino(old_inode);
+	else
+		/* adjust dir's i_pino to pass fsck check */
+		f2fs_i_pino_write(old_inode, new_dir->i_ino);
+	up_write(&F2FS_I(old_inode)->i_sem);
+
+	old_inode->i_ctime = current_time(old_inode);
+	f2fs_mark_inode_dirty_sync(old_inode, false);
+
+	f2fs_delete_entry(old_entry, old_page, old_dir, NULL);
+
+	if (whiteout) {
+		whiteout->i_state |= I_LINKABLE;
+		set_inode_flag(whiteout, FI_INC_LINK);
+		err = f2fs_add_link(old_dentry, whiteout);
+		if (err)
+			goto put_out_dir;
+		whiteout->i_state &= ~I_LINKABLE;
+		iput(whiteout);
+	}
+
+	if (old_dir_entry) {
+		if (old_dir != new_dir && !whiteout)
+			f2fs_set_link(old_inode, old_dir_entry,
+						old_dir_page, new_dir);
+		else
+			f2fs_put_page(old_dir_page, 0);
+		f2fs_i_links_write(old_dir, false);
+	}
+	if (F2FS_OPTION(sbi).fsync_mode == FSYNC_MODE_STRICT)
+		add_ino_entry(sbi, new_dir->i_ino, TRANS_DIR_INO);
+
+	f2fs_unlock_op(sbi);
+
+	if (IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir))
+		f2fs_sync_fs(sbi->sb, 1);
+	return 0;
+
+put_out_dir:
+	f2fs_unlock_op(sbi);
+	if (new_page)
+		f2fs_put_page(new_page, 0);
+out_whiteout:
+	if (whiteout)
+		iput(whiteout);
+out_dir:
+	if (old_dir_entry)
+		f2fs_put_page(old_dir_page, 0);
+out_old:
+	f2fs_put_page(old_page, 0);
+out:
+	return err;
+}
+
+static int f2fs_cross_rename(struct inode *old_dir, struct dentry *old_dentry,
+			     struct inode *new_dir, struct dentry *new_dentry)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(old_dir);
+	struct inode *old_inode = d_inode(old_dentry);
+	struct inode *new_inode = d_inode(new_dentry);
+	struct page *old_dir_page, *new_dir_page;
+	struct page *old_page, *new_page;
+	struct f2fs_dir_entry *old_dir_entry = NULL, *new_dir_entry = NULL;
+	struct f2fs_dir_entry *old_entry, *new_entry;
+	int old_nlink = 0, new_nlink = 0;
+	int err = -ENOENT;
+
+	if (unlikely(f2fs_cp_error(sbi)))
+		return -EIO;
+
+	if ((is_inode_flag_set(new_dir, FI_PROJ_INHERIT) &&
+			!projid_eq(F2FS_I(new_dir)->i_projid,
+			F2FS_I(old_dentry->d_inode)->i_projid)) ||
+	    (is_inode_flag_set(new_dir, FI_PROJ_INHERIT) &&
+			!projid_eq(F2FS_I(old_dir)->i_projid,
+			F2FS_I(new_dentry->d_inode)->i_projid)))
+		return -EXDEV;
+
+	err = dquot_initialize(old_dir);
+	if (err)
+		goto out;
+
+	err = dquot_initialize(new_dir);
+	if (err)
+		goto out;
+
+	old_entry = f2fs_find_entry(old_dir, &old_dentry->d_name, &old_page);
+	if (!old_entry) {
+		if (IS_ERR(old_page))
+			err = PTR_ERR(old_page);
+		goto out;
+	}
+
+	new_entry = f2fs_find_entry(new_dir, &new_dentry->d_name, &new_page);
+	if (!new_entry) {
+		if (IS_ERR(new_page))
+			err = PTR_ERR(new_page);
+		goto out_old;
+	}
+
+	/* prepare for updating ".." directory entry info later */
+	if (old_dir != new_dir) {
+		if (S_ISDIR(old_inode->i_mode)) {
+			old_dir_entry = f2fs_parent_dir(old_inode,
+							&old_dir_page);
+			if (!old_dir_entry) {
+				if (IS_ERR(old_dir_page))
+					err = PTR_ERR(old_dir_page);
+				goto out_new;
+			}
+		}
+
+		if (S_ISDIR(new_inode->i_mode)) {
+			new_dir_entry = f2fs_parent_dir(new_inode,
+							&new_dir_page);
+			if (!new_dir_entry) {
+				if (IS_ERR(new_dir_page))
+					err = PTR_ERR(new_dir_page);
+				goto out_old_dir;
+			}
+		}
+	}
+
+	/*
+	 * If cross rename between file and directory those are not
+	 * in the same directory, we will inc nlink of file's parent
+	 * later, so we should check upper boundary of its nlink.
+	 */
+	if ((!old_dir_entry || !new_dir_entry) &&
+				old_dir_entry != new_dir_entry) {
+		old_nlink = old_dir_entry ? -1 : 1;
+		new_nlink = -old_nlink;
+		err = -EMLINK;
+		if ((old_nlink > 0 && old_dir->i_nlink >= F2FS_LINK_MAX) ||
+			(new_nlink > 0 && new_dir->i_nlink >= F2FS_LINK_MAX))
+			goto out_new_dir;
+	}
+
+	f2fs_balance_fs(sbi, true);
+
+	f2fs_lock_op(sbi);
+
+	/* update ".." directory entry info of old dentry */
+	if (old_dir_entry)
+		f2fs_set_link(old_inode, old_dir_entry, old_dir_page, new_dir);
+
+	/* update ".." directory entry info of new dentry */
+	if (new_dir_entry)
+		f2fs_set_link(new_inode, new_dir_entry, new_dir_page, old_dir);
+
+	/* update directory entry info of old dir inode */
+	f2fs_set_link(old_dir, old_entry, old_page, new_inode);
+
+	down_write(&F2FS_I(old_inode)->i_sem);
+	if (!old_dir_entry)
+		file_lost_pino(old_inode);
+	else
+		/* adjust dir's i_pino to pass fsck check */
+		f2fs_i_pino_write(old_inode, new_dir->i_ino);
+	up_write(&F2FS_I(old_inode)->i_sem);
+
+	old_dir->i_ctime = current_time(old_dir);
+	if (old_nlink) {
+		down_write(&F2FS_I(old_dir)->i_sem);
+		f2fs_i_links_write(old_dir, old_nlink > 0);
+		up_write(&F2FS_I(old_dir)->i_sem);
+	}
+	f2fs_mark_inode_dirty_sync(old_dir, false);
+
+	/* update directory entry info of new dir inode */
+	f2fs_set_link(new_dir, new_entry, new_page, old_inode);
+
+	down_write(&F2FS_I(new_inode)->i_sem);
+	if (!new_dir_entry)
+		file_lost_pino(new_inode);
+	else
+		/* adjust dir's i_pino to pass fsck check */
+		f2fs_i_pino_write(new_inode, old_dir->i_ino);
+	up_write(&F2FS_I(new_inode)->i_sem);
+
+	new_dir->i_ctime = current_time(new_dir);
+	if (new_nlink) {
+		down_write(&F2FS_I(new_dir)->i_sem);
+		f2fs_i_links_write(new_dir, new_nlink > 0);
+		up_write(&F2FS_I(new_dir)->i_sem);
+	}
+	f2fs_mark_inode_dirty_sync(new_dir, false);
+
+	if (F2FS_OPTION(sbi).fsync_mode == FSYNC_MODE_STRICT) {
+		add_ino_entry(sbi, old_dir->i_ino, TRANS_DIR_INO);
+		add_ino_entry(sbi, new_dir->i_ino, TRANS_DIR_INO);
+	}
+
+	f2fs_unlock_op(sbi);
+
+	if (IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir))
+		f2fs_sync_fs(sbi->sb, 1);
+	return 0;
+out_new_dir:
+	if (new_dir_entry) {
+		f2fs_put_page(new_dir_page, 0);
+	}
+out_old_dir:
+	if (old_dir_entry) {
+		f2fs_put_page(old_dir_page, 0);
+	}
+out_new:
+	f2fs_put_page(new_page, 0);
+out_old:
+	f2fs_put_page(old_page, 0);
+out:
+	return err;
+}
+
+static int f2fs_rename2(struct inode *old_dir, struct dentry *old_dentry,
+			struct inode *new_dir, struct dentry *new_dentry,
+			unsigned int flags)
+{
+	int err;
+
+	if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT))
+		return -EINVAL;
+
+	err = fscrypt_prepare_rename(old_dir, old_dentry, new_dir, new_dentry,
+				     flags);
+	if (err)
+		return err;
+
+	if (flags & RENAME_EXCHANGE) {
+		return f2fs_cross_rename(old_dir, old_dentry,
+					 new_dir, new_dentry);
+	}
+	/*
+	 * VFS has already handled the new dentry existence case,
+	 * here, we just deal with "RENAME_NOREPLACE" as regular rename.
+	 */
+	return f2fs_rename(old_dir, old_dentry, new_dir, new_dentry, flags);
+}
+
+static const char *f2fs_encrypted_get_link(struct dentry *dentry,
+					   struct inode *inode,
+					   struct delayed_call *done)
+{
+	struct page *page;
+	const char *target;
+
+	if (!dentry)
+		return ERR_PTR(-ECHILD);
+
+	page = read_mapping_page(inode->i_mapping, 0, NULL);
+	if (IS_ERR(page))
+		return ERR_CAST(page);
+
+	target = fscrypt_get_symlink(inode, page_address(page),
+				     inode->i_sb->s_blocksize, done);
+	put_page(page);
+	return target;
+}
+
+const struct inode_operations f2fs_encrypted_symlink_inode_operations = {
+	.get_link       = f2fs_encrypted_get_link,
+	.getattr	= f2fs_getattr,
+	.setattr	= f2fs_setattr,
+#ifdef CONFIG_F2FS_FS_XATTR
+	.listxattr	= f2fs_listxattr,
+#endif
+};
+
+const struct inode_operations f2fs_dir_inode_operations = {
+	.create		= f2fs_create,
+	.lookup		= f2fs_lookup,
+	.link		= f2fs_link,
+	.unlink		= f2fs_unlink,
+	.symlink	= f2fs_symlink,
+	.mkdir		= f2fs_mkdir,
+	.rmdir		= f2fs_rmdir,
+	.mknod		= f2fs_mknod,
+	.rename		= f2fs_rename2,
+	.tmpfile	= f2fs_tmpfile,
+	.getattr	= f2fs_getattr,
+	.setattr	= f2fs_setattr,
+	.get_acl	= f2fs_get_acl,
+	.set_acl	= f2fs_set_acl,
+#ifdef CONFIG_F2FS_FS_XATTR
+	.listxattr	= f2fs_listxattr,
+#endif
+};
+
+const struct inode_operations f2fs_symlink_inode_operations = {
+	.get_link       = f2fs_get_link,
+	.getattr	= f2fs_getattr,
+	.setattr	= f2fs_setattr,
+#ifdef CONFIG_F2FS_FS_XATTR
+	.listxattr	= f2fs_listxattr,
+#endif
+};
+
+const struct inode_operations f2fs_special_inode_operations = {
+	.getattr	= f2fs_getattr,
+	.setattr        = f2fs_setattr,
+	.get_acl	= f2fs_get_acl,
+	.set_acl	= f2fs_set_acl,
+#ifdef CONFIG_F2FS_FS_XATTR
+	.listxattr	= f2fs_listxattr,
+#endif
+};
diff --git a/src/kernel/linux/v4.14/fs/f2fs/node.c b/src/kernel/linux/v4.14/fs/f2fs/node.c
new file mode 100644
index 0000000..6404873
--- /dev/null
+++ b/src/kernel/linux/v4.14/fs/f2fs/node.c
@@ -0,0 +1,2933 @@
+/*
+ * fs/f2fs/node.c
+ *
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ *             http://www.samsung.com/
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/fs.h>
+#include <linux/f2fs_fs.h>
+#include <linux/mpage.h>
+#include <linux/backing-dev.h>
+#include <linux/blkdev.h>
+#include <linux/pagevec.h>
+#include <linux/swap.h>
+
+#include "f2fs.h"
+#include "node.h"
+#include "segment.h"
+#include "xattr.h"
+#include "trace.h"
+#include <trace/events/f2fs.h>
+
+#define on_build_free_nids(nmi) mutex_is_locked(&(nm_i)->build_lock)
+
+static struct kmem_cache *nat_entry_slab;
+static struct kmem_cache *free_nid_slab;
+static struct kmem_cache *nat_entry_set_slab;
+
+/*
+ * Check whether the given nid is within node id range.
+ */
+int check_nid_range(struct f2fs_sb_info *sbi, nid_t nid)
+{
+	if (unlikely(nid < F2FS_ROOT_INO(sbi) || nid >= NM_I(sbi)->max_nid)) {
+		set_sbi_flag(sbi, SBI_NEED_FSCK);
+		f2fs_msg(sbi->sb, KERN_WARNING,
+				"%s: out-of-range nid=%x, run fsck to fix.",
+				__func__, nid);
+		return -EFSCORRUPTED;
+	}
+	return 0;
+}
+
+bool available_free_memory(struct f2fs_sb_info *sbi, int type)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	struct sysinfo val;
+	unsigned long avail_ram;
+	unsigned long mem_size = 0;
+	bool res = false;
+
+	si_meminfo(&val);
+
+	/* only uses low memory */
+	avail_ram = val.totalram - val.totalhigh;
+
+	/*
+	 * give 25%, 25%, 50%, 50%, 50% memory for each components respectively
+	 */
+	if (type == FREE_NIDS) {
+		mem_size = (nm_i->nid_cnt[FREE_NID] *
+				sizeof(struct free_nid)) >> PAGE_SHIFT;
+		res = mem_size < ((avail_ram * nm_i->ram_thresh / 100) >> 2);
+	} else if (type == NAT_ENTRIES) {
+		mem_size = (nm_i->nat_cnt * sizeof(struct nat_entry)) >>
+							PAGE_SHIFT;
+		res = mem_size < ((avail_ram * nm_i->ram_thresh / 100) >> 2);
+		if (excess_cached_nats(sbi))
+			res = false;
+	} else if (type == DIRTY_DENTS) {
+		if (sbi->sb->s_bdi->wb.dirty_exceeded)
+			return false;
+		mem_size = get_pages(sbi, F2FS_DIRTY_DENTS);
+		res = mem_size < ((avail_ram * nm_i->ram_thresh / 100) >> 1);
+	} else if (type == INO_ENTRIES) {
+		int i;
+
+		for (i = 0; i < MAX_INO_ENTRY; i++)
+			mem_size += sbi->im[i].ino_num *
+						sizeof(struct ino_entry);
+		mem_size >>= PAGE_SHIFT;
+		res = mem_size < ((avail_ram * nm_i->ram_thresh / 100) >> 1);
+	} else if (type == EXTENT_CACHE) {
+		mem_size = (atomic_read(&sbi->total_ext_tree) *
+				sizeof(struct extent_tree) +
+				atomic_read(&sbi->total_ext_node) *
+				sizeof(struct extent_node)) >> PAGE_SHIFT;
+		res = mem_size < ((avail_ram * nm_i->ram_thresh / 100) >> 1);
+	} else if (type == INMEM_PAGES) {
+		/* it allows 20% / total_ram for inmemory pages */
+		mem_size = get_pages(sbi, F2FS_INMEM_PAGES);
+		res = mem_size < (val.totalram / 5);
+	} else {
+		if (!sbi->sb->s_bdi->wb.dirty_exceeded)
+			return true;
+	}
+	return res;
+}
+
+static void clear_node_page_dirty(struct page *page)
+{
+	struct address_space *mapping = page->mapping;
+	unsigned int long flags;
+
+	if (PageDirty(page)) {
+		spin_lock_irqsave(&mapping->tree_lock, flags);
+		radix_tree_tag_clear(&mapping->page_tree,
+				page_index(page),
+				PAGECACHE_TAG_DIRTY);
+		spin_unlock_irqrestore(&mapping->tree_lock, flags);
+
+		clear_page_dirty_for_io(page);
+		dec_page_count(F2FS_M_SB(mapping), F2FS_DIRTY_NODES);
+	}
+	ClearPageUptodate(page);
+}
+
+static struct page *get_current_nat_page(struct f2fs_sb_info *sbi, nid_t nid)
+{
+	pgoff_t index = current_nat_addr(sbi, nid);
+	return get_meta_page(sbi, index);
+}
+
+static struct page *get_next_nat_page(struct f2fs_sb_info *sbi, nid_t nid)
+{
+	struct page *src_page;
+	struct page *dst_page;
+	pgoff_t src_off;
+	pgoff_t dst_off;
+	void *src_addr;
+	void *dst_addr;
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+
+	src_off = current_nat_addr(sbi, nid);
+	dst_off = next_nat_addr(sbi, src_off);
+
+	/* get current nat block page with lock */
+	src_page = get_meta_page(sbi, src_off);
+	dst_page = grab_meta_page(sbi, dst_off);
+	f2fs_bug_on(sbi, PageDirty(src_page));
+
+	src_addr = page_address(src_page);
+	dst_addr = page_address(dst_page);
+	memcpy(dst_addr, src_addr, PAGE_SIZE);
+	set_page_dirty(dst_page);
+	f2fs_put_page(src_page, 1);
+
+	set_to_next_nat(nm_i, nid);
+
+	return dst_page;
+}
+
+static struct nat_entry *__alloc_nat_entry(nid_t nid, bool no_fail)
+{
+	struct nat_entry *new;
+
+	if (no_fail)
+		new = f2fs_kmem_cache_alloc(nat_entry_slab, GFP_F2FS_ZERO);
+	else
+		new = kmem_cache_alloc(nat_entry_slab, GFP_F2FS_ZERO);
+	if (new) {
+		nat_set_nid(new, nid);
+		nat_reset_flag(new);
+	}
+	return new;
+}
+
+static void __free_nat_entry(struct nat_entry *e)
+{
+	kmem_cache_free(nat_entry_slab, e);
+}
+
+/* must be locked by nat_tree_lock */
+static struct nat_entry *__init_nat_entry(struct f2fs_nm_info *nm_i,
+	struct nat_entry *ne, struct f2fs_nat_entry *raw_ne, bool no_fail)
+{
+	if (no_fail)
+		f2fs_radix_tree_insert(&nm_i->nat_root, nat_get_nid(ne), ne);
+	else if (radix_tree_insert(&nm_i->nat_root, nat_get_nid(ne), ne))
+		return NULL;
+
+	if (raw_ne)
+		node_info_from_raw_nat(&ne->ni, raw_ne);
+	list_add_tail(&ne->list, &nm_i->nat_entries);
+	nm_i->nat_cnt++;
+	return ne;
+}
+
+static struct nat_entry *__lookup_nat_cache(struct f2fs_nm_info *nm_i, nid_t n)
+{
+	return radix_tree_lookup(&nm_i->nat_root, n);
+}
+
+static unsigned int __gang_lookup_nat_cache(struct f2fs_nm_info *nm_i,
+		nid_t start, unsigned int nr, struct nat_entry **ep)
+{
+	return radix_tree_gang_lookup(&nm_i->nat_root, (void **)ep, start, nr);
+}
+
+static void __del_from_nat_cache(struct f2fs_nm_info *nm_i, struct nat_entry *e)
+{
+	list_del(&e->list);
+	radix_tree_delete(&nm_i->nat_root, nat_get_nid(e));
+	nm_i->nat_cnt--;
+	__free_nat_entry(e);
+}
+
+static struct nat_entry_set *__grab_nat_entry_set(struct f2fs_nm_info *nm_i,
+							struct nat_entry *ne)
+{
+	nid_t set = NAT_BLOCK_OFFSET(ne->ni.nid);
+	struct nat_entry_set *head;
+
+	head = radix_tree_lookup(&nm_i->nat_set_root, set);
+	if (!head) {
+		head = f2fs_kmem_cache_alloc(nat_entry_set_slab, GFP_NOFS);
+
+		INIT_LIST_HEAD(&head->entry_list);
+		INIT_LIST_HEAD(&head->set_list);
+		head->set = set;
+		head->entry_cnt = 0;
+		f2fs_radix_tree_insert(&nm_i->nat_set_root, set, head);
+	}
+	return head;
+}
+
+static void __set_nat_cache_dirty(struct f2fs_nm_info *nm_i,
+						struct nat_entry *ne)
+{
+	struct nat_entry_set *head;
+	bool new_ne = nat_get_blkaddr(ne) == NEW_ADDR;
+
+	if (!new_ne)
+		head = __grab_nat_entry_set(nm_i, ne);
+
+	/*
+	 * update entry_cnt in below condition:
+	 * 1. update NEW_ADDR to valid block address;
+	 * 2. update old block address to new one;
+	 */
+	if (!new_ne && (get_nat_flag(ne, IS_PREALLOC) ||
+				!get_nat_flag(ne, IS_DIRTY)))
+		head->entry_cnt++;
+
+	set_nat_flag(ne, IS_PREALLOC, new_ne);
+
+	if (get_nat_flag(ne, IS_DIRTY))
+		goto refresh_list;
+
+	nm_i->dirty_nat_cnt++;
+	set_nat_flag(ne, IS_DIRTY, true);
+refresh_list:
+	if (new_ne)
+		list_del_init(&ne->list);
+	else
+		list_move_tail(&ne->list, &head->entry_list);
+}
+
+static void __clear_nat_cache_dirty(struct f2fs_nm_info *nm_i,
+		struct nat_entry_set *set, struct nat_entry *ne)
+{
+	list_move_tail(&ne->list, &nm_i->nat_entries);
+	set_nat_flag(ne, IS_DIRTY, false);
+	set->entry_cnt--;
+	nm_i->dirty_nat_cnt--;
+}
+
+static unsigned int __gang_lookup_nat_set(struct f2fs_nm_info *nm_i,
+		nid_t start, unsigned int nr, struct nat_entry_set **ep)
+{
+	return radix_tree_gang_lookup(&nm_i->nat_set_root, (void **)ep,
+							start, nr);
+}
+
+int need_dentry_mark(struct f2fs_sb_info *sbi, nid_t nid)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	struct nat_entry *e;
+	bool need = false;
+
+	down_read(&nm_i->nat_tree_lock);
+	e = __lookup_nat_cache(nm_i, nid);
+	if (e) {
+		if (!get_nat_flag(e, IS_CHECKPOINTED) &&
+				!get_nat_flag(e, HAS_FSYNCED_INODE))
+			need = true;
+	}
+	up_read(&nm_i->nat_tree_lock);
+	return need;
+}
+
+bool is_checkpointed_node(struct f2fs_sb_info *sbi, nid_t nid)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	struct nat_entry *e;
+	bool is_cp = true;
+
+	down_read(&nm_i->nat_tree_lock);
+	e = __lookup_nat_cache(nm_i, nid);
+	if (e && !get_nat_flag(e, IS_CHECKPOINTED))
+		is_cp = false;
+	up_read(&nm_i->nat_tree_lock);
+	return is_cp;
+}
+
+bool need_inode_block_update(struct f2fs_sb_info *sbi, nid_t ino)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	struct nat_entry *e;
+	bool need_update = true;
+
+	down_read(&nm_i->nat_tree_lock);
+	e = __lookup_nat_cache(nm_i, ino);
+	if (e && get_nat_flag(e, HAS_LAST_FSYNC) &&
+			(get_nat_flag(e, IS_CHECKPOINTED) ||
+			 get_nat_flag(e, HAS_FSYNCED_INODE)))
+		need_update = false;
+	up_read(&nm_i->nat_tree_lock);
+	return need_update;
+}
+
+/* must be locked by nat_tree_lock */
+static void cache_nat_entry(struct f2fs_sb_info *sbi, nid_t nid,
+						struct f2fs_nat_entry *ne)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	struct nat_entry *new, *e;
+
+	new = __alloc_nat_entry(nid, false);
+	if (!new)
+		return;
+
+	down_write(&nm_i->nat_tree_lock);
+	e = __lookup_nat_cache(nm_i, nid);
+	if (!e)
+		e = __init_nat_entry(nm_i, new, ne, false);
+	else
+		f2fs_bug_on(sbi, nat_get_ino(e) != le32_to_cpu(ne->ino) ||
+				nat_get_blkaddr(e) !=
+					le32_to_cpu(ne->block_addr) ||
+				nat_get_version(e) != ne->version);
+	up_write(&nm_i->nat_tree_lock);
+	if (e != new)
+		__free_nat_entry(new);
+}
+
+static void set_node_addr(struct f2fs_sb_info *sbi, struct node_info *ni,
+			block_t new_blkaddr, bool fsync_done)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	struct nat_entry *e;
+	struct nat_entry *new = __alloc_nat_entry(ni->nid, true);
+
+	down_write(&nm_i->nat_tree_lock);
+	e = __lookup_nat_cache(nm_i, ni->nid);
+	if (!e) {
+		e = __init_nat_entry(nm_i, new, NULL, true);
+		copy_node_info(&e->ni, ni);
+		f2fs_bug_on(sbi, ni->blk_addr == NEW_ADDR);
+	} else if (new_blkaddr == NEW_ADDR) {
+		/*
+		 * when nid is reallocated,
+		 * previous nat entry can be remained in nat cache.
+		 * So, reinitialize it with new information.
+		 */
+		copy_node_info(&e->ni, ni);
+		f2fs_bug_on(sbi, ni->blk_addr != NULL_ADDR);
+	}
+	/* let's free early to reduce memory consumption */
+	if (e != new)
+		__free_nat_entry(new);
+
+	/* sanity check */
+	f2fs_bug_on(sbi, nat_get_blkaddr(e) != ni->blk_addr);
+	f2fs_bug_on(sbi, nat_get_blkaddr(e) == NULL_ADDR &&
+			new_blkaddr == NULL_ADDR);
+	f2fs_bug_on(sbi, nat_get_blkaddr(e) == NEW_ADDR &&
+			new_blkaddr == NEW_ADDR);
+	f2fs_bug_on(sbi, is_valid_data_blkaddr(sbi, nat_get_blkaddr(e)) &&
+			new_blkaddr == NEW_ADDR);
+
+	/* increment version no as node is removed */
+	if (nat_get_blkaddr(e) != NEW_ADDR && new_blkaddr == NULL_ADDR) {
+		unsigned char version = nat_get_version(e);
+		nat_set_version(e, inc_node_version(version));
+	}
+
+	/* change address */
+	nat_set_blkaddr(e, new_blkaddr);
+	if (!is_valid_data_blkaddr(sbi, new_blkaddr))
+		set_nat_flag(e, IS_CHECKPOINTED, false);
+	__set_nat_cache_dirty(nm_i, e);
+
+	/* update fsync_mark if its inode nat entry is still alive */
+	if (ni->nid != ni->ino)
+		e = __lookup_nat_cache(nm_i, ni->ino);
+	if (e) {
+		if (fsync_done && ni->nid == ni->ino)
+			set_nat_flag(e, HAS_FSYNCED_INODE, true);
+		set_nat_flag(e, HAS_LAST_FSYNC, fsync_done);
+	}
+	up_write(&nm_i->nat_tree_lock);
+}
+
+int try_to_free_nats(struct f2fs_sb_info *sbi, int nr_shrink)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	int nr = nr_shrink;
+
+	if (!down_write_trylock(&nm_i->nat_tree_lock))
+		return 0;
+
+	while (nr_shrink && !list_empty(&nm_i->nat_entries)) {
+		struct nat_entry *ne;
+		ne = list_first_entry(&nm_i->nat_entries,
+					struct nat_entry, list);
+		__del_from_nat_cache(nm_i, ne);
+		nr_shrink--;
+	}
+	up_write(&nm_i->nat_tree_lock);
+	return nr - nr_shrink;
+}
+
+/*
+ * This function always returns success
+ */
+void get_node_info(struct f2fs_sb_info *sbi, nid_t nid, struct node_info *ni)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_HOT_DATA);
+	struct f2fs_journal *journal = curseg->journal;
+	nid_t start_nid = START_NID(nid);
+	struct f2fs_nat_block *nat_blk;
+	struct page *page = NULL;
+	struct f2fs_nat_entry ne;
+	struct nat_entry *e;
+	pgoff_t index;
+	int i;
+
+	ni->nid = nid;
+
+	/* Check nat cache */
+	down_read(&nm_i->nat_tree_lock);
+	e = __lookup_nat_cache(nm_i, nid);
+	if (e) {
+		ni->ino = nat_get_ino(e);
+		ni->blk_addr = nat_get_blkaddr(e);
+		ni->version = nat_get_version(e);
+		up_read(&nm_i->nat_tree_lock);
+		return;
+	}
+
+	memset(&ne, 0, sizeof(struct f2fs_nat_entry));
+
+	/* Check current segment summary */
+	down_read(&curseg->journal_rwsem);
+	i = lookup_journal_in_cursum(journal, NAT_JOURNAL, nid, 0);
+	if (i >= 0) {
+		ne = nat_in_journal(journal, i);
+		node_info_from_raw_nat(ni, &ne);
+	}
+	up_read(&curseg->journal_rwsem);
+	if (i >= 0) {
+		up_read(&nm_i->nat_tree_lock);
+		goto cache;
+	}
+
+	/* Fill node_info from nat page */
+	index = current_nat_addr(sbi, nid);
+	up_read(&nm_i->nat_tree_lock);
+
+	page = get_meta_page(sbi, index);
+	nat_blk = (struct f2fs_nat_block *)page_address(page);
+	ne = nat_blk->entries[nid - start_nid];
+	node_info_from_raw_nat(ni, &ne);
+	f2fs_put_page(page, 1);
+cache:
+	/* cache nat entry */
+	cache_nat_entry(sbi, nid, &ne);
+}
+
+/*
+ * readahead MAX_RA_NODE number of node pages.
+ */
+static void ra_node_pages(struct page *parent, int start, int n)
+{
+	struct f2fs_sb_info *sbi = F2FS_P_SB(parent);
+	struct blk_plug plug;
+	int i, end;
+	nid_t nid;
+
+	blk_start_plug(&plug);
+
+	/* Then, try readahead for siblings of the desired node */
+	end = start + n;
+	end = min(end, NIDS_PER_BLOCK);
+	for (i = start; i < end; i++) {
+		nid = get_nid(parent, i, false);
+		ra_node_page(sbi, nid);
+	}
+
+	blk_finish_plug(&plug);
+}
+
+pgoff_t get_next_page_offset(struct dnode_of_data *dn, pgoff_t pgofs)
+{
+	const long direct_index = ADDRS_PER_INODE(dn->inode);
+	const long direct_blks = ADDRS_PER_BLOCK;
+	const long indirect_blks = ADDRS_PER_BLOCK * NIDS_PER_BLOCK;
+	unsigned int skipped_unit = ADDRS_PER_BLOCK;
+	int cur_level = dn->cur_level;
+	int max_level = dn->max_level;
+	pgoff_t base = 0;
+
+	if (!dn->max_level)
+		return pgofs + 1;
+
+	while (max_level-- > cur_level)
+		skipped_unit *= NIDS_PER_BLOCK;
+
+	switch (dn->max_level) {
+	case 3:
+		base += 2 * indirect_blks;
+	case 2:
+		base += 2 * direct_blks;
+	case 1:
+		base += direct_index;
+		break;
+	default:
+		f2fs_bug_on(F2FS_I_SB(dn->inode), 1);
+	}
+
+	return ((pgofs - base) / skipped_unit + 1) * skipped_unit + base;
+}
+
+/*
+ * The maximum depth is four.
+ * Offset[0] will have raw inode offset.
+ */
+static int get_node_path(struct inode *inode, long block,
+				int offset[4], unsigned int noffset[4])
+{
+	const long direct_index = ADDRS_PER_INODE(inode);
+	const long direct_blks = ADDRS_PER_BLOCK;
+	const long dptrs_per_blk = NIDS_PER_BLOCK;
+	const long indirect_blks = ADDRS_PER_BLOCK * NIDS_PER_BLOCK;
+	const long dindirect_blks = indirect_blks * NIDS_PER_BLOCK;
+	int n = 0;
+	int level = 0;
+
+	noffset[0] = 0;
+
+	if (block < direct_index) {
+		offset[n] = block;
+		goto got;
+	}
+	block -= direct_index;
+	if (block < direct_blks) {
+		offset[n++] = NODE_DIR1_BLOCK;
+		noffset[n] = 1;
+		offset[n] = block;
+		level = 1;
+		goto got;
+	}
+	block -= direct_blks;
+	if (block < direct_blks) {
+		offset[n++] = NODE_DIR2_BLOCK;
+		noffset[n] = 2;
+		offset[n] = block;
+		level = 1;
+		goto got;
+	}
+	block -= direct_blks;
+	if (block < indirect_blks) {
+		offset[n++] = NODE_IND1_BLOCK;
+		noffset[n] = 3;
+		offset[n++] = block / direct_blks;
+		noffset[n] = 4 + offset[n - 1];
+		offset[n] = block % direct_blks;
+		level = 2;
+		goto got;
+	}
+	block -= indirect_blks;
+	if (block < indirect_blks) {
+		offset[n++] = NODE_IND2_BLOCK;
+		noffset[n] = 4 + dptrs_per_blk;
+		offset[n++] = block / direct_blks;
+		noffset[n] = 5 + dptrs_per_blk + offset[n - 1];
+		offset[n] = block % direct_blks;
+		level = 2;
+		goto got;
+	}
+	block -= indirect_blks;
+	if (block < dindirect_blks) {
+		offset[n++] = NODE_DIND_BLOCK;
+		noffset[n] = 5 + (dptrs_per_blk * 2);
+		offset[n++] = block / indirect_blks;
+		noffset[n] = 6 + (dptrs_per_blk * 2) +
+			      offset[n - 1] * (dptrs_per_blk + 1);
+		offset[n++] = (block / direct_blks) % dptrs_per_blk;
+		noffset[n] = 7 + (dptrs_per_blk * 2) +
+			      offset[n - 2] * (dptrs_per_blk + 1) +
+			      offset[n - 1];
+		offset[n] = block % direct_blks;
+		level = 3;
+		goto got;
+	} else {
+		return -E2BIG;
+	}
+got:
+	return level;
+}
+
+/*
+ * Caller should call f2fs_put_dnode(dn).
+ * Also, it should grab and release a rwsem by calling f2fs_lock_op() and
+ * f2fs_unlock_op() only if ro is not set RDONLY_NODE.
+ * In the case of RDONLY_NODE, we don't need to care about mutex.
+ */
+int get_dnode_of_data(struct dnode_of_data *dn, pgoff_t index, int mode)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(dn->inode);
+	struct page *npage[4];
+	struct page *parent = NULL;
+	int offset[4];
+	unsigned int noffset[4];
+	nid_t nids[4];
+	int level, i = 0;
+	int err = 0;
+
+	level = get_node_path(dn->inode, index, offset, noffset);
+	if (level < 0)
+		return level;
+
+	nids[0] = dn->inode->i_ino;
+	npage[0] = dn->inode_page;
+
+	if (!npage[0]) {
+		npage[0] = get_node_page(sbi, nids[0]);
+		if (IS_ERR(npage[0]))
+			return PTR_ERR(npage[0]);
+	}
+
+	/* if inline_data is set, should not report any block indices */
+	if (f2fs_has_inline_data(dn->inode) && index) {
+		err = -ENOENT;
+		f2fs_put_page(npage[0], 1);
+		goto release_out;
+	}
+
+	parent = npage[0];
+	if (level != 0)
+		nids[1] = get_nid(parent, offset[0], true);
+	dn->inode_page = npage[0];
+	dn->inode_page_locked = true;
+
+	/* get indirect or direct nodes */
+	for (i = 1; i <= level; i++) {
+		bool done = false;
+
+		if (!nids[i] && mode == ALLOC_NODE) {
+			/* alloc new node */
+			if (!alloc_nid(sbi, &(nids[i]))) {
+				err = -ENOSPC;
+				goto release_pages;
+			}
+
+			dn->nid = nids[i];
+			npage[i] = new_node_page(dn, noffset[i]);
+			if (IS_ERR(npage[i])) {
+				alloc_nid_failed(sbi, nids[i]);
+				err = PTR_ERR(npage[i]);
+				goto release_pages;
+			}
+
+			set_nid(parent, offset[i - 1], nids[i], i == 1);
+			alloc_nid_done(sbi, nids[i]);
+			done = true;
+		} else if (mode == LOOKUP_NODE_RA && i == level && level > 1) {
+			npage[i] = get_node_page_ra(parent, offset[i - 1]);
+			if (IS_ERR(npage[i])) {
+				err = PTR_ERR(npage[i]);
+				goto release_pages;
+			}
+			done = true;
+		}
+		if (i == 1) {
+			dn->inode_page_locked = false;
+			unlock_page(parent);
+		} else {
+			f2fs_put_page(parent, 1);
+		}
+
+		if (!done) {
+			npage[i] = get_node_page(sbi, nids[i]);
+			if (IS_ERR(npage[i])) {
+				err = PTR_ERR(npage[i]);
+				f2fs_put_page(npage[0], 0);
+				goto release_out;
+			}
+		}
+		if (i < level) {
+			parent = npage[i];
+			nids[i + 1] = get_nid(parent, offset[i], false);
+		}
+	}
+	dn->nid = nids[level];
+	dn->ofs_in_node = offset[level];
+	dn->node_page = npage[level];
+	dn->data_blkaddr = datablock_addr(dn->inode,
+				dn->node_page, dn->ofs_in_node);
+	return 0;
+
+release_pages:
+	f2fs_put_page(parent, 1);
+	if (i > 1)
+		f2fs_put_page(npage[0], 0);
+release_out:
+	dn->inode_page = NULL;
+	dn->node_page = NULL;
+	if (err == -ENOENT) {
+		dn->cur_level = i;
+		dn->max_level = level;
+		dn->ofs_in_node = offset[level];
+	}
+	return err;
+}
+
+static void truncate_node(struct dnode_of_data *dn)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(dn->inode);
+	struct node_info ni;
+	pgoff_t index;
+
+	get_node_info(sbi, dn->nid, &ni);
+
+	/* Deallocate node address */
+	invalidate_blocks(sbi, ni.blk_addr);
+	dec_valid_node_count(sbi, dn->inode, dn->nid == dn->inode->i_ino);
+	set_node_addr(sbi, &ni, NULL_ADDR, false);
+
+	if (dn->nid == dn->inode->i_ino) {
+		remove_orphan_inode(sbi, dn->nid);
+		dec_valid_inode_count(sbi);
+		f2fs_inode_synced(dn->inode);
+	}
+
+	clear_node_page_dirty(dn->node_page);
+	set_sbi_flag(sbi, SBI_IS_DIRTY);
+
+	index = dn->node_page->index;
+	f2fs_put_page(dn->node_page, 1);
+
+	invalidate_mapping_pages(NODE_MAPPING(sbi),
+			index, index);
+
+	dn->node_page = NULL;
+	trace_f2fs_truncate_node(dn->inode, dn->nid, ni.blk_addr);
+}
+
+static int truncate_dnode(struct dnode_of_data *dn)
+{
+	struct page *page;
+
+	if (dn->nid == 0)
+		return 1;
+
+	/* get direct node */
+	page = get_node_page(F2FS_I_SB(dn->inode), dn->nid);
+	if (IS_ERR(page) && PTR_ERR(page) == -ENOENT)
+		return 1;
+	else if (IS_ERR(page))
+		return PTR_ERR(page);
+
+	/* Make dnode_of_data for parameter */
+	dn->node_page = page;
+	dn->ofs_in_node = 0;
+	truncate_data_blocks(dn);
+	truncate_node(dn);
+	return 1;
+}
+
+static int truncate_nodes(struct dnode_of_data *dn, unsigned int nofs,
+						int ofs, int depth)
+{
+	struct dnode_of_data rdn = *dn;
+	struct page *page;
+	struct f2fs_node *rn;
+	nid_t child_nid;
+	unsigned int child_nofs;
+	int freed = 0;
+	int i, ret;
+
+	if (dn->nid == 0)
+		return NIDS_PER_BLOCK + 1;
+
+	trace_f2fs_truncate_nodes_enter(dn->inode, dn->nid, dn->data_blkaddr);
+
+	page = get_node_page(F2FS_I_SB(dn->inode), dn->nid);
+	if (IS_ERR(page)) {
+		trace_f2fs_truncate_nodes_exit(dn->inode, PTR_ERR(page));
+		return PTR_ERR(page);
+	}
+
+	ra_node_pages(page, ofs, NIDS_PER_BLOCK);
+
+	rn = F2FS_NODE(page);
+	if (depth < 3) {
+		for (i = ofs; i < NIDS_PER_BLOCK; i++, freed++) {
+			child_nid = le32_to_cpu(rn->in.nid[i]);
+			if (child_nid == 0)
+				continue;
+			rdn.nid = child_nid;
+			ret = truncate_dnode(&rdn);
+			if (ret < 0)
+				goto out_err;
+			if (set_nid(page, i, 0, false))
+				dn->node_changed = true;
+		}
+	} else {
+		child_nofs = nofs + ofs * (NIDS_PER_BLOCK + 1) + 1;
+		for (i = ofs; i < NIDS_PER_BLOCK; i++) {
+			child_nid = le32_to_cpu(rn->in.nid[i]);
+			if (child_nid == 0) {
+				child_nofs += NIDS_PER_BLOCK + 1;
+				continue;
+			}
+			rdn.nid = child_nid;
+			ret = truncate_nodes(&rdn, child_nofs, 0, depth - 1);
+			if (ret == (NIDS_PER_BLOCK + 1)) {
+				if (set_nid(page, i, 0, false))
+					dn->node_changed = true;
+				child_nofs += ret;
+			} else if (ret < 0 && ret != -ENOENT) {
+				goto out_err;
+			}
+		}
+		freed = child_nofs;
+	}
+
+	if (!ofs) {
+		/* remove current indirect node */
+		dn->node_page = page;
+		truncate_node(dn);
+		freed++;
+	} else {
+		f2fs_put_page(page, 1);
+	}
+	trace_f2fs_truncate_nodes_exit(dn->inode, freed);
+	return freed;
+
+out_err:
+	f2fs_put_page(page, 1);
+	trace_f2fs_truncate_nodes_exit(dn->inode, ret);
+	return ret;
+}
+
+static int truncate_partial_nodes(struct dnode_of_data *dn,
+			struct f2fs_inode *ri, int *offset, int depth)
+{
+	struct page *pages[2];
+	nid_t nid[3];
+	nid_t child_nid;
+	int err = 0;
+	int i;
+	int idx = depth - 2;
+
+	nid[0] = le32_to_cpu(ri->i_nid[offset[0] - NODE_DIR1_BLOCK]);
+	if (!nid[0])
+		return 0;
+
+	/* get indirect nodes in the path */
+	for (i = 0; i < idx + 1; i++) {
+		/* reference count'll be increased */
+		pages[i] = get_node_page(F2FS_I_SB(dn->inode), nid[i]);
+		if (IS_ERR(pages[i])) {
+			err = PTR_ERR(pages[i]);
+			idx = i - 1;
+			goto fail;
+		}
+		nid[i + 1] = get_nid(pages[i], offset[i + 1], false);
+	}
+
+	ra_node_pages(pages[idx], offset[idx + 1], NIDS_PER_BLOCK);
+
+	/* free direct nodes linked to a partial indirect node */
+	for (i = offset[idx + 1]; i < NIDS_PER_BLOCK; i++) {
+		child_nid = get_nid(pages[idx], i, false);
+		if (!child_nid)
+			continue;
+		dn->nid = child_nid;
+		err = truncate_dnode(dn);
+		if (err < 0)
+			goto fail;
+		if (set_nid(pages[idx], i, 0, false))
+			dn->node_changed = true;
+	}
+
+	if (offset[idx + 1] == 0) {
+		dn->node_page = pages[idx];
+		dn->nid = nid[idx];
+		truncate_node(dn);
+	} else {
+		f2fs_put_page(pages[idx], 1);
+	}
+	offset[idx]++;
+	offset[idx + 1] = 0;
+	idx--;
+fail:
+	for (i = idx; i >= 0; i--)
+		f2fs_put_page(pages[i], 1);
+
+	trace_f2fs_truncate_partial_nodes(dn->inode, nid, depth, err);
+
+	return err;
+}
+
+/*
+ * All the block addresses of data and nodes should be nullified.
+ */
+int truncate_inode_blocks(struct inode *inode, pgoff_t from)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	int err = 0, cont = 1;
+	int level, offset[4], noffset[4];
+	unsigned int nofs = 0;
+	struct f2fs_inode *ri;
+	struct dnode_of_data dn;
+	struct page *page;
+
+	trace_f2fs_truncate_inode_blocks_enter(inode, from);
+
+	level = get_node_path(inode, from, offset, noffset);
+	if (level < 0)
+		return level;
+
+	page = get_node_page(sbi, inode->i_ino);
+	if (IS_ERR(page)) {
+		trace_f2fs_truncate_inode_blocks_exit(inode, PTR_ERR(page));
+		return PTR_ERR(page);
+	}
+
+	set_new_dnode(&dn, inode, page, NULL, 0);
+	unlock_page(page);
+
+	ri = F2FS_INODE(page);
+	switch (level) {
+	case 0:
+	case 1:
+		nofs = noffset[1];
+		break;
+	case 2:
+		nofs = noffset[1];
+		if (!offset[level - 1])
+			goto skip_partial;
+		err = truncate_partial_nodes(&dn, ri, offset, level);
+		if (err < 0 && err != -ENOENT)
+			goto fail;
+		nofs += 1 + NIDS_PER_BLOCK;
+		break;
+	case 3:
+		nofs = 5 + 2 * NIDS_PER_BLOCK;
+		if (!offset[level - 1])
+			goto skip_partial;
+		err = truncate_partial_nodes(&dn, ri, offset, level);
+		if (err < 0 && err != -ENOENT)
+			goto fail;
+		break;
+	default:
+		BUG();
+	}
+
+skip_partial:
+	while (cont) {
+		dn.nid = le32_to_cpu(ri->i_nid[offset[0] - NODE_DIR1_BLOCK]);
+		switch (offset[0]) {
+		case NODE_DIR1_BLOCK:
+		case NODE_DIR2_BLOCK:
+			err = truncate_dnode(&dn);
+			break;
+
+		case NODE_IND1_BLOCK:
+		case NODE_IND2_BLOCK:
+			err = truncate_nodes(&dn, nofs, offset[1], 2);
+			break;
+
+		case NODE_DIND_BLOCK:
+			err = truncate_nodes(&dn, nofs, offset[1], 3);
+			cont = 0;
+			break;
+
+		default:
+			BUG();
+		}
+		if (err < 0 && err != -ENOENT)
+			goto fail;
+		if (offset[1] == 0 &&
+				ri->i_nid[offset[0] - NODE_DIR1_BLOCK]) {
+			lock_page(page);
+			BUG_ON(page->mapping != NODE_MAPPING(sbi));
+			f2fs_wait_on_page_writeback(page, NODE, true);
+			ri->i_nid[offset[0] - NODE_DIR1_BLOCK] = 0;
+			set_page_dirty(page);
+			unlock_page(page);
+		}
+		offset[1] = 0;
+		offset[0]++;
+		nofs += err;
+	}
+fail:
+	f2fs_put_page(page, 0);
+	trace_f2fs_truncate_inode_blocks_exit(inode, err);
+	return err > 0 ? 0 : err;
+}
+
+/* caller must lock inode page */
+int truncate_xattr_node(struct inode *inode)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	nid_t nid = F2FS_I(inode)->i_xattr_nid;
+	struct dnode_of_data dn;
+	struct page *npage;
+
+	if (!nid)
+		return 0;
+
+	npage = get_node_page(sbi, nid);
+	if (IS_ERR(npage))
+		return PTR_ERR(npage);
+
+	f2fs_i_xnid_write(inode, 0);
+
+	set_new_dnode(&dn, inode, NULL, npage, nid);
+	truncate_node(&dn);
+	return 0;
+}
+
+/*
+ * Caller should grab and release a rwsem by calling f2fs_lock_op() and
+ * f2fs_unlock_op().
+ */
+int remove_inode_page(struct inode *inode)
+{
+	struct dnode_of_data dn;
+	int err;
+
+	set_new_dnode(&dn, inode, NULL, NULL, inode->i_ino);
+	err = get_dnode_of_data(&dn, 0, LOOKUP_NODE);
+	if (err)
+		return err;
+
+	err = truncate_xattr_node(inode);
+	if (err) {
+		f2fs_put_dnode(&dn);
+		return err;
+	}
+
+	/* remove potential inline_data blocks */
+	if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
+				S_ISLNK(inode->i_mode))
+		truncate_data_blocks_range(&dn, 1);
+
+	/* 0 is possible, after f2fs_new_inode() has failed */
+	f2fs_bug_on(F2FS_I_SB(inode),
+			inode->i_blocks != 0 && inode->i_blocks != 8);
+
+	/* will put inode & node pages */
+	truncate_node(&dn);
+	return 0;
+}
+
+struct page *new_inode_page(struct inode *inode)
+{
+	struct dnode_of_data dn;
+
+	/* allocate inode page for new inode */
+	set_new_dnode(&dn, inode, NULL, NULL, inode->i_ino);
+
+	/* caller should f2fs_put_page(page, 1); */
+	return new_node_page(&dn, 0);
+}
+
+struct page *new_node_page(struct dnode_of_data *dn, unsigned int ofs)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(dn->inode);
+	struct node_info new_ni;
+	struct page *page;
+	int err;
+
+	if (unlikely(is_inode_flag_set(dn->inode, FI_NO_ALLOC)))
+		return ERR_PTR(-EPERM);
+
+	page = f2fs_grab_cache_page(NODE_MAPPING(sbi), dn->nid, false);
+	if (!page)
+		return ERR_PTR(-ENOMEM);
+
+	if (unlikely((err = inc_valid_node_count(sbi, dn->inode, !ofs))))
+		goto fail;
+
+#ifdef CONFIG_F2FS_CHECK_FS
+	get_node_info(sbi, dn->nid, &new_ni);
+	f2fs_bug_on(sbi, new_ni.blk_addr != NULL_ADDR);
+#endif
+	new_ni.nid = dn->nid;
+	new_ni.ino = dn->inode->i_ino;
+	new_ni.blk_addr = NULL_ADDR;
+	new_ni.flag = 0;
+	new_ni.version = 0;
+	set_node_addr(sbi, &new_ni, NEW_ADDR, false);
+
+	f2fs_wait_on_page_writeback(page, NODE, true);
+	fill_node_footer(page, dn->nid, dn->inode->i_ino, ofs, true);
+	set_cold_node(page, S_ISDIR(dn->inode->i_mode));
+	if (!PageUptodate(page))
+		SetPageUptodate(page);
+	if (set_page_dirty(page))
+		dn->node_changed = true;
+
+	if (f2fs_has_xattr_block(ofs))
+		f2fs_i_xnid_write(dn->inode, dn->nid);
+
+	if (ofs == 0)
+		inc_valid_inode_count(sbi);
+	return page;
+
+fail:
+	clear_node_page_dirty(page);
+	f2fs_put_page(page, 1);
+	return ERR_PTR(err);
+}
+
+/*
+ * Caller should do after getting the following values.
+ * 0: f2fs_put_page(page, 0)
+ * LOCKED_PAGE or error: f2fs_put_page(page, 1)
+ */
+static int read_node_page(struct page *page, int op_flags)
+{
+	struct f2fs_sb_info *sbi = F2FS_P_SB(page);
+	struct node_info ni;
+	struct f2fs_io_info fio = {
+		.sbi = sbi,
+		.type = NODE,
+		.op = REQ_OP_READ,
+		.op_flags = op_flags,
+		.page = page,
+		.encrypted_page = NULL,
+	};
+
+	if (PageUptodate(page))
+		return LOCKED_PAGE;
+
+	get_node_info(sbi, page->index, &ni);
+
+	if (unlikely(ni.blk_addr == NULL_ADDR)) {
+		ClearPageUptodate(page);
+		return -ENOENT;
+	}
+
+	fio.new_blkaddr = fio.old_blkaddr = ni.blk_addr;
+	return f2fs_submit_page_bio(&fio);
+}
+
+/*
+ * Readahead a node page
+ */
+void ra_node_page(struct f2fs_sb_info *sbi, nid_t nid)
+{
+	struct page *apage;
+	int err;
+
+	if (!nid)
+		return;
+	if (check_nid_range(sbi, nid))
+		return;
+
+	rcu_read_lock();
+	apage = radix_tree_lookup(&NODE_MAPPING(sbi)->page_tree, nid);
+	rcu_read_unlock();
+	if (apage)
+		return;
+
+	apage = f2fs_grab_cache_page(NODE_MAPPING(sbi), nid, false);
+	if (!apage)
+		return;
+
+	err = read_node_page(apage, REQ_RAHEAD);
+	f2fs_put_page(apage, err ? 1 : 0);
+}
+
+static struct page *__get_node_page(struct f2fs_sb_info *sbi, pgoff_t nid,
+					struct page *parent, int start)
+{
+	struct page *page;
+	int err;
+
+	if (!nid)
+		return ERR_PTR(-ENOENT);
+	if (check_nid_range(sbi, nid))
+		return ERR_PTR(-EINVAL);
+repeat:
+	page = f2fs_grab_cache_page(NODE_MAPPING(sbi), nid, false);
+	if (!page)
+		return ERR_PTR(-ENOMEM);
+
+	err = read_node_page(page, 0);
+	if (err < 0) {
+		f2fs_put_page(page, 1);
+		return ERR_PTR(err);
+	} else if (err == LOCKED_PAGE) {
+		err = 0;
+		goto page_hit;
+	}
+
+	if (parent)
+		ra_node_pages(parent, start + 1, MAX_RA_NODE);
+
+	lock_page(page);
+
+	if (unlikely(page->mapping != NODE_MAPPING(sbi))) {
+		f2fs_put_page(page, 1);
+		goto repeat;
+	}
+
+	if (unlikely(!PageUptodate(page))) {
+		err = -EIO;
+		goto out_err;
+	}
+
+	if (!f2fs_inode_chksum_verify(sbi, page)) {
+		err = -EFSBADCRC;
+		goto out_err;
+	}
+page_hit:
+	if(unlikely(nid != nid_of_node(page))) {
+		f2fs_msg(sbi->sb, KERN_WARNING, "inconsistent node block, "
+			"nid:%lu, node_footer[nid:%u,ino:%u,ofs:%u,cpver:%llu,blkaddr:%u]",
+			nid, nid_of_node(page), ino_of_node(page),
+			ofs_of_node(page), cpver_of_node(page),
+			next_blkaddr_of_node(page));
+		err = -EINVAL;
+out_err:
+		ClearPageUptodate(page);
+		f2fs_put_page(page, 1);
+		return ERR_PTR(err);
+	}
+	return page;
+}
+
+struct page *get_node_page(struct f2fs_sb_info *sbi, pgoff_t nid)
+{
+	return __get_node_page(sbi, nid, NULL, 0);
+}
+
+struct page *get_node_page_ra(struct page *parent, int start)
+{
+	struct f2fs_sb_info *sbi = F2FS_P_SB(parent);
+	nid_t nid = get_nid(parent, start, false);
+
+	return __get_node_page(sbi, nid, parent, start);
+}
+
+static void flush_inline_data(struct f2fs_sb_info *sbi, nid_t ino)
+{
+	struct inode *inode;
+	struct page *page;
+	int ret;
+
+	/* should flush inline_data before evict_inode */
+	inode = ilookup(sbi->sb, ino);
+	if (!inode)
+		return;
+
+	page = f2fs_pagecache_get_page(inode->i_mapping, 0,
+					FGP_LOCK|FGP_NOWAIT, 0);
+	if (!page)
+		goto iput_out;
+
+	if (!PageUptodate(page))
+		goto page_out;
+
+	if (!PageDirty(page))
+		goto page_out;
+
+	if (!clear_page_dirty_for_io(page))
+		goto page_out;
+
+	ret = f2fs_write_inline_data(inode, page);
+	inode_dec_dirty_pages(inode);
+	remove_dirty_inode(inode);
+	if (ret)
+		set_page_dirty(page);
+page_out:
+	f2fs_put_page(page, 1);
+iput_out:
+	iput(inode);
+}
+
+static struct page *last_fsync_dnode(struct f2fs_sb_info *sbi, nid_t ino)
+{
+	pgoff_t index, end;
+	struct pagevec pvec;
+	struct page *last_page = NULL;
+
+	pagevec_init(&pvec, 0);
+	index = 0;
+	end = ULONG_MAX;
+
+	while (index <= end) {
+		int i, nr_pages;
+		nr_pages = pagevec_lookup_tag(&pvec, NODE_MAPPING(sbi), &index,
+				PAGECACHE_TAG_DIRTY,
+				min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1);
+		if (nr_pages == 0)
+			break;
+
+		for (i = 0; i < nr_pages; i++) {
+			struct page *page = pvec.pages[i];
+
+			if (unlikely(f2fs_cp_error(sbi))) {
+				f2fs_put_page(last_page, 0);
+				pagevec_release(&pvec);
+				return ERR_PTR(-EIO);
+			}
+
+			if (!IS_DNODE(page) || !is_cold_node(page))
+				continue;
+			if (ino_of_node(page) != ino)
+				continue;
+
+			lock_page(page);
+
+			if (unlikely(page->mapping != NODE_MAPPING(sbi))) {
+continue_unlock:
+				unlock_page(page);
+				continue;
+			}
+			if (ino_of_node(page) != ino)
+				goto continue_unlock;
+
+			if (!PageDirty(page)) {
+				/* someone wrote it for us */
+				goto continue_unlock;
+			}
+
+			if (last_page)
+				f2fs_put_page(last_page, 0);
+
+			get_page(page);
+			last_page = page;
+			unlock_page(page);
+		}
+		pagevec_release(&pvec);
+		cond_resched();
+	}
+	return last_page;
+}
+
+static int __write_node_page(struct page *page, bool atomic, bool *submitted,
+				struct writeback_control *wbc, bool do_balance,
+				enum iostat_type io_type)
+{
+	struct f2fs_sb_info *sbi = F2FS_P_SB(page);
+	nid_t nid;
+	struct node_info ni;
+	struct f2fs_io_info fio = {
+		.sbi = sbi,
+		.ino = ino_of_node(page),
+		.type = NODE,
+		.op = REQ_OP_WRITE,
+		.op_flags = wbc_to_write_flags(wbc),
+		.page = page,
+		.encrypted_page = NULL,
+		.submitted = false,
+		.io_type = io_type,
+		.io_wbc = wbc,
+	};
+
+	trace_f2fs_writepage(page, NODE);
+
+	if (unlikely(f2fs_cp_error(sbi))) {
+		dec_page_count(sbi, F2FS_DIRTY_NODES);
+		unlock_page(page);
+		return 0;
+	}
+
+	if (unlikely(is_sbi_flag_set(sbi, SBI_POR_DOING)))
+		goto redirty_out;
+
+	/* get old block addr of this node page */
+	nid = nid_of_node(page);
+	f2fs_bug_on(sbi, page->index != nid);
+
+	if (wbc->for_reclaim) {
+		if (!down_read_trylock(&sbi->node_write))
+			goto redirty_out;
+	} else {
+		down_read(&sbi->node_write);
+	}
+
+	get_node_info(sbi, nid, &ni);
+
+	/* This page is already truncated */
+	if (unlikely(ni.blk_addr == NULL_ADDR)) {
+		ClearPageUptodate(page);
+		dec_page_count(sbi, F2FS_DIRTY_NODES);
+		up_read(&sbi->node_write);
+		unlock_page(page);
+		return 0;
+	}
+
+	if (__is_valid_data_blkaddr(ni.blk_addr) &&
+		!f2fs_is_valid_blkaddr(sbi, ni.blk_addr, DATA_GENERIC)) {
+		up_read(&sbi->node_write);
+		goto redirty_out;
+	}
+
+	if (atomic && !test_opt(sbi, NOBARRIER))
+		fio.op_flags |= REQ_PREFLUSH | REQ_FUA;
+
+	set_page_writeback(page);
+	ClearPageError(page);
+	fio.old_blkaddr = ni.blk_addr;
+	write_node_page(nid, &fio);
+	set_node_addr(sbi, &ni, fio.new_blkaddr, is_fsync_dnode(page));
+	dec_page_count(sbi, F2FS_DIRTY_NODES);
+	up_read(&sbi->node_write);
+
+	if (wbc->for_reclaim) {
+		f2fs_submit_merged_write_cond(sbi, page->mapping->host, 0,
+						page->index, NODE);
+		submitted = NULL;
+	}
+
+	unlock_page(page);
+
+	if (unlikely(f2fs_cp_error(sbi))) {
+		f2fs_submit_merged_write(sbi, NODE);
+		submitted = NULL;
+	}
+	if (submitted)
+		*submitted = fio.submitted;
+
+	if (do_balance)
+		f2fs_balance_fs(sbi, false);
+	return 0;
+
+redirty_out:
+	redirty_page_for_writepage(wbc, page);
+	return AOP_WRITEPAGE_ACTIVATE;
+}
+
+void move_node_page(struct page *node_page, int gc_type)
+{
+	if (gc_type == FG_GC) {
+		struct writeback_control wbc = {
+			.sync_mode = WB_SYNC_ALL,
+			.nr_to_write = 1,
+			.for_reclaim = 0,
+		};
+
+		set_page_dirty(node_page);
+		f2fs_wait_on_page_writeback(node_page, NODE, true);
+
+		f2fs_bug_on(F2FS_P_SB(node_page), PageWriteback(node_page));
+		if (!clear_page_dirty_for_io(node_page))
+			goto out_page;
+
+		if (__write_node_page(node_page, false, NULL,
+					&wbc, false, FS_GC_NODE_IO))
+			unlock_page(node_page);
+		goto release_page;
+	} else {
+		/* set page dirty and write it */
+		if (!PageWriteback(node_page))
+			set_page_dirty(node_page);
+	}
+out_page:
+	unlock_page(node_page);
+release_page:
+	f2fs_put_page(node_page, 0);
+}
+
+static int f2fs_write_node_page(struct page *page,
+				struct writeback_control *wbc)
+{
+	return __write_node_page(page, false, NULL, wbc, false, FS_NODE_IO);
+}
+
+int fsync_node_pages(struct f2fs_sb_info *sbi, struct inode *inode,
+			struct writeback_control *wbc, bool atomic)
+{
+	pgoff_t index, end;
+	pgoff_t last_idx = ULONG_MAX;
+	struct pagevec pvec;
+	int ret = 0;
+	struct page *last_page = NULL;
+	bool marked = false;
+	nid_t ino = inode->i_ino;
+
+	if (atomic) {
+		last_page = last_fsync_dnode(sbi, ino);
+		if (IS_ERR_OR_NULL(last_page))
+			return PTR_ERR_OR_ZERO(last_page);
+	}
+retry:
+	pagevec_init(&pvec, 0);
+	index = 0;
+	end = ULONG_MAX;
+
+	while (index <= end) {
+		int i, nr_pages;
+		nr_pages = pagevec_lookup_tag(&pvec, NODE_MAPPING(sbi), &index,
+				PAGECACHE_TAG_DIRTY,
+				min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1);
+		if (nr_pages == 0)
+			break;
+
+		for (i = 0; i < nr_pages; i++) {
+			struct page *page = pvec.pages[i];
+			bool submitted = false;
+
+			if (unlikely(f2fs_cp_error(sbi))) {
+				f2fs_put_page(last_page, 0);
+				pagevec_release(&pvec);
+				ret = -EIO;
+				goto out;
+			}
+
+			if (!IS_DNODE(page) || !is_cold_node(page))
+				continue;
+			if (ino_of_node(page) != ino)
+				continue;
+
+			lock_page(page);
+
+			if (unlikely(page->mapping != NODE_MAPPING(sbi))) {
+continue_unlock:
+				unlock_page(page);
+				continue;
+			}
+			if (ino_of_node(page) != ino)
+				goto continue_unlock;
+
+			if (!PageDirty(page) && page != last_page) {
+				/* someone wrote it for us */
+				goto continue_unlock;
+			}
+
+			f2fs_wait_on_page_writeback(page, NODE, true);
+			BUG_ON(PageWriteback(page));
+
+			set_fsync_mark(page, 0);
+			set_dentry_mark(page, 0);
+
+			if (!atomic || page == last_page) {
+				set_fsync_mark(page, 1);
+				if (IS_INODE(page)) {
+					if (is_inode_flag_set(inode,
+								FI_DIRTY_INODE))
+						update_inode(inode, page);
+					set_dentry_mark(page,
+						need_dentry_mark(sbi, ino));
+				}
+				/*  may be written by other thread */
+				if (!PageDirty(page))
+					set_page_dirty(page);
+			}
+
+			if (!clear_page_dirty_for_io(page))
+				goto continue_unlock;
+
+			ret = __write_node_page(page, atomic &&
+						page == last_page,
+						&submitted, wbc, true,
+						FS_NODE_IO);
+			if (ret) {
+				unlock_page(page);
+				f2fs_put_page(last_page, 0);
+				break;
+			} else if (submitted) {
+				last_idx = page->index;
+			}
+
+			if (page == last_page) {
+				f2fs_put_page(page, 0);
+				marked = true;
+				break;
+			}
+		}
+		pagevec_release(&pvec);
+		cond_resched();
+
+		if (ret || marked)
+			break;
+	}
+	if (!ret && atomic && !marked) {
+		f2fs_msg(sbi->sb, KERN_DEBUG,
+			"Retry to write fsync mark: ino=%u, idx=%lx",
+					ino, last_page->index);
+		lock_page(last_page);
+		f2fs_wait_on_page_writeback(last_page, NODE, true);
+		set_page_dirty(last_page);
+		unlock_page(last_page);
+		goto retry;
+	}
+out:
+	if (last_idx != ULONG_MAX)
+		f2fs_submit_merged_write_cond(sbi, NULL, ino, last_idx, NODE);
+	return ret ? -EIO: 0;
+}
+
+int sync_node_pages(struct f2fs_sb_info *sbi, struct writeback_control *wbc,
+				bool do_balance, enum iostat_type io_type)
+{
+	pgoff_t index, end;
+	struct pagevec pvec;
+	int step = 0;
+	int nwritten = 0;
+	int ret = 0;
+
+	pagevec_init(&pvec, 0);
+
+next_step:
+	index = 0;
+	end = ULONG_MAX;
+
+	while (index <= end) {
+		int i, nr_pages;
+		nr_pages = pagevec_lookup_tag(&pvec, NODE_MAPPING(sbi), &index,
+				PAGECACHE_TAG_DIRTY,
+				min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1);
+		if (nr_pages == 0)
+			break;
+
+		for (i = 0; i < nr_pages; i++) {
+			struct page *page = pvec.pages[i];
+			bool submitted = false;
+
+			/*
+			 * flushing sequence with step:
+			 * 0. indirect nodes
+			 * 1. dentry dnodes
+			 * 2. file dnodes
+			 */
+			if (step == 0 && IS_DNODE(page))
+				continue;
+			if (step == 1 && (!IS_DNODE(page) ||
+						is_cold_node(page)))
+				continue;
+			if (step == 2 && (!IS_DNODE(page) ||
+						!is_cold_node(page)))
+				continue;
+lock_node:
+			if (wbc->sync_mode == WB_SYNC_ALL)
+				lock_page(page);
+			else if (!trylock_page(page))
+				continue;
+
+			if (unlikely(page->mapping != NODE_MAPPING(sbi))) {
+continue_unlock:
+				unlock_page(page);
+				continue;
+			}
+
+			if (!PageDirty(page)) {
+				/* someone wrote it for us */
+				goto continue_unlock;
+			}
+
+			/* flush inline_data */
+			if (is_inline_node(page)) {
+				clear_inline_node(page);
+				unlock_page(page);
+				flush_inline_data(sbi, ino_of_node(page));
+				goto lock_node;
+			}
+
+			f2fs_wait_on_page_writeback(page, NODE, true);
+
+			BUG_ON(PageWriteback(page));
+			if (!clear_page_dirty_for_io(page))
+				goto continue_unlock;
+
+			set_fsync_mark(page, 0);
+			set_dentry_mark(page, 0);
+
+			ret = __write_node_page(page, false, &submitted,
+						wbc, do_balance, io_type);
+			if (ret)
+				unlock_page(page);
+			else if (submitted)
+				nwritten++;
+
+			if (--wbc->nr_to_write == 0)
+				break;
+		}
+		pagevec_release(&pvec);
+		cond_resched();
+
+		if (wbc->nr_to_write == 0) {
+			step = 2;
+			break;
+		}
+	}
+
+	if (step < 2) {
+		step++;
+		goto next_step;
+	}
+
+	if (nwritten)
+		f2fs_submit_merged_write(sbi, NODE);
+
+	if (unlikely(f2fs_cp_error(sbi)))
+		return -EIO;
+	return ret;
+}
+
+int wait_on_node_pages_writeback(struct f2fs_sb_info *sbi, nid_t ino)
+{
+	pgoff_t index = 0, end = ULONG_MAX;
+	struct pagevec pvec;
+	int ret2, ret = 0;
+
+	pagevec_init(&pvec, 0);
+
+	while (index <= end) {
+		int i, nr_pages;
+		nr_pages = pagevec_lookup_tag(&pvec, NODE_MAPPING(sbi), &index,
+				PAGECACHE_TAG_WRITEBACK,
+				min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1);
+		if (nr_pages == 0)
+			break;
+
+		for (i = 0; i < nr_pages; i++) {
+			struct page *page = pvec.pages[i];
+
+			/* until radix tree lookup accepts end_index */
+			if (unlikely(page->index > end))
+				continue;
+
+			if (ino && ino_of_node(page) == ino) {
+				f2fs_wait_on_page_writeback(page, NODE, true);
+				if (TestClearPageError(page))
+					ret = -EIO;
+			}
+		}
+		pagevec_release(&pvec);
+		cond_resched();
+	}
+
+	ret2 = filemap_check_errors(NODE_MAPPING(sbi));
+	if (!ret)
+		ret = ret2;
+	return ret;
+}
+
+static int f2fs_write_node_pages(struct address_space *mapping,
+			    struct writeback_control *wbc)
+{
+	struct f2fs_sb_info *sbi = F2FS_M_SB(mapping);
+	struct blk_plug plug;
+	long diff;
+
+	if (unlikely(is_sbi_flag_set(sbi, SBI_POR_DOING)))
+		goto skip_write;
+
+	/* balancing f2fs's metadata in background */
+	f2fs_balance_fs_bg(sbi);
+
+	/* collect a number of dirty node pages and write together */
+	if (get_pages(sbi, F2FS_DIRTY_NODES) < nr_pages_to_skip(sbi, NODE))
+		goto skip_write;
+
+	trace_f2fs_writepages(mapping->host, wbc, NODE);
+
+	diff = nr_pages_to_write(sbi, NODE, wbc);
+	wbc->sync_mode = WB_SYNC_NONE;
+	blk_start_plug(&plug);
+	sync_node_pages(sbi, wbc, true, FS_NODE_IO);
+	blk_finish_plug(&plug);
+	wbc->nr_to_write = max((long)0, wbc->nr_to_write - diff);
+	return 0;
+
+skip_write:
+	wbc->pages_skipped += get_pages(sbi, F2FS_DIRTY_NODES);
+	trace_f2fs_writepages(mapping->host, wbc, NODE);
+	return 0;
+}
+
+static int f2fs_set_node_page_dirty(struct page *page)
+{
+	trace_f2fs_set_page_dirty(page, NODE);
+
+	if (!PageUptodate(page))
+		SetPageUptodate(page);
+	if (!PageDirty(page)) {
+		__set_page_dirty_nobuffers(page);
+		inc_page_count(F2FS_P_SB(page), F2FS_DIRTY_NODES);
+		SetPagePrivate(page);
+		f2fs_trace_pid(page);
+		return 1;
+	}
+	return 0;
+}
+
+/*
+ * Structure of the f2fs node operations
+ */
+const struct address_space_operations f2fs_node_aops = {
+	.writepage	= f2fs_write_node_page,
+	.writepages	= f2fs_write_node_pages,
+	.set_page_dirty	= f2fs_set_node_page_dirty,
+	.invalidatepage	= f2fs_invalidate_page,
+	.releasepage	= f2fs_release_page,
+#ifdef CONFIG_MIGRATION
+	.migratepage    = f2fs_migrate_page,
+#endif
+};
+
+static struct free_nid *__lookup_free_nid_list(struct f2fs_nm_info *nm_i,
+						nid_t n)
+{
+	return radix_tree_lookup(&nm_i->free_nid_root, n);
+}
+
+static int __insert_free_nid(struct f2fs_sb_info *sbi,
+			struct free_nid *i, enum nid_state state)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+
+	int err = radix_tree_insert(&nm_i->free_nid_root, i->nid, i);
+	if (err)
+		return err;
+
+	f2fs_bug_on(sbi, state != i->state);
+	nm_i->nid_cnt[state]++;
+	if (state == FREE_NID)
+		list_add_tail(&i->list, &nm_i->free_nid_list);
+	return 0;
+}
+
+static void __remove_free_nid(struct f2fs_sb_info *sbi,
+			struct free_nid *i, enum nid_state state)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+
+	f2fs_bug_on(sbi, state != i->state);
+	nm_i->nid_cnt[state]--;
+	if (state == FREE_NID)
+		list_del(&i->list);
+	radix_tree_delete(&nm_i->free_nid_root, i->nid);
+}
+
+static void __move_free_nid(struct f2fs_sb_info *sbi, struct free_nid *i,
+			enum nid_state org_state, enum nid_state dst_state)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+
+	f2fs_bug_on(sbi, org_state != i->state);
+	i->state = dst_state;
+	nm_i->nid_cnt[org_state]--;
+	nm_i->nid_cnt[dst_state]++;
+
+	switch (dst_state) {
+	case PREALLOC_NID:
+		list_del(&i->list);
+		break;
+	case FREE_NID:
+		list_add_tail(&i->list, &nm_i->free_nid_list);
+		break;
+	default:
+		BUG_ON(1);
+	}
+}
+
+static void update_free_nid_bitmap(struct f2fs_sb_info *sbi, nid_t nid,
+							bool set, bool build)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	unsigned int nat_ofs = NAT_BLOCK_OFFSET(nid);
+	unsigned int nid_ofs = nid - START_NID(nid);
+
+	if (!test_bit_le(nat_ofs, nm_i->nat_block_bitmap))
+		return;
+
+	if (set) {
+		if (test_bit_le(nid_ofs, nm_i->free_nid_bitmap[nat_ofs]))
+			return;
+		__set_bit_le(nid_ofs, nm_i->free_nid_bitmap[nat_ofs]);
+		nm_i->free_nid_count[nat_ofs]++;
+	} else {
+		if (!test_bit_le(nid_ofs, nm_i->free_nid_bitmap[nat_ofs]))
+			return;
+		__clear_bit_le(nid_ofs, nm_i->free_nid_bitmap[nat_ofs]);
+		if (!build)
+			nm_i->free_nid_count[nat_ofs]--;
+	}
+}
+
+/* return if the nid is recognized as free */
+static bool add_free_nid(struct f2fs_sb_info *sbi,
+				nid_t nid, bool build, bool update)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	struct free_nid *i, *e;
+	struct nat_entry *ne;
+	int err = -EINVAL;
+	bool ret = false;
+
+	/* 0 nid should not be used */
+	if (unlikely(nid == 0))
+		return false;
+
+	i = f2fs_kmem_cache_alloc(free_nid_slab, GFP_NOFS);
+	i->nid = nid;
+	i->state = FREE_NID;
+
+	radix_tree_preload(GFP_NOFS | __GFP_NOFAIL);
+
+	spin_lock(&nm_i->nid_list_lock);
+
+	if (build) {
+		/*
+		 *   Thread A             Thread B
+		 *  - f2fs_create
+		 *   - f2fs_new_inode
+		 *    - alloc_nid
+		 *     - __insert_nid_to_list(PREALLOC_NID)
+		 *                     - f2fs_balance_fs_bg
+		 *                      - build_free_nids
+		 *                       - __build_free_nids
+		 *                        - scan_nat_page
+		 *                         - add_free_nid
+		 *                          - __lookup_nat_cache
+		 *  - f2fs_add_link
+		 *   - init_inode_metadata
+		 *    - new_inode_page
+		 *     - new_node_page
+		 *      - set_node_addr
+		 *  - alloc_nid_done
+		 *   - __remove_nid_from_list(PREALLOC_NID)
+		 *                         - __insert_nid_to_list(FREE_NID)
+		 */
+		ne = __lookup_nat_cache(nm_i, nid);
+		if (ne && (!get_nat_flag(ne, IS_CHECKPOINTED) ||
+				nat_get_blkaddr(ne) != NULL_ADDR))
+			goto err_out;
+
+		e = __lookup_free_nid_list(nm_i, nid);
+		if (e) {
+			if (e->state == FREE_NID)
+				ret = true;
+			goto err_out;
+		}
+	}
+	ret = true;
+	err = __insert_free_nid(sbi, i, FREE_NID);
+err_out:
+	if (update) {
+		update_free_nid_bitmap(sbi, nid, ret, build);
+		if (!build)
+			nm_i->available_nids++;
+	}
+	spin_unlock(&nm_i->nid_list_lock);
+	radix_tree_preload_end();
+
+	if (err)
+		kmem_cache_free(free_nid_slab, i);
+	return ret;
+}
+
+static void remove_free_nid(struct f2fs_sb_info *sbi, nid_t nid)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	struct free_nid *i;
+	bool need_free = false;
+
+	spin_lock(&nm_i->nid_list_lock);
+	i = __lookup_free_nid_list(nm_i, nid);
+	if (i && i->state == FREE_NID) {
+		__remove_free_nid(sbi, i, FREE_NID);
+		need_free = true;
+	}
+	spin_unlock(&nm_i->nid_list_lock);
+
+	if (need_free)
+		kmem_cache_free(free_nid_slab, i);
+}
+
+static void scan_nat_page(struct f2fs_sb_info *sbi,
+			struct page *nat_page, nid_t start_nid)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	struct f2fs_nat_block *nat_blk = page_address(nat_page);
+	block_t blk_addr;
+	unsigned int nat_ofs = NAT_BLOCK_OFFSET(start_nid);
+	int i;
+
+	__set_bit_le(nat_ofs, nm_i->nat_block_bitmap);
+
+	i = start_nid % NAT_ENTRY_PER_BLOCK;
+
+	for (; i < NAT_ENTRY_PER_BLOCK; i++, start_nid++) {
+		if (unlikely(start_nid >= nm_i->max_nid))
+			break;
+
+		blk_addr = le32_to_cpu(nat_blk->entries[i].block_addr);
+		f2fs_bug_on(sbi, blk_addr == NEW_ADDR);
+		if (blk_addr == NULL_ADDR) {
+			add_free_nid(sbi, start_nid, true, true);
+		} else {
+			spin_lock(&NM_I(sbi)->nid_list_lock);
+			update_free_nid_bitmap(sbi, start_nid, false, true);
+			spin_unlock(&NM_I(sbi)->nid_list_lock);
+		}
+	}
+}
+
+static void scan_curseg_cache(struct f2fs_sb_info *sbi)
+{
+	struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_HOT_DATA);
+	struct f2fs_journal *journal = curseg->journal;
+	int i;
+
+	down_read(&curseg->journal_rwsem);
+	for (i = 0; i < nats_in_cursum(journal); i++) {
+		block_t addr;
+		nid_t nid;
+
+		addr = le32_to_cpu(nat_in_journal(journal, i).block_addr);
+		nid = le32_to_cpu(nid_in_journal(journal, i));
+		if (addr == NULL_ADDR)
+			add_free_nid(sbi, nid, true, false);
+		else
+			remove_free_nid(sbi, nid);
+	}
+	up_read(&curseg->journal_rwsem);
+}
+
+static void scan_free_nid_bits(struct f2fs_sb_info *sbi)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	unsigned int i, idx;
+	nid_t nid;
+
+	down_read(&nm_i->nat_tree_lock);
+
+	for (i = 0; i < nm_i->nat_blocks; i++) {
+		if (!test_bit_le(i, nm_i->nat_block_bitmap))
+			continue;
+		if (!nm_i->free_nid_count[i])
+			continue;
+		for (idx = 0; idx < NAT_ENTRY_PER_BLOCK; idx++) {
+			idx = find_next_bit_le(nm_i->free_nid_bitmap[i],
+						NAT_ENTRY_PER_BLOCK, idx);
+			if (idx >= NAT_ENTRY_PER_BLOCK)
+				break;
+
+			nid = i * NAT_ENTRY_PER_BLOCK + idx;
+			add_free_nid(sbi, nid, true, false);
+
+			if (nm_i->nid_cnt[FREE_NID] >= MAX_FREE_NIDS)
+				goto out;
+		}
+	}
+out:
+	scan_curseg_cache(sbi);
+
+	up_read(&nm_i->nat_tree_lock);
+}
+
+static void __build_free_nids(struct f2fs_sb_info *sbi, bool sync, bool mount)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	int i = 0;
+	nid_t nid = nm_i->next_scan_nid;
+
+	if (unlikely(nid >= nm_i->max_nid))
+		nid = 0;
+
+	if (unlikely(nid % NAT_ENTRY_PER_BLOCK))
+		nid = NAT_BLOCK_OFFSET(nid) * NAT_ENTRY_PER_BLOCK;
+
+	/* Enough entries */
+	if (nm_i->nid_cnt[FREE_NID] >= NAT_ENTRY_PER_BLOCK)
+		return;
+
+	if (!sync && !available_free_memory(sbi, FREE_NIDS))
+		return;
+
+	if (!mount) {
+		/* try to find free nids in free_nid_bitmap */
+		scan_free_nid_bits(sbi);
+
+		if (nm_i->nid_cnt[FREE_NID] >= NAT_ENTRY_PER_BLOCK)
+			return;
+	}
+
+	/* readahead nat pages to be scanned */
+	ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nid), FREE_NID_PAGES,
+							META_NAT, true);
+
+	down_read(&nm_i->nat_tree_lock);
+
+	while (1) {
+		if (!test_bit_le(NAT_BLOCK_OFFSET(nid),
+						nm_i->nat_block_bitmap)) {
+			struct page *page = get_current_nat_page(sbi, nid);
+
+			scan_nat_page(sbi, page, nid);
+			f2fs_put_page(page, 1);
+		}
+
+		nid += (NAT_ENTRY_PER_BLOCK - (nid % NAT_ENTRY_PER_BLOCK));
+		if (unlikely(nid >= nm_i->max_nid))
+			nid = 0;
+
+		if (++i >= FREE_NID_PAGES)
+			break;
+	}
+
+	/* go to the next free nat pages to find free nids abundantly */
+	nm_i->next_scan_nid = nid;
+
+	/* find free nids from current sum_pages */
+	scan_curseg_cache(sbi);
+
+	up_read(&nm_i->nat_tree_lock);
+
+	ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nm_i->next_scan_nid),
+					nm_i->ra_nid_pages, META_NAT, false);
+}
+
+void build_free_nids(struct f2fs_sb_info *sbi, bool sync, bool mount)
+{
+	mutex_lock(&NM_I(sbi)->build_lock);
+	__build_free_nids(sbi, sync, mount);
+	mutex_unlock(&NM_I(sbi)->build_lock);
+}
+
+/*
+ * If this function returns success, caller can obtain a new nid
+ * from second parameter of this function.
+ * The returned nid could be used ino as well as nid when inode is created.
+ */
+bool alloc_nid(struct f2fs_sb_info *sbi, nid_t *nid)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	struct free_nid *i = NULL;
+retry:
+#ifdef CONFIG_F2FS_FAULT_INJECTION
+	if (time_to_inject(sbi, FAULT_ALLOC_NID)) {
+		f2fs_show_injection_info(FAULT_ALLOC_NID);
+		return false;
+	}
+#endif
+	spin_lock(&nm_i->nid_list_lock);
+
+	if (unlikely(nm_i->available_nids == 0)) {
+		spin_unlock(&nm_i->nid_list_lock);
+		return false;
+	}
+
+	/* We should not use stale free nids created by build_free_nids */
+	if (nm_i->nid_cnt[FREE_NID] && !on_build_free_nids(nm_i)) {
+		f2fs_bug_on(sbi, list_empty(&nm_i->free_nid_list));
+		i = list_first_entry(&nm_i->free_nid_list,
+					struct free_nid, list);
+		*nid = i->nid;
+
+		__move_free_nid(sbi, i, FREE_NID, PREALLOC_NID);
+		nm_i->available_nids--;
+
+		update_free_nid_bitmap(sbi, *nid, false, false);
+
+		spin_unlock(&nm_i->nid_list_lock);
+		return true;
+	}
+	spin_unlock(&nm_i->nid_list_lock);
+
+	/* Let's scan nat pages and its caches to get free nids */
+	build_free_nids(sbi, true, false);
+	goto retry;
+}
+
+/*
+ * alloc_nid() should be called prior to this function.
+ */
+void alloc_nid_done(struct f2fs_sb_info *sbi, nid_t nid)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	struct free_nid *i;
+
+	spin_lock(&nm_i->nid_list_lock);
+	i = __lookup_free_nid_list(nm_i, nid);
+	f2fs_bug_on(sbi, !i);
+	__remove_free_nid(sbi, i, PREALLOC_NID);
+	spin_unlock(&nm_i->nid_list_lock);
+
+	kmem_cache_free(free_nid_slab, i);
+}
+
+/*
+ * alloc_nid() should be called prior to this function.
+ */
+void alloc_nid_failed(struct f2fs_sb_info *sbi, nid_t nid)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	struct free_nid *i;
+	bool need_free = false;
+
+	if (!nid)
+		return;
+
+	spin_lock(&nm_i->nid_list_lock);
+	i = __lookup_free_nid_list(nm_i, nid);
+	f2fs_bug_on(sbi, !i);
+
+	if (!available_free_memory(sbi, FREE_NIDS)) {
+		__remove_free_nid(sbi, i, PREALLOC_NID);
+		need_free = true;
+	} else {
+		__move_free_nid(sbi, i, PREALLOC_NID, FREE_NID);
+	}
+
+	nm_i->available_nids++;
+
+	update_free_nid_bitmap(sbi, nid, true, false);
+
+	spin_unlock(&nm_i->nid_list_lock);
+
+	if (need_free)
+		kmem_cache_free(free_nid_slab, i);
+}
+
+int try_to_free_nids(struct f2fs_sb_info *sbi, int nr_shrink)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	struct free_nid *i, *next;
+	int nr = nr_shrink;
+
+	if (nm_i->nid_cnt[FREE_NID] <= MAX_FREE_NIDS)
+		return 0;
+
+	if (!mutex_trylock(&nm_i->build_lock))
+		return 0;
+
+	spin_lock(&nm_i->nid_list_lock);
+	list_for_each_entry_safe(i, next, &nm_i->free_nid_list, list) {
+		if (nr_shrink <= 0 ||
+				nm_i->nid_cnt[FREE_NID] <= MAX_FREE_NIDS)
+			break;
+
+		__remove_free_nid(sbi, i, FREE_NID);
+		kmem_cache_free(free_nid_slab, i);
+		nr_shrink--;
+	}
+	spin_unlock(&nm_i->nid_list_lock);
+	mutex_unlock(&nm_i->build_lock);
+
+	return nr - nr_shrink;
+}
+
+void recover_inline_xattr(struct inode *inode, struct page *page)
+{
+	void *src_addr, *dst_addr;
+	size_t inline_size;
+	struct page *ipage;
+	struct f2fs_inode *ri;
+
+	ipage = get_node_page(F2FS_I_SB(inode), inode->i_ino);
+	f2fs_bug_on(F2FS_I_SB(inode), IS_ERR(ipage));
+
+	ri = F2FS_INODE(page);
+	if (ri->i_inline & F2FS_INLINE_XATTR) {
+		set_inode_flag(inode, FI_INLINE_XATTR);
+	} else {
+		clear_inode_flag(inode, FI_INLINE_XATTR);
+		goto update_inode;
+	}
+
+	dst_addr = inline_xattr_addr(inode, ipage);
+	src_addr = inline_xattr_addr(inode, page);
+	inline_size = inline_xattr_size(inode);
+
+	f2fs_wait_on_page_writeback(ipage, NODE, true);
+	memcpy(dst_addr, src_addr, inline_size);
+update_inode:
+	update_inode(inode, ipage);
+	f2fs_put_page(ipage, 1);
+}
+
+int recover_xattr_data(struct inode *inode, struct page *page)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	nid_t prev_xnid = F2FS_I(inode)->i_xattr_nid;
+	nid_t new_xnid;
+	struct dnode_of_data dn;
+	struct node_info ni;
+	struct page *xpage;
+
+	if (!prev_xnid)
+		goto recover_xnid;
+
+	/* 1: invalidate the previous xattr nid */
+	get_node_info(sbi, prev_xnid, &ni);
+	invalidate_blocks(sbi, ni.blk_addr);
+	dec_valid_node_count(sbi, inode, false);
+	set_node_addr(sbi, &ni, NULL_ADDR, false);
+
+recover_xnid:
+	/* 2: update xattr nid in inode */
+	if (!alloc_nid(sbi, &new_xnid))
+		return -ENOSPC;
+
+	set_new_dnode(&dn, inode, NULL, NULL, new_xnid);
+	xpage = new_node_page(&dn, XATTR_NODE_OFFSET);
+	if (IS_ERR(xpage)) {
+		alloc_nid_failed(sbi, new_xnid);
+		return PTR_ERR(xpage);
+	}
+
+	alloc_nid_done(sbi, new_xnid);
+	update_inode_page(inode);
+
+	/* 3: update and set xattr node page dirty */
+	memcpy(F2FS_NODE(xpage), F2FS_NODE(page), VALID_XATTR_BLOCK_SIZE);
+
+	set_page_dirty(xpage);
+	f2fs_put_page(xpage, 1);
+
+	return 0;
+}
+
+int recover_inode_page(struct f2fs_sb_info *sbi, struct page *page)
+{
+	struct f2fs_inode *src, *dst;
+	nid_t ino = ino_of_node(page);
+	struct node_info old_ni, new_ni;
+	struct page *ipage;
+
+	get_node_info(sbi, ino, &old_ni);
+
+	if (unlikely(old_ni.blk_addr != NULL_ADDR))
+		return -EINVAL;
+retry:
+	ipage = f2fs_grab_cache_page(NODE_MAPPING(sbi), ino, false);
+	if (!ipage) {
+		congestion_wait(BLK_RW_ASYNC, HZ/50);
+		goto retry;
+	}
+
+	/* Should not use this inode from free nid list */
+	remove_free_nid(sbi, ino);
+
+	if (!PageUptodate(ipage))
+		SetPageUptodate(ipage);
+	fill_node_footer(ipage, ino, ino, 0, true);
+	set_cold_node(page, false);
+
+	src = F2FS_INODE(page);
+	dst = F2FS_INODE(ipage);
+
+	memcpy(dst, src, (unsigned long)&src->i_ext - (unsigned long)src);
+	dst->i_size = 0;
+	dst->i_blocks = cpu_to_le64(1);
+	dst->i_links = cpu_to_le32(1);
+	dst->i_xattr_nid = 0;
+	dst->i_inline = src->i_inline & (F2FS_INLINE_XATTR | F2FS_EXTRA_ATTR);
+	if (dst->i_inline & F2FS_EXTRA_ATTR) {
+		dst->i_extra_isize = src->i_extra_isize;
+
+		if (f2fs_sb_has_flexible_inline_xattr(sbi->sb) &&
+			F2FS_FITS_IN_INODE(src, le16_to_cpu(src->i_extra_isize),
+							i_inline_xattr_size))
+			dst->i_inline_xattr_size = src->i_inline_xattr_size;
+
+		if (f2fs_sb_has_project_quota(sbi->sb) &&
+			F2FS_FITS_IN_INODE(src, le16_to_cpu(src->i_extra_isize),
+								i_projid))
+			dst->i_projid = src->i_projid;
+	}
+
+	new_ni = old_ni;
+	new_ni.ino = ino;
+
+	if (unlikely(inc_valid_node_count(sbi, NULL, true)))
+		WARN_ON(1);
+	set_node_addr(sbi, &new_ni, NEW_ADDR, false);
+	inc_valid_inode_count(sbi);
+	set_page_dirty(ipage);
+	f2fs_put_page(ipage, 1);
+	return 0;
+}
+
+void restore_node_summary(struct f2fs_sb_info *sbi,
+			unsigned int segno, struct f2fs_summary_block *sum)
+{
+	struct f2fs_node *rn;
+	struct f2fs_summary *sum_entry;
+	block_t addr;
+	int i, idx, last_offset, nrpages;
+
+	/* scan the node segment */
+	last_offset = sbi->blocks_per_seg;
+	addr = START_BLOCK(sbi, segno);
+	sum_entry = &sum->entries[0];
+
+	for (i = 0; i < last_offset; i += nrpages, addr += nrpages) {
+		nrpages = min(last_offset - i, BIO_MAX_PAGES);
+
+		/* readahead node pages */
+		ra_meta_pages(sbi, addr, nrpages, META_POR, true);
+
+		for (idx = addr; idx < addr + nrpages; idx++) {
+			struct page *page = get_tmp_page(sbi, idx);
+
+			rn = F2FS_NODE(page);
+			sum_entry->nid = rn->footer.nid;
+			sum_entry->version = 0;
+			sum_entry->ofs_in_node = 0;
+			sum_entry++;
+			f2fs_put_page(page, 1);
+		}
+
+		invalidate_mapping_pages(META_MAPPING(sbi), addr,
+							addr + nrpages);
+	}
+}
+
+static void remove_nats_in_journal(struct f2fs_sb_info *sbi)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_HOT_DATA);
+	struct f2fs_journal *journal = curseg->journal;
+	int i;
+
+	down_write(&curseg->journal_rwsem);
+	for (i = 0; i < nats_in_cursum(journal); i++) {
+		struct nat_entry *ne;
+		struct f2fs_nat_entry raw_ne;
+		nid_t nid = le32_to_cpu(nid_in_journal(journal, i));
+
+		raw_ne = nat_in_journal(journal, i);
+
+		ne = __lookup_nat_cache(nm_i, nid);
+		if (!ne) {
+			ne = __alloc_nat_entry(nid, true);
+			__init_nat_entry(nm_i, ne, &raw_ne, true);
+		}
+
+		/*
+		 * if a free nat in journal has not been used after last
+		 * checkpoint, we should remove it from available nids,
+		 * since later we will add it again.
+		 */
+		if (!get_nat_flag(ne, IS_DIRTY) &&
+				le32_to_cpu(raw_ne.block_addr) == NULL_ADDR) {
+			spin_lock(&nm_i->nid_list_lock);
+			nm_i->available_nids--;
+			spin_unlock(&nm_i->nid_list_lock);
+		}
+
+		__set_nat_cache_dirty(nm_i, ne);
+	}
+	update_nats_in_cursum(journal, -i);
+	up_write(&curseg->journal_rwsem);
+}
+
+static void __adjust_nat_entry_set(struct nat_entry_set *nes,
+						struct list_head *head, int max)
+{
+	struct nat_entry_set *cur;
+
+	if (nes->entry_cnt >= max)
+		goto add_out;
+
+	list_for_each_entry(cur, head, set_list) {
+		if (cur->entry_cnt >= nes->entry_cnt) {
+			list_add(&nes->set_list, cur->set_list.prev);
+			return;
+		}
+	}
+add_out:
+	list_add_tail(&nes->set_list, head);
+}
+
+static void __update_nat_bits(struct f2fs_sb_info *sbi, nid_t start_nid,
+						struct page *page)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	unsigned int nat_index = start_nid / NAT_ENTRY_PER_BLOCK;
+	struct f2fs_nat_block *nat_blk = page_address(page);
+	int valid = 0;
+	int i = 0;
+
+	if (!enabled_nat_bits(sbi, NULL))
+		return;
+
+	if (nat_index == 0) {
+		valid = 1;
+		i = 1;
+	}
+	for (; i < NAT_ENTRY_PER_BLOCK; i++) {
+		if (nat_blk->entries[i].block_addr != NULL_ADDR)
+			valid++;
+	}
+	if (valid == 0) {
+		__set_bit_le(nat_index, nm_i->empty_nat_bits);
+		__clear_bit_le(nat_index, nm_i->full_nat_bits);
+		return;
+	}
+
+	__clear_bit_le(nat_index, nm_i->empty_nat_bits);
+	if (valid == NAT_ENTRY_PER_BLOCK)
+		__set_bit_le(nat_index, nm_i->full_nat_bits);
+	else
+		__clear_bit_le(nat_index, nm_i->full_nat_bits);
+}
+
+static void __flush_nat_entry_set(struct f2fs_sb_info *sbi,
+		struct nat_entry_set *set, struct cp_control *cpc)
+{
+	struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_HOT_DATA);
+	struct f2fs_journal *journal = curseg->journal;
+	nid_t start_nid = set->set * NAT_ENTRY_PER_BLOCK;
+	bool to_journal = true;
+	struct f2fs_nat_block *nat_blk;
+	struct nat_entry *ne, *cur;
+	struct page *page = NULL;
+
+	/*
+	 * there are two steps to flush nat entries:
+	 * #1, flush nat entries to journal in current hot data summary block.
+	 * #2, flush nat entries to nat page.
+	 */
+	if (enabled_nat_bits(sbi, cpc) ||
+		!__has_cursum_space(journal, set->entry_cnt, NAT_JOURNAL))
+		to_journal = false;
+
+	if (to_journal) {
+		down_write(&curseg->journal_rwsem);
+	} else {
+		page = get_next_nat_page(sbi, start_nid);
+		nat_blk = page_address(page);
+		f2fs_bug_on(sbi, !nat_blk);
+	}
+
+	/* flush dirty nats in nat entry set */
+	list_for_each_entry_safe(ne, cur, &set->entry_list, list) {
+		struct f2fs_nat_entry *raw_ne;
+		nid_t nid = nat_get_nid(ne);
+		int offset;
+
+		f2fs_bug_on(sbi, nat_get_blkaddr(ne) == NEW_ADDR);
+
+		if (to_journal) {
+			offset = lookup_journal_in_cursum(journal,
+							NAT_JOURNAL, nid, 1);
+			f2fs_bug_on(sbi, offset < 0);
+			raw_ne = &nat_in_journal(journal, offset);
+			nid_in_journal(journal, offset) = cpu_to_le32(nid);
+		} else {
+			raw_ne = &nat_blk->entries[nid - start_nid];
+		}
+		raw_nat_from_node_info(raw_ne, &ne->ni);
+		nat_reset_flag(ne);
+		__clear_nat_cache_dirty(NM_I(sbi), set, ne);
+		if (nat_get_blkaddr(ne) == NULL_ADDR) {
+			add_free_nid(sbi, nid, false, true);
+		} else {
+			spin_lock(&NM_I(sbi)->nid_list_lock);
+			update_free_nid_bitmap(sbi, nid, false, false);
+			spin_unlock(&NM_I(sbi)->nid_list_lock);
+		}
+	}
+
+	if (to_journal) {
+		up_write(&curseg->journal_rwsem);
+	} else {
+		__update_nat_bits(sbi, start_nid, page);
+		f2fs_put_page(page, 1);
+	}
+
+	/* Allow dirty nats by node block allocation in write_begin */
+	if (!set->entry_cnt) {
+		radix_tree_delete(&NM_I(sbi)->nat_set_root, set->set);
+		kmem_cache_free(nat_entry_set_slab, set);
+	}
+}
+
+/*
+ * This function is called during the checkpointing process.
+ */
+void flush_nat_entries(struct f2fs_sb_info *sbi, struct cp_control *cpc)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_HOT_DATA);
+	struct f2fs_journal *journal = curseg->journal;
+	struct nat_entry_set *setvec[SETVEC_SIZE];
+	struct nat_entry_set *set, *tmp;
+	unsigned int found;
+	nid_t set_idx = 0;
+	LIST_HEAD(sets);
+
+	if (!nm_i->dirty_nat_cnt)
+		return;
+
+	down_write(&nm_i->nat_tree_lock);
+
+	/*
+	 * if there are no enough space in journal to store dirty nat
+	 * entries, remove all entries from journal and merge them
+	 * into nat entry set.
+	 */
+	if (enabled_nat_bits(sbi, cpc) ||
+		!__has_cursum_space(journal, nm_i->dirty_nat_cnt, NAT_JOURNAL))
+		remove_nats_in_journal(sbi);
+
+	while ((found = __gang_lookup_nat_set(nm_i,
+					set_idx, SETVEC_SIZE, setvec))) {
+		unsigned idx;
+		set_idx = setvec[found - 1]->set + 1;
+		for (idx = 0; idx < found; idx++)
+			__adjust_nat_entry_set(setvec[idx], &sets,
+						MAX_NAT_JENTRIES(journal));
+	}
+
+	/* flush dirty nats in nat entry set */
+	list_for_each_entry_safe(set, tmp, &sets, set_list)
+		__flush_nat_entry_set(sbi, set, cpc);
+
+	up_write(&nm_i->nat_tree_lock);
+	/* Allow dirty nats by node block allocation in write_begin */
+}
+
+static int __get_nat_bitmaps(struct f2fs_sb_info *sbi)
+{
+	struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	unsigned int nat_bits_bytes = nm_i->nat_blocks / BITS_PER_BYTE;
+	unsigned int i;
+	__u64 cp_ver = cur_cp_version(ckpt);
+	block_t nat_bits_addr;
+
+	if (!enabled_nat_bits(sbi, NULL))
+		return 0;
+
+	nm_i->nat_bits_blocks = F2FS_BLK_ALIGN((nat_bits_bytes << 1) + 8);
+	nm_i->nat_bits = f2fs_kzalloc(sbi,
+			nm_i->nat_bits_blocks << F2FS_BLKSIZE_BITS, GFP_KERNEL);
+	if (!nm_i->nat_bits)
+		return -ENOMEM;
+
+	nat_bits_addr = __start_cp_addr(sbi) + sbi->blocks_per_seg -
+						nm_i->nat_bits_blocks;
+	for (i = 0; i < nm_i->nat_bits_blocks; i++) {
+		struct page *page = get_meta_page(sbi, nat_bits_addr++);
+
+		memcpy(nm_i->nat_bits + (i << F2FS_BLKSIZE_BITS),
+					page_address(page), F2FS_BLKSIZE);
+		f2fs_put_page(page, 1);
+	}
+
+	cp_ver |= (cur_cp_crc(ckpt) << 32);
+	if (cpu_to_le64(cp_ver) != *(__le64 *)nm_i->nat_bits) {
+		disable_nat_bits(sbi, true);
+		return 0;
+	}
+
+	nm_i->full_nat_bits = nm_i->nat_bits + 8;
+	nm_i->empty_nat_bits = nm_i->full_nat_bits + nat_bits_bytes;
+
+	f2fs_msg(sbi->sb, KERN_NOTICE, "Found nat_bits in checkpoint");
+	return 0;
+}
+
+static inline void load_free_nid_bitmap(struct f2fs_sb_info *sbi)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	unsigned int i = 0;
+	nid_t nid, last_nid;
+
+	if (!enabled_nat_bits(sbi, NULL))
+		return;
+
+	for (i = 0; i < nm_i->nat_blocks; i++) {
+		i = find_next_bit_le(nm_i->empty_nat_bits, nm_i->nat_blocks, i);
+		if (i >= nm_i->nat_blocks)
+			break;
+
+		__set_bit_le(i, nm_i->nat_block_bitmap);
+
+		nid = i * NAT_ENTRY_PER_BLOCK;
+		last_nid = nid + NAT_ENTRY_PER_BLOCK;
+
+		spin_lock(&NM_I(sbi)->nid_list_lock);
+		for (; nid < last_nid; nid++)
+			update_free_nid_bitmap(sbi, nid, true, true);
+		spin_unlock(&NM_I(sbi)->nid_list_lock);
+	}
+
+	for (i = 0; i < nm_i->nat_blocks; i++) {
+		i = find_next_bit_le(nm_i->full_nat_bits, nm_i->nat_blocks, i);
+		if (i >= nm_i->nat_blocks)
+			break;
+
+		__set_bit_le(i, nm_i->nat_block_bitmap);
+	}
+}
+
+static int init_node_manager(struct f2fs_sb_info *sbi)
+{
+	struct f2fs_super_block *sb_raw = F2FS_RAW_SUPER(sbi);
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	unsigned char *version_bitmap;
+	unsigned int nat_segs;
+	int err;
+
+	nm_i->nat_blkaddr = le32_to_cpu(sb_raw->nat_blkaddr);
+
+	/* segment_count_nat includes pair segment so divide to 2. */
+	nat_segs = le32_to_cpu(sb_raw->segment_count_nat) >> 1;
+	nm_i->nat_blocks = nat_segs << le32_to_cpu(sb_raw->log_blocks_per_seg);
+	nm_i->max_nid = NAT_ENTRY_PER_BLOCK * nm_i->nat_blocks;
+
+	/* not used nids: 0, node, meta, (and root counted as valid node) */
+	nm_i->available_nids = nm_i->max_nid - sbi->total_valid_node_count -
+				sbi->nquota_files - F2FS_RESERVED_NODE_NUM;
+	nm_i->nid_cnt[FREE_NID] = 0;
+	nm_i->nid_cnt[PREALLOC_NID] = 0;
+	nm_i->nat_cnt = 0;
+	nm_i->ram_thresh = DEF_RAM_THRESHOLD;
+	nm_i->ra_nid_pages = DEF_RA_NID_PAGES;
+	nm_i->dirty_nats_ratio = DEF_DIRTY_NAT_RATIO_THRESHOLD;
+
+	INIT_RADIX_TREE(&nm_i->free_nid_root, GFP_ATOMIC);
+	INIT_LIST_HEAD(&nm_i->free_nid_list);
+	INIT_RADIX_TREE(&nm_i->nat_root, GFP_NOIO);
+	INIT_RADIX_TREE(&nm_i->nat_set_root, GFP_NOIO);
+	INIT_LIST_HEAD(&nm_i->nat_entries);
+
+	mutex_init(&nm_i->build_lock);
+	spin_lock_init(&nm_i->nid_list_lock);
+	init_rwsem(&nm_i->nat_tree_lock);
+
+	nm_i->next_scan_nid = le32_to_cpu(sbi->ckpt->next_free_nid);
+	nm_i->bitmap_size = __bitmap_size(sbi, NAT_BITMAP);
+	version_bitmap = __bitmap_ptr(sbi, NAT_BITMAP);
+	if (!version_bitmap)
+		return -EFAULT;
+
+	nm_i->nat_bitmap = kmemdup(version_bitmap, nm_i->bitmap_size,
+					GFP_KERNEL);
+	if (!nm_i->nat_bitmap)
+		return -ENOMEM;
+
+	err = __get_nat_bitmaps(sbi);
+	if (err)
+		return err;
+
+#ifdef CONFIG_F2FS_CHECK_FS
+	nm_i->nat_bitmap_mir = kmemdup(version_bitmap, nm_i->bitmap_size,
+					GFP_KERNEL);
+	if (!nm_i->nat_bitmap_mir)
+		return -ENOMEM;
+#endif
+
+	return 0;
+}
+
+static int init_free_nid_cache(struct f2fs_sb_info *sbi)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	int i;
+
+	nm_i->free_nid_bitmap = f2fs_kzalloc(sbi, nm_i->nat_blocks *
+				sizeof(unsigned char *), GFP_KERNEL);
+	if (!nm_i->free_nid_bitmap)
+		return -ENOMEM;
+
+	for (i = 0; i < nm_i->nat_blocks; i++) {
+		nm_i->free_nid_bitmap[i] = f2fs_kvzalloc(sbi,
+				NAT_ENTRY_BITMAP_SIZE_ALIGNED, GFP_KERNEL);
+		if (!nm_i->free_nid_bitmap)
+			return -ENOMEM;
+	}
+
+	nm_i->nat_block_bitmap = f2fs_kvzalloc(sbi, nm_i->nat_blocks / 8,
+								GFP_KERNEL);
+	if (!nm_i->nat_block_bitmap)
+		return -ENOMEM;
+
+	nm_i->free_nid_count = f2fs_kvzalloc(sbi, nm_i->nat_blocks *
+					sizeof(unsigned short), GFP_KERNEL);
+	if (!nm_i->free_nid_count)
+		return -ENOMEM;
+	return 0;
+}
+
+int build_node_manager(struct f2fs_sb_info *sbi)
+{
+	int err;
+
+	sbi->nm_info = f2fs_kzalloc(sbi, sizeof(struct f2fs_nm_info),
+							GFP_KERNEL);
+	if (!sbi->nm_info)
+		return -ENOMEM;
+
+	err = init_node_manager(sbi);
+	if (err)
+		return err;
+
+	err = init_free_nid_cache(sbi);
+	if (err)
+		return err;
+
+	/* load free nid status from nat_bits table */
+	load_free_nid_bitmap(sbi);
+
+	build_free_nids(sbi, true, true);
+	return 0;
+}
+
+void destroy_node_manager(struct f2fs_sb_info *sbi)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	struct free_nid *i, *next_i;
+	struct nat_entry *natvec[NATVEC_SIZE];
+	struct nat_entry_set *setvec[SETVEC_SIZE];
+	nid_t nid = 0;
+	unsigned int found;
+
+	if (!nm_i)
+		return;
+
+	/* destroy free nid list */
+	spin_lock(&nm_i->nid_list_lock);
+	list_for_each_entry_safe(i, next_i, &nm_i->free_nid_list, list) {
+		__remove_free_nid(sbi, i, FREE_NID);
+		spin_unlock(&nm_i->nid_list_lock);
+		kmem_cache_free(free_nid_slab, i);
+		spin_lock(&nm_i->nid_list_lock);
+	}
+	f2fs_bug_on(sbi, nm_i->nid_cnt[FREE_NID]);
+	f2fs_bug_on(sbi, nm_i->nid_cnt[PREALLOC_NID]);
+	f2fs_bug_on(sbi, !list_empty(&nm_i->free_nid_list));
+	spin_unlock(&nm_i->nid_list_lock);
+
+	/* destroy nat cache */
+	down_write(&nm_i->nat_tree_lock);
+	while ((found = __gang_lookup_nat_cache(nm_i,
+					nid, NATVEC_SIZE, natvec))) {
+		unsigned idx;
+
+		nid = nat_get_nid(natvec[found - 1]) + 1;
+		for (idx = 0; idx < found; idx++)
+			__del_from_nat_cache(nm_i, natvec[idx]);
+	}
+	f2fs_bug_on(sbi, nm_i->nat_cnt);
+
+	/* destroy nat set cache */
+	nid = 0;
+	while ((found = __gang_lookup_nat_set(nm_i,
+					nid, SETVEC_SIZE, setvec))) {
+		unsigned idx;
+
+		nid = setvec[found - 1]->set + 1;
+		for (idx = 0; idx < found; idx++) {
+			/* entry_cnt is not zero, when cp_error was occurred */
+			f2fs_bug_on(sbi, !list_empty(&setvec[idx]->entry_list));
+			radix_tree_delete(&nm_i->nat_set_root, setvec[idx]->set);
+			kmem_cache_free(nat_entry_set_slab, setvec[idx]);
+		}
+	}
+	up_write(&nm_i->nat_tree_lock);
+
+	kvfree(nm_i->nat_block_bitmap);
+	if (nm_i->free_nid_bitmap) {
+		int i;
+
+		for (i = 0; i < nm_i->nat_blocks; i++)
+			kvfree(nm_i->free_nid_bitmap[i]);
+		kfree(nm_i->free_nid_bitmap);
+	}
+	kvfree(nm_i->free_nid_count);
+
+	kfree(nm_i->nat_bitmap);
+	kfree(nm_i->nat_bits);
+#ifdef CONFIG_F2FS_CHECK_FS
+	kfree(nm_i->nat_bitmap_mir);
+#endif
+	sbi->nm_info = NULL;
+	kfree(nm_i);
+}
+
+int __init create_node_manager_caches(void)
+{
+	nat_entry_slab = f2fs_kmem_cache_create("nat_entry",
+			sizeof(struct nat_entry));
+	if (!nat_entry_slab)
+		goto fail;
+
+	free_nid_slab = f2fs_kmem_cache_create("free_nid",
+			sizeof(struct free_nid));
+	if (!free_nid_slab)
+		goto destroy_nat_entry;
+
+	nat_entry_set_slab = f2fs_kmem_cache_create("nat_entry_set",
+			sizeof(struct nat_entry_set));
+	if (!nat_entry_set_slab)
+		goto destroy_free_nid;
+	return 0;
+
+destroy_free_nid:
+	kmem_cache_destroy(free_nid_slab);
+destroy_nat_entry:
+	kmem_cache_destroy(nat_entry_slab);
+fail:
+	return -ENOMEM;
+}
+
+void destroy_node_manager_caches(void)
+{
+	kmem_cache_destroy(nat_entry_set_slab);
+	kmem_cache_destroy(free_nid_slab);
+	kmem_cache_destroy(nat_entry_slab);
+}
diff --git a/src/kernel/linux/v4.14/fs/f2fs/node.h b/src/kernel/linux/v4.14/fs/f2fs/node.h
new file mode 100644
index 0000000..b95e49e
--- /dev/null
+++ b/src/kernel/linux/v4.14/fs/f2fs/node.h
@@ -0,0 +1,449 @@
+/*
+ * fs/f2fs/node.h
+ *
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ *             http://www.samsung.com/
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+/* start node id of a node block dedicated to the given node id */
+#define	START_NID(nid) (((nid) / NAT_ENTRY_PER_BLOCK) * NAT_ENTRY_PER_BLOCK)
+
+/* node block offset on the NAT area dedicated to the given start node id */
+#define	NAT_BLOCK_OFFSET(start_nid) ((start_nid) / NAT_ENTRY_PER_BLOCK)
+
+/* # of pages to perform synchronous readahead before building free nids */
+#define FREE_NID_PAGES	8
+#define MAX_FREE_NIDS	(NAT_ENTRY_PER_BLOCK * FREE_NID_PAGES)
+
+#define DEF_RA_NID_PAGES	0	/* # of nid pages to be readaheaded */
+
+/* maximum readahead size for node during getting data blocks */
+#define MAX_RA_NODE		128
+
+/* control the memory footprint threshold (10MB per 1GB ram) */
+#define DEF_RAM_THRESHOLD	1
+
+/* control dirty nats ratio threshold (default: 10% over max nid count) */
+#define DEF_DIRTY_NAT_RATIO_THRESHOLD		10
+/* control total # of nats */
+#define DEF_NAT_CACHE_THRESHOLD			100000
+
+/* vector size for gang look-up from nat cache that consists of radix tree */
+#define NATVEC_SIZE	64
+#define SETVEC_SIZE	32
+
+/* return value for read_node_page */
+#define LOCKED_PAGE	1
+
+/* For flag in struct node_info */
+enum {
+	IS_CHECKPOINTED,	/* is it checkpointed before? */
+	HAS_FSYNCED_INODE,	/* is the inode fsynced before? */
+	HAS_LAST_FSYNC,		/* has the latest node fsync mark? */
+	IS_DIRTY,		/* this nat entry is dirty? */
+	IS_PREALLOC,		/* nat entry is preallocated */
+};
+
+/*
+ * For node information
+ */
+struct node_info {
+	nid_t nid;		/* node id */
+	nid_t ino;		/* inode number of the node's owner */
+	block_t	blk_addr;	/* block address of the node */
+	unsigned char version;	/* version of the node */
+	unsigned char flag;	/* for node information bits */
+};
+
+struct nat_entry {
+	struct list_head list;	/* for clean or dirty nat list */
+	struct node_info ni;	/* in-memory node information */
+};
+
+#define nat_get_nid(nat)		((nat)->ni.nid)
+#define nat_set_nid(nat, n)		((nat)->ni.nid = (n))
+#define nat_get_blkaddr(nat)		((nat)->ni.blk_addr)
+#define nat_set_blkaddr(nat, b)		((nat)->ni.blk_addr = (b))
+#define nat_get_ino(nat)		((nat)->ni.ino)
+#define nat_set_ino(nat, i)		((nat)->ni.ino = (i))
+#define nat_get_version(nat)		((nat)->ni.version)
+#define nat_set_version(nat, v)		((nat)->ni.version = (v))
+
+#define inc_node_version(version)	(++(version))
+
+static inline void copy_node_info(struct node_info *dst,
+						struct node_info *src)
+{
+	dst->nid = src->nid;
+	dst->ino = src->ino;
+	dst->blk_addr = src->blk_addr;
+	dst->version = src->version;
+	/* should not copy flag here */
+}
+
+static inline void set_nat_flag(struct nat_entry *ne,
+				unsigned int type, bool set)
+{
+	unsigned char mask = 0x01 << type;
+	if (set)
+		ne->ni.flag |= mask;
+	else
+		ne->ni.flag &= ~mask;
+}
+
+static inline bool get_nat_flag(struct nat_entry *ne, unsigned int type)
+{
+	unsigned char mask = 0x01 << type;
+	return ne->ni.flag & mask;
+}
+
+static inline void nat_reset_flag(struct nat_entry *ne)
+{
+	/* these states can be set only after checkpoint was done */
+	set_nat_flag(ne, IS_CHECKPOINTED, true);
+	set_nat_flag(ne, HAS_FSYNCED_INODE, false);
+	set_nat_flag(ne, HAS_LAST_FSYNC, true);
+}
+
+static inline void node_info_from_raw_nat(struct node_info *ni,
+						struct f2fs_nat_entry *raw_ne)
+{
+	ni->ino = le32_to_cpu(raw_ne->ino);
+	ni->blk_addr = le32_to_cpu(raw_ne->block_addr);
+	ni->version = raw_ne->version;
+}
+
+static inline void raw_nat_from_node_info(struct f2fs_nat_entry *raw_ne,
+						struct node_info *ni)
+{
+	raw_ne->ino = cpu_to_le32(ni->ino);
+	raw_ne->block_addr = cpu_to_le32(ni->blk_addr);
+	raw_ne->version = ni->version;
+}
+
+static inline bool excess_dirty_nats(struct f2fs_sb_info *sbi)
+{
+	return NM_I(sbi)->dirty_nat_cnt >= NM_I(sbi)->max_nid *
+					NM_I(sbi)->dirty_nats_ratio / 100;
+}
+
+static inline bool excess_cached_nats(struct f2fs_sb_info *sbi)
+{
+	return NM_I(sbi)->nat_cnt >= DEF_NAT_CACHE_THRESHOLD;
+}
+
+enum mem_type {
+	FREE_NIDS,	/* indicates the free nid list */
+	NAT_ENTRIES,	/* indicates the cached nat entry */
+	DIRTY_DENTS,	/* indicates dirty dentry pages */
+	INO_ENTRIES,	/* indicates inode entries */
+	EXTENT_CACHE,	/* indicates extent cache */
+	INMEM_PAGES,	/* indicates inmemory pages */
+	BASE_CHECK,	/* check kernel status */
+};
+
+struct nat_entry_set {
+	struct list_head set_list;	/* link with other nat sets */
+	struct list_head entry_list;	/* link with dirty nat entries */
+	nid_t set;			/* set number*/
+	unsigned int entry_cnt;		/* the # of nat entries in set */
+};
+
+struct free_nid {
+	struct list_head list;	/* for free node id list */
+	nid_t nid;		/* node id */
+	int state;		/* in use or not: FREE_NID or PREALLOC_NID */
+};
+
+static inline void next_free_nid(struct f2fs_sb_info *sbi, nid_t *nid)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	struct free_nid *fnid;
+
+	spin_lock(&nm_i->nid_list_lock);
+	if (nm_i->nid_cnt[FREE_NID] <= 0) {
+		spin_unlock(&nm_i->nid_list_lock);
+		return;
+	}
+	fnid = list_first_entry(&nm_i->free_nid_list, struct free_nid, list);
+	*nid = fnid->nid;
+	spin_unlock(&nm_i->nid_list_lock);
+}
+
+/*
+ * inline functions
+ */
+static inline void get_nat_bitmap(struct f2fs_sb_info *sbi, void *addr)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+
+#ifdef CONFIG_F2FS_CHECK_FS
+	if (memcmp(nm_i->nat_bitmap, nm_i->nat_bitmap_mir,
+						nm_i->bitmap_size))
+		f2fs_bug_on(sbi, 1);
+#endif
+	memcpy(addr, nm_i->nat_bitmap, nm_i->bitmap_size);
+}
+
+static inline pgoff_t current_nat_addr(struct f2fs_sb_info *sbi, nid_t start)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	pgoff_t block_off;
+	pgoff_t block_addr;
+
+	/*
+	 * block_off = segment_off * 512 + off_in_segment
+	 * OLD = (segment_off * 512) * 2 + off_in_segment
+	 * NEW = 2 * (segment_off * 512 + off_in_segment) - off_in_segment
+	 */
+	block_off = NAT_BLOCK_OFFSET(start);
+
+	block_addr = (pgoff_t)(nm_i->nat_blkaddr +
+		(block_off << 1) -
+		(block_off & (sbi->blocks_per_seg - 1)));
+
+	if (f2fs_test_bit(block_off, nm_i->nat_bitmap))
+		block_addr += sbi->blocks_per_seg;
+
+	return block_addr;
+}
+
+static inline pgoff_t next_nat_addr(struct f2fs_sb_info *sbi,
+						pgoff_t block_addr)
+{
+	struct f2fs_nm_info *nm_i = NM_I(sbi);
+
+	block_addr -= nm_i->nat_blkaddr;
+	block_addr ^= 1 << sbi->log_blocks_per_seg;
+	return block_addr + nm_i->nat_blkaddr;
+}
+
+static inline void set_to_next_nat(struct f2fs_nm_info *nm_i, nid_t start_nid)
+{
+	unsigned int block_off = NAT_BLOCK_OFFSET(start_nid);
+
+	f2fs_change_bit(block_off, nm_i->nat_bitmap);
+#ifdef CONFIG_F2FS_CHECK_FS
+	f2fs_change_bit(block_off, nm_i->nat_bitmap_mir);
+#endif
+}
+
+static inline nid_t ino_of_node(struct page *node_page)
+{
+	struct f2fs_node *rn = F2FS_NODE(node_page);
+	return le32_to_cpu(rn->footer.ino);
+}
+
+static inline nid_t nid_of_node(struct page *node_page)
+{
+	struct f2fs_node *rn = F2FS_NODE(node_page);
+	return le32_to_cpu(rn->footer.nid);
+}
+
+static inline unsigned int ofs_of_node(struct page *node_page)
+{
+	struct f2fs_node *rn = F2FS_NODE(node_page);
+	unsigned flag = le32_to_cpu(rn->footer.flag);
+	return flag >> OFFSET_BIT_SHIFT;
+}
+
+static inline __u64 cpver_of_node(struct page *node_page)
+{
+	struct f2fs_node *rn = F2FS_NODE(node_page);
+	return le64_to_cpu(rn->footer.cp_ver);
+}
+
+static inline block_t next_blkaddr_of_node(struct page *node_page)
+{
+	struct f2fs_node *rn = F2FS_NODE(node_page);
+	return le32_to_cpu(rn->footer.next_blkaddr);
+}
+
+static inline void fill_node_footer(struct page *page, nid_t nid,
+				nid_t ino, unsigned int ofs, bool reset)
+{
+	struct f2fs_node *rn = F2FS_NODE(page);
+	unsigned int old_flag = 0;
+
+	if (reset)
+		memset(rn, 0, sizeof(*rn));
+	else
+		old_flag = le32_to_cpu(rn->footer.flag);
+
+	rn->footer.nid = cpu_to_le32(nid);
+	rn->footer.ino = cpu_to_le32(ino);
+
+	/* should remain old flag bits such as COLD_BIT_SHIFT */
+	rn->footer.flag = cpu_to_le32((ofs << OFFSET_BIT_SHIFT) |
+					(old_flag & OFFSET_BIT_MASK));
+}
+
+static inline void copy_node_footer(struct page *dst, struct page *src)
+{
+	struct f2fs_node *src_rn = F2FS_NODE(src);
+	struct f2fs_node *dst_rn = F2FS_NODE(dst);
+	memcpy(&dst_rn->footer, &src_rn->footer, sizeof(struct node_footer));
+}
+
+static inline void fill_node_footer_blkaddr(struct page *page, block_t blkaddr)
+{
+	struct f2fs_checkpoint *ckpt = F2FS_CKPT(F2FS_P_SB(page));
+	struct f2fs_node *rn = F2FS_NODE(page);
+	__u64 cp_ver = cur_cp_version(ckpt);
+
+	if (__is_set_ckpt_flags(ckpt, CP_CRC_RECOVERY_FLAG))
+		cp_ver |= (cur_cp_crc(ckpt) << 32);
+
+	rn->footer.cp_ver = cpu_to_le64(cp_ver);
+	rn->footer.next_blkaddr = cpu_to_le32(blkaddr);
+}
+
+static inline bool is_recoverable_dnode(struct page *page)
+{
+	struct f2fs_checkpoint *ckpt = F2FS_CKPT(F2FS_P_SB(page));
+	__u64 cp_ver = cur_cp_version(ckpt);
+
+	/* Don't care crc part, if fsck.f2fs sets it. */
+	if (__is_set_ckpt_flags(ckpt, CP_NOCRC_RECOVERY_FLAG))
+		return (cp_ver << 32) == (cpver_of_node(page) << 32);
+
+	if (__is_set_ckpt_flags(ckpt, CP_CRC_RECOVERY_FLAG))
+		cp_ver |= (cur_cp_crc(ckpt) << 32);
+
+	return cp_ver == cpver_of_node(page);
+}
+
+/*
+ * f2fs assigns the following node offsets described as (num).
+ * N = NIDS_PER_BLOCK
+ *
+ *  Inode block (0)
+ *    |- direct node (1)
+ *    |- direct node (2)
+ *    |- indirect node (3)
+ *    |            `- direct node (4 => 4 + N - 1)
+ *    |- indirect node (4 + N)
+ *    |            `- direct node (5 + N => 5 + 2N - 1)
+ *    `- double indirect node (5 + 2N)
+ *                 `- indirect node (6 + 2N)
+ *                       `- direct node
+ *                 ......
+ *                 `- indirect node ((6 + 2N) + x(N + 1))
+ *                       `- direct node
+ *                 ......
+ *                 `- indirect node ((6 + 2N) + (N - 1)(N + 1))
+ *                       `- direct node
+ */
+static inline bool IS_DNODE(struct page *node_page)
+{
+	unsigned int ofs = ofs_of_node(node_page);
+
+	if (f2fs_has_xattr_block(ofs))
+		return true;
+
+	if (ofs == 3 || ofs == 4 + NIDS_PER_BLOCK ||
+			ofs == 5 + 2 * NIDS_PER_BLOCK)
+		return false;
+	if (ofs >= 6 + 2 * NIDS_PER_BLOCK) {
+		ofs -= 6 + 2 * NIDS_PER_BLOCK;
+		if (!((long int)ofs % (NIDS_PER_BLOCK + 1)))
+			return false;
+	}
+	return true;
+}
+
+static inline int set_nid(struct page *p, int off, nid_t nid, bool i)
+{
+	struct f2fs_node *rn = F2FS_NODE(p);
+
+	f2fs_wait_on_page_writeback(p, NODE, true);
+
+	if (i)
+		rn->i.i_nid[off - NODE_DIR1_BLOCK] = cpu_to_le32(nid);
+	else
+		rn->in.nid[off] = cpu_to_le32(nid);
+	return set_page_dirty(p);
+}
+
+static inline nid_t get_nid(struct page *p, int off, bool i)
+{
+	struct f2fs_node *rn = F2FS_NODE(p);
+
+	if (i)
+		return le32_to_cpu(rn->i.i_nid[off - NODE_DIR1_BLOCK]);
+	return le32_to_cpu(rn->in.nid[off]);
+}
+
+/*
+ * Coldness identification:
+ *  - Mark cold files in f2fs_inode_info
+ *  - Mark cold node blocks in their node footer
+ *  - Mark cold data pages in page cache
+ */
+static inline int is_cold_data(struct page *page)
+{
+	return PageChecked(page);
+}
+
+static inline void set_cold_data(struct page *page)
+{
+	SetPageChecked(page);
+}
+
+static inline void clear_cold_data(struct page *page)
+{
+	ClearPageChecked(page);
+}
+
+static inline int is_node(struct page *page, int type)
+{
+	struct f2fs_node *rn = F2FS_NODE(page);
+	return le32_to_cpu(rn->footer.flag) & (1 << type);
+}
+
+#define is_cold_node(page)	is_node(page, COLD_BIT_SHIFT)
+#define is_fsync_dnode(page)	is_node(page, FSYNC_BIT_SHIFT)
+#define is_dent_dnode(page)	is_node(page, DENT_BIT_SHIFT)
+
+static inline int is_inline_node(struct page *page)
+{
+	return PageChecked(page);
+}
+
+static inline void set_inline_node(struct page *page)
+{
+	SetPageChecked(page);
+}
+
+static inline void clear_inline_node(struct page *page)
+{
+	ClearPageChecked(page);
+}
+
+static inline void set_cold_node(struct page *page, bool is_dir)
+{
+	struct f2fs_node *rn = F2FS_NODE(page);
+	unsigned int flag = le32_to_cpu(rn->footer.flag);
+
+	if (is_dir)
+		flag &= ~(0x1 << COLD_BIT_SHIFT);
+	else
+		flag |= (0x1 << COLD_BIT_SHIFT);
+	rn->footer.flag = cpu_to_le32(flag);
+}
+
+static inline void set_mark(struct page *page, int mark, int type)
+{
+	struct f2fs_node *rn = F2FS_NODE(page);
+	unsigned int flag = le32_to_cpu(rn->footer.flag);
+	if (mark)
+		flag |= (0x1 << type);
+	else
+		flag &= ~(0x1 << type);
+	rn->footer.flag = cpu_to_le32(flag);
+}
+#define set_dentry_mark(page, mark)	set_mark(page, mark, DENT_BIT_SHIFT)
+#define set_fsync_mark(page, mark)	set_mark(page, mark, FSYNC_BIT_SHIFT)
diff --git a/src/kernel/linux/v4.14/fs/f2fs/recovery.c b/src/kernel/linux/v4.14/fs/f2fs/recovery.c
new file mode 100644
index 0000000..eb666ac
--- /dev/null
+++ b/src/kernel/linux/v4.14/fs/f2fs/recovery.c
@@ -0,0 +1,716 @@
+/*
+ * fs/f2fs/recovery.c
+ *
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ *             http://www.samsung.com/
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/fs.h>
+#include <linux/f2fs_fs.h>
+#include "f2fs.h"
+#include "node.h"
+#include "segment.h"
+
+/*
+ * Roll forward recovery scenarios.
+ *
+ * [Term] F: fsync_mark, D: dentry_mark
+ *
+ * 1. inode(x) | CP | inode(x) | dnode(F)
+ * -> Update the latest inode(x).
+ *
+ * 2. inode(x) | CP | inode(F) | dnode(F)
+ * -> No problem.
+ *
+ * 3. inode(x) | CP | dnode(F) | inode(x)
+ * -> Recover to the latest dnode(F), and drop the last inode(x)
+ *
+ * 4. inode(x) | CP | dnode(F) | inode(F)
+ * -> No problem.
+ *
+ * 5. CP | inode(x) | dnode(F)
+ * -> The inode(DF) was missing. Should drop this dnode(F).
+ *
+ * 6. CP | inode(DF) | dnode(F)
+ * -> No problem.
+ *
+ * 7. CP | dnode(F) | inode(DF)
+ * -> If f2fs_iget fails, then goto next to find inode(DF).
+ *
+ * 8. CP | dnode(F) | inode(x)
+ * -> If f2fs_iget fails, then goto next to find inode(DF).
+ *    But it will fail due to no inode(DF).
+ */
+
+static struct kmem_cache *fsync_entry_slab;
+
+bool space_for_roll_forward(struct f2fs_sb_info *sbi)
+{
+	s64 nalloc = percpu_counter_sum_positive(&sbi->alloc_valid_block_count);
+
+	if (sbi->last_valid_block_count + nalloc > sbi->user_block_count)
+		return false;
+	return true;
+}
+
+static struct fsync_inode_entry *get_fsync_inode(struct list_head *head,
+								nid_t ino)
+{
+	struct fsync_inode_entry *entry;
+
+	list_for_each_entry(entry, head, list)
+		if (entry->inode->i_ino == ino)
+			return entry;
+
+	return NULL;
+}
+
+static struct fsync_inode_entry *add_fsync_inode(struct f2fs_sb_info *sbi,
+			struct list_head *head, nid_t ino, bool quota_inode)
+{
+	struct inode *inode;
+	struct fsync_inode_entry *entry;
+	int err;
+
+	inode = f2fs_iget_retry(sbi->sb, ino);
+	if (IS_ERR(inode))
+		return ERR_CAST(inode);
+
+	err = dquot_initialize(inode);
+	if (err)
+		goto err_out;
+
+	if (quota_inode) {
+		err = dquot_alloc_inode(inode);
+		if (err)
+			goto err_out;
+	}
+
+	entry = f2fs_kmem_cache_alloc(fsync_entry_slab, GFP_F2FS_ZERO);
+	entry->inode = inode;
+	list_add_tail(&entry->list, head);
+
+	return entry;
+err_out:
+	iput(inode);
+	return ERR_PTR(err);
+}
+
+static void del_fsync_inode(struct fsync_inode_entry *entry)
+{
+	iput(entry->inode);
+	list_del(&entry->list);
+	kmem_cache_free(fsync_entry_slab, entry);
+}
+
+static int recover_dentry(struct inode *inode, struct page *ipage,
+						struct list_head *dir_list)
+{
+	struct f2fs_inode *raw_inode = F2FS_INODE(ipage);
+	nid_t pino = le32_to_cpu(raw_inode->i_pino);
+	struct f2fs_dir_entry *de;
+	struct fscrypt_name fname;
+	struct page *page;
+	struct inode *dir, *einode;
+	struct fsync_inode_entry *entry;
+	int err = 0;
+	char *name;
+
+	entry = get_fsync_inode(dir_list, pino);
+	if (!entry) {
+		entry = add_fsync_inode(F2FS_I_SB(inode), dir_list,
+							pino, false);
+		if (IS_ERR(entry)) {
+			dir = ERR_CAST(entry);
+			err = PTR_ERR(entry);
+			goto out;
+		}
+	}
+
+	dir = entry->inode;
+
+	memset(&fname, 0, sizeof(struct fscrypt_name));
+	fname.disk_name.len = le32_to_cpu(raw_inode->i_namelen);
+	fname.disk_name.name = raw_inode->i_name;
+
+	if (unlikely(fname.disk_name.len > F2FS_NAME_LEN)) {
+		WARN_ON(1);
+		err = -ENAMETOOLONG;
+		goto out;
+	}
+retry:
+	de = __f2fs_find_entry(dir, &fname, &page);
+	if (de && inode->i_ino == le32_to_cpu(de->ino))
+		goto out_put;
+
+	if (de) {
+		einode = f2fs_iget_retry(inode->i_sb, le32_to_cpu(de->ino));
+		if (IS_ERR(einode)) {
+			WARN_ON(1);
+			err = PTR_ERR(einode);
+			if (err == -ENOENT)
+				err = -EEXIST;
+			goto out_put;
+		}
+
+		err = dquot_initialize(einode);
+		if (err) {
+			iput(einode);
+			goto out_put;
+		}
+
+		err = acquire_orphan_inode(F2FS_I_SB(inode));
+		if (err) {
+			iput(einode);
+			goto out_put;
+		}
+		f2fs_delete_entry(de, page, dir, einode);
+		iput(einode);
+		goto retry;
+	} else if (IS_ERR(page)) {
+		err = PTR_ERR(page);
+	} else {
+		err = __f2fs_do_add_link(dir, &fname, inode,
+					inode->i_ino, inode->i_mode);
+	}
+	if (err == -ENOMEM)
+		goto retry;
+	goto out;
+
+out_put:
+	f2fs_put_page(page, 0);
+out:
+	if (file_enc_name(inode))
+		name = "<encrypted>";
+	else
+		name = raw_inode->i_name;
+	f2fs_msg(inode->i_sb, KERN_NOTICE,
+			"%s: ino = %x, name = %s, dir = %lx, err = %d",
+			__func__, ino_of_node(ipage), name,
+			IS_ERR(dir) ? 0 : dir->i_ino, err);
+	return err;
+}
+
+static void recover_inline_flags(struct inode *inode, struct f2fs_inode *ri)
+{
+	if (ri->i_inline & F2FS_PIN_FILE)
+		set_inode_flag(inode, FI_PIN_FILE);
+	else
+		clear_inode_flag(inode, FI_PIN_FILE);
+	if (ri->i_inline & F2FS_DATA_EXIST)
+		set_inode_flag(inode, FI_DATA_EXIST);
+	else
+		clear_inode_flag(inode, FI_DATA_EXIST);
+	if (!(ri->i_inline & F2FS_INLINE_DOTS))
+		clear_inode_flag(inode, FI_INLINE_DOTS);
+}
+
+static void recover_inode(struct inode *inode, struct page *page)
+{
+	struct f2fs_inode *raw = F2FS_INODE(page);
+	char *name;
+
+	inode->i_mode = le16_to_cpu(raw->i_mode);
+	f2fs_i_size_write(inode, le64_to_cpu(raw->i_size));
+	inode->i_atime.tv_sec = le64_to_cpu(raw->i_atime);
+	inode->i_ctime.tv_sec = le64_to_cpu(raw->i_ctime);
+	inode->i_mtime.tv_sec = le64_to_cpu(raw->i_mtime);
+	inode->i_atime.tv_nsec = le32_to_cpu(raw->i_atime_nsec);
+	inode->i_ctime.tv_nsec = le32_to_cpu(raw->i_ctime_nsec);
+	inode->i_mtime.tv_nsec = le32_to_cpu(raw->i_mtime_nsec);
+
+	F2FS_I(inode)->i_advise = raw->i_advise;
+	F2FS_I(inode)->i_flags = le32_to_cpu(raw->i_flags);
+
+	recover_inline_flags(inode, raw);
+
+	if (file_enc_name(inode))
+		name = "<encrypted>";
+	else
+		name = F2FS_INODE(page)->i_name;
+
+	f2fs_msg(inode->i_sb, KERN_NOTICE,
+		"recover_inode: ino = %x, name = %s, inline = %x",
+			ino_of_node(page), name, raw->i_inline);
+}
+
+static int find_fsync_dnodes(struct f2fs_sb_info *sbi, struct list_head *head,
+				bool check_only)
+{
+	struct curseg_info *curseg;
+	struct page *page = NULL;
+	block_t blkaddr;
+	unsigned int loop_cnt = 0;
+	unsigned int free_blocks = sbi->user_block_count -
+					valid_user_blocks(sbi);
+	int err = 0;
+
+	/* get node pages in the current segment */
+	curseg = CURSEG_I(sbi, CURSEG_WARM_NODE);
+	blkaddr = NEXT_FREE_BLKADDR(sbi, curseg);
+
+	while (1) {
+		struct fsync_inode_entry *entry;
+
+		if (!f2fs_is_valid_blkaddr(sbi, blkaddr, META_POR))
+			return 0;
+
+		page = get_tmp_page(sbi, blkaddr);
+
+		if (!is_recoverable_dnode(page))
+			break;
+
+		if (!is_fsync_dnode(page))
+			goto next;
+
+		entry = get_fsync_inode(head, ino_of_node(page));
+		if (!entry) {
+			bool quota_inode = false;
+
+			if (!check_only &&
+					IS_INODE(page) && is_dent_dnode(page)) {
+				err = recover_inode_page(sbi, page);
+				if (err)
+					break;
+				quota_inode = true;
+			}
+
+			/*
+			 * CP | dnode(F) | inode(DF)
+			 * For this case, we should not give up now.
+			 */
+			entry = add_fsync_inode(sbi, head, ino_of_node(page),
+								quota_inode);
+			if (IS_ERR(entry)) {
+				err = PTR_ERR(entry);
+				if (err == -ENOENT) {
+					err = 0;
+					goto next;
+				}
+				break;
+			}
+		}
+		entry->blkaddr = blkaddr;
+
+		if (IS_INODE(page) && is_dent_dnode(page))
+			entry->last_dentry = blkaddr;
+next:
+		/* sanity check in order to detect looped node chain */
+		if (++loop_cnt >= free_blocks ||
+			blkaddr == next_blkaddr_of_node(page)) {
+			f2fs_msg(sbi->sb, KERN_NOTICE,
+				"%s: detect looped node chain, "
+				"blkaddr:%u, next:%u",
+				__func__, blkaddr, next_blkaddr_of_node(page));
+			err = -EINVAL;
+			break;
+		}
+
+		/* check next segment */
+		blkaddr = next_blkaddr_of_node(page);
+		f2fs_put_page(page, 1);
+
+		ra_meta_pages_cond(sbi, blkaddr);
+	}
+	f2fs_put_page(page, 1);
+	return err;
+}
+
+static void destroy_fsync_dnodes(struct list_head *head)
+{
+	struct fsync_inode_entry *entry, *tmp;
+
+	list_for_each_entry_safe(entry, tmp, head, list)
+		del_fsync_inode(entry);
+}
+
+static int check_index_in_prev_nodes(struct f2fs_sb_info *sbi,
+			block_t blkaddr, struct dnode_of_data *dn)
+{
+	struct seg_entry *sentry;
+	unsigned int segno = GET_SEGNO(sbi, blkaddr);
+	unsigned short blkoff = GET_BLKOFF_FROM_SEG0(sbi, blkaddr);
+	struct f2fs_summary_block *sum_node;
+	struct f2fs_summary sum;
+	struct page *sum_page, *node_page;
+	struct dnode_of_data tdn = *dn;
+	nid_t ino, nid;
+	struct inode *inode;
+	unsigned int offset;
+	block_t bidx;
+	int i;
+
+	sentry = get_seg_entry(sbi, segno);
+	if (!f2fs_test_bit(blkoff, sentry->cur_valid_map))
+		return 0;
+
+	/* Get the previous summary */
+	for (i = CURSEG_HOT_DATA; i <= CURSEG_COLD_DATA; i++) {
+		struct curseg_info *curseg = CURSEG_I(sbi, i);
+		if (curseg->segno == segno) {
+			sum = curseg->sum_blk->entries[blkoff];
+			goto got_it;
+		}
+	}
+
+	sum_page = get_sum_page(sbi, segno);
+	sum_node = (struct f2fs_summary_block *)page_address(sum_page);
+	sum = sum_node->entries[blkoff];
+	f2fs_put_page(sum_page, 1);
+got_it:
+	/* Use the locked dnode page and inode */
+	nid = le32_to_cpu(sum.nid);
+	if (dn->inode->i_ino == nid) {
+		tdn.nid = nid;
+		if (!dn->inode_page_locked)
+			lock_page(dn->inode_page);
+		tdn.node_page = dn->inode_page;
+		tdn.ofs_in_node = le16_to_cpu(sum.ofs_in_node);
+		goto truncate_out;
+	} else if (dn->nid == nid) {
+		tdn.ofs_in_node = le16_to_cpu(sum.ofs_in_node);
+		goto truncate_out;
+	}
+
+	/* Get the node page */
+	node_page = get_node_page(sbi, nid);
+	if (IS_ERR(node_page))
+		return PTR_ERR(node_page);
+
+	offset = ofs_of_node(node_page);
+	ino = ino_of_node(node_page);
+	f2fs_put_page(node_page, 1);
+
+	if (ino != dn->inode->i_ino) {
+		int ret;
+
+		/* Deallocate previous index in the node page */
+		inode = f2fs_iget_retry(sbi->sb, ino);
+		if (IS_ERR(inode))
+			return PTR_ERR(inode);
+
+		ret = dquot_initialize(inode);
+		if (ret) {
+			iput(inode);
+			return ret;
+		}
+	} else {
+		inode = dn->inode;
+	}
+
+	bidx = start_bidx_of_node(offset, inode) + le16_to_cpu(sum.ofs_in_node);
+
+	/*
+	 * if inode page is locked, unlock temporarily, but its reference
+	 * count keeps alive.
+	 */
+	if (ino == dn->inode->i_ino && dn->inode_page_locked)
+		unlock_page(dn->inode_page);
+
+	set_new_dnode(&tdn, inode, NULL, NULL, 0);
+	if (get_dnode_of_data(&tdn, bidx, LOOKUP_NODE))
+		goto out;
+
+	if (tdn.data_blkaddr == blkaddr)
+		truncate_data_blocks_range(&tdn, 1);
+
+	f2fs_put_dnode(&tdn);
+out:
+	if (ino != dn->inode->i_ino)
+		iput(inode);
+	else if (dn->inode_page_locked)
+		lock_page(dn->inode_page);
+	return 0;
+
+truncate_out:
+	if (datablock_addr(tdn.inode, tdn.node_page,
+					tdn.ofs_in_node) == blkaddr)
+		truncate_data_blocks_range(&tdn, 1);
+	if (dn->inode->i_ino == nid && !dn->inode_page_locked)
+		unlock_page(dn->inode_page);
+	return 0;
+}
+
+static int do_recover_data(struct f2fs_sb_info *sbi, struct inode *inode,
+					struct page *page)
+{
+	struct dnode_of_data dn;
+	struct node_info ni;
+	unsigned int start, end;
+	int err = 0, recovered = 0;
+
+	/* step 1: recover xattr */
+	if (IS_INODE(page)) {
+		recover_inline_xattr(inode, page);
+	} else if (f2fs_has_xattr_block(ofs_of_node(page))) {
+		err = recover_xattr_data(inode, page);
+		if (!err)
+			recovered++;
+		goto out;
+	}
+
+	/* step 2: recover inline data */
+	if (recover_inline_data(inode, page))
+		goto out;
+
+	/* step 3: recover data indices */
+	start = start_bidx_of_node(ofs_of_node(page), inode);
+	end = start + ADDRS_PER_PAGE(page, inode);
+
+	set_new_dnode(&dn, inode, NULL, NULL, 0);
+retry_dn:
+	err = get_dnode_of_data(&dn, start, ALLOC_NODE);
+	if (err) {
+		if (err == -ENOMEM) {
+			congestion_wait(BLK_RW_ASYNC, HZ/50);
+			goto retry_dn;
+		}
+		goto out;
+	}
+
+	f2fs_wait_on_page_writeback(dn.node_page, NODE, true);
+
+	get_node_info(sbi, dn.nid, &ni);
+	f2fs_bug_on(sbi, ni.ino != ino_of_node(page));
+
+	if (ofs_of_node(dn.node_page) != ofs_of_node(page)) {
+		f2fs_msg(sbi->sb, KERN_WARNING,
+			"Inconsistent ofs_of_node, ino:%lu, ofs:%u, %u",
+			inode->i_ino, ofs_of_node(dn.node_page),
+			ofs_of_node(page));
+		err = -EFSCORRUPTED;
+		goto err;
+	}
+
+	for (; start < end; start++, dn.ofs_in_node++) {
+		block_t src, dest;
+
+		src = datablock_addr(dn.inode, dn.node_page, dn.ofs_in_node);
+		dest = datablock_addr(dn.inode, page, dn.ofs_in_node);
+
+		/* skip recovering if dest is the same as src */
+		if (src == dest)
+			continue;
+
+		/* dest is invalid, just invalidate src block */
+		if (dest == NULL_ADDR) {
+			truncate_data_blocks_range(&dn, 1);
+			continue;
+		}
+
+		if (!file_keep_isize(inode) &&
+			(i_size_read(inode) <= ((loff_t)start << PAGE_SHIFT)))
+			f2fs_i_size_write(inode,
+				(loff_t)(start + 1) << PAGE_SHIFT);
+
+		/*
+		 * dest is reserved block, invalidate src block
+		 * and then reserve one new block in dnode page.
+		 */
+		if (dest == NEW_ADDR) {
+			truncate_data_blocks_range(&dn, 1);
+			reserve_new_block(&dn);
+			continue;
+		}
+
+		/* dest is valid block, try to recover from src to dest */
+		if (f2fs_is_valid_blkaddr(sbi, dest, META_POR)) {
+
+			if (src == NULL_ADDR) {
+				err = reserve_new_block(&dn);
+#ifdef CONFIG_F2FS_FAULT_INJECTION
+				while (err)
+					err = reserve_new_block(&dn);
+#endif
+				/* We should not get -ENOSPC */
+				f2fs_bug_on(sbi, err);
+				if (err)
+					goto err;
+			}
+retry_prev:
+			/* Check the previous node page having this index */
+			err = check_index_in_prev_nodes(sbi, dest, &dn);
+			if (err) {
+				if (err == -ENOMEM) {
+					congestion_wait(BLK_RW_ASYNC, HZ/50);
+					goto retry_prev;
+				}
+				goto err;
+			}
+
+			/* write dummy data page */
+			f2fs_replace_block(sbi, &dn, src, dest,
+						ni.version, false, false);
+			recovered++;
+		}
+	}
+
+	copy_node_footer(dn.node_page, page);
+	fill_node_footer(dn.node_page, dn.nid, ni.ino,
+					ofs_of_node(page), false);
+	set_page_dirty(dn.node_page);
+err:
+	f2fs_put_dnode(&dn);
+out:
+	f2fs_msg(sbi->sb, KERN_NOTICE,
+		"recover_data: ino = %lx (i_size: %s) recovered = %d, err = %d",
+		inode->i_ino,
+		file_keep_isize(inode) ? "keep" : "recover",
+		recovered, err);
+	return err;
+}
+
+static int recover_data(struct f2fs_sb_info *sbi, struct list_head *inode_list,
+						struct list_head *dir_list)
+{
+	struct curseg_info *curseg;
+	struct page *page = NULL;
+	int err = 0;
+	block_t blkaddr;
+
+	/* get node pages in the current segment */
+	curseg = CURSEG_I(sbi, CURSEG_WARM_NODE);
+	blkaddr = NEXT_FREE_BLKADDR(sbi, curseg);
+
+	while (1) {
+		struct fsync_inode_entry *entry;
+
+		if (!f2fs_is_valid_blkaddr(sbi, blkaddr, META_POR))
+			break;
+
+		ra_meta_pages_cond(sbi, blkaddr);
+
+		page = get_tmp_page(sbi, blkaddr);
+
+		if (!is_recoverable_dnode(page)) {
+			f2fs_put_page(page, 1);
+			break;
+		}
+
+		entry = get_fsync_inode(inode_list, ino_of_node(page));
+		if (!entry)
+			goto next;
+		/*
+		 * inode(x) | CP | inode(x) | dnode(F)
+		 * In this case, we can lose the latest inode(x).
+		 * So, call recover_inode for the inode update.
+		 */
+		if (IS_INODE(page))
+			recover_inode(entry->inode, page);
+		if (entry->last_dentry == blkaddr) {
+			err = recover_dentry(entry->inode, page, dir_list);
+			if (err) {
+				f2fs_put_page(page, 1);
+				break;
+			}
+		}
+		err = do_recover_data(sbi, entry->inode, page);
+		if (err) {
+			f2fs_put_page(page, 1);
+			break;
+		}
+
+		if (entry->blkaddr == blkaddr)
+			del_fsync_inode(entry);
+next:
+		/* check next segment */
+		blkaddr = next_blkaddr_of_node(page);
+		f2fs_put_page(page, 1);
+	}
+	if (!err)
+		allocate_new_segments(sbi);
+	return err;
+}
+
+int recover_fsync_data(struct f2fs_sb_info *sbi, bool check_only)
+{
+	struct list_head inode_list;
+	struct list_head dir_list;
+	int err;
+	int ret = 0;
+	unsigned long s_flags = sbi->sb->s_flags;
+	bool need_writecp = false;
+#ifdef CONFIG_QUOTA
+	int quota_enabled;
+#endif
+
+	if (s_flags & MS_RDONLY) {
+		f2fs_msg(sbi->sb, KERN_INFO, "orphan cleanup on readonly fs");
+		sbi->sb->s_flags &= ~MS_RDONLY;
+	}
+
+#ifdef CONFIG_QUOTA
+	/* Needed for iput() to work correctly and not trash data */
+	sbi->sb->s_flags |= MS_ACTIVE;
+	/* Turn on quotas so that they are updated correctly */
+	quota_enabled = f2fs_enable_quota_files(sbi, s_flags & MS_RDONLY);
+#endif
+
+	fsync_entry_slab = f2fs_kmem_cache_create("f2fs_fsync_inode_entry",
+			sizeof(struct fsync_inode_entry));
+	if (!fsync_entry_slab) {
+		err = -ENOMEM;
+		goto out;
+	}
+
+	INIT_LIST_HEAD(&inode_list);
+	INIT_LIST_HEAD(&dir_list);
+
+	/* prevent checkpoint */
+	mutex_lock(&sbi->cp_mutex);
+
+	/* step #1: find fsynced inode numbers */
+	err = find_fsync_dnodes(sbi, &inode_list, check_only);
+	if (err || list_empty(&inode_list))
+		goto skip;
+
+	if (check_only) {
+		ret = 1;
+		goto skip;
+	}
+
+	need_writecp = true;
+
+	/* step #2: recover data */
+	err = recover_data(sbi, &inode_list, &dir_list);
+	if (!err)
+		f2fs_bug_on(sbi, !list_empty(&inode_list));
+skip:
+	destroy_fsync_dnodes(&inode_list);
+
+	/* truncate meta pages to be used by the recovery */
+	truncate_inode_pages_range(META_MAPPING(sbi),
+			(loff_t)MAIN_BLKADDR(sbi) << PAGE_SHIFT, -1);
+
+	if (err) {
+		truncate_inode_pages_final(NODE_MAPPING(sbi));
+		truncate_inode_pages_final(META_MAPPING(sbi));
+	}
+
+	clear_sbi_flag(sbi, SBI_POR_DOING);
+	mutex_unlock(&sbi->cp_mutex);
+
+	/* let's drop all the directory inodes for clean checkpoint */
+	destroy_fsync_dnodes(&dir_list);
+
+	if (!err && need_writecp) {
+		struct cp_control cpc = {
+			.reason = CP_RECOVERY,
+		};
+		err = write_checkpoint(sbi, &cpc);
+	}
+
+	kmem_cache_destroy(fsync_entry_slab);
+out:
+#ifdef CONFIG_QUOTA
+	/* Turn quotas off */
+	if (quota_enabled)
+		f2fs_quota_off_umount(sbi->sb);
+#endif
+	sbi->sb->s_flags = s_flags; /* Restore MS_RDONLY status */
+
+	return ret ? ret: err;
+}
diff --git a/src/kernel/linux/v4.14/fs/f2fs/segment.c b/src/kernel/linux/v4.14/fs/f2fs/segment.c
new file mode 100644
index 0000000..594382f
--- /dev/null
+++ b/src/kernel/linux/v4.14/fs/f2fs/segment.c
@@ -0,0 +1,4098 @@
+/*
+ * fs/f2fs/segment.c
+ *
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ *             http://www.samsung.com/
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/fs.h>
+#include <linux/f2fs_fs.h>
+#include <linux/bio.h>
+#include <linux/blkdev.h>
+#include <linux/prefetch.h>
+#include <linux/kthread.h>
+#include <linux/swap.h>
+#include <linux/timer.h>
+#include <linux/freezer.h>
+#include <linux/sched/signal.h>
+
+#include "f2fs.h"
+#include "segment.h"
+#include "node.h"
+#include "gc.h"
+#include "trace.h"
+#include <trace/events/f2fs.h>
+
+#define __reverse_ffz(x) __reverse_ffs(~(x))
+
+static struct kmem_cache *discard_entry_slab;
+static struct kmem_cache *discard_cmd_slab;
+static struct kmem_cache *sit_entry_set_slab;
+static struct kmem_cache *inmem_entry_slab;
+
+static unsigned long __reverse_ulong(unsigned char *str)
+{
+	unsigned long tmp = 0;
+	int shift = 24, idx = 0;
+
+#if BITS_PER_LONG == 64
+	shift = 56;
+#endif
+	while (shift >= 0) {
+		tmp |= (unsigned long)str[idx++] << shift;
+		shift -= BITS_PER_BYTE;
+	}
+	return tmp;
+}
+
+/*
+ * __reverse_ffs is copied from include/asm-generic/bitops/__ffs.h since
+ * MSB and LSB are reversed in a byte by f2fs_set_bit.
+ */
+static inline unsigned long __reverse_ffs(unsigned long word)
+{
+	int num = 0;
+
+#if BITS_PER_LONG == 64
+	if ((word & 0xffffffff00000000UL) == 0)
+		num += 32;
+	else
+		word >>= 32;
+#endif
+	if ((word & 0xffff0000) == 0)
+		num += 16;
+	else
+		word >>= 16;
+
+	if ((word & 0xff00) == 0)
+		num += 8;
+	else
+		word >>= 8;
+
+	if ((word & 0xf0) == 0)
+		num += 4;
+	else
+		word >>= 4;
+
+	if ((word & 0xc) == 0)
+		num += 2;
+	else
+		word >>= 2;
+
+	if ((word & 0x2) == 0)
+		num += 1;
+	return num;
+}
+
+/*
+ * __find_rev_next(_zero)_bit is copied from lib/find_next_bit.c because
+ * f2fs_set_bit makes MSB and LSB reversed in a byte.
+ * @size must be integral times of unsigned long.
+ * Example:
+ *                             MSB <--> LSB
+ *   f2fs_set_bit(0, bitmap) => 1000 0000
+ *   f2fs_set_bit(7, bitmap) => 0000 0001
+ */
+static unsigned long __find_rev_next_bit(const unsigned long *addr,
+			unsigned long size, unsigned long offset)
+{
+	const unsigned long *p = addr + BIT_WORD(offset);
+	unsigned long result = size;
+	unsigned long tmp;
+
+	if (offset >= size)
+		return size;
+
+	size -= (offset & ~(BITS_PER_LONG - 1));
+	offset %= BITS_PER_LONG;
+
+	while (1) {
+		if (*p == 0)
+			goto pass;
+
+		tmp = __reverse_ulong((unsigned char *)p);
+
+		tmp &= ~0UL >> offset;
+		if (size < BITS_PER_LONG)
+			tmp &= (~0UL << (BITS_PER_LONG - size));
+		if (tmp)
+			goto found;
+pass:
+		if (size <= BITS_PER_LONG)
+			break;
+		size -= BITS_PER_LONG;
+		offset = 0;
+		p++;
+	}
+	return result;
+found:
+	return result - size + __reverse_ffs(tmp);
+}
+
+static unsigned long __find_rev_next_zero_bit(const unsigned long *addr,
+			unsigned long size, unsigned long offset)
+{
+	const unsigned long *p = addr + BIT_WORD(offset);
+	unsigned long result = size;
+	unsigned long tmp;
+
+	if (offset >= size)
+		return size;
+
+	size -= (offset & ~(BITS_PER_LONG - 1));
+	offset %= BITS_PER_LONG;
+
+	while (1) {
+		if (*p == ~0UL)
+			goto pass;
+
+		tmp = __reverse_ulong((unsigned char *)p);
+
+		if (offset)
+			tmp |= ~0UL << (BITS_PER_LONG - offset);
+		if (size < BITS_PER_LONG)
+			tmp |= ~0UL >> size;
+		if (tmp != ~0UL)
+			goto found;
+pass:
+		if (size <= BITS_PER_LONG)
+			break;
+		size -= BITS_PER_LONG;
+		offset = 0;
+		p++;
+	}
+	return result;
+found:
+	return result - size + __reverse_ffz(tmp);
+}
+
+bool need_SSR(struct f2fs_sb_info *sbi)
+{
+	int node_secs = get_blocktype_secs(sbi, F2FS_DIRTY_NODES);
+	int dent_secs = get_blocktype_secs(sbi, F2FS_DIRTY_DENTS);
+	int imeta_secs = get_blocktype_secs(sbi, F2FS_DIRTY_IMETA);
+
+	if (test_opt(sbi, LFS))
+		return false;
+	if (sbi->gc_thread && sbi->gc_thread->gc_urgent)
+		return true;
+
+	return free_sections(sbi) <= (node_secs + 2 * dent_secs + imeta_secs +
+			SM_I(sbi)->min_ssr_sections + reserved_sections(sbi));
+}
+
+void register_inmem_page(struct inode *inode, struct page *page)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct f2fs_inode_info *fi = F2FS_I(inode);
+	struct inmem_pages *new;
+
+	f2fs_trace_pid(page);
+
+	set_page_private(page, (unsigned long)ATOMIC_WRITTEN_PAGE);
+	SetPagePrivate(page);
+
+	new = f2fs_kmem_cache_alloc(inmem_entry_slab, GFP_NOFS);
+
+	/* add atomic page indices to the list */
+	new->page = page;
+	INIT_LIST_HEAD(&new->list);
+
+	/* increase reference count with clean state */
+	mutex_lock(&fi->inmem_lock);
+	get_page(page);
+	list_add_tail(&new->list, &fi->inmem_pages);
+	spin_lock(&sbi->inode_lock[ATOMIC_FILE]);
+	if (list_empty(&fi->inmem_ilist))
+		list_add_tail(&fi->inmem_ilist, &sbi->inode_list[ATOMIC_FILE]);
+	spin_unlock(&sbi->inode_lock[ATOMIC_FILE]);
+	inc_page_count(F2FS_I_SB(inode), F2FS_INMEM_PAGES);
+	mutex_unlock(&fi->inmem_lock);
+
+	trace_f2fs_register_inmem_page(page, INMEM);
+}
+
+static int __revoke_inmem_pages(struct inode *inode,
+				struct list_head *head, bool drop, bool recover)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct inmem_pages *cur, *tmp;
+	int err = 0;
+
+	list_for_each_entry_safe(cur, tmp, head, list) {
+		struct page *page = cur->page;
+
+		if (drop)
+			trace_f2fs_commit_inmem_page(page, INMEM_DROP);
+
+		lock_page(page);
+
+		f2fs_wait_on_page_writeback(page, DATA, true);
+
+		if (recover) {
+			struct dnode_of_data dn;
+			struct node_info ni;
+
+			trace_f2fs_commit_inmem_page(page, INMEM_REVOKE);
+retry:
+			set_new_dnode(&dn, inode, NULL, NULL, 0);
+			err = get_dnode_of_data(&dn, page->index, LOOKUP_NODE);
+			if (err) {
+				if (err == -ENOMEM) {
+					congestion_wait(BLK_RW_ASYNC, HZ/50);
+					cond_resched();
+					goto retry;
+				}
+				err = -EAGAIN;
+				goto next;
+			}
+			get_node_info(sbi, dn.nid, &ni);
+			if (cur->old_addr == NEW_ADDR) {
+				invalidate_blocks(sbi, dn.data_blkaddr);
+				f2fs_update_data_blkaddr(&dn, NEW_ADDR);
+			} else
+				f2fs_replace_block(sbi, &dn, dn.data_blkaddr,
+					cur->old_addr, ni.version, true, true);
+			f2fs_put_dnode(&dn);
+		}
+next:
+		/* we don't need to invalidate this in the sccessful status */
+		if (drop || recover) {
+			ClearPageUptodate(page);
+			clear_cold_data(page);
+		}
+		set_page_private(page, 0);
+		ClearPagePrivate(page);
+		f2fs_put_page(page, 1);
+
+		list_del(&cur->list);
+		kmem_cache_free(inmem_entry_slab, cur);
+		dec_page_count(F2FS_I_SB(inode), F2FS_INMEM_PAGES);
+	}
+	return err;
+}
+
+void drop_inmem_pages_all(struct f2fs_sb_info *sbi)
+{
+	struct list_head *head = &sbi->inode_list[ATOMIC_FILE];
+	struct inode *inode;
+	struct f2fs_inode_info *fi;
+next:
+	spin_lock(&sbi->inode_lock[ATOMIC_FILE]);
+	if (list_empty(head)) {
+		spin_unlock(&sbi->inode_lock[ATOMIC_FILE]);
+		return;
+	}
+	fi = list_first_entry(head, struct f2fs_inode_info, inmem_ilist);
+	inode = igrab(&fi->vfs_inode);
+	spin_unlock(&sbi->inode_lock[ATOMIC_FILE]);
+
+	if (inode) {
+		drop_inmem_pages(inode);
+		iput(inode);
+	}
+	congestion_wait(BLK_RW_ASYNC, HZ/50);
+	cond_resched();
+	goto next;
+}
+
+void drop_inmem_pages(struct inode *inode)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct f2fs_inode_info *fi = F2FS_I(inode);
+
+	mutex_lock(&fi->inmem_lock);
+	__revoke_inmem_pages(inode, &fi->inmem_pages, true, false);
+	spin_lock(&sbi->inode_lock[ATOMIC_FILE]);
+	if (!list_empty(&fi->inmem_ilist))
+		list_del_init(&fi->inmem_ilist);
+	spin_unlock(&sbi->inode_lock[ATOMIC_FILE]);
+	mutex_unlock(&fi->inmem_lock);
+
+	clear_inode_flag(inode, FI_ATOMIC_FILE);
+	clear_inode_flag(inode, FI_HOT_DATA);
+	stat_dec_atomic_write(inode);
+}
+
+void drop_inmem_page(struct inode *inode, struct page *page)
+{
+	struct f2fs_inode_info *fi = F2FS_I(inode);
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct list_head *head = &fi->inmem_pages;
+	struct inmem_pages *cur = NULL;
+
+	f2fs_bug_on(sbi, !IS_ATOMIC_WRITTEN_PAGE(page));
+
+	mutex_lock(&fi->inmem_lock);
+	list_for_each_entry(cur, head, list) {
+		if (cur->page == page)
+			break;
+	}
+
+	f2fs_bug_on(sbi, !cur || cur->page != page);
+	list_del(&cur->list);
+	mutex_unlock(&fi->inmem_lock);
+
+	dec_page_count(sbi, F2FS_INMEM_PAGES);
+	kmem_cache_free(inmem_entry_slab, cur);
+
+	ClearPageUptodate(page);
+	set_page_private(page, 0);
+	ClearPagePrivate(page);
+	f2fs_put_page(page, 0);
+
+	trace_f2fs_commit_inmem_page(page, INMEM_INVALIDATE);
+}
+
+static int __commit_inmem_pages(struct inode *inode,
+					struct list_head *revoke_list)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct f2fs_inode_info *fi = F2FS_I(inode);
+	struct inmem_pages *cur, *tmp;
+	struct f2fs_io_info fio = {
+		.sbi = sbi,
+		.ino = inode->i_ino,
+		.type = DATA,
+		.op = REQ_OP_WRITE,
+		.op_flags = REQ_SYNC | REQ_PRIO,
+		.io_type = FS_DATA_IO,
+	};
+	pgoff_t last_idx = ULONG_MAX;
+	int err = 0;
+
+	list_for_each_entry_safe(cur, tmp, &fi->inmem_pages, list) {
+		struct page *page = cur->page;
+
+		lock_page(page);
+		if (page->mapping == inode->i_mapping) {
+			trace_f2fs_commit_inmem_page(page, INMEM);
+
+			set_page_dirty(page);
+			f2fs_wait_on_page_writeback(page, DATA, true);
+			if (clear_page_dirty_for_io(page)) {
+				inode_dec_dirty_pages(inode);
+				remove_dirty_inode(inode);
+			}
+retry:
+			fio.page = page;
+			fio.old_blkaddr = NULL_ADDR;
+			fio.encrypted_page = NULL;
+			fio.need_lock = LOCK_DONE;
+			err = do_write_data_page(&fio);
+			if (err) {
+				if (err == -ENOMEM) {
+					congestion_wait(BLK_RW_ASYNC, HZ/50);
+					cond_resched();
+					goto retry;
+				}
+				unlock_page(page);
+				break;
+			}
+			/* record old blkaddr for revoking */
+			cur->old_addr = fio.old_blkaddr;
+			last_idx = page->index;
+		}
+		unlock_page(page);
+		list_move_tail(&cur->list, revoke_list);
+	}
+
+	if (last_idx != ULONG_MAX)
+		f2fs_submit_merged_write_cond(sbi, inode, 0, last_idx, DATA);
+
+	if (!err)
+		__revoke_inmem_pages(inode, revoke_list, false, false);
+
+	return err;
+}
+
+int commit_inmem_pages(struct inode *inode)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct f2fs_inode_info *fi = F2FS_I(inode);
+	struct list_head revoke_list;
+	int err;
+
+	INIT_LIST_HEAD(&revoke_list);
+	f2fs_balance_fs(sbi, true);
+	f2fs_lock_op(sbi);
+
+	set_inode_flag(inode, FI_ATOMIC_COMMIT);
+
+	mutex_lock(&fi->inmem_lock);
+	err = __commit_inmem_pages(inode, &revoke_list);
+	if (err) {
+		int ret;
+		/*
+		 * try to revoke all committed pages, but still we could fail
+		 * due to no memory or other reason, if that happened, EAGAIN
+		 * will be returned, which means in such case, transaction is
+		 * already not integrity, caller should use journal to do the
+		 * recovery or rewrite & commit last transaction. For other
+		 * error number, revoking was done by filesystem itself.
+		 */
+		ret = __revoke_inmem_pages(inode, &revoke_list, false, true);
+		if (ret)
+			err = ret;
+
+		/* drop all uncommitted pages */
+		__revoke_inmem_pages(inode, &fi->inmem_pages, true, false);
+	}
+	spin_lock(&sbi->inode_lock[ATOMIC_FILE]);
+	if (!list_empty(&fi->inmem_ilist))
+		list_del_init(&fi->inmem_ilist);
+	spin_unlock(&sbi->inode_lock[ATOMIC_FILE]);
+	mutex_unlock(&fi->inmem_lock);
+
+	clear_inode_flag(inode, FI_ATOMIC_COMMIT);
+
+	f2fs_unlock_op(sbi);
+	return err;
+}
+
+/*
+ * This function balances dirty node and dentry pages.
+ * In addition, it controls garbage collection.
+ */
+void f2fs_balance_fs(struct f2fs_sb_info *sbi, bool need)
+{
+#ifdef CONFIG_F2FS_FAULT_INJECTION
+	if (time_to_inject(sbi, FAULT_CHECKPOINT)) {
+		f2fs_show_injection_info(FAULT_CHECKPOINT);
+		f2fs_stop_checkpoint(sbi, false);
+	}
+#endif
+
+	/* balance_fs_bg is able to be pending */
+	if (need && excess_cached_nats(sbi))
+		f2fs_balance_fs_bg(sbi);
+
+	/*
+	 * We should do GC or end up with checkpoint, if there are so many dirty
+	 * dir/node pages without enough free segments.
+	 */
+	if (has_not_enough_free_secs(sbi, 0, 0)) {
+		mutex_lock(&sbi->gc_mutex);
+		f2fs_gc(sbi, false, false, NULL_SEGNO);
+	}
+}
+
+void f2fs_balance_fs_bg(struct f2fs_sb_info *sbi)
+{
+	if (unlikely(is_sbi_flag_set(sbi, SBI_POR_DOING)))
+		return;
+
+	/* try to shrink extent cache when there is no enough memory */
+	if (!available_free_memory(sbi, EXTENT_CACHE))
+		f2fs_shrink_extent_tree(sbi, EXTENT_CACHE_SHRINK_NUMBER);
+
+	/* check the # of cached NAT entries */
+	if (!available_free_memory(sbi, NAT_ENTRIES))
+		try_to_free_nats(sbi, NAT_ENTRY_PER_BLOCK);
+
+	if (!available_free_memory(sbi, FREE_NIDS))
+		try_to_free_nids(sbi, MAX_FREE_NIDS);
+	else
+		build_free_nids(sbi, false, false);
+
+	if (!is_idle(sbi) && !excess_dirty_nats(sbi))
+		return;
+
+	/* checkpoint is the only way to shrink partial cached entries */
+	if (!available_free_memory(sbi, NAT_ENTRIES) ||
+			!available_free_memory(sbi, INO_ENTRIES) ||
+			excess_prefree_segs(sbi) ||
+			excess_dirty_nats(sbi) ||
+			f2fs_time_over(sbi, CP_TIME)) {
+		if (test_opt(sbi, DATA_FLUSH)) {
+			struct blk_plug plug;
+
+			blk_start_plug(&plug);
+			sync_dirty_inodes(sbi, FILE_INODE);
+			blk_finish_plug(&plug);
+		}
+		f2fs_sync_fs(sbi->sb, true);
+		stat_inc_bg_cp_count(sbi->stat_info);
+	}
+}
+
+static int __submit_flush_wait(struct f2fs_sb_info *sbi,
+				struct block_device *bdev)
+{
+	struct bio *bio = f2fs_bio_alloc(sbi, 0, true);
+	int ret;
+
+	bio->bi_opf = REQ_OP_WRITE | REQ_SYNC | REQ_PREFLUSH;
+	bio_set_dev(bio, bdev);
+	ret = submit_bio_wait(bio);
+	bio_put(bio);
+
+	trace_f2fs_issue_flush(bdev, test_opt(sbi, NOBARRIER),
+				test_opt(sbi, FLUSH_MERGE), ret);
+	return ret;
+}
+
+static int submit_flush_wait(struct f2fs_sb_info *sbi, nid_t ino)
+{
+	int ret = 0;
+	int i;
+
+	if (!sbi->s_ndevs)
+		return __submit_flush_wait(sbi, sbi->sb->s_bdev);
+
+	for (i = 0; i < sbi->s_ndevs; i++) {
+		if (!is_dirty_device(sbi, ino, i, FLUSH_INO))
+			continue;
+		ret = __submit_flush_wait(sbi, FDEV(i).bdev);
+		if (ret)
+			break;
+	}
+	return ret;
+}
+
+static int issue_flush_thread(void *data)
+{
+	struct f2fs_sb_info *sbi = data;
+	struct flush_cmd_control *fcc = SM_I(sbi)->fcc_info;
+	wait_queue_head_t *q = &fcc->flush_wait_queue;
+repeat:
+	if (kthread_should_stop())
+		return 0;
+
+	sb_start_intwrite(sbi->sb);
+
+	if (!llist_empty(&fcc->issue_list)) {
+		struct flush_cmd *cmd, *next;
+		int ret;
+
+		fcc->dispatch_list = llist_del_all(&fcc->issue_list);
+		fcc->dispatch_list = llist_reverse_order(fcc->dispatch_list);
+
+		cmd = llist_entry(fcc->dispatch_list, struct flush_cmd, llnode);
+
+		ret = submit_flush_wait(sbi, cmd->ino);
+		atomic_inc(&fcc->issued_flush);
+
+		llist_for_each_entry_safe(cmd, next,
+					  fcc->dispatch_list, llnode) {
+			cmd->ret = ret;
+			complete(&cmd->wait);
+		}
+		fcc->dispatch_list = NULL;
+	}
+
+	sb_end_intwrite(sbi->sb);
+
+	wait_event_interruptible(*q,
+		kthread_should_stop() || !llist_empty(&fcc->issue_list));
+	goto repeat;
+}
+
+int f2fs_issue_flush(struct f2fs_sb_info *sbi, nid_t ino)
+{
+	struct flush_cmd_control *fcc = SM_I(sbi)->fcc_info;
+	struct flush_cmd cmd;
+	int ret;
+
+	if (test_opt(sbi, NOBARRIER))
+		return 0;
+
+	if (!test_opt(sbi, FLUSH_MERGE)) {
+		ret = submit_flush_wait(sbi, ino);
+		atomic_inc(&fcc->issued_flush);
+		return ret;
+	}
+
+	if (atomic_inc_return(&fcc->issing_flush) == 1 || sbi->s_ndevs > 1) {
+		ret = submit_flush_wait(sbi, ino);
+		atomic_dec(&fcc->issing_flush);
+
+		atomic_inc(&fcc->issued_flush);
+		return ret;
+	}
+
+	cmd.ino = ino;
+	init_completion(&cmd.wait);
+
+	llist_add(&cmd.llnode, &fcc->issue_list);
+
+	/* update issue_list before we wake up issue_flush thread */
+	smp_mb();
+
+	if (waitqueue_active(&fcc->flush_wait_queue))
+		wake_up(&fcc->flush_wait_queue);
+
+	if (fcc->f2fs_issue_flush) {
+		wait_for_completion(&cmd.wait);
+		atomic_dec(&fcc->issing_flush);
+	} else {
+		struct llist_node *list;
+
+		list = llist_del_all(&fcc->issue_list);
+		if (!list) {
+			wait_for_completion(&cmd.wait);
+			atomic_dec(&fcc->issing_flush);
+		} else {
+			struct flush_cmd *tmp, *next;
+
+			ret = submit_flush_wait(sbi, ino);
+
+			llist_for_each_entry_safe(tmp, next, list, llnode) {
+				if (tmp == &cmd) {
+					cmd.ret = ret;
+					atomic_dec(&fcc->issing_flush);
+					continue;
+				}
+				tmp->ret = ret;
+				complete(&tmp->wait);
+			}
+		}
+	}
+
+	return cmd.ret;
+}
+
+int create_flush_cmd_control(struct f2fs_sb_info *sbi)
+{
+	dev_t dev = sbi->sb->s_bdev->bd_dev;
+	struct flush_cmd_control *fcc;
+	int err = 0;
+
+	if (SM_I(sbi)->fcc_info) {
+		fcc = SM_I(sbi)->fcc_info;
+		if (fcc->f2fs_issue_flush)
+			return err;
+		goto init_thread;
+	}
+
+	fcc = f2fs_kzalloc(sbi, sizeof(struct flush_cmd_control), GFP_KERNEL);
+	if (!fcc)
+		return -ENOMEM;
+	atomic_set(&fcc->issued_flush, 0);
+	atomic_set(&fcc->issing_flush, 0);
+	init_waitqueue_head(&fcc->flush_wait_queue);
+	init_llist_head(&fcc->issue_list);
+	SM_I(sbi)->fcc_info = fcc;
+	if (!test_opt(sbi, FLUSH_MERGE))
+		return err;
+
+init_thread:
+	fcc->f2fs_issue_flush = kthread_run(issue_flush_thread, sbi,
+				"f2fs_flush-%u:%u", MAJOR(dev), MINOR(dev));
+	if (IS_ERR(fcc->f2fs_issue_flush)) {
+		err = PTR_ERR(fcc->f2fs_issue_flush);
+		kfree(fcc);
+		SM_I(sbi)->fcc_info = NULL;
+		return err;
+	}
+
+	return err;
+}
+
+void destroy_flush_cmd_control(struct f2fs_sb_info *sbi, bool free)
+{
+	struct flush_cmd_control *fcc = SM_I(sbi)->fcc_info;
+
+	if (fcc && fcc->f2fs_issue_flush) {
+		struct task_struct *flush_thread = fcc->f2fs_issue_flush;
+
+		fcc->f2fs_issue_flush = NULL;
+		kthread_stop(flush_thread);
+	}
+	if (free) {
+		kfree(fcc);
+		SM_I(sbi)->fcc_info = NULL;
+	}
+}
+
+int f2fs_flush_device_cache(struct f2fs_sb_info *sbi)
+{
+	int ret = 0, i;
+
+	if (!sbi->s_ndevs)
+		return 0;
+
+	for (i = 1; i < sbi->s_ndevs; i++) {
+		if (!f2fs_test_bit(i, (char *)&sbi->dirty_device))
+			continue;
+		ret = __submit_flush_wait(sbi, FDEV(i).bdev);
+		if (ret)
+			break;
+
+		spin_lock(&sbi->dev_lock);
+		f2fs_clear_bit(i, (char *)&sbi->dirty_device);
+		spin_unlock(&sbi->dev_lock);
+	}
+
+	return ret;
+}
+
+static void __locate_dirty_segment(struct f2fs_sb_info *sbi, unsigned int segno,
+		enum dirty_type dirty_type)
+{
+	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
+
+	/* need not be added */
+	if (IS_CURSEG(sbi, segno))
+		return;
+
+	if (!test_and_set_bit(segno, dirty_i->dirty_segmap[dirty_type]))
+		dirty_i->nr_dirty[dirty_type]++;
+
+	if (dirty_type == DIRTY) {
+		struct seg_entry *sentry = get_seg_entry(sbi, segno);
+		enum dirty_type t = sentry->type;
+
+		if (unlikely(t >= DIRTY)) {
+			f2fs_bug_on(sbi, 1);
+			return;
+		}
+		if (!test_and_set_bit(segno, dirty_i->dirty_segmap[t]))
+			dirty_i->nr_dirty[t]++;
+	}
+}
+
+static void __remove_dirty_segment(struct f2fs_sb_info *sbi, unsigned int segno,
+		enum dirty_type dirty_type)
+{
+	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
+
+	if (test_and_clear_bit(segno, dirty_i->dirty_segmap[dirty_type]))
+		dirty_i->nr_dirty[dirty_type]--;
+
+	if (dirty_type == DIRTY) {
+		struct seg_entry *sentry = get_seg_entry(sbi, segno);
+		enum dirty_type t = sentry->type;
+
+		if (test_and_clear_bit(segno, dirty_i->dirty_segmap[t]))
+			dirty_i->nr_dirty[t]--;
+
+		if (get_valid_blocks(sbi, segno, true) == 0)
+			clear_bit(GET_SEC_FROM_SEG(sbi, segno),
+						dirty_i->victim_secmap);
+	}
+}
+
+/*
+ * Should not occur error such as -ENOMEM.
+ * Adding dirty entry into seglist is not critical operation.
+ * If a given segment is one of current working segments, it won't be added.
+ */
+static void locate_dirty_segment(struct f2fs_sb_info *sbi, unsigned int segno)
+{
+	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
+	unsigned short valid_blocks;
+
+	if (segno == NULL_SEGNO || IS_CURSEG(sbi, segno))
+		return;
+
+	mutex_lock(&dirty_i->seglist_lock);
+
+	valid_blocks = get_valid_blocks(sbi, segno, false);
+
+	if (valid_blocks == 0) {
+		__locate_dirty_segment(sbi, segno, PRE);
+		__remove_dirty_segment(sbi, segno, DIRTY);
+	} else if (valid_blocks < sbi->blocks_per_seg) {
+		__locate_dirty_segment(sbi, segno, DIRTY);
+	} else {
+		/* Recovery routine with SSR needs this */
+		__remove_dirty_segment(sbi, segno, DIRTY);
+	}
+
+	mutex_unlock(&dirty_i->seglist_lock);
+}
+
+static struct discard_cmd *__create_discard_cmd(struct f2fs_sb_info *sbi,
+		struct block_device *bdev, block_t lstart,
+		block_t start, block_t len)
+{
+	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
+	struct list_head *pend_list;
+	struct discard_cmd *dc;
+
+	f2fs_bug_on(sbi, !len);
+
+	pend_list = &dcc->pend_list[plist_idx(len)];
+
+	dc = f2fs_kmem_cache_alloc(discard_cmd_slab, GFP_NOFS);
+	INIT_LIST_HEAD(&dc->list);
+	dc->bdev = bdev;
+	dc->lstart = lstart;
+	dc->start = start;
+	dc->len = len;
+	dc->ref = 0;
+	dc->state = D_PREP;
+	dc->error = 0;
+	init_completion(&dc->wait);
+	list_add_tail(&dc->list, pend_list);
+	atomic_inc(&dcc->discard_cmd_cnt);
+	dcc->undiscard_blks += len;
+
+	return dc;
+}
+
+static struct discard_cmd *__attach_discard_cmd(struct f2fs_sb_info *sbi,
+				struct block_device *bdev, block_t lstart,
+				block_t start, block_t len,
+				struct rb_node *parent, struct rb_node **p)
+{
+	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
+	struct discard_cmd *dc;
+
+	dc = __create_discard_cmd(sbi, bdev, lstart, start, len);
+
+	rb_link_node(&dc->rb_node, parent, p);
+	rb_insert_color(&dc->rb_node, &dcc->root);
+
+	return dc;
+}
+
+static void __detach_discard_cmd(struct discard_cmd_control *dcc,
+							struct discard_cmd *dc)
+{
+	if (dc->state == D_DONE)
+		atomic_dec(&dcc->issing_discard);
+
+	list_del(&dc->list);
+	rb_erase(&dc->rb_node, &dcc->root);
+	dcc->undiscard_blks -= dc->len;
+
+	kmem_cache_free(discard_cmd_slab, dc);
+
+	atomic_dec(&dcc->discard_cmd_cnt);
+}
+
+static void __remove_discard_cmd(struct f2fs_sb_info *sbi,
+							struct discard_cmd *dc)
+{
+	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
+
+	trace_f2fs_remove_discard(dc->bdev, dc->start, dc->len);
+
+	f2fs_bug_on(sbi, dc->ref);
+
+	if (dc->error == -EOPNOTSUPP)
+		dc->error = 0;
+
+	if (dc->error)
+		f2fs_msg(sbi->sb, KERN_INFO,
+			"Issue discard(%u, %u, %u) failed, ret: %d",
+			dc->lstart, dc->start, dc->len, dc->error);
+	__detach_discard_cmd(dcc, dc);
+}
+
+static void f2fs_submit_discard_endio(struct bio *bio)
+{
+	struct discard_cmd *dc = (struct discard_cmd *)bio->bi_private;
+
+	dc->error = blk_status_to_errno(bio->bi_status);
+	dc->state = D_DONE;
+	complete_all(&dc->wait);
+	bio_put(bio);
+}
+
+static void __check_sit_bitmap(struct f2fs_sb_info *sbi,
+				block_t start, block_t end)
+{
+#ifdef CONFIG_F2FS_CHECK_FS
+	struct seg_entry *sentry;
+	unsigned int segno;
+	block_t blk = start;
+	unsigned long offset, size, max_blocks = sbi->blocks_per_seg;
+	unsigned long *map;
+
+	while (blk < end) {
+		segno = GET_SEGNO(sbi, blk);
+		sentry = get_seg_entry(sbi, segno);
+		offset = GET_BLKOFF_FROM_SEG0(sbi, blk);
+
+		if (end < START_BLOCK(sbi, segno + 1))
+			size = GET_BLKOFF_FROM_SEG0(sbi, end);
+		else
+			size = max_blocks;
+		map = (unsigned long *)(sentry->cur_valid_map);
+		offset = __find_rev_next_bit(map, size, offset);
+		f2fs_bug_on(sbi, offset != size);
+		blk = START_BLOCK(sbi, segno + 1);
+	}
+#endif
+}
+
+static void __init_discard_policy(struct f2fs_sb_info *sbi,
+				struct discard_policy *dpolicy,
+				int discard_type, unsigned int granularity)
+{
+	/* common policy */
+	dpolicy->type = discard_type;
+	dpolicy->sync = true;
+	dpolicy->granularity = granularity;
+
+	dpolicy->max_requests = DEF_MAX_DISCARD_REQUEST;
+	dpolicy->io_aware_gran = MAX_PLIST_NUM;
+
+	if (discard_type == DPOLICY_BG) {
+		dpolicy->min_interval = DEF_MIN_DISCARD_ISSUE_TIME;
+		dpolicy->max_interval = DEF_MAX_DISCARD_ISSUE_TIME;
+		dpolicy->io_aware = true;
+		dpolicy->sync = false;
+		if (utilization(sbi) > DEF_DISCARD_URGENT_UTIL) {
+			dpolicy->granularity = 1;
+			dpolicy->max_interval = DEF_MIN_DISCARD_ISSUE_TIME;
+		}
+	} else if (discard_type == DPOLICY_FORCE) {
+		dpolicy->min_interval = DEF_MIN_DISCARD_ISSUE_TIME;
+		dpolicy->max_interval = DEF_MAX_DISCARD_ISSUE_TIME;
+		dpolicy->io_aware = false;
+	} else if (discard_type == DPOLICY_FSTRIM) {
+		dpolicy->io_aware = false;
+	} else if (discard_type == DPOLICY_UMOUNT) {
+		dpolicy->io_aware = false;
+	}
+}
+
+
+/* this function is copied from blkdev_issue_discard from block/blk-lib.c */
+static void __submit_discard_cmd(struct f2fs_sb_info *sbi,
+						struct discard_policy *dpolicy,
+						struct discard_cmd *dc)
+{
+	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
+	struct list_head *wait_list = (dpolicy->type == DPOLICY_FSTRIM) ?
+					&(dcc->fstrim_list) : &(dcc->wait_list);
+	struct bio *bio = NULL;
+	int flag = dpolicy->sync ? REQ_SYNC : 0;
+
+	if (dc->state != D_PREP)
+		return;
+
+	trace_f2fs_issue_discard(dc->bdev, dc->start, dc->len);
+
+	dc->error = __blkdev_issue_discard(dc->bdev,
+				SECTOR_FROM_BLOCK(dc->start),
+				SECTOR_FROM_BLOCK(dc->len),
+				GFP_NOFS, 0, &bio);
+	if (!dc->error) {
+		/* should keep before submission to avoid D_DONE right away */
+		dc->state = D_SUBMIT;
+		atomic_inc(&dcc->issued_discard);
+		atomic_inc(&dcc->issing_discard);
+		if (bio) {
+			bio->bi_private = dc;
+			bio->bi_end_io = f2fs_submit_discard_endio;
+			bio->bi_opf |= flag;
+			submit_bio(bio);
+			list_move_tail(&dc->list, wait_list);
+			__check_sit_bitmap(sbi, dc->start, dc->start + dc->len);
+
+			f2fs_update_iostat(sbi, FS_DISCARD, 1);
+		}
+	} else {
+		__remove_discard_cmd(sbi, dc);
+	}
+}
+
+static struct discard_cmd *__insert_discard_tree(struct f2fs_sb_info *sbi,
+				struct block_device *bdev, block_t lstart,
+				block_t start, block_t len,
+				struct rb_node **insert_p,
+				struct rb_node *insert_parent)
+{
+	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
+	struct rb_node **p;
+	struct rb_node *parent = NULL;
+	struct discard_cmd *dc = NULL;
+
+	if (insert_p && insert_parent) {
+		parent = insert_parent;
+		p = insert_p;
+		goto do_insert;
+	}
+
+	p = __lookup_rb_tree_for_insert(sbi, &dcc->root, &parent, lstart);
+do_insert:
+	dc = __attach_discard_cmd(sbi, bdev, lstart, start, len, parent, p);
+	if (!dc)
+		return NULL;
+
+	return dc;
+}
+
+static void __relocate_discard_cmd(struct discard_cmd_control *dcc,
+						struct discard_cmd *dc)
+{
+	list_move_tail(&dc->list, &dcc->pend_list[plist_idx(dc->len)]);
+}
+
+static void __punch_discard_cmd(struct f2fs_sb_info *sbi,
+				struct discard_cmd *dc, block_t blkaddr)
+{
+	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
+	struct discard_info di = dc->di;
+	bool modified = false;
+
+	if (dc->state == D_DONE || dc->len == 1) {
+		__remove_discard_cmd(sbi, dc);
+		return;
+	}
+
+	dcc->undiscard_blks -= di.len;
+
+	if (blkaddr > di.lstart) {
+		dc->len = blkaddr - dc->lstart;
+		dcc->undiscard_blks += dc->len;
+		__relocate_discard_cmd(dcc, dc);
+		modified = true;
+	}
+
+	if (blkaddr < di.lstart + di.len - 1) {
+		if (modified) {
+			__insert_discard_tree(sbi, dc->bdev, blkaddr + 1,
+					di.start + blkaddr + 1 - di.lstart,
+					di.lstart + di.len - 1 - blkaddr,
+					NULL, NULL);
+		} else {
+			dc->lstart++;
+			dc->len--;
+			dc->start++;
+			dcc->undiscard_blks += dc->len;
+			__relocate_discard_cmd(dcc, dc);
+		}
+	}
+}
+
+static void __update_discard_tree_range(struct f2fs_sb_info *sbi,
+				struct block_device *bdev, block_t lstart,
+				block_t start, block_t len)
+{
+	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
+	struct discard_cmd *prev_dc = NULL, *next_dc = NULL;
+	struct discard_cmd *dc;
+	struct discard_info di = {0};
+	struct rb_node **insert_p = NULL, *insert_parent = NULL;
+	block_t end = lstart + len;
+
+	mutex_lock(&dcc->cmd_lock);
+
+	dc = (struct discard_cmd *)__lookup_rb_tree_ret(&dcc->root,
+					NULL, lstart,
+					(struct rb_entry **)&prev_dc,
+					(struct rb_entry **)&next_dc,
+					&insert_p, &insert_parent, true);
+	if (dc)
+		prev_dc = dc;
+
+	if (!prev_dc) {
+		di.lstart = lstart;
+		di.len = next_dc ? next_dc->lstart - lstart : len;
+		di.len = min(di.len, len);
+		di.start = start;
+	}
+
+	while (1) {
+		struct rb_node *node;
+		bool merged = false;
+		struct discard_cmd *tdc = NULL;
+
+		if (prev_dc) {
+			di.lstart = prev_dc->lstart + prev_dc->len;
+			if (di.lstart < lstart)
+				di.lstart = lstart;
+			if (di.lstart >= end)
+				break;
+
+			if (!next_dc || next_dc->lstart > end)
+				di.len = end - di.lstart;
+			else
+				di.len = next_dc->lstart - di.lstart;
+			di.start = start + di.lstart - lstart;
+		}
+
+		if (!di.len)
+			goto next;
+
+		if (prev_dc && prev_dc->state == D_PREP &&
+			prev_dc->bdev == bdev &&
+			__is_discard_back_mergeable(&di, &prev_dc->di)) {
+			prev_dc->di.len += di.len;
+			dcc->undiscard_blks += di.len;
+			__relocate_discard_cmd(dcc, prev_dc);
+			di = prev_dc->di;
+			tdc = prev_dc;
+			merged = true;
+		}
+
+		if (next_dc && next_dc->state == D_PREP &&
+			next_dc->bdev == bdev &&
+			__is_discard_front_mergeable(&di, &next_dc->di)) {
+			next_dc->di.lstart = di.lstart;
+			next_dc->di.len += di.len;
+			next_dc->di.start = di.start;
+			dcc->undiscard_blks += di.len;
+			__relocate_discard_cmd(dcc, next_dc);
+			if (tdc)
+				__remove_discard_cmd(sbi, tdc);
+			merged = true;
+		}
+
+		if (!merged) {
+			__insert_discard_tree(sbi, bdev, di.lstart, di.start,
+							di.len, NULL, NULL);
+		}
+ next:
+		prev_dc = next_dc;
+		if (!prev_dc)
+			break;
+
+		node = rb_next(&prev_dc->rb_node);
+		next_dc = rb_entry_safe(node, struct discard_cmd, rb_node);
+	}
+
+	mutex_unlock(&dcc->cmd_lock);
+}
+
+static int __queue_discard_cmd(struct f2fs_sb_info *sbi,
+		struct block_device *bdev, block_t blkstart, block_t blklen)
+{
+	block_t lblkstart = blkstart;
+
+	trace_f2fs_queue_discard(bdev, blkstart, blklen);
+
+	if (f2fs_is_multi_device(sbi)) {
+		int devi = f2fs_target_device_index(sbi, blkstart);
+
+		blkstart -= FDEV(devi).start_blk;
+	}
+	__update_discard_tree_range(sbi, bdev, lblkstart, blkstart, blklen);
+	return 0;
+}
+
+static int __issue_discard_cmd(struct f2fs_sb_info *sbi,
+					struct discard_policy *dpolicy)
+{
+	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
+	struct list_head *pend_list;
+	struct discard_cmd *dc, *tmp;
+	struct blk_plug plug;
+	int i, iter = 0, issued = 0;
+	bool io_interrupted = false;
+
+	for (i = MAX_PLIST_NUM - 1; i >= 0; i--) {
+		if (i + 1 < dpolicy->granularity)
+			break;
+		pend_list = &dcc->pend_list[i];
+
+		mutex_lock(&dcc->cmd_lock);
+		if (list_empty(pend_list))
+			goto next;
+		f2fs_bug_on(sbi, !__check_rb_tree_consistence(sbi, &dcc->root));
+		blk_start_plug(&plug);
+		list_for_each_entry_safe(dc, tmp, pend_list, list) {
+			f2fs_bug_on(sbi, dc->state != D_PREP);
+
+			if (dpolicy->io_aware && i < dpolicy->io_aware_gran &&
+								!is_idle(sbi)) {
+				io_interrupted = true;
+				goto skip;
+			}
+
+			__submit_discard_cmd(sbi, dpolicy, dc);
+			issued++;
+skip:
+			if (++iter >= dpolicy->max_requests)
+				break;
+		}
+		blk_finish_plug(&plug);
+next:
+		mutex_unlock(&dcc->cmd_lock);
+
+		if (iter >= dpolicy->max_requests)
+			break;
+	}
+
+	if (!issued && io_interrupted)
+		issued = -1;
+
+	return issued;
+}
+
+static bool __drop_discard_cmd(struct f2fs_sb_info *sbi)
+{
+	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
+	struct list_head *pend_list;
+	struct discard_cmd *dc, *tmp;
+	int i;
+	bool dropped = false;
+
+	mutex_lock(&dcc->cmd_lock);
+	for (i = MAX_PLIST_NUM - 1; i >= 0; i--) {
+		pend_list = &dcc->pend_list[i];
+		list_for_each_entry_safe(dc, tmp, pend_list, list) {
+			f2fs_bug_on(sbi, dc->state != D_PREP);
+			__remove_discard_cmd(sbi, dc);
+			dropped = true;
+		}
+	}
+	mutex_unlock(&dcc->cmd_lock);
+
+	return dropped;
+}
+
+void drop_discard_cmd(struct f2fs_sb_info *sbi)
+{
+	__drop_discard_cmd(sbi);
+}
+
+static unsigned int __wait_one_discard_bio(struct f2fs_sb_info *sbi,
+							struct discard_cmd *dc)
+{
+	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
+	unsigned int len = 0;
+
+	wait_for_completion_io(&dc->wait);
+	mutex_lock(&dcc->cmd_lock);
+	f2fs_bug_on(sbi, dc->state != D_DONE);
+	dc->ref--;
+	if (!dc->ref) {
+		if (!dc->error)
+			len = dc->len;
+		__remove_discard_cmd(sbi, dc);
+	}
+	mutex_unlock(&dcc->cmd_lock);
+
+	return len;
+}
+
+static unsigned int __wait_discard_cmd_range(struct f2fs_sb_info *sbi,
+						struct discard_policy *dpolicy,
+						block_t start, block_t end)
+{
+	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
+	struct list_head *wait_list = (dpolicy->type == DPOLICY_FSTRIM) ?
+					&(dcc->fstrim_list) : &(dcc->wait_list);
+	struct discard_cmd *dc, *tmp;
+	bool need_wait;
+	unsigned int trimmed = 0;
+
+next:
+	need_wait = false;
+
+	mutex_lock(&dcc->cmd_lock);
+	list_for_each_entry_safe(dc, tmp, wait_list, list) {
+		if (dc->lstart + dc->len <= start || end <= dc->lstart)
+			continue;
+		if (dc->len < dpolicy->granularity)
+			continue;
+		if (dc->state == D_DONE && !dc->ref) {
+			wait_for_completion_io(&dc->wait);
+			if (!dc->error)
+				trimmed += dc->len;
+			__remove_discard_cmd(sbi, dc);
+		} else {
+			dc->ref++;
+			need_wait = true;
+			break;
+		}
+	}
+	mutex_unlock(&dcc->cmd_lock);
+
+	if (need_wait) {
+		trimmed += __wait_one_discard_bio(sbi, dc);
+		goto next;
+	}
+
+	return trimmed;
+}
+
+static void __wait_all_discard_cmd(struct f2fs_sb_info *sbi,
+						struct discard_policy *dpolicy)
+{
+	struct discard_policy dp;
+
+	if (dpolicy) {
+		__wait_discard_cmd_range(sbi, dpolicy, 0, UINT_MAX);
+		return;
+	}
+
+	/* wait all */
+	__init_discard_policy(sbi, &dp, DPOLICY_FSTRIM, 1);
+	__wait_discard_cmd_range(sbi, &dp, 0, UINT_MAX);
+	__init_discard_policy(sbi, &dp, DPOLICY_UMOUNT, 1);
+	__wait_discard_cmd_range(sbi, &dp, 0, UINT_MAX);
+}
+
+/* This should be covered by global mutex, &sit_i->sentry_lock */
+static void f2fs_wait_discard_bio(struct f2fs_sb_info *sbi, block_t blkaddr)
+{
+	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
+	struct discard_cmd *dc;
+	bool need_wait = false;
+
+	mutex_lock(&dcc->cmd_lock);
+	dc = (struct discard_cmd *)__lookup_rb_tree(&dcc->root, NULL, blkaddr);
+	if (dc) {
+		if (dc->state == D_PREP) {
+			__punch_discard_cmd(sbi, dc, blkaddr);
+		} else {
+			dc->ref++;
+			need_wait = true;
+		}
+	}
+	mutex_unlock(&dcc->cmd_lock);
+
+	if (need_wait)
+		__wait_one_discard_bio(sbi, dc);
+}
+
+void stop_discard_thread(struct f2fs_sb_info *sbi)
+{
+	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
+
+	if (dcc && dcc->f2fs_issue_discard) {
+		struct task_struct *discard_thread = dcc->f2fs_issue_discard;
+
+		dcc->f2fs_issue_discard = NULL;
+		kthread_stop(discard_thread);
+	}
+}
+
+/* This comes from f2fs_put_super */
+bool f2fs_wait_discard_bios(struct f2fs_sb_info *sbi)
+{
+	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
+	struct discard_policy dpolicy;
+	bool dropped;
+
+	__init_discard_policy(sbi, &dpolicy, DPOLICY_UMOUNT,
+					dcc->discard_granularity);
+	__issue_discard_cmd(sbi, &dpolicy);
+	dropped = __drop_discard_cmd(sbi);
+
+	/* just to make sure there is no pending discard commands */
+	__wait_all_discard_cmd(sbi, NULL);
+	return dropped;
+}
+
+static int issue_discard_thread(void *data)
+{
+	struct f2fs_sb_info *sbi = data;
+	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
+	wait_queue_head_t *q = &dcc->discard_wait_queue;
+	struct discard_policy dpolicy;
+	unsigned int wait_ms = DEF_MIN_DISCARD_ISSUE_TIME;
+	int issued;
+
+	set_freezable();
+
+	do {
+		__init_discard_policy(sbi, &dpolicy, DPOLICY_BG,
+					dcc->discard_granularity);
+
+		wait_event_interruptible_timeout(*q,
+				kthread_should_stop() || freezing(current) ||
+				dcc->discard_wake,
+				msecs_to_jiffies(wait_ms));
+		if (try_to_freeze())
+			continue;
+		if (f2fs_readonly(sbi->sb))
+			continue;
+		if (kthread_should_stop())
+			return 0;
+
+		if (dcc->discard_wake)
+			dcc->discard_wake = 0;
+
+		if (sbi->gc_thread && sbi->gc_thread->gc_urgent)
+			__init_discard_policy(sbi, &dpolicy, DPOLICY_FORCE, 1);
+
+		sb_start_intwrite(sbi->sb);
+
+		issued = __issue_discard_cmd(sbi, &dpolicy);
+		if (issued) {
+			__wait_all_discard_cmd(sbi, &dpolicy);
+			wait_ms = dpolicy.min_interval;
+		} else {
+			wait_ms = dpolicy.max_interval;
+		}
+
+		sb_end_intwrite(sbi->sb);
+
+	} while (!kthread_should_stop());
+	return 0;
+}
+
+#ifdef CONFIG_BLK_DEV_ZONED
+static int __f2fs_issue_discard_zone(struct f2fs_sb_info *sbi,
+		struct block_device *bdev, block_t blkstart, block_t blklen)
+{
+	sector_t sector, nr_sects;
+	block_t lblkstart = blkstart;
+	int devi = 0;
+
+	if (f2fs_is_multi_device(sbi)) {
+		devi = f2fs_target_device_index(sbi, blkstart);
+		blkstart -= FDEV(devi).start_blk;
+	}
+
+	/*
+	 * We need to know the type of the zone: for conventional zones,
+	 * use regular discard if the drive supports it. For sequential
+	 * zones, reset the zone write pointer.
+	 */
+	switch (get_blkz_type(sbi, bdev, blkstart)) {
+
+	case BLK_ZONE_TYPE_CONVENTIONAL:
+		if (!blk_queue_discard(bdev_get_queue(bdev)))
+			return 0;
+		return __queue_discard_cmd(sbi, bdev, lblkstart, blklen);
+	case BLK_ZONE_TYPE_SEQWRITE_REQ:
+	case BLK_ZONE_TYPE_SEQWRITE_PREF:
+		sector = SECTOR_FROM_BLOCK(blkstart);
+		nr_sects = SECTOR_FROM_BLOCK(blklen);
+
+		if (sector & (bdev_zone_sectors(bdev) - 1) ||
+				nr_sects != bdev_zone_sectors(bdev)) {
+			f2fs_msg(sbi->sb, KERN_INFO,
+				"(%d) %s: Unaligned discard attempted (block %x + %x)",
+				devi, sbi->s_ndevs ? FDEV(devi).path: "",
+				blkstart, blklen);
+			return -EIO;
+		}
+		trace_f2fs_issue_reset_zone(bdev, blkstart);
+		return blkdev_reset_zones(bdev, sector,
+					  nr_sects, GFP_NOFS);
+	default:
+		/* Unknown zone type: broken device ? */
+		return -EIO;
+	}
+}
+#endif
+
+static int __issue_discard_async(struct f2fs_sb_info *sbi,
+		struct block_device *bdev, block_t blkstart, block_t blklen)
+{
+#ifdef CONFIG_BLK_DEV_ZONED
+	if (f2fs_sb_has_blkzoned(sbi->sb) &&
+				bdev_zoned_model(bdev) != BLK_ZONED_NONE)
+		return __f2fs_issue_discard_zone(sbi, bdev, blkstart, blklen);
+#endif
+	return __queue_discard_cmd(sbi, bdev, blkstart, blklen);
+}
+
+static int f2fs_issue_discard(struct f2fs_sb_info *sbi,
+				block_t blkstart, block_t blklen)
+{
+	sector_t start = blkstart, len = 0;
+	struct block_device *bdev;
+	struct seg_entry *se;
+	unsigned int offset;
+	block_t i;
+	int err = 0;
+
+	bdev = f2fs_target_device(sbi, blkstart, NULL);
+
+	for (i = blkstart; i < blkstart + blklen; i++, len++) {
+		if (i != start) {
+			struct block_device *bdev2 =
+				f2fs_target_device(sbi, i, NULL);
+
+			if (bdev2 != bdev) {
+				err = __issue_discard_async(sbi, bdev,
+						start, len);
+				if (err)
+					return err;
+				bdev = bdev2;
+				start = i;
+				len = 0;
+			}
+		}
+
+		se = get_seg_entry(sbi, GET_SEGNO(sbi, i));
+		offset = GET_BLKOFF_FROM_SEG0(sbi, i);
+
+		if (!f2fs_test_and_set_bit(offset, se->discard_map))
+			sbi->discard_blks--;
+	}
+
+	if (len)
+		err = __issue_discard_async(sbi, bdev, start, len);
+	return err;
+}
+
+static bool add_discard_addrs(struct f2fs_sb_info *sbi, struct cp_control *cpc,
+							bool check_only)
+{
+	int entries = SIT_VBLOCK_MAP_SIZE / sizeof(unsigned long);
+	int max_blocks = sbi->blocks_per_seg;
+	struct seg_entry *se = get_seg_entry(sbi, cpc->trim_start);
+	unsigned long *cur_map = (unsigned long *)se->cur_valid_map;
+	unsigned long *ckpt_map = (unsigned long *)se->ckpt_valid_map;
+	unsigned long *discard_map = (unsigned long *)se->discard_map;
+	unsigned long *dmap = SIT_I(sbi)->tmp_map;
+	unsigned int start = 0, end = -1;
+	bool force = (cpc->reason & CP_DISCARD);
+	struct discard_entry *de = NULL;
+	struct list_head *head = &SM_I(sbi)->dcc_info->entry_list;
+	int i;
+
+	if (se->valid_blocks == max_blocks || !f2fs_discard_en(sbi))
+		return false;
+
+	if (!force) {
+		if (!test_opt(sbi, DISCARD) || !se->valid_blocks ||
+			SM_I(sbi)->dcc_info->nr_discards >=
+				SM_I(sbi)->dcc_info->max_discards)
+			return false;
+	}
+
+	/* SIT_VBLOCK_MAP_SIZE should be multiple of sizeof(unsigned long) */
+	for (i = 0; i < entries; i++)
+		dmap[i] = force ? ~ckpt_map[i] & ~discard_map[i] :
+				(cur_map[i] ^ ckpt_map[i]) & ckpt_map[i];
+
+	while (force || SM_I(sbi)->dcc_info->nr_discards <=
+				SM_I(sbi)->dcc_info->max_discards) {
+		start = __find_rev_next_bit(dmap, max_blocks, end + 1);
+		if (start >= max_blocks)
+			break;
+
+		end = __find_rev_next_zero_bit(dmap, max_blocks, start + 1);
+		if (force && start && end != max_blocks
+					&& (end - start) < cpc->trim_minlen)
+			continue;
+
+		if (check_only)
+			return true;
+
+		if (!de) {
+			de = f2fs_kmem_cache_alloc(discard_entry_slab,
+								GFP_F2FS_ZERO);
+			de->start_blkaddr = START_BLOCK(sbi, cpc->trim_start);
+			list_add_tail(&de->list, head);
+		}
+
+		for (i = start; i < end; i++)
+			__set_bit_le(i, (void *)de->discard_map);
+
+		SM_I(sbi)->dcc_info->nr_discards += end - start;
+	}
+	return false;
+}
+
+void release_discard_addrs(struct f2fs_sb_info *sbi)
+{
+	struct list_head *head = &(SM_I(sbi)->dcc_info->entry_list);
+	struct discard_entry *entry, *this;
+
+	/* drop caches */
+	list_for_each_entry_safe(entry, this, head, list) {
+		list_del(&entry->list);
+		kmem_cache_free(discard_entry_slab, entry);
+	}
+}
+
+/*
+ * Should call clear_prefree_segments after checkpoint is done.
+ */
+static void set_prefree_as_free_segments(struct f2fs_sb_info *sbi)
+{
+	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
+	unsigned int segno;
+
+	mutex_lock(&dirty_i->seglist_lock);
+	for_each_set_bit(segno, dirty_i->dirty_segmap[PRE], MAIN_SEGS(sbi))
+		__set_test_and_free(sbi, segno);
+	mutex_unlock(&dirty_i->seglist_lock);
+}
+
+void clear_prefree_segments(struct f2fs_sb_info *sbi, struct cp_control *cpc)
+{
+	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
+	struct list_head *head = &dcc->entry_list;
+	struct discard_entry *entry, *this;
+	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
+	unsigned long *prefree_map = dirty_i->dirty_segmap[PRE];
+	unsigned int start = 0, end = -1;
+	unsigned int secno, start_segno;
+	bool force = (cpc->reason & CP_DISCARD);
+
+	mutex_lock(&dirty_i->seglist_lock);
+
+	while (1) {
+		int i;
+		start = find_next_bit(prefree_map, MAIN_SEGS(sbi), end + 1);
+		if (start >= MAIN_SEGS(sbi))
+			break;
+		end = find_next_zero_bit(prefree_map, MAIN_SEGS(sbi),
+								start + 1);
+
+		for (i = start; i < end; i++)
+			clear_bit(i, prefree_map);
+
+		dirty_i->nr_dirty[PRE] -= end - start;
+
+		if (!test_opt(sbi, DISCARD))
+			continue;
+
+		if (force && start >= cpc->trim_start &&
+					(end - 1) <= cpc->trim_end)
+				continue;
+
+		if (!test_opt(sbi, LFS) || sbi->segs_per_sec == 1) {
+			f2fs_issue_discard(sbi, START_BLOCK(sbi, start),
+				(end - start) << sbi->log_blocks_per_seg);
+			continue;
+		}
+next:
+		secno = GET_SEC_FROM_SEG(sbi, start);
+		start_segno = GET_SEG_FROM_SEC(sbi, secno);
+		if (!IS_CURSEC(sbi, secno) &&
+			!get_valid_blocks(sbi, start, true))
+			f2fs_issue_discard(sbi, START_BLOCK(sbi, start_segno),
+				sbi->segs_per_sec << sbi->log_blocks_per_seg);
+
+		start = start_segno + sbi->segs_per_sec;
+		if (start < end)
+			goto next;
+		else
+			end = start - 1;
+	}
+	mutex_unlock(&dirty_i->seglist_lock);
+
+	/* send small discards */
+	list_for_each_entry_safe(entry, this, head, list) {
+		unsigned int cur_pos = 0, next_pos, len, total_len = 0;
+		bool is_valid = test_bit_le(0, entry->discard_map);
+
+find_next:
+		if (is_valid) {
+			next_pos = find_next_zero_bit_le(entry->discard_map,
+					sbi->blocks_per_seg, cur_pos);
+			len = next_pos - cur_pos;
+
+			if (f2fs_sb_has_blkzoned(sbi->sb) ||
+			    (force && len < cpc->trim_minlen))
+				goto skip;
+
+			f2fs_issue_discard(sbi, entry->start_blkaddr + cur_pos,
+									len);
+			total_len += len;
+		} else {
+			next_pos = find_next_bit_le(entry->discard_map,
+					sbi->blocks_per_seg, cur_pos);
+		}
+skip:
+		cur_pos = next_pos;
+		is_valid = !is_valid;
+
+		if (cur_pos < sbi->blocks_per_seg)
+			goto find_next;
+
+		list_del(&entry->list);
+		dcc->nr_discards -= total_len;
+		kmem_cache_free(discard_entry_slab, entry);
+	}
+
+	wake_up_discard_thread(sbi, false);
+}
+
+static int create_discard_cmd_control(struct f2fs_sb_info *sbi)
+{
+	dev_t dev = sbi->sb->s_bdev->bd_dev;
+	struct discard_cmd_control *dcc;
+	int err = 0, i;
+
+	if (SM_I(sbi)->dcc_info) {
+		dcc = SM_I(sbi)->dcc_info;
+		goto init_thread;
+	}
+
+	dcc = f2fs_kzalloc(sbi, sizeof(struct discard_cmd_control), GFP_KERNEL);
+	if (!dcc)
+		return -ENOMEM;
+
+	dcc->discard_granularity = DEFAULT_DISCARD_GRANULARITY;
+	INIT_LIST_HEAD(&dcc->entry_list);
+	for (i = 0; i < MAX_PLIST_NUM; i++)
+		INIT_LIST_HEAD(&dcc->pend_list[i]);
+	INIT_LIST_HEAD(&dcc->wait_list);
+	INIT_LIST_HEAD(&dcc->fstrim_list);
+	mutex_init(&dcc->cmd_lock);
+	atomic_set(&dcc->issued_discard, 0);
+	atomic_set(&dcc->issing_discard, 0);
+	atomic_set(&dcc->discard_cmd_cnt, 0);
+	dcc->nr_discards = 0;
+	dcc->max_discards = MAIN_SEGS(sbi) << sbi->log_blocks_per_seg;
+	dcc->undiscard_blks = 0;
+	dcc->root = RB_ROOT;
+
+	init_waitqueue_head(&dcc->discard_wait_queue);
+	SM_I(sbi)->dcc_info = dcc;
+init_thread:
+	dcc->f2fs_issue_discard = kthread_run(issue_discard_thread, sbi,
+				"f2fs_discard-%u:%u", MAJOR(dev), MINOR(dev));
+	if (IS_ERR(dcc->f2fs_issue_discard)) {
+		err = PTR_ERR(dcc->f2fs_issue_discard);
+		kfree(dcc);
+		SM_I(sbi)->dcc_info = NULL;
+		return err;
+	}
+
+	return err;
+}
+
+static void destroy_discard_cmd_control(struct f2fs_sb_info *sbi)
+{
+	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
+
+	if (!dcc)
+		return;
+
+	stop_discard_thread(sbi);
+
+	kfree(dcc);
+	SM_I(sbi)->dcc_info = NULL;
+}
+
+static bool __mark_sit_entry_dirty(struct f2fs_sb_info *sbi, unsigned int segno)
+{
+	struct sit_info *sit_i = SIT_I(sbi);
+
+	if (!__test_and_set_bit(segno, sit_i->dirty_sentries_bitmap)) {
+		sit_i->dirty_sentries++;
+		return false;
+	}
+
+	return true;
+}
+
+static void __set_sit_entry_type(struct f2fs_sb_info *sbi, int type,
+					unsigned int segno, int modified)
+{
+	struct seg_entry *se = get_seg_entry(sbi, segno);
+	se->type = type;
+	if (modified)
+		__mark_sit_entry_dirty(sbi, segno);
+}
+
+static void update_sit_entry(struct f2fs_sb_info *sbi, block_t blkaddr, int del)
+{
+	struct seg_entry *se;
+	unsigned int segno, offset;
+	long int new_vblocks;
+	bool exist;
+#ifdef CONFIG_F2FS_CHECK_FS
+	bool mir_exist;
+#endif
+
+	segno = GET_SEGNO(sbi, blkaddr);
+
+	se = get_seg_entry(sbi, segno);
+	new_vblocks = se->valid_blocks + del;
+	offset = GET_BLKOFF_FROM_SEG0(sbi, blkaddr);
+
+	f2fs_bug_on(sbi, (new_vblocks >> (sizeof(unsigned short) << 3) ||
+				(new_vblocks > sbi->blocks_per_seg)));
+
+	se->valid_blocks = new_vblocks;
+	se->mtime = get_mtime(sbi);
+	SIT_I(sbi)->max_mtime = se->mtime;
+
+	/* Update valid block bitmap */
+	if (del > 0) {
+		exist = f2fs_test_and_set_bit(offset, se->cur_valid_map);
+#ifdef CONFIG_F2FS_CHECK_FS
+		mir_exist = f2fs_test_and_set_bit(offset,
+						se->cur_valid_map_mir);
+		if (unlikely(exist != mir_exist)) {
+			f2fs_msg(sbi->sb, KERN_ERR, "Inconsistent error "
+				"when setting bitmap, blk:%u, old bit:%d",
+				blkaddr, exist);
+			f2fs_bug_on(sbi, 1);
+		}
+#endif
+		if (unlikely(exist)) {
+			f2fs_msg(sbi->sb, KERN_ERR,
+				"Bitmap was wrongly set, blk:%u", blkaddr);
+			f2fs_bug_on(sbi, 1);
+			se->valid_blocks--;
+			del = 0;
+		}
+
+		if (f2fs_discard_en(sbi) &&
+			!f2fs_test_and_set_bit(offset, se->discard_map))
+			sbi->discard_blks--;
+
+		/* don't overwrite by SSR to keep node chain */
+		if (IS_NODESEG(se->type)) {
+			if (!f2fs_test_and_set_bit(offset, se->ckpt_valid_map))
+				se->ckpt_valid_blocks++;
+		}
+	} else {
+		exist = f2fs_test_and_clear_bit(offset, se->cur_valid_map);
+#ifdef CONFIG_F2FS_CHECK_FS
+		mir_exist = f2fs_test_and_clear_bit(offset,
+						se->cur_valid_map_mir);
+		if (unlikely(exist != mir_exist)) {
+			f2fs_msg(sbi->sb, KERN_ERR, "Inconsistent error "
+				"when clearing bitmap, blk:%u, old bit:%d",
+				blkaddr, exist);
+			f2fs_bug_on(sbi, 1);
+		}
+#endif
+		if (unlikely(!exist)) {
+			f2fs_msg(sbi->sb, KERN_ERR,
+				"Bitmap was wrongly cleared, blk:%u", blkaddr);
+			f2fs_bug_on(sbi, 1);
+			se->valid_blocks++;
+			del = 0;
+		}
+
+		if (f2fs_discard_en(sbi) &&
+			f2fs_test_and_clear_bit(offset, se->discard_map))
+			sbi->discard_blks++;
+	}
+	if (!f2fs_test_bit(offset, se->ckpt_valid_map))
+		se->ckpt_valid_blocks += del;
+
+	__mark_sit_entry_dirty(sbi, segno);
+
+	/* update total number of valid blocks to be written in ckpt area */
+	SIT_I(sbi)->written_valid_blocks += del;
+
+	if (sbi->segs_per_sec > 1)
+		get_sec_entry(sbi, segno)->valid_blocks += del;
+}
+
+void invalidate_blocks(struct f2fs_sb_info *sbi, block_t addr)
+{
+	unsigned int segno = GET_SEGNO(sbi, addr);
+	struct sit_info *sit_i = SIT_I(sbi);
+
+	f2fs_bug_on(sbi, addr == NULL_ADDR);
+	if (addr == NEW_ADDR)
+		return;
+
+	/* add it into sit main buffer */
+	down_write(&sit_i->sentry_lock);
+
+	update_sit_entry(sbi, addr, -1);
+
+	/* add it into dirty seglist */
+	locate_dirty_segment(sbi, segno);
+
+	up_write(&sit_i->sentry_lock);
+}
+
+bool is_checkpointed_data(struct f2fs_sb_info *sbi, block_t blkaddr)
+{
+	struct sit_info *sit_i = SIT_I(sbi);
+	unsigned int segno, offset;
+	struct seg_entry *se;
+	bool is_cp = false;
+
+	if (!is_valid_data_blkaddr(sbi, blkaddr))
+		return true;
+
+	down_read(&sit_i->sentry_lock);
+
+	segno = GET_SEGNO(sbi, blkaddr);
+	se = get_seg_entry(sbi, segno);
+	offset = GET_BLKOFF_FROM_SEG0(sbi, blkaddr);
+
+	if (f2fs_test_bit(offset, se->ckpt_valid_map))
+		is_cp = true;
+
+	up_read(&sit_i->sentry_lock);
+
+	return is_cp;
+}
+
+/*
+ * This function should be resided under the curseg_mutex lock
+ */
+static void __add_sum_entry(struct f2fs_sb_info *sbi, int type,
+					struct f2fs_summary *sum)
+{
+	struct curseg_info *curseg = CURSEG_I(sbi, type);
+	void *addr = curseg->sum_blk;
+	addr += curseg->next_blkoff * sizeof(struct f2fs_summary);
+	memcpy(addr, sum, sizeof(struct f2fs_summary));
+}
+
+/*
+ * Calculate the number of current summary pages for writing
+ */
+int npages_for_summary_flush(struct f2fs_sb_info *sbi, bool for_ra)
+{
+	int valid_sum_count = 0;
+	int i, sum_in_page;
+
+	for (i = CURSEG_HOT_DATA; i <= CURSEG_COLD_DATA; i++) {
+		if (sbi->ckpt->alloc_type[i] == SSR)
+			valid_sum_count += sbi->blocks_per_seg;
+		else {
+			if (for_ra)
+				valid_sum_count += le16_to_cpu(
+					F2FS_CKPT(sbi)->cur_data_blkoff[i]);
+			else
+				valid_sum_count += curseg_blkoff(sbi, i);
+		}
+	}
+
+	sum_in_page = (PAGE_SIZE - 2 * SUM_JOURNAL_SIZE -
+			SUM_FOOTER_SIZE) / SUMMARY_SIZE;
+	if (valid_sum_count <= sum_in_page)
+		return 1;
+	else if ((valid_sum_count - sum_in_page) <=
+		(PAGE_SIZE - SUM_FOOTER_SIZE) / SUMMARY_SIZE)
+		return 2;
+	return 3;
+}
+
+/*
+ * Caller should put this summary page
+ */
+struct page *get_sum_page(struct f2fs_sb_info *sbi, unsigned int segno)
+{
+	return get_meta_page(sbi, GET_SUM_BLOCK(sbi, segno));
+}
+
+void update_meta_page(struct f2fs_sb_info *sbi, void *src, block_t blk_addr)
+{
+	struct page *page = grab_meta_page(sbi, blk_addr);
+
+	memcpy(page_address(page), src, PAGE_SIZE);
+	set_page_dirty(page);
+	f2fs_put_page(page, 1);
+}
+
+static void write_sum_page(struct f2fs_sb_info *sbi,
+			struct f2fs_summary_block *sum_blk, block_t blk_addr)
+{
+	update_meta_page(sbi, (void *)sum_blk, blk_addr);
+}
+
+static void write_current_sum_page(struct f2fs_sb_info *sbi,
+						int type, block_t blk_addr)
+{
+	struct curseg_info *curseg = CURSEG_I(sbi, type);
+	struct page *page = grab_meta_page(sbi, blk_addr);
+	struct f2fs_summary_block *src = curseg->sum_blk;
+	struct f2fs_summary_block *dst;
+
+	dst = (struct f2fs_summary_block *)page_address(page);
+
+	mutex_lock(&curseg->curseg_mutex);
+
+	down_read(&curseg->journal_rwsem);
+	memcpy(&dst->journal, curseg->journal, SUM_JOURNAL_SIZE);
+	up_read(&curseg->journal_rwsem);
+
+	memcpy(dst->entries, src->entries, SUM_ENTRY_SIZE);
+	memcpy(&dst->footer, &src->footer, SUM_FOOTER_SIZE);
+
+	mutex_unlock(&curseg->curseg_mutex);
+
+	set_page_dirty(page);
+	f2fs_put_page(page, 1);
+}
+
+static int is_next_segment_free(struct f2fs_sb_info *sbi, int type)
+{
+	struct curseg_info *curseg = CURSEG_I(sbi, type);
+	unsigned int segno = curseg->segno + 1;
+	struct free_segmap_info *free_i = FREE_I(sbi);
+
+	if (segno < MAIN_SEGS(sbi) && segno % sbi->segs_per_sec)
+		return !test_bit(segno, free_i->free_segmap);
+	return 0;
+}
+
+/*
+ * Find a new segment from the free segments bitmap to right order
+ * This function should be returned with success, otherwise BUG
+ */
+static void get_new_segment(struct f2fs_sb_info *sbi,
+			unsigned int *newseg, bool new_sec, int dir)
+{
+	struct free_segmap_info *free_i = FREE_I(sbi);
+	unsigned int segno, secno, zoneno;
+	unsigned int total_zones = MAIN_SECS(sbi) / sbi->secs_per_zone;
+	unsigned int hint = GET_SEC_FROM_SEG(sbi, *newseg);
+	unsigned int old_zoneno = GET_ZONE_FROM_SEG(sbi, *newseg);
+	unsigned int left_start = hint;
+	bool init = true;
+	int go_left = 0;
+	int i;
+
+	spin_lock(&free_i->segmap_lock);
+
+	if (!new_sec && ((*newseg + 1) % sbi->segs_per_sec)) {
+		segno = find_next_zero_bit(free_i->free_segmap,
+			GET_SEG_FROM_SEC(sbi, hint + 1), *newseg + 1);
+		if (segno < GET_SEG_FROM_SEC(sbi, hint + 1))
+			goto got_it;
+	}
+find_other_zone:
+	secno = find_next_zero_bit(free_i->free_secmap, MAIN_SECS(sbi), hint);
+	if (secno >= MAIN_SECS(sbi)) {
+		if (dir == ALLOC_RIGHT) {
+			secno = find_next_zero_bit(free_i->free_secmap,
+							MAIN_SECS(sbi), 0);
+			f2fs_bug_on(sbi, secno >= MAIN_SECS(sbi));
+		} else {
+			go_left = 1;
+			left_start = hint - 1;
+		}
+	}
+	if (go_left == 0)
+		goto skip_left;
+
+	while (test_bit(left_start, free_i->free_secmap)) {
+		if (left_start > 0) {
+			left_start--;
+			continue;
+		}
+		left_start = find_next_zero_bit(free_i->free_secmap,
+							MAIN_SECS(sbi), 0);
+		f2fs_bug_on(sbi, left_start >= MAIN_SECS(sbi));
+		break;
+	}
+	secno = left_start;
+skip_left:
+	segno = GET_SEG_FROM_SEC(sbi, secno);
+	zoneno = GET_ZONE_FROM_SEC(sbi, secno);
+
+	/* give up on finding another zone */
+	if (!init)
+		goto got_it;
+	if (sbi->secs_per_zone == 1)
+		goto got_it;
+	if (zoneno == old_zoneno)
+		goto got_it;
+	if (dir == ALLOC_LEFT) {
+		if (!go_left && zoneno + 1 >= total_zones)
+			goto got_it;
+		if (go_left && zoneno == 0)
+			goto got_it;
+	}
+	for (i = 0; i < NR_CURSEG_TYPE; i++)
+		if (CURSEG_I(sbi, i)->zone == zoneno)
+			break;
+
+	if (i < NR_CURSEG_TYPE) {
+		/* zone is in user, try another */
+		if (go_left)
+			hint = zoneno * sbi->secs_per_zone - 1;
+		else if (zoneno + 1 >= total_zones)
+			hint = 0;
+		else
+			hint = (zoneno + 1) * sbi->secs_per_zone;
+		init = false;
+		goto find_other_zone;
+	}
+got_it:
+	/* set it as dirty segment in free segmap */
+	f2fs_bug_on(sbi, test_bit(segno, free_i->free_segmap));
+	__set_inuse(sbi, segno);
+	*newseg = segno;
+	spin_unlock(&free_i->segmap_lock);
+}
+
+static void reset_curseg(struct f2fs_sb_info *sbi, int type, int modified)
+{
+	struct curseg_info *curseg = CURSEG_I(sbi, type);
+	struct summary_footer *sum_footer;
+
+	curseg->segno = curseg->next_segno;
+	curseg->zone = GET_ZONE_FROM_SEG(sbi, curseg->segno);
+	curseg->next_blkoff = 0;
+	curseg->next_segno = NULL_SEGNO;
+
+	sum_footer = &(curseg->sum_blk->footer);
+	memset(sum_footer, 0, sizeof(struct summary_footer));
+	if (IS_DATASEG(type))
+		SET_SUM_TYPE(sum_footer, SUM_TYPE_DATA);
+	if (IS_NODESEG(type))
+		SET_SUM_TYPE(sum_footer, SUM_TYPE_NODE);
+	__set_sit_entry_type(sbi, type, curseg->segno, modified);
+}
+
+static unsigned int __get_next_segno(struct f2fs_sb_info *sbi, int type)
+{
+	/* if segs_per_sec is large than 1, we need to keep original policy. */
+	if (sbi->segs_per_sec != 1)
+		return CURSEG_I(sbi, type)->segno;
+
+	if (test_opt(sbi, NOHEAP) &&
+		(type == CURSEG_HOT_DATA || IS_NODESEG(type)))
+		return 0;
+
+	if (SIT_I(sbi)->last_victim[ALLOC_NEXT])
+		return SIT_I(sbi)->last_victim[ALLOC_NEXT];
+
+	/* find segments from 0 to reuse freed segments */
+	if (F2FS_OPTION(sbi).alloc_mode == ALLOC_MODE_REUSE)
+		return 0;
+
+	return CURSEG_I(sbi, type)->segno;
+}
+
+/*
+ * Allocate a current working segment.
+ * This function always allocates a free segment in LFS manner.
+ */
+static void new_curseg(struct f2fs_sb_info *sbi, int type, bool new_sec)
+{
+	struct curseg_info *curseg = CURSEG_I(sbi, type);
+	unsigned int segno = curseg->segno;
+	int dir = ALLOC_LEFT;
+
+	write_sum_page(sbi, curseg->sum_blk,
+				GET_SUM_BLOCK(sbi, segno));
+	if (type == CURSEG_WARM_DATA || type == CURSEG_COLD_DATA)
+		dir = ALLOC_RIGHT;
+
+	if (test_opt(sbi, NOHEAP))
+		dir = ALLOC_RIGHT;
+
+	segno = __get_next_segno(sbi, type);
+	get_new_segment(sbi, &segno, new_sec, dir);
+	curseg->next_segno = segno;
+	reset_curseg(sbi, type, 1);
+	curseg->alloc_type = LFS;
+}
+
+static void __next_free_blkoff(struct f2fs_sb_info *sbi,
+			struct curseg_info *seg, block_t start)
+{
+	struct seg_entry *se = get_seg_entry(sbi, seg->segno);
+	int entries = SIT_VBLOCK_MAP_SIZE / sizeof(unsigned long);
+	unsigned long *target_map = SIT_I(sbi)->tmp_map;
+	unsigned long *ckpt_map = (unsigned long *)se->ckpt_valid_map;
+	unsigned long *cur_map = (unsigned long *)se->cur_valid_map;
+	int i, pos;
+
+	for (i = 0; i < entries; i++)
+		target_map[i] = ckpt_map[i] | cur_map[i];
+
+	pos = __find_rev_next_zero_bit(target_map, sbi->blocks_per_seg, start);
+
+	seg->next_blkoff = pos;
+}
+
+/*
+ * If a segment is written by LFS manner, next block offset is just obtained
+ * by increasing the current block offset. However, if a segment is written by
+ * SSR manner, next block offset obtained by calling __next_free_blkoff
+ */
+static void __refresh_next_blkoff(struct f2fs_sb_info *sbi,
+				struct curseg_info *seg)
+{
+	if (seg->alloc_type == SSR)
+		__next_free_blkoff(sbi, seg, seg->next_blkoff + 1);
+	else
+		seg->next_blkoff++;
+}
+
+/*
+ * This function always allocates a used segment(from dirty seglist) by SSR
+ * manner, so it should recover the existing segment information of valid blocks
+ */
+static void change_curseg(struct f2fs_sb_info *sbi, int type)
+{
+	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
+	struct curseg_info *curseg = CURSEG_I(sbi, type);
+	unsigned int new_segno = curseg->next_segno;
+	struct f2fs_summary_block *sum_node;
+	struct page *sum_page;
+
+	write_sum_page(sbi, curseg->sum_blk,
+				GET_SUM_BLOCK(sbi, curseg->segno));
+	__set_test_and_inuse(sbi, new_segno);
+
+	mutex_lock(&dirty_i->seglist_lock);
+	__remove_dirty_segment(sbi, new_segno, PRE);
+	__remove_dirty_segment(sbi, new_segno, DIRTY);
+	mutex_unlock(&dirty_i->seglist_lock);
+
+	reset_curseg(sbi, type, 1);
+	curseg->alloc_type = SSR;
+	__next_free_blkoff(sbi, curseg, 0);
+
+	sum_page = get_sum_page(sbi, new_segno);
+	sum_node = (struct f2fs_summary_block *)page_address(sum_page);
+	memcpy(curseg->sum_blk, sum_node, SUM_ENTRY_SIZE);
+	f2fs_put_page(sum_page, 1);
+}
+
+static int get_ssr_segment(struct f2fs_sb_info *sbi, int type)
+{
+	struct curseg_info *curseg = CURSEG_I(sbi, type);
+	const struct victim_selection *v_ops = DIRTY_I(sbi)->v_ops;
+	unsigned segno = NULL_SEGNO;
+	int i, cnt;
+	bool reversed = false;
+
+	/* need_SSR() already forces to do this */
+	if (v_ops->get_victim(sbi, &segno, BG_GC, type, SSR)) {
+		curseg->next_segno = segno;
+		return 1;
+	}
+
+	/* For node segments, let's do SSR more intensively */
+	if (IS_NODESEG(type)) {
+		if (type >= CURSEG_WARM_NODE) {
+			reversed = true;
+			i = CURSEG_COLD_NODE;
+		} else {
+			i = CURSEG_HOT_NODE;
+		}
+		cnt = NR_CURSEG_NODE_TYPE;
+	} else {
+		if (type >= CURSEG_WARM_DATA) {
+			reversed = true;
+			i = CURSEG_COLD_DATA;
+		} else {
+			i = CURSEG_HOT_DATA;
+		}
+		cnt = NR_CURSEG_DATA_TYPE;
+	}
+
+	for (; cnt-- > 0; reversed ? i-- : i++) {
+		if (i == type)
+			continue;
+		if (v_ops->get_victim(sbi, &segno, BG_GC, i, SSR)) {
+			curseg->next_segno = segno;
+			return 1;
+		}
+	}
+	return 0;
+}
+
+/*
+ * flush out current segment and replace it with new segment
+ * This function should be returned with success, otherwise BUG
+ */
+static void allocate_segment_by_default(struct f2fs_sb_info *sbi,
+						int type, bool force)
+{
+	struct curseg_info *curseg = CURSEG_I(sbi, type);
+
+	if (force)
+		new_curseg(sbi, type, true);
+	else if (!is_set_ckpt_flags(sbi, CP_CRC_RECOVERY_FLAG) &&
+					type == CURSEG_WARM_NODE)
+		new_curseg(sbi, type, false);
+	else if (curseg->alloc_type == LFS && is_next_segment_free(sbi, type))
+		new_curseg(sbi, type, false);
+	else if (need_SSR(sbi) && get_ssr_segment(sbi, type))
+		change_curseg(sbi, type);
+	else
+		new_curseg(sbi, type, false);
+
+	stat_inc_seg_type(sbi, curseg);
+}
+
+void allocate_new_segments(struct f2fs_sb_info *sbi)
+{
+	struct curseg_info *curseg;
+	unsigned int old_segno;
+	int i;
+
+	down_write(&SIT_I(sbi)->sentry_lock);
+
+	for (i = CURSEG_HOT_DATA; i <= CURSEG_COLD_DATA; i++) {
+		curseg = CURSEG_I(sbi, i);
+		old_segno = curseg->segno;
+		SIT_I(sbi)->s_ops->allocate_segment(sbi, i, true);
+		locate_dirty_segment(sbi, old_segno);
+	}
+
+	up_write(&SIT_I(sbi)->sentry_lock);
+}
+
+static const struct segment_allocation default_salloc_ops = {
+	.allocate_segment = allocate_segment_by_default,
+};
+
+bool exist_trim_candidates(struct f2fs_sb_info *sbi, struct cp_control *cpc)
+{
+	__u64 trim_start = cpc->trim_start;
+	bool has_candidate = false;
+
+	down_write(&SIT_I(sbi)->sentry_lock);
+	for (; cpc->trim_start <= cpc->trim_end; cpc->trim_start++) {
+		if (add_discard_addrs(sbi, cpc, true)) {
+			has_candidate = true;
+			break;
+		}
+	}
+	up_write(&SIT_I(sbi)->sentry_lock);
+
+	cpc->trim_start = trim_start;
+	return has_candidate;
+}
+
+static void __issue_discard_cmd_range(struct f2fs_sb_info *sbi,
+					struct discard_policy *dpolicy,
+					unsigned int start, unsigned int end)
+{
+	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
+	struct discard_cmd *prev_dc = NULL, *next_dc = NULL;
+	struct rb_node **insert_p = NULL, *insert_parent = NULL;
+	struct discard_cmd *dc;
+	struct blk_plug plug;
+	int issued;
+
+next:
+	issued = 0;
+
+	mutex_lock(&dcc->cmd_lock);
+	f2fs_bug_on(sbi, !__check_rb_tree_consistence(sbi, &dcc->root));
+
+	dc = (struct discard_cmd *)__lookup_rb_tree_ret(&dcc->root,
+					NULL, start,
+					(struct rb_entry **)&prev_dc,
+					(struct rb_entry **)&next_dc,
+					&insert_p, &insert_parent, true);
+	if (!dc)
+		dc = next_dc;
+
+	blk_start_plug(&plug);
+
+	while (dc && dc->lstart <= end) {
+		struct rb_node *node;
+
+		if (dc->len < dpolicy->granularity)
+			goto skip;
+
+		if (dc->state != D_PREP) {
+			list_move_tail(&dc->list, &dcc->fstrim_list);
+			goto skip;
+		}
+
+		__submit_discard_cmd(sbi, dpolicy, dc);
+
+		if (++issued >= dpolicy->max_requests) {
+			start = dc->lstart + dc->len;
+
+			blk_finish_plug(&plug);
+			mutex_unlock(&dcc->cmd_lock);
+			__wait_all_discard_cmd(sbi, NULL);
+			congestion_wait(BLK_RW_ASYNC, HZ/50);
+			goto next;
+		}
+skip:
+		node = rb_next(&dc->rb_node);
+		dc = rb_entry_safe(node, struct discard_cmd, rb_node);
+
+		if (fatal_signal_pending(current))
+			break;
+	}
+
+	blk_finish_plug(&plug);
+	mutex_unlock(&dcc->cmd_lock);
+}
+
+int f2fs_trim_fs(struct f2fs_sb_info *sbi, struct fstrim_range *range)
+{
+	__u64 start = F2FS_BYTES_TO_BLK(range->start);
+	__u64 end = start + F2FS_BYTES_TO_BLK(range->len) - 1;
+	unsigned int start_segno, end_segno;
+	block_t start_block, end_block;
+	struct cp_control cpc;
+	struct discard_policy dpolicy;
+	unsigned long long trimmed = 0;
+	int err = 0;
+
+	if (start >= MAX_BLKADDR(sbi) || range->len < sbi->blocksize)
+		return -EINVAL;
+
+	if (end <= MAIN_BLKADDR(sbi))
+		goto out;
+
+	if (is_sbi_flag_set(sbi, SBI_NEED_FSCK)) {
+		f2fs_msg(sbi->sb, KERN_WARNING,
+			"Found FS corruption, run fsck to fix.");
+		err = -EFSCORRUPTED;
+		goto out;
+	}
+
+	/* start/end segment number in main_area */
+	start_segno = (start <= MAIN_BLKADDR(sbi)) ? 0 : GET_SEGNO(sbi, start);
+	end_segno = (end >= MAX_BLKADDR(sbi)) ? MAIN_SEGS(sbi) - 1 :
+						GET_SEGNO(sbi, end);
+
+	cpc.reason = CP_DISCARD;
+	cpc.trim_minlen = max_t(__u64, 1, F2FS_BYTES_TO_BLK(range->minlen));
+	cpc.trim_start = start_segno;
+	cpc.trim_end = end_segno;
+
+	if (sbi->discard_blks == 0)
+		goto out;
+
+	mutex_lock(&sbi->gc_mutex);
+	err = write_checkpoint(sbi, &cpc);
+	mutex_unlock(&sbi->gc_mutex);
+	if (err)
+		goto out;
+
+	start_block = START_BLOCK(sbi, start_segno);
+	end_block = START_BLOCK(sbi, end_segno + 1);
+
+	__init_discard_policy(sbi, &dpolicy, DPOLICY_FSTRIM, cpc.trim_minlen);
+	__issue_discard_cmd_range(sbi, &dpolicy, start_block, end_block);
+
+	/*
+	 * We filed discard candidates, but actually we don't need to wait for
+	 * all of them, since they'll be issued in idle time along with runtime
+	 * discard option. User configuration looks like using runtime discard
+	 * or periodic fstrim instead of it.
+	 */
+	if (!test_opt(sbi, DISCARD)) {
+		trimmed = __wait_discard_cmd_range(sbi, &dpolicy,
+					start_block, end_block);
+		range->len = F2FS_BLK_TO_BYTES(trimmed);
+	}
+out:
+	return err;
+}
+
+static bool __has_curseg_space(struct f2fs_sb_info *sbi, int type)
+{
+	struct curseg_info *curseg = CURSEG_I(sbi, type);
+	if (curseg->next_blkoff < sbi->blocks_per_seg)
+		return true;
+	return false;
+}
+
+int rw_hint_to_seg_type(enum rw_hint hint)
+{
+	switch (hint) {
+	case WRITE_LIFE_SHORT:
+		return CURSEG_HOT_DATA;
+	case WRITE_LIFE_EXTREME:
+		return CURSEG_COLD_DATA;
+	default:
+		return CURSEG_WARM_DATA;
+	}
+}
+
+/* This returns write hints for each segment type. This hints will be
+ * passed down to block layer. There are mapping tables which depend on
+ * the mount option 'whint_mode'.
+ *
+ * 1) whint_mode=off. F2FS only passes down WRITE_LIFE_NOT_SET.
+ *
+ * 2) whint_mode=user-based. F2FS tries to pass down hints given by users.
+ *
+ * User                  F2FS                     Block
+ * ----                  ----                     -----
+ *                       META                     WRITE_LIFE_NOT_SET
+ *                       HOT_NODE                 "
+ *                       WARM_NODE                "
+ *                       COLD_NODE                "
+ * ioctl(COLD)           COLD_DATA                WRITE_LIFE_EXTREME
+ * extension list        "                        "
+ *
+ * -- buffered io
+ * WRITE_LIFE_EXTREME    COLD_DATA                WRITE_LIFE_EXTREME
+ * WRITE_LIFE_SHORT      HOT_DATA                 WRITE_LIFE_SHORT
+ * WRITE_LIFE_NOT_SET    WARM_DATA                WRITE_LIFE_NOT_SET
+ * WRITE_LIFE_NONE       "                        "
+ * WRITE_LIFE_MEDIUM     "                        "
+ * WRITE_LIFE_LONG       "                        "
+ *
+ * -- direct io
+ * WRITE_LIFE_EXTREME    COLD_DATA                WRITE_LIFE_EXTREME
+ * WRITE_LIFE_SHORT      HOT_DATA                 WRITE_LIFE_SHORT
+ * WRITE_LIFE_NOT_SET    WARM_DATA                WRITE_LIFE_NOT_SET
+ * WRITE_LIFE_NONE       "                        WRITE_LIFE_NONE
+ * WRITE_LIFE_MEDIUM     "                        WRITE_LIFE_MEDIUM
+ * WRITE_LIFE_LONG       "                        WRITE_LIFE_LONG
+ *
+ * 3) whint_mode=fs-based. F2FS passes down hints with its policy.
+ *
+ * User                  F2FS                     Block
+ * ----                  ----                     -----
+ *                       META                     WRITE_LIFE_MEDIUM;
+ *                       HOT_NODE                 WRITE_LIFE_NOT_SET
+ *                       WARM_NODE                "
+ *                       COLD_NODE                WRITE_LIFE_NONE
+ * ioctl(COLD)           COLD_DATA                WRITE_LIFE_EXTREME
+ * extension list        "                        "
+ *
+ * -- buffered io
+ * WRITE_LIFE_EXTREME    COLD_DATA                WRITE_LIFE_EXTREME
+ * WRITE_LIFE_SHORT      HOT_DATA                 WRITE_LIFE_SHORT
+ * WRITE_LIFE_NOT_SET    WARM_DATA                WRITE_LIFE_LONG
+ * WRITE_LIFE_NONE       "                        "
+ * WRITE_LIFE_MEDIUM     "                        "
+ * WRITE_LIFE_LONG       "                        "
+ *
+ * -- direct io
+ * WRITE_LIFE_EXTREME    COLD_DATA                WRITE_LIFE_EXTREME
+ * WRITE_LIFE_SHORT      HOT_DATA                 WRITE_LIFE_SHORT
+ * WRITE_LIFE_NOT_SET    WARM_DATA                WRITE_LIFE_NOT_SET
+ * WRITE_LIFE_NONE       "                        WRITE_LIFE_NONE
+ * WRITE_LIFE_MEDIUM     "                        WRITE_LIFE_MEDIUM
+ * WRITE_LIFE_LONG       "                        WRITE_LIFE_LONG
+ */
+
+enum rw_hint io_type_to_rw_hint(struct f2fs_sb_info *sbi,
+				enum page_type type, enum temp_type temp)
+{
+	if (F2FS_OPTION(sbi).whint_mode == WHINT_MODE_USER) {
+		if (type == DATA) {
+			if (temp == WARM)
+				return WRITE_LIFE_NOT_SET;
+			else if (temp == HOT)
+				return WRITE_LIFE_SHORT;
+			else if (temp == COLD)
+				return WRITE_LIFE_EXTREME;
+		} else {
+			return WRITE_LIFE_NOT_SET;
+		}
+	} else if (F2FS_OPTION(sbi).whint_mode == WHINT_MODE_FS) {
+		if (type == DATA) {
+			if (temp == WARM)
+				return WRITE_LIFE_LONG;
+			else if (temp == HOT)
+				return WRITE_LIFE_SHORT;
+			else if (temp == COLD)
+				return WRITE_LIFE_EXTREME;
+		} else if (type == NODE) {
+			if (temp == WARM || temp == HOT)
+				return WRITE_LIFE_NOT_SET;
+			else if (temp == COLD)
+				return WRITE_LIFE_NONE;
+		} else if (type == META) {
+			return WRITE_LIFE_MEDIUM;
+		}
+	}
+	return WRITE_LIFE_NOT_SET;
+}
+
+static int __get_segment_type_2(struct f2fs_io_info *fio)
+{
+	if (fio->type == DATA)
+		return CURSEG_HOT_DATA;
+	else
+		return CURSEG_HOT_NODE;
+}
+
+static int __get_segment_type_4(struct f2fs_io_info *fio)
+{
+	if (fio->type == DATA) {
+		struct inode *inode = fio->page->mapping->host;
+
+		if (S_ISDIR(inode->i_mode))
+			return CURSEG_HOT_DATA;
+		else
+			return CURSEG_COLD_DATA;
+	} else {
+		if (IS_DNODE(fio->page) && is_cold_node(fio->page))
+			return CURSEG_WARM_NODE;
+		else
+			return CURSEG_COLD_NODE;
+	}
+}
+
+static int __get_segment_type_6(struct f2fs_io_info *fio)
+{
+	if (fio->type == DATA) {
+		struct inode *inode = fio->page->mapping->host;
+
+		if (is_cold_data(fio->page) || file_is_cold(inode))
+			return CURSEG_COLD_DATA;
+		if (file_is_hot(inode) ||
+				is_inode_flag_set(inode, FI_HOT_DATA))
+			return CURSEG_HOT_DATA;
+		return rw_hint_to_seg_type(inode->i_write_hint);
+	} else {
+		if (IS_DNODE(fio->page))
+			return is_cold_node(fio->page) ? CURSEG_WARM_NODE :
+						CURSEG_HOT_NODE;
+		return CURSEG_COLD_NODE;
+	}
+}
+
+static int __get_segment_type(struct f2fs_io_info *fio)
+{
+	int type = 0;
+
+	switch (F2FS_OPTION(fio->sbi).active_logs) {
+	case 2:
+		type = __get_segment_type_2(fio);
+		break;
+	case 4:
+		type = __get_segment_type_4(fio);
+		break;
+	case 6:
+		type = __get_segment_type_6(fio);
+		break;
+	default:
+		f2fs_bug_on(fio->sbi, true);
+	}
+
+	if (IS_HOT(type))
+		fio->temp = HOT;
+	else if (IS_WARM(type))
+		fio->temp = WARM;
+	else
+		fio->temp = COLD;
+	return type;
+}
+
+void allocate_data_block(struct f2fs_sb_info *sbi, struct page *page,
+		block_t old_blkaddr, block_t *new_blkaddr,
+		struct f2fs_summary *sum, int type,
+		struct f2fs_io_info *fio, bool add_list)
+{
+	struct sit_info *sit_i = SIT_I(sbi);
+	struct curseg_info *curseg = CURSEG_I(sbi, type);
+
+	down_read(&SM_I(sbi)->curseg_lock);
+
+	mutex_lock(&curseg->curseg_mutex);
+	down_write(&sit_i->sentry_lock);
+
+	*new_blkaddr = NEXT_FREE_BLKADDR(sbi, curseg);
+
+	f2fs_wait_discard_bio(sbi, *new_blkaddr);
+
+	/*
+	 * __add_sum_entry should be resided under the curseg_mutex
+	 * because, this function updates a summary entry in the
+	 * current summary block.
+	 */
+	__add_sum_entry(sbi, type, sum);
+
+	__refresh_next_blkoff(sbi, curseg);
+
+	stat_inc_block_count(sbi, curseg);
+
+	/*
+	 * SIT information should be updated before segment allocation,
+	 * since SSR needs latest valid block information.
+	 */
+	update_sit_entry(sbi, *new_blkaddr, 1);
+	if (GET_SEGNO(sbi, old_blkaddr) != NULL_SEGNO)
+		update_sit_entry(sbi, old_blkaddr, -1);
+
+	if (!__has_curseg_space(sbi, type))
+		sit_i->s_ops->allocate_segment(sbi, type, false);
+
+	/*
+	 * segment dirty status should be updated after segment allocation,
+	 * so we just need to update status only one time after previous
+	 * segment being closed.
+	 */
+	locate_dirty_segment(sbi, GET_SEGNO(sbi, old_blkaddr));
+	locate_dirty_segment(sbi, GET_SEGNO(sbi, *new_blkaddr));
+
+	up_write(&sit_i->sentry_lock);
+
+	if (page && IS_NODESEG(type)) {
+		fill_node_footer_blkaddr(page, NEXT_FREE_BLKADDR(sbi, curseg));
+
+		f2fs_inode_chksum_set(sbi, page);
+	}
+
+	if (add_list) {
+		struct f2fs_bio_info *io;
+
+		INIT_LIST_HEAD(&fio->list);
+		fio->in_list = true;
+		io = sbi->write_io[fio->type] + fio->temp;
+		spin_lock(&io->io_lock);
+		list_add_tail(&fio->list, &io->io_list);
+		spin_unlock(&io->io_lock);
+	}
+
+	mutex_unlock(&curseg->curseg_mutex);
+
+	up_read(&SM_I(sbi)->curseg_lock);
+}
+
+static void update_device_state(struct f2fs_io_info *fio)
+{
+	struct f2fs_sb_info *sbi = fio->sbi;
+	unsigned int devidx;
+
+	if (!sbi->s_ndevs)
+		return;
+
+	devidx = f2fs_target_device_index(sbi, fio->new_blkaddr);
+
+	/* update device state for fsync */
+	set_dirty_device(sbi, fio->ino, devidx, FLUSH_INO);
+
+	/* update device state for checkpoint */
+	if (!f2fs_test_bit(devidx, (char *)&sbi->dirty_device)) {
+		spin_lock(&sbi->dev_lock);
+		f2fs_set_bit(devidx, (char *)&sbi->dirty_device);
+		spin_unlock(&sbi->dev_lock);
+	}
+}
+
+static void do_write_page(struct f2fs_summary *sum, struct f2fs_io_info *fio)
+{
+	int type = __get_segment_type(fio);
+	int err;
+
+reallocate:
+	allocate_data_block(fio->sbi, fio->page, fio->old_blkaddr,
+			&fio->new_blkaddr, sum, type, fio, true);
+
+	/* writeout dirty page into bdev */
+	err = f2fs_submit_page_write(fio);
+	if (err == -EAGAIN) {
+		fio->old_blkaddr = fio->new_blkaddr;
+		goto reallocate;
+	} else if (!err) {
+		update_device_state(fio);
+	}
+}
+
+void write_meta_page(struct f2fs_sb_info *sbi, struct page *page,
+					enum iostat_type io_type)
+{
+	struct f2fs_io_info fio = {
+		.sbi = sbi,
+		.type = META,
+		.temp = HOT,
+		.op = REQ_OP_WRITE,
+		.op_flags = REQ_SYNC | REQ_META | REQ_PRIO,
+		.old_blkaddr = page->index,
+		.new_blkaddr = page->index,
+		.page = page,
+		.encrypted_page = NULL,
+		.in_list = false,
+	};
+
+	if (unlikely(page->index >= MAIN_BLKADDR(sbi)))
+		fio.op_flags &= ~REQ_META;
+
+	set_page_writeback(page);
+	ClearPageError(page);
+	f2fs_submit_page_write(&fio);
+
+	f2fs_update_iostat(sbi, io_type, F2FS_BLKSIZE);
+}
+
+void write_node_page(unsigned int nid, struct f2fs_io_info *fio)
+{
+	struct f2fs_summary sum;
+
+	set_summary(&sum, nid, 0, 0);
+	do_write_page(&sum, fio);
+
+	f2fs_update_iostat(fio->sbi, fio->io_type, F2FS_BLKSIZE);
+}
+
+void write_data_page(struct dnode_of_data *dn, struct f2fs_io_info *fio)
+{
+	struct f2fs_sb_info *sbi = fio->sbi;
+	struct f2fs_summary sum;
+	struct node_info ni;
+
+	f2fs_bug_on(sbi, dn->data_blkaddr == NULL_ADDR);
+	get_node_info(sbi, dn->nid, &ni);
+	set_summary(&sum, dn->nid, dn->ofs_in_node, ni.version);
+	do_write_page(&sum, fio);
+	f2fs_update_data_blkaddr(dn, fio->new_blkaddr);
+
+	f2fs_update_iostat(sbi, fio->io_type, F2FS_BLKSIZE);
+}
+
+int rewrite_data_page(struct f2fs_io_info *fio)
+{
+	int err;
+	struct f2fs_sb_info *sbi = fio->sbi;
+
+	fio->new_blkaddr = fio->old_blkaddr;
+	/* i/o temperature is needed for passing down write hints */
+	__get_segment_type(fio);
+
+	f2fs_bug_on(sbi, !IS_DATASEG(get_seg_entry(sbi,
+			GET_SEGNO(sbi, fio->new_blkaddr))->type));
+
+	stat_inc_inplace_blocks(fio->sbi);
+
+	err = f2fs_submit_page_bio(fio);
+	if (!err)
+		update_device_state(fio);
+
+	f2fs_update_iostat(fio->sbi, fio->io_type, F2FS_BLKSIZE);
+
+	return err;
+}
+
+static inline int __f2fs_get_curseg(struct f2fs_sb_info *sbi,
+						unsigned int segno)
+{
+	int i;
+
+	for (i = CURSEG_HOT_DATA; i < NO_CHECK_TYPE; i++) {
+		if (CURSEG_I(sbi, i)->segno == segno)
+			break;
+	}
+	return i;
+}
+
+void __f2fs_replace_block(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
+				block_t old_blkaddr, block_t new_blkaddr,
+				bool recover_curseg, bool recover_newaddr)
+{
+	struct sit_info *sit_i = SIT_I(sbi);
+	struct curseg_info *curseg;
+	unsigned int segno, old_cursegno;
+	struct seg_entry *se;
+	int type;
+	unsigned short old_blkoff;
+
+	segno = GET_SEGNO(sbi, new_blkaddr);
+	se = get_seg_entry(sbi, segno);
+	type = se->type;
+
+	down_write(&SM_I(sbi)->curseg_lock);
+
+	if (!recover_curseg) {
+		/* for recovery flow */
+		if (se->valid_blocks == 0 && !IS_CURSEG(sbi, segno)) {
+			if (old_blkaddr == NULL_ADDR)
+				type = CURSEG_COLD_DATA;
+			else
+				type = CURSEG_WARM_DATA;
+		}
+	} else {
+		if (IS_CURSEG(sbi, segno)) {
+			/* se->type is volatile as SSR allocation */
+			type = __f2fs_get_curseg(sbi, segno);
+			f2fs_bug_on(sbi, type == NO_CHECK_TYPE);
+		} else {
+			type = CURSEG_WARM_DATA;
+		}
+	}
+
+	f2fs_bug_on(sbi, !IS_DATASEG(type));
+	curseg = CURSEG_I(sbi, type);
+
+	mutex_lock(&curseg->curseg_mutex);
+	down_write(&sit_i->sentry_lock);
+
+	old_cursegno = curseg->segno;
+	old_blkoff = curseg->next_blkoff;
+
+	/* change the current segment */
+	if (segno != curseg->segno) {
+		curseg->next_segno = segno;
+		change_curseg(sbi, type);
+	}
+
+	curseg->next_blkoff = GET_BLKOFF_FROM_SEG0(sbi, new_blkaddr);
+	__add_sum_entry(sbi, type, sum);
+
+	if (!recover_curseg || recover_newaddr)
+		update_sit_entry(sbi, new_blkaddr, 1);
+	if (GET_SEGNO(sbi, old_blkaddr) != NULL_SEGNO)
+		update_sit_entry(sbi, old_blkaddr, -1);
+
+	locate_dirty_segment(sbi, GET_SEGNO(sbi, old_blkaddr));
+	locate_dirty_segment(sbi, GET_SEGNO(sbi, new_blkaddr));
+
+	locate_dirty_segment(sbi, old_cursegno);
+
+	if (recover_curseg) {
+		if (old_cursegno != curseg->segno) {
+			curseg->next_segno = old_cursegno;
+			change_curseg(sbi, type);
+		}
+		curseg->next_blkoff = old_blkoff;
+	}
+
+	up_write(&sit_i->sentry_lock);
+	mutex_unlock(&curseg->curseg_mutex);
+	up_write(&SM_I(sbi)->curseg_lock);
+}
+
+void f2fs_replace_block(struct f2fs_sb_info *sbi, struct dnode_of_data *dn,
+				block_t old_addr, block_t new_addr,
+				unsigned char version, bool recover_curseg,
+				bool recover_newaddr)
+{
+	struct f2fs_summary sum;
+
+	set_summary(&sum, dn->nid, dn->ofs_in_node, version);
+
+	__f2fs_replace_block(sbi, &sum, old_addr, new_addr,
+					recover_curseg, recover_newaddr);
+
+	f2fs_update_data_blkaddr(dn, new_addr);
+}
+
+void f2fs_wait_on_page_writeback(struct page *page,
+				enum page_type type, bool ordered)
+{
+	if (PageWriteback(page)) {
+		struct f2fs_sb_info *sbi = F2FS_P_SB(page);
+
+		f2fs_submit_merged_write_cond(sbi, page->mapping->host,
+						0, page->index, type);
+		if (ordered)
+			wait_on_page_writeback(page);
+		else
+			wait_for_stable_page(page);
+	}
+}
+
+void f2fs_wait_on_block_writeback(struct f2fs_sb_info *sbi, block_t blkaddr)
+{
+	struct page *cpage;
+
+	if (!is_valid_data_blkaddr(sbi, blkaddr))
+		return;
+
+	cpage = find_lock_page(META_MAPPING(sbi), blkaddr);
+	if (cpage) {
+		f2fs_wait_on_page_writeback(cpage, DATA, true);
+		f2fs_put_page(cpage, 1);
+	}
+}
+
+static void read_compacted_summaries(struct f2fs_sb_info *sbi)
+{
+	struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
+	struct curseg_info *seg_i;
+	unsigned char *kaddr;
+	struct page *page;
+	block_t start;
+	int i, j, offset;
+
+	start = start_sum_block(sbi);
+
+	page = get_meta_page(sbi, start++);
+	kaddr = (unsigned char *)page_address(page);
+
+	/* Step 1: restore nat cache */
+	seg_i = CURSEG_I(sbi, CURSEG_HOT_DATA);
+	memcpy(seg_i->journal, kaddr, SUM_JOURNAL_SIZE);
+
+	/* Step 2: restore sit cache */
+	seg_i = CURSEG_I(sbi, CURSEG_COLD_DATA);
+	memcpy(seg_i->journal, kaddr + SUM_JOURNAL_SIZE, SUM_JOURNAL_SIZE);
+	offset = 2 * SUM_JOURNAL_SIZE;
+
+	/* Step 3: restore summary entries */
+	for (i = CURSEG_HOT_DATA; i <= CURSEG_COLD_DATA; i++) {
+		unsigned short blk_off;
+		unsigned int segno;
+
+		seg_i = CURSEG_I(sbi, i);
+		segno = le32_to_cpu(ckpt->cur_data_segno[i]);
+		blk_off = le16_to_cpu(ckpt->cur_data_blkoff[i]);
+		seg_i->next_segno = segno;
+		reset_curseg(sbi, i, 0);
+		seg_i->alloc_type = ckpt->alloc_type[i];
+		seg_i->next_blkoff = blk_off;
+
+		if (seg_i->alloc_type == SSR)
+			blk_off = sbi->blocks_per_seg;
+
+		for (j = 0; j < blk_off; j++) {
+			struct f2fs_summary *s;
+			s = (struct f2fs_summary *)(kaddr + offset);
+			seg_i->sum_blk->entries[j] = *s;
+			offset += SUMMARY_SIZE;
+			if (offset + SUMMARY_SIZE <= PAGE_SIZE -
+						SUM_FOOTER_SIZE)
+				continue;
+
+			f2fs_put_page(page, 1);
+			page = NULL;
+
+			page = get_meta_page(sbi, start++);
+			kaddr = (unsigned char *)page_address(page);
+			offset = 0;
+		}
+	}
+	f2fs_put_page(page, 1);
+}
+
+static int read_normal_summaries(struct f2fs_sb_info *sbi, int type)
+{
+	struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
+	struct f2fs_summary_block *sum;
+	struct curseg_info *curseg;
+	struct page *new;
+	unsigned short blk_off;
+	unsigned int segno = 0;
+	block_t blk_addr = 0;
+
+	/* get segment number and block addr */
+	if (IS_DATASEG(type)) {
+		segno = le32_to_cpu(ckpt->cur_data_segno[type]);
+		blk_off = le16_to_cpu(ckpt->cur_data_blkoff[type -
+							CURSEG_HOT_DATA]);
+		if (__exist_node_summaries(sbi))
+			blk_addr = sum_blk_addr(sbi, NR_CURSEG_TYPE, type);
+		else
+			blk_addr = sum_blk_addr(sbi, NR_CURSEG_DATA_TYPE, type);
+	} else {
+		segno = le32_to_cpu(ckpt->cur_node_segno[type -
+							CURSEG_HOT_NODE]);
+		blk_off = le16_to_cpu(ckpt->cur_node_blkoff[type -
+							CURSEG_HOT_NODE]);
+		if (__exist_node_summaries(sbi))
+			blk_addr = sum_blk_addr(sbi, NR_CURSEG_NODE_TYPE,
+							type - CURSEG_HOT_NODE);
+		else
+			blk_addr = GET_SUM_BLOCK(sbi, segno);
+	}
+
+	new = get_meta_page(sbi, blk_addr);
+	sum = (struct f2fs_summary_block *)page_address(new);
+
+	if (IS_NODESEG(type)) {
+		if (__exist_node_summaries(sbi)) {
+			struct f2fs_summary *ns = &sum->entries[0];
+			int i;
+			for (i = 0; i < sbi->blocks_per_seg; i++, ns++) {
+				ns->version = 0;
+				ns->ofs_in_node = 0;
+			}
+		} else {
+			restore_node_summary(sbi, segno, sum);
+		}
+	}
+
+	/* set uncompleted segment to curseg */
+	curseg = CURSEG_I(sbi, type);
+	mutex_lock(&curseg->curseg_mutex);
+
+	/* update journal info */
+	down_write(&curseg->journal_rwsem);
+	memcpy(curseg->journal, &sum->journal, SUM_JOURNAL_SIZE);
+	up_write(&curseg->journal_rwsem);
+
+	memcpy(curseg->sum_blk->entries, sum->entries, SUM_ENTRY_SIZE);
+	memcpy(&curseg->sum_blk->footer, &sum->footer, SUM_FOOTER_SIZE);
+	curseg->next_segno = segno;
+	reset_curseg(sbi, type, 0);
+	curseg->alloc_type = ckpt->alloc_type[type];
+	curseg->next_blkoff = blk_off;
+	mutex_unlock(&curseg->curseg_mutex);
+	f2fs_put_page(new, 1);
+	return 0;
+}
+
+static int restore_curseg_summaries(struct f2fs_sb_info *sbi)
+{
+	struct f2fs_journal *sit_j = CURSEG_I(sbi, CURSEG_COLD_DATA)->journal;
+	struct f2fs_journal *nat_j = CURSEG_I(sbi, CURSEG_HOT_DATA)->journal;
+	int type = CURSEG_HOT_DATA;
+	int err;
+
+	if (is_set_ckpt_flags(sbi, CP_COMPACT_SUM_FLAG)) {
+		int npages = npages_for_summary_flush(sbi, true);
+
+		if (npages >= 2)
+			ra_meta_pages(sbi, start_sum_block(sbi), npages,
+							META_CP, true);
+
+		/* restore for compacted data summary */
+		read_compacted_summaries(sbi);
+		type = CURSEG_HOT_NODE;
+	}
+
+	if (__exist_node_summaries(sbi))
+		ra_meta_pages(sbi, sum_blk_addr(sbi, NR_CURSEG_TYPE, type),
+					NR_CURSEG_TYPE - type, META_CP, true);
+
+	for (; type <= CURSEG_COLD_NODE; type++) {
+		err = read_normal_summaries(sbi, type);
+		if (err)
+			return err;
+	}
+
+	/* sanity check for summary blocks */
+	if (nats_in_cursum(nat_j) > NAT_JOURNAL_ENTRIES ||
+			sits_in_cursum(sit_j) > SIT_JOURNAL_ENTRIES)
+		return -EINVAL;
+
+	return 0;
+}
+
+static void write_compacted_summaries(struct f2fs_sb_info *sbi, block_t blkaddr)
+{
+	struct page *page;
+	unsigned char *kaddr;
+	struct f2fs_summary *summary;
+	struct curseg_info *seg_i;
+	int written_size = 0;
+	int i, j;
+
+	page = grab_meta_page(sbi, blkaddr++);
+	kaddr = (unsigned char *)page_address(page);
+
+	/* Step 1: write nat cache */
+	seg_i = CURSEG_I(sbi, CURSEG_HOT_DATA);
+	memcpy(kaddr, seg_i->journal, SUM_JOURNAL_SIZE);
+	written_size += SUM_JOURNAL_SIZE;
+
+	/* Step 2: write sit cache */
+	seg_i = CURSEG_I(sbi, CURSEG_COLD_DATA);
+	memcpy(kaddr + written_size, seg_i->journal, SUM_JOURNAL_SIZE);
+	written_size += SUM_JOURNAL_SIZE;
+
+	/* Step 3: write summary entries */
+	for (i = CURSEG_HOT_DATA; i <= CURSEG_COLD_DATA; i++) {
+		unsigned short blkoff;
+		seg_i = CURSEG_I(sbi, i);
+		if (sbi->ckpt->alloc_type[i] == SSR)
+			blkoff = sbi->blocks_per_seg;
+		else
+			blkoff = curseg_blkoff(sbi, i);
+
+		for (j = 0; j < blkoff; j++) {
+			if (!page) {
+				page = grab_meta_page(sbi, blkaddr++);
+				kaddr = (unsigned char *)page_address(page);
+				written_size = 0;
+			}
+			summary = (struct f2fs_summary *)(kaddr + written_size);
+			*summary = seg_i->sum_blk->entries[j];
+			written_size += SUMMARY_SIZE;
+
+			if (written_size + SUMMARY_SIZE <= PAGE_SIZE -
+							SUM_FOOTER_SIZE)
+				continue;
+
+			set_page_dirty(page);
+			f2fs_put_page(page, 1);
+			page = NULL;
+		}
+	}
+	if (page) {
+		set_page_dirty(page);
+		f2fs_put_page(page, 1);
+	}
+}
+
+static void write_normal_summaries(struct f2fs_sb_info *sbi,
+					block_t blkaddr, int type)
+{
+	int i, end;
+	if (IS_DATASEG(type))
+		end = type + NR_CURSEG_DATA_TYPE;
+	else
+		end = type + NR_CURSEG_NODE_TYPE;
+
+	for (i = type; i < end; i++)
+		write_current_sum_page(sbi, i, blkaddr + (i - type));
+}
+
+void write_data_summaries(struct f2fs_sb_info *sbi, block_t start_blk)
+{
+	if (is_set_ckpt_flags(sbi, CP_COMPACT_SUM_FLAG))
+		write_compacted_summaries(sbi, start_blk);
+	else
+		write_normal_summaries(sbi, start_blk, CURSEG_HOT_DATA);
+}
+
+void write_node_summaries(struct f2fs_sb_info *sbi, block_t start_blk)
+{
+	write_normal_summaries(sbi, start_blk, CURSEG_HOT_NODE);
+}
+
+int lookup_journal_in_cursum(struct f2fs_journal *journal, int type,
+					unsigned int val, int alloc)
+{
+	int i;
+
+	if (type == NAT_JOURNAL) {
+		for (i = 0; i < nats_in_cursum(journal); i++) {
+			if (le32_to_cpu(nid_in_journal(journal, i)) == val)
+				return i;
+		}
+		if (alloc && __has_cursum_space(journal, 1, NAT_JOURNAL))
+			return update_nats_in_cursum(journal, 1);
+	} else if (type == SIT_JOURNAL) {
+		for (i = 0; i < sits_in_cursum(journal); i++)
+			if (le32_to_cpu(segno_in_journal(journal, i)) == val)
+				return i;
+		if (alloc && __has_cursum_space(journal, 1, SIT_JOURNAL))
+			return update_sits_in_cursum(journal, 1);
+	}
+	return -1;
+}
+
+static struct page *get_current_sit_page(struct f2fs_sb_info *sbi,
+					unsigned int segno)
+{
+	return get_meta_page(sbi, current_sit_addr(sbi, segno));
+}
+
+static struct page *get_next_sit_page(struct f2fs_sb_info *sbi,
+					unsigned int start)
+{
+	struct sit_info *sit_i = SIT_I(sbi);
+	struct page *page;
+	pgoff_t src_off, dst_off;
+
+	src_off = current_sit_addr(sbi, start);
+	dst_off = next_sit_addr(sbi, src_off);
+
+	page = grab_meta_page(sbi, dst_off);
+	seg_info_to_sit_page(sbi, page, start);
+
+	set_page_dirty(page);
+	set_to_next_sit(sit_i, start);
+
+	return page;
+}
+
+static struct sit_entry_set *grab_sit_entry_set(void)
+{
+	struct sit_entry_set *ses =
+			f2fs_kmem_cache_alloc(sit_entry_set_slab, GFP_NOFS);
+
+	ses->entry_cnt = 0;
+	INIT_LIST_HEAD(&ses->set_list);
+	return ses;
+}
+
+static void release_sit_entry_set(struct sit_entry_set *ses)
+{
+	list_del(&ses->set_list);
+	kmem_cache_free(sit_entry_set_slab, ses);
+}
+
+static void adjust_sit_entry_set(struct sit_entry_set *ses,
+						struct list_head *head)
+{
+	struct sit_entry_set *next = ses;
+
+	if (list_is_last(&ses->set_list, head))
+		return;
+
+	list_for_each_entry_continue(next, head, set_list)
+		if (ses->entry_cnt <= next->entry_cnt)
+			break;
+
+	list_move_tail(&ses->set_list, &next->set_list);
+}
+
+static void add_sit_entry(unsigned int segno, struct list_head *head)
+{
+	struct sit_entry_set *ses;
+	unsigned int start_segno = START_SEGNO(segno);
+
+	list_for_each_entry(ses, head, set_list) {
+		if (ses->start_segno == start_segno) {
+			ses->entry_cnt++;
+			adjust_sit_entry_set(ses, head);
+			return;
+		}
+	}
+
+	ses = grab_sit_entry_set();
+
+	ses->start_segno = start_segno;
+	ses->entry_cnt++;
+	list_add(&ses->set_list, head);
+}
+
+static void add_sits_in_set(struct f2fs_sb_info *sbi)
+{
+	struct f2fs_sm_info *sm_info = SM_I(sbi);
+	struct list_head *set_list = &sm_info->sit_entry_set;
+	unsigned long *bitmap = SIT_I(sbi)->dirty_sentries_bitmap;
+	unsigned int segno;
+
+	for_each_set_bit(segno, bitmap, MAIN_SEGS(sbi))
+		add_sit_entry(segno, set_list);
+}
+
+static void remove_sits_in_journal(struct f2fs_sb_info *sbi)
+{
+	struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_COLD_DATA);
+	struct f2fs_journal *journal = curseg->journal;
+	int i;
+
+	down_write(&curseg->journal_rwsem);
+	for (i = 0; i < sits_in_cursum(journal); i++) {
+		unsigned int segno;
+		bool dirtied;
+
+		segno = le32_to_cpu(segno_in_journal(journal, i));
+		dirtied = __mark_sit_entry_dirty(sbi, segno);
+
+		if (!dirtied)
+			add_sit_entry(segno, &SM_I(sbi)->sit_entry_set);
+	}
+	update_sits_in_cursum(journal, -i);
+	up_write(&curseg->journal_rwsem);
+}
+
+/*
+ * CP calls this function, which flushes SIT entries including sit_journal,
+ * and moves prefree segs to free segs.
+ */
+void flush_sit_entries(struct f2fs_sb_info *sbi, struct cp_control *cpc)
+{
+	struct sit_info *sit_i = SIT_I(sbi);
+	unsigned long *bitmap = sit_i->dirty_sentries_bitmap;
+	struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_COLD_DATA);
+	struct f2fs_journal *journal = curseg->journal;
+	struct sit_entry_set *ses, *tmp;
+	struct list_head *head = &SM_I(sbi)->sit_entry_set;
+	bool to_journal = true;
+	struct seg_entry *se;
+
+	down_write(&sit_i->sentry_lock);
+
+	if (!sit_i->dirty_sentries)
+		goto out;
+
+	/*
+	 * add and account sit entries of dirty bitmap in sit entry
+	 * set temporarily
+	 */
+	add_sits_in_set(sbi);
+
+	/*
+	 * if there are no enough space in journal to store dirty sit
+	 * entries, remove all entries from journal and add and account
+	 * them in sit entry set.
+	 */
+	if (!__has_cursum_space(journal, sit_i->dirty_sentries, SIT_JOURNAL))
+		remove_sits_in_journal(sbi);
+
+	/*
+	 * there are two steps to flush sit entries:
+	 * #1, flush sit entries to journal in current cold data summary block.
+	 * #2, flush sit entries to sit page.
+	 */
+	list_for_each_entry_safe(ses, tmp, head, set_list) {
+		struct page *page = NULL;
+		struct f2fs_sit_block *raw_sit = NULL;
+		unsigned int start_segno = ses->start_segno;
+		unsigned int end = min(start_segno + SIT_ENTRY_PER_BLOCK,
+						(unsigned long)MAIN_SEGS(sbi));
+		unsigned int segno = start_segno;
+
+		if (to_journal &&
+			!__has_cursum_space(journal, ses->entry_cnt, SIT_JOURNAL))
+			to_journal = false;
+
+		if (to_journal) {
+			down_write(&curseg->journal_rwsem);
+		} else {
+			page = get_next_sit_page(sbi, start_segno);
+			raw_sit = page_address(page);
+		}
+
+		/* flush dirty sit entries in region of current sit set */
+		for_each_set_bit_from(segno, bitmap, end) {
+			int offset, sit_offset;
+
+			se = get_seg_entry(sbi, segno);
+
+			/* add discard candidates */
+			if (!(cpc->reason & CP_DISCARD)) {
+				cpc->trim_start = segno;
+				add_discard_addrs(sbi, cpc, false);
+			}
+
+			if (to_journal) {
+				offset = lookup_journal_in_cursum(journal,
+							SIT_JOURNAL, segno, 1);
+				f2fs_bug_on(sbi, offset < 0);
+				segno_in_journal(journal, offset) =
+							cpu_to_le32(segno);
+				seg_info_to_raw_sit(se,
+					&sit_in_journal(journal, offset));
+			} else {
+				sit_offset = SIT_ENTRY_OFFSET(sit_i, segno);
+				seg_info_to_raw_sit(se,
+						&raw_sit->entries[sit_offset]);
+			}
+
+			__clear_bit(segno, bitmap);
+			sit_i->dirty_sentries--;
+			ses->entry_cnt--;
+		}
+
+		if (to_journal)
+			up_write(&curseg->journal_rwsem);
+		else
+			f2fs_put_page(page, 1);
+
+		f2fs_bug_on(sbi, ses->entry_cnt);
+		release_sit_entry_set(ses);
+	}
+
+	f2fs_bug_on(sbi, !list_empty(head));
+	f2fs_bug_on(sbi, sit_i->dirty_sentries);
+out:
+	if (cpc->reason & CP_DISCARD) {
+		__u64 trim_start = cpc->trim_start;
+
+		for (; cpc->trim_start <= cpc->trim_end; cpc->trim_start++)
+			add_discard_addrs(sbi, cpc, false);
+
+		cpc->trim_start = trim_start;
+	}
+	up_write(&sit_i->sentry_lock);
+
+	set_prefree_as_free_segments(sbi);
+}
+
+static int build_sit_info(struct f2fs_sb_info *sbi)
+{
+	struct f2fs_super_block *raw_super = F2FS_RAW_SUPER(sbi);
+	struct sit_info *sit_i;
+	unsigned int sit_segs, start;
+	char *src_bitmap;
+	unsigned int bitmap_size;
+
+	/* allocate memory for SIT information */
+	sit_i = f2fs_kzalloc(sbi, sizeof(struct sit_info), GFP_KERNEL);
+	if (!sit_i)
+		return -ENOMEM;
+
+	SM_I(sbi)->sit_info = sit_i;
+
+	sit_i->sentries = f2fs_kvzalloc(sbi, MAIN_SEGS(sbi) *
+					sizeof(struct seg_entry), GFP_KERNEL);
+	if (!sit_i->sentries)
+		return -ENOMEM;
+
+	bitmap_size = f2fs_bitmap_size(MAIN_SEGS(sbi));
+	sit_i->dirty_sentries_bitmap = f2fs_kvzalloc(sbi, bitmap_size,
+								GFP_KERNEL);
+	if (!sit_i->dirty_sentries_bitmap)
+		return -ENOMEM;
+
+	for (start = 0; start < MAIN_SEGS(sbi); start++) {
+		sit_i->sentries[start].cur_valid_map
+			= f2fs_kzalloc(sbi, SIT_VBLOCK_MAP_SIZE, GFP_KERNEL);
+		sit_i->sentries[start].ckpt_valid_map
+			= f2fs_kzalloc(sbi, SIT_VBLOCK_MAP_SIZE, GFP_KERNEL);
+		if (!sit_i->sentries[start].cur_valid_map ||
+				!sit_i->sentries[start].ckpt_valid_map)
+			return -ENOMEM;
+
+#ifdef CONFIG_F2FS_CHECK_FS
+		sit_i->sentries[start].cur_valid_map_mir
+			= f2fs_kzalloc(sbi, SIT_VBLOCK_MAP_SIZE, GFP_KERNEL);
+		if (!sit_i->sentries[start].cur_valid_map_mir)
+			return -ENOMEM;
+#endif
+
+		if (f2fs_discard_en(sbi)) {
+			sit_i->sentries[start].discard_map
+				= f2fs_kzalloc(sbi, SIT_VBLOCK_MAP_SIZE,
+								GFP_KERNEL);
+			if (!sit_i->sentries[start].discard_map)
+				return -ENOMEM;
+		}
+	}
+
+	sit_i->tmp_map = f2fs_kzalloc(sbi, SIT_VBLOCK_MAP_SIZE, GFP_KERNEL);
+	if (!sit_i->tmp_map)
+		return -ENOMEM;
+
+	if (sbi->segs_per_sec > 1) {
+		sit_i->sec_entries = f2fs_kvzalloc(sbi, MAIN_SECS(sbi) *
+					sizeof(struct sec_entry), GFP_KERNEL);
+		if (!sit_i->sec_entries)
+			return -ENOMEM;
+	}
+
+	/* get information related with SIT */
+	sit_segs = le32_to_cpu(raw_super->segment_count_sit) >> 1;
+
+	/* setup SIT bitmap from ckeckpoint pack */
+	bitmap_size = __bitmap_size(sbi, SIT_BITMAP);
+	src_bitmap = __bitmap_ptr(sbi, SIT_BITMAP);
+
+	sit_i->sit_bitmap = kmemdup(src_bitmap, bitmap_size, GFP_KERNEL);
+	if (!sit_i->sit_bitmap)
+		return -ENOMEM;
+
+#ifdef CONFIG_F2FS_CHECK_FS
+	sit_i->sit_bitmap_mir = kmemdup(src_bitmap, bitmap_size, GFP_KERNEL);
+	if (!sit_i->sit_bitmap_mir)
+		return -ENOMEM;
+#endif
+
+	/* init SIT information */
+	sit_i->s_ops = &default_salloc_ops;
+
+	sit_i->sit_base_addr = le32_to_cpu(raw_super->sit_blkaddr);
+	sit_i->sit_blocks = sit_segs << sbi->log_blocks_per_seg;
+	sit_i->written_valid_blocks = 0;
+	sit_i->bitmap_size = bitmap_size;
+	sit_i->dirty_sentries = 0;
+	sit_i->sents_per_block = SIT_ENTRY_PER_BLOCK;
+	sit_i->elapsed_time = le64_to_cpu(sbi->ckpt->elapsed_time);
+	sit_i->mounted_time = ktime_get_real_seconds();
+	init_rwsem(&sit_i->sentry_lock);
+	return 0;
+}
+
+static int build_free_segmap(struct f2fs_sb_info *sbi)
+{
+	struct free_segmap_info *free_i;
+	unsigned int bitmap_size, sec_bitmap_size;
+
+	/* allocate memory for free segmap information */
+	free_i = f2fs_kzalloc(sbi, sizeof(struct free_segmap_info), GFP_KERNEL);
+	if (!free_i)
+		return -ENOMEM;
+
+	SM_I(sbi)->free_info = free_i;
+
+	bitmap_size = f2fs_bitmap_size(MAIN_SEGS(sbi));
+	free_i->free_segmap = f2fs_kvmalloc(sbi, bitmap_size, GFP_KERNEL);
+	if (!free_i->free_segmap)
+		return -ENOMEM;
+
+	sec_bitmap_size = f2fs_bitmap_size(MAIN_SECS(sbi));
+	free_i->free_secmap = f2fs_kvmalloc(sbi, sec_bitmap_size, GFP_KERNEL);
+	if (!free_i->free_secmap)
+		return -ENOMEM;
+
+	/* set all segments as dirty temporarily */
+	memset(free_i->free_segmap, 0xff, bitmap_size);
+	memset(free_i->free_secmap, 0xff, sec_bitmap_size);
+
+	/* init free segmap information */
+	free_i->start_segno = GET_SEGNO_FROM_SEG0(sbi, MAIN_BLKADDR(sbi));
+	free_i->free_segments = 0;
+	free_i->free_sections = 0;
+	spin_lock_init(&free_i->segmap_lock);
+	return 0;
+}
+
+static int build_curseg(struct f2fs_sb_info *sbi)
+{
+	struct curseg_info *array;
+	int i;
+
+	array = f2fs_kzalloc(sbi, sizeof(*array) * NR_CURSEG_TYPE, GFP_KERNEL);
+	if (!array)
+		return -ENOMEM;
+
+	SM_I(sbi)->curseg_array = array;
+
+	for (i = 0; i < NR_CURSEG_TYPE; i++) {
+		mutex_init(&array[i].curseg_mutex);
+		array[i].sum_blk = f2fs_kzalloc(sbi, PAGE_SIZE, GFP_KERNEL);
+		if (!array[i].sum_blk)
+			return -ENOMEM;
+		init_rwsem(&array[i].journal_rwsem);
+		array[i].journal = f2fs_kzalloc(sbi,
+				sizeof(struct f2fs_journal), GFP_KERNEL);
+		if (!array[i].journal)
+			return -ENOMEM;
+		array[i].segno = NULL_SEGNO;
+		array[i].next_blkoff = 0;
+	}
+	return restore_curseg_summaries(sbi);
+}
+
+static int build_sit_entries(struct f2fs_sb_info *sbi)
+{
+	struct sit_info *sit_i = SIT_I(sbi);
+	struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_COLD_DATA);
+	struct f2fs_journal *journal = curseg->journal;
+	struct seg_entry *se;
+	struct f2fs_sit_entry sit;
+	int sit_blk_cnt = SIT_BLK_CNT(sbi);
+	unsigned int i, start, end;
+	unsigned int readed, start_blk = 0;
+	int err = 0;
+	block_t total_node_blocks = 0;
+
+	do {
+		readed = ra_meta_pages(sbi, start_blk, BIO_MAX_PAGES,
+							META_SIT, true);
+
+		start = start_blk * sit_i->sents_per_block;
+		end = (start_blk + readed) * sit_i->sents_per_block;
+
+		for (; start < end && start < MAIN_SEGS(sbi); start++) {
+			struct f2fs_sit_block *sit_blk;
+			struct page *page;
+
+			se = &sit_i->sentries[start];
+			page = get_current_sit_page(sbi, start);
+			sit_blk = (struct f2fs_sit_block *)page_address(page);
+			sit = sit_blk->entries[SIT_ENTRY_OFFSET(sit_i, start)];
+			f2fs_put_page(page, 1);
+
+			err = check_block_count(sbi, start, &sit);
+			if (err)
+				return err;
+			seg_info_from_raw_sit(se, &sit);
+			if (IS_NODESEG(se->type))
+				total_node_blocks += se->valid_blocks;
+
+			/* build discard map only one time */
+			if (f2fs_discard_en(sbi)) {
+				if (is_set_ckpt_flags(sbi, CP_TRIMMED_FLAG)) {
+					memset(se->discard_map, 0xff,
+						SIT_VBLOCK_MAP_SIZE);
+				} else {
+					memcpy(se->discard_map,
+						se->cur_valid_map,
+						SIT_VBLOCK_MAP_SIZE);
+					sbi->discard_blks +=
+						sbi->blocks_per_seg -
+						se->valid_blocks;
+				}
+			}
+
+			if (sbi->segs_per_sec > 1)
+				get_sec_entry(sbi, start)->valid_blocks +=
+							se->valid_blocks;
+		}
+		start_blk += readed;
+	} while (start_blk < sit_blk_cnt);
+
+	down_read(&curseg->journal_rwsem);
+	for (i = 0; i < sits_in_cursum(journal); i++) {
+		unsigned int old_valid_blocks;
+
+		start = le32_to_cpu(segno_in_journal(journal, i));
+		if (start >= MAIN_SEGS(sbi)) {
+			f2fs_msg(sbi->sb, KERN_ERR,
+					"Wrong journal entry on segno %u",
+					start);
+			set_sbi_flag(sbi, SBI_NEED_FSCK);
+			err = -EFSCORRUPTED;
+			break;
+		}
+
+		se = &sit_i->sentries[start];
+		sit = sit_in_journal(journal, i);
+
+		old_valid_blocks = se->valid_blocks;
+		if (IS_NODESEG(se->type))
+			total_node_blocks -= old_valid_blocks;
+
+		err = check_block_count(sbi, start, &sit);
+		if (err)
+			break;
+		seg_info_from_raw_sit(se, &sit);
+		if (IS_NODESEG(se->type))
+			total_node_blocks += se->valid_blocks;
+
+		if (f2fs_discard_en(sbi)) {
+			if (is_set_ckpt_flags(sbi, CP_TRIMMED_FLAG)) {
+				memset(se->discard_map, 0xff,
+							SIT_VBLOCK_MAP_SIZE);
+			} else {
+				memcpy(se->discard_map, se->cur_valid_map,
+							SIT_VBLOCK_MAP_SIZE);
+				sbi->discard_blks += old_valid_blocks -
+							se->valid_blocks;
+			}
+		}
+
+		if (sbi->segs_per_sec > 1)
+			get_sec_entry(sbi, start)->valid_blocks +=
+				se->valid_blocks - old_valid_blocks;
+	}
+	up_read(&curseg->journal_rwsem);
+
+	if (!err && total_node_blocks != valid_node_count(sbi)) {
+		f2fs_msg(sbi->sb, KERN_ERR,
+			"SIT is corrupted node# %u vs %u",
+			total_node_blocks, valid_node_count(sbi));
+		set_sbi_flag(sbi, SBI_NEED_FSCK);
+		err = -EFSCORRUPTED;
+	}
+
+	return err;
+}
+
+static void init_free_segmap(struct f2fs_sb_info *sbi)
+{
+	unsigned int start;
+	int type;
+
+	for (start = 0; start < MAIN_SEGS(sbi); start++) {
+		struct seg_entry *sentry = get_seg_entry(sbi, start);
+		if (!sentry->valid_blocks)
+			__set_free(sbi, start);
+		else
+			SIT_I(sbi)->written_valid_blocks +=
+						sentry->valid_blocks;
+	}
+
+	/* set use the current segments */
+	for (type = CURSEG_HOT_DATA; type <= CURSEG_COLD_NODE; type++) {
+		struct curseg_info *curseg_t = CURSEG_I(sbi, type);
+		__set_test_and_inuse(sbi, curseg_t->segno);
+	}
+}
+
+static void init_dirty_segmap(struct f2fs_sb_info *sbi)
+{
+	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
+	struct free_segmap_info *free_i = FREE_I(sbi);
+	unsigned int segno = 0, offset = 0;
+	unsigned short valid_blocks;
+
+	while (1) {
+		/* find dirty segment based on free segmap */
+		segno = find_next_inuse(free_i, MAIN_SEGS(sbi), offset);
+		if (segno >= MAIN_SEGS(sbi))
+			break;
+		offset = segno + 1;
+		valid_blocks = get_valid_blocks(sbi, segno, false);
+		if (valid_blocks == sbi->blocks_per_seg || !valid_blocks)
+			continue;
+		if (valid_blocks > sbi->blocks_per_seg) {
+			f2fs_bug_on(sbi, 1);
+			continue;
+		}
+		mutex_lock(&dirty_i->seglist_lock);
+		__locate_dirty_segment(sbi, segno, DIRTY);
+		mutex_unlock(&dirty_i->seglist_lock);
+	}
+}
+
+static int init_victim_secmap(struct f2fs_sb_info *sbi)
+{
+	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
+	unsigned int bitmap_size = f2fs_bitmap_size(MAIN_SECS(sbi));
+
+	dirty_i->victim_secmap = f2fs_kvzalloc(sbi, bitmap_size, GFP_KERNEL);
+	if (!dirty_i->victim_secmap)
+		return -ENOMEM;
+	return 0;
+}
+
+static int build_dirty_segmap(struct f2fs_sb_info *sbi)
+{
+	struct dirty_seglist_info *dirty_i;
+	unsigned int bitmap_size, i;
+
+	/* allocate memory for dirty segments list information */
+	dirty_i = f2fs_kzalloc(sbi, sizeof(struct dirty_seglist_info),
+								GFP_KERNEL);
+	if (!dirty_i)
+		return -ENOMEM;
+
+	SM_I(sbi)->dirty_info = dirty_i;
+	mutex_init(&dirty_i->seglist_lock);
+
+	bitmap_size = f2fs_bitmap_size(MAIN_SEGS(sbi));
+
+	for (i = 0; i < NR_DIRTY_TYPE; i++) {
+		dirty_i->dirty_segmap[i] = f2fs_kvzalloc(sbi, bitmap_size,
+								GFP_KERNEL);
+		if (!dirty_i->dirty_segmap[i])
+			return -ENOMEM;
+	}
+
+	init_dirty_segmap(sbi);
+	return init_victim_secmap(sbi);
+}
+
+static int sanity_check_curseg(struct f2fs_sb_info *sbi)
+{
+	int i;
+
+	/*
+	 * In LFS/SSR curseg, .next_blkoff should point to an unused blkaddr;
+	 * In LFS curseg, all blkaddr after .next_blkoff should be unused.
+	 */
+	for (i = 0; i < NO_CHECK_TYPE; i++) {
+		struct curseg_info *curseg = CURSEG_I(sbi, i);
+		struct seg_entry *se = get_seg_entry(sbi, curseg->segno);
+		unsigned int blkofs = curseg->next_blkoff;
+
+		if (f2fs_test_bit(blkofs, se->cur_valid_map))
+			goto out;
+
+		if (curseg->alloc_type == SSR)
+			continue;
+
+		for (blkofs += 1; blkofs < sbi->blocks_per_seg; blkofs++) {
+			if (!f2fs_test_bit(blkofs, se->cur_valid_map))
+				continue;
+out:
+			f2fs_msg(sbi->sb, KERN_ERR,
+				"Current segment's next free block offset is "
+				"inconsistent with bitmap, logtype:%u, "
+				"segno:%u, type:%u, next_blkoff:%u, blkofs:%u",
+				i, curseg->segno, curseg->alloc_type,
+				curseg->next_blkoff, blkofs);
+			return -EFSCORRUPTED;
+		}
+	}
+	return 0;
+}
+
+/*
+ * Update min, max modified time for cost-benefit GC algorithm
+ */
+static void init_min_max_mtime(struct f2fs_sb_info *sbi)
+{
+	struct sit_info *sit_i = SIT_I(sbi);
+	unsigned int segno;
+
+	down_write(&sit_i->sentry_lock);
+
+	sit_i->min_mtime = LLONG_MAX;
+
+	for (segno = 0; segno < MAIN_SEGS(sbi); segno += sbi->segs_per_sec) {
+		unsigned int i;
+		unsigned long long mtime = 0;
+
+		for (i = 0; i < sbi->segs_per_sec; i++)
+			mtime += get_seg_entry(sbi, segno + i)->mtime;
+
+		mtime = div_u64(mtime, sbi->segs_per_sec);
+
+		if (sit_i->min_mtime > mtime)
+			sit_i->min_mtime = mtime;
+	}
+	sit_i->max_mtime = get_mtime(sbi);
+	up_write(&sit_i->sentry_lock);
+}
+
+int build_segment_manager(struct f2fs_sb_info *sbi)
+{
+	struct f2fs_super_block *raw_super = F2FS_RAW_SUPER(sbi);
+	struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
+	struct f2fs_sm_info *sm_info;
+	int err;
+
+	sm_info = f2fs_kzalloc(sbi, sizeof(struct f2fs_sm_info), GFP_KERNEL);
+	if (!sm_info)
+		return -ENOMEM;
+
+	/* init sm info */
+	sbi->sm_info = sm_info;
+	sm_info->seg0_blkaddr = le32_to_cpu(raw_super->segment0_blkaddr);
+	sm_info->main_blkaddr = le32_to_cpu(raw_super->main_blkaddr);
+	sm_info->segment_count = le32_to_cpu(raw_super->segment_count);
+	sm_info->reserved_segments = le32_to_cpu(ckpt->rsvd_segment_count);
+	sm_info->ovp_segments = le32_to_cpu(ckpt->overprov_segment_count);
+	sm_info->main_segments = le32_to_cpu(raw_super->segment_count_main);
+	sm_info->ssa_blkaddr = le32_to_cpu(raw_super->ssa_blkaddr);
+	sm_info->rec_prefree_segments = sm_info->main_segments *
+					DEF_RECLAIM_PREFREE_SEGMENTS / 100;
+	if (sm_info->rec_prefree_segments > DEF_MAX_RECLAIM_PREFREE_SEGMENTS)
+		sm_info->rec_prefree_segments = DEF_MAX_RECLAIM_PREFREE_SEGMENTS;
+
+	if (!test_opt(sbi, LFS))
+		sm_info->ipu_policy = 1 << F2FS_IPU_FSYNC;
+	sm_info->min_ipu_util = DEF_MIN_IPU_UTIL;
+	sm_info->min_fsync_blocks = DEF_MIN_FSYNC_BLOCKS;
+	sm_info->min_hot_blocks = DEF_MIN_HOT_BLOCKS;
+	sm_info->min_ssr_sections = reserved_sections(sbi);
+
+	INIT_LIST_HEAD(&sm_info->sit_entry_set);
+
+	init_rwsem(&sm_info->curseg_lock);
+
+	if (!f2fs_readonly(sbi->sb)) {
+		err = create_flush_cmd_control(sbi);
+		if (err)
+			return err;
+	}
+
+	err = create_discard_cmd_control(sbi);
+	if (err)
+		return err;
+
+	err = build_sit_info(sbi);
+	if (err)
+		return err;
+	err = build_free_segmap(sbi);
+	if (err)
+		return err;
+	err = build_curseg(sbi);
+	if (err)
+		return err;
+
+	/* reinit free segmap based on SIT */
+	err = build_sit_entries(sbi);
+	if (err)
+		return err;
+
+	init_free_segmap(sbi);
+	err = build_dirty_segmap(sbi);
+	if (err)
+		return err;
+
+	err = sanity_check_curseg(sbi);
+	if (err)
+		return err;
+
+	init_min_max_mtime(sbi);
+	return 0;
+}
+
+static void discard_dirty_segmap(struct f2fs_sb_info *sbi,
+		enum dirty_type dirty_type)
+{
+	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
+
+	mutex_lock(&dirty_i->seglist_lock);
+	kvfree(dirty_i->dirty_segmap[dirty_type]);
+	dirty_i->nr_dirty[dirty_type] = 0;
+	mutex_unlock(&dirty_i->seglist_lock);
+}
+
+static void destroy_victim_secmap(struct f2fs_sb_info *sbi)
+{
+	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
+	kvfree(dirty_i->victim_secmap);
+}
+
+static void destroy_dirty_segmap(struct f2fs_sb_info *sbi)
+{
+	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
+	int i;
+
+	if (!dirty_i)
+		return;
+
+	/* discard pre-free/dirty segments list */
+	for (i = 0; i < NR_DIRTY_TYPE; i++)
+		discard_dirty_segmap(sbi, i);
+
+	destroy_victim_secmap(sbi);
+	SM_I(sbi)->dirty_info = NULL;
+	kfree(dirty_i);
+}
+
+static void destroy_curseg(struct f2fs_sb_info *sbi)
+{
+	struct curseg_info *array = SM_I(sbi)->curseg_array;
+	int i;
+
+	if (!array)
+		return;
+	SM_I(sbi)->curseg_array = NULL;
+	for (i = 0; i < NR_CURSEG_TYPE; i++) {
+		kfree(array[i].sum_blk);
+		kfree(array[i].journal);
+	}
+	kfree(array);
+}
+
+static void destroy_free_segmap(struct f2fs_sb_info *sbi)
+{
+	struct free_segmap_info *free_i = SM_I(sbi)->free_info;
+	if (!free_i)
+		return;
+	SM_I(sbi)->free_info = NULL;
+	kvfree(free_i->free_segmap);
+	kvfree(free_i->free_secmap);
+	kfree(free_i);
+}
+
+static void destroy_sit_info(struct f2fs_sb_info *sbi)
+{
+	struct sit_info *sit_i = SIT_I(sbi);
+	unsigned int start;
+
+	if (!sit_i)
+		return;
+
+	if (sit_i->sentries) {
+		for (start = 0; start < MAIN_SEGS(sbi); start++) {
+			kfree(sit_i->sentries[start].cur_valid_map);
+#ifdef CONFIG_F2FS_CHECK_FS
+			kfree(sit_i->sentries[start].cur_valid_map_mir);
+#endif
+			kfree(sit_i->sentries[start].ckpt_valid_map);
+			kfree(sit_i->sentries[start].discard_map);
+		}
+	}
+	kfree(sit_i->tmp_map);
+
+	kvfree(sit_i->sentries);
+	kvfree(sit_i->sec_entries);
+	kvfree(sit_i->dirty_sentries_bitmap);
+
+	SM_I(sbi)->sit_info = NULL;
+	kfree(sit_i->sit_bitmap);
+#ifdef CONFIG_F2FS_CHECK_FS
+	kfree(sit_i->sit_bitmap_mir);
+#endif
+	kfree(sit_i);
+}
+
+void destroy_segment_manager(struct f2fs_sb_info *sbi)
+{
+	struct f2fs_sm_info *sm_info = SM_I(sbi);
+
+	if (!sm_info)
+		return;
+	destroy_flush_cmd_control(sbi, true);
+	destroy_discard_cmd_control(sbi);
+	destroy_dirty_segmap(sbi);
+	destroy_curseg(sbi);
+	destroy_free_segmap(sbi);
+	destroy_sit_info(sbi);
+	sbi->sm_info = NULL;
+	kfree(sm_info);
+}
+
+int __init create_segment_manager_caches(void)
+{
+	discard_entry_slab = f2fs_kmem_cache_create("discard_entry",
+			sizeof(struct discard_entry));
+	if (!discard_entry_slab)
+		goto fail;
+
+	discard_cmd_slab = f2fs_kmem_cache_create("discard_cmd",
+			sizeof(struct discard_cmd));
+	if (!discard_cmd_slab)
+		goto destroy_discard_entry;
+
+	sit_entry_set_slab = f2fs_kmem_cache_create("sit_entry_set",
+			sizeof(struct sit_entry_set));
+	if (!sit_entry_set_slab)
+		goto destroy_discard_cmd;
+
+	inmem_entry_slab = f2fs_kmem_cache_create("inmem_page_entry",
+			sizeof(struct inmem_pages));
+	if (!inmem_entry_slab)
+		goto destroy_sit_entry_set;
+	return 0;
+
+destroy_sit_entry_set:
+	kmem_cache_destroy(sit_entry_set_slab);
+destroy_discard_cmd:
+	kmem_cache_destroy(discard_cmd_slab);
+destroy_discard_entry:
+	kmem_cache_destroy(discard_entry_slab);
+fail:
+	return -ENOMEM;
+}
+
+void destroy_segment_manager_caches(void)
+{
+	kmem_cache_destroy(sit_entry_set_slab);
+	kmem_cache_destroy(discard_cmd_slab);
+	kmem_cache_destroy(discard_entry_slab);
+	kmem_cache_destroy(inmem_entry_slab);
+}
diff --git a/src/kernel/linux/v4.14/fs/f2fs/segment.h b/src/kernel/linux/v4.14/fs/f2fs/segment.h
new file mode 100644
index 0000000..72715a6
--- /dev/null
+++ b/src/kernel/linux/v4.14/fs/f2fs/segment.h
@@ -0,0 +1,855 @@
+/*
+ * fs/f2fs/segment.h
+ *
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ *             http://www.samsung.com/
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/blkdev.h>
+#include <linux/backing-dev.h>
+
+/* constant macro */
+#define NULL_SEGNO			((unsigned int)(~0))
+#define NULL_SECNO			((unsigned int)(~0))
+
+#define DEF_RECLAIM_PREFREE_SEGMENTS	5	/* 5% over total segments */
+#define DEF_MAX_RECLAIM_PREFREE_SEGMENTS	4096	/* 8GB in maximum */
+
+#define F2FS_MIN_SEGMENTS	9 /* SB + 2 (CP + SIT + NAT) + SSA + MAIN */
+
+/* L: Logical segment # in volume, R: Relative segment # in main area */
+#define GET_L2R_SEGNO(free_i, segno)	((segno) - (free_i)->start_segno)
+#define GET_R2L_SEGNO(free_i, segno)	((segno) + (free_i)->start_segno)
+
+#define IS_DATASEG(t)	((t) <= CURSEG_COLD_DATA)
+#define IS_NODESEG(t)	((t) >= CURSEG_HOT_NODE)
+
+#define IS_HOT(t)	((t) == CURSEG_HOT_NODE || (t) == CURSEG_HOT_DATA)
+#define IS_WARM(t)	((t) == CURSEG_WARM_NODE || (t) == CURSEG_WARM_DATA)
+#define IS_COLD(t)	((t) == CURSEG_COLD_NODE || (t) == CURSEG_COLD_DATA)
+
+#define IS_CURSEG(sbi, seg)						\
+	(((seg) == CURSEG_I(sbi, CURSEG_HOT_DATA)->segno) ||	\
+	 ((seg) == CURSEG_I(sbi, CURSEG_WARM_DATA)->segno) ||	\
+	 ((seg) == CURSEG_I(sbi, CURSEG_COLD_DATA)->segno) ||	\
+	 ((seg) == CURSEG_I(sbi, CURSEG_HOT_NODE)->segno) ||	\
+	 ((seg) == CURSEG_I(sbi, CURSEG_WARM_NODE)->segno) ||	\
+	 ((seg) == CURSEG_I(sbi, CURSEG_COLD_NODE)->segno))
+
+#define IS_CURSEC(sbi, secno)						\
+	(((secno) == CURSEG_I(sbi, CURSEG_HOT_DATA)->segno /		\
+	  (sbi)->segs_per_sec) ||	\
+	 ((secno) == CURSEG_I(sbi, CURSEG_WARM_DATA)->segno /		\
+	  (sbi)->segs_per_sec) ||	\
+	 ((secno) == CURSEG_I(sbi, CURSEG_COLD_DATA)->segno /		\
+	  (sbi)->segs_per_sec) ||	\
+	 ((secno) == CURSEG_I(sbi, CURSEG_HOT_NODE)->segno /		\
+	  (sbi)->segs_per_sec) ||	\
+	 ((secno) == CURSEG_I(sbi, CURSEG_WARM_NODE)->segno /		\
+	  (sbi)->segs_per_sec) ||	\
+	 ((secno) == CURSEG_I(sbi, CURSEG_COLD_NODE)->segno /		\
+	  (sbi)->segs_per_sec))	\
+
+#define MAIN_BLKADDR(sbi)						\
+	(SM_I(sbi) ? SM_I(sbi)->main_blkaddr : 				\
+		le32_to_cpu(F2FS_RAW_SUPER(sbi)->main_blkaddr))
+#define SEG0_BLKADDR(sbi)						\
+	(SM_I(sbi) ? SM_I(sbi)->seg0_blkaddr : 				\
+		le32_to_cpu(F2FS_RAW_SUPER(sbi)->segment0_blkaddr))
+
+#define MAIN_SEGS(sbi)	(SM_I(sbi)->main_segments)
+#define MAIN_SECS(sbi)	((sbi)->total_sections)
+
+#define TOTAL_SEGS(sbi)							\
+	(SM_I(sbi) ? SM_I(sbi)->segment_count : 				\
+		le32_to_cpu(F2FS_RAW_SUPER(sbi)->segment_count))
+#define TOTAL_BLKS(sbi)	(TOTAL_SEGS(sbi) << (sbi)->log_blocks_per_seg)
+
+#define MAX_BLKADDR(sbi)	(SEG0_BLKADDR(sbi) + TOTAL_BLKS(sbi))
+#define SEGMENT_SIZE(sbi)	(1ULL << ((sbi)->log_blocksize +	\
+					(sbi)->log_blocks_per_seg))
+
+#define START_BLOCK(sbi, segno)	(SEG0_BLKADDR(sbi) +			\
+	 (GET_R2L_SEGNO(FREE_I(sbi), segno) << (sbi)->log_blocks_per_seg))
+
+#define NEXT_FREE_BLKADDR(sbi, curseg)					\
+	(START_BLOCK(sbi, (curseg)->segno) + (curseg)->next_blkoff)
+
+#define GET_SEGOFF_FROM_SEG0(sbi, blk_addr)	((blk_addr) - SEG0_BLKADDR(sbi))
+#define GET_SEGNO_FROM_SEG0(sbi, blk_addr)				\
+	(GET_SEGOFF_FROM_SEG0(sbi, blk_addr) >> (sbi)->log_blocks_per_seg)
+#define GET_BLKOFF_FROM_SEG0(sbi, blk_addr)				\
+	(GET_SEGOFF_FROM_SEG0(sbi, blk_addr) & ((sbi)->blocks_per_seg - 1))
+
+#define GET_SEGNO(sbi, blk_addr)					\
+	((!is_valid_data_blkaddr(sbi, blk_addr)) ?			\
+	NULL_SEGNO : GET_L2R_SEGNO(FREE_I(sbi),			\
+		GET_SEGNO_FROM_SEG0(sbi, blk_addr)))
+#define BLKS_PER_SEC(sbi)					\
+	((sbi)->segs_per_sec * (sbi)->blocks_per_seg)
+#define GET_SEC_FROM_SEG(sbi, segno)				\
+	((segno) / (sbi)->segs_per_sec)
+#define GET_SEG_FROM_SEC(sbi, secno)				\
+	((secno) * (sbi)->segs_per_sec)
+#define GET_ZONE_FROM_SEC(sbi, secno)				\
+	((secno) / (sbi)->secs_per_zone)
+#define GET_ZONE_FROM_SEG(sbi, segno)				\
+	GET_ZONE_FROM_SEC(sbi, GET_SEC_FROM_SEG(sbi, segno))
+
+#define GET_SUM_BLOCK(sbi, segno)				\
+	((sbi)->sm_info->ssa_blkaddr + (segno))
+
+#define GET_SUM_TYPE(footer) ((footer)->entry_type)
+#define SET_SUM_TYPE(footer, type) ((footer)->entry_type = (type))
+
+#define SIT_ENTRY_OFFSET(sit_i, segno)					\
+	((segno) % (sit_i)->sents_per_block)
+#define SIT_BLOCK_OFFSET(segno)					\
+	((segno) / SIT_ENTRY_PER_BLOCK)
+#define	START_SEGNO(segno)		\
+	(SIT_BLOCK_OFFSET(segno) * SIT_ENTRY_PER_BLOCK)
+#define SIT_BLK_CNT(sbi)			\
+	((MAIN_SEGS(sbi) + SIT_ENTRY_PER_BLOCK - 1) / SIT_ENTRY_PER_BLOCK)
+#define f2fs_bitmap_size(nr)			\
+	(BITS_TO_LONGS(nr) * sizeof(unsigned long))
+
+#define SECTOR_FROM_BLOCK(blk_addr)					\
+	(((sector_t)blk_addr) << F2FS_LOG_SECTORS_PER_BLOCK)
+#define SECTOR_TO_BLOCK(sectors)					\
+	((sectors) >> F2FS_LOG_SECTORS_PER_BLOCK)
+
+/*
+ * indicate a block allocation direction: RIGHT and LEFT.
+ * RIGHT means allocating new sections towards the end of volume.
+ * LEFT means the opposite direction.
+ */
+enum {
+	ALLOC_RIGHT = 0,
+	ALLOC_LEFT
+};
+
+/*
+ * In the victim_sel_policy->alloc_mode, there are two block allocation modes.
+ * LFS writes data sequentially with cleaning operations.
+ * SSR (Slack Space Recycle) reuses obsolete space without cleaning operations.
+ */
+enum {
+	LFS = 0,
+	SSR
+};
+
+/*
+ * In the victim_sel_policy->gc_mode, there are two gc, aka cleaning, modes.
+ * GC_CB is based on cost-benefit algorithm.
+ * GC_GREEDY is based on greedy algorithm.
+ */
+enum {
+	GC_CB = 0,
+	GC_GREEDY,
+	ALLOC_NEXT,
+	FLUSH_DEVICE,
+	MAX_GC_POLICY,
+};
+
+/*
+ * BG_GC means the background cleaning job.
+ * FG_GC means the on-demand cleaning job.
+ * FORCE_FG_GC means on-demand cleaning job in background.
+ */
+enum {
+	BG_GC = 0,
+	FG_GC,
+	FORCE_FG_GC,
+};
+
+/* for a function parameter to select a victim segment */
+struct victim_sel_policy {
+	int alloc_mode;			/* LFS or SSR */
+	int gc_mode;			/* GC_CB or GC_GREEDY */
+	unsigned long *dirty_segmap;	/* dirty segment bitmap */
+	unsigned int max_search;	/* maximum # of segments to search */
+	unsigned int offset;		/* last scanned bitmap offset */
+	unsigned int ofs_unit;		/* bitmap search unit */
+	unsigned int min_cost;		/* minimum cost */
+	unsigned int min_segno;		/* segment # having min. cost */
+};
+
+struct seg_entry {
+	unsigned int type:6;		/* segment type like CURSEG_XXX_TYPE */
+	unsigned int valid_blocks:10;	/* # of valid blocks */
+	unsigned int ckpt_valid_blocks:10;	/* # of valid blocks last cp */
+	unsigned int padding:6;		/* padding */
+	unsigned char *cur_valid_map;	/* validity bitmap of blocks */
+#ifdef CONFIG_F2FS_CHECK_FS
+	unsigned char *cur_valid_map_mir;	/* mirror of current valid bitmap */
+#endif
+	/*
+	 * # of valid blocks and the validity bitmap stored in the the last
+	 * checkpoint pack. This information is used by the SSR mode.
+	 */
+	unsigned char *ckpt_valid_map;	/* validity bitmap of blocks last cp */
+	unsigned char *discard_map;
+	unsigned long long mtime;	/* modification time of the segment */
+};
+
+struct sec_entry {
+	unsigned int valid_blocks;	/* # of valid blocks in a section */
+};
+
+struct segment_allocation {
+	void (*allocate_segment)(struct f2fs_sb_info *, int, bool);
+};
+
+/*
+ * this value is set in page as a private data which indicate that
+ * the page is atomically written, and it is in inmem_pages list.
+ */
+#define ATOMIC_WRITTEN_PAGE		((unsigned long)-1)
+#define DUMMY_WRITTEN_PAGE		((unsigned long)-2)
+
+#define IS_ATOMIC_WRITTEN_PAGE(page)			\
+		(page_private(page) == (unsigned long)ATOMIC_WRITTEN_PAGE)
+#define IS_DUMMY_WRITTEN_PAGE(page)			\
+		(page_private(page) == (unsigned long)DUMMY_WRITTEN_PAGE)
+
+struct inmem_pages {
+	struct list_head list;
+	struct page *page;
+	block_t old_addr;		/* for revoking when fail to commit */
+};
+
+struct sit_info {
+	const struct segment_allocation *s_ops;
+
+	block_t sit_base_addr;		/* start block address of SIT area */
+	block_t sit_blocks;		/* # of blocks used by SIT area */
+	block_t written_valid_blocks;	/* # of valid blocks in main area */
+	char *sit_bitmap;		/* SIT bitmap pointer */
+#ifdef CONFIG_F2FS_CHECK_FS
+	char *sit_bitmap_mir;		/* SIT bitmap mirror */
+#endif
+	unsigned int bitmap_size;	/* SIT bitmap size */
+
+	unsigned long *tmp_map;			/* bitmap for temporal use */
+	unsigned long *dirty_sentries_bitmap;	/* bitmap for dirty sentries */
+	unsigned int dirty_sentries;		/* # of dirty sentries */
+	unsigned int sents_per_block;		/* # of SIT entries per block */
+	struct rw_semaphore sentry_lock;	/* to protect SIT cache */
+	struct seg_entry *sentries;		/* SIT segment-level cache */
+	struct sec_entry *sec_entries;		/* SIT section-level cache */
+
+	/* for cost-benefit algorithm in cleaning procedure */
+	unsigned long long elapsed_time;	/* elapsed time after mount */
+	unsigned long long mounted_time;	/* mount time */
+	unsigned long long min_mtime;		/* min. modification time */
+	unsigned long long max_mtime;		/* max. modification time */
+
+	unsigned int last_victim[MAX_GC_POLICY]; /* last victim segment # */
+};
+
+struct free_segmap_info {
+	unsigned int start_segno;	/* start segment number logically */
+	unsigned int free_segments;	/* # of free segments */
+	unsigned int free_sections;	/* # of free sections */
+	spinlock_t segmap_lock;		/* free segmap lock */
+	unsigned long *free_segmap;	/* free segment bitmap */
+	unsigned long *free_secmap;	/* free section bitmap */
+};
+
+/* Notice: The order of dirty type is same with CURSEG_XXX in f2fs.h */
+enum dirty_type {
+	DIRTY_HOT_DATA,		/* dirty segments assigned as hot data logs */
+	DIRTY_WARM_DATA,	/* dirty segments assigned as warm data logs */
+	DIRTY_COLD_DATA,	/* dirty segments assigned as cold data logs */
+	DIRTY_HOT_NODE,		/* dirty segments assigned as hot node logs */
+	DIRTY_WARM_NODE,	/* dirty segments assigned as warm node logs */
+	DIRTY_COLD_NODE,	/* dirty segments assigned as cold node logs */
+	DIRTY,			/* to count # of dirty segments */
+	PRE,			/* to count # of entirely obsolete segments */
+	NR_DIRTY_TYPE
+};
+
+struct dirty_seglist_info {
+	const struct victim_selection *v_ops;	/* victim selction operation */
+	unsigned long *dirty_segmap[NR_DIRTY_TYPE];
+	struct mutex seglist_lock;		/* lock for segment bitmaps */
+	int nr_dirty[NR_DIRTY_TYPE];		/* # of dirty segments */
+	unsigned long *victim_secmap;		/* background GC victims */
+};
+
+/* victim selection function for cleaning and SSR */
+struct victim_selection {
+	int (*get_victim)(struct f2fs_sb_info *, unsigned int *,
+							int, int, char);
+};
+
+/* for active log information */
+struct curseg_info {
+	struct mutex curseg_mutex;		/* lock for consistency */
+	struct f2fs_summary_block *sum_blk;	/* cached summary block */
+	struct rw_semaphore journal_rwsem;	/* protect journal area */
+	struct f2fs_journal *journal;		/* cached journal info */
+	unsigned char alloc_type;		/* current allocation type */
+	unsigned int segno;			/* current segment number */
+	unsigned short next_blkoff;		/* next block offset to write */
+	unsigned int zone;			/* current zone number */
+	unsigned int next_segno;		/* preallocated segment */
+};
+
+struct sit_entry_set {
+	struct list_head set_list;	/* link with all sit sets */
+	unsigned int start_segno;	/* start segno of sits in set */
+	unsigned int entry_cnt;		/* the # of sit entries in set */
+};
+
+/*
+ * inline functions
+ */
+static inline struct curseg_info *CURSEG_I(struct f2fs_sb_info *sbi, int type)
+{
+	return (struct curseg_info *)(SM_I(sbi)->curseg_array + type);
+}
+
+static inline struct seg_entry *get_seg_entry(struct f2fs_sb_info *sbi,
+						unsigned int segno)
+{
+	struct sit_info *sit_i = SIT_I(sbi);
+	return &sit_i->sentries[segno];
+}
+
+static inline struct sec_entry *get_sec_entry(struct f2fs_sb_info *sbi,
+						unsigned int segno)
+{
+	struct sit_info *sit_i = SIT_I(sbi);
+	return &sit_i->sec_entries[GET_SEC_FROM_SEG(sbi, segno)];
+}
+
+static inline unsigned int get_valid_blocks(struct f2fs_sb_info *sbi,
+				unsigned int segno, bool use_section)
+{
+	/*
+	 * In order to get # of valid blocks in a section instantly from many
+	 * segments, f2fs manages two counting structures separately.
+	 */
+	if (use_section && sbi->segs_per_sec > 1)
+		return get_sec_entry(sbi, segno)->valid_blocks;
+	else
+		return get_seg_entry(sbi, segno)->valid_blocks;
+}
+
+static inline void seg_info_from_raw_sit(struct seg_entry *se,
+					struct f2fs_sit_entry *rs)
+{
+	se->valid_blocks = GET_SIT_VBLOCKS(rs);
+	se->ckpt_valid_blocks = GET_SIT_VBLOCKS(rs);
+	memcpy(se->cur_valid_map, rs->valid_map, SIT_VBLOCK_MAP_SIZE);
+	memcpy(se->ckpt_valid_map, rs->valid_map, SIT_VBLOCK_MAP_SIZE);
+#ifdef CONFIG_F2FS_CHECK_FS
+	memcpy(se->cur_valid_map_mir, rs->valid_map, SIT_VBLOCK_MAP_SIZE);
+#endif
+	se->type = GET_SIT_TYPE(rs);
+	se->mtime = le64_to_cpu(rs->mtime);
+}
+
+static inline void __seg_info_to_raw_sit(struct seg_entry *se,
+					struct f2fs_sit_entry *rs)
+{
+	unsigned short raw_vblocks = (se->type << SIT_VBLOCKS_SHIFT) |
+					se->valid_blocks;
+	rs->vblocks = cpu_to_le16(raw_vblocks);
+	memcpy(rs->valid_map, se->cur_valid_map, SIT_VBLOCK_MAP_SIZE);
+	rs->mtime = cpu_to_le64(se->mtime);
+}
+
+static inline void seg_info_to_sit_page(struct f2fs_sb_info *sbi,
+				struct page *page, unsigned int start)
+{
+	struct f2fs_sit_block *raw_sit;
+	struct seg_entry *se;
+	struct f2fs_sit_entry *rs;
+	unsigned int end = min(start + SIT_ENTRY_PER_BLOCK,
+					(unsigned long)MAIN_SEGS(sbi));
+	int i;
+
+	raw_sit = (struct f2fs_sit_block *)page_address(page);
+	for (i = 0; i < end - start; i++) {
+		rs = &raw_sit->entries[i];
+		se = get_seg_entry(sbi, start + i);
+		__seg_info_to_raw_sit(se, rs);
+	}
+}
+
+static inline void seg_info_to_raw_sit(struct seg_entry *se,
+					struct f2fs_sit_entry *rs)
+{
+	__seg_info_to_raw_sit(se, rs);
+
+	memcpy(se->ckpt_valid_map, rs->valid_map, SIT_VBLOCK_MAP_SIZE);
+	se->ckpt_valid_blocks = se->valid_blocks;
+}
+
+static inline unsigned int find_next_inuse(struct free_segmap_info *free_i,
+		unsigned int max, unsigned int segno)
+{
+	unsigned int ret;
+	spin_lock(&free_i->segmap_lock);
+	ret = find_next_bit(free_i->free_segmap, max, segno);
+	spin_unlock(&free_i->segmap_lock);
+	return ret;
+}
+
+static inline void __set_free(struct f2fs_sb_info *sbi, unsigned int segno)
+{
+	struct free_segmap_info *free_i = FREE_I(sbi);
+	unsigned int secno = GET_SEC_FROM_SEG(sbi, segno);
+	unsigned int start_segno = GET_SEG_FROM_SEC(sbi, secno);
+	unsigned int next;
+
+	spin_lock(&free_i->segmap_lock);
+	clear_bit(segno, free_i->free_segmap);
+	free_i->free_segments++;
+
+	next = find_next_bit(free_i->free_segmap,
+			start_segno + sbi->segs_per_sec, start_segno);
+	if (next >= start_segno + sbi->segs_per_sec) {
+		clear_bit(secno, free_i->free_secmap);
+		free_i->free_sections++;
+	}
+	spin_unlock(&free_i->segmap_lock);
+}
+
+static inline void __set_inuse(struct f2fs_sb_info *sbi,
+		unsigned int segno)
+{
+	struct free_segmap_info *free_i = FREE_I(sbi);
+	unsigned int secno = GET_SEC_FROM_SEG(sbi, segno);
+
+	set_bit(segno, free_i->free_segmap);
+	free_i->free_segments--;
+	if (!test_and_set_bit(secno, free_i->free_secmap))
+		free_i->free_sections--;
+}
+
+static inline void __set_test_and_free(struct f2fs_sb_info *sbi,
+		unsigned int segno)
+{
+	struct free_segmap_info *free_i = FREE_I(sbi);
+	unsigned int secno = GET_SEC_FROM_SEG(sbi, segno);
+	unsigned int start_segno = GET_SEG_FROM_SEC(sbi, secno);
+	unsigned int next;
+
+	spin_lock(&free_i->segmap_lock);
+	if (test_and_clear_bit(segno, free_i->free_segmap)) {
+		free_i->free_segments++;
+
+		if (IS_CURSEC(sbi, secno))
+			goto skip_free;
+		next = find_next_bit(free_i->free_segmap,
+				start_segno + sbi->segs_per_sec, start_segno);
+		if (next >= start_segno + sbi->segs_per_sec) {
+			if (test_and_clear_bit(secno, free_i->free_secmap))
+				free_i->free_sections++;
+		}
+	}
+skip_free:
+	spin_unlock(&free_i->segmap_lock);
+}
+
+static inline void __set_test_and_inuse(struct f2fs_sb_info *sbi,
+		unsigned int segno)
+{
+	struct free_segmap_info *free_i = FREE_I(sbi);
+	unsigned int secno = GET_SEC_FROM_SEG(sbi, segno);
+
+	spin_lock(&free_i->segmap_lock);
+	if (!test_and_set_bit(segno, free_i->free_segmap)) {
+		free_i->free_segments--;
+		if (!test_and_set_bit(secno, free_i->free_secmap))
+			free_i->free_sections--;
+	}
+	spin_unlock(&free_i->segmap_lock);
+}
+
+static inline void get_sit_bitmap(struct f2fs_sb_info *sbi,
+		void *dst_addr)
+{
+	struct sit_info *sit_i = SIT_I(sbi);
+
+#ifdef CONFIG_F2FS_CHECK_FS
+	if (memcmp(sit_i->sit_bitmap, sit_i->sit_bitmap_mir,
+						sit_i->bitmap_size))
+		f2fs_bug_on(sbi, 1);
+#endif
+	memcpy(dst_addr, sit_i->sit_bitmap, sit_i->bitmap_size);
+}
+
+static inline block_t written_block_count(struct f2fs_sb_info *sbi)
+{
+	return SIT_I(sbi)->written_valid_blocks;
+}
+
+static inline unsigned int free_segments(struct f2fs_sb_info *sbi)
+{
+	return FREE_I(sbi)->free_segments;
+}
+
+static inline int reserved_segments(struct f2fs_sb_info *sbi)
+{
+	return SM_I(sbi)->reserved_segments;
+}
+
+static inline unsigned int free_sections(struct f2fs_sb_info *sbi)
+{
+	return FREE_I(sbi)->free_sections;
+}
+
+static inline unsigned int prefree_segments(struct f2fs_sb_info *sbi)
+{
+	return DIRTY_I(sbi)->nr_dirty[PRE];
+}
+
+static inline unsigned int dirty_segments(struct f2fs_sb_info *sbi)
+{
+	return DIRTY_I(sbi)->nr_dirty[DIRTY_HOT_DATA] +
+		DIRTY_I(sbi)->nr_dirty[DIRTY_WARM_DATA] +
+		DIRTY_I(sbi)->nr_dirty[DIRTY_COLD_DATA] +
+		DIRTY_I(sbi)->nr_dirty[DIRTY_HOT_NODE] +
+		DIRTY_I(sbi)->nr_dirty[DIRTY_WARM_NODE] +
+		DIRTY_I(sbi)->nr_dirty[DIRTY_COLD_NODE];
+}
+
+static inline int overprovision_segments(struct f2fs_sb_info *sbi)
+{
+	return SM_I(sbi)->ovp_segments;
+}
+
+static inline int reserved_sections(struct f2fs_sb_info *sbi)
+{
+	return GET_SEC_FROM_SEG(sbi, (unsigned int)reserved_segments(sbi));
+}
+
+static inline bool has_curseg_enough_space(struct f2fs_sb_info *sbi)
+{
+	unsigned int node_blocks = get_pages(sbi, F2FS_DIRTY_NODES) +
+					get_pages(sbi, F2FS_DIRTY_DENTS);
+	unsigned int dent_blocks = get_pages(sbi, F2FS_DIRTY_DENTS);
+	unsigned int segno, left_blocks;
+	int i;
+
+	/* check current node segment */
+	for (i = CURSEG_HOT_NODE; i <= CURSEG_COLD_NODE; i++) {
+		segno = CURSEG_I(sbi, i)->segno;
+		left_blocks = sbi->blocks_per_seg -
+			get_seg_entry(sbi, segno)->ckpt_valid_blocks;
+
+		if (node_blocks > left_blocks)
+			return false;
+	}
+
+	/* check current data segment */
+	segno = CURSEG_I(sbi, CURSEG_HOT_DATA)->segno;
+	left_blocks = sbi->blocks_per_seg -
+			get_seg_entry(sbi, segno)->ckpt_valid_blocks;
+	if (dent_blocks > left_blocks)
+		return false;
+	return true;
+}
+
+static inline bool has_not_enough_free_secs(struct f2fs_sb_info *sbi,
+					int freed, int needed)
+{
+	int node_secs = get_blocktype_secs(sbi, F2FS_DIRTY_NODES);
+	int dent_secs = get_blocktype_secs(sbi, F2FS_DIRTY_DENTS);
+	int imeta_secs = get_blocktype_secs(sbi, F2FS_DIRTY_IMETA);
+
+	if (unlikely(is_sbi_flag_set(sbi, SBI_POR_DOING)))
+		return false;
+
+	if (free_sections(sbi) + freed == reserved_sections(sbi) + needed &&
+			has_curseg_enough_space(sbi))
+		return false;
+	return (free_sections(sbi) + freed) <=
+		(node_secs + 2 * dent_secs + imeta_secs +
+		reserved_sections(sbi) + needed);
+}
+
+static inline bool excess_prefree_segs(struct f2fs_sb_info *sbi)
+{
+	return prefree_segments(sbi) > SM_I(sbi)->rec_prefree_segments;
+}
+
+static inline int utilization(struct f2fs_sb_info *sbi)
+{
+	return div_u64((u64)valid_user_blocks(sbi) * 100,
+					sbi->user_block_count);
+}
+
+/*
+ * Sometimes f2fs may be better to drop out-of-place update policy.
+ * And, users can control the policy through sysfs entries.
+ * There are five policies with triggering conditions as follows.
+ * F2FS_IPU_FORCE - all the time,
+ * F2FS_IPU_SSR - if SSR mode is activated,
+ * F2FS_IPU_UTIL - if FS utilization is over threashold,
+ * F2FS_IPU_SSR_UTIL - if SSR mode is activated and FS utilization is over
+ *                     threashold,
+ * F2FS_IPU_FSYNC - activated in fsync path only for high performance flash
+ *                     storages. IPU will be triggered only if the # of dirty
+ *                     pages over min_fsync_blocks.
+ * F2FS_IPUT_DISABLE - disable IPU. (=default option)
+ */
+#define DEF_MIN_IPU_UTIL	70
+#define DEF_MIN_FSYNC_BLOCKS	8
+#define DEF_MIN_HOT_BLOCKS	16
+
+#define SMALL_VOLUME_SEGMENTS	(16 * 512)	/* 16GB */
+
+enum {
+	F2FS_IPU_FORCE,
+	F2FS_IPU_SSR,
+	F2FS_IPU_UTIL,
+	F2FS_IPU_SSR_UTIL,
+	F2FS_IPU_FSYNC,
+	F2FS_IPU_ASYNC,
+};
+
+static inline unsigned int curseg_segno(struct f2fs_sb_info *sbi,
+		int type)
+{
+	struct curseg_info *curseg = CURSEG_I(sbi, type);
+	return curseg->segno;
+}
+
+static inline unsigned char curseg_alloc_type(struct f2fs_sb_info *sbi,
+		int type)
+{
+	struct curseg_info *curseg = CURSEG_I(sbi, type);
+	return curseg->alloc_type;
+}
+
+static inline unsigned short curseg_blkoff(struct f2fs_sb_info *sbi, int type)
+{
+	struct curseg_info *curseg = CURSEG_I(sbi, type);
+	return curseg->next_blkoff;
+}
+
+static inline void check_seg_range(struct f2fs_sb_info *sbi, unsigned int segno)
+{
+	f2fs_bug_on(sbi, segno > TOTAL_SEGS(sbi) - 1);
+}
+
+static inline void verify_block_addr(struct f2fs_io_info *fio, block_t blk_addr)
+{
+	struct f2fs_sb_info *sbi = fio->sbi;
+
+	if (__is_meta_io(fio))
+		verify_blkaddr(sbi, blk_addr, META_GENERIC);
+	else
+		verify_blkaddr(sbi, blk_addr, DATA_GENERIC);
+}
+
+/*
+ * Summary block is always treated as an invalid block
+ */
+static inline int check_block_count(struct f2fs_sb_info *sbi,
+		int segno, struct f2fs_sit_entry *raw_sit)
+{
+	bool is_valid  = test_bit_le(0, raw_sit->valid_map) ? true : false;
+	int valid_blocks = 0;
+	int cur_pos = 0, next_pos;
+
+	/* check bitmap with valid block count */
+	do {
+		if (is_valid) {
+			next_pos = find_next_zero_bit_le(&raw_sit->valid_map,
+					sbi->blocks_per_seg,
+					cur_pos);
+			valid_blocks += next_pos - cur_pos;
+		} else
+			next_pos = find_next_bit_le(&raw_sit->valid_map,
+					sbi->blocks_per_seg,
+					cur_pos);
+		cur_pos = next_pos;
+		is_valid = !is_valid;
+	} while (cur_pos < sbi->blocks_per_seg);
+
+	if (unlikely(GET_SIT_VBLOCKS(raw_sit) != valid_blocks)) {
+		f2fs_msg(sbi->sb, KERN_ERR,
+				"Mismatch valid blocks %d vs. %d",
+					GET_SIT_VBLOCKS(raw_sit), valid_blocks);
+		set_sbi_flag(sbi, SBI_NEED_FSCK);
+		return -EFSCORRUPTED;
+	}
+
+	/* check segment usage, and check boundary of a given segment number */
+	if (unlikely(GET_SIT_VBLOCKS(raw_sit) > sbi->blocks_per_seg
+					|| segno > TOTAL_SEGS(sbi) - 1)) {
+		f2fs_msg(sbi->sb, KERN_ERR,
+				"Wrong valid blocks %d or segno %u",
+					GET_SIT_VBLOCKS(raw_sit), segno);
+		set_sbi_flag(sbi, SBI_NEED_FSCK);
+		return -EFSCORRUPTED;
+	}
+	return 0;
+}
+
+static inline pgoff_t current_sit_addr(struct f2fs_sb_info *sbi,
+						unsigned int start)
+{
+	struct sit_info *sit_i = SIT_I(sbi);
+	unsigned int offset = SIT_BLOCK_OFFSET(start);
+	block_t blk_addr = sit_i->sit_base_addr + offset;
+
+	check_seg_range(sbi, start);
+
+#ifdef CONFIG_F2FS_CHECK_FS
+	if (f2fs_test_bit(offset, sit_i->sit_bitmap) !=
+			f2fs_test_bit(offset, sit_i->sit_bitmap_mir))
+		f2fs_bug_on(sbi, 1);
+#endif
+
+	/* calculate sit block address */
+	if (f2fs_test_bit(offset, sit_i->sit_bitmap))
+		blk_addr += sit_i->sit_blocks;
+
+	return blk_addr;
+}
+
+static inline pgoff_t next_sit_addr(struct f2fs_sb_info *sbi,
+						pgoff_t block_addr)
+{
+	struct sit_info *sit_i = SIT_I(sbi);
+	block_addr -= sit_i->sit_base_addr;
+	if (block_addr < sit_i->sit_blocks)
+		block_addr += sit_i->sit_blocks;
+	else
+		block_addr -= sit_i->sit_blocks;
+
+	return block_addr + sit_i->sit_base_addr;
+}
+
+static inline void set_to_next_sit(struct sit_info *sit_i, unsigned int start)
+{
+	unsigned int block_off = SIT_BLOCK_OFFSET(start);
+
+	f2fs_change_bit(block_off, sit_i->sit_bitmap);
+#ifdef CONFIG_F2FS_CHECK_FS
+	f2fs_change_bit(block_off, sit_i->sit_bitmap_mir);
+#endif
+}
+
+static inline unsigned long long get_mtime(struct f2fs_sb_info *sbi)
+{
+	struct sit_info *sit_i = SIT_I(sbi);
+	time64_t now = ktime_get_real_seconds();
+
+	return sit_i->elapsed_time + now - sit_i->mounted_time;
+}
+
+static inline void set_summary(struct f2fs_summary *sum, nid_t nid,
+			unsigned int ofs_in_node, unsigned char version)
+{
+	sum->nid = cpu_to_le32(nid);
+	sum->ofs_in_node = cpu_to_le16(ofs_in_node);
+	sum->version = version;
+}
+
+static inline block_t start_sum_block(struct f2fs_sb_info *sbi)
+{
+	return __start_cp_addr(sbi) +
+		le32_to_cpu(F2FS_CKPT(sbi)->cp_pack_start_sum);
+}
+
+static inline block_t sum_blk_addr(struct f2fs_sb_info *sbi, int base, int type)
+{
+	return __start_cp_addr(sbi) +
+		le32_to_cpu(F2FS_CKPT(sbi)->cp_pack_total_block_count)
+				- (base + 1) + type;
+}
+
+static inline bool no_fggc_candidate(struct f2fs_sb_info *sbi,
+						unsigned int secno)
+{
+	if (get_valid_blocks(sbi, GET_SEG_FROM_SEC(sbi, secno), true) >
+						sbi->fggc_threshold)
+		return true;
+	return false;
+}
+
+static inline bool sec_usage_check(struct f2fs_sb_info *sbi, unsigned int secno)
+{
+	if (IS_CURSEC(sbi, secno) || (sbi->cur_victim_sec == secno))
+		return true;
+	return false;
+}
+
+/*
+ * It is very important to gather dirty pages and write at once, so that we can
+ * submit a big bio without interfering other data writes.
+ * By default, 512 pages for directory data,
+ * 512 pages (2MB) * 8 for nodes, and
+ * 256 pages * 8 for meta are set.
+ */
+static inline int nr_pages_to_skip(struct f2fs_sb_info *sbi, int type)
+{
+	if (sbi->sb->s_bdi->wb.dirty_exceeded)
+		return 0;
+
+	if (type == DATA)
+		return sbi->blocks_per_seg;
+	else if (type == NODE)
+		return 8 * sbi->blocks_per_seg;
+	else if (type == META)
+		return 8 * BIO_MAX_PAGES;
+	else
+		return 0;
+}
+
+/*
+ * When writing pages, it'd better align nr_to_write for segment size.
+ */
+static inline long nr_pages_to_write(struct f2fs_sb_info *sbi, int type,
+					struct writeback_control *wbc)
+{
+	long nr_to_write, desired;
+
+	if (wbc->sync_mode != WB_SYNC_NONE)
+		return 0;
+
+	nr_to_write = wbc->nr_to_write;
+	desired = BIO_MAX_PAGES;
+	if (type == NODE)
+		desired <<= 1;
+
+	wbc->nr_to_write = desired;
+	return desired - nr_to_write;
+}
+
+static inline void wake_up_discard_thread(struct f2fs_sb_info *sbi, bool force)
+{
+	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
+	bool wakeup = false;
+	int i;
+
+	if (force)
+		goto wake_up;
+
+	mutex_lock(&dcc->cmd_lock);
+	for (i = MAX_PLIST_NUM - 1; i >= 0; i--) {
+		if (i + 1 < dcc->discard_granularity)
+			break;
+		if (!list_empty(&dcc->pend_list[i])) {
+			wakeup = true;
+			break;
+		}
+	}
+	mutex_unlock(&dcc->cmd_lock);
+	if (!wakeup)
+		return;
+wake_up:
+	dcc->discard_wake = 1;
+	wake_up_interruptible_all(&dcc->discard_wait_queue);
+}
diff --git a/src/kernel/linux/v4.14/fs/f2fs/shrinker.c b/src/kernel/linux/v4.14/fs/f2fs/shrinker.c
new file mode 100644
index 0000000..0030bed
--- /dev/null
+++ b/src/kernel/linux/v4.14/fs/f2fs/shrinker.c
@@ -0,0 +1,143 @@
+/*
+ * f2fs shrinker support
+ *   the basic infra was copied from fs/ubifs/shrinker.c
+ *
+ * Copyright (c) 2015 Motorola Mobility
+ * Copyright (c) 2015 Jaegeuk Kim <jaegeuk@kernel.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/fs.h>
+#include <linux/f2fs_fs.h>
+
+#include "f2fs.h"
+#include "node.h"
+
+static LIST_HEAD(f2fs_list);
+static DEFINE_SPINLOCK(f2fs_list_lock);
+static unsigned int shrinker_run_no;
+
+static unsigned long __count_nat_entries(struct f2fs_sb_info *sbi)
+{
+	long count = NM_I(sbi)->nat_cnt - NM_I(sbi)->dirty_nat_cnt;
+
+	return count > 0 ? count : 0;
+}
+
+static unsigned long __count_free_nids(struct f2fs_sb_info *sbi)
+{
+	long count = NM_I(sbi)->nid_cnt[FREE_NID] - MAX_FREE_NIDS;
+
+	return count > 0 ? count : 0;
+}
+
+static unsigned long __count_extent_cache(struct f2fs_sb_info *sbi)
+{
+	return atomic_read(&sbi->total_zombie_tree) +
+				atomic_read(&sbi->total_ext_node);
+}
+
+unsigned long f2fs_shrink_count(struct shrinker *shrink,
+				struct shrink_control *sc)
+{
+	struct f2fs_sb_info *sbi;
+	struct list_head *p;
+	unsigned long count = 0;
+
+	spin_lock(&f2fs_list_lock);
+	p = f2fs_list.next;
+	while (p != &f2fs_list) {
+		sbi = list_entry(p, struct f2fs_sb_info, s_list);
+
+		/* stop f2fs_put_super */
+		if (!mutex_trylock(&sbi->umount_mutex)) {
+			p = p->next;
+			continue;
+		}
+		spin_unlock(&f2fs_list_lock);
+
+		/* count extent cache entries */
+		count += __count_extent_cache(sbi);
+
+		/* shrink clean nat cache entries */
+		count += __count_nat_entries(sbi);
+
+		/* count free nids cache entries */
+		count += __count_free_nids(sbi);
+
+		spin_lock(&f2fs_list_lock);
+		p = p->next;
+		mutex_unlock(&sbi->umount_mutex);
+	}
+	spin_unlock(&f2fs_list_lock);
+	return count;
+}
+
+unsigned long f2fs_shrink_scan(struct shrinker *shrink,
+				struct shrink_control *sc)
+{
+	unsigned long nr = sc->nr_to_scan;
+	struct f2fs_sb_info *sbi;
+	struct list_head *p;
+	unsigned int run_no;
+	unsigned long freed = 0;
+
+	spin_lock(&f2fs_list_lock);
+	do {
+		run_no = ++shrinker_run_no;
+	} while (run_no == 0);
+	p = f2fs_list.next;
+	while (p != &f2fs_list) {
+		sbi = list_entry(p, struct f2fs_sb_info, s_list);
+
+		if (sbi->shrinker_run_no == run_no)
+			break;
+
+		/* stop f2fs_put_super */
+		if (!mutex_trylock(&sbi->umount_mutex)) {
+			p = p->next;
+			continue;
+		}
+		spin_unlock(&f2fs_list_lock);
+
+		sbi->shrinker_run_no = run_no;
+
+		/* shrink extent cache entries */
+		freed += f2fs_shrink_extent_tree(sbi, nr >> 1);
+
+		/* shrink clean nat cache entries */
+		if (freed < nr)
+			freed += try_to_free_nats(sbi, nr - freed);
+
+		/* shrink free nids cache entries */
+		if (freed < nr)
+			freed += try_to_free_nids(sbi, nr - freed);
+
+		spin_lock(&f2fs_list_lock);
+		p = p->next;
+		list_move_tail(&sbi->s_list, &f2fs_list);
+		mutex_unlock(&sbi->umount_mutex);
+		if (freed >= nr)
+			break;
+	}
+	spin_unlock(&f2fs_list_lock);
+	return freed;
+}
+
+void f2fs_join_shrinker(struct f2fs_sb_info *sbi)
+{
+	spin_lock(&f2fs_list_lock);
+	list_add_tail(&sbi->s_list, &f2fs_list);
+	spin_unlock(&f2fs_list_lock);
+}
+
+void f2fs_leave_shrinker(struct f2fs_sb_info *sbi)
+{
+	f2fs_shrink_extent_tree(sbi, __count_extent_cache(sbi));
+
+	spin_lock(&f2fs_list_lock);
+	list_del_init(&sbi->s_list);
+	spin_unlock(&f2fs_list_lock);
+}
diff --git a/src/kernel/linux/v4.14/fs/f2fs/super.c b/src/kernel/linux/v4.14/fs/f2fs/super.c
new file mode 100644
index 0000000..171120d
--- /dev/null
+++ b/src/kernel/linux/v4.14/fs/f2fs/super.c
@@ -0,0 +1,3309 @@
+/*
+ * fs/f2fs/super.c
+ *
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ *             http://www.samsung.com/
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/fs.h>
+#include <linux/statfs.h>
+#include <linux/buffer_head.h>
+#include <linux/backing-dev.h>
+#include <linux/kthread.h>
+#include <linux/parser.h>
+#include <linux/mount.h>
+#include <linux/seq_file.h>
+#include <linux/proc_fs.h>
+#include <linux/random.h>
+#include <linux/exportfs.h>
+#include <linux/blkdev.h>
+#include <linux/quotaops.h>
+#include <linux/f2fs_fs.h>
+#include <linux/sysfs.h>
+#include <linux/quota.h>
+
+#include "f2fs.h"
+#include "node.h"
+#include "segment.h"
+#include "xattr.h"
+#include "gc.h"
+#include "trace.h"
+
+#define CREATE_TRACE_POINTS
+#include <trace/events/f2fs.h>
+
+static struct kmem_cache *f2fs_inode_cachep;
+
+#ifdef CONFIG_F2FS_FAULT_INJECTION
+
+char *fault_name[FAULT_MAX] = {
+	[FAULT_KMALLOC]		= "kmalloc",
+	[FAULT_KVMALLOC]	= "kvmalloc",
+	[FAULT_PAGE_ALLOC]	= "page alloc",
+	[FAULT_PAGE_GET]	= "page get",
+	[FAULT_ALLOC_BIO]	= "alloc bio",
+	[FAULT_ALLOC_NID]	= "alloc nid",
+	[FAULT_ORPHAN]		= "orphan",
+	[FAULT_BLOCK]		= "no more block",
+	[FAULT_DIR_DEPTH]	= "too big dir depth",
+	[FAULT_EVICT_INODE]	= "evict_inode fail",
+	[FAULT_TRUNCATE]	= "truncate fail",
+	[FAULT_IO]		= "IO error",
+	[FAULT_CHECKPOINT]	= "checkpoint error",
+};
+
+static void f2fs_build_fault_attr(struct f2fs_sb_info *sbi,
+						unsigned int rate)
+{
+	struct f2fs_fault_info *ffi = &F2FS_OPTION(sbi).fault_info;
+
+	if (rate) {
+		atomic_set(&ffi->inject_ops, 0);
+		ffi->inject_rate = rate;
+		ffi->inject_type = (1 << FAULT_MAX) - 1;
+	} else {
+		memset(ffi, 0, sizeof(struct f2fs_fault_info));
+	}
+}
+#endif
+
+/* f2fs-wide shrinker description */
+static struct shrinker f2fs_shrinker_info = {
+	.scan_objects = f2fs_shrink_scan,
+	.count_objects = f2fs_shrink_count,
+	.seeks = DEFAULT_SEEKS,
+};
+
+enum {
+	Opt_gc_background,
+	Opt_disable_roll_forward,
+	Opt_norecovery,
+	Opt_discard,
+	Opt_nodiscard,
+	Opt_noheap,
+	Opt_heap,
+	Opt_user_xattr,
+	Opt_nouser_xattr,
+	Opt_acl,
+	Opt_noacl,
+	Opt_active_logs,
+	Opt_disable_ext_identify,
+	Opt_inline_xattr,
+	Opt_noinline_xattr,
+	Opt_inline_xattr_size,
+	Opt_inline_data,
+	Opt_inline_dentry,
+	Opt_noinline_dentry,
+	Opt_flush_merge,
+	Opt_noflush_merge,
+	Opt_nobarrier,
+	Opt_fastboot,
+	Opt_extent_cache,
+	Opt_noextent_cache,
+	Opt_noinline_data,
+	Opt_data_flush,
+	Opt_reserve_root,
+	Opt_resgid,
+	Opt_resuid,
+	Opt_mode,
+	Opt_io_size_bits,
+	Opt_fault_injection,
+	Opt_lazytime,
+	Opt_nolazytime,
+	Opt_quota,
+	Opt_noquota,
+	Opt_usrquota,
+	Opt_grpquota,
+	Opt_prjquota,
+	Opt_usrjquota,
+	Opt_grpjquota,
+	Opt_prjjquota,
+	Opt_offusrjquota,
+	Opt_offgrpjquota,
+	Opt_offprjjquota,
+	Opt_jqfmt_vfsold,
+	Opt_jqfmt_vfsv0,
+	Opt_jqfmt_vfsv1,
+	Opt_whint,
+	Opt_alloc,
+	Opt_fsync,
+	Opt_test_dummy_encryption,
+	Opt_err,
+};
+
+static match_table_t f2fs_tokens = {
+	{Opt_gc_background, "background_gc=%s"},
+	{Opt_disable_roll_forward, "disable_roll_forward"},
+	{Opt_norecovery, "norecovery"},
+	{Opt_discard, "discard"},
+	{Opt_nodiscard, "nodiscard"},
+	{Opt_noheap, "no_heap"},
+	{Opt_heap, "heap"},
+	{Opt_user_xattr, "user_xattr"},
+	{Opt_nouser_xattr, "nouser_xattr"},
+	{Opt_acl, "acl"},
+	{Opt_noacl, "noacl"},
+	{Opt_active_logs, "active_logs=%u"},
+	{Opt_disable_ext_identify, "disable_ext_identify"},
+	{Opt_inline_xattr, "inline_xattr"},
+	{Opt_noinline_xattr, "noinline_xattr"},
+	{Opt_inline_xattr_size, "inline_xattr_size=%u"},
+	{Opt_inline_data, "inline_data"},
+	{Opt_inline_dentry, "inline_dentry"},
+	{Opt_noinline_dentry, "noinline_dentry"},
+	{Opt_flush_merge, "flush_merge"},
+	{Opt_noflush_merge, "noflush_merge"},
+	{Opt_nobarrier, "nobarrier"},
+	{Opt_fastboot, "fastboot"},
+	{Opt_extent_cache, "extent_cache"},
+	{Opt_noextent_cache, "noextent_cache"},
+	{Opt_noinline_data, "noinline_data"},
+	{Opt_data_flush, "data_flush"},
+	{Opt_reserve_root, "reserve_root=%u"},
+	{Opt_resgid, "resgid=%u"},
+	{Opt_resuid, "resuid=%u"},
+	{Opt_mode, "mode=%s"},
+	{Opt_io_size_bits, "io_bits=%u"},
+	{Opt_fault_injection, "fault_injection=%u"},
+	{Opt_lazytime, "lazytime"},
+	{Opt_nolazytime, "nolazytime"},
+	{Opt_quota, "quota"},
+	{Opt_noquota, "noquota"},
+	{Opt_usrquota, "usrquota"},
+	{Opt_grpquota, "grpquota"},
+	{Opt_prjquota, "prjquota"},
+	{Opt_usrjquota, "usrjquota=%s"},
+	{Opt_grpjquota, "grpjquota=%s"},
+	{Opt_prjjquota, "prjjquota=%s"},
+	{Opt_offusrjquota, "usrjquota="},
+	{Opt_offgrpjquota, "grpjquota="},
+	{Opt_offprjjquota, "prjjquota="},
+	{Opt_jqfmt_vfsold, "jqfmt=vfsold"},
+	{Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
+	{Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
+	{Opt_whint, "whint_mode=%s"},
+	{Opt_alloc, "alloc_mode=%s"},
+	{Opt_fsync, "fsync_mode=%s"},
+	{Opt_test_dummy_encryption, "test_dummy_encryption"},
+	{Opt_err, NULL},
+};
+
+void f2fs_msg(struct super_block *sb, const char *level, const char *fmt, ...)
+{
+	struct va_format vaf;
+	va_list args;
+
+	va_start(args, fmt);
+	vaf.fmt = fmt;
+	vaf.va = &args;
+	printk_ratelimited("%sF2FS-fs (%s): %pV\n", level, sb->s_id, &vaf);
+	va_end(args);
+}
+
+static inline void limit_reserve_root(struct f2fs_sb_info *sbi)
+{
+	block_t limit = (sbi->user_block_count << 1) / 1000;
+
+	/* limit is 0.2% */
+	if (test_opt(sbi, RESERVE_ROOT) &&
+			F2FS_OPTION(sbi).root_reserved_blocks > limit) {
+		F2FS_OPTION(sbi).root_reserved_blocks = limit;
+		f2fs_msg(sbi->sb, KERN_INFO,
+			"Reduce reserved blocks for root = %u",
+			F2FS_OPTION(sbi).root_reserved_blocks);
+	}
+	if (!test_opt(sbi, RESERVE_ROOT) &&
+		(!uid_eq(F2FS_OPTION(sbi).s_resuid,
+				make_kuid(&init_user_ns, F2FS_DEF_RESUID)) ||
+		!gid_eq(F2FS_OPTION(sbi).s_resgid,
+				make_kgid(&init_user_ns, F2FS_DEF_RESGID))))
+		f2fs_msg(sbi->sb, KERN_INFO,
+			"Ignore s_resuid=%u, s_resgid=%u w/o reserve_root",
+				from_kuid_munged(&init_user_ns,
+					F2FS_OPTION(sbi).s_resuid),
+				from_kgid_munged(&init_user_ns,
+					F2FS_OPTION(sbi).s_resgid));
+}
+
+static void init_once(void *foo)
+{
+	struct f2fs_inode_info *fi = (struct f2fs_inode_info *) foo;
+
+	inode_init_once(&fi->vfs_inode);
+}
+
+#ifdef CONFIG_QUOTA
+static const char * const quotatypes[] = INITQFNAMES;
+#define QTYPE2NAME(t) (quotatypes[t])
+static int f2fs_set_qf_name(struct super_block *sb, int qtype,
+							substring_t *args)
+{
+	struct f2fs_sb_info *sbi = F2FS_SB(sb);
+	char *qname;
+	int ret = -EINVAL;
+
+	if (sb_any_quota_loaded(sb) && !F2FS_OPTION(sbi).s_qf_names[qtype]) {
+		f2fs_msg(sb, KERN_ERR,
+			"Cannot change journaled "
+			"quota options when quota turned on");
+		return -EINVAL;
+	}
+	if (f2fs_sb_has_quota_ino(sb)) {
+		f2fs_msg(sb, KERN_INFO,
+			"QUOTA feature is enabled, so ignore qf_name");
+		return 0;
+	}
+
+	qname = match_strdup(args);
+	if (!qname) {
+		f2fs_msg(sb, KERN_ERR,
+			"Not enough memory for storing quotafile name");
+		return -EINVAL;
+	}
+	if (F2FS_OPTION(sbi).s_qf_names[qtype]) {
+		if (strcmp(F2FS_OPTION(sbi).s_qf_names[qtype], qname) == 0)
+			ret = 0;
+		else
+			f2fs_msg(sb, KERN_ERR,
+				 "%s quota file already specified",
+				 QTYPE2NAME(qtype));
+		goto errout;
+	}
+	if (strchr(qname, '/')) {
+		f2fs_msg(sb, KERN_ERR,
+			"quotafile must be on filesystem root");
+		goto errout;
+	}
+	F2FS_OPTION(sbi).s_qf_names[qtype] = qname;
+	set_opt(sbi, QUOTA);
+	return 0;
+errout:
+	kfree(qname);
+	return ret;
+}
+
+static int f2fs_clear_qf_name(struct super_block *sb, int qtype)
+{
+	struct f2fs_sb_info *sbi = F2FS_SB(sb);
+
+	if (sb_any_quota_loaded(sb) && F2FS_OPTION(sbi).s_qf_names[qtype]) {
+		f2fs_msg(sb, KERN_ERR, "Cannot change journaled quota options"
+			" when quota turned on");
+		return -EINVAL;
+	}
+	kfree(F2FS_OPTION(sbi).s_qf_names[qtype]);
+	F2FS_OPTION(sbi).s_qf_names[qtype] = NULL;
+	return 0;
+}
+
+static int f2fs_check_quota_options(struct f2fs_sb_info *sbi)
+{
+	/*
+	 * We do the test below only for project quotas. 'usrquota' and
+	 * 'grpquota' mount options are allowed even without quota feature
+	 * to support legacy quotas in quota files.
+	 */
+	if (test_opt(sbi, PRJQUOTA) && !f2fs_sb_has_project_quota(sbi->sb)) {
+		f2fs_msg(sbi->sb, KERN_ERR, "Project quota feature not enabled. "
+			 "Cannot enable project quota enforcement.");
+		return -1;
+	}
+	if (F2FS_OPTION(sbi).s_qf_names[USRQUOTA] ||
+			F2FS_OPTION(sbi).s_qf_names[GRPQUOTA] ||
+			F2FS_OPTION(sbi).s_qf_names[PRJQUOTA]) {
+		if (test_opt(sbi, USRQUOTA) &&
+				F2FS_OPTION(sbi).s_qf_names[USRQUOTA])
+			clear_opt(sbi, USRQUOTA);
+
+		if (test_opt(sbi, GRPQUOTA) &&
+				F2FS_OPTION(sbi).s_qf_names[GRPQUOTA])
+			clear_opt(sbi, GRPQUOTA);
+
+		if (test_opt(sbi, PRJQUOTA) &&
+				F2FS_OPTION(sbi).s_qf_names[PRJQUOTA])
+			clear_opt(sbi, PRJQUOTA);
+
+		if (test_opt(sbi, GRPQUOTA) || test_opt(sbi, USRQUOTA) ||
+				test_opt(sbi, PRJQUOTA)) {
+			f2fs_msg(sbi->sb, KERN_ERR, "old and new quota "
+					"format mixing");
+			return -1;
+		}
+
+		if (!F2FS_OPTION(sbi).s_jquota_fmt) {
+			f2fs_msg(sbi->sb, KERN_ERR, "journaled quota format "
+					"not specified");
+			return -1;
+		}
+	}
+
+	if (f2fs_sb_has_quota_ino(sbi->sb) && F2FS_OPTION(sbi).s_jquota_fmt) {
+		f2fs_msg(sbi->sb, KERN_INFO,
+			"QUOTA feature is enabled, so ignore jquota_fmt");
+		F2FS_OPTION(sbi).s_jquota_fmt = 0;
+	}
+	if (f2fs_sb_has_quota_ino(sbi->sb) && f2fs_readonly(sbi->sb)) {
+		f2fs_msg(sbi->sb, KERN_INFO,
+			 "Filesystem with quota feature cannot be mounted RDWR "
+			 "without CONFIG_QUOTA");
+		return -1;
+	}
+	return 0;
+}
+#endif
+
+static int parse_options(struct super_block *sb, char *options)
+{
+	struct f2fs_sb_info *sbi = F2FS_SB(sb);
+	struct request_queue *q;
+	substring_t args[MAX_OPT_ARGS];
+	char *p, *name;
+	int arg = 0;
+	kuid_t uid;
+	kgid_t gid;
+#ifdef CONFIG_QUOTA
+	int ret;
+#endif
+
+	if (!options)
+		return 0;
+
+	while ((p = strsep(&options, ",")) != NULL) {
+		int token;
+		if (!*p)
+			continue;
+		/*
+		 * Initialize args struct so we know whether arg was
+		 * found; some options take optional arguments.
+		 */
+		args[0].to = args[0].from = NULL;
+		token = match_token(p, f2fs_tokens, args);
+
+		switch (token) {
+		case Opt_gc_background:
+			name = match_strdup(&args[0]);
+
+			if (!name)
+				return -ENOMEM;
+			if (strlen(name) == 2 && !strncmp(name, "on", 2)) {
+				set_opt(sbi, BG_GC);
+				clear_opt(sbi, FORCE_FG_GC);
+			} else if (strlen(name) == 3 && !strncmp(name, "off", 3)) {
+				clear_opt(sbi, BG_GC);
+				clear_opt(sbi, FORCE_FG_GC);
+			} else if (strlen(name) == 4 && !strncmp(name, "sync", 4)) {
+				set_opt(sbi, BG_GC);
+				set_opt(sbi, FORCE_FG_GC);
+			} else {
+				kfree(name);
+				return -EINVAL;
+			}
+			kfree(name);
+			break;
+		case Opt_disable_roll_forward:
+			set_opt(sbi, DISABLE_ROLL_FORWARD);
+			break;
+		case Opt_norecovery:
+			/* this option mounts f2fs with ro */
+			set_opt(sbi, DISABLE_ROLL_FORWARD);
+			if (!f2fs_readonly(sb))
+				return -EINVAL;
+			break;
+		case Opt_discard:
+			q = bdev_get_queue(sb->s_bdev);
+			if (blk_queue_discard(q)) {
+				set_opt(sbi, DISCARD);
+			} else if (!f2fs_sb_has_blkzoned(sb)) {
+				f2fs_msg(sb, KERN_WARNING,
+					"mounting with \"discard\" option, but "
+					"the device does not support discard");
+			}
+			break;
+		case Opt_nodiscard:
+			if (f2fs_sb_has_blkzoned(sb)) {
+				f2fs_msg(sb, KERN_WARNING,
+					"discard is required for zoned block devices");
+				return -EINVAL;
+			}
+			clear_opt(sbi, DISCARD);
+			break;
+		case Opt_noheap:
+			set_opt(sbi, NOHEAP);
+			break;
+		case Opt_heap:
+			clear_opt(sbi, NOHEAP);
+			break;
+#ifdef CONFIG_F2FS_FS_XATTR
+		case Opt_user_xattr:
+			set_opt(sbi, XATTR_USER);
+			break;
+		case Opt_nouser_xattr:
+			clear_opt(sbi, XATTR_USER);
+			break;
+		case Opt_inline_xattr:
+			set_opt(sbi, INLINE_XATTR);
+			break;
+		case Opt_noinline_xattr:
+			clear_opt(sbi, INLINE_XATTR);
+			break;
+		case Opt_inline_xattr_size:
+			if (args->from && match_int(args, &arg))
+				return -EINVAL;
+			set_opt(sbi, INLINE_XATTR_SIZE);
+			F2FS_OPTION(sbi).inline_xattr_size = arg;
+			break;
+#else
+		case Opt_user_xattr:
+			f2fs_msg(sb, KERN_INFO,
+				"user_xattr options not supported");
+			break;
+		case Opt_nouser_xattr:
+			f2fs_msg(sb, KERN_INFO,
+				"nouser_xattr options not supported");
+			break;
+		case Opt_inline_xattr:
+			f2fs_msg(sb, KERN_INFO,
+				"inline_xattr options not supported");
+			break;
+		case Opt_noinline_xattr:
+			f2fs_msg(sb, KERN_INFO,
+				"noinline_xattr options not supported");
+			break;
+#endif
+#ifdef CONFIG_F2FS_FS_POSIX_ACL
+		case Opt_acl:
+			set_opt(sbi, POSIX_ACL);
+			break;
+		case Opt_noacl:
+			clear_opt(sbi, POSIX_ACL);
+			break;
+#else
+		case Opt_acl:
+			f2fs_msg(sb, KERN_INFO, "acl options not supported");
+			break;
+		case Opt_noacl:
+			f2fs_msg(sb, KERN_INFO, "noacl options not supported");
+			break;
+#endif
+		case Opt_active_logs:
+			if (args->from && match_int(args, &arg))
+				return -EINVAL;
+			if (arg != 2 && arg != 4 && arg != NR_CURSEG_TYPE)
+				return -EINVAL;
+			F2FS_OPTION(sbi).active_logs = arg;
+			break;
+		case Opt_disable_ext_identify:
+			set_opt(sbi, DISABLE_EXT_IDENTIFY);
+			break;
+		case Opt_inline_data:
+			set_opt(sbi, INLINE_DATA);
+			break;
+		case Opt_inline_dentry:
+			set_opt(sbi, INLINE_DENTRY);
+			break;
+		case Opt_noinline_dentry:
+			clear_opt(sbi, INLINE_DENTRY);
+			break;
+		case Opt_flush_merge:
+			set_opt(sbi, FLUSH_MERGE);
+			break;
+		case Opt_noflush_merge:
+			clear_opt(sbi, FLUSH_MERGE);
+			break;
+		case Opt_nobarrier:
+			set_opt(sbi, NOBARRIER);
+			break;
+		case Opt_fastboot:
+			set_opt(sbi, FASTBOOT);
+			break;
+		case Opt_extent_cache:
+			set_opt(sbi, EXTENT_CACHE);
+			break;
+		case Opt_noextent_cache:
+			clear_opt(sbi, EXTENT_CACHE);
+			break;
+		case Opt_noinline_data:
+			clear_opt(sbi, INLINE_DATA);
+			break;
+		case Opt_data_flush:
+			set_opt(sbi, DATA_FLUSH);
+			break;
+		case Opt_reserve_root:
+			if (args->from && match_int(args, &arg))
+				return -EINVAL;
+			if (test_opt(sbi, RESERVE_ROOT)) {
+				f2fs_msg(sb, KERN_INFO,
+					"Preserve previous reserve_root=%u",
+					F2FS_OPTION(sbi).root_reserved_blocks);
+			} else {
+				F2FS_OPTION(sbi).root_reserved_blocks = arg;
+				set_opt(sbi, RESERVE_ROOT);
+			}
+			break;
+		case Opt_resuid:
+			if (args->from && match_int(args, &arg))
+				return -EINVAL;
+			uid = make_kuid(current_user_ns(), arg);
+			if (!uid_valid(uid)) {
+				f2fs_msg(sb, KERN_ERR,
+					"Invalid uid value %d", arg);
+				return -EINVAL;
+			}
+			F2FS_OPTION(sbi).s_resuid = uid;
+			break;
+		case Opt_resgid:
+			if (args->from && match_int(args, &arg))
+				return -EINVAL;
+			gid = make_kgid(current_user_ns(), arg);
+			if (!gid_valid(gid)) {
+				f2fs_msg(sb, KERN_ERR,
+					"Invalid gid value %d", arg);
+				return -EINVAL;
+			}
+			F2FS_OPTION(sbi).s_resgid = gid;
+			break;
+		case Opt_mode:
+			name = match_strdup(&args[0]);
+
+			if (!name)
+				return -ENOMEM;
+			if (strlen(name) == 8 &&
+					!strncmp(name, "adaptive", 8)) {
+				if (f2fs_sb_has_blkzoned(sb)) {
+					f2fs_msg(sb, KERN_WARNING,
+						 "adaptive mode is not allowed with "
+						 "zoned block device feature");
+					kfree(name);
+					return -EINVAL;
+				}
+				set_opt_mode(sbi, F2FS_MOUNT_ADAPTIVE);
+			} else if (strlen(name) == 3 &&
+					!strncmp(name, "lfs", 3)) {
+				set_opt_mode(sbi, F2FS_MOUNT_LFS);
+			} else {
+				kfree(name);
+				return -EINVAL;
+			}
+			kfree(name);
+			break;
+		case Opt_io_size_bits:
+			if (args->from && match_int(args, &arg))
+				return -EINVAL;
+			if (arg > __ilog2_u32(BIO_MAX_PAGES)) {
+				f2fs_msg(sb, KERN_WARNING,
+					"Not support %d, larger than %d",
+					1 << arg, BIO_MAX_PAGES);
+				return -EINVAL;
+			}
+			F2FS_OPTION(sbi).write_io_size_bits = arg;
+			break;
+		case Opt_fault_injection:
+			if (args->from && match_int(args, &arg))
+				return -EINVAL;
+#ifdef CONFIG_F2FS_FAULT_INJECTION
+			f2fs_build_fault_attr(sbi, arg);
+			set_opt(sbi, FAULT_INJECTION);
+#else
+			f2fs_msg(sb, KERN_INFO,
+				"FAULT_INJECTION was not selected");
+#endif
+			break;
+		case Opt_lazytime:
+			sb->s_flags |= MS_LAZYTIME;
+			break;
+		case Opt_nolazytime:
+			sb->s_flags &= ~MS_LAZYTIME;
+			break;
+#ifdef CONFIG_QUOTA
+		case Opt_quota:
+		case Opt_usrquota:
+			set_opt(sbi, USRQUOTA);
+			break;
+		case Opt_grpquota:
+			set_opt(sbi, GRPQUOTA);
+			break;
+		case Opt_prjquota:
+			set_opt(sbi, PRJQUOTA);
+			break;
+		case Opt_usrjquota:
+			ret = f2fs_set_qf_name(sb, USRQUOTA, &args[0]);
+			if (ret)
+				return ret;
+			break;
+		case Opt_grpjquota:
+			ret = f2fs_set_qf_name(sb, GRPQUOTA, &args[0]);
+			if (ret)
+				return ret;
+			break;
+		case Opt_prjjquota:
+			ret = f2fs_set_qf_name(sb, PRJQUOTA, &args[0]);
+			if (ret)
+				return ret;
+			break;
+		case Opt_offusrjquota:
+			ret = f2fs_clear_qf_name(sb, USRQUOTA);
+			if (ret)
+				return ret;
+			break;
+		case Opt_offgrpjquota:
+			ret = f2fs_clear_qf_name(sb, GRPQUOTA);
+			if (ret)
+				return ret;
+			break;
+		case Opt_offprjjquota:
+			ret = f2fs_clear_qf_name(sb, PRJQUOTA);
+			if (ret)
+				return ret;
+			break;
+		case Opt_jqfmt_vfsold:
+			F2FS_OPTION(sbi).s_jquota_fmt = QFMT_VFS_OLD;
+			break;
+		case Opt_jqfmt_vfsv0:
+			F2FS_OPTION(sbi).s_jquota_fmt = QFMT_VFS_V0;
+			break;
+		case Opt_jqfmt_vfsv1:
+			F2FS_OPTION(sbi).s_jquota_fmt = QFMT_VFS_V1;
+			break;
+		case Opt_noquota:
+			clear_opt(sbi, QUOTA);
+			clear_opt(sbi, USRQUOTA);
+			clear_opt(sbi, GRPQUOTA);
+			clear_opt(sbi, PRJQUOTA);
+			break;
+#else
+		case Opt_quota:
+		case Opt_usrquota:
+		case Opt_grpquota:
+		case Opt_prjquota:
+		case Opt_usrjquota:
+		case Opt_grpjquota:
+		case Opt_prjjquota:
+		case Opt_offusrjquota:
+		case Opt_offgrpjquota:
+		case Opt_offprjjquota:
+		case Opt_jqfmt_vfsold:
+		case Opt_jqfmt_vfsv0:
+		case Opt_jqfmt_vfsv1:
+		case Opt_noquota:
+			f2fs_msg(sb, KERN_INFO,
+					"quota operations not supported");
+			break;
+#endif
+		case Opt_whint:
+			name = match_strdup(&args[0]);
+			if (!name)
+				return -ENOMEM;
+			if (strlen(name) == 10 &&
+					!strncmp(name, "user-based", 10)) {
+				F2FS_OPTION(sbi).whint_mode = WHINT_MODE_USER;
+			} else if (strlen(name) == 3 &&
+					!strncmp(name, "off", 3)) {
+				F2FS_OPTION(sbi).whint_mode = WHINT_MODE_OFF;
+			} else if (strlen(name) == 8 &&
+					!strncmp(name, "fs-based", 8)) {
+				F2FS_OPTION(sbi).whint_mode = WHINT_MODE_FS;
+			} else {
+				kfree(name);
+				return -EINVAL;
+			}
+			kfree(name);
+			break;
+		case Opt_alloc:
+			name = match_strdup(&args[0]);
+			if (!name)
+				return -ENOMEM;
+
+			if (strlen(name) == 7 &&
+					!strncmp(name, "default", 7)) {
+				F2FS_OPTION(sbi).alloc_mode = ALLOC_MODE_DEFAULT;
+			} else if (strlen(name) == 5 &&
+					!strncmp(name, "reuse", 5)) {
+				F2FS_OPTION(sbi).alloc_mode = ALLOC_MODE_REUSE;
+			} else {
+				kfree(name);
+				return -EINVAL;
+			}
+			kfree(name);
+			break;
+		case Opt_fsync:
+			name = match_strdup(&args[0]);
+			if (!name)
+				return -ENOMEM;
+			if (strlen(name) == 5 &&
+					!strncmp(name, "posix", 5)) {
+				F2FS_OPTION(sbi).fsync_mode = FSYNC_MODE_POSIX;
+			} else if (strlen(name) == 6 &&
+					!strncmp(name, "strict", 6)) {
+				F2FS_OPTION(sbi).fsync_mode = FSYNC_MODE_STRICT;
+			} else if (strlen(name) == 9 &&
+					!strncmp(name, "nobarrier", 9)) {
+				F2FS_OPTION(sbi).fsync_mode =
+							FSYNC_MODE_NOBARRIER;
+			} else {
+				kfree(name);
+				return -EINVAL;
+			}
+			kfree(name);
+			break;
+		case Opt_test_dummy_encryption:
+#ifdef CONFIG_F2FS_FS_ENCRYPTION
+			if (!f2fs_sb_has_encrypt(sb)) {
+				f2fs_msg(sb, KERN_ERR, "Encrypt feature is off");
+				return -EINVAL;
+			}
+
+			F2FS_OPTION(sbi).test_dummy_encryption = true;
+			f2fs_msg(sb, KERN_INFO,
+					"Test dummy encryption mode enabled");
+#else
+			f2fs_msg(sb, KERN_INFO,
+					"Test dummy encryption mount option ignored");
+#endif
+			break;
+		default:
+			f2fs_msg(sb, KERN_ERR,
+				"Unrecognized mount option \"%s\" or missing value",
+				p);
+			return -EINVAL;
+		}
+	}
+#ifdef CONFIG_QUOTA
+	if (f2fs_check_quota_options(sbi))
+		return -EINVAL;
+#endif
+
+	if (F2FS_IO_SIZE_BITS(sbi) && !test_opt(sbi, LFS)) {
+		f2fs_msg(sb, KERN_ERR,
+				"Should set mode=lfs with %uKB-sized IO",
+				F2FS_IO_SIZE_KB(sbi));
+		return -EINVAL;
+	}
+
+	if (test_opt(sbi, INLINE_XATTR_SIZE)) {
+		if (!f2fs_sb_has_extra_attr(sb) ||
+			!f2fs_sb_has_flexible_inline_xattr(sb)) {
+			f2fs_msg(sb, KERN_ERR,
+					"extra_attr or flexible_inline_xattr "
+					"feature is off");
+			return -EINVAL;
+		}
+		if (!test_opt(sbi, INLINE_XATTR)) {
+			f2fs_msg(sb, KERN_ERR,
+					"inline_xattr_size option should be "
+					"set with inline_xattr option");
+			return -EINVAL;
+		}
+		if (!F2FS_OPTION(sbi).inline_xattr_size ||
+			F2FS_OPTION(sbi).inline_xattr_size >=
+					DEF_ADDRS_PER_INODE -
+					F2FS_TOTAL_EXTRA_ATTR_SIZE -
+					DEF_INLINE_RESERVED_SIZE -
+					DEF_MIN_INLINE_SIZE) {
+			f2fs_msg(sb, KERN_ERR,
+					"inline xattr size is out of range");
+			return -EINVAL;
+		}
+	}
+
+	/* Not pass down write hints if the number of active logs is lesser
+	 * than NR_CURSEG_TYPE.
+	 */
+	if (F2FS_OPTION(sbi).active_logs != NR_CURSEG_TYPE)
+		F2FS_OPTION(sbi).whint_mode = WHINT_MODE_OFF;
+	return 0;
+}
+
+static struct inode *f2fs_alloc_inode(struct super_block *sb)
+{
+	struct f2fs_inode_info *fi;
+
+	fi = kmem_cache_alloc(f2fs_inode_cachep, GFP_F2FS_ZERO);
+	if (!fi)
+		return NULL;
+
+	init_once((void *) fi);
+
+	/* Initialize f2fs-specific inode info */
+	atomic_set(&fi->dirty_pages, 0);
+	fi->i_current_depth = 1;
+	init_rwsem(&fi->i_sem);
+	INIT_LIST_HEAD(&fi->dirty_list);
+	INIT_LIST_HEAD(&fi->gdirty_list);
+	INIT_LIST_HEAD(&fi->inmem_ilist);
+	INIT_LIST_HEAD(&fi->inmem_pages);
+	mutex_init(&fi->inmem_lock);
+	init_rwsem(&fi->dio_rwsem[READ]);
+	init_rwsem(&fi->dio_rwsem[WRITE]);
+	init_rwsem(&fi->i_mmap_sem);
+	init_rwsem(&fi->i_xattr_sem);
+
+	/* Will be used by directory only */
+	fi->i_dir_level = F2FS_SB(sb)->dir_level;
+
+	return &fi->vfs_inode;
+}
+
+static int f2fs_drop_inode(struct inode *inode)
+{
+	int ret;
+	/*
+	 * This is to avoid a deadlock condition like below.
+	 * writeback_single_inode(inode)
+	 *  - f2fs_write_data_page
+	 *    - f2fs_gc -> iput -> evict
+	 *       - inode_wait_for_writeback(inode)
+	 */
+	if ((!inode_unhashed(inode) && inode->i_state & I_SYNC)) {
+		if (!inode->i_nlink && !is_bad_inode(inode)) {
+			/* to avoid evict_inode call simultaneously */
+			atomic_inc(&inode->i_count);
+			spin_unlock(&inode->i_lock);
+
+			/* some remained atomic pages should discarded */
+			if (f2fs_is_atomic_file(inode))
+				drop_inmem_pages(inode);
+
+			/* should remain fi->extent_tree for writepage */
+			f2fs_destroy_extent_node(inode);
+
+			sb_start_intwrite(inode->i_sb);
+			f2fs_i_size_write(inode, 0);
+
+			if (F2FS_HAS_BLOCKS(inode))
+				f2fs_truncate(inode);
+
+			sb_end_intwrite(inode->i_sb);
+
+			spin_lock(&inode->i_lock);
+			atomic_dec(&inode->i_count);
+		}
+		trace_f2fs_drop_inode(inode, 0);
+		return 0;
+	}
+	ret = generic_drop_inode(inode);
+	trace_f2fs_drop_inode(inode, ret);
+	return ret;
+}
+
+int f2fs_inode_dirtied(struct inode *inode, bool sync)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	int ret = 0;
+
+	spin_lock(&sbi->inode_lock[DIRTY_META]);
+	if (is_inode_flag_set(inode, FI_DIRTY_INODE)) {
+		ret = 1;
+	} else {
+		set_inode_flag(inode, FI_DIRTY_INODE);
+		stat_inc_dirty_inode(sbi, DIRTY_META);
+	}
+	if (sync && list_empty(&F2FS_I(inode)->gdirty_list)) {
+		list_add_tail(&F2FS_I(inode)->gdirty_list,
+				&sbi->inode_list[DIRTY_META]);
+		inc_page_count(sbi, F2FS_DIRTY_IMETA);
+	}
+	spin_unlock(&sbi->inode_lock[DIRTY_META]);
+	return ret;
+}
+
+void f2fs_inode_synced(struct inode *inode)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+
+	spin_lock(&sbi->inode_lock[DIRTY_META]);
+	if (!is_inode_flag_set(inode, FI_DIRTY_INODE)) {
+		spin_unlock(&sbi->inode_lock[DIRTY_META]);
+		return;
+	}
+	if (!list_empty(&F2FS_I(inode)->gdirty_list)) {
+		list_del_init(&F2FS_I(inode)->gdirty_list);
+		dec_page_count(sbi, F2FS_DIRTY_IMETA);
+	}
+	clear_inode_flag(inode, FI_DIRTY_INODE);
+	clear_inode_flag(inode, FI_AUTO_RECOVER);
+	stat_dec_dirty_inode(F2FS_I_SB(inode), DIRTY_META);
+	spin_unlock(&sbi->inode_lock[DIRTY_META]);
+}
+
+/*
+ * f2fs_dirty_inode() is called from __mark_inode_dirty()
+ *
+ * We should call set_dirty_inode to write the dirty inode through write_inode.
+ */
+static void f2fs_dirty_inode(struct inode *inode, int flags)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+
+	if (inode->i_ino == F2FS_NODE_INO(sbi) ||
+			inode->i_ino == F2FS_META_INO(sbi))
+		return;
+
+	if (flags == I_DIRTY_TIME)
+		return;
+
+	if (is_inode_flag_set(inode, FI_AUTO_RECOVER))
+		clear_inode_flag(inode, FI_AUTO_RECOVER);
+
+	f2fs_inode_dirtied(inode, false);
+}
+
+static void f2fs_i_callback(struct rcu_head *head)
+{
+	struct inode *inode = container_of(head, struct inode, i_rcu);
+	kmem_cache_free(f2fs_inode_cachep, F2FS_I(inode));
+}
+
+static void f2fs_destroy_inode(struct inode *inode)
+{
+	call_rcu(&inode->i_rcu, f2fs_i_callback);
+}
+
+static void destroy_percpu_info(struct f2fs_sb_info *sbi)
+{
+	percpu_counter_destroy(&sbi->alloc_valid_block_count);
+	percpu_counter_destroy(&sbi->total_valid_inode_count);
+}
+
+static void destroy_device_list(struct f2fs_sb_info *sbi)
+{
+	int i;
+
+	for (i = 0; i < sbi->s_ndevs; i++) {
+		blkdev_put(FDEV(i).bdev, FMODE_EXCL);
+#ifdef CONFIG_BLK_DEV_ZONED
+		kfree(FDEV(i).blkz_type);
+#endif
+	}
+	kfree(sbi->devs);
+}
+
+static void f2fs_put_super(struct super_block *sb)
+{
+	struct f2fs_sb_info *sbi = F2FS_SB(sb);
+	int i;
+	bool dropped;
+
+	/* unregister procfs/sysfs entries in advance to avoid race case */
+	f2fs_unregister_sysfs(sbi);
+
+	f2fs_quota_off_umount(sb);
+
+	/* prevent remaining shrinker jobs */
+	mutex_lock(&sbi->umount_mutex);
+
+	/*
+	 * We don't need to do checkpoint when superblock is clean.
+	 * But, the previous checkpoint was not done by umount, it needs to do
+	 * clean checkpoint again.
+	 */
+	if (is_sbi_flag_set(sbi, SBI_IS_DIRTY) ||
+			!is_set_ckpt_flags(sbi, CP_UMOUNT_FLAG)) {
+		struct cp_control cpc = {
+			.reason = CP_UMOUNT,
+		};
+		write_checkpoint(sbi, &cpc);
+	}
+
+	/* be sure to wait for any on-going discard commands */
+	dropped = f2fs_wait_discard_bios(sbi);
+
+	if (f2fs_discard_en(sbi) && !sbi->discard_blks && !dropped) {
+		struct cp_control cpc = {
+			.reason = CP_UMOUNT | CP_TRIMMED,
+		};
+		write_checkpoint(sbi, &cpc);
+	}
+
+	/* write_checkpoint can update stat informaion */
+	f2fs_destroy_stats(sbi);
+
+	/*
+	 * normally superblock is clean, so we need to release this.
+	 * In addition, EIO will skip do checkpoint, we need this as well.
+	 */
+	release_ino_entry(sbi, true);
+
+	f2fs_leave_shrinker(sbi);
+	mutex_unlock(&sbi->umount_mutex);
+
+	/* our cp_error case, we can wait for any writeback page */
+	f2fs_flush_merged_writes(sbi);
+
+	iput(sbi->node_inode);
+	iput(sbi->meta_inode);
+
+	/* destroy f2fs internal modules */
+	destroy_node_manager(sbi);
+	destroy_segment_manager(sbi);
+
+	kfree(sbi->ckpt);
+
+	sb->s_fs_info = NULL;
+	if (sbi->s_chksum_driver)
+		crypto_free_shash(sbi->s_chksum_driver);
+	kfree(sbi->raw_super);
+
+	destroy_device_list(sbi);
+	mempool_destroy(sbi->write_io_dummy);
+#ifdef CONFIG_QUOTA
+	for (i = 0; i < MAXQUOTAS; i++)
+		kfree(F2FS_OPTION(sbi).s_qf_names[i]);
+#endif
+	destroy_percpu_info(sbi);
+	for (i = 0; i < NR_PAGE_TYPE; i++)
+		kfree(sbi->write_io[i]);
+	kfree(sbi);
+}
+
+int f2fs_sync_fs(struct super_block *sb, int sync)
+{
+	struct f2fs_sb_info *sbi = F2FS_SB(sb);
+	int err = 0;
+
+	if (unlikely(f2fs_cp_error(sbi)))
+		return 0;
+
+	trace_f2fs_sync_fs(sb, sync);
+
+	if (unlikely(is_sbi_flag_set(sbi, SBI_POR_DOING)))
+		return -EAGAIN;
+
+	if (sync) {
+		struct cp_control cpc;
+
+		cpc.reason = __get_cp_reason(sbi);
+
+		mutex_lock(&sbi->gc_mutex);
+		err = write_checkpoint(sbi, &cpc);
+		mutex_unlock(&sbi->gc_mutex);
+	}
+	f2fs_trace_ios(NULL, 1);
+
+	return err;
+}
+
+static int f2fs_freeze(struct super_block *sb)
+{
+	if (f2fs_readonly(sb))
+		return 0;
+
+	/* IO error happened before */
+	if (unlikely(f2fs_cp_error(F2FS_SB(sb))))
+		return -EIO;
+
+	/* must be clean, since sync_filesystem() was already called */
+	if (is_sbi_flag_set(F2FS_SB(sb), SBI_IS_DIRTY))
+		return -EINVAL;
+	return 0;
+}
+
+static int f2fs_unfreeze(struct super_block *sb)
+{
+	return 0;
+}
+
+#ifdef CONFIG_QUOTA
+static int f2fs_statfs_project(struct super_block *sb,
+				kprojid_t projid, struct kstatfs *buf)
+{
+	struct kqid qid;
+	struct dquot *dquot;
+	u64 limit;
+	u64 curblock;
+
+	qid = make_kqid_projid(projid);
+	dquot = dqget(sb, qid);
+	if (IS_ERR(dquot))
+		return PTR_ERR(dquot);
+	spin_lock(&dq_data_lock);
+
+	limit = min_not_zero(dquot->dq_dqb.dqb_bsoftlimit,
+					dquot->dq_dqb.dqb_bhardlimit);
+	if (limit)
+		limit >>= sb->s_blocksize_bits;
+
+	if (limit && buf->f_blocks > limit) {
+		curblock = (dquot->dq_dqb.dqb_curspace +
+			    dquot->dq_dqb.dqb_rsvspace) >> sb->s_blocksize_bits;
+		buf->f_blocks = limit;
+		buf->f_bfree = buf->f_bavail =
+			(buf->f_blocks > curblock) ?
+			 (buf->f_blocks - curblock) : 0;
+	}
+
+	limit = min_not_zero(dquot->dq_dqb.dqb_isoftlimit,
+					dquot->dq_dqb.dqb_ihardlimit);
+
+	if (limit && buf->f_files > limit) {
+		buf->f_files = limit;
+		buf->f_ffree =
+			(buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
+			 (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
+	}
+
+	spin_unlock(&dq_data_lock);
+	dqput(dquot);
+	return 0;
+}
+#endif
+
+static int f2fs_statfs(struct dentry *dentry, struct kstatfs *buf)
+{
+	struct super_block *sb = dentry->d_sb;
+	struct f2fs_sb_info *sbi = F2FS_SB(sb);
+	u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
+	block_t total_count, user_block_count, start_count;
+	u64 avail_node_count;
+
+	total_count = le64_to_cpu(sbi->raw_super->block_count);
+	user_block_count = sbi->user_block_count;
+	start_count = le32_to_cpu(sbi->raw_super->segment0_blkaddr);
+	buf->f_type = F2FS_SUPER_MAGIC;
+	buf->f_bsize = sbi->blocksize;
+
+	buf->f_blocks = total_count - start_count;
+	buf->f_bfree = user_block_count - valid_user_blocks(sbi) -
+						sbi->current_reserved_blocks;
+	if (buf->f_bfree > F2FS_OPTION(sbi).root_reserved_blocks)
+		buf->f_bavail = buf->f_bfree -
+				F2FS_OPTION(sbi).root_reserved_blocks;
+	else
+		buf->f_bavail = 0;
+
+	avail_node_count = sbi->total_node_count - sbi->nquota_files -
+						F2FS_RESERVED_NODE_NUM;
+
+	if (avail_node_count > user_block_count) {
+		buf->f_files = user_block_count;
+		buf->f_ffree = buf->f_bavail;
+	} else {
+		buf->f_files = avail_node_count;
+		buf->f_ffree = min(avail_node_count - valid_node_count(sbi),
+					buf->f_bavail);
+	}
+
+	buf->f_namelen = F2FS_NAME_LEN;
+	buf->f_fsid.val[0] = (u32)id;
+	buf->f_fsid.val[1] = (u32)(id >> 32);
+
+#ifdef CONFIG_QUOTA
+	if (is_inode_flag_set(dentry->d_inode, FI_PROJ_INHERIT) &&
+			sb_has_quota_limits_enabled(sb, PRJQUOTA)) {
+		f2fs_statfs_project(sb, F2FS_I(dentry->d_inode)->i_projid, buf);
+	}
+#endif
+	return 0;
+}
+
+static inline void f2fs_show_quota_options(struct seq_file *seq,
+					   struct super_block *sb)
+{
+#ifdef CONFIG_QUOTA
+	struct f2fs_sb_info *sbi = F2FS_SB(sb);
+
+	if (F2FS_OPTION(sbi).s_jquota_fmt) {
+		char *fmtname = "";
+
+		switch (F2FS_OPTION(sbi).s_jquota_fmt) {
+		case QFMT_VFS_OLD:
+			fmtname = "vfsold";
+			break;
+		case QFMT_VFS_V0:
+			fmtname = "vfsv0";
+			break;
+		case QFMT_VFS_V1:
+			fmtname = "vfsv1";
+			break;
+		}
+		seq_printf(seq, ",jqfmt=%s", fmtname);
+	}
+
+	if (F2FS_OPTION(sbi).s_qf_names[USRQUOTA])
+		seq_show_option(seq, "usrjquota",
+			F2FS_OPTION(sbi).s_qf_names[USRQUOTA]);
+
+	if (F2FS_OPTION(sbi).s_qf_names[GRPQUOTA])
+		seq_show_option(seq, "grpjquota",
+			F2FS_OPTION(sbi).s_qf_names[GRPQUOTA]);
+
+	if (F2FS_OPTION(sbi).s_qf_names[PRJQUOTA])
+		seq_show_option(seq, "prjjquota",
+			F2FS_OPTION(sbi).s_qf_names[PRJQUOTA]);
+#endif
+}
+
+static int f2fs_show_options(struct seq_file *seq, struct dentry *root)
+{
+	struct f2fs_sb_info *sbi = F2FS_SB(root->d_sb);
+
+	if (!f2fs_readonly(sbi->sb) && test_opt(sbi, BG_GC)) {
+		if (test_opt(sbi, FORCE_FG_GC))
+			seq_printf(seq, ",background_gc=%s", "sync");
+		else
+			seq_printf(seq, ",background_gc=%s", "on");
+	} else {
+		seq_printf(seq, ",background_gc=%s", "off");
+	}
+	if (test_opt(sbi, DISABLE_ROLL_FORWARD))
+		seq_puts(seq, ",disable_roll_forward");
+	if (test_opt(sbi, DISCARD))
+		seq_puts(seq, ",discard");
+	if (test_opt(sbi, NOHEAP))
+		seq_puts(seq, ",no_heap");
+	else
+		seq_puts(seq, ",heap");
+#ifdef CONFIG_F2FS_FS_XATTR
+	if (test_opt(sbi, XATTR_USER))
+		seq_puts(seq, ",user_xattr");
+	else
+		seq_puts(seq, ",nouser_xattr");
+	if (test_opt(sbi, INLINE_XATTR))
+		seq_puts(seq, ",inline_xattr");
+	else
+		seq_puts(seq, ",noinline_xattr");
+	if (test_opt(sbi, INLINE_XATTR_SIZE))
+		seq_printf(seq, ",inline_xattr_size=%u",
+					F2FS_OPTION(sbi).inline_xattr_size);
+#endif
+#ifdef CONFIG_F2FS_FS_POSIX_ACL
+	if (test_opt(sbi, POSIX_ACL))
+		seq_puts(seq, ",acl");
+	else
+		seq_puts(seq, ",noacl");
+#endif
+	if (test_opt(sbi, DISABLE_EXT_IDENTIFY))
+		seq_puts(seq, ",disable_ext_identify");
+	if (test_opt(sbi, INLINE_DATA))
+		seq_puts(seq, ",inline_data");
+	else
+		seq_puts(seq, ",noinline_data");
+	if (test_opt(sbi, INLINE_DENTRY))
+		seq_puts(seq, ",inline_dentry");
+	else
+		seq_puts(seq, ",noinline_dentry");
+	if (!f2fs_readonly(sbi->sb) && test_opt(sbi, FLUSH_MERGE))
+		seq_puts(seq, ",flush_merge");
+	if (test_opt(sbi, NOBARRIER))
+		seq_puts(seq, ",nobarrier");
+	if (test_opt(sbi, FASTBOOT))
+		seq_puts(seq, ",fastboot");
+	if (test_opt(sbi, EXTENT_CACHE))
+		seq_puts(seq, ",extent_cache");
+	else
+		seq_puts(seq, ",noextent_cache");
+	if (test_opt(sbi, DATA_FLUSH))
+		seq_puts(seq, ",data_flush");
+
+	seq_puts(seq, ",mode=");
+	if (test_opt(sbi, ADAPTIVE))
+		seq_puts(seq, "adaptive");
+	else if (test_opt(sbi, LFS))
+		seq_puts(seq, "lfs");
+	seq_printf(seq, ",active_logs=%u", F2FS_OPTION(sbi).active_logs);
+	if (test_opt(sbi, RESERVE_ROOT))
+		seq_printf(seq, ",reserve_root=%u,resuid=%u,resgid=%u",
+				F2FS_OPTION(sbi).root_reserved_blocks,
+				from_kuid_munged(&init_user_ns,
+					F2FS_OPTION(sbi).s_resuid),
+				from_kgid_munged(&init_user_ns,
+					F2FS_OPTION(sbi).s_resgid));
+	if (F2FS_IO_SIZE_BITS(sbi))
+		seq_printf(seq, ",io_size=%uKB", F2FS_IO_SIZE_KB(sbi));
+#ifdef CONFIG_F2FS_FAULT_INJECTION
+	if (test_opt(sbi, FAULT_INJECTION))
+		seq_printf(seq, ",fault_injection=%u",
+				F2FS_OPTION(sbi).fault_info.inject_rate);
+#endif
+#ifdef CONFIG_QUOTA
+	if (test_opt(sbi, QUOTA))
+		seq_puts(seq, ",quota");
+	if (test_opt(sbi, USRQUOTA))
+		seq_puts(seq, ",usrquota");
+	if (test_opt(sbi, GRPQUOTA))
+		seq_puts(seq, ",grpquota");
+	if (test_opt(sbi, PRJQUOTA))
+		seq_puts(seq, ",prjquota");
+#endif
+	f2fs_show_quota_options(seq, sbi->sb);
+	if (F2FS_OPTION(sbi).whint_mode == WHINT_MODE_USER)
+		seq_printf(seq, ",whint_mode=%s", "user-based");
+	else if (F2FS_OPTION(sbi).whint_mode == WHINT_MODE_FS)
+		seq_printf(seq, ",whint_mode=%s", "fs-based");
+#ifdef CONFIG_F2FS_FS_ENCRYPTION
+	if (F2FS_OPTION(sbi).test_dummy_encryption)
+		seq_puts(seq, ",test_dummy_encryption");
+#endif
+
+	if (F2FS_OPTION(sbi).alloc_mode == ALLOC_MODE_DEFAULT)
+		seq_printf(seq, ",alloc_mode=%s", "default");
+	else if (F2FS_OPTION(sbi).alloc_mode == ALLOC_MODE_REUSE)
+		seq_printf(seq, ",alloc_mode=%s", "reuse");
+
+	if (F2FS_OPTION(sbi).fsync_mode == FSYNC_MODE_POSIX)
+		seq_printf(seq, ",fsync_mode=%s", "posix");
+	else if (F2FS_OPTION(sbi).fsync_mode == FSYNC_MODE_STRICT)
+		seq_printf(seq, ",fsync_mode=%s", "strict");
+	return 0;
+}
+
+static void default_options(struct f2fs_sb_info *sbi)
+{
+	/* init some FS parameters */
+	F2FS_OPTION(sbi).active_logs = NR_CURSEG_TYPE;
+	F2FS_OPTION(sbi).inline_xattr_size = DEFAULT_INLINE_XATTR_ADDRS;
+	F2FS_OPTION(sbi).whint_mode = WHINT_MODE_OFF;
+	F2FS_OPTION(sbi).alloc_mode = ALLOC_MODE_DEFAULT;
+	F2FS_OPTION(sbi).fsync_mode = FSYNC_MODE_POSIX;
+	F2FS_OPTION(sbi).test_dummy_encryption = false;
+	sbi->readdir_ra = 1;
+
+	set_opt(sbi, BG_GC);
+	set_opt(sbi, INLINE_XATTR);
+	set_opt(sbi, INLINE_DATA);
+	set_opt(sbi, INLINE_DENTRY);
+	set_opt(sbi, EXTENT_CACHE);
+	set_opt(sbi, NOHEAP);
+	sbi->sb->s_flags |= MS_LAZYTIME;
+	set_opt(sbi, FLUSH_MERGE);
+	if (f2fs_sb_has_blkzoned(sbi->sb)) {
+		set_opt_mode(sbi, F2FS_MOUNT_LFS);
+		set_opt(sbi, DISCARD);
+	} else {
+		set_opt_mode(sbi, F2FS_MOUNT_ADAPTIVE);
+	}
+
+#ifdef CONFIG_F2FS_FS_XATTR
+	set_opt(sbi, XATTR_USER);
+#endif
+#ifdef CONFIG_F2FS_FS_POSIX_ACL
+	set_opt(sbi, POSIX_ACL);
+#endif
+
+#ifdef CONFIG_F2FS_FAULT_INJECTION
+	f2fs_build_fault_attr(sbi, 0);
+#endif
+}
+
+#ifdef CONFIG_QUOTA
+static int f2fs_enable_quotas(struct super_block *sb);
+#endif
+static int f2fs_remount(struct super_block *sb, int *flags, char *data)
+{
+	struct f2fs_sb_info *sbi = F2FS_SB(sb);
+	struct f2fs_mount_info org_mount_opt;
+	unsigned long old_sb_flags;
+	int err;
+	bool need_restart_gc = false;
+	bool need_stop_gc = false;
+	bool no_extent_cache = !test_opt(sbi, EXTENT_CACHE);
+#ifdef CONFIG_QUOTA
+	int i, j;
+#endif
+
+	/*
+	 * Save the old mount options in case we
+	 * need to restore them.
+	 */
+	org_mount_opt = sbi->mount_opt;
+	old_sb_flags = sb->s_flags;
+
+#ifdef CONFIG_QUOTA
+	org_mount_opt.s_jquota_fmt = F2FS_OPTION(sbi).s_jquota_fmt;
+	for (i = 0; i < MAXQUOTAS; i++) {
+		if (F2FS_OPTION(sbi).s_qf_names[i]) {
+			org_mount_opt.s_qf_names[i] =
+				kstrdup(F2FS_OPTION(sbi).s_qf_names[i],
+				GFP_KERNEL);
+			if (!org_mount_opt.s_qf_names[i]) {
+				for (j = 0; j < i; j++)
+					kfree(org_mount_opt.s_qf_names[j]);
+				return -ENOMEM;
+			}
+		} else {
+			org_mount_opt.s_qf_names[i] = NULL;
+		}
+	}
+#endif
+
+	/* recover superblocks we couldn't write due to previous RO mount */
+	if (!(*flags & MS_RDONLY) && is_sbi_flag_set(sbi, SBI_NEED_SB_WRITE)) {
+		err = f2fs_commit_super(sbi, false);
+		f2fs_msg(sb, KERN_INFO,
+			"Try to recover all the superblocks, ret: %d", err);
+		if (!err)
+			clear_sbi_flag(sbi, SBI_NEED_SB_WRITE);
+	}
+
+	default_options(sbi);
+
+	/* parse mount options */
+	err = parse_options(sb, data);
+	if (err)
+		goto restore_opts;
+
+	/*
+	 * Previous and new state of filesystem is RO,
+	 * so skip checking GC and FLUSH_MERGE conditions.
+	 */
+	if (f2fs_readonly(sb) && (*flags & MS_RDONLY))
+		goto skip;
+
+#ifdef CONFIG_QUOTA
+	if (!f2fs_readonly(sb) && (*flags & MS_RDONLY)) {
+		err = dquot_suspend(sb, -1);
+		if (err < 0)
+			goto restore_opts;
+	} else if (f2fs_readonly(sb) && !(*flags & MS_RDONLY)) {
+		/* dquot_resume needs RW */
+		sb->s_flags &= ~MS_RDONLY;
+		if (sb_any_quota_suspended(sb)) {
+			dquot_resume(sb, -1);
+		} else if (f2fs_sb_has_quota_ino(sb)) {
+			err = f2fs_enable_quotas(sb);
+			if (err)
+				goto restore_opts;
+		}
+	}
+#endif
+	/* disallow enable/disable extent_cache dynamically */
+	if (no_extent_cache == !!test_opt(sbi, EXTENT_CACHE)) {
+		err = -EINVAL;
+		f2fs_msg(sbi->sb, KERN_WARNING,
+				"switch extent_cache option is not allowed");
+		goto restore_opts;
+	}
+
+	/*
+	 * We stop the GC thread if FS is mounted as RO
+	 * or if background_gc = off is passed in mount
+	 * option. Also sync the filesystem.
+	 */
+	if ((*flags & MS_RDONLY) || !test_opt(sbi, BG_GC)) {
+		if (sbi->gc_thread) {
+			stop_gc_thread(sbi);
+			need_restart_gc = true;
+		}
+	} else if (!sbi->gc_thread) {
+		err = start_gc_thread(sbi);
+		if (err)
+			goto restore_opts;
+		need_stop_gc = true;
+	}
+
+	if (*flags & MS_RDONLY ||
+		F2FS_OPTION(sbi).whint_mode != org_mount_opt.whint_mode) {
+		writeback_inodes_sb(sb, WB_REASON_SYNC);
+		sync_inodes_sb(sb);
+
+		set_sbi_flag(sbi, SBI_IS_DIRTY);
+		set_sbi_flag(sbi, SBI_IS_CLOSE);
+		f2fs_sync_fs(sb, 1);
+		clear_sbi_flag(sbi, SBI_IS_CLOSE);
+	}
+
+	/*
+	 * We stop issue flush thread if FS is mounted as RO
+	 * or if flush_merge is not passed in mount option.
+	 */
+	if ((*flags & MS_RDONLY) || !test_opt(sbi, FLUSH_MERGE)) {
+		clear_opt(sbi, FLUSH_MERGE);
+		destroy_flush_cmd_control(sbi, false);
+	} else {
+		err = create_flush_cmd_control(sbi);
+		if (err)
+			goto restore_gc;
+	}
+skip:
+#ifdef CONFIG_QUOTA
+	/* Release old quota file names */
+	for (i = 0; i < MAXQUOTAS; i++)
+		kfree(org_mount_opt.s_qf_names[i]);
+#endif
+	/* Update the POSIXACL Flag */
+	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
+		(test_opt(sbi, POSIX_ACL) ? MS_POSIXACL : 0);
+
+	limit_reserve_root(sbi);
+	return 0;
+restore_gc:
+	if (need_restart_gc) {
+		if (start_gc_thread(sbi))
+			f2fs_msg(sbi->sb, KERN_WARNING,
+				"background gc thread has stopped");
+	} else if (need_stop_gc) {
+		stop_gc_thread(sbi);
+	}
+restore_opts:
+#ifdef CONFIG_QUOTA
+	F2FS_OPTION(sbi).s_jquota_fmt = org_mount_opt.s_jquota_fmt;
+	for (i = 0; i < MAXQUOTAS; i++) {
+		kfree(F2FS_OPTION(sbi).s_qf_names[i]);
+		F2FS_OPTION(sbi).s_qf_names[i] = org_mount_opt.s_qf_names[i];
+	}
+#endif
+	sbi->mount_opt = org_mount_opt;
+	sb->s_flags = old_sb_flags;
+	return err;
+}
+
+#ifdef CONFIG_QUOTA
+/* Read data from quotafile */
+static ssize_t f2fs_quota_read(struct super_block *sb, int type, char *data,
+			       size_t len, loff_t off)
+{
+	struct inode *inode = sb_dqopt(sb)->files[type];
+	struct address_space *mapping = inode->i_mapping;
+	block_t blkidx = F2FS_BYTES_TO_BLK(off);
+	int offset = off & (sb->s_blocksize - 1);
+	int tocopy;
+	size_t toread;
+	loff_t i_size = i_size_read(inode);
+	struct page *page;
+	char *kaddr;
+
+	if (off > i_size)
+		return 0;
+
+	if (off + len > i_size)
+		len = i_size - off;
+	toread = len;
+	while (toread > 0) {
+		tocopy = min_t(unsigned long, sb->s_blocksize - offset, toread);
+repeat:
+		page = read_cache_page_gfp(mapping, blkidx, GFP_NOFS);
+		if (IS_ERR(page)) {
+			if (PTR_ERR(page) == -ENOMEM) {
+				congestion_wait(BLK_RW_ASYNC, HZ/50);
+				goto repeat;
+			}
+			return PTR_ERR(page);
+		}
+
+		lock_page(page);
+
+		if (unlikely(page->mapping != mapping)) {
+			f2fs_put_page(page, 1);
+			goto repeat;
+		}
+		if (unlikely(!PageUptodate(page))) {
+			f2fs_put_page(page, 1);
+			return -EIO;
+		}
+
+		kaddr = kmap_atomic(page);
+		memcpy(data, kaddr + offset, tocopy);
+		kunmap_atomic(kaddr);
+		f2fs_put_page(page, 1);
+
+		offset = 0;
+		toread -= tocopy;
+		data += tocopy;
+		blkidx++;
+	}
+	return len;
+}
+
+/* Write to quotafile */
+static ssize_t f2fs_quota_write(struct super_block *sb, int type,
+				const char *data, size_t len, loff_t off)
+{
+	struct inode *inode = sb_dqopt(sb)->files[type];
+	struct address_space *mapping = inode->i_mapping;
+	const struct address_space_operations *a_ops = mapping->a_ops;
+	int offset = off & (sb->s_blocksize - 1);
+	size_t towrite = len;
+	struct page *page;
+	char *kaddr;
+	int err = 0;
+	int tocopy;
+
+	while (towrite > 0) {
+		tocopy = min_t(unsigned long, sb->s_blocksize - offset,
+								towrite);
+retry:
+		err = a_ops->write_begin(NULL, mapping, off, tocopy, 0,
+							&page, NULL);
+		if (unlikely(err)) {
+			if (err == -ENOMEM) {
+				congestion_wait(BLK_RW_ASYNC, HZ/50);
+				goto retry;
+			}
+			break;
+		}
+
+		kaddr = kmap_atomic(page);
+		memcpy(kaddr + offset, data, tocopy);
+		kunmap_atomic(kaddr);
+		flush_dcache_page(page);
+
+		a_ops->write_end(NULL, mapping, off, tocopy, tocopy,
+						page, NULL);
+		offset = 0;
+		towrite -= tocopy;
+		off += tocopy;
+		data += tocopy;
+		cond_resched();
+	}
+
+	if (len == towrite)
+		return err;
+	inode->i_mtime = inode->i_ctime = current_time(inode);
+	f2fs_mark_inode_dirty_sync(inode, false);
+	return len - towrite;
+}
+
+static struct dquot **f2fs_get_dquots(struct inode *inode)
+{
+	return F2FS_I(inode)->i_dquot;
+}
+
+static qsize_t *f2fs_get_reserved_space(struct inode *inode)
+{
+	return &F2FS_I(inode)->i_reserved_quota;
+}
+
+static int f2fs_quota_on_mount(struct f2fs_sb_info *sbi, int type)
+{
+	return dquot_quota_on_mount(sbi->sb, F2FS_OPTION(sbi).s_qf_names[type],
+					F2FS_OPTION(sbi).s_jquota_fmt, type);
+}
+
+int f2fs_enable_quota_files(struct f2fs_sb_info *sbi, bool rdonly)
+{
+	int enabled = 0;
+	int i, err;
+
+	if (f2fs_sb_has_quota_ino(sbi->sb) && rdonly) {
+		err = f2fs_enable_quotas(sbi->sb);
+		if (err) {
+			f2fs_msg(sbi->sb, KERN_ERR,
+					"Cannot turn on quota_ino: %d", err);
+			return 0;
+		}
+		return 1;
+	}
+
+	for (i = 0; i < MAXQUOTAS; i++) {
+		if (F2FS_OPTION(sbi).s_qf_names[i]) {
+			err = f2fs_quota_on_mount(sbi, i);
+			if (!err) {
+				enabled = 1;
+				continue;
+			}
+			f2fs_msg(sbi->sb, KERN_ERR,
+				"Cannot turn on quotas: %d on %d", err, i);
+		}
+	}
+	return enabled;
+}
+
+static int f2fs_quota_enable(struct super_block *sb, int type, int format_id,
+			     unsigned int flags)
+{
+	struct inode *qf_inode;
+	unsigned long qf_inum;
+	int err;
+
+	BUG_ON(!f2fs_sb_has_quota_ino(sb));
+
+	qf_inum = f2fs_qf_ino(sb, type);
+	if (!qf_inum)
+		return -EPERM;
+
+	qf_inode = f2fs_iget(sb, qf_inum);
+	if (IS_ERR(qf_inode)) {
+		f2fs_msg(sb, KERN_ERR,
+			"Bad quota inode %u:%lu", type, qf_inum);
+		return PTR_ERR(qf_inode);
+	}
+
+	/* Don't account quota for quota files to avoid recursion */
+	qf_inode->i_flags |= S_NOQUOTA;
+	err = dquot_enable(qf_inode, type, format_id, flags);
+	iput(qf_inode);
+	return err;
+}
+
+static int f2fs_enable_quotas(struct super_block *sb)
+{
+	int type, err = 0;
+	unsigned long qf_inum;
+	bool quota_mopt[MAXQUOTAS] = {
+		test_opt(F2FS_SB(sb), USRQUOTA),
+		test_opt(F2FS_SB(sb), GRPQUOTA),
+		test_opt(F2FS_SB(sb), PRJQUOTA),
+	};
+
+	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE | DQUOT_NOLIST_DIRTY;
+	for (type = 0; type < MAXQUOTAS; type++) {
+		qf_inum = f2fs_qf_ino(sb, type);
+		if (qf_inum) {
+			err = f2fs_quota_enable(sb, type, QFMT_VFS_V1,
+				DQUOT_USAGE_ENABLED |
+				(quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
+			if (err) {
+				f2fs_msg(sb, KERN_ERR,
+					"Failed to enable quota tracking "
+					"(type=%d, err=%d). Please run "
+					"fsck to fix.", type, err);
+				for (type--; type >= 0; type--)
+					dquot_quota_off(sb, type);
+				return err;
+			}
+		}
+	}
+	return 0;
+}
+
+static int f2fs_quota_sync(struct super_block *sb, int type)
+{
+	struct quota_info *dqopt = sb_dqopt(sb);
+	int cnt;
+	int ret;
+
+	ret = dquot_writeback_dquots(sb, type);
+	if (ret)
+		return ret;
+
+	/*
+	 * Now when everything is written we can discard the pagecache so
+	 * that userspace sees the changes.
+	 */
+	for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+		if (type != -1 && cnt != type)
+			continue;
+		if (!sb_has_quota_active(sb, cnt))
+			continue;
+
+		ret = filemap_write_and_wait(dqopt->files[cnt]->i_mapping);
+		if (ret)
+			return ret;
+
+		inode_lock(dqopt->files[cnt]);
+		truncate_inode_pages(&dqopt->files[cnt]->i_data, 0);
+		inode_unlock(dqopt->files[cnt]);
+	}
+	return 0;
+}
+
+static int f2fs_quota_on(struct super_block *sb, int type, int format_id,
+							const struct path *path)
+{
+	struct inode *inode;
+	int err;
+
+	err = f2fs_quota_sync(sb, type);
+	if (err)
+		return err;
+
+	err = dquot_quota_on(sb, type, format_id, path);
+	if (err)
+		return err;
+
+	inode = d_inode(path->dentry);
+
+	inode_lock(inode);
+	F2FS_I(inode)->i_flags |= FS_NOATIME_FL | FS_IMMUTABLE_FL;
+	inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
+					S_NOATIME | S_IMMUTABLE);
+	inode_unlock(inode);
+	f2fs_mark_inode_dirty_sync(inode, false);
+
+	return 0;
+}
+
+static int f2fs_quota_off(struct super_block *sb, int type)
+{
+	struct inode *inode = sb_dqopt(sb)->files[type];
+	int err;
+
+	if (!inode || !igrab(inode))
+		return dquot_quota_off(sb, type);
+
+	err = f2fs_quota_sync(sb, type);
+	if (err)
+		goto out_put;
+
+	err = dquot_quota_off(sb, type);
+	if (err || f2fs_sb_has_quota_ino(sb))
+		goto out_put;
+
+	inode_lock(inode);
+	F2FS_I(inode)->i_flags &= ~(FS_NOATIME_FL | FS_IMMUTABLE_FL);
+	inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
+	inode_unlock(inode);
+	f2fs_mark_inode_dirty_sync(inode, false);
+out_put:
+	iput(inode);
+	return err;
+}
+
+void f2fs_quota_off_umount(struct super_block *sb)
+{
+	int type;
+	int err;
+
+	for (type = 0; type < MAXQUOTAS; type++) {
+		err = f2fs_quota_off(sb, type);
+		if (err) {
+			int ret = dquot_quota_off(sb, type);
+
+			f2fs_msg(sb, KERN_ERR,
+				"Fail to turn off disk quota "
+				"(type: %d, err: %d, ret:%d), Please "
+				"run fsck to fix it.", type, err, ret);
+			set_sbi_flag(F2FS_SB(sb), SBI_NEED_FSCK);
+		}
+	}
+	/*
+	 * In case of checkpoint=disable, we must flush quota blocks.
+	 * This can cause NULL exception for node_inode in end_io, since
+	 * put_super already dropped it.
+	 */
+	sync_filesystem(sb);
+}
+
+static int f2fs_get_projid(struct inode *inode, kprojid_t *projid)
+{
+	*projid = F2FS_I(inode)->i_projid;
+	return 0;
+}
+
+static const struct dquot_operations f2fs_quota_operations = {
+	.get_reserved_space = f2fs_get_reserved_space,
+	.write_dquot	= dquot_commit,
+	.acquire_dquot	= dquot_acquire,
+	.release_dquot	= dquot_release,
+	.mark_dirty	= dquot_mark_dquot_dirty,
+	.write_info	= dquot_commit_info,
+	.alloc_dquot	= dquot_alloc,
+	.destroy_dquot	= dquot_destroy,
+	.get_projid	= f2fs_get_projid,
+	.get_next_id	= dquot_get_next_id,
+};
+
+static const struct quotactl_ops f2fs_quotactl_ops = {
+	.quota_on	= f2fs_quota_on,
+	.quota_off	= f2fs_quota_off,
+	.quota_sync	= f2fs_quota_sync,
+	.get_state	= dquot_get_state,
+	.set_info	= dquot_set_dqinfo,
+	.get_dqblk	= dquot_get_dqblk,
+	.set_dqblk	= dquot_set_dqblk,
+	.get_nextdqblk	= dquot_get_next_dqblk,
+};
+#else
+void f2fs_quota_off_umount(struct super_block *sb)
+{
+}
+#endif
+
+static const struct super_operations f2fs_sops = {
+	.alloc_inode	= f2fs_alloc_inode,
+	.drop_inode	= f2fs_drop_inode,
+	.destroy_inode	= f2fs_destroy_inode,
+	.write_inode	= f2fs_write_inode,
+	.dirty_inode	= f2fs_dirty_inode,
+	.show_options	= f2fs_show_options,
+#ifdef CONFIG_QUOTA
+	.quota_read	= f2fs_quota_read,
+	.quota_write	= f2fs_quota_write,
+	.get_dquots	= f2fs_get_dquots,
+#endif
+	.evict_inode	= f2fs_evict_inode,
+	.put_super	= f2fs_put_super,
+	.sync_fs	= f2fs_sync_fs,
+	.freeze_fs	= f2fs_freeze,
+	.unfreeze_fs	= f2fs_unfreeze,
+	.statfs		= f2fs_statfs,
+	.remount_fs	= f2fs_remount,
+};
+
+#ifdef CONFIG_F2FS_FS_ENCRYPTION
+static int f2fs_get_context(struct inode *inode, void *ctx, size_t len)
+{
+	return f2fs_getxattr(inode, F2FS_XATTR_INDEX_ENCRYPTION,
+				F2FS_XATTR_NAME_ENCRYPTION_CONTEXT,
+				ctx, len, NULL);
+}
+
+static int f2fs_set_context(struct inode *inode, const void *ctx, size_t len,
+							void *fs_data)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+
+	/*
+	 * Encrypting the root directory is not allowed because fsck
+	 * expects lost+found directory to exist and remain unencrypted
+	 * if LOST_FOUND feature is enabled.
+	 *
+	 */
+	if (f2fs_sb_has_lost_found(sbi->sb) &&
+			inode->i_ino == F2FS_ROOT_INO(sbi))
+		return -EPERM;
+
+	return f2fs_setxattr(inode, F2FS_XATTR_INDEX_ENCRYPTION,
+				F2FS_XATTR_NAME_ENCRYPTION_CONTEXT,
+				ctx, len, fs_data, XATTR_CREATE);
+}
+
+static bool f2fs_dummy_context(struct inode *inode)
+{
+	return DUMMY_ENCRYPTION_ENABLED(F2FS_I_SB(inode));
+}
+
+static unsigned f2fs_max_namelen(struct inode *inode)
+{
+	return S_ISLNK(inode->i_mode) ?
+			inode->i_sb->s_blocksize : F2FS_NAME_LEN;
+}
+
+static const struct fscrypt_operations f2fs_cryptops = {
+	.key_prefix	= "f2fs:",
+	.get_context	= f2fs_get_context,
+	.set_context	= f2fs_set_context,
+	.dummy_context	= f2fs_dummy_context,
+	.empty_dir	= f2fs_empty_dir,
+	.max_namelen	= f2fs_max_namelen,
+};
+#endif
+
+static struct inode *f2fs_nfs_get_inode(struct super_block *sb,
+		u64 ino, u32 generation)
+{
+	struct f2fs_sb_info *sbi = F2FS_SB(sb);
+	struct inode *inode;
+
+	if (check_nid_range(sbi, ino))
+		return ERR_PTR(-ESTALE);
+
+	/*
+	 * f2fs_iget isn't quite right if the inode is currently unallocated!
+	 * However f2fs_iget currently does appropriate checks to handle stale
+	 * inodes so everything is OK.
+	 */
+	inode = f2fs_iget(sb, ino);
+	if (IS_ERR(inode))
+		return ERR_CAST(inode);
+	if (unlikely(generation && inode->i_generation != generation)) {
+		/* we didn't find the right inode.. */
+		iput(inode);
+		return ERR_PTR(-ESTALE);
+	}
+	return inode;
+}
+
+static struct dentry *f2fs_fh_to_dentry(struct super_block *sb, struct fid *fid,
+		int fh_len, int fh_type)
+{
+	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
+				    f2fs_nfs_get_inode);
+}
+
+static struct dentry *f2fs_fh_to_parent(struct super_block *sb, struct fid *fid,
+		int fh_len, int fh_type)
+{
+	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
+				    f2fs_nfs_get_inode);
+}
+
+static const struct export_operations f2fs_export_ops = {
+	.fh_to_dentry = f2fs_fh_to_dentry,
+	.fh_to_parent = f2fs_fh_to_parent,
+	.get_parent = f2fs_get_parent,
+};
+
+static loff_t max_file_blocks(void)
+{
+	loff_t result = 0;
+	loff_t leaf_count = ADDRS_PER_BLOCK;
+
+	/*
+	 * note: previously, result is equal to (DEF_ADDRS_PER_INODE -
+	 * DEFAULT_INLINE_XATTR_ADDRS), but now f2fs try to reserve more
+	 * space in inode.i_addr, it will be more safe to reassign
+	 * result as zero.
+	 */
+
+	/* two direct node blocks */
+	result += (leaf_count * 2);
+
+	/* two indirect node blocks */
+	leaf_count *= NIDS_PER_BLOCK;
+	result += (leaf_count * 2);
+
+	/* one double indirect node block */
+	leaf_count *= NIDS_PER_BLOCK;
+	result += leaf_count;
+
+	return result;
+}
+
+static int __f2fs_commit_super(struct buffer_head *bh,
+			struct f2fs_super_block *super)
+{
+	lock_buffer(bh);
+	if (super)
+		memcpy(bh->b_data + F2FS_SUPER_OFFSET, super, sizeof(*super));
+	set_buffer_dirty(bh);
+	unlock_buffer(bh);
+
+	/* it's rare case, we can do fua all the time */
+	return __sync_dirty_buffer(bh, REQ_SYNC | REQ_PREFLUSH | REQ_FUA);
+}
+
+static inline bool sanity_check_area_boundary(struct f2fs_sb_info *sbi,
+					struct buffer_head *bh)
+{
+	struct f2fs_super_block *raw_super = (struct f2fs_super_block *)
+					(bh->b_data + F2FS_SUPER_OFFSET);
+	struct super_block *sb = sbi->sb;
+	u32 segment0_blkaddr = le32_to_cpu(raw_super->segment0_blkaddr);
+	u32 cp_blkaddr = le32_to_cpu(raw_super->cp_blkaddr);
+	u32 sit_blkaddr = le32_to_cpu(raw_super->sit_blkaddr);
+	u32 nat_blkaddr = le32_to_cpu(raw_super->nat_blkaddr);
+	u32 ssa_blkaddr = le32_to_cpu(raw_super->ssa_blkaddr);
+	u32 main_blkaddr = le32_to_cpu(raw_super->main_blkaddr);
+	u32 segment_count_ckpt = le32_to_cpu(raw_super->segment_count_ckpt);
+	u32 segment_count_sit = le32_to_cpu(raw_super->segment_count_sit);
+	u32 segment_count_nat = le32_to_cpu(raw_super->segment_count_nat);
+	u32 segment_count_ssa = le32_to_cpu(raw_super->segment_count_ssa);
+	u32 segment_count_main = le32_to_cpu(raw_super->segment_count_main);
+	u32 segment_count = le32_to_cpu(raw_super->segment_count);
+	u32 log_blocks_per_seg = le32_to_cpu(raw_super->log_blocks_per_seg);
+	u64 main_end_blkaddr = main_blkaddr +
+				(segment_count_main << log_blocks_per_seg);
+	u64 seg_end_blkaddr = segment0_blkaddr +
+				(segment_count << log_blocks_per_seg);
+
+	if (segment0_blkaddr != cp_blkaddr) {
+		f2fs_msg(sb, KERN_INFO,
+			"Mismatch start address, segment0(%u) cp_blkaddr(%u)",
+			segment0_blkaddr, cp_blkaddr);
+		return true;
+	}
+
+	if (cp_blkaddr + (segment_count_ckpt << log_blocks_per_seg) !=
+							sit_blkaddr) {
+		f2fs_msg(sb, KERN_INFO,
+			"Wrong CP boundary, start(%u) end(%u) blocks(%u)",
+			cp_blkaddr, sit_blkaddr,
+			segment_count_ckpt << log_blocks_per_seg);
+		return true;
+	}
+
+	if (sit_blkaddr + (segment_count_sit << log_blocks_per_seg) !=
+							nat_blkaddr) {
+		f2fs_msg(sb, KERN_INFO,
+			"Wrong SIT boundary, start(%u) end(%u) blocks(%u)",
+			sit_blkaddr, nat_blkaddr,
+			segment_count_sit << log_blocks_per_seg);
+		return true;
+	}
+
+	if (nat_blkaddr + (segment_count_nat << log_blocks_per_seg) !=
+							ssa_blkaddr) {
+		f2fs_msg(sb, KERN_INFO,
+			"Wrong NAT boundary, start(%u) end(%u) blocks(%u)",
+			nat_blkaddr, ssa_blkaddr,
+			segment_count_nat << log_blocks_per_seg);
+		return true;
+	}
+
+	if (ssa_blkaddr + (segment_count_ssa << log_blocks_per_seg) !=
+							main_blkaddr) {
+		f2fs_msg(sb, KERN_INFO,
+			"Wrong SSA boundary, start(%u) end(%u) blocks(%u)",
+			ssa_blkaddr, main_blkaddr,
+			segment_count_ssa << log_blocks_per_seg);
+		return true;
+	}
+
+	if (main_end_blkaddr > seg_end_blkaddr) {
+		f2fs_msg(sb, KERN_INFO,
+			"Wrong MAIN_AREA boundary, start(%u) end(%u) block(%u)",
+			main_blkaddr,
+			segment0_blkaddr +
+				(segment_count << log_blocks_per_seg),
+			segment_count_main << log_blocks_per_seg);
+		return true;
+	} else if (main_end_blkaddr < seg_end_blkaddr) {
+		int err = 0;
+		char *res;
+
+		/* fix in-memory information all the time */
+		raw_super->segment_count = cpu_to_le32((main_end_blkaddr -
+				segment0_blkaddr) >> log_blocks_per_seg);
+
+		if (f2fs_readonly(sb) || bdev_read_only(sb->s_bdev)) {
+			set_sbi_flag(sbi, SBI_NEED_SB_WRITE);
+			res = "internally";
+		} else {
+			err = __f2fs_commit_super(bh, NULL);
+			res = err ? "failed" : "done";
+		}
+		f2fs_msg(sb, KERN_INFO,
+			"Fix alignment : %s, start(%u) end(%u) block(%u)",
+			res, main_blkaddr,
+			segment0_blkaddr +
+				(segment_count << log_blocks_per_seg),
+			segment_count_main << log_blocks_per_seg);
+		if (err)
+			return true;
+	}
+	return false;
+}
+
+static int sanity_check_raw_super(struct f2fs_sb_info *sbi,
+				struct buffer_head *bh)
+{
+	block_t segment_count, segs_per_sec, secs_per_zone;
+	block_t total_sections, blocks_per_seg;
+	struct f2fs_super_block *raw_super = (struct f2fs_super_block *)
+					(bh->b_data + F2FS_SUPER_OFFSET);
+	struct super_block *sb = sbi->sb;
+	unsigned int blocksize;
+
+	if (le32_to_cpu(raw_super->magic) != F2FS_SUPER_MAGIC) {
+		f2fs_msg(sb, KERN_INFO,
+			"Magic Mismatch, valid(0x%x) - read(0x%x)",
+			F2FS_SUPER_MAGIC, le32_to_cpu(raw_super->magic));
+		return -EINVAL;
+	}
+
+	/* Currently, support only 4KB page cache size */
+	if (F2FS_BLKSIZE != PAGE_SIZE) {
+		f2fs_msg(sb, KERN_INFO,
+			"Invalid page_cache_size (%lu), supports only 4KB\n",
+			PAGE_SIZE);
+		return -EFSCORRUPTED;
+	}
+
+	/* Currently, support only 4KB block size */
+	blocksize = 1 << le32_to_cpu(raw_super->log_blocksize);
+	if (blocksize != F2FS_BLKSIZE) {
+		f2fs_msg(sb, KERN_INFO,
+			"Invalid blocksize (%u), supports only 4KB\n",
+			blocksize);
+		return -EFSCORRUPTED;
+	}
+
+	/* check log blocks per segment */
+	if (le32_to_cpu(raw_super->log_blocks_per_seg) != 9) {
+		f2fs_msg(sb, KERN_INFO,
+			"Invalid log blocks per segment (%u)\n",
+			le32_to_cpu(raw_super->log_blocks_per_seg));
+		return -EFSCORRUPTED;
+	}
+
+	/* Currently, support 512/1024/2048/4096 bytes sector size */
+	if (le32_to_cpu(raw_super->log_sectorsize) >
+				F2FS_MAX_LOG_SECTOR_SIZE ||
+		le32_to_cpu(raw_super->log_sectorsize) <
+				F2FS_MIN_LOG_SECTOR_SIZE) {
+		f2fs_msg(sb, KERN_INFO, "Invalid log sectorsize (%u)",
+			le32_to_cpu(raw_super->log_sectorsize));
+		return -EFSCORRUPTED;
+	}
+	if (le32_to_cpu(raw_super->log_sectors_per_block) +
+		le32_to_cpu(raw_super->log_sectorsize) !=
+			F2FS_MAX_LOG_SECTOR_SIZE) {
+		f2fs_msg(sb, KERN_INFO,
+			"Invalid log sectors per block(%u) log sectorsize(%u)",
+			le32_to_cpu(raw_super->log_sectors_per_block),
+			le32_to_cpu(raw_super->log_sectorsize));
+		return -EFSCORRUPTED;
+	}
+
+	segment_count = le32_to_cpu(raw_super->segment_count);
+	segs_per_sec = le32_to_cpu(raw_super->segs_per_sec);
+	secs_per_zone = le32_to_cpu(raw_super->secs_per_zone);
+	total_sections = le32_to_cpu(raw_super->section_count);
+
+	/* blocks_per_seg should be 512, given the above check */
+	blocks_per_seg = 1 << le32_to_cpu(raw_super->log_blocks_per_seg);
+
+	if (segment_count > F2FS_MAX_SEGMENT ||
+				segment_count < F2FS_MIN_SEGMENTS) {
+		f2fs_msg(sb, KERN_INFO,
+			"Invalid segment count (%u)",
+			segment_count);
+		return -EFSCORRUPTED;
+	}
+
+	if (total_sections > segment_count ||
+			total_sections < F2FS_MIN_SEGMENTS ||
+			segs_per_sec > segment_count || !segs_per_sec) {
+		f2fs_msg(sb, KERN_INFO,
+			"Invalid segment/section count (%u, %u x %u)",
+			segment_count, total_sections, segs_per_sec);
+		return -EFSCORRUPTED;
+	}
+
+	if ((segment_count / segs_per_sec) < total_sections) {
+		f2fs_msg(sb, KERN_INFO,
+			"Small segment_count (%u < %u * %u)",
+			segment_count, segs_per_sec, total_sections);
+		return -EFSCORRUPTED;
+	}
+
+	if (segment_count > (le64_to_cpu(raw_super->block_count) >> 9)) {
+		f2fs_msg(sb, KERN_INFO,
+			"Wrong segment_count / block_count (%u > %llu)",
+			segment_count, le64_to_cpu(raw_super->block_count));
+		return -EFSCORRUPTED;
+	}
+
+	if (secs_per_zone > total_sections || !secs_per_zone) {
+		f2fs_msg(sb, KERN_INFO,
+			"Wrong secs_per_zone / total_sections (%u, %u)",
+			secs_per_zone, total_sections);
+		return -EFSCORRUPTED;
+	}
+	if (le32_to_cpu(raw_super->extension_count) > F2FS_MAX_EXTENSION) {
+		f2fs_msg(sb, KERN_INFO,
+			"Corrupted extension count (%u > %u)",
+			le32_to_cpu(raw_super->extension_count),
+			F2FS_MAX_EXTENSION);
+		return -EFSCORRUPTED;
+	}
+
+	if (le32_to_cpu(raw_super->cp_payload) >
+				(blocks_per_seg - F2FS_CP_PACKS)) {
+		f2fs_msg(sb, KERN_INFO,
+			"Insane cp_payload (%u > %u)",
+			le32_to_cpu(raw_super->cp_payload),
+			blocks_per_seg - F2FS_CP_PACKS);
+		return -EFSCORRUPTED;
+	}
+
+	/* check reserved ino info */
+	if (le32_to_cpu(raw_super->node_ino) != 1 ||
+		le32_to_cpu(raw_super->meta_ino) != 2 ||
+		le32_to_cpu(raw_super->root_ino) != 3) {
+		f2fs_msg(sb, KERN_INFO,
+			"Invalid Fs Meta Ino: node(%u) meta(%u) root(%u)",
+			le32_to_cpu(raw_super->node_ino),
+			le32_to_cpu(raw_super->meta_ino),
+			le32_to_cpu(raw_super->root_ino));
+		return -EFSCORRUPTED;
+	}
+
+	/* check CP/SIT/NAT/SSA/MAIN_AREA area boundary */
+	if (sanity_check_area_boundary(sbi, bh))
+		return -EFSCORRUPTED;
+
+	return 0;
+}
+
+int sanity_check_ckpt(struct f2fs_sb_info *sbi)
+{
+	unsigned int total, fsmeta;
+	struct f2fs_super_block *raw_super = F2FS_RAW_SUPER(sbi);
+	struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
+	unsigned int ovp_segments, reserved_segments;
+	unsigned int main_segs, blocks_per_seg;
+	unsigned int sit_segs, nat_segs;
+	unsigned int sit_bitmap_size, nat_bitmap_size;
+	unsigned int log_blocks_per_seg;
+	unsigned int segment_count_main;
+	unsigned int cp_pack_start_sum, cp_payload;
+	block_t user_block_count;
+	int i, j;
+
+	total = le32_to_cpu(raw_super->segment_count);
+	fsmeta = le32_to_cpu(raw_super->segment_count_ckpt);
+	sit_segs = le32_to_cpu(raw_super->segment_count_sit);
+	fsmeta += sit_segs;
+	nat_segs = le32_to_cpu(raw_super->segment_count_nat);
+	fsmeta += nat_segs;
+	fsmeta += le32_to_cpu(ckpt->rsvd_segment_count);
+	fsmeta += le32_to_cpu(raw_super->segment_count_ssa);
+
+	if (unlikely(fsmeta >= total))
+		return 1;
+
+	ovp_segments = le32_to_cpu(ckpt->overprov_segment_count);
+	reserved_segments = le32_to_cpu(ckpt->rsvd_segment_count);
+
+	if (unlikely(fsmeta < F2FS_MIN_SEGMENTS ||
+			ovp_segments == 0 || reserved_segments == 0)) {
+		f2fs_msg(sbi->sb, KERN_ERR,
+			"Wrong layout: check mkfs.f2fs version");
+		return 1;
+	}
+
+	user_block_count = le64_to_cpu(ckpt->user_block_count);
+	segment_count_main = le32_to_cpu(raw_super->segment_count_main);
+	log_blocks_per_seg = le32_to_cpu(raw_super->log_blocks_per_seg);
+	if (!user_block_count || user_block_count >=
+			segment_count_main << log_blocks_per_seg) {
+		f2fs_msg(sbi->sb, KERN_ERR,
+			"Wrong user_block_count: %u", user_block_count);
+		return 1;
+	}
+
+	main_segs = le32_to_cpu(raw_super->segment_count_main);
+	blocks_per_seg = sbi->blocks_per_seg;
+
+	for (i = 0; i < NR_CURSEG_NODE_TYPE; i++) {
+		if (le32_to_cpu(ckpt->cur_node_segno[i]) >= main_segs ||
+			le16_to_cpu(ckpt->cur_node_blkoff[i]) >= blocks_per_seg)
+			return 1;
+		for (j = i + 1; j < NR_CURSEG_NODE_TYPE; j++) {
+			if (le32_to_cpu(ckpt->cur_node_segno[i]) ==
+				le32_to_cpu(ckpt->cur_node_segno[j])) {
+				f2fs_msg(sbi->sb, KERN_ERR,
+					"Node segment (%u, %u) has the same "
+					"segno: %u", i, j,
+					le32_to_cpu(ckpt->cur_node_segno[i]));
+				return 1;
+			}
+		}
+	}
+	for (i = 0; i < NR_CURSEG_DATA_TYPE; i++) {
+		if (le32_to_cpu(ckpt->cur_data_segno[i]) >= main_segs ||
+			le16_to_cpu(ckpt->cur_data_blkoff[i]) >= blocks_per_seg)
+			return 1;
+		for (j = i + 1; j < NR_CURSEG_DATA_TYPE; j++) {
+			if (le32_to_cpu(ckpt->cur_data_segno[i]) ==
+				le32_to_cpu(ckpt->cur_data_segno[j])) {
+				f2fs_msg(sbi->sb, KERN_ERR,
+					"Data segment (%u, %u) has the same "
+					"segno: %u", i, j,
+					le32_to_cpu(ckpt->cur_data_segno[i]));
+				return 1;
+			}
+		}
+	}
+	for (i = 0; i < NR_CURSEG_NODE_TYPE; i++) {
+		for (j = 0; j < NR_CURSEG_DATA_TYPE; j++) {
+			if (le32_to_cpu(ckpt->cur_node_segno[i]) ==
+				le32_to_cpu(ckpt->cur_data_segno[j])) {
+				f2fs_msg(sbi->sb, KERN_ERR,
+					"Node segment (%u) and Data segment (%u)"
+					" has the same segno: %u", i, j,
+					le32_to_cpu(ckpt->cur_node_segno[i]));
+				return 1;
+			}
+		}
+	}
+
+	sit_bitmap_size = le32_to_cpu(ckpt->sit_ver_bitmap_bytesize);
+	nat_bitmap_size = le32_to_cpu(ckpt->nat_ver_bitmap_bytesize);
+
+	if (sit_bitmap_size != ((sit_segs / 2) << log_blocks_per_seg) / 8 ||
+		nat_bitmap_size != ((nat_segs / 2) << log_blocks_per_seg) / 8) {
+		f2fs_msg(sbi->sb, KERN_ERR,
+			"Wrong bitmap size: sit: %u, nat:%u",
+			sit_bitmap_size, nat_bitmap_size);
+		return 1;
+	}
+
+	cp_pack_start_sum = __start_sum_addr(sbi);
+	cp_payload = __cp_payload(sbi);
+	if (cp_pack_start_sum < cp_payload + 1 ||
+		cp_pack_start_sum > blocks_per_seg - 1 -
+			NR_CURSEG_TYPE) {
+		f2fs_msg(sbi->sb, KERN_ERR,
+			"Wrong cp_pack_start_sum: %u",
+			cp_pack_start_sum);
+		return 1;
+	}
+
+	if (unlikely(f2fs_cp_error(sbi))) {
+		f2fs_msg(sbi->sb, KERN_ERR, "A bug case: need to run fsck");
+		return 1;
+	}
+	return 0;
+}
+
+static void init_sb_info(struct f2fs_sb_info *sbi)
+{
+	struct f2fs_super_block *raw_super = sbi->raw_super;
+	int i, j;
+
+	sbi->log_sectors_per_block =
+		le32_to_cpu(raw_super->log_sectors_per_block);
+	sbi->log_blocksize = le32_to_cpu(raw_super->log_blocksize);
+	sbi->blocksize = 1 << sbi->log_blocksize;
+	sbi->log_blocks_per_seg = le32_to_cpu(raw_super->log_blocks_per_seg);
+	sbi->blocks_per_seg = 1 << sbi->log_blocks_per_seg;
+	sbi->segs_per_sec = le32_to_cpu(raw_super->segs_per_sec);
+	sbi->secs_per_zone = le32_to_cpu(raw_super->secs_per_zone);
+	sbi->total_sections = le32_to_cpu(raw_super->section_count);
+	sbi->total_node_count =
+		(le32_to_cpu(raw_super->segment_count_nat) / 2)
+			* sbi->blocks_per_seg * NAT_ENTRY_PER_BLOCK;
+	sbi->root_ino_num = le32_to_cpu(raw_super->root_ino);
+	sbi->node_ino_num = le32_to_cpu(raw_super->node_ino);
+	sbi->meta_ino_num = le32_to_cpu(raw_super->meta_ino);
+	sbi->cur_victim_sec = NULL_SECNO;
+	sbi->max_victim_search = DEF_MAX_VICTIM_SEARCH;
+
+	sbi->dir_level = DEF_DIR_LEVEL;
+	sbi->interval_time[CP_TIME] = DEF_CP_INTERVAL;
+	sbi->interval_time[REQ_TIME] = DEF_IDLE_INTERVAL;
+	clear_sbi_flag(sbi, SBI_NEED_FSCK);
+
+	for (i = 0; i < NR_COUNT_TYPE; i++)
+		atomic_set(&sbi->nr_pages[i], 0);
+
+	atomic_set(&sbi->wb_sync_req, 0);
+
+	INIT_LIST_HEAD(&sbi->s_list);
+	mutex_init(&sbi->umount_mutex);
+	for (i = 0; i < NR_PAGE_TYPE - 1; i++)
+		for (j = HOT; j < NR_TEMP_TYPE; j++)
+			mutex_init(&sbi->wio_mutex[i][j]);
+	spin_lock_init(&sbi->cp_lock);
+
+	sbi->dirty_device = 0;
+	spin_lock_init(&sbi->dev_lock);
+
+	init_rwsem(&sbi->sb_lock);
+}
+
+static int init_percpu_info(struct f2fs_sb_info *sbi)
+{
+	int err;
+
+	err = percpu_counter_init(&sbi->alloc_valid_block_count, 0, GFP_KERNEL);
+	if (err)
+		return err;
+
+	err = percpu_counter_init(&sbi->total_valid_inode_count, 0,
+								GFP_KERNEL);
+	if (err)
+		percpu_counter_destroy(&sbi->alloc_valid_block_count);
+
+	return err;
+}
+
+#ifdef CONFIG_BLK_DEV_ZONED
+static int init_blkz_info(struct f2fs_sb_info *sbi, int devi)
+{
+	struct block_device *bdev = FDEV(devi).bdev;
+	sector_t nr_sectors = bdev->bd_part->nr_sects;
+	sector_t sector = 0;
+	struct blk_zone *zones;
+	unsigned int i, nr_zones;
+	unsigned int n = 0;
+	int err = -EIO;
+
+	if (!f2fs_sb_has_blkzoned(sbi->sb))
+		return 0;
+
+	if (sbi->blocks_per_blkz && sbi->blocks_per_blkz !=
+				SECTOR_TO_BLOCK(bdev_zone_sectors(bdev)))
+		return -EINVAL;
+	sbi->blocks_per_blkz = SECTOR_TO_BLOCK(bdev_zone_sectors(bdev));
+	if (sbi->log_blocks_per_blkz && sbi->log_blocks_per_blkz !=
+				__ilog2_u32(sbi->blocks_per_blkz))
+		return -EINVAL;
+	sbi->log_blocks_per_blkz = __ilog2_u32(sbi->blocks_per_blkz);
+	FDEV(devi).nr_blkz = SECTOR_TO_BLOCK(nr_sectors) >>
+					sbi->log_blocks_per_blkz;
+	if (nr_sectors & (bdev_zone_sectors(bdev) - 1))
+		FDEV(devi).nr_blkz++;
+
+	FDEV(devi).blkz_type = f2fs_kmalloc(sbi, FDEV(devi).nr_blkz,
+								GFP_KERNEL);
+	if (!FDEV(devi).blkz_type)
+		return -ENOMEM;
+
+#define F2FS_REPORT_NR_ZONES   4096
+
+	zones = f2fs_kzalloc(sbi, sizeof(struct blk_zone) *
+				F2FS_REPORT_NR_ZONES, GFP_KERNEL);
+	if (!zones)
+		return -ENOMEM;
+
+	/* Get block zones type */
+	while (zones && sector < nr_sectors) {
+
+		nr_zones = F2FS_REPORT_NR_ZONES;
+		err = blkdev_report_zones(bdev, sector,
+					  zones, &nr_zones,
+					  GFP_KERNEL);
+		if (err)
+			break;
+		if (!nr_zones) {
+			err = -EIO;
+			break;
+		}
+
+		for (i = 0; i < nr_zones; i++) {
+			FDEV(devi).blkz_type[n] = zones[i].type;
+			sector += zones[i].len;
+			n++;
+		}
+	}
+
+	kfree(zones);
+
+	return err;
+}
+#endif
+
+/*
+ * Read f2fs raw super block.
+ * Because we have two copies of super block, so read both of them
+ * to get the first valid one. If any one of them is broken, we pass
+ * them recovery flag back to the caller.
+ */
+static int read_raw_super_block(struct f2fs_sb_info *sbi,
+			struct f2fs_super_block **raw_super,
+			int *valid_super_block, int *recovery)
+{
+	struct super_block *sb = sbi->sb;
+	int block;
+	struct buffer_head *bh;
+	struct f2fs_super_block *super;
+	int err = 0;
+
+	super = kzalloc(sizeof(struct f2fs_super_block), GFP_KERNEL);
+	if (!super)
+		return -ENOMEM;
+
+	for (block = 0; block < 2; block++) {
+		bh = sb_bread(sb, block);
+		if (!bh) {
+			f2fs_msg(sb, KERN_ERR, "Unable to read %dth superblock",
+				block + 1);
+			err = -EIO;
+			continue;
+		}
+
+		/* sanity checking of raw super */
+		err = sanity_check_raw_super(sbi, bh);
+		if (err) {
+			f2fs_msg(sb, KERN_ERR,
+				"Can't find valid F2FS filesystem in %dth superblock",
+				block + 1);
+			brelse(bh);
+			continue;
+		}
+
+		if (!*raw_super) {
+			memcpy(super, bh->b_data + F2FS_SUPER_OFFSET,
+							sizeof(*super));
+			*valid_super_block = block;
+			*raw_super = super;
+		}
+		brelse(bh);
+	}
+
+	/* Fail to read any one of the superblocks*/
+	if (err < 0)
+		*recovery = 1;
+
+	/* No valid superblock */
+	if (!*raw_super)
+		kfree(super);
+	else
+		err = 0;
+
+	return err;
+}
+
+int f2fs_commit_super(struct f2fs_sb_info *sbi, bool recover)
+{
+	struct buffer_head *bh;
+	int err;
+
+	if ((recover && f2fs_readonly(sbi->sb)) ||
+				bdev_read_only(sbi->sb->s_bdev)) {
+		set_sbi_flag(sbi, SBI_NEED_SB_WRITE);
+		return -EROFS;
+	}
+
+	/* write back-up superblock first */
+	bh = sb_bread(sbi->sb, sbi->valid_super_block ? 0 : 1);
+	if (!bh)
+		return -EIO;
+	err = __f2fs_commit_super(bh, F2FS_RAW_SUPER(sbi));
+	brelse(bh);
+
+	/* if we are in recovery path, skip writing valid superblock */
+	if (recover || err)
+		return err;
+
+	/* write current valid superblock */
+	bh = sb_bread(sbi->sb, sbi->valid_super_block);
+	if (!bh)
+		return -EIO;
+	err = __f2fs_commit_super(bh, F2FS_RAW_SUPER(sbi));
+	brelse(bh);
+	return err;
+}
+
+static int f2fs_scan_devices(struct f2fs_sb_info *sbi)
+{
+	struct f2fs_super_block *raw_super = F2FS_RAW_SUPER(sbi);
+	unsigned int max_devices = MAX_DEVICES;
+	int i;
+
+	/* Initialize single device information */
+	if (!RDEV(0).path[0]) {
+		if (!bdev_is_zoned(sbi->sb->s_bdev))
+			return 0;
+		max_devices = 1;
+	}
+
+	/*
+	 * Initialize multiple devices information, or single
+	 * zoned block device information.
+	 */
+	sbi->devs = f2fs_kzalloc(sbi, sizeof(struct f2fs_dev_info) *
+						max_devices, GFP_KERNEL);
+	if (!sbi->devs)
+		return -ENOMEM;
+
+	for (i = 0; i < max_devices; i++) {
+
+		if (i > 0 && !RDEV(i).path[0])
+			break;
+
+		if (max_devices == 1) {
+			/* Single zoned block device mount */
+			FDEV(0).bdev =
+				blkdev_get_by_dev(sbi->sb->s_bdev->bd_dev,
+					sbi->sb->s_mode, sbi->sb->s_type);
+		} else {
+			/* Multi-device mount */
+			memcpy(FDEV(i).path, RDEV(i).path, MAX_PATH_LEN);
+			FDEV(i).total_segments =
+				le32_to_cpu(RDEV(i).total_segments);
+			if (i == 0) {
+				FDEV(i).start_blk = 0;
+				FDEV(i).end_blk = FDEV(i).start_blk +
+				    (FDEV(i).total_segments <<
+				    sbi->log_blocks_per_seg) - 1 +
+				    le32_to_cpu(raw_super->segment0_blkaddr);
+			} else {
+				FDEV(i).start_blk = FDEV(i - 1).end_blk + 1;
+				FDEV(i).end_blk = FDEV(i).start_blk +
+					(FDEV(i).total_segments <<
+					sbi->log_blocks_per_seg) - 1;
+			}
+			FDEV(i).bdev = blkdev_get_by_path(FDEV(i).path,
+					sbi->sb->s_mode, sbi->sb->s_type);
+		}
+		if (IS_ERR(FDEV(i).bdev))
+			return PTR_ERR(FDEV(i).bdev);
+
+		/* to release errored devices */
+		sbi->s_ndevs = i + 1;
+
+#ifdef CONFIG_BLK_DEV_ZONED
+		if (bdev_zoned_model(FDEV(i).bdev) == BLK_ZONED_HM &&
+				!f2fs_sb_has_blkzoned(sbi->sb)) {
+			f2fs_msg(sbi->sb, KERN_ERR,
+				"Zoned block device feature not enabled\n");
+			return -EINVAL;
+		}
+		if (bdev_zoned_model(FDEV(i).bdev) != BLK_ZONED_NONE) {
+			if (init_blkz_info(sbi, i)) {
+				f2fs_msg(sbi->sb, KERN_ERR,
+					"Failed to initialize F2FS blkzone information");
+				return -EINVAL;
+			}
+			if (max_devices == 1)
+				break;
+			f2fs_msg(sbi->sb, KERN_INFO,
+				"Mount Device [%2d]: %20s, %8u, %8x - %8x (zone: %s)",
+				i, FDEV(i).path,
+				FDEV(i).total_segments,
+				FDEV(i).start_blk, FDEV(i).end_blk,
+				bdev_zoned_model(FDEV(i).bdev) == BLK_ZONED_HA ?
+				"Host-aware" : "Host-managed");
+			continue;
+		}
+#endif
+		f2fs_msg(sbi->sb, KERN_INFO,
+			"Mount Device [%2d]: %20s, %8u, %8x - %8x",
+				i, FDEV(i).path,
+				FDEV(i).total_segments,
+				FDEV(i).start_blk, FDEV(i).end_blk);
+	}
+	f2fs_msg(sbi->sb, KERN_INFO,
+			"IO Block Size: %8d KB", F2FS_IO_SIZE_KB(sbi));
+	return 0;
+}
+
+static void f2fs_tuning_parameters(struct f2fs_sb_info *sbi)
+{
+	struct f2fs_sm_info *sm_i = SM_I(sbi);
+
+	/* adjust parameters according to the volume size */
+	if (sm_i->main_segments <= SMALL_VOLUME_SEGMENTS) {
+		F2FS_OPTION(sbi).alloc_mode = ALLOC_MODE_REUSE;
+		sm_i->dcc_info->discard_granularity = 1;
+		sm_i->ipu_policy = 1 << F2FS_IPU_FORCE;
+	}
+}
+
+static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
+{
+	struct f2fs_sb_info *sbi;
+	struct f2fs_super_block *raw_super;
+	struct inode *root;
+	int err;
+	bool retry = true, need_fsck = false;
+	char *options = NULL;
+	int recovery, i, valid_super_block;
+	struct curseg_info *seg_i;
+
+try_onemore:
+	err = -EINVAL;
+	raw_super = NULL;
+	valid_super_block = -1;
+	recovery = 0;
+
+	/* allocate memory for f2fs-specific super block info */
+	sbi = kzalloc(sizeof(struct f2fs_sb_info), GFP_KERNEL);
+	if (!sbi)
+		return -ENOMEM;
+
+	sbi->sb = sb;
+
+	/* Load the checksum driver */
+	sbi->s_chksum_driver = crypto_alloc_shash("crc32", 0, 0);
+	if (IS_ERR(sbi->s_chksum_driver)) {
+		f2fs_msg(sb, KERN_ERR, "Cannot load crc32 driver.");
+		err = PTR_ERR(sbi->s_chksum_driver);
+		sbi->s_chksum_driver = NULL;
+		goto free_sbi;
+	}
+
+	/* set a block size */
+	if (unlikely(!sb_set_blocksize(sb, F2FS_BLKSIZE))) {
+		f2fs_msg(sb, KERN_ERR, "unable to set blocksize");
+		goto free_sbi;
+	}
+
+	err = read_raw_super_block(sbi, &raw_super, &valid_super_block,
+								&recovery);
+	if (err)
+		goto free_sbi;
+
+	sb->s_fs_info = sbi;
+	sbi->raw_super = raw_super;
+
+	F2FS_OPTION(sbi).s_resuid = make_kuid(&init_user_ns, F2FS_DEF_RESUID);
+	F2FS_OPTION(sbi).s_resgid = make_kgid(&init_user_ns, F2FS_DEF_RESGID);
+
+	/* precompute checksum seed for metadata */
+	if (f2fs_sb_has_inode_chksum(sb))
+		sbi->s_chksum_seed = f2fs_chksum(sbi, ~0, raw_super->uuid,
+						sizeof(raw_super->uuid));
+
+	/*
+	 * The BLKZONED feature indicates that the drive was formatted with
+	 * zone alignment optimization. This is optional for host-aware
+	 * devices, but mandatory for host-managed zoned block devices.
+	 */
+#ifndef CONFIG_BLK_DEV_ZONED
+	if (f2fs_sb_has_blkzoned(sb)) {
+		f2fs_msg(sb, KERN_ERR,
+			 "Zoned block device support is not enabled\n");
+		err = -EOPNOTSUPP;
+		goto free_sb_buf;
+	}
+#endif
+	default_options(sbi);
+	/* parse mount options */
+	options = kstrdup((const char *)data, GFP_KERNEL);
+	if (data && !options) {
+		err = -ENOMEM;
+		goto free_sb_buf;
+	}
+
+	err = parse_options(sb, options);
+	if (err)
+		goto free_options;
+
+	sbi->max_file_blocks = max_file_blocks();
+	sb->s_maxbytes = sbi->max_file_blocks <<
+				le32_to_cpu(raw_super->log_blocksize);
+	sb->s_max_links = F2FS_LINK_MAX;
+	get_random_bytes(&sbi->s_next_generation, sizeof(u32));
+
+#ifdef CONFIG_QUOTA
+	sb->dq_op = &f2fs_quota_operations;
+	if (f2fs_sb_has_quota_ino(sb))
+		sb->s_qcop = &dquot_quotactl_sysfile_ops;
+	else
+		sb->s_qcop = &f2fs_quotactl_ops;
+	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
+
+	if (f2fs_sb_has_quota_ino(sbi->sb)) {
+		for (i = 0; i < MAXQUOTAS; i++) {
+			if (f2fs_qf_ino(sbi->sb, i))
+				sbi->nquota_files++;
+		}
+	}
+#endif
+
+	sb->s_op = &f2fs_sops;
+#ifdef CONFIG_F2FS_FS_ENCRYPTION
+	sb->s_cop = &f2fs_cryptops;
+#endif
+	sb->s_xattr = f2fs_xattr_handlers;
+	sb->s_export_op = &f2fs_export_ops;
+	sb->s_magic = F2FS_SUPER_MAGIC;
+	sb->s_time_gran = 1;
+	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
+		(test_opt(sbi, POSIX_ACL) ? MS_POSIXACL : 0);
+	memcpy(&sb->s_uuid, raw_super->uuid, sizeof(raw_super->uuid));
+	sb->s_iflags |= SB_I_CGROUPWB;
+
+	/* init f2fs-specific super block info */
+	sbi->valid_super_block = valid_super_block;
+	mutex_init(&sbi->gc_mutex);
+	mutex_init(&sbi->cp_mutex);
+	init_rwsem(&sbi->node_write);
+	init_rwsem(&sbi->node_change);
+
+	/* disallow all the data/node/meta page writes */
+	set_sbi_flag(sbi, SBI_POR_DOING);
+	spin_lock_init(&sbi->stat_lock);
+
+	/* init iostat info */
+	spin_lock_init(&sbi->iostat_lock);
+	sbi->iostat_enable = false;
+
+	for (i = 0; i < NR_PAGE_TYPE; i++) {
+		int n = (i == META) ? 1: NR_TEMP_TYPE;
+		int j;
+
+		sbi->write_io[i] = f2fs_kmalloc(sbi,
+					n * sizeof(struct f2fs_bio_info),
+					GFP_KERNEL);
+		if (!sbi->write_io[i]) {
+			err = -ENOMEM;
+			goto free_options;
+		}
+
+		for (j = HOT; j < n; j++) {
+			init_rwsem(&sbi->write_io[i][j].io_rwsem);
+			sbi->write_io[i][j].sbi = sbi;
+			sbi->write_io[i][j].bio = NULL;
+			spin_lock_init(&sbi->write_io[i][j].io_lock);
+			INIT_LIST_HEAD(&sbi->write_io[i][j].io_list);
+		}
+	}
+
+	init_rwsem(&sbi->cp_rwsem);
+	init_waitqueue_head(&sbi->cp_wait);
+	init_sb_info(sbi);
+
+	err = init_percpu_info(sbi);
+	if (err)
+		goto free_bio_info;
+
+	if (F2FS_IO_SIZE(sbi) > 1) {
+		sbi->write_io_dummy =
+			mempool_create_page_pool(2 * (F2FS_IO_SIZE(sbi) - 1), 0);
+		if (!sbi->write_io_dummy) {
+			err = -ENOMEM;
+			goto free_percpu;
+		}
+	}
+
+	/* get an inode for meta space */
+	sbi->meta_inode = f2fs_iget(sb, F2FS_META_INO(sbi));
+	if (IS_ERR(sbi->meta_inode)) {
+		f2fs_msg(sb, KERN_ERR, "Failed to read F2FS meta data inode");
+		err = PTR_ERR(sbi->meta_inode);
+		goto free_io_dummy;
+	}
+
+	err = get_valid_checkpoint(sbi);
+	if (err) {
+		f2fs_msg(sb, KERN_ERR, "Failed to get valid F2FS checkpoint");
+		goto free_meta_inode;
+	}
+
+	/* Initialize device list */
+	err = f2fs_scan_devices(sbi);
+	if (err) {
+		f2fs_msg(sb, KERN_ERR, "Failed to find devices");
+		goto free_devices;
+	}
+
+	sbi->total_valid_node_count =
+				le32_to_cpu(sbi->ckpt->valid_node_count);
+	percpu_counter_set(&sbi->total_valid_inode_count,
+				le32_to_cpu(sbi->ckpt->valid_inode_count));
+	sbi->user_block_count = le64_to_cpu(sbi->ckpt->user_block_count);
+	sbi->total_valid_block_count =
+				le64_to_cpu(sbi->ckpt->valid_block_count);
+	sbi->last_valid_block_count = sbi->total_valid_block_count;
+	sbi->reserved_blocks = 0;
+	sbi->current_reserved_blocks = 0;
+	limit_reserve_root(sbi);
+
+	for (i = 0; i < NR_INODE_TYPE; i++) {
+		INIT_LIST_HEAD(&sbi->inode_list[i]);
+		spin_lock_init(&sbi->inode_lock[i]);
+	}
+
+	init_extent_cache_info(sbi);
+
+	init_ino_entry_info(sbi);
+
+	/* setup f2fs internal modules */
+	err = build_segment_manager(sbi);
+	if (err) {
+		f2fs_msg(sb, KERN_ERR,
+			"Failed to initialize F2FS segment manager");
+		goto free_sm;
+	}
+	err = build_node_manager(sbi);
+	if (err) {
+		f2fs_msg(sb, KERN_ERR,
+			"Failed to initialize F2FS node manager");
+		goto free_nm;
+	}
+
+	/* For write statistics */
+	if (sb->s_bdev->bd_part)
+		sbi->sectors_written_start =
+			(u64)part_stat_read(sb->s_bdev->bd_part, sectors[1]);
+
+	/* Read accumulated write IO statistics if exists */
+	seg_i = CURSEG_I(sbi, CURSEG_HOT_NODE);
+	if (__exist_node_summaries(sbi))
+		sbi->kbytes_written =
+			le64_to_cpu(seg_i->journal->info.kbytes_written);
+
+	build_gc_manager(sbi);
+
+	/* get an inode for node space */
+	sbi->node_inode = f2fs_iget(sb, F2FS_NODE_INO(sbi));
+	if (IS_ERR(sbi->node_inode)) {
+		f2fs_msg(sb, KERN_ERR, "Failed to read node inode");
+		err = PTR_ERR(sbi->node_inode);
+		goto free_nm;
+	}
+
+	err = f2fs_build_stats(sbi);
+	if (err)
+		goto free_node_inode;
+
+	/* read root inode and dentry */
+	root = f2fs_iget(sb, F2FS_ROOT_INO(sbi));
+	if (IS_ERR(root)) {
+		f2fs_msg(sb, KERN_ERR, "Failed to read root inode");
+		err = PTR_ERR(root);
+		goto free_stats;
+	}
+	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
+		iput(root);
+		err = -EINVAL;
+		goto free_node_inode;
+	}
+
+	sb->s_root = d_make_root(root); /* allocate root dentry */
+	if (!sb->s_root) {
+		err = -ENOMEM;
+		goto free_root_inode;
+	}
+
+	err = f2fs_register_sysfs(sbi);
+	if (err)
+		goto free_root_inode;
+
+#ifdef CONFIG_QUOTA
+	/*
+	 * Turn on quotas which were not enabled for read-only mounts if
+	 * filesystem has quota feature, so that they are updated correctly.
+	 */
+	if (f2fs_sb_has_quota_ino(sb) && !f2fs_readonly(sb)) {
+		err = f2fs_enable_quotas(sb);
+		if (err) {
+			f2fs_msg(sb, KERN_ERR,
+				"Cannot turn on quotas: error %d", err);
+			goto free_sysfs;
+		}
+	}
+#endif
+	/* if there are nt orphan nodes free them */
+	err = recover_orphan_inodes(sbi);
+	if (err)
+		goto free_meta;
+
+	/* recover fsynced data */
+	if (!test_opt(sbi, DISABLE_ROLL_FORWARD)) {
+		/*
+		 * mount should be failed, when device has readonly mode, and
+		 * previous checkpoint was not done by clean system shutdown.
+		 */
+		if (bdev_read_only(sb->s_bdev) &&
+				!is_set_ckpt_flags(sbi, CP_UMOUNT_FLAG)) {
+			err = -EROFS;
+			goto free_meta;
+		}
+
+		if (need_fsck)
+			set_sbi_flag(sbi, SBI_NEED_FSCK);
+
+		if (!retry)
+			goto skip_recovery;
+
+		err = recover_fsync_data(sbi, false);
+		if (err < 0) {
+			need_fsck = true;
+			f2fs_msg(sb, KERN_ERR,
+				"Cannot recover all fsync data errno=%d", err);
+			goto free_meta;
+		}
+	} else {
+		err = recover_fsync_data(sbi, true);
+
+		if (!f2fs_readonly(sb) && err > 0) {
+			err = -EINVAL;
+			f2fs_msg(sb, KERN_ERR,
+				"Need to recover fsync data");
+			goto free_meta;
+		}
+	}
+skip_recovery:
+	/* recover_fsync_data() cleared this already */
+	clear_sbi_flag(sbi, SBI_POR_DOING);
+
+	/*
+	 * If filesystem is not mounted as read-only then
+	 * do start the gc_thread.
+	 */
+	if (test_opt(sbi, BG_GC) && !f2fs_readonly(sb)) {
+		/* After POR, we can run background GC thread.*/
+		err = start_gc_thread(sbi);
+		if (err)
+			goto free_meta;
+	}
+	kfree(options);
+
+	/* recover broken superblock */
+	if (recovery) {
+		err = f2fs_commit_super(sbi, true);
+		f2fs_msg(sb, KERN_INFO,
+			"Try to recover %dth superblock, ret: %d",
+			sbi->valid_super_block ? 1 : 2, err);
+	}
+
+	f2fs_join_shrinker(sbi);
+
+	f2fs_tuning_parameters(sbi);
+
+	f2fs_msg(sbi->sb, KERN_NOTICE, "Mounted with checkpoint version = %llx",
+				cur_cp_version(F2FS_CKPT(sbi)));
+	f2fs_update_time(sbi, CP_TIME);
+	f2fs_update_time(sbi, REQ_TIME);
+	return 0;
+
+free_meta:
+#ifdef CONFIG_QUOTA
+	if (f2fs_sb_has_quota_ino(sb) && !f2fs_readonly(sb))
+		f2fs_quota_off_umount(sbi->sb);
+#endif
+	f2fs_sync_inode_meta(sbi);
+	/*
+	 * Some dirty meta pages can be produced by recover_orphan_inodes()
+	 * failed by EIO. Then, iput(node_inode) can trigger balance_fs_bg()
+	 * followed by write_checkpoint() through f2fs_write_node_pages(), which
+	 * falls into an infinite loop in sync_meta_pages().
+	 */
+	truncate_inode_pages_final(META_MAPPING(sbi));
+#ifdef CONFIG_QUOTA
+free_sysfs:
+#endif
+	f2fs_unregister_sysfs(sbi);
+free_root_inode:
+	dput(sb->s_root);
+	sb->s_root = NULL;
+free_stats:
+	f2fs_destroy_stats(sbi);
+free_node_inode:
+	release_ino_entry(sbi, true);
+	truncate_inode_pages_final(NODE_MAPPING(sbi));
+	iput(sbi->node_inode);
+free_nm:
+	destroy_node_manager(sbi);
+free_sm:
+	destroy_segment_manager(sbi);
+free_devices:
+	destroy_device_list(sbi);
+	kfree(sbi->ckpt);
+free_meta_inode:
+	make_bad_inode(sbi->meta_inode);
+	iput(sbi->meta_inode);
+free_io_dummy:
+	mempool_destroy(sbi->write_io_dummy);
+free_percpu:
+	destroy_percpu_info(sbi);
+free_bio_info:
+	for (i = 0; i < NR_PAGE_TYPE; i++)
+		kfree(sbi->write_io[i]);
+free_options:
+#ifdef CONFIG_QUOTA
+	for (i = 0; i < MAXQUOTAS; i++)
+		kfree(F2FS_OPTION(sbi).s_qf_names[i]);
+#endif
+	kfree(options);
+free_sb_buf:
+	kfree(raw_super);
+free_sbi:
+	if (sbi->s_chksum_driver)
+		crypto_free_shash(sbi->s_chksum_driver);
+	kfree(sbi);
+
+	/* give only one another chance */
+	if (retry) {
+		retry = false;
+		shrink_dcache_sb(sb);
+		goto try_onemore;
+	}
+	return err;
+}
+
+static struct dentry *f2fs_mount(struct file_system_type *fs_type, int flags,
+			const char *dev_name, void *data)
+{
+	return mount_bdev(fs_type, flags, dev_name, data, f2fs_fill_super);
+}
+
+static void kill_f2fs_super(struct super_block *sb)
+{
+	if (sb->s_root) {
+		set_sbi_flag(F2FS_SB(sb), SBI_IS_CLOSE);
+		stop_gc_thread(F2FS_SB(sb));
+		stop_discard_thread(F2FS_SB(sb));
+	}
+	kill_block_super(sb);
+}
+
+static struct file_system_type f2fs_fs_type = {
+	.owner		= THIS_MODULE,
+	.name		= "f2fs",
+	.mount		= f2fs_mount,
+	.kill_sb	= kill_f2fs_super,
+	.fs_flags	= FS_REQUIRES_DEV,
+};
+MODULE_ALIAS_FS("f2fs");
+
+static int __init init_inodecache(void)
+{
+	f2fs_inode_cachep = kmem_cache_create("f2fs_inode_cache",
+			sizeof(struct f2fs_inode_info), 0,
+			SLAB_RECLAIM_ACCOUNT|SLAB_ACCOUNT, NULL);
+	if (!f2fs_inode_cachep)
+		return -ENOMEM;
+	return 0;
+}
+
+static void destroy_inodecache(void)
+{
+	/*
+	 * Make sure all delayed rcu free inodes are flushed before we
+	 * destroy cache.
+	 */
+	rcu_barrier();
+	kmem_cache_destroy(f2fs_inode_cachep);
+}
+
+static int __init init_f2fs_fs(void)
+{
+	int err;
+
+	if (PAGE_SIZE != F2FS_BLKSIZE) {
+		printk("F2FS not supported on PAGE_SIZE(%lu) != %d\n",
+				PAGE_SIZE, F2FS_BLKSIZE);
+		return -EINVAL;
+	}
+
+	f2fs_build_trace_ios();
+
+	err = init_inodecache();
+	if (err)
+		goto fail;
+	err = create_node_manager_caches();
+	if (err)
+		goto free_inodecache;
+	err = create_segment_manager_caches();
+	if (err)
+		goto free_node_manager_caches;
+	err = create_checkpoint_caches();
+	if (err)
+		goto free_segment_manager_caches;
+	err = create_extent_cache();
+	if (err)
+		goto free_checkpoint_caches;
+	err = f2fs_init_sysfs();
+	if (err)
+		goto free_extent_cache;
+	err = register_shrinker(&f2fs_shrinker_info);
+	if (err)
+		goto free_sysfs;
+	err = register_filesystem(&f2fs_fs_type);
+	if (err)
+		goto free_shrinker;
+	err = f2fs_create_root_stats();
+	if (err)
+		goto free_filesystem;
+	err = f2fs_init_post_read_processing();
+	if (err)
+		goto free_root_stats;
+	return 0;
+
+free_root_stats:
+	f2fs_destroy_root_stats();
+free_filesystem:
+	unregister_filesystem(&f2fs_fs_type);
+free_shrinker:
+	unregister_shrinker(&f2fs_shrinker_info);
+free_sysfs:
+	f2fs_exit_sysfs();
+free_extent_cache:
+	destroy_extent_cache();
+free_checkpoint_caches:
+	destroy_checkpoint_caches();
+free_segment_manager_caches:
+	destroy_segment_manager_caches();
+free_node_manager_caches:
+	destroy_node_manager_caches();
+free_inodecache:
+	destroy_inodecache();
+fail:
+	return err;
+}
+
+static void __exit exit_f2fs_fs(void)
+{
+	f2fs_destroy_post_read_processing();
+	f2fs_destroy_root_stats();
+	unregister_filesystem(&f2fs_fs_type);
+	unregister_shrinker(&f2fs_shrinker_info);
+	f2fs_exit_sysfs();
+	destroy_extent_cache();
+	destroy_checkpoint_caches();
+	destroy_segment_manager_caches();
+	destroy_node_manager_caches();
+	destroy_inodecache();
+	f2fs_destroy_trace_ios();
+}
+
+module_init(init_f2fs_fs)
+module_exit(exit_f2fs_fs)
+
+MODULE_AUTHOR("Samsung Electronics's Praesto Team");
+MODULE_DESCRIPTION("Flash Friendly File System");
+MODULE_LICENSE("GPL");
+
diff --git a/src/kernel/linux/v4.14/fs/f2fs/sysfs.c b/src/kernel/linux/v4.14/fs/f2fs/sysfs.c
new file mode 100644
index 0000000..5940232
--- /dev/null
+++ b/src/kernel/linux/v4.14/fs/f2fs/sysfs.c
@@ -0,0 +1,667 @@
+/*
+ * f2fs sysfs interface
+ *
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ *             http://www.samsung.com/
+ * Copyright (c) 2017 Chao Yu <chao@kernel.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/compiler.h>
+#include <linux/proc_fs.h>
+#include <linux/f2fs_fs.h>
+#include <linux/seq_file.h>
+
+#include "f2fs.h"
+#include "segment.h"
+#include "gc.h"
+
+static struct proc_dir_entry *f2fs_proc_root;
+
+/* Sysfs support for f2fs */
+enum {
+	GC_THREAD,	/* struct f2fs_gc_thread */
+	SM_INFO,	/* struct f2fs_sm_info */
+	DCC_INFO,	/* struct discard_cmd_control */
+	NM_INFO,	/* struct f2fs_nm_info */
+	F2FS_SBI,	/* struct f2fs_sb_info */
+#ifdef CONFIG_F2FS_FAULT_INJECTION
+	FAULT_INFO_RATE,	/* struct f2fs_fault_info */
+	FAULT_INFO_TYPE,	/* struct f2fs_fault_info */
+#endif
+	RESERVED_BLOCKS,	/* struct f2fs_sb_info */
+};
+
+struct f2fs_attr {
+	struct attribute attr;
+	ssize_t (*show)(struct f2fs_attr *, struct f2fs_sb_info *, char *);
+	ssize_t (*store)(struct f2fs_attr *, struct f2fs_sb_info *,
+			 const char *, size_t);
+	int struct_type;
+	int offset;
+	int id;
+};
+
+static unsigned char *__struct_ptr(struct f2fs_sb_info *sbi, int struct_type)
+{
+	if (struct_type == GC_THREAD)
+		return (unsigned char *)sbi->gc_thread;
+	else if (struct_type == SM_INFO)
+		return (unsigned char *)SM_I(sbi);
+	else if (struct_type == DCC_INFO)
+		return (unsigned char *)SM_I(sbi)->dcc_info;
+	else if (struct_type == NM_INFO)
+		return (unsigned char *)NM_I(sbi);
+	else if (struct_type == F2FS_SBI || struct_type == RESERVED_BLOCKS)
+		return (unsigned char *)sbi;
+#ifdef CONFIG_F2FS_FAULT_INJECTION
+	else if (struct_type == FAULT_INFO_RATE ||
+					struct_type == FAULT_INFO_TYPE)
+		return (unsigned char *)&F2FS_OPTION(sbi).fault_info;
+#endif
+	return NULL;
+}
+
+static ssize_t dirty_segments_show(struct f2fs_attr *a,
+		struct f2fs_sb_info *sbi, char *buf)
+{
+	return snprintf(buf, PAGE_SIZE, "%llu\n",
+		(unsigned long long)(dirty_segments(sbi)));
+}
+
+static ssize_t lifetime_write_kbytes_show(struct f2fs_attr *a,
+		struct f2fs_sb_info *sbi, char *buf)
+{
+	struct super_block *sb = sbi->sb;
+
+	if (!sb->s_bdev->bd_part)
+		return snprintf(buf, PAGE_SIZE, "0\n");
+
+	return snprintf(buf, PAGE_SIZE, "%llu\n",
+		(unsigned long long)(sbi->kbytes_written +
+			BD_PART_WRITTEN(sbi)));
+}
+
+static ssize_t features_show(struct f2fs_attr *a,
+		struct f2fs_sb_info *sbi, char *buf)
+{
+	struct super_block *sb = sbi->sb;
+	int len = 0;
+
+	if (!sb->s_bdev->bd_part)
+		return snprintf(buf, PAGE_SIZE, "0\n");
+
+	if (f2fs_sb_has_encrypt(sb))
+		len += snprintf(buf, PAGE_SIZE - len, "%s",
+						"encryption");
+	if (f2fs_sb_has_blkzoned(sb))
+		len += snprintf(buf + len, PAGE_SIZE - len, "%s%s",
+				len ? ", " : "", "blkzoned");
+	if (f2fs_sb_has_extra_attr(sb))
+		len += snprintf(buf + len, PAGE_SIZE - len, "%s%s",
+				len ? ", " : "", "extra_attr");
+	if (f2fs_sb_has_project_quota(sb))
+		len += snprintf(buf + len, PAGE_SIZE - len, "%s%s",
+				len ? ", " : "", "projquota");
+	if (f2fs_sb_has_inode_chksum(sb))
+		len += snprintf(buf + len, PAGE_SIZE - len, "%s%s",
+				len ? ", " : "", "inode_checksum");
+	if (f2fs_sb_has_flexible_inline_xattr(sb))
+		len += snprintf(buf + len, PAGE_SIZE - len, "%s%s",
+				len ? ", " : "", "flexible_inline_xattr");
+	if (f2fs_sb_has_quota_ino(sb))
+		len += snprintf(buf + len, PAGE_SIZE - len, "%s%s",
+				len ? ", " : "", "quota_ino");
+	if (f2fs_sb_has_inode_crtime(sb))
+		len += snprintf(buf + len, PAGE_SIZE - len, "%s%s",
+				len ? ", " : "", "inode_crtime");
+	if (f2fs_sb_has_lost_found(sb))
+		len += snprintf(buf + len, PAGE_SIZE - len, "%s%s",
+				len ? ", " : "", "lost_found");
+	len += snprintf(buf + len, PAGE_SIZE - len, "\n");
+	return len;
+}
+
+static ssize_t current_reserved_blocks_show(struct f2fs_attr *a,
+					struct f2fs_sb_info *sbi, char *buf)
+{
+	return snprintf(buf, PAGE_SIZE, "%u\n", sbi->current_reserved_blocks);
+}
+
+static ssize_t f2fs_sbi_show(struct f2fs_attr *a,
+			struct f2fs_sb_info *sbi, char *buf)
+{
+	unsigned char *ptr = NULL;
+	unsigned int *ui;
+
+	ptr = __struct_ptr(sbi, a->struct_type);
+	if (!ptr)
+		return -EINVAL;
+
+	if (!strcmp(a->attr.name, "extension_list")) {
+		__u8 (*extlist)[F2FS_EXTENSION_LEN] =
+					sbi->raw_super->extension_list;
+		int cold_count = le32_to_cpu(sbi->raw_super->extension_count);
+		int hot_count = sbi->raw_super->hot_ext_count;
+		int len = 0, i;
+
+		len += snprintf(buf + len, PAGE_SIZE - len,
+						"cold file extenstion:\n");
+		for (i = 0; i < cold_count; i++)
+			len += snprintf(buf + len, PAGE_SIZE - len, "%s\n",
+								extlist[i]);
+
+		len += snprintf(buf + len, PAGE_SIZE - len,
+						"hot file extenstion:\n");
+		for (i = cold_count; i < cold_count + hot_count; i++)
+			len += snprintf(buf + len, PAGE_SIZE - len, "%s\n",
+								extlist[i]);
+		return len;
+	}
+
+	ui = (unsigned int *)(ptr + a->offset);
+
+	return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
+}
+
+static ssize_t f2fs_sbi_store(struct f2fs_attr *a,
+			struct f2fs_sb_info *sbi,
+			const char *buf, size_t count)
+{
+	unsigned char *ptr;
+	unsigned long t;
+	unsigned int *ui;
+	ssize_t ret;
+
+	ptr = __struct_ptr(sbi, a->struct_type);
+	if (!ptr)
+		return -EINVAL;
+
+	if (!strcmp(a->attr.name, "extension_list")) {
+		const char *name = strim((char *)buf);
+		bool set = true, hot;
+
+		if (!strncmp(name, "[h]", 3))
+			hot = true;
+		else if (!strncmp(name, "[c]", 3))
+			hot = false;
+		else
+			return -EINVAL;
+
+		name += 3;
+
+		if (*name == '!') {
+			name++;
+			set = false;
+		}
+
+		if (strlen(name) >= F2FS_EXTENSION_LEN)
+			return -EINVAL;
+
+		down_write(&sbi->sb_lock);
+
+		ret = update_extension_list(sbi, name, hot, set);
+		if (ret)
+			goto out;
+
+		ret = f2fs_commit_super(sbi, false);
+		if (ret)
+			update_extension_list(sbi, name, hot, !set);
+out:
+		up_write(&sbi->sb_lock);
+		return ret ? ret : count;
+	}
+
+	ui = (unsigned int *)(ptr + a->offset);
+
+	ret = kstrtoul(skip_spaces(buf), 0, &t);
+	if (ret < 0)
+		return ret;
+#ifdef CONFIG_F2FS_FAULT_INJECTION
+	if (a->struct_type == FAULT_INFO_TYPE && t >= (1 << FAULT_MAX))
+		return -EINVAL;
+#endif
+	if (a->struct_type == RESERVED_BLOCKS) {
+		spin_lock(&sbi->stat_lock);
+		if (t > (unsigned long)(sbi->user_block_count -
+				F2FS_OPTION(sbi).root_reserved_blocks)) {
+			spin_unlock(&sbi->stat_lock);
+			return -EINVAL;
+		}
+		*ui = t;
+		sbi->current_reserved_blocks = min(sbi->reserved_blocks,
+				sbi->user_block_count - valid_user_blocks(sbi));
+		spin_unlock(&sbi->stat_lock);
+		return count;
+	}
+
+	if (!strcmp(a->attr.name, "discard_granularity")) {
+		if (t == 0 || t > MAX_PLIST_NUM)
+			return -EINVAL;
+		if (t == *ui)
+			return count;
+		*ui = t;
+		return count;
+	}
+
+	if (!strcmp(a->attr.name, "trim_sections"))
+		return -EINVAL;
+
+	*ui = t;
+
+	if (!strcmp(a->attr.name, "iostat_enable") && *ui == 0)
+		f2fs_reset_iostat(sbi);
+	if (!strcmp(a->attr.name, "gc_urgent") && t == 1 && sbi->gc_thread) {
+		sbi->gc_thread->gc_wake = 1;
+		wake_up_interruptible_all(&sbi->gc_thread->gc_wait_queue_head);
+		wake_up_discard_thread(sbi, true);
+	}
+
+	return count;
+}
+
+static ssize_t f2fs_attr_show(struct kobject *kobj,
+				struct attribute *attr, char *buf)
+{
+	struct f2fs_sb_info *sbi = container_of(kobj, struct f2fs_sb_info,
+								s_kobj);
+	struct f2fs_attr *a = container_of(attr, struct f2fs_attr, attr);
+
+	return a->show ? a->show(a, sbi, buf) : 0;
+}
+
+static ssize_t f2fs_attr_store(struct kobject *kobj, struct attribute *attr,
+						const char *buf, size_t len)
+{
+	struct f2fs_sb_info *sbi = container_of(kobj, struct f2fs_sb_info,
+									s_kobj);
+	struct f2fs_attr *a = container_of(attr, struct f2fs_attr, attr);
+
+	return a->store ? a->store(a, sbi, buf, len) : 0;
+}
+
+static void f2fs_sb_release(struct kobject *kobj)
+{
+	struct f2fs_sb_info *sbi = container_of(kobj, struct f2fs_sb_info,
+								s_kobj);
+	complete(&sbi->s_kobj_unregister);
+}
+
+enum feat_id {
+	FEAT_CRYPTO = 0,
+	FEAT_BLKZONED,
+	FEAT_ATOMIC_WRITE,
+	FEAT_EXTRA_ATTR,
+	FEAT_PROJECT_QUOTA,
+	FEAT_INODE_CHECKSUM,
+	FEAT_FLEXIBLE_INLINE_XATTR,
+	FEAT_QUOTA_INO,
+	FEAT_INODE_CRTIME,
+	FEAT_LOST_FOUND,
+};
+
+static ssize_t f2fs_feature_show(struct f2fs_attr *a,
+		struct f2fs_sb_info *sbi, char *buf)
+{
+	switch (a->id) {
+	case FEAT_CRYPTO:
+	case FEAT_BLKZONED:
+	case FEAT_ATOMIC_WRITE:
+	case FEAT_EXTRA_ATTR:
+	case FEAT_PROJECT_QUOTA:
+	case FEAT_INODE_CHECKSUM:
+	case FEAT_FLEXIBLE_INLINE_XATTR:
+	case FEAT_QUOTA_INO:
+	case FEAT_INODE_CRTIME:
+	case FEAT_LOST_FOUND:
+		return snprintf(buf, PAGE_SIZE, "supported\n");
+	}
+	return 0;
+}
+
+#define F2FS_ATTR_OFFSET(_struct_type, _name, _mode, _show, _store, _offset) \
+static struct f2fs_attr f2fs_attr_##_name = {			\
+	.attr = {.name = __stringify(_name), .mode = _mode },	\
+	.show	= _show,					\
+	.store	= _store,					\
+	.struct_type = _struct_type,				\
+	.offset = _offset					\
+}
+
+#define F2FS_RW_ATTR(struct_type, struct_name, name, elname)	\
+	F2FS_ATTR_OFFSET(struct_type, name, 0644,		\
+		f2fs_sbi_show, f2fs_sbi_store,			\
+		offsetof(struct struct_name, elname))
+
+#define F2FS_GENERAL_RO_ATTR(name) \
+static struct f2fs_attr f2fs_attr_##name = __ATTR(name, 0444, name##_show, NULL)
+
+#define F2FS_FEATURE_RO_ATTR(_name, _id)			\
+static struct f2fs_attr f2fs_attr_##_name = {			\
+	.attr = {.name = __stringify(_name), .mode = 0444 },	\
+	.show	= f2fs_feature_show,				\
+	.id	= _id,						\
+}
+
+F2FS_RW_ATTR(GC_THREAD, f2fs_gc_kthread, gc_urgent_sleep_time,
+							urgent_sleep_time);
+F2FS_RW_ATTR(GC_THREAD, f2fs_gc_kthread, gc_min_sleep_time, min_sleep_time);
+F2FS_RW_ATTR(GC_THREAD, f2fs_gc_kthread, gc_max_sleep_time, max_sleep_time);
+F2FS_RW_ATTR(GC_THREAD, f2fs_gc_kthread, gc_no_gc_sleep_time, no_gc_sleep_time);
+F2FS_RW_ATTR(GC_THREAD, f2fs_gc_kthread, gc_idle, gc_idle);
+F2FS_RW_ATTR(GC_THREAD, f2fs_gc_kthread, gc_urgent, gc_urgent);
+F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, reclaim_segments, rec_prefree_segments);
+F2FS_RW_ATTR(DCC_INFO, discard_cmd_control, max_small_discards, max_discards);
+F2FS_RW_ATTR(DCC_INFO, discard_cmd_control, discard_granularity, discard_granularity);
+F2FS_RW_ATTR(RESERVED_BLOCKS, f2fs_sb_info, reserved_blocks, reserved_blocks);
+F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, batched_trim_sections, trim_sections);
+F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, ipu_policy, ipu_policy);
+F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, min_ipu_util, min_ipu_util);
+F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, min_fsync_blocks, min_fsync_blocks);
+F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, min_hot_blocks, min_hot_blocks);
+F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, min_ssr_sections, min_ssr_sections);
+F2FS_RW_ATTR(NM_INFO, f2fs_nm_info, ram_thresh, ram_thresh);
+F2FS_RW_ATTR(NM_INFO, f2fs_nm_info, ra_nid_pages, ra_nid_pages);
+F2FS_RW_ATTR(NM_INFO, f2fs_nm_info, dirty_nats_ratio, dirty_nats_ratio);
+F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, max_victim_search, max_victim_search);
+F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, dir_level, dir_level);
+F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, cp_interval, interval_time[CP_TIME]);
+F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, idle_interval, interval_time[REQ_TIME]);
+F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, iostat_enable, iostat_enable);
+F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, readdir_ra, readdir_ra);
+F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, gc_pin_file_thresh, gc_pin_file_threshold);
+F2FS_RW_ATTR(F2FS_SBI, f2fs_super_block, extension_list, extension_list);
+#ifdef CONFIG_F2FS_FAULT_INJECTION
+F2FS_RW_ATTR(FAULT_INFO_RATE, f2fs_fault_info, inject_rate, inject_rate);
+F2FS_RW_ATTR(FAULT_INFO_TYPE, f2fs_fault_info, inject_type, inject_type);
+#endif
+F2FS_GENERAL_RO_ATTR(dirty_segments);
+F2FS_GENERAL_RO_ATTR(lifetime_write_kbytes);
+F2FS_GENERAL_RO_ATTR(features);
+F2FS_GENERAL_RO_ATTR(current_reserved_blocks);
+
+#ifdef CONFIG_F2FS_FS_ENCRYPTION
+F2FS_FEATURE_RO_ATTR(encryption, FEAT_CRYPTO);
+#endif
+#ifdef CONFIG_BLK_DEV_ZONED
+F2FS_FEATURE_RO_ATTR(block_zoned, FEAT_BLKZONED);
+#endif
+F2FS_FEATURE_RO_ATTR(atomic_write, FEAT_ATOMIC_WRITE);
+F2FS_FEATURE_RO_ATTR(extra_attr, FEAT_EXTRA_ATTR);
+F2FS_FEATURE_RO_ATTR(project_quota, FEAT_PROJECT_QUOTA);
+F2FS_FEATURE_RO_ATTR(inode_checksum, FEAT_INODE_CHECKSUM);
+F2FS_FEATURE_RO_ATTR(flexible_inline_xattr, FEAT_FLEXIBLE_INLINE_XATTR);
+F2FS_FEATURE_RO_ATTR(quota_ino, FEAT_QUOTA_INO);
+F2FS_FEATURE_RO_ATTR(inode_crtime, FEAT_INODE_CRTIME);
+F2FS_FEATURE_RO_ATTR(lost_found, FEAT_LOST_FOUND);
+
+#define ATTR_LIST(name) (&f2fs_attr_##name.attr)
+static struct attribute *f2fs_attrs[] = {
+	ATTR_LIST(gc_urgent_sleep_time),
+	ATTR_LIST(gc_min_sleep_time),
+	ATTR_LIST(gc_max_sleep_time),
+	ATTR_LIST(gc_no_gc_sleep_time),
+	ATTR_LIST(gc_idle),
+	ATTR_LIST(gc_urgent),
+	ATTR_LIST(reclaim_segments),
+	ATTR_LIST(max_small_discards),
+	ATTR_LIST(discard_granularity),
+	ATTR_LIST(batched_trim_sections),
+	ATTR_LIST(ipu_policy),
+	ATTR_LIST(min_ipu_util),
+	ATTR_LIST(min_fsync_blocks),
+	ATTR_LIST(min_hot_blocks),
+	ATTR_LIST(min_ssr_sections),
+	ATTR_LIST(max_victim_search),
+	ATTR_LIST(dir_level),
+	ATTR_LIST(ram_thresh),
+	ATTR_LIST(ra_nid_pages),
+	ATTR_LIST(dirty_nats_ratio),
+	ATTR_LIST(cp_interval),
+	ATTR_LIST(idle_interval),
+	ATTR_LIST(iostat_enable),
+	ATTR_LIST(readdir_ra),
+	ATTR_LIST(gc_pin_file_thresh),
+	ATTR_LIST(extension_list),
+#ifdef CONFIG_F2FS_FAULT_INJECTION
+	ATTR_LIST(inject_rate),
+	ATTR_LIST(inject_type),
+#endif
+	ATTR_LIST(dirty_segments),
+	ATTR_LIST(lifetime_write_kbytes),
+	ATTR_LIST(features),
+	ATTR_LIST(reserved_blocks),
+	ATTR_LIST(current_reserved_blocks),
+	NULL,
+};
+
+static struct attribute *f2fs_feat_attrs[] = {
+#ifdef CONFIG_F2FS_FS_ENCRYPTION
+	ATTR_LIST(encryption),
+#endif
+#ifdef CONFIG_BLK_DEV_ZONED
+	ATTR_LIST(block_zoned),
+#endif
+	ATTR_LIST(atomic_write),
+	ATTR_LIST(extra_attr),
+	ATTR_LIST(project_quota),
+	ATTR_LIST(inode_checksum),
+	ATTR_LIST(flexible_inline_xattr),
+	ATTR_LIST(quota_ino),
+	ATTR_LIST(inode_crtime),
+	ATTR_LIST(lost_found),
+	NULL,
+};
+
+static const struct sysfs_ops f2fs_attr_ops = {
+	.show	= f2fs_attr_show,
+	.store	= f2fs_attr_store,
+};
+
+static struct kobj_type f2fs_sb_ktype = {
+	.default_attrs	= f2fs_attrs,
+	.sysfs_ops	= &f2fs_attr_ops,
+	.release	= f2fs_sb_release,
+};
+
+static struct kobj_type f2fs_ktype = {
+	.sysfs_ops	= &f2fs_attr_ops,
+};
+
+static struct kset f2fs_kset = {
+	.kobj   = {.ktype = &f2fs_ktype},
+};
+
+static struct kobj_type f2fs_feat_ktype = {
+	.default_attrs	= f2fs_feat_attrs,
+	.sysfs_ops	= &f2fs_attr_ops,
+};
+
+static struct kobject f2fs_feat = {
+	.kset	= &f2fs_kset,
+};
+
+static int __maybe_unused segment_info_seq_show(struct seq_file *seq,
+						void *offset)
+{
+	struct super_block *sb = seq->private;
+	struct f2fs_sb_info *sbi = F2FS_SB(sb);
+	unsigned int total_segs =
+			le32_to_cpu(sbi->raw_super->segment_count_main);
+	int i;
+
+	seq_puts(seq, "format: segment_type|valid_blocks\n"
+		"segment_type(0:HD, 1:WD, 2:CD, 3:HN, 4:WN, 5:CN)\n");
+
+	for (i = 0; i < total_segs; i++) {
+		struct seg_entry *se = get_seg_entry(sbi, i);
+
+		if ((i % 10) == 0)
+			seq_printf(seq, "%-10d", i);
+		seq_printf(seq, "%d|%-3u", se->type,
+					get_valid_blocks(sbi, i, false));
+		if ((i % 10) == 9 || i == (total_segs - 1))
+			seq_putc(seq, '\n');
+		else
+			seq_putc(seq, ' ');
+	}
+
+	return 0;
+}
+
+static int __maybe_unused segment_bits_seq_show(struct seq_file *seq,
+						void *offset)
+{
+	struct super_block *sb = seq->private;
+	struct f2fs_sb_info *sbi = F2FS_SB(sb);
+	unsigned int total_segs =
+			le32_to_cpu(sbi->raw_super->segment_count_main);
+	int i, j;
+
+	seq_puts(seq, "format: segment_type|valid_blocks|bitmaps\n"
+		"segment_type(0:HD, 1:WD, 2:CD, 3:HN, 4:WN, 5:CN)\n");
+
+	for (i = 0; i < total_segs; i++) {
+		struct seg_entry *se = get_seg_entry(sbi, i);
+
+		seq_printf(seq, "%-10d", i);
+		seq_printf(seq, "%d|%-3u|", se->type,
+					get_valid_blocks(sbi, i, false));
+		for (j = 0; j < SIT_VBLOCK_MAP_SIZE; j++)
+			seq_printf(seq, " %.2x", se->cur_valid_map[j]);
+		seq_putc(seq, '\n');
+	}
+	return 0;
+}
+
+static int __maybe_unused iostat_info_seq_show(struct seq_file *seq,
+					       void *offset)
+{
+	struct super_block *sb = seq->private;
+	struct f2fs_sb_info *sbi = F2FS_SB(sb);
+	time64_t now = ktime_get_real_seconds();
+
+	if (!sbi->iostat_enable)
+		return 0;
+
+	seq_printf(seq, "time:		%-16llu\n", now);
+
+	/* print app IOs */
+	seq_printf(seq, "app buffered:	%-16llu\n",
+				sbi->write_iostat[APP_BUFFERED_IO]);
+	seq_printf(seq, "app direct:	%-16llu\n",
+				sbi->write_iostat[APP_DIRECT_IO]);
+	seq_printf(seq, "app mapped:	%-16llu\n",
+				sbi->write_iostat[APP_MAPPED_IO]);
+
+	/* print fs IOs */
+	seq_printf(seq, "fs data:	%-16llu\n",
+				sbi->write_iostat[FS_DATA_IO]);
+	seq_printf(seq, "fs node:	%-16llu\n",
+				sbi->write_iostat[FS_NODE_IO]);
+	seq_printf(seq, "fs meta:	%-16llu\n",
+				sbi->write_iostat[FS_META_IO]);
+	seq_printf(seq, "fs gc data:	%-16llu\n",
+				sbi->write_iostat[FS_GC_DATA_IO]);
+	seq_printf(seq, "fs gc node:	%-16llu\n",
+				sbi->write_iostat[FS_GC_NODE_IO]);
+	seq_printf(seq, "fs cp data:	%-16llu\n",
+				sbi->write_iostat[FS_CP_DATA_IO]);
+	seq_printf(seq, "fs cp node:	%-16llu\n",
+				sbi->write_iostat[FS_CP_NODE_IO]);
+	seq_printf(seq, "fs cp meta:	%-16llu\n",
+				sbi->write_iostat[FS_CP_META_IO]);
+	seq_printf(seq, "fs discard:	%-16llu\n",
+				sbi->write_iostat[FS_DISCARD]);
+
+	return 0;
+}
+
+#define F2FS_PROC_FILE_DEF(_name)					\
+static int _name##_open_fs(struct inode *inode, struct file *file)	\
+{									\
+	return single_open(file, _name##_seq_show, PDE_DATA(inode));	\
+}									\
+									\
+static const struct file_operations f2fs_seq_##_name##_fops = {		\
+	.open = _name##_open_fs,					\
+	.read = seq_read,						\
+	.llseek = seq_lseek,						\
+	.release = single_release,					\
+};
+
+F2FS_PROC_FILE_DEF(segment_info);
+F2FS_PROC_FILE_DEF(segment_bits);
+F2FS_PROC_FILE_DEF(iostat_info);
+
+int __init f2fs_init_sysfs(void)
+{
+	int ret;
+
+	kobject_set_name(&f2fs_kset.kobj, "f2fs");
+	f2fs_kset.kobj.parent = fs_kobj;
+	ret = kset_register(&f2fs_kset);
+	if (ret)
+		return ret;
+
+	ret = kobject_init_and_add(&f2fs_feat, &f2fs_feat_ktype,
+				   NULL, "features");
+	if (ret) {
+		kobject_put(&f2fs_feat);
+		kset_unregister(&f2fs_kset);
+	} else {
+		f2fs_proc_root = proc_mkdir("fs/f2fs", NULL);
+	}
+	return ret;
+}
+
+void f2fs_exit_sysfs(void)
+{
+	kobject_put(&f2fs_feat);
+	kset_unregister(&f2fs_kset);
+	remove_proc_entry("fs/f2fs", NULL);
+	f2fs_proc_root = NULL;
+}
+
+int f2fs_register_sysfs(struct f2fs_sb_info *sbi)
+{
+	struct super_block *sb = sbi->sb;
+	int err;
+
+	sbi->s_kobj.kset = &f2fs_kset;
+	init_completion(&sbi->s_kobj_unregister);
+	err = kobject_init_and_add(&sbi->s_kobj, &f2fs_sb_ktype, NULL,
+				"%s", sb->s_id);
+	if (err) {
+		kobject_put(&sbi->s_kobj);
+		wait_for_completion(&sbi->s_kobj_unregister);
+		return err;
+	}
+
+	if (f2fs_proc_root)
+		sbi->s_proc = proc_mkdir(sb->s_id, f2fs_proc_root);
+
+	if (sbi->s_proc) {
+		proc_create_data("segment_info", S_IRUGO, sbi->s_proc,
+				 &f2fs_seq_segment_info_fops, sb);
+		proc_create_data("segment_bits", S_IRUGO, sbi->s_proc,
+				 &f2fs_seq_segment_bits_fops, sb);
+		proc_create_data("iostat_info", S_IRUGO, sbi->s_proc,
+				&f2fs_seq_iostat_info_fops, sb);
+	}
+	return 0;
+}
+
+void f2fs_unregister_sysfs(struct f2fs_sb_info *sbi)
+{
+	if (sbi->s_proc) {
+		remove_proc_entry("iostat_info", sbi->s_proc);
+		remove_proc_entry("segment_info", sbi->s_proc);
+		remove_proc_entry("segment_bits", sbi->s_proc);
+		remove_proc_entry(sbi->sb->s_id, f2fs_proc_root);
+	}
+	kobject_del(&sbi->s_kobj);
+	kobject_put(&sbi->s_kobj);
+}
diff --git a/src/kernel/linux/v4.14/fs/f2fs/trace.c b/src/kernel/linux/v4.14/fs/f2fs/trace.c
new file mode 100644
index 0000000..8ac1851
--- /dev/null
+++ b/src/kernel/linux/v4.14/fs/f2fs/trace.c
@@ -0,0 +1,168 @@
+/*
+ * f2fs IO tracer
+ *
+ * Copyright (c) 2014 Motorola Mobility
+ * Copyright (c) 2014 Jaegeuk Kim <jaegeuk@kernel.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/fs.h>
+#include <linux/f2fs_fs.h>
+#include <linux/sched.h>
+#include <linux/radix-tree.h>
+
+#include "f2fs.h"
+#include "trace.h"
+
+static RADIX_TREE(pids, GFP_ATOMIC);
+static spinlock_t pids_lock;
+static struct last_io_info last_io;
+
+static inline void __print_last_io(void)
+{
+	if (!last_io.len)
+		return;
+
+	trace_printk("%3x:%3x %4x %-16s %2x %5x %5x %12x %4x\n",
+			last_io.major, last_io.minor,
+			last_io.pid, "----------------",
+			last_io.type,
+			last_io.fio.op, last_io.fio.op_flags,
+			last_io.fio.new_blkaddr,
+			last_io.len);
+	memset(&last_io, 0, sizeof(last_io));
+}
+
+static int __file_type(struct inode *inode, pid_t pid)
+{
+	if (f2fs_is_atomic_file(inode))
+		return __ATOMIC_FILE;
+	else if (f2fs_is_volatile_file(inode))
+		return __VOLATILE_FILE;
+	else if (S_ISDIR(inode->i_mode))
+		return __DIR_FILE;
+	else if (inode->i_ino == F2FS_NODE_INO(F2FS_I_SB(inode)))
+		return __NODE_FILE;
+	else if (inode->i_ino == F2FS_META_INO(F2FS_I_SB(inode)))
+		return __META_FILE;
+	else if (pid)
+		return __NORMAL_FILE;
+	else
+		return __MISC_FILE;
+}
+
+void f2fs_trace_pid(struct page *page)
+{
+	struct inode *inode = page->mapping->host;
+	pid_t pid = task_pid_nr(current);
+	void *p;
+
+	set_page_private(page, (unsigned long)pid);
+
+retry:
+	if (radix_tree_preload(GFP_NOFS))
+		return;
+
+	spin_lock(&pids_lock);
+	p = radix_tree_lookup(&pids, pid);
+	if (p == current)
+		goto out;
+	if (p)
+		radix_tree_delete(&pids, pid);
+
+	if (radix_tree_insert(&pids, pid, current)) {
+		spin_unlock(&pids_lock);
+		radix_tree_preload_end();
+		cond_resched();
+		goto retry;
+	}
+
+	trace_printk("%3x:%3x %4x %-16s\n",
+			MAJOR(inode->i_sb->s_dev), MINOR(inode->i_sb->s_dev),
+			pid, current->comm);
+out:
+	spin_unlock(&pids_lock);
+	radix_tree_preload_end();
+}
+
+void f2fs_trace_ios(struct f2fs_io_info *fio, int flush)
+{
+	struct inode *inode;
+	pid_t pid;
+	int major, minor;
+
+	if (flush) {
+		__print_last_io();
+		return;
+	}
+
+	inode = fio->page->mapping->host;
+	pid = page_private(fio->page);
+
+	major = MAJOR(inode->i_sb->s_dev);
+	minor = MINOR(inode->i_sb->s_dev);
+
+	if (last_io.major == major && last_io.minor == minor &&
+			last_io.pid == pid &&
+			last_io.type == __file_type(inode, pid) &&
+			last_io.fio.op == fio->op &&
+			last_io.fio.op_flags == fio->op_flags &&
+			last_io.fio.new_blkaddr + last_io.len ==
+							fio->new_blkaddr) {
+		last_io.len++;
+		return;
+	}
+
+	__print_last_io();
+
+	last_io.major = major;
+	last_io.minor = minor;
+	last_io.pid = pid;
+	last_io.type = __file_type(inode, pid);
+	last_io.fio = *fio;
+	last_io.len = 1;
+	return;
+}
+
+void f2fs_build_trace_ios(void)
+{
+	spin_lock_init(&pids_lock);
+}
+
+#define PIDVEC_SIZE	128
+static unsigned int gang_lookup_pids(pid_t *results, unsigned long first_index,
+							unsigned int max_items)
+{
+	struct radix_tree_iter iter;
+	void **slot;
+	unsigned int ret = 0;
+
+	if (unlikely(!max_items))
+		return 0;
+
+	radix_tree_for_each_slot(slot, &pids, &iter, first_index) {
+		results[ret] = iter.index;
+		if (++ret == max_items)
+			break;
+	}
+	return ret;
+}
+
+void f2fs_destroy_trace_ios(void)
+{
+	pid_t pid[PIDVEC_SIZE];
+	pid_t next_pid = 0;
+	unsigned int found;
+
+	spin_lock(&pids_lock);
+	while ((found = gang_lookup_pids(pid, next_pid, PIDVEC_SIZE))) {
+		unsigned idx;
+
+		next_pid = pid[found - 1] + 1;
+		for (idx = 0; idx < found; idx++)
+			radix_tree_delete(&pids, pid[idx]);
+	}
+	spin_unlock(&pids_lock);
+}
diff --git a/src/kernel/linux/v4.14/fs/f2fs/trace.h b/src/kernel/linux/v4.14/fs/f2fs/trace.h
new file mode 100644
index 0000000..67db24a
--- /dev/null
+++ b/src/kernel/linux/v4.14/fs/f2fs/trace.h
@@ -0,0 +1,46 @@
+/*
+ * f2fs IO tracer
+ *
+ * Copyright (c) 2014 Motorola Mobility
+ * Copyright (c) 2014 Jaegeuk Kim <jaegeuk@kernel.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#ifndef __F2FS_TRACE_H__
+#define __F2FS_TRACE_H__
+
+#ifdef CONFIG_F2FS_IO_TRACE
+#include <trace/events/f2fs.h>
+
+enum file_type {
+	__NORMAL_FILE,
+	__DIR_FILE,
+	__NODE_FILE,
+	__META_FILE,
+	__ATOMIC_FILE,
+	__VOLATILE_FILE,
+	__MISC_FILE,
+};
+
+struct last_io_info {
+	int major, minor;
+	pid_t pid;
+	enum file_type type;
+	struct f2fs_io_info fio;
+	block_t len;
+};
+
+extern void f2fs_trace_pid(struct page *);
+extern void f2fs_trace_ios(struct f2fs_io_info *, int);
+extern void f2fs_build_trace_ios(void);
+extern void f2fs_destroy_trace_ios(void);
+#else
+#define f2fs_trace_pid(p)
+#define f2fs_trace_ios(i, n)
+#define f2fs_build_trace_ios()
+#define f2fs_destroy_trace_ios()
+
+#endif
+#endif /* __F2FS_TRACE_H__ */
diff --git a/src/kernel/linux/v4.14/fs/f2fs/xattr.c b/src/kernel/linux/v4.14/fs/f2fs/xattr.c
new file mode 100644
index 0000000..470d3fc
--- /dev/null
+++ b/src/kernel/linux/v4.14/fs/f2fs/xattr.c
@@ -0,0 +1,752 @@
+/*
+ * fs/f2fs/xattr.c
+ *
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ *             http://www.samsung.com/
+ *
+ * Portions of this code from linux/fs/ext2/xattr.c
+ *
+ * Copyright (C) 2001-2003 Andreas Gruenbacher <agruen@suse.de>
+ *
+ * Fix by Harrison Xing <harrison@mountainviewdata.com>.
+ * Extended attributes for symlinks and special files added per
+ *  suggestion of Luka Renko <luka.renko@hermes.si>.
+ * xattr consolidation Copyright (c) 2004 James Morris <jmorris@redhat.com>,
+ *  Red Hat Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/rwsem.h>
+#include <linux/f2fs_fs.h>
+#include <linux/security.h>
+#include <linux/posix_acl_xattr.h>
+#include "f2fs.h"
+#include "xattr.h"
+
+static int f2fs_xattr_generic_get(const struct xattr_handler *handler,
+		struct dentry *unused, struct inode *inode,
+		const char *name, void *buffer, size_t size)
+{
+	struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
+
+	switch (handler->flags) {
+	case F2FS_XATTR_INDEX_USER:
+		if (!test_opt(sbi, XATTR_USER))
+			return -EOPNOTSUPP;
+		break;
+	case F2FS_XATTR_INDEX_TRUSTED:
+		if (!capable(CAP_SYS_ADMIN))
+			return -EPERM;
+		break;
+	case F2FS_XATTR_INDEX_SECURITY:
+		break;
+	default:
+		return -EINVAL;
+	}
+	return f2fs_getxattr(inode, handler->flags, name,
+			     buffer, size, NULL);
+}
+
+static int f2fs_xattr_generic_set(const struct xattr_handler *handler,
+		struct dentry *unused, struct inode *inode,
+		const char *name, const void *value,
+		size_t size, int flags)
+{
+	struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
+
+	switch (handler->flags) {
+	case F2FS_XATTR_INDEX_USER:
+		if (!test_opt(sbi, XATTR_USER))
+			return -EOPNOTSUPP;
+		break;
+	case F2FS_XATTR_INDEX_TRUSTED:
+		if (!capable(CAP_SYS_ADMIN))
+			return -EPERM;
+		break;
+	case F2FS_XATTR_INDEX_SECURITY:
+		break;
+	default:
+		return -EINVAL;
+	}
+	return f2fs_setxattr(inode, handler->flags, name,
+					value, size, NULL, flags);
+}
+
+static bool f2fs_xattr_user_list(struct dentry *dentry)
+{
+	struct f2fs_sb_info *sbi = F2FS_SB(dentry->d_sb);
+
+	return test_opt(sbi, XATTR_USER);
+}
+
+static bool f2fs_xattr_trusted_list(struct dentry *dentry)
+{
+	return capable(CAP_SYS_ADMIN);
+}
+
+static int f2fs_xattr_advise_get(const struct xattr_handler *handler,
+		struct dentry *unused, struct inode *inode,
+		const char *name, void *buffer, size_t size)
+{
+	if (buffer)
+		*((char *)buffer) = F2FS_I(inode)->i_advise;
+	return sizeof(char);
+}
+
+static int f2fs_xattr_advise_set(const struct xattr_handler *handler,
+		struct dentry *unused, struct inode *inode,
+		const char *name, const void *value,
+		size_t size, int flags)
+{
+	if (!inode_owner_or_capable(inode))
+		return -EPERM;
+	if (value == NULL)
+		return -EINVAL;
+
+	F2FS_I(inode)->i_advise |= *(char *)value;
+	f2fs_mark_inode_dirty_sync(inode, true);
+	return 0;
+}
+
+#ifdef CONFIG_F2FS_FS_SECURITY
+static int f2fs_initxattrs(struct inode *inode, const struct xattr *xattr_array,
+		void *page)
+{
+	const struct xattr *xattr;
+	int err = 0;
+
+	for (xattr = xattr_array; xattr->name != NULL; xattr++) {
+		err = f2fs_setxattr(inode, F2FS_XATTR_INDEX_SECURITY,
+				xattr->name, xattr->value,
+				xattr->value_len, (struct page *)page, 0);
+		if (err < 0)
+			break;
+	}
+	return err;
+}
+
+int f2fs_init_security(struct inode *inode, struct inode *dir,
+				const struct qstr *qstr, struct page *ipage)
+{
+	return security_inode_init_security(inode, dir, qstr,
+				&f2fs_initxattrs, ipage);
+}
+#endif
+
+const struct xattr_handler f2fs_xattr_user_handler = {
+	.prefix	= XATTR_USER_PREFIX,
+	.flags	= F2FS_XATTR_INDEX_USER,
+	.list	= f2fs_xattr_user_list,
+	.get	= f2fs_xattr_generic_get,
+	.set	= f2fs_xattr_generic_set,
+};
+
+const struct xattr_handler f2fs_xattr_trusted_handler = {
+	.prefix	= XATTR_TRUSTED_PREFIX,
+	.flags	= F2FS_XATTR_INDEX_TRUSTED,
+	.list	= f2fs_xattr_trusted_list,
+	.get	= f2fs_xattr_generic_get,
+	.set	= f2fs_xattr_generic_set,
+};
+
+const struct xattr_handler f2fs_xattr_advise_handler = {
+	.name	= F2FS_SYSTEM_ADVISE_NAME,
+	.flags	= F2FS_XATTR_INDEX_ADVISE,
+	.get    = f2fs_xattr_advise_get,
+	.set    = f2fs_xattr_advise_set,
+};
+
+const struct xattr_handler f2fs_xattr_security_handler = {
+	.prefix	= XATTR_SECURITY_PREFIX,
+	.flags	= F2FS_XATTR_INDEX_SECURITY,
+	.get	= f2fs_xattr_generic_get,
+	.set	= f2fs_xattr_generic_set,
+};
+
+static const struct xattr_handler *f2fs_xattr_handler_map[] = {
+	[F2FS_XATTR_INDEX_USER] = &f2fs_xattr_user_handler,
+#ifdef CONFIG_F2FS_FS_POSIX_ACL
+	[F2FS_XATTR_INDEX_POSIX_ACL_ACCESS] = &posix_acl_access_xattr_handler,
+	[F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT] = &posix_acl_default_xattr_handler,
+#endif
+	[F2FS_XATTR_INDEX_TRUSTED] = &f2fs_xattr_trusted_handler,
+#ifdef CONFIG_F2FS_FS_SECURITY
+	[F2FS_XATTR_INDEX_SECURITY] = &f2fs_xattr_security_handler,
+#endif
+	[F2FS_XATTR_INDEX_ADVISE] = &f2fs_xattr_advise_handler,
+};
+
+const struct xattr_handler *f2fs_xattr_handlers[] = {
+	&f2fs_xattr_user_handler,
+#ifdef CONFIG_F2FS_FS_POSIX_ACL
+	&posix_acl_access_xattr_handler,
+	&posix_acl_default_xattr_handler,
+#endif
+	&f2fs_xattr_trusted_handler,
+#ifdef CONFIG_F2FS_FS_SECURITY
+	&f2fs_xattr_security_handler,
+#endif
+	&f2fs_xattr_advise_handler,
+	NULL,
+};
+
+static inline const struct xattr_handler *f2fs_xattr_handler(int index)
+{
+	const struct xattr_handler *handler = NULL;
+
+	if (index > 0 && index < ARRAY_SIZE(f2fs_xattr_handler_map))
+		handler = f2fs_xattr_handler_map[index];
+	return handler;
+}
+
+static struct f2fs_xattr_entry *__find_xattr(void *base_addr,
+				void *last_base_addr, int index,
+				size_t len, const char *name)
+{
+	struct f2fs_xattr_entry *entry;
+
+	list_for_each_xattr(entry, base_addr) {
+		if ((void *)(entry) + sizeof(__u32) > last_base_addr ||
+			(void *)XATTR_NEXT_ENTRY(entry) > last_base_addr)
+			return NULL;
+
+		if (entry->e_name_index != index)
+			continue;
+		if (entry->e_name_len != len)
+			continue;
+		if (!memcmp(entry->e_name, name, len))
+			break;
+	}
+	return entry;
+}
+
+static struct f2fs_xattr_entry *__find_inline_xattr(struct inode *inode,
+				void *base_addr, void **last_addr, int index,
+				size_t len, const char *name)
+{
+	struct f2fs_xattr_entry *entry;
+	unsigned int inline_size = inline_xattr_size(inode);
+
+	list_for_each_xattr(entry, base_addr) {
+		if ((void *)entry + sizeof(__u32) > base_addr + inline_size ||
+			(void *)XATTR_NEXT_ENTRY(entry) + sizeof(__u32) >
+			base_addr + inline_size) {
+			*last_addr = entry;
+			return NULL;
+		}
+		if (entry->e_name_index != index)
+			continue;
+		if (entry->e_name_len != len)
+			continue;
+		if (!memcmp(entry->e_name, name, len))
+			break;
+	}
+	return entry;
+}
+
+static int read_inline_xattr(struct inode *inode, struct page *ipage,
+							void *txattr_addr)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	unsigned int inline_size = inline_xattr_size(inode);
+	struct page *page = NULL;
+	void *inline_addr;
+
+	if (ipage) {
+		inline_addr = inline_xattr_addr(inode, ipage);
+	} else {
+		page = get_node_page(sbi, inode->i_ino);
+		if (IS_ERR(page))
+			return PTR_ERR(page);
+
+		inline_addr = inline_xattr_addr(inode, page);
+	}
+	memcpy(txattr_addr, inline_addr, inline_size);
+	f2fs_put_page(page, 1);
+
+	return 0;
+}
+
+static int read_xattr_block(struct inode *inode, void *txattr_addr)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	nid_t xnid = F2FS_I(inode)->i_xattr_nid;
+	unsigned int inline_size = inline_xattr_size(inode);
+	struct page *xpage;
+	void *xattr_addr;
+
+	/* The inode already has an extended attribute block. */
+	xpage = get_node_page(sbi, xnid);
+	if (IS_ERR(xpage))
+		return PTR_ERR(xpage);
+
+	xattr_addr = page_address(xpage);
+	memcpy(txattr_addr + inline_size, xattr_addr, VALID_XATTR_BLOCK_SIZE);
+	f2fs_put_page(xpage, 1);
+
+	return 0;
+}
+
+static int lookup_all_xattrs(struct inode *inode, struct page *ipage,
+				unsigned int index, unsigned int len,
+				const char *name, struct f2fs_xattr_entry **xe,
+				void **base_addr, int *base_size)
+{
+	void *cur_addr, *txattr_addr, *last_txattr_addr;
+	void *last_addr = NULL;
+	nid_t xnid = F2FS_I(inode)->i_xattr_nid;
+	unsigned int inline_size = inline_xattr_size(inode);
+	int err = 0;
+
+	if (!xnid && !inline_size)
+		return -ENODATA;
+
+	*base_size = XATTR_SIZE(xnid, inode) + XATTR_PADDING_SIZE;
+	txattr_addr = f2fs_kzalloc(F2FS_I_SB(inode), *base_size, GFP_NOFS);
+	if (!txattr_addr)
+		return -ENOMEM;
+
+	last_txattr_addr = (void *)txattr_addr + XATTR_SIZE(xnid, inode);
+
+	/* read from inline xattr */
+	if (inline_size) {
+		err = read_inline_xattr(inode, ipage, txattr_addr);
+		if (err)
+			goto out;
+
+		*xe = __find_inline_xattr(inode, txattr_addr, &last_addr,
+						index, len, name);
+		if (*xe) {
+			*base_size = inline_size;
+			goto check;
+		}
+	}
+
+	/* read from xattr node block */
+	if (xnid) {
+		err = read_xattr_block(inode, txattr_addr);
+		if (err)
+			goto out;
+	}
+
+	if (last_addr)
+		cur_addr = XATTR_HDR(last_addr) - 1;
+	else
+		cur_addr = txattr_addr;
+
+	*xe = __find_xattr(cur_addr, last_txattr_addr, index, len, name);
+	if (!*xe) {
+		err = -EFAULT;
+		goto out;
+	}
+check:
+	if (IS_XATTR_LAST_ENTRY(*xe)) {
+		err = -ENODATA;
+		goto out;
+	}
+
+	*base_addr = txattr_addr;
+	return 0;
+out:
+	kzfree(txattr_addr);
+	return err;
+}
+
+static int read_all_xattrs(struct inode *inode, struct page *ipage,
+							void **base_addr)
+{
+	struct f2fs_xattr_header *header;
+	nid_t xnid = F2FS_I(inode)->i_xattr_nid;
+	unsigned int size = VALID_XATTR_BLOCK_SIZE;
+	unsigned int inline_size = inline_xattr_size(inode);
+	void *txattr_addr;
+	int err;
+
+	txattr_addr = f2fs_kzalloc(F2FS_I_SB(inode),
+			inline_size + size + XATTR_PADDING_SIZE, GFP_NOFS);
+	if (!txattr_addr)
+		return -ENOMEM;
+
+	/* read from inline xattr */
+	if (inline_size) {
+		err = read_inline_xattr(inode, ipage, txattr_addr);
+		if (err)
+			goto fail;
+	}
+
+	/* read from xattr node block */
+	if (xnid) {
+		err = read_xattr_block(inode, txattr_addr);
+		if (err)
+			goto fail;
+	}
+
+	header = XATTR_HDR(txattr_addr);
+
+	/* never been allocated xattrs */
+	if (le32_to_cpu(header->h_magic) != F2FS_XATTR_MAGIC) {
+		header->h_magic = cpu_to_le32(F2FS_XATTR_MAGIC);
+		header->h_refcount = cpu_to_le32(1);
+	}
+	*base_addr = txattr_addr;
+	return 0;
+fail:
+	kzfree(txattr_addr);
+	return err;
+}
+
+static inline int write_all_xattrs(struct inode *inode, __u32 hsize,
+				void *txattr_addr, struct page *ipage)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	size_t inline_size = inline_xattr_size(inode);
+	struct page *in_page = NULL;
+	void *xattr_addr;
+	void *inline_addr = NULL;
+	struct page *xpage;
+	nid_t new_nid = 0;
+	int err = 0;
+
+	if (hsize > inline_size && !F2FS_I(inode)->i_xattr_nid)
+		if (!alloc_nid(sbi, &new_nid))
+			return -ENOSPC;
+
+	/* write to inline xattr */
+	if (inline_size) {
+		if (ipage) {
+			inline_addr = inline_xattr_addr(inode, ipage);
+		} else {
+			in_page = get_node_page(sbi, inode->i_ino);
+			if (IS_ERR(in_page)) {
+				alloc_nid_failed(sbi, new_nid);
+				return PTR_ERR(in_page);
+			}
+			inline_addr = inline_xattr_addr(inode, in_page);
+		}
+
+		f2fs_wait_on_page_writeback(ipage ? ipage : in_page,
+							NODE, true);
+		/* no need to use xattr node block */
+		if (hsize <= inline_size) {
+			err = truncate_xattr_node(inode);
+			alloc_nid_failed(sbi, new_nid);
+			if (err) {
+				f2fs_put_page(in_page, 1);
+				return err;
+			}
+			memcpy(inline_addr, txattr_addr, inline_size);
+			set_page_dirty(ipage ? ipage : in_page);
+			goto in_page_out;
+		}
+	}
+
+	/* write to xattr node block */
+	if (F2FS_I(inode)->i_xattr_nid) {
+		xpage = get_node_page(sbi, F2FS_I(inode)->i_xattr_nid);
+		if (IS_ERR(xpage)) {
+			err = PTR_ERR(xpage);
+			alloc_nid_failed(sbi, new_nid);
+			goto in_page_out;
+		}
+		f2fs_bug_on(sbi, new_nid);
+		f2fs_wait_on_page_writeback(xpage, NODE, true);
+	} else {
+		struct dnode_of_data dn;
+		set_new_dnode(&dn, inode, NULL, NULL, new_nid);
+		xpage = new_node_page(&dn, XATTR_NODE_OFFSET);
+		if (IS_ERR(xpage)) {
+			err = PTR_ERR(xpage);
+			alloc_nid_failed(sbi, new_nid);
+			goto in_page_out;
+		}
+		alloc_nid_done(sbi, new_nid);
+	}
+	xattr_addr = page_address(xpage);
+
+	if (inline_size)
+		memcpy(inline_addr, txattr_addr, inline_size);
+	memcpy(xattr_addr, txattr_addr + inline_size, VALID_XATTR_BLOCK_SIZE);
+
+	if (inline_size)
+		set_page_dirty(ipage ? ipage : in_page);
+	set_page_dirty(xpage);
+
+	f2fs_put_page(xpage, 1);
+in_page_out:
+	f2fs_put_page(in_page, 1);
+	return err;
+}
+
+int f2fs_getxattr(struct inode *inode, int index, const char *name,
+		void *buffer, size_t buffer_size, struct page *ipage)
+{
+	struct f2fs_xattr_entry *entry = NULL;
+	int error = 0;
+	unsigned int size, len;
+	void *base_addr = NULL;
+	int base_size;
+
+	if (name == NULL)
+		return -EINVAL;
+
+	len = strlen(name);
+	if (len > F2FS_NAME_LEN)
+		return -ERANGE;
+
+	down_read(&F2FS_I(inode)->i_xattr_sem);
+	error = lookup_all_xattrs(inode, ipage, index, len, name,
+				&entry, &base_addr, &base_size);
+	up_read(&F2FS_I(inode)->i_xattr_sem);
+	if (error)
+		return error;
+
+	size = le16_to_cpu(entry->e_value_size);
+
+	if (buffer && size > buffer_size) {
+		error = -ERANGE;
+		goto out;
+	}
+
+	if (buffer) {
+		char *pval = entry->e_name + entry->e_name_len;
+
+		if (base_size - (pval - (char *)base_addr) < size) {
+			error = -ERANGE;
+			goto out;
+		}
+		memcpy(buffer, pval, size);
+	}
+	error = size;
+out:
+	kzfree(base_addr);
+	return error;
+}
+
+ssize_t f2fs_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size)
+{
+	struct inode *inode = d_inode(dentry);
+	nid_t xnid = F2FS_I(inode)->i_xattr_nid;
+	struct f2fs_xattr_entry *entry;
+	void *base_addr, *last_base_addr;
+	int error = 0;
+	size_t rest = buffer_size;
+
+	down_read(&F2FS_I(inode)->i_xattr_sem);
+	error = read_all_xattrs(inode, NULL, &base_addr);
+	up_read(&F2FS_I(inode)->i_xattr_sem);
+	if (error)
+		return error;
+
+	last_base_addr = (void *)base_addr + XATTR_SIZE(xnid, inode);
+
+	list_for_each_xattr(entry, base_addr) {
+		const struct xattr_handler *handler =
+			f2fs_xattr_handler(entry->e_name_index);
+		const char *prefix;
+		size_t prefix_len;
+		size_t size;
+
+		if ((void *)(entry) + sizeof(__u32) > last_base_addr ||
+			(void *)XATTR_NEXT_ENTRY(entry) > last_base_addr) {
+			f2fs_msg(dentry->d_sb, KERN_ERR,
+				 "inode (%lu) has corrupted xattr",
+				 inode->i_ino);
+			set_sbi_flag(F2FS_I_SB(inode), SBI_NEED_FSCK);
+			error = -EFSCORRUPTED;
+			goto cleanup;
+		}
+
+		if (!handler || (handler->list && !handler->list(dentry)))
+			continue;
+
+		prefix = handler->prefix ?: handler->name;
+		prefix_len = strlen(prefix);
+		size = prefix_len + entry->e_name_len + 1;
+		if (buffer) {
+			if (size > rest) {
+				error = -ERANGE;
+				goto cleanup;
+			}
+			memcpy(buffer, prefix, prefix_len);
+			buffer += prefix_len;
+			memcpy(buffer, entry->e_name, entry->e_name_len);
+			buffer += entry->e_name_len;
+			*buffer++ = 0;
+		}
+		rest -= size;
+	}
+	error = buffer_size - rest;
+cleanup:
+	kzfree(base_addr);
+	return error;
+}
+
+static bool f2fs_xattr_value_same(struct f2fs_xattr_entry *entry,
+					const void *value, size_t size)
+{
+	void *pval = entry->e_name + entry->e_name_len;
+
+	return (le16_to_cpu(entry->e_value_size) == size) &&
+					!memcmp(pval, value, size);
+}
+
+static int __f2fs_setxattr(struct inode *inode, int index,
+			const char *name, const void *value, size_t size,
+			struct page *ipage, int flags)
+{
+	struct f2fs_xattr_entry *here, *last;
+	void *base_addr, *last_base_addr;
+	nid_t xnid = F2FS_I(inode)->i_xattr_nid;
+	int found, newsize;
+	size_t len;
+	__u32 new_hsize;
+	int error = 0;
+
+	if (name == NULL)
+		return -EINVAL;
+
+	if (value == NULL)
+		size = 0;
+
+	len = strlen(name);
+
+	if (len > F2FS_NAME_LEN)
+		return -ERANGE;
+
+	if (size > MAX_VALUE_LEN(inode))
+		return -E2BIG;
+
+	error = read_all_xattrs(inode, ipage, &base_addr);
+	if (error)
+		return error;
+
+	last_base_addr = (void *)base_addr + XATTR_SIZE(xnid, inode);
+
+	/* find entry with wanted name. */
+	here = __find_xattr(base_addr, last_base_addr, index, len, name);
+	if (!here) {
+		error = -EFAULT;
+		goto exit;
+	}
+
+	found = IS_XATTR_LAST_ENTRY(here) ? 0 : 1;
+
+	if (found) {
+		if ((flags & XATTR_CREATE)) {
+			error = -EEXIST;
+			goto exit;
+		}
+
+		if (value && f2fs_xattr_value_same(here, value, size))
+			goto exit;
+	} else if ((flags & XATTR_REPLACE)) {
+		error = -ENODATA;
+		goto exit;
+	}
+
+	last = here;
+	while (!IS_XATTR_LAST_ENTRY(last))
+		last = XATTR_NEXT_ENTRY(last);
+
+	newsize = XATTR_ALIGN(sizeof(struct f2fs_xattr_entry) + len + size);
+
+	/* 1. Check space */
+	if (value) {
+		int free;
+		/*
+		 * If value is NULL, it is remove operation.
+		 * In case of update operation, we calculate free.
+		 */
+		free = MIN_OFFSET(inode) - ((char *)last - (char *)base_addr);
+		if (found)
+			free = free + ENTRY_SIZE(here);
+
+		if (unlikely(free < newsize)) {
+			error = -E2BIG;
+			goto exit;
+		}
+	}
+
+	/* 2. Remove old entry */
+	if (found) {
+		/*
+		 * If entry is found, remove old entry.
+		 * If not found, remove operation is not needed.
+		 */
+		struct f2fs_xattr_entry *next = XATTR_NEXT_ENTRY(here);
+		int oldsize = ENTRY_SIZE(here);
+
+		memmove(here, next, (char *)last - (char *)next);
+		last = (struct f2fs_xattr_entry *)((char *)last - oldsize);
+		memset(last, 0, oldsize);
+	}
+
+	new_hsize = (char *)last - (char *)base_addr;
+
+	/* 3. Write new entry */
+	if (value) {
+		char *pval;
+		/*
+		 * Before we come here, old entry is removed.
+		 * We just write new entry.
+		 */
+		last->e_name_index = index;
+		last->e_name_len = len;
+		memcpy(last->e_name, name, len);
+		pval = last->e_name + len;
+		memcpy(pval, value, size);
+		last->e_value_size = cpu_to_le16(size);
+		new_hsize += newsize;
+	}
+
+	error = write_all_xattrs(inode, new_hsize, base_addr, ipage);
+	if (error)
+		goto exit;
+
+	if (is_inode_flag_set(inode, FI_ACL_MODE)) {
+		inode->i_mode = F2FS_I(inode)->i_acl_mode;
+		inode->i_ctime = current_time(inode);
+		clear_inode_flag(inode, FI_ACL_MODE);
+	}
+	if (index == F2FS_XATTR_INDEX_ENCRYPTION &&
+			!strcmp(name, F2FS_XATTR_NAME_ENCRYPTION_CONTEXT))
+		f2fs_set_encrypted_inode(inode);
+	f2fs_mark_inode_dirty_sync(inode, true);
+	if (!error && S_ISDIR(inode->i_mode))
+		set_sbi_flag(F2FS_I_SB(inode), SBI_NEED_CP);
+exit:
+	kzfree(base_addr);
+	return error;
+}
+
+int f2fs_setxattr(struct inode *inode, int index, const char *name,
+				const void *value, size_t size,
+				struct page *ipage, int flags)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	int err;
+
+	err = dquot_initialize(inode);
+	if (err)
+		return err;
+
+	/* this case is only from init_inode_metadata */
+	if (ipage)
+		return __f2fs_setxattr(inode, index, name, value,
+						size, ipage, flags);
+	f2fs_balance_fs(sbi, true);
+
+	f2fs_lock_op(sbi);
+	/* protect xattr_ver */
+	down_write(&F2FS_I(inode)->i_sem);
+	down_write(&F2FS_I(inode)->i_xattr_sem);
+	err = __f2fs_setxattr(inode, index, name, value, size, ipage, flags);
+	up_write(&F2FS_I(inode)->i_xattr_sem);
+	up_write(&F2FS_I(inode)->i_sem);
+	f2fs_unlock_op(sbi);
+
+	f2fs_update_time(sbi, REQ_TIME);
+	return err;
+}
diff --git a/src/kernel/linux/v4.14/fs/f2fs/xattr.h b/src/kernel/linux/v4.14/fs/f2fs/xattr.h
new file mode 100644
index 0000000..2a4ecaf
--- /dev/null
+++ b/src/kernel/linux/v4.14/fs/f2fs/xattr.h
@@ -0,0 +1,160 @@
+/*
+ * fs/f2fs/xattr.h
+ *
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ *             http://www.samsung.com/
+ *
+ * Portions of this code from linux/fs/ext2/xattr.h
+ *
+ * On-disk format of extended attributes for the ext2 filesystem.
+ *
+ * (C) 2001 Andreas Gruenbacher, <a.gruenbacher@computer.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#ifndef __F2FS_XATTR_H__
+#define __F2FS_XATTR_H__
+
+#include <linux/init.h>
+#include <linux/xattr.h>
+
+/* Magic value in attribute blocks */
+#define F2FS_XATTR_MAGIC                0xF2F52011
+
+/* Maximum number of references to one attribute block */
+#define F2FS_XATTR_REFCOUNT_MAX         1024
+
+/* Name indexes */
+#define F2FS_SYSTEM_ADVISE_NAME			"system.advise"
+#define F2FS_XATTR_INDEX_USER			1
+#define F2FS_XATTR_INDEX_POSIX_ACL_ACCESS	2
+#define F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT	3
+#define F2FS_XATTR_INDEX_TRUSTED		4
+#define F2FS_XATTR_INDEX_LUSTRE			5
+#define F2FS_XATTR_INDEX_SECURITY		6
+#define F2FS_XATTR_INDEX_ADVISE			7
+/* Should be same as EXT4_XATTR_INDEX_ENCRYPTION */
+#define F2FS_XATTR_INDEX_ENCRYPTION		9
+
+#define F2FS_XATTR_NAME_ENCRYPTION_CONTEXT	"c"
+
+struct f2fs_xattr_header {
+	__le32  h_magic;        /* magic number for identification */
+	__le32  h_refcount;     /* reference count */
+	__u32   h_reserved[4];  /* zero right now */
+};
+
+struct f2fs_xattr_entry {
+	__u8    e_name_index;
+	__u8    e_name_len;
+	__le16  e_value_size;   /* size of attribute value */
+	char    e_name[0];      /* attribute name */
+};
+
+#define XATTR_HDR(ptr)		((struct f2fs_xattr_header *)(ptr))
+#define XATTR_ENTRY(ptr)	((struct f2fs_xattr_entry *)(ptr))
+#define XATTR_FIRST_ENTRY(ptr)	(XATTR_ENTRY(XATTR_HDR(ptr) + 1))
+#define XATTR_ROUND		(3)
+
+#define XATTR_ALIGN(size)	(((size) + XATTR_ROUND) & ~XATTR_ROUND)
+
+#define ENTRY_SIZE(entry) (XATTR_ALIGN(sizeof(struct f2fs_xattr_entry) + \
+			(entry)->e_name_len + le16_to_cpu((entry)->e_value_size)))
+
+#define XATTR_NEXT_ENTRY(entry)	((struct f2fs_xattr_entry *)((char *)(entry) +\
+			ENTRY_SIZE(entry)))
+
+#define IS_XATTR_LAST_ENTRY(entry) (*(__u32 *)(entry) == 0)
+
+#define list_for_each_xattr(entry, addr) \
+		for (entry = XATTR_FIRST_ENTRY(addr);\
+				!IS_XATTR_LAST_ENTRY(entry);\
+				entry = XATTR_NEXT_ENTRY(entry))
+#define VALID_XATTR_BLOCK_SIZE	(PAGE_SIZE - sizeof(struct node_footer))
+#define XATTR_PADDING_SIZE	(sizeof(__u32))
+#define XATTR_SIZE(x,i)		(((x) ? VALID_XATTR_BLOCK_SIZE : 0) +	\
+						(inline_xattr_size(i)))
+#define MIN_OFFSET(i)		XATTR_ALIGN(inline_xattr_size(i) +	\
+						VALID_XATTR_BLOCK_SIZE)
+
+#define MAX_VALUE_LEN(i)	(MIN_OFFSET(i) -			\
+				sizeof(struct f2fs_xattr_header) -	\
+				sizeof(struct f2fs_xattr_entry))
+
+/*
+ * On-disk structure of f2fs_xattr
+ * We use inline xattrs space + 1 block for xattr.
+ *
+ * +--------------------+
+ * | f2fs_xattr_header  |
+ * |                    |
+ * +--------------------+
+ * | f2fs_xattr_entry   |
+ * | .e_name_index = 1  |
+ * | .e_name_len = 3    |
+ * | .e_value_size = 14 |
+ * | .e_name = "foo"    |
+ * | "value_of_xattr"   |<- value_offs = e_name + e_name_len
+ * +--------------------+
+ * | f2fs_xattr_entry   |
+ * | .e_name_index = 4  |
+ * | .e_name = "bar"    |
+ * +--------------------+
+ * |                    |
+ * |        Free        |
+ * |                    |
+ * +--------------------+<- MIN_OFFSET
+ * |   node_footer      |
+ * | (nid, ino, offset) |
+ * +--------------------+
+ *
+ **/
+
+#ifdef CONFIG_F2FS_FS_XATTR
+extern const struct xattr_handler f2fs_xattr_user_handler;
+extern const struct xattr_handler f2fs_xattr_trusted_handler;
+extern const struct xattr_handler f2fs_xattr_advise_handler;
+extern const struct xattr_handler f2fs_xattr_security_handler;
+
+extern const struct xattr_handler *f2fs_xattr_handlers[];
+
+extern int f2fs_setxattr(struct inode *, int, const char *,
+				const void *, size_t, struct page *, int);
+extern int f2fs_getxattr(struct inode *, int, const char *, void *,
+						size_t, struct page *);
+extern ssize_t f2fs_listxattr(struct dentry *, char *, size_t);
+#else
+
+#define f2fs_xattr_handlers	NULL
+static inline int f2fs_setxattr(struct inode *inode, int index,
+		const char *name, const void *value, size_t size,
+		struct page *page, int flags)
+{
+	return -EOPNOTSUPP;
+}
+static inline int f2fs_getxattr(struct inode *inode, int index,
+			const char *name, void *buffer,
+			size_t buffer_size, struct page *dpage)
+{
+	return -EOPNOTSUPP;
+}
+static inline ssize_t f2fs_listxattr(struct dentry *dentry, char *buffer,
+		size_t buffer_size)
+{
+	return -EOPNOTSUPP;
+}
+#endif
+
+#ifdef CONFIG_F2FS_FS_SECURITY
+extern int f2fs_init_security(struct inode *, struct inode *,
+				const struct qstr *, struct page *);
+#else
+static inline int f2fs_init_security(struct inode *inode, struct inode *dir,
+				const struct qstr *qstr, struct page *ipage)
+{
+	return 0;
+}
+#endif
+#endif /* __F2FS_XATTR_H__ */