ASR_BASE

Change-Id: Icf3719cc0afe3eeb3edc7fa80a2eb5199ca9dda1
diff --git a/marvell/linux/fs/incfs/pseudo_files.c b/marvell/linux/fs/incfs/pseudo_files.c
new file mode 100644
index 0000000..d43ccb2
--- /dev/null
+++ b/marvell/linux/fs/incfs/pseudo_files.c
@@ -0,0 +1,1391 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2020 Google LLC
+ */
+
+#include <linux/file.h>
+#include <linux/fs.h>
+#include <linux/fsnotify.h>
+#include <linux/namei.h>
+#include <linux/poll.h>
+#include <linux/syscalls.h>
+
+#include <uapi/linux/incrementalfs.h>
+
+#include "pseudo_files.h"
+
+#include "data_mgmt.h"
+#include "format.h"
+#include "integrity.h"
+#include "vfs.h"
+
+#define READ_WRITE_FILE_MODE 0666
+
+static bool is_pseudo_filename(struct mem_range name);
+
+/*******************************************************************************
+ * .pending_reads pseudo file definition
+ ******************************************************************************/
+#define INCFS_PENDING_READS_INODE 2
+static const char pending_reads_file_name[] = INCFS_PENDING_READS_FILENAME;
+
+/* State of an open .pending_reads file, unique for each file descriptor. */
+struct pending_reads_state {
+	/* A serial number of the last pending read obtained from this file. */
+	int last_pending_read_sn;
+};
+
+static ssize_t pending_reads_read(struct file *f, char __user *buf, size_t len,
+			    loff_t *ppos)
+{
+	struct pending_reads_state *pr_state = f->private_data;
+	struct mount_info *mi = get_mount_info(file_superblock(f));
+	bool report_uid;
+	unsigned long page = 0;
+	struct incfs_pending_read_info *reads_buf = NULL;
+	struct incfs_pending_read_info2 *reads_buf2 = NULL;
+	size_t record_size;
+	size_t reads_to_collect;
+	int last_known_read_sn = READ_ONCE(pr_state->last_pending_read_sn);
+	int new_max_sn = last_known_read_sn;
+	int reads_collected = 0;
+	ssize_t result = 0;
+
+	if (!mi)
+		return -EFAULT;
+
+	report_uid = mi->mi_options.report_uid;
+	record_size = report_uid ? sizeof(*reads_buf2) : sizeof(*reads_buf);
+	reads_to_collect = len / record_size;
+
+	if (!incfs_fresh_pending_reads_exist(mi, last_known_read_sn))
+		return 0;
+
+	page = get_zeroed_page(GFP_NOFS);
+	if (!page)
+		return -ENOMEM;
+
+	if (report_uid)
+		reads_buf2 = (struct incfs_pending_read_info2 *) page;
+	else
+		reads_buf = (struct incfs_pending_read_info *) page;
+
+	reads_to_collect =
+		min_t(size_t, PAGE_SIZE / record_size, reads_to_collect);
+
+	reads_collected = incfs_collect_pending_reads(mi, last_known_read_sn,
+				reads_buf, reads_buf2, reads_to_collect,
+				&new_max_sn);
+
+	if (reads_collected < 0) {
+		result = reads_collected;
+		goto out;
+	}
+
+	/*
+	 * Just to make sure that we don't accidentally copy more data
+	 * to reads buffer than userspace can handle.
+	 */
+	reads_collected = min_t(size_t, reads_collected, reads_to_collect);
+	result = reads_collected * record_size;
+
+	/* Copy reads info to the userspace buffer */
+	if (copy_to_user(buf, (void *)page, result)) {
+		result = -EFAULT;
+		goto out;
+	}
+
+	WRITE_ONCE(pr_state->last_pending_read_sn, new_max_sn);
+	*ppos = 0;
+
+out:
+	free_page(page);
+	return result;
+}
+
+static __poll_t pending_reads_poll(struct file *file, poll_table *wait)
+{
+	struct pending_reads_state *state = file->private_data;
+	struct mount_info *mi = get_mount_info(file_superblock(file));
+	__poll_t ret = 0;
+
+	poll_wait(file, &mi->mi_pending_reads_notif_wq, wait);
+	if (incfs_fresh_pending_reads_exist(mi,
+					    state->last_pending_read_sn))
+		ret = EPOLLIN | EPOLLRDNORM;
+
+	return ret;
+}
+
+static int pending_reads_open(struct inode *inode, struct file *file)
+{
+	struct pending_reads_state *state = NULL;
+
+	state = kzalloc(sizeof(*state), GFP_NOFS);
+	if (!state)
+		return -ENOMEM;
+
+	file->private_data = state;
+	return 0;
+}
+
+static int pending_reads_release(struct inode *inode, struct file *file)
+{
+	kfree(file->private_data);
+	return 0;
+}
+
+static long ioctl_permit_fill(struct file *f, void __user *arg)
+{
+	struct incfs_permit_fill __user *usr_permit_fill = arg;
+	struct incfs_permit_fill permit_fill;
+	long error = 0;
+	struct file *file = NULL;
+	struct incfs_file_data *fd;
+
+	if (copy_from_user(&permit_fill, usr_permit_fill, sizeof(permit_fill)))
+		return -EFAULT;
+
+	file = fget(permit_fill.file_descriptor);
+	if (IS_ERR_OR_NULL(file)) {
+		if (!file)
+			return -ENOENT;
+
+		return PTR_ERR(file);
+	}
+
+	if (file->f_op != &incfs_file_ops) {
+		error = -EPERM;
+		goto out;
+	}
+
+	if (file->f_inode->i_sb != f->f_inode->i_sb) {
+		error = -EPERM;
+		goto out;
+	}
+
+	fd = file->private_data;
+
+	switch (fd->fd_fill_permission) {
+	case CANT_FILL:
+		fd->fd_fill_permission = CAN_FILL;
+		break;
+
+	case CAN_FILL:
+		pr_debug("CAN_FILL already set");
+		break;
+
+	default:
+		pr_warn("Invalid file private data");
+		error = -EFAULT;
+		goto out;
+	}
+
+out:
+	fput(file);
+	return error;
+}
+
+static int chmod(struct dentry *dentry, umode_t mode)
+{
+	struct inode *inode = dentry->d_inode;
+	struct inode *delegated_inode = NULL;
+	struct iattr newattrs;
+	int error;
+
+retry_deleg:
+	inode_lock(inode);
+	newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO);
+	newattrs.ia_valid = ATTR_MODE | ATTR_CTIME;
+	error = notify_change(dentry, &newattrs, &delegated_inode);
+	inode_unlock(inode);
+	if (delegated_inode) {
+		error = break_deleg_wait(&delegated_inode);
+		if (!error)
+			goto retry_deleg;
+	}
+	return error;
+}
+
+static bool incfs_equal_ranges(struct mem_range lhs, struct mem_range rhs)
+{
+	if (lhs.len != rhs.len)
+		return false;
+	return memcmp(lhs.data, rhs.data, lhs.len) == 0;
+}
+
+static int validate_name(char *file_name)
+{
+	struct mem_range name = range(file_name, strlen(file_name));
+	int i = 0;
+
+	if (name.len > INCFS_MAX_NAME_LEN)
+		return -ENAMETOOLONG;
+
+	if (is_pseudo_filename(name))
+		return -EINVAL;
+
+	for (i = 0; i < name.len; i++)
+		if (name.data[i] == '/')
+			return -EINVAL;
+
+	return 0;
+}
+
+static int dir_relative_path_resolve(
+			struct mount_info *mi,
+			const char __user *relative_path,
+			struct path *result_path,
+			struct path *base_path)
+{
+	int dir_fd = get_unused_fd_flags(0);
+	struct file *dir_f = NULL;
+	int error = 0;
+
+	if (!base_path)
+		base_path = &mi->mi_backing_dir_path;
+
+	if (dir_fd < 0)
+		return dir_fd;
+
+	dir_f = dentry_open(base_path, O_RDONLY | O_NOATIME, current_cred());
+
+	if (IS_ERR(dir_f)) {
+		error = PTR_ERR(dir_f);
+		goto out;
+	}
+	fd_install(dir_fd, dir_f);
+
+	if (!relative_path) {
+		/* No relative path given, just return the base dir. */
+		*result_path = *base_path;
+		path_get(result_path);
+		goto out;
+	}
+
+	error = user_path_at_empty(dir_fd, relative_path,
+		LOOKUP_FOLLOW | LOOKUP_DIRECTORY, result_path, NULL);
+
+out:
+	ksys_close(dir_fd);
+	if (error)
+		pr_debug("Error: %d\n", error);
+	return error;
+}
+
+static struct mem_range incfs_copy_signature_info_from_user(u8 __user *original,
+							    u64 size)
+{
+	u8 *result;
+
+	if (!original)
+		return range(NULL, 0);
+
+	if (size > INCFS_MAX_SIGNATURE_SIZE)
+		return range(ERR_PTR(-EFAULT), 0);
+
+	result = kzalloc(size, GFP_NOFS | __GFP_COMP);
+	if (!result)
+		return range(ERR_PTR(-ENOMEM), 0);
+
+	if (copy_from_user(result, original, size)) {
+		kfree(result);
+		return range(ERR_PTR(-EFAULT), 0);
+	}
+
+	return range(result, size);
+}
+
+static int init_new_file(struct mount_info *mi, struct dentry *dentry,
+			 incfs_uuid_t *uuid, u64 size, struct mem_range attr,
+			 u8 __user *user_signature_info, u64 signature_size)
+{
+	struct path path = {};
+	struct file *new_file;
+	int error = 0;
+	struct backing_file_context *bfc = NULL;
+	u32 block_count;
+	struct mem_range raw_signature = { NULL };
+	struct mtree *hash_tree = NULL;
+
+	if (!mi || !dentry || !uuid)
+		return -EFAULT;
+
+	/* Resize newly created file to its true size. */
+	path = (struct path) {
+		.mnt = mi->mi_backing_dir_path.mnt,
+		.dentry = dentry
+	};
+
+	new_file = dentry_open(&path, O_RDWR | O_NOATIME | O_LARGEFILE,
+			       current_cred());
+
+	if (IS_ERR(new_file)) {
+		error = PTR_ERR(new_file);
+		goto out;
+	}
+
+	bfc = incfs_alloc_bfc(mi, new_file);
+	fput(new_file);
+	if (IS_ERR(bfc)) {
+		error = PTR_ERR(bfc);
+		bfc = NULL;
+		goto out;
+	}
+
+	mutex_lock(&bfc->bc_mutex);
+	error = incfs_write_fh_to_backing_file(bfc, uuid, size);
+	if (error)
+		goto out;
+
+	block_count = (u32)get_blocks_count_for_size(size);
+
+	if (user_signature_info) {
+		raw_signature = incfs_copy_signature_info_from_user(
+			user_signature_info, signature_size);
+
+		if (IS_ERR(raw_signature.data)) {
+			error = PTR_ERR(raw_signature.data);
+			raw_signature.data = NULL;
+			goto out;
+		}
+
+		hash_tree = incfs_alloc_mtree(raw_signature, block_count);
+		if (IS_ERR(hash_tree)) {
+			error = PTR_ERR(hash_tree);
+			hash_tree = NULL;
+			goto out;
+		}
+
+		error = incfs_write_signature_to_backing_file(bfc,
+				raw_signature, hash_tree->hash_tree_area_size,
+				NULL, NULL);
+		if (error)
+			goto out;
+
+		block_count += get_blocks_count_for_size(
+			hash_tree->hash_tree_area_size);
+	}
+
+	if (block_count)
+		error = incfs_write_blockmap_to_backing_file(bfc, block_count);
+
+	if (error)
+		goto out;
+
+out:
+	if (bfc) {
+		mutex_unlock(&bfc->bc_mutex);
+		incfs_free_bfc(bfc);
+	}
+	incfs_free_mtree(hash_tree);
+	kfree(raw_signature.data);
+
+	if (error)
+		pr_debug("incfs: %s error: %d\n", __func__, error);
+	return error;
+}
+
+static void notify_create(struct file *pending_reads_file,
+			  const char  __user *dir_name, const char *file_name,
+			  const char *file_id_str, bool incomplete_file)
+{
+	struct mount_info *mi =
+		get_mount_info(file_superblock(pending_reads_file));
+	struct path base_path = {
+		.mnt = pending_reads_file->f_path.mnt,
+		.dentry = pending_reads_file->f_path.dentry->d_parent,
+	};
+	struct path dir_path = {};
+	struct dentry *file = NULL;
+	struct dentry *dir = NULL;
+	int error;
+
+	error = dir_relative_path_resolve(mi, dir_name, &dir_path, &base_path);
+	if (error)
+		goto out;
+
+	file = incfs_lookup_dentry(dir_path.dentry, file_name);
+	if (IS_ERR(file)) {
+		error = PTR_ERR(file);
+		file = NULL;
+		goto out;
+	}
+
+	fsnotify_create(d_inode(dir_path.dentry), file);
+
+	if (file_id_str) {
+		dir = incfs_lookup_dentry(base_path.dentry, INCFS_INDEX_NAME);
+		if (IS_ERR(dir)) {
+			error = PTR_ERR(dir);
+			dir = NULL;
+			goto out;
+		}
+
+		dput(file);
+		file = incfs_lookup_dentry(dir, file_id_str);
+		if (IS_ERR(file)) {
+			error = PTR_ERR(file);
+			file = NULL;
+			goto out;
+		}
+
+		fsnotify_create(d_inode(dir), file);
+
+		if (incomplete_file) {
+			dput(dir);
+			dir = incfs_lookup_dentry(base_path.dentry,
+						  INCFS_INCOMPLETE_NAME);
+			if (IS_ERR(dir)) {
+				error = PTR_ERR(dir);
+				dir = NULL;
+				goto out;
+			}
+
+			dput(file);
+			file = incfs_lookup_dentry(dir, file_id_str);
+			if (IS_ERR(file)) {
+				error = PTR_ERR(file);
+				file = NULL;
+				goto out;
+			}
+
+			fsnotify_create(d_inode(dir), file);
+		}
+	}
+out:
+	if (error)
+		pr_warn("%s failed with error %d\n", __func__, error);
+
+	dput(dir);
+	dput(file);
+	path_put(&dir_path);
+}
+
+static long ioctl_create_file(struct file *file,
+			struct incfs_new_file_args __user *usr_args)
+{
+	struct mount_info *mi = get_mount_info(file_superblock(file));
+	struct incfs_new_file_args args;
+	char *file_id_str = NULL;
+	struct dentry *index_file_dentry = NULL;
+	struct dentry *named_file_dentry = NULL;
+	struct dentry *incomplete_file_dentry = NULL;
+	struct path parent_dir_path = {};
+	struct inode *index_dir_inode = NULL;
+	__le64 size_attr_value = 0;
+	char *file_name = NULL;
+	char *attr_value = NULL;
+	int error = 0;
+	bool locked = false;
+	bool index_linked = false;
+	bool name_linked = false;
+	bool incomplete_linked = false;
+
+	if (!mi || !mi->mi_index_dir || !mi->mi_incomplete_dir) {
+		error = -EFAULT;
+		goto out;
+	}
+
+	if (copy_from_user(&args, usr_args, sizeof(args)) > 0) {
+		error = -EFAULT;
+		goto out;
+	}
+
+	file_name = strndup_user(u64_to_user_ptr(args.file_name), PATH_MAX);
+	if (IS_ERR(file_name)) {
+		error = PTR_ERR(file_name);
+		file_name = NULL;
+		goto out;
+	}
+
+	error = validate_name(file_name);
+	if (error)
+		goto out;
+
+	file_id_str = file_id_to_str(args.file_id);
+	if (!file_id_str) {
+		error = -ENOMEM;
+		goto out;
+	}
+
+	error = mutex_lock_interruptible(&mi->mi_dir_struct_mutex);
+	if (error)
+		goto out;
+	locked = true;
+
+	/* Find a directory to put the file into. */
+	error = dir_relative_path_resolve(mi,
+			u64_to_user_ptr(args.directory_path),
+			&parent_dir_path, NULL);
+	if (error)
+		goto out;
+
+	if (parent_dir_path.dentry == mi->mi_index_dir) {
+		/* Can't create a file directly inside .index */
+		error = -EBUSY;
+		goto out;
+	}
+
+	if (parent_dir_path.dentry == mi->mi_incomplete_dir) {
+		/* Can't create a file directly inside .incomplete */
+		error = -EBUSY;
+		goto out;
+	}
+
+	/* Look up a dentry in the parent dir. It should be negative. */
+	named_file_dentry = incfs_lookup_dentry(parent_dir_path.dentry,
+					file_name);
+	if (!named_file_dentry) {
+		error = -EFAULT;
+		goto out;
+	}
+	if (IS_ERR(named_file_dentry)) {
+		error = PTR_ERR(named_file_dentry);
+		named_file_dentry = NULL;
+		goto out;
+	}
+	if (d_really_is_positive(named_file_dentry)) {
+		/* File with this path already exists. */
+		error = -EEXIST;
+		goto out;
+	}
+
+	/* Look up a dentry in the incomplete dir. It should be negative. */
+	incomplete_file_dentry = incfs_lookup_dentry(mi->mi_incomplete_dir,
+					file_id_str);
+	if (!incomplete_file_dentry) {
+		error = -EFAULT;
+		goto out;
+	}
+	if (IS_ERR(incomplete_file_dentry)) {
+		error = PTR_ERR(incomplete_file_dentry);
+		incomplete_file_dentry = NULL;
+		goto out;
+	}
+	if (d_really_is_positive(incomplete_file_dentry)) {
+		/* File with this path already exists. */
+		error = -EEXIST;
+		goto out;
+	}
+
+	/* Look up a dentry in the .index dir. It should be negative. */
+	index_file_dentry = incfs_lookup_dentry(mi->mi_index_dir, file_id_str);
+	if (!index_file_dentry) {
+		error = -EFAULT;
+		goto out;
+	}
+	if (IS_ERR(index_file_dentry)) {
+		error = PTR_ERR(index_file_dentry);
+		index_file_dentry = NULL;
+		goto out;
+	}
+	if (d_really_is_positive(index_file_dentry)) {
+		/* File with this ID already exists in index. */
+		error = -EEXIST;
+		goto out;
+	}
+
+	/* Creating a file in the .index dir. */
+	index_dir_inode = d_inode(mi->mi_index_dir);
+	inode_lock_nested(index_dir_inode, I_MUTEX_PARENT);
+	error = vfs_create(index_dir_inode, index_file_dentry, args.mode | 0222,
+			   true);
+	inode_unlock(index_dir_inode);
+
+	if (error)
+		goto out;
+	if (!d_really_is_positive(index_file_dentry)) {
+		error = -EINVAL;
+		goto out;
+	}
+
+	error = chmod(index_file_dentry, args.mode | 0222);
+	if (error) {
+		pr_debug("incfs: chmod err: %d\n", error);
+		goto out;
+	}
+
+	/* Save the file's ID as an xattr for easy fetching in future. */
+	error = vfs_setxattr(index_file_dentry, INCFS_XATTR_ID_NAME,
+		file_id_str, strlen(file_id_str), XATTR_CREATE);
+	if (error) {
+		pr_debug("incfs: vfs_setxattr err:%d\n", error);
+		goto out;
+	}
+
+	/* Save the file's size as an xattr for easy fetching in future. */
+	size_attr_value = cpu_to_le64(args.size);
+	error = vfs_setxattr(index_file_dentry, INCFS_XATTR_SIZE_NAME,
+		(char *)&size_attr_value, sizeof(size_attr_value),
+		XATTR_CREATE);
+	if (error) {
+		pr_debug("incfs: vfs_setxattr err:%d\n", error);
+		goto out;
+	}
+
+	/* Save the file's attribute as an xattr */
+	if (args.file_attr_len && args.file_attr) {
+		if (args.file_attr_len > INCFS_MAX_FILE_ATTR_SIZE) {
+			error = -E2BIG;
+			goto out;
+		}
+
+		attr_value = kmalloc(args.file_attr_len, GFP_NOFS);
+		if (!attr_value) {
+			error = -ENOMEM;
+			goto out;
+		}
+
+		if (copy_from_user(attr_value,
+				u64_to_user_ptr(args.file_attr),
+				args.file_attr_len) > 0) {
+			error = -EFAULT;
+			goto out;
+		}
+
+		error = vfs_setxattr(index_file_dentry,
+				INCFS_XATTR_METADATA_NAME,
+				attr_value, args.file_attr_len,
+				XATTR_CREATE);
+
+		if (error)
+			goto out;
+	}
+
+	/* Initializing a newly created file. */
+	error = init_new_file(mi, index_file_dentry, &args.file_id, args.size,
+			      range(attr_value, args.file_attr_len),
+			      u64_to_user_ptr(args.signature_info),
+			      args.signature_size);
+	if (error)
+		goto out;
+	index_linked = true;
+
+	/* Linking a file with its real name from the requested dir. */
+	error = incfs_link(index_file_dentry, named_file_dentry);
+	if (error)
+		goto out;
+	name_linked = true;
+
+	if (args.size) {
+		/* Linking a file with its incomplete entry */
+		error = incfs_link(index_file_dentry, incomplete_file_dentry);
+		if (error)
+			goto out;
+		incomplete_linked = true;
+	}
+
+	notify_create(file, u64_to_user_ptr(args.directory_path), file_name,
+		      file_id_str, args.size != 0);
+
+out:
+	if (error) {
+		pr_debug("incfs: %s err:%d\n", __func__, error);
+		if (index_linked)
+			incfs_unlink(index_file_dentry);
+		if (name_linked)
+			incfs_unlink(named_file_dentry);
+		if (incomplete_linked)
+			incfs_unlink(incomplete_file_dentry);
+	}
+
+	kfree(file_id_str);
+	kfree(file_name);
+	kfree(attr_value);
+	dput(named_file_dentry);
+	dput(index_file_dentry);
+	dput(incomplete_file_dentry);
+	path_put(&parent_dir_path);
+	if (locked)
+		mutex_unlock(&mi->mi_dir_struct_mutex);
+
+	return error;
+}
+
+static int init_new_mapped_file(struct mount_info *mi, struct dentry *dentry,
+			 incfs_uuid_t *uuid, u64 size, u64 offset)
+{
+	struct path path = {};
+	struct file *new_file;
+	int error = 0;
+	struct backing_file_context *bfc = NULL;
+
+	if (!mi || !dentry || !uuid)
+		return -EFAULT;
+
+	/* Resize newly created file to its true size. */
+	path = (struct path) {
+		.mnt = mi->mi_backing_dir_path.mnt,
+		.dentry = dentry
+	};
+	new_file = dentry_open(&path, O_RDWR | O_NOATIME | O_LARGEFILE,
+			       current_cred());
+
+	if (IS_ERR(new_file)) {
+		error = PTR_ERR(new_file);
+		goto out;
+	}
+
+	bfc = incfs_alloc_bfc(mi, new_file);
+	fput(new_file);
+	if (IS_ERR(bfc)) {
+		error = PTR_ERR(bfc);
+		bfc = NULL;
+		goto out;
+	}
+
+	mutex_lock(&bfc->bc_mutex);
+	error = incfs_write_mapping_fh_to_backing_file(bfc, uuid, size, offset);
+	if (error)
+		goto out;
+
+out:
+	if (bfc) {
+		mutex_unlock(&bfc->bc_mutex);
+		incfs_free_bfc(bfc);
+	}
+
+	if (error)
+		pr_debug("incfs: %s error: %d\n", __func__, error);
+	return error;
+}
+
+static long ioctl_create_mapped_file(struct file *file, void __user *arg)
+{
+	struct mount_info *mi = get_mount_info(file_superblock(file));
+	struct incfs_create_mapped_file_args __user *args_usr_ptr = arg;
+	struct incfs_create_mapped_file_args args = {};
+	char *file_name;
+	int error = 0;
+	struct path parent_dir_path = {};
+	char *source_file_name = NULL;
+	struct dentry *source_file_dentry = NULL;
+	u64 source_file_size;
+	struct dentry *file_dentry = NULL;
+	struct inode *parent_inode;
+	__le64 size_attr_value;
+
+	if (copy_from_user(&args, args_usr_ptr, sizeof(args)) > 0)
+		return -EINVAL;
+
+	file_name = strndup_user(u64_to_user_ptr(args.file_name), PATH_MAX);
+	if (IS_ERR(file_name)) {
+		error = PTR_ERR(file_name);
+		file_name = NULL;
+		goto out;
+	}
+
+	error = validate_name(file_name);
+	if (error)
+		goto out;
+
+	if (args.source_offset % INCFS_DATA_FILE_BLOCK_SIZE) {
+		error = -EINVAL;
+		goto out;
+	}
+
+	/* Validate file mapping is in range */
+	source_file_name = file_id_to_str(args.source_file_id);
+	if (!source_file_name) {
+		pr_warn("Failed to alloc source_file_name\n");
+		error = -ENOMEM;
+		goto out;
+	}
+
+	source_file_dentry = incfs_lookup_dentry(mi->mi_index_dir,
+						       source_file_name);
+	if (!source_file_dentry) {
+		pr_warn("Source file does not exist\n");
+		error = -EINVAL;
+		goto out;
+	}
+	if (IS_ERR(source_file_dentry)) {
+		pr_warn("Error opening source file\n");
+		error = PTR_ERR(source_file_dentry);
+		source_file_dentry = NULL;
+		goto out;
+	}
+	if (!d_really_is_positive(source_file_dentry)) {
+		pr_warn("Source file dentry negative\n");
+		error = -EINVAL;
+		goto out;
+	}
+
+	error = vfs_getxattr(source_file_dentry, INCFS_XATTR_SIZE_NAME,
+			     (char *)&size_attr_value, sizeof(size_attr_value));
+	if (error < 0)
+		goto out;
+
+	if (error != sizeof(size_attr_value)) {
+		pr_warn("Mapped file has no size attr\n");
+		error = -EINVAL;
+		goto out;
+	}
+
+	source_file_size = le64_to_cpu(size_attr_value);
+	if (args.source_offset + args.size > source_file_size) {
+		pr_warn("Mapped file out of range\n");
+		error = -EINVAL;
+		goto out;
+	}
+
+	/* Find a directory to put the file into. */
+	error = dir_relative_path_resolve(mi,
+			u64_to_user_ptr(args.directory_path),
+			&parent_dir_path, NULL);
+	if (error)
+		goto out;
+
+	if (parent_dir_path.dentry == mi->mi_index_dir) {
+		/* Can't create a file directly inside .index */
+		error = -EBUSY;
+		goto out;
+	}
+
+	/* Look up a dentry in the parent dir. It should be negative. */
+	file_dentry = incfs_lookup_dentry(parent_dir_path.dentry,
+					file_name);
+	if (!file_dentry) {
+		error = -EFAULT;
+		goto out;
+	}
+	if (IS_ERR(file_dentry)) {
+		error = PTR_ERR(file_dentry);
+		file_dentry = NULL;
+		goto out;
+	}
+	if (d_really_is_positive(file_dentry)) {
+		error = -EEXIST;
+		goto out;
+	}
+
+	parent_inode = d_inode(parent_dir_path.dentry);
+	inode_lock_nested(parent_inode, I_MUTEX_PARENT);
+	error = vfs_create(parent_inode, file_dentry, args.mode | 0222, true);
+	inode_unlock(parent_inode);
+	if (error)
+		goto out;
+
+	error = chmod(file_dentry, args.mode | 0222);
+	if (error) {
+		pr_debug("incfs: chmod err: %d\n", error);
+		goto delete_file;
+	}
+
+	/* Save the file's size as an xattr for easy fetching in future. */
+	size_attr_value = cpu_to_le64(args.size);
+	error = vfs_setxattr(file_dentry, INCFS_XATTR_SIZE_NAME,
+		(char *)&size_attr_value, sizeof(size_attr_value),
+		XATTR_CREATE);
+	if (error) {
+		pr_debug("incfs: vfs_setxattr err:%d\n", error);
+		goto delete_file;
+	}
+
+	error = init_new_mapped_file(mi, file_dentry, &args.source_file_id,
+			args.size, args.source_offset);
+	if (error)
+		goto delete_file;
+
+	notify_create(file, u64_to_user_ptr(args.directory_path), file_name,
+		      NULL, false);
+
+	goto out;
+
+delete_file:
+	incfs_unlink(file_dentry);
+
+out:
+	dput(file_dentry);
+	dput(source_file_dentry);
+	path_put(&parent_dir_path);
+	kfree(file_name);
+	kfree(source_file_name);
+	return error;
+}
+
+static long ioctl_get_read_timeouts(struct mount_info *mi, void __user *arg)
+{
+	struct incfs_get_read_timeouts_args __user *args_usr_ptr = arg;
+	struct incfs_get_read_timeouts_args args = {};
+	int error = 0;
+	struct incfs_per_uid_read_timeouts *buffer;
+	int size;
+
+	if (copy_from_user(&args, args_usr_ptr, sizeof(args)))
+		return -EINVAL;
+
+	if (args.timeouts_array_size > INCFS_DATA_FILE_BLOCK_SIZE)
+		return -EINVAL;
+
+	buffer = kzalloc(args.timeouts_array_size, GFP_NOFS);
+	if (!buffer)
+		return -ENOMEM;
+
+	spin_lock(&mi->mi_per_uid_read_timeouts_lock);
+	size = mi->mi_per_uid_read_timeouts_size;
+	if (args.timeouts_array_size < size)
+		error = -E2BIG;
+	else if (size)
+		memcpy(buffer, mi->mi_per_uid_read_timeouts, size);
+	spin_unlock(&mi->mi_per_uid_read_timeouts_lock);
+
+	args.timeouts_array_size_out = size;
+	if (!error && size)
+		if (copy_to_user(u64_to_user_ptr(args.timeouts_array), buffer,
+				 size))
+			error = -EFAULT;
+
+	if (!error || error == -E2BIG)
+		if (copy_to_user(args_usr_ptr, &args, sizeof(args)) > 0)
+			error = -EFAULT;
+
+	kfree(buffer);
+	return error;
+}
+
+static long ioctl_set_read_timeouts(struct mount_info *mi, void __user *arg)
+{
+	struct incfs_set_read_timeouts_args __user *args_usr_ptr = arg;
+	struct incfs_set_read_timeouts_args args = {};
+	int error = 0;
+	int size;
+	struct incfs_per_uid_read_timeouts *buffer = NULL, *tmp;
+	int i;
+
+	if (copy_from_user(&args, args_usr_ptr, sizeof(args)))
+		return -EINVAL;
+
+	size = args.timeouts_array_size;
+	if (size) {
+		if (size > INCFS_DATA_FILE_BLOCK_SIZE ||
+		    size % sizeof(*buffer) != 0)
+			return -EINVAL;
+
+		buffer = kzalloc(size, GFP_NOFS);
+		if (!buffer)
+			return -ENOMEM;
+
+		if (copy_from_user(buffer, u64_to_user_ptr(args.timeouts_array),
+				   size)) {
+			error = -EINVAL;
+			goto out;
+		}
+
+		for (i = 0; i < size / sizeof(*buffer); ++i) {
+			struct incfs_per_uid_read_timeouts *t = &buffer[i];
+
+			if (t->min_pending_time_us > t->max_pending_time_us) {
+				error = -EINVAL;
+				goto out;
+			}
+		}
+	}
+
+	spin_lock(&mi->mi_per_uid_read_timeouts_lock);
+	mi->mi_per_uid_read_timeouts_size = size;
+	tmp = mi->mi_per_uid_read_timeouts;
+	mi->mi_per_uid_read_timeouts = buffer;
+	buffer = tmp;
+	spin_unlock(&mi->mi_per_uid_read_timeouts_lock);
+
+out:
+	kfree(buffer);
+	return error;
+}
+
+static long ioctl_get_last_read_error(struct mount_info *mi, void __user *arg)
+{
+	struct incfs_get_last_read_error_args __user *args_usr_ptr = arg;
+	struct incfs_get_last_read_error_args args = {};
+	int error;
+
+	error = mutex_lock_interruptible(&mi->mi_le_mutex);
+	if (error)
+		return error;
+
+	args.file_id_out = mi->mi_le_file_id;
+	args.time_us_out = mi->mi_le_time_us;
+	args.page_out = mi->mi_le_page;
+	args.errno_out = mi->mi_le_errno;
+	args.uid_out = mi->mi_le_uid;
+
+	mutex_unlock(&mi->mi_le_mutex);
+	if (copy_to_user(args_usr_ptr, &args, sizeof(args)) > 0)
+		error = -EFAULT;
+
+	return error;
+}
+
+static long pending_reads_dispatch_ioctl(struct file *f, unsigned int req,
+					unsigned long arg)
+{
+	struct mount_info *mi = get_mount_info(file_superblock(f));
+
+	switch (req) {
+	case INCFS_IOC_CREATE_FILE:
+		return ioctl_create_file(f, (void __user *)arg);
+	case INCFS_IOC_PERMIT_FILL:
+		return ioctl_permit_fill(f, (void __user *)arg);
+	case INCFS_IOC_CREATE_MAPPED_FILE:
+		return ioctl_create_mapped_file(f, (void __user *)arg);
+	case INCFS_IOC_GET_READ_TIMEOUTS:
+		return ioctl_get_read_timeouts(mi, (void __user *)arg);
+	case INCFS_IOC_SET_READ_TIMEOUTS:
+		return ioctl_set_read_timeouts(mi, (void __user *)arg);
+	case INCFS_IOC_GET_LAST_READ_ERROR:
+		return ioctl_get_last_read_error(mi, (void __user *)arg);
+	default:
+		return -EINVAL;
+	}
+}
+
+static const struct file_operations incfs_pending_reads_file_ops = {
+	.read = pending_reads_read,
+	.poll = pending_reads_poll,
+	.open = pending_reads_open,
+	.release = pending_reads_release,
+	.llseek = noop_llseek,
+	.unlocked_ioctl = pending_reads_dispatch_ioctl,
+	.compat_ioctl = pending_reads_dispatch_ioctl
+};
+
+/*******************************************************************************
+ * .log pseudo file definition
+ ******************************************************************************/
+#define INCFS_LOG_INODE 3
+static const char log_file_name[] = INCFS_LOG_FILENAME;
+
+/* State of an open .log file, unique for each file descriptor. */
+struct log_file_state {
+	struct read_log_state state;
+};
+
+static ssize_t log_read(struct file *f, char __user *buf, size_t len,
+			loff_t *ppos)
+{
+	struct log_file_state *log_state = f->private_data;
+	struct mount_info *mi = get_mount_info(file_superblock(f));
+	int total_reads_collected = 0;
+	int rl_size;
+	ssize_t result = 0;
+	bool report_uid;
+	unsigned long page = 0;
+	struct incfs_pending_read_info *reads_buf = NULL;
+	struct incfs_pending_read_info2 *reads_buf2 = NULL;
+	size_t record_size;
+	ssize_t reads_to_collect;
+	ssize_t reads_per_page;
+
+	if (!mi)
+		return -EFAULT;
+
+	report_uid = mi->mi_options.report_uid;
+	record_size = report_uid ? sizeof(*reads_buf2) : sizeof(*reads_buf);
+	reads_to_collect = len / record_size;
+	reads_per_page = PAGE_SIZE / record_size;
+
+	rl_size = READ_ONCE(mi->mi_log.rl_size);
+	if (rl_size == 0)
+		return 0;
+
+	page = __get_free_page(GFP_NOFS);
+	if (!page)
+		return -ENOMEM;
+
+	if (report_uid)
+		reads_buf2 = (struct incfs_pending_read_info2 *)page;
+	else
+		reads_buf = (struct incfs_pending_read_info *)page;
+
+	reads_to_collect = min_t(ssize_t, rl_size, reads_to_collect);
+	while (reads_to_collect > 0) {
+		struct read_log_state next_state;
+		int reads_collected;
+
+		memcpy(&next_state, &log_state->state, sizeof(next_state));
+		reads_collected = incfs_collect_logged_reads(
+			mi, &next_state, reads_buf, reads_buf2,
+			min_t(ssize_t, reads_to_collect, reads_per_page));
+		if (reads_collected <= 0) {
+			result = total_reads_collected ?
+				       total_reads_collected * record_size :
+				       reads_collected;
+			goto out;
+		}
+		if (copy_to_user(buf, (void *)page,
+				 reads_collected * record_size)) {
+			result = total_reads_collected ?
+				       total_reads_collected * record_size :
+				       -EFAULT;
+			goto out;
+		}
+
+		memcpy(&log_state->state, &next_state, sizeof(next_state));
+		total_reads_collected += reads_collected;
+		buf += reads_collected * record_size;
+		reads_to_collect -= reads_collected;
+	}
+
+	result = total_reads_collected * record_size;
+	*ppos = 0;
+out:
+	free_page(page);
+	return result;
+}
+
+static __poll_t log_poll(struct file *file, poll_table *wait)
+{
+	struct log_file_state *log_state = file->private_data;
+	struct mount_info *mi = get_mount_info(file_superblock(file));
+	int count;
+	__poll_t ret = 0;
+
+	poll_wait(file, &mi->mi_log.ml_notif_wq, wait);
+	count = incfs_get_uncollected_logs_count(mi, &log_state->state);
+	if (count >= mi->mi_options.read_log_wakeup_count)
+		ret = EPOLLIN | EPOLLRDNORM;
+
+	return ret;
+}
+
+static int log_open(struct inode *inode, struct file *file)
+{
+	struct log_file_state *log_state = NULL;
+	struct mount_info *mi = get_mount_info(file_superblock(file));
+
+	log_state = kzalloc(sizeof(*log_state), GFP_NOFS);
+	if (!log_state)
+		return -ENOMEM;
+
+	log_state->state = incfs_get_log_state(mi);
+	file->private_data = log_state;
+	return 0;
+}
+
+static int log_release(struct inode *inode, struct file *file)
+{
+	kfree(file->private_data);
+	return 0;
+}
+
+static const struct file_operations incfs_log_file_ops = {
+	.read = log_read,
+	.poll = log_poll,
+	.open = log_open,
+	.release = log_release,
+	.llseek = noop_llseek,
+};
+
+/*******************************************************************************
+ * .blocks_written pseudo file definition
+ ******************************************************************************/
+#define INCFS_BLOCKS_WRITTEN_INODE 4
+static const char blocks_written_file_name[] = INCFS_BLOCKS_WRITTEN_FILENAME;
+
+/* State of an open .blocks_written file, unique for each file descriptor. */
+struct blocks_written_file_state {
+	unsigned long blocks_written;
+};
+
+static ssize_t blocks_written_read(struct file *f, char __user *buf, size_t len,
+			loff_t *ppos)
+{
+	struct mount_info *mi = get_mount_info(file_superblock(f));
+	struct blocks_written_file_state *state = f->private_data;
+	unsigned long blocks_written;
+	char string[21];
+	int result = 0;
+
+	if (!mi)
+		return -EFAULT;
+
+	blocks_written = atomic_read(&mi->mi_blocks_written);
+	if (state->blocks_written == blocks_written)
+		return 0;
+
+	result = snprintf(string, sizeof(string), "%lu", blocks_written);
+	if (result > len)
+		result = len;
+	if (copy_to_user(buf, string, result))
+		return -EFAULT;
+
+	state->blocks_written = blocks_written;
+	return result;
+}
+
+static __poll_t blocks_written_poll(struct file *f, poll_table *wait)
+{
+	struct mount_info *mi = get_mount_info(file_superblock(f));
+	struct blocks_written_file_state *state = f->private_data;
+	unsigned long blocks_written;
+
+	if (!mi)
+		return 0;
+
+	poll_wait(f, &mi->mi_blocks_written_notif_wq, wait);
+	blocks_written = atomic_read(&mi->mi_blocks_written);
+	if (state->blocks_written == blocks_written)
+		return 0;
+
+	return EPOLLIN | EPOLLRDNORM;
+}
+
+static int blocks_written_open(struct inode *inode, struct file *file)
+{
+	struct blocks_written_file_state *state =
+		kzalloc(sizeof(*state), GFP_NOFS);
+
+	if (!state)
+		return -ENOMEM;
+
+	state->blocks_written = -1;
+	file->private_data = state;
+	return 0;
+}
+
+static int blocks_written_release(struct inode *inode, struct file *file)
+{
+	kfree(file->private_data);
+	return 0;
+}
+
+static const struct file_operations incfs_blocks_written_file_ops = {
+	.read = blocks_written_read,
+	.poll = blocks_written_poll,
+	.open = blocks_written_open,
+	.release = blocks_written_release,
+	.llseek = noop_llseek,
+};
+
+/*******************************************************************************
+ * Generic inode lookup functionality
+ ******************************************************************************/
+
+const struct mem_range incfs_pseudo_file_names[] = {
+	{ .data = (u8 *)pending_reads_file_name,
+	  .len = ARRAY_SIZE(pending_reads_file_name) - 1 },
+	{ .data = (u8 *)log_file_name, .len = ARRAY_SIZE(log_file_name) - 1 },
+	{ .data = (u8 *)blocks_written_file_name,
+	  .len = ARRAY_SIZE(blocks_written_file_name) - 1 }
+};
+
+const unsigned long incfs_pseudo_file_inodes[] = { INCFS_PENDING_READS_INODE,
+						   INCFS_LOG_INODE,
+						   INCFS_BLOCKS_WRITTEN_INODE };
+
+static const struct file_operations *const pseudo_file_operations[] = {
+	&incfs_pending_reads_file_ops, &incfs_log_file_ops,
+	&incfs_blocks_written_file_ops
+};
+
+static bool is_pseudo_filename(struct mem_range name)
+{
+	int i = 0;
+
+	for (; i < ARRAY_SIZE(incfs_pseudo_file_names); ++i)
+		if (incfs_equal_ranges(incfs_pseudo_file_names[i], name))
+			return true;
+	return false;
+}
+
+static bool get_pseudo_inode(int ino, struct inode *inode)
+{
+	int i = 0;
+
+	for (; i < ARRAY_SIZE(incfs_pseudo_file_inodes); ++i)
+		if (ino == incfs_pseudo_file_inodes[i])
+			break;
+	if (i == ARRAY_SIZE(incfs_pseudo_file_inodes))
+		return false;
+
+	inode->i_ctime = (struct timespec64){};
+	inode->i_mtime = inode->i_ctime;
+	inode->i_atime = inode->i_ctime;
+	inode->i_size = 0;
+	inode->i_ino = ino;
+	inode->i_private = NULL;
+	inode_init_owner(inode, NULL, S_IFREG | READ_WRITE_FILE_MODE);
+	inode->i_op = &incfs_file_inode_ops;
+	inode->i_fop = pseudo_file_operations[i];
+	return true;
+}
+
+struct inode_search {
+	unsigned long ino;
+};
+
+static int inode_test(struct inode *inode, void *opaque)
+{
+	struct inode_search *search = opaque;
+
+	return inode->i_ino == search->ino;
+}
+
+static int inode_set(struct inode *inode, void *opaque)
+{
+	struct inode_search *search = opaque;
+
+	if (get_pseudo_inode(search->ino, inode))
+		return 0;
+
+	/* Unknown inode requested. */
+	return -EINVAL;
+}
+
+static struct inode *fetch_inode(struct super_block *sb, unsigned long ino)
+{
+	struct inode_search search = {
+		.ino = ino
+	};
+	struct inode *inode = iget5_locked(sb, search.ino, inode_test,
+				inode_set, &search);
+
+	if (!inode)
+		return ERR_PTR(-ENOMEM);
+
+	if (inode->i_state & I_NEW)
+		unlock_new_inode(inode);
+
+	return inode;
+}
+
+int dir_lookup_pseudo_files(struct super_block *sb, struct dentry *dentry)
+{
+	struct mem_range name_range =
+			range((u8 *)dentry->d_name.name, dentry->d_name.len);
+	unsigned long ino;
+	struct inode *inode;
+	int i = 0;
+
+	for (; i < ARRAY_SIZE(incfs_pseudo_file_names); ++i)
+		if (incfs_equal_ranges(incfs_pseudo_file_names[i], name_range))
+			break;
+	if (i == ARRAY_SIZE(incfs_pseudo_file_names))
+		return -ENOENT;
+
+	ino = incfs_pseudo_file_inodes[i];
+
+	inode = fetch_inode(sb, ino);
+	if (IS_ERR(inode))
+		return PTR_ERR(inode);
+
+	d_add(dentry, inode);
+	return 0;
+}
+
+int emit_pseudo_files(struct dir_context *ctx)
+{
+	loff_t i = ctx->pos;
+
+	for (; i < ARRAY_SIZE(incfs_pseudo_file_names); ++i) {
+		if (!dir_emit(ctx, incfs_pseudo_file_names[i].data,
+			      incfs_pseudo_file_names[i].len,
+			      incfs_pseudo_file_inodes[i], DT_REG))
+			return -EINVAL;
+
+		ctx->pos++;
+	}
+	return 0;
+}