[Feature]add MT2731_MP2_MR2_SVN388 baseline version

Change-Id: Ief04314834b31e27effab435d3ca8ba33b499059
diff --git a/src/kernel/linux/v4.14/fs/ext4/file.c b/src/kernel/linux/v4.14/fs/ext4/file.c
new file mode 100644
index 0000000..acec134
--- /dev/null
+++ b/src/kernel/linux/v4.14/fs/ext4/file.c
@@ -0,0 +1,752 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  linux/fs/ext4/file.c
+ *
+ * Copyright (C) 1992, 1993, 1994, 1995
+ * Remy Card (card@masi.ibp.fr)
+ * Laboratoire MASI - Institut Blaise Pascal
+ * Universite Pierre et Marie Curie (Paris VI)
+ *
+ *  from
+ *
+ *  linux/fs/minix/file.c
+ *
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ *
+ *  ext4 fs regular file handling primitives
+ *
+ *  64-bit file support on 64-bit platforms by Jakub Jelinek
+ *	(jj@sunsite.ms.mff.cuni.cz)
+ */
+
+#include <linux/time.h>
+#include <linux/fs.h>
+#include <linux/mount.h>
+#include <linux/path.h>
+#include <linux/dax.h>
+#include <linux/quotaops.h>
+#include <linux/pagevec.h>
+#include <linux/uio.h>
+#include "ext4.h"
+#include "ext4_jbd2.h"
+#include "xattr.h"
+#include "acl.h"
+
+#ifdef CONFIG_FS_DAX
+static ssize_t ext4_dax_read_iter(struct kiocb *iocb, struct iov_iter *to)
+{
+	struct inode *inode = file_inode(iocb->ki_filp);
+	ssize_t ret;
+
+	if (iocb->ki_flags & IOCB_NOWAIT) {
+		if (!inode_trylock_shared(inode))
+			return -EAGAIN;
+	} else {
+		inode_lock_shared(inode);
+	}
+	/*
+	 * Recheck under inode lock - at this point we are sure it cannot
+	 * change anymore
+	 */
+	if (!IS_DAX(inode)) {
+		inode_unlock_shared(inode);
+		/* Fallback to buffered IO in case we cannot support DAX */
+		return generic_file_read_iter(iocb, to);
+	}
+	ret = dax_iomap_rw(iocb, to, &ext4_iomap_ops);
+	inode_unlock_shared(inode);
+
+	file_accessed(iocb->ki_filp);
+	return ret;
+}
+#endif
+
+static ssize_t ext4_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
+{
+	if (unlikely(ext4_forced_shutdown(EXT4_SB(file_inode(iocb->ki_filp)->i_sb))))
+		return -EIO;
+
+	if (!iov_iter_count(to))
+		return 0; /* skip atime */
+
+#ifdef CONFIG_FS_DAX
+	if (IS_DAX(file_inode(iocb->ki_filp)))
+		return ext4_dax_read_iter(iocb, to);
+#endif
+	return generic_file_read_iter(iocb, to);
+}
+
+/*
+ * Called when an inode is released. Note that this is different
+ * from ext4_file_open: open gets called at every open, but release
+ * gets called only when /all/ the files are closed.
+ */
+static int ext4_release_file(struct inode *inode, struct file *filp)
+{
+	if (ext4_test_inode_state(inode, EXT4_STATE_DA_ALLOC_CLOSE)) {
+		ext4_alloc_da_blocks(inode);
+		ext4_clear_inode_state(inode, EXT4_STATE_DA_ALLOC_CLOSE);
+	}
+	/* if we are the last writer on the inode, drop the block reservation */
+	if ((filp->f_mode & FMODE_WRITE) &&
+			(atomic_read(&inode->i_writecount) == 1) &&
+		        !EXT4_I(inode)->i_reserved_data_blocks)
+	{
+		down_write(&EXT4_I(inode)->i_data_sem);
+		ext4_discard_preallocations(inode);
+		up_write(&EXT4_I(inode)->i_data_sem);
+	}
+	if (is_dx(inode) && filp->private_data)
+		ext4_htree_free_dir_info(filp->private_data);
+
+	return 0;
+}
+
+static void ext4_unwritten_wait(struct inode *inode)
+{
+	wait_queue_head_t *wq = ext4_ioend_wq(inode);
+
+	wait_event(*wq, (atomic_read(&EXT4_I(inode)->i_unwritten) == 0));
+}
+
+/*
+ * This tests whether the IO in question is block-aligned or not.
+ * Ext4 utilizes unwritten extents when hole-filling during direct IO, and they
+ * are converted to written only after the IO is complete.  Until they are
+ * mapped, these blocks appear as holes, so dio_zero_block() will assume that
+ * it needs to zero out portions of the start and/or end block.  If 2 AIO
+ * threads are at work on the same unwritten block, they must be synchronized
+ * or one thread will zero the other's data, causing corruption.
+ */
+static int
+ext4_unaligned_aio(struct inode *inode, struct iov_iter *from, loff_t pos)
+{
+	struct super_block *sb = inode->i_sb;
+	int blockmask = sb->s_blocksize - 1;
+
+	if (pos >= ALIGN(i_size_read(inode), sb->s_blocksize))
+		return 0;
+
+	if ((pos | iov_iter_alignment(from)) & blockmask)
+		return 1;
+
+	return 0;
+}
+
+/* Is IO overwriting allocated and initialized blocks? */
+static bool ext4_overwrite_io(struct inode *inode, loff_t pos, loff_t len)
+{
+	struct ext4_map_blocks map;
+	unsigned int blkbits = inode->i_blkbits;
+	int err, blklen;
+
+	if (pos + len > i_size_read(inode))
+		return false;
+
+	map.m_lblk = pos >> blkbits;
+	map.m_len = EXT4_MAX_BLOCKS(len, pos, blkbits);
+	blklen = map.m_len;
+
+	err = ext4_map_blocks(NULL, inode, &map, 0);
+	/*
+	 * 'err==len' means that all of the blocks have been preallocated,
+	 * regardless of whether they have been initialized or not. To exclude
+	 * unwritten extents, we need to check m_flags.
+	 */
+	return err == blklen && (map.m_flags & EXT4_MAP_MAPPED);
+}
+
+static ssize_t ext4_write_checks(struct kiocb *iocb, struct iov_iter *from)
+{
+	struct inode *inode = file_inode(iocb->ki_filp);
+	ssize_t ret;
+
+	ret = generic_write_checks(iocb, from);
+	if (ret <= 0)
+		return ret;
+
+	if (unlikely(IS_IMMUTABLE(inode)))
+		return -EPERM;
+
+	/*
+	 * If we have encountered a bitmap-format file, the size limit
+	 * is smaller than s_maxbytes, which is for extent-mapped files.
+	 */
+	if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) {
+		struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+
+		if (iocb->ki_pos >= sbi->s_bitmap_maxbytes)
+			return -EFBIG;
+		iov_iter_truncate(from, sbi->s_bitmap_maxbytes - iocb->ki_pos);
+	}
+	return iov_iter_count(from);
+}
+
+#ifdef CONFIG_FS_DAX
+static ssize_t
+ext4_dax_write_iter(struct kiocb *iocb, struct iov_iter *from)
+{
+	struct inode *inode = file_inode(iocb->ki_filp);
+	ssize_t ret;
+
+	if (iocb->ki_flags & IOCB_NOWAIT) {
+		if (!inode_trylock(inode))
+			return -EAGAIN;
+	} else {
+		inode_lock(inode);
+	}
+	ret = ext4_write_checks(iocb, from);
+	if (ret <= 0)
+		goto out;
+	ret = file_remove_privs(iocb->ki_filp);
+	if (ret)
+		goto out;
+	ret = file_update_time(iocb->ki_filp);
+	if (ret)
+		goto out;
+
+	ret = dax_iomap_rw(iocb, from, &ext4_iomap_ops);
+out:
+	inode_unlock(inode);
+	if (ret > 0)
+		ret = generic_write_sync(iocb, ret);
+	return ret;
+}
+#endif
+
+static ssize_t
+ext4_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
+{
+	struct inode *inode = file_inode(iocb->ki_filp);
+	int o_direct = iocb->ki_flags & IOCB_DIRECT;
+	int unaligned_aio = 0;
+	int overwrite = 0;
+	ssize_t ret;
+
+	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
+		return -EIO;
+
+#ifdef CONFIG_FS_DAX
+	if (IS_DAX(inode))
+		return ext4_dax_write_iter(iocb, from);
+#endif
+	if (!o_direct && (iocb->ki_flags & IOCB_NOWAIT))
+		return -EOPNOTSUPP;
+
+	if (!inode_trylock(inode)) {
+		if (iocb->ki_flags & IOCB_NOWAIT)
+			return -EAGAIN;
+		inode_lock(inode);
+	}
+
+	ret = ext4_write_checks(iocb, from);
+	if (ret <= 0)
+		goto out;
+
+	/*
+	 * Unaligned direct AIO must be serialized among each other as zeroing
+	 * of partial blocks of two competing unaligned AIOs can result in data
+	 * corruption.
+	 */
+	if (o_direct && ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS) &&
+	    !is_sync_kiocb(iocb) &&
+	    ext4_unaligned_aio(inode, from, iocb->ki_pos)) {
+		unaligned_aio = 1;
+		ext4_unwritten_wait(inode);
+	}
+
+	iocb->private = &overwrite;
+	/* Check whether we do a DIO overwrite or not */
+	if (o_direct && !unaligned_aio) {
+		if (ext4_overwrite_io(inode, iocb->ki_pos, iov_iter_count(from))) {
+			if (ext4_should_dioread_nolock(inode))
+				overwrite = 1;
+		} else if (iocb->ki_flags & IOCB_NOWAIT) {
+			ret = -EAGAIN;
+			goto out;
+		}
+	}
+
+	ret = __generic_file_write_iter(iocb, from);
+	/*
+	 * Unaligned direct AIO must be the only IO in flight. Otherwise
+	 * overlapping aligned IO after unaligned might result in data
+	 * corruption.
+	 */
+	if (ret == -EIOCBQUEUED && unaligned_aio)
+		ext4_unwritten_wait(inode);
+	inode_unlock(inode);
+
+	if (ret > 0)
+		ret = generic_write_sync(iocb, ret);
+
+	return ret;
+
+out:
+	inode_unlock(inode);
+	return ret;
+}
+
+#ifdef CONFIG_FS_DAX
+static int ext4_dax_huge_fault(struct vm_fault *vmf,
+		enum page_entry_size pe_size)
+{
+	int result;
+	handle_t *handle = NULL;
+	struct inode *inode = file_inode(vmf->vma->vm_file);
+	struct super_block *sb = inode->i_sb;
+
+	/*
+	 * We have to distinguish real writes from writes which will result in a
+	 * COW page; COW writes should *not* poke the journal (the file will not
+	 * be changed). Doing so would cause unintended failures when mounted
+	 * read-only.
+	 *
+	 * We check for VM_SHARED rather than vmf->cow_page since the latter is
+	 * unset for pe_size != PE_SIZE_PTE (i.e. only in do_cow_fault); for
+	 * other sizes, dax_iomap_fault will handle splitting / fallback so that
+	 * we eventually come back with a COW page.
+	 */
+	bool write = (vmf->flags & FAULT_FLAG_WRITE) &&
+		(vmf->vma->vm_flags & VM_SHARED);
+
+	if (write) {
+		sb_start_pagefault(sb);
+		file_update_time(vmf->vma->vm_file);
+		down_read(&EXT4_I(inode)->i_mmap_sem);
+		handle = ext4_journal_start_sb(sb, EXT4_HT_WRITE_PAGE,
+					       EXT4_DATA_TRANS_BLOCKS(sb));
+	} else {
+		down_read(&EXT4_I(inode)->i_mmap_sem);
+	}
+	if (!IS_ERR(handle))
+		result = dax_iomap_fault(vmf, pe_size, &ext4_iomap_ops);
+	else
+		result = VM_FAULT_SIGBUS;
+	if (write) {
+		if (!IS_ERR(handle))
+			ext4_journal_stop(handle);
+		up_read(&EXT4_I(inode)->i_mmap_sem);
+		sb_end_pagefault(sb);
+	} else {
+		up_read(&EXT4_I(inode)->i_mmap_sem);
+	}
+
+	return result;
+}
+
+static int ext4_dax_fault(struct vm_fault *vmf)
+{
+	return ext4_dax_huge_fault(vmf, PE_SIZE_PTE);
+}
+
+static const struct vm_operations_struct ext4_dax_vm_ops = {
+	.fault		= ext4_dax_fault,
+	.huge_fault	= ext4_dax_huge_fault,
+	.page_mkwrite	= ext4_dax_fault,
+	.pfn_mkwrite	= ext4_dax_fault,
+};
+#else
+#define ext4_dax_vm_ops	ext4_file_vm_ops
+#endif
+
+static const struct vm_operations_struct ext4_file_vm_ops = {
+	.fault		= ext4_filemap_fault,
+	.map_pages	= filemap_map_pages,
+	.page_mkwrite   = ext4_page_mkwrite,
+};
+
+static int ext4_file_mmap(struct file *file, struct vm_area_struct *vma)
+{
+	struct inode *inode = file->f_mapping->host;
+
+	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
+		return -EIO;
+
+	file_accessed(file);
+	if (IS_DAX(file_inode(file))) {
+		vma->vm_ops = &ext4_dax_vm_ops;
+		vma->vm_flags |= VM_MIXEDMAP | VM_HUGEPAGE;
+	} else {
+		vma->vm_ops = &ext4_file_vm_ops;
+	}
+	return 0;
+}
+
+static int ext4_file_open(struct inode * inode, struct file * filp)
+{
+	struct super_block *sb = inode->i_sb;
+	struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+	struct vfsmount *mnt = filp->f_path.mnt;
+	struct dentry *dir;
+	struct path path;
+	char buf[64], *cp;
+	int ret;
+
+	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
+		return -EIO;
+
+	if (unlikely(!(sbi->s_mount_flags & EXT4_MF_MNTDIR_SAMPLED) &&
+		     !sb_rdonly(sb))) {
+		sbi->s_mount_flags |= EXT4_MF_MNTDIR_SAMPLED;
+		/*
+		 * Sample where the filesystem has been mounted and
+		 * store it in the superblock for sysadmin convenience
+		 * when trying to sort through large numbers of block
+		 * devices or filesystem images.
+		 */
+		memset(buf, 0, sizeof(buf));
+		path.mnt = mnt;
+		path.dentry = mnt->mnt_root;
+		cp = d_path(&path, buf, sizeof(buf));
+		if (!IS_ERR(cp)) {
+			handle_t *handle;
+			int err;
+
+			handle = ext4_journal_start_sb(sb, EXT4_HT_MISC, 1);
+			if (IS_ERR(handle))
+				return PTR_ERR(handle);
+			BUFFER_TRACE(sbi->s_sbh, "get_write_access");
+			err = ext4_journal_get_write_access(handle, sbi->s_sbh);
+			if (err) {
+				ext4_journal_stop(handle);
+				return err;
+			}
+			strlcpy(sbi->s_es->s_last_mounted, cp,
+				sizeof(sbi->s_es->s_last_mounted));
+			ext4_handle_dirty_super(handle, sb);
+			ext4_journal_stop(handle);
+		}
+	}
+	if (ext4_encrypted_inode(inode)) {
+		ret = fscrypt_get_encryption_info(inode);
+		if (ret)
+			return -EACCES;
+		if (!fscrypt_has_encryption_key(inode))
+			return -ENOKEY;
+	}
+
+	dir = dget_parent(file_dentry(filp));
+	if (ext4_encrypted_inode(d_inode(dir)) &&
+			!fscrypt_has_permitted_context(d_inode(dir), inode)) {
+		ext4_warning(inode->i_sb,
+			     "Inconsistent encryption contexts: %lu/%lu",
+			     (unsigned long) d_inode(dir)->i_ino,
+			     (unsigned long) inode->i_ino);
+		dput(dir);
+		return -EPERM;
+	}
+	dput(dir);
+	/*
+	 * Set up the jbd2_inode if we are opening the inode for
+	 * writing and the journal is present
+	 */
+	if (filp->f_mode & FMODE_WRITE) {
+		ret = ext4_inode_attach_jinode(inode);
+		if (ret < 0)
+			return ret;
+	}
+
+	filp->f_mode |= FMODE_NOWAIT;
+	return dquot_file_open(inode, filp);
+}
+
+/*
+ * Here we use ext4_map_blocks() to get a block mapping for a extent-based
+ * file rather than ext4_ext_walk_space() because we can introduce
+ * SEEK_DATA/SEEK_HOLE for block-mapped and extent-mapped file at the same
+ * function.  When extent status tree has been fully implemented, it will
+ * track all extent status for a file and we can directly use it to
+ * retrieve the offset for SEEK_DATA/SEEK_HOLE.
+ */
+
+/*
+ * When we retrieve the offset for SEEK_DATA/SEEK_HOLE, we would need to
+ * lookup page cache to check whether or not there has some data between
+ * [startoff, endoff] because, if this range contains an unwritten extent,
+ * we determine this extent as a data or a hole according to whether the
+ * page cache has data or not.
+ */
+static int ext4_find_unwritten_pgoff(struct inode *inode,
+				     int whence,
+				     ext4_lblk_t end_blk,
+				     loff_t *offset)
+{
+	struct pagevec pvec;
+	unsigned int blkbits;
+	pgoff_t index;
+	pgoff_t end;
+	loff_t endoff;
+	loff_t startoff;
+	loff_t lastoff;
+	int found = 0;
+
+	blkbits = inode->i_sb->s_blocksize_bits;
+	startoff = *offset;
+	lastoff = startoff;
+	endoff = (loff_t)end_blk << blkbits;
+
+	index = startoff >> PAGE_SHIFT;
+	end = (endoff - 1) >> PAGE_SHIFT;
+
+	pagevec_init(&pvec, 0);
+	do {
+		int i;
+		unsigned long nr_pages;
+
+		nr_pages = pagevec_lookup_range(&pvec, inode->i_mapping,
+					&index, end);
+		if (nr_pages == 0)
+			break;
+
+		for (i = 0; i < nr_pages; i++) {
+			struct page *page = pvec.pages[i];
+			struct buffer_head *bh, *head;
+
+			/*
+			 * If current offset is smaller than the page offset,
+			 * there is a hole at this offset.
+			 */
+			if (whence == SEEK_HOLE && lastoff < endoff &&
+			    lastoff < page_offset(pvec.pages[i])) {
+				found = 1;
+				*offset = lastoff;
+				goto out;
+			}
+
+			lock_page(page);
+
+			if (unlikely(page->mapping != inode->i_mapping)) {
+				unlock_page(page);
+				continue;
+			}
+
+			if (!page_has_buffers(page)) {
+				unlock_page(page);
+				continue;
+			}
+
+			if (page_has_buffers(page)) {
+				lastoff = page_offset(page);
+				bh = head = page_buffers(page);
+				do {
+					if (lastoff + bh->b_size <= startoff)
+						goto next;
+					if (buffer_uptodate(bh) ||
+					    buffer_unwritten(bh)) {
+						if (whence == SEEK_DATA)
+							found = 1;
+					} else {
+						if (whence == SEEK_HOLE)
+							found = 1;
+					}
+					if (found) {
+						*offset = max_t(loff_t,
+							startoff, lastoff);
+						unlock_page(page);
+						goto out;
+					}
+next:
+					lastoff += bh->b_size;
+					bh = bh->b_this_page;
+				} while (bh != head);
+			}
+
+			lastoff = page_offset(page) + PAGE_SIZE;
+			unlock_page(page);
+		}
+
+		pagevec_release(&pvec);
+	} while (index <= end);
+
+	/* There are no pages upto endoff - that would be a hole in there. */
+	if (whence == SEEK_HOLE && lastoff < endoff) {
+		found = 1;
+		*offset = lastoff;
+	}
+out:
+	pagevec_release(&pvec);
+	return found;
+}
+
+/*
+ * ext4_seek_data() retrieves the offset for SEEK_DATA.
+ */
+static loff_t ext4_seek_data(struct file *file, loff_t offset, loff_t maxsize)
+{
+	struct inode *inode = file->f_mapping->host;
+	struct extent_status es;
+	ext4_lblk_t start, last, end;
+	loff_t dataoff, isize;
+	int blkbits;
+	int ret;
+
+	inode_lock(inode);
+
+	isize = i_size_read(inode);
+	if (offset < 0 || offset >= isize) {
+		inode_unlock(inode);
+		return -ENXIO;
+	}
+
+	blkbits = inode->i_sb->s_blocksize_bits;
+	start = offset >> blkbits;
+	last = start;
+	end = isize >> blkbits;
+	dataoff = offset;
+
+	do {
+		ret = ext4_get_next_extent(inode, last, end - last + 1, &es);
+		if (ret <= 0) {
+			/* No extent found -> no data */
+			if (ret == 0)
+				ret = -ENXIO;
+			inode_unlock(inode);
+			return ret;
+		}
+
+		last = es.es_lblk;
+		if (last != start)
+			dataoff = (loff_t)last << blkbits;
+		if (!ext4_es_is_unwritten(&es))
+			break;
+
+		/*
+		 * If there is a unwritten extent at this offset,
+		 * it will be as a data or a hole according to page
+		 * cache that has data or not.
+		 */
+		if (ext4_find_unwritten_pgoff(inode, SEEK_DATA,
+					      es.es_lblk + es.es_len, &dataoff))
+			break;
+		last += es.es_len;
+		dataoff = (loff_t)last << blkbits;
+		cond_resched();
+	} while (last <= end);
+
+	inode_unlock(inode);
+
+	if (dataoff > isize)
+		return -ENXIO;
+
+	return vfs_setpos(file, dataoff, maxsize);
+}
+
+/*
+ * ext4_seek_hole() retrieves the offset for SEEK_HOLE.
+ */
+static loff_t ext4_seek_hole(struct file *file, loff_t offset, loff_t maxsize)
+{
+	struct inode *inode = file->f_mapping->host;
+	struct extent_status es;
+	ext4_lblk_t start, last, end;
+	loff_t holeoff, isize;
+	int blkbits;
+	int ret;
+
+	inode_lock(inode);
+
+	isize = i_size_read(inode);
+	if (offset < 0 || offset >= isize) {
+		inode_unlock(inode);
+		return -ENXIO;
+	}
+
+	blkbits = inode->i_sb->s_blocksize_bits;
+	start = offset >> blkbits;
+	last = start;
+	end = isize >> blkbits;
+	holeoff = offset;
+
+	do {
+		ret = ext4_get_next_extent(inode, last, end - last + 1, &es);
+		if (ret < 0) {
+			inode_unlock(inode);
+			return ret;
+		}
+		/* Found a hole? */
+		if (ret == 0 || es.es_lblk > last) {
+			if (last != start)
+				holeoff = (loff_t)last << blkbits;
+			break;
+		}
+		/*
+		 * If there is a unwritten extent at this offset,
+		 * it will be as a data or a hole according to page
+		 * cache that has data or not.
+		 */
+		if (ext4_es_is_unwritten(&es) &&
+		    ext4_find_unwritten_pgoff(inode, SEEK_HOLE,
+					      last + es.es_len, &holeoff))
+			break;
+
+		last += es.es_len;
+		holeoff = (loff_t)last << blkbits;
+		cond_resched();
+	} while (last <= end);
+
+	inode_unlock(inode);
+
+	if (holeoff > isize)
+		holeoff = isize;
+
+	return vfs_setpos(file, holeoff, maxsize);
+}
+
+/*
+ * ext4_llseek() handles both block-mapped and extent-mapped maxbytes values
+ * by calling generic_file_llseek_size() with the appropriate maxbytes
+ * value for each.
+ */
+loff_t ext4_llseek(struct file *file, loff_t offset, int whence)
+{
+	struct inode *inode = file->f_mapping->host;
+	loff_t maxbytes;
+
+	if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
+		maxbytes = EXT4_SB(inode->i_sb)->s_bitmap_maxbytes;
+	else
+		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:
+		return ext4_seek_data(file, offset, maxbytes);
+	case SEEK_HOLE:
+		return ext4_seek_hole(file, offset, maxbytes);
+	}
+
+	return -EINVAL;
+}
+
+const struct file_operations ext4_file_operations = {
+	.llseek		= ext4_llseek,
+	.read_iter	= ext4_file_read_iter,
+	.write_iter	= ext4_file_write_iter,
+	.unlocked_ioctl = ext4_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl	= ext4_compat_ioctl,
+#endif
+	.mmap		= ext4_file_mmap,
+	.open		= ext4_file_open,
+	.release	= ext4_release_file,
+	.fsync		= ext4_sync_file,
+	.get_unmapped_area = thp_get_unmapped_area,
+	.splice_read	= generic_file_splice_read,
+	.splice_write	= iter_file_splice_write,
+	.fallocate	= ext4_fallocate,
+};
+
+const struct inode_operations ext4_file_inode_operations = {
+	.setattr	= ext4_setattr,
+	.getattr	= ext4_file_getattr,
+	.listxattr	= ext4_listxattr,
+	.get_acl	= ext4_get_acl,
+	.set_acl	= ext4_set_acl,
+	.fiemap		= ext4_fiemap,
+};
+