f2fs: fix to avoid dirent corruption

[ Upstream commit 53edb54956 ]

As Al reported in link[1]:

f2fs_rename()
...
	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);

You want correct inumber in the ".." link.  And cross-directory
rename does move the source to new parent, even if you'd been asked
to leave a whiteout in the old place.

[1] https://lore.kernel.org/all/20231017055040.GN800259@ZenIV/

With below testcase, it may cause dirent corruption, due to it missed
to call f2fs_set_link() to update ".." link to new directory.
- mkdir -p dir/foo
- renameat2 -w dir/foo bar

[ASSERT] (__chk_dots_dentries:1421)  --> Bad inode number[0x4] for '..', parent parent ino is [0x3]
[FSCK] other corrupted bugs                           [Fail]

Fixes: 7e01e7ad74 ("f2fs: support RENAME_WHITEOUT")
Cc: Jan Kara <jack@suse.cz>
Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Chao Yu <chao@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Chao Yu 2023-11-28 17:25:16 +08:00 committed by Greg Kroah-Hartman
parent b083ec00f3
commit 5624a3c1b1

View file

@ -1009,7 +1009,7 @@ static int f2fs_rename(struct inode *old_dir, struct dentry *old_dentry,
}
if (old_dir_entry) {
if (old_dir != new_dir && !whiteout)
if (old_dir != new_dir)
f2fs_set_link(old_inode, old_dir_entry,
old_dir_page, new_dir);
else