[PATCH 6.2 180/242] f2fs: fix potential corruption when moving a directory

[Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>]

From: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>

commit d94772154e524b329a168678836745d2773a6e02 upstream.

F2FS has the same issue in ext4_rename causing crash revealed by
xfstests/generic/707.

See also commit 0813299c586b ("ext4: Fix possible corruption when moving a directory")

CC: stable@xxxxxxxxxxxxxxx
Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 fs/f2fs/namei.c |   16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

--- a/fs/f2fs/namei.c
+++ b/fs/f2fs/namei.c
@@ -998,12 +998,20 @@ static int f2fs_rename(struct user_names
 			goto out;
 	}
 
+	/*
+	 * Copied from ext4_rename: we need to protect against old.inode
+	 * directory getting converted from inline directory format into
+	 * a normal one.
+	 */
+	if (S_ISDIR(old_inode->i_mode))
+		inode_lock_nested(old_inode, I_MUTEX_NONDIR2);
+
 	err = -ENOENT;
 	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;
+		goto out_unlock_old;
 	}
 
 	if (S_ISDIR(old_inode->i_mode)) {
@@ -1111,6 +1119,9 @@ static int f2fs_rename(struct user_names
 
 	f2fs_unlock_op(sbi);
 
+	if (S_ISDIR(old_inode->i_mode))
+		inode_unlock(old_inode);
+
 	if (IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir))
 		f2fs_sync_fs(sbi->sb, 1);
 
@@ -1125,6 +1136,9 @@ out_dir:
 		f2fs_put_page(old_dir_page, 0);
 out_old:
 	f2fs_put_page(old_page, 0);
+out_unlock_old:
+	if (S_ISDIR(old_inode->i_mode))
+		inode_unlock(old_inode);
 out:
 	iput(whiteout);
 	return err;