ext4: Remove ext4 locking of moved directory

Remove locking of moved directory in ext4_rename2(). We will take care
of it in VFS instead. This effectively reverts commit 0813299c
("ext4: Fix possible corruption when moving a directory") and followup
fixes.

CC: Ted Tso <tytso@mit.edu>
CC: stable@vger.kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>
Message-Id: <20230601105830.13168-1-jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>

fs/ext4/namei.c

@@ -3834,19 +3834,10 @@ static int ext4_rename(struct mnt_idmap *idmap, struct inode *old_dir,
 			return retval;
 	}
 
-	/*
-	 * 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);
-
 	old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, &old.de,
 				 &old.inlined);
-	if (IS_ERR(old.bh)) {
-		retval = PTR_ERR(old.bh);
-		goto unlock_moved_dir;
-	}
+	if (IS_ERR(old.bh))
+		return PTR_ERR(old.bh);
 
 	/*
 	 *  Check for inode number is _not_ due to possible IO errors.
@@ -4043,10 +4034,6 @@ static int ext4_rename(struct mnt_idmap *idmap, struct inode *old_dir,
 	brelse(old.bh);
 	brelse(new.bh);
 
-unlock_moved_dir:
-	if (S_ISDIR(old.inode->i_mode))
-		inode_unlock(old.inode);
-
 	return retval;
 }