ocfs2: fix rename vs unlink race

If another node unlinks the destination while ocfs2_rename() is waiting on a
cluster lock, ocfs2_rename() simply logs an error and continues. This causes
a crash because the renaming node is now trying to delete a non-existent
inode. The correct solution is to return -ENOENT.
Signed-off-by: Srinivas Eeda <srinivas.eeda@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>

fs/ocfs2/namei.c

@@ -1105,9 +1105,16 @@ static int ocfs2_rename(struct inode *old_dir,
 		goto bail;
 	}
 
-	if (!new_de && new_inode)
-		mlog(ML_ERROR, "inode %lu does not exist in it's parent "
-		     "directory!", new_inode->i_ino);
+	if (!new_de && new_inode) {
+		/*
+		 * Target was unlinked by another node while we were
+		 * waiting to get to ocfs2_rename(). There isn't
+		 * anything we can do here to help the situation, so
+		 * bubble up the appropriate error.
+		 */
+		status = -ENOENT;
+		goto bail;
+	}
 
 	/* In case we need to overwrite an existing file, we blow it
 	 * away first */