ext4: avoid buffer leak in ext4_orphan_add() after prior errors

BugLink: https://bugs.launchpad.net/bugs/1810947

commit feaf264c upstream.

Fixes: d745a8c2 ("ext4: reduce contention on s_orphan_lock")
Fixes: 6e3617e5 ("ext4: Handle non empty on-disk orphan link")
Cc: Dmitry Monakhov <dmonakhov@gmail.com>
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org # 2.6.34
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Juerg Haefliger <juergh@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

fs/ext4/namei.c

@@ -2830,7 +2830,9 @@ int ext4_orphan_add(handle_t *handle, struct inode *inode)
 			list_del_init(&EXT4_I(inode)->i_orphan);
 			mutex_unlock(&sbi->s_orphan_lock);
 		}
-	}
+	} else
+		brelse(iloc.bh);
+
 	jbd_debug(4, "superblock will point to %lu\n", inode->i_ino);
 	jbd_debug(4, "orphan inode %lu will point to %d\n",
 			inode->i_ino, NEXT_ORPHAN(inode));