btrfs: check the right error variable in btrfs_del_dir_entries_in_log

[ Upstream commit fb2fecbad50964b9f27a3b182e74e437b40753ef ]

With my new locking code dbench is so much faster that I tripped over a
transaction abort from ENOSPC.  This turned out to be because
btrfs_del_dir_entries_in_log was checking for ret == -ENOSPC, but this
function sets err on error, and returns err.  So instead of properly
marking the inode as needing a full commit, we were returning -ENOSPC
and aborting in __btrfs_unlink_inode.  Fix this by checking the proper
variable so that we return the correct thing in the case of ENOSPC.

The ENOENT needs to be checked, because btrfs_lookup_dir_item_index()
can return -ENOENT if the dir item isn't in the tree log (which would
happen if we hadn't fsync'ed this guy).  We actually handle that case in
__btrfs_unlink_inode, so it's an expected error to get back.

Fixes: 4a500fd178c8 ("Btrfs: Metadata ENOSPC handling for tree log")
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ add note and comment about ENOENT ]
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index c28ac9c464251ae25c63031be53febb788996fd8..5bd1758f57b64eeb1b216da0a2c85943ebc4ce84 100644 (file)
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -3191,11 +3191,13 @@ fail:
        btrfs_free_path(path);
 out_unlock:
        mutex_unlock(&BTRFS_I(dir)->log_mutex);
-       if (ret == -ENOSPC) {
+       if (err == -ENOSPC) {
                btrfs_set_log_full_commit(root->fs_info, trans);
-               ret = 0;
-       } else if (ret < 0)
-               btrfs_abort_transaction(trans, ret);
+               err = 0;
+       } else if (err < 0 && err != -ENOENT) {
+               /* ENOENT can be returned if the entry hasn't been fsynced yet */
+               btrfs_abort_transaction(trans, err);
+       }
 
        btrfs_end_log_trans(root);