Btrfs: log recovery, don't unlink inode always on error

If we get any error while doing a dir index/item lookup in the
log tree, we were always unlinking the corresponding inode in
the subvolume. It makes sense to unlink only if the lookup failed
to find the dir index/item, which corresponds to NULL or -ENOENT,
and not when other errors happen (like a transient -ENOMEM or -EIO).
Signed-off-by: NFilipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

fs/btrfs/tree-log.c

@@ -1832,7 +1832,7 @@ static noinline int check_item_in_log(struct btrfs_trans_handle *trans,
 						     dir_key->offset,
 						     name, name_len, 0);
 		}
-		if (IS_ERR_OR_NULL(log_di)) {
+		if (!log_di || (IS_ERR(log_di) && PTR_ERR(log_di) == -ENOENT)) {
 			btrfs_dir_item_key_to_cpu(eb, di, &location);
 			btrfs_release_path(path);
 			btrfs_release_path(log_path);
@@ -1869,6 +1869,9 @@ static noinline int check_item_in_log(struct btrfs_trans_handle *trans,
 				goto again;
 			ret = 0;
 			goto out;
+		} else if (IS_ERR(log_di)) {
+			kfree(name);
+			return PTR_ERR(log_di);
 		}
 		btrfs_release_path(log_path);
 		kfree(name);