Btrfs: remove redundant code for dir item lookup

When we search a dir item with a specific hash code, we can
just return NULL without further checking if btrfs_search_slot()
returns 1.
Signed-off-by: NLi Zefan <lizf@cn.fujitsu.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

fs/btrfs/dir-item.c

@@ -198,8 +198,6 @@ struct btrfs_dir_item *btrfs_lookup_dir_item(struct btrfs_trans_handle *trans,
 	struct btrfs_key key;
 	int ins_len = mod < 0 ? -1 : 0;
 	int cow = mod != 0;
-	struct btrfs_key found_key;
-	struct extent_buffer *leaf;
 
 	key.objectid = dir;
 	btrfs_set_key_type(&key, BTRFS_DIR_ITEM_KEY);
@@ -209,18 +207,7 @@ struct btrfs_dir_item *btrfs_lookup_dir_item(struct btrfs_trans_handle *trans,
 	ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
 	if (ret < 0)
 		return ERR_PTR(ret);
-	if (ret > 0) {
-		if (path->slots[0] == 0)
-			return NULL;
-		path->slots[0]--;
-	}
-
-	leaf = path->nodes[0];
-	btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
-
-	if (found_key.objectid != dir ||
-	    btrfs_key_type(&found_key) != BTRFS_DIR_ITEM_KEY ||
-	    found_key.offset != key.offset)
+	if (ret > 0)
 		return NULL;
 
 	return btrfs_match_dir_item_name(root, path, name, name_len);
@@ -315,8 +302,6 @@ struct btrfs_dir_item *btrfs_lookup_xattr(struct btrfs_trans_handle *trans,
 	struct btrfs_key key;
 	int ins_len = mod < 0 ? -1 : 0;
 	int cow = mod != 0;
-	struct btrfs_key found_key;
-	struct extent_buffer *leaf;
 
 	key.objectid = dir;
 	btrfs_set_key_type(&key, BTRFS_XATTR_ITEM_KEY);
@@ -324,18 +309,7 @@ struct btrfs_dir_item *btrfs_lookup_xattr(struct btrfs_trans_handle *trans,
 	ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
 	if (ret < 0)
 		return ERR_PTR(ret);
-	if (ret > 0) {
-		if (path->slots[0] == 0)
-			return NULL;
-		path->slots[0]--;
-	}
-
-	leaf = path->nodes[0];
-	btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
-
-	if (found_key.objectid != dir ||
-	    btrfs_key_type(&found_key) != BTRFS_XATTR_ITEM_KEY ||
-	    found_key.offset != key.offset)
+	if (ret > 0)
 		return NULL;
 
 	return btrfs_match_dir_item_name(root, path, name, name_len);