btrfs: Make btrfs_find_name_in_ext_backref return struct btrfs_inode_extref

btrfs_find_name_in_ext_backref returns either 0/1 depending on whether it
found a backref for the given name. If it returns true then the actual
inode_ref struct is returned in one of its parameters. That's pointless,
instead refactor the function such that it returns either a pointer
to the btrfs_inode_extref or NULL it it didn't find anything. This
streamlines the function calling convention.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/ctree.h

@@ -2803,11 +2803,9 @@ btrfs_lookup_inode_extref(struct btrfs_trans_handle *trans,
 struct btrfs_inode_ref *btrfs_find_name_in_backref(struct extent_buffer *leaf,
 						   int slot, const char *name,
 						   int name_len);
-int btrfs_find_name_in_ext_backref(struct extent_buffer *leaf, int slot,
-				   u64 ref_objectid, const char *name,
-				   int name_len,
-				   struct btrfs_inode_extref **extref_ret);
-
+struct btrfs_inode_extref *btrfs_find_name_in_ext_backref(
+		struct extent_buffer *leaf, int slot, u64 ref_objectid,
+		const char *name, int name_len);
 /* file-item.c */
 struct btrfs_dio_private;
 int btrfs_del_csums(struct btrfs_trans_handle *trans,

fs/btrfs/inode-item.c

@@ -34,10 +34,9 @@ struct btrfs_inode_ref *btrfs_find_name_in_backref(struct extent_buffer *leaf,
 	return NULL;
 }
 
-int btrfs_find_name_in_ext_backref(struct extent_buffer *leaf, int slot,
-				   u64 ref_objectid,
-				   const char *name, int name_len,
-				   struct btrfs_inode_extref **extref_ret)
+struct btrfs_inode_extref *btrfs_find_name_in_ext_backref(
+		struct extent_buffer *leaf, int slot, u64 ref_objectid,
+		const char *name, int name_len)
 {
 	struct btrfs_inode_extref *extref;
 	unsigned long ptr;
@@ -62,15 +61,12 @@ int btrfs_find_name_in_ext_backref(struct extent_buffer *leaf, int slot,
 
 		if (ref_name_len == name_len &&
 		    btrfs_inode_extref_parent(leaf, extref) == ref_objectid &&
-		    (memcmp_extent_buffer(leaf, name, name_ptr, name_len) == 0)) {
-			if (extref_ret)
-				*extref_ret = extref;
-			return 1;
-		}
+		    (memcmp_extent_buffer(leaf, name, name_ptr, name_len) == 0))
+			return extref;
 
 		cur_offset += ref_name_len + sizeof(*extref);
 	}
-	return 0;
+	return NULL;
 }
 
 /* Returns NULL if no extref found */
@@ -84,7 +80,6 @@ btrfs_lookup_inode_extref(struct btrfs_trans_handle *trans,
 {
 	int ret;
 	struct btrfs_key key;
-	struct btrfs_inode_extref *extref;
 
 	key.objectid = inode_objectid;
 	key.type = BTRFS_INODE_EXTREF_KEY;
@@ -95,11 +90,9 @@ btrfs_lookup_inode_extref(struct btrfs_trans_handle *trans,
 		return ERR_PTR(ret);
 	if (ret > 0)
 		return NULL;
-	if (!btrfs_find_name_in_ext_backref(path->nodes[0], path->slots[0],
-					    ref_objectid, name, name_len,
-					    &extref))
-		return NULL;
-	return extref;
+	return btrfs_find_name_in_ext_backref(path->nodes[0], path->slots[0],
+					      ref_objectid, name, name_len);
+
 }
 
 static int btrfs_del_inode_extref(struct btrfs_trans_handle *trans,
@@ -139,9 +132,9 @@ static int btrfs_del_inode_extref(struct btrfs_trans_handle *trans,
 	 * This should always succeed so error here will make the FS
 	 * readonly.
 	 */
-	if (!btrfs_find_name_in_ext_backref(path->nodes[0], path->slots[0],
-					    ref_objectid,
-					    name, name_len, &extref)) {
+	extref = btrfs_find_name_in_ext_backref(path->nodes[0], path->slots[0],
+						ref_objectid, name, name_len);
+	if (!extref) {
 		btrfs_handle_fs_error(root->fs_info, -ENOENT, NULL);
 		ret = -EROFS;
 		goto out;
@@ -284,7 +277,7 @@ static int btrfs_insert_inode_extref(struct btrfs_trans_handle *trans,
 		if (btrfs_find_name_in_ext_backref(path->nodes[0],
 						   path->slots[0],
 						   ref_objectid,
-						   name, name_len, NULL))
+						   name, name_len))
 			goto out;
 
 		btrfs_extend_item(path, ins_len);

fs/btrfs/tree-log.c

@@ -968,7 +968,7 @@ static noinline int backref_in_log(struct btrfs_root *log,
 		if (btrfs_find_name_in_ext_backref(path->nodes[0],
 						   path->slots[0],
 						   ref_objectid,
-						   name, namelen, NULL))
+						   name, namelen))
 			match = 1;
 
 		goto out;
@@ -1267,9 +1267,9 @@ static int unlink_old_inode_refs(struct btrfs_trans_handle *trans,
 			goto out;
 
 		if (key->type == BTRFS_INODE_EXTREF_KEY)
-			ret = btrfs_find_name_in_ext_backref(log_eb, log_slot,
-							     parent_id, name,
-							     namelen, NULL);
+			ret = !!btrfs_find_name_in_ext_backref(log_eb, log_slot,
+							       parent_id, name,
+							       namelen);
 		else
 			ret = !!btrfs_find_name_in_backref(log_eb, log_slot,
 							   name, namelen);
@@ -1334,9 +1334,8 @@ static int btrfs_inode_ref_exists(struct inode *inode, struct inode *dir,
 		goto out;
 	}
 	if (key.type == BTRFS_INODE_EXTREF_KEY)
-		ret = btrfs_find_name_in_ext_backref(path->nodes[0],
-						     path->slots[0], parent_id,
-						     name, namelen, NULL);
+		ret = !!btrfs_find_name_in_ext_backref(path->nodes[0],
+				path->slots[0], parent_id, name, namelen);
 	else
 		ret = !!btrfs_find_name_in_backref(path->nodes[0], path->slots[0],
 						   name, namelen);