btrfs: split inode rextef processing from __add_inode_ref() into a helper

The __add_inode_ref() function is quite big and with too much nesting, so
move the code that processes inode extrefs into a helper function, to make
the function easier to read and reduce the level of indentation too.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>

Author: fdmanana

fs/btrfs/tree-log.c

@@ -1094,6 +1094,73 @@ static int unlink_refs_not_in_log(struct btrfs_trans_handle *trans,
 	return 0;
 }
 
+static int unlink_extrefs_not_in_log(struct btrfs_trans_handle *trans,
+				     struct btrfs_path *path,
+				     struct btrfs_root *root,
+				     struct btrfs_root *log_root,
+				     struct btrfs_key *search_key,
+				     struct btrfs_inode *inode,
+				     u64 inode_objectid,
+				     u64 parent_objectid)
+{
+	struct extent_buffer *leaf = path->nodes[0];
+	const unsigned long base = btrfs_item_ptr_offset(leaf, path->slots[0]);
+	const u32 item_size = btrfs_item_size(leaf, path->slots[0]);
+	u32 cur_offset = 0;
+
+	while (cur_offset < item_size) {
+		struct btrfs_inode_extref *extref;
+		struct btrfs_inode *victim_parent;
+		struct fscrypt_str victim_name;
+		int ret;
+
+		extref = (struct btrfs_inode_extref *)(base + cur_offset);
+		victim_name.len = btrfs_inode_extref_name_len(leaf, extref);
+
+		if (btrfs_inode_extref_parent(leaf, extref) != parent_objectid)
+			goto next;
+
+		ret = read_alloc_one_name(leaf, &extref->name, victim_name.len,
+					  &victim_name);
+		if (ret)
+			return ret;
+
+		search_key->objectid = inode_objectid;
+		search_key->type = BTRFS_INODE_EXTREF_KEY;
+		search_key->offset = btrfs_extref_hash(parent_objectid,
+						       victim_name.name,
+						       victim_name.len);
+		ret = backref_in_log(log_root, search_key, parent_objectid, &victim_name);
+		if (ret) {
+			kfree(victim_name.name);
+			if (ret < 0)
+				return ret;
+next:
+			cur_offset += victim_name.len + sizeof(*extref);
+			continue;
+		}
+
+		victim_parent = btrfs_iget_logging(parent_objectid, root);
+		if (IS_ERR(victim_parent)) {
+			kfree(victim_name.name);
+			return PTR_ERR(victim_parent);
+		}
+
+		inc_nlink(&inode->vfs_inode);
+		btrfs_release_path(path);
+
+		ret = unlink_inode_for_log_replay(trans, victim_parent, inode,
+						  &victim_name);
+		iput(&victim_parent->vfs_inode);
+		kfree(victim_name.name);
+		if (ret)
+			return ret;
+		return -EAGAIN;
+	}
+
+	return 0;
+}
+
 static inline int __add_inode_ref(struct btrfs_trans_handle *trans,
 				  struct btrfs_root *root,
 				  struct btrfs_path *path,
@@ -1104,7 +1171,6 @@ static inline int __add_inode_ref(struct btrfs_trans_handle *trans,
 				  u64 ref_index, struct fscrypt_str *name)
 {
 	int ret;
-	struct extent_buffer *leaf;
 	struct btrfs_dir_item *di;
 	struct btrfs_key search_key;
 	struct btrfs_inode_extref *extref;
@@ -1139,62 +1205,13 @@ static inline int __add_inode_ref(struct btrfs_trans_handle *trans,
 	if (IS_ERR(extref)) {
 		return PTR_ERR(extref);
 	} else if (extref) {
-		u32 item_size;
-		u32 cur_offset = 0;
-		unsigned long base;
-		struct btrfs_inode *victim_parent;
-
-		leaf = path->nodes[0];
-
-		item_size = btrfs_item_size(leaf, path->slots[0]);
-		base = btrfs_item_ptr_offset(leaf, path->slots[0]);
-
-		while (cur_offset < item_size) {
-			struct fscrypt_str victim_name;
-
-			extref = (struct btrfs_inode_extref *)(base + cur_offset);
-			victim_name.len = btrfs_inode_extref_name_len(leaf, extref);
-
-			if (btrfs_inode_extref_parent(leaf, extref) != parent_objectid)
-				goto next;
-
-			ret = read_alloc_one_name(leaf, &extref->name,
-						  victim_name.len, &victim_name);
-			if (ret)
-				return ret;
-
-			search_key.objectid = inode_objectid;
-			search_key.type = BTRFS_INODE_EXTREF_KEY;
-			search_key.offset = btrfs_extref_hash(parent_objectid,
-							      victim_name.name,
-							      victim_name.len);
-			ret = backref_in_log(log_root, &search_key,
-					     parent_objectid, &victim_name);
-			if (ret < 0) {
-				kfree(victim_name.name);
-				return ret;
-			} else if (!ret) {
-				victim_parent = btrfs_iget_logging(parent_objectid, root);
-				if (IS_ERR(victim_parent)) {
-					ret = PTR_ERR(victim_parent);
-				} else {
-					inc_nlink(&inode->vfs_inode);
-					btrfs_release_path(path);
-
-					ret = unlink_inode_for_log_replay(trans,
-							victim_parent,
-							inode, &victim_name);
-					iput(&victim_parent->vfs_inode);
-				}
-				kfree(victim_name.name);
-				if (ret)
-					return ret;
-				goto again;
-			}
-			kfree(victim_name.name);
-next:
-			cur_offset += victim_name.len + sizeof(*extref);
-		}
+		ret = unlink_extrefs_not_in_log(trans, path, root, log_root,
+						&search_key, inode,
+						inode_objectid, parent_objectid);
+		if (ret == -EAGAIN)
+			goto again;
+		else if (ret)
+			return ret;
 	}
 	btrfs_release_path(path);