Commit d3b01064 authored by Li Zefan's avatar Li Zefan Committed by Chris Mason
Browse files

btrfs: fix locking issues in find_parent_nodes() 



- We might unlock head->mutex while it was not locked
- We might leave the function without unlocking delayed_refs->lock

Signed-off-by: default avatarLi Zefan <lizf@cn.fujitsu.com>
Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
parent e77266e4

fs/btrfs/backref.c

+6 −2
Original line number Diff line number Diff line
@@ -583,7 +583,7 @@ static int find_parent_nodes(struct btrfs_trans_handle *trans, 
	struct btrfs_path *path;

	struct btrfs_key info_key = { 0 };

	struct btrfs_delayed_ref_root *delayed_refs = NULL;

	struct btrfs_delayed_ref_head *head = NULL;

	struct btrfs_delayed_ref_head *head;

	int info_level = 0;

	int ret;

	struct list_head prefs_delayed;
@@ -607,6 +607,8 @@ static int find_parent_nodes(struct btrfs_trans_handle *trans, 
	 * at a specified point in time

	 */

again:

	head = NULL;



	ret = btrfs_search_slot(trans, fs_info->extent_root, &key, path, 0, 0);

	if (ret < 0)

		goto out;
@@ -635,9 +637,11 @@ static int find_parent_nodes(struct btrfs_trans_handle *trans, 
			goto again;

		}

		ret = __add_delayed_refs(head, seq, &info_key, &prefs_delayed);

		if (ret)

		if (ret) {

			spin_unlock(&delayed_refs->lock);

			goto out;

		}

	}

	spin_unlock(&delayed_refs->lock);



	if (path->slots[0]) {