diff options
| -rw-r--r-- | fs/btrfs/backref.c | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c index 15384968a84a..10ae5700ab1e 100644 --- a/fs/btrfs/backref.c +++ b/fs/btrfs/backref.c @@ -301,23 +301,34 @@ static int __resolve_indirect_ref(struct btrfs_fs_info *fs_info, int ret = 0; int root_level; int level = ref->level; + int index; root_key.objectid = ref->root_id; root_key.type = BTRFS_ROOT_ITEM_KEY; root_key.offset = (u64)-1; + + index = srcu_read_lock(&fs_info->subvol_srcu); + root = btrfs_read_fs_root_no_name(fs_info, &root_key); if (IS_ERR(root)) { + srcu_read_unlock(&fs_info->subvol_srcu, index); ret = PTR_ERR(root); goto out; } root_level = btrfs_old_root_level(root, time_seq); - if (root_level + 1 == level) + if (root_level + 1 == level) { + srcu_read_unlock(&fs_info->subvol_srcu, index); goto out; + } path->lowest_level = level; ret = btrfs_search_old_slot(root, &ref->key_for_search, path, time_seq); + + /* root node has been locked, we can release @subvol_srcu safely here */ + srcu_read_unlock(&fs_info->subvol_srcu, index); + pr_debug("search slot in root %llu (level %d, ref count %d) returned " "%d for key (%llu %u %llu)\n", ref->root_id, level, ref->count, ret, |
