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Diffstat (limited to 'fs/btrfs/backref.c')
-rw-r--r--fs/btrfs/backref.c13
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,