3 files changed, 32 insertions, 1 deletions

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index b3dd55f52f71..a0c90a324f53 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -3386,6 +3386,8 @@ int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
 
 int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
                                     struct btrfs_root *root);
+int btrfs_setup_space_cache(struct btrfs_trans_handle *trans,
+                            struct btrfs_root *root);
 int btrfs_extent_readonly(struct btrfs_root *root, u64 bytenr);
 int btrfs_free_block_groups(struct btrfs_fs_info *info);
 int btrfs_read_block_groups(struct btrfs_root *root);
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 96c613bfe157..3ac3fefb1625 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -3325,6 +3325,32 @@ out:
         return ret;
 }
 
+int btrfs_setup_space_cache(struct btrfs_trans_handle *trans,
+                            struct btrfs_root *root)
+{
+        struct btrfs_block_group_cache *cache, *tmp;
+        struct btrfs_transaction *cur_trans = trans->transaction;
+        struct btrfs_path *path;
+
+        if (list_empty(&cur_trans->dirty_bgs) ||
+            !btrfs_test_opt(root, SPACE_CACHE))
+                return 0;
+
+        path = btrfs_alloc_path();
+        if (!path)
+                return -ENOMEM;
+
+        /* Could add new block groups, use _safe just in case */
+        list_for_each_entry_safe(cache, tmp, &cur_trans->dirty_bgs,
+                                 dirty_list) {
+                if (cache->disk_cache_state == BTRFS_DC_CLEAR)
+                        cache_save_setup(cache, trans, path);
+        }
+
+        btrfs_free_path(path);
+        return 0;
+}
+
 int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
                                    struct btrfs_root *root)
 {
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 2fe3ef5e9de3..932709af5163 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -1025,7 +1025,6 @@ static int update_cowonly_root(struct btrfs_trans_handle *trans,
         struct btrfs_root *tree_root = root->fs_info->tree_root;
 
         old_root_used = btrfs_root_used(&root->root_item);
-        btrfs_write_dirty_block_groups(trans, root);
 
         while (1) {
                 old_root_bytenr = btrfs_root_bytenr(&root->root_item);
@@ -1085,6 +1084,10 @@ static noinline int commit_cowonly_roots(struct btrfs_trans_handle *trans,
         if (ret)
                 return ret;
 
+        ret = btrfs_setup_space_cache(trans, root);
+        if (ret)
+                return ret;
+
         /* run_qgroups might have added some more refs */
         ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1);
         if (ret)