btrfs: don't run delayed references while we are creating the free space tree
This is a short term solution to make sure btrfs_run_delayed_refs()
doesn't change the extent tree while we are scanning it to create the
free space tree.
Longer term we need to synchronize scanning the block groups one by one,
similar to what happens during a balance.
Signed-off-by: Chris Mason <clm@fb.com>
diff --git a/fs/btrfs/free-space-tree.c b/fs/btrfs/free-space-tree.c
index cbe36dd..393e36b 100644
--- a/fs/btrfs/free-space-tree.c
+++ b/fs/btrfs/free-space-tree.c
@@ -1067,6 +1067,8 @@
if (ret)
goto out;
+ mutex_lock(&block_group->free_space_lock);
+
/*
* Iterate through all of the extent and metadata items in this block
* group, adding the free space between them and the free space at the
@@ -1080,7 +1082,7 @@
ret = btrfs_search_slot_for_read(extent_root, &key, path, 1, 0);
if (ret < 0)
- goto out;
+ goto out_locked;
ASSERT(ret == 0);
start = block_group->key.objectid;
@@ -1100,7 +1102,7 @@
key.objectid -
start);
if (ret)
- goto out;
+ goto out_locked;
}
start = key.objectid;
if (key.type == BTRFS_METADATA_ITEM_KEY)
@@ -1114,7 +1116,7 @@
ret = btrfs_next_item(extent_root, path);
if (ret < 0)
- goto out;
+ goto out_locked;
if (ret)
break;
}
@@ -1122,10 +1124,12 @@
ret = __add_to_free_space_tree(trans, fs_info, block_group,
path2, start, end - start);
if (ret)
- goto out;
+ goto out_locked;
}
ret = 0;
+out_locked:
+ mutex_unlock(&block_group->free_space_lock);
out:
btrfs_free_path(path2);
btrfs_free_path(path);
@@ -1145,6 +1149,7 @@
if (IS_ERR(trans))
return PTR_ERR(trans);
+ fs_info->creating_free_space_tree = 1;
free_space_root = btrfs_create_tree(trans, fs_info,
BTRFS_FREE_SPACE_TREE_OBJECTID);
if (IS_ERR(free_space_root)) {
@@ -1164,6 +1169,7 @@
}
btrfs_set_fs_compat_ro(fs_info, FREE_SPACE_TREE);
+ fs_info->creating_free_space_tree = 0;
ret = btrfs_commit_transaction(trans, tree_root);
if (ret)
@@ -1172,6 +1178,7 @@
return 0;
abort:
+ fs_info->creating_free_space_tree = 0;
btrfs_abort_transaction(trans, tree_root, ret);
btrfs_end_transaction(trans, tree_root);
return ret;