static int __add_block_group_free_space(struct btrfs_trans_handle *trans,
struct btrfs_block_group_cache *block_group,
struct btrfs_path *path)
{
int ret;
block_group->needs_free_space = 0;
ret = add_new_free_space_info(trans, block_group, path);
if (ret)
return ret;
return __add_to_free_space_tree(trans, block_group, path,
block_group->key.objectid,
block_group->key.offset);
}
/*
* Populate the free space tree by walking the extent tree. Operations on the
* extent tree that happen as a result of writes to the free space tree will go
* through the normal add/remove hooks.
*/
static int populate_free_space_tree(struct btrfs_trans_handle *trans,
struct btrfs_fs_info *fs_info,
struct btrfs_block_group_cache *block_group)
{
struct btrfs_root *extent_root = fs_info->extent_root;
struct btrfs_path *path, *path2;
struct btrfs_key key;
u64 start, end;
int ret;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
path->reada = 1;
path2 = btrfs_alloc_path();
if (!path2) {
btrfs_free_path(path);
return -ENOMEM;
}
ret = add_new_free_space_info(trans, fs_info, block_group, path2);
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
* end. Note that EXTENT_ITEM and METADATA_ITEM are less than
* BLOCK_GROUP_ITEM, so an extent may precede the block group that it's
* contained in.
*/
key.objectid = block_group->key.objectid;
key.type = BTRFS_EXTENT_ITEM_KEY;
key.offset = 0;
ret = btrfs_search_slot_for_read(extent_root, &key, path, 1, 0);
if (ret < 0)
goto out_locked;
ASSERT(ret == 0);
start = block_group->key.objectid;
end = block_group->key.objectid + block_group->key.offset;
while (1) {
btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
if (key.type == BTRFS_EXTENT_ITEM_KEY ||
key.type == BTRFS_METADATA_ITEM_KEY) {
if (key.objectid >= end)
break;
if (start < key.objectid) {
ret = __add_to_free_space_tree(trans, fs_info,
block_group,
path2, start,
key.objectid -
start);
if (ret)
goto out_locked;
}
start = key.objectid;
if (key.type == BTRFS_METADATA_ITEM_KEY)
start += fs_info->tree_root->nodesize;
else
start += key.offset;
} else if (key.type == BTRFS_BLOCK_GROUP_ITEM_KEY) {
if (key.objectid != block_group->key.objectid)
break;
}
ret = btrfs_next_item(extent_root, path);
if (ret < 0)
goto out_locked;
if (ret)
break;
}
if (start < end) {
ret = __add_to_free_space_tree(trans, fs_info, block_group,
path2, start, end - start);
if (ret)
goto out_locked;
}
ret = 0;
out_locked:
mutex_unlock(&block_group->free_space_lock);
out:
btrfs_free_path(path2);
btrfs_free_path(path);
return ret;
}