/*
* resolve an indirect backref in the form (root_id, key, level)
* to a logical address
*/
static int __resolve_indirect_ref(struct btrfs_fs_info *fs_info,
struct btrfs_path *path, u64 time_seq,
struct __prelim_ref *ref,
struct ulist *parents,
const u64 *extent_item_pos)
{
struct btrfs_root *root;
struct btrfs_key root_key;
struct extent_buffer *eb;
int ret = 0;
int root_level;
int level = ref->level;
root_key.objectid = ref->root_id;
root_key.type = BTRFS_ROOT_ITEM_KEY;
root_key.offset = (u64)-1;
root = btrfs_read_fs_root_no_name(fs_info, &root_key);
if (IS_ERR(root)) {
ret = PTR_ERR(root);
goto out;
}
root_level = btrfs_old_root_level(root, time_seq);
if (root_level + 1 == level)
goto out;
path->lowest_level = level;
ret = btrfs_search_old_slot(root, &ref->key_for_search, path, time_seq);
pr_debug("search slot in root %llu (level %d, ref count %d) returned "
"%d for key (%llu %u %llu)\n",
(unsigned long long)ref->root_id, level, ref->count, ret,
(unsigned long long)ref->key_for_search.objectid,
ref->key_for_search.type,
(unsigned long long)ref->key_for_search.offset);
if (ret < 0)
goto out;
eb = path->nodes[level];
while (!eb) {
if (!level) {
WARN_ON(1);
ret = 1;
goto out;
}
level--;
eb = path->nodes[level];
}
ret = add_all_parents(root, path, parents, level, &ref->key_for_search,
time_seq, ref->wanted_disk_byte,
extent_item_pos);
out:
path->lowest_level = 0;
btrfs_release_path(path);
return ret;
}
/*
* resolve an indirect backref in the form (root_id, key, level)
* to a logical address
*/
static int __resolve_indirect_ref(struct btrfs_fs_info *fs_info,
struct btrfs_path *path, u64 time_seq,
struct __prelim_ref *ref,
struct ulist *parents,
const u64 *extent_item_pos, u64 total_refs)
{
struct btrfs_root *root;
struct btrfs_key root_key;
struct extent_buffer *eb;
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) {
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,
ref->key_for_search.objectid, ref->key_for_search.type,
ref->key_for_search.offset);
if (ret < 0)
goto out;
eb = path->nodes[level];
while (!eb) {
if (WARN_ON(!level)) {
ret = 1;
goto out;
}
level--;
eb = path->nodes[level];
}
ret = add_all_parents(root, path, parents, ref, level, time_seq,
extent_item_pos, total_refs);
out:
path->lowest_level = 0;
btrfs_release_path(path);
return ret;
}