fs: btrfs: Imeplement btrfs_list_subvols() using new infrastructure

Reimplement btrfs_list_subvols() to use new code.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Marek Behún <marek.behun@nic.cz>
This commit is contained in:
Qu Wenruo 2020-06-24 18:03:14 +02:00 committed by Tom Rini
parent f48615276b
commit e8e95c7ee1

View File

@ -155,6 +155,72 @@ out:
return ret;
}
static int list_subvolums(struct btrfs_fs_info *fs_info)
{
struct btrfs_root *tree_root = fs_info->tree_root;
struct btrfs_root *root;
struct btrfs_path path;
struct btrfs_key key;
char *result;
int ret = 0;
result = malloc(PATH_MAX);
if (!result)
return -ENOMEM;
ret = list_one_subvol(fs_info->fs_root, result);
if (ret < 0)
goto out;
root = fs_info->fs_root;
printf("ID %llu gen %llu path %.*s\n",
root->root_key.objectid, btrfs_root_generation(&root->root_item),
PATH_MAX, result);
key.objectid = BTRFS_FIRST_FREE_OBJECTID;
key.type = BTRFS_ROOT_ITEM_KEY;
key.offset = 0;
btrfs_init_path(&path);
ret = btrfs_search_slot(NULL, tree_root, &key, &path, 0, 0);
if (ret < 0)
goto out;
while (1) {
if (path.slots[0] >= btrfs_header_nritems(path.nodes[0]))
goto next;
btrfs_item_key_to_cpu(path.nodes[0], &key, path.slots[0]);
if (key.objectid > BTRFS_LAST_FREE_OBJECTID)
break;
if (key.objectid < BTRFS_FIRST_FREE_OBJECTID ||
key.type != BTRFS_ROOT_ITEM_KEY)
goto next;
key.offset = (u64)-1;
root = btrfs_read_fs_root(fs_info, &key);
if (IS_ERR(root)) {
ret = PTR_ERR(root);
if (ret == -ENOENT)
goto next;
}
ret = list_one_subvol(root, result);
if (ret < 0)
goto out;
printf("ID %llu gen %llu path %.*s\n",
root->root_key.objectid,
btrfs_root_generation(&root->root_item),
PATH_MAX, result);
next:
ret = btrfs_next_item(tree_root, &path);
if (ret < 0)
goto out;
if (ret > 0) {
ret = 0;
break;
}
}
out:
free(result);
return ret;
}
static int get_subvol_name(u64 subvolid, char *name, int max_len)
{
struct btrfs_root_ref rref;
@ -268,10 +334,12 @@ static void list_subvols(u64 tree, char *nameptr, int max_name_len, int level)
void btrfs_list_subvols(void)
{
char *nameptr = malloc(4096);
struct btrfs_fs_info *fs_info = current_fs_info;
int ret;
list_subvols(BTRFS_FS_TREE_OBJECTID, nameptr, nameptr ? 4096 : 0, 40);
if (nameptr)
free(nameptr);
if (!fs_info)
return;
ret = list_subvolums(fs_info);
if (ret < 0)
error("failed to list subvolume: %d", ret);
}