Re: [PATCH v5 05/28] btrfs: disallow space_cache in HMZONED mode

Johannes Thumshirn
2019-12-05T07:21:53Z

On Wed, Dec 04, 2019 at 05:17:12PM +0900, Naohiro Aota wrote:
[...]
> diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
> index 616f5abec267..d411574298f4 100644
> --- a/fs/btrfs/super.c
> +++ b/fs/btrfs/super.c
> @@ -442,8 +442,12 @@ int btrfs_parse_options(struct btrfs_fs_info *info, char *options,
> cache_gen = btrfs_super_cache_generation(info->super_copy);
> if (btrfs_fs_compat_ro(info, FREE_SPACE_TREE))
> btrfs_set_opt(info->mount_opt, FREE_SPACE_TREE);
> - else if (cache_gen)
> - btrfs_set_opt(info->mount_opt, SPACE_CACHE);
> + else if (cache_gen) {
> + if (btrfs_fs_incompat(info, HMZONED))
> + WARN_ON(1);
> + else
> + btrfs_set_opt(info->mount_opt, SPACE_CACHE);
> + }

I would probably write this as follows:
else if (cache_gen)
if (!WARN_ON(btrfs_fs_incompat(info, HMZONED)))
btrfs_set_opt(info->mount_opt, SPACE_CACHE);