Re: [PATCH 03/13] btrfs: zoned: don't recheck the reclaim threshold of zoned block-groups

["Naohiro Aota" <Naohiro.Aota@wdc.com>]

On Wed Oct 14, 2026 at 9:03 PM JST, Johannes Thumshirn wrote:
> On a zoned filesystem, block-groups on sequential zones are append only
> and their usage can only go down. So there is no need to re-check if a
> such block-group still qualifies for being reclaimed, once it is on the
> list it needs to be reclaimed.
>
> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
> ---
>  fs/btrfs/block-group.c | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/fs/btrfs/block-group.c b/fs/btrfs/block-group.c
> index 34ce3bac45a3..bad55ab4cbb2 100644
> --- a/fs/btrfs/block-group.c
> +++ b/fs/btrfs/block-group.c
> @@ -2033,8 +2033,13 @@ static int btrfs_reclaim_block_group(struct btrfs_block_group *bg, int *reclaime
>  	 * being freed, pass in a fake giant value to skip that extra
>  	 * check, which is more meaningful when adding to the list in
>  	 * the first place.
> +	 *
> +	 * On zoned, block_groups placed on sequential zones are append only
> +	 * and their usage can only go down, so the block group still qualifies.
                                           ^ on full block group ?

>  	 */
> -	if (!should_reclaim_block_group(bg, bg->length)) {
> +	if (!(btrfs_zoned_bg_is_append_only(bg) &&
> +	      btrfs_zoned_bg_is_full(bg)) &&
> +	    !should_reclaim_block_group(bg, bg->length)) {
>  		spin_unlock(&bg->lock);
>  		spin_unlock(&space_info->lock);
>  		up_write(&space_info->groups_sem);