Re: [PATCH v3] btrfs: zoned: fix alloc_offset calculation for partly conventional block groups

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

On Fri Jun 6, 2025 at 4:17 PM JST, Johannes Thumshirn wrote:
> From: Johannes Thumshirn <johannes.thumshirn@wdc.com>
>
> When one of two zones composing a DUP block group is a conventional zone,
> we have the zone_info[i]->alloc_offset = WP_CONVENTIONAL. That will, of
> course, not match the write pointer of the other zone, and fails that
> block group.
>
> This commit solves that issue by properly recovering the emulated write
> pointer from the last allocated extent. The offset for the SINGLE, DUP,
> and RAID1 are straight-forward: it is same as the end of last allocated
> extent. The RAID0 and RAID10 are a bit tricky that we need to do the math
> of striping.
>
> This is the kernel equivalent of Naohiro's user-space commit:
> 1e85aa96e107 ("btrfs-progs: zoned: fix alloc_offset calculation for partly conventional block groups")
>
> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>

Reviewed-by: Naohiro Aota <naohiro.aota@wdc.com>

Thanks,