On 2022-05-04 23:14, David Sterba wrote:

quoted

This commit: `btrfs: zoned: relax the alignment constraint for zoned
devices` makes sure the zone size is BTRFS_STRIPE_LEN aligned (64K). So
even the npo2 zoned device should be aligned to `fs_info->sectorsize`,
which is typically 4k.

This was one of the comment that came from David Sterba:
https://lore.kernel.org/all/20220315142740.GU12643@twin.jikos.cz/ (local)
where he suggested to have some sane alignment for the zone sizes.

My idea of 'sane' value would be 1M, that we have 4K for sectors is
because of the 1:1 mapping to pages, but RAM sizes are on a different
scale than storage devices. The 4K is absolute minimum but if the page
size is taken as a basic constraint, ARM has 64K and there are some 256K
arches.

That is a good point. I think it is safe to have 1MB as the minimum
alignment so that it covers all architecture's page sizes. Thanks. I
will queue this up.