On 12/1/20 9:07 AM, Mike Snitzer wrote:
> commit 22ada802ede8 ("block: use lcm_not_zero() when stacking
> chunk_sectors") broke chunk_sectors limit stacking. chunk_sectors must
> reflect the most limited of all devices in the IO stack.
>
> Otherwise malformed IO may result. E.g.: prior to this fix,
> ->chunk_sectors = lcm_not_zero(8, 128) would result in
> blk_max_size_offset() splitting IO at 128 sectors rather than the
> required more restrictive 8 sectors.
>
> And since commit 07d098e6bbad ("block: allow 'chunk_sectors' to be
> non-power-of-2") care must be taken to properly stack chunk_sectors to
> be compatible with the possibility that a non-power-of-2 chunk_sectors
> may be stacked. This is why gcd() is used instead of reverting back
> to using min_not_zero().
Applied for 5.10, thanks.
--
Jens Axboe
--
dm-devel mailing list
dm-devel@xxxxxxxxxx
https://www.redhat.com/mailman/listinfo/dm-devel
