Re: [PATCH v2 0/5] block/md/dm: set chunk_sectors from stacked dev stripe size
From: Nilay Shroff
Date: Fri Jun 20 2025 - 10:30:32 EST
On 6/18/25 2:07 PM, John Garry wrote:
> This value in io_min is used to configure any atomic write limit for the
> stacked device. The idea is that the atomic write unit max is a
> power-of-2 factor of the stripe size, and the stripe size is available
> in io_min.
>
> Using io_min causes issues, as:
> a. it may be mutated
> b. the check for io_min being set for determining if we are dealing with
> a striped device is hard to get right, as reported in [0].
>
> This series now sets chunk_sectors limit to share stripe size.
>
> [0] https://lore.kernel.org/linux-block/888f3b1d-7817-4007-b3b3-1a2ea04df771@xxxxxxxxxxxxx/T/#mecca17129f72811137d3c2f1e477634e77f06781
>
> Based on v6.16-rc2
I have validated this patchset using an NVMe disk supporting atomic write and
native NVMe multipath. I have also validated dm-stripe and raid configuration.
Overall the patchset looks good to me and fixes the issue I posted[1] earlier
with my NVMe disk.
[1]: https://lore.kernel.org/linux-block/888f3b1d-7817-4007-b3b3-1a2ea04df771@xxxxxxxxxxxxx/T/#mecca17129f72811137d3c2f1e477634e77f06781
Thanks,
--Nilay