On Sun, Apr 07 2024 at 9:19P -0400,
Ming Lei <ming.lei@xxxxxxxxxx> wrote:
> When one stacking device is over one device with virt_boundary_mask and
> another one with max segment size, the stacking device have both limits
> set. This way is allowed before d690cb8ae14b ("block: add an API to
> atomically update queue limits").
>
> Relax the limit so that we won't break such kind of stacking setting.
>
> Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218687
> Reported-by: janpieter.sollie@xxxxxxxxx
> Fixes: d690cb8ae14b ("block: add an API to atomically update queue limits")
> Link: https://lore.kernel.org/linux-block/ZfGl8HzUpiOxCLm3@fedora/
> Cc: Christoph Hellwig <hch@xxxxxx>
> Cc: Mike Snitzer <snitzer@xxxxxxxxxx>
> Cc: dm-devel@xxxxxxxxxxxxxxx
> Cc: Song Liu <song@xxxxxxxxxx>
> Cc: linux-raid@xxxxxxxxxxxxxxx
> Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxx>
> ---
> block/blk-settings.c | 16 ++++++----------
> 1 file changed, 6 insertions(+), 10 deletions(-)
>
> diff --git a/block/blk-settings.c b/block/blk-settings.c
> index cdbaef159c4b..d2731843f2fc 100644
> --- a/block/blk-settings.c
> +++ b/block/blk-settings.c
> @@ -182,17 +182,13 @@ static int blk_validate_limits(struct queue_limits *lim)
> return -EINVAL;
>
> /*
> - * Devices that require a virtual boundary do not support scatter/gather
> - * I/O natively, but instead require a descriptor list entry for each
> - * page (which might not be identical to the Linux PAGE_SIZE). Because
> - * of that they are not limited by our notion of "segment size".
> + * Stacking device may have both virtual boundary and max segment
> + * size limit, so allow this setting now, and long-term the two
> + * might need to move out of stacking limits since we have immutable
> + * bvec and lower layer bio splitting is supposed to handle the two
> + * correctly.
> */
> - if (lim->virt_boundary_mask) {
> - if (WARN_ON_ONCE(lim->max_segment_size &&
> - lim->max_segment_size != UINT_MAX))
> - return -EINVAL;
> - lim->max_segment_size = UINT_MAX;
> - } else {
> + if (!lim->virt_boundary_mask) {
> /*
> * The maximum segment size has an odd historic 64k default that
> * drivers probably should override. Just like the I/O size we
> --
> 2.41.0
>
Reviewed-by: Mike Snitzer <snitzer@xxxxxxxxxx>
