On Thu, May 23, 2024 at 11:44:05AM -0400, Mike Snitzer wrote: > a difference on larger IOs being formed (given it is virtual > scsi_debug devices). > > In any case, we know I can reproduce with this scsi_debug-based mptest > test and Marco has verified my fix resolves the issue on his FC > multipath testbed. > > But I've just floated a patch to elevate the fix to block core (based > on Ming's suggestion): > https://patchwork.kernel.org/project/dm-devel/patch/Zk9i7V2GRoHxBPRu@xxxxxxxxxx/ I still think that is wrong. Unfortunately I can't actually reproduce the issue locally, but I think we want sd to set the user_max_sectors and stack if you want to see the limits propagated, i.e. the combined patch below. In the longer run I need to get SCSI out of messing with max_sectors directly, and the blk-mq stacking to stop looking at it vs just the hardware limits (or just drop the check). diff --git a/block/blk-settings.c b/block/blk-settings.c index a7fe8e90240a6e..7a672021daee6a 100644 --- a/block/blk-settings.c +++ b/block/blk-settings.c @@ -611,6 +611,8 @@ int blk_stack_limits(struct queue_limits *t, struct queue_limits *b, unsigned int top, bottom, alignment, ret = 0; t->max_sectors = min_not_zero(t->max_sectors, b->max_sectors); + t->max_user_sectors = min_not_zero(t->max_user_sectors, + b->max_user_sectors); t->max_hw_sectors = min_not_zero(t->max_hw_sectors, b->max_hw_sectors); t->max_dev_sectors = min_not_zero(t->max_dev_sectors, b->max_dev_sectors); t->max_write_zeroes_sectors = min(t->max_write_zeroes_sectors, diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index 332eb9dac22d91..f6c822c9cbd2d3 100644 --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -3700,8 +3700,10 @@ static int sd_revalidate_disk(struct gendisk *disk) */ if (sdkp->first_scan || q->limits.max_sectors > q->limits.max_dev_sectors || - q->limits.max_sectors > q->limits.max_hw_sectors) + q->limits.max_sectors > q->limits.max_hw_sectors) { q->limits.max_sectors = rw_max; + q->limits.max_user_sectors = rw_max; + } sdkp->first_scan = 0;
