On Wed, 2022-06-29 at 13:07 -0600, Keith Busch wrote: > On Wed, Jun 29, 2022 at 02:04:47PM -0400, Eric Farman wrote: > > s390 dasd > > > > This made me think to change my rootfs, and of course the problem > > goes > > away once on something like a SCSI volume. > > > > So crawling through the dasd (instead of virtio) driver and I > > finally > > find the point where a change to dma_alignment (which you mentioned > > earlier) would actually fit. > > > > Such a change fixes this for me, so I'll run it by our DASD guys. > > Thanks for your help and patience. > > I'm assuming there's some driver or device requirement that's making > this > necessary. Is the below driver change what you're looking for? Yup, that's exactly what I have (in dasd_eckd.c) and indeed gets things working again. Need to scrounge up some FBA volumes to test that configuration and the change there. > If so, I think > you might want this regardless of this direct-io patch just because > other > interfaces like blk_rq_map_user_iov() and blk_rq_aligned() align to > it. Good point. > > --- > diff --git a/drivers/s390/block/dasd_fba.c > b/drivers/s390/block/dasd_fba.c > index 60be7f7bf2d1..5c79fb02cded 100644 > --- a/drivers/s390/block/dasd_fba.c > +++ b/drivers/s390/block/dasd_fba.c > @@ -780,6 +780,7 @@ static void dasd_fba_setup_blk_queue(struct > dasd_block *block) > /* With page sized segments each segment can be translated into > one idaw/tidaw */ > blk_queue_max_segment_size(q, PAGE_SIZE); > blk_queue_segment_boundary(q, PAGE_SIZE - 1); > + blk_queue_dma_alignment(q, PAGE_SIZE - 1); > > q->limits.discard_granularity = logical_block_size; > > --
