> On 6/2/21 5:10 AM, Changheun Lee wrote:
> > Set max_bio_bytes same with queue max sectors. It will lead to fast bio
> > submit when bio size is over than queue max sectors. And it might be helpful
> > to align submit bio size in some case.
> >
> > Signed-off-by: Changheun Lee <nanich.lee@xxxxxxxxxxx>
> > ---
> > drivers/scsi/scsi_lib.c | 2 ++
> > 1 file changed, 2 insertions(+)
> >
> > diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
> > index 532304d42f00..f6269268b0e0 100644
> > --- a/drivers/scsi/scsi_lib.c
> > +++ b/drivers/scsi/scsi_lib.c
> > @@ -1837,6 +1837,8 @@ void __scsi_init_queue(struct Scsi_Host *shost, struct request_queue *q)
> > blk_queue_virt_boundary(q, shost->virt_boundary_mask);
> > dma_set_max_seg_size(dev, queue_max_segment_size(q));
> >
> > + blk_queue_max_bio_bytes(q, queue_max_sectors(q));
> > +
> > /*
> > * Set a reasonable default alignment: The larger of 32-byte (dword),
> > * which is a common minimum for HBAs, and the minimum DMA alignment,
>
> Has this patch been tested with dm-crypt on top of a SCSI device? I'm
> concerned that this patch will trigger data corruption with dm-crypt on
> top because the above change will make the following dm-crypt code fail
> for a sufficiently large bio:
>
> bio_add_page(clone, page, len, 0);
>
> When testing dm-crypt on top of this patch series, please change the
> above dm-crypt code into the following before running any tests:
>
> WARN_ON(bio_add_page(clone, page, len, 0) < len);
>
> Thanks,
>
> Bart.
I think it will be OK if nr_iovecs is not over BIO_MAX_VECS in
crypt_alloc_buffer(). Because page is added to bio in PAGE_SIZE as maximum,
and the minimum of max_bio_bytes is "BIO_MAX_VECS * PAGE_SIZE".
for (i = 0; i < nr_iovecs; i++) {
page = mempool_alloc(&cc->page_pool, gfp_mask);
if (!page) {
crypt_free_buffer_pages(cc, clone);
bio_put(clone);
gfp_mask |= __GFP_DIRECT_RECLAIM;
goto retry;
}
len = (remaining_size > PAGE_SIZE) ? PAGE_SIZE : remaining_size;
bio_add_page(clone, page, len, 0);
remaining_size -= len;
}
Anyway as your advise, I'm checking it in my test environment. There are no
problem by now yet. I'm testing with 1MB max_bio_bytes of SCSI, and UINT_MAX
max_bio_bytes of dm-crypt.
Thank you,
Changheun Lee.
