| Message ID | 20170327141831.20936-1-famz@redhat.com (mailing list archive) |
|---|---|
| State | Changes Requested, archived |
| Headers | show |
----- Original Message ----- > From: "Fam Zheng" <famz@redhat.com> > To: linux-kernel@vger.kernel.org > Cc: "Martin K. Petersen" <martin.petersen@oracle.com>, famz@redhat.com, linux-scsi@vger.kernel.org, "James E.J. > Bottomley" <jejb@linux.vnet.ibm.com> > Sent: Monday, March 27, 2017 10:18:31 AM > Subject: [PATCH] sd: Consider max_xfer_blocks if opt_xfer_blocks is unusable > > If device reports a small max_xfer_blocks and a zero opt_xfer_blocks, we > end up using BLK_DEF_MAX_SECTORS, which is wrong and r/w of that size > may get error. > > Fixes: ca369d51b3e ("block/sd: Fix device-imposed transfer length limits") > Signed-off-by: Fam Zheng <famz@redhat.com> > --- > drivers/scsi/sd.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c > index fcfeddc..e2e21ab 100644 > --- a/drivers/scsi/sd.c > +++ b/drivers/scsi/sd.c > @@ -2957,6 +2957,7 @@ static int sd_revalidate_disk(struct gendisk *disk) > rw_max = logical_to_sectors(sdp, sdkp->opt_xfer_blocks); > } else > rw_max = BLK_DEF_MAX_SECTORS; > + rw_max = min_not_zero(rw_max, dev_max); > > /* Combine with controller limits */ > q->limits.max_sectors = min(rw_max, queue_max_hw_sectors(q)); > -- > 2.9.3 > > Looks good to me and addresses the issue we faced. FInal confirmation this change is OK to come from Martin or James. Reviewed-by: Laurence Oberman <loberman@redhat.com>
Fam Zheng <famz@redhat.com> writes: Hi Fam, > --- a/drivers/scsi/sd.c > +++ b/drivers/scsi/sd.c > @@ -2957,6 +2957,7 @@ static int sd_revalidate_disk(struct gendisk *disk) > rw_max = logical_to_sectors(sdp, sdkp->opt_xfer_blocks); > } else > rw_max = BLK_DEF_MAX_SECTORS; > + rw_max = min_not_zero(rw_max, dev_max); rw_max is in sectors, dev_max is in logical blocks. > > /* Combine with controller limits */ > q->limits.max_sectors = min(rw_max, queue_max_hw_sectors(q));
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index fcfeddc..e2e21ab 100644 --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -2957,6 +2957,7 @@ static int sd_revalidate_disk(struct gendisk *disk) rw_max = logical_to_sectors(sdp, sdkp->opt_xfer_blocks); } else rw_max = BLK_DEF_MAX_SECTORS; + rw_max = min_not_zero(rw_max, dev_max); /* Combine with controller limits */ q->limits.max_sectors = min(rw_max, queue_max_hw_sectors(q));
If device reports a small max_xfer_blocks and a zero opt_xfer_blocks, we end up using BLK_DEF_MAX_SECTORS, which is wrong and r/w of that size may get error. Fixes: ca369d51b3e ("block/sd: Fix device-imposed transfer length limits") Signed-off-by: Fam Zheng <famz@redhat.com> --- drivers/scsi/sd.c | 1 + 1 file changed, 1 insertion(+)