----- Original Message ----- > From: "Fam Zheng" <[email protected]> > To: [email protected] > Cc: "Martin K. Petersen" <[email protected]>, [email protected], > [email protected], "James E.J. > Bottomley" <[email protected]> > 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 <[email protected]> > --- > 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 <[email protected]>
