From d0eb20a863ba7dc1d3f4b841639671f134560be2 Mon Sep 17 00:00:00 2001
From: "Martin K. Petersen" <martin.petersen@oracle.com>
Date: Wed, 20 Jan 2016 11:01:23 -0500
Subject: sd: Optimal I/O size is in bytes, not sectors

Commit ca369d51b3e1 ("block/sd: Fix device-imposed transfer length
limits") accidentally switched optimal I/O size reporting from bytes to
block layer sectors.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Reported-by: Christian Borntraeger <borntraeger@de.ibm.com>
Tested-by: Christian Borntraeger <borntraeger@de.ibm.com>
Fixes: ca369d51b3e1649be4a72addd6d6a168cfb3f537
Cc: stable@vger.kernel.org # 4.4+
Reviewed-by: James E.J. Bottomley <James.Bottomley@HansenPartnership.com>
Reviewed-by: Ewan D. Milne <emilne@redhat.com>
Reviewed-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 4e08d1cd..ec163d0 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -2893,7 +2893,7 @@ static int sd_revalidate_disk(struct gendisk *disk)
 	    sdkp->opt_xfer_blocks <= SD_DEF_XFER_BLOCKS &&
 	    sdkp->opt_xfer_blocks * sdp->sector_size >= PAGE_CACHE_SIZE)
 		rw_max = q->limits.io_opt =
-			logical_to_sectors(sdp, sdkp->opt_xfer_blocks);
+			sdkp->opt_xfer_blocks * sdp->sector_size;
 	else
 		rw_max = BLK_DEF_MAX_SECTORS;
 
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