From: Martin K. Petersen <martin.petersen@oracle.com>
Date: Sat, 5 Mar 2016 22:52:02 +0000 (-0500)
Subject: sd: Fix discard granularity when LBPRZ=1
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=f4327a95dd080ed6aecb185478a88ce1ee4fa3c4;p=linux-beck.git

sd: Fix discard granularity when LBPRZ=1

Commit 397737223c59 ("sd: Make discard granularity match logical block
size when LBPRZ=1") accidentally set the granularity to one byte instead
of one logical block on devices that provide deterministic zeroes after
UNMAP.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Reported-by: Mike Snitzer <snitzer@redhat.com>
Reviewed-by: Ewan Milne <emilne@redhat.com>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Fixes: 397737223c59e89dca7305feb6528caef8fbef84
Cc: <stable@vger.kernel.org> #v4.4+
---

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index d749da765df1..5a5457ac9cdb 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -648,7 +648,7 @@ static void sd_config_discard(struct scsi_disk *sdkp, unsigned int mode)
 	 */
 	if (sdkp->lbprz) {
 		q->limits.discard_alignment = 0;
-		q->limits.discard_granularity = 1;
+		q->limits.discard_granularity = logical_block_size;
 	} else {
 		q->limits.discard_alignment = sdkp->unmap_alignment *
 			logical_block_size;