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-Tag: firefly_0821_release~176^2~4^2~50^2~168
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=67aa7e6dd927c17103b3c5acb7eb50efb2372dab;p=firefly-linux-kernel-4.4.55.git

sd: Fix discard granularity when LBPRZ=1

commit 6540a65da90c09590897310e31993b1f6e28485a upstream.

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
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index bb669d32ccd0..cc84ea7d09cc 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;