[PATCH 3.16 108/217] sd: Fix discard granularity when LBPRZ=1

[Ben Hutchings]

3.16.35-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: "Martin K. Petersen" <martin.petersen@xxxxxxxxxx>

commit f4327a95dd080ed6aecb185478a88ce1ee4fa3c4 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@xxxxxxxxxx>
Reported-by: Mike Snitzer <snitzer@xxxxxxxxxx>
Reviewed-by: Ewan Milne <emilne@xxxxxxxxxx>
Reviewed-by: Bart Van Assche <bart.vanassche@xxxxxxxxxxx>
Fixes: 397737223c59e89dca7305feb6528caef8fbef84
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 drivers/scsi/sd.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -638,7 +638,7 @@ static void sd_config_discard(struct scs
 	 */
 	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;