[PATCH 4.5 037/238] sd: Fix discard granularity when LBPRZ=1

From: Greg Kroah-Hartman
Date: Sun Apr 10 2016 - 16:49:30 EST


4.5-stable review patch. If anyone has any objections, please let me know.

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

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

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@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: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/scsi/sd.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -648,7 +648,7 @@ 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;