[PATCH for v4.9 LTS 15/86] scsi: sd: Fix wrong DPOFUA disable in sd_read_cache_type

From: Levin, Alexander (Sasha Levin)
Date: Sat Jun 17 2017 - 18:43:25 EST


From: Damien Le Moal <damien.lemoal@xxxxxxx>

[ Upstream commit 26f2819772af891dee2843e1f8662c58e5129d5f ]

Zoned block devices force the use of READ/WRITE(16) commands by setting
sdkp->use_16_for_rw and clearing sdkp->use_10_for_rw. This result in
DPOFUA always being disabled for these drives as the assumed use of
the deprecated READ/WRITE(6) commands only looks at sdkp->use_10_for_rw.
Strenghten the test by also checking that sdkp->use_16_for_rw is false.

Signed-off-by: Damien Le Moal <damien.lemoal@xxxxxxx>
Reviewed-by: Hannes Reinecke <hare@xxxxxxxx>
Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx>
---
drivers/scsi/sd.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 931af0793951..13ac7e57a35d 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -2572,7 +2572,8 @@ sd_read_cache_type(struct scsi_disk *sdkp, unsigned char *buffer)
if (sdp->broken_fua) {
sd_first_printk(KERN_NOTICE, sdkp, "Disabling FUA\n");
sdkp->DPOFUA = 0;
- } else if (sdkp->DPOFUA && !sdkp->device->use_10_for_rw) {
+ } else if (sdkp->DPOFUA && !sdkp->device->use_10_for_rw &&
+ !sdkp->device->use_16_for_rw) {
sd_first_printk(KERN_NOTICE, sdkp,
"Uses READ/WRITE(6), disabling FUA\n");
sdkp->DPOFUA = 0;
--
2.11.0