[SCSI] sd: Issue correct protection operation

Use the same logic to prepare RD/WRPROTECT and the protection
operation.  Fixes a corner case where we could issue an unprotected
CDB and yet tell the HBA to do DIF to the drive.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

1 files changed, 4 insertions, 3 deletions

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index a7b53be6336..fec034557c3 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -384,7 +384,7 @@ static int sd_prep_fn(struct request_queue *q, struct request *rq)
         sector_t block = rq->sector;
         sector_t threshold;
         unsigned int this_count = rq->nr_sectors;
-        int ret;
+        int ret, host_dif;
 
         if (rq->cmd_type == REQ_TYPE_BLOCK_PC) {
                 ret = scsi_setup_blk_pc_cmnd(sdp, rq);
@@ -515,7 +515,8 @@ static int sd_prep_fn(struct request_queue *q, struct request *rq)
                                         rq->nr_sectors));
 
         /* Set RDPROTECT/WRPROTECT if disk is formatted with DIF */
-        if (scsi_host_dif_capable(sdp->host, sdkp->protection_type))
+        host_dif = scsi_host_dif_capable(sdp->host, sdkp->protection_type);
+        if (host_dif)
                 SCpnt->cmnd[1] = 1 << 5;
         else
                 SCpnt->cmnd[1] = 0;
@@ -573,7 +574,7 @@ static int sd_prep_fn(struct request_queue *q, struct request *rq)
         SCpnt->sdb.length = this_count * sdp->sector_size;
 
         /* If DIF or DIX is enabled, tell HBA how to handle request */
-        if (sdkp->protection_type || scsi_prot_sg_count(SCpnt))
+        if (host_dif || scsi_prot_sg_count(SCpnt))
                 sd_dif_op(SCpnt, sdkp->protection_type, scsi_prot_sg_count(SCpnt));
 
         /*