[PATCH v2 01/12] scsi: sd: Fix sshdr use in read_capacity_16

[Mike Christie <michael.christie@oracle.com>]

If scsi_execute_cmd returns < 0, it doesn't initialize the sshdr, so we
shouldn't access the sshdr. If it returns 0, then the cmd executed
successfully, so there is no need to check the sshdr. This has us access
the sshdr when we get a return value > 0.

Signed-off-by: Mike Christie <michael.christie@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: John Garry <john.g.garry@oracle.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Martin Wilck <mwilck@suse.com>
---
 drivers/scsi/sd.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 83b6a3f3863b..0754949c9f55 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -2435,11 +2435,10 @@ static int read_capacity_16(struct scsi_disk *sdkp, struct scsi_device *sdp,
 		the_result = scsi_execute_cmd(sdp, cmd, REQ_OP_DRV_IN,
 					      buffer, RC16_LEN, SD_TIMEOUT,
 					      sdkp->max_retries, &exec_args);
-
-		if (media_not_present(sdkp, &sshdr))
-			return -ENODEV;
-
 		if (the_result > 0) {
+			if (media_not_present(sdkp, &sshdr))
+				return -ENODEV;
+
 			sense_valid = scsi_sense_valid(&sshdr);
 			if (sense_valid &&
 			    sshdr.sense_key == ILLEGAL_REQUEST &&
-- 
2.34.1