target: Fix RESERVATION_CONFLICT status regression for iscsi-target special case

This patch fixes a regression introduced in v3.8-rc1 code where a failed
target_check_reservation() check in target_setup_cmd_from_cdb() was causing
an incorrect SAM_STAT_GOOD status to be returned during a WRITE operation
performed by an unregistered / unreserved iscsi initiator port.

This regression is only effecting iscsi-target due to a special case check
for TCM_RESERVATION_CONFLICT within iscsi_target_erl1.c:iscsit_execute_cmd(),
and was still correctly disallowing WRITE commands from backend submission
for unregistered / unreserved initiator ports, while returning the incorrect
SAM_STAT_GOOD status due to the missing SAM_STAT_RESERVATION_CONFLICT
assignment.

This regression was first introduced with:

commit de103c93aff0bed0ae984274e5dc8b95899badab
Author: Christoph Hellwig <hch@lst.de>
Date:   Tue Nov 6 12:24:09 2012 -0800

    target: pass sense_reason as a return value

Go ahead and re-add the missing SAM_STAT_RESERVATION_CONFLICT assignment
during a target_check_reservation() failure, so that iscsi-target code
sends the correct SCSI status.

All other fabrics using target_submit_cmd_*() with a RESERVATION_CONFLICT
call to transport_generic_request_failure() are not effected by this bug.

Reported-by: Jeff Leung <jleung@curriegrad2004.ca>
Cc: Christoph Hellwig <hch@lst.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

1 files changed, 3 insertions, 1 deletions

diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
index 2030b608136d..3243ea790eab 100644
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -1139,8 +1139,10 @@ target_setup_cmd_from_cdb(struct se_cmd *cmd, unsigned char *cdb)
                 return ret;
 
         ret = target_check_reservation(cmd);
-        if (ret)
+        if (ret) {
+                cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
                 return ret;
+        }
 
         ret = dev->transport->parse_cdb(cmd);
         if (ret)