scsi: target: Fix sense key for invalid EXTENDED COPY request

TCM fails to pass the following tests in libiscsi:

  SCSI.ExtendedCopy.DescrType
  SCSI.ExtendedCopy.DescrLimits
  SCSI.ExtendedCopy.ParamHdr
  SCSI.ExtendedCopy.ValidSegDescr
  SCSI.ExtendedCopy.ValidTgtDescr

The xcopy code always returns the same NOT READY sense key for all detected
errors. Change the sense key for invalid requests to ILLEGAL REQUEST, and
for aborted transfers to COPY ABORTED.

Link: https://lore.kernel.org/r/20210803145410.80147-3-s.samoylenko@yadro.com
Fixes: d877d727 ("target: Fix a deadlock between the XCOPY code and iSCSI session shutdown")
Reviewed-by: David Disseldorp <ddiss@suse.de>
Reviewed-by: Roman Bolshakov <r.bolshakov@yadro.com>
Reviewed-by: Konstantin Shelekhin <k.shelekhin@yadro.com>
Signed-off-by: Sergey Samoylenko <s.samoylenko@yadro.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/target/target_core_xcopy.c

@@ -674,12 +674,16 @@ static void target_xcopy_do_work(struct work_struct *work)
 	unsigned int max_sectors;
 	int rc = 0;
 	unsigned short nolb, max_nolb, copied_nolb = 0;
+	sense_reason_t sense_rc;
 
-	if (target_parse_xcopy_cmd(xop) != TCM_NO_SENSE)
+	sense_rc = target_parse_xcopy_cmd(xop);
+	if (sense_rc != TCM_NO_SENSE)
 		goto err_free;
 
-	if (WARN_ON_ONCE(!xop->src_dev) || WARN_ON_ONCE(!xop->dst_dev))
+	if (WARN_ON_ONCE(!xop->src_dev) || WARN_ON_ONCE(!xop->dst_dev)) {
+		sense_rc = TCM_INVALID_PARAMETER_LIST;
 		goto err_free;
+	}
 
 	src_dev = xop->src_dev;
 	dst_dev = xop->dst_dev;
@@ -762,20 +766,20 @@ static void target_xcopy_do_work(struct work_struct *work)
 	return;
 
 out:
+	/*
+	 * The XCOPY command was aborted after some data was transferred.
+	 * Terminate command with CHECK CONDITION status, with the sense key
+	 * set to COPY ABORTED.
+	 */
+	sense_rc = TCM_COPY_TARGET_DEVICE_NOT_REACHABLE;
 	xcopy_pt_undepend_remotedev(xop);
 	target_free_sgl(xop->xop_data_sg, xop->xop_data_nents);
 
 err_free:
 	kfree(xop);
-	/*
-	 * Don't override an error scsi status if it has already been set
-	 */
-	if (ec_cmd->scsi_status == SAM_STAT_GOOD) {
-		pr_warn_ratelimited("target_xcopy_do_work: rc: %d, Setting X-COPY"
-			" CHECK_CONDITION -> sending response\n", rc);
-		ec_cmd->scsi_status = SAM_STAT_CHECK_CONDITION;
-	}
-	target_complete_cmd(ec_cmd, ec_cmd->scsi_status);
+	pr_warn_ratelimited("target_xcopy_do_work: rc: %d, sense: %u, XCOPY operation failed\n",
+			   rc, sense_rc);
+	target_complete_cmd_with_sense(ec_cmd, SAM_STAT_CHECK_CONDITION, sense_rc);
 }
 
 /*