[v3 2/2] scsi: target: fix sense key for invalid XCOPY request

[Sergey Samoylenko <s.samoylenko@yadro.com>]

TCM fails to pass the following tests in libiscsi:

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

XCOPY always returns the same NOT READY sense key for all
detected errors. It changes a sense key for invalid requests
to ILLEGAL REQUEST sense key, for aborted transferring data
(IO error and etc.) to COPY ABORTED.

Fixes: d877d7275be34ad ("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>
---
 drivers/target/target_core_xcopy.c | 26 +++++++++++++++-----------
 1 file changed, 15 insertions(+), 11 deletions(-)

diff --git a/drivers/target/target_core_xcopy.c b/drivers/target/target_core_xcopy.c
index 0f1319336f3e..d4fe7cb2bd00 100644
--- a/drivers/target/target_core_xcopy.c
+++ b/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);
 }
 
 /*
-- 
2.25.1