[PATCH] scsi: libiscsi: Set expecting_cc_ua flag when stop_conn

[Xiang Zhang]

Initiator need to recover session and reconnect to target, after calling stop_conn. And target will rebuild new session info, and mark ASC_POWERON_RESET ua sense for scsi devices belong to the target(device reset). After recovery, first scsi command(scmd) request to target will get ASC_POWERON_RESET(ua sense) + SAM_STAT_CHECK_CONDITION(status) in response.
According to scsi code: "scsi_done --> scsi_complete --> scsi_decide_disposition --> scsi_check_sense", if expecting_cc_ua = 0, scmd response with ASC_POWERON_RESET(ua sense) will ignore "cmd->retries <= cmd->allowed", fail directly. It will cause SCSI return io_error to upper layer without retry.
If we set expecting_cc_ua=1 in fail_scsi_tasks, SISC will retry the scmd which is response with ASC_POWERON_RESET. The scmd second request to target can successful, because target will clear ASC_POWERON_RESET in device pending ua_sense_list after first scmd request.

Signed-off-by: Xiang Zhang <hawkxiang.cpp@xxxxxxxxx>
---
 drivers/scsi/libiscsi.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c
index 0fda8905eabd..317e57be32b3 100644
--- a/drivers/scsi/libiscsi.c
+++ b/drivers/scsi/libiscsi.c
@@ -629,9 +629,10 @@ static void __fail_scsi_task(struct iscsi_task *task, int err)
 		conn->session->queued_cmdsn--;
 		/* it was never sent so just complete like normal */
 		state = ISCSI_TASK_COMPLETED;
-	} else if (err == DID_TRANSPORT_DISRUPTED)
+	} else if (err == DID_TRANSPORT_DISRUPTED) {
 		state = ISCSI_TASK_ABRT_SESS_RECOV;
-	else
+		sc->device->expecting_cc_ua = 1;
+	} else
 		state = ISCSI_TASK_ABRT_TMF;
 
 	sc = task->sc;
-- 
2.44.0