nvme: Update spdk_nvme_wait_for_completion_timeout error handling

Update error handling of spdk_nvme_wait_for_completion_timeout to
differentiate cases when request is completed (possibly with error)
or polling was aborted by timeout or transport/device error
The function returns 0 on success, -ECANCELED if transport/device
error occurred or operation timed out and -EIO if the
request is completed with error

Change-Id: I314f40d1acaa6cfa9b88e5417b1ee2c9801bbbd6
Signed-off-by: Alexey Marchuk <alexeymar@mellanox.com>
Reviewed-on: https://review.gerrithub.io/c/spdk/spdk/+/481528
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Community-CI: Broadcom SPDK FC-NVMe CI <spdk-ci.pdl@broadcom.com>
Community-CI: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Changpeng Liu <changpeng.liu@intel.com>
Reviewed-by: Shuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>

lib/nvme/nvme.c

@@ -1,8 +1,8 @@
 /*-
  *   BSD LICENSE
  *
- *   Copyright (c) Intel Corporation.
+ *   Copyright (c) Intel Corporation. All rights reserved.
- *   All rights reserved.
+ *   Copyright (c) 2020 Mellanox Technologies LTD. All rights reserved.
  *
  *   Redistribution and use in source and binary forms, with or without
  *   modification, are permitted provided that the following conditions
@@ -143,12 +143,27 @@ spdk_nvme_wait_for_completion(struct spdk_nvme_qpair *qpair,
 	return spdk_nvme_wait_for_completion_robust_lock(qpair, status, NULL);
 }
 
+/**
+ * Poll qpair for completions until a command completes.
+ *
+ * \param qpair queue to poll
+ * \param status completion status
+ * \param timeout_in_secs optional timeout
+ *
+ * \return 0 if command completed without error,
+ * -EIO if command completed with error,
+ * -ECANCELED if command is not completed due to transport/device error or time expired
+ *
+ * The command to wait upon must be submitted with nvme_completion_poll_cb as the callback
+ * and status as the callback argument.
+ */
 int
 spdk_nvme_wait_for_completion_timeout(struct spdk_nvme_qpair *qpair,
 				      struct nvme_completion_poll_status *status,
 				      uint64_t timeout_in_secs)
 {
 	uint64_t timeout_tsc = 0;
+	int rc = 0;
 
 	memset(&status->cpl, 0, sizeof(status->cpl));
 	status->done = false;
@@ -157,14 +172,20 @@ spdk_nvme_wait_for_completion_timeout(struct spdk_nvme_qpair *qpair,
 	}
 
 	while (status->done == false) {
-		spdk_nvme_qpair_process_completions(qpair, 0);
+		rc = spdk_nvme_qpair_process_completions(qpair, 0);
+
+		if (rc < 0) {
+			status->cpl.status.sct = SPDK_NVME_SCT_GENERIC;
+			status->cpl.status.sc = SPDK_NVME_SC_ABORTED_SQ_DELETION;
+			break;
+		}
 		if (timeout_tsc && spdk_get_ticks() > timeout_tsc) {
 			break;
 		}
 	}
 
-	if (status->done == false) {
+	if (status->done == false || rc < 0) {
-		return -EIO;
+		return -ECANCELED;
 	}
 
 	return spdk_nvme_cpl_is_error(&status->cpl) ? -EIO : 0;

test/unit/lib/nvme/nvme.c/nvme_ut.c

@@ -1,8 +1,8 @@
 /*-
  *   BSD LICENSE
  *
- *   Copyright (c) Intel Corporation.
+ *   Copyright (c) Intel Corporation. All rights reserved.
- *   All rights reserved.
+ *   Copyright (c) 2020 Mellanox Technologies LTD. All rights reserved.
  *
  *   Redistribution and use in source and binary forms, with or without
  *   modification, are permitted provided that the following conditions
@@ -1210,14 +1210,16 @@ test_nvme_request_check_timeout(void)
 
 struct nvme_completion_poll_status g_status;
 uint64_t completion_delay, timeout_in_secs;
+int g_process_comp_result;
+
 int
 spdk_nvme_qpair_process_completions(struct spdk_nvme_qpair *qpair, uint32_t max_completions)
 {
 	spdk_delay_us(completion_delay * spdk_get_ticks_hz());
 
-	g_status.done = completion_delay < timeout_in_secs ? true : false;
+	g_status.done = completion_delay < timeout_in_secs && g_process_comp_result == 0 ? true : false;
 
-	return 0;
+	return g_process_comp_result;
 }
 
 static void
@@ -1235,7 +1237,19 @@ test_nvme_wait_for_completion(void)
 	g_status.done = true;
 	rc = spdk_nvme_wait_for_completion_timeout(&qpair, &g_status, timeout_in_secs);
 	CU_ASSERT(g_status.done == false);
-	CU_ASSERT(rc == -EIO);
+	CU_ASSERT(rc == -ECANCELED);
+
+	/* spdk_nvme_qpair_process_completions returns error */
+	g_process_comp_result = -1;
+	completion_delay = 1;
+	timeout_in_secs = 2;
+	rc = spdk_nvme_wait_for_completion_timeout(&qpair, &g_status, timeout_in_secs);
+	CU_ASSERT(rc == -ECANCELED);
+	CU_ASSERT(g_status.done == false);
+	CU_ASSERT(g_status.cpl.status.sct == SPDK_NVME_SCT_GENERIC);
+	CU_ASSERT(g_status.cpl.status.sc == SPDK_NVME_SC_ABORTED_SQ_DELETION);
+
+	g_process_comp_result = 0;
 
 	/* complete in time */
 	completion_delay = 1;