nvme: non-blocking I/O qpair connect for TCP in interrupt mode

c3y1huang · c3y1huang · commit 0ef3b183046a · 2025-07-07T07:29:18.000+08:00
longhorn/longhorn-9834

Signed-off-by: Chin-Ya Huang &lt;chin-ya.huang@suse.com&gt;
diff --git a/lib/nvme/nvme_transport.c b/lib/nvme/nvme_transport.c
@@ -523,7 +523,13 @@ nvme_transport_ctrlr_connect_qpair(struct spdk_nvme_ctrlr *ctrlr, struct spdk_nv
 		}
 	}
 
-	if (!qpair->async) {
+	/* For the TCP transport, we poll the I/O queue periodically using g_opts.nvme_ioq_poll_period_us,
+	 * and do no wait synchronously for the qpair to connect. This allows the NVMe-oF
+	 * initiator to send the command and gives the target an opportunity to process
+	 * and respond without blocking. This unblocks when the initiator and target
+	 * are running on the same host.
+	 */
+	if (!qpair->async && (ctrlr->trid.trtype != SPDK_NVME_TRANSPORT_TCP)) {
 		/* Busy wait until the qpair exits the connecting state */
 		while (nvme_qpair_get_state(qpair) == NVME_QPAIR_CONNECTING) {
 			if (qpair->poll_group && spdk_nvme_ctrlr_is_fabrics(ctrlr)) {

Original file line number	Diff line number	Diff line change
`@@ -523,7 +523,13 @@ nvme_transport_ctrlr_connect_qpair(struct spdk_nvme_ctrlr *ctrlr, struct spdk_nv`
`523`	`523`	`}`
`524`	`524`	`}`
`525`	`525`
`526`		`- if (!qpair->async) {`
	`526`	`+ /* For the TCP transport, we poll the I/O queue periodically using g_opts.nvme_ioq_poll_period_us,`
	`527`	`+ * and do no wait synchronously for the qpair to connect. This allows the NVMe-oF`
	`528`	`+ * initiator to send the command and gives the target an opportunity to process`
	`529`	`+ * and respond without blocking. This unblocks when the initiator and target`
	`530`	`+ * are running on the same host.`
	`531`	`+ */`
	`532`	`+ if (!qpair->async && (ctrlr->trid.trtype != SPDK_NVME_TRANSPORT_TCP)) {`
`527`	`533`	`/* Busy wait until the qpair exits the connecting state */`
`528`	`534`	`while (nvme_qpair_get_state(qpair) == NVME_QPAIR_CONNECTING) {`
`529`	`535`	`if (qpair->poll_group && spdk_nvme_ctrlr_is_fabrics(ctrlr)) {`