lib/iscsi: Add nop_poller for iscsi polling group.

Change-Id: I7f0f64845a5b980632991e7b6d130e4be60ffa20
Signed-off-by: Ziye Yang <optimistyzy@gmail.com>
Reviewed-on: https://review.gerrithub.io/401749
Tested-by: SPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: Shuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>

lib/iscsi/conn.c

@@ -888,25 +888,33 @@ spdk_iscsi_get_pdu_length(struct spdk_iscsi_pdu *pdu, int header_digest,
 	return total;
 }
 
-static int
+void
 spdk_iscsi_conn_handle_nop(struct spdk_iscsi_conn *conn)
 {
 	uint64_t	tsc;
 
+	/**
+	  * This function will be executed by nop_poller of iSCSI polling group, so
+	  * we need to check the connection state first, then do the nop interval
+	  * expiration check work.
+	  */
+	if ((conn->state == ISCSI_CONN_STATE_EXITED) ||
+	    (conn->state == ISCSI_CONN_STATE_EXITING)) {
+		return;
+	}
+
 	/* Check for nop interval expiration */
 	tsc = spdk_get_ticks();
 	if (conn->nop_outstanding) {
 		if ((tsc - conn->last_nopin) > (conn->timeout  * spdk_get_ticks_hz())) {
 			SPDK_ERRLOG("Timed out waiting for NOP-Out response from initiator\n");
 			SPDK_ERRLOG("  tsc=0x%lx, last_nopin=0x%lx\n", tsc, conn->last_nopin);
-			return -1;
+			conn->state = ISCSI_CONN_STATE_EXITING;
 		}
 	} else if (tsc - conn->last_nopin > conn->nopininterval) {
 		conn->last_nopin = tsc;
 		spdk_iscsi_send_nopin(conn);
 	}
-
-	return 0;
 }
 
 /**
@@ -1153,8 +1161,6 @@ spdk_iscsi_conn_sock_cb(void *arg, struct spdk_sock_group *group, struct spdk_so
 static int
 spdk_iscsi_conn_execute(struct spdk_iscsi_conn *conn)
 {
-	int				rc = 0;
-
 	if (conn->state == ISCSI_CONN_STATE_EXITED) {
 		return -1;
 	}
@@ -1162,12 +1168,6 @@ spdk_iscsi_conn_execute(struct spdk_iscsi_conn *conn)
 	if (conn->state == ISCSI_CONN_STATE_EXITING) {
 		goto conn_exit;
 	}
-	/* Check for nop interval expiration */
-	rc = spdk_iscsi_conn_handle_nop(conn);
-	if (rc < 0) {
-		conn->state = ISCSI_CONN_STATE_EXITING;
-		goto conn_exit;
-	}
 
 	spdk_iscsi_conn_handle_queued_datain_tasks(conn);
 

lib/iscsi/conn.h

@@ -174,6 +174,7 @@ void spdk_shutdown_iscsi_conns(void);
 
 int spdk_iscsi_conn_construct(struct spdk_iscsi_portal *portal, struct spdk_sock *sock);
 void spdk_iscsi_conn_destruct(struct spdk_iscsi_conn *conn);
+void spdk_iscsi_conn_handle_nop(struct spdk_iscsi_conn *conn);
 void spdk_iscsi_conn_logout(struct spdk_iscsi_conn *conn);
 int spdk_iscsi_drop_conns(struct spdk_iscsi_conn *conn,
 			  const char *conn_match, int drop_all);

lib/iscsi/iscsi.h

@@ -259,6 +259,7 @@ struct spdk_iscsi_sess {
 struct spdk_iscsi_poll_group {
 	uint32_t					core;
 	struct spdk_poller				*poller;
+	struct spdk_poller				*nop_poller;
 	STAILQ_HEAD(connections, spdk_iscsi_conn)	connections;
 	struct spdk_sock_group				*sock_group;
 };

lib/iscsi/iscsi_subsystem.c

@@ -850,6 +850,17 @@ spdk_iscsi_poll_group_poll(void *ctx)
 	}
 }
 
+static void
+spdk_iscsi_poll_group_handle_nop(void *ctx)
+{
+	struct spdk_iscsi_poll_group *group = ctx;
+	struct spdk_iscsi_conn *conn, *tmp;
+
+	STAILQ_FOREACH_SAFE(conn, &group->connections, link, tmp) {
+		spdk_iscsi_conn_handle_nop(conn);
+	}
+}
+
 static void
 iscsi_create_poll_group_done(void *ctx)
 {
@@ -870,6 +881,8 @@ iscsi_create_poll_group(void *ctx)
 	assert(pg->sock_group != NULL);
 
 	pg->poller = spdk_poller_register(spdk_iscsi_poll_group_poll, pg, 0);
+	/* set the period to 1 sec */
+	pg->nop_poller = spdk_poller_register(spdk_iscsi_poll_group_handle_nop, pg, 1000000);
 }
 
 static void
@@ -884,6 +897,7 @@ iscsi_unregister_poll_group(void *ctx)
 
 	spdk_sock_group_close(&pg->sock_group);
 	spdk_poller_unregister(&pg->poller);
+	spdk_poller_unregister(&pg->nop_poller);
 }
 
 static void