Use refcnt API for struct rtentry instead of hand-crafted atomic

operations.
OK mvs@

4 files changed, 27 insertions, 33 deletions

diff --git a/sys/net/route.c b/sys/net/route.c
index c9b83e892ba..bafadfd9e7c 100644
--- a/sys/net/route.c
+++ b/sys/net/route.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: route.c,v 1.411 2022/06/27 21:26:46 claudio Exp $	*/
+/*	$OpenBSD: route.c,v 1.412 2022/06/28 10:01:13 bluhm Exp $	*/
 /*	$NetBSD: route.c,v 1.14 1996/02/13 22:00:46 christos Exp $	*/
 
 /*
@@ -488,40 +488,34 @@ rt_putgwroute(struct rtentry *rt)
 void
 rtref(struct rtentry *rt)
 {
-	atomic_inc_int(&rt->rt_refcnt);
+	refcnt_take(&rt->rt_refcnt);
 }
 
 void
 rtfree(struct rtentry *rt)
 {
-	int		 refcnt;
-
 	if (rt == NULL)
 		return;
 
-	refcnt = (int)atomic_dec_int_nv(&rt->rt_refcnt);
-	if (refcnt <= 0) {
-		KASSERT(!ISSET(rt->rt_flags, RTF_UP));
-		KASSERT(!RT_ROOT(rt));
-		atomic_dec_int(&rttrash);
-		if (refcnt < 0) {
-			printf("rtfree: %p not freed (neg refs)\n", rt);
-			return;
-		}
+	if (refcnt_rele(&rt->rt_refcnt) == 0)
+		return;
+
+	KASSERT(!ISSET(rt->rt_flags, RTF_UP));
+	KASSERT(!RT_ROOT(rt));
+	atomic_dec_int(&rttrash);
 
-		KERNEL_LOCK();
-		rt_timer_remove_all(rt);
-		ifafree(rt->rt_ifa);
-		rtlabel_unref(rt->rt_labelid);
+	KERNEL_LOCK();
+	rt_timer_remove_all(rt);
+	ifafree(rt->rt_ifa);
+	rtlabel_unref(rt->rt_labelid);
 #ifdef MPLS
-		rt_mpls_clear(rt);
+	rt_mpls_clear(rt);
 #endif
-		free(rt->rt_gateway, M_RTABLE, ROUNDUP(rt->rt_gateway->sa_len));
-		free(rt_key(rt), M_RTABLE, rt_key(rt)->sa_len);
-		KERNEL_UNLOCK();
+	free(rt->rt_gateway, M_RTABLE, ROUNDUP(rt->rt_gateway->sa_len));
+	free(rt_key(rt), M_RTABLE, rt_key(rt)->sa_len);
+	KERNEL_UNLOCK();
 
-		pool_put(&rtentry_pool, rt);
-	}
+	pool_put(&rtentry_pool, rt);
 }
 
 void
@@ -877,7 +871,7 @@ rtrequest(int req, struct rt_addrinfo *info, u_int8_t prio,
 			return (ENOBUFS);
 		}
 
-		rt->rt_refcnt = 1;
+		refcnt_init(&rt->rt_refcnt);
 		rt->rt_flags = info->rti_flags | RTF_UP;
 		rt->rt_priority = prio;	/* init routing priority */
 		LIST_INIT(&rt->rt_timer);
@@ -1879,8 +1873,8 @@ db_show_rtentry(struct rtentry *rt, void *w, unsigned int id)
 {
 	db_printf("rtentry=%p", rt);
 
-	db_printf(" flags=0x%x refcnt=%d use=%llu expire=%lld rtableid=%u\n",
-	    rt->rt_flags, rt->rt_refcnt, rt->rt_use, rt->rt_expire, id);
+	db_printf(" flags=0x%x refcnt=%u use=%llu expire=%lld rtableid=%u\n",
+	    rt->rt_flags, rt->rt_refcnt.r_refs, rt->rt_use, rt->rt_expire, id);
 
 	db_printf(" key="); db_print_sa(rt_key(rt));
 	db_printf(" plen=%d", rt_plen(rt));
diff --git a/sys/net/route.h b/sys/net/route.h
index 5692206e606..2178e401731 100644
--- a/sys/net/route.h
+++ b/sys/net/route.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: route.h,v 1.195 2022/06/27 21:26:46 claudio Exp $	*/
+/*	$OpenBSD: route.h,v 1.196 2022/06/28 10:01:13 bluhm Exp $	*/
 /*	$NetBSD: route.h,v 1.9 1996/02/13 22:00:49 christos Exp $	*/
 
 /*
@@ -121,7 +121,7 @@ struct rtentry {
 	struct rt_kmetrics rt_rmx;	/* metrics used by rx'ing protocols */
 	unsigned int	 rt_ifidx;	/* the answer: interface to use */
 	unsigned int	 rt_flags;	/* up/down?, host/net */
-	int		 rt_refcnt;	/* # held references */
+	struct refcnt	 rt_refcnt;	/* # held references */
 	int		 rt_plen;	/* prefix length */
 	uint16_t	 rt_labelid;	/* route label ID */
 	uint8_t		 rt_priority;	/* routing priority to use */
diff --git a/sys/net/rtable.c b/sys/net/rtable.c
index a28b3cfe13b..6a5f022bef2 100644
--- a/sys/net/rtable.c
+++ b/sys/net/rtable.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: rtable.c,v 1.78 2022/06/27 17:15:35 bluhm Exp $ */
+/*	$OpenBSD: rtable.c,v 1.79 2022/06/28 10:01:13 bluhm Exp $ */
 
 /*
  * Copyright (c) 2014-2016 Martin Pieuchot
@@ -681,7 +681,7 @@ rtable_delete(unsigned int rtableid, struct sockaddr *dst,
 		npaths++;
 
 	if (npaths > 1) {
-		KASSERT(rt->rt_refcnt >= 1);
+		KASSERT(refcnt_read(&rt->rt_refcnt) >= 1);
 		SRPL_REMOVE_LOCKED(&rt_rc, &an->an_rtlist, rt, rtentry,
 		    rt_next);
 
@@ -695,7 +695,7 @@ rtable_delete(unsigned int rtableid, struct sockaddr *dst,
 	if (art_delete(ar, an, addr, plen) == NULL)
 		panic("art_delete failed to find node %p", an);
 
-	KASSERT(rt->rt_refcnt >= 1);
+	KASSERT(refcnt_read(&rt->rt_refcnt) >= 1);
 	SRPL_REMOVE_LOCKED(&rt_rc, &an->an_rtlist, rt, rtentry, rt_next);
 	art_put(an);
 
diff --git a/sys/net/rtsock.c b/sys/net/rtsock.c
index 7b4e544fced..fde6ec78565 100644
--- a/sys/net/rtsock.c
+++ b/sys/net/rtsock.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: rtsock.c,v 1.333 2022/06/27 21:26:46 claudio Exp $	*/
+/*	$OpenBSD: rtsock.c,v 1.334 2022/06/28 10:01:13 bluhm Exp $	*/
 /*	$NetBSD: rtsock.c,v 1.18 1996/03/29 00:32:10 cgd Exp $	*/
 
 /*
@@ -2003,7 +2003,7 @@ sysctl_dumpentry(struct rtentry *rt, void *v, unsigned int id)
 		rtm->rtm_priority = rt->rt_priority & RTP_MASK;
 		rtm_getmetrics(rt, &rtm->rtm_rmx);
 		/* Do not account the routing table's reference. */
-		rtm->rtm_rmx.rmx_refcnt = rt->rt_refcnt - 1;
+		rtm->rtm_rmx.rmx_refcnt = refcnt_read(&rt->rt_refcnt) - 1;
 		rtm->rtm_index = rt->rt_ifidx;
 		rtm->rtm_addrs = info.rti_addrs;
 		rtm->rtm_tableid = id;