use a per-table rwlock to serialize ART updates and walks, rather than

taking the kernel lock.

ok mpi@ dlg@

diff --git a/sys/net/art.c b/sys/net/art.c
index 9183157..00699ab 100644 (file)
--- a/sys/net/art.c
+++ b/sys/net/art.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: art.c,v 1.22 2016/07/19 10:51:44 mpi Exp $ */
+/*     $OpenBSD: art.c,v 1.23 2016/08/30 07:42:57 jmatthew Exp $ */
 
 /*
  * Copyright (c) 2015 Martin Pieuchot
@@ -152,6 +152,7 @@ art_alloc(unsigned int rtableid, unsigned int alen, unsigned int off)
 
        ar->ar_off = off;
        ar->ar_rtableid = rtableid;
+       rw_init(&ar->ar_lock, "art");
 
        return (ar);
 }
@@ -378,7 +379,7 @@ art_insert(struct art_root *ar, struct art_node *an, uint8_t *addr, int plen)
        struct art_node         *node;
        int                      i, j;
 
-       KERNEL_ASSERT_LOCKED();
+       rw_assert_wrlock(&ar->ar_lock);
        KASSERT(plen >= 0 && plen <= ar->ar_alen);
 
        at = srp_get_locked(&ar->ar_root);
@@ -482,7 +483,7 @@ art_delete(struct art_root *ar, struct art_node *an, uint8_t *addr, int plen)
        struct art_node         *node;
        int                      i, j;
 
-       KERNEL_ASSERT_LOCKED();
+       rw_assert_wrlock(&ar->ar_lock);
        KASSERT(plen >= 0 && plen <= ar->ar_alen);
 
        at = srp_get_locked(&ar->ar_root);
@@ -613,7 +614,7 @@ art_walk(struct art_root *ar, int (*f)(struct art_node *, void *), void *arg)
        struct art_node         *node;
        int                      error = 0;
 
-       KERNEL_LOCK();
+       rw_enter_write(&ar->ar_lock);
        at = srp_get_locked(&ar->ar_root);
        if (at != NULL) {
                art_table_ref(ar, at);
@@ -631,7 +632,7 @@ art_walk(struct art_root *ar, int (*f)(struct art_node *, void *), void *arg)
 
                art_table_free(ar, at);
        }
-       KERNEL_UNLOCK();
+       rw_exit_write(&ar->ar_lock);
 
        return (error);
 }
@@ -708,9 +709,9 @@ art_walk_apply(struct art_root *ar,
 
        if ((an != NULL) && (an != next)) {
                /* this assumes an->an_dst is not used by f */
-               KERNEL_UNLOCK();
+               rw_exit_write(&ar->ar_lock);
                error = (*f)(an, arg);
-               KERNEL_LOCK();
+               rw_enter_write(&ar->ar_lock);
        }
 
        return (error);

diff --git a/sys/net/art.h b/sys/net/art.h
index d20b319..40b406d 100644 (file)
--- a/sys/net/art.h
+++ b/sys/net/art.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: art.h,v 1.14 2016/06/14 04:42:02 jmatthew Exp $ */
+/* $OpenBSD: art.h,v 1.15 2016/08/30 07:42:57 jmatthew Exp $ */
 
 /*
  * Copyright (c) 2015 Martin Pieuchot
@@ -19,6 +19,8 @@
 #ifndef _NET_ART_H_
 #define _NET_ART_H_
 
+#include <sys/rwlock.h>
+
 #define ART_MAXLVL     32      /* We currently use 32 levels for IPv6. */
 
 /*
@@ -26,6 +28,7 @@
  */
 struct art_root {
        struct srp               ar_root;       /* First table */
+       struct rwlock            ar_lock;       /* Serialise modifications */
        uint8_t                  ar_bits[ART_MAXLVL];   /* Per level stride */
        uint8_t                  ar_nlvl;       /* Number of levels */
        uint8_t                  ar_alen;       /* Address length in bits */

diff --git a/sys/net/rtable.c b/sys/net/rtable.c
index df50e81..9b84acb 100644 (file)
--- a/sys/net/rtable.c
+++ b/sys/net/rtable.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: rtable.c,v 1.50 2016/07/19 10:51:44 mpi Exp $ */
+/*     $OpenBSD: rtable.c,v 1.51 2016/08/30 07:42:57 jmatthew Exp $ */
 
 /*
  * Copyright (c) 2014-2015 Martin Pieuchot
@@ -515,6 +515,10 @@ static inline uint8_t      *satoaddr(struct art_root *, struct sockaddr *);
 void   rtentry_ref(void *, void *);
 void   rtentry_unref(void *, void *);
 
+#ifndef SMALL_KERNEL
+void   rtable_mpath_insert(struct art_node *, struct rtentry *);
+#endif
+
 struct srpl_rc rt_rc = SRPL_RC_INITIALIZER(rtentry_ref, rtentry_unref, NULL);
 
 void
@@ -679,8 +683,6 @@ rtable_insert(unsigned int rtableid, struct sockaddr *dst,
        unsigned int                     rt_flags;
        int                              error = 0;
 
-       KERNEL_ASSERT_LOCKED();
-
        ar = rtable_get(rtableid, dst->sa_family);
        if (ar == NULL)
                return (EAFNOSUPPORT);
@@ -691,6 +693,7 @@ rtable_insert(unsigned int rtableid, struct sockaddr *dst,
                return (EINVAL);
 
        rtref(rt); /* guarantee rtfree won't do anything during insert */
+       rw_enter_write(&ar->ar_lock);
 
 #ifndef SMALL_KERNEL
        /* Do not permit exactly the same dst/mask/gw pair. */
@@ -766,15 +769,14 @@ rtable_insert(unsigned int rtableid, struct sockaddr *dst,
                        }
                }
 
-               SRPL_INSERT_HEAD_LOCKED(&rt_rc, &an->an_rtlist, rt, rt_next);
-
                /* Put newly inserted entry at the right place. */
-               rtable_mpath_reprio(rtableid, dst, mask, rt->rt_priority, rt);
+               rtable_mpath_insert(an, rt);
 #else
                error = EEXIST;
 #endif /* SMALL_KERNEL */
        }
 leave:
+       rw_exit_write(&ar->ar_lock);
        rtfree(rt);
        return (error);
 }
@@ -792,6 +794,7 @@ rtable_delete(unsigned int rtableid, struct sockaddr *dst,
        struct rtentry                  *mrt;
        int                              npaths = 0;
 #endif /* SMALL_KERNEL */
+       int                              error = 0;
 
        ar = rtable_get(rtableid, dst->sa_family);
        if (ar == NULL)
@@ -800,15 +803,17 @@ rtable_delete(unsigned int rtableid, struct sockaddr *dst,
        addr = satoaddr(ar, dst);
        plen = rtable_satoplen(dst->sa_family, mask);
 
-       KERNEL_ASSERT_LOCKED();
-
+       rtref(rt); /* guarantee rtfree won't do anything under ar_lock */
+       rw_enter_write(&ar->ar_lock);
        an = art_lookup(ar, addr, plen, &sr);
        srp_leave(&sr); /* an can't go away while we have the lock */
 
        /* Make sure we've got a perfect match. */
        if (an == NULL || an->an_plen != plen ||
-           memcmp(an->an_dst, dst, dst->sa_len))
-               return (ESRCH);
+           memcmp(an->an_dst, dst, dst->sa_len)) {
+               error = ESRCH;
+               goto leave;
+       }
 
 #ifndef SMALL_KERNEL
        /*
@@ -827,18 +832,23 @@ rtable_delete(unsigned int rtableid, struct sockaddr *dst,
                an->an_dst = mrt->rt_dest;
                if (npaths == 2)
                        mrt->rt_flags &= ~RTF_MPATH;
-               return (0);
+
+               goto leave;
        }
 #endif /* SMALL_KERNEL */
 
        if (art_delete(ar, an, addr, plen) == NULL)
-               return (ESRCH);
+               panic("art_delete failed to find node %p", an);
 
        KASSERT(rt->rt_refcnt >= 1);
        SRPL_REMOVE_LOCKED(&rt_rc, &an->an_rtlist, rt, rtentry, rt_next);
-
        art_put(an);
-       return (0);
+
+leave:
+       rw_exit_write(&ar->ar_lock);
+       rtfree(rt);
+
+       return (error);
 }
 
 struct rtable_walk_cookie {
@@ -905,7 +915,7 @@ rtable_mpath_reprio(unsigned int rtableid, struct sockaddr *dst,
        struct srp_ref                   sr;
        uint8_t                         *addr;
        int                              plen;
-       struct rtentry                  *mrt, *prt = NULL;
+       int                              error = 0;
 
        ar = rtable_get(rtableid, dst->sa_family);
        if (ar == NULL)
@@ -914,19 +924,32 @@ rtable_mpath_reprio(unsigned int rtableid, struct sockaddr *dst,
        addr = satoaddr(ar, dst);
        plen = rtable_satoplen(dst->sa_family, mask);
 
-       KERNEL_ASSERT_LOCKED();
-
+       rw_enter_write(&ar->ar_lock);
        an = art_lookup(ar, addr, plen, &sr);
        srp_leave(&sr); /* an can't go away while we have the lock */
 
        /* Make sure we've got a perfect match. */
        if (an == NULL || an->an_plen != plen ||
            memcmp(an->an_dst, dst, dst->sa_len))
-               return (ESRCH);
+               error = ESRCH;
+       else {
+               rtref(rt); /* keep rt alive in between remove and insert */
+               SRPL_REMOVE_LOCKED(&rt_rc, &an->an_rtlist,
+                   rt, rtentry, rt_next);
+               rt->rt_priority = prio;
+               rtable_mpath_insert(an, rt);
+               rtfree(rt);
+       }
+       rw_exit_write(&ar->ar_lock);
 
-       rtref(rt); /* keep rt alive in between remove and add */
-       SRPL_REMOVE_LOCKED(&rt_rc, &an->an_rtlist, rt, rtentry, rt_next);
-       rt->rt_priority = prio;
+       return (error);
+}
+
+void
+rtable_mpath_insert(struct art_node *an, struct rtentry *rt)
+{
+       struct rtentry                  *mrt, *prt = NULL;
+       uint8_t                          prio = rt->rt_priority;
 
        if ((mrt = SRPL_FIRST_LOCKED(&an->an_rtlist)) != NULL) {
                /*
@@ -957,9 +980,6 @@ rtable_mpath_reprio(unsigned int rtableid, struct sockaddr *dst,
        } else {
                SRPL_INSERT_HEAD_LOCKED(&rt_rc, &an->an_rtlist, rt, rt_next);
        }
-       rtfree(rt);
-
-       return (0);
 }
 
 struct rtentry *