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- convert radix node head lock from mutex to rwlock

Browse Source 
- make radix node head lock not recursive
 - fix LOR in rtexpunge
 - fix LOR in rtredirect

Reviewed by:	sam
This commit is contained in:
Kip Macy 2008-12-07 21:15:43 +00:00
parent 5e5391084a
commit 3120b9d428
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=185747
10 changed files with 135 additions and 74 deletions
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2
sys/contrib/pf/net/pf_table.c
View File

@ -43,6 +43,8 @@ __FBSDID("$FreeBSD$");
#include <sys/socket.h>
#include <sys/mbuf.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/rwlock.h>
#ifdef __FreeBSD__
#include <sys/malloc.h>
#endif

2
sys/kern/subr_witness.c
View File

@ -505,7 +505,7 @@ static struct witness_order_list_entry order_lists[] = {
* Routing
*/
{ "so_rcv", &lock_class_mtx_sleep },
{ "radix node head", &lock_class_mtx_sleep },
{ "radix node head", &lock_class_rw },
{ "rtentry", &lock_class_mtx_sleep },
{ "ifaddr", &lock_class_mtx_sleep },
{ NULL, NULL },

5
sys/kern/vfs_export.c
View File

@ -46,6 +46,7 @@ __FBSDID("$FreeBSD$");
#include <sys/mbuf.h>
#include <sys/mount.h>
#include <sys/mutex.h>
#include <sys/rwlock.h>
#include <sys/refcount.h>
#include <sys/socket.h>
#include <sys/systm.h>
@ -425,10 +426,10 @@ vfs_export_lookup(struct mount *mp, struct sockaddr *nam)
saddr = nam;
rnh = nep->ne_rtable[saddr->sa_family];
if (rnh != NULL) {
RADIX_NODE_HEAD_LOCK(rnh);
RADIX_NODE_HEAD_RLOCK(rnh);
np = (struct netcred *)
(*rnh->rnh_matchaddr)(saddr, rnh);
RADIX_NODE_HEAD_UNLOCK(rnh);
RADIX_NODE_HEAD_RUNLOCK(rnh);
if (np && np->netc_rnodes->rn_flags & RNF_ROOT)
np = NULL;
}

1
sys/net/radix.c
View File

@ -38,6 +38,7 @@
#ifdef _KERNEL
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/rwlock.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/domain.h>

19
sys/net/radix.h
View File

@ -36,6 +36,7 @@
#ifdef _KERNEL
#include <sys/_lock.h>
#include <sys/_mutex.h>
#include <sys/_rwlock.h>
#endif
#ifdef MALLOC_DECLARE
@ -132,7 +133,7 @@ struct radix_node_head {
struct radix_node rnh_nodes[3]; /* empty tree for common case */
int rnh_multipath; /* multipath capable ? */
#ifdef _KERNEL
struct mtx rnh_mtx; /* locks entire radix tree */
struct rwlock rnh_lock; /* locks entire radix tree */
#endif
};
@ -146,11 +147,17 @@ struct radix_node_head {
#define Free(p) free((caddr_t)p, M_RTABLE);
#define RADIX_NODE_HEAD_LOCK_INIT(rnh) \
mtx_init(&(rnh)->rnh_mtx, "radix node head", NULL, MTX_DEF | MTX_RECURSE)
#define RADIX_NODE_HEAD_LOCK(rnh) mtx_lock(&(rnh)->rnh_mtx)
#define RADIX_NODE_HEAD_UNLOCK(rnh) mtx_unlock(&(rnh)->rnh_mtx)
#define RADIX_NODE_HEAD_DESTROY(rnh) mtx_destroy(&(rnh)->rnh_mtx)
#define RADIX_NODE_HEAD_LOCK_ASSERT(rnh) mtx_assert(&(rnh)->rnh_mtx, MA_OWNED)
rw_init_flags(&(rnh)->rnh_lock, "radix node head", 0)
#define RADIX_NODE_HEAD_LOCK(rnh) rw_wlock(&(rnh)->rnh_lock)
#define RADIX_NODE_HEAD_UNLOCK(rnh) rw_wunlock(&(rnh)->rnh_lock)
#define RADIX_NODE_HEAD_RLOCK(rnh) rw_rlock(&(rnh)->rnh_lock)
#define RADIX_NODE_HEAD_RUNLOCK(rnh) rw_runlock(&(rnh)->rnh_lock)
#define RADIX_NODE_HEAD_LOCK_TRY_UPGRADE(rnh) rw_try_upgrade(&(rnh)->rnh_lock)
#define RADIX_NODE_HEAD_DESTROY(rnh) rw_destroy(&(rnh)->rnh_lock)
#define RADIX_NODE_HEAD_LOCK_ASSERT(rnh) rw_assert(&(rnh)->rnh_lock, RA_LOCKED)
#define RADIX_NODE_HEAD_WLOCK_ASSERT(rnh) rw_assert(&(rnh)->rnh_lock, RA_WLOCKED)
#endif /* _KERNEL */
void rn_init(void);

168
sys/net/route.c
View File

@ -45,6 +45,7 @@
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/sysctl.h>
#include <sys/syslog.h>
#include <sys/sysproto.h>
#include <sys/proc.h>
#include <sys/domain.h>
@ -269,7 +270,8 @@ rtalloc1_fib(struct sockaddr *dst, int report, u_long ignflags,
struct rtentry *newrt;
struct rt_addrinfo info;
u_long nflags;
int err = 0, msgtype = RTM_MISS;
int needresolve = 0, err = 0, msgtype = RTM_MISS;
int needlock;
KASSERT((fibnum < rt_numfibs), ("rtalloc1_fib: bad fibnum"));
if (dst->sa_family != AF_INET) /* Only INET supports > 1 fib now */
@ -283,59 +285,92 @@ rtalloc1_fib(struct sockaddr *dst, int report, u_long ignflags,
V_rtstat.rts_unreach++;
goto miss2;
}
RADIX_NODE_HEAD_LOCK(rnh);
if ((rn = rnh->rnh_matchaddr(dst, rnh)) &&
(rn->rn_flags & RNF_ROOT) == 0) {
/*
* If we find it and it's not the root node, then
* get a reference on the rtentry associated.
*/
needlock = !(ignflags & RTF_RNH_LOCKED);
retry:
if (needlock)
RADIX_NODE_HEAD_RLOCK(rnh);
#ifdef INVARIANTS
else
RADIX_NODE_HEAD_LOCK_ASSERT(rnh);
#endif
rn = rnh->rnh_matchaddr(dst, rnh);
if (rn && ((rn->rn_flags & RNF_ROOT) == 0)) {
newrt = rt = RNTORT(rn);
nflags = rt->rt_flags & ~ignflags;
if (report && (nflags & RTF_CLONING)) {
/*
* We are apparently adding (report = 0 in delete).
* If it requires that it be cloned, do so.
* (This implies it wasn't a HOST route.)
*/
err = rtrequest_fib(RTM_RESOLVE, dst, NULL,
NULL, 0, &newrt, fibnum);
if (err) {
if (needlock && !RADIX_NODE_HEAD_LOCK_TRY_UPGRADE(rnh)) {
RADIX_NODE_HEAD_RUNLOCK(rnh);
RADIX_NODE_HEAD_LOCK(rnh);
/*
* If the cloning didn't succeed, maybe
* what we have will do. Return that.
* lookup again to make sure it wasn't changed
*/
newrt = rt; /* existing route */
RT_LOCK(newrt);
RT_ADDREF(newrt);
goto miss;
rn = rnh->rnh_matchaddr(dst, rnh);
if (!(rn && ((rn->rn_flags & RNF_ROOT) == 0))) {
RADIX_NODE_HEAD_UNLOCK(rnh);
needresolve = 0;
log(LOG_INFO, "retrying route lookup ...\n");
goto retry;
}
}
KASSERT(newrt, ("no route and no error"));
RT_LOCK(newrt);
if (newrt->rt_flags & RTF_XRESOLVE) {
/*
* If the new route specifies it be
* externally resolved, then go do that.
*/
msgtype = RTM_RESOLVE;
goto miss;
}
/* Inform listeners of the new route. */
bzero(&info, sizeof(info));
info.rti_info[RTAX_DST] = rt_key(newrt);
info.rti_info[RTAX_NETMASK] = rt_mask(newrt);
info.rti_info[RTAX_GATEWAY] = newrt->rt_gateway;
if (newrt->rt_ifp != NULL) {
info.rti_info[RTAX_IFP] =
newrt->rt_ifp->if_addr->ifa_addr;
info.rti_info[RTAX_IFA] = newrt->rt_ifa->ifa_addr;
}
rt_missmsg(RTM_ADD, &info, newrt->rt_flags, 0);
needresolve = 1;
} else {
RT_LOCK(newrt);
RT_ADDREF(newrt);
if (needlock)
RADIX_NODE_HEAD_RUNLOCK(rnh);
goto done;
}
RADIX_NODE_HEAD_UNLOCK(rnh);
}
/*
* if needresolve is set then we have the exclusive lock
* and we need to keep it held for the benefit of rtrequest_fib
*/
if (!needresolve && needlock)
RADIX_NODE_HEAD_RUNLOCK(rnh);
if (needresolve) {
RADIX_NODE_HEAD_WLOCK_ASSERT(rnh);
/*
* We are apparently adding (report = 0 in delete).
* If it requires that it be cloned, do so.
* (This implies it wasn't a HOST route.)
*/
err = rtrequest_fib(RTM_RESOLVE, dst, NULL,
NULL, RTF_RNH_LOCKED, &newrt, fibnum);
if (err) {
/*
* If the cloning didn't succeed, maybe
* what we have will do. Return that.
*/
newrt = rt; /* existing route */
RT_LOCK(newrt);
RT_ADDREF(newrt);
goto miss;
}
KASSERT(newrt, ("no route and no error"));
RT_LOCK(newrt);
if (newrt->rt_flags & RTF_XRESOLVE) {
/*
* If the new route specifies it be
* externally resolved, then go do that.
*/
msgtype = RTM_RESOLVE;
goto miss;
}
/* Inform listeners of the new route. */
bzero(&info, sizeof(info));
info.rti_info[RTAX_DST] = rt_key(newrt);
info.rti_info[RTAX_NETMASK] = rt_mask(newrt);
info.rti_info[RTAX_GATEWAY] = newrt->rt_gateway;
if (newrt->rt_ifp != NULL) {
info.rti_info[RTAX_IFP] =
newrt->rt_ifp->if_addr->ifa_addr;
info.rti_info[RTAX_IFA] = newrt->rt_ifa->ifa_addr;
}
rt_missmsg(RTM_ADD, &info, newrt->rt_flags, 0);
if (needlock)
RADIX_NODE_HEAD_UNLOCK(rnh);
} else {
/*
* Either we hit the root or couldn't find any match,
@ -344,7 +379,8 @@ rtalloc1_fib(struct sockaddr *dst, int report, u_long ignflags,
*/
V_rtstat.rts_unreach++;
miss:
RADIX_NODE_HEAD_UNLOCK(rnh);
if (needlock && needresolve)
RADIX_NODE_HEAD_UNLOCK(rnh);
miss2: if (report) {
/*
* If required, report the failure to the supervising
@ -356,6 +392,7 @@ rtalloc1_fib(struct sockaddr *dst, int report, u_long ignflags,
rt_missmsg(msgtype, &info, 0, err);
}
}
done:
if (newrt)
RT_LOCK_ASSERT(newrt);
return (newrt);
@ -475,6 +512,8 @@ rtredirect_fib(struct sockaddr *dst,
short *stat = NULL;
struct rt_addrinfo info;
struct ifaddr *ifa;
struct radix_node_head *rnh =
V_rt_tables[rt->rt_fibnum][dst->sa_family];
/* verify the gateway is directly reachable */
if ((ifa = ifa_ifwithnet(gateway)) == NULL) {
@ -524,14 +563,17 @@ rtredirect_fib(struct sockaddr *dst,
info.rti_info[RTAX_NETMASK] = netmask;
info.rti_ifa = ifa;
info.rti_flags = flags;
if (rt0 != NULL)
RT_UNLOCK(rt0); /* drop lock to avoid LOR with RNH */
error = rtrequest1_fib(RTM_ADD, &info, &rt, fibnum);
if (rt != NULL) {
RT_LOCK(rt);
EVENTHANDLER_INVOKE(route_redirect_event, rt0, rt, dst);
if (rt0 != NULL)
EVENTHANDLER_INVOKE(route_redirect_event, rt0, rt, dst);
flags = rt->rt_flags;
}
if (rt0)
RTFREE_LOCKED(rt0);
if (rt0 != NULL)
RTFREE(rt0);
stat = &V_rtstat.rts_dynamic;
} else {
@ -547,8 +589,12 @@ rtredirect_fib(struct sockaddr *dst,
/*
* add the key and gateway (in one malloc'd chunk).
*/
RT_UNLOCK(rt);
RADIX_NODE_HEAD_LOCK(rnh);
RT_LOCK(rt);
rt_setgate(rt, rt_key(rt), gateway);
gwrt = rtalloc1(gateway, 1, 0);
gwrt = rtalloc1(gateway, 1, RTF_RNH_LOCKED);
RADIX_NODE_HEAD_UNLOCK(rnh);
EVENTHANDLER_INVOKE(route_redirect_event, rt, gwrt, dst);
RTFREE_LOCKED(gwrt);
}
@ -782,7 +828,9 @@ rtexpunge(struct rtentry *rt)
struct ifaddr *ifa;
int error = 0;
rnh = V_rt_tables[rt->rt_fibnum][rt_key(rt)->sa_family];
RT_LOCK_ASSERT(rt);
RADIX_NODE_HEAD_LOCK_ASSERT(rnh);
#if 0
/*
* We cannot assume anything about the reference count
@ -798,8 +846,6 @@ rtexpunge(struct rtentry *rt)
if (rnh == NULL)
return (EAFNOSUPPORT);
RADIX_NODE_HEAD_LOCK(rnh);
/*
* Remove the item from the tree; it should be there,
* but when callers invoke us blindly it may not (sigh).
@ -854,7 +900,6 @@ rtexpunge(struct rtentry *rt)
*/
V_rttrash++;
bad:
RADIX_NODE_HEAD_UNLOCK(rnh);
return (error);
}
@ -869,7 +914,7 @@ rtrequest1_fib(int req, struct rt_addrinfo *info, struct rtentry **ret_nrt,
u_int fibnum)
{
INIT_VNET_NET(curvnet);
int error = 0;
int error = 0, needlock = 0;
register struct rtentry *rt;
register struct radix_node *rn;
register struct radix_node_head *rnh;
@ -886,7 +931,10 @@ rtrequest1_fib(int req, struct rt_addrinfo *info, struct rtentry **ret_nrt,
rnh = V_rt_tables[fibnum][dst->sa_family];
if (rnh == NULL)
return (EAFNOSUPPORT);
RADIX_NODE_HEAD_LOCK(rnh);
needlock = ((flags & RTF_RNH_LOCKED) == 0);
flags &= ~RTF_RNH_LOCKED;
if (needlock)
RADIX_NODE_HEAD_LOCK(rnh);
/*
* If we are adding a host route then we don't want to put
* a netmask in the tree, nor do we want to clone it.
@ -1200,7 +1248,8 @@ rtrequest1_fib(int req, struct rt_addrinfo *info, struct rtentry **ret_nrt,
error = EOPNOTSUPP;
}
bad:
RADIX_NODE_HEAD_UNLOCK(rnh);
if (needlock)
RADIX_NODE_HEAD_UNLOCK(rnh);
return (error);
#undef senderr
}
@ -1307,7 +1356,8 @@ rt_setgate(struct rtentry *rt, struct sockaddr *dst, struct sockaddr *gate)
again:
RT_LOCK_ASSERT(rt);
RADIX_NODE_HEAD_LOCK_ASSERT(rnh);
/*
* A host route with the destination equal to the gateway
* will interfere with keeping LLINFO in the routing
@ -1333,7 +1383,7 @@ rt_setgate(struct rtentry *rt, struct sockaddr *dst, struct sockaddr *gate)
struct rtentry *gwrt;
RT_UNLOCK(rt); /* XXX workaround LOR */
gwrt = rtalloc1_fib(gate, 1, 0, rt->rt_fibnum);
gwrt = rtalloc1_fib(gate, 1, RTF_RNH_LOCKED, rt->rt_fibnum);
if (gwrt == rt) {
RT_REMREF(rt);
return (EADDRINUSE); /* failure */
@ -1404,12 +1454,8 @@ rt_setgate(struct rtentry *rt, struct sockaddr *dst, struct sockaddr *gate)
arg.rnh = rnh;
arg.rt0 = rt;
RT_UNLOCK(rt); /* XXX workaround LOR */
RADIX_NODE_HEAD_LOCK(rnh);
RT_LOCK(rt);
rnh->rnh_walktree_from(rnh, rt_key(rt), rt_mask(rt),
rt_fixchange, &arg);
RADIX_NODE_HEAD_UNLOCK(rnh);
}
return 0;

1
sys/net/route.h
View File

@ -196,6 +196,7 @@ struct ortentry {
#define RTF_BROADCAST 0x400000 /* route represents a bcast address */
#define RTF_MULTICAST 0x800000 /* route represents a mcast address */
/* 0x1000000 and up unassigned */
#define RTF_RNH_LOCKED 0x40000000 /* radix node head locked by caller */
/* Mask of RTF flags that are allowed to be modified by RTM_CHANGE. */
#define RTF_FMASK \

9
sys/net/rtsock.c
View File

@ -43,6 +43,7 @@
#include <sys/priv.h>
#include <sys/proc.h>
#include <sys/protosw.h>
#include <sys/rwlock.h>
#include <sys/signalvar.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
@ -554,11 +555,11 @@ route_output(struct mbuf *m, struct socket *so)
rnh = V_rt_tables[so->so_fibnum][info.rti_info[RTAX_DST]->sa_family];
if (rnh == NULL)
senderr(EAFNOSUPPORT);
RADIX_NODE_HEAD_LOCK(rnh);
RADIX_NODE_HEAD_RLOCK(rnh);
rt = (struct rtentry *) rnh->rnh_lookup(info.rti_info[RTAX_DST],
info.rti_info[RTAX_NETMASK], rnh);
if (rt == NULL) { /* XXX looks bogus */
RADIX_NODE_HEAD_UNLOCK(rnh);
RADIX_NODE_HEAD_RUNLOCK(rnh);
senderr(ESRCH);
}
#ifdef RADIX_MPATH
@ -574,14 +575,14 @@ route_output(struct mbuf *m, struct socket *so)
(rtm->rtm_type != RTM_GET || info.rti_info[RTAX_GATEWAY])) {
rt = rt_mpath_matchgate(rt, info.rti_info[RTAX_GATEWAY]);
if (!rt) {
RADIX_NODE_HEAD_UNLOCK(rnh);
RADIX_NODE_HEAD_RUNLOCK(rnh);
senderr(ESRCH);
}
}
#endif
RT_LOCK(rt);
RT_ADDREF(rt);
RADIX_NODE_HEAD_UNLOCK(rnh);
RADIX_NODE_HEAD_RUNLOCK(rnh);
/*
* Fix for PR: 82974

1
sys/netinet6/in6_rmx.c
View File

@ -83,6 +83,7 @@ __FBSDID("$FreeBSD$");
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/mbuf.h>
#include <sys/rwlock.h>
#include <sys/syslog.h>
#include <sys/callout.h>
#include <sys/vimage.h>

1
sys/netinet6/nd6_rtr.c
View File

@ -44,6 +44,7 @@ __FBSDID("$FreeBSD$");
#include <sys/time.h>
#include <sys/kernel.h>
#include <sys/errno.h>
#include <sys/rwlock.h>
#include <sys/syslog.h>
#include <sys/queue.h>
#include <sys/vimage.h>