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-rw-r--r--sys/net/bridgestp.c4
-rw-r--r--sys/net/if.c94
-rw-r--r--sys/net/if_llatbl.c8
-rw-r--r--sys/net/if_var.h42
-rw-r--r--sys/net/if_vlan.c4
5 files changed, 100 insertions, 52 deletions
diff --git a/sys/net/bridgestp.c b/sys/net/bridgestp.c
index 3e65113c2d56..2993838ac683 100644
--- a/sys/net/bridgestp.c
+++ b/sys/net/bridgestp.c
@@ -2019,7 +2019,7 @@ bstp_reinit(struct bstp_state *bs)
* not need to be part of the bridge, it just needs to be a unique
* value.
*/
- IFNET_RLOCK();
+ IFNET_RLOCK_NOSLEEP();
TAILQ_FOREACH(ifp, &V_ifnet, if_link) {
if (ifp->if_type != IFT_ETHER)
continue;
@@ -2036,7 +2036,7 @@ bstp_reinit(struct bstp_state *bs)
continue;
}
}
- IFNET_RUNLOCK();
+ IFNET_RUNLOCK_NOSLEEP();
if (LIST_EMPTY(&bs->bs_bplist) || mif == NULL) {
/* Set the bridge and root id (lower bits) to zero */
diff --git a/sys/net/if.c b/sys/net/if.c
index 5d108981cdde..fe497d69de2d 100644
--- a/sys/net/if.c
+++ b/sys/net/if.c
@@ -154,14 +154,26 @@ VNET_DEFINE(struct ifgrouphead, ifg_head);
VNET_DEFINE(int, if_index);
static VNET_DEFINE(int, if_indexlim) = 8;
-/* Table of ifnet by index. Locked with ifnet_lock. */
+/* Table of ifnet by index. */
static VNET_DEFINE(struct ifindex_entry *, ifindex_table);
#define V_if_indexlim VNET(if_indexlim)
#define V_ifindex_table VNET(ifindex_table)
int ifqmaxlen = IFQ_MAXLEN;
-struct rwlock ifnet_lock;
+
+/*
+ * The global network interface list (V_ifnet) and related state (such as
+ * if_index, if_indexlim, and ifindex_table) are protected by an sxlock and
+ * an rwlock. Either may be acquired shared to stablize the list, but both
+ * must be acquired writable to modify the list. This model allows us to
+ * both stablize the interface list during interrupt thread processing, but
+ * also to stablize it over long-running ioctls, without introducing priority
+ * inversions and deadlocks.
+ */
+struct rwlock ifnet_rwlock;
+struct sx ifnet_sxlock;
+
static if_com_alloc_t *if_com_alloc[256];
static if_com_free_t *if_com_free[256];
@@ -188,9 +200,9 @@ ifnet_byindex(u_short idx)
{
struct ifnet *ifp;
- IFNET_RLOCK();
+ IFNET_RLOCK_NOSLEEP();
ifp = ifnet_byindex_locked(idx);
- IFNET_RUNLOCK();
+ IFNET_RUNLOCK_NOSLEEP();
return (ifp);
}
@@ -199,19 +211,19 @@ ifnet_byindex_ref(u_short idx)
{
struct ifnet *ifp;
- IFNET_RLOCK();
+ IFNET_RLOCK_NOSLEEP();
ifp = ifnet_byindex_locked(idx);
if (ifp == NULL || (ifp->if_flags & IFF_DYING)) {
- IFNET_RUNLOCK();
+ IFNET_RUNLOCK_NOSLEEP();
return (NULL);
}
if_ref(ifp);
- IFNET_RUNLOCK();
+ IFNET_RUNLOCK_NOSLEEP();
return (ifp);
}
static void
-ifnet_setbyindex(u_short idx, struct ifnet *ifp)
+ifnet_setbyindex_locked(u_short idx, struct ifnet *ifp)
{
IFNET_WLOCK_ASSERT();
@@ -219,16 +231,25 @@ ifnet_setbyindex(u_short idx, struct ifnet *ifp)
V_ifindex_table[idx].ife_ifnet = ifp;
}
+static void
+ifnet_setbyindex(u_short idx, struct ifnet *ifp)
+{
+
+ IFNET_WLOCK();
+ ifnet_setbyindex_locked(idx, ifp);
+ IFNET_WUNLOCK();
+}
+
struct ifaddr *
ifaddr_byindex(u_short idx)
{
struct ifaddr *ifa;
- IFNET_RLOCK();
+ IFNET_RLOCK_NOSLEEP();
ifa = ifnet_byindex_locked(idx)->if_addr;
if (ifa != NULL)
ifa_ref(ifa);
- IFNET_RUNLOCK();
+ IFNET_RUNLOCK_NOSLEEP();
return (ifa);
}
@@ -361,9 +382,7 @@ if_alloc(u_char type)
ifq_init(&ifp->if_snd, ifp);
refcount_init(&ifp->if_refcount, 1); /* Index reference. */
- IFNET_WLOCK();
ifnet_setbyindex(ifp->if_index, ifp);
- IFNET_WUNLOCK();
return (ifp);
}
@@ -383,7 +402,7 @@ if_free_internal(struct ifnet *ifp)
KASSERT(ifp == ifnet_byindex_locked(ifp->if_index),
("%s: freeing unallocated ifnet", ifp->if_xname));
- ifnet_setbyindex(ifp->if_index, NULL);
+ ifnet_setbyindex_locked(ifp->if_index, NULL);
while (V_if_index > 0 && ifnet_byindex_locked(V_if_index) == NULL)
V_if_index--;
IFNET_WUNLOCK();
@@ -855,11 +874,14 @@ if_vmove(struct ifnet *ifp, struct vnet *new_vnet)
if_detach_internal(ifp, 1);
/*
- * Unlink the ifnet from ifindex_table[] in current vnet,
- * and shrink the if_index for that vnet if possible.
+ * Unlink the ifnet from ifindex_table[] in current vnet, and shrink
+ * the if_index for that vnet if possible.
+ *
+ * NOTE: IFNET_WLOCK/IFNET_WUNLOCK() are assumed to be unvirtualized,
+ * or we'd lock on one vnet and unlock on another.
*/
IFNET_WLOCK();
- ifnet_setbyindex(ifp->if_index, NULL);
+ ifnet_setbyindex_locked(ifp->if_index, NULL);
while (V_if_index > 0 && ifnet_byindex_locked(V_if_index) == NULL)
V_if_index--;
IFNET_WUNLOCK();
@@ -886,7 +908,7 @@ if_vmove(struct ifnet *ifp, struct vnet *new_vnet)
V_if_index = ifp->if_index;
if (V_if_index >= V_if_indexlim)
if_grow();
- ifnet_setbyindex(ifp->if_index, ifp);
+ ifnet_setbyindex_locked(ifp->if_index, ifp);
IFNET_WUNLOCK();
if_attach_internal(ifp, 1);
@@ -1368,7 +1390,7 @@ ifa_ifwithaddr_internal(struct sockaddr *addr, int getref)
struct ifnet *ifp;
struct ifaddr *ifa;
- IFNET_RLOCK();
+ IFNET_RLOCK_NOSLEEP();
TAILQ_FOREACH(ifp, &V_ifnet, if_link) {
IF_ADDR_LOCK(ifp);
TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
@@ -1395,7 +1417,7 @@ ifa_ifwithaddr_internal(struct sockaddr *addr, int getref)
}
ifa = NULL;
done:
- IFNET_RUNLOCK();
+ IFNET_RUNLOCK_NOSLEEP();
return (ifa);
}
@@ -1423,7 +1445,7 @@ ifa_ifwithbroadaddr(struct sockaddr *addr)
struct ifnet *ifp;
struct ifaddr *ifa;
- IFNET_RLOCK();
+ IFNET_RLOCK_NOSLEEP();
TAILQ_FOREACH(ifp, &V_ifnet, if_link) {
IF_ADDR_LOCK(ifp);
TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
@@ -1442,7 +1464,7 @@ ifa_ifwithbroadaddr(struct sockaddr *addr)
}
ifa = NULL;
done:
- IFNET_RUNLOCK();
+ IFNET_RUNLOCK_NOSLEEP();
return (ifa);
}
@@ -1456,7 +1478,7 @@ ifa_ifwithdstaddr(struct sockaddr *addr)
struct ifnet *ifp;
struct ifaddr *ifa;
- IFNET_RLOCK();
+ IFNET_RLOCK_NOSLEEP();
TAILQ_FOREACH(ifp, &V_ifnet, if_link) {
if ((ifp->if_flags & IFF_POINTOPOINT) == 0)
continue;
@@ -1475,7 +1497,7 @@ ifa_ifwithdstaddr(struct sockaddr *addr)
}
ifa = NULL;
done:
- IFNET_RUNLOCK();
+ IFNET_RUNLOCK_NOSLEEP();
return (ifa);
}
@@ -1508,7 +1530,7 @@ ifa_ifwithnet(struct sockaddr *addr)
* we find one, as we release the IF_ADDR_LOCK() that kept it stable
* when we move onto the next interface.
*/
- IFNET_RLOCK();
+ IFNET_RLOCK_NOSLEEP();
TAILQ_FOREACH(ifp, &V_ifnet, if_link) {
IF_ADDR_LOCK(ifp);
TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
@@ -1584,7 +1606,7 @@ next: continue;
ifa = ifa_maybe;
ifa_maybe = NULL;
done:
- IFNET_RUNLOCK();
+ IFNET_RUNLOCK_NOSLEEP();
if (ifa_maybe != NULL)
ifa_free(ifa_maybe);
return (ifa);
@@ -1863,7 +1885,7 @@ if_slowtimo(void *arg)
int s = splimp();
VNET_LIST_RLOCK_NOSLEEP();
- IFNET_RLOCK();
+ IFNET_RLOCK_NOSLEEP();
VNET_FOREACH(vnet_iter) {
CURVNET_SET(vnet_iter);
TAILQ_FOREACH(ifp, &V_ifnet, if_link) {
@@ -1874,7 +1896,7 @@ if_slowtimo(void *arg)
}
CURVNET_RESTORE();
}
- IFNET_RUNLOCK();
+ IFNET_RUNLOCK_NOSLEEP();
VNET_LIST_RUNLOCK_NOSLEEP();
splx(s);
timeout(if_slowtimo, (void *)0, hz / IFNET_SLOWHZ);
@@ -1889,7 +1911,7 @@ ifunit_ref(const char *name)
{
struct ifnet *ifp;
- IFNET_RLOCK();
+ IFNET_RLOCK_NOSLEEP();
TAILQ_FOREACH(ifp, &V_ifnet, if_link) {
if (strncmp(name, ifp->if_xname, IFNAMSIZ) == 0 &&
!(ifp->if_flags & IFF_DYING))
@@ -1897,7 +1919,7 @@ ifunit_ref(const char *name)
}
if (ifp != NULL)
if_ref(ifp);
- IFNET_RUNLOCK();
+ IFNET_RUNLOCK_NOSLEEP();
return (ifp);
}
@@ -1906,12 +1928,12 @@ ifunit(const char *name)
{
struct ifnet *ifp;
- IFNET_RLOCK();
+ IFNET_RLOCK_NOSLEEP();
TAILQ_FOREACH(ifp, &V_ifnet, if_link) {
if (strncmp(name, ifp->if_xname, IFNAMSIZ) == 0)
break;
}
- IFNET_RUNLOCK();
+ IFNET_RUNLOCK_NOSLEEP();
return (ifp);
}
@@ -2521,7 +2543,7 @@ again:
max_len = 0;
valid_len = 0;
- IFNET_RLOCK(); /* could sleep XXX */
+ IFNET_RLOCK();
TAILQ_FOREACH(ifp, &V_ifnet, if_link) {
int addrs;
@@ -2846,13 +2868,13 @@ if_delmulti(struct ifnet *ifp, struct sockaddr *sa)
#ifdef INVARIANTS
struct ifnet *oifp;
- IFNET_RLOCK();
+ IFNET_RLOCK_NOSLEEP();
TAILQ_FOREACH(oifp, &V_ifnet, if_link)
if (ifp == oifp)
break;
if (ifp != oifp)
ifp = NULL;
- IFNET_RUNLOCK();
+ IFNET_RUNLOCK_NOSLEEP();
KASSERT(ifp != NULL, ("%s: ifnet went away", __func__));
#endif
@@ -2895,7 +2917,7 @@ if_delmulti_ifma(struct ifmultiaddr *ifma)
} else {
struct ifnet *oifp;
- IFNET_RLOCK();
+ IFNET_RLOCK_NOSLEEP();
TAILQ_FOREACH(oifp, &V_ifnet, if_link)
if (ifp == oifp)
break;
@@ -2903,7 +2925,7 @@ if_delmulti_ifma(struct ifmultiaddr *ifma)
printf("%s: ifnet %p disappeared\n", __func__, ifp);
ifp = NULL;
}
- IFNET_RUNLOCK();
+ IFNET_RUNLOCK_NOSLEEP();
}
#endif
/*
diff --git a/sys/net/if_llatbl.c b/sys/net/if_llatbl.c
index a1b574f9f371..a3617f50d652 100644
--- a/sys/net/if_llatbl.c
+++ b/sys/net/if_llatbl.c
@@ -200,14 +200,14 @@ lltable_prefix_free(int af, struct sockaddr *prefix, struct sockaddr *mask)
{
struct lltable *llt;
- IFNET_RLOCK();
+ IFNET_RLOCK_NOSLEEP();
SLIST_FOREACH(llt, &lltables, llt_link) {
if (llt->llt_af != af)
continue;
llt->llt_prefix_free(llt, prefix, mask);
}
- IFNET_RUNLOCK();
+ IFNET_RUNLOCK_NOSLEEP();
}
@@ -300,13 +300,13 @@ lla_rt_output(struct rt_msghdr *rtm, struct rt_addrinfo *info)
}
/* XXX linked list may be too expensive */
- IFNET_RLOCK();
+ IFNET_RLOCK_NOSLEEP();
SLIST_FOREACH(llt, &lltables, llt_link) {
if (llt->llt_af == dst->sa_family &&
llt->llt_ifp == ifp)
break;
}
- IFNET_RUNLOCK();
+ IFNET_RUNLOCK_NOSLEEP();
KASSERT(llt != NULL, ("Yep, ugly hacks are bad\n"));
if (flags && LLE_CREATE)
diff --git a/sys/net/if_var.h b/sys/net/if_var.h
index aa83161cce3c..0bfd9f19a8a4 100644
--- a/sys/net/if_var.h
+++ b/sys/net/if_var.h
@@ -85,6 +85,7 @@ struct vnet;
#include <sys/lock.h> /* XXX */
#include <sys/mutex.h> /* XXX */
#include <sys/rwlock.h> /* XXX */
+#include <sys/sx.h> /* XXX */
#include <sys/event.h> /* XXX */
#include <sys/_task.h>
@@ -754,14 +755,39 @@ struct ifmultiaddr {
#ifdef _KERNEL
-extern struct rwlock ifnet_lock;
-#define IFNET_LOCK_INIT() \
- rw_init_flags(&ifnet_lock, "ifnet", RW_RECURSE)
-#define IFNET_WLOCK() rw_wlock(&ifnet_lock)
-#define IFNET_WUNLOCK() rw_wunlock(&ifnet_lock)
-#define IFNET_WLOCK_ASSERT() rw_assert(&ifnet_lock, RA_LOCKED)
-#define IFNET_RLOCK() rw_rlock(&ifnet_lock)
-#define IFNET_RUNLOCK() rw_runlock(&ifnet_lock)
+extern struct rwlock ifnet_rwlock;
+extern struct sx ifnet_sxlock;
+
+#define IFNET_LOCK_INIT() do { \
+ rw_init_flags(&ifnet_rwlock, "ifnet_rw", RW_RECURSE); \
+ sx_init_flags(&ifnet_sxlock, "ifnet_sx", SX_RECURSE); \
+} while(0)
+
+#define IFNET_WLOCK() do { \
+ sx_xlock(&ifnet_sxlock); \
+ rw_wlock(&ifnet_rwlock); \
+} while (0)
+
+#define IFNET_WUNLOCK() do { \
+ rw_wunlock(&ifnet_rwlock); \
+ sx_xunlock(&ifnet_sxlock); \
+} while (0)
+
+/*
+ * To assert the ifnet lock, you must know not only whether it's for read or
+ * write, but also whether it was acquired with sleep support or not.
+ */
+#define IFNET_RLOCK_ASSERT() sx_assert(&ifnet_sxlock, SA_SLOCKED)
+#define IFNET_RLOCK_NOSLEEP_ASSERT() rw_assert(&ifnet_rwlock, RA_RLOCKED)
+#define IFNET_WLOCK_ASSERT() do { \
+ sx_assert(&ifnet_sxlock, SA_XLOCKED); \
+ rw_assert(&ifnet_rwlock, RA_WLOCKED); \
+} while (0)
+
+#define IFNET_RLOCK() sx_slock(&ifnet_sxlock)
+#define IFNET_RLOCK_NOSLEEP() rw_rlock(&ifnet_rwlock)
+#define IFNET_RUNLOCK() sx_sunlock(&ifnet_sxlock)
+#define IFNET_RUNLOCK_NOSLEEP() rw_runlock(&ifnet_rwlock)
/*
* Look up an ifnet given its index; the _ref variant also acquires a
diff --git a/sys/net/if_vlan.c b/sys/net/if_vlan.c
index 04c2c0dc6448..126d83ffb35d 100644
--- a/sys/net/if_vlan.c
+++ b/sys/net/if_vlan.c
@@ -580,7 +580,7 @@ vlan_clone_match_ethertag(struct if_clone *ifc, const char *name, int *tag)
int t = 0;
/* Check for <etherif>.<vlan> style interface names. */
- IFNET_RLOCK();
+ IFNET_RLOCK_NOSLEEP();
TAILQ_FOREACH(ifp, &V_ifnet, if_link) {
if (ifp->if_type != IFT_ETHER)
continue;
@@ -598,7 +598,7 @@ vlan_clone_match_ethertag(struct if_clone *ifc, const char *name, int *tag)
*tag = t;
break;
}
- IFNET_RUNLOCK();
+ IFNET_RUNLOCK_NOSLEEP();
return (ifp);
}
generated by cgit v1.2.3 (git 2.25.1) at 2024-10-19 13:28:20 +0000