Improve carp(4) locking:
- Use the carp_sx to serialize not only CARP ioctls, but also carp_attach() and carp_detach(). - Use cif_mtx to lock only access to those the linked list. - These locking changes allow us to do some memory allocations with M_WAITOK and also properly call callout_drain() in carp_destroy(). - In carp_attach() assert that ifaddr isn't attached. We always come here with a pristine address from in[6]_control(). Reviewed by: oleg Sponsored by: Nginx, Inc.
This commit is contained in:
Gleb Smirnoff
parent
270538b2b6
commit
9c2cd1aa84
Notes:
svn2git
2020-12-20 02:59:44 +00:00
svn path=/head/; revision=281839
@ -256,7 +256,7 @@ SYSCTL_VNET_PCPUSTAT(_net_inet_carp, OID_AUTO, stats, struct carpstats,
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#define CIF_LOCK(cif) mtx_lock(&(cif)->cif_mtx)
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#define CIF_UNLOCK(cif) mtx_unlock(&(cif)->cif_mtx)
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#define CIF_FREE(cif) do { \
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CIF_LOCK_ASSERT(cif); \
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CIF_LOCK(cif); \
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if (TAILQ_EMPTY(&(cif)->cif_vrs)) \
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carp_free_if(cif); \
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else \
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@ -296,7 +296,6 @@ SYSCTL_VNET_PCPUSTAT(_net_inet_carp, OID_AUTO, stats, struct carpstats,
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static void carp_input_c(struct mbuf *, struct carp_header *, sa_family_t);
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static struct carp_softc
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*carp_alloc(struct ifnet *);
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static void carp_detach_locked(struct ifaddr *);
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static void carp_destroy(struct carp_softc *);
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static struct carp_if
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*carp_alloc_if(struct ifnet *);
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@ -1250,8 +1249,6 @@ carp_multicast_setup(struct carp_if *cif, sa_family_t sa)
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struct ifnet *ifp = cif->cif_ifp;
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int error = 0;
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CIF_LOCK_ASSERT(cif);
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switch (sa) {
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#ifdef INET
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case AF_INET:
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@ -1264,9 +1261,7 @@ carp_multicast_setup(struct carp_if *cif, sa_family_t sa)
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imo->imo_membership = (struct in_multi **)malloc(
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(sizeof(struct in_multi *) * IP_MIN_MEMBERSHIPS), M_CARP,
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M_NOWAIT);
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if (imo->imo_membership == NULL)
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return (ENOMEM);
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M_WAITOK);
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imo->imo_mfilters = NULL;
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imo->imo_max_memberships = IP_MIN_MEMBERSHIPS;
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imo->imo_multicast_vif = -1;
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@ -1296,9 +1291,7 @@ carp_multicast_setup(struct carp_if *cif, sa_family_t sa)
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im6o->im6o_membership = (struct in6_multi **)malloc(
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(sizeof(struct in6_multi *) * IPV6_MIN_MEMBERSHIPS), M_CARP,
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M_ZERO | M_NOWAIT);
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if (im6o->im6o_membership == NULL)
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return (ENOMEM);
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M_ZERO | M_WAITOK);
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im6o->im6o_mfilters = NULL;
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im6o->im6o_max_memberships = IPV6_MIN_MEMBERSHIPS;
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im6o->im6o_multicast_hlim = CARP_DFLTTL;
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@ -1355,7 +1348,8 @@ static void
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carp_multicast_cleanup(struct carp_if *cif, sa_family_t sa)
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{
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CIF_LOCK_ASSERT(cif);
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sx_assert(&carp_sx, SA_XLOCKED);
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switch (sa) {
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#ifdef INET
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case AF_INET:
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@ -1504,22 +1498,18 @@ carp_alloc(struct ifnet *ifp)
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return (sc);
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}
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static int
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static void
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carp_grow_ifas(struct carp_softc *sc)
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{
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struct ifaddr **new;
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CARP_LOCK_ASSERT(sc);
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new = malloc(sc->sc_ifasiz * 2, M_CARP, M_NOWAIT|M_ZERO);
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if (new == NULL)
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return (ENOMEM);
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new = malloc(sc->sc_ifasiz * 2, M_CARP, M_WAITOK | M_ZERO);
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CARP_LOCK(sc);
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bcopy(sc->sc_ifas, new, sc->sc_ifasiz);
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free(sc->sc_ifas, M_CARP);
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sc->sc_ifas = new;
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sc->sc_ifasiz *= 2;
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return (0);
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CARP_UNLOCK(sc);
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}
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static void
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@ -1528,17 +1518,20 @@ carp_destroy(struct carp_softc *sc)
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struct ifnet *ifp = sc->sc_carpdev;
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struct carp_if *cif = ifp->if_carp;
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CIF_LOCK_ASSERT(cif);
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sx_assert(&carp_sx, SA_XLOCKED);
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if (sc->sc_suppress)
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carp_demote_adj(-V_carp_ifdown_adj, "vhid removed");
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CARP_UNLOCK(sc);
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CIF_LOCK(cif);
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TAILQ_REMOVE(&cif->cif_vrs, sc, sc_list);
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CIF_UNLOCK(cif);
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mtx_lock(&carp_mtx);
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LIST_REMOVE(sc, sc_next);
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mtx_unlock(&carp_mtx);
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CARP_LOCK(sc);
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if (sc->sc_suppress)
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carp_demote_adj(-V_carp_ifdown_adj, "vhid removed");
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callout_drain(&sc->sc_ad_tmo);
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#ifdef INET
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callout_drain(&sc->sc_md_tmo);
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@ -1807,8 +1800,7 @@ carp_attach(struct ifaddr *ifa, int vhid)
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struct carp_softc *sc;
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int index, error;
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if (ifp->if_carp == NULL)
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return (ENOPROTOOPT);
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KASSERT(ifa->ifa_carp == NULL, ("%s: ifa %p attached", __func__, ifa));
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switch (ifa->ifa_addr->sa_family) {
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#ifdef INET
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@ -1822,40 +1814,32 @@ carp_attach(struct ifaddr *ifa, int vhid)
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return (EPROTOTYPE);
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}
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sx_xlock(&carp_sx);
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if (ifp->if_carp == NULL) {
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sx_xunlock(&carp_sx);
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return (ENOPROTOOPT);
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}
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CIF_LOCK(cif);
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IFNET_FOREACH_CARP(ifp, sc)
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if (sc->sc_vhid == vhid)
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break;
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CIF_UNLOCK(cif);
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if (sc == NULL) {
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CIF_UNLOCK(cif);
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sx_xunlock(&carp_sx);
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return (ENOENT);
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}
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if (ifa->ifa_carp) {
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if (ifa->ifa_carp->sc_vhid != vhid)
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carp_detach_locked(ifa);
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else {
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CIF_UNLOCK(cif);
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return (0);
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}
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}
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error = carp_multicast_setup(cif, ifa->ifa_addr->sa_family);
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if (error) {
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CIF_FREE(cif);
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sx_xunlock(&carp_sx);
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return (error);
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}
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CARP_LOCK(sc);
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index = sc->sc_naddrs + sc->sc_naddrs6 + 1;
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if (index > sc->sc_ifasiz / sizeof(struct ifaddr *))
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if ((error = carp_grow_ifas(sc)) != 0) {
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carp_multicast_cleanup(cif,
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ifa->ifa_addr->sa_family);
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CARP_UNLOCK(sc);
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CIF_FREE(cif);
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return (error);
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}
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carp_grow_ifas(sc);
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switch (ifa->ifa_addr->sa_family) {
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#ifdef INET
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@ -1873,31 +1857,21 @@ carp_attach(struct ifaddr *ifa, int vhid)
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}
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ifa_ref(ifa);
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CARP_LOCK(sc);
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sc->sc_ifas[index - 1] = ifa;
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ifa->ifa_carp = sc;
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carp_hmac_prepare(sc);
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carp_sc_state(sc);
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CARP_UNLOCK(sc);
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CIF_UNLOCK(cif);
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sx_xunlock(&carp_sx);
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return (0);
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}
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void
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carp_detach(struct ifaddr *ifa)
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{
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struct ifnet *ifp = ifa->ifa_ifp;
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struct carp_if *cif = ifp->if_carp;
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CIF_LOCK(cif);
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carp_detach_locked(ifa);
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CIF_FREE(cif);
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}
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static void
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carp_detach_locked(struct ifaddr *ifa)
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{
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struct ifnet *ifp = ifa->ifa_ifp;
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struct carp_if *cif = ifp->if_carp;
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@ -1906,9 +1880,9 @@ carp_detach_locked(struct ifaddr *ifa)
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KASSERT(sc != NULL, ("%s: %p not attached", __func__, ifa));
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CIF_LOCK_ASSERT(cif);
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CARP_LOCK(sc);
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sx_xlock(&carp_sx);
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CARP_LOCK(sc);
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/* Shift array. */
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index = sc->sc_naddrs + sc->sc_naddrs6;
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for (i = 0; i < index; i++)
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@ -1943,11 +1917,14 @@ carp_detach_locked(struct ifaddr *ifa)
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carp_hmac_prepare(sc);
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carp_sc_state(sc);
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if (sc->sc_naddrs == 0 && sc->sc_naddrs6 == 0) {
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CARP_UNLOCK(sc);
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if (sc->sc_naddrs == 0 && sc->sc_naddrs6 == 0)
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carp_destroy(sc);
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} else
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else
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CARP_UNLOCK(sc);
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CIF_FREE(cif);
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sx_xunlock(&carp_sx);
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}
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static void
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