From c15b1ccadb323ea50023e8f1cca2954129a62b51 Mon Sep 17 00:00:00 2001 From: Hannes Frederic Sowa Date: Thu, 27 Mar 2014 18:28:07 +0100 Subject: [PATCH] ipv6: move DAD and addrconf_verify processing to workqueue addrconf_join_solict and addrconf_join_anycast may cause actions which need rtnl locked, especially on first address creation. A new DAD state is introduced which defers processing of the initial DAD processing into a workqueue. To get rtnl lock we need to push the code paths which depend on those calls up to workqueues, specifically addrconf_verify and the DAD processing. (v2) addrconf_dad_failure needs to be queued up to the workqueue, too. This patch introduces a new DAD state and stop the DAD processing in the workqueue (this is because of the possible ipv6_del_addr processing which removes the solicited multicast address from the device). addrconf_verify_lock is removed, too. After the transition it is not needed any more. As we are not processing in bottom half anymore we need to be a bit more careful about disabling bottom half out when we lock spin_locks which are also used in bh. Relevant backtrace: [ 541.030090] RTNL: assertion failed at net/core/dev.c (4496) [ 541.031143] CPU: 0 PID: 0 Comm: swapper/0 Tainted: G O 3.10.33-1-amd64-vyatta #1 [ 541.031145] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007 [ 541.031146] ffffffff8148a9f0 000000000000002f ffffffff813c98c1 ffff88007c4451f8 [ 541.031148] 0000000000000000 0000000000000000 ffffffff813d3540 ffff88007fc03d18 [ 541.031150] 0000880000000006 ffff88007c445000 ffffffffa0194160 0000000000000000 [ 541.031152] Call Trace: [ 541.031153] [] ? dump_stack+0xd/0x17 [ 541.031180] [] ? __dev_set_promiscuity+0x101/0x180 [ 541.031183] [] ? __hw_addr_create_ex+0x60/0xc0 [ 541.031185] [] ? __dev_set_rx_mode+0xaa/0xc0 [ 541.031189] [] ? __dev_mc_add+0x61/0x90 [ 541.031198] [] ? igmp6_group_added+0xfc/0x1a0 [ipv6] [ 541.031208] [] ? kmem_cache_alloc+0xcb/0xd0 [ 541.031212] [] ? ipv6_dev_mc_inc+0x267/0x300 [ipv6] [ 541.031216] [] ? addrconf_join_solict+0x2e/0x40 [ipv6] [ 541.031219] [] ? ipv6_dev_ac_inc+0x159/0x1f0 [ipv6] [ 541.031223] [] ? addrconf_join_anycast+0x92/0xa0 [ipv6] [ 541.031226] [] ? __ipv6_ifa_notify+0x11e/0x1e0 [ipv6] [ 541.031229] [] ? ipv6_ifa_notify+0x33/0x50 [ipv6] [ 541.031233] [] ? addrconf_dad_completed+0x28/0x100 [ipv6] [ 541.031241] [] ? task_cputime+0x2d/0x50 [ 541.031244] [] ? addrconf_dad_timer+0x136/0x150 [ipv6] [ 541.031247] [] ? addrconf_dad_completed+0x100/0x100 [ipv6] [ 541.031255] [] ? call_timer_fn.isra.22+0x2a/0x90 [ 541.031258] [] ? addrconf_dad_completed+0x100/0x100 [ipv6] Hunks and backtrace stolen from a patch by Stephen Hemminger. Reported-by: Stephen Hemminger Signed-off-by: Stephen Hemminger Signed-off-by: Hannes Frederic Sowa Signed-off-by: David S. Miller --- include/net/if_inet6.h | 4 +- net/ipv6/addrconf.c | 193 ++++++++++++++++++++++++++++++----------- 2 files changed, 145 insertions(+), 52 deletions(-) diff --git a/include/net/if_inet6.h b/include/net/if_inet6.h index 9650a3ffd2d2..b4956a5fcc3f 100644 --- a/include/net/if_inet6.h +++ b/include/net/if_inet6.h @@ -31,8 +31,10 @@ #define IF_PREFIX_AUTOCONF 0x02 enum { + INET6_IFADDR_STATE_PREDAD, INET6_IFADDR_STATE_DAD, INET6_IFADDR_STATE_POSTDAD, + INET6_IFADDR_STATE_ERRDAD, INET6_IFADDR_STATE_UP, INET6_IFADDR_STATE_DEAD, }; @@ -58,7 +60,7 @@ struct inet6_ifaddr { unsigned long cstamp; /* created timestamp */ unsigned long tstamp; /* updated timestamp */ - struct timer_list dad_timer; + struct delayed_work dad_work; struct inet6_dev *idev; struct rt6_info *rt; diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index 344e972426df..6c7fa0853fc7 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -133,10 +133,12 @@ static int ipv6_count_addresses(struct inet6_dev *idev); static struct hlist_head inet6_addr_lst[IN6_ADDR_HSIZE]; static DEFINE_SPINLOCK(addrconf_hash_lock); -static void addrconf_verify(unsigned long); +static void addrconf_verify(void); +static void addrconf_verify_rtnl(void); +static void addrconf_verify_work(struct work_struct *); -static DEFINE_TIMER(addr_chk_timer, addrconf_verify, 0, 0); -static DEFINE_SPINLOCK(addrconf_verify_lock); +static struct workqueue_struct *addrconf_wq; +static DECLARE_DELAYED_WORK(addr_chk_work, addrconf_verify_work); static void addrconf_join_anycast(struct inet6_ifaddr *ifp); static void addrconf_leave_anycast(struct inet6_ifaddr *ifp); @@ -151,7 +153,7 @@ static struct rt6_info *addrconf_get_prefix_route(const struct in6_addr *pfx, u32 flags, u32 noflags); static void addrconf_dad_start(struct inet6_ifaddr *ifp); -static void addrconf_dad_timer(unsigned long data); +static void addrconf_dad_work(struct work_struct *w); static void addrconf_dad_completed(struct inet6_ifaddr *ifp); static void addrconf_dad_run(struct inet6_dev *idev); static void addrconf_rs_timer(unsigned long data); @@ -247,9 +249,9 @@ static void addrconf_del_rs_timer(struct inet6_dev *idev) __in6_dev_put(idev); } -static void addrconf_del_dad_timer(struct inet6_ifaddr *ifp) +static void addrconf_del_dad_work(struct inet6_ifaddr *ifp) { - if (del_timer(&ifp->dad_timer)) + if (cancel_delayed_work(&ifp->dad_work)) __in6_ifa_put(ifp); } @@ -261,12 +263,12 @@ static void addrconf_mod_rs_timer(struct inet6_dev *idev, mod_timer(&idev->rs_timer, jiffies + when); } -static void addrconf_mod_dad_timer(struct inet6_ifaddr *ifp, - unsigned long when) +static void addrconf_mod_dad_work(struct inet6_ifaddr *ifp, + unsigned long delay) { - if (!timer_pending(&ifp->dad_timer)) + if (!delayed_work_pending(&ifp->dad_work)) in6_ifa_hold(ifp); - mod_timer(&ifp->dad_timer, jiffies + when); + mod_delayed_work(addrconf_wq, &ifp->dad_work, delay); } static int snmp6_alloc_dev(struct inet6_dev *idev) @@ -751,8 +753,9 @@ void inet6_ifa_finish_destroy(struct inet6_ifaddr *ifp) in6_dev_put(ifp->idev); - if (del_timer(&ifp->dad_timer)) - pr_notice("Timer is still running, when freeing ifa=%p\n", ifp); + if (cancel_delayed_work(&ifp->dad_work)) + pr_notice("delayed DAD work was pending while freeing ifa=%p\n", + ifp); if (ifp->state != INET6_IFADDR_STATE_DEAD) { pr_warn("Freeing alive inet6 address %p\n", ifp); @@ -849,8 +852,7 @@ ipv6_add_addr(struct inet6_dev *idev, const struct in6_addr *addr, spin_lock_init(&ifa->lock); spin_lock_init(&ifa->state_lock); - setup_timer(&ifa->dad_timer, addrconf_dad_timer, - (unsigned long)ifa); + INIT_DELAYED_WORK(&ifa->dad_work, addrconf_dad_work); INIT_HLIST_NODE(&ifa->addr_lst); ifa->scope = scope; ifa->prefix_len = pfxlen; @@ -990,6 +992,8 @@ static void ipv6_del_addr(struct inet6_ifaddr *ifp) enum cleanup_prefix_rt_t action = CLEANUP_PREFIX_RT_NOP; unsigned long expires; + ASSERT_RTNL(); + spin_lock_bh(&ifp->state_lock); state = ifp->state; ifp->state = INET6_IFADDR_STATE_DEAD; @@ -1021,7 +1025,7 @@ static void ipv6_del_addr(struct inet6_ifaddr *ifp) write_unlock_bh(&ifp->idev->lock); - addrconf_del_dad_timer(ifp); + addrconf_del_dad_work(ifp); ipv6_ifa_notify(RTM_DELADDR, ifp); @@ -1604,7 +1608,7 @@ static void addrconf_dad_stop(struct inet6_ifaddr *ifp, int dad_failed) { if (ifp->flags&IFA_F_PERMANENT) { spin_lock_bh(&ifp->lock); - addrconf_del_dad_timer(ifp); + addrconf_del_dad_work(ifp); ifp->flags |= IFA_F_TENTATIVE; if (dad_failed) ifp->flags |= IFA_F_DADFAILED; @@ -1625,20 +1629,21 @@ static void addrconf_dad_stop(struct inet6_ifaddr *ifp, int dad_failed) spin_unlock_bh(&ifp->lock); } ipv6_del_addr(ifp); - } else + } else { ipv6_del_addr(ifp); + } } static int addrconf_dad_end(struct inet6_ifaddr *ifp) { int err = -ENOENT; - spin_lock(&ifp->state_lock); + spin_lock_bh(&ifp->state_lock); if (ifp->state == INET6_IFADDR_STATE_DAD) { ifp->state = INET6_IFADDR_STATE_POSTDAD; err = 0; } - spin_unlock(&ifp->state_lock); + spin_unlock_bh(&ifp->state_lock); return err; } @@ -1671,7 +1676,12 @@ void addrconf_dad_failure(struct inet6_ifaddr *ifp) } } - addrconf_dad_stop(ifp, 1); + spin_lock_bh(&ifp->state_lock); + /* transition from _POSTDAD to _ERRDAD */ + ifp->state = INET6_IFADDR_STATE_ERRDAD; + spin_unlock_bh(&ifp->state_lock); + + addrconf_mod_dad_work(ifp, 0); } /* Join to solicited addr multicast group. */ @@ -1680,6 +1690,8 @@ void addrconf_join_solict(struct net_device *dev, const struct in6_addr *addr) { struct in6_addr maddr; + ASSERT_RTNL(); + if (dev->flags&(IFF_LOOPBACK|IFF_NOARP)) return; @@ -1691,6 +1703,8 @@ void addrconf_leave_solict(struct inet6_dev *idev, const struct in6_addr *addr) { struct in6_addr maddr; + ASSERT_RTNL(); + if (idev->dev->flags&(IFF_LOOPBACK|IFF_NOARP)) return; @@ -1701,6 +1715,9 @@ void addrconf_leave_solict(struct inet6_dev *idev, const struct in6_addr *addr) static void addrconf_join_anycast(struct inet6_ifaddr *ifp) { struct in6_addr addr; + + ASSERT_RTNL(); + if (ifp->prefix_len >= 127) /* RFC 6164 */ return; ipv6_addr_prefix(&addr, &ifp->addr, ifp->prefix_len); @@ -1712,6 +1729,9 @@ static void addrconf_join_anycast(struct inet6_ifaddr *ifp) static void addrconf_leave_anycast(struct inet6_ifaddr *ifp) { struct in6_addr addr; + + ASSERT_RTNL(); + if (ifp->prefix_len >= 127) /* RFC 6164 */ return; ipv6_addr_prefix(&addr, &ifp->addr, ifp->prefix_len); @@ -2271,11 +2291,13 @@ ok: return; } - ifp->flags |= IFA_F_MANAGETEMPADDR; update_lft = 0; create = 1; + spin_lock_bh(&ifp->lock); + ifp->flags |= IFA_F_MANAGETEMPADDR; ifp->cstamp = jiffies; ifp->tokenized = tokenized; + spin_unlock_bh(&ifp->lock); addrconf_dad_start(ifp); } @@ -2326,7 +2348,7 @@ ok: create, now); in6_ifa_put(ifp); - addrconf_verify(0); + addrconf_verify(); } } inet6_prefix_notify(RTM_NEWPREFIX, in6_dev, pinfo); @@ -2475,7 +2497,7 @@ static int inet6_addr_add(struct net *net, int ifindex, manage_tempaddrs(idev, ifp, valid_lft, prefered_lft, true, jiffies); in6_ifa_put(ifp); - addrconf_verify(0); + addrconf_verify_rtnl(); return 0; } @@ -3011,7 +3033,7 @@ static int addrconf_ifdown(struct net_device *dev, int how) hlist_for_each_entry_rcu(ifa, h, addr_lst) { if (ifa->idev == idev) { hlist_del_init_rcu(&ifa->addr_lst); - addrconf_del_dad_timer(ifa); + addrconf_del_dad_work(ifa); goto restart; } } @@ -3049,7 +3071,7 @@ static int addrconf_ifdown(struct net_device *dev, int how) while (!list_empty(&idev->addr_list)) { ifa = list_first_entry(&idev->addr_list, struct inet6_ifaddr, if_list); - addrconf_del_dad_timer(ifa); + addrconf_del_dad_work(ifa); list_del(&ifa->if_list); @@ -3148,10 +3170,10 @@ static void addrconf_dad_kick(struct inet6_ifaddr *ifp) rand_num = prandom_u32() % (idev->cnf.rtr_solicit_delay ? : 1); ifp->dad_probes = idev->cnf.dad_transmits; - addrconf_mod_dad_timer(ifp, rand_num); + addrconf_mod_dad_work(ifp, rand_num); } -static void addrconf_dad_start(struct inet6_ifaddr *ifp) +static void addrconf_dad_begin(struct inet6_ifaddr *ifp) { struct inet6_dev *idev = ifp->idev; struct net_device *dev = idev->dev; @@ -3203,25 +3225,68 @@ out: read_unlock_bh(&idev->lock); } -static void addrconf_dad_timer(unsigned long data) +static void addrconf_dad_start(struct inet6_ifaddr *ifp) { - struct inet6_ifaddr *ifp = (struct inet6_ifaddr *) data; + bool begin_dad = false; + + spin_lock_bh(&ifp->state_lock); + if (ifp->state != INET6_IFADDR_STATE_DEAD) { + ifp->state = INET6_IFADDR_STATE_PREDAD; + begin_dad = true; + } + spin_unlock_bh(&ifp->state_lock); + + if (begin_dad) + addrconf_mod_dad_work(ifp, 0); +} + +static void addrconf_dad_work(struct work_struct *w) +{ + struct inet6_ifaddr *ifp = container_of(to_delayed_work(w), + struct inet6_ifaddr, + dad_work); struct inet6_dev *idev = ifp->idev; struct in6_addr mcaddr; + enum { + DAD_PROCESS, + DAD_BEGIN, + DAD_ABORT, + } action = DAD_PROCESS; + + rtnl_lock(); + + spin_lock_bh(&ifp->state_lock); + if (ifp->state == INET6_IFADDR_STATE_PREDAD) { + action = DAD_BEGIN; + ifp->state = INET6_IFADDR_STATE_DAD; + } else if (ifp->state == INET6_IFADDR_STATE_ERRDAD) { + action = DAD_ABORT; + ifp->state = INET6_IFADDR_STATE_POSTDAD; + } + spin_unlock_bh(&ifp->state_lock); + + if (action == DAD_BEGIN) { + addrconf_dad_begin(ifp); + goto out; + } else if (action == DAD_ABORT) { + addrconf_dad_stop(ifp, 1); + goto out; + } + if (!ifp->dad_probes && addrconf_dad_end(ifp)) goto out; - write_lock(&idev->lock); + write_lock_bh(&idev->lock); if (idev->dead || !(idev->if_flags & IF_READY)) { - write_unlock(&idev->lock); + write_unlock_bh(&idev->lock); goto out; } spin_lock(&ifp->lock); if (ifp->state == INET6_IFADDR_STATE_DEAD) { spin_unlock(&ifp->lock); - write_unlock(&idev->lock); + write_unlock_bh(&idev->lock); goto out; } @@ -3232,7 +3297,7 @@ static void addrconf_dad_timer(unsigned long data) ifp->flags &= ~(IFA_F_TENTATIVE|IFA_F_OPTIMISTIC|IFA_F_DADFAILED); spin_unlock(&ifp->lock); - write_unlock(&idev->lock); + write_unlock_bh(&idev->lock); addrconf_dad_completed(ifp); @@ -3240,16 +3305,17 @@ static void addrconf_dad_timer(unsigned long data) } ifp->dad_probes--; - addrconf_mod_dad_timer(ifp, - NEIGH_VAR(ifp->idev->nd_parms, RETRANS_TIME)); + addrconf_mod_dad_work(ifp, + NEIGH_VAR(ifp->idev->nd_parms, RETRANS_TIME)); spin_unlock(&ifp->lock); - write_unlock(&idev->lock); + write_unlock_bh(&idev->lock); /* send a neighbour solicitation for our addr */ addrconf_addr_solict_mult(&ifp->addr, &mcaddr); ndisc_send_ns(ifp->idev->dev, NULL, &ifp->addr, &mcaddr, &in6addr_any); out: in6_ifa_put(ifp); + rtnl_unlock(); } /* ifp->idev must be at least read locked */ @@ -3276,7 +3342,7 @@ static void addrconf_dad_completed(struct inet6_ifaddr *ifp) struct in6_addr lladdr; bool send_rs, send_mld; - addrconf_del_dad_timer(ifp); + addrconf_del_dad_work(ifp); /* * Configure the address for reception. Now it is valid. @@ -3517,23 +3583,23 @@ int ipv6_chk_home_addr(struct net *net, const struct in6_addr *addr) * Periodic address status verification */ -static void addrconf_verify(unsigned long foo) +static void addrconf_verify_rtnl(void) { unsigned long now, next, next_sec, next_sched; struct inet6_ifaddr *ifp; int i; + ASSERT_RTNL(); + rcu_read_lock_bh(); - spin_lock(&addrconf_verify_lock); now = jiffies; next = round_jiffies_up(now + ADDR_CHECK_FREQUENCY); - del_timer(&addr_chk_timer); + cancel_delayed_work(&addr_chk_work); for (i = 0; i < IN6_ADDR_HSIZE; i++) { restart: - hlist_for_each_entry_rcu_bh(ifp, - &inet6_addr_lst[i], addr_lst) { + hlist_for_each_entry_rcu_bh(ifp, &inet6_addr_lst[i], addr_lst) { unsigned long age; /* When setting preferred_lft to a value not zero or @@ -3628,13 +3694,22 @@ restart: ADBG(KERN_DEBUG "now = %lu, schedule = %lu, rounded schedule = %lu => %lu\n", now, next, next_sec, next_sched); - - addr_chk_timer.expires = next_sched; - add_timer(&addr_chk_timer); - spin_unlock(&addrconf_verify_lock); + mod_delayed_work(addrconf_wq, &addr_chk_work, next_sched - now); rcu_read_unlock_bh(); } +static void addrconf_verify_work(struct work_struct *w) +{ + rtnl_lock(); + addrconf_verify_rtnl(); + rtnl_unlock(); +} + +static void addrconf_verify(void) +{ + mod_delayed_work(addrconf_wq, &addr_chk_work, 0); +} + static struct in6_addr *extract_addr(struct nlattr *addr, struct nlattr *local, struct in6_addr **peer_pfx) { @@ -3691,6 +3766,8 @@ static int inet6_addr_modify(struct inet6_ifaddr *ifp, u32 ifa_flags, bool was_managetempaddr; bool had_prefixroute; + ASSERT_RTNL(); + if (!valid_lft || (prefered_lft > valid_lft)) return -EINVAL; @@ -3756,7 +3833,7 @@ static int inet6_addr_modify(struct inet6_ifaddr *ifp, u32 ifa_flags, !was_managetempaddr, jiffies); } - addrconf_verify(0); + addrconf_verify_rtnl(); return 0; } @@ -4386,6 +4463,8 @@ static int inet6_set_iftoken(struct inet6_dev *idev, struct in6_addr *token) bool update_rs = false; struct in6_addr ll_addr; + ASSERT_RTNL(); + if (token == NULL) return -EINVAL; if (ipv6_addr_any(token)) @@ -4434,7 +4513,7 @@ static int inet6_set_iftoken(struct inet6_dev *idev, struct in6_addr *token) } write_unlock_bh(&idev->lock); - addrconf_verify(0); + addrconf_verify_rtnl(); return 0; } @@ -4636,6 +4715,9 @@ static void __ipv6_ifa_notify(int event, struct inet6_ifaddr *ifp) { struct net *net = dev_net(ifp->idev->dev); + if (event) + ASSERT_RTNL(); + inet6_ifa_notify(event ? : RTM_NEWADDR, ifp); switch (event) { @@ -5244,6 +5326,12 @@ int __init addrconf_init(void) if (err < 0) goto out_addrlabel; + addrconf_wq = create_workqueue("ipv6_addrconf"); + if (!addrconf_wq) { + err = -ENOMEM; + goto out_nowq; + } + /* The addrconf netdev notifier requires that loopback_dev * has it's ipv6 private information allocated and setup * before it can bring up and give link-local addresses @@ -5274,7 +5362,7 @@ int __init addrconf_init(void) register_netdevice_notifier(&ipv6_dev_notf); - addrconf_verify(0); + addrconf_verify(); rtnl_af_register(&inet6_ops); @@ -5302,6 +5390,8 @@ errout: rtnl_af_unregister(&inet6_ops); unregister_netdevice_notifier(&ipv6_dev_notf); errlo: + destroy_workqueue(addrconf_wq); +out_nowq: unregister_pernet_subsys(&addrconf_ops); out_addrlabel: ipv6_addr_label_cleanup(); @@ -5337,7 +5427,8 @@ void addrconf_cleanup(void) for (i = 0; i < IN6_ADDR_HSIZE; i++) WARN_ON(!hlist_empty(&inet6_addr_lst[i])); spin_unlock_bh(&addrconf_hash_lock); - - del_timer(&addr_chk_timer); + cancel_delayed_work(&addr_chk_work); rtnl_unlock(); + + destroy_workqueue(addrconf_wq); } -- 2.34.1