Commit c15b1cca authored by Hannes Frederic Sowa's avatar Hannes Frederic Sowa Committed by David S. Miller
Browse files

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]  <IRQ>  [<ffffffff8148a9f0>] ? dump_stack+0xd/0x17
[  541.031180]  [<ffffffff813c98c1>] ? __dev_set_promiscuity+0x101/0x180
[  541.031183]  [<ffffffff813d3540>] ? __hw_addr_create_ex+0x60/0xc0
[  541.031185]  [<ffffffff813cfe1a>] ? __dev_set_rx_mode+0xaa/0xc0
[  541.031189]  [<ffffffff813d3a81>] ? __dev_mc_add+0x61/0x90
[  541.031198]  [<ffffffffa01dcf9c>] ? igmp6_group_added+0xfc/0x1a0 [ipv6]
[  541.031208]  [<ffffffff8111237b>] ? kmem_cache_alloc+0xcb/0xd0
[  541.031212]  [<ffffffffa01ddcd7>] ? ipv6_dev_mc_inc+0x267/0x300 [ipv6]
[  541.031216]  [<ffffffffa01c2fae>] ? addrconf_join_solict+0x2e/0x40 [ipv6]
[  541.031219]  [<ffffffffa01ba2e9>] ? ipv6_dev_ac_inc+0x159/0x1f0 [ipv6]
[  541.031223]  [<ffffffffa01c0772>] ? addrconf_join_anycast+0x92/0xa0 [ipv6]
[  541.031226]  [<ffffffffa01c311e>] ? __ipv6_ifa_notify+0x11e/0x1e0 [ipv6]
[  541.031229]  [<ffffffffa01c3213>] ? ipv6_ifa_notify+0x33/0x50 [ipv6]
[  541.031233]  [<ffffffffa01c36c8>] ? addrconf_dad_completed+0x28/0x100 [ipv6]
[  541.031241]  [<ffffffff81075c1d>] ? task_cputime+0x2d/0x50
[  541.031244]  [<ffffffffa01c38d6>] ? addrconf_dad_timer+0x136/0x150 [ipv6]
[  541.031247]  [<ffffffffa01c37a0>] ? addrconf_dad_completed+0x100/0x100 [ipv6]
[  541.031255]  [<ffffffff8105313a>] ? call_timer_fn.isra.22+0x2a/0x90
[  541.031258]  [<ffffffffa01c37a0>] ? addrconf_dad_completed+0x100/0x100 [ipv6]

Hunks and backtrace stolen from a patch by Stephen Hemminger.
Reported-by: Stephen Hemminger's avatarStephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Stephen Hemminger's avatarStephen Hemminger <stephen@networkplumber.org>
Signed-off-by: default avatarHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent e2a1d3e4
......@@ -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;
......
......@@ -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 @@ void addrconf_prefix_rcv(struct net_device *dev, u8 *opt, int len, bool sllao)
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 @@ void addrconf_prefix_rcv(struct net_device *dev, u8 *opt, int len, bool sllao)
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 @@ static void addrconf_dad_start(struct inet6_ifaddr *ifp)
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 @@ static void addrconf_verify(unsigned long foo)
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 @@ int __init addrconf_init(void)
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);
}
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