When ipoib interface is going down it takes all of its children with
it, under mutex.
For each child, dev_change_flags() is called. That function calls
ipoib_stop() via the ndo, and causes flush of the workqueue.
Sometimes in the workqueue an __ipoib_dev_flush work() is waiting and
when invoked tries to get the same mutex, which leads to a deadlock,
as seen below.
The solution is to switch to rw-sem instead of mutex.
The deadlock:
[11028.165303] [<
ffffffff812b0977>] ? vgacon_scroll+0x107/0x2e0
[11028.171844] [<
ffffffff814eaac5>] schedule_timeout+0x215/0x2e0
[11028.178465] [<
ffffffff8105a5c3>] ? perf_event_task_sched_out+0x33/0x80
[11028.185962] [<
ffffffff814ea743>] wait_for_common+0x123/0x180
[11028.192491] [<
ffffffff8105fa40>] ? default_wake_function+0x0/0x20
[11028.199504] [<
ffffffff814ea85d>] wait_for_completion+0x1d/0x20
[11028.206224] [<
ffffffff8108b4f1>] flush_cpu_workqueue+0x61/0x90
[11028.212948] [<
ffffffff8108b5a0>] ? wq_barrier_func+0x0/0x20
[11028.219375] [<
ffffffff8108bfc4>] flush_workqueue+0x54/0x80
[11028.225712] [<
ffffffffa05a0576>] ipoib_mcast_stop_thread+0x66/0x90 [ib_ipoib]
[11028.233988] [<
ffffffffa059ccea>] ipoib_ib_dev_down+0x6a/0x100 [ib_ipoib]
[11028.241678] [<
ffffffffa059849a>] ipoib_stop+0x8a/0x140 [ib_ipoib]
[11028.248692] [<
ffffffff8142adf1>] dev_close+0x71/0xc0
[11028.254447] [<
ffffffff8142a631>] dev_change_flags+0xa1/0x1d0
[11028.261062] [<
ffffffffa059851b>] ipoib_stop+0x10b/0x140 [ib_ipoib]
[11028.268172] [<
ffffffff8142adf1>] dev_close+0x71/0xc0
[11028.273922] [<
ffffffff8142a631>] dev_change_flags+0xa1/0x1d0
[11028.280452] [<
ffffffff8148f20b>] devinet_ioctl+0x5eb/0x6a0
[11028.286786] [<
ffffffff814903b8>] inet_ioctl+0x88/0xa0
[11028.292633] [<
ffffffff8141591a>] sock_ioctl+0x7a/0x280
[11028.298576] [<
ffffffff81189012>] vfs_ioctl+0x22/0xa0
[11028.304326] [<
ffffffff81140540>] ? unmap_region+0x110/0x130
[11028.310756] [<
ffffffff811891b4>] do_vfs_ioctl+0x84/0x580
[11028.316897] [<
ffffffff81189731>] sys_ioctl+0x81/0xa0
and
11028.017533] [<
ffffffff8105a5c3>] ? perf_event_task_sched_out+0x33/0x80
[11028.025030] [<
ffffffff8100bb8e>] ? apic_timer_interrupt+0xe/0x20
[11028.031945] [<
ffffffff814eb2ae>] __mutex_lock_slowpath+0x13e/0x180
[11028.039053] [<
ffffffff814eb14b>] mutex_lock+0x2b/0x50
[11028.044910] [<
ffffffffa059f7e7>] __ipoib_ib_dev_flush+0x37/0x210 [ib_ipoib]
[11028.052894] [<
ffffffffa059fa00>] ? ipoib_ib_dev_flush_light+0x0/0x20 [ib_ipoib]
[11028.061363] [<
ffffffffa059fa17>] ipoib_ib_dev_flush_light+0x17/0x20 [ib_ipoib]
[11028.069738] [<
ffffffff8108b120>] worker_thread+0x170/0x2a0
[11028.076068] [<
ffffffff81090990>] ? autoremove_wake_function+0x0/0x40
[11028.083374] [<
ffffffff8108afb0>] ? worker_thread+0x0/0x2a0
[11028.089709] [<
ffffffff81090626>] kthread+0x96/0xa0
[11028.095266] [<
ffffffff8100c0ca>] child_rip+0xa/0x20
[11028.100921] [<
ffffffff81090590>] ? kthread+0x0/0xa0
[11028.106573] [<
ffffffff8100c0c0>] ? child_rip+0x0/0x20
[11028.112423] INFO: task ifconfig:23640 blocked for more than 120 seconds.
Signed-off-by: Erez Shitrit <erezsh@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
unsigned long flags;
- struct mutex vlan_mutex;
+ struct rw_semaphore vlan_rwsem;
struct rb_root path_tree;
struct list_head path_list;
u16 new_index;
int result;
- mutex_lock(&priv->vlan_mutex);
+ down_read(&priv->vlan_rwsem);
/*
* Flush any child interfaces too -- they might be up even if
list_for_each_entry(cpriv, &priv->child_intfs, list)
__ipoib_ib_dev_flush(cpriv, level);
- mutex_unlock(&priv->vlan_mutex);
+ up_read(&priv->vlan_rwsem);
if (!test_bit(IPOIB_FLAG_INITIALIZED, &priv->flags)) {
/* for non-child devices must check/update the pkey value here */
struct ipoib_dev_priv *cpriv;
/* Bring up any child interfaces too */
- mutex_lock(&priv->vlan_mutex);
+ down_read(&priv->vlan_rwsem);
list_for_each_entry(cpriv, &priv->child_intfs, list) {
int flags;
dev_change_flags(cpriv->dev, flags | IFF_UP);
}
- mutex_unlock(&priv->vlan_mutex);
+ up_read(&priv->vlan_rwsem);
}
netif_start_queue(dev);
struct ipoib_dev_priv *cpriv;
/* Bring down any child interfaces too */
- mutex_lock(&priv->vlan_mutex);
+ down_read(&priv->vlan_rwsem);
list_for_each_entry(cpriv, &priv->child_intfs, list) {
int flags;
dev_change_flags(cpriv->dev, flags & ~IFF_UP);
}
- mutex_unlock(&priv->vlan_mutex);
+ up_read(&priv->vlan_rwsem);
}
return 0;
spin_lock_init(&priv->lock);
- mutex_init(&priv->vlan_mutex);
+ init_rwsem(&priv->vlan_rwsem);
INIT_LIST_HEAD(&priv->path_list);
INIT_LIST_HEAD(&priv->child_intfs);
priv = netdev_priv(dev);
ppriv = netdev_priv(priv->parent);
- mutex_lock(&ppriv->vlan_mutex);
+ down_write(&ppriv->vlan_rwsem);
unregister_netdevice_queue(dev, head);
list_del(&priv->list);
- mutex_unlock(&ppriv->vlan_mutex);
+ up_write(&ppriv->vlan_rwsem);
}
static size_t ipoib_get_size(const struct net_device *dev)
if (!rtnl_trylock())
return restart_syscall();
- mutex_lock(&ppriv->vlan_mutex);
+ down_write(&ppriv->vlan_rwsem);
/*
* First ensure this isn't a duplicate. We check the parent device and
result = __ipoib_vlan_add(ppriv, priv, pkey, IPOIB_LEGACY_CHILD);
out:
- mutex_unlock(&ppriv->vlan_mutex);
+ up_write(&ppriv->vlan_rwsem);
if (result)
free_netdev(priv->dev);
if (!rtnl_trylock())
return restart_syscall();
- mutex_lock(&ppriv->vlan_mutex);
+
+ down_write(&ppriv->vlan_rwsem);
list_for_each_entry_safe(priv, tpriv, &ppriv->child_intfs, list) {
if (priv->pkey == pkey &&
priv->child_type == IPOIB_LEGACY_CHILD) {
break;
}
}
- mutex_unlock(&ppriv->vlan_mutex);
+ up_write(&ppriv->vlan_rwsem);
+
rtnl_unlock();
if (dev) {
projects / GitHub / moto-9609 / android_kernel_motorola_exynos9610.git / commitdiff