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| author |   Erez Shitrit <erezsh@mellanox.com> | 2013-10-16 17:37:49 +0300 |
|---|---|---|
| committer |   Roland Dreier <roland@purestorage.com> | 2013-11-08 14:42:49 -0800 |
| commit | f47944cc2dba3c7e6f753b81e9f713f4d12bdd5a (patch) | |
| tree | 4dd24c53d8041eff9f251c9debf63bd54be083d8 /drivers/infiniband/ulp/ipoib/ipoib_vlan.c | |
| parent | IPoIB: Change CM skb memory allocation to be non-atomic during init (diff) | |
| download | linux-dev-f47944cc2dba3c7e6f753b81e9f713f4d12bdd5a.tar.xz linux-dev-f47944cc2dba3c7e6f753b81e9f713f4d12bdd5a.zip | |
IPoIB: Fix deadlock between dev_change_flags() and __ipoib_dev_flush()
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>
Diffstat (limited to 'drivers/infiniband/ulp/ipoib/ipoib_vlan.c')
| -rw-r--r-- | drivers/infiniband/ulp/ipoib/ipoib_vlan.c | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/drivers/infiniband/ulp/ipoib/ipoib_vlan.c b/drivers/infiniband/ulp/ipoib/ipoib_vlan.c index 8292554bccb5..9fad7b5ac8b9 100644 --- a/drivers/infiniband/ulp/ipoib/ipoib_vlan.c +++ b/drivers/infiniband/ulp/ipoib/ipoib_vlan.c @@ -140,7 +140,7 @@ int ipoib_vlan_add(struct net_device *pdev, unsigned short pkey) 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 @@ -163,7 +163,7 @@ int ipoib_vlan_add(struct net_device *pdev, unsigned short pkey) 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); @@ -185,7 +185,8 @@ int ipoib_vlan_delete(struct net_device *pdev, unsigned short pkey) 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) { @@ -195,7 +196,8 @@ int ipoib_vlan_delete(struct net_device *pdev, unsigned short pkey) break; } } - mutex_unlock(&ppriv->vlan_mutex); + up_write(&ppriv->vlan_rwsem); + rtnl_unlock(); if (dev) { |