[ovs-dev] [PATCH net-next] openvswitch: fix vport-netdev unregister

Pravin Shelar pshelar at nicira.com
Thu Oct 10 06:07:17 UTC 2013


On Wed, Oct 9, 2013 at 9:11 PM, Alexei Starovoitov <ast at plumgrid.com> wrote:
> On Wed, Oct 9, 2013 at 8:02 PM, Pravin Shelar <pshelar at nicira.com> wrote:
>> On Tue, Oct 8, 2013 at 8:07 PM, Alexei Starovoitov <ast at plumgrid.com> wrote:
>>> The combination of two commits
>>>
>>> commit 8e4e1713e4
>>> ("openvswitch: Simplify datapath locking.")
>>>
>>> and
>>>
>>> commit 2537b4dd0a
>>> ("openvswitch:: link upper device for port devices")
>>>
>>> introduced a bug where upper_dev wasn't unlinked upon
>>> netdev_unregister notification
>>>
>>> The following steps:
>>>
>>>   modprobe openvswitch
>>>   ovs-dpctl add-dp test
>>>   ip tuntap add dev tap1 mode tap
>>>   ovs-dpctl add-if test tap1
>>>   ip tuntap del dev tap1 mode tap
>>>
>>> are causing multiple warnings:
>>>
>>> [   62.747557] gre: GRE over IPv4 demultiplexor driver
>>> [   62.749579] openvswitch: Open vSwitch switching datapath
>>> [   62.755087] device test entered promiscuous mode
>>> [   62.765911] device tap1 entered promiscuous mode
>>> [   62.766033] IPv6: ADDRCONF(NETDEV_UP): tap1: link is not ready
>>> [   62.769017] ------------[ cut here ]------------
>>> [   62.769022] WARNING: CPU: 1 PID: 3267 at net/core/dev.c:5501 rollback_registered_many+0x20f/0x240()
>>> [   62.769023] Modules linked in: openvswitch gre vxlan ip_tunnel libcrc32c ip6table_filter ip6_tables ebtable_nat ebtables nf_conntrack_ipv4 nf_defrag_ipv4 xt_state nf_conntrack xt_CHECKSUM iptable_mangle ipt_REJECT xt_tcpudp iptable_filter ip_tables x_tables bridge stp llc vhost_net macvtap macvlan vhost kvm_intel kvm dm_crypt iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi hid_generic mxm_wmi eeepc_wmi asus_wmi sparse_keymap dm_multipath psmouse serio_raw usbhid hid parport_pc ppdev firewire_ohci lpc_ich firewire_core e1000e crc_itu_t binfmt_misc igb dca ptp pps_core mac_hid wmi lp parport i2o_config i2o_block video
>>> [   62.769051] CPU: 1 PID: 3267 Comm: ip Not tainted 3.12.0-rc3+ #60
>>> [   62.769052] Hardware name: System manufacturer System Product Name/P8Z77 WS, BIOS 3007 07/26/2012
>>> [   62.769053]  0000000000000009 ffff8807f25cbd28 ffffffff8175e575 0000000000000006
>>> [   62.769055]  0000000000000000 ffff8807f25cbd68 ffffffff8105314c ffff8807f25cbd58
>>> [   62.769057]  ffff8807f2634000 ffff8807f25cbdc8 ffff8807f25cbd88 ffff8807f25cbdc8
>>> [   62.769059] Call Trace:
>>> [   62.769062]  [<ffffffff8175e575>] dump_stack+0x55/0x76
>>> [   62.769065]  [<ffffffff8105314c>] warn_slowpath_common+0x8c/0xc0
>>> [   62.769067]  [<ffffffff8105319a>] warn_slowpath_null+0x1a/0x20
>>> [   62.769069]  [<ffffffff8162a04f>] rollback_registered_many+0x20f/0x240
>>> [   62.769071]  [<ffffffff8162a101>] rollback_registered+0x31/0x40
>>> [   62.769073]  [<ffffffff8162a488>] unregister_netdevice_queue+0x58/0x90
>>> [   62.769075]  [<ffffffff8154f900>] __tun_detach+0x140/0x340
>>> [   62.769077]  [<ffffffff8154fb36>] tun_chr_close+0x36/0x60
>>> [   62.769080]  [<ffffffff811bddaf>] __fput+0xff/0x260
>>> [   62.769082]  [<ffffffff811bdf5e>] ____fput+0xe/0x10
>>> [   62.769084]  [<ffffffff8107b515>] task_work_run+0xb5/0xe0
>>> [   62.769087]  [<ffffffff810029b9>] do_notify_resume+0x59/0x80
>>> [   62.769089]  [<ffffffff813a41fe>] ? trace_hardirqs_on_thunk+0x3a/0x3f
>>> [   62.769091]  [<ffffffff81770f5a>] int_signal+0x12/0x17
>>> [   62.769093] ---[ end trace 838756c62e156ffb ]---
>>> [   62.769481] ------------[ cut here ]------------
>>> [   62.769485] WARNING: CPU: 1 PID: 92 at fs/sysfs/inode.c:325 sysfs_hash_and_remove+0xa9/0xb0()
>>> [   62.769486] sysfs: can not remove 'master', no directory
>>> [   62.769486] Modules linked in: openvswitch gre vxlan ip_tunnel libcrc32c ip6table_filter ip6_tables ebtable_nat ebtables nf_conntrack_ipv4 nf_defrag_ipv4 xt_state nf_conntrack xt_CHECKSUM iptable_mangle ipt_REJECT xt_tcpudp iptable_filter ip_tables x_tables bridge stp llc vhost_net macvtap macvlan vhost kvm_intel kvm dm_crypt iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi hid_generic mxm_wmi eeepc_wmi asus_wmi sparse_keymap dm_multipath psmouse serio_raw usbhid hid parport_pc ppdev firewire_ohci lpc_ich firewire_core e1000e crc_itu_t binfmt_misc igb dca ptp pps_core mac_hid wmi lp parport i2o_config i2o_block video
>>> [   62.769514] CPU: 1 PID: 92 Comm: kworker/1:2 Tainted: G        W    3.12.0-rc3+ #60
>>> [   62.769515] Hardware name: System manufacturer System Product Name/P8Z77 WS, BIOS 3007 07/26/2012
>>> [   62.769518] Workqueue: events ovs_dp_notify_wq [openvswitch]
>>> [   62.769519]  0000000000000009 ffff880807ad3ac8 ffffffff8175e575 0000000000000006
>>> [   62.769521]  ffff880807ad3b18 ffff880807ad3b08 ffffffff8105314c ffff880807ad3b28
>>> [   62.769523]  0000000000000000 ffffffff81a87a1f ffff8807f2634000 ffff880037038500
>>> [   62.769525] Call Trace:
>>> [   62.769528]  [<ffffffff8175e575>] dump_stack+0x55/0x76
>>> [   62.769529]  [<ffffffff8105314c>] warn_slowpath_common+0x8c/0xc0
>>> [   62.769531]  [<ffffffff81053236>] warn_slowpath_fmt+0x46/0x50
>>> [   62.769533]  [<ffffffff8123e7e9>] sysfs_hash_and_remove+0xa9/0xb0
>>> [   62.769535]  [<ffffffff81240e96>] sysfs_remove_link+0x26/0x30
>>> [   62.769538]  [<ffffffff81631ef7>] __netdev_adjacent_dev_remove+0xf7/0x150
>>> [   62.769540]  [<ffffffff81632037>] __netdev_adjacent_dev_unlink_lists+0x27/0x50
>>> [   62.769542]  [<ffffffff8163213a>] __netdev_adjacent_dev_unlink_neighbour+0x3a/0x50
>>> [   62.769544]  [<ffffffff8163218d>] netdev_upper_dev_unlink+0x3d/0x140
>>> [   62.769548]  [<ffffffffa033c2db>] netdev_destroy+0x4b/0x80 [openvswitch]
>>> [   62.769550]  [<ffffffffa033b696>] ovs_vport_del+0x46/0x60 [openvswitch]
>>> [   62.769552]  [<ffffffffa0335314>] ovs_dp_detach_port+0x44/0x60 [openvswitch]
>>> [   62.769555]  [<ffffffffa0336574>] ovs_dp_notify_wq+0xb4/0x150 [openvswitch]
>>> [   62.769557]  [<ffffffff81075c28>] process_one_work+0x1d8/0x6a0
>>> [   62.769559]  [<ffffffff81075bc8>] ? process_one_work+0x178/0x6a0
>>> [   62.769562]  [<ffffffff8107659b>] worker_thread+0x11b/0x370
>>> [   62.769564]  [<ffffffff81076480>] ? rescuer_thread+0x350/0x350
>>> [   62.769566]  [<ffffffff8107f44a>] kthread+0xea/0xf0
>>> [   62.769568]  [<ffffffff8107f360>] ? flush_kthread_worker+0x150/0x150
>>> [   62.769570]  [<ffffffff81770bac>] ret_from_fork+0x7c/0xb0
>>> [   62.769572]  [<ffffffff8107f360>] ? flush_kthread_worker+0x150/0x150
>>> [   62.769573] ---[ end trace 838756c62e156ffc ]---
>>> [   62.769574] ------------[ cut here ]------------
>>> [   62.769576] WARNING: CPU: 1 PID: 92 at fs/sysfs/inode.c:325 sysfs_hash_and_remove+0xa9/0xb0()
>>> [   62.769577] sysfs: can not remove 'upper_test', no directory
>>> [   62.769577] Modules linked in: openvswitch gre vxlan ip_tunnel libcrc32c ip6table_filter ip6_tables ebtable_nat ebtables nf_conntrack_ipv4 nf_defrag_ipv4 xt_state nf_conntrack xt_CHECKSUM iptable_mangle ipt_REJECT xt_tcpudp iptable_filter ip_tables x_tables bridge stp llc vhost_net macvtap macvlan vhost kvm_intel kvm dm_crypt iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi hid_generic mxm_wmi eeepc_wmi asus_wmi sparse_keymap dm_multipath psmouse serio_raw usbhid hid parport_pc ppdev firewire_ohci lpc_ich firewire_core e1000e crc_itu_t binfmt_misc igb dca ptp pps_core mac_hid wmi lp parport i2o_config i2o_block video
>>> [   62.769603] CPU: 1 PID: 92 Comm: kworker/1:2 Tainted: G        W    3.12.0-rc3+ #60
>>> [   62.769604] Hardware name: System manufacturer System Product Name/P8Z77 WS, BIOS 3007 07/26/2012
>>> [   62.769606] Workqueue: events ovs_dp_notify_wq [openvswitch]
>>> [   62.769607]  0000000000000009 ffff880807ad3ac8 ffffffff8175e575 0000000000000006
>>> [   62.769609]  ffff880807ad3b18 ffff880807ad3b08 ffffffff8105314c ffff880807ad3b58
>>> [   62.769611]  0000000000000000 ffff880807ad3bd9 ffff8807f2634000 ffff880037038500
>>> [   62.769613] Call Trace:
>>> [   62.769615]  [<ffffffff8175e575>] dump_stack+0x55/0x76
>>> [   62.769617]  [<ffffffff8105314c>] warn_slowpath_common+0x8c/0xc0
>>> [   62.769619]  [<ffffffff81053236>] warn_slowpath_fmt+0x46/0x50
>>> [   62.769621]  [<ffffffff8123e7e9>] sysfs_hash_and_remove+0xa9/0xb0
>>> [   62.769622]  [<ffffffff81240e96>] sysfs_remove_link+0x26/0x30
>>> [   62.769624]  [<ffffffff81631f22>] __netdev_adjacent_dev_remove+0x122/0x150
>>> [   62.769627]  [<ffffffff81632037>] __netdev_adjacent_dev_unlink_lists+0x27/0x50
>>> [   62.769629]  [<ffffffff8163213a>] __netdev_adjacent_dev_unlink_neighbour+0x3a/0x50
>>> [   62.769631]  [<ffffffff8163218d>] netdev_upper_dev_unlink+0x3d/0x140
>>> [   62.769633]  [<ffffffffa033c2db>] netdev_destroy+0x4b/0x80 [openvswitch]
>>> [   62.769636]  [<ffffffffa033b696>] ovs_vport_del+0x46/0x60 [openvswitch]
>>> [   62.769638]  [<ffffffffa0335314>] ovs_dp_detach_port+0x44/0x60 [openvswitch]
>>> [   62.769640]  [<ffffffffa0336574>] ovs_dp_notify_wq+0xb4/0x150 [openvswitch]
>>> [   62.769642]  [<ffffffff81075c28>] process_one_work+0x1d8/0x6a0
>>> [   62.769644]  [<ffffffff81075bc8>] ? process_one_work+0x178/0x6a0
>>> [   62.769646]  [<ffffffff8107659b>] worker_thread+0x11b/0x370
>>> [   62.769648]  [<ffffffff81076480>] ? rescuer_thread+0x350/0x350
>>> [   62.769650]  [<ffffffff8107f44a>] kthread+0xea/0xf0
>>> [   62.769652]  [<ffffffff8107f360>] ? flush_kthread_worker+0x150/0x150
>>> [   62.769654]  [<ffffffff81770bac>] ret_from_fork+0x7c/0xb0
>>> [   62.769656]  [<ffffffff8107f360>] ? flush_kthread_worker+0x150/0x150
>>> [   62.769657] ---[ end trace 838756c62e156ffd ]---
>>> [   62.769724] device tap1 left promiscuous mode
>>>
>>> Signed-off-by: Alexei Starovoitov <ast at plumgrid.com>
>>> ---
>>>  net/openvswitch/dp_notify.c    |    5 +++++
>>>  net/openvswitch/vport-netdev.c |   16 +++++++++++++---
>>>  net/openvswitch/vport-netdev.h |    1 +
>>>  3 files changed, 19 insertions(+), 3 deletions(-)
>>>
>>> diff --git a/net/openvswitch/dp_notify.c b/net/openvswitch/dp_notify.c
>>> index c323567..e9380bd 100644
>>> --- a/net/openvswitch/dp_notify.c
>>> +++ b/net/openvswitch/dp_notify.c
>>> @@ -88,6 +88,11 @@ static int dp_device_event(struct notifier_block *unused, unsigned long event,
>>>                 return NOTIFY_DONE;
>>>
>>>         if (event == NETDEV_UNREGISTER) {
>>> +               /* rx_handler_unregister and upper_dev_unlink immediately */
>>> +               if (dev->reg_state == NETREG_UNREGISTERING)
>>> +                       ovs_netdev_unlink_dev(vport);
>>> +
>>
>> Rather than doing vport destroy here, we can just unlink upper device
>> and let workq do rest of work.
>
> isn't it what it's doing?

I meant just call netdev_upper_dev_unlink() here in event handler and
rest of vport destroy can be done in workq.

> It does unregister and unlink immediately and schedules workq to do destroy.
> Obviously destroy cannot happen here, since we cannot grab ovs_lock here,
> since it would be in the wrong order vs the rest of the code.
>
>>
>> Thanks.
>>



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