Re: [PATCH] nfs lockd: detect grace_list corruption

[Wang Chen <wangchen@cn.fujitsu.com>]

J. Bruce Fields said the following on 2009-5-12 4:57:
> On Mon, May 11, 2009 at 02:13:50PM +0800, Wang Chen wrote:
>> J. Bruce Fields said the following on 2009-5-9 2:26:
>>> On Thu, May 07, 2009 at 02:51:23PM +0800, Wang Chen wrote:
>>>> J. Bruce Fields said the following on 2009-5-7 4:32:
>>>>> On Wed, May 06, 2009 at 05:17:20PM +0800, Wang Chen wrote:
>>>>>> J. Bruce Fields said the following on 2009-4-25 7:12:
>>>>>>> On Fri, Apr 24, 2009 at 11:09:44AM +0800, Wang Chen wrote:
>>>>>>>> Although I can't reproduce it now, it really happened that some lock manager
>>>>>>>> started grace period but didn't end it.
>>>>>>>> This causes an lm entry be left in grace_list, and when service nfs restart,
>>>>>>>> the same lm will be added again into the list.
>>>>>>>> As you know, adding an entry, which is in the list, to a list will leads to
>>>>>>>> list corruption.
>>>>>>> I'd really like to understand why locks_end_grace() isn't being called.
>>>>>>> I'm probably overlooking something obvious, but I just can't see how
>>>>>>> lockd or nfsd can be shut down right now without locks_end_grace() being
>>>>>>> called.
>>>>>>>
>>>>>> Me neither can figure out why locks_end_grace() isn't being called.
>>>>>>
>>>>>> But do locks_start_grace() twice can trigger this warning too.
>>>>>> You can do
>>>>>> 1. service nfs restart
>>>>>> 2. (immediately) kill -s SIGKILL lockd
>>>>>> this can trigger
>>>>>> ---
>>>>>> lockd(void *vrqstp)
>>>>>> ...
>>>>>> 		if (signalled()) {
>>>>>> 			flush_signals(current);
>>>>>> 			if (nlmsvc_ops) {
>>>>>> 				nlmsvc_invalidate_all();
>>>>>> 				set_grace_period();
>>>>>> ---
>>>>>> and makes locks_start_grace() be called twice without locks_end_grace().
>>>>> Ah-hah!
>>>>>
>>>>>> So I still suggest to do something to protect the lm list. :)
>>>>> I wouldn't be opposed to a simple WARN_ON(!list_empty()) in
>>>>> locks_start_grace(), but I'm mainly worried about fixing the original
>>>>> bug.  How about the following?
>>>>>
>>>> Yeah, the following fix is OK to me, although it only fixed
>>>> "start_grace again after start_grace" case.
>>> OK, thanks.
>>>
>>>> The bug about "quit lockd without end_grace", which I encountered before
>>>> incidentally, maybe is still there.
>>> You're talking about the report that started this thread?:
>>>
>>> 	http://marc.info/?l=linux-nfs&m=124054262421444&w=2
>>>
>> Yes. I mean this.
>>
>>> It looks to me like that could be explained by two start_grace's in a
>>> row.
>>>
>> But in that report, I didn't post the total message.
>> Here are something show that:
>> 1. not only lockd has the problem, but nfsd also.
>> 2. every time I do "service nfs restart", I got the warning, so this is not
>>    "two start_grace's in a row" problem.
> 
> Once the list is corrupted, it stays corrupted, so that's expected; the
> only interesting warning is the first one.
> 

But as you see the logs, nfsd made list corrupted first.
Your fix only "two start_grace's in a row" of lockd .

> --b.
> 
>> Following is more message I got on last month.
>> ------------------------------------------------------
>> Apr 16 16:35:41 localhost mountd[15061]: Caught signal 15, un-registering and exiting.
>> Apr 16 16:35:42 localhost kernel: nfsd: last server has exited, flushing export cache
>> Apr 16 16:35:43 localhost kernel: NFSD: Using /var/lib/nfs/v4recovery as the NFSv4 state recovery directory
>> Apr 16 16:35:43 localhost kernel: ------------[ cut here ]------------
>> Apr 16 16:35:43 localhost kernel: WARNING: at lib/list_debug.c:26 __list_add+0x27/0x5c()
>> Apr 16 16:35:43 localhost kernel: Hardware name: Presario M2000 (PT365PA#AB2)      
>> Apr 16 16:35:43 localhost kernel: list_add corruption. next->prev should be prev (ef8fe958), but was ef8ff128. (next=ef8ff128).
>> Apr 16 16:35:43 localhost kernel: Modules linked in: fuse i915 drm i2c_algo_bit nfsd lockd nfs_acl auth_rpcgss exportfs sunrpc ipv6 p4_clockmod dm_multipath uinput snd_intel8x0m snd_intel8x0 snd_seq_dummy snd_ac97_codec ac97_bus snd_seq_oss snd_seq_midi_event snd_seq snd_seq_device snd_pcm_oss snd_mixer_oss snd_pcm snd_timer snd soundcore 8139cp firewire_ohci firewire_core snd_page_alloc tifm_7xx1 i2c_i801 iTCO_wdt 8139too tifm_core i2c_core yenta_socket crc_itu_t iTCO_vendor_support pcspkr mii rsrc_nonstatic wmi video output ata_generic pata_acpi [last unloaded: microcode]
>> Apr 16 16:35:43 localhost kernel: Pid: 17455, comm: rpc.nfsd Tainted: G        W  2.6.30-rc2 #3
>> Apr 16 16:35:43 localhost kernel: Call Trace:
>> Apr 16 16:35:43 localhost kernel: [<c042d5b5>] warn_slowpath+0x71/0xa0
>> Apr 16 16:35:43 localhost kernel: [<efc17dec>] ? nfsd4_build_namelist+0x0/0x8e [nfsd]
>> Apr 16 16:35:43 localhost kernel: [<c044b12d>] ? trace_hardirqs_on_caller+0x18/0x150
>> Apr 16 16:35:43 localhost kernel: [<c051c61a>] ? _raw_spin_lock+0x53/0xfa
>> Apr 16 16:35:43 localhost kernel: [<c04a3f66>] ? mntput_no_expire+0x1c/0x101
>> Apr 16 16:35:43 localhost kernel: [<c04a0062>] ? dput+0x35/0x103
>> Apr 16 16:35:43 localhost kernel: [<c051c61a>] ? _raw_spin_lock+0x53/0xfa
>> Apr 16 16:35:43 localhost kernel: [<c051c89f>] __list_add+0x27/0x5c
>> Apr 16 16:35:43 localhost kernel: [<ef8f6daa>] locks_start_grace+0x22/0x30 [lockd]
>> Apr 16 16:35:43 localhost kernel: [<efc13a49>] nfs4_state_start+0x7a/0xdd [nfsd]
>> Apr 16 16:35:43 localhost kernel: [<efbfd5be>] nfsd_svc+0x57/0xf9 [nfsd]
>> Apr 16 16:35:43 localhost kernel: [<efbfdff6>] ? write_threads+0x0/0x59 [nfsd]
>> Apr 16 16:35:43 localhost kernel: [<efbfe02b>] write_threads+0x35/0x59 [nfsd]
>> Apr 16 16:35:43 localhost kernel: [<efbfd84d>] nfsctl_transaction_write+0x3b/0x58 [nfsd]
>> Apr 16 16:35:43 localhost kernel: [<efbfd812>] ? nfsctl_transaction_write+0x0/0x58 [nfsd]
>> Apr 16 16:35:43 localhost kernel: [<c04927af>] vfs_write+0x7c/0xad
>> Apr 16 16:35:43 localhost kernel: [<c0492879>] sys_write+0x3b/0x60
>> Apr 16 16:35:43 localhost kernel: [<c0403148>] sysenter_do_call+0x12/0x3c
>> Apr 16 16:35:43 localhost kernel: ---[ end trace fa484bd6d19ade87 ]---
>> Apr 16 16:35:43 localhost kernel: NFSD: starting 90-second grace period
>> ...snip...
>> Apr 17 13:02:54 localhost mountd[17468]: Caught signal 15, un-registering and exiting.
>> Apr 17 13:02:54 localhost kernel: nfsd: last server has exited, flushing export cache
>> Apr 17 13:02:55 localhost kernel: NFSD: Using /var/lib/nfs/v4recovery as the NFSv4 state recovery directory
>> Apr 17 13:02:55 localhost kernel: ------------[ cut here ]------------
>> Apr 17 13:02:55 localhost kernel: WARNING: at lib/list_debug.c:26 __list_add+0x27/0x5c()
>> Apr 17 13:02:55 localhost kernel: Hardware name: Presario M2000 (PT365PA#AB2)      
>> Apr 17 13:02:55 localhost kernel: list_add corruption. next->prev should be prev (ef8fe958), but was ef8ff128. (next=ef8ff128).
>> Apr 17 13:02:55 localhost kernel: Modules linked in: fuse i915 drm i2c_algo_bit nfsd lockd nfs_acl auth_rpcgss exportfs sunrpc ipv6 p4_clockmod dm_multipath uinput snd_intel8x0m snd_intel8x0 snd_seq_dummy snd_ac97_codec ac97_bus snd_seq_oss snd_seq_midi_event snd_seq snd_seq_device snd_pcm_oss snd_mixer_oss snd_pcm snd_timer snd soundcore 8139cp firewire_ohci firewire_core snd_page_alloc tifm_7xx1 i2c_i801 iTCO_wdt 8139too tifm_core i2c_core yenta_socket crc_itu_t iTCO_vendor_support pcspkr mii rsrc_nonstatic wmi video output ata_generic pata_acpi [last unloaded: microcode]
>> Apr 17 13:02:55 localhost kernel: Pid: 22642, comm: rpc.nfsd Tainted: G        W  2.6.30-rc2 #3
>> Apr 17 13:02:55 localhost kernel: Call Trace:
>> Apr 17 13:02:55 localhost kernel: [<c042d5b5>] warn_slowpath+0x71/0xa0
>> Apr 17 13:02:55 localhost kernel: [<efc17dec>] ? nfsd4_build_namelist+0x0/0x8e [nfsd]
>> Apr 17 13:02:55 localhost kernel: [<c044b12d>] ? trace_hardirqs_on_caller+0x18/0x150
>> Apr 17 13:02:55 localhost kernel: [<c051c61a>] ? _raw_spin_lock+0x53/0xfa
>> Apr 17 13:02:55 localhost kernel: [<c04a3f66>] ? mntput_no_expire+0x1c/0x101
>> Apr 17 13:02:55 localhost kernel: [<c04a0062>] ? dput+0x35/0x103
>> Apr 17 13:02:55 localhost kernel: [<c051c61a>] ? _raw_spin_lock+0x53/0xfa
>> Apr 17 13:02:55 localhost kernel: [<c051c89f>] __list_add+0x27/0x5c
>> Apr 17 13:02:55 localhost kernel: [<ef8f6daa>] locks_start_grace+0x22/0x30 [lockd]
>> Apr 17 13:02:55 localhost kernel: [<efc13a49>] nfs4_state_start+0x7a/0xdd [nfsd]
>> Apr 17 13:02:55 localhost kernel: [<efbfd5be>] nfsd_svc+0x57/0xf9 [nfsd]
>> Apr 17 13:02:55 localhost kernel: [<efbfdff6>] ? write_threads+0x0/0x59 [nfsd]
>> Apr 17 13:02:55 localhost kernel: [<efbfe02b>] write_threads+0x35/0x59 [nfsd]
>> Apr 17 13:02:55 localhost kernel: [<efbfd84d>] nfsctl_transaction_write+0x3b/0x58 [nfsd]
>> Apr 17 13:02:55 localhost kernel: [<efbfd812>] ? nfsctl_transaction_write+0x0/0x58 [nfsd]
>> Apr 17 13:02:55 localhost kernel: [<c04927af>] vfs_write+0x7c/0xad
>> Apr 17 13:02:55 localhost kernel: [<c0492879>] sys_write+0x3b/0x60
>> Apr 17 13:02:55 localhost kernel: [<c0403148>] sysenter_do_call+0x12/0x3c
>> Apr 17 13:02:55 localhost kernel: ---[ end trace fa484bd6d19ade88 ]---
>> Apr 17 13:02:55 localhost kernel: NFSD: starting 90-second grace period
>> Apr 17 13:04:07 localhost mountd[22655]: Caught signal 15, un-registering and exiting.
>> Apr 17 13:04:07 localhost kernel: nfsd: last server has exited, flushing export cache
>> Apr 17 13:04:07 localhost kernel: NFSD: Using /var/lib/nfs/v4recovery as the NFSv4 state recovery directory
>> Apr 17 13:04:07 localhost kernel: NFSD: starting 90-second grace period
>> Apr 17 13:05:04 localhost mountd[22760]: Caught signal 15, un-registering and exiting.
>> Apr 17 13:05:04 localhost kernel: nfsd: last server has exited, flushing export cache
>> Apr 17 13:05:05 localhost kernel: NFSD: Using /var/lib/nfs/v4recovery as the NFSv4 state recovery directory
>> Apr 17 13:05:05 localhost kernel: NFSD: starting 90-second grace period
>> Apr 17 13:06:10 localhost mountd[22859]: Caught signal 15, un-registering and exiting.
>> Apr 17 13:06:10 localhost kernel: nfsd: last server has exited, flushing export cache
>> Apr 17 13:06:10 localhost kernel: NFSD: Using /var/lib/nfs/v4recovery as the NFSv4 state recovery directory
>> Apr 17 13:06:10 localhost kernel: NFSD: starting 90-second grace period
>> Apr 17 13:08:07 localhost mountd[22960]: Caught signal 15, un-registering and exiting.
>> Apr 17 13:08:07 localhost kernel: nfsd: last server has exited, flushing export cache
>> Apr 17 13:08:07 localhost kernel: ------------[ cut here ]------------
>> Apr 17 13:08:07 localhost kernel: WARNING: at lib/list_debug.c:26 __list_add+0x27/0x5c()
>> Apr 17 13:08:07 localhost kernel: Hardware name: Presario M2000 (PT365PA#AB2)      
>> Apr 17 13:08:07 localhost kernel: list_add corruption. next->prev should be prev (ef8fe958), but was ef8ff128. (next=ef8ff128).
>> Apr 17 13:08:07 localhost kernel: Modules linked in: fuse i915 drm i2c_algo_bit nfsd lockd nfs_acl auth_rpcgss exportfs sunrpc ipv6 p4_clockmod dm_multipath uinput snd_intel8x0m snd_intel8x0 snd_seq_dummy snd_ac97_codec ac97_bus snd_seq_oss snd_seq_midi_event snd_seq snd_seq_device snd_pcm_oss snd_mixer_oss snd_pcm snd_timer snd soundcore 8139cp firewire_ohci firewire_core snd_page_alloc tifm_7xx1 i2c_i801 iTCO_wdt 8139too tifm_core i2c_core yenta_socket crc_itu_t iTCO_vendor_support pcspkr mii rsrc_nonstatic wmi video output ata_generic pata_acpi [last unloaded: microcode]
>> Apr 17 13:08:07 localhost kernel: Pid: 23062, comm: lockd Tainted: G        W  2.6.30-rc2 #3
>> Apr 17 13:08:07 localhost kernel: Call Trace:
>> Apr 17 13:08:07 localhost kernel: [<c042d5b5>] warn_slowpath+0x71/0xa0
>> Apr 17 13:08:07 localhost kernel: [<c0422a96>] ? update_curr+0x11d/0x125
>> Apr 17 13:08:07 localhost kernel: [<c044b12d>] ? trace_hardirqs_on_caller+0x18/0x150
>> Apr 17 13:08:07 localhost kernel: [<c044b270>] ? trace_hardirqs_on+0xb/0xd
>> Apr 17 13:08:07 localhost kernel: [<c051c61a>] ? _raw_spin_lock+0x53/0xfa
>> Apr 17 13:08:07 localhost kernel: [<c051c89f>] __list_add+0x27/0x5c
>> Apr 17 13:08:07 localhost kernel: [<ef8f6daa>] locks_start_grace+0x22/0x30 [lockd]
>> Apr 17 13:08:07 localhost kernel: [<ef8f34da>] set_grace_period+0x39/0x53 [lockd]
>> Apr 17 13:08:07 localhost kernel: [<c06b8921>] ? lock_kernel+0x1c/0x28
>> Apr 17 13:08:07 localhost kernel: [<ef8f3558>] lockd+0x64/0x164 [lockd]
>> Apr 17 13:08:07 localhost kernel: [<c044b12d>] ? trace_hardirqs_on_caller+0x18/0x150
>> Apr 17 13:08:07 localhost kernel: [<c04227b0>] ? complete+0x34/0x3e
>> Apr 17 13:08:07 localhost kernel: [<ef8f34f4>] ? lockd+0x0/0x164 [lockd]
>> Apr 17 13:08:07 localhost kernel: [<ef8f34f4>] ? lockd+0x0/0x164 [lockd]
>> Apr 17 13:08:07 localhost kernel: [<c043dd42>] kthread+0x45/0x6b
>> Apr 17 13:08:07 localhost kernel: [<c043dcfd>] ? kthread+0x0/0x6b
>> Apr 17 13:08:07 localhost kernel: [<c0403c23>] kernel_thread_helper+0x7/0x10
>> Apr 17 13:08:07 localhost kernel: ---[ end trace fa484bd6d19ade89 ]---
>> Apr 17 13:08:07 localhost kernel: NFSD: Using /var/lib/nfs/v4recovery as the NFSv4 state recovery directory
>> Apr 17 13:08:07 localhost kernel: NFSD: starting 90-second grace period
>> Apr 17 14:39:45 localhost mountd[23074]: Caught signal 15, un-registering and exiting.
>> Apr 17 14:39:45 localhost kernel: nfsd: last server has exited, flushing export cache
>> Apr 17 14:39:45 localhost kernel: ------------[ cut here ]------------
>> Apr 17 14:39:45 localhost kernel: WARNING: at lib/list_debug.c:26 __list_add+0x27/0x5c()
>> Apr 17 14:39:45 localhost kernel: Hardware name: Presario M2000 (PT365PA#AB2)      
>> Apr 17 14:39:45 localhost kernel: list_add corruption. next->prev should be prev (ef8fe958), but was ef8ff128. (next=ef8ff128).
>> Apr 17 14:39:45 localhost kernel: Modules linked in: fuse i915 drm i2c_algo_bit nfsd lockd nfs_acl auth_rpcgss exportfs sunrpc ipv6 p4_clockmod dm_multipath uinput snd_intel8x0m snd_intel8x0 snd_seq_dummy snd_ac97_codec ac97_bus snd_seq_oss snd_seq_midi_event snd_seq snd_seq_device snd_pcm_oss snd_mixer_oss snd_pcm snd_timer snd soundcore 8139cp firewire_ohci firewire_core snd_page_alloc tifm_7xx1 i2c_i801 iTCO_wdt 8139too tifm_core i2c_core yenta_socket crc_itu_t iTCO_vendor_support pcspkr mii rsrc_nonstatic wmi video output ata_generic pata_acpi [last unloaded: microcode]
>> Apr 17 14:39:45 localhost kernel: Pid: 24287, comm: lockd Tainted: G        W  2.6.30-rc2 #3
>> Apr 17 14:39:45 localhost kernel: Call Trace:
>> Apr 17 14:39:45 localhost kernel: [<c042d5b5>] warn_slowpath+0x71/0xa0
>> Apr 17 14:39:45 localhost kernel: [<c0422a96>] ? update_curr+0x11d/0x125
>> Apr 17 14:39:45 localhost kernel: [<c044b12d>] ? trace_hardirqs_on_caller+0x18/0x150
>> Apr 17 14:39:45 localhost kernel: [<c044b270>] ? trace_hardirqs_on+0xb/0xd
>> Apr 17 14:39:45 localhost kernel: [<c051c61a>] ? _raw_spin_lock+0x53/0xfa
>> Apr 17 14:39:45 localhost kernel: [<c051c89f>] __list_add+0x27/0x5c
>> Apr 17 14:39:45 localhost kernel: [<ef8f6daa>] locks_start_grace+0x22/0x30 [lockd]
>> Apr 17 14:39:45 localhost kernel: [<ef8f34da>] set_grace_period+0x39/0x53 [lockd]
>> Apr 17 14:39:45 localhost kernel: [<c06b8921>] ? lock_kernel+0x1c/0x28
>> Apr 17 14:39:45 localhost kernel: [<ef8f3558>] lockd+0x64/0x164 [lockd]
>> Apr 17 14:39:45 localhost kernel: [<c044b12d>] ? trace_hardirqs_on_caller+0x18/0x150
>> Apr 17 14:39:45 localhost kernel: [<c04227b0>] ? complete+0x34/0x3e
>> Apr 17 14:39:45 localhost kernel: [<ef8f34f4>] ? lockd+0x0/0x164 [lockd]
>> Apr 17 14:39:45 localhost kernel: [<ef8f34f4>] ? lockd+0x0/0x164 [lockd]
>> Apr 17 14:39:45 localhost kernel: [<c043dd42>] kthread+0x45/0x6b
>> Apr 17 14:39:45 localhost kernel: [<c043dcfd>] ? kthread+0x0/0x6b
>> Apr 17 14:39:45 localhost kernel: [<c0403c23>] kernel_thread_helper+0x7/0x10
>> Apr 17 14:39:45 localhost kernel: ---[ end trace fa484bd6d19ade8a ]---
>> Apr 17 14:39:45 localhost kernel: NFSD: Using /var/lib/nfs/v4recovery as the NFSv4 state recovery directory
>> Apr 17 14:39:45 localhost kernel: NFSD: starting 90-second grace period
>> Apr 17 14:41:32 localhost mountd[24299]: Caught signal 15, un-registering and exiting.
>> Apr 17 14:41:32 localhost kernel: nfsd: last server has exited, flushing export cache
>> Apr 17 14:41:33 localhost kernel: ------------[ cut here ]------------
>> Apr 17 14:41:33 localhost kernel: WARNING: at lib/list_debug.c:26 __list_add+0x27/0x5c()
>> Apr 17 14:41:33 localhost kernel: Hardware name: Presario M2000 (PT365PA#AB2)      
>> Apr 17 14:41:33 localhost kernel: list_add corruption. next->prev should be prev (ef8fe958), but was ef8ff128. (next=ef8ff128).
>> Apr 17 14:41:33 localhost kernel: Modules linked in: fuse i915 drm i2c_algo_bit nfsd lockd nfs_acl auth_rpcgss exportfs sunrpc ipv6 p4_clockmod dm_multipath uinput snd_intel8x0m snd_intel8x0 snd_seq_dummy snd_ac97_codec ac97_bus snd_seq_oss snd_seq_midi_event snd_seq snd_seq_device snd_pcm_oss snd_mixer_oss snd_pcm snd_timer snd soundcore 8139cp firewire_ohci firewire_core snd_page_alloc tifm_7xx1 i2c_i801 iTCO_wdt 8139too tifm_core i2c_core yenta_socket crc_itu_t iTCO_vendor_support pcspkr mii rsrc_nonstatic wmi video output ata_generic pata_acpi [last unloaded: microcode]
>> Apr 17 14:41:33 localhost kernel: Pid: 24399, comm: lockd Tainted: G        W  2.6.30-rc2 #3
>> Apr 17 14:41:33 localhost kernel: Call Trace:
>> Apr 17 14:41:33 localhost kernel: [<c042d5b5>] warn_slowpath+0x71/0xa0
>> Apr 17 14:41:33 localhost kernel: [<c0422a96>] ? update_curr+0x11d/0x125
>> Apr 17 14:41:33 localhost kernel: [<c044b12d>] ? trace_hardirqs_on_caller+0x18/0x150
>> Apr 17 14:41:33 localhost kernel: [<c044b270>] ? trace_hardirqs_on+0xb/0xd
>> Apr 17 14:41:33 localhost kernel: [<c051c61a>] ? _raw_spin_lock+0x53/0xfa
>> Apr 17 14:41:33 localhost kernel: [<c051c89f>] __list_add+0x27/0x5c
>> Apr 17 14:41:33 localhost kernel: [<ef8f6daa>] locks_start_grace+0x22/0x30 [lockd]
>> Apr 17 14:41:33 localhost kernel: [<ef8f34da>] set_grace_period+0x39/0x53 [lockd]
>> Apr 17 14:41:33 localhost kernel: [<c06b8921>] ? lock_kernel+0x1c/0x28
>> Apr 17 14:41:33 localhost kernel: [<ef8f3558>] lockd+0x64/0x164 [lockd]
>> Apr 17 14:41:33 localhost kernel: [<c044b12d>] ? trace_hardirqs_on_caller+0x18/0x150
>> Apr 17 14:41:33 localhost kernel: [<c04227b0>] ? complete+0x34/0x3e
>> Apr 17 14:41:33 localhost kernel: [<ef8f34f4>] ? lockd+0x0/0x164 [lockd]
>> Apr 17 14:41:33 localhost kernel: [<ef8f34f4>] ? lockd+0x0/0x164 [lockd]
>> Apr 17 14:41:33 localhost kernel: [<c043dd42>] kthread+0x45/0x6b
>> Apr 17 14:41:33 localhost kernel: [<c043dcfd>] ? kthread+0x0/0x6b
>> Apr 17 14:41:33 localhost kernel: [<c0403c23>] kernel_thread_helper+0x7/0x10
>> Apr 17 14:41:33 localhost kernel: ---[ end trace fa484bd6d19ade8b ]---
>> Apr 17 14:41:33 localhost kernel: NFSD: Using /var/lib/nfs/v4recovery as the NFSv4 state recovery directory
>> Apr 17 14:41:33 localhost kernel: NFSD: starting 90-second grace period
>> Apr 17 14:42:16 localhost mountd[24411]: Caught signal 15, un-registering and exiting.
>> Apr 17 14:42:17 localhost kernel: nfsd: last server has exited, flushing export cache
>> Apr 17 14:42:17 localhost kernel: NFSD: Using /var/lib/nfs/v4recovery as the NFSv4 state recovery directory
>> Apr 17 14:42:17 localhost kernel: NFSD: starting 90-second grace period
>> Apr 17 14:42:52 localhost mountd[24508]: Caught signal 15, un-registering and exiting.
>> Apr 17 14:42:52 localhost kernel: nfsd: last server has exited, flushing export cache
>> Apr 17 14:42:53 localhost kernel: NFSD: Using /var/lib/nfs/v4recovery as the NFSv4 state recovery directory
>> Apr 17 14:42:53 localhost kernel: NFSD: starting 90-second grace period
>> Apr 17 14:43:28 localhost mountd[24602]: Caught signal 15, un-registering and exiting.
>> Apr 17 14:43:28 localhost kernel: nfsd: last server has exited, flushing export cache
>> Apr 17 14:43:29 localhost kernel: NFSD: Using /var/lib/nfs/v4recovery as the NFSv4 state recovery directory
>> Apr 17 14:43:29 localhost kernel: NFSD: starting 90-second grace period
>> Apr 17 14:43:59 localhost mountd[24697]: Caught signal 15, un-registering and exiting.
>> Apr 17 14:43:59 localhost kernel: nfsd: last server has exited, flushing export cache
>> Apr 17 14:44:00 localhost kernel: NFSD: Using /var/lib/nfs/v4recovery as the NFSv4 state recovery directory
>> Apr 17 14:44:00 localhost kernel: NFSD: starting 90-second grace period
>> Apr 17 14:44:28 localhost mountd[24791]: Caught signal 15, un-registering and exiting.
>> Apr 17 14:44:28 localhost kernel: nfsd: last server has exited, flushing export cache
>> Apr 17 14:44:29 localhost kernel: NFSD: Using /var/lib/nfs/v4recovery as the NFSv4 state recovery directory
>> Apr 17 14:44:29 localhost kernel: NFSD: starting 90-second grace period
>> Apr 17 14:45:33 localhost mountd[24885]: Caught signal 15, un-registering and exiting.
>> Apr 17 14:45:33 localhost kernel: nfsd: last server has exited, flushing export cache
>> Apr 17 14:45:34 localhost kernel: NFSD: Using /var/lib/nfs/v4recovery as the NFSv4 state recovery directory
>> Apr 17 14:45:34 localhost kernel: NFSD: starting 90-second grace period
>> Apr 17 14:46:05 localhost mountd[24988]: Caught signal 15, un-registering and exiting.
>> Apr 17 14:46:05 localhost kernel: nfsd: last server has exited, flushing export cache
>> Apr 17 14:46:05 localhost kernel: NFSD: Using /var/lib/nfs/v4recovery as the NFSv4 state recovery directory
>> Apr 17 14:46:05 localhost kernel: NFSD: starting 90-second grace period
>> Apr 17 14:46:34 localhost mountd[25082]: Caught signal 15, un-registering and exiting.
>> Apr 17 14:46:34 localhost kernel: nfsd: last server has exited, flushing export cache
>> Apr 17 14:46:35 localhost kernel: NFSD: Using /var/lib/nfs/v4recovery as the NFSv4 state recovery directory
>> Apr 17 14:46:35 localhost kernel: NFSD: starting 90-second grace period
>> Apr 17 15:35:01 localhost mountd[25176]: Caught signal 15, un-registering and exiting.
>> Apr 17 15:35:02 localhost kernel: nfsd: last server has exited, flushing export cache
>> Apr 17 15:35:02 localhost kernel: ------------[ cut here ]------------
>> Apr 17 15:35:02 localhost kernel: WARNING: at lib/list_debug.c:26 __list_add+0x27/0x5c()
>> Apr 17 15:35:02 localhost kernel: Hardware name: Presario M2000 (PT365PA#AB2)      
>> Apr 17 15:35:02 localhost kernel: list_add corruption. next->prev should be prev (ef8fe958), but was ef8ff128. (next=ef8ff128).
>> Apr 17 15:35:02 localhost kernel: Modules linked in: fuse i915 drm i2c_algo_bit nfsd lockd nfs_acl auth_rpcgss exportfs sunrpc ipv6 p4_clockmod dm_multipath uinput snd_intel8x0m snd_intel8x0 snd_seq_dummy snd_ac97_codec ac97_bus snd_seq_oss snd_seq_midi_event snd_seq snd_seq_device snd_pcm_oss snd_mixer_oss snd_pcm snd_timer snd soundcore 8139cp firewire_ohci firewire_core snd_page_alloc tifm_7xx1 i2c_i801 iTCO_wdt 8139too tifm_core i2c_core yenta_socket crc_itu_t iTCO_vendor_support pcspkr mii rsrc_nonstatic wmi video output ata_generic pata_acpi [last unloaded: microcode]
>> Apr 17 15:35:02 localhost kernel: Pid: 25883, comm: lockd Tainted: G        W  2.6.30-rc2 #3
>> Apr 17 15:35:02 localhost kernel: Call Trace:
>> Apr 17 15:35:02 localhost kernel: [<c042d5b5>] warn_slowpath+0x71/0xa0
>> Apr 17 15:35:02 localhost kernel: [<c0422a96>] ? update_curr+0x11d/0x125
>> Apr 17 15:35:02 localhost kernel: [<c044b12d>] ? trace_hardirqs_on_caller+0x18/0x150
>> Apr 17 15:35:02 localhost kernel: [<c044b270>] ? trace_hardirqs_on+0xb/0xd
>> Apr 17 15:35:02 localhost kernel: [<c051c61a>] ? _raw_spin_lock+0x53/0xfa
>> Apr 17 15:35:02 localhost kernel: [<c051c89f>] __list_add+0x27/0x5c
>> Apr 17 15:35:02 localhost kernel: [<ef8f6daa>] locks_start_grace+0x22/0x30 [lockd]
>> Apr 17 15:35:02 localhost kernel: [<ef8f34da>] set_grace_period+0x39/0x53 [lockd]
>> Apr 17 15:35:02 localhost kernel: [<c06b8921>] ? lock_kernel+0x1c/0x28
>> Apr 17 15:35:02 localhost kernel: [<ef8f3558>] lockd+0x64/0x164 [lockd]
>> Apr 17 15:35:02 localhost kernel: [<c044b12d>] ? trace_hardirqs_on_caller+0x18/0x150
>> Apr 17 15:35:02 localhost kernel: [<c04227b0>] ? complete+0x34/0x3e
>> Apr 17 15:35:02 localhost kernel: [<ef8f34f4>] ? lockd+0x0/0x164 [lockd]
>> Apr 17 15:35:02 localhost kernel: [<ef8f34f4>] ? lockd+0x0/0x164 [lockd]
>> Apr 17 15:35:02 localhost kernel: [<c043dd42>] kthread+0x45/0x6b
>> Apr 17 15:35:02 localhost kernel: [<c043dcfd>] ? kthread+0x0/0x6b
>> Apr 17 15:35:02 localhost kernel: [<c0403c23>] kernel_thread_helper+0x7/0x10
>> Apr 17 15:35:02 localhost kernel: ---[ end trace fa484bd6d19ade8c ]---
>> Apr 17 15:35:02 localhost kernel: NFSD: Using /var/lib/nfs/v4recovery as the NFSv4 state recovery directory
>> Apr 17 15:35:02 localhost kernel: NFSD: starting 90-second grace period
>> Apr 17 15:55:22 localhost mountd[25895]: Caught signal 15, un-registering and exiting.
>> Apr 17 15:55:22 localhost kernel: nfsd: last server has exited, flushing export cache
>> Apr 17 15:55:23 localhost kernel: ------------[ cut here ]------------
>> Apr 17 15:55:23 localhost kernel: WARNING: at lib/list_debug.c:26 __list_add+0x27/0x5c()
>> Apr 17 15:55:23 localhost kernel: Hardware name: Presario M2000 (PT365PA#AB2)      
>> Apr 17 15:55:23 localhost kernel: list_add corruption. next->prev should be prev (ef8fe958), but was ef8ff128. (next=ef8ff128).
>> Apr 17 15:55:23 localhost kernel: Modules linked in: fuse i915 drm i2c_algo_bit nfsd lockd nfs_acl auth_rpcgss exportfs sunrpc ipv6 p4_clockmod dm_multipath uinput snd_intel8x0m snd_intel8x0 snd_seq_dummy snd_ac97_codec ac97_bus snd_seq_oss snd_seq_midi_event snd_seq snd_seq_device snd_pcm_oss snd_mixer_oss snd_pcm snd_timer snd soundcore 8139cp firewire_ohci firewire_core snd_page_alloc tifm_7xx1 i2c_i801 iTCO_wdt 8139too tifm_core i2c_core yenta_socket crc_itu_t iTCO_vendor_support pcspkr mii rsrc_nonstatic wmi video output ata_generic pata_acpi [last unloaded: microcode]
>> Apr 17 15:55:23 localhost kernel: Pid: 26230, comm: lockd Tainted: G        W  2.6.30-rc2 #3
>> Apr 17 15:55:23 localhost kernel: Call Trace:
>> Apr 17 15:55:23 localhost kernel: [<c042d5b5>] warn_slowpath+0x71/0xa0
>> Apr 17 15:55:23 localhost kernel: [<c0422a96>] ? update_curr+0x11d/0x125
>> Apr 17 15:55:23 localhost kernel: [<c044b12d>] ? trace_hardirqs_on_caller+0x18/0x150
>> Apr 17 15:55:23 localhost kernel: [<c044b270>] ? trace_hardirqs_on+0xb/0xd
>> Apr 17 15:55:23 localhost kernel: [<c051c61a>] ? _raw_spin_lock+0x53/0xfa
>> Apr 17 15:55:23 localhost kernel: [<c051c89f>] __list_add+0x27/0x5c
>> Apr 17 15:55:23 localhost kernel: [<ef8f6daa>] locks_start_grace+0x22/0x30 [lockd]
>> Apr 17 15:55:23 localhost kernel: [<ef8f34da>] set_grace_period+0x39/0x53 [lockd]
>> Apr 17 15:55:23 localhost kernel: [<c06b8921>] ? lock_kernel+0x1c/0x28
>> Apr 17 15:55:23 localhost kernel: [<ef8f3558>] lockd+0x64/0x164 [lockd]
>> Apr 17 15:55:23 localhost kernel: [<c044b12d>] ? trace_hardirqs_on_caller+0x18/0x150
>> Apr 17 15:55:23 localhost kernel: [<c04227b0>] ? complete+0x34/0x3e
>> Apr 17 15:55:23 localhost kernel: [<ef8f34f4>] ? lockd+0x0/0x164 [lockd]
>> Apr 17 15:55:23 localhost kernel: [<ef8f34f4>] ? lockd+0x0/0x164 [lockd]
>> Apr 17 15:55:23 localhost kernel: [<c043dd42>] kthread+0x45/0x6b
>> Apr 17 15:55:23 localhost kernel: [<c043dcfd>] ? kthread+0x0/0x6b
>> Apr 17 15:55:23 localhost kernel: [<c0403c23>] kernel_thread_helper+0x7/0x10
>> Apr 17 15:55:23 localhost kernel: ---[ end trace fa484bd6d19ade8d ]---
>> Apr 17 15:55:23 localhost kernel: NFSD: Using /var/lib/nfs/v4recovery as the NFSv4 state recovery directory
>> Apr 17 15:55:23 localhost kernel: NFSD: starting 90-second grace period
>> Apr 17 16:54:27 localhost mountd[26242]: Caught signal 15, un-registering and exiting.
>> Apr 17 16:54:27 localhost kernel: nfsd: last server has exited, flushing export cache
>> Apr 17 16:54:28 localhost kernel: ------------[ cut here ]------------
>> Apr 17 16:54:28 localhost kernel: WARNING: at lib/list_debug.c:26 __list_add+0x27/0x5c()
>> Apr 17 16:54:28 localhost kernel: Hardware name: Presario M2000 (PT365PA#AB2)      
>> Apr 17 16:54:28 localhost kernel: list_add corruption. next->prev should be prev (ef8fe958), but was ef8ff128. (next=ef8ff128).
>> Apr 17 16:54:28 localhost kernel: Modules linked in: fuse i915 drm i2c_algo_bit nfsd lockd nfs_acl auth_rpcgss exportfs sunrpc ipv6 p4_clockmod dm_multipath uinput snd_intel8x0m snd_intel8x0 snd_seq_dummy snd_ac97_codec ac97_bus snd_seq_oss snd_seq_midi_event snd_seq snd_seq_device snd_pcm_oss snd_mixer_oss snd_pcm snd_timer snd soundcore 8139cp firewire_ohci firewire_core snd_page_alloc tifm_7xx1 i2c_i801 iTCO_wdt 8139too tifm_core i2c_core yenta_socket crc_itu_t iTCO_vendor_support pcspkr mii rsrc_nonstatic wmi video output ata_generic pata_acpi [last unloaded: microcode]
>> Apr 17 16:54:28 localhost kernel: Pid: 27044, comm: lockd Tainted: G        W  2.6.30-rc2 #3
>> Apr 17 16:54:28 localhost kernel: Call Trace:
>> Apr 17 16:54:28 localhost kernel: [<c042d5b5>] warn_slowpath+0x71/0xa0
>> Apr 17 16:54:28 localhost kernel: [<c0422a96>] ? update_curr+0x11d/0x125
>> Apr 17 16:54:28 localhost kernel: [<c044b12d>] ? trace_hardirqs_on_caller+0x18/0x150
>> Apr 17 16:54:28 localhost kernel: [<c044b270>] ? trace_hardirqs_on+0xb/0xd
>> Apr 17 16:54:28 localhost kernel: [<c051c61a>] ? _raw_spin_lock+0x53/0xfa
>> Apr 17 16:54:28 localhost kernel: [<c051c89f>] __list_add+0x27/0x5c
>> Apr 17 16:54:28 localhost kernel: [<ef8f6daa>] locks_start_grace+0x22/0x30 [lockd]
>> Apr 17 16:54:28 localhost kernel: [<ef8f34da>] set_grace_period+0x39/0x53 [lockd]
>> Apr 17 16:54:28 localhost kernel: [<c06b8921>] ? lock_kernel+0x1c/0x28
>> Apr 17 16:54:28 localhost kernel: [<ef8f3558>] lockd+0x64/0x164 [lockd]
>> Apr 17 16:54:28 localhost kernel: [<c044b12d>] ? trace_hardirqs_on_caller+0x18/0x150
>> Apr 17 16:54:28 localhost kernel: [<c04227b0>] ? complete+0x34/0x3e
>> Apr 17 16:54:28 localhost kernel: [<ef8f34f4>] ? lockd+0x0/0x164 [lockd]
>> Apr 17 16:54:28 localhost kernel: [<ef8f34f4>] ? lockd+0x0/0x164 [lockd]
>> Apr 17 16:54:28 localhost kernel: [<c043dd42>] kthread+0x45/0x6b
>> Apr 17 16:54:28 localhost kernel: [<c043dcfd>] ? kthread+0x0/0x6b
>> Apr 17 16:54:28 localhost kernel: [<c0403c23>] kernel_thread_helper+0x7/0x10
>> Apr 17 16:54:28 localhost kernel: ---[ end trace fa484bd6d19ade8e ]---
>> Apr 17 16:54:28 localhost kernel: NFSD: Using /var/lib/nfs/v4recovery as the NFSv4 state recovery directory
>> Apr 17 16:54:28 localhost kernel: NFSD: starting 90-second grace period
>> Apr 17 16:59:55 localhost mountd[27056]: Caught signal 15, un-registering and exiting.
>> Apr 17 16:59:55 localhost kernel: nfsd: last server has exited, flushing export cache
>> Apr 17 16:59:56 localhost kernel: ------------[ cut here ]------------
>> Apr 17 16:59:56 localhost kernel: WARNING: at lib/list_debug.c:26 __list_add+0x27/0x5c()
>> Apr 17 16:59:56 localhost kernel: Hardware name: Presario M2000 (PT365PA#AB2)      
>> Apr 17 16:59:56 localhost kernel: list_add corruption. next->prev should be prev (ef8fe958), but was ef8ff128. (next=ef8ff128).
>> Apr 17 16:59:56 localhost kernel: Modules linked in: fuse i915 drm i2c_algo_bit nfsd lockd nfs_acl auth_rpcgss exportfs sunrpc ipv6 p4_clockmod dm_multipath uinput snd_intel8x0m snd_intel8x0 snd_seq_dummy snd_ac97_codec ac97_bus snd_seq_oss snd_seq_midi_event snd_seq snd_seq_device snd_pcm_oss snd_mixer_oss snd_pcm snd_timer snd soundcore 8139cp firewire_ohci firewire_core snd_page_alloc tifm_7xx1 i2c_i801 iTCO_wdt 8139too tifm_core i2c_core yenta_socket crc_itu_t iTCO_vendor_support pcspkr mii rsrc_nonstatic wmi video output ata_generic pata_acpi [last unloaded: microcode]
>> Apr 17 16:59:56 localhost kernel: Pid: 27197, comm: lockd Tainted: G        W  2.6.30-rc2 #3
>> Apr 17 16:59:56 localhost kernel: Call Trace:
>> Apr 17 16:59:56 localhost kernel: [<c042d5b5>] warn_slowpath+0x71/0xa0
>> Apr 17 16:59:56 localhost kernel: [<c0422a96>] ? update_curr+0x11d/0x125
>> Apr 17 16:59:56 localhost kernel: [<c044b12d>] ? trace_hardirqs_on_caller+0x18/0x150
>> Apr 17 16:59:56 localhost kernel: [<c044b270>] ? trace_hardirqs_on+0xb/0xd
>> Apr 17 16:59:56 localhost kernel: [<c051c61a>] ? _raw_spin_lock+0x53/0xfa
>> Apr 17 16:59:56 localhost kernel: [<c051c89f>] __list_add+0x27/0x5c
>> Apr 17 16:59:56 localhost kernel: [<ef8f6daa>] locks_start_grace+0x22/0x30 [lockd]
>> Apr 17 16:59:56 localhost kernel: [<ef8f34da>] set_grace_period+0x39/0x53 [lockd]
>> Apr 17 16:59:56 localhost kernel: [<c06b8921>] ? lock_kernel+0x1c/0x28
>> Apr 17 16:59:56 localhost kernel: [<ef8f3558>] lockd+0x64/0x164 [lockd]
>> Apr 17 16:59:56 localhost kernel: [<c044b12d>] ? trace_hardirqs_on_caller+0x18/0x150
>> Apr 17 16:59:56 localhost kernel: [<c04227b0>] ? complete+0x34/0x3e
>> Apr 17 16:59:56 localhost kernel: [<ef8f34f4>] ? lockd+0x0/0x164 [lockd]
>> Apr 17 16:59:56 localhost kernel: [<ef8f34f4>] ? lockd+0x0/0x164 [lockd]
>> Apr 17 16:59:56 localhost kernel: [<c043dd42>] kthread+0x45/0x6b
>> Apr 17 16:59:56 localhost kernel: [<c043dcfd>] ? kthread+0x0/0x6b
>> Apr 17 16:59:56 localhost kernel: [<c0403c23>] kernel_thread_helper+0x7/0x10
>> Apr 17 16:59:56 localhost kernel: ---[ end trace fa484bd6d19ade8f ]---
>> Apr 17 16:59:56 localhost kernel: NFSD: Using /var/lib/nfs/v4recovery as the NFSv4 state recovery directory
>> Apr 17 16:59:56 localhost kernel: NFSD: starting 90-second grace period
>> Apr 17 17:02:50 localhost mountd[27209]: Caught signal 15, un-registering and exiting.
>> Apr 17 17:02:50 localhost kernel: nfsd: last server has exited, flushing export cache
>> Apr 17 17:02:51 localhost kernel: ------------[ cut here ]------------
>> Apr 17 17:02:51 localhost kernel: WARNING: at lib/list_debug.c:26 __list_add+0x27/0x5c()
>> Apr 17 17:02:51 localhost kernel: Hardware name: Presario M2000 (PT365PA#AB2)      
>> Apr 17 17:02:51 localhost kernel: list_add corruption. next->prev should be prev (ef8fe958), but was ef8ff128. (next=ef8ff128).
>> Apr 17 17:02:51 localhost kernel: Modules linked in: fuse i915 drm i2c_algo_bit nfsd lockd nfs_acl auth_rpcgss exportfs sunrpc ipv6 p4_clockmod dm_multipath uinput snd_intel8x0m snd_intel8x0 snd_seq_dummy snd_ac97_codec ac97_bus snd_seq_oss snd_seq_midi_event snd_seq snd_seq_device snd_pcm_oss snd_mixer_oss snd_pcm snd_timer snd soundcore 8139cp firewire_ohci firewire_core snd_page_alloc tifm_7xx1 i2c_i801 iTCO_wdt 8139too tifm_core i2c_core yenta_socket crc_itu_t iTCO_vendor_support pcspkr mii rsrc_nonstatic wmi video output ata_generic pata_acpi [last unloaded: microcode]
>> Apr 17 17:02:51 localhost kernel: Pid: 27349, comm: lockd Tainted: G        W  2.6.30-rc2 #3
>> Apr 17 17:02:51 localhost kernel: Call Trace:
>> Apr 17 17:02:51 localhost kernel: [<c042d5b5>] warn_slowpath+0x71/0xa0
>> Apr 17 17:02:51 localhost kernel: [<c0422a96>] ? update_curr+0x11d/0x125
>> Apr 17 17:02:51 localhost kernel: [<c044b12d>] ? trace_hardirqs_on_caller+0x18/0x150
>> Apr 17 17:02:51 localhost kernel: [<c044b270>] ? trace_hardirqs_on+0xb/0xd
>> Apr 17 17:02:51 localhost kernel: [<c051c61a>] ? _raw_spin_lock+0x53/0xfa
>> Apr 17 17:02:51 localhost kernel: [<c051c89f>] __list_add+0x27/0x5c
>> Apr 17 17:02:51 localhost kernel: [<ef8f6daa>] locks_start_grace+0x22/0x30 [lockd]
>> Apr 17 17:02:51 localhost kernel: [<ef8f34da>] set_grace_period+0x39/0x53 [lockd]
>> Apr 17 17:02:51 localhost kernel: [<c06b8921>] ? lock_kernel+0x1c/0x28
>> Apr 17 17:02:51 localhost kernel: [<ef8f3558>] lockd+0x64/0x164 [lockd]
>> Apr 17 17:02:51 localhost kernel: [<c044b12d>] ? trace_hardirqs_on_caller+0x18/0x150
>> Apr 17 17:02:51 localhost kernel: [<c04227b0>] ? complete+0x34/0x3e
>> Apr 17 17:02:51 localhost kernel: [<ef8f34f4>] ? lockd+0x0/0x164 [lockd]
>> Apr 17 17:02:51 localhost kernel: [<ef8f34f4>] ? lockd+0x0/0x164 [lockd]
>> Apr 17 17:02:51 localhost kernel: [<c043dd42>] kthread+0x45/0x6b
>> Apr 17 17:02:51 localhost kernel: [<c043dcfd>] ? kthread+0x0/0x6b
>> Apr 17 17:02:51 localhost kernel: [<c0403c23>] kernel_thread_helper+0x7/0x10
>> Apr 17 17:02:51 localhost kernel: ---[ end trace fa484bd6d19ade90 ]---
>> Apr 17 17:02:51 localhost kernel: NFSD: Using /var/lib/nfs/v4recovery as the NFSv4 state recovery directory
>> Apr 17 17:02:51 localhost kernel: NFSD: starting 90-second grace period
>> Apr 17 17:08:09 localhost mountd[27361]: authenticated mount request from 10.167.141.101:695 for /tmp/nfs3 (/tmp/nfs3)
>>
>>> --b.
>>>
>>>>> --b.
>>>>>
>>>>> diff --git a/fs/lockd/svc.c b/fs/lockd/svc.c
>>>>> index abf8388..1a54ae1 100644
>>>>> --- a/fs/lockd/svc.c
>>>>> +++ b/fs/lockd/svc.c
>>>>> @@ -104,6 +104,16 @@ static void set_grace_period(void)
>>>>>  	schedule_delayed_work(&grace_period_end, grace_period);
>>>>>  }
>>>>>  
>>>>> +static void restart_grace(void)
>>>>> +{
>>>>> +	if (nlmsvc_ops) {
>>>>> +		cancel_delayed_work_sync(&grace_period_end);
>>>>> +		locks_end_grace(&lockd_manager);
>>>>> +		nlmsvc_invalidate_all();
>>>>> +		set_grace_period();
>>>>> +	}
>>>>> +}
>>>>> +
>>>>>  /*
>>>>>   * This is the lockd kernel thread
>>>>>   */
>>>>> @@ -149,10 +159,7 @@ lockd(void *vrqstp)
>>>>>  
>>>>>  		if (signalled()) {
>>>>>  			flush_signals(current);
>>>>> -			if (nlmsvc_ops) {
>>>>> -				nlmsvc_invalidate_all();
>>>>> -				set_grace_period();
>>>>> -			}
>>>>> +			restart_grace();
>>>>>  			continue;
>>>>>  		}
>>>>>  
>>>>>