Re: Userspace locks at f2fs_issue_flush kernel call, hard reset necessary

[Chao Yu <chao@kernel.org>]

Hi Marcelo,

On 2017/10/13 12:19, Marcelo "Marc" Ranolfi wrote:
> Hello Chao,
> 
> I was holding for a while and taking care of other things, but now
> since I upgraded to kernel v4.13 (in fact I jumped to 4.13.3), I seem
> to be no longer affected by this problem.
> 
> My system has been running fine for over two weeks.

Good to hear about that. ;)

> 
> 
> I appreciate your help in this matter. Should I experience it once
> more, I'll ping you again.

No problem, I will keep an eye on this issue. :)

Thanks,

> 
> Thanks!
> 
> On Wed, Sep 13, 2017 at 11:22 PM, Chao Yu <yuchao0@huawei.com> wrote:
>> Hi Marcelo,
>>
>> Please add "f2fs: show flush list status in sysfs" first in your repo.
>>
>> And please try:
>> 1. mount without flush_merge option and do the test to see whether it is caused
>> by issue of the feature or lower block layer.
>>
>> For disabling the feature:
>> mount -o noflush_merge
>>
>> 2. do test with last codes in dev-test branch.
>>
>> If the problem is still there, please dump info with:
>> echo l > /proc/sysrq-trigger
>> echo w > /proc/sysrq-trigger
>> dmesg
>> cat /sys/kernel/debug/f2fs/status
>>
>> Thanks,
>>
>> On 2017/9/1 12:54, Marcelo "Marc" Ranolfi wrote:
>>> Hi,
>>>
>>> no problem at all.
>>>
>>> No, I never did ro remount before it happened. In fact its been a long
>>> while since I used ro.
>>>
>>>
>>> Regards
>>>
>>> On Thu, Aug 31, 2017 at 8:01 AM, Chao Yu <yuchao0@huawei.com> wrote:
>>>> Hi Marcelo,
>>>>
>>>> Sorry for the delay, :(
>>>>
>>>> I'd like ask, any possible that we did ro remount before the problem happened?
>>>>
>>>> Thanks,
>>>>
>>>> On 2017/8/24 1:26, Marcelo "Marc" Ranolfi wrote:
>>>>> Chao,
>>>>>
>>>>> I just had the same problem, with kernel 4.12.8 with patch _f2fs: fix
>>>>> out-of-order execution in f2fs_issue_flush_.
>>>>>
>>>>> On Tue, Aug 22, 2017 at 2:00 PM, Marcelo "Marc" Ranolfi
>>>>> <marc.2377@gmail.com> wrote:
>>>>>> Hi Chao
>>>>>>
>>>>>> I'm testing the kernel with your patch since last night. Will give new
>>>>>> feedback a couple of days/weeks about how it goes.
>>>>>>
>>>>>>
>>>>>> Thank you.
>>>>>>
>>>>>>
>>>>>>
>>>>>> On Mon, Aug 21, 2017 at 11:58 AM, Chao Yu <chao@kernel.org> wrote:
>>>>>>> Hi Marcelo,
>>>>>>>
>>>>>>> Thanks for the report!
>>>>>>>
>>>>>>> Would you have a try with below patch?
>>>>>>>
>>>>>>> f2fs: fix out-of-order execution in f2fs_issue_flush
>>>>>>>
>>>>>>> Thanks,
>>>>>>>
>>>>>>> On 2017/8/16 15:24, Marcelo "Marc" Ranolfi wrote:
>>>>>>>> Just wanted to let you all know that this is still an issue, even with
>>>>>>>> the 4.12.7 kernel.
>>>>>>>>
>>>>>>>> The two most affected applications are qemu-system-x86_64 and totem.
>>>>>>>>
>>>>>>>> On Wed, Aug 9, 2017 at 3:04 AM, Marcelo "Marc" Ranolfi
>>>>>>>> <marc.2377@gmail.com> wrote:
>>>>>>>>> What follows is a bug report.
>>>>>>>>>
>>>>>>>>> I've been experiencing system lockups somewhat randomly. Sometimes an
>>>>>>>>> application freezes, and when I go check its properties, it says the
>>>>>>>>> process' Wait Channel is _f2fs_issue_flush_.
>>>>>>>>>
>>>>>>>>> Sometimes it's the qemu process (which I use via libvirt), other times
>>>>>>>>> it's Firefox, or Gnome Videos (totem) and it happened to Nemo once as
>>>>>>>>> well. I have screenshots if necessary.
>>>>>>>>>
>>>>>>>>> I've been tracking this with screenshots, and it's happenning every 4
>>>>>>>>> days - on average.
>>>>>>>>>
>>>>>>>>> When this happens, the process stays unresponsive no matter what. I tried:
>>>>>>>>>
>>>>>>>>> - Restarting swap
>>>>>>>>> - Restarting the Display Manager
>>>>>>>>> - Graceful shutdown / reboot - takes forever, doesn't work
>>>>>>>>> - Shutdown -k and unmounting filesystems from command line - root
>>>>>>>>> can't be unmounted unless -l used, no solution
>>>>>>>>>
>>>>>>>>> The only working solution is to reset the machine via power button or
>>>>>>>>> #reboot -f.
>>>>>>>>>
>>>>>>>>> I have:
>>>>>>>>>
>>>>>>>>> - Kingston SV300S37A120G - hardware is fine, I have other OS / filesystems on it
>>>>>>>>> - f2fs filesystem in a 40 GB partition, GPT
>>>>>>>>> - kernel 4.12.4 with systemd 234.11 - typical up-to-date Arch Linux setup.
>>>>>>>>>
>>>>>>>>> You gentlemen let me know if I provide more help.
>>>>>>>>>
>>>>>>>>> Best,
>>>>>>>>> Marc
>>>>>>>>
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>>>>>>>>
>>>>>
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>>>>>
>>>>>
>>>>
>>>
>>> .
>>>
>>

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