public inbox for [email protected]
 help / color / mirror / Atom feed
From: Jens Axboe <[email protected]>
To: Pavel Begunkov <[email protected]>, Hillf Danton <[email protected]>
Cc: [email protected], [email protected],
	[email protected], [email protected],
	[email protected],
	[email protected],
	Stefano Garzarella <[email protected]>,
	Kees Cook <[email protected]>
Subject: Re: [PATCH next] io_uring: fix task hung in io_uring_setup
Date: Mon, 7 Sep 2020 06:55:04 -0600	[thread overview]
Message-ID: <[email protected]> (raw)
In-Reply-To: <[email protected]>

On 9/7/20 2:50 AM, Pavel Begunkov wrote:
> On 03/09/2020 17:04, Jens Axboe wrote:
>> On 9/3/20 7:21 AM, Hillf Danton wrote:
>>>
>>> The smart syzbot found the following issue:
>>>
>>> INFO: task syz-executor047:6853 blocked for more than 143 seconds.
>>>       Not tainted 5.9.0-rc3-next-20200902-syzkaller #0
>>> "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
>>> task:syz-executor047 state:D stack:28104 pid: 6853 ppid:  6847 flags:0x00004000
>>> Call Trace:
>>>  context_switch kernel/sched/core.c:3777 [inline]
>>>  __schedule+0xea9/0x2230 kernel/sched/core.c:4526
>>>  schedule+0xd0/0x2a0 kernel/sched/core.c:4601
>>>  schedule_timeout+0x1d8/0x250 kernel/time/timer.c:1855
>>>  do_wait_for_common kernel/sched/completion.c:85 [inline]
>>>  __wait_for_common kernel/sched/completion.c:106 [inline]
>>>  wait_for_common kernel/sched/completion.c:117 [inline]
>>>  wait_for_completion+0x163/0x260 kernel/sched/completion.c:138
>>>  io_sq_thread_stop fs/io_uring.c:6906 [inline]
>>>  io_finish_async fs/io_uring.c:6920 [inline]
>>>  io_sq_offload_create fs/io_uring.c:7595 [inline]
>>>  io_uring_create fs/io_uring.c:8671 [inline]
>>>  io_uring_setup+0x1495/0x29a0 fs/io_uring.c:8744
>>>  do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
>>>  entry_SYSCALL_64_after_hwframe+0x44/0xa9
>>>
>>> because the sqo_thread kthread is created in io_sq_offload_create() without
>>> being waked up. Then in the error branch of that function we will wait for
>>> the sqo kthread that never runs. It's fixed by waking it up before waiting.
>>
>> Looks good - applied, thanks.
> 
> BTW, I don't see the patch itself, and it's neither in io_uring, block
> nor fs mailing lists. Hillf, could you please CC proper lists next time?

He did, but I'm guessing that vger didn't like the email for whatever
reason. Hillf, did you get an error back from vger when sending the patch?

-- 
Jens Axboe


  reply	other threads:[~2020-09-07 12:55 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <[email protected]>
2020-09-03 14:04 ` [PATCH next] io_uring: fix task hung in io_uring_setup Jens Axboe
2020-09-07  8:50   ` Pavel Begunkov
2020-09-07 12:55     ` Jens Axboe [this message]
     [not found]     ` <[email protected]>
2020-09-08 20:58       ` Pavel Begunkov
2020-09-08 23:34       ` Jens Axboe
     [not found]       ` <[email protected]>
2020-09-09 14:24         ` Jens Axboe
2020-09-07  8:43 ` Stefano Garzarella

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox