LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
To: Ming Lei <tom.leiming@gmail.com>, Ming Lei <ming.lei@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>,
	Bart Van Assche <Bart.VanAssche@wdc.com>,
	Dmitry Vyukov <dvyukov@google.com>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	linux-block <linux-block@vger.kernel.org>,
	Johannes Thumshirn <jthumshirn@suse.de>,
	alan.christopher.jenkins@gmail.com,
	syzbot+c4f9cebf9d651f6e54de@syzkaller.appspotmail.com,
	"Martin K. Petersen" <martin.petersen@oracle.com>,
	Dan Williams <dan.j.williams@intel.com>,
	Christoph Hellwig <hch@lst.de>,
	Oleksandr Natalenko <oleksandr@natalenko.name>,
	martin@lichtvoll.de, Hannes Reinecke <hare@suse.com>,
	syzkaller-bugs@googlegroups.com,
	Ross Zwisler <ross.zwisler@linux.intel.com>,
	Keith Busch <keith.busch@intel.com>,
	"open list:EXT4 FILE SYSTEM" <linux-ext4@vger.kernel.org>
Subject: Re: INFO: task hung in blk_queue_enter
Date: Thu, 7 Jun 2018 22:19:06 +0900	[thread overview]
Message-ID: <927ef9f9-4f4d-185e-b86f-10bd18fa92d4@i-love.sakura.ne.jp> (raw)
In-Reply-To: <CACVXFVNcJ+tC6RUT+JUA3iw+STB+q4P_u+AvoOSrt04zEw8TZA@mail.gmail.com>

On 2018/06/07 12:29, Ming Lei wrote:
>> The vfs_fsync() isn't necessary in loop_update_dio() since both
>> generic_file_write_iter() and generic_file_read_iter() can handle
>> buffered io vs dio well.
>>
>> I will send one patch to remove the vfs_sync() later.
> 
> Hi Tetsuo,
> 
> The issue might be fixed by removing this vfs_sync(), but I'd like to
> understand the idea behind since vfs_sync() shouldn't have caused
> any IO to this loop queue.
> 
> I also tried to do the test via the following c syzbot, but can't reproduce
> it yet after running it for several hours.
> 
> https://syzkaller.appspot.com/x/repro.c?id=4727023951937536
> 
> Could you share us how you reproduce it?

I just reported that syzbot started hitting vfs_sync() case.
I haven't succeeded reproducing vfs_sync() case in my environment.

But in general, I modify "any reproducer provided by syzbot that loops
forever" to call exit() if open() etc. failed, for continuing the loop
unlikely helps after hitting "Too many open files" error.

   res = syscall(__NR_memfd_create, 0x200002c0, 0);
   if (res != -1)
     r[1] = res;
+  else
+    exit(1);

Thus, I restart the reproducer in a loop from shell
rather than keep running for hours.

   while :; do echo -n .; ./a.out; done

  reply	other threads:[~2018-06-07 13:20 UTC|newest]

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-04-28 11:24 syzbot
2018-05-15 11:45 ` Tetsuo Handa
2018-05-16 13:05   ` Tetsuo Handa
2018-05-16 14:56     ` Bart Van Assche
2018-05-16 15:16       ` Dmitry Vyukov
2018-05-16 15:37         ` Bart Van Assche
2018-05-21 21:52           ` Tetsuo Handa
2018-05-22 11:20             ` Tetsuo Handa
2018-06-01 10:10               ` Tetsuo Handa
2018-06-01 17:52                 ` Jens Axboe
2018-06-01 23:49                   ` Ming Lei
2018-06-02  0:49                     ` Jens Axboe
2018-06-02  0:56                       ` Jens Axboe
2018-06-02  2:36                       ` Ming Lei
2018-06-02  4:31                         ` Jens Axboe
2018-06-02  4:54                           ` Ming Lei
2018-06-02  8:07                             ` Martin Steigerwald
2018-06-02 13:48                             ` Jens Axboe
2018-06-05  0:27                   ` Tetsuo Handa
2018-06-05  0:41                     ` Ming Lei
2018-06-07  3:29                       ` Ming Lei
2018-06-07 13:19                         ` Tetsuo Handa [this message]
2018-06-04 11:46                 ` Dmitry Vyukov
2018-06-04 13:13                   ` Tetsuo Handa
2018-05-16 17:33     ` Alan Jenkins

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 \
    --in-reply-to=927ef9f9-4f4d-185e-b86f-10bd18fa92d4@i-love.sakura.ne.jp \
    --to=penguin-kernel@i-love.sakura.ne.jp \
    --cc=Bart.VanAssche@wdc.com \
    --cc=alan.christopher.jenkins@gmail.com \
    --cc=axboe@kernel.dk \
    --cc=dan.j.williams@intel.com \
    --cc=dvyukov@google.com \
    --cc=hare@suse.com \
    --cc=hch@lst.de \
    --cc=jthumshirn@suse.de \
    --cc=keith.busch@intel.com \
    --cc=linux-block@vger.kernel.org \
    --cc=linux-ext4@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=martin.petersen@oracle.com \
    --cc=martin@lichtvoll.de \
    --cc=ming.lei@redhat.com \
    --cc=oleksandr@natalenko.name \
    --cc=ross.zwisler@linux.intel.com \
    --cc=syzbot+c4f9cebf9d651f6e54de@syzkaller.appspotmail.com \
    --cc=syzkaller-bugs@googlegroups.com \
    --cc=tom.leiming@gmail.com \
    --subject='Re: INFO: task hung in blk_queue_enter' \
    /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

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).