All of lore.kernel.org
 help / color / mirror / Atom feed
From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
To: Christoph Hellwig <hch@infradead.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>,
	Jens Axboe <axboe@kernel.dk>,
	linux-block@vger.kernel.org,
	linux-fsdevel <linux-fsdevel@vger.kernel.org>
Subject: Re: [PATCH] block: add filemap_invalidate_lock_killable()
Date: Sat, 12 Feb 2022 17:28:09 +0900	[thread overview]
Message-ID: <cf0d2a39-3301-ecc6-12b5-e8e204812c71@I-love.SAKURA.ne.jp> (raw)
In-Reply-To: <8b2a61cb-4850-8bd7-3ff3-cebebefdb01b@I-love.SAKURA.ne.jp>

On 2022/01/04 22:26, Tetsuo Handa wrote:
> On 2022/01/04 16:14, Christoph Hellwig wrote:
>> On Mon, Jan 03, 2022 at 07:49:11PM +0900, Tetsuo Handa wrote:
>>> syzbot is reporting hung task at blkdev_fallocate() [1], for it can take
>>> minutes with mapping->invalidate_lock held. Since fallocate() has to accept
>>> size > MAX_RW_COUNT bytes, we can't predict how long it will take. Thus,
>>> mitigate this problem by using killable wait where possible.
>>
>> Well, but that also means we want all other users of the invalidate_lock
>> to be killable, as fallocate vs fallocate synchronization is probably
>> not the interesting case.
> 
> Right. But being responsive to SIGKILL is generally preferable.
> 
> syzbot (and other syzkaller based fuzzing) is reporting many hung task reports,
> but many of such reports are simply overstressing.
> 
> We can't use killable lock wait for release operation because it is a "void"
> function. But we can use killable lock wait for majority of operations which
> are not "void" functions. Use of killable lock wait where possible can improve
> situation.
> 

If there is no alternative, can we apply this patch?

  reply	other threads:[~2022-02-12  8:28 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-01-03  9:11 [syzbot] INFO: task hung in blkdev_fallocate syzbot
2022-01-03 10:49 ` [PATCH] block: add filemap_invalidate_lock_killable() Tetsuo Handa
2022-01-04  7:14   ` Christoph Hellwig
2022-01-04 13:26     ` Tetsuo Handa
2022-02-12  8:28       ` Tetsuo Handa [this message]
2022-02-14  8:17         ` Christoph Hellwig

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=cf0d2a39-3301-ecc6-12b5-e8e204812c71@I-love.SAKURA.ne.jp \
    --to=penguin-kernel@i-love.sakura.ne.jp \
    --cc=axboe@kernel.dk \
    --cc=hch@infradead.org \
    --cc=linux-block@vger.kernel.org \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=viro@zeniv.linux.org.uk \
    /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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.