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 \
    --subject='Re: [PATCH] block: add filemap_invalidate_lock_killable()' \
    /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 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.