From: Jan Kara <jack@suse.cz>
To: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Jan Kara <jack@suse.cz>,
util-linux@vger.kernel.org, linux-block@vger.kernel.org,
Karel Zak <kzak@redhat.com>
Subject: Re: Racy loop device reuse logic
Date: Wed, 19 Jan 2022 22:34:15 +0100 [thread overview]
Message-ID: <20220119213415.csieaktdqmshemiy@quack3.lan> (raw)
In-Reply-To: <28a360a3-b559-24ec-6c3d-3fe6e8302393@I-love.SAKURA.ne.jp>
On Wed 19-01-22 20:30:52, Tetsuo Handa wrote:
> I found a way to avoid this race by splitting lo_open() into two phases
> using task_work_add(). Christoph Hellwig is trying to take a look at
> https://lkml.kernel.org/r/f6b947d0-1047-66b3-0243-af5017c9ab55@I-love.SAKURA.ne.jp
> .
No, you have found a way to make the race window for mount(8) smaller. And
I still disagree with that kernel change because it is making kernel more
complex only to make the race window smaller. On another machine or with
different scheduling decisions, you can still hit this race. This problem
must be fixed in mount...
Honza
--
Jan Kara <jack@suse.com>
SUSE Labs, CR
next prev parent reply other threads:[~2022-01-19 21:34 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-01-13 15:47 Racy loop device reuse logic Jan Kara
2022-01-19 8:52 ` Jan Kara
2022-01-19 11:30 ` Tetsuo Handa
2022-01-19 21:34 ` Jan Kara [this message]
2022-01-20 8:50 ` Karel Zak
2022-01-20 10:09 ` Tetsuo Handa
2022-01-19 11:39 ` Karel Zak
2022-01-19 21:34 ` Jan Kara
2022-01-20 12:13 ` Jan Kara
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=20220119213415.csieaktdqmshemiy@quack3.lan \
--to=jack@suse.cz \
--cc=kzak@redhat.com \
--cc=linux-block@vger.kernel.org \
--cc=penguin-kernel@I-love.SAKURA.ne.jp \
--cc=util-linux@vger.kernel.org \
/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