From: Christoph Hellwig <hch@infradead.org>
To: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Cc: Christoph Hellwig <hch@infradead.org>, Jan Kara <jack@suse.cz>,
Dave Chinner <dchinner@redhat.com>,
linux-block@vger.kernel.org, Jens Axboe <axboe@kernel.dk>
Subject: Re: [syzbot] possible deadlock in blkdev_put (2)
Date: Tue, 30 Nov 2021 04:57:31 -0800 [thread overview]
Message-ID: <YaYfu0H2k0PSQL6W@infradead.org> (raw)
In-Reply-To: <baeeebb3-c04e-ce0a-cb1d-56eb4a7e1914@i-love.sakura.ne.jp>
On Mon, Nov 29, 2021 at 07:36:27PM +0900, Tetsuo Handa wrote:
> If the caller just want to call ioctl(LOOP_CTL_GET_FREE) followed by
> ioctl(LOOP_CONFIGURE), deferring __loop_clr_fd() would be fine.
>
> But the caller might want to unmount as soon as fput(filp) from __loop_clr_fd() completes.
> I think we need to wait for __loop_clr_fd() from lo_release() to complete.
Anything else could have a reference to this or other files as well.
So I can't see how deferring the clear to a different context can be
any kind of problem in practice.
next prev parent reply other threads:[~2021-11-30 12:57 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-27 7:10 [syzbot] possible deadlock in blkdev_put (2) syzbot
2021-11-27 11:27 ` Tetsuo Handa
2021-11-28 5:32 ` Tetsuo Handa
2021-11-28 7:42 ` Tetsuo Handa
2021-11-29 10:21 ` Christoph Hellwig
2021-11-29 10:36 ` Tetsuo Handa
2021-11-29 14:13 ` Tetsuo Handa
2021-11-30 12:57 ` Christoph Hellwig [this message]
2021-12-01 14:41 ` [PATCH] loop: make autoclear operation asynchronous Tetsuo Handa
2021-12-02 7:22 ` Christoph Hellwig
2021-12-02 11:03 ` Tetsuo Handa
2021-12-02 12:16 ` Jan Kara
2021-12-02 14:39 ` Tetsuo Handa
2021-12-02 18:05 ` Jan Kara
2021-12-03 6:50 ` Christoph Hellwig
2021-12-03 11:01 ` Tetsuo Handa
2021-12-08 9:56 ` Tetsuo Handa
2021-12-08 5:05 ` [syzbot] possible deadlock in blkdev_put (2) syzbot
2021-12-08 11:42 ` syzbot
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=YaYfu0H2k0PSQL6W@infradead.org \
--to=hch@infradead.org \
--cc=axboe@kernel.dk \
--cc=dchinner@redhat.com \
--cc=jack@suse.cz \
--cc=linux-block@vger.kernel.org \
--cc=penguin-kernel@i-love.sakura.ne.jp \
/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;
as well as URLs for NNTP newsgroup(s).