From: Pavel Begunkov <asml.silence@gmail.com>
To: Dave Chinner <david@fromorbit.com>, viro@zeniv.linux.org.uk
Cc: linux-fsdevel@vger.kernel.org, Jens Axboe <axboe@kernel.dk>,
io-uring@vger.kernel.org
Subject: Re: [regression, v6.0-rc0, io-uring?] filesystem freeze hangs on sb_wait_write()
Date: Tue, 11 Oct 2022 02:10:11 +0100 [thread overview]
Message-ID: <8e45c8ee-fe38-75a9-04f4-cfa2d54baf88@gmail.com> (raw)
In-Reply-To: <20221011004025.GE2703033@dread.disaster.area>
On 10/11/22 01:40, Dave Chinner wrote:
[...]
> I note that there are changes to the the io_uring IO path and write
> IO end accounting in the io_uring stack that was merged, and there
> was no doubt about the success/failure of the reproducer at each
> step. Hence I think the bisect is good, and the problem is someone
> in the io-uring changes.
>
> Jens, over to you.
>
> The reproducer - generic/068 - is 100% reliable here, io_uring is
> being exercised by fsstress in the background whilst the filesystem
> is being frozen and thawed repeatedly. Some path in the io-uring
> code has an unbalanced sb_start_write()/sb_end_write() pair by the
> look of it....
A quick guess, it's probably
b000145e99078 ("io_uring/rw: defer fsnotify calls to task context")
From a quick look, it removes kiocb_end_write() -> sb_end_write()
from kiocb_done(), which is a kind of buffered rw completion path.
--
Pavel Begunkov
next prev parent reply other threads:[~2022-10-11 1:16 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-10 5:03 [regression, v6.0-rc0] filesystem freeze hangs on sb_wait_write() Dave Chinner
2022-10-11 0:40 ` [regression, v6.0-rc0, io-uring?] " Dave Chinner
2022-10-11 1:10 ` Pavel Begunkov [this message]
2022-10-11 2:01 ` Jens Axboe
2022-10-11 2:10 ` Pavel Begunkov
2022-10-11 2:54 ` Jens Axboe
2022-10-11 14:18 ` Jens Axboe
2022-10-11 14:39 ` Pavel Begunkov
2022-10-11 14:47 ` Jens Axboe
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