From: Christoph Hellwig <hch@lst.de>
To: Bart Van Assche <bvanassche@acm.org>
Cc: Jens Axboe <axboe@kernel.dk>,
linux-block@vger.kernel.org, Christoph Hellwig <hch@lst.de>,
Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>,
Nilay Shroff <nilay@linux.ibm.com>,
Edward Adam Davis <eadavis@qq.com>,
Dave Kleikamp <shaggy@kernel.org>,
jfs-discussion@lists.sourceforge.net
Subject: Re: [PATCH v6] loop: Wait for I/O completion in __loop_clr_fd()
Date: Wed, 7 Oct 2026 15:08:51 +0200 [thread overview]
Message-ID: <20261007130851.GA30117@lst.de> (raw)
In-Reply-To: <fb1e0f16346994e32b479e4be596436b2a614b03.1791234123.git.bvanassche@acm.org>
On Mon, Oct 05, 2026 at 02:06:02PM -0700, Bart Van Assche wrote:
> From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
>
> Syzbot reports a NULL pointer dereference in lo_rw_aio(). This crash
> probably happens because commit b15e4310633f ("jfs: Set the lbmDONE flag at
> the end of lbmIODone"), merged in the 7.1 merge window, lets the JFS log
> code report a write as finished while it is still in flight. JFS then tears
> down and releases the loop device with that write still sitting in the loop
> workqueue.
Why do we go offtrack messing with loop instead of investigating the
file system misbehavior?
> Although the root cause is in JFS, improve the loop driver by waiting in
> __loop_clr_fd() for ongoing I/O. Release &disk->open_mutex temporarily
> because otherwise a deadlock would be triggered.
We can't just drop the held lock.
next prev parent reply other threads:[~2026-10-07 13:09 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-10-05 21:06 [PATCH v6] loop: Wait for I/O completion in __loop_clr_fd() Bart Van Assche
2026-10-06 12:01 ` Tetsuo Handa
2026-10-06 17:15 ` Bart Van Assche
2026-10-07 13:08 ` Christoph Hellwig [this message]
2026-10-07 13:35 ` Tetsuo Handa
2026-10-11 10:37 ` [PATCH] loop: Detect write requests that failed to wait for completion Tetsuo Handa
2026-10-11 11:29 ` [PATCH v2] " Tetsuo Handa
2026-10-11 13:26 ` [PATCH v3] " Tetsuo Handa
2026-10-11 19:24 ` [syzbot ci] " syzbot ci
2026-10-12 8:26 ` [PATCH] block: Wait for inflight requests in bdev_release() Tetsuo Handa
2026-10-12 11:39 ` Tetsuo Handa
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