From: Christoph Hellwig <hch@lst.de>
To: Nilay Shroff <nilay@linux.ibm.com>
Cc: linux-nvme@lists.infradead.org, hch@lst.de, kbusch@kernel.org,
sagi@grimberg.me, kch@nvidia.com, gjoyce@ibm.com
Subject: Re: [PATCH 1/1] nvme-loop: do not cancel I/O and admin tagset during ctrl reset/shutdown
Date: Fri, 20 Mar 2026 08:59:48 +0100 [thread overview]
Message-ID: <20260320075948.GA14895@lst.de> (raw)
In-Reply-To: <20260313113856.1366774-2-nilay@linux.ibm.com>
On Fri, Mar 13, 2026 at 05:08:48PM +0530, Nilay Shroff wrote:
> Cancelling the I/O and admin tagsets during nvme-loop controller reset
> or shutdown is unnecessary. The subsequent destruction of the I/O and
> admin queues already waits for all in-flight target operations to
> complete.
>
> Cancelling the tagsets first also opens a race window. After a request
> tag has been cancelled, a late completion from the target may still
> arrive before the queues are destroyed. In that case the completion path
> may access a request whose tag has already been cancelled or freed,
> which can lead to a kernel crash. Please see below the kernel crash
> encountered while running blktests nvme/040:
Looks good:
Reviewed-by: Christoph Hellwig <hch@lst.de>
next prev parent reply other threads:[~2026-03-20 7:59 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-03-13 11:38 [PATCH 0/1] nvme-loop: avoid cancelling/aborting I/O and admin tagset Nilay Shroff
2026-03-13 11:38 ` [PATCH 1/1] nvme-loop: do not cancel I/O and admin tagset during ctrl reset/shutdown Nilay Shroff
2026-03-20 7:59 ` Christoph Hellwig [this message]
2026-03-24 15:30 ` Keith Busch
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