From: Christoph Hellwig <hch@lst.de>
To: Keith Busch <kbusch@kernel.org>
Cc: Bart Van Assche <bvanassche@acm.org>, Yu Kuai <yukuai@fnnas.com>,
axboe@kernel.dk, hch@lst.de, sagi@grimberg.me, sven@kernel.org,
j@jannau.net, linux-block@vger.kernel.org,
linux-nvme@lists.infradead.org, tj@kernel.org,
nilay@linux.ibm.com, ming.lei@redhat.com, neal@gompa.dev,
asahi@lists.linux.dev, linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH 4/4] blk-mq: use blk_queue_enter/exit to protect debugfs file creation
Date: Tue, 10 Feb 2026 16:41:50 +0100 [thread overview]
Message-ID: <20260210154150.GA2844@lst.de> (raw)
In-Reply-To: <aYoaWwI-sl5hK6s_@kbusch-mbp>
On Mon, Feb 09, 2026 at 10:33:15AM -0700, Keith Busch wrote:
> > This is not clear to me. Why are concurrent queue freezes not allowed
> > while debugfs attributes are created? I don't see any code in debugfs
> > that calls back into the block layer while creating debugfs attributes?
> > Did I perhaps overlook something?
>
> I had to look up the original commit that introduced the WARN,
> 65d466b629847. The commit message says "Creating new debugfs entries can
> trigger fs reclaim", so that must be the path that enters back into the
> blaock layer request_queue.
Another way to solves this would be to scope all the debugs action
as NOIO context.
next prev parent reply other threads:[~2026-02-10 15:41 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-02-09 8:29 [PATCH 0/4] blk-mq/nvme: fix debugfs creation with frozen queue Yu Kuai
2026-02-09 8:29 ` [PATCH 1/4] nvme-rdma: move blk_mq_update_nr_hw_queues after nvme_unfreeze Yu Kuai
2026-02-09 14:57 ` Christoph Hellwig
2026-02-11 7:21 ` Nilay Shroff
2026-02-09 8:29 ` [PATCH 2/4] nvme-tcp: " Yu Kuai
2026-02-09 14:57 ` Christoph Hellwig
2026-02-11 7:22 ` Nilay Shroff
2026-02-09 8:29 ` [PATCH 3/4] nvme-apple: " Yu Kuai
2026-02-09 14:58 ` Christoph Hellwig
2026-02-09 15:35 ` Keith Busch
2026-02-10 6:47 ` Yu Kuai
2026-02-10 15:09 ` Keith Busch
2026-02-10 15:41 ` Christoph Hellwig
2026-02-10 16:01 ` Keith Busch
2026-02-10 16:28 ` Daniel Wagner
2026-02-11 1:57 ` Yu Kuai
2026-02-11 12:57 ` Keith Busch
2026-02-10 8:10 ` Nilay Shroff
2026-02-10 15:12 ` Keith Busch
2026-02-11 7:23 ` Nilay Shroff
2026-02-09 8:29 ` [PATCH 4/4] blk-mq: use blk_queue_enter/exit to protect debugfs file creation Yu Kuai
2026-02-09 14:59 ` Christoph Hellwig
2026-02-09 16:40 ` Bart Van Assche
2026-02-09 17:33 ` Keith Busch
2026-02-09 17:51 ` Bart Van Assche
2026-02-10 6:59 ` Yu Kuai
2026-02-10 15:41 ` Christoph Hellwig [this message]
2026-02-11 7:20 ` Nilay Shroff
2026-02-11 8:06 ` Yu Kuai
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