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Date:   Wed, 2 Jun 2021 14:47:16 +0800
From:   Ming Lei <ming.lei@redhat.com>
To:     Hannes Reinecke <hare@suse.de>
Cc:     Jens Axboe <axboe@kernel.dk>, Christoph Hellwig <hch@lst.de>,
        linux-block@vger.kernel.org,
        Linux Kernel Mailinglist <linux-kernel@vger.kernel.org>
Subject: Re: [PATCHv2] block/genhd: use atomic_t for disk_event->block
Message-ID: <YLcpdKnt28vS6waI@T590>
References: <20210602062015.33605-1-hare@suse.de>
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On Wed, Jun 02, 2021 at 08:20:15AM +0200, Hannes Reinecke wrote:
> __disk_unblock_events() will call queue_delayed_work() with a '0' argument
> under a spin lock. This might cause the queue_work item to be executed
> immediately, and run into a deadlock in disk_check_events() waiting for
> the lock to be released.

The above commit log isn't correct, and the current usage shouldn't cause such
deadlock, so can you root cause the task hang report[1] on 5.3.18?

[1] https://lore.kernel.org/linux-block/73783f6f-a3ec-907f-ea19-966e9d1457dc@suse.de/T/#mcde381522bdb95740e04ced555ec017a25c993cc

Thanks,
Ming