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Date:   Fri, 4 Mar 2022 15:53:13 +0100
From:   Daniel Wagner <dwagner@suse.de>
To:     Ming Lei <ming.lei@redhat.com>
Cc:     linux-block@vger.kernel.org, linux-kernel@vger.kernel.org,
        Jens Axboe <axboe@kernel.dk>, Hannes Reinecke <hare@suse.de>
Subject: Re: [PATCH 2/2] block: hold queue lock while iterating in
 diskstats_show
Message-ID: <20220304145313.qnpv4lawl5vk4add@carbon.lan>
References: <20220120105248.117025-1-dwagner@suse.de>
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 <20220120140126.ntzvrcmczd7pph75@carbon.lan>
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On Thu, Jan 20, 2022 at 05:29:50PM +0100, Daniel Wagner wrote:
> On Thu, Jan 20, 2022 at 11:37:00PM +0800, Ming Lei wrote:
> > Seems more likely nvme recovery issue, tags is changed even though
> > ->q_usage_counter is grabbed in blk_mq_queue_tag_busy_iter(), which is
> > added in v4.19.
> > 
> > You may check dmesg log and see if there is any nvme error recovery info.
> 
> Thanks for the tip. It's likely that a recovery is running although
> there is no entry in the logs. At least I have an idea what could be the
> problem here.

FWIW, a846a8e6c9a5 ("blk-mq: don't free tags if the tag_set is used by
other device in queue initialztion") was missing our tree.