From: Chao Leng <lengchao@huawei.com>
To: Hannes Reinecke <hare@suse.de>, Christoph Hellwig <hch@lst.de>
Cc: Keith Busch <keith.busch@wdc.com>,
Daniel Wagner <dwagner@suse.de>,
linux-nvme@lists.infradead.org, Sagi Grimberg <sagi@grimberg.me>
Subject: Re: [PATCH 0/2] nvme: sanitize KATO handling
Date: Wed, 24 Feb 2021 15:20:57 +0800 [thread overview]
Message-ID: <1834a11c-c472-e14f-ece3-a96ec2ced044@huawei.com> (raw)
In-Reply-To: <06e3b90a-719e-9561-5c63-67dac0a782e1@suse.de>
On 2021/2/24 15:06, Hannes Reinecke wrote:
> On 2/24/21 7:42 AM, Chao Leng wrote:
>>
>>
>> On 2021/2/23 20:07, Hannes Reinecke wrote:
>>> Hi all,
>>>
>>> one of our customer had been running into a deadlock trying to terminate
>>> outstanding KATO commands during reset.
>>> Looking closer at it, I found that we never actually _track_ if a KATO
>>> command is submitted, so we might happily be sending several KATO commands
>>> to the same controller simultaneously.
>> Can you explain how can send KATO commands simultaneously?
>
> Sure.
> Call nvme_start_keep_alive() on a dead connection.
> Just _after_ the KATO request has been sent,
> call nvme_start_keep_alive() again.
Call nvme_start_keep_alive() again? why?
Now just nvme_start_ctrl call nvme_start_keep_alive().
The ka_work will be canceled sync before start reconnection.
Did I miss something?
>
> You now have an expired KATO command, and the new KATO command, both are active and sent to the controller.
>
> Cheers,
>
> Hannes
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next prev parent reply other threads:[~2021-02-24 7:21 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-23 12:07 [PATCH 0/2] nvme: sanitize KATO handling Hannes Reinecke
2021-02-23 12:07 ` [PATCH 1/2] nvme: fixup kato deadlock Hannes Reinecke
2021-02-24 16:22 ` Christoph Hellwig
2021-02-23 12:07 ` [PATCH 2/2] nvme: sanitize KATO setting Hannes Reinecke
2021-02-24 16:23 ` Christoph Hellwig
2021-02-24 6:42 ` [PATCH 0/2] nvme: sanitize KATO handling Chao Leng
2021-02-24 7:06 ` Hannes Reinecke
2021-02-24 7:20 ` Chao Leng [this message]
2021-02-24 7:27 ` Chao Leng
2021-02-24 7:59 ` Hannes Reinecke
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