From: Christoph Hellwig <hch@lst.de>
To: Chao Leng <lengchao@huawei.com>
Cc: kbusch@kernel.org, axboe@fb.com, Christoph Hellwig <hch@lst.de>,
linux-nvme@lists.infradead.org, sagi@grimberg.me
Subject: Re: [PATCH] nvme-core: fix io interrupt when work with dm-multipah
Date: Wed, 29 Jul 2020 07:59:03 +0200 [thread overview]
Message-ID: <20200729055903.GC31113@lst.de> (raw)
In-Reply-To: <6df01884-5498-0809-b358-0c9f7d775a73@huawei.com>
On Wed, Jul 29, 2020 at 10:54:29AM +0800, Chao Leng wrote:
>
>
> On 2020/7/28 19:19, Christoph Hellwig wrote:
>> On Mon, Jul 27, 2020 at 01:58:18PM +0800, Chao Leng wrote:
>>> The protocol NVM-Express-1.4 define:
>>> Command Interrupted: Command processing was interrupted and the
>>> controller is unable to successfully complete the command. The host
>>> should retry the command. If this status code is returned, then
>>> the controller shall clear the Do Not Retry bit to ‘0’ in the Status
>>> field of the CQE (refer to Figure 124). The controller shall not return
>>> this status code unless the host has set the Advanced Command Retry
>>> Enable (ACRE) field to 1h in the Host Behavior Support feature(refer to
>>> section 5.21.1.22).
>>>
>>> According the protocol define, NVME_SC_CMD_INTERRUPTED need retry.
>>> The error code NVME_SC_CMD_INTERRUPTED should not translate to
>>> BLK_STS_TARGET, because if the error code translate to BLK_STS_TARGET,
>>> dm-multipah will return error to application. So if target return error
>>> code NVME_SC_CMD_INTERRUPTED, io will interrupt. NVME_SC_CMD_INTERRUPTED
>>> should translate to BLK_STS_IOERR by default, dm-multipath will fail
>>> over to other path retry the io.
>>
>> IOERR still seems wrong, though.
>> .
>
> BLK_STS_TARGET means target has critical error. NVME_SC_CMD_INTERRUPTED
> just means target need retry io. It is not suitable to translate
> NVME_SC_CMD_INTERRUPTED to BLK_STS_TARGET. Maybe translate to
> BLK_STS_IOERR is also not suitable, we should translate
> NVME_SC_CMD_INTERRUPTED to BLK_STS_AGAIN.
> We can do like this:
BLK_STS_AGAIN is a bad choice as we use it for calls that block when
the callers asked for non-blocking submission. I'm really not sure
we want to change anything here - the error definition clearly states
it is not a failure but a request to retry later.
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next prev parent reply other threads:[~2020-07-29 5:59 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-27 5:58 [PATCH] nvme-core: fix io interrupt when work with dm-multipah Chao Leng
2020-07-28 11:19 ` Christoph Hellwig
2020-07-29 2:54 ` Chao Leng
2020-07-29 5:59 ` Christoph Hellwig [this message]
2020-07-30 1:49 ` Chao Leng
2020-08-05 6:40 ` Chao Leng
2020-08-05 15:29 ` Keith Busch
2020-08-06 5:52 ` Chao Leng
2020-08-06 14:26 ` Keith Busch
2020-08-06 15:59 ` Meneghini, John
2020-08-06 16:17 ` Meneghini, John
2020-08-06 18:40 ` Mike Snitzer
2020-08-06 19:19 ` [PATCH] nvme: restore use of blk_path_error() in nvme_complete_rq() Mike Snitzer
2020-08-06 22:42 ` Meneghini, John
2020-08-07 0:07 ` Mike Snitzer
2020-08-07 1:21 ` Sagi Grimberg
2020-08-07 4:50 ` Mike Snitzer
2020-08-07 23:35 ` Sagi Grimberg
2020-08-08 21:08 ` Meneghini, John
2020-08-08 21:11 ` Meneghini, John
2020-08-10 14:48 ` Mike Snitzer
2020-08-11 12:54 ` Meneghini, John
2020-08-10 8:10 ` Chao Leng
2020-08-11 12:36 ` Meneghini, John
2020-08-12 7:51 ` Chao Leng
2020-08-10 14:36 ` Mike Snitzer
2020-08-10 17:22 ` [PATCH] nvme: explicitly use normal NVMe error handling when appropriate Mike Snitzer
2020-08-11 3:32 ` Chao Leng
2020-08-11 4:20 ` Mike Snitzer
2020-08-11 6:17 ` Chao Leng
2020-08-11 14:12 ` Mike Snitzer
2020-08-13 14:48 ` [RESEND PATCH] " Mike Snitzer
2020-08-13 15:29 ` Meneghini, John
2020-08-13 15:43 ` Mike Snitzer
2020-08-13 15:59 ` Meneghini, John
2020-08-13 15:36 ` Christoph Hellwig
2020-08-13 17:47 ` Mike Snitzer
2020-08-13 18:43 ` Christoph Hellwig
2020-08-13 19:03 ` Mike Snitzer
2020-08-14 4:26 ` Meneghini, John
2020-08-14 6:53 ` Sagi Grimberg
2020-08-14 6:55 ` Christoph Hellwig
2020-08-14 7:02 ` Sagi Grimberg
2020-08-14 3:23 ` Meneghini, John
2020-08-07 0:44 ` [PATCH] nvme: restore use of blk_path_error() in nvme_complete_rq() Sagi Grimberg
2020-08-10 12:43 ` Christoph Hellwig
2020-08-10 15:06 ` Mike Snitzer
2020-08-11 3:45 ` [PATCH] " Chao Leng
2020-08-07 0:03 ` [PATCH] nvme-core: fix io interrupt when work with dm-multipah Sagi Grimberg
2020-08-07 2:28 ` Chao Leng
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