From: Chao Leng <lengchao@huawei.com>
To: Sagi Grimberg <sagi@grimberg.me>,
"Meneghini, John" <John.Meneghini@netapp.com>,
Keith Busch <kbusch@kernel.org>
Cc: Christoph Hellwig <hch@infradead.org>,
"linux-nvme@lists.infradead.org" <linux-nvme@lists.infradead.org>,
Hannes de <hare@suse.de>, Ewan Milne <emilne@redhat.com>
Subject: Re: [PATCH] nvme-core: fix io interrupt when work with dm-multipah
Date: Fri, 7 Aug 2020 10:28:02 +0800 [thread overview]
Message-ID: <57d8aacb-b479-3bca-3331-ec3b875cddcb@huawei.com> (raw)
In-Reply-To: <9d641d7d-8b3f-759b-afa5-1e5d4be0ff82@grimberg.me>
On 2020/8/7 8:03, Sagi Grimberg wrote:
>> I think the problem here is that the current BLK_STS and FAST_FAIL mechanisms
>> were designed support legacy protocols like SCSI. They assume that all retry behavior is
>> controlled by other components in the stack. NVMe is presenting new protocol features
>> and semantics which probably can't be effectively supported by those legacy BLK_STS
>> and FAST_FAIL mechanisms without passing more information up the stack.
>
> Not sure how generic this new blk status would be.. It would probably
> make a lot more sense of there are other consumers for such a status
> code.
>
> Maybe we could set it to BLK_STS_TIMEOUT with a big fat comment for why
> we are doing this...
Introduce a new BLK_STS error maybe a good choice, but is not friendly
to forward compatibility.
Now we have 3 choice:BLK_STS_TIMEOUT, BLK_STS_RESOURCE or BLK_STS_IOERR
by default. DM-multipath will fail path and then fail over to retry.
The difference is BLK_STS_RESOURCE will delay 100ms to retry,
BLK_STS_TIMEOUT and BLK_STS_IOERR will retry immediatly.
Now there is no perfect choice, but we have to choose one. I suggest
keep default, translate NVME_SC_CMD_INTERRUPTED to BLK_STS_IOERR.
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prev parent reply other threads:[~2020-08-07 2:28 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
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 [this message]
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