From: Christoph Hellwig <hch@lst.de>
To: Sagi Grimberg <sagi@grimberg.me>
Cc: Keith Busch <kbusch@kernel.org>, Christoph Hellwig <hch@lst.de>,
linux-nvme@lists.infradead.org,
James Smart <james.smart@broadcom.com>
Subject: Re: [PATCH v2 1/8] nvme-fabrics: allow to queue requests for live queues
Date: Fri, 14 Aug 2020 08:44:14 +0200 [thread overview]
Message-ID: <20200814064414.GA1719@lst.de> (raw)
In-Reply-To: <20200806191127.592062-2-sagi@grimberg.me>
On Thu, Aug 06, 2020 at 12:11:20PM -0700, Sagi Grimberg wrote:
> Right now we are failing requests based on the controller
> state (which is checked inline in nvmf_check_ready) however
> we should definitely accept requests if the queue is live.
>
> When entering controller reset, we transition the controller
> into NVME_CTRL_RESETTING, and then return BLK_STS_RESOURCE for
> non-mpath requests (have blk_noretry_request set).
>
> This is also the case for NVME_REQ_USER for the wrong reason.
> There shouldn't be any reason for us to reject this I/O in a
> controller reset. We do want to prevent passthru commands on
> the admin queue because we need the controller to fully initialize
> first before we let user passthru admin commands to be issued.
>
> In a non-mpath setup, this means that the requests will simply
> be requeued over and over forever not allowing the q_usage_counter
> to drop its final reference, causing controller reset to hang
> if running concurrently with heavy I/O.
Which will still happen with the admin queue user passthrough
commands with this patch, so I don't think it actually solves anything,
it just reduces the exposure a bit.
>
> While we are at it, remove the redundant NVME_CTRL_NEW case, which
> should never see any I/O as it must first transition to
> NVME_CTRL_CONNECTING.
That probablyly should be a separate patch.
> - if (nvme_is_fabrics(req->cmd) &&
> + if (blk_rq_is_passthrough(rq) && nvme_is_fabrics(req->cmd) &&
And this (make sure we don't access garbage in ->cmd for non-passthrough)
should probably be a separate fix as well.
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next prev parent reply other threads:[~2020-08-14 6:44 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-06 19:11 [PATCH v2 0/8] fix possible controller reset hangs in nvme-tcp/nvme-rdma Sagi Grimberg
2020-08-06 19:11 ` [PATCH v2 1/8] nvme-fabrics: allow to queue requests for live queues Sagi Grimberg
2020-08-14 6:44 ` Christoph Hellwig [this message]
2020-08-14 7:08 ` Sagi Grimberg
2020-08-14 7:22 ` Christoph Hellwig
2020-08-14 15:55 ` James Smart
2020-08-14 17:49 ` Sagi Grimberg
2020-08-06 19:11 ` [PATCH v2 2/8] nvme: have nvme_wait_freeze_timeout return if it timed out Sagi Grimberg
2020-08-14 6:45 ` Christoph Hellwig
2020-08-14 7:09 ` Sagi Grimberg
2020-08-06 19:11 ` [PATCH v2 3/8] nvme-tcp: serialize controller teardown double completion Sagi Grimberg
2020-08-06 19:11 ` [PATCH v2 4/8] nvme-tcp: fix timeout handler Sagi Grimberg
2020-08-06 19:11 ` [PATCH v2 5/8] nvme-tcp: fix reset hang if controller died in the middle of a reset Sagi Grimberg
2020-08-06 19:11 ` [PATCH v2 6/8] nvme-rdma: serialize controller teardown sequences Sagi Grimberg
2020-08-14 6:45 ` Christoph Hellwig
2020-08-14 21:12 ` James Smart
2020-08-19 0:35 ` Sagi Grimberg
2020-08-06 19:11 ` [PATCH v2 7/8] nvme-rdma: fix timeout handler Sagi Grimberg
2020-08-14 6:52 ` Christoph Hellwig
2020-08-14 7:14 ` Sagi Grimberg
2020-08-14 23:19 ` James Smart
2020-08-19 0:26 ` Sagi Grimberg
2020-08-14 23:27 ` James Smart
2020-08-14 23:30 ` James Smart
2020-08-19 0:39 ` Sagi Grimberg
2020-08-19 0:38 ` Sagi Grimberg
2020-08-06 19:11 ` [PATCH v2 8/8] nvme-rdma: fix reset hang if controller died in the middle of a reset Sagi Grimberg
2020-08-14 6:53 ` Christoph Hellwig
2020-08-11 22:16 ` [PATCH v2 0/8] fix possible controller reset hangs in nvme-tcp/nvme-rdma Sagi Grimberg
2020-08-13 15:39 ` Christoph Hellwig
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