From: Nilay Shroff <nilay@linux.ibm.com>
To: Keith Busch <kbusch@kernel.org>
Cc: Sagi Grimberg <sagi@grimberg.me>,
"linux-nvme@lists.infradead.org" <linux-nvme@lists.infradead.org>,
Christoph Hellwig <hch@lst.de>, "axboe@fb.com" <axboe@fb.com>,
Gregory Joyce <gjoyce@ibm.com>,
Srimannarayana Murthy Maram <msmurthy@imap.linux.ibm.com>
Subject: Re: [Bug Report] PCIe errinject and hot-unplug causes nvme driver hang
Date: Thu, 25 Apr 2024 19:19:42 +0530 [thread overview]
Message-ID: <43cf1234-5d86-402f-a690-95244cf920ff@linux.ibm.com> (raw)
In-Reply-To: <ZilDAv9y3dSzTPKb@kbusch-mbp.dhcp.thefacebook.com>
On 4/24/24 23:06, Keith Busch wrote:
> On Tue, Apr 23, 2024 at 03:22:46PM +0530, Nilay Shroff wrote:
>> I understand that we don't want to cancel pending IO from the nvme_remove()
>> unconditionally as if the disk is not physically hot-unplug then we still
>> want to wait for the in-flight IO to be finished. Also looking through
>> the above cases, I think that the nvme_timeout() might be the code path
>> from where we want to cancel in-flight/pending IO if controller is
>> in the terminal state (i.e. DELETING or DELETING_NOIO). Keeping this idea in
>> mind, I have worked out the below patch:
>>
>> diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
>> index 8e0bb9692685..e45a54d84649 100644
>> --- a/drivers/nvme/host/pci.c
>> +++ b/drivers/nvme/host/pci.c
>> @@ -1286,6 +1286,9 @@ static enum blk_eh_timer_return nvme_timeout(struct request *req)
>> u32 csts = readl(dev->bar + NVME_REG_CSTS);
>> u8 opcode;
>>
>> + if (nvme_state_terminal(&dev->ctrl))
>> + goto disable;
>> +
>> /* If PCI error recovery process is happening, we cannot reset or
>> * the recovery mechanism will surely fail.
>> */
>> @@ -1390,8 +1393,13 @@ static enum blk_eh_timer_return nvme_timeout(struct request *req)
>> return BLK_EH_RESET_TIMER;
>>
>> disable:
>> - if (!nvme_change_ctrl_state(&dev->ctrl, NVME_CTRL_RESETTING))
>> + if (!nvme_change_ctrl_state(&dev->ctrl, NVME_CTRL_RESETTING)) {
>> + if (nvme_state_terminal(&dev->ctrl)) {
>> + nvme_dev_disable(dev, false);
>> + nvme_sync_queues(&dev->ctrl);
>> + }
>> return BLK_EH_DONE;
>> + }
>>
>> nvme_dev_disable(dev, false);
>> if (nvme_try_sched_reset(&dev->ctrl))
>>
>> I have tested the above patch against all possible cases. Please let me know
>> if this looks good or if there are any further comments.
>
> This looks okay to me. Just a couple things:
>
> Set nvme_dev_disable's "shutdown" parameter to "true" since we're
> restarting the queues again from this state.
>
> Remove "nvme_sync_queues()". I think that would deadlock: sync_queues
> waits for the timeout work to complete, but your calling it within the
> timeout work, so this would have it wait for itself.
>
Thank you for reviewing the patch! And yes I agree with your suggestions.
I will make those changes and send a formal patch in another email.
Thanks,
--Nilay
prev parent reply other threads:[~2024-04-25 13:50 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-18 12:52 [Bug Report] PCIe errinject and hot-unplug causes nvme driver hang Nilay Shroff
2024-04-21 10:28 ` Sagi Grimberg
2024-04-21 16:53 ` Nilay Shroff
2024-04-21 16:56 ` Nilay Shroff
2024-04-22 13:00 ` Sagi Grimberg
2024-04-22 13:52 ` Keith Busch
2024-04-22 14:35 ` Keith Busch
2024-04-23 9:52 ` Nilay Shroff
2024-04-24 17:36 ` Keith Busch
2024-04-25 13:49 ` Nilay Shroff [this message]
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