From: "Nadolski, Edmund" <edmund.nadolski@intel.com>
To: Keith Busch <kbusch@kernel.org>,
Edmund Nadolski <edmund.nadolski@intel.com>
Cc: linux-nvme@lists.infradead.org
Subject: Re: [PATCH] nvme: clear stale nvmeq->tags after tagset free
Date: Thu, 16 Jan 2020 15:06:40 -0700 [thread overview]
Message-ID: <0ff9ee57-0211-0170-7c58-a6c5d9354beb@intel.com> (raw)
In-Reply-To: <20200116160602.GA28993@redsun51.ssa.fujisawa.hgst.com>
On 1/16/2020 9:06 AM, Keith Busch wrote:
> On Tue, Jan 14, 2020 at 11:17:45AM -0700, Edmund Nadolski wrote:
>> +static void nvme_exit_hctx(struct blk_mq_hw_ctx *hctx, unsigned int hctx_idx)
>> +{
>> + struct nvme_queue *nvmeq = hctx->driver_data;
>> +
>> + nvmeq->tags = NULL;
>> +}
>
> If you've multiple namespaces, disconnecting one of them will cause the
> shared nvmeq to have NULL tags, which will crash the kernel on the very
> next CQE read.
Currently it crashes with just a single namespace, because the nvmeq->tags is
still pointing into a tagset that was previously released by calling
nvme_free_tagset() from nvme_reset_work().
Perhaps the driver should not free the tagset unless & until there are no more
namespaces? Is nvme_remove_namespaces() supposed to ensure that?
Thanks,
Ed
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next prev parent reply other threads:[~2020-01-16 22:06 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-14 18:17 [PATCH] nvme: clear stale nvmeq->tags after tagset free Edmund Nadolski
2020-01-16 16:06 ` Keith Busch
2020-01-16 22:06 ` Nadolski, Edmund [this message]
2020-01-16 23:26 ` Keith Busch
2020-01-21 17:32 ` Nadolski, Edmund
2020-01-21 17:42 ` Keith Busch
2020-01-21 18:49 ` Nadolski, Edmund
2020-01-21 19:12 ` Keith Busch
2020-01-21 19:26 ` Nadolski, Edmund
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