From: hch@infradead.org (Christoph Hellwig)
Subject: nvmet: race condition while CQE are getting processed concurrently with the DISCONNECTED event
Date: Wed, 8 Mar 2017 07:46:05 -0800 [thread overview]
Message-ID: <20170308154605.GA28937@infradead.org> (raw)
In-Reply-To: <7dc99796-899e-b1a0-6ddb-cbfc497195dd@grimberg.me>
On Tue, Mar 07, 2017@03:33:27PM +0200, Sagi Grimberg wrote:
> 1. nvmet_sq_destroy is not doing its job for completing all
> its inflight requests. Although we do wait for the final
> ref on the nvmet_sq to drop to zero.
> For that perhaps you can try patch [1].
Yes, I'll think we need that. Did I mention that the percpu
refounter API is a complete trainwreck a couple times? :)
> 2. ib_destroy_cq does not really protect against a case where
> the work requeue itself because it runs flush_work(). In this
> case when the work re-executes it polls a cq array that is
> already freed and sees a bogus successful completion. Perhaps
> ib_free_cq should run cancel_work_sync() instead? see [2].
Yeah, we'll probably need that as well. Independent of it solves
the problem reported here.
next prev parent reply other threads:[~2017-03-08 15:46 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CY1PR12MB077418C35F6EA2499CBACA45BC2C0@CY1PR12MB0774.namprd12.prod.outlook.com>
2017-03-07 13:33 ` nvmet: race condition while CQE are getting processed concurrently with the DISCONNECTED event Sagi Grimberg
2017-03-08 15:46 ` Christoph Hellwig [this message]
2017-03-08 19:34 ` Sagi Grimberg
[not found] <CY1PR12MB07747089AFFCB6115BBCF5ECBC210@CY1PR12MB0774.namprd12.prod.outlook.com>
2017-03-09 11:45 ` Sagi Grimberg
2017-03-11 8:29 ` Raju Rangoju
2017-03-13 2:22 ` Yi Zhang
2017-03-13 8:05 ` Sagi Grimberg
2017-03-14 13:22 ` Yi Zhang
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