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Date:   Tue, 28 Jun 2022 08:12:51 +0200
From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     Christoph Hellwig <hch@infradead.org>
Cc:     "yangx.jy@fujitsu.com" <yangx.jy@fujitsu.com>,
        Tejun Heo <tj@kernel.org>, Bjorn Helgaas <bhelgaas@google.com>,
        Jason Gunthorpe <jgg@ziepe.ca>,
        Leon Romanovsky <leon@kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "linux-rdma@vger.kernel.org" <linux-rdma@vger.kernel.org>,
        "linux-block@vger.kernel.org" <linux-block@vger.kernel.org>
Subject: Re: [bug report from blktests nvme/032] WARNING: possible circular
 locking dependency detected
Message-ID: <Yrqb47ozk5IWTnWp@kroah.com>
References: <4ed3028b-2d2f-8755-fec2-0b9cb5ad42d2@fujitsu.com>
 <YrqauCHdcieF5+C7@kroah.com>
 <YrqbNfF9uYMSwZ4V@infradead.org>
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On Mon, Jun 27, 2022 at 11:09:57PM -0700, Christoph Hellwig wrote:
> On Tue, Jun 28, 2022 at 08:07:52AM +0200, Greg Kroah-Hartman wrote:
> > On Tue, Jun 28, 2022 at 04:03:55AM +0000, yangx.jy@fujitsu.com wrote:
> > > Hi everyone,
> > > 
> > > Running blktests nvme/032 on kernel v5.19-rc2+ which enables 
> > > CONFIG_LOCKDEP and CONFIG_PROVE_LOCKING triggered the below WARNING.
> > 
> > What was happening when this trace was created?  It looks like you were
> > manually removing a PCI device from the system through sysfs?  Why would
> > blktests do that?
> 
> To test how the block layer copes with the fact that the underlying
> device goes away.

Ah, so it's a fake PCI device, or is it a real one?

Anyway, it's a valid thing to do, I'll look at the report in a bit...