Re: [bug report from blktests nvme/032] WARNING: possible circular locking dependency detected

[Greg Kroah-Hartman]

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@xxxxxxxxxxx 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...