Re: [PATCH 4.19 112/113] libnvdimm/bus: Stop holding nvdimm_bus_list_mutex over __nd_ioctl()

[Greg Kroah-Hartman]

On Wed, Jul 31, 2019 at 12:31:07PM -0700, Dan Williams wrote:
> On Wed, Jul 31, 2019 at 11:15 AM Pavel Machek <pavel@xxxxxxx> wrote:
> >
> > On Mon 2019-07-29 21:23:19, Greg Kroah-Hartman wrote:
> > > From: Dan Williams <dan.j.williams@xxxxxxxxx>
> > >
> > > commit b70d31d054ee3a6fc1034b9d7fc0ae1e481aa018 upstream.
> > >
> > > In preparation for fixing a deadlock between wait_for_bus_probe_idle()
> > > and the nvdimm_bus_list_mutex arrange for __nd_ioctl() without
> > > nvdimm_bus_list_mutex held. This also unifies the 'dimm' and 'bus' level
> > > ioctls into a common nd_ioctl() preamble implementation.
> >
> > Ok, so this is a preparation patch, not a fix...
> >
> > > Marked for -stable as it is a pre-requisite for a follow-on fix.
> >
> > ...but follow-on fixes are going to be applied for 5.2 but not
> > 4.19. So perhaps this one should not be in 4.19, either?
> 
> I plan to follow up with a backport of the series for 4.19. I have no
> problem with v4.19 carrying this in the meantime, but if you want to
> kick it out and wait for the backport, that's fine too.

I didn't mean to include this, I was going to go and remove it, my fault
for keeping it in.  But, if you are going to send the series backported,
I'll leave this in for now as that will make your work easier.

thanks,

greg k-h