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From:   Dan Williams <dan.j.williams@intel.com>
Date:   Wed, 31 Jul 2019 12:31:07 -0700
Message-ID: <CAPcyv4iM3i3oBS3WRe8QHmD6zncAy0-CsgdbJ0WSt9RBiVgVqg@mail.gmail.com>
Subject: Re: [PATCH 4.19 112/113] libnvdimm/bus: Stop holding
 nvdimm_bus_list_mutex over __nd_ioctl()
To:     Pavel Machek <pavel@denx.de>
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        stable <stable@vger.kernel.org>,
        Vishal Verma <vishal.l.verma@intel.com>,
        Jane Chu <jane.chu@oracle.com>
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On Wed, Jul 31, 2019 at 11:15 AM Pavel Machek <pavel@denx.de> wrote:
>
> On Mon 2019-07-29 21:23:19, Greg Kroah-Hartman wrote:
> > From: Dan Williams <dan.j.williams@intel.com>
> >
> > 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.