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Date: Thu, 19 Nov 2015 14:20:47 +0100
From: David Sterba <dsterba@suse.cz>
To: Filipe Manana <fdmanana@gmail.com>
Cc: "dsterba@suse.cz" <dsterba@suse.cz>, Justin Maggard <jmaggard10@gmail.com>,
        "linux-btrfs@vger.kernel.org" <linux-btrfs@vger.kernel.org>,
        Justin Maggard <jmaggard@netgear.com>
Subject: Re: [PATCH] btrfs: qgroup: fix quota disable during rescan
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On Thu, Nov 19, 2015 at 01:16:42PM +0000, Filipe Manana wrote:
> On Thu, Nov 19, 2015 at 1:08 PM, David Sterba <dsterba@suse.cz> wrote:
> > Hi,
> >
> > On Fri, Nov 06, 2015 at 10:36:42AM -0800, Justin Maggard wrote:
> >> There's a race condition that leads to a NULL pointer dereference if you
> >> disable quotas while a quota rescan is running.  To fix this, we just need
> >> to wait for the quota rescan worker to actually exit before tearing down
> >> the quota structures.
> >
> > I see a reproducible crash in btrfs/115 (the fstest for this patch).
> > This is with 4.4-rc1, so the patch is included:
> 
> That's the expected crash, the patch isn't in 4.4-rc1.

Aha, thanks. I got confused with the other fix, "btrfs: qgroup: exit
the rescan worker during umount".