From: David Sterba <dsterba@suse.cz>
To: Qu Wenruo <quwenruo.btrfs@gmx.com>
Cc: Josef Bacik <josef@toxicpanda.com>,
linux-btrfs@vger.kernel.org, kernel-team@fb.com
Subject: Re: [PATCH] btrfs: honor path->skip_locking in backref code
Date: Thu, 17 Jan 2019 15:30:21 +0100 [thread overview]
Message-ID: <20190117143021.GR2900@twin.jikos.cz> (raw)
In-Reply-To: <ef892414-ea36-271b-35f5-b4f753ff7bea@gmx.com>
On Thu, Jan 17, 2019 at 09:04:13AM +0800, Qu Wenruo wrote:
>
>
> On 2019/1/17 上午12:00, Josef Bacik wrote:
> > qgroups will do the old roots lookup at delayed ref time, which could be
> > while walking down the extent root while running a delayed ref. This
> > should be fine, except we specifically lock eb's in the backref walking
> > code irrespective of path->skip_locking, which deadlocks the system.
> > Fix up the backref code to honor path->skip_locking, nobody will be
> > modifying the commit_root when we're searching so it's completely safe
> > to do. Thanks,
> >
> > Signed-off-by: Josef Bacik <josef@toxicpanda.com>
>
> Reviewed-by: Qu Wenruo <wqu@suse.com>
What can we use from https://patchwork.kernel.org/patch/10725371/ to
add to the changelog? Is the deadlock caused by fb235dc06fac? The fix
applies to stable 4.19+ directly and to 4.14 with context fixups.
Thanks.
next prev parent reply other threads:[~2019-01-17 14:30 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-16 16:00 [PATCH] btrfs: honor path->skip_locking in backref code Josef Bacik
2019-01-17 1:04 ` Qu Wenruo
2019-01-17 14:30 ` David Sterba [this message]
2019-01-17 14:38 ` Qu Wenruo
2019-01-17 15:23 ` David Sterba
2019-01-18 13:39 ` David Sterba
2019-01-23 13:51 ` David Sterba
2019-02-12 5:07 ` Qu Wenruo
2019-02-12 14:19 ` David Sterba
2019-02-12 14:25 ` Qu Wenruo
2019-05-28 10:15 Qu Wenruo
2019-05-28 16:10 ` David Sterba
2019-05-28 10:18 Qu Wenruo
2019-05-28 16:10 ` David Sterba
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