From: Slava Pestov <sp@datera.io>
To: Stefan Bader <stefan.bader@canonical.com>
Cc: linux-kernel@vger.kernel.org, linux-bcache@vger.kernel.org,
Kent Overstreet <kmo@daterainc.com>
Subject: Re: [PATCH] bcache: prevent crash on changing writeback_running
Date: Tue, 19 Aug 2014 11:03:11 -0700 [thread overview]
Message-ID: <CACHGV4J8pQM7pt+0NXJL60OJHxMUQu2S9U_DnKFh0BW0=1XpuA@mail.gmail.com> (raw)
In-Reply-To: <1408453293-17917-1-git-send-email-stefan.bader@canonical.com>
Thanks, this is now in our development branch.
On Tue, Aug 19, 2014 at 6:01 AM, Stefan Bader
<stefan.bader@canonical.com> wrote:
> commit a664d0f05a2ec02c8f042db536d84d15d6e19e81
> bcache: fix crash on shutdown in passthrough mode
>
> added a safeguard in the shutdown case. At least while not being
> attached it is also possible to trigger a kernel bug by writing into
> writeback_running. This change adds the same check before trying to
> wake up the thread for that case.
>
> Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
> ---
> drivers/md/bcache/writeback.h | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/md/bcache/writeback.h b/drivers/md/bcache/writeback.h
> index 0a9dab1..073a042 100644
> --- a/drivers/md/bcache/writeback.h
> +++ b/drivers/md/bcache/writeback.h
> @@ -63,7 +63,8 @@ static inline bool should_writeback(struct cached_dev *dc, struct bio *bio,
>
> static inline void bch_writeback_queue(struct cached_dev *dc)
> {
> - wake_up_process(dc->writeback_thread);
> + if (!IS_ERR_OR_NULL(dc->writeback_thread))
> + wake_up_process(dc->writeback_thread);
> }
>
> static inline void bch_writeback_add(struct cached_dev *dc)
> --
> 1.9.1
>
> --
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next prev parent reply other threads:[~2014-08-19 18:03 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-08-19 13:01 [PATCH] bcache: prevent crash on changing writeback_running Stefan Bader
2014-08-19 18:03 ` Slava Pestov [this message]
2014-08-21 7:56 ` Stefan Bader
2014-12-02 8:49 ` Stefan Bader
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