From: Stefan Bader <stefan.bader@canonical.com>
To: Slava Pestov <sp@datera.io>
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, 02 Dec 2014 09:49:45 +0100 [thread overview]
Message-ID: <547D7D29.8000602@canonical.com> (raw)
In-Reply-To: <CACHGV4J8pQM7pt+0NXJL60OJHxMUQu2S9U_DnKFh0BW0=1XpuA@mail.gmail.com>
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On 19.08.2014 20:03, Slava Pestov wrote:
> Thanks, this is now in our development branch.
It has been a while but I just went back there and checked linux and linux-next
but cannot find this change anywhere. I think it is a rather simple bugfix. So I
start to wonder where it went and when it would get pushed.
-Stefan
>
> 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
>>
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-bcache" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at http://vger.kernel.org/majordomo-info.html
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prev parent reply other threads:[~2014-12-02 8:49 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
2014-08-21 7:56 ` Stefan Bader
2014-12-02 8:49 ` Stefan Bader [this message]
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