From: "John Stoffel" <john@stoffel.org>
To: Yu Kuai <yukuai1@huaweicloud.com>
Cc: song@kernel.org, linux-raid@vger.kernel.org,
linux-kernel@vger.kernel.org, yukuai3@huawei.com,
yi.zhang@huawei.com
Subject: Re: [PATCH -next 1/3] md/raid10: fix improper BUG_ON() in raise_barrier()
Date: Mon, 29 Aug 2022 15:53:57 -0400 [thread overview]
Message-ID: <25357.6485.659159.476926@quad.stoffel.home> (raw)
In-Reply-To: <20220829131502.165356-2-yukuai1@huaweicloud.com>
>>>>> "Yu" == Yu Kuai <yukuai1@huaweicloud.com> writes:
Yu> From: Yu Kuai <yukuai3@huawei.com>
Yu> 'conf->barrier' is protected by 'conf->resync_lock', reading
Yu> 'conf->barrier' without holding the lock is wrong.
Yu> Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Yu> ---
Yu> drivers/md/raid10.c | 2 +-
Yu> 1 file changed, 1 insertion(+), 1 deletion(-)
Yu> diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
Yu> index 9117fcdee1be..b70c207f7932 100644
Yu> --- a/drivers/md/raid10.c
Yu> +++ b/drivers/md/raid10.c
Yu> @@ -930,8 +930,8 @@ static void flush_pending_writes(struct r10conf *conf)
Yu> static void raise_barrier(struct r10conf *conf, int force)
Yu> {
Yu> - BUG_ON(force && !conf->barrier);
Yu> spin_lock_irq(&conf->resync_lock);
Yu> + BUG_ON(force && !conf->barrier);
I don't like this BUG_ON() at all, why are you crashing the system
here instead of just doing a simple WARN_ONCE() instead? Is there
anything the user can do to get into this situation on their own, or
does it really signify a logic error in the code? If so, why are you
killing the system?
Yu> /* Wait until no block IO is waiting (unless 'force') */
Yu> wait_event_lock_irq(conf->wait_barrier, force || !conf->nr_waiting,
Yu> --
Yu> 2.31.1
next prev parent reply other threads:[~2022-08-29 19:54 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-08-29 13:14 [PATCH -next 0/3] md/raid10: reduce lock contention for io Yu Kuai
2022-08-29 13:15 ` [PATCH -next 1/3] md/raid10: fix improper BUG_ON() in raise_barrier() Yu Kuai
2022-08-29 19:53 ` John Stoffel [this message]
2022-08-30 1:01 ` Yu Kuai
2022-08-30 6:32 ` Paul Menzel
2022-08-29 13:15 ` [PATCH -next 2/3] md/raid10: convert resync_lock to use seqlock Yu Kuai
2022-09-01 18:41 ` Logan Gunthorpe
2022-09-02 0:49 ` Guoqing Jiang
2022-09-02 0:56 ` Logan Gunthorpe
2022-09-02 1:00 ` Guoqing Jiang
2022-09-02 1:21 ` Yu Kuai
2022-09-02 8:14 ` Yu Kuai
2022-09-02 17:03 ` Logan Gunthorpe
2022-09-03 6:07 ` Yu Kuai
2022-09-02 9:42 ` Guoqing Jiang
2022-09-02 10:02 ` Yu Kuai
2022-09-02 10:16 ` Guoqing Jiang
2022-09-02 10:53 ` Yu Kuai
2022-08-29 13:15 ` [PATCH -next 3/3] md/raid10: prevent unnecessary calls to wake_up() in fast path Yu Kuai
2022-08-29 13:40 ` [PATCH -next 0/3] md/raid10: reduce lock contention for io Guoqing Jiang
2022-08-31 11:55 ` Yu Kuai
2022-08-29 13:58 ` Paul Menzel
2022-08-30 1:09 ` Yu Kuai
2022-08-31 11:59 ` Paul Menzel
2022-08-31 12:07 ` Yu Kuai
2022-08-31 18:00 ` Song Liu
2022-09-03 6:08 ` Yu Kuai
2022-09-09 14:45 ` Song Liu
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