From: Bart Van Assche <Bart.VanAssche@wdc.com>
To: "jiangqi903@gmail.com" <jiangqi903@gmail.com>,
"joseph.qi@linux.alibaba.com" <joseph.qi@linux.alibaba.com>,
"axboe@kernel.dk" <axboe@kernel.dk>
Cc: "hch@lst.de" <hch@lst.de>,
"ulf.hansson@linaro.org" <ulf.hansson@linaro.org>,
"linux-block@vger.kernel.org" <linux-block@vger.kernel.org>,
"philipp.reisner@linbit.com" <philipp.reisner@linbit.com>,
"stable@vger.kernel.org" <stable@vger.kernel.org>,
"keescook@chromium.org" <keescook@chromium.org>
Subject: Re: [PATCH v2 2/2] block: Fix a race between the throttling code and request queue initialization
Date: Fri, 2 Feb 2018 16:21:59 +0000 [thread overview]
Message-ID: <1517588518.2675.14.camel@wdc.com> (raw)
In-Reply-To: <26f758cf-430c-aa7f-0d21-75fbad6db260@gmail.com>
On Fri, 2018-02-02 at 09:02 +0800, Joseph Qi wrote:
> We triggered this race when using single queue. I'm not sure if it
> exists in multi-queue.
Regarding the races between modifying the queue_lock pointer and the code that
uses that pointer, I think the following construct in blk_cleanup_queue() is
sufficient to avoid races between the queue_lock pointer assignment and the code
that executes concurrently with blk_cleanup_queue():
spin_lock_irq(lock);
if (q->queue_lock != &q->__queue_lock)
q->queue_lock = &q->__queue_lock;
spin_unlock_irq(lock);
In other words, I think that this patch series should be sufficient to address
all races between .queue_lock assignments and the code that uses that pointer.
Thanks,
Bart.
next prev parent reply other threads:[~2018-02-02 16:22 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20180131235300.12773-1-bart.vanassche@wdc.com>
2018-01-31 23:52 ` [PATCH v2 1/2] block: Add a third argument to blk_alloc_queue_node() Bart Van Assche
2018-01-31 23:53 ` [PATCH v2 2/2] block: Fix a race between the throttling code and request queue initialization Bart Van Assche
2018-02-01 1:53 ` Joseph Qi
2018-02-01 16:16 ` Bart Van Assche
2018-02-02 1:02 ` Joseph Qi
2018-02-02 14:52 ` Jens Axboe
2018-02-02 16:21 ` Bart Van Assche [this message]
2018-02-03 2:51 ` Joseph Qi
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