From: Bart Van Assche <bvanassche@acm.org>
To: Ming Lei <ming.lei@redhat.com>, Jens Axboe <axboe@kernel.dk>
Cc: linux-block@vger.kernel.org, linux-scsi@vger.kernel.org,
"Martin K. Petersen" <martin.petersen@oracle.com>,
luojiaxing <luojiaxing@huawei.com>
Subject: Re: [PATCH] blk-mq: avoid to iterate over stale request
Date: Mon, 6 Sep 2021 15:44:08 -0700 [thread overview]
Message-ID: <5bf71295-b729-2ec7-3913-afad3c5d2ef7@acm.org> (raw)
In-Reply-To: <20210906065003.439019-1-ming.lei@redhat.com>
On 9/5/21 23:50, Ming Lei wrote:
> - if (!rq || !refcount_inc_not_zero(&rq->ref))
> + if (!rq || rq->tag != bitnr || !refcount_inc_not_zero(&rq->ref))
> rq = NULL;
Shouldn't the rq->tag != bitnr test happen after the refcount has been
incremented since otherwise rq->tag can change after it has been read
and before the refcount is incremented?
Thanks,
Bart.
next prev parent reply other threads:[~2021-09-06 22:44 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-06 6:50 [PATCH] blk-mq: avoid to iterate over stale request Ming Lei
2021-09-06 22:44 ` Bart Van Assche [this message]
2021-09-07 1:14 ` Ming Lei
2021-09-13 1:26 ` Ming Lei
2021-09-13 1:31 ` Jens Axboe
2021-12-14 18:41 ` Kashyap Desai
2021-12-15 3:36 ` Ming Lei
2021-12-15 7:30 ` Kashyap Desai
2021-12-15 8:02 ` Ming Lei
2021-12-15 8:45 ` Kashyap Desai
2021-12-15 12:56 ` Ming Lei
2021-12-16 11:55 ` Kashyap Desai
2021-12-16 12:50 ` Ming Lei
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