Re: [PATCH v2 7/7] [RFC] nvme: Fix a race condition
From: Christoph Hellwig <hch@lst.de>
Date: 2016-10-11 16:46:01
Also in:
linux-nvme, linux-rdma, linux-scsi
On Wed, Sep 28, 2016 at 05:01:45PM -0700, Bart Van Assche wrote:
quoted hunk ↗ jump to hunk
Avoid that nvme_queue_rq() is still running when nvme_stop_queues() returns. Untested. Signed-off-by: Bart Van Assche <redacted> Cc: Keith Busch <redacted> Cc: Christoph Hellwig <hch@lst.de> Cc: Sagi Grimberg <sagi@grimberg.me> --- drivers/nvme/host/core.c | 20 ++++++++++++-------- 1 file changed, 12 insertions(+), 8 deletions(-)diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c index d791fba..98f1f29 100644 --- a/drivers/nvme/host/core.c +++ b/drivers/nvme/host/core.c@@ -201,13 +201,9 @@ fail: void nvme_requeue_req(struct request *req) { - unsigned long flags; - blk_mq_requeue_request(req); - spin_lock_irqsave(req->q->queue_lock, flags); - if (!blk_mq_queue_stopped(req->q)) - blk_mq_kick_requeue_list(req->q); - spin_unlock_irqrestore(req->q->queue_lock, flags); + WARN_ON_ONCE(blk_mq_queue_stopped(req->q)); + blk_mq_kick_requeue_list(req->q); } EXPORT_SYMBOL_GPL(nvme_requeue_req);
Can we just add a 'bool kick' argument to blk_mq_requeue_request and move all this handling to the core?