[PATCH 9/9] [RFC] nvme: Fix a race condition
From: Bart Van Assche <hidden>
Date: 2016-09-26 18:29:08
Also in:
linux-nvme, linux-rdma, linux-scsi
Subsystem:
nvm express driver, the rest · Maintainers:
Keith Busch, Jens Axboe, Christoph Hellwig, Sagi Grimberg, Linus Torvalds
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 | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-)
diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 057f1fa..6e2bf6a 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);
@@ -2079,11 +2075,15 @@ EXPORT_SYMBOL_GPL(nvme_kill_queues); void nvme_stop_queues(struct nvme_ctrl *ctrl) { struct nvme_ns *ns; + struct request_queue *q; mutex_lock(&ctrl->namespaces_mutex); list_for_each_entry(ns, &ctrl->namespaces, list) { - blk_mq_cancel_requeue_work(ns->queue); - blk_mq_stop_hw_queues(ns->queue); + q = ns->queue; + blk_quiesce_queue(q); + blk_mq_cancel_requeue_work(q); + blk_mq_stop_hw_queues(q); + blk_resume_queue(q); } mutex_unlock(&ctrl->namespaces_mutex); }
--
2.10.0