Commit 0bf77e9d authored by Ming Lin's avatar Ming Lin Committed by Jens Axboe
Browse files

nvme: switch to RCU freeing the namespace 



Switch to RCU freeing the namespace structure so that
nvme_start_queues, nvme_stop_queues and nvme_kill_queues would
be able to get away with only a RCU read side critical section.

Suggested-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarMing Lin <ming.l@ssi.samsung.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarKeith Busch <keith.busch@intel.com>
Reviewed-by: default avatarSagi Grimerg <sagi@grimberg.me>
Signed-off-by: default avatarJens Axboe <axboe@fb.com>
parent a5b714ad

drivers/nvme/host/core.c

+11 −10
Original line number Diff line number Diff line
@@ -1429,7 +1429,7 @@ static void nvme_alloc_ns(struct nvme_ctrl *ctrl, unsigned nsid) 
	if (nvme_revalidate_disk(ns->disk))

		goto out_free_disk;



	list_add_tail(&ns->list, &ctrl->namespaces);

	list_add_tail_rcu(&ns->list, &ctrl->namespaces);

	kref_get(&ctrl->kref);

	if (ns->type == NVME_NS_LIGHTNVM)

		return;
@@ -1467,6 +1467,7 @@ static void nvme_ns_remove(struct nvme_ns *ns) 
	mutex_lock(&ns->ctrl->namespaces_mutex);

	list_del_init(&ns->list);

	mutex_unlock(&ns->ctrl->namespaces_mutex);

	synchronize_rcu();

	nvme_put_ns(ns);

}
@@ -1751,8 +1752,8 @@ void nvme_kill_queues(struct nvme_ctrl *ctrl) 
{

	struct nvme_ns *ns;



	mutex_lock(&ctrl->namespaces_mutex);

	list_for_each_entry(ns, &ctrl->namespaces, list) {

	rcu_read_lock();

	list_for_each_entry_rcu(ns, &ctrl->namespaces, list) {

		if (!kref_get_unless_zero(&ns->kref))

			continue;
@@ -1769,7 +1770,7 @@ void nvme_kill_queues(struct nvme_ctrl *ctrl) 


		nvme_put_ns(ns);

	}

	mutex_unlock(&ctrl->namespaces_mutex);

	rcu_read_unlock();

}

EXPORT_SYMBOL_GPL(nvme_kill_queues);
@@ -1777,8 +1778,8 @@ void nvme_stop_queues(struct nvme_ctrl *ctrl) 
{

	struct nvme_ns *ns;



	mutex_lock(&ctrl->namespaces_mutex);

	list_for_each_entry(ns, &ctrl->namespaces, list) {

	rcu_read_lock();

	list_for_each_entry_rcu(ns, &ctrl->namespaces, list) {

		spin_lock_irq(ns->queue->queue_lock);

		queue_flag_set(QUEUE_FLAG_STOPPED, ns->queue);

		spin_unlock_irq(ns->queue->queue_lock);
@@ -1786,7 +1787,7 @@ void nvme_stop_queues(struct nvme_ctrl *ctrl) 
		blk_mq_cancel_requeue_work(ns->queue);

		blk_mq_stop_hw_queues(ns->queue);

	}

	mutex_unlock(&ctrl->namespaces_mutex);

	rcu_read_unlock();

}

EXPORT_SYMBOL_GPL(nvme_stop_queues);
@@ -1794,13 +1795,13 @@ void nvme_start_queues(struct nvme_ctrl *ctrl) 
{

	struct nvme_ns *ns;



	mutex_lock(&ctrl->namespaces_mutex);

	list_for_each_entry(ns, &ctrl->namespaces, list) {

	rcu_read_lock();

	list_for_each_entry_rcu(ns, &ctrl->namespaces, list) {

		queue_flag_clear_unlocked(QUEUE_FLAG_STOPPED, ns->queue);

		blk_mq_start_stopped_hw_queues(ns->queue, true);

		blk_mq_kick_requeue_list(ns->queue);

	}

	mutex_unlock(&ctrl->namespaces_mutex);

	rcu_read_unlock();

}

EXPORT_SYMBOL_GPL(nvme_start_queues);

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