Commit ff8d6fac authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'for-linus' of git://git.kernel.dk/linux-block 

Pull NVMe fix from Jens Axboe:
 "Late addition here, it's basically a revert of a patch that was added
  in this merge window, but has proven to cause problems.

  This is swapping out the RCU based namespace protection with a good
  old mutex instead"

* 'for-linus' of git://git.kernel.dk/linux-block:
  nvme: Remove RCU namespace protection
parents 47ef4ad2 32f0c4af

drivers/nvme/host/core.c

+39 −35
Original line number Diff line number Diff line
@@ -1394,19 +1394,22 @@ static int ns_cmp(void *priv, struct list_head *a, struct list_head *b) 
	return nsa->ns_id - nsb->ns_id;

}



static struct nvme_ns *nvme_find_ns(struct nvme_ctrl *ctrl, unsigned nsid)

static struct nvme_ns *nvme_find_get_ns(struct nvme_ctrl *ctrl, unsigned nsid)

{

	struct nvme_ns *ns;



	lockdep_assert_held(&ctrl->namespaces_mutex);

	struct nvme_ns *ns, *ret = NULL;



	mutex_lock(&ctrl->namespaces_mutex);

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

		if (ns->ns_id == nsid)

			return ns;

		if (ns->ns_id == nsid) {

			kref_get(&ns->kref);

			ret = ns;

			break;

		}

		if (ns->ns_id > nsid)

			break;

	}

	return NULL;

	mutex_unlock(&ctrl->namespaces_mutex);

	return ret;

}



static void nvme_alloc_ns(struct nvme_ctrl *ctrl, unsigned nsid)
@@ -1415,8 +1418,6 @@ static void nvme_alloc_ns(struct nvme_ctrl *ctrl, unsigned nsid) 
	struct gendisk *disk;

	int node = dev_to_node(ctrl->dev);



	lockdep_assert_held(&ctrl->namespaces_mutex);



	ns = kzalloc_node(sizeof(*ns), GFP_KERNEL, node);

	if (!ns)

		return;
@@ -1457,7 +1458,10 @@ static void nvme_alloc_ns(struct nvme_ctrl *ctrl, unsigned nsid) 
	if (nvme_revalidate_disk(ns->disk))

		goto out_free_disk;



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

	mutex_lock(&ctrl->namespaces_mutex);

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

	mutex_unlock(&ctrl->namespaces_mutex);



	kref_get(&ctrl->kref);

	if (ns->type == NVME_NS_LIGHTNVM)

		return;
@@ -1480,8 +1484,6 @@ static void nvme_alloc_ns(struct nvme_ctrl *ctrl, unsigned nsid) 


static void nvme_ns_remove(struct nvme_ns *ns)

{

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



	if (test_and_set_bit(NVME_NS_REMOVING, &ns->flags))

		return;
@@ -1494,8 +1496,11 @@ static void nvme_ns_remove(struct nvme_ns *ns) 
		blk_mq_abort_requeue_list(ns->queue);

		blk_cleanup_queue(ns->queue);

	}



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

	list_del_init(&ns->list);

	synchronize_rcu();

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



	nvme_put_ns(ns);

}
@@ -1503,10 +1508,11 @@ static void nvme_validate_ns(struct nvme_ctrl *ctrl, unsigned nsid) 
{

	struct nvme_ns *ns;



	ns = nvme_find_ns(ctrl, nsid);

	ns = nvme_find_get_ns(ctrl, nsid);

	if (ns) {

		if (revalidate_disk(ns->disk))

			nvme_ns_remove(ns);

		nvme_put_ns(ns);

	} else

		nvme_alloc_ns(ctrl, nsid);

}
@@ -1535,9 +1541,11 @@ static int nvme_scan_ns_list(struct nvme_ctrl *ctrl, unsigned nn) 
			nvme_validate_ns(ctrl, nsid);



			while (++prev < nsid) {

				ns = nvme_find_ns(ctrl, prev);

				if (ns)

				ns = nvme_find_get_ns(ctrl, prev);

				if (ns) {

					nvme_ns_remove(ns);

					nvme_put_ns(ns);

				}

			}

		}

		nn -= j;
@@ -1552,8 +1560,6 @@ static void nvme_scan_ns_sequential(struct nvme_ctrl *ctrl, unsigned nn) 
	struct nvme_ns *ns, *next;

	unsigned i;



	lockdep_assert_held(&ctrl->namespaces_mutex);



	for (i = 1; i <= nn; i++)

		nvme_validate_ns(ctrl, i);
@@ -1576,7 +1582,6 @@ static void nvme_scan_work(struct work_struct *work) 
	if (nvme_identify_ctrl(ctrl, &id))

		return;



	mutex_lock(&ctrl->namespaces_mutex);

	nn = le32_to_cpu(id->nn);

	if (ctrl->vs >= NVME_VS(1, 1) &&

	    !(ctrl->quirks & NVME_QUIRK_IDENTIFY_CNS)) {
@@ -1585,6 +1590,7 @@ static void nvme_scan_work(struct work_struct *work) 
	}

	nvme_scan_ns_sequential(ctrl, nn);

 done:

	mutex_lock(&ctrl->namespaces_mutex);

	list_sort(NULL, &ctrl->namespaces, ns_cmp);

	mutex_unlock(&ctrl->namespaces_mutex);

	kfree(id);
@@ -1604,6 +1610,11 @@ void nvme_queue_scan(struct nvme_ctrl *ctrl) 
}

EXPORT_SYMBOL_GPL(nvme_queue_scan);



/*

 * This function iterates the namespace list unlocked to allow recovery from

 * controller failure. It is up to the caller to ensure the namespace list is

 * not modified by scan work while this function is executing.

 */

void nvme_remove_namespaces(struct nvme_ctrl *ctrl)

{

	struct nvme_ns *ns, *next;
@@ -1617,10 +1628,8 @@ void nvme_remove_namespaces(struct nvme_ctrl *ctrl) 
	if (ctrl->state == NVME_CTRL_DEAD)

		nvme_kill_queues(ctrl);



	mutex_lock(&ctrl->namespaces_mutex);

	list_for_each_entry_safe(ns, next, &ctrl->namespaces, list)

		nvme_ns_remove(ns);

	mutex_unlock(&ctrl->namespaces_mutex);

}

EXPORT_SYMBOL_GPL(nvme_remove_namespaces);
@@ -1791,11 +1800,8 @@ void nvme_kill_queues(struct nvme_ctrl *ctrl) 
{

	struct nvme_ns *ns;



	rcu_read_lock();

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

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

			continue;



	mutex_lock(&ctrl->namespaces_mutex);

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

		/*

		 * Revalidating a dead namespace sets capacity to 0. This will

		 * end buffered writers dirtying pages that can't be synced.
@@ -1806,10 +1812,8 @@ void nvme_kill_queues(struct nvme_ctrl *ctrl) 
		blk_set_queue_dying(ns->queue);

		blk_mq_abort_requeue_list(ns->queue);

		blk_mq_start_stopped_hw_queues(ns->queue, true);



		nvme_put_ns(ns);

	}

	rcu_read_unlock();

	mutex_unlock(&ctrl->namespaces_mutex);

}

EXPORT_SYMBOL_GPL(nvme_kill_queues);
@@ -1817,8 +1821,8 @@ void nvme_stop_queues(struct nvme_ctrl *ctrl) 
{

	struct nvme_ns *ns;



	rcu_read_lock();

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

	mutex_lock(&ctrl->namespaces_mutex);

	list_for_each_entry(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);
@@ -1826,7 +1830,7 @@ void nvme_stop_queues(struct nvme_ctrl *ctrl) 
		blk_mq_cancel_requeue_work(ns->queue);

		blk_mq_stop_hw_queues(ns->queue);

	}

	rcu_read_unlock();

	mutex_unlock(&ctrl->namespaces_mutex);

}

EXPORT_SYMBOL_GPL(nvme_stop_queues);
@@ -1834,13 +1838,13 @@ void nvme_start_queues(struct nvme_ctrl *ctrl) 
{

	struct nvme_ns *ns;



	rcu_read_lock();

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

	mutex_lock(&ctrl->namespaces_mutex);

	list_for_each_entry(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);

	}

	rcu_read_unlock();

	mutex_unlock(&ctrl->namespaces_mutex);

}

EXPORT_SYMBOL_GPL(nvme_start_queues);

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