NVMe: Remove queue freezing on resets

NVMe submits all commands through the block layer now. This means we
can let requests queue at the blk-mq hardware context since there is no
path that bypasses this anymore so we don't need to freeze the queues
anymore. The driver can simply stop the h/w queues from running during
a reset instead.

This also fixes a WARN in percpu_ref_reinit when the queue was unfrozen
with requeued requests.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 8da4a8a55c496c269c4b97691e4fa579720b2d46..e31a256127f74db5e4ac1f816dd2ac53a2b861b0 100644 (file)
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -1372,14 +1372,12 @@ out:
        return ret;
 }
 
-void nvme_freeze_queues(struct nvme_ctrl *ctrl)
+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) {
-               blk_mq_freeze_queue_start(ns->queue);
-
                spin_lock_irq(ns->queue->queue_lock);
                queue_flag_set(QUEUE_FLAG_STOPPED, ns->queue);
                spin_unlock_irq(ns->queue->queue_lock);
@@ -1390,14 +1388,13 @@ void nvme_freeze_queues(struct nvme_ctrl *ctrl)
        mutex_unlock(&ctrl->namespaces_mutex);
 }
 
-void nvme_unfreeze_queues(struct nvme_ctrl *ctrl)
+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) {
                queue_flag_clear_unlocked(QUEUE_FLAG_STOPPED, ns->queue);
-               blk_mq_unfreeze_queue(ns->queue);
                blk_mq_start_stopped_hw_queues(ns->queue, true);
                blk_mq_kick_requeue_list(ns->queue);
        }

diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index 44375923bd6a100f561535e567d9b987987da8b2..4722fadde0f1310a26b8946dbeac5a56824abdcd 100644 (file)
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -238,8 +238,8 @@ int nvme_init_identify(struct nvme_ctrl *ctrl);
 void nvme_scan_namespaces(struct nvme_ctrl *ctrl);
 void nvme_remove_namespaces(struct nvme_ctrl *ctrl);
 
-void nvme_freeze_queues(struct nvme_ctrl *ctrl);
-void nvme_unfreeze_queues(struct nvme_ctrl *ctrl);
+void nvme_stop_queues(struct nvme_ctrl *ctrl);
+void nvme_start_queues(struct nvme_ctrl *ctrl);
 
 struct request *nvme_alloc_request(struct request_queue *q,
                struct nvme_command *cmd, unsigned int flags);

diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index ac6c7afb2a6ed03ab1ccd27d3f3964f0a751fbf1..953fe485a258cf8b67a296e6e566d98d9afd5782 100644 (file)
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -1064,7 +1064,7 @@ static int nvme_suspend_queue(struct nvme_queue *nvmeq)
        spin_unlock_irq(&nvmeq->q_lock);
 
        if (!nvmeq->qid && nvmeq->dev->ctrl.admin_q)
-               blk_mq_freeze_queue_start(nvmeq->dev->ctrl.admin_q);
+               blk_mq_stop_hw_queues(nvmeq->dev->ctrl.admin_q);
 
        irq_set_affinity_hint(vector, NULL);
        free_irq(vector, nvmeq);
@@ -1296,7 +1296,7 @@ static int nvme_alloc_admin_tags(struct nvme_dev *dev)
                        return -ENODEV;
                }
        } else
-               blk_mq_unfreeze_queue(dev->ctrl.admin_q);
+               blk_mq_start_stopped_hw_queues(dev->ctrl.admin_q, true);
 
        return 0;
 }
@@ -1917,7 +1917,7 @@ static void nvme_dev_shutdown(struct nvme_dev *dev)
 
        mutex_lock(&dev->shutdown_lock);
        if (dev->bar) {
-               nvme_freeze_queues(&dev->ctrl);
+               nvme_stop_queues(&dev->ctrl);
                csts = readl(dev->bar + NVME_REG_CSTS);
        }
        if (csts & NVME_CSTS_CFS || !(csts & NVME_CSTS_RDY)) {
@@ -2026,7 +2026,7 @@ static void nvme_reset_work(struct work_struct *work)
                dev_warn(dev->dev, "IO queues not created\n");
                nvme_remove_namespaces(&dev->ctrl);
        } else {
-               nvme_unfreeze_queues(&dev->ctrl);
+               nvme_start_queues(&dev->ctrl);
                nvme_dev_add(dev);
        }