@@ -3447,6 +3447,9 @@ int nvme_init_ctrl(struct nvme_ctrl *ctrl, struct device *dev,
INIT_WORK(&ctrl->fw_act_work, nvme_fw_act_work);
INIT_WORK(&ctrl->delete_work, nvme_delete_ctrl_work);
+ ctrl->queues_freezed = false;
+ mutex_init(&ctrl->freeze_mutex);
+
ret = ida_simple_get(&nvme_instance_ida, 0, 0, GFP_KERNEL);
if (ret < 0)
goto out;
@@ -3526,10 +3529,15 @@ void nvme_unfreeze(struct nvme_ctrl *ctrl)
{
struct nvme_ns *ns;
- down_read(&ctrl->namespaces_rwsem);
- list_for_each_entry(ns, &ctrl->namespaces, list)
- blk_mq_unfreeze_queue(ns->queue);
- up_read(&ctrl->namespaces_rwsem);
+ mutex_lock(&ctrl->freeze_mutex);
+ if (ctrl->queues_freezed) {
+ down_read(&ctrl->namespaces_rwsem);
+ list_for_each_entry(ns, &ctrl->namespaces, list)
+ blk_mq_unfreeze_queue(ns->queue);
+ up_read(&ctrl->namespaces_rwsem);
+ ctrl->queues_freezed = false;
+ }
+ mutex_unlock(&ctrl->freeze_mutex);
}
EXPORT_SYMBOL_GPL(nvme_unfreeze);
@@ -3562,10 +3570,15 @@ void nvme_start_freeze(struct nvme_ctrl *ctrl)
{
struct nvme_ns *ns;
- down_read(&ctrl->namespaces_rwsem);
- list_for_each_entry(ns, &ctrl->namespaces, list)
- blk_freeze_queue_start(ns->queue);
- up_read(&ctrl->namespaces_rwsem);
+ mutex_lock(&ctrl->freeze_mutex);
+ if (!ctrl->queues_freezed) {
+ down_read(&ctrl->namespaces_rwsem);
+ list_for_each_entry(ns, &ctrl->namespaces, list)
+ blk_freeze_queue_start(ns->queue);
+ up_read(&ctrl->namespaces_rwsem);
+ ctrl->queues_freezed = true;
+ }
+ mutex_unlock(&ctrl->freeze_mutex);
}
EXPORT_SYMBOL_GPL(nvme_start_freeze);
@@ -149,6 +149,9 @@ struct nvme_ctrl {
struct work_struct reset_work;
struct work_struct delete_work;
+ bool queues_freezed;
+ struct mutex freeze_mutex;
+
struct nvme_subsystem *subsys;
struct list_head subsys_entry;
nvme_dev_disable() and resetting controller are required for recovering controller, but the two are run from different contexts. nvme_start_freeze() is run from nvme_dev_disable(), and nvme_unfreeze() is run from resetting context. Unfortunatley timeout may be triggered when draining IO from resetting controller, so nvme_start_freeze() may be run several times. This patch fixes the race between nvme_start_freeze() and nvme_unfreeze() by introducing flags of 'queues_freezed' and the lock of 'freeze_mutex'. Cc: Jianchao Wang <jianchao.w.wang@oracle.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Sagi Grimberg <sagi@grimberg.me> Cc: linux-nvme@lists.infradead.org Signed-off-by: Ming Lei <ming.lei@redhat.com> --- drivers/nvme/host/core.c | 29 +++++++++++++++++++++-------- drivers/nvme/host/nvme.h | 3 +++ 2 files changed, 24 insertions(+), 8 deletions(-)