nvme-core: introduce sync io queues

mainline inclusion
from mainline-v5.10-rc3
commit 04800fbf
category: bugfix
bugzilla: NA
CVE: NA
Link: https://gitee.com/openeuler/kernel/issues/I1WGZE

-------------------------------------------------

Introduce sync io queues for some scenarios which just only need sync
io queues not sync all queues.
Signed-off-by: NChao Leng <lengchao@huawei.com>
Reviewed-by: NSagi Grimberg <sagi@grimberg.me>
Reviewed-by: NJike Cheng <chengjike.cheng@huawei.com>
Signed-off-by: NRuozhu Li <liruozhu@huawei.com>
Signed-off-by: NLijie <lijie34@huawei.com>
Acked-by: NHanjun Guo <guohanjun@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

drivers/nvme/host/core.c

@@ -3895,6 +3895,17 @@ void nvme_start_queues(struct nvme_ctrl *ctrl)
 }
 EXPORT_SYMBOL_GPL(nvme_start_queues);
 
+void nvme_sync_io_queues(struct nvme_ctrl *ctrl)
+{
+	struct nvme_ns *ns;
+
+	down_read(&ctrl->namespaces_rwsem);
+	list_for_each_entry(ns, &ctrl->namespaces, list)
+		blk_sync_queue(ns->queue);
+	up_read(&ctrl->namespaces_rwsem);
+}
+EXPORT_SYMBOL_GPL(nvme_sync_io_queues);
+
 int __init nvme_core_init(void)
 {
 	int result = -ENOMEM;

drivers/nvme/host/nvme.h

@@ -439,6 +439,7 @@ void nvme_complete_async_event(struct nvme_ctrl *ctrl, __le16 status,
 void nvme_stop_queues(struct nvme_ctrl *ctrl);
 void nvme_start_queues(struct nvme_ctrl *ctrl);
 void nvme_kill_queues(struct nvme_ctrl *ctrl);
+void nvme_sync_io_queues(struct nvme_ctrl *ctrl);
 void nvme_unfreeze(struct nvme_ctrl *ctrl);
 void nvme_wait_freeze(struct nvme_ctrl *ctrl);
 void nvme_wait_freeze_timeout(struct nvme_ctrl *ctrl, long timeout);