[RFC PATCH 1/4] nvme: unfreeze while exit from recovery or resetting

[brookxu.cn]

From: Chunguang Xu <chunguang.xu at shopee.com>

Remove controller will interrupt err_work/connect_work, leave
controller at freezed and IO queues at quiescing. Then IOs
issued by scan_work will be blocked,  nvme_remove_namespaces()
will hang on fush scan_work. Try to fix that we should unfreeze
contrller and unquiescing IO queues while exit from
error_recovery or resetting.

Signed-off-by: Chunguang Xu <chunguang.xu at shopee.com>
---
 drivers/nvme/host/tcp.c | 24 ++++++++++++++++--------
 1 file changed, 16 insertions(+), 8 deletions(-)

diff --git a/drivers/nvme/host/tcp.c b/drivers/nvme/host/tcp.c
index bf0230442d57..cfebcae7fc9b 100644
--- a/drivers/nvme/host/tcp.c
+++ b/drivers/nvme/host/tcp.c
@@ -2031,12 +2031,24 @@ static void nvme_tcp_teardown_io_queues(struct nvme_ctrl *ctrl,
 	nvme_tcp_destroy_io_queues(ctrl, remove);
 }
 
+static inline void nvme_ctrl_reconnect_exit(struct nvme_ctrl *ctrl)
+{
+	/* fast fail all pending requests */
+	blk_mq_unquiesce_queue(ctrl->admin_q);
+
+	if (ctrl->queue_count > 1) {
+		nvme_unquiesce_io_queues(ctrl);
+		nvme_unfreeze(ctrl);
+	}
+}
+
 static void nvme_tcp_reconnect_or_remove(struct nvme_ctrl *ctrl)
 {
 	/* If we are resetting/deleting then do nothing */
 	if (ctrl->state != NVME_CTRL_CONNECTING) {
 		WARN_ON_ONCE(ctrl->state == NVME_CTRL_NEW ||
 			ctrl->state == NVME_CTRL_LIVE);
+		nvme_ctrl_reconnect_exit(ctrl);
 		return;
 	}
 
@@ -2107,13 +2119,7 @@ static int nvme_tcp_setup_ctrl(struct nvme_ctrl *ctrl, bool new)
 	return 0;
 
 destroy_io:
-	if (ctrl->queue_count > 1) {
-		nvme_quiesce_io_queues(ctrl);
-		nvme_sync_io_queues(ctrl);
-		nvme_tcp_stop_io_queues(ctrl);
-		nvme_cancel_tagset(ctrl);
-		nvme_tcp_destroy_io_queues(ctrl, new);
-	}
+	nvme_tcp_teardown_io_queues(ctrl, new);
 destroy_admin:
 	nvme_quiesce_admin_queue(ctrl);
 	blk_sync_queue(ctrl->admin_q);
@@ -2166,6 +2172,7 @@ static void nvme_tcp_error_recovery_work(struct work_struct *work)
 		/* state change failure is ok if we started ctrl delete */
 		WARN_ON_ONCE(ctrl->state != NVME_CTRL_DELETING &&
 			     ctrl->state != NVME_CTRL_DELETING_NOIO);
+		nvme_ctrl_reconnect_exit(ctrl);
 		return;
 	}
 
@@ -2197,6 +2204,7 @@ static void nvme_reset_ctrl_work(struct work_struct *work)
 		/* state change failure is ok if we started ctrl delete */
 		WARN_ON_ONCE(ctrl->state != NVME_CTRL_DELETING &&
 			     ctrl->state != NVME_CTRL_DELETING_NOIO);
+		nvme_ctrl_reconnect_exit(ctrl);
 		return;
 	}
 
@@ -2213,7 +2221,7 @@ static void nvme_reset_ctrl_work(struct work_struct *work)
 static void nvme_tcp_stop_ctrl(struct nvme_ctrl *ctrl)
 {
 	flush_work(&to_tcp_ctrl(ctrl)->err_work);
-	cancel_delayed_work_sync(&to_tcp_ctrl(ctrl)->connect_work);
+	flush_delayed_work(&to_tcp_ctrl(ctrl)->connect_work);
 }
 
 static void nvme_tcp_free_ctrl(struct nvme_ctrl *nctrl)
-- 
2.25.1