[PATCH] nvme: don't wait freeze during resetting

[Ming Lei]

First it isn't necessary to call nvme_wait_freeze during reset.
For nvme-pci, if tagset isn't allocated, there can't be any inflight
IOs; otherwise blk_mq_update_nr_hw_queues can freeze & wait queues.

Second, since commit bdd6316094e0 ("block: Allow unfreezing of a queue
while requests are in progress"), it is fine to unfreeze queue without
draining inflight IOs.

Also both nvme-rdma and nvme-tcp's timeout handler provides forward
progress if the controller state isn't LIVE, so it is fine to drop
the timeout function of nvme_wait_freeze_timeout().

Cc: Sagi Grimberg <sagi at grimberg.me>
Cc: Chao Leng <lengchao at huawei.com>
Cc: Keith Busch <kbusch at kernel.org>
Signed-off-by: Ming Lei <ming.lei at redhat.com>
---
 drivers/nvme/host/apple.c |  1 -
 drivers/nvme/host/pci.c   |  1 -
 drivers/nvme/host/rdma.c  | 13 -------------
 drivers/nvme/host/tcp.c   | 13 -------------
 4 files changed, 28 deletions(-)

diff --git a/drivers/nvme/host/apple.c b/drivers/nvme/host/apple.c
index 5fc5ea196b40..9cd02b57fc85 100644
--- a/drivers/nvme/host/apple.c
+++ b/drivers/nvme/host/apple.c
@@ -1126,7 +1126,6 @@ static void apple_nvme_reset_work(struct work_struct *work)
 	anv->ctrl.queue_count = nr_io_queues + 1;
 
 	nvme_start_queues(&anv->ctrl);
-	nvme_wait_freeze(&anv->ctrl);
 	blk_mq_update_nr_hw_queues(&anv->tagset, 1);
 	nvme_unfreeze(&anv->ctrl);
 
diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index 98864b853eef..985b216907fc 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -2910,7 +2910,6 @@ static void nvme_reset_work(struct work_struct *work)
 		nvme_free_tagset(dev);
 	} else {
 		nvme_start_queues(&dev->ctrl);
-		nvme_wait_freeze(&dev->ctrl);
 		if (!dev->ctrl.tagset)
 			nvme_pci_alloc_tag_set(dev);
 		else
diff --git a/drivers/nvme/host/rdma.c b/drivers/nvme/host/rdma.c
index 3100643be299..beb0d1a6a84d 100644
--- a/drivers/nvme/host/rdma.c
+++ b/drivers/nvme/host/rdma.c
@@ -986,15 +986,6 @@ static int nvme_rdma_configure_io_queues(struct nvme_rdma_ctrl *ctrl, bool new)
 
 	if (!new) {
 		nvme_start_queues(&ctrl->ctrl);
-		if (!nvme_wait_freeze_timeout(&ctrl->ctrl, NVME_IO_TIMEOUT)) {
-			/*
-			 * If we timed out waiting for freeze we are likely to
-			 * be stuck.  Fail the controller initialization just
-			 * to be safe.
-			 */
-			ret = -ENODEV;
-			goto out_wait_freeze_timed_out;
-		}
 		blk_mq_update_nr_hw_queues(ctrl->ctrl.tagset,
 			ctrl->ctrl.queue_count - 1);
 		nvme_unfreeze(&ctrl->ctrl);
@@ -1002,10 +993,6 @@ static int nvme_rdma_configure_io_queues(struct nvme_rdma_ctrl *ctrl, bool new)
 
 	return 0;
 
-out_wait_freeze_timed_out:
-	nvme_stop_queues(&ctrl->ctrl);
-	nvme_sync_io_queues(&ctrl->ctrl);
-	nvme_rdma_stop_io_queues(ctrl);
 out_cleanup_connect_q:
 	nvme_cancel_tagset(&ctrl->ctrl);
 	if (new)
diff --git a/drivers/nvme/host/tcp.c b/drivers/nvme/host/tcp.c
index d5871fd6f769..49d9bef806f9 100644
--- a/drivers/nvme/host/tcp.c
+++ b/drivers/nvme/host/tcp.c
@@ -1920,15 +1920,6 @@ static int nvme_tcp_configure_io_queues(struct nvme_ctrl *ctrl, bool new)
 
 	if (!new) {
 		nvme_start_queues(ctrl);
-		if (!nvme_wait_freeze_timeout(ctrl, NVME_IO_TIMEOUT)) {
-			/*
-			 * If we timed out waiting for freeze we are likely to
-			 * be stuck.  Fail the controller initialization just
-			 * to be safe.
-			 */
-			ret = -ENODEV;
-			goto out_wait_freeze_timed_out;
-		}
 		blk_mq_update_nr_hw_queues(ctrl->tagset,
 			ctrl->queue_count - 1);
 		nvme_unfreeze(ctrl);
@@ -1936,10 +1927,6 @@ static int nvme_tcp_configure_io_queues(struct nvme_ctrl *ctrl, bool new)
 
 	return 0;
 
-out_wait_freeze_timed_out:
-	nvme_stop_queues(ctrl);
-	nvme_sync_io_queues(ctrl);
-	nvme_tcp_stop_io_queues(ctrl);
 out_cleanup_connect_q:
 	nvme_cancel_tagset(ctrl);
 	if (new)
-- 
2.31.1