Commit 99dc2640 authored by Ming Lei's avatar Ming Lei Committed by Keith Busch
Browse files

nvme-tcp: fix potential unbalanced freeze & unfreeze 



Move start_freeze into nvme_tcp_configure_io_queues(), and there is
at least two benefits:

1) fix unbalanced freeze and unfreeze, since re-connection work may
fail or be broken by removal

2) IO during error recovery can be failfast quickly because nvme fabrics
unquiesces queues after teardown.

One side-effect is that !mpath request may timeout during connecting
because of queue topo change, but that looks not one big deal:

1) same problem exists with current code base

2) compared with !mpath, mpath use case is dominant

Fixes: 2875b0ae ("nvme-tcp: fix controller reset hang during traffic")
Cc: stable@vger.kernel.org
Signed-off-by: default avatarMing Lei <ming.lei@redhat.com>
Tested-by: default avatarYi Zhang <yi.zhang@redhat.com>
Reviewed-by: default avatarSagi Grimberg <sagi@grimberg.me>
Signed-off-by: default avatarKeith Busch <kbusch@kernel.org>
parent 1b95e817

drivers/nvme/host/tcp.c

+2 −1
Original line number Diff line number Diff line
@@ -1868,6 +1868,7 @@ static int nvme_tcp_configure_io_queues(struct nvme_ctrl *ctrl, bool new) 
		goto out_cleanup_connect_q;



	if (!new) {

		nvme_start_freeze(ctrl);

		nvme_unquiesce_io_queues(ctrl);

		if (!nvme_wait_freeze_timeout(ctrl, NVME_IO_TIMEOUT)) {

			/*
@@ -1876,6 +1877,7 @@ static int nvme_tcp_configure_io_queues(struct nvme_ctrl *ctrl, bool new) 
			 * to be safe.

			 */

			ret = -ENODEV;

			nvme_unfreeze(ctrl);

			goto out_wait_freeze_timed_out;

		}

		blk_mq_update_nr_hw_queues(ctrl->tagset,
@@ -1980,7 +1982,6 @@ static void nvme_tcp_teardown_io_queues(struct nvme_ctrl *ctrl, 
	if (ctrl->queue_count <= 1)

		return;

	nvme_quiesce_admin_queue(ctrl);

	nvme_start_freeze(ctrl);

	nvme_quiesce_io_queues(ctrl);

	nvme_sync_io_queues(ctrl);

	nvme_tcp_stop_io_queues(ctrl);