Commit 137e25f0 authored Jul 11, 2023 by Ming Lei Committed by Greg Kroah-Hartman Aug 16, 2023

nvme-rdma: fix potential unbalanced freeze & unfreeze



commit 29b434d1e49252b3ad56ad3197e47fafff5356a1 upstream.

Move start_freeze into nvme_rdma_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: 9f98772ba307 ("nvme-rdma: fix controller reset hang during traffic")
Cc: stable@vger.kernel.org
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Tested-by: Yi Zhang <yi.zhang@redhat.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent ab32fbe3

drivers/nvme/host/rdma.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -905,6 +905,7 @@ static int nvme_rdma_configure_io_queues(struct nvme_rdma_ctrl *ctrl, bool new)
		goto out_cleanup_connect_q;

		if (!new) {
		nvme_start_freeze(&ctrl->ctrl);
		nvme_start_queues(&ctrl->ctrl);
		if (!nvme_wait_freeze_timeout(&ctrl->ctrl, NVME_IO_TIMEOUT)) {
		/*
		@@ -913,6 +914,7 @@ static int nvme_rdma_configure_io_queues(struct nvme_rdma_ctrl *ctrl, bool new)
		* to be safe.
		*/
		ret = -ENODEV;
		nvme_unfreeze(&ctrl->ctrl);
		goto out_wait_freeze_timed_out;
		}
		blk_mq_update_nr_hw_queues(ctrl->ctrl.tagset,
		@@ -958,7 +960,6 @@ static void nvme_rdma_teardown_io_queues(struct nvme_rdma_ctrl *ctrl,
		bool remove)
		{
		if (ctrl->ctrl.queue_count > 1) {
		nvme_start_freeze(&ctrl->ctrl);
		nvme_stop_queues(&ctrl->ctrl);
		nvme_sync_io_queues(&ctrl->ctrl);
		nvme_rdma_stop_io_queues(ctrl);