nvme-rdma: fix potential unbalanced freeze & unfreeze

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>

diff --git a/drivers/nvme/host/rdma.c b/drivers/nvme/host/rdma.c
index d433b2e..337a624 100644 (file)
--- a/drivers/nvme/host/rdma.c
+++ b/drivers/nvme/host/rdma.c
@@ -883,6 +883,7 @@ static int nvme_rdma_configure_io_queues(struct nvme_rdma_ctrl *ctrl, bool new)
                goto out_cleanup_tagset;
 
        if (!new) {
+               nvme_start_freeze(&ctrl->ctrl);
                nvme_unquiesce_io_queues(&ctrl->ctrl);
                if (!nvme_wait_freeze_timeout(&ctrl->ctrl, NVME_IO_TIMEOUT)) {
                        /*
@@ -891,6 +892,7 @@ 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,
@@ -940,7 +942,6 @@ 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_quiesce_io_queues(&ctrl->ctrl);
                nvme_sync_io_queues(&ctrl->ctrl);
                nvme_rdma_stop_io_queues(ctrl);