From: Sagi Grimberg <sagi@grimberg.me>
Date: Thu, 30 Jul 2020 13:42:42 -0700
Subject: [PATCH] nvme-rdma: fix reset hang if controller died in the middle of
 a reset
Patch-mainline: v5.9-rc4
Git-commit: 2362acb6785611eda795bfc12e1ea6b202ecf62c
References: bsc#1181161

If the controller becomes unresponsive in the middle of a reset, we
will hang because we are waiting for the freeze to complete, but that
cannot happen since we have commands that are inflight holding the
q_usage_counter, and we can't blindly fail requests that times out.

So give a timeout and if we cannot wait for queue freeze before
unfreezing, fail and have the error handling take care how to
proceed (either schedule a reconnect of remove the controller).

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Acked-by: Enzo Matsumiya <ematsumiya@suse.de>
---
 drivers/nvme/host/rdma.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/drivers/nvme/host/rdma.c b/drivers/nvme/host/rdma.c
index cb8731f4b316..1d8ea5305d60 100644
--- a/drivers/nvme/host/rdma.c
+++ b/drivers/nvme/host/rdma.c
@@ -976,7 +976,15 @@ static int nvme_rdma_configure_io_queues(struct nvme_rdma_ctrl *ctrl, bool new)
 
 	if (!new) {
 		nvme_start_queues(&ctrl->ctrl);
-		nvme_wait_freeze(&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);
@@ -984,6 +992,9 @@ 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_rdma_stop_io_queues(ctrl);
 out_cleanup_connect_q:
 	if (new)
 		blk_cleanup_queue(ctrl->ctrl.connect_q);
-- 
2.26.2