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nvme-rdma: fix controller reset hang during traffic 

[ Upstream commit 9f98772ba3 ]

commit fe35ec58f0 ("block: update hctx map when use multiple maps")
exposed an issue where we may hang trying to wait for queue freeze
during I/O. We call blk_mq_update_nr_hw_queues which in case of multiple
queue maps (which we have now for default/read/poll) is attempting to
freeze the queue. However we never started queue freeze when starting the
reset, which means that we have inflight pending requests that entered the
queue that we will not complete once the queue is quiesced.

So start a freeze before we quiesce the queue, and unfreeze the queue
after we successfully connected the I/O queues (and make sure to call
blk_mq_update_nr_hw_queues only after we are sure that the queue was
already frozen).

This follows to how the pci driver handles resets.

Fixes: fe35ec58f0 ("block: update hctx map when use multiple maps")
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
5.4-rM2-2.2.x-imx-squashed
Sagi Grimberg 2020-07-27 17:32:09 -07:00 committed by Greg Kroah-Hartman
parent b98a96662a
commit 4e8691ba0e
1 changed files with 9 additions and 3 deletions
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12
drivers/nvme/host/rdma.c
View File

@ -890,15 +890,20 @@ static int nvme_rdma_configure_io_queues(struct nvme_rdma_ctrl *ctrl, bool new)
ret = PTR_ERR(ctrl->ctrl.connect_q);
goto out_free_tag_set;
}
} else {
blk_mq_update_nr_hw_queues(&ctrl->tag_set,
ctrl->ctrl.queue_count - 1);
}
ret = nvme_rdma_start_io_queues(ctrl);
if (ret)
goto out_cleanup_connect_q;
if (!new) {
nvme_start_queues(&ctrl->ctrl);
nvme_wait_freeze(&ctrl->ctrl);
blk_mq_update_nr_hw_queues(ctrl->ctrl.tagset,
ctrl->ctrl.queue_count - 1);
nvme_unfreeze(&ctrl->ctrl);
}
return 0;
out_cleanup_connect_q:
@ -931,6 +936,7 @@ 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_rdma_stop_io_queues(ctrl);
if (ctrl->ctrl.tagset) {