From: Chao Leng <lengchao@huawei.com>
To: <linux-nvme@lists.infradead.org>
Cc: kbusch@kernel.org, axboe@fb.com, hch@lst.de, lengchao@huawei.com,
sagi@grimberg.me
Subject: [PATCH] nvme-rdma: fix deadlock when delete ctrl due to reconnect fail
Date: Mon, 27 Jul 2020 16:09:26 +0800 [thread overview]
Message-ID: <20200727080926.30776-1-lengchao@huawei.com> (raw)
A deadlock happens when test link blink for nvme over roce. If time out
in reconneting process, nvme_rdma_timeout->nvme_rdma_teardown_io_queues
will quiesce the io queues, and then the ctrl will be deleted after
reconnect times exceed max_reconnects. If run fdisk from the time
when the queue is quiesced to the time when the ctrl is deleted,
delete ctrl will deadlock, the process: nvme_do_delete_ctrl->
nvme_remove_namespaces->nvme_ns_remove->blk_cleanup_queue->
blk_freeze_queue->blk_mq_freeze_queue_wait, blk_mq_freeze_queue_wait
will wait until q_usage_counter of queue become 0, but the queue is
quiesced, can not clean any request.
Solution: nvme_rdma_timeout should call nvme_start_queues after
call nvme_rdma_teardown_io_queues. further more, we need start queues
regardless of whether the remove flag is set, after cancel requests
in nvme_rdma_teardown_io_queues.
Signed-off-by: Chao Leng <lengchao@huawei.com>
---
drivers/nvme/host/rdma.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/drivers/nvme/host/rdma.c b/drivers/nvme/host/rdma.c
index f8f856dc0c67..b381e2cde50a 100644
--- a/drivers/nvme/host/rdma.c
+++ b/drivers/nvme/host/rdma.c
@@ -989,8 +989,7 @@ static void nvme_rdma_teardown_io_queues(struct nvme_rdma_ctrl *ctrl,
nvme_cancel_request, &ctrl->ctrl);
blk_mq_tagset_wait_completed_request(ctrl->ctrl.tagset);
}
- if (remove)
- nvme_start_queues(&ctrl->ctrl);
+ nvme_start_queues(&ctrl->ctrl);
nvme_rdma_destroy_io_queues(ctrl, remove);
}
}
@@ -1128,7 +1127,6 @@ static void nvme_rdma_error_recovery_work(struct work_struct *work)
nvme_stop_keep_alive(&ctrl->ctrl);
nvme_rdma_teardown_io_queues(ctrl, false);
- nvme_start_queues(&ctrl->ctrl);
nvme_rdma_teardown_admin_queue(ctrl, false);
blk_mq_unquiesce_queue(ctrl->ctrl.admin_q);
--
2.16.4
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next reply other threads:[~2020-07-27 8:09 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-27 8:09 Chao Leng [this message]
2020-07-27 18:44 ` [PATCH] nvme-rdma: fix deadlock when delete ctrl due to reconnect fail Sagi Grimberg
2020-07-27 23:31 ` Sagi Grimberg
2020-07-28 3:06 ` Chao Leng
2020-07-28 3:32 ` Sagi Grimberg
[not found] ` <1288e338-9e92-eeeb-6f7b-86590c6e1a4c@broadcom.com>
2020-07-28 16:27 ` Sagi Grimberg
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