[PATCH] nvmet-tcp: Add a multex lock to start_queue failure case

[PATCH] nvmet-tcp: Add a multex lock to start_queue failure case

[amit.engel]

From: Amit Engel <amit.engel@dell.com>

this is in order to serialize nvme_tcp_stop_queue

Signed-off-by: Amit Engel <amit.engel@dell.com>
---
 drivers/nvme/host/tcp.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/nvme/host/tcp.c b/drivers/nvme/host/tcp.c
index 6a65b0516180..091f861c2067 100644
--- a/drivers/nvme/host/tcp.c
+++ b/drivers/nvme/host/tcp.c
@@ -1571,6 +1571,7 @@ static void nvme_tcp_stop_queue(struct nvme_ctrl *nctrl, int qid)
 static int nvme_tcp_start_queue(struct nvme_ctrl *nctrl, int idx)
 {
 	struct nvme_tcp_ctrl *ctrl = to_tcp_ctrl(nctrl);
+	struct nvme_tcp_queue *queue = &ctrl->queues[idx];
 	int ret;
 
 	if (idx)
@@ -1579,10 +1580,12 @@ static int nvme_tcp_start_queue(struct nvme_ctrl *nctrl, int idx)
 		ret = nvmf_connect_admin_queue(nctrl);
 
 	if (!ret) {
-		set_bit(NVME_TCP_Q_LIVE, &ctrl->queues[idx].flags);
+		set_bit(NVME_TCP_Q_LIVE, &queue->flags);
 	} else {
-		if (test_bit(NVME_TCP_Q_ALLOCATED, &ctrl->queues[idx].flags))
-			__nvme_tcp_stop_queue(&ctrl->queues[idx]);
+		mutex_lock(&queue->queue_lock);
+		if (test_bit(NVME_TCP_Q_ALLOCATED, &queue->flags))
+			__nvme_tcp_stop_queue(queue);
+		mutex_unlock(&queue->queue_lock);
 		dev_err(nctrl->device,
 			"failed to connect queue: %d ret=%d\n", idx, ret);
 	}
-- 
2.18.2


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Re: [PATCH] nvmet-tcp: Add a multex lock to start_queue failure case

[Sagi Grimberg]

> From: Amit Engel <amit.engel@dell.com>
> 
> this is in order to serialize nvme_tcp_stop_queue

Thinking about this, I don't think this is needed, can you describe
what is the scenario that requires this protection?

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