[PATCH AUTOSEL 6.12 23/28] nvmet-rdma: recheck queue state is LIVE in state lock in recv done

Sasha Levin
2025-02-24T11:19:05Z

From: Ruozhu Li <david.li@jaguarmicro.com>

[ Upstream commit 3988ac1c67e6e84d2feb987d7b36d5791174b3da ]

The queue state checking in nvmet_rdma_recv_done is not in queue state
lock.Queue state can transfer to LIVE in cm establish handler between
state checking and state lock here, cause a silent drop of nvme connect
cmd.
Recheck queue state whether in LIVE state in state lock to prevent this
issue.

Signed-off-by: Ruozhu Li <david.li@jaguarmicro.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/nvme/target/rdma.c | 33 +++++++++++++++++++++++----------
1 file changed, 23 insertions(+), 10 deletions(-)

diff --git a/drivers/nvme/target/rdma.c b/drivers/nvme/target/rdma.c
index 1afd93026f9bf..2a4536ef61848 100644
--- a/drivers/nvme/target/rdma.c
+++ b/drivers/nvme/target/rdma.c
@@ -996,6 +996,27 @@ static void nvmet_rdma_handle_command(struct nvmet_rdma_queue *queue,
nvmet_req_complete(&cmd->req, status);
}

+static bool nvmet_rdma_recv_not_live(struct nvmet_rdma_queue *queue,
+ struct nvmet_rdma_rsp *rsp)
+{
+ unsigned long flags;
+ bool ret = true;
+
+ spin_lock_irqsave(&queue->state_lock, flags);
+ /*
+ * recheck queue state is not live to prevent a race condition
+ * with RDMA_CM_EVENT_ESTABLISHED handler.
+ */
+ if (queue->state == NVMET_RDMA_Q_LIVE)
+ ret = false;
+ else if (queue->state == NVMET_RDMA_Q_CONNECTING)
+ list_add_tail(&rsp->wait_list, &queue->rsp_wait_list);
+ else
+ nvmet_rdma_put_rsp(rsp);
+ spin_unlock_irqrestore(&queue->state_lock, flags);
+ return ret;
+}
+
static void nvmet_rdma_recv_done(struct ib_cq *cq, struct ib_wc *wc)
{
struct nvmet_rdma_cmd *cmd =
@@ -1038,17 +1059,9 @@ static void nvmet_rdma_recv_done(struct ib_cq *cq, struct ib_wc *wc)
rsp->n_rdma = 0;
rsp->invalidate_rkey = 0;

- if (unlikely(queue->state != NVMET_RDMA_Q_LIVE)) {
- unsigned long flags;
-
- spin_lock_irqsave(&queue->state_lock, flags);
- if (queue->state == NVMET_RDMA_Q_CONNECTING)
- list_add_tail(&rsp->wait_list, &queue->rsp_wait_list);
- else
- nvmet_rdma_put_rsp(rsp);
- spin_unlock_irqrestore(&queue->state_lock, flags);
+ if (unlikely(queue->state != NVMET_RDMA_Q_LIVE) &&
+ nvmet_rdma_recv_not_live(queue, rsp))
return;
- }

nvmet_rdma_handle_command(queue, rsp);
}
--
2.39.5