5.4-stable review patch. If anyone has any objections, please let me know.
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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 ae41b6001c7e2..b6d84b6493e14 100644 --- a/drivers/nvme/target/rdma.c +++ b/drivers/nvme/target/rdma.c @@ -777,6 +777,27 @@ 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 = @@ -818,17 +839,9 @@ static void nvmet_rdma_recv_done(struct ib_cq *cq, struct ib_wc *wc) rsp->req.port = queue->port; rsp->n_rdma = 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); }