From b583faf4dc6eaa64895c37b81983e75a8c3c1e4e Mon Sep 17 00:00:00 2001 From: Jianxin Xiong Date: Thu, 19 May 2016 05:21:57 -0700 Subject: [PATCH] IB/hfi1: Fix bug that blocks process on exit after port bounce During the processing of a user SDMA request, if there was an error before the request counter was increased, the state of the packet queue could be updated incorrectly, causing the counter to underflow. As the result, the process could get stuck later since the counter could never get back to 0. This patch adds a condition to guard the packet queue update so that the counter is only decreased if it has been increased before the error happens. Reviewed-by: Mitko Haralanov Signed-off-by: Jianxin Xiong Signed-off-by: Doug Ledford --- drivers/staging/rdma/hfi1/user_sdma.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/staging/rdma/hfi1/user_sdma.c b/drivers/staging/rdma/hfi1/user_sdma.c index aed2878c97f1..29f4795f866c 100644 --- a/drivers/staging/rdma/hfi1/user_sdma.c +++ b/drivers/staging/rdma/hfi1/user_sdma.c @@ -510,6 +510,7 @@ int hfi1_user_sdma_process_request(struct file *fp, struct iovec *iovec, struct sdma_req_info info; struct user_sdma_request *req; u8 opcode, sc, vl; + int req_queued = 0; if (iovec[idx].iov_len < sizeof(info) + sizeof(req->hdr)) { hfi1_cdbg( @@ -706,6 +707,7 @@ int hfi1_user_sdma_process_request(struct file *fp, struct iovec *iovec, set_comp_state(pq, cq, info.comp_idx, QUEUED, 0); atomic_inc(&pq->n_reqs); + req_queued = 1; /* Send the first N packets in the request to buy us some time */ ret = user_sdma_send_pkts(req, pcount); if (unlikely(ret < 0 && ret != -EBUSY)) { @@ -750,7 +752,8 @@ int hfi1_user_sdma_process_request(struct file *fp, struct iovec *iovec, return 0; free_req: user_sdma_free_request(req, true); - pq_update(pq); + if (req_queued) + pq_update(pq); set_comp_state(pq, cq, info.comp_idx, ERROR, req->status); return ret; } -- 2.39.2