| Message ID | 20171120113101.8292-3-sagi@grimberg.me (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
On 11/20/2017 1:30 PM, Sagi Grimberg wrote: > In order to guarantee that the HCA will never get an access violation > (either from invalidated rkey or from iommu) when retrying a send > operation we must complete a request only when both send completion > and the nvme cqe has arrived. We need to set the send/recv completions > flags atomically because we might have more than a single context > accessing the request concurrently (one is cq irq-poll context and > the other is user-polling used in IOCB_HIPRI). > > Only then we are safe to invalidate the rkey (if needed), unmap > the host buffers, and complete the IO. > > Signed-off-by: Sagi Grimberg <sagi@grimberg.me> > --- > drivers/nvme/host/rdma.c | 28 ++++++++++++++++++++++++---- > 1 file changed, 24 insertions(+), 4 deletions(-) > > diff --git a/drivers/nvme/host/rdma.c b/drivers/nvme/host/rdma.c > index 85c98589a5e0..9202cfa9300b 100644 > --- a/drivers/nvme/host/rdma.c > +++ b/drivers/nvme/host/rdma.c > @@ -59,6 +59,9 @@ struct nvme_rdma_request { > struct nvme_request req; > struct ib_mr *mr; > struct nvme_rdma_qe sqe; > + union nvme_result result; > + __le16 status; > + refcount_t ref; > struct ib_sge sge[1 + NVME_RDMA_MAX_INLINE_SEGMENTS]; > u32 num_sge; > int nents; > @@ -1162,6 +1165,7 @@ static int nvme_rdma_map_data(struct nvme_rdma_queue *queue, > req->num_sge = 1; > req->inline_data = false; > req->mr->need_inval = false; > + refcount_set(&req->ref, 2); /* send and recv completions */ > > c->common.flags |= NVME_CMD_SGL_METABUF; > > @@ -1198,8 +1202,19 @@ static int nvme_rdma_map_data(struct nvme_rdma_queue *queue, > > static void nvme_rdma_send_done(struct ib_cq *cq, struct ib_wc *wc) > { > - if (unlikely(wc->status != IB_WC_SUCCESS)) > + struct nvme_rdma_qe *qe = > + container_of(wc->wr_cqe, struct nvme_rdma_qe, cqe); > + struct nvme_rdma_request *req = > + container_of(qe, struct nvme_rdma_request, sqe); what will happen if we get here from qe that belongs to async_event post_send request (completion with error ) ? the container_of will be wrong... > + struct request *rq = blk_mq_rq_from_pdu(req); > + > + if (unlikely(wc->status != IB_WC_SUCCESS)) { > nvme_rdma_wr_error(cq, wc, "SEND"); > + return; > + } > + > + if (refcount_dec_and_test(&req->ref)) > + nvme_end_request(rq, req->status, req->result); -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/nvme/host/rdma.c b/drivers/nvme/host/rdma.c index 85c98589a5e0..9202cfa9300b 100644 --- a/drivers/nvme/host/rdma.c +++ b/drivers/nvme/host/rdma.c @@ -59,6 +59,9 @@ struct nvme_rdma_request { struct nvme_request req; struct ib_mr *mr; struct nvme_rdma_qe sqe; + union nvme_result result; + __le16 status; + refcount_t ref; struct ib_sge sge[1 + NVME_RDMA_MAX_INLINE_SEGMENTS]; u32 num_sge; int nents; @@ -1162,6 +1165,7 @@ static int nvme_rdma_map_data(struct nvme_rdma_queue *queue, req->num_sge = 1; req->inline_data = false; req->mr->need_inval = false; + refcount_set(&req->ref, 2); /* send and recv completions */ c->common.flags |= NVME_CMD_SGL_METABUF; @@ -1198,8 +1202,19 @@ static int nvme_rdma_map_data(struct nvme_rdma_queue *queue, static void nvme_rdma_send_done(struct ib_cq *cq, struct ib_wc *wc) { - if (unlikely(wc->status != IB_WC_SUCCESS)) + struct nvme_rdma_qe *qe = + container_of(wc->wr_cqe, struct nvme_rdma_qe, cqe); + struct nvme_rdma_request *req = + container_of(qe, struct nvme_rdma_request, sqe); + struct request *rq = blk_mq_rq_from_pdu(req); + + if (unlikely(wc->status != IB_WC_SUCCESS)) { nvme_rdma_wr_error(cq, wc, "SEND"); + return; + } + + if (refcount_dec_and_test(&req->ref)) + nvme_end_request(rq, req->status, req->result); } static int nvme_rdma_post_send(struct nvme_rdma_queue *queue, @@ -1318,14 +1333,19 @@ static int nvme_rdma_process_nvme_rsp(struct nvme_rdma_queue *queue, } req = blk_mq_rq_to_pdu(rq); - if (rq->tag == tag) - ret = 1; + req->status = cqe->status; + req->result = cqe->result; if ((wc->wc_flags & IB_WC_WITH_INVALIDATE) && wc->ex.invalidate_rkey == req->mr->rkey) req->mr->need_inval = false; - nvme_end_request(rq, cqe->status, cqe->result); + if (refcount_dec_and_test(&req->ref)) { + if (rq->tag == tag) + ret = 1; + nvme_end_request(rq, req->status, req->result); + } + return ret; }
In order to guarantee that the HCA will never get an access violation (either from invalidated rkey or from iommu) when retrying a send operation we must complete a request only when both send completion and the nvme cqe has arrived. We need to set the send/recv completions flags atomically because we might have more than a single context accessing the request concurrently (one is cq irq-poll context and the other is user-polling used in IOCB_HIPRI). Only then we are safe to invalidate the rkey (if needed), unmap the host buffers, and complete the IO. Signed-off-by: Sagi Grimberg <sagi@grimberg.me> --- drivers/nvme/host/rdma.c | 28 ++++++++++++++++++++++++---- 1 file changed, 24 insertions(+), 4 deletions(-)