From: Sagi Grimberg <sagi@grimberg.me>
Date: Thu, 23 Nov 2017 17:35:23 +0200
Subject: nvme-rdma: wait for local invalidation before completing a request
Patch-mainline: v4.15-rc2
Git-commit: 2f122e4f5107cf8ab0e592d63ed816a00110b4fe
References: FATE#323952, FATE#322506

We must not complete a request before the host memory region is
invalidated.  Luckily we have send with invalidate protocol support so
we usually don't need to execute it, but in case the target did not
invalidate a memory region for us, we must wait for the invalidation to
complete before unmapping host memory and completing the I/O.

Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Johannes Thumshirn <jthumshirn@suse.de>
---
 drivers/nvme/host/rdma.c |   39 ++++++++++++++++++++++++---------------
 1 file changed, 24 insertions(+), 15 deletions(-)

--- a/drivers/nvme/host/rdma.c
+++ b/drivers/nvme/host/rdma.c
@@ -1019,8 +1019,18 @@ static void nvme_rdma_memreg_done(struct
 
 static void nvme_rdma_inv_rkey_done(struct ib_cq *cq, struct ib_wc *wc)
 {
-	if (unlikely(wc->status != IB_WC_SUCCESS))
+	struct nvme_rdma_request *req =
+		container_of(wc->wr_cqe, struct nvme_rdma_request, reg_cqe);
+	struct request *rq = blk_mq_rq_from_pdu(req);
+
+	if (unlikely(wc->status != IB_WC_SUCCESS)) {
 		nvme_rdma_wr_error(cq, wc, "LOCAL_INV");
+		return;
+	}
+
+	if (refcount_dec_and_test(&req->ref))
+		nvme_end_request(rq, req->status, req->result);
+
 }
 
 static int nvme_rdma_inv_rkey(struct nvme_rdma_queue *queue,
@@ -1031,7 +1041,7 @@ static int nvme_rdma_inv_rkey(struct nvm
 		.opcode		    = IB_WR_LOCAL_INV,
 		.next		    = NULL,
 		.num_sge	    = 0,
-		.send_flags	    = 0,
+		.send_flags	    = IB_SEND_SIGNALED,
 		.ex.invalidate_rkey = req->mr->rkey,
 	};
 
@@ -1045,24 +1055,12 @@ static void nvme_rdma_unmap_data(struct
 		struct request *rq)
 {
 	struct nvme_rdma_request *req = blk_mq_rq_to_pdu(rq);
-	struct nvme_rdma_ctrl *ctrl = queue->ctrl;
 	struct nvme_rdma_device *dev = queue->device;
 	struct ib_device *ibdev = dev->dev;
-	int res;
 
 	if (!blk_rq_bytes(rq))
 		return;
 
-	if (req->mr->need_inval && test_bit(NVME_RDMA_Q_LIVE, &req->queue->flags)) {
-		res = nvme_rdma_inv_rkey(queue, req);
-		if (unlikely(res < 0)) {
-			dev_err(ctrl->ctrl.device,
-				"Queueing INV WR for rkey %#x failed (%d)\n",
-				req->mr->rkey, res);
-			nvme_rdma_error_recovery(queue->ctrl);
-		}
-	}
-
 	ib_dma_unmap_sg(ibdev, req->sg_table.sgl,
 			req->nents, rq_data_dir(rq) ==
 				    WRITE ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
@@ -1337,8 +1335,19 @@ static int nvme_rdma_process_nvme_rsp(st
 	req->result = cqe->result;
 
 	if ((wc->wc_flags & IB_WC_WITH_INVALIDATE) &&
-	    wc->ex.invalidate_rkey == req->mr->rkey)
+	    wc->ex.invalidate_rkey == req->mr->rkey) {
 		req->mr->need_inval = false;
+	} else if (req->mr->need_inval) {
+		ret = nvme_rdma_inv_rkey(queue, req);
+		if (unlikely(ret < 0)) {
+			dev_err(queue->ctrl->ctrl.device,
+				"Queueing INV WR for rkey %#x failed (%d)\n",
+				req->mr->rkey, ret);
+			nvme_rdma_error_recovery(queue->ctrl);
+		}
+		/* the local invalidation completion will end the request */
+		return 0;
+	}
 
 	if (refcount_dec_and_test(&req->ref)) {
 		if (rq->tag == tag)