blk-mq: when polling for IO, look for any completion

If we want to support async IO polling, then we have to allow finding
completions that aren't just for the one we are looking for. Always pass
in -1 to the mq_ops->poll() helper, and have that return how many events
were found in this poll loop.

Signed-off-by: Jens Axboe <axboe@kernel.dk>

2 files changed, 22 insertions, 31 deletions

diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index 57e790391b82..de50d80ecc84 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -1012,15 +1012,15 @@ static inline void nvme_update_cq_head(struct nvme_queue *nvmeq)
 	}
 }
 
-static inline bool nvme_process_cq(struct nvme_queue *nvmeq, u16 *start,
-		u16 *end, int tag)
+static inline int nvme_process_cq(struct nvme_queue *nvmeq, u16 *start,
+				  u16 *end, unsigned int tag)
 {
-	bool found = false;
+	int found = 0;
 
 	*start = nvmeq->cq_head;
-	while (!found && nvme_cqe_pending(nvmeq)) {
-		if (nvmeq->cqes[nvmeq->cq_head].command_id == tag)
-			found = true;
+	while (nvme_cqe_pending(nvmeq)) {
+		if (tag == -1U || nvmeq->cqes[nvmeq->cq_head].command_id == tag)
+			found++;
 		nvme_update_cq_head(nvmeq);
 	}
 	*end = nvmeq->cq_head;
@@ -1062,7 +1062,7 @@ static irqreturn_t nvme_irq_check(int irq, void *data)
 static int __nvme_poll(struct nvme_queue *nvmeq, unsigned int tag)
 {
 	u16 start, end;
-	bool found;
+	int found;
 
 	if (!nvme_cqe_pending(nvmeq))
 		return 0;
diff --git a/drivers/nvme/host/rdma.c b/drivers/nvme/host/rdma.c
index d181cafedc58..c2c3e1a5b7af 100644
--- a/drivers/nvme/host/rdma.c
+++ b/drivers/nvme/host/rdma.c
@@ -1409,12 +1409,11 @@ static void nvme_rdma_submit_async_event(struct nvme_ctrl *arg)
 	WARN_ON_ONCE(ret);
 }
 
-static int nvme_rdma_process_nvme_rsp(struct nvme_rdma_queue *queue,
-		struct nvme_completion *cqe, struct ib_wc *wc, int tag)
+static void nvme_rdma_process_nvme_rsp(struct nvme_rdma_queue *queue,
+		struct nvme_completion *cqe, struct ib_wc *wc)
 {
 	struct request *rq;
 	struct nvme_rdma_request *req;
-	int ret = 0;
 
 	rq = blk_mq_tag_to_rq(nvme_rdma_tagset(queue), cqe->command_id);
 	if (!rq) {
@@ -1422,7 +1421,7 @@ static int nvme_rdma_process_nvme_rsp(struct nvme_rdma_queue *queue,
 			"tag 0x%x on QP %#x not found\n",
 			cqe->command_id, queue->qp->qp_num);
 		nvme_rdma_error_recovery(queue->ctrl);
-		return ret;
+		return;
 	}
 	req = blk_mq_rq_to_pdu(rq);
 
@@ -1437,6 +1436,8 @@ static int nvme_rdma_process_nvme_rsp(struct nvme_rdma_queue *queue,
 			nvme_rdma_error_recovery(queue->ctrl);
 		}
 	} else if (req->mr) {
+		int ret;
+
 		ret = nvme_rdma_inv_rkey(queue, req);
 		if (unlikely(ret < 0)) {
 			dev_err(queue->ctrl->ctrl.device,
@@ -1445,19 +1446,14 @@ static int nvme_rdma_process_nvme_rsp(struct nvme_rdma_queue *queue,
 			nvme_rdma_error_recovery(queue->ctrl);
 		}
 		/* the local invalidation completion will end the request */
-		return 0;
+		return;
 	}
 
-	if (refcount_dec_and_test(&req->ref)) {
-		if (rq->tag == tag)
-			ret = 1;
+	if (refcount_dec_and_test(&req->ref))
 		nvme_end_request(rq, req->status, req->result);
-	}
-
-	return ret;
 }
 
-static int __nvme_rdma_recv_done(struct ib_cq *cq, struct ib_wc *wc, int tag)
+static void nvme_rdma_recv_done(struct ib_cq *cq, struct ib_wc *wc)
 {
 	struct nvme_rdma_qe *qe =
 		container_of(wc->wr_cqe, struct nvme_rdma_qe, cqe);
@@ -1465,11 +1461,10 @@ static int __nvme_rdma_recv_done(struct ib_cq *cq, struct ib_wc *wc, int tag)
 	struct ib_device *ibdev = queue->device->dev;
 	struct nvme_completion *cqe = qe->data;
 	const size_t len = sizeof(struct nvme_completion);
-	int ret = 0;
 
 	if (unlikely(wc->status != IB_WC_SUCCESS)) {
 		nvme_rdma_wr_error(cq, wc, "RECV");
-		return 0;
+		return;
 	}
 
 	ib_dma_sync_single_for_cpu(ibdev, qe->dma, len, DMA_FROM_DEVICE);
@@ -1484,16 +1479,10 @@ static int __nvme_rdma_recv_done(struct ib_cq *cq, struct ib_wc *wc, int tag)
 		nvme_complete_async_event(&queue->ctrl->ctrl, cqe->status,
 				&cqe->result);
 	else
-		ret = nvme_rdma_process_nvme_rsp(queue, cqe, wc, tag);
+		nvme_rdma_process_nvme_rsp(queue, cqe, wc);
 	ib_dma_sync_single_for_device(ibdev, qe->dma, len, DMA_FROM_DEVICE);
 
 	nvme_rdma_post_recv(queue, qe);
-	return ret;
-}
-
-static void nvme_rdma_recv_done(struct ib_cq *cq, struct ib_wc *wc)
-{
-	__nvme_rdma_recv_done(cq, wc, -1);
 }
 
 static int nvme_rdma_conn_established(struct nvme_rdma_queue *queue)
@@ -1758,10 +1747,12 @@ static int nvme_rdma_poll(struct blk_mq_hw_ctx *hctx, unsigned int tag)
 		struct ib_cqe *cqe = wc.wr_cqe;
 
 		if (cqe) {
-			if (cqe->done == nvme_rdma_recv_done)
-				found |= __nvme_rdma_recv_done(cq, &wc, tag);
-			else
+			if (cqe->done == nvme_rdma_recv_done) {
+				nvme_rdma_recv_done(cq, &wc);
+				found++;
+			} else {
 				cqe->done(cq, &wc);
+			}
 		}
 	}