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 <ax...@kernel.dk>
---
block/blk-core.c | 2 +-
block/blk-mq.c | 71 ++++++++++++++++++++--------------------
drivers/nvme/host/pci.c | 14 ++++----
drivers/nvme/host/rdma.c | 39 +++++++++-------------
include/linux/blkdev.h | 2 +-
5 files changed, 60 insertions(+), 68 deletions(-)
diff --git a/block/blk-core.c b/block/blk-core.c
index 04f5be473638..9e99aa852d6e 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1273,7 +1273,7 @@ blk_qc_t submit_bio(struct bio *bio)
}
EXPORT_SYMBOL(submit_bio);
-bool blk_poll(struct request_queue *q, blk_qc_t cookie)
+int blk_poll(struct request_queue *q, blk_qc_t cookie)
{
if (!q->poll_fn || !blk_qc_t_valid(cookie))
return false;
diff --git a/block/blk-mq.c b/block/blk-mq.c
index b16204df65d1..ec6c79578332 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -3285,15 +3285,12 @@ static bool blk_mq_poll_hybrid_sleep(struct
request_queue *q,
return false;
/*
- * poll_nsec can be:
+ * If we get here, hybrid polling is enabled. Hence poll_nsec can be:
*
- * -1: don't ever hybrid sleep
* 0: use half of prev avg
* >0: use this specific value
*/
- if (q->poll_nsec == -1)
- return false;
- else if (q->poll_nsec > 0)
+ if (q->poll_nsec > 0)
nsecs = q->poll_nsec;
else
nsecs = blk_mq_poll_nsecs(q, hctx, rq);
@@ -3330,11 +3327,41 @@ static bool blk_mq_poll_hybrid_sleep(struct
request_queue *q,
return true;
}
-static int __blk_mq_poll(struct blk_mq_hw_ctx *hctx, struct request *rq)
+static bool blk_mq_poll_hybrid(struct request_queue *q,
+ struct blk_mq_hw_ctx *hctx, blk_qc_t cookie)
{
- struct request_queue *q = hctx->queue;
+ struct request *rq;
+
+ if (q->poll_nsec == -1)
+ return false;
+
+ if (!blk_qc_t_is_internal(cookie))
+ rq = blk_mq_tag_to_rq(hctx->tags, blk_qc_t_to_tag(cookie));
+ else {
+ rq = blk_mq_tag_to_rq(hctx->sched_tags,
blk_qc_t_to_tag(cookie));
+ /*
+ * With scheduling, if the request has completed, we'll
+ * get a NULL return here, as we clear the sched tag when
+ * that happens. The request still remains valid, like always,
+ * so we should be safe with just the NULL check.
+ */
+ if (!rq)
+ return false;
+ }
+
+ return blk_mq_poll_hybrid_sleep(q, hctx, rq);
+}
+
+static int blk_mq_poll(struct request_queue *q, blk_qc_t cookie)
+{
+ struct blk_mq_hw_ctx *hctx;
long state;
+ if (!test_bit(QUEUE_FLAG_POLL, &q->queue_flags))
+ return 0;
+
+ hctx = q->queue_hw_ctx[blk_qc_t_to_queue_num(cookie)];
+
/*
* If we sleep, have the caller restart the poll loop to reset
* the state. Like for the other success return cases, the
@@ -3342,7 +3369,7 @@ static int __blk_mq_poll(struct blk_mq_hw_ctx *hctx,
struct request *rq)
* the IO isn't complete, we'll get called again and will go
* straight to the busy poll loop.
*/
- if (blk_mq_poll_hybrid_sleep(q, hctx, rq))
+ if (blk_mq_poll_hybrid(q, hctx, cookie))
return 1;
hctx->poll_considered++;
@@ -3353,7 +3380,7 @@ static int __blk_mq_poll(struct blk_mq_hw_ctx *hctx,
struct request *rq)
hctx->poll_invoked++;
- ret = q->mq_ops->poll(hctx, rq->tag);
+ ret = q->mq_ops->poll(hctx, -1U);
if (ret > 0) {
hctx->poll_success++;
__set_current_state(TASK_RUNNING);
@@ -3374,32 +3401,6 @@ static int __blk_mq_poll(struct blk_mq_hw_ctx *hctx,
struct request *rq)
return 0;
}
-static int blk_mq_poll(struct request_queue *q, blk_qc_t cookie)
-{
- struct blk_mq_hw_ctx *hctx;
- struct request *rq;
-
- if (!test_bit(QUEUE_FLAG_POLL, &q->queue_flags))
- return 0;
-
- hctx = q->queue_hw_ctx[blk_qc_t_to_queue_num(cookie)];
- if (!blk_qc_t_is_internal(cookie))
- rq = blk_mq_tag_to_rq(hctx->tags, blk_qc_t_to_tag(cookie));
- else {
- rq = blk_mq_tag_to_rq(hctx->sched_tags,
blk_qc_t_to_tag(cookie));
- /*
- * With scheduling, if the request has completed, we'll
- * get a NULL return here, as we clear the sched tag when
- * that happens. The request still remains valid, like always,
- * so we should be safe with just the NULL check.
- */
- if (!rq)
- return 0;
- }
-
- return __blk_mq_poll(hctx, rq);
-}
-
unsigned int blk_mq_rq_cpu(struct request *rq)
{
return rq->mq_ctx->cpu;
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);
+ }
}
}
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 9b53db06ad08..f3015e9b5ae3 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -867,7 +867,7 @@ extern void blk_execute_rq_nowait(struct request_queue *,
struct gendisk *,
int blk_status_to_errno(blk_status_t status);
blk_status_t errno_to_blk_status(int errno);
-bool blk_poll(struct request_queue *q, blk_qc_t cookie);
+int blk_poll(struct request_queue *q, blk_qc_t cookie);
static inline struct request_queue *bdev_get_queue(struct block_device *bdev)
{
--
2.17.1
