[PATCH 04/12] blk-mq: factor out a "classic" poll helper

[Christoph Hellwig <hch@xxxxxx>]

Factor the code to do the classic full metal polling out of blk_poll into
a separate blk_mq_poll_classic helper.

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
 block/blk-mq.c | 63 +++++++++++++++++++++++++++-----------------------
 1 file changed, 34 insertions(+), 29 deletions(-)

diff --git a/block/blk-mq.c b/block/blk-mq.c
index 927189a55575..4a72d3fa7964 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -3853,6 +3853,39 @@ static bool blk_mq_poll_hybrid(struct request_queue *q,
 	return blk_mq_poll_hybrid_sleep(q, rq);
 }
 
+static int blk_mq_poll_classic(struct request_queue *q, blk_qc_t qc, bool spin)
+{
+	struct blk_mq_hw_ctx *hctx = q->queue_hw_ctx[blk_qc_t_to_queue_num(qc)];
+	long state = current->state;
+
+	hctx->poll_considered++;
+
+	do {
+		int ret;
+
+		hctx->poll_invoked++;
+
+		ret = q->mq_ops->poll(hctx);
+		if (ret > 0) {
+			hctx->poll_success++;
+			__set_current_state(TASK_RUNNING);
+			return ret;
+		}
+
+		if (signal_pending_state(state, current))
+			__set_current_state(TASK_RUNNING);
+
+		if (current->state == TASK_RUNNING)
+			return 1;
+		if (ret < 0 || !spin)
+			break;
+		cpu_relax();
+	} while (!need_resched());
+
+	__set_current_state(TASK_RUNNING);
+	return 0;
+}
+
 /**
  * blk_poll - poll for IO completions
  * @q:  the queue
@@ -3868,7 +3901,6 @@ static bool blk_mq_poll_hybrid(struct request_queue *q,
 int blk_poll(struct request_queue *q, blk_qc_t cookie, bool spin)
 {
 	struct blk_mq_hw_ctx *hctx;
-	long state;
 
 	if (!blk_qc_t_valid(cookie) ||
 	    !test_bit(QUEUE_FLAG_POLL, &q->queue_flags))
@@ -3889,34 +3921,7 @@ int blk_poll(struct request_queue *q, blk_qc_t cookie, bool spin)
 	 */
 	if (spin && blk_mq_poll_hybrid(q, hctx, cookie))
 		return 1;
-
-	hctx->poll_considered++;
-
-	state = current->state;
-	do {
-		int ret;
-
-		hctx->poll_invoked++;
-
-		ret = q->mq_ops->poll(hctx);
-		if (ret > 0) {
-			hctx->poll_success++;
-			__set_current_state(TASK_RUNNING);
-			return ret;
-		}
-
-		if (signal_pending_state(state, current))
-			__set_current_state(TASK_RUNNING);
-
-		if (current->state == TASK_RUNNING)
-			return 1;
-		if (ret < 0 || !spin)
-			break;
-		cpu_relax();
-	} while (!need_resched());
-
-	__set_current_state(TASK_RUNNING);
-	return 0;
+	return blk_mq_poll_classic(q, cookie, spin);
 }
 EXPORT_SYMBOL_GPL(blk_poll);
 
-- 
2.30.1