[PATCH 7/9] block: assign batch completion handler in blk_poll()

[Jens Axboe <axboe@kernel.dk>]

If an io_batch is passed in to blk_poll(), we need to assign the batch
handler associated with this queue. This allows callers to complete
an io_batch handler on by calling it.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
 block/blk-mq.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/block/blk-mq.c b/block/blk-mq.c
index d603703cf272..deafd444761d 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -4302,6 +4302,19 @@ static int blk_mq_poll_classic(struct request_queue *q, blk_qc_t cookie,
 
 	hctx->poll_considered++;
 
+	/*
+	 * If batching is requested but the target doesn't support batched
+	 * completions, then just clear ib and completions will be handled
+	 * normally.
+	 */
+	if (iob) {
+		iob->complete = q->mq_ops->complete_batch;
+		if (!iob->complete) {
+			WARN_ON_ONCE(iob->req_list);
+			iob = NULL;
+		}
+	}
+
 	do {
 		hctx->poll_invoked++;
 
-- 
2.33.0