Used forsynchronous requests that needs polling. If we are knowingly
sending a request down to a poll queue, we need a synchronous interface
to poll for its completion.

Signed-off-by: Sagi Grimberg <[email protected]>
---
 block/blk-exec.c       | 29 +++++++++++++++++++++++++++++
 block/blk-mq.c         |  8 --------
 include/linux/blk-mq.h |  8 ++++++++
 include/linux/blkdev.h |  2 ++
 4 files changed, 39 insertions(+), 8 deletions(-)

diff --git a/block/blk-exec.c b/block/blk-exec.c
index a34b7d918742..572032d60001 100644
--- a/block/blk-exec.c
+++ b/block/blk-exec.c
@@ -90,3 +90,32 @@ void blk_execute_rq(struct request_queue *q, struct gendisk 
*bd_disk,
                wait_for_completion_io(&wait);
 }
 EXPORT_SYMBOL(blk_execute_rq);
+
+/**
+ * blk_execute_rq_polled - execute a request and poll for its completion
+ * @q:         queue to insert the request in
+ * @bd_disk:   matching gendisk
+ * @rq:                request to insert
+ * @at_head:    insert request at head or tail of queue
+ *
+ * Description:
+ *    Insert a fully prepared request at the back of the I/O scheduler queue
+ *    for execution and wait for completion.
+ */
+void blk_execute_rq_polled(struct request_queue *q, struct gendisk *bd_disk,
+                  struct request *rq, int at_head)
+{
+       DECLARE_COMPLETION_ONSTACK(wait);
+
+       WARN_ON_ONCE(!test_bit(QUEUE_FLAG_POLL, &q->queue_flags));
+
+       rq->cmd_flags |= REQ_HIPRI;
+       rq->end_io_data = &wait;
+       blk_execute_rq_nowait(q, bd_disk, rq, at_head, blk_end_sync_rq);
+
+       while (!completion_done(&wait)) {
+               blk_poll(q, request_to_qc_t(rq->mq_hctx, rq), true);
+               cond_resched();
+       }
+}
+EXPORT_SYMBOL(blk_execute_rq_polled);
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 65770da99159..65d3f3a69c0d 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -1747,14 +1747,6 @@ static void blk_mq_bio_to_request(struct request *rq, 
struct bio *bio)
        blk_account_io_start(rq, true);
 }
 
-static blk_qc_t request_to_qc_t(struct blk_mq_hw_ctx *hctx, struct request *rq)
-{
-       if (rq->tag != -1)
-               return blk_tag_to_qc_t(rq->tag, hctx->queue_num, false);
-
-       return blk_tag_to_qc_t(rq->internal_tag, hctx->queue_num, true);
-}
-
 static blk_status_t __blk_mq_issue_directly(struct blk_mq_hw_ctx *hctx,
                                            struct request *rq,
                                            blk_qc_t *cookie, bool last)
diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index 57eda7b20243..c77cba1ec0f5 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -357,4 +357,12 @@ static inline void *blk_mq_rq_to_pdu(struct request *rq)
        for ((i) = 0; (i) < (hctx)->nr_ctx &&                           \
             ({ ctx = (hctx)->ctxs[(i)]; 1; }); (i)++)
 
+static inline blk_qc_t request_to_qc_t(struct blk_mq_hw_ctx *hctx, struct 
request *rq)
+{
+       if (rq->tag != -1)
+               return blk_tag_to_qc_t(rq->tag, hctx->queue_num, false);
+
+       return blk_tag_to_qc_t(rq->internal_tag, hctx->queue_num, true);
+}
+
 #endif
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 81f1b105946b..9f48d8855916 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -860,6 +860,8 @@ extern void blk_execute_rq(struct request_queue *, struct 
gendisk *,
                          struct request *, int);
 extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *,
                                  struct request *, int, rq_end_io_fn *);
+void blk_execute_rq_polled(struct request_queue *q, struct gendisk *bd_disk,
+                  struct request *rq, int at_head);
 
 int blk_status_to_errno(blk_status_t status);
 blk_status_t errno_to_blk_status(int errno);
-- 
2.17.1

Reply via email to