blk-mq: change blk_mq_queue_busy() to blk_mq_queue_inflight()

There's a single user of this function, dm, and dm just wants
to check if IO is inflight, not that it's just allocated.

This fixes a hang with srp/002 in blktests with dm, where it tries
to suspend but waits for inflight IO to finish first. As it checks
for just allocated requests, this fails.

Tested-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/block/blk-mq.c b/block/blk-mq.c
index 6847f01..b0888a8 100644 (file)
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -805,14 +805,14 @@ struct request *blk_mq_tag_to_rq(struct blk_mq_tags *tags, unsigned int tag)
 }
 EXPORT_SYMBOL(blk_mq_tag_to_rq);
 
-static bool blk_mq_check_busy(struct blk_mq_hw_ctx *hctx, struct request *rq,
-                             void *priv, bool reserved)
+static bool blk_mq_rq_inflight(struct blk_mq_hw_ctx *hctx, struct request *rq,
+                              void *priv, bool reserved)
 {
        /*
-        * If we find a request, we know the queue is busy. Return false
-        * to stop the iteration.
+        * If we find a request that is inflight and the queue matches,
+        * we know the queue is busy. Return false to stop the iteration.
         */
-       if (rq->q == hctx->queue) {
+       if (rq->state == MQ_RQ_IN_FLIGHT && rq->q == hctx->queue) {
                bool *busy = priv;
 
                *busy = true;
@@ -822,14 +822,14 @@ static bool blk_mq_check_busy(struct blk_mq_hw_ctx *hctx, struct request *rq,
        return true;
 }
 
-bool blk_mq_queue_busy(struct request_queue *q)
+bool blk_mq_queue_inflight(struct request_queue *q)
 {
        bool busy = false;
 
-       blk_mq_queue_tag_busy_iter(q, blk_mq_check_busy, &busy);
+       blk_mq_queue_tag_busy_iter(q, blk_mq_rq_inflight, &busy);
        return busy;
 }
-EXPORT_SYMBOL_GPL(blk_mq_queue_busy);
+EXPORT_SYMBOL_GPL(blk_mq_queue_inflight);
 
 static void blk_mq_rq_timed_out(struct request *req, bool reserved)
 {

diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index c414d40..dddbca6 100644 (file)
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -663,7 +663,7 @@ static bool md_in_flight_bios(struct mapped_device *md)
 static bool md_in_flight(struct mapped_device *md)
 {
        if (queue_is_mq(md->queue))
-               return blk_mq_queue_busy(md->queue);
+               return blk_mq_queue_inflight(md->queue);
        else
                return md_in_flight_bios(md);
 }

diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index 57eda7b..d3c0a0d 100644 (file)
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -257,7 +257,7 @@ void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule);
 void blk_mq_free_request(struct request *rq);
 bool blk_mq_can_queue(struct blk_mq_hw_ctx *);
 
-bool blk_mq_queue_busy(struct request_queue *q);
+bool blk_mq_queue_inflight(struct request_queue *q);
 
 enum {
        /* return when out of requests */