block: add queue_to_disk() to get gendisk from request_queue

Sometimes we need to get the corresponding gendisk from request_queue.

It is preferred that block drivers store private data in
gendisk->private_data rather than request_queue->queuedata, e.g. see:
commit c4a59c4e5db3 ("dm: stop using ->queuedata").

So if only request_queue is given, we need to get its corresponding
gendisk to get the private data stored in that gendisk.

Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jeffle Xu <jefflexu@linux.alibaba.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index d5d320da51f8bfab95cbc02d578481a94bc4cc8c..30d2090583add288a054eb00deccb04c8ebe767f 100644 (file)
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -689,6 +689,8 @@ static inline bool blk_account_rq(struct request *rq)
        dma_map_page_attrs(dev, (bv)->bv_page, (bv)->bv_offset, (bv)->bv_len, \
        (dir), (attrs))
 
+#define queue_to_disk(q)       (dev_to_disk(kobj_to_dev((q)->kobj.parent)))
+
 static inline bool queue_is_mq(struct request_queue *q)
 {
        return q->mq_ops;

diff --git a/include/trace/events/kyber.h b/include/trace/events/kyber.h
index c0e7d24ca25682acf384d56d7b0c87e71e6c456b..f9802562edf6cbc9437304e2a5acf0fe02a19332 100644 (file)
--- a/include/trace/events/kyber.h
+++ b/include/trace/events/kyber.h
@@ -30,7 +30,7 @@ TRACE_EVENT(kyber_latency,
        ),
 
        TP_fast_assign(
-               __entry->dev            = disk_devt(dev_to_disk(kobj_to_dev(q->kobj.parent)));
+               __entry->dev            = disk_devt(queue_to_disk(q));
                strlcpy(__entry->domain, domain, sizeof(__entry->domain));
                strlcpy(__entry->type, type, sizeof(__entry->type));
                __entry->percentile     = percentile;
@@ -59,7 +59,7 @@ TRACE_EVENT(kyber_adjust,
        ),
 
        TP_fast_assign(
-               __entry->dev            = disk_devt(dev_to_disk(kobj_to_dev(q->kobj.parent)));
+               __entry->dev            = disk_devt(queue_to_disk(q));
                strlcpy(__entry->domain, domain, sizeof(__entry->domain));
                __entry->depth          = depth;
        ),
@@ -81,7 +81,7 @@ TRACE_EVENT(kyber_throttled,
        ),
 
        TP_fast_assign(
-               __entry->dev            = disk_devt(dev_to_disk(kobj_to_dev(q->kobj.parent)));
+               __entry->dev            = disk_devt(queue_to_disk(q));
                strlcpy(__entry->domain, domain, sizeof(__entry->domain));
        ),