block: add proper helpers for elevator_type module refcount management

Make sure we have helpers for all relevant module refcount operations on
the elevator_type in elevator.h, and use them.  Move the call to the get
helper in blk_mq_elv_switch_none a bit so that it is obvious with a less
verbose comment.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20221020064819.1469928-2-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

1 files changed, 15 insertions, 0 deletions

diff --git a/block/elevator.h b/block/elevator.h
index 75382471222d..774a8f6b99e6 100644
--- a/block/elevator.h
+++ b/block/elevator.h
@@ -84,6 +84,21 @@ struct elevator_type
 	struct list_head list;
 };
 
+static inline bool elevator_tryget(struct elevator_type *e)
+{
+	return try_module_get(e->elevator_owner);
+}
+
+static inline void __elevator_get(struct elevator_type *e)
+{
+	__module_get(e->elevator_owner);
+}
+
+static inline void elevator_put(struct elevator_type *e)
+{
+	module_put(e->elevator_owner);
+}
+
 #define ELV_HASH_BITS 6
 
 void elv_rqhash_del(struct request_queue *q, struct request *rq);