[PATCH 1/4] block: add proper helpers for elevator_type module refcount management
From: Christoph Hellwig <hch@lst.de>
Date: 2022-10-20 06:48:35
Subsystem:
block layer, the rest · Maintainers:
Jens Axboe, Linus Torvalds
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> --- block/blk-mq.c | 11 ++--------- block/elevator.c | 9 ++------- block/elevator.h | 15 +++++++++++++++ 3 files changed, 19 insertions(+), 16 deletions(-)
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 33292c01875d5..9db8814cdd02b 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c@@ -4554,17 +4554,10 @@ static bool blk_mq_elv_switch_none(struct list_head *head, INIT_LIST_HEAD(&qe->node); qe->q = q; + /* keep a reference to the elevator module as we'll switch back */ + __elevator_get(qe->type); qe->type = q->elevator->type; list_add(&qe->node, head); - - /* - * After elevator_switch, the previous elevator_queue will be - * released by elevator_release. The reference of the io scheduler - * module get by elevator_get will also be put. So we need to get - * a reference of the io scheduler module here to prevent it to be - * removed. - */ - __module_get(qe->type->elevator_owner); elevator_switch(q, NULL); mutex_unlock(&q->sysfs_lock);
diff --git a/block/elevator.c b/block/elevator.c
index bd71f0fc4e4b6..40ba43aa9ece0 100644
--- a/block/elevator.c
+++ b/block/elevator.c@@ -132,11 +132,6 @@ static struct elevator_type *elevator_find(const char *name, return NULL; } -static void elevator_put(struct elevator_type *e) -{ - module_put(e->elevator_owner); -} - static struct elevator_type *elevator_get(struct request_queue *q, const char *name, bool try_loading) {
@@ -152,7 +147,7 @@ static struct elevator_type *elevator_get(struct request_queue *q, e = elevator_find(name, q->required_elevator_features); } - if (e && !try_module_get(e->elevator_owner)) + if (e && !elevator_tryget(e)) e = NULL; spin_unlock(&elv_list_lock);
@@ -663,7 +658,7 @@ static struct elevator_type *elevator_get_by_features(struct request_queue *q) } } - if (found && !try_module_get(found->elevator_owner)) + if (found && !elevator_tryget(found)) found = NULL; spin_unlock(&elv_list_lock);
diff --git a/block/elevator.h b/block/elevator.h
index 3f0593b3bf9d3..44e5f35fa740d 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);
--
2.30.2