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>
This commit is contained in:
Christoph Hellwig 2022-10-20 08:48:16 +02:00 committed by Jens Axboe
parent 671fae5e51
commit dd6f7f17bf
3 changed files with 19 additions and 16 deletions

View File

@ -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);

View File

@ -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);
@ -659,7 +654,7 @@ 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);

View File

@ -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);