block: allow initialization of previously allocated request_queue

blk_init_queue() allocates the request_queue structure and then
initializes it as needed (request_fn, elevator, etc).

Split initialization out to blk_init_allocated_queue_node.
Introduce blk_init_allocated_queue wrapper function to model existing
blk_init_queue and blk_init_queue_node interfaces.

Export elv_register_queue to allow a newly added elevator to be
registered with sysfs.  Export elv_unregister_queue for symmetry.

These changes allow DM to initialize a device's request_queue with more
precision.  In particular, DM no longer unconditionally initializes a
full request_queue (elevator et al).  It only does so for a
request-based DM device.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This commit is contained in:
Mike Snitzer 2010-05-11 08:57:42 +02:00 committed by Jens Axboe
parent 0f3942a39e
commit 01effb0dc1
3 changed files with 24 additions and 1 deletions

View File

@ -572,6 +572,22 @@ blk_init_queue_node(request_fn_proc *rfn, spinlock_t *lock, int node_id)
{
struct request_queue *q = blk_alloc_queue_node(GFP_KERNEL, node_id);
return blk_init_allocated_queue_node(q, rfn, lock, node_id);
}
EXPORT_SYMBOL(blk_init_queue_node);
struct request_queue *
blk_init_allocated_queue(struct request_queue *q, request_fn_proc *rfn,
spinlock_t *lock)
{
return blk_init_allocated_queue_node(q, rfn, lock, -1);
}
EXPORT_SYMBOL(blk_init_allocated_queue);
struct request_queue *
blk_init_allocated_queue_node(struct request_queue *q, request_fn_proc *rfn,
spinlock_t *lock, int node_id)
{
if (!q)
return NULL;
@ -605,7 +621,7 @@ blk_init_queue_node(request_fn_proc *rfn, spinlock_t *lock, int node_id)
blk_put_queue(q);
return NULL;
}
EXPORT_SYMBOL(blk_init_queue_node);
EXPORT_SYMBOL(blk_init_allocated_queue_node);
int blk_get_queue(struct request_queue *q)
{

View File

@ -930,6 +930,7 @@ int elv_register_queue(struct request_queue *q)
}
return error;
}
EXPORT_SYMBOL(elv_register_queue);
static void __elv_unregister_queue(struct elevator_queue *e)
{
@ -942,6 +943,7 @@ void elv_unregister_queue(struct request_queue *q)
if (q)
__elv_unregister_queue(q->elevator);
}
EXPORT_SYMBOL(elv_unregister_queue);
void elv_register(struct elevator_type *e)
{

View File

@ -921,7 +921,12 @@ extern void blk_abort_queue(struct request_queue *);
*/
extern struct request_queue *blk_init_queue_node(request_fn_proc *rfn,
spinlock_t *lock, int node_id);
extern struct request_queue *blk_init_allocated_queue_node(struct request_queue *,
request_fn_proc *,
spinlock_t *, int node_id);
extern struct request_queue *blk_init_queue(request_fn_proc *, spinlock_t *);
extern struct request_queue *blk_init_allocated_queue(struct request_queue *,
request_fn_proc *, spinlock_t *);
extern void blk_cleanup_queue(struct request_queue *);
extern void blk_queue_make_request(struct request_queue *, make_request_fn *);
extern void blk_queue_bounce_limit(struct request_queue *, u64);