Commit 01effb0d authored by Mike Snitzer's avatar Mike Snitzer Committed by Jens Axboe
Browse files

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: default avatarMike Snitzer <snitzer@redhat.com>
Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
parent 0f3942a3

block/blk-core.c

+17 −1
Original line number Diff line number Diff line
@@ -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)

{

block/elevator.c

+2 −0
Original line number Diff line number Diff line
@@ -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)

{

include/linux/blkdev.h

+5 −0
Original line number Diff line number Diff line
@@ -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);

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