[linux-block.git] / block / blk.h

#ifndef BLK_INTERNAL_H
#define BLK_INTERNAL_H

/* Amount of time in which a process may batch requests */
#define BLK_BATCH_TIME	(HZ/50UL)

/* Number of requests a "batching" process may submit */
#define BLK_BATCH_REQ	32

extern struct kmem_cache *blk_requestq_cachep;
extern struct kobj_type blk_queue_ktype;

void init_request_from_bio(struct request *req, struct bio *bio);
void blk_rq_bio_prep(struct request_queue *q, struct request *rq,
			struct bio *bio);
void __blk_queue_free_tags(struct request_queue *q);

void blk_unplug_work(struct work_struct *work);
void blk_unplug_timeout(unsigned long data);

struct io_context *current_io_context(gfp_t gfp_flags, int node);

int ll_back_merge_fn(struct request_queue *q, struct request *req,
		     struct bio *bio);
int ll_front_merge_fn(struct request_queue *q, struct request *req, 
		      struct bio *bio);
int attempt_back_merge(struct request_queue *q, struct request *rq);
int attempt_front_merge(struct request_queue *q, struct request *rq);
void blk_recalc_rq_segments(struct request *rq);
void blk_recalc_rq_sectors(struct request *rq, int nsect);

void blk_queue_congestion_threshold(struct request_queue *q);

int blk_dev_init(void);

/*
 * Return the threshold (number of used requests) at which the queue is
 * considered to be congested.  It include a little hysteresis to keep the
 * context switch rate down.
 */
static inline int queue_congestion_on_threshold(struct request_queue *q)
{
	return q->nr_congestion_on;
}

/*
 * The threshold at which a queue is considered to be uncongested
 */
static inline int queue_congestion_off_threshold(struct request_queue *q)
{
	return q->nr_congestion_off;
}

#if defined(CONFIG_BLK_DEV_INTEGRITY)

#define rq_for_each_integrity_segment(bvl, _rq, _iter)		\
	__rq_for_each_bio(_iter.bio, _rq)			\
		bip_for_each_vec(bvl, _iter.bio->bi_integrity, _iter.i)

#endif /* BLK_DEV_INTEGRITY */

#endif
Commit	Line	Data
8324aa91 JA	1	#ifndef BLK_INTERNAL_H
	2	#define BLK_INTERNAL_H
	3
86db1e29 JA	4	/* Amount of time in which a process may batch requests */
	5	#define BLK_BATCH_TIME (HZ/50UL)
	6
	7	/* Number of requests a "batching" process may submit */
	8	#define BLK_BATCH_REQ 32
	9
8324aa91 JA	10	extern struct kmem_cache *blk_requestq_cachep;
	11	extern struct kobj_type blk_queue_ktype;
	12
86db1e29 JA	13	void init_request_from_bio(struct request req, struct bio bio);
	14	void blk_rq_bio_prep(struct request_queue q, struct request rq,
	15	struct bio *bio);
8324aa91 JA	16	void __blk_queue_free_tags(struct request_queue *q);
8324aa91 JA	17
86db1e29 JA	18	void blk_unplug_work(struct work_struct *work);
	19	void blk_unplug_timeout(unsigned long data);
	20
	21	struct io_context *current_io_context(gfp_t gfp_flags, int node);
	22
d6d48196 JA	23	int ll_back_merge_fn(struct request_queue q, struct request req,
	24	struct bio *bio);
	25	int ll_front_merge_fn(struct request_queue q, struct request req,
	26	struct bio *bio);
	27	int attempt_back_merge(struct request_queue q, struct request rq);
	28	int attempt_front_merge(struct request_queue q, struct request rq);
	29	void blk_recalc_rq_segments(struct request *rq);
	30	void blk_recalc_rq_sectors(struct request *rq, int nsect);
	31
8324aa91 JA	32	void blk_queue_congestion_threshold(struct request_queue *q);
8324aa91 JA	33
ff88972c AB	34	int blk_dev_init(void);
ff88972c AB	35
8324aa91 JA	36	/*
	37	* Return the threshold (number of used requests) at which the queue is
	38	* considered to be congested. It include a little hysteresis to keep the
	39	* context switch rate down.
	40	*/
	41	static inline int queue_congestion_on_threshold(struct request_queue *q)
	42	{
	43	return q->nr_congestion_on;
	44	}
	45
	46	/*
	47	* The threshold at which a queue is considered to be uncongested
	48	*/
	49	static inline int queue_congestion_off_threshold(struct request_queue *q)
	50	{
	51	return q->nr_congestion_off;
	52	}
	53
7ba1ba12 MP	54	#if defined(CONFIG_BLK_DEV_INTEGRITY)
	55
	56	#define rq_for_each_integrity_segment(bvl, _rq, _iter) \
	57	__rq_for_each_bio(_iter.bio, _rq) \
	58	bip_for_each_vec(bvl, _iter.bio->bi_integrity, _iter.i)
	59
	60	#endif /* BLK_DEV_INTEGRITY */
	61
8324aa91	62	#endif