[linux-2.6-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);
void blk_rq_timed_out_timer(unsigned long data);
void blk_delete_timer(struct request *);
void blk_add_timer(struct request *);

/*
 * Internal atomic flags for request handling
 */
enum rq_atomic_flags {
	REQ_ATOM_COMPLETE = 0,
};

/*
 * EH timer and IO completion will both attempt to 'grab' the request, make
 * sure that only one of them suceeds
 */
static inline int blk_mark_rq_complete(struct request *rq)
{
	return test_and_set_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags);
}

static inline void blk_clear_rq_complete(struct request *rq)
{
	clear_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags);
}

#ifdef CONFIG_FAIL_IO_TIMEOUT
int blk_should_fake_timeout(struct request_queue *);
ssize_t part_timeout_show(struct device *, struct device_attribute *, char *);
ssize_t part_timeout_store(struct device *, struct device_attribute *,
				const char *, size_t);
#else
static inline int blk_should_fake_timeout(struct request_queue *q)
{
	return 0;
}
#endif

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 */

static inline int blk_cpu_to_group(int cpu)
{
#ifdef CONFIG_SCHED_MC
	cpumask_t mask = cpu_coregroup_map(cpu);
	return first_cpu(mask);
#elif defined(CONFIG_SCHED_SMT)
	return first_cpu(per_cpu(cpu_sibling_map, cpu));
#else
	return cpu;
#endif
}

#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);
86db1e29 JA	19	void blk_unplug_timeout(unsigned long data);
242f9dcb JA	20	void blk_rq_timed_out_timer(unsigned long data);
	21	void blk_delete_timer(struct request *);
	22	void blk_add_timer(struct request *);
	23
	24	/*
	25	* Internal atomic flags for request handling
	26	*/
	27	enum rq_atomic_flags {
	28	REQ_ATOM_COMPLETE = 0,
	29	};
	30
	31	/*
	32	* EH timer and IO completion will both attempt to 'grab' the request, make
	33	* sure that only one of them suceeds
	34	*/
	35	static inline int blk_mark_rq_complete(struct request *rq)
	36	{
	37	return test_and_set_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags);
	38	}
	39
	40	static inline void blk_clear_rq_complete(struct request *rq)
	41	{
	42	clear_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags);
	43	}
86db1e29	44
581d4e28 JA	45	#ifdef CONFIG_FAIL_IO_TIMEOUT
	46	int blk_should_fake_timeout(struct request_queue *);
	47	ssize_t part_timeout_show(struct device , struct device_attribute , char *);
	48	ssize_t part_timeout_store(struct device , struct device_attribute ,
	49	const char *, size_t);
	50	#else
	51	static inline int blk_should_fake_timeout(struct request_queue *q)
	52	{
	53	return 0;
	54	}
	55	#endif
	56
86db1e29 JA	57	struct io_context *current_io_context(gfp_t gfp_flags, int node);
86db1e29 JA	58
d6d48196 JA	59	int ll_back_merge_fn(struct request_queue q, struct request req,
	60	struct bio *bio);
	61	int ll_front_merge_fn(struct request_queue q, struct request req,
	62	struct bio *bio);
	63	int attempt_back_merge(struct request_queue q, struct request rq);
	64	int attempt_front_merge(struct request_queue q, struct request rq);
	65	void blk_recalc_rq_segments(struct request *rq);
	66	void blk_recalc_rq_sectors(struct request *rq, int nsect);
	67
8324aa91 JA	68	void blk_queue_congestion_threshold(struct request_queue *q);
8324aa91 JA	69
ff88972c AB	70	int blk_dev_init(void);
ff88972c AB	71
8324aa91 JA	72	/*
	73	* Return the threshold (number of used requests) at which the queue is
	74	* considered to be congested. It include a little hysteresis to keep the
	75	* context switch rate down.
	76	*/
	77	static inline int queue_congestion_on_threshold(struct request_queue *q)
	78	{
	79	return q->nr_congestion_on;
	80	}
	81
	82	/*
	83	* The threshold at which a queue is considered to be uncongested
	84	*/
	85	static inline int queue_congestion_off_threshold(struct request_queue *q)
	86	{
	87	return q->nr_congestion_off;
	88	}
	89
7ba1ba12 MP	90	#if defined(CONFIG_BLK_DEV_INTEGRITY)
	91
	92	#define rq_for_each_integrity_segment(bvl, _rq, _iter) \
	93	__rq_for_each_bio(_iter.bio, _rq) \
	94	bip_for_each_vec(bvl, _iter.bio->bi_integrity, _iter.i)
	95
	96	#endif /* BLK_DEV_INTEGRITY */
	97
c7c22e4d JA	98	static inline int blk_cpu_to_group(int cpu)
	99	{
	100	#ifdef CONFIG_SCHED_MC
	101	cpumask_t mask = cpu_coregroup_map(cpu);
	102	return first_cpu(mask);
	103	#elif defined(CONFIG_SCHED_SMT)
	104	return first_cpu(per_cpu(cpu_sibling_map, cpu));
	105	#else
	106	return cpu;
	107	#endif
	108	}
	109
8324aa91	110	#endif