[linux-2.6-block.git] / block / blk.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef BLK_INTERNAL_H
#define BLK_INTERNAL_H

#include <linux/idr.h>
#include <linux/blk-mq.h>
#include "blk-mq.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

/* Max future timer expiry for timeouts */
#define BLK_MAX_TIMEOUT		(5 * HZ)

#ifdef CONFIG_DEBUG_FS
extern struct dentry *blk_debugfs_root;
#endif

struct blk_flush_queue {
	unsigned int		flush_queue_delayed:1;
	unsigned int		flush_pending_idx:1;
	unsigned int		flush_running_idx:1;
	unsigned long		flush_pending_since;
	struct list_head	flush_queue[2];
	struct list_head	flush_data_in_flight;
	struct request		*flush_rq;

	/*
	 * flush_rq shares tag with this rq, both can't be active
	 * at the same time
	 */
	struct request		*orig_rq;
	spinlock_t		mq_flush_lock;
};

extern struct kmem_cache *blk_requestq_cachep;
extern struct kmem_cache *request_cachep;
extern struct kobj_type blk_queue_ktype;
extern struct ida blk_queue_ida;

/*
 * @q->queue_lock is set while a queue is being initialized. Since we know
 * that no other threads access the queue object before @q->queue_lock has
 * been set, it is safe to manipulate queue flags without holding the
 * queue_lock if @q->queue_lock == NULL. See also blk_alloc_queue_node() and
 * blk_init_allocated_queue().
 */
static inline void queue_lockdep_assert_held(struct request_queue *q)
{
	if (q->queue_lock)
		lockdep_assert_held(q->queue_lock);
}

static inline void queue_flag_set_unlocked(unsigned int flag,
					   struct request_queue *q)
{
	if (test_bit(QUEUE_FLAG_INIT_DONE, &q->queue_flags) &&
	    kref_read(&q->kobj.kref))
		lockdep_assert_held(q->queue_lock);
	__set_bit(flag, &q->queue_flags);
}

static inline void queue_flag_clear_unlocked(unsigned int flag,
					     struct request_queue *q)
{
	if (test_bit(QUEUE_FLAG_INIT_DONE, &q->queue_flags) &&
	    kref_read(&q->kobj.kref))
		lockdep_assert_held(q->queue_lock);
	__clear_bit(flag, &q->queue_flags);
}

static inline int queue_flag_test_and_clear(unsigned int flag,
					    struct request_queue *q)
{
	queue_lockdep_assert_held(q);

	if (test_bit(flag, &q->queue_flags)) {
		__clear_bit(flag, &q->queue_flags);
		return 1;
	}

	return 0;
}

static inline int queue_flag_test_and_set(unsigned int flag,
					  struct request_queue *q)
{
	queue_lockdep_assert_held(q);

	if (!test_bit(flag, &q->queue_flags)) {
		__set_bit(flag, &q->queue_flags);
		return 0;
	}

	return 1;
}

static inline void queue_flag_set(unsigned int flag, struct request_queue *q)
{
	queue_lockdep_assert_held(q);
	__set_bit(flag, &q->queue_flags);
}

static inline void queue_flag_clear(unsigned int flag, struct request_queue *q)
{
	queue_lockdep_assert_held(q);
	__clear_bit(flag, &q->queue_flags);
}

static inline struct blk_flush_queue *blk_get_flush_queue(
		struct request_queue *q, struct blk_mq_ctx *ctx)
{
	if (q->mq_ops)
		return blk_mq_map_queue(q, ctx->cpu)->fq;
	return q->fq;
}

static inline void __blk_get_queue(struct request_queue *q)
{
	kobject_get(&q->kobj);
}

struct blk_flush_queue *blk_alloc_flush_queue(struct request_queue *q,
		int node, int cmd_size);
void blk_free_flush_queue(struct blk_flush_queue *q);

int blk_init_rl(struct request_list *rl, struct request_queue *q,
		gfp_t gfp_mask);
void blk_exit_rl(struct request_queue *q, struct request_list *rl);
void blk_rq_bio_prep(struct request_queue *q, struct request *rq,
			struct bio *bio);
void blk_queue_bypass_start(struct request_queue *q);
void blk_queue_bypass_end(struct request_queue *q);
void __blk_queue_free_tags(struct request_queue *q);
void blk_freeze_queue(struct request_queue *q);

static inline void blk_queue_enter_live(struct request_queue *q)
{
	/*
	 * Given that running in generic_make_request() context
	 * guarantees that a live reference against q_usage_counter has
	 * been established, further references under that same context
	 * need not check that the queue has been frozen (marked dead).
	 */
	percpu_ref_get(&q->q_usage_counter);
}

#ifdef CONFIG_BLK_DEV_INTEGRITY
void blk_flush_integrity(void);
bool __bio_integrity_endio(struct bio *);
static inline bool bio_integrity_endio(struct bio *bio)
{
	if (bio_integrity(bio))
		return __bio_integrity_endio(bio);
	return true;
}
#else
static inline void blk_flush_integrity(void)
{
}
static inline bool bio_integrity_endio(struct bio *bio)
{
	return true;
}
#endif

void blk_timeout_work(struct work_struct *work);
unsigned long blk_rq_timeout(unsigned long timeout);
void blk_add_timer(struct request *req);
void blk_delete_timer(struct request *);


bool bio_attempt_front_merge(struct request_queue *q, struct request *req,
			     struct bio *bio);
bool bio_attempt_back_merge(struct request_queue *q, struct request *req,
			    struct bio *bio);
bool bio_attempt_discard_merge(struct request_queue *q, struct request *req,
		struct bio *bio);
bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio,
			    unsigned int *request_count,
			    struct request **same_queue_rq);
unsigned int blk_plug_queued_count(struct request_queue *q);

void blk_account_io_start(struct request *req, bool new_io);
void blk_account_io_completion(struct request *req, unsigned int bytes);
void blk_account_io_done(struct request *req);

/*
 * EH timer and IO completion will both attempt to 'grab' the request, make
 * sure that only one of them succeeds. Steal the bottom bit of the
 * __deadline field for this.
 */
static inline int blk_mark_rq_complete(struct request *rq)
{
	return test_and_set_bit(0, &rq->__deadline);
}

static inline void blk_clear_rq_complete(struct request *rq)
{
	clear_bit(0, &rq->__deadline);
}

static inline bool blk_rq_is_complete(struct request *rq)
{
	return test_bit(0, &rq->__deadline);
}

/*
 * Internal elevator interface
 */
#define ELV_ON_HASH(rq) ((rq)->rq_flags & RQF_HASHED)

void blk_insert_flush(struct request *rq);

static inline void elv_activate_rq(struct request_queue *q, struct request *rq)
{
	struct elevator_queue *e = q->elevator;

	if (e->type->ops.sq.elevator_activate_req_fn)
		e->type->ops.sq.elevator_activate_req_fn(q, rq);
}

static inline void elv_deactivate_rq(struct request_queue *q, struct request *rq)
{
	struct elevator_queue *e = q->elevator;

	if (e->type->ops.sq.elevator_deactivate_req_fn)
		e->type->ops.sq.elevator_deactivate_req_fn(q, rq);
}

int elv_register_queue(struct request_queue *q);
void elv_unregister_queue(struct request_queue *q);

struct hd_struct *__disk_get_part(struct gendisk *disk, int partno);

#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

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);
struct request *attempt_back_merge(struct request_queue *q, struct request *rq);
struct request *attempt_front_merge(struct request_queue *q, struct request *rq);
int blk_attempt_req_merge(struct request_queue *q, struct request *rq,
				struct request *next);
void blk_recalc_rq_segments(struct request *rq);
void blk_rq_set_mixed_merge(struct request *rq);
bool blk_rq_merge_ok(struct request *rq, struct bio *bio);
enum elv_merge blk_try_merge(struct request *rq, struct bio *bio);

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;
}

extern int blk_update_nr_requests(struct request_queue *, unsigned int);

/*
 * Contribute to IO statistics IFF:
 *
 *	a) it's attached to a gendisk, and
 *	b) the queue had IO stats enabled when this request was started, and
 *	c) it's a file system request
 */
static inline int blk_do_io_stat(struct request *rq)
{
	return rq->rq_disk &&
	       (rq->rq_flags & RQF_IO_STAT) &&
		!blk_rq_is_passthrough(rq);
}

static inline void req_set_nomerge(struct request_queue *q, struct request *req)
{
	req->cmd_flags |= REQ_NOMERGE;
	if (req == q->last_merge)
		q->last_merge = NULL;
}

/*
 * Steal a bit from this field for legacy IO path atomic IO marking. Note that
 * setting the deadline clears the bottom bit, potentially clearing the
 * completed bit. The user has to be OK with this (current ones are fine).
 */
static inline void blk_rq_set_deadline(struct request *rq, unsigned long time)
{
	rq->__deadline = time & ~0x1UL;
}

static inline unsigned long blk_rq_deadline(struct request *rq)
{
	return rq->__deadline & ~0x1UL;
}

/*
 * Internal io_context interface
 */
void get_io_context(struct io_context *ioc);
struct io_cq *ioc_lookup_icq(struct io_context *ioc, struct request_queue *q);
struct io_cq *ioc_create_icq(struct io_context *ioc, struct request_queue *q,
			     gfp_t gfp_mask);
void ioc_clear_queue(struct request_queue *q);

int create_task_io_context(struct task_struct *task, gfp_t gfp_mask, int node);

/**
 * rq_ioc - determine io_context for request allocation
 * @bio: request being allocated is for this bio (can be %NULL)
 *
 * Determine io_context to use for request allocation for @bio.  May return
 * %NULL if %current->io_context doesn't exist.
 */
static inline struct io_context *rq_ioc(struct bio *bio)
{
#ifdef CONFIG_BLK_CGROUP
	if (bio && bio->bi_ioc)
		return bio->bi_ioc;
#endif
	return current->io_context;
}

/**
 * create_io_context - try to create task->io_context
 * @gfp_mask: allocation mask
 * @node: allocation node
 *
 * If %current->io_context is %NULL, allocate a new io_context and install
 * it.  Returns the current %current->io_context which may be %NULL if
 * allocation failed.
 *
 * Note that this function can't be called with IRQ disabled because
 * task_lock which protects %current->io_context is IRQ-unsafe.
 */
static inline struct io_context *create_io_context(gfp_t gfp_mask, int node)
{
	WARN_ON_ONCE(irqs_disabled());
	if (unlikely(!current->io_context))
		create_task_io_context(current, gfp_mask, node);
	return current->io_context;
}

/*
 * Internal throttling interface
 */
#ifdef CONFIG_BLK_DEV_THROTTLING
extern void blk_throtl_drain(struct request_queue *q);
extern int blk_throtl_init(struct request_queue *q);
extern void blk_throtl_exit(struct request_queue *q);
extern void blk_throtl_register_queue(struct request_queue *q);
#else /* CONFIG_BLK_DEV_THROTTLING */
static inline void blk_throtl_drain(struct request_queue *q) { }
static inline int blk_throtl_init(struct request_queue *q) { return 0; }
static inline void blk_throtl_exit(struct request_queue *q) { }
static inline void blk_throtl_register_queue(struct request_queue *q) { }
#endif /* CONFIG_BLK_DEV_THROTTLING */
#ifdef CONFIG_BLK_DEV_THROTTLING_LOW
extern ssize_t blk_throtl_sample_time_show(struct request_queue *q, char *page);
extern ssize_t blk_throtl_sample_time_store(struct request_queue *q,
	const char *page, size_t count);
extern void blk_throtl_bio_endio(struct bio *bio);
extern void blk_throtl_stat_add(struct request *rq, u64 time);
#else
static inline void blk_throtl_bio_endio(struct bio *bio) { }
static inline void blk_throtl_stat_add(struct request *rq, u64 time) { }
#endif

#ifdef CONFIG_BOUNCE
extern int init_emergency_isa_pool(void);
extern void blk_queue_bounce(struct request_queue *q, struct bio **bio);
#else
static inline int init_emergency_isa_pool(void)
{
	return 0;
}
static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio)
{
}
#endif /* CONFIG_BOUNCE */

extern void blk_drain_queue(struct request_queue *q);

#endif /* BLK_INTERNAL_H */
Commit	Line	Data
b2441318	1	/* SPDX-License-Identifier: GPL-2.0 */
8324aa91 JA	2	#ifndef BLK_INTERNAL_H
	3	#define BLK_INTERNAL_H
	4
a73f730d	5	#include <linux/idr.h>
f70ced09 ML	6	#include <linux/blk-mq.h>
f70ced09 ML	7	#include "blk-mq.h"
a73f730d	8
86db1e29 JA	9	/* Amount of time in which a process may batch requests */
	10	#define BLK_BATCH_TIME (HZ/50UL)
	11
	12	/* Number of requests a "batching" process may submit */
	13	#define BLK_BATCH_REQ 32
	14
0d2602ca JA	15	/* Max future timer expiry for timeouts */
	16	#define BLK_MAX_TIMEOUT (5 * HZ)
	17
18fbda91 OS	18	#ifdef CONFIG_DEBUG_FS
	19	extern struct dentry *blk_debugfs_root;
	20	#endif
	21
7c94e1c1 ML	22	struct blk_flush_queue {
	23	unsigned int flush_queue_delayed:1;
	24	unsigned int flush_pending_idx:1;
	25	unsigned int flush_running_idx:1;
	26	unsigned long flush_pending_since;
	27	struct list_head flush_queue[2];
	28	struct list_head flush_data_in_flight;
	29	struct request *flush_rq;
0048b483 ML	30
	31	/*
	32	* flush_rq shares tag with this rq, both can't be active
	33	* at the same time
	34	*/
	35	struct request *orig_rq;
7c94e1c1 ML	36	spinlock_t mq_flush_lock;
	37	};
	38
8324aa91	39	extern struct kmem_cache *blk_requestq_cachep;
320ae51f	40	extern struct kmem_cache *request_cachep;
8324aa91	41	extern struct kobj_type blk_queue_ktype;
a73f730d	42	extern struct ida blk_queue_ida;
8324aa91	43
8a0ac14b BVA	44	/*
	45	* @q->queue_lock is set while a queue is being initialized. Since we know
	46	* that no other threads access the queue object before @q->queue_lock has
	47	* been set, it is safe to manipulate queue flags without holding the
	48	* queue_lock if @q->queue_lock == NULL. See also blk_alloc_queue_node() and
	49	* blk_init_allocated_queue().
	50	*/
	51	static inline void queue_lockdep_assert_held(struct request_queue *q)
	52	{
	53	if (q->queue_lock)
	54	lockdep_assert_held(q->queue_lock);
	55	}
	56
	57	static inline void queue_flag_set_unlocked(unsigned int flag,
	58	struct request_queue *q)
	59	{
	60	if (test_bit(QUEUE_FLAG_INIT_DONE, &q->queue_flags) &&
	61	kref_read(&q->kobj.kref))
	62	lockdep_assert_held(q->queue_lock);
	63	__set_bit(flag, &q->queue_flags);
	64	}
	65
	66	static inline void queue_flag_clear_unlocked(unsigned int flag,
	67	struct request_queue *q)
	68	{
	69	if (test_bit(QUEUE_FLAG_INIT_DONE, &q->queue_flags) &&
	70	kref_read(&q->kobj.kref))
	71	lockdep_assert_held(q->queue_lock);
	72	__clear_bit(flag, &q->queue_flags);
	73	}
	74
	75	static inline int queue_flag_test_and_clear(unsigned int flag,
	76	struct request_queue *q)
	77	{
	78	queue_lockdep_assert_held(q);
	79
	80	if (test_bit(flag, &q->queue_flags)) {
	81	__clear_bit(flag, &q->queue_flags);
	82	return 1;
	83	}
	84
	85	return 0;
	86	}
	87
	88	static inline int queue_flag_test_and_set(unsigned int flag,
	89	struct request_queue *q)
	90	{
	91	queue_lockdep_assert_held(q);
	92
	93	if (!test_bit(flag, &q->queue_flags)) {
	94	__set_bit(flag, &q->queue_flags);
	95	return 0;
	96	}
	97
	98	return 1;
	99	}
	100
	101	static inline void queue_flag_set(unsigned int flag, struct request_queue *q)
	102	{
	103	queue_lockdep_assert_held(q);
	104	__set_bit(flag, &q->queue_flags);
	105	}
	106
	107	static inline void queue_flag_clear(unsigned int flag, struct request_queue *q)
108	{
109	queue_lockdep_assert_held(q);
110	__clear_bit(flag, &q->queue_flags);
111	}
112
7c94e1c1	113	static inline struct blk_flush_queue *blk_get_flush_queue(
e97c293c	114	struct request_queue q, struct blk_mq_ctx ctx)
7c94e1c1	115	{
7d7e0f90 CH	116	if (q->mq_ops)
	117	return blk_mq_map_queue(q, ctx->cpu)->fq;
	118	return q->fq;
7c94e1c1 ML	119	}
7c94e1c1 ML	120
09ac46c4 TH	121	static inline void __blk_get_queue(struct request_queue *q)
	122	{
	123	kobject_get(&q->kobj);
	124	}
	125
f70ced09 ML	126	struct blk_flush_queue blk_alloc_flush_queue(struct request_queue q,
	127	int node, int cmd_size);
	128	void blk_free_flush_queue(struct blk_flush_queue *q);
f3552655	129
5b788ce3 TH	130	int blk_init_rl(struct request_list rl, struct request_queue q,
5b788ce3 TH	131	gfp_t gfp_mask);
b425e504	132	void blk_exit_rl(struct request_queue q, struct request_list rl);
86db1e29 JA	133	void blk_rq_bio_prep(struct request_queue q, struct request rq,
86db1e29 JA	134	struct bio *bio);
d732580b TH	135	void blk_queue_bypass_start(struct request_queue *q);
d732580b TH	136	void blk_queue_bypass_end(struct request_queue *q);
8324aa91	137	void __blk_queue_free_tags(struct request_queue *q);
3ef28e83 DW	138	void blk_freeze_queue(struct request_queue *q);
	139
	140	static inline void blk_queue_enter_live(struct request_queue *q)
	141	{
	142	/*
	143	* Given that running in generic_make_request() context
	144	* guarantees that a live reference against q_usage_counter has
	145	* been established, further references under that same context
	146	* need not check that the queue has been frozen (marked dead).
	147	*/
	148	percpu_ref_get(&q->q_usage_counter);
	149	}
8324aa91	150
5a48fc14 DW	151	#ifdef CONFIG_BLK_DEV_INTEGRITY
5a48fc14 DW	152	void blk_flush_integrity(void);
7c20f116 CH	153	bool __bio_integrity_endio(struct bio *);
	154	static inline bool bio_integrity_endio(struct bio *bio)
	155	{
	156	if (bio_integrity(bio))
	157	return __bio_integrity_endio(bio);
	158	return true;
	159	}
5a48fc14 DW	160	#else
	161	static inline void blk_flush_integrity(void)
	162	{
	163	}
7c20f116 CH	164	static inline bool bio_integrity_endio(struct bio *bio)
	165	{
	166	return true;
	167	}
5a48fc14	168	#endif
8324aa91	169
287922eb	170	void blk_timeout_work(struct work_struct *work);
0d2602ca	171	unsigned long blk_rq_timeout(unsigned long timeout);
87ee7b11	172	void blk_add_timer(struct request *req);
242f9dcb	173	void blk_delete_timer(struct request *);
242f9dcb	174
320ae51f JA	175
	176	bool bio_attempt_front_merge(struct request_queue q, struct request req,
	177	struct bio *bio);
	178	bool bio_attempt_back_merge(struct request_queue q, struct request req,
	179	struct bio *bio);
1e739730 CH	180	bool bio_attempt_discard_merge(struct request_queue q, struct request req,
1e739730 CH	181	struct bio *bio);
320ae51f	182	bool blk_attempt_plug_merge(struct request_queue q, struct bio bio,
5b3f341f SL	183	unsigned int *request_count,
5b3f341f SL	184	struct request **same_queue_rq);
0809e3ac	185	unsigned int blk_plug_queued_count(struct request_queue *q);
320ae51f JA	186
	187	void blk_account_io_start(struct request *req, bool new_io);
	188	void blk_account_io_completion(struct request *req, unsigned int bytes);
	189	void blk_account_io_done(struct request *req);
	190
242f9dcb JA	191	/*
242f9dcb JA	192	* EH timer and IO completion will both attempt to 'grab' the request, make
e14575b3 JA	193	* sure that only one of them succeeds. Steal the bottom bit of the
e14575b3 JA	194	* __deadline field for this.
242f9dcb JA	195	*/
	196	static inline int blk_mark_rq_complete(struct request *rq)
	197	{
e14575b3	198	return test_and_set_bit(0, &rq->__deadline);
242f9dcb JA	199	}
	200
	201	static inline void blk_clear_rq_complete(struct request *rq)
	202	{
e14575b3 JA	203	clear_bit(0, &rq->__deadline);
	204	}
	205
	206	static inline bool blk_rq_is_complete(struct request *rq)
	207	{
	208	return test_bit(0, &rq->__deadline);
242f9dcb	209	}
86db1e29	210
158dbda0 TH	211	/*
	212	* Internal elevator interface
	213	*/
e8064021	214	#define ELV_ON_HASH(rq) ((rq)->rq_flags & RQF_HASHED)
158dbda0	215
ae1b1539	216	void blk_insert_flush(struct request *rq);
dd831006	217
158dbda0 TH	218	static inline void elv_activate_rq(struct request_queue q, struct request rq)
	219	{
	220	struct elevator_queue *e = q->elevator;
	221
c51ca6cf JA	222	if (e->type->ops.sq.elevator_activate_req_fn)
c51ca6cf JA	223	e->type->ops.sq.elevator_activate_req_fn(q, rq);
158dbda0 TH	224	}
	225
	226	static inline void elv_deactivate_rq(struct request_queue q, struct request rq)
	227	{
	228	struct elevator_queue *e = q->elevator;
	229
c51ca6cf JA	230	if (e->type->ops.sq.elevator_deactivate_req_fn)
c51ca6cf JA	231	e->type->ops.sq.elevator_deactivate_req_fn(q, rq);
158dbda0 TH	232	}
158dbda0 TH	233
83d016ac BVA	234	int elv_register_queue(struct request_queue *q);
	235	void elv_unregister_queue(struct request_queue *q);
	236
807d4af2 CH	237	struct hd_struct __disk_get_part(struct gendisk disk, int partno);
807d4af2 CH	238
581d4e28 JA	239	#ifdef CONFIG_FAIL_IO_TIMEOUT
	240	int blk_should_fake_timeout(struct request_queue *);
	241	ssize_t part_timeout_show(struct device , struct device_attribute , char *);
	242	ssize_t part_timeout_store(struct device , struct device_attribute ,
	243	const char *, size_t);
	244	#else
	245	static inline int blk_should_fake_timeout(struct request_queue *q)
	246	{
	247	return 0;
	248	}
	249	#endif
	250
d6d48196 JA	251	int ll_back_merge_fn(struct request_queue q, struct request req,
	252	struct bio *bio);
	253	int ll_front_merge_fn(struct request_queue q, struct request req,
	254	struct bio *bio);
b973cb7e JA	255	struct request attempt_back_merge(struct request_queue q, struct request *rq);
b973cb7e JA	256	struct request attempt_front_merge(struct request_queue q, struct request *rq);
5e84ea3a JA	257	int blk_attempt_req_merge(struct request_queue q, struct request rq,
5e84ea3a JA	258	struct request *next);
d6d48196	259	void blk_recalc_rq_segments(struct request *rq);
80a761fd	260	void blk_rq_set_mixed_merge(struct request *rq);
050c8ea8	261	bool blk_rq_merge_ok(struct request rq, struct bio bio);
34fe7c05	262	enum elv_merge blk_try_merge(struct request rq, struct bio bio);
d6d48196	263
8324aa91 JA	264	void blk_queue_congestion_threshold(struct request_queue *q);
8324aa91 JA	265
ff88972c AB	266	int blk_dev_init(void);
ff88972c AB	267
f253b86b	268
8324aa91 JA	269	/*
	270	* Return the threshold (number of used requests) at which the queue is
	271	* considered to be congested. It include a little hysteresis to keep the
	272	* context switch rate down.
	273	*/
	274	static inline int queue_congestion_on_threshold(struct request_queue *q)
	275	{
	276	return q->nr_congestion_on;
	277	}
	278
	279	/*
	280	* The threshold at which a queue is considered to be uncongested
	281	*/
	282	static inline int queue_congestion_off_threshold(struct request_queue *q)
	283	{
	284	return q->nr_congestion_off;
	285	}
	286
e3a2b3f9 JA	287	extern int blk_update_nr_requests(struct request_queue *, unsigned int);
e3a2b3f9 JA	288
c2553b58 JA	289	/*
	290	* Contribute to IO statistics IFF:
	291	*
	292	* a) it's attached to a gendisk, and
	293	* b) the queue had IO stats enabled when this request was started, and
e2a60da7	294	* c) it's a file system request
c2553b58	295	*/
26308eab	296	static inline int blk_do_io_stat(struct request *rq)
fb8ec18c	297	{
33659ebb	298	return rq->rq_disk &&
e8064021	299	(rq->rq_flags & RQF_IO_STAT) &&
57292b58	300	!blk_rq_is_passthrough(rq);
fb8ec18c JA	301	}
fb8ec18c JA	302
6cf7677f CH	303	static inline void req_set_nomerge(struct request_queue q, struct request req)
	304	{
	305	req->cmd_flags \|= REQ_NOMERGE;
	306	if (req == q->last_merge)
	307	q->last_merge = NULL;
	308	}
	309
0a72e7f4 JA	310	/*
	311	* Steal a bit from this field for legacy IO path atomic IO marking. Note that
	312	* setting the deadline clears the bottom bit, potentially clearing the
	313	* completed bit. The user has to be OK with this (current ones are fine).
	314	*/
	315	static inline void blk_rq_set_deadline(struct request *rq, unsigned long time)
	316	{
	317	rq->__deadline = time & ~0x1UL;
	318	}
	319
	320	static inline unsigned long blk_rq_deadline(struct request *rq)
	321	{
	322	return rq->__deadline & ~0x1UL;
	323	}
	324
f2dbd76a TH	325	/*
	326	* Internal io_context interface
	327	*/
	328	void get_io_context(struct io_context *ioc);
47fdd4ca	329	struct io_cq ioc_lookup_icq(struct io_context ioc, struct request_queue *q);
24acfc34 TH	330	struct io_cq ioc_create_icq(struct io_context ioc, struct request_queue *q,
24acfc34 TH	331	gfp_t gfp_mask);
7e5a8794	332	void ioc_clear_queue(struct request_queue *q);
f2dbd76a	333
24acfc34	334	int create_task_io_context(struct task_struct *task, gfp_t gfp_mask, int node);
f2dbd76a	335
c23ecb42 JA	336	/**
	337	* rq_ioc - determine io_context for request allocation
	338	* @bio: request being allocated is for this bio (can be %NULL)
	339	*
	340	* Determine io_context to use for request allocation for @bio. May return
	341	* %NULL if %current->io_context doesn't exist.
	342	*/
	343	static inline struct io_context rq_ioc(struct bio bio)
	344	{
	345	#ifdef CONFIG_BLK_CGROUP
	346	if (bio && bio->bi_ioc)
	347	return bio->bi_ioc;
	348	#endif
	349	return current->io_context;
	350	}
	351
f2dbd76a TH	352	/**
f2dbd76a TH	353	* create_io_context - try to create task->io_context
f2dbd76a TH	354	* @gfp_mask: allocation mask
	355	* @node: allocation node
	356	*
24acfc34 TH	357	* If %current->io_context is %NULL, allocate a new io_context and install
	358	* it. Returns the current %current->io_context which may be %NULL if
	359	* allocation failed.
f2dbd76a TH	360	*
f2dbd76a TH	361	* Note that this function can't be called with IRQ disabled because
24acfc34	362	* task_lock which protects %current->io_context is IRQ-unsafe.
f2dbd76a	363	*/
24acfc34	364	static inline struct io_context *create_io_context(gfp_t gfp_mask, int node)
f2dbd76a TH	365	{
f2dbd76a TH	366	WARN_ON_ONCE(irqs_disabled());
24acfc34 TH	367	if (unlikely(!current->io_context))
	368	create_task_io_context(current, gfp_mask, node);
	369	return current->io_context;
f2dbd76a TH	370	}
	371
	372	/*
	373	* Internal throttling interface
	374	*/
bc9fcbf9	375	#ifdef CONFIG_BLK_DEV_THROTTLING
c9a929dd	376	extern void blk_throtl_drain(struct request_queue *q);
bc9fcbf9 TH	377	extern int blk_throtl_init(struct request_queue *q);
bc9fcbf9 TH	378	extern void blk_throtl_exit(struct request_queue *q);
d61fcfa4	379	extern void blk_throtl_register_queue(struct request_queue *q);
bc9fcbf9	380	#else /* CONFIG_BLK_DEV_THROTTLING */
c9a929dd	381	static inline void blk_throtl_drain(struct request_queue *q) { }
bc9fcbf9 TH	382	static inline int blk_throtl_init(struct request_queue *q) { return 0; }
bc9fcbf9 TH	383	static inline void blk_throtl_exit(struct request_queue *q) { }
d61fcfa4	384	static inline void blk_throtl_register_queue(struct request_queue *q) { }
bc9fcbf9	385	#endif /* CONFIG_BLK_DEV_THROTTLING */
297e3d85 SL	386	#ifdef CONFIG_BLK_DEV_THROTTLING_LOW
	387	extern ssize_t blk_throtl_sample_time_show(struct request_queue q, char page);
	388	extern ssize_t blk_throtl_sample_time_store(struct request_queue *q,
	389	const char *page, size_t count);
9e234eea	390	extern void blk_throtl_bio_endio(struct bio *bio);
b9147dd1	391	extern void blk_throtl_stat_add(struct request *rq, u64 time);
9e234eea SL	392	#else
9e234eea SL	393	static inline void blk_throtl_bio_endio(struct bio *bio) { }
b9147dd1	394	static inline void blk_throtl_stat_add(struct request *rq, u64 time) { }
297e3d85	395	#endif
bc9fcbf9	396
3bce016a CH	397	#ifdef CONFIG_BOUNCE
	398	extern int init_emergency_isa_pool(void);
	399	extern void blk_queue_bounce(struct request_queue q, struct bio *bio);
	400	#else
	401	static inline int init_emergency_isa_pool(void)
	402	{
	403	return 0;
	404	}
	405	static inline void blk_queue_bounce(struct request_queue q, struct bio *bio)
	406	{
	407	}
	408	#endif /* CONFIG_BOUNCE */
	409
454be724 ML	410	extern void blk_drain_queue(struct request_queue *q);
454be724 ML	411
bc9fcbf9	412	#endif /* BLK_INTERNAL_H */