[mirror_ubuntu-bionic-kernel.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;

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);

/*
 * Internal atomic flags for request handling
 */
enum rq_atomic_flags {
	/*
	 * Keep these two bits first - not because we depend on the
	 * value of them, but we do depend on them being in the same
	 * byte of storage to ensure ordering on writes. Keeping them
	 * first will achieve that nicely.
	 */
	REQ_ATOM_COMPLETE = 0,
	REQ_ATOM_STARTED,

	REQ_ATOM_POLL_SLEPT,
};

/*
 * EH timer and IO completion will both attempt to 'grab' the request, make
 * sure that only one of them succeeds
 */
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);
}

/*
 * 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);
}

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;
}

/*
 * 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
	1	/* SPDX-License-Identifier: GPL-2.0 */
	2	#ifndef BLK_INTERNAL_H
	3	#define BLK_INTERNAL_H
	4
	5	#include <linux/idr.h>
	6	#include <linux/blk-mq.h>
	7	#include "blk-mq.h"
	8
	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
	15	/* Max future timer expiry for timeouts */
	16	#define BLK_MAX_TIMEOUT (5 * HZ)
	17
	18	#ifdef CONFIG_DEBUG_FS
	19	extern struct dentry *blk_debugfs_root;
	20	#endif
	21
	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;
	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;
	36	spinlock_t mq_flush_lock;
	37	};
	38
	39	extern struct kmem_cache *blk_requestq_cachep;
	40	extern struct kmem_cache *request_cachep;
	41	extern struct kobj_type blk_queue_ktype;
	42	extern struct ida blk_queue_ida;
	43
	44	static inline struct blk_flush_queue *blk_get_flush_queue(
	45	struct request_queue q, struct blk_mq_ctx ctx)
	46	{
	47	if (q->mq_ops)
	48	return blk_mq_map_queue(q, ctx->cpu)->fq;
	49	return q->fq;
	50	}
	51
	52	static inline void __blk_get_queue(struct request_queue *q)
	53	{
	54	kobject_get(&q->kobj);
	55	}
	56
	57	struct blk_flush_queue blk_alloc_flush_queue(struct request_queue q,
	58	int node, int cmd_size);
	59	void blk_free_flush_queue(struct blk_flush_queue *q);
	60
	61	int blk_init_rl(struct request_list rl, struct request_queue q,
	62	gfp_t gfp_mask);
	63	void blk_exit_rl(struct request_queue q, struct request_list rl);
	64	void blk_rq_bio_prep(struct request_queue q, struct request rq,
	65	struct bio *bio);
	66	void blk_queue_bypass_start(struct request_queue *q);
	67	void blk_queue_bypass_end(struct request_queue *q);
	68	void __blk_queue_free_tags(struct request_queue *q);
	69	void blk_freeze_queue(struct request_queue *q);
	70
	71	static inline void blk_queue_enter_live(struct request_queue *q)
	72	{
	73	/*
	74	* Given that running in generic_make_request() context
	75	* guarantees that a live reference against q_usage_counter has
	76	* been established, further references under that same context
	77	* need not check that the queue has been frozen (marked dead).
	78	*/
	79	percpu_ref_get(&q->q_usage_counter);
	80	}
	81
	82	#ifdef CONFIG_BLK_DEV_INTEGRITY
	83	void blk_flush_integrity(void);
	84	bool __bio_integrity_endio(struct bio *);
	85	static inline bool bio_integrity_endio(struct bio *bio)
	86	{
	87	if (bio_integrity(bio))
	88	return __bio_integrity_endio(bio);
	89	return true;
	90	}
	91	#else
	92	static inline void blk_flush_integrity(void)
	93	{
	94	}
	95	static inline bool bio_integrity_endio(struct bio *bio)
	96	{
	97	return true;
	98	}
	99	#endif
	100
	101	void blk_timeout_work(struct work_struct *work);
	102	unsigned long blk_rq_timeout(unsigned long timeout);
	103	void blk_add_timer(struct request *req);
	104	void blk_delete_timer(struct request *);
	105
	106
	107	bool bio_attempt_front_merge(struct request_queue q, struct request req,
	108	struct bio *bio);
	109	bool bio_attempt_back_merge(struct request_queue q, struct request req,
	110	struct bio *bio);
	111	bool bio_attempt_discard_merge(struct request_queue q, struct request req,
	112	struct bio *bio);
	113	bool blk_attempt_plug_merge(struct request_queue q, struct bio bio,
	114	unsigned int *request_count,
	115	struct request **same_queue_rq);
	116	unsigned int blk_plug_queued_count(struct request_queue *q);
	117
	118	void blk_account_io_start(struct request *req, bool new_io);
	119	void blk_account_io_completion(struct request *req, unsigned int bytes);
	120	void blk_account_io_done(struct request *req);
	121
	122	/*
	123	* Internal atomic flags for request handling
	124	*/
	125	enum rq_atomic_flags {
	126	/*
	127	* Keep these two bits first - not because we depend on the
	128	* value of them, but we do depend on them being in the same
	129	* byte of storage to ensure ordering on writes. Keeping them
	130	* first will achieve that nicely.
	131	*/
	132	REQ_ATOM_COMPLETE = 0,
	133	REQ_ATOM_STARTED,
	134
	135	REQ_ATOM_POLL_SLEPT,
	136	};
	137
	138	/*
	139	* EH timer and IO completion will both attempt to 'grab' the request, make
	140	* sure that only one of them succeeds
	141	*/
	142	static inline int blk_mark_rq_complete(struct request *rq)
	143	{
	144	return test_and_set_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags);
	145	}
	146
	147	static inline void blk_clear_rq_complete(struct request *rq)
	148	{
	149	clear_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags);
	150	}
	151
	152	/*
	153	* Internal elevator interface
	154	*/
	155	#define ELV_ON_HASH(rq) ((rq)->rq_flags & RQF_HASHED)
	156
	157	void blk_insert_flush(struct request *rq);
	158
	159	static inline void elv_activate_rq(struct request_queue q, struct request rq)
	160	{
	161	struct elevator_queue *e = q->elevator;
	162
	163	if (e->type->ops.sq.elevator_activate_req_fn)
	164	e->type->ops.sq.elevator_activate_req_fn(q, rq);
	165	}
	166
	167	static inline void elv_deactivate_rq(struct request_queue q, struct request rq)
	168	{
	169	struct elevator_queue *e = q->elevator;
	170
	171	if (e->type->ops.sq.elevator_deactivate_req_fn)
	172	e->type->ops.sq.elevator_deactivate_req_fn(q, rq);
	173	}
	174
	175	struct hd_struct __disk_get_part(struct gendisk disk, int partno);
	176
	177	#ifdef CONFIG_FAIL_IO_TIMEOUT
	178	int blk_should_fake_timeout(struct request_queue *);
	179	ssize_t part_timeout_show(struct device , struct device_attribute , char *);
	180	ssize_t part_timeout_store(struct device , struct device_attribute ,
	181	const char *, size_t);
	182	#else
	183	static inline int blk_should_fake_timeout(struct request_queue *q)
	184	{
	185	return 0;
	186	}
	187	#endif
	188
	189	int ll_back_merge_fn(struct request_queue q, struct request req,
	190	struct bio *bio);
	191	int ll_front_merge_fn(struct request_queue q, struct request req,
	192	struct bio *bio);
	193	struct request attempt_back_merge(struct request_queue q, struct request *rq);
	194	struct request attempt_front_merge(struct request_queue q, struct request *rq);
	195	int blk_attempt_req_merge(struct request_queue q, struct request rq,
	196	struct request *next);
	197	void blk_recalc_rq_segments(struct request *rq);
	198	void blk_rq_set_mixed_merge(struct request *rq);
	199	bool blk_rq_merge_ok(struct request rq, struct bio bio);
	200	enum elv_merge blk_try_merge(struct request rq, struct bio bio);
	201
	202	void blk_queue_congestion_threshold(struct request_queue *q);
	203
	204	int blk_dev_init(void);
	205
	206
	207	/*
	208	* Return the threshold (number of used requests) at which the queue is
	209	* considered to be congested. It include a little hysteresis to keep the
	210	* context switch rate down.
	211	*/
	212	static inline int queue_congestion_on_threshold(struct request_queue *q)
	213	{
	214	return q->nr_congestion_on;
	215	}
	216
	217	/*
	218	* The threshold at which a queue is considered to be uncongested
	219	*/
	220	static inline int queue_congestion_off_threshold(struct request_queue *q)
	221	{
	222	return q->nr_congestion_off;
	223	}
	224
	225	extern int blk_update_nr_requests(struct request_queue *, unsigned int);
	226
	227	/*
	228	* Contribute to IO statistics IFF:
	229	*
	230	* a) it's attached to a gendisk, and
	231	* b) the queue had IO stats enabled when this request was started, and
	232	* c) it's a file system request
	233	*/
	234	static inline int blk_do_io_stat(struct request *rq)
	235	{
	236	return rq->rq_disk &&
	237	(rq->rq_flags & RQF_IO_STAT) &&
	238	!blk_rq_is_passthrough(rq);
	239	}
	240
	241	static inline void req_set_nomerge(struct request_queue q, struct request req)
	242	{
	243	req->cmd_flags \|= REQ_NOMERGE;
	244	if (req == q->last_merge)
	245	q->last_merge = NULL;
	246	}
	247
	248	/*
	249	* Internal io_context interface
	250	*/
	251	void get_io_context(struct io_context *ioc);
	252	struct io_cq ioc_lookup_icq(struct io_context ioc, struct request_queue *q);
	253	struct io_cq ioc_create_icq(struct io_context ioc, struct request_queue *q,
	254	gfp_t gfp_mask);
	255	void ioc_clear_queue(struct request_queue *q);
	256
	257	int create_task_io_context(struct task_struct *task, gfp_t gfp_mask, int node);
	258
	259	/**
	260	* rq_ioc - determine io_context for request allocation
	261	* @bio: request being allocated is for this bio (can be %NULL)
	262	*
	263	* Determine io_context to use for request allocation for @bio. May return
	264	* %NULL if %current->io_context doesn't exist.
	265	*/
	266	static inline struct io_context rq_ioc(struct bio bio)
	267	{
	268	#ifdef CONFIG_BLK_CGROUP
	269	if (bio && bio->bi_ioc)
	270	return bio->bi_ioc;
	271	#endif
	272	return current->io_context;
	273	}
	274
	275	/**
	276	* create_io_context - try to create task->io_context
	277	* @gfp_mask: allocation mask
	278	* @node: allocation node
	279	*
	280	* If %current->io_context is %NULL, allocate a new io_context and install
	281	* it. Returns the current %current->io_context which may be %NULL if
	282	* allocation failed.
	283	*
	284	* Note that this function can't be called with IRQ disabled because
	285	* task_lock which protects %current->io_context is IRQ-unsafe.
	286	*/
	287	static inline struct io_context *create_io_context(gfp_t gfp_mask, int node)
	288	{
	289	WARN_ON_ONCE(irqs_disabled());
	290	if (unlikely(!current->io_context))
	291	create_task_io_context(current, gfp_mask, node);
	292	return current->io_context;
	293	}
	294
	295	/*
	296	* Internal throttling interface
	297	*/
	298	#ifdef CONFIG_BLK_DEV_THROTTLING
	299	extern void blk_throtl_drain(struct request_queue *q);
	300	extern int blk_throtl_init(struct request_queue *q);
	301	extern void blk_throtl_exit(struct request_queue *q);
	302	extern void blk_throtl_register_queue(struct request_queue *q);
	303	#else /* CONFIG_BLK_DEV_THROTTLING */
	304	static inline void blk_throtl_drain(struct request_queue *q) { }
	305	static inline int blk_throtl_init(struct request_queue *q) { return 0; }
	306	static inline void blk_throtl_exit(struct request_queue *q) { }
	307	static inline void blk_throtl_register_queue(struct request_queue *q) { }
	308	#endif /* CONFIG_BLK_DEV_THROTTLING */
	309	#ifdef CONFIG_BLK_DEV_THROTTLING_LOW
	310	extern ssize_t blk_throtl_sample_time_show(struct request_queue q, char page);
	311	extern ssize_t blk_throtl_sample_time_store(struct request_queue *q,
	312	const char *page, size_t count);
	313	extern void blk_throtl_bio_endio(struct bio *bio);
	314	extern void blk_throtl_stat_add(struct request *rq, u64 time);
	315	#else
	316	static inline void blk_throtl_bio_endio(struct bio *bio) { }
	317	static inline void blk_throtl_stat_add(struct request *rq, u64 time) { }
	318	#endif
	319
	320	#ifdef CONFIG_BOUNCE
	321	extern int init_emergency_isa_pool(void);
	322	extern void blk_queue_bounce(struct request_queue q, struct bio *bio);
	323	#else
	324	static inline int init_emergency_isa_pool(void)
	325	{
	326	return 0;
	327	}
	328	static inline void blk_queue_bounce(struct request_queue q, struct bio *bio)
	329	{
	330	}
	331	#endif /* CONFIG_BOUNCE */
	332
	333	extern void blk_drain_queue(struct request_queue *q);
	334
	335	#endif /* BLK_INTERNAL_H */