#ifndef BLK_INTERNAL_H#define BLK_INTERNAL_H #include <linux/idr.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;extern struct ida blk_queue_ida; static inline void __blk_get_queue(struct request_queue *q){	kobject_get(&q->kobj);} 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);int blk_rq_append_bio(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_dequeue_request(struct request *rq);void __blk_queue_free_tags(struct request_queue *q);bool __blk_end_bidi_request(struct request *rq, int error,			    unsigned int nr_bytes, unsigned int bidi_bytes); void blk_rq_timed_out_timer(unsigned long data);void blk_delete_timer(struct request *);void blk_add_timer(struct request *);void __generic_unplug_device(struct request_queue *); /* * 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 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)		(!hlist_unhashed(&(rq)->hash)) void blk_insert_flush(struct request *rq);void blk_abort_flushes(struct request_queue *q); static inline struct request *__elv_next_request(struct request_queue *q){	struct request *rq; 	while (1) {		if (!list_empty(&q->queue_head)) {			rq = list_entry_rq(q->queue_head.next);			return rq;		} 		/*		 * Flush request is running and flush request isn't queueable		 * in the drive, we can hold the queue till flush request is		 * finished. Even we don't do this, driver can't dispatch next		 * requests and will requeue them. And this can improve		 * throughput too. For example, we have request flush1, write1,		 * flush 2. flush1 is dispatched, then queue is hold, write1		 * isn't inserted to queue. After flush1 is finished, flush2		 * will be dispatched. Since disk cache is already clean,		 * flush2 will be finished very soon, so looks like flush2 is		 * folded to flush1.		 * Since the queue is hold, a flag is set to indicate the queue		 * should be restarted later. Please see flush_end_io() for		 * details.		 */		if (q->flush_pending_idx != q->flush_running_idx &&				!queue_flush_queueable(q)) {			q->flush_queue_delayed = 1;			return NULL;		}		if (unlikely(blk_queue_dead(q)) ||		    !q->elevator->type->ops.elevator_dispatch_fn(q, 0))			return NULL;	}} static inline void elv_activate_rq(struct request_queue *q, struct request *rq){	struct elevator_queue *e = q->elevator; 	if (e->type->ops.elevator_activate_req_fn)		e->type->ops.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.elevator_deactivate_req_fn)		e->type->ops.elevator_deactivate_req_fn(q, rq);} #ifdef CONFIG_FAIL_IO_TIMEOUTint 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);#elsestatic 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);int attempt_back_merge(struct request_queue *q, struct request *rq);int 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);int 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;} /* * 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 or a discard request */static inline int blk_do_io_stat(struct request *rq){	return rq->rq_disk &&	       (rq->cmd_flags & REQ_IO_STAT) &&	       (rq->cmd_type == REQ_TYPE_FS ||	        (rq->cmd_flags & REQ_DISCARD));} /* * 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); /** * 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_THROTTLINGextern bool blk_throtl_bio(struct request_queue *q, struct bio *bio);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);#else /* CONFIG_BLK_DEV_THROTTLING */static inline bool blk_throtl_bio(struct request_queue *q, struct bio *bio){	return false;}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) { }#endif /* CONFIG_BLK_DEV_THROTTLING */ #endif /* BLK_INTERNAL_H */