1#ifndef BLK_INTERNAL_H 2#define BLK_INTERNAL_H 3 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 10extern struct kmem_cache *blk_requestq_cachep; 11extern struct kobj_type blk_queue_ktype; 12 13void init_request_from_bio(struct request *req, struct bio *bio); 14void blk_rq_bio_prep(struct request_queue *q, struct request *rq, 15 struct bio *bio); 16int blk_rq_append_bio(struct request_queue *q, struct request *rq, 17 struct bio *bio); 18void blk_dequeue_request(struct request *rq); 19void __blk_queue_free_tags(struct request_queue *q); 20 21void blk_unplug_work(struct work_struct *work); 22void blk_unplug_timeout(unsigned long data); 23void blk_rq_timed_out_timer(unsigned long data); 24void blk_delete_timer(struct request *); 25void blk_add_timer(struct request *); 26void __generic_unplug_device(struct request_queue *); 27 28/* 29 * Internal atomic flags for request handling 30 */ 31enum rq_atomic_flags { 32 REQ_ATOM_COMPLETE = 0, 33}; 34 35/* 36 * EH timer and IO completion will both attempt to 'grab' the request, make 37 * sure that only one of them suceeds 38 */ 39static inline int blk_mark_rq_complete(struct request *rq) 40{ 41 return test_and_set_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags); 42} 43 44static inline void blk_clear_rq_complete(struct request *rq) 45{ 46 clear_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags); 47} 48 49/* 50 * Internal elevator interface 51 */ 52#define ELV_ON_HASH(rq) (!hlist_unhashed(&(rq)->hash)) 53 54static inline struct request *__elv_next_request(struct request_queue *q) 55{ 56 struct request *rq; 57 58 while (1) { 59 while (!list_empty(&q->queue_head)) { 60 rq = list_entry_rq(q->queue_head.next); 61 if (blk_do_ordered(q, &rq)) 62 return rq; 63 } 64 65 if (!q->elevator->ops->elevator_dispatch_fn(q, 0)) 66 return NULL; 67 } 68} 69 70static inline void elv_activate_rq(struct request_queue *q, struct request *rq) 71{ 72 struct elevator_queue *e = q->elevator; 73 74 if (e->ops->elevator_activate_req_fn) 75 e->ops->elevator_activate_req_fn(q, rq); 76} 77 78static inline void elv_deactivate_rq(struct request_queue *q, struct request *rq) 79{ 80 struct elevator_queue *e = q->elevator; 81 82 if (e->ops->elevator_deactivate_req_fn) 83 e->ops->elevator_deactivate_req_fn(q, rq); 84} 85 86#ifdef CONFIG_FAIL_IO_TIMEOUT 87int blk_should_fake_timeout(struct request_queue *); 88ssize_t part_timeout_show(struct device *, struct device_attribute *, char *); 89ssize_t part_timeout_store(struct device *, struct device_attribute *, 90 const char *, size_t); 91#else 92static inline int blk_should_fake_timeout(struct request_queue *q) 93{ 94 return 0; 95} 96#endif 97 98struct io_context *current_io_context(gfp_t gfp_flags, int node); 99 100int ll_back_merge_fn(struct request_queue *q, struct request *req, 101 struct bio *bio); 102int ll_front_merge_fn(struct request_queue *q, struct request *req, 103 struct bio *bio); 104int attempt_back_merge(struct request_queue *q, struct request *rq); 105int attempt_front_merge(struct request_queue *q, struct request *rq); 106void blk_recalc_rq_segments(struct request *rq); 107void blk_rq_set_mixed_merge(struct request *rq); 108 109void blk_queue_congestion_threshold(struct request_queue *q); 110 111int blk_dev_init(void); 112 113void elv_quiesce_start(struct request_queue *q); 114void elv_quiesce_end(struct request_queue *q); 115 116 117/* 118 * Return the threshold (number of used requests) at which the queue is 119 * considered to be congested. It include a little hysteresis to keep the 120 * context switch rate down. 121 */ 122static inline int queue_congestion_on_threshold(struct request_queue *q) 123{ 124 return q->nr_congestion_on; 125} 126 127/* 128 * The threshold at which a queue is considered to be uncongested 129 */ 130static inline int queue_congestion_off_threshold(struct request_queue *q) 131{ 132 return q->nr_congestion_off; 133} 134 135#if defined(CONFIG_BLK_DEV_INTEGRITY) 136 137#define rq_for_each_integrity_segment(bvl, _rq, _iter) \ 138 __rq_for_each_bio(_iter.bio, _rq) \ 139 bip_for_each_vec(bvl, _iter.bio->bi_integrity, _iter.i) 140 141#endif /* BLK_DEV_INTEGRITY */ 142 143static inline int blk_cpu_to_group(int cpu) 144{ 145 int group = NR_CPUS; 146#ifdef CONFIG_SCHED_MC 147 const struct cpumask *mask = cpu_coregroup_mask(cpu); 148 group = cpumask_first(mask); 149#elif defined(CONFIG_SCHED_SMT) 150 group = cpumask_first(topology_thread_cpumask(cpu)); 151#else 152 return cpu; 153#endif 154 if (likely(group < NR_CPUS)) 155 return group; 156 return cpu; 157} 158 159/* 160 * Contribute to IO statistics IFF: 161 * 162 * a) it's attached to a gendisk, and 163 * b) the queue had IO stats enabled when this request was started, and 164 * c) it's a file system request or a discard request 165 */ 166static inline int blk_do_io_stat(struct request *rq) 167{ 168 return rq->rq_disk && 169 (rq->cmd_flags & REQ_IO_STAT) && 170 (rq->cmd_type == REQ_TYPE_FS || 171 (rq->cmd_flags & REQ_DISCARD)); 172} 173 174#endif 175