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 10 extern struct kmem_cache *blk_requestq_cachep; 11 extern struct kobj_type blk_queue_ktype; 12 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); 16 int blk_rq_append_bio(struct request_queue *q, struct request *rq, 17 struct bio *bio); 18 void blk_dequeue_request(struct request *rq); 19 void __blk_queue_free_tags(struct request_queue *q); 20 21 void blk_unplug_work(struct work_struct *work); 22 void blk_unplug_timeout(unsigned long data); 23 void blk_rq_timed_out_timer(unsigned long data); 24 void blk_delete_timer(struct request *); 25 void blk_add_timer(struct request *); 26 void __generic_unplug_device(struct request_queue *); 27 28 /* 29 * Internal atomic flags for request handling 30 */ 31 enum 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 */ 39 static inline int blk_mark_rq_complete(struct request *rq) 40 { 41 return test_and_set_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags); 42 } 43 44 static 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 54 static 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 70 static 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 78 static 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 87 int blk_should_fake_timeout(struct request_queue *); 88 ssize_t part_timeout_show(struct device *, struct device_attribute *, char *); 89 ssize_t part_timeout_store(struct device *, struct device_attribute *, 90 const char *, size_t); 91 #else 92 static inline int blk_should_fake_timeout(struct request_queue *q) 93 { 94 return 0; 95 } 96 #endif 97 98 struct io_context *current_io_context(gfp_t gfp_flags, int node); 99 100 int ll_back_merge_fn(struct request_queue *q, struct request *req, 101 struct bio *bio); 102 int ll_front_merge_fn(struct request_queue *q, struct request *req, 103 struct bio *bio); 104 int attempt_back_merge(struct request_queue *q, struct request *rq); 105 int attempt_front_merge(struct request_queue *q, struct request *rq); 106 void blk_recalc_rq_segments(struct request *rq); 107 108 void blk_queue_congestion_threshold(struct request_queue *q); 109 110 int blk_dev_init(void); 111 112 void elv_quiesce_start(struct request_queue *q); 113 void elv_quiesce_end(struct request_queue *q); 114 115 116 /* 117 * Return the threshold (number of used requests) at which the queue is 118 * considered to be congested. It include a little hysteresis to keep the 119 * context switch rate down. 120 */ 121 static inline int queue_congestion_on_threshold(struct request_queue *q) 122 { 123 return q->nr_congestion_on; 124 } 125 126 /* 127 * The threshold at which a queue is considered to be uncongested 128 */ 129 static inline int queue_congestion_off_threshold(struct request_queue *q) 130 { 131 return q->nr_congestion_off; 132 } 133 134 #if defined(CONFIG_BLK_DEV_INTEGRITY) 135 136 #define rq_for_each_integrity_segment(bvl, _rq, _iter) \ 137 __rq_for_each_bio(_iter.bio, _rq) \ 138 bip_for_each_vec(bvl, _iter.bio->bi_integrity, _iter.i) 139 140 #endif /* BLK_DEV_INTEGRITY */ 141 142 static inline int blk_cpu_to_group(int cpu) 143 { 144 #ifdef CONFIG_SCHED_MC 145 const struct cpumask *mask = cpu_coregroup_mask(cpu); 146 return cpumask_first(mask); 147 #elif defined(CONFIG_SCHED_SMT) 148 return cpumask_first(topology_thread_cpumask(cpu)); 149 #else 150 return cpu; 151 #endif 152 } 153 154 /* 155 * Contribute to IO statistics IFF: 156 * 157 * a) it's attached to a gendisk, and 158 * b) the queue had IO stats enabled when this request was started, and 159 * c) it's a file system request or a discard request 160 */ 161 static inline int blk_do_io_stat(struct request *rq) 162 { 163 return rq->rq_disk && blk_rq_io_stat(rq) && 164 (blk_fs_request(rq) || blk_discard_rq(rq)); 165 } 166 167 #endif 168