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 struct request *blk_do_flush(struct request_queue *q, struct request *rq); 55 56 static inline struct request *__elv_next_request(struct request_queue *q) 57 { 58 struct request *rq; 59 60 while (1) { 61 while (!list_empty(&q->queue_head)) { 62 rq = list_entry_rq(q->queue_head.next); 63 if (!(rq->cmd_flags & (REQ_FLUSH | REQ_FUA)) || 64 rq == &q->flush_rq) 65 return rq; 66 rq = blk_do_flush(q, rq); 67 if (rq) 68 return rq; 69 } 70 71 if (!q->elevator->ops->elevator_dispatch_fn(q, 0)) 72 return NULL; 73 } 74 } 75 76 static inline void elv_activate_rq(struct request_queue *q, struct request *rq) 77 { 78 struct elevator_queue *e = q->elevator; 79 80 if (e->ops->elevator_activate_req_fn) 81 e->ops->elevator_activate_req_fn(q, rq); 82 } 83 84 static inline void elv_deactivate_rq(struct request_queue *q, struct request *rq) 85 { 86 struct elevator_queue *e = q->elevator; 87 88 if (e->ops->elevator_deactivate_req_fn) 89 e->ops->elevator_deactivate_req_fn(q, rq); 90 } 91 92 #ifdef CONFIG_FAIL_IO_TIMEOUT 93 int blk_should_fake_timeout(struct request_queue *); 94 ssize_t part_timeout_show(struct device *, struct device_attribute *, char *); 95 ssize_t part_timeout_store(struct device *, struct device_attribute *, 96 const char *, size_t); 97 #else 98 static inline int blk_should_fake_timeout(struct request_queue *q) 99 { 100 return 0; 101 } 102 #endif 103 104 struct io_context *current_io_context(gfp_t gfp_flags, int node); 105 106 int ll_back_merge_fn(struct request_queue *q, struct request *req, 107 struct bio *bio); 108 int ll_front_merge_fn(struct request_queue *q, struct request *req, 109 struct bio *bio); 110 int attempt_back_merge(struct request_queue *q, struct request *rq); 111 int attempt_front_merge(struct request_queue *q, struct request *rq); 112 void blk_recalc_rq_segments(struct request *rq); 113 void blk_rq_set_mixed_merge(struct request *rq); 114 115 void blk_queue_congestion_threshold(struct request_queue *q); 116 117 int blk_dev_init(void); 118 119 void elv_quiesce_start(struct request_queue *q); 120 void elv_quiesce_end(struct request_queue *q); 121 122 123 /* 124 * Return the threshold (number of used requests) at which the queue is 125 * considered to be congested. It include a little hysteresis to keep the 126 * context switch rate down. 127 */ 128 static inline int queue_congestion_on_threshold(struct request_queue *q) 129 { 130 return q->nr_congestion_on; 131 } 132 133 /* 134 * The threshold at which a queue is considered to be uncongested 135 */ 136 static inline int queue_congestion_off_threshold(struct request_queue *q) 137 { 138 return q->nr_congestion_off; 139 } 140 141 static inline int blk_cpu_to_group(int cpu) 142 { 143 int group = NR_CPUS; 144 #ifdef CONFIG_SCHED_MC 145 const struct cpumask *mask = cpu_coregroup_mask(cpu); 146 group = cpumask_first(mask); 147 #elif defined(CONFIG_SCHED_SMT) 148 group = cpumask_first(topology_thread_cpumask(cpu)); 149 #else 150 return cpu; 151 #endif 152 if (likely(group < NR_CPUS)) 153 return group; 154 return cpu; 155 } 156 157 /* 158 * Contribute to IO statistics IFF: 159 * 160 * a) it's attached to a gendisk, and 161 * b) the queue had IO stats enabled when this request was started, and 162 * c) it's a file system request or a discard request 163 */ 164 static inline int blk_do_io_stat(struct request *rq) 165 { 166 return rq->rq_disk && 167 (rq->cmd_flags & REQ_IO_STAT) && 168 (rq->cmd_type == REQ_TYPE_FS || 169 (rq->cmd_flags & REQ_DISCARD)); 170 } 171 172 #endif 173