1 #ifndef BLK_INTERNAL_H 2 #define BLK_INTERNAL_H 3 4 #include <linux/idr.h> 5 6 /* Amount of time in which a process may batch requests */ 7 #define BLK_BATCH_TIME (HZ/50UL) 8 9 /* Number of requests a "batching" process may submit */ 10 #define BLK_BATCH_REQ 32 11 12 extern struct kmem_cache *blk_requestq_cachep; 13 extern struct kobj_type blk_queue_ktype; 14 extern struct ida blk_queue_ida; 15 16 static inline void __blk_get_queue(struct request_queue *q) 17 { 18 kobject_get(&q->kobj); 19 } 20 21 void init_request_from_bio(struct request *req, struct bio *bio); 22 void blk_rq_bio_prep(struct request_queue *q, struct request *rq, 23 struct bio *bio); 24 int blk_rq_append_bio(struct request_queue *q, struct request *rq, 25 struct bio *bio); 26 void blk_drain_queue(struct request_queue *q, bool drain_all); 27 void blk_dequeue_request(struct request *rq); 28 void __blk_queue_free_tags(struct request_queue *q); 29 bool __blk_end_bidi_request(struct request *rq, int error, 30 unsigned int nr_bytes, unsigned int bidi_bytes); 31 32 void blk_rq_timed_out_timer(unsigned long data); 33 void blk_delete_timer(struct request *); 34 void blk_add_timer(struct request *); 35 void __generic_unplug_device(struct request_queue *); 36 37 /* 38 * Internal atomic flags for request handling 39 */ 40 enum rq_atomic_flags { 41 REQ_ATOM_COMPLETE = 0, 42 }; 43 44 /* 45 * EH timer and IO completion will both attempt to 'grab' the request, make 46 * sure that only one of them succeeds 47 */ 48 static inline int blk_mark_rq_complete(struct request *rq) 49 { 50 return test_and_set_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags); 51 } 52 53 static inline void blk_clear_rq_complete(struct request *rq) 54 { 55 clear_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags); 56 } 57 58 /* 59 * Internal elevator interface 60 */ 61 #define ELV_ON_HASH(rq) (!hlist_unhashed(&(rq)->hash)) 62 63 void blk_insert_flush(struct request *rq); 64 void blk_abort_flushes(struct request_queue *q); 65 66 static inline struct request *__elv_next_request(struct request_queue *q) 67 { 68 struct request *rq; 69 70 while (1) { 71 if (!list_empty(&q->queue_head)) { 72 rq = list_entry_rq(q->queue_head.next); 73 return rq; 74 } 75 76 /* 77 * Flush request is running and flush request isn't queueable 78 * in the drive, we can hold the queue till flush request is 79 * finished. Even we don't do this, driver can't dispatch next 80 * requests and will requeue them. And this can improve 81 * throughput too. For example, we have request flush1, write1, 82 * flush 2. flush1 is dispatched, then queue is hold, write1 83 * isn't inserted to queue. After flush1 is finished, flush2 84 * will be dispatched. Since disk cache is already clean, 85 * flush2 will be finished very soon, so looks like flush2 is 86 * folded to flush1. 87 * Since the queue is hold, a flag is set to indicate the queue 88 * should be restarted later. Please see flush_end_io() for 89 * details. 90 */ 91 if (q->flush_pending_idx != q->flush_running_idx && 92 !queue_flush_queueable(q)) { 93 q->flush_queue_delayed = 1; 94 return NULL; 95 } 96 if (unlikely(blk_queue_dead(q)) || 97 !q->elevator->type->ops.elevator_dispatch_fn(q, 0)) 98 return NULL; 99 } 100 } 101 102 static inline void elv_activate_rq(struct request_queue *q, struct request *rq) 103 { 104 struct elevator_queue *e = q->elevator; 105 106 if (e->type->ops.elevator_activate_req_fn) 107 e->type->ops.elevator_activate_req_fn(q, rq); 108 } 109 110 static inline void elv_deactivate_rq(struct request_queue *q, struct request *rq) 111 { 112 struct elevator_queue *e = q->elevator; 113 114 if (e->type->ops.elevator_deactivate_req_fn) 115 e->type->ops.elevator_deactivate_req_fn(q, rq); 116 } 117 118 #ifdef CONFIG_FAIL_IO_TIMEOUT 119 int blk_should_fake_timeout(struct request_queue *); 120 ssize_t part_timeout_show(struct device *, struct device_attribute *, char *); 121 ssize_t part_timeout_store(struct device *, struct device_attribute *, 122 const char *, size_t); 123 #else 124 static inline int blk_should_fake_timeout(struct request_queue *q) 125 { 126 return 0; 127 } 128 #endif 129 130 int ll_back_merge_fn(struct request_queue *q, struct request *req, 131 struct bio *bio); 132 int ll_front_merge_fn(struct request_queue *q, struct request *req, 133 struct bio *bio); 134 int attempt_back_merge(struct request_queue *q, struct request *rq); 135 int attempt_front_merge(struct request_queue *q, struct request *rq); 136 int blk_attempt_req_merge(struct request_queue *q, struct request *rq, 137 struct request *next); 138 void blk_recalc_rq_segments(struct request *rq); 139 void blk_rq_set_mixed_merge(struct request *rq); 140 bool blk_rq_merge_ok(struct request *rq, struct bio *bio); 141 int blk_try_merge(struct request *rq, struct bio *bio); 142 143 void blk_queue_congestion_threshold(struct request_queue *q); 144 145 int blk_dev_init(void); 146 147 void elv_quiesce_start(struct request_queue *q); 148 void elv_quiesce_end(struct request_queue *q); 149 150 151 /* 152 * Return the threshold (number of used requests) at which the queue is 153 * considered to be congested. It include a little hysteresis to keep the 154 * context switch rate down. 155 */ 156 static inline int queue_congestion_on_threshold(struct request_queue *q) 157 { 158 return q->nr_congestion_on; 159 } 160 161 /* 162 * The threshold at which a queue is considered to be uncongested 163 */ 164 static inline int queue_congestion_off_threshold(struct request_queue *q) 165 { 166 return q->nr_congestion_off; 167 } 168 169 static inline int blk_cpu_to_group(int cpu) 170 { 171 int group = NR_CPUS; 172 #ifdef CONFIG_SCHED_MC 173 const struct cpumask *mask = cpu_coregroup_mask(cpu); 174 group = cpumask_first(mask); 175 #elif defined(CONFIG_SCHED_SMT) 176 group = cpumask_first(topology_thread_cpumask(cpu)); 177 #else 178 return cpu; 179 #endif 180 if (likely(group < NR_CPUS)) 181 return group; 182 return cpu; 183 } 184 185 /* 186 * Contribute to IO statistics IFF: 187 * 188 * a) it's attached to a gendisk, and 189 * b) the queue had IO stats enabled when this request was started, and 190 * c) it's a file system request or a discard request 191 */ 192 static inline int blk_do_io_stat(struct request *rq) 193 { 194 return rq->rq_disk && 195 (rq->cmd_flags & REQ_IO_STAT) && 196 (rq->cmd_type == REQ_TYPE_FS || 197 (rq->cmd_flags & REQ_DISCARD)); 198 } 199 200 /* 201 * Internal io_context interface 202 */ 203 void get_io_context(struct io_context *ioc); 204 struct io_cq *ioc_lookup_icq(struct io_context *ioc, struct request_queue *q); 205 struct io_cq *ioc_create_icq(struct request_queue *q, gfp_t gfp_mask); 206 void ioc_clear_queue(struct request_queue *q); 207 208 void create_io_context_slowpath(struct task_struct *task, gfp_t gfp_mask, 209 int node); 210 211 /** 212 * create_io_context - try to create task->io_context 213 * @task: target task 214 * @gfp_mask: allocation mask 215 * @node: allocation node 216 * 217 * If @task->io_context is %NULL, allocate a new io_context and install it. 218 * Returns the current @task->io_context which may be %NULL if allocation 219 * failed. 220 * 221 * Note that this function can't be called with IRQ disabled because 222 * task_lock which protects @task->io_context is IRQ-unsafe. 223 */ 224 static inline struct io_context *create_io_context(struct task_struct *task, 225 gfp_t gfp_mask, int node) 226 { 227 WARN_ON_ONCE(irqs_disabled()); 228 if (unlikely(!task->io_context)) 229 create_io_context_slowpath(task, gfp_mask, node); 230 return task->io_context; 231 } 232 233 /* 234 * Internal throttling interface 235 */ 236 #ifdef CONFIG_BLK_DEV_THROTTLING 237 extern bool blk_throtl_bio(struct request_queue *q, struct bio *bio); 238 extern void blk_throtl_drain(struct request_queue *q); 239 extern int blk_throtl_init(struct request_queue *q); 240 extern void blk_throtl_exit(struct request_queue *q); 241 extern void blk_throtl_release(struct request_queue *q); 242 #else /* CONFIG_BLK_DEV_THROTTLING */ 243 static inline bool blk_throtl_bio(struct request_queue *q, struct bio *bio) 244 { 245 return false; 246 } 247 static inline void blk_throtl_drain(struct request_queue *q) { } 248 static inline int blk_throtl_init(struct request_queue *q) { return 0; } 249 static inline void blk_throtl_exit(struct request_queue *q) { } 250 static inline void blk_throtl_release(struct request_queue *q) { } 251 #endif /* CONFIG_BLK_DEV_THROTTLING */ 252 253 #endif /* BLK_INTERNAL_H */ 254