1 #ifndef BLK_INTERNAL_H 2 #define BLK_INTERNAL_H 3 4 #include <linux/idr.h> 5 #include <linux/blk-mq.h> 6 #include "blk-mq.h" 7 8 /* Amount of time in which a process may batch requests */ 9 #define BLK_BATCH_TIME (HZ/50UL) 10 11 /* Number of requests a "batching" process may submit */ 12 #define BLK_BATCH_REQ 32 13 14 /* Max future timer expiry for timeouts */ 15 #define BLK_MAX_TIMEOUT (5 * HZ) 16 17 struct blk_flush_queue { 18 unsigned int flush_queue_delayed:1; 19 unsigned int flush_pending_idx:1; 20 unsigned int flush_running_idx:1; 21 unsigned long flush_pending_since; 22 struct list_head flush_queue[2]; 23 struct list_head flush_data_in_flight; 24 struct request *flush_rq; 25 26 /* 27 * flush_rq shares tag with this rq, both can't be active 28 * at the same time 29 */ 30 struct request *orig_rq; 31 spinlock_t mq_flush_lock; 32 }; 33 34 extern struct kmem_cache *blk_requestq_cachep; 35 extern struct kmem_cache *request_cachep; 36 extern struct kobj_type blk_queue_ktype; 37 extern struct ida blk_queue_ida; 38 39 static inline struct blk_flush_queue *blk_get_flush_queue( 40 struct request_queue *q, struct blk_mq_ctx *ctx) 41 { 42 if (q->mq_ops) 43 return blk_mq_map_queue(q, ctx->cpu)->fq; 44 return q->fq; 45 } 46 47 static inline void __blk_get_queue(struct request_queue *q) 48 { 49 kobject_get(&q->kobj); 50 } 51 52 struct blk_flush_queue *blk_alloc_flush_queue(struct request_queue *q, 53 int node, int cmd_size); 54 void blk_free_flush_queue(struct blk_flush_queue *q); 55 56 int blk_init_rl(struct request_list *rl, struct request_queue *q, 57 gfp_t gfp_mask); 58 void blk_exit_rl(struct request_list *rl); 59 void init_request_from_bio(struct request *req, struct bio *bio); 60 void blk_rq_bio_prep(struct request_queue *q, struct request *rq, 61 struct bio *bio); 62 void blk_queue_bypass_start(struct request_queue *q); 63 void blk_queue_bypass_end(struct request_queue *q); 64 void blk_dequeue_request(struct request *rq); 65 void __blk_queue_free_tags(struct request_queue *q); 66 bool __blk_end_bidi_request(struct request *rq, int error, 67 unsigned int nr_bytes, unsigned int bidi_bytes); 68 void blk_freeze_queue(struct request_queue *q); 69 70 static inline void blk_queue_enter_live(struct request_queue *q) 71 { 72 /* 73 * Given that running in generic_make_request() context 74 * guarantees that a live reference against q_usage_counter has 75 * been established, further references under that same context 76 * need not check that the queue has been frozen (marked dead). 77 */ 78 percpu_ref_get(&q->q_usage_counter); 79 } 80 81 #ifdef CONFIG_BLK_DEV_INTEGRITY 82 void blk_flush_integrity(void); 83 #else 84 static inline void blk_flush_integrity(void) 85 { 86 } 87 #endif 88 89 void blk_timeout_work(struct work_struct *work); 90 unsigned long blk_rq_timeout(unsigned long timeout); 91 void blk_add_timer(struct request *req); 92 void blk_delete_timer(struct request *); 93 94 95 bool bio_attempt_front_merge(struct request_queue *q, struct request *req, 96 struct bio *bio); 97 bool bio_attempt_back_merge(struct request_queue *q, struct request *req, 98 struct bio *bio); 99 bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio, 100 unsigned int *request_count, 101 struct request **same_queue_rq); 102 unsigned int blk_plug_queued_count(struct request_queue *q); 103 104 void blk_account_io_start(struct request *req, bool new_io); 105 void blk_account_io_completion(struct request *req, unsigned int bytes); 106 void blk_account_io_done(struct request *req); 107 108 /* 109 * Internal atomic flags for request handling 110 */ 111 enum rq_atomic_flags { 112 REQ_ATOM_COMPLETE = 0, 113 REQ_ATOM_STARTED, 114 REQ_ATOM_POLL_SLEPT, 115 }; 116 117 /* 118 * EH timer and IO completion will both attempt to 'grab' the request, make 119 * sure that only one of them succeeds 120 */ 121 static inline int blk_mark_rq_complete(struct request *rq) 122 { 123 return test_and_set_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags); 124 } 125 126 static inline void blk_clear_rq_complete(struct request *rq) 127 { 128 clear_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags); 129 } 130 131 /* 132 * Internal elevator interface 133 */ 134 #define ELV_ON_HASH(rq) ((rq)->rq_flags & RQF_HASHED) 135 136 void blk_insert_flush(struct request *rq); 137 138 static inline struct request *__elv_next_request(struct request_queue *q) 139 { 140 struct request *rq; 141 struct blk_flush_queue *fq = blk_get_flush_queue(q, NULL); 142 143 while (1) { 144 if (!list_empty(&q->queue_head)) { 145 rq = list_entry_rq(q->queue_head.next); 146 return rq; 147 } 148 149 /* 150 * Flush request is running and flush request isn't queueable 151 * in the drive, we can hold the queue till flush request is 152 * finished. Even we don't do this, driver can't dispatch next 153 * requests and will requeue them. And this can improve 154 * throughput too. For example, we have request flush1, write1, 155 * flush 2. flush1 is dispatched, then queue is hold, write1 156 * isn't inserted to queue. After flush1 is finished, flush2 157 * will be dispatched. Since disk cache is already clean, 158 * flush2 will be finished very soon, so looks like flush2 is 159 * folded to flush1. 160 * Since the queue is hold, a flag is set to indicate the queue 161 * should be restarted later. Please see flush_end_io() for 162 * details. 163 */ 164 if (fq->flush_pending_idx != fq->flush_running_idx && 165 !queue_flush_queueable(q)) { 166 fq->flush_queue_delayed = 1; 167 return NULL; 168 } 169 if (unlikely(blk_queue_bypass(q)) || 170 !q->elevator->type->ops.elevator_dispatch_fn(q, 0)) 171 return NULL; 172 } 173 } 174 175 static inline void elv_activate_rq(struct request_queue *q, struct request *rq) 176 { 177 struct elevator_queue *e = q->elevator; 178 179 if (e->type->ops.elevator_activate_req_fn) 180 e->type->ops.elevator_activate_req_fn(q, rq); 181 } 182 183 static inline void elv_deactivate_rq(struct request_queue *q, struct request *rq) 184 { 185 struct elevator_queue *e = q->elevator; 186 187 if (e->type->ops.elevator_deactivate_req_fn) 188 e->type->ops.elevator_deactivate_req_fn(q, rq); 189 } 190 191 #ifdef CONFIG_FAIL_IO_TIMEOUT 192 int blk_should_fake_timeout(struct request_queue *); 193 ssize_t part_timeout_show(struct device *, struct device_attribute *, char *); 194 ssize_t part_timeout_store(struct device *, struct device_attribute *, 195 const char *, size_t); 196 #else 197 static inline int blk_should_fake_timeout(struct request_queue *q) 198 { 199 return 0; 200 } 201 #endif 202 203 int ll_back_merge_fn(struct request_queue *q, struct request *req, 204 struct bio *bio); 205 int ll_front_merge_fn(struct request_queue *q, struct request *req, 206 struct bio *bio); 207 int attempt_back_merge(struct request_queue *q, struct request *rq); 208 int attempt_front_merge(struct request_queue *q, struct request *rq); 209 int blk_attempt_req_merge(struct request_queue *q, struct request *rq, 210 struct request *next); 211 void blk_recalc_rq_segments(struct request *rq); 212 void blk_rq_set_mixed_merge(struct request *rq); 213 bool blk_rq_merge_ok(struct request *rq, struct bio *bio); 214 int blk_try_merge(struct request *rq, struct bio *bio); 215 216 void blk_queue_congestion_threshold(struct request_queue *q); 217 218 int blk_dev_init(void); 219 220 221 /* 222 * Return the threshold (number of used requests) at which the queue is 223 * considered to be congested. It include a little hysteresis to keep the 224 * context switch rate down. 225 */ 226 static inline int queue_congestion_on_threshold(struct request_queue *q) 227 { 228 return q->nr_congestion_on; 229 } 230 231 /* 232 * The threshold at which a queue is considered to be uncongested 233 */ 234 static inline int queue_congestion_off_threshold(struct request_queue *q) 235 { 236 return q->nr_congestion_off; 237 } 238 239 extern int blk_update_nr_requests(struct request_queue *, unsigned int); 240 241 /* 242 * Contribute to IO statistics IFF: 243 * 244 * a) it's attached to a gendisk, and 245 * b) the queue had IO stats enabled when this request was started, and 246 * c) it's a file system request 247 */ 248 static inline int blk_do_io_stat(struct request *rq) 249 { 250 return rq->rq_disk && 251 (rq->rq_flags & RQF_IO_STAT) && 252 (rq->cmd_type == REQ_TYPE_FS); 253 } 254 255 /* 256 * Internal io_context interface 257 */ 258 void get_io_context(struct io_context *ioc); 259 struct io_cq *ioc_lookup_icq(struct io_context *ioc, struct request_queue *q); 260 struct io_cq *ioc_create_icq(struct io_context *ioc, struct request_queue *q, 261 gfp_t gfp_mask); 262 void ioc_clear_queue(struct request_queue *q); 263 264 int create_task_io_context(struct task_struct *task, gfp_t gfp_mask, int node); 265 266 /** 267 * create_io_context - try to create task->io_context 268 * @gfp_mask: allocation mask 269 * @node: allocation node 270 * 271 * If %current->io_context is %NULL, allocate a new io_context and install 272 * it. Returns the current %current->io_context which may be %NULL if 273 * allocation failed. 274 * 275 * Note that this function can't be called with IRQ disabled because 276 * task_lock which protects %current->io_context is IRQ-unsafe. 277 */ 278 static inline struct io_context *create_io_context(gfp_t gfp_mask, int node) 279 { 280 WARN_ON_ONCE(irqs_disabled()); 281 if (unlikely(!current->io_context)) 282 create_task_io_context(current, gfp_mask, node); 283 return current->io_context; 284 } 285 286 /* 287 * Internal throttling interface 288 */ 289 #ifdef CONFIG_BLK_DEV_THROTTLING 290 extern void blk_throtl_drain(struct request_queue *q); 291 extern int blk_throtl_init(struct request_queue *q); 292 extern void blk_throtl_exit(struct request_queue *q); 293 #else /* CONFIG_BLK_DEV_THROTTLING */ 294 static inline void blk_throtl_drain(struct request_queue *q) { } 295 static inline int blk_throtl_init(struct request_queue *q) { return 0; } 296 static inline void blk_throtl_exit(struct request_queue *q) { } 297 #endif /* CONFIG_BLK_DEV_THROTTLING */ 298 299 #endif /* BLK_INTERNAL_H */ 300