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 #ifdef CONFIG_DEBUG_FS 18 extern struct dentry *blk_debugfs_root; 19 #endif 20 21 struct blk_flush_queue { 22 unsigned int flush_queue_delayed:1; 23 unsigned int flush_pending_idx:1; 24 unsigned int flush_running_idx:1; 25 unsigned long flush_pending_since; 26 struct list_head flush_queue[2]; 27 struct list_head flush_data_in_flight; 28 struct request *flush_rq; 29 30 /* 31 * flush_rq shares tag with this rq, both can't be active 32 * at the same time 33 */ 34 struct request *orig_rq; 35 spinlock_t mq_flush_lock; 36 }; 37 38 extern struct kmem_cache *blk_requestq_cachep; 39 extern struct kmem_cache *request_cachep; 40 extern struct kobj_type blk_queue_ktype; 41 extern struct ida blk_queue_ida; 42 43 static inline struct blk_flush_queue *blk_get_flush_queue( 44 struct request_queue *q, struct blk_mq_ctx *ctx) 45 { 46 if (q->mq_ops) 47 return blk_mq_map_queue(q, ctx->cpu)->fq; 48 return q->fq; 49 } 50 51 static inline void __blk_get_queue(struct request_queue *q) 52 { 53 kobject_get(&q->kobj); 54 } 55 56 struct blk_flush_queue *blk_alloc_flush_queue(struct request_queue *q, 57 int node, int cmd_size); 58 void blk_free_flush_queue(struct blk_flush_queue *q); 59 60 int blk_init_rl(struct request_list *rl, struct request_queue *q, 61 gfp_t gfp_mask); 62 void blk_exit_rl(struct request_queue *q, struct request_list *rl); 63 void blk_rq_bio_prep(struct request_queue *q, struct request *rq, 64 struct bio *bio); 65 void blk_queue_bypass_start(struct request_queue *q); 66 void blk_queue_bypass_end(struct request_queue *q); 67 void blk_dequeue_request(struct request *rq); 68 void __blk_queue_free_tags(struct request_queue *q); 69 void blk_freeze_queue(struct request_queue *q); 70 71 static inline void blk_queue_enter_live(struct request_queue *q) 72 { 73 /* 74 * Given that running in generic_make_request() context 75 * guarantees that a live reference against q_usage_counter has 76 * been established, further references under that same context 77 * need not check that the queue has been frozen (marked dead). 78 */ 79 percpu_ref_get(&q->q_usage_counter); 80 } 81 82 #ifdef CONFIG_BLK_DEV_INTEGRITY 83 void blk_flush_integrity(void); 84 #else 85 static inline void blk_flush_integrity(void) 86 { 87 } 88 #endif 89 90 void blk_timeout_work(struct work_struct *work); 91 unsigned long blk_rq_timeout(unsigned long timeout); 92 void blk_add_timer(struct request *req); 93 void blk_delete_timer(struct request *); 94 95 96 bool bio_attempt_front_merge(struct request_queue *q, struct request *req, 97 struct bio *bio); 98 bool bio_attempt_back_merge(struct request_queue *q, struct request *req, 99 struct bio *bio); 100 bool bio_attempt_discard_merge(struct request_queue *q, struct request *req, 101 struct bio *bio); 102 bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio, 103 unsigned int *request_count, 104 struct request **same_queue_rq); 105 unsigned int blk_plug_queued_count(struct request_queue *q); 106 107 void blk_account_io_start(struct request *req, bool new_io); 108 void blk_account_io_completion(struct request *req, unsigned int bytes); 109 void blk_account_io_done(struct request *req); 110 111 /* 112 * Internal atomic flags for request handling 113 */ 114 enum rq_atomic_flags { 115 REQ_ATOM_COMPLETE = 0, 116 REQ_ATOM_STARTED, 117 REQ_ATOM_POLL_SLEPT, 118 }; 119 120 /* 121 * EH timer and IO completion will both attempt to 'grab' the request, make 122 * sure that only one of them succeeds 123 */ 124 static inline int blk_mark_rq_complete(struct request *rq) 125 { 126 return test_and_set_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags); 127 } 128 129 static inline void blk_clear_rq_complete(struct request *rq) 130 { 131 clear_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags); 132 } 133 134 /* 135 * Internal elevator interface 136 */ 137 #define ELV_ON_HASH(rq) ((rq)->rq_flags & RQF_HASHED) 138 139 void blk_insert_flush(struct request *rq); 140 141 static inline struct request *__elv_next_request(struct request_queue *q) 142 { 143 struct request *rq; 144 struct blk_flush_queue *fq = blk_get_flush_queue(q, NULL); 145 146 while (1) { 147 if (!list_empty(&q->queue_head)) { 148 rq = list_entry_rq(q->queue_head.next); 149 return rq; 150 } 151 152 /* 153 * Flush request is running and flush request isn't queueable 154 * in the drive, we can hold the queue till flush request is 155 * finished. Even we don't do this, driver can't dispatch next 156 * requests and will requeue them. And this can improve 157 * throughput too. For example, we have request flush1, write1, 158 * flush 2. flush1 is dispatched, then queue is hold, write1 159 * isn't inserted to queue. After flush1 is finished, flush2 160 * will be dispatched. Since disk cache is already clean, 161 * flush2 will be finished very soon, so looks like flush2 is 162 * folded to flush1. 163 * Since the queue is hold, a flag is set to indicate the queue 164 * should be restarted later. Please see flush_end_io() for 165 * details. 166 */ 167 if (fq->flush_pending_idx != fq->flush_running_idx && 168 !queue_flush_queueable(q)) { 169 fq->flush_queue_delayed = 1; 170 return NULL; 171 } 172 if (unlikely(blk_queue_bypass(q)) || 173 !q->elevator->type->ops.sq.elevator_dispatch_fn(q, 0)) 174 return NULL; 175 } 176 } 177 178 static inline void elv_activate_rq(struct request_queue *q, struct request *rq) 179 { 180 struct elevator_queue *e = q->elevator; 181 182 if (e->type->ops.sq.elevator_activate_req_fn) 183 e->type->ops.sq.elevator_activate_req_fn(q, rq); 184 } 185 186 static inline void elv_deactivate_rq(struct request_queue *q, struct request *rq) 187 { 188 struct elevator_queue *e = q->elevator; 189 190 if (e->type->ops.sq.elevator_deactivate_req_fn) 191 e->type->ops.sq.elevator_deactivate_req_fn(q, rq); 192 } 193 194 #ifdef CONFIG_FAIL_IO_TIMEOUT 195 int blk_should_fake_timeout(struct request_queue *); 196 ssize_t part_timeout_show(struct device *, struct device_attribute *, char *); 197 ssize_t part_timeout_store(struct device *, struct device_attribute *, 198 const char *, size_t); 199 #else 200 static inline int blk_should_fake_timeout(struct request_queue *q) 201 { 202 return 0; 203 } 204 #endif 205 206 int ll_back_merge_fn(struct request_queue *q, struct request *req, 207 struct bio *bio); 208 int ll_front_merge_fn(struct request_queue *q, struct request *req, 209 struct bio *bio); 210 struct request *attempt_back_merge(struct request_queue *q, struct request *rq); 211 struct request *attempt_front_merge(struct request_queue *q, struct request *rq); 212 int blk_attempt_req_merge(struct request_queue *q, struct request *rq, 213 struct request *next); 214 void blk_recalc_rq_segments(struct request *rq); 215 void blk_rq_set_mixed_merge(struct request *rq); 216 bool blk_rq_merge_ok(struct request *rq, struct bio *bio); 217 enum elv_merge blk_try_merge(struct request *rq, struct bio *bio); 218 219 void blk_queue_congestion_threshold(struct request_queue *q); 220 221 int blk_dev_init(void); 222 223 224 /* 225 * Return the threshold (number of used requests) at which the queue is 226 * considered to be congested. It include a little hysteresis to keep the 227 * context switch rate down. 228 */ 229 static inline int queue_congestion_on_threshold(struct request_queue *q) 230 { 231 return q->nr_congestion_on; 232 } 233 234 /* 235 * The threshold at which a queue is considered to be uncongested 236 */ 237 static inline int queue_congestion_off_threshold(struct request_queue *q) 238 { 239 return q->nr_congestion_off; 240 } 241 242 extern int blk_update_nr_requests(struct request_queue *, unsigned int); 243 244 /* 245 * Contribute to IO statistics IFF: 246 * 247 * a) it's attached to a gendisk, and 248 * b) the queue had IO stats enabled when this request was started, and 249 * c) it's a file system request 250 */ 251 static inline int blk_do_io_stat(struct request *rq) 252 { 253 return rq->rq_disk && 254 (rq->rq_flags & RQF_IO_STAT) && 255 !blk_rq_is_passthrough(rq); 256 } 257 258 static inline void req_set_nomerge(struct request_queue *q, struct request *req) 259 { 260 req->cmd_flags |= REQ_NOMERGE; 261 if (req == q->last_merge) 262 q->last_merge = NULL; 263 } 264 265 /* 266 * Internal io_context interface 267 */ 268 void get_io_context(struct io_context *ioc); 269 struct io_cq *ioc_lookup_icq(struct io_context *ioc, struct request_queue *q); 270 struct io_cq *ioc_create_icq(struct io_context *ioc, struct request_queue *q, 271 gfp_t gfp_mask); 272 void ioc_clear_queue(struct request_queue *q); 273 274 int create_task_io_context(struct task_struct *task, gfp_t gfp_mask, int node); 275 276 /** 277 * rq_ioc - determine io_context for request allocation 278 * @bio: request being allocated is for this bio (can be %NULL) 279 * 280 * Determine io_context to use for request allocation for @bio. May return 281 * %NULL if %current->io_context doesn't exist. 282 */ 283 static inline struct io_context *rq_ioc(struct bio *bio) 284 { 285 #ifdef CONFIG_BLK_CGROUP 286 if (bio && bio->bi_ioc) 287 return bio->bi_ioc; 288 #endif 289 return current->io_context; 290 } 291 292 /** 293 * create_io_context - try to create task->io_context 294 * @gfp_mask: allocation mask 295 * @node: allocation node 296 * 297 * If %current->io_context is %NULL, allocate a new io_context and install 298 * it. Returns the current %current->io_context which may be %NULL if 299 * allocation failed. 300 * 301 * Note that this function can't be called with IRQ disabled because 302 * task_lock which protects %current->io_context is IRQ-unsafe. 303 */ 304 static inline struct io_context *create_io_context(gfp_t gfp_mask, int node) 305 { 306 WARN_ON_ONCE(irqs_disabled()); 307 if (unlikely(!current->io_context)) 308 create_task_io_context(current, gfp_mask, node); 309 return current->io_context; 310 } 311 312 /* 313 * Internal throttling interface 314 */ 315 #ifdef CONFIG_BLK_DEV_THROTTLING 316 extern void blk_throtl_drain(struct request_queue *q); 317 extern int blk_throtl_init(struct request_queue *q); 318 extern void blk_throtl_exit(struct request_queue *q); 319 extern void blk_throtl_register_queue(struct request_queue *q); 320 #else /* CONFIG_BLK_DEV_THROTTLING */ 321 static inline void blk_throtl_drain(struct request_queue *q) { } 322 static inline int blk_throtl_init(struct request_queue *q) { return 0; } 323 static inline void blk_throtl_exit(struct request_queue *q) { } 324 static inline void blk_throtl_register_queue(struct request_queue *q) { } 325 #endif /* CONFIG_BLK_DEV_THROTTLING */ 326 #ifdef CONFIG_BLK_DEV_THROTTLING_LOW 327 extern ssize_t blk_throtl_sample_time_show(struct request_queue *q, char *page); 328 extern ssize_t blk_throtl_sample_time_store(struct request_queue *q, 329 const char *page, size_t count); 330 extern void blk_throtl_bio_endio(struct bio *bio); 331 extern void blk_throtl_stat_add(struct request *rq, u64 time); 332 #else 333 static inline void blk_throtl_bio_endio(struct bio *bio) { } 334 static inline void blk_throtl_stat_add(struct request *rq, u64 time) { } 335 #endif 336 337 #endif /* BLK_INTERNAL_H */ 338