1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef BLK_INTERNAL_H 3 #define BLK_INTERNAL_H 4 5 #include <linux/idr.h> 6 #include <linux/blk-mq.h> 7 #include "blk-mq.h" 8 9 /* Amount of time in which a process may batch requests */ 10 #define BLK_BATCH_TIME (HZ/50UL) 11 12 /* Number of requests a "batching" process may submit */ 13 #define BLK_BATCH_REQ 32 14 15 /* Max future timer expiry for timeouts */ 16 #define BLK_MAX_TIMEOUT (5 * HZ) 17 18 #ifdef CONFIG_DEBUG_FS 19 extern struct dentry *blk_debugfs_root; 20 #endif 21 22 struct blk_flush_queue { 23 unsigned int flush_queue_delayed:1; 24 unsigned int flush_pending_idx:1; 25 unsigned int flush_running_idx:1; 26 unsigned long flush_pending_since; 27 struct list_head flush_queue[2]; 28 struct list_head flush_data_in_flight; 29 struct request *flush_rq; 30 31 /* 32 * flush_rq shares tag with this rq, both can't be active 33 * at the same time 34 */ 35 struct request *orig_rq; 36 spinlock_t mq_flush_lock; 37 }; 38 39 extern struct kmem_cache *blk_requestq_cachep; 40 extern struct kmem_cache *request_cachep; 41 extern struct kobj_type blk_queue_ktype; 42 extern struct ida blk_queue_ida; 43 44 /* 45 * @q->queue_lock is set while a queue is being initialized. Since we know 46 * that no other threads access the queue object before @q->queue_lock has 47 * been set, it is safe to manipulate queue flags without holding the 48 * queue_lock if @q->queue_lock == NULL. See also blk_alloc_queue_node() and 49 * blk_init_allocated_queue(). 50 */ 51 static inline void queue_lockdep_assert_held(struct request_queue *q) 52 { 53 if (q->queue_lock) 54 lockdep_assert_held(q->queue_lock); 55 } 56 57 static inline void queue_flag_set_unlocked(unsigned int flag, 58 struct request_queue *q) 59 { 60 if (test_bit(QUEUE_FLAG_INIT_DONE, &q->queue_flags) && 61 kref_read(&q->kobj.kref)) 62 lockdep_assert_held(q->queue_lock); 63 __set_bit(flag, &q->queue_flags); 64 } 65 66 static inline void queue_flag_clear_unlocked(unsigned int flag, 67 struct request_queue *q) 68 { 69 if (test_bit(QUEUE_FLAG_INIT_DONE, &q->queue_flags) && 70 kref_read(&q->kobj.kref)) 71 lockdep_assert_held(q->queue_lock); 72 __clear_bit(flag, &q->queue_flags); 73 } 74 75 static inline int queue_flag_test_and_clear(unsigned int flag, 76 struct request_queue *q) 77 { 78 queue_lockdep_assert_held(q); 79 80 if (test_bit(flag, &q->queue_flags)) { 81 __clear_bit(flag, &q->queue_flags); 82 return 1; 83 } 84 85 return 0; 86 } 87 88 static inline int queue_flag_test_and_set(unsigned int flag, 89 struct request_queue *q) 90 { 91 queue_lockdep_assert_held(q); 92 93 if (!test_bit(flag, &q->queue_flags)) { 94 __set_bit(flag, &q->queue_flags); 95 return 0; 96 } 97 98 return 1; 99 } 100 101 static inline void queue_flag_set(unsigned int flag, struct request_queue *q) 102 { 103 queue_lockdep_assert_held(q); 104 __set_bit(flag, &q->queue_flags); 105 } 106 107 static inline void queue_flag_clear(unsigned int flag, struct request_queue *q) 108 { 109 queue_lockdep_assert_held(q); 110 __clear_bit(flag, &q->queue_flags); 111 } 112 113 static inline struct blk_flush_queue *blk_get_flush_queue( 114 struct request_queue *q, struct blk_mq_ctx *ctx) 115 { 116 if (q->mq_ops) 117 return blk_mq_map_queue(q, ctx->cpu)->fq; 118 return q->fq; 119 } 120 121 static inline void __blk_get_queue(struct request_queue *q) 122 { 123 kobject_get(&q->kobj); 124 } 125 126 struct blk_flush_queue *blk_alloc_flush_queue(struct request_queue *q, 127 int node, int cmd_size); 128 void blk_free_flush_queue(struct blk_flush_queue *q); 129 130 int blk_init_rl(struct request_list *rl, struct request_queue *q, 131 gfp_t gfp_mask); 132 void blk_exit_rl(struct request_queue *q, struct request_list *rl); 133 void blk_exit_queue(struct request_queue *q); 134 void blk_rq_bio_prep(struct request_queue *q, struct request *rq, 135 struct bio *bio); 136 void blk_queue_bypass_start(struct request_queue *q); 137 void blk_queue_bypass_end(struct request_queue *q); 138 void __blk_queue_free_tags(struct request_queue *q); 139 void blk_freeze_queue(struct request_queue *q); 140 141 static inline void blk_queue_enter_live(struct request_queue *q) 142 { 143 /* 144 * Given that running in generic_make_request() context 145 * guarantees that a live reference against q_usage_counter has 146 * been established, further references under that same context 147 * need not check that the queue has been frozen (marked dead). 148 */ 149 percpu_ref_get(&q->q_usage_counter); 150 } 151 152 #ifdef CONFIG_BLK_DEV_INTEGRITY 153 void blk_flush_integrity(void); 154 bool __bio_integrity_endio(struct bio *); 155 static inline bool bio_integrity_endio(struct bio *bio) 156 { 157 if (bio_integrity(bio)) 158 return __bio_integrity_endio(bio); 159 return true; 160 } 161 #else 162 static inline void blk_flush_integrity(void) 163 { 164 } 165 static inline bool bio_integrity_endio(struct bio *bio) 166 { 167 return true; 168 } 169 #endif 170 171 void blk_timeout_work(struct work_struct *work); 172 unsigned long blk_rq_timeout(unsigned long timeout); 173 void blk_add_timer(struct request *req); 174 void blk_delete_timer(struct request *); 175 176 177 bool bio_attempt_front_merge(struct request_queue *q, struct request *req, 178 struct bio *bio); 179 bool bio_attempt_back_merge(struct request_queue *q, struct request *req, 180 struct bio *bio); 181 bool bio_attempt_discard_merge(struct request_queue *q, struct request *req, 182 struct bio *bio); 183 bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio, 184 unsigned int *request_count, 185 struct request **same_queue_rq); 186 unsigned int blk_plug_queued_count(struct request_queue *q); 187 188 void blk_account_io_start(struct request *req, bool new_io); 189 void blk_account_io_completion(struct request *req, unsigned int bytes); 190 void blk_account_io_done(struct request *req, u64 now); 191 192 /* 193 * EH timer and IO completion will both attempt to 'grab' the request, make 194 * sure that only one of them succeeds. Steal the bottom bit of the 195 * __deadline field for this. 196 */ 197 static inline int blk_mark_rq_complete(struct request *rq) 198 { 199 return test_and_set_bit(0, &rq->__deadline); 200 } 201 202 static inline void blk_clear_rq_complete(struct request *rq) 203 { 204 clear_bit(0, &rq->__deadline); 205 } 206 207 static inline bool blk_rq_is_complete(struct request *rq) 208 { 209 return test_bit(0, &rq->__deadline); 210 } 211 212 /* 213 * Internal elevator interface 214 */ 215 #define ELV_ON_HASH(rq) ((rq)->rq_flags & RQF_HASHED) 216 217 void blk_insert_flush(struct request *rq); 218 219 static inline void elv_activate_rq(struct request_queue *q, struct request *rq) 220 { 221 struct elevator_queue *e = q->elevator; 222 223 if (e->type->ops.sq.elevator_activate_req_fn) 224 e->type->ops.sq.elevator_activate_req_fn(q, rq); 225 } 226 227 static inline void elv_deactivate_rq(struct request_queue *q, struct request *rq) 228 { 229 struct elevator_queue *e = q->elevator; 230 231 if (e->type->ops.sq.elevator_deactivate_req_fn) 232 e->type->ops.sq.elevator_deactivate_req_fn(q, rq); 233 } 234 235 int elevator_init(struct request_queue *); 236 int elevator_init_mq(struct request_queue *q); 237 int elevator_switch_mq(struct request_queue *q, 238 struct elevator_type *new_e); 239 void elevator_exit(struct request_queue *, struct elevator_queue *); 240 int elv_register_queue(struct request_queue *q); 241 void elv_unregister_queue(struct request_queue *q); 242 243 struct hd_struct *__disk_get_part(struct gendisk *disk, int partno); 244 245 #ifdef CONFIG_FAIL_IO_TIMEOUT 246 int blk_should_fake_timeout(struct request_queue *); 247 ssize_t part_timeout_show(struct device *, struct device_attribute *, char *); 248 ssize_t part_timeout_store(struct device *, struct device_attribute *, 249 const char *, size_t); 250 #else 251 static inline int blk_should_fake_timeout(struct request_queue *q) 252 { 253 return 0; 254 } 255 #endif 256 257 int ll_back_merge_fn(struct request_queue *q, struct request *req, 258 struct bio *bio); 259 int ll_front_merge_fn(struct request_queue *q, struct request *req, 260 struct bio *bio); 261 struct request *attempt_back_merge(struct request_queue *q, struct request *rq); 262 struct request *attempt_front_merge(struct request_queue *q, struct request *rq); 263 int blk_attempt_req_merge(struct request_queue *q, struct request *rq, 264 struct request *next); 265 void blk_recalc_rq_segments(struct request *rq); 266 void blk_rq_set_mixed_merge(struct request *rq); 267 bool blk_rq_merge_ok(struct request *rq, struct bio *bio); 268 enum elv_merge blk_try_merge(struct request *rq, struct bio *bio); 269 270 void blk_queue_congestion_threshold(struct request_queue *q); 271 272 int blk_dev_init(void); 273 274 275 /* 276 * Return the threshold (number of used requests) at which the queue is 277 * considered to be congested. It include a little hysteresis to keep the 278 * context switch rate down. 279 */ 280 static inline int queue_congestion_on_threshold(struct request_queue *q) 281 { 282 return q->nr_congestion_on; 283 } 284 285 /* 286 * The threshold at which a queue is considered to be uncongested 287 */ 288 static inline int queue_congestion_off_threshold(struct request_queue *q) 289 { 290 return q->nr_congestion_off; 291 } 292 293 extern int blk_update_nr_requests(struct request_queue *, unsigned int); 294 295 /* 296 * Contribute to IO statistics IFF: 297 * 298 * a) it's attached to a gendisk, and 299 * b) the queue had IO stats enabled when this request was started, and 300 * c) it's a file system request 301 */ 302 static inline bool blk_do_io_stat(struct request *rq) 303 { 304 return rq->rq_disk && 305 (rq->rq_flags & RQF_IO_STAT) && 306 !blk_rq_is_passthrough(rq); 307 } 308 309 static inline void req_set_nomerge(struct request_queue *q, struct request *req) 310 { 311 req->cmd_flags |= REQ_NOMERGE; 312 if (req == q->last_merge) 313 q->last_merge = NULL; 314 } 315 316 /* 317 * Steal a bit from this field for legacy IO path atomic IO marking. Note that 318 * setting the deadline clears the bottom bit, potentially clearing the 319 * completed bit. The user has to be OK with this (current ones are fine). 320 */ 321 static inline void blk_rq_set_deadline(struct request *rq, unsigned long time) 322 { 323 rq->__deadline = time & ~0x1UL; 324 } 325 326 static inline unsigned long blk_rq_deadline(struct request *rq) 327 { 328 return rq->__deadline & ~0x1UL; 329 } 330 331 /* 332 * Internal io_context interface 333 */ 334 void get_io_context(struct io_context *ioc); 335 struct io_cq *ioc_lookup_icq(struct io_context *ioc, struct request_queue *q); 336 struct io_cq *ioc_create_icq(struct io_context *ioc, struct request_queue *q, 337 gfp_t gfp_mask); 338 void ioc_clear_queue(struct request_queue *q); 339 340 int create_task_io_context(struct task_struct *task, gfp_t gfp_mask, int node); 341 342 /** 343 * rq_ioc - determine io_context for request allocation 344 * @bio: request being allocated is for this bio (can be %NULL) 345 * 346 * Determine io_context to use for request allocation for @bio. May return 347 * %NULL if %current->io_context doesn't exist. 348 */ 349 static inline struct io_context *rq_ioc(struct bio *bio) 350 { 351 #ifdef CONFIG_BLK_CGROUP 352 if (bio && bio->bi_ioc) 353 return bio->bi_ioc; 354 #endif 355 return current->io_context; 356 } 357 358 /** 359 * create_io_context - try to create task->io_context 360 * @gfp_mask: allocation mask 361 * @node: allocation node 362 * 363 * If %current->io_context is %NULL, allocate a new io_context and install 364 * it. Returns the current %current->io_context which may be %NULL if 365 * allocation failed. 366 * 367 * Note that this function can't be called with IRQ disabled because 368 * task_lock which protects %current->io_context is IRQ-unsafe. 369 */ 370 static inline struct io_context *create_io_context(gfp_t gfp_mask, int node) 371 { 372 WARN_ON_ONCE(irqs_disabled()); 373 if (unlikely(!current->io_context)) 374 create_task_io_context(current, gfp_mask, node); 375 return current->io_context; 376 } 377 378 /* 379 * Internal throttling interface 380 */ 381 #ifdef CONFIG_BLK_DEV_THROTTLING 382 extern void blk_throtl_drain(struct request_queue *q); 383 extern int blk_throtl_init(struct request_queue *q); 384 extern void blk_throtl_exit(struct request_queue *q); 385 extern void blk_throtl_register_queue(struct request_queue *q); 386 #else /* CONFIG_BLK_DEV_THROTTLING */ 387 static inline void blk_throtl_drain(struct request_queue *q) { } 388 static inline int blk_throtl_init(struct request_queue *q) { return 0; } 389 static inline void blk_throtl_exit(struct request_queue *q) { } 390 static inline void blk_throtl_register_queue(struct request_queue *q) { } 391 #endif /* CONFIG_BLK_DEV_THROTTLING */ 392 #ifdef CONFIG_BLK_DEV_THROTTLING_LOW 393 extern ssize_t blk_throtl_sample_time_show(struct request_queue *q, char *page); 394 extern ssize_t blk_throtl_sample_time_store(struct request_queue *q, 395 const char *page, size_t count); 396 extern void blk_throtl_bio_endio(struct bio *bio); 397 extern void blk_throtl_stat_add(struct request *rq, u64 time); 398 #else 399 static inline void blk_throtl_bio_endio(struct bio *bio) { } 400 static inline void blk_throtl_stat_add(struct request *rq, u64 time) { } 401 #endif 402 403 #ifdef CONFIG_BOUNCE 404 extern int init_emergency_isa_pool(void); 405 extern void blk_queue_bounce(struct request_queue *q, struct bio **bio); 406 #else 407 static inline int init_emergency_isa_pool(void) 408 { 409 return 0; 410 } 411 static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio) 412 { 413 } 414 #endif /* CONFIG_BOUNCE */ 415 416 extern void blk_drain_queue(struct request_queue *q); 417 418 #ifdef CONFIG_BLK_CGROUP_IOLATENCY 419 extern int blk_iolatency_init(struct request_queue *q); 420 #else 421 static inline int blk_iolatency_init(struct request_queue *q) { return 0; } 422 #endif 423 424 #endif /* BLK_INTERNAL_H */ 425