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