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 }; 115 116 /* 117 * EH timer and IO completion will both attempt to 'grab' the request, make 118 * sure that only one of them succeeds 119 */ 120 static inline int blk_mark_rq_complete(struct request *rq) 121 { 122 return test_and_set_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags); 123 } 124 125 static inline void blk_clear_rq_complete(struct request *rq) 126 { 127 clear_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags); 128 } 129 130 /* 131 * Internal elevator interface 132 */ 133 #define ELV_ON_HASH(rq) ((rq)->cmd_flags & REQ_HASHED) 134 135 void blk_insert_flush(struct request *rq); 136 137 static inline struct request *__elv_next_request(struct request_queue *q) 138 { 139 struct request *rq; 140 struct blk_flush_queue *fq = blk_get_flush_queue(q, NULL); 141 142 while (1) { 143 if (!list_empty(&q->queue_head)) { 144 rq = list_entry_rq(q->queue_head.next); 145 return rq; 146 } 147 148 /* 149 * Flush request is running and flush request isn't queueable 150 * in the drive, we can hold the queue till flush request is 151 * finished. Even we don't do this, driver can't dispatch next 152 * requests and will requeue them. And this can improve 153 * throughput too. For example, we have request flush1, write1, 154 * flush 2. flush1 is dispatched, then queue is hold, write1 155 * isn't inserted to queue. After flush1 is finished, flush2 156 * will be dispatched. Since disk cache is already clean, 157 * flush2 will be finished very soon, so looks like flush2 is 158 * folded to flush1. 159 * Since the queue is hold, a flag is set to indicate the queue 160 * should be restarted later. Please see flush_end_io() for 161 * details. 162 */ 163 if (fq->flush_pending_idx != fq->flush_running_idx && 164 !queue_flush_queueable(q)) { 165 fq->flush_queue_delayed = 1; 166 return NULL; 167 } 168 if (unlikely(blk_queue_bypass(q)) || 169 !q->elevator->type->ops.elevator_dispatch_fn(q, 0)) 170 return NULL; 171 } 172 } 173 174 static inline void elv_activate_rq(struct request_queue *q, struct request *rq) 175 { 176 struct elevator_queue *e = q->elevator; 177 178 if (e->type->ops.elevator_activate_req_fn) 179 e->type->ops.elevator_activate_req_fn(q, rq); 180 } 181 182 static inline void elv_deactivate_rq(struct request_queue *q, struct request *rq) 183 { 184 struct elevator_queue *e = q->elevator; 185 186 if (e->type->ops.elevator_deactivate_req_fn) 187 e->type->ops.elevator_deactivate_req_fn(q, rq); 188 } 189 190 #ifdef CONFIG_FAIL_IO_TIMEOUT 191 int blk_should_fake_timeout(struct request_queue *); 192 ssize_t part_timeout_show(struct device *, struct device_attribute *, char *); 193 ssize_t part_timeout_store(struct device *, struct device_attribute *, 194 const char *, size_t); 195 #else 196 static inline int blk_should_fake_timeout(struct request_queue *q) 197 { 198 return 0; 199 } 200 #endif 201 202 int ll_back_merge_fn(struct request_queue *q, struct request *req, 203 struct bio *bio); 204 int ll_front_merge_fn(struct request_queue *q, struct request *req, 205 struct bio *bio); 206 int attempt_back_merge(struct request_queue *q, struct request *rq); 207 int attempt_front_merge(struct request_queue *q, struct request *rq); 208 int blk_attempt_req_merge(struct request_queue *q, struct request *rq, 209 struct request *next); 210 void blk_recalc_rq_segments(struct request *rq); 211 void blk_rq_set_mixed_merge(struct request *rq); 212 bool blk_rq_merge_ok(struct request *rq, struct bio *bio); 213 int blk_try_merge(struct request *rq, struct bio *bio); 214 215 void blk_queue_congestion_threshold(struct request_queue *q); 216 217 int blk_dev_init(void); 218 219 220 /* 221 * Return the threshold (number of used requests) at which the queue is 222 * considered to be congested. It include a little hysteresis to keep the 223 * context switch rate down. 224 */ 225 static inline int queue_congestion_on_threshold(struct request_queue *q) 226 { 227 return q->nr_congestion_on; 228 } 229 230 /* 231 * The threshold at which a queue is considered to be uncongested 232 */ 233 static inline int queue_congestion_off_threshold(struct request_queue *q) 234 { 235 return q->nr_congestion_off; 236 } 237 238 extern int blk_update_nr_requests(struct request_queue *, unsigned int); 239 240 /* 241 * Contribute to IO statistics IFF: 242 * 243 * a) it's attached to a gendisk, and 244 * b) the queue had IO stats enabled when this request was started, and 245 * c) it's a file system request 246 */ 247 static inline int blk_do_io_stat(struct request *rq) 248 { 249 return rq->rq_disk && 250 (rq->cmd_flags & REQ_IO_STAT) && 251 (rq->cmd_type == REQ_TYPE_FS); 252 } 253 254 /* 255 * Internal io_context interface 256 */ 257 void get_io_context(struct io_context *ioc); 258 struct io_cq *ioc_lookup_icq(struct io_context *ioc, struct request_queue *q); 259 struct io_cq *ioc_create_icq(struct io_context *ioc, struct request_queue *q, 260 gfp_t gfp_mask); 261 void ioc_clear_queue(struct request_queue *q); 262 263 int create_task_io_context(struct task_struct *task, gfp_t gfp_mask, int node); 264 265 /** 266 * create_io_context - try to create task->io_context 267 * @gfp_mask: allocation mask 268 * @node: allocation node 269 * 270 * If %current->io_context is %NULL, allocate a new io_context and install 271 * it. Returns the current %current->io_context which may be %NULL if 272 * allocation failed. 273 * 274 * Note that this function can't be called with IRQ disabled because 275 * task_lock which protects %current->io_context is IRQ-unsafe. 276 */ 277 static inline struct io_context *create_io_context(gfp_t gfp_mask, int node) 278 { 279 WARN_ON_ONCE(irqs_disabled()); 280 if (unlikely(!current->io_context)) 281 create_task_io_context(current, gfp_mask, node); 282 return current->io_context; 283 } 284 285 /* 286 * Internal throttling interface 287 */ 288 #ifdef CONFIG_BLK_DEV_THROTTLING 289 extern void blk_throtl_drain(struct request_queue *q); 290 extern int blk_throtl_init(struct request_queue *q); 291 extern void blk_throtl_exit(struct request_queue *q); 292 #else /* CONFIG_BLK_DEV_THROTTLING */ 293 static inline void blk_throtl_drain(struct request_queue *q) { } 294 static inline int blk_throtl_init(struct request_queue *q) { return 0; } 295 static inline void blk_throtl_exit(struct request_queue *q) { } 296 #endif /* CONFIG_BLK_DEV_THROTTLING */ 297 298 #endif /* BLK_INTERNAL_H */ 299