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 struct blk_mq_hw_ctx *hctx; 43 44 if (!q->mq_ops) 45 return q->fq; 46 47 hctx = q->mq_ops->map_queue(q, ctx->cpu); 48 49 return hctx->fq; 50 } 51 52 static inline void __blk_get_queue(struct request_queue *q) 53 { 54 kobject_get(&q->kobj); 55 } 56 57 struct blk_flush_queue *blk_alloc_flush_queue(struct request_queue *q, 58 int node, int cmd_size); 59 void blk_free_flush_queue(struct blk_flush_queue *q); 60 61 int blk_init_rl(struct request_list *rl, struct request_queue *q, 62 gfp_t gfp_mask); 63 void blk_exit_rl(struct request_list *rl); 64 void init_request_from_bio(struct request *req, struct bio *bio); 65 void blk_rq_bio_prep(struct request_queue *q, struct request *rq, 66 struct bio *bio); 67 int blk_rq_append_bio(struct request_queue *q, struct request *rq, 68 struct bio *bio); 69 void blk_queue_bypass_start(struct request_queue *q); 70 void blk_queue_bypass_end(struct request_queue *q); 71 void blk_dequeue_request(struct request *rq); 72 void __blk_queue_free_tags(struct request_queue *q); 73 bool __blk_end_bidi_request(struct request *rq, int error, 74 unsigned int nr_bytes, unsigned int bidi_bytes); 75 void blk_freeze_queue(struct request_queue *q); 76 77 static inline void blk_queue_enter_live(struct request_queue *q) 78 { 79 /* 80 * Given that running in generic_make_request() context 81 * guarantees that a live reference against q_usage_counter has 82 * been established, further references under that same context 83 * need not check that the queue has been frozen (marked dead). 84 */ 85 percpu_ref_get(&q->q_usage_counter); 86 } 87 88 #ifdef CONFIG_BLK_DEV_INTEGRITY 89 void blk_flush_integrity(void); 90 #else 91 static inline void blk_flush_integrity(void) 92 { 93 } 94 #endif 95 96 void blk_timeout_work(struct work_struct *work); 97 unsigned long blk_rq_timeout(unsigned long timeout); 98 void blk_add_timer(struct request *req); 99 void blk_delete_timer(struct request *); 100 101 102 bool bio_attempt_front_merge(struct request_queue *q, struct request *req, 103 struct bio *bio); 104 bool bio_attempt_back_merge(struct request_queue *q, struct request *req, 105 struct bio *bio); 106 bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio, 107 unsigned int *request_count, 108 struct request **same_queue_rq); 109 unsigned int blk_plug_queued_count(struct request_queue *q); 110 111 void blk_account_io_start(struct request *req, bool new_io); 112 void blk_account_io_completion(struct request *req, unsigned int bytes); 113 void blk_account_io_done(struct request *req); 114 115 /* 116 * Internal atomic flags for request handling 117 */ 118 enum rq_atomic_flags { 119 REQ_ATOM_COMPLETE = 0, 120 REQ_ATOM_STARTED, 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)->cmd_flags & REQ_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.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.elevator_activate_req_fn) 186 e->type->ops.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.elevator_deactivate_req_fn) 194 e->type->ops.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 int attempt_back_merge(struct request_queue *q, struct request *rq); 214 int 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 int 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->cmd_flags & REQ_IO_STAT) && 258 (rq->cmd_type == REQ_TYPE_FS); 259 } 260 261 /* 262 * Internal io_context interface 263 */ 264 void get_io_context(struct io_context *ioc); 265 struct io_cq *ioc_lookup_icq(struct io_context *ioc, struct request_queue *q); 266 struct io_cq *ioc_create_icq(struct io_context *ioc, struct request_queue *q, 267 gfp_t gfp_mask); 268 void ioc_clear_queue(struct request_queue *q); 269 270 int create_task_io_context(struct task_struct *task, gfp_t gfp_mask, int node); 271 272 /** 273 * create_io_context - try to create task->io_context 274 * @gfp_mask: allocation mask 275 * @node: allocation node 276 * 277 * If %current->io_context is %NULL, allocate a new io_context and install 278 * it. Returns the current %current->io_context which may be %NULL if 279 * allocation failed. 280 * 281 * Note that this function can't be called with IRQ disabled because 282 * task_lock which protects %current->io_context is IRQ-unsafe. 283 */ 284 static inline struct io_context *create_io_context(gfp_t gfp_mask, int node) 285 { 286 WARN_ON_ONCE(irqs_disabled()); 287 if (unlikely(!current->io_context)) 288 create_task_io_context(current, gfp_mask, node); 289 return current->io_context; 290 } 291 292 /* 293 * Internal throttling interface 294 */ 295 #ifdef CONFIG_BLK_DEV_THROTTLING 296 extern void blk_throtl_drain(struct request_queue *q); 297 extern int blk_throtl_init(struct request_queue *q); 298 extern void blk_throtl_exit(struct request_queue *q); 299 #else /* CONFIG_BLK_DEV_THROTTLING */ 300 static inline void blk_throtl_drain(struct request_queue *q) { } 301 static inline int blk_throtl_init(struct request_queue *q) { return 0; } 302 static inline void blk_throtl_exit(struct request_queue *q) { } 303 #endif /* CONFIG_BLK_DEV_THROTTLING */ 304 305 #endif /* BLK_INTERNAL_H */ 306