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