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