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