block/blk.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef BLK_INTERNAL_H
   3 #define BLK_INTERNAL_H
   4
   5 #include <linux/idr.h>
   6 #include <linux/blk-mq.h>
   7 #include "blk-mq.h"
   8
   9 /* Amount of time in which a process may batch requests */
  10 #define BLK_BATCH_TIME  (HZ/50UL)
  11
  12 /* Number of requests a "batching" process may submit */
  13 #define BLK_BATCH_REQ   32
  14
  15 /* Max future timer expiry for timeouts */
  16 #define BLK_MAX_TIMEOUT         (5 * HZ)
  17
  18 #ifdef CONFIG_DEBUG_FS
  19 extern struct dentry *blk_debugfs_root;
  20 #endif
  21
  22 struct blk_flush_queue {
  23         unsigned int            flush_queue_delayed:1;
  24         unsigned int            flush_pending_idx:1;
  25         unsigned int            flush_running_idx:1;
  26         unsigned long           flush_pending_since;
  27         struct list_head        flush_queue[2];
  28         struct list_head        flush_data_in_flight;
  29         struct request          *flush_rq;
  30
  31         /*
  32          * flush_rq shares tag with this rq, both can't be active
  33          * at the same time
  34          */
  35         struct request          *orig_rq;
  36         spinlock_t              mq_flush_lock;
  37 };
  38
  39 extern struct kmem_cache *blk_requestq_cachep;
  40 extern struct kmem_cache *request_cachep;
  41 extern struct kobj_type blk_queue_ktype;
  42 extern struct ida blk_queue_ida;
  43
  44 /*
  45  * @q->queue_lock is set while a queue is being initialized. Since we know
  46  * that no other threads access the queue object before @q->queue_lock has
  47  * been set, it is safe to manipulate queue flags without holding the
  48  * queue_lock if @q->queue_lock == NULL. See also blk_alloc_queue_node() and
  49  * blk_init_allocated_queue().
  50  */
  51 static inline void queue_lockdep_assert_held(struct request_queue *q)
  52 {
  53         if (q->queue_lock)
  54                 lockdep_assert_held(q->queue_lock);
  55 }
  56
  57 static inline void queue_flag_set_unlocked(unsigned int flag,
  58                                            struct request_queue *q)
  59 {
  60         if (test_bit(QUEUE_FLAG_INIT_DONE, &q->queue_flags) &&
  61             kref_read(&q->kobj.kref))
  62                 lockdep_assert_held(q->queue_lock);
  63         __set_bit(flag, &q->queue_flags);
  64 }
  65
  66 static inline void queue_flag_clear_unlocked(unsigned int flag,
  67                                              struct request_queue *q)
  68 {
  69         if (test_bit(QUEUE_FLAG_INIT_DONE, &q->queue_flags) &&
  70             kref_read(&q->kobj.kref))
  71                 lockdep_assert_held(q->queue_lock);
  72         __clear_bit(flag, &q->queue_flags);
  73 }
  74
  75 static inline int queue_flag_test_and_clear(unsigned int flag,
  76                                             struct request_queue *q)
  77 {
  78         queue_lockdep_assert_held(q);
  79
  80         if (test_bit(flag, &q->queue_flags)) {
  81                 __clear_bit(flag, &q->queue_flags);
  82                 return 1;
  83         }
  84
  85         return 0;
  86 }
  87
  88 static inline int queue_flag_test_and_set(unsigned int flag,
  89                                           struct request_queue *q)
  90 {
  91         queue_lockdep_assert_held(q);
  92
  93         if (!test_bit(flag, &q->queue_flags)) {
  94                 __set_bit(flag, &q->queue_flags);
  95                 return 0;
  96         }
  97
  98         return 1;
  99 }
 100
 101 static inline void queue_flag_set(unsigned int flag, struct request_queue *q)
 102 {
 103         queue_lockdep_assert_held(q);
 104         __set_bit(flag, &q->queue_flags);
 105 }
 106
 107 static inline void queue_flag_clear(unsigned int flag, struct request_queue *q)
 108 {
 109         queue_lockdep_assert_held(q);
 110         __clear_bit(flag, &q->queue_flags);
 111 }
 112
 113 static inline struct blk_flush_queue *blk_get_flush_queue(
 114                 struct request_queue *q, struct blk_mq_ctx *ctx)
 115 {
 116         if (q->mq_ops)
 117                 return blk_mq_map_queue(q, ctx->cpu)->fq;
 118         return q->fq;
 119 }
 120
 121 static inline void __blk_get_queue(struct request_queue *q)
 122 {
 123         kobject_get(&q->kobj);
 124 }
 125
 126 struct blk_flush_queue *blk_alloc_flush_queue(struct request_queue *q,
 127                 int node, int cmd_size);
 128 void blk_free_flush_queue(struct blk_flush_queue *q);
 129
 130 int blk_init_rl(struct request_list *rl, struct request_queue *q,
 131                 gfp_t gfp_mask);
 132 void blk_exit_rl(struct request_queue *q, struct request_list *rl);
 133 void blk_exit_queue(struct request_queue *q);
 134 void blk_rq_bio_prep(struct request_queue *q, struct request *rq,
 135                         struct bio *bio);
 136 void blk_queue_bypass_start(struct request_queue *q);
 137 void blk_queue_bypass_end(struct request_queue *q);
 138 void __blk_queue_free_tags(struct request_queue *q);
 139 void blk_freeze_queue(struct request_queue *q);
 140
 141 static inline void blk_queue_enter_live(struct request_queue *q)
 142 {
 143         /*
 144          * Given that running in generic_make_request() context
 145          * guarantees that a live reference against q_usage_counter has
 146          * been established, further references under that same context
 147          * need not check that the queue has been frozen (marked dead).
 148          */
 149         percpu_ref_get(&q->q_usage_counter);
 150 }
 151
 152 #ifdef CONFIG_BLK_DEV_INTEGRITY
 153 void blk_flush_integrity(void);
 154 bool __bio_integrity_endio(struct bio *);
 155 static inline bool bio_integrity_endio(struct bio *bio)
 156 {
 157         if (bio_integrity(bio))
 158                 return __bio_integrity_endio(bio);
 159         return true;
 160 }
 161 #else
 162 static inline void blk_flush_integrity(void)
 163 {
 164 }
 165 static inline bool bio_integrity_endio(struct bio *bio)
 166 {
 167         return true;
 168 }
 169 #endif
 170
 171 void blk_timeout_work(struct work_struct *work);
 172 unsigned long blk_rq_timeout(unsigned long timeout);
 173 void blk_add_timer(struct request *req);
 174 void blk_delete_timer(struct request *);
 175
 176
 177 bool bio_attempt_front_merge(struct request_queue *q, struct request *req,
 178                              struct bio *bio);
 179 bool bio_attempt_back_merge(struct request_queue *q, struct request *req,
 180                             struct bio *bio);
 181 bool bio_attempt_discard_merge(struct request_queue *q, struct request *req,
 182                 struct bio *bio);
 183 bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio,
 184                             unsigned int *request_count,
 185                             struct request **same_queue_rq);
 186 unsigned int blk_plug_queued_count(struct request_queue *q);
 187
 188 void blk_account_io_start(struct request *req, bool new_io);
 189 void blk_account_io_completion(struct request *req, unsigned int bytes);
 190 void blk_account_io_done(struct request *req, u64 now);
 191
 192 /*
 193  * EH timer and IO completion will both attempt to 'grab' the request, make
 194  * sure that only one of them succeeds. Steal the bottom bit of the
 195  * __deadline field for this.
 196  */
 197 static inline int blk_mark_rq_complete(struct request *rq)
 198 {
 199         return test_and_set_bit(0, &rq->__deadline);
 200 }
 201
 202 static inline void blk_clear_rq_complete(struct request *rq)
 203 {
 204         clear_bit(0, &rq->__deadline);
 205 }
 206
 207 static inline bool blk_rq_is_complete(struct request *rq)
 208 {
 209         return test_bit(0, &rq->__deadline);
 210 }
 211
 212 /*
 213  * Internal elevator interface
 214  */
 215 #define ELV_ON_HASH(rq) ((rq)->rq_flags & RQF_HASHED)
 216
 217 void blk_insert_flush(struct request *rq);
 218
 219 static inline void elv_activate_rq(struct request_queue *q, struct request *rq)
 220 {
 221         struct elevator_queue *e = q->elevator;
 222
 223         if (e->type->ops.sq.elevator_activate_req_fn)
 224                 e->type->ops.sq.elevator_activate_req_fn(q, rq);
 225 }
 226
 227 static inline void elv_deactivate_rq(struct request_queue *q, struct request *rq)
 228 {
 229         struct elevator_queue *e = q->elevator;
 230
 231         if (e->type->ops.sq.elevator_deactivate_req_fn)
 232                 e->type->ops.sq.elevator_deactivate_req_fn(q, rq);
 233 }
 234
 235 int elevator_init(struct request_queue *);
 236 int elevator_init_mq(struct request_queue *q);
 237 int elevator_switch_mq(struct request_queue *q,
 238                               struct elevator_type *new_e);
 239 void elevator_exit(struct request_queue *, struct elevator_queue *);
 240 int elv_register_queue(struct request_queue *q);
 241 void elv_unregister_queue(struct request_queue *q);
 242
 243 struct hd_struct *__disk_get_part(struct gendisk *disk, int partno);
 244
 245 #ifdef CONFIG_FAIL_IO_TIMEOUT
 246 int blk_should_fake_timeout(struct request_queue *);
 247 ssize_t part_timeout_show(struct device *, struct device_attribute *, char *);
 248 ssize_t part_timeout_store(struct device *, struct device_attribute *,
 249                                 const char *, size_t);
 250 #else
 251 static inline int blk_should_fake_timeout(struct request_queue *q)
 252 {
 253         return 0;
 254 }
 255 #endif
 256
 257 int ll_back_merge_fn(struct request_queue *q, struct request *req,
 258                      struct bio *bio);
 259 int ll_front_merge_fn(struct request_queue *q, struct request *req,
 260                       struct bio *bio);
 261 struct request *attempt_back_merge(struct request_queue *q, struct request *rq);
 262 struct request *attempt_front_merge(struct request_queue *q, struct request *rq);
 263 int blk_attempt_req_merge(struct request_queue *q, struct request *rq,
 264                                 struct request *next);
 265 void blk_recalc_rq_segments(struct request *rq);
 266 void blk_rq_set_mixed_merge(struct request *rq);
 267 bool blk_rq_merge_ok(struct request *rq, struct bio *bio);
 268 enum elv_merge blk_try_merge(struct request *rq, struct bio *bio);
 269
 270 void blk_queue_congestion_threshold(struct request_queue *q);
 271
 272 int blk_dev_init(void);
 273
 274
 275 /*
 276  * Return the threshold (number of used requests) at which the queue is
 277  * considered to be congested.  It include a little hysteresis to keep the
 278  * context switch rate down.
 279  */
 280 static inline int queue_congestion_on_threshold(struct request_queue *q)
 281 {
 282         return q->nr_congestion_on;
 283 }
 284
 285 /*
 286  * The threshold at which a queue is considered to be uncongested
 287  */
 288 static inline int queue_congestion_off_threshold(struct request_queue *q)
 289 {
 290         return q->nr_congestion_off;
 291 }
 292
 293 extern int blk_update_nr_requests(struct request_queue *, unsigned int);
 294
 295 /*
 296  * Contribute to IO statistics IFF:
 297  *
 298  *      a) it's attached to a gendisk, and
 299  *      b) the queue had IO stats enabled when this request was started, and
 300  *      c) it's a file system request
 301  */
 302 static inline bool blk_do_io_stat(struct request *rq)
 303 {
 304         return rq->rq_disk &&
 305                (rq->rq_flags & RQF_IO_STAT) &&
 306                 !blk_rq_is_passthrough(rq);
 307 }
 308
 309 static inline void req_set_nomerge(struct request_queue *q, struct request *req)
 310 {
 311         req->cmd_flags |= REQ_NOMERGE;
 312         if (req == q->last_merge)
 313                 q->last_merge = NULL;
 314 }
 315
 316 /*
 317  * Steal a bit from this field for legacy IO path atomic IO marking. Note that
 318  * setting the deadline clears the bottom bit, potentially clearing the
 319  * completed bit. The user has to be OK with this (current ones are fine).
 320  */
 321 static inline void blk_rq_set_deadline(struct request *rq, unsigned long time)
 322 {
 323         rq->__deadline = time & ~0x1UL;
 324 }
 325
 326 static inline unsigned long blk_rq_deadline(struct request *rq)
 327 {
 328         return rq->__deadline & ~0x1UL;
 329 }
 330
 331 /*
 332  * Internal io_context interface
 333  */
 334 void get_io_context(struct io_context *ioc);
 335 struct io_cq *ioc_lookup_icq(struct io_context *ioc, struct request_queue *q);
 336 struct io_cq *ioc_create_icq(struct io_context *ioc, struct request_queue *q,
 337                              gfp_t gfp_mask);
 338 void ioc_clear_queue(struct request_queue *q);
 339
 340 int create_task_io_context(struct task_struct *task, gfp_t gfp_mask, int node);
 341
 342 /**
 343  * rq_ioc - determine io_context for request allocation
 344  * @bio: request being allocated is for this bio (can be %NULL)
 345  *
 346  * Determine io_context to use for request allocation for @bio.  May return
 347  * %NULL if %current->io_context doesn't exist.
 348  */
 349 static inline struct io_context *rq_ioc(struct bio *bio)
 350 {
 351 #ifdef CONFIG_BLK_CGROUP
 352         if (bio && bio->bi_ioc)
 353                 return bio->bi_ioc;
 354 #endif
 355         return current->io_context;
 356 }
 357
 358 /**
 359  * create_io_context - try to create task->io_context
 360  * @gfp_mask: allocation mask
 361  * @node: allocation node
 362  *
 363  * If %current->io_context is %NULL, allocate a new io_context and install
 364  * it.  Returns the current %current->io_context which may be %NULL if
 365  * allocation failed.
 366  *
 367  * Note that this function can't be called with IRQ disabled because
 368  * task_lock which protects %current->io_context is IRQ-unsafe.
 369  */
 370 static inline struct io_context *create_io_context(gfp_t gfp_mask, int node)
 371 {
 372         WARN_ON_ONCE(irqs_disabled());
 373         if (unlikely(!current->io_context))
 374                 create_task_io_context(current, gfp_mask, node);
 375         return current->io_context;
 376 }
 377
 378 /*
 379  * Internal throttling interface
 380  */
 381 #ifdef CONFIG_BLK_DEV_THROTTLING
 382 extern void blk_throtl_drain(struct request_queue *q);
 383 extern int blk_throtl_init(struct request_queue *q);
 384 extern void blk_throtl_exit(struct request_queue *q);
 385 extern void blk_throtl_register_queue(struct request_queue *q);
 386 #else /* CONFIG_BLK_DEV_THROTTLING */
 387 static inline void blk_throtl_drain(struct request_queue *q) { }
 388 static inline int blk_throtl_init(struct request_queue *q) { return 0; }
 389 static inline void blk_throtl_exit(struct request_queue *q) { }
 390 static inline void blk_throtl_register_queue(struct request_queue *q) { }
 391 #endif /* CONFIG_BLK_DEV_THROTTLING */
 392 #ifdef CONFIG_BLK_DEV_THROTTLING_LOW
 393 extern ssize_t blk_throtl_sample_time_show(struct request_queue *q, char *page);
 394 extern ssize_t blk_throtl_sample_time_store(struct request_queue *q,
 395         const char *page, size_t count);
 396 extern void blk_throtl_bio_endio(struct bio *bio);
 397 extern void blk_throtl_stat_add(struct request *rq, u64 time);
 398 #else
 399 static inline void blk_throtl_bio_endio(struct bio *bio) { }
 400 static inline void blk_throtl_stat_add(struct request *rq, u64 time) { }
 401 #endif
 402
 403 #ifdef CONFIG_BOUNCE
 404 extern int init_emergency_isa_pool(void);
 405 extern void blk_queue_bounce(struct request_queue *q, struct bio **bio);
 406 #else
 407 static inline int init_emergency_isa_pool(void)
 408 {
 409         return 0;
 410 }
 411 static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio)
 412 {
 413 }
 414 #endif /* CONFIG_BOUNCE */
 415
 416 extern void blk_drain_queue(struct request_queue *q);
 417
 418 #ifdef CONFIG_BLK_CGROUP_IOLATENCY
 419 extern int blk_iolatency_init(struct request_queue *q);
 420 #else
 421 static inline int blk_iolatency_init(struct request_queue *q) { return 0; }
 422 #endif
 423
 424 #endif /* BLK_INTERNAL_H */