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         blk_status_t            rq_status;
  27         unsigned long           flush_pending_since;
  28         struct list_head        flush_queue[2];
  29         struct list_head        flush_data_in_flight;
  30         struct request          *flush_rq;
  31
  32         /*
  33          * flush_rq shares tag with this rq, both can't be active
  34          * at the same time
  35          */
  36         struct request          *orig_rq;
  37         spinlock_t              mq_flush_lock;
  38 };
  39
  40 extern struct kmem_cache *blk_requestq_cachep;
  41 extern struct kmem_cache *request_cachep;
  42 extern struct kobj_type blk_queue_ktype;
  43 extern struct ida blk_queue_ida;
  44
  45 /*
  46  * @q->queue_lock is set while a queue is being initialized. Since we know
  47  * that no other threads access the queue object before @q->queue_lock has
  48  * been set, it is safe to manipulate queue flags without holding the
  49  * queue_lock if @q->queue_lock == NULL. See also blk_alloc_queue_node() and
  50  * blk_init_allocated_queue().
  51  */
  52 static inline void queue_lockdep_assert_held(struct request_queue *q)
  53 {
  54         if (q->queue_lock)
  55                 lockdep_assert_held(q->queue_lock);
  56 }
  57
  58 static inline void queue_flag_set_unlocked(unsigned int flag,
  59                                            struct request_queue *q)
  60 {
  61         if (test_bit(QUEUE_FLAG_INIT_DONE, &q->queue_flags) &&
  62             kref_read(&q->kobj.kref))
  63                 lockdep_assert_held(q->queue_lock);
  64         __set_bit(flag, &q->queue_flags);
  65 }
  66
  67 static inline void queue_flag_clear_unlocked(unsigned int flag,
  68                                              struct request_queue *q)
  69 {
  70         if (test_bit(QUEUE_FLAG_INIT_DONE, &q->queue_flags) &&
  71             kref_read(&q->kobj.kref))
  72                 lockdep_assert_held(q->queue_lock);
  73         __clear_bit(flag, &q->queue_flags);
  74 }
  75
  76 static inline int queue_flag_test_and_clear(unsigned int flag,
  77                                             struct request_queue *q)
  78 {
  79         queue_lockdep_assert_held(q);
  80
  81         if (test_bit(flag, &q->queue_flags)) {
  82                 __clear_bit(flag, &q->queue_flags);
  83                 return 1;
  84         }
  85
  86         return 0;
  87 }
  88
  89 static inline int queue_flag_test_and_set(unsigned int flag,
  90                                           struct request_queue *q)
  91 {
  92         queue_lockdep_assert_held(q);
  93
  94         if (!test_bit(flag, &q->queue_flags)) {
  95                 __set_bit(flag, &q->queue_flags);
  96                 return 0;
  97         }
  98
  99         return 1;
 100 }
 101
 102 static inline void queue_flag_set(unsigned int flag, struct request_queue *q)
 103 {
 104         queue_lockdep_assert_held(q);
 105         __set_bit(flag, &q->queue_flags);
 106 }
 107
 108 static inline void queue_flag_clear(unsigned int flag, struct request_queue *q)
 109 {
 110         queue_lockdep_assert_held(q);
 111         __clear_bit(flag, &q->queue_flags);
 112 }
 113
 114 static inline struct blk_flush_queue *blk_get_flush_queue(
 115                 struct request_queue *q, struct blk_mq_ctx *ctx)
 116 {
 117         if (q->mq_ops)
 118                 return blk_mq_map_queue(q, ctx->cpu)->fq;
 119         return q->fq;
 120 }
 121
 122 static inline void __blk_get_queue(struct request_queue *q)
 123 {
 124         kobject_get(&q->kobj);
 125 }
 126
 127 static inline bool
 128 is_flush_rq(struct request *req, struct blk_mq_hw_ctx *hctx)
 129 {
 130         return hctx->fq->flush_rq == req;
 131 }
 132
 133 struct blk_flush_queue *blk_alloc_flush_queue(struct request_queue *q,
 134                 int node, int cmd_size, gfp_t flags);
 135 void blk_free_flush_queue(struct blk_flush_queue *q);
 136
 137 int blk_init_rl(struct request_list *rl, struct request_queue *q,
 138                 gfp_t gfp_mask);
 139 void blk_exit_rl(struct request_queue *q, struct request_list *rl);
 140 void blk_exit_queue(struct request_queue *q);
 141 void blk_rq_bio_prep(struct request_queue *q, struct request *rq,
 142                         struct bio *bio);
 143 void blk_queue_bypass_start(struct request_queue *q);
 144 void blk_queue_bypass_end(struct request_queue *q);
 145 void __blk_queue_free_tags(struct request_queue *q);
 146 void blk_freeze_queue(struct request_queue *q);
 147
 148 static inline void blk_queue_enter_live(struct request_queue *q)
 149 {
 150         /*
 151          * Given that running in generic_make_request() context
 152          * guarantees that a live reference against q_usage_counter has
 153          * been established, further references under that same context
 154          * need not check that the queue has been frozen (marked dead).
 155          */
 156         percpu_ref_get(&q->q_usage_counter);
 157 }
 158
 159 #ifdef CONFIG_BLK_DEV_INTEGRITY
 160 void blk_flush_integrity(void);
 161 bool __bio_integrity_endio(struct bio *);
 162 static inline bool bio_integrity_endio(struct bio *bio)
 163 {
 164         if (bio_integrity(bio))
 165                 return __bio_integrity_endio(bio);
 166         return true;
 167 }
 168 #else
 169 static inline void blk_flush_integrity(void)
 170 {
 171 }
 172 static inline bool bio_integrity_endio(struct bio *bio)
 173 {
 174         return true;
 175 }
 176 #endif
 177
 178 void blk_timeout_work(struct work_struct *work);
 179 unsigned long blk_rq_timeout(unsigned long timeout);
 180 void blk_add_timer(struct request *req);
 181 void blk_delete_timer(struct request *);
 182
 183
 184 bool bio_attempt_front_merge(struct request_queue *q, struct request *req,
 185                              struct bio *bio);
 186 bool bio_attempt_back_merge(struct request_queue *q, struct request *req,
 187                             struct bio *bio);
 188 bool bio_attempt_discard_merge(struct request_queue *q, struct request *req,
 189                 struct bio *bio);
 190 bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio,
 191                             unsigned int *request_count,
 192                             struct request **same_queue_rq);
 193 unsigned int blk_plug_queued_count(struct request_queue *q);
 194
 195 void blk_account_io_start(struct request *req, bool new_io);
 196 void blk_account_io_completion(struct request *req, unsigned int bytes);
 197 void blk_account_io_done(struct request *req, u64 now);
 198
 199 /*
 200  * EH timer and IO completion will both attempt to 'grab' the request, make
 201  * sure that only one of them succeeds. Steal the bottom bit of the
 202  * __deadline field for this.
 203  */
 204 static inline int blk_mark_rq_complete(struct request *rq)
 205 {
 206         return test_and_set_bit(0, &rq->__deadline);
 207 }
 208
 209 static inline void blk_clear_rq_complete(struct request *rq)
 210 {
 211         clear_bit(0, &rq->__deadline);
 212 }
 213
 214 static inline bool blk_rq_is_complete(struct request *rq)
 215 {
 216         return test_bit(0, &rq->__deadline);
 217 }
 218
 219 /*
 220  * Internal elevator interface
 221  */
 222 #define ELV_ON_HASH(rq) ((rq)->rq_flags & RQF_HASHED)
 223
 224 void blk_insert_flush(struct request *rq);
 225
 226 static inline void elv_activate_rq(struct request_queue *q, struct request *rq)
 227 {
 228         struct elevator_queue *e = q->elevator;
 229
 230         if (e->type->ops.sq.elevator_activate_req_fn)
 231                 e->type->ops.sq.elevator_activate_req_fn(q, rq);
 232 }
 233
 234 static inline void elv_deactivate_rq(struct request_queue *q, struct request *rq)
 235 {
 236         struct elevator_queue *e = q->elevator;
 237
 238         if (e->type->ops.sq.elevator_deactivate_req_fn)
 239                 e->type->ops.sq.elevator_deactivate_req_fn(q, rq);
 240 }
 241
 242 int elevator_init(struct request_queue *);
 243 int elevator_init_mq(struct request_queue *q);
 244 int elevator_switch_mq(struct request_queue *q,
 245                               struct elevator_type *new_e);
 246 void elevator_exit(struct request_queue *, struct elevator_queue *);
 247 int elv_register_queue(struct request_queue *q);
 248 void elv_unregister_queue(struct request_queue *q);
 249
 250 struct hd_struct *__disk_get_part(struct gendisk *disk, int partno);
 251
 252 #ifdef CONFIG_FAIL_IO_TIMEOUT
 253 int blk_should_fake_timeout(struct request_queue *);
 254 ssize_t part_timeout_show(struct device *, struct device_attribute *, char *);
 255 ssize_t part_timeout_store(struct device *, struct device_attribute *,
 256                                 const char *, size_t);
 257 #else
 258 static inline int blk_should_fake_timeout(struct request_queue *q)
 259 {
 260         return 0;
 261 }
 262 #endif
 263
 264 int ll_back_merge_fn(struct request_queue *q, struct request *req,
 265                      struct bio *bio);
 266 int ll_front_merge_fn(struct request_queue *q, struct request *req,
 267                       struct bio *bio);
 268 struct request *attempt_back_merge(struct request_queue *q, struct request *rq);
 269 struct request *attempt_front_merge(struct request_queue *q, struct request *rq);
 270 int blk_attempt_req_merge(struct request_queue *q, struct request *rq,
 271                                 struct request *next);
 272 void blk_recalc_rq_segments(struct request *rq);
 273 void blk_rq_set_mixed_merge(struct request *rq);
 274 bool blk_rq_merge_ok(struct request *rq, struct bio *bio);
 275 enum elv_merge blk_try_merge(struct request *rq, struct bio *bio);
 276
 277 void blk_queue_congestion_threshold(struct request_queue *q);
 278
 279 int blk_dev_init(void);
 280
 281
 282 /*
 283  * Return the threshold (number of used requests) at which the queue is
 284  * considered to be congested.  It include a little hysteresis to keep the
 285  * context switch rate down.
 286  */
 287 static inline int queue_congestion_on_threshold(struct request_queue *q)
 288 {
 289         return q->nr_congestion_on;
 290 }
 291
 292 /*
 293  * The threshold at which a queue is considered to be uncongested
 294  */
 295 static inline int queue_congestion_off_threshold(struct request_queue *q)
 296 {
 297         return q->nr_congestion_off;
 298 }
 299
 300 extern int blk_update_nr_requests(struct request_queue *, unsigned int);
 301
 302 /*
 303  * Contribute to IO statistics IFF:
 304  *
 305  *      a) it's attached to a gendisk, and
 306  *      b) the queue had IO stats enabled when this request was started, and
 307  *      c) it's a file system request
 308  */
 309 static inline bool blk_do_io_stat(struct request *rq)
 310 {
 311         return rq->rq_disk &&
 312                (rq->rq_flags & RQF_IO_STAT) &&
 313                 !blk_rq_is_passthrough(rq);
 314 }
 315
 316 static inline void req_set_nomerge(struct request_queue *q, struct request *req)
 317 {
 318         req->cmd_flags |= REQ_NOMERGE;
 319         if (req == q->last_merge)
 320                 q->last_merge = NULL;
 321 }
 322
 323 /*
 324  * Steal a bit from this field for legacy IO path atomic IO marking. Note that
 325  * setting the deadline clears the bottom bit, potentially clearing the
 326  * completed bit. The user has to be OK with this (current ones are fine).
 327  */
 328 static inline void blk_rq_set_deadline(struct request *rq, unsigned long time)
 329 {
 330         rq->__deadline = time & ~0x1UL;
 331 }
 332
 333 static inline unsigned long blk_rq_deadline(struct request *rq)
 334 {
 335         return rq->__deadline & ~0x1UL;
 336 }
 337
 338 /*
 339  * The max size one bio can handle is UINT_MAX becasue bvec_iter.bi_size
 340  * is defined as 'unsigned int', meantime it has to aligned to with logical
 341  * block size which is the minimum accepted unit by hardware.
 342  */
 343 static inline unsigned int bio_allowed_max_sectors(struct request_queue *q)
 344 {
 345         return round_down(UINT_MAX, queue_logical_block_size(q)) >> 9;
 346 }
 347
 348 /*
 349  * Internal io_context interface
 350  */
 351 void get_io_context(struct io_context *ioc);
 352 struct io_cq *ioc_lookup_icq(struct io_context *ioc, struct request_queue *q);
 353 struct io_cq *ioc_create_icq(struct io_context *ioc, struct request_queue *q,
 354                              gfp_t gfp_mask);
 355 void ioc_clear_queue(struct request_queue *q);
 356
 357 int create_task_io_context(struct task_struct *task, gfp_t gfp_mask, int node);
 358
 359 /**
 360  * rq_ioc - determine io_context for request allocation
 361  * @bio: request being allocated is for this bio (can be %NULL)
 362  *
 363  * Determine io_context to use for request allocation for @bio.  May return
 364  * %NULL if %current->io_context doesn't exist.
 365  */
 366 static inline struct io_context *rq_ioc(struct bio *bio)
 367 {
 368 #ifdef CONFIG_BLK_CGROUP
 369         if (bio && bio->bi_ioc)
 370                 return bio->bi_ioc;
 371 #endif
 372         return current->io_context;
 373 }
 374
 375 /**
 376  * create_io_context - try to create task->io_context
 377  * @gfp_mask: allocation mask
 378  * @node: allocation node
 379  *
 380  * If %current->io_context is %NULL, allocate a new io_context and install
 381  * it.  Returns the current %current->io_context which may be %NULL if
 382  * allocation failed.
 383  *
 384  * Note that this function can't be called with IRQ disabled because
 385  * task_lock which protects %current->io_context is IRQ-unsafe.
 386  */
 387 static inline struct io_context *create_io_context(gfp_t gfp_mask, int node)
 388 {
 389         WARN_ON_ONCE(irqs_disabled());
 390         if (unlikely(!current->io_context))
 391                 create_task_io_context(current, gfp_mask, node);
 392         return current->io_context;
 393 }
 394
 395 /*
 396  * Internal throttling interface
 397  */
 398 #ifdef CONFIG_BLK_DEV_THROTTLING
 399 extern void blk_throtl_drain(struct request_queue *q);
 400 extern int blk_throtl_init(struct request_queue *q);
 401 extern void blk_throtl_exit(struct request_queue *q);
 402 extern void blk_throtl_register_queue(struct request_queue *q);
 403 #else /* CONFIG_BLK_DEV_THROTTLING */
 404 static inline void blk_throtl_drain(struct request_queue *q) { }
 405 static inline int blk_throtl_init(struct request_queue *q) { return 0; }
 406 static inline void blk_throtl_exit(struct request_queue *q) { }
 407 static inline void blk_throtl_register_queue(struct request_queue *q) { }
 408 #endif /* CONFIG_BLK_DEV_THROTTLING */
 409 #ifdef CONFIG_BLK_DEV_THROTTLING_LOW
 410 extern ssize_t blk_throtl_sample_time_show(struct request_queue *q, char *page);
 411 extern ssize_t blk_throtl_sample_time_store(struct request_queue *q,
 412         const char *page, size_t count);
 413 extern void blk_throtl_bio_endio(struct bio *bio);
 414 extern void blk_throtl_stat_add(struct request *rq, u64 time);
 415 #else
 416 static inline void blk_throtl_bio_endio(struct bio *bio) { }
 417 static inline void blk_throtl_stat_add(struct request *rq, u64 time) { }
 418 #endif
 419
 420 #ifdef CONFIG_BOUNCE
 421 extern int init_emergency_isa_pool(void);
 422 extern void blk_queue_bounce(struct request_queue *q, struct bio **bio);
 423 #else
 424 static inline int init_emergency_isa_pool(void)
 425 {
 426         return 0;
 427 }
 428 static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio)
 429 {
 430 }
 431 #endif /* CONFIG_BOUNCE */
 432
 433 extern void blk_drain_queue(struct request_queue *q);
 434
 435 #ifdef CONFIG_BLK_CGROUP_IOLATENCY
 436 extern int blk_iolatency_init(struct request_queue *q);
 437 #else
 438 static inline int blk_iolatency_init(struct request_queue *q) { return 0; }
 439 #endif
 440
 441 #endif /* BLK_INTERNAL_H */