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 <linux/part_stat.h>
   8 #include <xen/xen.h>
   9 #include "blk-mq.h"
  10 #include "blk-mq-sched.h"
  11
  12 /* Max future timer expiry for timeouts */
  13 #define BLK_MAX_TIMEOUT         (5 * HZ)
  14
  15 #ifdef CONFIG_DEBUG_FS
  16 extern struct dentry *blk_debugfs_root;
  17 #endif
  18
  19 struct blk_flush_queue {
  20         unsigned int            flush_queue_delayed:1;
  21         unsigned int            flush_pending_idx:1;
  22         unsigned int            flush_running_idx:1;
  23         blk_status_t            rq_status;
  24         unsigned long           flush_pending_since;
  25         struct list_head        flush_queue[2];
  26         struct list_head        flush_data_in_flight;
  27         struct request          *flush_rq;
  28
  29         /*
  30          * flush_rq shares tag with this rq, both can't be active
  31          * at the same time
  32          */
  33         struct request          *orig_rq;
  34         struct lock_class_key   key;
  35         spinlock_t              mq_flush_lock;
  36 };
  37
  38 extern struct kmem_cache *blk_requestq_cachep;
  39 extern struct kobj_type blk_queue_ktype;
  40 extern struct ida blk_queue_ida;
  41
  42 static inline struct blk_flush_queue *
  43 blk_get_flush_queue(struct request_queue *q, struct blk_mq_ctx *ctx)
  44 {
  45         return blk_mq_map_queue(q, REQ_OP_FLUSH, ctx)->fq;
  46 }
  47
  48 static inline void __blk_get_queue(struct request_queue *q)
  49 {
  50         kobject_get(&q->kobj);
  51 }
  52
  53 static inline bool
  54 is_flush_rq(struct request *req, struct blk_mq_hw_ctx *hctx)
  55 {
  56         return hctx->fq->flush_rq == req;
  57 }
  58
  59 struct blk_flush_queue *blk_alloc_flush_queue(int node, int cmd_size,
  60                                               gfp_t flags);
  61 void blk_free_flush_queue(struct blk_flush_queue *q);
  62
  63 void blk_freeze_queue(struct request_queue *q);
  64
  65 static inline void blk_queue_enter_live(struct request_queue *q)
  66 {
  67         /*
  68          * Given that running in generic_make_request() context
  69          * guarantees that a live reference against q_usage_counter has
  70          * been established, further references under that same context
  71          * need not check that the queue has been frozen (marked dead).
  72          */
  73         percpu_ref_get(&q->q_usage_counter);
  74 }
  75
  76 static inline bool biovec_phys_mergeable(struct request_queue *q,
  77                 struct bio_vec *vec1, struct bio_vec *vec2)
  78 {
  79         unsigned long mask = queue_segment_boundary(q);
  80         phys_addr_t addr1 = page_to_phys(vec1->bv_page) + vec1->bv_offset;
  81         phys_addr_t addr2 = page_to_phys(vec2->bv_page) + vec2->bv_offset;
  82
  83         if (addr1 + vec1->bv_len != addr2)
  84                 return false;
  85         if (xen_domain() && !xen_biovec_phys_mergeable(vec1, vec2->bv_page))
  86                 return false;
  87         if ((addr1 | mask) != ((addr2 + vec2->bv_len - 1) | mask))
  88                 return false;
  89         return true;
  90 }
  91
  92 static inline bool __bvec_gap_to_prev(struct request_queue *q,
  93                 struct bio_vec *bprv, unsigned int offset)
  94 {
  95         return (offset & queue_virt_boundary(q)) ||
  96                 ((bprv->bv_offset + bprv->bv_len) & queue_virt_boundary(q));
  97 }
  98
  99 /*
 100  * Check if adding a bio_vec after bprv with offset would create a gap in
 101  * the SG list. Most drivers don't care about this, but some do.
 102  */
 103 static inline bool bvec_gap_to_prev(struct request_queue *q,
 104                 struct bio_vec *bprv, unsigned int offset)
 105 {
 106         if (!queue_virt_boundary(q))
 107                 return false;
 108         return __bvec_gap_to_prev(q, bprv, offset);
 109 }
 110
 111 static inline void blk_rq_bio_prep(struct request *rq, struct bio *bio,
 112                 unsigned int nr_segs)
 113 {
 114         rq->nr_phys_segments = nr_segs;
 115         rq->__data_len = bio->bi_iter.bi_size;
 116         rq->bio = rq->biotail = bio;
 117         rq->ioprio = bio_prio(bio);
 118
 119         if (bio->bi_disk)
 120                 rq->rq_disk = bio->bi_disk;
 121 }
 122
 123 #ifdef CONFIG_BLK_DEV_INTEGRITY
 124 void blk_flush_integrity(void);
 125 bool __bio_integrity_endio(struct bio *);
 126 void bio_integrity_free(struct bio *bio);
 127 static inline bool bio_integrity_endio(struct bio *bio)
 128 {
 129         if (bio_integrity(bio))
 130                 return __bio_integrity_endio(bio);
 131         return true;
 132 }
 133
 134 static inline bool integrity_req_gap_back_merge(struct request *req,
 135                 struct bio *next)
 136 {
 137         struct bio_integrity_payload *bip = bio_integrity(req->bio);
 138         struct bio_integrity_payload *bip_next = bio_integrity(next);
 139
 140         return bvec_gap_to_prev(req->q, &bip->bip_vec[bip->bip_vcnt - 1],
 141                                 bip_next->bip_vec[0].bv_offset);
 142 }
 143
 144 static inline bool integrity_req_gap_front_merge(struct request *req,
 145                 struct bio *bio)
 146 {
 147         struct bio_integrity_payload *bip = bio_integrity(bio);
 148         struct bio_integrity_payload *bip_next = bio_integrity(req->bio);
 149
 150         return bvec_gap_to_prev(req->q, &bip->bip_vec[bip->bip_vcnt - 1],
 151                                 bip_next->bip_vec[0].bv_offset);
 152 }
 153
 154 void blk_integrity_add(struct gendisk *);
 155 void blk_integrity_del(struct gendisk *);
 156 #else /* CONFIG_BLK_DEV_INTEGRITY */
 157 static inline bool integrity_req_gap_back_merge(struct request *req,
 158                 struct bio *next)
 159 {
 160         return false;
 161 }
 162 static inline bool integrity_req_gap_front_merge(struct request *req,
 163                 struct bio *bio)
 164 {
 165         return false;
 166 }
 167
 168 static inline void blk_flush_integrity(void)
 169 {
 170 }
 171 static inline bool bio_integrity_endio(struct bio *bio)
 172 {
 173         return true;
 174 }
 175 static inline void bio_integrity_free(struct bio *bio)
 176 {
 177 }
 178 static inline void blk_integrity_add(struct gendisk *disk)
 179 {
 180 }
 181 static inline void blk_integrity_del(struct gendisk *disk)
 182 {
 183 }
 184 #endif /* CONFIG_BLK_DEV_INTEGRITY */
 185
 186 unsigned long blk_rq_timeout(unsigned long timeout);
 187 void blk_add_timer(struct request *req);
 188
 189 bool bio_attempt_front_merge(struct request *req, struct bio *bio,
 190                 unsigned int nr_segs);
 191 bool bio_attempt_back_merge(struct request *req, struct bio *bio,
 192                 unsigned int nr_segs);
 193 bool bio_attempt_discard_merge(struct request_queue *q, struct request *req,
 194                 struct bio *bio);
 195 bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio,
 196                 unsigned int nr_segs, struct request **same_queue_rq);
 197
 198 void blk_account_io_start(struct request *req, bool new_io);
 199 void blk_account_io_completion(struct request *req, unsigned int bytes);
 200 void blk_account_io_done(struct request *req, u64 now);
 201
 202 /*
 203  * Internal elevator interface
 204  */
 205 #define ELV_ON_HASH(rq) ((rq)->rq_flags & RQF_HASHED)
 206
 207 void blk_insert_flush(struct request *rq);
 208
 209 void elevator_init_mq(struct request_queue *q);
 210 int elevator_switch_mq(struct request_queue *q,
 211                               struct elevator_type *new_e);
 212 void __elevator_exit(struct request_queue *, struct elevator_queue *);
 213 int elv_register_queue(struct request_queue *q, bool uevent);
 214 void elv_unregister_queue(struct request_queue *q);
 215
 216 static inline void elevator_exit(struct request_queue *q,
 217                 struct elevator_queue *e)
 218 {
 219         lockdep_assert_held(&q->sysfs_lock);
 220
 221         blk_mq_sched_free_requests(q);
 222         __elevator_exit(q, e);
 223 }
 224
 225 struct hd_struct *__disk_get_part(struct gendisk *disk, int partno);
 226
 227 ssize_t part_size_show(struct device *dev, struct device_attribute *attr,
 228                 char *buf);
 229 ssize_t part_stat_show(struct device *dev, struct device_attribute *attr,
 230                 char *buf);
 231 ssize_t part_inflight_show(struct device *dev, struct device_attribute *attr,
 232                 char *buf);
 233 ssize_t part_fail_show(struct device *dev, struct device_attribute *attr,
 234                 char *buf);
 235 ssize_t part_fail_store(struct device *dev, struct device_attribute *attr,
 236                 const char *buf, size_t count);
 237
 238 #ifdef CONFIG_FAIL_IO_TIMEOUT
 239 int blk_should_fake_timeout(struct request_queue *);
 240 ssize_t part_timeout_show(struct device *, struct device_attribute *, char *);
 241 ssize_t part_timeout_store(struct device *, struct device_attribute *,
 242                                 const char *, size_t);
 243 #else
 244 static inline int blk_should_fake_timeout(struct request_queue *q)
 245 {
 246         return 0;
 247 }
 248 #endif
 249
 250 void __blk_queue_split(struct request_queue *q, struct bio **bio,
 251                 unsigned int *nr_segs);
 252 int ll_back_merge_fn(struct request *req, struct bio *bio,
 253                 unsigned int nr_segs);
 254 int ll_front_merge_fn(struct request *req,  struct bio *bio,
 255                 unsigned int nr_segs);
 256 struct request *attempt_back_merge(struct request_queue *q, struct request *rq);
 257 struct request *attempt_front_merge(struct request_queue *q, struct request *rq);
 258 int blk_attempt_req_merge(struct request_queue *q, struct request *rq,
 259                                 struct request *next);
 260 unsigned int blk_recalc_rq_segments(struct request *rq);
 261 void blk_rq_set_mixed_merge(struct request *rq);
 262 bool blk_rq_merge_ok(struct request *rq, struct bio *bio);
 263 enum elv_merge blk_try_merge(struct request *rq, struct bio *bio);
 264
 265 int blk_dev_init(void);
 266
 267 /*
 268  * Contribute to IO statistics IFF:
 269  *
 270  *      a) it's attached to a gendisk, and
 271  *      b) the queue had IO stats enabled when this request was started
 272  */
 273 static inline bool blk_do_io_stat(struct request *rq)
 274 {
 275         return rq->rq_disk && (rq->rq_flags & RQF_IO_STAT);
 276 }
 277
 278 static inline void req_set_nomerge(struct request_queue *q, struct request *req)
 279 {
 280         req->cmd_flags |= REQ_NOMERGE;
 281         if (req == q->last_merge)
 282                 q->last_merge = NULL;
 283 }
 284
 285 /*
 286  * The max size one bio can handle is UINT_MAX becasue bvec_iter.bi_size
 287  * is defined as 'unsigned int', meantime it has to aligned to with logical
 288  * block size which is the minimum accepted unit by hardware.
 289  */
 290 static inline unsigned int bio_allowed_max_sectors(struct request_queue *q)
 291 {
 292         return round_down(UINT_MAX, queue_logical_block_size(q)) >> 9;
 293 }
 294
 295 /*
 296  * Internal io_context interface
 297  */
 298 void get_io_context(struct io_context *ioc);
 299 struct io_cq *ioc_lookup_icq(struct io_context *ioc, struct request_queue *q);
 300 struct io_cq *ioc_create_icq(struct io_context *ioc, struct request_queue *q,
 301                              gfp_t gfp_mask);
 302 void ioc_clear_queue(struct request_queue *q);
 303
 304 int create_task_io_context(struct task_struct *task, gfp_t gfp_mask, int node);
 305
 306 /**
 307  * create_io_context - try to create task->io_context
 308  * @gfp_mask: allocation mask
 309  * @node: allocation node
 310  *
 311  * If %current->io_context is %NULL, allocate a new io_context and install
 312  * it.  Returns the current %current->io_context which may be %NULL if
 313  * allocation failed.
 314  *
 315  * Note that this function can't be called with IRQ disabled because
 316  * task_lock which protects %current->io_context is IRQ-unsafe.
 317  */
 318 static inline struct io_context *create_io_context(gfp_t gfp_mask, int node)
 319 {
 320         WARN_ON_ONCE(irqs_disabled());
 321         if (unlikely(!current->io_context))
 322                 create_task_io_context(current, gfp_mask, node);
 323         return current->io_context;
 324 }
 325
 326 /*
 327  * Internal throttling interface
 328  */
 329 #ifdef CONFIG_BLK_DEV_THROTTLING
 330 extern void blk_throtl_drain(struct request_queue *q);
 331 extern int blk_throtl_init(struct request_queue *q);
 332 extern void blk_throtl_exit(struct request_queue *q);
 333 extern void blk_throtl_register_queue(struct request_queue *q);
 334 #else /* CONFIG_BLK_DEV_THROTTLING */
 335 static inline void blk_throtl_drain(struct request_queue *q) { }
 336 static inline int blk_throtl_init(struct request_queue *q) { return 0; }
 337 static inline void blk_throtl_exit(struct request_queue *q) { }
 338 static inline void blk_throtl_register_queue(struct request_queue *q) { }
 339 #endif /* CONFIG_BLK_DEV_THROTTLING */
 340 #ifdef CONFIG_BLK_DEV_THROTTLING_LOW
 341 extern ssize_t blk_throtl_sample_time_show(struct request_queue *q, char *page);
 342 extern ssize_t blk_throtl_sample_time_store(struct request_queue *q,
 343         const char *page, size_t count);
 344 extern void blk_throtl_bio_endio(struct bio *bio);
 345 extern void blk_throtl_stat_add(struct request *rq, u64 time);
 346 #else
 347 static inline void blk_throtl_bio_endio(struct bio *bio) { }
 348 static inline void blk_throtl_stat_add(struct request *rq, u64 time) { }
 349 #endif
 350
 351 #ifdef CONFIG_BOUNCE
 352 extern int init_emergency_isa_pool(void);
 353 extern void blk_queue_bounce(struct request_queue *q, struct bio **bio);
 354 #else
 355 static inline int init_emergency_isa_pool(void)
 356 {
 357         return 0;
 358 }
 359 static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio)
 360 {
 361 }
 362 #endif /* CONFIG_BOUNCE */
 363
 364 #ifdef CONFIG_BLK_CGROUP_IOLATENCY
 365 extern int blk_iolatency_init(struct request_queue *q);
 366 #else
 367 static inline int blk_iolatency_init(struct request_queue *q) { return 0; }
 368 #endif
 369
 370 struct bio *blk_next_bio(struct bio *bio, unsigned int nr_pages, gfp_t gfp);
 371
 372 #ifdef CONFIG_BLK_DEV_ZONED
 373 void blk_queue_free_zone_bitmaps(struct request_queue *q);
 374 #else
 375 static inline void blk_queue_free_zone_bitmaps(struct request_queue *q) {}
 376 #endif
 377
 378 void part_dec_in_flight(struct request_queue *q, struct hd_struct *part,
 379                         int rw);
 380 void part_inc_in_flight(struct request_queue *q, struct hd_struct *part,
 381                         int rw);
 382 void update_io_ticks(struct hd_struct *part, unsigned long now, bool end);
 383 struct hd_struct *disk_map_sector_rcu(struct gendisk *disk, sector_t sector);
 384
 385 int blk_alloc_devt(struct hd_struct *part, dev_t *devt);
 386 void blk_free_devt(dev_t devt);
 387 void blk_invalidate_devt(dev_t devt);
 388 char *disk_name(struct gendisk *hd, int partno, char *buf);
 389 #define ADDPART_FLAG_NONE       0
 390 #define ADDPART_FLAG_RAID       1
 391 #define ADDPART_FLAG_WHOLEDISK  2
 392 struct hd_struct *__must_check add_partition(struct gendisk *disk, int partno,
 393                 sector_t start, sector_t len, int flags,
 394                 struct partition_meta_info *info);
 395 void __delete_partition(struct percpu_ref *ref);
 396 void delete_partition(struct gendisk *disk, int partno);
 397 int disk_expand_part_tbl(struct gendisk *disk, int target);
 398
 399 static inline int hd_ref_init(struct hd_struct *part)
 400 {
 401         if (percpu_ref_init(&part->ref, __delete_partition, 0,
 402                                 GFP_KERNEL))
 403                 return -ENOMEM;
 404         return 0;
 405 }
 406
 407 static inline void hd_struct_get(struct hd_struct *part)
 408 {
 409         percpu_ref_get(&part->ref);
 410 }
 411
 412 static inline int hd_struct_try_get(struct hd_struct *part)
 413 {
 414         return percpu_ref_tryget_live(&part->ref);
 415 }
 416
 417 static inline void hd_struct_put(struct hd_struct *part)
 418 {
 419         percpu_ref_put(&part->ref);
 420 }
 421
 422 static inline void hd_struct_kill(struct hd_struct *part)
 423 {
 424         percpu_ref_kill(&part->ref);
 425 }
 426
 427 static inline void hd_free_part(struct hd_struct *part)
 428 {
 429         free_part_stats(part);
 430         kfree(part->info);
 431         percpu_ref_exit(&part->ref);
 432 }
 433
 434 /*
 435  * Any access of part->nr_sects which is not protected by partition
 436  * bd_mutex or gendisk bdev bd_mutex, should be done using this
 437  * accessor function.
 438  *
 439  * Code written along the lines of i_size_read() and i_size_write().
 440  * CONFIG_PREEMPTION case optimizes the case of UP kernel with preemption
 441  * on.
 442  */
 443 static inline sector_t part_nr_sects_read(struct hd_struct *part)
 444 {
 445 #if BITS_PER_LONG==32 && defined(CONFIG_SMP)
 446         sector_t nr_sects;
 447         unsigned seq;
 448         do {
 449                 seq = read_seqcount_begin(&part->nr_sects_seq);
 450                 nr_sects = part->nr_sects;
 451         } while (read_seqcount_retry(&part->nr_sects_seq, seq));
 452         return nr_sects;
 453 #elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPTION)
 454         sector_t nr_sects;
 455
 456         preempt_disable();
 457         nr_sects = part->nr_sects;
 458         preempt_enable();
 459         return nr_sects;
 460 #else
 461         return part->nr_sects;
 462 #endif
 463 }
 464
 465 /*
 466  * Should be called with mutex lock held (typically bd_mutex) of partition
 467  * to provide mutual exlusion among writers otherwise seqcount might be
 468  * left in wrong state leaving the readers spinning infinitely.
 469  */
 470 static inline void part_nr_sects_write(struct hd_struct *part, sector_t size)
 471 {
 472 #if BITS_PER_LONG==32 && defined(CONFIG_SMP)
 473         preempt_disable();
 474         write_seqcount_begin(&part->nr_sects_seq);
 475         part->nr_sects = size;
 476         write_seqcount_end(&part->nr_sects_seq);
 477         preempt_enable();
 478 #elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPTION)
 479         preempt_disable();
 480         part->nr_sects = size;
 481         preempt_enable();
 482 #else
 483         part->nr_sects = size;
 484 #endif
 485 }
 486
 487 struct request_queue *__blk_alloc_queue(int node_id);
 488
 489 int __bio_add_pc_page(struct request_queue *q, struct bio *bio,
 490                 struct page *page, unsigned int len, unsigned int offset,
 491                 bool *same_page);
 492
 493 #endif /* BLK_INTERNAL_H */