1 #ifndef _LINUX_BLKDEV_H 2 #define _LINUX_BLKDEV_H 3 4 #include <linux/sched.h> 5 6 #ifdef CONFIG_BLOCK 7 8 #include <linux/major.h> 9 #include <linux/genhd.h> 10 #include <linux/list.h> 11 #include <linux/llist.h> 12 #include <linux/timer.h> 13 #include <linux/workqueue.h> 14 #include <linux/pagemap.h> 15 #include <linux/backing-dev-defs.h> 16 #include <linux/wait.h> 17 #include <linux/mempool.h> 18 #include <linux/bio.h> 19 #include <linux/stringify.h> 20 #include <linux/gfp.h> 21 #include <linux/bsg.h> 22 #include <linux/smp.h> 23 #include <linux/rcupdate.h> 24 #include <linux/percpu-refcount.h> 25 #include <linux/scatterlist.h> 26 27 struct module; 28 struct scsi_ioctl_command; 29 30 struct request_queue; 31 struct elevator_queue; 32 struct blk_trace; 33 struct request; 34 struct sg_io_hdr; 35 struct bsg_job; 36 struct blkcg_gq; 37 struct blk_flush_queue; 38 struct pr_ops; 39 40 #define BLKDEV_MIN_RQ 4 41 #define BLKDEV_MAX_RQ 128 /* Default maximum */ 42 43 /* 44 * Maximum number of blkcg policies allowed to be registered concurrently. 45 * Defined here to simplify include dependency. 46 */ 47 #define BLKCG_MAX_POLS 2 48 49 struct request; 50 typedef void (rq_end_io_fn)(struct request *, int); 51 52 #define BLK_RL_SYNCFULL (1U << 0) 53 #define BLK_RL_ASYNCFULL (1U << 1) 54 55 struct request_list { 56 struct request_queue *q; /* the queue this rl belongs to */ 57 #ifdef CONFIG_BLK_CGROUP 58 struct blkcg_gq *blkg; /* blkg this request pool belongs to */ 59 #endif 60 /* 61 * count[], starved[], and wait[] are indexed by 62 * BLK_RW_SYNC/BLK_RW_ASYNC 63 */ 64 int count[2]; 65 int starved[2]; 66 mempool_t *rq_pool; 67 wait_queue_head_t wait[2]; 68 unsigned int flags; 69 }; 70 71 /* 72 * request command types 73 */ 74 enum rq_cmd_type_bits { 75 REQ_TYPE_FS = 1, /* fs request */ 76 REQ_TYPE_BLOCK_PC, /* scsi command */ 77 REQ_TYPE_DRV_PRIV, /* driver defined types from here */ 78 }; 79 80 #define BLK_MAX_CDB 16 81 82 /* 83 * Try to put the fields that are referenced together in the same cacheline. 84 * 85 * If you modify this structure, make sure to update blk_rq_init() and 86 * especially blk_mq_rq_ctx_init() to take care of the added fields. 87 */ 88 struct request { 89 struct list_head queuelist; 90 union { 91 struct call_single_data csd; 92 unsigned long fifo_time; 93 }; 94 95 struct request_queue *q; 96 struct blk_mq_ctx *mq_ctx; 97 98 u64 cmd_flags; 99 unsigned cmd_type; 100 unsigned long atomic_flags; 101 102 int cpu; 103 104 /* the following two fields are internal, NEVER access directly */ 105 unsigned int __data_len; /* total data len */ 106 sector_t __sector; /* sector cursor */ 107 108 struct bio *bio; 109 struct bio *biotail; 110 111 /* 112 * The hash is used inside the scheduler, and killed once the 113 * request reaches the dispatch list. The ipi_list is only used 114 * to queue the request for softirq completion, which is long 115 * after the request has been unhashed (and even removed from 116 * the dispatch list). 117 */ 118 union { 119 struct hlist_node hash; /* merge hash */ 120 struct list_head ipi_list; 121 }; 122 123 /* 124 * The rb_node is only used inside the io scheduler, requests 125 * are pruned when moved to the dispatch queue. So let the 126 * completion_data share space with the rb_node. 127 */ 128 union { 129 struct rb_node rb_node; /* sort/lookup */ 130 void *completion_data; 131 }; 132 133 /* 134 * Three pointers are available for the IO schedulers, if they need 135 * more they have to dynamically allocate it. Flush requests are 136 * never put on the IO scheduler. So let the flush fields share 137 * space with the elevator data. 138 */ 139 union { 140 struct { 141 struct io_cq *icq; 142 void *priv[2]; 143 } elv; 144 145 struct { 146 unsigned int seq; 147 struct list_head list; 148 rq_end_io_fn *saved_end_io; 149 } flush; 150 }; 151 152 struct gendisk *rq_disk; 153 struct hd_struct *part; 154 unsigned long start_time; 155 #ifdef CONFIG_BLK_CGROUP 156 struct request_list *rl; /* rl this rq is alloced from */ 157 unsigned long long start_time_ns; 158 unsigned long long io_start_time_ns; /* when passed to hardware */ 159 #endif 160 /* Number of scatter-gather DMA addr+len pairs after 161 * physical address coalescing is performed. 162 */ 163 unsigned short nr_phys_segments; 164 #if defined(CONFIG_BLK_DEV_INTEGRITY) 165 unsigned short nr_integrity_segments; 166 #endif 167 168 unsigned short ioprio; 169 170 void *special; /* opaque pointer available for LLD use */ 171 172 int tag; 173 int errors; 174 175 /* 176 * when request is used as a packet command carrier 177 */ 178 unsigned char __cmd[BLK_MAX_CDB]; 179 unsigned char *cmd; 180 unsigned short cmd_len; 181 182 unsigned int extra_len; /* length of alignment and padding */ 183 unsigned int sense_len; 184 unsigned int resid_len; /* residual count */ 185 void *sense; 186 187 unsigned long deadline; 188 struct list_head timeout_list; 189 unsigned int timeout; 190 int retries; 191 192 /* 193 * completion callback. 194 */ 195 rq_end_io_fn *end_io; 196 void *end_io_data; 197 198 /* for bidi */ 199 struct request *next_rq; 200 }; 201 202 static inline unsigned short req_get_ioprio(struct request *req) 203 { 204 return req->ioprio; 205 } 206 207 #include <linux/elevator.h> 208 209 struct blk_queue_ctx; 210 211 typedef void (request_fn_proc) (struct request_queue *q); 212 typedef blk_qc_t (make_request_fn) (struct request_queue *q, struct bio *bio); 213 typedef int (prep_rq_fn) (struct request_queue *, struct request *); 214 typedef void (unprep_rq_fn) (struct request_queue *, struct request *); 215 216 struct bio_vec; 217 typedef void (softirq_done_fn)(struct request *); 218 typedef int (dma_drain_needed_fn)(struct request *); 219 typedef int (lld_busy_fn) (struct request_queue *q); 220 typedef int (bsg_job_fn) (struct bsg_job *); 221 222 enum blk_eh_timer_return { 223 BLK_EH_NOT_HANDLED, 224 BLK_EH_HANDLED, 225 BLK_EH_RESET_TIMER, 226 }; 227 228 typedef enum blk_eh_timer_return (rq_timed_out_fn)(struct request *); 229 230 enum blk_queue_state { 231 Queue_down, 232 Queue_up, 233 }; 234 235 struct blk_queue_tag { 236 struct request **tag_index; /* map of busy tags */ 237 unsigned long *tag_map; /* bit map of free/busy tags */ 238 int busy; /* current depth */ 239 int max_depth; /* what we will send to device */ 240 int real_max_depth; /* what the array can hold */ 241 atomic_t refcnt; /* map can be shared */ 242 int alloc_policy; /* tag allocation policy */ 243 int next_tag; /* next tag */ 244 }; 245 #define BLK_TAG_ALLOC_FIFO 0 /* allocate starting from 0 */ 246 #define BLK_TAG_ALLOC_RR 1 /* allocate starting from last allocated tag */ 247 248 #define BLK_SCSI_MAX_CMDS (256) 249 #define BLK_SCSI_CMD_PER_LONG (BLK_SCSI_MAX_CMDS / (sizeof(long) * 8)) 250 251 struct queue_limits { 252 unsigned long bounce_pfn; 253 unsigned long seg_boundary_mask; 254 unsigned long virt_boundary_mask; 255 256 unsigned int max_hw_sectors; 257 unsigned int chunk_sectors; 258 unsigned int max_sectors; 259 unsigned int max_segment_size; 260 unsigned int physical_block_size; 261 unsigned int alignment_offset; 262 unsigned int io_min; 263 unsigned int io_opt; 264 unsigned int max_discard_sectors; 265 unsigned int max_hw_discard_sectors; 266 unsigned int max_write_same_sectors; 267 unsigned int discard_granularity; 268 unsigned int discard_alignment; 269 270 unsigned short logical_block_size; 271 unsigned short max_segments; 272 unsigned short max_integrity_segments; 273 274 unsigned char misaligned; 275 unsigned char discard_misaligned; 276 unsigned char cluster; 277 unsigned char discard_zeroes_data; 278 unsigned char raid_partial_stripes_expensive; 279 }; 280 281 struct request_queue { 282 /* 283 * Together with queue_head for cacheline sharing 284 */ 285 struct list_head queue_head; 286 struct request *last_merge; 287 struct elevator_queue *elevator; 288 int nr_rqs[2]; /* # allocated [a]sync rqs */ 289 int nr_rqs_elvpriv; /* # allocated rqs w/ elvpriv */ 290 291 /* 292 * If blkcg is not used, @q->root_rl serves all requests. If blkcg 293 * is used, root blkg allocates from @q->root_rl and all other 294 * blkgs from their own blkg->rl. Which one to use should be 295 * determined using bio_request_list(). 296 */ 297 struct request_list root_rl; 298 299 request_fn_proc *request_fn; 300 make_request_fn *make_request_fn; 301 prep_rq_fn *prep_rq_fn; 302 unprep_rq_fn *unprep_rq_fn; 303 softirq_done_fn *softirq_done_fn; 304 rq_timed_out_fn *rq_timed_out_fn; 305 dma_drain_needed_fn *dma_drain_needed; 306 lld_busy_fn *lld_busy_fn; 307 308 struct blk_mq_ops *mq_ops; 309 310 unsigned int *mq_map; 311 312 /* sw queues */ 313 struct blk_mq_ctx __percpu *queue_ctx; 314 unsigned int nr_queues; 315 316 /* hw dispatch queues */ 317 struct blk_mq_hw_ctx **queue_hw_ctx; 318 unsigned int nr_hw_queues; 319 320 /* 321 * Dispatch queue sorting 322 */ 323 sector_t end_sector; 324 struct request *boundary_rq; 325 326 /* 327 * Delayed queue handling 328 */ 329 struct delayed_work delay_work; 330 331 struct backing_dev_info backing_dev_info; 332 333 /* 334 * The queue owner gets to use this for whatever they like. 335 * ll_rw_blk doesn't touch it. 336 */ 337 void *queuedata; 338 339 /* 340 * various queue flags, see QUEUE_* below 341 */ 342 unsigned long queue_flags; 343 344 /* 345 * ida allocated id for this queue. Used to index queues from 346 * ioctx. 347 */ 348 int id; 349 350 /* 351 * queue needs bounce pages for pages above this limit 352 */ 353 gfp_t bounce_gfp; 354 355 /* 356 * protects queue structures from reentrancy. ->__queue_lock should 357 * _never_ be used directly, it is queue private. always use 358 * ->queue_lock. 359 */ 360 spinlock_t __queue_lock; 361 spinlock_t *queue_lock; 362 363 /* 364 * queue kobject 365 */ 366 struct kobject kobj; 367 368 /* 369 * mq queue kobject 370 */ 371 struct kobject mq_kobj; 372 373 #ifdef CONFIG_BLK_DEV_INTEGRITY 374 struct blk_integrity integrity; 375 #endif /* CONFIG_BLK_DEV_INTEGRITY */ 376 377 #ifdef CONFIG_PM 378 struct device *dev; 379 int rpm_status; 380 unsigned int nr_pending; 381 #endif 382 383 /* 384 * queue settings 385 */ 386 unsigned long nr_requests; /* Max # of requests */ 387 unsigned int nr_congestion_on; 388 unsigned int nr_congestion_off; 389 unsigned int nr_batching; 390 391 unsigned int dma_drain_size; 392 void *dma_drain_buffer; 393 unsigned int dma_pad_mask; 394 unsigned int dma_alignment; 395 396 struct blk_queue_tag *queue_tags; 397 struct list_head tag_busy_list; 398 399 unsigned int nr_sorted; 400 unsigned int in_flight[2]; 401 /* 402 * Number of active block driver functions for which blk_drain_queue() 403 * must wait. Must be incremented around functions that unlock the 404 * queue_lock internally, e.g. scsi_request_fn(). 405 */ 406 unsigned int request_fn_active; 407 408 unsigned int rq_timeout; 409 struct timer_list timeout; 410 struct list_head timeout_list; 411 412 struct list_head icq_list; 413 #ifdef CONFIG_BLK_CGROUP 414 DECLARE_BITMAP (blkcg_pols, BLKCG_MAX_POLS); 415 struct blkcg_gq *root_blkg; 416 struct list_head blkg_list; 417 #endif 418 419 struct queue_limits limits; 420 421 /* 422 * sg stuff 423 */ 424 unsigned int sg_timeout; 425 unsigned int sg_reserved_size; 426 int node; 427 #ifdef CONFIG_BLK_DEV_IO_TRACE 428 struct blk_trace *blk_trace; 429 #endif 430 /* 431 * for flush operations 432 */ 433 unsigned int flush_flags; 434 unsigned int flush_not_queueable:1; 435 struct blk_flush_queue *fq; 436 437 struct list_head requeue_list; 438 spinlock_t requeue_lock; 439 struct work_struct requeue_work; 440 441 struct mutex sysfs_lock; 442 443 int bypass_depth; 444 atomic_t mq_freeze_depth; 445 446 #if defined(CONFIG_BLK_DEV_BSG) 447 bsg_job_fn *bsg_job_fn; 448 int bsg_job_size; 449 struct bsg_class_device bsg_dev; 450 #endif 451 452 #ifdef CONFIG_BLK_DEV_THROTTLING 453 /* Throttle data */ 454 struct throtl_data *td; 455 #endif 456 struct rcu_head rcu_head; 457 wait_queue_head_t mq_freeze_wq; 458 struct percpu_ref q_usage_counter; 459 struct list_head all_q_node; 460 461 struct blk_mq_tag_set *tag_set; 462 struct list_head tag_set_list; 463 struct bio_set *bio_split; 464 465 bool mq_sysfs_init_done; 466 }; 467 468 #define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */ 469 #define QUEUE_FLAG_STOPPED 2 /* queue is stopped */ 470 #define QUEUE_FLAG_SYNCFULL 3 /* read queue has been filled */ 471 #define QUEUE_FLAG_ASYNCFULL 4 /* write queue has been filled */ 472 #define QUEUE_FLAG_DYING 5 /* queue being torn down */ 473 #define QUEUE_FLAG_BYPASS 6 /* act as dumb FIFO queue */ 474 #define QUEUE_FLAG_BIDI 7 /* queue supports bidi requests */ 475 #define QUEUE_FLAG_NOMERGES 8 /* disable merge attempts */ 476 #define QUEUE_FLAG_SAME_COMP 9 /* complete on same CPU-group */ 477 #define QUEUE_FLAG_FAIL_IO 10 /* fake timeout */ 478 #define QUEUE_FLAG_STACKABLE 11 /* supports request stacking */ 479 #define QUEUE_FLAG_NONROT 12 /* non-rotational device (SSD) */ 480 #define QUEUE_FLAG_VIRT QUEUE_FLAG_NONROT /* paravirt device */ 481 #define QUEUE_FLAG_IO_STAT 13 /* do IO stats */ 482 #define QUEUE_FLAG_DISCARD 14 /* supports DISCARD */ 483 #define QUEUE_FLAG_NOXMERGES 15 /* No extended merges */ 484 #define QUEUE_FLAG_ADD_RANDOM 16 /* Contributes to random pool */ 485 #define QUEUE_FLAG_SECDISCARD 17 /* supports SECDISCARD */ 486 #define QUEUE_FLAG_SAME_FORCE 18 /* force complete on same CPU */ 487 #define QUEUE_FLAG_DEAD 19 /* queue tear-down finished */ 488 #define QUEUE_FLAG_INIT_DONE 20 /* queue is initialized */ 489 #define QUEUE_FLAG_NO_SG_MERGE 21 /* don't attempt to merge SG segments*/ 490 #define QUEUE_FLAG_POLL 22 /* IO polling enabled if set */ 491 492 #define QUEUE_FLAG_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \ 493 (1 << QUEUE_FLAG_STACKABLE) | \ 494 (1 << QUEUE_FLAG_SAME_COMP) | \ 495 (1 << QUEUE_FLAG_ADD_RANDOM)) 496 497 #define QUEUE_FLAG_MQ_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \ 498 (1 << QUEUE_FLAG_STACKABLE) | \ 499 (1 << QUEUE_FLAG_SAME_COMP)) 500 501 static inline void queue_lockdep_assert_held(struct request_queue *q) 502 { 503 if (q->queue_lock) 504 lockdep_assert_held(q->queue_lock); 505 } 506 507 static inline void queue_flag_set_unlocked(unsigned int flag, 508 struct request_queue *q) 509 { 510 __set_bit(flag, &q->queue_flags); 511 } 512 513 static inline int queue_flag_test_and_clear(unsigned int flag, 514 struct request_queue *q) 515 { 516 queue_lockdep_assert_held(q); 517 518 if (test_bit(flag, &q->queue_flags)) { 519 __clear_bit(flag, &q->queue_flags); 520 return 1; 521 } 522 523 return 0; 524 } 525 526 static inline int queue_flag_test_and_set(unsigned int flag, 527 struct request_queue *q) 528 { 529 queue_lockdep_assert_held(q); 530 531 if (!test_bit(flag, &q->queue_flags)) { 532 __set_bit(flag, &q->queue_flags); 533 return 0; 534 } 535 536 return 1; 537 } 538 539 static inline void queue_flag_set(unsigned int flag, struct request_queue *q) 540 { 541 queue_lockdep_assert_held(q); 542 __set_bit(flag, &q->queue_flags); 543 } 544 545 static inline void queue_flag_clear_unlocked(unsigned int flag, 546 struct request_queue *q) 547 { 548 __clear_bit(flag, &q->queue_flags); 549 } 550 551 static inline int queue_in_flight(struct request_queue *q) 552 { 553 return q->in_flight[0] + q->in_flight[1]; 554 } 555 556 static inline void queue_flag_clear(unsigned int flag, struct request_queue *q) 557 { 558 queue_lockdep_assert_held(q); 559 __clear_bit(flag, &q->queue_flags); 560 } 561 562 #define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags) 563 #define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags) 564 #define blk_queue_dying(q) test_bit(QUEUE_FLAG_DYING, &(q)->queue_flags) 565 #define blk_queue_dead(q) test_bit(QUEUE_FLAG_DEAD, &(q)->queue_flags) 566 #define blk_queue_bypass(q) test_bit(QUEUE_FLAG_BYPASS, &(q)->queue_flags) 567 #define blk_queue_init_done(q) test_bit(QUEUE_FLAG_INIT_DONE, &(q)->queue_flags) 568 #define blk_queue_nomerges(q) test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags) 569 #define blk_queue_noxmerges(q) \ 570 test_bit(QUEUE_FLAG_NOXMERGES, &(q)->queue_flags) 571 #define blk_queue_nonrot(q) test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags) 572 #define blk_queue_io_stat(q) test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags) 573 #define blk_queue_add_random(q) test_bit(QUEUE_FLAG_ADD_RANDOM, &(q)->queue_flags) 574 #define blk_queue_stackable(q) \ 575 test_bit(QUEUE_FLAG_STACKABLE, &(q)->queue_flags) 576 #define blk_queue_discard(q) test_bit(QUEUE_FLAG_DISCARD, &(q)->queue_flags) 577 #define blk_queue_secdiscard(q) (blk_queue_discard(q) && \ 578 test_bit(QUEUE_FLAG_SECDISCARD, &(q)->queue_flags)) 579 580 #define blk_noretry_request(rq) \ 581 ((rq)->cmd_flags & (REQ_FAILFAST_DEV|REQ_FAILFAST_TRANSPORT| \ 582 REQ_FAILFAST_DRIVER)) 583 584 #define blk_account_rq(rq) \ 585 (((rq)->cmd_flags & REQ_STARTED) && \ 586 ((rq)->cmd_type == REQ_TYPE_FS)) 587 588 #define blk_rq_cpu_valid(rq) ((rq)->cpu != -1) 589 #define blk_bidi_rq(rq) ((rq)->next_rq != NULL) 590 /* rq->queuelist of dequeued request must be list_empty() */ 591 #define blk_queued_rq(rq) (!list_empty(&(rq)->queuelist)) 592 593 #define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist) 594 595 #define rq_data_dir(rq) ((int)((rq)->cmd_flags & 1)) 596 597 /* 598 * Driver can handle struct request, if it either has an old style 599 * request_fn defined, or is blk-mq based. 600 */ 601 static inline bool queue_is_rq_based(struct request_queue *q) 602 { 603 return q->request_fn || q->mq_ops; 604 } 605 606 static inline unsigned int blk_queue_cluster(struct request_queue *q) 607 { 608 return q->limits.cluster; 609 } 610 611 /* 612 * We regard a request as sync, if either a read or a sync write 613 */ 614 static inline bool rw_is_sync(unsigned int rw_flags) 615 { 616 return !(rw_flags & REQ_WRITE) || (rw_flags & REQ_SYNC); 617 } 618 619 static inline bool rq_is_sync(struct request *rq) 620 { 621 return rw_is_sync(rq->cmd_flags); 622 } 623 624 static inline bool blk_rl_full(struct request_list *rl, bool sync) 625 { 626 unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL; 627 628 return rl->flags & flag; 629 } 630 631 static inline void blk_set_rl_full(struct request_list *rl, bool sync) 632 { 633 unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL; 634 635 rl->flags |= flag; 636 } 637 638 static inline void blk_clear_rl_full(struct request_list *rl, bool sync) 639 { 640 unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL; 641 642 rl->flags &= ~flag; 643 } 644 645 static inline bool rq_mergeable(struct request *rq) 646 { 647 if (rq->cmd_type != REQ_TYPE_FS) 648 return false; 649 650 if (rq->cmd_flags & REQ_NOMERGE_FLAGS) 651 return false; 652 653 return true; 654 } 655 656 static inline bool blk_check_merge_flags(unsigned int flags1, 657 unsigned int flags2) 658 { 659 if ((flags1 & REQ_DISCARD) != (flags2 & REQ_DISCARD)) 660 return false; 661 662 if ((flags1 & REQ_SECURE) != (flags2 & REQ_SECURE)) 663 return false; 664 665 if ((flags1 & REQ_WRITE_SAME) != (flags2 & REQ_WRITE_SAME)) 666 return false; 667 668 return true; 669 } 670 671 static inline bool blk_write_same_mergeable(struct bio *a, struct bio *b) 672 { 673 if (bio_data(a) == bio_data(b)) 674 return true; 675 676 return false; 677 } 678 679 /* 680 * q->prep_rq_fn return values 681 */ 682 #define BLKPREP_OK 0 /* serve it */ 683 #define BLKPREP_KILL 1 /* fatal error, kill */ 684 #define BLKPREP_DEFER 2 /* leave on queue */ 685 686 extern unsigned long blk_max_low_pfn, blk_max_pfn; 687 688 /* 689 * standard bounce addresses: 690 * 691 * BLK_BOUNCE_HIGH : bounce all highmem pages 692 * BLK_BOUNCE_ANY : don't bounce anything 693 * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary 694 */ 695 696 #if BITS_PER_LONG == 32 697 #define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT) 698 #else 699 #define BLK_BOUNCE_HIGH -1ULL 700 #endif 701 #define BLK_BOUNCE_ANY (-1ULL) 702 #define BLK_BOUNCE_ISA (DMA_BIT_MASK(24)) 703 704 /* 705 * default timeout for SG_IO if none specified 706 */ 707 #define BLK_DEFAULT_SG_TIMEOUT (60 * HZ) 708 #define BLK_MIN_SG_TIMEOUT (7 * HZ) 709 710 #ifdef CONFIG_BOUNCE 711 extern int init_emergency_isa_pool(void); 712 extern void blk_queue_bounce(struct request_queue *q, struct bio **bio); 713 #else 714 static inline int init_emergency_isa_pool(void) 715 { 716 return 0; 717 } 718 static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio) 719 { 720 } 721 #endif /* CONFIG_MMU */ 722 723 struct rq_map_data { 724 struct page **pages; 725 int page_order; 726 int nr_entries; 727 unsigned long offset; 728 int null_mapped; 729 int from_user; 730 }; 731 732 struct req_iterator { 733 struct bvec_iter iter; 734 struct bio *bio; 735 }; 736 737 /* This should not be used directly - use rq_for_each_segment */ 738 #define for_each_bio(_bio) \ 739 for (; _bio; _bio = _bio->bi_next) 740 #define __rq_for_each_bio(_bio, rq) \ 741 if ((rq->bio)) \ 742 for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next) 743 744 #define rq_for_each_segment(bvl, _rq, _iter) \ 745 __rq_for_each_bio(_iter.bio, _rq) \ 746 bio_for_each_segment(bvl, _iter.bio, _iter.iter) 747 748 #define rq_iter_last(bvec, _iter) \ 749 (_iter.bio->bi_next == NULL && \ 750 bio_iter_last(bvec, _iter.iter)) 751 752 #ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 753 # error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform" 754 #endif 755 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 756 extern void rq_flush_dcache_pages(struct request *rq); 757 #else 758 static inline void rq_flush_dcache_pages(struct request *rq) 759 { 760 } 761 #endif 762 763 extern int blk_register_queue(struct gendisk *disk); 764 extern void blk_unregister_queue(struct gendisk *disk); 765 extern blk_qc_t generic_make_request(struct bio *bio); 766 extern void blk_rq_init(struct request_queue *q, struct request *rq); 767 extern void blk_put_request(struct request *); 768 extern void __blk_put_request(struct request_queue *, struct request *); 769 extern struct request *blk_get_request(struct request_queue *, int, gfp_t); 770 extern struct request *blk_make_request(struct request_queue *, struct bio *, 771 gfp_t); 772 extern void blk_rq_set_block_pc(struct request *); 773 extern void blk_requeue_request(struct request_queue *, struct request *); 774 extern void blk_add_request_payload(struct request *rq, struct page *page, 775 unsigned int len); 776 extern int blk_rq_check_limits(struct request_queue *q, struct request *rq); 777 extern int blk_lld_busy(struct request_queue *q); 778 extern int blk_rq_prep_clone(struct request *rq, struct request *rq_src, 779 struct bio_set *bs, gfp_t gfp_mask, 780 int (*bio_ctr)(struct bio *, struct bio *, void *), 781 void *data); 782 extern void blk_rq_unprep_clone(struct request *rq); 783 extern int blk_insert_cloned_request(struct request_queue *q, 784 struct request *rq); 785 extern void blk_delay_queue(struct request_queue *, unsigned long); 786 extern void blk_queue_split(struct request_queue *, struct bio **, 787 struct bio_set *); 788 extern void blk_recount_segments(struct request_queue *, struct bio *); 789 extern int scsi_verify_blk_ioctl(struct block_device *, unsigned int); 790 extern int scsi_cmd_blk_ioctl(struct block_device *, fmode_t, 791 unsigned int, void __user *); 792 extern int scsi_cmd_ioctl(struct request_queue *, struct gendisk *, fmode_t, 793 unsigned int, void __user *); 794 extern int sg_scsi_ioctl(struct request_queue *, struct gendisk *, fmode_t, 795 struct scsi_ioctl_command __user *); 796 797 extern void blk_start_queue(struct request_queue *q); 798 extern void blk_stop_queue(struct request_queue *q); 799 extern void blk_sync_queue(struct request_queue *q); 800 extern void __blk_stop_queue(struct request_queue *q); 801 extern void __blk_run_queue(struct request_queue *q); 802 extern void __blk_run_queue_uncond(struct request_queue *q); 803 extern void blk_run_queue(struct request_queue *); 804 extern void blk_run_queue_async(struct request_queue *q); 805 extern int blk_rq_map_user(struct request_queue *, struct request *, 806 struct rq_map_data *, void __user *, unsigned long, 807 gfp_t); 808 extern int blk_rq_unmap_user(struct bio *); 809 extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, unsigned int, gfp_t); 810 extern int blk_rq_map_user_iov(struct request_queue *, struct request *, 811 struct rq_map_data *, const struct iov_iter *, 812 gfp_t); 813 extern int blk_execute_rq(struct request_queue *, struct gendisk *, 814 struct request *, int); 815 extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *, 816 struct request *, int, rq_end_io_fn *); 817 818 bool blk_poll(struct request_queue *q, blk_qc_t cookie); 819 820 static inline struct request_queue *bdev_get_queue(struct block_device *bdev) 821 { 822 return bdev->bd_disk->queue; /* this is never NULL */ 823 } 824 825 /* 826 * blk_rq_pos() : the current sector 827 * blk_rq_bytes() : bytes left in the entire request 828 * blk_rq_cur_bytes() : bytes left in the current segment 829 * blk_rq_err_bytes() : bytes left till the next error boundary 830 * blk_rq_sectors() : sectors left in the entire request 831 * blk_rq_cur_sectors() : sectors left in the current segment 832 */ 833 static inline sector_t blk_rq_pos(const struct request *rq) 834 { 835 return rq->__sector; 836 } 837 838 static inline unsigned int blk_rq_bytes(const struct request *rq) 839 { 840 return rq->__data_len; 841 } 842 843 static inline int blk_rq_cur_bytes(const struct request *rq) 844 { 845 return rq->bio ? bio_cur_bytes(rq->bio) : 0; 846 } 847 848 extern unsigned int blk_rq_err_bytes(const struct request *rq); 849 850 static inline unsigned int blk_rq_sectors(const struct request *rq) 851 { 852 return blk_rq_bytes(rq) >> 9; 853 } 854 855 static inline unsigned int blk_rq_cur_sectors(const struct request *rq) 856 { 857 return blk_rq_cur_bytes(rq) >> 9; 858 } 859 860 static inline unsigned int blk_queue_get_max_sectors(struct request_queue *q, 861 unsigned int cmd_flags) 862 { 863 if (unlikely(cmd_flags & REQ_DISCARD)) 864 return min(q->limits.max_discard_sectors, UINT_MAX >> 9); 865 866 if (unlikely(cmd_flags & REQ_WRITE_SAME)) 867 return q->limits.max_write_same_sectors; 868 869 return q->limits.max_sectors; 870 } 871 872 /* 873 * Return maximum size of a request at given offset. Only valid for 874 * file system requests. 875 */ 876 static inline unsigned int blk_max_size_offset(struct request_queue *q, 877 sector_t offset) 878 { 879 if (!q->limits.chunk_sectors) 880 return q->limits.max_sectors; 881 882 return q->limits.chunk_sectors - 883 (offset & (q->limits.chunk_sectors - 1)); 884 } 885 886 static inline unsigned int blk_rq_get_max_sectors(struct request *rq) 887 { 888 struct request_queue *q = rq->q; 889 890 if (unlikely(rq->cmd_type == REQ_TYPE_BLOCK_PC)) 891 return q->limits.max_hw_sectors; 892 893 if (!q->limits.chunk_sectors || (rq->cmd_flags & REQ_DISCARD)) 894 return blk_queue_get_max_sectors(q, rq->cmd_flags); 895 896 return min(blk_max_size_offset(q, blk_rq_pos(rq)), 897 blk_queue_get_max_sectors(q, rq->cmd_flags)); 898 } 899 900 static inline unsigned int blk_rq_count_bios(struct request *rq) 901 { 902 unsigned int nr_bios = 0; 903 struct bio *bio; 904 905 __rq_for_each_bio(bio, rq) 906 nr_bios++; 907 908 return nr_bios; 909 } 910 911 /* 912 * Request issue related functions. 913 */ 914 extern struct request *blk_peek_request(struct request_queue *q); 915 extern void blk_start_request(struct request *rq); 916 extern struct request *blk_fetch_request(struct request_queue *q); 917 918 /* 919 * Request completion related functions. 920 * 921 * blk_update_request() completes given number of bytes and updates 922 * the request without completing it. 923 * 924 * blk_end_request() and friends. __blk_end_request() must be called 925 * with the request queue spinlock acquired. 926 * 927 * Several drivers define their own end_request and call 928 * blk_end_request() for parts of the original function. 929 * This prevents code duplication in drivers. 930 */ 931 extern bool blk_update_request(struct request *rq, int error, 932 unsigned int nr_bytes); 933 extern void blk_finish_request(struct request *rq, int error); 934 extern bool blk_end_request(struct request *rq, int error, 935 unsigned int nr_bytes); 936 extern void blk_end_request_all(struct request *rq, int error); 937 extern bool blk_end_request_cur(struct request *rq, int error); 938 extern bool blk_end_request_err(struct request *rq, int error); 939 extern bool __blk_end_request(struct request *rq, int error, 940 unsigned int nr_bytes); 941 extern void __blk_end_request_all(struct request *rq, int error); 942 extern bool __blk_end_request_cur(struct request *rq, int error); 943 extern bool __blk_end_request_err(struct request *rq, int error); 944 945 extern void blk_complete_request(struct request *); 946 extern void __blk_complete_request(struct request *); 947 extern void blk_abort_request(struct request *); 948 extern void blk_unprep_request(struct request *); 949 950 /* 951 * Access functions for manipulating queue properties 952 */ 953 extern struct request_queue *blk_init_queue_node(request_fn_proc *rfn, 954 spinlock_t *lock, int node_id); 955 extern struct request_queue *blk_init_queue(request_fn_proc *, spinlock_t *); 956 extern struct request_queue *blk_init_allocated_queue(struct request_queue *, 957 request_fn_proc *, spinlock_t *); 958 extern void blk_cleanup_queue(struct request_queue *); 959 extern void blk_queue_make_request(struct request_queue *, make_request_fn *); 960 extern void blk_queue_bounce_limit(struct request_queue *, u64); 961 extern void blk_limits_max_hw_sectors(struct queue_limits *, unsigned int); 962 extern void blk_queue_max_hw_sectors(struct request_queue *, unsigned int); 963 extern void blk_queue_chunk_sectors(struct request_queue *, unsigned int); 964 extern void blk_queue_max_segments(struct request_queue *, unsigned short); 965 extern void blk_queue_max_segment_size(struct request_queue *, unsigned int); 966 extern void blk_queue_max_discard_sectors(struct request_queue *q, 967 unsigned int max_discard_sectors); 968 extern void blk_queue_max_write_same_sectors(struct request_queue *q, 969 unsigned int max_write_same_sectors); 970 extern void blk_queue_logical_block_size(struct request_queue *, unsigned short); 971 extern void blk_queue_physical_block_size(struct request_queue *, unsigned int); 972 extern void blk_queue_alignment_offset(struct request_queue *q, 973 unsigned int alignment); 974 extern void blk_limits_io_min(struct queue_limits *limits, unsigned int min); 975 extern void blk_queue_io_min(struct request_queue *q, unsigned int min); 976 extern void blk_limits_io_opt(struct queue_limits *limits, unsigned int opt); 977 extern void blk_queue_io_opt(struct request_queue *q, unsigned int opt); 978 extern void blk_set_default_limits(struct queue_limits *lim); 979 extern void blk_set_stacking_limits(struct queue_limits *lim); 980 extern int blk_stack_limits(struct queue_limits *t, struct queue_limits *b, 981 sector_t offset); 982 extern int bdev_stack_limits(struct queue_limits *t, struct block_device *bdev, 983 sector_t offset); 984 extern void disk_stack_limits(struct gendisk *disk, struct block_device *bdev, 985 sector_t offset); 986 extern void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b); 987 extern void blk_queue_dma_pad(struct request_queue *, unsigned int); 988 extern void blk_queue_update_dma_pad(struct request_queue *, unsigned int); 989 extern int blk_queue_dma_drain(struct request_queue *q, 990 dma_drain_needed_fn *dma_drain_needed, 991 void *buf, unsigned int size); 992 extern void blk_queue_lld_busy(struct request_queue *q, lld_busy_fn *fn); 993 extern void blk_queue_segment_boundary(struct request_queue *, unsigned long); 994 extern void blk_queue_virt_boundary(struct request_queue *, unsigned long); 995 extern void blk_queue_prep_rq(struct request_queue *, prep_rq_fn *pfn); 996 extern void blk_queue_unprep_rq(struct request_queue *, unprep_rq_fn *ufn); 997 extern void blk_queue_dma_alignment(struct request_queue *, int); 998 extern void blk_queue_update_dma_alignment(struct request_queue *, int); 999 extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *); 1000 extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *); 1001 extern void blk_queue_rq_timeout(struct request_queue *, unsigned int); 1002 extern void blk_queue_flush(struct request_queue *q, unsigned int flush); 1003 extern void blk_queue_flush_queueable(struct request_queue *q, bool queueable); 1004 extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev); 1005 1006 extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *); 1007 extern void blk_dump_rq_flags(struct request *, char *); 1008 extern long nr_blockdev_pages(void); 1009 1010 bool __must_check blk_get_queue(struct request_queue *); 1011 struct request_queue *blk_alloc_queue(gfp_t); 1012 struct request_queue *blk_alloc_queue_node(gfp_t, int); 1013 extern void blk_put_queue(struct request_queue *); 1014 extern void blk_set_queue_dying(struct request_queue *); 1015 1016 /* 1017 * block layer runtime pm functions 1018 */ 1019 #ifdef CONFIG_PM 1020 extern void blk_pm_runtime_init(struct request_queue *q, struct device *dev); 1021 extern int blk_pre_runtime_suspend(struct request_queue *q); 1022 extern void blk_post_runtime_suspend(struct request_queue *q, int err); 1023 extern void blk_pre_runtime_resume(struct request_queue *q); 1024 extern void blk_post_runtime_resume(struct request_queue *q, int err); 1025 #else 1026 static inline void blk_pm_runtime_init(struct request_queue *q, 1027 struct device *dev) {} 1028 static inline int blk_pre_runtime_suspend(struct request_queue *q) 1029 { 1030 return -ENOSYS; 1031 } 1032 static inline void blk_post_runtime_suspend(struct request_queue *q, int err) {} 1033 static inline void blk_pre_runtime_resume(struct request_queue *q) {} 1034 static inline void blk_post_runtime_resume(struct request_queue *q, int err) {} 1035 #endif 1036 1037 /* 1038 * blk_plug permits building a queue of related requests by holding the I/O 1039 * fragments for a short period. This allows merging of sequential requests 1040 * into single larger request. As the requests are moved from a per-task list to 1041 * the device's request_queue in a batch, this results in improved scalability 1042 * as the lock contention for request_queue lock is reduced. 1043 * 1044 * It is ok not to disable preemption when adding the request to the plug list 1045 * or when attempting a merge, because blk_schedule_flush_list() will only flush 1046 * the plug list when the task sleeps by itself. For details, please see 1047 * schedule() where blk_schedule_flush_plug() is called. 1048 */ 1049 struct blk_plug { 1050 struct list_head list; /* requests */ 1051 struct list_head mq_list; /* blk-mq requests */ 1052 struct list_head cb_list; /* md requires an unplug callback */ 1053 }; 1054 #define BLK_MAX_REQUEST_COUNT 16 1055 1056 struct blk_plug_cb; 1057 typedef void (*blk_plug_cb_fn)(struct blk_plug_cb *, bool); 1058 struct blk_plug_cb { 1059 struct list_head list; 1060 blk_plug_cb_fn callback; 1061 void *data; 1062 }; 1063 extern struct blk_plug_cb *blk_check_plugged(blk_plug_cb_fn unplug, 1064 void *data, int size); 1065 extern void blk_start_plug(struct blk_plug *); 1066 extern void blk_finish_plug(struct blk_plug *); 1067 extern void blk_flush_plug_list(struct blk_plug *, bool); 1068 1069 static inline void blk_flush_plug(struct task_struct *tsk) 1070 { 1071 struct blk_plug *plug = tsk->plug; 1072 1073 if (plug) 1074 blk_flush_plug_list(plug, false); 1075 } 1076 1077 static inline void blk_schedule_flush_plug(struct task_struct *tsk) 1078 { 1079 struct blk_plug *plug = tsk->plug; 1080 1081 if (plug) 1082 blk_flush_plug_list(plug, true); 1083 } 1084 1085 static inline bool blk_needs_flush_plug(struct task_struct *tsk) 1086 { 1087 struct blk_plug *plug = tsk->plug; 1088 1089 return plug && 1090 (!list_empty(&plug->list) || 1091 !list_empty(&plug->mq_list) || 1092 !list_empty(&plug->cb_list)); 1093 } 1094 1095 /* 1096 * tag stuff 1097 */ 1098 extern int blk_queue_start_tag(struct request_queue *, struct request *); 1099 extern struct request *blk_queue_find_tag(struct request_queue *, int); 1100 extern void blk_queue_end_tag(struct request_queue *, struct request *); 1101 extern int blk_queue_init_tags(struct request_queue *, int, struct blk_queue_tag *, int); 1102 extern void blk_queue_free_tags(struct request_queue *); 1103 extern int blk_queue_resize_tags(struct request_queue *, int); 1104 extern void blk_queue_invalidate_tags(struct request_queue *); 1105 extern struct blk_queue_tag *blk_init_tags(int, int); 1106 extern void blk_free_tags(struct blk_queue_tag *); 1107 1108 static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt, 1109 int tag) 1110 { 1111 if (unlikely(bqt == NULL || tag >= bqt->real_max_depth)) 1112 return NULL; 1113 return bqt->tag_index[tag]; 1114 } 1115 1116 #define BLKDEV_DISCARD_SECURE 0x01 /* secure discard */ 1117 1118 extern int blkdev_issue_flush(struct block_device *, gfp_t, sector_t *); 1119 extern int blkdev_issue_discard(struct block_device *bdev, sector_t sector, 1120 sector_t nr_sects, gfp_t gfp_mask, unsigned long flags); 1121 extern int blkdev_issue_write_same(struct block_device *bdev, sector_t sector, 1122 sector_t nr_sects, gfp_t gfp_mask, struct page *page); 1123 extern int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector, 1124 sector_t nr_sects, gfp_t gfp_mask, bool discard); 1125 static inline int sb_issue_discard(struct super_block *sb, sector_t block, 1126 sector_t nr_blocks, gfp_t gfp_mask, unsigned long flags) 1127 { 1128 return blkdev_issue_discard(sb->s_bdev, block << (sb->s_blocksize_bits - 9), 1129 nr_blocks << (sb->s_blocksize_bits - 9), 1130 gfp_mask, flags); 1131 } 1132 static inline int sb_issue_zeroout(struct super_block *sb, sector_t block, 1133 sector_t nr_blocks, gfp_t gfp_mask) 1134 { 1135 return blkdev_issue_zeroout(sb->s_bdev, 1136 block << (sb->s_blocksize_bits - 9), 1137 nr_blocks << (sb->s_blocksize_bits - 9), 1138 gfp_mask, true); 1139 } 1140 1141 extern int blk_verify_command(unsigned char *cmd, fmode_t has_write_perm); 1142 1143 enum blk_default_limits { 1144 BLK_MAX_SEGMENTS = 128, 1145 BLK_SAFE_MAX_SECTORS = 255, 1146 BLK_DEF_MAX_SECTORS = 2560, 1147 BLK_MAX_SEGMENT_SIZE = 65536, 1148 BLK_SEG_BOUNDARY_MASK = 0xFFFFFFFFUL, 1149 }; 1150 1151 #define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist) 1152 1153 static inline unsigned long queue_bounce_pfn(struct request_queue *q) 1154 { 1155 return q->limits.bounce_pfn; 1156 } 1157 1158 static inline unsigned long queue_segment_boundary(struct request_queue *q) 1159 { 1160 return q->limits.seg_boundary_mask; 1161 } 1162 1163 static inline unsigned long queue_virt_boundary(struct request_queue *q) 1164 { 1165 return q->limits.virt_boundary_mask; 1166 } 1167 1168 static inline unsigned int queue_max_sectors(struct request_queue *q) 1169 { 1170 return q->limits.max_sectors; 1171 } 1172 1173 static inline unsigned int queue_max_hw_sectors(struct request_queue *q) 1174 { 1175 return q->limits.max_hw_sectors; 1176 } 1177 1178 static inline unsigned short queue_max_segments(struct request_queue *q) 1179 { 1180 return q->limits.max_segments; 1181 } 1182 1183 static inline unsigned int queue_max_segment_size(struct request_queue *q) 1184 { 1185 return q->limits.max_segment_size; 1186 } 1187 1188 static inline unsigned short queue_logical_block_size(struct request_queue *q) 1189 { 1190 int retval = 512; 1191 1192 if (q && q->limits.logical_block_size) 1193 retval = q->limits.logical_block_size; 1194 1195 return retval; 1196 } 1197 1198 static inline unsigned short bdev_logical_block_size(struct block_device *bdev) 1199 { 1200 return queue_logical_block_size(bdev_get_queue(bdev)); 1201 } 1202 1203 static inline unsigned int queue_physical_block_size(struct request_queue *q) 1204 { 1205 return q->limits.physical_block_size; 1206 } 1207 1208 static inline unsigned int bdev_physical_block_size(struct block_device *bdev) 1209 { 1210 return queue_physical_block_size(bdev_get_queue(bdev)); 1211 } 1212 1213 static inline unsigned int queue_io_min(struct request_queue *q) 1214 { 1215 return q->limits.io_min; 1216 } 1217 1218 static inline int bdev_io_min(struct block_device *bdev) 1219 { 1220 return queue_io_min(bdev_get_queue(bdev)); 1221 } 1222 1223 static inline unsigned int queue_io_opt(struct request_queue *q) 1224 { 1225 return q->limits.io_opt; 1226 } 1227 1228 static inline int bdev_io_opt(struct block_device *bdev) 1229 { 1230 return queue_io_opt(bdev_get_queue(bdev)); 1231 } 1232 1233 static inline int queue_alignment_offset(struct request_queue *q) 1234 { 1235 if (q->limits.misaligned) 1236 return -1; 1237 1238 return q->limits.alignment_offset; 1239 } 1240 1241 static inline int queue_limit_alignment_offset(struct queue_limits *lim, sector_t sector) 1242 { 1243 unsigned int granularity = max(lim->physical_block_size, lim->io_min); 1244 unsigned int alignment = sector_div(sector, granularity >> 9) << 9; 1245 1246 return (granularity + lim->alignment_offset - alignment) % granularity; 1247 } 1248 1249 static inline int bdev_alignment_offset(struct block_device *bdev) 1250 { 1251 struct request_queue *q = bdev_get_queue(bdev); 1252 1253 if (q->limits.misaligned) 1254 return -1; 1255 1256 if (bdev != bdev->bd_contains) 1257 return bdev->bd_part->alignment_offset; 1258 1259 return q->limits.alignment_offset; 1260 } 1261 1262 static inline int queue_discard_alignment(struct request_queue *q) 1263 { 1264 if (q->limits.discard_misaligned) 1265 return -1; 1266 1267 return q->limits.discard_alignment; 1268 } 1269 1270 static inline int queue_limit_discard_alignment(struct queue_limits *lim, sector_t sector) 1271 { 1272 unsigned int alignment, granularity, offset; 1273 1274 if (!lim->max_discard_sectors) 1275 return 0; 1276 1277 /* Why are these in bytes, not sectors? */ 1278 alignment = lim->discard_alignment >> 9; 1279 granularity = lim->discard_granularity >> 9; 1280 if (!granularity) 1281 return 0; 1282 1283 /* Offset of the partition start in 'granularity' sectors */ 1284 offset = sector_div(sector, granularity); 1285 1286 /* And why do we do this modulus *again* in blkdev_issue_discard()? */ 1287 offset = (granularity + alignment - offset) % granularity; 1288 1289 /* Turn it back into bytes, gaah */ 1290 return offset << 9; 1291 } 1292 1293 static inline int bdev_discard_alignment(struct block_device *bdev) 1294 { 1295 struct request_queue *q = bdev_get_queue(bdev); 1296 1297 if (bdev != bdev->bd_contains) 1298 return bdev->bd_part->discard_alignment; 1299 1300 return q->limits.discard_alignment; 1301 } 1302 1303 static inline unsigned int queue_discard_zeroes_data(struct request_queue *q) 1304 { 1305 if (q->limits.max_discard_sectors && q->limits.discard_zeroes_data == 1) 1306 return 1; 1307 1308 return 0; 1309 } 1310 1311 static inline unsigned int bdev_discard_zeroes_data(struct block_device *bdev) 1312 { 1313 return queue_discard_zeroes_data(bdev_get_queue(bdev)); 1314 } 1315 1316 static inline unsigned int bdev_write_same(struct block_device *bdev) 1317 { 1318 struct request_queue *q = bdev_get_queue(bdev); 1319 1320 if (q) 1321 return q->limits.max_write_same_sectors; 1322 1323 return 0; 1324 } 1325 1326 static inline int queue_dma_alignment(struct request_queue *q) 1327 { 1328 return q ? q->dma_alignment : 511; 1329 } 1330 1331 static inline int blk_rq_aligned(struct request_queue *q, unsigned long addr, 1332 unsigned int len) 1333 { 1334 unsigned int alignment = queue_dma_alignment(q) | q->dma_pad_mask; 1335 return !(addr & alignment) && !(len & alignment); 1336 } 1337 1338 /* assumes size > 256 */ 1339 static inline unsigned int blksize_bits(unsigned int size) 1340 { 1341 unsigned int bits = 8; 1342 do { 1343 bits++; 1344 size >>= 1; 1345 } while (size > 256); 1346 return bits; 1347 } 1348 1349 static inline unsigned int block_size(struct block_device *bdev) 1350 { 1351 return bdev->bd_block_size; 1352 } 1353 1354 static inline bool queue_flush_queueable(struct request_queue *q) 1355 { 1356 return !q->flush_not_queueable; 1357 } 1358 1359 typedef struct {struct page *v;} Sector; 1360 1361 unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *); 1362 1363 static inline void put_dev_sector(Sector p) 1364 { 1365 page_cache_release(p.v); 1366 } 1367 1368 /* 1369 * Check if adding a bio_vec after bprv with offset would create a gap in 1370 * the SG list. Most drivers don't care about this, but some do. 1371 */ 1372 static inline bool bvec_gap_to_prev(struct request_queue *q, 1373 struct bio_vec *bprv, unsigned int offset) 1374 { 1375 if (!queue_virt_boundary(q)) 1376 return false; 1377 return offset || 1378 ((bprv->bv_offset + bprv->bv_len) & queue_virt_boundary(q)); 1379 } 1380 1381 static inline bool bio_will_gap(struct request_queue *q, struct bio *prev, 1382 struct bio *next) 1383 { 1384 if (!bio_has_data(prev)) 1385 return false; 1386 1387 return bvec_gap_to_prev(q, &prev->bi_io_vec[prev->bi_vcnt - 1], 1388 next->bi_io_vec[0].bv_offset); 1389 } 1390 1391 static inline bool req_gap_back_merge(struct request *req, struct bio *bio) 1392 { 1393 return bio_will_gap(req->q, req->biotail, bio); 1394 } 1395 1396 static inline bool req_gap_front_merge(struct request *req, struct bio *bio) 1397 { 1398 return bio_will_gap(req->q, bio, req->bio); 1399 } 1400 1401 struct work_struct; 1402 int kblockd_schedule_work(struct work_struct *work); 1403 int kblockd_schedule_delayed_work(struct delayed_work *dwork, unsigned long delay); 1404 int kblockd_schedule_delayed_work_on(int cpu, struct delayed_work *dwork, unsigned long delay); 1405 1406 #ifdef CONFIG_BLK_CGROUP 1407 /* 1408 * This should not be using sched_clock(). A real patch is in progress 1409 * to fix this up, until that is in place we need to disable preemption 1410 * around sched_clock() in this function and set_io_start_time_ns(). 1411 */ 1412 static inline void set_start_time_ns(struct request *req) 1413 { 1414 preempt_disable(); 1415 req->start_time_ns = sched_clock(); 1416 preempt_enable(); 1417 } 1418 1419 static inline void set_io_start_time_ns(struct request *req) 1420 { 1421 preempt_disable(); 1422 req->io_start_time_ns = sched_clock(); 1423 preempt_enable(); 1424 } 1425 1426 static inline uint64_t rq_start_time_ns(struct request *req) 1427 { 1428 return req->start_time_ns; 1429 } 1430 1431 static inline uint64_t rq_io_start_time_ns(struct request *req) 1432 { 1433 return req->io_start_time_ns; 1434 } 1435 #else 1436 static inline void set_start_time_ns(struct request *req) {} 1437 static inline void set_io_start_time_ns(struct request *req) {} 1438 static inline uint64_t rq_start_time_ns(struct request *req) 1439 { 1440 return 0; 1441 } 1442 static inline uint64_t rq_io_start_time_ns(struct request *req) 1443 { 1444 return 0; 1445 } 1446 #endif 1447 1448 #define MODULE_ALIAS_BLOCKDEV(major,minor) \ 1449 MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor)) 1450 #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \ 1451 MODULE_ALIAS("block-major-" __stringify(major) "-*") 1452 1453 #if defined(CONFIG_BLK_DEV_INTEGRITY) 1454 1455 enum blk_integrity_flags { 1456 BLK_INTEGRITY_VERIFY = 1 << 0, 1457 BLK_INTEGRITY_GENERATE = 1 << 1, 1458 BLK_INTEGRITY_DEVICE_CAPABLE = 1 << 2, 1459 BLK_INTEGRITY_IP_CHECKSUM = 1 << 3, 1460 }; 1461 1462 struct blk_integrity_iter { 1463 void *prot_buf; 1464 void *data_buf; 1465 sector_t seed; 1466 unsigned int data_size; 1467 unsigned short interval; 1468 const char *disk_name; 1469 }; 1470 1471 typedef int (integrity_processing_fn) (struct blk_integrity_iter *); 1472 1473 struct blk_integrity_profile { 1474 integrity_processing_fn *generate_fn; 1475 integrity_processing_fn *verify_fn; 1476 const char *name; 1477 }; 1478 1479 extern void blk_integrity_register(struct gendisk *, struct blk_integrity *); 1480 extern void blk_integrity_unregister(struct gendisk *); 1481 extern int blk_integrity_compare(struct gendisk *, struct gendisk *); 1482 extern int blk_rq_map_integrity_sg(struct request_queue *, struct bio *, 1483 struct scatterlist *); 1484 extern int blk_rq_count_integrity_sg(struct request_queue *, struct bio *); 1485 extern bool blk_integrity_merge_rq(struct request_queue *, struct request *, 1486 struct request *); 1487 extern bool blk_integrity_merge_bio(struct request_queue *, struct request *, 1488 struct bio *); 1489 1490 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk) 1491 { 1492 struct blk_integrity *bi = &disk->queue->integrity; 1493 1494 if (!bi->profile) 1495 return NULL; 1496 1497 return bi; 1498 } 1499 1500 static inline 1501 struct blk_integrity *bdev_get_integrity(struct block_device *bdev) 1502 { 1503 return blk_get_integrity(bdev->bd_disk); 1504 } 1505 1506 static inline bool blk_integrity_rq(struct request *rq) 1507 { 1508 return rq->cmd_flags & REQ_INTEGRITY; 1509 } 1510 1511 static inline void blk_queue_max_integrity_segments(struct request_queue *q, 1512 unsigned int segs) 1513 { 1514 q->limits.max_integrity_segments = segs; 1515 } 1516 1517 static inline unsigned short 1518 queue_max_integrity_segments(struct request_queue *q) 1519 { 1520 return q->limits.max_integrity_segments; 1521 } 1522 1523 static inline bool integrity_req_gap_back_merge(struct request *req, 1524 struct bio *next) 1525 { 1526 struct bio_integrity_payload *bip = bio_integrity(req->bio); 1527 struct bio_integrity_payload *bip_next = bio_integrity(next); 1528 1529 return bvec_gap_to_prev(req->q, &bip->bip_vec[bip->bip_vcnt - 1], 1530 bip_next->bip_vec[0].bv_offset); 1531 } 1532 1533 static inline bool integrity_req_gap_front_merge(struct request *req, 1534 struct bio *bio) 1535 { 1536 struct bio_integrity_payload *bip = bio_integrity(bio); 1537 struct bio_integrity_payload *bip_next = bio_integrity(req->bio); 1538 1539 return bvec_gap_to_prev(req->q, &bip->bip_vec[bip->bip_vcnt - 1], 1540 bip_next->bip_vec[0].bv_offset); 1541 } 1542 1543 #else /* CONFIG_BLK_DEV_INTEGRITY */ 1544 1545 struct bio; 1546 struct block_device; 1547 struct gendisk; 1548 struct blk_integrity; 1549 1550 static inline int blk_integrity_rq(struct request *rq) 1551 { 1552 return 0; 1553 } 1554 static inline int blk_rq_count_integrity_sg(struct request_queue *q, 1555 struct bio *b) 1556 { 1557 return 0; 1558 } 1559 static inline int blk_rq_map_integrity_sg(struct request_queue *q, 1560 struct bio *b, 1561 struct scatterlist *s) 1562 { 1563 return 0; 1564 } 1565 static inline struct blk_integrity *bdev_get_integrity(struct block_device *b) 1566 { 1567 return NULL; 1568 } 1569 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk) 1570 { 1571 return NULL; 1572 } 1573 static inline int blk_integrity_compare(struct gendisk *a, struct gendisk *b) 1574 { 1575 return 0; 1576 } 1577 static inline void blk_integrity_register(struct gendisk *d, 1578 struct blk_integrity *b) 1579 { 1580 } 1581 static inline void blk_integrity_unregister(struct gendisk *d) 1582 { 1583 } 1584 static inline void blk_queue_max_integrity_segments(struct request_queue *q, 1585 unsigned int segs) 1586 { 1587 } 1588 static inline unsigned short queue_max_integrity_segments(struct request_queue *q) 1589 { 1590 return 0; 1591 } 1592 static inline bool blk_integrity_merge_rq(struct request_queue *rq, 1593 struct request *r1, 1594 struct request *r2) 1595 { 1596 return true; 1597 } 1598 static inline bool blk_integrity_merge_bio(struct request_queue *rq, 1599 struct request *r, 1600 struct bio *b) 1601 { 1602 return true; 1603 } 1604 1605 static inline bool integrity_req_gap_back_merge(struct request *req, 1606 struct bio *next) 1607 { 1608 return false; 1609 } 1610 static inline bool integrity_req_gap_front_merge(struct request *req, 1611 struct bio *bio) 1612 { 1613 return false; 1614 } 1615 1616 #endif /* CONFIG_BLK_DEV_INTEGRITY */ 1617 1618 struct block_device_operations { 1619 int (*open) (struct block_device *, fmode_t); 1620 void (*release) (struct gendisk *, fmode_t); 1621 int (*rw_page)(struct block_device *, sector_t, struct page *, int rw); 1622 int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long); 1623 int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long); 1624 long (*direct_access)(struct block_device *, sector_t, void __pmem **, 1625 unsigned long *pfn); 1626 unsigned int (*check_events) (struct gendisk *disk, 1627 unsigned int clearing); 1628 /* ->media_changed() is DEPRECATED, use ->check_events() instead */ 1629 int (*media_changed) (struct gendisk *); 1630 void (*unlock_native_capacity) (struct gendisk *); 1631 int (*revalidate_disk) (struct gendisk *); 1632 int (*getgeo)(struct block_device *, struct hd_geometry *); 1633 /* this callback is with swap_lock and sometimes page table lock held */ 1634 void (*swap_slot_free_notify) (struct block_device *, unsigned long); 1635 struct module *owner; 1636 const struct pr_ops *pr_ops; 1637 }; 1638 1639 extern int __blkdev_driver_ioctl(struct block_device *, fmode_t, unsigned int, 1640 unsigned long); 1641 extern int bdev_read_page(struct block_device *, sector_t, struct page *); 1642 extern int bdev_write_page(struct block_device *, sector_t, struct page *, 1643 struct writeback_control *); 1644 extern long bdev_direct_access(struct block_device *, sector_t, 1645 void __pmem **addr, unsigned long *pfn, long size); 1646 #else /* CONFIG_BLOCK */ 1647 1648 struct block_device; 1649 1650 /* 1651 * stubs for when the block layer is configured out 1652 */ 1653 #define buffer_heads_over_limit 0 1654 1655 static inline long nr_blockdev_pages(void) 1656 { 1657 return 0; 1658 } 1659 1660 struct blk_plug { 1661 }; 1662 1663 static inline void blk_start_plug(struct blk_plug *plug) 1664 { 1665 } 1666 1667 static inline void blk_finish_plug(struct blk_plug *plug) 1668 { 1669 } 1670 1671 static inline void blk_flush_plug(struct task_struct *task) 1672 { 1673 } 1674 1675 static inline void blk_schedule_flush_plug(struct task_struct *task) 1676 { 1677 } 1678 1679 1680 static inline bool blk_needs_flush_plug(struct task_struct *tsk) 1681 { 1682 return false; 1683 } 1684 1685 static inline int blkdev_issue_flush(struct block_device *bdev, gfp_t gfp_mask, 1686 sector_t *error_sector) 1687 { 1688 return 0; 1689 } 1690 1691 #endif /* CONFIG_BLOCK */ 1692 1693 #endif 1694