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/pfn.h> 19 #include <linux/bio.h> 20 #include <linux/stringify.h> 21 #include <linux/gfp.h> 22 #include <linux/bsg.h> 23 #include <linux/smp.h> 24 #include <linux/rcupdate.h> 25 #include <linux/percpu-refcount.h> 26 #include <linux/scatterlist.h> 27 28 struct module; 29 struct scsi_ioctl_command; 30 31 struct request_queue; 32 struct elevator_queue; 33 struct blk_trace; 34 struct request; 35 struct sg_io_hdr; 36 struct bsg_job; 37 struct blkcg_gq; 38 struct blk_flush_queue; 39 struct pr_ops; 40 41 #define BLKDEV_MIN_RQ 4 42 #define BLKDEV_MAX_RQ 128 /* Default maximum */ 43 44 /* 45 * Maximum number of blkcg policies allowed to be registered concurrently. 46 * Defined here to simplify include dependency. 47 */ 48 #define BLKCG_MAX_POLS 2 49 50 struct request; 51 typedef void (rq_end_io_fn)(struct request *, int); 52 53 #define BLK_RL_SYNCFULL (1U << 0) 54 #define BLK_RL_ASYNCFULL (1U << 1) 55 56 struct request_list { 57 struct request_queue *q; /* the queue this rl belongs to */ 58 #ifdef CONFIG_BLK_CGROUP 59 struct blkcg_gq *blkg; /* blkg this request pool belongs to */ 60 #endif 61 /* 62 * count[], starved[], and wait[] are indexed by 63 * BLK_RW_SYNC/BLK_RW_ASYNC 64 */ 65 int count[2]; 66 int starved[2]; 67 mempool_t *rq_pool; 68 wait_queue_head_t wait[2]; 69 unsigned int flags; 70 }; 71 72 /* 73 * request command types 74 */ 75 enum rq_cmd_type_bits { 76 REQ_TYPE_FS = 1, /* fs request */ 77 REQ_TYPE_BLOCK_PC, /* scsi command */ 78 REQ_TYPE_DRV_PRIV, /* driver defined types from here */ 79 }; 80 81 #define BLK_MAX_CDB 16 82 83 /* 84 * Try to put the fields that are referenced together in the same cacheline. 85 * 86 * If you modify this structure, make sure to update blk_rq_init() and 87 * especially blk_mq_rq_ctx_init() to take care of the added fields. 88 */ 89 struct request { 90 struct list_head queuelist; 91 union { 92 struct call_single_data csd; 93 unsigned long fifo_time; 94 }; 95 96 struct request_queue *q; 97 struct blk_mq_ctx *mq_ctx; 98 99 u64 cmd_flags; 100 unsigned cmd_type; 101 unsigned long atomic_flags; 102 103 int cpu; 104 105 /* the following two fields are internal, NEVER access directly */ 106 unsigned int __data_len; /* total data len */ 107 sector_t __sector; /* sector cursor */ 108 109 struct bio *bio; 110 struct bio *biotail; 111 112 /* 113 * The hash is used inside the scheduler, and killed once the 114 * request reaches the dispatch list. The ipi_list is only used 115 * to queue the request for softirq completion, which is long 116 * after the request has been unhashed (and even removed from 117 * the dispatch list). 118 */ 119 union { 120 struct hlist_node hash; /* merge hash */ 121 struct list_head ipi_list; 122 }; 123 124 /* 125 * The rb_node is only used inside the io scheduler, requests 126 * are pruned when moved to the dispatch queue. So let the 127 * completion_data share space with the rb_node. 128 */ 129 union { 130 struct rb_node rb_node; /* sort/lookup */ 131 void *completion_data; 132 }; 133 134 /* 135 * Three pointers are available for the IO schedulers, if they need 136 * more they have to dynamically allocate it. Flush requests are 137 * never put on the IO scheduler. So let the flush fields share 138 * space with the elevator data. 139 */ 140 union { 141 struct { 142 struct io_cq *icq; 143 void *priv[2]; 144 } elv; 145 146 struct { 147 unsigned int seq; 148 struct list_head list; 149 rq_end_io_fn *saved_end_io; 150 } flush; 151 }; 152 153 struct gendisk *rq_disk; 154 struct hd_struct *part; 155 unsigned long start_time; 156 #ifdef CONFIG_BLK_CGROUP 157 struct request_list *rl; /* rl this rq is alloced from */ 158 unsigned long long start_time_ns; 159 unsigned long long io_start_time_ns; /* when passed to hardware */ 160 #endif 161 /* Number of scatter-gather DMA addr+len pairs after 162 * physical address coalescing is performed. 163 */ 164 unsigned short nr_phys_segments; 165 #if defined(CONFIG_BLK_DEV_INTEGRITY) 166 unsigned short nr_integrity_segments; 167 #endif 168 169 unsigned short ioprio; 170 171 void *special; /* opaque pointer available for LLD use */ 172 173 int tag; 174 int errors; 175 176 /* 177 * when request is used as a packet command carrier 178 */ 179 unsigned char __cmd[BLK_MAX_CDB]; 180 unsigned char *cmd; 181 unsigned short cmd_len; 182 183 unsigned int extra_len; /* length of alignment and padding */ 184 unsigned int sense_len; 185 unsigned int resid_len; /* residual count */ 186 void *sense; 187 188 unsigned long deadline; 189 struct list_head timeout_list; 190 unsigned int timeout; 191 int retries; 192 193 /* 194 * completion callback. 195 */ 196 rq_end_io_fn *end_io; 197 void *end_io_data; 198 199 /* for bidi */ 200 struct request *next_rq; 201 }; 202 203 static inline unsigned short req_get_ioprio(struct request *req) 204 { 205 return req->ioprio; 206 } 207 208 #include <linux/elevator.h> 209 210 struct blk_queue_ctx; 211 212 typedef void (request_fn_proc) (struct request_queue *q); 213 typedef blk_qc_t (make_request_fn) (struct request_queue *q, struct bio *bio); 214 typedef int (prep_rq_fn) (struct request_queue *, struct request *); 215 typedef void (unprep_rq_fn) (struct request_queue *, struct request *); 216 217 struct bio_vec; 218 typedef void (softirq_done_fn)(struct request *); 219 typedef int (dma_drain_needed_fn)(struct request *); 220 typedef int (lld_busy_fn) (struct request_queue *q); 221 typedef int (bsg_job_fn) (struct bsg_job *); 222 223 enum blk_eh_timer_return { 224 BLK_EH_NOT_HANDLED, 225 BLK_EH_HANDLED, 226 BLK_EH_RESET_TIMER, 227 }; 228 229 typedef enum blk_eh_timer_return (rq_timed_out_fn)(struct request *); 230 231 enum blk_queue_state { 232 Queue_down, 233 Queue_up, 234 }; 235 236 struct blk_queue_tag { 237 struct request **tag_index; /* map of busy tags */ 238 unsigned long *tag_map; /* bit map of free/busy tags */ 239 int busy; /* current depth */ 240 int max_depth; /* what we will send to device */ 241 int real_max_depth; /* what the array can hold */ 242 atomic_t refcnt; /* map can be shared */ 243 int alloc_policy; /* tag allocation policy */ 244 int next_tag; /* next tag */ 245 }; 246 #define BLK_TAG_ALLOC_FIFO 0 /* allocate starting from 0 */ 247 #define BLK_TAG_ALLOC_RR 1 /* allocate starting from last allocated tag */ 248 249 #define BLK_SCSI_MAX_CMDS (256) 250 #define BLK_SCSI_CMD_PER_LONG (BLK_SCSI_MAX_CMDS / (sizeof(long) * 8)) 251 252 struct queue_limits { 253 unsigned long bounce_pfn; 254 unsigned long seg_boundary_mask; 255 unsigned long virt_boundary_mask; 256 257 unsigned int max_hw_sectors; 258 unsigned int max_dev_sectors; 259 unsigned int chunk_sectors; 260 unsigned int max_sectors; 261 unsigned int max_segment_size; 262 unsigned int physical_block_size; 263 unsigned int alignment_offset; 264 unsigned int io_min; 265 unsigned int io_opt; 266 unsigned int max_discard_sectors; 267 unsigned int max_hw_discard_sectors; 268 unsigned int max_write_same_sectors; 269 unsigned int discard_granularity; 270 unsigned int discard_alignment; 271 272 unsigned short logical_block_size; 273 unsigned short max_segments; 274 unsigned short max_integrity_segments; 275 276 unsigned char misaligned; 277 unsigned char discard_misaligned; 278 unsigned char cluster; 279 unsigned char discard_zeroes_data; 280 unsigned char raid_partial_stripes_expensive; 281 }; 282 283 struct request_queue { 284 /* 285 * Together with queue_head for cacheline sharing 286 */ 287 struct list_head queue_head; 288 struct request *last_merge; 289 struct elevator_queue *elevator; 290 int nr_rqs[2]; /* # allocated [a]sync rqs */ 291 int nr_rqs_elvpriv; /* # allocated rqs w/ elvpriv */ 292 293 /* 294 * If blkcg is not used, @q->root_rl serves all requests. If blkcg 295 * is used, root blkg allocates from @q->root_rl and all other 296 * blkgs from their own blkg->rl. Which one to use should be 297 * determined using bio_request_list(). 298 */ 299 struct request_list root_rl; 300 301 request_fn_proc *request_fn; 302 make_request_fn *make_request_fn; 303 prep_rq_fn *prep_rq_fn; 304 unprep_rq_fn *unprep_rq_fn; 305 softirq_done_fn *softirq_done_fn; 306 rq_timed_out_fn *rq_timed_out_fn; 307 dma_drain_needed_fn *dma_drain_needed; 308 lld_busy_fn *lld_busy_fn; 309 310 struct blk_mq_ops *mq_ops; 311 312 unsigned int *mq_map; 313 314 /* sw queues */ 315 struct blk_mq_ctx __percpu *queue_ctx; 316 unsigned int nr_queues; 317 318 /* hw dispatch queues */ 319 struct blk_mq_hw_ctx **queue_hw_ctx; 320 unsigned int nr_hw_queues; 321 322 /* 323 * Dispatch queue sorting 324 */ 325 sector_t end_sector; 326 struct request *boundary_rq; 327 328 /* 329 * Delayed queue handling 330 */ 331 struct delayed_work delay_work; 332 333 struct backing_dev_info backing_dev_info; 334 335 /* 336 * The queue owner gets to use this for whatever they like. 337 * ll_rw_blk doesn't touch it. 338 */ 339 void *queuedata; 340 341 /* 342 * various queue flags, see QUEUE_* below 343 */ 344 unsigned long queue_flags; 345 346 /* 347 * ida allocated id for this queue. Used to index queues from 348 * ioctx. 349 */ 350 int id; 351 352 /* 353 * queue needs bounce pages for pages above this limit 354 */ 355 gfp_t bounce_gfp; 356 357 /* 358 * protects queue structures from reentrancy. ->__queue_lock should 359 * _never_ be used directly, it is queue private. always use 360 * ->queue_lock. 361 */ 362 spinlock_t __queue_lock; 363 spinlock_t *queue_lock; 364 365 /* 366 * queue kobject 367 */ 368 struct kobject kobj; 369 370 /* 371 * mq queue kobject 372 */ 373 struct kobject mq_kobj; 374 375 #ifdef CONFIG_BLK_DEV_INTEGRITY 376 struct blk_integrity integrity; 377 #endif /* CONFIG_BLK_DEV_INTEGRITY */ 378 379 #ifdef CONFIG_PM 380 struct device *dev; 381 int rpm_status; 382 unsigned int nr_pending; 383 #endif 384 385 /* 386 * queue settings 387 */ 388 unsigned long nr_requests; /* Max # of requests */ 389 unsigned int nr_congestion_on; 390 unsigned int nr_congestion_off; 391 unsigned int nr_batching; 392 393 unsigned int dma_drain_size; 394 void *dma_drain_buffer; 395 unsigned int dma_pad_mask; 396 unsigned int dma_alignment; 397 398 struct blk_queue_tag *queue_tags; 399 struct list_head tag_busy_list; 400 401 unsigned int nr_sorted; 402 unsigned int in_flight[2]; 403 /* 404 * Number of active block driver functions for which blk_drain_queue() 405 * must wait. Must be incremented around functions that unlock the 406 * queue_lock internally, e.g. scsi_request_fn(). 407 */ 408 unsigned int request_fn_active; 409 410 unsigned int rq_timeout; 411 struct timer_list timeout; 412 struct work_struct timeout_work; 413 struct list_head timeout_list; 414 415 struct list_head icq_list; 416 #ifdef CONFIG_BLK_CGROUP 417 DECLARE_BITMAP (blkcg_pols, BLKCG_MAX_POLS); 418 struct blkcg_gq *root_blkg; 419 struct list_head blkg_list; 420 #endif 421 422 struct queue_limits limits; 423 424 /* 425 * sg stuff 426 */ 427 unsigned int sg_timeout; 428 unsigned int sg_reserved_size; 429 int node; 430 #ifdef CONFIG_BLK_DEV_IO_TRACE 431 struct blk_trace *blk_trace; 432 #endif 433 /* 434 * for flush operations 435 */ 436 struct blk_flush_queue *fq; 437 438 struct list_head requeue_list; 439 spinlock_t requeue_lock; 440 struct work_struct requeue_work; 441 442 struct mutex sysfs_lock; 443 444 int bypass_depth; 445 atomic_t mq_freeze_depth; 446 447 #if defined(CONFIG_BLK_DEV_BSG) 448 bsg_job_fn *bsg_job_fn; 449 int bsg_job_size; 450 struct bsg_class_device bsg_dev; 451 #endif 452 453 #ifdef CONFIG_BLK_DEV_THROTTLING 454 /* Throttle data */ 455 struct throtl_data *td; 456 #endif 457 struct rcu_head rcu_head; 458 wait_queue_head_t mq_freeze_wq; 459 struct percpu_ref q_usage_counter; 460 struct list_head all_q_node; 461 462 struct blk_mq_tag_set *tag_set; 463 struct list_head tag_set_list; 464 struct bio_set *bio_split; 465 466 bool mq_sysfs_init_done; 467 }; 468 469 #define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */ 470 #define QUEUE_FLAG_STOPPED 2 /* queue is stopped */ 471 #define QUEUE_FLAG_SYNCFULL 3 /* read queue has been filled */ 472 #define QUEUE_FLAG_ASYNCFULL 4 /* write queue has been filled */ 473 #define QUEUE_FLAG_DYING 5 /* queue being torn down */ 474 #define QUEUE_FLAG_BYPASS 6 /* act as dumb FIFO queue */ 475 #define QUEUE_FLAG_BIDI 7 /* queue supports bidi requests */ 476 #define QUEUE_FLAG_NOMERGES 8 /* disable merge attempts */ 477 #define QUEUE_FLAG_SAME_COMP 9 /* complete on same CPU-group */ 478 #define QUEUE_FLAG_FAIL_IO 10 /* fake timeout */ 479 #define QUEUE_FLAG_STACKABLE 11 /* supports request stacking */ 480 #define QUEUE_FLAG_NONROT 12 /* non-rotational device (SSD) */ 481 #define QUEUE_FLAG_VIRT QUEUE_FLAG_NONROT /* paravirt device */ 482 #define QUEUE_FLAG_IO_STAT 13 /* do IO stats */ 483 #define QUEUE_FLAG_DISCARD 14 /* supports DISCARD */ 484 #define QUEUE_FLAG_NOXMERGES 15 /* No extended merges */ 485 #define QUEUE_FLAG_ADD_RANDOM 16 /* Contributes to random pool */ 486 #define QUEUE_FLAG_SECDISCARD 17 /* supports SECDISCARD */ 487 #define QUEUE_FLAG_SAME_FORCE 18 /* force complete on same CPU */ 488 #define QUEUE_FLAG_DEAD 19 /* queue tear-down finished */ 489 #define QUEUE_FLAG_INIT_DONE 20 /* queue is initialized */ 490 #define QUEUE_FLAG_NO_SG_MERGE 21 /* don't attempt to merge SG segments*/ 491 #define QUEUE_FLAG_POLL 22 /* IO polling enabled if set */ 492 #define QUEUE_FLAG_WC 23 /* Write back caching */ 493 #define QUEUE_FLAG_FUA 24 /* device supports FUA writes */ 494 #define QUEUE_FLAG_FLUSH_NQ 25 /* flush not queueuable */ 495 496 #define QUEUE_FLAG_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \ 497 (1 << QUEUE_FLAG_STACKABLE) | \ 498 (1 << QUEUE_FLAG_SAME_COMP) | \ 499 (1 << QUEUE_FLAG_ADD_RANDOM)) 500 501 #define QUEUE_FLAG_MQ_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \ 502 (1 << QUEUE_FLAG_STACKABLE) | \ 503 (1 << QUEUE_FLAG_SAME_COMP) | \ 504 (1 << QUEUE_FLAG_POLL)) 505 506 static inline void queue_lockdep_assert_held(struct request_queue *q) 507 { 508 if (q->queue_lock) 509 lockdep_assert_held(q->queue_lock); 510 } 511 512 static inline void queue_flag_set_unlocked(unsigned int flag, 513 struct request_queue *q) 514 { 515 __set_bit(flag, &q->queue_flags); 516 } 517 518 static inline int queue_flag_test_and_clear(unsigned int flag, 519 struct request_queue *q) 520 { 521 queue_lockdep_assert_held(q); 522 523 if (test_bit(flag, &q->queue_flags)) { 524 __clear_bit(flag, &q->queue_flags); 525 return 1; 526 } 527 528 return 0; 529 } 530 531 static inline int queue_flag_test_and_set(unsigned int flag, 532 struct request_queue *q) 533 { 534 queue_lockdep_assert_held(q); 535 536 if (!test_bit(flag, &q->queue_flags)) { 537 __set_bit(flag, &q->queue_flags); 538 return 0; 539 } 540 541 return 1; 542 } 543 544 static inline void queue_flag_set(unsigned int flag, struct request_queue *q) 545 { 546 queue_lockdep_assert_held(q); 547 __set_bit(flag, &q->queue_flags); 548 } 549 550 static inline void queue_flag_clear_unlocked(unsigned int flag, 551 struct request_queue *q) 552 { 553 __clear_bit(flag, &q->queue_flags); 554 } 555 556 static inline int queue_in_flight(struct request_queue *q) 557 { 558 return q->in_flight[0] + q->in_flight[1]; 559 } 560 561 static inline void queue_flag_clear(unsigned int flag, struct request_queue *q) 562 { 563 queue_lockdep_assert_held(q); 564 __clear_bit(flag, &q->queue_flags); 565 } 566 567 #define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags) 568 #define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags) 569 #define blk_queue_dying(q) test_bit(QUEUE_FLAG_DYING, &(q)->queue_flags) 570 #define blk_queue_dead(q) test_bit(QUEUE_FLAG_DEAD, &(q)->queue_flags) 571 #define blk_queue_bypass(q) test_bit(QUEUE_FLAG_BYPASS, &(q)->queue_flags) 572 #define blk_queue_init_done(q) test_bit(QUEUE_FLAG_INIT_DONE, &(q)->queue_flags) 573 #define blk_queue_nomerges(q) test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags) 574 #define blk_queue_noxmerges(q) \ 575 test_bit(QUEUE_FLAG_NOXMERGES, &(q)->queue_flags) 576 #define blk_queue_nonrot(q) test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags) 577 #define blk_queue_io_stat(q) test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags) 578 #define blk_queue_add_random(q) test_bit(QUEUE_FLAG_ADD_RANDOM, &(q)->queue_flags) 579 #define blk_queue_stackable(q) \ 580 test_bit(QUEUE_FLAG_STACKABLE, &(q)->queue_flags) 581 #define blk_queue_discard(q) test_bit(QUEUE_FLAG_DISCARD, &(q)->queue_flags) 582 #define blk_queue_secdiscard(q) (blk_queue_discard(q) && \ 583 test_bit(QUEUE_FLAG_SECDISCARD, &(q)->queue_flags)) 584 585 #define blk_noretry_request(rq) \ 586 ((rq)->cmd_flags & (REQ_FAILFAST_DEV|REQ_FAILFAST_TRANSPORT| \ 587 REQ_FAILFAST_DRIVER)) 588 589 #define blk_account_rq(rq) \ 590 (((rq)->cmd_flags & REQ_STARTED) && \ 591 ((rq)->cmd_type == REQ_TYPE_FS)) 592 593 #define blk_rq_cpu_valid(rq) ((rq)->cpu != -1) 594 #define blk_bidi_rq(rq) ((rq)->next_rq != NULL) 595 /* rq->queuelist of dequeued request must be list_empty() */ 596 #define blk_queued_rq(rq) (!list_empty(&(rq)->queuelist)) 597 598 #define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist) 599 600 #define rq_data_dir(rq) ((int)((rq)->cmd_flags & 1)) 601 602 /* 603 * Driver can handle struct request, if it either has an old style 604 * request_fn defined, or is blk-mq based. 605 */ 606 static inline bool queue_is_rq_based(struct request_queue *q) 607 { 608 return q->request_fn || q->mq_ops; 609 } 610 611 static inline unsigned int blk_queue_cluster(struct request_queue *q) 612 { 613 return q->limits.cluster; 614 } 615 616 /* 617 * We regard a request as sync, if either a read or a sync write 618 */ 619 static inline bool rw_is_sync(unsigned int rw_flags) 620 { 621 return !(rw_flags & REQ_WRITE) || (rw_flags & REQ_SYNC); 622 } 623 624 static inline bool rq_is_sync(struct request *rq) 625 { 626 return rw_is_sync(rq->cmd_flags); 627 } 628 629 static inline bool blk_rl_full(struct request_list *rl, bool sync) 630 { 631 unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL; 632 633 return rl->flags & flag; 634 } 635 636 static inline void blk_set_rl_full(struct request_list *rl, bool sync) 637 { 638 unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL; 639 640 rl->flags |= flag; 641 } 642 643 static inline void blk_clear_rl_full(struct request_list *rl, bool sync) 644 { 645 unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL; 646 647 rl->flags &= ~flag; 648 } 649 650 static inline bool rq_mergeable(struct request *rq) 651 { 652 if (rq->cmd_type != REQ_TYPE_FS) 653 return false; 654 655 if (rq->cmd_flags & REQ_NOMERGE_FLAGS) 656 return false; 657 658 return true; 659 } 660 661 static inline bool blk_check_merge_flags(unsigned int flags1, 662 unsigned int flags2) 663 { 664 if ((flags1 & REQ_DISCARD) != (flags2 & REQ_DISCARD)) 665 return false; 666 667 if ((flags1 & REQ_SECURE) != (flags2 & REQ_SECURE)) 668 return false; 669 670 if ((flags1 & REQ_WRITE_SAME) != (flags2 & REQ_WRITE_SAME)) 671 return false; 672 673 return true; 674 } 675 676 static inline bool blk_write_same_mergeable(struct bio *a, struct bio *b) 677 { 678 if (bio_data(a) == bio_data(b)) 679 return true; 680 681 return false; 682 } 683 684 /* 685 * q->prep_rq_fn return values 686 */ 687 enum { 688 BLKPREP_OK, /* serve it */ 689 BLKPREP_KILL, /* fatal error, kill, return -EIO */ 690 BLKPREP_DEFER, /* leave on queue */ 691 BLKPREP_INVALID, /* invalid command, kill, return -EREMOTEIO */ 692 }; 693 694 extern unsigned long blk_max_low_pfn, blk_max_pfn; 695 696 /* 697 * standard bounce addresses: 698 * 699 * BLK_BOUNCE_HIGH : bounce all highmem pages 700 * BLK_BOUNCE_ANY : don't bounce anything 701 * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary 702 */ 703 704 #if BITS_PER_LONG == 32 705 #define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT) 706 #else 707 #define BLK_BOUNCE_HIGH -1ULL 708 #endif 709 #define BLK_BOUNCE_ANY (-1ULL) 710 #define BLK_BOUNCE_ISA (DMA_BIT_MASK(24)) 711 712 /* 713 * default timeout for SG_IO if none specified 714 */ 715 #define BLK_DEFAULT_SG_TIMEOUT (60 * HZ) 716 #define BLK_MIN_SG_TIMEOUT (7 * HZ) 717 718 #ifdef CONFIG_BOUNCE 719 extern int init_emergency_isa_pool(void); 720 extern void blk_queue_bounce(struct request_queue *q, struct bio **bio); 721 #else 722 static inline int init_emergency_isa_pool(void) 723 { 724 return 0; 725 } 726 static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio) 727 { 728 } 729 #endif /* CONFIG_MMU */ 730 731 struct rq_map_data { 732 struct page **pages; 733 int page_order; 734 int nr_entries; 735 unsigned long offset; 736 int null_mapped; 737 int from_user; 738 }; 739 740 struct req_iterator { 741 struct bvec_iter iter; 742 struct bio *bio; 743 }; 744 745 /* This should not be used directly - use rq_for_each_segment */ 746 #define for_each_bio(_bio) \ 747 for (; _bio; _bio = _bio->bi_next) 748 #define __rq_for_each_bio(_bio, rq) \ 749 if ((rq->bio)) \ 750 for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next) 751 752 #define rq_for_each_segment(bvl, _rq, _iter) \ 753 __rq_for_each_bio(_iter.bio, _rq) \ 754 bio_for_each_segment(bvl, _iter.bio, _iter.iter) 755 756 #define rq_iter_last(bvec, _iter) \ 757 (_iter.bio->bi_next == NULL && \ 758 bio_iter_last(bvec, _iter.iter)) 759 760 #ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 761 # error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform" 762 #endif 763 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 764 extern void rq_flush_dcache_pages(struct request *rq); 765 #else 766 static inline void rq_flush_dcache_pages(struct request *rq) 767 { 768 } 769 #endif 770 771 extern int blk_register_queue(struct gendisk *disk); 772 extern void blk_unregister_queue(struct gendisk *disk); 773 extern blk_qc_t generic_make_request(struct bio *bio); 774 extern void blk_rq_init(struct request_queue *q, struct request *rq); 775 extern void blk_put_request(struct request *); 776 extern void __blk_put_request(struct request_queue *, struct request *); 777 extern struct request *blk_get_request(struct request_queue *, int, gfp_t); 778 extern struct request *blk_make_request(struct request_queue *, struct bio *, 779 gfp_t); 780 extern void blk_rq_set_block_pc(struct request *); 781 extern void blk_requeue_request(struct request_queue *, struct request *); 782 extern void blk_add_request_payload(struct request *rq, struct page *page, 783 int offset, unsigned int len); 784 extern int blk_lld_busy(struct request_queue *q); 785 extern int blk_rq_prep_clone(struct request *rq, struct request *rq_src, 786 struct bio_set *bs, gfp_t gfp_mask, 787 int (*bio_ctr)(struct bio *, struct bio *, void *), 788 void *data); 789 extern void blk_rq_unprep_clone(struct request *rq); 790 extern int blk_insert_cloned_request(struct request_queue *q, 791 struct request *rq); 792 extern void blk_delay_queue(struct request_queue *, unsigned long); 793 extern void blk_queue_split(struct request_queue *, struct bio **, 794 struct bio_set *); 795 extern void blk_recount_segments(struct request_queue *, struct bio *); 796 extern int scsi_verify_blk_ioctl(struct block_device *, unsigned int); 797 extern int scsi_cmd_blk_ioctl(struct block_device *, fmode_t, 798 unsigned int, void __user *); 799 extern int scsi_cmd_ioctl(struct request_queue *, struct gendisk *, fmode_t, 800 unsigned int, void __user *); 801 extern int sg_scsi_ioctl(struct request_queue *, struct gendisk *, fmode_t, 802 struct scsi_ioctl_command __user *); 803 804 extern int blk_queue_enter(struct request_queue *q, bool nowait); 805 extern void blk_queue_exit(struct request_queue *q); 806 extern void blk_start_queue(struct request_queue *q); 807 extern void blk_start_queue_async(struct request_queue *q); 808 extern void blk_stop_queue(struct request_queue *q); 809 extern void blk_sync_queue(struct request_queue *q); 810 extern void __blk_stop_queue(struct request_queue *q); 811 extern void __blk_run_queue(struct request_queue *q); 812 extern void __blk_run_queue_uncond(struct request_queue *q); 813 extern void blk_run_queue(struct request_queue *); 814 extern void blk_run_queue_async(struct request_queue *q); 815 extern int blk_rq_map_user(struct request_queue *, struct request *, 816 struct rq_map_data *, void __user *, unsigned long, 817 gfp_t); 818 extern int blk_rq_unmap_user(struct bio *); 819 extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, unsigned int, gfp_t); 820 extern int blk_rq_map_user_iov(struct request_queue *, struct request *, 821 struct rq_map_data *, const struct iov_iter *, 822 gfp_t); 823 extern int blk_execute_rq(struct request_queue *, struct gendisk *, 824 struct request *, int); 825 extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *, 826 struct request *, int, rq_end_io_fn *); 827 828 bool blk_poll(struct request_queue *q, blk_qc_t cookie); 829 830 static inline struct request_queue *bdev_get_queue(struct block_device *bdev) 831 { 832 return bdev->bd_disk->queue; /* this is never NULL */ 833 } 834 835 /* 836 * blk_rq_pos() : the current sector 837 * blk_rq_bytes() : bytes left in the entire request 838 * blk_rq_cur_bytes() : bytes left in the current segment 839 * blk_rq_err_bytes() : bytes left till the next error boundary 840 * blk_rq_sectors() : sectors left in the entire request 841 * blk_rq_cur_sectors() : sectors left in the current segment 842 */ 843 static inline sector_t blk_rq_pos(const struct request *rq) 844 { 845 return rq->__sector; 846 } 847 848 static inline unsigned int blk_rq_bytes(const struct request *rq) 849 { 850 return rq->__data_len; 851 } 852 853 static inline int blk_rq_cur_bytes(const struct request *rq) 854 { 855 return rq->bio ? bio_cur_bytes(rq->bio) : 0; 856 } 857 858 extern unsigned int blk_rq_err_bytes(const struct request *rq); 859 860 static inline unsigned int blk_rq_sectors(const struct request *rq) 861 { 862 return blk_rq_bytes(rq) >> 9; 863 } 864 865 static inline unsigned int blk_rq_cur_sectors(const struct request *rq) 866 { 867 return blk_rq_cur_bytes(rq) >> 9; 868 } 869 870 static inline unsigned int blk_queue_get_max_sectors(struct request_queue *q, 871 unsigned int cmd_flags) 872 { 873 if (unlikely(cmd_flags & REQ_DISCARD)) 874 return min(q->limits.max_discard_sectors, UINT_MAX >> 9); 875 876 if (unlikely(cmd_flags & REQ_WRITE_SAME)) 877 return q->limits.max_write_same_sectors; 878 879 return q->limits.max_sectors; 880 } 881 882 /* 883 * Return maximum size of a request at given offset. Only valid for 884 * file system requests. 885 */ 886 static inline unsigned int blk_max_size_offset(struct request_queue *q, 887 sector_t offset) 888 { 889 if (!q->limits.chunk_sectors) 890 return q->limits.max_sectors; 891 892 return q->limits.chunk_sectors - 893 (offset & (q->limits.chunk_sectors - 1)); 894 } 895 896 static inline unsigned int blk_rq_get_max_sectors(struct request *rq) 897 { 898 struct request_queue *q = rq->q; 899 900 if (unlikely(rq->cmd_type != REQ_TYPE_FS)) 901 return q->limits.max_hw_sectors; 902 903 if (!q->limits.chunk_sectors || (rq->cmd_flags & REQ_DISCARD)) 904 return blk_queue_get_max_sectors(q, rq->cmd_flags); 905 906 return min(blk_max_size_offset(q, blk_rq_pos(rq)), 907 blk_queue_get_max_sectors(q, rq->cmd_flags)); 908 } 909 910 static inline unsigned int blk_rq_count_bios(struct request *rq) 911 { 912 unsigned int nr_bios = 0; 913 struct bio *bio; 914 915 __rq_for_each_bio(bio, rq) 916 nr_bios++; 917 918 return nr_bios; 919 } 920 921 /* 922 * Request issue related functions. 923 */ 924 extern struct request *blk_peek_request(struct request_queue *q); 925 extern void blk_start_request(struct request *rq); 926 extern struct request *blk_fetch_request(struct request_queue *q); 927 928 /* 929 * Request completion related functions. 930 * 931 * blk_update_request() completes given number of bytes and updates 932 * the request without completing it. 933 * 934 * blk_end_request() and friends. __blk_end_request() must be called 935 * with the request queue spinlock acquired. 936 * 937 * Several drivers define their own end_request and call 938 * blk_end_request() for parts of the original function. 939 * This prevents code duplication in drivers. 940 */ 941 extern bool blk_update_request(struct request *rq, int error, 942 unsigned int nr_bytes); 943 extern void blk_finish_request(struct request *rq, int error); 944 extern bool blk_end_request(struct request *rq, int error, 945 unsigned int nr_bytes); 946 extern void blk_end_request_all(struct request *rq, int error); 947 extern bool blk_end_request_cur(struct request *rq, int error); 948 extern bool blk_end_request_err(struct request *rq, int error); 949 extern bool __blk_end_request(struct request *rq, int error, 950 unsigned int nr_bytes); 951 extern void __blk_end_request_all(struct request *rq, int error); 952 extern bool __blk_end_request_cur(struct request *rq, int error); 953 extern bool __blk_end_request_err(struct request *rq, int error); 954 955 extern void blk_complete_request(struct request *); 956 extern void __blk_complete_request(struct request *); 957 extern void blk_abort_request(struct request *); 958 extern void blk_unprep_request(struct request *); 959 960 /* 961 * Access functions for manipulating queue properties 962 */ 963 extern struct request_queue *blk_init_queue_node(request_fn_proc *rfn, 964 spinlock_t *lock, int node_id); 965 extern struct request_queue *blk_init_queue(request_fn_proc *, spinlock_t *); 966 extern struct request_queue *blk_init_allocated_queue(struct request_queue *, 967 request_fn_proc *, spinlock_t *); 968 extern void blk_cleanup_queue(struct request_queue *); 969 extern void blk_queue_make_request(struct request_queue *, make_request_fn *); 970 extern void blk_queue_bounce_limit(struct request_queue *, u64); 971 extern void blk_queue_max_hw_sectors(struct request_queue *, unsigned int); 972 extern void blk_queue_chunk_sectors(struct request_queue *, unsigned int); 973 extern void blk_queue_max_segments(struct request_queue *, unsigned short); 974 extern void blk_queue_max_segment_size(struct request_queue *, unsigned int); 975 extern void blk_queue_max_discard_sectors(struct request_queue *q, 976 unsigned int max_discard_sectors); 977 extern void blk_queue_max_write_same_sectors(struct request_queue *q, 978 unsigned int max_write_same_sectors); 979 extern void blk_queue_logical_block_size(struct request_queue *, unsigned short); 980 extern void blk_queue_physical_block_size(struct request_queue *, unsigned int); 981 extern void blk_queue_alignment_offset(struct request_queue *q, 982 unsigned int alignment); 983 extern void blk_limits_io_min(struct queue_limits *limits, unsigned int min); 984 extern void blk_queue_io_min(struct request_queue *q, unsigned int min); 985 extern void blk_limits_io_opt(struct queue_limits *limits, unsigned int opt); 986 extern void blk_queue_io_opt(struct request_queue *q, unsigned int opt); 987 extern void blk_set_default_limits(struct queue_limits *lim); 988 extern void blk_set_stacking_limits(struct queue_limits *lim); 989 extern int blk_stack_limits(struct queue_limits *t, struct queue_limits *b, 990 sector_t offset); 991 extern int bdev_stack_limits(struct queue_limits *t, struct block_device *bdev, 992 sector_t offset); 993 extern void disk_stack_limits(struct gendisk *disk, struct block_device *bdev, 994 sector_t offset); 995 extern void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b); 996 extern void blk_queue_dma_pad(struct request_queue *, unsigned int); 997 extern void blk_queue_update_dma_pad(struct request_queue *, unsigned int); 998 extern int blk_queue_dma_drain(struct request_queue *q, 999 dma_drain_needed_fn *dma_drain_needed, 1000 void *buf, unsigned int size); 1001 extern void blk_queue_lld_busy(struct request_queue *q, lld_busy_fn *fn); 1002 extern void blk_queue_segment_boundary(struct request_queue *, unsigned long); 1003 extern void blk_queue_virt_boundary(struct request_queue *, unsigned long); 1004 extern void blk_queue_prep_rq(struct request_queue *, prep_rq_fn *pfn); 1005 extern void blk_queue_unprep_rq(struct request_queue *, unprep_rq_fn *ufn); 1006 extern void blk_queue_dma_alignment(struct request_queue *, int); 1007 extern void blk_queue_update_dma_alignment(struct request_queue *, int); 1008 extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *); 1009 extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *); 1010 extern void blk_queue_rq_timeout(struct request_queue *, unsigned int); 1011 extern void blk_queue_flush_queueable(struct request_queue *q, bool queueable); 1012 extern void blk_queue_write_cache(struct request_queue *q, bool enabled, bool fua); 1013 extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev); 1014 1015 extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *); 1016 extern void blk_dump_rq_flags(struct request *, char *); 1017 extern long nr_blockdev_pages(void); 1018 1019 bool __must_check blk_get_queue(struct request_queue *); 1020 struct request_queue *blk_alloc_queue(gfp_t); 1021 struct request_queue *blk_alloc_queue_node(gfp_t, int); 1022 extern void blk_put_queue(struct request_queue *); 1023 extern void blk_set_queue_dying(struct request_queue *); 1024 1025 /* 1026 * block layer runtime pm functions 1027 */ 1028 #ifdef CONFIG_PM 1029 extern void blk_pm_runtime_init(struct request_queue *q, struct device *dev); 1030 extern int blk_pre_runtime_suspend(struct request_queue *q); 1031 extern void blk_post_runtime_suspend(struct request_queue *q, int err); 1032 extern void blk_pre_runtime_resume(struct request_queue *q); 1033 extern void blk_post_runtime_resume(struct request_queue *q, int err); 1034 extern void blk_set_runtime_active(struct request_queue *q); 1035 #else 1036 static inline void blk_pm_runtime_init(struct request_queue *q, 1037 struct device *dev) {} 1038 static inline int blk_pre_runtime_suspend(struct request_queue *q) 1039 { 1040 return -ENOSYS; 1041 } 1042 static inline void blk_post_runtime_suspend(struct request_queue *q, int err) {} 1043 static inline void blk_pre_runtime_resume(struct request_queue *q) {} 1044 static inline void blk_post_runtime_resume(struct request_queue *q, int err) {} 1045 extern inline void blk_set_runtime_active(struct request_queue *q) {} 1046 #endif 1047 1048 /* 1049 * blk_plug permits building a queue of related requests by holding the I/O 1050 * fragments for a short period. This allows merging of sequential requests 1051 * into single larger request. As the requests are moved from a per-task list to 1052 * the device's request_queue in a batch, this results in improved scalability 1053 * as the lock contention for request_queue lock is reduced. 1054 * 1055 * It is ok not to disable preemption when adding the request to the plug list 1056 * or when attempting a merge, because blk_schedule_flush_list() will only flush 1057 * the plug list when the task sleeps by itself. For details, please see 1058 * schedule() where blk_schedule_flush_plug() is called. 1059 */ 1060 struct blk_plug { 1061 struct list_head list; /* requests */ 1062 struct list_head mq_list; /* blk-mq requests */ 1063 struct list_head cb_list; /* md requires an unplug callback */ 1064 }; 1065 #define BLK_MAX_REQUEST_COUNT 16 1066 1067 struct blk_plug_cb; 1068 typedef void (*blk_plug_cb_fn)(struct blk_plug_cb *, bool); 1069 struct blk_plug_cb { 1070 struct list_head list; 1071 blk_plug_cb_fn callback; 1072 void *data; 1073 }; 1074 extern struct blk_plug_cb *blk_check_plugged(blk_plug_cb_fn unplug, 1075 void *data, int size); 1076 extern void blk_start_plug(struct blk_plug *); 1077 extern void blk_finish_plug(struct blk_plug *); 1078 extern void blk_flush_plug_list(struct blk_plug *, bool); 1079 1080 static inline void blk_flush_plug(struct task_struct *tsk) 1081 { 1082 struct blk_plug *plug = tsk->plug; 1083 1084 if (plug) 1085 blk_flush_plug_list(plug, false); 1086 } 1087 1088 static inline void blk_schedule_flush_plug(struct task_struct *tsk) 1089 { 1090 struct blk_plug *plug = tsk->plug; 1091 1092 if (plug) 1093 blk_flush_plug_list(plug, true); 1094 } 1095 1096 static inline bool blk_needs_flush_plug(struct task_struct *tsk) 1097 { 1098 struct blk_plug *plug = tsk->plug; 1099 1100 return plug && 1101 (!list_empty(&plug->list) || 1102 !list_empty(&plug->mq_list) || 1103 !list_empty(&plug->cb_list)); 1104 } 1105 1106 /* 1107 * tag stuff 1108 */ 1109 extern int blk_queue_start_tag(struct request_queue *, struct request *); 1110 extern struct request *blk_queue_find_tag(struct request_queue *, int); 1111 extern void blk_queue_end_tag(struct request_queue *, struct request *); 1112 extern int blk_queue_init_tags(struct request_queue *, int, struct blk_queue_tag *, int); 1113 extern void blk_queue_free_tags(struct request_queue *); 1114 extern int blk_queue_resize_tags(struct request_queue *, int); 1115 extern void blk_queue_invalidate_tags(struct request_queue *); 1116 extern struct blk_queue_tag *blk_init_tags(int, int); 1117 extern void blk_free_tags(struct blk_queue_tag *); 1118 1119 static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt, 1120 int tag) 1121 { 1122 if (unlikely(bqt == NULL || tag >= bqt->real_max_depth)) 1123 return NULL; 1124 return bqt->tag_index[tag]; 1125 } 1126 1127 #define BLKDEV_DISCARD_SECURE 0x01 /* secure discard */ 1128 1129 extern int blkdev_issue_flush(struct block_device *, gfp_t, sector_t *); 1130 extern int blkdev_issue_discard(struct block_device *bdev, sector_t sector, 1131 sector_t nr_sects, gfp_t gfp_mask, unsigned long flags); 1132 extern int __blkdev_issue_discard(struct block_device *bdev, sector_t sector, 1133 sector_t nr_sects, gfp_t gfp_mask, int type, struct bio **biop); 1134 extern int blkdev_issue_write_same(struct block_device *bdev, sector_t sector, 1135 sector_t nr_sects, gfp_t gfp_mask, struct page *page); 1136 extern int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector, 1137 sector_t nr_sects, gfp_t gfp_mask, bool discard); 1138 static inline int sb_issue_discard(struct super_block *sb, sector_t block, 1139 sector_t nr_blocks, gfp_t gfp_mask, unsigned long flags) 1140 { 1141 return blkdev_issue_discard(sb->s_bdev, block << (sb->s_blocksize_bits - 9), 1142 nr_blocks << (sb->s_blocksize_bits - 9), 1143 gfp_mask, flags); 1144 } 1145 static inline int sb_issue_zeroout(struct super_block *sb, sector_t block, 1146 sector_t nr_blocks, gfp_t gfp_mask) 1147 { 1148 return blkdev_issue_zeroout(sb->s_bdev, 1149 block << (sb->s_blocksize_bits - 9), 1150 nr_blocks << (sb->s_blocksize_bits - 9), 1151 gfp_mask, true); 1152 } 1153 1154 extern int blk_verify_command(unsigned char *cmd, fmode_t has_write_perm); 1155 1156 enum blk_default_limits { 1157 BLK_MAX_SEGMENTS = 128, 1158 BLK_SAFE_MAX_SECTORS = 255, 1159 BLK_DEF_MAX_SECTORS = 2560, 1160 BLK_MAX_SEGMENT_SIZE = 65536, 1161 BLK_SEG_BOUNDARY_MASK = 0xFFFFFFFFUL, 1162 }; 1163 1164 #define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist) 1165 1166 static inline unsigned long queue_bounce_pfn(struct request_queue *q) 1167 { 1168 return q->limits.bounce_pfn; 1169 } 1170 1171 static inline unsigned long queue_segment_boundary(struct request_queue *q) 1172 { 1173 return q->limits.seg_boundary_mask; 1174 } 1175 1176 static inline unsigned long queue_virt_boundary(struct request_queue *q) 1177 { 1178 return q->limits.virt_boundary_mask; 1179 } 1180 1181 static inline unsigned int queue_max_sectors(struct request_queue *q) 1182 { 1183 return q->limits.max_sectors; 1184 } 1185 1186 static inline unsigned int queue_max_hw_sectors(struct request_queue *q) 1187 { 1188 return q->limits.max_hw_sectors; 1189 } 1190 1191 static inline unsigned short queue_max_segments(struct request_queue *q) 1192 { 1193 return q->limits.max_segments; 1194 } 1195 1196 static inline unsigned int queue_max_segment_size(struct request_queue *q) 1197 { 1198 return q->limits.max_segment_size; 1199 } 1200 1201 static inline unsigned short queue_logical_block_size(struct request_queue *q) 1202 { 1203 int retval = 512; 1204 1205 if (q && q->limits.logical_block_size) 1206 retval = q->limits.logical_block_size; 1207 1208 return retval; 1209 } 1210 1211 static inline unsigned short bdev_logical_block_size(struct block_device *bdev) 1212 { 1213 return queue_logical_block_size(bdev_get_queue(bdev)); 1214 } 1215 1216 static inline unsigned int queue_physical_block_size(struct request_queue *q) 1217 { 1218 return q->limits.physical_block_size; 1219 } 1220 1221 static inline unsigned int bdev_physical_block_size(struct block_device *bdev) 1222 { 1223 return queue_physical_block_size(bdev_get_queue(bdev)); 1224 } 1225 1226 static inline unsigned int queue_io_min(struct request_queue *q) 1227 { 1228 return q->limits.io_min; 1229 } 1230 1231 static inline int bdev_io_min(struct block_device *bdev) 1232 { 1233 return queue_io_min(bdev_get_queue(bdev)); 1234 } 1235 1236 static inline unsigned int queue_io_opt(struct request_queue *q) 1237 { 1238 return q->limits.io_opt; 1239 } 1240 1241 static inline int bdev_io_opt(struct block_device *bdev) 1242 { 1243 return queue_io_opt(bdev_get_queue(bdev)); 1244 } 1245 1246 static inline int queue_alignment_offset(struct request_queue *q) 1247 { 1248 if (q->limits.misaligned) 1249 return -1; 1250 1251 return q->limits.alignment_offset; 1252 } 1253 1254 static inline int queue_limit_alignment_offset(struct queue_limits *lim, sector_t sector) 1255 { 1256 unsigned int granularity = max(lim->physical_block_size, lim->io_min); 1257 unsigned int alignment = sector_div(sector, granularity >> 9) << 9; 1258 1259 return (granularity + lim->alignment_offset - alignment) % granularity; 1260 } 1261 1262 static inline int bdev_alignment_offset(struct block_device *bdev) 1263 { 1264 struct request_queue *q = bdev_get_queue(bdev); 1265 1266 if (q->limits.misaligned) 1267 return -1; 1268 1269 if (bdev != bdev->bd_contains) 1270 return bdev->bd_part->alignment_offset; 1271 1272 return q->limits.alignment_offset; 1273 } 1274 1275 static inline int queue_discard_alignment(struct request_queue *q) 1276 { 1277 if (q->limits.discard_misaligned) 1278 return -1; 1279 1280 return q->limits.discard_alignment; 1281 } 1282 1283 static inline int queue_limit_discard_alignment(struct queue_limits *lim, sector_t sector) 1284 { 1285 unsigned int alignment, granularity, offset; 1286 1287 if (!lim->max_discard_sectors) 1288 return 0; 1289 1290 /* Why are these in bytes, not sectors? */ 1291 alignment = lim->discard_alignment >> 9; 1292 granularity = lim->discard_granularity >> 9; 1293 if (!granularity) 1294 return 0; 1295 1296 /* Offset of the partition start in 'granularity' sectors */ 1297 offset = sector_div(sector, granularity); 1298 1299 /* And why do we do this modulus *again* in blkdev_issue_discard()? */ 1300 offset = (granularity + alignment - offset) % granularity; 1301 1302 /* Turn it back into bytes, gaah */ 1303 return offset << 9; 1304 } 1305 1306 static inline int bdev_discard_alignment(struct block_device *bdev) 1307 { 1308 struct request_queue *q = bdev_get_queue(bdev); 1309 1310 if (bdev != bdev->bd_contains) 1311 return bdev->bd_part->discard_alignment; 1312 1313 return q->limits.discard_alignment; 1314 } 1315 1316 static inline unsigned int queue_discard_zeroes_data(struct request_queue *q) 1317 { 1318 if (q->limits.max_discard_sectors && q->limits.discard_zeroes_data == 1) 1319 return 1; 1320 1321 return 0; 1322 } 1323 1324 static inline unsigned int bdev_discard_zeroes_data(struct block_device *bdev) 1325 { 1326 return queue_discard_zeroes_data(bdev_get_queue(bdev)); 1327 } 1328 1329 static inline unsigned int bdev_write_same(struct block_device *bdev) 1330 { 1331 struct request_queue *q = bdev_get_queue(bdev); 1332 1333 if (q) 1334 return q->limits.max_write_same_sectors; 1335 1336 return 0; 1337 } 1338 1339 static inline int queue_dma_alignment(struct request_queue *q) 1340 { 1341 return q ? q->dma_alignment : 511; 1342 } 1343 1344 static inline int blk_rq_aligned(struct request_queue *q, unsigned long addr, 1345 unsigned int len) 1346 { 1347 unsigned int alignment = queue_dma_alignment(q) | q->dma_pad_mask; 1348 return !(addr & alignment) && !(len & alignment); 1349 } 1350 1351 /* assumes size > 256 */ 1352 static inline unsigned int blksize_bits(unsigned int size) 1353 { 1354 unsigned int bits = 8; 1355 do { 1356 bits++; 1357 size >>= 1; 1358 } while (size > 256); 1359 return bits; 1360 } 1361 1362 static inline unsigned int block_size(struct block_device *bdev) 1363 { 1364 return bdev->bd_block_size; 1365 } 1366 1367 static inline bool queue_flush_queueable(struct request_queue *q) 1368 { 1369 return !test_bit(QUEUE_FLAG_FLUSH_NQ, &q->queue_flags); 1370 } 1371 1372 typedef struct {struct page *v;} Sector; 1373 1374 unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *); 1375 1376 static inline void put_dev_sector(Sector p) 1377 { 1378 put_page(p.v); 1379 } 1380 1381 static inline bool __bvec_gap_to_prev(struct request_queue *q, 1382 struct bio_vec *bprv, unsigned int offset) 1383 { 1384 return offset || 1385 ((bprv->bv_offset + bprv->bv_len) & queue_virt_boundary(q)); 1386 } 1387 1388 /* 1389 * Check if adding a bio_vec after bprv with offset would create a gap in 1390 * the SG list. Most drivers don't care about this, but some do. 1391 */ 1392 static inline bool bvec_gap_to_prev(struct request_queue *q, 1393 struct bio_vec *bprv, unsigned int offset) 1394 { 1395 if (!queue_virt_boundary(q)) 1396 return false; 1397 return __bvec_gap_to_prev(q, bprv, offset); 1398 } 1399 1400 static inline bool bio_will_gap(struct request_queue *q, struct bio *prev, 1401 struct bio *next) 1402 { 1403 if (bio_has_data(prev) && queue_virt_boundary(q)) { 1404 struct bio_vec pb, nb; 1405 1406 bio_get_last_bvec(prev, &pb); 1407 bio_get_first_bvec(next, &nb); 1408 1409 return __bvec_gap_to_prev(q, &pb, nb.bv_offset); 1410 } 1411 1412 return false; 1413 } 1414 1415 static inline bool req_gap_back_merge(struct request *req, struct bio *bio) 1416 { 1417 return bio_will_gap(req->q, req->biotail, bio); 1418 } 1419 1420 static inline bool req_gap_front_merge(struct request *req, struct bio *bio) 1421 { 1422 return bio_will_gap(req->q, bio, req->bio); 1423 } 1424 1425 struct work_struct; 1426 int kblockd_schedule_work(struct work_struct *work); 1427 int kblockd_schedule_delayed_work(struct delayed_work *dwork, unsigned long delay); 1428 int kblockd_schedule_delayed_work_on(int cpu, struct delayed_work *dwork, unsigned long delay); 1429 1430 #ifdef CONFIG_BLK_CGROUP 1431 /* 1432 * This should not be using sched_clock(). A real patch is in progress 1433 * to fix this up, until that is in place we need to disable preemption 1434 * around sched_clock() in this function and set_io_start_time_ns(). 1435 */ 1436 static inline void set_start_time_ns(struct request *req) 1437 { 1438 preempt_disable(); 1439 req->start_time_ns = sched_clock(); 1440 preempt_enable(); 1441 } 1442 1443 static inline void set_io_start_time_ns(struct request *req) 1444 { 1445 preempt_disable(); 1446 req->io_start_time_ns = sched_clock(); 1447 preempt_enable(); 1448 } 1449 1450 static inline uint64_t rq_start_time_ns(struct request *req) 1451 { 1452 return req->start_time_ns; 1453 } 1454 1455 static inline uint64_t rq_io_start_time_ns(struct request *req) 1456 { 1457 return req->io_start_time_ns; 1458 } 1459 #else 1460 static inline void set_start_time_ns(struct request *req) {} 1461 static inline void set_io_start_time_ns(struct request *req) {} 1462 static inline uint64_t rq_start_time_ns(struct request *req) 1463 { 1464 return 0; 1465 } 1466 static inline uint64_t rq_io_start_time_ns(struct request *req) 1467 { 1468 return 0; 1469 } 1470 #endif 1471 1472 #define MODULE_ALIAS_BLOCKDEV(major,minor) \ 1473 MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor)) 1474 #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \ 1475 MODULE_ALIAS("block-major-" __stringify(major) "-*") 1476 1477 #if defined(CONFIG_BLK_DEV_INTEGRITY) 1478 1479 enum blk_integrity_flags { 1480 BLK_INTEGRITY_VERIFY = 1 << 0, 1481 BLK_INTEGRITY_GENERATE = 1 << 1, 1482 BLK_INTEGRITY_DEVICE_CAPABLE = 1 << 2, 1483 BLK_INTEGRITY_IP_CHECKSUM = 1 << 3, 1484 }; 1485 1486 struct blk_integrity_iter { 1487 void *prot_buf; 1488 void *data_buf; 1489 sector_t seed; 1490 unsigned int data_size; 1491 unsigned short interval; 1492 const char *disk_name; 1493 }; 1494 1495 typedef int (integrity_processing_fn) (struct blk_integrity_iter *); 1496 1497 struct blk_integrity_profile { 1498 integrity_processing_fn *generate_fn; 1499 integrity_processing_fn *verify_fn; 1500 const char *name; 1501 }; 1502 1503 extern void blk_integrity_register(struct gendisk *, struct blk_integrity *); 1504 extern void blk_integrity_unregister(struct gendisk *); 1505 extern int blk_integrity_compare(struct gendisk *, struct gendisk *); 1506 extern int blk_rq_map_integrity_sg(struct request_queue *, struct bio *, 1507 struct scatterlist *); 1508 extern int blk_rq_count_integrity_sg(struct request_queue *, struct bio *); 1509 extern bool blk_integrity_merge_rq(struct request_queue *, struct request *, 1510 struct request *); 1511 extern bool blk_integrity_merge_bio(struct request_queue *, struct request *, 1512 struct bio *); 1513 1514 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk) 1515 { 1516 struct blk_integrity *bi = &disk->queue->integrity; 1517 1518 if (!bi->profile) 1519 return NULL; 1520 1521 return bi; 1522 } 1523 1524 static inline 1525 struct blk_integrity *bdev_get_integrity(struct block_device *bdev) 1526 { 1527 return blk_get_integrity(bdev->bd_disk); 1528 } 1529 1530 static inline bool blk_integrity_rq(struct request *rq) 1531 { 1532 return rq->cmd_flags & REQ_INTEGRITY; 1533 } 1534 1535 static inline void blk_queue_max_integrity_segments(struct request_queue *q, 1536 unsigned int segs) 1537 { 1538 q->limits.max_integrity_segments = segs; 1539 } 1540 1541 static inline unsigned short 1542 queue_max_integrity_segments(struct request_queue *q) 1543 { 1544 return q->limits.max_integrity_segments; 1545 } 1546 1547 static inline bool integrity_req_gap_back_merge(struct request *req, 1548 struct bio *next) 1549 { 1550 struct bio_integrity_payload *bip = bio_integrity(req->bio); 1551 struct bio_integrity_payload *bip_next = bio_integrity(next); 1552 1553 return bvec_gap_to_prev(req->q, &bip->bip_vec[bip->bip_vcnt - 1], 1554 bip_next->bip_vec[0].bv_offset); 1555 } 1556 1557 static inline bool integrity_req_gap_front_merge(struct request *req, 1558 struct bio *bio) 1559 { 1560 struct bio_integrity_payload *bip = bio_integrity(bio); 1561 struct bio_integrity_payload *bip_next = bio_integrity(req->bio); 1562 1563 return bvec_gap_to_prev(req->q, &bip->bip_vec[bip->bip_vcnt - 1], 1564 bip_next->bip_vec[0].bv_offset); 1565 } 1566 1567 #else /* CONFIG_BLK_DEV_INTEGRITY */ 1568 1569 struct bio; 1570 struct block_device; 1571 struct gendisk; 1572 struct blk_integrity; 1573 1574 static inline int blk_integrity_rq(struct request *rq) 1575 { 1576 return 0; 1577 } 1578 static inline int blk_rq_count_integrity_sg(struct request_queue *q, 1579 struct bio *b) 1580 { 1581 return 0; 1582 } 1583 static inline int blk_rq_map_integrity_sg(struct request_queue *q, 1584 struct bio *b, 1585 struct scatterlist *s) 1586 { 1587 return 0; 1588 } 1589 static inline struct blk_integrity *bdev_get_integrity(struct block_device *b) 1590 { 1591 return NULL; 1592 } 1593 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk) 1594 { 1595 return NULL; 1596 } 1597 static inline int blk_integrity_compare(struct gendisk *a, struct gendisk *b) 1598 { 1599 return 0; 1600 } 1601 static inline void blk_integrity_register(struct gendisk *d, 1602 struct blk_integrity *b) 1603 { 1604 } 1605 static inline void blk_integrity_unregister(struct gendisk *d) 1606 { 1607 } 1608 static inline void blk_queue_max_integrity_segments(struct request_queue *q, 1609 unsigned int segs) 1610 { 1611 } 1612 static inline unsigned short queue_max_integrity_segments(struct request_queue *q) 1613 { 1614 return 0; 1615 } 1616 static inline bool blk_integrity_merge_rq(struct request_queue *rq, 1617 struct request *r1, 1618 struct request *r2) 1619 { 1620 return true; 1621 } 1622 static inline bool blk_integrity_merge_bio(struct request_queue *rq, 1623 struct request *r, 1624 struct bio *b) 1625 { 1626 return true; 1627 } 1628 1629 static inline bool integrity_req_gap_back_merge(struct request *req, 1630 struct bio *next) 1631 { 1632 return false; 1633 } 1634 static inline bool integrity_req_gap_front_merge(struct request *req, 1635 struct bio *bio) 1636 { 1637 return false; 1638 } 1639 1640 #endif /* CONFIG_BLK_DEV_INTEGRITY */ 1641 1642 /** 1643 * struct blk_dax_ctl - control and output parameters for ->direct_access 1644 * @sector: (input) offset relative to a block_device 1645 * @addr: (output) kernel virtual address for @sector populated by driver 1646 * @pfn: (output) page frame number for @addr populated by driver 1647 * @size: (input) number of bytes requested 1648 */ 1649 struct blk_dax_ctl { 1650 sector_t sector; 1651 void __pmem *addr; 1652 long size; 1653 pfn_t pfn; 1654 }; 1655 1656 struct block_device_operations { 1657 int (*open) (struct block_device *, fmode_t); 1658 void (*release) (struct gendisk *, fmode_t); 1659 int (*rw_page)(struct block_device *, sector_t, struct page *, int rw); 1660 int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long); 1661 int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long); 1662 long (*direct_access)(struct block_device *, sector_t, void __pmem **, 1663 pfn_t *); 1664 unsigned int (*check_events) (struct gendisk *disk, 1665 unsigned int clearing); 1666 /* ->media_changed() is DEPRECATED, use ->check_events() instead */ 1667 int (*media_changed) (struct gendisk *); 1668 void (*unlock_native_capacity) (struct gendisk *); 1669 int (*revalidate_disk) (struct gendisk *); 1670 int (*getgeo)(struct block_device *, struct hd_geometry *); 1671 /* this callback is with swap_lock and sometimes page table lock held */ 1672 void (*swap_slot_free_notify) (struct block_device *, unsigned long); 1673 struct module *owner; 1674 const struct pr_ops *pr_ops; 1675 }; 1676 1677 extern int __blkdev_driver_ioctl(struct block_device *, fmode_t, unsigned int, 1678 unsigned long); 1679 extern int bdev_read_page(struct block_device *, sector_t, struct page *); 1680 extern int bdev_write_page(struct block_device *, sector_t, struct page *, 1681 struct writeback_control *); 1682 extern long bdev_direct_access(struct block_device *, struct blk_dax_ctl *); 1683 #else /* CONFIG_BLOCK */ 1684 1685 struct block_device; 1686 1687 /* 1688 * stubs for when the block layer is configured out 1689 */ 1690 #define buffer_heads_over_limit 0 1691 1692 static inline long nr_blockdev_pages(void) 1693 { 1694 return 0; 1695 } 1696 1697 struct blk_plug { 1698 }; 1699 1700 static inline void blk_start_plug(struct blk_plug *plug) 1701 { 1702 } 1703 1704 static inline void blk_finish_plug(struct blk_plug *plug) 1705 { 1706 } 1707 1708 static inline void blk_flush_plug(struct task_struct *task) 1709 { 1710 } 1711 1712 static inline void blk_schedule_flush_plug(struct task_struct *task) 1713 { 1714 } 1715 1716 1717 static inline bool blk_needs_flush_plug(struct task_struct *tsk) 1718 { 1719 return false; 1720 } 1721 1722 static inline int blkdev_issue_flush(struct block_device *bdev, gfp_t gfp_mask, 1723 sector_t *error_sector) 1724 { 1725 return 0; 1726 } 1727 1728 #endif /* CONFIG_BLOCK */ 1729 1730 #endif 1731