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.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 25 #include <asm/scatterlist.h> 26 27 struct module; 28 struct scsi_ioctl_command; 29 30 struct request_queue; 31 struct elevator_queue; 32 struct request_pm_state; 33 struct blk_trace; 34 struct request; 35 struct sg_io_hdr; 36 struct bsg_job; 37 struct blkcg_gq; 38 39 #define BLKDEV_MIN_RQ 4 40 #define BLKDEV_MAX_RQ 128 /* Default maximum */ 41 42 /* 43 * Maximum number of blkcg policies allowed to be registered concurrently. 44 * Defined here to simplify include dependency. 45 */ 46 #define BLKCG_MAX_POLS 2 47 48 struct request; 49 typedef void (rq_end_io_fn)(struct request *, int); 50 51 #define BLK_RL_SYNCFULL (1U << 0) 52 #define BLK_RL_ASYNCFULL (1U << 1) 53 54 struct request_list { 55 struct request_queue *q; /* the queue this rl belongs to */ 56 #ifdef CONFIG_BLK_CGROUP 57 struct blkcg_gq *blkg; /* blkg this request pool belongs to */ 58 #endif 59 /* 60 * count[], starved[], and wait[] are indexed by 61 * BLK_RW_SYNC/BLK_RW_ASYNC 62 */ 63 int count[2]; 64 int starved[2]; 65 mempool_t *rq_pool; 66 wait_queue_head_t wait[2]; 67 unsigned int flags; 68 }; 69 70 /* 71 * request command types 72 */ 73 enum rq_cmd_type_bits { 74 REQ_TYPE_FS = 1, /* fs request */ 75 REQ_TYPE_BLOCK_PC, /* scsi command */ 76 REQ_TYPE_SENSE, /* sense request */ 77 REQ_TYPE_PM_SUSPEND, /* suspend request */ 78 REQ_TYPE_PM_RESUME, /* resume request */ 79 REQ_TYPE_PM_SHUTDOWN, /* shutdown request */ 80 REQ_TYPE_SPECIAL, /* driver defined type */ 81 /* 82 * for ATA/ATAPI devices. this really doesn't belong here, ide should 83 * use REQ_TYPE_SPECIAL and use rq->cmd[0] with the range of driver 84 * private REQ_LB opcodes to differentiate what type of request this is 85 */ 86 REQ_TYPE_ATA_TASKFILE, 87 REQ_TYPE_ATA_PC, 88 }; 89 90 #define BLK_MAX_CDB 16 91 92 /* 93 * try to put the fields that are referenced together in the same cacheline. 94 * if you modify this structure, be sure to check block/blk-core.c:blk_rq_init() 95 * as well! 96 */ 97 struct request { 98 struct list_head queuelist; 99 union { 100 struct call_single_data csd; 101 struct work_struct mq_flush_data; 102 }; 103 104 struct request_queue *q; 105 struct blk_mq_ctx *mq_ctx; 106 107 u64 cmd_flags; 108 enum rq_cmd_type_bits cmd_type; 109 unsigned long atomic_flags; 110 111 int cpu; 112 113 /* the following two fields are internal, NEVER access directly */ 114 unsigned int __data_len; /* total data len */ 115 sector_t __sector; /* sector cursor */ 116 117 struct bio *bio; 118 struct bio *biotail; 119 120 struct hlist_node hash; /* merge hash */ 121 /* 122 * The rb_node is only used inside the io scheduler, requests 123 * are pruned when moved to the dispatch queue. So let the 124 * completion_data share space with the rb_node. 125 */ 126 union { 127 struct rb_node rb_node; /* sort/lookup */ 128 void *completion_data; 129 }; 130 131 /* 132 * Three pointers are available for the IO schedulers, if they need 133 * more they have to dynamically allocate it. Flush requests are 134 * never put on the IO scheduler. So let the flush fields share 135 * space with the elevator data. 136 */ 137 union { 138 struct { 139 struct io_cq *icq; 140 void *priv[2]; 141 } elv; 142 143 struct { 144 unsigned int seq; 145 struct list_head list; 146 rq_end_io_fn *saved_end_io; 147 } flush; 148 }; 149 150 struct gendisk *rq_disk; 151 struct hd_struct *part; 152 unsigned long start_time; 153 #ifdef CONFIG_BLK_CGROUP 154 struct request_list *rl; /* rl this rq is alloced from */ 155 unsigned long long start_time_ns; 156 unsigned long long io_start_time_ns; /* when passed to hardware */ 157 #endif 158 /* Number of scatter-gather DMA addr+len pairs after 159 * physical address coalescing is performed. 160 */ 161 unsigned short nr_phys_segments; 162 #if defined(CONFIG_BLK_DEV_INTEGRITY) 163 unsigned short nr_integrity_segments; 164 #endif 165 166 unsigned short ioprio; 167 168 void *special; /* opaque pointer available for LLD use */ 169 char *buffer; /* kaddr of the current segment if available */ 170 171 int tag; 172 int errors; 173 174 /* 175 * when request is used as a packet command carrier 176 */ 177 unsigned char __cmd[BLK_MAX_CDB]; 178 unsigned char *cmd; 179 unsigned short cmd_len; 180 181 unsigned int extra_len; /* length of alignment and padding */ 182 unsigned int sense_len; 183 unsigned int resid_len; /* residual count */ 184 void *sense; 185 186 unsigned long deadline; 187 struct list_head timeout_list; 188 unsigned int timeout; 189 int retries; 190 191 /* 192 * completion callback. 193 */ 194 rq_end_io_fn *end_io; 195 void *end_io_data; 196 197 /* for bidi */ 198 struct request *next_rq; 199 }; 200 201 static inline unsigned short req_get_ioprio(struct request *req) 202 { 203 return req->ioprio; 204 } 205 206 /* 207 * State information carried for REQ_TYPE_PM_SUSPEND and REQ_TYPE_PM_RESUME 208 * requests. Some step values could eventually be made generic. 209 */ 210 struct request_pm_state 211 { 212 /* PM state machine step value, currently driver specific */ 213 int pm_step; 214 /* requested PM state value (S1, S2, S3, S4, ...) */ 215 u32 pm_state; 216 void* data; /* for driver use */ 217 }; 218 219 #include <linux/elevator.h> 220 221 struct blk_queue_ctx; 222 223 typedef void (request_fn_proc) (struct request_queue *q); 224 typedef void (make_request_fn) (struct request_queue *q, struct bio *bio); 225 typedef int (prep_rq_fn) (struct request_queue *, struct request *); 226 typedef void (unprep_rq_fn) (struct request_queue *, struct request *); 227 228 struct bio_vec; 229 struct bvec_merge_data { 230 struct block_device *bi_bdev; 231 sector_t bi_sector; 232 unsigned bi_size; 233 unsigned long bi_rw; 234 }; 235 typedef int (merge_bvec_fn) (struct request_queue *, struct bvec_merge_data *, 236 struct bio_vec *); 237 typedef void (softirq_done_fn)(struct request *); 238 typedef int (dma_drain_needed_fn)(struct request *); 239 typedef int (lld_busy_fn) (struct request_queue *q); 240 typedef int (bsg_job_fn) (struct bsg_job *); 241 242 enum blk_eh_timer_return { 243 BLK_EH_NOT_HANDLED, 244 BLK_EH_HANDLED, 245 BLK_EH_RESET_TIMER, 246 }; 247 248 typedef enum blk_eh_timer_return (rq_timed_out_fn)(struct request *); 249 250 enum blk_queue_state { 251 Queue_down, 252 Queue_up, 253 }; 254 255 struct blk_queue_tag { 256 struct request **tag_index; /* map of busy tags */ 257 unsigned long *tag_map; /* bit map of free/busy tags */ 258 int busy; /* current depth */ 259 int max_depth; /* what we will send to device */ 260 int real_max_depth; /* what the array can hold */ 261 atomic_t refcnt; /* map can be shared */ 262 }; 263 264 #define BLK_SCSI_MAX_CMDS (256) 265 #define BLK_SCSI_CMD_PER_LONG (BLK_SCSI_MAX_CMDS / (sizeof(long) * 8)) 266 267 struct queue_limits { 268 unsigned long bounce_pfn; 269 unsigned long seg_boundary_mask; 270 271 unsigned int max_hw_sectors; 272 unsigned int max_sectors; 273 unsigned int max_segment_size; 274 unsigned int physical_block_size; 275 unsigned int alignment_offset; 276 unsigned int io_min; 277 unsigned int io_opt; 278 unsigned int max_discard_sectors; 279 unsigned int max_write_same_sectors; 280 unsigned int discard_granularity; 281 unsigned int discard_alignment; 282 283 unsigned short logical_block_size; 284 unsigned short max_segments; 285 unsigned short max_integrity_segments; 286 287 unsigned char misaligned; 288 unsigned char discard_misaligned; 289 unsigned char cluster; 290 unsigned char discard_zeroes_data; 291 unsigned char raid_partial_stripes_expensive; 292 }; 293 294 struct request_queue { 295 /* 296 * Together with queue_head for cacheline sharing 297 */ 298 struct list_head queue_head; 299 struct request *last_merge; 300 struct elevator_queue *elevator; 301 int nr_rqs[2]; /* # allocated [a]sync rqs */ 302 int nr_rqs_elvpriv; /* # allocated rqs w/ elvpriv */ 303 304 /* 305 * If blkcg is not used, @q->root_rl serves all requests. If blkcg 306 * is used, root blkg allocates from @q->root_rl and all other 307 * blkgs from their own blkg->rl. Which one to use should be 308 * determined using bio_request_list(). 309 */ 310 struct request_list root_rl; 311 312 request_fn_proc *request_fn; 313 make_request_fn *make_request_fn; 314 prep_rq_fn *prep_rq_fn; 315 unprep_rq_fn *unprep_rq_fn; 316 merge_bvec_fn *merge_bvec_fn; 317 softirq_done_fn *softirq_done_fn; 318 rq_timed_out_fn *rq_timed_out_fn; 319 dma_drain_needed_fn *dma_drain_needed; 320 lld_busy_fn *lld_busy_fn; 321 322 struct blk_mq_ops *mq_ops; 323 324 unsigned int *mq_map; 325 326 /* sw queues */ 327 struct blk_mq_ctx *queue_ctx; 328 unsigned int nr_queues; 329 330 /* hw dispatch queues */ 331 struct blk_mq_hw_ctx **queue_hw_ctx; 332 unsigned int nr_hw_queues; 333 334 /* 335 * Dispatch queue sorting 336 */ 337 sector_t end_sector; 338 struct request *boundary_rq; 339 340 /* 341 * Delayed queue handling 342 */ 343 struct delayed_work delay_work; 344 345 struct backing_dev_info backing_dev_info; 346 347 /* 348 * The queue owner gets to use this for whatever they like. 349 * ll_rw_blk doesn't touch it. 350 */ 351 void *queuedata; 352 353 /* 354 * various queue flags, see QUEUE_* below 355 */ 356 unsigned long queue_flags; 357 358 /* 359 * ida allocated id for this queue. Used to index queues from 360 * ioctx. 361 */ 362 int id; 363 364 /* 365 * queue needs bounce pages for pages above this limit 366 */ 367 gfp_t bounce_gfp; 368 369 /* 370 * protects queue structures from reentrancy. ->__queue_lock should 371 * _never_ be used directly, it is queue private. always use 372 * ->queue_lock. 373 */ 374 spinlock_t __queue_lock; 375 spinlock_t *queue_lock; 376 377 /* 378 * queue kobject 379 */ 380 struct kobject kobj; 381 382 /* 383 * mq queue kobject 384 */ 385 struct kobject mq_kobj; 386 387 #ifdef CONFIG_PM_RUNTIME 388 struct device *dev; 389 int rpm_status; 390 unsigned int nr_pending; 391 #endif 392 393 /* 394 * queue settings 395 */ 396 unsigned long nr_requests; /* Max # of requests */ 397 unsigned int nr_congestion_on; 398 unsigned int nr_congestion_off; 399 unsigned int nr_batching; 400 401 unsigned int dma_drain_size; 402 void *dma_drain_buffer; 403 unsigned int dma_pad_mask; 404 unsigned int dma_alignment; 405 406 struct blk_queue_tag *queue_tags; 407 struct list_head tag_busy_list; 408 409 unsigned int nr_sorted; 410 unsigned int in_flight[2]; 411 /* 412 * Number of active block driver functions for which blk_drain_queue() 413 * must wait. Must be incremented around functions that unlock the 414 * queue_lock internally, e.g. scsi_request_fn(). 415 */ 416 unsigned int request_fn_active; 417 418 unsigned int rq_timeout; 419 struct timer_list timeout; 420 struct list_head timeout_list; 421 422 struct list_head icq_list; 423 #ifdef CONFIG_BLK_CGROUP 424 DECLARE_BITMAP (blkcg_pols, BLKCG_MAX_POLS); 425 struct blkcg_gq *root_blkg; 426 struct list_head blkg_list; 427 #endif 428 429 struct queue_limits limits; 430 431 /* 432 * sg stuff 433 */ 434 unsigned int sg_timeout; 435 unsigned int sg_reserved_size; 436 int node; 437 #ifdef CONFIG_BLK_DEV_IO_TRACE 438 struct blk_trace *blk_trace; 439 #endif 440 /* 441 * for flush operations 442 */ 443 unsigned int flush_flags; 444 unsigned int flush_not_queueable:1; 445 unsigned int flush_queue_delayed:1; 446 unsigned int flush_pending_idx:1; 447 unsigned int flush_running_idx:1; 448 unsigned long flush_pending_since; 449 struct list_head flush_queue[2]; 450 struct list_head flush_data_in_flight; 451 union { 452 struct request flush_rq; 453 struct { 454 spinlock_t mq_flush_lock; 455 struct work_struct mq_flush_work; 456 }; 457 }; 458 459 struct mutex sysfs_lock; 460 461 int bypass_depth; 462 463 #if defined(CONFIG_BLK_DEV_BSG) 464 bsg_job_fn *bsg_job_fn; 465 int bsg_job_size; 466 struct bsg_class_device bsg_dev; 467 #endif 468 469 #ifdef CONFIG_BLK_DEV_THROTTLING 470 /* Throttle data */ 471 struct throtl_data *td; 472 #endif 473 struct rcu_head rcu_head; 474 wait_queue_head_t mq_freeze_wq; 475 struct percpu_counter mq_usage_counter; 476 struct list_head all_q_node; 477 }; 478 479 #define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */ 480 #define QUEUE_FLAG_STOPPED 2 /* queue is stopped */ 481 #define QUEUE_FLAG_SYNCFULL 3 /* read queue has been filled */ 482 #define QUEUE_FLAG_ASYNCFULL 4 /* write queue has been filled */ 483 #define QUEUE_FLAG_DYING 5 /* queue being torn down */ 484 #define QUEUE_FLAG_BYPASS 6 /* act as dumb FIFO queue */ 485 #define QUEUE_FLAG_BIDI 7 /* queue supports bidi requests */ 486 #define QUEUE_FLAG_NOMERGES 8 /* disable merge attempts */ 487 #define QUEUE_FLAG_SAME_COMP 9 /* complete on same CPU-group */ 488 #define QUEUE_FLAG_FAIL_IO 10 /* fake timeout */ 489 #define QUEUE_FLAG_STACKABLE 11 /* supports request stacking */ 490 #define QUEUE_FLAG_NONROT 12 /* non-rotational device (SSD) */ 491 #define QUEUE_FLAG_VIRT QUEUE_FLAG_NONROT /* paravirt device */ 492 #define QUEUE_FLAG_IO_STAT 13 /* do IO stats */ 493 #define QUEUE_FLAG_DISCARD 14 /* supports DISCARD */ 494 #define QUEUE_FLAG_NOXMERGES 15 /* No extended merges */ 495 #define QUEUE_FLAG_ADD_RANDOM 16 /* Contributes to random pool */ 496 #define QUEUE_FLAG_SECDISCARD 17 /* supports SECDISCARD */ 497 #define QUEUE_FLAG_SAME_FORCE 18 /* force complete on same CPU */ 498 #define QUEUE_FLAG_DEAD 19 /* queue tear-down finished */ 499 #define QUEUE_FLAG_INIT_DONE 20 /* queue is initialized */ 500 501 #define QUEUE_FLAG_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \ 502 (1 << QUEUE_FLAG_STACKABLE) | \ 503 (1 << QUEUE_FLAG_SAME_COMP) | \ 504 (1 << QUEUE_FLAG_ADD_RANDOM)) 505 506 #define QUEUE_FLAG_MQ_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \ 507 (1 << QUEUE_FLAG_SAME_COMP)) 508 509 static inline void queue_lockdep_assert_held(struct request_queue *q) 510 { 511 if (q->queue_lock) 512 lockdep_assert_held(q->queue_lock); 513 } 514 515 static inline void queue_flag_set_unlocked(unsigned int flag, 516 struct request_queue *q) 517 { 518 __set_bit(flag, &q->queue_flags); 519 } 520 521 static inline int queue_flag_test_and_clear(unsigned int flag, 522 struct request_queue *q) 523 { 524 queue_lockdep_assert_held(q); 525 526 if (test_bit(flag, &q->queue_flags)) { 527 __clear_bit(flag, &q->queue_flags); 528 return 1; 529 } 530 531 return 0; 532 } 533 534 static inline int queue_flag_test_and_set(unsigned int flag, 535 struct request_queue *q) 536 { 537 queue_lockdep_assert_held(q); 538 539 if (!test_bit(flag, &q->queue_flags)) { 540 __set_bit(flag, &q->queue_flags); 541 return 0; 542 } 543 544 return 1; 545 } 546 547 static inline void queue_flag_set(unsigned int flag, struct request_queue *q) 548 { 549 queue_lockdep_assert_held(q); 550 __set_bit(flag, &q->queue_flags); 551 } 552 553 static inline void queue_flag_clear_unlocked(unsigned int flag, 554 struct request_queue *q) 555 { 556 __clear_bit(flag, &q->queue_flags); 557 } 558 559 static inline int queue_in_flight(struct request_queue *q) 560 { 561 return q->in_flight[0] + q->in_flight[1]; 562 } 563 564 static inline void queue_flag_clear(unsigned int flag, struct request_queue *q) 565 { 566 queue_lockdep_assert_held(q); 567 __clear_bit(flag, &q->queue_flags); 568 } 569 570 #define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags) 571 #define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags) 572 #define blk_queue_dying(q) test_bit(QUEUE_FLAG_DYING, &(q)->queue_flags) 573 #define blk_queue_dead(q) test_bit(QUEUE_FLAG_DEAD, &(q)->queue_flags) 574 #define blk_queue_bypass(q) test_bit(QUEUE_FLAG_BYPASS, &(q)->queue_flags) 575 #define blk_queue_init_done(q) test_bit(QUEUE_FLAG_INIT_DONE, &(q)->queue_flags) 576 #define blk_queue_nomerges(q) test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags) 577 #define blk_queue_noxmerges(q) \ 578 test_bit(QUEUE_FLAG_NOXMERGES, &(q)->queue_flags) 579 #define blk_queue_nonrot(q) test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags) 580 #define blk_queue_io_stat(q) test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags) 581 #define blk_queue_add_random(q) test_bit(QUEUE_FLAG_ADD_RANDOM, &(q)->queue_flags) 582 #define blk_queue_stackable(q) \ 583 test_bit(QUEUE_FLAG_STACKABLE, &(q)->queue_flags) 584 #define blk_queue_discard(q) test_bit(QUEUE_FLAG_DISCARD, &(q)->queue_flags) 585 #define blk_queue_secdiscard(q) (blk_queue_discard(q) && \ 586 test_bit(QUEUE_FLAG_SECDISCARD, &(q)->queue_flags)) 587 588 #define blk_noretry_request(rq) \ 589 ((rq)->cmd_flags & (REQ_FAILFAST_DEV|REQ_FAILFAST_TRANSPORT| \ 590 REQ_FAILFAST_DRIVER)) 591 592 #define blk_account_rq(rq) \ 593 (((rq)->cmd_flags & REQ_STARTED) && \ 594 ((rq)->cmd_type == REQ_TYPE_FS)) 595 596 #define blk_pm_request(rq) \ 597 ((rq)->cmd_type == REQ_TYPE_PM_SUSPEND || \ 598 (rq)->cmd_type == REQ_TYPE_PM_RESUME) 599 600 #define blk_rq_cpu_valid(rq) ((rq)->cpu != -1) 601 #define blk_bidi_rq(rq) ((rq)->next_rq != NULL) 602 /* rq->queuelist of dequeued request must be list_empty() */ 603 #define blk_queued_rq(rq) (!list_empty(&(rq)->queuelist)) 604 605 #define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist) 606 607 #define rq_data_dir(rq) (((rq)->cmd_flags & 1) != 0) 608 609 static inline unsigned int blk_queue_cluster(struct request_queue *q) 610 { 611 return q->limits.cluster; 612 } 613 614 /* 615 * We regard a request as sync, if either a read or a sync write 616 */ 617 static inline bool rw_is_sync(unsigned int rw_flags) 618 { 619 return !(rw_flags & REQ_WRITE) || (rw_flags & REQ_SYNC); 620 } 621 622 static inline bool rq_is_sync(struct request *rq) 623 { 624 return rw_is_sync(rq->cmd_flags); 625 } 626 627 static inline bool blk_rl_full(struct request_list *rl, bool sync) 628 { 629 unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL; 630 631 return rl->flags & flag; 632 } 633 634 static inline void blk_set_rl_full(struct request_list *rl, bool sync) 635 { 636 unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL; 637 638 rl->flags |= flag; 639 } 640 641 static inline void blk_clear_rl_full(struct request_list *rl, bool sync) 642 { 643 unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL; 644 645 rl->flags &= ~flag; 646 } 647 648 static inline bool rq_mergeable(struct request *rq) 649 { 650 if (rq->cmd_type != REQ_TYPE_FS) 651 return false; 652 653 if (rq->cmd_flags & REQ_NOMERGE_FLAGS) 654 return false; 655 656 return true; 657 } 658 659 static inline bool blk_check_merge_flags(unsigned int flags1, 660 unsigned int flags2) 661 { 662 if ((flags1 & REQ_DISCARD) != (flags2 & REQ_DISCARD)) 663 return false; 664 665 if ((flags1 & REQ_SECURE) != (flags2 & REQ_SECURE)) 666 return false; 667 668 if ((flags1 & REQ_WRITE_SAME) != (flags2 & REQ_WRITE_SAME)) 669 return false; 670 671 return true; 672 } 673 674 static inline bool blk_write_same_mergeable(struct bio *a, struct bio *b) 675 { 676 if (bio_data(a) == bio_data(b)) 677 return true; 678 679 return false; 680 } 681 682 /* 683 * q->prep_rq_fn return values 684 */ 685 #define BLKPREP_OK 0 /* serve it */ 686 #define BLKPREP_KILL 1 /* fatal error, kill */ 687 #define BLKPREP_DEFER 2 /* leave on queue */ 688 689 extern unsigned long blk_max_low_pfn, blk_max_pfn; 690 691 /* 692 * standard bounce addresses: 693 * 694 * BLK_BOUNCE_HIGH : bounce all highmem pages 695 * BLK_BOUNCE_ANY : don't bounce anything 696 * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary 697 */ 698 699 #if BITS_PER_LONG == 32 700 #define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT) 701 #else 702 #define BLK_BOUNCE_HIGH -1ULL 703 #endif 704 #define BLK_BOUNCE_ANY (-1ULL) 705 #define BLK_BOUNCE_ISA (DMA_BIT_MASK(24)) 706 707 /* 708 * default timeout for SG_IO if none specified 709 */ 710 #define BLK_DEFAULT_SG_TIMEOUT (60 * HZ) 711 #define BLK_MIN_SG_TIMEOUT (7 * HZ) 712 713 #ifdef CONFIG_BOUNCE 714 extern int init_emergency_isa_pool(void); 715 extern void blk_queue_bounce(struct request_queue *q, struct bio **bio); 716 #else 717 static inline int init_emergency_isa_pool(void) 718 { 719 return 0; 720 } 721 static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio) 722 { 723 } 724 #endif /* CONFIG_MMU */ 725 726 struct rq_map_data { 727 struct page **pages; 728 int page_order; 729 int nr_entries; 730 unsigned long offset; 731 int null_mapped; 732 int from_user; 733 }; 734 735 struct req_iterator { 736 struct bvec_iter iter; 737 struct bio *bio; 738 }; 739 740 /* This should not be used directly - use rq_for_each_segment */ 741 #define for_each_bio(_bio) \ 742 for (; _bio; _bio = _bio->bi_next) 743 #define __rq_for_each_bio(_bio, rq) \ 744 if ((rq->bio)) \ 745 for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next) 746 747 #define rq_for_each_segment(bvl, _rq, _iter) \ 748 __rq_for_each_bio(_iter.bio, _rq) \ 749 bio_for_each_segment(bvl, _iter.bio, _iter.iter) 750 751 #define rq_iter_last(bvec, _iter) \ 752 (_iter.bio->bi_next == NULL && \ 753 bio_iter_last(bvec, _iter.iter)) 754 755 #ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 756 # error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform" 757 #endif 758 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 759 extern void rq_flush_dcache_pages(struct request *rq); 760 #else 761 static inline void rq_flush_dcache_pages(struct request *rq) 762 { 763 } 764 #endif 765 766 extern int blk_register_queue(struct gendisk *disk); 767 extern void blk_unregister_queue(struct gendisk *disk); 768 extern void generic_make_request(struct bio *bio); 769 extern void blk_rq_init(struct request_queue *q, struct request *rq); 770 extern void blk_put_request(struct request *); 771 extern void __blk_put_request(struct request_queue *, struct request *); 772 extern struct request *blk_get_request(struct request_queue *, int, gfp_t); 773 extern struct request *blk_make_request(struct request_queue *, struct bio *, 774 gfp_t); 775 extern void blk_requeue_request(struct request_queue *, struct request *); 776 extern void blk_add_request_payload(struct request *rq, struct page *page, 777 unsigned int len); 778 extern int blk_rq_check_limits(struct request_queue *q, struct request *rq); 779 extern int blk_lld_busy(struct request_queue *q); 780 extern int blk_rq_prep_clone(struct request *rq, struct request *rq_src, 781 struct bio_set *bs, gfp_t gfp_mask, 782 int (*bio_ctr)(struct bio *, struct bio *, void *), 783 void *data); 784 extern void blk_rq_unprep_clone(struct request *rq); 785 extern int blk_insert_cloned_request(struct request_queue *q, 786 struct request *rq); 787 extern void blk_delay_queue(struct request_queue *, unsigned long); 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_queue_bio(struct request_queue *q, struct bio *bio); 798 799 /* 800 * A queue has just exitted congestion. Note this in the global counter of 801 * congested queues, and wake up anyone who was waiting for requests to be 802 * put back. 803 */ 804 static inline void blk_clear_queue_congested(struct request_queue *q, int sync) 805 { 806 clear_bdi_congested(&q->backing_dev_info, sync); 807 } 808 809 /* 810 * A queue has just entered congestion. Flag that in the queue's VM-visible 811 * state flags and increment the global gounter of congested queues. 812 */ 813 static inline void blk_set_queue_congested(struct request_queue *q, int sync) 814 { 815 set_bdi_congested(&q->backing_dev_info, sync); 816 } 817 818 extern void blk_start_queue(struct request_queue *q); 819 extern void blk_stop_queue(struct request_queue *q); 820 extern void blk_sync_queue(struct request_queue *q); 821 extern void __blk_stop_queue(struct request_queue *q); 822 extern void __blk_run_queue(struct request_queue *q); 823 extern void blk_run_queue(struct request_queue *); 824 extern void blk_run_queue_async(struct request_queue *q); 825 extern int blk_rq_map_user(struct request_queue *, struct request *, 826 struct rq_map_data *, void __user *, unsigned long, 827 gfp_t); 828 extern int blk_rq_unmap_user(struct bio *); 829 extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, unsigned int, gfp_t); 830 extern int blk_rq_map_user_iov(struct request_queue *, struct request *, 831 struct rq_map_data *, struct sg_iovec *, int, 832 unsigned int, gfp_t); 833 extern int blk_execute_rq(struct request_queue *, struct gendisk *, 834 struct request *, int); 835 extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *, 836 struct request *, int, rq_end_io_fn *); 837 838 static inline struct request_queue *bdev_get_queue(struct block_device *bdev) 839 { 840 return bdev->bd_disk->queue; 841 } 842 843 /* 844 * blk_rq_pos() : the current sector 845 * blk_rq_bytes() : bytes left in the entire request 846 * blk_rq_cur_bytes() : bytes left in the current segment 847 * blk_rq_err_bytes() : bytes left till the next error boundary 848 * blk_rq_sectors() : sectors left in the entire request 849 * blk_rq_cur_sectors() : sectors left in the current segment 850 */ 851 static inline sector_t blk_rq_pos(const struct request *rq) 852 { 853 return rq->__sector; 854 } 855 856 static inline unsigned int blk_rq_bytes(const struct request *rq) 857 { 858 return rq->__data_len; 859 } 860 861 static inline int blk_rq_cur_bytes(const struct request *rq) 862 { 863 return rq->bio ? bio_cur_bytes(rq->bio) : 0; 864 } 865 866 extern unsigned int blk_rq_err_bytes(const struct request *rq); 867 868 static inline unsigned int blk_rq_sectors(const struct request *rq) 869 { 870 return blk_rq_bytes(rq) >> 9; 871 } 872 873 static inline unsigned int blk_rq_cur_sectors(const struct request *rq) 874 { 875 return blk_rq_cur_bytes(rq) >> 9; 876 } 877 878 static inline unsigned int blk_queue_get_max_sectors(struct request_queue *q, 879 unsigned int cmd_flags) 880 { 881 if (unlikely(cmd_flags & REQ_DISCARD)) 882 return min(q->limits.max_discard_sectors, UINT_MAX >> 9); 883 884 if (unlikely(cmd_flags & REQ_WRITE_SAME)) 885 return q->limits.max_write_same_sectors; 886 887 return q->limits.max_sectors; 888 } 889 890 static inline unsigned int blk_rq_get_max_sectors(struct request *rq) 891 { 892 struct request_queue *q = rq->q; 893 894 if (unlikely(rq->cmd_type == REQ_TYPE_BLOCK_PC)) 895 return q->limits.max_hw_sectors; 896 897 return 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 bool blk_end_request(struct request *rq, int error, 934 unsigned int nr_bytes); 935 extern void blk_end_request_all(struct request *rq, int error); 936 extern bool blk_end_request_cur(struct request *rq, int error); 937 extern bool blk_end_request_err(struct request *rq, int error); 938 extern bool __blk_end_request(struct request *rq, int error, 939 unsigned int nr_bytes); 940 extern void __blk_end_request_all(struct request *rq, int error); 941 extern bool __blk_end_request_cur(struct request *rq, int error); 942 extern bool __blk_end_request_err(struct request *rq, int error); 943 944 extern void blk_complete_request(struct request *); 945 extern void __blk_complete_request(struct request *); 946 extern void blk_abort_request(struct request *); 947 extern void blk_unprep_request(struct request *); 948 949 /* 950 * Access functions for manipulating queue properties 951 */ 952 extern struct request_queue *blk_init_queue_node(request_fn_proc *rfn, 953 spinlock_t *lock, int node_id); 954 extern struct request_queue *blk_init_queue(request_fn_proc *, spinlock_t *); 955 extern struct request_queue *blk_init_allocated_queue(struct request_queue *, 956 request_fn_proc *, spinlock_t *); 957 extern void blk_cleanup_queue(struct request_queue *); 958 extern void blk_queue_make_request(struct request_queue *, make_request_fn *); 959 extern void blk_queue_bounce_limit(struct request_queue *, u64); 960 extern void blk_limits_max_hw_sectors(struct queue_limits *, unsigned int); 961 extern void blk_queue_max_hw_sectors(struct request_queue *, unsigned int); 962 extern void blk_queue_max_segments(struct request_queue *, unsigned short); 963 extern void blk_queue_max_segment_size(struct request_queue *, unsigned int); 964 extern void blk_queue_max_discard_sectors(struct request_queue *q, 965 unsigned int max_discard_sectors); 966 extern void blk_queue_max_write_same_sectors(struct request_queue *q, 967 unsigned int max_write_same_sectors); 968 extern void blk_queue_logical_block_size(struct request_queue *, unsigned short); 969 extern void blk_queue_physical_block_size(struct request_queue *, unsigned int); 970 extern void blk_queue_alignment_offset(struct request_queue *q, 971 unsigned int alignment); 972 extern void blk_limits_io_min(struct queue_limits *limits, unsigned int min); 973 extern void blk_queue_io_min(struct request_queue *q, unsigned int min); 974 extern void blk_limits_io_opt(struct queue_limits *limits, unsigned int opt); 975 extern void blk_queue_io_opt(struct request_queue *q, unsigned int opt); 976 extern void blk_set_default_limits(struct queue_limits *lim); 977 extern void blk_set_stacking_limits(struct queue_limits *lim); 978 extern int blk_stack_limits(struct queue_limits *t, struct queue_limits *b, 979 sector_t offset); 980 extern int bdev_stack_limits(struct queue_limits *t, struct block_device *bdev, 981 sector_t offset); 982 extern void disk_stack_limits(struct gendisk *disk, struct block_device *bdev, 983 sector_t offset); 984 extern void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b); 985 extern void blk_queue_dma_pad(struct request_queue *, unsigned int); 986 extern void blk_queue_update_dma_pad(struct request_queue *, unsigned int); 987 extern int blk_queue_dma_drain(struct request_queue *q, 988 dma_drain_needed_fn *dma_drain_needed, 989 void *buf, unsigned int size); 990 extern void blk_queue_lld_busy(struct request_queue *q, lld_busy_fn *fn); 991 extern void blk_queue_segment_boundary(struct request_queue *, unsigned long); 992 extern void blk_queue_prep_rq(struct request_queue *, prep_rq_fn *pfn); 993 extern void blk_queue_unprep_rq(struct request_queue *, unprep_rq_fn *ufn); 994 extern void blk_queue_merge_bvec(struct request_queue *, merge_bvec_fn *); 995 extern void blk_queue_dma_alignment(struct request_queue *, int); 996 extern void blk_queue_update_dma_alignment(struct request_queue *, int); 997 extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *); 998 extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *); 999 extern void blk_queue_rq_timeout(struct request_queue *, unsigned int); 1000 extern void blk_queue_flush(struct request_queue *q, unsigned int flush); 1001 extern void blk_queue_flush_queueable(struct request_queue *q, bool queueable); 1002 extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev); 1003 1004 extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *); 1005 extern int blk_bio_map_sg(struct request_queue *q, struct bio *bio, 1006 struct scatterlist *sglist); 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 1015 /* 1016 * block layer runtime pm functions 1017 */ 1018 #ifdef CONFIG_PM_RUNTIME 1019 extern void blk_pm_runtime_init(struct request_queue *q, struct device *dev); 1020 extern int blk_pre_runtime_suspend(struct request_queue *q); 1021 extern void blk_post_runtime_suspend(struct request_queue *q, int err); 1022 extern void blk_pre_runtime_resume(struct request_queue *q); 1023 extern void blk_post_runtime_resume(struct request_queue *q, int err); 1024 #else 1025 static inline void blk_pm_runtime_init(struct request_queue *q, 1026 struct device *dev) {} 1027 static inline int blk_pre_runtime_suspend(struct request_queue *q) 1028 { 1029 return -ENOSYS; 1030 } 1031 static inline void blk_post_runtime_suspend(struct request_queue *q, int err) {} 1032 static inline void blk_pre_runtime_resume(struct request_queue *q) {} 1033 static inline void blk_post_runtime_resume(struct request_queue *q, int err) {} 1034 #endif 1035 1036 /* 1037 * blk_plug permits building a queue of related requests by holding the I/O 1038 * fragments for a short period. This allows merging of sequential requests 1039 * into single larger request. As the requests are moved from a per-task list to 1040 * the device's request_queue in a batch, this results in improved scalability 1041 * as the lock contention for request_queue lock is reduced. 1042 * 1043 * It is ok not to disable preemption when adding the request to the plug list 1044 * or when attempting a merge, because blk_schedule_flush_list() will only flush 1045 * the plug list when the task sleeps by itself. For details, please see 1046 * schedule() where blk_schedule_flush_plug() is called. 1047 */ 1048 struct blk_plug { 1049 unsigned long magic; /* detect uninitialized use-cases */ 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 #define blk_rq_tagged(rq) ((rq)->cmd_flags & REQ_QUEUED) 1099 extern int blk_queue_start_tag(struct request_queue *, struct request *); 1100 extern struct request *blk_queue_find_tag(struct request_queue *, int); 1101 extern void blk_queue_end_tag(struct request_queue *, struct request *); 1102 extern int blk_queue_init_tags(struct request_queue *, int, struct blk_queue_tag *); 1103 extern void blk_queue_free_tags(struct request_queue *); 1104 extern int blk_queue_resize_tags(struct request_queue *, int); 1105 extern void blk_queue_invalidate_tags(struct request_queue *); 1106 extern struct blk_queue_tag *blk_init_tags(int); 1107 extern void blk_free_tags(struct blk_queue_tag *); 1108 1109 static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt, 1110 int tag) 1111 { 1112 if (unlikely(bqt == NULL || tag >= bqt->real_max_depth)) 1113 return NULL; 1114 return bqt->tag_index[tag]; 1115 } 1116 1117 #define BLKDEV_DISCARD_SECURE 0x01 /* secure discard */ 1118 1119 extern int blkdev_issue_flush(struct block_device *, gfp_t, sector_t *); 1120 extern int blkdev_issue_discard(struct block_device *bdev, sector_t sector, 1121 sector_t nr_sects, gfp_t gfp_mask, unsigned long flags); 1122 extern int blkdev_issue_write_same(struct block_device *bdev, sector_t sector, 1123 sector_t nr_sects, gfp_t gfp_mask, struct page *page); 1124 extern int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector, 1125 sector_t nr_sects, gfp_t gfp_mask); 1126 static inline int sb_issue_discard(struct super_block *sb, sector_t block, 1127 sector_t nr_blocks, gfp_t gfp_mask, unsigned long flags) 1128 { 1129 return blkdev_issue_discard(sb->s_bdev, block << (sb->s_blocksize_bits - 9), 1130 nr_blocks << (sb->s_blocksize_bits - 9), 1131 gfp_mask, flags); 1132 } 1133 static inline int sb_issue_zeroout(struct super_block *sb, sector_t block, 1134 sector_t nr_blocks, gfp_t gfp_mask) 1135 { 1136 return blkdev_issue_zeroout(sb->s_bdev, 1137 block << (sb->s_blocksize_bits - 9), 1138 nr_blocks << (sb->s_blocksize_bits - 9), 1139 gfp_mask); 1140 } 1141 1142 extern int blk_verify_command(unsigned char *cmd, fmode_t has_write_perm); 1143 1144 enum blk_default_limits { 1145 BLK_MAX_SEGMENTS = 128, 1146 BLK_SAFE_MAX_SECTORS = 255, 1147 BLK_DEF_MAX_SECTORS = 1024, 1148 BLK_MAX_SEGMENT_SIZE = 65536, 1149 BLK_SEG_BOUNDARY_MASK = 0xFFFFFFFFUL, 1150 }; 1151 1152 #define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist) 1153 1154 static inline unsigned long queue_bounce_pfn(struct request_queue *q) 1155 { 1156 return q->limits.bounce_pfn; 1157 } 1158 1159 static inline unsigned long queue_segment_boundary(struct request_queue *q) 1160 { 1161 return q->limits.seg_boundary_mask; 1162 } 1163 1164 static inline unsigned int queue_max_sectors(struct request_queue *q) 1165 { 1166 return q->limits.max_sectors; 1167 } 1168 1169 static inline unsigned int queue_max_hw_sectors(struct request_queue *q) 1170 { 1171 return q->limits.max_hw_sectors; 1172 } 1173 1174 static inline unsigned short queue_max_segments(struct request_queue *q) 1175 { 1176 return q->limits.max_segments; 1177 } 1178 1179 static inline unsigned int queue_max_segment_size(struct request_queue *q) 1180 { 1181 return q->limits.max_segment_size; 1182 } 1183 1184 static inline unsigned short queue_logical_block_size(struct request_queue *q) 1185 { 1186 int retval = 512; 1187 1188 if (q && q->limits.logical_block_size) 1189 retval = q->limits.logical_block_size; 1190 1191 return retval; 1192 } 1193 1194 static inline unsigned short bdev_logical_block_size(struct block_device *bdev) 1195 { 1196 return queue_logical_block_size(bdev_get_queue(bdev)); 1197 } 1198 1199 static inline unsigned int queue_physical_block_size(struct request_queue *q) 1200 { 1201 return q->limits.physical_block_size; 1202 } 1203 1204 static inline unsigned int bdev_physical_block_size(struct block_device *bdev) 1205 { 1206 return queue_physical_block_size(bdev_get_queue(bdev)); 1207 } 1208 1209 static inline unsigned int queue_io_min(struct request_queue *q) 1210 { 1211 return q->limits.io_min; 1212 } 1213 1214 static inline int bdev_io_min(struct block_device *bdev) 1215 { 1216 return queue_io_min(bdev_get_queue(bdev)); 1217 } 1218 1219 static inline unsigned int queue_io_opt(struct request_queue *q) 1220 { 1221 return q->limits.io_opt; 1222 } 1223 1224 static inline int bdev_io_opt(struct block_device *bdev) 1225 { 1226 return queue_io_opt(bdev_get_queue(bdev)); 1227 } 1228 1229 static inline int queue_alignment_offset(struct request_queue *q) 1230 { 1231 if (q->limits.misaligned) 1232 return -1; 1233 1234 return q->limits.alignment_offset; 1235 } 1236 1237 static inline int queue_limit_alignment_offset(struct queue_limits *lim, sector_t sector) 1238 { 1239 unsigned int granularity = max(lim->physical_block_size, lim->io_min); 1240 unsigned int alignment = (sector << 9) & (granularity - 1); 1241 1242 return (granularity + lim->alignment_offset - alignment) 1243 & (granularity - 1); 1244 } 1245 1246 static inline int bdev_alignment_offset(struct block_device *bdev) 1247 { 1248 struct request_queue *q = bdev_get_queue(bdev); 1249 1250 if (q->limits.misaligned) 1251 return -1; 1252 1253 if (bdev != bdev->bd_contains) 1254 return bdev->bd_part->alignment_offset; 1255 1256 return q->limits.alignment_offset; 1257 } 1258 1259 static inline int queue_discard_alignment(struct request_queue *q) 1260 { 1261 if (q->limits.discard_misaligned) 1262 return -1; 1263 1264 return q->limits.discard_alignment; 1265 } 1266 1267 static inline int queue_limit_discard_alignment(struct queue_limits *lim, sector_t sector) 1268 { 1269 unsigned int alignment, granularity, offset; 1270 1271 if (!lim->max_discard_sectors) 1272 return 0; 1273 1274 /* Why are these in bytes, not sectors? */ 1275 alignment = lim->discard_alignment >> 9; 1276 granularity = lim->discard_granularity >> 9; 1277 if (!granularity) 1278 return 0; 1279 1280 /* Offset of the partition start in 'granularity' sectors */ 1281 offset = sector_div(sector, granularity); 1282 1283 /* And why do we do this modulus *again* in blkdev_issue_discard()? */ 1284 offset = (granularity + alignment - offset) % granularity; 1285 1286 /* Turn it back into bytes, gaah */ 1287 return offset << 9; 1288 } 1289 1290 static inline int bdev_discard_alignment(struct block_device *bdev) 1291 { 1292 struct request_queue *q = bdev_get_queue(bdev); 1293 1294 if (bdev != bdev->bd_contains) 1295 return bdev->bd_part->discard_alignment; 1296 1297 return q->limits.discard_alignment; 1298 } 1299 1300 static inline unsigned int queue_discard_zeroes_data(struct request_queue *q) 1301 { 1302 if (q->limits.max_discard_sectors && q->limits.discard_zeroes_data == 1) 1303 return 1; 1304 1305 return 0; 1306 } 1307 1308 static inline unsigned int bdev_discard_zeroes_data(struct block_device *bdev) 1309 { 1310 return queue_discard_zeroes_data(bdev_get_queue(bdev)); 1311 } 1312 1313 static inline unsigned int bdev_write_same(struct block_device *bdev) 1314 { 1315 struct request_queue *q = bdev_get_queue(bdev); 1316 1317 if (q) 1318 return q->limits.max_write_same_sectors; 1319 1320 return 0; 1321 } 1322 1323 static inline int queue_dma_alignment(struct request_queue *q) 1324 { 1325 return q ? q->dma_alignment : 511; 1326 } 1327 1328 static inline int blk_rq_aligned(struct request_queue *q, unsigned long addr, 1329 unsigned int len) 1330 { 1331 unsigned int alignment = queue_dma_alignment(q) | q->dma_pad_mask; 1332 return !(addr & alignment) && !(len & alignment); 1333 } 1334 1335 /* assumes size > 256 */ 1336 static inline unsigned int blksize_bits(unsigned int size) 1337 { 1338 unsigned int bits = 8; 1339 do { 1340 bits++; 1341 size >>= 1; 1342 } while (size > 256); 1343 return bits; 1344 } 1345 1346 static inline unsigned int block_size(struct block_device *bdev) 1347 { 1348 return bdev->bd_block_size; 1349 } 1350 1351 static inline bool queue_flush_queueable(struct request_queue *q) 1352 { 1353 return !q->flush_not_queueable; 1354 } 1355 1356 typedef struct {struct page *v;} Sector; 1357 1358 unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *); 1359 1360 static inline void put_dev_sector(Sector p) 1361 { 1362 page_cache_release(p.v); 1363 } 1364 1365 struct work_struct; 1366 int kblockd_schedule_work(struct request_queue *q, struct work_struct *work); 1367 int kblockd_schedule_delayed_work(struct request_queue *q, struct delayed_work *dwork, unsigned long delay); 1368 1369 #ifdef CONFIG_BLK_CGROUP 1370 /* 1371 * This should not be using sched_clock(). A real patch is in progress 1372 * to fix this up, until that is in place we need to disable preemption 1373 * around sched_clock() in this function and set_io_start_time_ns(). 1374 */ 1375 static inline void set_start_time_ns(struct request *req) 1376 { 1377 preempt_disable(); 1378 req->start_time_ns = sched_clock(); 1379 preempt_enable(); 1380 } 1381 1382 static inline void set_io_start_time_ns(struct request *req) 1383 { 1384 preempt_disable(); 1385 req->io_start_time_ns = sched_clock(); 1386 preempt_enable(); 1387 } 1388 1389 static inline uint64_t rq_start_time_ns(struct request *req) 1390 { 1391 return req->start_time_ns; 1392 } 1393 1394 static inline uint64_t rq_io_start_time_ns(struct request *req) 1395 { 1396 return req->io_start_time_ns; 1397 } 1398 #else 1399 static inline void set_start_time_ns(struct request *req) {} 1400 static inline void set_io_start_time_ns(struct request *req) {} 1401 static inline uint64_t rq_start_time_ns(struct request *req) 1402 { 1403 return 0; 1404 } 1405 static inline uint64_t rq_io_start_time_ns(struct request *req) 1406 { 1407 return 0; 1408 } 1409 #endif 1410 1411 #define MODULE_ALIAS_BLOCKDEV(major,minor) \ 1412 MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor)) 1413 #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \ 1414 MODULE_ALIAS("block-major-" __stringify(major) "-*") 1415 1416 #if defined(CONFIG_BLK_DEV_INTEGRITY) 1417 1418 #define INTEGRITY_FLAG_READ 2 /* verify data integrity on read */ 1419 #define INTEGRITY_FLAG_WRITE 4 /* generate data integrity on write */ 1420 1421 struct blk_integrity_exchg { 1422 void *prot_buf; 1423 void *data_buf; 1424 sector_t sector; 1425 unsigned int data_size; 1426 unsigned short sector_size; 1427 const char *disk_name; 1428 }; 1429 1430 typedef void (integrity_gen_fn) (struct blk_integrity_exchg *); 1431 typedef int (integrity_vrfy_fn) (struct blk_integrity_exchg *); 1432 typedef void (integrity_set_tag_fn) (void *, void *, unsigned int); 1433 typedef void (integrity_get_tag_fn) (void *, void *, unsigned int); 1434 1435 struct blk_integrity { 1436 integrity_gen_fn *generate_fn; 1437 integrity_vrfy_fn *verify_fn; 1438 integrity_set_tag_fn *set_tag_fn; 1439 integrity_get_tag_fn *get_tag_fn; 1440 1441 unsigned short flags; 1442 unsigned short tuple_size; 1443 unsigned short sector_size; 1444 unsigned short tag_size; 1445 1446 const char *name; 1447 1448 struct kobject kobj; 1449 }; 1450 1451 extern bool blk_integrity_is_initialized(struct gendisk *); 1452 extern int blk_integrity_register(struct gendisk *, struct blk_integrity *); 1453 extern void blk_integrity_unregister(struct gendisk *); 1454 extern int blk_integrity_compare(struct gendisk *, struct gendisk *); 1455 extern int blk_rq_map_integrity_sg(struct request_queue *, struct bio *, 1456 struct scatterlist *); 1457 extern int blk_rq_count_integrity_sg(struct request_queue *, struct bio *); 1458 extern int blk_integrity_merge_rq(struct request_queue *, struct request *, 1459 struct request *); 1460 extern int blk_integrity_merge_bio(struct request_queue *, struct request *, 1461 struct bio *); 1462 1463 static inline 1464 struct blk_integrity *bdev_get_integrity(struct block_device *bdev) 1465 { 1466 return bdev->bd_disk->integrity; 1467 } 1468 1469 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk) 1470 { 1471 return disk->integrity; 1472 } 1473 1474 static inline int blk_integrity_rq(struct request *rq) 1475 { 1476 if (rq->bio == NULL) 1477 return 0; 1478 1479 return bio_integrity(rq->bio); 1480 } 1481 1482 static inline void blk_queue_max_integrity_segments(struct request_queue *q, 1483 unsigned int segs) 1484 { 1485 q->limits.max_integrity_segments = segs; 1486 } 1487 1488 static inline unsigned short 1489 queue_max_integrity_segments(struct request_queue *q) 1490 { 1491 return q->limits.max_integrity_segments; 1492 } 1493 1494 #else /* CONFIG_BLK_DEV_INTEGRITY */ 1495 1496 struct bio; 1497 struct block_device; 1498 struct gendisk; 1499 struct blk_integrity; 1500 1501 static inline int blk_integrity_rq(struct request *rq) 1502 { 1503 return 0; 1504 } 1505 static inline int blk_rq_count_integrity_sg(struct request_queue *q, 1506 struct bio *b) 1507 { 1508 return 0; 1509 } 1510 static inline int blk_rq_map_integrity_sg(struct request_queue *q, 1511 struct bio *b, 1512 struct scatterlist *s) 1513 { 1514 return 0; 1515 } 1516 static inline struct blk_integrity *bdev_get_integrity(struct block_device *b) 1517 { 1518 return 0; 1519 } 1520 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk) 1521 { 1522 return NULL; 1523 } 1524 static inline int blk_integrity_compare(struct gendisk *a, struct gendisk *b) 1525 { 1526 return 0; 1527 } 1528 static inline int blk_integrity_register(struct gendisk *d, 1529 struct blk_integrity *b) 1530 { 1531 return 0; 1532 } 1533 static inline void blk_integrity_unregister(struct gendisk *d) 1534 { 1535 } 1536 static inline void blk_queue_max_integrity_segments(struct request_queue *q, 1537 unsigned int segs) 1538 { 1539 } 1540 static inline unsigned short queue_max_integrity_segments(struct request_queue *q) 1541 { 1542 return 0; 1543 } 1544 static inline int blk_integrity_merge_rq(struct request_queue *rq, 1545 struct request *r1, 1546 struct request *r2) 1547 { 1548 return 0; 1549 } 1550 static inline int blk_integrity_merge_bio(struct request_queue *rq, 1551 struct request *r, 1552 struct bio *b) 1553 { 1554 return 0; 1555 } 1556 static inline bool blk_integrity_is_initialized(struct gendisk *g) 1557 { 1558 return 0; 1559 } 1560 1561 #endif /* CONFIG_BLK_DEV_INTEGRITY */ 1562 1563 struct block_device_operations { 1564 int (*open) (struct block_device *, fmode_t); 1565 void (*release) (struct gendisk *, fmode_t); 1566 int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long); 1567 int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long); 1568 int (*direct_access) (struct block_device *, sector_t, 1569 void **, unsigned long *); 1570 unsigned int (*check_events) (struct gendisk *disk, 1571 unsigned int clearing); 1572 /* ->media_changed() is DEPRECATED, use ->check_events() instead */ 1573 int (*media_changed) (struct gendisk *); 1574 void (*unlock_native_capacity) (struct gendisk *); 1575 int (*revalidate_disk) (struct gendisk *); 1576 int (*getgeo)(struct block_device *, struct hd_geometry *); 1577 /* this callback is with swap_lock and sometimes page table lock held */ 1578 void (*swap_slot_free_notify) (struct block_device *, unsigned long); 1579 struct module *owner; 1580 }; 1581 1582 extern int __blkdev_driver_ioctl(struct block_device *, fmode_t, unsigned int, 1583 unsigned long); 1584 #else /* CONFIG_BLOCK */ 1585 /* 1586 * stubs for when the block layer is configured out 1587 */ 1588 #define buffer_heads_over_limit 0 1589 1590 static inline long nr_blockdev_pages(void) 1591 { 1592 return 0; 1593 } 1594 1595 struct blk_plug { 1596 }; 1597 1598 static inline void blk_start_plug(struct blk_plug *plug) 1599 { 1600 } 1601 1602 static inline void blk_finish_plug(struct blk_plug *plug) 1603 { 1604 } 1605 1606 static inline void blk_flush_plug(struct task_struct *task) 1607 { 1608 } 1609 1610 static inline void blk_schedule_flush_plug(struct task_struct *task) 1611 { 1612 } 1613 1614 1615 static inline bool blk_needs_flush_plug(struct task_struct *tsk) 1616 { 1617 return false; 1618 } 1619 1620 #endif /* CONFIG_BLOCK */ 1621 1622 #endif 1623