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_work; 102 unsigned long fifo_time; 103 }; 104 105 struct request_queue *q; 106 struct blk_mq_ctx *mq_ctx; 107 108 u64 cmd_flags; 109 enum rq_cmd_type_bits cmd_type; 110 unsigned long atomic_flags; 111 112 int cpu; 113 114 /* the following two fields are internal, NEVER access directly */ 115 unsigned int __data_len; /* total data len */ 116 sector_t __sector; /* sector cursor */ 117 118 struct bio *bio; 119 struct bio *biotail; 120 121 struct hlist_node hash; /* merge hash */ 122 /* 123 * The rb_node is only used inside the io scheduler, requests 124 * are pruned when moved to the dispatch queue. So let the 125 * completion_data share space with the rb_node. 126 */ 127 union { 128 struct rb_node rb_node; /* sort/lookup */ 129 void *completion_data; 130 }; 131 132 /* 133 * Three pointers are available for the IO schedulers, if they need 134 * more they have to dynamically allocate it. Flush requests are 135 * never put on the IO scheduler. So let the flush fields share 136 * space with the elevator data. 137 */ 138 union { 139 struct { 140 struct io_cq *icq; 141 void *priv[2]; 142 } elv; 143 144 struct { 145 unsigned int seq; 146 struct list_head list; 147 rq_end_io_fn *saved_end_io; 148 } flush; 149 }; 150 151 struct gendisk *rq_disk; 152 struct hd_struct *part; 153 unsigned long start_time; 154 #ifdef CONFIG_BLK_CGROUP 155 struct request_list *rl; /* rl this rq is alloced from */ 156 unsigned long long start_time_ns; 157 unsigned long long io_start_time_ns; /* when passed to hardware */ 158 #endif 159 /* Number of scatter-gather DMA addr+len pairs after 160 * physical address coalescing is performed. 161 */ 162 unsigned short nr_phys_segments; 163 #if defined(CONFIG_BLK_DEV_INTEGRITY) 164 unsigned short nr_integrity_segments; 165 #endif 166 167 unsigned short ioprio; 168 169 void *special; /* opaque pointer available for LLD use */ 170 char *buffer; /* kaddr of the current segment if available */ 171 172 int tag; 173 int errors; 174 175 /* 176 * when request is used as a packet command carrier 177 */ 178 unsigned char __cmd[BLK_MAX_CDB]; 179 unsigned char *cmd; 180 unsigned short cmd_len; 181 182 unsigned int extra_len; /* length of alignment and padding */ 183 unsigned int sense_len; 184 unsigned int resid_len; /* residual count */ 185 void *sense; 186 187 unsigned long deadline; 188 struct list_head timeout_list; 189 unsigned int timeout; 190 int retries; 191 192 /* 193 * completion callback. 194 */ 195 rq_end_io_fn *end_io; 196 void *end_io_data; 197 198 /* for bidi */ 199 struct request *next_rq; 200 }; 201 202 static inline unsigned short req_get_ioprio(struct request *req) 203 { 204 return req->ioprio; 205 } 206 207 /* 208 * State information carried for REQ_TYPE_PM_SUSPEND and REQ_TYPE_PM_RESUME 209 * requests. Some step values could eventually be made generic. 210 */ 211 struct request_pm_state 212 { 213 /* PM state machine step value, currently driver specific */ 214 int pm_step; 215 /* requested PM state value (S1, S2, S3, S4, ...) */ 216 u32 pm_state; 217 void* data; /* for driver use */ 218 }; 219 220 #include <linux/elevator.h> 221 222 struct blk_queue_ctx; 223 224 typedef void (request_fn_proc) (struct request_queue *q); 225 typedef void (make_request_fn) (struct request_queue *q, struct bio *bio); 226 typedef int (prep_rq_fn) (struct request_queue *, struct request *); 227 typedef void (unprep_rq_fn) (struct request_queue *, struct request *); 228 229 struct bio_vec; 230 struct bvec_merge_data { 231 struct block_device *bi_bdev; 232 sector_t bi_sector; 233 unsigned bi_size; 234 unsigned long bi_rw; 235 }; 236 typedef int (merge_bvec_fn) (struct request_queue *, struct bvec_merge_data *, 237 struct bio_vec *); 238 typedef void (softirq_done_fn)(struct request *); 239 typedef int (dma_drain_needed_fn)(struct request *); 240 typedef int (lld_busy_fn) (struct request_queue *q); 241 typedef int (bsg_job_fn) (struct bsg_job *); 242 243 enum blk_eh_timer_return { 244 BLK_EH_NOT_HANDLED, 245 BLK_EH_HANDLED, 246 BLK_EH_RESET_TIMER, 247 }; 248 249 typedef enum blk_eh_timer_return (rq_timed_out_fn)(struct request *); 250 251 enum blk_queue_state { 252 Queue_down, 253 Queue_up, 254 }; 255 256 struct blk_queue_tag { 257 struct request **tag_index; /* map of busy tags */ 258 unsigned long *tag_map; /* bit map of free/busy tags */ 259 int busy; /* current depth */ 260 int max_depth; /* what we will send to device */ 261 int real_max_depth; /* what the array can hold */ 262 atomic_t refcnt; /* map can be shared */ 263 }; 264 265 #define BLK_SCSI_MAX_CMDS (256) 266 #define BLK_SCSI_CMD_PER_LONG (BLK_SCSI_MAX_CMDS / (sizeof(long) * 8)) 267 268 struct queue_limits { 269 unsigned long bounce_pfn; 270 unsigned long seg_boundary_mask; 271 272 unsigned int max_hw_sectors; 273 unsigned int max_sectors; 274 unsigned int max_segment_size; 275 unsigned int physical_block_size; 276 unsigned int alignment_offset; 277 unsigned int io_min; 278 unsigned int io_opt; 279 unsigned int max_discard_sectors; 280 unsigned int max_write_same_sectors; 281 unsigned int discard_granularity; 282 unsigned int discard_alignment; 283 284 unsigned short logical_block_size; 285 unsigned short max_segments; 286 unsigned short max_integrity_segments; 287 288 unsigned char misaligned; 289 unsigned char discard_misaligned; 290 unsigned char cluster; 291 unsigned char discard_zeroes_data; 292 unsigned char raid_partial_stripes_expensive; 293 }; 294 295 struct request_queue { 296 /* 297 * Together with queue_head for cacheline sharing 298 */ 299 struct list_head queue_head; 300 struct request *last_merge; 301 struct elevator_queue *elevator; 302 int nr_rqs[2]; /* # allocated [a]sync rqs */ 303 int nr_rqs_elvpriv; /* # allocated rqs w/ elvpriv */ 304 305 /* 306 * If blkcg is not used, @q->root_rl serves all requests. If blkcg 307 * is used, root blkg allocates from @q->root_rl and all other 308 * blkgs from their own blkg->rl. Which one to use should be 309 * determined using bio_request_list(). 310 */ 311 struct request_list root_rl; 312 313 request_fn_proc *request_fn; 314 make_request_fn *make_request_fn; 315 prep_rq_fn *prep_rq_fn; 316 unprep_rq_fn *unprep_rq_fn; 317 merge_bvec_fn *merge_bvec_fn; 318 softirq_done_fn *softirq_done_fn; 319 rq_timed_out_fn *rq_timed_out_fn; 320 dma_drain_needed_fn *dma_drain_needed; 321 lld_busy_fn *lld_busy_fn; 322 323 struct blk_mq_ops *mq_ops; 324 325 unsigned int *mq_map; 326 327 /* sw queues */ 328 struct blk_mq_ctx *queue_ctx; 329 unsigned int nr_queues; 330 331 /* hw dispatch queues */ 332 struct blk_mq_hw_ctx **queue_hw_ctx; 333 unsigned int nr_hw_queues; 334 335 /* 336 * Dispatch queue sorting 337 */ 338 sector_t end_sector; 339 struct request *boundary_rq; 340 341 /* 342 * Delayed queue handling 343 */ 344 struct delayed_work delay_work; 345 346 struct backing_dev_info backing_dev_info; 347 348 /* 349 * The queue owner gets to use this for whatever they like. 350 * ll_rw_blk doesn't touch it. 351 */ 352 void *queuedata; 353 354 /* 355 * various queue flags, see QUEUE_* below 356 */ 357 unsigned long queue_flags; 358 359 /* 360 * ida allocated id for this queue. Used to index queues from 361 * ioctx. 362 */ 363 int id; 364 365 /* 366 * queue needs bounce pages for pages above this limit 367 */ 368 gfp_t bounce_gfp; 369 370 /* 371 * protects queue structures from reentrancy. ->__queue_lock should 372 * _never_ be used directly, it is queue private. always use 373 * ->queue_lock. 374 */ 375 spinlock_t __queue_lock; 376 spinlock_t *queue_lock; 377 378 /* 379 * queue kobject 380 */ 381 struct kobject kobj; 382 383 /* 384 * mq queue kobject 385 */ 386 struct kobject mq_kobj; 387 388 #ifdef CONFIG_PM_RUNTIME 389 struct device *dev; 390 int rpm_status; 391 unsigned int nr_pending; 392 #endif 393 394 /* 395 * queue settings 396 */ 397 unsigned long nr_requests; /* Max # of requests */ 398 unsigned int nr_congestion_on; 399 unsigned int nr_congestion_off; 400 unsigned int nr_batching; 401 402 unsigned int dma_drain_size; 403 void *dma_drain_buffer; 404 unsigned int dma_pad_mask; 405 unsigned int dma_alignment; 406 407 struct blk_queue_tag *queue_tags; 408 struct list_head tag_busy_list; 409 410 unsigned int nr_sorted; 411 unsigned int in_flight[2]; 412 /* 413 * Number of active block driver functions for which blk_drain_queue() 414 * must wait. Must be incremented around functions that unlock the 415 * queue_lock internally, e.g. scsi_request_fn(). 416 */ 417 unsigned int request_fn_active; 418 419 unsigned int rq_timeout; 420 struct timer_list timeout; 421 struct list_head timeout_list; 422 423 struct list_head icq_list; 424 #ifdef CONFIG_BLK_CGROUP 425 DECLARE_BITMAP (blkcg_pols, BLKCG_MAX_POLS); 426 struct blkcg_gq *root_blkg; 427 struct list_head blkg_list; 428 #endif 429 430 struct queue_limits limits; 431 432 /* 433 * sg stuff 434 */ 435 unsigned int sg_timeout; 436 unsigned int sg_reserved_size; 437 int node; 438 #ifdef CONFIG_BLK_DEV_IO_TRACE 439 struct blk_trace *blk_trace; 440 #endif 441 /* 442 * for flush operations 443 */ 444 unsigned int flush_flags; 445 unsigned int flush_not_queueable:1; 446 unsigned int flush_queue_delayed:1; 447 unsigned int flush_pending_idx:1; 448 unsigned int flush_running_idx:1; 449 unsigned long flush_pending_since; 450 struct list_head flush_queue[2]; 451 struct list_head flush_data_in_flight; 452 struct request *flush_rq; 453 spinlock_t mq_flush_lock; 454 455 struct mutex sysfs_lock; 456 457 int bypass_depth; 458 459 #if defined(CONFIG_BLK_DEV_BSG) 460 bsg_job_fn *bsg_job_fn; 461 int bsg_job_size; 462 struct bsg_class_device bsg_dev; 463 #endif 464 465 #ifdef CONFIG_BLK_DEV_THROTTLING 466 /* Throttle data */ 467 struct throtl_data *td; 468 #endif 469 struct rcu_head rcu_head; 470 wait_queue_head_t mq_freeze_wq; 471 struct percpu_counter mq_usage_counter; 472 struct list_head all_q_node; 473 }; 474 475 #define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */ 476 #define QUEUE_FLAG_STOPPED 2 /* queue is stopped */ 477 #define QUEUE_FLAG_SYNCFULL 3 /* read queue has been filled */ 478 #define QUEUE_FLAG_ASYNCFULL 4 /* write queue has been filled */ 479 #define QUEUE_FLAG_DYING 5 /* queue being torn down */ 480 #define QUEUE_FLAG_BYPASS 6 /* act as dumb FIFO queue */ 481 #define QUEUE_FLAG_BIDI 7 /* queue supports bidi requests */ 482 #define QUEUE_FLAG_NOMERGES 8 /* disable merge attempts */ 483 #define QUEUE_FLAG_SAME_COMP 9 /* complete on same CPU-group */ 484 #define QUEUE_FLAG_FAIL_IO 10 /* fake timeout */ 485 #define QUEUE_FLAG_STACKABLE 11 /* supports request stacking */ 486 #define QUEUE_FLAG_NONROT 12 /* non-rotational device (SSD) */ 487 #define QUEUE_FLAG_VIRT QUEUE_FLAG_NONROT /* paravirt device */ 488 #define QUEUE_FLAG_IO_STAT 13 /* do IO stats */ 489 #define QUEUE_FLAG_DISCARD 14 /* supports DISCARD */ 490 #define QUEUE_FLAG_NOXMERGES 15 /* No extended merges */ 491 #define QUEUE_FLAG_ADD_RANDOM 16 /* Contributes to random pool */ 492 #define QUEUE_FLAG_SECDISCARD 17 /* supports SECDISCARD */ 493 #define QUEUE_FLAG_SAME_FORCE 18 /* force complete on same CPU */ 494 #define QUEUE_FLAG_DEAD 19 /* queue tear-down finished */ 495 #define QUEUE_FLAG_INIT_DONE 20 /* queue is initialized */ 496 497 #define QUEUE_FLAG_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \ 498 (1 << QUEUE_FLAG_STACKABLE) | \ 499 (1 << QUEUE_FLAG_SAME_COMP) | \ 500 (1 << QUEUE_FLAG_ADD_RANDOM)) 501 502 #define QUEUE_FLAG_MQ_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \ 503 (1 << QUEUE_FLAG_SAME_COMP)) 504 505 static inline void queue_lockdep_assert_held(struct request_queue *q) 506 { 507 if (q->queue_lock) 508 lockdep_assert_held(q->queue_lock); 509 } 510 511 static inline void queue_flag_set_unlocked(unsigned int flag, 512 struct request_queue *q) 513 { 514 __set_bit(flag, &q->queue_flags); 515 } 516 517 static inline int queue_flag_test_and_clear(unsigned int flag, 518 struct request_queue *q) 519 { 520 queue_lockdep_assert_held(q); 521 522 if (test_bit(flag, &q->queue_flags)) { 523 __clear_bit(flag, &q->queue_flags); 524 return 1; 525 } 526 527 return 0; 528 } 529 530 static inline int queue_flag_test_and_set(unsigned int flag, 531 struct request_queue *q) 532 { 533 queue_lockdep_assert_held(q); 534 535 if (!test_bit(flag, &q->queue_flags)) { 536 __set_bit(flag, &q->queue_flags); 537 return 0; 538 } 539 540 return 1; 541 } 542 543 static inline void queue_flag_set(unsigned int flag, struct request_queue *q) 544 { 545 queue_lockdep_assert_held(q); 546 __set_bit(flag, &q->queue_flags); 547 } 548 549 static inline void queue_flag_clear_unlocked(unsigned int flag, 550 struct request_queue *q) 551 { 552 __clear_bit(flag, &q->queue_flags); 553 } 554 555 static inline int queue_in_flight(struct request_queue *q) 556 { 557 return q->in_flight[0] + q->in_flight[1]; 558 } 559 560 static inline void queue_flag_clear(unsigned int flag, struct request_queue *q) 561 { 562 queue_lockdep_assert_held(q); 563 __clear_bit(flag, &q->queue_flags); 564 } 565 566 #define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags) 567 #define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags) 568 #define blk_queue_dying(q) test_bit(QUEUE_FLAG_DYING, &(q)->queue_flags) 569 #define blk_queue_dead(q) test_bit(QUEUE_FLAG_DEAD, &(q)->queue_flags) 570 #define blk_queue_bypass(q) test_bit(QUEUE_FLAG_BYPASS, &(q)->queue_flags) 571 #define blk_queue_init_done(q) test_bit(QUEUE_FLAG_INIT_DONE, &(q)->queue_flags) 572 #define blk_queue_nomerges(q) test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags) 573 #define blk_queue_noxmerges(q) \ 574 test_bit(QUEUE_FLAG_NOXMERGES, &(q)->queue_flags) 575 #define blk_queue_nonrot(q) test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags) 576 #define blk_queue_io_stat(q) test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags) 577 #define blk_queue_add_random(q) test_bit(QUEUE_FLAG_ADD_RANDOM, &(q)->queue_flags) 578 #define blk_queue_stackable(q) \ 579 test_bit(QUEUE_FLAG_STACKABLE, &(q)->queue_flags) 580 #define blk_queue_discard(q) test_bit(QUEUE_FLAG_DISCARD, &(q)->queue_flags) 581 #define blk_queue_secdiscard(q) (blk_queue_discard(q) && \ 582 test_bit(QUEUE_FLAG_SECDISCARD, &(q)->queue_flags)) 583 584 #define blk_noretry_request(rq) \ 585 ((rq)->cmd_flags & (REQ_FAILFAST_DEV|REQ_FAILFAST_TRANSPORT| \ 586 REQ_FAILFAST_DRIVER)) 587 588 #define blk_account_rq(rq) \ 589 (((rq)->cmd_flags & REQ_STARTED) && \ 590 ((rq)->cmd_type == REQ_TYPE_FS)) 591 592 #define blk_pm_request(rq) \ 593 ((rq)->cmd_type == REQ_TYPE_PM_SUSPEND || \ 594 (rq)->cmd_type == REQ_TYPE_PM_RESUME) 595 596 #define blk_rq_cpu_valid(rq) ((rq)->cpu != -1) 597 #define blk_bidi_rq(rq) ((rq)->next_rq != NULL) 598 /* rq->queuelist of dequeued request must be list_empty() */ 599 #define blk_queued_rq(rq) (!list_empty(&(rq)->queuelist)) 600 601 #define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist) 602 603 #define rq_data_dir(rq) (((rq)->cmd_flags & 1) != 0) 604 605 static inline unsigned int blk_queue_cluster(struct request_queue *q) 606 { 607 return q->limits.cluster; 608 } 609 610 /* 611 * We regard a request as sync, if either a read or a sync write 612 */ 613 static inline bool rw_is_sync(unsigned int rw_flags) 614 { 615 return !(rw_flags & REQ_WRITE) || (rw_flags & REQ_SYNC); 616 } 617 618 static inline bool rq_is_sync(struct request *rq) 619 { 620 return rw_is_sync(rq->cmd_flags); 621 } 622 623 static inline bool blk_rl_full(struct request_list *rl, bool sync) 624 { 625 unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL; 626 627 return rl->flags & flag; 628 } 629 630 static inline void blk_set_rl_full(struct request_list *rl, bool sync) 631 { 632 unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL; 633 634 rl->flags |= flag; 635 } 636 637 static inline void blk_clear_rl_full(struct request_list *rl, bool sync) 638 { 639 unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL; 640 641 rl->flags &= ~flag; 642 } 643 644 static inline bool rq_mergeable(struct request *rq) 645 { 646 if (rq->cmd_type != REQ_TYPE_FS) 647 return false; 648 649 if (rq->cmd_flags & REQ_NOMERGE_FLAGS) 650 return false; 651 652 return true; 653 } 654 655 static inline bool blk_check_merge_flags(unsigned int flags1, 656 unsigned int flags2) 657 { 658 if ((flags1 & REQ_DISCARD) != (flags2 & REQ_DISCARD)) 659 return false; 660 661 if ((flags1 & REQ_SECURE) != (flags2 & REQ_SECURE)) 662 return false; 663 664 if ((flags1 & REQ_WRITE_SAME) != (flags2 & REQ_WRITE_SAME)) 665 return false; 666 667 return true; 668 } 669 670 static inline bool blk_write_same_mergeable(struct bio *a, struct bio *b) 671 { 672 if (bio_data(a) == bio_data(b)) 673 return true; 674 675 return false; 676 } 677 678 /* 679 * q->prep_rq_fn return values 680 */ 681 #define BLKPREP_OK 0 /* serve it */ 682 #define BLKPREP_KILL 1 /* fatal error, kill */ 683 #define BLKPREP_DEFER 2 /* leave on queue */ 684 685 extern unsigned long blk_max_low_pfn, blk_max_pfn; 686 687 /* 688 * standard bounce addresses: 689 * 690 * BLK_BOUNCE_HIGH : bounce all highmem pages 691 * BLK_BOUNCE_ANY : don't bounce anything 692 * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary 693 */ 694 695 #if BITS_PER_LONG == 32 696 #define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT) 697 #else 698 #define BLK_BOUNCE_HIGH -1ULL 699 #endif 700 #define BLK_BOUNCE_ANY (-1ULL) 701 #define BLK_BOUNCE_ISA (DMA_BIT_MASK(24)) 702 703 /* 704 * default timeout for SG_IO if none specified 705 */ 706 #define BLK_DEFAULT_SG_TIMEOUT (60 * HZ) 707 #define BLK_MIN_SG_TIMEOUT (7 * HZ) 708 709 #ifdef CONFIG_BOUNCE 710 extern int init_emergency_isa_pool(void); 711 extern void blk_queue_bounce(struct request_queue *q, struct bio **bio); 712 #else 713 static inline int init_emergency_isa_pool(void) 714 { 715 return 0; 716 } 717 static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio) 718 { 719 } 720 #endif /* CONFIG_MMU */ 721 722 struct rq_map_data { 723 struct page **pages; 724 int page_order; 725 int nr_entries; 726 unsigned long offset; 727 int null_mapped; 728 int from_user; 729 }; 730 731 struct req_iterator { 732 struct bvec_iter iter; 733 struct bio *bio; 734 }; 735 736 /* This should not be used directly - use rq_for_each_segment */ 737 #define for_each_bio(_bio) \ 738 for (; _bio; _bio = _bio->bi_next) 739 #define __rq_for_each_bio(_bio, rq) \ 740 if ((rq->bio)) \ 741 for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next) 742 743 #define rq_for_each_segment(bvl, _rq, _iter) \ 744 __rq_for_each_bio(_iter.bio, _rq) \ 745 bio_for_each_segment(bvl, _iter.bio, _iter.iter) 746 747 #define rq_iter_last(bvec, _iter) \ 748 (_iter.bio->bi_next == NULL && \ 749 bio_iter_last(bvec, _iter.iter)) 750 751 #ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 752 # error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform" 753 #endif 754 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 755 extern void rq_flush_dcache_pages(struct request *rq); 756 #else 757 static inline void rq_flush_dcache_pages(struct request *rq) 758 { 759 } 760 #endif 761 762 extern int blk_register_queue(struct gendisk *disk); 763 extern void blk_unregister_queue(struct gendisk *disk); 764 extern void generic_make_request(struct bio *bio); 765 extern void blk_rq_init(struct request_queue *q, struct request *rq); 766 extern void blk_put_request(struct request *); 767 extern void __blk_put_request(struct request_queue *, struct request *); 768 extern struct request *blk_get_request(struct request_queue *, int, gfp_t); 769 extern struct request *blk_make_request(struct request_queue *, struct bio *, 770 gfp_t); 771 extern void blk_requeue_request(struct request_queue *, struct request *); 772 extern void blk_add_request_payload(struct request *rq, struct page *page, 773 unsigned int len); 774 extern int blk_rq_check_limits(struct request_queue *q, struct request *rq); 775 extern int blk_lld_busy(struct request_queue *q); 776 extern int blk_rq_prep_clone(struct request *rq, struct request *rq_src, 777 struct bio_set *bs, gfp_t gfp_mask, 778 int (*bio_ctr)(struct bio *, struct bio *, void *), 779 void *data); 780 extern void blk_rq_unprep_clone(struct request *rq); 781 extern int blk_insert_cloned_request(struct request_queue *q, 782 struct request *rq); 783 extern void blk_delay_queue(struct request_queue *, unsigned long); 784 extern void blk_recount_segments(struct request_queue *, struct bio *); 785 extern int scsi_verify_blk_ioctl(struct block_device *, unsigned int); 786 extern int scsi_cmd_blk_ioctl(struct block_device *, fmode_t, 787 unsigned int, void __user *); 788 extern int scsi_cmd_ioctl(struct request_queue *, struct gendisk *, fmode_t, 789 unsigned int, void __user *); 790 extern int sg_scsi_ioctl(struct request_queue *, struct gendisk *, fmode_t, 791 struct scsi_ioctl_command __user *); 792 793 extern void blk_queue_bio(struct request_queue *q, struct bio *bio); 794 795 /* 796 * A queue has just exitted congestion. Note this in the global counter of 797 * congested queues, and wake up anyone who was waiting for requests to be 798 * put back. 799 */ 800 static inline void blk_clear_queue_congested(struct request_queue *q, int sync) 801 { 802 clear_bdi_congested(&q->backing_dev_info, sync); 803 } 804 805 /* 806 * A queue has just entered congestion. Flag that in the queue's VM-visible 807 * state flags and increment the global gounter of congested queues. 808 */ 809 static inline void blk_set_queue_congested(struct request_queue *q, int sync) 810 { 811 set_bdi_congested(&q->backing_dev_info, sync); 812 } 813 814 extern void blk_start_queue(struct request_queue *q); 815 extern void blk_stop_queue(struct request_queue *q); 816 extern void blk_sync_queue(struct request_queue *q); 817 extern void __blk_stop_queue(struct request_queue *q); 818 extern void __blk_run_queue(struct request_queue *q); 819 extern void blk_run_queue(struct request_queue *); 820 extern void blk_run_queue_async(struct request_queue *q); 821 extern int blk_rq_map_user(struct request_queue *, struct request *, 822 struct rq_map_data *, void __user *, unsigned long, 823 gfp_t); 824 extern int blk_rq_unmap_user(struct bio *); 825 extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, unsigned int, gfp_t); 826 extern int blk_rq_map_user_iov(struct request_queue *, struct request *, 827 struct rq_map_data *, struct sg_iovec *, int, 828 unsigned int, gfp_t); 829 extern int blk_execute_rq(struct request_queue *, struct gendisk *, 830 struct request *, int); 831 extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *, 832 struct request *, int, rq_end_io_fn *); 833 834 static inline struct request_queue *bdev_get_queue(struct block_device *bdev) 835 { 836 return bdev->bd_disk->queue; 837 } 838 839 /* 840 * blk_rq_pos() : the current sector 841 * blk_rq_bytes() : bytes left in the entire request 842 * blk_rq_cur_bytes() : bytes left in the current segment 843 * blk_rq_err_bytes() : bytes left till the next error boundary 844 * blk_rq_sectors() : sectors left in the entire request 845 * blk_rq_cur_sectors() : sectors left in the current segment 846 */ 847 static inline sector_t blk_rq_pos(const struct request *rq) 848 { 849 return rq->__sector; 850 } 851 852 static inline unsigned int blk_rq_bytes(const struct request *rq) 853 { 854 return rq->__data_len; 855 } 856 857 static inline int blk_rq_cur_bytes(const struct request *rq) 858 { 859 return rq->bio ? bio_cur_bytes(rq->bio) : 0; 860 } 861 862 extern unsigned int blk_rq_err_bytes(const struct request *rq); 863 864 static inline unsigned int blk_rq_sectors(const struct request *rq) 865 { 866 return blk_rq_bytes(rq) >> 9; 867 } 868 869 static inline unsigned int blk_rq_cur_sectors(const struct request *rq) 870 { 871 return blk_rq_cur_bytes(rq) >> 9; 872 } 873 874 static inline unsigned int blk_queue_get_max_sectors(struct request_queue *q, 875 unsigned int cmd_flags) 876 { 877 if (unlikely(cmd_flags & REQ_DISCARD)) 878 return min(q->limits.max_discard_sectors, UINT_MAX >> 9); 879 880 if (unlikely(cmd_flags & REQ_WRITE_SAME)) 881 return q->limits.max_write_same_sectors; 882 883 return q->limits.max_sectors; 884 } 885 886 static inline unsigned int blk_rq_get_max_sectors(struct request *rq) 887 { 888 struct request_queue *q = rq->q; 889 890 if (unlikely(rq->cmd_type == REQ_TYPE_BLOCK_PC)) 891 return q->limits.max_hw_sectors; 892 893 return blk_queue_get_max_sectors(q, rq->cmd_flags); 894 } 895 896 static inline unsigned int blk_rq_count_bios(struct request *rq) 897 { 898 unsigned int nr_bios = 0; 899 struct bio *bio; 900 901 __rq_for_each_bio(bio, rq) 902 nr_bios++; 903 904 return nr_bios; 905 } 906 907 /* 908 * Request issue related functions. 909 */ 910 extern struct request *blk_peek_request(struct request_queue *q); 911 extern void blk_start_request(struct request *rq); 912 extern struct request *blk_fetch_request(struct request_queue *q); 913 914 /* 915 * Request completion related functions. 916 * 917 * blk_update_request() completes given number of bytes and updates 918 * the request without completing it. 919 * 920 * blk_end_request() and friends. __blk_end_request() must be called 921 * with the request queue spinlock acquired. 922 * 923 * Several drivers define their own end_request and call 924 * blk_end_request() for parts of the original function. 925 * This prevents code duplication in drivers. 926 */ 927 extern bool blk_update_request(struct request *rq, int error, 928 unsigned int nr_bytes); 929 extern bool blk_end_request(struct request *rq, int error, 930 unsigned int nr_bytes); 931 extern void blk_end_request_all(struct request *rq, int error); 932 extern bool blk_end_request_cur(struct request *rq, int error); 933 extern bool blk_end_request_err(struct request *rq, int error); 934 extern bool __blk_end_request(struct request *rq, int error, 935 unsigned int nr_bytes); 936 extern void __blk_end_request_all(struct request *rq, int error); 937 extern bool __blk_end_request_cur(struct request *rq, int error); 938 extern bool __blk_end_request_err(struct request *rq, int error); 939 940 extern void blk_complete_request(struct request *); 941 extern void __blk_complete_request(struct request *); 942 extern void blk_abort_request(struct request *); 943 extern void blk_unprep_request(struct request *); 944 945 /* 946 * Access functions for manipulating queue properties 947 */ 948 extern struct request_queue *blk_init_queue_node(request_fn_proc *rfn, 949 spinlock_t *lock, int node_id); 950 extern struct request_queue *blk_init_queue(request_fn_proc *, spinlock_t *); 951 extern struct request_queue *blk_init_allocated_queue(struct request_queue *, 952 request_fn_proc *, spinlock_t *); 953 extern void blk_cleanup_queue(struct request_queue *); 954 extern void blk_queue_make_request(struct request_queue *, make_request_fn *); 955 extern void blk_queue_bounce_limit(struct request_queue *, u64); 956 extern void blk_limits_max_hw_sectors(struct queue_limits *, unsigned int); 957 extern void blk_queue_max_hw_sectors(struct request_queue *, unsigned int); 958 extern void blk_queue_max_segments(struct request_queue *, unsigned short); 959 extern void blk_queue_max_segment_size(struct request_queue *, unsigned int); 960 extern void blk_queue_max_discard_sectors(struct request_queue *q, 961 unsigned int max_discard_sectors); 962 extern void blk_queue_max_write_same_sectors(struct request_queue *q, 963 unsigned int max_write_same_sectors); 964 extern void blk_queue_logical_block_size(struct request_queue *, unsigned short); 965 extern void blk_queue_physical_block_size(struct request_queue *, unsigned int); 966 extern void blk_queue_alignment_offset(struct request_queue *q, 967 unsigned int alignment); 968 extern void blk_limits_io_min(struct queue_limits *limits, unsigned int min); 969 extern void blk_queue_io_min(struct request_queue *q, unsigned int min); 970 extern void blk_limits_io_opt(struct queue_limits *limits, unsigned int opt); 971 extern void blk_queue_io_opt(struct request_queue *q, unsigned int opt); 972 extern void blk_set_default_limits(struct queue_limits *lim); 973 extern void blk_set_stacking_limits(struct queue_limits *lim); 974 extern int blk_stack_limits(struct queue_limits *t, struct queue_limits *b, 975 sector_t offset); 976 extern int bdev_stack_limits(struct queue_limits *t, struct block_device *bdev, 977 sector_t offset); 978 extern void disk_stack_limits(struct gendisk *disk, struct block_device *bdev, 979 sector_t offset); 980 extern void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b); 981 extern void blk_queue_dma_pad(struct request_queue *, unsigned int); 982 extern void blk_queue_update_dma_pad(struct request_queue *, unsigned int); 983 extern int blk_queue_dma_drain(struct request_queue *q, 984 dma_drain_needed_fn *dma_drain_needed, 985 void *buf, unsigned int size); 986 extern void blk_queue_lld_busy(struct request_queue *q, lld_busy_fn *fn); 987 extern void blk_queue_segment_boundary(struct request_queue *, unsigned long); 988 extern void blk_queue_prep_rq(struct request_queue *, prep_rq_fn *pfn); 989 extern void blk_queue_unprep_rq(struct request_queue *, unprep_rq_fn *ufn); 990 extern void blk_queue_merge_bvec(struct request_queue *, merge_bvec_fn *); 991 extern void blk_queue_dma_alignment(struct request_queue *, int); 992 extern void blk_queue_update_dma_alignment(struct request_queue *, int); 993 extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *); 994 extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *); 995 extern void blk_queue_rq_timeout(struct request_queue *, unsigned int); 996 extern void blk_queue_flush(struct request_queue *q, unsigned int flush); 997 extern void blk_queue_flush_queueable(struct request_queue *q, bool queueable); 998 extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev); 999 1000 extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *); 1001 extern int blk_bio_map_sg(struct request_queue *q, struct bio *bio, 1002 struct scatterlist *sglist); 1003 extern void blk_dump_rq_flags(struct request *, char *); 1004 extern long nr_blockdev_pages(void); 1005 1006 bool __must_check blk_get_queue(struct request_queue *); 1007 struct request_queue *blk_alloc_queue(gfp_t); 1008 struct request_queue *blk_alloc_queue_node(gfp_t, int); 1009 extern void blk_put_queue(struct request_queue *); 1010 1011 /* 1012 * block layer runtime pm functions 1013 */ 1014 #ifdef CONFIG_PM_RUNTIME 1015 extern void blk_pm_runtime_init(struct request_queue *q, struct device *dev); 1016 extern int blk_pre_runtime_suspend(struct request_queue *q); 1017 extern void blk_post_runtime_suspend(struct request_queue *q, int err); 1018 extern void blk_pre_runtime_resume(struct request_queue *q); 1019 extern void blk_post_runtime_resume(struct request_queue *q, int err); 1020 #else 1021 static inline void blk_pm_runtime_init(struct request_queue *q, 1022 struct device *dev) {} 1023 static inline int blk_pre_runtime_suspend(struct request_queue *q) 1024 { 1025 return -ENOSYS; 1026 } 1027 static inline void blk_post_runtime_suspend(struct request_queue *q, int err) {} 1028 static inline void blk_pre_runtime_resume(struct request_queue *q) {} 1029 static inline void blk_post_runtime_resume(struct request_queue *q, int err) {} 1030 #endif 1031 1032 /* 1033 * blk_plug permits building a queue of related requests by holding the I/O 1034 * fragments for a short period. This allows merging of sequential requests 1035 * into single larger request. As the requests are moved from a per-task list to 1036 * the device's request_queue in a batch, this results in improved scalability 1037 * as the lock contention for request_queue lock is reduced. 1038 * 1039 * It is ok not to disable preemption when adding the request to the plug list 1040 * or when attempting a merge, because blk_schedule_flush_list() will only flush 1041 * the plug list when the task sleeps by itself. For details, please see 1042 * schedule() where blk_schedule_flush_plug() is called. 1043 */ 1044 struct blk_plug { 1045 unsigned long magic; /* detect uninitialized use-cases */ 1046 struct list_head list; /* requests */ 1047 struct list_head mq_list; /* blk-mq requests */ 1048 struct list_head cb_list; /* md requires an unplug callback */ 1049 }; 1050 #define BLK_MAX_REQUEST_COUNT 16 1051 1052 struct blk_plug_cb; 1053 typedef void (*blk_plug_cb_fn)(struct blk_plug_cb *, bool); 1054 struct blk_plug_cb { 1055 struct list_head list; 1056 blk_plug_cb_fn callback; 1057 void *data; 1058 }; 1059 extern struct blk_plug_cb *blk_check_plugged(blk_plug_cb_fn unplug, 1060 void *data, int size); 1061 extern void blk_start_plug(struct blk_plug *); 1062 extern void blk_finish_plug(struct blk_plug *); 1063 extern void blk_flush_plug_list(struct blk_plug *, bool); 1064 1065 static inline void blk_flush_plug(struct task_struct *tsk) 1066 { 1067 struct blk_plug *plug = tsk->plug; 1068 1069 if (plug) 1070 blk_flush_plug_list(plug, false); 1071 } 1072 1073 static inline void blk_schedule_flush_plug(struct task_struct *tsk) 1074 { 1075 struct blk_plug *plug = tsk->plug; 1076 1077 if (plug) 1078 blk_flush_plug_list(plug, true); 1079 } 1080 1081 static inline bool blk_needs_flush_plug(struct task_struct *tsk) 1082 { 1083 struct blk_plug *plug = tsk->plug; 1084 1085 return plug && 1086 (!list_empty(&plug->list) || 1087 !list_empty(&plug->mq_list) || 1088 !list_empty(&plug->cb_list)); 1089 } 1090 1091 /* 1092 * tag stuff 1093 */ 1094 #define blk_rq_tagged(rq) ((rq)->cmd_flags & REQ_QUEUED) 1095 extern int blk_queue_start_tag(struct request_queue *, struct request *); 1096 extern struct request *blk_queue_find_tag(struct request_queue *, int); 1097 extern void blk_queue_end_tag(struct request_queue *, struct request *); 1098 extern int blk_queue_init_tags(struct request_queue *, int, struct blk_queue_tag *); 1099 extern void blk_queue_free_tags(struct request_queue *); 1100 extern int blk_queue_resize_tags(struct request_queue *, int); 1101 extern void blk_queue_invalidate_tags(struct request_queue *); 1102 extern struct blk_queue_tag *blk_init_tags(int); 1103 extern void blk_free_tags(struct blk_queue_tag *); 1104 1105 static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt, 1106 int tag) 1107 { 1108 if (unlikely(bqt == NULL || tag >= bqt->real_max_depth)) 1109 return NULL; 1110 return bqt->tag_index[tag]; 1111 } 1112 1113 #define BLKDEV_DISCARD_SECURE 0x01 /* secure discard */ 1114 1115 extern int blkdev_issue_flush(struct block_device *, gfp_t, sector_t *); 1116 extern int blkdev_issue_discard(struct block_device *bdev, sector_t sector, 1117 sector_t nr_sects, gfp_t gfp_mask, unsigned long flags); 1118 extern int blkdev_issue_write_same(struct block_device *bdev, sector_t sector, 1119 sector_t nr_sects, gfp_t gfp_mask, struct page *page); 1120 extern int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector, 1121 sector_t nr_sects, gfp_t gfp_mask); 1122 static inline int sb_issue_discard(struct super_block *sb, sector_t block, 1123 sector_t nr_blocks, gfp_t gfp_mask, unsigned long flags) 1124 { 1125 return blkdev_issue_discard(sb->s_bdev, block << (sb->s_blocksize_bits - 9), 1126 nr_blocks << (sb->s_blocksize_bits - 9), 1127 gfp_mask, flags); 1128 } 1129 static inline int sb_issue_zeroout(struct super_block *sb, sector_t block, 1130 sector_t nr_blocks, gfp_t gfp_mask) 1131 { 1132 return blkdev_issue_zeroout(sb->s_bdev, 1133 block << (sb->s_blocksize_bits - 9), 1134 nr_blocks << (sb->s_blocksize_bits - 9), 1135 gfp_mask); 1136 } 1137 1138 extern int blk_verify_command(unsigned char *cmd, fmode_t has_write_perm); 1139 1140 enum blk_default_limits { 1141 BLK_MAX_SEGMENTS = 128, 1142 BLK_SAFE_MAX_SECTORS = 255, 1143 BLK_DEF_MAX_SECTORS = 1024, 1144 BLK_MAX_SEGMENT_SIZE = 65536, 1145 BLK_SEG_BOUNDARY_MASK = 0xFFFFFFFFUL, 1146 }; 1147 1148 #define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist) 1149 1150 static inline unsigned long queue_bounce_pfn(struct request_queue *q) 1151 { 1152 return q->limits.bounce_pfn; 1153 } 1154 1155 static inline unsigned long queue_segment_boundary(struct request_queue *q) 1156 { 1157 return q->limits.seg_boundary_mask; 1158 } 1159 1160 static inline unsigned int queue_max_sectors(struct request_queue *q) 1161 { 1162 return q->limits.max_sectors; 1163 } 1164 1165 static inline unsigned int queue_max_hw_sectors(struct request_queue *q) 1166 { 1167 return q->limits.max_hw_sectors; 1168 } 1169 1170 static inline unsigned short queue_max_segments(struct request_queue *q) 1171 { 1172 return q->limits.max_segments; 1173 } 1174 1175 static inline unsigned int queue_max_segment_size(struct request_queue *q) 1176 { 1177 return q->limits.max_segment_size; 1178 } 1179 1180 static inline unsigned short queue_logical_block_size(struct request_queue *q) 1181 { 1182 int retval = 512; 1183 1184 if (q && q->limits.logical_block_size) 1185 retval = q->limits.logical_block_size; 1186 1187 return retval; 1188 } 1189 1190 static inline unsigned short bdev_logical_block_size(struct block_device *bdev) 1191 { 1192 return queue_logical_block_size(bdev_get_queue(bdev)); 1193 } 1194 1195 static inline unsigned int queue_physical_block_size(struct request_queue *q) 1196 { 1197 return q->limits.physical_block_size; 1198 } 1199 1200 static inline unsigned int bdev_physical_block_size(struct block_device *bdev) 1201 { 1202 return queue_physical_block_size(bdev_get_queue(bdev)); 1203 } 1204 1205 static inline unsigned int queue_io_min(struct request_queue *q) 1206 { 1207 return q->limits.io_min; 1208 } 1209 1210 static inline int bdev_io_min(struct block_device *bdev) 1211 { 1212 return queue_io_min(bdev_get_queue(bdev)); 1213 } 1214 1215 static inline unsigned int queue_io_opt(struct request_queue *q) 1216 { 1217 return q->limits.io_opt; 1218 } 1219 1220 static inline int bdev_io_opt(struct block_device *bdev) 1221 { 1222 return queue_io_opt(bdev_get_queue(bdev)); 1223 } 1224 1225 static inline int queue_alignment_offset(struct request_queue *q) 1226 { 1227 if (q->limits.misaligned) 1228 return -1; 1229 1230 return q->limits.alignment_offset; 1231 } 1232 1233 static inline int queue_limit_alignment_offset(struct queue_limits *lim, sector_t sector) 1234 { 1235 unsigned int granularity = max(lim->physical_block_size, lim->io_min); 1236 unsigned int alignment = (sector << 9) & (granularity - 1); 1237 1238 return (granularity + lim->alignment_offset - alignment) 1239 & (granularity - 1); 1240 } 1241 1242 static inline int bdev_alignment_offset(struct block_device *bdev) 1243 { 1244 struct request_queue *q = bdev_get_queue(bdev); 1245 1246 if (q->limits.misaligned) 1247 return -1; 1248 1249 if (bdev != bdev->bd_contains) 1250 return bdev->bd_part->alignment_offset; 1251 1252 return q->limits.alignment_offset; 1253 } 1254 1255 static inline int queue_discard_alignment(struct request_queue *q) 1256 { 1257 if (q->limits.discard_misaligned) 1258 return -1; 1259 1260 return q->limits.discard_alignment; 1261 } 1262 1263 static inline int queue_limit_discard_alignment(struct queue_limits *lim, sector_t sector) 1264 { 1265 unsigned int alignment, granularity, offset; 1266 1267 if (!lim->max_discard_sectors) 1268 return 0; 1269 1270 /* Why are these in bytes, not sectors? */ 1271 alignment = lim->discard_alignment >> 9; 1272 granularity = lim->discard_granularity >> 9; 1273 if (!granularity) 1274 return 0; 1275 1276 /* Offset of the partition start in 'granularity' sectors */ 1277 offset = sector_div(sector, granularity); 1278 1279 /* And why do we do this modulus *again* in blkdev_issue_discard()? */ 1280 offset = (granularity + alignment - offset) % granularity; 1281 1282 /* Turn it back into bytes, gaah */ 1283 return offset << 9; 1284 } 1285 1286 static inline int bdev_discard_alignment(struct block_device *bdev) 1287 { 1288 struct request_queue *q = bdev_get_queue(bdev); 1289 1290 if (bdev != bdev->bd_contains) 1291 return bdev->bd_part->discard_alignment; 1292 1293 return q->limits.discard_alignment; 1294 } 1295 1296 static inline unsigned int queue_discard_zeroes_data(struct request_queue *q) 1297 { 1298 if (q->limits.max_discard_sectors && q->limits.discard_zeroes_data == 1) 1299 return 1; 1300 1301 return 0; 1302 } 1303 1304 static inline unsigned int bdev_discard_zeroes_data(struct block_device *bdev) 1305 { 1306 return queue_discard_zeroes_data(bdev_get_queue(bdev)); 1307 } 1308 1309 static inline unsigned int bdev_write_same(struct block_device *bdev) 1310 { 1311 struct request_queue *q = bdev_get_queue(bdev); 1312 1313 if (q) 1314 return q->limits.max_write_same_sectors; 1315 1316 return 0; 1317 } 1318 1319 static inline int queue_dma_alignment(struct request_queue *q) 1320 { 1321 return q ? q->dma_alignment : 511; 1322 } 1323 1324 static inline int blk_rq_aligned(struct request_queue *q, unsigned long addr, 1325 unsigned int len) 1326 { 1327 unsigned int alignment = queue_dma_alignment(q) | q->dma_pad_mask; 1328 return !(addr & alignment) && !(len & alignment); 1329 } 1330 1331 /* assumes size > 256 */ 1332 static inline unsigned int blksize_bits(unsigned int size) 1333 { 1334 unsigned int bits = 8; 1335 do { 1336 bits++; 1337 size >>= 1; 1338 } while (size > 256); 1339 return bits; 1340 } 1341 1342 static inline unsigned int block_size(struct block_device *bdev) 1343 { 1344 return bdev->bd_block_size; 1345 } 1346 1347 static inline bool queue_flush_queueable(struct request_queue *q) 1348 { 1349 return !q->flush_not_queueable; 1350 } 1351 1352 typedef struct {struct page *v;} Sector; 1353 1354 unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *); 1355 1356 static inline void put_dev_sector(Sector p) 1357 { 1358 page_cache_release(p.v); 1359 } 1360 1361 struct work_struct; 1362 int kblockd_schedule_work(struct request_queue *q, struct work_struct *work); 1363 int kblockd_schedule_delayed_work(struct request_queue *q, struct delayed_work *dwork, unsigned long delay); 1364 1365 #ifdef CONFIG_BLK_CGROUP 1366 /* 1367 * This should not be using sched_clock(). A real patch is in progress 1368 * to fix this up, until that is in place we need to disable preemption 1369 * around sched_clock() in this function and set_io_start_time_ns(). 1370 */ 1371 static inline void set_start_time_ns(struct request *req) 1372 { 1373 preempt_disable(); 1374 req->start_time_ns = sched_clock(); 1375 preempt_enable(); 1376 } 1377 1378 static inline void set_io_start_time_ns(struct request *req) 1379 { 1380 preempt_disable(); 1381 req->io_start_time_ns = sched_clock(); 1382 preempt_enable(); 1383 } 1384 1385 static inline uint64_t rq_start_time_ns(struct request *req) 1386 { 1387 return req->start_time_ns; 1388 } 1389 1390 static inline uint64_t rq_io_start_time_ns(struct request *req) 1391 { 1392 return req->io_start_time_ns; 1393 } 1394 #else 1395 static inline void set_start_time_ns(struct request *req) {} 1396 static inline void set_io_start_time_ns(struct request *req) {} 1397 static inline uint64_t rq_start_time_ns(struct request *req) 1398 { 1399 return 0; 1400 } 1401 static inline uint64_t rq_io_start_time_ns(struct request *req) 1402 { 1403 return 0; 1404 } 1405 #endif 1406 1407 #define MODULE_ALIAS_BLOCKDEV(major,minor) \ 1408 MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor)) 1409 #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \ 1410 MODULE_ALIAS("block-major-" __stringify(major) "-*") 1411 1412 #if defined(CONFIG_BLK_DEV_INTEGRITY) 1413 1414 #define INTEGRITY_FLAG_READ 2 /* verify data integrity on read */ 1415 #define INTEGRITY_FLAG_WRITE 4 /* generate data integrity on write */ 1416 1417 struct blk_integrity_exchg { 1418 void *prot_buf; 1419 void *data_buf; 1420 sector_t sector; 1421 unsigned int data_size; 1422 unsigned short sector_size; 1423 const char *disk_name; 1424 }; 1425 1426 typedef void (integrity_gen_fn) (struct blk_integrity_exchg *); 1427 typedef int (integrity_vrfy_fn) (struct blk_integrity_exchg *); 1428 typedef void (integrity_set_tag_fn) (void *, void *, unsigned int); 1429 typedef void (integrity_get_tag_fn) (void *, void *, unsigned int); 1430 1431 struct blk_integrity { 1432 integrity_gen_fn *generate_fn; 1433 integrity_vrfy_fn *verify_fn; 1434 integrity_set_tag_fn *set_tag_fn; 1435 integrity_get_tag_fn *get_tag_fn; 1436 1437 unsigned short flags; 1438 unsigned short tuple_size; 1439 unsigned short sector_size; 1440 unsigned short tag_size; 1441 1442 const char *name; 1443 1444 struct kobject kobj; 1445 }; 1446 1447 extern bool blk_integrity_is_initialized(struct gendisk *); 1448 extern int blk_integrity_register(struct gendisk *, struct blk_integrity *); 1449 extern void blk_integrity_unregister(struct gendisk *); 1450 extern int blk_integrity_compare(struct gendisk *, struct gendisk *); 1451 extern int blk_rq_map_integrity_sg(struct request_queue *, struct bio *, 1452 struct scatterlist *); 1453 extern int blk_rq_count_integrity_sg(struct request_queue *, struct bio *); 1454 extern int blk_integrity_merge_rq(struct request_queue *, struct request *, 1455 struct request *); 1456 extern int blk_integrity_merge_bio(struct request_queue *, struct request *, 1457 struct bio *); 1458 1459 static inline 1460 struct blk_integrity *bdev_get_integrity(struct block_device *bdev) 1461 { 1462 return bdev->bd_disk->integrity; 1463 } 1464 1465 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk) 1466 { 1467 return disk->integrity; 1468 } 1469 1470 static inline int blk_integrity_rq(struct request *rq) 1471 { 1472 if (rq->bio == NULL) 1473 return 0; 1474 1475 return bio_integrity(rq->bio); 1476 } 1477 1478 static inline void blk_queue_max_integrity_segments(struct request_queue *q, 1479 unsigned int segs) 1480 { 1481 q->limits.max_integrity_segments = segs; 1482 } 1483 1484 static inline unsigned short 1485 queue_max_integrity_segments(struct request_queue *q) 1486 { 1487 return q->limits.max_integrity_segments; 1488 } 1489 1490 #else /* CONFIG_BLK_DEV_INTEGRITY */ 1491 1492 struct bio; 1493 struct block_device; 1494 struct gendisk; 1495 struct blk_integrity; 1496 1497 static inline int blk_integrity_rq(struct request *rq) 1498 { 1499 return 0; 1500 } 1501 static inline int blk_rq_count_integrity_sg(struct request_queue *q, 1502 struct bio *b) 1503 { 1504 return 0; 1505 } 1506 static inline int blk_rq_map_integrity_sg(struct request_queue *q, 1507 struct bio *b, 1508 struct scatterlist *s) 1509 { 1510 return 0; 1511 } 1512 static inline struct blk_integrity *bdev_get_integrity(struct block_device *b) 1513 { 1514 return 0; 1515 } 1516 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk) 1517 { 1518 return NULL; 1519 } 1520 static inline int blk_integrity_compare(struct gendisk *a, struct gendisk *b) 1521 { 1522 return 0; 1523 } 1524 static inline int blk_integrity_register(struct gendisk *d, 1525 struct blk_integrity *b) 1526 { 1527 return 0; 1528 } 1529 static inline void blk_integrity_unregister(struct gendisk *d) 1530 { 1531 } 1532 static inline void blk_queue_max_integrity_segments(struct request_queue *q, 1533 unsigned int segs) 1534 { 1535 } 1536 static inline unsigned short queue_max_integrity_segments(struct request_queue *q) 1537 { 1538 return 0; 1539 } 1540 static inline int blk_integrity_merge_rq(struct request_queue *rq, 1541 struct request *r1, 1542 struct request *r2) 1543 { 1544 return 0; 1545 } 1546 static inline int blk_integrity_merge_bio(struct request_queue *rq, 1547 struct request *r, 1548 struct bio *b) 1549 { 1550 return 0; 1551 } 1552 static inline bool blk_integrity_is_initialized(struct gendisk *g) 1553 { 1554 return 0; 1555 } 1556 1557 #endif /* CONFIG_BLK_DEV_INTEGRITY */ 1558 1559 struct block_device_operations { 1560 int (*open) (struct block_device *, fmode_t); 1561 void (*release) (struct gendisk *, fmode_t); 1562 int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long); 1563 int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long); 1564 int (*direct_access) (struct block_device *, sector_t, 1565 void **, unsigned long *); 1566 unsigned int (*check_events) (struct gendisk *disk, 1567 unsigned int clearing); 1568 /* ->media_changed() is DEPRECATED, use ->check_events() instead */ 1569 int (*media_changed) (struct gendisk *); 1570 void (*unlock_native_capacity) (struct gendisk *); 1571 int (*revalidate_disk) (struct gendisk *); 1572 int (*getgeo)(struct block_device *, struct hd_geometry *); 1573 /* this callback is with swap_lock and sometimes page table lock held */ 1574 void (*swap_slot_free_notify) (struct block_device *, unsigned long); 1575 struct module *owner; 1576 }; 1577 1578 extern int __blkdev_driver_ioctl(struct block_device *, fmode_t, unsigned int, 1579 unsigned long); 1580 #else /* CONFIG_BLOCK */ 1581 /* 1582 * stubs for when the block layer is configured out 1583 */ 1584 #define buffer_heads_over_limit 0 1585 1586 static inline long nr_blockdev_pages(void) 1587 { 1588 return 0; 1589 } 1590 1591 struct blk_plug { 1592 }; 1593 1594 static inline void blk_start_plug(struct blk_plug *plug) 1595 { 1596 } 1597 1598 static inline void blk_finish_plug(struct blk_plug *plug) 1599 { 1600 } 1601 1602 static inline void blk_flush_plug(struct task_struct *task) 1603 { 1604 } 1605 1606 static inline void blk_schedule_flush_plug(struct task_struct *task) 1607 { 1608 } 1609 1610 1611 static inline bool blk_needs_flush_plug(struct task_struct *tsk) 1612 { 1613 return false; 1614 } 1615 1616 #endif /* CONFIG_BLOCK */ 1617 1618 #endif 1619