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/timer.h> 12 #include <linux/workqueue.h> 13 #include <linux/pagemap.h> 14 #include <linux/backing-dev.h> 15 #include <linux/wait.h> 16 #include <linux/mempool.h> 17 #include <linux/bio.h> 18 #include <linux/stringify.h> 19 #include <linux/gfp.h> 20 #include <linux/bsg.h> 21 #include <linux/smp.h> 22 #include <linux/rcupdate.h> 23 24 #include <asm/scatterlist.h> 25 26 struct module; 27 struct scsi_ioctl_command; 28 29 struct request_queue; 30 struct elevator_queue; 31 struct request_pm_state; 32 struct blk_trace; 33 struct request; 34 struct sg_io_hdr; 35 struct bsg_job; 36 struct blkcg_gq; 37 38 #define BLKDEV_MIN_RQ 4 39 #define BLKDEV_MAX_RQ 128 /* Default maximum */ 40 41 /* 42 * Maximum number of blkcg policies allowed to be registered concurrently. 43 * Defined here to simplify include dependency. 44 */ 45 #define BLKCG_MAX_POLS 2 46 47 struct request; 48 typedef void (rq_end_io_fn)(struct request *, int); 49 50 #define BLK_RL_SYNCFULL (1U << 0) 51 #define BLK_RL_ASYNCFULL (1U << 1) 52 53 struct request_list { 54 struct request_queue *q; /* the queue this rl belongs to */ 55 #ifdef CONFIG_BLK_CGROUP 56 struct blkcg_gq *blkg; /* blkg this request pool belongs to */ 57 #endif 58 /* 59 * count[], starved[], and wait[] are indexed by 60 * BLK_RW_SYNC/BLK_RW_ASYNC 61 */ 62 int count[2]; 63 int starved[2]; 64 mempool_t *rq_pool; 65 wait_queue_head_t wait[2]; 66 unsigned int flags; 67 }; 68 69 /* 70 * request command types 71 */ 72 enum rq_cmd_type_bits { 73 REQ_TYPE_FS = 1, /* fs request */ 74 REQ_TYPE_BLOCK_PC, /* scsi command */ 75 REQ_TYPE_SENSE, /* sense request */ 76 REQ_TYPE_PM_SUSPEND, /* suspend request */ 77 REQ_TYPE_PM_RESUME, /* resume request */ 78 REQ_TYPE_PM_SHUTDOWN, /* shutdown request */ 79 REQ_TYPE_SPECIAL, /* driver defined type */ 80 /* 81 * for ATA/ATAPI devices. this really doesn't belong here, ide should 82 * use REQ_TYPE_SPECIAL and use rq->cmd[0] with the range of driver 83 * private REQ_LB opcodes to differentiate what type of request this is 84 */ 85 REQ_TYPE_ATA_TASKFILE, 86 REQ_TYPE_ATA_PC, 87 }; 88 89 #define BLK_MAX_CDB 16 90 91 /* 92 * try to put the fields that are referenced together in the same cacheline. 93 * if you modify this structure, be sure to check block/blk-core.c:blk_rq_init() 94 * as well! 95 */ 96 struct request { 97 struct list_head queuelist; 98 struct call_single_data csd; 99 100 struct request_queue *q; 101 102 unsigned int cmd_flags; 103 enum rq_cmd_type_bits cmd_type; 104 unsigned long atomic_flags; 105 106 int cpu; 107 108 /* the following two fields are internal, NEVER access directly */ 109 unsigned int __data_len; /* total data len */ 110 sector_t __sector; /* sector cursor */ 111 112 struct bio *bio; 113 struct bio *biotail; 114 115 struct hlist_node hash; /* merge hash */ 116 /* 117 * The rb_node is only used inside the io scheduler, requests 118 * are pruned when moved to the dispatch queue. So let the 119 * completion_data share space with the rb_node. 120 */ 121 union { 122 struct rb_node rb_node; /* sort/lookup */ 123 void *completion_data; 124 }; 125 126 /* 127 * Three pointers are available for the IO schedulers, if they need 128 * more they have to dynamically allocate it. Flush requests are 129 * never put on the IO scheduler. So let the flush fields share 130 * space with the elevator data. 131 */ 132 union { 133 struct { 134 struct io_cq *icq; 135 void *priv[2]; 136 } elv; 137 138 struct { 139 unsigned int seq; 140 struct list_head list; 141 rq_end_io_fn *saved_end_io; 142 } flush; 143 }; 144 145 struct gendisk *rq_disk; 146 struct hd_struct *part; 147 unsigned long start_time; 148 #ifdef CONFIG_BLK_CGROUP 149 struct request_list *rl; /* rl this rq is alloced from */ 150 unsigned long long start_time_ns; 151 unsigned long long io_start_time_ns; /* when passed to hardware */ 152 #endif 153 /* Number of scatter-gather DMA addr+len pairs after 154 * physical address coalescing is performed. 155 */ 156 unsigned short nr_phys_segments; 157 #if defined(CONFIG_BLK_DEV_INTEGRITY) 158 unsigned short nr_integrity_segments; 159 #endif 160 161 unsigned short ioprio; 162 163 int ref_count; 164 165 void *special; /* opaque pointer available for LLD use */ 166 char *buffer; /* kaddr of the current segment if available */ 167 168 int tag; 169 int errors; 170 171 /* 172 * when request is used as a packet command carrier 173 */ 174 unsigned char __cmd[BLK_MAX_CDB]; 175 unsigned char *cmd; 176 unsigned short cmd_len; 177 178 unsigned int extra_len; /* length of alignment and padding */ 179 unsigned int sense_len; 180 unsigned int resid_len; /* residual count */ 181 void *sense; 182 183 unsigned long deadline; 184 struct list_head timeout_list; 185 unsigned int timeout; 186 int retries; 187 188 /* 189 * completion callback. 190 */ 191 rq_end_io_fn *end_io; 192 void *end_io_data; 193 194 /* for bidi */ 195 struct request *next_rq; 196 }; 197 198 static inline unsigned short req_get_ioprio(struct request *req) 199 { 200 return req->ioprio; 201 } 202 203 /* 204 * State information carried for REQ_TYPE_PM_SUSPEND and REQ_TYPE_PM_RESUME 205 * requests. Some step values could eventually be made generic. 206 */ 207 struct request_pm_state 208 { 209 /* PM state machine step value, currently driver specific */ 210 int pm_step; 211 /* requested PM state value (S1, S2, S3, S4, ...) */ 212 u32 pm_state; 213 void* data; /* for driver use */ 214 }; 215 216 #include <linux/elevator.h> 217 218 typedef void (request_fn_proc) (struct request_queue *q); 219 typedef void (make_request_fn) (struct request_queue *q, struct bio *bio); 220 typedef int (prep_rq_fn) (struct request_queue *, struct request *); 221 typedef void (unprep_rq_fn) (struct request_queue *, struct request *); 222 223 struct bio_vec; 224 struct bvec_merge_data { 225 struct block_device *bi_bdev; 226 sector_t bi_sector; 227 unsigned bi_size; 228 unsigned long bi_rw; 229 }; 230 typedef int (merge_bvec_fn) (struct request_queue *, struct bvec_merge_data *, 231 struct bio_vec *); 232 typedef void (softirq_done_fn)(struct request *); 233 typedef int (dma_drain_needed_fn)(struct request *); 234 typedef int (lld_busy_fn) (struct request_queue *q); 235 typedef int (bsg_job_fn) (struct bsg_job *); 236 237 enum blk_eh_timer_return { 238 BLK_EH_NOT_HANDLED, 239 BLK_EH_HANDLED, 240 BLK_EH_RESET_TIMER, 241 }; 242 243 typedef enum blk_eh_timer_return (rq_timed_out_fn)(struct request *); 244 245 enum blk_queue_state { 246 Queue_down, 247 Queue_up, 248 }; 249 250 struct blk_queue_tag { 251 struct request **tag_index; /* map of busy tags */ 252 unsigned long *tag_map; /* bit map of free/busy tags */ 253 int busy; /* current depth */ 254 int max_depth; /* what we will send to device */ 255 int real_max_depth; /* what the array can hold */ 256 atomic_t refcnt; /* map can be shared */ 257 }; 258 259 #define BLK_SCSI_MAX_CMDS (256) 260 #define BLK_SCSI_CMD_PER_LONG (BLK_SCSI_MAX_CMDS / (sizeof(long) * 8)) 261 262 struct queue_limits { 263 unsigned long bounce_pfn; 264 unsigned long seg_boundary_mask; 265 266 unsigned int max_hw_sectors; 267 unsigned int max_sectors; 268 unsigned int max_segment_size; 269 unsigned int physical_block_size; 270 unsigned int alignment_offset; 271 unsigned int io_min; 272 unsigned int io_opt; 273 unsigned int max_discard_sectors; 274 unsigned int max_write_same_sectors; 275 unsigned int discard_granularity; 276 unsigned int discard_alignment; 277 278 unsigned short logical_block_size; 279 unsigned short max_segments; 280 unsigned short max_integrity_segments; 281 282 unsigned char misaligned; 283 unsigned char discard_misaligned; 284 unsigned char cluster; 285 unsigned char discard_zeroes_data; 286 }; 287 288 struct request_queue { 289 /* 290 * Together with queue_head for cacheline sharing 291 */ 292 struct list_head queue_head; 293 struct request *last_merge; 294 struct elevator_queue *elevator; 295 int nr_rqs[2]; /* # allocated [a]sync rqs */ 296 int nr_rqs_elvpriv; /* # allocated rqs w/ elvpriv */ 297 298 /* 299 * If blkcg is not used, @q->root_rl serves all requests. If blkcg 300 * is used, root blkg allocates from @q->root_rl and all other 301 * blkgs from their own blkg->rl. Which one to use should be 302 * determined using bio_request_list(). 303 */ 304 struct request_list root_rl; 305 306 request_fn_proc *request_fn; 307 make_request_fn *make_request_fn; 308 prep_rq_fn *prep_rq_fn; 309 unprep_rq_fn *unprep_rq_fn; 310 merge_bvec_fn *merge_bvec_fn; 311 softirq_done_fn *softirq_done_fn; 312 rq_timed_out_fn *rq_timed_out_fn; 313 dma_drain_needed_fn *dma_drain_needed; 314 lld_busy_fn *lld_busy_fn; 315 316 /* 317 * Dispatch queue sorting 318 */ 319 sector_t end_sector; 320 struct request *boundary_rq; 321 322 /* 323 * Delayed queue handling 324 */ 325 struct delayed_work delay_work; 326 327 struct backing_dev_info backing_dev_info; 328 329 /* 330 * The queue owner gets to use this for whatever they like. 331 * ll_rw_blk doesn't touch it. 332 */ 333 void *queuedata; 334 335 /* 336 * various queue flags, see QUEUE_* below 337 */ 338 unsigned long queue_flags; 339 340 /* 341 * ida allocated id for this queue. Used to index queues from 342 * ioctx. 343 */ 344 int id; 345 346 /* 347 * queue needs bounce pages for pages above this limit 348 */ 349 gfp_t bounce_gfp; 350 351 /* 352 * protects queue structures from reentrancy. ->__queue_lock should 353 * _never_ be used directly, it is queue private. always use 354 * ->queue_lock. 355 */ 356 spinlock_t __queue_lock; 357 spinlock_t *queue_lock; 358 359 /* 360 * queue kobject 361 */ 362 struct kobject kobj; 363 364 #ifdef CONFIG_PM_RUNTIME 365 struct device *dev; 366 int rpm_status; 367 unsigned int nr_pending; 368 #endif 369 370 /* 371 * queue settings 372 */ 373 unsigned long nr_requests; /* Max # of requests */ 374 unsigned int nr_congestion_on; 375 unsigned int nr_congestion_off; 376 unsigned int nr_batching; 377 378 unsigned int dma_drain_size; 379 void *dma_drain_buffer; 380 unsigned int dma_pad_mask; 381 unsigned int dma_alignment; 382 383 struct blk_queue_tag *queue_tags; 384 struct list_head tag_busy_list; 385 386 unsigned int nr_sorted; 387 unsigned int in_flight[2]; 388 /* 389 * Number of active block driver functions for which blk_drain_queue() 390 * must wait. Must be incremented around functions that unlock the 391 * queue_lock internally, e.g. scsi_request_fn(). 392 */ 393 unsigned int request_fn_active; 394 395 unsigned int rq_timeout; 396 struct timer_list timeout; 397 struct list_head timeout_list; 398 399 struct list_head icq_list; 400 #ifdef CONFIG_BLK_CGROUP 401 DECLARE_BITMAP (blkcg_pols, BLKCG_MAX_POLS); 402 struct blkcg_gq *root_blkg; 403 struct list_head blkg_list; 404 #endif 405 406 struct queue_limits limits; 407 408 /* 409 * sg stuff 410 */ 411 unsigned int sg_timeout; 412 unsigned int sg_reserved_size; 413 int node; 414 #ifdef CONFIG_BLK_DEV_IO_TRACE 415 struct blk_trace *blk_trace; 416 #endif 417 /* 418 * for flush operations 419 */ 420 unsigned int flush_flags; 421 unsigned int flush_not_queueable:1; 422 unsigned int flush_queue_delayed:1; 423 unsigned int flush_pending_idx:1; 424 unsigned int flush_running_idx:1; 425 unsigned long flush_pending_since; 426 struct list_head flush_queue[2]; 427 struct list_head flush_data_in_flight; 428 struct request flush_rq; 429 430 struct mutex sysfs_lock; 431 432 int bypass_depth; 433 434 #if defined(CONFIG_BLK_DEV_BSG) 435 bsg_job_fn *bsg_job_fn; 436 int bsg_job_size; 437 struct bsg_class_device bsg_dev; 438 #endif 439 440 #ifdef CONFIG_BLK_CGROUP 441 struct list_head all_q_node; 442 #endif 443 #ifdef CONFIG_BLK_DEV_THROTTLING 444 /* Throttle data */ 445 struct throtl_data *td; 446 #endif 447 struct rcu_head rcu_head; 448 }; 449 450 #define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */ 451 #define QUEUE_FLAG_STOPPED 2 /* queue is stopped */ 452 #define QUEUE_FLAG_SYNCFULL 3 /* read queue has been filled */ 453 #define QUEUE_FLAG_ASYNCFULL 4 /* write queue has been filled */ 454 #define QUEUE_FLAG_DYING 5 /* queue being torn down */ 455 #define QUEUE_FLAG_BYPASS 6 /* act as dumb FIFO queue */ 456 #define QUEUE_FLAG_BIDI 7 /* queue supports bidi requests */ 457 #define QUEUE_FLAG_NOMERGES 8 /* disable merge attempts */ 458 #define QUEUE_FLAG_SAME_COMP 9 /* complete on same CPU-group */ 459 #define QUEUE_FLAG_FAIL_IO 10 /* fake timeout */ 460 #define QUEUE_FLAG_STACKABLE 11 /* supports request stacking */ 461 #define QUEUE_FLAG_NONROT 12 /* non-rotational device (SSD) */ 462 #define QUEUE_FLAG_VIRT QUEUE_FLAG_NONROT /* paravirt device */ 463 #define QUEUE_FLAG_IO_STAT 13 /* do IO stats */ 464 #define QUEUE_FLAG_DISCARD 14 /* supports DISCARD */ 465 #define QUEUE_FLAG_NOXMERGES 15 /* No extended merges */ 466 #define QUEUE_FLAG_ADD_RANDOM 16 /* Contributes to random pool */ 467 #define QUEUE_FLAG_SECDISCARD 17 /* supports SECDISCARD */ 468 #define QUEUE_FLAG_SAME_FORCE 18 /* force complete on same CPU */ 469 #define QUEUE_FLAG_DEAD 19 /* queue tear-down finished */ 470 471 #define QUEUE_FLAG_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \ 472 (1 << QUEUE_FLAG_STACKABLE) | \ 473 (1 << QUEUE_FLAG_SAME_COMP) | \ 474 (1 << QUEUE_FLAG_ADD_RANDOM)) 475 476 static inline void queue_lockdep_assert_held(struct request_queue *q) 477 { 478 if (q->queue_lock) 479 lockdep_assert_held(q->queue_lock); 480 } 481 482 static inline void queue_flag_set_unlocked(unsigned int flag, 483 struct request_queue *q) 484 { 485 __set_bit(flag, &q->queue_flags); 486 } 487 488 static inline int queue_flag_test_and_clear(unsigned int flag, 489 struct request_queue *q) 490 { 491 queue_lockdep_assert_held(q); 492 493 if (test_bit(flag, &q->queue_flags)) { 494 __clear_bit(flag, &q->queue_flags); 495 return 1; 496 } 497 498 return 0; 499 } 500 501 static inline int queue_flag_test_and_set(unsigned int flag, 502 struct request_queue *q) 503 { 504 queue_lockdep_assert_held(q); 505 506 if (!test_bit(flag, &q->queue_flags)) { 507 __set_bit(flag, &q->queue_flags); 508 return 0; 509 } 510 511 return 1; 512 } 513 514 static inline void queue_flag_set(unsigned int flag, struct request_queue *q) 515 { 516 queue_lockdep_assert_held(q); 517 __set_bit(flag, &q->queue_flags); 518 } 519 520 static inline void queue_flag_clear_unlocked(unsigned int flag, 521 struct request_queue *q) 522 { 523 __clear_bit(flag, &q->queue_flags); 524 } 525 526 static inline int queue_in_flight(struct request_queue *q) 527 { 528 return q->in_flight[0] + q->in_flight[1]; 529 } 530 531 static inline void queue_flag_clear(unsigned int flag, struct request_queue *q) 532 { 533 queue_lockdep_assert_held(q); 534 __clear_bit(flag, &q->queue_flags); 535 } 536 537 #define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags) 538 #define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags) 539 #define blk_queue_dying(q) test_bit(QUEUE_FLAG_DYING, &(q)->queue_flags) 540 #define blk_queue_dead(q) test_bit(QUEUE_FLAG_DEAD, &(q)->queue_flags) 541 #define blk_queue_bypass(q) test_bit(QUEUE_FLAG_BYPASS, &(q)->queue_flags) 542 #define blk_queue_nomerges(q) test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags) 543 #define blk_queue_noxmerges(q) \ 544 test_bit(QUEUE_FLAG_NOXMERGES, &(q)->queue_flags) 545 #define blk_queue_nonrot(q) test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags) 546 #define blk_queue_io_stat(q) test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags) 547 #define blk_queue_add_random(q) test_bit(QUEUE_FLAG_ADD_RANDOM, &(q)->queue_flags) 548 #define blk_queue_stackable(q) \ 549 test_bit(QUEUE_FLAG_STACKABLE, &(q)->queue_flags) 550 #define blk_queue_discard(q) test_bit(QUEUE_FLAG_DISCARD, &(q)->queue_flags) 551 #define blk_queue_secdiscard(q) (blk_queue_discard(q) && \ 552 test_bit(QUEUE_FLAG_SECDISCARD, &(q)->queue_flags)) 553 554 #define blk_noretry_request(rq) \ 555 ((rq)->cmd_flags & (REQ_FAILFAST_DEV|REQ_FAILFAST_TRANSPORT| \ 556 REQ_FAILFAST_DRIVER)) 557 558 #define blk_account_rq(rq) \ 559 (((rq)->cmd_flags & REQ_STARTED) && \ 560 ((rq)->cmd_type == REQ_TYPE_FS)) 561 562 #define blk_pm_request(rq) \ 563 ((rq)->cmd_type == REQ_TYPE_PM_SUSPEND || \ 564 (rq)->cmd_type == REQ_TYPE_PM_RESUME) 565 566 #define blk_rq_cpu_valid(rq) ((rq)->cpu != -1) 567 #define blk_bidi_rq(rq) ((rq)->next_rq != NULL) 568 /* rq->queuelist of dequeued request must be list_empty() */ 569 #define blk_queued_rq(rq) (!list_empty(&(rq)->queuelist)) 570 571 #define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist) 572 573 #define rq_data_dir(rq) ((rq)->cmd_flags & 1) 574 575 static inline unsigned int blk_queue_cluster(struct request_queue *q) 576 { 577 return q->limits.cluster; 578 } 579 580 /* 581 * We regard a request as sync, if either a read or a sync write 582 */ 583 static inline bool rw_is_sync(unsigned int rw_flags) 584 { 585 return !(rw_flags & REQ_WRITE) || (rw_flags & REQ_SYNC); 586 } 587 588 static inline bool rq_is_sync(struct request *rq) 589 { 590 return rw_is_sync(rq->cmd_flags); 591 } 592 593 static inline bool blk_rl_full(struct request_list *rl, bool sync) 594 { 595 unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL; 596 597 return rl->flags & flag; 598 } 599 600 static inline void blk_set_rl_full(struct request_list *rl, bool sync) 601 { 602 unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL; 603 604 rl->flags |= flag; 605 } 606 607 static inline void blk_clear_rl_full(struct request_list *rl, bool sync) 608 { 609 unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL; 610 611 rl->flags &= ~flag; 612 } 613 614 static inline bool rq_mergeable(struct request *rq) 615 { 616 if (rq->cmd_type != REQ_TYPE_FS) 617 return false; 618 619 if (rq->cmd_flags & REQ_NOMERGE_FLAGS) 620 return false; 621 622 return true; 623 } 624 625 static inline bool blk_check_merge_flags(unsigned int flags1, 626 unsigned int flags2) 627 { 628 if ((flags1 & REQ_DISCARD) != (flags2 & REQ_DISCARD)) 629 return false; 630 631 if ((flags1 & REQ_SECURE) != (flags2 & REQ_SECURE)) 632 return false; 633 634 if ((flags1 & REQ_WRITE_SAME) != (flags2 & REQ_WRITE_SAME)) 635 return false; 636 637 return true; 638 } 639 640 static inline bool blk_write_same_mergeable(struct bio *a, struct bio *b) 641 { 642 if (bio_data(a) == bio_data(b)) 643 return true; 644 645 return false; 646 } 647 648 /* 649 * q->prep_rq_fn return values 650 */ 651 #define BLKPREP_OK 0 /* serve it */ 652 #define BLKPREP_KILL 1 /* fatal error, kill */ 653 #define BLKPREP_DEFER 2 /* leave on queue */ 654 655 extern unsigned long blk_max_low_pfn, blk_max_pfn; 656 657 /* 658 * standard bounce addresses: 659 * 660 * BLK_BOUNCE_HIGH : bounce all highmem pages 661 * BLK_BOUNCE_ANY : don't bounce anything 662 * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary 663 */ 664 665 #if BITS_PER_LONG == 32 666 #define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT) 667 #else 668 #define BLK_BOUNCE_HIGH -1ULL 669 #endif 670 #define BLK_BOUNCE_ANY (-1ULL) 671 #define BLK_BOUNCE_ISA (DMA_BIT_MASK(24)) 672 673 /* 674 * default timeout for SG_IO if none specified 675 */ 676 #define BLK_DEFAULT_SG_TIMEOUT (60 * HZ) 677 #define BLK_MIN_SG_TIMEOUT (7 * HZ) 678 679 #ifdef CONFIG_BOUNCE 680 extern int init_emergency_isa_pool(void); 681 extern void blk_queue_bounce(struct request_queue *q, struct bio **bio); 682 #else 683 static inline int init_emergency_isa_pool(void) 684 { 685 return 0; 686 } 687 static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio) 688 { 689 } 690 #endif /* CONFIG_MMU */ 691 692 struct rq_map_data { 693 struct page **pages; 694 int page_order; 695 int nr_entries; 696 unsigned long offset; 697 int null_mapped; 698 int from_user; 699 }; 700 701 struct req_iterator { 702 int i; 703 struct bio *bio; 704 }; 705 706 /* This should not be used directly - use rq_for_each_segment */ 707 #define for_each_bio(_bio) \ 708 for (; _bio; _bio = _bio->bi_next) 709 #define __rq_for_each_bio(_bio, rq) \ 710 if ((rq->bio)) \ 711 for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next) 712 713 #define rq_for_each_segment(bvl, _rq, _iter) \ 714 __rq_for_each_bio(_iter.bio, _rq) \ 715 bio_for_each_segment(bvl, _iter.bio, _iter.i) 716 717 #define rq_iter_last(rq, _iter) \ 718 (_iter.bio->bi_next == NULL && _iter.i == _iter.bio->bi_vcnt-1) 719 720 #ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 721 # error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform" 722 #endif 723 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 724 extern void rq_flush_dcache_pages(struct request *rq); 725 #else 726 static inline void rq_flush_dcache_pages(struct request *rq) 727 { 728 } 729 #endif 730 731 extern int blk_register_queue(struct gendisk *disk); 732 extern void blk_unregister_queue(struct gendisk *disk); 733 extern void generic_make_request(struct bio *bio); 734 extern void blk_rq_init(struct request_queue *q, struct request *rq); 735 extern void blk_put_request(struct request *); 736 extern void __blk_put_request(struct request_queue *, struct request *); 737 extern struct request *blk_get_request(struct request_queue *, int, gfp_t); 738 extern struct request *blk_make_request(struct request_queue *, struct bio *, 739 gfp_t); 740 extern void blk_requeue_request(struct request_queue *, struct request *); 741 extern void blk_add_request_payload(struct request *rq, struct page *page, 742 unsigned int len); 743 extern int blk_rq_check_limits(struct request_queue *q, struct request *rq); 744 extern int blk_lld_busy(struct request_queue *q); 745 extern int blk_rq_prep_clone(struct request *rq, struct request *rq_src, 746 struct bio_set *bs, gfp_t gfp_mask, 747 int (*bio_ctr)(struct bio *, struct bio *, void *), 748 void *data); 749 extern void blk_rq_unprep_clone(struct request *rq); 750 extern int blk_insert_cloned_request(struct request_queue *q, 751 struct request *rq); 752 extern void blk_delay_queue(struct request_queue *, unsigned long); 753 extern void blk_recount_segments(struct request_queue *, struct bio *); 754 extern int scsi_verify_blk_ioctl(struct block_device *, unsigned int); 755 extern int scsi_cmd_blk_ioctl(struct block_device *, fmode_t, 756 unsigned int, void __user *); 757 extern int scsi_cmd_ioctl(struct request_queue *, struct gendisk *, fmode_t, 758 unsigned int, void __user *); 759 extern int sg_scsi_ioctl(struct request_queue *, struct gendisk *, fmode_t, 760 struct scsi_ioctl_command __user *); 761 762 extern void blk_queue_bio(struct request_queue *q, struct bio *bio); 763 764 /* 765 * A queue has just exitted congestion. Note this in the global counter of 766 * congested queues, and wake up anyone who was waiting for requests to be 767 * put back. 768 */ 769 static inline void blk_clear_queue_congested(struct request_queue *q, int sync) 770 { 771 clear_bdi_congested(&q->backing_dev_info, sync); 772 } 773 774 /* 775 * A queue has just entered congestion. Flag that in the queue's VM-visible 776 * state flags and increment the global gounter of congested queues. 777 */ 778 static inline void blk_set_queue_congested(struct request_queue *q, int sync) 779 { 780 set_bdi_congested(&q->backing_dev_info, sync); 781 } 782 783 extern void blk_start_queue(struct request_queue *q); 784 extern void blk_stop_queue(struct request_queue *q); 785 extern void blk_sync_queue(struct request_queue *q); 786 extern void __blk_stop_queue(struct request_queue *q); 787 extern void __blk_run_queue(struct request_queue *q); 788 extern void blk_run_queue(struct request_queue *); 789 extern void blk_run_queue_async(struct request_queue *q); 790 extern int blk_rq_map_user(struct request_queue *, struct request *, 791 struct rq_map_data *, void __user *, unsigned long, 792 gfp_t); 793 extern int blk_rq_unmap_user(struct bio *); 794 extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, unsigned int, gfp_t); 795 extern int blk_rq_map_user_iov(struct request_queue *, struct request *, 796 struct rq_map_data *, struct sg_iovec *, int, 797 unsigned int, gfp_t); 798 extern int blk_execute_rq(struct request_queue *, struct gendisk *, 799 struct request *, int); 800 extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *, 801 struct request *, int, rq_end_io_fn *); 802 803 static inline struct request_queue *bdev_get_queue(struct block_device *bdev) 804 { 805 return bdev->bd_disk->queue; 806 } 807 808 /* 809 * blk_rq_pos() : the current sector 810 * blk_rq_bytes() : bytes left in the entire request 811 * blk_rq_cur_bytes() : bytes left in the current segment 812 * blk_rq_err_bytes() : bytes left till the next error boundary 813 * blk_rq_sectors() : sectors left in the entire request 814 * blk_rq_cur_sectors() : sectors left in the current segment 815 */ 816 static inline sector_t blk_rq_pos(const struct request *rq) 817 { 818 return rq->__sector; 819 } 820 821 static inline unsigned int blk_rq_bytes(const struct request *rq) 822 { 823 return rq->__data_len; 824 } 825 826 static inline int blk_rq_cur_bytes(const struct request *rq) 827 { 828 return rq->bio ? bio_cur_bytes(rq->bio) : 0; 829 } 830 831 extern unsigned int blk_rq_err_bytes(const struct request *rq); 832 833 static inline unsigned int blk_rq_sectors(const struct request *rq) 834 { 835 return blk_rq_bytes(rq) >> 9; 836 } 837 838 static inline unsigned int blk_rq_cur_sectors(const struct request *rq) 839 { 840 return blk_rq_cur_bytes(rq) >> 9; 841 } 842 843 static inline unsigned int blk_queue_get_max_sectors(struct request_queue *q, 844 unsigned int cmd_flags) 845 { 846 if (unlikely(cmd_flags & REQ_DISCARD)) 847 return min(q->limits.max_discard_sectors, UINT_MAX >> 9); 848 849 if (unlikely(cmd_flags & REQ_WRITE_SAME)) 850 return q->limits.max_write_same_sectors; 851 852 return q->limits.max_sectors; 853 } 854 855 static inline unsigned int blk_rq_get_max_sectors(struct request *rq) 856 { 857 struct request_queue *q = rq->q; 858 859 if (unlikely(rq->cmd_type == REQ_TYPE_BLOCK_PC)) 860 return q->limits.max_hw_sectors; 861 862 return blk_queue_get_max_sectors(q, rq->cmd_flags); 863 } 864 865 static inline unsigned int blk_rq_count_bios(struct request *rq) 866 { 867 unsigned int nr_bios = 0; 868 struct bio *bio; 869 870 __rq_for_each_bio(bio, rq) 871 nr_bios++; 872 873 return nr_bios; 874 } 875 876 /* 877 * Request issue related functions. 878 */ 879 extern struct request *blk_peek_request(struct request_queue *q); 880 extern void blk_start_request(struct request *rq); 881 extern struct request *blk_fetch_request(struct request_queue *q); 882 883 /* 884 * Request completion related functions. 885 * 886 * blk_update_request() completes given number of bytes and updates 887 * the request without completing it. 888 * 889 * blk_end_request() and friends. __blk_end_request() must be called 890 * with the request queue spinlock acquired. 891 * 892 * Several drivers define their own end_request and call 893 * blk_end_request() for parts of the original function. 894 * This prevents code duplication in drivers. 895 */ 896 extern bool blk_update_request(struct request *rq, int error, 897 unsigned int nr_bytes); 898 extern bool blk_end_request(struct request *rq, int error, 899 unsigned int nr_bytes); 900 extern void blk_end_request_all(struct request *rq, int error); 901 extern bool blk_end_request_cur(struct request *rq, int error); 902 extern bool blk_end_request_err(struct request *rq, int error); 903 extern bool __blk_end_request(struct request *rq, int error, 904 unsigned int nr_bytes); 905 extern void __blk_end_request_all(struct request *rq, int error); 906 extern bool __blk_end_request_cur(struct request *rq, int error); 907 extern bool __blk_end_request_err(struct request *rq, int error); 908 909 extern void blk_complete_request(struct request *); 910 extern void __blk_complete_request(struct request *); 911 extern void blk_abort_request(struct request *); 912 extern void blk_unprep_request(struct request *); 913 914 /* 915 * Access functions for manipulating queue properties 916 */ 917 extern struct request_queue *blk_init_queue_node(request_fn_proc *rfn, 918 spinlock_t *lock, int node_id); 919 extern struct request_queue *blk_init_queue(request_fn_proc *, spinlock_t *); 920 extern struct request_queue *blk_init_allocated_queue(struct request_queue *, 921 request_fn_proc *, spinlock_t *); 922 extern void blk_cleanup_queue(struct request_queue *); 923 extern void blk_queue_make_request(struct request_queue *, make_request_fn *); 924 extern void blk_queue_bounce_limit(struct request_queue *, u64); 925 extern void blk_limits_max_hw_sectors(struct queue_limits *, unsigned int); 926 extern void blk_queue_max_hw_sectors(struct request_queue *, unsigned int); 927 extern void blk_queue_max_segments(struct request_queue *, unsigned short); 928 extern void blk_queue_max_segment_size(struct request_queue *, unsigned int); 929 extern void blk_queue_max_discard_sectors(struct request_queue *q, 930 unsigned int max_discard_sectors); 931 extern void blk_queue_max_write_same_sectors(struct request_queue *q, 932 unsigned int max_write_same_sectors); 933 extern void blk_queue_logical_block_size(struct request_queue *, unsigned short); 934 extern void blk_queue_physical_block_size(struct request_queue *, unsigned int); 935 extern void blk_queue_alignment_offset(struct request_queue *q, 936 unsigned int alignment); 937 extern void blk_limits_io_min(struct queue_limits *limits, unsigned int min); 938 extern void blk_queue_io_min(struct request_queue *q, unsigned int min); 939 extern void blk_limits_io_opt(struct queue_limits *limits, unsigned int opt); 940 extern void blk_queue_io_opt(struct request_queue *q, unsigned int opt); 941 extern void blk_set_default_limits(struct queue_limits *lim); 942 extern void blk_set_stacking_limits(struct queue_limits *lim); 943 extern int blk_stack_limits(struct queue_limits *t, struct queue_limits *b, 944 sector_t offset); 945 extern int bdev_stack_limits(struct queue_limits *t, struct block_device *bdev, 946 sector_t offset); 947 extern void disk_stack_limits(struct gendisk *disk, struct block_device *bdev, 948 sector_t offset); 949 extern void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b); 950 extern void blk_queue_dma_pad(struct request_queue *, unsigned int); 951 extern void blk_queue_update_dma_pad(struct request_queue *, unsigned int); 952 extern int blk_queue_dma_drain(struct request_queue *q, 953 dma_drain_needed_fn *dma_drain_needed, 954 void *buf, unsigned int size); 955 extern void blk_queue_lld_busy(struct request_queue *q, lld_busy_fn *fn); 956 extern void blk_queue_segment_boundary(struct request_queue *, unsigned long); 957 extern void blk_queue_prep_rq(struct request_queue *, prep_rq_fn *pfn); 958 extern void blk_queue_unprep_rq(struct request_queue *, unprep_rq_fn *ufn); 959 extern void blk_queue_merge_bvec(struct request_queue *, merge_bvec_fn *); 960 extern void blk_queue_dma_alignment(struct request_queue *, int); 961 extern void blk_queue_update_dma_alignment(struct request_queue *, int); 962 extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *); 963 extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *); 964 extern void blk_queue_rq_timeout(struct request_queue *, unsigned int); 965 extern void blk_queue_flush(struct request_queue *q, unsigned int flush); 966 extern void blk_queue_flush_queueable(struct request_queue *q, bool queueable); 967 extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev); 968 969 extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *); 970 extern int blk_bio_map_sg(struct request_queue *q, struct bio *bio, 971 struct scatterlist *sglist); 972 extern void blk_dump_rq_flags(struct request *, char *); 973 extern long nr_blockdev_pages(void); 974 975 bool __must_check blk_get_queue(struct request_queue *); 976 struct request_queue *blk_alloc_queue(gfp_t); 977 struct request_queue *blk_alloc_queue_node(gfp_t, int); 978 extern void blk_put_queue(struct request_queue *); 979 980 /* 981 * block layer runtime pm functions 982 */ 983 #ifdef CONFIG_PM_RUNTIME 984 extern void blk_pm_runtime_init(struct request_queue *q, struct device *dev); 985 extern int blk_pre_runtime_suspend(struct request_queue *q); 986 extern void blk_post_runtime_suspend(struct request_queue *q, int err); 987 extern void blk_pre_runtime_resume(struct request_queue *q); 988 extern void blk_post_runtime_resume(struct request_queue *q, int err); 989 #else 990 static inline void blk_pm_runtime_init(struct request_queue *q, 991 struct device *dev) {} 992 static inline int blk_pre_runtime_suspend(struct request_queue *q) 993 { 994 return -ENOSYS; 995 } 996 static inline void blk_post_runtime_suspend(struct request_queue *q, int err) {} 997 static inline void blk_pre_runtime_resume(struct request_queue *q) {} 998 static inline void blk_post_runtime_resume(struct request_queue *q, int err) {} 999 #endif 1000 1001 /* 1002 * blk_plug permits building a queue of related requests by holding the I/O 1003 * fragments for a short period. This allows merging of sequential requests 1004 * into single larger request. As the requests are moved from a per-task list to 1005 * the device's request_queue in a batch, this results in improved scalability 1006 * as the lock contention for request_queue lock is reduced. 1007 * 1008 * It is ok not to disable preemption when adding the request to the plug list 1009 * or when attempting a merge, because blk_schedule_flush_list() will only flush 1010 * the plug list when the task sleeps by itself. For details, please see 1011 * schedule() where blk_schedule_flush_plug() is called. 1012 */ 1013 struct blk_plug { 1014 unsigned long magic; /* detect uninitialized use-cases */ 1015 struct list_head list; /* requests */ 1016 struct list_head cb_list; /* md requires an unplug callback */ 1017 }; 1018 #define BLK_MAX_REQUEST_COUNT 16 1019 1020 struct blk_plug_cb; 1021 typedef void (*blk_plug_cb_fn)(struct blk_plug_cb *, bool); 1022 struct blk_plug_cb { 1023 struct list_head list; 1024 blk_plug_cb_fn callback; 1025 void *data; 1026 }; 1027 extern struct blk_plug_cb *blk_check_plugged(blk_plug_cb_fn unplug, 1028 void *data, int size); 1029 extern void blk_start_plug(struct blk_plug *); 1030 extern void blk_finish_plug(struct blk_plug *); 1031 extern void blk_flush_plug_list(struct blk_plug *, bool); 1032 1033 static inline void blk_flush_plug(struct task_struct *tsk) 1034 { 1035 struct blk_plug *plug = tsk->plug; 1036 1037 if (plug) 1038 blk_flush_plug_list(plug, false); 1039 } 1040 1041 static inline void blk_schedule_flush_plug(struct task_struct *tsk) 1042 { 1043 struct blk_plug *plug = tsk->plug; 1044 1045 if (plug) 1046 blk_flush_plug_list(plug, true); 1047 } 1048 1049 static inline bool blk_needs_flush_plug(struct task_struct *tsk) 1050 { 1051 struct blk_plug *plug = tsk->plug; 1052 1053 return plug && (!list_empty(&plug->list) || !list_empty(&plug->cb_list)); 1054 } 1055 1056 /* 1057 * tag stuff 1058 */ 1059 #define blk_rq_tagged(rq) ((rq)->cmd_flags & REQ_QUEUED) 1060 extern int blk_queue_start_tag(struct request_queue *, struct request *); 1061 extern struct request *blk_queue_find_tag(struct request_queue *, int); 1062 extern void blk_queue_end_tag(struct request_queue *, struct request *); 1063 extern int blk_queue_init_tags(struct request_queue *, int, struct blk_queue_tag *); 1064 extern void blk_queue_free_tags(struct request_queue *); 1065 extern int blk_queue_resize_tags(struct request_queue *, int); 1066 extern void blk_queue_invalidate_tags(struct request_queue *); 1067 extern struct blk_queue_tag *blk_init_tags(int); 1068 extern void blk_free_tags(struct blk_queue_tag *); 1069 1070 static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt, 1071 int tag) 1072 { 1073 if (unlikely(bqt == NULL || tag >= bqt->real_max_depth)) 1074 return NULL; 1075 return bqt->tag_index[tag]; 1076 } 1077 1078 #define BLKDEV_DISCARD_SECURE 0x01 /* secure discard */ 1079 1080 extern int blkdev_issue_flush(struct block_device *, gfp_t, sector_t *); 1081 extern int blkdev_issue_discard(struct block_device *bdev, sector_t sector, 1082 sector_t nr_sects, gfp_t gfp_mask, unsigned long flags); 1083 extern int blkdev_issue_write_same(struct block_device *bdev, sector_t sector, 1084 sector_t nr_sects, gfp_t gfp_mask, struct page *page); 1085 extern int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector, 1086 sector_t nr_sects, gfp_t gfp_mask); 1087 static inline int sb_issue_discard(struct super_block *sb, sector_t block, 1088 sector_t nr_blocks, gfp_t gfp_mask, unsigned long flags) 1089 { 1090 return blkdev_issue_discard(sb->s_bdev, block << (sb->s_blocksize_bits - 9), 1091 nr_blocks << (sb->s_blocksize_bits - 9), 1092 gfp_mask, flags); 1093 } 1094 static inline int sb_issue_zeroout(struct super_block *sb, sector_t block, 1095 sector_t nr_blocks, gfp_t gfp_mask) 1096 { 1097 return blkdev_issue_zeroout(sb->s_bdev, 1098 block << (sb->s_blocksize_bits - 9), 1099 nr_blocks << (sb->s_blocksize_bits - 9), 1100 gfp_mask); 1101 } 1102 1103 extern int blk_verify_command(unsigned char *cmd, fmode_t has_write_perm); 1104 1105 enum blk_default_limits { 1106 BLK_MAX_SEGMENTS = 128, 1107 BLK_SAFE_MAX_SECTORS = 255, 1108 BLK_DEF_MAX_SECTORS = 1024, 1109 BLK_MAX_SEGMENT_SIZE = 65536, 1110 BLK_SEG_BOUNDARY_MASK = 0xFFFFFFFFUL, 1111 }; 1112 1113 #define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist) 1114 1115 static inline unsigned long queue_bounce_pfn(struct request_queue *q) 1116 { 1117 return q->limits.bounce_pfn; 1118 } 1119 1120 static inline unsigned long queue_segment_boundary(struct request_queue *q) 1121 { 1122 return q->limits.seg_boundary_mask; 1123 } 1124 1125 static inline unsigned int queue_max_sectors(struct request_queue *q) 1126 { 1127 return q->limits.max_sectors; 1128 } 1129 1130 static inline unsigned int queue_max_hw_sectors(struct request_queue *q) 1131 { 1132 return q->limits.max_hw_sectors; 1133 } 1134 1135 static inline unsigned short queue_max_segments(struct request_queue *q) 1136 { 1137 return q->limits.max_segments; 1138 } 1139 1140 static inline unsigned int queue_max_segment_size(struct request_queue *q) 1141 { 1142 return q->limits.max_segment_size; 1143 } 1144 1145 static inline unsigned short queue_logical_block_size(struct request_queue *q) 1146 { 1147 int retval = 512; 1148 1149 if (q && q->limits.logical_block_size) 1150 retval = q->limits.logical_block_size; 1151 1152 return retval; 1153 } 1154 1155 static inline unsigned short bdev_logical_block_size(struct block_device *bdev) 1156 { 1157 return queue_logical_block_size(bdev_get_queue(bdev)); 1158 } 1159 1160 static inline unsigned int queue_physical_block_size(struct request_queue *q) 1161 { 1162 return q->limits.physical_block_size; 1163 } 1164 1165 static inline unsigned int bdev_physical_block_size(struct block_device *bdev) 1166 { 1167 return queue_physical_block_size(bdev_get_queue(bdev)); 1168 } 1169 1170 static inline unsigned int queue_io_min(struct request_queue *q) 1171 { 1172 return q->limits.io_min; 1173 } 1174 1175 static inline int bdev_io_min(struct block_device *bdev) 1176 { 1177 return queue_io_min(bdev_get_queue(bdev)); 1178 } 1179 1180 static inline unsigned int queue_io_opt(struct request_queue *q) 1181 { 1182 return q->limits.io_opt; 1183 } 1184 1185 static inline int bdev_io_opt(struct block_device *bdev) 1186 { 1187 return queue_io_opt(bdev_get_queue(bdev)); 1188 } 1189 1190 static inline int queue_alignment_offset(struct request_queue *q) 1191 { 1192 if (q->limits.misaligned) 1193 return -1; 1194 1195 return q->limits.alignment_offset; 1196 } 1197 1198 static inline int queue_limit_alignment_offset(struct queue_limits *lim, sector_t sector) 1199 { 1200 unsigned int granularity = max(lim->physical_block_size, lim->io_min); 1201 unsigned int alignment = (sector << 9) & (granularity - 1); 1202 1203 return (granularity + lim->alignment_offset - alignment) 1204 & (granularity - 1); 1205 } 1206 1207 static inline int bdev_alignment_offset(struct block_device *bdev) 1208 { 1209 struct request_queue *q = bdev_get_queue(bdev); 1210 1211 if (q->limits.misaligned) 1212 return -1; 1213 1214 if (bdev != bdev->bd_contains) 1215 return bdev->bd_part->alignment_offset; 1216 1217 return q->limits.alignment_offset; 1218 } 1219 1220 static inline int queue_discard_alignment(struct request_queue *q) 1221 { 1222 if (q->limits.discard_misaligned) 1223 return -1; 1224 1225 return q->limits.discard_alignment; 1226 } 1227 1228 static inline int queue_limit_discard_alignment(struct queue_limits *lim, sector_t sector) 1229 { 1230 unsigned int alignment, granularity, offset; 1231 1232 if (!lim->max_discard_sectors) 1233 return 0; 1234 1235 /* Why are these in bytes, not sectors? */ 1236 alignment = lim->discard_alignment >> 9; 1237 granularity = lim->discard_granularity >> 9; 1238 if (!granularity) 1239 return 0; 1240 1241 /* Offset of the partition start in 'granularity' sectors */ 1242 offset = sector_div(sector, granularity); 1243 1244 /* And why do we do this modulus *again* in blkdev_issue_discard()? */ 1245 offset = (granularity + alignment - offset) % granularity; 1246 1247 /* Turn it back into bytes, gaah */ 1248 return offset << 9; 1249 } 1250 1251 static inline int bdev_discard_alignment(struct block_device *bdev) 1252 { 1253 struct request_queue *q = bdev_get_queue(bdev); 1254 1255 if (bdev != bdev->bd_contains) 1256 return bdev->bd_part->discard_alignment; 1257 1258 return q->limits.discard_alignment; 1259 } 1260 1261 static inline unsigned int queue_discard_zeroes_data(struct request_queue *q) 1262 { 1263 if (q->limits.max_discard_sectors && q->limits.discard_zeroes_data == 1) 1264 return 1; 1265 1266 return 0; 1267 } 1268 1269 static inline unsigned int bdev_discard_zeroes_data(struct block_device *bdev) 1270 { 1271 return queue_discard_zeroes_data(bdev_get_queue(bdev)); 1272 } 1273 1274 static inline unsigned int bdev_write_same(struct block_device *bdev) 1275 { 1276 struct request_queue *q = bdev_get_queue(bdev); 1277 1278 if (q) 1279 return q->limits.max_write_same_sectors; 1280 1281 return 0; 1282 } 1283 1284 static inline int queue_dma_alignment(struct request_queue *q) 1285 { 1286 return q ? q->dma_alignment : 511; 1287 } 1288 1289 static inline int blk_rq_aligned(struct request_queue *q, unsigned long addr, 1290 unsigned int len) 1291 { 1292 unsigned int alignment = queue_dma_alignment(q) | q->dma_pad_mask; 1293 return !(addr & alignment) && !(len & alignment); 1294 } 1295 1296 /* assumes size > 256 */ 1297 static inline unsigned int blksize_bits(unsigned int size) 1298 { 1299 unsigned int bits = 8; 1300 do { 1301 bits++; 1302 size >>= 1; 1303 } while (size > 256); 1304 return bits; 1305 } 1306 1307 static inline unsigned int block_size(struct block_device *bdev) 1308 { 1309 return bdev->bd_block_size; 1310 } 1311 1312 static inline bool queue_flush_queueable(struct request_queue *q) 1313 { 1314 return !q->flush_not_queueable; 1315 } 1316 1317 typedef struct {struct page *v;} Sector; 1318 1319 unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *); 1320 1321 static inline void put_dev_sector(Sector p) 1322 { 1323 page_cache_release(p.v); 1324 } 1325 1326 struct work_struct; 1327 int kblockd_schedule_work(struct request_queue *q, struct work_struct *work); 1328 1329 #ifdef CONFIG_BLK_CGROUP 1330 /* 1331 * This should not be using sched_clock(). A real patch is in progress 1332 * to fix this up, until that is in place we need to disable preemption 1333 * around sched_clock() in this function and set_io_start_time_ns(). 1334 */ 1335 static inline void set_start_time_ns(struct request *req) 1336 { 1337 preempt_disable(); 1338 req->start_time_ns = sched_clock(); 1339 preempt_enable(); 1340 } 1341 1342 static inline void set_io_start_time_ns(struct request *req) 1343 { 1344 preempt_disable(); 1345 req->io_start_time_ns = sched_clock(); 1346 preempt_enable(); 1347 } 1348 1349 static inline uint64_t rq_start_time_ns(struct request *req) 1350 { 1351 return req->start_time_ns; 1352 } 1353 1354 static inline uint64_t rq_io_start_time_ns(struct request *req) 1355 { 1356 return req->io_start_time_ns; 1357 } 1358 #else 1359 static inline void set_start_time_ns(struct request *req) {} 1360 static inline void set_io_start_time_ns(struct request *req) {} 1361 static inline uint64_t rq_start_time_ns(struct request *req) 1362 { 1363 return 0; 1364 } 1365 static inline uint64_t rq_io_start_time_ns(struct request *req) 1366 { 1367 return 0; 1368 } 1369 #endif 1370 1371 #define MODULE_ALIAS_BLOCKDEV(major,minor) \ 1372 MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor)) 1373 #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \ 1374 MODULE_ALIAS("block-major-" __stringify(major) "-*") 1375 1376 #if defined(CONFIG_BLK_DEV_INTEGRITY) 1377 1378 #define INTEGRITY_FLAG_READ 2 /* verify data integrity on read */ 1379 #define INTEGRITY_FLAG_WRITE 4 /* generate data integrity on write */ 1380 1381 struct blk_integrity_exchg { 1382 void *prot_buf; 1383 void *data_buf; 1384 sector_t sector; 1385 unsigned int data_size; 1386 unsigned short sector_size; 1387 const char *disk_name; 1388 }; 1389 1390 typedef void (integrity_gen_fn) (struct blk_integrity_exchg *); 1391 typedef int (integrity_vrfy_fn) (struct blk_integrity_exchg *); 1392 typedef void (integrity_set_tag_fn) (void *, void *, unsigned int); 1393 typedef void (integrity_get_tag_fn) (void *, void *, unsigned int); 1394 1395 struct blk_integrity { 1396 integrity_gen_fn *generate_fn; 1397 integrity_vrfy_fn *verify_fn; 1398 integrity_set_tag_fn *set_tag_fn; 1399 integrity_get_tag_fn *get_tag_fn; 1400 1401 unsigned short flags; 1402 unsigned short tuple_size; 1403 unsigned short sector_size; 1404 unsigned short tag_size; 1405 1406 const char *name; 1407 1408 struct kobject kobj; 1409 }; 1410 1411 extern bool blk_integrity_is_initialized(struct gendisk *); 1412 extern int blk_integrity_register(struct gendisk *, struct blk_integrity *); 1413 extern void blk_integrity_unregister(struct gendisk *); 1414 extern int blk_integrity_compare(struct gendisk *, struct gendisk *); 1415 extern int blk_rq_map_integrity_sg(struct request_queue *, struct bio *, 1416 struct scatterlist *); 1417 extern int blk_rq_count_integrity_sg(struct request_queue *, struct bio *); 1418 extern int blk_integrity_merge_rq(struct request_queue *, struct request *, 1419 struct request *); 1420 extern int blk_integrity_merge_bio(struct request_queue *, struct request *, 1421 struct bio *); 1422 1423 static inline 1424 struct blk_integrity *bdev_get_integrity(struct block_device *bdev) 1425 { 1426 return bdev->bd_disk->integrity; 1427 } 1428 1429 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk) 1430 { 1431 return disk->integrity; 1432 } 1433 1434 static inline int blk_integrity_rq(struct request *rq) 1435 { 1436 if (rq->bio == NULL) 1437 return 0; 1438 1439 return bio_integrity(rq->bio); 1440 } 1441 1442 static inline void blk_queue_max_integrity_segments(struct request_queue *q, 1443 unsigned int segs) 1444 { 1445 q->limits.max_integrity_segments = segs; 1446 } 1447 1448 static inline unsigned short 1449 queue_max_integrity_segments(struct request_queue *q) 1450 { 1451 return q->limits.max_integrity_segments; 1452 } 1453 1454 #else /* CONFIG_BLK_DEV_INTEGRITY */ 1455 1456 struct bio; 1457 struct block_device; 1458 struct gendisk; 1459 struct blk_integrity; 1460 1461 static inline int blk_integrity_rq(struct request *rq) 1462 { 1463 return 0; 1464 } 1465 static inline int blk_rq_count_integrity_sg(struct request_queue *q, 1466 struct bio *b) 1467 { 1468 return 0; 1469 } 1470 static inline int blk_rq_map_integrity_sg(struct request_queue *q, 1471 struct bio *b, 1472 struct scatterlist *s) 1473 { 1474 return 0; 1475 } 1476 static inline struct blk_integrity *bdev_get_integrity(struct block_device *b) 1477 { 1478 return 0; 1479 } 1480 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk) 1481 { 1482 return NULL; 1483 } 1484 static inline int blk_integrity_compare(struct gendisk *a, struct gendisk *b) 1485 { 1486 return 0; 1487 } 1488 static inline int blk_integrity_register(struct gendisk *d, 1489 struct blk_integrity *b) 1490 { 1491 return 0; 1492 } 1493 static inline void blk_integrity_unregister(struct gendisk *d) 1494 { 1495 } 1496 static inline void blk_queue_max_integrity_segments(struct request_queue *q, 1497 unsigned int segs) 1498 { 1499 } 1500 static inline unsigned short queue_max_integrity_segments(struct request_queue *q) 1501 { 1502 return 0; 1503 } 1504 static inline int blk_integrity_merge_rq(struct request_queue *rq, 1505 struct request *r1, 1506 struct request *r2) 1507 { 1508 return 0; 1509 } 1510 static inline int blk_integrity_merge_bio(struct request_queue *rq, 1511 struct request *r, 1512 struct bio *b) 1513 { 1514 return 0; 1515 } 1516 static inline bool blk_integrity_is_initialized(struct gendisk *g) 1517 { 1518 return 0; 1519 } 1520 1521 #endif /* CONFIG_BLK_DEV_INTEGRITY */ 1522 1523 struct block_device_operations { 1524 int (*open) (struct block_device *, fmode_t); 1525 void (*release) (struct gendisk *, fmode_t); 1526 int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long); 1527 int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long); 1528 int (*direct_access) (struct block_device *, sector_t, 1529 void **, unsigned long *); 1530 unsigned int (*check_events) (struct gendisk *disk, 1531 unsigned int clearing); 1532 /* ->media_changed() is DEPRECATED, use ->check_events() instead */ 1533 int (*media_changed) (struct gendisk *); 1534 void (*unlock_native_capacity) (struct gendisk *); 1535 int (*revalidate_disk) (struct gendisk *); 1536 int (*getgeo)(struct block_device *, struct hd_geometry *); 1537 /* this callback is with swap_lock and sometimes page table lock held */ 1538 void (*swap_slot_free_notify) (struct block_device *, unsigned long); 1539 struct module *owner; 1540 }; 1541 1542 extern int __blkdev_driver_ioctl(struct block_device *, fmode_t, unsigned int, 1543 unsigned long); 1544 #else /* CONFIG_BLOCK */ 1545 /* 1546 * stubs for when the block layer is configured out 1547 */ 1548 #define buffer_heads_over_limit 0 1549 1550 static inline long nr_blockdev_pages(void) 1551 { 1552 return 0; 1553 } 1554 1555 struct blk_plug { 1556 }; 1557 1558 static inline void blk_start_plug(struct blk_plug *plug) 1559 { 1560 } 1561 1562 static inline void blk_finish_plug(struct blk_plug *plug) 1563 { 1564 } 1565 1566 static inline void blk_flush_plug(struct task_struct *task) 1567 { 1568 } 1569 1570 static inline void blk_schedule_flush_plug(struct task_struct *task) 1571 { 1572 } 1573 1574 1575 static inline bool blk_needs_flush_plug(struct task_struct *tsk) 1576 { 1577 return false; 1578 } 1579 1580 #endif /* CONFIG_BLOCK */ 1581 1582 #endif 1583