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 /* 365 * queue settings 366 */ 367 unsigned long nr_requests; /* Max # of requests */ 368 unsigned int nr_congestion_on; 369 unsigned int nr_congestion_off; 370 unsigned int nr_batching; 371 372 unsigned int dma_drain_size; 373 void *dma_drain_buffer; 374 unsigned int dma_pad_mask; 375 unsigned int dma_alignment; 376 377 struct blk_queue_tag *queue_tags; 378 struct list_head tag_busy_list; 379 380 unsigned int nr_sorted; 381 unsigned int in_flight[2]; 382 /* 383 * Number of active block driver functions for which blk_drain_queue() 384 * must wait. Must be incremented around functions that unlock the 385 * queue_lock internally, e.g. scsi_request_fn(). 386 */ 387 unsigned int request_fn_active; 388 389 unsigned int rq_timeout; 390 struct timer_list timeout; 391 struct list_head timeout_list; 392 393 struct list_head icq_list; 394 #ifdef CONFIG_BLK_CGROUP 395 DECLARE_BITMAP (blkcg_pols, BLKCG_MAX_POLS); 396 struct blkcg_gq *root_blkg; 397 struct list_head blkg_list; 398 #endif 399 400 struct queue_limits limits; 401 402 /* 403 * sg stuff 404 */ 405 unsigned int sg_timeout; 406 unsigned int sg_reserved_size; 407 int node; 408 #ifdef CONFIG_BLK_DEV_IO_TRACE 409 struct blk_trace *blk_trace; 410 #endif 411 /* 412 * for flush operations 413 */ 414 unsigned int flush_flags; 415 unsigned int flush_not_queueable:1; 416 unsigned int flush_queue_delayed:1; 417 unsigned int flush_pending_idx:1; 418 unsigned int flush_running_idx:1; 419 unsigned long flush_pending_since; 420 struct list_head flush_queue[2]; 421 struct list_head flush_data_in_flight; 422 struct request flush_rq; 423 424 struct mutex sysfs_lock; 425 426 int bypass_depth; 427 428 #if defined(CONFIG_BLK_DEV_BSG) 429 bsg_job_fn *bsg_job_fn; 430 int bsg_job_size; 431 struct bsg_class_device bsg_dev; 432 #endif 433 434 #ifdef CONFIG_BLK_CGROUP 435 struct list_head all_q_node; 436 #endif 437 #ifdef CONFIG_BLK_DEV_THROTTLING 438 /* Throttle data */ 439 struct throtl_data *td; 440 #endif 441 struct rcu_head rcu_head; 442 }; 443 444 #define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */ 445 #define QUEUE_FLAG_STOPPED 2 /* queue is stopped */ 446 #define QUEUE_FLAG_SYNCFULL 3 /* read queue has been filled */ 447 #define QUEUE_FLAG_ASYNCFULL 4 /* write queue has been filled */ 448 #define QUEUE_FLAG_DYING 5 /* queue being torn down */ 449 #define QUEUE_FLAG_BYPASS 6 /* act as dumb FIFO queue */ 450 #define QUEUE_FLAG_BIDI 7 /* queue supports bidi requests */ 451 #define QUEUE_FLAG_NOMERGES 8 /* disable merge attempts */ 452 #define QUEUE_FLAG_SAME_COMP 9 /* complete on same CPU-group */ 453 #define QUEUE_FLAG_FAIL_IO 10 /* fake timeout */ 454 #define QUEUE_FLAG_STACKABLE 11 /* supports request stacking */ 455 #define QUEUE_FLAG_NONROT 12 /* non-rotational device (SSD) */ 456 #define QUEUE_FLAG_VIRT QUEUE_FLAG_NONROT /* paravirt device */ 457 #define QUEUE_FLAG_IO_STAT 13 /* do IO stats */ 458 #define QUEUE_FLAG_DISCARD 14 /* supports DISCARD */ 459 #define QUEUE_FLAG_NOXMERGES 15 /* No extended merges */ 460 #define QUEUE_FLAG_ADD_RANDOM 16 /* Contributes to random pool */ 461 #define QUEUE_FLAG_SECDISCARD 17 /* supports SECDISCARD */ 462 #define QUEUE_FLAG_SAME_FORCE 18 /* force complete on same CPU */ 463 #define QUEUE_FLAG_DEAD 19 /* queue tear-down finished */ 464 465 #define QUEUE_FLAG_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \ 466 (1 << QUEUE_FLAG_STACKABLE) | \ 467 (1 << QUEUE_FLAG_SAME_COMP) | \ 468 (1 << QUEUE_FLAG_ADD_RANDOM)) 469 470 static inline void queue_lockdep_assert_held(struct request_queue *q) 471 { 472 if (q->queue_lock) 473 lockdep_assert_held(q->queue_lock); 474 } 475 476 static inline void queue_flag_set_unlocked(unsigned int flag, 477 struct request_queue *q) 478 { 479 __set_bit(flag, &q->queue_flags); 480 } 481 482 static inline int queue_flag_test_and_clear(unsigned int flag, 483 struct request_queue *q) 484 { 485 queue_lockdep_assert_held(q); 486 487 if (test_bit(flag, &q->queue_flags)) { 488 __clear_bit(flag, &q->queue_flags); 489 return 1; 490 } 491 492 return 0; 493 } 494 495 static inline int queue_flag_test_and_set(unsigned int flag, 496 struct request_queue *q) 497 { 498 queue_lockdep_assert_held(q); 499 500 if (!test_bit(flag, &q->queue_flags)) { 501 __set_bit(flag, &q->queue_flags); 502 return 0; 503 } 504 505 return 1; 506 } 507 508 static inline void queue_flag_set(unsigned int flag, struct request_queue *q) 509 { 510 queue_lockdep_assert_held(q); 511 __set_bit(flag, &q->queue_flags); 512 } 513 514 static inline void queue_flag_clear_unlocked(unsigned int flag, 515 struct request_queue *q) 516 { 517 __clear_bit(flag, &q->queue_flags); 518 } 519 520 static inline int queue_in_flight(struct request_queue *q) 521 { 522 return q->in_flight[0] + q->in_flight[1]; 523 } 524 525 static inline void queue_flag_clear(unsigned int flag, struct request_queue *q) 526 { 527 queue_lockdep_assert_held(q); 528 __clear_bit(flag, &q->queue_flags); 529 } 530 531 #define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags) 532 #define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags) 533 #define blk_queue_dying(q) test_bit(QUEUE_FLAG_DYING, &(q)->queue_flags) 534 #define blk_queue_dead(q) test_bit(QUEUE_FLAG_DEAD, &(q)->queue_flags) 535 #define blk_queue_bypass(q) test_bit(QUEUE_FLAG_BYPASS, &(q)->queue_flags) 536 #define blk_queue_nomerges(q) test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags) 537 #define blk_queue_noxmerges(q) \ 538 test_bit(QUEUE_FLAG_NOXMERGES, &(q)->queue_flags) 539 #define blk_queue_nonrot(q) test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags) 540 #define blk_queue_io_stat(q) test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags) 541 #define blk_queue_add_random(q) test_bit(QUEUE_FLAG_ADD_RANDOM, &(q)->queue_flags) 542 #define blk_queue_stackable(q) \ 543 test_bit(QUEUE_FLAG_STACKABLE, &(q)->queue_flags) 544 #define blk_queue_discard(q) test_bit(QUEUE_FLAG_DISCARD, &(q)->queue_flags) 545 #define blk_queue_secdiscard(q) (blk_queue_discard(q) && \ 546 test_bit(QUEUE_FLAG_SECDISCARD, &(q)->queue_flags)) 547 548 #define blk_noretry_request(rq) \ 549 ((rq)->cmd_flags & (REQ_FAILFAST_DEV|REQ_FAILFAST_TRANSPORT| \ 550 REQ_FAILFAST_DRIVER)) 551 552 #define blk_account_rq(rq) \ 553 (((rq)->cmd_flags & REQ_STARTED) && \ 554 ((rq)->cmd_type == REQ_TYPE_FS)) 555 556 #define blk_pm_request(rq) \ 557 ((rq)->cmd_type == REQ_TYPE_PM_SUSPEND || \ 558 (rq)->cmd_type == REQ_TYPE_PM_RESUME) 559 560 #define blk_rq_cpu_valid(rq) ((rq)->cpu != -1) 561 #define blk_bidi_rq(rq) ((rq)->next_rq != NULL) 562 /* rq->queuelist of dequeued request must be list_empty() */ 563 #define blk_queued_rq(rq) (!list_empty(&(rq)->queuelist)) 564 565 #define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist) 566 567 #define rq_data_dir(rq) ((rq)->cmd_flags & 1) 568 569 static inline unsigned int blk_queue_cluster(struct request_queue *q) 570 { 571 return q->limits.cluster; 572 } 573 574 /* 575 * We regard a request as sync, if either a read or a sync write 576 */ 577 static inline bool rw_is_sync(unsigned int rw_flags) 578 { 579 return !(rw_flags & REQ_WRITE) || (rw_flags & REQ_SYNC); 580 } 581 582 static inline bool rq_is_sync(struct request *rq) 583 { 584 return rw_is_sync(rq->cmd_flags); 585 } 586 587 static inline bool blk_rl_full(struct request_list *rl, bool sync) 588 { 589 unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL; 590 591 return rl->flags & flag; 592 } 593 594 static inline void blk_set_rl_full(struct request_list *rl, bool sync) 595 { 596 unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL; 597 598 rl->flags |= flag; 599 } 600 601 static inline void blk_clear_rl_full(struct request_list *rl, bool sync) 602 { 603 unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL; 604 605 rl->flags &= ~flag; 606 } 607 608 static inline bool rq_mergeable(struct request *rq) 609 { 610 if (rq->cmd_type != REQ_TYPE_FS) 611 return false; 612 613 if (rq->cmd_flags & REQ_NOMERGE_FLAGS) 614 return false; 615 616 return true; 617 } 618 619 static inline bool blk_check_merge_flags(unsigned int flags1, 620 unsigned int flags2) 621 { 622 if ((flags1 & REQ_DISCARD) != (flags2 & REQ_DISCARD)) 623 return false; 624 625 if ((flags1 & REQ_SECURE) != (flags2 & REQ_SECURE)) 626 return false; 627 628 if ((flags1 & REQ_WRITE_SAME) != (flags2 & REQ_WRITE_SAME)) 629 return false; 630 631 return true; 632 } 633 634 static inline bool blk_write_same_mergeable(struct bio *a, struct bio *b) 635 { 636 if (bio_data(a) == bio_data(b)) 637 return true; 638 639 return false; 640 } 641 642 /* 643 * q->prep_rq_fn return values 644 */ 645 #define BLKPREP_OK 0 /* serve it */ 646 #define BLKPREP_KILL 1 /* fatal error, kill */ 647 #define BLKPREP_DEFER 2 /* leave on queue */ 648 649 extern unsigned long blk_max_low_pfn, blk_max_pfn; 650 651 /* 652 * standard bounce addresses: 653 * 654 * BLK_BOUNCE_HIGH : bounce all highmem pages 655 * BLK_BOUNCE_ANY : don't bounce anything 656 * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary 657 */ 658 659 #if BITS_PER_LONG == 32 660 #define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT) 661 #else 662 #define BLK_BOUNCE_HIGH -1ULL 663 #endif 664 #define BLK_BOUNCE_ANY (-1ULL) 665 #define BLK_BOUNCE_ISA (DMA_BIT_MASK(24)) 666 667 /* 668 * default timeout for SG_IO if none specified 669 */ 670 #define BLK_DEFAULT_SG_TIMEOUT (60 * HZ) 671 #define BLK_MIN_SG_TIMEOUT (7 * HZ) 672 673 #ifdef CONFIG_BOUNCE 674 extern int init_emergency_isa_pool(void); 675 extern void blk_queue_bounce(struct request_queue *q, struct bio **bio); 676 #else 677 static inline int init_emergency_isa_pool(void) 678 { 679 return 0; 680 } 681 static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio) 682 { 683 } 684 #endif /* CONFIG_MMU */ 685 686 struct rq_map_data { 687 struct page **pages; 688 int page_order; 689 int nr_entries; 690 unsigned long offset; 691 int null_mapped; 692 int from_user; 693 }; 694 695 struct req_iterator { 696 int i; 697 struct bio *bio; 698 }; 699 700 /* This should not be used directly - use rq_for_each_segment */ 701 #define for_each_bio(_bio) \ 702 for (; _bio; _bio = _bio->bi_next) 703 #define __rq_for_each_bio(_bio, rq) \ 704 if ((rq->bio)) \ 705 for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next) 706 707 #define rq_for_each_segment(bvl, _rq, _iter) \ 708 __rq_for_each_bio(_iter.bio, _rq) \ 709 bio_for_each_segment(bvl, _iter.bio, _iter.i) 710 711 #define rq_iter_last(rq, _iter) \ 712 (_iter.bio->bi_next == NULL && _iter.i == _iter.bio->bi_vcnt-1) 713 714 #ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 715 # error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform" 716 #endif 717 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 718 extern void rq_flush_dcache_pages(struct request *rq); 719 #else 720 static inline void rq_flush_dcache_pages(struct request *rq) 721 { 722 } 723 #endif 724 725 extern int blk_register_queue(struct gendisk *disk); 726 extern void blk_unregister_queue(struct gendisk *disk); 727 extern void generic_make_request(struct bio *bio); 728 extern void blk_rq_init(struct request_queue *q, struct request *rq); 729 extern void blk_put_request(struct request *); 730 extern void __blk_put_request(struct request_queue *, struct request *); 731 extern struct request *blk_get_request(struct request_queue *, int, gfp_t); 732 extern struct request *blk_make_request(struct request_queue *, struct bio *, 733 gfp_t); 734 extern void blk_requeue_request(struct request_queue *, struct request *); 735 extern void blk_add_request_payload(struct request *rq, struct page *page, 736 unsigned int len); 737 extern int blk_rq_check_limits(struct request_queue *q, struct request *rq); 738 extern int blk_lld_busy(struct request_queue *q); 739 extern int blk_rq_prep_clone(struct request *rq, struct request *rq_src, 740 struct bio_set *bs, gfp_t gfp_mask, 741 int (*bio_ctr)(struct bio *, struct bio *, void *), 742 void *data); 743 extern void blk_rq_unprep_clone(struct request *rq); 744 extern int blk_insert_cloned_request(struct request_queue *q, 745 struct request *rq); 746 extern void blk_delay_queue(struct request_queue *, unsigned long); 747 extern void blk_recount_segments(struct request_queue *, struct bio *); 748 extern int scsi_verify_blk_ioctl(struct block_device *, unsigned int); 749 extern int scsi_cmd_blk_ioctl(struct block_device *, fmode_t, 750 unsigned int, void __user *); 751 extern int scsi_cmd_ioctl(struct request_queue *, struct gendisk *, fmode_t, 752 unsigned int, void __user *); 753 extern int sg_scsi_ioctl(struct request_queue *, struct gendisk *, fmode_t, 754 struct scsi_ioctl_command __user *); 755 756 extern void blk_queue_bio(struct request_queue *q, struct bio *bio); 757 758 /* 759 * A queue has just exitted congestion. Note this in the global counter of 760 * congested queues, and wake up anyone who was waiting for requests to be 761 * put back. 762 */ 763 static inline void blk_clear_queue_congested(struct request_queue *q, int sync) 764 { 765 clear_bdi_congested(&q->backing_dev_info, sync); 766 } 767 768 /* 769 * A queue has just entered congestion. Flag that in the queue's VM-visible 770 * state flags and increment the global gounter of congested queues. 771 */ 772 static inline void blk_set_queue_congested(struct request_queue *q, int sync) 773 { 774 set_bdi_congested(&q->backing_dev_info, sync); 775 } 776 777 extern void blk_start_queue(struct request_queue *q); 778 extern void blk_stop_queue(struct request_queue *q); 779 extern void blk_sync_queue(struct request_queue *q); 780 extern void __blk_stop_queue(struct request_queue *q); 781 extern void __blk_run_queue(struct request_queue *q); 782 extern void blk_run_queue(struct request_queue *); 783 extern void blk_run_queue_async(struct request_queue *q); 784 extern int blk_rq_map_user(struct request_queue *, struct request *, 785 struct rq_map_data *, void __user *, unsigned long, 786 gfp_t); 787 extern int blk_rq_unmap_user(struct bio *); 788 extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, unsigned int, gfp_t); 789 extern int blk_rq_map_user_iov(struct request_queue *, struct request *, 790 struct rq_map_data *, struct sg_iovec *, int, 791 unsigned int, gfp_t); 792 extern int blk_execute_rq(struct request_queue *, struct gendisk *, 793 struct request *, int); 794 extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *, 795 struct request *, int, rq_end_io_fn *); 796 797 static inline struct request_queue *bdev_get_queue(struct block_device *bdev) 798 { 799 return bdev->bd_disk->queue; 800 } 801 802 /* 803 * blk_rq_pos() : the current sector 804 * blk_rq_bytes() : bytes left in the entire request 805 * blk_rq_cur_bytes() : bytes left in the current segment 806 * blk_rq_err_bytes() : bytes left till the next error boundary 807 * blk_rq_sectors() : sectors left in the entire request 808 * blk_rq_cur_sectors() : sectors left in the current segment 809 */ 810 static inline sector_t blk_rq_pos(const struct request *rq) 811 { 812 return rq->__sector; 813 } 814 815 static inline unsigned int blk_rq_bytes(const struct request *rq) 816 { 817 return rq->__data_len; 818 } 819 820 static inline int blk_rq_cur_bytes(const struct request *rq) 821 { 822 return rq->bio ? bio_cur_bytes(rq->bio) : 0; 823 } 824 825 extern unsigned int blk_rq_err_bytes(const struct request *rq); 826 827 static inline unsigned int blk_rq_sectors(const struct request *rq) 828 { 829 return blk_rq_bytes(rq) >> 9; 830 } 831 832 static inline unsigned int blk_rq_cur_sectors(const struct request *rq) 833 { 834 return blk_rq_cur_bytes(rq) >> 9; 835 } 836 837 static inline unsigned int blk_queue_get_max_sectors(struct request_queue *q, 838 unsigned int cmd_flags) 839 { 840 if (unlikely(cmd_flags & REQ_DISCARD)) 841 return q->limits.max_discard_sectors; 842 843 if (unlikely(cmd_flags & REQ_WRITE_SAME)) 844 return q->limits.max_write_same_sectors; 845 846 return q->limits.max_sectors; 847 } 848 849 static inline unsigned int blk_rq_get_max_sectors(struct request *rq) 850 { 851 struct request_queue *q = rq->q; 852 853 if (unlikely(rq->cmd_type == REQ_TYPE_BLOCK_PC)) 854 return q->limits.max_hw_sectors; 855 856 return blk_queue_get_max_sectors(q, rq->cmd_flags); 857 } 858 859 /* 860 * Request issue related functions. 861 */ 862 extern struct request *blk_peek_request(struct request_queue *q); 863 extern void blk_start_request(struct request *rq); 864 extern struct request *blk_fetch_request(struct request_queue *q); 865 866 /* 867 * Request completion related functions. 868 * 869 * blk_update_request() completes given number of bytes and updates 870 * the request without completing it. 871 * 872 * blk_end_request() and friends. __blk_end_request() must be called 873 * with the request queue spinlock acquired. 874 * 875 * Several drivers define their own end_request and call 876 * blk_end_request() for parts of the original function. 877 * This prevents code duplication in drivers. 878 */ 879 extern bool blk_update_request(struct request *rq, int error, 880 unsigned int nr_bytes); 881 extern bool blk_end_request(struct request *rq, int error, 882 unsigned int nr_bytes); 883 extern void blk_end_request_all(struct request *rq, int error); 884 extern bool blk_end_request_cur(struct request *rq, int error); 885 extern bool blk_end_request_err(struct request *rq, int error); 886 extern bool __blk_end_request(struct request *rq, int error, 887 unsigned int nr_bytes); 888 extern void __blk_end_request_all(struct request *rq, int error); 889 extern bool __blk_end_request_cur(struct request *rq, int error); 890 extern bool __blk_end_request_err(struct request *rq, int error); 891 892 extern void blk_complete_request(struct request *); 893 extern void __blk_complete_request(struct request *); 894 extern void blk_abort_request(struct request *); 895 extern void blk_unprep_request(struct request *); 896 897 /* 898 * Access functions for manipulating queue properties 899 */ 900 extern struct request_queue *blk_init_queue_node(request_fn_proc *rfn, 901 spinlock_t *lock, int node_id); 902 extern struct request_queue *blk_init_queue(request_fn_proc *, spinlock_t *); 903 extern struct request_queue *blk_init_allocated_queue(struct request_queue *, 904 request_fn_proc *, spinlock_t *); 905 extern void blk_cleanup_queue(struct request_queue *); 906 extern void blk_queue_make_request(struct request_queue *, make_request_fn *); 907 extern void blk_queue_bounce_limit(struct request_queue *, u64); 908 extern void blk_limits_max_hw_sectors(struct queue_limits *, unsigned int); 909 extern void blk_queue_max_hw_sectors(struct request_queue *, unsigned int); 910 extern void blk_queue_max_segments(struct request_queue *, unsigned short); 911 extern void blk_queue_max_segment_size(struct request_queue *, unsigned int); 912 extern void blk_queue_max_discard_sectors(struct request_queue *q, 913 unsigned int max_discard_sectors); 914 extern void blk_queue_max_write_same_sectors(struct request_queue *q, 915 unsigned int max_write_same_sectors); 916 extern void blk_queue_logical_block_size(struct request_queue *, unsigned short); 917 extern void blk_queue_physical_block_size(struct request_queue *, unsigned int); 918 extern void blk_queue_alignment_offset(struct request_queue *q, 919 unsigned int alignment); 920 extern void blk_limits_io_min(struct queue_limits *limits, unsigned int min); 921 extern void blk_queue_io_min(struct request_queue *q, unsigned int min); 922 extern void blk_limits_io_opt(struct queue_limits *limits, unsigned int opt); 923 extern void blk_queue_io_opt(struct request_queue *q, unsigned int opt); 924 extern void blk_set_default_limits(struct queue_limits *lim); 925 extern void blk_set_stacking_limits(struct queue_limits *lim); 926 extern int blk_stack_limits(struct queue_limits *t, struct queue_limits *b, 927 sector_t offset); 928 extern int bdev_stack_limits(struct queue_limits *t, struct block_device *bdev, 929 sector_t offset); 930 extern void disk_stack_limits(struct gendisk *disk, struct block_device *bdev, 931 sector_t offset); 932 extern void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b); 933 extern void blk_queue_dma_pad(struct request_queue *, unsigned int); 934 extern void blk_queue_update_dma_pad(struct request_queue *, unsigned int); 935 extern int blk_queue_dma_drain(struct request_queue *q, 936 dma_drain_needed_fn *dma_drain_needed, 937 void *buf, unsigned int size); 938 extern void blk_queue_lld_busy(struct request_queue *q, lld_busy_fn *fn); 939 extern void blk_queue_segment_boundary(struct request_queue *, unsigned long); 940 extern void blk_queue_prep_rq(struct request_queue *, prep_rq_fn *pfn); 941 extern void blk_queue_unprep_rq(struct request_queue *, unprep_rq_fn *ufn); 942 extern void blk_queue_merge_bvec(struct request_queue *, merge_bvec_fn *); 943 extern void blk_queue_dma_alignment(struct request_queue *, int); 944 extern void blk_queue_update_dma_alignment(struct request_queue *, int); 945 extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *); 946 extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *); 947 extern void blk_queue_rq_timeout(struct request_queue *, unsigned int); 948 extern void blk_queue_flush(struct request_queue *q, unsigned int flush); 949 extern void blk_queue_flush_queueable(struct request_queue *q, bool queueable); 950 extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev); 951 952 extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *); 953 extern int blk_bio_map_sg(struct request_queue *q, struct bio *bio, 954 struct scatterlist *sglist); 955 extern void blk_dump_rq_flags(struct request *, char *); 956 extern long nr_blockdev_pages(void); 957 958 bool __must_check blk_get_queue(struct request_queue *); 959 struct request_queue *blk_alloc_queue(gfp_t); 960 struct request_queue *blk_alloc_queue_node(gfp_t, int); 961 extern void blk_put_queue(struct request_queue *); 962 963 /* 964 * blk_plug permits building a queue of related requests by holding the I/O 965 * fragments for a short period. This allows merging of sequential requests 966 * into single larger request. As the requests are moved from a per-task list to 967 * the device's request_queue in a batch, this results in improved scalability 968 * as the lock contention for request_queue lock is reduced. 969 * 970 * It is ok not to disable preemption when adding the request to the plug list 971 * or when attempting a merge, because blk_schedule_flush_list() will only flush 972 * the plug list when the task sleeps by itself. For details, please see 973 * schedule() where blk_schedule_flush_plug() is called. 974 */ 975 struct blk_plug { 976 unsigned long magic; /* detect uninitialized use-cases */ 977 struct list_head list; /* requests */ 978 struct list_head cb_list; /* md requires an unplug callback */ 979 }; 980 #define BLK_MAX_REQUEST_COUNT 16 981 982 struct blk_plug_cb; 983 typedef void (*blk_plug_cb_fn)(struct blk_plug_cb *, bool); 984 struct blk_plug_cb { 985 struct list_head list; 986 blk_plug_cb_fn callback; 987 void *data; 988 }; 989 extern struct blk_plug_cb *blk_check_plugged(blk_plug_cb_fn unplug, 990 void *data, int size); 991 extern void blk_start_plug(struct blk_plug *); 992 extern void blk_finish_plug(struct blk_plug *); 993 extern void blk_flush_plug_list(struct blk_plug *, bool); 994 995 static inline void blk_flush_plug(struct task_struct *tsk) 996 { 997 struct blk_plug *plug = tsk->plug; 998 999 if (plug) 1000 blk_flush_plug_list(plug, false); 1001 } 1002 1003 static inline void blk_schedule_flush_plug(struct task_struct *tsk) 1004 { 1005 struct blk_plug *plug = tsk->plug; 1006 1007 if (plug) 1008 blk_flush_plug_list(plug, true); 1009 } 1010 1011 static inline bool blk_needs_flush_plug(struct task_struct *tsk) 1012 { 1013 struct blk_plug *plug = tsk->plug; 1014 1015 return plug && (!list_empty(&plug->list) || !list_empty(&plug->cb_list)); 1016 } 1017 1018 /* 1019 * tag stuff 1020 */ 1021 #define blk_rq_tagged(rq) ((rq)->cmd_flags & REQ_QUEUED) 1022 extern int blk_queue_start_tag(struct request_queue *, struct request *); 1023 extern struct request *blk_queue_find_tag(struct request_queue *, int); 1024 extern void blk_queue_end_tag(struct request_queue *, struct request *); 1025 extern int blk_queue_init_tags(struct request_queue *, int, struct blk_queue_tag *); 1026 extern void blk_queue_free_tags(struct request_queue *); 1027 extern int blk_queue_resize_tags(struct request_queue *, int); 1028 extern void blk_queue_invalidate_tags(struct request_queue *); 1029 extern struct blk_queue_tag *blk_init_tags(int); 1030 extern void blk_free_tags(struct blk_queue_tag *); 1031 1032 static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt, 1033 int tag) 1034 { 1035 if (unlikely(bqt == NULL || tag >= bqt->real_max_depth)) 1036 return NULL; 1037 return bqt->tag_index[tag]; 1038 } 1039 1040 #define BLKDEV_DISCARD_SECURE 0x01 /* secure discard */ 1041 1042 extern int blkdev_issue_flush(struct block_device *, gfp_t, sector_t *); 1043 extern int blkdev_issue_discard(struct block_device *bdev, sector_t sector, 1044 sector_t nr_sects, gfp_t gfp_mask, unsigned long flags); 1045 extern int blkdev_issue_write_same(struct block_device *bdev, sector_t sector, 1046 sector_t nr_sects, gfp_t gfp_mask, struct page *page); 1047 extern int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector, 1048 sector_t nr_sects, gfp_t gfp_mask); 1049 static inline int sb_issue_discard(struct super_block *sb, sector_t block, 1050 sector_t nr_blocks, gfp_t gfp_mask, unsigned long flags) 1051 { 1052 return blkdev_issue_discard(sb->s_bdev, block << (sb->s_blocksize_bits - 9), 1053 nr_blocks << (sb->s_blocksize_bits - 9), 1054 gfp_mask, flags); 1055 } 1056 static inline int sb_issue_zeroout(struct super_block *sb, sector_t block, 1057 sector_t nr_blocks, gfp_t gfp_mask) 1058 { 1059 return blkdev_issue_zeroout(sb->s_bdev, 1060 block << (sb->s_blocksize_bits - 9), 1061 nr_blocks << (sb->s_blocksize_bits - 9), 1062 gfp_mask); 1063 } 1064 1065 extern int blk_verify_command(unsigned char *cmd, fmode_t has_write_perm); 1066 1067 enum blk_default_limits { 1068 BLK_MAX_SEGMENTS = 128, 1069 BLK_SAFE_MAX_SECTORS = 255, 1070 BLK_DEF_MAX_SECTORS = 1024, 1071 BLK_MAX_SEGMENT_SIZE = 65536, 1072 BLK_SEG_BOUNDARY_MASK = 0xFFFFFFFFUL, 1073 }; 1074 1075 #define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist) 1076 1077 static inline unsigned long queue_bounce_pfn(struct request_queue *q) 1078 { 1079 return q->limits.bounce_pfn; 1080 } 1081 1082 static inline unsigned long queue_segment_boundary(struct request_queue *q) 1083 { 1084 return q->limits.seg_boundary_mask; 1085 } 1086 1087 static inline unsigned int queue_max_sectors(struct request_queue *q) 1088 { 1089 return q->limits.max_sectors; 1090 } 1091 1092 static inline unsigned int queue_max_hw_sectors(struct request_queue *q) 1093 { 1094 return q->limits.max_hw_sectors; 1095 } 1096 1097 static inline unsigned short queue_max_segments(struct request_queue *q) 1098 { 1099 return q->limits.max_segments; 1100 } 1101 1102 static inline unsigned int queue_max_segment_size(struct request_queue *q) 1103 { 1104 return q->limits.max_segment_size; 1105 } 1106 1107 static inline unsigned short queue_logical_block_size(struct request_queue *q) 1108 { 1109 int retval = 512; 1110 1111 if (q && q->limits.logical_block_size) 1112 retval = q->limits.logical_block_size; 1113 1114 return retval; 1115 } 1116 1117 static inline unsigned short bdev_logical_block_size(struct block_device *bdev) 1118 { 1119 return queue_logical_block_size(bdev_get_queue(bdev)); 1120 } 1121 1122 static inline unsigned int queue_physical_block_size(struct request_queue *q) 1123 { 1124 return q->limits.physical_block_size; 1125 } 1126 1127 static inline unsigned int bdev_physical_block_size(struct block_device *bdev) 1128 { 1129 return queue_physical_block_size(bdev_get_queue(bdev)); 1130 } 1131 1132 static inline unsigned int queue_io_min(struct request_queue *q) 1133 { 1134 return q->limits.io_min; 1135 } 1136 1137 static inline int bdev_io_min(struct block_device *bdev) 1138 { 1139 return queue_io_min(bdev_get_queue(bdev)); 1140 } 1141 1142 static inline unsigned int queue_io_opt(struct request_queue *q) 1143 { 1144 return q->limits.io_opt; 1145 } 1146 1147 static inline int bdev_io_opt(struct block_device *bdev) 1148 { 1149 return queue_io_opt(bdev_get_queue(bdev)); 1150 } 1151 1152 static inline int queue_alignment_offset(struct request_queue *q) 1153 { 1154 if (q->limits.misaligned) 1155 return -1; 1156 1157 return q->limits.alignment_offset; 1158 } 1159 1160 static inline int queue_limit_alignment_offset(struct queue_limits *lim, sector_t sector) 1161 { 1162 unsigned int granularity = max(lim->physical_block_size, lim->io_min); 1163 unsigned int alignment = (sector << 9) & (granularity - 1); 1164 1165 return (granularity + lim->alignment_offset - alignment) 1166 & (granularity - 1); 1167 } 1168 1169 static inline int bdev_alignment_offset(struct block_device *bdev) 1170 { 1171 struct request_queue *q = bdev_get_queue(bdev); 1172 1173 if (q->limits.misaligned) 1174 return -1; 1175 1176 if (bdev != bdev->bd_contains) 1177 return bdev->bd_part->alignment_offset; 1178 1179 return q->limits.alignment_offset; 1180 } 1181 1182 static inline int queue_discard_alignment(struct request_queue *q) 1183 { 1184 if (q->limits.discard_misaligned) 1185 return -1; 1186 1187 return q->limits.discard_alignment; 1188 } 1189 1190 static inline int queue_limit_discard_alignment(struct queue_limits *lim, sector_t sector) 1191 { 1192 unsigned int alignment, granularity, offset; 1193 1194 if (!lim->max_discard_sectors) 1195 return 0; 1196 1197 /* Why are these in bytes, not sectors? */ 1198 alignment = lim->discard_alignment >> 9; 1199 granularity = lim->discard_granularity >> 9; 1200 if (!granularity) 1201 return 0; 1202 1203 /* Offset of the partition start in 'granularity' sectors */ 1204 offset = sector_div(sector, granularity); 1205 1206 /* And why do we do this modulus *again* in blkdev_issue_discard()? */ 1207 offset = (granularity + alignment - offset) % granularity; 1208 1209 /* Turn it back into bytes, gaah */ 1210 return offset << 9; 1211 } 1212 1213 static inline int bdev_discard_alignment(struct block_device *bdev) 1214 { 1215 struct request_queue *q = bdev_get_queue(bdev); 1216 1217 if (bdev != bdev->bd_contains) 1218 return bdev->bd_part->discard_alignment; 1219 1220 return q->limits.discard_alignment; 1221 } 1222 1223 static inline unsigned int queue_discard_zeroes_data(struct request_queue *q) 1224 { 1225 if (q->limits.max_discard_sectors && q->limits.discard_zeroes_data == 1) 1226 return 1; 1227 1228 return 0; 1229 } 1230 1231 static inline unsigned int bdev_discard_zeroes_data(struct block_device *bdev) 1232 { 1233 return queue_discard_zeroes_data(bdev_get_queue(bdev)); 1234 } 1235 1236 static inline unsigned int bdev_write_same(struct block_device *bdev) 1237 { 1238 struct request_queue *q = bdev_get_queue(bdev); 1239 1240 if (q) 1241 return q->limits.max_write_same_sectors; 1242 1243 return 0; 1244 } 1245 1246 static inline int queue_dma_alignment(struct request_queue *q) 1247 { 1248 return q ? q->dma_alignment : 511; 1249 } 1250 1251 static inline int blk_rq_aligned(struct request_queue *q, unsigned long addr, 1252 unsigned int len) 1253 { 1254 unsigned int alignment = queue_dma_alignment(q) | q->dma_pad_mask; 1255 return !(addr & alignment) && !(len & alignment); 1256 } 1257 1258 /* assumes size > 256 */ 1259 static inline unsigned int blksize_bits(unsigned int size) 1260 { 1261 unsigned int bits = 8; 1262 do { 1263 bits++; 1264 size >>= 1; 1265 } while (size > 256); 1266 return bits; 1267 } 1268 1269 static inline unsigned int block_size(struct block_device *bdev) 1270 { 1271 return bdev->bd_block_size; 1272 } 1273 1274 static inline bool queue_flush_queueable(struct request_queue *q) 1275 { 1276 return !q->flush_not_queueable; 1277 } 1278 1279 typedef struct {struct page *v;} Sector; 1280 1281 unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *); 1282 1283 static inline void put_dev_sector(Sector p) 1284 { 1285 page_cache_release(p.v); 1286 } 1287 1288 struct work_struct; 1289 int kblockd_schedule_work(struct request_queue *q, struct work_struct *work); 1290 1291 #ifdef CONFIG_BLK_CGROUP 1292 /* 1293 * This should not be using sched_clock(). A real patch is in progress 1294 * to fix this up, until that is in place we need to disable preemption 1295 * around sched_clock() in this function and set_io_start_time_ns(). 1296 */ 1297 static inline void set_start_time_ns(struct request *req) 1298 { 1299 preempt_disable(); 1300 req->start_time_ns = sched_clock(); 1301 preempt_enable(); 1302 } 1303 1304 static inline void set_io_start_time_ns(struct request *req) 1305 { 1306 preempt_disable(); 1307 req->io_start_time_ns = sched_clock(); 1308 preempt_enable(); 1309 } 1310 1311 static inline uint64_t rq_start_time_ns(struct request *req) 1312 { 1313 return req->start_time_ns; 1314 } 1315 1316 static inline uint64_t rq_io_start_time_ns(struct request *req) 1317 { 1318 return req->io_start_time_ns; 1319 } 1320 #else 1321 static inline void set_start_time_ns(struct request *req) {} 1322 static inline void set_io_start_time_ns(struct request *req) {} 1323 static inline uint64_t rq_start_time_ns(struct request *req) 1324 { 1325 return 0; 1326 } 1327 static inline uint64_t rq_io_start_time_ns(struct request *req) 1328 { 1329 return 0; 1330 } 1331 #endif 1332 1333 #define MODULE_ALIAS_BLOCKDEV(major,minor) \ 1334 MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor)) 1335 #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \ 1336 MODULE_ALIAS("block-major-" __stringify(major) "-*") 1337 1338 #if defined(CONFIG_BLK_DEV_INTEGRITY) 1339 1340 #define INTEGRITY_FLAG_READ 2 /* verify data integrity on read */ 1341 #define INTEGRITY_FLAG_WRITE 4 /* generate data integrity on write */ 1342 1343 struct blk_integrity_exchg { 1344 void *prot_buf; 1345 void *data_buf; 1346 sector_t sector; 1347 unsigned int data_size; 1348 unsigned short sector_size; 1349 const char *disk_name; 1350 }; 1351 1352 typedef void (integrity_gen_fn) (struct blk_integrity_exchg *); 1353 typedef int (integrity_vrfy_fn) (struct blk_integrity_exchg *); 1354 typedef void (integrity_set_tag_fn) (void *, void *, unsigned int); 1355 typedef void (integrity_get_tag_fn) (void *, void *, unsigned int); 1356 1357 struct blk_integrity { 1358 integrity_gen_fn *generate_fn; 1359 integrity_vrfy_fn *verify_fn; 1360 integrity_set_tag_fn *set_tag_fn; 1361 integrity_get_tag_fn *get_tag_fn; 1362 1363 unsigned short flags; 1364 unsigned short tuple_size; 1365 unsigned short sector_size; 1366 unsigned short tag_size; 1367 1368 const char *name; 1369 1370 struct kobject kobj; 1371 }; 1372 1373 extern bool blk_integrity_is_initialized(struct gendisk *); 1374 extern int blk_integrity_register(struct gendisk *, struct blk_integrity *); 1375 extern void blk_integrity_unregister(struct gendisk *); 1376 extern int blk_integrity_compare(struct gendisk *, struct gendisk *); 1377 extern int blk_rq_map_integrity_sg(struct request_queue *, struct bio *, 1378 struct scatterlist *); 1379 extern int blk_rq_count_integrity_sg(struct request_queue *, struct bio *); 1380 extern int blk_integrity_merge_rq(struct request_queue *, struct request *, 1381 struct request *); 1382 extern int blk_integrity_merge_bio(struct request_queue *, struct request *, 1383 struct bio *); 1384 1385 static inline 1386 struct blk_integrity *bdev_get_integrity(struct block_device *bdev) 1387 { 1388 return bdev->bd_disk->integrity; 1389 } 1390 1391 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk) 1392 { 1393 return disk->integrity; 1394 } 1395 1396 static inline int blk_integrity_rq(struct request *rq) 1397 { 1398 if (rq->bio == NULL) 1399 return 0; 1400 1401 return bio_integrity(rq->bio); 1402 } 1403 1404 static inline void blk_queue_max_integrity_segments(struct request_queue *q, 1405 unsigned int segs) 1406 { 1407 q->limits.max_integrity_segments = segs; 1408 } 1409 1410 static inline unsigned short 1411 queue_max_integrity_segments(struct request_queue *q) 1412 { 1413 return q->limits.max_integrity_segments; 1414 } 1415 1416 #else /* CONFIG_BLK_DEV_INTEGRITY */ 1417 1418 struct bio; 1419 struct block_device; 1420 struct gendisk; 1421 struct blk_integrity; 1422 1423 static inline int blk_integrity_rq(struct request *rq) 1424 { 1425 return 0; 1426 } 1427 static inline int blk_rq_count_integrity_sg(struct request_queue *q, 1428 struct bio *b) 1429 { 1430 return 0; 1431 } 1432 static inline int blk_rq_map_integrity_sg(struct request_queue *q, 1433 struct bio *b, 1434 struct scatterlist *s) 1435 { 1436 return 0; 1437 } 1438 static inline struct blk_integrity *bdev_get_integrity(struct block_device *b) 1439 { 1440 return 0; 1441 } 1442 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk) 1443 { 1444 return NULL; 1445 } 1446 static inline int blk_integrity_compare(struct gendisk *a, struct gendisk *b) 1447 { 1448 return 0; 1449 } 1450 static inline int blk_integrity_register(struct gendisk *d, 1451 struct blk_integrity *b) 1452 { 1453 return 0; 1454 } 1455 static inline void blk_integrity_unregister(struct gendisk *d) 1456 { 1457 } 1458 static inline void blk_queue_max_integrity_segments(struct request_queue *q, 1459 unsigned int segs) 1460 { 1461 } 1462 static inline unsigned short queue_max_integrity_segments(struct request_queue *q) 1463 { 1464 return 0; 1465 } 1466 static inline int blk_integrity_merge_rq(struct request_queue *rq, 1467 struct request *r1, 1468 struct request *r2) 1469 { 1470 return 0; 1471 } 1472 static inline int blk_integrity_merge_bio(struct request_queue *rq, 1473 struct request *r, 1474 struct bio *b) 1475 { 1476 return 0; 1477 } 1478 static inline bool blk_integrity_is_initialized(struct gendisk *g) 1479 { 1480 return 0; 1481 } 1482 1483 #endif /* CONFIG_BLK_DEV_INTEGRITY */ 1484 1485 struct block_device_operations { 1486 int (*open) (struct block_device *, fmode_t); 1487 int (*release) (struct gendisk *, fmode_t); 1488 int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long); 1489 int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long); 1490 int (*direct_access) (struct block_device *, sector_t, 1491 void **, unsigned long *); 1492 unsigned int (*check_events) (struct gendisk *disk, 1493 unsigned int clearing); 1494 /* ->media_changed() is DEPRECATED, use ->check_events() instead */ 1495 int (*media_changed) (struct gendisk *); 1496 void (*unlock_native_capacity) (struct gendisk *); 1497 int (*revalidate_disk) (struct gendisk *); 1498 int (*getgeo)(struct block_device *, struct hd_geometry *); 1499 /* this callback is with swap_lock and sometimes page table lock held */ 1500 void (*swap_slot_free_notify) (struct block_device *, unsigned long); 1501 struct module *owner; 1502 }; 1503 1504 extern int __blkdev_driver_ioctl(struct block_device *, fmode_t, unsigned int, 1505 unsigned long); 1506 #else /* CONFIG_BLOCK */ 1507 /* 1508 * stubs for when the block layer is configured out 1509 */ 1510 #define buffer_heads_over_limit 0 1511 1512 static inline long nr_blockdev_pages(void) 1513 { 1514 return 0; 1515 } 1516 1517 struct blk_plug { 1518 }; 1519 1520 static inline void blk_start_plug(struct blk_plug *plug) 1521 { 1522 } 1523 1524 static inline void blk_finish_plug(struct blk_plug *plug) 1525 { 1526 } 1527 1528 static inline void blk_flush_plug(struct task_struct *task) 1529 { 1530 } 1531 1532 static inline void blk_schedule_flush_plug(struct task_struct *task) 1533 { 1534 } 1535 1536 1537 static inline bool blk_needs_flush_plug(struct task_struct *tsk) 1538 { 1539 return false; 1540 } 1541 1542 #endif /* CONFIG_BLOCK */ 1543 1544 #endif 1545