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