1 #ifndef _LINUX_BLKDEV_H 2 #define _LINUX_BLKDEV_H 3 4 #include <linux/sched.h> 5 6 #ifdef CONFIG_BLOCK 7 8 #include <linux/major.h> 9 #include <linux/genhd.h> 10 #include <linux/list.h> 11 #include <linux/llist.h> 12 #include <linux/timer.h> 13 #include <linux/workqueue.h> 14 #include <linux/pagemap.h> 15 #include <linux/backing-dev.h> 16 #include <linux/wait.h> 17 #include <linux/mempool.h> 18 #include <linux/bio.h> 19 #include <linux/stringify.h> 20 #include <linux/gfp.h> 21 #include <linux/bsg.h> 22 #include <linux/smp.h> 23 #include <linux/rcupdate.h> 24 25 #include <asm/scatterlist.h> 26 27 struct module; 28 struct scsi_ioctl_command; 29 30 struct request_queue; 31 struct elevator_queue; 32 struct request_pm_state; 33 struct blk_trace; 34 struct request; 35 struct sg_io_hdr; 36 struct bsg_job; 37 struct blkcg_gq; 38 39 #define BLKDEV_MIN_RQ 4 40 #define BLKDEV_MAX_RQ 128 /* Default maximum */ 41 42 /* 43 * Maximum number of blkcg policies allowed to be registered concurrently. 44 * Defined here to simplify include dependency. 45 */ 46 #define BLKCG_MAX_POLS 2 47 48 struct request; 49 typedef void (rq_end_io_fn)(struct request *, int); 50 51 #define BLK_RL_SYNCFULL (1U << 0) 52 #define BLK_RL_ASYNCFULL (1U << 1) 53 54 struct request_list { 55 struct request_queue *q; /* the queue this rl belongs to */ 56 #ifdef CONFIG_BLK_CGROUP 57 struct blkcg_gq *blkg; /* blkg this request pool belongs to */ 58 #endif 59 /* 60 * count[], starved[], and wait[] are indexed by 61 * BLK_RW_SYNC/BLK_RW_ASYNC 62 */ 63 int count[2]; 64 int starved[2]; 65 mempool_t *rq_pool; 66 wait_queue_head_t wait[2]; 67 unsigned int flags; 68 }; 69 70 /* 71 * request command types 72 */ 73 enum rq_cmd_type_bits { 74 REQ_TYPE_FS = 1, /* fs request */ 75 REQ_TYPE_BLOCK_PC, /* scsi command */ 76 REQ_TYPE_SENSE, /* sense request */ 77 REQ_TYPE_PM_SUSPEND, /* suspend request */ 78 REQ_TYPE_PM_RESUME, /* resume request */ 79 REQ_TYPE_PM_SHUTDOWN, /* shutdown request */ 80 REQ_TYPE_SPECIAL, /* driver defined type */ 81 /* 82 * for ATA/ATAPI devices. this really doesn't belong here, ide should 83 * use REQ_TYPE_SPECIAL and use rq->cmd[0] with the range of driver 84 * private REQ_LB opcodes to differentiate what type of request this is 85 */ 86 REQ_TYPE_ATA_TASKFILE, 87 REQ_TYPE_ATA_PC, 88 }; 89 90 #define BLK_MAX_CDB 16 91 92 /* 93 * try to put the fields that are referenced together in the same cacheline. 94 * if you modify this structure, be sure to check block/blk-core.c:blk_rq_init() 95 * as well! 96 */ 97 struct request { 98 union { 99 struct list_head queuelist; 100 struct llist_node ll_list; 101 }; 102 union { 103 struct call_single_data csd; 104 struct work_struct mq_flush_data; 105 }; 106 107 struct request_queue *q; 108 struct blk_mq_ctx *mq_ctx; 109 110 u64 cmd_flags; 111 enum rq_cmd_type_bits cmd_type; 112 unsigned long atomic_flags; 113 114 int cpu; 115 116 /* the following two fields are internal, NEVER access directly */ 117 unsigned int __data_len; /* total data len */ 118 sector_t __sector; /* sector cursor */ 119 120 struct bio *bio; 121 struct bio *biotail; 122 123 struct hlist_node hash; /* merge hash */ 124 /* 125 * The rb_node is only used inside the io scheduler, requests 126 * are pruned when moved to the dispatch queue. So let the 127 * completion_data share space with the rb_node. 128 */ 129 union { 130 struct rb_node rb_node; /* sort/lookup */ 131 void *completion_data; 132 }; 133 134 /* 135 * Three pointers are available for the IO schedulers, if they need 136 * more they have to dynamically allocate it. Flush requests are 137 * never put on the IO scheduler. So let the flush fields share 138 * space with the elevator data. 139 */ 140 union { 141 struct { 142 struct io_cq *icq; 143 void *priv[2]; 144 } elv; 145 146 struct { 147 unsigned int seq; 148 struct list_head list; 149 rq_end_io_fn *saved_end_io; 150 } flush; 151 }; 152 153 struct gendisk *rq_disk; 154 struct hd_struct *part; 155 unsigned long start_time; 156 #ifdef CONFIG_BLK_CGROUP 157 struct request_list *rl; /* rl this rq is alloced from */ 158 unsigned long long start_time_ns; 159 unsigned long long io_start_time_ns; /* when passed to hardware */ 160 #endif 161 /* Number of scatter-gather DMA addr+len pairs after 162 * physical address coalescing is performed. 163 */ 164 unsigned short nr_phys_segments; 165 #if defined(CONFIG_BLK_DEV_INTEGRITY) 166 unsigned short nr_integrity_segments; 167 #endif 168 169 unsigned short ioprio; 170 171 void *special; /* opaque pointer available for LLD use */ 172 char *buffer; /* kaddr of the current segment if available */ 173 174 int tag; 175 int errors; 176 177 /* 178 * when request is used as a packet command carrier 179 */ 180 unsigned char __cmd[BLK_MAX_CDB]; 181 unsigned char *cmd; 182 unsigned short cmd_len; 183 184 unsigned int extra_len; /* length of alignment and padding */ 185 unsigned int sense_len; 186 unsigned int resid_len; /* residual count */ 187 void *sense; 188 189 unsigned long deadline; 190 struct list_head timeout_list; 191 unsigned int timeout; 192 int retries; 193 194 /* 195 * completion callback. 196 */ 197 rq_end_io_fn *end_io; 198 void *end_io_data; 199 200 /* for bidi */ 201 struct request *next_rq; 202 }; 203 204 static inline unsigned short req_get_ioprio(struct request *req) 205 { 206 return req->ioprio; 207 } 208 209 /* 210 * State information carried for REQ_TYPE_PM_SUSPEND and REQ_TYPE_PM_RESUME 211 * requests. Some step values could eventually be made generic. 212 */ 213 struct request_pm_state 214 { 215 /* PM state machine step value, currently driver specific */ 216 int pm_step; 217 /* requested PM state value (S1, S2, S3, S4, ...) */ 218 u32 pm_state; 219 void* data; /* for driver use */ 220 }; 221 222 #include <linux/elevator.h> 223 224 struct blk_queue_ctx; 225 226 typedef void (request_fn_proc) (struct request_queue *q); 227 typedef void (make_request_fn) (struct request_queue *q, struct bio *bio); 228 typedef int (prep_rq_fn) (struct request_queue *, struct request *); 229 typedef void (unprep_rq_fn) (struct request_queue *, struct request *); 230 231 struct bio_vec; 232 struct bvec_merge_data { 233 struct block_device *bi_bdev; 234 sector_t bi_sector; 235 unsigned bi_size; 236 unsigned long bi_rw; 237 }; 238 typedef int (merge_bvec_fn) (struct request_queue *, struct bvec_merge_data *, 239 struct bio_vec *); 240 typedef void (softirq_done_fn)(struct request *); 241 typedef int (dma_drain_needed_fn)(struct request *); 242 typedef int (lld_busy_fn) (struct request_queue *q); 243 typedef int (bsg_job_fn) (struct bsg_job *); 244 245 enum blk_eh_timer_return { 246 BLK_EH_NOT_HANDLED, 247 BLK_EH_HANDLED, 248 BLK_EH_RESET_TIMER, 249 }; 250 251 typedef enum blk_eh_timer_return (rq_timed_out_fn)(struct request *); 252 253 enum blk_queue_state { 254 Queue_down, 255 Queue_up, 256 }; 257 258 struct blk_queue_tag { 259 struct request **tag_index; /* map of busy tags */ 260 unsigned long *tag_map; /* bit map of free/busy tags */ 261 int busy; /* current depth */ 262 int max_depth; /* what we will send to device */ 263 int real_max_depth; /* what the array can hold */ 264 atomic_t refcnt; /* map can be shared */ 265 }; 266 267 #define BLK_SCSI_MAX_CMDS (256) 268 #define BLK_SCSI_CMD_PER_LONG (BLK_SCSI_MAX_CMDS / (sizeof(long) * 8)) 269 270 struct queue_limits { 271 unsigned long bounce_pfn; 272 unsigned long seg_boundary_mask; 273 274 unsigned int max_hw_sectors; 275 unsigned int max_sectors; 276 unsigned int max_segment_size; 277 unsigned int physical_block_size; 278 unsigned int alignment_offset; 279 unsigned int io_min; 280 unsigned int io_opt; 281 unsigned int max_discard_sectors; 282 unsigned int max_write_same_sectors; 283 unsigned int discard_granularity; 284 unsigned int discard_alignment; 285 286 unsigned short logical_block_size; 287 unsigned short max_segments; 288 unsigned short max_integrity_segments; 289 290 unsigned char misaligned; 291 unsigned char discard_misaligned; 292 unsigned char cluster; 293 unsigned char discard_zeroes_data; 294 }; 295 296 struct request_queue { 297 /* 298 * Together with queue_head for cacheline sharing 299 */ 300 struct list_head queue_head; 301 struct request *last_merge; 302 struct elevator_queue *elevator; 303 int nr_rqs[2]; /* # allocated [a]sync rqs */ 304 int nr_rqs_elvpriv; /* # allocated rqs w/ elvpriv */ 305 306 /* 307 * If blkcg is not used, @q->root_rl serves all requests. If blkcg 308 * is used, root blkg allocates from @q->root_rl and all other 309 * blkgs from their own blkg->rl. Which one to use should be 310 * determined using bio_request_list(). 311 */ 312 struct request_list root_rl; 313 314 request_fn_proc *request_fn; 315 make_request_fn *make_request_fn; 316 prep_rq_fn *prep_rq_fn; 317 unprep_rq_fn *unprep_rq_fn; 318 merge_bvec_fn *merge_bvec_fn; 319 softirq_done_fn *softirq_done_fn; 320 rq_timed_out_fn *rq_timed_out_fn; 321 dma_drain_needed_fn *dma_drain_needed; 322 lld_busy_fn *lld_busy_fn; 323 324 struct blk_mq_ops *mq_ops; 325 326 unsigned int *mq_map; 327 328 /* sw queues */ 329 struct blk_mq_ctx *queue_ctx; 330 unsigned int nr_queues; 331 332 /* hw dispatch queues */ 333 struct blk_mq_hw_ctx **queue_hw_ctx; 334 unsigned int nr_hw_queues; 335 336 /* 337 * Dispatch queue sorting 338 */ 339 sector_t end_sector; 340 struct request *boundary_rq; 341 342 /* 343 * Delayed queue handling 344 */ 345 struct delayed_work delay_work; 346 347 struct backing_dev_info backing_dev_info; 348 349 /* 350 * The queue owner gets to use this for whatever they like. 351 * ll_rw_blk doesn't touch it. 352 */ 353 void *queuedata; 354 355 /* 356 * various queue flags, see QUEUE_* below 357 */ 358 unsigned long queue_flags; 359 360 /* 361 * ida allocated id for this queue. Used to index queues from 362 * ioctx. 363 */ 364 int id; 365 366 /* 367 * queue needs bounce pages for pages above this limit 368 */ 369 gfp_t bounce_gfp; 370 371 /* 372 * protects queue structures from reentrancy. ->__queue_lock should 373 * _never_ be used directly, it is queue private. always use 374 * ->queue_lock. 375 */ 376 spinlock_t __queue_lock; 377 spinlock_t *queue_lock; 378 379 /* 380 * queue kobject 381 */ 382 struct kobject kobj; 383 384 /* 385 * mq queue kobject 386 */ 387 struct kobject mq_kobj; 388 389 #ifdef CONFIG_PM_RUNTIME 390 struct device *dev; 391 int rpm_status; 392 unsigned int nr_pending; 393 #endif 394 395 /* 396 * queue settings 397 */ 398 unsigned long nr_requests; /* Max # of requests */ 399 unsigned int nr_congestion_on; 400 unsigned int nr_congestion_off; 401 unsigned int nr_batching; 402 403 unsigned int dma_drain_size; 404 void *dma_drain_buffer; 405 unsigned int dma_pad_mask; 406 unsigned int dma_alignment; 407 408 struct blk_queue_tag *queue_tags; 409 struct list_head tag_busy_list; 410 411 unsigned int nr_sorted; 412 unsigned int in_flight[2]; 413 /* 414 * Number of active block driver functions for which blk_drain_queue() 415 * must wait. Must be incremented around functions that unlock the 416 * queue_lock internally, e.g. scsi_request_fn(). 417 */ 418 unsigned int request_fn_active; 419 420 unsigned int rq_timeout; 421 struct timer_list timeout; 422 struct list_head timeout_list; 423 424 struct list_head icq_list; 425 #ifdef CONFIG_BLK_CGROUP 426 DECLARE_BITMAP (blkcg_pols, BLKCG_MAX_POLS); 427 struct blkcg_gq *root_blkg; 428 struct list_head blkg_list; 429 #endif 430 431 struct queue_limits limits; 432 433 /* 434 * sg stuff 435 */ 436 unsigned int sg_timeout; 437 unsigned int sg_reserved_size; 438 int node; 439 #ifdef CONFIG_BLK_DEV_IO_TRACE 440 struct blk_trace *blk_trace; 441 #endif 442 /* 443 * for flush operations 444 */ 445 unsigned int flush_flags; 446 unsigned int flush_not_queueable:1; 447 unsigned int flush_queue_delayed:1; 448 unsigned int flush_pending_idx:1; 449 unsigned int flush_running_idx:1; 450 unsigned long flush_pending_since; 451 struct list_head flush_queue[2]; 452 struct list_head flush_data_in_flight; 453 union { 454 struct request flush_rq; 455 struct { 456 spinlock_t mq_flush_lock; 457 struct work_struct mq_flush_work; 458 }; 459 }; 460 461 struct mutex sysfs_lock; 462 463 int bypass_depth; 464 465 #if defined(CONFIG_BLK_DEV_BSG) 466 bsg_job_fn *bsg_job_fn; 467 int bsg_job_size; 468 struct bsg_class_device bsg_dev; 469 #endif 470 471 #ifdef CONFIG_BLK_DEV_THROTTLING 472 /* Throttle data */ 473 struct throtl_data *td; 474 #endif 475 struct rcu_head rcu_head; 476 wait_queue_head_t mq_freeze_wq; 477 struct percpu_counter mq_usage_counter; 478 struct list_head all_q_node; 479 }; 480 481 #define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */ 482 #define QUEUE_FLAG_STOPPED 2 /* queue is stopped */ 483 #define QUEUE_FLAG_SYNCFULL 3 /* read queue has been filled */ 484 #define QUEUE_FLAG_ASYNCFULL 4 /* write queue has been filled */ 485 #define QUEUE_FLAG_DYING 5 /* queue being torn down */ 486 #define QUEUE_FLAG_BYPASS 6 /* act as dumb FIFO queue */ 487 #define QUEUE_FLAG_BIDI 7 /* queue supports bidi requests */ 488 #define QUEUE_FLAG_NOMERGES 8 /* disable merge attempts */ 489 #define QUEUE_FLAG_SAME_COMP 9 /* complete on same CPU-group */ 490 #define QUEUE_FLAG_FAIL_IO 10 /* fake timeout */ 491 #define QUEUE_FLAG_STACKABLE 11 /* supports request stacking */ 492 #define QUEUE_FLAG_NONROT 12 /* non-rotational device (SSD) */ 493 #define QUEUE_FLAG_VIRT QUEUE_FLAG_NONROT /* paravirt device */ 494 #define QUEUE_FLAG_IO_STAT 13 /* do IO stats */ 495 #define QUEUE_FLAG_DISCARD 14 /* supports DISCARD */ 496 #define QUEUE_FLAG_NOXMERGES 15 /* No extended merges */ 497 #define QUEUE_FLAG_ADD_RANDOM 16 /* Contributes to random pool */ 498 #define QUEUE_FLAG_SECDISCARD 17 /* supports SECDISCARD */ 499 #define QUEUE_FLAG_SAME_FORCE 18 /* force complete on same CPU */ 500 #define QUEUE_FLAG_DEAD 19 /* queue tear-down finished */ 501 #define QUEUE_FLAG_INIT_DONE 20 /* queue is initialized */ 502 503 #define QUEUE_FLAG_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \ 504 (1 << QUEUE_FLAG_STACKABLE) | \ 505 (1 << QUEUE_FLAG_SAME_COMP) | \ 506 (1 << QUEUE_FLAG_ADD_RANDOM)) 507 508 #define QUEUE_FLAG_MQ_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \ 509 (1 << QUEUE_FLAG_SAME_COMP)) 510 511 static inline void queue_lockdep_assert_held(struct request_queue *q) 512 { 513 if (q->queue_lock) 514 lockdep_assert_held(q->queue_lock); 515 } 516 517 static inline void queue_flag_set_unlocked(unsigned int flag, 518 struct request_queue *q) 519 { 520 __set_bit(flag, &q->queue_flags); 521 } 522 523 static inline int queue_flag_test_and_clear(unsigned int flag, 524 struct request_queue *q) 525 { 526 queue_lockdep_assert_held(q); 527 528 if (test_bit(flag, &q->queue_flags)) { 529 __clear_bit(flag, &q->queue_flags); 530 return 1; 531 } 532 533 return 0; 534 } 535 536 static inline int queue_flag_test_and_set(unsigned int flag, 537 struct request_queue *q) 538 { 539 queue_lockdep_assert_held(q); 540 541 if (!test_bit(flag, &q->queue_flags)) { 542 __set_bit(flag, &q->queue_flags); 543 return 0; 544 } 545 546 return 1; 547 } 548 549 static inline void queue_flag_set(unsigned int flag, struct request_queue *q) 550 { 551 queue_lockdep_assert_held(q); 552 __set_bit(flag, &q->queue_flags); 553 } 554 555 static inline void queue_flag_clear_unlocked(unsigned int flag, 556 struct request_queue *q) 557 { 558 __clear_bit(flag, &q->queue_flags); 559 } 560 561 static inline int queue_in_flight(struct request_queue *q) 562 { 563 return q->in_flight[0] + q->in_flight[1]; 564 } 565 566 static inline void queue_flag_clear(unsigned int flag, struct request_queue *q) 567 { 568 queue_lockdep_assert_held(q); 569 __clear_bit(flag, &q->queue_flags); 570 } 571 572 #define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags) 573 #define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags) 574 #define blk_queue_dying(q) test_bit(QUEUE_FLAG_DYING, &(q)->queue_flags) 575 #define blk_queue_dead(q) test_bit(QUEUE_FLAG_DEAD, &(q)->queue_flags) 576 #define blk_queue_bypass(q) test_bit(QUEUE_FLAG_BYPASS, &(q)->queue_flags) 577 #define blk_queue_init_done(q) test_bit(QUEUE_FLAG_INIT_DONE, &(q)->queue_flags) 578 #define blk_queue_nomerges(q) test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags) 579 #define blk_queue_noxmerges(q) \ 580 test_bit(QUEUE_FLAG_NOXMERGES, &(q)->queue_flags) 581 #define blk_queue_nonrot(q) test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags) 582 #define blk_queue_io_stat(q) test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags) 583 #define blk_queue_add_random(q) test_bit(QUEUE_FLAG_ADD_RANDOM, &(q)->queue_flags) 584 #define blk_queue_stackable(q) \ 585 test_bit(QUEUE_FLAG_STACKABLE, &(q)->queue_flags) 586 #define blk_queue_discard(q) test_bit(QUEUE_FLAG_DISCARD, &(q)->queue_flags) 587 #define blk_queue_secdiscard(q) (blk_queue_discard(q) && \ 588 test_bit(QUEUE_FLAG_SECDISCARD, &(q)->queue_flags)) 589 590 #define blk_noretry_request(rq) \ 591 ((rq)->cmd_flags & (REQ_FAILFAST_DEV|REQ_FAILFAST_TRANSPORT| \ 592 REQ_FAILFAST_DRIVER)) 593 594 #define blk_account_rq(rq) \ 595 (((rq)->cmd_flags & REQ_STARTED) && \ 596 ((rq)->cmd_type == REQ_TYPE_FS)) 597 598 #define blk_pm_request(rq) \ 599 ((rq)->cmd_type == REQ_TYPE_PM_SUSPEND || \ 600 (rq)->cmd_type == REQ_TYPE_PM_RESUME) 601 602 #define blk_rq_cpu_valid(rq) ((rq)->cpu != -1) 603 #define blk_bidi_rq(rq) ((rq)->next_rq != NULL) 604 /* rq->queuelist of dequeued request must be list_empty() */ 605 #define blk_queued_rq(rq) (!list_empty(&(rq)->queuelist)) 606 607 #define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist) 608 609 #define rq_data_dir(rq) (((rq)->cmd_flags & 1) != 0) 610 611 static inline unsigned int blk_queue_cluster(struct request_queue *q) 612 { 613 return q->limits.cluster; 614 } 615 616 /* 617 * We regard a request as sync, if either a read or a sync write 618 */ 619 static inline bool rw_is_sync(unsigned int rw_flags) 620 { 621 return !(rw_flags & REQ_WRITE) || (rw_flags & REQ_SYNC); 622 } 623 624 static inline bool rq_is_sync(struct request *rq) 625 { 626 return rw_is_sync(rq->cmd_flags); 627 } 628 629 static inline bool blk_rl_full(struct request_list *rl, bool sync) 630 { 631 unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL; 632 633 return rl->flags & flag; 634 } 635 636 static inline void blk_set_rl_full(struct request_list *rl, bool sync) 637 { 638 unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL; 639 640 rl->flags |= flag; 641 } 642 643 static inline void blk_clear_rl_full(struct request_list *rl, bool sync) 644 { 645 unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL; 646 647 rl->flags &= ~flag; 648 } 649 650 static inline bool rq_mergeable(struct request *rq) 651 { 652 if (rq->cmd_type != REQ_TYPE_FS) 653 return false; 654 655 if (rq->cmd_flags & REQ_NOMERGE_FLAGS) 656 return false; 657 658 return true; 659 } 660 661 static inline bool blk_check_merge_flags(unsigned int flags1, 662 unsigned int flags2) 663 { 664 if ((flags1 & REQ_DISCARD) != (flags2 & REQ_DISCARD)) 665 return false; 666 667 if ((flags1 & REQ_SECURE) != (flags2 & REQ_SECURE)) 668 return false; 669 670 if ((flags1 & REQ_WRITE_SAME) != (flags2 & REQ_WRITE_SAME)) 671 return false; 672 673 return true; 674 } 675 676 static inline bool blk_write_same_mergeable(struct bio *a, struct bio *b) 677 { 678 if (bio_data(a) == bio_data(b)) 679 return true; 680 681 return false; 682 } 683 684 /* 685 * q->prep_rq_fn return values 686 */ 687 #define BLKPREP_OK 0 /* serve it */ 688 #define BLKPREP_KILL 1 /* fatal error, kill */ 689 #define BLKPREP_DEFER 2 /* leave on queue */ 690 691 extern unsigned long blk_max_low_pfn, blk_max_pfn; 692 693 /* 694 * standard bounce addresses: 695 * 696 * BLK_BOUNCE_HIGH : bounce all highmem pages 697 * BLK_BOUNCE_ANY : don't bounce anything 698 * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary 699 */ 700 701 #if BITS_PER_LONG == 32 702 #define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT) 703 #else 704 #define BLK_BOUNCE_HIGH -1ULL 705 #endif 706 #define BLK_BOUNCE_ANY (-1ULL) 707 #define BLK_BOUNCE_ISA (DMA_BIT_MASK(24)) 708 709 /* 710 * default timeout for SG_IO if none specified 711 */ 712 #define BLK_DEFAULT_SG_TIMEOUT (60 * HZ) 713 #define BLK_MIN_SG_TIMEOUT (7 * HZ) 714 715 #ifdef CONFIG_BOUNCE 716 extern int init_emergency_isa_pool(void); 717 extern void blk_queue_bounce(struct request_queue *q, struct bio **bio); 718 #else 719 static inline int init_emergency_isa_pool(void) 720 { 721 return 0; 722 } 723 static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio) 724 { 725 } 726 #endif /* CONFIG_MMU */ 727 728 struct rq_map_data { 729 struct page **pages; 730 int page_order; 731 int nr_entries; 732 unsigned long offset; 733 int null_mapped; 734 int from_user; 735 }; 736 737 struct req_iterator { 738 int i; 739 struct bio *bio; 740 }; 741 742 /* This should not be used directly - use rq_for_each_segment */ 743 #define for_each_bio(_bio) \ 744 for (; _bio; _bio = _bio->bi_next) 745 #define __rq_for_each_bio(_bio, rq) \ 746 if ((rq->bio)) \ 747 for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next) 748 749 #define rq_for_each_segment(bvl, _rq, _iter) \ 750 __rq_for_each_bio(_iter.bio, _rq) \ 751 bio_for_each_segment(bvl, _iter.bio, _iter.i) 752 753 #define rq_iter_last(rq, _iter) \ 754 (_iter.bio->bi_next == NULL && _iter.i == _iter.bio->bi_vcnt-1) 755 756 #ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 757 # error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform" 758 #endif 759 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 760 extern void rq_flush_dcache_pages(struct request *rq); 761 #else 762 static inline void rq_flush_dcache_pages(struct request *rq) 763 { 764 } 765 #endif 766 767 extern int blk_register_queue(struct gendisk *disk); 768 extern void blk_unregister_queue(struct gendisk *disk); 769 extern void generic_make_request(struct bio *bio); 770 extern void blk_rq_init(struct request_queue *q, struct request *rq); 771 extern void blk_put_request(struct request *); 772 extern void __blk_put_request(struct request_queue *, struct request *); 773 extern struct request *blk_get_request(struct request_queue *, int, gfp_t); 774 extern struct request *blk_make_request(struct request_queue *, struct bio *, 775 gfp_t); 776 extern void blk_requeue_request(struct request_queue *, struct request *); 777 extern void blk_add_request_payload(struct request *rq, struct page *page, 778 unsigned int len); 779 extern int blk_rq_check_limits(struct request_queue *q, struct request *rq); 780 extern int blk_lld_busy(struct request_queue *q); 781 extern int blk_rq_prep_clone(struct request *rq, struct request *rq_src, 782 struct bio_set *bs, gfp_t gfp_mask, 783 int (*bio_ctr)(struct bio *, struct bio *, void *), 784 void *data); 785 extern void blk_rq_unprep_clone(struct request *rq); 786 extern int blk_insert_cloned_request(struct request_queue *q, 787 struct request *rq); 788 extern void blk_delay_queue(struct request_queue *, unsigned long); 789 extern void blk_recount_segments(struct request_queue *, struct bio *); 790 extern int scsi_verify_blk_ioctl(struct block_device *, unsigned int); 791 extern int scsi_cmd_blk_ioctl(struct block_device *, fmode_t, 792 unsigned int, void __user *); 793 extern int scsi_cmd_ioctl(struct request_queue *, struct gendisk *, fmode_t, 794 unsigned int, void __user *); 795 extern int sg_scsi_ioctl(struct request_queue *, struct gendisk *, fmode_t, 796 struct scsi_ioctl_command __user *); 797 798 extern void blk_queue_bio(struct request_queue *q, struct bio *bio); 799 800 /* 801 * A queue has just exitted congestion. Note this in the global counter of 802 * congested queues, and wake up anyone who was waiting for requests to be 803 * put back. 804 */ 805 static inline void blk_clear_queue_congested(struct request_queue *q, int sync) 806 { 807 clear_bdi_congested(&q->backing_dev_info, sync); 808 } 809 810 /* 811 * A queue has just entered congestion. Flag that in the queue's VM-visible 812 * state flags and increment the global gounter of congested queues. 813 */ 814 static inline void blk_set_queue_congested(struct request_queue *q, int sync) 815 { 816 set_bdi_congested(&q->backing_dev_info, sync); 817 } 818 819 extern void blk_start_queue(struct request_queue *q); 820 extern void blk_stop_queue(struct request_queue *q); 821 extern void blk_sync_queue(struct request_queue *q); 822 extern void __blk_stop_queue(struct request_queue *q); 823 extern void __blk_run_queue(struct request_queue *q); 824 extern void blk_run_queue(struct request_queue *); 825 extern void blk_run_queue_async(struct request_queue *q); 826 extern int blk_rq_map_user(struct request_queue *, struct request *, 827 struct rq_map_data *, void __user *, unsigned long, 828 gfp_t); 829 extern int blk_rq_unmap_user(struct bio *); 830 extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, unsigned int, gfp_t); 831 extern int blk_rq_map_user_iov(struct request_queue *, struct request *, 832 struct rq_map_data *, struct sg_iovec *, int, 833 unsigned int, gfp_t); 834 extern int blk_execute_rq(struct request_queue *, struct gendisk *, 835 struct request *, int); 836 extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *, 837 struct request *, int, rq_end_io_fn *); 838 839 static inline struct request_queue *bdev_get_queue(struct block_device *bdev) 840 { 841 return bdev->bd_disk->queue; 842 } 843 844 /* 845 * blk_rq_pos() : the current sector 846 * blk_rq_bytes() : bytes left in the entire request 847 * blk_rq_cur_bytes() : bytes left in the current segment 848 * blk_rq_err_bytes() : bytes left till the next error boundary 849 * blk_rq_sectors() : sectors left in the entire request 850 * blk_rq_cur_sectors() : sectors left in the current segment 851 */ 852 static inline sector_t blk_rq_pos(const struct request *rq) 853 { 854 return rq->__sector; 855 } 856 857 static inline unsigned int blk_rq_bytes(const struct request *rq) 858 { 859 return rq->__data_len; 860 } 861 862 static inline int blk_rq_cur_bytes(const struct request *rq) 863 { 864 return rq->bio ? bio_cur_bytes(rq->bio) : 0; 865 } 866 867 extern unsigned int blk_rq_err_bytes(const struct request *rq); 868 869 static inline unsigned int blk_rq_sectors(const struct request *rq) 870 { 871 return blk_rq_bytes(rq) >> 9; 872 } 873 874 static inline unsigned int blk_rq_cur_sectors(const struct request *rq) 875 { 876 return blk_rq_cur_bytes(rq) >> 9; 877 } 878 879 static inline unsigned int blk_queue_get_max_sectors(struct request_queue *q, 880 unsigned int cmd_flags) 881 { 882 if (unlikely(cmd_flags & REQ_DISCARD)) 883 return min(q->limits.max_discard_sectors, UINT_MAX >> 9); 884 885 if (unlikely(cmd_flags & REQ_WRITE_SAME)) 886 return q->limits.max_write_same_sectors; 887 888 return q->limits.max_sectors; 889 } 890 891 static inline unsigned int blk_rq_get_max_sectors(struct request *rq) 892 { 893 struct request_queue *q = rq->q; 894 895 if (unlikely(rq->cmd_type == REQ_TYPE_BLOCK_PC)) 896 return q->limits.max_hw_sectors; 897 898 return blk_queue_get_max_sectors(q, rq->cmd_flags); 899 } 900 901 static inline unsigned int blk_rq_count_bios(struct request *rq) 902 { 903 unsigned int nr_bios = 0; 904 struct bio *bio; 905 906 __rq_for_each_bio(bio, rq) 907 nr_bios++; 908 909 return nr_bios; 910 } 911 912 /* 913 * Request issue related functions. 914 */ 915 extern struct request *blk_peek_request(struct request_queue *q); 916 extern void blk_start_request(struct request *rq); 917 extern struct request *blk_fetch_request(struct request_queue *q); 918 919 /* 920 * Request completion related functions. 921 * 922 * blk_update_request() completes given number of bytes and updates 923 * the request without completing it. 924 * 925 * blk_end_request() and friends. __blk_end_request() must be called 926 * with the request queue spinlock acquired. 927 * 928 * Several drivers define their own end_request and call 929 * blk_end_request() for parts of the original function. 930 * This prevents code duplication in drivers. 931 */ 932 extern bool blk_update_request(struct request *rq, int error, 933 unsigned int nr_bytes); 934 extern bool blk_end_request(struct request *rq, int error, 935 unsigned int nr_bytes); 936 extern void blk_end_request_all(struct request *rq, int error); 937 extern bool blk_end_request_cur(struct request *rq, int error); 938 extern bool blk_end_request_err(struct request *rq, int error); 939 extern bool __blk_end_request(struct request *rq, int error, 940 unsigned int nr_bytes); 941 extern void __blk_end_request_all(struct request *rq, int error); 942 extern bool __blk_end_request_cur(struct request *rq, int error); 943 extern bool __blk_end_request_err(struct request *rq, int error); 944 945 extern void blk_complete_request(struct request *); 946 extern void __blk_complete_request(struct request *); 947 extern void blk_abort_request(struct request *); 948 extern void blk_unprep_request(struct request *); 949 950 /* 951 * Access functions for manipulating queue properties 952 */ 953 extern struct request_queue *blk_init_queue_node(request_fn_proc *rfn, 954 spinlock_t *lock, int node_id); 955 extern struct request_queue *blk_init_queue(request_fn_proc *, spinlock_t *); 956 extern struct request_queue *blk_init_allocated_queue(struct request_queue *, 957 request_fn_proc *, spinlock_t *); 958 extern void blk_cleanup_queue(struct request_queue *); 959 extern void blk_queue_make_request(struct request_queue *, make_request_fn *); 960 extern void blk_queue_bounce_limit(struct request_queue *, u64); 961 extern void blk_limits_max_hw_sectors(struct queue_limits *, unsigned int); 962 extern void blk_queue_max_hw_sectors(struct request_queue *, unsigned int); 963 extern void blk_queue_max_segments(struct request_queue *, unsigned short); 964 extern void blk_queue_max_segment_size(struct request_queue *, unsigned int); 965 extern void blk_queue_max_discard_sectors(struct request_queue *q, 966 unsigned int max_discard_sectors); 967 extern void blk_queue_max_write_same_sectors(struct request_queue *q, 968 unsigned int max_write_same_sectors); 969 extern void blk_queue_logical_block_size(struct request_queue *, unsigned short); 970 extern void blk_queue_physical_block_size(struct request_queue *, unsigned int); 971 extern void blk_queue_alignment_offset(struct request_queue *q, 972 unsigned int alignment); 973 extern void blk_limits_io_min(struct queue_limits *limits, unsigned int min); 974 extern void blk_queue_io_min(struct request_queue *q, unsigned int min); 975 extern void blk_limits_io_opt(struct queue_limits *limits, unsigned int opt); 976 extern void blk_queue_io_opt(struct request_queue *q, unsigned int opt); 977 extern void blk_set_default_limits(struct queue_limits *lim); 978 extern void blk_set_stacking_limits(struct queue_limits *lim); 979 extern int blk_stack_limits(struct queue_limits *t, struct queue_limits *b, 980 sector_t offset); 981 extern int bdev_stack_limits(struct queue_limits *t, struct block_device *bdev, 982 sector_t offset); 983 extern void disk_stack_limits(struct gendisk *disk, struct block_device *bdev, 984 sector_t offset); 985 extern void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b); 986 extern void blk_queue_dma_pad(struct request_queue *, unsigned int); 987 extern void blk_queue_update_dma_pad(struct request_queue *, unsigned int); 988 extern int blk_queue_dma_drain(struct request_queue *q, 989 dma_drain_needed_fn *dma_drain_needed, 990 void *buf, unsigned int size); 991 extern void blk_queue_lld_busy(struct request_queue *q, lld_busy_fn *fn); 992 extern void blk_queue_segment_boundary(struct request_queue *, unsigned long); 993 extern void blk_queue_prep_rq(struct request_queue *, prep_rq_fn *pfn); 994 extern void blk_queue_unprep_rq(struct request_queue *, unprep_rq_fn *ufn); 995 extern void blk_queue_merge_bvec(struct request_queue *, merge_bvec_fn *); 996 extern void blk_queue_dma_alignment(struct request_queue *, int); 997 extern void blk_queue_update_dma_alignment(struct request_queue *, int); 998 extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *); 999 extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *); 1000 extern void blk_queue_rq_timeout(struct request_queue *, unsigned int); 1001 extern void blk_queue_flush(struct request_queue *q, unsigned int flush); 1002 extern void blk_queue_flush_queueable(struct request_queue *q, bool queueable); 1003 extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev); 1004 1005 extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *); 1006 extern int blk_bio_map_sg(struct request_queue *q, struct bio *bio, 1007 struct scatterlist *sglist); 1008 extern void blk_dump_rq_flags(struct request *, char *); 1009 extern long nr_blockdev_pages(void); 1010 1011 bool __must_check blk_get_queue(struct request_queue *); 1012 struct request_queue *blk_alloc_queue(gfp_t); 1013 struct request_queue *blk_alloc_queue_node(gfp_t, int); 1014 extern void blk_put_queue(struct request_queue *); 1015 1016 /* 1017 * block layer runtime pm functions 1018 */ 1019 #ifdef CONFIG_PM_RUNTIME 1020 extern void blk_pm_runtime_init(struct request_queue *q, struct device *dev); 1021 extern int blk_pre_runtime_suspend(struct request_queue *q); 1022 extern void blk_post_runtime_suspend(struct request_queue *q, int err); 1023 extern void blk_pre_runtime_resume(struct request_queue *q); 1024 extern void blk_post_runtime_resume(struct request_queue *q, int err); 1025 #else 1026 static inline void blk_pm_runtime_init(struct request_queue *q, 1027 struct device *dev) {} 1028 static inline int blk_pre_runtime_suspend(struct request_queue *q) 1029 { 1030 return -ENOSYS; 1031 } 1032 static inline void blk_post_runtime_suspend(struct request_queue *q, int err) {} 1033 static inline void blk_pre_runtime_resume(struct request_queue *q) {} 1034 static inline void blk_post_runtime_resume(struct request_queue *q, int err) {} 1035 #endif 1036 1037 /* 1038 * blk_plug permits building a queue of related requests by holding the I/O 1039 * fragments for a short period. This allows merging of sequential requests 1040 * into single larger request. As the requests are moved from a per-task list to 1041 * the device's request_queue in a batch, this results in improved scalability 1042 * as the lock contention for request_queue lock is reduced. 1043 * 1044 * It is ok not to disable preemption when adding the request to the plug list 1045 * or when attempting a merge, because blk_schedule_flush_list() will only flush 1046 * the plug list when the task sleeps by itself. For details, please see 1047 * schedule() where blk_schedule_flush_plug() is called. 1048 */ 1049 struct blk_plug { 1050 unsigned long magic; /* detect uninitialized use-cases */ 1051 struct list_head list; /* requests */ 1052 struct list_head mq_list; /* blk-mq requests */ 1053 struct list_head cb_list; /* md requires an unplug callback */ 1054 }; 1055 #define BLK_MAX_REQUEST_COUNT 16 1056 1057 struct blk_plug_cb; 1058 typedef void (*blk_plug_cb_fn)(struct blk_plug_cb *, bool); 1059 struct blk_plug_cb { 1060 struct list_head list; 1061 blk_plug_cb_fn callback; 1062 void *data; 1063 }; 1064 extern struct blk_plug_cb *blk_check_plugged(blk_plug_cb_fn unplug, 1065 void *data, int size); 1066 extern void blk_start_plug(struct blk_plug *); 1067 extern void blk_finish_plug(struct blk_plug *); 1068 extern void blk_flush_plug_list(struct blk_plug *, bool); 1069 1070 static inline void blk_flush_plug(struct task_struct *tsk) 1071 { 1072 struct blk_plug *plug = tsk->plug; 1073 1074 if (plug) 1075 blk_flush_plug_list(plug, false); 1076 } 1077 1078 static inline void blk_schedule_flush_plug(struct task_struct *tsk) 1079 { 1080 struct blk_plug *plug = tsk->plug; 1081 1082 if (plug) 1083 blk_flush_plug_list(plug, true); 1084 } 1085 1086 static inline bool blk_needs_flush_plug(struct task_struct *tsk) 1087 { 1088 struct blk_plug *plug = tsk->plug; 1089 1090 return plug && 1091 (!list_empty(&plug->list) || 1092 !list_empty(&plug->mq_list) || 1093 !list_empty(&plug->cb_list)); 1094 } 1095 1096 /* 1097 * tag stuff 1098 */ 1099 #define blk_rq_tagged(rq) ((rq)->cmd_flags & REQ_QUEUED) 1100 extern int blk_queue_start_tag(struct request_queue *, struct request *); 1101 extern struct request *blk_queue_find_tag(struct request_queue *, int); 1102 extern void blk_queue_end_tag(struct request_queue *, struct request *); 1103 extern int blk_queue_init_tags(struct request_queue *, int, struct blk_queue_tag *); 1104 extern void blk_queue_free_tags(struct request_queue *); 1105 extern int blk_queue_resize_tags(struct request_queue *, int); 1106 extern void blk_queue_invalidate_tags(struct request_queue *); 1107 extern struct blk_queue_tag *blk_init_tags(int); 1108 extern void blk_free_tags(struct blk_queue_tag *); 1109 1110 static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt, 1111 int tag) 1112 { 1113 if (unlikely(bqt == NULL || tag >= bqt->real_max_depth)) 1114 return NULL; 1115 return bqt->tag_index[tag]; 1116 } 1117 1118 #define BLKDEV_DISCARD_SECURE 0x01 /* secure discard */ 1119 1120 extern int blkdev_issue_flush(struct block_device *, gfp_t, sector_t *); 1121 extern int blkdev_issue_discard(struct block_device *bdev, sector_t sector, 1122 sector_t nr_sects, gfp_t gfp_mask, unsigned long flags); 1123 extern int blkdev_issue_write_same(struct block_device *bdev, sector_t sector, 1124 sector_t nr_sects, gfp_t gfp_mask, struct page *page); 1125 extern int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector, 1126 sector_t nr_sects, gfp_t gfp_mask); 1127 static inline int sb_issue_discard(struct super_block *sb, sector_t block, 1128 sector_t nr_blocks, gfp_t gfp_mask, unsigned long flags) 1129 { 1130 return blkdev_issue_discard(sb->s_bdev, block << (sb->s_blocksize_bits - 9), 1131 nr_blocks << (sb->s_blocksize_bits - 9), 1132 gfp_mask, flags); 1133 } 1134 static inline int sb_issue_zeroout(struct super_block *sb, sector_t block, 1135 sector_t nr_blocks, gfp_t gfp_mask) 1136 { 1137 return blkdev_issue_zeroout(sb->s_bdev, 1138 block << (sb->s_blocksize_bits - 9), 1139 nr_blocks << (sb->s_blocksize_bits - 9), 1140 gfp_mask); 1141 } 1142 1143 extern int blk_verify_command(unsigned char *cmd, fmode_t has_write_perm); 1144 1145 enum blk_default_limits { 1146 BLK_MAX_SEGMENTS = 128, 1147 BLK_SAFE_MAX_SECTORS = 255, 1148 BLK_DEF_MAX_SECTORS = 1024, 1149 BLK_MAX_SEGMENT_SIZE = 65536, 1150 BLK_SEG_BOUNDARY_MASK = 0xFFFFFFFFUL, 1151 }; 1152 1153 #define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist) 1154 1155 static inline unsigned long queue_bounce_pfn(struct request_queue *q) 1156 { 1157 return q->limits.bounce_pfn; 1158 } 1159 1160 static inline unsigned long queue_segment_boundary(struct request_queue *q) 1161 { 1162 return q->limits.seg_boundary_mask; 1163 } 1164 1165 static inline unsigned int queue_max_sectors(struct request_queue *q) 1166 { 1167 return q->limits.max_sectors; 1168 } 1169 1170 static inline unsigned int queue_max_hw_sectors(struct request_queue *q) 1171 { 1172 return q->limits.max_hw_sectors; 1173 } 1174 1175 static inline unsigned short queue_max_segments(struct request_queue *q) 1176 { 1177 return q->limits.max_segments; 1178 } 1179 1180 static inline unsigned int queue_max_segment_size(struct request_queue *q) 1181 { 1182 return q->limits.max_segment_size; 1183 } 1184 1185 static inline unsigned short queue_logical_block_size(struct request_queue *q) 1186 { 1187 int retval = 512; 1188 1189 if (q && q->limits.logical_block_size) 1190 retval = q->limits.logical_block_size; 1191 1192 return retval; 1193 } 1194 1195 static inline unsigned short bdev_logical_block_size(struct block_device *bdev) 1196 { 1197 return queue_logical_block_size(bdev_get_queue(bdev)); 1198 } 1199 1200 static inline unsigned int queue_physical_block_size(struct request_queue *q) 1201 { 1202 return q->limits.physical_block_size; 1203 } 1204 1205 static inline unsigned int bdev_physical_block_size(struct block_device *bdev) 1206 { 1207 return queue_physical_block_size(bdev_get_queue(bdev)); 1208 } 1209 1210 static inline unsigned int queue_io_min(struct request_queue *q) 1211 { 1212 return q->limits.io_min; 1213 } 1214 1215 static inline int bdev_io_min(struct block_device *bdev) 1216 { 1217 return queue_io_min(bdev_get_queue(bdev)); 1218 } 1219 1220 static inline unsigned int queue_io_opt(struct request_queue *q) 1221 { 1222 return q->limits.io_opt; 1223 } 1224 1225 static inline int bdev_io_opt(struct block_device *bdev) 1226 { 1227 return queue_io_opt(bdev_get_queue(bdev)); 1228 } 1229 1230 static inline int queue_alignment_offset(struct request_queue *q) 1231 { 1232 if (q->limits.misaligned) 1233 return -1; 1234 1235 return q->limits.alignment_offset; 1236 } 1237 1238 static inline int queue_limit_alignment_offset(struct queue_limits *lim, sector_t sector) 1239 { 1240 unsigned int granularity = max(lim->physical_block_size, lim->io_min); 1241 unsigned int alignment = (sector << 9) & (granularity - 1); 1242 1243 return (granularity + lim->alignment_offset - alignment) 1244 & (granularity - 1); 1245 } 1246 1247 static inline int bdev_alignment_offset(struct block_device *bdev) 1248 { 1249 struct request_queue *q = bdev_get_queue(bdev); 1250 1251 if (q->limits.misaligned) 1252 return -1; 1253 1254 if (bdev != bdev->bd_contains) 1255 return bdev->bd_part->alignment_offset; 1256 1257 return q->limits.alignment_offset; 1258 } 1259 1260 static inline int queue_discard_alignment(struct request_queue *q) 1261 { 1262 if (q->limits.discard_misaligned) 1263 return -1; 1264 1265 return q->limits.discard_alignment; 1266 } 1267 1268 static inline int queue_limit_discard_alignment(struct queue_limits *lim, sector_t sector) 1269 { 1270 unsigned int alignment, granularity, offset; 1271 1272 if (!lim->max_discard_sectors) 1273 return 0; 1274 1275 /* Why are these in bytes, not sectors? */ 1276 alignment = lim->discard_alignment >> 9; 1277 granularity = lim->discard_granularity >> 9; 1278 if (!granularity) 1279 return 0; 1280 1281 /* Offset of the partition start in 'granularity' sectors */ 1282 offset = sector_div(sector, granularity); 1283 1284 /* And why do we do this modulus *again* in blkdev_issue_discard()? */ 1285 offset = (granularity + alignment - offset) % granularity; 1286 1287 /* Turn it back into bytes, gaah */ 1288 return offset << 9; 1289 } 1290 1291 static inline int bdev_discard_alignment(struct block_device *bdev) 1292 { 1293 struct request_queue *q = bdev_get_queue(bdev); 1294 1295 if (bdev != bdev->bd_contains) 1296 return bdev->bd_part->discard_alignment; 1297 1298 return q->limits.discard_alignment; 1299 } 1300 1301 static inline unsigned int queue_discard_zeroes_data(struct request_queue *q) 1302 { 1303 if (q->limits.max_discard_sectors && q->limits.discard_zeroes_data == 1) 1304 return 1; 1305 1306 return 0; 1307 } 1308 1309 static inline unsigned int bdev_discard_zeroes_data(struct block_device *bdev) 1310 { 1311 return queue_discard_zeroes_data(bdev_get_queue(bdev)); 1312 } 1313 1314 static inline unsigned int bdev_write_same(struct block_device *bdev) 1315 { 1316 struct request_queue *q = bdev_get_queue(bdev); 1317 1318 if (q) 1319 return q->limits.max_write_same_sectors; 1320 1321 return 0; 1322 } 1323 1324 static inline int queue_dma_alignment(struct request_queue *q) 1325 { 1326 return q ? q->dma_alignment : 511; 1327 } 1328 1329 static inline int blk_rq_aligned(struct request_queue *q, unsigned long addr, 1330 unsigned int len) 1331 { 1332 unsigned int alignment = queue_dma_alignment(q) | q->dma_pad_mask; 1333 return !(addr & alignment) && !(len & alignment); 1334 } 1335 1336 /* assumes size > 256 */ 1337 static inline unsigned int blksize_bits(unsigned int size) 1338 { 1339 unsigned int bits = 8; 1340 do { 1341 bits++; 1342 size >>= 1; 1343 } while (size > 256); 1344 return bits; 1345 } 1346 1347 static inline unsigned int block_size(struct block_device *bdev) 1348 { 1349 return bdev->bd_block_size; 1350 } 1351 1352 static inline bool queue_flush_queueable(struct request_queue *q) 1353 { 1354 return !q->flush_not_queueable; 1355 } 1356 1357 typedef struct {struct page *v;} Sector; 1358 1359 unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *); 1360 1361 static inline void put_dev_sector(Sector p) 1362 { 1363 page_cache_release(p.v); 1364 } 1365 1366 struct work_struct; 1367 int kblockd_schedule_work(struct request_queue *q, struct work_struct *work); 1368 int kblockd_schedule_delayed_work(struct request_queue *q, struct delayed_work *dwork, unsigned long delay); 1369 1370 #ifdef CONFIG_BLK_CGROUP 1371 /* 1372 * This should not be using sched_clock(). A real patch is in progress 1373 * to fix this up, until that is in place we need to disable preemption 1374 * around sched_clock() in this function and set_io_start_time_ns(). 1375 */ 1376 static inline void set_start_time_ns(struct request *req) 1377 { 1378 preempt_disable(); 1379 req->start_time_ns = sched_clock(); 1380 preempt_enable(); 1381 } 1382 1383 static inline void set_io_start_time_ns(struct request *req) 1384 { 1385 preempt_disable(); 1386 req->io_start_time_ns = sched_clock(); 1387 preempt_enable(); 1388 } 1389 1390 static inline uint64_t rq_start_time_ns(struct request *req) 1391 { 1392 return req->start_time_ns; 1393 } 1394 1395 static inline uint64_t rq_io_start_time_ns(struct request *req) 1396 { 1397 return req->io_start_time_ns; 1398 } 1399 #else 1400 static inline void set_start_time_ns(struct request *req) {} 1401 static inline void set_io_start_time_ns(struct request *req) {} 1402 static inline uint64_t rq_start_time_ns(struct request *req) 1403 { 1404 return 0; 1405 } 1406 static inline uint64_t rq_io_start_time_ns(struct request *req) 1407 { 1408 return 0; 1409 } 1410 #endif 1411 1412 #define MODULE_ALIAS_BLOCKDEV(major,minor) \ 1413 MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor)) 1414 #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \ 1415 MODULE_ALIAS("block-major-" __stringify(major) "-*") 1416 1417 #if defined(CONFIG_BLK_DEV_INTEGRITY) 1418 1419 #define INTEGRITY_FLAG_READ 2 /* verify data integrity on read */ 1420 #define INTEGRITY_FLAG_WRITE 4 /* generate data integrity on write */ 1421 1422 struct blk_integrity_exchg { 1423 void *prot_buf; 1424 void *data_buf; 1425 sector_t sector; 1426 unsigned int data_size; 1427 unsigned short sector_size; 1428 const char *disk_name; 1429 }; 1430 1431 typedef void (integrity_gen_fn) (struct blk_integrity_exchg *); 1432 typedef int (integrity_vrfy_fn) (struct blk_integrity_exchg *); 1433 typedef void (integrity_set_tag_fn) (void *, void *, unsigned int); 1434 typedef void (integrity_get_tag_fn) (void *, void *, unsigned int); 1435 1436 struct blk_integrity { 1437 integrity_gen_fn *generate_fn; 1438 integrity_vrfy_fn *verify_fn; 1439 integrity_set_tag_fn *set_tag_fn; 1440 integrity_get_tag_fn *get_tag_fn; 1441 1442 unsigned short flags; 1443 unsigned short tuple_size; 1444 unsigned short sector_size; 1445 unsigned short tag_size; 1446 1447 const char *name; 1448 1449 struct kobject kobj; 1450 }; 1451 1452 extern bool blk_integrity_is_initialized(struct gendisk *); 1453 extern int blk_integrity_register(struct gendisk *, struct blk_integrity *); 1454 extern void blk_integrity_unregister(struct gendisk *); 1455 extern int blk_integrity_compare(struct gendisk *, struct gendisk *); 1456 extern int blk_rq_map_integrity_sg(struct request_queue *, struct bio *, 1457 struct scatterlist *); 1458 extern int blk_rq_count_integrity_sg(struct request_queue *, struct bio *); 1459 extern int blk_integrity_merge_rq(struct request_queue *, struct request *, 1460 struct request *); 1461 extern int blk_integrity_merge_bio(struct request_queue *, struct request *, 1462 struct bio *); 1463 1464 static inline 1465 struct blk_integrity *bdev_get_integrity(struct block_device *bdev) 1466 { 1467 return bdev->bd_disk->integrity; 1468 } 1469 1470 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk) 1471 { 1472 return disk->integrity; 1473 } 1474 1475 static inline int blk_integrity_rq(struct request *rq) 1476 { 1477 if (rq->bio == NULL) 1478 return 0; 1479 1480 return bio_integrity(rq->bio); 1481 } 1482 1483 static inline void blk_queue_max_integrity_segments(struct request_queue *q, 1484 unsigned int segs) 1485 { 1486 q->limits.max_integrity_segments = segs; 1487 } 1488 1489 static inline unsigned short 1490 queue_max_integrity_segments(struct request_queue *q) 1491 { 1492 return q->limits.max_integrity_segments; 1493 } 1494 1495 #else /* CONFIG_BLK_DEV_INTEGRITY */ 1496 1497 struct bio; 1498 struct block_device; 1499 struct gendisk; 1500 struct blk_integrity; 1501 1502 static inline int blk_integrity_rq(struct request *rq) 1503 { 1504 return 0; 1505 } 1506 static inline int blk_rq_count_integrity_sg(struct request_queue *q, 1507 struct bio *b) 1508 { 1509 return 0; 1510 } 1511 static inline int blk_rq_map_integrity_sg(struct request_queue *q, 1512 struct bio *b, 1513 struct scatterlist *s) 1514 { 1515 return 0; 1516 } 1517 static inline struct blk_integrity *bdev_get_integrity(struct block_device *b) 1518 { 1519 return 0; 1520 } 1521 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk) 1522 { 1523 return NULL; 1524 } 1525 static inline int blk_integrity_compare(struct gendisk *a, struct gendisk *b) 1526 { 1527 return 0; 1528 } 1529 static inline int blk_integrity_register(struct gendisk *d, 1530 struct blk_integrity *b) 1531 { 1532 return 0; 1533 } 1534 static inline void blk_integrity_unregister(struct gendisk *d) 1535 { 1536 } 1537 static inline void blk_queue_max_integrity_segments(struct request_queue *q, 1538 unsigned int segs) 1539 { 1540 } 1541 static inline unsigned short queue_max_integrity_segments(struct request_queue *q) 1542 { 1543 return 0; 1544 } 1545 static inline int blk_integrity_merge_rq(struct request_queue *rq, 1546 struct request *r1, 1547 struct request *r2) 1548 { 1549 return 0; 1550 } 1551 static inline int blk_integrity_merge_bio(struct request_queue *rq, 1552 struct request *r, 1553 struct bio *b) 1554 { 1555 return 0; 1556 } 1557 static inline bool blk_integrity_is_initialized(struct gendisk *g) 1558 { 1559 return 0; 1560 } 1561 1562 #endif /* CONFIG_BLK_DEV_INTEGRITY */ 1563 1564 struct block_device_operations { 1565 int (*open) (struct block_device *, fmode_t); 1566 void (*release) (struct gendisk *, fmode_t); 1567 int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long); 1568 int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long); 1569 int (*direct_access) (struct block_device *, sector_t, 1570 void **, unsigned long *); 1571 unsigned int (*check_events) (struct gendisk *disk, 1572 unsigned int clearing); 1573 /* ->media_changed() is DEPRECATED, use ->check_events() instead */ 1574 int (*media_changed) (struct gendisk *); 1575 void (*unlock_native_capacity) (struct gendisk *); 1576 int (*revalidate_disk) (struct gendisk *); 1577 int (*getgeo)(struct block_device *, struct hd_geometry *); 1578 /* this callback is with swap_lock and sometimes page table lock held */ 1579 void (*swap_slot_free_notify) (struct block_device *, unsigned long); 1580 struct module *owner; 1581 }; 1582 1583 extern int __blkdev_driver_ioctl(struct block_device *, fmode_t, unsigned int, 1584 unsigned long); 1585 #else /* CONFIG_BLOCK */ 1586 /* 1587 * stubs for when the block layer is configured out 1588 */ 1589 #define buffer_heads_over_limit 0 1590 1591 static inline long nr_blockdev_pages(void) 1592 { 1593 return 0; 1594 } 1595 1596 struct blk_plug { 1597 }; 1598 1599 static inline void blk_start_plug(struct blk_plug *plug) 1600 { 1601 } 1602 1603 static inline void blk_finish_plug(struct blk_plug *plug) 1604 { 1605 } 1606 1607 static inline void blk_flush_plug(struct task_struct *task) 1608 { 1609 } 1610 1611 static inline void blk_schedule_flush_plug(struct task_struct *task) 1612 { 1613 } 1614 1615 1616 static inline bool blk_needs_flush_plug(struct task_struct *tsk) 1617 { 1618 return false; 1619 } 1620 1621 #endif /* CONFIG_BLOCK */ 1622 1623 #endif 1624