1 #ifndef _LINUX_BLKDEV_H 2 #define _LINUX_BLKDEV_H 3 4 #include <linux/sched.h> 5 6 #ifdef CONFIG_BLOCK 7 8 #include <linux/major.h> 9 #include <linux/genhd.h> 10 #include <linux/list.h> 11 #include <linux/llist.h> 12 #include <linux/timer.h> 13 #include <linux/workqueue.h> 14 #include <linux/pagemap.h> 15 #include <linux/backing-dev.h> 16 #include <linux/wait.h> 17 #include <linux/mempool.h> 18 #include <linux/bio.h> 19 #include <linux/stringify.h> 20 #include <linux/gfp.h> 21 #include <linux/bsg.h> 22 #include <linux/smp.h> 23 #include <linux/rcupdate.h> 24 25 #include <asm/scatterlist.h> 26 27 struct module; 28 struct scsi_ioctl_command; 29 30 struct request_queue; 31 struct elevator_queue; 32 struct request_pm_state; 33 struct blk_trace; 34 struct request; 35 struct sg_io_hdr; 36 struct bsg_job; 37 struct blkcg_gq; 38 39 #define BLKDEV_MIN_RQ 4 40 #define BLKDEV_MAX_RQ 128 /* Default maximum */ 41 42 /* 43 * Maximum number of blkcg policies allowed to be registered concurrently. 44 * Defined here to simplify include dependency. 45 */ 46 #define BLKCG_MAX_POLS 2 47 48 struct request; 49 typedef void (rq_end_io_fn)(struct request *, int); 50 51 #define BLK_RL_SYNCFULL (1U << 0) 52 #define BLK_RL_ASYNCFULL (1U << 1) 53 54 struct request_list { 55 struct request_queue *q; /* the queue this rl belongs to */ 56 #ifdef CONFIG_BLK_CGROUP 57 struct blkcg_gq *blkg; /* blkg this request pool belongs to */ 58 #endif 59 /* 60 * count[], starved[], and wait[] are indexed by 61 * BLK_RW_SYNC/BLK_RW_ASYNC 62 */ 63 int count[2]; 64 int starved[2]; 65 mempool_t *rq_pool; 66 wait_queue_head_t wait[2]; 67 unsigned int flags; 68 }; 69 70 /* 71 * request command types 72 */ 73 enum rq_cmd_type_bits { 74 REQ_TYPE_FS = 1, /* fs request */ 75 REQ_TYPE_BLOCK_PC, /* scsi command */ 76 REQ_TYPE_SENSE, /* sense request */ 77 REQ_TYPE_PM_SUSPEND, /* suspend request */ 78 REQ_TYPE_PM_RESUME, /* resume request */ 79 REQ_TYPE_PM_SHUTDOWN, /* shutdown request */ 80 REQ_TYPE_SPECIAL, /* driver defined type */ 81 /* 82 * for ATA/ATAPI devices. this really doesn't belong here, ide should 83 * use REQ_TYPE_SPECIAL and use rq->cmd[0] with the range of driver 84 * private REQ_LB opcodes to differentiate what type of request this is 85 */ 86 REQ_TYPE_ATA_TASKFILE, 87 REQ_TYPE_ATA_PC, 88 }; 89 90 #define BLK_MAX_CDB 16 91 92 /* 93 * try to put the fields that are referenced together in the same cacheline. 94 * if you modify this structure, be sure to check block/blk-core.c:blk_rq_init() 95 * as well! 96 */ 97 struct request { 98 struct list_head queuelist; 99 union { 100 struct call_single_data csd; 101 struct work_struct mq_flush_work; 102 unsigned long fifo_time; 103 }; 104 105 struct request_queue *q; 106 struct blk_mq_ctx *mq_ctx; 107 108 u64 cmd_flags; 109 enum rq_cmd_type_bits cmd_type; 110 unsigned long atomic_flags; 111 112 int cpu; 113 114 /* the following two fields are internal, NEVER access directly */ 115 unsigned int __data_len; /* total data len */ 116 sector_t __sector; /* sector cursor */ 117 118 struct bio *bio; 119 struct bio *biotail; 120 121 /* 122 * The hash is used inside the scheduler, and killed once the 123 * request reaches the dispatch list. The ipi_list is only used 124 * to queue the request for softirq completion, which is long 125 * after the request has been unhashed (and even removed from 126 * the dispatch list). 127 */ 128 union { 129 struct hlist_node hash; /* merge hash */ 130 struct list_head ipi_list; 131 }; 132 133 /* 134 * The rb_node is only used inside the io scheduler, requests 135 * are pruned when moved to the dispatch queue. So let the 136 * completion_data share space with the rb_node. 137 */ 138 union { 139 struct rb_node rb_node; /* sort/lookup */ 140 void *completion_data; 141 }; 142 143 /* 144 * Three pointers are available for the IO schedulers, if they need 145 * more they have to dynamically allocate it. Flush requests are 146 * never put on the IO scheduler. So let the flush fields share 147 * space with the elevator data. 148 */ 149 union { 150 struct { 151 struct io_cq *icq; 152 void *priv[2]; 153 } elv; 154 155 struct { 156 unsigned int seq; 157 struct list_head list; 158 rq_end_io_fn *saved_end_io; 159 } flush; 160 }; 161 162 struct gendisk *rq_disk; 163 struct hd_struct *part; 164 unsigned long start_time; 165 #ifdef CONFIG_BLK_CGROUP 166 struct request_list *rl; /* rl this rq is alloced from */ 167 unsigned long long start_time_ns; 168 unsigned long long io_start_time_ns; /* when passed to hardware */ 169 #endif 170 /* Number of scatter-gather DMA addr+len pairs after 171 * physical address coalescing is performed. 172 */ 173 unsigned short nr_phys_segments; 174 #if defined(CONFIG_BLK_DEV_INTEGRITY) 175 unsigned short nr_integrity_segments; 176 #endif 177 178 unsigned short ioprio; 179 180 void *special; /* opaque pointer available for LLD use */ 181 char *buffer; /* kaddr of the current segment if available */ 182 183 int tag; 184 int errors; 185 186 /* 187 * when request is used as a packet command carrier 188 */ 189 unsigned char __cmd[BLK_MAX_CDB]; 190 unsigned char *cmd; 191 unsigned short cmd_len; 192 193 unsigned int extra_len; /* length of alignment and padding */ 194 unsigned int sense_len; 195 unsigned int resid_len; /* residual count */ 196 void *sense; 197 198 unsigned long deadline; 199 struct list_head timeout_list; 200 unsigned int timeout; 201 int retries; 202 203 /* 204 * completion callback. 205 */ 206 rq_end_io_fn *end_io; 207 void *end_io_data; 208 209 /* for bidi */ 210 struct request *next_rq; 211 }; 212 213 static inline unsigned short req_get_ioprio(struct request *req) 214 { 215 return req->ioprio; 216 } 217 218 /* 219 * State information carried for REQ_TYPE_PM_SUSPEND and REQ_TYPE_PM_RESUME 220 * requests. Some step values could eventually be made generic. 221 */ 222 struct request_pm_state 223 { 224 /* PM state machine step value, currently driver specific */ 225 int pm_step; 226 /* requested PM state value (S1, S2, S3, S4, ...) */ 227 u32 pm_state; 228 void* data; /* for driver use */ 229 }; 230 231 #include <linux/elevator.h> 232 233 struct blk_queue_ctx; 234 235 typedef void (request_fn_proc) (struct request_queue *q); 236 typedef void (make_request_fn) (struct request_queue *q, struct bio *bio); 237 typedef int (prep_rq_fn) (struct request_queue *, struct request *); 238 typedef void (unprep_rq_fn) (struct request_queue *, struct request *); 239 240 struct bio_vec; 241 struct bvec_merge_data { 242 struct block_device *bi_bdev; 243 sector_t bi_sector; 244 unsigned bi_size; 245 unsigned long bi_rw; 246 }; 247 typedef int (merge_bvec_fn) (struct request_queue *, struct bvec_merge_data *, 248 struct bio_vec *); 249 typedef void (softirq_done_fn)(struct request *); 250 typedef int (dma_drain_needed_fn)(struct request *); 251 typedef int (lld_busy_fn) (struct request_queue *q); 252 typedef int (bsg_job_fn) (struct bsg_job *); 253 254 enum blk_eh_timer_return { 255 BLK_EH_NOT_HANDLED, 256 BLK_EH_HANDLED, 257 BLK_EH_RESET_TIMER, 258 }; 259 260 typedef enum blk_eh_timer_return (rq_timed_out_fn)(struct request *); 261 262 enum blk_queue_state { 263 Queue_down, 264 Queue_up, 265 }; 266 267 struct blk_queue_tag { 268 struct request **tag_index; /* map of busy tags */ 269 unsigned long *tag_map; /* bit map of free/busy tags */ 270 int busy; /* current depth */ 271 int max_depth; /* what we will send to device */ 272 int real_max_depth; /* what the array can hold */ 273 atomic_t refcnt; /* map can be shared */ 274 }; 275 276 #define BLK_SCSI_MAX_CMDS (256) 277 #define BLK_SCSI_CMD_PER_LONG (BLK_SCSI_MAX_CMDS / (sizeof(long) * 8)) 278 279 struct queue_limits { 280 unsigned long bounce_pfn; 281 unsigned long seg_boundary_mask; 282 283 unsigned int max_hw_sectors; 284 unsigned int max_sectors; 285 unsigned int max_segment_size; 286 unsigned int physical_block_size; 287 unsigned int alignment_offset; 288 unsigned int io_min; 289 unsigned int io_opt; 290 unsigned int max_discard_sectors; 291 unsigned int max_write_same_sectors; 292 unsigned int discard_granularity; 293 unsigned int discard_alignment; 294 295 unsigned short logical_block_size; 296 unsigned short max_segments; 297 unsigned short max_integrity_segments; 298 299 unsigned char misaligned; 300 unsigned char discard_misaligned; 301 unsigned char cluster; 302 unsigned char discard_zeroes_data; 303 unsigned char raid_partial_stripes_expensive; 304 }; 305 306 struct request_queue { 307 /* 308 * Together with queue_head for cacheline sharing 309 */ 310 struct list_head queue_head; 311 struct request *last_merge; 312 struct elevator_queue *elevator; 313 int nr_rqs[2]; /* # allocated [a]sync rqs */ 314 int nr_rqs_elvpriv; /* # allocated rqs w/ elvpriv */ 315 316 /* 317 * If blkcg is not used, @q->root_rl serves all requests. If blkcg 318 * is used, root blkg allocates from @q->root_rl and all other 319 * blkgs from their own blkg->rl. Which one to use should be 320 * determined using bio_request_list(). 321 */ 322 struct request_list root_rl; 323 324 request_fn_proc *request_fn; 325 make_request_fn *make_request_fn; 326 prep_rq_fn *prep_rq_fn; 327 unprep_rq_fn *unprep_rq_fn; 328 merge_bvec_fn *merge_bvec_fn; 329 softirq_done_fn *softirq_done_fn; 330 rq_timed_out_fn *rq_timed_out_fn; 331 dma_drain_needed_fn *dma_drain_needed; 332 lld_busy_fn *lld_busy_fn; 333 334 struct blk_mq_ops *mq_ops; 335 336 unsigned int *mq_map; 337 338 /* sw queues */ 339 struct blk_mq_ctx *queue_ctx; 340 unsigned int nr_queues; 341 342 /* hw dispatch queues */ 343 struct blk_mq_hw_ctx **queue_hw_ctx; 344 unsigned int nr_hw_queues; 345 346 /* 347 * Dispatch queue sorting 348 */ 349 sector_t end_sector; 350 struct request *boundary_rq; 351 352 /* 353 * Delayed queue handling 354 */ 355 struct delayed_work delay_work; 356 357 struct backing_dev_info backing_dev_info; 358 359 /* 360 * The queue owner gets to use this for whatever they like. 361 * ll_rw_blk doesn't touch it. 362 */ 363 void *queuedata; 364 365 /* 366 * various queue flags, see QUEUE_* below 367 */ 368 unsigned long queue_flags; 369 370 /* 371 * ida allocated id for this queue. Used to index queues from 372 * ioctx. 373 */ 374 int id; 375 376 /* 377 * queue needs bounce pages for pages above this limit 378 */ 379 gfp_t bounce_gfp; 380 381 /* 382 * protects queue structures from reentrancy. ->__queue_lock should 383 * _never_ be used directly, it is queue private. always use 384 * ->queue_lock. 385 */ 386 spinlock_t __queue_lock; 387 spinlock_t *queue_lock; 388 389 /* 390 * queue kobject 391 */ 392 struct kobject kobj; 393 394 /* 395 * mq queue kobject 396 */ 397 struct kobject mq_kobj; 398 399 #ifdef CONFIG_PM_RUNTIME 400 struct device *dev; 401 int rpm_status; 402 unsigned int nr_pending; 403 #endif 404 405 /* 406 * queue settings 407 */ 408 unsigned long nr_requests; /* Max # of requests */ 409 unsigned int nr_congestion_on; 410 unsigned int nr_congestion_off; 411 unsigned int nr_batching; 412 413 unsigned int dma_drain_size; 414 void *dma_drain_buffer; 415 unsigned int dma_pad_mask; 416 unsigned int dma_alignment; 417 418 struct blk_queue_tag *queue_tags; 419 struct list_head tag_busy_list; 420 421 unsigned int nr_sorted; 422 unsigned int in_flight[2]; 423 /* 424 * Number of active block driver functions for which blk_drain_queue() 425 * must wait. Must be incremented around functions that unlock the 426 * queue_lock internally, e.g. scsi_request_fn(). 427 */ 428 unsigned int request_fn_active; 429 430 unsigned int rq_timeout; 431 struct timer_list timeout; 432 struct list_head timeout_list; 433 434 struct list_head icq_list; 435 #ifdef CONFIG_BLK_CGROUP 436 DECLARE_BITMAP (blkcg_pols, BLKCG_MAX_POLS); 437 struct blkcg_gq *root_blkg; 438 struct list_head blkg_list; 439 #endif 440 441 struct queue_limits limits; 442 443 /* 444 * sg stuff 445 */ 446 unsigned int sg_timeout; 447 unsigned int sg_reserved_size; 448 int node; 449 #ifdef CONFIG_BLK_DEV_IO_TRACE 450 struct blk_trace *blk_trace; 451 #endif 452 /* 453 * for flush operations 454 */ 455 unsigned int flush_flags; 456 unsigned int flush_not_queueable:1; 457 unsigned int flush_queue_delayed:1; 458 unsigned int flush_pending_idx:1; 459 unsigned int flush_running_idx:1; 460 unsigned long flush_pending_since; 461 struct list_head flush_queue[2]; 462 struct list_head flush_data_in_flight; 463 struct request *flush_rq; 464 spinlock_t mq_flush_lock; 465 466 struct mutex sysfs_lock; 467 468 int bypass_depth; 469 470 #if defined(CONFIG_BLK_DEV_BSG) 471 bsg_job_fn *bsg_job_fn; 472 int bsg_job_size; 473 struct bsg_class_device bsg_dev; 474 #endif 475 476 #ifdef CONFIG_BLK_DEV_THROTTLING 477 /* Throttle data */ 478 struct throtl_data *td; 479 #endif 480 struct rcu_head rcu_head; 481 wait_queue_head_t mq_freeze_wq; 482 struct percpu_counter mq_usage_counter; 483 struct list_head all_q_node; 484 }; 485 486 #define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */ 487 #define QUEUE_FLAG_STOPPED 2 /* queue is stopped */ 488 #define QUEUE_FLAG_SYNCFULL 3 /* read queue has been filled */ 489 #define QUEUE_FLAG_ASYNCFULL 4 /* write queue has been filled */ 490 #define QUEUE_FLAG_DYING 5 /* queue being torn down */ 491 #define QUEUE_FLAG_BYPASS 6 /* act as dumb FIFO queue */ 492 #define QUEUE_FLAG_BIDI 7 /* queue supports bidi requests */ 493 #define QUEUE_FLAG_NOMERGES 8 /* disable merge attempts */ 494 #define QUEUE_FLAG_SAME_COMP 9 /* complete on same CPU-group */ 495 #define QUEUE_FLAG_FAIL_IO 10 /* fake timeout */ 496 #define QUEUE_FLAG_STACKABLE 11 /* supports request stacking */ 497 #define QUEUE_FLAG_NONROT 12 /* non-rotational device (SSD) */ 498 #define QUEUE_FLAG_VIRT QUEUE_FLAG_NONROT /* paravirt device */ 499 #define QUEUE_FLAG_IO_STAT 13 /* do IO stats */ 500 #define QUEUE_FLAG_DISCARD 14 /* supports DISCARD */ 501 #define QUEUE_FLAG_NOXMERGES 15 /* No extended merges */ 502 #define QUEUE_FLAG_ADD_RANDOM 16 /* Contributes to random pool */ 503 #define QUEUE_FLAG_SECDISCARD 17 /* supports SECDISCARD */ 504 #define QUEUE_FLAG_SAME_FORCE 18 /* force complete on same CPU */ 505 #define QUEUE_FLAG_DEAD 19 /* queue tear-down finished */ 506 #define QUEUE_FLAG_INIT_DONE 20 /* queue is initialized */ 507 508 #define QUEUE_FLAG_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \ 509 (1 << QUEUE_FLAG_STACKABLE) | \ 510 (1 << QUEUE_FLAG_SAME_COMP) | \ 511 (1 << QUEUE_FLAG_ADD_RANDOM)) 512 513 #define QUEUE_FLAG_MQ_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \ 514 (1 << QUEUE_FLAG_SAME_COMP)) 515 516 static inline void queue_lockdep_assert_held(struct request_queue *q) 517 { 518 if (q->queue_lock) 519 lockdep_assert_held(q->queue_lock); 520 } 521 522 static inline void queue_flag_set_unlocked(unsigned int flag, 523 struct request_queue *q) 524 { 525 __set_bit(flag, &q->queue_flags); 526 } 527 528 static inline int queue_flag_test_and_clear(unsigned int flag, 529 struct request_queue *q) 530 { 531 queue_lockdep_assert_held(q); 532 533 if (test_bit(flag, &q->queue_flags)) { 534 __clear_bit(flag, &q->queue_flags); 535 return 1; 536 } 537 538 return 0; 539 } 540 541 static inline int queue_flag_test_and_set(unsigned int flag, 542 struct request_queue *q) 543 { 544 queue_lockdep_assert_held(q); 545 546 if (!test_bit(flag, &q->queue_flags)) { 547 __set_bit(flag, &q->queue_flags); 548 return 0; 549 } 550 551 return 1; 552 } 553 554 static inline void queue_flag_set(unsigned int flag, struct request_queue *q) 555 { 556 queue_lockdep_assert_held(q); 557 __set_bit(flag, &q->queue_flags); 558 } 559 560 static inline void queue_flag_clear_unlocked(unsigned int flag, 561 struct request_queue *q) 562 { 563 __clear_bit(flag, &q->queue_flags); 564 } 565 566 static inline int queue_in_flight(struct request_queue *q) 567 { 568 return q->in_flight[0] + q->in_flight[1]; 569 } 570 571 static inline void queue_flag_clear(unsigned int flag, struct request_queue *q) 572 { 573 queue_lockdep_assert_held(q); 574 __clear_bit(flag, &q->queue_flags); 575 } 576 577 #define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags) 578 #define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags) 579 #define blk_queue_dying(q) test_bit(QUEUE_FLAG_DYING, &(q)->queue_flags) 580 #define blk_queue_dead(q) test_bit(QUEUE_FLAG_DEAD, &(q)->queue_flags) 581 #define blk_queue_bypass(q) test_bit(QUEUE_FLAG_BYPASS, &(q)->queue_flags) 582 #define blk_queue_init_done(q) test_bit(QUEUE_FLAG_INIT_DONE, &(q)->queue_flags) 583 #define blk_queue_nomerges(q) test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags) 584 #define blk_queue_noxmerges(q) \ 585 test_bit(QUEUE_FLAG_NOXMERGES, &(q)->queue_flags) 586 #define blk_queue_nonrot(q) test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags) 587 #define blk_queue_io_stat(q) test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags) 588 #define blk_queue_add_random(q) test_bit(QUEUE_FLAG_ADD_RANDOM, &(q)->queue_flags) 589 #define blk_queue_stackable(q) \ 590 test_bit(QUEUE_FLAG_STACKABLE, &(q)->queue_flags) 591 #define blk_queue_discard(q) test_bit(QUEUE_FLAG_DISCARD, &(q)->queue_flags) 592 #define blk_queue_secdiscard(q) (blk_queue_discard(q) && \ 593 test_bit(QUEUE_FLAG_SECDISCARD, &(q)->queue_flags)) 594 595 #define blk_noretry_request(rq) \ 596 ((rq)->cmd_flags & (REQ_FAILFAST_DEV|REQ_FAILFAST_TRANSPORT| \ 597 REQ_FAILFAST_DRIVER)) 598 599 #define blk_account_rq(rq) \ 600 (((rq)->cmd_flags & REQ_STARTED) && \ 601 ((rq)->cmd_type == REQ_TYPE_FS)) 602 603 #define blk_pm_request(rq) \ 604 ((rq)->cmd_type == REQ_TYPE_PM_SUSPEND || \ 605 (rq)->cmd_type == REQ_TYPE_PM_RESUME) 606 607 #define blk_rq_cpu_valid(rq) ((rq)->cpu != -1) 608 #define blk_bidi_rq(rq) ((rq)->next_rq != NULL) 609 /* rq->queuelist of dequeued request must be list_empty() */ 610 #define blk_queued_rq(rq) (!list_empty(&(rq)->queuelist)) 611 612 #define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist) 613 614 #define rq_data_dir(rq) (((rq)->cmd_flags & 1) != 0) 615 616 static inline unsigned int blk_queue_cluster(struct request_queue *q) 617 { 618 return q->limits.cluster; 619 } 620 621 /* 622 * We regard a request as sync, if either a read or a sync write 623 */ 624 static inline bool rw_is_sync(unsigned int rw_flags) 625 { 626 return !(rw_flags & REQ_WRITE) || (rw_flags & REQ_SYNC); 627 } 628 629 static inline bool rq_is_sync(struct request *rq) 630 { 631 return rw_is_sync(rq->cmd_flags); 632 } 633 634 static inline bool blk_rl_full(struct request_list *rl, bool sync) 635 { 636 unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL; 637 638 return rl->flags & flag; 639 } 640 641 static inline void blk_set_rl_full(struct request_list *rl, bool sync) 642 { 643 unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL; 644 645 rl->flags |= flag; 646 } 647 648 static inline void blk_clear_rl_full(struct request_list *rl, bool sync) 649 { 650 unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL; 651 652 rl->flags &= ~flag; 653 } 654 655 static inline bool rq_mergeable(struct request *rq) 656 { 657 if (rq->cmd_type != REQ_TYPE_FS) 658 return false; 659 660 if (rq->cmd_flags & REQ_NOMERGE_FLAGS) 661 return false; 662 663 return true; 664 } 665 666 static inline bool blk_check_merge_flags(unsigned int flags1, 667 unsigned int flags2) 668 { 669 if ((flags1 & REQ_DISCARD) != (flags2 & REQ_DISCARD)) 670 return false; 671 672 if ((flags1 & REQ_SECURE) != (flags2 & REQ_SECURE)) 673 return false; 674 675 if ((flags1 & REQ_WRITE_SAME) != (flags2 & REQ_WRITE_SAME)) 676 return false; 677 678 return true; 679 } 680 681 static inline bool blk_write_same_mergeable(struct bio *a, struct bio *b) 682 { 683 if (bio_data(a) == bio_data(b)) 684 return true; 685 686 return false; 687 } 688 689 /* 690 * q->prep_rq_fn return values 691 */ 692 #define BLKPREP_OK 0 /* serve it */ 693 #define BLKPREP_KILL 1 /* fatal error, kill */ 694 #define BLKPREP_DEFER 2 /* leave on queue */ 695 696 extern unsigned long blk_max_low_pfn, blk_max_pfn; 697 698 /* 699 * standard bounce addresses: 700 * 701 * BLK_BOUNCE_HIGH : bounce all highmem pages 702 * BLK_BOUNCE_ANY : don't bounce anything 703 * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary 704 */ 705 706 #if BITS_PER_LONG == 32 707 #define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT) 708 #else 709 #define BLK_BOUNCE_HIGH -1ULL 710 #endif 711 #define BLK_BOUNCE_ANY (-1ULL) 712 #define BLK_BOUNCE_ISA (DMA_BIT_MASK(24)) 713 714 /* 715 * default timeout for SG_IO if none specified 716 */ 717 #define BLK_DEFAULT_SG_TIMEOUT (60 * HZ) 718 #define BLK_MIN_SG_TIMEOUT (7 * HZ) 719 720 #ifdef CONFIG_BOUNCE 721 extern int init_emergency_isa_pool(void); 722 extern void blk_queue_bounce(struct request_queue *q, struct bio **bio); 723 #else 724 static inline int init_emergency_isa_pool(void) 725 { 726 return 0; 727 } 728 static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio) 729 { 730 } 731 #endif /* CONFIG_MMU */ 732 733 struct rq_map_data { 734 struct page **pages; 735 int page_order; 736 int nr_entries; 737 unsigned long offset; 738 int null_mapped; 739 int from_user; 740 }; 741 742 struct req_iterator { 743 struct bvec_iter iter; 744 struct bio *bio; 745 }; 746 747 /* This should not be used directly - use rq_for_each_segment */ 748 #define for_each_bio(_bio) \ 749 for (; _bio; _bio = _bio->bi_next) 750 #define __rq_for_each_bio(_bio, rq) \ 751 if ((rq->bio)) \ 752 for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next) 753 754 #define rq_for_each_segment(bvl, _rq, _iter) \ 755 __rq_for_each_bio(_iter.bio, _rq) \ 756 bio_for_each_segment(bvl, _iter.bio, _iter.iter) 757 758 #define rq_iter_last(bvec, _iter) \ 759 (_iter.bio->bi_next == NULL && \ 760 bio_iter_last(bvec, _iter.iter)) 761 762 #ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 763 # error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform" 764 #endif 765 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 766 extern void rq_flush_dcache_pages(struct request *rq); 767 #else 768 static inline void rq_flush_dcache_pages(struct request *rq) 769 { 770 } 771 #endif 772 773 extern int blk_register_queue(struct gendisk *disk); 774 extern void blk_unregister_queue(struct gendisk *disk); 775 extern void generic_make_request(struct bio *bio); 776 extern void blk_rq_init(struct request_queue *q, struct request *rq); 777 extern void blk_put_request(struct request *); 778 extern void __blk_put_request(struct request_queue *, struct request *); 779 extern struct request *blk_get_request(struct request_queue *, int, gfp_t); 780 extern struct request *blk_make_request(struct request_queue *, struct bio *, 781 gfp_t); 782 extern void blk_requeue_request(struct request_queue *, struct request *); 783 extern void blk_add_request_payload(struct request *rq, struct page *page, 784 unsigned int len); 785 extern int blk_rq_check_limits(struct request_queue *q, struct request *rq); 786 extern int blk_lld_busy(struct request_queue *q); 787 extern int blk_rq_prep_clone(struct request *rq, struct request *rq_src, 788 struct bio_set *bs, gfp_t gfp_mask, 789 int (*bio_ctr)(struct bio *, struct bio *, void *), 790 void *data); 791 extern void blk_rq_unprep_clone(struct request *rq); 792 extern int blk_insert_cloned_request(struct request_queue *q, 793 struct request *rq); 794 extern void blk_delay_queue(struct request_queue *, unsigned long); 795 extern void blk_recount_segments(struct request_queue *, struct bio *); 796 extern int scsi_verify_blk_ioctl(struct block_device *, unsigned int); 797 extern int scsi_cmd_blk_ioctl(struct block_device *, fmode_t, 798 unsigned int, void __user *); 799 extern int scsi_cmd_ioctl(struct request_queue *, struct gendisk *, fmode_t, 800 unsigned int, void __user *); 801 extern int sg_scsi_ioctl(struct request_queue *, struct gendisk *, fmode_t, 802 struct scsi_ioctl_command __user *); 803 804 extern void blk_queue_bio(struct request_queue *q, struct bio *bio); 805 806 /* 807 * A queue has just exitted congestion. Note this in the global counter of 808 * congested queues, and wake up anyone who was waiting for requests to be 809 * put back. 810 */ 811 static inline void blk_clear_queue_congested(struct request_queue *q, int sync) 812 { 813 clear_bdi_congested(&q->backing_dev_info, sync); 814 } 815 816 /* 817 * A queue has just entered congestion. Flag that in the queue's VM-visible 818 * state flags and increment the global gounter of congested queues. 819 */ 820 static inline void blk_set_queue_congested(struct request_queue *q, int sync) 821 { 822 set_bdi_congested(&q->backing_dev_info, sync); 823 } 824 825 extern void blk_start_queue(struct request_queue *q); 826 extern void blk_stop_queue(struct request_queue *q); 827 extern void blk_sync_queue(struct request_queue *q); 828 extern void __blk_stop_queue(struct request_queue *q); 829 extern void __blk_run_queue(struct request_queue *q); 830 extern void blk_run_queue(struct request_queue *); 831 extern void blk_run_queue_async(struct request_queue *q); 832 extern int blk_rq_map_user(struct request_queue *, struct request *, 833 struct rq_map_data *, void __user *, unsigned long, 834 gfp_t); 835 extern int blk_rq_unmap_user(struct bio *); 836 extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, unsigned int, gfp_t); 837 extern int blk_rq_map_user_iov(struct request_queue *, struct request *, 838 struct rq_map_data *, const struct sg_iovec *, 839 int, unsigned int, gfp_t); 840 extern int blk_execute_rq(struct request_queue *, struct gendisk *, 841 struct request *, int); 842 extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *, 843 struct request *, int, rq_end_io_fn *); 844 845 static inline struct request_queue *bdev_get_queue(struct block_device *bdev) 846 { 847 return bdev->bd_disk->queue; 848 } 849 850 /* 851 * blk_rq_pos() : the current sector 852 * blk_rq_bytes() : bytes left in the entire request 853 * blk_rq_cur_bytes() : bytes left in the current segment 854 * blk_rq_err_bytes() : bytes left till the next error boundary 855 * blk_rq_sectors() : sectors left in the entire request 856 * blk_rq_cur_sectors() : sectors left in the current segment 857 */ 858 static inline sector_t blk_rq_pos(const struct request *rq) 859 { 860 return rq->__sector; 861 } 862 863 static inline unsigned int blk_rq_bytes(const struct request *rq) 864 { 865 return rq->__data_len; 866 } 867 868 static inline int blk_rq_cur_bytes(const struct request *rq) 869 { 870 return rq->bio ? bio_cur_bytes(rq->bio) : 0; 871 } 872 873 extern unsigned int blk_rq_err_bytes(const struct request *rq); 874 875 static inline unsigned int blk_rq_sectors(const struct request *rq) 876 { 877 return blk_rq_bytes(rq) >> 9; 878 } 879 880 static inline unsigned int blk_rq_cur_sectors(const struct request *rq) 881 { 882 return blk_rq_cur_bytes(rq) >> 9; 883 } 884 885 static inline unsigned int blk_queue_get_max_sectors(struct request_queue *q, 886 unsigned int cmd_flags) 887 { 888 if (unlikely(cmd_flags & REQ_DISCARD)) 889 return min(q->limits.max_discard_sectors, UINT_MAX >> 9); 890 891 if (unlikely(cmd_flags & REQ_WRITE_SAME)) 892 return q->limits.max_write_same_sectors; 893 894 return q->limits.max_sectors; 895 } 896 897 static inline unsigned int blk_rq_get_max_sectors(struct request *rq) 898 { 899 struct request_queue *q = rq->q; 900 901 if (unlikely(rq->cmd_type == REQ_TYPE_BLOCK_PC)) 902 return q->limits.max_hw_sectors; 903 904 return blk_queue_get_max_sectors(q, rq->cmd_flags); 905 } 906 907 static inline unsigned int blk_rq_count_bios(struct request *rq) 908 { 909 unsigned int nr_bios = 0; 910 struct bio *bio; 911 912 __rq_for_each_bio(bio, rq) 913 nr_bios++; 914 915 return nr_bios; 916 } 917 918 /* 919 * Request issue related functions. 920 */ 921 extern struct request *blk_peek_request(struct request_queue *q); 922 extern void blk_start_request(struct request *rq); 923 extern struct request *blk_fetch_request(struct request_queue *q); 924 925 /* 926 * Request completion related functions. 927 * 928 * blk_update_request() completes given number of bytes and updates 929 * the request without completing it. 930 * 931 * blk_end_request() and friends. __blk_end_request() must be called 932 * with the request queue spinlock acquired. 933 * 934 * Several drivers define their own end_request and call 935 * blk_end_request() for parts of the original function. 936 * This prevents code duplication in drivers. 937 */ 938 extern bool blk_update_request(struct request *rq, int error, 939 unsigned int nr_bytes); 940 extern bool blk_end_request(struct request *rq, int error, 941 unsigned int nr_bytes); 942 extern void blk_end_request_all(struct request *rq, int error); 943 extern bool blk_end_request_cur(struct request *rq, int error); 944 extern bool blk_end_request_err(struct request *rq, int error); 945 extern bool __blk_end_request(struct request *rq, int error, 946 unsigned int nr_bytes); 947 extern void __blk_end_request_all(struct request *rq, int error); 948 extern bool __blk_end_request_cur(struct request *rq, int error); 949 extern bool __blk_end_request_err(struct request *rq, int error); 950 951 extern void blk_complete_request(struct request *); 952 extern void __blk_complete_request(struct request *); 953 extern void blk_abort_request(struct request *); 954 extern void blk_unprep_request(struct request *); 955 956 /* 957 * Access functions for manipulating queue properties 958 */ 959 extern struct request_queue *blk_init_queue_node(request_fn_proc *rfn, 960 spinlock_t *lock, int node_id); 961 extern struct request_queue *blk_init_queue(request_fn_proc *, spinlock_t *); 962 extern struct request_queue *blk_init_allocated_queue(struct request_queue *, 963 request_fn_proc *, spinlock_t *); 964 extern void blk_cleanup_queue(struct request_queue *); 965 extern void blk_queue_make_request(struct request_queue *, make_request_fn *); 966 extern void blk_queue_bounce_limit(struct request_queue *, u64); 967 extern void blk_limits_max_hw_sectors(struct queue_limits *, unsigned int); 968 extern void blk_queue_max_hw_sectors(struct request_queue *, unsigned int); 969 extern void blk_queue_max_segments(struct request_queue *, unsigned short); 970 extern void blk_queue_max_segment_size(struct request_queue *, unsigned int); 971 extern void blk_queue_max_discard_sectors(struct request_queue *q, 972 unsigned int max_discard_sectors); 973 extern void blk_queue_max_write_same_sectors(struct request_queue *q, 974 unsigned int max_write_same_sectors); 975 extern void blk_queue_logical_block_size(struct request_queue *, unsigned short); 976 extern void blk_queue_physical_block_size(struct request_queue *, unsigned int); 977 extern void blk_queue_alignment_offset(struct request_queue *q, 978 unsigned int alignment); 979 extern void blk_limits_io_min(struct queue_limits *limits, unsigned int min); 980 extern void blk_queue_io_min(struct request_queue *q, unsigned int min); 981 extern void blk_limits_io_opt(struct queue_limits *limits, unsigned int opt); 982 extern void blk_queue_io_opt(struct request_queue *q, unsigned int opt); 983 extern void blk_set_default_limits(struct queue_limits *lim); 984 extern void blk_set_stacking_limits(struct queue_limits *lim); 985 extern int blk_stack_limits(struct queue_limits *t, struct queue_limits *b, 986 sector_t offset); 987 extern int bdev_stack_limits(struct queue_limits *t, struct block_device *bdev, 988 sector_t offset); 989 extern void disk_stack_limits(struct gendisk *disk, struct block_device *bdev, 990 sector_t offset); 991 extern void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b); 992 extern void blk_queue_dma_pad(struct request_queue *, unsigned int); 993 extern void blk_queue_update_dma_pad(struct request_queue *, unsigned int); 994 extern int blk_queue_dma_drain(struct request_queue *q, 995 dma_drain_needed_fn *dma_drain_needed, 996 void *buf, unsigned int size); 997 extern void blk_queue_lld_busy(struct request_queue *q, lld_busy_fn *fn); 998 extern void blk_queue_segment_boundary(struct request_queue *, unsigned long); 999 extern void blk_queue_prep_rq(struct request_queue *, prep_rq_fn *pfn); 1000 extern void blk_queue_unprep_rq(struct request_queue *, unprep_rq_fn *ufn); 1001 extern void blk_queue_merge_bvec(struct request_queue *, merge_bvec_fn *); 1002 extern void blk_queue_dma_alignment(struct request_queue *, int); 1003 extern void blk_queue_update_dma_alignment(struct request_queue *, int); 1004 extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *); 1005 extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *); 1006 extern void blk_queue_rq_timeout(struct request_queue *, unsigned int); 1007 extern void blk_queue_flush(struct request_queue *q, unsigned int flush); 1008 extern void blk_queue_flush_queueable(struct request_queue *q, bool queueable); 1009 extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev); 1010 1011 extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *); 1012 extern int blk_bio_map_sg(struct request_queue *q, struct bio *bio, 1013 struct scatterlist *sglist); 1014 extern void blk_dump_rq_flags(struct request *, char *); 1015 extern long nr_blockdev_pages(void); 1016 1017 bool __must_check blk_get_queue(struct request_queue *); 1018 struct request_queue *blk_alloc_queue(gfp_t); 1019 struct request_queue *blk_alloc_queue_node(gfp_t, int); 1020 extern void blk_put_queue(struct request_queue *); 1021 1022 /* 1023 * block layer runtime pm functions 1024 */ 1025 #ifdef CONFIG_PM_RUNTIME 1026 extern void blk_pm_runtime_init(struct request_queue *q, struct device *dev); 1027 extern int blk_pre_runtime_suspend(struct request_queue *q); 1028 extern void blk_post_runtime_suspend(struct request_queue *q, int err); 1029 extern void blk_pre_runtime_resume(struct request_queue *q); 1030 extern void blk_post_runtime_resume(struct request_queue *q, int err); 1031 #else 1032 static inline void blk_pm_runtime_init(struct request_queue *q, 1033 struct device *dev) {} 1034 static inline int blk_pre_runtime_suspend(struct request_queue *q) 1035 { 1036 return -ENOSYS; 1037 } 1038 static inline void blk_post_runtime_suspend(struct request_queue *q, int err) {} 1039 static inline void blk_pre_runtime_resume(struct request_queue *q) {} 1040 static inline void blk_post_runtime_resume(struct request_queue *q, int err) {} 1041 #endif 1042 1043 /* 1044 * blk_plug permits building a queue of related requests by holding the I/O 1045 * fragments for a short period. This allows merging of sequential requests 1046 * into single larger request. As the requests are moved from a per-task list to 1047 * the device's request_queue in a batch, this results in improved scalability 1048 * as the lock contention for request_queue lock is reduced. 1049 * 1050 * It is ok not to disable preemption when adding the request to the plug list 1051 * or when attempting a merge, because blk_schedule_flush_list() will only flush 1052 * the plug list when the task sleeps by itself. For details, please see 1053 * schedule() where blk_schedule_flush_plug() is called. 1054 */ 1055 struct blk_plug { 1056 unsigned long magic; /* detect uninitialized use-cases */ 1057 struct list_head list; /* requests */ 1058 struct list_head mq_list; /* blk-mq requests */ 1059 struct list_head cb_list; /* md requires an unplug callback */ 1060 }; 1061 #define BLK_MAX_REQUEST_COUNT 16 1062 1063 struct blk_plug_cb; 1064 typedef void (*blk_plug_cb_fn)(struct blk_plug_cb *, bool); 1065 struct blk_plug_cb { 1066 struct list_head list; 1067 blk_plug_cb_fn callback; 1068 void *data; 1069 }; 1070 extern struct blk_plug_cb *blk_check_plugged(blk_plug_cb_fn unplug, 1071 void *data, int size); 1072 extern void blk_start_plug(struct blk_plug *); 1073 extern void blk_finish_plug(struct blk_plug *); 1074 extern void blk_flush_plug_list(struct blk_plug *, bool); 1075 1076 static inline void blk_flush_plug(struct task_struct *tsk) 1077 { 1078 struct blk_plug *plug = tsk->plug; 1079 1080 if (plug) 1081 blk_flush_plug_list(plug, false); 1082 } 1083 1084 static inline void blk_schedule_flush_plug(struct task_struct *tsk) 1085 { 1086 struct blk_plug *plug = tsk->plug; 1087 1088 if (plug) 1089 blk_flush_plug_list(plug, true); 1090 } 1091 1092 static inline bool blk_needs_flush_plug(struct task_struct *tsk) 1093 { 1094 struct blk_plug *plug = tsk->plug; 1095 1096 return plug && 1097 (!list_empty(&plug->list) || 1098 !list_empty(&plug->mq_list) || 1099 !list_empty(&plug->cb_list)); 1100 } 1101 1102 /* 1103 * tag stuff 1104 */ 1105 #define blk_rq_tagged(rq) ((rq)->cmd_flags & REQ_QUEUED) 1106 extern int blk_queue_start_tag(struct request_queue *, struct request *); 1107 extern struct request *blk_queue_find_tag(struct request_queue *, int); 1108 extern void blk_queue_end_tag(struct request_queue *, struct request *); 1109 extern int blk_queue_init_tags(struct request_queue *, int, struct blk_queue_tag *); 1110 extern void blk_queue_free_tags(struct request_queue *); 1111 extern int blk_queue_resize_tags(struct request_queue *, int); 1112 extern void blk_queue_invalidate_tags(struct request_queue *); 1113 extern struct blk_queue_tag *blk_init_tags(int); 1114 extern void blk_free_tags(struct blk_queue_tag *); 1115 1116 static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt, 1117 int tag) 1118 { 1119 if (unlikely(bqt == NULL || tag >= bqt->real_max_depth)) 1120 return NULL; 1121 return bqt->tag_index[tag]; 1122 } 1123 1124 #define BLKDEV_DISCARD_SECURE 0x01 /* secure discard */ 1125 1126 extern int blkdev_issue_flush(struct block_device *, gfp_t, sector_t *); 1127 extern int blkdev_issue_discard(struct block_device *bdev, sector_t sector, 1128 sector_t nr_sects, gfp_t gfp_mask, unsigned long flags); 1129 extern int blkdev_issue_write_same(struct block_device *bdev, sector_t sector, 1130 sector_t nr_sects, gfp_t gfp_mask, struct page *page); 1131 extern int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector, 1132 sector_t nr_sects, gfp_t gfp_mask); 1133 static inline int sb_issue_discard(struct super_block *sb, sector_t block, 1134 sector_t nr_blocks, gfp_t gfp_mask, unsigned long flags) 1135 { 1136 return blkdev_issue_discard(sb->s_bdev, block << (sb->s_blocksize_bits - 9), 1137 nr_blocks << (sb->s_blocksize_bits - 9), 1138 gfp_mask, flags); 1139 } 1140 static inline int sb_issue_zeroout(struct super_block *sb, sector_t block, 1141 sector_t nr_blocks, gfp_t gfp_mask) 1142 { 1143 return blkdev_issue_zeroout(sb->s_bdev, 1144 block << (sb->s_blocksize_bits - 9), 1145 nr_blocks << (sb->s_blocksize_bits - 9), 1146 gfp_mask); 1147 } 1148 1149 extern int blk_verify_command(unsigned char *cmd, fmode_t has_write_perm); 1150 1151 enum blk_default_limits { 1152 BLK_MAX_SEGMENTS = 128, 1153 BLK_SAFE_MAX_SECTORS = 255, 1154 BLK_DEF_MAX_SECTORS = 1024, 1155 BLK_MAX_SEGMENT_SIZE = 65536, 1156 BLK_SEG_BOUNDARY_MASK = 0xFFFFFFFFUL, 1157 }; 1158 1159 #define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist) 1160 1161 static inline unsigned long queue_bounce_pfn(struct request_queue *q) 1162 { 1163 return q->limits.bounce_pfn; 1164 } 1165 1166 static inline unsigned long queue_segment_boundary(struct request_queue *q) 1167 { 1168 return q->limits.seg_boundary_mask; 1169 } 1170 1171 static inline unsigned int queue_max_sectors(struct request_queue *q) 1172 { 1173 return q->limits.max_sectors; 1174 } 1175 1176 static inline unsigned int queue_max_hw_sectors(struct request_queue *q) 1177 { 1178 return q->limits.max_hw_sectors; 1179 } 1180 1181 static inline unsigned short queue_max_segments(struct request_queue *q) 1182 { 1183 return q->limits.max_segments; 1184 } 1185 1186 static inline unsigned int queue_max_segment_size(struct request_queue *q) 1187 { 1188 return q->limits.max_segment_size; 1189 } 1190 1191 static inline unsigned short queue_logical_block_size(struct request_queue *q) 1192 { 1193 int retval = 512; 1194 1195 if (q && q->limits.logical_block_size) 1196 retval = q->limits.logical_block_size; 1197 1198 return retval; 1199 } 1200 1201 static inline unsigned short bdev_logical_block_size(struct block_device *bdev) 1202 { 1203 return queue_logical_block_size(bdev_get_queue(bdev)); 1204 } 1205 1206 static inline unsigned int queue_physical_block_size(struct request_queue *q) 1207 { 1208 return q->limits.physical_block_size; 1209 } 1210 1211 static inline unsigned int bdev_physical_block_size(struct block_device *bdev) 1212 { 1213 return queue_physical_block_size(bdev_get_queue(bdev)); 1214 } 1215 1216 static inline unsigned int queue_io_min(struct request_queue *q) 1217 { 1218 return q->limits.io_min; 1219 } 1220 1221 static inline int bdev_io_min(struct block_device *bdev) 1222 { 1223 return queue_io_min(bdev_get_queue(bdev)); 1224 } 1225 1226 static inline unsigned int queue_io_opt(struct request_queue *q) 1227 { 1228 return q->limits.io_opt; 1229 } 1230 1231 static inline int bdev_io_opt(struct block_device *bdev) 1232 { 1233 return queue_io_opt(bdev_get_queue(bdev)); 1234 } 1235 1236 static inline int queue_alignment_offset(struct request_queue *q) 1237 { 1238 if (q->limits.misaligned) 1239 return -1; 1240 1241 return q->limits.alignment_offset; 1242 } 1243 1244 static inline int queue_limit_alignment_offset(struct queue_limits *lim, sector_t sector) 1245 { 1246 unsigned int granularity = max(lim->physical_block_size, lim->io_min); 1247 unsigned int alignment = (sector << 9) & (granularity - 1); 1248 1249 return (granularity + lim->alignment_offset - alignment) 1250 & (granularity - 1); 1251 } 1252 1253 static inline int bdev_alignment_offset(struct block_device *bdev) 1254 { 1255 struct request_queue *q = bdev_get_queue(bdev); 1256 1257 if (q->limits.misaligned) 1258 return -1; 1259 1260 if (bdev != bdev->bd_contains) 1261 return bdev->bd_part->alignment_offset; 1262 1263 return q->limits.alignment_offset; 1264 } 1265 1266 static inline int queue_discard_alignment(struct request_queue *q) 1267 { 1268 if (q->limits.discard_misaligned) 1269 return -1; 1270 1271 return q->limits.discard_alignment; 1272 } 1273 1274 static inline int queue_limit_discard_alignment(struct queue_limits *lim, sector_t sector) 1275 { 1276 unsigned int alignment, granularity, offset; 1277 1278 if (!lim->max_discard_sectors) 1279 return 0; 1280 1281 /* Why are these in bytes, not sectors? */ 1282 alignment = lim->discard_alignment >> 9; 1283 granularity = lim->discard_granularity >> 9; 1284 if (!granularity) 1285 return 0; 1286 1287 /* Offset of the partition start in 'granularity' sectors */ 1288 offset = sector_div(sector, granularity); 1289 1290 /* And why do we do this modulus *again* in blkdev_issue_discard()? */ 1291 offset = (granularity + alignment - offset) % granularity; 1292 1293 /* Turn it back into bytes, gaah */ 1294 return offset << 9; 1295 } 1296 1297 static inline int bdev_discard_alignment(struct block_device *bdev) 1298 { 1299 struct request_queue *q = bdev_get_queue(bdev); 1300 1301 if (bdev != bdev->bd_contains) 1302 return bdev->bd_part->discard_alignment; 1303 1304 return q->limits.discard_alignment; 1305 } 1306 1307 static inline unsigned int queue_discard_zeroes_data(struct request_queue *q) 1308 { 1309 if (q->limits.max_discard_sectors && q->limits.discard_zeroes_data == 1) 1310 return 1; 1311 1312 return 0; 1313 } 1314 1315 static inline unsigned int bdev_discard_zeroes_data(struct block_device *bdev) 1316 { 1317 return queue_discard_zeroes_data(bdev_get_queue(bdev)); 1318 } 1319 1320 static inline unsigned int bdev_write_same(struct block_device *bdev) 1321 { 1322 struct request_queue *q = bdev_get_queue(bdev); 1323 1324 if (q) 1325 return q->limits.max_write_same_sectors; 1326 1327 return 0; 1328 } 1329 1330 static inline int queue_dma_alignment(struct request_queue *q) 1331 { 1332 return q ? q->dma_alignment : 511; 1333 } 1334 1335 static inline int blk_rq_aligned(struct request_queue *q, unsigned long addr, 1336 unsigned int len) 1337 { 1338 unsigned int alignment = queue_dma_alignment(q) | q->dma_pad_mask; 1339 return !(addr & alignment) && !(len & alignment); 1340 } 1341 1342 /* assumes size > 256 */ 1343 static inline unsigned int blksize_bits(unsigned int size) 1344 { 1345 unsigned int bits = 8; 1346 do { 1347 bits++; 1348 size >>= 1; 1349 } while (size > 256); 1350 return bits; 1351 } 1352 1353 static inline unsigned int block_size(struct block_device *bdev) 1354 { 1355 return bdev->bd_block_size; 1356 } 1357 1358 static inline bool queue_flush_queueable(struct request_queue *q) 1359 { 1360 return !q->flush_not_queueable; 1361 } 1362 1363 typedef struct {struct page *v;} Sector; 1364 1365 unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *); 1366 1367 static inline void put_dev_sector(Sector p) 1368 { 1369 page_cache_release(p.v); 1370 } 1371 1372 struct work_struct; 1373 int kblockd_schedule_work(struct request_queue *q, struct work_struct *work); 1374 int kblockd_schedule_delayed_work(struct request_queue *q, struct delayed_work *dwork, unsigned long delay); 1375 1376 #ifdef CONFIG_BLK_CGROUP 1377 /* 1378 * This should not be using sched_clock(). A real patch is in progress 1379 * to fix this up, until that is in place we need to disable preemption 1380 * around sched_clock() in this function and set_io_start_time_ns(). 1381 */ 1382 static inline void set_start_time_ns(struct request *req) 1383 { 1384 preempt_disable(); 1385 req->start_time_ns = sched_clock(); 1386 preempt_enable(); 1387 } 1388 1389 static inline void set_io_start_time_ns(struct request *req) 1390 { 1391 preempt_disable(); 1392 req->io_start_time_ns = sched_clock(); 1393 preempt_enable(); 1394 } 1395 1396 static inline uint64_t rq_start_time_ns(struct request *req) 1397 { 1398 return req->start_time_ns; 1399 } 1400 1401 static inline uint64_t rq_io_start_time_ns(struct request *req) 1402 { 1403 return req->io_start_time_ns; 1404 } 1405 #else 1406 static inline void set_start_time_ns(struct request *req) {} 1407 static inline void set_io_start_time_ns(struct request *req) {} 1408 static inline uint64_t rq_start_time_ns(struct request *req) 1409 { 1410 return 0; 1411 } 1412 static inline uint64_t rq_io_start_time_ns(struct request *req) 1413 { 1414 return 0; 1415 } 1416 #endif 1417 1418 #define MODULE_ALIAS_BLOCKDEV(major,minor) \ 1419 MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor)) 1420 #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \ 1421 MODULE_ALIAS("block-major-" __stringify(major) "-*") 1422 1423 #if defined(CONFIG_BLK_DEV_INTEGRITY) 1424 1425 #define INTEGRITY_FLAG_READ 2 /* verify data integrity on read */ 1426 #define INTEGRITY_FLAG_WRITE 4 /* generate data integrity on write */ 1427 1428 struct blk_integrity_exchg { 1429 void *prot_buf; 1430 void *data_buf; 1431 sector_t sector; 1432 unsigned int data_size; 1433 unsigned short sector_size; 1434 const char *disk_name; 1435 }; 1436 1437 typedef void (integrity_gen_fn) (struct blk_integrity_exchg *); 1438 typedef int (integrity_vrfy_fn) (struct blk_integrity_exchg *); 1439 typedef void (integrity_set_tag_fn) (void *, void *, unsigned int); 1440 typedef void (integrity_get_tag_fn) (void *, void *, unsigned int); 1441 1442 struct blk_integrity { 1443 integrity_gen_fn *generate_fn; 1444 integrity_vrfy_fn *verify_fn; 1445 integrity_set_tag_fn *set_tag_fn; 1446 integrity_get_tag_fn *get_tag_fn; 1447 1448 unsigned short flags; 1449 unsigned short tuple_size; 1450 unsigned short sector_size; 1451 unsigned short tag_size; 1452 1453 const char *name; 1454 1455 struct kobject kobj; 1456 }; 1457 1458 extern bool blk_integrity_is_initialized(struct gendisk *); 1459 extern int blk_integrity_register(struct gendisk *, struct blk_integrity *); 1460 extern void blk_integrity_unregister(struct gendisk *); 1461 extern int blk_integrity_compare(struct gendisk *, struct gendisk *); 1462 extern int blk_rq_map_integrity_sg(struct request_queue *, struct bio *, 1463 struct scatterlist *); 1464 extern int blk_rq_count_integrity_sg(struct request_queue *, struct bio *); 1465 extern int blk_integrity_merge_rq(struct request_queue *, struct request *, 1466 struct request *); 1467 extern int blk_integrity_merge_bio(struct request_queue *, struct request *, 1468 struct bio *); 1469 1470 static inline 1471 struct blk_integrity *bdev_get_integrity(struct block_device *bdev) 1472 { 1473 return bdev->bd_disk->integrity; 1474 } 1475 1476 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk) 1477 { 1478 return disk->integrity; 1479 } 1480 1481 static inline int blk_integrity_rq(struct request *rq) 1482 { 1483 if (rq->bio == NULL) 1484 return 0; 1485 1486 return bio_integrity(rq->bio); 1487 } 1488 1489 static inline void blk_queue_max_integrity_segments(struct request_queue *q, 1490 unsigned int segs) 1491 { 1492 q->limits.max_integrity_segments = segs; 1493 } 1494 1495 static inline unsigned short 1496 queue_max_integrity_segments(struct request_queue *q) 1497 { 1498 return q->limits.max_integrity_segments; 1499 } 1500 1501 #else /* CONFIG_BLK_DEV_INTEGRITY */ 1502 1503 struct bio; 1504 struct block_device; 1505 struct gendisk; 1506 struct blk_integrity; 1507 1508 static inline int blk_integrity_rq(struct request *rq) 1509 { 1510 return 0; 1511 } 1512 static inline int blk_rq_count_integrity_sg(struct request_queue *q, 1513 struct bio *b) 1514 { 1515 return 0; 1516 } 1517 static inline int blk_rq_map_integrity_sg(struct request_queue *q, 1518 struct bio *b, 1519 struct scatterlist *s) 1520 { 1521 return 0; 1522 } 1523 static inline struct blk_integrity *bdev_get_integrity(struct block_device *b) 1524 { 1525 return 0; 1526 } 1527 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk) 1528 { 1529 return NULL; 1530 } 1531 static inline int blk_integrity_compare(struct gendisk *a, struct gendisk *b) 1532 { 1533 return 0; 1534 } 1535 static inline int blk_integrity_register(struct gendisk *d, 1536 struct blk_integrity *b) 1537 { 1538 return 0; 1539 } 1540 static inline void blk_integrity_unregister(struct gendisk *d) 1541 { 1542 } 1543 static inline void blk_queue_max_integrity_segments(struct request_queue *q, 1544 unsigned int segs) 1545 { 1546 } 1547 static inline unsigned short queue_max_integrity_segments(struct request_queue *q) 1548 { 1549 return 0; 1550 } 1551 static inline int blk_integrity_merge_rq(struct request_queue *rq, 1552 struct request *r1, 1553 struct request *r2) 1554 { 1555 return 0; 1556 } 1557 static inline int blk_integrity_merge_bio(struct request_queue *rq, 1558 struct request *r, 1559 struct bio *b) 1560 { 1561 return 0; 1562 } 1563 static inline bool blk_integrity_is_initialized(struct gendisk *g) 1564 { 1565 return 0; 1566 } 1567 1568 #endif /* CONFIG_BLK_DEV_INTEGRITY */ 1569 1570 struct block_device_operations { 1571 int (*open) (struct block_device *, fmode_t); 1572 void (*release) (struct gendisk *, fmode_t); 1573 int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long); 1574 int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long); 1575 int (*direct_access) (struct block_device *, sector_t, 1576 void **, unsigned long *); 1577 unsigned int (*check_events) (struct gendisk *disk, 1578 unsigned int clearing); 1579 /* ->media_changed() is DEPRECATED, use ->check_events() instead */ 1580 int (*media_changed) (struct gendisk *); 1581 void (*unlock_native_capacity) (struct gendisk *); 1582 int (*revalidate_disk) (struct gendisk *); 1583 int (*getgeo)(struct block_device *, struct hd_geometry *); 1584 /* this callback is with swap_lock and sometimes page table lock held */ 1585 void (*swap_slot_free_notify) (struct block_device *, unsigned long); 1586 struct module *owner; 1587 }; 1588 1589 extern int __blkdev_driver_ioctl(struct block_device *, fmode_t, unsigned int, 1590 unsigned long); 1591 #else /* CONFIG_BLOCK */ 1592 /* 1593 * stubs for when the block layer is configured out 1594 */ 1595 #define buffer_heads_over_limit 0 1596 1597 static inline long nr_blockdev_pages(void) 1598 { 1599 return 0; 1600 } 1601 1602 struct blk_plug { 1603 }; 1604 1605 static inline void blk_start_plug(struct blk_plug *plug) 1606 { 1607 } 1608 1609 static inline void blk_finish_plug(struct blk_plug *plug) 1610 { 1611 } 1612 1613 static inline void blk_flush_plug(struct task_struct *task) 1614 { 1615 } 1616 1617 static inline void blk_schedule_flush_plug(struct task_struct *task) 1618 { 1619 } 1620 1621 1622 static inline bool blk_needs_flush_plug(struct task_struct *tsk) 1623 { 1624 return false; 1625 } 1626 1627 #endif /* CONFIG_BLOCK */ 1628 1629 #endif 1630