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 * 95 * If you modify this structure, make sure to update blk_rq_init() and 96 * especially blk_mq_rq_ctx_init() to take care of the added fields. 97 */ 98 struct request { 99 struct list_head queuelist; 100 union { 101 struct call_single_data csd; 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 */ 181 182 int tag; 183 int errors; 184 185 /* 186 * when request is used as a packet command carrier 187 */ 188 unsigned char __cmd[BLK_MAX_CDB]; 189 unsigned char *cmd; 190 unsigned short cmd_len; 191 192 unsigned int extra_len; /* length of alignment and padding */ 193 unsigned int sense_len; 194 unsigned int resid_len; /* residual count */ 195 void *sense; 196 197 unsigned long deadline; 198 struct list_head timeout_list; 199 unsigned int timeout; 200 int retries; 201 202 /* 203 * completion callback. 204 */ 205 rq_end_io_fn *end_io; 206 void *end_io_data; 207 208 /* for bidi */ 209 struct request *next_rq; 210 }; 211 212 static inline unsigned short req_get_ioprio(struct request *req) 213 { 214 return req->ioprio; 215 } 216 217 /* 218 * State information carried for REQ_TYPE_PM_SUSPEND and REQ_TYPE_PM_RESUME 219 * requests. Some step values could eventually be made generic. 220 */ 221 struct request_pm_state 222 { 223 /* PM state machine step value, currently driver specific */ 224 int pm_step; 225 /* requested PM state value (S1, S2, S3, S4, ...) */ 226 u32 pm_state; 227 void* data; /* for driver use */ 228 }; 229 230 #include <linux/elevator.h> 231 232 struct blk_queue_ctx; 233 234 typedef void (request_fn_proc) (struct request_queue *q); 235 typedef void (make_request_fn) (struct request_queue *q, struct bio *bio); 236 typedef int (prep_rq_fn) (struct request_queue *, struct request *); 237 typedef void (unprep_rq_fn) (struct request_queue *, struct request *); 238 239 struct bio_vec; 240 struct bvec_merge_data { 241 struct block_device *bi_bdev; 242 sector_t bi_sector; 243 unsigned bi_size; 244 unsigned long bi_rw; 245 }; 246 typedef int (merge_bvec_fn) (struct request_queue *, struct bvec_merge_data *, 247 struct bio_vec *); 248 typedef void (softirq_done_fn)(struct request *); 249 typedef int (dma_drain_needed_fn)(struct request *); 250 typedef int (lld_busy_fn) (struct request_queue *q); 251 typedef int (bsg_job_fn) (struct bsg_job *); 252 253 enum blk_eh_timer_return { 254 BLK_EH_NOT_HANDLED, 255 BLK_EH_HANDLED, 256 BLK_EH_RESET_TIMER, 257 }; 258 259 typedef enum blk_eh_timer_return (rq_timed_out_fn)(struct request *); 260 261 enum blk_queue_state { 262 Queue_down, 263 Queue_up, 264 }; 265 266 struct blk_queue_tag { 267 struct request **tag_index; /* map of busy tags */ 268 unsigned long *tag_map; /* bit map of free/busy tags */ 269 int busy; /* current depth */ 270 int max_depth; /* what we will send to device */ 271 int real_max_depth; /* what the array can hold */ 272 atomic_t refcnt; /* map can be shared */ 273 }; 274 275 #define BLK_SCSI_MAX_CMDS (256) 276 #define BLK_SCSI_CMD_PER_LONG (BLK_SCSI_MAX_CMDS / (sizeof(long) * 8)) 277 278 struct queue_limits { 279 unsigned long bounce_pfn; 280 unsigned long seg_boundary_mask; 281 282 unsigned int max_hw_sectors; 283 unsigned int chunk_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 __percpu *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 list_head requeue_list; 467 spinlock_t requeue_lock; 468 struct work_struct requeue_work; 469 470 struct mutex sysfs_lock; 471 472 int bypass_depth; 473 474 #if defined(CONFIG_BLK_DEV_BSG) 475 bsg_job_fn *bsg_job_fn; 476 int bsg_job_size; 477 struct bsg_class_device bsg_dev; 478 #endif 479 480 #ifdef CONFIG_BLK_DEV_THROTTLING 481 /* Throttle data */ 482 struct throtl_data *td; 483 #endif 484 struct rcu_head rcu_head; 485 wait_queue_head_t mq_freeze_wq; 486 struct percpu_counter mq_usage_counter; 487 struct list_head all_q_node; 488 489 struct blk_mq_tag_set *tag_set; 490 struct list_head tag_set_list; 491 }; 492 493 #define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */ 494 #define QUEUE_FLAG_STOPPED 2 /* queue is stopped */ 495 #define QUEUE_FLAG_SYNCFULL 3 /* read queue has been filled */ 496 #define QUEUE_FLAG_ASYNCFULL 4 /* write queue has been filled */ 497 #define QUEUE_FLAG_DYING 5 /* queue being torn down */ 498 #define QUEUE_FLAG_BYPASS 6 /* act as dumb FIFO queue */ 499 #define QUEUE_FLAG_BIDI 7 /* queue supports bidi requests */ 500 #define QUEUE_FLAG_NOMERGES 8 /* disable merge attempts */ 501 #define QUEUE_FLAG_SAME_COMP 9 /* complete on same CPU-group */ 502 #define QUEUE_FLAG_FAIL_IO 10 /* fake timeout */ 503 #define QUEUE_FLAG_STACKABLE 11 /* supports request stacking */ 504 #define QUEUE_FLAG_NONROT 12 /* non-rotational device (SSD) */ 505 #define QUEUE_FLAG_VIRT QUEUE_FLAG_NONROT /* paravirt device */ 506 #define QUEUE_FLAG_IO_STAT 13 /* do IO stats */ 507 #define QUEUE_FLAG_DISCARD 14 /* supports DISCARD */ 508 #define QUEUE_FLAG_NOXMERGES 15 /* No extended merges */ 509 #define QUEUE_FLAG_ADD_RANDOM 16 /* Contributes to random pool */ 510 #define QUEUE_FLAG_SECDISCARD 17 /* supports SECDISCARD */ 511 #define QUEUE_FLAG_SAME_FORCE 18 /* force complete on same CPU */ 512 #define QUEUE_FLAG_DEAD 19 /* queue tear-down finished */ 513 #define QUEUE_FLAG_INIT_DONE 20 /* queue is initialized */ 514 #define QUEUE_FLAG_NO_SG_MERGE 21 /* don't attempt to merge SG segments*/ 515 516 #define QUEUE_FLAG_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \ 517 (1 << QUEUE_FLAG_STACKABLE) | \ 518 (1 << QUEUE_FLAG_SAME_COMP) | \ 519 (1 << QUEUE_FLAG_ADD_RANDOM)) 520 521 #define QUEUE_FLAG_MQ_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \ 522 (1 << QUEUE_FLAG_SAME_COMP)) 523 524 static inline void queue_lockdep_assert_held(struct request_queue *q) 525 { 526 if (q->queue_lock) 527 lockdep_assert_held(q->queue_lock); 528 } 529 530 static inline void queue_flag_set_unlocked(unsigned int flag, 531 struct request_queue *q) 532 { 533 __set_bit(flag, &q->queue_flags); 534 } 535 536 static inline int queue_flag_test_and_clear(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 __clear_bit(flag, &q->queue_flags); 543 return 1; 544 } 545 546 return 0; 547 } 548 549 static inline int queue_flag_test_and_set(unsigned int flag, 550 struct request_queue *q) 551 { 552 queue_lockdep_assert_held(q); 553 554 if (!test_bit(flag, &q->queue_flags)) { 555 __set_bit(flag, &q->queue_flags); 556 return 0; 557 } 558 559 return 1; 560 } 561 562 static inline void queue_flag_set(unsigned int flag, struct request_queue *q) 563 { 564 queue_lockdep_assert_held(q); 565 __set_bit(flag, &q->queue_flags); 566 } 567 568 static inline void queue_flag_clear_unlocked(unsigned int flag, 569 struct request_queue *q) 570 { 571 __clear_bit(flag, &q->queue_flags); 572 } 573 574 static inline int queue_in_flight(struct request_queue *q) 575 { 576 return q->in_flight[0] + q->in_flight[1]; 577 } 578 579 static inline void queue_flag_clear(unsigned int flag, struct request_queue *q) 580 { 581 queue_lockdep_assert_held(q); 582 __clear_bit(flag, &q->queue_flags); 583 } 584 585 #define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags) 586 #define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags) 587 #define blk_queue_dying(q) test_bit(QUEUE_FLAG_DYING, &(q)->queue_flags) 588 #define blk_queue_dead(q) test_bit(QUEUE_FLAG_DEAD, &(q)->queue_flags) 589 #define blk_queue_bypass(q) test_bit(QUEUE_FLAG_BYPASS, &(q)->queue_flags) 590 #define blk_queue_init_done(q) test_bit(QUEUE_FLAG_INIT_DONE, &(q)->queue_flags) 591 #define blk_queue_nomerges(q) test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags) 592 #define blk_queue_noxmerges(q) \ 593 test_bit(QUEUE_FLAG_NOXMERGES, &(q)->queue_flags) 594 #define blk_queue_nonrot(q) test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags) 595 #define blk_queue_io_stat(q) test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags) 596 #define blk_queue_add_random(q) test_bit(QUEUE_FLAG_ADD_RANDOM, &(q)->queue_flags) 597 #define blk_queue_stackable(q) \ 598 test_bit(QUEUE_FLAG_STACKABLE, &(q)->queue_flags) 599 #define blk_queue_discard(q) test_bit(QUEUE_FLAG_DISCARD, &(q)->queue_flags) 600 #define blk_queue_secdiscard(q) (blk_queue_discard(q) && \ 601 test_bit(QUEUE_FLAG_SECDISCARD, &(q)->queue_flags)) 602 603 #define blk_noretry_request(rq) \ 604 ((rq)->cmd_flags & (REQ_FAILFAST_DEV|REQ_FAILFAST_TRANSPORT| \ 605 REQ_FAILFAST_DRIVER)) 606 607 #define blk_account_rq(rq) \ 608 (((rq)->cmd_flags & REQ_STARTED) && \ 609 ((rq)->cmd_type == REQ_TYPE_FS)) 610 611 #define blk_pm_request(rq) \ 612 ((rq)->cmd_type == REQ_TYPE_PM_SUSPEND || \ 613 (rq)->cmd_type == REQ_TYPE_PM_RESUME) 614 615 #define blk_rq_cpu_valid(rq) ((rq)->cpu != -1) 616 #define blk_bidi_rq(rq) ((rq)->next_rq != NULL) 617 /* rq->queuelist of dequeued request must be list_empty() */ 618 #define blk_queued_rq(rq) (!list_empty(&(rq)->queuelist)) 619 620 #define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist) 621 622 #define rq_data_dir(rq) (((rq)->cmd_flags & 1) != 0) 623 624 /* 625 * Driver can handle struct request, if it either has an old style 626 * request_fn defined, or is blk-mq based. 627 */ 628 static inline bool queue_is_rq_based(struct request_queue *q) 629 { 630 return q->request_fn || q->mq_ops; 631 } 632 633 static inline unsigned int blk_queue_cluster(struct request_queue *q) 634 { 635 return q->limits.cluster; 636 } 637 638 /* 639 * We regard a request as sync, if either a read or a sync write 640 */ 641 static inline bool rw_is_sync(unsigned int rw_flags) 642 { 643 return !(rw_flags & REQ_WRITE) || (rw_flags & REQ_SYNC); 644 } 645 646 static inline bool rq_is_sync(struct request *rq) 647 { 648 return rw_is_sync(rq->cmd_flags); 649 } 650 651 static inline bool blk_rl_full(struct request_list *rl, bool sync) 652 { 653 unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL; 654 655 return rl->flags & flag; 656 } 657 658 static inline void blk_set_rl_full(struct request_list *rl, bool sync) 659 { 660 unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL; 661 662 rl->flags |= flag; 663 } 664 665 static inline void blk_clear_rl_full(struct request_list *rl, bool sync) 666 { 667 unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL; 668 669 rl->flags &= ~flag; 670 } 671 672 static inline bool rq_mergeable(struct request *rq) 673 { 674 if (rq->cmd_type != REQ_TYPE_FS) 675 return false; 676 677 if (rq->cmd_flags & REQ_NOMERGE_FLAGS) 678 return false; 679 680 return true; 681 } 682 683 static inline bool blk_check_merge_flags(unsigned int flags1, 684 unsigned int flags2) 685 { 686 if ((flags1 & REQ_DISCARD) != (flags2 & REQ_DISCARD)) 687 return false; 688 689 if ((flags1 & REQ_SECURE) != (flags2 & REQ_SECURE)) 690 return false; 691 692 if ((flags1 & REQ_WRITE_SAME) != (flags2 & REQ_WRITE_SAME)) 693 return false; 694 695 return true; 696 } 697 698 static inline bool blk_write_same_mergeable(struct bio *a, struct bio *b) 699 { 700 if (bio_data(a) == bio_data(b)) 701 return true; 702 703 return false; 704 } 705 706 /* 707 * q->prep_rq_fn return values 708 */ 709 #define BLKPREP_OK 0 /* serve it */ 710 #define BLKPREP_KILL 1 /* fatal error, kill */ 711 #define BLKPREP_DEFER 2 /* leave on queue */ 712 713 extern unsigned long blk_max_low_pfn, blk_max_pfn; 714 715 /* 716 * standard bounce addresses: 717 * 718 * BLK_BOUNCE_HIGH : bounce all highmem pages 719 * BLK_BOUNCE_ANY : don't bounce anything 720 * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary 721 */ 722 723 #if BITS_PER_LONG == 32 724 #define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT) 725 #else 726 #define BLK_BOUNCE_HIGH -1ULL 727 #endif 728 #define BLK_BOUNCE_ANY (-1ULL) 729 #define BLK_BOUNCE_ISA (DMA_BIT_MASK(24)) 730 731 /* 732 * default timeout for SG_IO if none specified 733 */ 734 #define BLK_DEFAULT_SG_TIMEOUT (60 * HZ) 735 #define BLK_MIN_SG_TIMEOUT (7 * HZ) 736 737 #ifdef CONFIG_BOUNCE 738 extern int init_emergency_isa_pool(void); 739 extern void blk_queue_bounce(struct request_queue *q, struct bio **bio); 740 #else 741 static inline int init_emergency_isa_pool(void) 742 { 743 return 0; 744 } 745 static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio) 746 { 747 } 748 #endif /* CONFIG_MMU */ 749 750 struct rq_map_data { 751 struct page **pages; 752 int page_order; 753 int nr_entries; 754 unsigned long offset; 755 int null_mapped; 756 int from_user; 757 }; 758 759 struct req_iterator { 760 struct bvec_iter iter; 761 struct bio *bio; 762 }; 763 764 /* This should not be used directly - use rq_for_each_segment */ 765 #define for_each_bio(_bio) \ 766 for (; _bio; _bio = _bio->bi_next) 767 #define __rq_for_each_bio(_bio, rq) \ 768 if ((rq->bio)) \ 769 for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next) 770 771 #define rq_for_each_segment(bvl, _rq, _iter) \ 772 __rq_for_each_bio(_iter.bio, _rq) \ 773 bio_for_each_segment(bvl, _iter.bio, _iter.iter) 774 775 #define rq_iter_last(bvec, _iter) \ 776 (_iter.bio->bi_next == NULL && \ 777 bio_iter_last(bvec, _iter.iter)) 778 779 #ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 780 # error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform" 781 #endif 782 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 783 extern void rq_flush_dcache_pages(struct request *rq); 784 #else 785 static inline void rq_flush_dcache_pages(struct request *rq) 786 { 787 } 788 #endif 789 790 extern int blk_register_queue(struct gendisk *disk); 791 extern void blk_unregister_queue(struct gendisk *disk); 792 extern void generic_make_request(struct bio *bio); 793 extern void blk_rq_init(struct request_queue *q, struct request *rq); 794 extern void blk_put_request(struct request *); 795 extern void __blk_put_request(struct request_queue *, struct request *); 796 extern struct request *blk_get_request(struct request_queue *, int, gfp_t); 797 extern struct request *blk_make_request(struct request_queue *, struct bio *, 798 gfp_t); 799 extern void blk_rq_set_block_pc(struct request *); 800 extern void blk_requeue_request(struct request_queue *, struct request *); 801 extern void blk_add_request_payload(struct request *rq, struct page *page, 802 unsigned int len); 803 extern int blk_rq_check_limits(struct request_queue *q, struct request *rq); 804 extern int blk_lld_busy(struct request_queue *q); 805 extern int blk_rq_prep_clone(struct request *rq, struct request *rq_src, 806 struct bio_set *bs, gfp_t gfp_mask, 807 int (*bio_ctr)(struct bio *, struct bio *, void *), 808 void *data); 809 extern void blk_rq_unprep_clone(struct request *rq); 810 extern int blk_insert_cloned_request(struct request_queue *q, 811 struct request *rq); 812 extern void blk_delay_queue(struct request_queue *, unsigned long); 813 extern void blk_recount_segments(struct request_queue *, struct bio *); 814 extern int scsi_verify_blk_ioctl(struct block_device *, unsigned int); 815 extern int scsi_cmd_blk_ioctl(struct block_device *, fmode_t, 816 unsigned int, void __user *); 817 extern int scsi_cmd_ioctl(struct request_queue *, struct gendisk *, fmode_t, 818 unsigned int, void __user *); 819 extern int sg_scsi_ioctl(struct request_queue *, struct gendisk *, fmode_t, 820 struct scsi_ioctl_command __user *); 821 822 extern void blk_queue_bio(struct request_queue *q, struct bio *bio); 823 824 /* 825 * A queue has just exitted congestion. Note this in the global counter of 826 * congested queues, and wake up anyone who was waiting for requests to be 827 * put back. 828 */ 829 static inline void blk_clear_queue_congested(struct request_queue *q, int sync) 830 { 831 clear_bdi_congested(&q->backing_dev_info, sync); 832 } 833 834 /* 835 * A queue has just entered congestion. Flag that in the queue's VM-visible 836 * state flags and increment the global gounter of congested queues. 837 */ 838 static inline void blk_set_queue_congested(struct request_queue *q, int sync) 839 { 840 set_bdi_congested(&q->backing_dev_info, sync); 841 } 842 843 extern void blk_start_queue(struct request_queue *q); 844 extern void blk_stop_queue(struct request_queue *q); 845 extern void blk_sync_queue(struct request_queue *q); 846 extern void __blk_stop_queue(struct request_queue *q); 847 extern void __blk_run_queue(struct request_queue *q); 848 extern void blk_run_queue(struct request_queue *); 849 extern void blk_run_queue_async(struct request_queue *q); 850 extern int blk_rq_map_user(struct request_queue *, struct request *, 851 struct rq_map_data *, void __user *, unsigned long, 852 gfp_t); 853 extern int blk_rq_unmap_user(struct bio *); 854 extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, unsigned int, gfp_t); 855 extern int blk_rq_map_user_iov(struct request_queue *, struct request *, 856 struct rq_map_data *, const struct sg_iovec *, 857 int, unsigned int, gfp_t); 858 extern int blk_execute_rq(struct request_queue *, struct gendisk *, 859 struct request *, int); 860 extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *, 861 struct request *, int, rq_end_io_fn *); 862 863 static inline struct request_queue *bdev_get_queue(struct block_device *bdev) 864 { 865 return bdev->bd_disk->queue; 866 } 867 868 /* 869 * blk_rq_pos() : the current sector 870 * blk_rq_bytes() : bytes left in the entire request 871 * blk_rq_cur_bytes() : bytes left in the current segment 872 * blk_rq_err_bytes() : bytes left till the next error boundary 873 * blk_rq_sectors() : sectors left in the entire request 874 * blk_rq_cur_sectors() : sectors left in the current segment 875 */ 876 static inline sector_t blk_rq_pos(const struct request *rq) 877 { 878 return rq->__sector; 879 } 880 881 static inline unsigned int blk_rq_bytes(const struct request *rq) 882 { 883 return rq->__data_len; 884 } 885 886 static inline int blk_rq_cur_bytes(const struct request *rq) 887 { 888 return rq->bio ? bio_cur_bytes(rq->bio) : 0; 889 } 890 891 extern unsigned int blk_rq_err_bytes(const struct request *rq); 892 893 static inline unsigned int blk_rq_sectors(const struct request *rq) 894 { 895 return blk_rq_bytes(rq) >> 9; 896 } 897 898 static inline unsigned int blk_rq_cur_sectors(const struct request *rq) 899 { 900 return blk_rq_cur_bytes(rq) >> 9; 901 } 902 903 static inline unsigned int blk_queue_get_max_sectors(struct request_queue *q, 904 unsigned int cmd_flags) 905 { 906 if (unlikely(cmd_flags & REQ_DISCARD)) 907 return min(q->limits.max_discard_sectors, UINT_MAX >> 9); 908 909 if (unlikely(cmd_flags & REQ_WRITE_SAME)) 910 return q->limits.max_write_same_sectors; 911 912 return q->limits.max_sectors; 913 } 914 915 /* 916 * Return maximum size of a request at given offset. Only valid for 917 * file system requests. 918 */ 919 static inline unsigned int blk_max_size_offset(struct request_queue *q, 920 sector_t offset) 921 { 922 if (!q->limits.chunk_sectors) 923 return q->limits.max_sectors; 924 925 return q->limits.chunk_sectors - 926 (offset & (q->limits.chunk_sectors - 1)); 927 } 928 929 static inline unsigned int blk_rq_get_max_sectors(struct request *rq) 930 { 931 struct request_queue *q = rq->q; 932 933 if (unlikely(rq->cmd_type == REQ_TYPE_BLOCK_PC)) 934 return q->limits.max_hw_sectors; 935 936 if (!q->limits.chunk_sectors) 937 return blk_queue_get_max_sectors(q, rq->cmd_flags); 938 939 return min(blk_max_size_offset(q, blk_rq_pos(rq)), 940 blk_queue_get_max_sectors(q, rq->cmd_flags)); 941 } 942 943 static inline unsigned int blk_rq_count_bios(struct request *rq) 944 { 945 unsigned int nr_bios = 0; 946 struct bio *bio; 947 948 __rq_for_each_bio(bio, rq) 949 nr_bios++; 950 951 return nr_bios; 952 } 953 954 /* 955 * Request issue related functions. 956 */ 957 extern struct request *blk_peek_request(struct request_queue *q); 958 extern void blk_start_request(struct request *rq); 959 extern struct request *blk_fetch_request(struct request_queue *q); 960 961 /* 962 * Request completion related functions. 963 * 964 * blk_update_request() completes given number of bytes and updates 965 * the request without completing it. 966 * 967 * blk_end_request() and friends. __blk_end_request() must be called 968 * with the request queue spinlock acquired. 969 * 970 * Several drivers define their own end_request and call 971 * blk_end_request() for parts of the original function. 972 * This prevents code duplication in drivers. 973 */ 974 extern bool blk_update_request(struct request *rq, int error, 975 unsigned int nr_bytes); 976 extern void blk_finish_request(struct request *rq, int error); 977 extern bool blk_end_request(struct request *rq, int error, 978 unsigned int nr_bytes); 979 extern void blk_end_request_all(struct request *rq, int error); 980 extern bool blk_end_request_cur(struct request *rq, int error); 981 extern bool blk_end_request_err(struct request *rq, int error); 982 extern bool __blk_end_request(struct request *rq, int error, 983 unsigned int nr_bytes); 984 extern void __blk_end_request_all(struct request *rq, int error); 985 extern bool __blk_end_request_cur(struct request *rq, int error); 986 extern bool __blk_end_request_err(struct request *rq, int error); 987 988 extern void blk_complete_request(struct request *); 989 extern void __blk_complete_request(struct request *); 990 extern void blk_abort_request(struct request *); 991 extern void blk_unprep_request(struct request *); 992 993 /* 994 * Access functions for manipulating queue properties 995 */ 996 extern struct request_queue *blk_init_queue_node(request_fn_proc *rfn, 997 spinlock_t *lock, int node_id); 998 extern struct request_queue *blk_init_queue(request_fn_proc *, spinlock_t *); 999 extern struct request_queue *blk_init_allocated_queue(struct request_queue *, 1000 request_fn_proc *, spinlock_t *); 1001 extern void blk_cleanup_queue(struct request_queue *); 1002 extern void blk_queue_make_request(struct request_queue *, make_request_fn *); 1003 extern void blk_queue_bounce_limit(struct request_queue *, u64); 1004 extern void blk_limits_max_hw_sectors(struct queue_limits *, unsigned int); 1005 extern void blk_queue_max_hw_sectors(struct request_queue *, unsigned int); 1006 extern void blk_queue_chunk_sectors(struct request_queue *, unsigned int); 1007 extern void blk_queue_max_segments(struct request_queue *, unsigned short); 1008 extern void blk_queue_max_segment_size(struct request_queue *, unsigned int); 1009 extern void blk_queue_max_discard_sectors(struct request_queue *q, 1010 unsigned int max_discard_sectors); 1011 extern void blk_queue_max_write_same_sectors(struct request_queue *q, 1012 unsigned int max_write_same_sectors); 1013 extern void blk_queue_logical_block_size(struct request_queue *, unsigned short); 1014 extern void blk_queue_physical_block_size(struct request_queue *, unsigned int); 1015 extern void blk_queue_alignment_offset(struct request_queue *q, 1016 unsigned int alignment); 1017 extern void blk_limits_io_min(struct queue_limits *limits, unsigned int min); 1018 extern void blk_queue_io_min(struct request_queue *q, unsigned int min); 1019 extern void blk_limits_io_opt(struct queue_limits *limits, unsigned int opt); 1020 extern void blk_queue_io_opt(struct request_queue *q, unsigned int opt); 1021 extern void blk_set_default_limits(struct queue_limits *lim); 1022 extern void blk_set_stacking_limits(struct queue_limits *lim); 1023 extern int blk_stack_limits(struct queue_limits *t, struct queue_limits *b, 1024 sector_t offset); 1025 extern int bdev_stack_limits(struct queue_limits *t, struct block_device *bdev, 1026 sector_t offset); 1027 extern void disk_stack_limits(struct gendisk *disk, struct block_device *bdev, 1028 sector_t offset); 1029 extern void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b); 1030 extern void blk_queue_dma_pad(struct request_queue *, unsigned int); 1031 extern void blk_queue_update_dma_pad(struct request_queue *, unsigned int); 1032 extern int blk_queue_dma_drain(struct request_queue *q, 1033 dma_drain_needed_fn *dma_drain_needed, 1034 void *buf, unsigned int size); 1035 extern void blk_queue_lld_busy(struct request_queue *q, lld_busy_fn *fn); 1036 extern void blk_queue_segment_boundary(struct request_queue *, unsigned long); 1037 extern void blk_queue_prep_rq(struct request_queue *, prep_rq_fn *pfn); 1038 extern void blk_queue_unprep_rq(struct request_queue *, unprep_rq_fn *ufn); 1039 extern void blk_queue_merge_bvec(struct request_queue *, merge_bvec_fn *); 1040 extern void blk_queue_dma_alignment(struct request_queue *, int); 1041 extern void blk_queue_update_dma_alignment(struct request_queue *, int); 1042 extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *); 1043 extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *); 1044 extern void blk_queue_rq_timeout(struct request_queue *, unsigned int); 1045 extern void blk_queue_flush(struct request_queue *q, unsigned int flush); 1046 extern void blk_queue_flush_queueable(struct request_queue *q, bool queueable); 1047 extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev); 1048 1049 extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *); 1050 extern int blk_bio_map_sg(struct request_queue *q, struct bio *bio, 1051 struct scatterlist *sglist); 1052 extern void blk_dump_rq_flags(struct request *, char *); 1053 extern long nr_blockdev_pages(void); 1054 1055 bool __must_check blk_get_queue(struct request_queue *); 1056 struct request_queue *blk_alloc_queue(gfp_t); 1057 struct request_queue *blk_alloc_queue_node(gfp_t, int); 1058 extern void blk_put_queue(struct request_queue *); 1059 1060 /* 1061 * block layer runtime pm functions 1062 */ 1063 #ifdef CONFIG_PM_RUNTIME 1064 extern void blk_pm_runtime_init(struct request_queue *q, struct device *dev); 1065 extern int blk_pre_runtime_suspend(struct request_queue *q); 1066 extern void blk_post_runtime_suspend(struct request_queue *q, int err); 1067 extern void blk_pre_runtime_resume(struct request_queue *q); 1068 extern void blk_post_runtime_resume(struct request_queue *q, int err); 1069 #else 1070 static inline void blk_pm_runtime_init(struct request_queue *q, 1071 struct device *dev) {} 1072 static inline int blk_pre_runtime_suspend(struct request_queue *q) 1073 { 1074 return -ENOSYS; 1075 } 1076 static inline void blk_post_runtime_suspend(struct request_queue *q, int err) {} 1077 static inline void blk_pre_runtime_resume(struct request_queue *q) {} 1078 static inline void blk_post_runtime_resume(struct request_queue *q, int err) {} 1079 #endif 1080 1081 /* 1082 * blk_plug permits building a queue of related requests by holding the I/O 1083 * fragments for a short period. This allows merging of sequential requests 1084 * into single larger request. As the requests are moved from a per-task list to 1085 * the device's request_queue in a batch, this results in improved scalability 1086 * as the lock contention for request_queue lock is reduced. 1087 * 1088 * It is ok not to disable preemption when adding the request to the plug list 1089 * or when attempting a merge, because blk_schedule_flush_list() will only flush 1090 * the plug list when the task sleeps by itself. For details, please see 1091 * schedule() where blk_schedule_flush_plug() is called. 1092 */ 1093 struct blk_plug { 1094 struct list_head list; /* requests */ 1095 struct list_head mq_list; /* blk-mq requests */ 1096 struct list_head cb_list; /* md requires an unplug callback */ 1097 }; 1098 #define BLK_MAX_REQUEST_COUNT 16 1099 1100 struct blk_plug_cb; 1101 typedef void (*blk_plug_cb_fn)(struct blk_plug_cb *, bool); 1102 struct blk_plug_cb { 1103 struct list_head list; 1104 blk_plug_cb_fn callback; 1105 void *data; 1106 }; 1107 extern struct blk_plug_cb *blk_check_plugged(blk_plug_cb_fn unplug, 1108 void *data, int size); 1109 extern void blk_start_plug(struct blk_plug *); 1110 extern void blk_finish_plug(struct blk_plug *); 1111 extern void blk_flush_plug_list(struct blk_plug *, bool); 1112 1113 static inline void blk_flush_plug(struct task_struct *tsk) 1114 { 1115 struct blk_plug *plug = tsk->plug; 1116 1117 if (plug) 1118 blk_flush_plug_list(plug, false); 1119 } 1120 1121 static inline void blk_schedule_flush_plug(struct task_struct *tsk) 1122 { 1123 struct blk_plug *plug = tsk->plug; 1124 1125 if (plug) 1126 blk_flush_plug_list(plug, true); 1127 } 1128 1129 static inline bool blk_needs_flush_plug(struct task_struct *tsk) 1130 { 1131 struct blk_plug *plug = tsk->plug; 1132 1133 return plug && 1134 (!list_empty(&plug->list) || 1135 !list_empty(&plug->mq_list) || 1136 !list_empty(&plug->cb_list)); 1137 } 1138 1139 /* 1140 * tag stuff 1141 */ 1142 #define blk_rq_tagged(rq) \ 1143 ((rq)->mq_ctx || ((rq)->cmd_flags & REQ_QUEUED)) 1144 extern int blk_queue_start_tag(struct request_queue *, struct request *); 1145 extern struct request *blk_queue_find_tag(struct request_queue *, int); 1146 extern void blk_queue_end_tag(struct request_queue *, struct request *); 1147 extern int blk_queue_init_tags(struct request_queue *, int, struct blk_queue_tag *); 1148 extern void blk_queue_free_tags(struct request_queue *); 1149 extern int blk_queue_resize_tags(struct request_queue *, int); 1150 extern void blk_queue_invalidate_tags(struct request_queue *); 1151 extern struct blk_queue_tag *blk_init_tags(int); 1152 extern void blk_free_tags(struct blk_queue_tag *); 1153 1154 static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt, 1155 int tag) 1156 { 1157 if (unlikely(bqt == NULL || tag >= bqt->real_max_depth)) 1158 return NULL; 1159 return bqt->tag_index[tag]; 1160 } 1161 1162 #define BLKDEV_DISCARD_SECURE 0x01 /* secure discard */ 1163 1164 extern int blkdev_issue_flush(struct block_device *, gfp_t, sector_t *); 1165 extern int blkdev_issue_discard(struct block_device *bdev, sector_t sector, 1166 sector_t nr_sects, gfp_t gfp_mask, unsigned long flags); 1167 extern int blkdev_issue_write_same(struct block_device *bdev, sector_t sector, 1168 sector_t nr_sects, gfp_t gfp_mask, struct page *page); 1169 extern int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector, 1170 sector_t nr_sects, gfp_t gfp_mask); 1171 static inline int sb_issue_discard(struct super_block *sb, sector_t block, 1172 sector_t nr_blocks, gfp_t gfp_mask, unsigned long flags) 1173 { 1174 return blkdev_issue_discard(sb->s_bdev, block << (sb->s_blocksize_bits - 9), 1175 nr_blocks << (sb->s_blocksize_bits - 9), 1176 gfp_mask, flags); 1177 } 1178 static inline int sb_issue_zeroout(struct super_block *sb, sector_t block, 1179 sector_t nr_blocks, gfp_t gfp_mask) 1180 { 1181 return blkdev_issue_zeroout(sb->s_bdev, 1182 block << (sb->s_blocksize_bits - 9), 1183 nr_blocks << (sb->s_blocksize_bits - 9), 1184 gfp_mask); 1185 } 1186 1187 extern int blk_verify_command(unsigned char *cmd, fmode_t has_write_perm); 1188 1189 enum blk_default_limits { 1190 BLK_MAX_SEGMENTS = 128, 1191 BLK_SAFE_MAX_SECTORS = 255, 1192 BLK_DEF_MAX_SECTORS = 1024, 1193 BLK_MAX_SEGMENT_SIZE = 65536, 1194 BLK_SEG_BOUNDARY_MASK = 0xFFFFFFFFUL, 1195 }; 1196 1197 #define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist) 1198 1199 static inline unsigned long queue_bounce_pfn(struct request_queue *q) 1200 { 1201 return q->limits.bounce_pfn; 1202 } 1203 1204 static inline unsigned long queue_segment_boundary(struct request_queue *q) 1205 { 1206 return q->limits.seg_boundary_mask; 1207 } 1208 1209 static inline unsigned int queue_max_sectors(struct request_queue *q) 1210 { 1211 return q->limits.max_sectors; 1212 } 1213 1214 static inline unsigned int queue_max_hw_sectors(struct request_queue *q) 1215 { 1216 return q->limits.max_hw_sectors; 1217 } 1218 1219 static inline unsigned short queue_max_segments(struct request_queue *q) 1220 { 1221 return q->limits.max_segments; 1222 } 1223 1224 static inline unsigned int queue_max_segment_size(struct request_queue *q) 1225 { 1226 return q->limits.max_segment_size; 1227 } 1228 1229 static inline unsigned short queue_logical_block_size(struct request_queue *q) 1230 { 1231 int retval = 512; 1232 1233 if (q && q->limits.logical_block_size) 1234 retval = q->limits.logical_block_size; 1235 1236 return retval; 1237 } 1238 1239 static inline unsigned short bdev_logical_block_size(struct block_device *bdev) 1240 { 1241 return queue_logical_block_size(bdev_get_queue(bdev)); 1242 } 1243 1244 static inline unsigned int queue_physical_block_size(struct request_queue *q) 1245 { 1246 return q->limits.physical_block_size; 1247 } 1248 1249 static inline unsigned int bdev_physical_block_size(struct block_device *bdev) 1250 { 1251 return queue_physical_block_size(bdev_get_queue(bdev)); 1252 } 1253 1254 static inline unsigned int queue_io_min(struct request_queue *q) 1255 { 1256 return q->limits.io_min; 1257 } 1258 1259 static inline int bdev_io_min(struct block_device *bdev) 1260 { 1261 return queue_io_min(bdev_get_queue(bdev)); 1262 } 1263 1264 static inline unsigned int queue_io_opt(struct request_queue *q) 1265 { 1266 return q->limits.io_opt; 1267 } 1268 1269 static inline int bdev_io_opt(struct block_device *bdev) 1270 { 1271 return queue_io_opt(bdev_get_queue(bdev)); 1272 } 1273 1274 static inline int queue_alignment_offset(struct request_queue *q) 1275 { 1276 if (q->limits.misaligned) 1277 return -1; 1278 1279 return q->limits.alignment_offset; 1280 } 1281 1282 static inline int queue_limit_alignment_offset(struct queue_limits *lim, sector_t sector) 1283 { 1284 unsigned int granularity = max(lim->physical_block_size, lim->io_min); 1285 unsigned int alignment = (sector << 9) & (granularity - 1); 1286 1287 return (granularity + lim->alignment_offset - alignment) 1288 & (granularity - 1); 1289 } 1290 1291 static inline int bdev_alignment_offset(struct block_device *bdev) 1292 { 1293 struct request_queue *q = bdev_get_queue(bdev); 1294 1295 if (q->limits.misaligned) 1296 return -1; 1297 1298 if (bdev != bdev->bd_contains) 1299 return bdev->bd_part->alignment_offset; 1300 1301 return q->limits.alignment_offset; 1302 } 1303 1304 static inline int queue_discard_alignment(struct request_queue *q) 1305 { 1306 if (q->limits.discard_misaligned) 1307 return -1; 1308 1309 return q->limits.discard_alignment; 1310 } 1311 1312 static inline int queue_limit_discard_alignment(struct queue_limits *lim, sector_t sector) 1313 { 1314 unsigned int alignment, granularity, offset; 1315 1316 if (!lim->max_discard_sectors) 1317 return 0; 1318 1319 /* Why are these in bytes, not sectors? */ 1320 alignment = lim->discard_alignment >> 9; 1321 granularity = lim->discard_granularity >> 9; 1322 if (!granularity) 1323 return 0; 1324 1325 /* Offset of the partition start in 'granularity' sectors */ 1326 offset = sector_div(sector, granularity); 1327 1328 /* And why do we do this modulus *again* in blkdev_issue_discard()? */ 1329 offset = (granularity + alignment - offset) % granularity; 1330 1331 /* Turn it back into bytes, gaah */ 1332 return offset << 9; 1333 } 1334 1335 static inline int bdev_discard_alignment(struct block_device *bdev) 1336 { 1337 struct request_queue *q = bdev_get_queue(bdev); 1338 1339 if (bdev != bdev->bd_contains) 1340 return bdev->bd_part->discard_alignment; 1341 1342 return q->limits.discard_alignment; 1343 } 1344 1345 static inline unsigned int queue_discard_zeroes_data(struct request_queue *q) 1346 { 1347 if (q->limits.max_discard_sectors && q->limits.discard_zeroes_data == 1) 1348 return 1; 1349 1350 return 0; 1351 } 1352 1353 static inline unsigned int bdev_discard_zeroes_data(struct block_device *bdev) 1354 { 1355 return queue_discard_zeroes_data(bdev_get_queue(bdev)); 1356 } 1357 1358 static inline unsigned int bdev_write_same(struct block_device *bdev) 1359 { 1360 struct request_queue *q = bdev_get_queue(bdev); 1361 1362 if (q) 1363 return q->limits.max_write_same_sectors; 1364 1365 return 0; 1366 } 1367 1368 static inline int queue_dma_alignment(struct request_queue *q) 1369 { 1370 return q ? q->dma_alignment : 511; 1371 } 1372 1373 static inline int blk_rq_aligned(struct request_queue *q, unsigned long addr, 1374 unsigned int len) 1375 { 1376 unsigned int alignment = queue_dma_alignment(q) | q->dma_pad_mask; 1377 return !(addr & alignment) && !(len & alignment); 1378 } 1379 1380 /* assumes size > 256 */ 1381 static inline unsigned int blksize_bits(unsigned int size) 1382 { 1383 unsigned int bits = 8; 1384 do { 1385 bits++; 1386 size >>= 1; 1387 } while (size > 256); 1388 return bits; 1389 } 1390 1391 static inline unsigned int block_size(struct block_device *bdev) 1392 { 1393 return bdev->bd_block_size; 1394 } 1395 1396 static inline bool queue_flush_queueable(struct request_queue *q) 1397 { 1398 return !q->flush_not_queueable; 1399 } 1400 1401 typedef struct {struct page *v;} Sector; 1402 1403 unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *); 1404 1405 static inline void put_dev_sector(Sector p) 1406 { 1407 page_cache_release(p.v); 1408 } 1409 1410 struct work_struct; 1411 int kblockd_schedule_work(struct work_struct *work); 1412 int kblockd_schedule_delayed_work(struct delayed_work *dwork, unsigned long delay); 1413 int kblockd_schedule_delayed_work_on(int cpu, struct delayed_work *dwork, unsigned long delay); 1414 1415 #ifdef CONFIG_BLK_CGROUP 1416 /* 1417 * This should not be using sched_clock(). A real patch is in progress 1418 * to fix this up, until that is in place we need to disable preemption 1419 * around sched_clock() in this function and set_io_start_time_ns(). 1420 */ 1421 static inline void set_start_time_ns(struct request *req) 1422 { 1423 preempt_disable(); 1424 req->start_time_ns = sched_clock(); 1425 preempt_enable(); 1426 } 1427 1428 static inline void set_io_start_time_ns(struct request *req) 1429 { 1430 preempt_disable(); 1431 req->io_start_time_ns = sched_clock(); 1432 preempt_enable(); 1433 } 1434 1435 static inline uint64_t rq_start_time_ns(struct request *req) 1436 { 1437 return req->start_time_ns; 1438 } 1439 1440 static inline uint64_t rq_io_start_time_ns(struct request *req) 1441 { 1442 return req->io_start_time_ns; 1443 } 1444 #else 1445 static inline void set_start_time_ns(struct request *req) {} 1446 static inline void set_io_start_time_ns(struct request *req) {} 1447 static inline uint64_t rq_start_time_ns(struct request *req) 1448 { 1449 return 0; 1450 } 1451 static inline uint64_t rq_io_start_time_ns(struct request *req) 1452 { 1453 return 0; 1454 } 1455 #endif 1456 1457 #define MODULE_ALIAS_BLOCKDEV(major,minor) \ 1458 MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor)) 1459 #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \ 1460 MODULE_ALIAS("block-major-" __stringify(major) "-*") 1461 1462 #if defined(CONFIG_BLK_DEV_INTEGRITY) 1463 1464 #define INTEGRITY_FLAG_READ 2 /* verify data integrity on read */ 1465 #define INTEGRITY_FLAG_WRITE 4 /* generate data integrity on write */ 1466 1467 struct blk_integrity_exchg { 1468 void *prot_buf; 1469 void *data_buf; 1470 sector_t sector; 1471 unsigned int data_size; 1472 unsigned short sector_size; 1473 const char *disk_name; 1474 }; 1475 1476 typedef void (integrity_gen_fn) (struct blk_integrity_exchg *); 1477 typedef int (integrity_vrfy_fn) (struct blk_integrity_exchg *); 1478 typedef void (integrity_set_tag_fn) (void *, void *, unsigned int); 1479 typedef void (integrity_get_tag_fn) (void *, void *, unsigned int); 1480 1481 struct blk_integrity { 1482 integrity_gen_fn *generate_fn; 1483 integrity_vrfy_fn *verify_fn; 1484 integrity_set_tag_fn *set_tag_fn; 1485 integrity_get_tag_fn *get_tag_fn; 1486 1487 unsigned short flags; 1488 unsigned short tuple_size; 1489 unsigned short sector_size; 1490 unsigned short tag_size; 1491 1492 const char *name; 1493 1494 struct kobject kobj; 1495 }; 1496 1497 extern bool blk_integrity_is_initialized(struct gendisk *); 1498 extern int blk_integrity_register(struct gendisk *, struct blk_integrity *); 1499 extern void blk_integrity_unregister(struct gendisk *); 1500 extern int blk_integrity_compare(struct gendisk *, struct gendisk *); 1501 extern int blk_rq_map_integrity_sg(struct request_queue *, struct bio *, 1502 struct scatterlist *); 1503 extern int blk_rq_count_integrity_sg(struct request_queue *, struct bio *); 1504 extern int blk_integrity_merge_rq(struct request_queue *, struct request *, 1505 struct request *); 1506 extern int blk_integrity_merge_bio(struct request_queue *, struct request *, 1507 struct bio *); 1508 1509 static inline 1510 struct blk_integrity *bdev_get_integrity(struct block_device *bdev) 1511 { 1512 return bdev->bd_disk->integrity; 1513 } 1514 1515 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk) 1516 { 1517 return disk->integrity; 1518 } 1519 1520 static inline int blk_integrity_rq(struct request *rq) 1521 { 1522 if (rq->bio == NULL) 1523 return 0; 1524 1525 return bio_integrity(rq->bio); 1526 } 1527 1528 static inline void blk_queue_max_integrity_segments(struct request_queue *q, 1529 unsigned int segs) 1530 { 1531 q->limits.max_integrity_segments = segs; 1532 } 1533 1534 static inline unsigned short 1535 queue_max_integrity_segments(struct request_queue *q) 1536 { 1537 return q->limits.max_integrity_segments; 1538 } 1539 1540 #else /* CONFIG_BLK_DEV_INTEGRITY */ 1541 1542 struct bio; 1543 struct block_device; 1544 struct gendisk; 1545 struct blk_integrity; 1546 1547 static inline int blk_integrity_rq(struct request *rq) 1548 { 1549 return 0; 1550 } 1551 static inline int blk_rq_count_integrity_sg(struct request_queue *q, 1552 struct bio *b) 1553 { 1554 return 0; 1555 } 1556 static inline int blk_rq_map_integrity_sg(struct request_queue *q, 1557 struct bio *b, 1558 struct scatterlist *s) 1559 { 1560 return 0; 1561 } 1562 static inline struct blk_integrity *bdev_get_integrity(struct block_device *b) 1563 { 1564 return 0; 1565 } 1566 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk) 1567 { 1568 return NULL; 1569 } 1570 static inline int blk_integrity_compare(struct gendisk *a, struct gendisk *b) 1571 { 1572 return 0; 1573 } 1574 static inline int blk_integrity_register(struct gendisk *d, 1575 struct blk_integrity *b) 1576 { 1577 return 0; 1578 } 1579 static inline void blk_integrity_unregister(struct gendisk *d) 1580 { 1581 } 1582 static inline void blk_queue_max_integrity_segments(struct request_queue *q, 1583 unsigned int segs) 1584 { 1585 } 1586 static inline unsigned short queue_max_integrity_segments(struct request_queue *q) 1587 { 1588 return 0; 1589 } 1590 static inline int blk_integrity_merge_rq(struct request_queue *rq, 1591 struct request *r1, 1592 struct request *r2) 1593 { 1594 return 0; 1595 } 1596 static inline int blk_integrity_merge_bio(struct request_queue *rq, 1597 struct request *r, 1598 struct bio *b) 1599 { 1600 return 0; 1601 } 1602 static inline bool blk_integrity_is_initialized(struct gendisk *g) 1603 { 1604 return 0; 1605 } 1606 1607 #endif /* CONFIG_BLK_DEV_INTEGRITY */ 1608 1609 struct block_device_operations { 1610 int (*open) (struct block_device *, fmode_t); 1611 void (*release) (struct gendisk *, fmode_t); 1612 int (*rw_page)(struct block_device *, sector_t, struct page *, int rw); 1613 int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long); 1614 int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long); 1615 int (*direct_access) (struct block_device *, sector_t, 1616 void **, unsigned long *); 1617 unsigned int (*check_events) (struct gendisk *disk, 1618 unsigned int clearing); 1619 /* ->media_changed() is DEPRECATED, use ->check_events() instead */ 1620 int (*media_changed) (struct gendisk *); 1621 void (*unlock_native_capacity) (struct gendisk *); 1622 int (*revalidate_disk) (struct gendisk *); 1623 int (*getgeo)(struct block_device *, struct hd_geometry *); 1624 /* this callback is with swap_lock and sometimes page table lock held */ 1625 void (*swap_slot_free_notify) (struct block_device *, unsigned long); 1626 struct module *owner; 1627 }; 1628 1629 extern int __blkdev_driver_ioctl(struct block_device *, fmode_t, unsigned int, 1630 unsigned long); 1631 extern int bdev_read_page(struct block_device *, sector_t, struct page *); 1632 extern int bdev_write_page(struct block_device *, sector_t, struct page *, 1633 struct writeback_control *); 1634 #else /* CONFIG_BLOCK */ 1635 1636 struct block_device; 1637 1638 /* 1639 * stubs for when the block layer is configured out 1640 */ 1641 #define buffer_heads_over_limit 0 1642 1643 static inline long nr_blockdev_pages(void) 1644 { 1645 return 0; 1646 } 1647 1648 struct blk_plug { 1649 }; 1650 1651 static inline void blk_start_plug(struct blk_plug *plug) 1652 { 1653 } 1654 1655 static inline void blk_finish_plug(struct blk_plug *plug) 1656 { 1657 } 1658 1659 static inline void blk_flush_plug(struct task_struct *task) 1660 { 1661 } 1662 1663 static inline void blk_schedule_flush_plug(struct task_struct *task) 1664 { 1665 } 1666 1667 1668 static inline bool blk_needs_flush_plug(struct task_struct *tsk) 1669 { 1670 return false; 1671 } 1672 1673 static inline int blkdev_issue_flush(struct block_device *bdev, gfp_t gfp_mask, 1674 sector_t *error_sector) 1675 { 1676 return 0; 1677 } 1678 1679 #endif /* CONFIG_BLOCK */ 1680 1681 #endif 1682