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 #include <linux/percpu-refcount.h> 25 26 #include <asm/scatterlist.h> 27 28 struct module; 29 struct scsi_ioctl_command; 30 31 struct request_queue; 32 struct elevator_queue; 33 struct request_pm_state; 34 struct blk_trace; 35 struct request; 36 struct sg_io_hdr; 37 struct bsg_job; 38 struct blkcg_gq; 39 struct blk_flush_queue; 40 41 #define BLKDEV_MIN_RQ 4 42 #define BLKDEV_MAX_RQ 128 /* Default maximum */ 43 44 /* 45 * Maximum number of blkcg policies allowed to be registered concurrently. 46 * Defined here to simplify include dependency. 47 */ 48 #define BLKCG_MAX_POLS 2 49 50 struct request; 51 typedef void (rq_end_io_fn)(struct request *, int); 52 53 #define BLK_RL_SYNCFULL (1U << 0) 54 #define BLK_RL_ASYNCFULL (1U << 1) 55 56 struct request_list { 57 struct request_queue *q; /* the queue this rl belongs to */ 58 #ifdef CONFIG_BLK_CGROUP 59 struct blkcg_gq *blkg; /* blkg this request pool belongs to */ 60 #endif 61 /* 62 * count[], starved[], and wait[] are indexed by 63 * BLK_RW_SYNC/BLK_RW_ASYNC 64 */ 65 int count[2]; 66 int starved[2]; 67 mempool_t *rq_pool; 68 wait_queue_head_t wait[2]; 69 unsigned int flags; 70 }; 71 72 /* 73 * request command types 74 */ 75 enum rq_cmd_type_bits { 76 REQ_TYPE_FS = 1, /* fs request */ 77 REQ_TYPE_BLOCK_PC, /* scsi command */ 78 REQ_TYPE_SENSE, /* sense request */ 79 REQ_TYPE_PM_SUSPEND, /* suspend request */ 80 REQ_TYPE_PM_RESUME, /* resume request */ 81 REQ_TYPE_PM_SHUTDOWN, /* shutdown request */ 82 REQ_TYPE_SPECIAL, /* driver defined type */ 83 /* 84 * for ATA/ATAPI devices. this really doesn't belong here, ide should 85 * use REQ_TYPE_SPECIAL and use rq->cmd[0] with the range of driver 86 * private REQ_LB opcodes to differentiate what type of request this is 87 */ 88 REQ_TYPE_ATA_TASKFILE, 89 REQ_TYPE_ATA_PC, 90 }; 91 92 #define BLK_MAX_CDB 16 93 94 /* 95 * Try to put the fields that are referenced together in the same cacheline. 96 * 97 * If you modify this structure, make sure to update blk_rq_init() and 98 * especially blk_mq_rq_ctx_init() to take care of the added fields. 99 */ 100 struct request { 101 struct list_head queuelist; 102 union { 103 struct call_single_data csd; 104 unsigned long fifo_time; 105 }; 106 107 struct request_queue *q; 108 struct blk_mq_ctx *mq_ctx; 109 110 u64 cmd_flags; 111 enum rq_cmd_type_bits cmd_type; 112 unsigned long atomic_flags; 113 114 int cpu; 115 116 /* the following two fields are internal, NEVER access directly */ 117 unsigned int __data_len; /* total data len */ 118 sector_t __sector; /* sector cursor */ 119 120 struct bio *bio; 121 struct bio *biotail; 122 123 /* 124 * The hash is used inside the scheduler, and killed once the 125 * request reaches the dispatch list. The ipi_list is only used 126 * to queue the request for softirq completion, which is long 127 * after the request has been unhashed (and even removed from 128 * the dispatch list). 129 */ 130 union { 131 struct hlist_node hash; /* merge hash */ 132 struct list_head ipi_list; 133 }; 134 135 /* 136 * The rb_node is only used inside the io scheduler, requests 137 * are pruned when moved to the dispatch queue. So let the 138 * completion_data share space with the rb_node. 139 */ 140 union { 141 struct rb_node rb_node; /* sort/lookup */ 142 void *completion_data; 143 }; 144 145 /* 146 * Three pointers are available for the IO schedulers, if they need 147 * more they have to dynamically allocate it. Flush requests are 148 * never put on the IO scheduler. So let the flush fields share 149 * space with the elevator data. 150 */ 151 union { 152 struct { 153 struct io_cq *icq; 154 void *priv[2]; 155 } elv; 156 157 struct { 158 unsigned int seq; 159 struct list_head list; 160 rq_end_io_fn *saved_end_io; 161 } flush; 162 }; 163 164 struct gendisk *rq_disk; 165 struct hd_struct *part; 166 unsigned long start_time; 167 #ifdef CONFIG_BLK_CGROUP 168 struct request_list *rl; /* rl this rq is alloced from */ 169 unsigned long long start_time_ns; 170 unsigned long long io_start_time_ns; /* when passed to hardware */ 171 #endif 172 /* Number of scatter-gather DMA addr+len pairs after 173 * physical address coalescing is performed. 174 */ 175 unsigned short nr_phys_segments; 176 #if defined(CONFIG_BLK_DEV_INTEGRITY) 177 unsigned short nr_integrity_segments; 178 #endif 179 180 unsigned short ioprio; 181 182 void *special; /* opaque pointer available for LLD use */ 183 184 int tag; 185 int errors; 186 187 /* 188 * when request is used as a packet command carrier 189 */ 190 unsigned char __cmd[BLK_MAX_CDB]; 191 unsigned char *cmd; 192 unsigned short cmd_len; 193 194 unsigned int extra_len; /* length of alignment and padding */ 195 unsigned int sense_len; 196 unsigned int resid_len; /* residual count */ 197 void *sense; 198 199 unsigned long deadline; 200 struct list_head timeout_list; 201 unsigned int timeout; 202 int retries; 203 204 /* 205 * completion callback. 206 */ 207 rq_end_io_fn *end_io; 208 void *end_io_data; 209 210 /* for bidi */ 211 struct request *next_rq; 212 }; 213 214 static inline unsigned short req_get_ioprio(struct request *req) 215 { 216 return req->ioprio; 217 } 218 219 /* 220 * State information carried for REQ_TYPE_PM_SUSPEND and REQ_TYPE_PM_RESUME 221 * requests. Some step values could eventually be made generic. 222 */ 223 struct request_pm_state 224 { 225 /* PM state machine step value, currently driver specific */ 226 int pm_step; 227 /* requested PM state value (S1, S2, S3, S4, ...) */ 228 u32 pm_state; 229 void* data; /* for driver use */ 230 }; 231 232 #include <linux/elevator.h> 233 234 struct blk_queue_ctx; 235 236 typedef void (request_fn_proc) (struct request_queue *q); 237 typedef void (make_request_fn) (struct request_queue *q, struct bio *bio); 238 typedef int (prep_rq_fn) (struct request_queue *, struct request *); 239 typedef void (unprep_rq_fn) (struct request_queue *, struct request *); 240 241 struct bio_vec; 242 struct bvec_merge_data { 243 struct block_device *bi_bdev; 244 sector_t bi_sector; 245 unsigned bi_size; 246 unsigned long bi_rw; 247 }; 248 typedef int (merge_bvec_fn) (struct request_queue *, struct bvec_merge_data *, 249 struct bio_vec *); 250 typedef void (softirq_done_fn)(struct request *); 251 typedef int (dma_drain_needed_fn)(struct request *); 252 typedef int (lld_busy_fn) (struct request_queue *q); 253 typedef int (bsg_job_fn) (struct bsg_job *); 254 255 enum blk_eh_timer_return { 256 BLK_EH_NOT_HANDLED, 257 BLK_EH_HANDLED, 258 BLK_EH_RESET_TIMER, 259 }; 260 261 typedef enum blk_eh_timer_return (rq_timed_out_fn)(struct request *); 262 263 enum blk_queue_state { 264 Queue_down, 265 Queue_up, 266 }; 267 268 struct blk_queue_tag { 269 struct request **tag_index; /* map of busy tags */ 270 unsigned long *tag_map; /* bit map of free/busy tags */ 271 int busy; /* current depth */ 272 int max_depth; /* what we will send to device */ 273 int real_max_depth; /* what the array can hold */ 274 atomic_t refcnt; /* map can be shared */ 275 }; 276 277 #define BLK_SCSI_MAX_CMDS (256) 278 #define BLK_SCSI_CMD_PER_LONG (BLK_SCSI_MAX_CMDS / (sizeof(long) * 8)) 279 280 struct queue_limits { 281 unsigned long bounce_pfn; 282 unsigned long seg_boundary_mask; 283 284 unsigned int max_hw_sectors; 285 unsigned int chunk_sectors; 286 unsigned int max_sectors; 287 unsigned int max_segment_size; 288 unsigned int physical_block_size; 289 unsigned int alignment_offset; 290 unsigned int io_min; 291 unsigned int io_opt; 292 unsigned int max_discard_sectors; 293 unsigned int max_write_same_sectors; 294 unsigned int discard_granularity; 295 unsigned int discard_alignment; 296 297 unsigned short logical_block_size; 298 unsigned short max_segments; 299 unsigned short max_integrity_segments; 300 301 unsigned char misaligned; 302 unsigned char discard_misaligned; 303 unsigned char cluster; 304 unsigned char discard_zeroes_data; 305 unsigned char raid_partial_stripes_expensive; 306 }; 307 308 struct request_queue { 309 /* 310 * Together with queue_head for cacheline sharing 311 */ 312 struct list_head queue_head; 313 struct request *last_merge; 314 struct elevator_queue *elevator; 315 int nr_rqs[2]; /* # allocated [a]sync rqs */ 316 int nr_rqs_elvpriv; /* # allocated rqs w/ elvpriv */ 317 318 /* 319 * If blkcg is not used, @q->root_rl serves all requests. If blkcg 320 * is used, root blkg allocates from @q->root_rl and all other 321 * blkgs from their own blkg->rl. Which one to use should be 322 * determined using bio_request_list(). 323 */ 324 struct request_list root_rl; 325 326 request_fn_proc *request_fn; 327 make_request_fn *make_request_fn; 328 prep_rq_fn *prep_rq_fn; 329 unprep_rq_fn *unprep_rq_fn; 330 merge_bvec_fn *merge_bvec_fn; 331 softirq_done_fn *softirq_done_fn; 332 rq_timed_out_fn *rq_timed_out_fn; 333 dma_drain_needed_fn *dma_drain_needed; 334 lld_busy_fn *lld_busy_fn; 335 336 struct blk_mq_ops *mq_ops; 337 338 unsigned int *mq_map; 339 340 /* sw queues */ 341 struct blk_mq_ctx __percpu *queue_ctx; 342 unsigned int nr_queues; 343 344 /* hw dispatch queues */ 345 struct blk_mq_hw_ctx **queue_hw_ctx; 346 unsigned int nr_hw_queues; 347 348 /* 349 * Dispatch queue sorting 350 */ 351 sector_t end_sector; 352 struct request *boundary_rq; 353 354 /* 355 * Delayed queue handling 356 */ 357 struct delayed_work delay_work; 358 359 struct backing_dev_info backing_dev_info; 360 361 /* 362 * The queue owner gets to use this for whatever they like. 363 * ll_rw_blk doesn't touch it. 364 */ 365 void *queuedata; 366 367 /* 368 * various queue flags, see QUEUE_* below 369 */ 370 unsigned long queue_flags; 371 372 /* 373 * ida allocated id for this queue. Used to index queues from 374 * ioctx. 375 */ 376 int id; 377 378 /* 379 * queue needs bounce pages for pages above this limit 380 */ 381 gfp_t bounce_gfp; 382 383 /* 384 * protects queue structures from reentrancy. ->__queue_lock should 385 * _never_ be used directly, it is queue private. always use 386 * ->queue_lock. 387 */ 388 spinlock_t __queue_lock; 389 spinlock_t *queue_lock; 390 391 /* 392 * queue kobject 393 */ 394 struct kobject kobj; 395 396 /* 397 * mq queue kobject 398 */ 399 struct kobject mq_kobj; 400 401 #ifdef CONFIG_PM_RUNTIME 402 struct device *dev; 403 int rpm_status; 404 unsigned int nr_pending; 405 #endif 406 407 /* 408 * queue settings 409 */ 410 unsigned long nr_requests; /* Max # of requests */ 411 unsigned int nr_congestion_on; 412 unsigned int nr_congestion_off; 413 unsigned int nr_batching; 414 415 unsigned int dma_drain_size; 416 void *dma_drain_buffer; 417 unsigned int dma_pad_mask; 418 unsigned int dma_alignment; 419 420 struct blk_queue_tag *queue_tags; 421 struct list_head tag_busy_list; 422 423 unsigned int nr_sorted; 424 unsigned int in_flight[2]; 425 /* 426 * Number of active block driver functions for which blk_drain_queue() 427 * must wait. Must be incremented around functions that unlock the 428 * queue_lock internally, e.g. scsi_request_fn(). 429 */ 430 unsigned int request_fn_active; 431 432 unsigned int rq_timeout; 433 struct timer_list timeout; 434 struct list_head timeout_list; 435 436 struct list_head icq_list; 437 #ifdef CONFIG_BLK_CGROUP 438 DECLARE_BITMAP (blkcg_pols, BLKCG_MAX_POLS); 439 struct blkcg_gq *root_blkg; 440 struct list_head blkg_list; 441 #endif 442 443 struct queue_limits limits; 444 445 /* 446 * sg stuff 447 */ 448 unsigned int sg_timeout; 449 unsigned int sg_reserved_size; 450 int node; 451 #ifdef CONFIG_BLK_DEV_IO_TRACE 452 struct blk_trace *blk_trace; 453 #endif 454 /* 455 * for flush operations 456 */ 457 unsigned int flush_flags; 458 unsigned int flush_not_queueable:1; 459 struct blk_flush_queue *fq; 460 461 struct list_head requeue_list; 462 spinlock_t requeue_lock; 463 struct work_struct requeue_work; 464 465 struct mutex sysfs_lock; 466 467 int bypass_depth; 468 int mq_freeze_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_ref mq_usage_counter; 483 struct list_head all_q_node; 484 485 struct blk_mq_tag_set *tag_set; 486 struct list_head tag_set_list; 487 }; 488 489 #define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */ 490 #define QUEUE_FLAG_STOPPED 2 /* queue is stopped */ 491 #define QUEUE_FLAG_SYNCFULL 3 /* read queue has been filled */ 492 #define QUEUE_FLAG_ASYNCFULL 4 /* write queue has been filled */ 493 #define QUEUE_FLAG_DYING 5 /* queue being torn down */ 494 #define QUEUE_FLAG_BYPASS 6 /* act as dumb FIFO queue */ 495 #define QUEUE_FLAG_BIDI 7 /* queue supports bidi requests */ 496 #define QUEUE_FLAG_NOMERGES 8 /* disable merge attempts */ 497 #define QUEUE_FLAG_SAME_COMP 9 /* complete on same CPU-group */ 498 #define QUEUE_FLAG_FAIL_IO 10 /* fake timeout */ 499 #define QUEUE_FLAG_STACKABLE 11 /* supports request stacking */ 500 #define QUEUE_FLAG_NONROT 12 /* non-rotational device (SSD) */ 501 #define QUEUE_FLAG_VIRT QUEUE_FLAG_NONROT /* paravirt device */ 502 #define QUEUE_FLAG_IO_STAT 13 /* do IO stats */ 503 #define QUEUE_FLAG_DISCARD 14 /* supports DISCARD */ 504 #define QUEUE_FLAG_NOXMERGES 15 /* No extended merges */ 505 #define QUEUE_FLAG_ADD_RANDOM 16 /* Contributes to random pool */ 506 #define QUEUE_FLAG_SECDISCARD 17 /* supports SECDISCARD */ 507 #define QUEUE_FLAG_SAME_FORCE 18 /* force complete on same CPU */ 508 #define QUEUE_FLAG_DEAD 19 /* queue tear-down finished */ 509 #define QUEUE_FLAG_INIT_DONE 20 /* queue is initialized */ 510 #define QUEUE_FLAG_NO_SG_MERGE 21 /* don't attempt to merge SG segments*/ 511 #define QUEUE_FLAG_SG_GAPS 22 /* queue doesn't support SG gaps */ 512 513 #define QUEUE_FLAG_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \ 514 (1 << QUEUE_FLAG_STACKABLE) | \ 515 (1 << QUEUE_FLAG_SAME_COMP) | \ 516 (1 << QUEUE_FLAG_ADD_RANDOM)) 517 518 #define QUEUE_FLAG_MQ_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \ 519 (1 << QUEUE_FLAG_SAME_COMP)) 520 521 static inline void queue_lockdep_assert_held(struct request_queue *q) 522 { 523 if (q->queue_lock) 524 lockdep_assert_held(q->queue_lock); 525 } 526 527 static inline void queue_flag_set_unlocked(unsigned int flag, 528 struct request_queue *q) 529 { 530 __set_bit(flag, &q->queue_flags); 531 } 532 533 static inline int queue_flag_test_and_clear(unsigned int flag, 534 struct request_queue *q) 535 { 536 queue_lockdep_assert_held(q); 537 538 if (test_bit(flag, &q->queue_flags)) { 539 __clear_bit(flag, &q->queue_flags); 540 return 1; 541 } 542 543 return 0; 544 } 545 546 static inline int queue_flag_test_and_set(unsigned int flag, 547 struct request_queue *q) 548 { 549 queue_lockdep_assert_held(q); 550 551 if (!test_bit(flag, &q->queue_flags)) { 552 __set_bit(flag, &q->queue_flags); 553 return 0; 554 } 555 556 return 1; 557 } 558 559 static inline void queue_flag_set(unsigned int flag, struct request_queue *q) 560 { 561 queue_lockdep_assert_held(q); 562 __set_bit(flag, &q->queue_flags); 563 } 564 565 static inline void queue_flag_clear_unlocked(unsigned int flag, 566 struct request_queue *q) 567 { 568 __clear_bit(flag, &q->queue_flags); 569 } 570 571 static inline int queue_in_flight(struct request_queue *q) 572 { 573 return q->in_flight[0] + q->in_flight[1]; 574 } 575 576 static inline void queue_flag_clear(unsigned int flag, struct request_queue *q) 577 { 578 queue_lockdep_assert_held(q); 579 __clear_bit(flag, &q->queue_flags); 580 } 581 582 #define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags) 583 #define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags) 584 #define blk_queue_dying(q) test_bit(QUEUE_FLAG_DYING, &(q)->queue_flags) 585 #define blk_queue_dead(q) test_bit(QUEUE_FLAG_DEAD, &(q)->queue_flags) 586 #define blk_queue_bypass(q) test_bit(QUEUE_FLAG_BYPASS, &(q)->queue_flags) 587 #define blk_queue_init_done(q) test_bit(QUEUE_FLAG_INIT_DONE, &(q)->queue_flags) 588 #define blk_queue_nomerges(q) test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags) 589 #define blk_queue_noxmerges(q) \ 590 test_bit(QUEUE_FLAG_NOXMERGES, &(q)->queue_flags) 591 #define blk_queue_nonrot(q) test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags) 592 #define blk_queue_io_stat(q) test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags) 593 #define blk_queue_add_random(q) test_bit(QUEUE_FLAG_ADD_RANDOM, &(q)->queue_flags) 594 #define blk_queue_stackable(q) \ 595 test_bit(QUEUE_FLAG_STACKABLE, &(q)->queue_flags) 596 #define blk_queue_discard(q) test_bit(QUEUE_FLAG_DISCARD, &(q)->queue_flags) 597 #define blk_queue_secdiscard(q) (blk_queue_discard(q) && \ 598 test_bit(QUEUE_FLAG_SECDISCARD, &(q)->queue_flags)) 599 600 #define blk_noretry_request(rq) \ 601 ((rq)->cmd_flags & (REQ_FAILFAST_DEV|REQ_FAILFAST_TRANSPORT| \ 602 REQ_FAILFAST_DRIVER)) 603 604 #define blk_account_rq(rq) \ 605 (((rq)->cmd_flags & REQ_STARTED) && \ 606 ((rq)->cmd_type == REQ_TYPE_FS)) 607 608 #define blk_pm_request(rq) \ 609 ((rq)->cmd_type == REQ_TYPE_PM_SUSPEND || \ 610 (rq)->cmd_type == REQ_TYPE_PM_RESUME) 611 612 #define blk_rq_cpu_valid(rq) ((rq)->cpu != -1) 613 #define blk_bidi_rq(rq) ((rq)->next_rq != NULL) 614 /* rq->queuelist of dequeued request must be list_empty() */ 615 #define blk_queued_rq(rq) (!list_empty(&(rq)->queuelist)) 616 617 #define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist) 618 619 #define rq_data_dir(rq) (((rq)->cmd_flags & 1) != 0) 620 621 /* 622 * Driver can handle struct request, if it either has an old style 623 * request_fn defined, or is blk-mq based. 624 */ 625 static inline bool queue_is_rq_based(struct request_queue *q) 626 { 627 return q->request_fn || q->mq_ops; 628 } 629 630 static inline unsigned int blk_queue_cluster(struct request_queue *q) 631 { 632 return q->limits.cluster; 633 } 634 635 /* 636 * We regard a request as sync, if either a read or a sync write 637 */ 638 static inline bool rw_is_sync(unsigned int rw_flags) 639 { 640 return !(rw_flags & REQ_WRITE) || (rw_flags & REQ_SYNC); 641 } 642 643 static inline bool rq_is_sync(struct request *rq) 644 { 645 return rw_is_sync(rq->cmd_flags); 646 } 647 648 static inline bool blk_rl_full(struct request_list *rl, bool sync) 649 { 650 unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL; 651 652 return rl->flags & flag; 653 } 654 655 static inline void blk_set_rl_full(struct request_list *rl, bool sync) 656 { 657 unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL; 658 659 rl->flags |= flag; 660 } 661 662 static inline void blk_clear_rl_full(struct request_list *rl, bool sync) 663 { 664 unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL; 665 666 rl->flags &= ~flag; 667 } 668 669 static inline bool rq_mergeable(struct request *rq) 670 { 671 if (rq->cmd_type != REQ_TYPE_FS) 672 return false; 673 674 if (rq->cmd_flags & REQ_NOMERGE_FLAGS) 675 return false; 676 677 return true; 678 } 679 680 static inline bool blk_check_merge_flags(unsigned int flags1, 681 unsigned int flags2) 682 { 683 if ((flags1 & REQ_DISCARD) != (flags2 & REQ_DISCARD)) 684 return false; 685 686 if ((flags1 & REQ_SECURE) != (flags2 & REQ_SECURE)) 687 return false; 688 689 if ((flags1 & REQ_WRITE_SAME) != (flags2 & REQ_WRITE_SAME)) 690 return false; 691 692 return true; 693 } 694 695 static inline bool blk_write_same_mergeable(struct bio *a, struct bio *b) 696 { 697 if (bio_data(a) == bio_data(b)) 698 return true; 699 700 return false; 701 } 702 703 /* 704 * q->prep_rq_fn return values 705 */ 706 #define BLKPREP_OK 0 /* serve it */ 707 #define BLKPREP_KILL 1 /* fatal error, kill */ 708 #define BLKPREP_DEFER 2 /* leave on queue */ 709 710 extern unsigned long blk_max_low_pfn, blk_max_pfn; 711 712 /* 713 * standard bounce addresses: 714 * 715 * BLK_BOUNCE_HIGH : bounce all highmem pages 716 * BLK_BOUNCE_ANY : don't bounce anything 717 * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary 718 */ 719 720 #if BITS_PER_LONG == 32 721 #define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT) 722 #else 723 #define BLK_BOUNCE_HIGH -1ULL 724 #endif 725 #define BLK_BOUNCE_ANY (-1ULL) 726 #define BLK_BOUNCE_ISA (DMA_BIT_MASK(24)) 727 728 /* 729 * default timeout for SG_IO if none specified 730 */ 731 #define BLK_DEFAULT_SG_TIMEOUT (60 * HZ) 732 #define BLK_MIN_SG_TIMEOUT (7 * HZ) 733 734 #ifdef CONFIG_BOUNCE 735 extern int init_emergency_isa_pool(void); 736 extern void blk_queue_bounce(struct request_queue *q, struct bio **bio); 737 #else 738 static inline int init_emergency_isa_pool(void) 739 { 740 return 0; 741 } 742 static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio) 743 { 744 } 745 #endif /* CONFIG_MMU */ 746 747 struct rq_map_data { 748 struct page **pages; 749 int page_order; 750 int nr_entries; 751 unsigned long offset; 752 int null_mapped; 753 int from_user; 754 }; 755 756 struct req_iterator { 757 struct bvec_iter iter; 758 struct bio *bio; 759 }; 760 761 /* This should not be used directly - use rq_for_each_segment */ 762 #define for_each_bio(_bio) \ 763 for (; _bio; _bio = _bio->bi_next) 764 #define __rq_for_each_bio(_bio, rq) \ 765 if ((rq->bio)) \ 766 for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next) 767 768 #define rq_for_each_segment(bvl, _rq, _iter) \ 769 __rq_for_each_bio(_iter.bio, _rq) \ 770 bio_for_each_segment(bvl, _iter.bio, _iter.iter) 771 772 #define rq_iter_last(bvec, _iter) \ 773 (_iter.bio->bi_next == NULL && \ 774 bio_iter_last(bvec, _iter.iter)) 775 776 #ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 777 # error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform" 778 #endif 779 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 780 extern void rq_flush_dcache_pages(struct request *rq); 781 #else 782 static inline void rq_flush_dcache_pages(struct request *rq) 783 { 784 } 785 #endif 786 787 extern int blk_register_queue(struct gendisk *disk); 788 extern void blk_unregister_queue(struct gendisk *disk); 789 extern void generic_make_request(struct bio *bio); 790 extern void blk_rq_init(struct request_queue *q, struct request *rq); 791 extern void blk_put_request(struct request *); 792 extern void __blk_put_request(struct request_queue *, struct request *); 793 extern struct request *blk_get_request(struct request_queue *, int, gfp_t); 794 extern struct request *blk_make_request(struct request_queue *, struct bio *, 795 gfp_t); 796 extern void blk_rq_set_block_pc(struct request *); 797 extern void blk_requeue_request(struct request_queue *, struct request *); 798 extern void blk_add_request_payload(struct request *rq, struct page *page, 799 unsigned int len); 800 extern int blk_rq_check_limits(struct request_queue *q, struct request *rq); 801 extern int blk_lld_busy(struct request_queue *q); 802 extern int blk_rq_prep_clone(struct request *rq, struct request *rq_src, 803 struct bio_set *bs, gfp_t gfp_mask, 804 int (*bio_ctr)(struct bio *, struct bio *, void *), 805 void *data); 806 extern void blk_rq_unprep_clone(struct request *rq); 807 extern int blk_insert_cloned_request(struct request_queue *q, 808 struct request *rq); 809 extern void blk_delay_queue(struct request_queue *, unsigned long); 810 extern void blk_recount_segments(struct request_queue *, struct bio *); 811 extern int scsi_verify_blk_ioctl(struct block_device *, unsigned int); 812 extern int scsi_cmd_blk_ioctl(struct block_device *, fmode_t, 813 unsigned int, void __user *); 814 extern int scsi_cmd_ioctl(struct request_queue *, struct gendisk *, fmode_t, 815 unsigned int, void __user *); 816 extern int sg_scsi_ioctl(struct request_queue *, struct gendisk *, fmode_t, 817 struct scsi_ioctl_command __user *); 818 819 extern void blk_queue_bio(struct request_queue *q, struct bio *bio); 820 821 /* 822 * A queue has just exitted congestion. Note this in the global counter of 823 * congested queues, and wake up anyone who was waiting for requests to be 824 * put back. 825 */ 826 static inline void blk_clear_queue_congested(struct request_queue *q, int sync) 827 { 828 clear_bdi_congested(&q->backing_dev_info, sync); 829 } 830 831 /* 832 * A queue has just entered congestion. Flag that in the queue's VM-visible 833 * state flags and increment the global gounter of congested queues. 834 */ 835 static inline void blk_set_queue_congested(struct request_queue *q, int sync) 836 { 837 set_bdi_congested(&q->backing_dev_info, sync); 838 } 839 840 extern void blk_start_queue(struct request_queue *q); 841 extern void blk_stop_queue(struct request_queue *q); 842 extern void blk_sync_queue(struct request_queue *q); 843 extern void __blk_stop_queue(struct request_queue *q); 844 extern void __blk_run_queue(struct request_queue *q); 845 extern void blk_run_queue(struct request_queue *); 846 extern void blk_run_queue_async(struct request_queue *q); 847 extern int blk_rq_map_user(struct request_queue *, struct request *, 848 struct rq_map_data *, void __user *, unsigned long, 849 gfp_t); 850 extern int blk_rq_unmap_user(struct bio *); 851 extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, unsigned int, gfp_t); 852 extern int blk_rq_map_user_iov(struct request_queue *, struct request *, 853 struct rq_map_data *, const struct sg_iovec *, 854 int, unsigned int, gfp_t); 855 extern int blk_execute_rq(struct request_queue *, struct gendisk *, 856 struct request *, int); 857 extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *, 858 struct request *, int, rq_end_io_fn *); 859 860 static inline struct request_queue *bdev_get_queue(struct block_device *bdev) 861 { 862 return bdev->bd_disk->queue; /* this is never NULL */ 863 } 864 865 /* 866 * blk_rq_pos() : the current sector 867 * blk_rq_bytes() : bytes left in the entire request 868 * blk_rq_cur_bytes() : bytes left in the current segment 869 * blk_rq_err_bytes() : bytes left till the next error boundary 870 * blk_rq_sectors() : sectors left in the entire request 871 * blk_rq_cur_sectors() : sectors left in the current segment 872 */ 873 static inline sector_t blk_rq_pos(const struct request *rq) 874 { 875 return rq->__sector; 876 } 877 878 static inline unsigned int blk_rq_bytes(const struct request *rq) 879 { 880 return rq->__data_len; 881 } 882 883 static inline int blk_rq_cur_bytes(const struct request *rq) 884 { 885 return rq->bio ? bio_cur_bytes(rq->bio) : 0; 886 } 887 888 extern unsigned int blk_rq_err_bytes(const struct request *rq); 889 890 static inline unsigned int blk_rq_sectors(const struct request *rq) 891 { 892 return blk_rq_bytes(rq) >> 9; 893 } 894 895 static inline unsigned int blk_rq_cur_sectors(const struct request *rq) 896 { 897 return blk_rq_cur_bytes(rq) >> 9; 898 } 899 900 static inline unsigned int blk_queue_get_max_sectors(struct request_queue *q, 901 unsigned int cmd_flags) 902 { 903 if (unlikely(cmd_flags & REQ_DISCARD)) 904 return min(q->limits.max_discard_sectors, UINT_MAX >> 9); 905 906 if (unlikely(cmd_flags & REQ_WRITE_SAME)) 907 return q->limits.max_write_same_sectors; 908 909 return q->limits.max_sectors; 910 } 911 912 /* 913 * Return maximum size of a request at given offset. Only valid for 914 * file system requests. 915 */ 916 static inline unsigned int blk_max_size_offset(struct request_queue *q, 917 sector_t offset) 918 { 919 if (!q->limits.chunk_sectors) 920 return q->limits.max_sectors; 921 922 return q->limits.chunk_sectors - 923 (offset & (q->limits.chunk_sectors - 1)); 924 } 925 926 static inline unsigned int blk_rq_get_max_sectors(struct request *rq) 927 { 928 struct request_queue *q = rq->q; 929 930 if (unlikely(rq->cmd_type == REQ_TYPE_BLOCK_PC)) 931 return q->limits.max_hw_sectors; 932 933 if (!q->limits.chunk_sectors) 934 return blk_queue_get_max_sectors(q, rq->cmd_flags); 935 936 return min(blk_max_size_offset(q, blk_rq_pos(rq)), 937 blk_queue_get_max_sectors(q, rq->cmd_flags)); 938 } 939 940 static inline unsigned int blk_rq_count_bios(struct request *rq) 941 { 942 unsigned int nr_bios = 0; 943 struct bio *bio; 944 945 __rq_for_each_bio(bio, rq) 946 nr_bios++; 947 948 return nr_bios; 949 } 950 951 /* 952 * Request issue related functions. 953 */ 954 extern struct request *blk_peek_request(struct request_queue *q); 955 extern void blk_start_request(struct request *rq); 956 extern struct request *blk_fetch_request(struct request_queue *q); 957 958 /* 959 * Request completion related functions. 960 * 961 * blk_update_request() completes given number of bytes and updates 962 * the request without completing it. 963 * 964 * blk_end_request() and friends. __blk_end_request() must be called 965 * with the request queue spinlock acquired. 966 * 967 * Several drivers define their own end_request and call 968 * blk_end_request() for parts of the original function. 969 * This prevents code duplication in drivers. 970 */ 971 extern bool blk_update_request(struct request *rq, int error, 972 unsigned int nr_bytes); 973 extern void blk_finish_request(struct request *rq, int error); 974 extern bool blk_end_request(struct request *rq, int error, 975 unsigned int nr_bytes); 976 extern void blk_end_request_all(struct request *rq, int error); 977 extern bool blk_end_request_cur(struct request *rq, int error); 978 extern bool blk_end_request_err(struct request *rq, int error); 979 extern bool __blk_end_request(struct request *rq, int error, 980 unsigned int nr_bytes); 981 extern void __blk_end_request_all(struct request *rq, int error); 982 extern bool __blk_end_request_cur(struct request *rq, int error); 983 extern bool __blk_end_request_err(struct request *rq, int error); 984 985 extern void blk_complete_request(struct request *); 986 extern void __blk_complete_request(struct request *); 987 extern void blk_abort_request(struct request *); 988 extern void blk_unprep_request(struct request *); 989 990 /* 991 * Access functions for manipulating queue properties 992 */ 993 extern struct request_queue *blk_init_queue_node(request_fn_proc *rfn, 994 spinlock_t *lock, int node_id); 995 extern struct request_queue *blk_init_queue(request_fn_proc *, spinlock_t *); 996 extern struct request_queue *blk_init_allocated_queue(struct request_queue *, 997 request_fn_proc *, spinlock_t *); 998 extern void blk_cleanup_queue(struct request_queue *); 999 extern void blk_queue_make_request(struct request_queue *, make_request_fn *); 1000 extern void blk_queue_bounce_limit(struct request_queue *, u64); 1001 extern void blk_limits_max_hw_sectors(struct queue_limits *, unsigned int); 1002 extern void blk_queue_max_hw_sectors(struct request_queue *, unsigned int); 1003 extern void blk_queue_chunk_sectors(struct request_queue *, unsigned int); 1004 extern void blk_queue_max_segments(struct request_queue *, unsigned short); 1005 extern void blk_queue_max_segment_size(struct request_queue *, unsigned int); 1006 extern void blk_queue_max_discard_sectors(struct request_queue *q, 1007 unsigned int max_discard_sectors); 1008 extern void blk_queue_max_write_same_sectors(struct request_queue *q, 1009 unsigned int max_write_same_sectors); 1010 extern void blk_queue_logical_block_size(struct request_queue *, unsigned short); 1011 extern void blk_queue_physical_block_size(struct request_queue *, unsigned int); 1012 extern void blk_queue_alignment_offset(struct request_queue *q, 1013 unsigned int alignment); 1014 extern void blk_limits_io_min(struct queue_limits *limits, unsigned int min); 1015 extern void blk_queue_io_min(struct request_queue *q, unsigned int min); 1016 extern void blk_limits_io_opt(struct queue_limits *limits, unsigned int opt); 1017 extern void blk_queue_io_opt(struct request_queue *q, unsigned int opt); 1018 extern void blk_set_default_limits(struct queue_limits *lim); 1019 extern void blk_set_stacking_limits(struct queue_limits *lim); 1020 extern int blk_stack_limits(struct queue_limits *t, struct queue_limits *b, 1021 sector_t offset); 1022 extern int bdev_stack_limits(struct queue_limits *t, struct block_device *bdev, 1023 sector_t offset); 1024 extern void disk_stack_limits(struct gendisk *disk, struct block_device *bdev, 1025 sector_t offset); 1026 extern void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b); 1027 extern void blk_queue_dma_pad(struct request_queue *, unsigned int); 1028 extern void blk_queue_update_dma_pad(struct request_queue *, unsigned int); 1029 extern int blk_queue_dma_drain(struct request_queue *q, 1030 dma_drain_needed_fn *dma_drain_needed, 1031 void *buf, unsigned int size); 1032 extern void blk_queue_lld_busy(struct request_queue *q, lld_busy_fn *fn); 1033 extern void blk_queue_segment_boundary(struct request_queue *, unsigned long); 1034 extern void blk_queue_prep_rq(struct request_queue *, prep_rq_fn *pfn); 1035 extern void blk_queue_unprep_rq(struct request_queue *, unprep_rq_fn *ufn); 1036 extern void blk_queue_merge_bvec(struct request_queue *, merge_bvec_fn *); 1037 extern void blk_queue_dma_alignment(struct request_queue *, int); 1038 extern void blk_queue_update_dma_alignment(struct request_queue *, int); 1039 extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *); 1040 extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *); 1041 extern void blk_queue_rq_timeout(struct request_queue *, unsigned int); 1042 extern void blk_queue_flush(struct request_queue *q, unsigned int flush); 1043 extern void blk_queue_flush_queueable(struct request_queue *q, bool queueable); 1044 extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev); 1045 1046 extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *); 1047 extern int blk_bio_map_sg(struct request_queue *q, struct bio *bio, 1048 struct scatterlist *sglist); 1049 extern void blk_dump_rq_flags(struct request *, char *); 1050 extern long nr_blockdev_pages(void); 1051 1052 bool __must_check blk_get_queue(struct request_queue *); 1053 struct request_queue *blk_alloc_queue(gfp_t); 1054 struct request_queue *blk_alloc_queue_node(gfp_t, int); 1055 extern void blk_put_queue(struct request_queue *); 1056 1057 /* 1058 * block layer runtime pm functions 1059 */ 1060 #ifdef CONFIG_PM_RUNTIME 1061 extern void blk_pm_runtime_init(struct request_queue *q, struct device *dev); 1062 extern int blk_pre_runtime_suspend(struct request_queue *q); 1063 extern void blk_post_runtime_suspend(struct request_queue *q, int err); 1064 extern void blk_pre_runtime_resume(struct request_queue *q); 1065 extern void blk_post_runtime_resume(struct request_queue *q, int err); 1066 #else 1067 static inline void blk_pm_runtime_init(struct request_queue *q, 1068 struct device *dev) {} 1069 static inline int blk_pre_runtime_suspend(struct request_queue *q) 1070 { 1071 return -ENOSYS; 1072 } 1073 static inline void blk_post_runtime_suspend(struct request_queue *q, int err) {} 1074 static inline void blk_pre_runtime_resume(struct request_queue *q) {} 1075 static inline void blk_post_runtime_resume(struct request_queue *q, int err) {} 1076 #endif 1077 1078 /* 1079 * blk_plug permits building a queue of related requests by holding the I/O 1080 * fragments for a short period. This allows merging of sequential requests 1081 * into single larger request. As the requests are moved from a per-task list to 1082 * the device's request_queue in a batch, this results in improved scalability 1083 * as the lock contention for request_queue lock is reduced. 1084 * 1085 * It is ok not to disable preemption when adding the request to the plug list 1086 * or when attempting a merge, because blk_schedule_flush_list() will only flush 1087 * the plug list when the task sleeps by itself. For details, please see 1088 * schedule() where blk_schedule_flush_plug() is called. 1089 */ 1090 struct blk_plug { 1091 struct list_head list; /* requests */ 1092 struct list_head mq_list; /* blk-mq requests */ 1093 struct list_head cb_list; /* md requires an unplug callback */ 1094 }; 1095 #define BLK_MAX_REQUEST_COUNT 16 1096 1097 struct blk_plug_cb; 1098 typedef void (*blk_plug_cb_fn)(struct blk_plug_cb *, bool); 1099 struct blk_plug_cb { 1100 struct list_head list; 1101 blk_plug_cb_fn callback; 1102 void *data; 1103 }; 1104 extern struct blk_plug_cb *blk_check_plugged(blk_plug_cb_fn unplug, 1105 void *data, int size); 1106 extern void blk_start_plug(struct blk_plug *); 1107 extern void blk_finish_plug(struct blk_plug *); 1108 extern void blk_flush_plug_list(struct blk_plug *, bool); 1109 1110 static inline void blk_flush_plug(struct task_struct *tsk) 1111 { 1112 struct blk_plug *plug = tsk->plug; 1113 1114 if (plug) 1115 blk_flush_plug_list(plug, false); 1116 } 1117 1118 static inline void blk_schedule_flush_plug(struct task_struct *tsk) 1119 { 1120 struct blk_plug *plug = tsk->plug; 1121 1122 if (plug) 1123 blk_flush_plug_list(plug, true); 1124 } 1125 1126 static inline bool blk_needs_flush_plug(struct task_struct *tsk) 1127 { 1128 struct blk_plug *plug = tsk->plug; 1129 1130 return plug && 1131 (!list_empty(&plug->list) || 1132 !list_empty(&plug->mq_list) || 1133 !list_empty(&plug->cb_list)); 1134 } 1135 1136 /* 1137 * tag stuff 1138 */ 1139 #define blk_rq_tagged(rq) ((rq)->cmd_flags & REQ_QUEUED) 1140 extern int blk_queue_start_tag(struct request_queue *, struct request *); 1141 extern struct request *blk_queue_find_tag(struct request_queue *, int); 1142 extern void blk_queue_end_tag(struct request_queue *, struct request *); 1143 extern int blk_queue_init_tags(struct request_queue *, int, struct blk_queue_tag *); 1144 extern void blk_queue_free_tags(struct request_queue *); 1145 extern int blk_queue_resize_tags(struct request_queue *, int); 1146 extern void blk_queue_invalidate_tags(struct request_queue *); 1147 extern struct blk_queue_tag *blk_init_tags(int); 1148 extern void blk_free_tags(struct blk_queue_tag *); 1149 1150 static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt, 1151 int tag) 1152 { 1153 if (unlikely(bqt == NULL || tag >= bqt->real_max_depth)) 1154 return NULL; 1155 return bqt->tag_index[tag]; 1156 } 1157 1158 #define BLKDEV_DISCARD_SECURE 0x01 /* secure discard */ 1159 1160 extern int blkdev_issue_flush(struct block_device *, gfp_t, sector_t *); 1161 extern int blkdev_issue_discard(struct block_device *bdev, sector_t sector, 1162 sector_t nr_sects, gfp_t gfp_mask, unsigned long flags); 1163 extern int blkdev_issue_write_same(struct block_device *bdev, sector_t sector, 1164 sector_t nr_sects, gfp_t gfp_mask, struct page *page); 1165 extern int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector, 1166 sector_t nr_sects, gfp_t gfp_mask); 1167 static inline int sb_issue_discard(struct super_block *sb, sector_t block, 1168 sector_t nr_blocks, gfp_t gfp_mask, unsigned long flags) 1169 { 1170 return blkdev_issue_discard(sb->s_bdev, block << (sb->s_blocksize_bits - 9), 1171 nr_blocks << (sb->s_blocksize_bits - 9), 1172 gfp_mask, flags); 1173 } 1174 static inline int sb_issue_zeroout(struct super_block *sb, sector_t block, 1175 sector_t nr_blocks, gfp_t gfp_mask) 1176 { 1177 return blkdev_issue_zeroout(sb->s_bdev, 1178 block << (sb->s_blocksize_bits - 9), 1179 nr_blocks << (sb->s_blocksize_bits - 9), 1180 gfp_mask); 1181 } 1182 1183 extern int blk_verify_command(unsigned char *cmd, fmode_t has_write_perm); 1184 1185 enum blk_default_limits { 1186 BLK_MAX_SEGMENTS = 128, 1187 BLK_SAFE_MAX_SECTORS = 255, 1188 BLK_DEF_MAX_SECTORS = 1024, 1189 BLK_MAX_SEGMENT_SIZE = 65536, 1190 BLK_SEG_BOUNDARY_MASK = 0xFFFFFFFFUL, 1191 }; 1192 1193 #define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist) 1194 1195 static inline unsigned long queue_bounce_pfn(struct request_queue *q) 1196 { 1197 return q->limits.bounce_pfn; 1198 } 1199 1200 static inline unsigned long queue_segment_boundary(struct request_queue *q) 1201 { 1202 return q->limits.seg_boundary_mask; 1203 } 1204 1205 static inline unsigned int queue_max_sectors(struct request_queue *q) 1206 { 1207 return q->limits.max_sectors; 1208 } 1209 1210 static inline unsigned int queue_max_hw_sectors(struct request_queue *q) 1211 { 1212 return q->limits.max_hw_sectors; 1213 } 1214 1215 static inline unsigned short queue_max_segments(struct request_queue *q) 1216 { 1217 return q->limits.max_segments; 1218 } 1219 1220 static inline unsigned int queue_max_segment_size(struct request_queue *q) 1221 { 1222 return q->limits.max_segment_size; 1223 } 1224 1225 static inline unsigned short queue_logical_block_size(struct request_queue *q) 1226 { 1227 int retval = 512; 1228 1229 if (q && q->limits.logical_block_size) 1230 retval = q->limits.logical_block_size; 1231 1232 return retval; 1233 } 1234 1235 static inline unsigned short bdev_logical_block_size(struct block_device *bdev) 1236 { 1237 return queue_logical_block_size(bdev_get_queue(bdev)); 1238 } 1239 1240 static inline unsigned int queue_physical_block_size(struct request_queue *q) 1241 { 1242 return q->limits.physical_block_size; 1243 } 1244 1245 static inline unsigned int bdev_physical_block_size(struct block_device *bdev) 1246 { 1247 return queue_physical_block_size(bdev_get_queue(bdev)); 1248 } 1249 1250 static inline unsigned int queue_io_min(struct request_queue *q) 1251 { 1252 return q->limits.io_min; 1253 } 1254 1255 static inline int bdev_io_min(struct block_device *bdev) 1256 { 1257 return queue_io_min(bdev_get_queue(bdev)); 1258 } 1259 1260 static inline unsigned int queue_io_opt(struct request_queue *q) 1261 { 1262 return q->limits.io_opt; 1263 } 1264 1265 static inline int bdev_io_opt(struct block_device *bdev) 1266 { 1267 return queue_io_opt(bdev_get_queue(bdev)); 1268 } 1269 1270 static inline int queue_alignment_offset(struct request_queue *q) 1271 { 1272 if (q->limits.misaligned) 1273 return -1; 1274 1275 return q->limits.alignment_offset; 1276 } 1277 1278 static inline int queue_limit_alignment_offset(struct queue_limits *lim, sector_t sector) 1279 { 1280 unsigned int granularity = max(lim->physical_block_size, lim->io_min); 1281 unsigned int alignment = sector_div(sector, granularity >> 9) << 9; 1282 1283 return (granularity + lim->alignment_offset - alignment) % granularity; 1284 } 1285 1286 static inline int bdev_alignment_offset(struct block_device *bdev) 1287 { 1288 struct request_queue *q = bdev_get_queue(bdev); 1289 1290 if (q->limits.misaligned) 1291 return -1; 1292 1293 if (bdev != bdev->bd_contains) 1294 return bdev->bd_part->alignment_offset; 1295 1296 return q->limits.alignment_offset; 1297 } 1298 1299 static inline int queue_discard_alignment(struct request_queue *q) 1300 { 1301 if (q->limits.discard_misaligned) 1302 return -1; 1303 1304 return q->limits.discard_alignment; 1305 } 1306 1307 static inline int queue_limit_discard_alignment(struct queue_limits *lim, sector_t sector) 1308 { 1309 unsigned int alignment, granularity, offset; 1310 1311 if (!lim->max_discard_sectors) 1312 return 0; 1313 1314 /* Why are these in bytes, not sectors? */ 1315 alignment = lim->discard_alignment >> 9; 1316 granularity = lim->discard_granularity >> 9; 1317 if (!granularity) 1318 return 0; 1319 1320 /* Offset of the partition start in 'granularity' sectors */ 1321 offset = sector_div(sector, granularity); 1322 1323 /* And why do we do this modulus *again* in blkdev_issue_discard()? */ 1324 offset = (granularity + alignment - offset) % granularity; 1325 1326 /* Turn it back into bytes, gaah */ 1327 return offset << 9; 1328 } 1329 1330 static inline int bdev_discard_alignment(struct block_device *bdev) 1331 { 1332 struct request_queue *q = bdev_get_queue(bdev); 1333 1334 if (bdev != bdev->bd_contains) 1335 return bdev->bd_part->discard_alignment; 1336 1337 return q->limits.discard_alignment; 1338 } 1339 1340 static inline unsigned int queue_discard_zeroes_data(struct request_queue *q) 1341 { 1342 if (q->limits.max_discard_sectors && q->limits.discard_zeroes_data == 1) 1343 return 1; 1344 1345 return 0; 1346 } 1347 1348 static inline unsigned int bdev_discard_zeroes_data(struct block_device *bdev) 1349 { 1350 return queue_discard_zeroes_data(bdev_get_queue(bdev)); 1351 } 1352 1353 static inline unsigned int bdev_write_same(struct block_device *bdev) 1354 { 1355 struct request_queue *q = bdev_get_queue(bdev); 1356 1357 if (q) 1358 return q->limits.max_write_same_sectors; 1359 1360 return 0; 1361 } 1362 1363 static inline int queue_dma_alignment(struct request_queue *q) 1364 { 1365 return q ? q->dma_alignment : 511; 1366 } 1367 1368 static inline int blk_rq_aligned(struct request_queue *q, unsigned long addr, 1369 unsigned int len) 1370 { 1371 unsigned int alignment = queue_dma_alignment(q) | q->dma_pad_mask; 1372 return !(addr & alignment) && !(len & alignment); 1373 } 1374 1375 /* assumes size > 256 */ 1376 static inline unsigned int blksize_bits(unsigned int size) 1377 { 1378 unsigned int bits = 8; 1379 do { 1380 bits++; 1381 size >>= 1; 1382 } while (size > 256); 1383 return bits; 1384 } 1385 1386 static inline unsigned int block_size(struct block_device *bdev) 1387 { 1388 return bdev->bd_block_size; 1389 } 1390 1391 static inline bool queue_flush_queueable(struct request_queue *q) 1392 { 1393 return !q->flush_not_queueable; 1394 } 1395 1396 typedef struct {struct page *v;} Sector; 1397 1398 unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *); 1399 1400 static inline void put_dev_sector(Sector p) 1401 { 1402 page_cache_release(p.v); 1403 } 1404 1405 struct work_struct; 1406 int kblockd_schedule_work(struct work_struct *work); 1407 int kblockd_schedule_delayed_work(struct delayed_work *dwork, unsigned long delay); 1408 int kblockd_schedule_delayed_work_on(int cpu, struct delayed_work *dwork, unsigned long delay); 1409 1410 #ifdef CONFIG_BLK_CGROUP 1411 /* 1412 * This should not be using sched_clock(). A real patch is in progress 1413 * to fix this up, until that is in place we need to disable preemption 1414 * around sched_clock() in this function and set_io_start_time_ns(). 1415 */ 1416 static inline void set_start_time_ns(struct request *req) 1417 { 1418 preempt_disable(); 1419 req->start_time_ns = sched_clock(); 1420 preempt_enable(); 1421 } 1422 1423 static inline void set_io_start_time_ns(struct request *req) 1424 { 1425 preempt_disable(); 1426 req->io_start_time_ns = sched_clock(); 1427 preempt_enable(); 1428 } 1429 1430 static inline uint64_t rq_start_time_ns(struct request *req) 1431 { 1432 return req->start_time_ns; 1433 } 1434 1435 static inline uint64_t rq_io_start_time_ns(struct request *req) 1436 { 1437 return req->io_start_time_ns; 1438 } 1439 #else 1440 static inline void set_start_time_ns(struct request *req) {} 1441 static inline void set_io_start_time_ns(struct request *req) {} 1442 static inline uint64_t rq_start_time_ns(struct request *req) 1443 { 1444 return 0; 1445 } 1446 static inline uint64_t rq_io_start_time_ns(struct request *req) 1447 { 1448 return 0; 1449 } 1450 #endif 1451 1452 #define MODULE_ALIAS_BLOCKDEV(major,minor) \ 1453 MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor)) 1454 #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \ 1455 MODULE_ALIAS("block-major-" __stringify(major) "-*") 1456 1457 #if defined(CONFIG_BLK_DEV_INTEGRITY) 1458 1459 enum blk_integrity_flags { 1460 BLK_INTEGRITY_VERIFY = 1 << 0, 1461 BLK_INTEGRITY_GENERATE = 1 << 1, 1462 BLK_INTEGRITY_DEVICE_CAPABLE = 1 << 2, 1463 BLK_INTEGRITY_IP_CHECKSUM = 1 << 3, 1464 }; 1465 1466 struct blk_integrity_iter { 1467 void *prot_buf; 1468 void *data_buf; 1469 sector_t seed; 1470 unsigned int data_size; 1471 unsigned short interval; 1472 const char *disk_name; 1473 }; 1474 1475 typedef int (integrity_processing_fn) (struct blk_integrity_iter *); 1476 1477 struct blk_integrity { 1478 integrity_processing_fn *generate_fn; 1479 integrity_processing_fn *verify_fn; 1480 1481 unsigned short flags; 1482 unsigned short tuple_size; 1483 unsigned short interval; 1484 unsigned short tag_size; 1485 1486 const char *name; 1487 1488 struct kobject kobj; 1489 }; 1490 1491 extern bool blk_integrity_is_initialized(struct gendisk *); 1492 extern int blk_integrity_register(struct gendisk *, struct blk_integrity *); 1493 extern void blk_integrity_unregister(struct gendisk *); 1494 extern int blk_integrity_compare(struct gendisk *, struct gendisk *); 1495 extern int blk_rq_map_integrity_sg(struct request_queue *, struct bio *, 1496 struct scatterlist *); 1497 extern int blk_rq_count_integrity_sg(struct request_queue *, struct bio *); 1498 extern bool blk_integrity_merge_rq(struct request_queue *, struct request *, 1499 struct request *); 1500 extern bool blk_integrity_merge_bio(struct request_queue *, struct request *, 1501 struct bio *); 1502 1503 static inline 1504 struct blk_integrity *bdev_get_integrity(struct block_device *bdev) 1505 { 1506 return bdev->bd_disk->integrity; 1507 } 1508 1509 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk) 1510 { 1511 return disk->integrity; 1512 } 1513 1514 static inline bool blk_integrity_rq(struct request *rq) 1515 { 1516 return rq->cmd_flags & REQ_INTEGRITY; 1517 } 1518 1519 static inline void blk_queue_max_integrity_segments(struct request_queue *q, 1520 unsigned int segs) 1521 { 1522 q->limits.max_integrity_segments = segs; 1523 } 1524 1525 static inline unsigned short 1526 queue_max_integrity_segments(struct request_queue *q) 1527 { 1528 return q->limits.max_integrity_segments; 1529 } 1530 1531 #else /* CONFIG_BLK_DEV_INTEGRITY */ 1532 1533 struct bio; 1534 struct block_device; 1535 struct gendisk; 1536 struct blk_integrity; 1537 1538 static inline int blk_integrity_rq(struct request *rq) 1539 { 1540 return 0; 1541 } 1542 static inline int blk_rq_count_integrity_sg(struct request_queue *q, 1543 struct bio *b) 1544 { 1545 return 0; 1546 } 1547 static inline int blk_rq_map_integrity_sg(struct request_queue *q, 1548 struct bio *b, 1549 struct scatterlist *s) 1550 { 1551 return 0; 1552 } 1553 static inline struct blk_integrity *bdev_get_integrity(struct block_device *b) 1554 { 1555 return NULL; 1556 } 1557 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk) 1558 { 1559 return NULL; 1560 } 1561 static inline int blk_integrity_compare(struct gendisk *a, struct gendisk *b) 1562 { 1563 return 0; 1564 } 1565 static inline int blk_integrity_register(struct gendisk *d, 1566 struct blk_integrity *b) 1567 { 1568 return 0; 1569 } 1570 static inline void blk_integrity_unregister(struct gendisk *d) 1571 { 1572 } 1573 static inline void blk_queue_max_integrity_segments(struct request_queue *q, 1574 unsigned int segs) 1575 { 1576 } 1577 static inline unsigned short queue_max_integrity_segments(struct request_queue *q) 1578 { 1579 return 0; 1580 } 1581 static inline bool blk_integrity_merge_rq(struct request_queue *rq, 1582 struct request *r1, 1583 struct request *r2) 1584 { 1585 return true; 1586 } 1587 static inline bool blk_integrity_merge_bio(struct request_queue *rq, 1588 struct request *r, 1589 struct bio *b) 1590 { 1591 return true; 1592 } 1593 static inline bool blk_integrity_is_initialized(struct gendisk *g) 1594 { 1595 return 0; 1596 } 1597 1598 #endif /* CONFIG_BLK_DEV_INTEGRITY */ 1599 1600 struct block_device_operations { 1601 int (*open) (struct block_device *, fmode_t); 1602 void (*release) (struct gendisk *, fmode_t); 1603 int (*rw_page)(struct block_device *, sector_t, struct page *, int rw); 1604 int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long); 1605 int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long); 1606 int (*direct_access) (struct block_device *, sector_t, 1607 void **, unsigned long *); 1608 unsigned int (*check_events) (struct gendisk *disk, 1609 unsigned int clearing); 1610 /* ->media_changed() is DEPRECATED, use ->check_events() instead */ 1611 int (*media_changed) (struct gendisk *); 1612 void (*unlock_native_capacity) (struct gendisk *); 1613 int (*revalidate_disk) (struct gendisk *); 1614 int (*getgeo)(struct block_device *, struct hd_geometry *); 1615 /* this callback is with swap_lock and sometimes page table lock held */ 1616 void (*swap_slot_free_notify) (struct block_device *, unsigned long); 1617 struct module *owner; 1618 }; 1619 1620 extern int __blkdev_driver_ioctl(struct block_device *, fmode_t, unsigned int, 1621 unsigned long); 1622 extern int bdev_read_page(struct block_device *, sector_t, struct page *); 1623 extern int bdev_write_page(struct block_device *, sector_t, struct page *, 1624 struct writeback_control *); 1625 #else /* CONFIG_BLOCK */ 1626 1627 struct block_device; 1628 1629 /* 1630 * stubs for when the block layer is configured out 1631 */ 1632 #define buffer_heads_over_limit 0 1633 1634 static inline long nr_blockdev_pages(void) 1635 { 1636 return 0; 1637 } 1638 1639 struct blk_plug { 1640 }; 1641 1642 static inline void blk_start_plug(struct blk_plug *plug) 1643 { 1644 } 1645 1646 static inline void blk_finish_plug(struct blk_plug *plug) 1647 { 1648 } 1649 1650 static inline void blk_flush_plug(struct task_struct *task) 1651 { 1652 } 1653 1654 static inline void blk_schedule_flush_plug(struct task_struct *task) 1655 { 1656 } 1657 1658 1659 static inline bool blk_needs_flush_plug(struct task_struct *tsk) 1660 { 1661 return false; 1662 } 1663 1664 static inline int blkdev_issue_flush(struct block_device *bdev, gfp_t gfp_mask, 1665 sector_t *error_sector) 1666 { 1667 return 0; 1668 } 1669 1670 #endif /* CONFIG_BLOCK */ 1671 1672 #endif 1673