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 40 #define BLKDEV_MIN_RQ 4 41 #define BLKDEV_MAX_RQ 128 /* Default maximum */ 42 43 /* 44 * Maximum number of blkcg policies allowed to be registered concurrently. 45 * Defined here to simplify include dependency. 46 */ 47 #define BLKCG_MAX_POLS 2 48 49 struct request; 50 typedef void (rq_end_io_fn)(struct request *, int); 51 52 #define BLK_RL_SYNCFULL (1U << 0) 53 #define BLK_RL_ASYNCFULL (1U << 1) 54 55 struct request_list { 56 struct request_queue *q; /* the queue this rl belongs to */ 57 #ifdef CONFIG_BLK_CGROUP 58 struct blkcg_gq *blkg; /* blkg this request pool belongs to */ 59 #endif 60 /* 61 * count[], starved[], and wait[] are indexed by 62 * BLK_RW_SYNC/BLK_RW_ASYNC 63 */ 64 int count[2]; 65 int starved[2]; 66 mempool_t *rq_pool; 67 wait_queue_head_t wait[2]; 68 unsigned int flags; 69 }; 70 71 /* 72 * request command types 73 */ 74 enum rq_cmd_type_bits { 75 REQ_TYPE_FS = 1, /* fs request */ 76 REQ_TYPE_BLOCK_PC, /* scsi command */ 77 REQ_TYPE_SENSE, /* sense request */ 78 REQ_TYPE_PM_SUSPEND, /* suspend request */ 79 REQ_TYPE_PM_RESUME, /* resume request */ 80 REQ_TYPE_PM_SHUTDOWN, /* shutdown request */ 81 REQ_TYPE_SPECIAL, /* driver defined type */ 82 /* 83 * for ATA/ATAPI devices. this really doesn't belong here, ide should 84 * use REQ_TYPE_SPECIAL and use rq->cmd[0] with the range of driver 85 * private REQ_LB opcodes to differentiate what type of request this is 86 */ 87 REQ_TYPE_ATA_TASKFILE, 88 REQ_TYPE_ATA_PC, 89 }; 90 91 #define BLK_MAX_CDB 16 92 93 /* 94 * Try to put the fields that are referenced together in the same cacheline. 95 * 96 * If you modify this structure, make sure to update blk_rq_init() and 97 * especially blk_mq_rq_ctx_init() to take care of the added fields. 98 */ 99 struct request { 100 struct list_head queuelist; 101 union { 102 struct call_single_data csd; 103 unsigned long fifo_time; 104 }; 105 106 struct request_queue *q; 107 struct blk_mq_ctx *mq_ctx; 108 109 u64 cmd_flags; 110 enum rq_cmd_type_bits cmd_type; 111 unsigned long atomic_flags; 112 113 int cpu; 114 115 /* the following two fields are internal, NEVER access directly */ 116 unsigned int __data_len; /* total data len */ 117 sector_t __sector; /* sector cursor */ 118 119 struct bio *bio; 120 struct bio *biotail; 121 122 /* 123 * The hash is used inside the scheduler, and killed once the 124 * request reaches the dispatch list. The ipi_list is only used 125 * to queue the request for softirq completion, which is long 126 * after the request has been unhashed (and even removed from 127 * the dispatch list). 128 */ 129 union { 130 struct hlist_node hash; /* merge hash */ 131 struct list_head ipi_list; 132 }; 133 134 /* 135 * The rb_node is only used inside the io scheduler, requests 136 * are pruned when moved to the dispatch queue. So let the 137 * completion_data share space with the rb_node. 138 */ 139 union { 140 struct rb_node rb_node; /* sort/lookup */ 141 void *completion_data; 142 }; 143 144 /* 145 * Three pointers are available for the IO schedulers, if they need 146 * more they have to dynamically allocate it. Flush requests are 147 * never put on the IO scheduler. So let the flush fields share 148 * space with the elevator data. 149 */ 150 union { 151 struct { 152 struct io_cq *icq; 153 void *priv[2]; 154 } elv; 155 156 struct { 157 unsigned int seq; 158 struct list_head list; 159 rq_end_io_fn *saved_end_io; 160 } flush; 161 }; 162 163 struct gendisk *rq_disk; 164 struct hd_struct *part; 165 unsigned long start_time; 166 #ifdef CONFIG_BLK_CGROUP 167 struct request_list *rl; /* rl this rq is alloced from */ 168 unsigned long long start_time_ns; 169 unsigned long long io_start_time_ns; /* when passed to hardware */ 170 #endif 171 /* Number of scatter-gather DMA addr+len pairs after 172 * physical address coalescing is performed. 173 */ 174 unsigned short nr_phys_segments; 175 #if defined(CONFIG_BLK_DEV_INTEGRITY) 176 unsigned short nr_integrity_segments; 177 #endif 178 179 unsigned short ioprio; 180 181 void *special; /* opaque pointer available for LLD use */ 182 183 int tag; 184 int errors; 185 186 /* 187 * when request is used as a packet command carrier 188 */ 189 unsigned char __cmd[BLK_MAX_CDB]; 190 unsigned char *cmd; 191 unsigned short cmd_len; 192 193 unsigned int extra_len; /* length of alignment and padding */ 194 unsigned int sense_len; 195 unsigned int resid_len; /* residual count */ 196 void *sense; 197 198 unsigned long deadline; 199 struct list_head timeout_list; 200 unsigned int timeout; 201 int retries; 202 203 /* 204 * completion callback. 205 */ 206 rq_end_io_fn *end_io; 207 void *end_io_data; 208 209 /* for bidi */ 210 struct request *next_rq; 211 }; 212 213 static inline unsigned short req_get_ioprio(struct request *req) 214 { 215 return req->ioprio; 216 } 217 218 /* 219 * State information carried for REQ_TYPE_PM_SUSPEND and REQ_TYPE_PM_RESUME 220 * requests. Some step values could eventually be made generic. 221 */ 222 struct request_pm_state 223 { 224 /* PM state machine step value, currently driver specific */ 225 int pm_step; 226 /* requested PM state value (S1, S2, S3, S4, ...) */ 227 u32 pm_state; 228 void* data; /* for driver use */ 229 }; 230 231 #include <linux/elevator.h> 232 233 struct blk_queue_ctx; 234 235 typedef void (request_fn_proc) (struct request_queue *q); 236 typedef void (make_request_fn) (struct request_queue *q, struct bio *bio); 237 typedef int (prep_rq_fn) (struct request_queue *, struct request *); 238 typedef void (unprep_rq_fn) (struct request_queue *, struct request *); 239 240 struct bio_vec; 241 struct bvec_merge_data { 242 struct block_device *bi_bdev; 243 sector_t bi_sector; 244 unsigned bi_size; 245 unsigned long bi_rw; 246 }; 247 typedef int (merge_bvec_fn) (struct request_queue *, struct bvec_merge_data *, 248 struct bio_vec *); 249 typedef void (softirq_done_fn)(struct request *); 250 typedef int (dma_drain_needed_fn)(struct request *); 251 typedef int (lld_busy_fn) (struct request_queue *q); 252 typedef int (bsg_job_fn) (struct bsg_job *); 253 254 enum blk_eh_timer_return { 255 BLK_EH_NOT_HANDLED, 256 BLK_EH_HANDLED, 257 BLK_EH_RESET_TIMER, 258 }; 259 260 typedef enum blk_eh_timer_return (rq_timed_out_fn)(struct request *); 261 262 enum blk_queue_state { 263 Queue_down, 264 Queue_up, 265 }; 266 267 struct blk_queue_tag { 268 struct request **tag_index; /* map of busy tags */ 269 unsigned long *tag_map; /* bit map of free/busy tags */ 270 int busy; /* current depth */ 271 int max_depth; /* what we will send to device */ 272 int real_max_depth; /* what the array can hold */ 273 atomic_t refcnt; /* map can be shared */ 274 }; 275 276 #define BLK_SCSI_MAX_CMDS (256) 277 #define BLK_SCSI_CMD_PER_LONG (BLK_SCSI_MAX_CMDS / (sizeof(long) * 8)) 278 279 struct queue_limits { 280 unsigned long bounce_pfn; 281 unsigned long seg_boundary_mask; 282 283 unsigned int max_hw_sectors; 284 unsigned int chunk_sectors; 285 unsigned int max_sectors; 286 unsigned int max_segment_size; 287 unsigned int physical_block_size; 288 unsigned int alignment_offset; 289 unsigned int io_min; 290 unsigned int io_opt; 291 unsigned int max_discard_sectors; 292 unsigned int max_write_same_sectors; 293 unsigned int discard_granularity; 294 unsigned int discard_alignment; 295 296 unsigned short logical_block_size; 297 unsigned short max_segments; 298 unsigned short max_integrity_segments; 299 300 unsigned char misaligned; 301 unsigned char discard_misaligned; 302 unsigned char cluster; 303 unsigned char discard_zeroes_data; 304 unsigned char raid_partial_stripes_expensive; 305 }; 306 307 struct request_queue { 308 /* 309 * Together with queue_head for cacheline sharing 310 */ 311 struct list_head queue_head; 312 struct request *last_merge; 313 struct elevator_queue *elevator; 314 int nr_rqs[2]; /* # allocated [a]sync rqs */ 315 int nr_rqs_elvpriv; /* # allocated rqs w/ elvpriv */ 316 317 /* 318 * If blkcg is not used, @q->root_rl serves all requests. If blkcg 319 * is used, root blkg allocates from @q->root_rl and all other 320 * blkgs from their own blkg->rl. Which one to use should be 321 * determined using bio_request_list(). 322 */ 323 struct request_list root_rl; 324 325 request_fn_proc *request_fn; 326 make_request_fn *make_request_fn; 327 prep_rq_fn *prep_rq_fn; 328 unprep_rq_fn *unprep_rq_fn; 329 merge_bvec_fn *merge_bvec_fn; 330 softirq_done_fn *softirq_done_fn; 331 rq_timed_out_fn *rq_timed_out_fn; 332 dma_drain_needed_fn *dma_drain_needed; 333 lld_busy_fn *lld_busy_fn; 334 335 struct blk_mq_ops *mq_ops; 336 337 unsigned int *mq_map; 338 339 /* sw queues */ 340 struct blk_mq_ctx __percpu *queue_ctx; 341 unsigned int nr_queues; 342 343 /* hw dispatch queues */ 344 struct blk_mq_hw_ctx **queue_hw_ctx; 345 unsigned int nr_hw_queues; 346 347 /* 348 * Dispatch queue sorting 349 */ 350 sector_t end_sector; 351 struct request *boundary_rq; 352 353 /* 354 * Delayed queue handling 355 */ 356 struct delayed_work delay_work; 357 358 struct backing_dev_info backing_dev_info; 359 360 /* 361 * The queue owner gets to use this for whatever they like. 362 * ll_rw_blk doesn't touch it. 363 */ 364 void *queuedata; 365 366 /* 367 * various queue flags, see QUEUE_* below 368 */ 369 unsigned long queue_flags; 370 371 /* 372 * ida allocated id for this queue. Used to index queues from 373 * ioctx. 374 */ 375 int id; 376 377 /* 378 * queue needs bounce pages for pages above this limit 379 */ 380 gfp_t bounce_gfp; 381 382 /* 383 * protects queue structures from reentrancy. ->__queue_lock should 384 * _never_ be used directly, it is queue private. always use 385 * ->queue_lock. 386 */ 387 spinlock_t __queue_lock; 388 spinlock_t *queue_lock; 389 390 /* 391 * queue kobject 392 */ 393 struct kobject kobj; 394 395 /* 396 * mq queue kobject 397 */ 398 struct kobject mq_kobj; 399 400 #ifdef CONFIG_PM_RUNTIME 401 struct device *dev; 402 int rpm_status; 403 unsigned int nr_pending; 404 #endif 405 406 /* 407 * queue settings 408 */ 409 unsigned long nr_requests; /* Max # of requests */ 410 unsigned int nr_congestion_on; 411 unsigned int nr_congestion_off; 412 unsigned int nr_batching; 413 414 unsigned int dma_drain_size; 415 void *dma_drain_buffer; 416 unsigned int dma_pad_mask; 417 unsigned int dma_alignment; 418 419 struct blk_queue_tag *queue_tags; 420 struct list_head tag_busy_list; 421 422 unsigned int nr_sorted; 423 unsigned int in_flight[2]; 424 /* 425 * Number of active block driver functions for which blk_drain_queue() 426 * must wait. Must be incremented around functions that unlock the 427 * queue_lock internally, e.g. scsi_request_fn(). 428 */ 429 unsigned int request_fn_active; 430 431 unsigned int rq_timeout; 432 struct timer_list timeout; 433 struct list_head timeout_list; 434 435 struct list_head icq_list; 436 #ifdef CONFIG_BLK_CGROUP 437 DECLARE_BITMAP (blkcg_pols, BLKCG_MAX_POLS); 438 struct blkcg_gq *root_blkg; 439 struct list_head blkg_list; 440 #endif 441 442 struct queue_limits limits; 443 444 /* 445 * sg stuff 446 */ 447 unsigned int sg_timeout; 448 unsigned int sg_reserved_size; 449 int node; 450 #ifdef CONFIG_BLK_DEV_IO_TRACE 451 struct blk_trace *blk_trace; 452 #endif 453 /* 454 * for flush operations 455 */ 456 unsigned int flush_flags; 457 unsigned int flush_not_queueable:1; 458 unsigned int flush_queue_delayed:1; 459 unsigned int flush_pending_idx:1; 460 unsigned int flush_running_idx:1; 461 unsigned long flush_pending_since; 462 struct list_head flush_queue[2]; 463 struct list_head flush_data_in_flight; 464 struct request *flush_rq; 465 spinlock_t mq_flush_lock; 466 467 struct list_head requeue_list; 468 spinlock_t requeue_lock; 469 struct work_struct requeue_work; 470 471 struct mutex sysfs_lock; 472 473 int bypass_depth; 474 int mq_freeze_depth; 475 476 #if defined(CONFIG_BLK_DEV_BSG) 477 bsg_job_fn *bsg_job_fn; 478 int bsg_job_size; 479 struct bsg_class_device bsg_dev; 480 #endif 481 482 #ifdef CONFIG_BLK_DEV_THROTTLING 483 /* Throttle data */ 484 struct throtl_data *td; 485 #endif 486 struct rcu_head rcu_head; 487 wait_queue_head_t mq_freeze_wq; 488 struct percpu_ref mq_usage_counter; 489 struct list_head all_q_node; 490 491 struct blk_mq_tag_set *tag_set; 492 struct list_head tag_set_list; 493 }; 494 495 #define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */ 496 #define QUEUE_FLAG_STOPPED 2 /* queue is stopped */ 497 #define QUEUE_FLAG_SYNCFULL 3 /* read queue has been filled */ 498 #define QUEUE_FLAG_ASYNCFULL 4 /* write queue has been filled */ 499 #define QUEUE_FLAG_DYING 5 /* queue being torn down */ 500 #define QUEUE_FLAG_BYPASS 6 /* act as dumb FIFO queue */ 501 #define QUEUE_FLAG_BIDI 7 /* queue supports bidi requests */ 502 #define QUEUE_FLAG_NOMERGES 8 /* disable merge attempts */ 503 #define QUEUE_FLAG_SAME_COMP 9 /* complete on same CPU-group */ 504 #define QUEUE_FLAG_FAIL_IO 10 /* fake timeout */ 505 #define QUEUE_FLAG_STACKABLE 11 /* supports request stacking */ 506 #define QUEUE_FLAG_NONROT 12 /* non-rotational device (SSD) */ 507 #define QUEUE_FLAG_VIRT QUEUE_FLAG_NONROT /* paravirt device */ 508 #define QUEUE_FLAG_IO_STAT 13 /* do IO stats */ 509 #define QUEUE_FLAG_DISCARD 14 /* supports DISCARD */ 510 #define QUEUE_FLAG_NOXMERGES 15 /* No extended merges */ 511 #define QUEUE_FLAG_ADD_RANDOM 16 /* Contributes to random pool */ 512 #define QUEUE_FLAG_SECDISCARD 17 /* supports SECDISCARD */ 513 #define QUEUE_FLAG_SAME_FORCE 18 /* force complete on same CPU */ 514 #define QUEUE_FLAG_DEAD 19 /* queue tear-down finished */ 515 #define QUEUE_FLAG_INIT_DONE 20 /* queue is initialized */ 516 #define QUEUE_FLAG_NO_SG_MERGE 21 /* don't attempt to merge SG segments*/ 517 #define QUEUE_FLAG_SG_GAPS 22 /* queue doesn't support SG gaps */ 518 519 #define QUEUE_FLAG_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \ 520 (1 << QUEUE_FLAG_STACKABLE) | \ 521 (1 << QUEUE_FLAG_SAME_COMP) | \ 522 (1 << QUEUE_FLAG_ADD_RANDOM)) 523 524 #define QUEUE_FLAG_MQ_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \ 525 (1 << QUEUE_FLAG_SAME_COMP)) 526 527 static inline void queue_lockdep_assert_held(struct request_queue *q) 528 { 529 if (q->queue_lock) 530 lockdep_assert_held(q->queue_lock); 531 } 532 533 static inline void queue_flag_set_unlocked(unsigned int flag, 534 struct request_queue *q) 535 { 536 __set_bit(flag, &q->queue_flags); 537 } 538 539 static inline int queue_flag_test_and_clear(unsigned int flag, 540 struct request_queue *q) 541 { 542 queue_lockdep_assert_held(q); 543 544 if (test_bit(flag, &q->queue_flags)) { 545 __clear_bit(flag, &q->queue_flags); 546 return 1; 547 } 548 549 return 0; 550 } 551 552 static inline int queue_flag_test_and_set(unsigned int flag, 553 struct request_queue *q) 554 { 555 queue_lockdep_assert_held(q); 556 557 if (!test_bit(flag, &q->queue_flags)) { 558 __set_bit(flag, &q->queue_flags); 559 return 0; 560 } 561 562 return 1; 563 } 564 565 static inline void queue_flag_set(unsigned int flag, struct request_queue *q) 566 { 567 queue_lockdep_assert_held(q); 568 __set_bit(flag, &q->queue_flags); 569 } 570 571 static inline void queue_flag_clear_unlocked(unsigned int flag, 572 struct request_queue *q) 573 { 574 __clear_bit(flag, &q->queue_flags); 575 } 576 577 static inline int queue_in_flight(struct request_queue *q) 578 { 579 return q->in_flight[0] + q->in_flight[1]; 580 } 581 582 static inline void queue_flag_clear(unsigned int flag, struct request_queue *q) 583 { 584 queue_lockdep_assert_held(q); 585 __clear_bit(flag, &q->queue_flags); 586 } 587 588 #define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags) 589 #define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags) 590 #define blk_queue_dying(q) test_bit(QUEUE_FLAG_DYING, &(q)->queue_flags) 591 #define blk_queue_dead(q) test_bit(QUEUE_FLAG_DEAD, &(q)->queue_flags) 592 #define blk_queue_bypass(q) test_bit(QUEUE_FLAG_BYPASS, &(q)->queue_flags) 593 #define blk_queue_init_done(q) test_bit(QUEUE_FLAG_INIT_DONE, &(q)->queue_flags) 594 #define blk_queue_nomerges(q) test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags) 595 #define blk_queue_noxmerges(q) \ 596 test_bit(QUEUE_FLAG_NOXMERGES, &(q)->queue_flags) 597 #define blk_queue_nonrot(q) test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags) 598 #define blk_queue_io_stat(q) test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags) 599 #define blk_queue_add_random(q) test_bit(QUEUE_FLAG_ADD_RANDOM, &(q)->queue_flags) 600 #define blk_queue_stackable(q) \ 601 test_bit(QUEUE_FLAG_STACKABLE, &(q)->queue_flags) 602 #define blk_queue_discard(q) test_bit(QUEUE_FLAG_DISCARD, &(q)->queue_flags) 603 #define blk_queue_secdiscard(q) (blk_queue_discard(q) && \ 604 test_bit(QUEUE_FLAG_SECDISCARD, &(q)->queue_flags)) 605 606 #define blk_noretry_request(rq) \ 607 ((rq)->cmd_flags & (REQ_FAILFAST_DEV|REQ_FAILFAST_TRANSPORT| \ 608 REQ_FAILFAST_DRIVER)) 609 610 #define blk_account_rq(rq) \ 611 (((rq)->cmd_flags & REQ_STARTED) && \ 612 ((rq)->cmd_type == REQ_TYPE_FS)) 613 614 #define blk_pm_request(rq) \ 615 ((rq)->cmd_type == REQ_TYPE_PM_SUSPEND || \ 616 (rq)->cmd_type == REQ_TYPE_PM_RESUME) 617 618 #define blk_rq_cpu_valid(rq) ((rq)->cpu != -1) 619 #define blk_bidi_rq(rq) ((rq)->next_rq != NULL) 620 /* rq->queuelist of dequeued request must be list_empty() */ 621 #define blk_queued_rq(rq) (!list_empty(&(rq)->queuelist)) 622 623 #define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist) 624 625 #define rq_data_dir(rq) (((rq)->cmd_flags & 1) != 0) 626 627 /* 628 * Driver can handle struct request, if it either has an old style 629 * request_fn defined, or is blk-mq based. 630 */ 631 static inline bool queue_is_rq_based(struct request_queue *q) 632 { 633 return q->request_fn || q->mq_ops; 634 } 635 636 static inline unsigned int blk_queue_cluster(struct request_queue *q) 637 { 638 return q->limits.cluster; 639 } 640 641 /* 642 * We regard a request as sync, if either a read or a sync write 643 */ 644 static inline bool rw_is_sync(unsigned int rw_flags) 645 { 646 return !(rw_flags & REQ_WRITE) || (rw_flags & REQ_SYNC); 647 } 648 649 static inline bool rq_is_sync(struct request *rq) 650 { 651 return rw_is_sync(rq->cmd_flags); 652 } 653 654 static inline bool blk_rl_full(struct request_list *rl, bool sync) 655 { 656 unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL; 657 658 return rl->flags & flag; 659 } 660 661 static inline void blk_set_rl_full(struct request_list *rl, bool sync) 662 { 663 unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL; 664 665 rl->flags |= flag; 666 } 667 668 static inline void blk_clear_rl_full(struct request_list *rl, bool sync) 669 { 670 unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL; 671 672 rl->flags &= ~flag; 673 } 674 675 static inline bool rq_mergeable(struct request *rq) 676 { 677 if (rq->cmd_type != REQ_TYPE_FS) 678 return false; 679 680 if (rq->cmd_flags & REQ_NOMERGE_FLAGS) 681 return false; 682 683 return true; 684 } 685 686 static inline bool blk_check_merge_flags(unsigned int flags1, 687 unsigned int flags2) 688 { 689 if ((flags1 & REQ_DISCARD) != (flags2 & REQ_DISCARD)) 690 return false; 691 692 if ((flags1 & REQ_SECURE) != (flags2 & REQ_SECURE)) 693 return false; 694 695 if ((flags1 & REQ_WRITE_SAME) != (flags2 & REQ_WRITE_SAME)) 696 return false; 697 698 return true; 699 } 700 701 static inline bool blk_write_same_mergeable(struct bio *a, struct bio *b) 702 { 703 if (bio_data(a) == bio_data(b)) 704 return true; 705 706 return false; 707 } 708 709 /* 710 * q->prep_rq_fn return values 711 */ 712 #define BLKPREP_OK 0 /* serve it */ 713 #define BLKPREP_KILL 1 /* fatal error, kill */ 714 #define BLKPREP_DEFER 2 /* leave on queue */ 715 716 extern unsigned long blk_max_low_pfn, blk_max_pfn; 717 718 /* 719 * standard bounce addresses: 720 * 721 * BLK_BOUNCE_HIGH : bounce all highmem pages 722 * BLK_BOUNCE_ANY : don't bounce anything 723 * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary 724 */ 725 726 #if BITS_PER_LONG == 32 727 #define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT) 728 #else 729 #define BLK_BOUNCE_HIGH -1ULL 730 #endif 731 #define BLK_BOUNCE_ANY (-1ULL) 732 #define BLK_BOUNCE_ISA (DMA_BIT_MASK(24)) 733 734 /* 735 * default timeout for SG_IO if none specified 736 */ 737 #define BLK_DEFAULT_SG_TIMEOUT (60 * HZ) 738 #define BLK_MIN_SG_TIMEOUT (7 * HZ) 739 740 #ifdef CONFIG_BOUNCE 741 extern int init_emergency_isa_pool(void); 742 extern void blk_queue_bounce(struct request_queue *q, struct bio **bio); 743 #else 744 static inline int init_emergency_isa_pool(void) 745 { 746 return 0; 747 } 748 static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio) 749 { 750 } 751 #endif /* CONFIG_MMU */ 752 753 struct rq_map_data { 754 struct page **pages; 755 int page_order; 756 int nr_entries; 757 unsigned long offset; 758 int null_mapped; 759 int from_user; 760 }; 761 762 struct req_iterator { 763 struct bvec_iter iter; 764 struct bio *bio; 765 }; 766 767 /* This should not be used directly - use rq_for_each_segment */ 768 #define for_each_bio(_bio) \ 769 for (; _bio; _bio = _bio->bi_next) 770 #define __rq_for_each_bio(_bio, rq) \ 771 if ((rq->bio)) \ 772 for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next) 773 774 #define rq_for_each_segment(bvl, _rq, _iter) \ 775 __rq_for_each_bio(_iter.bio, _rq) \ 776 bio_for_each_segment(bvl, _iter.bio, _iter.iter) 777 778 #define rq_iter_last(bvec, _iter) \ 779 (_iter.bio->bi_next == NULL && \ 780 bio_iter_last(bvec, _iter.iter)) 781 782 #ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 783 # error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform" 784 #endif 785 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 786 extern void rq_flush_dcache_pages(struct request *rq); 787 #else 788 static inline void rq_flush_dcache_pages(struct request *rq) 789 { 790 } 791 #endif 792 793 extern int blk_register_queue(struct gendisk *disk); 794 extern void blk_unregister_queue(struct gendisk *disk); 795 extern void generic_make_request(struct bio *bio); 796 extern void blk_rq_init(struct request_queue *q, struct request *rq); 797 extern void blk_put_request(struct request *); 798 extern void __blk_put_request(struct request_queue *, struct request *); 799 extern struct request *blk_get_request(struct request_queue *, int, gfp_t); 800 extern struct request *blk_make_request(struct request_queue *, struct bio *, 801 gfp_t); 802 extern void blk_rq_set_block_pc(struct request *); 803 extern void blk_requeue_request(struct request_queue *, struct request *); 804 extern void blk_add_request_payload(struct request *rq, struct page *page, 805 unsigned int len); 806 extern int blk_rq_check_limits(struct request_queue *q, struct request *rq); 807 extern int blk_lld_busy(struct request_queue *q); 808 extern int blk_rq_prep_clone(struct request *rq, struct request *rq_src, 809 struct bio_set *bs, gfp_t gfp_mask, 810 int (*bio_ctr)(struct bio *, struct bio *, void *), 811 void *data); 812 extern void blk_rq_unprep_clone(struct request *rq); 813 extern int blk_insert_cloned_request(struct request_queue *q, 814 struct request *rq); 815 extern void blk_delay_queue(struct request_queue *, unsigned long); 816 extern void blk_recount_segments(struct request_queue *, struct bio *); 817 extern int scsi_verify_blk_ioctl(struct block_device *, unsigned int); 818 extern int scsi_cmd_blk_ioctl(struct block_device *, fmode_t, 819 unsigned int, void __user *); 820 extern int scsi_cmd_ioctl(struct request_queue *, struct gendisk *, fmode_t, 821 unsigned int, void __user *); 822 extern int sg_scsi_ioctl(struct request_queue *, struct gendisk *, fmode_t, 823 struct scsi_ioctl_command __user *); 824 825 extern void blk_queue_bio(struct request_queue *q, struct bio *bio); 826 827 /* 828 * A queue has just exitted congestion. Note this in the global counter of 829 * congested queues, and wake up anyone who was waiting for requests to be 830 * put back. 831 */ 832 static inline void blk_clear_queue_congested(struct request_queue *q, int sync) 833 { 834 clear_bdi_congested(&q->backing_dev_info, sync); 835 } 836 837 /* 838 * A queue has just entered congestion. Flag that in the queue's VM-visible 839 * state flags and increment the global gounter of congested queues. 840 */ 841 static inline void blk_set_queue_congested(struct request_queue *q, int sync) 842 { 843 set_bdi_congested(&q->backing_dev_info, sync); 844 } 845 846 extern void blk_start_queue(struct request_queue *q); 847 extern void blk_stop_queue(struct request_queue *q); 848 extern void blk_sync_queue(struct request_queue *q); 849 extern void __blk_stop_queue(struct request_queue *q); 850 extern void __blk_run_queue(struct request_queue *q); 851 extern void blk_run_queue(struct request_queue *); 852 extern void blk_run_queue_async(struct request_queue *q); 853 extern int blk_rq_map_user(struct request_queue *, struct request *, 854 struct rq_map_data *, void __user *, unsigned long, 855 gfp_t); 856 extern int blk_rq_unmap_user(struct bio *); 857 extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, unsigned int, gfp_t); 858 extern int blk_rq_map_user_iov(struct request_queue *, struct request *, 859 struct rq_map_data *, const struct sg_iovec *, 860 int, unsigned int, gfp_t); 861 extern int blk_execute_rq(struct request_queue *, struct gendisk *, 862 struct request *, int); 863 extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *, 864 struct request *, int, rq_end_io_fn *); 865 866 static inline struct request_queue *bdev_get_queue(struct block_device *bdev) 867 { 868 return bdev->bd_disk->queue; 869 } 870 871 /* 872 * blk_rq_pos() : the current sector 873 * blk_rq_bytes() : bytes left in the entire request 874 * blk_rq_cur_bytes() : bytes left in the current segment 875 * blk_rq_err_bytes() : bytes left till the next error boundary 876 * blk_rq_sectors() : sectors left in the entire request 877 * blk_rq_cur_sectors() : sectors left in the current segment 878 */ 879 static inline sector_t blk_rq_pos(const struct request *rq) 880 { 881 return rq->__sector; 882 } 883 884 static inline unsigned int blk_rq_bytes(const struct request *rq) 885 { 886 return rq->__data_len; 887 } 888 889 static inline int blk_rq_cur_bytes(const struct request *rq) 890 { 891 return rq->bio ? bio_cur_bytes(rq->bio) : 0; 892 } 893 894 extern unsigned int blk_rq_err_bytes(const struct request *rq); 895 896 static inline unsigned int blk_rq_sectors(const struct request *rq) 897 { 898 return blk_rq_bytes(rq) >> 9; 899 } 900 901 static inline unsigned int blk_rq_cur_sectors(const struct request *rq) 902 { 903 return blk_rq_cur_bytes(rq) >> 9; 904 } 905 906 static inline unsigned int blk_queue_get_max_sectors(struct request_queue *q, 907 unsigned int cmd_flags) 908 { 909 if (unlikely(cmd_flags & REQ_DISCARD)) 910 return min(q->limits.max_discard_sectors, UINT_MAX >> 9); 911 912 if (unlikely(cmd_flags & REQ_WRITE_SAME)) 913 return q->limits.max_write_same_sectors; 914 915 return q->limits.max_sectors; 916 } 917 918 /* 919 * Return maximum size of a request at given offset. Only valid for 920 * file system requests. 921 */ 922 static inline unsigned int blk_max_size_offset(struct request_queue *q, 923 sector_t offset) 924 { 925 if (!q->limits.chunk_sectors) 926 return q->limits.max_sectors; 927 928 return q->limits.chunk_sectors - 929 (offset & (q->limits.chunk_sectors - 1)); 930 } 931 932 static inline unsigned int blk_rq_get_max_sectors(struct request *rq) 933 { 934 struct request_queue *q = rq->q; 935 936 if (unlikely(rq->cmd_type == REQ_TYPE_BLOCK_PC)) 937 return q->limits.max_hw_sectors; 938 939 if (!q->limits.chunk_sectors) 940 return blk_queue_get_max_sectors(q, rq->cmd_flags); 941 942 return min(blk_max_size_offset(q, blk_rq_pos(rq)), 943 blk_queue_get_max_sectors(q, rq->cmd_flags)); 944 } 945 946 static inline unsigned int blk_rq_count_bios(struct request *rq) 947 { 948 unsigned int nr_bios = 0; 949 struct bio *bio; 950 951 __rq_for_each_bio(bio, rq) 952 nr_bios++; 953 954 return nr_bios; 955 } 956 957 /* 958 * Request issue related functions. 959 */ 960 extern struct request *blk_peek_request(struct request_queue *q); 961 extern void blk_start_request(struct request *rq); 962 extern struct request *blk_fetch_request(struct request_queue *q); 963 964 /* 965 * Request completion related functions. 966 * 967 * blk_update_request() completes given number of bytes and updates 968 * the request without completing it. 969 * 970 * blk_end_request() and friends. __blk_end_request() must be called 971 * with the request queue spinlock acquired. 972 * 973 * Several drivers define their own end_request and call 974 * blk_end_request() for parts of the original function. 975 * This prevents code duplication in drivers. 976 */ 977 extern bool blk_update_request(struct request *rq, int error, 978 unsigned int nr_bytes); 979 extern void blk_finish_request(struct request *rq, int error); 980 extern bool blk_end_request(struct request *rq, int error, 981 unsigned int nr_bytes); 982 extern void blk_end_request_all(struct request *rq, int error); 983 extern bool blk_end_request_cur(struct request *rq, int error); 984 extern bool blk_end_request_err(struct request *rq, int error); 985 extern bool __blk_end_request(struct request *rq, int error, 986 unsigned int nr_bytes); 987 extern void __blk_end_request_all(struct request *rq, int error); 988 extern bool __blk_end_request_cur(struct request *rq, int error); 989 extern bool __blk_end_request_err(struct request *rq, int error); 990 991 extern void blk_complete_request(struct request *); 992 extern void __blk_complete_request(struct request *); 993 extern void blk_abort_request(struct request *); 994 extern void blk_unprep_request(struct request *); 995 996 /* 997 * Access functions for manipulating queue properties 998 */ 999 extern struct request_queue *blk_init_queue_node(request_fn_proc *rfn, 1000 spinlock_t *lock, int node_id); 1001 extern struct request_queue *blk_init_queue(request_fn_proc *, spinlock_t *); 1002 extern struct request_queue *blk_init_allocated_queue(struct request_queue *, 1003 request_fn_proc *, spinlock_t *); 1004 extern void blk_cleanup_queue(struct request_queue *); 1005 extern void blk_queue_make_request(struct request_queue *, make_request_fn *); 1006 extern void blk_queue_bounce_limit(struct request_queue *, u64); 1007 extern void blk_limits_max_hw_sectors(struct queue_limits *, unsigned int); 1008 extern void blk_queue_max_hw_sectors(struct request_queue *, unsigned int); 1009 extern void blk_queue_chunk_sectors(struct request_queue *, unsigned int); 1010 extern void blk_queue_max_segments(struct request_queue *, unsigned short); 1011 extern void blk_queue_max_segment_size(struct request_queue *, unsigned int); 1012 extern void blk_queue_max_discard_sectors(struct request_queue *q, 1013 unsigned int max_discard_sectors); 1014 extern void blk_queue_max_write_same_sectors(struct request_queue *q, 1015 unsigned int max_write_same_sectors); 1016 extern void blk_queue_logical_block_size(struct request_queue *, unsigned short); 1017 extern void blk_queue_physical_block_size(struct request_queue *, unsigned int); 1018 extern void blk_queue_alignment_offset(struct request_queue *q, 1019 unsigned int alignment); 1020 extern void blk_limits_io_min(struct queue_limits *limits, unsigned int min); 1021 extern void blk_queue_io_min(struct request_queue *q, unsigned int min); 1022 extern void blk_limits_io_opt(struct queue_limits *limits, unsigned int opt); 1023 extern void blk_queue_io_opt(struct request_queue *q, unsigned int opt); 1024 extern void blk_set_default_limits(struct queue_limits *lim); 1025 extern void blk_set_stacking_limits(struct queue_limits *lim); 1026 extern int blk_stack_limits(struct queue_limits *t, struct queue_limits *b, 1027 sector_t offset); 1028 extern int bdev_stack_limits(struct queue_limits *t, struct block_device *bdev, 1029 sector_t offset); 1030 extern void disk_stack_limits(struct gendisk *disk, struct block_device *bdev, 1031 sector_t offset); 1032 extern void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b); 1033 extern void blk_queue_dma_pad(struct request_queue *, unsigned int); 1034 extern void blk_queue_update_dma_pad(struct request_queue *, unsigned int); 1035 extern int blk_queue_dma_drain(struct request_queue *q, 1036 dma_drain_needed_fn *dma_drain_needed, 1037 void *buf, unsigned int size); 1038 extern void blk_queue_lld_busy(struct request_queue *q, lld_busy_fn *fn); 1039 extern void blk_queue_segment_boundary(struct request_queue *, unsigned long); 1040 extern void blk_queue_prep_rq(struct request_queue *, prep_rq_fn *pfn); 1041 extern void blk_queue_unprep_rq(struct request_queue *, unprep_rq_fn *ufn); 1042 extern void blk_queue_merge_bvec(struct request_queue *, merge_bvec_fn *); 1043 extern void blk_queue_dma_alignment(struct request_queue *, int); 1044 extern void blk_queue_update_dma_alignment(struct request_queue *, int); 1045 extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *); 1046 extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *); 1047 extern void blk_queue_rq_timeout(struct request_queue *, unsigned int); 1048 extern void blk_queue_flush(struct request_queue *q, unsigned int flush); 1049 extern void blk_queue_flush_queueable(struct request_queue *q, bool queueable); 1050 extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev); 1051 1052 extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *); 1053 extern int blk_bio_map_sg(struct request_queue *q, struct bio *bio, 1054 struct scatterlist *sglist); 1055 extern void blk_dump_rq_flags(struct request *, char *); 1056 extern long nr_blockdev_pages(void); 1057 1058 bool __must_check blk_get_queue(struct request_queue *); 1059 struct request_queue *blk_alloc_queue(gfp_t); 1060 struct request_queue *blk_alloc_queue_node(gfp_t, int); 1061 extern void blk_put_queue(struct request_queue *); 1062 1063 /* 1064 * block layer runtime pm functions 1065 */ 1066 #ifdef CONFIG_PM_RUNTIME 1067 extern void blk_pm_runtime_init(struct request_queue *q, struct device *dev); 1068 extern int blk_pre_runtime_suspend(struct request_queue *q); 1069 extern void blk_post_runtime_suspend(struct request_queue *q, int err); 1070 extern void blk_pre_runtime_resume(struct request_queue *q); 1071 extern void blk_post_runtime_resume(struct request_queue *q, int err); 1072 #else 1073 static inline void blk_pm_runtime_init(struct request_queue *q, 1074 struct device *dev) {} 1075 static inline int blk_pre_runtime_suspend(struct request_queue *q) 1076 { 1077 return -ENOSYS; 1078 } 1079 static inline void blk_post_runtime_suspend(struct request_queue *q, int err) {} 1080 static inline void blk_pre_runtime_resume(struct request_queue *q) {} 1081 static inline void blk_post_runtime_resume(struct request_queue *q, int err) {} 1082 #endif 1083 1084 /* 1085 * blk_plug permits building a queue of related requests by holding the I/O 1086 * fragments for a short period. This allows merging of sequential requests 1087 * into single larger request. As the requests are moved from a per-task list to 1088 * the device's request_queue in a batch, this results in improved scalability 1089 * as the lock contention for request_queue lock is reduced. 1090 * 1091 * It is ok not to disable preemption when adding the request to the plug list 1092 * or when attempting a merge, because blk_schedule_flush_list() will only flush 1093 * the plug list when the task sleeps by itself. For details, please see 1094 * schedule() where blk_schedule_flush_plug() is called. 1095 */ 1096 struct blk_plug { 1097 struct list_head list; /* requests */ 1098 struct list_head mq_list; /* blk-mq requests */ 1099 struct list_head cb_list; /* md requires an unplug callback */ 1100 }; 1101 #define BLK_MAX_REQUEST_COUNT 16 1102 1103 struct blk_plug_cb; 1104 typedef void (*blk_plug_cb_fn)(struct blk_plug_cb *, bool); 1105 struct blk_plug_cb { 1106 struct list_head list; 1107 blk_plug_cb_fn callback; 1108 void *data; 1109 }; 1110 extern struct blk_plug_cb *blk_check_plugged(blk_plug_cb_fn unplug, 1111 void *data, int size); 1112 extern void blk_start_plug(struct blk_plug *); 1113 extern void blk_finish_plug(struct blk_plug *); 1114 extern void blk_flush_plug_list(struct blk_plug *, bool); 1115 1116 static inline void blk_flush_plug(struct task_struct *tsk) 1117 { 1118 struct blk_plug *plug = tsk->plug; 1119 1120 if (plug) 1121 blk_flush_plug_list(plug, false); 1122 } 1123 1124 static inline void blk_schedule_flush_plug(struct task_struct *tsk) 1125 { 1126 struct blk_plug *plug = tsk->plug; 1127 1128 if (plug) 1129 blk_flush_plug_list(plug, true); 1130 } 1131 1132 static inline bool blk_needs_flush_plug(struct task_struct *tsk) 1133 { 1134 struct blk_plug *plug = tsk->plug; 1135 1136 return plug && 1137 (!list_empty(&plug->list) || 1138 !list_empty(&plug->mq_list) || 1139 !list_empty(&plug->cb_list)); 1140 } 1141 1142 /* 1143 * tag stuff 1144 */ 1145 #define blk_rq_tagged(rq) \ 1146 ((rq)->mq_ctx || ((rq)->cmd_flags & REQ_QUEUED)) 1147 extern int blk_queue_start_tag(struct request_queue *, struct request *); 1148 extern struct request *blk_queue_find_tag(struct request_queue *, int); 1149 extern void blk_queue_end_tag(struct request_queue *, struct request *); 1150 extern int blk_queue_init_tags(struct request_queue *, int, struct blk_queue_tag *); 1151 extern void blk_queue_free_tags(struct request_queue *); 1152 extern int blk_queue_resize_tags(struct request_queue *, int); 1153 extern void blk_queue_invalidate_tags(struct request_queue *); 1154 extern struct blk_queue_tag *blk_init_tags(int); 1155 extern void blk_free_tags(struct blk_queue_tag *); 1156 1157 static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt, 1158 int tag) 1159 { 1160 if (unlikely(bqt == NULL || tag >= bqt->real_max_depth)) 1161 return NULL; 1162 return bqt->tag_index[tag]; 1163 } 1164 1165 #define BLKDEV_DISCARD_SECURE 0x01 /* secure discard */ 1166 1167 extern int blkdev_issue_flush(struct block_device *, gfp_t, sector_t *); 1168 extern int blkdev_issue_discard(struct block_device *bdev, sector_t sector, 1169 sector_t nr_sects, gfp_t gfp_mask, unsigned long flags); 1170 extern int blkdev_issue_write_same(struct block_device *bdev, sector_t sector, 1171 sector_t nr_sects, gfp_t gfp_mask, struct page *page); 1172 extern int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector, 1173 sector_t nr_sects, gfp_t gfp_mask); 1174 static inline int sb_issue_discard(struct super_block *sb, sector_t block, 1175 sector_t nr_blocks, gfp_t gfp_mask, unsigned long flags) 1176 { 1177 return blkdev_issue_discard(sb->s_bdev, block << (sb->s_blocksize_bits - 9), 1178 nr_blocks << (sb->s_blocksize_bits - 9), 1179 gfp_mask, flags); 1180 } 1181 static inline int sb_issue_zeroout(struct super_block *sb, sector_t block, 1182 sector_t nr_blocks, gfp_t gfp_mask) 1183 { 1184 return blkdev_issue_zeroout(sb->s_bdev, 1185 block << (sb->s_blocksize_bits - 9), 1186 nr_blocks << (sb->s_blocksize_bits - 9), 1187 gfp_mask); 1188 } 1189 1190 extern int blk_verify_command(unsigned char *cmd, fmode_t has_write_perm); 1191 1192 enum blk_default_limits { 1193 BLK_MAX_SEGMENTS = 128, 1194 BLK_SAFE_MAX_SECTORS = 255, 1195 BLK_DEF_MAX_SECTORS = 1024, 1196 BLK_MAX_SEGMENT_SIZE = 65536, 1197 BLK_SEG_BOUNDARY_MASK = 0xFFFFFFFFUL, 1198 }; 1199 1200 #define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist) 1201 1202 static inline unsigned long queue_bounce_pfn(struct request_queue *q) 1203 { 1204 return q->limits.bounce_pfn; 1205 } 1206 1207 static inline unsigned long queue_segment_boundary(struct request_queue *q) 1208 { 1209 return q->limits.seg_boundary_mask; 1210 } 1211 1212 static inline unsigned int queue_max_sectors(struct request_queue *q) 1213 { 1214 return q->limits.max_sectors; 1215 } 1216 1217 static inline unsigned int queue_max_hw_sectors(struct request_queue *q) 1218 { 1219 return q->limits.max_hw_sectors; 1220 } 1221 1222 static inline unsigned short queue_max_segments(struct request_queue *q) 1223 { 1224 return q->limits.max_segments; 1225 } 1226 1227 static inline unsigned int queue_max_segment_size(struct request_queue *q) 1228 { 1229 return q->limits.max_segment_size; 1230 } 1231 1232 static inline unsigned short queue_logical_block_size(struct request_queue *q) 1233 { 1234 int retval = 512; 1235 1236 if (q && q->limits.logical_block_size) 1237 retval = q->limits.logical_block_size; 1238 1239 return retval; 1240 } 1241 1242 static inline unsigned short bdev_logical_block_size(struct block_device *bdev) 1243 { 1244 return queue_logical_block_size(bdev_get_queue(bdev)); 1245 } 1246 1247 static inline unsigned int queue_physical_block_size(struct request_queue *q) 1248 { 1249 return q->limits.physical_block_size; 1250 } 1251 1252 static inline unsigned int bdev_physical_block_size(struct block_device *bdev) 1253 { 1254 return queue_physical_block_size(bdev_get_queue(bdev)); 1255 } 1256 1257 static inline unsigned int queue_io_min(struct request_queue *q) 1258 { 1259 return q->limits.io_min; 1260 } 1261 1262 static inline int bdev_io_min(struct block_device *bdev) 1263 { 1264 return queue_io_min(bdev_get_queue(bdev)); 1265 } 1266 1267 static inline unsigned int queue_io_opt(struct request_queue *q) 1268 { 1269 return q->limits.io_opt; 1270 } 1271 1272 static inline int bdev_io_opt(struct block_device *bdev) 1273 { 1274 return queue_io_opt(bdev_get_queue(bdev)); 1275 } 1276 1277 static inline int queue_alignment_offset(struct request_queue *q) 1278 { 1279 if (q->limits.misaligned) 1280 return -1; 1281 1282 return q->limits.alignment_offset; 1283 } 1284 1285 static inline int queue_limit_alignment_offset(struct queue_limits *lim, sector_t sector) 1286 { 1287 unsigned int granularity = max(lim->physical_block_size, lim->io_min); 1288 unsigned int alignment = (sector << 9) & (granularity - 1); 1289 1290 return (granularity + lim->alignment_offset - alignment) 1291 & (granularity - 1); 1292 } 1293 1294 static inline int bdev_alignment_offset(struct block_device *bdev) 1295 { 1296 struct request_queue *q = bdev_get_queue(bdev); 1297 1298 if (q->limits.misaligned) 1299 return -1; 1300 1301 if (bdev != bdev->bd_contains) 1302 return bdev->bd_part->alignment_offset; 1303 1304 return q->limits.alignment_offset; 1305 } 1306 1307 static inline int queue_discard_alignment(struct request_queue *q) 1308 { 1309 if (q->limits.discard_misaligned) 1310 return -1; 1311 1312 return q->limits.discard_alignment; 1313 } 1314 1315 static inline int queue_limit_discard_alignment(struct queue_limits *lim, sector_t sector) 1316 { 1317 unsigned int alignment, granularity, offset; 1318 1319 if (!lim->max_discard_sectors) 1320 return 0; 1321 1322 /* Why are these in bytes, not sectors? */ 1323 alignment = lim->discard_alignment >> 9; 1324 granularity = lim->discard_granularity >> 9; 1325 if (!granularity) 1326 return 0; 1327 1328 /* Offset of the partition start in 'granularity' sectors */ 1329 offset = sector_div(sector, granularity); 1330 1331 /* And why do we do this modulus *again* in blkdev_issue_discard()? */ 1332 offset = (granularity + alignment - offset) % granularity; 1333 1334 /* Turn it back into bytes, gaah */ 1335 return offset << 9; 1336 } 1337 1338 static inline int bdev_discard_alignment(struct block_device *bdev) 1339 { 1340 struct request_queue *q = bdev_get_queue(bdev); 1341 1342 if (bdev != bdev->bd_contains) 1343 return bdev->bd_part->discard_alignment; 1344 1345 return q->limits.discard_alignment; 1346 } 1347 1348 static inline unsigned int queue_discard_zeroes_data(struct request_queue *q) 1349 { 1350 if (q->limits.max_discard_sectors && q->limits.discard_zeroes_data == 1) 1351 return 1; 1352 1353 return 0; 1354 } 1355 1356 static inline unsigned int bdev_discard_zeroes_data(struct block_device *bdev) 1357 { 1358 return queue_discard_zeroes_data(bdev_get_queue(bdev)); 1359 } 1360 1361 static inline unsigned int bdev_write_same(struct block_device *bdev) 1362 { 1363 struct request_queue *q = bdev_get_queue(bdev); 1364 1365 if (q) 1366 return q->limits.max_write_same_sectors; 1367 1368 return 0; 1369 } 1370 1371 static inline int queue_dma_alignment(struct request_queue *q) 1372 { 1373 return q ? q->dma_alignment : 511; 1374 } 1375 1376 static inline int blk_rq_aligned(struct request_queue *q, unsigned long addr, 1377 unsigned int len) 1378 { 1379 unsigned int alignment = queue_dma_alignment(q) | q->dma_pad_mask; 1380 return !(addr & alignment) && !(len & alignment); 1381 } 1382 1383 /* assumes size > 256 */ 1384 static inline unsigned int blksize_bits(unsigned int size) 1385 { 1386 unsigned int bits = 8; 1387 do { 1388 bits++; 1389 size >>= 1; 1390 } while (size > 256); 1391 return bits; 1392 } 1393 1394 static inline unsigned int block_size(struct block_device *bdev) 1395 { 1396 return bdev->bd_block_size; 1397 } 1398 1399 static inline bool queue_flush_queueable(struct request_queue *q) 1400 { 1401 return !q->flush_not_queueable; 1402 } 1403 1404 typedef struct {struct page *v;} Sector; 1405 1406 unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *); 1407 1408 static inline void put_dev_sector(Sector p) 1409 { 1410 page_cache_release(p.v); 1411 } 1412 1413 struct work_struct; 1414 int kblockd_schedule_work(struct work_struct *work); 1415 int kblockd_schedule_delayed_work(struct delayed_work *dwork, unsigned long delay); 1416 int kblockd_schedule_delayed_work_on(int cpu, struct delayed_work *dwork, unsigned long delay); 1417 1418 #ifdef CONFIG_BLK_CGROUP 1419 /* 1420 * This should not be using sched_clock(). A real patch is in progress 1421 * to fix this up, until that is in place we need to disable preemption 1422 * around sched_clock() in this function and set_io_start_time_ns(). 1423 */ 1424 static inline void set_start_time_ns(struct request *req) 1425 { 1426 preempt_disable(); 1427 req->start_time_ns = sched_clock(); 1428 preempt_enable(); 1429 } 1430 1431 static inline void set_io_start_time_ns(struct request *req) 1432 { 1433 preempt_disable(); 1434 req->io_start_time_ns = sched_clock(); 1435 preempt_enable(); 1436 } 1437 1438 static inline uint64_t rq_start_time_ns(struct request *req) 1439 { 1440 return req->start_time_ns; 1441 } 1442 1443 static inline uint64_t rq_io_start_time_ns(struct request *req) 1444 { 1445 return req->io_start_time_ns; 1446 } 1447 #else 1448 static inline void set_start_time_ns(struct request *req) {} 1449 static inline void set_io_start_time_ns(struct request *req) {} 1450 static inline uint64_t rq_start_time_ns(struct request *req) 1451 { 1452 return 0; 1453 } 1454 static inline uint64_t rq_io_start_time_ns(struct request *req) 1455 { 1456 return 0; 1457 } 1458 #endif 1459 1460 #define MODULE_ALIAS_BLOCKDEV(major,minor) \ 1461 MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor)) 1462 #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \ 1463 MODULE_ALIAS("block-major-" __stringify(major) "-*") 1464 1465 #if defined(CONFIG_BLK_DEV_INTEGRITY) 1466 1467 #define INTEGRITY_FLAG_READ 2 /* verify data integrity on read */ 1468 #define INTEGRITY_FLAG_WRITE 4 /* generate data integrity on write */ 1469 1470 struct blk_integrity_exchg { 1471 void *prot_buf; 1472 void *data_buf; 1473 sector_t sector; 1474 unsigned int data_size; 1475 unsigned short sector_size; 1476 const char *disk_name; 1477 }; 1478 1479 typedef void (integrity_gen_fn) (struct blk_integrity_exchg *); 1480 typedef int (integrity_vrfy_fn) (struct blk_integrity_exchg *); 1481 typedef void (integrity_set_tag_fn) (void *, void *, unsigned int); 1482 typedef void (integrity_get_tag_fn) (void *, void *, unsigned int); 1483 1484 struct blk_integrity { 1485 integrity_gen_fn *generate_fn; 1486 integrity_vrfy_fn *verify_fn; 1487 integrity_set_tag_fn *set_tag_fn; 1488 integrity_get_tag_fn *get_tag_fn; 1489 1490 unsigned short flags; 1491 unsigned short tuple_size; 1492 unsigned short sector_size; 1493 unsigned short tag_size; 1494 1495 const char *name; 1496 1497 struct kobject kobj; 1498 }; 1499 1500 extern bool blk_integrity_is_initialized(struct gendisk *); 1501 extern int blk_integrity_register(struct gendisk *, struct blk_integrity *); 1502 extern void blk_integrity_unregister(struct gendisk *); 1503 extern int blk_integrity_compare(struct gendisk *, struct gendisk *); 1504 extern int blk_rq_map_integrity_sg(struct request_queue *, struct bio *, 1505 struct scatterlist *); 1506 extern int blk_rq_count_integrity_sg(struct request_queue *, struct bio *); 1507 extern int blk_integrity_merge_rq(struct request_queue *, struct request *, 1508 struct request *); 1509 extern int blk_integrity_merge_bio(struct request_queue *, struct request *, 1510 struct bio *); 1511 1512 static inline 1513 struct blk_integrity *bdev_get_integrity(struct block_device *bdev) 1514 { 1515 return bdev->bd_disk->integrity; 1516 } 1517 1518 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk) 1519 { 1520 return disk->integrity; 1521 } 1522 1523 static inline int blk_integrity_rq(struct request *rq) 1524 { 1525 if (rq->bio == NULL) 1526 return 0; 1527 1528 return bio_integrity(rq->bio); 1529 } 1530 1531 static inline void blk_queue_max_integrity_segments(struct request_queue *q, 1532 unsigned int segs) 1533 { 1534 q->limits.max_integrity_segments = segs; 1535 } 1536 1537 static inline unsigned short 1538 queue_max_integrity_segments(struct request_queue *q) 1539 { 1540 return q->limits.max_integrity_segments; 1541 } 1542 1543 #else /* CONFIG_BLK_DEV_INTEGRITY */ 1544 1545 struct bio; 1546 struct block_device; 1547 struct gendisk; 1548 struct blk_integrity; 1549 1550 static inline int blk_integrity_rq(struct request *rq) 1551 { 1552 return 0; 1553 } 1554 static inline int blk_rq_count_integrity_sg(struct request_queue *q, 1555 struct bio *b) 1556 { 1557 return 0; 1558 } 1559 static inline int blk_rq_map_integrity_sg(struct request_queue *q, 1560 struct bio *b, 1561 struct scatterlist *s) 1562 { 1563 return 0; 1564 } 1565 static inline struct blk_integrity *bdev_get_integrity(struct block_device *b) 1566 { 1567 return 0; 1568 } 1569 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk) 1570 { 1571 return NULL; 1572 } 1573 static inline int blk_integrity_compare(struct gendisk *a, struct gendisk *b) 1574 { 1575 return 0; 1576 } 1577 static inline int blk_integrity_register(struct gendisk *d, 1578 struct blk_integrity *b) 1579 { 1580 return 0; 1581 } 1582 static inline void blk_integrity_unregister(struct gendisk *d) 1583 { 1584 } 1585 static inline void blk_queue_max_integrity_segments(struct request_queue *q, 1586 unsigned int segs) 1587 { 1588 } 1589 static inline unsigned short queue_max_integrity_segments(struct request_queue *q) 1590 { 1591 return 0; 1592 } 1593 static inline int blk_integrity_merge_rq(struct request_queue *rq, 1594 struct request *r1, 1595 struct request *r2) 1596 { 1597 return 0; 1598 } 1599 static inline int blk_integrity_merge_bio(struct request_queue *rq, 1600 struct request *r, 1601 struct bio *b) 1602 { 1603 return 0; 1604 } 1605 static inline bool blk_integrity_is_initialized(struct gendisk *g) 1606 { 1607 return 0; 1608 } 1609 1610 #endif /* CONFIG_BLK_DEV_INTEGRITY */ 1611 1612 struct block_device_operations { 1613 int (*open) (struct block_device *, fmode_t); 1614 void (*release) (struct gendisk *, fmode_t); 1615 int (*rw_page)(struct block_device *, sector_t, struct page *, int rw); 1616 int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long); 1617 int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long); 1618 int (*direct_access) (struct block_device *, sector_t, 1619 void **, unsigned long *); 1620 unsigned int (*check_events) (struct gendisk *disk, 1621 unsigned int clearing); 1622 /* ->media_changed() is DEPRECATED, use ->check_events() instead */ 1623 int (*media_changed) (struct gendisk *); 1624 void (*unlock_native_capacity) (struct gendisk *); 1625 int (*revalidate_disk) (struct gendisk *); 1626 int (*getgeo)(struct block_device *, struct hd_geometry *); 1627 /* this callback is with swap_lock and sometimes page table lock held */ 1628 void (*swap_slot_free_notify) (struct block_device *, unsigned long); 1629 struct module *owner; 1630 }; 1631 1632 extern int __blkdev_driver_ioctl(struct block_device *, fmode_t, unsigned int, 1633 unsigned long); 1634 extern int bdev_read_page(struct block_device *, sector_t, struct page *); 1635 extern int bdev_write_page(struct block_device *, sector_t, struct page *, 1636 struct writeback_control *); 1637 #else /* CONFIG_BLOCK */ 1638 1639 struct block_device; 1640 1641 /* 1642 * stubs for when the block layer is configured out 1643 */ 1644 #define buffer_heads_over_limit 0 1645 1646 static inline long nr_blockdev_pages(void) 1647 { 1648 return 0; 1649 } 1650 1651 struct blk_plug { 1652 }; 1653 1654 static inline void blk_start_plug(struct blk_plug *plug) 1655 { 1656 } 1657 1658 static inline void blk_finish_plug(struct blk_plug *plug) 1659 { 1660 } 1661 1662 static inline void blk_flush_plug(struct task_struct *task) 1663 { 1664 } 1665 1666 static inline void blk_schedule_flush_plug(struct task_struct *task) 1667 { 1668 } 1669 1670 1671 static inline bool blk_needs_flush_plug(struct task_struct *tsk) 1672 { 1673 return false; 1674 } 1675 1676 static inline int blkdev_issue_flush(struct block_device *bdev, gfp_t gfp_mask, 1677 sector_t *error_sector) 1678 { 1679 return 0; 1680 } 1681 1682 #endif /* CONFIG_BLOCK */ 1683 1684 #endif 1685