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