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. 112 */ 113 void *elevator_private; 114 void *elevator_private2; 115 void *elevator_private3; 116 117 struct gendisk *rq_disk; 118 unsigned long start_time; 119 #ifdef CONFIG_BLK_CGROUP 120 unsigned long long start_time_ns; 121 unsigned long long io_start_time_ns; /* when passed to hardware */ 122 #endif 123 /* Number of scatter-gather DMA addr+len pairs after 124 * physical address coalescing is performed. 125 */ 126 unsigned short nr_phys_segments; 127 128 unsigned short ioprio; 129 130 int ref_count; 131 132 void *special; /* opaque pointer available for LLD use */ 133 char *buffer; /* kaddr of the current segment if available */ 134 135 int tag; 136 int errors; 137 138 /* 139 * when request is used as a packet command carrier 140 */ 141 unsigned char __cmd[BLK_MAX_CDB]; 142 unsigned char *cmd; 143 unsigned short cmd_len; 144 145 unsigned int extra_len; /* length of alignment and padding */ 146 unsigned int sense_len; 147 unsigned int resid_len; /* residual count */ 148 void *sense; 149 150 unsigned long deadline; 151 struct list_head timeout_list; 152 unsigned int timeout; 153 int retries; 154 155 /* 156 * completion callback. 157 */ 158 rq_end_io_fn *end_io; 159 void *end_io_data; 160 161 /* for bidi */ 162 struct request *next_rq; 163 }; 164 165 static inline unsigned short req_get_ioprio(struct request *req) 166 { 167 return req->ioprio; 168 } 169 170 /* 171 * State information carried for REQ_TYPE_PM_SUSPEND and REQ_TYPE_PM_RESUME 172 * requests. Some step values could eventually be made generic. 173 */ 174 struct request_pm_state 175 { 176 /* PM state machine step value, currently driver specific */ 177 int pm_step; 178 /* requested PM state value (S1, S2, S3, S4, ...) */ 179 u32 pm_state; 180 void* data; /* for driver use */ 181 }; 182 183 #include <linux/elevator.h> 184 185 typedef void (request_fn_proc) (struct request_queue *q); 186 typedef int (make_request_fn) (struct request_queue *q, struct bio *bio); 187 typedef int (prep_rq_fn) (struct request_queue *, struct request *); 188 typedef void (unprep_rq_fn) (struct request_queue *, struct request *); 189 typedef void (unplug_fn) (struct request_queue *); 190 191 struct bio_vec; 192 struct bvec_merge_data { 193 struct block_device *bi_bdev; 194 sector_t bi_sector; 195 unsigned bi_size; 196 unsigned long bi_rw; 197 }; 198 typedef int (merge_bvec_fn) (struct request_queue *, struct bvec_merge_data *, 199 struct bio_vec *); 200 typedef void (softirq_done_fn)(struct request *); 201 typedef int (dma_drain_needed_fn)(struct request *); 202 typedef int (lld_busy_fn) (struct request_queue *q); 203 204 enum blk_eh_timer_return { 205 BLK_EH_NOT_HANDLED, 206 BLK_EH_HANDLED, 207 BLK_EH_RESET_TIMER, 208 }; 209 210 typedef enum blk_eh_timer_return (rq_timed_out_fn)(struct request *); 211 212 enum blk_queue_state { 213 Queue_down, 214 Queue_up, 215 }; 216 217 struct blk_queue_tag { 218 struct request **tag_index; /* map of busy tags */ 219 unsigned long *tag_map; /* bit map of free/busy tags */ 220 int busy; /* current depth */ 221 int max_depth; /* what we will send to device */ 222 int real_max_depth; /* what the array can hold */ 223 atomic_t refcnt; /* map can be shared */ 224 }; 225 226 #define BLK_SCSI_MAX_CMDS (256) 227 #define BLK_SCSI_CMD_PER_LONG (BLK_SCSI_MAX_CMDS / (sizeof(long) * 8)) 228 229 struct queue_limits { 230 unsigned long bounce_pfn; 231 unsigned long seg_boundary_mask; 232 233 unsigned int max_hw_sectors; 234 unsigned int max_sectors; 235 unsigned int max_segment_size; 236 unsigned int physical_block_size; 237 unsigned int alignment_offset; 238 unsigned int io_min; 239 unsigned int io_opt; 240 unsigned int max_discard_sectors; 241 unsigned int discard_granularity; 242 unsigned int discard_alignment; 243 244 unsigned short logical_block_size; 245 unsigned short max_segments; 246 247 unsigned char misaligned; 248 unsigned char discard_misaligned; 249 unsigned char no_cluster; 250 signed char discard_zeroes_data; 251 }; 252 253 struct request_queue 254 { 255 /* 256 * Together with queue_head for cacheline sharing 257 */ 258 struct list_head queue_head; 259 struct request *last_merge; 260 struct elevator_queue *elevator; 261 262 /* 263 * the queue request freelist, one for reads and one for writes 264 */ 265 struct request_list rq; 266 267 request_fn_proc *request_fn; 268 make_request_fn *make_request_fn; 269 prep_rq_fn *prep_rq_fn; 270 unprep_rq_fn *unprep_rq_fn; 271 unplug_fn *unplug_fn; 272 merge_bvec_fn *merge_bvec_fn; 273 softirq_done_fn *softirq_done_fn; 274 rq_timed_out_fn *rq_timed_out_fn; 275 dma_drain_needed_fn *dma_drain_needed; 276 lld_busy_fn *lld_busy_fn; 277 278 /* 279 * Dispatch queue sorting 280 */ 281 sector_t end_sector; 282 struct request *boundary_rq; 283 284 /* 285 * Auto-unplugging state 286 */ 287 struct timer_list unplug_timer; 288 int unplug_thresh; /* After this many requests */ 289 unsigned long unplug_delay; /* After this many jiffies */ 290 struct work_struct unplug_work; 291 292 struct backing_dev_info backing_dev_info; 293 294 /* 295 * The queue owner gets to use this for whatever they like. 296 * ll_rw_blk doesn't touch it. 297 */ 298 void *queuedata; 299 300 /* 301 * queue needs bounce pages for pages above this limit 302 */ 303 gfp_t bounce_gfp; 304 305 /* 306 * various queue flags, see QUEUE_* below 307 */ 308 unsigned long queue_flags; 309 310 /* 311 * protects queue structures from reentrancy. ->__queue_lock should 312 * _never_ be used directly, it is queue private. always use 313 * ->queue_lock. 314 */ 315 spinlock_t __queue_lock; 316 spinlock_t *queue_lock; 317 318 /* 319 * queue kobject 320 */ 321 struct kobject kobj; 322 323 /* 324 * queue settings 325 */ 326 unsigned long nr_requests; /* Max # of requests */ 327 unsigned int nr_congestion_on; 328 unsigned int nr_congestion_off; 329 unsigned int nr_batching; 330 331 void *dma_drain_buffer; 332 unsigned int dma_drain_size; 333 unsigned int dma_pad_mask; 334 unsigned int dma_alignment; 335 336 struct blk_queue_tag *queue_tags; 337 struct list_head tag_busy_list; 338 339 unsigned int nr_sorted; 340 unsigned int in_flight[2]; 341 342 unsigned int rq_timeout; 343 struct timer_list timeout; 344 struct list_head timeout_list; 345 346 struct queue_limits limits; 347 348 /* 349 * sg stuff 350 */ 351 unsigned int sg_timeout; 352 unsigned int sg_reserved_size; 353 int node; 354 #ifdef CONFIG_BLK_DEV_IO_TRACE 355 struct blk_trace *blk_trace; 356 #endif 357 /* 358 * reserved for flush operations 359 */ 360 unsigned int ordered, next_ordered, ordseq; 361 int orderr, ordcolor; 362 struct request pre_flush_rq, bar_rq, post_flush_rq; 363 struct request *orig_bar_rq; 364 365 struct mutex sysfs_lock; 366 367 #if defined(CONFIG_BLK_DEV_BSG) 368 struct bsg_class_device bsg_dev; 369 #endif 370 }; 371 372 #define QUEUE_FLAG_CLUSTER 0 /* cluster several segments into 1 */ 373 #define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */ 374 #define QUEUE_FLAG_STOPPED 2 /* queue is stopped */ 375 #define QUEUE_FLAG_SYNCFULL 3 /* read queue has been filled */ 376 #define QUEUE_FLAG_ASYNCFULL 4 /* write queue has been filled */ 377 #define QUEUE_FLAG_DEAD 5 /* queue being torn down */ 378 #define QUEUE_FLAG_REENTER 6 /* Re-entrancy avoidance */ 379 #define QUEUE_FLAG_PLUGGED 7 /* queue is plugged */ 380 #define QUEUE_FLAG_ELVSWITCH 8 /* don't use elevator, just do FIFO */ 381 #define QUEUE_FLAG_BIDI 9 /* queue supports bidi requests */ 382 #define QUEUE_FLAG_NOMERGES 10 /* disable merge attempts */ 383 #define QUEUE_FLAG_SAME_COMP 11 /* force complete on same CPU */ 384 #define QUEUE_FLAG_FAIL_IO 12 /* fake timeout */ 385 #define QUEUE_FLAG_STACKABLE 13 /* supports request stacking */ 386 #define QUEUE_FLAG_NONROT 14 /* non-rotational device (SSD) */ 387 #define QUEUE_FLAG_VIRT QUEUE_FLAG_NONROT /* paravirt device */ 388 #define QUEUE_FLAG_IO_STAT 15 /* do IO stats */ 389 #define QUEUE_FLAG_DISCARD 16 /* supports DISCARD */ 390 #define QUEUE_FLAG_NOXMERGES 17 /* No extended merges */ 391 #define QUEUE_FLAG_ADD_RANDOM 18 /* Contributes to random pool */ 392 393 #define QUEUE_FLAG_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \ 394 (1 << QUEUE_FLAG_CLUSTER) | \ 395 (1 << QUEUE_FLAG_STACKABLE) | \ 396 (1 << QUEUE_FLAG_SAME_COMP) | \ 397 (1 << QUEUE_FLAG_ADD_RANDOM)) 398 399 static inline int queue_is_locked(struct request_queue *q) 400 { 401 #ifdef CONFIG_SMP 402 spinlock_t *lock = q->queue_lock; 403 return lock && spin_is_locked(lock); 404 #else 405 return 1; 406 #endif 407 } 408 409 static inline void queue_flag_set_unlocked(unsigned int flag, 410 struct request_queue *q) 411 { 412 __set_bit(flag, &q->queue_flags); 413 } 414 415 static inline int queue_flag_test_and_clear(unsigned int flag, 416 struct request_queue *q) 417 { 418 WARN_ON_ONCE(!queue_is_locked(q)); 419 420 if (test_bit(flag, &q->queue_flags)) { 421 __clear_bit(flag, &q->queue_flags); 422 return 1; 423 } 424 425 return 0; 426 } 427 428 static inline int queue_flag_test_and_set(unsigned int flag, 429 struct request_queue *q) 430 { 431 WARN_ON_ONCE(!queue_is_locked(q)); 432 433 if (!test_bit(flag, &q->queue_flags)) { 434 __set_bit(flag, &q->queue_flags); 435 return 0; 436 } 437 438 return 1; 439 } 440 441 static inline void queue_flag_set(unsigned int flag, struct request_queue *q) 442 { 443 WARN_ON_ONCE(!queue_is_locked(q)); 444 __set_bit(flag, &q->queue_flags); 445 } 446 447 static inline void queue_flag_clear_unlocked(unsigned int flag, 448 struct request_queue *q) 449 { 450 __clear_bit(flag, &q->queue_flags); 451 } 452 453 static inline int queue_in_flight(struct request_queue *q) 454 { 455 return q->in_flight[0] + q->in_flight[1]; 456 } 457 458 static inline void queue_flag_clear(unsigned int flag, struct request_queue *q) 459 { 460 WARN_ON_ONCE(!queue_is_locked(q)); 461 __clear_bit(flag, &q->queue_flags); 462 } 463 464 enum { 465 /* 466 * Hardbarrier is supported with one of the following methods. 467 * 468 * NONE : hardbarrier unsupported 469 * DRAIN : ordering by draining is enough 470 * DRAIN_FLUSH : ordering by draining w/ pre and post flushes 471 * DRAIN_FUA : ordering by draining w/ pre flush and FUA write 472 * TAG : ordering by tag is enough 473 * TAG_FLUSH : ordering by tag w/ pre and post flushes 474 * TAG_FUA : ordering by tag w/ pre flush and FUA write 475 */ 476 QUEUE_ORDERED_BY_DRAIN = 0x01, 477 QUEUE_ORDERED_BY_TAG = 0x02, 478 QUEUE_ORDERED_DO_PREFLUSH = 0x10, 479 QUEUE_ORDERED_DO_BAR = 0x20, 480 QUEUE_ORDERED_DO_POSTFLUSH = 0x40, 481 QUEUE_ORDERED_DO_FUA = 0x80, 482 483 QUEUE_ORDERED_NONE = 0x00, 484 485 QUEUE_ORDERED_DRAIN = QUEUE_ORDERED_BY_DRAIN | 486 QUEUE_ORDERED_DO_BAR, 487 QUEUE_ORDERED_DRAIN_FLUSH = QUEUE_ORDERED_DRAIN | 488 QUEUE_ORDERED_DO_PREFLUSH | 489 QUEUE_ORDERED_DO_POSTFLUSH, 490 QUEUE_ORDERED_DRAIN_FUA = QUEUE_ORDERED_DRAIN | 491 QUEUE_ORDERED_DO_PREFLUSH | 492 QUEUE_ORDERED_DO_FUA, 493 494 QUEUE_ORDERED_TAG = QUEUE_ORDERED_BY_TAG | 495 QUEUE_ORDERED_DO_BAR, 496 QUEUE_ORDERED_TAG_FLUSH = QUEUE_ORDERED_TAG | 497 QUEUE_ORDERED_DO_PREFLUSH | 498 QUEUE_ORDERED_DO_POSTFLUSH, 499 QUEUE_ORDERED_TAG_FUA = QUEUE_ORDERED_TAG | 500 QUEUE_ORDERED_DO_PREFLUSH | 501 QUEUE_ORDERED_DO_FUA, 502 503 /* 504 * Ordered operation sequence 505 */ 506 QUEUE_ORDSEQ_STARTED = 0x01, /* flushing in progress */ 507 QUEUE_ORDSEQ_DRAIN = 0x02, /* waiting for the queue to be drained */ 508 QUEUE_ORDSEQ_PREFLUSH = 0x04, /* pre-flushing in progress */ 509 QUEUE_ORDSEQ_BAR = 0x08, /* original barrier req in progress */ 510 QUEUE_ORDSEQ_POSTFLUSH = 0x10, /* post-flushing in progress */ 511 QUEUE_ORDSEQ_DONE = 0x20, 512 }; 513 514 #define blk_queue_plugged(q) test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags) 515 #define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags) 516 #define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags) 517 #define blk_queue_nomerges(q) test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags) 518 #define blk_queue_noxmerges(q) \ 519 test_bit(QUEUE_FLAG_NOXMERGES, &(q)->queue_flags) 520 #define blk_queue_nonrot(q) test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags) 521 #define blk_queue_io_stat(q) test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags) 522 #define blk_queue_add_random(q) test_bit(QUEUE_FLAG_ADD_RANDOM, &(q)->queue_flags) 523 #define blk_queue_flushing(q) ((q)->ordseq) 524 #define blk_queue_stackable(q) \ 525 test_bit(QUEUE_FLAG_STACKABLE, &(q)->queue_flags) 526 #define blk_queue_discard(q) test_bit(QUEUE_FLAG_DISCARD, &(q)->queue_flags) 527 528 #define blk_noretry_request(rq) \ 529 ((rq)->cmd_flags & (REQ_FAILFAST_DEV|REQ_FAILFAST_TRANSPORT| \ 530 REQ_FAILFAST_DRIVER)) 531 532 #define blk_account_rq(rq) \ 533 (((rq)->cmd_flags & REQ_STARTED) && \ 534 ((rq)->cmd_type == REQ_TYPE_FS || \ 535 ((rq)->cmd_flags & REQ_DISCARD))) 536 537 #define blk_pm_request(rq) \ 538 ((rq)->cmd_type == REQ_TYPE_PM_SUSPEND || \ 539 (rq)->cmd_type == REQ_TYPE_PM_RESUME) 540 541 #define blk_rq_cpu_valid(rq) ((rq)->cpu != -1) 542 #define blk_bidi_rq(rq) ((rq)->next_rq != NULL) 543 /* rq->queuelist of dequeued request must be list_empty() */ 544 #define blk_queued_rq(rq) (!list_empty(&(rq)->queuelist)) 545 546 #define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist) 547 548 #define rq_data_dir(rq) ((rq)->cmd_flags & 1) 549 550 /* 551 * We regard a request as sync, if either a read or a sync write 552 */ 553 static inline bool rw_is_sync(unsigned int rw_flags) 554 { 555 return !(rw_flags & REQ_WRITE) || (rw_flags & REQ_SYNC); 556 } 557 558 static inline bool rq_is_sync(struct request *rq) 559 { 560 return rw_is_sync(rq->cmd_flags); 561 } 562 563 static inline int blk_queue_full(struct request_queue *q, int sync) 564 { 565 if (sync) 566 return test_bit(QUEUE_FLAG_SYNCFULL, &q->queue_flags); 567 return test_bit(QUEUE_FLAG_ASYNCFULL, &q->queue_flags); 568 } 569 570 static inline void blk_set_queue_full(struct request_queue *q, int sync) 571 { 572 if (sync) 573 queue_flag_set(QUEUE_FLAG_SYNCFULL, q); 574 else 575 queue_flag_set(QUEUE_FLAG_ASYNCFULL, q); 576 } 577 578 static inline void blk_clear_queue_full(struct request_queue *q, int sync) 579 { 580 if (sync) 581 queue_flag_clear(QUEUE_FLAG_SYNCFULL, q); 582 else 583 queue_flag_clear(QUEUE_FLAG_ASYNCFULL, q); 584 } 585 586 587 /* 588 * mergeable request must not have _NOMERGE or _BARRIER bit set, nor may 589 * it already be started by driver. 590 */ 591 #define RQ_NOMERGE_FLAGS \ 592 (REQ_NOMERGE | REQ_STARTED | REQ_HARDBARRIER | REQ_SOFTBARRIER) 593 #define rq_mergeable(rq) \ 594 (!((rq)->cmd_flags & RQ_NOMERGE_FLAGS) && \ 595 (((rq)->cmd_flags & REQ_DISCARD) || \ 596 (rq)->cmd_type == REQ_TYPE_FS)) 597 598 /* 599 * q->prep_rq_fn return values 600 */ 601 #define BLKPREP_OK 0 /* serve it */ 602 #define BLKPREP_KILL 1 /* fatal error, kill */ 603 #define BLKPREP_DEFER 2 /* leave on queue */ 604 605 extern unsigned long blk_max_low_pfn, blk_max_pfn; 606 607 /* 608 * standard bounce addresses: 609 * 610 * BLK_BOUNCE_HIGH : bounce all highmem pages 611 * BLK_BOUNCE_ANY : don't bounce anything 612 * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary 613 */ 614 615 #if BITS_PER_LONG == 32 616 #define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT) 617 #else 618 #define BLK_BOUNCE_HIGH -1ULL 619 #endif 620 #define BLK_BOUNCE_ANY (-1ULL) 621 #define BLK_BOUNCE_ISA (DMA_BIT_MASK(24)) 622 623 /* 624 * default timeout for SG_IO if none specified 625 */ 626 #define BLK_DEFAULT_SG_TIMEOUT (60 * HZ) 627 #define BLK_MIN_SG_TIMEOUT (7 * HZ) 628 629 #ifdef CONFIG_BOUNCE 630 extern int init_emergency_isa_pool(void); 631 extern void blk_queue_bounce(struct request_queue *q, struct bio **bio); 632 #else 633 static inline int init_emergency_isa_pool(void) 634 { 635 return 0; 636 } 637 static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio) 638 { 639 } 640 #endif /* CONFIG_MMU */ 641 642 struct rq_map_data { 643 struct page **pages; 644 int page_order; 645 int nr_entries; 646 unsigned long offset; 647 int null_mapped; 648 int from_user; 649 }; 650 651 struct req_iterator { 652 int i; 653 struct bio *bio; 654 }; 655 656 /* This should not be used directly - use rq_for_each_segment */ 657 #define for_each_bio(_bio) \ 658 for (; _bio; _bio = _bio->bi_next) 659 #define __rq_for_each_bio(_bio, rq) \ 660 if ((rq->bio)) \ 661 for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next) 662 663 #define rq_for_each_segment(bvl, _rq, _iter) \ 664 __rq_for_each_bio(_iter.bio, _rq) \ 665 bio_for_each_segment(bvl, _iter.bio, _iter.i) 666 667 #define rq_iter_last(rq, _iter) \ 668 (_iter.bio->bi_next == NULL && _iter.i == _iter.bio->bi_vcnt-1) 669 670 #ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 671 # error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform" 672 #endif 673 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 674 extern void rq_flush_dcache_pages(struct request *rq); 675 #else 676 static inline void rq_flush_dcache_pages(struct request *rq) 677 { 678 } 679 #endif 680 681 extern int blk_register_queue(struct gendisk *disk); 682 extern void blk_unregister_queue(struct gendisk *disk); 683 extern void register_disk(struct gendisk *dev); 684 extern void generic_make_request(struct bio *bio); 685 extern void blk_rq_init(struct request_queue *q, struct request *rq); 686 extern void blk_put_request(struct request *); 687 extern void __blk_put_request(struct request_queue *, struct request *); 688 extern struct request *blk_get_request(struct request_queue *, int, gfp_t); 689 extern struct request *blk_make_request(struct request_queue *, struct bio *, 690 gfp_t); 691 extern void blk_insert_request(struct request_queue *, struct request *, int, void *); 692 extern void blk_requeue_request(struct request_queue *, struct request *); 693 extern void blk_add_request_payload(struct request *rq, struct page *page, 694 unsigned int len); 695 extern int blk_rq_check_limits(struct request_queue *q, struct request *rq); 696 extern int blk_lld_busy(struct request_queue *q); 697 extern int blk_rq_prep_clone(struct request *rq, struct request *rq_src, 698 struct bio_set *bs, gfp_t gfp_mask, 699 int (*bio_ctr)(struct bio *, struct bio *, void *), 700 void *data); 701 extern void blk_rq_unprep_clone(struct request *rq); 702 extern int blk_insert_cloned_request(struct request_queue *q, 703 struct request *rq); 704 extern void blk_plug_device(struct request_queue *); 705 extern void blk_plug_device_unlocked(struct request_queue *); 706 extern int blk_remove_plug(struct request_queue *); 707 extern void blk_recount_segments(struct request_queue *, struct bio *); 708 extern int scsi_cmd_ioctl(struct request_queue *, struct gendisk *, fmode_t, 709 unsigned int, void __user *); 710 extern int sg_scsi_ioctl(struct request_queue *, struct gendisk *, fmode_t, 711 struct scsi_ioctl_command __user *); 712 713 /* 714 * A queue has just exitted congestion. Note this in the global counter of 715 * congested queues, and wake up anyone who was waiting for requests to be 716 * put back. 717 */ 718 static inline void blk_clear_queue_congested(struct request_queue *q, int sync) 719 { 720 clear_bdi_congested(&q->backing_dev_info, sync); 721 } 722 723 /* 724 * A queue has just entered congestion. Flag that in the queue's VM-visible 725 * state flags and increment the global gounter of congested queues. 726 */ 727 static inline void blk_set_queue_congested(struct request_queue *q, int sync) 728 { 729 set_bdi_congested(&q->backing_dev_info, sync); 730 } 731 732 extern void blk_start_queue(struct request_queue *q); 733 extern void blk_stop_queue(struct request_queue *q); 734 extern void blk_sync_queue(struct request_queue *q); 735 extern void __blk_stop_queue(struct request_queue *q); 736 extern void __blk_run_queue(struct request_queue *); 737 extern void blk_run_queue(struct request_queue *); 738 extern int blk_rq_map_user(struct request_queue *, struct request *, 739 struct rq_map_data *, void __user *, unsigned long, 740 gfp_t); 741 extern int blk_rq_unmap_user(struct bio *); 742 extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, unsigned int, gfp_t); 743 extern int blk_rq_map_user_iov(struct request_queue *, struct request *, 744 struct rq_map_data *, struct sg_iovec *, int, 745 unsigned int, gfp_t); 746 extern int blk_execute_rq(struct request_queue *, struct gendisk *, 747 struct request *, int); 748 extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *, 749 struct request *, int, rq_end_io_fn *); 750 extern void blk_unplug(struct request_queue *q); 751 752 static inline struct request_queue *bdev_get_queue(struct block_device *bdev) 753 { 754 return bdev->bd_disk->queue; 755 } 756 757 /* 758 * blk_rq_pos() : the current sector 759 * blk_rq_bytes() : bytes left in the entire request 760 * blk_rq_cur_bytes() : bytes left in the current segment 761 * blk_rq_err_bytes() : bytes left till the next error boundary 762 * blk_rq_sectors() : sectors left in the entire request 763 * blk_rq_cur_sectors() : sectors left in the current segment 764 */ 765 static inline sector_t blk_rq_pos(const struct request *rq) 766 { 767 return rq->__sector; 768 } 769 770 static inline unsigned int blk_rq_bytes(const struct request *rq) 771 { 772 return rq->__data_len; 773 } 774 775 static inline int blk_rq_cur_bytes(const struct request *rq) 776 { 777 return rq->bio ? bio_cur_bytes(rq->bio) : 0; 778 } 779 780 extern unsigned int blk_rq_err_bytes(const struct request *rq); 781 782 static inline unsigned int blk_rq_sectors(const struct request *rq) 783 { 784 return blk_rq_bytes(rq) >> 9; 785 } 786 787 static inline unsigned int blk_rq_cur_sectors(const struct request *rq) 788 { 789 return blk_rq_cur_bytes(rq) >> 9; 790 } 791 792 /* 793 * Request issue related functions. 794 */ 795 extern struct request *blk_peek_request(struct request_queue *q); 796 extern void blk_start_request(struct request *rq); 797 extern struct request *blk_fetch_request(struct request_queue *q); 798 799 /* 800 * Request completion related functions. 801 * 802 * blk_update_request() completes given number of bytes and updates 803 * the request without completing it. 804 * 805 * blk_end_request() and friends. __blk_end_request() must be called 806 * with the request queue spinlock acquired. 807 * 808 * Several drivers define their own end_request and call 809 * blk_end_request() for parts of the original function. 810 * This prevents code duplication in drivers. 811 */ 812 extern bool blk_update_request(struct request *rq, int error, 813 unsigned int nr_bytes); 814 extern bool blk_end_request(struct request *rq, int error, 815 unsigned int nr_bytes); 816 extern void blk_end_request_all(struct request *rq, int error); 817 extern bool blk_end_request_cur(struct request *rq, int error); 818 extern bool blk_end_request_err(struct request *rq, int error); 819 extern bool __blk_end_request(struct request *rq, int error, 820 unsigned int nr_bytes); 821 extern void __blk_end_request_all(struct request *rq, int error); 822 extern bool __blk_end_request_cur(struct request *rq, int error); 823 extern bool __blk_end_request_err(struct request *rq, int error); 824 825 extern void blk_complete_request(struct request *); 826 extern void __blk_complete_request(struct request *); 827 extern void blk_abort_request(struct request *); 828 extern void blk_abort_queue(struct request_queue *); 829 extern void blk_unprep_request(struct request *); 830 831 /* 832 * Access functions for manipulating queue properties 833 */ 834 extern struct request_queue *blk_init_queue_node(request_fn_proc *rfn, 835 spinlock_t *lock, int node_id); 836 extern struct request_queue *blk_init_allocated_queue_node(struct request_queue *, 837 request_fn_proc *, 838 spinlock_t *, int node_id); 839 extern struct request_queue *blk_init_queue(request_fn_proc *, spinlock_t *); 840 extern struct request_queue *blk_init_allocated_queue(struct request_queue *, 841 request_fn_proc *, spinlock_t *); 842 extern void blk_cleanup_queue(struct request_queue *); 843 extern void blk_queue_make_request(struct request_queue *, make_request_fn *); 844 extern void blk_queue_bounce_limit(struct request_queue *, u64); 845 extern void blk_queue_max_hw_sectors(struct request_queue *, unsigned int); 846 extern void blk_queue_max_segments(struct request_queue *, unsigned short); 847 extern void blk_queue_max_segment_size(struct request_queue *, unsigned int); 848 extern void blk_queue_max_discard_sectors(struct request_queue *q, 849 unsigned int max_discard_sectors); 850 extern void blk_queue_logical_block_size(struct request_queue *, unsigned short); 851 extern void blk_queue_physical_block_size(struct request_queue *, unsigned short); 852 extern void blk_queue_alignment_offset(struct request_queue *q, 853 unsigned int alignment); 854 extern void blk_limits_io_min(struct queue_limits *limits, unsigned int min); 855 extern void blk_queue_io_min(struct request_queue *q, unsigned int min); 856 extern void blk_limits_io_opt(struct queue_limits *limits, unsigned int opt); 857 extern void blk_queue_io_opt(struct request_queue *q, unsigned int opt); 858 extern void blk_set_default_limits(struct queue_limits *lim); 859 extern int blk_stack_limits(struct queue_limits *t, struct queue_limits *b, 860 sector_t offset); 861 extern int bdev_stack_limits(struct queue_limits *t, struct block_device *bdev, 862 sector_t offset); 863 extern void disk_stack_limits(struct gendisk *disk, struct block_device *bdev, 864 sector_t offset); 865 extern void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b); 866 extern void blk_queue_dma_pad(struct request_queue *, unsigned int); 867 extern void blk_queue_update_dma_pad(struct request_queue *, unsigned int); 868 extern int blk_queue_dma_drain(struct request_queue *q, 869 dma_drain_needed_fn *dma_drain_needed, 870 void *buf, unsigned int size); 871 extern void blk_queue_lld_busy(struct request_queue *q, lld_busy_fn *fn); 872 extern void blk_queue_segment_boundary(struct request_queue *, unsigned long); 873 extern void blk_queue_prep_rq(struct request_queue *, prep_rq_fn *pfn); 874 extern void blk_queue_unprep_rq(struct request_queue *, unprep_rq_fn *ufn); 875 extern void blk_queue_merge_bvec(struct request_queue *, merge_bvec_fn *); 876 extern void blk_queue_dma_alignment(struct request_queue *, int); 877 extern void blk_queue_update_dma_alignment(struct request_queue *, int); 878 extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *); 879 extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *); 880 extern void blk_queue_rq_timeout(struct request_queue *, unsigned int); 881 extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev); 882 extern int blk_queue_ordered(struct request_queue *, unsigned); 883 extern bool blk_do_ordered(struct request_queue *, struct request **); 884 extern unsigned blk_ordered_cur_seq(struct request_queue *); 885 extern unsigned blk_ordered_req_seq(struct request *); 886 extern bool blk_ordered_complete_seq(struct request_queue *, unsigned, int); 887 888 extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *); 889 extern void blk_dump_rq_flags(struct request *, char *); 890 extern void generic_unplug_device(struct request_queue *); 891 extern long nr_blockdev_pages(void); 892 893 int blk_get_queue(struct request_queue *); 894 struct request_queue *blk_alloc_queue(gfp_t); 895 struct request_queue *blk_alloc_queue_node(gfp_t, int); 896 extern void blk_put_queue(struct request_queue *); 897 898 /* 899 * tag stuff 900 */ 901 #define blk_rq_tagged(rq) ((rq)->cmd_flags & REQ_QUEUED) 902 extern int blk_queue_start_tag(struct request_queue *, struct request *); 903 extern struct request *blk_queue_find_tag(struct request_queue *, int); 904 extern void blk_queue_end_tag(struct request_queue *, struct request *); 905 extern int blk_queue_init_tags(struct request_queue *, int, struct blk_queue_tag *); 906 extern void blk_queue_free_tags(struct request_queue *); 907 extern int blk_queue_resize_tags(struct request_queue *, int); 908 extern void blk_queue_invalidate_tags(struct request_queue *); 909 extern struct blk_queue_tag *blk_init_tags(int); 910 extern void blk_free_tags(struct blk_queue_tag *); 911 912 static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt, 913 int tag) 914 { 915 if (unlikely(bqt == NULL || tag >= bqt->real_max_depth)) 916 return NULL; 917 return bqt->tag_index[tag]; 918 } 919 enum{ 920 BLKDEV_WAIT, /* wait for completion */ 921 BLKDEV_BARRIER, /*issue request with barrier */ 922 }; 923 #define BLKDEV_IFL_WAIT (1 << BLKDEV_WAIT) 924 #define BLKDEV_IFL_BARRIER (1 << BLKDEV_BARRIER) 925 extern int blkdev_issue_flush(struct block_device *, gfp_t, sector_t *, 926 unsigned long); 927 extern int blkdev_issue_discard(struct block_device *bdev, sector_t sector, 928 sector_t nr_sects, gfp_t gfp_mask, unsigned long flags); 929 extern int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector, 930 sector_t nr_sects, gfp_t gfp_mask, unsigned long flags); 931 static inline int sb_issue_discard(struct super_block *sb, 932 sector_t block, sector_t nr_blocks) 933 { 934 block <<= (sb->s_blocksize_bits - 9); 935 nr_blocks <<= (sb->s_blocksize_bits - 9); 936 return blkdev_issue_discard(sb->s_bdev, block, nr_blocks, GFP_NOFS, 937 BLKDEV_IFL_WAIT | BLKDEV_IFL_BARRIER); 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 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, void *addr, 1092 unsigned int len) 1093 { 1094 unsigned int alignment = queue_dma_alignment(q) | q->dma_pad_mask; 1095 return !((unsigned long)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 #define MODULE_ALIAS_BLOCKDEV(major,minor) \ 1169 MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor)) 1170 #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \ 1171 MODULE_ALIAS("block-major-" __stringify(major) "-*") 1172 1173 #if defined(CONFIG_BLK_DEV_INTEGRITY) 1174 1175 #define INTEGRITY_FLAG_READ 2 /* verify data integrity on read */ 1176 #define INTEGRITY_FLAG_WRITE 4 /* generate data integrity on write */ 1177 1178 struct blk_integrity_exchg { 1179 void *prot_buf; 1180 void *data_buf; 1181 sector_t sector; 1182 unsigned int data_size; 1183 unsigned short sector_size; 1184 const char *disk_name; 1185 }; 1186 1187 typedef void (integrity_gen_fn) (struct blk_integrity_exchg *); 1188 typedef int (integrity_vrfy_fn) (struct blk_integrity_exchg *); 1189 typedef void (integrity_set_tag_fn) (void *, void *, unsigned int); 1190 typedef void (integrity_get_tag_fn) (void *, void *, unsigned int); 1191 1192 struct blk_integrity { 1193 integrity_gen_fn *generate_fn; 1194 integrity_vrfy_fn *verify_fn; 1195 integrity_set_tag_fn *set_tag_fn; 1196 integrity_get_tag_fn *get_tag_fn; 1197 1198 unsigned short flags; 1199 unsigned short tuple_size; 1200 unsigned short sector_size; 1201 unsigned short tag_size; 1202 1203 const char *name; 1204 1205 struct kobject kobj; 1206 }; 1207 1208 extern int blk_integrity_register(struct gendisk *, struct blk_integrity *); 1209 extern void blk_integrity_unregister(struct gendisk *); 1210 extern int blk_integrity_compare(struct gendisk *, struct gendisk *); 1211 extern int blk_rq_map_integrity_sg(struct request *, struct scatterlist *); 1212 extern int blk_rq_count_integrity_sg(struct request *); 1213 1214 static inline 1215 struct blk_integrity *bdev_get_integrity(struct block_device *bdev) 1216 { 1217 return bdev->bd_disk->integrity; 1218 } 1219 1220 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk) 1221 { 1222 return disk->integrity; 1223 } 1224 1225 static inline int blk_integrity_rq(struct request *rq) 1226 { 1227 if (rq->bio == NULL) 1228 return 0; 1229 1230 return bio_integrity(rq->bio); 1231 } 1232 1233 #else /* CONFIG_BLK_DEV_INTEGRITY */ 1234 1235 #define blk_integrity_rq(rq) (0) 1236 #define blk_rq_count_integrity_sg(a) (0) 1237 #define blk_rq_map_integrity_sg(a, b) (0) 1238 #define bdev_get_integrity(a) (0) 1239 #define blk_get_integrity(a) (0) 1240 #define blk_integrity_compare(a, b) (0) 1241 #define blk_integrity_register(a, b) (0) 1242 #define blk_integrity_unregister(a) do { } while (0); 1243 1244 #endif /* CONFIG_BLK_DEV_INTEGRITY */ 1245 1246 struct block_device_operations { 1247 int (*open) (struct block_device *, fmode_t); 1248 int (*release) (struct gendisk *, fmode_t); 1249 int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long); 1250 int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long); 1251 int (*direct_access) (struct block_device *, sector_t, 1252 void **, unsigned long *); 1253 int (*media_changed) (struct gendisk *); 1254 void (*unlock_native_capacity) (struct gendisk *); 1255 int (*revalidate_disk) (struct gendisk *); 1256 int (*getgeo)(struct block_device *, struct hd_geometry *); 1257 /* this callback is with swap_lock and sometimes page table lock held */ 1258 void (*swap_slot_free_notify) (struct block_device *, unsigned long); 1259 struct module *owner; 1260 }; 1261 1262 extern int __blkdev_driver_ioctl(struct block_device *, fmode_t, unsigned int, 1263 unsigned long); 1264 #else /* CONFIG_BLOCK */ 1265 /* 1266 * stubs for when the block layer is configured out 1267 */ 1268 #define buffer_heads_over_limit 0 1269 1270 static inline long nr_blockdev_pages(void) 1271 { 1272 return 0; 1273 } 1274 1275 #endif /* CONFIG_BLOCK */ 1276 1277 #endif 1278