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_REENTER 6 /* Re-entrancy avoidance */ 392 #define QUEUE_FLAG_ELVSWITCH 7 /* don't use elevator, just do FIFO */ 393 #define QUEUE_FLAG_BIDI 8 /* queue supports bidi requests */ 394 #define QUEUE_FLAG_NOMERGES 9 /* disable merge attempts */ 395 #define QUEUE_FLAG_SAME_COMP 10 /* force complete on same CPU */ 396 #define QUEUE_FLAG_FAIL_IO 11 /* fake timeout */ 397 #define QUEUE_FLAG_STACKABLE 12 /* supports request stacking */ 398 #define QUEUE_FLAG_NONROT 13 /* non-rotational device (SSD) */ 399 #define QUEUE_FLAG_VIRT QUEUE_FLAG_NONROT /* paravirt device */ 400 #define QUEUE_FLAG_IO_STAT 15 /* do IO stats */ 401 #define QUEUE_FLAG_DISCARD 16 /* supports DISCARD */ 402 #define QUEUE_FLAG_NOXMERGES 17 /* No extended merges */ 403 #define QUEUE_FLAG_ADD_RANDOM 18 /* Contributes to random pool */ 404 #define QUEUE_FLAG_SECDISCARD 19 /* supports SECDISCARD */ 405 406 #define QUEUE_FLAG_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \ 407 (1 << QUEUE_FLAG_STACKABLE) | \ 408 (1 << QUEUE_FLAG_SAME_COMP) | \ 409 (1 << QUEUE_FLAG_ADD_RANDOM)) 410 411 static inline int queue_is_locked(struct request_queue *q) 412 { 413 #ifdef CONFIG_SMP 414 spinlock_t *lock = q->queue_lock; 415 return lock && spin_is_locked(lock); 416 #else 417 return 1; 418 #endif 419 } 420 421 static inline void queue_flag_set_unlocked(unsigned int flag, 422 struct request_queue *q) 423 { 424 __set_bit(flag, &q->queue_flags); 425 } 426 427 static inline int queue_flag_test_and_clear(unsigned int flag, 428 struct request_queue *q) 429 { 430 WARN_ON_ONCE(!queue_is_locked(q)); 431 432 if (test_bit(flag, &q->queue_flags)) { 433 __clear_bit(flag, &q->queue_flags); 434 return 1; 435 } 436 437 return 0; 438 } 439 440 static inline int queue_flag_test_and_set(unsigned int flag, 441 struct request_queue *q) 442 { 443 WARN_ON_ONCE(!queue_is_locked(q)); 444 445 if (!test_bit(flag, &q->queue_flags)) { 446 __set_bit(flag, &q->queue_flags); 447 return 0; 448 } 449 450 return 1; 451 } 452 453 static inline void queue_flag_set(unsigned int flag, struct request_queue *q) 454 { 455 WARN_ON_ONCE(!queue_is_locked(q)); 456 __set_bit(flag, &q->queue_flags); 457 } 458 459 static inline void queue_flag_clear_unlocked(unsigned int flag, 460 struct request_queue *q) 461 { 462 __clear_bit(flag, &q->queue_flags); 463 } 464 465 static inline int queue_in_flight(struct request_queue *q) 466 { 467 return q->in_flight[0] + q->in_flight[1]; 468 } 469 470 static inline void queue_flag_clear(unsigned int flag, struct request_queue *q) 471 { 472 WARN_ON_ONCE(!queue_is_locked(q)); 473 __clear_bit(flag, &q->queue_flags); 474 } 475 476 #define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags) 477 #define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags) 478 #define blk_queue_nomerges(q) test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags) 479 #define blk_queue_noxmerges(q) \ 480 test_bit(QUEUE_FLAG_NOXMERGES, &(q)->queue_flags) 481 #define blk_queue_nonrot(q) test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags) 482 #define blk_queue_io_stat(q) test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags) 483 #define blk_queue_add_random(q) test_bit(QUEUE_FLAG_ADD_RANDOM, &(q)->queue_flags) 484 #define blk_queue_stackable(q) \ 485 test_bit(QUEUE_FLAG_STACKABLE, &(q)->queue_flags) 486 #define blk_queue_discard(q) test_bit(QUEUE_FLAG_DISCARD, &(q)->queue_flags) 487 #define blk_queue_secdiscard(q) (blk_queue_discard(q) && \ 488 test_bit(QUEUE_FLAG_SECDISCARD, &(q)->queue_flags)) 489 490 #define blk_noretry_request(rq) \ 491 ((rq)->cmd_flags & (REQ_FAILFAST_DEV|REQ_FAILFAST_TRANSPORT| \ 492 REQ_FAILFAST_DRIVER)) 493 494 #define blk_account_rq(rq) \ 495 (((rq)->cmd_flags & REQ_STARTED) && \ 496 ((rq)->cmd_type == REQ_TYPE_FS || \ 497 ((rq)->cmd_flags & REQ_DISCARD))) 498 499 #define blk_pm_request(rq) \ 500 ((rq)->cmd_type == REQ_TYPE_PM_SUSPEND || \ 501 (rq)->cmd_type == REQ_TYPE_PM_RESUME) 502 503 #define blk_rq_cpu_valid(rq) ((rq)->cpu != -1) 504 #define blk_bidi_rq(rq) ((rq)->next_rq != NULL) 505 /* rq->queuelist of dequeued request must be list_empty() */ 506 #define blk_queued_rq(rq) (!list_empty(&(rq)->queuelist)) 507 508 #define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist) 509 510 #define rq_data_dir(rq) ((rq)->cmd_flags & 1) 511 512 static inline unsigned int blk_queue_cluster(struct request_queue *q) 513 { 514 return q->limits.cluster; 515 } 516 517 /* 518 * We regard a request as sync, if either a read or a sync write 519 */ 520 static inline bool rw_is_sync(unsigned int rw_flags) 521 { 522 return !(rw_flags & REQ_WRITE) || (rw_flags & REQ_SYNC); 523 } 524 525 static inline bool rq_is_sync(struct request *rq) 526 { 527 return rw_is_sync(rq->cmd_flags); 528 } 529 530 static inline int blk_queue_full(struct request_queue *q, int sync) 531 { 532 if (sync) 533 return test_bit(QUEUE_FLAG_SYNCFULL, &q->queue_flags); 534 return test_bit(QUEUE_FLAG_ASYNCFULL, &q->queue_flags); 535 } 536 537 static inline void blk_set_queue_full(struct request_queue *q, int sync) 538 { 539 if (sync) 540 queue_flag_set(QUEUE_FLAG_SYNCFULL, q); 541 else 542 queue_flag_set(QUEUE_FLAG_ASYNCFULL, q); 543 } 544 545 static inline void blk_clear_queue_full(struct request_queue *q, int sync) 546 { 547 if (sync) 548 queue_flag_clear(QUEUE_FLAG_SYNCFULL, q); 549 else 550 queue_flag_clear(QUEUE_FLAG_ASYNCFULL, q); 551 } 552 553 554 /* 555 * mergeable request must not have _NOMERGE or _BARRIER bit set, nor may 556 * it already be started by driver. 557 */ 558 #define RQ_NOMERGE_FLAGS \ 559 (REQ_NOMERGE | REQ_STARTED | REQ_SOFTBARRIER | REQ_FLUSH | REQ_FUA) 560 #define rq_mergeable(rq) \ 561 (!((rq)->cmd_flags & RQ_NOMERGE_FLAGS) && \ 562 (((rq)->cmd_flags & REQ_DISCARD) || \ 563 (rq)->cmd_type == REQ_TYPE_FS)) 564 565 /* 566 * q->prep_rq_fn return values 567 */ 568 #define BLKPREP_OK 0 /* serve it */ 569 #define BLKPREP_KILL 1 /* fatal error, kill */ 570 #define BLKPREP_DEFER 2 /* leave on queue */ 571 572 extern unsigned long blk_max_low_pfn, blk_max_pfn; 573 574 /* 575 * standard bounce addresses: 576 * 577 * BLK_BOUNCE_HIGH : bounce all highmem pages 578 * BLK_BOUNCE_ANY : don't bounce anything 579 * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary 580 */ 581 582 #if BITS_PER_LONG == 32 583 #define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT) 584 #else 585 #define BLK_BOUNCE_HIGH -1ULL 586 #endif 587 #define BLK_BOUNCE_ANY (-1ULL) 588 #define BLK_BOUNCE_ISA (DMA_BIT_MASK(24)) 589 590 /* 591 * default timeout for SG_IO if none specified 592 */ 593 #define BLK_DEFAULT_SG_TIMEOUT (60 * HZ) 594 #define BLK_MIN_SG_TIMEOUT (7 * HZ) 595 596 #ifdef CONFIG_BOUNCE 597 extern int init_emergency_isa_pool(void); 598 extern void blk_queue_bounce(struct request_queue *q, struct bio **bio); 599 #else 600 static inline int init_emergency_isa_pool(void) 601 { 602 return 0; 603 } 604 static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio) 605 { 606 } 607 #endif /* CONFIG_MMU */ 608 609 struct rq_map_data { 610 struct page **pages; 611 int page_order; 612 int nr_entries; 613 unsigned long offset; 614 int null_mapped; 615 int from_user; 616 }; 617 618 struct req_iterator { 619 int i; 620 struct bio *bio; 621 }; 622 623 /* This should not be used directly - use rq_for_each_segment */ 624 #define for_each_bio(_bio) \ 625 for (; _bio; _bio = _bio->bi_next) 626 #define __rq_for_each_bio(_bio, rq) \ 627 if ((rq->bio)) \ 628 for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next) 629 630 #define rq_for_each_segment(bvl, _rq, _iter) \ 631 __rq_for_each_bio(_iter.bio, _rq) \ 632 bio_for_each_segment(bvl, _iter.bio, _iter.i) 633 634 #define rq_iter_last(rq, _iter) \ 635 (_iter.bio->bi_next == NULL && _iter.i == _iter.bio->bi_vcnt-1) 636 637 #ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 638 # error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform" 639 #endif 640 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 641 extern void rq_flush_dcache_pages(struct request *rq); 642 #else 643 static inline void rq_flush_dcache_pages(struct request *rq) 644 { 645 } 646 #endif 647 648 extern int blk_register_queue(struct gendisk *disk); 649 extern void blk_unregister_queue(struct gendisk *disk); 650 extern void generic_make_request(struct bio *bio); 651 extern void blk_rq_init(struct request_queue *q, struct request *rq); 652 extern void blk_put_request(struct request *); 653 extern void __blk_put_request(struct request_queue *, struct request *); 654 extern struct request *blk_get_request(struct request_queue *, int, gfp_t); 655 extern struct request *blk_make_request(struct request_queue *, struct bio *, 656 gfp_t); 657 extern void blk_insert_request(struct request_queue *, struct request *, int, void *); 658 extern void blk_requeue_request(struct request_queue *, struct request *); 659 extern void blk_add_request_payload(struct request *rq, struct page *page, 660 unsigned int len); 661 extern int blk_rq_check_limits(struct request_queue *q, struct request *rq); 662 extern int blk_lld_busy(struct request_queue *q); 663 extern int blk_rq_prep_clone(struct request *rq, struct request *rq_src, 664 struct bio_set *bs, gfp_t gfp_mask, 665 int (*bio_ctr)(struct bio *, struct bio *, void *), 666 void *data); 667 extern void blk_rq_unprep_clone(struct request *rq); 668 extern int blk_insert_cloned_request(struct request_queue *q, 669 struct request *rq); 670 extern void blk_delay_queue(struct request_queue *, unsigned long); 671 extern void blk_recount_segments(struct request_queue *, struct bio *); 672 extern int scsi_cmd_ioctl(struct request_queue *, struct gendisk *, fmode_t, 673 unsigned int, void __user *); 674 extern int sg_scsi_ioctl(struct request_queue *, struct gendisk *, fmode_t, 675 struct scsi_ioctl_command __user *); 676 677 /* 678 * A queue has just exitted congestion. Note this in the global counter of 679 * congested queues, and wake up anyone who was waiting for requests to be 680 * put back. 681 */ 682 static inline void blk_clear_queue_congested(struct request_queue *q, int sync) 683 { 684 clear_bdi_congested(&q->backing_dev_info, sync); 685 } 686 687 /* 688 * A queue has just entered congestion. Flag that in the queue's VM-visible 689 * state flags and increment the global gounter of congested queues. 690 */ 691 static inline void blk_set_queue_congested(struct request_queue *q, int sync) 692 { 693 set_bdi_congested(&q->backing_dev_info, sync); 694 } 695 696 extern void blk_start_queue(struct request_queue *q); 697 extern void blk_stop_queue(struct request_queue *q); 698 extern void blk_sync_queue(struct request_queue *q); 699 extern void __blk_stop_queue(struct request_queue *q); 700 extern void __blk_run_queue(struct request_queue *q, bool force_kblockd); 701 extern void blk_run_queue(struct request_queue *); 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 unsigned int should_sort; 861 }; 862 863 extern void blk_start_plug(struct blk_plug *); 864 extern void blk_finish_plug(struct blk_plug *); 865 extern void __blk_flush_plug(struct task_struct *, struct blk_plug *); 866 867 static inline void blk_flush_plug(struct task_struct *tsk) 868 { 869 struct blk_plug *plug = tsk->plug; 870 871 if (unlikely(plug)) 872 __blk_flush_plug(tsk, plug); 873 } 874 875 static inline bool blk_needs_flush_plug(struct task_struct *tsk) 876 { 877 struct blk_plug *plug = tsk->plug; 878 879 return plug && !list_empty(&plug->list); 880 } 881 882 /* 883 * tag stuff 884 */ 885 #define blk_rq_tagged(rq) ((rq)->cmd_flags & REQ_QUEUED) 886 extern int blk_queue_start_tag(struct request_queue *, struct request *); 887 extern struct request *blk_queue_find_tag(struct request_queue *, int); 888 extern void blk_queue_end_tag(struct request_queue *, struct request *); 889 extern int blk_queue_init_tags(struct request_queue *, int, struct blk_queue_tag *); 890 extern void blk_queue_free_tags(struct request_queue *); 891 extern int blk_queue_resize_tags(struct request_queue *, int); 892 extern void blk_queue_invalidate_tags(struct request_queue *); 893 extern struct blk_queue_tag *blk_init_tags(int); 894 extern void blk_free_tags(struct blk_queue_tag *); 895 896 static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt, 897 int tag) 898 { 899 if (unlikely(bqt == NULL || tag >= bqt->real_max_depth)) 900 return NULL; 901 return bqt->tag_index[tag]; 902 } 903 904 #define BLKDEV_DISCARD_SECURE 0x01 /* secure discard */ 905 906 extern int blkdev_issue_flush(struct block_device *, gfp_t, sector_t *); 907 extern int blkdev_issue_discard(struct block_device *bdev, sector_t sector, 908 sector_t nr_sects, gfp_t gfp_mask, unsigned long flags); 909 extern int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector, 910 sector_t nr_sects, gfp_t gfp_mask); 911 static inline int sb_issue_discard(struct super_block *sb, sector_t block, 912 sector_t nr_blocks, gfp_t gfp_mask, unsigned long flags) 913 { 914 return blkdev_issue_discard(sb->s_bdev, block << (sb->s_blocksize_bits - 9), 915 nr_blocks << (sb->s_blocksize_bits - 9), 916 gfp_mask, flags); 917 } 918 static inline int sb_issue_zeroout(struct super_block *sb, sector_t block, 919 sector_t nr_blocks, gfp_t gfp_mask) 920 { 921 return blkdev_issue_zeroout(sb->s_bdev, 922 block << (sb->s_blocksize_bits - 9), 923 nr_blocks << (sb->s_blocksize_bits - 9), 924 gfp_mask); 925 } 926 927 extern int blk_verify_command(unsigned char *cmd, fmode_t has_write_perm); 928 929 enum blk_default_limits { 930 BLK_MAX_SEGMENTS = 128, 931 BLK_SAFE_MAX_SECTORS = 255, 932 BLK_DEF_MAX_SECTORS = 1024, 933 BLK_MAX_SEGMENT_SIZE = 65536, 934 BLK_SEG_BOUNDARY_MASK = 0xFFFFFFFFUL, 935 }; 936 937 #define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist) 938 939 static inline unsigned long queue_bounce_pfn(struct request_queue *q) 940 { 941 return q->limits.bounce_pfn; 942 } 943 944 static inline unsigned long queue_segment_boundary(struct request_queue *q) 945 { 946 return q->limits.seg_boundary_mask; 947 } 948 949 static inline unsigned int queue_max_sectors(struct request_queue *q) 950 { 951 return q->limits.max_sectors; 952 } 953 954 static inline unsigned int queue_max_hw_sectors(struct request_queue *q) 955 { 956 return q->limits.max_hw_sectors; 957 } 958 959 static inline unsigned short queue_max_segments(struct request_queue *q) 960 { 961 return q->limits.max_segments; 962 } 963 964 static inline unsigned int queue_max_segment_size(struct request_queue *q) 965 { 966 return q->limits.max_segment_size; 967 } 968 969 static inline unsigned short queue_logical_block_size(struct request_queue *q) 970 { 971 int retval = 512; 972 973 if (q && q->limits.logical_block_size) 974 retval = q->limits.logical_block_size; 975 976 return retval; 977 } 978 979 static inline unsigned short bdev_logical_block_size(struct block_device *bdev) 980 { 981 return queue_logical_block_size(bdev_get_queue(bdev)); 982 } 983 984 static inline unsigned int queue_physical_block_size(struct request_queue *q) 985 { 986 return q->limits.physical_block_size; 987 } 988 989 static inline unsigned int bdev_physical_block_size(struct block_device *bdev) 990 { 991 return queue_physical_block_size(bdev_get_queue(bdev)); 992 } 993 994 static inline unsigned int queue_io_min(struct request_queue *q) 995 { 996 return q->limits.io_min; 997 } 998 999 static inline int bdev_io_min(struct block_device *bdev) 1000 { 1001 return queue_io_min(bdev_get_queue(bdev)); 1002 } 1003 1004 static inline unsigned int queue_io_opt(struct request_queue *q) 1005 { 1006 return q->limits.io_opt; 1007 } 1008 1009 static inline int bdev_io_opt(struct block_device *bdev) 1010 { 1011 return queue_io_opt(bdev_get_queue(bdev)); 1012 } 1013 1014 static inline int queue_alignment_offset(struct request_queue *q) 1015 { 1016 if (q->limits.misaligned) 1017 return -1; 1018 1019 return q->limits.alignment_offset; 1020 } 1021 1022 static inline int queue_limit_alignment_offset(struct queue_limits *lim, sector_t sector) 1023 { 1024 unsigned int granularity = max(lim->physical_block_size, lim->io_min); 1025 unsigned int alignment = (sector << 9) & (granularity - 1); 1026 1027 return (granularity + lim->alignment_offset - alignment) 1028 & (granularity - 1); 1029 } 1030 1031 static inline int bdev_alignment_offset(struct block_device *bdev) 1032 { 1033 struct request_queue *q = bdev_get_queue(bdev); 1034 1035 if (q->limits.misaligned) 1036 return -1; 1037 1038 if (bdev != bdev->bd_contains) 1039 return bdev->bd_part->alignment_offset; 1040 1041 return q->limits.alignment_offset; 1042 } 1043 1044 static inline int queue_discard_alignment(struct request_queue *q) 1045 { 1046 if (q->limits.discard_misaligned) 1047 return -1; 1048 1049 return q->limits.discard_alignment; 1050 } 1051 1052 static inline int queue_limit_discard_alignment(struct queue_limits *lim, sector_t sector) 1053 { 1054 unsigned int alignment = (sector << 9) & (lim->discard_granularity - 1); 1055 1056 return (lim->discard_granularity + lim->discard_alignment - alignment) 1057 & (lim->discard_granularity - 1); 1058 } 1059 1060 static inline unsigned int queue_discard_zeroes_data(struct request_queue *q) 1061 { 1062 if (q->limits.discard_zeroes_data == 1) 1063 return 1; 1064 1065 return 0; 1066 } 1067 1068 static inline unsigned int bdev_discard_zeroes_data(struct block_device *bdev) 1069 { 1070 return queue_discard_zeroes_data(bdev_get_queue(bdev)); 1071 } 1072 1073 static inline int queue_dma_alignment(struct request_queue *q) 1074 { 1075 return q ? q->dma_alignment : 511; 1076 } 1077 1078 static inline int blk_rq_aligned(struct request_queue *q, unsigned long addr, 1079 unsigned int len) 1080 { 1081 unsigned int alignment = queue_dma_alignment(q) | q->dma_pad_mask; 1082 return !(addr & alignment) && !(len & alignment); 1083 } 1084 1085 /* assumes size > 256 */ 1086 static inline unsigned int blksize_bits(unsigned int size) 1087 { 1088 unsigned int bits = 8; 1089 do { 1090 bits++; 1091 size >>= 1; 1092 } while (size > 256); 1093 return bits; 1094 } 1095 1096 static inline unsigned int block_size(struct block_device *bdev) 1097 { 1098 return bdev->bd_block_size; 1099 } 1100 1101 typedef struct {struct page *v;} Sector; 1102 1103 unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *); 1104 1105 static inline void put_dev_sector(Sector p) 1106 { 1107 page_cache_release(p.v); 1108 } 1109 1110 struct work_struct; 1111 int kblockd_schedule_work(struct request_queue *q, struct work_struct *work); 1112 1113 #ifdef CONFIG_BLK_CGROUP 1114 /* 1115 * This should not be using sched_clock(). A real patch is in progress 1116 * to fix this up, until that is in place we need to disable preemption 1117 * around sched_clock() in this function and set_io_start_time_ns(). 1118 */ 1119 static inline void set_start_time_ns(struct request *req) 1120 { 1121 preempt_disable(); 1122 req->start_time_ns = sched_clock(); 1123 preempt_enable(); 1124 } 1125 1126 static inline void set_io_start_time_ns(struct request *req) 1127 { 1128 preempt_disable(); 1129 req->io_start_time_ns = sched_clock(); 1130 preempt_enable(); 1131 } 1132 1133 static inline uint64_t rq_start_time_ns(struct request *req) 1134 { 1135 return req->start_time_ns; 1136 } 1137 1138 static inline uint64_t rq_io_start_time_ns(struct request *req) 1139 { 1140 return req->io_start_time_ns; 1141 } 1142 #else 1143 static inline void set_start_time_ns(struct request *req) {} 1144 static inline void set_io_start_time_ns(struct request *req) {} 1145 static inline uint64_t rq_start_time_ns(struct request *req) 1146 { 1147 return 0; 1148 } 1149 static inline uint64_t rq_io_start_time_ns(struct request *req) 1150 { 1151 return 0; 1152 } 1153 #endif 1154 1155 #ifdef CONFIG_BLK_DEV_THROTTLING 1156 extern int blk_throtl_init(struct request_queue *q); 1157 extern void blk_throtl_exit(struct request_queue *q); 1158 extern int blk_throtl_bio(struct request_queue *q, struct bio **bio); 1159 #else /* CONFIG_BLK_DEV_THROTTLING */ 1160 static inline int blk_throtl_bio(struct request_queue *q, struct bio **bio) 1161 { 1162 return 0; 1163 } 1164 1165 static inline int blk_throtl_init(struct request_queue *q) { return 0; } 1166 static inline int blk_throtl_exit(struct request_queue *q) { return 0; } 1167 #endif /* CONFIG_BLK_DEV_THROTTLING */ 1168 1169 #define MODULE_ALIAS_BLOCKDEV(major,minor) \ 1170 MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor)) 1171 #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \ 1172 MODULE_ALIAS("block-major-" __stringify(major) "-*") 1173 1174 #if defined(CONFIG_BLK_DEV_INTEGRITY) 1175 1176 #define INTEGRITY_FLAG_READ 2 /* verify data integrity on read */ 1177 #define INTEGRITY_FLAG_WRITE 4 /* generate data integrity on write */ 1178 1179 struct blk_integrity_exchg { 1180 void *prot_buf; 1181 void *data_buf; 1182 sector_t sector; 1183 unsigned int data_size; 1184 unsigned short sector_size; 1185 const char *disk_name; 1186 }; 1187 1188 typedef void (integrity_gen_fn) (struct blk_integrity_exchg *); 1189 typedef int (integrity_vrfy_fn) (struct blk_integrity_exchg *); 1190 typedef void (integrity_set_tag_fn) (void *, void *, unsigned int); 1191 typedef void (integrity_get_tag_fn) (void *, void *, unsigned int); 1192 1193 struct blk_integrity { 1194 integrity_gen_fn *generate_fn; 1195 integrity_vrfy_fn *verify_fn; 1196 integrity_set_tag_fn *set_tag_fn; 1197 integrity_get_tag_fn *get_tag_fn; 1198 1199 unsigned short flags; 1200 unsigned short tuple_size; 1201 unsigned short sector_size; 1202 unsigned short tag_size; 1203 1204 const char *name; 1205 1206 struct kobject kobj; 1207 }; 1208 1209 extern int blk_integrity_register(struct gendisk *, struct blk_integrity *); 1210 extern void blk_integrity_unregister(struct gendisk *); 1211 extern int blk_integrity_compare(struct gendisk *, struct gendisk *); 1212 extern int blk_rq_map_integrity_sg(struct request_queue *, struct bio *, 1213 struct scatterlist *); 1214 extern int blk_rq_count_integrity_sg(struct request_queue *, struct bio *); 1215 extern int blk_integrity_merge_rq(struct request_queue *, struct request *, 1216 struct request *); 1217 extern int blk_integrity_merge_bio(struct request_queue *, struct request *, 1218 struct bio *); 1219 1220 static inline 1221 struct blk_integrity *bdev_get_integrity(struct block_device *bdev) 1222 { 1223 return bdev->bd_disk->integrity; 1224 } 1225 1226 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk) 1227 { 1228 return disk->integrity; 1229 } 1230 1231 static inline int blk_integrity_rq(struct request *rq) 1232 { 1233 if (rq->bio == NULL) 1234 return 0; 1235 1236 return bio_integrity(rq->bio); 1237 } 1238 1239 static inline void blk_queue_max_integrity_segments(struct request_queue *q, 1240 unsigned int segs) 1241 { 1242 q->limits.max_integrity_segments = segs; 1243 } 1244 1245 static inline unsigned short 1246 queue_max_integrity_segments(struct request_queue *q) 1247 { 1248 return q->limits.max_integrity_segments; 1249 } 1250 1251 #else /* CONFIG_BLK_DEV_INTEGRITY */ 1252 1253 #define blk_integrity_rq(rq) (0) 1254 #define blk_rq_count_integrity_sg(a, b) (0) 1255 #define blk_rq_map_integrity_sg(a, b, c) (0) 1256 #define bdev_get_integrity(a) (0) 1257 #define blk_get_integrity(a) (0) 1258 #define blk_integrity_compare(a, b) (0) 1259 #define blk_integrity_register(a, b) (0) 1260 #define blk_integrity_unregister(a) do { } while (0); 1261 #define blk_queue_max_integrity_segments(a, b) do { } while (0); 1262 #define queue_max_integrity_segments(a) (0) 1263 #define blk_integrity_merge_rq(a, b, c) (0) 1264 #define blk_integrity_merge_bio(a, b, c) (0) 1265 1266 #endif /* CONFIG_BLK_DEV_INTEGRITY */ 1267 1268 struct block_device_operations { 1269 int (*open) (struct block_device *, fmode_t); 1270 int (*release) (struct gendisk *, fmode_t); 1271 int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long); 1272 int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long); 1273 int (*direct_access) (struct block_device *, sector_t, 1274 void **, unsigned long *); 1275 unsigned int (*check_events) (struct gendisk *disk, 1276 unsigned int clearing); 1277 /* ->media_changed() is DEPRECATED, use ->check_events() instead */ 1278 int (*media_changed) (struct gendisk *); 1279 void (*unlock_native_capacity) (struct gendisk *); 1280 int (*revalidate_disk) (struct gendisk *); 1281 int (*getgeo)(struct block_device *, struct hd_geometry *); 1282 /* this callback is with swap_lock and sometimes page table lock held */ 1283 void (*swap_slot_free_notify) (struct block_device *, unsigned long); 1284 struct module *owner; 1285 }; 1286 1287 extern int __blkdev_driver_ioctl(struct block_device *, fmode_t, unsigned int, 1288 unsigned long); 1289 #else /* CONFIG_BLOCK */ 1290 /* 1291 * stubs for when the block layer is configured out 1292 */ 1293 #define buffer_heads_over_limit 0 1294 1295 static inline long nr_blockdev_pages(void) 1296 { 1297 return 0; 1298 } 1299 1300 struct blk_plug { 1301 }; 1302 1303 static inline void blk_start_plug(struct blk_plug *plug) 1304 { 1305 } 1306 1307 static inline void blk_finish_plug(struct blk_plug *plug) 1308 { 1309 } 1310 1311 static inline void blk_flush_plug(struct task_struct *task) 1312 { 1313 } 1314 1315 static inline bool blk_needs_flush_plug(struct task_struct *tsk) 1316 { 1317 return false; 1318 } 1319 1320 #endif /* CONFIG_BLOCK */ 1321 1322 #endif 1323