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 #if defined(CONFIG_BLK_DEV_INTEGRITY) 128 unsigned short nr_integrity_segments; 129 #endif 130 131 unsigned short ioprio; 132 133 int ref_count; 134 135 void *special; /* opaque pointer available for LLD use */ 136 char *buffer; /* kaddr of the current segment if available */ 137 138 int tag; 139 int errors; 140 141 /* 142 * when request is used as a packet command carrier 143 */ 144 unsigned char __cmd[BLK_MAX_CDB]; 145 unsigned char *cmd; 146 unsigned short cmd_len; 147 148 unsigned int extra_len; /* length of alignment and padding */ 149 unsigned int sense_len; 150 unsigned int resid_len; /* residual count */ 151 void *sense; 152 153 unsigned long deadline; 154 struct list_head timeout_list; 155 unsigned int timeout; 156 int retries; 157 158 /* 159 * completion callback. 160 */ 161 rq_end_io_fn *end_io; 162 void *end_io_data; 163 164 /* for bidi */ 165 struct request *next_rq; 166 }; 167 168 static inline unsigned short req_get_ioprio(struct request *req) 169 { 170 return req->ioprio; 171 } 172 173 /* 174 * State information carried for REQ_TYPE_PM_SUSPEND and REQ_TYPE_PM_RESUME 175 * requests. Some step values could eventually be made generic. 176 */ 177 struct request_pm_state 178 { 179 /* PM state machine step value, currently driver specific */ 180 int pm_step; 181 /* requested PM state value (S1, S2, S3, S4, ...) */ 182 u32 pm_state; 183 void* data; /* for driver use */ 184 }; 185 186 #include <linux/elevator.h> 187 188 typedef void (request_fn_proc) (struct request_queue *q); 189 typedef int (make_request_fn) (struct request_queue *q, struct bio *bio); 190 typedef int (prep_rq_fn) (struct request_queue *, struct request *); 191 typedef void (unprep_rq_fn) (struct request_queue *, struct request *); 192 typedef void (unplug_fn) (struct request_queue *); 193 194 struct bio_vec; 195 struct bvec_merge_data { 196 struct block_device *bi_bdev; 197 sector_t bi_sector; 198 unsigned bi_size; 199 unsigned long bi_rw; 200 }; 201 typedef int (merge_bvec_fn) (struct request_queue *, struct bvec_merge_data *, 202 struct bio_vec *); 203 typedef void (softirq_done_fn)(struct request *); 204 typedef int (dma_drain_needed_fn)(struct request *); 205 typedef int (lld_busy_fn) (struct request_queue *q); 206 207 enum blk_eh_timer_return { 208 BLK_EH_NOT_HANDLED, 209 BLK_EH_HANDLED, 210 BLK_EH_RESET_TIMER, 211 }; 212 213 typedef enum blk_eh_timer_return (rq_timed_out_fn)(struct request *); 214 215 enum blk_queue_state { 216 Queue_down, 217 Queue_up, 218 }; 219 220 struct blk_queue_tag { 221 struct request **tag_index; /* map of busy tags */ 222 unsigned long *tag_map; /* bit map of free/busy tags */ 223 int busy; /* current depth */ 224 int max_depth; /* what we will send to device */ 225 int real_max_depth; /* what the array can hold */ 226 atomic_t refcnt; /* map can be shared */ 227 }; 228 229 #define BLK_SCSI_MAX_CMDS (256) 230 #define BLK_SCSI_CMD_PER_LONG (BLK_SCSI_MAX_CMDS / (sizeof(long) * 8)) 231 232 struct queue_limits { 233 unsigned long bounce_pfn; 234 unsigned long seg_boundary_mask; 235 236 unsigned int max_hw_sectors; 237 unsigned int max_sectors; 238 unsigned int max_segment_size; 239 unsigned int physical_block_size; 240 unsigned int alignment_offset; 241 unsigned int io_min; 242 unsigned int io_opt; 243 unsigned int max_discard_sectors; 244 unsigned int discard_granularity; 245 unsigned int discard_alignment; 246 247 unsigned short logical_block_size; 248 unsigned short max_segments; 249 unsigned short max_integrity_segments; 250 251 unsigned char misaligned; 252 unsigned char discard_misaligned; 253 unsigned char cluster; 254 signed char discard_zeroes_data; 255 }; 256 257 struct request_queue 258 { 259 /* 260 * Together with queue_head for cacheline sharing 261 */ 262 struct list_head queue_head; 263 struct request *last_merge; 264 struct elevator_queue *elevator; 265 266 /* 267 * the queue request freelist, one for reads and one for writes 268 */ 269 struct request_list rq; 270 271 request_fn_proc *request_fn; 272 make_request_fn *make_request_fn; 273 prep_rq_fn *prep_rq_fn; 274 unprep_rq_fn *unprep_rq_fn; 275 unplug_fn *unplug_fn; 276 merge_bvec_fn *merge_bvec_fn; 277 softirq_done_fn *softirq_done_fn; 278 rq_timed_out_fn *rq_timed_out_fn; 279 dma_drain_needed_fn *dma_drain_needed; 280 lld_busy_fn *lld_busy_fn; 281 282 /* 283 * Dispatch queue sorting 284 */ 285 sector_t end_sector; 286 struct request *boundary_rq; 287 288 /* 289 * Auto-unplugging state 290 */ 291 struct timer_list unplug_timer; 292 int unplug_thresh; /* After this many requests */ 293 unsigned long unplug_delay; /* After this many jiffies */ 294 struct work_struct unplug_work; 295 296 struct backing_dev_info backing_dev_info; 297 298 /* 299 * The queue owner gets to use this for whatever they like. 300 * ll_rw_blk doesn't touch it. 301 */ 302 void *queuedata; 303 304 /* 305 * queue needs bounce pages for pages above this limit 306 */ 307 gfp_t bounce_gfp; 308 309 /* 310 * various queue flags, see QUEUE_* below 311 */ 312 unsigned long queue_flags; 313 314 /* 315 * protects queue structures from reentrancy. ->__queue_lock should 316 * _never_ be used directly, it is queue private. always use 317 * ->queue_lock. 318 */ 319 spinlock_t __queue_lock; 320 spinlock_t *queue_lock; 321 322 /* 323 * queue kobject 324 */ 325 struct kobject kobj; 326 327 /* 328 * queue settings 329 */ 330 unsigned long nr_requests; /* Max # of requests */ 331 unsigned int nr_congestion_on; 332 unsigned int nr_congestion_off; 333 unsigned int nr_batching; 334 335 void *dma_drain_buffer; 336 unsigned int dma_drain_size; 337 unsigned int dma_pad_mask; 338 unsigned int dma_alignment; 339 340 struct blk_queue_tag *queue_tags; 341 struct list_head tag_busy_list; 342 343 unsigned int nr_sorted; 344 unsigned int in_flight[2]; 345 346 unsigned int rq_timeout; 347 struct timer_list timeout; 348 struct list_head timeout_list; 349 350 struct queue_limits limits; 351 352 /* 353 * sg stuff 354 */ 355 unsigned int sg_timeout; 356 unsigned int sg_reserved_size; 357 int node; 358 #ifdef CONFIG_BLK_DEV_IO_TRACE 359 struct blk_trace *blk_trace; 360 #endif 361 /* 362 * for flush operations 363 */ 364 unsigned int flush_flags; 365 unsigned int flush_seq; 366 int flush_err; 367 struct request flush_rq; 368 struct request *orig_flush_rq; 369 struct list_head pending_flushes; 370 371 struct mutex sysfs_lock; 372 373 #if defined(CONFIG_BLK_DEV_BSG) 374 struct bsg_class_device bsg_dev; 375 #endif 376 377 #ifdef CONFIG_BLK_DEV_THROTTLING 378 /* Throttle data */ 379 struct throtl_data *td; 380 #endif 381 }; 382 383 #define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */ 384 #define QUEUE_FLAG_STOPPED 2 /* queue is stopped */ 385 #define QUEUE_FLAG_SYNCFULL 3 /* read queue has been filled */ 386 #define QUEUE_FLAG_ASYNCFULL 4 /* write queue has been filled */ 387 #define QUEUE_FLAG_DEAD 5 /* queue being torn down */ 388 #define QUEUE_FLAG_REENTER 6 /* Re-entrancy avoidance */ 389 #define QUEUE_FLAG_PLUGGED 7 /* queue is plugged */ 390 #define QUEUE_FLAG_ELVSWITCH 8 /* don't use elevator, just do FIFO */ 391 #define QUEUE_FLAG_BIDI 9 /* queue supports bidi requests */ 392 #define QUEUE_FLAG_NOMERGES 10 /* disable merge attempts */ 393 #define QUEUE_FLAG_SAME_COMP 11 /* force complete on same CPU */ 394 #define QUEUE_FLAG_FAIL_IO 12 /* fake timeout */ 395 #define QUEUE_FLAG_STACKABLE 13 /* supports request stacking */ 396 #define QUEUE_FLAG_NONROT 14 /* non-rotational device (SSD) */ 397 #define QUEUE_FLAG_VIRT QUEUE_FLAG_NONROT /* paravirt device */ 398 #define QUEUE_FLAG_IO_STAT 15 /* do IO stats */ 399 #define QUEUE_FLAG_DISCARD 16 /* supports DISCARD */ 400 #define QUEUE_FLAG_NOXMERGES 17 /* No extended merges */ 401 #define QUEUE_FLAG_ADD_RANDOM 18 /* Contributes to random pool */ 402 #define QUEUE_FLAG_SECDISCARD 19 /* supports SECDISCARD */ 403 404 #define QUEUE_FLAG_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \ 405 (1 << QUEUE_FLAG_STACKABLE) | \ 406 (1 << QUEUE_FLAG_SAME_COMP) | \ 407 (1 << QUEUE_FLAG_ADD_RANDOM)) 408 409 static inline int queue_is_locked(struct request_queue *q) 410 { 411 #ifdef CONFIG_SMP 412 spinlock_t *lock = q->queue_lock; 413 return lock && spin_is_locked(lock); 414 #else 415 return 1; 416 #endif 417 } 418 419 static inline void queue_flag_set_unlocked(unsigned int flag, 420 struct request_queue *q) 421 { 422 __set_bit(flag, &q->queue_flags); 423 } 424 425 static inline int queue_flag_test_and_clear(unsigned int flag, 426 struct request_queue *q) 427 { 428 WARN_ON_ONCE(!queue_is_locked(q)); 429 430 if (test_bit(flag, &q->queue_flags)) { 431 __clear_bit(flag, &q->queue_flags); 432 return 1; 433 } 434 435 return 0; 436 } 437 438 static inline int queue_flag_test_and_set(unsigned int flag, 439 struct request_queue *q) 440 { 441 WARN_ON_ONCE(!queue_is_locked(q)); 442 443 if (!test_bit(flag, &q->queue_flags)) { 444 __set_bit(flag, &q->queue_flags); 445 return 0; 446 } 447 448 return 1; 449 } 450 451 static inline void queue_flag_set(unsigned int flag, struct request_queue *q) 452 { 453 WARN_ON_ONCE(!queue_is_locked(q)); 454 __set_bit(flag, &q->queue_flags); 455 } 456 457 static inline void queue_flag_clear_unlocked(unsigned int flag, 458 struct request_queue *q) 459 { 460 __clear_bit(flag, &q->queue_flags); 461 } 462 463 static inline int queue_in_flight(struct request_queue *q) 464 { 465 return q->in_flight[0] + q->in_flight[1]; 466 } 467 468 static inline void queue_flag_clear(unsigned int flag, struct request_queue *q) 469 { 470 WARN_ON_ONCE(!queue_is_locked(q)); 471 __clear_bit(flag, &q->queue_flags); 472 } 473 474 #define blk_queue_plugged(q) test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags) 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 register_disk(struct gendisk *dev); 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_plug_device(struct request_queue *); 671 extern void blk_plug_device_unlocked(struct request_queue *); 672 extern int blk_remove_plug(struct request_queue *); 673 extern void blk_recount_segments(struct request_queue *, struct bio *); 674 extern int scsi_cmd_ioctl(struct request_queue *, struct gendisk *, fmode_t, 675 unsigned int, void __user *); 676 extern int sg_scsi_ioctl(struct request_queue *, struct gendisk *, fmode_t, 677 struct scsi_ioctl_command __user *); 678 679 /* 680 * A queue has just exitted congestion. Note this in the global counter of 681 * congested queues, and wake up anyone who was waiting for requests to be 682 * put back. 683 */ 684 static inline void blk_clear_queue_congested(struct request_queue *q, int sync) 685 { 686 clear_bdi_congested(&q->backing_dev_info, sync); 687 } 688 689 /* 690 * A queue has just entered congestion. Flag that in the queue's VM-visible 691 * state flags and increment the global gounter of congested queues. 692 */ 693 static inline void blk_set_queue_congested(struct request_queue *q, int sync) 694 { 695 set_bdi_congested(&q->backing_dev_info, sync); 696 } 697 698 extern void blk_start_queue(struct request_queue *q); 699 extern void blk_stop_queue(struct request_queue *q); 700 extern void blk_sync_queue(struct request_queue *q); 701 extern void __blk_stop_queue(struct request_queue *q); 702 extern void __blk_run_queue(struct request_queue *); 703 extern void blk_run_queue(struct request_queue *); 704 extern int blk_rq_map_user(struct request_queue *, struct request *, 705 struct rq_map_data *, void __user *, unsigned long, 706 gfp_t); 707 extern int blk_rq_unmap_user(struct bio *); 708 extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, unsigned int, gfp_t); 709 extern int blk_rq_map_user_iov(struct request_queue *, struct request *, 710 struct rq_map_data *, struct sg_iovec *, int, 711 unsigned int, gfp_t); 712 extern int blk_execute_rq(struct request_queue *, struct gendisk *, 713 struct request *, int); 714 extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *, 715 struct request *, int, rq_end_io_fn *); 716 extern void blk_unplug(struct request_queue *q); 717 718 static inline struct request_queue *bdev_get_queue(struct block_device *bdev) 719 { 720 return bdev->bd_disk->queue; 721 } 722 723 /* 724 * blk_rq_pos() : the current sector 725 * blk_rq_bytes() : bytes left in the entire request 726 * blk_rq_cur_bytes() : bytes left in the current segment 727 * blk_rq_err_bytes() : bytes left till the next error boundary 728 * blk_rq_sectors() : sectors left in the entire request 729 * blk_rq_cur_sectors() : sectors left in the current segment 730 */ 731 static inline sector_t blk_rq_pos(const struct request *rq) 732 { 733 return rq->__sector; 734 } 735 736 static inline unsigned int blk_rq_bytes(const struct request *rq) 737 { 738 return rq->__data_len; 739 } 740 741 static inline int blk_rq_cur_bytes(const struct request *rq) 742 { 743 return rq->bio ? bio_cur_bytes(rq->bio) : 0; 744 } 745 746 extern unsigned int blk_rq_err_bytes(const struct request *rq); 747 748 static inline unsigned int blk_rq_sectors(const struct request *rq) 749 { 750 return blk_rq_bytes(rq) >> 9; 751 } 752 753 static inline unsigned int blk_rq_cur_sectors(const struct request *rq) 754 { 755 return blk_rq_cur_bytes(rq) >> 9; 756 } 757 758 /* 759 * Request issue related functions. 760 */ 761 extern struct request *blk_peek_request(struct request_queue *q); 762 extern void blk_start_request(struct request *rq); 763 extern struct request *blk_fetch_request(struct request_queue *q); 764 765 /* 766 * Request completion related functions. 767 * 768 * blk_update_request() completes given number of bytes and updates 769 * the request without completing it. 770 * 771 * blk_end_request() and friends. __blk_end_request() must be called 772 * with the request queue spinlock acquired. 773 * 774 * Several drivers define their own end_request and call 775 * blk_end_request() for parts of the original function. 776 * This prevents code duplication in drivers. 777 */ 778 extern bool blk_update_request(struct request *rq, int error, 779 unsigned int nr_bytes); 780 extern bool blk_end_request(struct request *rq, int error, 781 unsigned int nr_bytes); 782 extern void blk_end_request_all(struct request *rq, int error); 783 extern bool blk_end_request_cur(struct request *rq, int error); 784 extern bool blk_end_request_err(struct request *rq, int error); 785 extern bool __blk_end_request(struct request *rq, int error, 786 unsigned int nr_bytes); 787 extern void __blk_end_request_all(struct request *rq, int error); 788 extern bool __blk_end_request_cur(struct request *rq, int error); 789 extern bool __blk_end_request_err(struct request *rq, int error); 790 791 extern void blk_complete_request(struct request *); 792 extern void __blk_complete_request(struct request *); 793 extern void blk_abort_request(struct request *); 794 extern void blk_abort_queue(struct request_queue *); 795 extern void blk_unprep_request(struct request *); 796 797 /* 798 * Access functions for manipulating queue properties 799 */ 800 extern struct request_queue *blk_init_queue_node(request_fn_proc *rfn, 801 spinlock_t *lock, int node_id); 802 extern struct request_queue *blk_init_allocated_queue_node(struct request_queue *, 803 request_fn_proc *, 804 spinlock_t *, int node_id); 805 extern struct request_queue *blk_init_queue(request_fn_proc *, spinlock_t *); 806 extern struct request_queue *blk_init_allocated_queue(struct request_queue *, 807 request_fn_proc *, spinlock_t *); 808 extern void blk_cleanup_queue(struct request_queue *); 809 extern void blk_queue_make_request(struct request_queue *, make_request_fn *); 810 extern void blk_queue_bounce_limit(struct request_queue *, u64); 811 extern void blk_limits_max_hw_sectors(struct queue_limits *, unsigned int); 812 extern void blk_queue_max_hw_sectors(struct request_queue *, unsigned int); 813 extern void blk_queue_max_segments(struct request_queue *, unsigned short); 814 extern void blk_queue_max_segment_size(struct request_queue *, unsigned int); 815 extern void blk_queue_max_discard_sectors(struct request_queue *q, 816 unsigned int max_discard_sectors); 817 extern void blk_queue_logical_block_size(struct request_queue *, unsigned short); 818 extern void blk_queue_physical_block_size(struct request_queue *, unsigned int); 819 extern void blk_queue_alignment_offset(struct request_queue *q, 820 unsigned int alignment); 821 extern void blk_limits_io_min(struct queue_limits *limits, unsigned int min); 822 extern void blk_queue_io_min(struct request_queue *q, unsigned int min); 823 extern void blk_limits_io_opt(struct queue_limits *limits, unsigned int opt); 824 extern void blk_queue_io_opt(struct request_queue *q, unsigned int opt); 825 extern void blk_set_default_limits(struct queue_limits *lim); 826 extern int blk_stack_limits(struct queue_limits *t, struct queue_limits *b, 827 sector_t offset); 828 extern int bdev_stack_limits(struct queue_limits *t, struct block_device *bdev, 829 sector_t offset); 830 extern void disk_stack_limits(struct gendisk *disk, struct block_device *bdev, 831 sector_t offset); 832 extern void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b); 833 extern void blk_queue_dma_pad(struct request_queue *, unsigned int); 834 extern void blk_queue_update_dma_pad(struct request_queue *, unsigned int); 835 extern int blk_queue_dma_drain(struct request_queue *q, 836 dma_drain_needed_fn *dma_drain_needed, 837 void *buf, unsigned int size); 838 extern void blk_queue_lld_busy(struct request_queue *q, lld_busy_fn *fn); 839 extern void blk_queue_segment_boundary(struct request_queue *, unsigned long); 840 extern void blk_queue_prep_rq(struct request_queue *, prep_rq_fn *pfn); 841 extern void blk_queue_unprep_rq(struct request_queue *, unprep_rq_fn *ufn); 842 extern void blk_queue_merge_bvec(struct request_queue *, merge_bvec_fn *); 843 extern void blk_queue_dma_alignment(struct request_queue *, int); 844 extern void blk_queue_update_dma_alignment(struct request_queue *, int); 845 extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *); 846 extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *); 847 extern void blk_queue_rq_timeout(struct request_queue *, unsigned int); 848 extern void blk_queue_flush(struct request_queue *q, unsigned int flush); 849 extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev); 850 851 extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *); 852 extern void blk_dump_rq_flags(struct request *, char *); 853 extern void generic_unplug_device(struct request_queue *); 854 extern long nr_blockdev_pages(void); 855 856 int blk_get_queue(struct request_queue *); 857 struct request_queue *blk_alloc_queue(gfp_t); 858 struct request_queue *blk_alloc_queue_node(gfp_t, int); 859 extern void blk_put_queue(struct request_queue *); 860 861 /* 862 * tag stuff 863 */ 864 #define blk_rq_tagged(rq) ((rq)->cmd_flags & REQ_QUEUED) 865 extern int blk_queue_start_tag(struct request_queue *, struct request *); 866 extern struct request *blk_queue_find_tag(struct request_queue *, int); 867 extern void blk_queue_end_tag(struct request_queue *, struct request *); 868 extern int blk_queue_init_tags(struct request_queue *, int, struct blk_queue_tag *); 869 extern void blk_queue_free_tags(struct request_queue *); 870 extern int blk_queue_resize_tags(struct request_queue *, int); 871 extern void blk_queue_invalidate_tags(struct request_queue *); 872 extern struct blk_queue_tag *blk_init_tags(int); 873 extern void blk_free_tags(struct blk_queue_tag *); 874 875 static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt, 876 int tag) 877 { 878 if (unlikely(bqt == NULL || tag >= bqt->real_max_depth)) 879 return NULL; 880 return bqt->tag_index[tag]; 881 } 882 883 #define BLKDEV_DISCARD_SECURE 0x01 /* secure discard */ 884 885 extern int blkdev_issue_flush(struct block_device *, gfp_t, sector_t *); 886 extern int blkdev_issue_discard(struct block_device *bdev, sector_t sector, 887 sector_t nr_sects, gfp_t gfp_mask, unsigned long flags); 888 extern int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector, 889 sector_t nr_sects, gfp_t gfp_mask); 890 static inline int sb_issue_discard(struct super_block *sb, sector_t block, 891 sector_t nr_blocks, gfp_t gfp_mask, unsigned long flags) 892 { 893 return blkdev_issue_discard(sb->s_bdev, block << (sb->s_blocksize_bits - 9), 894 nr_blocks << (sb->s_blocksize_bits - 9), 895 gfp_mask, flags); 896 } 897 static inline int sb_issue_zeroout(struct super_block *sb, sector_t block, 898 sector_t nr_blocks, gfp_t gfp_mask) 899 { 900 return blkdev_issue_zeroout(sb->s_bdev, 901 block << (sb->s_blocksize_bits - 9), 902 nr_blocks << (sb->s_blocksize_bits - 9), 903 gfp_mask); 904 } 905 906 extern int blk_verify_command(unsigned char *cmd, fmode_t has_write_perm); 907 908 enum blk_default_limits { 909 BLK_MAX_SEGMENTS = 128, 910 BLK_SAFE_MAX_SECTORS = 255, 911 BLK_DEF_MAX_SECTORS = 1024, 912 BLK_MAX_SEGMENT_SIZE = 65536, 913 BLK_SEG_BOUNDARY_MASK = 0xFFFFFFFFUL, 914 }; 915 916 #define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist) 917 918 static inline unsigned long queue_bounce_pfn(struct request_queue *q) 919 { 920 return q->limits.bounce_pfn; 921 } 922 923 static inline unsigned long queue_segment_boundary(struct request_queue *q) 924 { 925 return q->limits.seg_boundary_mask; 926 } 927 928 static inline unsigned int queue_max_sectors(struct request_queue *q) 929 { 930 return q->limits.max_sectors; 931 } 932 933 static inline unsigned int queue_max_hw_sectors(struct request_queue *q) 934 { 935 return q->limits.max_hw_sectors; 936 } 937 938 static inline unsigned short queue_max_segments(struct request_queue *q) 939 { 940 return q->limits.max_segments; 941 } 942 943 static inline unsigned int queue_max_segment_size(struct request_queue *q) 944 { 945 return q->limits.max_segment_size; 946 } 947 948 static inline unsigned short queue_logical_block_size(struct request_queue *q) 949 { 950 int retval = 512; 951 952 if (q && q->limits.logical_block_size) 953 retval = q->limits.logical_block_size; 954 955 return retval; 956 } 957 958 static inline unsigned short bdev_logical_block_size(struct block_device *bdev) 959 { 960 return queue_logical_block_size(bdev_get_queue(bdev)); 961 } 962 963 static inline unsigned int queue_physical_block_size(struct request_queue *q) 964 { 965 return q->limits.physical_block_size; 966 } 967 968 static inline unsigned int bdev_physical_block_size(struct block_device *bdev) 969 { 970 return queue_physical_block_size(bdev_get_queue(bdev)); 971 } 972 973 static inline unsigned int queue_io_min(struct request_queue *q) 974 { 975 return q->limits.io_min; 976 } 977 978 static inline int bdev_io_min(struct block_device *bdev) 979 { 980 return queue_io_min(bdev_get_queue(bdev)); 981 } 982 983 static inline unsigned int queue_io_opt(struct request_queue *q) 984 { 985 return q->limits.io_opt; 986 } 987 988 static inline int bdev_io_opt(struct block_device *bdev) 989 { 990 return queue_io_opt(bdev_get_queue(bdev)); 991 } 992 993 static inline int queue_alignment_offset(struct request_queue *q) 994 { 995 if (q->limits.misaligned) 996 return -1; 997 998 return q->limits.alignment_offset; 999 } 1000 1001 static inline int queue_limit_alignment_offset(struct queue_limits *lim, sector_t sector) 1002 { 1003 unsigned int granularity = max(lim->physical_block_size, lim->io_min); 1004 unsigned int alignment = (sector << 9) & (granularity - 1); 1005 1006 return (granularity + lim->alignment_offset - alignment) 1007 & (granularity - 1); 1008 } 1009 1010 static inline int bdev_alignment_offset(struct block_device *bdev) 1011 { 1012 struct request_queue *q = bdev_get_queue(bdev); 1013 1014 if (q->limits.misaligned) 1015 return -1; 1016 1017 if (bdev != bdev->bd_contains) 1018 return bdev->bd_part->alignment_offset; 1019 1020 return q->limits.alignment_offset; 1021 } 1022 1023 static inline int queue_discard_alignment(struct request_queue *q) 1024 { 1025 if (q->limits.discard_misaligned) 1026 return -1; 1027 1028 return q->limits.discard_alignment; 1029 } 1030 1031 static inline int queue_limit_discard_alignment(struct queue_limits *lim, sector_t sector) 1032 { 1033 unsigned int alignment = (sector << 9) & (lim->discard_granularity - 1); 1034 1035 return (lim->discard_granularity + lim->discard_alignment - alignment) 1036 & (lim->discard_granularity - 1); 1037 } 1038 1039 static inline unsigned int queue_discard_zeroes_data(struct request_queue *q) 1040 { 1041 if (q->limits.discard_zeroes_data == 1) 1042 return 1; 1043 1044 return 0; 1045 } 1046 1047 static inline unsigned int bdev_discard_zeroes_data(struct block_device *bdev) 1048 { 1049 return queue_discard_zeroes_data(bdev_get_queue(bdev)); 1050 } 1051 1052 static inline int queue_dma_alignment(struct request_queue *q) 1053 { 1054 return q ? q->dma_alignment : 511; 1055 } 1056 1057 static inline int blk_rq_aligned(struct request_queue *q, unsigned long addr, 1058 unsigned int len) 1059 { 1060 unsigned int alignment = queue_dma_alignment(q) | q->dma_pad_mask; 1061 return !(addr & alignment) && !(len & alignment); 1062 } 1063 1064 /* assumes size > 256 */ 1065 static inline unsigned int blksize_bits(unsigned int size) 1066 { 1067 unsigned int bits = 8; 1068 do { 1069 bits++; 1070 size >>= 1; 1071 } while (size > 256); 1072 return bits; 1073 } 1074 1075 static inline unsigned int block_size(struct block_device *bdev) 1076 { 1077 return bdev->bd_block_size; 1078 } 1079 1080 typedef struct {struct page *v;} Sector; 1081 1082 unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *); 1083 1084 static inline void put_dev_sector(Sector p) 1085 { 1086 page_cache_release(p.v); 1087 } 1088 1089 struct work_struct; 1090 int kblockd_schedule_work(struct request_queue *q, struct work_struct *work); 1091 int kblockd_schedule_delayed_work(struct request_queue *q, struct delayed_work *dwork, unsigned long delay); 1092 1093 #ifdef CONFIG_BLK_CGROUP 1094 /* 1095 * This should not be using sched_clock(). A real patch is in progress 1096 * to fix this up, until that is in place we need to disable preemption 1097 * around sched_clock() in this function and set_io_start_time_ns(). 1098 */ 1099 static inline void set_start_time_ns(struct request *req) 1100 { 1101 preempt_disable(); 1102 req->start_time_ns = sched_clock(); 1103 preempt_enable(); 1104 } 1105 1106 static inline void set_io_start_time_ns(struct request *req) 1107 { 1108 preempt_disable(); 1109 req->io_start_time_ns = sched_clock(); 1110 preempt_enable(); 1111 } 1112 1113 static inline uint64_t rq_start_time_ns(struct request *req) 1114 { 1115 return req->start_time_ns; 1116 } 1117 1118 static inline uint64_t rq_io_start_time_ns(struct request *req) 1119 { 1120 return req->io_start_time_ns; 1121 } 1122 #else 1123 static inline void set_start_time_ns(struct request *req) {} 1124 static inline void set_io_start_time_ns(struct request *req) {} 1125 static inline uint64_t rq_start_time_ns(struct request *req) 1126 { 1127 return 0; 1128 } 1129 static inline uint64_t rq_io_start_time_ns(struct request *req) 1130 { 1131 return 0; 1132 } 1133 #endif 1134 1135 #ifdef CONFIG_BLK_DEV_THROTTLING 1136 extern int blk_throtl_init(struct request_queue *q); 1137 extern void blk_throtl_exit(struct request_queue *q); 1138 extern int blk_throtl_bio(struct request_queue *q, struct bio **bio); 1139 extern void throtl_schedule_delayed_work(struct request_queue *q, unsigned long delay); 1140 extern void throtl_shutdown_timer_wq(struct request_queue *q); 1141 #else /* CONFIG_BLK_DEV_THROTTLING */ 1142 static inline int blk_throtl_bio(struct request_queue *q, struct bio **bio) 1143 { 1144 return 0; 1145 } 1146 1147 static inline int blk_throtl_init(struct request_queue *q) { return 0; } 1148 static inline int blk_throtl_exit(struct request_queue *q) { return 0; } 1149 static inline void throtl_schedule_delayed_work(struct request_queue *q, unsigned long delay) {} 1150 static inline void throtl_shutdown_timer_wq(struct request_queue *q) {} 1151 #endif /* CONFIG_BLK_DEV_THROTTLING */ 1152 1153 #define MODULE_ALIAS_BLOCKDEV(major,minor) \ 1154 MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor)) 1155 #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \ 1156 MODULE_ALIAS("block-major-" __stringify(major) "-*") 1157 1158 #if defined(CONFIG_BLK_DEV_INTEGRITY) 1159 1160 #define INTEGRITY_FLAG_READ 2 /* verify data integrity on read */ 1161 #define INTEGRITY_FLAG_WRITE 4 /* generate data integrity on write */ 1162 1163 struct blk_integrity_exchg { 1164 void *prot_buf; 1165 void *data_buf; 1166 sector_t sector; 1167 unsigned int data_size; 1168 unsigned short sector_size; 1169 const char *disk_name; 1170 }; 1171 1172 typedef void (integrity_gen_fn) (struct blk_integrity_exchg *); 1173 typedef int (integrity_vrfy_fn) (struct blk_integrity_exchg *); 1174 typedef void (integrity_set_tag_fn) (void *, void *, unsigned int); 1175 typedef void (integrity_get_tag_fn) (void *, void *, unsigned int); 1176 1177 struct blk_integrity { 1178 integrity_gen_fn *generate_fn; 1179 integrity_vrfy_fn *verify_fn; 1180 integrity_set_tag_fn *set_tag_fn; 1181 integrity_get_tag_fn *get_tag_fn; 1182 1183 unsigned short flags; 1184 unsigned short tuple_size; 1185 unsigned short sector_size; 1186 unsigned short tag_size; 1187 1188 const char *name; 1189 1190 struct kobject kobj; 1191 }; 1192 1193 extern int blk_integrity_register(struct gendisk *, struct blk_integrity *); 1194 extern void blk_integrity_unregister(struct gendisk *); 1195 extern int blk_integrity_compare(struct gendisk *, struct gendisk *); 1196 extern int blk_rq_map_integrity_sg(struct request_queue *, struct bio *, 1197 struct scatterlist *); 1198 extern int blk_rq_count_integrity_sg(struct request_queue *, struct bio *); 1199 extern int blk_integrity_merge_rq(struct request_queue *, struct request *, 1200 struct request *); 1201 extern int blk_integrity_merge_bio(struct request_queue *, struct request *, 1202 struct bio *); 1203 1204 static inline 1205 struct blk_integrity *bdev_get_integrity(struct block_device *bdev) 1206 { 1207 return bdev->bd_disk->integrity; 1208 } 1209 1210 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk) 1211 { 1212 return disk->integrity; 1213 } 1214 1215 static inline int blk_integrity_rq(struct request *rq) 1216 { 1217 if (rq->bio == NULL) 1218 return 0; 1219 1220 return bio_integrity(rq->bio); 1221 } 1222 1223 static inline void blk_queue_max_integrity_segments(struct request_queue *q, 1224 unsigned int segs) 1225 { 1226 q->limits.max_integrity_segments = segs; 1227 } 1228 1229 static inline unsigned short 1230 queue_max_integrity_segments(struct request_queue *q) 1231 { 1232 return q->limits.max_integrity_segments; 1233 } 1234 1235 #else /* CONFIG_BLK_DEV_INTEGRITY */ 1236 1237 #define blk_integrity_rq(rq) (0) 1238 #define blk_rq_count_integrity_sg(a, b) (0) 1239 #define blk_rq_map_integrity_sg(a, b, c) (0) 1240 #define bdev_get_integrity(a) (0) 1241 #define blk_get_integrity(a) (0) 1242 #define blk_integrity_compare(a, b) (0) 1243 #define blk_integrity_register(a, b) (0) 1244 #define blk_integrity_unregister(a) do { } while (0); 1245 #define blk_queue_max_integrity_segments(a, b) do { } while (0); 1246 #define queue_max_integrity_segments(a) (0) 1247 #define blk_integrity_merge_rq(a, b, c) (0) 1248 #define blk_integrity_merge_bio(a, b, c) (0) 1249 1250 #endif /* CONFIG_BLK_DEV_INTEGRITY */ 1251 1252 struct block_device_operations { 1253 int (*open) (struct block_device *, fmode_t); 1254 int (*release) (struct gendisk *, fmode_t); 1255 int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long); 1256 int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long); 1257 int (*direct_access) (struct block_device *, sector_t, 1258 void **, unsigned long *); 1259 int (*media_changed) (struct gendisk *); 1260 void (*unlock_native_capacity) (struct gendisk *); 1261 int (*revalidate_disk) (struct gendisk *); 1262 int (*getgeo)(struct block_device *, struct hd_geometry *); 1263 /* this callback is with swap_lock and sometimes page table lock held */ 1264 void (*swap_slot_free_notify) (struct block_device *, unsigned long); 1265 struct module *owner; 1266 }; 1267 1268 extern int __blkdev_driver_ioctl(struct block_device *, fmode_t, unsigned int, 1269 unsigned long); 1270 #else /* CONFIG_BLOCK */ 1271 /* 1272 * stubs for when the block layer is configured out 1273 */ 1274 #define buffer_heads_over_limit 0 1275 1276 static inline long nr_blockdev_pages(void) 1277 { 1278 return 0; 1279 } 1280 1281 #endif /* CONFIG_BLOCK */ 1282 1283 #endif 1284