1#ifndef _LINUX_BLKDEV_H 2#define _LINUX_BLKDEV_H 3 4#include <linux/sched.h> 5#include <linux/major.h> 6#include <linux/genhd.h> 7#include <linux/list.h> 8#include <linux/timer.h> 9#include <linux/workqueue.h> 10#include <linux/pagemap.h> 11#include <linux/backing-dev.h> 12#include <linux/wait.h> 13#include <linux/mempool.h> 14#include <linux/bio.h> 15#include <linux/module.h> 16#include <linux/stringify.h> 17 18#include <asm/scatterlist.h> 19 20#ifdef CONFIG_LBD 21# include <asm/div64.h> 22# define sector_div(a, b) do_div(a, b) 23#else 24# define sector_div(n, b)( \ 25{ \ 26 int _res; \ 27 _res = (n) % (b); \ 28 (n) /= (b); \ 29 _res; \ 30} \ 31) 32#endif 33 34#ifdef CONFIG_BLOCK 35 36struct scsi_ioctl_command; 37 38struct request_queue; 39typedef struct request_queue request_queue_t; 40struct elevator_queue; 41typedef struct elevator_queue elevator_t; 42struct request_pm_state; 43struct blk_trace; 44 45#define BLKDEV_MIN_RQ 4 46#define BLKDEV_MAX_RQ 128 /* Default maximum */ 47 48/* 49 * This is the per-process anticipatory I/O scheduler state. 50 */ 51struct as_io_context { 52 spinlock_t lock; 53 54 void (*dtor)(struct as_io_context *aic); /* destructor */ 55 void (*exit)(struct as_io_context *aic); /* called on task exit */ 56 57 unsigned long state; 58 atomic_t nr_queued; /* queued reads & sync writes */ 59 atomic_t nr_dispatched; /* number of requests gone to the drivers */ 60 61 /* IO History tracking */ 62 /* Thinktime */ 63 unsigned long last_end_request; 64 unsigned long ttime_total; 65 unsigned long ttime_samples; 66 unsigned long ttime_mean; 67 /* Layout pattern */ 68 unsigned int seek_samples; 69 sector_t last_request_pos; 70 u64 seek_total; 71 sector_t seek_mean; 72}; 73 74struct cfq_queue; 75struct cfq_io_context { 76 struct rb_node rb_node; 77 void *key; 78 79 struct cfq_queue *cfqq[2]; 80 81 struct io_context *ioc; 82 83 unsigned long last_end_request; 84 sector_t last_request_pos; 85 86 unsigned long ttime_total; 87 unsigned long ttime_samples; 88 unsigned long ttime_mean; 89 90 unsigned int seek_samples; 91 u64 seek_total; 92 sector_t seek_mean; 93 94 struct list_head queue_list; 95 96 void (*dtor)(struct io_context *); /* destructor */ 97 void (*exit)(struct io_context *); /* called on task exit */ 98}; 99 100/* 101 * This is the per-process I/O subsystem state. It is refcounted and 102 * kmalloc'ed. Currently all fields are modified in process io context 103 * (apart from the atomic refcount), so require no locking. 104 */ 105struct io_context { 106 atomic_t refcount; 107 struct task_struct *task; 108 109 unsigned int ioprio_changed; 110 111 /* 112 * For request batching 113 */ 114 unsigned long last_waited; /* Time last woken after wait for request */ 115 int nr_batch_requests; /* Number of requests left in the batch */ 116 117 struct as_io_context *aic; 118 struct rb_root cic_root; 119 void *ioc_data; 120}; 121 122void put_io_context(struct io_context *ioc); 123void exit_io_context(void); 124struct io_context *get_io_context(gfp_t gfp_flags, int node); 125void copy_io_context(struct io_context **pdst, struct io_context **psrc); 126void swap_io_context(struct io_context **ioc1, struct io_context **ioc2); 127 128struct request; 129typedef void (rq_end_io_fn)(struct request *, int); 130 131struct request_list { 132 int count[2]; 133 int starved[2]; 134 int elvpriv; 135 mempool_t *rq_pool; 136 wait_queue_head_t wait[2]; 137}; 138 139/* 140 * request command types 141 */ 142enum rq_cmd_type_bits { 143 REQ_TYPE_FS = 1, /* fs request */ 144 REQ_TYPE_BLOCK_PC, /* scsi command */ 145 REQ_TYPE_SENSE, /* sense request */ 146 REQ_TYPE_PM_SUSPEND, /* suspend request */ 147 REQ_TYPE_PM_RESUME, /* resume request */ 148 REQ_TYPE_PM_SHUTDOWN, /* shutdown request */ 149 REQ_TYPE_FLUSH, /* flush request */ 150 REQ_TYPE_SPECIAL, /* driver defined type */ 151 REQ_TYPE_LINUX_BLOCK, /* generic block layer message */ 152 /* 153 * for ATA/ATAPI devices. this really doesn't belong here, ide should 154 * use REQ_TYPE_SPECIAL and use rq->cmd[0] with the range of driver 155 * private REQ_LB opcodes to differentiate what type of request this is 156 */ 157 REQ_TYPE_ATA_CMD, 158 REQ_TYPE_ATA_TASK, 159 REQ_TYPE_ATA_TASKFILE, 160 REQ_TYPE_ATA_PC, 161}; 162 163/* 164 * For request of type REQ_TYPE_LINUX_BLOCK, rq->cmd[0] is the opcode being 165 * sent down (similar to how REQ_TYPE_BLOCK_PC means that ->cmd[] holds a 166 * SCSI cdb. 167 * 168 * 0x00 -> 0x3f are driver private, to be used for whatever purpose they need, 169 * typically to differentiate REQ_TYPE_SPECIAL requests. 170 * 171 */ 172enum { 173 /* 174 * just examples for now 175 */ 176 REQ_LB_OP_EJECT = 0x40, /* eject request */ 177 REQ_LB_OP_FLUSH = 0x41, /* flush device */ 178}; 179 180/* 181 * request type modified bits. first three bits match BIO_RW* bits, important 182 */ 183enum rq_flag_bits { 184 __REQ_RW, /* not set, read. set, write */ 185 __REQ_FAILFAST, /* no low level driver retries */ 186 __REQ_SORTED, /* elevator knows about this request */ 187 __REQ_SOFTBARRIER, /* may not be passed by ioscheduler */ 188 __REQ_HARDBARRIER, /* may not be passed by drive either */ 189 __REQ_FUA, /* forced unit access */ 190 __REQ_NOMERGE, /* don't touch this for merging */ 191 __REQ_STARTED, /* drive already may have started this one */ 192 __REQ_DONTPREP, /* don't call prep for this one */ 193 __REQ_QUEUED, /* uses queueing */ 194 __REQ_ELVPRIV, /* elevator private data attached */ 195 __REQ_FAILED, /* set if the request failed */ 196 __REQ_QUIET, /* don't worry about errors */ 197 __REQ_PREEMPT, /* set for "ide_preempt" requests */ 198 __REQ_ORDERED_COLOR, /* is before or after barrier */ 199 __REQ_RW_SYNC, /* request is sync (O_DIRECT) */ 200 __REQ_ALLOCED, /* request came from our alloc pool */ 201 __REQ_RW_META, /* metadata io request */ 202 __REQ_NR_BITS, /* stops here */ 203}; 204 205#define REQ_RW (1 << __REQ_RW) 206#define REQ_FAILFAST (1 << __REQ_FAILFAST) 207#define REQ_SORTED (1 << __REQ_SORTED) 208#define REQ_SOFTBARRIER (1 << __REQ_SOFTBARRIER) 209#define REQ_HARDBARRIER (1 << __REQ_HARDBARRIER) 210#define REQ_FUA (1 << __REQ_FUA) 211#define REQ_NOMERGE (1 << __REQ_NOMERGE) 212#define REQ_STARTED (1 << __REQ_STARTED) 213#define REQ_DONTPREP (1 << __REQ_DONTPREP) 214#define REQ_QUEUED (1 << __REQ_QUEUED) 215#define REQ_ELVPRIV (1 << __REQ_ELVPRIV) 216#define REQ_FAILED (1 << __REQ_FAILED) 217#define REQ_QUIET (1 << __REQ_QUIET) 218#define REQ_PREEMPT (1 << __REQ_PREEMPT) 219#define REQ_ORDERED_COLOR (1 << __REQ_ORDERED_COLOR) 220#define REQ_RW_SYNC (1 << __REQ_RW_SYNC) 221#define REQ_ALLOCED (1 << __REQ_ALLOCED) 222#define REQ_RW_META (1 << __REQ_RW_META) 223 224#define BLK_MAX_CDB 16 225 226/* 227 * try to put the fields that are referenced together in the same cacheline 228 */ 229struct request { 230 struct list_head queuelist; 231 struct list_head donelist; 232 233 request_queue_t *q; 234 235 unsigned int cmd_flags; 236 enum rq_cmd_type_bits cmd_type; 237 238 /* Maintain bio traversal state for part by part I/O submission. 239 * hard_* are block layer internals, no driver should touch them! 240 */ 241 242 sector_t sector; /* next sector to submit */ 243 sector_t hard_sector; /* next sector to complete */ 244 unsigned long nr_sectors; /* no. of sectors left to submit */ 245 unsigned long hard_nr_sectors; /* no. of sectors left to complete */ 246 /* no. of sectors left to submit in the current segment */ 247 unsigned int current_nr_sectors; 248 249 /* no. of sectors left to complete in the current segment */ 250 unsigned int hard_cur_sectors; 251 252 struct bio *bio; 253 struct bio *biotail; 254 255 struct hlist_node hash; /* merge hash */ 256 /* 257 * The rb_node is only used inside the io scheduler, requests 258 * are pruned when moved to the dispatch queue. So let the 259 * completion_data share space with the rb_node. 260 */ 261 union { 262 struct rb_node rb_node; /* sort/lookup */ 263 void *completion_data; 264 }; 265 266 /* 267 * two pointers are available for the IO schedulers, if they need 268 * more they have to dynamically allocate it. 269 */ 270 void *elevator_private; 271 void *elevator_private2; 272 273 struct gendisk *rq_disk; 274 unsigned long start_time; 275 276 /* Number of scatter-gather DMA addr+len pairs after 277 * physical address coalescing is performed. 278 */ 279 unsigned short nr_phys_segments; 280 281 /* Number of scatter-gather addr+len pairs after 282 * physical and DMA remapping hardware coalescing is performed. 283 * This is the number of scatter-gather entries the driver 284 * will actually have to deal with after DMA mapping is done. 285 */ 286 unsigned short nr_hw_segments; 287 288 unsigned short ioprio; 289 290 void *special; 291 char *buffer; 292 293 int tag; 294 int errors; 295 296 int ref_count; 297 298 /* 299 * when request is used as a packet command carrier 300 */ 301 unsigned int cmd_len; 302 unsigned char cmd[BLK_MAX_CDB]; 303 304 unsigned int data_len; 305 unsigned int sense_len; 306 void *data; 307 void *sense; 308 309 unsigned int timeout; 310 int retries; 311 312 /* 313 * completion callback. 314 */ 315 rq_end_io_fn *end_io; 316 void *end_io_data; 317}; 318 319/* 320 * State information carried for REQ_TYPE_PM_SUSPEND and REQ_TYPE_PM_RESUME 321 * requests. Some step values could eventually be made generic. 322 */ 323struct request_pm_state 324{ 325 /* PM state machine step value, currently driver specific */ 326 int pm_step; 327 /* requested PM state value (S1, S2, S3, S4, ...) */ 328 u32 pm_state; 329 void* data; /* for driver use */ 330}; 331 332#include <linux/elevator.h> 333 334typedef void (request_fn_proc) (request_queue_t *q); 335typedef int (make_request_fn) (request_queue_t *q, struct bio *bio); 336typedef int (prep_rq_fn) (request_queue_t *, struct request *); 337typedef void (unplug_fn) (request_queue_t *); 338 339struct bio_vec; 340typedef int (merge_bvec_fn) (request_queue_t *, struct bio *, struct bio_vec *); 341typedef int (issue_flush_fn) (request_queue_t *, struct gendisk *, sector_t *); 342typedef void (prepare_flush_fn) (request_queue_t *, struct request *); 343typedef void (softirq_done_fn)(struct request *); 344 345enum blk_queue_state { 346 Queue_down, 347 Queue_up, 348}; 349 350struct blk_queue_tag { 351 struct request **tag_index; /* map of busy tags */ 352 unsigned long *tag_map; /* bit map of free/busy tags */ 353 struct list_head busy_list; /* fifo list of busy tags */ 354 int busy; /* current depth */ 355 int max_depth; /* what we will send to device */ 356 int real_max_depth; /* what the array can hold */ 357 atomic_t refcnt; /* map can be shared */ 358}; 359 360struct request_queue 361{ 362 /* 363 * Together with queue_head for cacheline sharing 364 */ 365 struct list_head queue_head; 366 struct request *last_merge; 367 elevator_t *elevator; 368 369 /* 370 * the queue request freelist, one for reads and one for writes 371 */ 372 struct request_list rq; 373 374 request_fn_proc *request_fn; 375 make_request_fn *make_request_fn; 376 prep_rq_fn *prep_rq_fn; 377 unplug_fn *unplug_fn; 378 merge_bvec_fn *merge_bvec_fn; 379 issue_flush_fn *issue_flush_fn; 380 prepare_flush_fn *prepare_flush_fn; 381 softirq_done_fn *softirq_done_fn; 382 383 /* 384 * Dispatch queue sorting 385 */ 386 sector_t end_sector; 387 struct request *boundary_rq; 388 389 /* 390 * Auto-unplugging state 391 */ 392 struct timer_list unplug_timer; 393 int unplug_thresh; /* After this many requests */ 394 unsigned long unplug_delay; /* After this many jiffies */ 395 struct work_struct unplug_work; 396 397 struct backing_dev_info backing_dev_info; 398 399 /* 400 * The queue owner gets to use this for whatever they like. 401 * ll_rw_blk doesn't touch it. 402 */ 403 void *queuedata; 404 405 /* 406 * queue needs bounce pages for pages above this limit 407 */ 408 unsigned long bounce_pfn; 409 gfp_t bounce_gfp; 410 411 /* 412 * various queue flags, see QUEUE_* below 413 */ 414 unsigned long queue_flags; 415 416 /* 417 * protects queue structures from reentrancy. ->__queue_lock should 418 * _never_ be used directly, it is queue private. always use 419 * ->queue_lock. 420 */ 421 spinlock_t __queue_lock; 422 spinlock_t *queue_lock; 423 424 /* 425 * queue kobject 426 */ 427 struct kobject kobj; 428 429 /* 430 * queue settings 431 */ 432 unsigned long nr_requests; /* Max # of requests */ 433 unsigned int nr_congestion_on; 434 unsigned int nr_congestion_off; 435 unsigned int nr_batching; 436 437 unsigned int max_sectors; 438 unsigned int max_hw_sectors; 439 unsigned short max_phys_segments; 440 unsigned short max_hw_segments; 441 unsigned short hardsect_size; 442 unsigned int max_segment_size; 443 444 unsigned long seg_boundary_mask; 445 unsigned int dma_alignment; 446 447 struct blk_queue_tag *queue_tags; 448 449 unsigned int nr_sorted; 450 unsigned int in_flight; 451 452 /* 453 * sg stuff 454 */ 455 unsigned int sg_timeout; 456 unsigned int sg_reserved_size; 457 int node; 458#ifdef CONFIG_BLK_DEV_IO_TRACE 459 struct blk_trace *blk_trace; 460#endif 461 /* 462 * reserved for flush operations 463 */ 464 unsigned int ordered, next_ordered, ordseq; 465 int orderr, ordcolor; 466 struct request pre_flush_rq, bar_rq, post_flush_rq; 467 struct request *orig_bar_rq; 468 unsigned int bi_size; 469 470 struct mutex sysfs_lock; 471}; 472 473#define QUEUE_FLAG_CLUSTER 0 /* cluster several segments into 1 */ 474#define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */ 475#define QUEUE_FLAG_STOPPED 2 /* queue is stopped */ 476#define QUEUE_FLAG_READFULL 3 /* write queue has been filled */ 477#define QUEUE_FLAG_WRITEFULL 4 /* read queue has been filled */ 478#define QUEUE_FLAG_DEAD 5 /* queue being torn down */ 479#define QUEUE_FLAG_REENTER 6 /* Re-entrancy avoidance */ 480#define QUEUE_FLAG_PLUGGED 7 /* queue is plugged */ 481#define QUEUE_FLAG_ELVSWITCH 8 /* don't use elevator, just do FIFO */ 482 483enum { 484 /* 485 * Hardbarrier is supported with one of the following methods. 486 * 487 * NONE : hardbarrier unsupported 488 * DRAIN : ordering by draining is enough 489 * DRAIN_FLUSH : ordering by draining w/ pre and post flushes 490 * DRAIN_FUA : ordering by draining w/ pre flush and FUA write 491 * TAG : ordering by tag is enough 492 * TAG_FLUSH : ordering by tag w/ pre and post flushes 493 * TAG_FUA : ordering by tag w/ pre flush and FUA write 494 */ 495 QUEUE_ORDERED_NONE = 0x00, 496 QUEUE_ORDERED_DRAIN = 0x01, 497 QUEUE_ORDERED_TAG = 0x02, 498 499 QUEUE_ORDERED_PREFLUSH = 0x10, 500 QUEUE_ORDERED_POSTFLUSH = 0x20, 501 QUEUE_ORDERED_FUA = 0x40, 502 503 QUEUE_ORDERED_DRAIN_FLUSH = QUEUE_ORDERED_DRAIN | 504 QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_POSTFLUSH, 505 QUEUE_ORDERED_DRAIN_FUA = QUEUE_ORDERED_DRAIN | 506 QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_FUA, 507 QUEUE_ORDERED_TAG_FLUSH = QUEUE_ORDERED_TAG | 508 QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_POSTFLUSH, 509 QUEUE_ORDERED_TAG_FUA = QUEUE_ORDERED_TAG | 510 QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_FUA, 511 512 /* 513 * Ordered operation sequence 514 */ 515 QUEUE_ORDSEQ_STARTED = 0x01, /* flushing in progress */ 516 QUEUE_ORDSEQ_DRAIN = 0x02, /* waiting for the queue to be drained */ 517 QUEUE_ORDSEQ_PREFLUSH = 0x04, /* pre-flushing in progress */ 518 QUEUE_ORDSEQ_BAR = 0x08, /* original barrier req in progress */ 519 QUEUE_ORDSEQ_POSTFLUSH = 0x10, /* post-flushing in progress */ 520 QUEUE_ORDSEQ_DONE = 0x20, 521}; 522 523#define blk_queue_plugged(q) test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags) 524#define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags) 525#define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags) 526#define blk_queue_flushing(q) ((q)->ordseq) 527 528#define blk_fs_request(rq) ((rq)->cmd_type == REQ_TYPE_FS) 529#define blk_pc_request(rq) ((rq)->cmd_type == REQ_TYPE_BLOCK_PC) 530#define blk_special_request(rq) ((rq)->cmd_type == REQ_TYPE_SPECIAL) 531#define blk_sense_request(rq) ((rq)->cmd_type == REQ_TYPE_SENSE) 532 533#define blk_noretry_request(rq) ((rq)->cmd_flags & REQ_FAILFAST) 534#define blk_rq_started(rq) ((rq)->cmd_flags & REQ_STARTED) 535 536#define blk_account_rq(rq) (blk_rq_started(rq) && blk_fs_request(rq)) 537 538#define blk_pm_suspend_request(rq) ((rq)->cmd_type == REQ_TYPE_PM_SUSPEND) 539#define blk_pm_resume_request(rq) ((rq)->cmd_type == REQ_TYPE_PM_RESUME) 540#define blk_pm_request(rq) \ 541 (blk_pm_suspend_request(rq) || blk_pm_resume_request(rq)) 542 543#define blk_sorted_rq(rq) ((rq)->cmd_flags & REQ_SORTED) 544#define blk_barrier_rq(rq) ((rq)->cmd_flags & REQ_HARDBARRIER) 545#define blk_fua_rq(rq) ((rq)->cmd_flags & REQ_FUA) 546 547#define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist) 548 549#define rq_data_dir(rq) ((rq)->cmd_flags & 1) 550 551/* 552 * We regard a request as sync, if it's a READ or a SYNC write. 553 */ 554#define rq_is_sync(rq) (rq_data_dir((rq)) == READ || (rq)->cmd_flags & REQ_RW_SYNC) 555#define rq_is_meta(rq) ((rq)->cmd_flags & REQ_RW_META) 556 557static inline int blk_queue_full(struct request_queue *q, int rw) 558{ 559 if (rw == READ) 560 return test_bit(QUEUE_FLAG_READFULL, &q->queue_flags); 561 return test_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags); 562} 563 564static inline void blk_set_queue_full(struct request_queue *q, int rw) 565{ 566 if (rw == READ) 567 set_bit(QUEUE_FLAG_READFULL, &q->queue_flags); 568 else 569 set_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags); 570} 571 572static inline void blk_clear_queue_full(struct request_queue *q, int rw) 573{ 574 if (rw == READ) 575 clear_bit(QUEUE_FLAG_READFULL, &q->queue_flags); 576 else 577 clear_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags); 578} 579 580 581/* 582 * mergeable request must not have _NOMERGE or _BARRIER bit set, nor may 583 * it already be started by driver. 584 */ 585#define RQ_NOMERGE_FLAGS \ 586 (REQ_NOMERGE | REQ_STARTED | REQ_HARDBARRIER | REQ_SOFTBARRIER) 587#define rq_mergeable(rq) \ 588 (!((rq)->cmd_flags & RQ_NOMERGE_FLAGS) && blk_fs_request((rq))) 589 590/* 591 * q->prep_rq_fn return values 592 */ 593#define BLKPREP_OK 0 /* serve it */ 594#define BLKPREP_KILL 1 /* fatal error, kill */ 595#define BLKPREP_DEFER 2 /* leave on queue */ 596 597extern unsigned long blk_max_low_pfn, blk_max_pfn; 598 599/* 600 * standard bounce addresses: 601 * 602 * BLK_BOUNCE_HIGH : bounce all highmem pages 603 * BLK_BOUNCE_ANY : don't bounce anything 604 * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary 605 */ 606#define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT) 607#define BLK_BOUNCE_ANY ((u64)blk_max_pfn << PAGE_SHIFT) 608#define BLK_BOUNCE_ISA (ISA_DMA_THRESHOLD) 609 610#ifdef CONFIG_MMU 611extern int init_emergency_isa_pool(void); 612extern void blk_queue_bounce(request_queue_t *q, struct bio **bio); 613#else 614static inline int init_emergency_isa_pool(void) 615{ 616 return 0; 617} 618static inline void blk_queue_bounce(request_queue_t *q, struct bio **bio) 619{ 620} 621#endif /* CONFIG_MMU */ 622 623#define rq_for_each_bio(_bio, rq) \ 624 if ((rq->bio)) \ 625 for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next) 626 627extern int blk_register_queue(struct gendisk *disk); 628extern void blk_unregister_queue(struct gendisk *disk); 629extern void register_disk(struct gendisk *dev); 630extern void generic_make_request(struct bio *bio); 631extern void blk_put_request(struct request *); 632extern void __blk_put_request(request_queue_t *, struct request *); 633extern void blk_end_sync_rq(struct request *rq, int error); 634extern struct request *blk_get_request(request_queue_t *, int, gfp_t); 635extern void blk_insert_request(request_queue_t *, struct request *, int, void *); 636extern void blk_requeue_request(request_queue_t *, struct request *); 637extern void blk_plug_device(request_queue_t *); 638extern int blk_remove_plug(request_queue_t *); 639extern void blk_recount_segments(request_queue_t *, struct bio *); 640extern int scsi_cmd_ioctl(struct file *, struct gendisk *, unsigned int, void __user *); 641extern int sg_scsi_ioctl(struct file *, struct request_queue *, 642 struct gendisk *, struct scsi_ioctl_command __user *); 643 644/* 645 * Temporary export, until SCSI gets fixed up. 646 */ 647extern int ll_back_merge_fn(request_queue_t *, struct request *, struct bio *); 648 649/* 650 * A queue has just exitted congestion. Note this in the global counter of 651 * congested queues, and wake up anyone who was waiting for requests to be 652 * put back. 653 */ 654static inline void blk_clear_queue_congested(request_queue_t *q, int rw) 655{ 656 clear_bdi_congested(&q->backing_dev_info, rw); 657} 658 659/* 660 * A queue has just entered congestion. Flag that in the queue's VM-visible 661 * state flags and increment the global gounter of congested queues. 662 */ 663static inline void blk_set_queue_congested(request_queue_t *q, int rw) 664{ 665 set_bdi_congested(&q->backing_dev_info, rw); 666} 667 668extern void blk_start_queue(request_queue_t *q); 669extern void blk_stop_queue(request_queue_t *q); 670extern void blk_sync_queue(struct request_queue *q); 671extern void __blk_stop_queue(request_queue_t *q); 672extern void blk_run_queue(request_queue_t *); 673extern void blk_start_queueing(request_queue_t *); 674extern int blk_rq_map_user(request_queue_t *, struct request *, void __user *, unsigned long); 675extern int blk_rq_unmap_user(struct bio *); 676extern int blk_rq_map_kern(request_queue_t *, struct request *, void *, unsigned int, gfp_t); 677extern int blk_rq_map_user_iov(request_queue_t *, struct request *, 678 struct sg_iovec *, int, unsigned int); 679extern int blk_execute_rq(request_queue_t *, struct gendisk *, 680 struct request *, int); 681extern void blk_execute_rq_nowait(request_queue_t *, struct gendisk *, 682 struct request *, int, rq_end_io_fn *); 683 684static inline request_queue_t *bdev_get_queue(struct block_device *bdev) 685{ 686 return bdev->bd_disk->queue; 687} 688 689static inline void blk_run_backing_dev(struct backing_dev_info *bdi, 690 struct page *page) 691{ 692 if (bdi && bdi->unplug_io_fn) 693 bdi->unplug_io_fn(bdi, page); 694} 695 696static inline void blk_run_address_space(struct address_space *mapping) 697{ 698 if (mapping) 699 blk_run_backing_dev(mapping->backing_dev_info, NULL); 700} 701 702/* 703 * end_request() and friends. Must be called with the request queue spinlock 704 * acquired. All functions called within end_request() _must_be_ atomic. 705 * 706 * Several drivers define their own end_request and call 707 * end_that_request_first() and end_that_request_last() 708 * for parts of the original function. This prevents 709 * code duplication in drivers. 710 */ 711extern int end_that_request_first(struct request *, int, int); 712extern int end_that_request_chunk(struct request *, int, int); 713extern void end_that_request_last(struct request *, int); 714extern void end_request(struct request *req, int uptodate); 715extern void blk_complete_request(struct request *); 716 717/* 718 * end_that_request_first/chunk() takes an uptodate argument. we account 719 * any value <= as an io error. 0 means -EIO for compatability reasons, 720 * any other < 0 value is the direct error type. An uptodate value of 721 * 1 indicates successful io completion 722 */ 723#define end_io_error(uptodate) (unlikely((uptodate) <= 0)) 724 725static inline void blkdev_dequeue_request(struct request *req) 726{ 727 elv_dequeue_request(req->q, req); 728} 729 730/* 731 * Access functions for manipulating queue properties 732 */ 733extern request_queue_t *blk_init_queue_node(request_fn_proc *rfn, 734 spinlock_t *lock, int node_id); 735extern request_queue_t *blk_init_queue(request_fn_proc *, spinlock_t *); 736extern void blk_cleanup_queue(request_queue_t *); 737extern void blk_queue_make_request(request_queue_t *, make_request_fn *); 738extern void blk_queue_bounce_limit(request_queue_t *, u64); 739extern void blk_queue_max_sectors(request_queue_t *, unsigned int); 740extern void blk_queue_max_phys_segments(request_queue_t *, unsigned short); 741extern void blk_queue_max_hw_segments(request_queue_t *, unsigned short); 742extern void blk_queue_max_segment_size(request_queue_t *, unsigned int); 743extern void blk_queue_hardsect_size(request_queue_t *, unsigned short); 744extern void blk_queue_stack_limits(request_queue_t *t, request_queue_t *b); 745extern void blk_queue_segment_boundary(request_queue_t *, unsigned long); 746extern void blk_queue_prep_rq(request_queue_t *, prep_rq_fn *pfn); 747extern void blk_queue_merge_bvec(request_queue_t *, merge_bvec_fn *); 748extern void blk_queue_dma_alignment(request_queue_t *, int); 749extern void blk_queue_softirq_done(request_queue_t *, softirq_done_fn *); 750extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev); 751extern int blk_queue_ordered(request_queue_t *, unsigned, prepare_flush_fn *); 752extern void blk_queue_issue_flush_fn(request_queue_t *, issue_flush_fn *); 753extern int blk_do_ordered(request_queue_t *, struct request **); 754extern unsigned blk_ordered_cur_seq(request_queue_t *); 755extern unsigned blk_ordered_req_seq(struct request *); 756extern void blk_ordered_complete_seq(request_queue_t *, unsigned, int); 757 758extern int blk_rq_map_sg(request_queue_t *, struct request *, struct scatterlist *); 759extern void blk_dump_rq_flags(struct request *, char *); 760extern void generic_unplug_device(request_queue_t *); 761extern void __generic_unplug_device(request_queue_t *); 762extern long nr_blockdev_pages(void); 763 764int blk_get_queue(request_queue_t *); 765request_queue_t *blk_alloc_queue(gfp_t); 766request_queue_t *blk_alloc_queue_node(gfp_t, int); 767extern void blk_put_queue(request_queue_t *); 768 769/* 770 * tag stuff 771 */ 772#define blk_queue_tag_depth(q) ((q)->queue_tags->busy) 773#define blk_queue_tag_queue(q) ((q)->queue_tags->busy < (q)->queue_tags->max_depth) 774#define blk_rq_tagged(rq) ((rq)->cmd_flags & REQ_QUEUED) 775extern int blk_queue_start_tag(request_queue_t *, struct request *); 776extern struct request *blk_queue_find_tag(request_queue_t *, int); 777extern void blk_queue_end_tag(request_queue_t *, struct request *); 778extern int blk_queue_init_tags(request_queue_t *, int, struct blk_queue_tag *); 779extern void blk_queue_free_tags(request_queue_t *); 780extern int blk_queue_resize_tags(request_queue_t *, int); 781extern void blk_queue_invalidate_tags(request_queue_t *); 782extern struct blk_queue_tag *blk_init_tags(int); 783extern void blk_free_tags(struct blk_queue_tag *); 784 785static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt, 786 int tag) 787{ 788 if (unlikely(bqt == NULL || tag >= bqt->real_max_depth)) 789 return NULL; 790 return bqt->tag_index[tag]; 791} 792 793extern void blk_rq_bio_prep(request_queue_t *, struct request *, struct bio *); 794extern int blkdev_issue_flush(struct block_device *, sector_t *); 795 796#define MAX_PHYS_SEGMENTS 128 797#define MAX_HW_SEGMENTS 128 798#define SAFE_MAX_SECTORS 255 799#define BLK_DEF_MAX_SECTORS 1024 800 801#define MAX_SEGMENT_SIZE 65536 802 803#define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist) 804 805static inline int queue_hardsect_size(request_queue_t *q) 806{ 807 int retval = 512; 808 809 if (q && q->hardsect_size) 810 retval = q->hardsect_size; 811 812 return retval; 813} 814 815static inline int bdev_hardsect_size(struct block_device *bdev) 816{ 817 return queue_hardsect_size(bdev_get_queue(bdev)); 818} 819 820static inline int queue_dma_alignment(request_queue_t *q) 821{ 822 int retval = 511; 823 824 if (q && q->dma_alignment) 825 retval = q->dma_alignment; 826 827 return retval; 828} 829 830/* assumes size > 256 */ 831static inline unsigned int blksize_bits(unsigned int size) 832{ 833 unsigned int bits = 8; 834 do { 835 bits++; 836 size >>= 1; 837 } while (size > 256); 838 return bits; 839} 840 841static inline unsigned int block_size(struct block_device *bdev) 842{ 843 return bdev->bd_block_size; 844} 845 846typedef struct {struct page *v;} Sector; 847 848unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *); 849 850static inline void put_dev_sector(Sector p) 851{ 852 page_cache_release(p.v); 853} 854 855struct work_struct; 856int kblockd_schedule_work(struct work_struct *work); 857void kblockd_flush_work(struct work_struct *work); 858 859#define MODULE_ALIAS_BLOCKDEV(major,minor) \ 860 MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor)) 861#define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \ 862 MODULE_ALIAS("block-major-" __stringify(major) "-*") 863 864 865#else /* CONFIG_BLOCK */ 866/* 867 * stubs for when the block layer is configured out 868 */ 869#define buffer_heads_over_limit 0 870 871static inline long blk_congestion_wait(int rw, long timeout) 872{ 873 return io_schedule_timeout(timeout); 874} 875 876static inline long nr_blockdev_pages(void) 877{ 878 return 0; 879} 880 881static inline void exit_io_context(void) 882{ 883} 884 885#endif /* CONFIG_BLOCK */ 886 887#endif 888