1 #ifndef _LINUX_BLKDEV_H 2 #define _LINUX_BLKDEV_H 3 4 #include <linux/config.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 struct scsi_ioctl_command; 21 22 struct request_queue; 23 typedef struct request_queue request_queue_t; 24 struct elevator_queue; 25 typedef struct elevator_queue elevator_t; 26 struct request_pm_state; 27 struct blk_trace; 28 29 #define BLKDEV_MIN_RQ 4 30 #define BLKDEV_MAX_RQ 128 /* Default maximum */ 31 32 /* 33 * This is the per-process anticipatory I/O scheduler state. 34 */ 35 struct as_io_context { 36 spinlock_t lock; 37 38 void (*dtor)(struct as_io_context *aic); /* destructor */ 39 void (*exit)(struct as_io_context *aic); /* called on task exit */ 40 41 unsigned long state; 42 atomic_t nr_queued; /* queued reads & sync writes */ 43 atomic_t nr_dispatched; /* number of requests gone to the drivers */ 44 45 /* IO History tracking */ 46 /* Thinktime */ 47 unsigned long last_end_request; 48 unsigned long ttime_total; 49 unsigned long ttime_samples; 50 unsigned long ttime_mean; 51 /* Layout pattern */ 52 unsigned int seek_samples; 53 sector_t last_request_pos; 54 u64 seek_total; 55 sector_t seek_mean; 56 }; 57 58 struct cfq_queue; 59 struct cfq_io_context { 60 struct rb_node rb_node; 61 void *key; 62 63 struct cfq_queue *cfqq[2]; 64 65 struct io_context *ioc; 66 67 unsigned long last_end_request; 68 sector_t last_request_pos; 69 unsigned long last_queue; 70 71 unsigned long ttime_total; 72 unsigned long ttime_samples; 73 unsigned long ttime_mean; 74 75 unsigned int seek_samples; 76 u64 seek_total; 77 sector_t seek_mean; 78 79 struct list_head queue_list; 80 81 void (*dtor)(struct io_context *); /* destructor */ 82 void (*exit)(struct io_context *); /* called on task exit */ 83 }; 84 85 /* 86 * This is the per-process I/O subsystem state. It is refcounted and 87 * kmalloc'ed. Currently all fields are modified in process io context 88 * (apart from the atomic refcount), so require no locking. 89 */ 90 struct io_context { 91 atomic_t refcount; 92 struct task_struct *task; 93 94 int (*set_ioprio)(struct io_context *, unsigned int); 95 96 /* 97 * For request batching 98 */ 99 unsigned long last_waited; /* Time last woken after wait for request */ 100 int nr_batch_requests; /* Number of requests left in the batch */ 101 102 struct as_io_context *aic; 103 struct rb_root cic_root; 104 }; 105 106 void put_io_context(struct io_context *ioc); 107 void exit_io_context(void); 108 struct io_context *current_io_context(gfp_t gfp_flags); 109 struct io_context *get_io_context(gfp_t gfp_flags); 110 void copy_io_context(struct io_context **pdst, struct io_context **psrc); 111 void swap_io_context(struct io_context **ioc1, struct io_context **ioc2); 112 113 struct request; 114 typedef void (rq_end_io_fn)(struct request *, int); 115 116 struct request_list { 117 int count[2]; 118 int starved[2]; 119 int elvpriv; 120 mempool_t *rq_pool; 121 wait_queue_head_t wait[2]; 122 }; 123 124 #define BLK_MAX_CDB 16 125 126 /* 127 * try to put the fields that are referenced together in the same cacheline 128 */ 129 struct request { 130 struct list_head queuelist; 131 struct list_head donelist; 132 133 unsigned long flags; /* see REQ_ bits below */ 134 135 /* Maintain bio traversal state for part by part I/O submission. 136 * hard_* are block layer internals, no driver should touch them! 137 */ 138 139 sector_t sector; /* next sector to submit */ 140 unsigned long nr_sectors; /* no. of sectors left to submit */ 141 /* no. of sectors left to submit in the current segment */ 142 unsigned int current_nr_sectors; 143 144 sector_t hard_sector; /* next sector to complete */ 145 unsigned long hard_nr_sectors; /* no. of sectors left to complete */ 146 /* no. of sectors left to complete in the current segment */ 147 unsigned int hard_cur_sectors; 148 149 struct bio *bio; 150 struct bio *biotail; 151 152 void *elevator_private; 153 void *completion_data; 154 155 unsigned short ioprio; 156 157 int rq_status; /* should split this into a few status bits */ 158 struct gendisk *rq_disk; 159 int errors; 160 unsigned long start_time; 161 162 /* Number of scatter-gather DMA addr+len pairs after 163 * physical address coalescing is performed. 164 */ 165 unsigned short nr_phys_segments; 166 167 /* Number of scatter-gather addr+len pairs after 168 * physical and DMA remapping hardware coalescing is performed. 169 * This is the number of scatter-gather entries the driver 170 * will actually have to deal with after DMA mapping is done. 171 */ 172 unsigned short nr_hw_segments; 173 174 int tag; 175 char *buffer; 176 177 int ref_count; 178 request_queue_t *q; 179 struct request_list *rl; 180 181 struct completion *waiting; 182 void *special; 183 184 /* 185 * when request is used as a packet command carrier 186 */ 187 unsigned int cmd_len; 188 unsigned char cmd[BLK_MAX_CDB]; 189 190 unsigned int data_len; 191 void *data; 192 193 unsigned int sense_len; 194 void *sense; 195 196 unsigned int timeout; 197 int retries; 198 199 /* 200 * For Power Management requests 201 */ 202 struct request_pm_state *pm; 203 204 /* 205 * completion callback. end_io_data should be folded in with waiting 206 */ 207 rq_end_io_fn *end_io; 208 void *end_io_data; 209 }; 210 211 /* 212 * first three bits match BIO_RW* bits, important 213 */ 214 enum rq_flag_bits { 215 __REQ_RW, /* not set, read. set, write */ 216 __REQ_FAILFAST, /* no low level driver retries */ 217 __REQ_SORTED, /* elevator knows about this request */ 218 __REQ_SOFTBARRIER, /* may not be passed by ioscheduler */ 219 __REQ_HARDBARRIER, /* may not be passed by drive either */ 220 __REQ_FUA, /* forced unit access */ 221 __REQ_CMD, /* is a regular fs rw request */ 222 __REQ_NOMERGE, /* don't touch this for merging */ 223 __REQ_STARTED, /* drive already may have started this one */ 224 __REQ_DONTPREP, /* don't call prep for this one */ 225 __REQ_QUEUED, /* uses queueing */ 226 __REQ_ELVPRIV, /* elevator private data attached */ 227 /* 228 * for ATA/ATAPI devices 229 */ 230 __REQ_PC, /* packet command (special) */ 231 __REQ_BLOCK_PC, /* queued down pc from block layer */ 232 __REQ_SENSE, /* sense retrival */ 233 234 __REQ_FAILED, /* set if the request failed */ 235 __REQ_QUIET, /* don't worry about errors */ 236 __REQ_SPECIAL, /* driver suplied command */ 237 __REQ_DRIVE_CMD, 238 __REQ_DRIVE_TASK, 239 __REQ_DRIVE_TASKFILE, 240 __REQ_PREEMPT, /* set for "ide_preempt" requests */ 241 __REQ_PM_SUSPEND, /* suspend request */ 242 __REQ_PM_RESUME, /* resume request */ 243 __REQ_PM_SHUTDOWN, /* shutdown request */ 244 __REQ_ORDERED_COLOR, /* is before or after barrier */ 245 __REQ_NR_BITS, /* stops here */ 246 }; 247 248 #define REQ_RW (1 << __REQ_RW) 249 #define REQ_FAILFAST (1 << __REQ_FAILFAST) 250 #define REQ_SORTED (1 << __REQ_SORTED) 251 #define REQ_SOFTBARRIER (1 << __REQ_SOFTBARRIER) 252 #define REQ_HARDBARRIER (1 << __REQ_HARDBARRIER) 253 #define REQ_FUA (1 << __REQ_FUA) 254 #define REQ_CMD (1 << __REQ_CMD) 255 #define REQ_NOMERGE (1 << __REQ_NOMERGE) 256 #define REQ_STARTED (1 << __REQ_STARTED) 257 #define REQ_DONTPREP (1 << __REQ_DONTPREP) 258 #define REQ_QUEUED (1 << __REQ_QUEUED) 259 #define REQ_ELVPRIV (1 << __REQ_ELVPRIV) 260 #define REQ_PC (1 << __REQ_PC) 261 #define REQ_BLOCK_PC (1 << __REQ_BLOCK_PC) 262 #define REQ_SENSE (1 << __REQ_SENSE) 263 #define REQ_FAILED (1 << __REQ_FAILED) 264 #define REQ_QUIET (1 << __REQ_QUIET) 265 #define REQ_SPECIAL (1 << __REQ_SPECIAL) 266 #define REQ_DRIVE_CMD (1 << __REQ_DRIVE_CMD) 267 #define REQ_DRIVE_TASK (1 << __REQ_DRIVE_TASK) 268 #define REQ_DRIVE_TASKFILE (1 << __REQ_DRIVE_TASKFILE) 269 #define REQ_PREEMPT (1 << __REQ_PREEMPT) 270 #define REQ_PM_SUSPEND (1 << __REQ_PM_SUSPEND) 271 #define REQ_PM_RESUME (1 << __REQ_PM_RESUME) 272 #define REQ_PM_SHUTDOWN (1 << __REQ_PM_SHUTDOWN) 273 #define REQ_ORDERED_COLOR (1 << __REQ_ORDERED_COLOR) 274 275 /* 276 * State information carried for REQ_PM_SUSPEND and REQ_PM_RESUME 277 * requests. Some step values could eventually be made generic. 278 */ 279 struct request_pm_state 280 { 281 /* PM state machine step value, currently driver specific */ 282 int pm_step; 283 /* requested PM state value (S1, S2, S3, S4, ...) */ 284 u32 pm_state; 285 void* data; /* for driver use */ 286 }; 287 288 #include <linux/elevator.h> 289 290 typedef int (merge_request_fn) (request_queue_t *, struct request *, 291 struct bio *); 292 typedef int (merge_requests_fn) (request_queue_t *, struct request *, 293 struct request *); 294 typedef void (request_fn_proc) (request_queue_t *q); 295 typedef int (make_request_fn) (request_queue_t *q, struct bio *bio); 296 typedef int (prep_rq_fn) (request_queue_t *, struct request *); 297 typedef void (unplug_fn) (request_queue_t *); 298 299 struct bio_vec; 300 typedef int (merge_bvec_fn) (request_queue_t *, struct bio *, struct bio_vec *); 301 typedef void (activity_fn) (void *data, int rw); 302 typedef int (issue_flush_fn) (request_queue_t *, struct gendisk *, sector_t *); 303 typedef void (prepare_flush_fn) (request_queue_t *, struct request *); 304 typedef void (softirq_done_fn)(struct request *); 305 306 enum blk_queue_state { 307 Queue_down, 308 Queue_up, 309 }; 310 311 struct blk_queue_tag { 312 struct request **tag_index; /* map of busy tags */ 313 unsigned long *tag_map; /* bit map of free/busy tags */ 314 struct list_head busy_list; /* fifo list of busy tags */ 315 int busy; /* current depth */ 316 int max_depth; /* what we will send to device */ 317 int real_max_depth; /* what the array can hold */ 318 atomic_t refcnt; /* map can be shared */ 319 }; 320 321 struct request_queue 322 { 323 /* 324 * Together with queue_head for cacheline sharing 325 */ 326 struct list_head queue_head; 327 struct request *last_merge; 328 elevator_t *elevator; 329 330 /* 331 * the queue request freelist, one for reads and one for writes 332 */ 333 struct request_list rq; 334 335 request_fn_proc *request_fn; 336 merge_request_fn *back_merge_fn; 337 merge_request_fn *front_merge_fn; 338 merge_requests_fn *merge_requests_fn; 339 make_request_fn *make_request_fn; 340 prep_rq_fn *prep_rq_fn; 341 unplug_fn *unplug_fn; 342 merge_bvec_fn *merge_bvec_fn; 343 activity_fn *activity_fn; 344 issue_flush_fn *issue_flush_fn; 345 prepare_flush_fn *prepare_flush_fn; 346 softirq_done_fn *softirq_done_fn; 347 348 /* 349 * Dispatch queue sorting 350 */ 351 sector_t end_sector; 352 struct request *boundary_rq; 353 354 /* 355 * Auto-unplugging state 356 */ 357 struct timer_list unplug_timer; 358 int unplug_thresh; /* After this many requests */ 359 unsigned long unplug_delay; /* After this many jiffies */ 360 struct work_struct unplug_work; 361 362 struct backing_dev_info backing_dev_info; 363 364 /* 365 * The queue owner gets to use this for whatever they like. 366 * ll_rw_blk doesn't touch it. 367 */ 368 void *queuedata; 369 370 void *activity_data; 371 372 /* 373 * queue needs bounce pages for pages above this limit 374 */ 375 unsigned long bounce_pfn; 376 gfp_t bounce_gfp; 377 378 /* 379 * various queue flags, see QUEUE_* below 380 */ 381 unsigned long queue_flags; 382 383 /* 384 * protects queue structures from reentrancy. ->__queue_lock should 385 * _never_ be used directly, it is queue private. always use 386 * ->queue_lock. 387 */ 388 spinlock_t __queue_lock; 389 spinlock_t *queue_lock; 390 391 /* 392 * queue kobject 393 */ 394 struct kobject kobj; 395 396 /* 397 * queue settings 398 */ 399 unsigned long nr_requests; /* Max # of requests */ 400 unsigned int nr_congestion_on; 401 unsigned int nr_congestion_off; 402 unsigned int nr_batching; 403 404 unsigned int max_sectors; 405 unsigned int max_hw_sectors; 406 unsigned short max_phys_segments; 407 unsigned short max_hw_segments; 408 unsigned short hardsect_size; 409 unsigned int max_segment_size; 410 411 unsigned long seg_boundary_mask; 412 unsigned int dma_alignment; 413 414 struct blk_queue_tag *queue_tags; 415 416 unsigned int nr_sorted; 417 unsigned int in_flight; 418 419 /* 420 * sg stuff 421 */ 422 unsigned int sg_timeout; 423 unsigned int sg_reserved_size; 424 int node; 425 426 struct blk_trace *blk_trace; 427 428 /* 429 * reserved for flush operations 430 */ 431 unsigned int ordered, next_ordered, ordseq; 432 int orderr, ordcolor; 433 struct request pre_flush_rq, bar_rq, post_flush_rq; 434 struct request *orig_bar_rq; 435 unsigned int bi_size; 436 437 struct mutex sysfs_lock; 438 }; 439 440 #define RQ_INACTIVE (-1) 441 #define RQ_ACTIVE 1 442 #define RQ_SCSI_BUSY 0xffff 443 #define RQ_SCSI_DONE 0xfffe 444 #define RQ_SCSI_DISCONNECTING 0xffe0 445 446 #define QUEUE_FLAG_CLUSTER 0 /* cluster several segments into 1 */ 447 #define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */ 448 #define QUEUE_FLAG_STOPPED 2 /* queue is stopped */ 449 #define QUEUE_FLAG_READFULL 3 /* write queue has been filled */ 450 #define QUEUE_FLAG_WRITEFULL 4 /* read queue has been filled */ 451 #define QUEUE_FLAG_DEAD 5 /* queue being torn down */ 452 #define QUEUE_FLAG_REENTER 6 /* Re-entrancy avoidance */ 453 #define QUEUE_FLAG_PLUGGED 7 /* queue is plugged */ 454 #define QUEUE_FLAG_ELVSWITCH 8 /* don't use elevator, just do FIFO */ 455 456 enum { 457 /* 458 * Hardbarrier is supported with one of the following methods. 459 * 460 * NONE : hardbarrier unsupported 461 * DRAIN : ordering by draining is enough 462 * DRAIN_FLUSH : ordering by draining w/ pre and post flushes 463 * DRAIN_FUA : ordering by draining w/ pre flush and FUA write 464 * TAG : ordering by tag is enough 465 * TAG_FLUSH : ordering by tag w/ pre and post flushes 466 * TAG_FUA : ordering by tag w/ pre flush and FUA write 467 */ 468 QUEUE_ORDERED_NONE = 0x00, 469 QUEUE_ORDERED_DRAIN = 0x01, 470 QUEUE_ORDERED_TAG = 0x02, 471 472 QUEUE_ORDERED_PREFLUSH = 0x10, 473 QUEUE_ORDERED_POSTFLUSH = 0x20, 474 QUEUE_ORDERED_FUA = 0x40, 475 476 QUEUE_ORDERED_DRAIN_FLUSH = QUEUE_ORDERED_DRAIN | 477 QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_POSTFLUSH, 478 QUEUE_ORDERED_DRAIN_FUA = QUEUE_ORDERED_DRAIN | 479 QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_FUA, 480 QUEUE_ORDERED_TAG_FLUSH = QUEUE_ORDERED_TAG | 481 QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_POSTFLUSH, 482 QUEUE_ORDERED_TAG_FUA = QUEUE_ORDERED_TAG | 483 QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_FUA, 484 485 /* 486 * Ordered operation sequence 487 */ 488 QUEUE_ORDSEQ_STARTED = 0x01, /* flushing in progress */ 489 QUEUE_ORDSEQ_DRAIN = 0x02, /* waiting for the queue to be drained */ 490 QUEUE_ORDSEQ_PREFLUSH = 0x04, /* pre-flushing in progress */ 491 QUEUE_ORDSEQ_BAR = 0x08, /* original barrier req in progress */ 492 QUEUE_ORDSEQ_POSTFLUSH = 0x10, /* post-flushing in progress */ 493 QUEUE_ORDSEQ_DONE = 0x20, 494 }; 495 496 #define blk_queue_plugged(q) test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags) 497 #define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags) 498 #define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags) 499 #define blk_queue_flushing(q) ((q)->ordseq) 500 501 #define blk_fs_request(rq) ((rq)->flags & REQ_CMD) 502 #define blk_pc_request(rq) ((rq)->flags & REQ_BLOCK_PC) 503 #define blk_noretry_request(rq) ((rq)->flags & REQ_FAILFAST) 504 #define blk_rq_started(rq) ((rq)->flags & REQ_STARTED) 505 506 #define blk_account_rq(rq) (blk_rq_started(rq) && blk_fs_request(rq)) 507 508 #define blk_pm_suspend_request(rq) ((rq)->flags & REQ_PM_SUSPEND) 509 #define blk_pm_resume_request(rq) ((rq)->flags & REQ_PM_RESUME) 510 #define blk_pm_request(rq) \ 511 ((rq)->flags & (REQ_PM_SUSPEND | REQ_PM_RESUME)) 512 513 #define blk_sorted_rq(rq) ((rq)->flags & REQ_SORTED) 514 #define blk_barrier_rq(rq) ((rq)->flags & REQ_HARDBARRIER) 515 #define blk_fua_rq(rq) ((rq)->flags & REQ_FUA) 516 517 #define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist) 518 519 #define rq_data_dir(rq) ((rq)->flags & 1) 520 521 static inline int blk_queue_full(struct request_queue *q, int rw) 522 { 523 if (rw == READ) 524 return test_bit(QUEUE_FLAG_READFULL, &q->queue_flags); 525 return test_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags); 526 } 527 528 static inline void blk_set_queue_full(struct request_queue *q, int rw) 529 { 530 if (rw == READ) 531 set_bit(QUEUE_FLAG_READFULL, &q->queue_flags); 532 else 533 set_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags); 534 } 535 536 static inline void blk_clear_queue_full(struct request_queue *q, int rw) 537 { 538 if (rw == READ) 539 clear_bit(QUEUE_FLAG_READFULL, &q->queue_flags); 540 else 541 clear_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags); 542 } 543 544 545 /* 546 * mergeable request must not have _NOMERGE or _BARRIER bit set, nor may 547 * it already be started by driver. 548 */ 549 #define RQ_NOMERGE_FLAGS \ 550 (REQ_NOMERGE | REQ_STARTED | REQ_HARDBARRIER | REQ_SOFTBARRIER) 551 #define rq_mergeable(rq) \ 552 (!((rq)->flags & RQ_NOMERGE_FLAGS) && blk_fs_request((rq))) 553 554 /* 555 * noop, requests are automagically marked as active/inactive by I/O 556 * scheduler -- see elv_next_request 557 */ 558 #define blk_queue_headactive(q, head_active) 559 560 /* 561 * q->prep_rq_fn return values 562 */ 563 #define BLKPREP_OK 0 /* serve it */ 564 #define BLKPREP_KILL 1 /* fatal error, kill */ 565 #define BLKPREP_DEFER 2 /* leave on queue */ 566 567 extern unsigned long blk_max_low_pfn, blk_max_pfn; 568 569 /* 570 * standard bounce addresses: 571 * 572 * BLK_BOUNCE_HIGH : bounce all highmem pages 573 * BLK_BOUNCE_ANY : don't bounce anything 574 * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary 575 */ 576 #define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT) 577 #define BLK_BOUNCE_ANY ((u64)blk_max_pfn << PAGE_SHIFT) 578 #define BLK_BOUNCE_ISA (ISA_DMA_THRESHOLD) 579 580 #ifdef CONFIG_MMU 581 extern int init_emergency_isa_pool(void); 582 extern void blk_queue_bounce(request_queue_t *q, struct bio **bio); 583 #else 584 static inline int init_emergency_isa_pool(void) 585 { 586 return 0; 587 } 588 static inline void blk_queue_bounce(request_queue_t *q, struct bio **bio) 589 { 590 } 591 #endif /* CONFIG_MMU */ 592 593 #define rq_for_each_bio(_bio, rq) \ 594 if ((rq->bio)) \ 595 for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next) 596 597 struct sec_size { 598 unsigned block_size; 599 unsigned block_size_bits; 600 }; 601 602 extern int blk_register_queue(struct gendisk *disk); 603 extern void blk_unregister_queue(struct gendisk *disk); 604 extern void register_disk(struct gendisk *dev); 605 extern void generic_make_request(struct bio *bio); 606 extern void blk_put_request(struct request *); 607 extern void __blk_put_request(request_queue_t *, struct request *); 608 extern void blk_end_sync_rq(struct request *rq, int error); 609 extern struct request *blk_get_request(request_queue_t *, int, gfp_t); 610 extern void blk_insert_request(request_queue_t *, struct request *, int, void *); 611 extern void blk_requeue_request(request_queue_t *, struct request *); 612 extern void blk_plug_device(request_queue_t *); 613 extern int blk_remove_plug(request_queue_t *); 614 extern void blk_recount_segments(request_queue_t *, struct bio *); 615 extern int scsi_cmd_ioctl(struct file *, struct gendisk *, unsigned int, void __user *); 616 extern int sg_scsi_ioctl(struct file *, struct request_queue *, 617 struct gendisk *, struct scsi_ioctl_command __user *); 618 extern void blk_start_queue(request_queue_t *q); 619 extern void blk_stop_queue(request_queue_t *q); 620 extern void blk_sync_queue(struct request_queue *q); 621 extern void __blk_stop_queue(request_queue_t *q); 622 extern void blk_run_queue(request_queue_t *); 623 extern void blk_queue_activity_fn(request_queue_t *, activity_fn *, void *); 624 extern int blk_rq_map_user(request_queue_t *, struct request *, void __user *, unsigned int); 625 extern int blk_rq_unmap_user(struct bio *, unsigned int); 626 extern int blk_rq_map_kern(request_queue_t *, struct request *, void *, unsigned int, gfp_t); 627 extern int blk_rq_map_user_iov(request_queue_t *, struct request *, struct sg_iovec *, int); 628 extern int blk_execute_rq(request_queue_t *, struct gendisk *, 629 struct request *, int); 630 extern void blk_execute_rq_nowait(request_queue_t *, struct gendisk *, 631 struct request *, int, rq_end_io_fn *); 632 633 static inline request_queue_t *bdev_get_queue(struct block_device *bdev) 634 { 635 return bdev->bd_disk->queue; 636 } 637 638 static inline void blk_run_backing_dev(struct backing_dev_info *bdi, 639 struct page *page) 640 { 641 if (bdi && bdi->unplug_io_fn) 642 bdi->unplug_io_fn(bdi, page); 643 } 644 645 static inline void blk_run_address_space(struct address_space *mapping) 646 { 647 if (mapping) 648 blk_run_backing_dev(mapping->backing_dev_info, NULL); 649 } 650 651 /* 652 * end_request() and friends. Must be called with the request queue spinlock 653 * acquired. All functions called within end_request() _must_be_ atomic. 654 * 655 * Several drivers define their own end_request and call 656 * end_that_request_first() and end_that_request_last() 657 * for parts of the original function. This prevents 658 * code duplication in drivers. 659 */ 660 extern int end_that_request_first(struct request *, int, int); 661 extern int end_that_request_chunk(struct request *, int, int); 662 extern void end_that_request_last(struct request *, int); 663 extern void end_request(struct request *req, int uptodate); 664 extern void blk_complete_request(struct request *); 665 666 static inline int rq_all_done(struct request *rq, unsigned int nr_bytes) 667 { 668 if (blk_fs_request(rq)) 669 return (nr_bytes >= (rq->hard_nr_sectors << 9)); 670 else if (blk_pc_request(rq)) 671 return nr_bytes >= rq->data_len; 672 673 return 0; 674 } 675 676 /* 677 * end_that_request_first/chunk() takes an uptodate argument. we account 678 * any value <= as an io error. 0 means -EIO for compatability reasons, 679 * any other < 0 value is the direct error type. An uptodate value of 680 * 1 indicates successful io completion 681 */ 682 #define end_io_error(uptodate) (unlikely((uptodate) <= 0)) 683 684 static inline void blkdev_dequeue_request(struct request *req) 685 { 686 elv_dequeue_request(req->q, req); 687 } 688 689 /* 690 * This should be in elevator.h, but that requires pulling in rq and q 691 */ 692 static inline void elv_dispatch_add_tail(struct request_queue *q, 693 struct request *rq) 694 { 695 if (q->last_merge == rq) 696 q->last_merge = NULL; 697 q->nr_sorted--; 698 699 q->end_sector = rq_end_sector(rq); 700 q->boundary_rq = rq; 701 list_add_tail(&rq->queuelist, &q->queue_head); 702 } 703 704 /* 705 * Access functions for manipulating queue properties 706 */ 707 extern request_queue_t *blk_init_queue_node(request_fn_proc *rfn, 708 spinlock_t *lock, int node_id); 709 extern request_queue_t *blk_init_queue(request_fn_proc *, spinlock_t *); 710 extern void blk_cleanup_queue(request_queue_t *); 711 extern void blk_queue_make_request(request_queue_t *, make_request_fn *); 712 extern void blk_queue_bounce_limit(request_queue_t *, u64); 713 extern void blk_queue_max_sectors(request_queue_t *, unsigned int); 714 extern void blk_queue_max_phys_segments(request_queue_t *, unsigned short); 715 extern void blk_queue_max_hw_segments(request_queue_t *, unsigned short); 716 extern void blk_queue_max_segment_size(request_queue_t *, unsigned int); 717 extern void blk_queue_hardsect_size(request_queue_t *, unsigned short); 718 extern void blk_queue_stack_limits(request_queue_t *t, request_queue_t *b); 719 extern void blk_queue_segment_boundary(request_queue_t *, unsigned long); 720 extern void blk_queue_prep_rq(request_queue_t *, prep_rq_fn *pfn); 721 extern void blk_queue_merge_bvec(request_queue_t *, merge_bvec_fn *); 722 extern void blk_queue_dma_alignment(request_queue_t *, int); 723 extern void blk_queue_softirq_done(request_queue_t *, softirq_done_fn *); 724 extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev); 725 extern int blk_queue_ordered(request_queue_t *, unsigned, prepare_flush_fn *); 726 extern void blk_queue_issue_flush_fn(request_queue_t *, issue_flush_fn *); 727 extern int blk_do_ordered(request_queue_t *, struct request **); 728 extern unsigned blk_ordered_cur_seq(request_queue_t *); 729 extern unsigned blk_ordered_req_seq(struct request *); 730 extern void blk_ordered_complete_seq(request_queue_t *, unsigned, int); 731 732 extern int blk_rq_map_sg(request_queue_t *, struct request *, struct scatterlist *); 733 extern void blk_dump_rq_flags(struct request *, char *); 734 extern void generic_unplug_device(request_queue_t *); 735 extern void __generic_unplug_device(request_queue_t *); 736 extern long nr_blockdev_pages(void); 737 738 int blk_get_queue(request_queue_t *); 739 request_queue_t *blk_alloc_queue(gfp_t); 740 request_queue_t *blk_alloc_queue_node(gfp_t, int); 741 extern void blk_put_queue(request_queue_t *); 742 743 /* 744 * tag stuff 745 */ 746 #define blk_queue_tag_depth(q) ((q)->queue_tags->busy) 747 #define blk_queue_tag_queue(q) ((q)->queue_tags->busy < (q)->queue_tags->max_depth) 748 #define blk_rq_tagged(rq) ((rq)->flags & REQ_QUEUED) 749 extern int blk_queue_start_tag(request_queue_t *, struct request *); 750 extern struct request *blk_queue_find_tag(request_queue_t *, int); 751 extern void blk_queue_end_tag(request_queue_t *, struct request *); 752 extern int blk_queue_init_tags(request_queue_t *, int, struct blk_queue_tag *); 753 extern void blk_queue_free_tags(request_queue_t *); 754 extern int blk_queue_resize_tags(request_queue_t *, int); 755 extern void blk_queue_invalidate_tags(request_queue_t *); 756 extern long blk_congestion_wait(int rw, long timeout); 757 758 extern void blk_rq_bio_prep(request_queue_t *, struct request *, struct bio *); 759 extern int blkdev_issue_flush(struct block_device *, sector_t *); 760 761 #define MAX_PHYS_SEGMENTS 128 762 #define MAX_HW_SEGMENTS 128 763 #define SAFE_MAX_SECTORS 255 764 #define BLK_DEF_MAX_SECTORS 1024 765 766 #define MAX_SEGMENT_SIZE 65536 767 768 #define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist) 769 770 static inline int queue_hardsect_size(request_queue_t *q) 771 { 772 int retval = 512; 773 774 if (q && q->hardsect_size) 775 retval = q->hardsect_size; 776 777 return retval; 778 } 779 780 static inline int bdev_hardsect_size(struct block_device *bdev) 781 { 782 return queue_hardsect_size(bdev_get_queue(bdev)); 783 } 784 785 static inline int queue_dma_alignment(request_queue_t *q) 786 { 787 int retval = 511; 788 789 if (q && q->dma_alignment) 790 retval = q->dma_alignment; 791 792 return retval; 793 } 794 795 static inline int bdev_dma_aligment(struct block_device *bdev) 796 { 797 return queue_dma_alignment(bdev_get_queue(bdev)); 798 } 799 800 #define blk_finished_io(nsects) do { } while (0) 801 #define blk_started_io(nsects) do { } while (0) 802 803 /* assumes size > 256 */ 804 static inline unsigned int blksize_bits(unsigned int size) 805 { 806 unsigned int bits = 8; 807 do { 808 bits++; 809 size >>= 1; 810 } while (size > 256); 811 return bits; 812 } 813 814 static inline unsigned int block_size(struct block_device *bdev) 815 { 816 return bdev->bd_block_size; 817 } 818 819 typedef struct {struct page *v;} Sector; 820 821 unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *); 822 823 static inline void put_dev_sector(Sector p) 824 { 825 page_cache_release(p.v); 826 } 827 828 struct work_struct; 829 int kblockd_schedule_work(struct work_struct *work); 830 void kblockd_flush(void); 831 832 #ifdef CONFIG_LBD 833 # include <asm/div64.h> 834 # define sector_div(a, b) do_div(a, b) 835 #else 836 # define sector_div(n, b)( \ 837 { \ 838 int _res; \ 839 _res = (n) % (b); \ 840 (n) /= (b); \ 841 _res; \ 842 } \ 843 ) 844 #endif 845 846 #define MODULE_ALIAS_BLOCKDEV(major,minor) \ 847 MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor)) 848 #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \ 849 MODULE_ALIAS("block-major-" __stringify(major) "-*") 850 851 852 #endif 853