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