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