1 #ifndef _LINUX_BLKDEV_H 2 #define _LINUX_BLKDEV_H 3 4 #ifdef CONFIG_BLOCK 5 6 #include <linux/sched.h> 7 #include <linux/major.h> 8 #include <linux/genhd.h> 9 #include <linux/list.h> 10 #include <linux/timer.h> 11 #include <linux/workqueue.h> 12 #include <linux/pagemap.h> 13 #include <linux/backing-dev.h> 14 #include <linux/wait.h> 15 #include <linux/mempool.h> 16 #include <linux/bio.h> 17 #include <linux/module.h> 18 #include <linux/stringify.h> 19 #include <linux/bsg.h> 20 21 #include <asm/scatterlist.h> 22 23 struct scsi_ioctl_command; 24 25 struct request_queue; 26 typedef struct request_queue request_queue_t __deprecated; 27 struct elevator_queue; 28 typedef struct elevator_queue elevator_t; 29 struct request_pm_state; 30 struct blk_trace; 31 struct request; 32 struct sg_io_hdr; 33 34 #define BLKDEV_MIN_RQ 4 35 #define BLKDEV_MAX_RQ 128 /* Default maximum */ 36 37 /* 38 * This is the per-process anticipatory I/O scheduler state. 39 */ 40 struct as_io_context { 41 spinlock_t lock; 42 43 void (*dtor)(struct as_io_context *aic); /* destructor */ 44 void (*exit)(struct as_io_context *aic); /* called on task exit */ 45 46 unsigned long state; 47 atomic_t nr_queued; /* queued reads & sync writes */ 48 atomic_t nr_dispatched; /* number of requests gone to the drivers */ 49 50 /* IO History tracking */ 51 /* Thinktime */ 52 unsigned long last_end_request; 53 unsigned long ttime_total; 54 unsigned long ttime_samples; 55 unsigned long ttime_mean; 56 /* Layout pattern */ 57 unsigned int seek_samples; 58 sector_t last_request_pos; 59 u64 seek_total; 60 sector_t seek_mean; 61 }; 62 63 struct cfq_queue; 64 struct cfq_io_context { 65 struct rb_node rb_node; 66 void *key; 67 68 struct cfq_queue *cfqq[2]; 69 70 struct io_context *ioc; 71 72 unsigned long last_end_request; 73 sector_t last_request_pos; 74 75 unsigned long ttime_total; 76 unsigned long ttime_samples; 77 unsigned long ttime_mean; 78 79 unsigned int seek_samples; 80 u64 seek_total; 81 sector_t seek_mean; 82 83 struct list_head queue_list; 84 85 void (*dtor)(struct io_context *); /* destructor */ 86 void (*exit)(struct io_context *); /* called on task exit */ 87 }; 88 89 /* 90 * This is the per-process I/O subsystem state. It is refcounted and 91 * kmalloc'ed. Currently all fields are modified in process io context 92 * (apart from the atomic refcount), so require no locking. 93 */ 94 struct io_context { 95 atomic_t refcount; 96 struct task_struct *task; 97 98 unsigned int ioprio_changed; 99 100 /* 101 * For request batching 102 */ 103 unsigned long last_waited; /* Time last woken after wait for request */ 104 int nr_batch_requests; /* Number of requests left in the batch */ 105 106 struct as_io_context *aic; 107 struct rb_root cic_root; 108 void *ioc_data; 109 }; 110 111 void put_io_context(struct io_context *ioc); 112 void exit_io_context(void); 113 struct io_context *get_io_context(gfp_t gfp_flags, int node); 114 void copy_io_context(struct io_context **pdst, struct io_context **psrc); 115 void swap_io_context(struct io_context **ioc1, struct io_context **ioc2); 116 117 struct request; 118 typedef void (rq_end_io_fn)(struct request *, int); 119 120 struct request_list { 121 int count[2]; 122 int starved[2]; 123 int elvpriv; 124 mempool_t *rq_pool; 125 wait_queue_head_t wait[2]; 126 }; 127 128 /* 129 * request command types 130 */ 131 enum rq_cmd_type_bits { 132 REQ_TYPE_FS = 1, /* fs request */ 133 REQ_TYPE_BLOCK_PC, /* scsi command */ 134 REQ_TYPE_SENSE, /* sense request */ 135 REQ_TYPE_PM_SUSPEND, /* suspend request */ 136 REQ_TYPE_PM_RESUME, /* resume request */ 137 REQ_TYPE_PM_SHUTDOWN, /* shutdown request */ 138 REQ_TYPE_FLUSH, /* flush request */ 139 REQ_TYPE_SPECIAL, /* driver defined type */ 140 REQ_TYPE_LINUX_BLOCK, /* generic block layer message */ 141 /* 142 * for ATA/ATAPI devices. this really doesn't belong here, ide should 143 * use REQ_TYPE_SPECIAL and use rq->cmd[0] with the range of driver 144 * private REQ_LB opcodes to differentiate what type of request this is 145 */ 146 REQ_TYPE_ATA_CMD, 147 REQ_TYPE_ATA_TASK, 148 REQ_TYPE_ATA_TASKFILE, 149 REQ_TYPE_ATA_PC, 150 }; 151 152 /* 153 * For request of type REQ_TYPE_LINUX_BLOCK, rq->cmd[0] is the opcode being 154 * sent down (similar to how REQ_TYPE_BLOCK_PC means that ->cmd[] holds a 155 * SCSI cdb. 156 * 157 * 0x00 -> 0x3f are driver private, to be used for whatever purpose they need, 158 * typically to differentiate REQ_TYPE_SPECIAL requests. 159 * 160 */ 161 enum { 162 /* 163 * just examples for now 164 */ 165 REQ_LB_OP_EJECT = 0x40, /* eject request */ 166 REQ_LB_OP_FLUSH = 0x41, /* flush device */ 167 }; 168 169 /* 170 * request type modified bits. first three bits match BIO_RW* bits, important 171 */ 172 enum rq_flag_bits { 173 __REQ_RW, /* not set, read. set, write */ 174 __REQ_FAILFAST, /* no low level driver retries */ 175 __REQ_SORTED, /* elevator knows about this request */ 176 __REQ_SOFTBARRIER, /* may not be passed by ioscheduler */ 177 __REQ_HARDBARRIER, /* may not be passed by drive either */ 178 __REQ_FUA, /* forced unit access */ 179 __REQ_NOMERGE, /* don't touch this for merging */ 180 __REQ_STARTED, /* drive already may have started this one */ 181 __REQ_DONTPREP, /* don't call prep for this one */ 182 __REQ_QUEUED, /* uses queueing */ 183 __REQ_ELVPRIV, /* elevator private data attached */ 184 __REQ_FAILED, /* set if the request failed */ 185 __REQ_QUIET, /* don't worry about errors */ 186 __REQ_PREEMPT, /* set for "ide_preempt" requests */ 187 __REQ_ORDERED_COLOR, /* is before or after barrier */ 188 __REQ_RW_SYNC, /* request is sync (O_DIRECT) */ 189 __REQ_ALLOCED, /* request came from our alloc pool */ 190 __REQ_RW_META, /* metadata io request */ 191 __REQ_NR_BITS, /* stops here */ 192 }; 193 194 #define REQ_RW (1 << __REQ_RW) 195 #define REQ_FAILFAST (1 << __REQ_FAILFAST) 196 #define REQ_SORTED (1 << __REQ_SORTED) 197 #define REQ_SOFTBARRIER (1 << __REQ_SOFTBARRIER) 198 #define REQ_HARDBARRIER (1 << __REQ_HARDBARRIER) 199 #define REQ_FUA (1 << __REQ_FUA) 200 #define REQ_NOMERGE (1 << __REQ_NOMERGE) 201 #define REQ_STARTED (1 << __REQ_STARTED) 202 #define REQ_DONTPREP (1 << __REQ_DONTPREP) 203 #define REQ_QUEUED (1 << __REQ_QUEUED) 204 #define REQ_ELVPRIV (1 << __REQ_ELVPRIV) 205 #define REQ_FAILED (1 << __REQ_FAILED) 206 #define REQ_QUIET (1 << __REQ_QUIET) 207 #define REQ_PREEMPT (1 << __REQ_PREEMPT) 208 #define REQ_ORDERED_COLOR (1 << __REQ_ORDERED_COLOR) 209 #define REQ_RW_SYNC (1 << __REQ_RW_SYNC) 210 #define REQ_ALLOCED (1 << __REQ_ALLOCED) 211 #define REQ_RW_META (1 << __REQ_RW_META) 212 213 #define BLK_MAX_CDB 16 214 215 /* 216 * try to put the fields that are referenced together in the same cacheline 217 */ 218 struct request { 219 struct list_head queuelist; 220 struct list_head donelist; 221 222 struct request_queue *q; 223 224 unsigned int cmd_flags; 225 enum rq_cmd_type_bits cmd_type; 226 227 /* Maintain bio traversal state for part by part I/O submission. 228 * hard_* are block layer internals, no driver should touch them! 229 */ 230 231 sector_t sector; /* next sector to submit */ 232 sector_t hard_sector; /* next sector to complete */ 233 unsigned long nr_sectors; /* no. of sectors left to submit */ 234 unsigned long hard_nr_sectors; /* no. of sectors left to complete */ 235 /* no. of sectors left to submit in the current segment */ 236 unsigned int current_nr_sectors; 237 238 /* no. of sectors left to complete in the current segment */ 239 unsigned int hard_cur_sectors; 240 241 struct bio *bio; 242 struct bio *biotail; 243 244 struct hlist_node hash; /* merge hash */ 245 /* 246 * The rb_node is only used inside the io scheduler, requests 247 * are pruned when moved to the dispatch queue. So let the 248 * completion_data share space with the rb_node. 249 */ 250 union { 251 struct rb_node rb_node; /* sort/lookup */ 252 void *completion_data; 253 }; 254 255 /* 256 * two pointers are available for the IO schedulers, if they need 257 * more they have to dynamically allocate it. 258 */ 259 void *elevator_private; 260 void *elevator_private2; 261 262 struct gendisk *rq_disk; 263 unsigned long start_time; 264 265 /* Number of scatter-gather DMA addr+len pairs after 266 * physical address coalescing is performed. 267 */ 268 unsigned short nr_phys_segments; 269 270 /* Number of scatter-gather addr+len pairs after 271 * physical and DMA remapping hardware coalescing is performed. 272 * This is the number of scatter-gather entries the driver 273 * will actually have to deal with after DMA mapping is done. 274 */ 275 unsigned short nr_hw_segments; 276 277 unsigned short ioprio; 278 279 void *special; 280 char *buffer; 281 282 int tag; 283 int errors; 284 285 int ref_count; 286 287 /* 288 * when request is used as a packet command carrier 289 */ 290 unsigned int cmd_len; 291 unsigned char cmd[BLK_MAX_CDB]; 292 293 unsigned int data_len; 294 unsigned int sense_len; 295 void *data; 296 void *sense; 297 298 unsigned int timeout; 299 int retries; 300 301 /* 302 * completion callback. 303 */ 304 rq_end_io_fn *end_io; 305 void *end_io_data; 306 307 /* for bidi */ 308 struct request *next_rq; 309 }; 310 311 /* 312 * State information carried for REQ_TYPE_PM_SUSPEND and REQ_TYPE_PM_RESUME 313 * requests. Some step values could eventually be made generic. 314 */ 315 struct request_pm_state 316 { 317 /* PM state machine step value, currently driver specific */ 318 int pm_step; 319 /* requested PM state value (S1, S2, S3, S4, ...) */ 320 u32 pm_state; 321 void* data; /* for driver use */ 322 }; 323 324 #include <linux/elevator.h> 325 326 typedef void (request_fn_proc) (struct request_queue *q); 327 typedef int (make_request_fn) (struct request_queue *q, struct bio *bio); 328 typedef int (prep_rq_fn) (struct request_queue *, struct request *); 329 typedef void (unplug_fn) (struct request_queue *); 330 331 struct bio_vec; 332 typedef int (merge_bvec_fn) (struct request_queue *, struct bio *, struct bio_vec *); 333 typedef void (prepare_flush_fn) (struct request_queue *, struct request *); 334 typedef void (softirq_done_fn)(struct request *); 335 336 enum blk_queue_state { 337 Queue_down, 338 Queue_up, 339 }; 340 341 struct blk_queue_tag { 342 struct request **tag_index; /* map of busy tags */ 343 unsigned long *tag_map; /* bit map of free/busy tags */ 344 struct list_head busy_list; /* fifo list of busy tags */ 345 int busy; /* current depth */ 346 int max_depth; /* what we will send to device */ 347 int real_max_depth; /* what the array can hold */ 348 atomic_t refcnt; /* map can be shared */ 349 }; 350 351 struct request_queue 352 { 353 /* 354 * Together with queue_head for cacheline sharing 355 */ 356 struct list_head queue_head; 357 struct request *last_merge; 358 elevator_t *elevator; 359 360 /* 361 * the queue request freelist, one for reads and one for writes 362 */ 363 struct request_list rq; 364 365 request_fn_proc *request_fn; 366 make_request_fn *make_request_fn; 367 prep_rq_fn *prep_rq_fn; 368 unplug_fn *unplug_fn; 369 merge_bvec_fn *merge_bvec_fn; 370 prepare_flush_fn *prepare_flush_fn; 371 softirq_done_fn *softirq_done_fn; 372 373 /* 374 * Dispatch queue sorting 375 */ 376 sector_t end_sector; 377 struct request *boundary_rq; 378 379 /* 380 * Auto-unplugging state 381 */ 382 struct timer_list unplug_timer; 383 int unplug_thresh; /* After this many requests */ 384 unsigned long unplug_delay; /* After this many jiffies */ 385 struct work_struct unplug_work; 386 387 struct backing_dev_info backing_dev_info; 388 389 /* 390 * The queue owner gets to use this for whatever they like. 391 * ll_rw_blk doesn't touch it. 392 */ 393 void *queuedata; 394 395 /* 396 * queue needs bounce pages for pages above this limit 397 */ 398 unsigned long bounce_pfn; 399 gfp_t bounce_gfp; 400 401 /* 402 * various queue flags, see QUEUE_* below 403 */ 404 unsigned long queue_flags; 405 406 /* 407 * protects queue structures from reentrancy. ->__queue_lock should 408 * _never_ be used directly, it is queue private. always use 409 * ->queue_lock. 410 */ 411 spinlock_t __queue_lock; 412 spinlock_t *queue_lock; 413 414 /* 415 * queue kobject 416 */ 417 struct kobject kobj; 418 419 /* 420 * queue settings 421 */ 422 unsigned long nr_requests; /* Max # of requests */ 423 unsigned int nr_congestion_on; 424 unsigned int nr_congestion_off; 425 unsigned int nr_batching; 426 427 unsigned int max_sectors; 428 unsigned int max_hw_sectors; 429 unsigned short max_phys_segments; 430 unsigned short max_hw_segments; 431 unsigned short hardsect_size; 432 unsigned int max_segment_size; 433 434 unsigned long seg_boundary_mask; 435 unsigned int dma_alignment; 436 437 struct blk_queue_tag *queue_tags; 438 439 unsigned int nr_sorted; 440 unsigned int in_flight; 441 442 /* 443 * sg stuff 444 */ 445 unsigned int sg_timeout; 446 unsigned int sg_reserved_size; 447 int node; 448 #ifdef CONFIG_BLK_DEV_IO_TRACE 449 struct blk_trace *blk_trace; 450 #endif 451 /* 452 * reserved for flush operations 453 */ 454 unsigned int ordered, next_ordered, ordseq; 455 int orderr, ordcolor; 456 struct request pre_flush_rq, bar_rq, post_flush_rq; 457 struct request *orig_bar_rq; 458 459 struct mutex sysfs_lock; 460 461 #if defined(CONFIG_BLK_DEV_BSG) 462 struct bsg_class_device bsg_dev; 463 #endif 464 }; 465 466 #define QUEUE_FLAG_CLUSTER 0 /* cluster several segments into 1 */ 467 #define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */ 468 #define QUEUE_FLAG_STOPPED 2 /* queue is stopped */ 469 #define QUEUE_FLAG_READFULL 3 /* read queue has been filled */ 470 #define QUEUE_FLAG_WRITEFULL 4 /* write queue has been filled */ 471 #define QUEUE_FLAG_DEAD 5 /* queue being torn down */ 472 #define QUEUE_FLAG_REENTER 6 /* Re-entrancy avoidance */ 473 #define QUEUE_FLAG_PLUGGED 7 /* queue is plugged */ 474 #define QUEUE_FLAG_ELVSWITCH 8 /* don't use elevator, just do FIFO */ 475 #define QUEUE_FLAG_BIDI 9 /* queue supports bidi requests */ 476 477 enum { 478 /* 479 * Hardbarrier is supported with one of the following methods. 480 * 481 * NONE : hardbarrier unsupported 482 * DRAIN : ordering by draining is enough 483 * DRAIN_FLUSH : ordering by draining w/ pre and post flushes 484 * DRAIN_FUA : ordering by draining w/ pre flush and FUA write 485 * TAG : ordering by tag is enough 486 * TAG_FLUSH : ordering by tag w/ pre and post flushes 487 * TAG_FUA : ordering by tag w/ pre flush and FUA write 488 */ 489 QUEUE_ORDERED_NONE = 0x00, 490 QUEUE_ORDERED_DRAIN = 0x01, 491 QUEUE_ORDERED_TAG = 0x02, 492 493 QUEUE_ORDERED_PREFLUSH = 0x10, 494 QUEUE_ORDERED_POSTFLUSH = 0x20, 495 QUEUE_ORDERED_FUA = 0x40, 496 497 QUEUE_ORDERED_DRAIN_FLUSH = QUEUE_ORDERED_DRAIN | 498 QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_POSTFLUSH, 499 QUEUE_ORDERED_DRAIN_FUA = QUEUE_ORDERED_DRAIN | 500 QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_FUA, 501 QUEUE_ORDERED_TAG_FLUSH = QUEUE_ORDERED_TAG | 502 QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_POSTFLUSH, 503 QUEUE_ORDERED_TAG_FUA = QUEUE_ORDERED_TAG | 504 QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_FUA, 505 506 /* 507 * Ordered operation sequence 508 */ 509 QUEUE_ORDSEQ_STARTED = 0x01, /* flushing in progress */ 510 QUEUE_ORDSEQ_DRAIN = 0x02, /* waiting for the queue to be drained */ 511 QUEUE_ORDSEQ_PREFLUSH = 0x04, /* pre-flushing in progress */ 512 QUEUE_ORDSEQ_BAR = 0x08, /* original barrier req in progress */ 513 QUEUE_ORDSEQ_POSTFLUSH = 0x10, /* post-flushing in progress */ 514 QUEUE_ORDSEQ_DONE = 0x20, 515 }; 516 517 #define blk_queue_plugged(q) test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags) 518 #define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags) 519 #define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags) 520 #define blk_queue_flushing(q) ((q)->ordseq) 521 522 #define blk_fs_request(rq) ((rq)->cmd_type == REQ_TYPE_FS) 523 #define blk_pc_request(rq) ((rq)->cmd_type == REQ_TYPE_BLOCK_PC) 524 #define blk_special_request(rq) ((rq)->cmd_type == REQ_TYPE_SPECIAL) 525 #define blk_sense_request(rq) ((rq)->cmd_type == REQ_TYPE_SENSE) 526 527 #define blk_noretry_request(rq) ((rq)->cmd_flags & REQ_FAILFAST) 528 #define blk_rq_started(rq) ((rq)->cmd_flags & REQ_STARTED) 529 530 #define blk_account_rq(rq) (blk_rq_started(rq) && blk_fs_request(rq)) 531 532 #define blk_pm_suspend_request(rq) ((rq)->cmd_type == REQ_TYPE_PM_SUSPEND) 533 #define blk_pm_resume_request(rq) ((rq)->cmd_type == REQ_TYPE_PM_RESUME) 534 #define blk_pm_request(rq) \ 535 (blk_pm_suspend_request(rq) || blk_pm_resume_request(rq)) 536 537 #define blk_sorted_rq(rq) ((rq)->cmd_flags & REQ_SORTED) 538 #define blk_barrier_rq(rq) ((rq)->cmd_flags & REQ_HARDBARRIER) 539 #define blk_fua_rq(rq) ((rq)->cmd_flags & REQ_FUA) 540 #define blk_bidi_rq(rq) ((rq)->next_rq != NULL) 541 #define blk_empty_barrier(rq) (blk_barrier_rq(rq) && blk_fs_request(rq) && !(rq)->hard_nr_sectors) 542 543 #define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist) 544 545 #define rq_data_dir(rq) ((rq)->cmd_flags & 1) 546 547 /* 548 * We regard a request as sync, if it's a READ or a SYNC write. 549 */ 550 #define rq_is_sync(rq) (rq_data_dir((rq)) == READ || (rq)->cmd_flags & REQ_RW_SYNC) 551 #define rq_is_meta(rq) ((rq)->cmd_flags & REQ_RW_META) 552 553 static inline int blk_queue_full(struct request_queue *q, int rw) 554 { 555 if (rw == READ) 556 return test_bit(QUEUE_FLAG_READFULL, &q->queue_flags); 557 return test_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags); 558 } 559 560 static inline void blk_set_queue_full(struct request_queue *q, int rw) 561 { 562 if (rw == READ) 563 set_bit(QUEUE_FLAG_READFULL, &q->queue_flags); 564 else 565 set_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags); 566 } 567 568 static inline void blk_clear_queue_full(struct request_queue *q, int rw) 569 { 570 if (rw == READ) 571 clear_bit(QUEUE_FLAG_READFULL, &q->queue_flags); 572 else 573 clear_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags); 574 } 575 576 577 /* 578 * mergeable request must not have _NOMERGE or _BARRIER bit set, nor may 579 * it already be started by driver. 580 */ 581 #define RQ_NOMERGE_FLAGS \ 582 (REQ_NOMERGE | REQ_STARTED | REQ_HARDBARRIER | REQ_SOFTBARRIER) 583 #define rq_mergeable(rq) \ 584 (!((rq)->cmd_flags & RQ_NOMERGE_FLAGS) && blk_fs_request((rq))) 585 586 /* 587 * q->prep_rq_fn return values 588 */ 589 #define BLKPREP_OK 0 /* serve it */ 590 #define BLKPREP_KILL 1 /* fatal error, kill */ 591 #define BLKPREP_DEFER 2 /* leave on queue */ 592 593 extern unsigned long blk_max_low_pfn, blk_max_pfn; 594 595 /* 596 * standard bounce addresses: 597 * 598 * BLK_BOUNCE_HIGH : bounce all highmem pages 599 * BLK_BOUNCE_ANY : don't bounce anything 600 * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary 601 */ 602 #define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT) 603 #define BLK_BOUNCE_ANY ((u64)blk_max_pfn << PAGE_SHIFT) 604 #define BLK_BOUNCE_ISA (ISA_DMA_THRESHOLD) 605 606 /* 607 * default timeout for SG_IO if none specified 608 */ 609 #define BLK_DEFAULT_SG_TIMEOUT (60 * HZ) 610 611 #ifdef CONFIG_BOUNCE 612 extern int init_emergency_isa_pool(void); 613 extern void blk_queue_bounce(struct request_queue *q, struct bio **bio); 614 #else 615 static inline int init_emergency_isa_pool(void) 616 { 617 return 0; 618 } 619 static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio) 620 { 621 } 622 #endif /* CONFIG_MMU */ 623 624 struct req_iterator { 625 int i; 626 struct bio *bio; 627 }; 628 629 /* This should not be used directly - use rq_for_each_segment */ 630 #define __rq_for_each_bio(_bio, rq) \ 631 if ((rq->bio)) \ 632 for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next) 633 634 #define rq_for_each_segment(bvl, _rq, _iter) \ 635 __rq_for_each_bio(_iter.bio, _rq) \ 636 bio_for_each_segment(bvl, _iter.bio, _iter.i) 637 638 #define rq_iter_last(rq, _iter) \ 639 (_iter.bio->bi_next == NULL && _iter.i == _iter.bio->bi_vcnt-1) 640 641 extern int blk_register_queue(struct gendisk *disk); 642 extern void blk_unregister_queue(struct gendisk *disk); 643 extern void register_disk(struct gendisk *dev); 644 extern void generic_make_request(struct bio *bio); 645 extern void blk_put_request(struct request *); 646 extern void __blk_put_request(struct request_queue *, struct request *); 647 extern void blk_end_sync_rq(struct request *rq, int error); 648 extern struct request *blk_get_request(struct request_queue *, int, gfp_t); 649 extern void blk_insert_request(struct request_queue *, struct request *, int, void *); 650 extern void blk_requeue_request(struct request_queue *, struct request *); 651 extern void blk_plug_device(struct request_queue *); 652 extern int blk_remove_plug(struct request_queue *); 653 extern void blk_recount_segments(struct request_queue *, struct bio *); 654 extern int scsi_cmd_ioctl(struct file *, struct request_queue *, 655 struct gendisk *, unsigned int, void __user *); 656 extern int sg_scsi_ioctl(struct file *, struct request_queue *, 657 struct gendisk *, struct scsi_ioctl_command __user *); 658 659 /* 660 * Temporary export, until SCSI gets fixed up. 661 */ 662 extern int blk_rq_append_bio(struct request_queue *q, struct request *rq, 663 struct bio *bio); 664 665 /* 666 * A queue has just exitted congestion. Note this in the global counter of 667 * congested queues, and wake up anyone who was waiting for requests to be 668 * put back. 669 */ 670 static inline void blk_clear_queue_congested(struct request_queue *q, int rw) 671 { 672 clear_bdi_congested(&q->backing_dev_info, rw); 673 } 674 675 /* 676 * A queue has just entered congestion. Flag that in the queue's VM-visible 677 * state flags and increment the global gounter of congested queues. 678 */ 679 static inline void blk_set_queue_congested(struct request_queue *q, int rw) 680 { 681 set_bdi_congested(&q->backing_dev_info, rw); 682 } 683 684 extern void blk_start_queue(struct request_queue *q); 685 extern void blk_stop_queue(struct request_queue *q); 686 extern void blk_sync_queue(struct request_queue *q); 687 extern void __blk_stop_queue(struct request_queue *q); 688 extern void blk_run_queue(struct request_queue *); 689 extern void blk_start_queueing(struct request_queue *); 690 extern int blk_rq_map_user(struct request_queue *, struct request *, void __user *, unsigned long); 691 extern int blk_rq_unmap_user(struct bio *); 692 extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, unsigned int, gfp_t); 693 extern int blk_rq_map_user_iov(struct request_queue *, struct request *, 694 struct sg_iovec *, int, unsigned int); 695 extern int blk_execute_rq(struct request_queue *, struct gendisk *, 696 struct request *, int); 697 extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *, 698 struct request *, int, rq_end_io_fn *); 699 extern int blk_verify_command(unsigned char *, int); 700 701 static inline struct request_queue *bdev_get_queue(struct block_device *bdev) 702 { 703 return bdev->bd_disk->queue; 704 } 705 706 static inline void blk_run_backing_dev(struct backing_dev_info *bdi, 707 struct page *page) 708 { 709 if (bdi && bdi->unplug_io_fn) 710 bdi->unplug_io_fn(bdi, page); 711 } 712 713 static inline void blk_run_address_space(struct address_space *mapping) 714 { 715 if (mapping) 716 blk_run_backing_dev(mapping->backing_dev_info, NULL); 717 } 718 719 /* 720 * end_request() and friends. Must be called with the request queue spinlock 721 * acquired. All functions called within end_request() _must_be_ atomic. 722 * 723 * Several drivers define their own end_request and call 724 * end_that_request_first() and end_that_request_last() 725 * for parts of the original function. This prevents 726 * code duplication in drivers. 727 */ 728 extern int end_that_request_first(struct request *, int, int); 729 extern int end_that_request_chunk(struct request *, int, int); 730 extern void end_that_request_last(struct request *, int); 731 extern void end_request(struct request *, int); 732 extern void end_queued_request(struct request *, int); 733 extern void end_dequeued_request(struct request *, int); 734 extern void blk_complete_request(struct request *); 735 736 /* 737 * end_that_request_first/chunk() takes an uptodate argument. we account 738 * any value <= as an io error. 0 means -EIO for compatability reasons, 739 * any other < 0 value is the direct error type. An uptodate value of 740 * 1 indicates successful io completion 741 */ 742 #define end_io_error(uptodate) (unlikely((uptodate) <= 0)) 743 744 static inline void blkdev_dequeue_request(struct request *req) 745 { 746 elv_dequeue_request(req->q, req); 747 } 748 749 /* 750 * Access functions for manipulating queue properties 751 */ 752 extern struct request_queue *blk_init_queue_node(request_fn_proc *rfn, 753 spinlock_t *lock, int node_id); 754 extern struct request_queue *blk_init_queue(request_fn_proc *, spinlock_t *); 755 extern void blk_cleanup_queue(struct request_queue *); 756 extern void blk_queue_make_request(struct request_queue *, make_request_fn *); 757 extern void blk_queue_bounce_limit(struct request_queue *, u64); 758 extern void blk_queue_max_sectors(struct request_queue *, unsigned int); 759 extern void blk_queue_max_phys_segments(struct request_queue *, unsigned short); 760 extern void blk_queue_max_hw_segments(struct request_queue *, unsigned short); 761 extern void blk_queue_max_segment_size(struct request_queue *, unsigned int); 762 extern void blk_queue_hardsect_size(struct request_queue *, unsigned short); 763 extern void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b); 764 extern void blk_queue_segment_boundary(struct request_queue *, unsigned long); 765 extern void blk_queue_prep_rq(struct request_queue *, prep_rq_fn *pfn); 766 extern void blk_queue_merge_bvec(struct request_queue *, merge_bvec_fn *); 767 extern void blk_queue_dma_alignment(struct request_queue *, int); 768 extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *); 769 extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev); 770 extern int blk_queue_ordered(struct request_queue *, unsigned, prepare_flush_fn *); 771 extern int blk_do_ordered(struct request_queue *, struct request **); 772 extern unsigned blk_ordered_cur_seq(struct request_queue *); 773 extern unsigned blk_ordered_req_seq(struct request *); 774 extern void blk_ordered_complete_seq(struct request_queue *, unsigned, int); 775 776 extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *); 777 extern void blk_dump_rq_flags(struct request *, char *); 778 extern void generic_unplug_device(struct request_queue *); 779 extern void __generic_unplug_device(struct request_queue *); 780 extern long nr_blockdev_pages(void); 781 782 int blk_get_queue(struct request_queue *); 783 struct request_queue *blk_alloc_queue(gfp_t); 784 struct request_queue *blk_alloc_queue_node(gfp_t, int); 785 extern void blk_put_queue(struct request_queue *); 786 787 /* 788 * tag stuff 789 */ 790 #define blk_queue_tag_depth(q) ((q)->queue_tags->busy) 791 #define blk_queue_tag_queue(q) ((q)->queue_tags->busy < (q)->queue_tags->max_depth) 792 #define blk_rq_tagged(rq) ((rq)->cmd_flags & REQ_QUEUED) 793 extern int blk_queue_start_tag(struct request_queue *, struct request *); 794 extern struct request *blk_queue_find_tag(struct request_queue *, int); 795 extern void blk_queue_end_tag(struct request_queue *, struct request *); 796 extern int blk_queue_init_tags(struct request_queue *, int, struct blk_queue_tag *); 797 extern void blk_queue_free_tags(struct request_queue *); 798 extern int blk_queue_resize_tags(struct request_queue *, int); 799 extern void blk_queue_invalidate_tags(struct request_queue *); 800 extern struct blk_queue_tag *blk_init_tags(int); 801 extern void blk_free_tags(struct blk_queue_tag *); 802 803 static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt, 804 int tag) 805 { 806 if (unlikely(bqt == NULL || tag >= bqt->real_max_depth)) 807 return NULL; 808 return bqt->tag_index[tag]; 809 } 810 811 extern int blkdev_issue_flush(struct block_device *, sector_t *); 812 813 #define MAX_PHYS_SEGMENTS 128 814 #define MAX_HW_SEGMENTS 128 815 #define SAFE_MAX_SECTORS 255 816 #define BLK_DEF_MAX_SECTORS 1024 817 818 #define MAX_SEGMENT_SIZE 65536 819 820 #define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist) 821 822 static inline int queue_hardsect_size(struct request_queue *q) 823 { 824 int retval = 512; 825 826 if (q && q->hardsect_size) 827 retval = q->hardsect_size; 828 829 return retval; 830 } 831 832 static inline int bdev_hardsect_size(struct block_device *bdev) 833 { 834 return queue_hardsect_size(bdev_get_queue(bdev)); 835 } 836 837 static inline int queue_dma_alignment(struct request_queue *q) 838 { 839 int retval = 511; 840 841 if (q && q->dma_alignment) 842 retval = q->dma_alignment; 843 844 return retval; 845 } 846 847 /* assumes size > 256 */ 848 static inline unsigned int blksize_bits(unsigned int size) 849 { 850 unsigned int bits = 8; 851 do { 852 bits++; 853 size >>= 1; 854 } while (size > 256); 855 return bits; 856 } 857 858 static inline unsigned int block_size(struct block_device *bdev) 859 { 860 return bdev->bd_block_size; 861 } 862 863 typedef struct {struct page *v;} Sector; 864 865 unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *); 866 867 static inline void put_dev_sector(Sector p) 868 { 869 page_cache_release(p.v); 870 } 871 872 struct work_struct; 873 int kblockd_schedule_work(struct work_struct *work); 874 void kblockd_flush_work(struct work_struct *work); 875 876 #define MODULE_ALIAS_BLOCKDEV(major,minor) \ 877 MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor)) 878 #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \ 879 MODULE_ALIAS("block-major-" __stringify(major) "-*") 880 881 882 #else /* CONFIG_BLOCK */ 883 /* 884 * stubs for when the block layer is configured out 885 */ 886 #define buffer_heads_over_limit 0 887 888 static inline long nr_blockdev_pages(void) 889 { 890 return 0; 891 } 892 893 static inline void exit_io_context(void) 894 { 895 } 896 897 #endif /* CONFIG_BLOCK */ 898 899 #endif 900