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