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 struct elevator_queue; 27 typedef struct elevator_queue elevator_t; 28 struct request_pm_state; 29 struct blk_trace; 30 struct request; 31 struct sg_io_hdr; 32 33 #define BLKDEV_MIN_RQ 4 34 #define BLKDEV_MAX_RQ 128 /* Default maximum */ 35 36 struct request; 37 typedef void (rq_end_io_fn)(struct request *, int); 38 39 struct request_list { 40 int count[2]; 41 int starved[2]; 42 int elvpriv; 43 mempool_t *rq_pool; 44 wait_queue_head_t wait[2]; 45 }; 46 47 /* 48 * request command types 49 */ 50 enum rq_cmd_type_bits { 51 REQ_TYPE_FS = 1, /* fs request */ 52 REQ_TYPE_BLOCK_PC, /* scsi command */ 53 REQ_TYPE_SENSE, /* sense request */ 54 REQ_TYPE_PM_SUSPEND, /* suspend request */ 55 REQ_TYPE_PM_RESUME, /* resume request */ 56 REQ_TYPE_PM_SHUTDOWN, /* shutdown request */ 57 REQ_TYPE_FLUSH, /* flush request */ 58 REQ_TYPE_SPECIAL, /* driver defined type */ 59 REQ_TYPE_LINUX_BLOCK, /* generic block layer message */ 60 /* 61 * for ATA/ATAPI devices. this really doesn't belong here, ide should 62 * use REQ_TYPE_SPECIAL and use rq->cmd[0] with the range of driver 63 * private REQ_LB opcodes to differentiate what type of request this is 64 */ 65 REQ_TYPE_ATA_TASKFILE, 66 REQ_TYPE_ATA_PC, 67 }; 68 69 /* 70 * For request of type REQ_TYPE_LINUX_BLOCK, rq->cmd[0] is the opcode being 71 * sent down (similar to how REQ_TYPE_BLOCK_PC means that ->cmd[] holds a 72 * SCSI cdb. 73 * 74 * 0x00 -> 0x3f are driver private, to be used for whatever purpose they need, 75 * typically to differentiate REQ_TYPE_SPECIAL requests. 76 * 77 */ 78 enum { 79 /* 80 * just examples for now 81 */ 82 REQ_LB_OP_EJECT = 0x40, /* eject request */ 83 REQ_LB_OP_FLUSH = 0x41, /* flush device */ 84 }; 85 86 /* 87 * request type modified bits. first three bits match BIO_RW* bits, important 88 */ 89 enum rq_flag_bits { 90 __REQ_RW, /* not set, read. set, write */ 91 __REQ_FAILFAST, /* no low level driver retries */ 92 __REQ_SORTED, /* elevator knows about this request */ 93 __REQ_SOFTBARRIER, /* may not be passed by ioscheduler */ 94 __REQ_HARDBARRIER, /* may not be passed by drive either */ 95 __REQ_FUA, /* forced unit access */ 96 __REQ_NOMERGE, /* don't touch this for merging */ 97 __REQ_STARTED, /* drive already may have started this one */ 98 __REQ_DONTPREP, /* don't call prep for this one */ 99 __REQ_QUEUED, /* uses queueing */ 100 __REQ_ELVPRIV, /* elevator private data attached */ 101 __REQ_FAILED, /* set if the request failed */ 102 __REQ_QUIET, /* don't worry about errors */ 103 __REQ_PREEMPT, /* set for "ide_preempt" requests */ 104 __REQ_ORDERED_COLOR, /* is before or after barrier */ 105 __REQ_RW_SYNC, /* request is sync (O_DIRECT) */ 106 __REQ_ALLOCED, /* request came from our alloc pool */ 107 __REQ_RW_META, /* metadata io request */ 108 __REQ_COPY_USER, /* contains copies of user pages */ 109 __REQ_INTEGRITY, /* integrity metadata has been remapped */ 110 __REQ_NR_BITS, /* stops here */ 111 }; 112 113 #define REQ_RW (1 << __REQ_RW) 114 #define REQ_FAILFAST (1 << __REQ_FAILFAST) 115 #define REQ_SORTED (1 << __REQ_SORTED) 116 #define REQ_SOFTBARRIER (1 << __REQ_SOFTBARRIER) 117 #define REQ_HARDBARRIER (1 << __REQ_HARDBARRIER) 118 #define REQ_FUA (1 << __REQ_FUA) 119 #define REQ_NOMERGE (1 << __REQ_NOMERGE) 120 #define REQ_STARTED (1 << __REQ_STARTED) 121 #define REQ_DONTPREP (1 << __REQ_DONTPREP) 122 #define REQ_QUEUED (1 << __REQ_QUEUED) 123 #define REQ_ELVPRIV (1 << __REQ_ELVPRIV) 124 #define REQ_FAILED (1 << __REQ_FAILED) 125 #define REQ_QUIET (1 << __REQ_QUIET) 126 #define REQ_PREEMPT (1 << __REQ_PREEMPT) 127 #define REQ_ORDERED_COLOR (1 << __REQ_ORDERED_COLOR) 128 #define REQ_RW_SYNC (1 << __REQ_RW_SYNC) 129 #define REQ_ALLOCED (1 << __REQ_ALLOCED) 130 #define REQ_RW_META (1 << __REQ_RW_META) 131 #define REQ_COPY_USER (1 << __REQ_COPY_USER) 132 #define REQ_INTEGRITY (1 << __REQ_INTEGRITY) 133 134 #define BLK_MAX_CDB 16 135 136 /* 137 * try to put the fields that are referenced together in the same cacheline. 138 * if you modify this structure, be sure to check block/blk-core.c:rq_init() 139 * as well! 140 */ 141 struct request { 142 struct list_head queuelist; 143 struct list_head donelist; 144 145 struct request_queue *q; 146 147 unsigned int cmd_flags; 148 enum rq_cmd_type_bits cmd_type; 149 150 /* Maintain bio traversal state for part by part I/O submission. 151 * hard_* are block layer internals, no driver should touch them! 152 */ 153 154 sector_t sector; /* next sector to submit */ 155 sector_t hard_sector; /* next sector to complete */ 156 unsigned long nr_sectors; /* no. of sectors left to submit */ 157 unsigned long hard_nr_sectors; /* no. of sectors left to complete */ 158 /* no. of sectors left to submit in the current segment */ 159 unsigned int current_nr_sectors; 160 161 /* no. of sectors left to complete in the current segment */ 162 unsigned int hard_cur_sectors; 163 164 struct bio *bio; 165 struct bio *biotail; 166 167 struct hlist_node hash; /* merge hash */ 168 /* 169 * The rb_node is only used inside the io scheduler, requests 170 * are pruned when moved to the dispatch queue. So let the 171 * completion_data share space with the rb_node. 172 */ 173 union { 174 struct rb_node rb_node; /* sort/lookup */ 175 void *completion_data; 176 }; 177 178 /* 179 * two pointers are available for the IO schedulers, if they need 180 * more they have to dynamically allocate it. 181 */ 182 void *elevator_private; 183 void *elevator_private2; 184 185 struct gendisk *rq_disk; 186 unsigned long start_time; 187 188 /* Number of scatter-gather DMA addr+len pairs after 189 * physical address coalescing is performed. 190 */ 191 unsigned short nr_phys_segments; 192 193 /* Number of scatter-gather addr+len pairs after 194 * physical and DMA remapping hardware coalescing is performed. 195 * This is the number of scatter-gather entries the driver 196 * will actually have to deal with after DMA mapping is done. 197 */ 198 unsigned short nr_hw_segments; 199 200 unsigned short ioprio; 201 202 void *special; 203 char *buffer; 204 205 int tag; 206 int errors; 207 208 int ref_count; 209 210 /* 211 * when request is used as a packet command carrier 212 */ 213 unsigned short cmd_len; 214 unsigned char __cmd[BLK_MAX_CDB]; 215 unsigned char *cmd; 216 217 unsigned int data_len; 218 unsigned int extra_len; /* length of alignment and padding */ 219 unsigned int sense_len; 220 void *data; 221 void *sense; 222 223 unsigned int timeout; 224 int retries; 225 226 /* 227 * completion callback. 228 */ 229 rq_end_io_fn *end_io; 230 void *end_io_data; 231 232 /* for bidi */ 233 struct request *next_rq; 234 }; 235 236 /* 237 * State information carried for REQ_TYPE_PM_SUSPEND and REQ_TYPE_PM_RESUME 238 * requests. Some step values could eventually be made generic. 239 */ 240 struct request_pm_state 241 { 242 /* PM state machine step value, currently driver specific */ 243 int pm_step; 244 /* requested PM state value (S1, S2, S3, S4, ...) */ 245 u32 pm_state; 246 void* data; /* for driver use */ 247 }; 248 249 #include <linux/elevator.h> 250 251 typedef void (request_fn_proc) (struct request_queue *q); 252 typedef int (make_request_fn) (struct request_queue *q, struct bio *bio); 253 typedef int (prep_rq_fn) (struct request_queue *, struct request *); 254 typedef void (unplug_fn) (struct request_queue *); 255 256 struct bio_vec; 257 struct bvec_merge_data { 258 struct block_device *bi_bdev; 259 sector_t bi_sector; 260 unsigned bi_size; 261 unsigned long bi_rw; 262 }; 263 typedef int (merge_bvec_fn) (struct request_queue *, struct bvec_merge_data *, 264 struct bio_vec *); 265 typedef void (prepare_flush_fn) (struct request_queue *, struct request *); 266 typedef void (softirq_done_fn)(struct request *); 267 typedef int (dma_drain_needed_fn)(struct request *); 268 269 enum blk_queue_state { 270 Queue_down, 271 Queue_up, 272 }; 273 274 struct blk_queue_tag { 275 struct request **tag_index; /* map of busy tags */ 276 unsigned long *tag_map; /* bit map of free/busy tags */ 277 int busy; /* current depth */ 278 int max_depth; /* what we will send to device */ 279 int real_max_depth; /* what the array can hold */ 280 atomic_t refcnt; /* map can be shared */ 281 }; 282 283 struct request_queue 284 { 285 /* 286 * Together with queue_head for cacheline sharing 287 */ 288 struct list_head queue_head; 289 struct request *last_merge; 290 elevator_t *elevator; 291 292 /* 293 * the queue request freelist, one for reads and one for writes 294 */ 295 struct request_list rq; 296 297 request_fn_proc *request_fn; 298 make_request_fn *make_request_fn; 299 prep_rq_fn *prep_rq_fn; 300 unplug_fn *unplug_fn; 301 merge_bvec_fn *merge_bvec_fn; 302 prepare_flush_fn *prepare_flush_fn; 303 softirq_done_fn *softirq_done_fn; 304 dma_drain_needed_fn *dma_drain_needed; 305 306 /* 307 * Dispatch queue sorting 308 */ 309 sector_t end_sector; 310 struct request *boundary_rq; 311 312 /* 313 * Auto-unplugging state 314 */ 315 struct timer_list unplug_timer; 316 int unplug_thresh; /* After this many requests */ 317 unsigned long unplug_delay; /* After this many jiffies */ 318 struct work_struct unplug_work; 319 320 struct backing_dev_info backing_dev_info; 321 322 /* 323 * The queue owner gets to use this for whatever they like. 324 * ll_rw_blk doesn't touch it. 325 */ 326 void *queuedata; 327 328 /* 329 * queue needs bounce pages for pages above this limit 330 */ 331 unsigned long bounce_pfn; 332 gfp_t bounce_gfp; 333 334 /* 335 * various queue flags, see QUEUE_* below 336 */ 337 unsigned long queue_flags; 338 339 /* 340 * protects queue structures from reentrancy. ->__queue_lock should 341 * _never_ be used directly, it is queue private. always use 342 * ->queue_lock. 343 */ 344 spinlock_t __queue_lock; 345 spinlock_t *queue_lock; 346 347 /* 348 * queue kobject 349 */ 350 struct kobject kobj; 351 352 /* 353 * queue settings 354 */ 355 unsigned long nr_requests; /* Max # of requests */ 356 unsigned int nr_congestion_on; 357 unsigned int nr_congestion_off; 358 unsigned int nr_batching; 359 360 unsigned int max_sectors; 361 unsigned int max_hw_sectors; 362 unsigned short max_phys_segments; 363 unsigned short max_hw_segments; 364 unsigned short hardsect_size; 365 unsigned int max_segment_size; 366 367 unsigned long seg_boundary_mask; 368 void *dma_drain_buffer; 369 unsigned int dma_drain_size; 370 unsigned int dma_pad_mask; 371 unsigned int dma_alignment; 372 373 struct blk_queue_tag *queue_tags; 374 struct list_head tag_busy_list; 375 376 unsigned int nr_sorted; 377 unsigned int in_flight; 378 379 /* 380 * sg stuff 381 */ 382 unsigned int sg_timeout; 383 unsigned int sg_reserved_size; 384 int node; 385 #ifdef CONFIG_BLK_DEV_IO_TRACE 386 struct blk_trace *blk_trace; 387 #endif 388 /* 389 * reserved for flush operations 390 */ 391 unsigned int ordered, next_ordered, ordseq; 392 int orderr, ordcolor; 393 struct request pre_flush_rq, bar_rq, post_flush_rq; 394 struct request *orig_bar_rq; 395 396 struct mutex sysfs_lock; 397 398 #if defined(CONFIG_BLK_DEV_BSG) 399 struct bsg_class_device bsg_dev; 400 #endif 401 }; 402 403 #define QUEUE_FLAG_CLUSTER 0 /* cluster several segments into 1 */ 404 #define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */ 405 #define QUEUE_FLAG_STOPPED 2 /* queue is stopped */ 406 #define QUEUE_FLAG_READFULL 3 /* read queue has been filled */ 407 #define QUEUE_FLAG_WRITEFULL 4 /* write queue has been filled */ 408 #define QUEUE_FLAG_DEAD 5 /* queue being torn down */ 409 #define QUEUE_FLAG_REENTER 6 /* Re-entrancy avoidance */ 410 #define QUEUE_FLAG_PLUGGED 7 /* queue is plugged */ 411 #define QUEUE_FLAG_ELVSWITCH 8 /* don't use elevator, just do FIFO */ 412 #define QUEUE_FLAG_BIDI 9 /* queue supports bidi requests */ 413 #define QUEUE_FLAG_NOMERGES 10 /* disable merge attempts */ 414 415 static inline int queue_is_locked(struct request_queue *q) 416 { 417 #ifdef CONFIG_SMP 418 spinlock_t *lock = q->queue_lock; 419 return lock && spin_is_locked(lock); 420 #else 421 return 1; 422 #endif 423 } 424 425 static inline void queue_flag_set_unlocked(unsigned int flag, 426 struct request_queue *q) 427 { 428 __set_bit(flag, &q->queue_flags); 429 } 430 431 static inline int queue_flag_test_and_clear(unsigned int flag, 432 struct request_queue *q) 433 { 434 WARN_ON_ONCE(!queue_is_locked(q)); 435 436 if (test_bit(flag, &q->queue_flags)) { 437 __clear_bit(flag, &q->queue_flags); 438 return 1; 439 } 440 441 return 0; 442 } 443 444 static inline int queue_flag_test_and_set(unsigned int flag, 445 struct request_queue *q) 446 { 447 WARN_ON_ONCE(!queue_is_locked(q)); 448 449 if (!test_bit(flag, &q->queue_flags)) { 450 __set_bit(flag, &q->queue_flags); 451 return 0; 452 } 453 454 return 1; 455 } 456 457 static inline void queue_flag_set(unsigned int flag, struct request_queue *q) 458 { 459 WARN_ON_ONCE(!queue_is_locked(q)); 460 __set_bit(flag, &q->queue_flags); 461 } 462 463 static inline void queue_flag_clear_unlocked(unsigned int flag, 464 struct request_queue *q) 465 { 466 __clear_bit(flag, &q->queue_flags); 467 } 468 469 static inline void queue_flag_clear(unsigned int flag, struct request_queue *q) 470 { 471 WARN_ON_ONCE(!queue_is_locked(q)); 472 __clear_bit(flag, &q->queue_flags); 473 } 474 475 enum { 476 /* 477 * Hardbarrier is supported with one of the following methods. 478 * 479 * NONE : hardbarrier unsupported 480 * DRAIN : ordering by draining is enough 481 * DRAIN_FLUSH : ordering by draining w/ pre and post flushes 482 * DRAIN_FUA : ordering by draining w/ pre flush and FUA write 483 * TAG : ordering by tag is enough 484 * TAG_FLUSH : ordering by tag w/ pre and post flushes 485 * TAG_FUA : ordering by tag w/ pre flush and FUA write 486 */ 487 QUEUE_ORDERED_NONE = 0x00, 488 QUEUE_ORDERED_DRAIN = 0x01, 489 QUEUE_ORDERED_TAG = 0x02, 490 491 QUEUE_ORDERED_PREFLUSH = 0x10, 492 QUEUE_ORDERED_POSTFLUSH = 0x20, 493 QUEUE_ORDERED_FUA = 0x40, 494 495 QUEUE_ORDERED_DRAIN_FLUSH = QUEUE_ORDERED_DRAIN | 496 QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_POSTFLUSH, 497 QUEUE_ORDERED_DRAIN_FUA = QUEUE_ORDERED_DRAIN | 498 QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_FUA, 499 QUEUE_ORDERED_TAG_FLUSH = QUEUE_ORDERED_TAG | 500 QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_POSTFLUSH, 501 QUEUE_ORDERED_TAG_FUA = QUEUE_ORDERED_TAG | 502 QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_FUA, 503 504 /* 505 * Ordered operation sequence 506 */ 507 QUEUE_ORDSEQ_STARTED = 0x01, /* flushing in progress */ 508 QUEUE_ORDSEQ_DRAIN = 0x02, /* waiting for the queue to be drained */ 509 QUEUE_ORDSEQ_PREFLUSH = 0x04, /* pre-flushing in progress */ 510 QUEUE_ORDSEQ_BAR = 0x08, /* original barrier req in progress */ 511 QUEUE_ORDSEQ_POSTFLUSH = 0x10, /* post-flushing in progress */ 512 QUEUE_ORDSEQ_DONE = 0x20, 513 }; 514 515 #define blk_queue_plugged(q) test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags) 516 #define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags) 517 #define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags) 518 #define blk_queue_nomerges(q) test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags) 519 #define blk_queue_flushing(q) ((q)->ordseq) 520 521 #define blk_fs_request(rq) ((rq)->cmd_type == REQ_TYPE_FS) 522 #define blk_pc_request(rq) ((rq)->cmd_type == REQ_TYPE_BLOCK_PC) 523 #define blk_special_request(rq) ((rq)->cmd_type == REQ_TYPE_SPECIAL) 524 #define blk_sense_request(rq) ((rq)->cmd_type == REQ_TYPE_SENSE) 525 526 #define blk_noretry_request(rq) ((rq)->cmd_flags & REQ_FAILFAST) 527 #define blk_rq_started(rq) ((rq)->cmd_flags & REQ_STARTED) 528 529 #define blk_account_rq(rq) (blk_rq_started(rq) && blk_fs_request(rq)) 530 531 #define blk_pm_suspend_request(rq) ((rq)->cmd_type == REQ_TYPE_PM_SUSPEND) 532 #define blk_pm_resume_request(rq) ((rq)->cmd_type == REQ_TYPE_PM_RESUME) 533 #define blk_pm_request(rq) \ 534 (blk_pm_suspend_request(rq) || blk_pm_resume_request(rq)) 535 536 #define blk_sorted_rq(rq) ((rq)->cmd_flags & REQ_SORTED) 537 #define blk_barrier_rq(rq) ((rq)->cmd_flags & REQ_HARDBARRIER) 538 #define blk_fua_rq(rq) ((rq)->cmd_flags & REQ_FUA) 539 #define blk_bidi_rq(rq) ((rq)->next_rq != NULL) 540 #define blk_empty_barrier(rq) (blk_barrier_rq(rq) && blk_fs_request(rq) && !(rq)->hard_nr_sectors) 541 /* rq->queuelist of dequeued request must be list_empty() */ 542 #define blk_queued_rq(rq) (!list_empty(&(rq)->queuelist)) 543 544 #define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist) 545 546 #define rq_data_dir(rq) ((rq)->cmd_flags & 1) 547 548 /* 549 * We regard a request as sync, if it's a READ or a SYNC write. 550 */ 551 #define rq_is_sync(rq) (rq_data_dir((rq)) == READ || (rq)->cmd_flags & REQ_RW_SYNC) 552 #define rq_is_meta(rq) ((rq)->cmd_flags & REQ_RW_META) 553 554 static inline int blk_queue_full(struct request_queue *q, int rw) 555 { 556 if (rw == READ) 557 return test_bit(QUEUE_FLAG_READFULL, &q->queue_flags); 558 return test_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags); 559 } 560 561 static inline void blk_set_queue_full(struct request_queue *q, int rw) 562 { 563 if (rw == READ) 564 queue_flag_set(QUEUE_FLAG_READFULL, q); 565 else 566 queue_flag_set(QUEUE_FLAG_WRITEFULL, q); 567 } 568 569 static inline void blk_clear_queue_full(struct request_queue *q, int rw) 570 { 571 if (rw == READ) 572 queue_flag_clear(QUEUE_FLAG_READFULL, q); 573 else 574 queue_flag_clear(QUEUE_FLAG_WRITEFULL, q); 575 } 576 577 578 /* 579 * mergeable request must not have _NOMERGE or _BARRIER bit set, nor may 580 * it already be started by driver. 581 */ 582 #define RQ_NOMERGE_FLAGS \ 583 (REQ_NOMERGE | REQ_STARTED | REQ_HARDBARRIER | REQ_SOFTBARRIER) 584 #define rq_mergeable(rq) \ 585 (!((rq)->cmd_flags & RQ_NOMERGE_FLAGS) && blk_fs_request((rq))) 586 587 /* 588 * q->prep_rq_fn return values 589 */ 590 #define BLKPREP_OK 0 /* serve it */ 591 #define BLKPREP_KILL 1 /* fatal error, kill */ 592 #define BLKPREP_DEFER 2 /* leave on queue */ 593 594 extern unsigned long blk_max_low_pfn, blk_max_pfn; 595 596 /* 597 * standard bounce addresses: 598 * 599 * BLK_BOUNCE_HIGH : bounce all highmem pages 600 * BLK_BOUNCE_ANY : don't bounce anything 601 * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary 602 */ 603 604 #if BITS_PER_LONG == 32 605 #define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT) 606 #else 607 #define BLK_BOUNCE_HIGH -1ULL 608 #endif 609 #define BLK_BOUNCE_ANY (-1ULL) 610 #define BLK_BOUNCE_ISA (ISA_DMA_THRESHOLD) 611 612 /* 613 * default timeout for SG_IO if none specified 614 */ 615 #define BLK_DEFAULT_SG_TIMEOUT (60 * HZ) 616 617 #ifdef CONFIG_BOUNCE 618 extern int init_emergency_isa_pool(void); 619 extern void blk_queue_bounce(struct request_queue *q, struct bio **bio); 620 #else 621 static inline int init_emergency_isa_pool(void) 622 { 623 return 0; 624 } 625 static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio) 626 { 627 } 628 #endif /* CONFIG_MMU */ 629 630 struct req_iterator { 631 int i; 632 struct bio *bio; 633 }; 634 635 /* This should not be used directly - use rq_for_each_segment */ 636 #define __rq_for_each_bio(_bio, rq) \ 637 if ((rq->bio)) \ 638 for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next) 639 640 #define rq_for_each_segment(bvl, _rq, _iter) \ 641 __rq_for_each_bio(_iter.bio, _rq) \ 642 bio_for_each_segment(bvl, _iter.bio, _iter.i) 643 644 #define rq_iter_last(rq, _iter) \ 645 (_iter.bio->bi_next == NULL && _iter.i == _iter.bio->bi_vcnt-1) 646 647 extern int blk_register_queue(struct gendisk *disk); 648 extern void blk_unregister_queue(struct gendisk *disk); 649 extern void register_disk(struct gendisk *dev); 650 extern void generic_make_request(struct bio *bio); 651 extern void blk_rq_init(struct request_queue *q, struct request *rq); 652 extern void blk_put_request(struct request *); 653 extern void __blk_put_request(struct request_queue *, struct request *); 654 extern struct request *blk_get_request(struct request_queue *, int, gfp_t); 655 extern void blk_insert_request(struct request_queue *, struct request *, int, void *); 656 extern void blk_requeue_request(struct request_queue *, struct request *); 657 extern void blk_plug_device(struct request_queue *); 658 extern int blk_remove_plug(struct request_queue *); 659 extern void blk_recount_segments(struct request_queue *, struct bio *); 660 extern int scsi_cmd_ioctl(struct file *, struct request_queue *, 661 struct gendisk *, unsigned int, void __user *); 662 extern int sg_scsi_ioctl(struct file *, struct request_queue *, 663 struct gendisk *, struct scsi_ioctl_command __user *); 664 665 /* 666 * Temporary export, until SCSI gets fixed up. 667 */ 668 extern int blk_rq_append_bio(struct request_queue *q, struct request *rq, 669 struct bio *bio); 670 671 /* 672 * A queue has just exitted congestion. Note this in the global counter of 673 * congested queues, and wake up anyone who was waiting for requests to be 674 * put back. 675 */ 676 static inline void blk_clear_queue_congested(struct request_queue *q, int rw) 677 { 678 clear_bdi_congested(&q->backing_dev_info, rw); 679 } 680 681 /* 682 * A queue has just entered congestion. Flag that in the queue's VM-visible 683 * state flags and increment the global gounter of congested queues. 684 */ 685 static inline void blk_set_queue_congested(struct request_queue *q, int rw) 686 { 687 set_bdi_congested(&q->backing_dev_info, rw); 688 } 689 690 extern void blk_start_queue(struct request_queue *q); 691 extern void blk_stop_queue(struct request_queue *q); 692 extern void blk_sync_queue(struct request_queue *q); 693 extern void __blk_stop_queue(struct request_queue *q); 694 extern void __blk_run_queue(struct request_queue *); 695 extern void blk_run_queue(struct request_queue *); 696 extern void blk_start_queueing(struct request_queue *); 697 extern int blk_rq_map_user(struct request_queue *, struct request *, void __user *, unsigned long); 698 extern int blk_rq_unmap_user(struct bio *); 699 extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, unsigned int, gfp_t); 700 extern int blk_rq_map_user_iov(struct request_queue *, struct request *, 701 struct sg_iovec *, int, unsigned int); 702 extern int blk_execute_rq(struct request_queue *, struct gendisk *, 703 struct request *, int); 704 extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *, 705 struct request *, int, rq_end_io_fn *); 706 extern void blk_unplug(struct request_queue *q); 707 708 static inline struct request_queue *bdev_get_queue(struct block_device *bdev) 709 { 710 return bdev->bd_disk->queue; 711 } 712 713 static inline void blk_run_backing_dev(struct backing_dev_info *bdi, 714 struct page *page) 715 { 716 if (bdi && bdi->unplug_io_fn) 717 bdi->unplug_io_fn(bdi, page); 718 } 719 720 static inline void blk_run_address_space(struct address_space *mapping) 721 { 722 if (mapping) 723 blk_run_backing_dev(mapping->backing_dev_info, NULL); 724 } 725 726 /* 727 * blk_end_request() and friends. 728 * __blk_end_request() and end_request() must be called with 729 * the request queue spinlock acquired. 730 * 731 * Several drivers define their own end_request and call 732 * blk_end_request() for parts of the original function. 733 * This prevents code duplication in drivers. 734 */ 735 extern int blk_end_request(struct request *rq, int error, 736 unsigned int nr_bytes); 737 extern int __blk_end_request(struct request *rq, int error, 738 unsigned int nr_bytes); 739 extern int blk_end_bidi_request(struct request *rq, int error, 740 unsigned int nr_bytes, unsigned int bidi_bytes); 741 extern void end_request(struct request *, int); 742 extern void end_queued_request(struct request *, int); 743 extern void end_dequeued_request(struct request *, int); 744 extern int blk_end_request_callback(struct request *rq, int error, 745 unsigned int nr_bytes, 746 int (drv_callback)(struct request *)); 747 extern void blk_complete_request(struct request *); 748 749 /* 750 * blk_end_request() takes bytes instead of sectors as a complete size. 751 * blk_rq_bytes() returns bytes left to complete in the entire request. 752 * blk_rq_cur_bytes() returns bytes left to complete in the current segment. 753 */ 754 extern unsigned int blk_rq_bytes(struct request *rq); 755 extern unsigned int blk_rq_cur_bytes(struct request *rq); 756 757 static inline void blkdev_dequeue_request(struct request *req) 758 { 759 elv_dequeue_request(req->q, req); 760 } 761 762 /* 763 * Access functions for manipulating queue properties 764 */ 765 extern struct request_queue *blk_init_queue_node(request_fn_proc *rfn, 766 spinlock_t *lock, int node_id); 767 extern struct request_queue *blk_init_queue(request_fn_proc *, spinlock_t *); 768 extern void blk_cleanup_queue(struct request_queue *); 769 extern void blk_queue_make_request(struct request_queue *, make_request_fn *); 770 extern void blk_queue_bounce_limit(struct request_queue *, u64); 771 extern void blk_queue_max_sectors(struct request_queue *, unsigned int); 772 extern void blk_queue_max_phys_segments(struct request_queue *, unsigned short); 773 extern void blk_queue_max_hw_segments(struct request_queue *, unsigned short); 774 extern void blk_queue_max_segment_size(struct request_queue *, unsigned int); 775 extern void blk_queue_hardsect_size(struct request_queue *, unsigned short); 776 extern void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b); 777 extern void blk_queue_dma_pad(struct request_queue *, unsigned int); 778 extern void blk_queue_update_dma_pad(struct request_queue *, unsigned int); 779 extern int blk_queue_dma_drain(struct request_queue *q, 780 dma_drain_needed_fn *dma_drain_needed, 781 void *buf, unsigned int size); 782 extern void blk_queue_segment_boundary(struct request_queue *, unsigned long); 783 extern void blk_queue_prep_rq(struct request_queue *, prep_rq_fn *pfn); 784 extern void blk_queue_merge_bvec(struct request_queue *, merge_bvec_fn *); 785 extern void blk_queue_dma_alignment(struct request_queue *, int); 786 extern void blk_queue_update_dma_alignment(struct request_queue *, int); 787 extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *); 788 extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev); 789 extern int blk_queue_ordered(struct request_queue *, unsigned, prepare_flush_fn *); 790 extern int blk_do_ordered(struct request_queue *, struct request **); 791 extern unsigned blk_ordered_cur_seq(struct request_queue *); 792 extern unsigned blk_ordered_req_seq(struct request *); 793 extern void blk_ordered_complete_seq(struct request_queue *, unsigned, int); 794 795 extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *); 796 extern void blk_dump_rq_flags(struct request *, char *); 797 extern void generic_unplug_device(struct request_queue *); 798 extern void __generic_unplug_device(struct request_queue *); 799 extern long nr_blockdev_pages(void); 800 801 int blk_get_queue(struct request_queue *); 802 struct request_queue *blk_alloc_queue(gfp_t); 803 struct request_queue *blk_alloc_queue_node(gfp_t, int); 804 extern void blk_put_queue(struct request_queue *); 805 806 /* 807 * tag stuff 808 */ 809 #define blk_queue_tag_depth(q) ((q)->queue_tags->busy) 810 #define blk_queue_tag_queue(q) ((q)->queue_tags->busy < (q)->queue_tags->max_depth) 811 #define blk_rq_tagged(rq) ((rq)->cmd_flags & REQ_QUEUED) 812 extern int blk_queue_start_tag(struct request_queue *, struct request *); 813 extern struct request *blk_queue_find_tag(struct request_queue *, int); 814 extern void blk_queue_end_tag(struct request_queue *, struct request *); 815 extern int blk_queue_init_tags(struct request_queue *, int, struct blk_queue_tag *); 816 extern void blk_queue_free_tags(struct request_queue *); 817 extern int blk_queue_resize_tags(struct request_queue *, int); 818 extern void blk_queue_invalidate_tags(struct request_queue *); 819 extern struct blk_queue_tag *blk_init_tags(int); 820 extern void blk_free_tags(struct blk_queue_tag *); 821 822 static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt, 823 int tag) 824 { 825 if (unlikely(bqt == NULL || tag >= bqt->real_max_depth)) 826 return NULL; 827 return bqt->tag_index[tag]; 828 } 829 830 extern int blkdev_issue_flush(struct block_device *, sector_t *); 831 832 /* 833 * command filter functions 834 */ 835 extern int blk_verify_command(struct file *file, unsigned char *cmd); 836 extern int blk_cmd_filter_verify_command(struct blk_scsi_cmd_filter *filter, 837 unsigned char *cmd, mode_t *f_mode); 838 extern int blk_register_filter(struct gendisk *disk); 839 extern void blk_unregister_filter(struct gendisk *disk); 840 841 #define MAX_PHYS_SEGMENTS 128 842 #define MAX_HW_SEGMENTS 128 843 #define SAFE_MAX_SECTORS 255 844 #define BLK_DEF_MAX_SECTORS 1024 845 846 #define MAX_SEGMENT_SIZE 65536 847 848 #define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist) 849 850 static inline int queue_hardsect_size(struct request_queue *q) 851 { 852 int retval = 512; 853 854 if (q && q->hardsect_size) 855 retval = q->hardsect_size; 856 857 return retval; 858 } 859 860 static inline int bdev_hardsect_size(struct block_device *bdev) 861 { 862 return queue_hardsect_size(bdev_get_queue(bdev)); 863 } 864 865 static inline int queue_dma_alignment(struct request_queue *q) 866 { 867 return q ? q->dma_alignment : 511; 868 } 869 870 /* assumes size > 256 */ 871 static inline unsigned int blksize_bits(unsigned int size) 872 { 873 unsigned int bits = 8; 874 do { 875 bits++; 876 size >>= 1; 877 } while (size > 256); 878 return bits; 879 } 880 881 static inline unsigned int block_size(struct block_device *bdev) 882 { 883 return bdev->bd_block_size; 884 } 885 886 typedef struct {struct page *v;} Sector; 887 888 unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *); 889 890 static inline void put_dev_sector(Sector p) 891 { 892 page_cache_release(p.v); 893 } 894 895 struct work_struct; 896 int kblockd_schedule_work(struct work_struct *work); 897 void kblockd_flush_work(struct work_struct *work); 898 899 #define MODULE_ALIAS_BLOCKDEV(major,minor) \ 900 MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor)) 901 #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \ 902 MODULE_ALIAS("block-major-" __stringify(major) "-*") 903 904 #if defined(CONFIG_BLK_DEV_INTEGRITY) 905 906 #define INTEGRITY_FLAG_READ 2 /* verify data integrity on read */ 907 #define INTEGRITY_FLAG_WRITE 4 /* generate data integrity on write */ 908 909 struct blk_integrity_exchg { 910 void *prot_buf; 911 void *data_buf; 912 sector_t sector; 913 unsigned int data_size; 914 unsigned short sector_size; 915 const char *disk_name; 916 }; 917 918 typedef void (integrity_gen_fn) (struct blk_integrity_exchg *); 919 typedef int (integrity_vrfy_fn) (struct blk_integrity_exchg *); 920 typedef void (integrity_set_tag_fn) (void *, void *, unsigned int); 921 typedef void (integrity_get_tag_fn) (void *, void *, unsigned int); 922 923 struct blk_integrity { 924 integrity_gen_fn *generate_fn; 925 integrity_vrfy_fn *verify_fn; 926 integrity_set_tag_fn *set_tag_fn; 927 integrity_get_tag_fn *get_tag_fn; 928 929 unsigned short flags; 930 unsigned short tuple_size; 931 unsigned short sector_size; 932 unsigned short tag_size; 933 934 const char *name; 935 936 struct kobject kobj; 937 }; 938 939 extern int blk_integrity_register(struct gendisk *, struct blk_integrity *); 940 extern void blk_integrity_unregister(struct gendisk *); 941 extern int blk_integrity_compare(struct block_device *, struct block_device *); 942 extern int blk_rq_map_integrity_sg(struct request *, struct scatterlist *); 943 extern int blk_rq_count_integrity_sg(struct request *); 944 945 static inline unsigned short blk_integrity_tuple_size(struct blk_integrity *bi) 946 { 947 if (bi) 948 return bi->tuple_size; 949 950 return 0; 951 } 952 953 static inline struct blk_integrity *bdev_get_integrity(struct block_device *bdev) 954 { 955 return bdev->bd_disk->integrity; 956 } 957 958 static inline unsigned int bdev_get_tag_size(struct block_device *bdev) 959 { 960 struct blk_integrity *bi = bdev_get_integrity(bdev); 961 962 if (bi) 963 return bi->tag_size; 964 965 return 0; 966 } 967 968 static inline int bdev_integrity_enabled(struct block_device *bdev, int rw) 969 { 970 struct blk_integrity *bi = bdev_get_integrity(bdev); 971 972 if (bi == NULL) 973 return 0; 974 975 if (rw == READ && bi->verify_fn != NULL && 976 (bi->flags & INTEGRITY_FLAG_READ)) 977 return 1; 978 979 if (rw == WRITE && bi->generate_fn != NULL && 980 (bi->flags & INTEGRITY_FLAG_WRITE)) 981 return 1; 982 983 return 0; 984 } 985 986 static inline int blk_integrity_rq(struct request *rq) 987 { 988 if (rq->bio == NULL) 989 return 0; 990 991 return bio_integrity(rq->bio); 992 } 993 994 #else /* CONFIG_BLK_DEV_INTEGRITY */ 995 996 #define blk_integrity_rq(rq) (0) 997 #define blk_rq_count_integrity_sg(a) (0) 998 #define blk_rq_map_integrity_sg(a, b) (0) 999 #define bdev_get_integrity(a) (0) 1000 #define bdev_get_tag_size(a) (0) 1001 #define blk_integrity_compare(a, b) (0) 1002 #define blk_integrity_register(a, b) (0) 1003 #define blk_integrity_unregister(a) do { } while (0); 1004 1005 #endif /* CONFIG_BLK_DEV_INTEGRITY */ 1006 1007 #else /* CONFIG_BLOCK */ 1008 /* 1009 * stubs for when the block layer is configured out 1010 */ 1011 #define buffer_heads_over_limit 0 1012 1013 static inline long nr_blockdev_pages(void) 1014 { 1015 return 0; 1016 } 1017 1018 #endif /* CONFIG_BLOCK */ 1019 1020 #endif 1021