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 #define BLK_SCSI_MAX_CMDS (256) 284 #define BLK_SCSI_CMD_PER_LONG (BLK_SCSI_MAX_CMDS / (sizeof(long) * 8)) 285 286 struct blk_cmd_filter { 287 unsigned long read_ok[BLK_SCSI_CMD_PER_LONG]; 288 unsigned long write_ok[BLK_SCSI_CMD_PER_LONG]; 289 struct kobject kobj; 290 }; 291 292 struct request_queue 293 { 294 /* 295 * Together with queue_head for cacheline sharing 296 */ 297 struct list_head queue_head; 298 struct request *last_merge; 299 elevator_t *elevator; 300 301 /* 302 * the queue request freelist, one for reads and one for writes 303 */ 304 struct request_list rq; 305 306 request_fn_proc *request_fn; 307 make_request_fn *make_request_fn; 308 prep_rq_fn *prep_rq_fn; 309 unplug_fn *unplug_fn; 310 merge_bvec_fn *merge_bvec_fn; 311 prepare_flush_fn *prepare_flush_fn; 312 softirq_done_fn *softirq_done_fn; 313 dma_drain_needed_fn *dma_drain_needed; 314 315 /* 316 * Dispatch queue sorting 317 */ 318 sector_t end_sector; 319 struct request *boundary_rq; 320 321 /* 322 * Auto-unplugging state 323 */ 324 struct timer_list unplug_timer; 325 int unplug_thresh; /* After this many requests */ 326 unsigned long unplug_delay; /* After this many jiffies */ 327 struct work_struct unplug_work; 328 329 struct backing_dev_info backing_dev_info; 330 331 /* 332 * The queue owner gets to use this for whatever they like. 333 * ll_rw_blk doesn't touch it. 334 */ 335 void *queuedata; 336 337 /* 338 * queue needs bounce pages for pages above this limit 339 */ 340 unsigned long bounce_pfn; 341 gfp_t bounce_gfp; 342 343 /* 344 * various queue flags, see QUEUE_* below 345 */ 346 unsigned long queue_flags; 347 348 /* 349 * protects queue structures from reentrancy. ->__queue_lock should 350 * _never_ be used directly, it is queue private. always use 351 * ->queue_lock. 352 */ 353 spinlock_t __queue_lock; 354 spinlock_t *queue_lock; 355 356 /* 357 * queue kobject 358 */ 359 struct kobject kobj; 360 361 /* 362 * queue settings 363 */ 364 unsigned long nr_requests; /* Max # of requests */ 365 unsigned int nr_congestion_on; 366 unsigned int nr_congestion_off; 367 unsigned int nr_batching; 368 369 unsigned int max_sectors; 370 unsigned int max_hw_sectors; 371 unsigned short max_phys_segments; 372 unsigned short max_hw_segments; 373 unsigned short hardsect_size; 374 unsigned int max_segment_size; 375 376 unsigned long seg_boundary_mask; 377 void *dma_drain_buffer; 378 unsigned int dma_drain_size; 379 unsigned int dma_pad_mask; 380 unsigned int dma_alignment; 381 382 struct blk_queue_tag *queue_tags; 383 struct list_head tag_busy_list; 384 385 unsigned int nr_sorted; 386 unsigned int in_flight; 387 388 /* 389 * sg stuff 390 */ 391 unsigned int sg_timeout; 392 unsigned int sg_reserved_size; 393 int node; 394 #ifdef CONFIG_BLK_DEV_IO_TRACE 395 struct blk_trace *blk_trace; 396 #endif 397 /* 398 * reserved for flush operations 399 */ 400 unsigned int ordered, next_ordered, ordseq; 401 int orderr, ordcolor; 402 struct request pre_flush_rq, bar_rq, post_flush_rq; 403 struct request *orig_bar_rq; 404 405 struct mutex sysfs_lock; 406 407 #if defined(CONFIG_BLK_DEV_BSG) 408 struct bsg_class_device bsg_dev; 409 #endif 410 struct blk_cmd_filter cmd_filter; 411 }; 412 413 #define QUEUE_FLAG_CLUSTER 0 /* cluster several segments into 1 */ 414 #define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */ 415 #define QUEUE_FLAG_STOPPED 2 /* queue is stopped */ 416 #define QUEUE_FLAG_READFULL 3 /* read queue has been filled */ 417 #define QUEUE_FLAG_WRITEFULL 4 /* write queue has been filled */ 418 #define QUEUE_FLAG_DEAD 5 /* queue being torn down */ 419 #define QUEUE_FLAG_REENTER 6 /* Re-entrancy avoidance */ 420 #define QUEUE_FLAG_PLUGGED 7 /* queue is plugged */ 421 #define QUEUE_FLAG_ELVSWITCH 8 /* don't use elevator, just do FIFO */ 422 #define QUEUE_FLAG_BIDI 9 /* queue supports bidi requests */ 423 #define QUEUE_FLAG_NOMERGES 10 /* disable merge attempts */ 424 425 static inline int queue_is_locked(struct request_queue *q) 426 { 427 #ifdef CONFIG_SMP 428 spinlock_t *lock = q->queue_lock; 429 return lock && spin_is_locked(lock); 430 #else 431 return 1; 432 #endif 433 } 434 435 static inline void queue_flag_set_unlocked(unsigned int flag, 436 struct request_queue *q) 437 { 438 __set_bit(flag, &q->queue_flags); 439 } 440 441 static inline int queue_flag_test_and_clear(unsigned int flag, 442 struct request_queue *q) 443 { 444 WARN_ON_ONCE(!queue_is_locked(q)); 445 446 if (test_bit(flag, &q->queue_flags)) { 447 __clear_bit(flag, &q->queue_flags); 448 return 1; 449 } 450 451 return 0; 452 } 453 454 static inline int queue_flag_test_and_set(unsigned int flag, 455 struct request_queue *q) 456 { 457 WARN_ON_ONCE(!queue_is_locked(q)); 458 459 if (!test_bit(flag, &q->queue_flags)) { 460 __set_bit(flag, &q->queue_flags); 461 return 0; 462 } 463 464 return 1; 465 } 466 467 static inline void queue_flag_set(unsigned int flag, struct request_queue *q) 468 { 469 WARN_ON_ONCE(!queue_is_locked(q)); 470 __set_bit(flag, &q->queue_flags); 471 } 472 473 static inline void queue_flag_clear_unlocked(unsigned int flag, 474 struct request_queue *q) 475 { 476 __clear_bit(flag, &q->queue_flags); 477 } 478 479 static inline void queue_flag_clear(unsigned int flag, struct request_queue *q) 480 { 481 WARN_ON_ONCE(!queue_is_locked(q)); 482 __clear_bit(flag, &q->queue_flags); 483 } 484 485 enum { 486 /* 487 * Hardbarrier is supported with one of the following methods. 488 * 489 * NONE : hardbarrier unsupported 490 * DRAIN : ordering by draining is enough 491 * DRAIN_FLUSH : ordering by draining w/ pre and post flushes 492 * DRAIN_FUA : ordering by draining w/ pre flush and FUA write 493 * TAG : ordering by tag is enough 494 * TAG_FLUSH : ordering by tag w/ pre and post flushes 495 * TAG_FUA : ordering by tag w/ pre flush and FUA write 496 */ 497 QUEUE_ORDERED_NONE = 0x00, 498 QUEUE_ORDERED_DRAIN = 0x01, 499 QUEUE_ORDERED_TAG = 0x02, 500 501 QUEUE_ORDERED_PREFLUSH = 0x10, 502 QUEUE_ORDERED_POSTFLUSH = 0x20, 503 QUEUE_ORDERED_FUA = 0x40, 504 505 QUEUE_ORDERED_DRAIN_FLUSH = QUEUE_ORDERED_DRAIN | 506 QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_POSTFLUSH, 507 QUEUE_ORDERED_DRAIN_FUA = QUEUE_ORDERED_DRAIN | 508 QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_FUA, 509 QUEUE_ORDERED_TAG_FLUSH = QUEUE_ORDERED_TAG | 510 QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_POSTFLUSH, 511 QUEUE_ORDERED_TAG_FUA = QUEUE_ORDERED_TAG | 512 QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_FUA, 513 514 /* 515 * Ordered operation sequence 516 */ 517 QUEUE_ORDSEQ_STARTED = 0x01, /* flushing in progress */ 518 QUEUE_ORDSEQ_DRAIN = 0x02, /* waiting for the queue to be drained */ 519 QUEUE_ORDSEQ_PREFLUSH = 0x04, /* pre-flushing in progress */ 520 QUEUE_ORDSEQ_BAR = 0x08, /* original barrier req in progress */ 521 QUEUE_ORDSEQ_POSTFLUSH = 0x10, /* post-flushing in progress */ 522 QUEUE_ORDSEQ_DONE = 0x20, 523 }; 524 525 #define blk_queue_plugged(q) test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags) 526 #define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags) 527 #define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags) 528 #define blk_queue_nomerges(q) test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags) 529 #define blk_queue_flushing(q) ((q)->ordseq) 530 531 #define blk_fs_request(rq) ((rq)->cmd_type == REQ_TYPE_FS) 532 #define blk_pc_request(rq) ((rq)->cmd_type == REQ_TYPE_BLOCK_PC) 533 #define blk_special_request(rq) ((rq)->cmd_type == REQ_TYPE_SPECIAL) 534 #define blk_sense_request(rq) ((rq)->cmd_type == REQ_TYPE_SENSE) 535 536 #define blk_noretry_request(rq) ((rq)->cmd_flags & REQ_FAILFAST) 537 #define blk_rq_started(rq) ((rq)->cmd_flags & REQ_STARTED) 538 539 #define blk_account_rq(rq) (blk_rq_started(rq) && blk_fs_request(rq)) 540 541 #define blk_pm_suspend_request(rq) ((rq)->cmd_type == REQ_TYPE_PM_SUSPEND) 542 #define blk_pm_resume_request(rq) ((rq)->cmd_type == REQ_TYPE_PM_RESUME) 543 #define blk_pm_request(rq) \ 544 (blk_pm_suspend_request(rq) || blk_pm_resume_request(rq)) 545 546 #define blk_sorted_rq(rq) ((rq)->cmd_flags & REQ_SORTED) 547 #define blk_barrier_rq(rq) ((rq)->cmd_flags & REQ_HARDBARRIER) 548 #define blk_fua_rq(rq) ((rq)->cmd_flags & REQ_FUA) 549 #define blk_bidi_rq(rq) ((rq)->next_rq != NULL) 550 #define blk_empty_barrier(rq) (blk_barrier_rq(rq) && blk_fs_request(rq) && !(rq)->hard_nr_sectors) 551 /* rq->queuelist of dequeued request must be list_empty() */ 552 #define blk_queued_rq(rq) (!list_empty(&(rq)->queuelist)) 553 554 #define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist) 555 556 #define rq_data_dir(rq) ((rq)->cmd_flags & 1) 557 558 /* 559 * We regard a request as sync, if it's a READ or a SYNC write. 560 */ 561 #define rq_is_sync(rq) (rq_data_dir((rq)) == READ || (rq)->cmd_flags & REQ_RW_SYNC) 562 #define rq_is_meta(rq) ((rq)->cmd_flags & REQ_RW_META) 563 564 static inline int blk_queue_full(struct request_queue *q, int rw) 565 { 566 if (rw == READ) 567 return test_bit(QUEUE_FLAG_READFULL, &q->queue_flags); 568 return test_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags); 569 } 570 571 static inline void blk_set_queue_full(struct request_queue *q, int rw) 572 { 573 if (rw == READ) 574 queue_flag_set(QUEUE_FLAG_READFULL, q); 575 else 576 queue_flag_set(QUEUE_FLAG_WRITEFULL, q); 577 } 578 579 static inline void blk_clear_queue_full(struct request_queue *q, int rw) 580 { 581 if (rw == READ) 582 queue_flag_clear(QUEUE_FLAG_READFULL, q); 583 else 584 queue_flag_clear(QUEUE_FLAG_WRITEFULL, q); 585 } 586 587 588 /* 589 * mergeable request must not have _NOMERGE or _BARRIER bit set, nor may 590 * it already be started by driver. 591 */ 592 #define RQ_NOMERGE_FLAGS \ 593 (REQ_NOMERGE | REQ_STARTED | REQ_HARDBARRIER | REQ_SOFTBARRIER) 594 #define rq_mergeable(rq) \ 595 (!((rq)->cmd_flags & RQ_NOMERGE_FLAGS) && blk_fs_request((rq))) 596 597 /* 598 * q->prep_rq_fn return values 599 */ 600 #define BLKPREP_OK 0 /* serve it */ 601 #define BLKPREP_KILL 1 /* fatal error, kill */ 602 #define BLKPREP_DEFER 2 /* leave on queue */ 603 604 extern unsigned long blk_max_low_pfn, blk_max_pfn; 605 606 /* 607 * standard bounce addresses: 608 * 609 * BLK_BOUNCE_HIGH : bounce all highmem pages 610 * BLK_BOUNCE_ANY : don't bounce anything 611 * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary 612 */ 613 614 #if BITS_PER_LONG == 32 615 #define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT) 616 #else 617 #define BLK_BOUNCE_HIGH -1ULL 618 #endif 619 #define BLK_BOUNCE_ANY (-1ULL) 620 #define BLK_BOUNCE_ISA (ISA_DMA_THRESHOLD) 621 622 /* 623 * default timeout for SG_IO if none specified 624 */ 625 #define BLK_DEFAULT_SG_TIMEOUT (60 * HZ) 626 627 #ifdef CONFIG_BOUNCE 628 extern int init_emergency_isa_pool(void); 629 extern void blk_queue_bounce(struct request_queue *q, struct bio **bio); 630 #else 631 static inline int init_emergency_isa_pool(void) 632 { 633 return 0; 634 } 635 static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio) 636 { 637 } 638 #endif /* CONFIG_MMU */ 639 640 struct req_iterator { 641 int i; 642 struct bio *bio; 643 }; 644 645 /* This should not be used directly - use rq_for_each_segment */ 646 #define __rq_for_each_bio(_bio, rq) \ 647 if ((rq->bio)) \ 648 for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next) 649 650 #define rq_for_each_segment(bvl, _rq, _iter) \ 651 __rq_for_each_bio(_iter.bio, _rq) \ 652 bio_for_each_segment(bvl, _iter.bio, _iter.i) 653 654 #define rq_iter_last(rq, _iter) \ 655 (_iter.bio->bi_next == NULL && _iter.i == _iter.bio->bi_vcnt-1) 656 657 extern int blk_register_queue(struct gendisk *disk); 658 extern void blk_unregister_queue(struct gendisk *disk); 659 extern void register_disk(struct gendisk *dev); 660 extern void generic_make_request(struct bio *bio); 661 extern void blk_rq_init(struct request_queue *q, struct request *rq); 662 extern void blk_put_request(struct request *); 663 extern void __blk_put_request(struct request_queue *, struct request *); 664 extern struct request *blk_get_request(struct request_queue *, int, gfp_t); 665 extern void blk_insert_request(struct request_queue *, struct request *, int, void *); 666 extern void blk_requeue_request(struct request_queue *, struct request *); 667 extern void blk_plug_device(struct request_queue *); 668 extern void blk_plug_device_unlocked(struct request_queue *); 669 extern int blk_remove_plug(struct request_queue *); 670 extern void blk_recount_segments(struct request_queue *, struct bio *); 671 extern int scsi_cmd_ioctl(struct file *, struct request_queue *, 672 struct gendisk *, unsigned int, void __user *); 673 extern int sg_scsi_ioctl(struct file *, struct request_queue *, 674 struct gendisk *, struct scsi_ioctl_command __user *); 675 676 /* 677 * Temporary export, until SCSI gets fixed up. 678 */ 679 extern int blk_rq_append_bio(struct request_queue *q, struct request *rq, 680 struct bio *bio); 681 682 /* 683 * A queue has just exitted congestion. Note this in the global counter of 684 * congested queues, and wake up anyone who was waiting for requests to be 685 * put back. 686 */ 687 static inline void blk_clear_queue_congested(struct request_queue *q, int rw) 688 { 689 clear_bdi_congested(&q->backing_dev_info, rw); 690 } 691 692 /* 693 * A queue has just entered congestion. Flag that in the queue's VM-visible 694 * state flags and increment the global gounter of congested queues. 695 */ 696 static inline void blk_set_queue_congested(struct request_queue *q, int rw) 697 { 698 set_bdi_congested(&q->backing_dev_info, rw); 699 } 700 701 extern void blk_start_queue(struct request_queue *q); 702 extern void blk_stop_queue(struct request_queue *q); 703 extern void blk_sync_queue(struct request_queue *q); 704 extern void __blk_stop_queue(struct request_queue *q); 705 extern void __blk_run_queue(struct request_queue *); 706 extern void blk_run_queue(struct request_queue *); 707 extern void blk_start_queueing(struct request_queue *); 708 extern int blk_rq_map_user(struct request_queue *, struct request *, void __user *, unsigned long); 709 extern int blk_rq_unmap_user(struct bio *); 710 extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, unsigned int, gfp_t); 711 extern int blk_rq_map_user_iov(struct request_queue *, struct request *, 712 struct sg_iovec *, int, unsigned int); 713 extern int blk_execute_rq(struct request_queue *, struct gendisk *, 714 struct request *, int); 715 extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *, 716 struct request *, int, rq_end_io_fn *); 717 extern void blk_unplug(struct request_queue *q); 718 719 static inline struct request_queue *bdev_get_queue(struct block_device *bdev) 720 { 721 return bdev->bd_disk->queue; 722 } 723 724 static inline void blk_run_backing_dev(struct backing_dev_info *bdi, 725 struct page *page) 726 { 727 if (bdi && bdi->unplug_io_fn) 728 bdi->unplug_io_fn(bdi, page); 729 } 730 731 static inline void blk_run_address_space(struct address_space *mapping) 732 { 733 if (mapping) 734 blk_run_backing_dev(mapping->backing_dev_info, NULL); 735 } 736 737 /* 738 * blk_end_request() and friends. 739 * __blk_end_request() and end_request() must be called with 740 * the request queue spinlock acquired. 741 * 742 * Several drivers define their own end_request and call 743 * blk_end_request() for parts of the original function. 744 * This prevents code duplication in drivers. 745 */ 746 extern int blk_end_request(struct request *rq, int error, 747 unsigned int nr_bytes); 748 extern int __blk_end_request(struct request *rq, int error, 749 unsigned int nr_bytes); 750 extern int blk_end_bidi_request(struct request *rq, int error, 751 unsigned int nr_bytes, unsigned int bidi_bytes); 752 extern void end_request(struct request *, int); 753 extern void end_queued_request(struct request *, int); 754 extern void end_dequeued_request(struct request *, int); 755 extern int blk_end_request_callback(struct request *rq, int error, 756 unsigned int nr_bytes, 757 int (drv_callback)(struct request *)); 758 extern void blk_complete_request(struct request *); 759 760 /* 761 * blk_end_request() takes bytes instead of sectors as a complete size. 762 * blk_rq_bytes() returns bytes left to complete in the entire request. 763 * blk_rq_cur_bytes() returns bytes left to complete in the current segment. 764 */ 765 extern unsigned int blk_rq_bytes(struct request *rq); 766 extern unsigned int blk_rq_cur_bytes(struct request *rq); 767 768 static inline void blkdev_dequeue_request(struct request *req) 769 { 770 elv_dequeue_request(req->q, req); 771 } 772 773 /* 774 * Access functions for manipulating queue properties 775 */ 776 extern struct request_queue *blk_init_queue_node(request_fn_proc *rfn, 777 spinlock_t *lock, int node_id); 778 extern struct request_queue *blk_init_queue(request_fn_proc *, spinlock_t *); 779 extern void blk_cleanup_queue(struct request_queue *); 780 extern void blk_queue_make_request(struct request_queue *, make_request_fn *); 781 extern void blk_queue_bounce_limit(struct request_queue *, u64); 782 extern void blk_queue_max_sectors(struct request_queue *, unsigned int); 783 extern void blk_queue_max_phys_segments(struct request_queue *, unsigned short); 784 extern void blk_queue_max_hw_segments(struct request_queue *, unsigned short); 785 extern void blk_queue_max_segment_size(struct request_queue *, unsigned int); 786 extern void blk_queue_hardsect_size(struct request_queue *, unsigned short); 787 extern void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b); 788 extern void blk_queue_dma_pad(struct request_queue *, unsigned int); 789 extern void blk_queue_update_dma_pad(struct request_queue *, unsigned int); 790 extern int blk_queue_dma_drain(struct request_queue *q, 791 dma_drain_needed_fn *dma_drain_needed, 792 void *buf, unsigned int size); 793 extern void blk_queue_segment_boundary(struct request_queue *, unsigned long); 794 extern void blk_queue_prep_rq(struct request_queue *, prep_rq_fn *pfn); 795 extern void blk_queue_merge_bvec(struct request_queue *, merge_bvec_fn *); 796 extern void blk_queue_dma_alignment(struct request_queue *, int); 797 extern void blk_queue_update_dma_alignment(struct request_queue *, int); 798 extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *); 799 extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev); 800 extern int blk_queue_ordered(struct request_queue *, unsigned, prepare_flush_fn *); 801 extern int blk_do_ordered(struct request_queue *, struct request **); 802 extern unsigned blk_ordered_cur_seq(struct request_queue *); 803 extern unsigned blk_ordered_req_seq(struct request *); 804 extern void blk_ordered_complete_seq(struct request_queue *, unsigned, int); 805 806 extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *); 807 extern void blk_dump_rq_flags(struct request *, char *); 808 extern void generic_unplug_device(struct request_queue *); 809 extern void __generic_unplug_device(struct request_queue *); 810 extern long nr_blockdev_pages(void); 811 812 int blk_get_queue(struct request_queue *); 813 struct request_queue *blk_alloc_queue(gfp_t); 814 struct request_queue *blk_alloc_queue_node(gfp_t, int); 815 extern void blk_put_queue(struct request_queue *); 816 817 /* 818 * tag stuff 819 */ 820 #define blk_rq_tagged(rq) ((rq)->cmd_flags & REQ_QUEUED) 821 extern int blk_queue_start_tag(struct request_queue *, struct request *); 822 extern struct request *blk_queue_find_tag(struct request_queue *, int); 823 extern void blk_queue_end_tag(struct request_queue *, struct request *); 824 extern int blk_queue_init_tags(struct request_queue *, int, struct blk_queue_tag *); 825 extern void blk_queue_free_tags(struct request_queue *); 826 extern int blk_queue_resize_tags(struct request_queue *, int); 827 extern void blk_queue_invalidate_tags(struct request_queue *); 828 extern struct blk_queue_tag *blk_init_tags(int); 829 extern void blk_free_tags(struct blk_queue_tag *); 830 831 static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt, 832 int tag) 833 { 834 if (unlikely(bqt == NULL || tag >= bqt->real_max_depth)) 835 return NULL; 836 return bqt->tag_index[tag]; 837 } 838 839 extern int blkdev_issue_flush(struct block_device *, sector_t *); 840 841 /* 842 * command filter functions 843 */ 844 extern int blk_verify_command(struct blk_cmd_filter *filter, 845 unsigned char *cmd, int has_write_perm); 846 extern int blk_register_filter(struct gendisk *disk); 847 extern void blk_unregister_filter(struct gendisk *disk); 848 extern void blk_set_cmd_filter_defaults(struct blk_cmd_filter *filter); 849 850 #define MAX_PHYS_SEGMENTS 128 851 #define MAX_HW_SEGMENTS 128 852 #define SAFE_MAX_SECTORS 255 853 #define BLK_DEF_MAX_SECTORS 1024 854 855 #define MAX_SEGMENT_SIZE 65536 856 857 #define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist) 858 859 static inline int queue_hardsect_size(struct request_queue *q) 860 { 861 int retval = 512; 862 863 if (q && q->hardsect_size) 864 retval = q->hardsect_size; 865 866 return retval; 867 } 868 869 static inline int bdev_hardsect_size(struct block_device *bdev) 870 { 871 return queue_hardsect_size(bdev_get_queue(bdev)); 872 } 873 874 static inline int queue_dma_alignment(struct request_queue *q) 875 { 876 return q ? q->dma_alignment : 511; 877 } 878 879 /* assumes size > 256 */ 880 static inline unsigned int blksize_bits(unsigned int size) 881 { 882 unsigned int bits = 8; 883 do { 884 bits++; 885 size >>= 1; 886 } while (size > 256); 887 return bits; 888 } 889 890 static inline unsigned int block_size(struct block_device *bdev) 891 { 892 return bdev->bd_block_size; 893 } 894 895 typedef struct {struct page *v;} Sector; 896 897 unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *); 898 899 static inline void put_dev_sector(Sector p) 900 { 901 page_cache_release(p.v); 902 } 903 904 struct work_struct; 905 int kblockd_schedule_work(struct work_struct *work); 906 void kblockd_flush_work(struct work_struct *work); 907 908 #define MODULE_ALIAS_BLOCKDEV(major,minor) \ 909 MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor)) 910 #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \ 911 MODULE_ALIAS("block-major-" __stringify(major) "-*") 912 913 #if defined(CONFIG_BLK_DEV_INTEGRITY) 914 915 #define INTEGRITY_FLAG_READ 2 /* verify data integrity on read */ 916 #define INTEGRITY_FLAG_WRITE 4 /* generate data integrity on write */ 917 918 struct blk_integrity_exchg { 919 void *prot_buf; 920 void *data_buf; 921 sector_t sector; 922 unsigned int data_size; 923 unsigned short sector_size; 924 const char *disk_name; 925 }; 926 927 typedef void (integrity_gen_fn) (struct blk_integrity_exchg *); 928 typedef int (integrity_vrfy_fn) (struct blk_integrity_exchg *); 929 typedef void (integrity_set_tag_fn) (void *, void *, unsigned int); 930 typedef void (integrity_get_tag_fn) (void *, void *, unsigned int); 931 932 struct blk_integrity { 933 integrity_gen_fn *generate_fn; 934 integrity_vrfy_fn *verify_fn; 935 integrity_set_tag_fn *set_tag_fn; 936 integrity_get_tag_fn *get_tag_fn; 937 938 unsigned short flags; 939 unsigned short tuple_size; 940 unsigned short sector_size; 941 unsigned short tag_size; 942 943 const char *name; 944 945 struct kobject kobj; 946 }; 947 948 extern int blk_integrity_register(struct gendisk *, struct blk_integrity *); 949 extern void blk_integrity_unregister(struct gendisk *); 950 extern int blk_integrity_compare(struct block_device *, struct block_device *); 951 extern int blk_rq_map_integrity_sg(struct request *, struct scatterlist *); 952 extern int blk_rq_count_integrity_sg(struct request *); 953 954 static inline unsigned short blk_integrity_tuple_size(struct blk_integrity *bi) 955 { 956 if (bi) 957 return bi->tuple_size; 958 959 return 0; 960 } 961 962 static inline struct blk_integrity *bdev_get_integrity(struct block_device *bdev) 963 { 964 return bdev->bd_disk->integrity; 965 } 966 967 static inline unsigned int bdev_get_tag_size(struct block_device *bdev) 968 { 969 struct blk_integrity *bi = bdev_get_integrity(bdev); 970 971 if (bi) 972 return bi->tag_size; 973 974 return 0; 975 } 976 977 static inline int bdev_integrity_enabled(struct block_device *bdev, int rw) 978 { 979 struct blk_integrity *bi = bdev_get_integrity(bdev); 980 981 if (bi == NULL) 982 return 0; 983 984 if (rw == READ && bi->verify_fn != NULL && 985 (bi->flags & INTEGRITY_FLAG_READ)) 986 return 1; 987 988 if (rw == WRITE && bi->generate_fn != NULL && 989 (bi->flags & INTEGRITY_FLAG_WRITE)) 990 return 1; 991 992 return 0; 993 } 994 995 static inline int blk_integrity_rq(struct request *rq) 996 { 997 if (rq->bio == NULL) 998 return 0; 999 1000 return bio_integrity(rq->bio); 1001 } 1002 1003 #else /* CONFIG_BLK_DEV_INTEGRITY */ 1004 1005 #define blk_integrity_rq(rq) (0) 1006 #define blk_rq_count_integrity_sg(a) (0) 1007 #define blk_rq_map_integrity_sg(a, b) (0) 1008 #define bdev_get_integrity(a) (0) 1009 #define bdev_get_tag_size(a) (0) 1010 #define blk_integrity_compare(a, b) (0) 1011 #define blk_integrity_register(a, b) (0) 1012 #define blk_integrity_unregister(a) do { } while (0); 1013 1014 #endif /* CONFIG_BLK_DEV_INTEGRITY */ 1015 1016 #else /* CONFIG_BLOCK */ 1017 /* 1018 * stubs for when the block layer is configured out 1019 */ 1020 #define buffer_heads_over_limit 0 1021 1022 static inline long nr_blockdev_pages(void) 1023 { 1024 return 0; 1025 } 1026 1027 #endif /* CONFIG_BLOCK */ 1028 1029 #endif 1030