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/gfp.h> 20 #include <linux/bsg.h> 21 #include <linux/smp.h> 22 23 #include <asm/scatterlist.h> 24 25 struct scsi_ioctl_command; 26 27 struct request_queue; 28 struct elevator_queue; 29 typedef struct elevator_queue elevator_t; 30 struct request_pm_state; 31 struct blk_trace; 32 struct request; 33 struct sg_io_hdr; 34 35 #define BLKDEV_MIN_RQ 4 36 #define BLKDEV_MAX_RQ 128 /* Default maximum */ 37 38 struct request; 39 typedef void (rq_end_io_fn)(struct request *, int); 40 41 struct request_list { 42 int count[2]; 43 int starved[2]; 44 int elvpriv; 45 mempool_t *rq_pool; 46 wait_queue_head_t wait[2]; 47 }; 48 49 /* 50 * request command types 51 */ 52 enum rq_cmd_type_bits { 53 REQ_TYPE_FS = 1, /* fs request */ 54 REQ_TYPE_BLOCK_PC, /* scsi command */ 55 REQ_TYPE_SENSE, /* sense request */ 56 REQ_TYPE_PM_SUSPEND, /* suspend request */ 57 REQ_TYPE_PM_RESUME, /* resume request */ 58 REQ_TYPE_PM_SHUTDOWN, /* shutdown request */ 59 REQ_TYPE_SPECIAL, /* driver defined type */ 60 REQ_TYPE_LINUX_BLOCK, /* generic block layer message */ 61 /* 62 * for ATA/ATAPI devices. this really doesn't belong here, ide should 63 * use REQ_TYPE_SPECIAL and use rq->cmd[0] with the range of driver 64 * private REQ_LB opcodes to differentiate what type of request this is 65 */ 66 REQ_TYPE_ATA_TASKFILE, 67 REQ_TYPE_ATA_PC, 68 }; 69 70 /* 71 * For request of type REQ_TYPE_LINUX_BLOCK, rq->cmd[0] is the opcode being 72 * sent down (similar to how REQ_TYPE_BLOCK_PC means that ->cmd[] holds a 73 * SCSI cdb. 74 * 75 * 0x00 -> 0x3f are driver private, to be used for whatever purpose they need, 76 * typically to differentiate REQ_TYPE_SPECIAL requests. 77 * 78 */ 79 enum { 80 REQ_LB_OP_EJECT = 0x40, /* eject request */ 81 REQ_LB_OP_FLUSH = 0x41, /* flush request */ 82 REQ_LB_OP_DISCARD = 0x42, /* discard sectors */ 83 }; 84 85 /* 86 * request type modified bits. first two bits match BIO_RW* bits, important 87 */ 88 enum rq_flag_bits { 89 __REQ_RW, /* not set, read. set, write */ 90 __REQ_FAILFAST, /* no low level driver retries */ 91 __REQ_DISCARD, /* request to discard sectors */ 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_DISCARD (1 << __REQ_DISCARD) 115 #define REQ_FAILFAST (1 << __REQ_FAILFAST) 116 #define REQ_SORTED (1 << __REQ_SORTED) 117 #define REQ_SOFTBARRIER (1 << __REQ_SOFTBARRIER) 118 #define REQ_HARDBARRIER (1 << __REQ_HARDBARRIER) 119 #define REQ_FUA (1 << __REQ_FUA) 120 #define REQ_NOMERGE (1 << __REQ_NOMERGE) 121 #define REQ_STARTED (1 << __REQ_STARTED) 122 #define REQ_DONTPREP (1 << __REQ_DONTPREP) 123 #define REQ_QUEUED (1 << __REQ_QUEUED) 124 #define REQ_ELVPRIV (1 << __REQ_ELVPRIV) 125 #define REQ_FAILED (1 << __REQ_FAILED) 126 #define REQ_QUIET (1 << __REQ_QUIET) 127 #define REQ_PREEMPT (1 << __REQ_PREEMPT) 128 #define REQ_ORDERED_COLOR (1 << __REQ_ORDERED_COLOR) 129 #define REQ_RW_SYNC (1 << __REQ_RW_SYNC) 130 #define REQ_ALLOCED (1 << __REQ_ALLOCED) 131 #define REQ_RW_META (1 << __REQ_RW_META) 132 #define REQ_COPY_USER (1 << __REQ_COPY_USER) 133 #define REQ_INTEGRITY (1 << __REQ_INTEGRITY) 134 135 #define BLK_MAX_CDB 16 136 137 /* 138 * try to put the fields that are referenced together in the same cacheline. 139 * if you modify this structure, be sure to check block/blk-core.c:rq_init() 140 * as well! 141 */ 142 struct request { 143 struct list_head queuelist; 144 struct call_single_data csd; 145 int cpu; 146 147 struct request_queue *q; 148 149 unsigned int cmd_flags; 150 enum rq_cmd_type_bits cmd_type; 151 unsigned long atomic_flags; 152 153 /* Maintain bio traversal state for part by part I/O submission. 154 * hard_* are block layer internals, no driver should touch them! 155 */ 156 157 sector_t sector; /* next sector to submit */ 158 sector_t hard_sector; /* next sector to complete */ 159 unsigned long nr_sectors; /* no. of sectors left to submit */ 160 unsigned long hard_nr_sectors; /* no. of sectors left to complete */ 161 /* no. of sectors left to submit in the current segment */ 162 unsigned int current_nr_sectors; 163 164 /* no. of sectors left to complete in the current segment */ 165 unsigned int hard_cur_sectors; 166 167 struct bio *bio; 168 struct bio *biotail; 169 170 struct hlist_node hash; /* merge hash */ 171 /* 172 * The rb_node is only used inside the io scheduler, requests 173 * are pruned when moved to the dispatch queue. So let the 174 * completion_data share space with the rb_node. 175 */ 176 union { 177 struct rb_node rb_node; /* sort/lookup */ 178 void *completion_data; 179 }; 180 181 /* 182 * two pointers are available for the IO schedulers, if they need 183 * more they have to dynamically allocate it. 184 */ 185 void *elevator_private; 186 void *elevator_private2; 187 188 struct gendisk *rq_disk; 189 unsigned long start_time; 190 191 /* Number of scatter-gather DMA addr+len pairs after 192 * physical address coalescing is performed. 193 */ 194 unsigned short nr_phys_segments; 195 196 unsigned short ioprio; 197 198 void *special; 199 char *buffer; 200 201 int tag; 202 int errors; 203 204 int ref_count; 205 206 /* 207 * when request is used as a packet command carrier 208 */ 209 unsigned short cmd_len; 210 unsigned char __cmd[BLK_MAX_CDB]; 211 unsigned char *cmd; 212 213 unsigned int data_len; 214 unsigned int extra_len; /* length of alignment and padding */ 215 unsigned int sense_len; 216 void *data; 217 void *sense; 218 219 unsigned long deadline; 220 struct list_head timeout_list; 221 unsigned int timeout; 222 int retries; 223 224 /* 225 * completion callback. 226 */ 227 rq_end_io_fn *end_io; 228 void *end_io_data; 229 230 /* for bidi */ 231 struct request *next_rq; 232 }; 233 234 static inline unsigned short req_get_ioprio(struct request *req) 235 { 236 return req->ioprio; 237 } 238 239 /* 240 * State information carried for REQ_TYPE_PM_SUSPEND and REQ_TYPE_PM_RESUME 241 * requests. Some step values could eventually be made generic. 242 */ 243 struct request_pm_state 244 { 245 /* PM state machine step value, currently driver specific */ 246 int pm_step; 247 /* requested PM state value (S1, S2, S3, S4, ...) */ 248 u32 pm_state; 249 void* data; /* for driver use */ 250 }; 251 252 #include <linux/elevator.h> 253 254 typedef void (request_fn_proc) (struct request_queue *q); 255 typedef int (make_request_fn) (struct request_queue *q, struct bio *bio); 256 typedef int (prep_rq_fn) (struct request_queue *, struct request *); 257 typedef void (unplug_fn) (struct request_queue *); 258 typedef int (prepare_discard_fn) (struct request_queue *, struct request *); 259 260 struct bio_vec; 261 struct bvec_merge_data { 262 struct block_device *bi_bdev; 263 sector_t bi_sector; 264 unsigned bi_size; 265 unsigned long bi_rw; 266 }; 267 typedef int (merge_bvec_fn) (struct request_queue *, struct bvec_merge_data *, 268 struct bio_vec *); 269 typedef void (prepare_flush_fn) (struct request_queue *, struct request *); 270 typedef void (softirq_done_fn)(struct request *); 271 typedef int (dma_drain_needed_fn)(struct request *); 272 typedef int (lld_busy_fn) (struct request_queue *q); 273 274 enum blk_eh_timer_return { 275 BLK_EH_NOT_HANDLED, 276 BLK_EH_HANDLED, 277 BLK_EH_RESET_TIMER, 278 }; 279 280 typedef enum blk_eh_timer_return (rq_timed_out_fn)(struct request *); 281 282 enum blk_queue_state { 283 Queue_down, 284 Queue_up, 285 }; 286 287 struct blk_queue_tag { 288 struct request **tag_index; /* map of busy tags */ 289 unsigned long *tag_map; /* bit map of free/busy tags */ 290 int busy; /* current depth */ 291 int max_depth; /* what we will send to device */ 292 int real_max_depth; /* what the array can hold */ 293 atomic_t refcnt; /* map can be shared */ 294 }; 295 296 #define BLK_SCSI_MAX_CMDS (256) 297 #define BLK_SCSI_CMD_PER_LONG (BLK_SCSI_MAX_CMDS / (sizeof(long) * 8)) 298 299 struct blk_cmd_filter { 300 unsigned long read_ok[BLK_SCSI_CMD_PER_LONG]; 301 unsigned long write_ok[BLK_SCSI_CMD_PER_LONG]; 302 struct kobject kobj; 303 }; 304 305 struct request_queue 306 { 307 /* 308 * Together with queue_head for cacheline sharing 309 */ 310 struct list_head queue_head; 311 struct request *last_merge; 312 elevator_t *elevator; 313 314 /* 315 * the queue request freelist, one for reads and one for writes 316 */ 317 struct request_list rq; 318 319 request_fn_proc *request_fn; 320 make_request_fn *make_request_fn; 321 prep_rq_fn *prep_rq_fn; 322 unplug_fn *unplug_fn; 323 prepare_discard_fn *prepare_discard_fn; 324 merge_bvec_fn *merge_bvec_fn; 325 prepare_flush_fn *prepare_flush_fn; 326 softirq_done_fn *softirq_done_fn; 327 rq_timed_out_fn *rq_timed_out_fn; 328 dma_drain_needed_fn *dma_drain_needed; 329 lld_busy_fn *lld_busy_fn; 330 331 /* 332 * Dispatch queue sorting 333 */ 334 sector_t end_sector; 335 struct request *boundary_rq; 336 337 /* 338 * Auto-unplugging state 339 */ 340 struct timer_list unplug_timer; 341 int unplug_thresh; /* After this many requests */ 342 unsigned long unplug_delay; /* After this many jiffies */ 343 struct work_struct unplug_work; 344 345 struct backing_dev_info backing_dev_info; 346 347 /* 348 * The queue owner gets to use this for whatever they like. 349 * ll_rw_blk doesn't touch it. 350 */ 351 void *queuedata; 352 353 /* 354 * queue needs bounce pages for pages above this limit 355 */ 356 unsigned long bounce_pfn; 357 gfp_t bounce_gfp; 358 359 /* 360 * various queue flags, see QUEUE_* below 361 */ 362 unsigned long queue_flags; 363 364 /* 365 * protects queue structures from reentrancy. ->__queue_lock should 366 * _never_ be used directly, it is queue private. always use 367 * ->queue_lock. 368 */ 369 spinlock_t __queue_lock; 370 spinlock_t *queue_lock; 371 372 /* 373 * queue kobject 374 */ 375 struct kobject kobj; 376 377 /* 378 * queue settings 379 */ 380 unsigned long nr_requests; /* Max # of requests */ 381 unsigned int nr_congestion_on; 382 unsigned int nr_congestion_off; 383 unsigned int nr_batching; 384 385 unsigned int max_sectors; 386 unsigned int max_hw_sectors; 387 unsigned short max_phys_segments; 388 unsigned short max_hw_segments; 389 unsigned short hardsect_size; 390 unsigned int max_segment_size; 391 392 unsigned long seg_boundary_mask; 393 void *dma_drain_buffer; 394 unsigned int dma_drain_size; 395 unsigned int dma_pad_mask; 396 unsigned int dma_alignment; 397 398 struct blk_queue_tag *queue_tags; 399 struct list_head tag_busy_list; 400 401 unsigned int nr_sorted; 402 unsigned int in_flight; 403 404 unsigned int rq_timeout; 405 struct timer_list timeout; 406 struct list_head timeout_list; 407 408 /* 409 * sg stuff 410 */ 411 unsigned int sg_timeout; 412 unsigned int sg_reserved_size; 413 int node; 414 #ifdef CONFIG_BLK_DEV_IO_TRACE 415 struct blk_trace *blk_trace; 416 #endif 417 /* 418 * reserved for flush operations 419 */ 420 unsigned int ordered, next_ordered, ordseq; 421 int orderr, ordcolor; 422 struct request pre_flush_rq, bar_rq, post_flush_rq; 423 struct request *orig_bar_rq; 424 425 struct mutex sysfs_lock; 426 427 #if defined(CONFIG_BLK_DEV_BSG) 428 struct bsg_class_device bsg_dev; 429 #endif 430 struct blk_cmd_filter cmd_filter; 431 }; 432 433 #define QUEUE_FLAG_CLUSTER 0 /* cluster several segments into 1 */ 434 #define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */ 435 #define QUEUE_FLAG_STOPPED 2 /* queue is stopped */ 436 #define QUEUE_FLAG_READFULL 3 /* read queue has been filled */ 437 #define QUEUE_FLAG_WRITEFULL 4 /* write queue has been filled */ 438 #define QUEUE_FLAG_DEAD 5 /* queue being torn down */ 439 #define QUEUE_FLAG_REENTER 6 /* Re-entrancy avoidance */ 440 #define QUEUE_FLAG_PLUGGED 7 /* queue is plugged */ 441 #define QUEUE_FLAG_ELVSWITCH 8 /* don't use elevator, just do FIFO */ 442 #define QUEUE_FLAG_BIDI 9 /* queue supports bidi requests */ 443 #define QUEUE_FLAG_NOMERGES 10 /* disable merge attempts */ 444 #define QUEUE_FLAG_SAME_COMP 11 /* force complete on same CPU */ 445 #define QUEUE_FLAG_FAIL_IO 12 /* fake timeout */ 446 #define QUEUE_FLAG_STACKABLE 13 /* supports request stacking */ 447 #define QUEUE_FLAG_NONROT 14 /* non-rotational device (SSD) */ 448 449 static inline int queue_is_locked(struct request_queue *q) 450 { 451 #ifdef CONFIG_SMP 452 spinlock_t *lock = q->queue_lock; 453 return lock && spin_is_locked(lock); 454 #else 455 return 1; 456 #endif 457 } 458 459 static inline void queue_flag_set_unlocked(unsigned int flag, 460 struct request_queue *q) 461 { 462 __set_bit(flag, &q->queue_flags); 463 } 464 465 static inline int queue_flag_test_and_clear(unsigned int flag, 466 struct request_queue *q) 467 { 468 WARN_ON_ONCE(!queue_is_locked(q)); 469 470 if (test_bit(flag, &q->queue_flags)) { 471 __clear_bit(flag, &q->queue_flags); 472 return 1; 473 } 474 475 return 0; 476 } 477 478 static inline int queue_flag_test_and_set(unsigned int flag, 479 struct request_queue *q) 480 { 481 WARN_ON_ONCE(!queue_is_locked(q)); 482 483 if (!test_bit(flag, &q->queue_flags)) { 484 __set_bit(flag, &q->queue_flags); 485 return 0; 486 } 487 488 return 1; 489 } 490 491 static inline void queue_flag_set(unsigned int flag, struct request_queue *q) 492 { 493 WARN_ON_ONCE(!queue_is_locked(q)); 494 __set_bit(flag, &q->queue_flags); 495 } 496 497 static inline void queue_flag_clear_unlocked(unsigned int flag, 498 struct request_queue *q) 499 { 500 __clear_bit(flag, &q->queue_flags); 501 } 502 503 static inline void queue_flag_clear(unsigned int flag, struct request_queue *q) 504 { 505 WARN_ON_ONCE(!queue_is_locked(q)); 506 __clear_bit(flag, &q->queue_flags); 507 } 508 509 enum { 510 /* 511 * Hardbarrier is supported with one of the following methods. 512 * 513 * NONE : hardbarrier unsupported 514 * DRAIN : ordering by draining is enough 515 * DRAIN_FLUSH : ordering by draining w/ pre and post flushes 516 * DRAIN_FUA : ordering by draining w/ pre flush and FUA write 517 * TAG : ordering by tag is enough 518 * TAG_FLUSH : ordering by tag w/ pre and post flushes 519 * TAG_FUA : ordering by tag w/ pre flush and FUA write 520 */ 521 QUEUE_ORDERED_NONE = 0x00, 522 QUEUE_ORDERED_DRAIN = 0x01, 523 QUEUE_ORDERED_TAG = 0x02, 524 525 QUEUE_ORDERED_PREFLUSH = 0x10, 526 QUEUE_ORDERED_POSTFLUSH = 0x20, 527 QUEUE_ORDERED_FUA = 0x40, 528 529 QUEUE_ORDERED_DRAIN_FLUSH = QUEUE_ORDERED_DRAIN | 530 QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_POSTFLUSH, 531 QUEUE_ORDERED_DRAIN_FUA = QUEUE_ORDERED_DRAIN | 532 QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_FUA, 533 QUEUE_ORDERED_TAG_FLUSH = QUEUE_ORDERED_TAG | 534 QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_POSTFLUSH, 535 QUEUE_ORDERED_TAG_FUA = QUEUE_ORDERED_TAG | 536 QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_FUA, 537 538 /* 539 * Ordered operation sequence 540 */ 541 QUEUE_ORDSEQ_STARTED = 0x01, /* flushing in progress */ 542 QUEUE_ORDSEQ_DRAIN = 0x02, /* waiting for the queue to be drained */ 543 QUEUE_ORDSEQ_PREFLUSH = 0x04, /* pre-flushing in progress */ 544 QUEUE_ORDSEQ_BAR = 0x08, /* original barrier req in progress */ 545 QUEUE_ORDSEQ_POSTFLUSH = 0x10, /* post-flushing in progress */ 546 QUEUE_ORDSEQ_DONE = 0x20, 547 }; 548 549 #define blk_queue_plugged(q) test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags) 550 #define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags) 551 #define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags) 552 #define blk_queue_nomerges(q) test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags) 553 #define blk_queue_nonrot(q) test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags) 554 #define blk_queue_flushing(q) ((q)->ordseq) 555 #define blk_queue_stackable(q) \ 556 test_bit(QUEUE_FLAG_STACKABLE, &(q)->queue_flags) 557 558 #define blk_fs_request(rq) ((rq)->cmd_type == REQ_TYPE_FS) 559 #define blk_pc_request(rq) ((rq)->cmd_type == REQ_TYPE_BLOCK_PC) 560 #define blk_special_request(rq) ((rq)->cmd_type == REQ_TYPE_SPECIAL) 561 #define blk_sense_request(rq) ((rq)->cmd_type == REQ_TYPE_SENSE) 562 563 #define blk_noretry_request(rq) ((rq)->cmd_flags & REQ_FAILFAST) 564 #define blk_rq_started(rq) ((rq)->cmd_flags & REQ_STARTED) 565 566 #define blk_account_rq(rq) (blk_rq_started(rq) && (blk_fs_request(rq) || blk_discard_rq(rq))) 567 568 #define blk_pm_suspend_request(rq) ((rq)->cmd_type == REQ_TYPE_PM_SUSPEND) 569 #define blk_pm_resume_request(rq) ((rq)->cmd_type == REQ_TYPE_PM_RESUME) 570 #define blk_pm_request(rq) \ 571 (blk_pm_suspend_request(rq) || blk_pm_resume_request(rq)) 572 573 #define blk_rq_cpu_valid(rq) ((rq)->cpu != -1) 574 #define blk_sorted_rq(rq) ((rq)->cmd_flags & REQ_SORTED) 575 #define blk_barrier_rq(rq) ((rq)->cmd_flags & REQ_HARDBARRIER) 576 #define blk_fua_rq(rq) ((rq)->cmd_flags & REQ_FUA) 577 #define blk_discard_rq(rq) ((rq)->cmd_flags & REQ_DISCARD) 578 #define blk_bidi_rq(rq) ((rq)->next_rq != NULL) 579 #define blk_empty_barrier(rq) (blk_barrier_rq(rq) && blk_fs_request(rq) && !(rq)->hard_nr_sectors) 580 /* rq->queuelist of dequeued request must be list_empty() */ 581 #define blk_queued_rq(rq) (!list_empty(&(rq)->queuelist)) 582 583 #define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist) 584 585 #define rq_data_dir(rq) ((rq)->cmd_flags & 1) 586 587 /* 588 * We regard a request as sync, if it's a READ or a SYNC write. 589 */ 590 #define rq_is_sync(rq) (rq_data_dir((rq)) == READ || (rq)->cmd_flags & REQ_RW_SYNC) 591 #define rq_is_meta(rq) ((rq)->cmd_flags & REQ_RW_META) 592 593 static inline int blk_queue_full(struct request_queue *q, int rw) 594 { 595 if (rw == READ) 596 return test_bit(QUEUE_FLAG_READFULL, &q->queue_flags); 597 return test_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags); 598 } 599 600 static inline void blk_set_queue_full(struct request_queue *q, int rw) 601 { 602 if (rw == READ) 603 queue_flag_set(QUEUE_FLAG_READFULL, q); 604 else 605 queue_flag_set(QUEUE_FLAG_WRITEFULL, q); 606 } 607 608 static inline void blk_clear_queue_full(struct request_queue *q, int rw) 609 { 610 if (rw == READ) 611 queue_flag_clear(QUEUE_FLAG_READFULL, q); 612 else 613 queue_flag_clear(QUEUE_FLAG_WRITEFULL, q); 614 } 615 616 617 /* 618 * mergeable request must not have _NOMERGE or _BARRIER bit set, nor may 619 * it already be started by driver. 620 */ 621 #define RQ_NOMERGE_FLAGS \ 622 (REQ_NOMERGE | REQ_STARTED | REQ_HARDBARRIER | REQ_SOFTBARRIER) 623 #define rq_mergeable(rq) \ 624 (!((rq)->cmd_flags & RQ_NOMERGE_FLAGS) && \ 625 (blk_discard_rq(rq) || blk_fs_request((rq)))) 626 627 /* 628 * q->prep_rq_fn return values 629 */ 630 #define BLKPREP_OK 0 /* serve it */ 631 #define BLKPREP_KILL 1 /* fatal error, kill */ 632 #define BLKPREP_DEFER 2 /* leave on queue */ 633 634 extern unsigned long blk_max_low_pfn, blk_max_pfn; 635 636 /* 637 * standard bounce addresses: 638 * 639 * BLK_BOUNCE_HIGH : bounce all highmem pages 640 * BLK_BOUNCE_ANY : don't bounce anything 641 * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary 642 */ 643 644 #if BITS_PER_LONG == 32 645 #define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT) 646 #else 647 #define BLK_BOUNCE_HIGH -1ULL 648 #endif 649 #define BLK_BOUNCE_ANY (-1ULL) 650 #define BLK_BOUNCE_ISA (ISA_DMA_THRESHOLD) 651 652 /* 653 * default timeout for SG_IO if none specified 654 */ 655 #define BLK_DEFAULT_SG_TIMEOUT (60 * HZ) 656 657 #ifdef CONFIG_BOUNCE 658 extern int init_emergency_isa_pool(void); 659 extern void blk_queue_bounce(struct request_queue *q, struct bio **bio); 660 #else 661 static inline int init_emergency_isa_pool(void) 662 { 663 return 0; 664 } 665 static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio) 666 { 667 } 668 #endif /* CONFIG_MMU */ 669 670 struct rq_map_data { 671 struct page **pages; 672 int page_order; 673 int nr_entries; 674 }; 675 676 struct req_iterator { 677 int i; 678 struct bio *bio; 679 }; 680 681 /* This should not be used directly - use rq_for_each_segment */ 682 #define __rq_for_each_bio(_bio, rq) \ 683 if ((rq->bio)) \ 684 for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next) 685 686 #define rq_for_each_segment(bvl, _rq, _iter) \ 687 __rq_for_each_bio(_iter.bio, _rq) \ 688 bio_for_each_segment(bvl, _iter.bio, _iter.i) 689 690 #define rq_iter_last(rq, _iter) \ 691 (_iter.bio->bi_next == NULL && _iter.i == _iter.bio->bi_vcnt-1) 692 693 extern int blk_register_queue(struct gendisk *disk); 694 extern void blk_unregister_queue(struct gendisk *disk); 695 extern void register_disk(struct gendisk *dev); 696 extern void generic_make_request(struct bio *bio); 697 extern void blk_rq_init(struct request_queue *q, struct request *rq); 698 extern void blk_put_request(struct request *); 699 extern void __blk_put_request(struct request_queue *, struct request *); 700 extern struct request *blk_get_request(struct request_queue *, int, gfp_t); 701 extern void blk_insert_request(struct request_queue *, struct request *, int, void *); 702 extern void blk_requeue_request(struct request_queue *, struct request *); 703 extern int blk_rq_check_limits(struct request_queue *q, struct request *rq); 704 extern int blk_lld_busy(struct request_queue *q); 705 extern int blk_insert_cloned_request(struct request_queue *q, 706 struct request *rq); 707 extern void blk_plug_device(struct request_queue *); 708 extern void blk_plug_device_unlocked(struct request_queue *); 709 extern int blk_remove_plug(struct request_queue *); 710 extern void blk_recount_segments(struct request_queue *, struct bio *); 711 extern int scsi_cmd_ioctl(struct file *, struct request_queue *, 712 struct gendisk *, unsigned int, void __user *); 713 extern int sg_scsi_ioctl(struct file *, struct request_queue *, 714 struct gendisk *, struct scsi_ioctl_command __user *); 715 716 /* 717 * Temporary export, until SCSI gets fixed up. 718 */ 719 extern int blk_rq_append_bio(struct request_queue *q, struct request *rq, 720 struct bio *bio); 721 722 /* 723 * A queue has just exitted congestion. Note this in the global counter of 724 * congested queues, and wake up anyone who was waiting for requests to be 725 * put back. 726 */ 727 static inline void blk_clear_queue_congested(struct request_queue *q, int rw) 728 { 729 clear_bdi_congested(&q->backing_dev_info, rw); 730 } 731 732 /* 733 * A queue has just entered congestion. Flag that in the queue's VM-visible 734 * state flags and increment the global gounter of congested queues. 735 */ 736 static inline void blk_set_queue_congested(struct request_queue *q, int rw) 737 { 738 set_bdi_congested(&q->backing_dev_info, rw); 739 } 740 741 extern void blk_start_queue(struct request_queue *q); 742 extern void blk_stop_queue(struct request_queue *q); 743 extern void blk_sync_queue(struct request_queue *q); 744 extern void __blk_stop_queue(struct request_queue *q); 745 extern void __blk_run_queue(struct request_queue *); 746 extern void blk_run_queue(struct request_queue *); 747 extern void blk_start_queueing(struct request_queue *); 748 extern int blk_rq_map_user(struct request_queue *, struct request *, 749 struct rq_map_data *, void __user *, unsigned long, 750 gfp_t); 751 extern int blk_rq_unmap_user(struct bio *); 752 extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, unsigned int, gfp_t); 753 extern int blk_rq_map_user_iov(struct request_queue *, struct request *, 754 struct rq_map_data *, struct sg_iovec *, int, 755 unsigned int, gfp_t); 756 extern int blk_execute_rq(struct request_queue *, struct gendisk *, 757 struct request *, int); 758 extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *, 759 struct request *, int, rq_end_io_fn *); 760 extern void blk_unplug(struct request_queue *q); 761 762 static inline struct request_queue *bdev_get_queue(struct block_device *bdev) 763 { 764 return bdev->bd_disk->queue; 765 } 766 767 static inline void blk_run_backing_dev(struct backing_dev_info *bdi, 768 struct page *page) 769 { 770 if (bdi && bdi->unplug_io_fn) 771 bdi->unplug_io_fn(bdi, page); 772 } 773 774 static inline void blk_run_address_space(struct address_space *mapping) 775 { 776 if (mapping) 777 blk_run_backing_dev(mapping->backing_dev_info, NULL); 778 } 779 780 /* 781 * blk_end_request() and friends. 782 * __blk_end_request() and end_request() must be called with 783 * the request queue spinlock acquired. 784 * 785 * Several drivers define their own end_request and call 786 * blk_end_request() for parts of the original function. 787 * This prevents code duplication in drivers. 788 */ 789 extern int blk_end_request(struct request *rq, int error, 790 unsigned int nr_bytes); 791 extern int __blk_end_request(struct request *rq, int error, 792 unsigned int nr_bytes); 793 extern int blk_end_bidi_request(struct request *rq, int error, 794 unsigned int nr_bytes, unsigned int bidi_bytes); 795 extern void end_request(struct request *, int); 796 extern int blk_end_request_callback(struct request *rq, int error, 797 unsigned int nr_bytes, 798 int (drv_callback)(struct request *)); 799 extern void blk_complete_request(struct request *); 800 extern void __blk_complete_request(struct request *); 801 extern void blk_abort_request(struct request *); 802 extern void blk_abort_queue(struct request_queue *); 803 extern void blk_update_request(struct request *rq, int error, 804 unsigned int nr_bytes); 805 806 /* 807 * blk_end_request() takes bytes instead of sectors as a complete size. 808 * blk_rq_bytes() returns bytes left to complete in the entire request. 809 * blk_rq_cur_bytes() returns bytes left to complete in the current segment. 810 */ 811 extern unsigned int blk_rq_bytes(struct request *rq); 812 extern unsigned int blk_rq_cur_bytes(struct request *rq); 813 814 static inline void blkdev_dequeue_request(struct request *req) 815 { 816 elv_dequeue_request(req->q, req); 817 } 818 819 /* 820 * Access functions for manipulating queue properties 821 */ 822 extern struct request_queue *blk_init_queue_node(request_fn_proc *rfn, 823 spinlock_t *lock, int node_id); 824 extern struct request_queue *blk_init_queue(request_fn_proc *, spinlock_t *); 825 extern void blk_cleanup_queue(struct request_queue *); 826 extern void blk_queue_make_request(struct request_queue *, make_request_fn *); 827 extern void blk_queue_bounce_limit(struct request_queue *, u64); 828 extern void blk_queue_max_sectors(struct request_queue *, unsigned int); 829 extern void blk_queue_max_phys_segments(struct request_queue *, unsigned short); 830 extern void blk_queue_max_hw_segments(struct request_queue *, unsigned short); 831 extern void blk_queue_max_segment_size(struct request_queue *, unsigned int); 832 extern void blk_queue_hardsect_size(struct request_queue *, unsigned short); 833 extern void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b); 834 extern void blk_queue_dma_pad(struct request_queue *, unsigned int); 835 extern void blk_queue_update_dma_pad(struct request_queue *, unsigned int); 836 extern int blk_queue_dma_drain(struct request_queue *q, 837 dma_drain_needed_fn *dma_drain_needed, 838 void *buf, unsigned int size); 839 extern void blk_queue_lld_busy(struct request_queue *q, lld_busy_fn *fn); 840 extern void blk_queue_segment_boundary(struct request_queue *, unsigned long); 841 extern void blk_queue_prep_rq(struct request_queue *, prep_rq_fn *pfn); 842 extern void blk_queue_merge_bvec(struct request_queue *, merge_bvec_fn *); 843 extern void blk_queue_dma_alignment(struct request_queue *, int); 844 extern void blk_queue_update_dma_alignment(struct request_queue *, int); 845 extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *); 846 extern void blk_queue_set_discard(struct request_queue *, prepare_discard_fn *); 847 extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *); 848 extern void blk_queue_rq_timeout(struct request_queue *, unsigned int); 849 extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev); 850 extern int blk_queue_ordered(struct request_queue *, unsigned, prepare_flush_fn *); 851 extern int blk_do_ordered(struct request_queue *, struct request **); 852 extern unsigned blk_ordered_cur_seq(struct request_queue *); 853 extern unsigned blk_ordered_req_seq(struct request *); 854 extern void blk_ordered_complete_seq(struct request_queue *, unsigned, int); 855 856 extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *); 857 extern void blk_dump_rq_flags(struct request *, char *); 858 extern void generic_unplug_device(struct request_queue *); 859 extern void __generic_unplug_device(struct request_queue *); 860 extern long nr_blockdev_pages(void); 861 862 int blk_get_queue(struct request_queue *); 863 struct request_queue *blk_alloc_queue(gfp_t); 864 struct request_queue *blk_alloc_queue_node(gfp_t, int); 865 extern void blk_put_queue(struct request_queue *); 866 867 /* 868 * tag stuff 869 */ 870 #define blk_rq_tagged(rq) ((rq)->cmd_flags & REQ_QUEUED) 871 extern int blk_queue_start_tag(struct request_queue *, struct request *); 872 extern struct request *blk_queue_find_tag(struct request_queue *, int); 873 extern void blk_queue_end_tag(struct request_queue *, struct request *); 874 extern int blk_queue_init_tags(struct request_queue *, int, struct blk_queue_tag *); 875 extern void blk_queue_free_tags(struct request_queue *); 876 extern int blk_queue_resize_tags(struct request_queue *, int); 877 extern void blk_queue_invalidate_tags(struct request_queue *); 878 extern struct blk_queue_tag *blk_init_tags(int); 879 extern void blk_free_tags(struct blk_queue_tag *); 880 881 static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt, 882 int tag) 883 { 884 if (unlikely(bqt == NULL || tag >= bqt->real_max_depth)) 885 return NULL; 886 return bqt->tag_index[tag]; 887 } 888 889 extern int blkdev_issue_flush(struct block_device *, sector_t *); 890 extern int blkdev_issue_discard(struct block_device *, 891 sector_t sector, sector_t nr_sects, gfp_t); 892 893 static inline int sb_issue_discard(struct super_block *sb, 894 sector_t block, sector_t nr_blocks) 895 { 896 block <<= (sb->s_blocksize_bits - 9); 897 nr_blocks <<= (sb->s_blocksize_bits - 9); 898 return blkdev_issue_discard(sb->s_bdev, block, nr_blocks, GFP_KERNEL); 899 } 900 901 /* 902 * command filter functions 903 */ 904 extern int blk_verify_command(struct blk_cmd_filter *filter, 905 unsigned char *cmd, int has_write_perm); 906 extern void blk_set_cmd_filter_defaults(struct blk_cmd_filter *filter); 907 908 #define MAX_PHYS_SEGMENTS 128 909 #define MAX_HW_SEGMENTS 128 910 #define SAFE_MAX_SECTORS 255 911 #define BLK_DEF_MAX_SECTORS 1024 912 913 #define MAX_SEGMENT_SIZE 65536 914 915 #define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist) 916 917 static inline int queue_hardsect_size(struct request_queue *q) 918 { 919 int retval = 512; 920 921 if (q && q->hardsect_size) 922 retval = q->hardsect_size; 923 924 return retval; 925 } 926 927 static inline int bdev_hardsect_size(struct block_device *bdev) 928 { 929 return queue_hardsect_size(bdev_get_queue(bdev)); 930 } 931 932 static inline int queue_dma_alignment(struct request_queue *q) 933 { 934 return q ? q->dma_alignment : 511; 935 } 936 937 static inline int blk_rq_aligned(struct request_queue *q, void *addr, 938 unsigned int len) 939 { 940 unsigned int alignment = queue_dma_alignment(q) | q->dma_pad_mask; 941 return !((unsigned long)addr & alignment) && !(len & alignment); 942 } 943 944 /* assumes size > 256 */ 945 static inline unsigned int blksize_bits(unsigned int size) 946 { 947 unsigned int bits = 8; 948 do { 949 bits++; 950 size >>= 1; 951 } while (size > 256); 952 return bits; 953 } 954 955 static inline unsigned int block_size(struct block_device *bdev) 956 { 957 return bdev->bd_block_size; 958 } 959 960 typedef struct {struct page *v;} Sector; 961 962 unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *); 963 964 static inline void put_dev_sector(Sector p) 965 { 966 page_cache_release(p.v); 967 } 968 969 struct work_struct; 970 int kblockd_schedule_work(struct request_queue *q, struct work_struct *work); 971 void kblockd_flush_work(struct work_struct *work); 972 973 #define MODULE_ALIAS_BLOCKDEV(major,minor) \ 974 MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor)) 975 #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \ 976 MODULE_ALIAS("block-major-" __stringify(major) "-*") 977 978 #if defined(CONFIG_BLK_DEV_INTEGRITY) 979 980 #define INTEGRITY_FLAG_READ 2 /* verify data integrity on read */ 981 #define INTEGRITY_FLAG_WRITE 4 /* generate data integrity on write */ 982 983 struct blk_integrity_exchg { 984 void *prot_buf; 985 void *data_buf; 986 sector_t sector; 987 unsigned int data_size; 988 unsigned short sector_size; 989 const char *disk_name; 990 }; 991 992 typedef void (integrity_gen_fn) (struct blk_integrity_exchg *); 993 typedef int (integrity_vrfy_fn) (struct blk_integrity_exchg *); 994 typedef void (integrity_set_tag_fn) (void *, void *, unsigned int); 995 typedef void (integrity_get_tag_fn) (void *, void *, unsigned int); 996 997 struct blk_integrity { 998 integrity_gen_fn *generate_fn; 999 integrity_vrfy_fn *verify_fn; 1000 integrity_set_tag_fn *set_tag_fn; 1001 integrity_get_tag_fn *get_tag_fn; 1002 1003 unsigned short flags; 1004 unsigned short tuple_size; 1005 unsigned short sector_size; 1006 unsigned short tag_size; 1007 1008 const char *name; 1009 1010 struct kobject kobj; 1011 }; 1012 1013 extern int blk_integrity_register(struct gendisk *, struct blk_integrity *); 1014 extern void blk_integrity_unregister(struct gendisk *); 1015 extern int blk_integrity_compare(struct gendisk *, struct gendisk *); 1016 extern int blk_rq_map_integrity_sg(struct request *, struct scatterlist *); 1017 extern int blk_rq_count_integrity_sg(struct request *); 1018 1019 static inline 1020 struct blk_integrity *bdev_get_integrity(struct block_device *bdev) 1021 { 1022 return bdev->bd_disk->integrity; 1023 } 1024 1025 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk) 1026 { 1027 return disk->integrity; 1028 } 1029 1030 static inline int blk_integrity_rq(struct request *rq) 1031 { 1032 if (rq->bio == NULL) 1033 return 0; 1034 1035 return bio_integrity(rq->bio); 1036 } 1037 1038 #else /* CONFIG_BLK_DEV_INTEGRITY */ 1039 1040 #define blk_integrity_rq(rq) (0) 1041 #define blk_rq_count_integrity_sg(a) (0) 1042 #define blk_rq_map_integrity_sg(a, b) (0) 1043 #define bdev_get_integrity(a) (0) 1044 #define blk_get_integrity(a) (0) 1045 #define blk_integrity_compare(a, b) (0) 1046 #define blk_integrity_register(a, b) (0) 1047 #define blk_integrity_unregister(a) do { } while (0); 1048 1049 #endif /* CONFIG_BLK_DEV_INTEGRITY */ 1050 1051 #else /* CONFIG_BLOCK */ 1052 /* 1053 * stubs for when the block layer is configured out 1054 */ 1055 #define buffer_heads_over_limit 0 1056 1057 static inline long nr_blockdev_pages(void) 1058 { 1059 return 0; 1060 } 1061 1062 #endif /* CONFIG_BLOCK */ 1063 1064 #endif 1065