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_DEV, /* no driver retries of device errors */ 91 __REQ_FAILFAST_TRANSPORT, /* no driver retries of transport errors */ 92 __REQ_FAILFAST_DRIVER, /* no driver retries of driver errors */ 93 __REQ_DISCARD, /* request to discard sectors */ 94 __REQ_SORTED, /* elevator knows about this request */ 95 __REQ_SOFTBARRIER, /* may not be passed by ioscheduler */ 96 __REQ_HARDBARRIER, /* may not be passed by drive either */ 97 __REQ_FUA, /* forced unit access */ 98 __REQ_NOMERGE, /* don't touch this for merging */ 99 __REQ_STARTED, /* drive already may have started this one */ 100 __REQ_DONTPREP, /* don't call prep for this one */ 101 __REQ_QUEUED, /* uses queueing */ 102 __REQ_ELVPRIV, /* elevator private data attached */ 103 __REQ_FAILED, /* set if the request failed */ 104 __REQ_QUIET, /* don't worry about errors */ 105 __REQ_PREEMPT, /* set for "ide_preempt" requests */ 106 __REQ_ORDERED_COLOR, /* is before or after barrier */ 107 __REQ_RW_SYNC, /* request is sync (O_DIRECT) */ 108 __REQ_ALLOCED, /* request came from our alloc pool */ 109 __REQ_RW_META, /* metadata io request */ 110 __REQ_COPY_USER, /* contains copies of user pages */ 111 __REQ_INTEGRITY, /* integrity metadata has been remapped */ 112 __REQ_NR_BITS, /* stops here */ 113 }; 114 115 #define REQ_RW (1 << __REQ_RW) 116 #define REQ_FAILFAST_DEV (1 << __REQ_FAILFAST_DEV) 117 #define REQ_FAILFAST_TRANSPORT (1 << __REQ_FAILFAST_TRANSPORT) 118 #define REQ_FAILFAST_DRIVER (1 << __REQ_FAILFAST_DRIVER) 119 #define REQ_DISCARD (1 << __REQ_DISCARD) 120 #define REQ_SORTED (1 << __REQ_SORTED) 121 #define REQ_SOFTBARRIER (1 << __REQ_SOFTBARRIER) 122 #define REQ_HARDBARRIER (1 << __REQ_HARDBARRIER) 123 #define REQ_FUA (1 << __REQ_FUA) 124 #define REQ_NOMERGE (1 << __REQ_NOMERGE) 125 #define REQ_STARTED (1 << __REQ_STARTED) 126 #define REQ_DONTPREP (1 << __REQ_DONTPREP) 127 #define REQ_QUEUED (1 << __REQ_QUEUED) 128 #define REQ_ELVPRIV (1 << __REQ_ELVPRIV) 129 #define REQ_FAILED (1 << __REQ_FAILED) 130 #define REQ_QUIET (1 << __REQ_QUIET) 131 #define REQ_PREEMPT (1 << __REQ_PREEMPT) 132 #define REQ_ORDERED_COLOR (1 << __REQ_ORDERED_COLOR) 133 #define REQ_RW_SYNC (1 << __REQ_RW_SYNC) 134 #define REQ_ALLOCED (1 << __REQ_ALLOCED) 135 #define REQ_RW_META (1 << __REQ_RW_META) 136 #define REQ_COPY_USER (1 << __REQ_COPY_USER) 137 #define REQ_INTEGRITY (1 << __REQ_INTEGRITY) 138 139 #define BLK_MAX_CDB 16 140 141 /* 142 * try to put the fields that are referenced together in the same cacheline. 143 * if you modify this structure, be sure to check block/blk-core.c:rq_init() 144 * as well! 145 */ 146 struct request { 147 struct list_head queuelist; 148 struct call_single_data csd; 149 int cpu; 150 151 struct request_queue *q; 152 153 unsigned int cmd_flags; 154 enum rq_cmd_type_bits cmd_type; 155 unsigned long atomic_flags; 156 157 /* Maintain bio traversal state for part by part I/O submission. 158 * hard_* are block layer internals, no driver should touch them! 159 */ 160 161 sector_t sector; /* next sector to submit */ 162 sector_t hard_sector; /* next sector to complete */ 163 unsigned long nr_sectors; /* no. of sectors left to submit */ 164 unsigned long hard_nr_sectors; /* no. of sectors left to complete */ 165 /* no. of sectors left to submit in the current segment */ 166 unsigned int current_nr_sectors; 167 168 /* no. of sectors left to complete in the current segment */ 169 unsigned int hard_cur_sectors; 170 171 struct bio *bio; 172 struct bio *biotail; 173 174 struct hlist_node hash; /* merge hash */ 175 /* 176 * The rb_node is only used inside the io scheduler, requests 177 * are pruned when moved to the dispatch queue. So let the 178 * completion_data share space with the rb_node. 179 */ 180 union { 181 struct rb_node rb_node; /* sort/lookup */ 182 void *completion_data; 183 }; 184 185 /* 186 * two pointers are available for the IO schedulers, if they need 187 * more they have to dynamically allocate it. 188 */ 189 void *elevator_private; 190 void *elevator_private2; 191 192 struct gendisk *rq_disk; 193 unsigned long start_time; 194 195 /* Number of scatter-gather DMA addr+len pairs after 196 * physical address coalescing is performed. 197 */ 198 unsigned short nr_phys_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 long deadline; 224 struct list_head timeout_list; 225 unsigned int timeout; 226 int retries; 227 228 /* 229 * completion callback. 230 */ 231 rq_end_io_fn *end_io; 232 void *end_io_data; 233 234 /* for bidi */ 235 struct request *next_rq; 236 }; 237 238 static inline unsigned short req_get_ioprio(struct request *req) 239 { 240 return req->ioprio; 241 } 242 243 /* 244 * State information carried for REQ_TYPE_PM_SUSPEND and REQ_TYPE_PM_RESUME 245 * requests. Some step values could eventually be made generic. 246 */ 247 struct request_pm_state 248 { 249 /* PM state machine step value, currently driver specific */ 250 int pm_step; 251 /* requested PM state value (S1, S2, S3, S4, ...) */ 252 u32 pm_state; 253 void* data; /* for driver use */ 254 }; 255 256 #include <linux/elevator.h> 257 258 typedef void (request_fn_proc) (struct request_queue *q); 259 typedef int (make_request_fn) (struct request_queue *q, struct bio *bio); 260 typedef int (prep_rq_fn) (struct request_queue *, struct request *); 261 typedef void (unplug_fn) (struct request_queue *); 262 typedef int (prepare_discard_fn) (struct request_queue *, struct request *); 263 264 struct bio_vec; 265 struct bvec_merge_data { 266 struct block_device *bi_bdev; 267 sector_t bi_sector; 268 unsigned bi_size; 269 unsigned long bi_rw; 270 }; 271 typedef int (merge_bvec_fn) (struct request_queue *, struct bvec_merge_data *, 272 struct bio_vec *); 273 typedef void (prepare_flush_fn) (struct request_queue *, struct request *); 274 typedef void (softirq_done_fn)(struct request *); 275 typedef int (dma_drain_needed_fn)(struct request *); 276 typedef int (lld_busy_fn) (struct request_queue *q); 277 278 enum blk_eh_timer_return { 279 BLK_EH_NOT_HANDLED, 280 BLK_EH_HANDLED, 281 BLK_EH_RESET_TIMER, 282 }; 283 284 typedef enum blk_eh_timer_return (rq_timed_out_fn)(struct request *); 285 286 enum blk_queue_state { 287 Queue_down, 288 Queue_up, 289 }; 290 291 struct blk_queue_tag { 292 struct request **tag_index; /* map of busy tags */ 293 unsigned long *tag_map; /* bit map of free/busy tags */ 294 int busy; /* current depth */ 295 int max_depth; /* what we will send to device */ 296 int real_max_depth; /* what the array can hold */ 297 atomic_t refcnt; /* map can be shared */ 298 }; 299 300 #define BLK_SCSI_MAX_CMDS (256) 301 #define BLK_SCSI_CMD_PER_LONG (BLK_SCSI_MAX_CMDS / (sizeof(long) * 8)) 302 303 struct blk_cmd_filter { 304 unsigned long read_ok[BLK_SCSI_CMD_PER_LONG]; 305 unsigned long write_ok[BLK_SCSI_CMD_PER_LONG]; 306 struct kobject kobj; 307 }; 308 309 struct request_queue 310 { 311 /* 312 * Together with queue_head for cacheline sharing 313 */ 314 struct list_head queue_head; 315 struct request *last_merge; 316 elevator_t *elevator; 317 318 /* 319 * the queue request freelist, one for reads and one for writes 320 */ 321 struct request_list rq; 322 323 request_fn_proc *request_fn; 324 make_request_fn *make_request_fn; 325 prep_rq_fn *prep_rq_fn; 326 unplug_fn *unplug_fn; 327 prepare_discard_fn *prepare_discard_fn; 328 merge_bvec_fn *merge_bvec_fn; 329 prepare_flush_fn *prepare_flush_fn; 330 softirq_done_fn *softirq_done_fn; 331 rq_timed_out_fn *rq_timed_out_fn; 332 dma_drain_needed_fn *dma_drain_needed; 333 lld_busy_fn *lld_busy_fn; 334 335 /* 336 * Dispatch queue sorting 337 */ 338 sector_t end_sector; 339 struct request *boundary_rq; 340 341 /* 342 * Auto-unplugging state 343 */ 344 struct timer_list unplug_timer; 345 int unplug_thresh; /* After this many requests */ 346 unsigned long unplug_delay; /* After this many jiffies */ 347 struct work_struct unplug_work; 348 349 struct backing_dev_info backing_dev_info; 350 351 /* 352 * The queue owner gets to use this for whatever they like. 353 * ll_rw_blk doesn't touch it. 354 */ 355 void *queuedata; 356 357 /* 358 * queue needs bounce pages for pages above this limit 359 */ 360 unsigned long bounce_pfn; 361 gfp_t bounce_gfp; 362 363 /* 364 * various queue flags, see QUEUE_* below 365 */ 366 unsigned long queue_flags; 367 368 /* 369 * protects queue structures from reentrancy. ->__queue_lock should 370 * _never_ be used directly, it is queue private. always use 371 * ->queue_lock. 372 */ 373 spinlock_t __queue_lock; 374 spinlock_t *queue_lock; 375 376 /* 377 * queue kobject 378 */ 379 struct kobject kobj; 380 381 /* 382 * queue settings 383 */ 384 unsigned long nr_requests; /* Max # of requests */ 385 unsigned int nr_congestion_on; 386 unsigned int nr_congestion_off; 387 unsigned int nr_batching; 388 389 unsigned int max_sectors; 390 unsigned int max_hw_sectors; 391 unsigned short max_phys_segments; 392 unsigned short max_hw_segments; 393 unsigned short hardsect_size; 394 unsigned int max_segment_size; 395 396 unsigned long seg_boundary_mask; 397 void *dma_drain_buffer; 398 unsigned int dma_drain_size; 399 unsigned int dma_pad_mask; 400 unsigned int dma_alignment; 401 402 struct blk_queue_tag *queue_tags; 403 struct list_head tag_busy_list; 404 405 unsigned int nr_sorted; 406 unsigned int in_flight; 407 408 unsigned int rq_timeout; 409 struct timer_list timeout; 410 struct list_head timeout_list; 411 412 /* 413 * sg stuff 414 */ 415 unsigned int sg_timeout; 416 unsigned int sg_reserved_size; 417 int node; 418 #ifdef CONFIG_BLK_DEV_IO_TRACE 419 struct blk_trace *blk_trace; 420 #endif 421 /* 422 * reserved for flush operations 423 */ 424 unsigned int ordered, next_ordered, ordseq; 425 int orderr, ordcolor; 426 struct request pre_flush_rq, bar_rq, post_flush_rq; 427 struct request *orig_bar_rq; 428 429 struct mutex sysfs_lock; 430 431 #if defined(CONFIG_BLK_DEV_BSG) 432 struct bsg_class_device bsg_dev; 433 #endif 434 struct blk_cmd_filter cmd_filter; 435 }; 436 437 #define QUEUE_FLAG_CLUSTER 0 /* cluster several segments into 1 */ 438 #define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */ 439 #define QUEUE_FLAG_STOPPED 2 /* queue is stopped */ 440 #define QUEUE_FLAG_READFULL 3 /* read queue has been filled */ 441 #define QUEUE_FLAG_WRITEFULL 4 /* write queue has been filled */ 442 #define QUEUE_FLAG_DEAD 5 /* queue being torn down */ 443 #define QUEUE_FLAG_REENTER 6 /* Re-entrancy avoidance */ 444 #define QUEUE_FLAG_PLUGGED 7 /* queue is plugged */ 445 #define QUEUE_FLAG_ELVSWITCH 8 /* don't use elevator, just do FIFO */ 446 #define QUEUE_FLAG_BIDI 9 /* queue supports bidi requests */ 447 #define QUEUE_FLAG_NOMERGES 10 /* disable merge attempts */ 448 #define QUEUE_FLAG_SAME_COMP 11 /* force complete on same CPU */ 449 #define QUEUE_FLAG_FAIL_IO 12 /* fake timeout */ 450 #define QUEUE_FLAG_STACKABLE 13 /* supports request stacking */ 451 #define QUEUE_FLAG_NONROT 14 /* non-rotational device (SSD) */ 452 453 static inline int queue_is_locked(struct request_queue *q) 454 { 455 #ifdef CONFIG_SMP 456 spinlock_t *lock = q->queue_lock; 457 return lock && spin_is_locked(lock); 458 #else 459 return 1; 460 #endif 461 } 462 463 static inline void queue_flag_set_unlocked(unsigned int flag, 464 struct request_queue *q) 465 { 466 __set_bit(flag, &q->queue_flags); 467 } 468 469 static inline int queue_flag_test_and_clear(unsigned int flag, 470 struct request_queue *q) 471 { 472 WARN_ON_ONCE(!queue_is_locked(q)); 473 474 if (test_bit(flag, &q->queue_flags)) { 475 __clear_bit(flag, &q->queue_flags); 476 return 1; 477 } 478 479 return 0; 480 } 481 482 static inline int queue_flag_test_and_set(unsigned int flag, 483 struct request_queue *q) 484 { 485 WARN_ON_ONCE(!queue_is_locked(q)); 486 487 if (!test_bit(flag, &q->queue_flags)) { 488 __set_bit(flag, &q->queue_flags); 489 return 0; 490 } 491 492 return 1; 493 } 494 495 static inline void queue_flag_set(unsigned int flag, struct request_queue *q) 496 { 497 WARN_ON_ONCE(!queue_is_locked(q)); 498 __set_bit(flag, &q->queue_flags); 499 } 500 501 static inline void queue_flag_clear_unlocked(unsigned int flag, 502 struct request_queue *q) 503 { 504 __clear_bit(flag, &q->queue_flags); 505 } 506 507 static inline void queue_flag_clear(unsigned int flag, struct request_queue *q) 508 { 509 WARN_ON_ONCE(!queue_is_locked(q)); 510 __clear_bit(flag, &q->queue_flags); 511 } 512 513 enum { 514 /* 515 * Hardbarrier is supported with one of the following methods. 516 * 517 * NONE : hardbarrier unsupported 518 * DRAIN : ordering by draining is enough 519 * DRAIN_FLUSH : ordering by draining w/ pre and post flushes 520 * DRAIN_FUA : ordering by draining w/ pre flush and FUA write 521 * TAG : ordering by tag is enough 522 * TAG_FLUSH : ordering by tag w/ pre and post flushes 523 * TAG_FUA : ordering by tag w/ pre flush and FUA write 524 */ 525 QUEUE_ORDERED_NONE = 0x00, 526 QUEUE_ORDERED_DRAIN = 0x01, 527 QUEUE_ORDERED_TAG = 0x02, 528 529 QUEUE_ORDERED_PREFLUSH = 0x10, 530 QUEUE_ORDERED_POSTFLUSH = 0x20, 531 QUEUE_ORDERED_FUA = 0x40, 532 533 QUEUE_ORDERED_DRAIN_FLUSH = QUEUE_ORDERED_DRAIN | 534 QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_POSTFLUSH, 535 QUEUE_ORDERED_DRAIN_FUA = QUEUE_ORDERED_DRAIN | 536 QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_FUA, 537 QUEUE_ORDERED_TAG_FLUSH = QUEUE_ORDERED_TAG | 538 QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_POSTFLUSH, 539 QUEUE_ORDERED_TAG_FUA = QUEUE_ORDERED_TAG | 540 QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_FUA, 541 542 /* 543 * Ordered operation sequence 544 */ 545 QUEUE_ORDSEQ_STARTED = 0x01, /* flushing in progress */ 546 QUEUE_ORDSEQ_DRAIN = 0x02, /* waiting for the queue to be drained */ 547 QUEUE_ORDSEQ_PREFLUSH = 0x04, /* pre-flushing in progress */ 548 QUEUE_ORDSEQ_BAR = 0x08, /* original barrier req in progress */ 549 QUEUE_ORDSEQ_POSTFLUSH = 0x10, /* post-flushing in progress */ 550 QUEUE_ORDSEQ_DONE = 0x20, 551 }; 552 553 #define blk_queue_plugged(q) test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags) 554 #define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags) 555 #define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags) 556 #define blk_queue_nomerges(q) test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags) 557 #define blk_queue_nonrot(q) test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags) 558 #define blk_queue_flushing(q) ((q)->ordseq) 559 #define blk_queue_stackable(q) \ 560 test_bit(QUEUE_FLAG_STACKABLE, &(q)->queue_flags) 561 562 #define blk_fs_request(rq) ((rq)->cmd_type == REQ_TYPE_FS) 563 #define blk_pc_request(rq) ((rq)->cmd_type == REQ_TYPE_BLOCK_PC) 564 #define blk_special_request(rq) ((rq)->cmd_type == REQ_TYPE_SPECIAL) 565 #define blk_sense_request(rq) ((rq)->cmd_type == REQ_TYPE_SENSE) 566 567 #define blk_failfast_dev(rq) ((rq)->cmd_flags & REQ_FAILFAST_DEV) 568 #define blk_failfast_transport(rq) ((rq)->cmd_flags & REQ_FAILFAST_TRANSPORT) 569 #define blk_failfast_driver(rq) ((rq)->cmd_flags & REQ_FAILFAST_DRIVER) 570 #define blk_noretry_request(rq) (blk_failfast_dev(rq) || \ 571 blk_failfast_transport(rq) || \ 572 blk_failfast_driver(rq)) 573 #define blk_rq_started(rq) ((rq)->cmd_flags & REQ_STARTED) 574 575 #define blk_account_rq(rq) (blk_rq_started(rq) && (blk_fs_request(rq) || blk_discard_rq(rq))) 576 577 #define blk_pm_suspend_request(rq) ((rq)->cmd_type == REQ_TYPE_PM_SUSPEND) 578 #define blk_pm_resume_request(rq) ((rq)->cmd_type == REQ_TYPE_PM_RESUME) 579 #define blk_pm_request(rq) \ 580 (blk_pm_suspend_request(rq) || blk_pm_resume_request(rq)) 581 582 #define blk_rq_cpu_valid(rq) ((rq)->cpu != -1) 583 #define blk_sorted_rq(rq) ((rq)->cmd_flags & REQ_SORTED) 584 #define blk_barrier_rq(rq) ((rq)->cmd_flags & REQ_HARDBARRIER) 585 #define blk_fua_rq(rq) ((rq)->cmd_flags & REQ_FUA) 586 #define blk_discard_rq(rq) ((rq)->cmd_flags & REQ_DISCARD) 587 #define blk_bidi_rq(rq) ((rq)->next_rq != NULL) 588 #define blk_empty_barrier(rq) (blk_barrier_rq(rq) && blk_fs_request(rq) && !(rq)->hard_nr_sectors) 589 /* rq->queuelist of dequeued request must be list_empty() */ 590 #define blk_queued_rq(rq) (!list_empty(&(rq)->queuelist)) 591 592 #define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist) 593 594 #define rq_data_dir(rq) ((rq)->cmd_flags & 1) 595 596 /* 597 * We regard a request as sync, if it's a READ or a SYNC write. 598 */ 599 #define rq_is_sync(rq) (rq_data_dir((rq)) == READ || (rq)->cmd_flags & REQ_RW_SYNC) 600 #define rq_is_meta(rq) ((rq)->cmd_flags & REQ_RW_META) 601 602 static inline int blk_queue_full(struct request_queue *q, int rw) 603 { 604 if (rw == READ) 605 return test_bit(QUEUE_FLAG_READFULL, &q->queue_flags); 606 return test_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags); 607 } 608 609 static inline void blk_set_queue_full(struct request_queue *q, int rw) 610 { 611 if (rw == READ) 612 queue_flag_set(QUEUE_FLAG_READFULL, q); 613 else 614 queue_flag_set(QUEUE_FLAG_WRITEFULL, q); 615 } 616 617 static inline void blk_clear_queue_full(struct request_queue *q, int rw) 618 { 619 if (rw == READ) 620 queue_flag_clear(QUEUE_FLAG_READFULL, q); 621 else 622 queue_flag_clear(QUEUE_FLAG_WRITEFULL, q); 623 } 624 625 626 /* 627 * mergeable request must not have _NOMERGE or _BARRIER bit set, nor may 628 * it already be started by driver. 629 */ 630 #define RQ_NOMERGE_FLAGS \ 631 (REQ_NOMERGE | REQ_STARTED | REQ_HARDBARRIER | REQ_SOFTBARRIER) 632 #define rq_mergeable(rq) \ 633 (!((rq)->cmd_flags & RQ_NOMERGE_FLAGS) && \ 634 (blk_discard_rq(rq) || blk_fs_request((rq)))) 635 636 /* 637 * q->prep_rq_fn return values 638 */ 639 #define BLKPREP_OK 0 /* serve it */ 640 #define BLKPREP_KILL 1 /* fatal error, kill */ 641 #define BLKPREP_DEFER 2 /* leave on queue */ 642 643 extern unsigned long blk_max_low_pfn, blk_max_pfn; 644 645 /* 646 * standard bounce addresses: 647 * 648 * BLK_BOUNCE_HIGH : bounce all highmem pages 649 * BLK_BOUNCE_ANY : don't bounce anything 650 * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary 651 */ 652 653 #if BITS_PER_LONG == 32 654 #define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT) 655 #else 656 #define BLK_BOUNCE_HIGH -1ULL 657 #endif 658 #define BLK_BOUNCE_ANY (-1ULL) 659 #define BLK_BOUNCE_ISA (ISA_DMA_THRESHOLD) 660 661 /* 662 * default timeout for SG_IO if none specified 663 */ 664 #define BLK_DEFAULT_SG_TIMEOUT (60 * HZ) 665 666 #ifdef CONFIG_BOUNCE 667 extern int init_emergency_isa_pool(void); 668 extern void blk_queue_bounce(struct request_queue *q, struct bio **bio); 669 #else 670 static inline int init_emergency_isa_pool(void) 671 { 672 return 0; 673 } 674 static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio) 675 { 676 } 677 #endif /* CONFIG_MMU */ 678 679 struct rq_map_data { 680 struct page **pages; 681 int page_order; 682 int nr_entries; 683 }; 684 685 struct req_iterator { 686 int i; 687 struct bio *bio; 688 }; 689 690 /* This should not be used directly - use rq_for_each_segment */ 691 #define __rq_for_each_bio(_bio, rq) \ 692 if ((rq->bio)) \ 693 for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next) 694 695 #define rq_for_each_segment(bvl, _rq, _iter) \ 696 __rq_for_each_bio(_iter.bio, _rq) \ 697 bio_for_each_segment(bvl, _iter.bio, _iter.i) 698 699 #define rq_iter_last(rq, _iter) \ 700 (_iter.bio->bi_next == NULL && _iter.i == _iter.bio->bi_vcnt-1) 701 702 extern int blk_register_queue(struct gendisk *disk); 703 extern void blk_unregister_queue(struct gendisk *disk); 704 extern void register_disk(struct gendisk *dev); 705 extern void generic_make_request(struct bio *bio); 706 extern void blk_rq_init(struct request_queue *q, struct request *rq); 707 extern void blk_put_request(struct request *); 708 extern void __blk_put_request(struct request_queue *, struct request *); 709 extern struct request *blk_get_request(struct request_queue *, int, gfp_t); 710 extern void blk_insert_request(struct request_queue *, struct request *, int, void *); 711 extern void blk_requeue_request(struct request_queue *, struct request *); 712 extern int blk_rq_check_limits(struct request_queue *q, struct request *rq); 713 extern int blk_lld_busy(struct request_queue *q); 714 extern int blk_insert_cloned_request(struct request_queue *q, 715 struct request *rq); 716 extern void blk_plug_device(struct request_queue *); 717 extern void blk_plug_device_unlocked(struct request_queue *); 718 extern int blk_remove_plug(struct request_queue *); 719 extern void blk_recount_segments(struct request_queue *, struct bio *); 720 extern int scsi_cmd_ioctl(struct file *, struct request_queue *, 721 struct gendisk *, unsigned int, void __user *); 722 extern int sg_scsi_ioctl(struct file *, struct request_queue *, 723 struct gendisk *, struct scsi_ioctl_command __user *); 724 725 /* 726 * Temporary export, until SCSI gets fixed up. 727 */ 728 extern int blk_rq_append_bio(struct request_queue *q, struct request *rq, 729 struct bio *bio); 730 731 /* 732 * A queue has just exitted congestion. Note this in the global counter of 733 * congested queues, and wake up anyone who was waiting for requests to be 734 * put back. 735 */ 736 static inline void blk_clear_queue_congested(struct request_queue *q, int rw) 737 { 738 clear_bdi_congested(&q->backing_dev_info, rw); 739 } 740 741 /* 742 * A queue has just entered congestion. Flag that in the queue's VM-visible 743 * state flags and increment the global gounter of congested queues. 744 */ 745 static inline void blk_set_queue_congested(struct request_queue *q, int rw) 746 { 747 set_bdi_congested(&q->backing_dev_info, rw); 748 } 749 750 extern void blk_start_queue(struct request_queue *q); 751 extern void blk_stop_queue(struct request_queue *q); 752 extern void blk_sync_queue(struct request_queue *q); 753 extern void __blk_stop_queue(struct request_queue *q); 754 extern void __blk_run_queue(struct request_queue *); 755 extern void blk_run_queue(struct request_queue *); 756 extern void blk_start_queueing(struct request_queue *); 757 extern int blk_rq_map_user(struct request_queue *, struct request *, 758 struct rq_map_data *, void __user *, unsigned long, 759 gfp_t); 760 extern int blk_rq_unmap_user(struct bio *); 761 extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, unsigned int, gfp_t); 762 extern int blk_rq_map_user_iov(struct request_queue *, struct request *, 763 struct rq_map_data *, struct sg_iovec *, int, 764 unsigned int, gfp_t); 765 extern int blk_execute_rq(struct request_queue *, struct gendisk *, 766 struct request *, int); 767 extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *, 768 struct request *, int, rq_end_io_fn *); 769 extern void blk_unplug(struct request_queue *q); 770 771 static inline struct request_queue *bdev_get_queue(struct block_device *bdev) 772 { 773 return bdev->bd_disk->queue; 774 } 775 776 static inline void blk_run_backing_dev(struct backing_dev_info *bdi, 777 struct page *page) 778 { 779 if (bdi && bdi->unplug_io_fn) 780 bdi->unplug_io_fn(bdi, page); 781 } 782 783 static inline void blk_run_address_space(struct address_space *mapping) 784 { 785 if (mapping) 786 blk_run_backing_dev(mapping->backing_dev_info, NULL); 787 } 788 789 /* 790 * blk_end_request() and friends. 791 * __blk_end_request() and end_request() must be called with 792 * the request queue spinlock acquired. 793 * 794 * Several drivers define their own end_request and call 795 * blk_end_request() for parts of the original function. 796 * This prevents code duplication in drivers. 797 */ 798 extern int blk_end_request(struct request *rq, int error, 799 unsigned int nr_bytes); 800 extern int __blk_end_request(struct request *rq, int error, 801 unsigned int nr_bytes); 802 extern int blk_end_bidi_request(struct request *rq, int error, 803 unsigned int nr_bytes, unsigned int bidi_bytes); 804 extern void end_request(struct request *, int); 805 extern int blk_end_request_callback(struct request *rq, int error, 806 unsigned int nr_bytes, 807 int (drv_callback)(struct request *)); 808 extern void blk_complete_request(struct request *); 809 extern void __blk_complete_request(struct request *); 810 extern void blk_abort_request(struct request *); 811 extern void blk_abort_queue(struct request_queue *); 812 extern void blk_update_request(struct request *rq, int error, 813 unsigned int nr_bytes); 814 815 /* 816 * blk_end_request() takes bytes instead of sectors as a complete size. 817 * blk_rq_bytes() returns bytes left to complete in the entire request. 818 * blk_rq_cur_bytes() returns bytes left to complete in the current segment. 819 */ 820 extern unsigned int blk_rq_bytes(struct request *rq); 821 extern unsigned int blk_rq_cur_bytes(struct request *rq); 822 823 static inline void blkdev_dequeue_request(struct request *req) 824 { 825 elv_dequeue_request(req->q, req); 826 } 827 828 /* 829 * Access functions for manipulating queue properties 830 */ 831 extern struct request_queue *blk_init_queue_node(request_fn_proc *rfn, 832 spinlock_t *lock, int node_id); 833 extern struct request_queue *blk_init_queue(request_fn_proc *, spinlock_t *); 834 extern void blk_cleanup_queue(struct request_queue *); 835 extern void blk_queue_make_request(struct request_queue *, make_request_fn *); 836 extern void blk_queue_bounce_limit(struct request_queue *, u64); 837 extern void blk_queue_max_sectors(struct request_queue *, unsigned int); 838 extern void blk_queue_max_phys_segments(struct request_queue *, unsigned short); 839 extern void blk_queue_max_hw_segments(struct request_queue *, unsigned short); 840 extern void blk_queue_max_segment_size(struct request_queue *, unsigned int); 841 extern void blk_queue_hardsect_size(struct request_queue *, unsigned short); 842 extern void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b); 843 extern void blk_queue_dma_pad(struct request_queue *, unsigned int); 844 extern void blk_queue_update_dma_pad(struct request_queue *, unsigned int); 845 extern int blk_queue_dma_drain(struct request_queue *q, 846 dma_drain_needed_fn *dma_drain_needed, 847 void *buf, unsigned int size); 848 extern void blk_queue_lld_busy(struct request_queue *q, lld_busy_fn *fn); 849 extern void blk_queue_segment_boundary(struct request_queue *, unsigned long); 850 extern void blk_queue_prep_rq(struct request_queue *, prep_rq_fn *pfn); 851 extern void blk_queue_merge_bvec(struct request_queue *, merge_bvec_fn *); 852 extern void blk_queue_dma_alignment(struct request_queue *, int); 853 extern void blk_queue_update_dma_alignment(struct request_queue *, int); 854 extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *); 855 extern void blk_queue_set_discard(struct request_queue *, prepare_discard_fn *); 856 extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *); 857 extern void blk_queue_rq_timeout(struct request_queue *, unsigned int); 858 extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev); 859 extern int blk_queue_ordered(struct request_queue *, unsigned, prepare_flush_fn *); 860 extern int blk_do_ordered(struct request_queue *, struct request **); 861 extern unsigned blk_ordered_cur_seq(struct request_queue *); 862 extern unsigned blk_ordered_req_seq(struct request *); 863 extern void blk_ordered_complete_seq(struct request_queue *, unsigned, int); 864 865 extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *); 866 extern void blk_dump_rq_flags(struct request *, char *); 867 extern void generic_unplug_device(struct request_queue *); 868 extern long nr_blockdev_pages(void); 869 870 int blk_get_queue(struct request_queue *); 871 struct request_queue *blk_alloc_queue(gfp_t); 872 struct request_queue *blk_alloc_queue_node(gfp_t, int); 873 extern void blk_put_queue(struct request_queue *); 874 875 /* 876 * tag stuff 877 */ 878 #define blk_rq_tagged(rq) ((rq)->cmd_flags & REQ_QUEUED) 879 extern int blk_queue_start_tag(struct request_queue *, struct request *); 880 extern struct request *blk_queue_find_tag(struct request_queue *, int); 881 extern void blk_queue_end_tag(struct request_queue *, struct request *); 882 extern int blk_queue_init_tags(struct request_queue *, int, struct blk_queue_tag *); 883 extern void blk_queue_free_tags(struct request_queue *); 884 extern int blk_queue_resize_tags(struct request_queue *, int); 885 extern void blk_queue_invalidate_tags(struct request_queue *); 886 extern struct blk_queue_tag *blk_init_tags(int); 887 extern void blk_free_tags(struct blk_queue_tag *); 888 889 static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt, 890 int tag) 891 { 892 if (unlikely(bqt == NULL || tag >= bqt->real_max_depth)) 893 return NULL; 894 return bqt->tag_index[tag]; 895 } 896 897 extern int blkdev_issue_flush(struct block_device *, sector_t *); 898 extern int blkdev_issue_discard(struct block_device *, 899 sector_t sector, sector_t nr_sects, gfp_t); 900 901 static inline int sb_issue_discard(struct super_block *sb, 902 sector_t block, sector_t nr_blocks) 903 { 904 block <<= (sb->s_blocksize_bits - 9); 905 nr_blocks <<= (sb->s_blocksize_bits - 9); 906 return blkdev_issue_discard(sb->s_bdev, block, nr_blocks, GFP_KERNEL); 907 } 908 909 /* 910 * command filter functions 911 */ 912 extern int blk_verify_command(struct blk_cmd_filter *filter, 913 unsigned char *cmd, int has_write_perm); 914 extern void blk_set_cmd_filter_defaults(struct blk_cmd_filter *filter); 915 916 #define MAX_PHYS_SEGMENTS 128 917 #define MAX_HW_SEGMENTS 128 918 #define SAFE_MAX_SECTORS 255 919 #define BLK_DEF_MAX_SECTORS 1024 920 921 #define MAX_SEGMENT_SIZE 65536 922 923 #define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist) 924 925 static inline int queue_hardsect_size(struct request_queue *q) 926 { 927 int retval = 512; 928 929 if (q && q->hardsect_size) 930 retval = q->hardsect_size; 931 932 return retval; 933 } 934 935 static inline int bdev_hardsect_size(struct block_device *bdev) 936 { 937 return queue_hardsect_size(bdev_get_queue(bdev)); 938 } 939 940 static inline int queue_dma_alignment(struct request_queue *q) 941 { 942 return q ? q->dma_alignment : 511; 943 } 944 945 static inline int blk_rq_aligned(struct request_queue *q, void *addr, 946 unsigned int len) 947 { 948 unsigned int alignment = queue_dma_alignment(q) | q->dma_pad_mask; 949 return !((unsigned long)addr & alignment) && !(len & alignment); 950 } 951 952 /* assumes size > 256 */ 953 static inline unsigned int blksize_bits(unsigned int size) 954 { 955 unsigned int bits = 8; 956 do { 957 bits++; 958 size >>= 1; 959 } while (size > 256); 960 return bits; 961 } 962 963 static inline unsigned int block_size(struct block_device *bdev) 964 { 965 return bdev->bd_block_size; 966 } 967 968 typedef struct {struct page *v;} Sector; 969 970 unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *); 971 972 static inline void put_dev_sector(Sector p) 973 { 974 page_cache_release(p.v); 975 } 976 977 struct work_struct; 978 int kblockd_schedule_work(struct request_queue *q, struct work_struct *work); 979 void kblockd_flush_work(struct work_struct *work); 980 981 #define MODULE_ALIAS_BLOCKDEV(major,minor) \ 982 MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor)) 983 #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \ 984 MODULE_ALIAS("block-major-" __stringify(major) "-*") 985 986 #if defined(CONFIG_BLK_DEV_INTEGRITY) 987 988 #define INTEGRITY_FLAG_READ 2 /* verify data integrity on read */ 989 #define INTEGRITY_FLAG_WRITE 4 /* generate data integrity on write */ 990 991 struct blk_integrity_exchg { 992 void *prot_buf; 993 void *data_buf; 994 sector_t sector; 995 unsigned int data_size; 996 unsigned short sector_size; 997 const char *disk_name; 998 }; 999 1000 typedef void (integrity_gen_fn) (struct blk_integrity_exchg *); 1001 typedef int (integrity_vrfy_fn) (struct blk_integrity_exchg *); 1002 typedef void (integrity_set_tag_fn) (void *, void *, unsigned int); 1003 typedef void (integrity_get_tag_fn) (void *, void *, unsigned int); 1004 1005 struct blk_integrity { 1006 integrity_gen_fn *generate_fn; 1007 integrity_vrfy_fn *verify_fn; 1008 integrity_set_tag_fn *set_tag_fn; 1009 integrity_get_tag_fn *get_tag_fn; 1010 1011 unsigned short flags; 1012 unsigned short tuple_size; 1013 unsigned short sector_size; 1014 unsigned short tag_size; 1015 1016 const char *name; 1017 1018 struct kobject kobj; 1019 }; 1020 1021 extern int blk_integrity_register(struct gendisk *, struct blk_integrity *); 1022 extern void blk_integrity_unregister(struct gendisk *); 1023 extern int blk_integrity_compare(struct gendisk *, struct gendisk *); 1024 extern int blk_rq_map_integrity_sg(struct request *, struct scatterlist *); 1025 extern int blk_rq_count_integrity_sg(struct request *); 1026 1027 static inline 1028 struct blk_integrity *bdev_get_integrity(struct block_device *bdev) 1029 { 1030 return bdev->bd_disk->integrity; 1031 } 1032 1033 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk) 1034 { 1035 return disk->integrity; 1036 } 1037 1038 static inline int blk_integrity_rq(struct request *rq) 1039 { 1040 if (rq->bio == NULL) 1041 return 0; 1042 1043 return bio_integrity(rq->bio); 1044 } 1045 1046 #else /* CONFIG_BLK_DEV_INTEGRITY */ 1047 1048 #define blk_integrity_rq(rq) (0) 1049 #define blk_rq_count_integrity_sg(a) (0) 1050 #define blk_rq_map_integrity_sg(a, b) (0) 1051 #define bdev_get_integrity(a) (0) 1052 #define blk_get_integrity(a) (0) 1053 #define blk_integrity_compare(a, b) (0) 1054 #define blk_integrity_register(a, b) (0) 1055 #define blk_integrity_unregister(a) do { } while (0); 1056 1057 #endif /* CONFIG_BLK_DEV_INTEGRITY */ 1058 1059 #else /* CONFIG_BLOCK */ 1060 /* 1061 * stubs for when the block layer is configured out 1062 */ 1063 #define buffer_heads_over_limit 0 1064 1065 static inline long nr_blockdev_pages(void) 1066 { 1067 return 0; 1068 } 1069 1070 #endif /* CONFIG_BLOCK */ 1071 1072 #endif 1073