include/linux/blkdev.h

   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 struct request_pm_state;
  30 struct blk_trace;
  31 struct request;
  32 struct sg_io_hdr;
  33
  34 #define BLKDEV_MIN_RQ   4
  35 #define BLKDEV_MAX_RQ   128     /* Default maximum */
  36
  37 struct request;
  38 typedef void (rq_end_io_fn)(struct request *, int);
  39
  40 struct request_list {
  41         /*
  42          * count[], starved[], and wait[] are indexed by
  43          * BLK_RW_SYNC/BLK_RW_ASYNC
  44          */
  45         int count[2];
  46         int starved[2];
  47         int elvpriv;
  48         mempool_t *rq_pool;
  49         wait_queue_head_t wait[2];
  50 };
  51
  52 /*
  53  * request command types
  54  */
  55 enum rq_cmd_type_bits {
  56         REQ_TYPE_FS             = 1,    /* fs request */
  57         REQ_TYPE_BLOCK_PC,              /* scsi command */
  58         REQ_TYPE_SENSE,                 /* sense request */
  59         REQ_TYPE_PM_SUSPEND,            /* suspend request */
  60         REQ_TYPE_PM_RESUME,             /* resume request */
  61         REQ_TYPE_PM_SHUTDOWN,           /* shutdown request */
  62         REQ_TYPE_SPECIAL,               /* driver defined type */
  63         /*
  64          * for ATA/ATAPI devices. this really doesn't belong here, ide should
  65          * use REQ_TYPE_SPECIAL and use rq->cmd[0] with the range of driver
  66          * private REQ_LB opcodes to differentiate what type of request this is
  67          */
  68         REQ_TYPE_ATA_TASKFILE,
  69         REQ_TYPE_ATA_PC,
  70 };
  71
  72 #define BLK_MAX_CDB     16
  73
  74 /*
  75  * try to put the fields that are referenced together in the same cacheline.
  76  * if you modify this structure, be sure to check block/blk-core.c:rq_init()
  77  * as well!
  78  */
  79 struct request {
  80         struct list_head queuelist;
  81         struct call_single_data csd;
  82
  83         struct request_queue *q;
  84
  85         unsigned int cmd_flags;
  86         enum rq_cmd_type_bits cmd_type;
  87         unsigned long atomic_flags;
  88
  89         int cpu;
  90
  91         /* the following two fields are internal, NEVER access directly */
  92         unsigned int __data_len;        /* total data len */
  93         sector_t __sector;              /* sector cursor */
  94
  95         struct bio *bio;
  96         struct bio *biotail;
  97
  98         struct hlist_node hash; /* merge hash */
  99         /*
 100          * The rb_node is only used inside the io scheduler, requests
 101          * are pruned when moved to the dispatch queue. So let the
 102          * completion_data share space with the rb_node.
 103          */
 104         union {
 105                 struct rb_node rb_node; /* sort/lookup */
 106                 void *completion_data;
 107         };
 108
 109         /*
 110          * Three pointers are available for the IO schedulers, if they need
 111          * more they have to dynamically allocate it.
 112          */
 113         void *elevator_private;
 114         void *elevator_private2;
 115         void *elevator_private3;
 116
 117         struct gendisk *rq_disk;
 118         unsigned long start_time;
 119 #ifdef CONFIG_BLK_CGROUP
 120         unsigned long long start_time_ns;
 121         unsigned long long io_start_time_ns;    /* when passed to hardware */
 122 #endif
 123         /* Number of scatter-gather DMA addr+len pairs after
 124          * physical address coalescing is performed.
 125          */
 126         unsigned short nr_phys_segments;
 127 #if defined(CONFIG_BLK_DEV_INTEGRITY)
 128         unsigned short nr_integrity_segments;
 129 #endif
 130
 131         unsigned short ioprio;
 132
 133         int ref_count;
 134
 135         void *special;          /* opaque pointer available for LLD use */
 136         char *buffer;           /* kaddr of the current segment if available */
 137
 138         int tag;
 139         int errors;
 140
 141         /*
 142          * when request is used as a packet command carrier
 143          */
 144         unsigned char __cmd[BLK_MAX_CDB];
 145         unsigned char *cmd;
 146         unsigned short cmd_len;
 147
 148         unsigned int extra_len; /* length of alignment and padding */
 149         unsigned int sense_len;
 150         unsigned int resid_len; /* residual count */
 151         void *sense;
 152
 153         unsigned long deadline;
 154         struct list_head timeout_list;
 155         unsigned int timeout;
 156         int retries;
 157
 158         /*
 159          * completion callback.
 160          */
 161         rq_end_io_fn *end_io;
 162         void *end_io_data;
 163
 164         /* for bidi */
 165         struct request *next_rq;
 166 };
 167
 168 static inline unsigned short req_get_ioprio(struct request *req)
 169 {
 170         return req->ioprio;
 171 }
 172
 173 /*
 174  * State information carried for REQ_TYPE_PM_SUSPEND and REQ_TYPE_PM_RESUME
 175  * requests. Some step values could eventually be made generic.
 176  */
 177 struct request_pm_state
 178 {
 179         /* PM state machine step value, currently driver specific */
 180         int     pm_step;
 181         /* requested PM state value (S1, S2, S3, S4, ...) */
 182         u32     pm_state;
 183         void*   data;           /* for driver use */
 184 };
 185
 186 #include <linux/elevator.h>
 187
 188 typedef void (request_fn_proc) (struct request_queue *q);
 189 typedef int (make_request_fn) (struct request_queue *q, struct bio *bio);
 190 typedef int (prep_rq_fn) (struct request_queue *, struct request *);
 191 typedef void (unprep_rq_fn) (struct request_queue *, struct request *);
 192 typedef void (unplug_fn) (struct request_queue *);
 193
 194 struct bio_vec;
 195 struct bvec_merge_data {
 196         struct block_device *bi_bdev;
 197         sector_t bi_sector;
 198         unsigned bi_size;
 199         unsigned long bi_rw;
 200 };
 201 typedef int (merge_bvec_fn) (struct request_queue *, struct bvec_merge_data *,
 202                              struct bio_vec *);
 203 typedef void (softirq_done_fn)(struct request *);
 204 typedef int (dma_drain_needed_fn)(struct request *);
 205 typedef int (lld_busy_fn) (struct request_queue *q);
 206
 207 enum blk_eh_timer_return {
 208         BLK_EH_NOT_HANDLED,
 209         BLK_EH_HANDLED,
 210         BLK_EH_RESET_TIMER,
 211 };
 212
 213 typedef enum blk_eh_timer_return (rq_timed_out_fn)(struct request *);
 214
 215 enum blk_queue_state {
 216         Queue_down,
 217         Queue_up,
 218 };
 219
 220 struct blk_queue_tag {
 221         struct request **tag_index;     /* map of busy tags */
 222         unsigned long *tag_map;         /* bit map of free/busy tags */
 223         int busy;                       /* current depth */
 224         int max_depth;                  /* what we will send to device */
 225         int real_max_depth;             /* what the array can hold */
 226         atomic_t refcnt;                /* map can be shared */
 227 };
 228
 229 #define BLK_SCSI_MAX_CMDS       (256)
 230 #define BLK_SCSI_CMD_PER_LONG   (BLK_SCSI_MAX_CMDS / (sizeof(long) * 8))
 231
 232 struct queue_limits {
 233         unsigned long           bounce_pfn;
 234         unsigned long           seg_boundary_mask;
 235
 236         unsigned int            max_hw_sectors;
 237         unsigned int            max_sectors;
 238         unsigned int            max_segment_size;
 239         unsigned int            physical_block_size;
 240         unsigned int            alignment_offset;
 241         unsigned int            io_min;
 242         unsigned int            io_opt;
 243         unsigned int            max_discard_sectors;
 244         unsigned int            discard_granularity;
 245         unsigned int            discard_alignment;
 246
 247         unsigned short          logical_block_size;
 248         unsigned short          max_segments;
 249         unsigned short          max_integrity_segments;
 250
 251         unsigned char           misaligned;
 252         unsigned char           discard_misaligned;
 253         unsigned char           cluster;
 254         signed char             discard_zeroes_data;
 255 };
 256
 257 struct request_queue
 258 {
 259         /*
 260          * Together with queue_head for cacheline sharing
 261          */
 262         struct list_head        queue_head;
 263         struct request          *last_merge;
 264         struct elevator_queue   *elevator;
 265
 266         /*
 267          * the queue request freelist, one for reads and one for writes
 268          */
 269         struct request_list     rq;
 270
 271         request_fn_proc         *request_fn;
 272         make_request_fn         *make_request_fn;
 273         prep_rq_fn              *prep_rq_fn;
 274         unprep_rq_fn            *unprep_rq_fn;
 275         unplug_fn               *unplug_fn;
 276         merge_bvec_fn           *merge_bvec_fn;
 277         softirq_done_fn         *softirq_done_fn;
 278         rq_timed_out_fn         *rq_timed_out_fn;
 279         dma_drain_needed_fn     *dma_drain_needed;
 280         lld_busy_fn             *lld_busy_fn;
 281
 282         /*
 283          * Dispatch queue sorting
 284          */
 285         sector_t                end_sector;
 286         struct request          *boundary_rq;
 287
 288         /*
 289          * Auto-unplugging state
 290          */
 291         struct timer_list       unplug_timer;
 292         int                     unplug_thresh;  /* After this many requests */
 293         unsigned long           unplug_delay;   /* After this many jiffies */
 294         struct work_struct      unplug_work;
 295
 296         struct backing_dev_info backing_dev_info;
 297
 298         /*
 299          * The queue owner gets to use this for whatever they like.
 300          * ll_rw_blk doesn't touch it.
 301          */
 302         void                    *queuedata;
 303
 304         /*
 305          * queue needs bounce pages for pages above this limit
 306          */
 307         gfp_t                   bounce_gfp;
 308
 309         /*
 310          * various queue flags, see QUEUE_* below
 311          */
 312         unsigned long           queue_flags;
 313
 314         /*
 315          * protects queue structures from reentrancy. ->__queue_lock should
 316          * _never_ be used directly, it is queue private. always use
 317          * ->queue_lock.
 318          */
 319         spinlock_t              __queue_lock;
 320         spinlock_t              *queue_lock;
 321
 322         /*
 323          * queue kobject
 324          */
 325         struct kobject kobj;
 326
 327         /*
 328          * queue settings
 329          */
 330         unsigned long           nr_requests;    /* Max # of requests */
 331         unsigned int            nr_congestion_on;
 332         unsigned int            nr_congestion_off;
 333         unsigned int            nr_batching;
 334
 335         void                    *dma_drain_buffer;
 336         unsigned int            dma_drain_size;
 337         unsigned int            dma_pad_mask;
 338         unsigned int            dma_alignment;
 339
 340         struct blk_queue_tag    *queue_tags;
 341         struct list_head        tag_busy_list;
 342
 343         unsigned int            nr_sorted;
 344         unsigned int            in_flight[2];
 345
 346         unsigned int            rq_timeout;
 347         struct timer_list       timeout;
 348         struct list_head        timeout_list;
 349
 350         struct queue_limits     limits;
 351
 352         /*
 353          * sg stuff
 354          */
 355         unsigned int            sg_timeout;
 356         unsigned int            sg_reserved_size;
 357         int                     node;
 358 #ifdef CONFIG_BLK_DEV_IO_TRACE
 359         struct blk_trace        *blk_trace;
 360 #endif
 361         /*
 362          * for flush operations
 363          */
 364         unsigned int            flush_flags;
 365         unsigned int            flush_seq;
 366         int                     flush_err;
 367         struct request          flush_rq;
 368         struct request          *orig_flush_rq;
 369         struct list_head        pending_flushes;
 370
 371         struct mutex            sysfs_lock;
 372
 373 #if defined(CONFIG_BLK_DEV_BSG)
 374         struct bsg_class_device bsg_dev;
 375 #endif
 376
 377 #ifdef CONFIG_BLK_DEV_THROTTLING
 378         /* Throttle data */
 379         struct throtl_data *td;
 380 #endif
 381 };
 382
 383 #define QUEUE_FLAG_QUEUED       1       /* uses generic tag queueing */
 384 #define QUEUE_FLAG_STOPPED      2       /* queue is stopped */
 385 #define QUEUE_FLAG_SYNCFULL     3       /* read queue has been filled */
 386 #define QUEUE_FLAG_ASYNCFULL    4       /* write queue has been filled */
 387 #define QUEUE_FLAG_DEAD         5       /* queue being torn down */
 388 #define QUEUE_FLAG_REENTER      6       /* Re-entrancy avoidance */
 389 #define QUEUE_FLAG_PLUGGED      7       /* queue is plugged */
 390 #define QUEUE_FLAG_ELVSWITCH    8       /* don't use elevator, just do FIFO */
 391 #define QUEUE_FLAG_BIDI         9       /* queue supports bidi requests */
 392 #define QUEUE_FLAG_NOMERGES    10       /* disable merge attempts */
 393 #define QUEUE_FLAG_SAME_COMP   11       /* force complete on same CPU */
 394 #define QUEUE_FLAG_FAIL_IO     12       /* fake timeout */
 395 #define QUEUE_FLAG_STACKABLE   13       /* supports request stacking */
 396 #define QUEUE_FLAG_NONROT      14       /* non-rotational device (SSD) */
 397 #define QUEUE_FLAG_VIRT        QUEUE_FLAG_NONROT /* paravirt device */
 398 #define QUEUE_FLAG_IO_STAT     15       /* do IO stats */
 399 #define QUEUE_FLAG_DISCARD     16       /* supports DISCARD */
 400 #define QUEUE_FLAG_NOXMERGES   17       /* No extended merges */
 401 #define QUEUE_FLAG_ADD_RANDOM  18       /* Contributes to random pool */
 402 #define QUEUE_FLAG_SECDISCARD  19       /* supports SECDISCARD */
 403
 404 #define QUEUE_FLAG_DEFAULT      ((1 << QUEUE_FLAG_IO_STAT) |            \
 405                                  (1 << QUEUE_FLAG_STACKABLE)    |       \
 406                                  (1 << QUEUE_FLAG_SAME_COMP)    |       \
 407                                  (1 << QUEUE_FLAG_ADD_RANDOM))
 408
 409 static inline int queue_is_locked(struct request_queue *q)
 410 {
 411 #ifdef CONFIG_SMP
 412         spinlock_t *lock = q->queue_lock;
 413         return lock && spin_is_locked(lock);
 414 #else
 415         return 1;
 416 #endif
 417 }
 418
 419 static inline void queue_flag_set_unlocked(unsigned int flag,
 420                                            struct request_queue *q)
 421 {
 422         __set_bit(flag, &q->queue_flags);
 423 }
 424
 425 static inline int queue_flag_test_and_clear(unsigned int flag,
 426                                             struct request_queue *q)
 427 {
 428         WARN_ON_ONCE(!queue_is_locked(q));
 429
 430         if (test_bit(flag, &q->queue_flags)) {
 431                 __clear_bit(flag, &q->queue_flags);
 432                 return 1;
 433         }
 434
 435         return 0;
 436 }
 437
 438 static inline int queue_flag_test_and_set(unsigned int flag,
 439                                           struct request_queue *q)
 440 {
 441         WARN_ON_ONCE(!queue_is_locked(q));
 442
 443         if (!test_bit(flag, &q->queue_flags)) {
 444                 __set_bit(flag, &q->queue_flags);
 445                 return 0;
 446         }
 447
 448         return 1;
 449 }
 450
 451 static inline void queue_flag_set(unsigned int flag, struct request_queue *q)
 452 {
 453         WARN_ON_ONCE(!queue_is_locked(q));
 454         __set_bit(flag, &q->queue_flags);
 455 }
 456
 457 static inline void queue_flag_clear_unlocked(unsigned int flag,
 458                                              struct request_queue *q)
 459 {
 460         __clear_bit(flag, &q->queue_flags);
 461 }
 462
 463 static inline int queue_in_flight(struct request_queue *q)
 464 {
 465         return q->in_flight[0] + q->in_flight[1];
 466 }
 467
 468 static inline void queue_flag_clear(unsigned int flag, struct request_queue *q)
 469 {
 470         WARN_ON_ONCE(!queue_is_locked(q));
 471         __clear_bit(flag, &q->queue_flags);
 472 }
 473
 474 #define blk_queue_plugged(q)    test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags)
 475 #define blk_queue_tagged(q)     test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags)
 476 #define blk_queue_stopped(q)    test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
 477 #define blk_queue_nomerges(q)   test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags)
 478 #define blk_queue_noxmerges(q)  \
 479         test_bit(QUEUE_FLAG_NOXMERGES, &(q)->queue_flags)
 480 #define blk_queue_nonrot(q)     test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags)
 481 #define blk_queue_io_stat(q)    test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags)
 482 #define blk_queue_add_random(q) test_bit(QUEUE_FLAG_ADD_RANDOM, &(q)->queue_flags)
 483 #define blk_queue_stackable(q)  \
 484         test_bit(QUEUE_FLAG_STACKABLE, &(q)->queue_flags)
 485 #define blk_queue_discard(q)    test_bit(QUEUE_FLAG_DISCARD, &(q)->queue_flags)
 486 #define blk_queue_secdiscard(q) (blk_queue_discard(q) && \
 487         test_bit(QUEUE_FLAG_SECDISCARD, &(q)->queue_flags))
 488
 489 #define blk_noretry_request(rq) \
 490         ((rq)->cmd_flags & (REQ_FAILFAST_DEV|REQ_FAILFAST_TRANSPORT| \
 491                              REQ_FAILFAST_DRIVER))
 492
 493 #define blk_account_rq(rq) \
 494         (((rq)->cmd_flags & REQ_STARTED) && \
 495          ((rq)->cmd_type == REQ_TYPE_FS || \
 496           ((rq)->cmd_flags & REQ_DISCARD)))
 497
 498 #define blk_pm_request(rq)      \
 499         ((rq)->cmd_type == REQ_TYPE_PM_SUSPEND || \
 500          (rq)->cmd_type == REQ_TYPE_PM_RESUME)
 501
 502 #define blk_rq_cpu_valid(rq)    ((rq)->cpu != -1)
 503 #define blk_bidi_rq(rq)         ((rq)->next_rq != NULL)
 504 /* rq->queuelist of dequeued request must be list_empty() */
 505 #define blk_queued_rq(rq)       (!list_empty(&(rq)->queuelist))
 506
 507 #define list_entry_rq(ptr)      list_entry((ptr), struct request, queuelist)
 508
 509 #define rq_data_dir(rq)         ((rq)->cmd_flags & 1)
 510
 511 static inline unsigned int blk_queue_cluster(struct request_queue *q)
 512 {
 513         return q->limits.cluster;
 514 }
 515
 516 /*
 517  * We regard a request as sync, if either a read or a sync write
 518  */
 519 static inline bool rw_is_sync(unsigned int rw_flags)
 520 {
 521         return !(rw_flags & REQ_WRITE) || (rw_flags & REQ_SYNC);
 522 }
 523
 524 static inline bool rq_is_sync(struct request *rq)
 525 {
 526         return rw_is_sync(rq->cmd_flags);
 527 }
 528
 529 static inline int blk_queue_full(struct request_queue *q, int sync)
 530 {
 531         if (sync)
 532                 return test_bit(QUEUE_FLAG_SYNCFULL, &q->queue_flags);
 533         return test_bit(QUEUE_FLAG_ASYNCFULL, &q->queue_flags);
 534 }
 535
 536 static inline void blk_set_queue_full(struct request_queue *q, int sync)
 537 {
 538         if (sync)
 539                 queue_flag_set(QUEUE_FLAG_SYNCFULL, q);
 540         else
 541                 queue_flag_set(QUEUE_FLAG_ASYNCFULL, q);
 542 }
 543
 544 static inline void blk_clear_queue_full(struct request_queue *q, int sync)
 545 {
 546         if (sync)
 547                 queue_flag_clear(QUEUE_FLAG_SYNCFULL, q);
 548         else
 549                 queue_flag_clear(QUEUE_FLAG_ASYNCFULL, q);
 550 }
 551
 552
 553 /*
 554  * mergeable request must not have _NOMERGE or _BARRIER bit set, nor may
 555  * it already be started by driver.
 556  */
 557 #define RQ_NOMERGE_FLAGS        \
 558         (REQ_NOMERGE | REQ_STARTED | REQ_SOFTBARRIER | REQ_FLUSH | REQ_FUA)
 559 #define rq_mergeable(rq)        \
 560         (!((rq)->cmd_flags & RQ_NOMERGE_FLAGS) && \
 561          (((rq)->cmd_flags & REQ_DISCARD) || \
 562           (rq)->cmd_type == REQ_TYPE_FS))
 563
 564 /*
 565  * q->prep_rq_fn return values
 566  */
 567 #define BLKPREP_OK              0       /* serve it */
 568 #define BLKPREP_KILL            1       /* fatal error, kill */
 569 #define BLKPREP_DEFER           2       /* leave on queue */
 570
 571 extern unsigned long blk_max_low_pfn, blk_max_pfn;
 572
 573 /*
 574  * standard bounce addresses:
 575  *
 576  * BLK_BOUNCE_HIGH      : bounce all highmem pages
 577  * BLK_BOUNCE_ANY       : don't bounce anything
 578  * BLK_BOUNCE_ISA       : bounce pages above ISA DMA boundary
 579  */
 580
 581 #if BITS_PER_LONG == 32
 582 #define BLK_BOUNCE_HIGH         ((u64)blk_max_low_pfn << PAGE_SHIFT)
 583 #else
 584 #define BLK_BOUNCE_HIGH         -1ULL
 585 #endif
 586 #define BLK_BOUNCE_ANY          (-1ULL)
 587 #define BLK_BOUNCE_ISA          (DMA_BIT_MASK(24))
 588
 589 /*
 590  * default timeout for SG_IO if none specified
 591  */
 592 #define BLK_DEFAULT_SG_TIMEOUT  (60 * HZ)
 593 #define BLK_MIN_SG_TIMEOUT      (7 * HZ)
 594
 595 #ifdef CONFIG_BOUNCE
 596 extern int init_emergency_isa_pool(void);
 597 extern void blk_queue_bounce(struct request_queue *q, struct bio **bio);
 598 #else
 599 static inline int init_emergency_isa_pool(void)
 600 {
 601         return 0;
 602 }
 603 static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio)
 604 {
 605 }
 606 #endif /* CONFIG_MMU */
 607
 608 struct rq_map_data {
 609         struct page **pages;
 610         int page_order;
 611         int nr_entries;
 612         unsigned long offset;
 613         int null_mapped;
 614         int from_user;
 615 };
 616
 617 struct req_iterator {
 618         int i;
 619         struct bio *bio;
 620 };
 621
 622 /* This should not be used directly - use rq_for_each_segment */
 623 #define for_each_bio(_bio)              \
 624         for (; _bio; _bio = _bio->bi_next)
 625 #define __rq_for_each_bio(_bio, rq)     \
 626         if ((rq->bio))                  \
 627                 for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next)
 628
 629 #define rq_for_each_segment(bvl, _rq, _iter)                    \
 630         __rq_for_each_bio(_iter.bio, _rq)                       \
 631                 bio_for_each_segment(bvl, _iter.bio, _iter.i)
 632
 633 #define rq_iter_last(rq, _iter)                                 \
 634                 (_iter.bio->bi_next == NULL && _iter.i == _iter.bio->bi_vcnt-1)
 635
 636 #ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
 637 # error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform"
 638 #endif
 639 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
 640 extern void rq_flush_dcache_pages(struct request *rq);
 641 #else
 642 static inline void rq_flush_dcache_pages(struct request *rq)
 643 {
 644 }
 645 #endif
 646
 647 extern int blk_register_queue(struct gendisk *disk);
 648 extern void blk_unregister_queue(struct gendisk *disk);
 649 extern void register_disk(struct gendisk *dev);
 650 extern void generic_make_request(struct bio *bio);
 651 extern void blk_rq_init(struct request_queue *q, struct request *rq);
 652 extern void blk_put_request(struct request *);
 653 extern void __blk_put_request(struct request_queue *, struct request *);
 654 extern struct request *blk_get_request(struct request_queue *, int, gfp_t);
 655 extern struct request *blk_make_request(struct request_queue *, struct bio *,
 656                                         gfp_t);
 657 extern void blk_insert_request(struct request_queue *, struct request *, int, void *);
 658 extern void blk_requeue_request(struct request_queue *, struct request *);
 659 extern void blk_add_request_payload(struct request *rq, struct page *page,
 660                 unsigned int len);
 661 extern int blk_rq_check_limits(struct request_queue *q, struct request *rq);
 662 extern int blk_lld_busy(struct request_queue *q);
 663 extern int blk_rq_prep_clone(struct request *rq, struct request *rq_src,
 664                              struct bio_set *bs, gfp_t gfp_mask,
 665                              int (*bio_ctr)(struct bio *, struct bio *, void *),
 666                              void *data);
 667 extern void blk_rq_unprep_clone(struct request *rq);
 668 extern int blk_insert_cloned_request(struct request_queue *q,
 669                                      struct request *rq);
 670 extern void blk_plug_device(struct request_queue *);
 671 extern void blk_plug_device_unlocked(struct request_queue *);
 672 extern int blk_remove_plug(struct request_queue *);
 673 extern void blk_recount_segments(struct request_queue *, struct bio *);
 674 extern int scsi_cmd_ioctl(struct request_queue *, struct gendisk *, fmode_t,
 675                           unsigned int, void __user *);
 676 extern int sg_scsi_ioctl(struct request_queue *, struct gendisk *, fmode_t,
 677                          struct scsi_ioctl_command __user *);
 678
 679 /*
 680  * A queue has just exitted congestion.  Note this in the global counter of
 681  * congested queues, and wake up anyone who was waiting for requests to be
 682  * put back.
 683  */
 684 static inline void blk_clear_queue_congested(struct request_queue *q, int sync)
 685 {
 686         clear_bdi_congested(&q->backing_dev_info, sync);
 687 }
 688
 689 /*
 690  * A queue has just entered congestion.  Flag that in the queue's VM-visible
 691  * state flags and increment the global gounter of congested queues.
 692  */
 693 static inline void blk_set_queue_congested(struct request_queue *q, int sync)
 694 {
 695         set_bdi_congested(&q->backing_dev_info, sync);
 696 }
 697
 698 extern void blk_start_queue(struct request_queue *q);
 699 extern void blk_stop_queue(struct request_queue *q);
 700 extern void blk_sync_queue(struct request_queue *q);
 701 extern void __blk_stop_queue(struct request_queue *q);
 702 extern void __blk_run_queue(struct request_queue *);
 703 extern void blk_run_queue(struct request_queue *);
 704 extern int blk_rq_map_user(struct request_queue *, struct request *,
 705                            struct rq_map_data *, void __user *, unsigned long,
 706                            gfp_t);
 707 extern int blk_rq_unmap_user(struct bio *);
 708 extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, unsigned int, gfp_t);
 709 extern int blk_rq_map_user_iov(struct request_queue *, struct request *,
 710                                struct rq_map_data *, struct sg_iovec *, int,
 711                                unsigned int, gfp_t);
 712 extern int blk_execute_rq(struct request_queue *, struct gendisk *,
 713                           struct request *, int);
 714 extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *,
 715                                   struct request *, int, rq_end_io_fn *);
 716 extern void blk_unplug(struct request_queue *q);
 717
 718 static inline struct request_queue *bdev_get_queue(struct block_device *bdev)
 719 {
 720         return bdev->bd_disk->queue;
 721 }
 722
 723 /*
 724  * blk_rq_pos()                 : the current sector
 725  * blk_rq_bytes()               : bytes left in the entire request
 726  * blk_rq_cur_bytes()           : bytes left in the current segment
 727  * blk_rq_err_bytes()           : bytes left till the next error boundary
 728  * blk_rq_sectors()             : sectors left in the entire request
 729  * blk_rq_cur_sectors()         : sectors left in the current segment
 730  */
 731 static inline sector_t blk_rq_pos(const struct request *rq)
 732 {
 733         return rq->__sector;
 734 }
 735
 736 static inline unsigned int blk_rq_bytes(const struct request *rq)
 737 {
 738         return rq->__data_len;
 739 }
 740
 741 static inline int blk_rq_cur_bytes(const struct request *rq)
 742 {
 743         return rq->bio ? bio_cur_bytes(rq->bio) : 0;
 744 }
 745
 746 extern unsigned int blk_rq_err_bytes(const struct request *rq);
 747
 748 static inline unsigned int blk_rq_sectors(const struct request *rq)
 749 {
 750         return blk_rq_bytes(rq) >> 9;
 751 }
 752
 753 static inline unsigned int blk_rq_cur_sectors(const struct request *rq)
 754 {
 755         return blk_rq_cur_bytes(rq) >> 9;
 756 }
 757
 758 /*
 759  * Request issue related functions.
 760  */
 761 extern struct request *blk_peek_request(struct request_queue *q);
 762 extern void blk_start_request(struct request *rq);
 763 extern struct request *blk_fetch_request(struct request_queue *q);
 764
 765 /*
 766  * Request completion related functions.
 767  *
 768  * blk_update_request() completes given number of bytes and updates
 769  * the request without completing it.
 770  *
 771  * blk_end_request() and friends.  __blk_end_request() must be called
 772  * with the request queue spinlock acquired.
 773  *
 774  * Several drivers define their own end_request and call
 775  * blk_end_request() for parts of the original function.
 776  * This prevents code duplication in drivers.
 777  */
 778 extern bool blk_update_request(struct request *rq, int error,
 779                                unsigned int nr_bytes);
 780 extern bool blk_end_request(struct request *rq, int error,
 781                             unsigned int nr_bytes);
 782 extern void blk_end_request_all(struct request *rq, int error);
 783 extern bool blk_end_request_cur(struct request *rq, int error);
 784 extern bool blk_end_request_err(struct request *rq, int error);
 785 extern bool __blk_end_request(struct request *rq, int error,
 786                               unsigned int nr_bytes);
 787 extern void __blk_end_request_all(struct request *rq, int error);
 788 extern bool __blk_end_request_cur(struct request *rq, int error);
 789 extern bool __blk_end_request_err(struct request *rq, int error);
 790
 791 extern void blk_complete_request(struct request *);
 792 extern void __blk_complete_request(struct request *);
 793 extern void blk_abort_request(struct request *);
 794 extern void blk_abort_queue(struct request_queue *);
 795 extern void blk_unprep_request(struct request *);
 796
 797 /*
 798  * Access functions for manipulating queue properties
 799  */
 800 extern struct request_queue *blk_init_queue_node(request_fn_proc *rfn,
 801                                         spinlock_t *lock, int node_id);
 802 extern struct request_queue *blk_init_allocated_queue_node(struct request_queue *,
 803                                                            request_fn_proc *,
 804                                                            spinlock_t *, int node_id);
 805 extern struct request_queue *blk_init_queue(request_fn_proc *, spinlock_t *);
 806 extern struct request_queue *blk_init_allocated_queue(struct request_queue *,
 807                                                       request_fn_proc *, spinlock_t *);
 808 extern void blk_cleanup_queue(struct request_queue *);
 809 extern void blk_queue_make_request(struct request_queue *, make_request_fn *);
 810 extern void blk_queue_bounce_limit(struct request_queue *, u64);
 811 extern void blk_limits_max_hw_sectors(struct queue_limits *, unsigned int);
 812 extern void blk_queue_max_hw_sectors(struct request_queue *, unsigned int);
 813 extern void blk_queue_max_segments(struct request_queue *, unsigned short);
 814 extern void blk_queue_max_segment_size(struct request_queue *, unsigned int);
 815 extern void blk_queue_max_discard_sectors(struct request_queue *q,
 816                 unsigned int max_discard_sectors);
 817 extern void blk_queue_logical_block_size(struct request_queue *, unsigned short);
 818 extern void blk_queue_physical_block_size(struct request_queue *, unsigned int);
 819 extern void blk_queue_alignment_offset(struct request_queue *q,
 820                                        unsigned int alignment);
 821 extern void blk_limits_io_min(struct queue_limits *limits, unsigned int min);
 822 extern void blk_queue_io_min(struct request_queue *q, unsigned int min);
 823 extern void blk_limits_io_opt(struct queue_limits *limits, unsigned int opt);
 824 extern void blk_queue_io_opt(struct request_queue *q, unsigned int opt);
 825 extern void blk_set_default_limits(struct queue_limits *lim);
 826 extern int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
 827                             sector_t offset);
 828 extern int bdev_stack_limits(struct queue_limits *t, struct block_device *bdev,
 829                             sector_t offset);
 830 extern void disk_stack_limits(struct gendisk *disk, struct block_device *bdev,
 831                               sector_t offset);
 832 extern void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b);
 833 extern void blk_queue_dma_pad(struct request_queue *, unsigned int);
 834 extern void blk_queue_update_dma_pad(struct request_queue *, unsigned int);
 835 extern int blk_queue_dma_drain(struct request_queue *q,
 836                                dma_drain_needed_fn *dma_drain_needed,
 837                                void *buf, unsigned int size);
 838 extern void blk_queue_lld_busy(struct request_queue *q, lld_busy_fn *fn);
 839 extern void blk_queue_segment_boundary(struct request_queue *, unsigned long);
 840 extern void blk_queue_prep_rq(struct request_queue *, prep_rq_fn *pfn);
 841 extern void blk_queue_unprep_rq(struct request_queue *, unprep_rq_fn *ufn);
 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_rq_timed_out(struct request_queue *, rq_timed_out_fn *);
 847 extern void blk_queue_rq_timeout(struct request_queue *, unsigned int);
 848 extern void blk_queue_flush(struct request_queue *q, unsigned int flush);
 849 extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev);
 850
 851 extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *);
 852 extern void blk_dump_rq_flags(struct request *, char *);
 853 extern void generic_unplug_device(struct request_queue *);
 854 extern long nr_blockdev_pages(void);
 855
 856 int blk_get_queue(struct request_queue *);
 857 struct request_queue *blk_alloc_queue(gfp_t);
 858 struct request_queue *blk_alloc_queue_node(gfp_t, int);
 859 extern void blk_put_queue(struct request_queue *);
 860
 861 /*
 862  * tag stuff
 863  */
 864 #define blk_rq_tagged(rq)               ((rq)->cmd_flags & REQ_QUEUED)
 865 extern int blk_queue_start_tag(struct request_queue *, struct request *);
 866 extern struct request *blk_queue_find_tag(struct request_queue *, int);
 867 extern void blk_queue_end_tag(struct request_queue *, struct request *);
 868 extern int blk_queue_init_tags(struct request_queue *, int, struct blk_queue_tag *);
 869 extern void blk_queue_free_tags(struct request_queue *);
 870 extern int blk_queue_resize_tags(struct request_queue *, int);
 871 extern void blk_queue_invalidate_tags(struct request_queue *);
 872 extern struct blk_queue_tag *blk_init_tags(int);
 873 extern void blk_free_tags(struct blk_queue_tag *);
 874
 875 static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt,
 876                                                 int tag)
 877 {
 878         if (unlikely(bqt == NULL || tag >= bqt->real_max_depth))
 879                 return NULL;
 880         return bqt->tag_index[tag];
 881 }
 882
 883 #define BLKDEV_DISCARD_SECURE  0x01    /* secure discard */
 884
 885 extern int blkdev_issue_flush(struct block_device *, gfp_t, sector_t *);
 886 extern int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
 887                 sector_t nr_sects, gfp_t gfp_mask, unsigned long flags);
 888 extern int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
 889                         sector_t nr_sects, gfp_t gfp_mask);
 890 static inline int sb_issue_discard(struct super_block *sb, sector_t block,
 891                 sector_t nr_blocks, gfp_t gfp_mask, unsigned long flags)
 892 {
 893         return blkdev_issue_discard(sb->s_bdev, block << (sb->s_blocksize_bits - 9),
 894                                     nr_blocks << (sb->s_blocksize_bits - 9),
 895                                     gfp_mask, flags);
 896 }
 897 static inline int sb_issue_zeroout(struct super_block *sb, sector_t block,
 898                 sector_t nr_blocks, gfp_t gfp_mask)
 899 {
 900         return blkdev_issue_zeroout(sb->s_bdev,
 901                                     block << (sb->s_blocksize_bits - 9),
 902                                     nr_blocks << (sb->s_blocksize_bits - 9),
 903                                     gfp_mask);
 904 }
 905
 906 extern int blk_verify_command(unsigned char *cmd, fmode_t has_write_perm);
 907
 908 enum blk_default_limits {
 909         BLK_MAX_SEGMENTS        = 128,
 910         BLK_SAFE_MAX_SECTORS    = 255,
 911         BLK_DEF_MAX_SECTORS     = 1024,
 912         BLK_MAX_SEGMENT_SIZE    = 65536,
 913         BLK_SEG_BOUNDARY_MASK   = 0xFFFFFFFFUL,
 914 };
 915
 916 #define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist)
 917
 918 static inline unsigned long queue_bounce_pfn(struct request_queue *q)
 919 {
 920         return q->limits.bounce_pfn;
 921 }
 922
 923 static inline unsigned long queue_segment_boundary(struct request_queue *q)
 924 {
 925         return q->limits.seg_boundary_mask;
 926 }
 927
 928 static inline unsigned int queue_max_sectors(struct request_queue *q)
 929 {
 930         return q->limits.max_sectors;
 931 }
 932
 933 static inline unsigned int queue_max_hw_sectors(struct request_queue *q)
 934 {
 935         return q->limits.max_hw_sectors;
 936 }
 937
 938 static inline unsigned short queue_max_segments(struct request_queue *q)
 939 {
 940         return q->limits.max_segments;
 941 }
 942
 943 static inline unsigned int queue_max_segment_size(struct request_queue *q)
 944 {
 945         return q->limits.max_segment_size;
 946 }
 947
 948 static inline unsigned short queue_logical_block_size(struct request_queue *q)
 949 {
 950         int retval = 512;
 951
 952         if (q && q->limits.logical_block_size)
 953                 retval = q->limits.logical_block_size;
 954
 955         return retval;
 956 }
 957
 958 static inline unsigned short bdev_logical_block_size(struct block_device *bdev)
 959 {
 960         return queue_logical_block_size(bdev_get_queue(bdev));
 961 }
 962
 963 static inline unsigned int queue_physical_block_size(struct request_queue *q)
 964 {
 965         return q->limits.physical_block_size;
 966 }
 967
 968 static inline unsigned int bdev_physical_block_size(struct block_device *bdev)
 969 {
 970         return queue_physical_block_size(bdev_get_queue(bdev));
 971 }
 972
 973 static inline unsigned int queue_io_min(struct request_queue *q)
 974 {
 975         return q->limits.io_min;
 976 }
 977
 978 static inline int bdev_io_min(struct block_device *bdev)
 979 {
 980         return queue_io_min(bdev_get_queue(bdev));
 981 }
 982
 983 static inline unsigned int queue_io_opt(struct request_queue *q)
 984 {
 985         return q->limits.io_opt;
 986 }
 987
 988 static inline int bdev_io_opt(struct block_device *bdev)
 989 {
 990         return queue_io_opt(bdev_get_queue(bdev));
 991 }
 992
 993 static inline int queue_alignment_offset(struct request_queue *q)
 994 {
 995         if (q->limits.misaligned)
 996                 return -1;
 997
 998         return q->limits.alignment_offset;
 999 }
1000
1001 static inline int queue_limit_alignment_offset(struct queue_limits *lim, sector_t sector)
1002 {
1003         unsigned int granularity = max(lim->physical_block_size, lim->io_min);
1004         unsigned int alignment = (sector << 9) & (granularity - 1);
1005
1006         return (granularity + lim->alignment_offset - alignment)
1007                 & (granularity - 1);
1008 }
1009
1010 static inline int bdev_alignment_offset(struct block_device *bdev)
1011 {
1012         struct request_queue *q = bdev_get_queue(bdev);
1013
1014         if (q->limits.misaligned)
1015                 return -1;
1016
1017         if (bdev != bdev->bd_contains)
1018                 return bdev->bd_part->alignment_offset;
1019
1020         return q->limits.alignment_offset;
1021 }
1022
1023 static inline int queue_discard_alignment(struct request_queue *q)
1024 {
1025         if (q->limits.discard_misaligned)
1026                 return -1;
1027
1028         return q->limits.discard_alignment;
1029 }
1030
1031 static inline int queue_limit_discard_alignment(struct queue_limits *lim, sector_t sector)
1032 {
1033         unsigned int alignment = (sector << 9) & (lim->discard_granularity - 1);
1034
1035         return (lim->discard_granularity + lim->discard_alignment - alignment)
1036                 & (lim->discard_granularity - 1);
1037 }
1038
1039 static inline unsigned int queue_discard_zeroes_data(struct request_queue *q)
1040 {
1041         if (q->limits.discard_zeroes_data == 1)
1042                 return 1;
1043
1044         return 0;
1045 }
1046
1047 static inline unsigned int bdev_discard_zeroes_data(struct block_device *bdev)
1048 {
1049         return queue_discard_zeroes_data(bdev_get_queue(bdev));
1050 }
1051
1052 static inline int queue_dma_alignment(struct request_queue *q)
1053 {
1054         return q ? q->dma_alignment : 511;
1055 }
1056
1057 static inline int blk_rq_aligned(struct request_queue *q, unsigned long addr,
1058                                  unsigned int len)
1059 {
1060         unsigned int alignment = queue_dma_alignment(q) | q->dma_pad_mask;
1061         return !(addr & alignment) && !(len & alignment);
1062 }
1063
1064 /* assumes size > 256 */
1065 static inline unsigned int blksize_bits(unsigned int size)
1066 {
1067         unsigned int bits = 8;
1068         do {
1069                 bits++;
1070                 size >>= 1;
1071         } while (size > 256);
1072         return bits;
1073 }
1074
1075 static inline unsigned int block_size(struct block_device *bdev)
1076 {
1077         return bdev->bd_block_size;
1078 }
1079
1080 typedef struct {struct page *v;} Sector;
1081
1082 unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *);
1083
1084 static inline void put_dev_sector(Sector p)
1085 {
1086         page_cache_release(p.v);
1087 }
1088
1089 struct work_struct;
1090 int kblockd_schedule_work(struct request_queue *q, struct work_struct *work);
1091 int kblockd_schedule_delayed_work(struct request_queue *q, struct delayed_work *dwork, unsigned long delay);
1092
1093 #ifdef CONFIG_BLK_CGROUP
1094 /*
1095  * This should not be using sched_clock(). A real patch is in progress
1096  * to fix this up, until that is in place we need to disable preemption
1097  * around sched_clock() in this function and set_io_start_time_ns().
1098  */
1099 static inline void set_start_time_ns(struct request *req)
1100 {
1101         preempt_disable();
1102         req->start_time_ns = sched_clock();
1103         preempt_enable();
1104 }
1105
1106 static inline void set_io_start_time_ns(struct request *req)
1107 {
1108         preempt_disable();
1109         req->io_start_time_ns = sched_clock();
1110         preempt_enable();
1111 }
1112
1113 static inline uint64_t rq_start_time_ns(struct request *req)
1114 {
1115         return req->start_time_ns;
1116 }
1117
1118 static inline uint64_t rq_io_start_time_ns(struct request *req)
1119 {
1120         return req->io_start_time_ns;
1121 }
1122 #else
1123 static inline void set_start_time_ns(struct request *req) {}
1124 static inline void set_io_start_time_ns(struct request *req) {}
1125 static inline uint64_t rq_start_time_ns(struct request *req)
1126 {
1127         return 0;
1128 }
1129 static inline uint64_t rq_io_start_time_ns(struct request *req)
1130 {
1131         return 0;
1132 }
1133 #endif
1134
1135 #ifdef CONFIG_BLK_DEV_THROTTLING
1136 extern int blk_throtl_init(struct request_queue *q);
1137 extern void blk_throtl_exit(struct request_queue *q);
1138 extern int blk_throtl_bio(struct request_queue *q, struct bio **bio);
1139 extern void throtl_schedule_delayed_work(struct request_queue *q, unsigned long delay);
1140 extern void throtl_shutdown_timer_wq(struct request_queue *q);
1141 #else /* CONFIG_BLK_DEV_THROTTLING */
1142 static inline int blk_throtl_bio(struct request_queue *q, struct bio **bio)
1143 {
1144         return 0;
1145 }
1146
1147 static inline int blk_throtl_init(struct request_queue *q) { return 0; }
1148 static inline int blk_throtl_exit(struct request_queue *q) { return 0; }
1149 static inline void throtl_schedule_delayed_work(struct request_queue *q, unsigned long delay) {}
1150 static inline void throtl_shutdown_timer_wq(struct request_queue *q) {}
1151 #endif /* CONFIG_BLK_DEV_THROTTLING */
1152
1153 #define MODULE_ALIAS_BLOCKDEV(major,minor) \
1154         MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor))
1155 #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \
1156         MODULE_ALIAS("block-major-" __stringify(major) "-*")
1157
1158 #if defined(CONFIG_BLK_DEV_INTEGRITY)
1159
1160 #define INTEGRITY_FLAG_READ     2       /* verify data integrity on read */
1161 #define INTEGRITY_FLAG_WRITE    4       /* generate data integrity on write */
1162
1163 struct blk_integrity_exchg {
1164         void                    *prot_buf;
1165         void                    *data_buf;
1166         sector_t                sector;
1167         unsigned int            data_size;
1168         unsigned short          sector_size;
1169         const char              *disk_name;
1170 };
1171
1172 typedef void (integrity_gen_fn) (struct blk_integrity_exchg *);
1173 typedef int (integrity_vrfy_fn) (struct blk_integrity_exchg *);
1174 typedef void (integrity_set_tag_fn) (void *, void *, unsigned int);
1175 typedef void (integrity_get_tag_fn) (void *, void *, unsigned int);
1176
1177 struct blk_integrity {
1178         integrity_gen_fn        *generate_fn;
1179         integrity_vrfy_fn       *verify_fn;
1180         integrity_set_tag_fn    *set_tag_fn;
1181         integrity_get_tag_fn    *get_tag_fn;
1182
1183         unsigned short          flags;
1184         unsigned short          tuple_size;
1185         unsigned short          sector_size;
1186         unsigned short          tag_size;
1187
1188         const char              *name;
1189
1190         struct kobject          kobj;
1191 };
1192
1193 extern int blk_integrity_register(struct gendisk *, struct blk_integrity *);
1194 extern void blk_integrity_unregister(struct gendisk *);
1195 extern int blk_integrity_compare(struct gendisk *, struct gendisk *);
1196 extern int blk_rq_map_integrity_sg(struct request_queue *, struct bio *,
1197                                    struct scatterlist *);
1198 extern int blk_rq_count_integrity_sg(struct request_queue *, struct bio *);
1199 extern int blk_integrity_merge_rq(struct request_queue *, struct request *,
1200                                   struct request *);
1201 extern int blk_integrity_merge_bio(struct request_queue *, struct request *,
1202                                    struct bio *);
1203
1204 static inline
1205 struct blk_integrity *bdev_get_integrity(struct block_device *bdev)
1206 {
1207         return bdev->bd_disk->integrity;
1208 }
1209
1210 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk)
1211 {
1212         return disk->integrity;
1213 }
1214
1215 static inline int blk_integrity_rq(struct request *rq)
1216 {
1217         if (rq->bio == NULL)
1218                 return 0;
1219
1220         return bio_integrity(rq->bio);
1221 }
1222
1223 static inline void blk_queue_max_integrity_segments(struct request_queue *q,
1224                                                     unsigned int segs)
1225 {
1226         q->limits.max_integrity_segments = segs;
1227 }
1228
1229 static inline unsigned short
1230 queue_max_integrity_segments(struct request_queue *q)
1231 {
1232         return q->limits.max_integrity_segments;
1233 }
1234
1235 #else /* CONFIG_BLK_DEV_INTEGRITY */
1236
1237 #define blk_integrity_rq(rq)                    (0)
1238 #define blk_rq_count_integrity_sg(a, b)         (0)
1239 #define blk_rq_map_integrity_sg(a, b, c)        (0)
1240 #define bdev_get_integrity(a)                   (0)
1241 #define blk_get_integrity(a)                    (0)
1242 #define blk_integrity_compare(a, b)             (0)
1243 #define blk_integrity_register(a, b)            (0)
1244 #define blk_integrity_unregister(a)             do { } while (0);
1245 #define blk_queue_max_integrity_segments(a, b)  do { } while (0);
1246 #define queue_max_integrity_segments(a)         (0)
1247 #define blk_integrity_merge_rq(a, b, c)         (0)
1248 #define blk_integrity_merge_bio(a, b, c)        (0)
1249
1250 #endif /* CONFIG_BLK_DEV_INTEGRITY */
1251
1252 struct block_device_operations {
1253         int (*open) (struct block_device *, fmode_t);
1254         int (*release) (struct gendisk *, fmode_t);
1255         int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1256         int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1257         int (*direct_access) (struct block_device *, sector_t,
1258                                                 void **, unsigned long *);
1259         int (*media_changed) (struct gendisk *);
1260         void (*unlock_native_capacity) (struct gendisk *);
1261         int (*revalidate_disk) (struct gendisk *);
1262         int (*getgeo)(struct block_device *, struct hd_geometry *);
1263         /* this callback is with swap_lock and sometimes page table lock held */
1264         void (*swap_slot_free_notify) (struct block_device *, unsigned long);
1265         struct module *owner;
1266 };
1267
1268 extern int __blkdev_driver_ioctl(struct block_device *, fmode_t, unsigned int,
1269                                  unsigned long);
1270 #else /* CONFIG_BLOCK */
1271 /*
1272  * stubs for when the block layer is configured out
1273  */
1274 #define buffer_heads_over_limit 0
1275
1276 static inline long nr_blockdev_pages(void)
1277 {
1278         return 0;
1279 }
1280
1281 #endif /* CONFIG_BLOCK */
1282
1283 #endif