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           no_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_CLUSTER      0       /* cluster several segments into 1 */
 384 #define QUEUE_FLAG_QUEUED       1       /* uses generic tag queueing */
 385 #define QUEUE_FLAG_STOPPED      2       /* queue is stopped */
 386 #define QUEUE_FLAG_SYNCFULL     3       /* read queue has been filled */
 387 #define QUEUE_FLAG_ASYNCFULL    4       /* write queue has been filled */
 388 #define QUEUE_FLAG_DEAD         5       /* queue being torn down */
 389 #define QUEUE_FLAG_REENTER      6       /* Re-entrancy avoidance */
 390 #define QUEUE_FLAG_PLUGGED      7       /* queue is plugged */
 391 #define QUEUE_FLAG_ELVSWITCH    8       /* don't use elevator, just do FIFO */
 392 #define QUEUE_FLAG_BIDI         9       /* queue supports bidi requests */
 393 #define QUEUE_FLAG_NOMERGES    10       /* disable merge attempts */
 394 #define QUEUE_FLAG_SAME_COMP   11       /* force complete on same CPU */
 395 #define QUEUE_FLAG_FAIL_IO     12       /* fake timeout */
 396 #define QUEUE_FLAG_STACKABLE   13       /* supports request stacking */
 397 #define QUEUE_FLAG_NONROT      14       /* non-rotational device (SSD) */
 398 #define QUEUE_FLAG_VIRT        QUEUE_FLAG_NONROT /* paravirt device */
 399 #define QUEUE_FLAG_IO_STAT     15       /* do IO stats */
 400 #define QUEUE_FLAG_DISCARD     16       /* supports DISCARD */
 401 #define QUEUE_FLAG_NOXMERGES   17       /* No extended merges */
 402 #define QUEUE_FLAG_ADD_RANDOM  18       /* Contributes to random pool */
 403 #define QUEUE_FLAG_SECDISCARD  19       /* supports SECDISCARD */
 404
 405 #define QUEUE_FLAG_DEFAULT      ((1 << QUEUE_FLAG_IO_STAT) |            \
 406                                  (1 << QUEUE_FLAG_CLUSTER) |            \
 407                                  (1 << QUEUE_FLAG_STACKABLE)    |       \
 408                                  (1 << QUEUE_FLAG_SAME_COMP)    |       \
 409                                  (1 << QUEUE_FLAG_ADD_RANDOM))
 410
 411 static inline int queue_is_locked(struct request_queue *q)
 412 {
 413 #ifdef CONFIG_SMP
 414         spinlock_t *lock = q->queue_lock;
 415         return lock && spin_is_locked(lock);
 416 #else
 417         return 1;
 418 #endif
 419 }
 420
 421 static inline void queue_flag_set_unlocked(unsigned int flag,
 422                                            struct request_queue *q)
 423 {
 424         __set_bit(flag, &q->queue_flags);
 425 }
 426
 427 static inline int queue_flag_test_and_clear(unsigned int flag,
 428                                             struct request_queue *q)
 429 {
 430         WARN_ON_ONCE(!queue_is_locked(q));
 431
 432         if (test_bit(flag, &q->queue_flags)) {
 433                 __clear_bit(flag, &q->queue_flags);
 434                 return 1;
 435         }
 436
 437         return 0;
 438 }
 439
 440 static inline int queue_flag_test_and_set(unsigned int flag,
 441                                           struct request_queue *q)
 442 {
 443         WARN_ON_ONCE(!queue_is_locked(q));
 444
 445         if (!test_bit(flag, &q->queue_flags)) {
 446                 __set_bit(flag, &q->queue_flags);
 447                 return 0;
 448         }
 449
 450         return 1;
 451 }
 452
 453 static inline void queue_flag_set(unsigned int flag, struct request_queue *q)
 454 {
 455         WARN_ON_ONCE(!queue_is_locked(q));
 456         __set_bit(flag, &q->queue_flags);
 457 }
 458
 459 static inline void queue_flag_clear_unlocked(unsigned int flag,
 460                                              struct request_queue *q)
 461 {
 462         __clear_bit(flag, &q->queue_flags);
 463 }
 464
 465 static inline int queue_in_flight(struct request_queue *q)
 466 {
 467         return q->in_flight[0] + q->in_flight[1];
 468 }
 469
 470 static inline void queue_flag_clear(unsigned int flag, struct request_queue *q)
 471 {
 472         WARN_ON_ONCE(!queue_is_locked(q));
 473         __clear_bit(flag, &q->queue_flags);
 474 }
 475
 476 #define blk_queue_plugged(q)    test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags)
 477 #define blk_queue_tagged(q)     test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags)
 478 #define blk_queue_stopped(q)    test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
 479 #define blk_queue_nomerges(q)   test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags)
 480 #define blk_queue_noxmerges(q)  \
 481         test_bit(QUEUE_FLAG_NOXMERGES, &(q)->queue_flags)
 482 #define blk_queue_nonrot(q)     test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags)
 483 #define blk_queue_io_stat(q)    test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags)
 484 #define blk_queue_add_random(q) test_bit(QUEUE_FLAG_ADD_RANDOM, &(q)->queue_flags)
 485 #define blk_queue_stackable(q)  \
 486         test_bit(QUEUE_FLAG_STACKABLE, &(q)->queue_flags)
 487 #define blk_queue_discard(q)    test_bit(QUEUE_FLAG_DISCARD, &(q)->queue_flags)
 488 #define blk_queue_secdiscard(q) (blk_queue_discard(q) && \
 489         test_bit(QUEUE_FLAG_SECDISCARD, &(q)->queue_flags))
 490
 491 #define blk_noretry_request(rq) \
 492         ((rq)->cmd_flags & (REQ_FAILFAST_DEV|REQ_FAILFAST_TRANSPORT| \
 493                              REQ_FAILFAST_DRIVER))
 494
 495 #define blk_account_rq(rq) \
 496         (((rq)->cmd_flags & REQ_STARTED) && \
 497          ((rq)->cmd_type == REQ_TYPE_FS || \
 498           ((rq)->cmd_flags & REQ_DISCARD)))
 499
 500 #define blk_pm_request(rq)      \
 501         ((rq)->cmd_type == REQ_TYPE_PM_SUSPEND || \
 502          (rq)->cmd_type == REQ_TYPE_PM_RESUME)
 503
 504 #define blk_rq_cpu_valid(rq)    ((rq)->cpu != -1)
 505 #define blk_bidi_rq(rq)         ((rq)->next_rq != NULL)
 506 /* rq->queuelist of dequeued request must be list_empty() */
 507 #define blk_queued_rq(rq)       (!list_empty(&(rq)->queuelist))
 508
 509 #define list_entry_rq(ptr)      list_entry((ptr), struct request, queuelist)
 510
 511 #define rq_data_dir(rq)         ((rq)->cmd_flags & 1)
 512
 513 /*
 514  * We regard a request as sync, if either a read or a sync write
 515  */
 516 static inline bool rw_is_sync(unsigned int rw_flags)
 517 {
 518         return !(rw_flags & REQ_WRITE) || (rw_flags & REQ_SYNC);
 519 }
 520
 521 static inline bool rq_is_sync(struct request *rq)
 522 {
 523         return rw_is_sync(rq->cmd_flags);
 524 }
 525
 526 static inline int blk_queue_full(struct request_queue *q, int sync)
 527 {
 528         if (sync)
 529                 return test_bit(QUEUE_FLAG_SYNCFULL, &q->queue_flags);
 530         return test_bit(QUEUE_FLAG_ASYNCFULL, &q->queue_flags);
 531 }
 532
 533 static inline void blk_set_queue_full(struct request_queue *q, int sync)
 534 {
 535         if (sync)
 536                 queue_flag_set(QUEUE_FLAG_SYNCFULL, q);
 537         else
 538                 queue_flag_set(QUEUE_FLAG_ASYNCFULL, q);
 539 }
 540
 541 static inline void blk_clear_queue_full(struct request_queue *q, int sync)
 542 {
 543         if (sync)
 544                 queue_flag_clear(QUEUE_FLAG_SYNCFULL, q);
 545         else
 546                 queue_flag_clear(QUEUE_FLAG_ASYNCFULL, q);
 547 }
 548
 549
 550 /*
 551  * mergeable request must not have _NOMERGE or _BARRIER bit set, nor may
 552  * it already be started by driver.
 553  */
 554 #define RQ_NOMERGE_FLAGS        \
 555         (REQ_NOMERGE | REQ_STARTED | REQ_SOFTBARRIER | REQ_FLUSH | REQ_FUA)
 556 #define rq_mergeable(rq)        \
 557         (!((rq)->cmd_flags & RQ_NOMERGE_FLAGS) && \
 558          (((rq)->cmd_flags & REQ_DISCARD) || \
 559           (rq)->cmd_type == REQ_TYPE_FS))
 560
 561 /*
 562  * q->prep_rq_fn return values
 563  */
 564 #define BLKPREP_OK              0       /* serve it */
 565 #define BLKPREP_KILL            1       /* fatal error, kill */
 566 #define BLKPREP_DEFER           2       /* leave on queue */
 567
 568 extern unsigned long blk_max_low_pfn, blk_max_pfn;
 569
 570 /*
 571  * standard bounce addresses:
 572  *
 573  * BLK_BOUNCE_HIGH      : bounce all highmem pages
 574  * BLK_BOUNCE_ANY       : don't bounce anything
 575  * BLK_BOUNCE_ISA       : bounce pages above ISA DMA boundary
 576  */
 577
 578 #if BITS_PER_LONG == 32
 579 #define BLK_BOUNCE_HIGH         ((u64)blk_max_low_pfn << PAGE_SHIFT)
 580 #else
 581 #define BLK_BOUNCE_HIGH         -1ULL
 582 #endif
 583 #define BLK_BOUNCE_ANY          (-1ULL)
 584 #define BLK_BOUNCE_ISA          (DMA_BIT_MASK(24))
 585
 586 /*
 587  * default timeout for SG_IO if none specified
 588  */
 589 #define BLK_DEFAULT_SG_TIMEOUT  (60 * HZ)
 590 #define BLK_MIN_SG_TIMEOUT      (7 * HZ)
 591
 592 #ifdef CONFIG_BOUNCE
 593 extern int init_emergency_isa_pool(void);
 594 extern void blk_queue_bounce(struct request_queue *q, struct bio **bio);
 595 #else
 596 static inline int init_emergency_isa_pool(void)
 597 {
 598         return 0;
 599 }
 600 static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio)
 601 {
 602 }
 603 #endif /* CONFIG_MMU */
 604
 605 struct rq_map_data {
 606         struct page **pages;
 607         int page_order;
 608         int nr_entries;
 609         unsigned long offset;
 610         int null_mapped;
 611         int from_user;
 612 };
 613
 614 struct req_iterator {
 615         int i;
 616         struct bio *bio;
 617 };
 618
 619 /* This should not be used directly - use rq_for_each_segment */
 620 #define for_each_bio(_bio)              \
 621         for (; _bio; _bio = _bio->bi_next)
 622 #define __rq_for_each_bio(_bio, rq)     \
 623         if ((rq->bio))                  \
 624                 for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next)
 625
 626 #define rq_for_each_segment(bvl, _rq, _iter)                    \
 627         __rq_for_each_bio(_iter.bio, _rq)                       \
 628                 bio_for_each_segment(bvl, _iter.bio, _iter.i)
 629
 630 #define rq_iter_last(rq, _iter)                                 \
 631                 (_iter.bio->bi_next == NULL && _iter.i == _iter.bio->bi_vcnt-1)
 632
 633 #ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
 634 # error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform"
 635 #endif
 636 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
 637 extern void rq_flush_dcache_pages(struct request *rq);
 638 #else
 639 static inline void rq_flush_dcache_pages(struct request *rq)
 640 {
 641 }
 642 #endif
 643
 644 extern int blk_register_queue(struct gendisk *disk);
 645 extern void blk_unregister_queue(struct gendisk *disk);
 646 extern void register_disk(struct gendisk *dev);
 647 extern void generic_make_request(struct bio *bio);
 648 extern void blk_rq_init(struct request_queue *q, struct request *rq);
 649 extern void blk_put_request(struct request *);
 650 extern void __blk_put_request(struct request_queue *, struct request *);
 651 extern struct request *blk_get_request(struct request_queue *, int, gfp_t);
 652 extern struct request *blk_make_request(struct request_queue *, struct bio *,
 653                                         gfp_t);
 654 extern void blk_insert_request(struct request_queue *, struct request *, int, void *);
 655 extern void blk_requeue_request(struct request_queue *, struct request *);
 656 extern void blk_add_request_payload(struct request *rq, struct page *page,
 657                 unsigned int len);
 658 extern int blk_rq_check_limits(struct request_queue *q, struct request *rq);
 659 extern int blk_lld_busy(struct request_queue *q);
 660 extern int blk_rq_prep_clone(struct request *rq, struct request *rq_src,
 661                              struct bio_set *bs, gfp_t gfp_mask,
 662                              int (*bio_ctr)(struct bio *, struct bio *, void *),
 663                              void *data);
 664 extern void blk_rq_unprep_clone(struct request *rq);
 665 extern int blk_insert_cloned_request(struct request_queue *q,
 666                                      struct request *rq);
 667 extern void blk_plug_device(struct request_queue *);
 668 extern void blk_plug_device_unlocked(struct request_queue *);
 669 extern int blk_remove_plug(struct request_queue *);
 670 extern void blk_recount_segments(struct request_queue *, struct bio *);
 671 extern int scsi_cmd_ioctl(struct request_queue *, struct gendisk *, fmode_t,
 672                           unsigned int, void __user *);
 673 extern int sg_scsi_ioctl(struct request_queue *, struct gendisk *, fmode_t,
 674                          struct scsi_ioctl_command __user *);
 675
 676 /*
 677  * A queue has just exitted congestion.  Note this in the global counter of
 678  * congested queues, and wake up anyone who was waiting for requests to be
 679  * put back.
 680  */
 681 static inline void blk_clear_queue_congested(struct request_queue *q, int sync)
 682 {
 683         clear_bdi_congested(&q->backing_dev_info, sync);
 684 }
 685
 686 /*
 687  * A queue has just entered congestion.  Flag that in the queue's VM-visible
 688  * state flags and increment the global gounter of congested queues.
 689  */
 690 static inline void blk_set_queue_congested(struct request_queue *q, int sync)
 691 {
 692         set_bdi_congested(&q->backing_dev_info, sync);
 693 }
 694
 695 extern void blk_start_queue(struct request_queue *q);
 696 extern void blk_stop_queue(struct request_queue *q);
 697 extern void blk_sync_queue(struct request_queue *q);
 698 extern void __blk_stop_queue(struct request_queue *q);
 699 extern void __blk_run_queue(struct request_queue *);
 700 extern void blk_run_queue(struct request_queue *);
 701 extern int blk_rq_map_user(struct request_queue *, struct request *,
 702                            struct rq_map_data *, void __user *, unsigned long,
 703                            gfp_t);
 704 extern int blk_rq_unmap_user(struct bio *);
 705 extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, unsigned int, gfp_t);
 706 extern int blk_rq_map_user_iov(struct request_queue *, struct request *,
 707                                struct rq_map_data *, struct sg_iovec *, int,
 708                                unsigned int, gfp_t);
 709 extern int blk_execute_rq(struct request_queue *, struct gendisk *,
 710                           struct request *, int);
 711 extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *,
 712                                   struct request *, int, rq_end_io_fn *);
 713 extern void blk_unplug(struct request_queue *q);
 714
 715 static inline struct request_queue *bdev_get_queue(struct block_device *bdev)
 716 {
 717         return bdev->bd_disk->queue;
 718 }
 719
 720 /*
 721  * blk_rq_pos()                 : the current sector
 722  * blk_rq_bytes()               : bytes left in the entire request
 723  * blk_rq_cur_bytes()           : bytes left in the current segment
 724  * blk_rq_err_bytes()           : bytes left till the next error boundary
 725  * blk_rq_sectors()             : sectors left in the entire request
 726  * blk_rq_cur_sectors()         : sectors left in the current segment
 727  */
 728 static inline sector_t blk_rq_pos(const struct request *rq)
 729 {
 730         return rq->__sector;
 731 }
 732
 733 static inline unsigned int blk_rq_bytes(const struct request *rq)
 734 {
 735         return rq->__data_len;
 736 }
 737
 738 static inline int blk_rq_cur_bytes(const struct request *rq)
 739 {
 740         return rq->bio ? bio_cur_bytes(rq->bio) : 0;
 741 }
 742
 743 extern unsigned int blk_rq_err_bytes(const struct request *rq);
 744
 745 static inline unsigned int blk_rq_sectors(const struct request *rq)
 746 {
 747         return blk_rq_bytes(rq) >> 9;
 748 }
 749
 750 static inline unsigned int blk_rq_cur_sectors(const struct request *rq)
 751 {
 752         return blk_rq_cur_bytes(rq) >> 9;
 753 }
 754
 755 /*
 756  * Request issue related functions.
 757  */
 758 extern struct request *blk_peek_request(struct request_queue *q);
 759 extern void blk_start_request(struct request *rq);
 760 extern struct request *blk_fetch_request(struct request_queue *q);
 761
 762 /*
 763  * Request completion related functions.
 764  *
 765  * blk_update_request() completes given number of bytes and updates
 766  * the request without completing it.
 767  *
 768  * blk_end_request() and friends.  __blk_end_request() must be called
 769  * with the request queue spinlock acquired.
 770  *
 771  * Several drivers define their own end_request and call
 772  * blk_end_request() for parts of the original function.
 773  * This prevents code duplication in drivers.
 774  */
 775 extern bool blk_update_request(struct request *rq, int error,
 776                                unsigned int nr_bytes);
 777 extern bool blk_end_request(struct request *rq, int error,
 778                             unsigned int nr_bytes);
 779 extern void blk_end_request_all(struct request *rq, int error);
 780 extern bool blk_end_request_cur(struct request *rq, int error);
 781 extern bool blk_end_request_err(struct request *rq, int error);
 782 extern bool __blk_end_request(struct request *rq, int error,
 783                               unsigned int nr_bytes);
 784 extern void __blk_end_request_all(struct request *rq, int error);
 785 extern bool __blk_end_request_cur(struct request *rq, int error);
 786 extern bool __blk_end_request_err(struct request *rq, int error);
 787
 788 extern void blk_complete_request(struct request *);
 789 extern void __blk_complete_request(struct request *);
 790 extern void blk_abort_request(struct request *);
 791 extern void blk_abort_queue(struct request_queue *);
 792 extern void blk_unprep_request(struct request *);
 793
 794 /*
 795  * Access functions for manipulating queue properties
 796  */
 797 extern struct request_queue *blk_init_queue_node(request_fn_proc *rfn,
 798                                         spinlock_t *lock, int node_id);
 799 extern struct request_queue *blk_init_allocated_queue_node(struct request_queue *,
 800                                                            request_fn_proc *,
 801                                                            spinlock_t *, int node_id);
 802 extern struct request_queue *blk_init_queue(request_fn_proc *, spinlock_t *);
 803 extern struct request_queue *blk_init_allocated_queue(struct request_queue *,
 804                                                       request_fn_proc *, spinlock_t *);
 805 extern void blk_cleanup_queue(struct request_queue *);
 806 extern void blk_queue_make_request(struct request_queue *, make_request_fn *);
 807 extern void blk_queue_bounce_limit(struct request_queue *, u64);
 808 extern void blk_queue_max_hw_sectors(struct request_queue *, unsigned int);
 809 extern void blk_queue_max_segments(struct request_queue *, unsigned short);
 810 extern void blk_queue_max_segment_size(struct request_queue *, unsigned int);
 811 extern void blk_queue_max_discard_sectors(struct request_queue *q,
 812                 unsigned int max_discard_sectors);
 813 extern void blk_queue_logical_block_size(struct request_queue *, unsigned short);
 814 extern void blk_queue_physical_block_size(struct request_queue *, unsigned int);
 815 extern void blk_queue_alignment_offset(struct request_queue *q,
 816                                        unsigned int alignment);
 817 extern void blk_limits_io_min(struct queue_limits *limits, unsigned int min);
 818 extern void blk_queue_io_min(struct request_queue *q, unsigned int min);
 819 extern void blk_limits_io_opt(struct queue_limits *limits, unsigned int opt);
 820 extern void blk_queue_io_opt(struct request_queue *q, unsigned int opt);
 821 extern void blk_set_default_limits(struct queue_limits *lim);
 822 extern int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
 823                             sector_t offset);
 824 extern int bdev_stack_limits(struct queue_limits *t, struct block_device *bdev,
 825                             sector_t offset);
 826 extern void disk_stack_limits(struct gendisk *disk, struct block_device *bdev,
 827                               sector_t offset);
 828 extern void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b);
 829 extern void blk_queue_dma_pad(struct request_queue *, unsigned int);
 830 extern void blk_queue_update_dma_pad(struct request_queue *, unsigned int);
 831 extern int blk_queue_dma_drain(struct request_queue *q,
 832                                dma_drain_needed_fn *dma_drain_needed,
 833                                void *buf, unsigned int size);
 834 extern void blk_queue_lld_busy(struct request_queue *q, lld_busy_fn *fn);
 835 extern void blk_queue_segment_boundary(struct request_queue *, unsigned long);
 836 extern void blk_queue_prep_rq(struct request_queue *, prep_rq_fn *pfn);
 837 extern void blk_queue_unprep_rq(struct request_queue *, unprep_rq_fn *ufn);
 838 extern void blk_queue_merge_bvec(struct request_queue *, merge_bvec_fn *);
 839 extern void blk_queue_dma_alignment(struct request_queue *, int);
 840 extern void blk_queue_update_dma_alignment(struct request_queue *, int);
 841 extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *);
 842 extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *);
 843 extern void blk_queue_rq_timeout(struct request_queue *, unsigned int);
 844 extern void blk_queue_flush(struct request_queue *q, unsigned int flush);
 845 extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev);
 846
 847 extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *);
 848 extern void blk_dump_rq_flags(struct request *, char *);
 849 extern void generic_unplug_device(struct request_queue *);
 850 extern long nr_blockdev_pages(void);
 851
 852 int blk_get_queue(struct request_queue *);
 853 struct request_queue *blk_alloc_queue(gfp_t);
 854 struct request_queue *blk_alloc_queue_node(gfp_t, int);
 855 extern void blk_put_queue(struct request_queue *);
 856
 857 /*
 858  * tag stuff
 859  */
 860 #define blk_rq_tagged(rq)               ((rq)->cmd_flags & REQ_QUEUED)
 861 extern int blk_queue_start_tag(struct request_queue *, struct request *);
 862 extern struct request *blk_queue_find_tag(struct request_queue *, int);
 863 extern void blk_queue_end_tag(struct request_queue *, struct request *);
 864 extern int blk_queue_init_tags(struct request_queue *, int, struct blk_queue_tag *);
 865 extern void blk_queue_free_tags(struct request_queue *);
 866 extern int blk_queue_resize_tags(struct request_queue *, int);
 867 extern void blk_queue_invalidate_tags(struct request_queue *);
 868 extern struct blk_queue_tag *blk_init_tags(int);
 869 extern void blk_free_tags(struct blk_queue_tag *);
 870
 871 static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt,
 872                                                 int tag)
 873 {
 874         if (unlikely(bqt == NULL || tag >= bqt->real_max_depth))
 875                 return NULL;
 876         return bqt->tag_index[tag];
 877 }
 878
 879 #define BLKDEV_DISCARD_SECURE  0x01    /* secure discard */
 880
 881 extern int blkdev_issue_flush(struct block_device *, gfp_t, sector_t *);
 882 extern int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
 883                 sector_t nr_sects, gfp_t gfp_mask, unsigned long flags);
 884 extern int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
 885                         sector_t nr_sects, gfp_t gfp_mask);
 886 static inline int sb_issue_discard(struct super_block *sb, sector_t block,
 887                 sector_t nr_blocks, gfp_t gfp_mask, unsigned long flags)
 888 {
 889         return blkdev_issue_discard(sb->s_bdev, block << (sb->s_blocksize_bits - 9),
 890                                     nr_blocks << (sb->s_blocksize_bits - 9),
 891                                     gfp_mask, flags);
 892 }
 893 static inline int sb_issue_zeroout(struct super_block *sb, sector_t block,
 894                 sector_t nr_blocks, gfp_t gfp_mask)
 895 {
 896         return blkdev_issue_zeroout(sb->s_bdev,
 897                                     block << (sb->s_blocksize_bits - 9),
 898                                     nr_blocks << (sb->s_blocksize_bits - 9),
 899                                     gfp_mask);
 900 }
 901
 902 extern int blk_verify_command(unsigned char *cmd, fmode_t has_write_perm);
 903
 904 enum blk_default_limits {
 905         BLK_MAX_SEGMENTS        = 128,
 906         BLK_SAFE_MAX_SECTORS    = 255,
 907         BLK_DEF_MAX_SECTORS     = 1024,
 908         BLK_MAX_SEGMENT_SIZE    = 65536,
 909         BLK_SEG_BOUNDARY_MASK   = 0xFFFFFFFFUL,
 910 };
 911
 912 #define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist)
 913
 914 static inline unsigned long queue_bounce_pfn(struct request_queue *q)
 915 {
 916         return q->limits.bounce_pfn;
 917 }
 918
 919 static inline unsigned long queue_segment_boundary(struct request_queue *q)
 920 {
 921         return q->limits.seg_boundary_mask;
 922 }
 923
 924 static inline unsigned int queue_max_sectors(struct request_queue *q)
 925 {
 926         return q->limits.max_sectors;
 927 }
 928
 929 static inline unsigned int queue_max_hw_sectors(struct request_queue *q)
 930 {
 931         return q->limits.max_hw_sectors;
 932 }
 933
 934 static inline unsigned short queue_max_segments(struct request_queue *q)
 935 {
 936         return q->limits.max_segments;
 937 }
 938
 939 static inline unsigned int queue_max_segment_size(struct request_queue *q)
 940 {
 941         return q->limits.max_segment_size;
 942 }
 943
 944 static inline unsigned short queue_logical_block_size(struct request_queue *q)
 945 {
 946         int retval = 512;
 947
 948         if (q && q->limits.logical_block_size)
 949                 retval = q->limits.logical_block_size;
 950
 951         return retval;
 952 }
 953
 954 static inline unsigned short bdev_logical_block_size(struct block_device *bdev)
 955 {
 956         return queue_logical_block_size(bdev_get_queue(bdev));
 957 }
 958
 959 static inline unsigned int queue_physical_block_size(struct request_queue *q)
 960 {
 961         return q->limits.physical_block_size;
 962 }
 963
 964 static inline unsigned int bdev_physical_block_size(struct block_device *bdev)
 965 {
 966         return queue_physical_block_size(bdev_get_queue(bdev));
 967 }
 968
 969 static inline unsigned int queue_io_min(struct request_queue *q)
 970 {
 971         return q->limits.io_min;
 972 }
 973
 974 static inline int bdev_io_min(struct block_device *bdev)
 975 {
 976         return queue_io_min(bdev_get_queue(bdev));
 977 }
 978
 979 static inline unsigned int queue_io_opt(struct request_queue *q)
 980 {
 981         return q->limits.io_opt;
 982 }
 983
 984 static inline int bdev_io_opt(struct block_device *bdev)
 985 {
 986         return queue_io_opt(bdev_get_queue(bdev));
 987 }
 988
 989 static inline int queue_alignment_offset(struct request_queue *q)
 990 {
 991         if (q->limits.misaligned)
 992                 return -1;
 993
 994         return q->limits.alignment_offset;
 995 }
 996
 997 static inline int queue_limit_alignment_offset(struct queue_limits *lim, sector_t sector)
 998 {
 999         unsigned int granularity = max(lim->physical_block_size, lim->io_min);
1000         unsigned int alignment = (sector << 9) & (granularity - 1);
1001
1002         return (granularity + lim->alignment_offset - alignment)
1003                 & (granularity - 1);
1004 }
1005
1006 static inline int bdev_alignment_offset(struct block_device *bdev)
1007 {
1008         struct request_queue *q = bdev_get_queue(bdev);
1009
1010         if (q->limits.misaligned)
1011                 return -1;
1012
1013         if (bdev != bdev->bd_contains)
1014                 return bdev->bd_part->alignment_offset;
1015
1016         return q->limits.alignment_offset;
1017 }
1018
1019 static inline int queue_discard_alignment(struct request_queue *q)
1020 {
1021         if (q->limits.discard_misaligned)
1022                 return -1;
1023
1024         return q->limits.discard_alignment;
1025 }
1026
1027 static inline int queue_limit_discard_alignment(struct queue_limits *lim, sector_t sector)
1028 {
1029         unsigned int alignment = (sector << 9) & (lim->discard_granularity - 1);
1030
1031         return (lim->discard_granularity + lim->discard_alignment - alignment)
1032                 & (lim->discard_granularity - 1);
1033 }
1034
1035 static inline unsigned int queue_discard_zeroes_data(struct request_queue *q)
1036 {
1037         if (q->limits.discard_zeroes_data == 1)
1038                 return 1;
1039
1040         return 0;
1041 }
1042
1043 static inline unsigned int bdev_discard_zeroes_data(struct block_device *bdev)
1044 {
1045         return queue_discard_zeroes_data(bdev_get_queue(bdev));
1046 }
1047
1048 static inline int queue_dma_alignment(struct request_queue *q)
1049 {
1050         return q ? q->dma_alignment : 511;
1051 }
1052
1053 static inline int blk_rq_aligned(struct request_queue *q, unsigned long addr,
1054                                  unsigned int len)
1055 {
1056         unsigned int alignment = queue_dma_alignment(q) | q->dma_pad_mask;
1057         return !(addr & alignment) && !(len & alignment);
1058 }
1059
1060 /* assumes size > 256 */
1061 static inline unsigned int blksize_bits(unsigned int size)
1062 {
1063         unsigned int bits = 8;
1064         do {
1065                 bits++;
1066                 size >>= 1;
1067         } while (size > 256);
1068         return bits;
1069 }
1070
1071 static inline unsigned int block_size(struct block_device *bdev)
1072 {
1073         return bdev->bd_block_size;
1074 }
1075
1076 typedef struct {struct page *v;} Sector;
1077
1078 unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *);
1079
1080 static inline void put_dev_sector(Sector p)
1081 {
1082         page_cache_release(p.v);
1083 }
1084
1085 struct work_struct;
1086 int kblockd_schedule_work(struct request_queue *q, struct work_struct *work);
1087 int kblockd_schedule_delayed_work(struct request_queue *q, struct delayed_work *dwork, unsigned long delay);
1088
1089 #ifdef CONFIG_BLK_CGROUP
1090 /*
1091  * This should not be using sched_clock(). A real patch is in progress
1092  * to fix this up, until that is in place we need to disable preemption
1093  * around sched_clock() in this function and set_io_start_time_ns().
1094  */
1095 static inline void set_start_time_ns(struct request *req)
1096 {
1097         preempt_disable();
1098         req->start_time_ns = sched_clock();
1099         preempt_enable();
1100 }
1101
1102 static inline void set_io_start_time_ns(struct request *req)
1103 {
1104         preempt_disable();
1105         req->io_start_time_ns = sched_clock();
1106         preempt_enable();
1107 }
1108
1109 static inline uint64_t rq_start_time_ns(struct request *req)
1110 {
1111         return req->start_time_ns;
1112 }
1113
1114 static inline uint64_t rq_io_start_time_ns(struct request *req)
1115 {
1116         return req->io_start_time_ns;
1117 }
1118 #else
1119 static inline void set_start_time_ns(struct request *req) {}
1120 static inline void set_io_start_time_ns(struct request *req) {}
1121 static inline uint64_t rq_start_time_ns(struct request *req)
1122 {
1123         return 0;
1124 }
1125 static inline uint64_t rq_io_start_time_ns(struct request *req)
1126 {
1127         return 0;
1128 }
1129 #endif
1130
1131 #ifdef CONFIG_BLK_DEV_THROTTLING
1132 extern int blk_throtl_init(struct request_queue *q);
1133 extern void blk_throtl_exit(struct request_queue *q);
1134 extern int blk_throtl_bio(struct request_queue *q, struct bio **bio);
1135 extern void throtl_schedule_delayed_work(struct request_queue *q, unsigned long delay);
1136 extern void throtl_shutdown_timer_wq(struct request_queue *q);
1137 #else /* CONFIG_BLK_DEV_THROTTLING */
1138 static inline int blk_throtl_bio(struct request_queue *q, struct bio **bio)
1139 {
1140         return 0;
1141 }
1142
1143 static inline int blk_throtl_init(struct request_queue *q) { return 0; }
1144 static inline int blk_throtl_exit(struct request_queue *q) { return 0; }
1145 static inline void throtl_schedule_delayed_work(struct request_queue *q, unsigned long delay) {}
1146 static inline void throtl_shutdown_timer_wq(struct request_queue *q) {}
1147 #endif /* CONFIG_BLK_DEV_THROTTLING */
1148
1149 #define MODULE_ALIAS_BLOCKDEV(major,minor) \
1150         MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor))
1151 #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \
1152         MODULE_ALIAS("block-major-" __stringify(major) "-*")
1153
1154 #if defined(CONFIG_BLK_DEV_INTEGRITY)
1155
1156 #define INTEGRITY_FLAG_READ     2       /* verify data integrity on read */
1157 #define INTEGRITY_FLAG_WRITE    4       /* generate data integrity on write */
1158
1159 struct blk_integrity_exchg {
1160         void                    *prot_buf;
1161         void                    *data_buf;
1162         sector_t                sector;
1163         unsigned int            data_size;
1164         unsigned short          sector_size;
1165         const char              *disk_name;
1166 };
1167
1168 typedef void (integrity_gen_fn) (struct blk_integrity_exchg *);
1169 typedef int (integrity_vrfy_fn) (struct blk_integrity_exchg *);
1170 typedef void (integrity_set_tag_fn) (void *, void *, unsigned int);
1171 typedef void (integrity_get_tag_fn) (void *, void *, unsigned int);
1172
1173 struct blk_integrity {
1174         integrity_gen_fn        *generate_fn;
1175         integrity_vrfy_fn       *verify_fn;
1176         integrity_set_tag_fn    *set_tag_fn;
1177         integrity_get_tag_fn    *get_tag_fn;
1178
1179         unsigned short          flags;
1180         unsigned short          tuple_size;
1181         unsigned short          sector_size;
1182         unsigned short          tag_size;
1183
1184         const char              *name;
1185
1186         struct kobject          kobj;
1187 };
1188
1189 extern int blk_integrity_register(struct gendisk *, struct blk_integrity *);
1190 extern void blk_integrity_unregister(struct gendisk *);
1191 extern int blk_integrity_compare(struct gendisk *, struct gendisk *);
1192 extern int blk_rq_map_integrity_sg(struct request_queue *, struct bio *,
1193                                    struct scatterlist *);
1194 extern int blk_rq_count_integrity_sg(struct request_queue *, struct bio *);
1195 extern int blk_integrity_merge_rq(struct request_queue *, struct request *,
1196                                   struct request *);
1197 extern int blk_integrity_merge_bio(struct request_queue *, struct request *,
1198                                    struct bio *);
1199
1200 static inline
1201 struct blk_integrity *bdev_get_integrity(struct block_device *bdev)
1202 {
1203         return bdev->bd_disk->integrity;
1204 }
1205
1206 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk)
1207 {
1208         return disk->integrity;
1209 }
1210
1211 static inline int blk_integrity_rq(struct request *rq)
1212 {
1213         if (rq->bio == NULL)
1214                 return 0;
1215
1216         return bio_integrity(rq->bio);
1217 }
1218
1219 static inline void blk_queue_max_integrity_segments(struct request_queue *q,
1220                                                     unsigned int segs)
1221 {
1222         q->limits.max_integrity_segments = segs;
1223 }
1224
1225 static inline unsigned short
1226 queue_max_integrity_segments(struct request_queue *q)
1227 {
1228         return q->limits.max_integrity_segments;
1229 }
1230
1231 #else /* CONFIG_BLK_DEV_INTEGRITY */
1232
1233 #define blk_integrity_rq(rq)                    (0)
1234 #define blk_rq_count_integrity_sg(a, b)         (0)
1235 #define blk_rq_map_integrity_sg(a, b, c)        (0)
1236 #define bdev_get_integrity(a)                   (0)
1237 #define blk_get_integrity(a)                    (0)
1238 #define blk_integrity_compare(a, b)             (0)
1239 #define blk_integrity_register(a, b)            (0)
1240 #define blk_integrity_unregister(a)             do { } while (0);
1241 #define blk_queue_max_integrity_segments(a, b)  do { } while (0);
1242 #define queue_max_integrity_segments(a)         (0)
1243 #define blk_integrity_merge_rq(a, b, c)         (0)
1244 #define blk_integrity_merge_bio(a, b, c)        (0)
1245
1246 #endif /* CONFIG_BLK_DEV_INTEGRITY */
1247
1248 struct block_device_operations {
1249         int (*open) (struct block_device *, fmode_t);
1250         int (*release) (struct gendisk *, fmode_t);
1251         int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1252         int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1253         int (*direct_access) (struct block_device *, sector_t,
1254                                                 void **, unsigned long *);
1255         int (*media_changed) (struct gendisk *);
1256         void (*unlock_native_capacity) (struct gendisk *);
1257         int (*revalidate_disk) (struct gendisk *);
1258         int (*getgeo)(struct block_device *, struct hd_geometry *);
1259         /* this callback is with swap_lock and sometimes page table lock held */
1260         void (*swap_slot_free_notify) (struct block_device *, unsigned long);
1261         struct module *owner;
1262 };
1263
1264 extern int __blkdev_driver_ioctl(struct block_device *, fmode_t, unsigned int,
1265                                  unsigned long);
1266 #else /* CONFIG_BLOCK */
1267 /*
1268  * stubs for when the block layer is configured out
1269  */
1270 #define buffer_heads_over_limit 0
1271
1272 static inline long nr_blockdev_pages(void)
1273 {
1274         return 0;
1275 }
1276
1277 #endif /* CONFIG_BLOCK */
1278
1279 #endif