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.  Flush requests are
 112          * never put on the IO scheduler. So let the flush fields share
 113          * space with the three elevator_private pointers.
 114          */
 115         union {
 116                 void *elevator_private[3];
 117                 struct {
 118                         unsigned int            seq;
 119                         struct list_head        list;
 120                 } flush;
 121         };
 122
 123         struct gendisk *rq_disk;
 124         struct hd_struct *part;
 125         unsigned long start_time;
 126 #ifdef CONFIG_BLK_CGROUP
 127         unsigned long long start_time_ns;
 128         unsigned long long io_start_time_ns;    /* when passed to hardware */
 129 #endif
 130         /* Number of scatter-gather DMA addr+len pairs after
 131          * physical address coalescing is performed.
 132          */
 133         unsigned short nr_phys_segments;
 134 #if defined(CONFIG_BLK_DEV_INTEGRITY)
 135         unsigned short nr_integrity_segments;
 136 #endif
 137
 138         unsigned short ioprio;
 139
 140         int ref_count;
 141
 142         void *special;          /* opaque pointer available for LLD use */
 143         char *buffer;           /* kaddr of the current segment if available */
 144
 145         int tag;
 146         int errors;
 147
 148         /*
 149          * when request is used as a packet command carrier
 150          */
 151         unsigned char __cmd[BLK_MAX_CDB];
 152         unsigned char *cmd;
 153         unsigned short cmd_len;
 154
 155         unsigned int extra_len; /* length of alignment and padding */
 156         unsigned int sense_len;
 157         unsigned int resid_len; /* residual count */
 158         void *sense;
 159
 160         unsigned long deadline;
 161         struct list_head timeout_list;
 162         unsigned int timeout;
 163         int retries;
 164
 165         /*
 166          * completion callback.
 167          */
 168         rq_end_io_fn *end_io;
 169         void *end_io_data;
 170
 171         /* for bidi */
 172         struct request *next_rq;
 173 };
 174
 175 static inline unsigned short req_get_ioprio(struct request *req)
 176 {
 177         return req->ioprio;
 178 }
 179
 180 /*
 181  * State information carried for REQ_TYPE_PM_SUSPEND and REQ_TYPE_PM_RESUME
 182  * requests. Some step values could eventually be made generic.
 183  */
 184 struct request_pm_state
 185 {
 186         /* PM state machine step value, currently driver specific */
 187         int     pm_step;
 188         /* requested PM state value (S1, S2, S3, S4, ...) */
 189         u32     pm_state;
 190         void*   data;           /* for driver use */
 191 };
 192
 193 #include <linux/elevator.h>
 194
 195 typedef void (request_fn_proc) (struct request_queue *q);
 196 typedef int (make_request_fn) (struct request_queue *q, struct bio *bio);
 197 typedef int (prep_rq_fn) (struct request_queue *, struct request *);
 198 typedef void (unprep_rq_fn) (struct request_queue *, struct request *);
 199 typedef void (unplug_fn) (struct request_queue *);
 200
 201 struct bio_vec;
 202 struct bvec_merge_data {
 203         struct block_device *bi_bdev;
 204         sector_t bi_sector;
 205         unsigned bi_size;
 206         unsigned long bi_rw;
 207 };
 208 typedef int (merge_bvec_fn) (struct request_queue *, struct bvec_merge_data *,
 209                              struct bio_vec *);
 210 typedef void (softirq_done_fn)(struct request *);
 211 typedef int (dma_drain_needed_fn)(struct request *);
 212 typedef int (lld_busy_fn) (struct request_queue *q);
 213
 214 enum blk_eh_timer_return {
 215         BLK_EH_NOT_HANDLED,
 216         BLK_EH_HANDLED,
 217         BLK_EH_RESET_TIMER,
 218 };
 219
 220 typedef enum blk_eh_timer_return (rq_timed_out_fn)(struct request *);
 221
 222 enum blk_queue_state {
 223         Queue_down,
 224         Queue_up,
 225 };
 226
 227 struct blk_queue_tag {
 228         struct request **tag_index;     /* map of busy tags */
 229         unsigned long *tag_map;         /* bit map of free/busy tags */
 230         int busy;                       /* current depth */
 231         int max_depth;                  /* what we will send to device */
 232         int real_max_depth;             /* what the array can hold */
 233         atomic_t refcnt;                /* map can be shared */
 234 };
 235
 236 #define BLK_SCSI_MAX_CMDS       (256)
 237 #define BLK_SCSI_CMD_PER_LONG   (BLK_SCSI_MAX_CMDS / (sizeof(long) * 8))
 238
 239 struct queue_limits {
 240         unsigned long           bounce_pfn;
 241         unsigned long           seg_boundary_mask;
 242
 243         unsigned int            max_hw_sectors;
 244         unsigned int            max_sectors;
 245         unsigned int            max_segment_size;
 246         unsigned int            physical_block_size;
 247         unsigned int            alignment_offset;
 248         unsigned int            io_min;
 249         unsigned int            io_opt;
 250         unsigned int            max_discard_sectors;
 251         unsigned int            discard_granularity;
 252         unsigned int            discard_alignment;
 253
 254         unsigned short          logical_block_size;
 255         unsigned short          max_segments;
 256         unsigned short          max_integrity_segments;
 257
 258         unsigned char           misaligned;
 259         unsigned char           discard_misaligned;
 260         unsigned char           cluster;
 261         signed char             discard_zeroes_data;
 262 };
 263
 264 struct request_queue
 265 {
 266         /*
 267          * Together with queue_head for cacheline sharing
 268          */
 269         struct list_head        queue_head;
 270         struct request          *last_merge;
 271         struct elevator_queue   *elevator;
 272
 273         /*
 274          * the queue request freelist, one for reads and one for writes
 275          */
 276         struct request_list     rq;
 277
 278         request_fn_proc         *request_fn;
 279         make_request_fn         *make_request_fn;
 280         prep_rq_fn              *prep_rq_fn;
 281         unprep_rq_fn            *unprep_rq_fn;
 282         unplug_fn               *unplug_fn;
 283         merge_bvec_fn           *merge_bvec_fn;
 284         softirq_done_fn         *softirq_done_fn;
 285         rq_timed_out_fn         *rq_timed_out_fn;
 286         dma_drain_needed_fn     *dma_drain_needed;
 287         lld_busy_fn             *lld_busy_fn;
 288
 289         /*
 290          * Dispatch queue sorting
 291          */
 292         sector_t                end_sector;
 293         struct request          *boundary_rq;
 294
 295         /*
 296          * Auto-unplugging state
 297          */
 298         struct timer_list       unplug_timer;
 299         int                     unplug_thresh;  /* After this many requests */
 300         unsigned long           unplug_delay;   /* After this many jiffies */
 301         struct work_struct      unplug_work;
 302
 303         /*
 304          * Delayed queue handling
 305          */
 306         struct delayed_work     delay_work;
 307
 308         struct backing_dev_info backing_dev_info;
 309
 310         /*
 311          * The queue owner gets to use this for whatever they like.
 312          * ll_rw_blk doesn't touch it.
 313          */
 314         void                    *queuedata;
 315
 316         /*
 317          * queue needs bounce pages for pages above this limit
 318          */
 319         gfp_t                   bounce_gfp;
 320
 321         /*
 322          * various queue flags, see QUEUE_* below
 323          */
 324         unsigned long           queue_flags;
 325
 326         /*
 327          * protects queue structures from reentrancy. ->__queue_lock should
 328          * _never_ be used directly, it is queue private. always use
 329          * ->queue_lock.
 330          */
 331         spinlock_t              __queue_lock;
 332         spinlock_t              *queue_lock;
 333
 334         /*
 335          * queue kobject
 336          */
 337         struct kobject kobj;
 338
 339         /*
 340          * queue settings
 341          */
 342         unsigned long           nr_requests;    /* Max # of requests */
 343         unsigned int            nr_congestion_on;
 344         unsigned int            nr_congestion_off;
 345         unsigned int            nr_batching;
 346
 347         void                    *dma_drain_buffer;
 348         unsigned int            dma_drain_size;
 349         unsigned int            dma_pad_mask;
 350         unsigned int            dma_alignment;
 351
 352         struct blk_queue_tag    *queue_tags;
 353         struct list_head        tag_busy_list;
 354
 355         unsigned int            nr_sorted;
 356         unsigned int            in_flight[2];
 357
 358         unsigned int            rq_timeout;
 359         struct timer_list       timeout;
 360         struct list_head        timeout_list;
 361
 362         struct queue_limits     limits;
 363
 364         /*
 365          * sg stuff
 366          */
 367         unsigned int            sg_timeout;
 368         unsigned int            sg_reserved_size;
 369         int                     node;
 370 #ifdef CONFIG_BLK_DEV_IO_TRACE
 371         struct blk_trace        *blk_trace;
 372 #endif
 373         /*
 374          * for flush operations
 375          */
 376         unsigned int            flush_flags;
 377         unsigned int            flush_pending_idx:1;
 378         unsigned int            flush_running_idx:1;
 379         unsigned long           flush_pending_since;
 380         struct list_head        flush_queue[2];
 381         struct list_head        flush_data_in_flight;
 382         struct request          flush_rq;
 383
 384         struct mutex            sysfs_lock;
 385
 386 #if defined(CONFIG_BLK_DEV_BSG)
 387         struct bsg_class_device bsg_dev;
 388 #endif
 389
 390 #ifdef CONFIG_BLK_DEV_THROTTLING
 391         /* Throttle data */
 392         struct throtl_data *td;
 393 #endif
 394 };
 395
 396 #define QUEUE_FLAG_QUEUED       1       /* uses generic tag queueing */
 397 #define QUEUE_FLAG_STOPPED      2       /* queue is stopped */
 398 #define QUEUE_FLAG_SYNCFULL     3       /* read queue has been filled */
 399 #define QUEUE_FLAG_ASYNCFULL    4       /* write queue has been filled */
 400 #define QUEUE_FLAG_DEAD         5       /* queue being torn down */
 401 #define QUEUE_FLAG_REENTER      6       /* Re-entrancy avoidance */
 402 #define QUEUE_FLAG_PLUGGED      7       /* queue is plugged */
 403 #define QUEUE_FLAG_ELVSWITCH    8       /* don't use elevator, just do FIFO */
 404 #define QUEUE_FLAG_BIDI         9       /* queue supports bidi requests */
 405 #define QUEUE_FLAG_NOMERGES    10       /* disable merge attempts */
 406 #define QUEUE_FLAG_SAME_COMP   11       /* force complete on same CPU */
 407 #define QUEUE_FLAG_FAIL_IO     12       /* fake timeout */
 408 #define QUEUE_FLAG_STACKABLE   13       /* supports request stacking */
 409 #define QUEUE_FLAG_NONROT      14       /* non-rotational device (SSD) */
 410 #define QUEUE_FLAG_VIRT        QUEUE_FLAG_NONROT /* paravirt device */
 411 #define QUEUE_FLAG_IO_STAT     15       /* do IO stats */
 412 #define QUEUE_FLAG_DISCARD     16       /* supports DISCARD */
 413 #define QUEUE_FLAG_NOXMERGES   17       /* No extended merges */
 414 #define QUEUE_FLAG_ADD_RANDOM  18       /* Contributes to random pool */
 415 #define QUEUE_FLAG_SECDISCARD  19       /* supports SECDISCARD */
 416
 417 #define QUEUE_FLAG_DEFAULT      ((1 << QUEUE_FLAG_IO_STAT) |            \
 418                                  (1 << QUEUE_FLAG_STACKABLE)    |       \
 419                                  (1 << QUEUE_FLAG_SAME_COMP)    |       \
 420                                  (1 << QUEUE_FLAG_ADD_RANDOM))
 421
 422 static inline int queue_is_locked(struct request_queue *q)
 423 {
 424 #ifdef CONFIG_SMP
 425         spinlock_t *lock = q->queue_lock;
 426         return lock && spin_is_locked(lock);
 427 #else
 428         return 1;
 429 #endif
 430 }
 431
 432 static inline void queue_flag_set_unlocked(unsigned int flag,
 433                                            struct request_queue *q)
 434 {
 435         __set_bit(flag, &q->queue_flags);
 436 }
 437
 438 static inline int queue_flag_test_and_clear(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                 __clear_bit(flag, &q->queue_flags);
 445                 return 1;
 446         }
 447
 448         return 0;
 449 }
 450
 451 static inline int queue_flag_test_and_set(unsigned int flag,
 452                                           struct request_queue *q)
 453 {
 454         WARN_ON_ONCE(!queue_is_locked(q));
 455
 456         if (!test_bit(flag, &q->queue_flags)) {
 457                 __set_bit(flag, &q->queue_flags);
 458                 return 0;
 459         }
 460
 461         return 1;
 462 }
 463
 464 static inline void queue_flag_set(unsigned int flag, struct request_queue *q)
 465 {
 466         WARN_ON_ONCE(!queue_is_locked(q));
 467         __set_bit(flag, &q->queue_flags);
 468 }
 469
 470 static inline void queue_flag_clear_unlocked(unsigned int flag,
 471                                              struct request_queue *q)
 472 {
 473         __clear_bit(flag, &q->queue_flags);
 474 }
 475
 476 static inline int queue_in_flight(struct request_queue *q)
 477 {
 478         return q->in_flight[0] + q->in_flight[1];
 479 }
 480
 481 static inline void queue_flag_clear(unsigned int flag, struct request_queue *q)
 482 {
 483         WARN_ON_ONCE(!queue_is_locked(q));
 484         __clear_bit(flag, &q->queue_flags);
 485 }
 486
 487 #define blk_queue_plugged(q)    test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags)
 488 #define blk_queue_tagged(q)     test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags)
 489 #define blk_queue_stopped(q)    test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
 490 #define blk_queue_nomerges(q)   test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags)
 491 #define blk_queue_noxmerges(q)  \
 492         test_bit(QUEUE_FLAG_NOXMERGES, &(q)->queue_flags)
 493 #define blk_queue_nonrot(q)     test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags)
 494 #define blk_queue_io_stat(q)    test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags)
 495 #define blk_queue_add_random(q) test_bit(QUEUE_FLAG_ADD_RANDOM, &(q)->queue_flags)
 496 #define blk_queue_stackable(q)  \
 497         test_bit(QUEUE_FLAG_STACKABLE, &(q)->queue_flags)
 498 #define blk_queue_discard(q)    test_bit(QUEUE_FLAG_DISCARD, &(q)->queue_flags)
 499 #define blk_queue_secdiscard(q) (blk_queue_discard(q) && \
 500         test_bit(QUEUE_FLAG_SECDISCARD, &(q)->queue_flags))
 501
 502 #define blk_noretry_request(rq) \
 503         ((rq)->cmd_flags & (REQ_FAILFAST_DEV|REQ_FAILFAST_TRANSPORT| \
 504                              REQ_FAILFAST_DRIVER))
 505
 506 #define blk_account_rq(rq) \
 507         (((rq)->cmd_flags & REQ_STARTED) && \
 508          ((rq)->cmd_type == REQ_TYPE_FS || \
 509           ((rq)->cmd_flags & REQ_DISCARD)))
 510
 511 #define blk_pm_request(rq)      \
 512         ((rq)->cmd_type == REQ_TYPE_PM_SUSPEND || \
 513          (rq)->cmd_type == REQ_TYPE_PM_RESUME)
 514
 515 #define blk_rq_cpu_valid(rq)    ((rq)->cpu != -1)
 516 #define blk_bidi_rq(rq)         ((rq)->next_rq != NULL)
 517 /* rq->queuelist of dequeued request must be list_empty() */
 518 #define blk_queued_rq(rq)       (!list_empty(&(rq)->queuelist))
 519
 520 #define list_entry_rq(ptr)      list_entry((ptr), struct request, queuelist)
 521
 522 #define rq_data_dir(rq)         ((rq)->cmd_flags & 1)
 523
 524 static inline unsigned int blk_queue_cluster(struct request_queue *q)
 525 {
 526         return q->limits.cluster;
 527 }
 528
 529 /*
 530  * We regard a request as sync, if either a read or a sync write
 531  */
 532 static inline bool rw_is_sync(unsigned int rw_flags)
 533 {
 534         return !(rw_flags & REQ_WRITE) || (rw_flags & REQ_SYNC);
 535 }
 536
 537 static inline bool rq_is_sync(struct request *rq)
 538 {
 539         return rw_is_sync(rq->cmd_flags);
 540 }
 541
 542 static inline int blk_queue_full(struct request_queue *q, int sync)
 543 {
 544         if (sync)
 545                 return test_bit(QUEUE_FLAG_SYNCFULL, &q->queue_flags);
 546         return test_bit(QUEUE_FLAG_ASYNCFULL, &q->queue_flags);
 547 }
 548
 549 static inline void blk_set_queue_full(struct request_queue *q, int sync)
 550 {
 551         if (sync)
 552                 queue_flag_set(QUEUE_FLAG_SYNCFULL, q);
 553         else
 554                 queue_flag_set(QUEUE_FLAG_ASYNCFULL, q);
 555 }
 556
 557 static inline void blk_clear_queue_full(struct request_queue *q, int sync)
 558 {
 559         if (sync)
 560                 queue_flag_clear(QUEUE_FLAG_SYNCFULL, q);
 561         else
 562                 queue_flag_clear(QUEUE_FLAG_ASYNCFULL, q);
 563 }
 564
 565
 566 /*
 567  * mergeable request must not have _NOMERGE or _BARRIER bit set, nor may
 568  * it already be started by driver.
 569  */
 570 #define RQ_NOMERGE_FLAGS        \
 571         (REQ_NOMERGE | REQ_STARTED | REQ_SOFTBARRIER | REQ_FLUSH | REQ_FUA)
 572 #define rq_mergeable(rq)        \
 573         (!((rq)->cmd_flags & RQ_NOMERGE_FLAGS) && \
 574          (((rq)->cmd_flags & REQ_DISCARD) || \
 575           (rq)->cmd_type == REQ_TYPE_FS))
 576
 577 /*
 578  * q->prep_rq_fn return values
 579  */
 580 #define BLKPREP_OK              0       /* serve it */
 581 #define BLKPREP_KILL            1       /* fatal error, kill */
 582 #define BLKPREP_DEFER           2       /* leave on queue */
 583
 584 extern unsigned long blk_max_low_pfn, blk_max_pfn;
 585
 586 /*
 587  * standard bounce addresses:
 588  *
 589  * BLK_BOUNCE_HIGH      : bounce all highmem pages
 590  * BLK_BOUNCE_ANY       : don't bounce anything
 591  * BLK_BOUNCE_ISA       : bounce pages above ISA DMA boundary
 592  */
 593
 594 #if BITS_PER_LONG == 32
 595 #define BLK_BOUNCE_HIGH         ((u64)blk_max_low_pfn << PAGE_SHIFT)
 596 #else
 597 #define BLK_BOUNCE_HIGH         -1ULL
 598 #endif
 599 #define BLK_BOUNCE_ANY          (-1ULL)
 600 #define BLK_BOUNCE_ISA          (DMA_BIT_MASK(24))
 601
 602 /*
 603  * default timeout for SG_IO if none specified
 604  */
 605 #define BLK_DEFAULT_SG_TIMEOUT  (60 * HZ)
 606 #define BLK_MIN_SG_TIMEOUT      (7 * HZ)
 607
 608 #ifdef CONFIG_BOUNCE
 609 extern int init_emergency_isa_pool(void);
 610 extern void blk_queue_bounce(struct request_queue *q, struct bio **bio);
 611 #else
 612 static inline int init_emergency_isa_pool(void)
 613 {
 614         return 0;
 615 }
 616 static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio)
 617 {
 618 }
 619 #endif /* CONFIG_MMU */
 620
 621 struct rq_map_data {
 622         struct page **pages;
 623         int page_order;
 624         int nr_entries;
 625         unsigned long offset;
 626         int null_mapped;
 627         int from_user;
 628 };
 629
 630 struct req_iterator {
 631         int i;
 632         struct bio *bio;
 633 };
 634
 635 /* This should not be used directly - use rq_for_each_segment */
 636 #define for_each_bio(_bio)              \
 637         for (; _bio; _bio = _bio->bi_next)
 638 #define __rq_for_each_bio(_bio, rq)     \
 639         if ((rq->bio))                  \
 640                 for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next)
 641
 642 #define rq_for_each_segment(bvl, _rq, _iter)                    \
 643         __rq_for_each_bio(_iter.bio, _rq)                       \
 644                 bio_for_each_segment(bvl, _iter.bio, _iter.i)
 645
 646 #define rq_iter_last(rq, _iter)                                 \
 647                 (_iter.bio->bi_next == NULL && _iter.i == _iter.bio->bi_vcnt-1)
 648
 649 #ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
 650 # error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform"
 651 #endif
 652 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
 653 extern void rq_flush_dcache_pages(struct request *rq);
 654 #else
 655 static inline void rq_flush_dcache_pages(struct request *rq)
 656 {
 657 }
 658 #endif
 659
 660 extern int blk_register_queue(struct gendisk *disk);
 661 extern void blk_unregister_queue(struct gendisk *disk);
 662 extern void generic_make_request(struct bio *bio);
 663 extern void blk_rq_init(struct request_queue *q, struct request *rq);
 664 extern void blk_put_request(struct request *);
 665 extern void __blk_put_request(struct request_queue *, struct request *);
 666 extern struct request *blk_get_request(struct request_queue *, int, gfp_t);
 667 extern struct request *blk_make_request(struct request_queue *, struct bio *,
 668                                         gfp_t);
 669 extern void blk_insert_request(struct request_queue *, struct request *, int, void *);
 670 extern void blk_requeue_request(struct request_queue *, struct request *);
 671 extern void blk_add_request_payload(struct request *rq, struct page *page,
 672                 unsigned int len);
 673 extern int blk_rq_check_limits(struct request_queue *q, struct request *rq);
 674 extern int blk_lld_busy(struct request_queue *q);
 675 extern int blk_rq_prep_clone(struct request *rq, struct request *rq_src,
 676                              struct bio_set *bs, gfp_t gfp_mask,
 677                              int (*bio_ctr)(struct bio *, struct bio *, void *),
 678                              void *data);
 679 extern void blk_rq_unprep_clone(struct request *rq);
 680 extern int blk_insert_cloned_request(struct request_queue *q,
 681                                      struct request *rq);
 682 extern void blk_plug_device(struct request_queue *);
 683 extern void blk_plug_device_unlocked(struct request_queue *);
 684 extern int blk_remove_plug(struct request_queue *);
 685 extern void blk_delay_queue(struct request_queue *, unsigned long);
 686 extern void blk_recount_segments(struct request_queue *, struct bio *);
 687 extern int scsi_cmd_ioctl(struct request_queue *, struct gendisk *, fmode_t,
 688                           unsigned int, void __user *);
 689 extern int sg_scsi_ioctl(struct request_queue *, struct gendisk *, fmode_t,
 690                          struct scsi_ioctl_command __user *);
 691
 692 /*
 693  * A queue has just exitted congestion.  Note this in the global counter of
 694  * congested queues, and wake up anyone who was waiting for requests to be
 695  * put back.
 696  */
 697 static inline void blk_clear_queue_congested(struct request_queue *q, int sync)
 698 {
 699         clear_bdi_congested(&q->backing_dev_info, sync);
 700 }
 701
 702 /*
 703  * A queue has just entered congestion.  Flag that in the queue's VM-visible
 704  * state flags and increment the global gounter of congested queues.
 705  */
 706 static inline void blk_set_queue_congested(struct request_queue *q, int sync)
 707 {
 708         set_bdi_congested(&q->backing_dev_info, sync);
 709 }
 710
 711 extern void blk_start_queue(struct request_queue *q);
 712 extern void blk_stop_queue(struct request_queue *q);
 713 extern void blk_sync_queue(struct request_queue *q);
 714 extern void __blk_stop_queue(struct request_queue *q);
 715 extern void __blk_run_queue(struct request_queue *);
 716 extern void blk_run_queue(struct request_queue *);
 717 extern int blk_rq_map_user(struct request_queue *, struct request *,
 718                            struct rq_map_data *, void __user *, unsigned long,
 719                            gfp_t);
 720 extern int blk_rq_unmap_user(struct bio *);
 721 extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, unsigned int, gfp_t);
 722 extern int blk_rq_map_user_iov(struct request_queue *, struct request *,
 723                                struct rq_map_data *, struct sg_iovec *, int,
 724                                unsigned int, gfp_t);
 725 extern int blk_execute_rq(struct request_queue *, struct gendisk *,
 726                           struct request *, int);
 727 extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *,
 728                                   struct request *, int, rq_end_io_fn *);
 729 extern void blk_unplug(struct request_queue *q);
 730
 731 static inline struct request_queue *bdev_get_queue(struct block_device *bdev)
 732 {
 733         return bdev->bd_disk->queue;
 734 }
 735
 736 /*
 737  * blk_rq_pos()                 : the current sector
 738  * blk_rq_bytes()               : bytes left in the entire request
 739  * blk_rq_cur_bytes()           : bytes left in the current segment
 740  * blk_rq_err_bytes()           : bytes left till the next error boundary
 741  * blk_rq_sectors()             : sectors left in the entire request
 742  * blk_rq_cur_sectors()         : sectors left in the current segment
 743  */
 744 static inline sector_t blk_rq_pos(const struct request *rq)
 745 {
 746         return rq->__sector;
 747 }
 748
 749 static inline unsigned int blk_rq_bytes(const struct request *rq)
 750 {
 751         return rq->__data_len;
 752 }
 753
 754 static inline int blk_rq_cur_bytes(const struct request *rq)
 755 {
 756         return rq->bio ? bio_cur_bytes(rq->bio) : 0;
 757 }
 758
 759 extern unsigned int blk_rq_err_bytes(const struct request *rq);
 760
 761 static inline unsigned int blk_rq_sectors(const struct request *rq)
 762 {
 763         return blk_rq_bytes(rq) >> 9;
 764 }
 765
 766 static inline unsigned int blk_rq_cur_sectors(const struct request *rq)
 767 {
 768         return blk_rq_cur_bytes(rq) >> 9;
 769 }
 770
 771 /*
 772  * Request issue related functions.
 773  */
 774 extern struct request *blk_peek_request(struct request_queue *q);
 775 extern void blk_start_request(struct request *rq);
 776 extern struct request *blk_fetch_request(struct request_queue *q);
 777
 778 /*
 779  * Request completion related functions.
 780  *
 781  * blk_update_request() completes given number of bytes and updates
 782  * the request without completing it.
 783  *
 784  * blk_end_request() and friends.  __blk_end_request() must be called
 785  * with the request queue spinlock acquired.
 786  *
 787  * Several drivers define their own end_request and call
 788  * blk_end_request() for parts of the original function.
 789  * This prevents code duplication in drivers.
 790  */
 791 extern bool blk_update_request(struct request *rq, int error,
 792                                unsigned int nr_bytes);
 793 extern bool blk_end_request(struct request *rq, int error,
 794                             unsigned int nr_bytes);
 795 extern void blk_end_request_all(struct request *rq, int error);
 796 extern bool blk_end_request_cur(struct request *rq, int error);
 797 extern bool blk_end_request_err(struct request *rq, int error);
 798 extern bool __blk_end_request(struct request *rq, int error,
 799                               unsigned int nr_bytes);
 800 extern void __blk_end_request_all(struct request *rq, int error);
 801 extern bool __blk_end_request_cur(struct request *rq, int error);
 802 extern bool __blk_end_request_err(struct request *rq, int error);
 803
 804 extern void blk_complete_request(struct request *);
 805 extern void __blk_complete_request(struct request *);
 806 extern void blk_abort_request(struct request *);
 807 extern void blk_abort_queue(struct request_queue *);
 808 extern void blk_unprep_request(struct request *);
 809
 810 /*
 811  * Access functions for manipulating queue properties
 812  */
 813 extern struct request_queue *blk_init_queue_node(request_fn_proc *rfn,
 814                                         spinlock_t *lock, int node_id);
 815 extern struct request_queue *blk_init_allocated_queue_node(struct request_queue *,
 816                                                            request_fn_proc *,
 817                                                            spinlock_t *, int node_id);
 818 extern struct request_queue *blk_init_queue(request_fn_proc *, spinlock_t *);
 819 extern struct request_queue *blk_init_allocated_queue(struct request_queue *,
 820                                                       request_fn_proc *, spinlock_t *);
 821 extern void blk_cleanup_queue(struct request_queue *);
 822 extern void blk_queue_make_request(struct request_queue *, make_request_fn *);
 823 extern void blk_queue_bounce_limit(struct request_queue *, u64);
 824 extern void blk_limits_max_hw_sectors(struct queue_limits *, unsigned int);
 825 extern void blk_queue_max_hw_sectors(struct request_queue *, unsigned int);
 826 extern void blk_queue_max_segments(struct request_queue *, unsigned short);
 827 extern void blk_queue_max_segment_size(struct request_queue *, unsigned int);
 828 extern void blk_queue_max_discard_sectors(struct request_queue *q,
 829                 unsigned int max_discard_sectors);
 830 extern void blk_queue_logical_block_size(struct request_queue *, unsigned short);
 831 extern void blk_queue_physical_block_size(struct request_queue *, unsigned int);
 832 extern void blk_queue_alignment_offset(struct request_queue *q,
 833                                        unsigned int alignment);
 834 extern void blk_limits_io_min(struct queue_limits *limits, unsigned int min);
 835 extern void blk_queue_io_min(struct request_queue *q, unsigned int min);
 836 extern void blk_limits_io_opt(struct queue_limits *limits, unsigned int opt);
 837 extern void blk_queue_io_opt(struct request_queue *q, unsigned int opt);
 838 extern void blk_set_default_limits(struct queue_limits *lim);
 839 extern int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
 840                             sector_t offset);
 841 extern int bdev_stack_limits(struct queue_limits *t, struct block_device *bdev,
 842                             sector_t offset);
 843 extern void disk_stack_limits(struct gendisk *disk, struct block_device *bdev,
 844                               sector_t offset);
 845 extern void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b);
 846 extern void blk_queue_dma_pad(struct request_queue *, unsigned int);
 847 extern void blk_queue_update_dma_pad(struct request_queue *, unsigned int);
 848 extern int blk_queue_dma_drain(struct request_queue *q,
 849                                dma_drain_needed_fn *dma_drain_needed,
 850                                void *buf, unsigned int size);
 851 extern void blk_queue_lld_busy(struct request_queue *q, lld_busy_fn *fn);
 852 extern void blk_queue_segment_boundary(struct request_queue *, unsigned long);
 853 extern void blk_queue_prep_rq(struct request_queue *, prep_rq_fn *pfn);
 854 extern void blk_queue_unprep_rq(struct request_queue *, unprep_rq_fn *ufn);
 855 extern void blk_queue_merge_bvec(struct request_queue *, merge_bvec_fn *);
 856 extern void blk_queue_dma_alignment(struct request_queue *, int);
 857 extern void blk_queue_update_dma_alignment(struct request_queue *, int);
 858 extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *);
 859 extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *);
 860 extern void blk_queue_rq_timeout(struct request_queue *, unsigned int);
 861 extern void blk_queue_flush(struct request_queue *q, unsigned int flush);
 862 extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev);
 863
 864 extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *);
 865 extern void blk_dump_rq_flags(struct request *, char *);
 866 extern void generic_unplug_device(struct request_queue *);
 867 extern long nr_blockdev_pages(void);
 868
 869 int blk_get_queue(struct request_queue *);
 870 struct request_queue *blk_alloc_queue(gfp_t);
 871 struct request_queue *blk_alloc_queue_node(gfp_t, int);
 872 extern void blk_put_queue(struct request_queue *);
 873
 874 /*
 875  * tag stuff
 876  */
 877 #define blk_rq_tagged(rq)               ((rq)->cmd_flags & REQ_QUEUED)
 878 extern int blk_queue_start_tag(struct request_queue *, struct request *);
 879 extern struct request *blk_queue_find_tag(struct request_queue *, int);
 880 extern void blk_queue_end_tag(struct request_queue *, struct request *);
 881 extern int blk_queue_init_tags(struct request_queue *, int, struct blk_queue_tag *);
 882 extern void blk_queue_free_tags(struct request_queue *);
 883 extern int blk_queue_resize_tags(struct request_queue *, int);
 884 extern void blk_queue_invalidate_tags(struct request_queue *);
 885 extern struct blk_queue_tag *blk_init_tags(int);
 886 extern void blk_free_tags(struct blk_queue_tag *);
 887
 888 static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt,
 889                                                 int tag)
 890 {
 891         if (unlikely(bqt == NULL || tag >= bqt->real_max_depth))
 892                 return NULL;
 893         return bqt->tag_index[tag];
 894 }
 895
 896 #define BLKDEV_DISCARD_SECURE  0x01    /* secure discard */
 897
 898 extern int blkdev_issue_flush(struct block_device *, gfp_t, sector_t *);
 899 extern int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
 900                 sector_t nr_sects, gfp_t gfp_mask, unsigned long flags);
 901 extern int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
 902                         sector_t nr_sects, gfp_t gfp_mask);
 903 static inline int sb_issue_discard(struct super_block *sb, sector_t block,
 904                 sector_t nr_blocks, gfp_t gfp_mask, unsigned long flags)
 905 {
 906         return blkdev_issue_discard(sb->s_bdev, block << (sb->s_blocksize_bits - 9),
 907                                     nr_blocks << (sb->s_blocksize_bits - 9),
 908                                     gfp_mask, flags);
 909 }
 910 static inline int sb_issue_zeroout(struct super_block *sb, sector_t block,
 911                 sector_t nr_blocks, gfp_t gfp_mask)
 912 {
 913         return blkdev_issue_zeroout(sb->s_bdev,
 914                                     block << (sb->s_blocksize_bits - 9),
 915                                     nr_blocks << (sb->s_blocksize_bits - 9),
 916                                     gfp_mask);
 917 }
 918
 919 extern int blk_verify_command(unsigned char *cmd, fmode_t has_write_perm);
 920
 921 enum blk_default_limits {
 922         BLK_MAX_SEGMENTS        = 128,
 923         BLK_SAFE_MAX_SECTORS    = 255,
 924         BLK_DEF_MAX_SECTORS     = 1024,
 925         BLK_MAX_SEGMENT_SIZE    = 65536,
 926         BLK_SEG_BOUNDARY_MASK   = 0xFFFFFFFFUL,
 927 };
 928
 929 #define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist)
 930
 931 static inline unsigned long queue_bounce_pfn(struct request_queue *q)
 932 {
 933         return q->limits.bounce_pfn;
 934 }
 935
 936 static inline unsigned long queue_segment_boundary(struct request_queue *q)
 937 {
 938         return q->limits.seg_boundary_mask;
 939 }
 940
 941 static inline unsigned int queue_max_sectors(struct request_queue *q)
 942 {
 943         return q->limits.max_sectors;
 944 }
 945
 946 static inline unsigned int queue_max_hw_sectors(struct request_queue *q)
 947 {
 948         return q->limits.max_hw_sectors;
 949 }
 950
 951 static inline unsigned short queue_max_segments(struct request_queue *q)
 952 {
 953         return q->limits.max_segments;
 954 }
 955
 956 static inline unsigned int queue_max_segment_size(struct request_queue *q)
 957 {
 958         return q->limits.max_segment_size;
 959 }
 960
 961 static inline unsigned short queue_logical_block_size(struct request_queue *q)
 962 {
 963         int retval = 512;
 964
 965         if (q && q->limits.logical_block_size)
 966                 retval = q->limits.logical_block_size;
 967
 968         return retval;
 969 }
 970
 971 static inline unsigned short bdev_logical_block_size(struct block_device *bdev)
 972 {
 973         return queue_logical_block_size(bdev_get_queue(bdev));
 974 }
 975
 976 static inline unsigned int queue_physical_block_size(struct request_queue *q)
 977 {
 978         return q->limits.physical_block_size;
 979 }
 980
 981 static inline unsigned int bdev_physical_block_size(struct block_device *bdev)
 982 {
 983         return queue_physical_block_size(bdev_get_queue(bdev));
 984 }
 985
 986 static inline unsigned int queue_io_min(struct request_queue *q)
 987 {
 988         return q->limits.io_min;
 989 }
 990
 991 static inline int bdev_io_min(struct block_device *bdev)
 992 {
 993         return queue_io_min(bdev_get_queue(bdev));
 994 }
 995
 996 static inline unsigned int queue_io_opt(struct request_queue *q)
 997 {
 998         return q->limits.io_opt;
 999 }
1000
1001 static inline int bdev_io_opt(struct block_device *bdev)
1002 {
1003         return queue_io_opt(bdev_get_queue(bdev));
1004 }
1005
1006 static inline int queue_alignment_offset(struct request_queue *q)
1007 {
1008         if (q->limits.misaligned)
1009                 return -1;
1010
1011         return q->limits.alignment_offset;
1012 }
1013
1014 static inline int queue_limit_alignment_offset(struct queue_limits *lim, sector_t sector)
1015 {
1016         unsigned int granularity = max(lim->physical_block_size, lim->io_min);
1017         unsigned int alignment = (sector << 9) & (granularity - 1);
1018
1019         return (granularity + lim->alignment_offset - alignment)
1020                 & (granularity - 1);
1021 }
1022
1023 static inline int bdev_alignment_offset(struct block_device *bdev)
1024 {
1025         struct request_queue *q = bdev_get_queue(bdev);
1026
1027         if (q->limits.misaligned)
1028                 return -1;
1029
1030         if (bdev != bdev->bd_contains)
1031                 return bdev->bd_part->alignment_offset;
1032
1033         return q->limits.alignment_offset;
1034 }
1035
1036 static inline int queue_discard_alignment(struct request_queue *q)
1037 {
1038         if (q->limits.discard_misaligned)
1039                 return -1;
1040
1041         return q->limits.discard_alignment;
1042 }
1043
1044 static inline int queue_limit_discard_alignment(struct queue_limits *lim, sector_t sector)
1045 {
1046         unsigned int alignment = (sector << 9) & (lim->discard_granularity - 1);
1047
1048         return (lim->discard_granularity + lim->discard_alignment - alignment)
1049                 & (lim->discard_granularity - 1);
1050 }
1051
1052 static inline unsigned int queue_discard_zeroes_data(struct request_queue *q)
1053 {
1054         if (q->limits.discard_zeroes_data == 1)
1055                 return 1;
1056
1057         return 0;
1058 }
1059
1060 static inline unsigned int bdev_discard_zeroes_data(struct block_device *bdev)
1061 {
1062         return queue_discard_zeroes_data(bdev_get_queue(bdev));
1063 }
1064
1065 static inline int queue_dma_alignment(struct request_queue *q)
1066 {
1067         return q ? q->dma_alignment : 511;
1068 }
1069
1070 static inline int blk_rq_aligned(struct request_queue *q, unsigned long addr,
1071                                  unsigned int len)
1072 {
1073         unsigned int alignment = queue_dma_alignment(q) | q->dma_pad_mask;
1074         return !(addr & alignment) && !(len & alignment);
1075 }
1076
1077 /* assumes size > 256 */
1078 static inline unsigned int blksize_bits(unsigned int size)
1079 {
1080         unsigned int bits = 8;
1081         do {
1082                 bits++;
1083                 size >>= 1;
1084         } while (size > 256);
1085         return bits;
1086 }
1087
1088 static inline unsigned int block_size(struct block_device *bdev)
1089 {
1090         return bdev->bd_block_size;
1091 }
1092
1093 typedef struct {struct page *v;} Sector;
1094
1095 unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *);
1096
1097 static inline void put_dev_sector(Sector p)
1098 {
1099         page_cache_release(p.v);
1100 }
1101
1102 struct work_struct;
1103 int kblockd_schedule_work(struct request_queue *q, struct work_struct *work);
1104 int kblockd_schedule_delayed_work(struct request_queue *q, struct delayed_work *dwork, unsigned long delay);
1105
1106 #ifdef CONFIG_BLK_CGROUP
1107 /*
1108  * This should not be using sched_clock(). A real patch is in progress
1109  * to fix this up, until that is in place we need to disable preemption
1110  * around sched_clock() in this function and set_io_start_time_ns().
1111  */
1112 static inline void set_start_time_ns(struct request *req)
1113 {
1114         preempt_disable();
1115         req->start_time_ns = sched_clock();
1116         preempt_enable();
1117 }
1118
1119 static inline void set_io_start_time_ns(struct request *req)
1120 {
1121         preempt_disable();
1122         req->io_start_time_ns = sched_clock();
1123         preempt_enable();
1124 }
1125
1126 static inline uint64_t rq_start_time_ns(struct request *req)
1127 {
1128         return req->start_time_ns;
1129 }
1130
1131 static inline uint64_t rq_io_start_time_ns(struct request *req)
1132 {
1133         return req->io_start_time_ns;
1134 }
1135 #else
1136 static inline void set_start_time_ns(struct request *req) {}
1137 static inline void set_io_start_time_ns(struct request *req) {}
1138 static inline uint64_t rq_start_time_ns(struct request *req)
1139 {
1140         return 0;
1141 }
1142 static inline uint64_t rq_io_start_time_ns(struct request *req)
1143 {
1144         return 0;
1145 }
1146 #endif
1147
1148 #ifdef CONFIG_BLK_DEV_THROTTLING
1149 extern int blk_throtl_init(struct request_queue *q);
1150 extern void blk_throtl_exit(struct request_queue *q);
1151 extern int blk_throtl_bio(struct request_queue *q, struct bio **bio);
1152 extern void throtl_schedule_delayed_work(struct request_queue *q, unsigned long delay);
1153 extern void throtl_shutdown_timer_wq(struct request_queue *q);
1154 #else /* CONFIG_BLK_DEV_THROTTLING */
1155 static inline int blk_throtl_bio(struct request_queue *q, struct bio **bio)
1156 {
1157         return 0;
1158 }
1159
1160 static inline int blk_throtl_init(struct request_queue *q) { return 0; }
1161 static inline int blk_throtl_exit(struct request_queue *q) { return 0; }
1162 static inline void throtl_schedule_delayed_work(struct request_queue *q, unsigned long delay) {}
1163 static inline void throtl_shutdown_timer_wq(struct request_queue *q) {}
1164 #endif /* CONFIG_BLK_DEV_THROTTLING */
1165
1166 #define MODULE_ALIAS_BLOCKDEV(major,minor) \
1167         MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor))
1168 #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \
1169         MODULE_ALIAS("block-major-" __stringify(major) "-*")
1170
1171 #if defined(CONFIG_BLK_DEV_INTEGRITY)
1172
1173 #define INTEGRITY_FLAG_READ     2       /* verify data integrity on read */
1174 #define INTEGRITY_FLAG_WRITE    4       /* generate data integrity on write */
1175
1176 struct blk_integrity_exchg {
1177         void                    *prot_buf;
1178         void                    *data_buf;
1179         sector_t                sector;
1180         unsigned int            data_size;
1181         unsigned short          sector_size;
1182         const char              *disk_name;
1183 };
1184
1185 typedef void (integrity_gen_fn) (struct blk_integrity_exchg *);
1186 typedef int (integrity_vrfy_fn) (struct blk_integrity_exchg *);
1187 typedef void (integrity_set_tag_fn) (void *, void *, unsigned int);
1188 typedef void (integrity_get_tag_fn) (void *, void *, unsigned int);
1189
1190 struct blk_integrity {
1191         integrity_gen_fn        *generate_fn;
1192         integrity_vrfy_fn       *verify_fn;
1193         integrity_set_tag_fn    *set_tag_fn;
1194         integrity_get_tag_fn    *get_tag_fn;
1195
1196         unsigned short          flags;
1197         unsigned short          tuple_size;
1198         unsigned short          sector_size;
1199         unsigned short          tag_size;
1200
1201         const char              *name;
1202
1203         struct kobject          kobj;
1204 };
1205
1206 extern int blk_integrity_register(struct gendisk *, struct blk_integrity *);
1207 extern void blk_integrity_unregister(struct gendisk *);
1208 extern int blk_integrity_compare(struct gendisk *, struct gendisk *);
1209 extern int blk_rq_map_integrity_sg(struct request_queue *, struct bio *,
1210                                    struct scatterlist *);
1211 extern int blk_rq_count_integrity_sg(struct request_queue *, struct bio *);
1212 extern int blk_integrity_merge_rq(struct request_queue *, struct request *,
1213                                   struct request *);
1214 extern int blk_integrity_merge_bio(struct request_queue *, struct request *,
1215                                    struct bio *);
1216
1217 static inline
1218 struct blk_integrity *bdev_get_integrity(struct block_device *bdev)
1219 {
1220         return bdev->bd_disk->integrity;
1221 }
1222
1223 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk)
1224 {
1225         return disk->integrity;
1226 }
1227
1228 static inline int blk_integrity_rq(struct request *rq)
1229 {
1230         if (rq->bio == NULL)
1231                 return 0;
1232
1233         return bio_integrity(rq->bio);
1234 }
1235
1236 static inline void blk_queue_max_integrity_segments(struct request_queue *q,
1237                                                     unsigned int segs)
1238 {
1239         q->limits.max_integrity_segments = segs;
1240 }
1241
1242 static inline unsigned short
1243 queue_max_integrity_segments(struct request_queue *q)
1244 {
1245         return q->limits.max_integrity_segments;
1246 }
1247
1248 #else /* CONFIG_BLK_DEV_INTEGRITY */
1249
1250 #define blk_integrity_rq(rq)                    (0)
1251 #define blk_rq_count_integrity_sg(a, b)         (0)
1252 #define blk_rq_map_integrity_sg(a, b, c)        (0)
1253 #define bdev_get_integrity(a)                   (0)
1254 #define blk_get_integrity(a)                    (0)
1255 #define blk_integrity_compare(a, b)             (0)
1256 #define blk_integrity_register(a, b)            (0)
1257 #define blk_integrity_unregister(a)             do { } while (0);
1258 #define blk_queue_max_integrity_segments(a, b)  do { } while (0);
1259 #define queue_max_integrity_segments(a)         (0)
1260 #define blk_integrity_merge_rq(a, b, c)         (0)
1261 #define blk_integrity_merge_bio(a, b, c)        (0)
1262
1263 #endif /* CONFIG_BLK_DEV_INTEGRITY */
1264
1265 struct block_device_operations {
1266         int (*open) (struct block_device *, fmode_t);
1267         int (*release) (struct gendisk *, fmode_t);
1268         int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1269         int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1270         int (*direct_access) (struct block_device *, sector_t,
1271                                                 void **, unsigned long *);
1272         unsigned int (*check_events) (struct gendisk *disk,
1273                                       unsigned int clearing);
1274         /* ->media_changed() is DEPRECATED, use ->check_events() instead */
1275         int (*media_changed) (struct gendisk *);
1276         void (*unlock_native_capacity) (struct gendisk *);
1277         int (*revalidate_disk) (struct gendisk *);
1278         int (*getgeo)(struct block_device *, struct hd_geometry *);
1279         /* this callback is with swap_lock and sometimes page table lock held */
1280         void (*swap_slot_free_notify) (struct block_device *, unsigned long);
1281         struct module *owner;
1282 };
1283
1284 extern int __blkdev_driver_ioctl(struct block_device *, fmode_t, unsigned int,
1285                                  unsigned long);
1286 #else /* CONFIG_BLOCK */
1287 /*
1288  * stubs for when the block layer is configured out
1289  */
1290 #define buffer_heads_over_limit 0
1291
1292 static inline long nr_blockdev_pages(void)
1293 {
1294         return 0;
1295 }
1296
1297 #endif /* CONFIG_BLOCK */
1298
1299 #endif