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