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           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_QUEUED       1       /* uses generic tag queueing */
 385 #define QUEUE_FLAG_STOPPED      2       /* queue is stopped */
 386 #define QUEUE_FLAG_SYNCFULL     3       /* read queue has been filled */
 387 #define QUEUE_FLAG_ASYNCFULL    4       /* write queue has been filled */
 388 #define QUEUE_FLAG_DEAD         5       /* queue being torn down */
 389 #define QUEUE_FLAG_REENTER      6       /* Re-entrancy avoidance */
 390 #define QUEUE_FLAG_PLUGGED      7       /* queue is plugged */
 391 #define QUEUE_FLAG_ELVSWITCH    8       /* don't use elevator, just do FIFO */
 392 #define QUEUE_FLAG_BIDI         9       /* queue supports bidi requests */
 393 #define QUEUE_FLAG_NOMERGES    10       /* disable merge attempts */
 394 #define QUEUE_FLAG_SAME_COMP   11       /* force complete on same CPU */
 395 #define QUEUE_FLAG_FAIL_IO     12       /* fake timeout */
 396 #define QUEUE_FLAG_STACKABLE   13       /* supports request stacking */
 397 #define QUEUE_FLAG_NONROT      14       /* non-rotational device (SSD) */
 398 #define QUEUE_FLAG_VIRT        QUEUE_FLAG_NONROT /* paravirt device */
 399 #define QUEUE_FLAG_IO_STAT     15       /* do IO stats */
 400 #define QUEUE_FLAG_DISCARD     16       /* supports DISCARD */
 401 #define QUEUE_FLAG_NOXMERGES   17       /* No extended merges */
 402 #define QUEUE_FLAG_ADD_RANDOM  18       /* Contributes to random pool */
 403 #define QUEUE_FLAG_SECDISCARD  19       /* supports SECDISCARD */
 404
 405 #define QUEUE_FLAG_DEFAULT      ((1 << QUEUE_FLAG_IO_STAT) |            \
 406                                  (1 << QUEUE_FLAG_STACKABLE)    |       \
 407                                  (1 << QUEUE_FLAG_SAME_COMP)    |       \
 408                                  (1 << QUEUE_FLAG_ADD_RANDOM))
 409
 410 static inline int queue_is_locked(struct request_queue *q)
 411 {
 412 #ifdef CONFIG_SMP
 413         spinlock_t *lock = q->queue_lock;
 414         return lock && spin_is_locked(lock);
 415 #else
 416         return 1;
 417 #endif
 418 }
 419
 420 static inline void queue_flag_set_unlocked(unsigned int flag,
 421                                            struct request_queue *q)
 422 {
 423         __set_bit(flag, &q->queue_flags);
 424 }
 425
 426 static inline int queue_flag_test_and_clear(unsigned int flag,
 427                                             struct request_queue *q)
 428 {
 429         WARN_ON_ONCE(!queue_is_locked(q));
 430
 431         if (test_bit(flag, &q->queue_flags)) {
 432                 __clear_bit(flag, &q->queue_flags);
 433                 return 1;
 434         }
 435
 436         return 0;
 437 }
 438
 439 static inline int queue_flag_test_and_set(unsigned int flag,
 440                                           struct request_queue *q)
 441 {
 442         WARN_ON_ONCE(!queue_is_locked(q));
 443
 444         if (!test_bit(flag, &q->queue_flags)) {
 445                 __set_bit(flag, &q->queue_flags);
 446                 return 0;
 447         }
 448
 449         return 1;
 450 }
 451
 452 static inline void queue_flag_set(unsigned int flag, struct request_queue *q)
 453 {
 454         WARN_ON_ONCE(!queue_is_locked(q));
 455         __set_bit(flag, &q->queue_flags);
 456 }
 457
 458 static inline void queue_flag_clear_unlocked(unsigned int flag,
 459                                              struct request_queue *q)
 460 {
 461         __clear_bit(flag, &q->queue_flags);
 462 }
 463
 464 static inline int queue_in_flight(struct request_queue *q)
 465 {
 466         return q->in_flight[0] + q->in_flight[1];
 467 }
 468
 469 static inline void queue_flag_clear(unsigned int flag, struct request_queue *q)
 470 {
 471         WARN_ON_ONCE(!queue_is_locked(q));
 472         __clear_bit(flag, &q->queue_flags);
 473 }
 474
 475 #define blk_queue_plugged(q)    test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags)
 476 #define blk_queue_tagged(q)     test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags)
 477 #define blk_queue_stopped(q)    test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
 478 #define blk_queue_nomerges(q)   test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags)
 479 #define blk_queue_noxmerges(q)  \
 480         test_bit(QUEUE_FLAG_NOXMERGES, &(q)->queue_flags)
 481 #define blk_queue_nonrot(q)     test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags)
 482 #define blk_queue_io_stat(q)    test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags)
 483 #define blk_queue_add_random(q) test_bit(QUEUE_FLAG_ADD_RANDOM, &(q)->queue_flags)
 484 #define blk_queue_stackable(q)  \
 485         test_bit(QUEUE_FLAG_STACKABLE, &(q)->queue_flags)
 486 #define blk_queue_discard(q)    test_bit(QUEUE_FLAG_DISCARD, &(q)->queue_flags)
 487 #define blk_queue_secdiscard(q) (blk_queue_discard(q) && \
 488         test_bit(QUEUE_FLAG_SECDISCARD, &(q)->queue_flags))
 489
 490 #define blk_noretry_request(rq) \
 491         ((rq)->cmd_flags & (REQ_FAILFAST_DEV|REQ_FAILFAST_TRANSPORT| \
 492                              REQ_FAILFAST_DRIVER))
 493
 494 #define blk_account_rq(rq) \
 495         (((rq)->cmd_flags & REQ_STARTED) && \
 496          ((rq)->cmd_type == REQ_TYPE_FS || \
 497           ((rq)->cmd_flags & REQ_DISCARD)))
 498
 499 #define blk_pm_request(rq)      \
 500         ((rq)->cmd_type == REQ_TYPE_PM_SUSPEND || \
 501          (rq)->cmd_type == REQ_TYPE_PM_RESUME)
 502
 503 #define blk_rq_cpu_valid(rq)    ((rq)->cpu != -1)
 504 #define blk_bidi_rq(rq)         ((rq)->next_rq != NULL)
 505 /* rq->queuelist of dequeued request must be list_empty() */
 506 #define blk_queued_rq(rq)       (!list_empty(&(rq)->queuelist))
 507
 508 #define list_entry_rq(ptr)      list_entry((ptr), struct request, queuelist)
 509
 510 #define rq_data_dir(rq)         ((rq)->cmd_flags & 1)
 511
 512 static inline unsigned int blk_queue_cluster(struct request_queue *q)
 513 {
 514         return q->limits.cluster;
 515 }
 516
 517 /*
 518  * We regard a request as sync, if either a read or a sync write
 519  */
 520 static inline bool rw_is_sync(unsigned int rw_flags)
 521 {
 522         return !(rw_flags & REQ_WRITE) || (rw_flags & REQ_SYNC);
 523 }
 524
 525 static inline bool rq_is_sync(struct request *rq)
 526 {
 527         return rw_is_sync(rq->cmd_flags);
 528 }
 529
 530 static inline int blk_queue_full(struct request_queue *q, int sync)
 531 {
 532         if (sync)
 533                 return test_bit(QUEUE_FLAG_SYNCFULL, &q->queue_flags);
 534         return test_bit(QUEUE_FLAG_ASYNCFULL, &q->queue_flags);
 535 }
 536
 537 static inline void blk_set_queue_full(struct request_queue *q, int sync)
 538 {
 539         if (sync)
 540                 queue_flag_set(QUEUE_FLAG_SYNCFULL, q);
 541         else
 542                 queue_flag_set(QUEUE_FLAG_ASYNCFULL, q);
 543 }
 544
 545 static inline void blk_clear_queue_full(struct request_queue *q, int sync)
 546 {
 547         if (sync)
 548                 queue_flag_clear(QUEUE_FLAG_SYNCFULL, q);
 549         else
 550                 queue_flag_clear(QUEUE_FLAG_ASYNCFULL, q);
 551 }
 552
 553
 554 /*
 555  * mergeable request must not have _NOMERGE or _BARRIER bit set, nor may
 556  * it already be started by driver.
 557  */
 558 #define RQ_NOMERGE_FLAGS        \
 559         (REQ_NOMERGE | REQ_STARTED | REQ_SOFTBARRIER | REQ_FLUSH | REQ_FUA)
 560 #define rq_mergeable(rq)        \
 561         (!((rq)->cmd_flags & RQ_NOMERGE_FLAGS) && \
 562          (((rq)->cmd_flags & REQ_DISCARD) || \
 563           (rq)->cmd_type == REQ_TYPE_FS))
 564
 565 /*
 566  * q->prep_rq_fn return values
 567  */
 568 #define BLKPREP_OK              0       /* serve it */
 569 #define BLKPREP_KILL            1       /* fatal error, kill */
 570 #define BLKPREP_DEFER           2       /* leave on queue */
 571
 572 extern unsigned long blk_max_low_pfn, blk_max_pfn;
 573
 574 /*
 575  * standard bounce addresses:
 576  *
 577  * BLK_BOUNCE_HIGH      : bounce all highmem pages
 578  * BLK_BOUNCE_ANY       : don't bounce anything
 579  * BLK_BOUNCE_ISA       : bounce pages above ISA DMA boundary
 580  */
 581
 582 #if BITS_PER_LONG == 32
 583 #define BLK_BOUNCE_HIGH         ((u64)blk_max_low_pfn << PAGE_SHIFT)
 584 #else
 585 #define BLK_BOUNCE_HIGH         -1ULL
 586 #endif
 587 #define BLK_BOUNCE_ANY          (-1ULL)
 588 #define BLK_BOUNCE_ISA          (DMA_BIT_MASK(24))
 589
 590 /*
 591  * default timeout for SG_IO if none specified
 592  */
 593 #define BLK_DEFAULT_SG_TIMEOUT  (60 * HZ)
 594 #define BLK_MIN_SG_TIMEOUT      (7 * HZ)
 595
 596 #ifdef CONFIG_BOUNCE
 597 extern int init_emergency_isa_pool(void);
 598 extern void blk_queue_bounce(struct request_queue *q, struct bio **bio);
 599 #else
 600 static inline int init_emergency_isa_pool(void)
 601 {
 602         return 0;
 603 }
 604 static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio)
 605 {
 606 }
 607 #endif /* CONFIG_MMU */
 608
 609 struct rq_map_data {
 610         struct page **pages;
 611         int page_order;
 612         int nr_entries;
 613         unsigned long offset;
 614         int null_mapped;
 615         int from_user;
 616 };
 617
 618 struct req_iterator {
 619         int i;
 620         struct bio *bio;
 621 };
 622
 623 /* This should not be used directly - use rq_for_each_segment */
 624 #define for_each_bio(_bio)              \
 625         for (; _bio; _bio = _bio->bi_next)
 626 #define __rq_for_each_bio(_bio, rq)     \
 627         if ((rq->bio))                  \
 628                 for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next)
 629
 630 #define rq_for_each_segment(bvl, _rq, _iter)                    \
 631         __rq_for_each_bio(_iter.bio, _rq)                       \
 632                 bio_for_each_segment(bvl, _iter.bio, _iter.i)
 633
 634 #define rq_iter_last(rq, _iter)                                 \
 635                 (_iter.bio->bi_next == NULL && _iter.i == _iter.bio->bi_vcnt-1)
 636
 637 #ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
 638 # error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform"
 639 #endif
 640 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
 641 extern void rq_flush_dcache_pages(struct request *rq);
 642 #else
 643 static inline void rq_flush_dcache_pages(struct request *rq)
 644 {
 645 }
 646 #endif
 647
 648 extern int blk_register_queue(struct gendisk *disk);
 649 extern void blk_unregister_queue(struct gendisk *disk);
 650 extern void register_disk(struct gendisk *dev);
 651 extern void generic_make_request(struct bio *bio);
 652 extern void blk_rq_init(struct request_queue *q, struct request *rq);
 653 extern void blk_put_request(struct request *);
 654 extern void __blk_put_request(struct request_queue *, struct request *);
 655 extern struct request *blk_get_request(struct request_queue *, int, gfp_t);
 656 extern struct request *blk_make_request(struct request_queue *, struct bio *,
 657                                         gfp_t);
 658 extern void blk_insert_request(struct request_queue *, struct request *, int, void *);
 659 extern void blk_requeue_request(struct request_queue *, struct request *);
 660 extern void blk_add_request_payload(struct request *rq, struct page *page,
 661                 unsigned int len);
 662 extern int blk_rq_check_limits(struct request_queue *q, struct request *rq);
 663 extern int blk_lld_busy(struct request_queue *q);
 664 extern int blk_rq_prep_clone(struct request *rq, struct request *rq_src,
 665                              struct bio_set *bs, gfp_t gfp_mask,
 666                              int (*bio_ctr)(struct bio *, struct bio *, void *),
 667                              void *data);
 668 extern void blk_rq_unprep_clone(struct request *rq);
 669 extern int blk_insert_cloned_request(struct request_queue *q,
 670                                      struct request *rq);
 671 extern void blk_plug_device(struct request_queue *);
 672 extern void blk_plug_device_unlocked(struct request_queue *);
 673 extern int blk_remove_plug(struct request_queue *);
 674 extern void blk_recount_segments(struct request_queue *, struct bio *);
 675 extern int scsi_cmd_ioctl(struct request_queue *, struct gendisk *, fmode_t,
 676                           unsigned int, void __user *);
 677 extern int sg_scsi_ioctl(struct request_queue *, struct gendisk *, fmode_t,
 678                          struct scsi_ioctl_command __user *);
 679
 680 /*
 681  * A queue has just exitted congestion.  Note this in the global counter of
 682  * congested queues, and wake up anyone who was waiting for requests to be
 683  * put back.
 684  */
 685 static inline void blk_clear_queue_congested(struct request_queue *q, int sync)
 686 {
 687         clear_bdi_congested(&q->backing_dev_info, sync);
 688 }
 689
 690 /*
 691  * A queue has just entered congestion.  Flag that in the queue's VM-visible
 692  * state flags and increment the global gounter of congested queues.
 693  */
 694 static inline void blk_set_queue_congested(struct request_queue *q, int sync)
 695 {
 696         set_bdi_congested(&q->backing_dev_info, sync);
 697 }
 698
 699 extern void blk_start_queue(struct request_queue *q);
 700 extern void blk_stop_queue(struct request_queue *q);
 701 extern void blk_sync_queue(struct request_queue *q);
 702 extern void __blk_stop_queue(struct request_queue *q);
 703 extern void __blk_run_queue(struct request_queue *);
 704 extern void blk_run_queue(struct request_queue *);
 705 extern int blk_rq_map_user(struct request_queue *, struct request *,
 706                            struct rq_map_data *, void __user *, unsigned long,
 707                            gfp_t);
 708 extern int blk_rq_unmap_user(struct bio *);
 709 extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, unsigned int, gfp_t);
 710 extern int blk_rq_map_user_iov(struct request_queue *, struct request *,
 711                                struct rq_map_data *, struct sg_iovec *, int,
 712                                unsigned int, gfp_t);
 713 extern int blk_execute_rq(struct request_queue *, struct gendisk *,
 714                           struct request *, int);
 715 extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *,
 716                                   struct request *, int, rq_end_io_fn *);
 717 extern void blk_unplug(struct request_queue *q);
 718
 719 static inline struct request_queue *bdev_get_queue(struct block_device *bdev)
 720 {
 721         return bdev->bd_disk->queue;
 722 }
 723
 724 /*
 725  * blk_rq_pos()                 : the current sector
 726  * blk_rq_bytes()               : bytes left in the entire request
 727  * blk_rq_cur_bytes()           : bytes left in the current segment
 728  * blk_rq_err_bytes()           : bytes left till the next error boundary
 729  * blk_rq_sectors()             : sectors left in the entire request
 730  * blk_rq_cur_sectors()         : sectors left in the current segment
 731  */
 732 static inline sector_t blk_rq_pos(const struct request *rq)
 733 {
 734         return rq->__sector;
 735 }
 736
 737 static inline unsigned int blk_rq_bytes(const struct request *rq)
 738 {
 739         return rq->__data_len;
 740 }
 741
 742 static inline int blk_rq_cur_bytes(const struct request *rq)
 743 {
 744         return rq->bio ? bio_cur_bytes(rq->bio) : 0;
 745 }
 746
 747 extern unsigned int blk_rq_err_bytes(const struct request *rq);
 748
 749 static inline unsigned int blk_rq_sectors(const struct request *rq)
 750 {
 751         return blk_rq_bytes(rq) >> 9;
 752 }
 753
 754 static inline unsigned int blk_rq_cur_sectors(const struct request *rq)
 755 {
 756         return blk_rq_cur_bytes(rq) >> 9;
 757 }
 758
 759 /*
 760  * Request issue related functions.
 761  */
 762 extern struct request *blk_peek_request(struct request_queue *q);
 763 extern void blk_start_request(struct request *rq);
 764 extern struct request *blk_fetch_request(struct request_queue *q);
 765
 766 /*
 767  * Request completion related functions.
 768  *
 769  * blk_update_request() completes given number of bytes and updates
 770  * the request without completing it.
 771  *
 772  * blk_end_request() and friends.  __blk_end_request() must be called
 773  * with the request queue spinlock acquired.
 774  *
 775  * Several drivers define their own end_request and call
 776  * blk_end_request() for parts of the original function.
 777  * This prevents code duplication in drivers.
 778  */
 779 extern bool blk_update_request(struct request *rq, int error,
 780                                unsigned int nr_bytes);
 781 extern bool blk_end_request(struct request *rq, int error,
 782                             unsigned int nr_bytes);
 783 extern void blk_end_request_all(struct request *rq, int error);
 784 extern bool blk_end_request_cur(struct request *rq, int error);
 785 extern bool blk_end_request_err(struct request *rq, int error);
 786 extern bool __blk_end_request(struct request *rq, int error,
 787                               unsigned int nr_bytes);
 788 extern void __blk_end_request_all(struct request *rq, int error);
 789 extern bool __blk_end_request_cur(struct request *rq, int error);
 790 extern bool __blk_end_request_err(struct request *rq, int error);
 791
 792 extern void blk_complete_request(struct request *);
 793 extern void __blk_complete_request(struct request *);
 794 extern void blk_abort_request(struct request *);
 795 extern void blk_abort_queue(struct request_queue *);
 796 extern void blk_unprep_request(struct request *);
 797
 798 /*
 799  * Access functions for manipulating queue properties
 800  */
 801 extern struct request_queue *blk_init_queue_node(request_fn_proc *rfn,
 802                                         spinlock_t *lock, int node_id);
 803 extern struct request_queue *blk_init_allocated_queue_node(struct request_queue *,
 804                                                            request_fn_proc *,
 805                                                            spinlock_t *, int node_id);
 806 extern struct request_queue *blk_init_queue(request_fn_proc *, spinlock_t *);
 807 extern struct request_queue *blk_init_allocated_queue(struct request_queue *,
 808                                                       request_fn_proc *, spinlock_t *);
 809 extern void blk_cleanup_queue(struct request_queue *);
 810 extern void blk_queue_make_request(struct request_queue *, make_request_fn *);
 811 extern void blk_queue_bounce_limit(struct request_queue *, u64);
 812 extern void blk_limits_max_hw_sectors(struct queue_limits *, unsigned int);
 813 extern void blk_queue_max_hw_sectors(struct request_queue *, unsigned int);
 814 extern void blk_queue_max_segments(struct request_queue *, unsigned short);
 815 extern void blk_queue_max_segment_size(struct request_queue *, unsigned int);
 816 extern void blk_queue_max_discard_sectors(struct request_queue *q,
 817                 unsigned int max_discard_sectors);
 818 extern void blk_queue_logical_block_size(struct request_queue *, unsigned short);
 819 extern void blk_queue_physical_block_size(struct request_queue *, unsigned int);
 820 extern void blk_queue_alignment_offset(struct request_queue *q,
 821                                        unsigned int alignment);
 822 extern void blk_limits_io_min(struct queue_limits *limits, unsigned int min);
 823 extern void blk_queue_io_min(struct request_queue *q, unsigned int min);
 824 extern void blk_limits_io_opt(struct queue_limits *limits, unsigned int opt);
 825 extern void blk_queue_io_opt(struct request_queue *q, unsigned int opt);
 826 extern void blk_set_default_limits(struct queue_limits *lim);
 827 extern int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
 828                             sector_t offset);
 829 extern int bdev_stack_limits(struct queue_limits *t, struct block_device *bdev,
 830                             sector_t offset);
 831 extern void disk_stack_limits(struct gendisk *disk, struct block_device *bdev,
 832                               sector_t offset);
 833 extern void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b);
 834 extern void blk_queue_dma_pad(struct request_queue *, unsigned int);
 835 extern void blk_queue_update_dma_pad(struct request_queue *, unsigned int);
 836 extern int blk_queue_dma_drain(struct request_queue *q,
 837                                dma_drain_needed_fn *dma_drain_needed,
 838                                void *buf, unsigned int size);
 839 extern void blk_queue_lld_busy(struct request_queue *q, lld_busy_fn *fn);
 840 extern void blk_queue_segment_boundary(struct request_queue *, unsigned long);
 841 extern void blk_queue_prep_rq(struct request_queue *, prep_rq_fn *pfn);
 842 extern void blk_queue_unprep_rq(struct request_queue *, unprep_rq_fn *ufn);
 843 extern void blk_queue_merge_bvec(struct request_queue *, merge_bvec_fn *);
 844 extern void blk_queue_dma_alignment(struct request_queue *, int);
 845 extern void blk_queue_update_dma_alignment(struct request_queue *, int);
 846 extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *);
 847 extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *);
 848 extern void blk_queue_rq_timeout(struct request_queue *, unsigned int);
 849 extern void blk_queue_flush(struct request_queue *q, unsigned int flush);
 850 extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev);
 851
 852 extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *);
 853 extern void blk_dump_rq_flags(struct request *, char *);
 854 extern void generic_unplug_device(struct request_queue *);
 855 extern long nr_blockdev_pages(void);
 856
 857 int blk_get_queue(struct request_queue *);
 858 struct request_queue *blk_alloc_queue(gfp_t);
 859 struct request_queue *blk_alloc_queue_node(gfp_t, int);
 860 extern void blk_put_queue(struct request_queue *);
 861
 862 /*
 863  * tag stuff
 864  */
 865 #define blk_rq_tagged(rq)               ((rq)->cmd_flags & REQ_QUEUED)
 866 extern int blk_queue_start_tag(struct request_queue *, struct request *);
 867 extern struct request *blk_queue_find_tag(struct request_queue *, int);
 868 extern void blk_queue_end_tag(struct request_queue *, struct request *);
 869 extern int blk_queue_init_tags(struct request_queue *, int, struct blk_queue_tag *);
 870 extern void blk_queue_free_tags(struct request_queue *);
 871 extern int blk_queue_resize_tags(struct request_queue *, int);
 872 extern void blk_queue_invalidate_tags(struct request_queue *);
 873 extern struct blk_queue_tag *blk_init_tags(int);
 874 extern void blk_free_tags(struct blk_queue_tag *);
 875
 876 static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt,
 877                                                 int tag)
 878 {
 879         if (unlikely(bqt == NULL || tag >= bqt->real_max_depth))
 880                 return NULL;
 881         return bqt->tag_index[tag];
 882 }
 883
 884 #define BLKDEV_DISCARD_SECURE  0x01    /* secure discard */
 885
 886 extern int blkdev_issue_flush(struct block_device *, gfp_t, sector_t *);
 887 extern int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
 888                 sector_t nr_sects, gfp_t gfp_mask, unsigned long flags);
 889 extern int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
 890                         sector_t nr_sects, gfp_t gfp_mask);
 891 static inline int sb_issue_discard(struct super_block *sb, sector_t block,
 892                 sector_t nr_blocks, gfp_t gfp_mask, unsigned long flags)
 893 {
 894         return blkdev_issue_discard(sb->s_bdev, block << (sb->s_blocksize_bits - 9),
 895                                     nr_blocks << (sb->s_blocksize_bits - 9),
 896                                     gfp_mask, flags);
 897 }
 898 static inline int sb_issue_zeroout(struct super_block *sb, sector_t block,
 899                 sector_t nr_blocks, gfp_t gfp_mask)
 900 {
 901         return blkdev_issue_zeroout(sb->s_bdev,
 902                                     block << (sb->s_blocksize_bits - 9),
 903                                     nr_blocks << (sb->s_blocksize_bits - 9),
 904                                     gfp_mask);
 905 }
 906
 907 extern int blk_verify_command(unsigned char *cmd, fmode_t has_write_perm);
 908
 909 enum blk_default_limits {
 910         BLK_MAX_SEGMENTS        = 128,
 911         BLK_SAFE_MAX_SECTORS    = 255,
 912         BLK_DEF_MAX_SECTORS     = 1024,
 913         BLK_MAX_SEGMENT_SIZE    = 65536,
 914         BLK_SEG_BOUNDARY_MASK   = 0xFFFFFFFFUL,
 915 };
 916
 917 #define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist)
 918
 919 static inline unsigned long queue_bounce_pfn(struct request_queue *q)
 920 {
 921         return q->limits.bounce_pfn;
 922 }
 923
 924 static inline unsigned long queue_segment_boundary(struct request_queue *q)
 925 {
 926         return q->limits.seg_boundary_mask;
 927 }
 928
 929 static inline unsigned int queue_max_sectors(struct request_queue *q)
 930 {
 931         return q->limits.max_sectors;
 932 }
 933
 934 static inline unsigned int queue_max_hw_sectors(struct request_queue *q)
 935 {
 936         return q->limits.max_hw_sectors;
 937 }
 938
 939 static inline unsigned short queue_max_segments(struct request_queue *q)
 940 {
 941         return q->limits.max_segments;
 942 }
 943
 944 static inline unsigned int queue_max_segment_size(struct request_queue *q)
 945 {
 946         return q->limits.max_segment_size;
 947 }
 948
 949 static inline unsigned short queue_logical_block_size(struct request_queue *q)
 950 {
 951         int retval = 512;
 952
 953         if (q && q->limits.logical_block_size)
 954                 retval = q->limits.logical_block_size;
 955
 956         return retval;
 957 }
 958
 959 static inline unsigned short bdev_logical_block_size(struct block_device *bdev)
 960 {
 961         return queue_logical_block_size(bdev_get_queue(bdev));
 962 }
 963
 964 static inline unsigned int queue_physical_block_size(struct request_queue *q)
 965 {
 966         return q->limits.physical_block_size;
 967 }
 968
 969 static inline unsigned int bdev_physical_block_size(struct block_device *bdev)
 970 {
 971         return queue_physical_block_size(bdev_get_queue(bdev));
 972 }
 973
 974 static inline unsigned int queue_io_min(struct request_queue *q)
 975 {
 976         return q->limits.io_min;
 977 }
 978
 979 static inline int bdev_io_min(struct block_device *bdev)
 980 {
 981         return queue_io_min(bdev_get_queue(bdev));
 982 }
 983
 984 static inline unsigned int queue_io_opt(struct request_queue *q)
 985 {
 986         return q->limits.io_opt;
 987 }
 988
 989 static inline int bdev_io_opt(struct block_device *bdev)
 990 {
 991         return queue_io_opt(bdev_get_queue(bdev));
 992 }
 993
 994 static inline int queue_alignment_offset(struct request_queue *q)
 995 {
 996         if (q->limits.misaligned)
 997                 return -1;
 998
 999         return q->limits.alignment_offset;
1000 }
1001
1002 static inline int queue_limit_alignment_offset(struct queue_limits *lim, sector_t sector)
1003 {
1004         unsigned int granularity = max(lim->physical_block_size, lim->io_min);
1005         unsigned int alignment = (sector << 9) & (granularity - 1);
1006
1007         return (granularity + lim->alignment_offset - alignment)
1008                 & (granularity - 1);
1009 }
1010
1011 static inline int bdev_alignment_offset(struct block_device *bdev)
1012 {
1013         struct request_queue *q = bdev_get_queue(bdev);
1014
1015         if (q->limits.misaligned)
1016                 return -1;
1017
1018         if (bdev != bdev->bd_contains)
1019                 return bdev->bd_part->alignment_offset;
1020
1021         return q->limits.alignment_offset;
1022 }
1023
1024 static inline int queue_discard_alignment(struct request_queue *q)
1025 {
1026         if (q->limits.discard_misaligned)
1027                 return -1;
1028
1029         return q->limits.discard_alignment;
1030 }
1031
1032 static inline int queue_limit_discard_alignment(struct queue_limits *lim, sector_t sector)
1033 {
1034         unsigned int alignment = (sector << 9) & (lim->discard_granularity - 1);
1035
1036         return (lim->discard_granularity + lim->discard_alignment - alignment)
1037                 & (lim->discard_granularity - 1);
1038 }
1039
1040 static inline unsigned int queue_discard_zeroes_data(struct request_queue *q)
1041 {
1042         if (q->limits.discard_zeroes_data == 1)
1043                 return 1;
1044
1045         return 0;
1046 }
1047
1048 static inline unsigned int bdev_discard_zeroes_data(struct block_device *bdev)
1049 {
1050         return queue_discard_zeroes_data(bdev_get_queue(bdev));
1051 }
1052
1053 static inline int queue_dma_alignment(struct request_queue *q)
1054 {
1055         return q ? q->dma_alignment : 511;
1056 }
1057
1058 static inline int blk_rq_aligned(struct request_queue *q, unsigned long addr,
1059                                  unsigned int len)
1060 {
1061         unsigned int alignment = queue_dma_alignment(q) | q->dma_pad_mask;
1062         return !(addr & alignment) && !(len & alignment);
1063 }
1064
1065 /* assumes size > 256 */
1066 static inline unsigned int blksize_bits(unsigned int size)
1067 {
1068         unsigned int bits = 8;
1069         do {
1070                 bits++;
1071                 size >>= 1;
1072         } while (size > 256);
1073         return bits;
1074 }
1075
1076 static inline unsigned int block_size(struct block_device *bdev)
1077 {
1078         return bdev->bd_block_size;
1079 }
1080
1081 typedef struct {struct page *v;} Sector;
1082
1083 unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *);
1084
1085 static inline void put_dev_sector(Sector p)
1086 {
1087         page_cache_release(p.v);
1088 }
1089
1090 struct work_struct;
1091 int kblockd_schedule_work(struct request_queue *q, struct work_struct *work);
1092
1093 #ifdef CONFIG_BLK_CGROUP
1094 /*
1095  * This should not be using sched_clock(). A real patch is in progress
1096  * to fix this up, until that is in place we need to disable preemption
1097  * around sched_clock() in this function and set_io_start_time_ns().
1098  */
1099 static inline void set_start_time_ns(struct request *req)
1100 {
1101         preempt_disable();
1102         req->start_time_ns = sched_clock();
1103         preempt_enable();
1104 }
1105
1106 static inline void set_io_start_time_ns(struct request *req)
1107 {
1108         preempt_disable();
1109         req->io_start_time_ns = sched_clock();
1110         preempt_enable();
1111 }
1112
1113 static inline uint64_t rq_start_time_ns(struct request *req)
1114 {
1115         return req->start_time_ns;
1116 }
1117
1118 static inline uint64_t rq_io_start_time_ns(struct request *req)
1119 {
1120         return req->io_start_time_ns;
1121 }
1122 #else
1123 static inline void set_start_time_ns(struct request *req) {}
1124 static inline void set_io_start_time_ns(struct request *req) {}
1125 static inline uint64_t rq_start_time_ns(struct request *req)
1126 {
1127         return 0;
1128 }
1129 static inline uint64_t rq_io_start_time_ns(struct request *req)
1130 {
1131         return 0;
1132 }
1133 #endif
1134
1135 #ifdef CONFIG_BLK_DEV_THROTTLING
1136 extern int blk_throtl_init(struct request_queue *q);
1137 extern void blk_throtl_exit(struct request_queue *q);
1138 extern int blk_throtl_bio(struct request_queue *q, struct bio **bio);
1139 extern void throtl_shutdown_timer_wq(struct request_queue *q);
1140 #else /* CONFIG_BLK_DEV_THROTTLING */
1141 static inline int blk_throtl_bio(struct request_queue *q, struct bio **bio)
1142 {
1143         return 0;
1144 }
1145
1146 static inline int blk_throtl_init(struct request_queue *q) { return 0; }
1147 static inline int blk_throtl_exit(struct request_queue *q) { return 0; }
1148 static inline void throtl_shutdown_timer_wq(struct request_queue *q) {}
1149 #endif /* CONFIG_BLK_DEV_THROTTLING */
1150
1151 #define MODULE_ALIAS_BLOCKDEV(major,minor) \
1152         MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor))
1153 #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \
1154         MODULE_ALIAS("block-major-" __stringify(major) "-*")
1155
1156 #if defined(CONFIG_BLK_DEV_INTEGRITY)
1157
1158 #define INTEGRITY_FLAG_READ     2       /* verify data integrity on read */
1159 #define INTEGRITY_FLAG_WRITE    4       /* generate data integrity on write */
1160
1161 struct blk_integrity_exchg {
1162         void                    *prot_buf;
1163         void                    *data_buf;
1164         sector_t                sector;
1165         unsigned int            data_size;
1166         unsigned short          sector_size;
1167         const char              *disk_name;
1168 };
1169
1170 typedef void (integrity_gen_fn) (struct blk_integrity_exchg *);
1171 typedef int (integrity_vrfy_fn) (struct blk_integrity_exchg *);
1172 typedef void (integrity_set_tag_fn) (void *, void *, unsigned int);
1173 typedef void (integrity_get_tag_fn) (void *, void *, unsigned int);
1174
1175 struct blk_integrity {
1176         integrity_gen_fn        *generate_fn;
1177         integrity_vrfy_fn       *verify_fn;
1178         integrity_set_tag_fn    *set_tag_fn;
1179         integrity_get_tag_fn    *get_tag_fn;
1180
1181         unsigned short          flags;
1182         unsigned short          tuple_size;
1183         unsigned short          sector_size;
1184         unsigned short          tag_size;
1185
1186         const char              *name;
1187
1188         struct kobject          kobj;
1189 };
1190
1191 extern int blk_integrity_register(struct gendisk *, struct blk_integrity *);
1192 extern void blk_integrity_unregister(struct gendisk *);
1193 extern int blk_integrity_compare(struct gendisk *, struct gendisk *);
1194 extern int blk_rq_map_integrity_sg(struct request_queue *, struct bio *,
1195                                    struct scatterlist *);
1196 extern int blk_rq_count_integrity_sg(struct request_queue *, struct bio *);
1197 extern int blk_integrity_merge_rq(struct request_queue *, struct request *,
1198                                   struct request *);
1199 extern int blk_integrity_merge_bio(struct request_queue *, struct request *,
1200                                    struct bio *);
1201
1202 static inline
1203 struct blk_integrity *bdev_get_integrity(struct block_device *bdev)
1204 {
1205         return bdev->bd_disk->integrity;
1206 }
1207
1208 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk)
1209 {
1210         return disk->integrity;
1211 }
1212
1213 static inline int blk_integrity_rq(struct request *rq)
1214 {
1215         if (rq->bio == NULL)
1216                 return 0;
1217
1218         return bio_integrity(rq->bio);
1219 }
1220
1221 static inline void blk_queue_max_integrity_segments(struct request_queue *q,
1222                                                     unsigned int segs)
1223 {
1224         q->limits.max_integrity_segments = segs;
1225 }
1226
1227 static inline unsigned short
1228 queue_max_integrity_segments(struct request_queue *q)
1229 {
1230         return q->limits.max_integrity_segments;
1231 }
1232
1233 #else /* CONFIG_BLK_DEV_INTEGRITY */
1234
1235 #define blk_integrity_rq(rq)                    (0)
1236 #define blk_rq_count_integrity_sg(a, b)         (0)
1237 #define blk_rq_map_integrity_sg(a, b, c)        (0)
1238 #define bdev_get_integrity(a)                   (0)
1239 #define blk_get_integrity(a)                    (0)
1240 #define blk_integrity_compare(a, b)             (0)
1241 #define blk_integrity_register(a, b)            (0)
1242 #define blk_integrity_unregister(a)             do { } while (0);
1243 #define blk_queue_max_integrity_segments(a, b)  do { } while (0);
1244 #define queue_max_integrity_segments(a)         (0)
1245 #define blk_integrity_merge_rq(a, b, c)         (0)
1246 #define blk_integrity_merge_bio(a, b, c)        (0)
1247
1248 #endif /* CONFIG_BLK_DEV_INTEGRITY */
1249
1250 struct block_device_operations {
1251         int (*open) (struct block_device *, fmode_t);
1252         int (*release) (struct gendisk *, fmode_t);
1253         int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1254         int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1255         int (*direct_access) (struct block_device *, sector_t,
1256                                                 void **, unsigned long *);
1257         int (*media_changed) (struct gendisk *);
1258         void (*unlock_native_capacity) (struct gendisk *);
1259         int (*revalidate_disk) (struct gendisk *);
1260         int (*getgeo)(struct block_device *, struct hd_geometry *);
1261         /* this callback is with swap_lock and sometimes page table lock held */
1262         void (*swap_slot_free_notify) (struct block_device *, unsigned long);
1263         struct module *owner;
1264 };
1265
1266 extern int __blkdev_driver_ioctl(struct block_device *, fmode_t, unsigned int,
1267                                  unsigned long);
1268 #else /* CONFIG_BLOCK */
1269 /*
1270  * stubs for when the block layer is configured out
1271  */
1272 #define buffer_heads_over_limit 0
1273
1274 static inline long nr_blockdev_pages(void)
1275 {
1276         return 0;
1277 }
1278
1279 #endif /* CONFIG_BLOCK */
1280
1281 #endif