include/linux/blkdev.h

   1 #ifndef _LINUX_BLKDEV_H
   2 #define _LINUX_BLKDEV_H
   3
   4 #ifdef CONFIG_BLOCK
   5
   6 #include <linux/sched.h>
   7 #include <linux/major.h>
   8 #include <linux/genhd.h>
   9 #include <linux/list.h>
  10 #include <linux/timer.h>
  11 #include <linux/workqueue.h>
  12 #include <linux/pagemap.h>
  13 #include <linux/backing-dev.h>
  14 #include <linux/wait.h>
  15 #include <linux/mempool.h>
  16 #include <linux/bio.h>
  17 #include <linux/module.h>
  18 #include <linux/stringify.h>
  19 #include <linux/gfp.h>
  20 #include <linux/bsg.h>
  21 #include <linux/smp.h>
  22
  23 #include <asm/scatterlist.h>
  24
  25 struct scsi_ioctl_command;
  26
  27 struct request_queue;
  28 struct elevator_queue;
  29 struct request_pm_state;
  30 struct blk_trace;
  31 struct request;
  32 struct sg_io_hdr;
  33
  34 #define BLKDEV_MIN_RQ   4
  35 #define BLKDEV_MAX_RQ   128     /* Default maximum */
  36
  37 struct request;
  38 typedef void (rq_end_io_fn)(struct request *, int);
  39
  40 struct request_list {
  41         /*
  42          * count[], starved[], and wait[] are indexed by
  43          * BLK_RW_SYNC/BLK_RW_ASYNC
  44          */
  45         int count[2];
  46         int starved[2];
  47         int elvpriv;
  48         mempool_t *rq_pool;
  49         wait_queue_head_t wait[2];
  50 };
  51
  52 /*
  53  * request command types
  54  */
  55 enum rq_cmd_type_bits {
  56         REQ_TYPE_FS             = 1,    /* fs request */
  57         REQ_TYPE_BLOCK_PC,              /* scsi command */
  58         REQ_TYPE_SENSE,                 /* sense request */
  59         REQ_TYPE_PM_SUSPEND,            /* suspend request */
  60         REQ_TYPE_PM_RESUME,             /* resume request */
  61         REQ_TYPE_PM_SHUTDOWN,           /* shutdown request */
  62         REQ_TYPE_SPECIAL,               /* driver defined type */
  63         /*
  64          * for ATA/ATAPI devices. this really doesn't belong here, ide should
  65          * use REQ_TYPE_SPECIAL and use rq->cmd[0] with the range of driver
  66          * private REQ_LB opcodes to differentiate what type of request this is
  67          */
  68         REQ_TYPE_ATA_TASKFILE,
  69         REQ_TYPE_ATA_PC,
  70 };
  71
  72 #define BLK_MAX_CDB     16
  73
  74 /*
  75  * try to put the fields that are referenced together in the same cacheline.
  76  * if you modify this structure, be sure to check block/blk-core.c:rq_init()
  77  * as well!
  78  */
  79 struct request {
  80         struct list_head queuelist;
  81         struct call_single_data csd;
  82
  83         struct request_queue *q;
  84
  85         unsigned int cmd_flags;
  86         enum rq_cmd_type_bits cmd_type;
  87         unsigned long atomic_flags;
  88
  89         int cpu;
  90
  91         /* the following two fields are internal, NEVER access directly */
  92         unsigned int __data_len;        /* total data len */
  93         sector_t __sector;              /* sector cursor */
  94
  95         struct bio *bio;
  96         struct bio *biotail;
  97
  98         struct hlist_node hash; /* merge hash */
  99         /*
 100          * The rb_node is only used inside the io scheduler, requests
 101          * are pruned when moved to the dispatch queue. So let the
 102          * completion_data share space with the rb_node.
 103          */
 104         union {
 105                 struct rb_node rb_node; /* sort/lookup */
 106                 void *completion_data;
 107         };
 108
 109         /*
 110          * Three pointers are available for the IO schedulers, if they need
 111          * more they have to dynamically allocate it.  Flush requests are
 112          * never put on the IO scheduler. So let the flush fields share
 113          * space with the three elevator_private pointers.
 114          */
 115         union {
 116                 void *elevator_private[3];
 117                 struct {
 118                         unsigned int            seq;
 119                         struct list_head        list;
 120                 } flush;
 121         };
 122
 123         struct gendisk *rq_disk;
 124         struct hd_struct *part;
 125         unsigned long start_time;
 126 #ifdef CONFIG_BLK_CGROUP
 127         unsigned long long start_time_ns;
 128         unsigned long long io_start_time_ns;    /* when passed to hardware */
 129 #endif
 130         /* Number of scatter-gather DMA addr+len pairs after
 131          * physical address coalescing is performed.
 132          */
 133         unsigned short nr_phys_segments;
 134 #if defined(CONFIG_BLK_DEV_INTEGRITY)
 135         unsigned short nr_integrity_segments;
 136 #endif
 137
 138         unsigned short ioprio;
 139
 140         int ref_count;
 141
 142         void *special;          /* opaque pointer available for LLD use */
 143         char *buffer;           /* kaddr of the current segment if available */
 144
 145         int tag;
 146         int errors;
 147
 148         /*
 149          * when request is used as a packet command carrier
 150          */
 151         unsigned char __cmd[BLK_MAX_CDB];
 152         unsigned char *cmd;
 153         unsigned short cmd_len;
 154
 155         unsigned int extra_len; /* length of alignment and padding */
 156         unsigned int sense_len;
 157         unsigned int resid_len; /* residual count */
 158         void *sense;
 159
 160         unsigned long deadline;
 161         struct list_head timeout_list;
 162         unsigned int timeout;
 163         int retries;
 164
 165         /*
 166          * completion callback.
 167          */
 168         rq_end_io_fn *end_io;
 169         void *end_io_data;
 170
 171         /* for bidi */
 172         struct request *next_rq;
 173 };
 174
 175 static inline unsigned short req_get_ioprio(struct request *req)
 176 {
 177         return req->ioprio;
 178 }
 179
 180 /*
 181  * State information carried for REQ_TYPE_PM_SUSPEND and REQ_TYPE_PM_RESUME
 182  * requests. Some step values could eventually be made generic.
 183  */
 184 struct request_pm_state
 185 {
 186         /* PM state machine step value, currently driver specific */
 187         int     pm_step;
 188         /* requested PM state value (S1, S2, S3, S4, ...) */
 189         u32     pm_state;
 190         void*   data;           /* for driver use */
 191 };
 192
 193 #include <linux/elevator.h>
 194
 195 typedef void (request_fn_proc) (struct request_queue *q);
 196 typedef int (make_request_fn) (struct request_queue *q, struct bio *bio);
 197 typedef int (prep_rq_fn) (struct request_queue *, struct request *);
 198 typedef void (unprep_rq_fn) (struct request_queue *, struct request *);
 199
 200 struct bio_vec;
 201 struct bvec_merge_data {
 202         struct block_device *bi_bdev;
 203         sector_t bi_sector;
 204         unsigned bi_size;
 205         unsigned long bi_rw;
 206 };
 207 typedef int (merge_bvec_fn) (struct request_queue *, struct bvec_merge_data *,
 208                              struct bio_vec *);
 209 typedef void (softirq_done_fn)(struct request *);
 210 typedef int (dma_drain_needed_fn)(struct request *);
 211 typedef int (lld_busy_fn) (struct request_queue *q);
 212
 213 enum blk_eh_timer_return {
 214         BLK_EH_NOT_HANDLED,
 215         BLK_EH_HANDLED,
 216         BLK_EH_RESET_TIMER,
 217 };
 218
 219 typedef enum blk_eh_timer_return (rq_timed_out_fn)(struct request *);
 220
 221 enum blk_queue_state {
 222         Queue_down,
 223         Queue_up,
 224 };
 225
 226 struct blk_queue_tag {
 227         struct request **tag_index;     /* map of busy tags */
 228         unsigned long *tag_map;         /* bit map of free/busy tags */
 229         int busy;                       /* current depth */
 230         int max_depth;                  /* what we will send to device */
 231         int real_max_depth;             /* what the array can hold */
 232         atomic_t refcnt;                /* map can be shared */
 233 };
 234
 235 #define BLK_SCSI_MAX_CMDS       (256)
 236 #define BLK_SCSI_CMD_PER_LONG   (BLK_SCSI_MAX_CMDS / (sizeof(long) * 8))
 237
 238 struct queue_limits {
 239         unsigned long           bounce_pfn;
 240         unsigned long           seg_boundary_mask;
 241
 242         unsigned int            max_hw_sectors;
 243         unsigned int            max_sectors;
 244         unsigned int            max_segment_size;
 245         unsigned int            physical_block_size;
 246         unsigned int            alignment_offset;
 247         unsigned int            io_min;
 248         unsigned int            io_opt;
 249         unsigned int            max_discard_sectors;
 250         unsigned int            discard_granularity;
 251         unsigned int            discard_alignment;
 252
 253         unsigned short          logical_block_size;
 254         unsigned short          max_segments;
 255         unsigned short          max_integrity_segments;
 256
 257         unsigned char           misaligned;
 258         unsigned char           discard_misaligned;
 259         unsigned char           cluster;
 260         signed char             discard_zeroes_data;
 261 };
 262
 263 struct request_queue
 264 {
 265         /*
 266          * Together with queue_head for cacheline sharing
 267          */
 268         struct list_head        queue_head;
 269         struct request          *last_merge;
 270         struct elevator_queue   *elevator;
 271
 272         /*
 273          * the queue request freelist, one for reads and one for writes
 274          */
 275         struct request_list     rq;
 276
 277         request_fn_proc         *request_fn;
 278         make_request_fn         *make_request_fn;
 279         prep_rq_fn              *prep_rq_fn;
 280         unprep_rq_fn            *unprep_rq_fn;
 281         merge_bvec_fn           *merge_bvec_fn;
 282         softirq_done_fn         *softirq_done_fn;
 283         rq_timed_out_fn         *rq_timed_out_fn;
 284         dma_drain_needed_fn     *dma_drain_needed;
 285         lld_busy_fn             *lld_busy_fn;
 286
 287         /*
 288          * Dispatch queue sorting
 289          */
 290         sector_t                end_sector;
 291         struct request          *boundary_rq;
 292
 293         /*
 294          * Delayed queue handling
 295          */
 296         struct delayed_work     delay_work;
 297
 298         struct backing_dev_info backing_dev_info;
 299
 300         /*
 301          * The queue owner gets to use this for whatever they like.
 302          * ll_rw_blk doesn't touch it.
 303          */
 304         void                    *queuedata;
 305
 306         /*
 307          * queue needs bounce pages for pages above this limit
 308          */
 309         gfp_t                   bounce_gfp;
 310
 311         /*
 312          * various queue flags, see QUEUE_* below
 313          */
 314         unsigned long           queue_flags;
 315
 316         /*
 317          * protects queue structures from reentrancy. ->__queue_lock should
 318          * _never_ be used directly, it is queue private. always use
 319          * ->queue_lock.
 320          */
 321         spinlock_t              __queue_lock;
 322         spinlock_t              *queue_lock;
 323
 324         /*
 325          * queue kobject
 326          */
 327         struct kobject kobj;
 328
 329         /*
 330          * queue settings
 331          */
 332         unsigned long           nr_requests;    /* Max # of requests */
 333         unsigned int            nr_congestion_on;
 334         unsigned int            nr_congestion_off;
 335         unsigned int            nr_batching;
 336
 337         void                    *dma_drain_buffer;
 338         unsigned int            dma_drain_size;
 339         unsigned int            dma_pad_mask;
 340         unsigned int            dma_alignment;
 341
 342         struct blk_queue_tag    *queue_tags;
 343         struct list_head        tag_busy_list;
 344
 345         unsigned int            nr_sorted;
 346         unsigned int            in_flight[2];
 347
 348         unsigned int            rq_timeout;
 349         struct timer_list       timeout;
 350         struct list_head        timeout_list;
 351
 352         struct queue_limits     limits;
 353
 354         /*
 355          * sg stuff
 356          */
 357         unsigned int            sg_timeout;
 358         unsigned int            sg_reserved_size;
 359         int                     node;
 360 #ifdef CONFIG_BLK_DEV_IO_TRACE
 361         struct blk_trace        *blk_trace;
 362 #endif
 363         /*
 364          * for flush operations
 365          */
 366         unsigned int            flush_flags;
 367         unsigned int            flush_pending_idx:1;
 368         unsigned int            flush_running_idx:1;
 369         unsigned long           flush_pending_since;
 370         struct list_head        flush_queue[2];
 371         struct list_head        flush_data_in_flight;
 372         struct request          flush_rq;
 373
 374         struct mutex            sysfs_lock;
 375
 376 #if defined(CONFIG_BLK_DEV_BSG)
 377         struct bsg_class_device bsg_dev;
 378 #endif
 379
 380 #ifdef CONFIG_BLK_DEV_THROTTLING
 381         /* Throttle data */
 382         struct throtl_data *td;
 383 #endif
 384 };
 385
 386 #define QUEUE_FLAG_QUEUED       1       /* uses generic tag queueing */
 387 #define QUEUE_FLAG_STOPPED      2       /* queue is stopped */
 388 #define QUEUE_FLAG_SYNCFULL     3       /* read queue has been filled */
 389 #define QUEUE_FLAG_ASYNCFULL    4       /* write queue has been filled */
 390 #define QUEUE_FLAG_DEAD         5       /* queue being torn down */
 391 #define QUEUE_FLAG_REENTER      6       /* Re-entrancy avoidance */
 392 #define QUEUE_FLAG_ELVSWITCH    7       /* don't use elevator, just do FIFO */
 393 #define QUEUE_FLAG_BIDI         8       /* queue supports bidi requests */
 394 #define QUEUE_FLAG_NOMERGES     9       /* disable merge attempts */
 395 #define QUEUE_FLAG_SAME_COMP   10       /* force complete on same CPU */
 396 #define QUEUE_FLAG_FAIL_IO     11       /* fake timeout */
 397 #define QUEUE_FLAG_STACKABLE   12       /* supports request stacking */
 398 #define QUEUE_FLAG_NONROT      13       /* 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_STACKABLE)    |       \
 408                                  (1 << QUEUE_FLAG_SAME_COMP)    |       \
 409                                  (1 << QUEUE_FLAG_ADD_RANDOM))
 410
 411 static inline int queue_is_locked(struct request_queue *q)
 412 {
 413 #ifdef CONFIG_SMP
 414         spinlock_t *lock = q->queue_lock;
 415         return lock && spin_is_locked(lock);
 416 #else
 417         return 1;
 418 #endif
 419 }
 420
 421 static inline void queue_flag_set_unlocked(unsigned int flag,
 422                                            struct request_queue *q)
 423 {
 424         __set_bit(flag, &q->queue_flags);
 425 }
 426
 427 static inline int queue_flag_test_and_clear(unsigned int flag,
 428                                             struct request_queue *q)
 429 {
 430         WARN_ON_ONCE(!queue_is_locked(q));
 431
 432         if (test_bit(flag, &q->queue_flags)) {
 433                 __clear_bit(flag, &q->queue_flags);
 434                 return 1;
 435         }
 436
 437         return 0;
 438 }
 439
 440 static inline int queue_flag_test_and_set(unsigned int flag,
 441                                           struct request_queue *q)
 442 {
 443         WARN_ON_ONCE(!queue_is_locked(q));
 444
 445         if (!test_bit(flag, &q->queue_flags)) {
 446                 __set_bit(flag, &q->queue_flags);
 447                 return 0;
 448         }
 449
 450         return 1;
 451 }
 452
 453 static inline void queue_flag_set(unsigned int flag, struct request_queue *q)
 454 {
 455         WARN_ON_ONCE(!queue_is_locked(q));
 456         __set_bit(flag, &q->queue_flags);
 457 }
 458
 459 static inline void queue_flag_clear_unlocked(unsigned int flag,
 460                                              struct request_queue *q)
 461 {
 462         __clear_bit(flag, &q->queue_flags);
 463 }
 464
 465 static inline int queue_in_flight(struct request_queue *q)
 466 {
 467         return q->in_flight[0] + q->in_flight[1];
 468 }
 469
 470 static inline void queue_flag_clear(unsigned int flag, struct request_queue *q)
 471 {
 472         WARN_ON_ONCE(!queue_is_locked(q));
 473         __clear_bit(flag, &q->queue_flags);
 474 }
 475
 476 #define blk_queue_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 generic_make_request(struct bio *bio);
 651 extern void blk_rq_init(struct request_queue *q, struct request *rq);
 652 extern void blk_put_request(struct request *);
 653 extern void __blk_put_request(struct request_queue *, struct request *);
 654 extern struct request *blk_get_request(struct request_queue *, int, gfp_t);
 655 extern struct request *blk_make_request(struct request_queue *, struct bio *,
 656                                         gfp_t);
 657 extern void blk_insert_request(struct request_queue *, struct request *, int, void *);
 658 extern void blk_requeue_request(struct request_queue *, struct request *);
 659 extern void blk_add_request_payload(struct request *rq, struct page *page,
 660                 unsigned int len);
 661 extern int blk_rq_check_limits(struct request_queue *q, struct request *rq);
 662 extern int blk_lld_busy(struct request_queue *q);
 663 extern int blk_rq_prep_clone(struct request *rq, struct request *rq_src,
 664                              struct bio_set *bs, gfp_t gfp_mask,
 665                              int (*bio_ctr)(struct bio *, struct bio *, void *),
 666                              void *data);
 667 extern void blk_rq_unprep_clone(struct request *rq);
 668 extern int blk_insert_cloned_request(struct request_queue *q,
 669                                      struct request *rq);
 670 extern void blk_delay_queue(struct request_queue *, unsigned long);
 671 extern void blk_recount_segments(struct request_queue *, struct bio *);
 672 extern int scsi_cmd_ioctl(struct request_queue *, struct gendisk *, fmode_t,
 673                           unsigned int, void __user *);
 674 extern int sg_scsi_ioctl(struct request_queue *, struct gendisk *, fmode_t,
 675                          struct scsi_ioctl_command __user *);
 676
 677 /*
 678  * A queue has just exitted congestion.  Note this in the global counter of
 679  * congested queues, and wake up anyone who was waiting for requests to be
 680  * put back.
 681  */
 682 static inline void blk_clear_queue_congested(struct request_queue *q, int sync)
 683 {
 684         clear_bdi_congested(&q->backing_dev_info, sync);
 685 }
 686
 687 /*
 688  * A queue has just entered congestion.  Flag that in the queue's VM-visible
 689  * state flags and increment the global gounter of congested queues.
 690  */
 691 static inline void blk_set_queue_congested(struct request_queue *q, int sync)
 692 {
 693         set_bdi_congested(&q->backing_dev_info, sync);
 694 }
 695
 696 extern void blk_start_queue(struct request_queue *q);
 697 extern void blk_stop_queue(struct request_queue *q);
 698 extern void blk_sync_queue(struct request_queue *q);
 699 extern void __blk_stop_queue(struct request_queue *q);
 700 extern void __blk_run_queue(struct request_queue *q, bool force_kblockd);
 701 extern void blk_run_queue(struct request_queue *);
 702 extern int blk_rq_map_user(struct request_queue *, struct request *,
 703                            struct rq_map_data *, void __user *, unsigned long,
 704                            gfp_t);
 705 extern int blk_rq_unmap_user(struct bio *);
 706 extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, unsigned int, gfp_t);
 707 extern int blk_rq_map_user_iov(struct request_queue *, struct request *,
 708                                struct rq_map_data *, struct sg_iovec *, int,
 709                                unsigned int, gfp_t);
 710 extern int blk_execute_rq(struct request_queue *, struct gendisk *,
 711                           struct request *, int);
 712 extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *,
 713                                   struct request *, int, rq_end_io_fn *);
 714
 715 static inline struct request_queue *bdev_get_queue(struct block_device *bdev)
 716 {
 717         return bdev->bd_disk->queue;
 718 }
 719
 720 /*
 721  * blk_rq_pos()                 : the current sector
 722  * blk_rq_bytes()               : bytes left in the entire request
 723  * blk_rq_cur_bytes()           : bytes left in the current segment
 724  * blk_rq_err_bytes()           : bytes left till the next error boundary
 725  * blk_rq_sectors()             : sectors left in the entire request
 726  * blk_rq_cur_sectors()         : sectors left in the current segment
 727  */
 728 static inline sector_t blk_rq_pos(const struct request *rq)
 729 {
 730         return rq->__sector;
 731 }
 732
 733 static inline unsigned int blk_rq_bytes(const struct request *rq)
 734 {
 735         return rq->__data_len;
 736 }
 737
 738 static inline int blk_rq_cur_bytes(const struct request *rq)
 739 {
 740         return rq->bio ? bio_cur_bytes(rq->bio) : 0;
 741 }
 742
 743 extern unsigned int blk_rq_err_bytes(const struct request *rq);
 744
 745 static inline unsigned int blk_rq_sectors(const struct request *rq)
 746 {
 747         return blk_rq_bytes(rq) >> 9;
 748 }
 749
 750 static inline unsigned int blk_rq_cur_sectors(const struct request *rq)
 751 {
 752         return blk_rq_cur_bytes(rq) >> 9;
 753 }
 754
 755 /*
 756  * Request issue related functions.
 757  */
 758 extern struct request *blk_peek_request(struct request_queue *q);
 759 extern void blk_start_request(struct request *rq);
 760 extern struct request *blk_fetch_request(struct request_queue *q);
 761
 762 /*
 763  * Request completion related functions.
 764  *
 765  * blk_update_request() completes given number of bytes and updates
 766  * the request without completing it.
 767  *
 768  * blk_end_request() and friends.  __blk_end_request() must be called
 769  * with the request queue spinlock acquired.
 770  *
 771  * Several drivers define their own end_request and call
 772  * blk_end_request() for parts of the original function.
 773  * This prevents code duplication in drivers.
 774  */
 775 extern bool blk_update_request(struct request *rq, int error,
 776                                unsigned int nr_bytes);
 777 extern bool blk_end_request(struct request *rq, int error,
 778                             unsigned int nr_bytes);
 779 extern void blk_end_request_all(struct request *rq, int error);
 780 extern bool blk_end_request_cur(struct request *rq, int error);
 781 extern bool blk_end_request_err(struct request *rq, int error);
 782 extern bool __blk_end_request(struct request *rq, int error,
 783                               unsigned int nr_bytes);
 784 extern void __blk_end_request_all(struct request *rq, int error);
 785 extern bool __blk_end_request_cur(struct request *rq, int error);
 786 extern bool __blk_end_request_err(struct request *rq, int error);
 787
 788 extern void blk_complete_request(struct request *);
 789 extern void __blk_complete_request(struct request *);
 790 extern void blk_abort_request(struct request *);
 791 extern void blk_abort_queue(struct request_queue *);
 792 extern void blk_unprep_request(struct request *);
 793
 794 /*
 795  * Access functions for manipulating queue properties
 796  */
 797 extern struct request_queue *blk_init_queue_node(request_fn_proc *rfn,
 798                                         spinlock_t *lock, int node_id);
 799 extern struct request_queue *blk_init_allocated_queue_node(struct request_queue *,
 800                                                            request_fn_proc *,
 801                                                            spinlock_t *, int node_id);
 802 extern struct request_queue *blk_init_queue(request_fn_proc *, spinlock_t *);
 803 extern struct request_queue *blk_init_allocated_queue(struct request_queue *,
 804                                                       request_fn_proc *, spinlock_t *);
 805 extern void blk_cleanup_queue(struct request_queue *);
 806 extern void blk_queue_make_request(struct request_queue *, make_request_fn *);
 807 extern void blk_queue_bounce_limit(struct request_queue *, u64);
 808 extern void blk_limits_max_hw_sectors(struct queue_limits *, unsigned int);
 809 extern void blk_queue_max_hw_sectors(struct request_queue *, unsigned int);
 810 extern void blk_queue_max_segments(struct request_queue *, unsigned short);
 811 extern void blk_queue_max_segment_size(struct request_queue *, unsigned int);
 812 extern void blk_queue_max_discard_sectors(struct request_queue *q,
 813                 unsigned int max_discard_sectors);
 814 extern void blk_queue_logical_block_size(struct request_queue *, unsigned short);
 815 extern void blk_queue_physical_block_size(struct request_queue *, unsigned int);
 816 extern void blk_queue_alignment_offset(struct request_queue *q,
 817                                        unsigned int alignment);
 818 extern void blk_limits_io_min(struct queue_limits *limits, unsigned int min);
 819 extern void blk_queue_io_min(struct request_queue *q, unsigned int min);
 820 extern void blk_limits_io_opt(struct queue_limits *limits, unsigned int opt);
 821 extern void blk_queue_io_opt(struct request_queue *q, unsigned int opt);
 822 extern void blk_set_default_limits(struct queue_limits *lim);
 823 extern int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
 824                             sector_t offset);
 825 extern int bdev_stack_limits(struct queue_limits *t, struct block_device *bdev,
 826                             sector_t offset);
 827 extern void disk_stack_limits(struct gendisk *disk, struct block_device *bdev,
 828                               sector_t offset);
 829 extern void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b);
 830 extern void blk_queue_dma_pad(struct request_queue *, unsigned int);
 831 extern void blk_queue_update_dma_pad(struct request_queue *, unsigned int);
 832 extern int blk_queue_dma_drain(struct request_queue *q,
 833                                dma_drain_needed_fn *dma_drain_needed,
 834                                void *buf, unsigned int size);
 835 extern void blk_queue_lld_busy(struct request_queue *q, lld_busy_fn *fn);
 836 extern void blk_queue_segment_boundary(struct request_queue *, unsigned long);
 837 extern void blk_queue_prep_rq(struct request_queue *, prep_rq_fn *pfn);
 838 extern void blk_queue_unprep_rq(struct request_queue *, unprep_rq_fn *ufn);
 839 extern void blk_queue_merge_bvec(struct request_queue *, merge_bvec_fn *);
 840 extern void blk_queue_dma_alignment(struct request_queue *, int);
 841 extern void blk_queue_update_dma_alignment(struct request_queue *, int);
 842 extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *);
 843 extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *);
 844 extern void blk_queue_rq_timeout(struct request_queue *, unsigned int);
 845 extern void blk_queue_flush(struct request_queue *q, unsigned int flush);
 846 extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev);
 847
 848 extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *);
 849 extern void blk_dump_rq_flags(struct request *, char *);
 850 extern long nr_blockdev_pages(void);
 851
 852 int blk_get_queue(struct request_queue *);
 853 struct request_queue *blk_alloc_queue(gfp_t);
 854 struct request_queue *blk_alloc_queue_node(gfp_t, int);
 855 extern void blk_put_queue(struct request_queue *);
 856
 857 struct blk_plug {
 858         unsigned long magic;
 859         struct list_head list;
 860         unsigned int should_sort;
 861 };
 862
 863 extern void blk_start_plug(struct blk_plug *);
 864 extern void blk_finish_plug(struct blk_plug *);
 865 extern void __blk_flush_plug(struct task_struct *, struct blk_plug *);
 866
 867 static inline void blk_flush_plug(struct task_struct *tsk)
 868 {
 869         struct blk_plug *plug = tsk->plug;
 870
 871         if (unlikely(plug))
 872                 __blk_flush_plug(tsk, plug);
 873 }
 874
 875 static inline bool blk_needs_flush_plug(struct task_struct *tsk)
 876 {
 877         struct blk_plug *plug = tsk->plug;
 878
 879         return plug && !list_empty(&plug->list);
 880 }
 881
 882 /*
 883  * tag stuff
 884  */
 885 #define blk_rq_tagged(rq)               ((rq)->cmd_flags & REQ_QUEUED)
 886 extern int blk_queue_start_tag(struct request_queue *, struct request *);
 887 extern struct request *blk_queue_find_tag(struct request_queue *, int);
 888 extern void blk_queue_end_tag(struct request_queue *, struct request *);
 889 extern int blk_queue_init_tags(struct request_queue *, int, struct blk_queue_tag *);
 890 extern void blk_queue_free_tags(struct request_queue *);
 891 extern int blk_queue_resize_tags(struct request_queue *, int);
 892 extern void blk_queue_invalidate_tags(struct request_queue *);
 893 extern struct blk_queue_tag *blk_init_tags(int);
 894 extern void blk_free_tags(struct blk_queue_tag *);
 895
 896 static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt,
 897                                                 int tag)
 898 {
 899         if (unlikely(bqt == NULL || tag >= bqt->real_max_depth))
 900                 return NULL;
 901         return bqt->tag_index[tag];
 902 }
 903
 904 #define BLKDEV_DISCARD_SECURE  0x01    /* secure discard */
 905
 906 extern int blkdev_issue_flush(struct block_device *, gfp_t, sector_t *);
 907 extern int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
 908                 sector_t nr_sects, gfp_t gfp_mask, unsigned long flags);
 909 extern int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
 910                         sector_t nr_sects, gfp_t gfp_mask);
 911 static inline int sb_issue_discard(struct super_block *sb, sector_t block,
 912                 sector_t nr_blocks, gfp_t gfp_mask, unsigned long flags)
 913 {
 914         return blkdev_issue_discard(sb->s_bdev, block << (sb->s_blocksize_bits - 9),
 915                                     nr_blocks << (sb->s_blocksize_bits - 9),
 916                                     gfp_mask, flags);
 917 }
 918 static inline int sb_issue_zeroout(struct super_block *sb, sector_t block,
 919                 sector_t nr_blocks, gfp_t gfp_mask)
 920 {
 921         return blkdev_issue_zeroout(sb->s_bdev,
 922                                     block << (sb->s_blocksize_bits - 9),
 923                                     nr_blocks << (sb->s_blocksize_bits - 9),
 924                                     gfp_mask);
 925 }
 926
 927 extern int blk_verify_command(unsigned char *cmd, fmode_t has_write_perm);
 928
 929 enum blk_default_limits {
 930         BLK_MAX_SEGMENTS        = 128,
 931         BLK_SAFE_MAX_SECTORS    = 255,
 932         BLK_DEF_MAX_SECTORS     = 1024,
 933         BLK_MAX_SEGMENT_SIZE    = 65536,
 934         BLK_SEG_BOUNDARY_MASK   = 0xFFFFFFFFUL,
 935 };
 936
 937 #define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist)
 938
 939 static inline unsigned long queue_bounce_pfn(struct request_queue *q)
 940 {
 941         return q->limits.bounce_pfn;
 942 }
 943
 944 static inline unsigned long queue_segment_boundary(struct request_queue *q)
 945 {
 946         return q->limits.seg_boundary_mask;
 947 }
 948
 949 static inline unsigned int queue_max_sectors(struct request_queue *q)
 950 {
 951         return q->limits.max_sectors;
 952 }
 953
 954 static inline unsigned int queue_max_hw_sectors(struct request_queue *q)
 955 {
 956         return q->limits.max_hw_sectors;
 957 }
 958
 959 static inline unsigned short queue_max_segments(struct request_queue *q)
 960 {
 961         return q->limits.max_segments;
 962 }
 963
 964 static inline unsigned int queue_max_segment_size(struct request_queue *q)
 965 {
 966         return q->limits.max_segment_size;
 967 }
 968
 969 static inline unsigned short queue_logical_block_size(struct request_queue *q)
 970 {
 971         int retval = 512;
 972
 973         if (q && q->limits.logical_block_size)
 974                 retval = q->limits.logical_block_size;
 975
 976         return retval;
 977 }
 978
 979 static inline unsigned short bdev_logical_block_size(struct block_device *bdev)
 980 {
 981         return queue_logical_block_size(bdev_get_queue(bdev));
 982 }
 983
 984 static inline unsigned int queue_physical_block_size(struct request_queue *q)
 985 {
 986         return q->limits.physical_block_size;
 987 }
 988
 989 static inline unsigned int bdev_physical_block_size(struct block_device *bdev)
 990 {
 991         return queue_physical_block_size(bdev_get_queue(bdev));
 992 }
 993
 994 static inline unsigned int queue_io_min(struct request_queue *q)
 995 {
 996         return q->limits.io_min;
 997 }
 998
 999 static inline int bdev_io_min(struct block_device *bdev)
1000 {
1001         return queue_io_min(bdev_get_queue(bdev));
1002 }
1003
1004 static inline unsigned int queue_io_opt(struct request_queue *q)
1005 {
1006         return q->limits.io_opt;
1007 }
1008
1009 static inline int bdev_io_opt(struct block_device *bdev)
1010 {
1011         return queue_io_opt(bdev_get_queue(bdev));
1012 }
1013
1014 static inline int queue_alignment_offset(struct request_queue *q)
1015 {
1016         if (q->limits.misaligned)
1017                 return -1;
1018
1019         return q->limits.alignment_offset;
1020 }
1021
1022 static inline int queue_limit_alignment_offset(struct queue_limits *lim, sector_t sector)
1023 {
1024         unsigned int granularity = max(lim->physical_block_size, lim->io_min);
1025         unsigned int alignment = (sector << 9) & (granularity - 1);
1026
1027         return (granularity + lim->alignment_offset - alignment)
1028                 & (granularity - 1);
1029 }
1030
1031 static inline int bdev_alignment_offset(struct block_device *bdev)
1032 {
1033         struct request_queue *q = bdev_get_queue(bdev);
1034
1035         if (q->limits.misaligned)
1036                 return -1;
1037
1038         if (bdev != bdev->bd_contains)
1039                 return bdev->bd_part->alignment_offset;
1040
1041         return q->limits.alignment_offset;
1042 }
1043
1044 static inline int queue_discard_alignment(struct request_queue *q)
1045 {
1046         if (q->limits.discard_misaligned)
1047                 return -1;
1048
1049         return q->limits.discard_alignment;
1050 }
1051
1052 static inline int queue_limit_discard_alignment(struct queue_limits *lim, sector_t sector)
1053 {
1054         unsigned int alignment = (sector << 9) & (lim->discard_granularity - 1);
1055
1056         return (lim->discard_granularity + lim->discard_alignment - alignment)
1057                 & (lim->discard_granularity - 1);
1058 }
1059
1060 static inline unsigned int queue_discard_zeroes_data(struct request_queue *q)
1061 {
1062         if (q->limits.discard_zeroes_data == 1)
1063                 return 1;
1064
1065         return 0;
1066 }
1067
1068 static inline unsigned int bdev_discard_zeroes_data(struct block_device *bdev)
1069 {
1070         return queue_discard_zeroes_data(bdev_get_queue(bdev));
1071 }
1072
1073 static inline int queue_dma_alignment(struct request_queue *q)
1074 {
1075         return q ? q->dma_alignment : 511;
1076 }
1077
1078 static inline int blk_rq_aligned(struct request_queue *q, unsigned long addr,
1079                                  unsigned int len)
1080 {
1081         unsigned int alignment = queue_dma_alignment(q) | q->dma_pad_mask;
1082         return !(addr & alignment) && !(len & alignment);
1083 }
1084
1085 /* assumes size > 256 */
1086 static inline unsigned int blksize_bits(unsigned int size)
1087 {
1088         unsigned int bits = 8;
1089         do {
1090                 bits++;
1091                 size >>= 1;
1092         } while (size > 256);
1093         return bits;
1094 }
1095
1096 static inline unsigned int block_size(struct block_device *bdev)
1097 {
1098         return bdev->bd_block_size;
1099 }
1100
1101 typedef struct {struct page *v;} Sector;
1102
1103 unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *);
1104
1105 static inline void put_dev_sector(Sector p)
1106 {
1107         page_cache_release(p.v);
1108 }
1109
1110 struct work_struct;
1111 int kblockd_schedule_work(struct request_queue *q, struct work_struct *work);
1112
1113 #ifdef CONFIG_BLK_CGROUP
1114 /*
1115  * This should not be using sched_clock(). A real patch is in progress
1116  * to fix this up, until that is in place we need to disable preemption
1117  * around sched_clock() in this function and set_io_start_time_ns().
1118  */
1119 static inline void set_start_time_ns(struct request *req)
1120 {
1121         preempt_disable();
1122         req->start_time_ns = sched_clock();
1123         preempt_enable();
1124 }
1125
1126 static inline void set_io_start_time_ns(struct request *req)
1127 {
1128         preempt_disable();
1129         req->io_start_time_ns = sched_clock();
1130         preempt_enable();
1131 }
1132
1133 static inline uint64_t rq_start_time_ns(struct request *req)
1134 {
1135         return req->start_time_ns;
1136 }
1137
1138 static inline uint64_t rq_io_start_time_ns(struct request *req)
1139 {
1140         return req->io_start_time_ns;
1141 }
1142 #else
1143 static inline void set_start_time_ns(struct request *req) {}
1144 static inline void set_io_start_time_ns(struct request *req) {}
1145 static inline uint64_t rq_start_time_ns(struct request *req)
1146 {
1147         return 0;
1148 }
1149 static inline uint64_t rq_io_start_time_ns(struct request *req)
1150 {
1151         return 0;
1152 }
1153 #endif
1154
1155 #ifdef CONFIG_BLK_DEV_THROTTLING
1156 extern int blk_throtl_init(struct request_queue *q);
1157 extern void blk_throtl_exit(struct request_queue *q);
1158 extern int blk_throtl_bio(struct request_queue *q, struct bio **bio);
1159 #else /* CONFIG_BLK_DEV_THROTTLING */
1160 static inline int blk_throtl_bio(struct request_queue *q, struct bio **bio)
1161 {
1162         return 0;
1163 }
1164
1165 static inline int blk_throtl_init(struct request_queue *q) { return 0; }
1166 static inline int blk_throtl_exit(struct request_queue *q) { return 0; }
1167 #endif /* CONFIG_BLK_DEV_THROTTLING */
1168
1169 #define MODULE_ALIAS_BLOCKDEV(major,minor) \
1170         MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor))
1171 #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \
1172         MODULE_ALIAS("block-major-" __stringify(major) "-*")
1173
1174 #if defined(CONFIG_BLK_DEV_INTEGRITY)
1175
1176 #define INTEGRITY_FLAG_READ     2       /* verify data integrity on read */
1177 #define INTEGRITY_FLAG_WRITE    4       /* generate data integrity on write */
1178
1179 struct blk_integrity_exchg {
1180         void                    *prot_buf;
1181         void                    *data_buf;
1182         sector_t                sector;
1183         unsigned int            data_size;
1184         unsigned short          sector_size;
1185         const char              *disk_name;
1186 };
1187
1188 typedef void (integrity_gen_fn) (struct blk_integrity_exchg *);
1189 typedef int (integrity_vrfy_fn) (struct blk_integrity_exchg *);
1190 typedef void (integrity_set_tag_fn) (void *, void *, unsigned int);
1191 typedef void (integrity_get_tag_fn) (void *, void *, unsigned int);
1192
1193 struct blk_integrity {
1194         integrity_gen_fn        *generate_fn;
1195         integrity_vrfy_fn       *verify_fn;
1196         integrity_set_tag_fn    *set_tag_fn;
1197         integrity_get_tag_fn    *get_tag_fn;
1198
1199         unsigned short          flags;
1200         unsigned short          tuple_size;
1201         unsigned short          sector_size;
1202         unsigned short          tag_size;
1203
1204         const char              *name;
1205
1206         struct kobject          kobj;
1207 };
1208
1209 extern int blk_integrity_register(struct gendisk *, struct blk_integrity *);
1210 extern void blk_integrity_unregister(struct gendisk *);
1211 extern int blk_integrity_compare(struct gendisk *, struct gendisk *);
1212 extern int blk_rq_map_integrity_sg(struct request_queue *, struct bio *,
1213                                    struct scatterlist *);
1214 extern int blk_rq_count_integrity_sg(struct request_queue *, struct bio *);
1215 extern int blk_integrity_merge_rq(struct request_queue *, struct request *,
1216                                   struct request *);
1217 extern int blk_integrity_merge_bio(struct request_queue *, struct request *,
1218                                    struct bio *);
1219
1220 static inline
1221 struct blk_integrity *bdev_get_integrity(struct block_device *bdev)
1222 {
1223         return bdev->bd_disk->integrity;
1224 }
1225
1226 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk)
1227 {
1228         return disk->integrity;
1229 }
1230
1231 static inline int blk_integrity_rq(struct request *rq)
1232 {
1233         if (rq->bio == NULL)
1234                 return 0;
1235
1236         return bio_integrity(rq->bio);
1237 }
1238
1239 static inline void blk_queue_max_integrity_segments(struct request_queue *q,
1240                                                     unsigned int segs)
1241 {
1242         q->limits.max_integrity_segments = segs;
1243 }
1244
1245 static inline unsigned short
1246 queue_max_integrity_segments(struct request_queue *q)
1247 {
1248         return q->limits.max_integrity_segments;
1249 }
1250
1251 #else /* CONFIG_BLK_DEV_INTEGRITY */
1252
1253 #define blk_integrity_rq(rq)                    (0)
1254 #define blk_rq_count_integrity_sg(a, b)         (0)
1255 #define blk_rq_map_integrity_sg(a, b, c)        (0)
1256 #define bdev_get_integrity(a)                   (0)
1257 #define blk_get_integrity(a)                    (0)
1258 #define blk_integrity_compare(a, b)             (0)
1259 #define blk_integrity_register(a, b)            (0)
1260 #define blk_integrity_unregister(a)             do { } while (0);
1261 #define blk_queue_max_integrity_segments(a, b)  do { } while (0);
1262 #define queue_max_integrity_segments(a)         (0)
1263 #define blk_integrity_merge_rq(a, b, c)         (0)
1264 #define blk_integrity_merge_bio(a, b, c)        (0)
1265
1266 #endif /* CONFIG_BLK_DEV_INTEGRITY */
1267
1268 struct block_device_operations {
1269         int (*open) (struct block_device *, fmode_t);
1270         int (*release) (struct gendisk *, fmode_t);
1271         int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1272         int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1273         int (*direct_access) (struct block_device *, sector_t,
1274                                                 void **, unsigned long *);
1275         unsigned int (*check_events) (struct gendisk *disk,
1276                                       unsigned int clearing);
1277         /* ->media_changed() is DEPRECATED, use ->check_events() instead */
1278         int (*media_changed) (struct gendisk *);
1279         void (*unlock_native_capacity) (struct gendisk *);
1280         int (*revalidate_disk) (struct gendisk *);
1281         int (*getgeo)(struct block_device *, struct hd_geometry *);
1282         /* this callback is with swap_lock and sometimes page table lock held */
1283         void (*swap_slot_free_notify) (struct block_device *, unsigned long);
1284         struct module *owner;
1285 };
1286
1287 extern int __blkdev_driver_ioctl(struct block_device *, fmode_t, unsigned int,
1288                                  unsigned long);
1289 #else /* CONFIG_BLOCK */
1290 /*
1291  * stubs for when the block layer is configured out
1292  */
1293 #define buffer_heads_over_limit 0
1294
1295 static inline long nr_blockdev_pages(void)
1296 {
1297         return 0;
1298 }
1299
1300 struct blk_plug {
1301 };
1302
1303 static inline void blk_start_plug(struct blk_plug *plug)
1304 {
1305 }
1306
1307 static inline void blk_finish_plug(struct blk_plug *plug)
1308 {
1309 }
1310
1311 static inline void blk_flush_plug(struct task_struct *task)
1312 {
1313 }
1314
1315 static inline bool blk_needs_flush_plug(struct task_struct *tsk)
1316 {
1317         return false;
1318 }
1319
1320 #endif /* CONFIG_BLOCK */
1321
1322 #endif