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         unsigned 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_not_queueable:1;
 368         unsigned int            flush_queue_delayed:1;
 369         unsigned int            flush_pending_idx:1;
 370         unsigned int            flush_running_idx:1;
 371         unsigned long           flush_pending_since;
 372         struct list_head        flush_queue[2];
 373         struct list_head        flush_data_in_flight;
 374         struct request          flush_rq;
 375
 376         struct mutex            sysfs_lock;
 377
 378 #if defined(CONFIG_BLK_DEV_BSG)
 379         struct bsg_class_device bsg_dev;
 380 #endif
 381
 382 #ifdef CONFIG_BLK_DEV_THROTTLING
 383         /* Throttle data */
 384         struct throtl_data *td;
 385 #endif
 386 };
 387
 388 #define QUEUE_FLAG_QUEUED       1       /* uses generic tag queueing */
 389 #define QUEUE_FLAG_STOPPED      2       /* queue is stopped */
 390 #define QUEUE_FLAG_SYNCFULL     3       /* read queue has been filled */
 391 #define QUEUE_FLAG_ASYNCFULL    4       /* write queue has been filled */
 392 #define QUEUE_FLAG_DEAD         5       /* queue being torn down */
 393 #define QUEUE_FLAG_ELVSWITCH    6       /* don't use elevator, just do FIFO */
 394 #define QUEUE_FLAG_BIDI         7       /* queue supports bidi requests */
 395 #define QUEUE_FLAG_NOMERGES     8       /* disable merge attempts */
 396 #define QUEUE_FLAG_SAME_COMP    9       /* force complete on same CPU */
 397 #define QUEUE_FLAG_FAIL_IO     10       /* fake timeout */
 398 #define QUEUE_FLAG_STACKABLE   11       /* supports request stacking */
 399 #define QUEUE_FLAG_NONROT      12       /* non-rotational device (SSD) */
 400 #define QUEUE_FLAG_VIRT        QUEUE_FLAG_NONROT /* paravirt device */
 401 #define QUEUE_FLAG_IO_STAT     13       /* do IO stats */
 402 #define QUEUE_FLAG_DISCARD     14       /* supports DISCARD */
 403 #define QUEUE_FLAG_NOXMERGES   15       /* No extended merges */
 404 #define QUEUE_FLAG_ADD_RANDOM  16       /* Contributes to random pool */
 405 #define QUEUE_FLAG_SECDISCARD  17       /* supports SECDISCARD */
 406
 407 #define QUEUE_FLAG_DEFAULT      ((1 << QUEUE_FLAG_IO_STAT) |            \
 408                                  (1 << QUEUE_FLAG_STACKABLE)    |       \
 409                                  (1 << QUEUE_FLAG_SAME_COMP)    |       \
 410                                  (1 << QUEUE_FLAG_ADD_RANDOM))
 411
 412 static inline int queue_is_locked(struct request_queue *q)
 413 {
 414 #ifdef CONFIG_SMP
 415         spinlock_t *lock = q->queue_lock;
 416         return lock && spin_is_locked(lock);
 417 #else
 418         return 1;
 419 #endif
 420 }
 421
 422 static inline void queue_flag_set_unlocked(unsigned int flag,
 423                                            struct request_queue *q)
 424 {
 425         __set_bit(flag, &q->queue_flags);
 426 }
 427
 428 static inline int queue_flag_test_and_clear(unsigned int flag,
 429                                             struct request_queue *q)
 430 {
 431         WARN_ON_ONCE(!queue_is_locked(q));
 432
 433         if (test_bit(flag, &q->queue_flags)) {
 434                 __clear_bit(flag, &q->queue_flags);
 435                 return 1;
 436         }
 437
 438         return 0;
 439 }
 440
 441 static inline int queue_flag_test_and_set(unsigned int flag,
 442                                           struct request_queue *q)
 443 {
 444         WARN_ON_ONCE(!queue_is_locked(q));
 445
 446         if (!test_bit(flag, &q->queue_flags)) {
 447                 __set_bit(flag, &q->queue_flags);
 448                 return 0;
 449         }
 450
 451         return 1;
 452 }
 453
 454 static inline void queue_flag_set(unsigned int flag, struct request_queue *q)
 455 {
 456         WARN_ON_ONCE(!queue_is_locked(q));
 457         __set_bit(flag, &q->queue_flags);
 458 }
 459
 460 static inline void queue_flag_clear_unlocked(unsigned int flag,
 461                                              struct request_queue *q)
 462 {
 463         __clear_bit(flag, &q->queue_flags);
 464 }
 465
 466 static inline int queue_in_flight(struct request_queue *q)
 467 {
 468         return q->in_flight[0] + q->in_flight[1];
 469 }
 470
 471 static inline void queue_flag_clear(unsigned int flag, struct request_queue *q)
 472 {
 473         WARN_ON_ONCE(!queue_is_locked(q));
 474         __clear_bit(flag, &q->queue_flags);
 475 }
 476
 477 #define blk_queue_tagged(q)     test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags)
 478 #define blk_queue_stopped(q)    test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
 479 #define blk_queue_nomerges(q)   test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags)
 480 #define blk_queue_noxmerges(q)  \
 481         test_bit(QUEUE_FLAG_NOXMERGES, &(q)->queue_flags)
 482 #define blk_queue_nonrot(q)     test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags)
 483 #define blk_queue_io_stat(q)    test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags)
 484 #define blk_queue_add_random(q) test_bit(QUEUE_FLAG_ADD_RANDOM, &(q)->queue_flags)
 485 #define blk_queue_stackable(q)  \
 486         test_bit(QUEUE_FLAG_STACKABLE, &(q)->queue_flags)
 487 #define blk_queue_discard(q)    test_bit(QUEUE_FLAG_DISCARD, &(q)->queue_flags)
 488 #define blk_queue_secdiscard(q) (blk_queue_discard(q) && \
 489         test_bit(QUEUE_FLAG_SECDISCARD, &(q)->queue_flags))
 490
 491 #define blk_noretry_request(rq) \
 492         ((rq)->cmd_flags & (REQ_FAILFAST_DEV|REQ_FAILFAST_TRANSPORT| \
 493                              REQ_FAILFAST_DRIVER))
 494
 495 #define blk_account_rq(rq) \
 496         (((rq)->cmd_flags & REQ_STARTED) && \
 497          ((rq)->cmd_type == REQ_TYPE_FS || \
 498           ((rq)->cmd_flags & REQ_DISCARD)))
 499
 500 #define blk_pm_request(rq)      \
 501         ((rq)->cmd_type == REQ_TYPE_PM_SUSPEND || \
 502          (rq)->cmd_type == REQ_TYPE_PM_RESUME)
 503
 504 #define blk_rq_cpu_valid(rq)    ((rq)->cpu != -1)
 505 #define blk_bidi_rq(rq)         ((rq)->next_rq != NULL)
 506 /* rq->queuelist of dequeued request must be list_empty() */
 507 #define blk_queued_rq(rq)       (!list_empty(&(rq)->queuelist))
 508
 509 #define list_entry_rq(ptr)      list_entry((ptr), struct request, queuelist)
 510
 511 #define rq_data_dir(rq)         ((rq)->cmd_flags & 1)
 512
 513 static inline unsigned int blk_queue_cluster(struct request_queue *q)
 514 {
 515         return q->limits.cluster;
 516 }
 517
 518 /*
 519  * We regard a request as sync, if either a read or a sync write
 520  */
 521 static inline bool rw_is_sync(unsigned int rw_flags)
 522 {
 523         return !(rw_flags & REQ_WRITE) || (rw_flags & REQ_SYNC);
 524 }
 525
 526 static inline bool rq_is_sync(struct request *rq)
 527 {
 528         return rw_is_sync(rq->cmd_flags);
 529 }
 530
 531 static inline int blk_queue_full(struct request_queue *q, int sync)
 532 {
 533         if (sync)
 534                 return test_bit(QUEUE_FLAG_SYNCFULL, &q->queue_flags);
 535         return test_bit(QUEUE_FLAG_ASYNCFULL, &q->queue_flags);
 536 }
 537
 538 static inline void blk_set_queue_full(struct request_queue *q, int sync)
 539 {
 540         if (sync)
 541                 queue_flag_set(QUEUE_FLAG_SYNCFULL, q);
 542         else
 543                 queue_flag_set(QUEUE_FLAG_ASYNCFULL, q);
 544 }
 545
 546 static inline void blk_clear_queue_full(struct request_queue *q, int sync)
 547 {
 548         if (sync)
 549                 queue_flag_clear(QUEUE_FLAG_SYNCFULL, q);
 550         else
 551                 queue_flag_clear(QUEUE_FLAG_ASYNCFULL, q);
 552 }
 553
 554
 555 /*
 556  * mergeable request must not have _NOMERGE or _BARRIER bit set, nor may
 557  * it already be started by driver.
 558  */
 559 #define RQ_NOMERGE_FLAGS        \
 560         (REQ_NOMERGE | REQ_STARTED | REQ_SOFTBARRIER | REQ_FLUSH | REQ_FUA)
 561 #define rq_mergeable(rq)        \
 562         (!((rq)->cmd_flags & RQ_NOMERGE_FLAGS) && \
 563          (((rq)->cmd_flags & REQ_DISCARD) || \
 564           (rq)->cmd_type == REQ_TYPE_FS))
 565
 566 /*
 567  * q->prep_rq_fn return values
 568  */
 569 #define BLKPREP_OK              0       /* serve it */
 570 #define BLKPREP_KILL            1       /* fatal error, kill */
 571 #define BLKPREP_DEFER           2       /* leave on queue */
 572
 573 extern unsigned long blk_max_low_pfn, blk_max_pfn;
 574
 575 /*
 576  * standard bounce addresses:
 577  *
 578  * BLK_BOUNCE_HIGH      : bounce all highmem pages
 579  * BLK_BOUNCE_ANY       : don't bounce anything
 580  * BLK_BOUNCE_ISA       : bounce pages above ISA DMA boundary
 581  */
 582
 583 #if BITS_PER_LONG == 32
 584 #define BLK_BOUNCE_HIGH         ((u64)blk_max_low_pfn << PAGE_SHIFT)
 585 #else
 586 #define BLK_BOUNCE_HIGH         -1ULL
 587 #endif
 588 #define BLK_BOUNCE_ANY          (-1ULL)
 589 #define BLK_BOUNCE_ISA          (DMA_BIT_MASK(24))
 590
 591 /*
 592  * default timeout for SG_IO if none specified
 593  */
 594 #define BLK_DEFAULT_SG_TIMEOUT  (60 * HZ)
 595 #define BLK_MIN_SG_TIMEOUT      (7 * HZ)
 596
 597 #ifdef CONFIG_BOUNCE
 598 extern int init_emergency_isa_pool(void);
 599 extern void blk_queue_bounce(struct request_queue *q, struct bio **bio);
 600 #else
 601 static inline int init_emergency_isa_pool(void)
 602 {
 603         return 0;
 604 }
 605 static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio)
 606 {
 607 }
 608 #endif /* CONFIG_MMU */
 609
 610 struct rq_map_data {
 611         struct page **pages;
 612         int page_order;
 613         int nr_entries;
 614         unsigned long offset;
 615         int null_mapped;
 616         int from_user;
 617 };
 618
 619 struct req_iterator {
 620         int i;
 621         struct bio *bio;
 622 };
 623
 624 /* This should not be used directly - use rq_for_each_segment */
 625 #define for_each_bio(_bio)              \
 626         for (; _bio; _bio = _bio->bi_next)
 627 #define __rq_for_each_bio(_bio, rq)     \
 628         if ((rq->bio))                  \
 629                 for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next)
 630
 631 #define rq_for_each_segment(bvl, _rq, _iter)                    \
 632         __rq_for_each_bio(_iter.bio, _rq)                       \
 633                 bio_for_each_segment(bvl, _iter.bio, _iter.i)
 634
 635 #define rq_iter_last(rq, _iter)                                 \
 636                 (_iter.bio->bi_next == NULL && _iter.i == _iter.bio->bi_vcnt-1)
 637
 638 #ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
 639 # error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform"
 640 #endif
 641 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
 642 extern void rq_flush_dcache_pages(struct request *rq);
 643 #else
 644 static inline void rq_flush_dcache_pages(struct request *rq)
 645 {
 646 }
 647 #endif
 648
 649 extern int blk_register_queue(struct gendisk *disk);
 650 extern void blk_unregister_queue(struct gendisk *disk);
 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_delay_queue(struct request_queue *, unsigned long);
 672 extern void blk_recount_segments(struct request_queue *, struct bio *);
 673 extern int scsi_cmd_ioctl(struct request_queue *, struct gendisk *, fmode_t,
 674                           unsigned int, void __user *);
 675 extern int sg_scsi_ioctl(struct request_queue *, struct gendisk *, fmode_t,
 676                          struct scsi_ioctl_command __user *);
 677
 678 /*
 679  * A queue has just exitted congestion.  Note this in the global counter of
 680  * congested queues, and wake up anyone who was waiting for requests to be
 681  * put back.
 682  */
 683 static inline void blk_clear_queue_congested(struct request_queue *q, int sync)
 684 {
 685         clear_bdi_congested(&q->backing_dev_info, sync);
 686 }
 687
 688 /*
 689  * A queue has just entered congestion.  Flag that in the queue's VM-visible
 690  * state flags and increment the global gounter of congested queues.
 691  */
 692 static inline void blk_set_queue_congested(struct request_queue *q, int sync)
 693 {
 694         set_bdi_congested(&q->backing_dev_info, sync);
 695 }
 696
 697 extern void blk_start_queue(struct request_queue *q);
 698 extern void blk_stop_queue(struct request_queue *q);
 699 extern void blk_sync_queue(struct request_queue *q);
 700 extern void __blk_stop_queue(struct request_queue *q);
 701 extern void __blk_run_queue(struct request_queue *q);
 702 extern void blk_run_queue(struct request_queue *);
 703 extern void blk_run_queue_async(struct request_queue *q);
 704 extern int blk_rq_map_user(struct request_queue *, struct request *,
 705                            struct rq_map_data *, void __user *, unsigned long,
 706                            gfp_t);
 707 extern int blk_rq_unmap_user(struct bio *);
 708 extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, unsigned int, gfp_t);
 709 extern int blk_rq_map_user_iov(struct request_queue *, struct request *,
 710                                struct rq_map_data *, struct sg_iovec *, int,
 711                                unsigned int, gfp_t);
 712 extern int blk_execute_rq(struct request_queue *, struct gendisk *,
 713                           struct request *, int);
 714 extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *,
 715                                   struct request *, int, rq_end_io_fn *);
 716
 717 static inline struct request_queue *bdev_get_queue(struct block_device *bdev)
 718 {
 719         return bdev->bd_disk->queue;
 720 }
 721
 722 /*
 723  * blk_rq_pos()                 : the current sector
 724  * blk_rq_bytes()               : bytes left in the entire request
 725  * blk_rq_cur_bytes()           : bytes left in the current segment
 726  * blk_rq_err_bytes()           : bytes left till the next error boundary
 727  * blk_rq_sectors()             : sectors left in the entire request
 728  * blk_rq_cur_sectors()         : sectors left in the current segment
 729  */
 730 static inline sector_t blk_rq_pos(const struct request *rq)
 731 {
 732         return rq->__sector;
 733 }
 734
 735 static inline unsigned int blk_rq_bytes(const struct request *rq)
 736 {
 737         return rq->__data_len;
 738 }
 739
 740 static inline int blk_rq_cur_bytes(const struct request *rq)
 741 {
 742         return rq->bio ? bio_cur_bytes(rq->bio) : 0;
 743 }
 744
 745 extern unsigned int blk_rq_err_bytes(const struct request *rq);
 746
 747 static inline unsigned int blk_rq_sectors(const struct request *rq)
 748 {
 749         return blk_rq_bytes(rq) >> 9;
 750 }
 751
 752 static inline unsigned int blk_rq_cur_sectors(const struct request *rq)
 753 {
 754         return blk_rq_cur_bytes(rq) >> 9;
 755 }
 756
 757 /*
 758  * Request issue related functions.
 759  */
 760 extern struct request *blk_peek_request(struct request_queue *q);
 761 extern void blk_start_request(struct request *rq);
 762 extern struct request *blk_fetch_request(struct request_queue *q);
 763
 764 /*
 765  * Request completion related functions.
 766  *
 767  * blk_update_request() completes given number of bytes and updates
 768  * the request without completing it.
 769  *
 770  * blk_end_request() and friends.  __blk_end_request() must be called
 771  * with the request queue spinlock acquired.
 772  *
 773  * Several drivers define their own end_request and call
 774  * blk_end_request() for parts of the original function.
 775  * This prevents code duplication in drivers.
 776  */
 777 extern bool blk_update_request(struct request *rq, int error,
 778                                unsigned int nr_bytes);
 779 extern bool blk_end_request(struct request *rq, int error,
 780                             unsigned int nr_bytes);
 781 extern void blk_end_request_all(struct request *rq, int error);
 782 extern bool blk_end_request_cur(struct request *rq, int error);
 783 extern bool blk_end_request_err(struct request *rq, int error);
 784 extern bool __blk_end_request(struct request *rq, int error,
 785                               unsigned int nr_bytes);
 786 extern void __blk_end_request_all(struct request *rq, int error);
 787 extern bool __blk_end_request_cur(struct request *rq, int error);
 788 extern bool __blk_end_request_err(struct request *rq, int error);
 789
 790 extern void blk_complete_request(struct request *);
 791 extern void __blk_complete_request(struct request *);
 792 extern void blk_abort_request(struct request *);
 793 extern void blk_abort_queue(struct request_queue *);
 794 extern void blk_unprep_request(struct request *);
 795
 796 /*
 797  * Access functions for manipulating queue properties
 798  */
 799 extern struct request_queue *blk_init_queue_node(request_fn_proc *rfn,
 800                                         spinlock_t *lock, int node_id);
 801 extern struct request_queue *blk_init_allocated_queue_node(struct request_queue *,
 802                                                            request_fn_proc *,
 803                                                            spinlock_t *, int node_id);
 804 extern struct request_queue *blk_init_queue(request_fn_proc *, spinlock_t *);
 805 extern struct request_queue *blk_init_allocated_queue(struct request_queue *,
 806                                                       request_fn_proc *, spinlock_t *);
 807 extern void blk_cleanup_queue(struct request_queue *);
 808 extern void blk_queue_make_request(struct request_queue *, make_request_fn *);
 809 extern void blk_queue_bounce_limit(struct request_queue *, u64);
 810 extern void blk_limits_max_hw_sectors(struct queue_limits *, unsigned int);
 811 extern void blk_queue_max_hw_sectors(struct request_queue *, unsigned int);
 812 extern void blk_queue_max_segments(struct request_queue *, unsigned short);
 813 extern void blk_queue_max_segment_size(struct request_queue *, unsigned int);
 814 extern void blk_queue_max_discard_sectors(struct request_queue *q,
 815                 unsigned int max_discard_sectors);
 816 extern void blk_queue_logical_block_size(struct request_queue *, unsigned short);
 817 extern void blk_queue_physical_block_size(struct request_queue *, unsigned int);
 818 extern void blk_queue_alignment_offset(struct request_queue *q,
 819                                        unsigned int alignment);
 820 extern void blk_limits_io_min(struct queue_limits *limits, unsigned int min);
 821 extern void blk_queue_io_min(struct request_queue *q, unsigned int min);
 822 extern void blk_limits_io_opt(struct queue_limits *limits, unsigned int opt);
 823 extern void blk_queue_io_opt(struct request_queue *q, unsigned int opt);
 824 extern void blk_set_default_limits(struct queue_limits *lim);
 825 extern int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
 826                             sector_t offset);
 827 extern int bdev_stack_limits(struct queue_limits *t, struct block_device *bdev,
 828                             sector_t offset);
 829 extern void disk_stack_limits(struct gendisk *disk, struct block_device *bdev,
 830                               sector_t offset);
 831 extern void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b);
 832 extern void blk_queue_dma_pad(struct request_queue *, unsigned int);
 833 extern void blk_queue_update_dma_pad(struct request_queue *, unsigned int);
 834 extern int blk_queue_dma_drain(struct request_queue *q,
 835                                dma_drain_needed_fn *dma_drain_needed,
 836                                void *buf, unsigned int size);
 837 extern void blk_queue_lld_busy(struct request_queue *q, lld_busy_fn *fn);
 838 extern void blk_queue_segment_boundary(struct request_queue *, unsigned long);
 839 extern void blk_queue_prep_rq(struct request_queue *, prep_rq_fn *pfn);
 840 extern void blk_queue_unprep_rq(struct request_queue *, unprep_rq_fn *ufn);
 841 extern void blk_queue_merge_bvec(struct request_queue *, merge_bvec_fn *);
 842 extern void blk_queue_dma_alignment(struct request_queue *, int);
 843 extern void blk_queue_update_dma_alignment(struct request_queue *, int);
 844 extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *);
 845 extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *);
 846 extern void blk_queue_rq_timeout(struct request_queue *, unsigned int);
 847 extern void blk_queue_flush(struct request_queue *q, unsigned int flush);
 848 extern void blk_queue_flush_queueable(struct request_queue *q, bool queueable);
 849 extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev);
 850
 851 extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *);
 852 extern void blk_dump_rq_flags(struct request *, char *);
 853 extern long nr_blockdev_pages(void);
 854
 855 int blk_get_queue(struct request_queue *);
 856 struct request_queue *blk_alloc_queue(gfp_t);
 857 struct request_queue *blk_alloc_queue_node(gfp_t, int);
 858 extern void blk_put_queue(struct request_queue *);
 859
 860 struct blk_plug {
 861         unsigned long magic;
 862         struct list_head list;
 863         struct list_head cb_list;
 864         unsigned int should_sort;
 865 };
 866 struct blk_plug_cb {
 867         struct list_head list;
 868         void (*callback)(struct blk_plug_cb *);
 869 };
 870
 871 extern void blk_start_plug(struct blk_plug *);
 872 extern void blk_finish_plug(struct blk_plug *);
 873 extern void blk_flush_plug_list(struct blk_plug *, bool);
 874
 875 static inline void blk_flush_plug(struct task_struct *tsk)
 876 {
 877         struct blk_plug *plug = tsk->plug;
 878
 879         if (plug)
 880                 blk_flush_plug_list(plug, false);
 881 }
 882
 883 static inline void blk_schedule_flush_plug(struct task_struct *tsk)
 884 {
 885         struct blk_plug *plug = tsk->plug;
 886
 887         if (plug)
 888                 blk_flush_plug_list(plug, true);
 889 }
 890
 891 static inline bool blk_needs_flush_plug(struct task_struct *tsk)
 892 {
 893         struct blk_plug *plug = tsk->plug;
 894
 895         return plug && (!list_empty(&plug->list) || !list_empty(&plug->cb_list));
 896 }
 897
 898 /*
 899  * tag stuff
 900  */
 901 #define blk_rq_tagged(rq)               ((rq)->cmd_flags & REQ_QUEUED)
 902 extern int blk_queue_start_tag(struct request_queue *, struct request *);
 903 extern struct request *blk_queue_find_tag(struct request_queue *, int);
 904 extern void blk_queue_end_tag(struct request_queue *, struct request *);
 905 extern int blk_queue_init_tags(struct request_queue *, int, struct blk_queue_tag *);
 906 extern void blk_queue_free_tags(struct request_queue *);
 907 extern int blk_queue_resize_tags(struct request_queue *, int);
 908 extern void blk_queue_invalidate_tags(struct request_queue *);
 909 extern struct blk_queue_tag *blk_init_tags(int);
 910 extern void blk_free_tags(struct blk_queue_tag *);
 911
 912 static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt,
 913                                                 int tag)
 914 {
 915         if (unlikely(bqt == NULL || tag >= bqt->real_max_depth))
 916                 return NULL;
 917         return bqt->tag_index[tag];
 918 }
 919
 920 #define BLKDEV_DISCARD_SECURE  0x01    /* secure discard */
 921
 922 extern int blkdev_issue_flush(struct block_device *, gfp_t, sector_t *);
 923 extern int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
 924                 sector_t nr_sects, gfp_t gfp_mask, unsigned long flags);
 925 extern int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
 926                         sector_t nr_sects, gfp_t gfp_mask);
 927 static inline int sb_issue_discard(struct super_block *sb, sector_t block,
 928                 sector_t nr_blocks, gfp_t gfp_mask, unsigned long flags)
 929 {
 930         return blkdev_issue_discard(sb->s_bdev, block << (sb->s_blocksize_bits - 9),
 931                                     nr_blocks << (sb->s_blocksize_bits - 9),
 932                                     gfp_mask, flags);
 933 }
 934 static inline int sb_issue_zeroout(struct super_block *sb, sector_t block,
 935                 sector_t nr_blocks, gfp_t gfp_mask)
 936 {
 937         return blkdev_issue_zeroout(sb->s_bdev,
 938                                     block << (sb->s_blocksize_bits - 9),
 939                                     nr_blocks << (sb->s_blocksize_bits - 9),
 940                                     gfp_mask);
 941 }
 942
 943 extern int blk_verify_command(unsigned char *cmd, fmode_t has_write_perm);
 944
 945 enum blk_default_limits {
 946         BLK_MAX_SEGMENTS        = 128,
 947         BLK_SAFE_MAX_SECTORS    = 255,
 948         BLK_DEF_MAX_SECTORS     = 1024,
 949         BLK_MAX_SEGMENT_SIZE    = 65536,
 950         BLK_SEG_BOUNDARY_MASK   = 0xFFFFFFFFUL,
 951 };
 952
 953 #define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist)
 954
 955 static inline unsigned long queue_bounce_pfn(struct request_queue *q)
 956 {
 957         return q->limits.bounce_pfn;
 958 }
 959
 960 static inline unsigned long queue_segment_boundary(struct request_queue *q)
 961 {
 962         return q->limits.seg_boundary_mask;
 963 }
 964
 965 static inline unsigned int queue_max_sectors(struct request_queue *q)
 966 {
 967         return q->limits.max_sectors;
 968 }
 969
 970 static inline unsigned int queue_max_hw_sectors(struct request_queue *q)
 971 {
 972         return q->limits.max_hw_sectors;
 973 }
 974
 975 static inline unsigned short queue_max_segments(struct request_queue *q)
 976 {
 977         return q->limits.max_segments;
 978 }
 979
 980 static inline unsigned int queue_max_segment_size(struct request_queue *q)
 981 {
 982         return q->limits.max_segment_size;
 983 }
 984
 985 static inline unsigned short queue_logical_block_size(struct request_queue *q)
 986 {
 987         int retval = 512;
 988
 989         if (q && q->limits.logical_block_size)
 990                 retval = q->limits.logical_block_size;
 991
 992         return retval;
 993 }
 994
 995 static inline unsigned short bdev_logical_block_size(struct block_device *bdev)
 996 {
 997         return queue_logical_block_size(bdev_get_queue(bdev));
 998 }
 999
1000 static inline unsigned int queue_physical_block_size(struct request_queue *q)
1001 {
1002         return q->limits.physical_block_size;
1003 }
1004
1005 static inline unsigned int bdev_physical_block_size(struct block_device *bdev)
1006 {
1007         return queue_physical_block_size(bdev_get_queue(bdev));
1008 }
1009
1010 static inline unsigned int queue_io_min(struct request_queue *q)
1011 {
1012         return q->limits.io_min;
1013 }
1014
1015 static inline int bdev_io_min(struct block_device *bdev)
1016 {
1017         return queue_io_min(bdev_get_queue(bdev));
1018 }
1019
1020 static inline unsigned int queue_io_opt(struct request_queue *q)
1021 {
1022         return q->limits.io_opt;
1023 }
1024
1025 static inline int bdev_io_opt(struct block_device *bdev)
1026 {
1027         return queue_io_opt(bdev_get_queue(bdev));
1028 }
1029
1030 static inline int queue_alignment_offset(struct request_queue *q)
1031 {
1032         if (q->limits.misaligned)
1033                 return -1;
1034
1035         return q->limits.alignment_offset;
1036 }
1037
1038 static inline int queue_limit_alignment_offset(struct queue_limits *lim, sector_t sector)
1039 {
1040         unsigned int granularity = max(lim->physical_block_size, lim->io_min);
1041         unsigned int alignment = (sector << 9) & (granularity - 1);
1042
1043         return (granularity + lim->alignment_offset - alignment)
1044                 & (granularity - 1);
1045 }
1046
1047 static inline int bdev_alignment_offset(struct block_device *bdev)
1048 {
1049         struct request_queue *q = bdev_get_queue(bdev);
1050
1051         if (q->limits.misaligned)
1052                 return -1;
1053
1054         if (bdev != bdev->bd_contains)
1055                 return bdev->bd_part->alignment_offset;
1056
1057         return q->limits.alignment_offset;
1058 }
1059
1060 static inline int queue_discard_alignment(struct request_queue *q)
1061 {
1062         if (q->limits.discard_misaligned)
1063                 return -1;
1064
1065         return q->limits.discard_alignment;
1066 }
1067
1068 static inline int queue_limit_discard_alignment(struct queue_limits *lim, sector_t sector)
1069 {
1070         unsigned int alignment = (sector << 9) & (lim->discard_granularity - 1);
1071
1072         if (!lim->max_discard_sectors)
1073                 return 0;
1074
1075         return (lim->discard_granularity + lim->discard_alignment - alignment)
1076                 & (lim->discard_granularity - 1);
1077 }
1078
1079 static inline unsigned int queue_discard_zeroes_data(struct request_queue *q)
1080 {
1081         if (q->limits.max_discard_sectors && q->limits.discard_zeroes_data == 1)
1082                 return 1;
1083
1084         return 0;
1085 }
1086
1087 static inline unsigned int bdev_discard_zeroes_data(struct block_device *bdev)
1088 {
1089         return queue_discard_zeroes_data(bdev_get_queue(bdev));
1090 }
1091
1092 static inline int queue_dma_alignment(struct request_queue *q)
1093 {
1094         return q ? q->dma_alignment : 511;
1095 }
1096
1097 static inline int blk_rq_aligned(struct request_queue *q, unsigned long addr,
1098                                  unsigned int len)
1099 {
1100         unsigned int alignment = queue_dma_alignment(q) | q->dma_pad_mask;
1101         return !(addr & alignment) && !(len & alignment);
1102 }
1103
1104 /* assumes size > 256 */
1105 static inline unsigned int blksize_bits(unsigned int size)
1106 {
1107         unsigned int bits = 8;
1108         do {
1109                 bits++;
1110                 size >>= 1;
1111         } while (size > 256);
1112         return bits;
1113 }
1114
1115 static inline unsigned int block_size(struct block_device *bdev)
1116 {
1117         return bdev->bd_block_size;
1118 }
1119
1120 static inline bool queue_flush_queueable(struct request_queue *q)
1121 {
1122         return !q->flush_not_queueable;
1123 }
1124
1125 typedef struct {struct page *v;} Sector;
1126
1127 unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *);
1128
1129 static inline void put_dev_sector(Sector p)
1130 {
1131         page_cache_release(p.v);
1132 }
1133
1134 struct work_struct;
1135 int kblockd_schedule_work(struct request_queue *q, struct work_struct *work);
1136
1137 #ifdef CONFIG_BLK_CGROUP
1138 /*
1139  * This should not be using sched_clock(). A real patch is in progress
1140  * to fix this up, until that is in place we need to disable preemption
1141  * around sched_clock() in this function and set_io_start_time_ns().
1142  */
1143 static inline void set_start_time_ns(struct request *req)
1144 {
1145         preempt_disable();
1146         req->start_time_ns = sched_clock();
1147         preempt_enable();
1148 }
1149
1150 static inline void set_io_start_time_ns(struct request *req)
1151 {
1152         preempt_disable();
1153         req->io_start_time_ns = sched_clock();
1154         preempt_enable();
1155 }
1156
1157 static inline uint64_t rq_start_time_ns(struct request *req)
1158 {
1159         return req->start_time_ns;
1160 }
1161
1162 static inline uint64_t rq_io_start_time_ns(struct request *req)
1163 {
1164         return req->io_start_time_ns;
1165 }
1166 #else
1167 static inline void set_start_time_ns(struct request *req) {}
1168 static inline void set_io_start_time_ns(struct request *req) {}
1169 static inline uint64_t rq_start_time_ns(struct request *req)
1170 {
1171         return 0;
1172 }
1173 static inline uint64_t rq_io_start_time_ns(struct request *req)
1174 {
1175         return 0;
1176 }
1177 #endif
1178
1179 #ifdef CONFIG_BLK_DEV_THROTTLING
1180 extern int blk_throtl_init(struct request_queue *q);
1181 extern void blk_throtl_exit(struct request_queue *q);
1182 extern int blk_throtl_bio(struct request_queue *q, struct bio **bio);
1183 #else /* CONFIG_BLK_DEV_THROTTLING */
1184 static inline int blk_throtl_bio(struct request_queue *q, struct bio **bio)
1185 {
1186         return 0;
1187 }
1188
1189 static inline int blk_throtl_init(struct request_queue *q) { return 0; }
1190 static inline int blk_throtl_exit(struct request_queue *q) { return 0; }
1191 #endif /* CONFIG_BLK_DEV_THROTTLING */
1192
1193 #define MODULE_ALIAS_BLOCKDEV(major,minor) \
1194         MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor))
1195 #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \
1196         MODULE_ALIAS("block-major-" __stringify(major) "-*")
1197
1198 #if defined(CONFIG_BLK_DEV_INTEGRITY)
1199
1200 #define INTEGRITY_FLAG_READ     2       /* verify data integrity on read */
1201 #define INTEGRITY_FLAG_WRITE    4       /* generate data integrity on write */
1202
1203 struct blk_integrity_exchg {
1204         void                    *prot_buf;
1205         void                    *data_buf;
1206         sector_t                sector;
1207         unsigned int            data_size;
1208         unsigned short          sector_size;
1209         const char              *disk_name;
1210 };
1211
1212 typedef void (integrity_gen_fn) (struct blk_integrity_exchg *);
1213 typedef int (integrity_vrfy_fn) (struct blk_integrity_exchg *);
1214 typedef void (integrity_set_tag_fn) (void *, void *, unsigned int);
1215 typedef void (integrity_get_tag_fn) (void *, void *, unsigned int);
1216
1217 struct blk_integrity {
1218         integrity_gen_fn        *generate_fn;
1219         integrity_vrfy_fn       *verify_fn;
1220         integrity_set_tag_fn    *set_tag_fn;
1221         integrity_get_tag_fn    *get_tag_fn;
1222
1223         unsigned short          flags;
1224         unsigned short          tuple_size;
1225         unsigned short          sector_size;
1226         unsigned short          tag_size;
1227
1228         const char              *name;
1229
1230         struct kobject          kobj;
1231 };
1232
1233 extern bool blk_integrity_is_initialized(struct gendisk *);
1234 extern int blk_integrity_register(struct gendisk *, struct blk_integrity *);
1235 extern void blk_integrity_unregister(struct gendisk *);
1236 extern int blk_integrity_compare(struct gendisk *, struct gendisk *);
1237 extern int blk_rq_map_integrity_sg(struct request_queue *, struct bio *,
1238                                    struct scatterlist *);
1239 extern int blk_rq_count_integrity_sg(struct request_queue *, struct bio *);
1240 extern int blk_integrity_merge_rq(struct request_queue *, struct request *,
1241                                   struct request *);
1242 extern int blk_integrity_merge_bio(struct request_queue *, struct request *,
1243                                    struct bio *);
1244
1245 static inline
1246 struct blk_integrity *bdev_get_integrity(struct block_device *bdev)
1247 {
1248         return bdev->bd_disk->integrity;
1249 }
1250
1251 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk)
1252 {
1253         return disk->integrity;
1254 }
1255
1256 static inline int blk_integrity_rq(struct request *rq)
1257 {
1258         if (rq->bio == NULL)
1259                 return 0;
1260
1261         return bio_integrity(rq->bio);
1262 }
1263
1264 static inline void blk_queue_max_integrity_segments(struct request_queue *q,
1265                                                     unsigned int segs)
1266 {
1267         q->limits.max_integrity_segments = segs;
1268 }
1269
1270 static inline unsigned short
1271 queue_max_integrity_segments(struct request_queue *q)
1272 {
1273         return q->limits.max_integrity_segments;
1274 }
1275
1276 #else /* CONFIG_BLK_DEV_INTEGRITY */
1277
1278 #define blk_integrity_rq(rq)                    (0)
1279 #define blk_rq_count_integrity_sg(a, b)         (0)
1280 #define blk_rq_map_integrity_sg(a, b, c)        (0)
1281 #define bdev_get_integrity(a)                   (0)
1282 #define blk_get_integrity(a)                    (0)
1283 #define blk_integrity_compare(a, b)             (0)
1284 #define blk_integrity_register(a, b)            (0)
1285 #define blk_integrity_unregister(a)             do { } while (0);
1286 #define blk_queue_max_integrity_segments(a, b)  do { } while (0);
1287 #define queue_max_integrity_segments(a)         (0)
1288 #define blk_integrity_merge_rq(a, b, c)         (0)
1289 #define blk_integrity_merge_bio(a, b, c)        (0)
1290 #define blk_integrity_is_initialized(a)         (0)
1291
1292 #endif /* CONFIG_BLK_DEV_INTEGRITY */
1293
1294 struct block_device_operations {
1295         int (*open) (struct block_device *, fmode_t);
1296         int (*release) (struct gendisk *, fmode_t);
1297         int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1298         int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1299         int (*direct_access) (struct block_device *, sector_t,
1300                                                 void **, unsigned long *);
1301         unsigned int (*check_events) (struct gendisk *disk,
1302                                       unsigned int clearing);
1303         /* ->media_changed() is DEPRECATED, use ->check_events() instead */
1304         int (*media_changed) (struct gendisk *);
1305         void (*unlock_native_capacity) (struct gendisk *);
1306         int (*revalidate_disk) (struct gendisk *);
1307         int (*getgeo)(struct block_device *, struct hd_geometry *);
1308         /* this callback is with swap_lock and sometimes page table lock held */
1309         void (*swap_slot_free_notify) (struct block_device *, unsigned long);
1310         struct module *owner;
1311 };
1312
1313 extern int __blkdev_driver_ioctl(struct block_device *, fmode_t, unsigned int,
1314                                  unsigned long);
1315 #else /* CONFIG_BLOCK */
1316 /*
1317  * stubs for when the block layer is configured out
1318  */
1319 #define buffer_heads_over_limit 0
1320
1321 static inline long nr_blockdev_pages(void)
1322 {
1323         return 0;
1324 }
1325
1326 struct blk_plug {
1327 };
1328
1329 static inline void blk_start_plug(struct blk_plug *plug)
1330 {
1331 }
1332
1333 static inline void blk_finish_plug(struct blk_plug *plug)
1334 {
1335 }
1336
1337 static inline void blk_flush_plug(struct task_struct *task)
1338 {
1339 }
1340
1341 static inline void blk_schedule_flush_plug(struct task_struct *task)
1342 {
1343 }
1344
1345
1346 static inline bool blk_needs_flush_plug(struct task_struct *tsk)
1347 {
1348         return false;
1349 }
1350
1351 #endif /* CONFIG_BLOCK */
1352
1353 #endif