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/stringify.h>
  18 #include <linux/gfp.h>
  19 #include <linux/bsg.h>
  20 #include <linux/smp.h>
  21
  22 #include <asm/scatterlist.h>
  23
  24 struct module;
  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 struct bsg_job;
  34
  35 #define BLKDEV_MIN_RQ   4
  36 #define BLKDEV_MAX_RQ   128     /* Default maximum */
  37
  38 struct request;
  39 typedef void (rq_end_io_fn)(struct request *, int);
  40
  41 struct request_list {
  42         /*
  43          * count[], starved[], and wait[] are indexed by
  44          * BLK_RW_SYNC/BLK_RW_ASYNC
  45          */
  46         int count[2];
  47         int starved[2];
  48         int elvpriv;
  49         mempool_t *rq_pool;
  50         wait_queue_head_t wait[2];
  51 };
  52
  53 /*
  54  * request command types
  55  */
  56 enum rq_cmd_type_bits {
  57         REQ_TYPE_FS             = 1,    /* fs request */
  58         REQ_TYPE_BLOCK_PC,              /* scsi command */
  59         REQ_TYPE_SENSE,                 /* sense request */
  60         REQ_TYPE_PM_SUSPEND,            /* suspend request */
  61         REQ_TYPE_PM_RESUME,             /* resume request */
  62         REQ_TYPE_PM_SHUTDOWN,           /* shutdown request */
  63         REQ_TYPE_SPECIAL,               /* driver defined type */
  64         /*
  65          * for ATA/ATAPI devices. this really doesn't belong here, ide should
  66          * use REQ_TYPE_SPECIAL and use rq->cmd[0] with the range of driver
  67          * private REQ_LB opcodes to differentiate what type of request this is
  68          */
  69         REQ_TYPE_ATA_TASKFILE,
  70         REQ_TYPE_ATA_PC,
  71 };
  72
  73 #define BLK_MAX_CDB     16
  74
  75 /*
  76  * try to put the fields that are referenced together in the same cacheline.
  77  * if you modify this structure, be sure to check block/blk-core.c:blk_rq_init()
  78  * as well!
  79  */
  80 struct request {
  81         struct list_head queuelist;
  82         struct call_single_data csd;
  83
  84         struct request_queue *q;
  85
  86         unsigned int cmd_flags;
  87         enum rq_cmd_type_bits cmd_type;
  88         unsigned long atomic_flags;
  89
  90         int cpu;
  91
  92         /* the following two fields are internal, NEVER access directly */
  93         unsigned int __data_len;        /* total data len */
  94         sector_t __sector;              /* sector cursor */
  95
  96         struct bio *bio;
  97         struct bio *biotail;
  98
  99         struct hlist_node hash; /* merge hash */
 100         /*
 101          * The rb_node is only used inside the io scheduler, requests
 102          * are pruned when moved to the dispatch queue. So let the
 103          * completion_data share space with the rb_node.
 104          */
 105         union {
 106                 struct rb_node rb_node; /* sort/lookup */
 107                 void *completion_data;
 108         };
 109
 110         /*
 111          * Three pointers are available for the IO schedulers, if they need
 112          * more they have to dynamically allocate it.  Flush requests are
 113          * never put on the IO scheduler. So let the flush fields share
 114          * space with the elevator data.
 115          */
 116         union {
 117                 struct {
 118                         struct io_cq            *icq;
 119                         void                    *priv[2];
 120                 } elv;
 121
 122                 struct {
 123                         unsigned int            seq;
 124                         struct list_head        list;
 125                         rq_end_io_fn            *saved_end_io;
 126                 } flush;
 127         };
 128
 129         struct gendisk *rq_disk;
 130         struct hd_struct *part;
 131         unsigned long start_time;
 132 #ifdef CONFIG_BLK_CGROUP
 133         unsigned long long start_time_ns;
 134         unsigned long long io_start_time_ns;    /* when passed to hardware */
 135 #endif
 136         /* Number of scatter-gather DMA addr+len pairs after
 137          * physical address coalescing is performed.
 138          */
 139         unsigned short nr_phys_segments;
 140 #if defined(CONFIG_BLK_DEV_INTEGRITY)
 141         unsigned short nr_integrity_segments;
 142 #endif
 143
 144         unsigned short ioprio;
 145
 146         int ref_count;
 147
 148         void *special;          /* opaque pointer available for LLD use */
 149         char *buffer;           /* kaddr of the current segment if available */
 150
 151         int tag;
 152         int errors;
 153
 154         /*
 155          * when request is used as a packet command carrier
 156          */
 157         unsigned char __cmd[BLK_MAX_CDB];
 158         unsigned char *cmd;
 159         unsigned short cmd_len;
 160
 161         unsigned int extra_len; /* length of alignment and padding */
 162         unsigned int sense_len;
 163         unsigned int resid_len; /* residual count */
 164         void *sense;
 165
 166         unsigned long deadline;
 167         struct list_head timeout_list;
 168         unsigned int timeout;
 169         int retries;
 170
 171         /*
 172          * completion callback.
 173          */
 174         rq_end_io_fn *end_io;
 175         void *end_io_data;
 176
 177         /* for bidi */
 178         struct request *next_rq;
 179 };
 180
 181 static inline unsigned short req_get_ioprio(struct request *req)
 182 {
 183         return req->ioprio;
 184 }
 185
 186 /*
 187  * State information carried for REQ_TYPE_PM_SUSPEND and REQ_TYPE_PM_RESUME
 188  * requests. Some step values could eventually be made generic.
 189  */
 190 struct request_pm_state
 191 {
 192         /* PM state machine step value, currently driver specific */
 193         int     pm_step;
 194         /* requested PM state value (S1, S2, S3, S4, ...) */
 195         u32     pm_state;
 196         void*   data;           /* for driver use */
 197 };
 198
 199 #include <linux/elevator.h>
 200
 201 typedef void (request_fn_proc) (struct request_queue *q);
 202 typedef void (make_request_fn) (struct request_queue *q, struct bio *bio);
 203 typedef int (prep_rq_fn) (struct request_queue *, struct request *);
 204 typedef void (unprep_rq_fn) (struct request_queue *, struct request *);
 205
 206 struct bio_vec;
 207 struct bvec_merge_data {
 208         struct block_device *bi_bdev;
 209         sector_t bi_sector;
 210         unsigned bi_size;
 211         unsigned long bi_rw;
 212 };
 213 typedef int (merge_bvec_fn) (struct request_queue *, struct bvec_merge_data *,
 214                              struct bio_vec *);
 215 typedef void (softirq_done_fn)(struct request *);
 216 typedef int (dma_drain_needed_fn)(struct request *);
 217 typedef int (lld_busy_fn) (struct request_queue *q);
 218 typedef int (bsg_job_fn) (struct bsg_job *);
 219
 220 enum blk_eh_timer_return {
 221         BLK_EH_NOT_HANDLED,
 222         BLK_EH_HANDLED,
 223         BLK_EH_RESET_TIMER,
 224 };
 225
 226 typedef enum blk_eh_timer_return (rq_timed_out_fn)(struct request *);
 227
 228 enum blk_queue_state {
 229         Queue_down,
 230         Queue_up,
 231 };
 232
 233 struct blk_queue_tag {
 234         struct request **tag_index;     /* map of busy tags */
 235         unsigned long *tag_map;         /* bit map of free/busy tags */
 236         int busy;                       /* current depth */
 237         int max_depth;                  /* what we will send to device */
 238         int real_max_depth;             /* what the array can hold */
 239         atomic_t refcnt;                /* map can be shared */
 240 };
 241
 242 #define BLK_SCSI_MAX_CMDS       (256)
 243 #define BLK_SCSI_CMD_PER_LONG   (BLK_SCSI_MAX_CMDS / (sizeof(long) * 8))
 244
 245 struct queue_limits {
 246         unsigned long           bounce_pfn;
 247         unsigned long           seg_boundary_mask;
 248
 249         unsigned int            max_hw_sectors;
 250         unsigned int            max_sectors;
 251         unsigned int            max_segment_size;
 252         unsigned int            physical_block_size;
 253         unsigned int            alignment_offset;
 254         unsigned int            io_min;
 255         unsigned int            io_opt;
 256         unsigned int            max_discard_sectors;
 257         unsigned int            discard_granularity;
 258         unsigned int            discard_alignment;
 259
 260         unsigned short          logical_block_size;
 261         unsigned short          max_segments;
 262         unsigned short          max_integrity_segments;
 263
 264         unsigned char           misaligned;
 265         unsigned char           discard_misaligned;
 266         unsigned char           cluster;
 267         unsigned char           discard_zeroes_data;
 268 };
 269
 270 struct request_queue {
 271         /*
 272          * Together with queue_head for cacheline sharing
 273          */
 274         struct list_head        queue_head;
 275         struct request          *last_merge;
 276         struct elevator_queue   *elevator;
 277
 278         /*
 279          * the queue request freelist, one for reads and one for writes
 280          */
 281         struct request_list     rq;
 282
 283         request_fn_proc         *request_fn;
 284         make_request_fn         *make_request_fn;
 285         prep_rq_fn              *prep_rq_fn;
 286         unprep_rq_fn            *unprep_rq_fn;
 287         merge_bvec_fn           *merge_bvec_fn;
 288         softirq_done_fn         *softirq_done_fn;
 289         rq_timed_out_fn         *rq_timed_out_fn;
 290         dma_drain_needed_fn     *dma_drain_needed;
 291         lld_busy_fn             *lld_busy_fn;
 292
 293         /*
 294          * Dispatch queue sorting
 295          */
 296         sector_t                end_sector;
 297         struct request          *boundary_rq;
 298
 299         /*
 300          * Delayed queue handling
 301          */
 302         struct delayed_work     delay_work;
 303
 304         struct backing_dev_info backing_dev_info;
 305
 306         /*
 307          * The queue owner gets to use this for whatever they like.
 308          * ll_rw_blk doesn't touch it.
 309          */
 310         void                    *queuedata;
 311
 312         /*
 313          * various queue flags, see QUEUE_* below
 314          */
 315         unsigned long           queue_flags;
 316
 317         /*
 318          * ida allocated id for this queue.  Used to index queues from
 319          * ioctx.
 320          */
 321         int                     id;
 322
 323         /*
 324          * queue needs bounce pages for pages above this limit
 325          */
 326         gfp_t                   bounce_gfp;
 327
 328         /*
 329          * protects queue structures from reentrancy. ->__queue_lock should
 330          * _never_ be used directly, it is queue private. always use
 331          * ->queue_lock.
 332          */
 333         spinlock_t              __queue_lock;
 334         spinlock_t              *queue_lock;
 335
 336         /*
 337          * queue kobject
 338          */
 339         struct kobject kobj;
 340
 341         /*
 342          * queue settings
 343          */
 344         unsigned long           nr_requests;    /* Max # of requests */
 345         unsigned int            nr_congestion_on;
 346         unsigned int            nr_congestion_off;
 347         unsigned int            nr_batching;
 348
 349         unsigned int            dma_drain_size;
 350         void                    *dma_drain_buffer;
 351         unsigned int            dma_pad_mask;
 352         unsigned int            dma_alignment;
 353
 354         struct blk_queue_tag    *queue_tags;
 355         struct list_head        tag_busy_list;
 356
 357         unsigned int            nr_sorted;
 358         unsigned int            in_flight[2];
 359
 360         unsigned int            rq_timeout;
 361         struct timer_list       timeout;
 362         struct list_head        timeout_list;
 363
 364         struct list_head        icq_list;
 365
 366         struct queue_limits     limits;
 367
 368         /*
 369          * sg stuff
 370          */
 371         unsigned int            sg_timeout;
 372         unsigned int            sg_reserved_size;
 373         int                     node;
 374 #ifdef CONFIG_BLK_DEV_IO_TRACE
 375         struct blk_trace        *blk_trace;
 376 #endif
 377         /*
 378          * for flush operations
 379          */
 380         unsigned int            flush_flags;
 381         unsigned int            flush_not_queueable:1;
 382         unsigned int            flush_queue_delayed:1;
 383         unsigned int            flush_pending_idx:1;
 384         unsigned int            flush_running_idx:1;
 385         unsigned long           flush_pending_since;
 386         struct list_head        flush_queue[2];
 387         struct list_head        flush_data_in_flight;
 388         struct request          flush_rq;
 389
 390         struct mutex            sysfs_lock;
 391
 392 #if defined(CONFIG_BLK_DEV_BSG)
 393         bsg_job_fn              *bsg_job_fn;
 394         int                     bsg_job_size;
 395         struct bsg_class_device bsg_dev;
 396 #endif
 397
 398 #ifdef CONFIG_BLK_DEV_THROTTLING
 399         /* Throttle data */
 400         struct throtl_data *td;
 401 #endif
 402 };
 403
 404 #define QUEUE_FLAG_QUEUED       1       /* uses generic tag queueing */
 405 #define QUEUE_FLAG_STOPPED      2       /* queue is stopped */
 406 #define QUEUE_FLAG_SYNCFULL     3       /* read queue has been filled */
 407 #define QUEUE_FLAG_ASYNCFULL    4       /* write queue has been filled */
 408 #define QUEUE_FLAG_DEAD         5       /* queue being torn down */
 409 #define QUEUE_FLAG_ELVSWITCH    6       /* don't use elevator, just do FIFO */
 410 #define QUEUE_FLAG_BIDI         7       /* queue supports bidi requests */
 411 #define QUEUE_FLAG_NOMERGES     8       /* disable merge attempts */
 412 #define QUEUE_FLAG_SAME_COMP    9       /* complete on same CPU-group */
 413 #define QUEUE_FLAG_FAIL_IO     10       /* fake timeout */
 414 #define QUEUE_FLAG_STACKABLE   11       /* supports request stacking */
 415 #define QUEUE_FLAG_NONROT      12       /* non-rotational device (SSD) */
 416 #define QUEUE_FLAG_VIRT        QUEUE_FLAG_NONROT /* paravirt device */
 417 #define QUEUE_FLAG_IO_STAT     13       /* do IO stats */
 418 #define QUEUE_FLAG_DISCARD     14       /* supports DISCARD */
 419 #define QUEUE_FLAG_NOXMERGES   15       /* No extended merges */
 420 #define QUEUE_FLAG_ADD_RANDOM  16       /* Contributes to random pool */
 421 #define QUEUE_FLAG_SECDISCARD  17       /* supports SECDISCARD */
 422 #define QUEUE_FLAG_SAME_FORCE  18       /* force complete on same CPU */
 423
 424 #define QUEUE_FLAG_DEFAULT      ((1 << QUEUE_FLAG_IO_STAT) |            \
 425                                  (1 << QUEUE_FLAG_STACKABLE)    |       \
 426                                  (1 << QUEUE_FLAG_SAME_COMP)    |       \
 427                                  (1 << QUEUE_FLAG_ADD_RANDOM))
 428
 429 static inline void queue_lockdep_assert_held(struct request_queue *q)
 430 {
 431         if (q->queue_lock)
 432                 lockdep_assert_held(q->queue_lock);
 433 }
 434
 435 static inline void queue_flag_set_unlocked(unsigned int flag,
 436                                            struct request_queue *q)
 437 {
 438         __set_bit(flag, &q->queue_flags);
 439 }
 440
 441 static inline int queue_flag_test_and_clear(unsigned int flag,
 442                                             struct request_queue *q)
 443 {
 444         queue_lockdep_assert_held(q);
 445
 446         if (test_bit(flag, &q->queue_flags)) {
 447                 __clear_bit(flag, &q->queue_flags);
 448                 return 1;
 449         }
 450
 451         return 0;
 452 }
 453
 454 static inline int queue_flag_test_and_set(unsigned int flag,
 455                                           struct request_queue *q)
 456 {
 457         queue_lockdep_assert_held(q);
 458
 459         if (!test_bit(flag, &q->queue_flags)) {
 460                 __set_bit(flag, &q->queue_flags);
 461                 return 0;
 462         }
 463
 464         return 1;
 465 }
 466
 467 static inline void queue_flag_set(unsigned int flag, struct request_queue *q)
 468 {
 469         queue_lockdep_assert_held(q);
 470         __set_bit(flag, &q->queue_flags);
 471 }
 472
 473 static inline void queue_flag_clear_unlocked(unsigned int flag,
 474                                              struct request_queue *q)
 475 {
 476         __clear_bit(flag, &q->queue_flags);
 477 }
 478
 479 static inline int queue_in_flight(struct request_queue *q)
 480 {
 481         return q->in_flight[0] + q->in_flight[1];
 482 }
 483
 484 static inline void queue_flag_clear(unsigned int flag, struct request_queue *q)
 485 {
 486         queue_lockdep_assert_held(q);
 487         __clear_bit(flag, &q->queue_flags);
 488 }
 489
 490 #define blk_queue_tagged(q)     test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags)
 491 #define blk_queue_stopped(q)    test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
 492 #define blk_queue_dead(q)       test_bit(QUEUE_FLAG_DEAD, &(q)->queue_flags)
 493 #define blk_queue_nomerges(q)   test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags)
 494 #define blk_queue_noxmerges(q)  \
 495         test_bit(QUEUE_FLAG_NOXMERGES, &(q)->queue_flags)
 496 #define blk_queue_nonrot(q)     test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags)
 497 #define blk_queue_io_stat(q)    test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags)
 498 #define blk_queue_add_random(q) test_bit(QUEUE_FLAG_ADD_RANDOM, &(q)->queue_flags)
 499 #define blk_queue_stackable(q)  \
 500         test_bit(QUEUE_FLAG_STACKABLE, &(q)->queue_flags)
 501 #define blk_queue_discard(q)    test_bit(QUEUE_FLAG_DISCARD, &(q)->queue_flags)
 502 #define blk_queue_secdiscard(q) (blk_queue_discard(q) && \
 503         test_bit(QUEUE_FLAG_SECDISCARD, &(q)->queue_flags))
 504
 505 #define blk_noretry_request(rq) \
 506         ((rq)->cmd_flags & (REQ_FAILFAST_DEV|REQ_FAILFAST_TRANSPORT| \
 507                              REQ_FAILFAST_DRIVER))
 508
 509 #define blk_account_rq(rq) \
 510         (((rq)->cmd_flags & REQ_STARTED) && \
 511          ((rq)->cmd_type == REQ_TYPE_FS || \
 512           ((rq)->cmd_flags & REQ_DISCARD)))
 513
 514 #define blk_pm_request(rq)      \
 515         ((rq)->cmd_type == REQ_TYPE_PM_SUSPEND || \
 516          (rq)->cmd_type == REQ_TYPE_PM_RESUME)
 517
 518 #define blk_rq_cpu_valid(rq)    ((rq)->cpu != -1)
 519 #define blk_bidi_rq(rq)         ((rq)->next_rq != NULL)
 520 /* rq->queuelist of dequeued request must be list_empty() */
 521 #define blk_queued_rq(rq)       (!list_empty(&(rq)->queuelist))
 522
 523 #define list_entry_rq(ptr)      list_entry((ptr), struct request, queuelist)
 524
 525 #define rq_data_dir(rq)         ((rq)->cmd_flags & 1)
 526
 527 static inline unsigned int blk_queue_cluster(struct request_queue *q)
 528 {
 529         return q->limits.cluster;
 530 }
 531
 532 /*
 533  * We regard a request as sync, if either a read or a sync write
 534  */
 535 static inline bool rw_is_sync(unsigned int rw_flags)
 536 {
 537         return !(rw_flags & REQ_WRITE) || (rw_flags & REQ_SYNC);
 538 }
 539
 540 static inline bool rq_is_sync(struct request *rq)
 541 {
 542         return rw_is_sync(rq->cmd_flags);
 543 }
 544
 545 static inline int blk_queue_full(struct request_queue *q, int sync)
 546 {
 547         if (sync)
 548                 return test_bit(QUEUE_FLAG_SYNCFULL, &q->queue_flags);
 549         return test_bit(QUEUE_FLAG_ASYNCFULL, &q->queue_flags);
 550 }
 551
 552 static inline void blk_set_queue_full(struct request_queue *q, int sync)
 553 {
 554         if (sync)
 555                 queue_flag_set(QUEUE_FLAG_SYNCFULL, q);
 556         else
 557                 queue_flag_set(QUEUE_FLAG_ASYNCFULL, q);
 558 }
 559
 560 static inline void blk_clear_queue_full(struct request_queue *q, int sync)
 561 {
 562         if (sync)
 563                 queue_flag_clear(QUEUE_FLAG_SYNCFULL, q);
 564         else
 565                 queue_flag_clear(QUEUE_FLAG_ASYNCFULL, q);
 566 }
 567
 568
 569 /*
 570  * mergeable request must not have _NOMERGE or _BARRIER bit set, nor may
 571  * it already be started by driver.
 572  */
 573 #define RQ_NOMERGE_FLAGS        \
 574         (REQ_NOMERGE | REQ_STARTED | REQ_SOFTBARRIER | REQ_FLUSH | REQ_FUA)
 575 #define rq_mergeable(rq)        \
 576         (!((rq)->cmd_flags & RQ_NOMERGE_FLAGS) && \
 577          (((rq)->cmd_flags & REQ_DISCARD) || \
 578           (rq)->cmd_type == REQ_TYPE_FS))
 579
 580 /*
 581  * q->prep_rq_fn return values
 582  */
 583 #define BLKPREP_OK              0       /* serve it */
 584 #define BLKPREP_KILL            1       /* fatal error, kill */
 585 #define BLKPREP_DEFER           2       /* leave on queue */
 586
 587 extern unsigned long blk_max_low_pfn, blk_max_pfn;
 588
 589 /*
 590  * standard bounce addresses:
 591  *
 592  * BLK_BOUNCE_HIGH      : bounce all highmem pages
 593  * BLK_BOUNCE_ANY       : don't bounce anything
 594  * BLK_BOUNCE_ISA       : bounce pages above ISA DMA boundary
 595  */
 596
 597 #if BITS_PER_LONG == 32
 598 #define BLK_BOUNCE_HIGH         ((u64)blk_max_low_pfn << PAGE_SHIFT)
 599 #else
 600 #define BLK_BOUNCE_HIGH         -1ULL
 601 #endif
 602 #define BLK_BOUNCE_ANY          (-1ULL)
 603 #define BLK_BOUNCE_ISA          (DMA_BIT_MASK(24))
 604
 605 /*
 606  * default timeout for SG_IO if none specified
 607  */
 608 #define BLK_DEFAULT_SG_TIMEOUT  (60 * HZ)
 609 #define BLK_MIN_SG_TIMEOUT      (7 * HZ)
 610
 611 #ifdef CONFIG_BOUNCE
 612 extern int init_emergency_isa_pool(void);
 613 extern void blk_queue_bounce(struct request_queue *q, struct bio **bio);
 614 #else
 615 static inline int init_emergency_isa_pool(void)
 616 {
 617         return 0;
 618 }
 619 static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio)
 620 {
 621 }
 622 #endif /* CONFIG_MMU */
 623
 624 struct rq_map_data {
 625         struct page **pages;
 626         int page_order;
 627         int nr_entries;
 628         unsigned long offset;
 629         int null_mapped;
 630         int from_user;
 631 };
 632
 633 struct req_iterator {
 634         int i;
 635         struct bio *bio;
 636 };
 637
 638 /* This should not be used directly - use rq_for_each_segment */
 639 #define for_each_bio(_bio)              \
 640         for (; _bio; _bio = _bio->bi_next)
 641 #define __rq_for_each_bio(_bio, rq)     \
 642         if ((rq->bio))                  \
 643                 for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next)
 644
 645 #define rq_for_each_segment(bvl, _rq, _iter)                    \
 646         __rq_for_each_bio(_iter.bio, _rq)                       \
 647                 bio_for_each_segment(bvl, _iter.bio, _iter.i)
 648
 649 #define rq_iter_last(rq, _iter)                                 \
 650                 (_iter.bio->bi_next == NULL && _iter.i == _iter.bio->bi_vcnt-1)
 651
 652 #ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
 653 # error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform"
 654 #endif
 655 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
 656 extern void rq_flush_dcache_pages(struct request *rq);
 657 #else
 658 static inline void rq_flush_dcache_pages(struct request *rq)
 659 {
 660 }
 661 #endif
 662
 663 extern int blk_register_queue(struct gendisk *disk);
 664 extern void blk_unregister_queue(struct gendisk *disk);
 665 extern void generic_make_request(struct bio *bio);
 666 extern void blk_rq_init(struct request_queue *q, struct request *rq);
 667 extern void blk_put_request(struct request *);
 668 extern void __blk_put_request(struct request_queue *, struct request *);
 669 extern struct request *blk_get_request(struct request_queue *, int, gfp_t);
 670 extern struct request *blk_make_request(struct request_queue *, struct bio *,
 671                                         gfp_t);
 672 extern void blk_requeue_request(struct request_queue *, struct request *);
 673 extern void blk_add_request_payload(struct request *rq, struct page *page,
 674                 unsigned int len);
 675 extern int blk_rq_check_limits(struct request_queue *q, struct request *rq);
 676 extern int blk_lld_busy(struct request_queue *q);
 677 extern int blk_rq_prep_clone(struct request *rq, struct request *rq_src,
 678                              struct bio_set *bs, gfp_t gfp_mask,
 679                              int (*bio_ctr)(struct bio *, struct bio *, void *),
 680                              void *data);
 681 extern void blk_rq_unprep_clone(struct request *rq);
 682 extern int blk_insert_cloned_request(struct request_queue *q,
 683                                      struct request *rq);
 684 extern void blk_delay_queue(struct request_queue *, unsigned long);
 685 extern void blk_recount_segments(struct request_queue *, struct bio *);
 686 extern int scsi_verify_blk_ioctl(struct block_device *, unsigned int);
 687 extern int scsi_cmd_blk_ioctl(struct block_device *, fmode_t,
 688                               unsigned int, void __user *);
 689 extern int scsi_cmd_ioctl(struct request_queue *, struct gendisk *, fmode_t,
 690                           unsigned int, void __user *);
 691 extern int sg_scsi_ioctl(struct request_queue *, struct gendisk *, fmode_t,
 692                          struct scsi_ioctl_command __user *);
 693
 694 extern void blk_queue_bio(struct request_queue *q, struct bio *bio);
 695
 696 /*
 697  * A queue has just exitted congestion.  Note this in the global counter of
 698  * congested queues, and wake up anyone who was waiting for requests to be
 699  * put back.
 700  */
 701 static inline void blk_clear_queue_congested(struct request_queue *q, int sync)
 702 {
 703         clear_bdi_congested(&q->backing_dev_info, sync);
 704 }
 705
 706 /*
 707  * A queue has just entered congestion.  Flag that in the queue's VM-visible
 708  * state flags and increment the global gounter of congested queues.
 709  */
 710 static inline void blk_set_queue_congested(struct request_queue *q, int sync)
 711 {
 712         set_bdi_congested(&q->backing_dev_info, sync);
 713 }
 714
 715 extern void blk_start_queue(struct request_queue *q);
 716 extern void blk_stop_queue(struct request_queue *q);
 717 extern void blk_sync_queue(struct request_queue *q);
 718 extern void __blk_stop_queue(struct request_queue *q);
 719 extern void __blk_run_queue(struct request_queue *q);
 720 extern void blk_run_queue(struct request_queue *);
 721 extern void blk_run_queue_async(struct request_queue *q);
 722 extern int blk_rq_map_user(struct request_queue *, struct request *,
 723                            struct rq_map_data *, void __user *, unsigned long,
 724                            gfp_t);
 725 extern int blk_rq_unmap_user(struct bio *);
 726 extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, unsigned int, gfp_t);
 727 extern int blk_rq_map_user_iov(struct request_queue *, struct request *,
 728                                struct rq_map_data *, struct sg_iovec *, int,
 729                                unsigned int, gfp_t);
 730 extern int blk_execute_rq(struct request_queue *, struct gendisk *,
 731                           struct request *, int);
 732 extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *,
 733                                   struct request *, int, rq_end_io_fn *);
 734
 735 static inline struct request_queue *bdev_get_queue(struct block_device *bdev)
 736 {
 737         return bdev->bd_disk->queue;
 738 }
 739
 740 /*
 741  * blk_rq_pos()                 : the current sector
 742  * blk_rq_bytes()               : bytes left in the entire request
 743  * blk_rq_cur_bytes()           : bytes left in the current segment
 744  * blk_rq_err_bytes()           : bytes left till the next error boundary
 745  * blk_rq_sectors()             : sectors left in the entire request
 746  * blk_rq_cur_sectors()         : sectors left in the current segment
 747  */
 748 static inline sector_t blk_rq_pos(const struct request *rq)
 749 {
 750         return rq->__sector;
 751 }
 752
 753 static inline unsigned int blk_rq_bytes(const struct request *rq)
 754 {
 755         return rq->__data_len;
 756 }
 757
 758 static inline int blk_rq_cur_bytes(const struct request *rq)
 759 {
 760         return rq->bio ? bio_cur_bytes(rq->bio) : 0;
 761 }
 762
 763 extern unsigned int blk_rq_err_bytes(const struct request *rq);
 764
 765 static inline unsigned int blk_rq_sectors(const struct request *rq)
 766 {
 767         return blk_rq_bytes(rq) >> 9;
 768 }
 769
 770 static inline unsigned int blk_rq_cur_sectors(const struct request *rq)
 771 {
 772         return blk_rq_cur_bytes(rq) >> 9;
 773 }
 774
 775 /*
 776  * Request issue related functions.
 777  */
 778 extern struct request *blk_peek_request(struct request_queue *q);
 779 extern void blk_start_request(struct request *rq);
 780 extern struct request *blk_fetch_request(struct request_queue *q);
 781
 782 /*
 783  * Request completion related functions.
 784  *
 785  * blk_update_request() completes given number of bytes and updates
 786  * the request without completing it.
 787  *
 788  * blk_end_request() and friends.  __blk_end_request() must be called
 789  * with the request queue spinlock acquired.
 790  *
 791  * Several drivers define their own end_request and call
 792  * blk_end_request() for parts of the original function.
 793  * This prevents code duplication in drivers.
 794  */
 795 extern bool blk_update_request(struct request *rq, int error,
 796                                unsigned int nr_bytes);
 797 extern bool blk_end_request(struct request *rq, int error,
 798                             unsigned int nr_bytes);
 799 extern void blk_end_request_all(struct request *rq, int error);
 800 extern bool blk_end_request_cur(struct request *rq, int error);
 801 extern bool blk_end_request_err(struct request *rq, int error);
 802 extern bool __blk_end_request(struct request *rq, int error,
 803                               unsigned int nr_bytes);
 804 extern void __blk_end_request_all(struct request *rq, int error);
 805 extern bool __blk_end_request_cur(struct request *rq, int error);
 806 extern bool __blk_end_request_err(struct request *rq, int error);
 807
 808 extern void blk_complete_request(struct request *);
 809 extern void __blk_complete_request(struct request *);
 810 extern void blk_abort_request(struct request *);
 811 extern void blk_abort_queue(struct request_queue *);
 812 extern void blk_unprep_request(struct request *);
 813
 814 /*
 815  * Access functions for manipulating queue properties
 816  */
 817 extern struct request_queue *blk_init_queue_node(request_fn_proc *rfn,
 818                                         spinlock_t *lock, int node_id);
 819 extern struct request_queue *blk_init_queue(request_fn_proc *, spinlock_t *);
 820 extern struct request_queue *blk_init_allocated_queue(struct request_queue *,
 821                                                       request_fn_proc *, spinlock_t *);
 822 extern void blk_cleanup_queue(struct request_queue *);
 823 extern void blk_queue_make_request(struct request_queue *, make_request_fn *);
 824 extern void blk_queue_bounce_limit(struct request_queue *, u64);
 825 extern void blk_limits_max_hw_sectors(struct queue_limits *, unsigned int);
 826 extern void blk_queue_max_hw_sectors(struct request_queue *, unsigned int);
 827 extern void blk_queue_max_segments(struct request_queue *, unsigned short);
 828 extern void blk_queue_max_segment_size(struct request_queue *, unsigned int);
 829 extern void blk_queue_max_discard_sectors(struct request_queue *q,
 830                 unsigned int max_discard_sectors);
 831 extern void blk_queue_logical_block_size(struct request_queue *, unsigned short);
 832 extern void blk_queue_physical_block_size(struct request_queue *, unsigned int);
 833 extern void blk_queue_alignment_offset(struct request_queue *q,
 834                                        unsigned int alignment);
 835 extern void blk_limits_io_min(struct queue_limits *limits, unsigned int min);
 836 extern void blk_queue_io_min(struct request_queue *q, unsigned int min);
 837 extern void blk_limits_io_opt(struct queue_limits *limits, unsigned int opt);
 838 extern void blk_queue_io_opt(struct request_queue *q, unsigned int opt);
 839 extern void blk_set_default_limits(struct queue_limits *lim);
 840 extern void blk_set_stacking_limits(struct queue_limits *lim);
 841 extern int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
 842                             sector_t offset);
 843 extern int bdev_stack_limits(struct queue_limits *t, struct block_device *bdev,
 844                             sector_t offset);
 845 extern void disk_stack_limits(struct gendisk *disk, struct block_device *bdev,
 846                               sector_t offset);
 847 extern void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b);
 848 extern void blk_queue_dma_pad(struct request_queue *, unsigned int);
 849 extern void blk_queue_update_dma_pad(struct request_queue *, unsigned int);
 850 extern int blk_queue_dma_drain(struct request_queue *q,
 851                                dma_drain_needed_fn *dma_drain_needed,
 852                                void *buf, unsigned int size);
 853 extern void blk_queue_lld_busy(struct request_queue *q, lld_busy_fn *fn);
 854 extern void blk_queue_segment_boundary(struct request_queue *, unsigned long);
 855 extern void blk_queue_prep_rq(struct request_queue *, prep_rq_fn *pfn);
 856 extern void blk_queue_unprep_rq(struct request_queue *, unprep_rq_fn *ufn);
 857 extern void blk_queue_merge_bvec(struct request_queue *, merge_bvec_fn *);
 858 extern void blk_queue_dma_alignment(struct request_queue *, int);
 859 extern void blk_queue_update_dma_alignment(struct request_queue *, int);
 860 extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *);
 861 extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *);
 862 extern void blk_queue_rq_timeout(struct request_queue *, unsigned int);
 863 extern void blk_queue_flush(struct request_queue *q, unsigned int flush);
 864 extern void blk_queue_flush_queueable(struct request_queue *q, bool queueable);
 865 extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev);
 866
 867 extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *);
 868 extern void blk_dump_rq_flags(struct request *, char *);
 869 extern long nr_blockdev_pages(void);
 870
 871 bool __must_check blk_get_queue(struct request_queue *);
 872 struct request_queue *blk_alloc_queue(gfp_t);
 873 struct request_queue *blk_alloc_queue_node(gfp_t, int);
 874 extern void blk_put_queue(struct request_queue *);
 875
 876 /*
 877  * blk_plug permits building a queue of related requests by holding the I/O
 878  * fragments for a short period. This allows merging of sequential requests
 879  * into single larger request. As the requests are moved from a per-task list to
 880  * the device's request_queue in a batch, this results in improved scalability
 881  * as the lock contention for request_queue lock is reduced.
 882  *
 883  * It is ok not to disable preemption when adding the request to the plug list
 884  * or when attempting a merge, because blk_schedule_flush_list() will only flush
 885  * the plug list when the task sleeps by itself. For details, please see
 886  * schedule() where blk_schedule_flush_plug() is called.
 887  */
 888 struct blk_plug {
 889         unsigned long magic; /* detect uninitialized use-cases */
 890         struct list_head list; /* requests */
 891         struct list_head cb_list; /* md requires an unplug callback */
 892         unsigned int should_sort; /* list to be sorted before flushing? */
 893 };
 894 #define BLK_MAX_REQUEST_COUNT 16
 895
 896 struct blk_plug_cb {
 897         struct list_head list;
 898         void (*callback)(struct blk_plug_cb *);
 899 };
 900
 901 extern void blk_start_plug(struct blk_plug *);
 902 extern void blk_finish_plug(struct blk_plug *);
 903 extern void blk_flush_plug_list(struct blk_plug *, bool);
 904
 905 static inline void blk_flush_plug(struct task_struct *tsk)
 906 {
 907         struct blk_plug *plug = tsk->plug;
 908
 909         if (plug)
 910                 blk_flush_plug_list(plug, false);
 911 }
 912
 913 static inline void blk_schedule_flush_plug(struct task_struct *tsk)
 914 {
 915         struct blk_plug *plug = tsk->plug;
 916
 917         if (plug)
 918                 blk_flush_plug_list(plug, true);
 919 }
 920
 921 static inline bool blk_needs_flush_plug(struct task_struct *tsk)
 922 {
 923         struct blk_plug *plug = tsk->plug;
 924
 925         return plug && (!list_empty(&plug->list) || !list_empty(&plug->cb_list));
 926 }
 927
 928 /*
 929  * tag stuff
 930  */
 931 #define blk_rq_tagged(rq)               ((rq)->cmd_flags & REQ_QUEUED)
 932 extern int blk_queue_start_tag(struct request_queue *, struct request *);
 933 extern struct request *blk_queue_find_tag(struct request_queue *, int);
 934 extern void blk_queue_end_tag(struct request_queue *, struct request *);
 935 extern int blk_queue_init_tags(struct request_queue *, int, struct blk_queue_tag *);
 936 extern void blk_queue_free_tags(struct request_queue *);
 937 extern int blk_queue_resize_tags(struct request_queue *, int);
 938 extern void blk_queue_invalidate_tags(struct request_queue *);
 939 extern struct blk_queue_tag *blk_init_tags(int);
 940 extern void blk_free_tags(struct blk_queue_tag *);
 941
 942 static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt,
 943                                                 int tag)
 944 {
 945         if (unlikely(bqt == NULL || tag >= bqt->real_max_depth))
 946                 return NULL;
 947         return bqt->tag_index[tag];
 948 }
 949
 950 #define BLKDEV_DISCARD_SECURE  0x01    /* secure discard */
 951
 952 extern int blkdev_issue_flush(struct block_device *, gfp_t, sector_t *);
 953 extern int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
 954                 sector_t nr_sects, gfp_t gfp_mask, unsigned long flags);
 955 extern int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
 956                         sector_t nr_sects, gfp_t gfp_mask);
 957 static inline int sb_issue_discard(struct super_block *sb, sector_t block,
 958                 sector_t nr_blocks, gfp_t gfp_mask, unsigned long flags)
 959 {
 960         return blkdev_issue_discard(sb->s_bdev, block << (sb->s_blocksize_bits - 9),
 961                                     nr_blocks << (sb->s_blocksize_bits - 9),
 962                                     gfp_mask, flags);
 963 }
 964 static inline int sb_issue_zeroout(struct super_block *sb, sector_t block,
 965                 sector_t nr_blocks, gfp_t gfp_mask)
 966 {
 967         return blkdev_issue_zeroout(sb->s_bdev,
 968                                     block << (sb->s_blocksize_bits - 9),
 969                                     nr_blocks << (sb->s_blocksize_bits - 9),
 970                                     gfp_mask);
 971 }
 972
 973 extern int blk_verify_command(unsigned char *cmd, fmode_t has_write_perm);
 974
 975 enum blk_default_limits {
 976         BLK_MAX_SEGMENTS        = 128,
 977         BLK_SAFE_MAX_SECTORS    = 255,
 978         BLK_DEF_MAX_SECTORS     = 1024,
 979         BLK_MAX_SEGMENT_SIZE    = 65536,
 980         BLK_SEG_BOUNDARY_MASK   = 0xFFFFFFFFUL,
 981 };
 982
 983 #define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist)
 984
 985 static inline unsigned long queue_bounce_pfn(struct request_queue *q)
 986 {
 987         return q->limits.bounce_pfn;
 988 }
 989
 990 static inline unsigned long queue_segment_boundary(struct request_queue *q)
 991 {
 992         return q->limits.seg_boundary_mask;
 993 }
 994
 995 static inline unsigned int queue_max_sectors(struct request_queue *q)
 996 {
 997         return q->limits.max_sectors;
 998 }
 999
1000 static inline unsigned int queue_max_hw_sectors(struct request_queue *q)
1001 {
1002         return q->limits.max_hw_sectors;
1003 }
1004
1005 static inline unsigned short queue_max_segments(struct request_queue *q)
1006 {
1007         return q->limits.max_segments;
1008 }
1009
1010 static inline unsigned int queue_max_segment_size(struct request_queue *q)
1011 {
1012         return q->limits.max_segment_size;
1013 }
1014
1015 static inline unsigned short queue_logical_block_size(struct request_queue *q)
1016 {
1017         int retval = 512;
1018
1019         if (q && q->limits.logical_block_size)
1020                 retval = q->limits.logical_block_size;
1021
1022         return retval;
1023 }
1024
1025 static inline unsigned short bdev_logical_block_size(struct block_device *bdev)
1026 {
1027         return queue_logical_block_size(bdev_get_queue(bdev));
1028 }
1029
1030 static inline unsigned int queue_physical_block_size(struct request_queue *q)
1031 {
1032         return q->limits.physical_block_size;
1033 }
1034
1035 static inline unsigned int bdev_physical_block_size(struct block_device *bdev)
1036 {
1037         return queue_physical_block_size(bdev_get_queue(bdev));
1038 }
1039
1040 static inline unsigned int queue_io_min(struct request_queue *q)
1041 {
1042         return q->limits.io_min;
1043 }
1044
1045 static inline int bdev_io_min(struct block_device *bdev)
1046 {
1047         return queue_io_min(bdev_get_queue(bdev));
1048 }
1049
1050 static inline unsigned int queue_io_opt(struct request_queue *q)
1051 {
1052         return q->limits.io_opt;
1053 }
1054
1055 static inline int bdev_io_opt(struct block_device *bdev)
1056 {
1057         return queue_io_opt(bdev_get_queue(bdev));
1058 }
1059
1060 static inline int queue_alignment_offset(struct request_queue *q)
1061 {
1062         if (q->limits.misaligned)
1063                 return -1;
1064
1065         return q->limits.alignment_offset;
1066 }
1067
1068 static inline int queue_limit_alignment_offset(struct queue_limits *lim, sector_t sector)
1069 {
1070         unsigned int granularity = max(lim->physical_block_size, lim->io_min);
1071         unsigned int alignment = (sector << 9) & (granularity - 1);
1072
1073         return (granularity + lim->alignment_offset - alignment)
1074                 & (granularity - 1);
1075 }
1076
1077 static inline int bdev_alignment_offset(struct block_device *bdev)
1078 {
1079         struct request_queue *q = bdev_get_queue(bdev);
1080
1081         if (q->limits.misaligned)
1082                 return -1;
1083
1084         if (bdev != bdev->bd_contains)
1085                 return bdev->bd_part->alignment_offset;
1086
1087         return q->limits.alignment_offset;
1088 }
1089
1090 static inline int queue_discard_alignment(struct request_queue *q)
1091 {
1092         if (q->limits.discard_misaligned)
1093                 return -1;
1094
1095         return q->limits.discard_alignment;
1096 }
1097
1098 static inline int queue_limit_discard_alignment(struct queue_limits *lim, sector_t sector)
1099 {
1100         unsigned int alignment = (sector << 9) & (lim->discard_granularity - 1);
1101
1102         if (!lim->max_discard_sectors)
1103                 return 0;
1104
1105         return (lim->discard_granularity + lim->discard_alignment - alignment)
1106                 & (lim->discard_granularity - 1);
1107 }
1108
1109 static inline unsigned int queue_discard_zeroes_data(struct request_queue *q)
1110 {
1111         if (q->limits.max_discard_sectors && q->limits.discard_zeroes_data == 1)
1112                 return 1;
1113
1114         return 0;
1115 }
1116
1117 static inline unsigned int bdev_discard_zeroes_data(struct block_device *bdev)
1118 {
1119         return queue_discard_zeroes_data(bdev_get_queue(bdev));
1120 }
1121
1122 static inline int queue_dma_alignment(struct request_queue *q)
1123 {
1124         return q ? q->dma_alignment : 511;
1125 }
1126
1127 static inline int blk_rq_aligned(struct request_queue *q, unsigned long addr,
1128                                  unsigned int len)
1129 {
1130         unsigned int alignment = queue_dma_alignment(q) | q->dma_pad_mask;
1131         return !(addr & alignment) && !(len & alignment);
1132 }
1133
1134 /* assumes size > 256 */
1135 static inline unsigned int blksize_bits(unsigned int size)
1136 {
1137         unsigned int bits = 8;
1138         do {
1139                 bits++;
1140                 size >>= 1;
1141         } while (size > 256);
1142         return bits;
1143 }
1144
1145 static inline unsigned int block_size(struct block_device *bdev)
1146 {
1147         return bdev->bd_block_size;
1148 }
1149
1150 static inline bool queue_flush_queueable(struct request_queue *q)
1151 {
1152         return !q->flush_not_queueable;
1153 }
1154
1155 typedef struct {struct page *v;} Sector;
1156
1157 unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *);
1158
1159 static inline void put_dev_sector(Sector p)
1160 {
1161         page_cache_release(p.v);
1162 }
1163
1164 struct work_struct;
1165 int kblockd_schedule_work(struct request_queue *q, struct work_struct *work);
1166
1167 #ifdef CONFIG_BLK_CGROUP
1168 /*
1169  * This should not be using sched_clock(). A real patch is in progress
1170  * to fix this up, until that is in place we need to disable preemption
1171  * around sched_clock() in this function and set_io_start_time_ns().
1172  */
1173 static inline void set_start_time_ns(struct request *req)
1174 {
1175         preempt_disable();
1176         req->start_time_ns = sched_clock();
1177         preempt_enable();
1178 }
1179
1180 static inline void set_io_start_time_ns(struct request *req)
1181 {
1182         preempt_disable();
1183         req->io_start_time_ns = sched_clock();
1184         preempt_enable();
1185 }
1186
1187 static inline uint64_t rq_start_time_ns(struct request *req)
1188 {
1189         return req->start_time_ns;
1190 }
1191
1192 static inline uint64_t rq_io_start_time_ns(struct request *req)
1193 {
1194         return req->io_start_time_ns;
1195 }
1196 #else
1197 static inline void set_start_time_ns(struct request *req) {}
1198 static inline void set_io_start_time_ns(struct request *req) {}
1199 static inline uint64_t rq_start_time_ns(struct request *req)
1200 {
1201         return 0;
1202 }
1203 static inline uint64_t rq_io_start_time_ns(struct request *req)
1204 {
1205         return 0;
1206 }
1207 #endif
1208
1209 #define MODULE_ALIAS_BLOCKDEV(major,minor) \
1210         MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor))
1211 #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \
1212         MODULE_ALIAS("block-major-" __stringify(major) "-*")
1213
1214 #if defined(CONFIG_BLK_DEV_INTEGRITY)
1215
1216 #define INTEGRITY_FLAG_READ     2       /* verify data integrity on read */
1217 #define INTEGRITY_FLAG_WRITE    4       /* generate data integrity on write */
1218
1219 struct blk_integrity_exchg {
1220         void                    *prot_buf;
1221         void                    *data_buf;
1222         sector_t                sector;
1223         unsigned int            data_size;
1224         unsigned short          sector_size;
1225         const char              *disk_name;
1226 };
1227
1228 typedef void (integrity_gen_fn) (struct blk_integrity_exchg *);
1229 typedef int (integrity_vrfy_fn) (struct blk_integrity_exchg *);
1230 typedef void (integrity_set_tag_fn) (void *, void *, unsigned int);
1231 typedef void (integrity_get_tag_fn) (void *, void *, unsigned int);
1232
1233 struct blk_integrity {
1234         integrity_gen_fn        *generate_fn;
1235         integrity_vrfy_fn       *verify_fn;
1236         integrity_set_tag_fn    *set_tag_fn;
1237         integrity_get_tag_fn    *get_tag_fn;
1238
1239         unsigned short          flags;
1240         unsigned short          tuple_size;
1241         unsigned short          sector_size;
1242         unsigned short          tag_size;
1243
1244         const char              *name;
1245
1246         struct kobject          kobj;
1247 };
1248
1249 extern bool blk_integrity_is_initialized(struct gendisk *);
1250 extern int blk_integrity_register(struct gendisk *, struct blk_integrity *);
1251 extern void blk_integrity_unregister(struct gendisk *);
1252 extern int blk_integrity_compare(struct gendisk *, struct gendisk *);
1253 extern int blk_rq_map_integrity_sg(struct request_queue *, struct bio *,
1254                                    struct scatterlist *);
1255 extern int blk_rq_count_integrity_sg(struct request_queue *, struct bio *);
1256 extern int blk_integrity_merge_rq(struct request_queue *, struct request *,
1257                                   struct request *);
1258 extern int blk_integrity_merge_bio(struct request_queue *, struct request *,
1259                                    struct bio *);
1260
1261 static inline
1262 struct blk_integrity *bdev_get_integrity(struct block_device *bdev)
1263 {
1264         return bdev->bd_disk->integrity;
1265 }
1266
1267 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk)
1268 {
1269         return disk->integrity;
1270 }
1271
1272 static inline int blk_integrity_rq(struct request *rq)
1273 {
1274         if (rq->bio == NULL)
1275                 return 0;
1276
1277         return bio_integrity(rq->bio);
1278 }
1279
1280 static inline void blk_queue_max_integrity_segments(struct request_queue *q,
1281                                                     unsigned int segs)
1282 {
1283         q->limits.max_integrity_segments = segs;
1284 }
1285
1286 static inline unsigned short
1287 queue_max_integrity_segments(struct request_queue *q)
1288 {
1289         return q->limits.max_integrity_segments;
1290 }
1291
1292 #else /* CONFIG_BLK_DEV_INTEGRITY */
1293
1294 struct bio;
1295 struct block_device;
1296 struct gendisk;
1297 struct blk_integrity;
1298
1299 static inline int blk_integrity_rq(struct request *rq)
1300 {
1301         return 0;
1302 }
1303 static inline int blk_rq_count_integrity_sg(struct request_queue *q,
1304                                             struct bio *b)
1305 {
1306         return 0;
1307 }
1308 static inline int blk_rq_map_integrity_sg(struct request_queue *q,
1309                                           struct bio *b,
1310                                           struct scatterlist *s)
1311 {
1312         return 0;
1313 }
1314 static inline struct blk_integrity *bdev_get_integrity(struct block_device *b)
1315 {
1316         return 0;
1317 }
1318 static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk)
1319 {
1320         return NULL;
1321 }
1322 static inline int blk_integrity_compare(struct gendisk *a, struct gendisk *b)
1323 {
1324         return 0;
1325 }
1326 static inline int blk_integrity_register(struct gendisk *d,
1327                                          struct blk_integrity *b)
1328 {
1329         return 0;
1330 }
1331 static inline void blk_integrity_unregister(struct gendisk *d)
1332 {
1333 }
1334 static inline void blk_queue_max_integrity_segments(struct request_queue *q,
1335                                                     unsigned int segs)
1336 {
1337 }
1338 static inline unsigned short queue_max_integrity_segments(struct request_queue *q)
1339 {
1340         return 0;
1341 }
1342 static inline int blk_integrity_merge_rq(struct request_queue *rq,
1343                                          struct request *r1,
1344                                          struct request *r2)
1345 {
1346         return 0;
1347 }
1348 static inline int blk_integrity_merge_bio(struct request_queue *rq,
1349                                           struct request *r,
1350                                           struct bio *b)
1351 {
1352         return 0;
1353 }
1354 static inline bool blk_integrity_is_initialized(struct gendisk *g)
1355 {
1356         return 0;
1357 }
1358
1359 #endif /* CONFIG_BLK_DEV_INTEGRITY */
1360
1361 struct block_device_operations {
1362         int (*open) (struct block_device *, fmode_t);
1363         int (*release) (struct gendisk *, fmode_t);
1364         int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1365         int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1366         int (*direct_access) (struct block_device *, sector_t,
1367                                                 void **, unsigned long *);
1368         unsigned int (*check_events) (struct gendisk *disk,
1369                                       unsigned int clearing);
1370         /* ->media_changed() is DEPRECATED, use ->check_events() instead */
1371         int (*media_changed) (struct gendisk *);
1372         void (*unlock_native_capacity) (struct gendisk *);
1373         int (*revalidate_disk) (struct gendisk *);
1374         int (*getgeo)(struct block_device *, struct hd_geometry *);
1375         /* this callback is with swap_lock and sometimes page table lock held */
1376         void (*swap_slot_free_notify) (struct block_device *, unsigned long);
1377         struct module *owner;
1378 };
1379
1380 extern int __blkdev_driver_ioctl(struct block_device *, fmode_t, unsigned int,
1381                                  unsigned long);
1382 #else /* CONFIG_BLOCK */
1383 /*
1384  * stubs for when the block layer is configured out
1385  */
1386 #define buffer_heads_over_limit 0
1387
1388 static inline long nr_blockdev_pages(void)
1389 {
1390         return 0;
1391 }
1392
1393 struct blk_plug {
1394 };
1395
1396 static inline void blk_start_plug(struct blk_plug *plug)
1397 {
1398 }
1399
1400 static inline void blk_finish_plug(struct blk_plug *plug)
1401 {
1402 }
1403
1404 static inline void blk_flush_plug(struct task_struct *task)
1405 {
1406 }
1407
1408 static inline void blk_schedule_flush_plug(struct task_struct *task)
1409 {
1410 }
1411
1412
1413 static inline bool blk_needs_flush_plug(struct task_struct *tsk)
1414 {
1415         return false;
1416 }
1417
1418 #endif /* CONFIG_BLOCK */
1419
1420 #endif