linux/include/linux/genhd.h
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   1#ifndef _LINUX_GENHD_H
   2#define _LINUX_GENHD_H
   3
   4/*
   5 *      genhd.h Copyright (C) 1992 Drew Eckhardt
   6 *      Generic hard disk header file by  
   7 *              Drew Eckhardt
   8 *
   9 *              <drew@colorado.edu>
  10 */
  11
  12#include <linux/types.h>
  13#include <linux/kdev_t.h>
  14#include <linux/rcupdate.h>
  15#include <linux/slab.h>
  16
  17#ifdef CONFIG_BLOCK
  18
  19#define dev_to_disk(device)     container_of((device), struct gendisk, part0.__dev)
  20#define dev_to_part(device)     container_of((device), struct hd_struct, __dev)
  21#define disk_to_dev(disk)       (&(disk)->part0.__dev)
  22#define part_to_dev(part)       (&((part)->__dev))
  23
  24extern struct device_type part_type;
  25extern struct kobject *block_depr;
  26extern struct class block_class;
  27
  28enum {
  29/* These three have identical behaviour; use the second one if DOS FDISK gets
  30   confused about extended/logical partitions starting past cylinder 1023. */
  31        DOS_EXTENDED_PARTITION = 5,
  32        LINUX_EXTENDED_PARTITION = 0x85,
  33        WIN98_EXTENDED_PARTITION = 0x0f,
  34
  35        SUN_WHOLE_DISK = DOS_EXTENDED_PARTITION,
  36
  37        LINUX_SWAP_PARTITION = 0x82,
  38        LINUX_DATA_PARTITION = 0x83,
  39        LINUX_LVM_PARTITION = 0x8e,
  40        LINUX_RAID_PARTITION = 0xfd,    /* autodetect RAID partition */
  41
  42        SOLARIS_X86_PARTITION = LINUX_SWAP_PARTITION,
  43        NEW_SOLARIS_X86_PARTITION = 0xbf,
  44
  45        DM6_AUX1PARTITION = 0x51,       /* no DDO:  use xlated geom */
  46        DM6_AUX3PARTITION = 0x53,       /* no DDO:  use xlated geom */
  47        DM6_PARTITION = 0x54,           /* has DDO: use xlated geom & offset */
  48        EZD_PARTITION = 0x55,           /* EZ-DRIVE */
  49
  50        FREEBSD_PARTITION = 0xa5,       /* FreeBSD Partition ID */
  51        OPENBSD_PARTITION = 0xa6,       /* OpenBSD Partition ID */
  52        NETBSD_PARTITION = 0xa9,        /* NetBSD Partition ID */
  53        BSDI_PARTITION = 0xb7,          /* BSDI Partition ID */
  54        MINIX_PARTITION = 0x81,         /* Minix Partition ID */
  55        UNIXWARE_PARTITION = 0x63,      /* Same as GNU_HURD and SCO Unix */
  56};
  57
  58#define DISK_MAX_PARTS                  256
  59#define DISK_NAME_LEN                   32
  60
  61#include <linux/major.h>
  62#include <linux/device.h>
  63#include <linux/smp.h>
  64#include <linux/string.h>
  65#include <linux/fs.h>
  66#include <linux/workqueue.h>
  67
  68struct partition {
  69        unsigned char boot_ind;         /* 0x80 - active */
  70        unsigned char head;             /* starting head */
  71        unsigned char sector;           /* starting sector */
  72        unsigned char cyl;              /* starting cylinder */
  73        unsigned char sys_ind;          /* What partition type */
  74        unsigned char end_head;         /* end head */
  75        unsigned char end_sector;       /* end sector */
  76        unsigned char end_cyl;          /* end cylinder */
  77        __le32 start_sect;      /* starting sector counting from 0 */
  78        __le32 nr_sects;                /* nr of sectors in partition */
  79} __attribute__((packed));
  80
  81struct disk_stats {
  82        unsigned long sectors[2];       /* READs and WRITEs */
  83        unsigned long ios[2];
  84        unsigned long merges[2];
  85        unsigned long ticks[2];
  86        unsigned long io_ticks;
  87        unsigned long time_in_queue;
  88};
  89
  90#define PARTITION_META_INFO_VOLNAMELTH  64
  91/*
  92 * Enough for the string representation of any kind of UUID plus NULL.
  93 * EFI UUID is 36 characters. MSDOS UUID is 11 characters.
  94 */
  95#define PARTITION_META_INFO_UUIDLTH     37
  96
  97struct partition_meta_info {
  98        char uuid[PARTITION_META_INFO_UUIDLTH];
  99        u8 volname[PARTITION_META_INFO_VOLNAMELTH];
 100};
 101
 102struct hd_struct {
 103        sector_t start_sect;
 104        /*
 105         * nr_sects is protected by sequence counter. One might extend a
 106         * partition while IO is happening to it and update of nr_sects
 107         * can be non-atomic on 32bit machines with 64bit sector_t.
 108         */
 109        sector_t nr_sects;
 110        seqcount_t nr_sects_seq;
 111        sector_t alignment_offset;
 112        unsigned int discard_alignment;
 113        struct device __dev;
 114        struct kobject *holder_dir;
 115        int policy, partno;
 116        struct partition_meta_info *info;
 117#ifdef CONFIG_FAIL_MAKE_REQUEST
 118        int make_it_fail;
 119#endif
 120        unsigned long stamp;
 121        atomic_t in_flight[2];
 122#ifdef  CONFIG_SMP
 123        struct disk_stats __percpu *dkstats;
 124#else
 125        struct disk_stats dkstats;
 126#endif
 127        atomic_t ref;
 128        struct rcu_head rcu_head;
 129};
 130
 131#define GENHD_FL_REMOVABLE                      1
 132/* 2 is unused */
 133#define GENHD_FL_MEDIA_CHANGE_NOTIFY            4
 134#define GENHD_FL_CD                             8
 135#define GENHD_FL_UP                             16
 136#define GENHD_FL_SUPPRESS_PARTITION_INFO        32
 137#define GENHD_FL_EXT_DEVT                       64 /* allow extended devt */
 138#define GENHD_FL_NATIVE_CAPACITY                128
 139#define GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE     256
 140#define GENHD_FL_NO_PART_SCAN                   512
 141
 142enum {
 143        DISK_EVENT_MEDIA_CHANGE                 = 1 << 0, /* media changed */
 144        DISK_EVENT_EJECT_REQUEST                = 1 << 1, /* eject requested */
 145};
 146
 147#define BLK_SCSI_MAX_CMDS       (256)
 148#define BLK_SCSI_CMD_PER_LONG   (BLK_SCSI_MAX_CMDS / (sizeof(long) * 8))
 149
 150struct blk_scsi_cmd_filter {
 151        unsigned long read_ok[BLK_SCSI_CMD_PER_LONG];
 152        unsigned long write_ok[BLK_SCSI_CMD_PER_LONG];
 153        struct kobject kobj;
 154};
 155
 156struct disk_part_tbl {
 157        struct rcu_head rcu_head;
 158        int len;
 159        struct hd_struct __rcu *last_lookup;
 160        struct hd_struct __rcu *part[];
 161};
 162
 163struct disk_events;
 164
 165struct gendisk {
 166        /* major, first_minor and minors are input parameters only,
 167         * don't use directly.  Use disk_devt() and disk_max_parts().
 168         */
 169        int major;                      /* major number of driver */
 170        int first_minor;
 171        int minors;                     /* maximum number of minors, =1 for
 172                                         * disks that can't be partitioned. */
 173
 174        char disk_name[DISK_NAME_LEN];  /* name of major driver */
 175        char *(*devnode)(struct gendisk *gd, umode_t *mode);
 176
 177        unsigned int events;            /* supported events */
 178        unsigned int async_events;      /* async events, subset of all */
 179
 180        /* Array of pointers to partitions indexed by partno.
 181         * Protected with matching bdev lock but stat and other
 182         * non-critical accesses use RCU.  Always access through
 183         * helpers.
 184         */
 185        struct disk_part_tbl __rcu *part_tbl;
 186        struct hd_struct part0;
 187
 188        const struct block_device_operations *fops;
 189        struct request_queue *queue;
 190        void *private_data;
 191
 192        int flags;
 193        struct device *driverfs_dev;  // FIXME: remove
 194        struct kobject *slave_dir;
 195
 196        struct timer_rand_state *random;
 197        atomic_t sync_io;               /* RAID */
 198        struct disk_events *ev;
 199#ifdef  CONFIG_BLK_DEV_INTEGRITY
 200        struct blk_integrity *integrity;
 201#endif
 202        int node_id;
 203};
 204
 205static inline struct gendisk *part_to_disk(struct hd_struct *part)
 206{
 207        if (likely(part)) {
 208                if (part->partno)
 209                        return dev_to_disk(part_to_dev(part)->parent);
 210                else
 211                        return dev_to_disk(part_to_dev(part));
 212        }
 213        return NULL;
 214}
 215
 216static inline void part_pack_uuid(const u8 *uuid_str, u8 *to)
 217{
 218        int i;
 219        for (i = 0; i < 16; ++i) {
 220                *to++ = (hex_to_bin(*uuid_str) << 4) |
 221                        (hex_to_bin(*(uuid_str + 1)));
 222                uuid_str += 2;
 223                switch (i) {
 224                case 3:
 225                case 5:
 226                case 7:
 227                case 9:
 228                        uuid_str++;
 229                        continue;
 230                }
 231        }
 232}
 233
 234static inline int blk_part_pack_uuid(const u8 *uuid_str, u8 *to)
 235{
 236        part_pack_uuid(uuid_str, to);
 237        return 0;
 238}
 239
 240static inline int disk_max_parts(struct gendisk *disk)
 241{
 242        if (disk->flags & GENHD_FL_EXT_DEVT)
 243                return DISK_MAX_PARTS;
 244        return disk->minors;
 245}
 246
 247static inline bool disk_part_scan_enabled(struct gendisk *disk)
 248{
 249        return disk_max_parts(disk) > 1 &&
 250                !(disk->flags & GENHD_FL_NO_PART_SCAN);
 251}
 252
 253static inline dev_t disk_devt(struct gendisk *disk)
 254{
 255        return disk_to_dev(disk)->devt;
 256}
 257
 258static inline dev_t part_devt(struct hd_struct *part)
 259{
 260        return part_to_dev(part)->devt;
 261}
 262
 263extern struct hd_struct *disk_get_part(struct gendisk *disk, int partno);
 264
 265static inline void disk_put_part(struct hd_struct *part)
 266{
 267        if (likely(part))
 268                put_device(part_to_dev(part));
 269}
 270
 271/*
 272 * Smarter partition iterator without context limits.
 273 */
 274#define DISK_PITER_REVERSE      (1 << 0) /* iterate in the reverse direction */
 275#define DISK_PITER_INCL_EMPTY   (1 << 1) /* include 0-sized parts */
 276#define DISK_PITER_INCL_PART0   (1 << 2) /* include partition 0 */
 277#define DISK_PITER_INCL_EMPTY_PART0 (1 << 3) /* include empty partition 0 */
 278
 279struct disk_part_iter {
 280        struct gendisk          *disk;
 281        struct hd_struct        *part;
 282        int                     idx;
 283        unsigned int            flags;
 284};
 285
 286extern void disk_part_iter_init(struct disk_part_iter *piter,
 287                                 struct gendisk *disk, unsigned int flags);
 288extern struct hd_struct *disk_part_iter_next(struct disk_part_iter *piter);
 289extern void disk_part_iter_exit(struct disk_part_iter *piter);
 290
 291extern struct hd_struct *disk_map_sector_rcu(struct gendisk *disk,
 292                                             sector_t sector);
 293
 294/*
 295 * Macros to operate on percpu disk statistics:
 296 *
 297 * {disk|part|all}_stat_{add|sub|inc|dec}() modify the stat counters
 298 * and should be called between disk_stat_lock() and
 299 * disk_stat_unlock().
 300 *
 301 * part_stat_read() can be called at any time.
 302 *
 303 * part_stat_{add|set_all}() and {init|free}_part_stats are for
 304 * internal use only.
 305 */
 306#ifdef  CONFIG_SMP
 307#define part_stat_lock()        ({ rcu_read_lock(); get_cpu(); })
 308#define part_stat_unlock()      do { put_cpu(); rcu_read_unlock(); } while (0)
 309
 310#define __part_stat_add(cpu, part, field, addnd)                        \
 311        (per_cpu_ptr((part)->dkstats, (cpu))->field += (addnd))
 312
 313#define part_stat_read(part, field)                                     \
 314({                                                                      \
 315        typeof((part)->dkstats->field) res = 0;                         \
 316        unsigned int _cpu;                                              \
 317        for_each_possible_cpu(_cpu)                                     \
 318                res += per_cpu_ptr((part)->dkstats, _cpu)->field;       \
 319        res;                                                            \
 320})
 321
 322static inline void part_stat_set_all(struct hd_struct *part, int value)
 323{
 324        int i;
 325
 326        for_each_possible_cpu(i)
 327                memset(per_cpu_ptr(part->dkstats, i), value,
 328                                sizeof(struct disk_stats));
 329}
 330
 331static inline int init_part_stats(struct hd_struct *part)
 332{
 333        part->dkstats = alloc_percpu(struct disk_stats);
 334        if (!part->dkstats)
 335                return 0;
 336        return 1;
 337}
 338
 339static inline void free_part_stats(struct hd_struct *part)
 340{
 341        free_percpu(part->dkstats);
 342}
 343
 344#else /* !CONFIG_SMP */
 345#define part_stat_lock()        ({ rcu_read_lock(); 0; })
 346#define part_stat_unlock()      rcu_read_unlock()
 347
 348#define __part_stat_add(cpu, part, field, addnd)                                \
 349        ((part)->dkstats.field += addnd)
 350
 351#define part_stat_read(part, field)     ((part)->dkstats.field)
 352
 353static inline void part_stat_set_all(struct hd_struct *part, int value)
 354{
 355        memset(&part->dkstats, value, sizeof(struct disk_stats));
 356}
 357
 358static inline int init_part_stats(struct hd_struct *part)
 359{
 360        return 1;
 361}
 362
 363static inline void free_part_stats(struct hd_struct *part)
 364{
 365}
 366
 367#endif /* CONFIG_SMP */
 368
 369#define part_stat_add(cpu, part, field, addnd)  do {                    \
 370        __part_stat_add((cpu), (part), field, addnd);                   \
 371        if ((part)->partno)                                             \
 372                __part_stat_add((cpu), &part_to_disk((part))->part0,    \
 373                                field, addnd);                          \
 374} while (0)
 375
 376#define part_stat_dec(cpu, gendiskp, field)                             \
 377        part_stat_add(cpu, gendiskp, field, -1)
 378#define part_stat_inc(cpu, gendiskp, field)                             \
 379        part_stat_add(cpu, gendiskp, field, 1)
 380#define part_stat_sub(cpu, gendiskp, field, subnd)                      \
 381        part_stat_add(cpu, gendiskp, field, -subnd)
 382
 383static inline void part_inc_in_flight(struct hd_struct *part, int rw)
 384{
 385        atomic_inc(&part->in_flight[rw]);
 386        if (part->partno)
 387                atomic_inc(&part_to_disk(part)->part0.in_flight[rw]);
 388}
 389
 390static inline void part_dec_in_flight(struct hd_struct *part, int rw)
 391{
 392        atomic_dec(&part->in_flight[rw]);
 393        if (part->partno)
 394                atomic_dec(&part_to_disk(part)->part0.in_flight[rw]);
 395}
 396
 397static inline int part_in_flight(struct hd_struct *part)
 398{
 399        return atomic_read(&part->in_flight[0]) + atomic_read(&part->in_flight[1]);
 400}
 401
 402static inline struct partition_meta_info *alloc_part_info(struct gendisk *disk)
 403{
 404        if (disk)
 405                return kzalloc_node(sizeof(struct partition_meta_info),
 406                                    GFP_KERNEL, disk->node_id);
 407        return kzalloc(sizeof(struct partition_meta_info), GFP_KERNEL);
 408}
 409
 410static inline void free_part_info(struct hd_struct *part)
 411{
 412        kfree(part->info);
 413}
 414
 415/* block/blk-core.c */
 416extern void part_round_stats(int cpu, struct hd_struct *part);
 417
 418/* block/genhd.c */
 419extern void add_disk(struct gendisk *disk);
 420extern void del_gendisk(struct gendisk *gp);
 421extern struct gendisk *get_gendisk(dev_t dev, int *partno);
 422extern struct block_device *bdget_disk(struct gendisk *disk, int partno);
 423
 424extern void set_device_ro(struct block_device *bdev, int flag);
 425extern void set_disk_ro(struct gendisk *disk, int flag);
 426
 427static inline int get_disk_ro(struct gendisk *disk)
 428{
 429        return disk->part0.policy;
 430}
 431
 432extern void disk_block_events(struct gendisk *disk);
 433extern void disk_unblock_events(struct gendisk *disk);
 434extern void disk_flush_events(struct gendisk *disk, unsigned int mask);
 435extern unsigned int disk_clear_events(struct gendisk *disk, unsigned int mask);
 436
 437/* drivers/char/random.c */
 438extern void add_disk_randomness(struct gendisk *disk);
 439extern void rand_initialize_disk(struct gendisk *disk);
 440
 441static inline sector_t get_start_sect(struct block_device *bdev)
 442{
 443        return bdev->bd_part->start_sect;
 444}
 445static inline sector_t get_capacity(struct gendisk *disk)
 446{
 447        return disk->part0.nr_sects;
 448}
 449static inline void set_capacity(struct gendisk *disk, sector_t size)
 450{
 451        disk->part0.nr_sects = size;
 452}
 453
 454#ifdef CONFIG_SOLARIS_X86_PARTITION
 455
 456#define SOLARIS_X86_NUMSLICE    16
 457#define SOLARIS_X86_VTOC_SANE   (0x600DDEEEUL)
 458
 459struct solaris_x86_slice {
 460        __le16 s_tag;           /* ID tag of partition */
 461        __le16 s_flag;          /* permission flags */
 462        __le32 s_start;         /* start sector no of partition */
 463        __le32 s_size;          /* # of blocks in partition */
 464};
 465
 466struct solaris_x86_vtoc {
 467        unsigned int v_bootinfo[3];     /* info needed by mboot (unsupported) */
 468        __le32 v_sanity;                /* to verify vtoc sanity */
 469        __le32 v_version;               /* layout version */
 470        char    v_volume[8];            /* volume name */
 471        __le16  v_sectorsz;             /* sector size in bytes */
 472        __le16  v_nparts;               /* number of partitions */
 473        unsigned int v_reserved[10];    /* free space */
 474        struct solaris_x86_slice
 475                v_slice[SOLARIS_X86_NUMSLICE]; /* slice headers */
 476        unsigned int timestamp[SOLARIS_X86_NUMSLICE]; /* timestamp (unsupported) */
 477        char    v_asciilabel[128];      /* for compatibility */
 478};
 479
 480#endif /* CONFIG_SOLARIS_X86_PARTITION */
 481
 482#ifdef CONFIG_BSD_DISKLABEL
 483/*
 484 * BSD disklabel support by Yossi Gottlieb <yogo@math.tau.ac.il>
 485 * updated by Marc Espie <Marc.Espie@openbsd.org>
 486 */
 487
 488/* check against BSD src/sys/sys/disklabel.h for consistency */
 489
 490#define BSD_DISKMAGIC   (0x82564557UL)  /* The disk magic number */
 491#define BSD_MAXPARTITIONS       16
 492#define OPENBSD_MAXPARTITIONS   16
 493#define BSD_FS_UNUSED           0       /* disklabel unused partition entry ID */
 494struct bsd_disklabel {
 495        __le32  d_magic;                /* the magic number */
 496        __s16   d_type;                 /* drive type */
 497        __s16   d_subtype;              /* controller/d_type specific */
 498        char    d_typename[16];         /* type name, e.g. "eagle" */
 499        char    d_packname[16];                 /* pack identifier */ 
 500        __u32   d_secsize;              /* # of bytes per sector */
 501        __u32   d_nsectors;             /* # of data sectors per track */
 502        __u32   d_ntracks;              /* # of tracks per cylinder */
 503        __u32   d_ncylinders;           /* # of data cylinders per unit */
 504        __u32   d_secpercyl;            /* # of data sectors per cylinder */
 505        __u32   d_secperunit;           /* # of data sectors per unit */
 506        __u16   d_sparespertrack;       /* # of spare sectors per track */
 507        __u16   d_sparespercyl;         /* # of spare sectors per cylinder */
 508        __u32   d_acylinders;           /* # of alt. cylinders per unit */
 509        __u16   d_rpm;                  /* rotational speed */
 510        __u16   d_interleave;           /* hardware sector interleave */
 511        __u16   d_trackskew;            /* sector 0 skew, per track */
 512        __u16   d_cylskew;              /* sector 0 skew, per cylinder */
 513        __u32   d_headswitch;           /* head switch time, usec */
 514        __u32   d_trkseek;              /* track-to-track seek, usec */
 515        __u32   d_flags;                /* generic flags */
 516#define NDDATA 5
 517        __u32   d_drivedata[NDDATA];    /* drive-type specific information */
 518#define NSPARE 5
 519        __u32   d_spare[NSPARE];        /* reserved for future use */
 520        __le32  d_magic2;               /* the magic number (again) */
 521        __le16  d_checksum;             /* xor of data incl. partitions */
 522
 523                        /* filesystem and partition information: */
 524        __le16  d_npartitions;          /* number of partitions in following */
 525        __le32  d_bbsize;               /* size of boot area at sn0, bytes */
 526        __le32  d_sbsize;               /* max size of fs superblock, bytes */
 527        struct  bsd_partition {         /* the partition table */
 528                __le32  p_size;         /* number of sectors in partition */
 529                __le32  p_offset;       /* starting sector */
 530                __le32  p_fsize;        /* filesystem basic fragment size */
 531                __u8    p_fstype;       /* filesystem type, see below */
 532                __u8    p_frag;         /* filesystem fragments per block */
 533                __le16  p_cpg;          /* filesystem cylinders per group */
 534        } d_partitions[BSD_MAXPARTITIONS];      /* actually may be more */
 535};
 536
 537#endif  /* CONFIG_BSD_DISKLABEL */
 538
 539#ifdef CONFIG_UNIXWARE_DISKLABEL
 540/*
 541 * Unixware slices support by Andrzej Krzysztofowicz <ankry@mif.pg.gda.pl>
 542 * and Krzysztof G. Baranowski <kgb@knm.org.pl>
 543 */
 544
 545#define UNIXWARE_DISKMAGIC     (0xCA5E600DUL)   /* The disk magic number */
 546#define UNIXWARE_DISKMAGIC2    (0x600DDEEEUL)   /* The slice table magic nr */
 547#define UNIXWARE_NUMSLICE      16
 548#define UNIXWARE_FS_UNUSED     0                /* Unused slice entry ID */
 549
 550struct unixware_slice {
 551        __le16   s_label;       /* label */
 552        __le16   s_flags;       /* permission flags */
 553        __le32   start_sect;    /* starting sector */
 554        __le32   nr_sects;      /* number of sectors in slice */
 555};
 556
 557struct unixware_disklabel {
 558        __le32   d_type;                /* drive type */
 559        __le32   d_magic;                /* the magic number */
 560        __le32   d_version;              /* version number */
 561        char    d_serial[12];           /* serial number of the device */
 562        __le32   d_ncylinders;           /* # of data cylinders per device */
 563        __le32   d_ntracks;              /* # of tracks per cylinder */
 564        __le32   d_nsectors;             /* # of data sectors per track */
 565        __le32   d_secsize;              /* # of bytes per sector */
 566        __le32   d_part_start;           /* # of first sector of this partition */
 567        __le32   d_unknown1[12];         /* ? */
 568        __le32  d_alt_tbl;              /* byte offset of alternate table */
 569        __le32  d_alt_len;              /* byte length of alternate table */
 570        __le32  d_phys_cyl;             /* # of physical cylinders per device */
 571        __le32  d_phys_trk;             /* # of physical tracks per cylinder */
 572        __le32  d_phys_sec;             /* # of physical sectors per track */
 573        __le32  d_phys_bytes;           /* # of physical bytes per sector */
 574        __le32  d_unknown2;             /* ? */
 575        __le32   d_unknown3;             /* ? */
 576        __le32  d_pad[8];               /* pad */
 577
 578        struct unixware_vtoc {
 579                __le32  v_magic;                /* the magic number */
 580                __le32  v_version;              /* version number */
 581                char    v_name[8];              /* volume name */
 582                __le16  v_nslices;              /* # of slices */
 583                __le16  v_unknown1;             /* ? */
 584                __le32  v_reserved[10];         /* reserved */
 585                struct unixware_slice
 586                        v_slice[UNIXWARE_NUMSLICE];     /* slice headers */
 587        } vtoc;
 588
 589};  /* 408 */
 590
 591#endif /* CONFIG_UNIXWARE_DISKLABEL */
 592
 593#ifdef CONFIG_MINIX_SUBPARTITION
 594#   define MINIX_NR_SUBPARTITIONS  4
 595#endif /* CONFIG_MINIX_SUBPARTITION */
 596
 597#define ADDPART_FLAG_NONE       0
 598#define ADDPART_FLAG_RAID       1
 599#define ADDPART_FLAG_WHOLEDISK  2
 600
 601extern int blk_alloc_devt(struct hd_struct *part, dev_t *devt);
 602extern void blk_free_devt(dev_t devt);
 603extern dev_t blk_lookup_devt(const char *name, int partno);
 604extern char *disk_name (struct gendisk *hd, int partno, char *buf);
 605
 606extern int disk_expand_part_tbl(struct gendisk *disk, int target);
 607extern int rescan_partitions(struct gendisk *disk, struct block_device *bdev);
 608extern int invalidate_partitions(struct gendisk *disk, struct block_device *bdev);
 609extern struct hd_struct * __must_check add_partition(struct gendisk *disk,
 610                                                     int partno, sector_t start,
 611                                                     sector_t len, int flags,
 612                                                     struct partition_meta_info
 613                                                       *info);
 614extern void __delete_partition(struct hd_struct *);
 615extern void delete_partition(struct gendisk *, int);
 616extern void printk_all_partitions(void);
 617
 618extern struct gendisk *alloc_disk_node(int minors, int node_id);
 619extern struct gendisk *alloc_disk(int minors);
 620extern struct kobject *get_disk(struct gendisk *disk);
 621extern void put_disk(struct gendisk *disk);
 622extern void blk_register_region(dev_t devt, unsigned long range,
 623                        struct module *module,
 624                        struct kobject *(*probe)(dev_t, int *, void *),
 625                        int (*lock)(dev_t, void *),
 626                        void *data);
 627extern void blk_unregister_region(dev_t devt, unsigned long range);
 628
 629extern ssize_t part_size_show(struct device *dev,
 630                              struct device_attribute *attr, char *buf);
 631extern ssize_t part_stat_show(struct device *dev,
 632                              struct device_attribute *attr, char *buf);
 633extern ssize_t part_inflight_show(struct device *dev,
 634                              struct device_attribute *attr, char *buf);
 635#ifdef CONFIG_FAIL_MAKE_REQUEST
 636extern ssize_t part_fail_show(struct device *dev,
 637                              struct device_attribute *attr, char *buf);
 638extern ssize_t part_fail_store(struct device *dev,
 639                               struct device_attribute *attr,
 640                               const char *buf, size_t count);
 641#endif /* CONFIG_FAIL_MAKE_REQUEST */
 642
 643static inline void hd_ref_init(struct hd_struct *part)
 644{
 645        atomic_set(&part->ref, 1);
 646        smp_mb();
 647}
 648
 649static inline void hd_struct_get(struct hd_struct *part)
 650{
 651        atomic_inc(&part->ref);
 652        smp_mb__after_atomic_inc();
 653}
 654
 655static inline int hd_struct_try_get(struct hd_struct *part)
 656{
 657        return atomic_inc_not_zero(&part->ref);
 658}
 659
 660static inline void hd_struct_put(struct hd_struct *part)
 661{
 662        if (atomic_dec_and_test(&part->ref))
 663                __delete_partition(part);
 664}
 665
 666/*
 667 * Any access of part->nr_sects which is not protected by partition
 668 * bd_mutex or gendisk bdev bd_mutex, should be done using this
 669 * accessor function.
 670 *
 671 * Code written along the lines of i_size_read() and i_size_write().
 672 * CONFIG_PREEMPT case optimizes the case of UP kernel with preemption
 673 * on.
 674 */
 675static inline sector_t part_nr_sects_read(struct hd_struct *part)
 676{
 677#if BITS_PER_LONG==32 && defined(CONFIG_LBDAF) && defined(CONFIG_SMP)
 678        sector_t nr_sects;
 679        unsigned seq;
 680        do {
 681                seq = read_seqcount_begin(&part->nr_sects_seq);
 682                nr_sects = part->nr_sects;
 683        } while (read_seqcount_retry(&part->nr_sects_seq, seq));
 684        return nr_sects;
 685#elif BITS_PER_LONG==32 && defined(CONFIG_LBDAF) && defined(CONFIG_PREEMPT)
 686        sector_t nr_sects;
 687
 688        preempt_disable();
 689        nr_sects = part->nr_sects;
 690        preempt_enable();
 691        return nr_sects;
 692#else
 693        return part->nr_sects;
 694#endif
 695}
 696
 697/*
 698 * Should be called with mutex lock held (typically bd_mutex) of partition
 699 * to provide mutual exlusion among writers otherwise seqcount might be
 700 * left in wrong state leaving the readers spinning infinitely.
 701 */
 702static inline void part_nr_sects_write(struct hd_struct *part, sector_t size)
 703{
 704#if BITS_PER_LONG==32 && defined(CONFIG_LBDAF) && defined(CONFIG_SMP)
 705        write_seqcount_begin(&part->nr_sects_seq);
 706        part->nr_sects = size;
 707        write_seqcount_end(&part->nr_sects_seq);
 708#elif BITS_PER_LONG==32 && defined(CONFIG_LBDAF) && defined(CONFIG_PREEMPT)
 709        preempt_disable();
 710        part->nr_sects = size;
 711        preempt_enable();
 712#else
 713        part->nr_sects = size;
 714#endif
 715}
 716
 717#else /* CONFIG_BLOCK */
 718
 719static inline void printk_all_partitions(void) { }
 720
 721static inline dev_t blk_lookup_devt(const char *name, int partno)
 722{
 723        dev_t devt = MKDEV(0, 0);
 724        return devt;
 725}
 726
 727static inline int blk_part_pack_uuid(const u8 *uuid_str, u8 *to)
 728{
 729        return -EINVAL;
 730}
 731#endif /* CONFIG_BLOCK */
 732
 733#endif /* _LINUX_GENHD_H */
 734
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