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