include/linux/genhd.h

   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
  24 extern struct device_type part_type;
  25 extern struct kobject *block_depr;
  26 extern struct class block_class;
  27
  28 enum {
  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
  68 struct 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
  81 struct 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
  93 struct partition_meta_info {
  94         u8 uuid[PARTITION_META_INFO_UUIDLTH];   /* always big endian */
  95         u8 volname[PARTITION_META_INFO_VOLNAMELTH];
  96 };
  97
  98 struct 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
 138 enum {
 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
 146 struct 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
 152 struct 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
 159 struct disk_events;
 160
 161 struct 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
 201 static 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
 212 static 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
 230 static 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
 237 static 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
 243 static inline dev_t disk_devt(struct gendisk *disk)
 244 {
 245         return disk_to_dev(disk)->devt;
 246 }
 247
 248 static inline dev_t part_devt(struct hd_struct *part)
 249 {
 250         return part_to_dev(part)->devt;
 251 }
 252
 253 extern struct hd_struct *disk_get_part(struct gendisk *disk, int partno);
 254
 255 static 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
 269 struct disk_part_iter {
 270         struct gendisk          *disk;
 271         struct hd_struct        *part;
 272         int                     idx;
 273         unsigned int            flags;
 274 };
 275
 276 extern void disk_part_iter_init(struct disk_part_iter *piter,
 277                                  struct gendisk *disk, unsigned int flags);
 278 extern struct hd_struct *disk_part_iter_next(struct disk_part_iter *piter);
 279 extern void disk_part_iter_exit(struct disk_part_iter *piter);
 280
 281 extern 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
 312 static 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
 321 static 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
 329 static 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
 343 static inline void part_stat_set_all(struct hd_struct *part, int value)
 344 {
 345         memset(&part->dkstats, value, sizeof(struct disk_stats));
 346 }
 347
 348 static inline int init_part_stats(struct hd_struct *part)
 349 {
 350         return 1;
 351 }
 352
 353 static 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
 373 static 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
 380 static 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
 387 static 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
 392 static 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
 400 static inline void free_part_info(struct hd_struct *part)
 401 {
 402         kfree(part->info);
 403 }
 404
 405 /* block/blk-core.c */
 406 extern void part_round_stats(int cpu, struct hd_struct *part);
 407
 408 /* block/genhd.c */
 409 extern void add_disk(struct gendisk *disk);
 410 extern void del_gendisk(struct gendisk *gp);
 411 extern struct gendisk *get_gendisk(dev_t dev, int *partno);
 412 extern struct block_device *bdget_disk(struct gendisk *disk, int partno);
 413
 414 extern void set_device_ro(struct block_device *bdev, int flag);
 415 extern void set_disk_ro(struct gendisk *disk, int flag);
 416
 417 static inline int get_disk_ro(struct gendisk *disk)
 418 {
 419         return disk->part0.policy;
 420 }
 421
 422 extern void disk_block_events(struct gendisk *disk);
 423 extern void disk_unblock_events(struct gendisk *disk);
 424 extern void disk_flush_events(struct gendisk *disk, unsigned int mask);
 425 extern unsigned int disk_clear_events(struct gendisk *disk, unsigned int mask);
 426
 427 /* drivers/char/random.c */
 428 extern void add_disk_randomness(struct gendisk *disk);
 429 extern void rand_initialize_disk(struct gendisk *disk);
 430
 431 static inline sector_t get_start_sect(struct block_device *bdev)
 432 {
 433         return bdev->bd_part->start_sect;
 434 }
 435 static inline sector_t get_capacity(struct gendisk *disk)
 436 {
 437         return disk->part0.nr_sects;
 438 }
 439 static 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
 449 struct 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
 456 struct 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 */
 484 struct 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
 540 struct 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
 547 struct 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
 591 extern int blk_alloc_devt(struct hd_struct *part, dev_t *devt);
 592 extern void blk_free_devt(dev_t devt);
 593 extern dev_t blk_lookup_devt(const char *name, int partno);
 594 extern char *disk_name (struct gendisk *hd, int partno, char *buf);
 595
 596 extern int disk_expand_part_tbl(struct gendisk *disk, int target);
 597 extern int rescan_partitions(struct gendisk *disk, struct block_device *bdev);
 598 extern int invalidate_partitions(struct gendisk *disk, struct block_device *bdev);
 599 extern 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);
 604 extern void __delete_partition(struct hd_struct *);
 605 extern void delete_partition(struct gendisk *, int);
 606 extern void printk_all_partitions(void);
 607
 608 extern struct gendisk *alloc_disk_node(int minors, int node_id);
 609 extern struct gendisk *alloc_disk(int minors);
 610 extern struct kobject *get_disk(struct gendisk *disk);
 611 extern void put_disk(struct gendisk *disk);
 612 extern 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);
 617 extern void blk_unregister_region(dev_t devt, unsigned long range);
 618
 619 extern ssize_t part_size_show(struct device *dev,
 620                               struct device_attribute *attr, char *buf);
 621 extern ssize_t part_stat_show(struct device *dev,
 622                               struct device_attribute *attr, char *buf);
 623 extern ssize_t part_inflight_show(struct device *dev,
 624                               struct device_attribute *attr, char *buf);
 625 #ifdef CONFIG_FAIL_MAKE_REQUEST
 626 extern ssize_t part_fail_show(struct device *dev,
 627                               struct device_attribute *attr, char *buf);
 628 extern 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
 633 static inline void hd_ref_init(struct hd_struct *part)
 634 {
 635         atomic_set(&part->ref, 1);
 636         smp_mb();
 637 }
 638
 639 static inline void hd_struct_get(struct hd_struct *part)
 640 {
 641         atomic_inc(&part->ref);
 642         smp_mb__after_atomic_inc();
 643 }
 644
 645 static inline int hd_struct_try_get(struct hd_struct *part)
 646 {
 647         return atomic_inc_not_zero(&part->ref);
 648 }
 649
 650 static 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  */
 665 static 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  */
 692 static 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
 709 static inline void printk_all_partitions(void) { }
 710
 711 static 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 */