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