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