include/linux/genhd.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _LINUX_GENHD_H
   3 #define _LINUX_GENHD_H
   4
   5 /*
   6  *      genhd.h Copyright (C) 1992 Drew Eckhardt
   7  *      Generic hard disk header file by
   8  *              Drew Eckhardt
   9  *
  10  *              <drew@colorado.edu>
  11  */
  12
  13 #include <linux/types.h>
  14 #include <linux/kdev_t.h>
  15 #include <linux/rcupdate.h>
  16 #include <linux/slab.h>
  17 #include <linux/percpu-refcount.h>
  18 #include <linux/uuid.h>
  19
  20 #ifdef CONFIG_BLOCK
  21
  22 #define dev_to_disk(device)     container_of((device), struct gendisk, part0.__dev)
  23 #define dev_to_part(device)     container_of((device), struct hd_struct, __dev)
  24 #define disk_to_dev(disk)       (&(disk)->part0.__dev)
  25 #define part_to_dev(part)       (&((part)->__dev))
  26
  27 extern struct device_type part_type;
  28 extern struct kobject *block_depr;
  29 extern struct class block_class;
  30
  31 enum {
  32 /* These three have identical behaviour; use the second one if DOS FDISK gets
  33    confused about extended/logical partitions starting past cylinder 1023. */
  34         DOS_EXTENDED_PARTITION = 5,
  35         LINUX_EXTENDED_PARTITION = 0x85,
  36         WIN98_EXTENDED_PARTITION = 0x0f,
  37
  38         SUN_WHOLE_DISK = DOS_EXTENDED_PARTITION,
  39
  40         LINUX_SWAP_PARTITION = 0x82,
  41         LINUX_DATA_PARTITION = 0x83,
  42         LINUX_LVM_PARTITION = 0x8e,
  43         LINUX_RAID_PARTITION = 0xfd,    /* autodetect RAID partition */
  44
  45         SOLARIS_X86_PARTITION = LINUX_SWAP_PARTITION,
  46         NEW_SOLARIS_X86_PARTITION = 0xbf,
  47
  48         DM6_AUX1PARTITION = 0x51,       /* no DDO:  use xlated geom */
  49         DM6_AUX3PARTITION = 0x53,       /* no DDO:  use xlated geom */
  50         DM6_PARTITION = 0x54,           /* has DDO: use xlated geom & offset */
  51         EZD_PARTITION = 0x55,           /* EZ-DRIVE */
  52
  53         FREEBSD_PARTITION = 0xa5,       /* FreeBSD Partition ID */
  54         OPENBSD_PARTITION = 0xa6,       /* OpenBSD Partition ID */
  55         NETBSD_PARTITION = 0xa9,        /* NetBSD Partition ID */
  56         BSDI_PARTITION = 0xb7,          /* BSDI Partition ID */
  57         MINIX_PARTITION = 0x81,         /* Minix Partition ID */
  58         UNIXWARE_PARTITION = 0x63,      /* Same as GNU_HURD and SCO Unix */
  59 };
  60
  61 #define DISK_MAX_PARTS                  256
  62 #define DISK_NAME_LEN                   32
  63
  64 #include <linux/major.h>
  65 #include <linux/device.h>
  66 #include <linux/smp.h>
  67 #include <linux/string.h>
  68 #include <linux/fs.h>
  69 #include <linux/workqueue.h>
  70
  71 struct partition {
  72         unsigned char boot_ind;         /* 0x80 - active */
  73         unsigned char head;             /* starting head */
  74         unsigned char sector;           /* starting sector */
  75         unsigned char cyl;              /* starting cylinder */
  76         unsigned char sys_ind;          /* What partition type */
  77         unsigned char end_head;         /* end head */
  78         unsigned char end_sector;       /* end sector */
  79         unsigned char end_cyl;          /* end cylinder */
  80         __le32 start_sect;      /* starting sector counting from 0 */
  81         __le32 nr_sects;                /* nr of sectors in partition */
  82 } __attribute__((packed));
  83
  84 struct disk_stats {
  85         unsigned long sectors[2];       /* READs and WRITEs */
  86         unsigned long ios[2];
  87         unsigned long merges[2];
  88         unsigned long ticks[2];
  89         unsigned long io_ticks;
  90         unsigned long time_in_queue;
  91 };
  92
  93 #define PARTITION_META_INFO_VOLNAMELTH  64
  94 /*
  95  * Enough for the string representation of any kind of UUID plus NULL.
  96  * EFI UUID is 36 characters. MSDOS UUID is 11 characters.
  97  */
  98 #define PARTITION_META_INFO_UUIDLTH     (UUID_STRING_LEN + 1)
  99
 100 struct partition_meta_info {
 101         char uuid[PARTITION_META_INFO_UUIDLTH];
 102         u8 volname[PARTITION_META_INFO_VOLNAMELTH];
 103 };
 104
 105 struct hd_struct {
 106         sector_t start_sect;
 107         /*
 108          * nr_sects is protected by sequence counter. One might extend a
 109          * partition while IO is happening to it and update of nr_sects
 110          * can be non-atomic on 32bit machines with 64bit sector_t.
 111          */
 112         sector_t nr_sects;
 113         seqcount_t nr_sects_seq;
 114         sector_t alignment_offset;
 115         unsigned int discard_alignment;
 116         struct device __dev;
 117         struct kobject *holder_dir;
 118         int policy, partno;
 119         struct partition_meta_info *info;
 120 #ifdef CONFIG_FAIL_MAKE_REQUEST
 121         int make_it_fail;
 122 #endif
 123         unsigned long stamp;
 124         atomic_t in_flight[2];
 125 #ifdef  CONFIG_SMP
 126         struct disk_stats __percpu *dkstats;
 127 #else
 128         struct disk_stats dkstats;
 129 #endif
 130         struct percpu_ref ref;
 131         struct rcu_head rcu_head;
 132 };
 133
 134 #define GENHD_FL_REMOVABLE                      1
 135 /* 2 is unused */
 136 #define GENHD_FL_MEDIA_CHANGE_NOTIFY            4
 137 #define GENHD_FL_CD                             8
 138 #define GENHD_FL_UP                             16
 139 #define GENHD_FL_SUPPRESS_PARTITION_INFO        32
 140 #define GENHD_FL_EXT_DEVT                       64 /* allow extended devt */
 141 #define GENHD_FL_NATIVE_CAPACITY                128
 142 #define GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE     256
 143 #define GENHD_FL_NO_PART_SCAN                   512
 144 #define GENHD_FL_HIDDEN                         1024
 145
 146 enum {
 147         DISK_EVENT_MEDIA_CHANGE                 = 1 << 0, /* media changed */
 148         DISK_EVENT_EJECT_REQUEST                = 1 << 1, /* eject requested */
 149 };
 150
 151 struct disk_part_tbl {
 152         struct rcu_head rcu_head;
 153         int len;
 154         struct hd_struct __rcu *last_lookup;
 155         struct hd_struct __rcu *part[];
 156 };
 157
 158 struct disk_events;
 159 struct badblocks;
 160
 161 #if defined(CONFIG_BLK_DEV_INTEGRITY)
 162
 163 struct blk_integrity {
 164         const struct blk_integrity_profile      *profile;
 165         unsigned char                           flags;
 166         unsigned char                           tuple_size;
 167         unsigned char                           interval_exp;
 168         unsigned char                           tag_size;
 169 };
 170
 171 #endif  /* CONFIG_BLK_DEV_INTEGRITY */
 172
 173 struct gendisk {
 174         /* major, first_minor and minors are input parameters only,
 175          * don't use directly.  Use disk_devt() and disk_max_parts().
 176          */
 177         int major;                      /* major number of driver */
 178         int first_minor;
 179         int minors;                     /* maximum number of minors, =1 for
 180                                          * disks that can't be partitioned. */
 181
 182         char disk_name[DISK_NAME_LEN];  /* name of major driver */
 183         char *(*devnode)(struct gendisk *gd, umode_t *mode);
 184
 185         unsigned int events;            /* supported events */
 186         unsigned int async_events;      /* async events, subset of all */
 187
 188         /* Array of pointers to partitions indexed by partno.
 189          * Protected with matching bdev lock but stat and other
 190          * non-critical accesses use RCU.  Always access through
 191          * helpers.
 192          */
 193         struct disk_part_tbl __rcu *part_tbl;
 194         struct hd_struct part0;
 195
 196         const struct block_device_operations *fops;
 197         struct request_queue *queue;
 198         void *private_data;
 199
 200         int flags;
 201         struct rw_semaphore lookup_sem;
 202         struct kobject *slave_dir;
 203
 204         struct timer_rand_state *random;
 205         atomic_t sync_io;               /* RAID */
 206         struct disk_events *ev;
 207 #ifdef  CONFIG_BLK_DEV_INTEGRITY
 208         struct kobject integrity_kobj;
 209 #endif  /* CONFIG_BLK_DEV_INTEGRITY */
 210         int node_id;
 211         struct badblocks *bb;
 212         struct lockdep_map lockdep_map;
 213 };
 214
 215 static inline struct gendisk *part_to_disk(struct hd_struct *part)
 216 {
 217         if (likely(part)) {
 218                 if (part->partno)
 219                         return dev_to_disk(part_to_dev(part)->parent);
 220                 else
 221                         return dev_to_disk(part_to_dev(part));
 222         }
 223         return NULL;
 224 }
 225
 226 static inline int disk_max_parts(struct gendisk *disk)
 227 {
 228         if (disk->flags & GENHD_FL_EXT_DEVT)
 229                 return DISK_MAX_PARTS;
 230         return disk->minors;
 231 }
 232
 233 static inline bool disk_part_scan_enabled(struct gendisk *disk)
 234 {
 235         return disk_max_parts(disk) > 1 &&
 236                 !(disk->flags & GENHD_FL_NO_PART_SCAN);
 237 }
 238
 239 static inline dev_t disk_devt(struct gendisk *disk)
 240 {
 241         return MKDEV(disk->major, disk->first_minor);
 242 }
 243
 244 static inline dev_t part_devt(struct hd_struct *part)
 245 {
 246         return part_to_dev(part)->devt;
 247 }
 248
 249 extern struct hd_struct *__disk_get_part(struct gendisk *disk, int partno);
 250 extern struct hd_struct *disk_get_part(struct gendisk *disk, int partno);
 251
 252 static inline void disk_put_part(struct hd_struct *part)
 253 {
 254         if (likely(part))
 255                 put_device(part_to_dev(part));
 256 }
 257
 258 /*
 259  * Smarter partition iterator without context limits.
 260  */
 261 #define DISK_PITER_REVERSE      (1 << 0) /* iterate in the reverse direction */
 262 #define DISK_PITER_INCL_EMPTY   (1 << 1) /* include 0-sized parts */
 263 #define DISK_PITER_INCL_PART0   (1 << 2) /* include partition 0 */
 264 #define DISK_PITER_INCL_EMPTY_PART0 (1 << 3) /* include empty partition 0 */
 265
 266 struct disk_part_iter {
 267         struct gendisk          *disk;
 268         struct hd_struct        *part;
 269         int                     idx;
 270         unsigned int            flags;
 271 };
 272
 273 extern void disk_part_iter_init(struct disk_part_iter *piter,
 274                                  struct gendisk *disk, unsigned int flags);
 275 extern struct hd_struct *disk_part_iter_next(struct disk_part_iter *piter);
 276 extern void disk_part_iter_exit(struct disk_part_iter *piter);
 277
 278 extern struct hd_struct *disk_map_sector_rcu(struct gendisk *disk,
 279                                              sector_t sector);
 280
 281 /*
 282  * Macros to operate on percpu disk statistics:
 283  *
 284  * {disk|part|all}_stat_{add|sub|inc|dec}() modify the stat counters
 285  * and should be called between disk_stat_lock() and
 286  * disk_stat_unlock().
 287  *
 288  * part_stat_read() can be called at any time.
 289  *
 290  * part_stat_{add|set_all}() and {init|free}_part_stats are for
 291  * internal use only.
 292  */
 293 #ifdef  CONFIG_SMP
 294 #define part_stat_lock()        ({ rcu_read_lock(); get_cpu(); })
 295 #define part_stat_unlock()      do { put_cpu(); rcu_read_unlock(); } while (0)
 296
 297 #define __part_stat_add(cpu, part, field, addnd)                        \
 298         (per_cpu_ptr((part)->dkstats, (cpu))->field += (addnd))
 299
 300 #define part_stat_read(part, field)                                     \
 301 ({                                                                      \
 302         typeof((part)->dkstats->field) res = 0;                         \
 303         unsigned int _cpu;                                              \
 304         for_each_possible_cpu(_cpu)                                     \
 305                 res += per_cpu_ptr((part)->dkstats, _cpu)->field;       \
 306         res;                                                            \
 307 })
 308
 309 static inline void part_stat_set_all(struct hd_struct *part, int value)
 310 {
 311         int i;
 312
 313         for_each_possible_cpu(i)
 314                 memset(per_cpu_ptr(part->dkstats, i), value,
 315                                 sizeof(struct disk_stats));
 316 }
 317
 318 static inline int init_part_stats(struct hd_struct *part)
 319 {
 320         part->dkstats = alloc_percpu(struct disk_stats);
 321         if (!part->dkstats)
 322                 return 0;
 323         return 1;
 324 }
 325
 326 static inline void free_part_stats(struct hd_struct *part)
 327 {
 328         free_percpu(part->dkstats);
 329 }
 330
 331 #else /* !CONFIG_SMP */
 332 #define part_stat_lock()        ({ rcu_read_lock(); 0; })
 333 #define part_stat_unlock()      rcu_read_unlock()
 334
 335 #define __part_stat_add(cpu, part, field, addnd)                                \
 336         ((part)->dkstats.field += addnd)
 337
 338 #define part_stat_read(part, field)     ((part)->dkstats.field)
 339
 340 static inline void part_stat_set_all(struct hd_struct *part, int value)
 341 {
 342         memset(&part->dkstats, value, sizeof(struct disk_stats));
 343 }
 344
 345 static inline int init_part_stats(struct hd_struct *part)
 346 {
 347         return 1;
 348 }
 349
 350 static inline void free_part_stats(struct hd_struct *part)
 351 {
 352 }
 353
 354 #endif /* CONFIG_SMP */
 355
 356 #define part_stat_add(cpu, part, field, addnd)  do {                    \
 357         __part_stat_add((cpu), (part), field, addnd);                   \
 358         if ((part)->partno)                                             \
 359                 __part_stat_add((cpu), &part_to_disk((part))->part0,    \
 360                                 field, addnd);                          \
 361 } while (0)
 362
 363 #define part_stat_dec(cpu, gendiskp, field)                             \
 364         part_stat_add(cpu, gendiskp, field, -1)
 365 #define part_stat_inc(cpu, gendiskp, field)                             \
 366         part_stat_add(cpu, gendiskp, field, 1)
 367 #define part_stat_sub(cpu, gendiskp, field, subnd)                      \
 368         part_stat_add(cpu, gendiskp, field, -subnd)
 369
 370 void part_in_flight(struct request_queue *q, struct hd_struct *part,
 371                     unsigned int inflight[2]);
 372 void part_in_flight_rw(struct request_queue *q, struct hd_struct *part,
 373                        unsigned int inflight[2]);
 374 void part_dec_in_flight(struct request_queue *q, struct hd_struct *part,
 375                         int rw);
 376 void part_inc_in_flight(struct request_queue *q, struct hd_struct *part,
 377                         int rw);
 378
 379 static inline struct partition_meta_info *alloc_part_info(struct gendisk *disk)
 380 {
 381         if (disk)
 382                 return kzalloc_node(sizeof(struct partition_meta_info),
 383                                     GFP_KERNEL, disk->node_id);
 384         return kzalloc(sizeof(struct partition_meta_info), GFP_KERNEL);
 385 }
 386
 387 static inline void free_part_info(struct hd_struct *part)
 388 {
 389         kfree(part->info);
 390 }
 391
 392 /* block/blk-core.c */
 393 extern void part_round_stats(struct request_queue *q, int cpu, struct hd_struct *part);
 394
 395 /* block/genhd.c */
 396 extern void device_add_disk(struct device *parent, struct gendisk *disk);
 397 static inline void add_disk(struct gendisk *disk)
 398 {
 399         device_add_disk(NULL, disk);
 400 }
 401 extern void device_add_disk_no_queue_reg(struct device *parent, struct gendisk *disk);
 402 static inline void add_disk_no_queue_reg(struct gendisk *disk)
 403 {
 404         device_add_disk_no_queue_reg(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 kobject *get_disk_and_module(struct gendisk *disk);
 607 extern void put_disk(struct gendisk *disk);
 608 extern void put_disk_and_module(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 #define alloc_disk_node(minors, node_id)                                \
 631 ({                                                                      \
 632         static struct lock_class_key __key;                             \
 633         const char *__name;                                             \
 634         struct gendisk *__disk;                                         \
 635                                                                         \
 636         __name = "(gendisk_completion)"#minors"("#node_id")";           \
 637                                                                         \
 638         __disk = __alloc_disk_node(minors, node_id);                    \
 639                                                                         \
 640         if (__disk)                                                     \
 641                 lockdep_init_map(&__disk->lockdep_map, __name, &__key, 0); \
 642                                                                         \
 643         __disk;                                                         \
 644 })
 645
 646 #define alloc_disk(minors) alloc_disk_node(minors, NUMA_NO_NODE)
 647
 648 static inline int hd_ref_init(struct hd_struct *part)
 649 {
 650         if (percpu_ref_init(&part->ref, __delete_partition, 0,
 651                                 GFP_KERNEL))
 652                 return -ENOMEM;
 653         return 0;
 654 }
 655
 656 static inline void hd_struct_get(struct hd_struct *part)
 657 {
 658         percpu_ref_get(&part->ref);
 659 }
 660
 661 static inline int hd_struct_try_get(struct hd_struct *part)
 662 {
 663         return percpu_ref_tryget_live(&part->ref);
 664 }
 665
 666 static inline void hd_struct_put(struct hd_struct *part)
 667 {
 668         percpu_ref_put(&part->ref);
 669 }
 670
 671 static inline void hd_struct_kill(struct hd_struct *part)
 672 {
 673         percpu_ref_kill(&part->ref);
 674 }
 675
 676 static inline void hd_free_part(struct hd_struct *part)
 677 {
 678         free_part_stats(part);
 679         free_part_info(part);
 680         percpu_ref_exit(&part->ref);
 681 }
 682
 683 /*
 684  * Any access of part->nr_sects which is not protected by partition
 685  * bd_mutex or gendisk bdev bd_mutex, should be done using this
 686  * accessor function.
 687  *
 688  * Code written along the lines of i_size_read() and i_size_write().
 689  * CONFIG_PREEMPT case optimizes the case of UP kernel with preemption
 690  * on.
 691  */
 692 static inline sector_t part_nr_sects_read(struct hd_struct *part)
 693 {
 694 #if BITS_PER_LONG==32 && defined(CONFIG_LBDAF) && defined(CONFIG_SMP)
 695         sector_t nr_sects;
 696         unsigned seq;
 697         do {
 698                 seq = read_seqcount_begin(&part->nr_sects_seq);
 699                 nr_sects = part->nr_sects;
 700         } while (read_seqcount_retry(&part->nr_sects_seq, seq));
 701         return nr_sects;
 702 #elif BITS_PER_LONG==32 && defined(CONFIG_LBDAF) && defined(CONFIG_PREEMPT)
 703         sector_t nr_sects;
 704
 705         preempt_disable();
 706         nr_sects = part->nr_sects;
 707         preempt_enable();
 708         return nr_sects;
 709 #else
 710         return part->nr_sects;
 711 #endif
 712 }
 713
 714 /*
 715  * Should be called with mutex lock held (typically bd_mutex) of partition
 716  * to provide mutual exlusion among writers otherwise seqcount might be
 717  * left in wrong state leaving the readers spinning infinitely.
 718  */
 719 static inline void part_nr_sects_write(struct hd_struct *part, sector_t size)
 720 {
 721 #if BITS_PER_LONG==32 && defined(CONFIG_LBDAF) && defined(CONFIG_SMP)
 722         write_seqcount_begin(&part->nr_sects_seq);
 723         part->nr_sects = size;
 724         write_seqcount_end(&part->nr_sects_seq);
 725 #elif BITS_PER_LONG==32 && defined(CONFIG_LBDAF) && defined(CONFIG_PREEMPT)
 726         preempt_disable();
 727         part->nr_sects = size;
 728         preempt_enable();
 729 #else
 730         part->nr_sects = size;
 731 #endif
 732 }
 733
 734 #if defined(CONFIG_BLK_DEV_INTEGRITY)
 735 extern void blk_integrity_add(struct gendisk *);
 736 extern void blk_integrity_del(struct gendisk *);
 737 #else   /* CONFIG_BLK_DEV_INTEGRITY */
 738 static inline void blk_integrity_add(struct gendisk *disk) { }
 739 static inline void blk_integrity_del(struct gendisk *disk) { }
 740 #endif  /* CONFIG_BLK_DEV_INTEGRITY */
 741
 742 #else /* CONFIG_BLOCK */
 743
 744 static inline void printk_all_partitions(void) { }
 745
 746 static inline dev_t blk_lookup_devt(const char *name, int partno)
 747 {
 748         dev_t devt = MKDEV(0, 0);
 749         return devt;
 750 }
 751 #endif /* CONFIG_BLOCK */
 752
 753 #endif /* _LINUX_GENHD_H */