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
 145 enum {
 146         DISK_EVENT_MEDIA_CHANGE                 = 1 << 0, /* media changed */
 147         DISK_EVENT_EJECT_REQUEST                = 1 << 1, /* eject requested */
 148 };
 149
 150 struct disk_part_tbl {
 151         struct rcu_head rcu_head;
 152         int len;
 153         struct hd_struct __rcu *last_lookup;
 154         struct hd_struct __rcu *part[];
 155 };
 156
 157 struct disk_events;
 158 struct badblocks;
 159
 160 #if defined(CONFIG_BLK_DEV_INTEGRITY)
 161
 162 struct blk_integrity {
 163         const struct blk_integrity_profile      *profile;
 164         unsigned char                           flags;
 165         unsigned char                           tuple_size;
 166         unsigned char                           interval_exp;
 167         unsigned char                           tag_size;
 168 };
 169
 170 #endif  /* CONFIG_BLK_DEV_INTEGRITY */
 171
 172 struct gendisk {
 173         /* major, first_minor and minors are input parameters only,
 174          * don't use directly.  Use disk_devt() and disk_max_parts().
 175          */
 176         int major;                      /* major number of driver */
 177         int first_minor;
 178         int minors;                     /* maximum number of minors, =1 for
 179                                          * disks that can't be partitioned. */
 180
 181         char disk_name[DISK_NAME_LEN];  /* name of major driver */
 182         char *(*devnode)(struct gendisk *gd, umode_t *mode);
 183
 184         unsigned int events;            /* supported events */
 185         unsigned int async_events;      /* async events, subset of all */
 186
 187         /* Array of pointers to partitions indexed by partno.
 188          * Protected with matching bdev lock but stat and other
 189          * non-critical accesses use RCU.  Always access through
 190          * helpers.
 191          */
 192         struct disk_part_tbl __rcu *part_tbl;
 193         struct hd_struct part0;
 194
 195         const struct block_device_operations *fops;
 196         struct request_queue *queue;
 197         void *private_data;
 198
 199         int flags;
 200         struct kobject *slave_dir;
 201
 202         struct timer_rand_state *random;
 203         atomic_t sync_io;               /* RAID */
 204         struct disk_events *ev;
 205 #ifdef  CONFIG_BLK_DEV_INTEGRITY
 206         struct kobject integrity_kobj;
 207 #endif  /* CONFIG_BLK_DEV_INTEGRITY */
 208         int node_id;
 209         struct badblocks *bb;
 210 };
 211
 212 static inline struct gendisk *part_to_disk(struct hd_struct *part)
 213 {
 214         if (likely(part)) {
 215                 if (part->partno)
 216                         return dev_to_disk(part_to_dev(part)->parent);
 217                 else
 218                         return dev_to_disk(part_to_dev(part));
 219         }
 220         return NULL;
 221 }
 222
 223 static inline int disk_max_parts(struct gendisk *disk)
 224 {
 225         if (disk->flags & GENHD_FL_EXT_DEVT)
 226                 return DISK_MAX_PARTS;
 227         return disk->minors;
 228 }
 229
 230 static inline bool disk_part_scan_enabled(struct gendisk *disk)
 231 {
 232         return disk_max_parts(disk) > 1 &&
 233                 !(disk->flags & GENHD_FL_NO_PART_SCAN);
 234 }
 235
 236 static inline dev_t disk_devt(struct gendisk *disk)
 237 {
 238         return disk_to_dev(disk)->devt;
 239 }
 240
 241 static inline dev_t part_devt(struct hd_struct *part)
 242 {
 243         return part_to_dev(part)->devt;
 244 }
 245
 246 extern struct hd_struct *__disk_get_part(struct gendisk *disk, int partno);
 247 extern struct hd_struct *disk_get_part(struct gendisk *disk, int partno);
 248
 249 static inline void disk_put_part(struct hd_struct *part)
 250 {
 251         if (likely(part))
 252                 put_device(part_to_dev(part));
 253 }
 254
 255 /*
 256  * Smarter partition iterator without context limits.
 257  */
 258 #define DISK_PITER_REVERSE      (1 << 0) /* iterate in the reverse direction */
 259 #define DISK_PITER_INCL_EMPTY   (1 << 1) /* include 0-sized parts */
 260 #define DISK_PITER_INCL_PART0   (1 << 2) /* include partition 0 */
 261 #define DISK_PITER_INCL_EMPTY_PART0 (1 << 3) /* include empty partition 0 */
 262
 263 struct disk_part_iter {
 264         struct gendisk          *disk;
 265         struct hd_struct        *part;
 266         int                     idx;
 267         unsigned int            flags;
 268 };
 269
 270 extern void disk_part_iter_init(struct disk_part_iter *piter,
 271                                  struct gendisk *disk, unsigned int flags);
 272 extern struct hd_struct *disk_part_iter_next(struct disk_part_iter *piter);
 273 extern void disk_part_iter_exit(struct disk_part_iter *piter);
 274
 275 extern struct hd_struct *disk_map_sector_rcu(struct gendisk *disk,
 276                                              sector_t sector);
 277
 278 /*
 279  * Macros to operate on percpu disk statistics:
 280  *
 281  * {disk|part|all}_stat_{add|sub|inc|dec}() modify the stat counters
 282  * and should be called between disk_stat_lock() and
 283  * disk_stat_unlock().
 284  *
 285  * part_stat_read() can be called at any time.
 286  *
 287  * part_stat_{add|set_all}() and {init|free}_part_stats are for
 288  * internal use only.
 289  */
 290 #ifdef  CONFIG_SMP
 291 #define part_stat_lock()        ({ rcu_read_lock(); get_cpu(); })
 292 #define part_stat_unlock()      do { put_cpu(); rcu_read_unlock(); } while (0)
 293
 294 #define __part_stat_add(cpu, part, field, addnd)                        \
 295         (per_cpu_ptr((part)->dkstats, (cpu))->field += (addnd))
 296
 297 #define part_stat_read(part, field)                                     \
 298 ({                                                                      \
 299         typeof((part)->dkstats->field) res = 0;                         \
 300         unsigned int _cpu;                                              \
 301         for_each_possible_cpu(_cpu)                                     \
 302                 res += per_cpu_ptr((part)->dkstats, _cpu)->field;       \
 303         res;                                                            \
 304 })
 305
 306 static inline void part_stat_set_all(struct hd_struct *part, int value)
 307 {
 308         int i;
 309
 310         for_each_possible_cpu(i)
 311                 memset(per_cpu_ptr(part->dkstats, i), value,
 312                                 sizeof(struct disk_stats));
 313 }
 314
 315 static inline int init_part_stats(struct hd_struct *part)
 316 {
 317         part->dkstats = alloc_percpu(struct disk_stats);
 318         if (!part->dkstats)
 319                 return 0;
 320         return 1;
 321 }
 322
 323 static inline void free_part_stats(struct hd_struct *part)
 324 {
 325         free_percpu(part->dkstats);
 326 }
 327
 328 #else /* !CONFIG_SMP */
 329 #define part_stat_lock()        ({ rcu_read_lock(); 0; })
 330 #define part_stat_unlock()      rcu_read_unlock()
 331
 332 #define __part_stat_add(cpu, part, field, addnd)                                \
 333         ((part)->dkstats.field += addnd)
 334
 335 #define part_stat_read(part, field)     ((part)->dkstats.field)
 336
 337 static inline void part_stat_set_all(struct hd_struct *part, int value)
 338 {
 339         memset(&part->dkstats, value, sizeof(struct disk_stats));
 340 }
 341
 342 static inline int init_part_stats(struct hd_struct *part)
 343 {
 344         return 1;
 345 }
 346
 347 static inline void free_part_stats(struct hd_struct *part)
 348 {
 349 }
 350
 351 #endif /* CONFIG_SMP */
 352
 353 #define part_stat_add(cpu, part, field, addnd)  do {                    \
 354         __part_stat_add((cpu), (part), field, addnd);                   \
 355         if ((part)->partno)                                             \
 356                 __part_stat_add((cpu), &part_to_disk((part))->part0,    \
 357                                 field, addnd);                          \
 358 } while (0)
 359
 360 #define part_stat_dec(cpu, gendiskp, field)                             \
 361         part_stat_add(cpu, gendiskp, field, -1)
 362 #define part_stat_inc(cpu, gendiskp, field)                             \
 363         part_stat_add(cpu, gendiskp, field, 1)
 364 #define part_stat_sub(cpu, gendiskp, field, subnd)                      \
 365         part_stat_add(cpu, gendiskp, field, -subnd)
 366
 367 void part_in_flight(struct request_queue *q, struct hd_struct *part,
 368                     unsigned int inflight[2]);
 369 void part_in_flight_rw(struct request_queue *q, struct hd_struct *part,
 370                        unsigned int inflight[2]);
 371 void part_dec_in_flight(struct request_queue *q, struct hd_struct *part,
 372                         int rw);
 373 void part_inc_in_flight(struct request_queue *q, struct hd_struct *part,
 374                         int rw);
 375
 376 static inline struct partition_meta_info *alloc_part_info(struct gendisk *disk)
 377 {
 378         if (disk)
 379                 return kzalloc_node(sizeof(struct partition_meta_info),
 380                                     GFP_KERNEL, disk->node_id);
 381         return kzalloc(sizeof(struct partition_meta_info), GFP_KERNEL);
 382 }
 383
 384 static inline void free_part_info(struct hd_struct *part)
 385 {
 386         kfree(part->info);
 387 }
 388
 389 /* block/blk-core.c */
 390 extern void part_round_stats(struct request_queue *q, int cpu, struct hd_struct *part);
 391
 392 /* block/genhd.c */
 393 extern void device_add_disk(struct device *parent, struct gendisk *disk);
 394 static inline void add_disk(struct gendisk *disk)
 395 {
 396         device_add_disk(NULL, disk);
 397 }
 398
 399 extern void del_gendisk(struct gendisk *gp);
 400 extern struct gendisk *get_gendisk(dev_t dev, int *partno);
 401 extern struct block_device *bdget_disk(struct gendisk *disk, int partno);
 402
 403 extern void set_device_ro(struct block_device *bdev, int flag);
 404 extern void set_disk_ro(struct gendisk *disk, int flag);
 405
 406 static inline int get_disk_ro(struct gendisk *disk)
 407 {
 408         return disk->part0.policy;
 409 }
 410
 411 extern void disk_block_events(struct gendisk *disk);
 412 extern void disk_unblock_events(struct gendisk *disk);
 413 extern void disk_flush_events(struct gendisk *disk, unsigned int mask);
 414 extern unsigned int disk_clear_events(struct gendisk *disk, unsigned int mask);
 415
 416 /* drivers/char/random.c */
 417 extern void add_disk_randomness(struct gendisk *disk) __latent_entropy;
 418 extern void rand_initialize_disk(struct gendisk *disk);
 419
 420 static inline sector_t get_start_sect(struct block_device *bdev)
 421 {
 422         return bdev->bd_part->start_sect;
 423 }
 424 static inline sector_t get_capacity(struct gendisk *disk)
 425 {
 426         return disk->part0.nr_sects;
 427 }
 428 static inline void set_capacity(struct gendisk *disk, sector_t size)
 429 {
 430         disk->part0.nr_sects = size;
 431 }
 432
 433 #ifdef CONFIG_SOLARIS_X86_PARTITION
 434
 435 #define SOLARIS_X86_NUMSLICE    16
 436 #define SOLARIS_X86_VTOC_SANE   (0x600DDEEEUL)
 437
 438 struct solaris_x86_slice {
 439         __le16 s_tag;           /* ID tag of partition */
 440         __le16 s_flag;          /* permission flags */
 441         __le32 s_start;         /* start sector no of partition */
 442         __le32 s_size;          /* # of blocks in partition */
 443 };
 444
 445 struct solaris_x86_vtoc {
 446         unsigned int v_bootinfo[3];     /* info needed by mboot (unsupported) */
 447         __le32 v_sanity;                /* to verify vtoc sanity */
 448         __le32 v_version;               /* layout version */
 449         char    v_volume[8];            /* volume name */
 450         __le16  v_sectorsz;             /* sector size in bytes */
 451         __le16  v_nparts;               /* number of partitions */
 452         unsigned int v_reserved[10];    /* free space */
 453         struct solaris_x86_slice
 454                 v_slice[SOLARIS_X86_NUMSLICE]; /* slice headers */
 455         unsigned int timestamp[SOLARIS_X86_NUMSLICE]; /* timestamp (unsupported) */
 456         char    v_asciilabel[128];      /* for compatibility */
 457 };
 458
 459 #endif /* CONFIG_SOLARIS_X86_PARTITION */
 460
 461 #ifdef CONFIG_BSD_DISKLABEL
 462 /*
 463  * BSD disklabel support by Yossi Gottlieb <yogo@math.tau.ac.il>
 464  * updated by Marc Espie <Marc.Espie@openbsd.org>
 465  */
 466
 467 /* check against BSD src/sys/sys/disklabel.h for consistency */
 468
 469 #define BSD_DISKMAGIC   (0x82564557UL)  /* The disk magic number */
 470 #define BSD_MAXPARTITIONS       16
 471 #define OPENBSD_MAXPARTITIONS   16
 472 #define BSD_FS_UNUSED           0       /* disklabel unused partition entry ID */
 473 struct bsd_disklabel {
 474         __le32  d_magic;                /* the magic number */
 475         __s16   d_type;                 /* drive type */
 476         __s16   d_subtype;              /* controller/d_type specific */
 477         char    d_typename[16];         /* type name, e.g. "eagle" */
 478         char    d_packname[16];                 /* pack identifier */
 479         __u32   d_secsize;              /* # of bytes per sector */
 480         __u32   d_nsectors;             /* # of data sectors per track */
 481         __u32   d_ntracks;              /* # of tracks per cylinder */
 482         __u32   d_ncylinders;           /* # of data cylinders per unit */
 483         __u32   d_secpercyl;            /* # of data sectors per cylinder */
 484         __u32   d_secperunit;           /* # of data sectors per unit */
 485         __u16   d_sparespertrack;       /* # of spare sectors per track */
 486         __u16   d_sparespercyl;         /* # of spare sectors per cylinder */
 487         __u32   d_acylinders;           /* # of alt. cylinders per unit */
 488         __u16   d_rpm;                  /* rotational speed */
 489         __u16   d_interleave;           /* hardware sector interleave */
 490         __u16   d_trackskew;            /* sector 0 skew, per track */
 491         __u16   d_cylskew;              /* sector 0 skew, per cylinder */
 492         __u32   d_headswitch;           /* head switch time, usec */
 493         __u32   d_trkseek;              /* track-to-track seek, usec */
 494         __u32   d_flags;                /* generic flags */
 495 #define NDDATA 5
 496         __u32   d_drivedata[NDDATA];    /* drive-type specific information */
 497 #define NSPARE 5
 498         __u32   d_spare[NSPARE];        /* reserved for future use */
 499         __le32  d_magic2;               /* the magic number (again) */
 500         __le16  d_checksum;             /* xor of data incl. partitions */
 501
 502                         /* filesystem and partition information: */
 503         __le16  d_npartitions;          /* number of partitions in following */
 504         __le32  d_bbsize;               /* size of boot area at sn0, bytes */
 505         __le32  d_sbsize;               /* max size of fs superblock, bytes */
 506         struct  bsd_partition {         /* the partition table */
 507                 __le32  p_size;         /* number of sectors in partition */
 508                 __le32  p_offset;       /* starting sector */
 509                 __le32  p_fsize;        /* filesystem basic fragment size */
 510                 __u8    p_fstype;       /* filesystem type, see below */
 511                 __u8    p_frag;         /* filesystem fragments per block */
 512                 __le16  p_cpg;          /* filesystem cylinders per group */
 513         } d_partitions[BSD_MAXPARTITIONS];      /* actually may be more */
 514 };
 515
 516 #endif  /* CONFIG_BSD_DISKLABEL */
 517
 518 #ifdef CONFIG_UNIXWARE_DISKLABEL
 519 /*
 520  * Unixware slices support by Andrzej Krzysztofowicz <ankry@mif.pg.gda.pl>
 521  * and Krzysztof G. Baranowski <kgb@knm.org.pl>
 522  */
 523
 524 #define UNIXWARE_DISKMAGIC     (0xCA5E600DUL)   /* The disk magic number */
 525 #define UNIXWARE_DISKMAGIC2    (0x600DDEEEUL)   /* The slice table magic nr */
 526 #define UNIXWARE_NUMSLICE      16
 527 #define UNIXWARE_FS_UNUSED     0                /* Unused slice entry ID */
 528
 529 struct unixware_slice {
 530         __le16   s_label;       /* label */
 531         __le16   s_flags;       /* permission flags */
 532         __le32   start_sect;    /* starting sector */
 533         __le32   nr_sects;      /* number of sectors in slice */
 534 };
 535
 536 struct unixware_disklabel {
 537         __le32   d_type;                /* drive type */
 538         __le32   d_magic;                /* the magic number */
 539         __le32   d_version;              /* version number */
 540         char    d_serial[12];           /* serial number of the device */
 541         __le32   d_ncylinders;           /* # of data cylinders per device */
 542         __le32   d_ntracks;              /* # of tracks per cylinder */
 543         __le32   d_nsectors;             /* # of data sectors per track */
 544         __le32   d_secsize;              /* # of bytes per sector */
 545         __le32   d_part_start;           /* # of first sector of this partition */
 546         __le32   d_unknown1[12];         /* ? */
 547         __le32  d_alt_tbl;              /* byte offset of alternate table */
 548         __le32  d_alt_len;              /* byte length of alternate table */
 549         __le32  d_phys_cyl;             /* # of physical cylinders per device */
 550         __le32  d_phys_trk;             /* # of physical tracks per cylinder */
 551         __le32  d_phys_sec;             /* # of physical sectors per track */
 552         __le32  d_phys_bytes;           /* # of physical bytes per sector */
 553         __le32  d_unknown2;             /* ? */
 554         __le32   d_unknown3;             /* ? */
 555         __le32  d_pad[8];               /* pad */
 556
 557         struct unixware_vtoc {
 558                 __le32  v_magic;                /* the magic number */
 559                 __le32  v_version;              /* version number */
 560                 char    v_name[8];              /* volume name */
 561                 __le16  v_nslices;              /* # of slices */
 562                 __le16  v_unknown1;             /* ? */
 563                 __le32  v_reserved[10];         /* reserved */
 564                 struct unixware_slice
 565                         v_slice[UNIXWARE_NUMSLICE];     /* slice headers */
 566         } vtoc;
 567
 568 };  /* 408 */
 569
 570 #endif /* CONFIG_UNIXWARE_DISKLABEL */
 571
 572 #ifdef CONFIG_MINIX_SUBPARTITION
 573 #   define MINIX_NR_SUBPARTITIONS  4
 574 #endif /* CONFIG_MINIX_SUBPARTITION */
 575
 576 #define ADDPART_FLAG_NONE       0
 577 #define ADDPART_FLAG_RAID       1
 578 #define ADDPART_FLAG_WHOLEDISK  2
 579
 580 extern int blk_alloc_devt(struct hd_struct *part, dev_t *devt);
 581 extern void blk_free_devt(dev_t devt);
 582 extern dev_t blk_lookup_devt(const char *name, int partno);
 583 extern char *disk_name (struct gendisk *hd, int partno, char *buf);
 584
 585 extern int disk_expand_part_tbl(struct gendisk *disk, int target);
 586 extern int rescan_partitions(struct gendisk *disk, struct block_device *bdev);
 587 extern int invalidate_partitions(struct gendisk *disk, struct block_device *bdev);
 588 extern struct hd_struct * __must_check add_partition(struct gendisk *disk,
 589                                                      int partno, sector_t start,
 590                                                      sector_t len, int flags,
 591                                                      struct partition_meta_info
 592                                                        *info);
 593 extern void __delete_partition(struct percpu_ref *);
 594 extern void delete_partition(struct gendisk *, int);
 595 extern void printk_all_partitions(void);
 596
 597 extern struct gendisk *alloc_disk_node(int minors, int node_id);
 598 extern struct gendisk *alloc_disk(int minors);
 599 extern struct kobject *get_disk(struct gendisk *disk);
 600 extern void put_disk(struct gendisk *disk);
 601 extern void blk_register_region(dev_t devt, unsigned long range,
 602                         struct module *module,
 603                         struct kobject *(*probe)(dev_t, int *, void *),
 604                         int (*lock)(dev_t, void *),
 605                         void *data);
 606 extern void blk_unregister_region(dev_t devt, unsigned long range);
 607
 608 extern ssize_t part_size_show(struct device *dev,
 609                               struct device_attribute *attr, char *buf);
 610 extern ssize_t part_stat_show(struct device *dev,
 611                               struct device_attribute *attr, char *buf);
 612 extern ssize_t part_inflight_show(struct device *dev,
 613                               struct device_attribute *attr, char *buf);
 614 #ifdef CONFIG_FAIL_MAKE_REQUEST
 615 extern ssize_t part_fail_show(struct device *dev,
 616                               struct device_attribute *attr, char *buf);
 617 extern ssize_t part_fail_store(struct device *dev,
 618                                struct device_attribute *attr,
 619                                const char *buf, size_t count);
 620 #endif /* CONFIG_FAIL_MAKE_REQUEST */
 621
 622 static inline int hd_ref_init(struct hd_struct *part)
 623 {
 624         if (percpu_ref_init(&part->ref, __delete_partition, 0,
 625                                 GFP_KERNEL))
 626                 return -ENOMEM;
 627         return 0;
 628 }
 629
 630 static inline void hd_struct_get(struct hd_struct *part)
 631 {
 632         percpu_ref_get(&part->ref);
 633 }
 634
 635 static inline int hd_struct_try_get(struct hd_struct *part)
 636 {
 637         return percpu_ref_tryget_live(&part->ref);
 638 }
 639
 640 static inline void hd_struct_put(struct hd_struct *part)
 641 {
 642         percpu_ref_put(&part->ref);
 643 }
 644
 645 static inline void hd_struct_kill(struct hd_struct *part)
 646 {
 647         percpu_ref_kill(&part->ref);
 648 }
 649
 650 static inline void hd_free_part(struct hd_struct *part)
 651 {
 652         free_part_stats(part);
 653         free_part_info(part);
 654         percpu_ref_exit(&part->ref);
 655 }
 656
 657 /*
 658  * Any access of part->nr_sects which is not protected by partition
 659  * bd_mutex or gendisk bdev bd_mutex, should be done using this
 660  * accessor function.
 661  *
 662  * Code written along the lines of i_size_read() and i_size_write().
 663  * CONFIG_PREEMPT case optimizes the case of UP kernel with preemption
 664  * on.
 665  */
 666 static inline sector_t part_nr_sects_read(struct hd_struct *part)
 667 {
 668 #if BITS_PER_LONG==32 && defined(CONFIG_LBDAF) && defined(CONFIG_SMP)
 669         sector_t nr_sects;
 670         unsigned seq;
 671         do {
 672                 seq = read_seqcount_begin(&part->nr_sects_seq);
 673                 nr_sects = part->nr_sects;
 674         } while (read_seqcount_retry(&part->nr_sects_seq, seq));
 675         return nr_sects;
 676 #elif BITS_PER_LONG==32 && defined(CONFIG_LBDAF) && defined(CONFIG_PREEMPT)
 677         sector_t nr_sects;
 678
 679         preempt_disable();
 680         nr_sects = part->nr_sects;
 681         preempt_enable();
 682         return nr_sects;
 683 #else
 684         return part->nr_sects;
 685 #endif
 686 }
 687
 688 /*
 689  * Should be called with mutex lock held (typically bd_mutex) of partition
 690  * to provide mutual exlusion among writers otherwise seqcount might be
 691  * left in wrong state leaving the readers spinning infinitely.
 692  */
 693 static inline void part_nr_sects_write(struct hd_struct *part, sector_t size)
 694 {
 695 #if BITS_PER_LONG==32 && defined(CONFIG_LBDAF) && defined(CONFIG_SMP)
 696         write_seqcount_begin(&part->nr_sects_seq);
 697         part->nr_sects = size;
 698         write_seqcount_end(&part->nr_sects_seq);
 699 #elif BITS_PER_LONG==32 && defined(CONFIG_LBDAF) && defined(CONFIG_PREEMPT)
 700         preempt_disable();
 701         part->nr_sects = size;
 702         preempt_enable();
 703 #else
 704         part->nr_sects = size;
 705 #endif
 706 }
 707
 708 #if defined(CONFIG_BLK_DEV_INTEGRITY)
 709 extern void blk_integrity_add(struct gendisk *);
 710 extern void blk_integrity_del(struct gendisk *);
 711 #else   /* CONFIG_BLK_DEV_INTEGRITY */
 712 static inline void blk_integrity_add(struct gendisk *disk) { }
 713 static inline void blk_integrity_del(struct gendisk *disk) { }
 714 #endif  /* CONFIG_BLK_DEV_INTEGRITY */
 715
 716 #else /* CONFIG_BLOCK */
 717
 718 static inline void printk_all_partitions(void) { }
 719
 720 static inline dev_t blk_lookup_devt(const char *name, int partno)
 721 {
 722         dev_t devt = MKDEV(0, 0);
 723         return devt;
 724 }
 725 #endif /* CONFIG_BLOCK */
 726
 727 #endif /* _LINUX_GENHD_H */