LXR linux/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#include <linux/blk_types.h>
  20#include <asm/local.h>
  21
  22#ifdef CONFIG_BLOCK
  23
  24#define dev_to_disk(device)     container_of((device), struct gendisk, part0.__dev)
  25#define dev_to_part(device)     container_of((device), struct hd_struct, __dev)
  26#define disk_to_dev(disk)       (&(disk)->part0.__dev)
  27#define part_to_dev(part)       (&((part)->__dev))
  28
  29extern struct device_type part_type;
  30extern struct kobject *block_depr;
  31extern struct class block_class;
  32
  33enum {
  34/* These three have identical behaviour; use the second one if DOS FDISK gets
  35   confused about extended/logical partitions starting past cylinder 1023. */
  36        DOS_EXTENDED_PARTITION = 5,
  37        LINUX_EXTENDED_PARTITION = 0x85,
  38        WIN98_EXTENDED_PARTITION = 0x0f,
  39
  40        SUN_WHOLE_DISK = DOS_EXTENDED_PARTITION,
  41
  42        LINUX_SWAP_PARTITION = 0x82,
  43        LINUX_DATA_PARTITION = 0x83,
  44        LINUX_LVM_PARTITION = 0x8e,
  45        LINUX_RAID_PARTITION = 0xfd,    /* autodetect RAID partition */
  46
  47        SOLARIS_X86_PARTITION = LINUX_SWAP_PARTITION,
  48        NEW_SOLARIS_X86_PARTITION = 0xbf,
  49
  50        DM6_AUX1PARTITION = 0x51,       /* no DDO:  use xlated geom */
  51        DM6_AUX3PARTITION = 0x53,       /* no DDO:  use xlated geom */
  52        DM6_PARTITION = 0x54,           /* has DDO: use xlated geom & offset */
  53        EZD_PARTITION = 0x55,           /* EZ-DRIVE */
  54
  55        FREEBSD_PARTITION = 0xa5,       /* FreeBSD Partition ID */
  56        OPENBSD_PARTITION = 0xa6,       /* OpenBSD Partition ID */
  57        NETBSD_PARTITION = 0xa9,        /* NetBSD Partition ID */
  58        BSDI_PARTITION = 0xb7,          /* BSDI Partition ID */
  59        MINIX_PARTITION = 0x81,         /* Minix Partition ID */
  60        UNIXWARE_PARTITION = 0x63,      /* Same as GNU_HURD and SCO Unix */
  61};
  62
  63#define DISK_MAX_PARTS                  256
  64#define DISK_NAME_LEN                   32
  65
  66#include <linux/major.h>
  67#include <linux/device.h>
  68#include <linux/smp.h>
  69#include <linux/string.h>
  70#include <linux/fs.h>
  71#include <linux/workqueue.h>
  72
  73struct partition {
  74        unsigned char boot_ind;         /* 0x80 - active */
  75        unsigned char head;             /* starting head */
  76        unsigned char sector;           /* starting sector */
  77        unsigned char cyl;              /* starting cylinder */
  78        unsigned char sys_ind;          /* What partition type */
  79        unsigned char end_head;         /* end head */
  80        unsigned char end_sector;       /* end sector */
  81        unsigned char end_cyl;          /* end cylinder */
  82        __le32 start_sect;      /* starting sector counting from 0 */
  83        __le32 nr_sects;                /* nr of sectors in partition */
  84} __attribute__((packed));
  85
  86struct disk_stats {
  87        u64 nsecs[NR_STAT_GROUPS];
  88        unsigned long sectors[NR_STAT_GROUPS];
  89        unsigned long ios[NR_STAT_GROUPS];
  90        unsigned long merges[NR_STAT_GROUPS];
  91        unsigned long io_ticks;
  92        unsigned long time_in_queue;
  93        local_t in_flight[2];
  94};
  95
  96#define PARTITION_META_INFO_VOLNAMELTH  64
  97/*
  98 * Enough for the string representation of any kind of UUID plus NULL.
  99 * EFI UUID is 36 characters. MSDOS UUID is 11 characters.
 100 */
 101#define PARTITION_META_INFO_UUIDLTH     (UUID_STRING_LEN + 1)
 102
 103struct partition_meta_info {
 104        char uuid[PARTITION_META_INFO_UUIDLTH];
 105        u8 volname[PARTITION_META_INFO_VOLNAMELTH];
 106};
 107
 108struct hd_struct {
 109        sector_t start_sect;
 110        /*
 111         * nr_sects is protected by sequence counter. One might extend a
 112         * partition while IO is happening to it and update of nr_sects
 113         * can be non-atomic on 32bit machines with 64bit sector_t.
 114         */
 115        sector_t nr_sects;
 116        seqcount_t nr_sects_seq;
 117        sector_t alignment_offset;
 118        unsigned int discard_alignment;
 119        struct device __dev;
 120        struct kobject *holder_dir;
 121        int policy, partno;
 122        struct partition_meta_info *info;
 123#ifdef CONFIG_FAIL_MAKE_REQUEST
 124        int make_it_fail;
 125#endif
 126        unsigned long stamp;
 127#ifdef  CONFIG_SMP
 128        struct disk_stats __percpu *dkstats;
 129#else
 130        struct disk_stats dkstats;
 131#endif
 132        struct percpu_ref ref;
 133        struct rcu_work rcu_work;
 134};
 135
 136#define GENHD_FL_REMOVABLE                      1
 137/* 2 is unused */
 138#define GENHD_FL_MEDIA_CHANGE_NOTIFY            4
 139#define GENHD_FL_CD                             8
 140#define GENHD_FL_UP                             16
 141#define GENHD_FL_SUPPRESS_PARTITION_INFO        32
 142#define GENHD_FL_EXT_DEVT                       64 /* allow extended devt */
 143#define GENHD_FL_NATIVE_CAPACITY                128
 144#define GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE     256
 145#define GENHD_FL_NO_PART_SCAN                   512
 146#define GENHD_FL_HIDDEN                         1024
 147
 148enum {
 149        DISK_EVENT_MEDIA_CHANGE                 = 1 << 0, /* media changed */
 150        DISK_EVENT_EJECT_REQUEST                = 1 << 1, /* eject requested */
 151};
 152
 153enum {
 154        /* Poll even if events_poll_msecs is unset */
 155        DISK_EVENT_FLAG_POLL                    = 1 << 0,
 156        /* Forward events to udev */
 157        DISK_EVENT_FLAG_UEVENT                  = 1 << 1,
 158};
 159
 160struct disk_part_tbl {
 161        struct rcu_head rcu_head;
 162        int len;
 163        struct hd_struct __rcu *last_lookup;
 164        struct hd_struct __rcu *part[];
 165};
 166
 167struct disk_events;
 168struct badblocks;
 169
 170#if defined(CONFIG_BLK_DEV_INTEGRITY)
 171
 172struct blk_integrity {
 173        const struct blk_integrity_profile      *profile;
 174        unsigned char                           flags;
 175        unsigned char                           tuple_size;
 176        unsigned char                           interval_exp;
 177        unsigned char                           tag_size;
 178};
 179
 180#endif  /* CONFIG_BLK_DEV_INTEGRITY */
 181
 182struct gendisk {
 183        /* major, first_minor and minors are input parameters only,
 184         * don't use directly.  Use disk_devt() and disk_max_parts().
 185         */
 186        int major;                      /* major number of driver */
 187        int first_minor;
 188        int minors;                     /* maximum number of minors, =1 for
 189                                         * disks that can't be partitioned. */
 190
 191        char disk_name[DISK_NAME_LEN];  /* name of major driver */
 192        char *(*devnode)(struct gendisk *gd, umode_t *mode);
 193
 194        unsigned short events;          /* supported events */
 195        unsigned short event_flags;     /* flags related to event processing */
 196
 197        /* Array of pointers to partitions indexed by partno.
 198         * Protected with matching bdev lock but stat and other
 199         * non-critical accesses use RCU.  Always access through
 200         * helpers.
 201         */
 202        struct disk_part_tbl __rcu *part_tbl;
 203        struct hd_struct part0;
 204
 205        const struct block_device_operations *fops;
 206        struct request_queue *queue;
 207        void *private_data;
 208
 209        int flags;
 210        struct rw_semaphore lookup_sem;
 211        struct kobject *slave_dir;
 212
 213        struct timer_rand_state *random;
 214        atomic_t sync_io;               /* RAID */
 215        struct disk_events *ev;
 216#ifdef  CONFIG_BLK_DEV_INTEGRITY
 217        struct kobject integrity_kobj;
 218#endif  /* CONFIG_BLK_DEV_INTEGRITY */
 219        int node_id;
 220        struct badblocks *bb;
 221        struct lockdep_map lockdep_map;
 222};
 223
 224static inline struct gendisk *part_to_disk(struct hd_struct *part)
 225{
 226        if (likely(part)) {
 227                if (part->partno)
 228                        return dev_to_disk(part_to_dev(part)->parent);
 229                else
 230                        return dev_to_disk(part_to_dev(part));
 231        }
 232        return NULL;
 233}
 234
 235static inline int disk_max_parts(struct gendisk *disk)
 236{
 237        if (disk->flags & GENHD_FL_EXT_DEVT)
 238                return DISK_MAX_PARTS;
 239        return disk->minors;
 240}
 241
 242static inline bool disk_part_scan_enabled(struct gendisk *disk)
 243{
 244        return disk_max_parts(disk) > 1 &&
 245                !(disk->flags & GENHD_FL_NO_PART_SCAN);
 246}
 247
 248static inline dev_t disk_devt(struct gendisk *disk)
 249{
 250        return MKDEV(disk->major, disk->first_minor);
 251}
 252
 253static inline dev_t part_devt(struct hd_struct *part)
 254{
 255        return part_to_dev(part)->devt;
 256}
 257
 258extern struct hd_struct *__disk_get_part(struct gendisk *disk, int partno);
 259extern struct hd_struct *disk_get_part(struct gendisk *disk, int partno);
 260
 261static inline void disk_put_part(struct hd_struct *part)
 262{
 263        if (likely(part))
 264                put_device(part_to_dev(part));
 265}
 266
 267/*
 268 * Smarter partition iterator without context limits.
 269 */
 270#define DISK_PITER_REVERSE      (1 << 0) /* iterate in the reverse direction */
 271#define DISK_PITER_INCL_EMPTY   (1 << 1) /* include 0-sized parts */
 272#define DISK_PITER_INCL_PART0   (1 << 2) /* include partition 0 */
 273#define DISK_PITER_INCL_EMPTY_PART0 (1 << 3) /* include empty partition 0 */
 274
 275struct disk_part_iter {
 276        struct gendisk          *disk;
 277        struct hd_struct        *part;
 278        int                     idx;
 279        unsigned int            flags;
 280};
 281
 282extern void disk_part_iter_init(struct disk_part_iter *piter,
 283                                 struct gendisk *disk, unsigned int flags);
 284extern struct hd_struct *disk_part_iter_next(struct disk_part_iter *piter);
 285extern void disk_part_iter_exit(struct disk_part_iter *piter);
 286
 287extern struct hd_struct *disk_map_sector_rcu(struct gendisk *disk,
 288                                             sector_t sector);
 289
 290/*
 291 * Macros to operate on percpu disk statistics:
 292 *
 293 * {disk|part|all}_stat_{add|sub|inc|dec}() modify the stat counters
 294 * and should be called between disk_stat_lock() and
 295 * disk_stat_unlock().
 296 *
 297 * part_stat_read() can be called at any time.
 298 *
 299 * part_stat_{add|set_all}() and {init|free}_part_stats are for
 300 * internal use only.
 301 */
 302#ifdef  CONFIG_SMP
 303#define part_stat_lock()        ({ rcu_read_lock(); get_cpu(); })
 304#define part_stat_unlock()      do { put_cpu(); rcu_read_unlock(); } while (0)
 305
 306#define part_stat_get_cpu(part, field, cpu)                                     \
 307        (per_cpu_ptr((part)->dkstats, (cpu))->field)
 308
 309#define part_stat_get(part, field)                                      \
 310        part_stat_get_cpu(part, field, smp_processor_id())
 311
 312#define part_stat_read(part, field)                                     \
 313({                                                                      \
 314        typeof((part)->dkstats->field) res = 0;                         \
 315        unsigned int _cpu;                                              \
 316        for_each_possible_cpu(_cpu)                                     \
 317                res += per_cpu_ptr((part)->dkstats, _cpu)->field;       \
 318        res;                                                            \
 319})
 320
 321static inline void part_stat_set_all(struct hd_struct *part, int value)
 322{
 323        int i;
 324
 325        for_each_possible_cpu(i)
 326                memset(per_cpu_ptr(part->dkstats, i), value,
 327                                sizeof(struct disk_stats));
 328}
 329
 330static inline int init_part_stats(struct hd_struct *part)
 331{
 332        part->dkstats = alloc_percpu(struct disk_stats);
 333        if (!part->dkstats)
 334                return 0;
 335        return 1;
 336}
 337
 338static inline void free_part_stats(struct hd_struct *part)
 339{
 340        free_percpu(part->dkstats);
 341}
 342
 343#else /* !CONFIG_SMP */
 344#define part_stat_lock()        ({ rcu_read_lock(); 0; })
 345#define part_stat_unlock()      rcu_read_unlock()
 346
 347#define part_stat_get(part, field)              ((part)->dkstats.field)
 348#define part_stat_get_cpu(part, field, cpu)     part_stat_get(part, field)
 349#define part_stat_read(part, field)             part_stat_get(part, field)
 350
 351static inline void part_stat_set_all(struct hd_struct *part, int value)
 352{
 353        memset(&part->dkstats, value, sizeof(struct disk_stats));
 354}
 355
 356static inline int init_part_stats(struct hd_struct *part)
 357{
 358        return 1;
 359}
 360
 361static inline void free_part_stats(struct hd_struct *part)
 362{
 363}
 364
 365#endif /* CONFIG_SMP */
 366
 367#define part_stat_read_msecs(part, which)                               \
 368        div_u64(part_stat_read(part, nsecs[which]), NSEC_PER_MSEC)
 369
 370#define part_stat_read_accum(part, field)                               \
 371        (part_stat_read(part, field[STAT_READ]) +                       \
 372         part_stat_read(part, field[STAT_WRITE]) +                      \
 373         part_stat_read(part, field[STAT_DISCARD]))
 374
 375#define __part_stat_add(part, field, addnd)                             \
 376        (part_stat_get(part, field) += (addnd))
 377
 378#define part_stat_add(part, field, addnd)       do {                    \
 379        __part_stat_add((part), field, addnd);                          \
 380        if ((part)->partno)                                             \
 381                __part_stat_add(&part_to_disk((part))->part0,           \
 382                                field, addnd);                          \
 383} while (0)
 384
 385#define part_stat_dec(gendiskp, field)                                  \
 386        part_stat_add(gendiskp, field, -1)
 387#define part_stat_inc(gendiskp, field)                                  \
 388        part_stat_add(gendiskp, field, 1)
 389#define part_stat_sub(gendiskp, field, subnd)                           \
 390        part_stat_add(gendiskp, field, -subnd)
 391
 392#define part_stat_local_dec(gendiskp, field)                            \
 393        local_dec(&(part_stat_get(gendiskp, field)))
 394#define part_stat_local_inc(gendiskp, field)                            \
 395        local_inc(&(part_stat_get(gendiskp, field)))
 396#define part_stat_local_read(gendiskp, field)                           \
 397        local_read(&(part_stat_get(gendiskp, field)))
 398#define part_stat_local_read_cpu(gendiskp, field, cpu)                  \
 399        local_read(&(part_stat_get_cpu(gendiskp, field, cpu)))
 400
 401unsigned int part_in_flight(struct request_queue *q, struct hd_struct *part);
 402void part_in_flight_rw(struct request_queue *q, struct hd_struct *part,
 403                       unsigned int inflight[2]);
 404void part_dec_in_flight(struct request_queue *q, struct hd_struct *part,
 405                        int rw);
 406void part_inc_in_flight(struct request_queue *q, struct hd_struct *part,
 407                        int rw);
 408
 409static inline struct partition_meta_info *alloc_part_info(struct gendisk *disk)
 410{
 411        if (disk)
 412                return kzalloc_node(sizeof(struct partition_meta_info),
 413                                    GFP_KERNEL, disk->node_id);
 414        return kzalloc(sizeof(struct partition_meta_info), GFP_KERNEL);
 415}
 416
 417static inline void free_part_info(struct hd_struct *part)
 418{
 419        kfree(part->info);
 420}
 421
 422void update_io_ticks(struct hd_struct *part, unsigned long now);
 423
 424/* block/genhd.c */
 425extern void device_add_disk(struct device *parent, struct gendisk *disk,
 426                            const struct attribute_group **groups);
 427static inline void add_disk(struct gendisk *disk)
 428{
 429        device_add_disk(NULL, disk, NULL);
 430}
 431extern void device_add_disk_no_queue_reg(struct device *parent, struct gendisk *disk);
 432static inline void add_disk_no_queue_reg(struct gendisk *disk)
 433{
 434        device_add_disk_no_queue_reg(NULL, disk);
 435}
 436
 437extern void del_gendisk(struct gendisk *gp);
 438extern struct gendisk *get_gendisk(dev_t dev, int *partno);
 439extern struct block_device *bdget_disk(struct gendisk *disk, int partno);
 440
 441extern void set_device_ro(struct block_device *bdev, int flag);
 442extern void set_disk_ro(struct gendisk *disk, int flag);
 443
 444static inline int get_disk_ro(struct gendisk *disk)
 445{
 446        return disk->part0.policy;
 447}
 448
 449extern void disk_block_events(struct gendisk *disk);
 450extern void disk_unblock_events(struct gendisk *disk);
 451extern void disk_flush_events(struct gendisk *disk, unsigned int mask);
 452extern unsigned int disk_clear_events(struct gendisk *disk, unsigned int mask);
 453
 454/* drivers/char/random.c */
 455extern void add_disk_randomness(struct gendisk *disk) __latent_entropy;
 456extern void rand_initialize_disk(struct gendisk *disk);
 457
 458static inline sector_t get_start_sect(struct block_device *bdev)
 459{
 460        return bdev->bd_part->start_sect;
 461}
 462static inline sector_t get_capacity(struct gendisk *disk)
 463{
 464        return disk->part0.nr_sects;
 465}
 466static inline void set_capacity(struct gendisk *disk, sector_t size)
 467{
 468        disk->part0.nr_sects = size;
 469}
 470
 471#ifdef CONFIG_SOLARIS_X86_PARTITION
 472
 473#define SOLARIS_X86_NUMSLICE    16
 474#define SOLARIS_X86_VTOC_SANE   (0x600DDEEEUL)
 475
 476struct solaris_x86_slice {
 477        __le16 s_tag;           /* ID tag of partition */
 478        __le16 s_flag;          /* permission flags */
 479        __le32 s_start;         /* start sector no of partition */
 480        __le32 s_size;          /* # of blocks in partition */
 481};
 482
 483struct solaris_x86_vtoc {
 484        unsigned int v_bootinfo[3];     /* info needed by mboot (unsupported) */
 485        __le32 v_sanity;                /* to verify vtoc sanity */
 486        __le32 v_version;               /* layout version */
 487        char    v_volume[8];            /* volume name */
 488        __le16  v_sectorsz;             /* sector size in bytes */
 489        __le16  v_nparts;               /* number of partitions */
 490        unsigned int v_reserved[10];    /* free space */
 491        struct solaris_x86_slice
 492                v_slice[SOLARIS_X86_NUMSLICE]; /* slice headers */
 493        unsigned int timestamp[SOLARIS_X86_NUMSLICE]; /* timestamp (unsupported) */
 494        char    v_asciilabel[128];      /* for compatibility */
 495};
 496
 497#endif /* CONFIG_SOLARIS_X86_PARTITION */
 498
 499#ifdef CONFIG_BSD_DISKLABEL
 500/*
 501 * BSD disklabel support by Yossi Gottlieb <yogo@math.tau.ac.il>
 502 * updated by Marc Espie <Marc.Espie@openbsd.org>
 503 */
 504
 505/* check against BSD src/sys/sys/disklabel.h for consistency */
 506
 507#define BSD_DISKMAGIC   (0x82564557UL)  /* The disk magic number */
 508#define BSD_MAXPARTITIONS       16
 509#define OPENBSD_MAXPARTITIONS   16
 510#define BSD_FS_UNUSED           0       /* disklabel unused partition entry ID */
 511struct bsd_disklabel {
 512        __le32  d_magic;                /* the magic number */
 513        __s16   d_type;                 /* drive type */
 514        __s16   d_subtype;              /* controller/d_type specific */
 515        char    d_typename[16];         /* type name, e.g. "eagle" */
 516        char    d_packname[16];                 /* pack identifier */ 
 517        __u32   d_secsize;              /* # of bytes per sector */
 518        __u32   d_nsectors;             /* # of data sectors per track */
 519        __u32   d_ntracks;              /* # of tracks per cylinder */
 520        __u32   d_ncylinders;           /* # of data cylinders per unit */
 521        __u32   d_secpercyl;            /* # of data sectors per cylinder */
 522        __u32   d_secperunit;           /* # of data sectors per unit */
 523        __u16   d_sparespertrack;       /* # of spare sectors per track */
 524        __u16   d_sparespercyl;         /* # of spare sectors per cylinder */
 525        __u32   d_acylinders;           /* # of alt. cylinders per unit */
 526        __u16   d_rpm;                  /* rotational speed */
 527        __u16   d_interleave;           /* hardware sector interleave */
 528        __u16   d_trackskew;            /* sector 0 skew, per track */
 529        __u16   d_cylskew;              /* sector 0 skew, per cylinder */
 530        __u32   d_headswitch;           /* head switch time, usec */
 531        __u32   d_trkseek;              /* track-to-track seek, usec */
 532        __u32   d_flags;                /* generic flags */
 533#define NDDATA 5
 534        __u32   d_drivedata[NDDATA];    /* drive-type specific information */
 535#define NSPARE 5
 536        __u32   d_spare[NSPARE];        /* reserved for future use */
 537        __le32  d_magic2;               /* the magic number (again) */
 538        __le16  d_checksum;             /* xor of data incl. partitions */
 539
 540                        /* filesystem and partition information: */
 541        __le16  d_npartitions;          /* number of partitions in following */
 542        __le32  d_bbsize;               /* size of boot area at sn0, bytes */
 543        __le32  d_sbsize;               /* max size of fs superblock, bytes */
 544        struct  bsd_partition {         /* the partition table */
 545                __le32  p_size;         /* number of sectors in partition */
 546                __le32  p_offset;       /* starting sector */
 547                __le32  p_fsize;        /* filesystem basic fragment size */
 548                __u8    p_fstype;       /* filesystem type, see below */
 549                __u8    p_frag;         /* filesystem fragments per block */
 550                __le16  p_cpg;          /* filesystem cylinders per group */
 551        } d_partitions[BSD_MAXPARTITIONS];      /* actually may be more */
 552};
 553
 554#endif  /* CONFIG_BSD_DISKLABEL */
 555
 556#ifdef CONFIG_UNIXWARE_DISKLABEL
 557/*
 558 * Unixware slices support by Andrzej Krzysztofowicz <ankry@mif.pg.gda.pl>
 559 * and Krzysztof G. Baranowski <kgb@knm.org.pl>
 560 */
 561
 562#define UNIXWARE_DISKMAGIC     (0xCA5E600DUL)   /* The disk magic number */
 563#define UNIXWARE_DISKMAGIC2    (0x600DDEEEUL)   /* The slice table magic nr */
 564#define UNIXWARE_NUMSLICE      16
 565#define UNIXWARE_FS_UNUSED     0                /* Unused slice entry ID */
 566
 567struct unixware_slice {
 568        __le16   s_label;       /* label */
 569        __le16   s_flags;       /* permission flags */
 570        __le32   start_sect;    /* starting sector */
 571        __le32   nr_sects;      /* number of sectors in slice */
 572};
 573
 574struct unixware_disklabel {
 575        __le32   d_type;                /* drive type */
 576        __le32   d_magic;                /* the magic number */
 577        __le32   d_version;              /* version number */
 578        char    d_serial[12];           /* serial number of the device */
 579        __le32   d_ncylinders;           /* # of data cylinders per device */
 580        __le32   d_ntracks;              /* # of tracks per cylinder */
 581        __le32   d_nsectors;             /* # of data sectors per track */
 582        __le32   d_secsize;              /* # of bytes per sector */
 583        __le32   d_part_start;           /* # of first sector of this partition */
 584        __le32   d_unknown1[12];         /* ? */
 585        __le32  d_alt_tbl;              /* byte offset of alternate table */
 586        __le32  d_alt_len;              /* byte length of alternate table */
 587        __le32  d_phys_cyl;             /* # of physical cylinders per device */
 588        __le32  d_phys_trk;             /* # of physical tracks per cylinder */
 589        __le32  d_phys_sec;             /* # of physical sectors per track */
 590        __le32  d_phys_bytes;           /* # of physical bytes per sector */
 591        __le32  d_unknown2;             /* ? */
 592        __le32   d_unknown3;             /* ? */
 593        __le32  d_pad[8];               /* pad */
 594
 595        struct unixware_vtoc {
 596                __le32  v_magic;                /* the magic number */
 597                __le32  v_version;              /* version number */
 598                char    v_name[8];              /* volume name */
 599                __le16  v_nslices;              /* # of slices */
 600                __le16  v_unknown1;             /* ? */
 601                __le32  v_reserved[10];         /* reserved */
 602                struct unixware_slice
 603                        v_slice[UNIXWARE_NUMSLICE];     /* slice headers */
 604        } vtoc;
 605
 606};  /* 408 */
 607
 608#endif /* CONFIG_UNIXWARE_DISKLABEL */
 609
 610#ifdef CONFIG_MINIX_SUBPARTITION
 611#   define MINIX_NR_SUBPARTITIONS  4
 612#endif /* CONFIG_MINIX_SUBPARTITION */
 613
 614#define ADDPART_FLAG_NONE       0
 615#define ADDPART_FLAG_RAID       1
 616#define ADDPART_FLAG_WHOLEDISK  2
 617
 618extern int blk_alloc_devt(struct hd_struct *part, dev_t *devt);
 619extern void blk_free_devt(dev_t devt);
 620extern void blk_invalidate_devt(dev_t devt);
 621extern dev_t blk_lookup_devt(const char *name, int partno);
 622extern char *disk_name (struct gendisk *hd, int partno, char *buf);
 623
 624extern int disk_expand_part_tbl(struct gendisk *disk, int target);
 625extern int rescan_partitions(struct gendisk *disk, struct block_device *bdev);
 626extern int invalidate_partitions(struct gendisk *disk, struct block_device *bdev);
 627extern struct hd_struct * __must_check add_partition(struct gendisk *disk,
 628                                                     int partno, sector_t start,
 629                                                     sector_t len, int flags,
 630                                                     struct partition_meta_info
 631                                                       *info);
 632extern void __delete_partition(struct percpu_ref *);
 633extern void delete_partition(struct gendisk *, int);
 634extern void printk_all_partitions(void);
 635
 636extern struct gendisk *__alloc_disk_node(int minors, int node_id);
 637extern struct kobject *get_disk_and_module(struct gendisk *disk);
 638extern void put_disk(struct gendisk *disk);
 639extern void put_disk_and_module(struct gendisk *disk);
 640extern void blk_register_region(dev_t devt, unsigned long range,
 641                        struct module *module,
 642                        struct kobject *(*probe)(dev_t, int *, void *),
 643                        int (*lock)(dev_t, void *),
 644                        void *data);
 645extern void blk_unregister_region(dev_t devt, unsigned long range);
 646
 647extern ssize_t part_size_show(struct device *dev,
 648                              struct device_attribute *attr, char *buf);
 649extern ssize_t part_stat_show(struct device *dev,
 650                              struct device_attribute *attr, char *buf);
 651extern ssize_t part_inflight_show(struct device *dev,
 652                              struct device_attribute *attr, char *buf);
 653#ifdef CONFIG_FAIL_MAKE_REQUEST
 654extern ssize_t part_fail_show(struct device *dev,
 655                              struct device_attribute *attr, char *buf);
 656extern ssize_t part_fail_store(struct device *dev,
 657                               struct device_attribute *attr,
 658                               const char *buf, size_t count);
 659#endif /* CONFIG_FAIL_MAKE_REQUEST */
 660
 661#define alloc_disk_node(minors, node_id)                                \
 662({                                                                      \
 663        static struct lock_class_key __key;                             \
 664        const char *__name;                                             \
 665        struct gendisk *__disk;                                         \
 666                                                                        \
 667        __name = "(gendisk_completion)"#minors"("#node_id")";           \
 668                                                                        \
 669        __disk = __alloc_disk_node(minors, node_id);                    \
 670                                                                        \
 671        if (__disk)                                                     \
 672                lockdep_init_map(&__disk->lockdep_map, __name, &__key, 0); \
 673                                                                        \
 674        __disk;                                                         \
 675})
 676
 677#define alloc_disk(minors) alloc_disk_node(minors, NUMA_NO_NODE)
 678
 679static inline int hd_ref_init(struct hd_struct *part)
 680{
 681        if (percpu_ref_init(&part->ref, __delete_partition, 0,
 682                                GFP_KERNEL))
 683                return -ENOMEM;
 684        return 0;
 685}
 686
 687static inline void hd_struct_get(struct hd_struct *part)
 688{
 689        percpu_ref_get(&part->ref);
 690}
 691
 692static inline int hd_struct_try_get(struct hd_struct *part)
 693{
 694        return percpu_ref_tryget_live(&part->ref);
 695}
 696
 697static inline void hd_struct_put(struct hd_struct *part)
 698{
 699        percpu_ref_put(&part->ref);
 700}
 701
 702static inline void hd_struct_kill(struct hd_struct *part)
 703{
 704        percpu_ref_kill(&part->ref);
 705}
 706
 707static inline void hd_free_part(struct hd_struct *part)
 708{
 709        free_part_stats(part);
 710        free_part_info(part);
 711        percpu_ref_exit(&part->ref);
 712}
 713
 714/*
 715 * Any access of part->nr_sects which is not protected by partition
 716 * bd_mutex or gendisk bdev bd_mutex, should be done using this
 717 * accessor function.
 718 *
 719 * Code written along the lines of i_size_read() and i_size_write().
 720 * CONFIG_PREEMPT case optimizes the case of UP kernel with preemption
 721 * on.
 722 */
 723static inline sector_t part_nr_sects_read(struct hd_struct *part)
 724{
 725#if BITS_PER_LONG==32 && defined(CONFIG_SMP)
 726        sector_t nr_sects;
 727        unsigned seq;
 728        do {
 729                seq = read_seqcount_begin(&part->nr_sects_seq);
 730                nr_sects = part->nr_sects;
 731        } while (read_seqcount_retry(&part->nr_sects_seq, seq));
 732        return nr_sects;
 733#elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPT)
 734        sector_t nr_sects;
 735
 736        preempt_disable();
 737        nr_sects = part->nr_sects;
 738        preempt_enable();
 739        return nr_sects;
 740#else
 741        return part->nr_sects;
 742#endif
 743}
 744
 745/*
 746 * Should be called with mutex lock held (typically bd_mutex) of partition
 747 * to provide mutual exlusion among writers otherwise seqcount might be
 748 * left in wrong state leaving the readers spinning infinitely.
 749 */
 750static inline void part_nr_sects_write(struct hd_struct *part, sector_t size)
 751{
 752#if BITS_PER_LONG==32 && defined(CONFIG_SMP)
 753        write_seqcount_begin(&part->nr_sects_seq);
 754        part->nr_sects = size;
 755        write_seqcount_end(&part->nr_sects_seq);
 756#elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPT)
 757        preempt_disable();
 758        part->nr_sects = size;
 759        preempt_enable();
 760#else
 761        part->nr_sects = size;
 762#endif
 763}
 764
 765#if defined(CONFIG_BLK_DEV_INTEGRITY)
 766extern void blk_integrity_add(struct gendisk *);
 767extern void blk_integrity_del(struct gendisk *);
 768#else   /* CONFIG_BLK_DEV_INTEGRITY */
 769static inline void blk_integrity_add(struct gendisk *disk) { }
 770static inline void blk_integrity_del(struct gendisk *disk) { }
 771#endif  /* CONFIG_BLK_DEV_INTEGRITY */
 772
 773#else /* CONFIG_BLOCK */
 774
 775static inline void printk_all_partitions(void) { }
 776
 777static inline dev_t blk_lookup_devt(const char *name, int partno)
 778{
 779        dev_t devt = MKDEV(0, 0);
 780        return devt;
 781}
 782#endif /* CONFIG_BLOCK */
 783
 784#endif /* _LINUX_GENHD_H */
 785