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
  22extern const struct device_type disk_type;
  23extern struct device_type part_type;
  24extern struct class block_class;
  25
  26#define DISK_MAX_PARTS                  256
  27#define DISK_NAME_LEN                   32
  28
  29#include <linux/major.h>
  30#include <linux/device.h>
  31#include <linux/smp.h>
  32#include <linux/string.h>
  33#include <linux/fs.h>
  34#include <linux/workqueue.h>
  35#include <linux/xarray.h>
  36
  37#define PARTITION_META_INFO_VOLNAMELTH  64
  38/*
  39 * Enough for the string representation of any kind of UUID plus NULL.
  40 * EFI UUID is 36 characters. MSDOS UUID is 11 characters.
  41 */
  42#define PARTITION_META_INFO_UUIDLTH     (UUID_STRING_LEN + 1)
  43
  44struct partition_meta_info {
  45        char uuid[PARTITION_META_INFO_UUIDLTH];
  46        u8 volname[PARTITION_META_INFO_VOLNAMELTH];
  47};
  48
  49/**
  50 * DOC: genhd capability flags
  51 *
  52 * ``GENHD_FL_REMOVABLE`` (0x0001): indicates that the block device
  53 * gives access to removable media.
  54 * When set, the device remains present even when media is not
  55 * inserted.
  56 * Must not be set for devices which are removed entirely when the
  57 * media is removed.
  58 *
  59 * ``GENHD_FL_CD`` (0x0008): the block device is a CD-ROM-style
  60 * device.
  61 * Affects responses to the ``CDROM_GET_CAPABILITY`` ioctl.
  62 *
  63 * ``GENHD_FL_SUPPRESS_PARTITION_INFO`` (0x0020): don't include
  64 * partition information in ``/proc/partitions`` or in the output of
  65 * printk_all_partitions().
  66 * Used for the null block device and some MMC devices.
  67 *
  68 * ``GENHD_FL_EXT_DEVT`` (0x0040): the driver supports extended
  69 * dynamic ``dev_t``, i.e. it wants extended device numbers
  70 * (``BLOCK_EXT_MAJOR``).
  71 * This affects the maximum number of partitions.
  72 *
  73 * ``GENHD_FL_NATIVE_CAPACITY`` (0x0080): based on information in the
  74 * partition table, the device's capacity has been extended to its
  75 * native capacity; i.e. the device has hidden capacity used by one
  76 * of the partitions (this is a flag used so that native capacity is
  77 * only ever unlocked once).
  78 *
  79 * ``GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE`` (0x0100): event polling is
  80 * blocked whenever a writer holds an exclusive lock.
  81 *
  82 * ``GENHD_FL_NO_PART_SCAN`` (0x0200): partition scanning is disabled.
  83 * Used for loop devices in their default settings and some MMC
  84 * devices.
  85 *
  86 * ``GENHD_FL_HIDDEN`` (0x0400): the block device is hidden; it
  87 * doesn't produce events, doesn't appear in sysfs, and doesn't have
  88 * an associated ``bdev``.
  89 * Implies ``GENHD_FL_SUPPRESS_PARTITION_INFO`` and
  90 * ``GENHD_FL_NO_PART_SCAN``.
  91 * Used for multipath devices.
  92 */
  93#define GENHD_FL_REMOVABLE                      0x0001
  94/* 2 is unused (used to be GENHD_FL_DRIVERFS) */
  95/* 4 is unused (used to be GENHD_FL_MEDIA_CHANGE_NOTIFY) */
  96#define GENHD_FL_CD                             0x0008
  97#define GENHD_FL_SUPPRESS_PARTITION_INFO        0x0020
  98#define GENHD_FL_EXT_DEVT                       0x0040
  99#define GENHD_FL_NATIVE_CAPACITY                0x0080
 100#define GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE     0x0100
 101#define GENHD_FL_NO_PART_SCAN                   0x0200
 102#define GENHD_FL_HIDDEN                         0x0400
 103
 104enum {
 105        DISK_EVENT_MEDIA_CHANGE                 = 1 << 0, /* media changed */
 106        DISK_EVENT_EJECT_REQUEST                = 1 << 1, /* eject requested */
 107};
 108
 109enum {
 110        /* Poll even if events_poll_msecs is unset */
 111        DISK_EVENT_FLAG_POLL                    = 1 << 0,
 112        /* Forward events to udev */
 113        DISK_EVENT_FLAG_UEVENT                  = 1 << 1,
 114};
 115
 116struct disk_events;
 117struct badblocks;
 118
 119struct blk_integrity {
 120        const struct blk_integrity_profile      *profile;
 121        unsigned char                           flags;
 122        unsigned char                           tuple_size;
 123        unsigned char                           interval_exp;
 124        unsigned char                           tag_size;
 125};
 126
 127struct gendisk {
 128        /* major, first_minor and minors are input parameters only,
 129         * don't use directly.  Use disk_devt() and disk_max_parts().
 130         */
 131        int major;                      /* major number of driver */
 132        int first_minor;
 133        int minors;                     /* maximum number of minors, =1 for
 134                                         * disks that can't be partitioned. */
 135
 136        char disk_name[DISK_NAME_LEN];  /* name of major driver */
 137
 138        unsigned short events;          /* supported events */
 139        unsigned short event_flags;     /* flags related to event processing */
 140
 141        struct xarray part_tbl;
 142        struct block_device *part0;
 143
 144        const struct block_device_operations *fops;
 145        struct request_queue *queue;
 146        void *private_data;
 147
 148        int flags;
 149        unsigned long state;
 150#define GD_NEED_PART_SCAN               0
 151#define GD_READ_ONLY                    1
 152#define GD_DEAD                         2
 153
 154        struct mutex open_mutex;        /* open/close mutex */
 155        unsigned open_partitions;       /* number of open partitions */
 156
 157        struct backing_dev_info *bdi;
 158        struct kobject *slave_dir;
 159#ifdef CONFIG_BLOCK_HOLDER_DEPRECATED
 160        struct list_head slave_bdevs;
 161#endif
 162        struct timer_rand_state *random;
 163        atomic_t sync_io;               /* RAID */
 164        struct disk_events *ev;
 165#ifdef  CONFIG_BLK_DEV_INTEGRITY
 166        struct kobject integrity_kobj;
 167#endif  /* CONFIG_BLK_DEV_INTEGRITY */
 168#if IS_ENABLED(CONFIG_CDROM)
 169        struct cdrom_device_info *cdi;
 170#endif
 171        int node_id;
 172        struct badblocks *bb;
 173        struct lockdep_map lockdep_map;
 174        u64 diskseq;
 175};
 176
 177static inline bool disk_live(struct gendisk *disk)
 178{
 179        return !inode_unhashed(disk->part0->bd_inode);
 180}
 181
 182/*
 183 * The gendisk is refcounted by the part0 block_device, and the bd_device
 184 * therein is also used for device model presentation in sysfs.
 185 */
 186#define dev_to_disk(device) \
 187        (dev_to_bdev(device)->bd_disk)
 188#define disk_to_dev(disk) \
 189        (&((disk)->part0->bd_device))
 190
 191#if IS_REACHABLE(CONFIG_CDROM)
 192#define disk_to_cdi(disk)       ((disk)->cdi)
 193#else
 194#define disk_to_cdi(disk)       NULL
 195#endif
 196
 197static inline int disk_max_parts(struct gendisk *disk)
 198{
 199        if (disk->flags & GENHD_FL_EXT_DEVT)
 200                return DISK_MAX_PARTS;
 201        return disk->minors;
 202}
 203
 204static inline bool disk_part_scan_enabled(struct gendisk *disk)
 205{
 206        return disk_max_parts(disk) > 1 &&
 207                !(disk->flags & GENHD_FL_NO_PART_SCAN);
 208}
 209
 210static inline dev_t disk_devt(struct gendisk *disk)
 211{
 212        return MKDEV(disk->major, disk->first_minor);
 213}
 214
 215void disk_uevent(struct gendisk *disk, enum kobject_action action);
 216
 217/* block/genhd.c */
 218int device_add_disk(struct device *parent, struct gendisk *disk,
 219                const struct attribute_group **groups);
 220static inline int add_disk(struct gendisk *disk)
 221{
 222        return device_add_disk(NULL, disk, NULL);
 223}
 224extern void del_gendisk(struct gendisk *gp);
 225
 226void set_disk_ro(struct gendisk *disk, bool read_only);
 227
 228static inline int get_disk_ro(struct gendisk *disk)
 229{
 230        return disk->part0->bd_read_only ||
 231                test_bit(GD_READ_ONLY, &disk->state);
 232}
 233
 234extern void disk_block_events(struct gendisk *disk);
 235extern void disk_unblock_events(struct gendisk *disk);
 236extern void disk_flush_events(struct gendisk *disk, unsigned int mask);
 237bool set_capacity_and_notify(struct gendisk *disk, sector_t size);
 238bool disk_force_media_change(struct gendisk *disk, unsigned int events);
 239
 240/* drivers/char/random.c */
 241extern void add_disk_randomness(struct gendisk *disk) __latent_entropy;
 242extern void rand_initialize_disk(struct gendisk *disk);
 243
 244static inline sector_t get_start_sect(struct block_device *bdev)
 245{
 246        return bdev->bd_start_sect;
 247}
 248
 249static inline sector_t bdev_nr_sectors(struct block_device *bdev)
 250{
 251        return i_size_read(bdev->bd_inode) >> 9;
 252}
 253
 254static inline sector_t get_capacity(struct gendisk *disk)
 255{
 256        return bdev_nr_sectors(disk->part0);
 257}
 258
 259int bdev_disk_changed(struct gendisk *disk, bool invalidate);
 260void blk_drop_partitions(struct gendisk *disk);
 261
 262struct gendisk *__alloc_disk_node(struct request_queue *q, int node_id,
 263                struct lock_class_key *lkclass);
 264extern void put_disk(struct gendisk *disk);
 265struct gendisk *__blk_alloc_disk(int node, struct lock_class_key *lkclass);
 266
 267/**
 268 * blk_alloc_disk - allocate a gendisk structure
 269 * @node_id: numa node to allocate on
 270 *
 271 * Allocate and pre-initialize a gendisk structure for use with BIO based
 272 * drivers.
 273 *
 274 * Context: can sleep
 275 */
 276#define blk_alloc_disk(node_id)                                         \
 277({                                                                      \
 278        static struct lock_class_key __key;                             \
 279                                                                        \
 280        __blk_alloc_disk(node_id, &__key);                              \
 281})
 282void blk_cleanup_disk(struct gendisk *disk);
 283
 284int __register_blkdev(unsigned int major, const char *name,
 285                void (*probe)(dev_t devt));
 286#define register_blkdev(major, name) \
 287        __register_blkdev(major, name, NULL)
 288void unregister_blkdev(unsigned int major, const char *name);
 289
 290bool bdev_check_media_change(struct block_device *bdev);
 291int __invalidate_device(struct block_device *bdev, bool kill_dirty);
 292void set_capacity(struct gendisk *disk, sector_t size);
 293
 294/* for drivers/char/raw.c: */
 295int blkdev_ioctl(struct block_device *, fmode_t, unsigned, unsigned long);
 296long compat_blkdev_ioctl(struct file *, unsigned, unsigned long);
 297
 298#ifdef CONFIG_BLOCK_HOLDER_DEPRECATED
 299int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk);
 300void bd_unlink_disk_holder(struct block_device *bdev, struct gendisk *disk);
 301int bd_register_pending_holders(struct gendisk *disk);
 302#else
 303static inline int bd_link_disk_holder(struct block_device *bdev,
 304                                      struct gendisk *disk)
 305{
 306        return 0;
 307}
 308static inline void bd_unlink_disk_holder(struct block_device *bdev,
 309                                         struct gendisk *disk)
 310{
 311}
 312static inline int bd_register_pending_holders(struct gendisk *disk)
 313{
 314        return 0;
 315}
 316#endif /* CONFIG_BLOCK_HOLDER_DEPRECATED */
 317
 318dev_t part_devt(struct gendisk *disk, u8 partno);
 319void inc_diskseq(struct gendisk *disk);
 320dev_t blk_lookup_devt(const char *name, int partno);
 321void blk_request_module(dev_t devt);
 322#ifdef CONFIG_BLOCK
 323void printk_all_partitions(void);
 324#else /* CONFIG_BLOCK */
 325static inline void printk_all_partitions(void)
 326{
 327}
 328#endif /* CONFIG_BLOCK */
 329
 330#endif /* _LINUX_GENHD_H */
 331