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_UP`` (0x0010): indicates that the block device is "up",
  64 * with a similar meaning to network interfaces.
  65 *
  66 * ``GENHD_FL_SUPPRESS_PARTITION_INFO`` (0x0020): don't include
  67 * partition information in ``/proc/partitions`` or in the output of
  68 * printk_all_partitions().
  69 * Used for the null block device and some MMC devices.
  70 *
  71 * ``GENHD_FL_EXT_DEVT`` (0x0040): the driver supports extended
  72 * dynamic ``dev_t``, i.e. it wants extended device numbers
  73 * (``BLOCK_EXT_MAJOR``).
  74 * This affects the maximum number of partitions.
  75 *
  76 * ``GENHD_FL_NATIVE_CAPACITY`` (0x0080): based on information in the
  77 * partition table, the device's capacity has been extended to its
  78 * native capacity; i.e. the device has hidden capacity used by one
  79 * of the partitions (this is a flag used so that native capacity is
  80 * only ever unlocked once).
  81 *
  82 * ``GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE`` (0x0100): event polling is
  83 * blocked whenever a writer holds an exclusive lock.
  84 *
  85 * ``GENHD_FL_NO_PART_SCAN`` (0x0200): partition scanning is disabled.
  86 * Used for loop devices in their default settings and some MMC
  87 * devices.
  88 *
  89 * ``GENHD_FL_HIDDEN`` (0x0400): the block device is hidden; it
  90 * doesn't produce events, doesn't appear in sysfs, and doesn't have
  91 * an associated ``bdev``.
  92 * Implies ``GENHD_FL_SUPPRESS_PARTITION_INFO`` and
  93 * ``GENHD_FL_NO_PART_SCAN``.
  94 * Used for multipath devices.
  95 */
  96#define GENHD_FL_REMOVABLE                      0x0001
  97/* 2 is unused (used to be GENHD_FL_DRIVERFS) */
  98/* 4 is unused (used to be GENHD_FL_MEDIA_CHANGE_NOTIFY) */
  99#define GENHD_FL_CD                             0x0008
 100#define GENHD_FL_UP                             0x0010
 101#define GENHD_FL_SUPPRESS_PARTITION_INFO        0x0020
 102#define GENHD_FL_EXT_DEVT                       0x0040
 103#define GENHD_FL_NATIVE_CAPACITY                0x0080
 104#define GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE     0x0100
 105#define GENHD_FL_NO_PART_SCAN                   0x0200
 106#define GENHD_FL_HIDDEN                         0x0400
 107
 108enum {
 109        DISK_EVENT_MEDIA_CHANGE                 = 1 << 0, /* media changed */
 110        DISK_EVENT_EJECT_REQUEST                = 1 << 1, /* eject requested */
 111};
 112
 113enum {
 114        /* Poll even if events_poll_msecs is unset */
 115        DISK_EVENT_FLAG_POLL                    = 1 << 0,
 116        /* Forward events to udev */
 117        DISK_EVENT_FLAG_UEVENT                  = 1 << 1,
 118};
 119
 120struct disk_events;
 121struct badblocks;
 122
 123struct blk_integrity {
 124        const struct blk_integrity_profile      *profile;
 125        unsigned char                           flags;
 126        unsigned char                           tuple_size;
 127        unsigned char                           interval_exp;
 128        unsigned char                           tag_size;
 129};
 130
 131struct gendisk {
 132        /* major, first_minor and minors are input parameters only,
 133         * don't use directly.  Use disk_devt() and disk_max_parts().
 134         */
 135        int major;                      /* major number of driver */
 136        int first_minor;
 137        int minors;                     /* maximum number of minors, =1 for
 138                                         * disks that can't be partitioned. */
 139
 140        char disk_name[DISK_NAME_LEN];  /* name of major driver */
 141
 142        unsigned short events;          /* supported events */
 143        unsigned short event_flags;     /* flags related to event processing */
 144
 145        struct xarray part_tbl;
 146        struct block_device *part0;
 147
 148        const struct block_device_operations *fops;
 149        struct request_queue *queue;
 150        void *private_data;
 151
 152        int flags;
 153        unsigned long state;
 154#define GD_NEED_PART_SCAN               0
 155#define GD_READ_ONLY                    1
 156        struct kobject *slave_dir;
 157
 158        struct timer_rand_state *random;
 159        atomic_t sync_io;               /* RAID */
 160        struct disk_events *ev;
 161#ifdef  CONFIG_BLK_DEV_INTEGRITY
 162        struct kobject integrity_kobj;
 163#endif  /* CONFIG_BLK_DEV_INTEGRITY */
 164#if IS_ENABLED(CONFIG_CDROM)
 165        struct cdrom_device_info *cdi;
 166#endif
 167        int node_id;
 168        struct badblocks *bb;
 169        struct lockdep_map lockdep_map;
 170};
 171
 172/*
 173 * The gendisk is refcounted by the part0 block_device, and the bd_device
 174 * therein is also used for device model presentation in sysfs.
 175 */
 176#define dev_to_disk(device) \
 177        (dev_to_bdev(device)->bd_disk)
 178#define disk_to_dev(disk) \
 179        (&((disk)->part0->bd_device))
 180
 181#if IS_REACHABLE(CONFIG_CDROM)
 182#define disk_to_cdi(disk)       ((disk)->cdi)
 183#else
 184#define disk_to_cdi(disk)       NULL
 185#endif
 186
 187static inline int disk_max_parts(struct gendisk *disk)
 188{
 189        if (disk->flags & GENHD_FL_EXT_DEVT)
 190                return DISK_MAX_PARTS;
 191        return disk->minors;
 192}
 193
 194static inline bool disk_part_scan_enabled(struct gendisk *disk)
 195{
 196        return disk_max_parts(disk) > 1 &&
 197                !(disk->flags & GENHD_FL_NO_PART_SCAN);
 198}
 199
 200static inline dev_t disk_devt(struct gendisk *disk)
 201{
 202        return MKDEV(disk->major, disk->first_minor);
 203}
 204
 205void disk_uevent(struct gendisk *disk, enum kobject_action action);
 206
 207/* block/genhd.c */
 208extern void device_add_disk(struct device *parent, struct gendisk *disk,
 209                            const struct attribute_group **groups);
 210static inline void add_disk(struct gendisk *disk)
 211{
 212        device_add_disk(NULL, disk, NULL);
 213}
 214extern void device_add_disk_no_queue_reg(struct device *parent, struct gendisk *disk);
 215static inline void add_disk_no_queue_reg(struct gendisk *disk)
 216{
 217        device_add_disk_no_queue_reg(NULL, disk);
 218}
 219
 220extern void del_gendisk(struct gendisk *gp);
 221extern struct block_device *bdget_disk(struct gendisk *disk, int partno);
 222
 223void set_disk_ro(struct gendisk *disk, bool read_only);
 224
 225static inline int get_disk_ro(struct gendisk *disk)
 226{
 227        return disk->part0->bd_read_only ||
 228                test_bit(GD_READ_ONLY, &disk->state);
 229}
 230
 231extern void disk_block_events(struct gendisk *disk);
 232extern void disk_unblock_events(struct gendisk *disk);
 233extern void disk_flush_events(struct gendisk *disk, unsigned int mask);
 234bool set_capacity_and_notify(struct gendisk *disk, sector_t size);
 235
 236/* drivers/char/random.c */
 237extern void add_disk_randomness(struct gendisk *disk) __latent_entropy;
 238extern void rand_initialize_disk(struct gendisk *disk);
 239
 240static inline sector_t get_start_sect(struct block_device *bdev)
 241{
 242        return bdev->bd_start_sect;
 243}
 244
 245static inline sector_t bdev_nr_sectors(struct block_device *bdev)
 246{
 247        return i_size_read(bdev->bd_inode) >> 9;
 248}
 249
 250static inline sector_t get_capacity(struct gendisk *disk)
 251{
 252        return bdev_nr_sectors(disk->part0);
 253}
 254
 255int bdev_disk_changed(struct block_device *bdev, bool invalidate);
 256int blk_add_partitions(struct gendisk *disk, struct block_device *bdev);
 257void blk_drop_partitions(struct gendisk *disk);
 258
 259extern struct gendisk *__alloc_disk_node(int minors, int node_id);
 260extern void put_disk(struct gendisk *disk);
 261
 262#define alloc_disk_node(minors, node_id)                                \
 263({                                                                      \
 264        static struct lock_class_key __key;                             \
 265        const char *__name;                                             \
 266        struct gendisk *__disk;                                         \
 267                                                                        \
 268        __name = "(gendisk_completion)"#minors"("#node_id")";           \
 269                                                                        \
 270        __disk = __alloc_disk_node(minors, node_id);                    \
 271                                                                        \
 272        if (__disk)                                                     \
 273                lockdep_init_map(&__disk->lockdep_map, __name, &__key, 0); \
 274                                                                        \
 275        __disk;                                                         \
 276})
 277
 278#define alloc_disk(minors) alloc_disk_node(minors, NUMA_NO_NODE)
 279
 280int __register_blkdev(unsigned int major, const char *name,
 281                void (*probe)(dev_t devt));
 282#define register_blkdev(major, name) \
 283        __register_blkdev(major, name, NULL)
 284void unregister_blkdev(unsigned int major, const char *name);
 285
 286bool bdev_check_media_change(struct block_device *bdev);
 287int __invalidate_device(struct block_device *bdev, bool kill_dirty);
 288void set_capacity(struct gendisk *disk, sector_t size);
 289
 290/* for drivers/char/raw.c: */
 291int blkdev_ioctl(struct block_device *, fmode_t, unsigned, unsigned long);
 292long compat_blkdev_ioctl(struct file *, unsigned, unsigned long);
 293
 294#ifdef CONFIG_SYSFS
 295int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk);
 296void bd_unlink_disk_holder(struct block_device *bdev, struct gendisk *disk);
 297#else
 298static inline int bd_link_disk_holder(struct block_device *bdev,
 299                                      struct gendisk *disk)
 300{
 301        return 0;
 302}
 303static inline void bd_unlink_disk_holder(struct block_device *bdev,
 304                                         struct gendisk *disk)
 305{
 306}
 307#endif /* CONFIG_SYSFS */
 308
 309dev_t blk_lookup_devt(const char *name, int partno);
 310void blk_request_module(dev_t devt);
 311#ifdef CONFIG_BLOCK
 312void printk_all_partitions(void);
 313#else /* CONFIG_BLOCK */
 314static inline void printk_all_partitions(void)
 315{
 316}
 317#endif /* CONFIG_BLOCK */
 318
 319#endif /* _LINUX_GENHD_H */
 320