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/uuid.h>
  16#include <linux/blk_types.h>
  17#include <linux/device.h>
  18#include <linux/xarray.h>
  19
  20extern const struct device_type disk_type;
  21extern struct device_type part_type;
  22extern struct class block_class;
  23
  24#define DISK_MAX_PARTS                  256
  25#define DISK_NAME_LEN                   32
  26
  27#define PARTITION_META_INFO_VOLNAMELTH  64
  28/*
  29 * Enough for the string representation of any kind of UUID plus NULL.
  30 * EFI UUID is 36 characters. MSDOS UUID is 11 characters.
  31 */
  32#define PARTITION_META_INFO_UUIDLTH     (UUID_STRING_LEN + 1)
  33
  34struct partition_meta_info {
  35        char uuid[PARTITION_META_INFO_UUIDLTH];
  36        u8 volname[PARTITION_META_INFO_VOLNAMELTH];
  37};
  38
  39/**
  40 * DOC: genhd capability flags
  41 *
  42 * ``GENHD_FL_REMOVABLE`` (0x0001): indicates that the block device
  43 * gives access to removable media.
  44 * When set, the device remains present even when media is not
  45 * inserted.
  46 * Must not be set for devices which are removed entirely when the
  47 * media is removed.
  48 *
  49 * ``GENHD_FL_CD`` (0x0008): the block device is a CD-ROM-style
  50 * device.
  51 * Affects responses to the ``CDROM_GET_CAPABILITY`` ioctl.
  52 *
  53 * ``GENHD_FL_SUPPRESS_PARTITION_INFO`` (0x0020): don't include
  54 * partition information in ``/proc/partitions`` or in the output of
  55 * printk_all_partitions().
  56 * Used for the null block device and some MMC devices.
  57 *
  58 * ``GENHD_FL_EXT_DEVT`` (0x0040): the driver supports extended
  59 * dynamic ``dev_t``, i.e. it wants extended device numbers
  60 * (``BLOCK_EXT_MAJOR``).
  61 * This affects the maximum number of partitions.
  62 *
  63 * ``GENHD_FL_NATIVE_CAPACITY`` (0x0080): based on information in the
  64 * partition table, the device's capacity has been extended to its
  65 * native capacity; i.e. the device has hidden capacity used by one
  66 * of the partitions (this is a flag used so that native capacity is
  67 * only ever unlocked once).
  68 *
  69 * ``GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE`` (0x0100): event polling is
  70 * blocked whenever a writer holds an exclusive lock.
  71 *
  72 * ``GENHD_FL_NO_PART_SCAN`` (0x0200): partition scanning is disabled.
  73 * Used for loop devices in their default settings and some MMC
  74 * devices.
  75 *
  76 * ``GENHD_FL_HIDDEN`` (0x0400): the block device is hidden; it
  77 * doesn't produce events, doesn't appear in sysfs, and doesn't have
  78 * an associated ``bdev``.
  79 * Implies ``GENHD_FL_SUPPRESS_PARTITION_INFO`` and
  80 * ``GENHD_FL_NO_PART_SCAN``.
  81 * Used for multipath devices.
  82 */
  83#define GENHD_FL_REMOVABLE                      0x0001
  84/* 2 is unused (used to be GENHD_FL_DRIVERFS) */
  85/* 4 is unused (used to be GENHD_FL_MEDIA_CHANGE_NOTIFY) */
  86#define GENHD_FL_CD                             0x0008
  87#define GENHD_FL_SUPPRESS_PARTITION_INFO        0x0020
  88#define GENHD_FL_EXT_DEVT                       0x0040
  89#define GENHD_FL_NATIVE_CAPACITY                0x0080
  90#define GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE     0x0100
  91#define GENHD_FL_NO_PART_SCAN                   0x0200
  92#define GENHD_FL_HIDDEN                         0x0400
  93
  94enum {
  95        DISK_EVENT_MEDIA_CHANGE                 = 1 << 0, /* media changed */
  96        DISK_EVENT_EJECT_REQUEST                = 1 << 1, /* eject requested */
  97};
  98
  99enum {
 100        /* Poll even if events_poll_msecs is unset */
 101        DISK_EVENT_FLAG_POLL                    = 1 << 0,
 102        /* Forward events to udev */
 103        DISK_EVENT_FLAG_UEVENT                  = 1 << 1,
 104};
 105
 106struct disk_events;
 107struct badblocks;
 108
 109struct blk_integrity {
 110        const struct blk_integrity_profile      *profile;
 111        unsigned char                           flags;
 112        unsigned char                           tuple_size;
 113        unsigned char                           interval_exp;
 114        unsigned char                           tag_size;
 115};
 116
 117struct gendisk {
 118        /* major, first_minor and minors are input parameters only,
 119         * don't use directly.  Use disk_devt() and disk_max_parts().
 120         */
 121        int major;                      /* major number of driver */
 122        int first_minor;
 123        int minors;                     /* maximum number of minors, =1 for
 124                                         * disks that can't be partitioned. */
 125
 126        char disk_name[DISK_NAME_LEN];  /* name of major driver */
 127
 128        unsigned short events;          /* supported events */
 129        unsigned short event_flags;     /* flags related to event processing */
 130
 131        struct xarray part_tbl;
 132        struct block_device *part0;
 133
 134        const struct block_device_operations *fops;
 135        struct request_queue *queue;
 136        void *private_data;
 137
 138        int flags;
 139        unsigned long state;
 140#define GD_NEED_PART_SCAN               0
 141#define GD_READ_ONLY                    1
 142#define GD_DEAD                         2
 143
 144        struct mutex open_mutex;        /* open/close mutex */
 145        unsigned open_partitions;       /* number of open partitions */
 146
 147        struct backing_dev_info *bdi;
 148        struct kobject *slave_dir;
 149#ifdef CONFIG_BLOCK_HOLDER_DEPRECATED
 150        struct list_head slave_bdevs;
 151#endif
 152        struct timer_rand_state *random;
 153        atomic_t sync_io;               /* RAID */
 154        struct disk_events *ev;
 155#ifdef  CONFIG_BLK_DEV_INTEGRITY
 156        struct kobject integrity_kobj;
 157#endif  /* CONFIG_BLK_DEV_INTEGRITY */
 158#if IS_ENABLED(CONFIG_CDROM)
 159        struct cdrom_device_info *cdi;
 160#endif
 161        int node_id;
 162        struct badblocks *bb;
 163        struct lockdep_map lockdep_map;
 164        u64 diskseq;
 165};
 166
 167static inline bool disk_live(struct gendisk *disk)
 168{
 169        return !inode_unhashed(disk->part0->bd_inode);
 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 */
 208int __must_check device_add_disk(struct device *parent, struct gendisk *disk,
 209                                 const struct attribute_group **groups);
 210static inline int __must_check add_disk(struct gendisk *disk)
 211{
 212        return device_add_disk(NULL, disk, NULL);
 213}
 214extern void del_gendisk(struct gendisk *gp);
 215
 216void invalidate_disk(struct gendisk *disk);
 217
 218void set_disk_ro(struct gendisk *disk, bool read_only);
 219
 220static inline int get_disk_ro(struct gendisk *disk)
 221{
 222        return disk->part0->bd_read_only ||
 223                test_bit(GD_READ_ONLY, &disk->state);
 224}
 225
 226static inline int bdev_read_only(struct block_device *bdev)
 227{
 228        return bdev->bd_read_only || get_disk_ro(bdev->bd_disk);
 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);
 235bool disk_force_media_change(struct gendisk *disk, unsigned int events);
 236
 237/* drivers/char/random.c */
 238extern void add_disk_randomness(struct gendisk *disk) __latent_entropy;
 239extern void rand_initialize_disk(struct gendisk *disk);
 240
 241static inline sector_t get_start_sect(struct block_device *bdev)
 242{
 243        return bdev->bd_start_sect;
 244}
 245
 246static inline sector_t bdev_nr_sectors(struct block_device *bdev)
 247{
 248        return bdev->bd_nr_sectors;
 249}
 250
 251static inline loff_t bdev_nr_bytes(struct block_device *bdev)
 252{
 253        return (loff_t)bdev_nr_sectors(bdev) << SECTOR_SHIFT;
 254}
 255
 256static inline sector_t get_capacity(struct gendisk *disk)
 257{
 258        return bdev_nr_sectors(disk->part0);
 259}
 260
 261static inline u64 sb_bdev_nr_blocks(struct super_block *sb)
 262{
 263        return bdev_nr_sectors(sb->s_bdev) >>
 264                (sb->s_blocksize_bits - SECTOR_SHIFT);
 265}
 266
 267int bdev_disk_changed(struct gendisk *disk, bool invalidate);
 268void blk_drop_partitions(struct gendisk *disk);
 269
 270struct gendisk *__alloc_disk_node(struct request_queue *q, int node_id,
 271                struct lock_class_key *lkclass);
 272extern void put_disk(struct gendisk *disk);
 273struct gendisk *__blk_alloc_disk(int node, struct lock_class_key *lkclass);
 274
 275/**
 276 * blk_alloc_disk - allocate a gendisk structure
 277 * @node_id: numa node to allocate on
 278 *
 279 * Allocate and pre-initialize a gendisk structure for use with BIO based
 280 * drivers.
 281 *
 282 * Context: can sleep
 283 */
 284#define blk_alloc_disk(node_id)                                         \
 285({                                                                      \
 286        static struct lock_class_key __key;                             \
 287                                                                        \
 288        __blk_alloc_disk(node_id, &__key);                              \
 289})
 290void blk_cleanup_disk(struct gendisk *disk);
 291
 292int __register_blkdev(unsigned int major, const char *name,
 293                void (*probe)(dev_t devt));
 294#define register_blkdev(major, name) \
 295        __register_blkdev(major, name, NULL)
 296void unregister_blkdev(unsigned int major, const char *name);
 297
 298bool bdev_check_media_change(struct block_device *bdev);
 299int __invalidate_device(struct block_device *bdev, bool kill_dirty);
 300void set_capacity(struct gendisk *disk, sector_t size);
 301
 302#ifdef CONFIG_BLOCK_HOLDER_DEPRECATED
 303int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk);
 304void bd_unlink_disk_holder(struct block_device *bdev, struct gendisk *disk);
 305int bd_register_pending_holders(struct gendisk *disk);
 306#else
 307static inline int bd_link_disk_holder(struct block_device *bdev,
 308                                      struct gendisk *disk)
 309{
 310        return 0;
 311}
 312static inline void bd_unlink_disk_holder(struct block_device *bdev,
 313                                         struct gendisk *disk)
 314{
 315}
 316static inline int bd_register_pending_holders(struct gendisk *disk)
 317{
 318        return 0;
 319}
 320#endif /* CONFIG_BLOCK_HOLDER_DEPRECATED */
 321
 322dev_t part_devt(struct gendisk *disk, u8 partno);
 323void inc_diskseq(struct gendisk *disk);
 324dev_t blk_lookup_devt(const char *name, int partno);
 325void blk_request_module(dev_t devt);
 326#ifdef CONFIG_BLOCK
 327void printk_all_partitions(void);
 328#else /* CONFIG_BLOCK */
 329static inline void printk_all_partitions(void)
 330{
 331}
 332#endif /* CONFIG_BLOCK */
 333
 334#endif /* _LINUX_GENHD_H */
 335