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#define GD_QUEUE_REF                    2
 157
 158        struct mutex open_mutex;        /* open/close mutex */
 159        unsigned open_partitions;       /* number of open partitions */
 160
 161        struct kobject *slave_dir;
 162
 163        struct timer_rand_state *random;
 164        atomic_t sync_io;               /* RAID */
 165        struct disk_events *ev;
 166#ifdef  CONFIG_BLK_DEV_INTEGRITY
 167        struct kobject integrity_kobj;
 168#endif  /* CONFIG_BLK_DEV_INTEGRITY */
 169#if IS_ENABLED(CONFIG_CDROM)
 170        struct cdrom_device_info *cdi;
 171#endif
 172        int node_id;
 173        struct badblocks *bb;
 174        struct lockdep_map lockdep_map;
 175};
 176
 177/*
 178 * The gendisk is refcounted by the part0 block_device, and the bd_device
 179 * therein is also used for device model presentation in sysfs.
 180 */
 181#define dev_to_disk(device) \
 182        (dev_to_bdev(device)->bd_disk)
 183#define disk_to_dev(disk) \
 184        (&((disk)->part0->bd_device))
 185
 186#if IS_REACHABLE(CONFIG_CDROM)
 187#define disk_to_cdi(disk)       ((disk)->cdi)
 188#else
 189#define disk_to_cdi(disk)       NULL
 190#endif
 191
 192static inline int disk_max_parts(struct gendisk *disk)
 193{
 194        if (disk->flags & GENHD_FL_EXT_DEVT)
 195                return DISK_MAX_PARTS;
 196        return disk->minors;
 197}
 198
 199static inline bool disk_part_scan_enabled(struct gendisk *disk)
 200{
 201        return disk_max_parts(disk) > 1 &&
 202                !(disk->flags & GENHD_FL_NO_PART_SCAN);
 203}
 204
 205static inline dev_t disk_devt(struct gendisk *disk)
 206{
 207        return MKDEV(disk->major, disk->first_minor);
 208}
 209
 210void disk_uevent(struct gendisk *disk, enum kobject_action action);
 211
 212/* block/genhd.c */
 213extern void device_add_disk(struct device *parent, struct gendisk *disk,
 214                            const struct attribute_group **groups);
 215static inline void add_disk(struct gendisk *disk)
 216{
 217        device_add_disk(NULL, disk, NULL);
 218}
 219extern void device_add_disk_no_queue_reg(struct device *parent, struct gendisk *disk);
 220static inline void add_disk_no_queue_reg(struct gendisk *disk)
 221{
 222        device_add_disk_no_queue_reg(NULL, disk);
 223}
 224
 225extern void del_gendisk(struct gendisk *gp);
 226
 227void set_disk_ro(struct gendisk *disk, bool read_only);
 228
 229static inline int get_disk_ro(struct gendisk *disk)
 230{
 231        return disk->part0->bd_read_only ||
 232                test_bit(GD_READ_ONLY, &disk->state);
 233}
 234
 235extern void disk_block_events(struct gendisk *disk);
 236extern void disk_unblock_events(struct gendisk *disk);
 237extern void disk_flush_events(struct gendisk *disk, unsigned int mask);
 238bool set_capacity_and_notify(struct gendisk *disk, sector_t size);
 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
 262extern struct gendisk *__alloc_disk_node(int minors, int node_id);
 263extern void put_disk(struct gendisk *disk);
 264
 265#define alloc_disk_node(minors, node_id)                                \
 266({                                                                      \
 267        static struct lock_class_key __key;                             \
 268        const char *__name;                                             \
 269        struct gendisk *__disk;                                         \
 270                                                                        \
 271        __name = "(gendisk_completion)"#minors"("#node_id")";           \
 272                                                                        \
 273        __disk = __alloc_disk_node(minors, node_id);                    \
 274                                                                        \
 275        if (__disk)                                                     \
 276                lockdep_init_map(&__disk->lockdep_map, __name, &__key, 0); \
 277                                                                        \
 278        __disk;                                                         \
 279})
 280
 281#define alloc_disk(minors) alloc_disk_node(minors, NUMA_NO_NODE)
 282
 283/**
 284 * blk_alloc_disk - allocate a gendisk structure
 285 * @node_id: numa node to allocate on
 286 *
 287 * Allocate and pre-initialize a gendisk structure for use with BIO based
 288 * drivers.
 289 *
 290 * Context: can sleep
 291 */
 292#define blk_alloc_disk(node_id)                                         \
 293({                                                                      \
 294        struct gendisk *__disk = __blk_alloc_disk(node_id);             \
 295        static struct lock_class_key __key;                             \
 296                                                                        \
 297        if (__disk)                                                     \
 298                lockdep_init_map(&__disk->lockdep_map,                  \
 299                        "(bio completion)", &__key, 0);                 \
 300        __disk;                                                         \
 301})
 302struct gendisk *__blk_alloc_disk(int node);
 303void blk_cleanup_disk(struct gendisk *disk);
 304
 305int __register_blkdev(unsigned int major, const char *name,
 306                void (*probe)(dev_t devt));
 307#define register_blkdev(major, name) \
 308        __register_blkdev(major, name, NULL)
 309void unregister_blkdev(unsigned int major, const char *name);
 310
 311bool bdev_check_media_change(struct block_device *bdev);
 312int __invalidate_device(struct block_device *bdev, bool kill_dirty);
 313void set_capacity(struct gendisk *disk, sector_t size);
 314
 315/* for drivers/char/raw.c: */
 316int blkdev_ioctl(struct block_device *, fmode_t, unsigned, unsigned long);
 317long compat_blkdev_ioctl(struct file *, unsigned, unsigned long);
 318
 319#ifdef CONFIG_SYSFS
 320int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk);
 321void bd_unlink_disk_holder(struct block_device *bdev, struct gendisk *disk);
 322#else
 323static inline int bd_link_disk_holder(struct block_device *bdev,
 324                                      struct gendisk *disk)
 325{
 326        return 0;
 327}
 328static inline void bd_unlink_disk_holder(struct block_device *bdev,
 329                                         struct gendisk *disk)
 330{
 331}
 332#endif /* CONFIG_SYSFS */
 333
 334dev_t part_devt(struct gendisk *disk, u8 partno);
 335dev_t blk_lookup_devt(const char *name, int partno);
 336void blk_request_module(dev_t devt);
 337#ifdef CONFIG_BLOCK
 338void printk_all_partitions(void);
 339#else /* CONFIG_BLOCK */
 340static inline void printk_all_partitions(void)
 341{
 342}
 343#endif /* CONFIG_BLOCK */
 344
 345#endif /* _LINUX_GENHD_H */
 346