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 extern const struct device_type disk_type;
  23 extern struct device_type part_type;
  24 extern 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
  44 struct 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
 108 enum {
 109         DISK_EVENT_MEDIA_CHANGE                 = 1 << 0, /* media changed */
 110         DISK_EVENT_EJECT_REQUEST                = 1 << 1, /* eject requested */
 111 };
 112
 113 enum {
 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
 120 struct disk_events;
 121 struct badblocks;
 122
 123 struct 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
 131 struct 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
 187 static 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
 194 static 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
 200 static inline dev_t disk_devt(struct gendisk *disk)
 201 {
 202         return MKDEV(disk->major, disk->first_minor);
 203 }
 204
 205 void disk_uevent(struct gendisk *disk, enum kobject_action action);
 206
 207 /* block/genhd.c */
 208 extern void device_add_disk(struct device *parent, struct gendisk *disk,
 209                             const struct attribute_group **groups);
 210 static inline void add_disk(struct gendisk *disk)
 211 {
 212         device_add_disk(NULL, disk, NULL);
 213 }
 214 extern void device_add_disk_no_queue_reg(struct device *parent, struct gendisk *disk);
 215 static inline void add_disk_no_queue_reg(struct gendisk *disk)
 216 {
 217         device_add_disk_no_queue_reg(NULL, disk);
 218 }
 219
 220 extern void del_gendisk(struct gendisk *gp);
 221 extern struct block_device *bdget_disk(struct gendisk *disk, int partno);
 222
 223 void set_disk_ro(struct gendisk *disk, bool read_only);
 224
 225 static 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
 231 extern void disk_block_events(struct gendisk *disk);
 232 extern void disk_unblock_events(struct gendisk *disk);
 233 extern void disk_flush_events(struct gendisk *disk, unsigned int mask);
 234 bool set_capacity_and_notify(struct gendisk *disk, sector_t size);
 235
 236 /* drivers/char/random.c */
 237 extern void add_disk_randomness(struct gendisk *disk) __latent_entropy;
 238 extern void rand_initialize_disk(struct gendisk *disk);
 239
 240 static inline sector_t get_start_sect(struct block_device *bdev)
 241 {
 242         return bdev->bd_start_sect;
 243 }
 244
 245 static inline sector_t bdev_nr_sectors(struct block_device *bdev)
 246 {
 247         return i_size_read(bdev->bd_inode) >> 9;
 248 }
 249
 250 static inline sector_t get_capacity(struct gendisk *disk)
 251 {
 252         return bdev_nr_sectors(disk->part0);
 253 }
 254
 255 int bdev_disk_changed(struct block_device *bdev, bool invalidate);
 256 int blk_add_partitions(struct gendisk *disk, struct block_device *bdev);
 257 void blk_drop_partitions(struct gendisk *disk);
 258
 259 extern struct gendisk *__alloc_disk_node(int minors, int node_id);
 260 extern 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
 280 int __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)
 284 void unregister_blkdev(unsigned int major, const char *name);
 285
 286 bool bdev_check_media_change(struct block_device *bdev);
 287 int __invalidate_device(struct block_device *bdev, bool kill_dirty);
 288 void set_capacity(struct gendisk *disk, sector_t size);
 289
 290 /* for drivers/char/raw.c: */
 291 int blkdev_ioctl(struct block_device *, fmode_t, unsigned, unsigned long);
 292 long compat_blkdev_ioctl(struct file *, unsigned, unsigned long);
 293
 294 #ifdef CONFIG_SYSFS
 295 int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk);
 296 void bd_unlink_disk_holder(struct block_device *bdev, struct gendisk *disk);
 297 #else
 298 static inline int bd_link_disk_holder(struct block_device *bdev,
 299                                       struct gendisk *disk)
 300 {
 301         return 0;
 302 }
 303 static inline void bd_unlink_disk_holder(struct block_device *bdev,
 304                                          struct gendisk *disk)
 305 {
 306 }
 307 #endif /* CONFIG_SYSFS */
 308
 309 dev_t blk_lookup_devt(const char *name, int partno);
 310 void blk_request_module(dev_t devt);
 311 #ifdef CONFIG_BLOCK
 312 void printk_all_partitions(void);
 313 #else /* CONFIG_BLOCK */
 314 static inline void printk_all_partitions(void)
 315 {
 316 }
 317 #endif /* CONFIG_BLOCK */
 318
 319 #endif /* _LINUX_GENHD_H */