1 /* SPDX-License-Identifier: GPL-2.0 */
6 * genhd.h Copyright (C) 1992 Drew Eckhardt
7 * Generic hard disk header file by
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>
22 extern const struct device_type disk_type
;
23 extern struct device_type part_type
;
24 extern struct class block_class
;
26 #define DISK_MAX_PARTS 256
27 #define DISK_NAME_LEN 32
29 #include <linux/major.h>
30 #include <linux/device.h>
31 #include <linux/smp.h>
32 #include <linux/string.h>
34 #include <linux/workqueue.h>
35 #include <linux/xarray.h>
37 #define PARTITION_META_INFO_VOLNAMELTH 64
39 * Enough for the string representation of any kind of UUID plus NULL.
40 * EFI UUID is 36 characters. MSDOS UUID is 11 characters.
42 #define PARTITION_META_INFO_UUIDLTH (UUID_STRING_LEN + 1)
44 struct partition_meta_info
{
45 char uuid
[PARTITION_META_INFO_UUIDLTH
];
46 u8 volname
[PARTITION_META_INFO_VOLNAMELTH
];
50 * DOC: genhd capability flags
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
56 * Must not be set for devices which are removed entirely when the
59 * ``GENHD_FL_CD`` (0x0008): the block device is a CD-ROM-style
61 * Affects responses to the ``CDROM_GET_CAPABILITY`` ioctl.
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.
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.
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).
79 * ``GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE`` (0x0100): event polling is
80 * blocked whenever a writer holds an exclusive lock.
82 * ``GENHD_FL_NO_PART_SCAN`` (0x0200): partition scanning is disabled.
83 * Used for loop devices in their default settings and some MMC
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.
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
105 DISK_EVENT_MEDIA_CHANGE
= 1 << 0, /* media changed */
106 DISK_EVENT_EJECT_REQUEST
= 1 << 1, /* eject requested */
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,
119 struct blk_integrity
{
120 const struct blk_integrity_profile
*profile
;
122 unsigned char tuple_size
;
123 unsigned char interval_exp
;
124 unsigned char tag_size
;
128 /* major, first_minor and minors are input parameters only,
129 * don't use directly. Use disk_devt() and disk_max_parts().
131 int major
; /* major number of driver */
133 int minors
; /* maximum number of minors, =1 for
134 * disks that can't be partitioned. */
136 char disk_name
[DISK_NAME_LEN
]; /* name of major driver */
138 unsigned short events
; /* supported events */
139 unsigned short event_flags
; /* flags related to event processing */
141 struct xarray part_tbl
;
142 struct block_device
*part0
;
144 const struct block_device_operations
*fops
;
145 struct request_queue
*queue
;
150 #define GD_NEED_PART_SCAN 0
151 #define GD_READ_ONLY 1
153 struct mutex open_mutex
; /* open/close mutex */
154 unsigned open_partitions
; /* number of open partitions */
156 struct backing_dev_info
*bdi
;
157 struct kobject
*slave_dir
;
158 #ifdef CONFIG_BLOCK_HOLDER_DEPRECATED
159 struct list_head slave_bdevs
;
161 struct timer_rand_state
*random
;
162 atomic_t sync_io
; /* RAID */
163 struct disk_events
*ev
;
164 #ifdef CONFIG_BLK_DEV_INTEGRITY
165 struct kobject integrity_kobj
;
166 #endif /* CONFIG_BLK_DEV_INTEGRITY */
167 #if IS_ENABLED(CONFIG_CDROM)
168 struct cdrom_device_info
*cdi
;
171 struct badblocks
*bb
;
172 struct lockdep_map lockdep_map
;
176 static inline bool disk_live(struct gendisk
*disk
)
178 return !inode_unhashed(disk
->part0
->bd_inode
);
182 * The gendisk is refcounted by the part0 block_device, and the bd_device
183 * therein is also used for device model presentation in sysfs.
185 #define dev_to_disk(device) \
186 (dev_to_bdev(device)->bd_disk)
187 #define disk_to_dev(disk) \
188 (&((disk)->part0->bd_device))
190 #if IS_REACHABLE(CONFIG_CDROM)
191 #define disk_to_cdi(disk) ((disk)->cdi)
193 #define disk_to_cdi(disk) NULL
196 static inline int disk_max_parts(struct gendisk
*disk
)
198 if (disk
->flags
& GENHD_FL_EXT_DEVT
)
199 return DISK_MAX_PARTS
;
203 static inline bool disk_part_scan_enabled(struct gendisk
*disk
)
205 return disk_max_parts(disk
) > 1 &&
206 !(disk
->flags
& GENHD_FL_NO_PART_SCAN
);
209 static inline dev_t
disk_devt(struct gendisk
*disk
)
211 return MKDEV(disk
->major
, disk
->first_minor
);
214 void disk_uevent(struct gendisk
*disk
, enum kobject_action action
);
217 int device_add_disk(struct device
*parent
, struct gendisk
*disk
,
218 const struct attribute_group
**groups
);
219 static inline int add_disk(struct gendisk
*disk
)
221 return device_add_disk(NULL
, disk
, NULL
);
223 extern void del_gendisk(struct gendisk
*gp
);
225 void set_disk_ro(struct gendisk
*disk
, bool read_only
);
227 static inline int get_disk_ro(struct gendisk
*disk
)
229 return disk
->part0
->bd_read_only
||
230 test_bit(GD_READ_ONLY
, &disk
->state
);
233 extern void disk_block_events(struct gendisk
*disk
);
234 extern void disk_unblock_events(struct gendisk
*disk
);
235 extern void disk_flush_events(struct gendisk
*disk
, unsigned int mask
);
236 bool set_capacity_and_notify(struct gendisk
*disk
, sector_t size
);
237 bool disk_force_media_change(struct gendisk
*disk
, unsigned int events
);
239 /* drivers/char/random.c */
240 extern void add_disk_randomness(struct gendisk
*disk
) __latent_entropy
;
241 extern void rand_initialize_disk(struct gendisk
*disk
);
243 static inline sector_t
get_start_sect(struct block_device
*bdev
)
245 return bdev
->bd_start_sect
;
248 static inline sector_t
bdev_nr_sectors(struct block_device
*bdev
)
250 return i_size_read(bdev
->bd_inode
) >> 9;
253 static inline sector_t
get_capacity(struct gendisk
*disk
)
255 return bdev_nr_sectors(disk
->part0
);
258 int bdev_disk_changed(struct gendisk
*disk
, bool invalidate
);
259 void blk_drop_partitions(struct gendisk
*disk
);
261 struct gendisk
*__alloc_disk_node(struct request_queue
*q
, int node_id
,
262 struct lock_class_key
*lkclass
);
263 extern void put_disk(struct gendisk
*disk
);
264 struct gendisk
*__blk_alloc_disk(int node
, struct lock_class_key
*lkclass
);
267 * blk_alloc_disk - allocate a gendisk structure
268 * @node_id: numa node to allocate on
270 * Allocate and pre-initialize a gendisk structure for use with BIO based
275 #define blk_alloc_disk(node_id) \
277 static struct lock_class_key __key; \
279 __blk_alloc_disk(node_id, &__key); \
281 void blk_cleanup_disk(struct gendisk
*disk
);
283 int __register_blkdev(unsigned int major
, const char *name
,
284 void (*probe
)(dev_t devt
));
285 #define register_blkdev(major, name) \
286 __register_blkdev(major, name, NULL)
287 void unregister_blkdev(unsigned int major
, const char *name
);
289 bool bdev_check_media_change(struct block_device
*bdev
);
290 int __invalidate_device(struct block_device
*bdev
, bool kill_dirty
);
291 void set_capacity(struct gendisk
*disk
, sector_t size
);
293 /* for drivers/char/raw.c: */
294 int blkdev_ioctl(struct block_device
*, fmode_t
, unsigned, unsigned long);
295 long compat_blkdev_ioctl(struct file
*, unsigned, unsigned long);
297 #ifdef CONFIG_BLOCK_HOLDER_DEPRECATED
298 int bd_link_disk_holder(struct block_device
*bdev
, struct gendisk
*disk
);
299 void bd_unlink_disk_holder(struct block_device
*bdev
, struct gendisk
*disk
);
300 int bd_register_pending_holders(struct gendisk
*disk
);
302 static inline int bd_link_disk_holder(struct block_device
*bdev
,
303 struct gendisk
*disk
)
307 static inline void bd_unlink_disk_holder(struct block_device
*bdev
,
308 struct gendisk
*disk
)
311 static inline int bd_register_pending_holders(struct gendisk
*disk
)
315 #endif /* CONFIG_BLOCK_HOLDER_DEPRECATED */
317 dev_t
part_devt(struct gendisk
*disk
, u8 partno
);
318 void inc_diskseq(struct gendisk
*disk
);
319 dev_t
blk_lookup_devt(const char *name
, int partno
);
320 void blk_request_module(dev_t devt
);
322 void printk_all_partitions(void);
323 #else /* CONFIG_BLOCK */
324 static inline void printk_all_partitions(void)
327 #endif /* CONFIG_BLOCK */
329 #endif /* _LINUX_GENHD_H */