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_UP`` (0x0010): indicates that the block device is "up",
64 * with a similar meaning to network interfaces.
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.
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.
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).
82 * ``GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE`` (0x0100): event polling is
83 * blocked whenever a writer holds an exclusive lock.
85 * ``GENHD_FL_NO_PART_SCAN`` (0x0200): partition scanning is disabled.
86 * Used for loop devices in their default settings and some MMC
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.
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
109 DISK_EVENT_MEDIA_CHANGE = 1 << 0, /* media changed */
110 DISK_EVENT_EJECT_REQUEST = 1 << 1, /* eject requested */
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,
123 struct blk_integrity {
124 const struct blk_integrity_profile *profile;
126 unsigned char tuple_size;
127 unsigned char interval_exp;
128 unsigned char tag_size;
132 /* major, first_minor and minors are input parameters only,
133 * don't use directly. Use disk_devt() and disk_max_parts().
135 int major; /* major number of driver */
137 int minors; /* maximum number of minors, =1 for
138 * disks that can't be partitioned. */
140 char disk_name[DISK_NAME_LEN]; /* name of major driver */
142 unsigned short events; /* supported events */
143 unsigned short event_flags; /* flags related to event processing */
145 struct xarray part_tbl;
146 struct block_device *part0;
148 const struct block_device_operations *fops;
149 struct request_queue *queue;
154 #define GD_NEED_PART_SCAN 0
155 #define GD_READ_ONLY 1
156 #define GD_QUEUE_REF 2
158 struct mutex open_mutex; /* open/close mutex */
159 unsigned open_partitions; /* number of open partitions */
161 struct kobject *slave_dir;
162 #ifdef CONFIG_BLOCK_HOLDER_DEPRECATED
163 struct list_head slave_bdevs;
165 struct timer_rand_state *random;
166 atomic_t sync_io; /* RAID */
167 struct disk_events *ev;
168 #ifdef CONFIG_BLK_DEV_INTEGRITY
169 struct kobject integrity_kobj;
170 #endif /* CONFIG_BLK_DEV_INTEGRITY */
171 #if IS_ENABLED(CONFIG_CDROM)
172 struct cdrom_device_info *cdi;
175 struct badblocks *bb;
176 struct lockdep_map lockdep_map;
181 * The gendisk is refcounted by the part0 block_device, and the bd_device
182 * therein is also used for device model presentation in sysfs.
184 #define dev_to_disk(device) \
185 (dev_to_bdev(device)->bd_disk)
186 #define disk_to_dev(disk) \
187 (&((disk)->part0->bd_device))
189 #if IS_REACHABLE(CONFIG_CDROM)
190 #define disk_to_cdi(disk) ((disk)->cdi)
192 #define disk_to_cdi(disk) NULL
195 static inline int disk_max_parts(struct gendisk *disk)
197 if (disk->flags & GENHD_FL_EXT_DEVT)
198 return DISK_MAX_PARTS;
202 static inline bool disk_part_scan_enabled(struct gendisk *disk)
204 return disk_max_parts(disk) > 1 &&
205 !(disk->flags & GENHD_FL_NO_PART_SCAN);
208 static inline dev_t disk_devt(struct gendisk *disk)
210 return MKDEV(disk->major, disk->first_minor);
213 void disk_uevent(struct gendisk *disk, enum kobject_action action);
216 extern void device_add_disk(struct device *parent, struct gendisk *disk,
217 const struct attribute_group **groups);
218 static inline void add_disk(struct gendisk *disk)
220 device_add_disk(NULL, disk, NULL);
222 extern void del_gendisk(struct gendisk *gp);
224 void set_disk_ro(struct gendisk *disk, bool read_only);
226 static inline int get_disk_ro(struct gendisk *disk)
228 return disk->part0->bd_read_only ||
229 test_bit(GD_READ_ONLY, &disk->state);
232 extern void disk_block_events(struct gendisk *disk);
233 extern void disk_unblock_events(struct gendisk *disk);
234 extern void disk_flush_events(struct gendisk *disk, unsigned int mask);
235 bool set_capacity_and_notify(struct gendisk *disk, sector_t size);
236 bool disk_force_media_change(struct gendisk *disk, unsigned int events);
238 /* drivers/char/random.c */
239 extern void add_disk_randomness(struct gendisk *disk) __latent_entropy;
240 extern void rand_initialize_disk(struct gendisk *disk);
242 static inline sector_t get_start_sect(struct block_device *bdev)
244 return bdev->bd_start_sect;
247 static inline sector_t bdev_nr_sectors(struct block_device *bdev)
249 return i_size_read(bdev->bd_inode) >> 9;
252 static inline sector_t get_capacity(struct gendisk *disk)
254 return bdev_nr_sectors(disk->part0);
257 int bdev_disk_changed(struct gendisk *disk, bool invalidate);
258 void blk_drop_partitions(struct gendisk *disk);
260 extern struct gendisk *__alloc_disk_node(int minors, int node_id);
261 extern void put_disk(struct gendisk *disk);
263 #define alloc_disk_node(minors, node_id) \
265 static struct lock_class_key __key; \
266 const char *__name; \
267 struct gendisk *__disk; \
269 __name = "(gendisk_completion)"#minors"("#node_id")"; \
271 __disk = __alloc_disk_node(minors, node_id); \
274 lockdep_init_map(&__disk->lockdep_map, __name, &__key, 0); \
279 #define alloc_disk(minors) alloc_disk_node(minors, NUMA_NO_NODE)
282 * blk_alloc_disk - allocate a gendisk structure
283 * @node_id: numa node to allocate on
285 * Allocate and pre-initialize a gendisk structure for use with BIO based
290 #define blk_alloc_disk(node_id) \
292 struct gendisk *__disk = __blk_alloc_disk(node_id); \
293 static struct lock_class_key __key; \
296 lockdep_init_map(&__disk->lockdep_map, \
297 "(bio completion)", &__key, 0); \
300 struct gendisk *__blk_alloc_disk(int node);
301 void blk_cleanup_disk(struct gendisk *disk);
303 int __register_blkdev(unsigned int major, const char *name,
304 void (*probe)(dev_t devt));
305 #define register_blkdev(major, name) \
306 __register_blkdev(major, name, NULL)
307 void unregister_blkdev(unsigned int major, const char *name);
309 bool bdev_check_media_change(struct block_device *bdev);
310 int __invalidate_device(struct block_device *bdev, bool kill_dirty);
311 void set_capacity(struct gendisk *disk, sector_t size);
313 /* for drivers/char/raw.c: */
314 int blkdev_ioctl(struct block_device *, fmode_t, unsigned, unsigned long);
315 long compat_blkdev_ioctl(struct file *, unsigned, unsigned long);
317 #ifdef CONFIG_BLOCK_HOLDER_DEPRECATED
318 int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk);
319 void bd_unlink_disk_holder(struct block_device *bdev, struct gendisk *disk);
320 int bd_register_pending_holders(struct gendisk *disk);
322 static inline int bd_link_disk_holder(struct block_device *bdev,
323 struct gendisk *disk)
327 static inline void bd_unlink_disk_holder(struct block_device *bdev,
328 struct gendisk *disk)
331 static inline int bd_register_pending_holders(struct gendisk *disk)
335 #endif /* CONFIG_BLOCK_HOLDER_DEPRECATED */
337 dev_t part_devt(struct gendisk *disk, u8 partno);
338 void inc_diskseq(struct gendisk *disk);
339 dev_t blk_lookup_devt(const char *name, int partno);
340 void blk_request_module(dev_t devt);
342 void printk_all_partitions(void);
343 #else /* CONFIG_BLOCK */
344 static inline void printk_all_partitions(void)
347 #endif /* CONFIG_BLOCK */
349 #endif /* _LINUX_GENHD_H */