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 #define dev_to_part(device) container_of((device), struct hd_struct, __dev)
23 #define part_to_dev(part) (&((part)->__dev))
25 #define dev_to_disk(device) (dev_to_part(device)->bdev->bd_disk)
26 #define disk_to_dev(disk) (part_to_dev((disk)->part0->bd_part))
28 extern const struct device_type disk_type;
29 extern struct device_type part_type;
30 extern struct class block_class;
32 #define DISK_MAX_PARTS 256
33 #define DISK_NAME_LEN 32
35 #include <linux/major.h>
36 #include <linux/device.h>
37 #include <linux/smp.h>
38 #include <linux/string.h>
40 #include <linux/workqueue.h>
42 #define PARTITION_META_INFO_VOLNAMELTH 64
44 * Enough for the string representation of any kind of UUID plus NULL.
45 * EFI UUID is 36 characters. MSDOS UUID is 11 characters.
47 #define PARTITION_META_INFO_UUIDLTH (UUID_STRING_LEN + 1)
49 struct partition_meta_info {
50 char uuid[PARTITION_META_INFO_UUIDLTH];
51 u8 volname[PARTITION_META_INFO_VOLNAMELTH];
55 struct block_device *bdev;
61 * DOC: genhd capability flags
63 * ``GENHD_FL_REMOVABLE`` (0x0001): indicates that the block device
64 * gives access to removable media.
65 * When set, the device remains present even when media is not
67 * Must not be set for devices which are removed entirely when the
70 * ``GENHD_FL_CD`` (0x0008): the block device is a CD-ROM-style
72 * Affects responses to the ``CDROM_GET_CAPABILITY`` ioctl.
74 * ``GENHD_FL_UP`` (0x0010): indicates that the block device is "up",
75 * with a similar meaning to network interfaces.
77 * ``GENHD_FL_SUPPRESS_PARTITION_INFO`` (0x0020): don't include
78 * partition information in ``/proc/partitions`` or in the output of
79 * printk_all_partitions().
80 * Used for the null block device and some MMC devices.
82 * ``GENHD_FL_EXT_DEVT`` (0x0040): the driver supports extended
83 * dynamic ``dev_t``, i.e. it wants extended device numbers
84 * (``BLOCK_EXT_MAJOR``).
85 * This affects the maximum number of partitions.
87 * ``GENHD_FL_NATIVE_CAPACITY`` (0x0080): based on information in the
88 * partition table, the device's capacity has been extended to its
89 * native capacity; i.e. the device has hidden capacity used by one
90 * of the partitions (this is a flag used so that native capacity is
91 * only ever unlocked once).
93 * ``GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE`` (0x0100): event polling is
94 * blocked whenever a writer holds an exclusive lock.
96 * ``GENHD_FL_NO_PART_SCAN`` (0x0200): partition scanning is disabled.
97 * Used for loop devices in their default settings and some MMC
100 * ``GENHD_FL_HIDDEN`` (0x0400): the block device is hidden; it
101 * doesn't produce events, doesn't appear in sysfs, and doesn't have
102 * an associated ``bdev``.
103 * Implies ``GENHD_FL_SUPPRESS_PARTITION_INFO`` and
104 * ``GENHD_FL_NO_PART_SCAN``.
105 * Used for multipath devices.
107 #define GENHD_FL_REMOVABLE 0x0001
108 /* 2 is unused (used to be GENHD_FL_DRIVERFS) */
109 /* 4 is unused (used to be GENHD_FL_MEDIA_CHANGE_NOTIFY) */
110 #define GENHD_FL_CD 0x0008
111 #define GENHD_FL_UP 0x0010
112 #define GENHD_FL_SUPPRESS_PARTITION_INFO 0x0020
113 #define GENHD_FL_EXT_DEVT 0x0040
114 #define GENHD_FL_NATIVE_CAPACITY 0x0080
115 #define GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE 0x0100
116 #define GENHD_FL_NO_PART_SCAN 0x0200
117 #define GENHD_FL_HIDDEN 0x0400
120 DISK_EVENT_MEDIA_CHANGE = 1 << 0, /* media changed */
121 DISK_EVENT_EJECT_REQUEST = 1 << 1, /* eject requested */
125 /* Poll even if events_poll_msecs is unset */
126 DISK_EVENT_FLAG_POLL = 1 << 0,
127 /* Forward events to udev */
128 DISK_EVENT_FLAG_UEVENT = 1 << 1,
131 struct disk_part_tbl {
132 struct rcu_head rcu_head;
134 struct hd_struct __rcu *last_lookup;
135 struct hd_struct __rcu *part[];
141 struct blk_integrity {
142 const struct blk_integrity_profile *profile;
144 unsigned char tuple_size;
145 unsigned char interval_exp;
146 unsigned char tag_size;
150 /* major, first_minor and minors are input parameters only,
151 * don't use directly. Use disk_devt() and disk_max_parts().
153 int major; /* major number of driver */
155 int minors; /* maximum number of minors, =1 for
156 * disks that can't be partitioned. */
158 char disk_name[DISK_NAME_LEN]; /* name of major driver */
160 unsigned short events; /* supported events */
161 unsigned short event_flags; /* flags related to event processing */
163 /* Array of pointers to partitions indexed by partno.
164 * Protected with matching bdev lock but stat and other
165 * non-critical accesses use RCU. Always access through
168 struct disk_part_tbl __rcu *part_tbl;
169 struct block_device *part0;
171 const struct block_device_operations *fops;
172 struct request_queue *queue;
177 #define GD_NEED_PART_SCAN 0
178 struct kobject *slave_dir;
180 struct timer_rand_state *random;
181 atomic_t sync_io; /* RAID */
182 struct disk_events *ev;
183 #ifdef CONFIG_BLK_DEV_INTEGRITY
184 struct kobject integrity_kobj;
185 #endif /* CONFIG_BLK_DEV_INTEGRITY */
186 #if IS_ENABLED(CONFIG_CDROM)
187 struct cdrom_device_info *cdi;
190 struct badblocks *bb;
191 struct lockdep_map lockdep_map;
194 #if IS_REACHABLE(CONFIG_CDROM)
195 #define disk_to_cdi(disk) ((disk)->cdi)
197 #define disk_to_cdi(disk) NULL
200 static inline struct gendisk *part_to_disk(struct hd_struct *part)
204 return part->bdev->bd_disk;
207 static inline int disk_max_parts(struct gendisk *disk)
209 if (disk->flags & GENHD_FL_EXT_DEVT)
210 return DISK_MAX_PARTS;
214 static inline bool disk_part_scan_enabled(struct gendisk *disk)
216 return disk_max_parts(disk) > 1 &&
217 !(disk->flags & GENHD_FL_NO_PART_SCAN);
220 static inline dev_t disk_devt(struct gendisk *disk)
222 return MKDEV(disk->major, disk->first_minor);
225 static inline dev_t part_devt(struct hd_struct *part)
227 return part_to_dev(part)->devt;
230 extern struct hd_struct *disk_get_part(struct gendisk *disk, int partno);
232 static inline void disk_put_part(struct hd_struct *part)
235 put_device(part_to_dev(part));
239 * Smarter partition iterator without context limits.
241 #define DISK_PITER_REVERSE (1 << 0) /* iterate in the reverse direction */
242 #define DISK_PITER_INCL_EMPTY (1 << 1) /* include 0-sized parts */
243 #define DISK_PITER_INCL_PART0 (1 << 2) /* include partition 0 */
244 #define DISK_PITER_INCL_EMPTY_PART0 (1 << 3) /* include empty partition 0 */
246 struct disk_part_iter {
247 struct gendisk *disk;
248 struct hd_struct *part;
253 extern void disk_part_iter_init(struct disk_part_iter *piter,
254 struct gendisk *disk, unsigned int flags);
255 extern struct hd_struct *disk_part_iter_next(struct disk_part_iter *piter);
256 extern void disk_part_iter_exit(struct disk_part_iter *piter);
257 extern bool disk_has_partitions(struct gendisk *disk);
260 extern void device_add_disk(struct device *parent, struct gendisk *disk,
261 const struct attribute_group **groups);
262 static inline void add_disk(struct gendisk *disk)
264 device_add_disk(NULL, disk, NULL);
266 extern void device_add_disk_no_queue_reg(struct device *parent, struct gendisk *disk);
267 static inline void add_disk_no_queue_reg(struct gendisk *disk)
269 device_add_disk_no_queue_reg(NULL, disk);
272 extern void del_gendisk(struct gendisk *gp);
273 extern struct block_device *bdget_disk(struct gendisk *disk, int partno);
275 extern void set_disk_ro(struct gendisk *disk, int flag);
277 static inline int get_disk_ro(struct gendisk *disk)
279 return disk->part0->bd_read_only;
282 extern void disk_block_events(struct gendisk *disk);
283 extern void disk_unblock_events(struct gendisk *disk);
284 extern void disk_flush_events(struct gendisk *disk, unsigned int mask);
285 bool set_capacity_and_notify(struct gendisk *disk, sector_t size);
287 /* drivers/char/random.c */
288 extern void add_disk_randomness(struct gendisk *disk) __latent_entropy;
289 extern void rand_initialize_disk(struct gendisk *disk);
291 static inline sector_t get_start_sect(struct block_device *bdev)
293 return bdev->bd_start_sect;
296 static inline sector_t bdev_nr_sectors(struct block_device *bdev)
298 return i_size_read(bdev->bd_inode) >> 9;
301 static inline sector_t get_capacity(struct gendisk *disk)
303 return bdev_nr_sectors(disk->part0);
306 int bdev_disk_changed(struct block_device *bdev, bool invalidate);
307 int blk_add_partitions(struct gendisk *disk, struct block_device *bdev);
308 int blk_drop_partitions(struct block_device *bdev);
310 extern struct gendisk *__alloc_disk_node(int minors, int node_id);
311 extern void put_disk(struct gendisk *disk);
313 #define alloc_disk_node(minors, node_id) \
315 static struct lock_class_key __key; \
316 const char *__name; \
317 struct gendisk *__disk; \
319 __name = "(gendisk_completion)"#minors"("#node_id")"; \
321 __disk = __alloc_disk_node(minors, node_id); \
324 lockdep_init_map(&__disk->lockdep_map, __name, &__key, 0); \
329 #define alloc_disk(minors) alloc_disk_node(minors, NUMA_NO_NODE)
331 int __register_blkdev(unsigned int major, const char *name,
332 void (*probe)(dev_t devt));
333 #define register_blkdev(major, name) \
334 __register_blkdev(major, name, NULL)
335 void unregister_blkdev(unsigned int major, const char *name);
337 bool bdev_check_media_change(struct block_device *bdev);
338 int __invalidate_device(struct block_device *bdev, bool kill_dirty);
339 void set_capacity(struct gendisk *disk, sector_t size);
341 /* for drivers/char/raw.c: */
342 int blkdev_ioctl(struct block_device *, fmode_t, unsigned, unsigned long);
343 long compat_blkdev_ioctl(struct file *, unsigned, unsigned long);
346 int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk);
347 void bd_unlink_disk_holder(struct block_device *bdev, struct gendisk *disk);
349 static inline int bd_link_disk_holder(struct block_device *bdev,
350 struct gendisk *disk)
354 static inline void bd_unlink_disk_holder(struct block_device *bdev,
355 struct gendisk *disk)
358 #endif /* CONFIG_SYSFS */
360 extern struct rw_semaphore bdev_lookup_sem;
362 dev_t blk_lookup_devt(const char *name, int partno);
363 void blk_request_module(dev_t devt);
365 void printk_all_partitions(void);
366 #else /* CONFIG_BLOCK */
367 static inline void printk_all_partitions(void)
370 #endif /* CONFIG_BLOCK */
372 #endif /* _LINUX_GENHD_H */