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>
36 #define PARTITION_META_INFO_VOLNAMELTH 64
38 * Enough for the string representation of any kind of UUID plus NULL.
39 * EFI UUID is 36 characters. MSDOS UUID is 11 characters.
41 #define PARTITION_META_INFO_UUIDLTH (UUID_STRING_LEN + 1)
43 struct partition_meta_info {
44 char uuid[PARTITION_META_INFO_UUIDLTH];
45 u8 volname[PARTITION_META_INFO_VOLNAMELTH];
49 * DOC: genhd capability flags
51 * ``GENHD_FL_REMOVABLE`` (0x0001): indicates that the block device
52 * gives access to removable media.
53 * When set, the device remains present even when media is not
55 * Must not be set for devices which are removed entirely when the
58 * ``GENHD_FL_CD`` (0x0008): the block device is a CD-ROM-style
60 * Affects responses to the ``CDROM_GET_CAPABILITY`` ioctl.
62 * ``GENHD_FL_UP`` (0x0010): indicates that the block device is "up",
63 * with a similar meaning to network interfaces.
65 * ``GENHD_FL_SUPPRESS_PARTITION_INFO`` (0x0020): don't include
66 * partition information in ``/proc/partitions`` or in the output of
67 * printk_all_partitions().
68 * Used for the null block device and some MMC devices.
70 * ``GENHD_FL_EXT_DEVT`` (0x0040): the driver supports extended
71 * dynamic ``dev_t``, i.e. it wants extended device numbers
72 * (``BLOCK_EXT_MAJOR``).
73 * This affects the maximum number of partitions.
75 * ``GENHD_FL_NATIVE_CAPACITY`` (0x0080): based on information in the
76 * partition table, the device's capacity has been extended to its
77 * native capacity; i.e. the device has hidden capacity used by one
78 * of the partitions (this is a flag used so that native capacity is
79 * only ever unlocked once).
81 * ``GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE`` (0x0100): event polling is
82 * blocked whenever a writer holds an exclusive lock.
84 * ``GENHD_FL_NO_PART_SCAN`` (0x0200): partition scanning is disabled.
85 * Used for loop devices in their default settings and some MMC
88 * ``GENHD_FL_HIDDEN`` (0x0400): the block device is hidden; it
89 * doesn't produce events, doesn't appear in sysfs, and doesn't have
90 * an associated ``bdev``.
91 * Implies ``GENHD_FL_SUPPRESS_PARTITION_INFO`` and
92 * ``GENHD_FL_NO_PART_SCAN``.
93 * Used for multipath devices.
95 #define GENHD_FL_REMOVABLE 0x0001
96 /* 2 is unused (used to be GENHD_FL_DRIVERFS) */
97 /* 4 is unused (used to be GENHD_FL_MEDIA_CHANGE_NOTIFY) */
98 #define GENHD_FL_CD 0x0008
99 #define GENHD_FL_UP 0x0010
100 #define GENHD_FL_SUPPRESS_PARTITION_INFO 0x0020
101 #define GENHD_FL_EXT_DEVT 0x0040
102 #define GENHD_FL_NATIVE_CAPACITY 0x0080
103 #define GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE 0x0100
104 #define GENHD_FL_NO_PART_SCAN 0x0200
105 #define GENHD_FL_HIDDEN 0x0400
108 DISK_EVENT_MEDIA_CHANGE = 1 << 0, /* media changed */
109 DISK_EVENT_EJECT_REQUEST = 1 << 1, /* eject requested */
113 /* Poll even if events_poll_msecs is unset */
114 DISK_EVENT_FLAG_POLL = 1 << 0,
115 /* Forward events to udev */
116 DISK_EVENT_FLAG_UEVENT = 1 << 1,
119 struct disk_part_tbl {
120 struct rcu_head rcu_head;
122 struct block_device __rcu *last_lookup;
123 struct block_device __rcu *part[];
129 struct blk_integrity {
130 const struct blk_integrity_profile *profile;
132 unsigned char tuple_size;
133 unsigned char interval_exp;
134 unsigned char tag_size;
138 /* major, first_minor and minors are input parameters only,
139 * don't use directly. Use disk_devt() and disk_max_parts().
141 int major; /* major number of driver */
143 int minors; /* maximum number of minors, =1 for
144 * disks that can't be partitioned. */
146 char disk_name[DISK_NAME_LEN]; /* name of major driver */
148 unsigned short events; /* supported events */
149 unsigned short event_flags; /* flags related to event processing */
151 /* Array of pointers to partitions indexed by partno.
152 * Protected with matching bdev lock but stat and other
153 * non-critical accesses use RCU. Always access through
156 struct disk_part_tbl __rcu *part_tbl;
157 struct block_device *part0;
159 const struct block_device_operations *fops;
160 struct request_queue *queue;
165 #define GD_NEED_PART_SCAN 0
166 struct kobject *slave_dir;
168 struct timer_rand_state *random;
169 atomic_t sync_io; /* RAID */
170 struct disk_events *ev;
171 #ifdef CONFIG_BLK_DEV_INTEGRITY
172 struct kobject integrity_kobj;
173 #endif /* CONFIG_BLK_DEV_INTEGRITY */
174 #if IS_ENABLED(CONFIG_CDROM)
175 struct cdrom_device_info *cdi;
178 struct badblocks *bb;
179 struct lockdep_map lockdep_map;
183 * The gendisk is refcounted by the part0 block_device, and the bd_device
184 * therein is also used for device model presentation in sysfs.
186 #define dev_to_disk(device) \
187 (dev_to_bdev(device)->bd_disk)
188 #define disk_to_dev(disk) \
189 (&((disk)->part0->bd_device))
191 #if IS_REACHABLE(CONFIG_CDROM)
192 #define disk_to_cdi(disk) ((disk)->cdi)
194 #define disk_to_cdi(disk) NULL
197 static inline int disk_max_parts(struct gendisk *disk)
199 if (disk->flags & GENHD_FL_EXT_DEVT)
200 return DISK_MAX_PARTS;
204 static inline bool disk_part_scan_enabled(struct gendisk *disk)
206 return disk_max_parts(disk) > 1 &&
207 !(disk->flags & GENHD_FL_NO_PART_SCAN);
210 static inline dev_t disk_devt(struct gendisk *disk)
212 return MKDEV(disk->major, disk->first_minor);
216 * Smarter partition iterator without context limits.
218 #define DISK_PITER_REVERSE (1 << 0) /* iterate in the reverse direction */
219 #define DISK_PITER_INCL_EMPTY (1 << 1) /* include 0-sized parts */
220 #define DISK_PITER_INCL_PART0 (1 << 2) /* include partition 0 */
221 #define DISK_PITER_INCL_EMPTY_PART0 (1 << 3) /* include empty partition 0 */
223 struct disk_part_iter {
224 struct gendisk *disk;
225 struct block_device *part;
230 extern void disk_part_iter_init(struct disk_part_iter *piter,
231 struct gendisk *disk, unsigned int flags);
232 struct block_device *disk_part_iter_next(struct disk_part_iter *piter);
233 extern void disk_part_iter_exit(struct disk_part_iter *piter);
234 extern bool disk_has_partitions(struct gendisk *disk);
237 extern void device_add_disk(struct device *parent, struct gendisk *disk,
238 const struct attribute_group **groups);
239 static inline void add_disk(struct gendisk *disk)
241 device_add_disk(NULL, disk, NULL);
243 extern void device_add_disk_no_queue_reg(struct device *parent, struct gendisk *disk);
244 static inline void add_disk_no_queue_reg(struct gendisk *disk)
246 device_add_disk_no_queue_reg(NULL, disk);
249 extern void del_gendisk(struct gendisk *gp);
250 extern struct block_device *bdget_disk(struct gendisk *disk, int partno);
252 extern void set_disk_ro(struct gendisk *disk, int flag);
254 static inline int get_disk_ro(struct gendisk *disk)
256 return disk->part0->bd_read_only;
259 extern void disk_block_events(struct gendisk *disk);
260 extern void disk_unblock_events(struct gendisk *disk);
261 extern void disk_flush_events(struct gendisk *disk, unsigned int mask);
262 bool set_capacity_and_notify(struct gendisk *disk, sector_t size);
264 /* drivers/char/random.c */
265 extern void add_disk_randomness(struct gendisk *disk) __latent_entropy;
266 extern void rand_initialize_disk(struct gendisk *disk);
268 static inline sector_t get_start_sect(struct block_device *bdev)
270 return bdev->bd_start_sect;
273 static inline sector_t bdev_nr_sectors(struct block_device *bdev)
275 return i_size_read(bdev->bd_inode) >> 9;
278 static inline sector_t get_capacity(struct gendisk *disk)
280 return bdev_nr_sectors(disk->part0);
283 int bdev_disk_changed(struct block_device *bdev, bool invalidate);
284 int blk_add_partitions(struct gendisk *disk, struct block_device *bdev);
285 int blk_drop_partitions(struct block_device *bdev);
287 extern struct gendisk *__alloc_disk_node(int minors, int node_id);
288 extern void put_disk(struct gendisk *disk);
290 #define alloc_disk_node(minors, node_id) \
292 static struct lock_class_key __key; \
293 const char *__name; \
294 struct gendisk *__disk; \
296 __name = "(gendisk_completion)"#minors"("#node_id")"; \
298 __disk = __alloc_disk_node(minors, node_id); \
301 lockdep_init_map(&__disk->lockdep_map, __name, &__key, 0); \
306 #define alloc_disk(minors) alloc_disk_node(minors, NUMA_NO_NODE)
308 int __register_blkdev(unsigned int major, const char *name,
309 void (*probe)(dev_t devt));
310 #define register_blkdev(major, name) \
311 __register_blkdev(major, name, NULL)
312 void unregister_blkdev(unsigned int major, const char *name);
314 bool bdev_check_media_change(struct block_device *bdev);
315 int __invalidate_device(struct block_device *bdev, bool kill_dirty);
316 void set_capacity(struct gendisk *disk, sector_t size);
318 /* for drivers/char/raw.c: */
319 int blkdev_ioctl(struct block_device *, fmode_t, unsigned, unsigned long);
320 long compat_blkdev_ioctl(struct file *, unsigned, unsigned long);
323 int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk);
324 void bd_unlink_disk_holder(struct block_device *bdev, struct gendisk *disk);
326 static inline int bd_link_disk_holder(struct block_device *bdev,
327 struct gendisk *disk)
331 static inline void bd_unlink_disk_holder(struct block_device *bdev,
332 struct gendisk *disk)
335 #endif /* CONFIG_SYSFS */
337 extern struct rw_semaphore bdev_lookup_sem;
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 */