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_disk(device) container_of((device), struct gendisk, part0.__dev)
23 #define dev_to_part(device) container_of((device), struct hd_struct, __dev)
24 #define disk_to_dev(disk) (&(disk)->part0.__dev)
25 #define part_to_dev(part) (&((part)->__dev))
27 extern const struct device_type disk_type;
28 extern struct device_type part_type;
29 extern struct class block_class;
31 #define DISK_MAX_PARTS 256
32 #define DISK_NAME_LEN 32
34 #include <linux/major.h>
35 #include <linux/device.h>
36 #include <linux/smp.h>
37 #include <linux/string.h>
39 #include <linux/workqueue.h>
41 #define PARTITION_META_INFO_VOLNAMELTH 64
43 * Enough for the string representation of any kind of UUID plus NULL.
44 * EFI UUID is 36 characters. MSDOS UUID is 11 characters.
46 #define PARTITION_META_INFO_UUIDLTH (UUID_STRING_LEN + 1)
48 struct partition_meta_info {
49 char uuid[PARTITION_META_INFO_UUIDLTH];
50 u8 volname[PARTITION_META_INFO_VOLNAMELTH];
56 * nr_sects is protected by sequence counter. One might extend a
57 * partition while IO is happening to it and update of nr_sects
58 * can be non-atomic on 32bit machines with 64bit sector_t.
61 #if BITS_PER_LONG==32 && defined(CONFIG_SMP)
62 seqcount_t nr_sects_seq;
65 struct disk_stats __percpu *dkstats;
66 struct percpu_ref ref;
69 struct kobject *holder_dir;
71 struct partition_meta_info *info;
72 #ifdef CONFIG_FAIL_MAKE_REQUEST
75 struct rcu_work rcu_work;
79 * DOC: genhd capability flags
81 * ``GENHD_FL_REMOVABLE`` (0x0001): indicates that the block device
82 * gives access to removable media.
83 * When set, the device remains present even when media is not
85 * Must not be set for devices which are removed entirely when the
88 * ``GENHD_FL_CD`` (0x0008): the block device is a CD-ROM-style
90 * Affects responses to the ``CDROM_GET_CAPABILITY`` ioctl.
92 * ``GENHD_FL_UP`` (0x0010): indicates that the block device is "up",
93 * with a similar meaning to network interfaces.
95 * ``GENHD_FL_SUPPRESS_PARTITION_INFO`` (0x0020): don't include
96 * partition information in ``/proc/partitions`` or in the output of
97 * printk_all_partitions().
98 * Used for the null block device and some MMC devices.
100 * ``GENHD_FL_EXT_DEVT`` (0x0040): the driver supports extended
101 * dynamic ``dev_t``, i.e. it wants extended device numbers
102 * (``BLOCK_EXT_MAJOR``).
103 * This affects the maximum number of partitions.
105 * ``GENHD_FL_NATIVE_CAPACITY`` (0x0080): based on information in the
106 * partition table, the device's capacity has been extended to its
107 * native capacity; i.e. the device has hidden capacity used by one
108 * of the partitions (this is a flag used so that native capacity is
109 * only ever unlocked once).
111 * ``GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE`` (0x0100): event polling is
112 * blocked whenever a writer holds an exclusive lock.
114 * ``GENHD_FL_NO_PART_SCAN`` (0x0200): partition scanning is disabled.
115 * Used for loop devices in their default settings and some MMC
118 * ``GENHD_FL_HIDDEN`` (0x0400): the block device is hidden; it
119 * doesn't produce events, doesn't appear in sysfs, and doesn't have
120 * an associated ``bdev``.
121 * Implies ``GENHD_FL_SUPPRESS_PARTITION_INFO`` and
122 * ``GENHD_FL_NO_PART_SCAN``.
123 * Used for multipath devices.
125 #define GENHD_FL_REMOVABLE 0x0001
126 /* 2 is unused (used to be GENHD_FL_DRIVERFS) */
127 /* 4 is unused (used to be GENHD_FL_MEDIA_CHANGE_NOTIFY) */
128 #define GENHD_FL_CD 0x0008
129 #define GENHD_FL_UP 0x0010
130 #define GENHD_FL_SUPPRESS_PARTITION_INFO 0x0020
131 #define GENHD_FL_EXT_DEVT 0x0040
132 #define GENHD_FL_NATIVE_CAPACITY 0x0080
133 #define GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE 0x0100
134 #define GENHD_FL_NO_PART_SCAN 0x0200
135 #define GENHD_FL_HIDDEN 0x0400
138 DISK_EVENT_MEDIA_CHANGE = 1 << 0, /* media changed */
139 DISK_EVENT_EJECT_REQUEST = 1 << 1, /* eject requested */
143 /* Poll even if events_poll_msecs is unset */
144 DISK_EVENT_FLAG_POLL = 1 << 0,
145 /* Forward events to udev */
146 DISK_EVENT_FLAG_UEVENT = 1 << 1,
149 struct disk_part_tbl {
150 struct rcu_head rcu_head;
152 struct hd_struct __rcu *last_lookup;
153 struct hd_struct __rcu *part[];
159 struct blk_integrity {
160 const struct blk_integrity_profile *profile;
162 unsigned char tuple_size;
163 unsigned char interval_exp;
164 unsigned char tag_size;
168 /* major, first_minor and minors are input parameters only,
169 * don't use directly. Use disk_devt() and disk_max_parts().
171 int major; /* major number of driver */
173 int minors; /* maximum number of minors, =1 for
174 * disks that can't be partitioned. */
176 char disk_name[DISK_NAME_LEN]; /* name of major driver */
178 unsigned short events; /* supported events */
179 unsigned short event_flags; /* flags related to event processing */
181 /* Array of pointers to partitions indexed by partno.
182 * Protected with matching bdev lock but stat and other
183 * non-critical accesses use RCU. Always access through
186 struct disk_part_tbl __rcu *part_tbl;
187 struct hd_struct part0;
189 const struct block_device_operations *fops;
190 struct request_queue *queue;
194 struct rw_semaphore lookup_sem;
195 struct kobject *slave_dir;
197 struct timer_rand_state *random;
198 atomic_t sync_io; /* RAID */
199 struct disk_events *ev;
200 #ifdef CONFIG_BLK_DEV_INTEGRITY
201 struct kobject integrity_kobj;
202 #endif /* CONFIG_BLK_DEV_INTEGRITY */
203 #if IS_ENABLED(CONFIG_CDROM)
204 struct cdrom_device_info *cdi;
207 struct badblocks *bb;
208 struct lockdep_map lockdep_map;
211 #if IS_REACHABLE(CONFIG_CDROM)
212 #define disk_to_cdi(disk) ((disk)->cdi)
214 #define disk_to_cdi(disk) NULL
217 static inline struct gendisk *part_to_disk(struct hd_struct *part)
221 return dev_to_disk(part_to_dev(part)->parent);
223 return dev_to_disk(part_to_dev(part));
228 static inline int disk_max_parts(struct gendisk *disk)
230 if (disk->flags & GENHD_FL_EXT_DEVT)
231 return DISK_MAX_PARTS;
235 static inline bool disk_part_scan_enabled(struct gendisk *disk)
237 return disk_max_parts(disk) > 1 &&
238 !(disk->flags & GENHD_FL_NO_PART_SCAN);
241 static inline dev_t disk_devt(struct gendisk *disk)
243 return MKDEV(disk->major, disk->first_minor);
246 static inline dev_t part_devt(struct hd_struct *part)
248 return part_to_dev(part)->devt;
251 extern struct hd_struct *__disk_get_part(struct gendisk *disk, int partno);
252 extern struct hd_struct *disk_get_part(struct gendisk *disk, int partno);
254 static inline void disk_put_part(struct hd_struct *part)
257 put_device(part_to_dev(part));
260 static inline void hd_sects_seq_init(struct hd_struct *p)
262 #if BITS_PER_LONG==32 && defined(CONFIG_SMP)
263 seqcount_init(&p->nr_sects_seq);
268 * Smarter partition iterator without context limits.
270 #define DISK_PITER_REVERSE (1 << 0) /* iterate in the reverse direction */
271 #define DISK_PITER_INCL_EMPTY (1 << 1) /* include 0-sized parts */
272 #define DISK_PITER_INCL_PART0 (1 << 2) /* include partition 0 */
273 #define DISK_PITER_INCL_EMPTY_PART0 (1 << 3) /* include empty partition 0 */
275 struct disk_part_iter {
276 struct gendisk *disk;
277 struct hd_struct *part;
282 extern void disk_part_iter_init(struct disk_part_iter *piter,
283 struct gendisk *disk, unsigned int flags);
284 extern struct hd_struct *disk_part_iter_next(struct disk_part_iter *piter);
285 extern void disk_part_iter_exit(struct disk_part_iter *piter);
286 extern bool disk_has_partitions(struct gendisk *disk);
289 extern void device_add_disk(struct device *parent, struct gendisk *disk,
290 const struct attribute_group **groups);
291 static inline void add_disk(struct gendisk *disk)
293 device_add_disk(NULL, disk, NULL);
295 extern void device_add_disk_no_queue_reg(struct device *parent, struct gendisk *disk);
296 static inline void add_disk_no_queue_reg(struct gendisk *disk)
298 device_add_disk_no_queue_reg(NULL, disk);
301 extern void del_gendisk(struct gendisk *gp);
302 extern struct gendisk *get_gendisk(dev_t dev, int *partno);
303 extern struct block_device *bdget_disk(struct gendisk *disk, int partno);
305 extern void set_device_ro(struct block_device *bdev, int flag);
306 extern void set_disk_ro(struct gendisk *disk, int flag);
308 static inline int get_disk_ro(struct gendisk *disk)
310 return disk->part0.policy;
313 extern void disk_block_events(struct gendisk *disk);
314 extern void disk_unblock_events(struct gendisk *disk);
315 extern void disk_flush_events(struct gendisk *disk, unsigned int mask);
316 void set_capacity_revalidate_and_notify(struct gendisk *disk, sector_t size,
319 /* drivers/char/random.c */
320 extern void add_disk_randomness(struct gendisk *disk) __latent_entropy;
321 extern void rand_initialize_disk(struct gendisk *disk);
323 static inline sector_t get_start_sect(struct block_device *bdev)
325 return bdev->bd_part->start_sect;
327 static inline sector_t get_capacity(struct gendisk *disk)
329 return disk->part0.nr_sects;
331 static inline void set_capacity(struct gendisk *disk, sector_t size)
333 disk->part0.nr_sects = size;
336 int bdev_disk_changed(struct block_device *bdev, bool invalidate);
337 int blk_add_partitions(struct gendisk *disk, struct block_device *bdev);
338 int blk_drop_partitions(struct block_device *bdev);
340 extern struct gendisk *__alloc_disk_node(int minors, int node_id);
341 extern struct kobject *get_disk_and_module(struct gendisk *disk);
342 extern void put_disk(struct gendisk *disk);
343 extern void put_disk_and_module(struct gendisk *disk);
344 extern void blk_register_region(dev_t devt, unsigned long range,
345 struct module *module,
346 struct kobject *(*probe)(dev_t, int *, void *),
347 int (*lock)(dev_t, void *),
349 extern void blk_unregister_region(dev_t devt, unsigned long range);
351 #define alloc_disk_node(minors, node_id) \
353 static struct lock_class_key __key; \
354 const char *__name; \
355 struct gendisk *__disk; \
357 __name = "(gendisk_completion)"#minors"("#node_id")"; \
359 __disk = __alloc_disk_node(minors, node_id); \
362 lockdep_init_map(&__disk->lockdep_map, __name, &__key, 0); \
367 #define alloc_disk(minors) alloc_disk_node(minors, NUMA_NO_NODE)
369 int register_blkdev(unsigned int major, const char *name);
370 void unregister_blkdev(unsigned int major, const char *name);
372 void revalidate_disk_size(struct gendisk *disk, bool verbose);
373 int check_disk_change(struct block_device *bdev);
374 bool bdev_check_media_change(struct block_device *bdev);
375 int __invalidate_device(struct block_device *bdev, bool kill_dirty);
376 void bd_set_nr_sectors(struct block_device *bdev, sector_t sectors);
378 /* for drivers/char/raw.c: */
379 int blkdev_ioctl(struct block_device *, fmode_t, unsigned, unsigned long);
380 long compat_blkdev_ioctl(struct file *, unsigned, unsigned long);
383 int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk);
384 void bd_unlink_disk_holder(struct block_device *bdev, struct gendisk *disk);
386 static inline int bd_link_disk_holder(struct block_device *bdev,
387 struct gendisk *disk)
391 static inline void bd_unlink_disk_holder(struct block_device *bdev,
392 struct gendisk *disk)
395 #endif /* CONFIG_SYSFS */
398 void printk_all_partitions(void);
399 dev_t blk_lookup_devt(const char *name, int partno);
400 #else /* CONFIG_BLOCK */
401 static inline void printk_all_partitions(void)
404 static inline dev_t blk_lookup_devt(const char *name, int partno)
406 dev_t devt = MKDEV(0, 0);
409 #endif /* CONFIG_BLOCK */
411 #endif /* _LINUX_GENHD_H */