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;
68 sector_t alignment_offset;
69 unsigned int discard_alignment;
71 struct kobject *holder_dir;
73 struct partition_meta_info *info;
74 #ifdef CONFIG_FAIL_MAKE_REQUEST
77 struct rcu_work rcu_work;
81 * DOC: genhd capability flags
83 * ``GENHD_FL_REMOVABLE`` (0x0001): indicates that the block device
84 * gives access to removable media.
85 * When set, the device remains present even when media is not
87 * Must not be set for devices which are removed entirely when the
90 * ``GENHD_FL_CD`` (0x0008): the block device is a CD-ROM-style
92 * Affects responses to the ``CDROM_GET_CAPABILITY`` ioctl.
94 * ``GENHD_FL_UP`` (0x0010): indicates that the block device is "up",
95 * with a similar meaning to network interfaces.
97 * ``GENHD_FL_SUPPRESS_PARTITION_INFO`` (0x0020): don't include
98 * partition information in ``/proc/partitions`` or in the output of
99 * printk_all_partitions().
100 * Used for the null block device and some MMC devices.
102 * ``GENHD_FL_EXT_DEVT`` (0x0040): the driver supports extended
103 * dynamic ``dev_t``, i.e. it wants extended device numbers
104 * (``BLOCK_EXT_MAJOR``).
105 * This affects the maximum number of partitions.
107 * ``GENHD_FL_NATIVE_CAPACITY`` (0x0080): based on information in the
108 * partition table, the device's capacity has been extended to its
109 * native capacity; i.e. the device has hidden capacity used by one
110 * of the partitions (this is a flag used so that native capacity is
111 * only ever unlocked once).
113 * ``GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE`` (0x0100): event polling is
114 * blocked whenever a writer holds an exclusive lock.
116 * ``GENHD_FL_NO_PART_SCAN`` (0x0200): partition scanning is disabled.
117 * Used for loop devices in their default settings and some MMC
120 * ``GENHD_FL_HIDDEN`` (0x0400): the block device is hidden; it
121 * doesn't produce events, doesn't appear in sysfs, and doesn't have
122 * an associated ``bdev``.
123 * Implies ``GENHD_FL_SUPPRESS_PARTITION_INFO`` and
124 * ``GENHD_FL_NO_PART_SCAN``.
125 * Used for multipath devices.
127 #define GENHD_FL_REMOVABLE 0x0001
128 /* 2 is unused (used to be GENHD_FL_DRIVERFS) */
129 /* 4 is unused (used to be GENHD_FL_MEDIA_CHANGE_NOTIFY) */
130 #define GENHD_FL_CD 0x0008
131 #define GENHD_FL_UP 0x0010
132 #define GENHD_FL_SUPPRESS_PARTITION_INFO 0x0020
133 #define GENHD_FL_EXT_DEVT 0x0040
134 #define GENHD_FL_NATIVE_CAPACITY 0x0080
135 #define GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE 0x0100
136 #define GENHD_FL_NO_PART_SCAN 0x0200
137 #define GENHD_FL_HIDDEN 0x0400
140 DISK_EVENT_MEDIA_CHANGE = 1 << 0, /* media changed */
141 DISK_EVENT_EJECT_REQUEST = 1 << 1, /* eject requested */
145 /* Poll even if events_poll_msecs is unset */
146 DISK_EVENT_FLAG_POLL = 1 << 0,
147 /* Forward events to udev */
148 DISK_EVENT_FLAG_UEVENT = 1 << 1,
151 struct disk_part_tbl {
152 struct rcu_head rcu_head;
154 struct hd_struct __rcu *last_lookup;
155 struct hd_struct __rcu *part[];
161 struct blk_integrity {
162 const struct blk_integrity_profile *profile;
164 unsigned char tuple_size;
165 unsigned char interval_exp;
166 unsigned char tag_size;
170 /* major, first_minor and minors are input parameters only,
171 * don't use directly. Use disk_devt() and disk_max_parts().
173 int major; /* major number of driver */
175 int minors; /* maximum number of minors, =1 for
176 * disks that can't be partitioned. */
178 char disk_name[DISK_NAME_LEN]; /* name of major driver */
180 unsigned short events; /* supported events */
181 unsigned short event_flags; /* flags related to event processing */
183 /* Array of pointers to partitions indexed by partno.
184 * Protected with matching bdev lock but stat and other
185 * non-critical accesses use RCU. Always access through
188 struct disk_part_tbl __rcu *part_tbl;
189 struct hd_struct part0;
191 const struct block_device_operations *fops;
192 struct request_queue *queue;
196 struct rw_semaphore lookup_sem;
197 struct kobject *slave_dir;
199 struct timer_rand_state *random;
200 atomic_t sync_io; /* RAID */
201 struct disk_events *ev;
202 #ifdef CONFIG_BLK_DEV_INTEGRITY
203 struct kobject integrity_kobj;
204 #endif /* CONFIG_BLK_DEV_INTEGRITY */
205 #if IS_ENABLED(CONFIG_CDROM)
206 struct cdrom_device_info *cdi;
209 struct badblocks *bb;
210 struct lockdep_map lockdep_map;
213 #if IS_REACHABLE(CONFIG_CDROM)
214 #define disk_to_cdi(disk) ((disk)->cdi)
216 #define disk_to_cdi(disk) NULL
219 static inline struct gendisk *part_to_disk(struct hd_struct *part)
223 return dev_to_disk(part_to_dev(part)->parent);
225 return dev_to_disk(part_to_dev(part));
230 static inline int disk_max_parts(struct gendisk *disk)
232 if (disk->flags & GENHD_FL_EXT_DEVT)
233 return DISK_MAX_PARTS;
237 static inline bool disk_part_scan_enabled(struct gendisk *disk)
239 return disk_max_parts(disk) > 1 &&
240 !(disk->flags & GENHD_FL_NO_PART_SCAN);
243 static inline dev_t disk_devt(struct gendisk *disk)
245 return MKDEV(disk->major, disk->first_minor);
248 static inline dev_t part_devt(struct hd_struct *part)
250 return part_to_dev(part)->devt;
253 extern struct hd_struct *__disk_get_part(struct gendisk *disk, int partno);
254 extern struct hd_struct *disk_get_part(struct gendisk *disk, int partno);
256 static inline void disk_put_part(struct hd_struct *part)
259 put_device(part_to_dev(part));
262 static inline void hd_sects_seq_init(struct hd_struct *p)
264 #if BITS_PER_LONG==32 && defined(CONFIG_SMP)
265 seqcount_init(&p->nr_sects_seq);
270 * Smarter partition iterator without context limits.
272 #define DISK_PITER_REVERSE (1 << 0) /* iterate in the reverse direction */
273 #define DISK_PITER_INCL_EMPTY (1 << 1) /* include 0-sized parts */
274 #define DISK_PITER_INCL_PART0 (1 << 2) /* include partition 0 */
275 #define DISK_PITER_INCL_EMPTY_PART0 (1 << 3) /* include empty partition 0 */
277 struct disk_part_iter {
278 struct gendisk *disk;
279 struct hd_struct *part;
284 extern void disk_part_iter_init(struct disk_part_iter *piter,
285 struct gendisk *disk, unsigned int flags);
286 extern struct hd_struct *disk_part_iter_next(struct disk_part_iter *piter);
287 extern void disk_part_iter_exit(struct disk_part_iter *piter);
288 extern bool disk_has_partitions(struct gendisk *disk);
291 extern void device_add_disk(struct device *parent, struct gendisk *disk,
292 const struct attribute_group **groups);
293 static inline void add_disk(struct gendisk *disk)
295 device_add_disk(NULL, disk, NULL);
297 extern void device_add_disk_no_queue_reg(struct device *parent, struct gendisk *disk);
298 static inline void add_disk_no_queue_reg(struct gendisk *disk)
300 device_add_disk_no_queue_reg(NULL, disk);
303 extern void del_gendisk(struct gendisk *gp);
304 extern struct gendisk *get_gendisk(dev_t dev, int *partno);
305 extern struct block_device *bdget_disk(struct gendisk *disk, int partno);
307 extern void set_device_ro(struct block_device *bdev, int flag);
308 extern void set_disk_ro(struct gendisk *disk, int flag);
310 static inline int get_disk_ro(struct gendisk *disk)
312 return disk->part0.policy;
315 extern void disk_block_events(struct gendisk *disk);
316 extern void disk_unblock_events(struct gendisk *disk);
317 extern void disk_flush_events(struct gendisk *disk, unsigned int mask);
318 extern void set_capacity_revalidate_and_notify(struct gendisk *disk,
319 sector_t size, bool revalidate);
320 extern unsigned int disk_clear_events(struct gendisk *disk, unsigned int mask);
322 /* drivers/char/random.c */
323 extern void add_disk_randomness(struct gendisk *disk) __latent_entropy;
324 extern void rand_initialize_disk(struct gendisk *disk);
326 static inline sector_t get_start_sect(struct block_device *bdev)
328 return bdev->bd_part->start_sect;
330 static inline sector_t get_capacity(struct gendisk *disk)
332 return disk->part0.nr_sects;
334 static inline void set_capacity(struct gendisk *disk, sector_t size)
336 disk->part0.nr_sects = size;
339 int bdev_disk_changed(struct block_device *bdev, bool invalidate);
340 int blk_add_partitions(struct gendisk *disk, struct block_device *bdev);
341 int blk_drop_partitions(struct block_device *bdev);
343 extern struct gendisk *__alloc_disk_node(int minors, int node_id);
344 extern struct kobject *get_disk_and_module(struct gendisk *disk);
345 extern void put_disk(struct gendisk *disk);
346 extern void put_disk_and_module(struct gendisk *disk);
347 extern void blk_register_region(dev_t devt, unsigned long range,
348 struct module *module,
349 struct kobject *(*probe)(dev_t, int *, void *),
350 int (*lock)(dev_t, void *),
352 extern void blk_unregister_region(dev_t devt, unsigned long range);
354 #define alloc_disk_node(minors, node_id) \
356 static struct lock_class_key __key; \
357 const char *__name; \
358 struct gendisk *__disk; \
360 __name = "(gendisk_completion)"#minors"("#node_id")"; \
362 __disk = __alloc_disk_node(minors, node_id); \
365 lockdep_init_map(&__disk->lockdep_map, __name, &__key, 0); \
370 #define alloc_disk(minors) alloc_disk_node(minors, NUMA_NO_NODE)
372 int register_blkdev(unsigned int major, const char *name);
373 void unregister_blkdev(unsigned int major, const char *name);
375 int revalidate_disk(struct gendisk *disk);
376 int check_disk_change(struct block_device *bdev);
377 int __invalidate_device(struct block_device *bdev, bool kill_dirty);
378 void bd_set_size(struct block_device *bdev, loff_t size);
380 /* for drivers/char/raw.c: */
381 int blkdev_ioctl(struct block_device *, fmode_t, unsigned, unsigned long);
382 long compat_blkdev_ioctl(struct file *, unsigned, unsigned long);
385 int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk);
386 void bd_unlink_disk_holder(struct block_device *bdev, struct gendisk *disk);
388 static inline int bd_link_disk_holder(struct block_device *bdev,
389 struct gendisk *disk)
393 static inline void bd_unlink_disk_holder(struct block_device *bdev,
394 struct gendisk *disk)
397 #endif /* CONFIG_SYSFS */
400 void printk_all_partitions(void);
401 dev_t blk_lookup_devt(const char *name, int partno);
402 #else /* CONFIG_BLOCK */
403 static inline void printk_all_partitions(void)
406 static inline dev_t blk_lookup_devt(const char *name, int partno)
408 dev_t devt = MKDEV(0, 0);
411 #endif /* CONFIG_BLOCK */
413 #endif /* _LINUX_GENHD_H */