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>
24 #define dev_to_disk(device) container_of((device), struct gendisk, part0.__dev)
25 #define dev_to_part(device) container_of((device), struct hd_struct, __dev)
26 #define disk_to_dev(disk) (&(disk)->part0.__dev)
27 #define part_to_dev(part) (&((part)->__dev))
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];
57 * nr_sects is protected by sequence counter. One might extend a
58 * partition while IO is happening to it and update of nr_sects
59 * can be non-atomic on 32bit machines with 64bit sector_t.
62 #if BITS_PER_LONG==32 && defined(CONFIG_SMP)
63 seqcount_t nr_sects_seq;
66 struct disk_stats __percpu *dkstats;
67 struct percpu_ref ref;
69 sector_t alignment_offset;
70 unsigned int discard_alignment;
72 struct kobject *holder_dir;
74 struct partition_meta_info *info;
75 #ifdef CONFIG_FAIL_MAKE_REQUEST
78 struct rcu_work rcu_work;
82 * DOC: genhd capability flags
84 * ``GENHD_FL_REMOVABLE`` (0x0001): indicates that the block device
85 * gives access to removable media.
86 * When set, the device remains present even when media is not
88 * Must not be set for devices which are removed entirely when the
91 * ``GENHD_FL_CD`` (0x0008): the block device is a CD-ROM-style
93 * Affects responses to the ``CDROM_GET_CAPABILITY`` ioctl.
95 * ``GENHD_FL_UP`` (0x0010): indicates that the block device is "up",
96 * with a similar meaning to network interfaces.
98 * ``GENHD_FL_SUPPRESS_PARTITION_INFO`` (0x0020): don't include
99 * partition information in ``/proc/partitions`` or in the output of
100 * printk_all_partitions().
101 * Used for the null block device and some MMC devices.
103 * ``GENHD_FL_EXT_DEVT`` (0x0040): the driver supports extended
104 * dynamic ``dev_t``, i.e. it wants extended device numbers
105 * (``BLOCK_EXT_MAJOR``).
106 * This affects the maximum number of partitions.
108 * ``GENHD_FL_NATIVE_CAPACITY`` (0x0080): based on information in the
109 * partition table, the device's capacity has been extended to its
110 * native capacity; i.e. the device has hidden capacity used by one
111 * of the partitions (this is a flag used so that native capacity is
112 * only ever unlocked once).
114 * ``GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE`` (0x0100): event polling is
115 * blocked whenever a writer holds an exclusive lock.
117 * ``GENHD_FL_NO_PART_SCAN`` (0x0200): partition scanning is disabled.
118 * Used for loop devices in their default settings and some MMC
121 * ``GENHD_FL_HIDDEN`` (0x0400): the block device is hidden; it
122 * doesn't produce events, doesn't appear in sysfs, and doesn't have
123 * an associated ``bdev``.
124 * Implies ``GENHD_FL_SUPPRESS_PARTITION_INFO`` and
125 * ``GENHD_FL_NO_PART_SCAN``.
126 * Used for multipath devices.
128 #define GENHD_FL_REMOVABLE 0x0001
129 /* 2 is unused (used to be GENHD_FL_DRIVERFS) */
130 /* 4 is unused (used to be GENHD_FL_MEDIA_CHANGE_NOTIFY) */
131 #define GENHD_FL_CD 0x0008
132 #define GENHD_FL_UP 0x0010
133 #define GENHD_FL_SUPPRESS_PARTITION_INFO 0x0020
134 #define GENHD_FL_EXT_DEVT 0x0040
135 #define GENHD_FL_NATIVE_CAPACITY 0x0080
136 #define GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE 0x0100
137 #define GENHD_FL_NO_PART_SCAN 0x0200
138 #define GENHD_FL_HIDDEN 0x0400
141 DISK_EVENT_MEDIA_CHANGE = 1 << 0, /* media changed */
142 DISK_EVENT_EJECT_REQUEST = 1 << 1, /* eject requested */
146 /* Poll even if events_poll_msecs is unset */
147 DISK_EVENT_FLAG_POLL = 1 << 0,
148 /* Forward events to udev */
149 DISK_EVENT_FLAG_UEVENT = 1 << 1,
152 struct disk_part_tbl {
153 struct rcu_head rcu_head;
155 struct hd_struct __rcu *last_lookup;
156 struct hd_struct __rcu *part[];
162 struct blk_integrity {
163 const struct blk_integrity_profile *profile;
165 unsigned char tuple_size;
166 unsigned char interval_exp;
167 unsigned char tag_size;
171 /* major, first_minor and minors are input parameters only,
172 * don't use directly. Use disk_devt() and disk_max_parts().
174 int major; /* major number of driver */
176 int minors; /* maximum number of minors, =1 for
177 * disks that can't be partitioned. */
179 char disk_name[DISK_NAME_LEN]; /* name of major driver */
181 unsigned short events; /* supported events */
182 unsigned short event_flags; /* flags related to event processing */
184 /* Array of pointers to partitions indexed by partno.
185 * Protected with matching bdev lock but stat and other
186 * non-critical accesses use RCU. Always access through
189 struct disk_part_tbl __rcu *part_tbl;
190 struct hd_struct part0;
192 const struct block_device_operations *fops;
193 struct request_queue *queue;
197 struct rw_semaphore lookup_sem;
198 struct kobject *slave_dir;
200 struct timer_rand_state *random;
201 atomic_t sync_io; /* RAID */
202 struct disk_events *ev;
203 #ifdef CONFIG_BLK_DEV_INTEGRITY
204 struct kobject integrity_kobj;
205 #endif /* CONFIG_BLK_DEV_INTEGRITY */
206 #if IS_ENABLED(CONFIG_CDROM)
207 struct cdrom_device_info *cdi;
210 struct badblocks *bb;
211 struct lockdep_map lockdep_map;
214 #if IS_REACHABLE(CONFIG_CDROM)
215 #define disk_to_cdi(disk) ((disk)->cdi)
217 #define disk_to_cdi(disk) NULL
220 static inline struct gendisk *part_to_disk(struct hd_struct *part)
224 return dev_to_disk(part_to_dev(part)->parent);
226 return dev_to_disk(part_to_dev(part));
231 static inline int disk_max_parts(struct gendisk *disk)
233 if (disk->flags & GENHD_FL_EXT_DEVT)
234 return DISK_MAX_PARTS;
238 static inline bool disk_part_scan_enabled(struct gendisk *disk)
240 return disk_max_parts(disk) > 1 &&
241 !(disk->flags & GENHD_FL_NO_PART_SCAN);
244 static inline dev_t disk_devt(struct gendisk *disk)
246 return MKDEV(disk->major, disk->first_minor);
249 static inline dev_t part_devt(struct hd_struct *part)
251 return part_to_dev(part)->devt;
254 extern struct hd_struct *__disk_get_part(struct gendisk *disk, int partno);
255 extern struct hd_struct *disk_get_part(struct gendisk *disk, int partno);
257 static inline void disk_put_part(struct hd_struct *part)
260 put_device(part_to_dev(part));
263 static inline void hd_sects_seq_init(struct hd_struct *p)
265 #if BITS_PER_LONG==32 && defined(CONFIG_SMP)
266 seqcount_init(&p->nr_sects_seq);
271 * Smarter partition iterator without context limits.
273 #define DISK_PITER_REVERSE (1 << 0) /* iterate in the reverse direction */
274 #define DISK_PITER_INCL_EMPTY (1 << 1) /* include 0-sized parts */
275 #define DISK_PITER_INCL_PART0 (1 << 2) /* include partition 0 */
276 #define DISK_PITER_INCL_EMPTY_PART0 (1 << 3) /* include empty partition 0 */
278 struct disk_part_iter {
279 struct gendisk *disk;
280 struct hd_struct *part;
285 extern void disk_part_iter_init(struct disk_part_iter *piter,
286 struct gendisk *disk, unsigned int flags);
287 extern struct hd_struct *disk_part_iter_next(struct disk_part_iter *piter);
288 extern void disk_part_iter_exit(struct disk_part_iter *piter);
289 extern bool disk_has_partitions(struct gendisk *disk);
292 extern void device_add_disk(struct device *parent, struct gendisk *disk,
293 const struct attribute_group **groups);
294 static inline void add_disk(struct gendisk *disk)
296 device_add_disk(NULL, disk, NULL);
298 extern void device_add_disk_no_queue_reg(struct device *parent, struct gendisk *disk);
299 static inline void add_disk_no_queue_reg(struct gendisk *disk)
301 device_add_disk_no_queue_reg(NULL, disk);
304 extern void del_gendisk(struct gendisk *gp);
305 extern struct gendisk *get_gendisk(dev_t dev, int *partno);
306 extern struct block_device *bdget_disk(struct gendisk *disk, int partno);
308 extern void set_device_ro(struct block_device *bdev, int flag);
309 extern void set_disk_ro(struct gendisk *disk, int flag);
311 static inline int get_disk_ro(struct gendisk *disk)
313 return disk->part0.policy;
316 extern void disk_block_events(struct gendisk *disk);
317 extern void disk_unblock_events(struct gendisk *disk);
318 extern void disk_flush_events(struct gendisk *disk, unsigned int mask);
319 extern void set_capacity_revalidate_and_notify(struct gendisk *disk,
320 sector_t size, bool revalidate);
321 extern unsigned int disk_clear_events(struct gendisk *disk, unsigned int mask);
323 /* drivers/char/random.c */
324 extern void add_disk_randomness(struct gendisk *disk) __latent_entropy;
325 extern void rand_initialize_disk(struct gendisk *disk);
327 static inline sector_t get_start_sect(struct block_device *bdev)
329 return bdev->bd_part->start_sect;
331 static inline sector_t get_capacity(struct gendisk *disk)
333 return disk->part0.nr_sects;
335 static inline void set_capacity(struct gendisk *disk, sector_t size)
337 disk->part0.nr_sects = size;
340 extern dev_t blk_lookup_devt(const char *name, int partno);
342 int bdev_disk_changed(struct block_device *bdev, bool invalidate);
343 int blk_add_partitions(struct gendisk *disk, struct block_device *bdev);
344 int blk_drop_partitions(struct block_device *bdev);
345 extern void printk_all_partitions(void);
347 extern struct gendisk *__alloc_disk_node(int minors, int node_id);
348 extern struct kobject *get_disk_and_module(struct gendisk *disk);
349 extern void put_disk(struct gendisk *disk);
350 extern void put_disk_and_module(struct gendisk *disk);
351 extern void blk_register_region(dev_t devt, unsigned long range,
352 struct module *module,
353 struct kobject *(*probe)(dev_t, int *, void *),
354 int (*lock)(dev_t, void *),
356 extern void blk_unregister_region(dev_t devt, unsigned long range);
358 #define alloc_disk_node(minors, node_id) \
360 static struct lock_class_key __key; \
361 const char *__name; \
362 struct gendisk *__disk; \
364 __name = "(gendisk_completion)"#minors"("#node_id")"; \
366 __disk = __alloc_disk_node(minors, node_id); \
369 lockdep_init_map(&__disk->lockdep_map, __name, &__key, 0); \
374 #define alloc_disk(minors) alloc_disk_node(minors, NUMA_NO_NODE)
376 #else /* CONFIG_BLOCK */
378 static inline void printk_all_partitions(void) { }
380 static inline dev_t blk_lookup_devt(const char *name, int partno)
382 dev_t devt = MKDEV(0, 0);
385 #endif /* CONFIG_BLOCK */
387 #endif /* _LINUX_GENHD_H */