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>
43 u64 nsecs[NR_STAT_GROUPS];
44 unsigned long sectors[NR_STAT_GROUPS];
45 unsigned long ios[NR_STAT_GROUPS];
46 unsigned long merges[NR_STAT_GROUPS];
47 unsigned long io_ticks;
51 #define PARTITION_META_INFO_VOLNAMELTH 64
53 * Enough for the string representation of any kind of UUID plus NULL.
54 * EFI UUID is 36 characters. MSDOS UUID is 11 characters.
56 #define PARTITION_META_INFO_UUIDLTH (UUID_STRING_LEN + 1)
58 struct partition_meta_info {
59 char uuid[PARTITION_META_INFO_UUIDLTH];
60 u8 volname[PARTITION_META_INFO_VOLNAMELTH];
66 * nr_sects is protected by sequence counter. One might extend a
67 * partition while IO is happening to it and update of nr_sects
68 * can be non-atomic on 32bit machines with 64bit sector_t.
71 #if BITS_PER_LONG==32 && defined(CONFIG_SMP)
72 seqcount_t nr_sects_seq;
74 sector_t alignment_offset;
75 unsigned int discard_alignment;
77 struct kobject *holder_dir;
79 struct partition_meta_info *info;
80 #ifdef CONFIG_FAIL_MAKE_REQUEST
85 struct disk_stats __percpu *dkstats;
87 struct disk_stats dkstats;
89 struct percpu_ref ref;
90 struct rcu_work rcu_work;
94 * DOC: genhd capability flags
96 * ``GENHD_FL_REMOVABLE`` (0x0001): indicates that the block device
97 * gives access to removable media.
98 * When set, the device remains present even when media is not
100 * Must not be set for devices which are removed entirely when the
103 * ``GENHD_FL_CD`` (0x0008): the block device is a CD-ROM-style
105 * Affects responses to the ``CDROM_GET_CAPABILITY`` ioctl.
107 * ``GENHD_FL_UP`` (0x0010): indicates that the block device is "up",
108 * with a similar meaning to network interfaces.
110 * ``GENHD_FL_SUPPRESS_PARTITION_INFO`` (0x0020): don't include
111 * partition information in ``/proc/partitions`` or in the output of
112 * printk_all_partitions().
113 * Used for the null block device and some MMC devices.
115 * ``GENHD_FL_EXT_DEVT`` (0x0040): the driver supports extended
116 * dynamic ``dev_t``, i.e. it wants extended device numbers
117 * (``BLOCK_EXT_MAJOR``).
118 * This affects the maximum number of partitions.
120 * ``GENHD_FL_NATIVE_CAPACITY`` (0x0080): based on information in the
121 * partition table, the device's capacity has been extended to its
122 * native capacity; i.e. the device has hidden capacity used by one
123 * of the partitions (this is a flag used so that native capacity is
124 * only ever unlocked once).
126 * ``GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE`` (0x0100): event polling is
127 * blocked whenever a writer holds an exclusive lock.
129 * ``GENHD_FL_NO_PART_SCAN`` (0x0200): partition scanning is disabled.
130 * Used for loop devices in their default settings and some MMC
133 * ``GENHD_FL_HIDDEN`` (0x0400): the block device is hidden; it
134 * doesn't produce events, doesn't appear in sysfs, and doesn't have
135 * an associated ``bdev``.
136 * Implies ``GENHD_FL_SUPPRESS_PARTITION_INFO`` and
137 * ``GENHD_FL_NO_PART_SCAN``.
138 * Used for multipath devices.
140 #define GENHD_FL_REMOVABLE 0x0001
141 /* 2 is unused (used to be GENHD_FL_DRIVERFS) */
142 /* 4 is unused (used to be GENHD_FL_MEDIA_CHANGE_NOTIFY) */
143 #define GENHD_FL_CD 0x0008
144 #define GENHD_FL_UP 0x0010
145 #define GENHD_FL_SUPPRESS_PARTITION_INFO 0x0020
146 #define GENHD_FL_EXT_DEVT 0x0040
147 #define GENHD_FL_NATIVE_CAPACITY 0x0080
148 #define GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE 0x0100
149 #define GENHD_FL_NO_PART_SCAN 0x0200
150 #define GENHD_FL_HIDDEN 0x0400
153 DISK_EVENT_MEDIA_CHANGE = 1 << 0, /* media changed */
154 DISK_EVENT_EJECT_REQUEST = 1 << 1, /* eject requested */
158 /* Poll even if events_poll_msecs is unset */
159 DISK_EVENT_FLAG_POLL = 1 << 0,
160 /* Forward events to udev */
161 DISK_EVENT_FLAG_UEVENT = 1 << 1,
164 struct disk_part_tbl {
165 struct rcu_head rcu_head;
167 struct hd_struct __rcu *last_lookup;
168 struct hd_struct __rcu *part[];
174 #if defined(CONFIG_BLK_DEV_INTEGRITY)
176 struct blk_integrity {
177 const struct blk_integrity_profile *profile;
179 unsigned char tuple_size;
180 unsigned char interval_exp;
181 unsigned char tag_size;
184 #endif /* CONFIG_BLK_DEV_INTEGRITY */
187 /* major, first_minor and minors are input parameters only,
188 * don't use directly. Use disk_devt() and disk_max_parts().
190 int major; /* major number of driver */
192 int minors; /* maximum number of minors, =1 for
193 * disks that can't be partitioned. */
195 char disk_name[DISK_NAME_LEN]; /* name of major driver */
197 unsigned short events; /* supported events */
198 unsigned short event_flags; /* flags related to event processing */
200 /* Array of pointers to partitions indexed by partno.
201 * Protected with matching bdev lock but stat and other
202 * non-critical accesses use RCU. Always access through
205 struct disk_part_tbl __rcu *part_tbl;
206 struct hd_struct part0;
208 const struct block_device_operations *fops;
209 struct request_queue *queue;
213 struct rw_semaphore lookup_sem;
214 struct kobject *slave_dir;
216 struct timer_rand_state *random;
217 atomic_t sync_io; /* RAID */
218 struct disk_events *ev;
219 #ifdef CONFIG_BLK_DEV_INTEGRITY
220 struct kobject integrity_kobj;
221 #endif /* CONFIG_BLK_DEV_INTEGRITY */
222 #if IS_ENABLED(CONFIG_CDROM)
223 struct cdrom_device_info *cdi;
226 struct badblocks *bb;
227 struct lockdep_map lockdep_map;
230 #if IS_REACHABLE(CONFIG_CDROM)
231 #define disk_to_cdi(disk) ((disk)->cdi)
233 #define disk_to_cdi(disk) NULL
236 static inline struct gendisk *part_to_disk(struct hd_struct *part)
240 return dev_to_disk(part_to_dev(part)->parent);
242 return dev_to_disk(part_to_dev(part));
247 static inline int disk_max_parts(struct gendisk *disk)
249 if (disk->flags & GENHD_FL_EXT_DEVT)
250 return DISK_MAX_PARTS;
254 static inline bool disk_part_scan_enabled(struct gendisk *disk)
256 return disk_max_parts(disk) > 1 &&
257 !(disk->flags & GENHD_FL_NO_PART_SCAN);
260 static inline dev_t disk_devt(struct gendisk *disk)
262 return MKDEV(disk->major, disk->first_minor);
265 static inline dev_t part_devt(struct hd_struct *part)
267 return part_to_dev(part)->devt;
270 extern struct hd_struct *__disk_get_part(struct gendisk *disk, int partno);
271 extern struct hd_struct *disk_get_part(struct gendisk *disk, int partno);
273 static inline void disk_put_part(struct hd_struct *part)
276 put_device(part_to_dev(part));
279 static inline void hd_sects_seq_init(struct hd_struct *p)
281 #if BITS_PER_LONG==32 && defined(CONFIG_SMP)
282 seqcount_init(&p->nr_sects_seq);
287 * Smarter partition iterator without context limits.
289 #define DISK_PITER_REVERSE (1 << 0) /* iterate in the reverse direction */
290 #define DISK_PITER_INCL_EMPTY (1 << 1) /* include 0-sized parts */
291 #define DISK_PITER_INCL_PART0 (1 << 2) /* include partition 0 */
292 #define DISK_PITER_INCL_EMPTY_PART0 (1 << 3) /* include empty partition 0 */
294 struct disk_part_iter {
295 struct gendisk *disk;
296 struct hd_struct *part;
301 extern void disk_part_iter_init(struct disk_part_iter *piter,
302 struct gendisk *disk, unsigned int flags);
303 extern struct hd_struct *disk_part_iter_next(struct disk_part_iter *piter);
304 extern void disk_part_iter_exit(struct disk_part_iter *piter);
305 extern bool disk_has_partitions(struct gendisk *disk);
308 extern void device_add_disk(struct device *parent, struct gendisk *disk,
309 const struct attribute_group **groups);
310 static inline void add_disk(struct gendisk *disk)
312 device_add_disk(NULL, disk, NULL);
314 extern void device_add_disk_no_queue_reg(struct device *parent, struct gendisk *disk);
315 static inline void add_disk_no_queue_reg(struct gendisk *disk)
317 device_add_disk_no_queue_reg(NULL, disk);
320 extern void del_gendisk(struct gendisk *gp);
321 extern struct gendisk *get_gendisk(dev_t dev, int *partno);
322 extern struct block_device *bdget_disk(struct gendisk *disk, int partno);
324 extern void set_device_ro(struct block_device *bdev, int flag);
325 extern void set_disk_ro(struct gendisk *disk, int flag);
327 static inline int get_disk_ro(struct gendisk *disk)
329 return disk->part0.policy;
332 extern void disk_block_events(struct gendisk *disk);
333 extern void disk_unblock_events(struct gendisk *disk);
334 extern void disk_flush_events(struct gendisk *disk, unsigned int mask);
335 extern void set_capacity_revalidate_and_notify(struct gendisk *disk,
336 sector_t size, bool revalidate);
337 extern unsigned int disk_clear_events(struct gendisk *disk, unsigned int mask);
339 /* drivers/char/random.c */
340 extern void add_disk_randomness(struct gendisk *disk) __latent_entropy;
341 extern void rand_initialize_disk(struct gendisk *disk);
343 static inline sector_t get_start_sect(struct block_device *bdev)
345 return bdev->bd_part->start_sect;
347 static inline sector_t get_capacity(struct gendisk *disk)
349 return disk->part0.nr_sects;
351 static inline void set_capacity(struct gendisk *disk, sector_t size)
353 disk->part0.nr_sects = size;
356 extern dev_t blk_lookup_devt(const char *name, int partno);
358 int bdev_disk_changed(struct block_device *bdev, bool invalidate);
359 int blk_add_partitions(struct gendisk *disk, struct block_device *bdev);
360 int blk_drop_partitions(struct block_device *bdev);
361 extern void printk_all_partitions(void);
363 extern struct gendisk *__alloc_disk_node(int minors, int node_id);
364 extern struct kobject *get_disk_and_module(struct gendisk *disk);
365 extern void put_disk(struct gendisk *disk);
366 extern void put_disk_and_module(struct gendisk *disk);
367 extern void blk_register_region(dev_t devt, unsigned long range,
368 struct module *module,
369 struct kobject *(*probe)(dev_t, int *, void *),
370 int (*lock)(dev_t, void *),
372 extern void blk_unregister_region(dev_t devt, unsigned long range);
374 #define alloc_disk_node(minors, node_id) \
376 static struct lock_class_key __key; \
377 const char *__name; \
378 struct gendisk *__disk; \
380 __name = "(gendisk_completion)"#minors"("#node_id")"; \
382 __disk = __alloc_disk_node(minors, node_id); \
385 lockdep_init_map(&__disk->lockdep_map, __name, &__key, 0); \
390 #define alloc_disk(minors) alloc_disk_node(minors, NUMA_NO_NODE)
392 #else /* CONFIG_BLOCK */
394 static inline void printk_all_partitions(void) { }
396 static inline dev_t blk_lookup_devt(const char *name, int partno)
398 dev_t devt = MKDEV(0, 0);
401 #endif /* CONFIG_BLOCK */
403 #endif /* _LINUX_GENHD_H */