1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_GENHD_H
3 #define _LINUX_GENHD_H
4
5 /*
6 * genhd.h Copyright (C) 1992 Drew Eckhardt
7 * Generic hard disk header file by
8 * Drew Eckhardt
9 *
10 * <drew@colorado.edu>
11 */
12
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>
21
22 extern const struct device_type disk_type;
23 extern struct device_type part_type;
24 extern struct class block_class;
25
26 #define DISK_MAX_PARTS 256
27 #define DISK_NAME_LEN 32
28
29 #include <linux/major.h>
30 #include <linux/device.h>
31 #include <linux/smp.h>
32 #include <linux/string.h>
33 #include <linux/fs.h>
34 #include <linux/workqueue.h>
35 #include <linux/xarray.h>
36
37 #define PARTITION_META_INFO_VOLNAMELTH 64
38 /*
39 * Enough for the string representation of any kind of UUID plus NULL.
40 * EFI UUID is 36 characters. MSDOS UUID is 11 characters.
41 */
42 #define PARTITION_META_INFO_UUIDLTH (UUID_STRING_LEN + 1)
43
44 struct partition_meta_info {
45 char uuid[PARTITION_META_INFO_UUIDLTH];
46 u8 volname[PARTITION_META_INFO_VOLNAMELTH];
47 };
48
49 /**
50 * DOC: genhd capability flags
51 *
52 * ``GENHD_FL_REMOVABLE`` (0x0001): indicates that the block device
53 * gives access to removable media.
54 * When set, the device remains present even when media is not
55 * inserted.
56 * Must not be set for devices which are removed entirely when the
57 * media is removed.
58 *
59 * ``GENHD_FL_CD`` (0x0008): the block device is a CD-ROM-style
60 * device.
61 * Affects responses to the ``CDROM_GET_CAPABILITY`` ioctl.
62 *
63 * ``GENHD_FL_SUPPRESS_PARTITION_INFO`` (0x0020): don't include
64 * partition information in ``/proc/partitions`` or in the output of
65 * printk_all_partitions().
66 * Used for the null block device and some MMC devices.
67 *
68 * ``GENHD_FL_EXT_DEVT`` (0x0040): the driver supports extended
69 * dynamic ``dev_t``, i.e. it wants extended device numbers
70 * (``BLOCK_EXT_MAJOR``).
71 * This affects the maximum number of partitions.
72 *
73 * ``GENHD_FL_NATIVE_CAPACITY`` (0x0080): based on information in the
74 * partition table, the device's capacity has been extended to its
75 * native capacity; i.e. the device has hidden capacity used by one
76 * of the partitions (this is a flag used so that native capacity is
77 * only ever unlocked once).
78 *
79 * ``GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE`` (0x0100): event polling is
80 * blocked whenever a writer holds an exclusive lock.
81 *
82 * ``GENHD_FL_NO_PART_SCAN`` (0x0200): partition scanning is disabled.
83 * Used for loop devices in their default settings and some MMC
84 * devices.
85 *
86 * ``GENHD_FL_HIDDEN`` (0x0400): the block device is hidden; it
87 * doesn't produce events, doesn't appear in sysfs, and doesn't have
88 * an associated ``bdev``.
89 * Implies ``GENHD_FL_SUPPRESS_PARTITION_INFO`` and
90 * ``GENHD_FL_NO_PART_SCAN``.
91 * Used for multipath devices.
92 */
93 #define GENHD_FL_REMOVABLE 0x0001
94 /* 2 is unused (used to be GENHD_FL_DRIVERFS) */
95 /* 4 is unused (used to be GENHD_FL_MEDIA_CHANGE_NOTIFY) */
96 #define GENHD_FL_CD 0x0008
97 #define GENHD_FL_SUPPRESS_PARTITION_INFO 0x0020
98 #define GENHD_FL_EXT_DEVT 0x0040
99 #define GENHD_FL_NATIVE_CAPACITY 0x0080
100 #define GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE 0x0100
101 #define GENHD_FL_NO_PART_SCAN 0x0200
102 #define GENHD_FL_HIDDEN 0x0400
103
104 enum {
105 DISK_EVENT_MEDIA_CHANGE = 1 << 0, /* media changed */
106 DISK_EVENT_EJECT_REQUEST = 1 << 1, /* eject requested */
107 };
108
109 enum {
110 /* Poll even if events_poll_msecs is unset */
111 DISK_EVENT_FLAG_POLL = 1 << 0,
112 /* Forward events to udev */
113 DISK_EVENT_FLAG_UEVENT = 1 << 1,
114 };
115
116 struct disk_events;
117 struct badblocks;
118
119 struct blk_integrity {
120 const struct blk_integrity_profile *profile;
121 unsigned char flags;
122 unsigned char tuple_size;
123 unsigned char interval_exp;
124 unsigned char tag_size;
125 };
126
127 struct gendisk {
128 /* major, first_minor and minors are input parameters only,
129 * don't use directly. Use disk_devt() and disk_max_parts().
130 */
131 int major; /* major number of driver */
132 int first_minor;
133 int minors; /* maximum number of minors, =1 for
134 * disks that can't be partitioned. */
135
136 char disk_name[DISK_NAME_LEN]; /* name of major driver */
137
138 unsigned short events; /* supported events */
139 unsigned short event_flags; /* flags related to event processing */
140
141 struct xarray part_tbl;
142 struct block_device *part0;
143
144 const struct block_device_operations *fops;
145 struct request_queue *queue;
146 void *private_data;
147
148 int flags;
149 unsigned long state;
150 #define GD_NEED_PART_SCAN 0
151 #define GD_READ_ONLY 1
152 #define GD_DEAD 2
153
154 struct mutex open_mutex; /* open/close mutex */
155 unsigned open_partitions; /* number of open partitions */
156
157 struct backing_dev_info *bdi;
158 struct kobject *slave_dir;
159 #ifdef CONFIG_BLOCK_HOLDER_DEPRECATED
160 struct list_head slave_bdevs;
161 #endif
162 struct timer_rand_state *random;
163 atomic_t sync_io; /* RAID */
164 struct disk_events *ev;
165 #ifdef CONFIG_BLK_DEV_INTEGRITY
166 struct kobject integrity_kobj;
167 #endif /* CONFIG_BLK_DEV_INTEGRITY */
168 #if IS_ENABLED(CONFIG_CDROM)
169 struct cdrom_device_info *cdi;
170 #endif
171 int node_id;
172 struct badblocks *bb;
173 struct lockdep_map lockdep_map;
174 u64 diskseq;
175 };
176
disk_live(struct gendisk * disk)177 static inline bool disk_live(struct gendisk *disk)
178 {
179 return !inode_unhashed(disk->part0->bd_inode);
180 }
181
182 /*
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.
185 */
186 #define dev_to_disk(device) \
187 (dev_to_bdev(device)->bd_disk)
188 #define disk_to_dev(disk) \
189 (&((disk)->part0->bd_device))
190
191 #if IS_REACHABLE(CONFIG_CDROM)
192 #define disk_to_cdi(disk) ((disk)->cdi)
193 #else
194 #define disk_to_cdi(disk) NULL
195 #endif
196
disk_max_parts(struct gendisk * disk)197 static inline int disk_max_parts(struct gendisk *disk)
198 {
199 if (disk->flags & GENHD_FL_EXT_DEVT)
200 return DISK_MAX_PARTS;
201 return disk->minors;
202 }
203
disk_part_scan_enabled(struct gendisk * disk)204 static inline bool disk_part_scan_enabled(struct gendisk *disk)
205 {
206 return disk_max_parts(disk) > 1 &&
207 !(disk->flags & GENHD_FL_NO_PART_SCAN);
208 }
209
disk_devt(struct gendisk * disk)210 static inline dev_t disk_devt(struct gendisk *disk)
211 {
212 return MKDEV(disk->major, disk->first_minor);
213 }
214
215 void disk_uevent(struct gendisk *disk, enum kobject_action action);
216
217 /* block/genhd.c */
218 int device_add_disk(struct device *parent, struct gendisk *disk,
219 const struct attribute_group **groups);
add_disk(struct gendisk * disk)220 static inline int add_disk(struct gendisk *disk)
221 {
222 return device_add_disk(NULL, disk, NULL);
223 }
224 extern void del_gendisk(struct gendisk *gp);
225
226 void set_disk_ro(struct gendisk *disk, bool read_only);
227
get_disk_ro(struct gendisk * disk)228 static inline int get_disk_ro(struct gendisk *disk)
229 {
230 return disk->part0->bd_read_only ||
231 test_bit(GD_READ_ONLY, &disk->state);
232 }
233
234 extern void disk_block_events(struct gendisk *disk);
235 extern void disk_unblock_events(struct gendisk *disk);
236 extern void disk_flush_events(struct gendisk *disk, unsigned int mask);
237 bool set_capacity_and_notify(struct gendisk *disk, sector_t size);
238 bool disk_force_media_change(struct gendisk *disk, unsigned int events);
239
240 /* drivers/char/random.c */
241 extern void add_disk_randomness(struct gendisk *disk) __latent_entropy;
242 extern void rand_initialize_disk(struct gendisk *disk);
243
get_start_sect(struct block_device * bdev)244 static inline sector_t get_start_sect(struct block_device *bdev)
245 {
246 return bdev->bd_start_sect;
247 }
248
bdev_nr_sectors(struct block_device * bdev)249 static inline sector_t bdev_nr_sectors(struct block_device *bdev)
250 {
251 return i_size_read(bdev->bd_inode) >> 9;
252 }
253
get_capacity(struct gendisk * disk)254 static inline sector_t get_capacity(struct gendisk *disk)
255 {
256 return bdev_nr_sectors(disk->part0);
257 }
258
259 int bdev_disk_changed(struct gendisk *disk, bool invalidate);
260 void blk_drop_partitions(struct gendisk *disk);
261
262 struct gendisk *__alloc_disk_node(struct request_queue *q, int node_id,
263 struct lock_class_key *lkclass);
264 extern void put_disk(struct gendisk *disk);
265 struct gendisk *__blk_alloc_disk(int node, struct lock_class_key *lkclass);
266
267 /**
268 * blk_alloc_disk - allocate a gendisk structure
269 * @node_id: numa node to allocate on
270 *
271 * Allocate and pre-initialize a gendisk structure for use with BIO based
272 * drivers.
273 *
274 * Context: can sleep
275 */
276 #define blk_alloc_disk(node_id) \
277 ({ \
278 static struct lock_class_key __key; \
279 \
280 __blk_alloc_disk(node_id, &__key); \
281 })
282 void blk_cleanup_disk(struct gendisk *disk);
283
284 int __register_blkdev(unsigned int major, const char *name,
285 void (*probe)(dev_t devt));
286 #define register_blkdev(major, name) \
287 __register_blkdev(major, name, NULL)
288 void unregister_blkdev(unsigned int major, const char *name);
289
290 bool bdev_check_media_change(struct block_device *bdev);
291 int __invalidate_device(struct block_device *bdev, bool kill_dirty);
292 void set_capacity(struct gendisk *disk, sector_t size);
293
294 /* for drivers/char/raw.c: */
295 int blkdev_ioctl(struct block_device *, fmode_t, unsigned, unsigned long);
296 long compat_blkdev_ioctl(struct file *, unsigned, unsigned long);
297
298 #ifdef CONFIG_BLOCK_HOLDER_DEPRECATED
299 int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk);
300 void bd_unlink_disk_holder(struct block_device *bdev, struct gendisk *disk);
301 int bd_register_pending_holders(struct gendisk *disk);
302 #else
bd_link_disk_holder(struct block_device * bdev,struct gendisk * disk)303 static inline int bd_link_disk_holder(struct block_device *bdev,
304 struct gendisk *disk)
305 {
306 return 0;
307 }
bd_unlink_disk_holder(struct block_device * bdev,struct gendisk * disk)308 static inline void bd_unlink_disk_holder(struct block_device *bdev,
309 struct gendisk *disk)
310 {
311 }
bd_register_pending_holders(struct gendisk * disk)312 static inline int bd_register_pending_holders(struct gendisk *disk)
313 {
314 return 0;
315 }
316 #endif /* CONFIG_BLOCK_HOLDER_DEPRECATED */
317
318 dev_t part_devt(struct gendisk *disk, u8 partno);
319 void inc_diskseq(struct gendisk *disk);
320 dev_t blk_lookup_devt(const char *name, int partno);
321 void blk_request_module(dev_t devt);
322 #ifdef CONFIG_BLOCK
323 void printk_all_partitions(void);
324 #else /* CONFIG_BLOCK */
printk_all_partitions(void)325 static inline void printk_all_partitions(void)
326 {
327 }
328 #endif /* CONFIG_BLOCK */
329
330 #endif /* _LINUX_GENHD_H */
331
