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_UP`` (0x0010): indicates that the block device is "up",
64 * with a similar meaning to network interfaces.
65 *
66 * ``GENHD_FL_SUPPRESS_PARTITION_INFO`` (0x0020): don't include
67 * partition information in ``/proc/partitions`` or in the output of
68 * printk_all_partitions().
69 * Used for the null block device and some MMC devices.
70 *
71 * ``GENHD_FL_EXT_DEVT`` (0x0040): the driver supports extended
72 * dynamic ``dev_t``, i.e. it wants extended device numbers
73 * (``BLOCK_EXT_MAJOR``).
74 * This affects the maximum number of partitions.
75 *
76 * ``GENHD_FL_NATIVE_CAPACITY`` (0x0080): based on information in the
77 * partition table, the device's capacity has been extended to its
78 * native capacity; i.e. the device has hidden capacity used by one
79 * of the partitions (this is a flag used so that native capacity is
80 * only ever unlocked once).
81 *
82 * ``GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE`` (0x0100): event polling is
83 * blocked whenever a writer holds an exclusive lock.
84 *
85 * ``GENHD_FL_NO_PART_SCAN`` (0x0200): partition scanning is disabled.
86 * Used for loop devices in their default settings and some MMC
87 * devices.
88 *
89 * ``GENHD_FL_HIDDEN`` (0x0400): the block device is hidden; it
90 * doesn't produce events, doesn't appear in sysfs, and doesn't have
91 * an associated ``bdev``.
92 * Implies ``GENHD_FL_SUPPRESS_PARTITION_INFO`` and
93 * ``GENHD_FL_NO_PART_SCAN``.
94 * Used for multipath devices.
95 */
96 #define GENHD_FL_REMOVABLE 0x0001
97 /* 2 is unused (used to be GENHD_FL_DRIVERFS) */
98 /* 4 is unused (used to be GENHD_FL_MEDIA_CHANGE_NOTIFY) */
99 #define GENHD_FL_CD 0x0008
100 #define GENHD_FL_UP 0x0010
101 #define GENHD_FL_SUPPRESS_PARTITION_INFO 0x0020
102 #define GENHD_FL_EXT_DEVT 0x0040
103 #define GENHD_FL_NATIVE_CAPACITY 0x0080
104 #define GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE 0x0100
105 #define GENHD_FL_NO_PART_SCAN 0x0200
106 #define GENHD_FL_HIDDEN 0x0400
107
108 enum {
109 DISK_EVENT_MEDIA_CHANGE = 1 << 0, /* media changed */
110 DISK_EVENT_EJECT_REQUEST = 1 << 1, /* eject requested */
111 };
112
113 enum {
114 /* Poll even if events_poll_msecs is unset */
115 DISK_EVENT_FLAG_POLL = 1 << 0,
116 /* Forward events to udev */
117 DISK_EVENT_FLAG_UEVENT = 1 << 1,
118 };
119
120 struct disk_events;
121 struct badblocks;
122
123 struct blk_integrity {
124 const struct blk_integrity_profile *profile;
125 unsigned char flags;
126 unsigned char tuple_size;
127 unsigned char interval_exp;
128 unsigned char tag_size;
129 };
130
131 struct gendisk {
132 /* major, first_minor and minors are input parameters only,
133 * don't use directly. Use disk_devt() and disk_max_parts().
134 */
135 int major; /* major number of driver */
136 int first_minor;
137 int minors; /* maximum number of minors, =1 for
138 * disks that can't be partitioned. */
139
140 char disk_name[DISK_NAME_LEN]; /* name of major driver */
141
142 unsigned short events; /* supported events */
143 unsigned short event_flags; /* flags related to event processing */
144
145 struct xarray part_tbl;
146 struct block_device *part0;
147
148 const struct block_device_operations *fops;
149 struct request_queue *queue;
150 void *private_data;
151
152 int flags;
153 unsigned long state;
154 #define GD_NEED_PART_SCAN 0
155 #define GD_READ_ONLY 1
156 struct kobject *slave_dir;
157
158 struct timer_rand_state *random;
159 atomic_t sync_io; /* RAID */
160 struct disk_events *ev;
161 #ifdef CONFIG_BLK_DEV_INTEGRITY
162 struct kobject integrity_kobj;
163 #endif /* CONFIG_BLK_DEV_INTEGRITY */
164 #if IS_ENABLED(CONFIG_CDROM)
165 struct cdrom_device_info *cdi;
166 #endif
167 int node_id;
168 struct badblocks *bb;
169 struct lockdep_map lockdep_map;
170 };
171
172 /*
173 * The gendisk is refcounted by the part0 block_device, and the bd_device
174 * therein is also used for device model presentation in sysfs.
175 */
176 #define dev_to_disk(device) \
177 (dev_to_bdev(device)->bd_disk)
178 #define disk_to_dev(disk) \
179 (&((disk)->part0->bd_device))
180
181 #if IS_REACHABLE(CONFIG_CDROM)
182 #define disk_to_cdi(disk) ((disk)->cdi)
183 #else
184 #define disk_to_cdi(disk) NULL
185 #endif
186
disk_max_parts(struct gendisk * disk)187 static inline int disk_max_parts(struct gendisk *disk)
188 {
189 if (disk->flags & GENHD_FL_EXT_DEVT)
190 return DISK_MAX_PARTS;
191 return disk->minors;
192 }
193
disk_part_scan_enabled(struct gendisk * disk)194 static inline bool disk_part_scan_enabled(struct gendisk *disk)
195 {
196 return disk_max_parts(disk) > 1 &&
197 !(disk->flags & GENHD_FL_NO_PART_SCAN);
198 }
199
disk_devt(struct gendisk * disk)200 static inline dev_t disk_devt(struct gendisk *disk)
201 {
202 return MKDEV(disk->major, disk->first_minor);
203 }
204
205 void disk_uevent(struct gendisk *disk, enum kobject_action action);
206
207 /* block/genhd.c */
208 extern void device_add_disk(struct device *parent, struct gendisk *disk,
209 const struct attribute_group **groups);
add_disk(struct gendisk * disk)210 static inline void add_disk(struct gendisk *disk)
211 {
212 device_add_disk(NULL, disk, NULL);
213 }
214 extern void device_add_disk_no_queue_reg(struct device *parent, struct gendisk *disk);
add_disk_no_queue_reg(struct gendisk * disk)215 static inline void add_disk_no_queue_reg(struct gendisk *disk)
216 {
217 device_add_disk_no_queue_reg(NULL, disk);
218 }
219
220 extern void del_gendisk(struct gendisk *gp);
221 extern struct block_device *bdget_disk(struct gendisk *disk, int partno);
222
223 void set_disk_ro(struct gendisk *disk, bool read_only);
224
get_disk_ro(struct gendisk * disk)225 static inline int get_disk_ro(struct gendisk *disk)
226 {
227 return disk->part0->bd_read_only ||
228 test_bit(GD_READ_ONLY, &disk->state);
229 }
230
231 extern void disk_block_events(struct gendisk *disk);
232 extern void disk_unblock_events(struct gendisk *disk);
233 extern void disk_flush_events(struct gendisk *disk, unsigned int mask);
234 bool set_capacity_and_notify(struct gendisk *disk, sector_t size);
235
236 /* drivers/char/random.c */
237 extern void add_disk_randomness(struct gendisk *disk) __latent_entropy;
238 extern void rand_initialize_disk(struct gendisk *disk);
239
get_start_sect(struct block_device * bdev)240 static inline sector_t get_start_sect(struct block_device *bdev)
241 {
242 return bdev->bd_start_sect;
243 }
244
bdev_nr_sectors(struct block_device * bdev)245 static inline sector_t bdev_nr_sectors(struct block_device *bdev)
246 {
247 return i_size_read(bdev->bd_inode) >> 9;
248 }
249
get_capacity(struct gendisk * disk)250 static inline sector_t get_capacity(struct gendisk *disk)
251 {
252 return bdev_nr_sectors(disk->part0);
253 }
254
255 int bdev_disk_changed(struct block_device *bdev, bool invalidate);
256 int blk_add_partitions(struct gendisk *disk, struct block_device *bdev);
257 void blk_drop_partitions(struct gendisk *disk);
258
259 extern struct gendisk *__alloc_disk_node(int minors, int node_id);
260 extern void put_disk(struct gendisk *disk);
261
262 #define alloc_disk_node(minors, node_id) \
263 ({ \
264 static struct lock_class_key __key; \
265 const char *__name; \
266 struct gendisk *__disk; \
267 \
268 __name = "(gendisk_completion)"#minors"("#node_id")"; \
269 \
270 __disk = __alloc_disk_node(minors, node_id); \
271 \
272 if (__disk) \
273 lockdep_init_map(&__disk->lockdep_map, __name, &__key, 0); \
274 \
275 __disk; \
276 })
277
278 #define alloc_disk(minors) alloc_disk_node(minors, NUMA_NO_NODE)
279
280 int __register_blkdev(unsigned int major, const char *name,
281 void (*probe)(dev_t devt));
282 #define register_blkdev(major, name) \
283 __register_blkdev(major, name, NULL)
284 void unregister_blkdev(unsigned int major, const char *name);
285
286 bool bdev_check_media_change(struct block_device *bdev);
287 int __invalidate_device(struct block_device *bdev, bool kill_dirty);
288 void set_capacity(struct gendisk *disk, sector_t size);
289
290 /* for drivers/char/raw.c: */
291 int blkdev_ioctl(struct block_device *, fmode_t, unsigned, unsigned long);
292 long compat_blkdev_ioctl(struct file *, unsigned, unsigned long);
293
294 #ifdef CONFIG_SYSFS
295 int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk);
296 void bd_unlink_disk_holder(struct block_device *bdev, struct gendisk *disk);
297 #else
bd_link_disk_holder(struct block_device * bdev,struct gendisk * disk)298 static inline int bd_link_disk_holder(struct block_device *bdev,
299 struct gendisk *disk)
300 {
301 return 0;
302 }
bd_unlink_disk_holder(struct block_device * bdev,struct gendisk * disk)303 static inline void bd_unlink_disk_holder(struct block_device *bdev,
304 struct gendisk *disk)
305 {
306 }
307 #endif /* CONFIG_SYSFS */
308
309 extern struct rw_semaphore bdev_lookup_sem;
310
311 dev_t blk_lookup_devt(const char *name, int partno);
312 void blk_request_module(dev_t devt);
313 #ifdef CONFIG_BLOCK
314 void printk_all_partitions(void);
315 #else /* CONFIG_BLOCK */
printk_all_partitions(void)316 static inline void printk_all_partitions(void)
317 {
318 }
319 #endif /* CONFIG_BLOCK */
320
321 #endif /* _LINUX_GENHD_H */
322