aboutsummaryrefslogtreecommitdiffstats
path: root/include/linux/genhd.h
blob: f364619092cca0dfeddfebc4bbdde97b37c34674 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_GENHD_H
#define _LINUX_GENHD_H

/*
 * 	genhd.h Copyright (C) 1992 Drew Eckhardt
 *	Generic hard disk header file by  
 * 		Drew Eckhardt
 *
 *		<drew@colorado.edu>
 */

#include <linux/types.h>
#include <linux/kdev_t.h>
#include <linux/rcupdate.h>
#include <linux/slab.h>
#include <linux/percpu-refcount.h>
#include <linux/uuid.h>
#include <linux/blk_types.h>
#include <asm/local.h>

extern const struct device_type disk_type;
extern struct device_type part_type;
extern struct class block_class;

#define DISK_MAX_PARTS			256
#define DISK_NAME_LEN			32

#include <linux/major.h>
#include <linux/device.h>
#include <linux/smp.h>
#include <linux/string.h>
#include <linux/fs.h>
#include <linux/workqueue.h>
#include <linux/xarray.h>

#define PARTITION_META_INFO_VOLNAMELTH	64
/*
 * Enough for the string representation of any kind of UUID plus NULL.
 * EFI UUID is 36 characters. MSDOS UUID is 11 characters.
 */
#define PARTITION_META_INFO_UUIDLTH	(UUID_STRING_LEN + 1)

struct partition_meta_info {
	char uuid[PARTITION_META_INFO_UUIDLTH];
	u8 volname[PARTITION_META_INFO_VOLNAMELTH];
};

/**
 * DOC: genhd capability flags
 *
 * ``GENHD_FL_REMOVABLE`` (0x0001): indicates that the block device
 * gives access to removable media.
 * When set, the device remains present even when media is not
 * inserted.
 * Must not be set for devices which are removed entirely when the
 * media is removed.
 *
 * ``GENHD_FL_CD`` (0x0008): the block device is a CD-ROM-style
 * device.
 * Affects responses to the ``CDROM_GET_CAPABILITY`` ioctl.
 *
 * ``GENHD_FL_UP`` (0x0010): indicates that the block device is "up",
 * with a similar meaning to network interfaces.
 *
 * ``GENHD_FL_SUPPRESS_PARTITION_INFO`` (0x0020): don't include
 * partition information in ``/proc/partitions`` or in the output of
 * printk_all_partitions().
 * Used for the null block device and some MMC devices.
 *
 * ``GENHD_FL_EXT_DEVT`` (0x0040): the driver supports extended
 * dynamic ``dev_t``, i.e. it wants extended device numbers
 * (``BLOCK_EXT_MAJOR``).
 * This affects the maximum number of partitions.
 *
 * ``GENHD_FL_NATIVE_CAPACITY`` (0x0080): based on information in the
 * partition table, the device's capacity has been extended to its
 * native capacity; i.e. the device has hidden capacity used by one
 * of the partitions (this is a flag used so that native capacity is
 * only ever unlocked once).
 *
 * ``GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE`` (0x0100): event polling is
 * blocked whenever a writer holds an exclusive lock.
 *
 * ``GENHD_FL_NO_PART_SCAN`` (0x0200): partition scanning is disabled.
 * Used for loop devices in their default settings and some MMC
 * devices.
 *
 * ``GENHD_FL_HIDDEN`` (0x0400): the block device is hidden; it
 * doesn't produce events, doesn't appear in sysfs, and doesn't have
 * an associated ``bdev``.
 * Implies ``GENHD_FL_SUPPRESS_PARTITION_INFO`` and
 * ``GENHD_FL_NO_PART_SCAN``.
 * Used for multipath devices.
 */
#define GENHD_FL_REMOVABLE			0x0001
/* 2 is unused (used to be GENHD_FL_DRIVERFS) */
/* 4 is unused (used to be GENHD_FL_MEDIA_CHANGE_NOTIFY) */
#define GENHD_FL_CD				0x0008
#define GENHD_FL_UP				0x0010
#define GENHD_FL_SUPPRESS_PARTITION_INFO	0x0020
#define GENHD_FL_EXT_DEVT			0x0040
#define GENHD_FL_NATIVE_CAPACITY		0x0080
#define GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE	0x0100
#define GENHD_FL_NO_PART_SCAN			0x0200
#define GENHD_FL_HIDDEN				0x0400

enum {
	DISK_EVENT_MEDIA_CHANGE			= 1 << 0, /* media changed */
	DISK_EVENT_EJECT_REQUEST		= 1 << 1, /* eject requested */
};

enum {
	/* Poll even if events_poll_msecs is unset */
	DISK_EVENT_FLAG_POLL			= 1 << 0,
	/* Forward events to udev */
	DISK_EVENT_FLAG_UEVENT			= 1 << 1,
};

struct disk_events;
struct badblocks;

struct blk_integrity {
	const struct blk_integrity_profile	*profile;
	unsigned char				flags;
	unsigned char				tuple_size;
	unsigned char				interval_exp;
	unsigned char				tag_size;
};

struct gendisk {
	/* major, first_minor and minors are input parameters only,
	 * don't use directly.  Use disk_devt() and disk_max_parts().
	 */
	int major;			/* major number of driver */
	int first_minor;
	int minors;                     /* maximum number of minors, =1 for
                                         * disks that can't be partitioned. */

	char disk_name[DISK_NAME_LEN];	/* name of major driver */

	unsigned short events;		/* supported events */
	unsigned short event_flags;	/* flags related to event processing */

	struct xarray part_tbl;
	struct block_device *part0;

	const struct block_device_operations *fops;
	struct request_queue *queue;
	void *private_data;

	int flags;
	unsigned long state;
#define GD_NEED_PART_SCAN		0
#define GD_READ_ONLY			1
	struct kobject *slave_dir;

	struct timer_rand_state *random;
	atomic_t sync_io;		/* RAID */
	struct disk_events *ev;
#ifdef  CONFIG_BLK_DEV_INTEGRITY
	struct kobject integrity_kobj;
#endif	/* CONFIG_BLK_DEV_INTEGRITY */
#if IS_ENABLED(CONFIG_CDROM)
	struct cdrom_device_info *cdi;
#endif
	int node_id;
	struct badblocks *bb;
	struct lockdep_map lockdep_map;
};

/*
 * The gendisk is refcounted by the part0 block_device, and the bd_device
 * therein is also used for device model presentation in sysfs.
 */
#define dev_to_disk(device) \
	(dev_to_bdev(device)->bd_disk)
#define disk_to_dev(disk) \
	(&((disk)->part0->bd_device))

#if IS_REACHABLE(CONFIG_CDROM)
#define disk_to_cdi(disk)	((disk)->cdi)
#else
#define disk_to_cdi(disk)	NULL
#endif

static inline int disk_max_parts(struct gendisk *disk)
{
	if (disk->flags & GENHD_FL_EXT_DEVT)
		return DISK_MAX_PARTS;
	return disk->minors;
}

static inline bool disk_part_scan_enabled(struct gendisk *disk)
{
	return disk_max_parts(disk) > 1 &&
		!(disk->flags & GENHD_FL_NO_PART_SCAN);
}

static inline dev_t disk_devt(struct gendisk *disk)
{
	return MKDEV(disk->major, disk->first_minor);
}

void disk_uevent(struct gendisk *disk, enum kobject_action action);

/*
 * Smarter partition iterator without context limits.
 */
#define DISK_PITER_INCL_EMPTY	(1 << 1) /* include 0-sized parts */
#define DISK_PITER_INCL_PART0	(1 << 2) /* include partition 0 */
#define DISK_PITER_INCL_EMPTY_PART0 (1 << 3) /* include empty partition 0 */

struct disk_part_iter {
	struct gendisk		*disk;
	struct block_device	*part;
	unsigned long		idx;
	unsigned int		flags;
};

extern void disk_part_iter_init(struct disk_part_iter *piter,
				 struct gendisk *disk, unsigned int flags);
struct block_device *disk_part_iter_next(struct disk_part_iter *piter);
extern void disk_part_iter_exit(struct disk_part_iter *piter);

/* block/genhd.c */
extern void device_add_disk(struct device *parent, struct gendisk *disk,
			    const struct attribute_group **groups);
static inline void add_disk(struct gendisk *disk)
{
	device_add_disk(NULL, disk, NULL);
}
extern void device_add_disk_no_queue_reg(struct device *parent, struct gendisk *disk);
static inline void add_disk_no_queue_reg(struct gendisk *disk)
{
	device_add_disk_no_queue_reg(NULL, disk);
}

extern void del_gendisk(struct gendisk *gp);
extern struct block_device *bdget_disk(struct gendisk *disk, int partno);

void set_disk_ro(struct gendisk *disk, bool read_only);

static inline int get_disk_ro(struct gendisk *disk)
{
	return disk->part0->bd_read_only ||
		test_bit(GD_READ_ONLY, &disk->state);
}

extern void disk_block_events(struct gendisk *disk);
extern void disk_unblock_events(struct gendisk *disk);
extern void disk_flush_events(struct gendisk *disk, unsigned int mask);
bool set_capacity_and_notify(struct gendisk *disk, sector_t size);

/* drivers/char/random.c */
extern void add_disk_randomness(struct gendisk *disk) __latent_entropy;
extern void rand_initialize_disk(struct gendisk *disk);

static inline sector_t get_start_sect(struct block_device *bdev)
{
	return bdev->bd_start_sect;
}

static inline sector_t bdev_nr_sectors(struct block_device *bdev)
{
	return i_size_read(bdev->bd_inode) >> 9;
}

static inline sector_t get_capacity(struct gendisk *disk)
{
	return bdev_nr_sectors(disk->part0);
}

int bdev_disk_changed(struct block_device *bdev, bool invalidate);
int blk_add_partitions(struct gendisk *disk, struct block_device *bdev);
int blk_drop_partitions(struct block_device *bdev);

extern struct gendisk *__alloc_disk_node(int minors, int node_id);
extern void put_disk(struct gendisk *disk);

#define alloc_disk_node(minors, node_id)				\
({									\
	static struct lock_class_key __key;				\
	const char *__name;						\
	struct gendisk *__disk;						\
									\
	__name = "(gendisk_completion)"#minors"("#node_id")";		\
									\
	__disk = __alloc_disk_node(minors, node_id);			\
									\
	if (__disk)							\
		lockdep_init_map(&__disk->lockdep_map, __name, &__key, 0); \
									\
	__disk;								\
})

#define alloc_disk(minors) alloc_disk_node(minors, NUMA_NO_NODE)

int __register_blkdev(unsigned int major, const char *name,
		void (*probe)(dev_t devt));
#define register_blkdev(major, name) \
	__register_blkdev(major, name, NULL)
void unregister_blkdev(unsigned int major, const char *name);

bool bdev_check_media_change(struct block_device *bdev);
int __invalidate_device(struct block_device *bdev, bool kill_dirty);
void set_capacity(struct gendisk *disk, sector_t size);

/* for drivers/char/raw.c: */
int blkdev_ioctl(struct block_device *, fmode_t, unsigned, unsigned long);
long compat_blkdev_ioctl(struct file *, unsigned, unsigned long);

#ifdef CONFIG_SYSFS
int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk);
void bd_unlink_disk_holder(struct block_device *bdev, struct gendisk *disk);
#else
static inline int bd_link_disk_holder(struct block_device *bdev,
				      struct gendisk *disk)
{
	return 0;
}
static inline void bd_unlink_disk_holder(struct block_device *bdev,
					 struct gendisk *disk)
{
}
#endif /* CONFIG_SYSFS */

extern struct rw_semaphore bdev_lookup_sem;

dev_t blk_lookup_devt(const char *name, int partno);
void blk_request_module(dev_t devt);
#ifdef CONFIG_BLOCK
void printk_all_partitions(void);
#else /* CONFIG_BLOCK */
static inline void printk_all_partitions(void)
{
}
#endif /* CONFIG_BLOCK */

#endif /* _LINUX_GENHD_H */

Privacy Policy