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
|
// SPDX-License-Identifier: GPL-2.0
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
static int devinfo_show(struct seq_file *f, void *v)
{
int i = *(loff_t *) v;
if (i < CHRDEV_MAJOR_MAX) {
if (i == 0)
seq_puts(f, "Character devices:\n");
chrdev_show(f, i);
}
#ifdef CONFIG_BLOCK
else {
i -= CHRDEV_MAJOR_MAX;
if (i == 0)
seq_puts(f, "\nBlock devices:\n");
blkdev_show(f, i);
}
#endif
return 0;
}
static void *devinfo_start(struct seq_file *f, loff_t *pos)
{
if (*pos < (BLKDEV_MAJOR_MAX + CHRDEV_MAJOR_MAX))
return pos;
return NULL;
}
static void *devinfo_next(struct seq_file *f, void *v, loff_t *pos)
{
(*pos)++;
if (*pos >= (BLKDEV_MAJOR_MAX + CHRDEV_MAJOR_MAX))
return NULL;
return pos;
}
static void devinfo_stop(struct seq_file *f, void *v)
{
/* Nothing to do */
}
static const struct seq_operations devinfo_ops = {
.start = devinfo_start,
.next = devinfo_next,
.stop = devinfo_stop,
.show = devinfo_show
};
static int devinfo_open(struct inode *inode, struct file *filp)
{
return seq_open(filp, &devinfo_ops);
}
static const struct file_operations proc_devinfo_operations = {
.open = devinfo_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release,
};
static int __init proc_devices_init(void)
{
proc_create("devices", 0, NULL, &proc_devinfo_operations);
return 0;
}
fs_initcall(proc_devices_init);
|
