1#include <linux/fs.h>
 2#include <linux/init.h>
 3#include <linux/proc_fs.h>
 4#include <linux/seq_file.h>
 
 5
 6static int devinfo_show(struct seq_file *f, void *v)
 7{
 8	int i = *(loff_t *) v;
 9
10	if (i < CHRDEV_MAJOR_HASH_SIZE) {
11		if (i == 0)
12			seq_puts(f, "Character devices:\n");
13		chrdev_show(f, i);
14	}
15#ifdef CONFIG_BLOCK
16	else {
17		i -= CHRDEV_MAJOR_HASH_SIZE;
18		if (i == 0)
19			seq_puts(f, "\nBlock devices:\n");
20		blkdev_show(f, i);
21	}
22#endif
23	return 0;
24}
25
26static void *devinfo_start(struct seq_file *f, loff_t *pos)
27{
28	if (*pos < (BLKDEV_MAJOR_HASH_SIZE + CHRDEV_MAJOR_HASH_SIZE))
29		return pos;
30	return NULL;
31}
32
33static void *devinfo_next(struct seq_file *f, void *v, loff_t *pos)
34{
35	(*pos)++;
36	if (*pos >= (BLKDEV_MAJOR_HASH_SIZE + CHRDEV_MAJOR_HASH_SIZE))
37		return NULL;
38	return pos;
39}
40
41static void devinfo_stop(struct seq_file *f, void *v)
42{
43	/* Nothing to do */
44}
45
46static const struct seq_operations devinfo_ops = {
47	.start = devinfo_start,
48	.next  = devinfo_next,
49	.stop  = devinfo_stop,
50	.show  = devinfo_show
51};
52
53static int devinfo_open(struct inode *inode, struct file *filp)
54{
55	return seq_open(filp, &devinfo_ops);
56}
57
58static const struct file_operations proc_devinfo_operations = {
59	.open		= devinfo_open,
60	.read		= seq_read,
61	.llseek		= seq_lseek,
62	.release	= seq_release,
63};
64
65static int __init proc_devices_init(void)
66{
67	proc_create("devices", 0, NULL, &proc_devinfo_operations);
68	return 0;
69}
70module_init(proc_devices_init);

 1// SPDX-License-Identifier: GPL-2.0
 2#include <linux/fs.h>
 3#include <linux/init.h>
 4#include <linux/proc_fs.h>
 5#include <linux/seq_file.h>
 6#include <linux/blkdev.h>
 7
 8static int devinfo_show(struct seq_file *f, void *v)
 9{
10	int i = *(loff_t *) v;
11
12	if (i < CHRDEV_MAJOR_MAX) {
13		if (i == 0)
14			seq_puts(f, "Character devices:\n");
15		chrdev_show(f, i);
16	}
17#ifdef CONFIG_BLOCK
18	else {
19		i -= CHRDEV_MAJOR_MAX;
20		if (i == 0)
21			seq_puts(f, "\nBlock devices:\n");
22		blkdev_show(f, i);
23	}
24#endif
25	return 0;
26}
27
28static void *devinfo_start(struct seq_file *f, loff_t *pos)
29{
30	if (*pos < (BLKDEV_MAJOR_MAX + CHRDEV_MAJOR_MAX))
31		return pos;
32	return NULL;
33}
34
35static void *devinfo_next(struct seq_file *f, void *v, loff_t *pos)
36{
37	(*pos)++;
38	if (*pos >= (BLKDEV_MAJOR_MAX + CHRDEV_MAJOR_MAX))
39		return NULL;
40	return pos;
41}
42
43static void devinfo_stop(struct seq_file *f, void *v)
44{
45	/* Nothing to do */
46}
47
48static const struct seq_operations devinfo_ops = {
49	.start = devinfo_start,
50	.next  = devinfo_next,
51	.stop  = devinfo_stop,
52	.show  = devinfo_show
53};
54
 
 
 
 
 
 
 
 
 
 
 
 
55static int __init proc_devices_init(void)
56{
57	proc_create_seq("devices", 0, NULL, &devinfo_ops);
58	return 0;
59}
60fs_initcall(proc_devices_init);