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
|
/*
* Copyright (C) 2010-2015 Junjiro R. Okajima
*/
/*
* procfs interfaces
*/
#include <linux/proc_fs.h>
#include "aufs.h"
static int au_procfs_plm_release(struct inode *inode, struct file *file)
{
struct au_sbinfo *sbinfo;
sbinfo = file->private_data;
if (sbinfo) {
au_plink_maint_leave(sbinfo);
kobject_put(&sbinfo->si_kobj);
}
return 0;
}
static void au_procfs_plm_write_clean(struct file *file)
{
struct au_sbinfo *sbinfo;
sbinfo = file->private_data;
if (sbinfo)
au_plink_clean(sbinfo->si_sb, /*verbose*/0);
}
static int au_procfs_plm_write_si(struct file *file, unsigned long id)
{
int err;
struct super_block *sb;
struct au_sbinfo *sbinfo;
err = -EBUSY;
if (unlikely(file->private_data))
goto out;
sb = NULL;
/* don't use au_sbilist_lock() here */
spin_lock(&au_sbilist.spin);
list_for_each_entry(sbinfo, &au_sbilist.head, si_list)
if (id == sysaufs_si_id(sbinfo)) {
kobject_get(&sbinfo->si_kobj);
sb = sbinfo->si_sb;
break;
}
spin_unlock(&au_sbilist.spin);
err = -EINVAL;
if (unlikely(!sb))
goto out;
err = au_plink_maint_enter(sb);
if (!err)
/* keep kobject_get() */
file->private_data = sbinfo;
else
kobject_put(&sbinfo->si_kobj);
out:
return err;
}
/*
* Accept a valid "si=xxxx" only.
* Once it is accepted successfully, accept "clean" too.
*/
static ssize_t au_procfs_plm_write(struct file *file, const char __user *ubuf,
size_t count, loff_t *ppos)
{
ssize_t err;
unsigned long id;
/* last newline is allowed */
char buf[3 + sizeof(unsigned long) * 2 + 1];
err = -EACCES;
if (unlikely(!capable(CAP_SYS_ADMIN)))
goto out;
err = -EINVAL;
if (unlikely(count > sizeof(buf)))
goto out;
err = copy_from_user(buf, ubuf, count);
if (unlikely(err)) {
err = -EFAULT;
goto out;
}
buf[count] = 0;
err = -EINVAL;
if (!strcmp("clean", buf)) {
au_procfs_plm_write_clean(file);
goto out_success;
} else if (unlikely(strncmp("si=", buf, 3)))
goto out;
err = kstrtoul(buf + 3, 16, &id);
if (unlikely(err))
goto out;
err = au_procfs_plm_write_si(file, id);
if (unlikely(err))
goto out;
out_success:
err = count; /* success */
out:
return err;
}
static const struct file_operations au_procfs_plm_fop = {
.write = au_procfs_plm_write,
.release = au_procfs_plm_release,
.owner = THIS_MODULE
};
/* ---------------------------------------------------------------------- */
static struct proc_dir_entry *au_procfs_dir;
void au_procfs_fin(void)
{
remove_proc_entry(AUFS_PLINK_MAINT_NAME, au_procfs_dir);
remove_proc_entry(AUFS_PLINK_MAINT_DIR, NULL);
}
int __init au_procfs_init(void)
{
int err;
struct proc_dir_entry *entry;
err = -ENOMEM;
au_procfs_dir = proc_mkdir(AUFS_PLINK_MAINT_DIR, NULL);
if (unlikely(!au_procfs_dir))
goto out;
entry = proc_create(AUFS_PLINK_MAINT_NAME, S_IFREG | S_IWUSR,
au_procfs_dir, &au_procfs_plm_fop);
if (unlikely(!entry))
goto out_dir;
err = 0;
goto out; /* success */
out_dir:
remove_proc_entry(AUFS_PLINK_MAINT_DIR, NULL);
out:
return err;
}
|
