/usr/src/aufs-4.9+20161219/fs/aufs/procfs.c is in aufs-dkms 4.9+20161219-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
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 | /*
* Copyright (C) 2010-2016 Junjiro R. Okajima
*
* This program, aufs is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/*
* 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);
hlist_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;
}
|