/usr/src/aufs-4.9+20161219/fs/aufs/sysrq.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 | /*
* Copyright (C) 2005-2016 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/>.
*/
/*
* magic sysrq hanlder
*/
/* #include <linux/sysrq.h> */
#include <linux/writeback.h>
#include "aufs.h"
/* ---------------------------------------------------------------------- */
static void sysrq_sb(struct super_block *sb)
{
char *plevel;
struct au_sbinfo *sbinfo;
struct file *file;
struct au_sphlhead *files;
struct au_finfo *finfo;
plevel = au_plevel;
au_plevel = KERN_WARNING;
/* since we define pr_fmt, call printk directly */
#define pr(str) printk(KERN_WARNING AUFS_NAME ": " str)
sbinfo = au_sbi(sb);
printk(KERN_WARNING "si=%lx\n", sysaufs_si_id(sbinfo));
pr("superblock\n");
au_dpri_sb(sb);
#if 0
pr("root dentry\n");
au_dpri_dentry(sb->s_root);
pr("root inode\n");
au_dpri_inode(d_inode(sb->s_root));
#endif
#if 0
do {
int err, i, j, ndentry;
struct au_dcsub_pages dpages;
struct au_dpage *dpage;
err = au_dpages_init(&dpages, GFP_ATOMIC);
if (unlikely(err))
break;
err = au_dcsub_pages(&dpages, sb->s_root, NULL, NULL);
if (!err)
for (i = 0; i < dpages.ndpage; i++) {
dpage = dpages.dpages + i;
ndentry = dpage->ndentry;
for (j = 0; j < ndentry; j++)
au_dpri_dentry(dpage->dentries[j]);
}
au_dpages_free(&dpages);
} while (0);
#endif
#if 1
{
struct inode *i;
pr("isolated inode\n");
spin_lock(&sb->s_inode_list_lock);
list_for_each_entry(i, &sb->s_inodes, i_sb_list) {
spin_lock(&i->i_lock);
if (1 || hlist_empty(&i->i_dentry))
au_dpri_inode(i);
spin_unlock(&i->i_lock);
}
spin_unlock(&sb->s_inode_list_lock);
}
#endif
pr("files\n");
files = &au_sbi(sb)->si_files;
spin_lock(&files->spin);
hlist_for_each_entry(finfo, &files->head, fi_hlist) {
umode_t mode;
file = finfo->fi_file;
mode = file_inode(file)->i_mode;
if (!special_file(mode))
au_dpri_file(file);
}
spin_unlock(&files->spin);
pr("done\n");
#undef pr
au_plevel = plevel;
}
/* ---------------------------------------------------------------------- */
/* module parameter */
static char *aufs_sysrq_key = "a";
module_param_named(sysrq, aufs_sysrq_key, charp, S_IRUGO);
MODULE_PARM_DESC(sysrq, "MagicSysRq key for " AUFS_NAME);
static void au_sysrq(int key __maybe_unused)
{
struct au_sbinfo *sbinfo;
lockdep_off();
au_sbilist_lock();
hlist_for_each_entry(sbinfo, &au_sbilist.head, si_list)
sysrq_sb(sbinfo->si_sb);
au_sbilist_unlock();
lockdep_on();
}
static struct sysrq_key_op au_sysrq_op = {
.handler = au_sysrq,
.help_msg = "Aufs",
.action_msg = "Aufs",
.enable_mask = SYSRQ_ENABLE_DUMP
};
/* ---------------------------------------------------------------------- */
int __init au_sysrq_init(void)
{
int err;
char key;
err = -1;
key = *aufs_sysrq_key;
if ('a' <= key && key <= 'z')
err = register_sysrq_key(key, &au_sysrq_op);
if (unlikely(err))
pr_err("err %d, sysrq=%c\n", err, key);
return err;
}
void au_sysrq_fin(void)
{
int err;
err = unregister_sysrq_key(*aufs_sysrq_key, &au_sysrq_op);
if (unlikely(err))
pr_err("err %d (ignored)\n", err);
}
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