/usr/src/aufs-4.9+20161219/fs/aufs/dcsub.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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 | /*
* 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/>.
*/
/*
* sub-routines for dentry cache
*/
#include "aufs.h"
static void au_dpage_free(struct au_dpage *dpage)
{
int i;
struct dentry **p;
p = dpage->dentries;
for (i = 0; i < dpage->ndentry; i++)
dput(*p++);
au_delayed_free_page((unsigned long)dpage->dentries);
}
int au_dpages_init(struct au_dcsub_pages *dpages, gfp_t gfp)
{
int err;
void *p;
err = -ENOMEM;
dpages->dpages = kmalloc(sizeof(*dpages->dpages), gfp);
if (unlikely(!dpages->dpages))
goto out;
p = (void *)__get_free_page(gfp);
if (unlikely(!p))
goto out_dpages;
dpages->dpages[0].ndentry = 0;
dpages->dpages[0].dentries = p;
dpages->ndpage = 1;
return 0; /* success */
out_dpages:
au_delayed_kfree(dpages->dpages);
out:
return err;
}
void au_dpages_free(struct au_dcsub_pages *dpages)
{
int i;
struct au_dpage *p;
p = dpages->dpages;
for (i = 0; i < dpages->ndpage; i++)
au_dpage_free(p++);
au_delayed_kfree(dpages->dpages);
}
static int au_dpages_append(struct au_dcsub_pages *dpages,
struct dentry *dentry, gfp_t gfp)
{
int err, sz;
struct au_dpage *dpage;
void *p;
dpage = dpages->dpages + dpages->ndpage - 1;
sz = PAGE_SIZE / sizeof(dentry);
if (unlikely(dpage->ndentry >= sz)) {
AuLabel(new dpage);
err = -ENOMEM;
sz = dpages->ndpage * sizeof(*dpages->dpages);
p = au_kzrealloc(dpages->dpages, sz,
sz + sizeof(*dpages->dpages), gfp,
/*may_shrink*/0);
if (unlikely(!p))
goto out;
dpages->dpages = p;
dpage = dpages->dpages + dpages->ndpage;
p = (void *)__get_free_page(gfp);
if (unlikely(!p))
goto out;
dpage->ndentry = 0;
dpage->dentries = p;
dpages->ndpage++;
}
AuDebugOn(au_dcount(dentry) <= 0);
dpage->dentries[dpage->ndentry++] = dget_dlock(dentry);
return 0; /* success */
out:
return err;
}
/* todo: BAD approach */
/* copied from linux/fs/dcache.c */
enum d_walk_ret {
D_WALK_CONTINUE,
D_WALK_QUIT,
D_WALK_NORETRY,
D_WALK_SKIP,
};
extern void d_walk(struct dentry *parent, void *data,
enum d_walk_ret (*enter)(void *, struct dentry *),
void (*finish)(void *));
struct ac_dpages_arg {
int err;
struct au_dcsub_pages *dpages;
struct super_block *sb;
au_dpages_test test;
void *arg;
};
static enum d_walk_ret au_call_dpages_append(void *_arg, struct dentry *dentry)
{
enum d_walk_ret ret;
struct ac_dpages_arg *arg = _arg;
ret = D_WALK_CONTINUE;
if (dentry->d_sb == arg->sb
&& !IS_ROOT(dentry)
&& au_dcount(dentry) > 0
&& au_di(dentry)
&& (!arg->test || arg->test(dentry, arg->arg))) {
arg->err = au_dpages_append(arg->dpages, dentry, GFP_ATOMIC);
if (unlikely(arg->err))
ret = D_WALK_QUIT;
}
return ret;
}
int au_dcsub_pages(struct au_dcsub_pages *dpages, struct dentry *root,
au_dpages_test test, void *arg)
{
struct ac_dpages_arg args = {
.err = 0,
.dpages = dpages,
.sb = root->d_sb,
.test = test,
.arg = arg
};
d_walk(root, &args, au_call_dpages_append, NULL);
return args.err;
}
int au_dcsub_pages_rev(struct au_dcsub_pages *dpages, struct dentry *dentry,
int do_include, au_dpages_test test, void *arg)
{
int err;
err = 0;
write_seqlock(&rename_lock);
spin_lock(&dentry->d_lock);
if (do_include
&& au_dcount(dentry) > 0
&& (!test || test(dentry, arg)))
err = au_dpages_append(dpages, dentry, GFP_ATOMIC);
spin_unlock(&dentry->d_lock);
if (unlikely(err))
goto out;
/*
* RCU for vfsmount is unnecessary since this is a traverse in a single
* mount
*/
while (!IS_ROOT(dentry)) {
dentry = dentry->d_parent; /* rename_lock is locked */
spin_lock(&dentry->d_lock);
if (au_dcount(dentry) > 0
&& (!test || test(dentry, arg)))
err = au_dpages_append(dpages, dentry, GFP_ATOMIC);
spin_unlock(&dentry->d_lock);
if (unlikely(err))
break;
}
out:
write_sequnlock(&rename_lock);
return err;
}
static inline int au_dcsub_dpages_aufs(struct dentry *dentry, void *arg)
{
return au_di(dentry) && dentry->d_sb == arg;
}
int au_dcsub_pages_rev_aufs(struct au_dcsub_pages *dpages,
struct dentry *dentry, int do_include)
{
return au_dcsub_pages_rev(dpages, dentry, do_include,
au_dcsub_dpages_aufs, dentry->d_sb);
}
int au_test_subdir(struct dentry *d1, struct dentry *d2)
{
struct path path[2] = {
{
.dentry = d1
},
{
.dentry = d2
}
};
return path_is_under(path + 0, path + 1);
}
|