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
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
|
// SPDX-License-Identifier: GPL-2.0
#include <linux/quotaops.h>
#include <linux/uuid.h>
#include "ext4.h"
#include "xattr.h"
#include "ext4_jbd2.h"
static void ext4_fname_from_fscrypt_name(struct ext4_filename *dst,
const struct fscrypt_name *src)
{
memset(dst, 0, sizeof(*dst));
dst->usr_fname = src->usr_fname;
dst->disk_name = src->disk_name;
dst->hinfo.hash = src->hash;
dst->hinfo.minor_hash = src->minor_hash;
dst->crypto_buf = src->crypto_buf;
}
int ext4_fname_setup_filename(struct inode *dir, const struct qstr *iname,
int lookup, struct ext4_filename *fname)
{
struct fscrypt_name name;
int err;
err = fscrypt_setup_filename(dir, iname, lookup, &name);
if (err)
return err;
ext4_fname_from_fscrypt_name(fname, &name);
#if IS_ENABLED(CONFIG_UNICODE)
err = ext4_fname_setup_ci_filename(dir, iname, fname);
#endif
return err;
}
int ext4_fname_prepare_lookup(struct inode *dir, struct dentry *dentry,
struct ext4_filename *fname)
{
struct fscrypt_name name;
int err;
err = fscrypt_prepare_lookup(dir, dentry, &name);
if (err)
return err;
ext4_fname_from_fscrypt_name(fname, &name);
#if IS_ENABLED(CONFIG_UNICODE)
err = ext4_fname_setup_ci_filename(dir, &dentry->d_name, fname);
#endif
return err;
}
void ext4_fname_free_filename(struct ext4_filename *fname)
{
struct fscrypt_name name;
name.crypto_buf = fname->crypto_buf;
fscrypt_free_filename(&name);
fname->crypto_buf.name = NULL;
fname->usr_fname = NULL;
fname->disk_name.name = NULL;
#if IS_ENABLED(CONFIG_UNICODE)
kfree(fname->cf_name.name);
fname->cf_name.name = NULL;
#endif
}
static bool uuid_is_zero(__u8 u[16])
{
int i;
for (i = 0; i < 16; i++)
if (u[i])
return false;
return true;
}
int ext4_ioctl_get_encryption_pwsalt(struct file *filp, void __user *arg)
{
struct super_block *sb = file_inode(filp)->i_sb;
struct ext4_sb_info *sbi = EXT4_SB(sb);
int err, err2;
handle_t *handle;
if (!ext4_has_feature_encrypt(sb))
return -EOPNOTSUPP;
if (uuid_is_zero(sbi->s_es->s_encrypt_pw_salt)) {
err = mnt_want_write_file(filp);
if (err)
return err;
handle = ext4_journal_start_sb(sb, EXT4_HT_MISC, 1);
if (IS_ERR(handle)) {
err = PTR_ERR(handle);
goto pwsalt_err_exit;
}
err = ext4_journal_get_write_access(handle, sb, sbi->s_sbh,
EXT4_JTR_NONE);
if (err)
goto pwsalt_err_journal;
lock_buffer(sbi->s_sbh);
generate_random_uuid(sbi->s_es->s_encrypt_pw_salt);
ext4_superblock_csum_set(sb);
unlock_buffer(sbi->s_sbh);
err = ext4_handle_dirty_metadata(handle, NULL, sbi->s_sbh);
pwsalt_err_journal:
err2 = ext4_journal_stop(handle);
if (err2 && !err)
err = err2;
pwsalt_err_exit:
mnt_drop_write_file(filp);
if (err)
return err;
}
if (copy_to_user(arg, sbi->s_es->s_encrypt_pw_salt, 16))
return -EFAULT;
return 0;
}
static int ext4_get_context(struct inode *inode, void *ctx, size_t len)
{
return ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, ctx, len);
}
static int ext4_set_context(struct inode *inode, const void *ctx, size_t len,
void *fs_data)
{
handle_t *handle = fs_data;
int res, res2, credits, retries = 0;
/*
* Encrypting the root directory is not allowed because e2fsck expects
* lost+found to exist and be unencrypted, and encrypting the root
* directory would imply encrypting the lost+found directory as well as
* the filename "lost+found" itself.
*/
if (inode->i_ino == EXT4_ROOT_INO)
return -EPERM;
if (WARN_ON_ONCE(IS_DAX(inode) && i_size_read(inode)))
return -EINVAL;
if (ext4_test_inode_flag(inode, EXT4_INODE_DAX))
return -EOPNOTSUPP;
res = ext4_convert_inline_data(inode);
if (res)
return res;
/*
* If a journal handle was specified, then the encryption context is
* being set on a new inode via inheritance and is part of a larger
* transaction to create the inode. Otherwise the encryption context is
* being set on an existing inode in its own transaction. Only in the
* latter case should the "retry on ENOSPC" logic be used.
*/
if (handle) {
res = ext4_xattr_set_handle(handle, inode,
EXT4_XATTR_INDEX_ENCRYPTION,
EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
ctx, len, 0);
if (!res) {
ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
ext4_clear_inode_state(inode,
EXT4_STATE_MAY_INLINE_DATA);
/*
* Update inode->i_flags - S_ENCRYPTED will be enabled,
* S_DAX may be disabled
*/
ext4_set_inode_flags(inode, false);
}
return res;
}
res = dquot_initialize(inode);
if (res)
return res;
retry:
res = ext4_xattr_set_credits(inode, len, false /* is_create */,
&credits);
if (res)
return res;
handle = ext4_journal_start(inode, EXT4_HT_MISC, credits);
if (IS_ERR(handle))
return PTR_ERR(handle);
res = ext4_xattr_set_handle(handle, inode, EXT4_XATTR_INDEX_ENCRYPTION,
EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
ctx, len, 0);
if (!res) {
ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
/*
* Update inode->i_flags - S_ENCRYPTED will be enabled,
* S_DAX may be disabled
*/
ext4_set_inode_flags(inode, false);
res = ext4_mark_inode_dirty(handle, inode);
if (res)
EXT4_ERROR_INODE(inode, "Failed to mark inode dirty");
}
res2 = ext4_journal_stop(handle);
if (res == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
goto retry;
if (!res)
res = res2;
return res;
}
static const union fscrypt_policy *ext4_get_dummy_policy(struct super_block *sb)
{
return EXT4_SB(sb)->s_dummy_enc_policy.policy;
}
static bool ext4_has_stable_inodes(struct super_block *sb)
{
return ext4_has_feature_stable_inodes(sb);
}
static void ext4_get_ino_and_lblk_bits(struct super_block *sb,
int *ino_bits_ret, int *lblk_bits_ret)
{
*ino_bits_ret = 8 * sizeof(EXT4_SB(sb)->s_es->s_inodes_count);
*lblk_bits_ret = 8 * sizeof(ext4_lblk_t);
}
const struct fscrypt_operations ext4_cryptops = {
.key_prefix = "ext4:",
.get_context = ext4_get_context,
.set_context = ext4_set_context,
.get_dummy_policy = ext4_get_dummy_policy,
.empty_dir = ext4_empty_dir,
.has_stable_inodes = ext4_has_stable_inodes,
.get_ino_and_lblk_bits = ext4_get_ino_and_lblk_bits,
};
|
