1 /*
2 * Copyright (C) 2011 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include "ext4_utils/wipe.h"
18
19 #include "ext4_utils/ext4_utils.h"
20
21 #include <android-base/file.h>
22
23 #if WIPE_IS_SUPPORTED
24
25 #if defined(__linux__)
26
27 #include <linux/fs.h>
28 #include <sys/ioctl.h>
29
30 #ifndef BLKDISCARD
31 #define BLKDISCARD _IO(0x12,119)
32 #endif
33
34 #ifndef BLKSECDISCARD
35 #define BLKSECDISCARD _IO(0x12,125)
36 #endif
37
wipe_block_device(int fd,s64 len)38 int wipe_block_device(int fd, s64 len)
39 {
40 u64 range[2];
41 int ret;
42
43 if (!is_block_device_fd(fd)) {
44 // Wiping only makes sense on a block device.
45 return 0;
46 }
47
48 range[0] = 0;
49 range[1] = len;
50 ret = ioctl(fd, BLKSECDISCARD, &range);
51 if (ret < 0) {
52 range[0] = 0;
53 range[1] = len;
54 ret = ioctl(fd, BLKDISCARD, &range);
55 if (ret < 0) {
56 warn("Discard failed\n");
57 return 1;
58 } else {
59 char buf[4096] = {0};
60
61 if (!android::base::WriteFully(fd, buf, 4096)) {
62 warn("Writing zeros failed\n");
63 return 1;
64 }
65 fsync(fd);
66 warn("Wipe via secure discard failed, used discard instead\n");
67 return 0;
68 }
69 }
70
71 return 0;
72 }
73
74 #else /* __linux__ */
75 #error "Missing block device wiping implementation for this platform!"
76 #endif
77
78 #else /* WIPE_IS_SUPPORTED */
79
wipe_block_device(int fd,s64 len)80 int wipe_block_device(int fd __attribute__((unused)), s64 len __attribute__((unused)))
81 {
82 /* Wiping is not supported on this platform. */
83 return 1;
84 }
85
86 #endif /* WIPE_IS_SUPPORTED */
87