1 /*
2 * Copyright (C) 2012 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 <stdio.h>
18 #include <stdlib.h>
19 #include <fcntl.h>
20 #include <unistd.h>
21 #include <errno.h>
22 #include <string.h>
23 #include <dirent.h>
24 #include <errno.h>
25 #include <fcntl.h>
26 #include <vector>
27 #include <string>
28
29 #include <sys/types.h>
30 #include <sys/stat.h>
31 #include <sys/types.h>
32 #include <sys/mman.h>
33 #include <sys/mount.h>
34 #include <sys/wait.h>
35
36 #include <linux/kdev_t.h>
37
38 #define LOG_TAG "Vold"
39
40 #include <base/logging.h>
41 #include <base/stringprintf.h>
42 #include <cutils/log.h>
43 #include <cutils/properties.h>
44 #include <logwrap/logwrap.h>
45 #include <selinux/selinux.h>
46
47 #include "Ext4.h"
48 #include "Utils.h"
49 #include "VoldUtil.h"
50
51 using android::base::StringPrintf;
52
53 namespace android {
54 namespace vold {
55 namespace ext4 {
56
57 static const char* kResizefsPath = "/system/bin/resize2fs";
58 static const char* kMkfsPath = "/system/bin/make_ext4fs";
59 static const char* kFsckPath = "/system/bin/e2fsck";
60
IsSupported()61 bool IsSupported() {
62 return access(kMkfsPath, X_OK) == 0
63 && access(kFsckPath, X_OK) == 0
64 && IsFilesystemSupported("ext4");
65 }
66
Check(const std::string & source,const std::string & target)67 status_t Check(const std::string& source, const std::string& target) {
68 // The following is shamelessly borrowed from fs_mgr.c, so it should be
69 // kept in sync with any changes over there.
70
71 const char* c_source = source.c_str();
72 const char* c_target = target.c_str();
73
74 int status;
75 int ret;
76 long tmpmnt_flags = MS_NOATIME | MS_NOEXEC | MS_NOSUID;
77 char *tmpmnt_opts = (char*) "nomblk_io_submit,errors=remount-ro";
78
79 /*
80 * First try to mount and unmount the filesystem. We do this because
81 * the kernel is more efficient than e2fsck in running the journal and
82 * processing orphaned inodes, and on at least one device with a
83 * performance issue in the emmc firmware, it can take e2fsck 2.5 minutes
84 * to do what the kernel does in about a second.
85 *
86 * After mounting and unmounting the filesystem, run e2fsck, and if an
87 * error is recorded in the filesystem superblock, e2fsck will do a full
88 * check. Otherwise, it does nothing. If the kernel cannot mount the
89 * filesytsem due to an error, e2fsck is still run to do a full check
90 * fix the filesystem.
91 */
92 ret = mount(c_source, c_target, "ext4", tmpmnt_flags, tmpmnt_opts);
93 if (!ret) {
94 int i;
95 for (i = 0; i < 5; i++) {
96 // Try to umount 5 times before continuing on.
97 // Should we try rebooting if all attempts fail?
98 int result = umount(c_target);
99 if (result == 0) {
100 break;
101 }
102 ALOGW("%s(): umount(%s)=%d: %s\n", __func__, c_target, result, strerror(errno));
103 sleep(1);
104 }
105 }
106
107 /*
108 * Some system images do not have e2fsck for licensing reasons
109 * (e.g. recent SDK system images). Detect these and skip the check.
110 */
111 if (access(kFsckPath, X_OK)) {
112 ALOGD("Not running %s on %s (executable not in system image)\n",
113 kFsckPath, c_source);
114 } else {
115 ALOGD("Running %s on %s\n", kFsckPath, c_source);
116
117 std::vector<std::string> cmd;
118 cmd.push_back(kFsckPath);
119 cmd.push_back("-y");
120 cmd.push_back(c_source);
121
122 // ext4 devices are currently always trusted
123 return ForkExecvp(cmd, sFsckContext);
124 }
125
126 return 0;
127 }
128
Mount(const std::string & source,const std::string & target,bool ro,bool remount,bool executable)129 status_t Mount(const std::string& source, const std::string& target, bool ro,
130 bool remount, bool executable) {
131 int rc;
132 unsigned long flags;
133
134 const char* c_source = source.c_str();
135 const char* c_target = target.c_str();
136
137 flags = MS_NOATIME | MS_NODEV | MS_NOSUID | MS_DIRSYNC;
138
139 flags |= (executable ? 0 : MS_NOEXEC);
140 flags |= (ro ? MS_RDONLY : 0);
141 flags |= (remount ? MS_REMOUNT : 0);
142
143 rc = mount(c_source, c_target, "ext4", flags, NULL);
144
145 if (rc && errno == EROFS) {
146 SLOGE("%s appears to be a read only filesystem - retrying mount RO", c_source);
147 flags |= MS_RDONLY;
148 rc = mount(c_source, c_target, "ext4", flags, NULL);
149 }
150
151 return rc;
152 }
153
Resize(const std::string & source,unsigned int numSectors)154 status_t Resize(const std::string& source, unsigned int numSectors) {
155 std::vector<std::string> cmd;
156 cmd.push_back(kResizefsPath);
157 cmd.push_back("-f");
158 cmd.push_back(source);
159 cmd.push_back(StringPrintf("%u", numSectors));
160
161 return ForkExecvp(cmd);
162 }
163
Format(const std::string & source,unsigned int numSectors,const std::string & target)164 status_t Format(const std::string& source, unsigned int numSectors,
165 const std::string& target) {
166 std::vector<std::string> cmd;
167 cmd.push_back(kMkfsPath);
168 cmd.push_back("-J");
169
170 cmd.push_back("-a");
171 cmd.push_back(target);
172
173 if (numSectors) {
174 cmd.push_back("-l");
175 cmd.push_back(StringPrintf("%u", numSectors * 512));
176 }
177
178 // Always generate a real UUID
179 cmd.push_back("-u");
180 cmd.push_back(source);
181
182 return ForkExecvp(cmd);
183 }
184
185 } // namespace ext4
186 } // namespace vold
187 } // namespace android
188