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 <android-base/logging.h>
41#include <android-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
51using android::base::StringPrintf;
52
53namespace android {
54namespace vold {
55namespace ext4 {
56
57static const char* kResizefsPath = "/system/bin/resize2fs";
58#ifdef TARGET_USES_MKE2FS
59static const char* kMkfsPath = "/system/bin/mke2fs";
60#else
61static const char* kMkfsPath = "/system/bin/make_ext4fs";
62#endif
63static const char* kFsckPath = "/system/bin/e2fsck";
64
65bool IsSupported() {
66    return access(kMkfsPath, X_OK) == 0
67            && access(kFsckPath, X_OK) == 0
68            && IsFilesystemSupported("ext4");
69}
70
71status_t Check(const std::string& source, const std::string& target) {
72    // The following is shamelessly borrowed from fs_mgr.c, so it should be
73    // kept in sync with any changes over there.
74
75    const char* c_source = source.c_str();
76    const char* c_target = target.c_str();
77
78    int status;
79    int ret;
80    long tmpmnt_flags = MS_NOATIME | MS_NOEXEC | MS_NOSUID;
81    char *tmpmnt_opts = (char*) "nomblk_io_submit,errors=remount-ro";
82
83    /*
84     * First try to mount and unmount the filesystem.  We do this because
85     * the kernel is more efficient than e2fsck in running the journal and
86     * processing orphaned inodes, and on at least one device with a
87     * performance issue in the emmc firmware, it can take e2fsck 2.5 minutes
88     * to do what the kernel does in about a second.
89     *
90     * After mounting and unmounting the filesystem, run e2fsck, and if an
91     * error is recorded in the filesystem superblock, e2fsck will do a full
92     * check.  Otherwise, it does nothing.  If the kernel cannot mount the
93     * filesytsem due to an error, e2fsck is still run to do a full check
94     * fix the filesystem.
95     */
96    ret = mount(c_source, c_target, "ext4", tmpmnt_flags, tmpmnt_opts);
97    if (!ret) {
98        int i;
99        for (i = 0; i < 5; i++) {
100            // Try to umount 5 times before continuing on.
101            // Should we try rebooting if all attempts fail?
102            int result = umount(c_target);
103            if (result == 0) {
104                break;
105            }
106            ALOGW("%s(): umount(%s)=%d: %s\n", __func__, c_target, result, strerror(errno));
107            sleep(1);
108        }
109    }
110
111    /*
112     * Some system images do not have e2fsck for licensing reasons
113     * (e.g. recent SDK system images). Detect these and skip the check.
114     */
115    if (access(kFsckPath, X_OK)) {
116        ALOGD("Not running %s on %s (executable not in system image)\n",
117                kFsckPath, c_source);
118    } else {
119        ALOGD("Running %s on %s\n", kFsckPath, c_source);
120
121        std::vector<std::string> cmd;
122        cmd.push_back(kFsckPath);
123        cmd.push_back("-y");
124        cmd.push_back(c_source);
125
126        // ext4 devices are currently always trusted
127        return ForkExecvp(cmd, sFsckContext);
128    }
129
130    return 0;
131}
132
133status_t Mount(const std::string& source, const std::string& target, bool ro,
134        bool remount, bool executable) {
135    int rc;
136    unsigned long flags;
137
138    const char* c_source = source.c_str();
139    const char* c_target = target.c_str();
140
141    flags = MS_NOATIME | MS_NODEV | MS_NOSUID | MS_DIRSYNC;
142
143    flags |= (executable ? 0 : MS_NOEXEC);
144    flags |= (ro ? MS_RDONLY : 0);
145    flags |= (remount ? MS_REMOUNT : 0);
146
147    rc = mount(c_source, c_target, "ext4", flags, NULL);
148
149    if (rc && errno == EROFS) {
150        SLOGE("%s appears to be a read only filesystem - retrying mount RO", c_source);
151        flags |= MS_RDONLY;
152        rc = mount(c_source, c_target, "ext4", flags, NULL);
153    }
154
155    return rc;
156}
157
158status_t Resize(const std::string& source, unsigned long numSectors) {
159    std::vector<std::string> cmd;
160    cmd.push_back(kResizefsPath);
161    cmd.push_back("-f");
162    cmd.push_back(source);
163    cmd.push_back(StringPrintf("%lu", numSectors));
164
165    return ForkExecvp(cmd);
166}
167
168status_t Format(const std::string& source, unsigned long numSectors,
169        const std::string& target) {
170    std::vector<std::string> cmd;
171    cmd.push_back(kMkfsPath);
172
173#ifdef TARGET_USES_MKE2FS
174    cmd.push_back("-b");
175    cmd.push_back("4096");
176
177    cmd.push_back("-t");
178    cmd.push_back("ext4");
179
180    cmd.push_back("-M");
181    cmd.push_back(target);
182
183    cmd.push_back("-O");
184    cmd.push_back("^has_journal");
185
186    cmd.push_back(source);
187
188    if (numSectors)
189        cmd.push_back(StringPrintf("%lu", numSectors * (4096 / 512)));
190#else
191    cmd.push_back("-J");
192
193    cmd.push_back("-a");
194    cmd.push_back(target);
195
196    if (numSectors) {
197        cmd.push_back("-l");
198        cmd.push_back(StringPrintf("%lu", numSectors * 512));
199    }
200
201    // Always generate a real UUID
202    cmd.push_back("-u");
203    cmd.push_back(source);
204#endif
205
206    return ForkExecvp(cmd);
207}
208
209}  // namespace ext4
210}  // namespace vold
211}  // namespace android
212