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/properties.h>
42#include <android-base/stringprintf.h>
43#include <cutils/log.h>
44#include <cutils/properties.h>
45#include <logwrap/logwrap.h>
46#include <selinux/selinux.h>
47
48#include "Ext4.h"
49#include "Ext4Crypt.h"
50#include "Utils.h"
51#include "VoldUtil.h"
52
53using android::base::StringPrintf;
54
55namespace android {
56namespace vold {
57namespace ext4 {
58
59static const char* kResizefsPath = "/system/bin/resize2fs";
60static const char* kMkfsPath = "/system/bin/mke2fs";
61static const char* kFsckPath = "/system/bin/e2fsck";
62
63bool IsSupported() {
64    return access(kMkfsPath, X_OK) == 0
65            && access(kFsckPath, X_OK) == 0
66            && IsFilesystemSupported("ext4");
67}
68
69status_t Check(const std::string& source, const std::string& target) {
70    // The following is shamelessly borrowed from fs_mgr.c, so it should be
71    // kept in sync with any changes over there.
72
73    const char* c_source = source.c_str();
74    const char* c_target = target.c_str();
75
76    int status;
77    int ret;
78    long tmpmnt_flags = MS_NOATIME | MS_NOEXEC | MS_NOSUID;
79    char *tmpmnt_opts = (char*) "nomblk_io_submit,errors=remount-ro";
80
81    /*
82     * First try to mount and unmount the filesystem.  We do this because
83     * the kernel is more efficient than e2fsck in running the journal and
84     * processing orphaned inodes, and on at least one device with a
85     * performance issue in the emmc firmware, it can take e2fsck 2.5 minutes
86     * to do what the kernel does in about a second.
87     *
88     * After mounting and unmounting the filesystem, run e2fsck, and if an
89     * error is recorded in the filesystem superblock, e2fsck will do a full
90     * check.  Otherwise, it does nothing.  If the kernel cannot mount the
91     * filesytsem due to an error, e2fsck is still run to do a full check
92     * fix the filesystem.
93     */
94    ret = mount(c_source, c_target, "ext4", tmpmnt_flags, tmpmnt_opts);
95    if (!ret) {
96        int i;
97        for (i = 0; i < 5; i++) {
98            // Try to umount 5 times before continuing on.
99            // Should we try rebooting if all attempts fail?
100            int result = umount(c_target);
101            if (result == 0) {
102                break;
103            }
104            ALOGW("%s(): umount(%s)=%d: %s\n", __func__, c_target, result, strerror(errno));
105            sleep(1);
106        }
107    }
108
109    /*
110     * Some system images do not have e2fsck for licensing reasons
111     * (e.g. recent SDK system images). Detect these and skip the check.
112     */
113    if (access(kFsckPath, X_OK)) {
114        ALOGD("Not running %s on %s (executable not in system image)\n",
115                kFsckPath, c_source);
116    } else {
117        ALOGD("Running %s on %s\n", kFsckPath, c_source);
118
119        std::vector<std::string> cmd;
120        cmd.push_back(kFsckPath);
121        cmd.push_back("-y");
122        cmd.push_back(c_source);
123
124        // ext4 devices are currently always trusted
125        return ForkExecvp(cmd, sFsckContext);
126    }
127
128    return 0;
129}
130
131status_t Mount(const std::string& source, const std::string& target, bool ro,
132        bool remount, bool executable) {
133    int rc;
134    unsigned long flags;
135
136    const char* c_source = source.c_str();
137    const char* c_target = target.c_str();
138
139    flags = MS_NOATIME | MS_NODEV | MS_NOSUID | MS_DIRSYNC;
140
141    flags |= (executable ? 0 : MS_NOEXEC);
142    flags |= (ro ? MS_RDONLY : 0);
143    flags |= (remount ? MS_REMOUNT : 0);
144
145    rc = mount(c_source, c_target, "ext4", flags, NULL);
146
147    if (rc && errno == EROFS) {
148        SLOGE("%s appears to be a read only filesystem - retrying mount RO", c_source);
149        flags |= MS_RDONLY;
150        rc = mount(c_source, c_target, "ext4", flags, NULL);
151    }
152
153    return rc;
154}
155
156status_t Resize(const std::string& source, unsigned long numSectors) {
157    std::vector<std::string> cmd;
158    cmd.push_back(kResizefsPath);
159    cmd.push_back("-f");
160    cmd.push_back(source);
161    cmd.push_back(StringPrintf("%lu", numSectors));
162
163    return ForkExecvp(cmd);
164}
165
166status_t Format(const std::string& source, unsigned long numSectors,
167        const std::string& target) {
168    std::vector<std::string> cmd;
169    cmd.push_back(kMkfsPath);
170
171    cmd.push_back("-b");
172    cmd.push_back("4096");
173
174    cmd.push_back("-t");
175    cmd.push_back("ext4");
176
177    cmd.push_back("-M");
178    cmd.push_back(target);
179
180    std::string options("has_journal");
181    if (android::base::GetBoolProperty("vold.has_quota", false)) {
182        options += ",quota";
183    }
184    if (e4crypt_is_native()) {
185        options += ",encrypt";
186    }
187
188    cmd.push_back("-O");
189    cmd.push_back(options);
190
191    cmd.push_back(source);
192
193    if (numSectors) {
194        cmd.push_back(StringPrintf("%lu", numSectors * (4096 / 512)));
195    }
196
197    return ForkExecvp(cmd);
198}
199
200}  // namespace ext4
201}  // namespace vold
202}  // namespace android
203