1 /*
2 * Copyright (C) 2015 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 "PublicVolume.h"
18
19 #include "AppFuseUtil.h"
20 #include "Utils.h"
21 #include "VolumeManager.h"
22 #include "fs/Exfat.h"
23 #include "fs/Vfat.h"
24
25 #include <android-base/logging.h>
26 #include <android-base/properties.h>
27 #include <android-base/stringprintf.h>
28 #include <cutils/fs.h>
29 #include <private/android_filesystem_config.h>
30 #include <utils/Timers.h>
31
32 #include <fcntl.h>
33 #include <stdlib.h>
34 #include <sys/mount.h>
35 #include <sys/stat.h>
36 #include <sys/sysmacros.h>
37 #include <sys/types.h>
38 #include <sys/wait.h>
39
40 using android::base::GetBoolProperty;
41 using android::base::StringPrintf;
42
43 namespace android {
44 namespace vold {
45
46 static const char* kSdcardFsPath = "/system/bin/sdcard";
47
48 static const char* kAsecPath = "/mnt/secure/asec";
49
PublicVolume(dev_t device)50 PublicVolume::PublicVolume(dev_t device) : VolumeBase(Type::kPublic), mDevice(device) {
51 setId(StringPrintf("public:%u,%u", major(device), minor(device)));
52 mDevPath = StringPrintf("/dev/block/vold/%s", getId().c_str());
53 mFuseMounted = false;
54 mUseSdcardFs = IsSdcardfsUsed();
55 }
56
~PublicVolume()57 PublicVolume::~PublicVolume() {}
58
readMetadata()59 status_t PublicVolume::readMetadata() {
60 status_t res = ReadMetadataUntrusted(mDevPath, &mFsType, &mFsUuid, &mFsLabel);
61
62 auto listener = getListener();
63 if (listener) listener->onVolumeMetadataChanged(getId(), mFsType, mFsUuid, mFsLabel);
64
65 return res;
66 }
67
initAsecStage()68 status_t PublicVolume::initAsecStage() {
69 std::string legacyPath(mRawPath + "/android_secure");
70 std::string securePath(mRawPath + "/.android_secure");
71
72 // Recover legacy secure path
73 if (!access(legacyPath.c_str(), R_OK | X_OK) && access(securePath.c_str(), R_OK | X_OK)) {
74 if (rename(legacyPath.c_str(), securePath.c_str())) {
75 PLOG(WARNING) << getId() << " failed to rename legacy ASEC dir";
76 }
77 }
78
79 if (TEMP_FAILURE_RETRY(mkdir(securePath.c_str(), 0700))) {
80 if (errno != EEXIST) {
81 PLOG(WARNING) << getId() << " creating ASEC stage failed";
82 return -errno;
83 }
84 }
85
86 BindMount(securePath, kAsecPath);
87
88 return OK;
89 }
90
doCreate()91 status_t PublicVolume::doCreate() {
92 return CreateDeviceNode(mDevPath, mDevice);
93 }
94
doDestroy()95 status_t PublicVolume::doDestroy() {
96 return DestroyDeviceNode(mDevPath);
97 }
98
doMount()99 status_t PublicVolume::doMount() {
100 bool isVisible = getMountFlags() & MountFlags::kVisible;
101 readMetadata();
102
103 if (mFsType == "vfat" && vfat::IsSupported()) {
104 if (vfat::Check(mDevPath)) {
105 LOG(ERROR) << getId() << " failed filesystem check";
106 return -EIO;
107 }
108 } else if (mFsType == "exfat" && exfat::IsSupported()) {
109 if (exfat::Check(mDevPath)) {
110 LOG(ERROR) << getId() << " failed filesystem check";
111 return -EIO;
112 }
113 } else {
114 LOG(ERROR) << getId() << " unsupported filesystem " << mFsType;
115 return -EIO;
116 }
117
118 // Use UUID as stable name, if available
119 std::string stableName = getId();
120 if (!mFsUuid.empty()) {
121 stableName = mFsUuid;
122 }
123
124 mRawPath = StringPrintf("/mnt/media_rw/%s", stableName.c_str());
125
126 mSdcardFsDefault = StringPrintf("/mnt/runtime/default/%s", stableName.c_str());
127 mSdcardFsRead = StringPrintf("/mnt/runtime/read/%s", stableName.c_str());
128 mSdcardFsWrite = StringPrintf("/mnt/runtime/write/%s", stableName.c_str());
129 mSdcardFsFull = StringPrintf("/mnt/runtime/full/%s", stableName.c_str());
130
131 setInternalPath(mRawPath);
132 if (isVisible) {
133 setPath(StringPrintf("/storage/%s", stableName.c_str()));
134 } else {
135 setPath(mRawPath);
136 }
137
138 if (fs_prepare_dir(mRawPath.c_str(), 0700, AID_ROOT, AID_ROOT)) {
139 PLOG(ERROR) << getId() << " failed to create mount points";
140 return -errno;
141 }
142
143 if (mFsType == "vfat") {
144 if (vfat::Mount(mDevPath, mRawPath, false, false, false, AID_ROOT,
145 (isVisible ? AID_MEDIA_RW : AID_EXTERNAL_STORAGE), 0007, true)) {
146 PLOG(ERROR) << getId() << " failed to mount " << mDevPath;
147 return -EIO;
148 }
149 } else if (mFsType == "exfat") {
150 if (exfat::Mount(mDevPath, mRawPath, AID_ROOT,
151 (isVisible ? AID_MEDIA_RW : AID_EXTERNAL_STORAGE), 0007)) {
152 PLOG(ERROR) << getId() << " failed to mount " << mDevPath;
153 return -EIO;
154 }
155 }
156
157 if (getMountFlags() & MountFlags::kPrimary) {
158 initAsecStage();
159 }
160
161 if (!isVisible) {
162 // Not visible to apps, so no need to spin up sdcardfs or FUSE
163 return OK;
164 }
165
166 if (mUseSdcardFs) {
167 if (fs_prepare_dir(mSdcardFsDefault.c_str(), 0700, AID_ROOT, AID_ROOT) ||
168 fs_prepare_dir(mSdcardFsRead.c_str(), 0700, AID_ROOT, AID_ROOT) ||
169 fs_prepare_dir(mSdcardFsWrite.c_str(), 0700, AID_ROOT, AID_ROOT) ||
170 fs_prepare_dir(mSdcardFsFull.c_str(), 0700, AID_ROOT, AID_ROOT)) {
171 PLOG(ERROR) << getId() << " failed to create sdcardfs mount points";
172 return -errno;
173 }
174
175 dev_t before = GetDevice(mSdcardFsFull);
176
177 int sdcardFsPid;
178 if (!(sdcardFsPid = fork())) {
179 if (getMountFlags() & MountFlags::kPrimary) {
180 // clang-format off
181 if (execl(kSdcardFsPath, kSdcardFsPath,
182 "-u", "1023", // AID_MEDIA_RW
183 "-g", "1023", // AID_MEDIA_RW
184 "-U", std::to_string(getMountUserId()).c_str(),
185 "-w",
186 mRawPath.c_str(),
187 stableName.c_str(),
188 NULL)) {
189 // clang-format on
190 PLOG(ERROR) << "Failed to exec";
191 }
192 } else {
193 // clang-format off
194 if (execl(kSdcardFsPath, kSdcardFsPath,
195 "-u", "1023", // AID_MEDIA_RW
196 "-g", "1023", // AID_MEDIA_RW
197 "-U", std::to_string(getMountUserId()).c_str(),
198 mRawPath.c_str(),
199 stableName.c_str(),
200 NULL)) {
201 // clang-format on
202 PLOG(ERROR) << "Failed to exec";
203 }
204 }
205
206 LOG(ERROR) << "sdcardfs exiting";
207 _exit(1);
208 }
209
210 if (sdcardFsPid == -1) {
211 PLOG(ERROR) << getId() << " failed to fork";
212 return -errno;
213 }
214
215 nsecs_t start = systemTime(SYSTEM_TIME_BOOTTIME);
216 while (before == GetDevice(mSdcardFsFull)) {
217 LOG(DEBUG) << "Waiting for sdcardfs to spin up...";
218 usleep(50000); // 50ms
219
220 nsecs_t now = systemTime(SYSTEM_TIME_BOOTTIME);
221 if (nanoseconds_to_milliseconds(now - start) > 5000) {
222 LOG(WARNING) << "Timed out while waiting for sdcardfs to spin up";
223 return -ETIMEDOUT;
224 }
225 }
226 /* sdcardfs will have exited already. The filesystem will still be running */
227 TEMP_FAILURE_RETRY(waitpid(sdcardFsPid, nullptr, 0));
228 }
229
230 bool isFuse = base::GetBoolProperty(kPropFuse, false);
231 if (isFuse) {
232 // We need to mount FUSE *after* sdcardfs, since the FUSE daemon may depend
233 // on sdcardfs being up.
234 LOG(INFO) << "Mounting public fuse volume";
235 android::base::unique_fd fd;
236 int user_id = getMountUserId();
237 int result = MountUserFuse(user_id, getInternalPath(), stableName, &fd);
238
239 if (result != 0) {
240 LOG(ERROR) << "Failed to mount public fuse volume";
241 doUnmount();
242 return -result;
243 }
244
245 mFuseMounted = true;
246 auto callback = getMountCallback();
247 if (callback) {
248 bool is_ready = false;
249 callback->onVolumeChecking(std::move(fd), getPath(), getInternalPath(), &is_ready);
250 if (!is_ready) {
251 LOG(ERROR) << "Failed to complete public volume mount";
252 doUnmount();
253 return -EIO;
254 }
255 }
256
257 ConfigureReadAheadForFuse(GetFuseMountPathForUser(user_id, stableName), 256u);
258
259 // See comment in model/EmulatedVolume.cpp
260 ConfigureMaxDirtyRatioForFuse(GetFuseMountPathForUser(user_id, stableName), 40u);
261 }
262
263 return OK;
264 }
265
doUnmount()266 status_t PublicVolume::doUnmount() {
267 // Unmount the storage before we kill the FUSE process. If we kill
268 // the FUSE process first, most file system operations will return
269 // ENOTCONN until the unmount completes. This is an exotic and unusual
270 // error code and might cause broken behaviour in applications.
271 KillProcessesUsingPath(getPath());
272
273 if (mFuseMounted) {
274 // Use UUID as stable name, if available
275 std::string stableName = getId();
276 if (!mFsUuid.empty()) {
277 stableName = mFsUuid;
278 }
279
280 if (UnmountUserFuse(getMountUserId(), getInternalPath(), stableName) != OK) {
281 PLOG(INFO) << "UnmountUserFuse failed on public fuse volume";
282 return -errno;
283 }
284
285 mFuseMounted = false;
286 }
287
288 ForceUnmount(kAsecPath);
289
290 if (mUseSdcardFs) {
291 ForceUnmount(mSdcardFsDefault);
292 ForceUnmount(mSdcardFsRead);
293 ForceUnmount(mSdcardFsWrite);
294 ForceUnmount(mSdcardFsFull);
295
296 rmdir(mSdcardFsDefault.c_str());
297 rmdir(mSdcardFsRead.c_str());
298 rmdir(mSdcardFsWrite.c_str());
299 rmdir(mSdcardFsFull.c_str());
300
301 mSdcardFsDefault.clear();
302 mSdcardFsRead.clear();
303 mSdcardFsWrite.clear();
304 mSdcardFsFull.clear();
305 }
306 ForceUnmount(mRawPath);
307 rmdir(mRawPath.c_str());
308 mRawPath.clear();
309
310 return OK;
311 }
312
doFormat(const std::string & fsType)313 status_t PublicVolume::doFormat(const std::string& fsType) {
314 bool useVfat = vfat::IsSupported();
315 bool useExfat = exfat::IsSupported();
316 status_t res = OK;
317
318 // Resolve the target filesystem type
319 if (fsType == "auto" && useVfat && useExfat) {
320 uint64_t size = 0;
321
322 res = GetBlockDevSize(mDevPath, &size);
323 if (res != OK) {
324 LOG(ERROR) << "Couldn't get device size " << mDevPath;
325 return res;
326 }
327
328 // If both vfat & exfat are supported use exfat for SDXC (>~32GiB) cards
329 if (size > 32896LL * 1024 * 1024) {
330 useVfat = false;
331 } else {
332 useExfat = false;
333 }
334 } else if (fsType == "vfat") {
335 useExfat = false;
336 } else if (fsType == "exfat") {
337 useVfat = false;
338 }
339
340 if (!useVfat && !useExfat) {
341 LOG(ERROR) << "Unsupported filesystem " << fsType;
342 return -EINVAL;
343 }
344
345 if (WipeBlockDevice(mDevPath) != OK) {
346 LOG(WARNING) << getId() << " failed to wipe";
347 }
348
349 if (useVfat) {
350 res = vfat::Format(mDevPath, 0);
351 } else if (useExfat) {
352 res = exfat::Format(mDevPath);
353 }
354
355 if (res != OK) {
356 LOG(ERROR) << getId() << " failed to format";
357 res = -errno;
358 }
359
360 return res;
361 }
362
363 } // namespace vold
364 } // namespace android
365