1 /*
2 * Copyright (C) 2008 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 #define ATRACE_TAG ATRACE_TAG_PACKAGE_MANAGER
18
19 #include <dirent.h>
20 #include <errno.h>
21 #include <fcntl.h>
22 #include <limits.h>
23 #include <mntent.h>
24 #include <stdio.h>
25 #include <stdlib.h>
26 #include <string.h>
27 #include <sys/ioctl.h>
28 #include <sys/mount.h>
29 #include <sys/stat.h>
30 #include <sys/sysmacros.h>
31 #include <sys/types.h>
32 #include <sys/wait.h>
33 #include <unistd.h>
34 #include <array>
35
36 #include <linux/kdev_t.h>
37
38 #include <android-base/file.h>
39 #include <android-base/logging.h>
40 #include <android-base/parseint.h>
41 #include <android-base/properties.h>
42 #include <android-base/stringprintf.h>
43 #include <android-base/strings.h>
44 #include <async_safe/log.h>
45
46 #include <cutils/fs.h>
47 #include <utils/Trace.h>
48
49 #include <selinux/android.h>
50
51 #include <sysutils/NetlinkEvent.h>
52
53 #include <private/android_filesystem_config.h>
54
55 #include <fscrypt/fscrypt.h>
56 #include <libdm/dm.h>
57
58 #include "AppFuseUtil.h"
59 #include "FsCrypt.h"
60 #include "Loop.h"
61 #include "NetlinkManager.h"
62 #include "Process.h"
63 #include "Utils.h"
64 #include "VoldNativeService.h"
65 #include "VoldUtil.h"
66 #include "VolumeManager.h"
67 #include "fs/Ext4.h"
68 #include "fs/Vfat.h"
69 #include "model/EmulatedVolume.h"
70 #include "model/ObbVolume.h"
71 #include "model/PrivateVolume.h"
72 #include "model/PublicVolume.h"
73 #include "model/StubVolume.h"
74
75 using android::OK;
76 using android::base::GetBoolProperty;
77 using android::base::StartsWith;
78 using android::base::StringAppendF;
79 using android::base::StringPrintf;
80 using android::base::unique_fd;
81 using android::vold::BindMount;
82 using android::vold::CreateDir;
83 using android::vold::DeleteDirContents;
84 using android::vold::DeleteDirContentsAndDir;
85 using android::vold::EnsureDirExists;
86 using android::vold::GetFuseMountPathForUser;
87 using android::vold::IsFilesystemSupported;
88 using android::vold::IsSdcardfsUsed;
89 using android::vold::IsVirtioBlkDevice;
90 using android::vold::PrepareAndroidDirs;
91 using android::vold::PrepareAppDirFromRoot;
92 using android::vold::PrivateVolume;
93 using android::vold::PublicVolume;
94 using android::vold::Symlink;
95 using android::vold::Unlink;
96 using android::vold::UnmountTree;
97 using android::vold::VoldNativeService;
98 using android::vold::VolumeBase;
99
100 static const char* kPathVirtualDisk = "/data/misc/vold/virtual_disk";
101
102 static const char* kPropVirtualDisk = "persist.sys.virtual_disk";
103
104 /* 512MiB is large enough for testing purposes */
105 static const unsigned int kSizeVirtualDisk = 536870912;
106
107 static const unsigned int kMajorBlockMmc = 179;
108
109 using ScanProcCallback = bool(*)(uid_t uid, pid_t pid, int nsFd, const char* name, void* params);
110
111 VolumeManager* VolumeManager::sInstance = NULL;
112
Instance()113 VolumeManager* VolumeManager::Instance() {
114 if (!sInstance) sInstance = new VolumeManager();
115 return sInstance;
116 }
117
VolumeManager()118 VolumeManager::VolumeManager() {
119 mDebug = false;
120 mNextObbId = 0;
121 mNextStubId = 0;
122 // For security reasons, assume that a secure keyguard is
123 // showing until we hear otherwise
124 mSecureKeyguardShowing = true;
125 }
126
~VolumeManager()127 VolumeManager::~VolumeManager() {}
128
updateVirtualDisk()129 int VolumeManager::updateVirtualDisk() {
130 ATRACE_NAME("VolumeManager::updateVirtualDisk");
131 if (GetBoolProperty(kPropVirtualDisk, false)) {
132 if (access(kPathVirtualDisk, F_OK) != 0) {
133 Loop::createImageFile(kPathVirtualDisk, kSizeVirtualDisk / 512);
134 }
135
136 if (mVirtualDisk == nullptr) {
137 if (Loop::create(kPathVirtualDisk, mVirtualDiskPath) != 0) {
138 LOG(ERROR) << "Failed to create virtual disk";
139 return -1;
140 }
141
142 struct stat buf;
143 if (stat(mVirtualDiskPath.c_str(), &buf) < 0) {
144 PLOG(ERROR) << "Failed to stat " << mVirtualDiskPath;
145 return -1;
146 }
147
148 auto disk = new android::vold::Disk(
149 "virtual", buf.st_rdev, "virtual",
150 android::vold::Disk::Flags::kAdoptable | android::vold::Disk::Flags::kSd);
151 mVirtualDisk = std::shared_ptr<android::vold::Disk>(disk);
152 handleDiskAdded(mVirtualDisk);
153 }
154 } else {
155 if (mVirtualDisk != nullptr) {
156 dev_t device = mVirtualDisk->getDevice();
157 handleDiskRemoved(device);
158
159 Loop::destroyByDevice(mVirtualDiskPath.c_str());
160 mVirtualDisk = nullptr;
161 }
162
163 if (access(kPathVirtualDisk, F_OK) == 0) {
164 unlink(kPathVirtualDisk);
165 }
166 }
167 return 0;
168 }
169
setDebug(bool enable)170 int VolumeManager::setDebug(bool enable) {
171 mDebug = enable;
172 return 0;
173 }
174
start()175 int VolumeManager::start() {
176 ATRACE_NAME("VolumeManager::start");
177
178 // Always start from a clean slate by unmounting everything in
179 // directories that we own, in case we crashed.
180 unmountAll();
181
182 Loop::destroyAll();
183
184 // Assume that we always have an emulated volume on internal
185 // storage; the framework will decide if it should be mounted.
186 CHECK(mInternalEmulatedVolumes.empty());
187
188 auto vol = std::shared_ptr<android::vold::VolumeBase>(
189 new android::vold::EmulatedVolume("/data/media", 0));
190 vol->setMountUserId(0);
191 vol->create();
192 mInternalEmulatedVolumes.push_back(vol);
193
194 // Consider creating a virtual disk
195 updateVirtualDisk();
196
197 return 0;
198 }
199
handleBlockEvent(NetlinkEvent * evt)200 void VolumeManager::handleBlockEvent(NetlinkEvent* evt) {
201 std::lock_guard<std::mutex> lock(mLock);
202
203 if (mDebug) {
204 LOG(DEBUG) << "----------------";
205 LOG(DEBUG) << "handleBlockEvent with action " << (int)evt->getAction();
206 evt->dump();
207 }
208
209 std::string eventPath(evt->findParam("DEVPATH") ? evt->findParam("DEVPATH") : "");
210 std::string devType(evt->findParam("DEVTYPE") ? evt->findParam("DEVTYPE") : "");
211
212 if (devType != "disk") return;
213
214 int major = std::stoi(evt->findParam("MAJOR"));
215 int minor = std::stoi(evt->findParam("MINOR"));
216 dev_t device = makedev(major, minor);
217
218 switch (evt->getAction()) {
219 case NetlinkEvent::Action::kAdd: {
220 for (const auto& source : mDiskSources) {
221 if (source->matches(eventPath)) {
222 // For now, assume that MMC and virtio-blk (the latter is
223 // specific to virtual platforms; see Utils.cpp for details)
224 // devices are SD, and that everything else is USB
225 int flags = source->getFlags();
226 if (major == kMajorBlockMmc || IsVirtioBlkDevice(major)) {
227 flags |= android::vold::Disk::Flags::kSd;
228 } else {
229 flags |= android::vold::Disk::Flags::kUsb;
230 }
231
232 auto disk =
233 new android::vold::Disk(eventPath, device, source->getNickname(), flags);
234 handleDiskAdded(std::shared_ptr<android::vold::Disk>(disk));
235 break;
236 }
237 }
238 break;
239 }
240 case NetlinkEvent::Action::kChange: {
241 LOG(VERBOSE) << "Disk at " << major << ":" << minor << " changed";
242 handleDiskChanged(device);
243 break;
244 }
245 case NetlinkEvent::Action::kRemove: {
246 handleDiskRemoved(device);
247 break;
248 }
249 default: {
250 LOG(WARNING) << "Unexpected block event action " << (int)evt->getAction();
251 break;
252 }
253 }
254 }
255
handleDiskAdded(const std::shared_ptr<android::vold::Disk> & disk)256 void VolumeManager::handleDiskAdded(const std::shared_ptr<android::vold::Disk>& disk) {
257 // For security reasons, if secure keyguard is showing, wait
258 // until the user unlocks the device to actually touch it
259 // Additionally, wait until user 0 is actually started, since we need
260 // the user to be up before we can mount a FUSE daemon to handle the disk.
261 bool userZeroStarted = mStartedUsers.find(0) != mStartedUsers.end();
262 if (mSecureKeyguardShowing) {
263 LOG(INFO) << "Found disk at " << disk->getEventPath()
264 << " but delaying scan due to secure keyguard";
265 mPendingDisks.push_back(disk);
266 } else if (!userZeroStarted) {
267 LOG(INFO) << "Found disk at " << disk->getEventPath()
268 << " but delaying scan due to user zero not having started";
269 mPendingDisks.push_back(disk);
270 } else {
271 disk->create();
272 mDisks.push_back(disk);
273 }
274 }
275
handleDiskChanged(dev_t device)276 void VolumeManager::handleDiskChanged(dev_t device) {
277 for (const auto& disk : mDisks) {
278 if (disk->getDevice() == device) {
279 disk->readMetadata();
280 disk->readPartitions();
281 }
282 }
283
284 // For security reasons, we ignore all pending disks, since
285 // we'll scan them once the device is unlocked
286 }
287
handleDiskRemoved(dev_t device)288 void VolumeManager::handleDiskRemoved(dev_t device) {
289 auto i = mDisks.begin();
290 while (i != mDisks.end()) {
291 if ((*i)->getDevice() == device) {
292 (*i)->destroy();
293 i = mDisks.erase(i);
294 } else {
295 ++i;
296 }
297 }
298 auto j = mPendingDisks.begin();
299 while (j != mPendingDisks.end()) {
300 if ((*j)->getDevice() == device) {
301 j = mPendingDisks.erase(j);
302 } else {
303 ++j;
304 }
305 }
306 }
307
addDiskSource(const std::shared_ptr<DiskSource> & diskSource)308 void VolumeManager::addDiskSource(const std::shared_ptr<DiskSource>& diskSource) {
309 std::lock_guard<std::mutex> lock(mLock);
310 mDiskSources.push_back(diskSource);
311 }
312
findDisk(const std::string & id)313 std::shared_ptr<android::vold::Disk> VolumeManager::findDisk(const std::string& id) {
314 for (auto disk : mDisks) {
315 if (disk->getId() == id) {
316 return disk;
317 }
318 }
319 return nullptr;
320 }
321
findVolume(const std::string & id)322 std::shared_ptr<android::vold::VolumeBase> VolumeManager::findVolume(const std::string& id) {
323 for (const auto& vol : mInternalEmulatedVolumes) {
324 if (vol->getId() == id) {
325 return vol;
326 }
327 }
328 for (const auto& disk : mDisks) {
329 auto vol = disk->findVolume(id);
330 if (vol != nullptr) {
331 return vol;
332 }
333 }
334 for (const auto& vol : mObbVolumes) {
335 if (vol->getId() == id) {
336 return vol;
337 }
338 }
339 return nullptr;
340 }
341
listVolumes(android::vold::VolumeBase::Type type,std::list<std::string> & list) const342 void VolumeManager::listVolumes(android::vold::VolumeBase::Type type,
343 std::list<std::string>& list) const {
344 list.clear();
345 for (const auto& disk : mDisks) {
346 disk->listVolumes(type, list);
347 }
348 }
349
forgetPartition(const std::string & partGuid,const std::string & fsUuid)350 bool VolumeManager::forgetPartition(const std::string& partGuid, const std::string& fsUuid) {
351 std::string normalizedGuid;
352 if (android::vold::NormalizeHex(partGuid, normalizedGuid)) {
353 LOG(WARNING) << "Invalid GUID " << partGuid;
354 return false;
355 }
356
357 std::string keyPath = android::vold::BuildKeyPath(normalizedGuid);
358 if (unlink(keyPath.c_str()) != 0) {
359 LOG(ERROR) << "Failed to unlink " << keyPath;
360 return false;
361 }
362 return true;
363 }
364
destroyEmulatedVolumesForUser(userid_t userId)365 void VolumeManager::destroyEmulatedVolumesForUser(userid_t userId) {
366 // Destroy and remove all unstacked EmulatedVolumes for the user
367 auto i = mInternalEmulatedVolumes.begin();
368 while (i != mInternalEmulatedVolumes.end()) {
369 auto vol = *i;
370 if (vol->getMountUserId() == userId) {
371 vol->destroy();
372 i = mInternalEmulatedVolumes.erase(i);
373 } else {
374 i++;
375 }
376 }
377
378 // Destroy and remove all stacked EmulatedVolumes for the user on each mounted private volume
379 std::list<std::string> private_vols;
380 listVolumes(VolumeBase::Type::kPrivate, private_vols);
381 for (const std::string& id : private_vols) {
382 PrivateVolume* pvol = static_cast<PrivateVolume*>(findVolume(id).get());
383 std::list<std::shared_ptr<VolumeBase>> vols_to_remove;
384 if (pvol->getState() == VolumeBase::State::kMounted) {
385 for (const auto& vol : pvol->getVolumes()) {
386 if (vol->getMountUserId() == userId) {
387 vols_to_remove.push_back(vol);
388 }
389 }
390 for (const auto& vol : vols_to_remove) {
391 vol->destroy();
392 pvol->removeVolume(vol);
393 }
394 } // else EmulatedVolumes will be destroyed on VolumeBase#unmount
395 }
396 }
397
createEmulatedVolumesForUser(userid_t userId)398 void VolumeManager::createEmulatedVolumesForUser(userid_t userId) {
399 // Create unstacked EmulatedVolumes for the user
400 auto vol = std::shared_ptr<android::vold::VolumeBase>(
401 new android::vold::EmulatedVolume("/data/media", userId));
402 vol->setMountUserId(userId);
403 mInternalEmulatedVolumes.push_back(vol);
404 vol->create();
405
406 // Create stacked EmulatedVolumes for the user on each PrivateVolume
407 std::list<std::string> private_vols;
408 listVolumes(VolumeBase::Type::kPrivate, private_vols);
409 for (const std::string& id : private_vols) {
410 PrivateVolume* pvol = static_cast<PrivateVolume*>(findVolume(id).get());
411 if (pvol->getState() == VolumeBase::State::kMounted) {
412 auto evol =
413 std::shared_ptr<android::vold::VolumeBase>(new android::vold::EmulatedVolume(
414 pvol->getPath() + "/media", pvol->getRawDevice(), pvol->getFsUuid(),
415 userId));
416 evol->setMountUserId(userId);
417 pvol->addVolume(evol);
418 evol->create();
419 } // else EmulatedVolumes will be created per user when on PrivateVolume#doMount
420 }
421 }
422
getSharedStorageUser(userid_t userId)423 userid_t VolumeManager::getSharedStorageUser(userid_t userId) {
424 if (mSharedStorageUser.find(userId) == mSharedStorageUser.end()) {
425 return USER_UNKNOWN;
426 }
427 return mSharedStorageUser.at(userId);
428 }
429
onUserAdded(userid_t userId,int userSerialNumber,userid_t sharesStorageWithUserId)430 int VolumeManager::onUserAdded(userid_t userId, int userSerialNumber,
431 userid_t sharesStorageWithUserId) {
432 LOG(INFO) << "onUserAdded: " << userId;
433
434 mAddedUsers[userId] = userSerialNumber;
435 if (sharesStorageWithUserId != USER_UNKNOWN) {
436 mSharedStorageUser[userId] = sharesStorageWithUserId;
437 }
438 return 0;
439 }
440
onUserRemoved(userid_t userId)441 int VolumeManager::onUserRemoved(userid_t userId) {
442 LOG(INFO) << "onUserRemoved: " << userId;
443
444 onUserStopped(userId);
445 mAddedUsers.erase(userId);
446 mSharedStorageUser.erase(userId);
447 return 0;
448 }
449
onUserStarted(userid_t userId)450 int VolumeManager::onUserStarted(userid_t userId) {
451 LOG(INFO) << "onUserStarted: " << userId;
452
453 if (mStartedUsers.find(userId) == mStartedUsers.end()) {
454 createEmulatedVolumesForUser(userId);
455
456 userid_t sharedStorageUserId = VolumeManager::Instance()->getSharedStorageUser(userId);
457 if (sharedStorageUserId != USER_UNKNOWN) {
458 std::list<std::string> public_vols;
459 listVolumes(VolumeBase::Type::kPublic, public_vols);
460 for (const std::string& id : public_vols) {
461 PublicVolume *pvol = static_cast<PublicVolume *>(findVolume(id).get());
462 if (pvol->getState() != VolumeBase::State::kMounted) {
463 continue;
464 }
465 if (pvol->isVisible() == 0) {
466 continue;
467 }
468 userid_t mountUserId = pvol->getMountUserId();
469 if (userId == mountUserId) {
470 // No need to bind mount for the user that owns the mount
471 continue;
472 }
473
474 if (mountUserId != sharedStorageUserId) {
475 // No need to bind if the user does not share storage with the mount owner
476 continue;
477 }
478 // Create mount directory for the user as there is a chance that no other Volume is
479 // mounted for the user (ex: if the user is just started),
480 // so /mnt/user/user_id does not exist yet.
481 auto mountDirStatus = android::vold::PrepareMountDirForUser(userId);
482 if (mountDirStatus != OK) {
483 LOG(ERROR) << "Failed to create Mount Directory for user " << userId;
484 }
485 auto bindMountStatus = pvol->bindMountForUser(userId);
486 if (bindMountStatus != OK) {
487 LOG(ERROR) << "Bind Mounting Public Volume: " << pvol << " for user: " << userId
488 << "Failed. Error: " << bindMountStatus;
489 }
490 }
491 }
492 }
493
494 mStartedUsers.insert(userId);
495
496 createPendingDisksIfNeeded();
497 return 0;
498 }
499
onUserStopped(userid_t userId)500 int VolumeManager::onUserStopped(userid_t userId) {
501 LOG(VERBOSE) << "onUserStopped: " << userId;
502
503 if (mStartedUsers.find(userId) != mStartedUsers.end()) {
504 destroyEmulatedVolumesForUser(userId);
505
506 userid_t sharedStorageUserId = VolumeManager::Instance()->getSharedStorageUser(userId);
507 if (sharedStorageUserId != USER_UNKNOWN) {
508 std::list<std::string> public_vols;
509 listVolumes(VolumeBase::Type::kPublic, public_vols);
510 for (const std::string &id: public_vols) {
511 PublicVolume *pvol = static_cast<PublicVolume *>(findVolume(id).get());
512 if (pvol->getState() != VolumeBase::State::kMounted) {
513 continue;
514 }
515 if (pvol->isVisible() == 0) {
516 continue;
517 }
518 userid_t mountUserId = pvol->getMountUserId();
519 if (userId == mountUserId) {
520 // No need to remove bind mount for the user that owns the mount
521 continue;
522 }
523 if (mountUserId != sharedStorageUserId) {
524 // No need to remove bind mount
525 // if the user does not share storage with the mount owner
526 continue;
527 }
528 LOG(INFO) << "Removing Public Volume Bind Mount for: " << userId;
529 auto mountPath = GetFuseMountPathForUser(userId, pvol->getStableName());
530 android::vold::ForceUnmount(mountPath);
531 rmdir(mountPath.c_str());
532 }
533 }
534
535 }
536
537 mStartedUsers.erase(userId);
538 return 0;
539 }
540
createPendingDisksIfNeeded()541 void VolumeManager::createPendingDisksIfNeeded() {
542 bool userZeroStarted = mStartedUsers.find(0) != mStartedUsers.end();
543 if (!mSecureKeyguardShowing && userZeroStarted) {
544 // Now that secure keyguard has been dismissed and user 0 has
545 // started, process any pending disks
546 for (const auto& disk : mPendingDisks) {
547 disk->create();
548 mDisks.push_back(disk);
549 }
550 mPendingDisks.clear();
551 }
552 }
553
onSecureKeyguardStateChanged(bool isShowing)554 int VolumeManager::onSecureKeyguardStateChanged(bool isShowing) {
555 mSecureKeyguardShowing = isShowing;
556 createPendingDisksIfNeeded();
557 return 0;
558 }
559
560 // This code is executed after a fork so it's very important that the set of
561 // methods we call here is strictly limited.
562 //
563 // TODO: Get rid of this guesswork altogether and instead exec a process
564 // immediately after fork to do our bindding for us.
childProcess(const char * storageSource,const char * userSource,int nsFd,const char * name)565 static bool childProcess(const char* storageSource, const char* userSource, int nsFd,
566 const char* name) {
567 if (setns(nsFd, CLONE_NEWNS) != 0) {
568 async_safe_format_log(ANDROID_LOG_ERROR, "vold", "Failed to setns for %s :%s", name,
569 strerror(errno));
570 return false;
571 }
572
573 // NOTE: Inlined from vold::UnmountTree here to avoid using PLOG methods and
574 // to also protect against future changes that may cause issues across a
575 // fork.
576 if (TEMP_FAILURE_RETRY(umount2("/storage/", MNT_DETACH)) < 0 && errno != EINVAL &&
577 errno != ENOENT) {
578 async_safe_format_log(ANDROID_LOG_ERROR, "vold", "Failed to unmount /storage/ :%s",
579 strerror(errno));
580 return false;
581 }
582
583 if (TEMP_FAILURE_RETRY(mount(storageSource, "/storage", NULL, MS_BIND | MS_REC, NULL)) == -1) {
584 async_safe_format_log(ANDROID_LOG_ERROR, "vold", "Failed to mount %s for %s :%s",
585 storageSource, name, strerror(errno));
586 return false;
587 }
588
589 if (TEMP_FAILURE_RETRY(mount(NULL, "/storage", NULL, MS_REC | MS_SLAVE, NULL)) == -1) {
590 async_safe_format_log(ANDROID_LOG_ERROR, "vold",
591 "Failed to set MS_SLAVE to /storage for %s :%s", name,
592 strerror(errno));
593 return false;
594 }
595
596 if (TEMP_FAILURE_RETRY(mount(userSource, "/storage/self", NULL, MS_BIND, NULL)) == -1) {
597 async_safe_format_log(ANDROID_LOG_ERROR, "vold", "Failed to mount %s for %s :%s",
598 userSource, name, strerror(errno));
599 return false;
600 }
601
602 return true;
603 }
604
605 // Fork the process and remount storage
forkAndRemountChild(uid_t uid,pid_t pid,int nsFd,const char * name,void * params)606 bool forkAndRemountChild(uid_t uid, pid_t pid, int nsFd, const char* name, void* params) {
607 int32_t mountMode = *static_cast<int32_t*>(params);
608 std::string userSource;
609 std::string storageSource;
610 pid_t child;
611 // Need to fix these paths to account for when sdcardfs is gone
612 switch (mountMode) {
613 case VoldNativeService::REMOUNT_MODE_NONE:
614 return true;
615 case VoldNativeService::REMOUNT_MODE_DEFAULT:
616 storageSource = "/mnt/runtime/default";
617 break;
618 case VoldNativeService::REMOUNT_MODE_ANDROID_WRITABLE:
619 case VoldNativeService::REMOUNT_MODE_INSTALLER:
620 storageSource = "/mnt/runtime/write";
621 break;
622 case VoldNativeService::REMOUNT_MODE_PASS_THROUGH:
623 return true;
624 default:
625 PLOG(ERROR) << "Unknown mode " << std::to_string(mountMode);
626 return false;
627 }
628 LOG(DEBUG) << "Remounting " << uid << " as " << storageSource;
629
630 // Fork a child to mount user-specific symlink helper into place
631 userSource = StringPrintf("/mnt/user/%d", multiuser_get_user_id(uid));
632 if (!(child = fork())) {
633 if (childProcess(storageSource.c_str(), userSource.c_str(), nsFd, name)) {
634 _exit(0);
635 } else {
636 _exit(1);
637 }
638 }
639
640 if (child == -1) {
641 PLOG(ERROR) << "Failed to fork";
642 return false;
643 } else {
644 TEMP_FAILURE_RETRY(waitpid(child, nullptr, 0));
645 }
646 return true;
647 }
648
649 // Helper function to scan all processes in /proc and call the callback if:
650 // 1). pid belongs to an app process
651 // 2). If input uid is 0 or it matches the process uid
652 // 3). If userId is not -1 or userId matches the process userId
scanProcProcesses(uid_t uid,userid_t userId,ScanProcCallback callback,void * params)653 bool scanProcProcesses(uid_t uid, userid_t userId, ScanProcCallback callback, void* params) {
654 DIR* dir;
655 struct dirent* de;
656 std::string rootName;
657 std::string pidName;
658 std::string exeName;
659 int pidFd;
660 int nsFd;
661 struct stat sb;
662
663 if (!(dir = opendir("/proc"))) {
664 async_safe_format_log(ANDROID_LOG_ERROR, "vold", "Failed to opendir");
665 return false;
666 }
667
668 // Figure out root namespace to compare against below
669 if (!android::vold::Readlinkat(dirfd(dir), "1/ns/mnt", &rootName)) {
670 async_safe_format_log(ANDROID_LOG_ERROR, "vold", "Failed to read root namespace");
671 closedir(dir);
672 return false;
673 }
674
675 async_safe_format_log(ANDROID_LOG_INFO, "vold", "Start scanning all processes");
676 // Poke through all running PIDs look for apps running as UID
677 while ((de = readdir(dir))) {
678 pid_t pid;
679 if (de->d_type != DT_DIR) continue;
680 if (!android::base::ParseInt(de->d_name, &pid)) continue;
681
682 pidFd = -1;
683 nsFd = -1;
684
685 pidFd = openat(dirfd(dir), de->d_name, O_RDONLY | O_DIRECTORY | O_CLOEXEC);
686 if (pidFd < 0) {
687 goto next;
688 }
689 if (fstat(pidFd, &sb) != 0) {
690 async_safe_format_log(ANDROID_LOG_ERROR, "vold", "Failed to stat %s", de->d_name);
691 goto next;
692 }
693 if (uid != 0 && sb.st_uid != uid) {
694 goto next;
695 }
696 if (userId != static_cast<userid_t>(-1) && multiuser_get_user_id(sb.st_uid) != userId) {
697 goto next;
698 }
699
700 // Matches so far, but refuse to touch if in root namespace
701 if (!android::vold::Readlinkat(pidFd, "ns/mnt", &pidName)) {
702 async_safe_format_log(ANDROID_LOG_ERROR, "vold",
703 "Failed to read namespacefor %s", de->d_name);
704 goto next;
705 }
706 if (rootName == pidName) {
707 goto next;
708 }
709
710 // Some early native processes have mount namespaces that are different
711 // from that of the init. Therefore, above check can't filter them out.
712 // Since the propagation type of / is 'shared', unmounting /storage
713 // for the early native processes affects other processes including
714 // init. Filter out such processes by skipping if a process is a
715 // non-Java process whose UID is < AID_APP_START. (The UID condition
716 // is required to not filter out child processes spawned by apps.)
717 if (!android::vold::Readlinkat(pidFd, "exe", &exeName)) {
718 goto next;
719 }
720 if (!StartsWith(exeName, "/system/bin/app_process") && sb.st_uid < AID_APP_START) {
721 goto next;
722 }
723
724 // We purposefully leave the namespace open across the fork
725 // NOLINTNEXTLINE(android-cloexec-open): Deliberately not O_CLOEXEC
726 nsFd = openat(pidFd, "ns/mnt", O_RDONLY);
727 if (nsFd < 0) {
728 async_safe_format_log(ANDROID_LOG_ERROR, "vold",
729 "Failed to open namespace for %s", de->d_name);
730 goto next;
731 }
732
733 if (!callback(sb.st_uid, pid, nsFd, de->d_name, params)) {
734 async_safe_format_log(ANDROID_LOG_ERROR, "vold", "Failed in callback");
735 }
736
737 next:
738 close(nsFd);
739 close(pidFd);
740 }
741 closedir(dir);
742 async_safe_format_log(ANDROID_LOG_INFO, "vold", "Finished scanning all processes");
743 return true;
744 }
745
746 // In each app's namespace, unmount obb and data dirs
umountStorageDirs(int nsFd,const char * android_data_dir,const char * android_obb_dir,int uid,const char * targets[],int size)747 static bool umountStorageDirs(int nsFd, const char* android_data_dir, const char* android_obb_dir,
748 int uid, const char* targets[], int size) {
749 // This code is executed after a fork so it's very important that the set of
750 // methods we call here is strictly limited.
751 if (setns(nsFd, CLONE_NEWNS) != 0) {
752 async_safe_format_log(ANDROID_LOG_ERROR, "vold", "Failed to setns %s", strerror(errno));
753 return false;
754 }
755
756 // Unmount of Android/data/foo needs to be done before Android/data below.
757 bool result = true;
758 for (int i = 0; i < size; i++) {
759 if (TEMP_FAILURE_RETRY(umount2(targets[i], MNT_DETACH)) < 0 && errno != EINVAL &&
760 errno != ENOENT) {
761 async_safe_format_log(ANDROID_LOG_ERROR, "vold", "Failed to umount %s: %s",
762 targets[i], strerror(errno));
763 result = false;
764 }
765 }
766
767 // Mount tmpfs on Android/data and Android/obb
768 if (TEMP_FAILURE_RETRY(umount2(android_data_dir, MNT_DETACH)) < 0 && errno != EINVAL &&
769 errno != ENOENT) {
770 async_safe_format_log(ANDROID_LOG_ERROR, "vold", "Failed to umount %s :%s",
771 android_data_dir, strerror(errno));
772 result = false;
773 }
774 if (TEMP_FAILURE_RETRY(umount2(android_obb_dir, MNT_DETACH)) < 0 && errno != EINVAL &&
775 errno != ENOENT) {
776 async_safe_format_log(ANDROID_LOG_ERROR, "vold", "Failed to umount %s :%s",
777 android_obb_dir, strerror(errno));
778 result = false;
779 }
780 return result;
781 }
782
783 // In each app's namespace, mount tmpfs on obb and data dir, and bind mount obb and data
784 // package dirs.
remountStorageDirs(int nsFd,const char * android_data_dir,const char * android_obb_dir,int uid,const char * sources[],const char * targets[],int size)785 static bool remountStorageDirs(int nsFd, const char* android_data_dir, const char* android_obb_dir,
786 int uid, const char* sources[], const char* targets[], int size) {
787 // This code is executed after a fork so it's very important that the set of
788 // methods we call here is strictly limited.
789 if (setns(nsFd, CLONE_NEWNS) != 0) {
790 async_safe_format_log(ANDROID_LOG_ERROR, "vold", "Failed to setns %s", strerror(errno));
791 return false;
792 }
793
794 // Mount tmpfs on Android/data and Android/obb
795 if (TEMP_FAILURE_RETRY(mount("tmpfs", android_data_dir, "tmpfs",
796 MS_NOSUID | MS_NODEV | MS_NOEXEC, "uid=0,gid=0,mode=0751")) == -1) {
797 async_safe_format_log(ANDROID_LOG_ERROR, "vold", "Failed to mount tmpfs to %s :%s",
798 android_data_dir, strerror(errno));
799 return false;
800 }
801 if (TEMP_FAILURE_RETRY(mount("tmpfs", android_obb_dir, "tmpfs",
802 MS_NOSUID | MS_NODEV | MS_NOEXEC, "uid=0,gid=0,mode=0751")) == -1) {
803 async_safe_format_log(ANDROID_LOG_ERROR, "vold", "Failed to mount tmpfs to %s :%s",
804 android_obb_dir, strerror(errno));
805 return false;
806 }
807
808 for (int i = 0; i < size; i++) {
809 // Create package dir and bind mount it to the actual one.
810 if (TEMP_FAILURE_RETRY(mkdir(targets[i], 0700)) == -1) {
811 async_safe_format_log(ANDROID_LOG_ERROR, "vold", "Failed to mkdir %s %s",
812 targets[i], strerror(errno));
813 return false;
814 }
815 if (TEMP_FAILURE_RETRY(mount(sources[i], targets[i], NULL, MS_BIND | MS_REC, NULL)) == -1) {
816 async_safe_format_log(ANDROID_LOG_ERROR, "vold", "Failed to mount %s to %s :%s",
817 sources[i], targets[i], strerror(errno));
818 return false;
819 }
820 }
821 return true;
822 }
823
getStorageDirSrc(userid_t userId,const std::string & dirName,const std::string & packageName)824 static std::string getStorageDirSrc(userid_t userId, const std::string& dirName,
825 const std::string& packageName) {
826 if (IsSdcardfsUsed()) {
827 return StringPrintf("/mnt/runtime/default/emulated/%d/%s/%s",
828 userId, dirName.c_str(), packageName.c_str());
829 } else {
830 return StringPrintf("/mnt/pass_through/%d/emulated/%d/%s/%s",
831 userId, userId, dirName.c_str(), packageName.c_str());
832 }
833 }
834
getStorageDirTarget(userid_t userId,std::string dirName,std::string packageName)835 static std::string getStorageDirTarget(userid_t userId, std::string dirName,
836 std::string packageName) {
837 return StringPrintf("/storage/emulated/%d/%s/%s",
838 userId, dirName.c_str(), packageName.c_str());
839 }
840
841 // Fork the process and remount / unmount app data and obb dirs
forkAndRemountStorage(int uid,int pid,bool doUnmount,const std::vector<std::string> & packageNames)842 bool VolumeManager::forkAndRemountStorage(int uid, int pid, bool doUnmount,
843 const std::vector<std::string>& packageNames) {
844 userid_t userId = multiuser_get_user_id(uid);
845 std::string mnt_path = StringPrintf("/proc/%d/ns/mnt", pid);
846 android::base::unique_fd nsFd(
847 TEMP_FAILURE_RETRY(open(mnt_path.c_str(), O_RDONLY | O_CLOEXEC)));
848 if (nsFd == -1) {
849 PLOG(ERROR) << "Unable to open " << mnt_path.c_str();
850 return false;
851 }
852 // Storing both Android/obb and Android/data paths.
853 int size = packageNames.size() * 2;
854
855 std::unique_ptr<std::string[]> sources(new std::string[size]);
856 std::unique_ptr<std::string[]> targets(new std::string[size]);
857 std::unique_ptr<const char*[]> sources_uptr(new const char*[size]);
858 std::unique_ptr<const char*[]> targets_uptr(new const char*[size]);
859 const char** sources_cstr = sources_uptr.get();
860 const char** targets_cstr = targets_uptr.get();
861
862 for (int i = 0; i < size; i += 2) {
863 std::string const& packageName = packageNames[i/2];
864 sources[i] = getStorageDirSrc(userId, "Android/data", packageName);
865 targets[i] = getStorageDirTarget(userId, "Android/data", packageName);
866 sources[i+1] = getStorageDirSrc(userId, "Android/obb", packageName);
867 targets[i+1] = getStorageDirTarget(userId, "Android/obb", packageName);
868
869 sources_cstr[i] = sources[i].c_str();
870 targets_cstr[i] = targets[i].c_str();
871 sources_cstr[i+1] = sources[i+1].c_str();
872 targets_cstr[i+1] = targets[i+1].c_str();
873 }
874
875 for (int i = 0; i < size; i++) {
876 // Make sure /storage/emulated/... paths are setup correctly
877 // This needs to be done before EnsureDirExists to ensure Android/ is created.
878 auto status = setupAppDir(targets_cstr[i], uid, false /* fixupExistingOnly */);
879 if (status != OK) {
880 PLOG(ERROR) << "Failed to create dir: " << targets_cstr[i];
881 return false;
882 }
883 status = EnsureDirExists(sources_cstr[i], 0771, AID_MEDIA_RW, AID_MEDIA_RW);
884 if (status != OK) {
885 PLOG(ERROR) << "Failed to create dir: " << sources_cstr[i];
886 return false;
887 }
888 }
889
890 char android_data_dir[PATH_MAX];
891 char android_obb_dir[PATH_MAX];
892 snprintf(android_data_dir, PATH_MAX, "/storage/emulated/%d/Android/data", userId);
893 snprintf(android_obb_dir, PATH_MAX, "/storage/emulated/%d/Android/obb", userId);
894
895 pid_t child;
896 // Fork a child to mount Android/obb android Android/data dirs, as we don't want it to affect
897 // original vold process mount namespace.
898 if (!(child = fork())) {
899 if (doUnmount) {
900 if (umountStorageDirs(nsFd, android_data_dir, android_obb_dir, uid,
901 targets_cstr, size)) {
902 _exit(0);
903 } else {
904 _exit(1);
905 }
906 } else {
907 if (remountStorageDirs(nsFd, android_data_dir, android_obb_dir, uid,
908 sources_cstr, targets_cstr, size)) {
909 _exit(0);
910 } else {
911 _exit(1);
912 }
913 }
914 }
915
916 if (child == -1) {
917 PLOG(ERROR) << "Failed to fork";
918 return false;
919 } else {
920 int status;
921 if (TEMP_FAILURE_RETRY(waitpid(child, &status, 0)) == -1) {
922 PLOG(ERROR) << "Failed to waitpid: " << child;
923 return false;
924 }
925 if (!WIFEXITED(status)) {
926 PLOG(ERROR) << "Process did not exit normally, status: " << status;
927 return false;
928 }
929 if (WEXITSTATUS(status)) {
930 PLOG(ERROR) << "Process exited with code: " << WEXITSTATUS(status);
931 return false;
932 }
933 }
934 return true;
935 }
936
handleAppStorageDirs(int uid,int pid,bool doUnmount,const std::vector<std::string> & packageNames)937 int VolumeManager::handleAppStorageDirs(int uid, int pid,
938 bool doUnmount, const std::vector<std::string>& packageNames) {
939 // Only run the remount if fuse is mounted for that user.
940 userid_t userId = multiuser_get_user_id(uid);
941 bool fuseMounted = false;
942 for (auto& vol : mInternalEmulatedVolumes) {
943 if (vol->getMountUserId() == userId && vol->getState() == VolumeBase::State::kMounted) {
944 auto* emulatedVol = static_cast<android::vold::EmulatedVolume*>(vol.get());
945 if (emulatedVol) {
946 fuseMounted = emulatedVol->isFuseMounted();
947 }
948 break;
949 }
950 }
951 if (fuseMounted) {
952 forkAndRemountStorage(uid, pid, doUnmount, packageNames);
953 }
954 return 0;
955 }
956
abortFuse()957 int VolumeManager::abortFuse() {
958 return android::vold::AbortFuseConnections();
959 }
960
reset()961 int VolumeManager::reset() {
962 // Tear down all existing disks/volumes and start from a blank slate so
963 // newly connected framework hears all events.
964
965 // Destroy StubVolume disks. This needs to be done before destroying
966 // EmulatedVolumes because in ARC (Android on ChromeOS), ChromeOS Downloads
967 // directory (which is in a StubVolume) is bind-mounted to
968 // /data/media/0/Download.
969 // We do not recreate StubVolumes here because they are managed from outside
970 // Android (e.g. from ChromeOS) and their disk recreation on reset events
971 // should be handled from outside by calling createStubVolume() again.
972 for (const auto& disk : mDisks) {
973 if (disk->isStub()) {
974 disk->destroy();
975 }
976 }
977 // Remove StubVolume from both mDisks and mPendingDisks.
978 const auto isStub = [](const auto& disk) { return disk->isStub(); };
979 mDisks.remove_if(isStub);
980 mPendingDisks.remove_if(isStub);
981
982 for (const auto& vol : mInternalEmulatedVolumes) {
983 vol->destroy();
984 }
985 mInternalEmulatedVolumes.clear();
986
987 // Destroy and recreate non-StubVolume disks.
988 for (const auto& disk : mDisks) {
989 disk->destroy();
990 disk->create();
991 }
992
993 updateVirtualDisk();
994 mAddedUsers.clear();
995 mStartedUsers.clear();
996 mSharedStorageUser.clear();
997
998 // Abort all FUSE connections to avoid deadlocks if the FUSE daemon was killed
999 // with FUSE fds open.
1000 abortFuse();
1001 return 0;
1002 }
1003
1004 // Can be called twice (sequentially) during shutdown. should be safe for that.
shutdown()1005 int VolumeManager::shutdown() {
1006 if (mInternalEmulatedVolumes.empty()) {
1007 return 0; // already shutdown
1008 }
1009 android::vold::sSleepOnUnmount = false;
1010 // Destroy StubVolume disks before destroying EmulatedVolumes (see the
1011 // comment in VolumeManager::reset()).
1012 for (const auto& disk : mDisks) {
1013 if (disk->isStub()) {
1014 disk->destroy();
1015 }
1016 }
1017 for (const auto& vol : mInternalEmulatedVolumes) {
1018 vol->destroy();
1019 }
1020 for (const auto& disk : mDisks) {
1021 if (!disk->isStub()) {
1022 disk->destroy();
1023 }
1024 }
1025
1026 mInternalEmulatedVolumes.clear();
1027 mDisks.clear();
1028 mPendingDisks.clear();
1029 android::vold::sSleepOnUnmount = true;
1030
1031 return 0;
1032 }
1033
unmountAll()1034 int VolumeManager::unmountAll() {
1035 std::lock_guard<std::mutex> lock(mLock);
1036 ATRACE_NAME("VolumeManager::unmountAll()");
1037
1038 // First, try gracefully unmounting all known devices
1039 // Unmount StubVolume disks before unmounting EmulatedVolumes (see the
1040 // comment in VolumeManager::reset()).
1041 for (const auto& disk : mDisks) {
1042 if (disk->isStub()) {
1043 disk->unmountAll();
1044 }
1045 }
1046 for (const auto& vol : mInternalEmulatedVolumes) {
1047 vol->unmount();
1048 }
1049 for (const auto& disk : mDisks) {
1050 if (!disk->isStub()) {
1051 disk->unmountAll();
1052 }
1053 }
1054
1055 // Worst case we might have some stale mounts lurking around, so
1056 // force unmount those just to be safe.
1057 FILE* fp = setmntent("/proc/mounts", "re");
1058 if (fp == NULL) {
1059 PLOG(ERROR) << "Failed to open /proc/mounts";
1060 return -errno;
1061 }
1062
1063 // Some volumes can be stacked on each other, so force unmount in
1064 // reverse order to give us the best chance of success.
1065 std::list<std::string> toUnmount;
1066 mntent* mentry;
1067 while ((mentry = getmntent(fp)) != NULL) {
1068 auto test = std::string(mentry->mnt_dir);
1069 if ((StartsWith(test, "/mnt/") &&
1070 #ifdef __ANDROID_DEBUGGABLE__
1071 !StartsWith(test, "/mnt/scratch") &&
1072 #endif
1073 !StartsWith(test, "/mnt/vendor") && !StartsWith(test, "/mnt/product") &&
1074 !StartsWith(test, "/mnt/installer") && !StartsWith(test, "/mnt/androidwritable") &&
1075 !StartsWith(test, "/mnt/vm")) ||
1076 StartsWith(test, "/storage/")) {
1077 toUnmount.push_front(test);
1078 }
1079 }
1080 endmntent(fp);
1081
1082 for (const auto& path : toUnmount) {
1083 LOG(DEBUG) << "Tearing down stale mount " << path;
1084 android::vold::ForceUnmount(path);
1085 }
1086
1087 return 0;
1088 }
1089
ensureAppDirsCreated(const std::vector<std::string> & paths,int32_t appUid)1090 int VolumeManager::ensureAppDirsCreated(const std::vector<std::string>& paths, int32_t appUid) {
1091 int size = paths.size();
1092 for (int i = 0; i < size; i++) {
1093 int result = setupAppDir(paths[i], appUid, false /* fixupExistingOnly */,
1094 true /* skipIfDirExists */);
1095 if (result != OK) {
1096 return result;
1097 }
1098 }
1099 return OK;
1100 }
1101
setupAppDir(const std::string & path,int32_t appUid,bool fixupExistingOnly,bool skipIfDirExists)1102 int VolumeManager::setupAppDir(const std::string& path, int32_t appUid, bool fixupExistingOnly,
1103 bool skipIfDirExists) {
1104 // Only offer to create directories for paths managed by vold
1105 if (!StartsWith(path, "/storage/")) {
1106 LOG(ERROR) << "Failed to find mounted volume for " << path;
1107 return -EINVAL;
1108 }
1109
1110 // Find the volume it belongs to
1111 auto filter_fn = [&](const VolumeBase& vol) {
1112 if (vol.getState() != VolumeBase::State::kMounted) {
1113 // The volume must be mounted
1114 return false;
1115 }
1116 if (!vol.isVisibleForWrite()) {
1117 // App dirs should only be created for writable volumes.
1118 return false;
1119 }
1120 if (vol.getInternalPath().empty()) {
1121 return false;
1122 }
1123 if (vol.getMountUserId() != USER_UNKNOWN &&
1124 vol.getMountUserId() != multiuser_get_user_id(appUid)) {
1125 // The app dir must be created on a volume with the same user-id
1126 return false;
1127 }
1128 if (!path.empty() && StartsWith(path, vol.getPath())) {
1129 return true;
1130 }
1131
1132 return false;
1133 };
1134 auto volume = findVolumeWithFilter(filter_fn);
1135 if (volume == nullptr) {
1136 LOG(ERROR) << "Failed to find mounted volume for " << path;
1137 return -EINVAL;
1138 }
1139 // Convert paths to lower filesystem paths to avoid making FUSE requests for these reasons:
1140 // 1. A FUSE request from vold puts vold at risk of hanging if the FUSE daemon is down
1141 // 2. The FUSE daemon prevents requests on /mnt/user/0/emulated/<userid != 0> and a request
1142 // on /storage/emulated/10 means /mnt/user/0/emulated/10
1143 const std::string lowerPath =
1144 volume->getInternalPath() + path.substr(volume->getPath().length());
1145
1146 const std::string volumeRoot = volume->getRootPath(); // eg /data/media/0
1147
1148 const int access_result = access(lowerPath.c_str(), F_OK);
1149 if (fixupExistingOnly && access_result != 0) {
1150 // Nothing to fixup
1151 return OK;
1152 }
1153
1154 if (skipIfDirExists && access_result == 0) {
1155 // It's safe to assume it's ok as it will be used for zygote to bind mount dir only,
1156 // which the dir doesn't need to have correct permission for now yet.
1157 return OK;
1158 }
1159
1160 if (volume->getType() == VolumeBase::Type::kPublic) {
1161 // On public volumes, we don't need to setup permissions, as everything goes through
1162 // FUSE; just create the dirs and be done with it.
1163 return fs_mkdirs(lowerPath.c_str(), 0700);
1164 }
1165
1166 // Create the app paths we need from the root
1167 return PrepareAppDirFromRoot(lowerPath, volumeRoot, appUid, fixupExistingOnly);
1168 }
1169
fixupAppDir(const std::string & path,int32_t appUid)1170 int VolumeManager::fixupAppDir(const std::string& path, int32_t appUid) {
1171 if (IsSdcardfsUsed()) {
1172 //sdcardfs magically does this for us
1173 return OK;
1174 }
1175 return setupAppDir(path, appUid, true /* fixupExistingOnly */);
1176 }
1177
createObb(const std::string & sourcePath,int32_t ownerGid,std::string * outVolId)1178 int VolumeManager::createObb(const std::string& sourcePath, int32_t ownerGid,
1179 std::string* outVolId) {
1180 int id = mNextObbId++;
1181
1182 std::string lowerSourcePath;
1183
1184 // Convert to lower filesystem path
1185 if (StartsWith(sourcePath, "/storage/")) {
1186 auto filter_fn = [&](const VolumeBase& vol) {
1187 if (vol.getState() != VolumeBase::State::kMounted) {
1188 // The volume must be mounted
1189 return false;
1190 }
1191 if (!vol.isVisibleForWrite()) {
1192 // Obb volume should only be created for writable volumes.
1193 return false;
1194 }
1195 if (vol.getInternalPath().empty()) {
1196 return false;
1197 }
1198 if (!sourcePath.empty() && StartsWith(sourcePath, vol.getPath())) {
1199 return true;
1200 }
1201
1202 return false;
1203 };
1204 auto volume = findVolumeWithFilter(filter_fn);
1205 if (volume == nullptr) {
1206 LOG(ERROR) << "Failed to find mounted volume for " << sourcePath;
1207 return -EINVAL;
1208 } else {
1209 lowerSourcePath =
1210 volume->getInternalPath() + sourcePath.substr(volume->getPath().length());
1211 }
1212 } else {
1213 lowerSourcePath = sourcePath;
1214 }
1215
1216 auto vol = std::shared_ptr<android::vold::VolumeBase>(
1217 new android::vold::ObbVolume(id, lowerSourcePath, ownerGid));
1218 vol->create();
1219
1220 mObbVolumes.push_back(vol);
1221 *outVolId = vol->getId();
1222 return android::OK;
1223 }
1224
destroyObb(const std::string & volId)1225 int VolumeManager::destroyObb(const std::string& volId) {
1226 auto i = mObbVolumes.begin();
1227 while (i != mObbVolumes.end()) {
1228 if ((*i)->getId() == volId) {
1229 (*i)->destroy();
1230 i = mObbVolumes.erase(i);
1231 } else {
1232 ++i;
1233 }
1234 }
1235 return android::OK;
1236 }
1237
createStubVolume(const std::string & sourcePath,const std::string & mountPath,const std::string & fsType,const std::string & fsUuid,const std::string & fsLabel,int32_t flags,std::string * outVolId)1238 int VolumeManager::createStubVolume(const std::string& sourcePath, const std::string& mountPath,
1239 const std::string& fsType, const std::string& fsUuid,
1240 const std::string& fsLabel, int32_t flags,
1241 std::string* outVolId) {
1242 dev_t stubId = --mNextStubId;
1243 auto vol = std::shared_ptr<android::vold::StubVolume>(
1244 new android::vold::StubVolume(stubId, sourcePath, mountPath, fsType, fsUuid, fsLabel));
1245
1246 int32_t passedFlags = 0;
1247 passedFlags |= (flags & android::vold::Disk::Flags::kUsb);
1248 passedFlags |= (flags & android::vold::Disk::Flags::kSd);
1249 if (flags & android::vold::Disk::Flags::kStubVisible) {
1250 passedFlags |= (flags & android::vold::Disk::Flags::kStubVisible);
1251 } else {
1252 passedFlags |= (flags & android::vold::Disk::Flags::kStubInvisible);
1253 }
1254 // StubDisk doesn't have device node corresponds to it. So, a fake device
1255 // number is used.
1256 auto disk = std::shared_ptr<android::vold::Disk>(
1257 new android::vold::Disk("stub", stubId, "stub", passedFlags));
1258 disk->initializePartition(vol);
1259 handleDiskAdded(disk);
1260 *outVolId = vol->getId();
1261 return android::OK;
1262 }
1263
destroyStubVolume(const std::string & volId)1264 int VolumeManager::destroyStubVolume(const std::string& volId) {
1265 auto tokens = android::base::Split(volId, ":");
1266 CHECK(tokens.size() == 2);
1267 dev_t stubId;
1268 CHECK(android::base::ParseUint(tokens[1], &stubId));
1269 handleDiskRemoved(stubId);
1270 return android::OK;
1271 }
1272
mountAppFuse(uid_t uid,int mountId,unique_fd * device_fd)1273 int VolumeManager::mountAppFuse(uid_t uid, int mountId, unique_fd* device_fd) {
1274 return android::vold::MountAppFuse(uid, mountId, device_fd);
1275 }
1276
unmountAppFuse(uid_t uid,int mountId)1277 int VolumeManager::unmountAppFuse(uid_t uid, int mountId) {
1278 return android::vold::UnmountAppFuse(uid, mountId);
1279 }
1280
openAppFuseFile(uid_t uid,int mountId,int fileId,int flags)1281 int VolumeManager::openAppFuseFile(uid_t uid, int mountId, int fileId, int flags) {
1282 return android::vold::OpenAppFuseFile(uid, mountId, fileId, flags);
1283 }
1284
getDeviceSize(std::string & device,int64_t * storageSize,bool isF2fsPrimary)1285 static android::status_t getDeviceSize(std::string& device, int64_t* storageSize,
1286 bool isF2fsPrimary) {
1287 // Follow any symbolic links
1288 std::string dataDevice;
1289 if (!android::base::Realpath(device, &dataDevice)) {
1290 dataDevice = device;
1291 }
1292
1293 // Handle mapped volumes.
1294 auto& dm = android::dm::DeviceMapper::Instance();
1295 std::string dmPath = dataDevice;
1296 if (dm.IsDmBlockDevice(dataDevice)) {
1297 for (;;) {
1298 auto parent = dm.GetParentBlockDeviceByPath(dataDevice);
1299 if (!parent.has_value()) break;
1300 dataDevice = *parent;
1301 }
1302 } else if (isF2fsPrimary) {
1303 if (!dm.GetDmDevicePathByName(android::base::Basename(device), &dmPath)) {
1304 LOG(WARNING) << "No proper dm device for " << device;
1305 isF2fsPrimary = false;
1306 }
1307 }
1308
1309 // Find a device name for F2FS primary partition
1310 std::string f2fsReservedBlocksSysfs;
1311 std::size_t leaf;
1312 if (isF2fsPrimary) {
1313 leaf = dmPath.rfind('/');
1314 if (leaf == std::string::npos) {
1315 LOG(WARNING) << "dm device " << dmPath << " is not a path";
1316 isF2fsPrimary = false;
1317 }
1318 f2fsReservedBlocksSysfs =
1319 std::string() + "/sys/fs/f2fs/" + dmPath.substr(leaf + 1) + "/reserved_blocks";
1320 }
1321
1322 // Get the potential /sys/block entry
1323 leaf = dataDevice.rfind('/');
1324 if (leaf == std::string::npos) {
1325 LOG(ERROR) << "data device " << dataDevice << " is not a path";
1326 return EINVAL;
1327 }
1328 if (dataDevice.substr(0, leaf) != "/dev/block") {
1329 LOG(ERROR) << "data device " << dataDevice << " is not a block device";
1330 return EINVAL;
1331 }
1332 std::string sysfs = std::string() + "/sys/block/" + dataDevice.substr(leaf + 1);
1333
1334 // Look for a directory in /sys/block containing size where the name is a shortened
1335 // version of the name we now have
1336 // Typically we start with something like /sys/block/sda2, and we want /sys/block/sda
1337 // Note that this directory only contains actual disks, not partitions, so this is
1338 // not going to find anything other than the disks
1339 std::string size;
1340 std::string sizeFile;
1341 for (std::string sysfsDir = sysfs;; sysfsDir = sysfsDir.substr(0, sysfsDir.size() - 1)) {
1342 if (sysfsDir.back() == '/') {
1343 LOG(ERROR) << "Could not find valid block device from " << sysfs;
1344 return EINVAL;
1345 }
1346 sizeFile = sysfsDir + "/size";
1347 if (android::base::ReadFileToString(sizeFile, &size, true)) {
1348 break;
1349 }
1350 }
1351
1352 // Read the size file and be done
1353 int64_t sizeNum;
1354 std::stringstream ssSize(size);
1355 ssSize >> sizeNum;
1356 if (ssSize.fail()) {
1357 LOG(ERROR) << sizeFile << " cannot be read as an integer";
1358 return EINVAL;
1359 }
1360
1361 sizeNum *= 512;
1362 if (isF2fsPrimary) {
1363 int64_t reservedBlocksNum = 0;
1364 if (!android::base::ReadFileToString(f2fsReservedBlocksSysfs, &size, true)) {
1365 LOG(WARNING) << "Could not find valid entry from " << f2fsReservedBlocksSysfs;
1366 } else {
1367 std::stringstream reservedBlocks(size);
1368 reservedBlocks >> reservedBlocksNum;
1369 if (reservedBlocks.fail()) {
1370 LOG(WARNING) << f2fsReservedBlocksSysfs << " cannot be read as an integer";
1371 reservedBlocksNum = 0;
1372 }
1373 }
1374 int64_t blockSize = android::base::GetIntProperty("ro.boot.hardware.cpu.pagesize", 0);
1375 sizeNum -= reservedBlocksNum * blockSize;
1376 }
1377
1378 *storageSize = sizeNum;
1379 return OK;
1380 }
1381
GetStorageSize(int64_t * storageSize)1382 android::status_t android::vold::GetStorageSize(int64_t* storageSize) {
1383 android::status_t status;
1384 // Start with the /data mount point from fs_mgr
1385 auto entry = android::fs_mgr::GetEntryForMountPoint(&fstab_default, DATA_MNT_POINT);
1386 if (entry == nullptr) {
1387 LOG(ERROR) << "No mount point entry for " << DATA_MNT_POINT;
1388 return EINVAL;
1389 }
1390
1391 status = getDeviceSize(entry->blk_device, storageSize, entry->fs_type == "f2fs");
1392 if (status != OK) {
1393 return status;
1394 }
1395
1396 for (auto device : entry->user_devices) {
1397 int64_t deviceStorageSize;
1398 status = getDeviceSize(device, &deviceStorageSize, false);
1399 if (status != OK) {
1400 return status;
1401 }
1402 *storageSize += deviceStorageSize;
1403 }
1404
1405 return OK;
1406 }
1407