Fix multi-user and multi-storage with FUSE
Up until now, the FUSE mount logic has made two assumptions:
1. The primary external volume is an emulated volume on /data/media
2. Only the primary user is running, as user zero
These assumptions are fixed by the following changes
creating an EmulatedVolume per Android user and changing the
VolumeBase id format to append the user to the id, so
s/emulated/emulated-0/. This allows us mount separate volumes per user
Some additional refactorings to re-use/clean up code.
Test: adb shell sm set-virtual-disk and partition disk operations work
even after setting up a work profile
Bug: 135341433
Change-Id: Ifabaa12368e5a591fbcdce4ee71c83ff35fdac6b
diff --git a/VolumeManager.cpp b/VolumeManager.cpp
index b0e0b23..3e7101c 100644
--- a/VolumeManager.cpp
+++ b/VolumeManager.cpp
@@ -31,7 +31,6 @@
#include <sys/wait.h>
#include <unistd.h>
#include <array>
-#include <thread>
#include <linux/kdev_t.h>
@@ -68,6 +67,7 @@
#include "fs/Vfat.h"
#include "model/EmulatedVolume.h"
#include "model/ObbVolume.h"
+#include "model/PrivateVolume.h"
#include "model/StubVolume.h"
using android::OK;
@@ -80,10 +80,12 @@
using android::vold::CreateDir;
using android::vold::DeleteDirContents;
using android::vold::DeleteDirContentsAndDir;
+using android::vold::PrivateVolume;
using android::vold::Symlink;
using android::vold::Unlink;
using android::vold::UnmountTree;
using android::vold::VoldNativeService;
+using android::vold::VolumeBase;
static const char* kPathUserMount = "/mnt/user";
static const char* kPathVirtualDisk = "/data/misc/vold/virtual_disk";
@@ -101,22 +103,6 @@
VolumeManager* VolumeManager::sInstance = NULL;
-static void* symlinkPrimary(void* data) {
- std::unique_ptr<std::pair<std::string, std::string>> linkInfo(
- static_cast<std::pair<std::string, std::string>*>(data));
- std::string* source = &linkInfo->first;
- std::string* target = &linkInfo->second;
-
- fs_prepare_dir(source->c_str(), 0755, AID_ROOT, AID_ROOT);
- fs_prepare_dir(target->c_str(), 0755, AID_ROOT, AID_ROOT);
- *target = *target + "/primary";
-
- // Link source to target
- LOG(DEBUG) << "Linking " << *source << " to " << *target;
- Symlink(*source, *target);
- return nullptr;
-}
-
VolumeManager* VolumeManager::Instance() {
if (!sInstance) sInstance = new VolumeManager();
return sInstance;
@@ -191,10 +177,13 @@
// Assume that we always have an emulated volume on internal
// storage; the framework will decide if it should be mounted.
- CHECK(mInternalEmulated == nullptr);
- mInternalEmulated = std::shared_ptr<android::vold::VolumeBase>(
- new android::vold::EmulatedVolume("/data/media"));
- mInternalEmulated->create();
+ CHECK(mInternalEmulatedVolumes.empty());
+
+ auto vol = std::shared_ptr<android::vold::VolumeBase>(
+ new android::vold::EmulatedVolume("/data/media", 0));
+ vol->setMountUserId(0);
+ vol->create();
+ mInternalEmulatedVolumes.push_back(vol);
// Consider creating a virtual disk
updateVirtualDisk();
@@ -203,9 +192,12 @@
}
int VolumeManager::stop() {
- CHECK(mInternalEmulated != nullptr);
- mInternalEmulated->destroy();
- mInternalEmulated = nullptr;
+ CHECK(!mInternalEmulatedVolumes.empty());
+ for (const auto& vol : mInternalEmulatedVolumes) {
+ vol->destroy();
+ }
+ mInternalEmulatedVolumes.clear();
+
return 0;
}
@@ -327,11 +319,10 @@
}
std::shared_ptr<android::vold::VolumeBase> VolumeManager::findVolume(const std::string& id) {
- // Vold could receive "mount" after "shutdown" command in the extreme case.
- // If this happens, mInternalEmulated will equal nullptr and
- // we need to deal with it in order to avoid null pointer crash.
- if (mInternalEmulated != nullptr && mInternalEmulated->getId() == id) {
- return mInternalEmulated;
+ for (const auto& vol : mInternalEmulatedVolumes) {
+ if (vol->getId() == id) {
+ return vol;
+ }
}
for (const auto& disk : mDisks) {
auto vol = disk->findVolume(id);
@@ -382,61 +373,129 @@
}
int VolumeManager::linkPrimary(userid_t userId) {
- bool isFuse = GetBoolProperty(android::vold::kPropFuseSnapshot, false);
+ if (!GetBoolProperty(android::vold::kPropFuseSnapshot, false)) {
+ std::string source(mPrimary->getPath());
+ if (mPrimary->isEmulated()) {
+ source = StringPrintf("%s/%d", source.c_str(), userId);
+ fs_prepare_dir(source.c_str(), 0755, AID_ROOT, AID_ROOT);
+ }
- if (isFuse) {
- // Here we have to touch /mnt/user/userid>/<volumeid> which was already mounted as part of
- // the boot sequence, requiring waiting till a fuse handler is available. If we do this work
- // in foreground we could hang the caller, i.e. system server, which needs to start the fuse
- // handler. So do it in the background.
- std::string source(
- StringPrintf("/mnt/user/%d/%s/%d", userId, mPrimary->getId().c_str(), userId));
- std::string target(StringPrintf("/mnt/user/%d/self", userId));
-
- auto symlinkInfo = new std::pair<std::string, std::string>(source, target);
- std::thread(symlinkPrimary, symlinkInfo).detach();
- return 0;
+ std::string target(StringPrintf("/mnt/user/%d/primary", userId));
+ LOG(DEBUG) << "Linking " << source << " to " << target;
+ Symlink(source, target);
}
-
- std::string source(mPrimary->getPath());
- if (mPrimary->isEmulated()) {
- source = StringPrintf("%s/%d", source.c_str(), userId);
- fs_prepare_dir(source.c_str(), 0755, AID_ROOT, AID_ROOT);
- }
-
- std::string target(StringPrintf("/mnt/user/%d/primary", userId));
- LOG(DEBUG) << "Linking " << source << " to " << target;
- Symlink(source, target);
return 0;
}
+void VolumeManager::destroyEmulatedVolumesForUser(userid_t userId) {
+ // Destroy and remove all unstacked EmulatedVolumes for the user
+ auto i = mInternalEmulatedVolumes.begin();
+ while (i != mInternalEmulatedVolumes.end()) {
+ auto vol = *i;
+ if (vol->getMountUserId() == userId) {
+ vol->destroy();
+ i = mInternalEmulatedVolumes.erase(i);
+ } else {
+ i++;
+ }
+ }
+
+ // Destroy and remove all stacked EmulatedVolumes for the user on each mounted private volume
+ std::list<std::string> private_vols;
+ listVolumes(VolumeBase::Type::kPrivate, private_vols);
+ for (const std::string& id : private_vols) {
+ PrivateVolume* pvol = static_cast<PrivateVolume*>(findVolume(id).get());
+ std::list<std::shared_ptr<VolumeBase>> vols_to_remove;
+ if (pvol->getState() == VolumeBase::State::kMounted) {
+ for (const auto& vol : pvol->getVolumes()) {
+ if (vol->getMountUserId() == userId) {
+ vols_to_remove.push_back(vol);
+ }
+ }
+ for (const auto& vol : vols_to_remove) {
+ vol->destroy();
+ pvol->removeVolume(vol);
+ }
+ } // else EmulatedVolumes will be destroyed on VolumeBase#unmount
+ }
+}
+
+void VolumeManager::createEmulatedVolumesForUser(userid_t userId) {
+ // Create unstacked EmulatedVolumes for the user
+ auto vol = std::shared_ptr<android::vold::VolumeBase>(
+ new android::vold::EmulatedVolume("/data/media", userId));
+ vol->setMountUserId(userId);
+ mInternalEmulatedVolumes.push_back(vol);
+ vol->create();
+
+ // Create stacked EmulatedVolumes for the user on each PrivateVolume
+ std::list<std::string> private_vols;
+ listVolumes(VolumeBase::Type::kPrivate, private_vols);
+ for (const std::string& id : private_vols) {
+ PrivateVolume* pvol = static_cast<PrivateVolume*>(findVolume(id).get());
+ if (pvol->getState() == VolumeBase::State::kMounted) {
+ auto evol =
+ std::shared_ptr<android::vold::VolumeBase>(new android::vold::EmulatedVolume(
+ pvol->getPath() + "/media", pvol->getRawDevice(), pvol->getFsUuid(),
+ userId));
+ evol->setMountUserId(userId);
+ pvol->addVolume(evol);
+ evol->create();
+ } // else EmulatedVolumes will be created per user when on PrivateVolume#doMount
+ }
+}
+
int VolumeManager::onUserAdded(userid_t userId, int userSerialNumber) {
+ LOG(INFO) << "onUserAdded: " << userId;
+
mAddedUsers[userId] = userSerialNumber;
return 0;
}
int VolumeManager::onUserRemoved(userid_t userId) {
+ LOG(INFO) << "onUserRemoved: " << userId;
+
+ if (GetBoolProperty(android::vold::kPropFuseSnapshot, false) &&
+ mAddedUsers.find(userId) != mAddedUsers.end()) {
+ destroyEmulatedVolumesForUser(userId);
+ }
+
mAddedUsers.erase(userId);
+ mStartedUsers.erase(userId);
return 0;
}
int VolumeManager::onUserStarted(userid_t userId) {
- LOG(VERBOSE) << "onUserStarted: " << userId;
- // Note that sometimes the system will spin up processes from Zygote
- // before actually starting the user, so we're okay if Zygote
- // already created this directory.
- std::string path(StringPrintf("%s/%d", kPathUserMount, userId));
- fs_prepare_dir(path.c_str(), 0755, AID_ROOT, AID_ROOT);
+ LOG(INFO) << "onUserStarted: " << userId;
+
+ if (GetBoolProperty(android::vold::kPropFuseSnapshot, false)) {
+ if (mStartedUsers.find(userId) == mStartedUsers.end()) {
+ createEmulatedVolumesForUser(userId);
+ }
+ } else {
+ // Note that sometimes the system will spin up processes from Zygote
+ // before actually starting the user, so we're okay if Zygote
+ // already created this directory.
+ std::string path(StringPrintf("%s/%d", kPathUserMount, userId));
+ fs_prepare_dir(path.c_str(), 0755, AID_ROOT, AID_ROOT);
+
+ if (mPrimary) {
+ linkPrimary(userId);
+ }
+ }
mStartedUsers.insert(userId);
- if (mPrimary) {
- linkPrimary(userId);
- }
return 0;
}
int VolumeManager::onUserStopped(userid_t userId) {
LOG(VERBOSE) << "onUserStopped: " << userId;
+
+ if (GetBoolProperty(android::vold::kPropFuseSnapshot, false) &&
+ mStartedUsers.find(userId) != mStartedUsers.end()) {
+ destroyEmulatedVolumesForUser(userId);
+ }
+
mStartedUsers.erase(userId);
return 0;
}
@@ -640,10 +699,17 @@
int VolumeManager::reset() {
// Tear down all existing disks/volumes and start from a blank slate so
// newly connected framework hears all events.
- if (mInternalEmulated != nullptr) {
- mInternalEmulated->destroy();
- mInternalEmulated->create();
+ for (const auto& vol : mInternalEmulatedVolumes) {
+ vol->destroy();
}
+ mInternalEmulatedVolumes.clear();
+ // Add user 0 cos it's always running and started
+ auto vol = std::shared_ptr<android::vold::VolumeBase>(
+ new android::vold::EmulatedVolume("/data/media", 0));
+ vol->setMountUserId(0);
+ vol->create();
+ mInternalEmulatedVolumes.push_back(vol);
+
for (const auto& disk : mDisks) {
disk->destroy();
disk->create();
@@ -651,20 +717,25 @@
updateVirtualDisk();
mAddedUsers.clear();
mStartedUsers.clear();
+
+ mStartedUsers.insert(0);
return 0;
}
// Can be called twice (sequentially) during shutdown. should be safe for that.
int VolumeManager::shutdown() {
- if (mInternalEmulated == nullptr) {
+ if (mInternalEmulatedVolumes.empty()) {
return 0; // already shutdown
}
android::vold::sSleepOnUnmount = false;
- mInternalEmulated->destroy();
- mInternalEmulated = nullptr;
+ for (const auto& vol : mInternalEmulatedVolumes) {
+ vol->destroy();
+ }
for (const auto& disk : mDisks) {
disk->destroy();
}
+
+ mInternalEmulatedVolumes.clear();
mStubVolumes.clear();
mDisks.clear();
mPendingDisks.clear();
@@ -677,8 +748,8 @@
ATRACE_NAME("VolumeManager::unmountAll()");
// First, try gracefully unmounting all known devices
- if (mInternalEmulated != nullptr) {
- mInternalEmulated->unmount();
+ for (const auto& vol : mInternalEmulatedVolumes) {
+ vol->unmount();
}
for (const auto& stub : mStubVolumes) {
stub->unmount();