Merge "Support bind mounting volumes into other volume's mountpoint." am: 35eb1ae88a
Original change: https://android-review.googlesource.com/c/platform/system/vold/+/2189643
Change-Id: I3e0528ff7a114971a8b6da9cc939c3de0de9fd4f
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>
diff --git a/VoldNativeService.cpp b/VoldNativeService.cpp
index ea2c98c..601323f 100644
--- a/VoldNativeService.cpp
+++ b/VoldNativeService.cpp
@@ -182,11 +182,13 @@
return translate(VolumeManager::Instance()->abortFuse());
}
-binder::Status VoldNativeService::onUserAdded(int32_t userId, int32_t userSerial) {
+binder::Status VoldNativeService::onUserAdded(int32_t userId, int32_t userSerial,
+ int32_t sharesStorageWithUserId) {
ENFORCE_SYSTEM_OR_ROOT;
ACQUIRE_LOCK;
- return translate(VolumeManager::Instance()->onUserAdded(userId, userSerial));
+ return translate(
+ VolumeManager::Instance()->onUserAdded(userId, userSerial, sharesStorageWithUserId));
}
binder::Status VoldNativeService::onUserRemoved(int32_t userId) {
diff --git a/VoldNativeService.h b/VoldNativeService.h
index 37a988b..12a93f5 100644
--- a/VoldNativeService.h
+++ b/VoldNativeService.h
@@ -38,7 +38,7 @@
binder::Status shutdown();
binder::Status abortFuse();
- binder::Status onUserAdded(int32_t userId, int32_t userSerial);
+ binder::Status onUserAdded(int32_t userId, int32_t userSerial, int32_t sharesStorageWithUserId);
binder::Status onUserRemoved(int32_t userId);
binder::Status onUserStarted(int32_t userId);
binder::Status onUserStopped(int32_t userId);
diff --git a/VolumeManager.cpp b/VolumeManager.cpp
index 5cef239..e29b920 100644
--- a/VolumeManager.cpp
+++ b/VolumeManager.cpp
@@ -81,6 +81,7 @@
using android::vold::DeleteDirContents;
using android::vold::DeleteDirContentsAndDir;
using android::vold::EnsureDirExists;
+using android::vold::GetFuseMountPathForUser;
using android::vold::IsFilesystemSupported;
using android::vold::IsSdcardfsUsed;
using android::vold::IsVirtioBlkDevice;
@@ -424,10 +425,21 @@
}
}
-int VolumeManager::onUserAdded(userid_t userId, int userSerialNumber) {
+userid_t VolumeManager::getSharedStorageUser(userid_t userId) {
+ if (mSharedStorageUser.find(userId) == mSharedStorageUser.end()) {
+ return USER_UNKNOWN;
+ }
+ return mSharedStorageUser.at(userId);
+}
+
+int VolumeManager::onUserAdded(userid_t userId, int userSerialNumber,
+ userid_t sharesStorageWithUserId) {
LOG(INFO) << "onUserAdded: " << userId;
mAddedUsers[userId] = userSerialNumber;
+ if (sharesStorageWithUserId != USER_UNKNOWN) {
+ mSharedStorageUser[userId] = sharesStorageWithUserId;
+ }
return 0;
}
@@ -436,6 +448,7 @@
onUserStopped(userId);
mAddedUsers.erase(userId);
+ mSharedStorageUser.erase(userId);
return 0;
}
@@ -914,6 +927,7 @@
updateVirtualDisk();
mAddedUsers.clear();
mStartedUsers.clear();
+ mSharedStorageUser.clear();
// Abort all FUSE connections to avoid deadlocks if the FUSE daemon was killed
// with FUSE fds open.
diff --git a/VolumeManager.h b/VolumeManager.h
index a8117c9..943a144 100644
--- a/VolumeManager.h
+++ b/VolumeManager.h
@@ -104,9 +104,11 @@
const std::set<userid_t>& getStartedUsers() const { return mStartedUsers; }
+ userid_t getSharedStorageUser(userid_t userId);
+
int forgetPartition(const std::string& partGuid, const std::string& fsUuid);
- int onUserAdded(userid_t userId, int userSerialNumber);
+ int onUserAdded(userid_t userId, int userSerialNumber, userid_t cloneParentUserId);
int onUserRemoved(userid_t userId);
int onUserStarted(userid_t userId);
int onUserStopped(userid_t userId);
@@ -225,6 +227,8 @@
std::list<std::shared_ptr<android::vold::VolumeBase>> mInternalEmulatedVolumes;
std::unordered_map<userid_t, int> mAddedUsers;
+ // Map of users to a user with which they can share storage (eg clone profiles)
+ std::unordered_map<userid_t, userid_t> mSharedStorageUser;
// This needs to be a regular set because we care about the ordering here;
// user 0 should always go first, because it is responsible for sdcardfs.
std::set<userid_t> mStartedUsers;
diff --git a/binder/android/os/IVold.aidl b/binder/android/os/IVold.aidl
index 77478d9..c798959 100644
--- a/binder/android/os/IVold.aidl
+++ b/binder/android/os/IVold.aidl
@@ -30,7 +30,7 @@
void reset();
void shutdown();
- void onUserAdded(int userId, int userSerial);
+ void onUserAdded(int userId, int userSerial, int sharesStorageWithUserId);
void onUserRemoved(int userId);
void onUserStarted(int userId);
void onUserStopped(int userId);
diff --git a/model/EmulatedVolume.cpp b/model/EmulatedVolume.cpp
index 270d097..f99a369 100644
--- a/model/EmulatedVolume.cpp
+++ b/model/EmulatedVolume.cpp
@@ -18,6 +18,7 @@
#include "AppFuseUtil.h"
#include "Utils.h"
+#include "VolumeBase.h"
#include "VolumeManager.h"
#include <android-base/logging.h>
@@ -68,7 +69,7 @@
EmulatedVolume::~EmulatedVolume() {}
-std::string EmulatedVolume::getLabel() {
+std::string EmulatedVolume::getLabel() const {
// We could have migrated storage to an adopted private volume, so always
// call primary storage "emulated" to avoid media rescans.
if (getMountFlags() & MountFlags::kPrimary) {
@@ -91,6 +92,29 @@
return OK;
}
+// Bind mounts the volume 'volume' onto this volume.
+status_t EmulatedVolume::bindMountVolume(const EmulatedVolume& volume,
+ std::list<std::string>& pathsToUnmount) {
+ int myUserId = getMountUserId();
+ int volumeUserId = volume.getMountUserId();
+ std::string label = volume.getLabel();
+
+ // eg /mnt/user/10/emulated/10
+ std::string srcUserPath = GetFuseMountPathForUser(volumeUserId, label);
+ std::string srcPath = StringPrintf("%s/%d", srcUserPath.c_str(), volumeUserId);
+ // eg /mnt/user/0/emulated/10
+ std::string dstUserPath = GetFuseMountPathForUser(myUserId, label);
+ std::string dstPath = StringPrintf("%s/%d", dstUserPath.c_str(), volumeUserId);
+
+ auto status = doFuseBindMount(srcPath, dstPath, pathsToUnmount);
+ if (status == OK) {
+ // Store the mount path, so we can unmount it when this volume goes away
+ mSharedStorageMountPath = dstPath;
+ }
+
+ return status;
+}
+
status_t EmulatedVolume::mountFuseBindMounts() {
std::string androidSource;
std::string label = getLabel();
@@ -152,6 +176,59 @@
}
}
+ // For users that share their volume with another user (eg a clone
+ // profile), the current mount setup can cause page cache inconsistency
+ // issues. Let's say this is user 10, and the user it shares storage with
+ // is user 0.
+ // Then:
+ // * The FUSE daemon for user 0 serves /mnt/user/0
+ // * The FUSE daemon for user 10 serves /mnt/user/10
+ // The emulated volume for user 10 would be located at two paths:
+ // /mnt/user/0/emulated/10
+ // /mnt/user/10/emulated/10
+ // Since these paths refer to the same files but are served by different FUSE
+ // daemons, this can result in page cache inconsistency issues. To prevent this,
+ // bind mount the relevant paths for the involved users:
+ // 1. /mnt/user/10/emulated/10 =B=> /mnt/user/0/emulated/10
+ // 2. /mnt/user/0/emulated/0 =B=> /mnt/user/10/emulated/0
+ //
+ // This will ensure that any access to the volume for a specific user always
+ // goes through a single FUSE daemon.
+ userid_t sharedStorageUserId = VolumeManager::Instance()->getSharedStorageUser(userId);
+ if (sharedStorageUserId != USER_UNKNOWN) {
+ auto filter_fn = [&](const VolumeBase& vol) {
+ if (vol.getState() != VolumeBase::State::kMounted) {
+ // The volume must be mounted
+ return false;
+ }
+ if (vol.getType() != VolumeBase::Type::kEmulated) {
+ return false;
+ }
+ if (vol.getMountUserId() != sharedStorageUserId) {
+ return false;
+ }
+ if ((vol.getMountFlags() & MountFlags::kPrimary) == 0) {
+ // We only care about the primary emulated volume, so not a private
+ // volume with an emulated volume stacked on top.
+ return false;
+ }
+ return true;
+ };
+ auto vol = VolumeManager::Instance()->findVolumeWithFilter(filter_fn);
+ if (vol != nullptr) {
+ auto sharedVol = static_cast<EmulatedVolume*>(vol.get());
+ // Bind mount this volume in the other user's primary volume
+ status = sharedVol->bindMountVolume(*this, pathsToUnmount);
+ if (status != OK) {
+ return status;
+ }
+ // And vice-versa
+ status = bindMountVolume(*sharedVol, pathsToUnmount);
+ if (status != OK) {
+ return status;
+ }
+ }
+ }
unmount_guard.Disable();
return OK;
}
@@ -160,6 +237,14 @@
std::string label = getLabel();
int userId = getMountUserId();
+ if (!mSharedStorageMountPath.empty()) {
+ LOG(INFO) << "Unmounting " << mSharedStorageMountPath;
+ auto status = UnmountTree(mSharedStorageMountPath);
+ if (status != OK) {
+ LOG(ERROR) << "Failed to unmount " << mSharedStorageMountPath;
+ }
+ mSharedStorageMountPath = "";
+ }
if (mUseSdcardFs || mAppDataIsolationEnabled) {
std::string installerTarget(
StringPrintf("/mnt/installer/%d/%s/%d/Android/obb", userId, label.c_str(), userId));
diff --git a/model/EmulatedVolume.h b/model/EmulatedVolume.h
index 0f39fbd..50fda14 100644
--- a/model/EmulatedVolume.h
+++ b/model/EmulatedVolume.h
@@ -52,7 +52,9 @@
status_t mountFuseBindMounts();
status_t unmountFuseBindMounts();
- std::string getLabel();
+ status_t bindMountVolume(const EmulatedVolume& vol, std::list<std::string>& pathsToUnmount);
+
+ std::string getLabel() const;
std::string mRawPath;
std::string mLabel;
@@ -73,6 +75,9 @@
/* Whether to use app data isolation is enabled tor this volume */
bool mAppDataIsolationEnabled;
+ /* Location of bind mount for another profile that shares storage with us */
+ std::string mSharedStorageMountPath = "";
+
DISALLOW_COPY_AND_ASSIGN(EmulatedVolume);
};