Migrate primary external storage.
When requested, kick off a thread that will migrate storage contents
between two locations. This is performed in several steps that
also interact with the framework:
1. Take old and new volumes offline during migration
2. Wipe new location clean (10% of progress)
3. Copy files from old to new (60% of progress)
4. Inform framework that move was successful so it can persist
5. Wipe old location clean (15% of progress)
Derives a hacky progress estimate by using a rough proxy of free
disk space changes while a cp/rm is taking place.
Add new internal path for direct access to volumes to bypass any
FUSE emulation overhead, and send it to framework. Remove mutex
around various exec calls since setexeccon() is already per-thread.
Bug: 19993667
Change-Id: Ibcb4f6fe0126d05b2365f316f53e71dc3e79a2b8
diff --git a/MoveTask.cpp b/MoveTask.cpp
new file mode 100644
index 0000000..e0eec12
--- /dev/null
+++ b/MoveTask.cpp
@@ -0,0 +1,217 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "MoveTask.h"
+#include "Utils.h"
+#include "VolumeManager.h"
+#include "ResponseCode.h"
+
+#include <base/stringprintf.h>
+#include <base/logging.h>
+#include <private/android_filesystem_config.h>
+
+#include <dirent.h>
+#include <sys/wait.h>
+
+#define CONSTRAIN(amount, low, high) (amount < low ? low : (amount > high ? high : amount))
+
+using android::base::StringPrintf;
+
+namespace android {
+namespace vold {
+
+// TODO: keep in sync with PackageManager
+static const int kMoveSucceeded = -100;
+static const int kMoveFailedInternalError = -6;
+
+static const char* kCpPath = "/system/bin/cp";
+static const char* kRmPath = "/system/bin/rm";
+
+MoveTask::MoveTask(const std::shared_ptr<VolumeBase>& from,
+ const std::shared_ptr<VolumeBase>& to) :
+ mFrom(from), mTo(to) {
+}
+
+MoveTask::~MoveTask() {
+}
+
+void MoveTask::start() {
+ mThread = std::thread(&MoveTask::run, this);
+}
+
+static void notifyProgress(int progress) {
+ VolumeManager::Instance()->getBroadcaster()->sendBroadcast(ResponseCode::MoveStatus,
+ StringPrintf("%d", progress).c_str(), false);
+}
+
+static status_t pushBackContents(const std::string& path, std::vector<std::string>& cmd) {
+ DIR* dir = opendir(path.c_str());
+ if (dir == NULL) {
+ return -1;
+ }
+ bool found = false;
+ struct dirent* ent;
+ while ((ent = readdir(dir)) != NULL) {
+ if ((!strcmp(ent->d_name, ".")) || (!strcmp(ent->d_name, ".."))) {
+ continue;
+ }
+ cmd.push_back(StringPrintf("%s/%s", path.c_str(), ent->d_name));
+ found = true;
+ }
+ closedir(dir);
+ return found ? OK : -1;
+}
+
+static status_t execRm(const std::string& path, int startProgress, int stepProgress) {
+ notifyProgress(startProgress);
+
+ uint64_t expectedBytes = GetTreeBytes(path);
+ uint64_t startFreeBytes = GetFreeBytes(path);
+
+ std::vector<std::string> cmd;
+ cmd.push_back(kRmPath);
+ cmd.push_back("-f"); /* force: remove without confirmation, no error if it doesn't exist */
+ cmd.push_back("-R"); /* recursive: remove directory contents */
+ if (pushBackContents(path, cmd) != OK) {
+ LOG(WARNING) << "No contents in " << path;
+ return OK;
+ }
+
+ pid_t pid = ForkExecvpAsync(cmd);
+ if (pid == -1) return -1;
+
+ int status;
+ while (true) {
+ if (waitpid(pid, &status, WNOHANG) == pid) {
+ if (WIFEXITED(status)) {
+ LOG(DEBUG) << "Finished rm with status " << WEXITSTATUS(status);
+ return (WEXITSTATUS(status) == 0) ? OK : -1;
+ } else {
+ break;
+ }
+ }
+
+ sleep(1);
+ uint64_t deltaFreeBytes = GetFreeBytes(path) - startFreeBytes;
+ notifyProgress(startProgress + CONSTRAIN((int)
+ ((deltaFreeBytes * stepProgress) / expectedBytes), 0, stepProgress));
+ }
+ return -1;
+}
+
+static status_t execCp(const std::string& fromPath, const std::string& toPath,
+ int startProgress, int stepProgress) {
+ notifyProgress(startProgress);
+
+ uint64_t expectedBytes = GetTreeBytes(fromPath);
+ uint64_t startFreeBytes = GetFreeBytes(toPath);
+
+ std::vector<std::string> cmd;
+ cmd.push_back(kCpPath);
+ cmd.push_back("-p"); /* preserve timestamps, ownership, and permissions */
+ cmd.push_back("-R"); /* recurse into subdirectories (DEST must be a directory) */
+ cmd.push_back("-P"); /* Do not follow symlinks [default] */
+ cmd.push_back("-d"); /* don't dereference symlinks */
+ if (pushBackContents(fromPath, cmd) != OK) {
+ LOG(WARNING) << "No contents in " << fromPath;
+ return OK;
+ }
+ cmd.push_back(toPath.c_str());
+
+ pid_t pid = ForkExecvpAsync(cmd);
+ if (pid == -1) return -1;
+
+ int status;
+ while (true) {
+ if (waitpid(pid, &status, WNOHANG) == pid) {
+ if (WIFEXITED(status)) {
+ LOG(DEBUG) << "Finished cp with status " << WEXITSTATUS(status);
+ return (WEXITSTATUS(status) == 0) ? OK : -1;
+ } else {
+ break;
+ }
+ }
+
+ sleep(1);
+ uint64_t deltaFreeBytes = startFreeBytes - GetFreeBytes(toPath);
+ notifyProgress(startProgress + CONSTRAIN((int)
+ ((deltaFreeBytes * stepProgress) / expectedBytes), 0, stepProgress));
+ }
+ return -1;
+}
+
+static void bringOffline(const std::shared_ptr<VolumeBase>& vol) {
+ vol->destroy();
+ vol->setSilent(true);
+ vol->create();
+ vol->setMountFlags(0);
+ vol->mount();
+}
+
+static void bringOnline(const std::shared_ptr<VolumeBase>& vol) {
+ vol->destroy();
+ vol->setSilent(false);
+ vol->create();
+}
+
+void MoveTask::run() {
+ std::string fromPath;
+ std::string toPath;
+
+ // TODO: add support for public volumes
+ if (mFrom->getType() != VolumeBase::Type::kEmulated) goto fail;
+ if (mTo->getType() != VolumeBase::Type::kEmulated) goto fail;
+
+ // Step 1: tear down volumes and mount silently without making
+ // visible to userspace apps
+ bringOffline(mFrom);
+ bringOffline(mTo);
+
+ fromPath = mFrom->getInternalPath();
+ toPath = mTo->getInternalPath();
+
+ // Step 2: clean up any stale data
+ if (execRm(toPath, 10, 10) != OK) {
+ goto fail;
+ }
+
+ // Step 3: perform actual copy
+ if (execCp(fromPath, toPath, 20, 60) != OK) {
+ goto fail;
+ }
+
+ // NOTE: MountService watches for this magic value to know
+ // that move was successful
+ notifyProgress(82);
+ bringOnline(mFrom);
+ bringOnline(mTo);
+
+ // Step 4: clean up old data
+ if (execRm(fromPath, 85, 15) != OK) {
+ goto fail;
+ }
+
+ notifyProgress(kMoveSucceeded);
+ return;
+fail:
+ bringOnline(mFrom);
+ bringOnline(mTo);
+ notifyProgress(kMoveFailedInternalError);
+ return;
+}
+
+} // namespace vold
+} // namespace android