Add support for checkpointing
Checkpointing uses a combination of files on the meta partition
and the checkpoint= fs_mgr flag. Checkpointed partitions will
revert to their starting state on reboot unless checkpoint commit
is called.
Test: Run vdc commands, check file on metadata
Merged-In: Icba16578608a6cbf922472e9d4ae5b8cf5f016c6
Change-Id: Icba16578608a6cbf922472e9d4ae5b8cf5f016c6
diff --git a/Checkpoint.cpp b/Checkpoint.cpp
new file mode 100644
index 0000000..476b0ae
--- /dev/null
+++ b/Checkpoint.cpp
@@ -0,0 +1,109 @@
+/*
+ * Copyright (C) 2018 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.
+ */
+
+#define LOG_TAG "Checkpoint"
+#include "Checkpoint.h"
+
+#include <android-base/file.h>
+#include <android-base/parseint.h>
+#include <cutils/android_reboot.h>
+#include <fs_mgr.h>
+#include <mntent.h>
+#include <sys/mount.h>
+
+#include <list>
+#include <string>
+
+namespace android {
+namespace vold {
+
+static const std::string kMetadataCPFile = "/metadata/vold/checkpoint";
+
+bool cp_startCheckpoint(int retry) {
+ if (retry < -1) return false;
+ std::string content = std::to_string(retry);
+ return android::base::WriteStringToFile(content, kMetadataCPFile);
+}
+
+bool cp_commitChanges() {
+ struct fstab* fstab = fs_mgr_read_fstab_default();
+ if (!fstab) return false;
+
+ FILE* fp = setmntent("/proc/mounts", "r");
+ mntent* mentry;
+
+ if (fp == NULL) return false;
+
+ while ((mentry = getmntent(fp)) != NULL) {
+ auto test = std::string(mentry->mnt_dir) + "/";
+ for (int i = 0; i < fstab->num_entries; i++) {
+ if (!fs_mgr_is_checkpoint(&fstab->recs[i])) continue;
+
+ if (!strcmp(fstab->recs[i].mount_point, mentry->mnt_dir) &&
+ !strcmp(fstab->recs[i].fs_type, mentry->mnt_type)) {
+ if (!strcmp(fstab->recs[i].fs_type, "f2fs")) {
+ mount(mentry->mnt_fsname, mentry->mnt_dir, "none",
+ MS_REMOUNT | fstab->recs[i].flags, "checkpoint=enable");
+ }
+ }
+ }
+ }
+ endmntent(fp);
+
+ fs_mgr_free_fstab(fstab);
+ return android::base::RemoveFileIfExists(kMetadataCPFile);
+}
+
+void cp_abortChanges() {
+ android_reboot(ANDROID_RB_RESTART2, 0, nullptr);
+}
+
+bool cp_needRollback(const std::string& id) {
+ std::string content;
+ bool ret;
+
+ ret = android::base::ReadFileToString(kMetadataCPFile, &content);
+ if (ret) return content == "0";
+ return false;
+}
+
+bool cp_needsCheckpoint(void) {
+ bool ret;
+ std::string content;
+
+ ret = android::base::ReadFileToString(kMetadataCPFile, &content);
+ if (ret) return content != "0";
+ return false;
+}
+
+bool cp_prepareDriveForCheckpoint(const std::string& mountPoint) {
+ return false;
+}
+
+bool cp_markBootAttempt() {
+ std::string oldContent, newContent;
+ int retry = 0;
+ if (!android::base::ReadFileToString(kMetadataCPFile, &oldContent)) return false;
+
+ if (!android::base::ParseInt(oldContent, &retry)) return false;
+ if (retry > 0) retry--;
+
+ newContent = std::to_string(retry);
+ return android::base::WriteStringToFile(newContent, kMetadataCPFile);
+}
+
+} // namespace vold
+} // namespace android