commit 07466140fcbe9c3ee2d41106535cf339c1cac037
author Alessio Balsini <balsini@google.com> Thu Feb 20 01:06:57 2020 +0000
committer Alessio Balsini <balsini@google.com> Thu Feb 20 15:05:13 2020 +0000
tree 963f5c372d6ab5b1269368c09fe73f2594d5d81b
parent db6ef5e94931b90108f85966ddcd94642dd6852a

libsnapshot: fix stats write in Resume()

The Resume() operation is supposed to increment the resume counter, but
the updated counter value was not written to the device.
Fix by adding the write operation and refactoring the code.

Bug: none
Test: m
Change-Id: I3fffd61cc779c59e2780900809f0ce0b84258e78
Signed-off-by: Alessio Balsini <balsini@google.com>

fs_mgr/libsnapshot/snapshot_stats.cpp

diff --git a/fs_mgr/libsnapshot/snapshot_stats.cpp b/fs_mgr/libsnapshot/snapshot_stats.cpp
index c48509e..635b47d 100644
--- a/fs_mgr/libsnapshot/snapshot_stats.cpp
+++ b/fs_mgr/libsnapshot/snapshot_stats.cpp
@@ -36,36 +36,45 @@
     }
 }
 
-void SnapshotMergeStats::Start() {
-    SnapshotMergeReport report;
-    report.set_resume_count(0);
-    report.set_state(UpdateState::None);
-
+bool SnapshotMergeStats::ReadState() {
     std::string contents;
-    if (!report.SerializeToString(&contents)) {
+    if (!android::base::ReadFileToString(parent_.GetMergeStateFilePath(), &contents)) {
+        PLOG(INFO) << "Read merge statistics file failed";
+        return false;
+    }
+    if (!report_.ParseFromString(contents)) {
+        LOG(ERROR) << "Unable to parse merge statistics file as SnapshotMergeReport";
+        return false;
+    }
+    return true;
+}
+
+bool SnapshotMergeStats::WriteState() {
+    std::string contents;
+    if (!report_.SerializeToString(&contents)) {
         LOG(ERROR) << "Unable to serialize SnapshotMergeStats.";
-        return;
+        return false;
     }
     auto file_path = parent_.GetMergeStateFilePath();
     if (!WriteStringToFileAtomic(contents, file_path)) {
         PLOG(ERROR) << "Could not write to merge statistics file";
-        return;
+        return false;
     }
+    return true;
+}
+
+void SnapshotMergeStats::Start() {
+    report_.set_resume_count(0);
+    report_.set_state(UpdateState::None);
+    WriteState();
 }
 
 void SnapshotMergeStats::Resume() {
-    std::string contents;
-    if (!android::base::ReadFileToString(parent_.GetMergeStateFilePath(), &contents)) {
-        PLOG(INFO) << "Read merge statistics file failed";
+    if (!ReadState()) {
         return;
     }
-
-    if (!report_.ParseFromString(contents)) {
-        LOG(ERROR) << "Unable to parse merge statistics file as SnapshotMergeReport";
-        return;
-    }
-
     report_.set_resume_count(report_.resume_count() + 1);
+    WriteState();
 }
 
 void SnapshotMergeStats::set_state(android::snapshot::UpdateState state) {

fs_mgr/libsnapshot/snapshot_stats.h

diff --git a/fs_mgr/libsnapshot/snapshot_stats.h b/fs_mgr/libsnapshot/snapshot_stats.h
index 1ca9156..60109a4 100644
--- a/fs_mgr/libsnapshot/snapshot_stats.h
+++ b/fs_mgr/libsnapshot/snapshot_stats.h
@@ -32,6 +32,9 @@
     SnapshotMergeReport GetReport();
 
   private:
+    bool ReadState();
+    bool WriteState();
+
     const SnapshotManager& parent_;
     SnapshotMergeReport report_;
     std::chrono::time_point<std::chrono::steady_clock> init_time_;