commit 170333eb136ace469f02a31fc64eeeb75fdc8ff0
author Yifan Hong <elsk@google.com> Mon Feb 03 17:51:46 2020 -0800
committer Yifan Hong <elsk@google.com> Tue Feb 04 14:01:24 2020 -0800
tree c72c976065511da308ab4193dd3cb1b42f8b3c22
parent 45e688dffc27f2d623e188a58a1dda7439593c4f

libsnapshot::RemoveAllUpdateState log stack

Bug: 148818798
Test: apply OTA but cancel it in the middle, then
      delete /data/misc/update_engine/prefs/*, then
      reapply it again (to trigger CancelUpdate()).
      Stack is dumped.

Change-Id: I2dfb6b7f15b9d5854d0b81ed8ad260538d21c922

fs_mgr/libsnapshot/Android.bp

diff --git a/fs_mgr/libsnapshot/Android.bp b/fs_mgr/libsnapshot/Android.bp
index ad48b82..c58101a 100644
--- a/fs_mgr/libsnapshot/Android.bp
+++ b/fs_mgr/libsnapshot/Android.bp
@@ -95,6 +95,16 @@
     static_libs: [
         "libfs_mgr_binder"
     ],
+
+    shared_libs: [
+        // TODO(b/148818798): remove when parent bug is fixed
+        "libutilscallstack",
+    ],
+    cflags: [
+        "-g",
+        "-O0",
+        "-DLIBSNAPSHOT_USE_CALLSTACK",
+    ],
 }
 
 cc_library_static {
@@ -171,6 +181,9 @@
         "libsparse",
         "libutils",
         "libz",
+
+        // TODO(b/148818798): remove when parent bug is fixed
+        "libutilscallstack",
     ],
     static_libs: [
         "libgmock",
@@ -207,6 +220,9 @@
         "liblp",
         "libprotobuf-cpp-lite",
         "libutils",
+
+        // TODO(b/148818798): remove when parent bug is fixed.
+        "libutilscallstack",
     ],
     init_rc: [
         "snapshotctl.rc",

fs_mgr/libsnapshot/snapshot.cpp

diff --git a/fs_mgr/libsnapshot/snapshot.cpp b/fs_mgr/libsnapshot/snapshot.cpp
index a6f07fc..63a9302 100644
--- a/fs_mgr/libsnapshot/snapshot.cpp
+++ b/fs_mgr/libsnapshot/snapshot.cpp
@@ -21,6 +21,7 @@
 #include <sys/unistd.h>
 
 #include <optional>
+#include <sstream>
 #include <thread>
 #include <unordered_set>
 
@@ -37,6 +38,10 @@
 #include <libfiemap/image_manager.h>
 #include <liblp/liblp.h>
 
+#ifdef LIBSNAPSHOT_USE_CALLSTACK
+#include <utils/CallStack.h>
+#endif
+
 #include <android/snapshot/snapshot.pb.h>
 #include "device_info.h"
 #include "partition_cow_creator.h"
@@ -197,6 +202,22 @@
 }
 
 bool SnapshotManager::RemoveAllUpdateState(LockedFile* lock) {
+    LOG(INFO) << "Removing all update state.";
+
+#ifdef LIBSNAPSHOT_USE_CALLSTACK
+    LOG(WARNING) << "Logging stack; see b/148818798.";
+    // Do not use CallStack's log functions because snapshotctl relies on
+    // android-base/logging to save log to files.
+    // TODO(b/148818798): remove this before we ship.
+    CallStack callstack;
+    callstack.update();
+    auto callstack_str = callstack.toString();
+    LOG(WARNING) << callstack_str.c_str();
+    std::stringstream path;
+    path << "/data/misc/snapshotctl_log/libsnapshot." << Now() << ".log";
+    android::base::WriteStringToFile(callstack_str.c_str(), path.str());
+#endif
+
     if (!RemoveAllSnapshots(lock)) {
         LOG(ERROR) << "Could not remove all snapshots";
         return false;

fs_mgr/libsnapshot/snapshotctl.cpp

diff --git a/fs_mgr/libsnapshot/snapshotctl.cpp b/fs_mgr/libsnapshot/snapshotctl.cpp
index a0d0c03..9f23c45 100644
--- a/fs_mgr/libsnapshot/snapshotctl.cpp
+++ b/fs_mgr/libsnapshot/snapshotctl.cpp
@@ -27,6 +27,8 @@
 #include <libsnapshot/snapshot.h>
 #include "utility.h"
 
+#include "utility.h"
+
 using namespace std::string_literals;
 
 int Usage() {