From 583ae3e55da03f0f1d80f6067cf74471bdeda180 Mon Sep 17 00:00:00 2001
From: Alessio Balsini <balsini@google.com>
Date: Wed, 23 Mar 2022 18:27:59 +0000
Subject: [PATCH] FUSE-BPF: use both ro and persist properties

persist.sys.fuse.bpf.enable and ro.fuse.bpf.enabled are both used to
decide if FUSE-BPF must be enabled or not.
- ro.fuse.bpf.enabled is a read-only property that is set in the device
  makefile and would allow dogfooding devices to turn the feature
  on/off.
- persist.sys.fuse.bpf.enable is a system property that overrides
  ro.fuse.bpf.enabled and can only be set manually during the
  development to simplify the testing of FUSE-BPF, mostly to compare if
  those tests that are failing with FUSE-BPF were failing also without
  the feature.

Bug: 202785178
Test: adb logcat | grep "FuseDaemon" | grep BPF
Ignore-AOSP-First: FUSE-BPF is not available in AOSP
Signed-off-by: Alessio Balsini <balsini@google.com>
Change-Id: I23f9d27172907f6c72c73bea22e4a7e0ac643888
---
 Utils.cpp                | 10 ++++++++++
 Utils.h                  |  3 ++-
 model/EmulatedVolume.cpp |  4 ++--
 3 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/Utils.cpp b/Utils.cpp
index ba6afd8..e8049ed 100644
--- a/Utils.cpp
+++ b/Utils.cpp
@@ -1765,5 +1765,15 @@ std::pair<android::base::unique_fd, std::string> OpenDirInProcfs(std::string_vie
     return {std::move(fd), std::move(linkPath)};
 }
 
+bool IsFuseBpfEnabled() {
+    std::string bpf_override = android::base::GetProperty("persist.sys.fuse.bpf.override", "");
+    if (bpf_override == "true") {
+        return true;
+    } else if (bpf_override == "false") {
+        return false;
+    }
+    return base::GetBoolProperty("ro.fuse.bpf.enabled", false);
+}
+
 }  // namespace vold
 }  // namespace android
diff --git a/Utils.h b/Utils.h
index 71eb5eb..429669b 100644
--- a/Utils.h
+++ b/Utils.h
@@ -37,7 +37,6 @@ namespace vold {
 
 static const char* kVoldAppDataIsolationEnabled = "persist.sys.vold_app_data_isolation_enabled";
 static const char* kExternalStorageSdcardfs = "external_storage.sdcardfs.enabled";
-static const char* kFuseBpfEnabled = "persist.sys.fuse.bpf.override";
 
 static constexpr std::chrono::seconds kUntrustedFsckSleepTime(45);
 
@@ -206,6 +205,8 @@ status_t UnmountUserFuse(userid_t userId, const std::string& absolute_lower_path
 
 status_t PrepareAndroidDirs(const std::string& volumeRoot);
 
+bool IsFuseBpfEnabled();
+
 // Open a given directory as an FD, and return that and the corresponding procfs virtual
 // symlink path that can be used in any API that accepts a path string. Path stays valid until
 // the directory FD is closed.
diff --git a/model/EmulatedVolume.cpp b/model/EmulatedVolume.cpp
index 7c8a4e0..270d097 100644
--- a/model/EmulatedVolume.cpp
+++ b/model/EmulatedVolume.cpp
@@ -49,7 +49,7 @@ EmulatedVolume::EmulatedVolume(const std::string& rawPath, int userId)
     mRawPath = rawPath;
     mLabel = "emulated";
     mFuseMounted = false;
-    mFuseBpfEnabled = base::GetBoolProperty(kFuseBpfEnabled, false);
+    mFuseBpfEnabled = IsFuseBpfEnabled();
     mUseSdcardFs = IsSdcardfsUsed();
     mAppDataIsolationEnabled = base::GetBoolProperty(kVoldAppDataIsolationEnabled, false);
 }
@@ -61,7 +61,7 @@ EmulatedVolume::EmulatedVolume(const std::string& rawPath, dev_t device, const s
     mRawPath = rawPath;
     mLabel = fsUuid;
     mFuseMounted = false;
-    mFuseBpfEnabled = base::GetBoolProperty(kFuseBpfEnabled, false);
+    mFuseBpfEnabled = IsFuseBpfEnabled();
     mUseSdcardFs = IsSdcardfsUsed();
     mAppDataIsolationEnabled = base::GetBoolProperty(kVoldAppDataIsolationEnabled, false);
 }