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

@@ -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

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.

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);
 }