libprocessgroup: Move fd caching code into FdCacheHelper
Refactor file descriptor caching code and move it into FdCacheHelper
because later on when we introduce fd caching for SetProcessProfiles
the children of CachedFdProfileAction become different enough that
sharing the same parent becomes a hindrance.
Bug: 215557553
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Change-Id: If3812a0090c81a29e25f0888b0511cfaf48edea3
diff --git a/libprocessgroup/task_profiles.cpp b/libprocessgroup/task_profiles.cpp
index 3834f91..a61700c 100644
--- a/libprocessgroup/task_profiles.cpp
+++ b/libprocessgroup/task_profiles.cpp
@@ -51,6 +51,67 @@
static constexpr const char* TEMPLATE_TASK_PROFILE_API_FILE =
"/etc/task_profiles/task_profiles_%u.json";
+class FdCacheHelper {
+ public:
+ enum FdState {
+ FDS_INACCESSIBLE = -1,
+ FDS_APP_DEPENDENT = -2,
+ FDS_NOT_CACHED = -3,
+ };
+
+ static void Cache(const std::string& path, android::base::unique_fd& fd);
+ static void Drop(android::base::unique_fd& fd);
+ static void Init(const std::string& path, android::base::unique_fd& fd);
+ static bool IsCached(const android::base::unique_fd& fd) { return fd > FDS_INACCESSIBLE; }
+
+ private:
+ static bool IsAppDependentPath(const std::string& path);
+};
+
+void FdCacheHelper::Init(const std::string& path, android::base::unique_fd& fd) {
+ // file descriptors for app-dependent paths can't be cached
+ if (IsAppDependentPath(path)) {
+ // file descriptor is not cached
+ fd.reset(FDS_APP_DEPENDENT);
+ return;
+ }
+ // file descriptor can be cached later on request
+ fd.reset(FDS_NOT_CACHED);
+}
+
+void FdCacheHelper::Cache(const std::string& path, android::base::unique_fd& fd) {
+ if (fd != FDS_NOT_CACHED) {
+ return;
+ }
+
+ if (access(path.c_str(), W_OK) != 0) {
+ // file is not accessible
+ fd.reset(FDS_INACCESSIBLE);
+ return;
+ }
+
+ unique_fd tmp_fd(TEMP_FAILURE_RETRY(open(path.c_str(), O_WRONLY | O_CLOEXEC)));
+ if (tmp_fd < 0) {
+ PLOG(ERROR) << "Failed to cache fd '" << path << "'";
+ fd.reset(FDS_INACCESSIBLE);
+ return;
+ }
+
+ fd = std::move(tmp_fd);
+}
+
+void FdCacheHelper::Drop(android::base::unique_fd& fd) {
+ if (fd == FDS_NOT_CACHED) {
+ return;
+ }
+
+ fd.reset(FDS_NOT_CACHED);
+}
+
+bool FdCacheHelper::IsAppDependentPath(const std::string& path) {
+ return path.find("<uid>", 0) != std::string::npos || path.find("<pid>", 0) != std::string::npos;
+}
+
void ProfileAttribute::Reset(const CgroupController& controller, const std::string& file_name) {
controller_ = controller;
file_name_ = file_name;
@@ -144,57 +205,9 @@
return true;
}
-void CachedFdProfileAction::EnableResourceCaching() {
- std::lock_guard<std::mutex> lock(fd_mutex_);
- if (fd_ != FDS_NOT_CACHED) {
- return;
- }
-
- std::string tasks_path = GetPath();
-
- if (access(tasks_path.c_str(), W_OK) != 0) {
- // file is not accessible
- fd_.reset(FDS_INACCESSIBLE);
- return;
- }
-
- unique_fd fd(TEMP_FAILURE_RETRY(open(tasks_path.c_str(), O_WRONLY | O_CLOEXEC)));
- if (fd < 0) {
- PLOG(ERROR) << "Failed to cache fd '" << tasks_path << "'";
- fd_.reset(FDS_INACCESSIBLE);
- return;
- }
-
- fd_ = std::move(fd);
-}
-
-void CachedFdProfileAction::DropResourceCaching() {
- std::lock_guard<std::mutex> lock(fd_mutex_);
- if (fd_ == FDS_NOT_CACHED) {
- return;
- }
-
- fd_.reset(FDS_NOT_CACHED);
-}
-
-bool CachedFdProfileAction::IsAppDependentPath(const std::string& path) {
- return path.find("<uid>", 0) != std::string::npos || path.find("<pid>", 0) != std::string::npos;
-}
-
-void CachedFdProfileAction::InitFd(const std::string& path) {
- // file descriptors for app-dependent paths can't be cached
- if (IsAppDependentPath(path)) {
- // file descriptor is not cached
- fd_.reset(FDS_APP_DEPENDENT);
- return;
- }
- // file descriptor can be cached later on request
- fd_.reset(FDS_NOT_CACHED);
-}
-
SetCgroupAction::SetCgroupAction(const CgroupController& c, const std::string& p)
: controller_(c), path_(p) {
- InitFd(controller_.GetTasksFilePath(path_));
+ FdCacheHelper::Init(controller_.GetTasksFilePath(path_), fd_);
}
bool SetCgroupAction::AddTidToCgroup(int tid, int fd, const char* controller_name) {
@@ -249,7 +262,7 @@
bool SetCgroupAction::ExecuteForTask(int tid) const {
std::lock_guard<std::mutex> lock(fd_mutex_);
- if (IsFdValid()) {
+ if (FdCacheHelper::IsCached(fd_)) {
// fd is cached, reuse it
if (!AddTidToCgroup(tid, fd_, controller()->name())) {
LOG(ERROR) << "Failed to add task into cgroup";
@@ -258,12 +271,12 @@
return true;
}
- if (fd_ == FDS_INACCESSIBLE) {
+ if (fd_ == FdCacheHelper::FDS_INACCESSIBLE) {
// no permissions to access the file, ignore
return true;
}
- if (fd_ == FDS_APP_DEPENDENT) {
+ if (fd_ == FdCacheHelper::FDS_APP_DEPENDENT) {
// application-dependent path can't be used with tid
PLOG(ERROR) << "Application profile can't be applied to a thread";
return false;
@@ -284,10 +297,20 @@
return true;
}
+void SetCgroupAction::EnableResourceCaching() {
+ std::lock_guard<std::mutex> lock(fd_mutex_);
+ FdCacheHelper::Cache(controller_.GetTasksFilePath(path_), fd_);
+}
+
+void SetCgroupAction::DropResourceCaching() {
+ std::lock_guard<std::mutex> lock(fd_mutex_);
+ FdCacheHelper::Drop(fd_);
+}
+
WriteFileAction::WriteFileAction(const std::string& path, const std::string& value,
bool logfailures)
: path_(path), value_(value), logfailures_(logfailures) {
- InitFd(path_);
+ FdCacheHelper::Init(path_, fd_);
}
bool WriteFileAction::WriteValueToFile(const std::string& value, const std::string& path,
@@ -330,7 +353,7 @@
value = StringReplace(value, "<uid>", std::to_string(uid), true);
value = StringReplace(value, "<pid>", std::to_string(tid), true);
- if (IsFdValid()) {
+ if (FdCacheHelper::IsCached(fd_)) {
// fd is cached, reuse it
if (!WriteStringToFd(value, fd_)) {
if (logfailures_) PLOG(ERROR) << "Failed to write '" << value << "' to " << path_;
@@ -339,12 +362,12 @@
return true;
}
- if (fd_ == FDS_INACCESSIBLE) {
+ if (fd_ == FdCacheHelper::FDS_INACCESSIBLE) {
// no permissions to access the file, ignore
return true;
}
- if (fd_ == FDS_APP_DEPENDENT) {
+ if (fd_ == FdCacheHelper::FDS_APP_DEPENDENT) {
// application-dependent path can't be used with tid
PLOG(ERROR) << "Application profile can't be applied to a thread";
return false;
@@ -353,6 +376,16 @@
return WriteValueToFile(value, path_, logfailures_);
}
+void WriteFileAction::EnableResourceCaching() {
+ std::lock_guard<std::mutex> lock(fd_mutex_);
+ FdCacheHelper::Cache(path_, fd_);
+}
+
+void WriteFileAction::DropResourceCaching() {
+ std::lock_guard<std::mutex> lock(fd_mutex_);
+ FdCacheHelper::Drop(fd_);
+}
+
bool ApplyProfileAction::ExecuteForProcess(uid_t uid, pid_t pid) const {
for (const auto& profile : profiles_) {
if (!profile->ExecuteForProcess(uid, pid)) {
@@ -457,8 +490,7 @@
android::base::StringPrintf(TEMPLATE_TASK_PROFILE_API_FILE, api_level);
if (!access(api_profiles_path.c_str(), F_OK) || errno != ENOENT) {
if (!Load(CgroupMap::GetInstance(), api_profiles_path)) {
- LOG(ERROR) << "Loading " << api_profiles_path << " for [" << getpid()
- << "] failed";
+ LOG(ERROR) << "Loading " << api_profiles_path << " for [" << getpid() << "] failed";
}
}
}