ueventd: parallelize restorecon /sys
generate subdir for /sys and /sys/devices, handle restorecon in parallel.
This reduces coldboot time on our target about 300ms.
Change-Id: I9c3d0e97aacff0ca127880d936dfd5fcc2aee125
diff --git a/init/ueventd.cpp b/init/ueventd.cpp
index 8b2cf62..cffc1b9 100644
--- a/init/ueventd.cpp
+++ b/init/ueventd.cpp
@@ -17,12 +17,15 @@
#include "ueventd.h"
#include <ctype.h>
+#include <dirent.h>
#include <fcntl.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
+#include <sys/stat.h>
#include <sys/wait.h>
+#include <unistd.h>
#include <set>
#include <thread>
@@ -121,8 +124,9 @@
void UeventHandlerMain(unsigned int process_num, unsigned int total_processes);
void RegenerateUevents();
void ForkSubProcesses();
- void DoRestoreCon();
void WaitForSubProcesses();
+ void RestoreConHandler(unsigned int process_num, unsigned int total_processes);
+ void GenerateRestoreCon(const std::string& directory);
UeventListener& uevent_listener_;
std::vector<std::unique_ptr<UeventHandler>>& uevent_handlers_;
@@ -131,6 +135,8 @@
std::vector<Uevent> uevent_queue_;
std::set<pid_t> subprocess_pids_;
+
+ std::vector<std::string> restorecon_queue_;
};
void ColdBoot::UeventHandlerMain(unsigned int process_num, unsigned int total_processes) {
@@ -141,9 +147,38 @@
uevent_handler->HandleUevent(uevent);
}
}
+}
+
+void ColdBoot::RestoreConHandler(unsigned int process_num, unsigned int total_processes) {
+ for (unsigned int i = process_num; i < restorecon_queue_.size(); i += total_processes) {
+ auto& dir = restorecon_queue_[i];
+
+ selinux_android_restorecon(dir.c_str(), SELINUX_ANDROID_RESTORECON_RECURSE);
+ }
_exit(EXIT_SUCCESS);
}
+void ColdBoot::GenerateRestoreCon(const std::string& directory) {
+ std::unique_ptr<DIR, decltype(&closedir)> dir(opendir(directory.c_str()), &closedir);
+
+ if (!dir) return;
+
+ struct dirent* dent;
+ while ((dent = readdir(dir.get())) != NULL) {
+ if (strcmp(dent->d_name, ".") == 0 || strcmp(dent->d_name, "..") == 0) continue;
+
+ struct stat st;
+ if (fstatat(dirfd(dir.get()), dent->d_name, &st, 0) == -1) continue;
+
+ if (S_ISDIR(st.st_mode)) {
+ std::string fullpath = directory + "/" + dent->d_name;
+ if (fullpath != "/sys/devices") {
+ restorecon_queue_.emplace_back(fullpath);
+ }
+ }
+ }
+}
+
void ColdBoot::RegenerateUevents() {
uevent_listener_.RegenerateUevents([this](const Uevent& uevent) {
uevent_queue_.emplace_back(uevent);
@@ -160,16 +195,13 @@
if (pid == 0) {
UeventHandlerMain(i, num_handler_subprocesses_);
+ RestoreConHandler(i, num_handler_subprocesses_);
}
subprocess_pids_.emplace(pid);
}
}
-void ColdBoot::DoRestoreCon() {
- selinux_android_restorecon("/sys", SELINUX_ANDROID_RESTORECON_RECURSE);
-}
-
void ColdBoot::WaitForSubProcesses() {
// Treat subprocesses that crash or get stuck the same as if ueventd itself has crashed or gets
// stuck.
@@ -208,9 +240,13 @@
RegenerateUevents();
- ForkSubProcesses();
+ selinux_android_restorecon("/sys", 0);
+ selinux_android_restorecon("/sys/devices", 0);
+ GenerateRestoreCon("/sys");
+ // takes long time for /sys/devices, parallelize it
+ GenerateRestoreCon("/sys/devices");
- DoRestoreCon();
+ ForkSubProcesses();
WaitForSubProcesses();