Make Loop::destroyAll() smarter.

Instead of blindly looping across 4096 possible devices, use
readdir() to only look at valid devices.  This speeds up destroyAll()
from 40ms to 0.7ms.

Add tracing information in several places.

Test: external/chromium-trace/systrace.py -b 128768 sched freq am pm ss core_services binder_driver -a system_server,installd,vold
Bug: 65634729, 65737446
Change-Id: If581de47fb55850c0fcd6e25bf33ed246e1b079d

Devmapper.cpp

@@ -14,6 +14,8 @@
  * limitations under the License.
  */
 
+#define ATRACE_TAG ATRACE_TAG_PACKAGE_MANAGER
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <fcntl.h>
@@ -34,6 +36,7 @@
 
 #include <android-base/logging.h>
 #include <android-base/stringprintf.h>
+#include <utils/Trace.h>
 
 #include "Devmapper.h"
 
@@ -233,6 +236,7 @@ int Devmapper::destroy(const char *name_raw) {
 }
 
 int Devmapper::destroyAll() {
+    ATRACE_NAME("Devmapper::destroyAll");
     char *buffer = (char *) malloc(1024 * 64);
     if (!buffer) {
         SLOGE("Error allocating memory (%s)", strerror(errno));

Loop.cpp

@@ -14,8 +14,11 @@
  * limitations under the License.
  */
 
+#define ATRACE_TAG ATRACE_TAG_PACKAGE_MANAGER
+
 #include <stdio.h>
 #include <stdlib.h>
+#include <dirent.h>
 #include <fcntl.h>
 #include <unistd.h>
 #include <errno.h>
@@ -35,6 +38,7 @@
 #include <android-base/logging.h>
 #include <android-base/stringprintf.h>
 #include <android-base/unique_fd.h>
+#include <utils/Trace.h>
 
 #include "Loop.h"
 #include "VoldUtil.h"
@@ -262,9 +266,22 @@ int Loop::destroyByDevice(const char *loopDevice) {
 }
 
 int Loop::destroyAll() {
-    for (int i = 0; i < LOOP_MAX; i++) {
-        auto path = StringPrintf("/dev/block/loop%d", i);
+    ATRACE_NAME("Loop::destroyAll");
 
+    DIR* dir;
+    struct dirent* de;
+
+    std::string root = "/dev/block/";
+    if (!(dir = opendir(root.c_str()))) {
+        PLOG(ERROR) << "Failed to opendir";
+        return -1;
+    }
+
+    // Poke through all devices looking for loops
+    while ((de = readdir(dir))) {
+        if (strncmp(de->d_name, "loop", 4) != 0) continue;
+
+        auto path = root + de->d_name;
         unique_fd fd(open(path.c_str(), O_RDWR | O_CLOEXEC));
         if (fd.get() == -1) {
             if (errno != ENOENT) {
@@ -290,6 +307,8 @@ int Loop::destroyAll() {
             LOG(VERBOSE) << "Found unmanaged loop device at " << path << " named " << id;
         }
     }
+
+    closedir(dir);
     return 0;
 }
 

VoldNativeService.cpp

@@ -14,6 +14,8 @@
  * limitations under the License.
  */
 
+#define ATRACE_TAG ATRACE_TAG_PACKAGE_MANAGER
+
 #include "VoldNativeService.h"
 #include "VolumeManager.h"
 #include "BenchmarkTask.h"
@@ -32,6 +34,7 @@
 #include <android-base/strings.h>
 #include <fs_mgr.h>
 #include <private/android_filesystem_config.h>
+#include <utils/Trace.h>
 
 #ifndef LOG_TAG
 #define LOG_TAG "vold"
@@ -169,10 +172,12 @@ binder::Status checkArgumentHex(const std::string& hex) {
 }
 
 #define ACQUIRE_LOCK \
-    std::lock_guard<std::mutex> lock(VolumeManager::Instance()->getLock());
+    std::lock_guard<std::mutex> lock(VolumeManager::Instance()->getLock()); \
+    ATRACE_CALL();
 
 #define ACQUIRE_CRYPT_LOCK \
-    std::lock_guard<std::mutex> lock(VolumeManager::Instance()->getCryptLock());
+    std::lock_guard<std::mutex> lock(VolumeManager::Instance()->getCryptLock()); \
+    ATRACE_CALL();
 
 }  // namespace
 

VolumeManager.cpp

@@ -14,6 +14,8 @@
  * limitations under the License.
  */
 
+#define ATRACE_TAG ATRACE_TAG_PACKAGE_MANAGER
+
 #include <dirent.h>
 #include <errno.h>
 #include <fcntl.h>
@@ -40,6 +42,7 @@
 #include <android-base/stringprintf.h>
 #include <cutils/fs.h>
 #include <cutils/log.h>
+#include <utils/Trace.h>
 
 #include <selinux/android.h>
 
@@ -94,6 +97,7 @@ VolumeManager::~VolumeManager() {
 }
 
 int VolumeManager::updateVirtualDisk() {
+    ATRACE_NAME("VolumeManager::updateVirtualDisk");
     if (property_get_bool(kPropVirtualDisk, false)) {
         if (access(kPathVirtualDisk, F_OK) != 0) {
             Loop::createImageFile(kPathVirtualDisk, kSizeVirtualDisk / 512);
@@ -148,6 +152,8 @@ int VolumeManager::setDebug(bool enable) {
 }
 
 int VolumeManager::start() {
+    ATRACE_NAME("VolumeManager::start");
+
     // Always start from a clean slate by unmounting everything in
     // directories that we own, in case we crashed.
     unmountAll();
@@ -548,6 +554,7 @@ int VolumeManager::shutdown() {
 
 int VolumeManager::unmountAll() {
     std::lock_guard<std::mutex> lock(mLock);
+    ATRACE_NAME("VolumeManager::unmountAll()");
 
     // First, try gracefully unmounting all known devices
     if (mInternalEmulated != nullptr) {

main.cpp

@@ -14,6 +14,8 @@
  * limitations under the License.
  */
 
+#define ATRACE_TAG ATRACE_TAG_PACKAGE_MANAGER
+
 #include "model/Disk.h"
 #include "VolumeManager.h"
 #include "NetlinkManager.h"
@@ -25,6 +27,7 @@
 #include <android-base/stringprintf.h>
 #include <cutils/klog.h>
 #include <cutils/properties.h>
+#include <utils/Trace.h>
 
 #include <stdio.h>
 #include <stdlib.h>
@@ -51,6 +54,8 @@ int main(int argc, char** argv) {
     setenv("ANDROID_LOG_TAGS", "*:v", 1);
     android::base::InitLogging(argv, android::base::LogdLogger(android::base::SYSTEM));
 
+    ATRACE_BEGIN("main");
+
     LOG(INFO) << "Vold 3.0 (the awakening) firing up";
 
     LOG(VERBOSE) << "Detected support for:"
@@ -93,10 +98,12 @@ int main(int argc, char** argv) {
         exit(1);
     }
 
+    ATRACE_BEGIN("VoldNativeService::start");
     if (android::vold::VoldNativeService::start() != android::OK) {
         LOG(ERROR) << "Unable to start VoldNativeService";
         exit(1);
     }
+    ATRACE_END();
 
     bool has_adoptable;
     bool has_quota;
@@ -105,10 +112,12 @@ int main(int argc, char** argv) {
         PLOG(ERROR) << "Error reading configuration... continuing anyways";
     }
 
+    ATRACE_BEGIN("NetlinkManager::start");
     if (nm->start()) {
         PLOG(ERROR) << "Unable to start NetlinkManager";
         exit(1);
     }
+    ATRACE_END();
 
     // This call should go after listeners are started to avoid
     // a deadlock between vold and init (see b/34278978 for details)
@@ -119,6 +128,9 @@ int main(int argc, char** argv) {
     // also the cold boot is needed in case we have flash drive
     // connected before Vold launched
     coldboot("/sys/block");
+
+    ATRACE_END();
+
     // Eventually we'll become the monitoring thread
     while(1) {
         pause();
@@ -188,6 +200,7 @@ static void do_coldboot(DIR *d, int lvl) {
 }
 
 static void coldboot(const char *path) {
+    ATRACE_NAME("coldboot");
     DIR *d = opendir(path);
     if(d) {
         do_coldboot(d, 0);
@@ -196,6 +209,8 @@ static void coldboot(const char *path) {
 }
 
 static int process_config(VolumeManager *vm, bool* has_adoptable, bool* has_quota) {
+    ATRACE_NAME("process_config");
+
     fstab = fs_mgr_read_fstab_default();
     if (!fstab) {
         PLOG(ERROR) << "Failed to open default fstab";