Use Libcore.os.stat instead of FileUtils

PackageManagerService just needed to know the owner for this file, so
just use stat instead so we can remove the old JNI code.

This is the last user of FileUtils#getPermissions so just remove the
FileUtils method as well.

Change-Id: I953057cd6b9de4410f33b6f22e4bddff02fe2988

Author: kruton

core/java/android/os/FileUtils.java

@@ -28,9 +28,6 @@
 import java.util.zip.CRC32;
 import java.util.zip.CheckedInputStream;
 
-import libcore.io.Os;
-import libcore.io.StructStat;
-
 /**
  * Tools for managing files.  Not for public consumption.
  * @hide
@@ -96,12 +93,6 @@ public static boolean getFileStatus(String path, FileStatus status) {
 
     public static native int setPermissions(String file, int mode, int uid, int gid);
 
-    /**
-     * @deprecated use {@link Os#stat(String)} instead.
-     */
-    @Deprecated
-    public static native int getPermissions(String file, int[] outPermissions);
-
     public static native int setUMask(int mask);
 
     /** returns the FAT file system volume ID for the volume mounted 

core/jni/android_os_FileUtils.cpp

@@ -68,39 +68,6 @@ jint android_os_FileUtils_setPermissions(JNIEnv* env, jobject clazz,
     return chmod(file8.string(), mode) == 0 ? 0 : errno;
 }
 
-jint android_os_FileUtils_getPermissions(JNIEnv* env, jobject clazz,
-                                         jstring file, jintArray outArray)
-{
-    const jchar* str = env->GetStringCritical(file, 0);
-    String8 file8;
-    if (str) {
-        file8 = String8(str, env->GetStringLength(file));
-        env->ReleaseStringCritical(file, str);
-    }
-    if (file8.size() <= 0) {
-        return ENOENT;
-    }
-    struct stat st;
-    if (stat(file8.string(), &st) != 0) {
-        return errno;
-    }
-    jint* array = (jint*)env->GetPrimitiveArrayCritical(outArray, 0);
-    if (array) {
-        int len = env->GetArrayLength(outArray);
-        if (len >= 1) {
-            array[0] = st.st_mode;
-        }
-        if (len >= 2) {
-            array[1] = st.st_uid;
-        }
-        if (len >= 3) {
-            array[2] = st.st_gid;
-        }
-    }
-    env->ReleasePrimitiveArrayCritical(outArray, array, 0);
-    return 0;
-}
-
 jint android_os_FileUtils_setUMask(JNIEnv* env, jobject clazz, jint mask)
 {
     return umask(mask);
@@ -158,7 +125,6 @@ jboolean android_os_FileUtils_getFileStatus(JNIEnv* env, jobject clazz, jstring
 
 static const JNINativeMethod methods[] = {
     {"setPermissions",  "(Ljava/lang/String;III)I", (void*)android_os_FileUtils_setPermissions},
-    {"getPermissions",  "(Ljava/lang/String;[I)I", (void*)android_os_FileUtils_getPermissions},
     {"setUMask",        "(I)I",                    (void*)android_os_FileUtils_setUMask},
     {"getFatVolumeId",  "(Ljava/lang/String;)I", (void*)android_os_FileUtils_getFatVolumeId},
     {"getFileStatusNative", "(Ljava/lang/String;Landroid/os/FileUtils$FileStatus;)Z", (void*)android_os_FileUtils_getFileStatus},

services/java/com/android/server/pm/PackageManagerService.java

@@ -144,6 +144,7 @@
 import libcore.io.ErrnoException;
 import libcore.io.IoUtils;
 import libcore.io.Libcore;
+import libcore.io.StructStat;
 
 /**
  * Keep track of all those .apks everywhere.
@@ -294,8 +295,6 @@ public class PackageManagerService extends IPackageManager.Stub {
     File mScanningPath;
     int mLastScanError;
 
-    final int[] mOutPermissions = new int[3];
-
     // ----------------------------------------------------------------
 
     // Keys are String (package name), values are Package.  This also serves
@@ -3762,14 +3761,18 @@ private PackageParser.Package scanPackageLI(PackageParser.Package pkg,
             boolean uidError = false;
 
             if (dataPath.exists()) {
-                // XXX should really do this check for each user.
-                mOutPermissions[1] = 0;
-                FileUtils.getPermissions(dataPath.getPath(), mOutPermissions);
+                int currentUid = 0;
+                try {
+                    StructStat stat = Libcore.os.stat(dataPath.getPath());
+                    currentUid = stat.st_uid;
+                } catch (ErrnoException e) {
+                    Slog.e(TAG, "Couldn't stat path " + dataPath.getPath(), e);
+                }
 
                 // If we have mismatched owners for the data path, we have a problem.
-                if (mOutPermissions[1] != pkg.applicationInfo.uid) {
+                if (currentUid != pkg.applicationInfo.uid) {
                     boolean recovered = false;
-                    if (mOutPermissions[1] == 0) {
+                    if (currentUid == 0) {
                         // The directory somehow became owned by root.  Wow.
                         // This is probably because the system was stopped while
                         // installd was in the middle of messing with its libs
@@ -3798,7 +3801,7 @@ private PackageParser.Package scanPackageLI(PackageParser.Package pkg,
                                     ? "System package " : "Third party package ";
                             String msg = prefix + pkg.packageName
                                     + " has changed from uid: "
-                                    + mOutPermissions[1] + " to "
+                                    + currentUid + " to "
                                     + pkg.applicationInfo.uid + "; old data erased";
                             reportSettingsProblem(Log.WARN, msg);
                             recovered = true;
@@ -3830,11 +3833,11 @@ private PackageParser.Package scanPackageLI(PackageParser.Package pkg,
                     if (!recovered) {
                         pkg.applicationInfo.dataDir = "/mismatched_uid/settings_"
                             + pkg.applicationInfo.uid + "/fs_"
-                            + mOutPermissions[1];
+                            + currentUid;
                         pkg.applicationInfo.nativeLibraryDir = pkg.applicationInfo.dataDir;
                         String msg = "Package " + pkg.packageName
                                 + " has mismatched uid: "
-                                + mOutPermissions[1] + " on disk, "
+                                + currentUid + " on disk, "
                                 + pkg.applicationInfo.uid + " in settings";
                         // writer
                         synchronized (mPackages) {