Revert "Revert "Compress .so files for PackageManager to reclaim the space""

This reverts commit ad0c6b5d8c.

Reason for revert: rolling forward the .so compression change. According to https://b.corp.google.com/issues/188859114#comment8, the underlying issue was fixed.

Bug: 254793035
Bug: 188859114
Fixes: 254793035
Fixes: 188859114

Change-Id: I4edc15d08527013206e3daf20c33ba29c87a01a2
Merged-In: I4edc15d08527013206e3daf20c33ba29c87a01a2

core/jni/com_android_internal_content_NativeLibraryHelper.cpp

@@ -22,6 +22,7 @@
 #include <errno.h>
 #include <fcntl.h>
 #include <inttypes.h>
+#include <linux/fs.h>
 #include <nativehelper/ScopedUtfChars.h>
 #include <stdlib.h>
 #include <string.h>
@@ -250,6 +251,16 @@ copyFileIfChanged(JNIEnv *env, void* arg, ZipFileRO* zipFile, ZipEntryRO zipEntr
         return INSTALL_FAILED_CONTAINER_ERROR;
     }
 
+    // If a filesystem like f2fs supports per-file compression, set the compression bit before data
+    // writes
+    unsigned int flags;
+    if (ioctl(fd, FS_IOC_GETFLAGS, &flags) == -1) {
+        ALOGE("Failed to call FS_IOC_GETFLAGS on %s: %s\n", localTmpFileName, strerror(errno));
+    } else if ((flags & FS_COMPR_FL) == 0) {
+        flags |= FS_COMPR_FL;
+        ioctl(fd, FS_IOC_SETFLAGS, &flags);
+    }
+
     if (!zipFile->uncompressEntry(zipEntry, fd)) {
         ALOGE("Failed uncompressing %s to %s\n", fileName, localTmpFileName);
         close(fd);