Merge "Explicitly cast to 64bit integer when calculating filesystem size" am: 10a8797ce0 am: 83f5476b3d

Original change: https://android-review.googlesource.com/c/platform/system/core/+/1586546

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: Ibe4b041bf28881c21a683ca6d9c42944e098c928
diff --git a/fs_mgr/fs_mgr_overlayfs.cpp b/fs_mgr/fs_mgr_overlayfs.cpp
index cdbadc9..1134f14 100644
--- a/fs_mgr/fs_mgr_overlayfs.cpp
+++ b/fs_mgr/fs_mgr_overlayfs.cpp
@@ -194,7 +194,7 @@
     static constexpr unsigned long kSizeThreshold = 8 * 1024 * 1024;  // 8MB
 
     return (vst.f_bfree >= (vst.f_blocks * kPercentThreshold / 100)) &&
-           (vst.f_bfree * vst.f_bsize) >= kSizeThreshold;
+           (static_cast<uint64_t>(vst.f_bfree) * vst.f_frsize) >= kSizeThreshold;
 }
 
 const auto kPhysicalDevice = "/dev/block/by-name/"s;