diff --git a/KeyUtil.cpp b/KeyUtil.cpp
index acc42db..582eea2 100644
--- a/KeyUtil.cpp
+++ b/KeyUtil.cpp
@@ -64,40 +64,37 @@
     }
 }
 
+static bool isFsKeyringSupportedImpl() {
+    android::base::unique_fd fd(open("/data", O_RDONLY | O_DIRECTORY | O_CLOEXEC));
+
+    // FS_IOC_ADD_ENCRYPTION_KEY with a NULL argument will fail with ENOTTY if
+    // the ioctl isn't supported.  Otherwise it will fail with another error
+    // code such as EFAULT.
+    //
+    // Note that there's no need to check for FS_IOC_REMOVE_ENCRYPTION_KEY,
+    // since it's guaranteed to be available if FS_IOC_ADD_ENCRYPTION_KEY is.
+    // There's also no need to check for support on external volumes separately
+    // from /data, since either the kernel supports the ioctls on all
+    // fscrypt-capable filesystems or it doesn't.
+    errno = 0;
+    (void)ioctl(fd, FS_IOC_ADD_ENCRYPTION_KEY, NULL);
+    if (errno == ENOTTY) {
+        LOG(INFO) << "Kernel doesn't support FS_IOC_ADD_ENCRYPTION_KEY.  Falling back to "
+                     "session keyring";
+        return false;
+    }
+    if (errno != EFAULT) {
+        PLOG(WARNING) << "Unexpected error from FS_IOC_ADD_ENCRYPTION_KEY";
+    }
+    LOG(DEBUG) << "Detected support for FS_IOC_ADD_ENCRYPTION_KEY";
+    android::base::SetProperty("ro.crypto.uses_fs_ioc_add_encryption_key", "true");
+    return true;
+}
+
 // Return true if the kernel supports the ioctls to add/remove fscrypt keys
 // directly to/from the filesystem.
 bool isFsKeyringSupported(void) {
-    static bool initialized = false;
-    static bool supported;
-
-    if (!initialized) {
-        android::base::unique_fd fd(open("/data", O_RDONLY | O_DIRECTORY | O_CLOEXEC));
-
-        // FS_IOC_ADD_ENCRYPTION_KEY with a NULL argument will fail with ENOTTY
-        // if the ioctl isn't supported.  Otherwise it will fail with another
-        // error code such as EFAULT.
-        errno = 0;
-        (void)ioctl(fd, FS_IOC_ADD_ENCRYPTION_KEY, NULL);
-        if (errno == ENOTTY) {
-            LOG(INFO) << "Kernel doesn't support FS_IOC_ADD_ENCRYPTION_KEY.  Falling back to "
-                         "session keyring";
-            supported = false;
-        } else {
-            if (errno != EFAULT) {
-                PLOG(WARNING) << "Unexpected error from FS_IOC_ADD_ENCRYPTION_KEY";
-            }
-            LOG(DEBUG) << "Detected support for FS_IOC_ADD_ENCRYPTION_KEY";
-            supported = true;
-            android::base::SetProperty("ro.crypto.uses_fs_ioc_add_encryption_key", "true");
-        }
-        // There's no need to check for FS_IOC_REMOVE_ENCRYPTION_KEY, since it's
-        // guaranteed to be available if FS_IOC_ADD_ENCRYPTION_KEY is.  There's
-        // also no need to check for support on external volumes separately from
-        // /data, since either the kernel supports the ioctls on all
-        // fscrypt-capable filesystems or it doesn't.
-
-        initialized = true;
-    }
+    static bool supported = isFsKeyringSupportedImpl();
     return supported;
 }