diff --git a/apkdmverity/src/main.rs b/apkdmverity/src/main.rs
index d9e9e2b..2901304 100644
--- a/apkdmverity/src/main.rs
+++ b/apkdmverity/src/main.rs
@@ -108,8 +108,10 @@
             bail!("The size of {:?} is not multiple of {}.", &apk, BLOCK_SIZE)
         }
         (
-            loopdevice::attach(&apk, 0, apk_size, /*direct_io*/ true, /*writable*/ false)
-                .context("Failed to attach APK to a loop device")?,
+            loopdevice::attach(
+                &apk, 0, apk_size, /* direct_io */ true, /* writable */ false,
+            )
+            .context("Failed to attach APK to a loop device")?,
             apk_size,
         )
     };
@@ -123,9 +125,10 @@
     // Due to unknown reason(b/191344832), we can't enable "direct IO" for the IDSIG file (backing
     // the hash). For now we don't use "direct IO" but it seems OK since the IDSIG file is very
     // small and the benefit of direct-IO would be negliable.
-    let hash_device =
-        loopdevice::attach(&idsig, offset, size, /*direct_io*/ false, /*writable*/ false)
-            .context("Failed to attach idsig to a loop device")?;
+    let hash_device = loopdevice::attach(
+        &idsig, offset, size, /* direct_io */ false, /* writable */ false,
+    )
+    .context("Failed to attach idsig to a loop device")?;
 
     // Build a dm-verity target spec from the information from the idsig file. The apk and the
     // idsig files are used as the data device and the hash device, respectively.
@@ -338,7 +341,7 @@
         // of the data device is done in the scopeguard for the return value of `enable_verity`
         // below. Only the idsig_loop_device needs detatching.
         let apk_loop_device = loopdevice::attach(
-            &apk_path, 0, apk_size, /*direct_io*/ true, /*writable*/ false,
+            &apk_path, 0, apk_size, /* direct_io */ true, /* writable */ false,
         )
         .unwrap();
         let idsig_loop_device = scopeguard::guard(
@@ -346,8 +349,8 @@
                 &idsig_path,
                 0,
                 idsig_size,
-                /*direct_io*/ false,
-                /*writable*/ false,
+                /* direct_io */ false,
+                /* writable */ false,
             )
             .unwrap(),
             |dev| loopdevice::detach(dev).unwrap(),