CI: reorganize overlayfs CI

Fix some CI complaint and reorganize CI workflows.

Signed-off-by: Wei Zhang <weizhang555.zw@gmail.com>

.github/workflows/xfstests.yml

@@ -43,12 +43,12 @@ jobs:
         profile: minimal
         toolchain: stable
         override: true
-    - name: Build and testoverlay binary
+    - name: Build overlay binary
       run: |
-        cd tests/testoverlay
+        cd tests/overlay
         cargo build --release
-        sudo install -t /usr/sbin/ -m 700 ./target/release/testoverlay
+        sudo install -t /usr/sbin/ -m 700 ./target/release/overlay
     - name: Setup and run xfstest
       run: |
         cd $GITHUB_WORKSPACE
-        sudo ./tests/scripts/xfstests.sh
+        sudo ./tests/scripts/xfstests_overlay.sh

src/api/filesystem/mod.rs

@@ -30,7 +30,9 @@ pub use async_io::{AsyncFileSystem, AsyncZeroCopyReader, AsyncZeroCopyWriter};
 mod sync_io;
 pub use sync_io::FileSystem;
 
+#[cfg(all(any(feature = "fusedev", feature = "virtiofs"), target_os = "linux"))]
 mod overlay;
+#[cfg(all(any(feature = "fusedev", feature = "virtiofs"), target_os = "linux"))]
 pub use overlay::Layer;
 
 /// Information about a path in the filesystem.