Skip the OFD locks tests on OverlayFS

Cargo.toml

@@ -16,7 +16,7 @@ exclude     = [
 ]
 
 [dependencies]
-libc = { git = "https://github.com/rust-lang/libc/", features = [ "extra_traits" ] }
+libc = { git = "https://github.com/asomers/libc/", rev = "6f3ffc9bf8d2f4a8569db765c4b0623e90c8babf", features = [ "extra_traits" ] }
 bitflags = "1.1"
 cfg-if = "0.1.10"
 void = "1.0.2"

src/sys/statfs.rs

@@ -75,6 +75,8 @@ pub const NFS_SUPER_MAGIC: FsType = FsType(libc::NFS_SUPER_MAGIC);
 #[cfg(all(target_os = "linux", not(target_env = "musl"), not(target_arch = "s390x")))]
 pub const OPENPROM_SUPER_MAGIC: FsType = FsType(libc::OPENPROM_SUPER_MAGIC);
 #[cfg(all(target_os = "linux", not(target_env = "musl"), not(target_arch = "s390x")))]
+pub const OVERLAYFS_SUPER_MAGIC: FsType = FsType(libc::OVERLAYFS_SUPER_MAGIC);
+#[cfg(all(target_os = "linux", not(target_env = "musl"), not(target_arch = "s390x")))]
 pub const PROC_SUPER_MAGIC: FsType = FsType(libc::PROC_SUPER_MAGIC);
 #[cfg(all(target_os = "linux", not(target_env = "musl"), not(target_arch = "s390x")))]
 pub const QNX4_SUPER_MAGIC: FsType = FsType(libc::QNX4_SUPER_MAGIC);

test/test_fcntl.rs

@@ -219,6 +219,13 @@ mod linux_android {
         let tmp = NamedTempFile::new().unwrap();
 
         let fd = tmp.as_raw_fd();
+        let statfs = nix::sys::statfs::fstatfs(&tmp).unwrap();
+        if statfs.filesystem_type() == nix::sys::statfs::OVERLAYFS_SUPER_MAGIC {
+            // OverlayFS is a union file system.  It returns one inode value in
+            // stat(2), but a different one shows up in /proc/locks.  So we must
+            // skip the test.
+            skip!("/proc/locks does not work on overlayfs");
+        }
         let inode = fstat(fd).expect("fstat failed").st_ino as usize;
 
         let mut flock = libc::flock {
@@ -256,6 +263,12 @@ mod linux_android {
 
         println!("TMPDIR is {:?}", std::env::var("TMPDIR"));
         let statfs = nix::sys::statfs::fstatfs(&tmp).unwrap();
+        if statfs.filesystem_type() == nix::sys::statfs::OVERLAYFS_SUPER_MAGIC {
+            // OverlayFS is a union file system.  It returns one inode value in
+            // stat(2), but a different one shows up in /proc/locks.  So we must
+            // skip the test.
+            skip!("/proc/locks does not work on overlayfs");
+        }
         println!("fd fstatfs is {:?}", statfs);
         println!("fd fstatfs.filesystem_type() is {:?}", statfs.filesystem_type());