Rust now integrated into bcachefs binary

Rust is now required for building the bcachefs tool, and rust code is
now fully integrated with the C codebase - meaning it is possible to
call back and forth.

The mount helper is now a subcommand, 'mount.bcachefs' is now a small
shell wrapper that invokes 'bcachefs mount'.

This will make it easier to start rewriting other subcommands in rust,
and eventually the whole command line interface.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

1 files changed, 33 insertions, 0 deletions

diff --git a/rust-src/src/lib.rs b/rust-src/src/lib.rs
new file mode 100644
index 00000000..b2f0aaa7
--- /dev/null
+++ b/rust-src/src/lib.rs
@@ -0,0 +1,33 @@
+pub mod filesystem;
+pub mod key;
+pub mod cmd_mount;
+
+pub mod err {
+    pub enum GError {
+        Unknown {
+            message: std::borrow::Cow<'static, String>,
+        },
+    }
+    pub type GResult<T, E, OE> = ::core::result::Result<::core::result::Result<T, E>, OE>;
+    pub type Result<T, E> = GResult<T, E, GError>;
+}
+
+#[macro_export]
+macro_rules! c_str {
+    ($lit:expr) => {
+        unsafe {
+            std::ffi::CStr::from_ptr(concat!($lit, "\0").as_ptr() as *const std::os::raw::c_char)
+                .to_bytes_with_nul()
+                .as_ptr() as *const std::os::raw::c_char
+        }
+    };
+}
+
+#[derive(Debug)]
+struct ErrnoError(errno::Errno);
+impl std::fmt::Display for ErrnoError {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> Result<(), std::fmt::Error> {
+        self.0.fmt(f)
+    }
+}
+impl std::error::Error for ErrnoError {}