scille / winfsp_wrs

WinFSP wrapper for Rust

Winfsp Wrapper Rust

Requirements

WinFSP must be installed:

choco install winfsp

Run example

cargo run -p memfs my-mountpoint

Testing

Download winfsp-tests: https://github.com/winfsp/winfsp/releases/

winfsp-tests itself depends on WinFSP's DLL, hence the easiest way to avoid troubles is to put the winfsp-tests executable in the C:/Program Files (x86)/WinFsp/bin/ install folder (the alternative being to copy C:/Program Files (x86)/WinFsp/bin/winfsp-x64.dll in the directory where winfsp-tests executable resides).

Re-generate WinFSP bindgen code

(This is only needed when WinFSP headers change)

Rust bindgen CLI must be installed

cargo install bindgen-cli

On top of that, Clang is needed by rust-bindgen for parsing WinFSP C++ API headers.

To install Clang (also see rust-bindgen doc):

winget install LLVM.LLVM
set LIBCLANG_PATH="C:\Program Files\LLVM\bin"

Then to re-generate:

python scripts/generate_bindgen.py  winfsp_wrs_sys/src/gen.rs

winfsp_wrs's Issues

Return error instead of silent cutoff when configuring too long prefix/file_system_name

winfsp_wrs/winfsp_wrs/src/file_system.rs

Lines 252 to 260 in add48f9

	pub fn set_prefix(&mut self, val: &U16CStr) -> &mut Self {
	let len = std::cmp::min(self.0.Prefix.len(), val.len());
	self.0.Prefix[..len].copy_from_slice(&val.as_slice()[..len]);
	self
	}
	pub fn set_file_system_name(&mut self, val: &U16CStr) -> &mut Self {
	let len = std::cmp::min(self.0.FileSystemName.len(), val.len());

Would be better to return a Return<&mut Self, &mut Self> so that the caller is informed of the issue

Notes:

• no actual error type is needed given there is only one error reason and it is obvious)
• error returns the object so that the caller can then recover from the error and continue the configuration

Is `init` idempotent ?

winfsp_wrs/winfsp_wrs/src/init.rs

Lines 52 to 64 in add48f9

	/// This function is needed to initialize `WinFSP`.
	/// You should also add `winfsp_build::build()` in your `build.rs` to allow
	/// delayload, which is needed because `winfsp_wrs` depends on `WinFSP's dll`
	/// which is not in Windows path or at the same location of your binary.
	pub fn init() -> Result<(), u32> {
	unsafe {
	if LoadLibraryW(get_lplibfilename()?.as_ptr().cast_mut()) == 0 {
	Err(ERROR_DELAY_LOAD_FAILED)
	} else {
	Ok(())
	}
	}
	}

Currently it's unclear what happen if init is called multiple times, so we should:

• ensure it is fine to call it multiple times
• add a comment to the docstring (something like This function is idempotent, hence calling it multiple times is safe.
• add a test (typically call 3 times init, then mount and do an access on the mountpoint)