btrfs 1.2.2

Interface for BTRFS ioctls etc
Documentation 
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use linux::imports::*;

// --------- high level wrapper

pub fn defragment_file <
	FilePathRef: AsRef <Path>
> (
	file_path: FilePathRef,
	extent_threshold: u32,
	compression_type: CompressionType,
	flush_to_disk: bool,
) -> Result <(), String> {

	let file_path =
		file_path.as_ref ();

	let file_descriptor =
		FileDescriptor::open (
			file_path,
			libc::O_RDONLY,
		).map_err (
			|error|

			format! (
				"Error opening file: {}",
				error)

		) ?;

	defragment_range (
		file_descriptor.get_value (),
		0,
		-1_i64 as u64,
		extent_threshold,
		compression_type,
		flush_to_disk,
	)

}

pub fn defragment_range (
	file_descriptor: libc::c_int,
	start: u64,
	len: u64,
	extent_threshold: u32,
	compression_type: CompressionType,
	flush_to_disk: bool,
) -> Result <(), String> {

	let defrag_range_args =
		IoctlDefragRangeArgs {
			start: start,
			len: len,
			flags: (
				if compression_type != CompressionType::None {
					DEFRAG_RANGE_COMPRESS
				} else { 0 }
			|
				if flush_to_disk {
					DEFRAG_RANGE_START_IO
				} else { 0 }
			),
			extent_thresh: extent_threshold,
			compress_type: compression_type.into (),
			unused_0: 0,
			unused_1: 0,
			unused_2: 0,
			unused_3: 0,
		};

	// call ioctl

	unsafe {

		ioctl_defrag_range (
			file_descriptor,
			& defrag_range_args as * const IoctlDefragRangeArgs,
		)

	}.map_err (
		|error|

		format! (
			"Defragment IOCTL returned {}",
			error)

	) ?;

	// return ok

	Ok (())

}

// ex: noet ts=4 filetype=rust