btrfs2 1.2.2

Interface for BTRFS ioctls etc | fork of the btrfs-crate containing fixes. Intent to yank crate once fixes are accepted upstream!
Documentation 
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//! This module contains an interface to the kernel's file system info
//! functionality.
//!
//! This includes information about the various backing devices and their usage.
//! This information is essential to detect when a BTRFS filesystem is reaching
//! capacity, and a high level of usage may indicate that a balance operation
//! is required.

use linux::imports::*;

// ---------- get filesystem info

pub fn get_filesystem_info (
	file_descriptor: libc::c_int,
) -> Result <FilesystemInfo, String> {

	// get filesystem info

	let mut c_fs_info_args =
		IoctlFsInfoArgs::new ();

	let get_fs_info_result =
		unsafe {

		ioctl_fs_info (
			file_descriptor,
			& mut c_fs_info_args as * mut IoctlFsInfoArgs)

	};

	if let Err(e) = get_fs_info_result {

		return Err (
			"Error getting btrfs filesystem information".to_string ()
		);

	}

	// return

	Ok (
		FilesystemInfo {

			max_id:
				c_fs_info_args.max_id,

			num_devices:
				c_fs_info_args.num_devices,

			filesystem_id:
				Uuid::from_bytes (
					& c_fs_info_args.filesystem_id,
				).unwrap (),

		}
	)

}

pub fn get_device_info (
	file_descriptor: libc::c_int,
	device_id: u64,
) -> Result <Option <DeviceInfo>, String> {

	let mut c_dev_info_args =
		IoctlDevInfoArgs::new ();

	c_dev_info_args.devid =
		device_id;

	let get_dev_info_result =
		unsafe {

		ioctl_dev_info (
			file_descriptor,
			& mut c_dev_info_args as * mut IoctlDevInfoArgs)

	};

	if let Err(e) = get_dev_info_result {

		match io::Error::last_os_error ().raw_os_error () {

			Some (libc::ENODEV) =>
				Ok (None),

			Some (errno) =>
				Err (
					format! (
						"Os error {} getting device info",
						errno)
				),

			None =>
				Err (
					"Unknown error getting device info".to_string (),
				),

		}

	} else {

		Ok (Some (
			DeviceInfo {

			device_id:
				c_dev_info_args.devid,

			uuid: Uuid::from_bytes (
				& c_dev_info_args.uuid,
			).unwrap (),

			bytes_used:
				c_dev_info_args.bytes_used,

			total_bytes:
				c_dev_info_args.total_bytes,

			path:
				c_dev_info_args.path.as_os_string (),

		}))

	}

}

pub fn get_device_infos (
	file_descriptor: libc::c_int,
	filesystem_info: & FilesystemInfo,
) -> Result <Vec <DeviceInfo>, String> {

	let mut device_infos: Vec <DeviceInfo> =
		vec! [];

	for device_id in 0 .. filesystem_info.max_id + 1 {

		let device_info_option =
			try! (
				get_device_info (
					file_descriptor,
					device_id));

		if device_info_option.is_none () {
			continue;
		}

		let device_info =
			device_info_option.unwrap ();

		device_infos.push (
			device_info);

	}

	Ok (device_infos)

}

// ex: noet ts=4 filetype=rust