thin-provisioning-tools/src/file_utils.rs

72 lines
1.8 KiB
Rust

use nix::sys::stat;
use nix::sys::stat::{FileStat, SFlag};
use std::io;
use std::fs::File;
use std::os::unix::io::AsRawFd;
//---------------------------------------
fn check_bits(mode: u32, flag: &SFlag) -> bool {
(mode & flag.bits()) != 0
}
pub fn is_file_or_blk(info: FileStat) -> bool {
check_bits(info.st_mode, &stat::SFlag::S_IFBLK) ||
check_bits(info.st_mode, &stat::SFlag::S_IFREG)
}
pub fn file_exists(path: &str) -> bool {
match stat::stat(path) {
Ok(info) => {
is_file_or_blk(info)
}
_ => {
// FIXME: assuming all errors indicate the file doesn't
// exist.
false
}
}
}
//---------------------------------------
const BLKGETSIZE64_CODE: u8 = 0x12;
const BLKGETSIZE64_SEQ: u8 = 114;
ioctl_read!(ioctl_blkgetsize64, BLKGETSIZE64_CODE, BLKGETSIZE64_SEQ, u64);
pub fn fail<T>(msg: &str) -> io::Result<T> {
let e = io::Error::new(io::ErrorKind::Other, msg);
Err(e)
}
fn get_device_size(path: &str) -> io::Result<u64> {
let file = File::open(path)?;
let fd = file.as_raw_fd();
let mut cap = 0u64;
unsafe {
match ioctl_blkgetsize64(fd, &mut cap) {
Ok(_) => {Ok(cap)}
_ => {fail("BLKGETSIZE64 ioctl failed")}
}
}
}
pub fn file_size(path: &str) -> io::Result<u64> {
match stat::stat(path) {
Ok(info) => {
if check_bits(info.st_mode, &SFlag::S_IFREG) {
Ok(info.st_size as u64)
} else if check_bits(info.st_mode, &SFlag::S_IFBLK) {
get_device_size(path)
} else {
fail("not a regular file or block device")
}
}
_ => {
fail("stat failed")
}
}
}
//---------------------------------------