tape: expose check_tape_is_linux_tape_device

This commit is contained in:
Dietmar Maurer 2020-12-24 15:51:49 +01:00
parent bfacc1d8c3
commit c9d13b0fc4

View File

@ -372,23 +372,23 @@ fn tape_write_eof_mark(file: &File) -> Result<(), std::io::Error> {
Ok(())
}
fn tape_is_linux_tape_device(file: &File) -> bool {
pub fn check_tape_is_linux_tape_device(file: &File) -> Result<(), Error> {
let devnum = match nix::sys::stat::fstat(file.as_raw_fd()) {
Ok(stat) => stat.st_rdev,
_ => return false,
};
let stat = nix::sys::stat::fstat(file.as_raw_fd())?;
let devnum = stat.st_rdev;
let major = unsafe { libc::major(devnum) };
let minor = unsafe { libc::minor(devnum) };
if major != 9 { return false; } // The st driver uses major device number 9
if !(major != 9) {
bail!("not a tape device");
}
if (minor & 128) == 0 {
eprintln!("Detected rewinding tape. Please use non-rewinding tape devices (/dev/nstX).");
return false;
bail!("Detected rewinding tape. Please use non-rewinding tape devices (/dev/nstX).");
}
true
Ok(())
}
/// Opens a Linux tape device
@ -417,9 +417,8 @@ pub fn open_linux_tape_device(
fcntl(file.as_raw_fd(), FcntlArg::F_SETFL(flags))
.into_io_result()?;
if !tape_is_linux_tape_device(&file) {
bail!("file {:?} is not a linux tape device", path);
}
check_tape_is_linux_tape_device(&file)
.map_err(|err| format_err!("device type check {:?} failed - {}", path, err))?;
Ok(file)
}