tape: add fsf/bsf to TapeDriver trait

This commit is contained in:
Dietmar Maurer 2021-03-25 10:10:16 +01:00
parent 0320deb0a9
commit 589c4dad9e
4 changed files with 64 additions and 39 deletions

View File

@ -180,7 +180,7 @@ fn get_tape_handle(param: &Value) -> Result<LinuxTapeHandle, Error> {
///
/// Positioning is done by first rewinding the tape and then spacing
/// forward over count file marks.
fn asf(count: i32, param: Value) -> Result<(), Error> {
fn asf(count: usize, param: Value) -> Result<(), Error> {
let mut handle = get_tape_handle(&param)?;
@ -212,7 +212,7 @@ fn asf(count: i32, param: Value) -> Result<(), Error> {
/// Backward space count files (position before file mark).
///
/// The tape is positioned on the last block of the previous file.
fn bsf(count: i32, param: Value) -> Result<(), Error> {
fn bsf(count: usize, param: Value) -> Result<(), Error> {
let mut handle = get_tape_handle(&param)?;
@ -478,7 +478,7 @@ fn erase(fast: Option<bool>, param: Value) -> Result<(), Error> {
/// Forward space count files (position after file mark).
///
/// The tape is positioned on the first block of the next file.
fn fsf(count: i32, param: Value) -> Result<(), Error> {
fn fsf(count: usize, param: Value) -> Result<(), Error> {
let mut handle = get_tape_handle(&param)?;

View File

@ -242,32 +242,6 @@ impl LinuxTapeHandle {
Ok(())
}
pub fn forward_space_count_files(&mut self, count: i32) -> Result<(), Error> {
let cmd = mtop { mt_op: MTCmd::MTFSF, mt_count: count, };
unsafe {
mtioctop(self.file.as_raw_fd(), &cmd)
}.map_err(|err| {
format_err!("forward space {} files failed - {}", count, err)
})?;
Ok(())
}
pub fn backward_space_count_files(&mut self, count: i32) -> Result<(), Error> {
let cmd = mtop { mt_op: MTCmd::MTBSF, mt_count: count, };
unsafe {
mtioctop(self.file.as_raw_fd(), &cmd)
}.map_err(|err| {
format_err!("backward space {} files failed - {}", count, err)
})?;
Ok(())
}
/// Set tape compression feature
pub fn set_compression(&self, on: bool) -> Result<(), Error> {
@ -467,19 +441,28 @@ impl TapeDriver for LinuxTapeHandle {
Ok(())
}
fn move_to_last_file(&mut self) -> Result<(), Error> {
fn forward_space_count_files(&mut self, count: usize) -> Result<(), Error> {
let cmd = mtop { mt_op: MTCmd::MTEOM, mt_count: 1, };
let cmd = mtop { mt_op: MTCmd::MTFSF, mt_count: i32::try_from(count)? };
unsafe {
mtioctop(self.file.as_raw_fd(), &cmd)
}.map_err(|err| format_err!("MTEOM failed - {}", err))?;
}.map_err(|err| {
format_err!("forward space {} files failed - {}", count, err)
})?;
let cmd = mtop { mt_op: MTCmd::MTBSFM, mt_count: 2, };
Ok(())
}
fn backward_space_count_files(&mut self, count: usize) -> Result<(), Error> {
let cmd = mtop { mt_op: MTCmd::MTBSF, mt_count: i32::try_from(count)? };
unsafe {
mtioctop(self.file.as_raw_fd(), &cmd)
}.map_err(|err| format_err!("MTBSFM failed - {}", err))?;
}.map_err(|err| {
format_err!("backward space {} files failed - {}", count, err)
})?;
Ok(())
}

View File

@ -88,7 +88,24 @@ pub trait TapeDriver {
fn move_to_eom(&mut self) -> Result<(), Error>;
/// Move to last file
fn move_to_last_file(&mut self) -> Result<(), Error>;
fn move_to_last_file(&mut self) -> Result<(), Error> {
self.move_to_eom()?;
if self.current_file_number()? == 0 {
bail!("move_to_last_file failed - media contains no data");
}
self.backward_space_count_files(2)?;
Ok(())
}
/// Forward space count files. The tape is positioned on the first block of the next file.
fn forward_space_count_files(&mut self, count: usize) -> Result<(), Error>;
/// Backward space count files. The tape is positioned on the last block of the previous file.
fn backward_space_count_files(&mut self, count: usize) -> Result<(), Error>;
/// Current file number
fn current_file_number(&mut self) -> Result<u64, Error>;

View File

@ -296,6 +296,7 @@ impl TapeDriver for VirtualTapeHandle {
.map_err(|err| io::Error::new(io::ErrorKind::Other, err.to_string()))?;
*pos = index.files;
self.store_status(&status)
.map_err(|err| io::Error::new(io::ErrorKind::Other, err.to_string()))?;
@ -305,7 +306,7 @@ impl TapeDriver for VirtualTapeHandle {
}
}
fn move_to_last_file(&mut self) -> Result<(), Error> {
fn forward_space_count_files(&mut self, count: usize) -> Result<(), Error> {
let mut status = self.load_status()?;
match status.current_tape {
Some(VirtualTapeStatus { ref name, ref mut pos }) => {
@ -313,11 +314,35 @@ impl TapeDriver for VirtualTapeHandle {
let index = self.load_tape_index(name)
.map_err(|err| io::Error::new(io::ErrorKind::Other, err.to_string()))?;
if index.files == 0 {
bail!("move_to_last_file failed - media contains no data");
let new_pos = *pos + count;
if new_pos <= index.files {
*pos = new_pos;
} else {
bail!("forward_space_count_files failed: move beyond EOT");
}
*pos = index.files - 1;
self.store_status(&status)
.map_err(|err| io::Error::new(io::ErrorKind::Other, err.to_string()))?;
Ok(())
}
None => bail!("drive is empty (no tape loaded)."),
}
}
fn backward_space_count_files(&mut self, count: usize) -> Result<(), Error> {
let mut status = self.load_status()?;
match status.current_tape {
Some(VirtualTapeStatus { ref name, ref mut pos }) => {
let index = self.load_tape_index(name)
.map_err(|err| io::Error::new(io::ErrorKind::Other, err.to_string()))?;
if count <= *pos {
*pos = *pos - count;
} else {
bail!("backward_space_count_files failed: move before BOT");
}
self.store_status(&status)
.map_err(|err| io::Error::new(io::ErrorKind::Other, err.to_string()))?;