tape: do not abort backup if tape drive does not support tape-alert-flags

src/tape/drive/linux_tape.rs

@@ -70,6 +70,7 @@ impl LinuxTapeDrive {
     /// - for autoloader only, try to reload ejected tapes
     pub fn open(&self) -> Result<LinuxTapeHandle, Error> {
 
+        proxmox::try_block!({
             let file = open_linux_tape_device(&self.path)?;
 
             let mut handle = LinuxTapeHandle::new(file);
@@ -106,6 +107,7 @@ impl LinuxTapeDrive {
             // handle.set_default_options()?;
 
             Ok(handle)
+        }).map_err(|err| format_err!("open drive '{}' ({}) failed - {}", self.name, self.path, err))
     }
 }
 

src/tape/pool_writer.rs

@@ -214,13 +214,14 @@ impl PoolWriter {
             request_and_load_media(worker, &drive_config, &self.drive_name, media.label())?;
 
         // test for critical tape alert flags
-        let alert_flags = drive.tape_alert_flags()?;
+        if let Ok(alert_flags) = drive.tape_alert_flags() {
             if !alert_flags.is_empty() {
                 worker.log(format!("TapeAlertFlags: {:?}", alert_flags));
                 if tape_alert_flags_critical(alert_flags) {
                     bail!("aborting due to critical tape alert flags: {:?}", alert_flags);
                 }
             }
+        }
 
         let catalog = update_media_set_label(
             worker,