api2/tape/backup: add 'force-media-set' parameter to manual backup

so that a user can force a new media set, e.g. if he uses the
allocation policy 'continue', but wants to manually start a new
media-set.

Signed-off-by: Dominik Csapak <d.csapak@proxmox.com>

src/api2/tape/backup.rs

@@ -226,6 +226,7 @@ pub fn do_tape_backup_job(
                     &setup,
                     email.clone(),
                     &mut summary,
+                    false,
                 )
             });
 
@@ -312,6 +313,12 @@ pub fn run_tape_backup_job(
                 type: TapeBackupJobSetup,
                 flatten: true,
             },
+            "force-media-set": {
+                description: "Ignore the allocation policy and start a new media-set.",
+                optional: true,
+                type: bool,
+                default: false,
+            },
         },
     },
     returns: {
@@ -327,6 +334,7 @@ pub fn run_tape_backup_job(
 /// Backup datastore to tape media pool
 pub fn backup(
     setup: TapeBackupJobSetup,
+    force_media_set: bool,
     rpcenv: &mut dyn RpcEnvironment,
 ) -> Result<Value, Error> {
 
@@ -373,6 +381,7 @@ pub fn backup(
                 &setup,
                 email.clone(),
                 &mut summary,
+                force_media_set,
             );
 
             if let Some(email) = email {
@@ -403,6 +412,7 @@ fn backup_worker(
     setup: &TapeBackupJobSetup,
     email: Option<String>,
     summary: &mut TapeBackupJobSummary,
+    force_media_set: bool,
 ) -> Result<(), Error> {
 
     let status_path = Path::new(TAPE_STATUS_DIR);
@@ -413,7 +423,13 @@ fn backup_worker(
 
     let pool = MediaPool::with_config(status_path, &pool_config, changer_name, false)?;
 
-    let mut pool_writer = PoolWriter::new(pool, &setup.drive, worker, email)?;
+    let mut pool_writer = PoolWriter::new(
+        pool,
+        &setup.drive,
+        worker,
+        email,
+        force_media_set
+    )?;
 
     let mut group_list = BackupInfo::list_backup_groups(&datastore.base_path())?;
 

src/api2/tape/media.rs

@@ -129,7 +129,7 @@ pub async fn list_media(
         // Call start_write_session, so that we show the same status a
         // backup job would see.
         pool.force_media_availability();
-        pool.start_write_session(current_time)?;
+        pool.start_write_session(current_time, false)?;
 
         for media in pool.list_media() {
             let expired = pool.media_is_expired(&media, current_time);

src/tape/media_pool.rs

@@ -258,7 +258,7 @@ impl MediaPool {
     /// Make sure the current media set is usable for writing
     ///
     /// If not, starts a new media set. Also creates a new
-    /// set if media_set_policy implies it.
+    /// set if media_set_policy implies it, or if 'force' is true.
     ///
     /// Note: We also call this in list_media to compute correct media
     /// status, so this must not change persistent/saved state.
@@ -267,6 +267,7 @@ impl MediaPool {
     pub fn start_write_session(
         &mut self,
         current_time: i64,
+        force: bool,
     ) -> Result<Option<String>, Error> {
 
         let _pool_lock = if self.no_media_set_locking {
@@ -277,11 +278,15 @@ impl MediaPool {
 
         self.inventory.reload()?;
 
-        let mut create_new_set = match self.current_set_usable() {
+        let mut create_new_set = if force {
-             Err(err) => {
+            Some(String::from("forced"))
-                 Some(err.to_string())
+        } else {
-             }
+            match self.current_set_usable() {
-             Ok(_) => None,
+                Err(err) => {
+                    Some(err.to_string())
+                }
+                Ok(_) => None,
+            }
         };
 
         if create_new_set.is_none() {

src/tape/pool_writer/mod.rs

@@ -71,11 +71,12 @@ impl PoolWriter {
         drive_name: &str,
         worker: &WorkerTask,
         notify_email: Option<String>,
+        force_media_set: bool,
     ) -> Result<Self, Error> {
 
         let current_time = proxmox::tools::time::epoch_i64();
 
-        let new_media_set_reason = pool.start_write_session(current_time)?;
+        let new_media_set_reason = pool.start_write_session(current_time, force_media_set)?;
         if let Some(reason) = new_media_set_reason {
             task_log!(
                 worker,