[PATCH proxmox 2/3] pbs-abi-types: add GarbageCollection maintenance mode

[Robert Obkircher <r.obkircher@proxmox.com>]

This mode may be used to safely prune and garbage collect a datastore
without the risk of running out of space due to new backups.

Signed-off-by: Robert Obkircher <r.obkircher@proxmox.com>
---
 pbs-api-types/src/datastore.rs   | 1 +
 pbs-api-types/src/maintenance.rs | 8 ++++----
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/pbs-api-types/src/datastore.rs b/pbs-api-types/src/datastore.rs
index 098d2b7c..47ae1819 100644
--- a/pbs-api-types/src/datastore.rs
+++ b/pbs-api-types/src/datastore.rs
@@ -635,6 +635,7 @@ impl DataStoreConfig {
 
         match current_type {
             Some(MaintenanceType::ReadOnly) => { /* always OK  */ }
+            Some(MaintenanceType::GarbageCollection) => { /* always OK  */ }
             Some(MaintenanceType::Offline) => { /* always OK  */ }
             Some(MaintenanceType::Unmount) => {
                 /* used to reset it after failed unmount, or alternative for aborting unmount task */
diff --git a/pbs-api-types/src/maintenance.rs b/pbs-api-types/src/maintenance.rs
index 8a37756a..a46764bc 100644
--- a/pbs-api-types/src/maintenance.rs
+++ b/pbs-api-types/src/maintenance.rs
@@ -42,12 +42,10 @@ pub enum Operation {
 #[serde(rename_all = "kebab-case")]
 /// Maintenance type.
 pub enum MaintenanceType {
-    // TODO:
-    //  - Add "GarbageCollection" or "DeleteOnly" as type and track GC (or all deletes) as separate
-    //    operation, so that one can enable a mode where nothing new can be added but stuff can be
-    //    cleaned
     /// Only read operations are allowed on the datastore.
     ReadOnly,
+    /// Allow reads and reclaim operations, but no new writes.
+    GarbageCollection,
     /// Neither read nor write operations are allowed on the datastore.
     Offline,
     /// The datastore is being deleted.
@@ -116,6 +114,8 @@ impl MaintenanceMode {
             && matches!(operation, Operation::Write | Operation::Reclaim)
         {
             bail!("read-only maintenance mode: {}", message);
+        } else if self.ty == MaintenanceType::GarbageCollection && operation == Operation::Write {
+            bail!("garbage-collection maintenance mode: {}", message);
         }
         Ok(())
     }
-- 
2.47.3