[PATCH proxmox-backup 1/6] datastore: propagate maintenance mode parse errors

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

Handle maintenance mode parse errors since they are no longer silently
mapped to None. That was problematic because during upgrades the older
version would have potentially ignored a newly introduced maintenance
mode.

Signed-off-by: Robert Obkircher <r.obkircher@proxmox.com>
---
 pbs-datastore/src/datastore.rs      | 17 ++++++++++++-----
 src/api2/admin/datastore.rs         |  2 +-
 src/server/metric_collection/mod.rs |  7 +++----
 3 files changed, 16 insertions(+), 10 deletions(-)

diff --git a/pbs-datastore/src/datastore.rs b/pbs-datastore/src/datastore.rs
index e2d1ae67c..da7eba80e 100644
--- a/pbs-datastore/src/datastore.rs
+++ b/pbs-datastore/src/datastore.rs
@@ -303,9 +303,16 @@ impl Drop for DataStore {
                 Ok((section_config, _gen)) => {
                     match section_config.lookup::<DataStoreConfig>("datastore", self.name()) {
                         // second check: check if maintenance mode requires closing FDs
-                        Ok(config) => config
-                            .get_maintenance_mode()
-                            .is_some_and(|m| m.clear_from_cache()),
+                        Ok(config) => match config.get_maintenance_mode() {
+                            Ok(m) => m.is_some_and(|m| m.clear_from_cache()),
+                            Err(err) => {
+                                log::warn!(
+                                    "DataStore::drop: datastore '{}' in unknown maintenance mode; evicting cached instance: {err}",
+                                    self.name()
+                                );
+                                true
+                            }
+                        },
                         Err(err) => {
                             // datastore removed from config; evict cached entry if available (without checking maintenance mode)
                             log::warn!(
@@ -576,7 +583,7 @@ impl DataStore {
         let (section_config, gen_num) = datastore_section_config_cached(true)?;
         let config: DataStoreConfig = section_config.lookup("datastore", lookup.name)?;
 
-        if let Some(maintenance_mode) = config.get_maintenance_mode() {
+        if let Some(maintenance_mode) = config.get_maintenance_mode()? {
             if let Err(error) = maintenance_mode.check(lookup.operation) {
                 bail!("datastore '{}' is unavailable: {error}", lookup.name);
             }
@@ -660,7 +667,7 @@ impl DataStore {
         let datastore: DataStoreConfig = config.lookup("datastore", name)?;
         if datastore
             .get_maintenance_mode()
-            .is_some_and(|m| m.clear_from_cache())
+            .map_or(true, |m| m.is_some_and(|m| m.clear_from_cache()))
         {
             // the datastore drop handler does the checking if tasks are running and clears the
             // cache entry, so we just have to trigger it here
diff --git a/src/api2/admin/datastore.rs b/src/api2/admin/datastore.rs
index 64c73ba06..94272c32d 100644
--- a/src/api2/admin/datastore.rs
+++ b/src/api2/admin/datastore.rs
@@ -2695,7 +2695,7 @@ fn expect_maintenance_type(
     let store_config: DataStoreConfig = section_config.lookup("datastore", store)?;
 
     if store_config
-        .get_maintenance_mode()
+        .get_maintenance_mode()?
         .is_none_or(|m| m.ty != maintenance_type)
     {
         bail!("maintenance mode is not '{maintenance_type}'");
diff --git a/src/server/metric_collection/mod.rs b/src/server/metric_collection/mod.rs
index 18625b1a5..299156f8e 100644
--- a/src/server/metric_collection/mod.rs
+++ b/src/server/metric_collection/mod.rs
@@ -286,10 +286,9 @@ fn collect_disk_stats_sync() -> (DiskStat, Vec<DatastoreStats>) {
                 .unwrap_or_default();
 
             for config in datastore_list {
-                if config
-                    .get_maintenance_mode()
-                    .is_some_and(|mode| mode.check(Operation::Read).is_err())
-                {
+                if config.get_maintenance_mode().map_or(true, |m| {
+                    m.is_some_and(|mode| mode.check(Operation::Read).is_err())
+                }) {
                     continue;
                 }
 
-- 
2.47.3