linstor: fix getVolumeStats if multiple Linstor primary storages are used (apache#11397)

We didn't account for caching the volume stats for each used Linstor
cluster, so the first asked Linstor cluster would prevent caching
for all the others and so null was returned.

Now we have invalidate counters for each Linstor cluster and
also store the cache result with the Linstor cluster address prefixed.

Author: rp-

plugins/storage/volume/linstor/CHANGELOG.md

@@ -5,6 +5,12 @@ All notable changes to Linstor CloudStack plugin will be documented in this file
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [2025-08-05]
+
+### Fixed
+
+- getVolumeStats wasn't correctly working if multiple Linstor clusters/primary storages are used.
+
 ## [2025-07-01]
 
 ### Fixed

plugins/storage/volume/linstor/src/main/java/org/apache/cloudstack/storage/datastore/driver/LinstorPrimaryDataStoreDriverImpl.java

@@ -137,7 +137,7 @@ public class LinstorPrimaryDataStoreDriverImpl implements PrimaryDataStoreDriver
     private HostDao _hostDao;
     @Inject private VMTemplateDao _vmTemplateDao;
 
-    private long volumeStatsLastUpdate = 0L;
+    private final Map<String, Long> volumeStatsLastUpdate = new HashMap<>();
     private final Map<String, Pair<Long, Long>> volumeStats = new HashMap<>();
 
     public LinstorPrimaryDataStoreDriverImpl()
@@ -1535,11 +1535,12 @@ public boolean canProvideVolumeStats() {
 
     /**
      * Updates the cache map containing current allocated size data.
-     * @param api Linstor Developers api object
+     * @param linstorAddr Linstor cluster api address
      */
-    private void fillVolumeStatsCache(DevelopersApi api) {
+    private void fillVolumeStatsCache(String linstorAddr) {
+        final DevelopersApi api = LinstorUtil.getLinstorAPI(linstorAddr);
         try {
-            s_logger.trace("Start volume stats cache update");
+            s_logger.trace("Start volume stats cache update for " + linstorAddr);
             List<ResourceWithVolumes> resources = api.viewResources(
                     Collections.emptyList(),
                     Collections.emptyList(),
@@ -1566,29 +1567,34 @@ private void fillVolumeStatsCache(DevelopersApi api) {
                 }
             }
 
-            volumeStats.clear();
+            volumeStats.keySet().removeIf(key -> key.startsWith(linstorAddr));
             for (Map.Entry<String, Long> entry : allocSizeMap.entrySet()) {
                 Long reserved = resSizeMap.getOrDefault(entry.getKey(), 0L);
                 Pair<Long, Long> volStat = new Pair<>(entry.getValue(), reserved);
-                volumeStats.put(entry.getKey(), volStat);
+                volumeStats.put(linstorAddr + "/" + entry.getKey(), volStat);
             }
-            volumeStatsLastUpdate = System.currentTimeMillis();
-            s_logger.trace("Done volume stats cache update: " + volumeStats.size());
+            volumeStatsLastUpdate.put(linstorAddr, System.currentTimeMillis());
+            s_logger.debug(String.format("Done volume stats cache update for %s: %d", linstorAddr, volumeStats.size()));
         } catch (ApiException e) {
             s_logger.error("Unable to fetch Linstor resources: " + e.getBestMessage());
         }
     }
 
     @Override
     public Pair<Long, Long> getVolumeStats(StoragePool storagePool, String volumeId) {
-        final DevelopersApi api = LinstorUtil.getLinstorAPI(storagePool.getHostAddress());
+        String linstorAddr = storagePool.getHostAddress();
         synchronized (volumeStats) {
-            long invalidateCacheTime = volumeStatsLastUpdate +
+            long invalidateCacheTime = volumeStatsLastUpdate.getOrDefault(storagePool.getHostAddress(), 0L) +
                     LinstorConfigurationManager.VolumeStatsCacheTime.value() * 1000;
             if (invalidateCacheTime < System.currentTimeMillis()) {
-                fillVolumeStatsCache(api);
+                fillVolumeStatsCache(storagePool.getHostAddress());
+            }
+            String volumeKey = linstorAddr + "/" + LinstorUtil.RSC_PREFIX + volumeId;
+            Pair<Long, Long> sizePair = volumeStats.get(volumeKey);
+            if (sizePair == null) {
+                s_logger.warn(String.format("Volumestats for %s not found in cache", volumeKey));
             }
-            return volumeStats.get(LinstorUtil.RSC_PREFIX + volumeId);
+            return sizePair;
         }
     }