linstor: implement storage and volume stats methods

Using storage stats not every agent has to query the controller
for current used and capacity storage.

Volume stats will show physical used size for thin volume in Cloudstack.
This volume stats are cached to not query the Linstor controller each
time a volume is asked for.

Author: rp-

plugins/storage/volume/linstor/CHANGELOG.md

@@ -5,6 +5,11 @@ 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).
 
+## [2025-05-07]
+
+### Added
+- Implemented storage/volume stats
+
 ## [2025-03-13]
 
 ### Fixed

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

@@ -28,11 +28,11 @@
 import com.linbit.linstor.api.model.ResourceDefinitionCloneRequest;
 import com.linbit.linstor.api.model.ResourceDefinitionCloneStarted;
 import com.linbit.linstor.api.model.ResourceDefinitionCreate;
-
 import com.linbit.linstor.api.model.ResourceDefinitionModify;
 import com.linbit.linstor.api.model.ResourceGroup;
 import com.linbit.linstor.api.model.ResourceGroupSpawn;
 import com.linbit.linstor.api.model.ResourceMakeAvailable;
+import com.linbit.linstor.api.model.ResourceWithVolumes;
 import com.linbit.linstor.api.model.Snapshot;
 import com.linbit.linstor.api.model.SnapshotRestore;
 import com.linbit.linstor.api.model.VolumeDefinition;
@@ -132,6 +132,9 @@ public class LinstorPrimaryDataStoreDriverImpl implements PrimaryDataStoreDriver
     @Inject
     private HostDao _hostDao;
 
+    private long volumeStatsLastUpdate = 0L;
+    private final Map<String, Pair<Long, Long>> volumeStats = new HashMap<>();
+
     public LinstorPrimaryDataStoreDriverImpl()
     {
     }
@@ -401,9 +404,9 @@ private void applyQoSSettings(StoragePoolVO storagePool, DevelopersApi api, Stri
         }
     }
 
-    private String getRscGrp(StoragePoolVO storagePoolVO) {
-        return storagePoolVO.getUserInfo() != null && !storagePoolVO.getUserInfo().isEmpty() ?
-            storagePoolVO.getUserInfo() : "DfltRscGrp";
+    private String getRscGrp(StoragePool storagePool) {
+        return storagePool.getUserInfo() != null && !storagePool.getUserInfo().isEmpty() ?
+            storagePool.getUserInfo() : "DfltRscGrp";
     }
 
     /**
@@ -1504,22 +1507,77 @@ public void takeSnapshot(SnapshotInfo snapshotInfo, AsyncCompletionCallback<Crea
 
     @Override
     public boolean canProvideStorageStats() {
-        return false;
+        return true;
     }
 
     @Override
     public Pair<Long, Long> getStorageStats(StoragePool storagePool) {
-        return null;
+        s_logger.debug(String.format("Requesting storage stats: %s", storagePool));
+        return LinstorUtil.getStorageStats(storagePool.getHostAddress(), getRscGrp(storagePool));
     }
 
     @Override
     public boolean canProvideVolumeStats() {
-        return false;
+        return LinstorConfigurationManager.VolumeStatsCacheTime.value() > 0;
+    }
+
+    /**
+     * Updates the cache map containing current allocated size data.
+     * @param api Linstor Developers api object
+     */
+    private void fillVolumeStatsCache(DevelopersApi api) {
+        try {
+            s_logger.trace("Start volume stats cache update");
+            List<ResourceWithVolumes> resources = api.viewResources(
+                    Collections.emptyList(),
+                    Collections.emptyList(),
+                    Collections.emptyList(),
+                    null,
+                    null,
+                    null);
+
+            List<ResourceDefinition> rscDfns = api.resourceDefinitionList(
+                    Collections.emptyList(), true, null, null, null);
+
+            HashMap<String, Long> resSizeMap = new HashMap<>();
+            for (ResourceDefinition rscDfn : rscDfns) {
+                if (CollectionUtils.isNotEmpty(rscDfn.getVolumeDefinitions())) {
+                    resSizeMap.put(rscDfn.getName(), rscDfn.getVolumeDefinitions().get(0).getSizeKib() * 1024);
+                }
+            }
+
+            HashMap<String, Long> allocSizeMap = new HashMap<>();
+            for (ResourceWithVolumes rsc : resources) {
+                if (!LinstorUtil.isRscDiskless(rsc) && !rsc.getVolumes().isEmpty()) {
+                    long allocatedBytes = allocSizeMap.getOrDefault(rsc.getName(), 0L);
+                    allocSizeMap.put(rsc.getName(), Math.max(allocatedBytes, rsc.getVolumes().get(0).getAllocatedSizeKib() * 1024));
+                }
+            }
+
+            volumeStats.clear();
+            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);
+            }
+            volumeStatsLastUpdate = System.currentTimeMillis();
+            s_logger.trace("Done volume stats cache update: " + 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) {
-        return null;
+        final DevelopersApi api = LinstorUtil.getLinstorAPI(storagePool.getHostAddress());
+        synchronized (volumeStats) {
+            long invalidateCacheTime = volumeStatsLastUpdate +
+                    LinstorConfigurationManager.VolumeStatsCacheTime.value() * 1000;
+            if (invalidateCacheTime < System.currentTimeMillis()) {
+                fillVolumeStatsCache(api);
+            }
+            return volumeStats.get(LinstorUtil.RSC_PREFIX + volumeId);
+        }
     }
 
     @Override

plugins/storage/volume/linstor/src/main/java/org/apache/cloudstack/storage/datastore/util/LinstorConfigurationManager.java

@@ -24,7 +24,14 @@ public class LinstorConfigurationManager implements Configurable
     public static final ConfigKey<Boolean> BackupSnapshots = new ConfigKey<>(Boolean.class, "lin.backup.snapshots", "Advanced", "true",
         "Backup Linstor primary storage snapshots to secondary storage (deleting ps snapshot)", true, ConfigKey.Scope.Global, null);
 
-    public static final ConfigKey<?>[] CONFIG_KEYS = new ConfigKey<?>[] { BackupSnapshots };
+    public static final ConfigKey<Integer> VolumeStatsCacheTime = new ConfigKey<>("Advanced", Integer.class,
+            "lin.volumes.stats.cachetime", "300",
+            "Cache time of volume stats for Linstor volumes. 0 to disable volume stats",
+            false);
+
+    public static final ConfigKey<?>[] CONFIG_KEYS = new ConfigKey<?>[] {
+            BackupSnapshots, VolumeStatsCacheTime
+    };
 
     @Override
     public String getConfigComponentName()

plugins/storage/volume/linstor/src/main/java/org/apache/cloudstack/storage/datastore/util/LinstorUtil.java

@@ -195,6 +195,30 @@ public static long getCapacityBytes(String linstorUrl, String rscGroupName) {
         }
     }
 
+    public static Pair<Long, Long> getStorageStats(String linstorUrl, String rscGroupName) {
+        DevelopersApi linstorApi = getLinstorAPI(linstorUrl);
+        try {
+            List<StoragePool> storagePools = LinstorUtil.getRscGroupStoragePools(linstorApi, rscGroupName);
+
+            long capacity = storagePools.stream()
+                    .filter(sp -> sp.getProviderKind() != ProviderKind.DISKLESS)
+                    .mapToLong(sp -> sp.getTotalCapacity() != null ? sp.getTotalCapacity() : 0L)
+                    .sum() * 1024;  // linstor uses kiB
+
+            long used = storagePools.stream()
+                    .filter(sp -> sp.getProviderKind() != ProviderKind.DISKLESS)
+                    .mapToLong(sp -> sp.getTotalCapacity() != null && sp.getFreeCapacity() != null ?
+                            sp.getTotalCapacity() - sp.getFreeCapacity() : 0L)
+                    .sum() * 1024; // linstor uses Kib
+            s_logger.debug(
+                    String.format("Linstor(%s;%s): storageStats -> %d/%d", linstorUrl, rscGroupName, capacity, used));
+            return new Pair<>(capacity, used);
+        } catch (ApiException apiEx) {
+            s_logger.error(apiEx.getMessage());
+            throw new CloudRuntimeException(apiEx.getBestMessage(), apiEx);
+        }
+    }
+
     /**
      * Check if any resource of the given name is InUse on any host.
      *
@@ -402,4 +426,8 @@ public static ResourceDefinition findResourceDefinition(DevelopersApi api, Strin
 
         return rd.orElseGet(() -> rdsStartingWith.get(0));
     }
+
+    public static boolean isRscDiskless(ResourceWithVolumes rsc) {
+        return rsc.getFlags() != null && rsc.getFlags().contains(ApiConsts.FLAG_DISKLESS);
+    }
 }