util: add GetCephFSRadosNamespace method

This commit adds `GetCephFSRadosNamespace` util method that returns
the `RadosNamespace` specified in ceph-csi-config ConfigMap under
cephFS.radosNamespace.

If not specified, the method returns the default RadosNamespace
i.e, csi.

Signed-off-by: Praveen M <m.praveen@ibm.com>

deploy/csi-config-map-sample.yaml

@@ -32,6 +32,11 @@ kind: ConfigMap
 # The "cephFS.fuseMountOptions" fields are common separated mount options
 # for `Ceph FUSE driver`. Setting this will override the fusemountoptions
 # command line flag.
+# The "cephFS.radosNamespace" is optional and represents a radosNamespace in the
+# metadata pool. If any given, the omap data of cephFS will be stored within
+# this radosNamespace.
+# NOTE: Make sure you don't add radosNamespace option to a currently in use
+# configuration as it will cause issues.
 # network namespace specified by the "cephFS.netNamespaceFilePath".
 # The "nfs.netNamespaceFilePath" fields are the various network namespace
 # path for the Ceph cluster identified by the <cluster-id>, This will be used
@@ -78,7 +83,8 @@ data:
           "subvolumeGroup": "<subvolumegroup for cephFS volumes>"
           "netNamespaceFilePath": "<kubeletRootPath>/plugins/cephfs.csi.ceph.com/net",
           "kernelMountOptions": "<kernelMountOptions for cephFS volumes>",
-          "fuseMountOptions": "<fuseMountOptions for cephFS volumes>"
+          "fuseMountOptions": "<fuseMountOptions for cephFS volumes>",
+          "radosNamespace": "<rados-namespace>"
         }
         "nfs": {
           "netNamespaceFilePath": "<kubeletRootPath>/plugins/nfs.csi.ceph.com/net",

internal/rbd/group/util.go

@@ -74,7 +74,7 @@ func (cvg *commonVolumeGroup) initCommonVolumeGroup(
 		return fmt.Errorf("failed to get MONs for cluster id %q: %w", csiID.ClusterID, err)
 	}
 
-	namespace, err := util.GetRadosNamespace(util.CsiConfigFile, csiID.ClusterID)
+	namespace, err := util.GetRBDRadosNamespace(util.CsiConfigFile, csiID.ClusterID)
 	if err != nil {
 		return fmt.Errorf("failed to get RADOS namespace for cluster id %q: %w", csiID.ClusterID, err)
 	}

internal/rbd/manager.go

@@ -97,7 +97,7 @@ func (mgr *rbdManager) getVolumeGroupJournal(clusterID string) (journal.VolumeGr
 		return nil, fmt.Errorf("failed to find MONs for cluster %q: %w", clusterID, err)
 	}
 
-	ns, err := util.GetRadosNamespace(util.CsiConfigFile, clusterID)
+	ns, err := util.GetRBDRadosNamespace(util.CsiConfigFile, clusterID)
 	if err != nil {
 		return nil, fmt.Errorf("failed to find the RADOS namespace for cluster %q: %w", clusterID, err)
 	}

internal/rbd/rbd_util.go

@@ -1023,7 +1023,7 @@ func genSnapFromSnapID(
 	}
 	rbdSnap.JournalPool = rbdSnap.Pool
 
-	rbdSnap.RadosNamespace, err = util.GetRadosNamespace(util.CsiConfigFile, rbdSnap.ClusterID)
+	rbdSnap.RadosNamespace, err = util.GetRBDRadosNamespace(util.CsiConfigFile, rbdSnap.ClusterID)
 	if err != nil {
 		return nil, err
 	}
@@ -1134,7 +1134,7 @@ func generateVolumeFromVolumeID(
 		return rbdVol, err
 	}
 
-	rbdVol.RadosNamespace, err = util.GetRadosNamespace(util.CsiConfigFile, rbdVol.ClusterID)
+	rbdVol.RadosNamespace, err = util.GetRBDRadosNamespace(util.CsiConfigFile, rbdVol.ClusterID)
 	if err != nil {
 		return rbdVol, err
 	}
@@ -1357,7 +1357,7 @@ func genVolFromVolumeOptions(
 		return nil, err
 	}
 
-	rbdVol.RadosNamespace, err = util.GetRadosNamespace(util.CsiConfigFile, rbdVol.ClusterID)
+	rbdVol.RadosNamespace, err = util.GetRBDRadosNamespace(util.CsiConfigFile, rbdVol.ClusterID)
 	if err != nil {
 		return nil, err
 	}

internal/util/csiconfig.go

@@ -31,6 +31,10 @@ const (
 	// This was hardcoded once and defaults to the old value to keep backward compatibility.
 	defaultCsiSubvolumeGroup = "csi"
 
+	// defaultCsiCephFSRadosNamespace defines the default RADOS namespace used for storing
+	// CSI-specific objects and keys for CephFS volumes.
+	defaultCsiCephFSRadosNamespace = "csi"
+
 	// CsiConfigFile is the location of the CSI config file.
 	CsiConfigFile = "/etc/ceph-csi-config/config.json"
 
@@ -96,8 +100,8 @@ func Mons(pathToConfig, clusterID string) (string, error) {
 	return strings.Join(cluster.Monitors, ","), nil
 }
 
-// GetRadosNamespace returns the namespace for the given clusterID.
+// GetRBDRadosNamespace returns the namespace for the given clusterID.
-func GetRadosNamespace(pathToConfig, clusterID string) (string, error) {
+func GetRBDRadosNamespace(pathToConfig, clusterID string) (string, error) {
 	cluster, err := readClusterInfo(pathToConfig, clusterID)
 	if err != nil {
 		return "", err
@@ -106,6 +110,21 @@ func GetRadosNamespace(pathToConfig, clusterID string) (string, error) {
 	return cluster.RBD.RadosNamespace, nil
 }
 
+// GetCephFSRadosNamespace returns the namespace for the given clusterID.
+// If not set, it returns the default value "csi".
+func GetCephFSRadosNamespace(pathToConfig, clusterID string) (string, error) {
+	cluster, err := readClusterInfo(pathToConfig, clusterID)
+	if err != nil {
+		return "", err
+	}
+
+	if cluster.CephFS.RadosNamespace == "" {
+		return defaultCsiCephFSRadosNamespace, nil
+	}
+
+	return cluster.CephFS.RadosNamespace, nil
+}
+
 // GetRBDMirrorDaemonCount returns the number of mirror daemon count for the
 // given clusterID.
 func GetRBDMirrorDaemonCount(pathToConfig, clusterID string) (int, error) {