lxd/storage/drivers/zfs: filter redundant options on `ensureInitialDa…

…tasets`

Signed-off-by: hamistao <pedro.ribeiro@canonical.com>

lxd/storage/drivers/driver_zfs.go

@@ -144,19 +144,26 @@ func (d zfs) ensureInitialDatasets(warnOnExistingPolicyApplyError bool) error {
 		args = append(args, fmt.Sprintf("%s=%s", k, v))
 	}
 
-	err := d.setDatasetProperties(d.config["zfs.pool_name"], args...)
+	args, err := d.filterRedundantOptions(d.config["zfs.pool_name"], args...)
 	if err != nil {
-		if warnOnExistingPolicyApplyError {
+		return err
+	}
+
+	if len(args) > 0 {
+		err := d.setDatasetProperties(d.config["zfs.pool_name"], args...)
+		if err != nil {
+			if !warnOnExistingPolicyApplyError {
+				return fmt.Errorf("Failed applying policy to existing dataset %q: %w", d.config["zfs.pool_name"], err)
+			}
+
 			d.logger.Warn("Failed applying policy to existing dataset", logger.Ctx{"dataset": d.config["zfs.pool_name"], "err": err})
-		} else {
-			return fmt.Errorf("Failed applying policy to existing dataset %q: %w", d.config["zfs.pool_name"], err)
 		}
 	}
 
 	for _, dataset := range d.initialDatasets() {
-		properties := []string{"mountpoint=legacy"}
+		args := []string{"mountpoint=legacy"}
 		if shared.ValueInSlice(dataset, []string{"virtual-machines", "deleted/virtual-machines"}) {
-			properties = append(properties, "volmode=none")
+			args = append(args, "volmode=none")
 		}
 
 		datasetPath := filepath.Join(d.config["zfs.pool_name"], dataset)
@@ -166,16 +173,23 @@ func (d zfs) ensureInitialDatasets(warnOnExistingPolicyApplyError bool) error {
 		}
 
 		if exists {
-			err = d.setDatasetProperties(datasetPath, properties...)
+			args, err = d.filterRedundantOptions(datasetPath, args...)
 			if err != nil {
-				if warnOnExistingPolicyApplyError {
+				return err
+			}
+
+			if len(args) > 0 {
+				err = d.setDatasetProperties(datasetPath, args...)
+				if err != nil {
+					if !warnOnExistingPolicyApplyError {
+						return fmt.Errorf("Failed applying policy to existing dataset %q: %w", datasetPath, err)
+					}
+
 					d.logger.Warn("Failed applying policy to existing dataset", logger.Ctx{"dataset": datasetPath, "err": err})
-				} else {
-					return fmt.Errorf("Failed applying policy to existing dataset %q: %w", datasetPath, err)
 				}
 			}
 		} else {
-			err = d.createDataset(datasetPath, properties...)
+			err = d.createDataset(datasetPath, args...)
 			if err != nil {
 				return fmt.Errorf("Failed creating dataset %q: %w", datasetPath, err)
 			}

lxd/storage/drivers/driver_zfs_utils.go

@@ -194,6 +194,44 @@ func (d *zfs) getDatasets(dataset string, types string) ([]string, error) {
 	return children, nil
 }
 
+// filterRedundantOptions filters out options for setting dataset properties that match with the values already set.
+func (d *zfs) filterRedundantOptions(dataset string, options ...string) ([]string, error) {
+	var keys, values []string
+
+	// Extract keys and values from options.
+	for _, option := range options {
+		property := strings.Split(option, "=")
+
+		if len(property) != 2 {
+			return nil, fmt.Errorf("Wrongly formatted option %q", option)
+		}
+
+		keys = append(keys, property[0])
+		values = append(values, property[1])
+	}
+
+	// Get current values for the keys.
+	currentProperties, err := d.getDatasetProperties(dataset, keys...)
+	if err != nil {
+		return nil, err
+	}
+
+	var resultantOptions []string
+
+	// Change property values that are different from the current value.
+	for propertyIndex := range keys {
+		if currentProperties[keys[propertyIndex]] == "posix" && values[propertyIndex] == "posixacl" { // "posixacl" is an alias for "posix"
+			continue
+		}
+
+		if currentProperties[keys[propertyIndex]] != values[propertyIndex] {
+			resultantOptions = append(resultantOptions, options[propertyIndex])
+		}
+	}
+
+	return resultantOptions, nil
+}
+
 func (d *zfs) setDatasetProperties(dataset string, options ...string) error {
 	args := []string{"set"}
 	args = append(args, options...)