zfs: Disallow block.* settings for regular custom block volumes

Fixes #12188

Signed-off-by: Thomas Hipp <[email protected]>

lxd/storage/drivers/driver_zfs_volumes.go

@@ -1525,7 +1525,15 @@ func (d *zfs) commonVolumeRules() map[string]func(value string) error {
 
 // ValidateVolume validates the supplied volume config.
 func (d *zfs) ValidateVolume(vol Volume, removeUnknownKeys bool) error {
-	return d.validateVolume(vol, d.commonVolumeRules(), removeUnknownKeys)
+	commonRules := d.commonVolumeRules()
+
+	// Disallow block.* settings for regular custom block volumes.
+	if vol.volType == VolumeTypeCustom && (vol.contentType == ContentTypeBlock || !vol.IsBlockBacked()) {
+		delete(commonRules, "block.filesystem")
+		delete(commonRules, "block.mount_options")
+	}
+
+	return d.validateVolume(vol, commonRules, removeUnknownKeys)
 }
 
 // UpdateVolume applies config changes to the volume.
@@ -3330,6 +3338,8 @@ func (d *zfs) FillVolumeConfig(vol Volume) error {
 	// If vol has a source, ignore the block mode related config keys from the pool.
 	if vol.hasSource || vol.IsVMBlock() {
 		excludedKeys = []string{"zfs.block_mode", "block.filesystem", "block.mount_options"}
+	} else if vol.volType == VolumeTypeCustom && (vol.contentType == ContentTypeBlock || !vol.IsBlockBacked()) {
+		excludedKeys = []string{"block.filesystem", "block.mount_options"}
 	}
 
 	err := d.fillVolumeConfig(&vol, excludedKeys...)