Address review comments

Author: gnufied

csi.proto

@@ -1070,9 +1070,9 @@ message ControllerExpandVolumeRequest {
   // Volume capability describing how the CO intends to use this volume.
   // This allows SP to determine if volume is being used as a block
   // device or mounted file system. For example - if volume is
-  // being used as a block device - the SP MAY choose to skip calling
-  // NodeExpandVolume on the node by setting node_expansion_required
-  // to false in ControllerExpandVolumeResponse.
+  // being used as a block device - the SP MAY set
+  // node_expansion_required to false in ControllerExpandVolumeResponse
+  // to skip invocation of NodeExpandVolume on the node by the CO.
   // This is an OPTIONAL field.
   VolumeCapability volume_capability = 4;
 }
@@ -1355,7 +1355,9 @@ message NodeExpandVolumeRequest {
   // This allows SP to determine if volume is being used as a block
   // device or mounted file system. For example - if volume is being
   // used as a block device the SP MAY choose to skip expanding the
-  // filesystem. If volume_capability is omitted the SP MAY determine
+  // filesystem in NodeExpandVolume implementation but still perform
+  // rest of the housekeeping needed for expanding the volume. If
+  // volume_capability is omitted the SP MAY determine
   // access_type from given volume_path for the volume and perform
   // node expansion. This is an OPTIONAL field.
   VolumeCapability volume_capability = 5;

lib/go/csi/csi.pb.go

@@ -1805,7 +1805,7 @@ This RPC allows the CO to expand the size of a volume.
 This call MAY be made by the CO during any time in the lifecycle of the volume after creation if plugin has `VolumeExpansion.ONLINE` capability.
 If plugin has `EXPAND_VOLUME` node capability, then `NodeExpandVolume` MUST be called after successful `ControllerExpandVolume` and `node_expansion_required` in `ControllerExpandVolumeResponse` is `true`.
 
-If specified the `volume_capability` in `ControllerExpandVolumeRequest` should be same as what CO would pass in `ControllerPublishVolumeRequest`.
+If specified, the `volume_capability` in `ControllerExpandVolumeRequest` should be same as what CO would pass in `ControllerPublishVolumeRequest`.
 
 If the plugin has only `VolumeExpansion.OFFLINE` expansion capability and volume is currently published or available on a node then `ControllerExpandVolume` MUST be called ONLY after either:
 - The plugin has controller `PUBLISH_UNPUBLISH_VOLUME` capability and `ControllerUnpublishVolume` has been invoked successfully.
@@ -1851,9 +1851,9 @@ message ControllerExpandVolumeRequest {
   // Volume capability describing how the CO intends to use this volume.
   // This allows SP to determine if volume is being used as a block
   // device or mounted file system. For example - if volume is
-  // being used as a block device - the SP MAY choose to skip calling
-  // NodeExpandVolume on the node by setting node_expansion_required
-  // to false in ControllerExpandVolumeResponse.
+  // being used as a block device - the SP MAY set
+  // node_expansion_required to false in ControllerExpandVolumeResponse
+  // to skip invocation of NodeExpandVolume on the node by the CO.
   // This is an OPTIONAL field.
   VolumeCapability volume_capability = 4;
 }
@@ -2394,7 +2394,9 @@ message NodeExpandVolumeRequest {
   // This allows SP to determine if volume is being used as a block
   // device or mounted file system. For example - if volume is being
   // used as a block device the SP MAY choose to skip expanding the
-  // filesystem. If volume_capability is omitted the SP MAY determine
+  // filesystem in NodeExpandVolume implementation but still perform
+  // rest of the housekeeping needed for expanding the volume. If
+  // volume_capability is omitted the SP MAY determine
   // access_type from given volume_path for the volume and perform
   // node expansion. This is an OPTIONAL field.
   VolumeCapability volume_capability = 5;