Update wording for new files

Also relax NodeStageVolume and NodePublishVolume using same
volume_mount_group field

csi.proto

@@ -1226,13 +1226,15 @@ message NodeStageVolumeRequest {
   map<string, string> volume_context = 6;
 
   // If SP has VOLUME_MOUNT_GROUP node capability and CO provides
-  // this field then SP MUST ensure that volume is mounted with
-  // provided volume_mount_group and all files and directories
-  // within the volume are readable and writable by the provided
-  // volume_mount_group.
-  // The value of volume_mount_group should be group
-  // identifier (as determined by underlying operating system)
-  // which would be associated with workload that uses the volume.
+  // this field then SP MUST ensure that the volume_mount_group
+  // parameter is passed as the group identifier to the underlying
+  // operating system mount system call, with the understanding
+  // that the set of available mount call parameters and/or
+  // mount implementations may vary across operating systems.
+  // Additionally, new file and/or directory entries written to
+  // the underlying filesystem SHOULD be permission-labeled in such a
+  // manner, unless otherwise modified by a workload, that they are
+  // both readable and writable by said mount group identifier.
   // This is an OPTIONAL field.
   string volume_mount_group = 7;
 }
@@ -1307,23 +1309,24 @@ message NodePublishVolumeRequest {
   // volume identified by `volume_id`.
   map<string, string> volume_context = 8;
 
+
   // If SP has VOLUME_MOUNT_GROUP node capability and CO provides
-  // this field then SP MUST ensure that volume is mounted with
-  // provided volume_mount_group and all files and directories
-  // within the volume are readable and writable by the provided
-  // volume_mount_group.
-  // If NodeStageVolume was previously called with volume_mount_group
-  // CO MUST ensure that NodePublishVolume uses the same
-  // volume_mount_group for the same volume_id.
-  // If Plugin does not have `STAGE_UNSTAGE_VOLUME` capability the CO
-  // MAY call NodePublishVolume with different volume_mount_group and
-  // target_path for same volume_id.
-  // If a Plugin does not support multiple calls of NodePublishVolume
-  // with different volume_mount_group and target_path for same volume
-  // on same node - it MAY return FAILED_PRECONDITION error.
-  // The value of volume_mount_group should be group
-  // identifier (as determined by underlying operating system)
-  // which would be associated with workload that uses the volume.
+  // this field then SP MUST ensure that the volume_mount_group
+  // parameter is passed as the group identifier to the underlying
+  // operating system mount system call, with the understanding
+  // that the set of available mount call parameters and/or
+  // mount implementations may vary across operating systems.
+  // Additionally, new file and/or directory entries written to
+  // the underlying filesystem SHOULD be permission-labeled in such a
+  // manner, unless otherwise modified by a workload, that they are
+  // both readable and writable by said mount group identifier.
+  //
+  // If Plugin does not support NodePublishVolume with different
+  // volume_mount_group than the one used during NodeStageVolume
+  // then Plugin MAY return FAILED_PRECONDITION error.
+  // Similarly if SP does not support NodePublishVolume of same volume
+  // on same node but with different volume_mount_group it MAY return
+  // FAILED_PRECONDITION error.
   // This is an OPTIONAL field.
   string volume_mount_group = 9;
 }

spec.md

@@ -2093,13 +2093,15 @@ message NodeStageVolumeRequest {
   map<string, string> volume_context = 6;
 
   // If SP has VOLUME_MOUNT_GROUP node capability and CO provides
-  // this field then SP MUST ensure that volume is mounted with
-  // provided volume_mount_group and all files and directories
-  // within the volume are readable and writable by the provided
-  // volume_mount_group.
-  // The value of volume_mount_group should be group
-  // identifier (as determined by underlying operating system)
-  // which would be associated with workload that uses the volume.
+  // this field then SP MUST ensure that the volume_mount_group
+  // parameter is passed as the group identifier to the underlying
+  // operating system mount system call, with the understanding
+  // that the set of available mount call parameters and/or
+  // mount implementations may vary across operating systems.
+  // Additionally, new file and/or directory entries written to
+  // the underlying filesystem SHOULD be permission-labeled in such a
+  // manner, unless otherwise modified by a workload, that they are
+  // both readable and writable by said mount group identifier.
   // This is an OPTIONAL field.
   string volume_mount_group = 7;
 }
@@ -2256,23 +2258,24 @@ message NodePublishVolumeRequest {
   // volume identified by `volume_id`.
   map<string, string> volume_context = 8;
 
+
   // If SP has VOLUME_MOUNT_GROUP node capability and CO provides
-  // this field then SP MUST ensure that volume is mounted with
-  // provided volume_mount_group and all files and directories
-  // within the volume are readable and writable by the provided
-  // volume_mount_group.
-  // If NodeStageVolume was previously called with volume_mount_group
-  // CO MUST ensure that NodePublishVolume uses the same
-  // volume_mount_group for the same volume_id.
-  // If Plugin does not have `STAGE_UNSTAGE_VOLUME` capability the CO
-  // MAY call NodePublishVolume with different volume_mount_group and
-  // target_path for same volume_id.
-  // If a Plugin does not support multiple calls of NodePublishVolume
-  // with different volume_mount_group and target_path for same volume
-  // on same node - it MAY return FAILED_PRECONDITION error.
-  // The value of volume_mount_group should be group
-  // identifier (as determined by underlying operating system)
-  // which would be associated with workload that uses the volume.
+  // this field then SP MUST ensure that the volume_mount_group
+  // parameter is passed as the group identifier to the underlying
+  // operating system mount system call, with the understanding
+  // that the set of available mount call parameters and/or
+  // mount implementations may vary across operating systems.
+  // Additionally, new file and/or directory entries written to
+  // the underlying filesystem SHOULD be permission-labeled in such a
+  // manner, unless otherwise modified by a workload, that they are
+  // both readable and writable by said mount group identifier.
+  //
+  // If Plugin does not support NodePublishVolume with different
+  // volume_mount_group than the one used during NodeStageVolume
+  // then Plugin MAY return FAILED_PRECONDITION error.
+  // Similarly if SP does not support NodePublishVolume of same volume
+  // on same node but with different volume_mount_group it MAY return
+  // FAILED_PRECONDITION error.
   // This is an OPTIONAL field.
   string volume_mount_group = 9;
 }