OS-1566 filesystem limits for ZFS datasets

*** 1263,1272 ****
--- 1263,1282 ----
                      (prop == ZFS_PROP_QUOTA || prop == ZFS_PROP_REFQUOTA)) {
                          zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                              "use 'none' to disable quota/refquota"));
                          goto error;
                  }
+ 
+                 /*
+                  * Special handling for "*_limit=none". In this case it's not
+                  * 0 but UINT64_MAX.
+                  */
+                 if ((type & ZFS_TYPE_DATASET) && isnone &&
+                     (prop == ZFS_PROP_FILESYSTEM_LIMIT ||
+                     prop == ZFS_PROP_SNAPSHOT_LIMIT)) {
+                         *ivalp = UINT64_MAX;
+                 }
                  break;
  
          case PROP_TYPE_INDEX:
                  if (datatype != DATA_TYPE_STRING) {
                          zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,