Getting an error ' fsadm: Filesystem "swap" on device "/dev/mapper/rhel-swap" is not supported by this tool' while extending swap LV and it's filesystem.

Issue

• Unable to extend the swap filesystem
• Extending swap along with it's LV gives an error:

# lvextend -r -L +100M rhel/swap
  WARNING: Failed to connect to lvmetad. Falling back to device scanning.
fsadm: Filesystem "swap" on device "/dev/mapper/rhel-swap" is not supported by this tool.

# lvextend -r -L +100M rhel/swap
  Size of logical volume rhel/swap changed from <2.10 GiB (537 extents) to <2.20 GiB (562 extents).
  File system extend is not supported (swap).
  File system extend error.
  Logical volume rhel/swap successfully resized.