The GPFS SEEK_HOLE bug appears to have been fixed by IBM a few years ago, as reported here:
https://www.spectrumscale.org/pipermail/gpfsug-discuss/2018-February/004595.html https://www.spectrumscale.org/pipermail/gpfsug-discuss/2018-February/004596.html https://www-01.ibm.com/support/docview.wss?uid=isg1IV87385 so I am closing the grep bug report.
