On Thu, Jun 18, 2026 at 11:28:15AM +0200, Pankaj Raghav (Samsung) wrote:

quoted

But I guess not unaligned FALLOC_FL_WRITE_ZEROES?

        -r readbdy: 4096 would make reads page aligned (default 1)
        -t truncbdy: 4096 would make truncates page aligned (default 1)
        -w writebdy: 4096 would make writes page aligned (default 1)

FALLOC_FL_WRITE_ZEROES comes under truncate. So I would assume we also
do that. That is how I also found the issue with offset > EOF. I will
take a look or else, I will add a test case to test this condition!

A targeted test using xfs_io that does FALLOC_FL_WRITE_ZEROES on an
unaligned range and then checks that the data around it is preserved
while the unaligned data in the range is zeroed would also be useful.