Re: [PATCH v2] generic/795: add unaligned boundary test cases for WRITE_ZEROES

[Pankaj Raghav <pankaj.raghav@linux.dev>]

>> Unfortunately, I've found a bug in filefrag that causes delalloc extents
>> to be reported with a length of 0. This means this test case can miss
>> delalloc extents. The issue is in misc/filefrag.c's print_extent_info(),
>> where ext_len is incorrectly set to 0 for the FIEMAP_EXTENT_UNKNOWN or
>> EXT4_FIEMAP_EXTENT_HOLE cases. Could you please send a patch to fix this
>> as well?
> 
> We can't really rely on having a bleeding edge filefrag for xfstests
> (well, at least without a feature check for it, but even that
> would not a good usability story).  I guess at least for now
> we might have to add  a little tool that just calls FIEMAP for
> us to xfstests?
> 

What about adding an option to io/filemap.c to take a flag that allows calling
fiemap without FIEMAP_FLAG_SYNC? So this test could depend on xfs_io fiemap command
with the flag support enabled? I can revert this test to the previous version which uses
xfs io fiemap instead of filefrag.

--
Pankaj