[Cluster-devel] RFC: use the iomap writepage path in gfs2

[Christoph Hellwig]

On Thu, Jul 04, 2019 at 12:35:41AM +0200, Andreas Gruenbacher wrote:
> Patch "gfs2: implement gfs2_block_zero_range using iomap_zero_range"
> isn't quite ready: the gfs2 iomap operations don't handle IOMAP_ZERO
> correctly so far, and that needs to be fixed first.

What is the issue with IOMAP_ZERO on gfs2?  Zeroing never does block
allocations except when on COW extents, which gfs2 doesn't support,
so there shouldn't really be any need for additional handling.

> Some of the tests assume that the filesystem supports unwritten
> extents, trusted xattrs, the usrquota / grpquota / prjquota mount
> options. There shouldn't be a huge number of failing tests beyond
> that, but I know things aren't perfect.

In general xfstests is supposed to have tests for that and not run
the tests if not supported.  In most cases this is automatic, but
in case a feature can't be autodetect we have a few manual overrides.