Re: [RFC] fstests: add mmap page boundary tests

[Luis Chamberlain <mcgrof@kernel.org>]

On Tue, May 28, 2024 at 03:18:03PM -0700, Luis Chamberlain wrote:
> On Mon, Apr 15, 2024 at 08:58:25AM -0700, Darrick J. Wong wrote:
> > On Mon, Apr 15, 2024 at 01:10:54AM -0700, Luis Chamberlain wrote:
> > > +	#    This is not true for tmpfs.
> > 
> > Er... is this file size change a bug?
> 
> There is no filesize bug, the comment about tmpfs always ensuring seeing
> the actual data since, well, there its kind of write-through. Since we
> share the same filemap_map_pages() I'd expect the rest should behave the
> same with tmpfs, but since I didn't test that the test skips it for now.
> 
> We'll test it, with all the patch "filemap: cap PTE range to be             
> created to allowed zero fill in folio_map_range()" on tmpfs, and see if
> we can just enable this test there too. Might as well as we're driving
> by and sprinkling large folios there too.

Turns out our patch "filemap: cap PTE range to be created to allowed
zero fill in folio_map_range()" ends up fixing this on tmpfs for huge
pages. So consider this now tested on tmpfs as well, I'll adjust the
test for that.

  Luis