On Thu, Apr 15, 2021 at 07:54:08AM +0200, Christoph Hellwig wrote: > On Wed, Apr 14, 2021 at 04:47:10PM -0400, Theodore Ts'o wrote: > > On Mon, Apr 12, 2021 at 06:41:20PM -0400, Theodore Ts'o wrote: > > > In the ideal world, if the kernel wasn't compiled with the necessary > > > CONFIG options enabled, it's desirable of the test can detect that > > > fact and skip running the test instead failing and forcing the person > > > running the test to try to figure out whether this is a legitmate file > > > system bug or a just a test setup bug. > > > > So it would make it easier for me to manage running xfstests on ext4 > > if I had added something like this to ext4 and sent it to Linus before > > v5.12 is released. What do folks think? > > Completely stupid. This is a VFS-level feature and we need to have > proper VFS-level testing (which we have through creating a mount > with the option), not fs-specific band aids. Harsh words. :) Christoph's right though I think for the xfstests we don't need it and we're covered with what we have in the version I sent out last Sunday. However, as a general way of advertising to users that ext4 supports idmapped mounts I don't necessarily see a problem with that. It doesn't have implications for other filesystems and ext4 already advertises other features in a similar way. Christian