Re: [PATCH 2/4] generic: ensure we drop suid after fallocate

[Eryu Guan <guan@eryu.me>]

On Fri, Apr 15, 2022 at 04:42:33PM +0300, Amir Goldstein wrote:
> > Hi Darrick, that's another story, you don't need to worry about that in this case :)
> > I'd like to ack this patch, but hope to move it from generic/ to shared/ . Maybe
> > Eryu can help to move it, or I can do that after I get the push permission.
> >
> > The reason why I intend moving it to shared is:
> > Although we are trying to get rid of tests/shared/, but the tests/shared/ still help to
> > remind us what cases are still not real generic cases. We'll try to help all shared
> > cases to be generic. When the time is ready, I'd like to move this case to generic/
> > and change _supported_fs from "xfs btrfs ext4" to "generic".
> >
> 
> Sorry, but I have to object to this move.
> I do not think that is what tests/shared should be used for.

After reading all the discussions, I prefer option 2 here as well, it's
testing for a security bug, and all affected filesystems should be fixed,
and a new failure will remind people there's something to be fixed.

> 
> My preferences are:
> 1. _suppoted_fs generic && _require_xfs_io_command "finsert"

As btrfs doesn't support "finsert", so the falloc/fpunch tests won't run
on btrfs, and we miss test coverage there.

> 2. _suppoted_fs generic
> 3. _supported_fs xfs btrfs ext4 (without moving to tests/shared)

This is weired. And if we really want to restrict the new behavior
within xfs, btrfs and ext4 for now, then I can live with a whitelist
_require rule, and a good comment on it.

Thanks,
Eryu