Re: [PATCH v1 1/2] vfs: Add new setgid_create_umask test

[Christian Brauner <brauner@kernel.org>]

On Mon, Jul 25, 2022 at 07:55:23AM +0000, xuyang2018.jy@fujitsu.com wrote:
> 
> on  2022/05/21 0:04, Yang Xu wrote:
> > The current_umask() is stripped from the mode directly in the vfs if the
> > filesystem either doesn't support acls or the filesystem has been
> > mounted without posic acl support.
> > 
> > If the filesystem does support acls then current_umask() stripping is
> > deferred to posix_acl_create(). So when the filesystem calls
> > posix_acl_create() and there are no acls set or not supported then
> > current_umask() will be stripped.
> > 
> > This patch is also designed to test kernel patchset behaviour
> > "move S_ISGID stripping into the vfs"
> > https://patchwork.kernel.org/project/linux-fsdevel/list/?series=635692
> 
> The kernel patch has been merged into linux-next branch[1].
> 
> Does anyone review this fstests patch or give some comment?
> 
> I plan to remove setgid_create_umask_idmapped_in_userns and 
> setgid_create_umask_idmapped cases because they doesn't trigger bug.
> 
> Just treat it  as a kernel regression test ie 31c01ce18 ("generic: add 
> test for tmpfs POSIX ACLs") format.
> 
> CC Christian to confirm that whether need to test idmapped and 
> idmapped_in_userbs situation .

You've also sent a patch to LTP I saw which is good. I'm not completely
sure why you want to remove setgid_create_umask_idmapped{_in_userns}.
But as long as we have tests for setgid stripping on idmapped mounts I'm
fine with this.

Christian