Re: [PATCH] fs/namespace: correctly handle errors returned by grab_requested_mnt_ns

[Carlos Llamas <cmllamas@google.com>]

On Mon, Nov 24, 2025 at 11:14:46AM -0800, Andrei Vagin wrote:
> On Mon, Nov 24, 2025 at 3:23 AM Mark Brown <broonie@kernel.org> wrote:
> >
> > On Sun, Nov 23, 2025 at 07:15:16AM -0800, Andrei Vagin wrote:
> > > On Sun, Nov 23, 2025 at 4:51 AM Mark Brown <broonie@kernel.org> wrote:
> >
> > > > listmount04.c:128: TFAIL: invalid mnt_id_req.spare expected EINVAL: EBADF (9)
> >
> > > The merged patch is slightly different from what you can see on the
> > > mailing list, so it's better to look at commit 78f0e33cd6c93
> > > ("fs/namespace: correctly handle errors returned by
> > > grab_requested_mnt_ns") to understand what is going on here.
> >
> > > With this patch, the spare field can be used as the `mnt_ns_fd`. EINVAL
> > > is returned if both mnt_ns_fd and mnt_ns_id are set. A non-zero
> > > mnt_ns_fd (the old spare) is interpreted as a namespace file descriptor.
> >
> > I can see what's happening - the question is if the test failure it
> > triggers is a problem in the kernel or in the test.
> 
> This is a test problem. The test has to be modified to check cases when
> the target mount namespace is specified by mnt_fs_fd.

Cc: Andrea Cervesato <andrea.cervesato@suse.com>

Loop in Andrea (test owner) to possibly make the corresponding updates.

Thanks,
Carlos Llamas