On Mon, 16 Jun 2025 at 13:38, Al Viro <viro@xxxxxxxxxxxxxxxxxx> wrote:
>
> Folks, how much would you hate the following trick:
>
> lock_mount(path, &m) returning void, and indicating error by storing
> ERR_PTR(-E...) into m.path; unlock_mount(&m) doing nothing if IS_ERR(m.mp);
> users turned into
>
> scoped_guard(lock_mount, mp)(path) {
> if (IS_ERR(mp.mp))
> return ERR_PTR(mp.mp);
> ....
> }
Eww.
It feels like using 'scoped_cond_guard()' is the *much* more
appropriate model, even if that interface is kind of disgusting.
The it would literally become
scoped_cond_guard(lock_mount, return ERR_PTR(mp.mp), mp, path) {
except I do admit that our "cond" guard syntax is horribly nasty - see
the several threads people have had about trying to make them better.
You've been cc'd on at least some of them.
Maybe using lock_mount() could help figure out what the right syntax
for the conditional guards are.
Linus
