Re: [RFC PATCH] getting misc stats/attributes via xattr API

From: Miklos Szeredi
Date: Tue May 10 2022 - 09:35:14 EST


On Tue, 10 May 2022 at 15:15, Miklos Szeredi <miklos@xxxxxxxxxx> wrote:
>
> On Tue, 10 May 2022 at 13:53, Christian Brauner <brauner@xxxxxxxxxx> wrote:
>
> > > What exactly are the attributes that systemd requires?
> >
> > We keep a repo with ideas for (kernel) extensions - we should probably
> > publish that somewhere - but the list we used for a prototype roughly
> > contains:
> >
> > * mount flags MOUNT_ATTR_RDONLY etc.
> > * time flags MOUNT_ATTR_RELATIME etc. (could probably be combined with
> > mount flags. We missed the opportunity to make them proper enums
> > separate from other mount flags imho.)
> > * propagation "flags" (MS_SHARED)
> > * peer group
> > * mnt_id of the mount
> > * mnt_id of the mount's parent
> > * owning userns
>
> Sounds good thus far. And hey, we don't even need a new syscall:
> statx(2) could handle these fine.

Oh, we need this indexed with a mount id, which statx can't do. So
indeed, a new syscall may be the best choice.

Thanks,
Miklos