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From:   Miklos Szeredi <miklos@szeredi.hu>
Date:   Mon, 18 Sep 2023 16:51:03 +0200
Message-ID: <CAJfpegvxNhty2xZW+4MM9Gepotii3CD1p0fyvLDQB82hCYzfLQ@mail.gmail.com>
Subject: Re: [RFC PATCH 2/3] add statmnt(2) syscall
To:     Christian Brauner <brauner@kernel.org>
Cc:     Miklos Szeredi <mszeredi@redhat.com>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-api@vger.kernel.org, linux-man@vger.kernel.org,
        linux-security-module@vger.kernel.org, Karel Zak <kzak@redhat.com>,
        Ian Kent <raven@themaw.net>,
        David Howells <dhowells@redhat.com>,
        Al Viro <viro@zeniv.linux.org.uk>,
        Christian Brauner <christian@brauner.io>,
        Amir Goldstein <amir73il@gmail.com>
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On Mon, 18 Sept 2023 at 16:40, Christian Brauner <brauner@kernel.org> wrote:

> What we're talking about here is a nicely typed struct which returns two
> paths @mnt_root and @mnt_point which can both be represented as u64
> pointers with length parameters like we do in other binary structs such
> as bpf and clone3 and a few others. That is a compromise I can live
> with. I'm really trying to find as much common ground here as we can.

So to be clear about your proposal: .mnt_root and .mountpoint are
initialized by the caller to buffers that the kernel can copy paths
into?

If there's an overflow (one of the buffers was too small) the syscall
returns -EOVERFLOW?

Thanks,
Miklos