On Tue, Nov 02, 2021 at 11:11:02AM +0100, Daniel Borkmann wrote: > On 11/2/21 10:25 AM, Miklos Szeredi wrote: > > On Thu, 28 Oct 2021 at 11:48, Lorenz Bauer <lmb@xxxxxxxxxxxxxx> wrote: > > > > > > Allow atomic exchange via RENAME_EXCHANGE when using simple_rename. > > > This affects binderfs, ramfs, hubetlbfs and bpffs. > > > > Ramfs and hugetlbfs are generic enough; those seem safe. > > > > Binderfs: I have no idea what this does; binderfs_rename() should Fwiw, allows dynamic creation and removal of Android binder ipc devices. Each mount is a separate instance and it's mountable inside unprivileged containers. Since Android 12 default how binder devices are managed. Also makes it possibe to run Android in unprivileged containers. > > probably error out on RENAME_EXCHANGE for now, or an explicit ack from > > the maintainers. > > Thanks for the review, Miklos! Adding Christian to Cc wrt binderfs ... full context > for all patches: https://lore.kernel.org/bpf/20211028094724.59043-1-lmb@xxxxxxxxxxxxxx/ Yep, I saw that. Seems good. > probably error out on RENAME_EXCHANGE for now, or an explicit ack from > the maintainers. I don't think there is any issue in allowing binderfs to support this. Binderfs files are always device nodes. Allowing them to be atomically renamed shouldn't be a problem. So: Acked-by: Christian Brauner <christian.brauner@xxxxxxxxxx> Christian
