Re: [PATCH v5 bpf-next 0/5] bpf path iterator

[Mickaël Salaün]

On Fri, Jun 20, 2025 at 02:59:17PM -0700, Song Liu wrote:
> Hi Christian, Mickaël, and folks,
> 
> Could you please share your comments on this version? Does this
> look sane?

This looks good to me but we need to know what is the acceptable next
step to support RCU.  If we can go with another _rcu helper, I'm good
with the current approach, otherwise we need to figure out a way to
leverage the current helper to make it compatible with callers being in
a RCU read-side critical section while leveraging safe path walk (i.e.
several calls to path_walk_parent).

> 
> Thanks,
> Song
> 
> On Mon, Jun 16, 2025 at 11:11 PM Song Liu <song@xxxxxxxxxx> wrote:
> >
> > In security use cases, it is common to apply rules to VFS subtrees.
> > However, filtering files in a subtree is not straightforward [1].
> >
> > One solution to this problem is to start from a path and walk up the VFS
> > tree (towards the root). Among in-tree LSMs, Landlock uses this solution.
> >
> 
> [...]
>