Messages in this thread | | | Date | Wed, 13 Nov 2019 18:47:57 +1100 | From | Aleksa Sarai <> | Subject | Re: [PATCH v15 4/9] namei: LOOKUP_BENEATH: O_BENEATH-like scoped resolution |
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On 2019-11-13, Al Viro <viro@zeniv.linux.org.uk> wrote: > Minor nit here - I'd split "move the conditional call of set_root() > into nd_jump_root()" into a separate patch before that one. Makes > for fewer distractions in this one. I'd probably fold "and be > ready for errors other than -ECHILD" into the same preliminary > patch.
Will do.
> > + /* Not currently safe for scoped-lookups. */ > > + if (unlikely(nd->flags & LOOKUP_IS_SCOPED)) > > + return ERR_PTR(-EXDEV); > > Also a candidate for doing in nd_jump_link()... > > > @@ -1373,8 +1403,11 @@ static int follow_dotdot_rcu(struct nameidata *nd) > > struct inode *inode = nd->inode; > > > > while (1) { > > - if (path_equal(&nd->path, &nd->root)) > > + if (path_equal(&nd->path, &nd->root)) { > > + if (unlikely(nd->flags & LOOKUP_BENEATH)) > > + return -EXDEV; > > Umm... Are you sure it's not -ECHILD?
It wouldn't hurt to be -ECHILD -- though it's not clear to me how likely a success would be in REF-walk if the parent components didn't already trigger an unlazy_walk() in RCU-walk.
I guess that also means LOOKUP_NO_XDEV should trigger -ECHILD in follow_dotdot_rcu()?
-- Aleksa Sarai Senior Software Engineer (Containers) SUSE Linux GmbH <https://www.cyphar.com/> [unhandled content-type:application/pgp-signature] | |