From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Serge E. Hallyn" Subject: Re: [PATCH 1/8] kernfs: Add API to generate relative kernfs path Date: Mon, 30 Nov 2015 12:37:58 -0600 Message-ID: <20151130183758.GA25433@mail.hallyn.com> References: <1447703505-29672-1-git-send-email-serge@hallyn.com> <1447703505-29672-2-git-send-email-serge@hallyn.com> <20151124161630.GL17033@mtj.duckdns.org> <20151127052511.GA25490@mail.hallyn.com> <20151130151147.GG3535@mtj.duckdns.org> Mime-Version: 1.0 Return-path: Content-Disposition: inline In-Reply-To: <20151130151147.GG3535-qYNAdHglDFBN0TnZuCh8vA@public.gmane.org> Sender: cgroups-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Tejun Heo Cc: "Serge E. Hallyn" , serge-A9i7LUbDfNHQT0dZR+AlfA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, adityakali-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org, linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, lxc-devel-cunTk1MwBs9qMoObBWhMNEqPaTDuhLve2LY78lusg7I@public.gmane.org, akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org, ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org On Mon, Nov 30, 2015 at 10:11:47AM -0500, Tejun Heo wrote: > Hello, > > On Thu, Nov 26, 2015 at 11:25:11PM -0600, Serge E. Hallyn wrote: > > > > + /* Short-circuit the easy case - kn_to is the root node. */ > > > > + if ((kn_from == kn_to) || (!kn_from && !kn_to->parent)) { > > > > + *p = '/'; > > > > + *(p + 1) = '\0'; > > > > > > Hmm... so if kn_from == kn_to, the output is "/"? > > > > Yes, that's what seems to make the most sense for cgroup namespaces. I > > could see a case for '.' being used instead in general, but for cgroup > > namespaces I think we'd have to convert those back to '/'. Otherwise > > we'll fail in being able to run legacy software, which would get > > confused. > > Yeah, I agree but the name is kinda misleading tho. The output isn't > really a relative path but rather absolute path against the specified > root. Maybe updating the function and parameter names would be > helpful? > > Thanks. Ok - updating the comment is simple enough. Though the name/params kernfs_path_from_node_locked(from, to) still seem to make sense. Would you prefer something like kernfs_absolute_path_from node_locked()? I hesitate to call 'from' 'root' since kernfs_root is a thing and this is not that.