From mboxrd@z Thu Jan 1 00:00:00 1970 From: Aristeu Rozanski Subject: Re: [PATCH RESEND 0/4] device_cgroup: replace internally whitelist with exception list Date: Thu, 16 Aug 2012 16:49:13 -0400 Message-ID: <20120816204913.GG28505@cathedrallabs.org> References: <20120809190414.773462171@muttley.lan.cathedral> <20120816130844.6f26530d.akpm@linux-foundation.org> Mime-Version: 1.0 Return-path: Content-Disposition: inline In-Reply-To: <20120816130844.6f26530d.akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org> Sender: cgroups-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Andrew Morton Cc: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Tejun Heo , Li Zefan On Thu, Aug 16, 2012 at 01:08:44PM -0700, Andrew Morton wrote: > On Thu, 09 Aug 2012 15:04:14 -0400 > aris-moeOTchvdi7YtjvyW6yDsg@public.gmane.org wrote: > > > The original model of device_cgroup is having a whitelist where all the > > allowed devices are listed. The problem with this approach is that is > > impossible to have the case of allowing everything but few devices. > > > > The reason for that lies in the way the whitelist is handled internally: > > since there's only a whitelist, the "all devices" entry would have to be > > removed and replaced by the entire list of possible devices but the ones > > that are being denied. Since dev_t is 32 bits long, representing the allowed > > devices as a bitfield is not memory efficient. > > > > This patch replaces the "whitelist" by a "exceptions" list and the default > > policy is kept as "deny_all" variable in dev_cgroup structure. > > The patches look reasonable to me. I suggest you resend them after > kernel summit and cc a few additional people: Serge Hallyn, Pavel > Emelyanov and James Morris. thanks, will do. will include the checkpatch fixes as well. -- Aristeu