Re: sysfs: tagged directories not merged completely yet

[Greg KH <greg@kroah.com>]

On Tue, Oct 07, 2008 at 05:54:24PM -0500, Serge E. Hallyn wrote:
> Quoting Greg KH (greg@kroah.com):
> > On Tue, Oct 07, 2008 at 01:27:17AM -0700, Eric W. Biederman wrote:
> > > Unless someone will give an example of how having multiple superblocks
> > > sharing inodes is a problem in practice for sysfs and call it good
> > > for 2.6.28.  Certainly it shouldn't be an issue if the network namespace
> > > code is compiled out.  And it should greatly improve testing of the
> > > network namespace to at least have access to sysfs.
> > 
> > But if the network namespace code is in?  THen we have problems, right?
> > And that's the whole point here.
> > 
> > The fact that you are trying to limit userspace view of in-kernel data
> > structures, based on that specific user, is, in my opinion, crazy.
> > 
> > Why not just keep all users from seeing sysfs, and then have a user
> > daemon doing something on top of FUSE if you really want to see this
> > kind of stuff.
> 
> Well the blocker is really that when you create a new network namespace,
> it wants to create a new loopback interface, but
> /sys/devices/virtual/net/lo already exists.  That's the same issue with
> user namespace when the fair scheduler is enabled, which tries to
> re-create /sys/kernel/uids/0.
> 
> Otherwise yeah at least for my own uses, containers wouldn't need to
> look at /sys at all.
> 
> Heck you wouldn't even need FUSE, just mount -t tmpfs /sys/class/net
> and manually link the right devices from /sys/devices/virtual/net.

Great, that sounds like a solution.

So tell me again why we need these huge sysfs reworks? :)

thanks,

greg k-h