Messages in this thread | | | From | (Eric W. Biederman) | Date | Wed, 22 Oct 2008 14:01:59 -0700 | Subject | Re: [PATCH 0/4][RFC] netns: sysfs: add a netns suffix to net device sysfs entries |
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"Serge E. Hallyn" <serue@us.ibm.com> writes:
> Quoting Eric W. Biederman (ebiederm@xmission.com): >> Benjamin Thery <benjamin.thery@bull.net> writes: >> >> > Support for network namespaces in mainline is pretty complete for >> > some time now, but there is still this issue with sysfs that prevents >> > more people to use it easily. >> >> Ben your patchset is completely inappropriate. >> >> Temporarily adding elements to the ABI that we intend to remove >> is not a proper solution to this problem. >> >> That user space visible ida you add is a namespace identifier that breaks >> nested containers and migration. It is very very very wrong. > > I disagree (not surprising :) completely. The well-known userspace > tools (ifconfig, ip, etc) will not see the lo@1, they'll see lo. > Userspace in a container can either umount /sys completely, or do
The well-known user space tools don't use /sys at all. Modern network tools use rtnetlink (ip) old network tools use /proc/net.
Very few things actually use /sys and for those things lo@1 or eth0@1 are completely useless except for implementing a FUSE mock up of sysfs. But you don't need anything in sysfs to do that as all of the interesting information is available through /proc/net or rtnetlink.
> > mount -t tmpfs none /sys/class/net > mount --bind /sys/devices/virtual/net/lo@1 /sys/class/net/lo > > if they really want to, in which case only their view > of /sys/devices/virtual/net would be different. > > Eric, would you hate this less if it was under some > > CONFIG_SYSFS_NETNS_HACK > > config variable?
No. ABI decisions are almost certainly irreversible.
If we need an immediate hack please see the patch I sent in follow up. We can achieve everything Ben is doing by simply keeping virtual devices out of the kobject tree. Keeping them from showing up in sysfs.
Eric
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