Lucid SRU - UBUNTU: SAUCE: netns: Add quota for number of NET_NS instances.

Tim Gardner tim.gardner at
Mon Dec 19 16:21:11 UTC 2011

On 12/19/2011 08:32 AM, Serge Hallyn wrote:
> Quoting Brad Figg (brad.figg at
>> On 12/01/2011 01:48 PM, Tim Gardner wrote:
>>> Please consider this (untested) patch for inclusion in Lucid. See the discussion in for arguments proposing to restore CONFIG_NET_NS.
>>> I'll post a test kernel to the bug in awhile.
>>> One of the issues I have with this patch is that it appears that any consumer of network name spaces will have to initially write a non-zero value to netns_max before _any_ name spaces can be successfully allocated. If copy_net_ns() fails in
>>> create_new_namespaces(), then it seems the whole allocation is buggered.
>>> rtg
>> Tim,
>> If you follow the thread that starts at:
>> you will see that Tetsuo actually proposed a modified
>> version of this patch:
> (Shouldn't used_netns_count default to 1?  :)
> It looks good, I'd only ask that a warning be printed, even if only
> printk_once(), when the limit is hit.  Otherwise we risk mysterious
> bugs reported against other software.
> Acked-by: Serge Hallyn<serge.hallyn at>
> thanks,
> -serge

Serge - How about this? Changes include a non-zero initial value for 
max_netns_count, and a printk_once() warning if the count is ever exceeded.

Tim Gardner tim.gardner at
-------------- next part --------------
A non-text attachment was scrubbed...
Name: 0001-UBUNTU-SAUCE-netns-Add-quota-for-number-of-NET_NS-in.patch
Type: text/x-patch
Size: 3097 bytes
Desc: not available
URL: <>

More information about the kernel-team mailing list