Network namespace and bonding WARNING at fs/proc/generic.c remove_proc_entry

[Eric W. Biederman]

"Serge E. Hallyn" <serge at hallyn.com> writes:

> Quoting Dilip Daya (dilip.daya at hp.com):
>> Hi,
>> 
>> I'd discussed the following with Serge Hallyn.
>> 
>> => Environment based on 3.2.18 / x86_64 kernel.
>> => WARNING: at fs/proc/generic.c:808 remove_proc_entry+0xdb/0x21f()
>> => WARNING: at fs/proc/generic.c:849 remove_proc_entry+0x208/0x21f()
>
> Hi,
>
> thanks much for sending this.  I'm still getting this error on
> 3.5.0-2-generic (today's ubuntu quantal kernel)
>
>> network namespace and bonding
>> -----------------------------
>> 
>> * Migrate two phy nics from host to netns (netns0).
>>   - ip link set ethX netns netns0
>> 
>> * In host environment:
>>   - load bonding module, /sbin/modprobe -v bonding mode=1 miimon=100
>>   - /sys/class/net/bond0 exists.
>>   - /proc/net/bonding/bond0 exists.
>>   - /sys/class/net/bonding_masters has bond0.
>> 
>> * Migrate bond0 to netns (netns0):
>>   - ip link set bond0 netns netns0.
>> 
>> * Within netns (netns0):
>>   - /sys/class/net/bonding_masters is empty.
>>   - /sys/class/net/bond0 exist.
>>   - configure bond0 and ifenslave with two phy nics.
>>   - /proc/net/bonding/bond0 does not exist within netns0, but does
>>     exist in the host environment.
>>   - /sys/class/net/bonding_masters is empty.
>
> mine is not empty, fwiw.  However
>
>>   - ping to remote end of bond0 works.
>> 
>> * Within netns (netns0), flushing ethX and bondY:
>>   - down bond0 and its phy nic interfaces:
>>   - ip link set ... down
>>   - ip addr flush dev [bond0 | eth#]
>>   - deleting bond0, /sbin/ip link del dev bond0
>
> Yup I still get a remove_proc_entry WARNING at fs/proc/generic.c:808,
> which is the warning when (!de)

It looks like Dilip is running an old kernel.  There should have been
some version of /sys/class/net/bonding_masters in every network
namespace since sometime in 2009.