On Thu, Jun 29, 2017 at 6:08 PM, Eric W. Biederman <ebied...@xmission.com> wrote: > "Mahesh Bandewar (महेश बंडेवार)" <mahe...@google.com> writes: > >> Creation of new network namespace is almost always followed up by >> bringing up the loopback device. >> >> ip netns add foo >> ip -netns foo link set lo up >> >> I'm not sure if there are any consequences of bringing the device UP >> at the creation of network-namespace.jjh > > Hard coded in net/core/net_namespace.c:copy_net_ns is definitely the > wrong place in the code for something like this. If this lives anywhere > it should live in driver/net/loopback.c, or possibly in > net/core/dev.c:net_dev_init. > interestingly dev_open() needs RTNL while it's not recommended at net_dev_init() time. Also net_dev_init() is called at the sub-system registration, do you mean loopback_net_init() time?
> If we want this we want to match what we do when we the primary network > namespace. Just so that there are no unneeded surprises with network > namespaces. > Yes, correct, it should be same whether it's init-net or some other. I can add the IFF_UP flag during loopback_setup() but then it will not perform anything that is done during dev_open() phase. I'll try moving the code to loopback_net_init() to achieve the same result so that I can avoid that hard-coding too. Thanks for comments Eric. --mahesh.. > Eric
