[PATCH net-next 0/5] Per-net and on-demand link indices (and related) v3

Hi!

This set tries to summarize the recent discussion of making ifindices friendly
to checkpoint-restore and consists of:

1. Prepare hash function to non-unique ifindices
2. Allow for specifying the desired ifindex on net link creation
3. Make ifindex generation per-net
4. Simplify loopback device ifindex access


Changes since v2:

* The pointer hash mix routine is rewritten
* Put ifindex on struct net in a better place
* Fixed compatibility on veth peer device ifindex configuration

Changes since v1:

* Fixed a stupid mistake with a pointer bits shift
* Turned the netdev_hash_mix routine into the generic ptr_hash_mix one
* Added a comment describing why loopback index is always 1 after the patch

Thanks,
Pavel