Merge branch 'rtnetlink-refactor-rtnl_-new-del-set-link-for-per-netns-rtnl'

Kuniyuki Iwashima says:

====================
rtnetlink: Refactor rtnl_{new,del,set}link() for per-netns RTNL.

This is a prep for the next series where we will push RTNL down to
rtnl_{new,del,set}link().

That means, for example, __rtnl_newlink() is always under RTNL, but
rtnl_newlink() has a non-RTNL section.

As a prerequisite for per-netns RTNL, we will move netns validation
(and RTNL-independent validations if possible) to that section.

rtnl_link_ops and rtnl_af_ops will be protected with SRCU not to
depend on RTNL.

Changes:
  v2:
    * Add Eric's Reviewed-by to patch 1-4,6,8-11, (no tag on 5,7,12-14)
    * Patch 7
      * Handle error of init_srcu_struct().
      * Call cleanup_srcu_struct() after synchronize_srcu().
    * Patch 12
      * Move put_net() before errorout label
    * Patch 13
      * Newly added as prep for patch 14
    * Patch 14
      * Handle error of init_srcu_struct().
      * Call cleanup_srcu_struct() after synchronize_srcu().

  v1: https://lore.kernel.org/netdev/20241009231656.57830-1-kuniyu@amazon.com/
====================

Link: https://patch.msgid.link/20241016185357.83849-1-kuniyu@amazon.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>