[PATCH v2 net-next 0/4] ipv4: Namespacify IPv4 address hash table.

[Kuniyuki Iwashima <kuniyu@amazon.com>]

This is a prep of per-net RTNL conversion for RTM_(NEW|DEL|SET)ADDR.

Currently, each IPv4 address is linked to the global hash table, and
this needs to be protected by another global lock or namespacified to
support per-net RTNL.

Adding a global lock will cause deadlock in the rtnetlink path and GC,

  rtnetlink                      check_lifetime
  |- rtnl_net_lock(net)          |- acquire the global lock
  |- acquire the global lock     |- check ifa's netns
  `- put ifa into hash table     `- rtnl_net_lock(net)

so we need to namespacify the hash table.

The IPv6 one is already namespacified, let's follow that.


Changes:
  v2:
    * Drop patch 5
    * Fix sparse warning in patch 4, (__force u32)

  v1: https://lore.kernel.org/netdev/20241001024837.96425-1-kuniyu@amazon.com/


Kuniyuki Iwashima (4):
  ipv4: Link IPv4 address to per-net hash table.
  ipv4: Use per-net hash table in inet_lookup_ifaddr_rcu().
  ipv4: Namespacify IPv4 address GC.
  ipv4: Retire global IPv4 hash table inet_addr_lst.

 include/linux/inetdevice.h |  2 +-
 include/net/netns/ipv4.h   |  2 ++
 net/ipv4/devinet.c         | 73 +++++++++++++++++++++-----------------
 3 files changed, 43 insertions(+), 34 deletions(-)

-- 
2.30.2