[v1,net-next,0/5] ipv4: Namespacify IPv4 address hash table.

Message

Kuniyuki Iwashima Oct. 1, 2024, 2:48 a.m. UTC

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.


Kuniyuki Iwashima (5):
  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.
  ipv4: Trigger check_lifetime() only when necessary.

 include/linux/inetdevice.h |   2 +-
 include/net/netns/ipv4.h   |   3 ++
 net/ipv4/devinet.c         | 106 +++++++++++++++++++++++++------------
 3 files changed, 76 insertions(+), 35 deletions(-)