[net-next,00/16] net: more factorization in cleanup_net() paths

Message

Eric Dumazet Feb. 1, 2024, 5:09 p.m. UTC

This series is inspired by recent syzbot reports hinting to RTNL and
workqueue abuses.

rtnl_lock() is unfair to (single threaded) cleanup_net(), because
many threads can cause contention on it.

This series adds a new (struct pernet_operations) method,
so that cleanup_net() can hold RTNL longer once it finally
acquires it.

It also factorizes unregister_netdevice_many(), to further
reduce stalls in cleanup_net().

Eric Dumazet (16):
  net: add exit_batch_rtnl() method
  nexthop: convert nexthop_net_exit_batch to exit_batch_rtnl method
  net: convert default_device_exit_batch() to exit_batch_rtnl method
  bareudp: use exit_batch_rtnl() method
  bonding: use exit_batch_rtnl() method
  geneve: use exit_batch_rtnl() method
  gtp: use exit_batch_rtnl() method
  ipv4: add __unregister_nexthop_notifier()
  vxlan: use exit_batch_rtnl() method
  ip6_gre: use exit_batch_rtnl() method
  ip6_tunnel: use exit_batch_rtnl() method
  ip6_vti: use exit_batch_rtnl() method
  sit: use exit_batch_rtnl() method
  ip_tunnel: use exit_batch_rtnl() method
  bridge: use exit_batch_rtnl() method
  xfrm: interface: use exit_batch_rtnl() method

 drivers/net/bareudp.c           | 13 ++++-------
 drivers/net/bonding/bond_main.c | 20 ++++++++---------
 drivers/net/geneve.c            | 13 ++++-------
 drivers/net/gtp.c               | 20 ++++++++---------
 drivers/net/vxlan/vxlan_core.c  | 21 ++++++++++--------
 include/net/ip_tunnels.h        |  3 ++-
 include/net/net_namespace.h     |  3 +++
 include/net/nexthop.h           |  1 +
 net/bridge/br.c                 | 15 +++++--------
 net/core/dev.c                  | 13 +++++------
 net/core/net_namespace.c        | 31 ++++++++++++++++++++++++++-
 net/ipv4/ip_gre.c               | 24 +++++++++++++--------
 net/ipv4/ip_tunnel.c            | 10 ++++-----
 net/ipv4/ip_vti.c               |  8 ++++---
 net/ipv4/ipip.c                 |  8 ++++---
 net/ipv4/nexthop.c              | 38 ++++++++++++++++++++++-----------
 net/ipv6/ip6_gre.c              | 12 +++++------
 net/ipv6/ip6_tunnel.c           | 12 +++++------
 net/ipv6/ip6_vti.c              | 12 +++++------
 net/ipv6/sit.c                  | 13 +++++------
 net/xfrm/xfrm_interface_core.c  | 14 ++++++------
 21 files changed, 166 insertions(+), 138 deletions(-)