[PATCH net-next 0/2] sit: prepare for RTNL-less link dumping

[Eric Dumazet <edumazet@google.com>]

This series prepares the SIT tunnel driver for RTNL-less link info dumping.

To do so, we need to ensure that configuration reads in ipip6_fill_info()
can run safely concurrently with configuration updates
(via netlink changelink or ioctls).

First patch fixes a long-standing bug in the shared
ip_tunnel_encap_setup() helper (used by SIT and other IPv4 tunnels),
which cleared the encapsulation configuration even if the setup failed,
and adds WRITE_ONCE() annotations to protect concurrent readers.

Second patch updates SIT's fill_info() to use READ_ONCE()
for lockless reads, and updates the write paths to use WRITE_ONCE().

Eric Dumazet (2):
  ip_tunnel: use WRITE_ONCE in ip_tunnel_encap_setup
  sit: no longer rely on RTNL in ipip6_fill_info()

 net/ipv4/ip_tunnel.c | 14 ++++-----
 net/ipv6/sit.c       | 70 +++++++++++++++++++++++++-------------------
 2 files changed, 46 insertions(+), 38 deletions(-)

-- 
2.55.0.rc0.799.gd6f94ed593-goog