netlink: Re-add locking to netlink_lookup() and seq walker
authorThomas Graf <tgraf@suug.ch>
Tue, 21 Oct 2014 20:05:38 +0000 (22:05 +0200)
committerDavid S. Miller <davem@davemloft.net>
Wed, 22 Oct 2014 01:34:49 +0000 (21:34 -0400)
commit78fd1d0ab072d4d9b5f0b7c14a1516665170b565
treeb71cfdca2eb841bd75355f6d8e29c53739a50ee3
parent1a194c2d59c55c37cb4c0c459d5418071a141341
netlink: Re-add locking to netlink_lookup() and seq walker

The synchronize_rcu() in netlink_release() introduces unacceptable
latency. Reintroduce minimal lookup so we can drop the
synchronize_rcu() until socket destruction has been RCUfied.

Cc: David S. Miller <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Reported-by: Steinar H. Gunderson <sgunderson@bigfoot.com>
Reported-and-tested-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
net/netlink/af_netlink.c