commit df4a902509 upstream.
'lookup' is always followed by 'add'.
Merge both and make the list-walk part of nf_conncount_add().
This also avoids one unneeded unlock/re-lock pair.
Extra care needs to be taken in count_tree, as we only hold rcu
read lock, i.e. we can only insert to an existing tree node after
acquiring its lock and making sure it has a nonzero count.
As a zero count should be rare, just fall back to insert_tree()
(which acquires tree lock).
This issue and its solution were pointed out by Shawn Bohrer
during patch review.
Reviewed-by: Shawn Bohrer <sbohrer@cloudflare.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
bdc6c893ba