From fbc907f0b1386c02e00516aa78a0fa6b0454fd0b Mon Sep 17 00:00:00 2001 From: Daniel Borkmann Date: Fri, 28 Mar 2014 18:58:20 +0100 Subject: net: filter: move filter accounting to filter core This patch basically does two things, i) removes the extern keyword from the include/linux/filter.h file to be more consistent with the rest of Joe's changes, and ii) moves filter accounting into the filter core framework. Filter accounting mainly done through sk_filter_{un,}charge() take care of the case when sockets are being cloned through sk_clone_lock() so that removal of the filter on one socket won't result in eviction as it's still referenced by the other. These functions actually belong to net/core/filter.c and not include/net/sock.h as we want to keep all that in a central place. It's also not in fast-path so uninlining them is fine and even allows us to get rd of sk_filter_release_rcu()'s EXPORT_SYMBOL and a forward declaration. Joint work with Alexei Starovoitov. Signed-off-by: Daniel Borkmann Signed-off-by: Alexei Starovoitov Cc: Pavel Emelyanov Signed-off-by: David S. Miller --- net/core/filter.c | 27 +++++++++++++++++++++++++-- 1 file changed, 25 insertions(+), 2 deletions(-) (limited to 'net/core/filter.c') diff --git a/net/core/filter.c b/net/core/filter.c index 9730e7fe4770..5b3427aaeca5 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -664,14 +664,37 @@ static void sk_release_orig_filter(struct sk_filter *fp) * sk_filter_release_rcu - Release a socket filter by rcu_head * @rcu: rcu_head that contains the sk_filter to free */ -void sk_filter_release_rcu(struct rcu_head *rcu) +static void sk_filter_release_rcu(struct rcu_head *rcu) { struct sk_filter *fp = container_of(rcu, struct sk_filter, rcu); sk_release_orig_filter(fp); bpf_jit_free(fp); } -EXPORT_SYMBOL(sk_filter_release_rcu); + +/** + * sk_filter_release - release a socket filter + * @fp: filter to remove + * + * Remove a filter from a socket and release its resources. + */ +static void sk_filter_release(struct sk_filter *fp) +{ + if (atomic_dec_and_test(&fp->refcnt)) + call_rcu(&fp->rcu, sk_filter_release_rcu); +} + +void sk_filter_uncharge(struct sock *sk, struct sk_filter *fp) +{ + atomic_sub(sk_filter_size(fp->len), &sk->sk_omem_alloc); + sk_filter_release(fp); +} + +void sk_filter_charge(struct sock *sk, struct sk_filter *fp) +{ + atomic_inc(&fp->refcnt); + atomic_add(sk_filter_size(fp->len), &sk->sk_omem_alloc); +} static int __sk_prepare_filter(struct sk_filter *fp) { -- cgit v1.2.3-59-g8ed1b