Once flow cache is removed the mtu initialisation happens for every skb
that gets an xfrm attached to it.
It is not obvious why this lock is required -- the caller holds
reference on the state struct.
xfrm_init_state already has been called (else private data accessed
by type->get_mtu() would not be set up).
So just remove the lock -- the race on the state (DEAD?) doesn't
matter (could change right after dropping the lock too).
Signed-off-by: Florian Westphal <f...@strlen.de>
---
net/xfrm/xfrm_state.c | 13 +++++--------
1 file changed, 5 insertions(+), 8 deletions(-)
diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c
index f9a255457a1d..bf5969aa7dc2 100644
--- a/net/xfrm/xfrm_state.c
+++ b/net/xfrm/xfrm_state.c
@@ -2008,16 +2008,13 @@ EXPORT_SYMBOL(xfrm_state_delete_tunnel);
int xfrm_state_mtu(struct xfrm_state *x, int mtu)
{
- int res;
+ const struct xfrm_type *type = READ_ONCE(x->type);
- spin_lock_bh(&x->lock);
if (x->km.state == XFRM_STATE_VALID &&
- x->type && x->type->get_mtu)
- res = x->type->get_mtu(x, mtu);
- else
- res = mtu - x->props.header_len;
- spin_unlock_bh(&x->lock);
- return res;
+ type && type->get_mtu)
+ return type->get_mtu(x, mtu);
+
+ return mtu - x->props.header_len;
}
int __xfrm_init_state(struct xfrm_state *x, bool init_replay)
--
2.7.3
