From 44abdc3047aecafc141dfbaf1ed4bcb77f5d1652 Mon Sep 17 00:00:00 2001 From: Cong Wang Date: Wed, 16 Jan 2013 16:05:05 +0800 Subject: [PATCH] xfrm: replace rwlock on xfrm_state_afinfo with rcu Similar to commit 418a99ac6ad487dc9c42e6b0e85f941af56330f2 (Replace rwlock on xfrm_policy_afinfo with rcu), the rwlock on xfrm_state_afinfo can be replaced by RCU too. Cc: Steffen Klassert Cc: Herbert Xu Cc: "David S. Miller" Signed-off-by: Cong Wang Signed-off-by: Steffen Klassert --- net/xfrm/xfrm_state.c | 33 ++++++++++++++++----------------- 1 file changed, 16 insertions(+), 17 deletions(-) diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c index 05db2362a231..64780a6f7b86 100644 --- a/net/xfrm/xfrm_state.c +++ b/net/xfrm/xfrm_state.c @@ -158,8 +158,8 @@ out_unlock: mutex_unlock(&hash_resize_mutex); } -static DEFINE_RWLOCK(xfrm_state_afinfo_lock); -static struct xfrm_state_afinfo *xfrm_state_afinfo[NPROTO]; +static DEFINE_SPINLOCK(xfrm_state_afinfo_lock); +static struct xfrm_state_afinfo __rcu *xfrm_state_afinfo[NPROTO]; static DEFINE_SPINLOCK(xfrm_state_gc_lock); @@ -173,17 +173,16 @@ static struct xfrm_state_afinfo *xfrm_state_lock_afinfo(unsigned int family) struct xfrm_state_afinfo *afinfo; if (unlikely(family >= NPROTO)) return NULL; - write_lock_bh(&xfrm_state_afinfo_lock); + spin_lock_bh(&xfrm_state_afinfo_lock); afinfo = xfrm_state_afinfo[family]; if (unlikely(!afinfo)) - write_unlock_bh(&xfrm_state_afinfo_lock); + spin_unlock_bh(&xfrm_state_afinfo_lock); return afinfo; } static void xfrm_state_unlock_afinfo(struct xfrm_state_afinfo *afinfo) - __releases(xfrm_state_afinfo_lock) { - write_unlock_bh(&xfrm_state_afinfo_lock); + spin_unlock_bh(&xfrm_state_afinfo_lock); } int xfrm_register_type(const struct xfrm_type *type, unsigned short family) @@ -1845,12 +1844,12 @@ int xfrm_state_register_afinfo(struct xfrm_state_afinfo *afinfo) return -EINVAL; if (unlikely(afinfo->family >= NPROTO)) return -EAFNOSUPPORT; - write_lock_bh(&xfrm_state_afinfo_lock); + spin_lock_bh(&xfrm_state_afinfo_lock); if (unlikely(xfrm_state_afinfo[afinfo->family] != NULL)) err = -ENOBUFS; else - xfrm_state_afinfo[afinfo->family] = afinfo; - write_unlock_bh(&xfrm_state_afinfo_lock); + rcu_assign_pointer(xfrm_state_afinfo[afinfo->family], afinfo); + spin_unlock_bh(&xfrm_state_afinfo_lock); return err; } EXPORT_SYMBOL(xfrm_state_register_afinfo); @@ -1862,14 +1861,15 @@ int xfrm_state_unregister_afinfo(struct xfrm_state_afinfo *afinfo) return -EINVAL; if (unlikely(afinfo->family >= NPROTO)) return -EAFNOSUPPORT; - write_lock_bh(&xfrm_state_afinfo_lock); + spin_lock_bh(&xfrm_state_afinfo_lock); if (likely(xfrm_state_afinfo[afinfo->family] != NULL)) { if (unlikely(xfrm_state_afinfo[afinfo->family] != afinfo)) err = -EINVAL; else - xfrm_state_afinfo[afinfo->family] = NULL; + RCU_INIT_POINTER(xfrm_state_afinfo[afinfo->family], NULL); } - write_unlock_bh(&xfrm_state_afinfo_lock); + spin_unlock_bh(&xfrm_state_afinfo_lock); + synchronize_rcu(); return err; } EXPORT_SYMBOL(xfrm_state_unregister_afinfo); @@ -1879,17 +1879,16 @@ static struct xfrm_state_afinfo *xfrm_state_get_afinfo(unsigned int family) struct xfrm_state_afinfo *afinfo; if (unlikely(family >= NPROTO)) return NULL; - read_lock(&xfrm_state_afinfo_lock); - afinfo = xfrm_state_afinfo[family]; + rcu_read_lock(); + afinfo = rcu_dereference(xfrm_state_afinfo[family]); if (unlikely(!afinfo)) - read_unlock(&xfrm_state_afinfo_lock); + rcu_read_unlock(); return afinfo; } static void xfrm_state_put_afinfo(struct xfrm_state_afinfo *afinfo) - __releases(xfrm_state_afinfo_lock) { - read_unlock(&xfrm_state_afinfo_lock); + rcu_read_unlock(); } /* Temporarily located here until net/xfrm/xfrm_tunnel.c is created */ -- 2.30.2