xfrm: state: simplify rcu_read_unlock handling in two spots

[mirror_ubuntu-artful-kernel.git] / net / xfrm / xfrm_state.c

diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c
index 57e9578c35e2b6360c406adad559ecc8c9642f93..a62097e640b5690edc4d6f9bf794d1a2c80725f7 100644 (file)
--- a/net/xfrm/xfrm_state.c
+++ b/net/xfrm/xfrm_state.c
@@ -192,7 +192,7 @@ int xfrm_register_type(const struct xfrm_type *type, unsigned short family)
        else
                err = -EEXIST;
        spin_unlock_bh(&xfrm_type_lock);
-       xfrm_state_put_afinfo(afinfo);
+       rcu_read_unlock();
        return err;
 }
 EXPORT_SYMBOL(xfrm_register_type);
@@ -213,7 +213,7 @@ int xfrm_unregister_type(const struct xfrm_type *type, unsigned short family)
        else
                typemap[type->proto] = NULL;
        spin_unlock_bh(&xfrm_type_lock);
-       xfrm_state_put_afinfo(afinfo);
+       rcu_read_unlock();
        return err;
 }
 EXPORT_SYMBOL(xfrm_unregister_type);
@@ -231,17 +231,18 @@ retry:
                return NULL;
        typemap = afinfo->type_map;
 
-       type = typemap[proto];
+       type = READ_ONCE(typemap[proto]);
        if (unlikely(type && !try_module_get(type->owner)))
                type = NULL;
+
+       rcu_read_unlock();
+
        if (!type && !modload_attempted) {
-               xfrm_state_put_afinfo(afinfo);
                request_module("xfrm-type-%d-%d", family, proto);
                modload_attempted = 1;
                goto retry;
        }
 
-       xfrm_state_put_afinfo(afinfo);
        return type;
 }
 
@@ -280,7 +281,7 @@ int xfrm_register_mode(struct xfrm_mode *mode, int family)
 
 out:
        spin_unlock_bh(&xfrm_mode_lock);
-       xfrm_state_put_afinfo(afinfo);
+       rcu_read_unlock();
        return err;
 }
 EXPORT_SYMBOL(xfrm_register_mode);
@@ -308,7 +309,7 @@ int xfrm_unregister_mode(struct xfrm_mode *mode, int family)
        }
 
        spin_unlock_bh(&xfrm_mode_lock);
-       xfrm_state_put_afinfo(afinfo);
+       rcu_read_unlock();
        return err;
 }
 EXPORT_SYMBOL(xfrm_unregister_mode);
@@ -327,17 +328,17 @@ retry:
        if (unlikely(afinfo == NULL))
                return NULL;
 
-       mode = afinfo->mode_map[encap];
+       mode = READ_ONCE(afinfo->mode_map[encap]);
        if (unlikely(mode && !try_module_get(mode->owner)))
                mode = NULL;
+
+       rcu_read_unlock();
        if (!mode && !modload_attempted) {
-               xfrm_state_put_afinfo(afinfo);
                request_module("xfrm-mode-%d-%d", family, encap);
                modload_attempted = 1;
                goto retry;
        }
 
-       xfrm_state_put_afinfo(afinfo);
        return mode;
 }
 
@@ -639,26 +640,23 @@ void xfrm_sad_getinfo(struct net *net, struct xfrmk_sadinfo *si)
 }
 EXPORT_SYMBOL(xfrm_sad_getinfo);
 
-static int
+static void
 xfrm_init_tempstate(struct xfrm_state *x, const struct flowi *fl,
                    const struct xfrm_tmpl *tmpl,
                    const xfrm_address_t *daddr, const xfrm_address_t *saddr,
                    unsigned short family)
 {
-       struct xfrm_state_afinfo *afinfo = xfrm_state_get_afinfo(family);
-       if (!afinfo)
-               return -1;
-       afinfo->init_tempsel(&x->sel, fl);
+       struct xfrm_state_afinfo *afinfo = xfrm_state_afinfo_get_rcu(family);
+
+       if (afinfo)
+               afinfo->init_tempsel(&x->sel, fl);
 
        if (family != tmpl->encap_family) {
-               xfrm_state_put_afinfo(afinfo);
-               afinfo = xfrm_state_get_afinfo(tmpl->encap_family);
+               afinfo = xfrm_state_afinfo_get_rcu(tmpl->encap_family);
                if (!afinfo)
-                       return -1;
+                       return;
        }
        afinfo->init_temprop(x, tmpl, daddr, saddr);
-       xfrm_state_put_afinfo(afinfo);
-       return 0;
 }
 
 static struct xfrm_state *__xfrm_state_lookup(struct net *net, u32 mark,
@@ -1474,7 +1472,7 @@ xfrm_tmpl_sort(struct xfrm_tmpl **dst, struct xfrm_tmpl **src, int n,
        if (afinfo->tmpl_sort)
                err = afinfo->tmpl_sort(dst, src, n);
        spin_unlock_bh(&net->xfrm.xfrm_state_lock);
-       xfrm_state_put_afinfo(afinfo);
+       rcu_read_unlock();
        return err;
 }
 EXPORT_SYMBOL(xfrm_tmpl_sort);
@@ -1494,7 +1492,7 @@ xfrm_state_sort(struct xfrm_state **dst, struct xfrm_state **src, int n,
        if (afinfo->state_sort)
                err = afinfo->state_sort(dst, src, n);
        spin_unlock_bh(&net->xfrm.xfrm_state_lock);
-       xfrm_state_put_afinfo(afinfo);
+       rcu_read_unlock();
        return err;
 }
 EXPORT_SYMBOL(xfrm_state_sort);
@@ -1966,6 +1964,14 @@ int xfrm_state_unregister_afinfo(struct xfrm_state_afinfo *afinfo)
 }
 EXPORT_SYMBOL(xfrm_state_unregister_afinfo);
 
+struct xfrm_state_afinfo *xfrm_state_afinfo_get_rcu(unsigned int family)
+{
+       if (unlikely(family >= NPROTO))
+               return NULL;
+
+       return rcu_dereference(xfrm_state_afinfo[family]);
+}
+
 struct xfrm_state_afinfo *xfrm_state_get_afinfo(unsigned int family)
 {
        struct xfrm_state_afinfo *afinfo;
@@ -1978,11 +1984,6 @@ struct xfrm_state_afinfo *xfrm_state_get_afinfo(unsigned int family)
        return afinfo;
 }
 
-void xfrm_state_put_afinfo(struct xfrm_state_afinfo *afinfo)
-{
-       rcu_read_unlock();
-}
-
 /* Temporarily located here until net/xfrm/xfrm_tunnel.c is created */
 void xfrm_state_delete_tunnel(struct xfrm_state *x)
 {
@@ -2025,7 +2026,7 @@ int __xfrm_init_state(struct xfrm_state *x, bool init_replay)
        if (afinfo->init_flags)
                err = afinfo->init_flags(x);
 
-       xfrm_state_put_afinfo(afinfo);
+       rcu_read_unlock();
 
        if (err)
                goto error;