[PATCH] Don't call request_module() under spinlock in xfrm_get_type()

[James Morris <jmorris@xxxxxxxxxxxxxxxx>]

This patch fixes a problem where request_module() was being called under 
the lock taken in xfrm_policy_get_afinfo().

An alternative fix would be to refcount xfrm_policy_afinfo structs, either
explicitly or via a module owner field, although it seems like overkill in
this case.


- James
-- 
James Morris
<jmorris@xxxxxxxxxxxxxxxx>

diff -urN -X dontdiff bk.orig/net/xfrm/xfrm_policy.c 
bk.w1/net/xfrm/xfrm_policy.c
--- bk.orig/net/xfrm/xfrm_policy.c      2003-07-06 02:59:18.000000000 +1000
+++ bk.w1/net/xfrm/xfrm_policy.c        2003-07-06 22:32:47.230524746 +1000
@@ -80,22 +80,24 @@
 
 struct xfrm_type *xfrm_get_type(u8 proto, unsigned short family)
 {
-       struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family);
+       struct xfrm_policy_afinfo *afinfo;
        struct xfrm_type_map *typemap;
        struct xfrm_type *type;
        int modload_attempted = 0;
 
+retry:
+       afinfo = xfrm_policy_get_afinfo(family);
        if (unlikely(afinfo == NULL))
                return NULL;
        typemap = afinfo->type_map;
 
-retry:
        read_lock(&typemap->lock);
        type = typemap->map[proto];
        if (unlikely(type && !try_module_get(type->owner)))
                type = NULL;
        read_unlock(&typemap->lock);
        if (!type && !modload_attempted) {
+               xfrm_policy_put_afinfo(afinfo);
                request_module("xfrm-type-%d-%d",
                               (int) family, (int) proto);
                modload_attempted = 1;