SUNRPC: Fix a performance regression in the RPC authentication code

[linux-2.6-omap-h63xx.git] / net / sunrpc / auth_generic.c

diff --git a/net/sunrpc/auth_generic.c b/net/sunrpc/auth_generic.c
index 744b79fdcb19dac256b1dea5b26dc6e87f208f07..4028502f052858b1d66af4b31c17d641c16fac0b 100644 (file)
--- a/net/sunrpc/auth_generic.c
+++ b/net/sunrpc/auth_generic.c
@@ -133,13 +133,29 @@ static int
 generic_match(struct auth_cred *acred, struct rpc_cred *cred, int flags)
 {
        struct generic_cred *gcred = container_of(cred, struct generic_cred, gc_base);
+       int i;
 
        if (gcred->acred.uid != acred->uid ||
            gcred->acred.gid != acred->gid ||
-           gcred->acred.group_info != acred->group_info ||
            gcred->acred.machine_cred != acred->machine_cred)
-               return 0;
+               goto out_nomatch;
+
+       /* Optimisation in the case where pointers are identical... */
+       if (gcred->acred.group_info == acred->group_info)
+               goto out_match;
+
+       /* Slow path... */
+       if (gcred->acred.group_info->ngroups != acred->group_info->ngroups)
+               goto out_nomatch;
+       for (i = 0; i < gcred->acred.group_info->ngroups; i++) {
+               if (GROUP_AT(gcred->acred.group_info, i) !=
+                               GROUP_AT(acred->group_info, i))
+                       goto out_nomatch;
+       }
+out_match:
        return 1;
+out_nomatch:
+       return 0;
 }
 
 void __init rpc_init_generic_auth(void)