[Cluster-devel] [PATCH] srcutree: use export for srcu_struct defined by DEFINE_STATIC_SRCU()

[Alexander Aring]

This patch fixes a sparse issue if DEFINE_STATIC_SRCU() of srcutree is
used by a module. Sparse will show:

sparse: symbol '__srcu_struct_nodes_srcu' was not declared. Should it be static?

The problem is here that the DEFINE_STATIC_SRCU() of srcutree uses
__DEFINE_SRCU() and define a non-static srcu_struct. This srcu_struct
will be exported by inserting it in a special module section
'__section("___srcu_struct_ptrs")'. During load/unloading srcutree runs
their init/cleanup functionality. It seems sparse does not understand
this connection. To avoid the sparse warning we make a prototype of the
exported srcu_struct with an export keyword. This way we tell the
that the srcu_struct might be used outside of the module.

Signed-off-by: Alexander Aring <aahringo at redhat.com>
---
 include/linux/srcutree.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/include/linux/srcutree.h b/include/linux/srcutree.h
index cb1f4351e8ba..f81be0749484 100644
--- a/include/linux/srcutree.h
+++ b/include/linux/srcutree.h
@@ -121,6 +121,7 @@ struct srcu_struct {
 #ifdef MODULE
 # define __DEFINE_SRCU(name, is_static)					\
 	is_static struct srcu_struct name;				\
+	extern struct srcu_struct * const __srcu_struct_##name;		\
 	struct srcu_struct * const __srcu_struct_##name			\
 		__section("___srcu_struct_ptrs") = &name
 #else
-- 
2.31.1