[PATCH] radix-tree: move declarations to header

[Arnd Bergmann <arnd@kernel.org>]

From: Arnd Bergmann <arnd@arndb.de>

The xarray.c file contains the only call to radix_tree_node_rcu_free(),
and it comes with its own extern declaration for it. This means the
function definition causes a missing-prototype warning:

lib/radix-tree.c:288:6: error: no previous prototype for 'radix_tree_node_rcu_free' [-Werror=missing-prototypes]

Instead, move the declaration for this function to a new header that
can be included by both, and do the same for the radix_tree_node_cachep
variable that has the same underlying problem but does not cause
a warning with gcc.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 lib/radix-tree.c | 2 ++
 lib/radix-tree.h | 8 ++++++++
 lib/xarray.c     | 6 ++----
 3 files changed, 12 insertions(+), 4 deletions(-)
 create mode 100644 lib/radix-tree.h

diff --git a/lib/radix-tree.c b/lib/radix-tree.c
index 049ba132f7ef..1a31065b2036 100644
--- a/lib/radix-tree.c
+++ b/lib/radix-tree.c
@@ -27,6 +27,8 @@
 #include <linux/string.h>
 #include <linux/xarray.h>
 
+#include "radix-tree.h"
+
 /*
  * Radix tree node cache.
  */
diff --git a/lib/radix-tree.h b/lib/radix-tree.h
new file mode 100644
index 000000000000..40d5c03e2b09
--- /dev/null
+++ b/lib/radix-tree.h
@@ -0,0 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0+
+/* radix-tree helpers that are only shared with xarray */
+
+struct kmem_cache;
+struct rcu_head;
+
+extern struct kmem_cache *radix_tree_node_cachep;
+extern void radix_tree_node_rcu_free(struct rcu_head *head);
diff --git a/lib/xarray.c b/lib/xarray.c
index ea9ce1f0b386..2071a3718f4e 100644
--- a/lib/xarray.c
+++ b/lib/xarray.c
@@ -12,6 +12,8 @@
 #include <linux/slab.h>
 #include <linux/xarray.h>
 
+#include "radix-tree.h"
+
 /*
  * Coding conventions in this file:
  *
@@ -247,10 +249,6 @@ void *xas_load(struct xa_state *xas)
 }
 EXPORT_SYMBOL_GPL(xas_load);
 
-/* Move the radix tree node cache here */
-extern struct kmem_cache *radix_tree_node_cachep;
-extern void radix_tree_node_rcu_free(struct rcu_head *head);
-
 #define XA_RCU_FREE	((struct xarray *)1)
 
 static void xa_node_free(struct xa_node *node)
-- 
2.39.2