ocfs2: Constify struct ocfs2_stack_operations

Commit Message

Christophe JAILLET June 14, 2024, 8:57 p.m. UTC

"struct ocfs2_stack_operations" are not modified in this driver.

Constifying this structure moves some data to a read-only section, so
increase overall security.

In order to do it, "struct ocfs2_stack_plugin" also needs to be adjusted to
this new const qualifier.

On a x86_64, with allmodconfig:
Before:
======
   text	   data	    bss	    dec	    hex	filename
   6241	    644	      0	   6885	   1ae5	fs/ocfs2/stack_o2cb.o

After:
=====
   text	   data	    bss	    dec	    hex	filename
   6337	    548	      0	   6885	   1ae5	fs/ocfs2/stack_o2cb.o

Signed-off-by: Christophe JAILLET <[e-mail]>
---
 fs/ocfs2/stack_o2cb.c | 2 +-
 fs/ocfs2/stack_user.c | 2 +-
 fs/ocfs2/stackglue.h  | 2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

Patch

diff --git a/fs/ocfs2/stack_o2cb.c b/fs/ocfs2/stack_o2cb.c
index c973c03f6fd8..10157d9d7a9c 100644
--- a/fs/ocfs2/stack_o2cb.c
+++ b/fs/ocfs2/stack_o2cb.c
@@ -404,7 +404,7 @@  static int o2cb_cluster_this_node(struct ocfs2_cluster_connection *conn,
 	return 0;
 }
 
-static struct ocfs2_stack_operations o2cb_stack_ops = {
+static const struct ocfs2_stack_operations o2cb_stack_ops = {
 	.connect	= o2cb_cluster_connect,
 	.disconnect	= o2cb_cluster_disconnect,
 	.this_node	= o2cb_cluster_this_node,
diff --git a/fs/ocfs2/stack_user.c b/fs/ocfs2/stack_user.c
index c11406cd87a8..77edcd70f72c 100644
--- a/fs/ocfs2/stack_user.c
+++ b/fs/ocfs2/stack_user.c
@@ -1065,7 +1065,7 @@  static int user_cluster_this_node(struct ocfs2_cluster_connection *conn,
 	return 0;
 }
 
-static struct ocfs2_stack_operations ocfs2_user_plugin_ops = {
+static const struct ocfs2_stack_operations ocfs2_user_plugin_ops = {
 	.connect	= user_cluster_connect,
 	.disconnect	= user_cluster_disconnect,
 	.this_node	= user_cluster_this_node,
diff --git a/fs/ocfs2/stackglue.h b/fs/ocfs2/stackglue.h
index 3636847fae19..02ab072c528a 100644
--- a/fs/ocfs2/stackglue.h
+++ b/fs/ocfs2/stackglue.h
@@ -223,7 +223,7 @@  struct ocfs2_stack_operations {
  */
 struct ocfs2_stack_plugin {
 	char *sp_name;
-	struct ocfs2_stack_operations *sp_ops;
+	const struct ocfs2_stack_operations *sp_ops;
 	struct module *sp_owner;
 
 	/* These are managed by the stackglue code. */