ocfs2: constify struct ocfs2_lock_res_ops

"struct ocfs2_lock_res_ops" 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_lock_res" also needs to be adjusted to
this new const qualifier.

On a x86_64, with allmodconfig:
Before:
======
   text	   data	    bss	    dec	    hex	filename
  83038	   2632	    400	  86070	  15036	fs/ocfs2/dlmglue.o

After:
=====
   text	   data	    bss	    dec	    hex	filename
  83806	   1992	    272	  86070	  15036	fs/ocfs2/dlmglue.o

Link: https://lkml.kernel.org/r/43d3e2ae3a97d3cbe93d6ba6ce48ae5ec04d7526.1718382288.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Christophe JAILLET <[email protected]>
Cc: Mark Fasheh <[email protected]>
Cc: Joel Becker <[email protected]>
Cc: Junxiao Bi <[email protected]>
Cc: Joseph Qi <[email protected]>
Cc: Changwei Ge <[email protected]>
Cc: Gang He <[email protected]>
Cc: Jun Piao <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

Author: tititiou36

fs/ocfs2/dlmglue.c

@@ -221,63 +221,63 @@ struct ocfs2_lock_res_ops {
  */
 #define LOCK_TYPE_USES_LVB		0x2
 
-static struct ocfs2_lock_res_ops ocfs2_inode_rw_lops = {
+static const struct ocfs2_lock_res_ops ocfs2_inode_rw_lops = {
 	.get_osb	= ocfs2_get_inode_osb,
 	.flags		= 0,
 };
 
-static struct ocfs2_lock_res_ops ocfs2_inode_inode_lops = {
+static const struct ocfs2_lock_res_ops ocfs2_inode_inode_lops = {
 	.get_osb	= ocfs2_get_inode_osb,
 	.check_downconvert = ocfs2_check_meta_downconvert,
 	.set_lvb	= ocfs2_set_meta_lvb,
 	.downconvert_worker = ocfs2_data_convert_worker,
 	.flags		= LOCK_TYPE_REQUIRES_REFRESH|LOCK_TYPE_USES_LVB,
 };
 
-static struct ocfs2_lock_res_ops ocfs2_super_lops = {
+static const struct ocfs2_lock_res_ops ocfs2_super_lops = {
 	.flags		= LOCK_TYPE_REQUIRES_REFRESH,
 };
 
-static struct ocfs2_lock_res_ops ocfs2_rename_lops = {
+static const struct ocfs2_lock_res_ops ocfs2_rename_lops = {
 	.flags		= 0,
 };
 
-static struct ocfs2_lock_res_ops ocfs2_nfs_sync_lops = {
+static const struct ocfs2_lock_res_ops ocfs2_nfs_sync_lops = {
 	.flags		= 0,
 };
 
-static struct ocfs2_lock_res_ops ocfs2_trim_fs_lops = {
+static const struct ocfs2_lock_res_ops ocfs2_trim_fs_lops = {
 	.flags		= LOCK_TYPE_REQUIRES_REFRESH|LOCK_TYPE_USES_LVB,
 };
 
-static struct ocfs2_lock_res_ops ocfs2_orphan_scan_lops = {
+static const struct ocfs2_lock_res_ops ocfs2_orphan_scan_lops = {
 	.flags		= LOCK_TYPE_REQUIRES_REFRESH|LOCK_TYPE_USES_LVB,
 };
 
-static struct ocfs2_lock_res_ops ocfs2_dentry_lops = {
+static const struct ocfs2_lock_res_ops ocfs2_dentry_lops = {
 	.get_osb	= ocfs2_get_dentry_osb,
 	.post_unlock	= ocfs2_dentry_post_unlock,
 	.downconvert_worker = ocfs2_dentry_convert_worker,
 	.flags		= 0,
 };
 
-static struct ocfs2_lock_res_ops ocfs2_inode_open_lops = {
+static const struct ocfs2_lock_res_ops ocfs2_inode_open_lops = {
 	.get_osb	= ocfs2_get_inode_osb,
 	.flags		= 0,
 };
 
-static struct ocfs2_lock_res_ops ocfs2_flock_lops = {
+static const struct ocfs2_lock_res_ops ocfs2_flock_lops = {
 	.get_osb	= ocfs2_get_file_osb,
 	.flags		= 0,
 };
 
-static struct ocfs2_lock_res_ops ocfs2_qinfo_lops = {
+static const struct ocfs2_lock_res_ops ocfs2_qinfo_lops = {
 	.set_lvb	= ocfs2_set_qinfo_lvb,
 	.get_osb	= ocfs2_get_qinfo_osb,
 	.flags		= LOCK_TYPE_REQUIRES_REFRESH | LOCK_TYPE_USES_LVB,
 };
 
-static struct ocfs2_lock_res_ops ocfs2_refcount_block_lops = {
+static const struct ocfs2_lock_res_ops ocfs2_refcount_block_lops = {
 	.check_downconvert = ocfs2_check_refcount_downconvert,
 	.downconvert_worker = ocfs2_refcount_convert_worker,
 	.flags		= 0,
@@ -510,7 +510,7 @@ static inline void ocfs2_init_start_time(struct ocfs2_mask_waiter *mw)
 static void ocfs2_lock_res_init_common(struct ocfs2_super *osb,
 				       struct ocfs2_lock_res *res,
 				       enum ocfs2_lock_type type,
-				       struct ocfs2_lock_res_ops *ops,
+				       const struct ocfs2_lock_res_ops *ops,
 				       void *priv)
 {
 	res->l_type          = type;
@@ -553,7 +553,7 @@ void ocfs2_inode_lock_res_init(struct ocfs2_lock_res *res,
 			       unsigned int generation,
 			       struct inode *inode)
 {
-	struct ocfs2_lock_res_ops *ops;
+	const struct ocfs2_lock_res_ops *ops;
 
 	switch(type) {
 		case OCFS2_LOCK_TYPE_RW:

fs/ocfs2/ocfs2.h

@@ -154,7 +154,7 @@ struct ocfs2_lock_stats {
 
 struct ocfs2_lock_res {
 	void                    *l_priv;
-	struct ocfs2_lock_res_ops *l_ops;
+	const struct ocfs2_lock_res_ops *l_ops;
 
 
 	struct list_head         l_blocked_list;