btrfs: constify xattr_handler

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/btrfs/acl.c

@@ -282,14 +282,14 @@ int btrfs_acl_chmod(struct inode *inode)
 	return ret;
 }
 
-struct xattr_handler btrfs_xattr_acl_default_handler = {
+const struct xattr_handler btrfs_xattr_acl_default_handler = {
 	.prefix = POSIX_ACL_XATTR_DEFAULT,
 	.flags	= ACL_TYPE_DEFAULT,
 	.get	= btrfs_xattr_acl_get,
 	.set	= btrfs_xattr_acl_set,
 };
 
-struct xattr_handler btrfs_xattr_acl_access_handler = {
+const struct xattr_handler btrfs_xattr_acl_access_handler = {
 	.prefix = POSIX_ACL_XATTR_ACCESS,
 	.flags	= ACL_TYPE_ACCESS,
 	.get	= btrfs_xattr_acl_get,

fs/btrfs/xattr.c

@@ -282,7 +282,7 @@ ssize_t btrfs_listxattr(struct dentry *dentry, char *buffer, size_t size)
  * List of handlers for synthetic system.* attributes.  All real ondisk
  * attributes are handled directly.
  */
-struct xattr_handler *btrfs_xattr_handlers[] = {
+const struct xattr_handler *btrfs_xattr_handlers[] = {
 #ifdef CONFIG_BTRFS_FS_POSIX_ACL
 	&btrfs_xattr_acl_access_handler,
 	&btrfs_xattr_acl_default_handler,

fs/btrfs/xattr.h

@@ -21,9 +21,9 @@
 
 #include <linux/xattr.h>
 
-extern struct xattr_handler btrfs_xattr_acl_access_handler;
-extern struct xattr_handler btrfs_xattr_acl_default_handler;
-extern struct xattr_handler *btrfs_xattr_handlers[];
+extern const struct xattr_handler btrfs_xattr_acl_access_handler;
+extern const struct xattr_handler btrfs_xattr_acl_default_handler;
+extern const struct xattr_handler *btrfs_xattr_handlers[];
 
 extern ssize_t __btrfs_getxattr(struct inode *inode, const char *name,
 		void *buffer, size_t size);