squashfs: constify xattr handlers

Signed-off-by: Phillip Lougher <[e-mail]>

fs/squashfs/squashfs.h

···
 extern const struct inode_operations squashfs_symlink_inode_ops;
 
 /* xattr.c */
-extern struct xattr_handler *squashfs_xattr_handlers[];
+extern const struct xattr_handler *squashfs_xattr_handlers[];
 
 /* zlib_wrapper.c */
 extern const struct squashfs_decompressor squashfs_zlib_comp_ops;

fs/squashfs/xattr.c

···
 #include "squashfs_fs_i.h"
 #include "squashfs.h"
 
-static struct xattr_handler *squashfs_xattr_handler(int);
+static const struct xattr_handler *squashfs_xattr_handler(int);
 
 ssize_t squashfs_listxattr(struct dentry *d, char *buffer,
 	size_t buffer_size)
···
 	while (count--) {
 		struct squashfs_xattr_entry entry;
 		struct squashfs_xattr_val val;
-		struct xattr_handler *handler;
+		const struct xattr_handler *handler;
 		int name_size, prefix_size = 0;
 
 		err = squashfs_read_metadata(sb, &entry, &start, &offset,
···
 		buffer, size);
 }
 
-static struct xattr_handler squashfs_xattr_user_handler = {
+static const struct xattr_handler squashfs_xattr_user_handler = {
 	.prefix	= XATTR_USER_PREFIX,
 	.list	= squashfs_user_list,
 	.get	= squashfs_user_get
···
 		buffer, size);
 }
 
-static struct xattr_handler squashfs_xattr_trusted_handler = {
+static const struct xattr_handler squashfs_xattr_trusted_handler = {
 	.prefix	= XATTR_TRUSTED_PREFIX,
 	.list	= squashfs_trusted_list,
 	.get	= squashfs_trusted_get
···
 		buffer, size);
 }
 
-static struct xattr_handler squashfs_xattr_security_handler = {
+static const struct xattr_handler squashfs_xattr_security_handler = {
 	.prefix	= XATTR_SECURITY_PREFIX,
 	.list	= squashfs_security_list,
 	.get	= squashfs_security_get
 };
 
-static inline struct xattr_handler *squashfs_xattr_handler(int type)
+static inline const struct xattr_handler *squashfs_xattr_handler(int type)
 {
 	if (type & ~(SQUASHFS_XATTR_PREFIX_MASK | SQUASHFS_XATTR_VALUE_OOL))
 		/* ignore unrecognised type */
···
 	}
 }
 
-struct xattr_handler *squashfs_xattr_handlers[] = {
+const struct xattr_handler *squashfs_xattr_handlers[] = {
 	&squashfs_xattr_user_handler,
 	&squashfs_xattr_trusted_handler,
 	&squashfs_xattr_security_handler,