ceph: move ceph_xattr_handlers to .rodata

This makes it harder for accidental or malicious changes to
ceph_xattr_handlers at runtime.

Cc: Xiubo Li <[e-mail]>
Cc: Ilya Dryomov <[e-mail]>
Cc: Jeff Layton <[e-mail]>
Cc: [e-mail]
Signed-off-by: Wedson Almeida Filho <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Acked-by: Ilya Dryomov <[e-mail]>
Signed-off-by: Christian Brauner <[e-mail]>

fs/ceph/super.h

···
 extern ssize_t ceph_listxattr(struct dentry *, char *, size_t);
 extern struct ceph_buffer *__ceph_build_xattrs_blob(struct ceph_inode_info *ci);
 extern void __ceph_destroy_xattrs(struct ceph_inode_info *ci);
-extern const struct xattr_handler *ceph_xattr_handlers[];
+extern const struct xattr_handler * const ceph_xattr_handlers[];
 
 struct ceph_acl_sec_ctx {
 #ifdef CONFIG_CEPH_FS_POSIX_ACL

fs/ceph/xattr.c

···
  * List of handlers for synthetic system.* attributes. Other
  * attributes are handled directly.
  */
-const struct xattr_handler *ceph_xattr_handlers[] = {
+const struct xattr_handler * const ceph_xattr_handlers[] = {
 	&ceph_other_xattr_handler,
 	NULL,
 };