Hello, I'm doing some refactoring on btrfs and would like to convert some of the "naked" definition of UUID in on-disk object to uuid_t. Since those structs are defined in include/uapi/linux/btrfs_tree.h I naturally would need to expose the kernel uuid_t to the uapi header via include/uapi/linux/uuid.h. The uuid was originally unexported in 60927bc31436 ("uuid: remove uuid_be defintions from the uapi header") but at that time it was called uuid_be. The thing is that btrfs-progs for example uses both btrfs_tree.h uapi header as well as libuuid. THe latter also defines uuid_t. Both the kernel one and libuuid are binary compatible. So what's the correct way (if any) to expose a kernel type that might have also been defined by a userspace library? Regards, Nikolay