On Tue, Aug 21, 2018 at 10:25:50PM +0300, Nikolay Borisov wrote:
> 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?
Please just use an raw array of __u8 for your APIs.
