Re: [PATCH v4] Add ioctls to get/set the ext4 superblock uuid.

Matthew Wilcox
2022-07-20T03:19:18Z

On Tue, Jul 19, 2022 at 04:41:31PM -0700, Jeremy Bongio wrote:
> +/*
> + * Structure for EXT4_IOC_GETFSUUID/EXT4_IOC_SETFSUUID
> + */
> +struct fsuuid {
> + __u32 fsu_len;
> + __u32 fsu_flags;
> + __u8 fsu_uuid[];
> +};

A UUID has a defined size (128 bits):
https://en.wikipedia.org/wiki/Universally_unique_identifier

Why are we defining flags and len?