On Tue, Apr 30, 2019 at 09:28:15PM -0700, Chaitanya Kulkarni wrote:
> @@ -104,7 +120,12 @@ struct blk_io_trace {
> __u64 time; /* in nanoseconds */
> __u64 sector; /* disk offset */
> __u32 bytes; /* transfer length */
> +
> +#ifdef CONFIG_BLKTRACE_EXT
> + __u64 action; /* what happened */
> +#else
> __u32 action; /* what happened */
> +#endif /* CONFIG_BLKTRACE_EXT */
You can't use CONFIG_ symbols in UAPI headers, as userspace
applications won't set it. You also can't ever change the layout of an
existing structure in UAPI headers in not backward compatible way.
