On Thu, 29 Apr 2021 07:01:17 +0300
"Tzvetomir Stoyanov (VMware)" <tz.stoyanov@xxxxxxxxx> wrote:
> index 9231c319..f36718f1 100644
> --- a/lib/trace-cmd/trace-output.c
> +++ b/lib/trace-cmd/trace-output.c
> @@ -57,6 +57,7 @@ struct tracecmd_output {
> int nr_options;
> bool quiet;
> unsigned long file_state;
> + unsigned long file_version;
> struct list_head options;
> struct tracecmd_msg_handle *msg_handle;
> char *trace_clock;
> @@ -907,6 +908,17 @@ out_free:
> return ret;
> }
>
> +static int select_file_version(struct tracecmd_output *handle,
> + struct tracecmd_input *ihandle)
> +{
> + if (ihandle)
> + handle->file_version = tracecmd_get_file_version(ihandle);
> + else
> + handle->file_version = FILE_VERSION;
> +
> + return 0;
> +}
> +
This is where we should have the logic for what we write.
We save a string where the version is going to be located. We default it to
the lowest level (6), and then if a feature is recorded that is of a higher
version, we up it, and change the number of disk as well.
If there's a case where we get to two digit strings, we should have it be:
"6 \0"
which should still work. Then if we use a feature that requires version 10,
it would be updated to:
"10\0"
We can do this at the end of recording.
-- Steve
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