Re: [PATCH 03/11] blktrace: add option to request a specific trace protocol version

[Damien Le Moal <dlemoal@kernel.org>]

On 7/16/26 20:04, Johannes Thumshirn wrote:
> Add the '--trace-version=<1|2>' command line option to select the trace
> protocol version requested from the kernel. Requesting version 1 forces
> blktrace to use the old BLKTRACESETUP ioctl, while version 2 (the
> default) uses BLKTRACESETUP2.
> 
> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
> ---
>  blktrace.c     | 30 ++++++++++++++++++++++++++++--
>  doc/blktrace.8 |  7 +++++++
>  2 files changed, 35 insertions(+), 2 deletions(-)
> 
> diff --git a/blktrace.c b/blktrace.c
> index 72562fdc9d9e..35db26fd4e23 100644
> --- a/blktrace.c
> +++ b/blktrace.c
> @@ -283,6 +283,7 @@ static unsigned long long act_mask = ~0U;
>  static int kill_running_trace;
>  static int stop_watch;
>  static int piped_output;
> +static int v1;

bool ?

Or maybe less confusing/more scalable:

static int trace_ver = 2;

to match the default and the --trace-version option changes that to the
specified value? That simplifies the code below too.
>  static void clear_events(struct pollfd *pfd)
>  {
> @@ -2244,6 +2257,19 @@ static int handle_args(int argc, char *argv[])
>  		case 's':
>  			net_use_sendfile = 0;
>  			break;
> +		case OPT_TRACE_VERSION: {

		case OPT_TRACE_VERSION:
			trace_ver = atoi(optarg);
			if (trace_ver != 1 && trace_ver != 2) {
				show_usage(argv[0]);
				exit(1);
			}
			break;

> +			int ver = atoi(optarg);
> +
> +			if (ver == 1)
> +				v1 = 1;
> +			else if (ver == 2)
> +				v1 = 0;
> +			else {
> +				show_usage(argv[0]);
> +				exit(1);
> +			}
> +			break;
> +		}


-- 
Damien Le Moal
Western Digital Research