Re: [PATCH v2 1/8] rt-utils.c: Check return values of write()

[John Kacur <jkacur@redhat.com>]

On Sat, 26 Jul 2025, Cheng-Yang Chou wrote:

> Add error handling for write() to tracefs in tracemark() to avoid ignoring
> partial or failed writes.
> 
> Signed-off-by: Cheng-Yang Chou <yphbchou0911@gmail.com>
> ---
>  src/lib/rt-utils.c | 9 +++++++--
>  1 file changed, 7 insertions(+), 2 deletions(-)
> 
> diff --git a/src/lib/rt-utils.c b/src/lib/rt-utils.c
> index 6bbd25a..447e158 100644
> --- a/src/lib/rt-utils.c
> +++ b/src/lib/rt-utils.c
> @@ -465,6 +465,7 @@ void tracemark(char *fmt, ...)
>  {
>  	va_list ap;
>  	int len;
> +	int ret;
>  
>  	/* bail out if we're not tracing */
>  	/* or if the kernel doesn't support trace_mark */
> @@ -476,10 +477,14 @@ void tracemark(char *fmt, ...)
>  	va_end(ap);
>  
>  	/* write the tracemark message */
> -	write(tracemark_fd, tracebuf, len);
> +	ret = write(tracemark_fd, tracebuf, len);
> +	if (ret != len)
> +		warn("%s: write failed", __func__);
>  
>  	/* now stop any trace */
> -	write(trace_fd, "0\n", 2);
> +	ret = write(trace_fd, "0\n", 2);
> +	if (ret != 2)
> +		warn("trace stop write failed");
>  }
>  
>  void enable_trace_mark(void)
> -- 
    - resolved merge conflict because an earlier patch changed tracemark()
      and tracing_stop() since this was submitted
    Signed-off-by: John Kacur <jkacur@redhat.com>