[ltt-dev] [UST PATCH] libust: Fix multiple fd close during fork

[Nils Carlson]

This sort of fixes things in a wider sense as with the original patch we 
might leave trailing fds open and a non "auto" trace would have been 
neither destroyed nor have its fds closed...

Hope its ok with you yannick. Keep up the good work!

/Nils

On Wed, 23 Feb 2011, Nils Carlson wrote:

> Remove superfluous fd closes during fork and also destroy all
> traces instead of just "auto".
>
> Reported-by: Yannick Brosseau <yannick.brosseau at gmail.com>
> Signed-off-by: Nils Carlson <nils.carlson at ericsson.com>
> ---
> libust/tracectl.c |   17 ++++++++---------
> 1 files changed, 8 insertions(+), 9 deletions(-)
>
> diff --git a/libust/tracectl.c b/libust/tracectl.c
> index 1bd7229..1fc0118 100644
> --- a/libust/tracectl.c
> +++ b/libust/tracectl.c
> @@ -1569,6 +1569,7 @@ static void ust_fork(void)
> {
> 	struct ust_buffer *buf, *buf_tmp;
> 	struct ustcomm_sock *sock, *sock_tmp;
> +	struct ust_trace *trace, *trace_tmp;
> 	int result;
>
> 	/* FIXME: technically, the locks could have been taken before the fork */
> @@ -1589,18 +1590,16 @@ static void ust_fork(void)
> 	/* Delete all blocked consumers */
> 	cds_list_for_each_entry_safe(buf, buf_tmp, &open_buffers_list,
> 				 open_buffers_list) {
> -		result = close(buf->data_ready_fd_read);
> -		if (result == -1) {
> -			PERROR("close");
> -		}
> -		result = close(buf->data_ready_fd_write);
> -		if (result == -1) {
> -			PERROR("close");
> -		}
> 		cds_list_del(&buf->open_buffers_list);
> 	}
>
> -	ltt_trace_destroy("auto", 1);
> +	/*
> +	 * FIXME: This could be prettier, we loop over the list twice and
> +	 * following good locking practice should lock around the loop
> +	 */
> +	cds_list_for_each_entry_safe(trace, trace_tmp, &ltt_traces.head, list) {
> +		ltt_trace_destroy(trace->trace_name, 1);
> +	}
>
> 	/* Clean up the listener socket and epoll, keeping the scoket file */
> 	ustcomm_del_named_sock(listen_sock, 1);
> -- 
> 1.7.1
>
>