[lttng-dev] [PATCH lttng-tools] Fix: double put on error path

[Jérémie Galarneau]

Merged in master, stable-2.11, stable-2.10, and stable-2.9.

Thanks!
Jérémie


On Mon, Sep 10, 2018 at 08:09:11PM -0400, Jonathan Rajotte wrote:
> Let relay_index_try_flush be responsible for the self-reference put on
> error path.
> 
> Code flow of relay_index_try_flush is a bit tricky but the only error
> flow (via relay_index_file_write) will always mark the index as flushed
> and perform the self-reference put.
> 
> Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien at efficios.com>
> ---
>  src/bin/lttng-relayd/main.c | 13 +++++++++----
>  1 file changed, 9 insertions(+), 4 deletions(-)
> 
> diff --git a/src/bin/lttng-relayd/main.c b/src/bin/lttng-relayd/main.c
> index 5a3bcb43f..2e2f5839f 100644
> --- a/src/bin/lttng-relayd/main.c
> +++ b/src/bin/lttng-relayd/main.c
> @@ -2318,8 +2318,11 @@ static int relay_recv_index(const struct lttcomm_relayd_hdr *recv_hdr,
>  		/* no flush. */
>  		ret = 0;
>  	} else {
> +		/*
> +		 * relay_index_try_flush is responsible for the self-reference
> +		 * put of the index object on error.
> +		 */
>  		ERR("relay_index_try_flush error %d", ret);
> -		relay_index_put(index);
>  		ret = -1;
>  	}
>  
> @@ -3217,9 +3220,11 @@ static int handle_index_data(struct relay_stream *stream, uint64_t net_seq_num,
>  		/* No flush. */
>  		ret = 0;
>  	} else {
> -		/* Put self-ref for this index due to error. */
> -		relay_index_put(index);
> -		index = NULL;
> +		/*
> +		 * relay_index_try_flush is responsible for the self-reference
> +		 * put of the index object on error.
> +		 */
> +		ERR("relay_index_try_flush error %d", ret);
>  		ret = -1;
>  	}
>  end:
> -- 
> 2.17.1
>