Use case-scope error labels when handling LTTNG_CONSUMER_GET_CHANNEL

This cleans-up the error handling of the case handling the
LTTNG_CONSUMER_GET_CHANNEL command. This is done in order to allow a
follow-up commit to perform some common clean-up operations on error
while introducing as few changes as possible.

No behaviour change is intended beyond additional calls to
health_code_update() in some code paths which should have no impact.

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

diff --git a/src/common/ust-consumer/ust-consumer.c b/src/common/ust-consumer/ust-consumer.c
index 4a7efad3ec28dcbea09a6a070b9f9aef5a16dbef..b2c454deb54302362806dd80180f9b235f29e33a 100644 (file)
--- a/src/common/ust-consumer/ust-consumer.c
+++ b/src/common/ust-consumer/ust-consumer.c
@@ -1591,7 +1591,7 @@ int lttng_ustconsumer_recv_cmd(struct lttng_consumer_local_data *ctx,
                if (!channel) {
                        ERR("UST consumer get channel key %" PRIu64 " not found", key);
                        ret_code = LTTCOMM_CONSUMERD_CHAN_NOT_FOUND;
-                       goto end_msg_sessiond;
+                       goto end_get_channel;
                }
 
                health_code_update();
@@ -1607,13 +1607,13 @@ int lttng_ustconsumer_recv_cmd(struct lttng_consumer_local_data *ctx,
                                 * and the consumer can continue its work. The above call
                                 * has sent the error status message to the sessiond.
                                 */
-                               goto end_nosignal;
+                               goto end_get_channel_nosignal;
                        }
                        /*
                         * The communicaton was broken hence there is a bad state between
                         * the consumer and sessiond so stop everything.
                         */
-                       goto error_fatal;
+                       goto error_get_channel_fatal;
                }
 
                health_code_update();
@@ -1623,7 +1623,7 @@ int lttng_ustconsumer_recv_cmd(struct lttng_consumer_local_data *ctx,
                 * so don't send them to the data thread.
                 */
                if (!channel->monitor) {
-                       goto end_msg_sessiond;
+                       goto end_get_channel;
                }
 
                ret = send_streams_to_thread(channel, ctx);
@@ -1632,11 +1632,16 @@ int lttng_ustconsumer_recv_cmd(struct lttng_consumer_local_data *ctx,
                         * If we are unable to send the stream to the thread, there is
                         * a big problem so just stop everything.
                         */
-                       goto error_fatal;
+                       goto error_get_channel_fatal;
                }
                /* List MUST be empty after or else it could be reused. */
                assert(cds_list_empty(&channel->streams.head));
+end_get_channel:
                goto end_msg_sessiond;
+error_get_channel_fatal:
+               goto error_fatal;
+end_get_channel_nosignal:
+               goto end_nosignal;
        }
        case LTTNG_CONSUMER_DESTROY_CHANNEL:
        {
@@ -2115,15 +2120,12 @@ int lttng_ustconsumer_recv_cmd(struct lttng_consumer_local_data *ctx,
        }
 
 end_nosignal:
-       rcu_read_unlock();
-
-       health_code_update();
-
        /*
         * Return 1 to indicate success since the 0 value can be a socket
         * shutdown during the recv() or send() call.
         */
-       return 1;
+       ret = 1;
+       goto end;
 
 end_msg_sessiond:
        /*
@@ -2135,11 +2137,9 @@ end_msg_sessiond:
        if (ret < 0) {
                goto error_fatal;
        }
-       rcu_read_unlock();
-
-       health_code_update();
+       ret = 1;
+       goto end;
 
-       return 1;
 end_channel_error:
        if (channel) {
                pthread_mutex_unlock(&channel->lock);
@@ -2155,15 +2155,18 @@ end_channel_error:
                /* Stop everything if session daemon can not be notified. */
                goto error_fatal;
        }
-       rcu_read_unlock();
-
-       health_code_update();
+       ret = 1;
+       goto end;
 
-       return 1;
 error_fatal:
-       rcu_read_unlock();
        /* This will issue a consumer stop. */
-       return -1;
+       ret = -1;
+       goto end;
+
+end:
+       rcu_read_unlock();
+       health_code_update();
+       return ret;
 }
 
 /*