X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=src%2Fbin%2Flttng-sessiond%2Fcmd.c;h=5868c829f689d7015fc839ff8048197e182b5ea0;hb=19bfbd16a509837bbe57f9c00d6c2a1f0933a5a9;hp=31eb2b43025f6d0207ed3e840c634dabc25b405a;hpb=72d6ec2febbc7381fbb92f902ee595e967a57b36;p=lttng-tools.git

diff --git a/src/bin/lttng-sessiond/cmd.c b/src/bin/lttng-sessiond/cmd.c
index 31eb2b430..5868c829f 100644
--- a/src/bin/lttng-sessiond/cmd.c
+++ b/src/bin/lttng-sessiond/cmd.c
@@ -517,7 +517,6 @@ static int list_lttng_agent_events(struct agent *agt,
 
 	rcu_read_lock();
 	nb_event = lttng_ht_get_count(agt->events);
-	rcu_read_unlock();
 	if (nb_event == 0) {
 		ret = nb_event;
 		*total_size = 0;
@@ -531,7 +530,6 @@ static int list_lttng_agent_events(struct agent *agt,
 	 * This is only valid because the commands which add events are
 	 * processed in the same thread as the listing.
 	 */
-	rcu_read_lock();
 	cds_lfht_for_each_entry(agt->events->ht, &iter.iter, event, node.node) {
 		ret = increment_extended_len(event->filter_expression, NULL, NULL,
 				&extended_len);
@@ -541,7 +539,6 @@ static int list_lttng_agent_events(struct agent *agt,
 			goto error;
 		}
 	}
-	rcu_read_unlock();
 
 	*total_size = nb_event * sizeof(*tmp_events) + extended_len;
 	tmp_events = zmalloc(*total_size);
@@ -554,7 +551,6 @@ static int list_lttng_agent_events(struct agent *agt,
 	extended_at = ((uint8_t *) tmp_events) +
 		nb_event * sizeof(struct lttng_event);
 
-	rcu_read_lock();
 	cds_lfht_for_each_entry(agt->events->ht, &iter.iter, event, node.node) {
 		strncpy(tmp_events[i].name, event->name, sizeof(tmp_events[i].name));
 		tmp_events[i].name[sizeof(tmp_events[i].name) - 1] = '\0';
@@ -1511,15 +1507,6 @@ int cmd_enable_channel(struct ltt_session *session,
 
 	rcu_read_lock();
 
-	/*
-	 * Don't try to enable a channel if the session has been started at
-	 * some point in time before. The tracer does not allow it.
-	 */
-	if (session->has_been_started) {
-		ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
-		goto error;
-	}
-
 	/*
 	 * If the session is a live session, remove the switch timer, the
 	 * live timer does the same thing but sends also synchronisation
@@ -1568,6 +1555,15 @@ int cmd_enable_channel(struct ltt_session *session,
 		kchan = trace_kernel_get_channel_by_name(attr.name,
 				session->kernel_session);
 		if (kchan == NULL) {
+			/*
+			 * Don't try to create a channel if the session has been started at
+			 * some point in time before. The tracer does not allow it.
+			 */
+			if (session->has_been_started) {
+				ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
+				goto error;
+			}
+
 			if (session->snapshot.nb_output > 0 ||
 					session->snapshot_mode) {
 				/* Enforce mmap output for snapshot sessions. */
@@ -1627,6 +1623,15 @@ int cmd_enable_channel(struct ltt_session *session,
 
 		uchan = trace_ust_find_channel_by_name(chan_ht, attr.name);
 		if (uchan == NULL) {
+			/*
+			 * Don't try to create a channel if the session has been started at
+			 * some point in time before. The tracer does not allow it.
+			 */
+			if (session->has_been_started) {
+				ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
+				goto error;
+			}
+
 			ret = channel_ust_create(usess, &attr, domain->buf_type);
 			if (attr.name[0] != '\0') {
 				usess->has_non_default_channel = 1;