X-Git-Url: https://git.liburcu.org/?a=blobdiff_plain;f=src%2Fbin%2Flttng-sessiond%2Fcmd.c;h=5868c829f689d7015fc839ff8048197e182b5ea0;hb=19bfbd16a509837bbe57f9c00d6c2a1f0933a5a9;hp=e067cb835e1a2739dfa35f83ce32a3d3c59b586a;hpb=95b2346e7dc4f74f2bc62b65dc1eede129b17275;p=lttng-tools.git

diff --git a/src/bin/lttng-sessiond/cmd.c b/src/bin/lttng-sessiond/cmd.c
index e067cb835..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';
@@ -823,8 +819,7 @@ end:
 	return nb_event;
 
 error:
-	/* Negate the error code to differentiate the size from an error */
-	return -ret;
+	return ret;
 }
 
 /*
@@ -1512,15 +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
@@ -1569,6 +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. */
@@ -1628,6 +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;
@@ -4540,7 +4544,7 @@ int64_t get_session_nb_packets_per_stream(const struct ltt_session *session,
 		}
 		cur_nb_packets++;
 	}
-	if (!cur_nb_packets) {
+	if (!cur_nb_packets && size_left != max_size) {
 		/* Not enough room to grab one packet of each stream, error. */
 		return -1;
 	}
@@ -4653,7 +4657,7 @@ enum lttng_error_code snapshot_record(struct ltt_session *session,
 			snapshot_output->max_size);
 	if (nb_packets_per_stream < 0) {
 		ret_code = LTTNG_ERR_MAX_SIZE_INVALID;
-		goto error;
+		goto error_close_trace_chunk;
 	}
 
 	if (session->kernel_session) {
@@ -4661,7 +4665,7 @@ enum lttng_error_code snapshot_record(struct ltt_session *session,
 				snapshot_kernel_consumer_output, session,
 				wait, nb_packets_per_stream);
 		if (ret_code != LTTNG_OK) {
-			goto error;
+			goto error_close_trace_chunk;
 		}
 	}
 
@@ -4670,10 +4674,10 @@ enum lttng_error_code snapshot_record(struct ltt_session *session,
 				snapshot_ust_consumer_output, session,
 				wait, nb_packets_per_stream);
 		if (ret_code != LTTNG_OK) {
-			goto error;
+			goto error_close_trace_chunk;
 		}
 	}
-
+error_close_trace_chunk:
 	if (session_close_trace_chunk(
 			    session, session->current_trace_chunk, NULL, NULL)) {
 		/*
@@ -4907,6 +4911,12 @@ int cmd_rotate_session(struct ltt_session *session,
 		goto end;
 	}
 
+	/* Unsupported feature in lttng-modules before 2.8 (lack of sequence number). */
+	if (session->kernel_session && !kernel_supports_ring_buffer_packet_sequence_number()) {
+		cmd_ret = LTTNG_ERR_ROTATION_NOT_AVAILABLE_KERNEL;
+		goto end;
+	}
+
 	if (session->rotation_state == LTTNG_ROTATION_STATE_ONGOING) {
 		DBG("Refusing to launch a rotation; a rotation is already in progress for session %s",
 				session->name);