X-Git-Url: http://git.efficios.com/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fbin%2Flttng-sessiond%2Fkernel.c;h=2626e98b259f46eeebbeee69be8bc1935cb43dfa;hp=76162e08c75b3b15b226f02cc4f2625519e3d064;hb=a8c3ad3e850d45026f22ecdc7ea963b7e923bd08;hpb=e04b2181d2d91179ab11f461d481830fd88afaa1

diff --git a/src/bin/lttng-sessiond/kernel.c b/src/bin/lttng-sessiond/kernel.c
index 76162e08c..2626e98b2 100644
--- a/src/bin/lttng-sessiond/kernel.c
+++ b/src/bin/lttng-sessiond/kernel.c
@@ -1289,6 +1289,7 @@ enum lttng_error_code kernel_snapshot_record(
 	struct lttng_ht_iter iter;
 	struct ltt_kernel_metadata *saved_metadata;
 	char *trace_path = NULL;
+	size_t consumer_path_offset = 0;
 
 	assert(ksess);
 	assert(ksess->consumer);
@@ -1315,7 +1316,7 @@ enum lttng_error_code kernel_snapshot_record(
 	}
 
 	trace_path = setup_channel_trace_path(ksess->consumer,
-			DEFAULT_KERNEL_TRACE_DIR);
+			DEFAULT_KERNEL_TRACE_DIR, &consumer_path_offset);
 	if (!trace_path) {
 		status = LTTNG_ERR_INVALID;
 		goto error;
@@ -1338,7 +1339,7 @@ enum lttng_error_code kernel_snapshot_record(
 		cds_list_for_each_entry(chan, &ksess->channel_list.head, list) {
 			status = consumer_snapshot_channel(socket, chan->key, output, 0,
 					ksess->uid, ksess->gid,
-					trace_path, wait,
+					&trace_path[consumer_path_offset], wait,
 					nb_packets_per_stream);
 			if (status != LTTNG_OK) {
 				(void) kernel_consumer_destroy_metadata(socket,
@@ -1349,7 +1350,8 @@ enum lttng_error_code kernel_snapshot_record(
 
 		/* Snapshot metadata, */
 		status = consumer_snapshot_channel(socket, ksess->metadata->key, output,
-				1, ksess->uid, ksess->gid, trace_path, wait, 0);
+				1, ksess->uid, ksess->gid, &trace_path[consumer_path_offset],
+				wait, 0);
 		if (status != LTTNG_OK) {
 			goto error_consumer;
 		}
@@ -1425,6 +1427,38 @@ error:
 	return ret;
 }
 
+/*
+ * Check for the support of the packet sequence number via abi version number.
+ *
+ * Return 1 on success, 0 when feature is not supported, negative value in case
+ * of errors.
+ */
+int kernel_supports_ring_buffer_packet_sequence_number(void)
+{
+	int ret = 0; // Not supported by default
+	struct lttng_kernel_tracer_abi_version abi;
+
+	ret = kernctl_tracer_abi_version(kernel_tracer_fd, &abi);
+	if (ret < 0) {
+		ERR("Failed to retrieve lttng-modules ABI version");
+		goto error;
+	}
+
+	/*
+	 * Packet sequence number was introduced in LTTng 2.8,
+	 * lttng-modules ABI 2.1.
+	 */
+	if (abi.major >= 2 && abi.minor >= 1) {
+		/* Supported */
+		ret = 1;
+	} else {
+		/* Not supported */
+		ret = 0;
+	}
+error:
+	return ret;
+}
+
 /*
  * Rotate a kernel session.
  *
@@ -1614,3 +1648,83 @@ bool kernel_tracer_is_initialized(void)
 {
 	return kernel_tracer_fd >= 0;
 }
+
+/*
+ *  Clear a kernel session.
+ *
+ * Return LTTNG_OK on success or else an LTTng error code.
+ */
+enum lttng_error_code kernel_clear_session(struct ltt_session *session)
+{
+	int ret;
+	enum lttng_error_code status = LTTNG_OK;
+	struct consumer_socket *socket;
+	struct lttng_ht_iter iter;
+	struct ltt_kernel_session *ksess = session->kernel_session;
+
+	assert(ksess);
+	assert(ksess->consumer);
+
+	DBG("Clear kernel session %s (session %" PRIu64 ")",
+			session->name, session->id);
+
+	rcu_read_lock();
+
+	if (ksess->active) {
+		ERR("Expecting inactive session %s (%" PRIu64 ")", session->name, session->id);
+		status = LTTNG_ERR_FATAL;
+		goto end;
+	}
+
+	/*
+	 * Note that this loop will end after one iteration given that there is
+	 * only one kernel consumer.
+	 */
+	cds_lfht_for_each_entry(ksess->consumer->socks->ht, &iter.iter,
+			socket, node.node) {
+		struct ltt_kernel_channel *chan;
+
+		/* For each channel, ask the consumer to clear it. */
+		cds_list_for_each_entry(chan, &ksess->channel_list.head, list) {
+			DBG("Clear kernel channel %" PRIu64 ", session %s",
+					chan->key, session->name);
+			ret = consumer_clear_channel(socket, chan->key);
+			if (ret < 0) {
+				goto error;
+			}
+		}
+
+		if (!ksess->metadata) {
+			/*
+			 * Nothing to do for the metadata.
+			 * This is a snapshot session.
+			 * The metadata is genererated on the fly.
+			 */
+			continue;
+		}
+
+		/*
+		 * Clear the metadata channel.
+		 * Metadata channel is not cleared per se but we still need to
+		 * perform a rotation operation on it behind the scene.
+		 */
+		ret = consumer_clear_channel(socket, ksess->metadata->key);
+		if (ret < 0) {
+			goto error;
+		}
+	}
+
+	goto end;
+error:
+	switch (-ret) {
+	case LTTCOMM_CONSUMERD_RELAYD_CLEAR_DISALLOWED:
+	      status = LTTNG_ERR_CLEAR_RELAY_DISALLOWED;
+	      break;
+	default:
+	      status = LTTNG_ERR_CLEAR_FAIL_CONSUMER;
+	      break;
+	}
+end:
+	rcu_read_unlock();
+	return status;
+}