X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=src%2Fbin%2Flttng-sessiond%2Fkernel.c;h=fc817b2db304187675a38e1c5d8904658fe670a5;hb=e098433c90550d74288498f8c4474ef4c2daea68;hp=158a12a3633fa54100c81d0f5179b6c2c9d9c68e;hpb=0a28e5534ea9d68c19c57f2453e789a7188e16b4;p=lttng-tools.git

diff --git a/src/bin/lttng-sessiond/kernel.c b/src/bin/lttng-sessiond/kernel.c
index 158a12a36..fc817b2db 100644
--- a/src/bin/lttng-sessiond/kernel.c
+++ b/src/bin/lttng-sessiond/kernel.c
@@ -33,6 +33,7 @@
 #include "kernel-consumer.h"
 #include "kern-modules.h"
 #include "utils.h"
+#include "rotate.h"
 
 /*
  * Key used to reference a channel between the sessiond and the consumer. This
@@ -535,6 +536,7 @@ int kernel_open_metadata(struct ltt_kernel_session *session)
 	}
 
 	lkm->fd = ret;
+	lkm->key = ++next_kernel_channel_key;
 	/* Prevent fd duplication after execlp() */
 	ret = fcntl(lkm->fd, F_SETFD, FD_CLOEXEC);
 	if (ret < 0) {
@@ -988,6 +990,8 @@ int kernel_snapshot_record(struct ltt_kernel_session *ksess,
 	struct consumer_socket *socket;
 	struct lttng_ht_iter iter;
 	struct ltt_kernel_metadata *saved_metadata;
+	struct ltt_session *session;
+	uint64_t trace_archive_id;
 
 	assert(ksess);
 	assert(ksess->consumer);
@@ -995,6 +999,12 @@ int kernel_snapshot_record(struct ltt_kernel_session *ksess,
 
 	DBG("Kernel snapshot record started");
 
+	session = session_find_by_id(ksess->id);
+	assert(session);
+	assert(pthread_mutex_trylock(&session->lock));
+	assert(session_trylock_list());
+	trace_archive_id = session->current_archive_id;
+
 	/* Save current metadata since the following calls will change it. */
 	saved_metadata = ksess->metadata;
 	saved_metadata_fd = ksess->metadata_stream_fd;
@@ -1042,7 +1052,8 @@ int kernel_snapshot_record(struct ltt_kernel_session *ksess,
 			ret = consumer_snapshot_channel(socket, chan->key, output, 0,
 					ksess->uid, ksess->gid,
 					DEFAULT_KERNEL_TRACE_DIR, wait,
-					nb_packets_per_stream);
+					nb_packets_per_stream,
+					trace_archive_id);
 			if (ret < 0) {
 				ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
 				(void) kernel_consumer_destroy_metadata(socket,
@@ -1052,9 +1063,10 @@ int kernel_snapshot_record(struct ltt_kernel_session *ksess,
 		}
 
 		/* Snapshot metadata, */
-		ret = consumer_snapshot_channel(socket, ksess->metadata->fd, output,
+		ret = consumer_snapshot_channel(socket, ksess->metadata->key, output,
 				1, ksess->uid, ksess->gid,
-				DEFAULT_KERNEL_TRACE_DIR, wait, 0);
+				DEFAULT_KERNEL_TRACE_DIR, wait, 0,
+				trace_archive_id);
 		if (ret < 0) {
 			ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
 			goto error_consumer;
@@ -1132,3 +1144,88 @@ int kernel_supports_ring_buffer_snapshot_sample_positions(int tracer_fd)
 error:
 	return ret;
 }
+
+/*
+ * Rotate a kernel session.
+ *
+ * Return 0 on success or else return a LTTNG_ERR code.
+ */
+int kernel_rotate_session(struct ltt_session *session)
+{
+	int ret;
+	struct consumer_socket *socket;
+	struct lttng_ht_iter iter;
+	struct ltt_kernel_session *ksess = session->kernel_session;
+
+	assert(ksess);
+	assert(ksess->consumer);
+
+	DBG("Rotate kernel session %s started (session %" PRIu64 ")",
+			session->name, session->id);
+
+	rcu_read_lock();
+
+	/*
+	 * 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;
+
+		/*
+		 * Account the metadata channel first to make sure the
+		 * number of channels waiting for a rotation cannot
+		 * reach 0 before we complete the iteration over all
+		 * the channels.
+		 */
+		ret = rotate_add_channel_pending(ksess->metadata->key,
+				LTTNG_DOMAIN_KERNEL, session);
+		if (ret < 0) {
+			ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
+			goto error;
+		}
+
+		/* For each channel, ask the consumer to rotate it. */
+		cds_list_for_each_entry(chan, &ksess->channel_list.head, list) {
+			ret = rotate_add_channel_pending(chan->key,
+					LTTNG_DOMAIN_KERNEL, session);
+			if (ret < 0) {
+				ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
+				goto error;
+			}
+
+			DBG("Rotate channel %" PRIu64 ", session %s", chan->key, session->name);
+			ret = consumer_rotate_channel(socket, chan->key,
+					ksess->uid, ksess->gid, ksess->consumer,
+					ksess->consumer->subdir,
+					/* is_metadata_channel */ false,
+					session->current_archive_id,
+					&session->rotate_pending_relay);
+			if (ret < 0) {
+				ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
+				goto error;
+			}
+		}
+
+		/*
+		 * Rotate the metadata channel.
+		 */
+		ret = consumer_rotate_channel(socket, ksess->metadata->key,
+				ksess->uid, ksess->gid, ksess->consumer,
+				ksess->consumer->subdir,
+				/* is_metadata_channel */ true,
+				session->current_archive_id,
+				&session->rotate_pending_relay);
+		if (ret < 0) {
+			ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
+			goto error;
+		}
+	}
+
+	ret = LTTNG_OK;
+
+error:
+	rcu_read_unlock();
+	return ret;
+}