X-Git-Url: http://git.efficios.com/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fbin%2Flttng-sessiond%2Fkernel.c;h=ccf315d8901efdcb2e04e50a4de9e85e1073bca2;hp=e5f068a0cd9515408a34b4621201e8b75f714a81;hb=5c408ad8ef08a226c018702aca969536f36ac4e5;hpb=d086f507d02078aed618ab291a0bc4a634958fa3

diff --git a/src/bin/lttng-sessiond/kernel.c b/src/bin/lttng-sessiond/kernel.c
index e5f068a0c..ccf315d89 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
@@ -1133,3 +1134,88 @@ 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->fd,
+				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->rotate_count,
+					&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->fd,
+				ksess->uid, ksess->gid, ksess->consumer,
+				ksess->consumer->subdir,
+				/* is_metadata_channel */ true,
+				session->rotate_count,
+				&session->rotate_pending_relay);
+		if (ret < 0) {
+			ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
+			goto error;
+		}
+	}
+
+	ret = LTTNG_OK;
+
+error:
+	rcu_read_unlock();
+	return ret;
+}