X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fbin%2Flttng-sessiond%2Fkernel.c;h=19a325da1f1421b27c73bfb7866ae5204b87ca7b;hp=158a12a3633fa54100c81d0f5179b6c2c9d9c68e;hb=1fc1b7c8ac91a5d3a468ee64a862f4df9592b1c5;hpb=0a28e5534ea9d68c19c57f2453e789a7188e16b4

diff --git a/src/bin/lttng-sessiond/kernel.c b/src/bin/lttng-sessiond/kernel.c
index 158a12a36..19a325da1 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) {
@@ -1052,7 +1054,7 @@ 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);
 		if (ret < 0) {
@@ -1132,3 +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->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;
+}