X-Git-Url: http://git.efficios.com/?a=blobdiff_plain;f=src%2Fbin%2Flttng-sessiond%2Fkernel.c;h=3ed65a83b206c2f3c6c374e031a428023305c80c;hb=4e52320d2950b79dc3ce537c32882c26f8c13846;hp=4327db24bdb3291f575da0d90c143e280c7bdbfa;hpb=d5a1b7aa06b4c924b1cd30623758343c74ecab5c;p=lttng-tools.git

diff --git a/src/bin/lttng-sessiond/kernel.c b/src/bin/lttng-sessiond/kernel.c
index 4327db24b..3ed65a83b 100644
--- a/src/bin/lttng-sessiond/kernel.c
+++ b/src/bin/lttng-sessiond/kernel.c
@@ -1233,17 +1233,18 @@ void kernel_destroy_channel(struct ltt_kernel_channel *kchan)
 /*
  * Take a snapshot for a given kernel session.
  *
- * Return 0 on success or else return a LTTNG_ERR code.
+ * Return LTTNG_OK on success or else return a LTTNG_ERR code.
  */
-int kernel_snapshot_record(struct ltt_kernel_session *ksess,
+enum lttng_error_code kernel_snapshot_record(struct ltt_kernel_session *ksess,
 		struct snapshot_output *output, int wait,
 		uint64_t nb_packets_per_stream)
 {
 	int err, ret, saved_metadata_fd;
+	enum lttng_error_code status = LTTNG_OK;
 	struct consumer_socket *socket;
 	struct lttng_ht_iter iter;
 	struct ltt_kernel_metadata *saved_metadata;
-	struct ltt_session *session;
+	struct ltt_session *session = NULL;
 	uint64_t trace_archive_id;
 
 	assert(ksess);
@@ -1266,13 +1267,13 @@ int kernel_snapshot_record(struct ltt_kernel_session *ksess,
 
 	ret = kernel_open_metadata(ksess);
 	if (ret < 0) {
-		ret = LTTNG_ERR_KERN_META_FAIL;
+		status = LTTNG_ERR_KERN_META_FAIL;
 		goto error;
 	}
 
 	ret = kernel_open_metadata_stream(ksess);
 	if (ret < 0) {
-		ret = LTTNG_ERR_KERN_META_FAIL;
+		status = LTTNG_ERR_KERN_META_FAIL;
 		goto error_open_stream;
 	}
 
@@ -1296,19 +1297,18 @@ int kernel_snapshot_record(struct ltt_kernel_session *ksess,
 		/* Put back the saved consumer output into the session. */
 		ksess->consumer = saved_output;
 		if (ret < 0) {
-			ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
+			status = LTTNG_ERR_KERN_CONSUMER_FAIL;
 			goto error_consumer;
 		}
 
 		/* For each channel, ask the consumer to snapshot it. */
 		cds_list_for_each_entry(chan, &ksess->channel_list.head, list) {
-			ret = consumer_snapshot_channel(socket, chan->key, output, 0,
+			status = consumer_snapshot_channel(socket, chan->key, output, 0,
 					ksess->uid, ksess->gid,
 					DEFAULT_KERNEL_TRACE_DIR, wait,
 					nb_packets_per_stream,
 					trace_archive_id);
-			if (ret < 0) {
-				ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
+			if (status != LTTNG_OK) {
 				(void) kernel_consumer_destroy_metadata(socket,
 						ksess->metadata);
 				goto error_consumer;
@@ -1316,12 +1316,11 @@ int kernel_snapshot_record(struct ltt_kernel_session *ksess,
 		}
 
 		/* Snapshot metadata, */
-		ret = consumer_snapshot_channel(socket, ksess->metadata->key, output,
+		status = consumer_snapshot_channel(socket, ksess->metadata->key, output,
 				1, ksess->uid, ksess->gid,
 				DEFAULT_KERNEL_TRACE_DIR, wait, 0,
 				trace_archive_id);
-		if (ret < 0) {
-			ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
+		if (status != LTTNG_OK) {
 			goto error_consumer;
 		}
 
@@ -1332,8 +1331,6 @@ int kernel_snapshot_record(struct ltt_kernel_session *ksess,
 		(void) kernel_consumer_destroy_metadata(socket, ksess->metadata);
 	}
 
-	ret = LTTNG_OK;
-
 error_consumer:
 	/* Close newly opened metadata stream. It's now on the consumer side. */
 	err = close(ksess->metadata_stream_fd);
@@ -1347,9 +1344,11 @@ error:
 	/* Restore metadata state.*/
 	ksess->metadata = saved_metadata;
 	ksess->metadata_stream_fd = saved_metadata_fd;
-
+	if (session) {
+		session_put(session);
+	}
 	rcu_read_unlock();
-	return ret;
+	return status;
 }
 
 /*
@@ -1460,3 +1459,79 @@ error:
 	rcu_read_unlock();
 	return status;
 }
+
+/*
+ *  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();
+
+	/*
+	 * 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,
+					ksess->consumer);
+			if (ret < 0) {
+				goto error;
+			}
+		}
+
+		if (!ksess->metadata) {
+			/*
+			 * Nothing to do for the metadata.
+			 * This is a snpashot 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 rotation operation on it behind the scene.
+		 */
+		ret = consumer_clear_channel(socket, ksess->metadata->key,
+				ksess->consumer);
+		if (ret < 0) {
+			goto error;
+		}
+	}
+
+	goto end;
+error:
+	switch (-ret) {
+	case LTTCOMM_CONSUMERD_RELAYD_DISALLOW_CLEAR:
+	      status = LTTNG_ERR_CLEAR_RELAY_DISALLOW;
+	      break;
+	default:
+	      status = LTTNG_ERR_CLEAR_FAIL_CONSUMER;
+	      break;
+	}
+end:
+	rcu_read_unlock();
+	return status;
+}