Sessiond: Implement cmd_clear_session

[lttng-tools.git] / src / bin / lttng-sessiond / kernel.c

diff --git a/src/bin/lttng-sessiond/kernel.c b/src/bin/lttng-sessiond/kernel.c
index 8e972b0693cc28362fe36e9a80b040d128bed62c..aac6665bef40a17021b03c88dc7f294be5e8553e 100644 (file)
--- a/src/bin/lttng-sessiond/kernel.c
+++ b/src/bin/lttng-sessiond/kernel.c
@@ -1459,3 +1459,70 @@ 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("Cleat 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;
+                       }
+               }
+
+               /*
+                * 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;
+}