Fix: propagate archive id to the consumer daemon on stream creation

[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 e5f068a0cd9515408a34b4621201e8b75f714a81..fc817b2db304187675a38e1c5d8904658fe670a5 100644 (file)
--- 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
@@ -989,6 +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);
@@ -996,6 +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;
@@ -1043,7 +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,
@@ -1055,7 +1065,8 @@ int kernel_snapshot_record(struct ltt_kernel_session *ksess,
                /* Snapshot metadata, */
                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;
@@ -1133,3 +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;
+}