Fix: kernel/ust snapshot backward compat for 2.10 relay

[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 c395f425542abe4bffe9f6ecfcf28a6f97e67be0..53072f97187654dc37db1b6042f8100b375cbb70 100644 (file)
--- a/src/bin/lttng-sessiond/kernel.c
+++ b/src/bin/lttng-sessiond/kernel.c
@@ -131,6 +131,7 @@ int kernel_create_session(struct ltt_session *session, int tracer_fd)
 error:
        if (lks) {
                trace_kernel_destroy_session(lks);
+               trace_kernel_free_session(lks);
        }
        return ret;
 }
@@ -1156,7 +1157,7 @@ end_boot_id:
 }
 
 /*
- * Complete teardown of a kernel session.
+ * Teardown of a kernel session, keeping data required by destroy notifiers.
  */
 void kernel_destroy_session(struct ltt_kernel_session *ksess)
 {
@@ -1205,6 +1206,15 @@ void kernel_destroy_session(struct ltt_kernel_session *ksess)
        lttng_trace_chunk_put(trace_chunk);
 }
 
+/* Teardown of data required by destroy notifiers. */
+void kernel_free_session(struct ltt_kernel_session *ksess)
+{
+       if (ksess == NULL) {
+               return;
+       }
+       trace_kernel_free_session(ksess);
+}
+
 /*
  * Destroy a kernel channel object. It does not do anything on the tracer side.
  */
@@ -1242,7 +1252,7 @@ void kernel_destroy_channel(struct ltt_kernel_channel *kchan)
  */
 enum lttng_error_code kernel_snapshot_record(
                struct ltt_kernel_session *ksess,
-               const struct snapshot_output *output, int wait,
+               const struct consumer_output *output, int wait,
                uint64_t nb_packets_per_stream)
 {
        int err, ret, saved_metadata_fd;
@@ -1250,6 +1260,7 @@ enum lttng_error_code kernel_snapshot_record(
        struct consumer_socket *socket;
        struct lttng_ht_iter iter;
        struct ltt_kernel_metadata *saved_metadata;
+       char *trace_path = NULL;
 
        assert(ksess);
        assert(ksess->consumer);
@@ -1275,25 +1286,21 @@ enum lttng_error_code kernel_snapshot_record(
                goto error_open_stream;
        }
 
+       trace_path = setup_channel_trace_path(ksess->consumer,
+                       DEFAULT_KERNEL_TRACE_DIR);
+       if (!trace_path) {
+               status = LTTNG_ERR_INVALID;
+               goto error;
+       }
        /* Send metadata to consumer and snapshot everything. */
-       cds_lfht_for_each_entry(ksess->consumer->socks->ht, &iter.iter,
+       cds_lfht_for_each_entry(output->socks->ht, &iter.iter,
                        socket, node.node) {
-               struct consumer_output *saved_output;
                struct ltt_kernel_channel *chan;
 
-               /*
-                * Temporarly switch consumer output for our snapshot output. As long
-                * as the session lock is taken, this is safe.
-                */
-               saved_output = ksess->consumer;
-               ksess->consumer = output->consumer;
-
                pthread_mutex_lock(socket->lock);
                /* This stream must not be monitored by the consumer. */
                ret = kernel_consumer_add_metadata(socket, ksess, 0);
                pthread_mutex_unlock(socket->lock);
-               /* Put back the saved consumer output into the session. */
-               ksess->consumer = saved_output;
                if (ret < 0) {
                        status = LTTNG_ERR_KERN_META_FAIL;
                        goto error_consumer;
@@ -1303,7 +1310,7 @@ enum lttng_error_code kernel_snapshot_record(
                cds_list_for_each_entry(chan, &ksess->channel_list.head, list) {
                        status = consumer_snapshot_channel(socket, chan->key, output, 0,
                                        ksess->uid, ksess->gid,
-                                       DEFAULT_KERNEL_TRACE_DIR, wait,
+                                       trace_path, wait,
                                        nb_packets_per_stream);
                        if (status != LTTNG_OK) {
                                (void) kernel_consumer_destroy_metadata(socket,
@@ -1314,8 +1321,7 @@ enum lttng_error_code kernel_snapshot_record(
 
                /* Snapshot metadata, */
                status = consumer_snapshot_channel(socket, ksess->metadata->key, output,
-                               1, ksess->uid, ksess->gid,
-                               DEFAULT_KERNEL_TRACE_DIR, wait, 0);
+                               1, ksess->uid, ksess->gid, trace_path, wait, 0);
                if (status != LTTNG_OK) {
                        goto error_consumer;
                }
@@ -1341,6 +1347,7 @@ error:
        ksess->metadata = saved_metadata;
        ksess->metadata_stream_fd = saved_metadata_fd;
        rcu_read_unlock();
+       free(trace_path);
        return status;
 }