Fix: do not return error on LTTNG_ERR_SNAPSHOT_NODATA

A warning is fine since the user has no control on
whether or not applications (or the kernel) have
produced any event between the start of the tracing
session and the recording of the snapshot.

MI wise the command is not a success since nothing was
recorded. The command line return code is CMD_SUCCESS.

refs #1002

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

diff --git a/src/bin/lttng/commands/snapshot.c b/src/bin/lttng/commands/snapshot.c
index abdf1890198b1653a2a3a2ab0bc5bc0599d584aa..298bc6ef36cee6a1bac7cb362464c0dd22f9915c 100644 (file)
--- a/src/bin/lttng/commands/snapshot.c
+++ b/src/bin/lttng/commands/snapshot.c
@@ -725,6 +725,15 @@ int cmd_snapshot(int argc, const char **argv)
                        break;
                case LTTNG_ERR_SNAPSHOT_NODATA:
                        WARN("%s", lttng_strerror(command_ret));
+
+                       /*  A warning is fine since the user has no control on
+                        *  whether or not applications (or the kernel) have
+                        *  produced any event between the start of the tracing
+                        *  session and the recording of the snapshot. MI wise
+                        *  the command is not a success since nothing was
+                        *  recorded.
+                        */
+                       command_ret = 0;
                        break;
                default:
                        ERR("%s", lttng_strerror(command_ret));