Fix: no-output sessions do not enforce snapshot constraints

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

diff --git a/src/bin/lttng-sessiond/cmd.c b/src/bin/lttng-sessiond/cmd.c
index d3c8376be1a01cf691f4a02be1ffe93c09c4a6b0..9cbadc6dde53fd16afde8b7a31cd6c4b15ac39cf 100644 (file)
--- a/src/bin/lttng-sessiond/cmd.c
+++ b/src/bin/lttng-sessiond/cmd.c
@@ -1523,6 +1523,11 @@ int cmd_enable_channel(struct ltt_session *session,
                kchan = trace_kernel_get_channel_by_name(attr->name,
                                session->kernel_session);
                if (kchan == NULL) {
+                       if (session->snapshot.nb_output > 0 ||
+                                       session->snapshot_mode) {
+                               /* Enforce mmap output for snapshot sessions. */
+                               attr->attr.output = LTTNG_EVENT_MMAP;
+                       }
                        ret = channel_kernel_create(session->kernel_session, attr, wpipe);
                        if (attr->name[0] != '\0') {
                                session->kernel_session->has_non_default_channel = 1;
@@ -1591,6 +1596,9 @@ int cmd_enable_channel(struct ltt_session *session,
                goto error;
        }
 
+       if (ret == LTTNG_OK && attr->attr.output != LTTNG_EVENT_MMAP) {
+               session->has_non_mmap_channel = true;
+       }
 error:
        rcu_read_unlock();
 end:
@@ -3548,6 +3556,11 @@ int cmd_snapshot_add_output(struct ltt_session *session,
                goto error;
        }
 
+       if (session->has_non_mmap_channel) {
+               ret = LTTNG_ERR_SNAPSHOT_UNSUPPORTED;
+               goto error;
+       }
+
        /* Only one output is allowed until we have the "tee" feature. */
        if (session->snapshot.nb_output == 1) {
                ret = LTTNG_ERR_SNAPSHOT_OUTPUT_EXIST;
@@ -4179,10 +4192,13 @@ static enum lttng_error_code record_ust_snapshot(struct ltt_ust_session *usess,
                goto error_snapshot;
        }
 
+       goto end;
+
 error_snapshot:
        /* Clean up copied sockets so this output can use some other later on. */
        consumer_destroy_output_sockets(output->consumer);
 error:
+end:
        return status;
 }
 
@@ -4496,8 +4512,7 @@ int cmd_rotate_session(struct ltt_session *session,
                goto end;
        }
 
-       if (session->live_timer || session->snapshot_mode ||
-                       !session->output_traces) {
+       if (session->live_timer || !session->output_traces) {
                cmd_ret = LTTNG_ERR_ROTATION_NOT_AVAILABLE;
                goto end;
        }
@@ -4846,8 +4861,7 @@ int cmd_rotation_set_schedule(struct ltt_session *session,
 
        DBG("Cmd rotate set schedule session %s", session->name);
 
-       if (session->live_timer || session->snapshot_mode ||
-                       !session->output_traces) {
+       if (session->live_timer || !session->output_traces) {
                DBG("Failing ROTATION_SET_SCHEDULE command as the rotation feature is not available for this session");
                ret = LTTNG_ERR_ROTATION_NOT_AVAILABLE;
                goto end;