+ return ret;
+}
+
+/*
+ * Command LTTNG_SET_SESSION_SHM_PATH processed by the client thread.
+ */
+int cmd_set_session_shm_path(struct ltt_session *session,
+ const char *shm_path)
+{
+ /* Safety net */
+ assert(session);
+
+ /*
+ * Can only set shm path before session is started.
+ */
+ if (session->has_been_started) {
+ return LTTNG_ERR_SESSION_STARTED;
+ }
+
+ strncpy(session->shm_path, shm_path,
+ sizeof(session->shm_path));
+ session->shm_path[sizeof(session->shm_path) - 1] = '\0';
+
+ return 0;
+}
+
+/*
+ * Command LTTNG_ROTATE_SESSION from the lttng-ctl library.
+ *
+ * Ask the consumer to rotate the session output directory.
+ * The session lock must be held.
+ *
+ * Return LTTNG_OK on success or else a LTTNG_ERR code.
+ */
+int cmd_rotate_session(struct ltt_session *session,
+ struct lttng_rotate_session_return *rotate_return)
+{
+ int ret;
+ size_t strf_ret;
+ struct tm *timeinfo;
+ char datetime[16];
+ time_t now;
+ bool ust_active = false;
+
+ assert(session);
+
+ if (!session->has_been_started) {
+ ret = -LTTNG_ERR_START_SESSION_ONCE;
+ goto end;
+ }
+
+ if (session->live_timer || session->snapshot_mode ||
+ !session->output_traces) {
+ ret = -LTTNG_ERR_ROTATION_NOT_AVAILABLE;
+ goto end;
+ }
+
+ /*
+ * Unsupported feature in lttng-relayd before 2.11.
+ */
+ if (session->consumer->type == CONSUMER_DST_NET &&
+ (session->consumer->relay_major_version == 2 &&
+ session->consumer->relay_minor_version < 11)) {
+ ret = -LTTNG_ERR_ROTATION_NOT_AVAILABLE;
+ goto end;
+ }
+
+ if (session->rotate_pending || session->rotate_pending_relay) {
+ ret = -LTTNG_ERR_ROTATION_PENDING;
+ DBG("Rotate already in progress");
+ goto end;
+ }
+
+ /*
+ * After a stop, we only allow one rotation to occur, the other ones are
+ * useless until a new start.
+ */
+ if (session->rotated_after_last_stop) {
+ DBG("Session \"%s\" was already rotated after stop, refusing rotation",
+ session->name);
+ ret = -LTTNG_ERR_ROTATION_MULTIPLE_AFTER_STOP;
+ goto end;
+ }
+
+ /* Special case for the first rotation. */
+ if (session->rotate_count == 0) {
+ const char *base_path = NULL;
+
+ /* Either one of the two sessions is enough to get the root path. */
+ if (session->kernel_session) {
+ base_path = session_get_base_path(session);
+ } else if (session->ust_session) {
+ base_path = session_get_base_path(session);
+ } else {
+ assert(0);
+ }
+ assert(base_path);
+ ret = lttng_strncpy(session->rotation_chunk.current_rotate_path,
+ base_path,
+ sizeof(session->rotation_chunk.current_rotate_path));
+ if (ret) {
+ ERR("Failed to copy session base path to current rotation chunk path");
+ ret = -LTTNG_ERR_UNK;
+ goto end;
+ }
+ } else {
+ /*
+ * The currently active tracing path is now the folder we
+ * want to rotate.
+ */
+ ret = lttng_strncpy(session->rotation_chunk.current_rotate_path,
+ session->rotation_chunk.active_tracing_path,
+ sizeof(session->rotation_chunk.current_rotate_path));
+ if (ret) {
+ ERR("Failed to copy the active tracing path to the current rotate path");
+ ret = -LTTNG_ERR_UNK;
+ goto end;
+ }
+ }
+ DBG("Current rotate path %s", session->rotation_chunk.current_rotate_path);
+
+ session->rotate_count++;
+ session->rotate_pending = true;
+ session->rotation_state = LTTNG_ROTATION_STATE_ONGOING;
+
+ /*
+ * Create the path name for the next chunk.
+ */
+ now = time(NULL);
+ if (now == (time_t) -1) {
+ ret = -LTTNG_ERR_ROTATION_NOT_AVAILABLE;
+ goto end;
+ }
+ session->last_chunk_start_ts = session->current_chunk_start_ts;
+ session->current_chunk_start_ts = now;
+
+ timeinfo = localtime(&now);
+ if (!timeinfo) {
+ PERROR("Failed to sample local time in rotate session command");
+ ret = -LTTNG_ERR_UNK;
+ goto end;
+ }
+ strf_ret = strftime(datetime, sizeof(datetime), "%Y%m%d-%H%M%S",
+ timeinfo);
+ if (!strf_ret) {
+ ERR("Failed to format local time timestamp in rotate session command");
+ ret = -LTTNG_ERR_UNK;
+ goto end;
+ }
+ if (session->kernel_session) {
+ /*
+ * The active path for the next rotation/destroy.
+ * Ex: ~/lttng-traces/auto-20170922-111748/20170922-111754-42
+ */
+ ret = snprintf(session->rotation_chunk.active_tracing_path,
+ sizeof(session->rotation_chunk.active_tracing_path),
+ "%s/%s-%" PRIu64,
+ session_get_base_path(session),
+ datetime, session->rotate_count + 1);
+ if (ret < 0 || ret == sizeof(session->rotation_chunk.active_tracing_path)) {
+ ERR("Failed to format active kernel tracing path in rotate session command");
+ ret = -LTTNG_ERR_UNK;
+ goto end;
+ }
+ /*
+ * The sub-directory for the consumer
+ * Ex: /20170922-111754-42/kernel
+ */
+ ret = snprintf(session->kernel_session->consumer->chunk_path,
+ sizeof(session->kernel_session->consumer->chunk_path),
+ "/%s-%" PRIu64, datetime,
+ session->rotate_count + 1);
+ if (ret < 0 || ret == sizeof(session->kernel_session->consumer->chunk_path)) {
+ ERR("Failed to format the kernel consumer's sub-directory in rotate session command");
+ ret = -LTTNG_ERR_UNK;
+ goto end;
+ }
+ /*
+ * Create the new chunk folder, before the rotation begins so we don't
+ * race with the consumer/tracer activity.
+ */
+ ret = domain_mkdir(session->kernel_session->consumer, session,
+ session->kernel_session->uid,
+ session->kernel_session->gid);
+ if (ret) {
+ ERR("Failed to create kernel session tracing path at %s",
+ session->kernel_session->consumer->chunk_path);
+ ret = -LTTNG_ERR_CREATE_DIR_FAIL;
+ goto end;
+ }
+ ret = kernel_rotate_session(session);
+ if (ret != LTTNG_OK) {
+ ret = -ret;
+ goto end;
+ }
+ }
+ if (session->ust_session) {
+ ret = snprintf(session->rotation_chunk.active_tracing_path,
+ PATH_MAX, "%s/%s-%" PRIu64,
+ session_get_base_path(session),
+ datetime, session->rotate_count + 1);
+ if (ret < 0) {
+ ERR("Failed to format active UST tracing path in rotate session command");
+ ret = -LTTNG_ERR_UNK;
+ goto end;
+ }
+ ret = snprintf(session->ust_session->consumer->chunk_path,
+ PATH_MAX, "/%s-%" PRIu64, datetime,
+ session->rotate_count + 1);
+ if (ret < 0) {
+ ERR("Failed to format the UST consumer's sub-directory in rotate session command");
+ ret = -LTTNG_ERR_UNK;
+ goto end;
+ }
+ /*
+ * Create the new chunk folder, before the rotation begins so we don't
+ * race with the consumer/tracer activity.
+ */
+ ret = domain_mkdir(session->ust_session->consumer, session,
+ session->ust_session->uid,
+ session->ust_session->gid);
+ ret = ust_app_rotate_session(session, &ust_active);
+ if (ret != LTTNG_OK) {
+ ret = -LTTNG_ERR_CREATE_DIR_FAIL;
+ goto end;
+ }
+ /*
+ * Handle the case where we did not start a rotation on any channel.
+ * The consumer will never wake up the rotation thread to perform the
+ * rename, so we have to do it here while we hold the session and
+ * session_list locks.
+ */
+ if (!session->kernel_session && !ust_active) {
+ ret = rename_complete_chunk(session, now);
+ if (ret < 0) {
+ ERR("Failed to rename completed rotation chunk");
+ goto end;
+ }
+ session->rotate_pending = false;
+ session->rotation_state = LTTNG_ROTATION_STATE_COMPLETED;
+ }
+ }
+
+ if (!session->active) {
+ session->rotated_after_last_stop = true;