X-Git-Url: https://git.liburcu.org/?a=blobdiff_plain;f=src%2Fbin%2Flttng-sessiond%2Fcmd.c;h=ae0a56ac67e0d249953ec39d28718323484dbbad;hb=6beb3779248926b2c75175b18e90ac883d528e3c;hp=3c59d092c2e9b0f2ca848277219091307b20c078;hpb=4f824676224a111d05ea7984492ad2a7f8abc430;p=lttng-tools.git

diff --git a/src/bin/lttng-sessiond/cmd.c b/src/bin/lttng-sessiond/cmd.c
index 3c59d092c..ae0a56ac6 100644
--- a/src/bin/lttng-sessiond/cmd.c
+++ b/src/bin/lttng-sessiond/cmd.c
@@ -277,7 +277,10 @@ static void list_lttng_channels(enum lttng_domain_type domain,
 				&iter.iter, uchan, node.node) {
 			uint64_t discarded_events = 0, lost_packets = 0;
 
-			strncpy(channels[i].name, uchan->name, LTTNG_SYMBOL_NAME_LEN);
+			if (lttng_strncpy(channels[i].name, uchan->name,
+					LTTNG_SYMBOL_NAME_LEN)) {
+				break;
+			}
 			channels[i].attr.overwrite = uchan->attr.overwrite;
 			channels[i].attr.subbuf_size = uchan->attr.subbuf_size;
 			channels[i].attr.num_subbuf = uchan->attr.num_subbuf;
@@ -1330,16 +1333,6 @@ int cmd_enable_channel(struct ltt_session *session,
 		attr->attr.switch_timer_interval = 0;
 	}
 
-	/*
-	 * The ringbuffer (both in user space and kernel) behave badly in overwrite
-	 * mode and with less than 2 subbuf so block it right away and send back an
-	 * invalid attribute error.
-	 */
-	if (attr->attr.overwrite && attr->attr.num_subbuf < 2) {
-		ret = LTTNG_ERR_INVALID;
-		goto error;
-	}
-
 	switch (domain->type) {
 	case LTTNG_DOMAIN_KERNEL:
 	{
@@ -2444,7 +2437,15 @@ int cmd_stop_trace(struct ltt_session *session)
 	if (ksession && ksession->active) {
 		DBG("Stop kernel tracing");
 
-		/* Flush metadata if exist */
+		ret = kernel_stop_session(ksession);
+		if (ret < 0) {
+			ret = LTTNG_ERR_KERN_STOP_FAIL;
+			goto error;
+		}
+
+		kernel_wait_quiescent(kernel_tracer_fd);
+
+		/* Flush metadata after stopping (if exists) */
 		if (ksession->metadata_stream_fd >= 0) {
 			ret = kernel_metadata_flush_buffer(ksession->metadata_stream_fd);
 			if (ret < 0) {
@@ -2452,7 +2453,7 @@ int cmd_stop_trace(struct ltt_session *session)
 			}
 		}
 
-		/* Flush all buffers before stopping */
+		/* Flush all buffers after stopping */
 		cds_list_for_each_entry(kchan, &ksession->channel_list.head, list) {
 			ret = kernel_flush_buffer(kchan);
 			if (ret < 0) {
@@ -2460,14 +2461,6 @@ int cmd_stop_trace(struct ltt_session *session)
 			}
 		}
 
-		ret = kernel_stop_session(ksession);
-		if (ret < 0) {
-			ret = LTTNG_ERR_KERN_STOP_FAIL;
-			goto error;
-		}
-
-		kernel_wait_quiescent(kernel_tracer_fd);
-
 		ksession->active = 0;
 	}
 
@@ -3359,14 +3352,14 @@ ssize_t cmd_snapshot_list_outputs(struct ltt_session *session,
 		if (lttng_strncpy(list[idx].name, output->name,
 				sizeof(list[idx].name))) {
 			ret = -LTTNG_ERR_INVALID;
-			goto error;
+			goto error_unlock;
 		}
 		if (output->consumer->type == CONSUMER_DST_LOCAL) {
 			if (lttng_strncpy(list[idx].ctrl_url,
 					output->consumer->dst.trace_path,
 					sizeof(list[idx].ctrl_url))) {
 				ret = -LTTNG_ERR_INVALID;
-				goto error;
+				goto error_unlock;
 			}
 		} else {
 			/* Control URI. */
@@ -3374,7 +3367,7 @@ ssize_t cmd_snapshot_list_outputs(struct ltt_session *session,
 					list[idx].ctrl_url, sizeof(list[idx].ctrl_url));
 			if (ret < 0) {
 				ret = -LTTNG_ERR_NOMEM;
-				goto error;
+				goto error_unlock;
 			}
 
 			/* Data URI. */
@@ -3382,7 +3375,7 @@ ssize_t cmd_snapshot_list_outputs(struct ltt_session *session,
 					list[idx].data_url, sizeof(list[idx].data_url));
 			if (ret < 0) {
 				ret = -LTTNG_ERR_NOMEM;
-				goto error;
+				goto error_unlock;
 			}
 		}
 		idx++;
@@ -3391,9 +3384,10 @@ ssize_t cmd_snapshot_list_outputs(struct ltt_session *session,
 	*outputs = list;
 	list = NULL;
 	ret = session->snapshot.nb_output;
+error_unlock:
+	rcu_read_unlock();
 error:
 	free(list);
-	rcu_read_unlock();
 	return ret;
 }
 
@@ -3442,6 +3436,27 @@ end:
 	return ret;
 }
 
+static
+int clear_metadata_file(int fd)
+{
+	int ret;
+
+	ret = lseek(fd, 0, SEEK_SET);
+	if (ret < 0) {
+		PERROR("lseek");
+		goto end;
+	}
+
+	ret = ftruncate(fd, 0);
+	if (ret < 0) {
+		PERROR("ftruncate");
+		goto end;
+	}
+
+end:
+	return ret;
+}
+
 static
 int ust_metadata_regenerate(struct ltt_ust_session *usess)
 {
@@ -3463,6 +3478,15 @@ int ust_metadata_regenerate(struct ltt_ust_session *usess)
 		memset(registry->metadata, 0, registry->metadata_alloc_len);
 		registry->metadata_len = 0;
 		registry->metadata_version++;
+		if (registry->metadata_fd > 0) {
+			/* Clear the metadata file's content. */
+			ret = clear_metadata_file(registry->metadata_fd);
+			if (ret) {
+				pthread_mutex_unlock(&registry->lock);
+				goto end;
+			}
+		}
+
 		ret = ust_metadata_session_statedump(registry, NULL,
 				registry->major, registry->minor);
 		if (ret) {