X-Git-Url: https://git.liburcu.org/?a=blobdiff_plain;f=src%2Fbin%2Flttng-sessiond%2Fcmd.c;h=ae0a56ac67e0d249953ec39d28718323484dbbad;hb=6beb3779248926b2c75175b18e90ac883d528e3c;hp=cc26e6dae004baeab4177f3589a0e837e7deba34;hpb=019e9d1b3f94f345fd7a5275ce712302ae5715d8;p=lttng-tools.git

diff --git a/src/bin/lttng-sessiond/cmd.c b/src/bin/lttng-sessiond/cmd.c
index cc26e6dae..ae0a56ac6 100644
--- a/src/bin/lttng-sessiond/cmd.c
+++ b/src/bin/lttng-sessiond/cmd.c
@@ -1333,16 +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:
 	{
@@ -3362,14 +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. */
@@ -3377,7 +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. */
@@ -3385,7 +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++;
@@ -3394,9 +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;
 }
 
@@ -3445,6 +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)
 {
@@ -3466,6 +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) {