Fix: put subbuffer back in kernel snapshot error path

[lttng-tools.git] / src / common / kernel-consumer / kernel-consumer.c

diff --git a/src/common/kernel-consumer/kernel-consumer.c b/src/common/kernel-consumer/kernel-consumer.c
index 5b05d9f6b6d4e9d9b0c588700def21dc5fa06cfe..a68438253c9d694a6d29d7267b1da50548ad4172 100644 (file)
--- a/src/common/kernel-consumer/kernel-consumer.c
+++ b/src/common/kernel-consumer/kernel-consumer.c
@@ -204,6 +204,10 @@ int lttng_kconsumer_snapshot_channel(uint64_t key, char *path,
                 */
                pthread_mutex_lock(&stream->lock);
 
+               /*
+                * Assign the received relayd ID so we can use it for streaming. The streams
+                * are not visible to anyone so this is OK to change it.
+                */
                stream->net_seq_idx = relayd_id;
                channel->relayd_id = relayd_id;
                if (relayd_id != (uint64_t) -1ULL) {
@@ -282,22 +286,21 @@ int lttng_kconsumer_snapshot_channel(uint64_t key, char *path,
                        ret = kernctl_get_subbuf_size(stream->wait_fd, &len);
                        if (ret < 0) {
                                ERR("Snapshot kernctl_get_subbuf_size");
-                               goto end_unlock;
+                               goto error_put_subbuf;
                        }
 
                        ret = kernctl_get_padded_subbuf_size(stream->wait_fd, &padded_len);
                        if (ret < 0) {
                                ERR("Snapshot kernctl_get_padded_subbuf_size");
-                               goto end_unlock;
+                               goto error_put_subbuf;
                        }
 
                        read_len = lttng_consumer_on_read_subbuffer_mmap(ctx, stream, len,
                                        padded_len - len);
                        /*
-                        * We write the padded len in local tracefiles but the
-                        * data len when using a relay.
-                        * Display the error but continue processing to try to
-                        * release the subbuffer.
+                        * We write the padded len in local tracefiles but the data len
+                        * when using a relay. Display the error but continue processing
+                        * to try to release the subbuffer.
                         */
                        if (relayd_id != (uint64_t) -1ULL) {
                                if (read_len != len) {
@@ -337,6 +340,11 @@ int lttng_kconsumer_snapshot_channel(uint64_t key, char *path,
        ret = 0;
        goto end;
 
+error_put_subbuf:
+       ret = kernctl_put_subbuf(stream->wait_fd);
+       if (ret < 0) {
+               ERR("Snapshot kernctl_put_subbuf error path");
+       }
 end_unlock:
        pthread_mutex_unlock(&stream->lock);
 end:
@@ -664,9 +672,9 @@ int lttng_kconsumer_recv_cmd(struct lttng_consumer_local_data *ctx,
 
                /* Do not monitor this stream. */
                if (!channel->monitor) {
-                       DBG("Kernel consumer add stream %s in no monitor mode with"
+                       DBG("Kernel consumer add stream %s in no monitor mode with "
                                        "relayd id %" PRIu64, new_stream->name,
-                                       new_stream->relayd_stream_id);
+                                       new_stream->net_seq_idx);
                        cds_list_add(&new_stream->no_monitor_node,
                                        &channel->stream_no_monitor_list.head);
                        break;