Fix: put subbuffer back in kernel snapshot error path

Signed-off-by: David Goulet <dgoulet@efficios.com>

diff --git a/src/common/kernel-consumer/kernel-consumer.c b/src/common/kernel-consumer/kernel-consumer.c
index a0818452f4f540ef880a3effb13c0e2b89fc0e10..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: