Fix relayd: stream index file created in the wrong directory

[lttng-tools.git] / src / bin / lttng-relayd / main.c

diff --git a/src/bin/lttng-relayd/main.c b/src/bin/lttng-relayd/main.c
index cbe1a607c36add6e8b320f8f57c13a816a9b3dc5..cf6e01ee0ffd1409269ffc9cfc0f2dc662261d04 100644 (file)
--- a/src/bin/lttng-relayd/main.c
+++ b/src/bin/lttng-relayd/main.c
@@ -1539,7 +1539,8 @@ end:
  * Return 0 on success, -1 on error.
  */
 static
-int create_rotate_index_file(struct relay_stream *stream)
+int create_rotate_index_file(struct relay_stream *stream,
+               const char *stream_path)
 {
        int ret;
        uint32_t major, minor;
@@ -1551,7 +1552,7 @@ int create_rotate_index_file(struct relay_stream *stream)
        }
        major = stream->trace->session->major;
        minor = stream->trace->session->minor;
-       stream->index_file = lttng_index_file_create(stream->path_name,
+       stream->index_file = lttng_index_file_create(stream_path,
                        stream->channel_name,
                        -1, -1, stream->tracefile_size,
                        tracefile_array_get_file_index_head(stream->tfa),
@@ -1587,7 +1588,7 @@ int do_rotate_stream(struct relay_stream *stream)
 
        /* Rotate also the index if the stream is not a metadata stream. */
        if (!stream->is_metadata) {
-               ret = create_rotate_index_file(stream);
+               ret = create_rotate_index_file(stream, stream->path_name);
                if (ret < 0) {
                        ERR("Failed to rotate index file");
                        goto end;
@@ -1709,7 +1710,7 @@ int rotate_truncate_stream(struct relay_stream *stream)
                goto end;
        }
 
-       ret = create_rotate_index_file(stream);
+       ret = create_rotate_index_file(stream, stream->path_name);
        if (ret < 0) {
                ERR("Rotate stream index file");
                goto end;
@@ -2526,7 +2527,8 @@ static int relay_rotate_session_stream(const struct lttcomm_relayd_hdr *recv_hdr
         * Update the trace path (just the folder, the stream name does not
         * change).
         */
-       free(stream->path_name);
+       free(stream->prev_path_name);
+       stream->prev_path_name = stream->path_name;
        stream->path_name = create_output_path(new_path_view.data);
        if (!stream->path_name) {
                ERR("Failed to create a new output path");
@@ -3250,7 +3252,34 @@ static int handle_index_data(struct relay_stream *stream, uint64_t net_seq_num,
        }
 
        if (rotate_index || !stream->index_file) {
-               ret = create_rotate_index_file(stream);
+               const char *stream_path;
+
+               /*
+                * The data connection creates the stream's first index file.
+                *
+                * This can happen _after_ a ROTATE_STREAM command. In
+                * other words, the data of the first packet of this stream
+                * can be received after a ROTATE_STREAM command.
+                *
+                * The ROTATE_STREAM command changes the stream's path_name
+                * to point to the "next" chunk. If a rotation is pending for
+                * this stream, as indicated by "rotate_at_seq_num != -1ULL",
+                * it means that we are still receiving data that belongs in the
+                * stream's former path.
+                *
+                * In this very specific case, we must ensure that the index
+                * file is created in the streams's former path,
+                * "prev_path_name".
+                *
+                * All other rotations beyond the first one are not affected
+                * by this problem since the actual rotation operation creates
+                * the new chunk's index file.
+                */
+               stream_path = stream->rotate_at_seq_num == -1ULL ?
+                               stream->path_name:
+                               stream->prev_path_name;
+
+               ret = create_rotate_index_file(stream, stream_path);
                if (ret < 0) {
                        ERR("Failed to rotate index");
                        /* Put self-ref for this index due to error. */