Fix: consumer: Move sanity check within `consumer_subbuffer` functions

The sanity check on the number bytes written by the `consumer_subbuffer`
callback was not correct channel configured in the splice output type in
a live session.

To simplify this, move checks in the callback themselves so they can be
specialized.

Signed-off-by: Francis Deslauriers <francis.deslauriers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I4e47a305860684c461ba7ffffd5e3bb3a21990b0

diff --git a/src/common/consumer/consumer-stream.c b/src/common/consumer/consumer-stream.c
index 398d71ae05f92f6d9c0437b4fb203532870eb5d6..47f2eb2171fa2883d84ce8a7dfe8830fa10134fb 100644 (file)
--- a/src/common/consumer/consumer-stream.c
+++ b/src/common/consumer/consumer-stream.c
@@ -151,9 +151,40 @@ static ssize_t consumer_stream_consume_mmap(
        const unsigned long padding_size =
                        subbuffer->info.data.padded_subbuf_size -
                        subbuffer->info.data.subbuf_size;
-
-       return lttng_consumer_on_read_subbuffer_mmap(
+       const ssize_t written_bytes = lttng_consumer_on_read_subbuffer_mmap(
                        stream, &subbuffer->buffer.buffer, padding_size);
+
+       if (stream->net_seq_idx == -1ULL) {
+               /*
+                * When writing on disk, check that only the subbuffer (no
+                * padding) was written to disk.
+                */
+               if (written_bytes != subbuffer->info.data.padded_subbuf_size) {
+                       DBG("Failed to write the entire padded subbuffer on disk (written_bytes: %zd, padded subbuffer size %lu)",
+                                       written_bytes,
+                                       subbuffer->info.data.padded_subbuf_size);
+               }
+       } else {
+               /*
+                * When streaming over the network, check that the entire
+                * subbuffer including padding was successfully written.
+                */
+               if (written_bytes != subbuffer->info.data.subbuf_size) {
+                       DBG("Failed to write only the subbuffer over the network (written_bytes: %zd, subbuffer size %lu)",
+                                       written_bytes,
+                                       subbuffer->info.data.subbuf_size);
+               }
+       }
+
+       /*
+        * If `lttng_consumer_on_read_subbuffer_mmap()` returned an error, pass
+        * it along to the caller, else return zero.
+        */
+       if (written_bytes < 0) {
+               ERR("Error reading mmap subbuffer: %zd", written_bytes);
+       }
+
+       return written_bytes;
 }
 
 static ssize_t consumer_stream_consume_splice(
@@ -161,8 +192,24 @@ static ssize_t consumer_stream_consume_splice(
                struct lttng_consumer_stream *stream,
                const struct stream_subbuffer *subbuffer)
 {
-       return lttng_consumer_on_read_subbuffer_splice(ctx, stream,
-                       subbuffer->info.data.padded_subbuf_size, 0);
+       const ssize_t written_bytes = lttng_consumer_on_read_subbuffer_splice(
+                       ctx, stream, subbuffer->info.data.padded_subbuf_size, 0);
+
+       if (written_bytes != subbuffer->info.data.padded_subbuf_size) {
+               DBG("Failed to write the entire padded subbuffer (written_bytes: %zd, padded subbuffer size %lu)",
+                               written_bytes,
+                               subbuffer->info.data.padded_subbuf_size);
+       }
+
+       /*
+        * If `lttng_consumer_on_read_subbuffer_splice()` returned an error,
+        * pass it along to the caller, else return zero.
+        */
+       if (written_bytes < 0) {
+               ERR("Error reading splice subbuffer: %zd", written_bytes);
+       }
+
+       return written_bytes;
 }
 
 static int consumer_stream_send_index(

diff --git a/src/common/consumer/consumer.c b/src/common/consumer/consumer.c
index 093f957f2901ef6e9f543d0202b2b38f07b1cffc..782ace930c0f7c6cb4952c703202a8fcea4b5e1f 100644 (file)
--- a/src/common/consumer/consumer.c
+++ b/src/common/consumer/consumer.c
@@ -3500,24 +3500,10 @@ ssize_t lttng_consumer_read_subbuffer(struct lttng_consumer_stream *stream,
 
        written_bytes = stream->read_subbuffer_ops.consume_subbuffer(
                        ctx, stream, &subbuffer);
-       /*
-        * Should write subbuf_size amount of data when network streaming or
-        * the full padded size when we are not streaming.
-        */
-       if ((written_bytes != subbuffer.info.data.subbuf_size &&
-                           stream->net_seq_idx != (uint64_t) -1ULL) ||
-                       (written_bytes != subbuffer.info.data.padded_subbuf_size &&
-                                       stream->net_seq_idx ==
-                                                       (uint64_t) -1ULL)) {
-               /*
-                * Display the error but continue processing to try to
-                * release the subbuffer. This is a DBG statement
-                * since this can happen without being a critical
-                * error.
-                */
-               DBG("Failed to write to tracefile (written_bytes: %zd != padded subbuffer size: %lu, subbuffer size: %lu)",
-                               written_bytes, subbuffer.info.data.padded_subbuf_size,
-                               subbuffer.info.data.subbuf_size);
+       if (written_bytes <= 0) {
+               ERR("Error consuming subbuffer: (%zd)", written_bytes);
+               ret = (int) written_bytes;
+               goto error_put_subbuf;
        }
 
        ret = stream->read_subbuffer_ops.put_next_subbuffer(stream, &subbuffer);