Support snapshot max-size limitation

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

diff --git a/src/common/ust-consumer/ust-consumer.c b/src/common/ust-consumer/ust-consumer.c
index 1bb07c0c73606139e38a7c8e8c0e932ab7709459..b2434eb5a78948da66555e4ce48951c1b776fede 100644 (file)
--- a/src/common/ust-consumer/ust-consumer.c
+++ b/src/common/ust-consumer/ust-consumer.c
@@ -859,7 +859,7 @@ error:
  * Returns 0 on success, < 0 on error
  */
 static int snapshot_channel(uint64_t key, char *path, uint64_t relayd_id,
-               struct lttng_consumer_local_data *ctx)
+               uint64_t max_stream_size, struct lttng_consumer_local_data *ctx)
 {
        int ret;
        unsigned use_relayd = 0;
@@ -930,6 +930,15 @@ static int snapshot_channel(uint64_t key, char *path, uint64_t relayd_id,
                        goto error_unlock;
                }
 
+               /*
+                * The original value is sent back if max stream size is larger than
+                * the possible size of the snapshot. Also, we asume that the session
+                * daemon should never send a maximum stream size that is lower than
+                * subbuffer size.
+                */
+               consumed_pos = consumer_get_consumed_maxsize(consumed_pos,
+                               produced_pos, max_stream_size);
+
                while (consumed_pos < produced_pos) {
                        ssize_t read_len;
                        unsigned long len, padded_len;
@@ -1425,6 +1434,7 @@ int lttng_ustconsumer_recv_cmd(struct lttng_consumer_local_data *ctx,
                        ret = snapshot_channel(msg.u.snapshot_channel.key,
                                        msg.u.snapshot_channel.pathname,
                                        msg.u.snapshot_channel.relayd_id,
+                                       msg.u.snapshot_channel.max_stream_size,
                                        ctx);
                        if (ret < 0) {
                                ERR("Snapshot channel failed");