X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fcommon%2Fkernel-consumer%2Fkernel-consumer.cpp;fp=src%2Fcommon%2Fkernel-consumer%2Fkernel-consumer.cpp;h=8a6ef2a2760e14b7047785add29632589855cfb3;hp=aa443027effe021529816ad6a1ea7ffbd8dc3163;hb=947bd0978b3d17b34eb1158cc6439eb1d4e5b6c3;hpb=ef9ff9cb5ff4dd763d4c9dbbcfcb5952adce167e

diff --git a/src/common/kernel-consumer/kernel-consumer.cpp b/src/common/kernel-consumer/kernel-consumer.cpp
index aa443027e..8a6ef2a27 100644
--- a/src/common/kernel-consumer/kernel-consumer.cpp
+++ b/src/common/kernel-consumer/kernel-consumer.cpp
@@ -138,7 +138,7 @@ error:
 /*
  * Take a snapshot of all the stream of a channel
  * RCU read-side lock must be held across this function to ensure existence of
- * channel. The channel lock must be held by the caller.
+ * channel.
  *
  * Returns 0 on success, < 0 on error
  */
@@ -153,6 +153,9 @@ static int lttng_kconsumer_snapshot_channel(
 
 	DBG("Kernel consumer snapshot channel %" PRIu64, key);
 
+	/* Prevent channel modifications while we perform the snapshot.*/
+	pthread_mutex_lock(&channel->lock);
+
 	rcu_read_lock();
 
 	/* Splice is not supported yet for channel snapshot. */
@@ -346,13 +349,14 @@ end_unlock:
 	pthread_mutex_unlock(&stream->lock);
 end:
 	rcu_read_unlock();
+	pthread_mutex_unlock(&channel->lock);
 	return ret;
 }
 
 /*
  * Read the whole metadata available for a snapshot.
  * RCU read-side lock must be held across this function to ensure existence of
- * metadata_channel. The channel lock must be held by the caller.
+ * metadata_channel.
  *
  * Returns 0 on success, < 0 on error
  */
@@ -375,7 +379,7 @@ static int lttng_kconsumer_snapshot_metadata(
 	metadata_stream = metadata_channel->metadata_stream;
 	LTTNG_ASSERT(metadata_stream);
 
-	pthread_mutex_lock(&metadata_stream->lock);
+	metadata_stream->read_subbuffer_ops.lock(metadata_stream);
 	LTTNG_ASSERT(metadata_channel->trace_chunk);
 	LTTNG_ASSERT(metadata_stream->trace_chunk);
 
@@ -430,7 +434,7 @@ static int lttng_kconsumer_snapshot_metadata(
 
 	ret = 0;
 error_snapshot:
-	pthread_mutex_unlock(&metadata_stream->lock);
+	metadata_stream->read_subbuffer_ops.unlock(metadata_stream);
 	cds_list_del(&metadata_stream->send_node);
 	consumer_stream_destroy(metadata_stream, NULL);
 	metadata_channel->metadata_stream = NULL;
@@ -960,7 +964,6 @@ error_streams_sent_nosignal:
 			ERR("Channel %" PRIu64 " not found", key);
 			ret_code = LTTCOMM_CONSUMERD_CHAN_NOT_FOUND;
 		} else {
-			pthread_mutex_lock(&channel->lock);
 			if (msg.u.snapshot_channel.metadata == 1) {
 				int ret_snapshot;
 
@@ -988,7 +991,6 @@ error_streams_sent_nosignal:
 					ret_code = LTTCOMM_CONSUMERD_SNAPSHOT_FAILED;
 				}
 			}
-			pthread_mutex_unlock(&channel->lock);
 		}
 		health_code_update();