Fix: Use stream deletion function when cleaning up

In theory, once the destroy stream ht function is called with the hash
table, it should be empty. However, for some fatal errors, it might not
so it's imperative that we gracefully delete the stream and free it
using an RCU call so both hash tables (stream and the one for the
pending command) are synchronized.

Simply freeing the stream could have created possible fd leaks and
invalid node for the data pending hash table.

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

diff --git a/src/common/consumer.c b/src/common/consumer.c
index 5766860a89823bf40c4ebd98448fc233e54c06f2..ec73a0adda756dfbd28bfc556a9e0456ec6ba156 100644 (file)
--- a/src/common/consumer.c
+++ b/src/common/consumer.c
@@ -764,6 +764,8 @@ void consumer_del_channel(struct lttng_consumer_channel *channel)
        int ret;
        struct lttng_ht_iter iter;
 
+       DBG("Consumer delete channel key %d", channel->key);
+
        pthread_mutex_lock(&consumer_data.lock);
 
        switch (consumer_data.type) {
@@ -1695,7 +1697,6 @@ int lttng_consumer_recv_cmd(struct lttng_consumer_local_data *ctx,
  */
 static void destroy_data_stream_ht(struct lttng_ht *ht)
 {
-       int ret;
        struct lttng_ht_iter iter;
        struct lttng_consumer_stream *stream;
 
@@ -1705,10 +1706,11 @@ static void destroy_data_stream_ht(struct lttng_ht *ht)
 
        rcu_read_lock();
        cds_lfht_for_each_entry(ht->ht, &iter.iter, stream, node.node) {
-               ret = lttng_ht_del(ht, &iter);
-               assert(!ret);
-
-               call_rcu(&stream->node.head, consumer_free_stream);
+               /*
+                * Ignore return value since we are currently cleaning up so any error
+                * can't be handled.
+                */
+               (void) consumer_del_stream(stream, ht);
        }
        rcu_read_unlock();
 
@@ -1722,7 +1724,6 @@ static void destroy_data_stream_ht(struct lttng_ht *ht)
  */
 static void destroy_stream_ht(struct lttng_ht *ht)
 {
-       int ret;
        struct lttng_ht_iter iter;
        struct lttng_consumer_stream *stream;
 
@@ -1732,10 +1733,11 @@ static void destroy_stream_ht(struct lttng_ht *ht)
 
        rcu_read_lock();
        cds_lfht_for_each_entry(ht->ht, &iter.iter, stream, node.node) {
-               ret = lttng_ht_del(ht, &iter);
-               assert(!ret);
-
-               call_rcu(&stream->node.head, consumer_free_stream);
+               /*
+                * Ignore return value since we are currently cleaning up so any error
+                * can't be handled.
+                */
+               (void) consumer_del_metadata_stream(stream, ht);
        }
        rcu_read_unlock();