Fix: fd leak when closing metadata stream
[lttng-tools.git] / src / common / consumer.c
index b942778b32e9a768f7da0029507b52af10478804..9d5a36970551fd19a5cb2288ca15026f1bf8dc70 100644 (file)
@@ -225,16 +225,6 @@ struct lttng_consumer_channel *consumer_find_channel(uint64_t key)
        return channel;
 }
 
-static void free_stream_rcu(struct rcu_head *head)
-{
-       struct lttng_ht_node_u64 *node =
-               caa_container_of(head, struct lttng_ht_node_u64, head);
-       struct lttng_consumer_stream *stream =
-               caa_container_of(node, struct lttng_consumer_stream, node);
-
-       free(stream);
-}
-
 static void free_channel_rcu(struct rcu_head *head)
 {
        struct lttng_ht_node_u64 *node =
@@ -1956,7 +1946,7 @@ int lttng_consumer_recv_cmd(struct lttng_consumer_local_data *ctx,
        }
 }
 
-void lttng_consumer_close_metadata(void)
+void lttng_consumer_close_all_metadata(void)
 {
        switch (consumer_data.type) {
        case LTTNG_CONSUMER_KERNEL:
@@ -1974,7 +1964,7 @@ void lttng_consumer_close_metadata(void)
                 * because at this point we are sure that the metadata producer is
                 * either dead or blocked.
                 */
-               lttng_ustconsumer_close_metadata(metadata_ht);
+               lttng_ustconsumer_close_all_metadata(metadata_ht);
                break;
        default:
                ERR("Unknown consumer_data type");
@@ -1988,10 +1978,7 @@ void lttng_consumer_close_metadata(void)
 void consumer_del_metadata_stream(struct lttng_consumer_stream *stream,
                struct lttng_ht *ht)
 {
-       int ret;
-       struct lttng_ht_iter iter;
        struct lttng_consumer_channel *free_chan = NULL;
-       struct consumer_relayd_sock_pair *relayd;
 
        assert(stream);
        /*
@@ -2002,96 +1989,17 @@ void consumer_del_metadata_stream(struct lttng_consumer_stream *stream,
 
        DBG3("Consumer delete metadata stream %d", stream->wait_fd);
 
-       if (ht == NULL) {
-               /* Means the stream was allocated but not successfully added */
-               goto free_stream_rcu;
-       }
-
        pthread_mutex_lock(&consumer_data.lock);
        pthread_mutex_lock(&stream->chan->lock);
        pthread_mutex_lock(&stream->lock);
 
-       switch (consumer_data.type) {
-       case LTTNG_CONSUMER_KERNEL:
-               if (stream->mmap_base != NULL) {
-                       ret = munmap(stream->mmap_base, stream->mmap_len);
-                       if (ret != 0) {
-                               PERROR("munmap metadata stream");
-                       }
-               }
-               if (stream->wait_fd >= 0) {
-                       ret = close(stream->wait_fd);
-                       if (ret < 0) {
-                               PERROR("close kernel metadata wait_fd");
-                       }
-               }
-               break;
-       case LTTNG_CONSUMER32_UST:
-       case LTTNG_CONSUMER64_UST:
-               if (stream->monitor) {
-                       /* close the write-side in close_metadata */
-                       ret = close(stream->ust_metadata_poll_pipe[0]);
-                       if (ret < 0) {
-                               PERROR("Close UST metadata read-side poll pipe");
-                       }
-               }
-               lttng_ustconsumer_del_stream(stream);
-               break;
-       default:
-               ERR("Unknown consumer_data type");
-               assert(0);
-               goto end;
-       }
-
-       rcu_read_lock();
-       iter.iter.node = &stream->node.node;
-       ret = lttng_ht_del(ht, &iter);
-       assert(!ret);
+       /* Remove any reference to that stream. */
+       consumer_stream_delete(stream, ht);
 
-       iter.iter.node = &stream->node_channel_id.node;
-       ret = lttng_ht_del(consumer_data.stream_per_chan_id_ht, &iter);
-       assert(!ret);
-
-       iter.iter.node = &stream->node_session_id.node;
-       ret = lttng_ht_del(consumer_data.stream_list_ht, &iter);
-       assert(!ret);
-       rcu_read_unlock();
-
-       if (stream->out_fd >= 0) {
-               ret = close(stream->out_fd);
-               if (ret) {
-                       PERROR("close");
-               }
-       }
-
-       /* Check and cleanup relayd */
-       rcu_read_lock();
-       relayd = consumer_find_relayd(stream->net_seq_idx);
-       if (relayd != NULL) {
-               uatomic_dec(&relayd->refcount);
-               assert(uatomic_read(&relayd->refcount) >= 0);
-
-               /* Closing streams requires to lock the control socket. */
-               pthread_mutex_lock(&relayd->ctrl_sock_mutex);
-               ret = relayd_send_close_stream(&relayd->control_sock,
-                               stream->relayd_stream_id, stream->next_net_seq_num - 1);
-               pthread_mutex_unlock(&relayd->ctrl_sock_mutex);
-               if (ret < 0) {
-                       DBG("Unable to close stream on the relayd. Continuing");
-                       /*
-                        * Continue here. There is nothing we can do for the relayd.
-                        * Chances are that the relayd has closed the socket so we just
-                        * continue cleaning up.
-                        */
-               }
-
-               /* Both conditions are met, we destroy the relayd. */
-               if (uatomic_read(&relayd->refcount) == 0 &&
-                               uatomic_read(&relayd->destroy_flag)) {
-                       consumer_destroy_relayd(relayd);
-               }
-       }
-       rcu_read_unlock();
+       /* Close down everything including the relayd if one. */
+       consumer_stream_close(stream);
+       /* Destroy tracer buffers of the stream. */
+       consumer_stream_destroy_buffers(stream);
 
        /* Atomically decrement channel refcount since other threads can use it. */
        if (!uatomic_sub_return(&stream->chan->refcount, 1)
@@ -2100,11 +2008,10 @@ void consumer_del_metadata_stream(struct lttng_consumer_stream *stream,
                free_chan = stream->chan;
        }
 
-end:
        /*
         * Nullify the stream reference so it is not used after deletion. The
-        * channel lock MUST be acquired before being able to check for
-        * a NULL pointer value.
+        * channel lock MUST be acquired before being able to check for a NULL
+        * pointer value.
         */
        stream->chan->metadata_stream = NULL;
 
@@ -2116,8 +2023,7 @@ end:
                consumer_del_channel(free_chan);
        }
 
-free_stream_rcu:
-       call_rcu(&stream->node.head, free_stream_rcu);
+       consumer_stream_free(stream);
 }
 
 /*
@@ -2354,7 +2260,7 @@ restart:
 
                                        /* Add metadata stream to the global poll events list */
                                        lttng_poll_add(&events, stream->wait_fd,
-                                                       LPOLLIN | LPOLLPRI);
+                                                       LPOLLIN | LPOLLPRI | LPOLLHUP);
                                }
 
                                /* Handle other stream */
@@ -3174,7 +3080,7 @@ end:
         *
         * NOTE: for now, this only applies to the UST tracer.
         */
-       lttng_consumer_close_metadata();
+       lttng_consumer_close_all_metadata();
 
        /*
         * when all fds have hung up, the polling thread
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