Fix: ring buffer: honor switch parameter type in remote switch

[lttng-modules.git] / lttng-abi.c

diff --git a/lttng-abi.c b/lttng-abi.c
index 5823a1db042d6fa8aa5e88bef4a35235bf5eea4e..0f01d3d7df558b3ad6515edddc5006d865693d8b 100644 (file)
--- a/lttng-abi.c
+++ b/lttng-abi.c
@@ -565,9 +565,11 @@ unsigned int lttng_metadata_ring_buffer_poll(struct file *filp,
                if (finalized)
                        mask |= POLLHUP;
 
+               mutex_lock(&stream->metadata_cache->lock);
                if (stream->metadata_cache->metadata_written >
                                stream->metadata_out)
                        mask |= POLLIN;
+               mutex_unlock(&stream->metadata_cache->lock);
        }
 
        return mask;
@@ -627,6 +629,18 @@ long lttng_metadata_ring_buffer_ioctl(struct file *filp,
                        goto err;
                break;
        }
+       case RING_BUFFER_SNAPSHOT:
+       {
+               /*
+                * Force the buffer to quiescent so the ring buffer
+                * don't attempt to perform a SWITCH_FLUSH, which would
+                * desynchronize the client accounting of the amount of
+                * data available in the buffer from the ring buffer
+                * view.
+                */
+               buf->quiescent = true;
+               break;
+       }
        default:
                break;
        }
@@ -682,6 +696,33 @@ long lttng_metadata_ring_buffer_compat_ioctl(struct file *filp,
                 */
                return -ENOSYS;
        }
+       case RING_BUFFER_FLUSH:
+       {
+               struct lttng_metadata_stream *stream = filp->private_data;
+               struct lib_ring_buffer *buf = stream->priv;
+               struct channel *chan = buf->backend.chan;
+
+               /*
+                * Before doing the actual ring buffer flush, write up to one
+                * packet of metadata in the ring buffer.
+                */
+               ret = lttng_metadata_output_channel(stream, chan);
+               if (ret < 0)
+                       goto err;
+               break;
+       }
+       case RING_BUFFER_SNAPSHOT:
+       {
+               /*
+                * Force the buffer to quiescent so the ring buffer
+                * don't attempt to perform a SWITCH_FLUSH, which would
+                * desynchronize the client accounting of the amount of
+                * data available in the buffer from the ring buffer
+                * view.
+                */
+               buf->quiescent = true;
+               break;
+       }
        default:
                break;
        }
@@ -865,7 +906,6 @@ int lttng_abi_open_metadata_stream(struct file *channel_file)
        metadata_stream->priv = buf;
        stream_priv = metadata_stream;
        metadata_stream->transport = channel->transport;
-       mutex_init(&metadata_stream->lock);
 
        /*
         * Since life-time of metadata cache differs from that of
@@ -1233,8 +1273,8 @@ int lttng_metadata_channel_release(struct inode *inode, struct file *file)
        struct lttng_channel *channel = file->private_data;
 
        if (channel) {
-               lttng_metadata_channel_destroy(channel);
                fput(channel->session->file);
+               lttng_metadata_channel_destroy(channel);
        }
 
        return 0;