X-Git-Url: http://git.liburcu.org/?p=lttng-modules.git;a=blobdiff_plain;f=lttng-abi.c;h=9400f5374aad7ce1510e7db59bcc423568b50448;hp=bc0a0f6e4dd7516c09b280f1b4379c7972624166;hb=refs%2Fheads%2Fstable-2.7;hpb=9adb2e2253bdb5edf43efdd75f09df883ab1a7dc

diff --git a/lttng-abi.c b/lttng-abi.c
index bc0a0f6e..9400f537 100644
--- a/lttng-abi.c
+++ b/lttng-abi.c
@@ -50,6 +50,7 @@
 #include "wrapper/ringbuffer/frontend.h"
 #include "wrapper/poll.h"
 #include "wrapper/file.h"
+#include "wrapper/kref.h"
 #include "lttng-abi.h"
 #include "lttng-abi-old.h"
 #include "lttng-events.h"
@@ -130,10 +131,6 @@ int lttng_abi_tracepoint_list(void)
 	if (ret < 0)
 		goto open_error;
 	fd_install(file_fd, tracepoint_list_file);
-	if (file_fd < 0) {
-		ret = file_fd;
-		goto fd_error;
-	}
 	return file_fd;
 
 open_error:
@@ -174,10 +171,6 @@ int lttng_abi_syscall_list(void)
 	if (ret < 0)
 		goto open_error;
 	fd_install(file_fd, syscall_list_file);
-	if (file_fd < 0) {
-		ret = file_fd;
-		goto fd_error;
-	}
 	return file_fd;
 
 open_error:
@@ -425,6 +418,10 @@ int lttng_abi_create_channel(struct file *session_file,
 		transport_name = "<unknown>";
 		break;
 	}
+	if (atomic_long_add_unless(&session_file->f_count,
+		1, INT_MAX) == INT_MAX) {
+		goto refcount_error;
+	}
 	/*
 	 * We tolerate no failure path after channel creation. It will stay
 	 * invariant for the rest of the session.
@@ -442,11 +439,12 @@ int lttng_abi_create_channel(struct file *session_file,
 	chan->file = chan_file;
 	chan_file->private_data = chan;
 	fd_install(chan_fd, chan_file);
-	atomic_long_inc(&session_file->f_count);
 
 	return chan_fd;
 
 chan_error:
+	atomic_long_dec(&session_file->f_count);
+refcount_error:
 	fput(chan_file);
 file_error:
 	put_unused_fd(chan_fd);
@@ -686,6 +684,18 @@ 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;
 	}
@@ -741,6 +751,33 @@ 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;
 	}
@@ -935,17 +972,20 @@ int lttng_abi_open_metadata_stream(struct file *channel_file)
 		goto notransport;
 	}
 
+	if (!lttng_kref_get(&session->metadata_cache->refcount))
+		goto kref_error;
 	ret = lttng_abi_create_stream_fd(channel_file, stream_priv,
 			&lttng_metadata_ring_buffer_file_operations);
 	if (ret < 0)
 		goto fd_error;
 
-	kref_get(&session->metadata_cache->refcount);
 	list_add(&metadata_stream->list,
 		&session->metadata_cache->metadata_stream);
 	return ret;
 
 fd_error:
+	kref_put(&session->metadata_cache->refcount, metadata_cache_destroy);
+kref_error:
 	module_put(metadata_stream->transport->owner);
 notransport:
 	kfree(metadata_stream);
@@ -989,6 +1029,12 @@ int lttng_abi_create_event(struct file *channel_file,
 		ret = PTR_ERR(event_file);
 		goto file_error;
 	}
+	/* The event holds a reference on the channel */
+	if (atomic_long_add_unless(&channel_file->f_count,
+		1, INT_MAX) == INT_MAX) {
+		ret = -EOVERFLOW;
+		goto refcount_error;
+	}
 	if (event_param->instrumentation == LTTNG_KERNEL_TRACEPOINT
 			|| event_param->instrumentation == LTTNG_KERNEL_SYSCALL) {
 		struct lttng_enabler *enabler;
@@ -1020,11 +1066,11 @@ int lttng_abi_create_event(struct file *channel_file,
 	}
 	event_file->private_data = priv;
 	fd_install(event_fd, event_file);
-	/* The event holds a reference on the channel */
-	atomic_long_inc(&channel_file->f_count);
 	return event_fd;
 
 event_error:
+	atomic_long_dec(&channel_file->f_count);
+refcount_error:
 	fput(event_file);
 file_error:
 	put_unused_fd(event_fd);