X-Git-Url: http://git.lttng.org/?a=blobdiff_plain;f=lttng-abi.c;h=ea746c2cfbfb33b1ee7b191be351de9d81bd86a6;hb=d7921a5faa41a160c2679bb130e31c79ee8641f2;hp=f2b207cbac95aa9ced52b603242784ca90caaaf3;hpb=4993071a89f88f92444cf62abdc0935efbc6c460;p=lttng-modules.git

diff --git a/lttng-abi.c b/lttng-abi.c
index f2b207cb..ea746c2c 100644
--- a/lttng-abi.c
+++ b/lttng-abi.c
@@ -56,6 +56,7 @@
 #include <lttng-abi-old.h>
 #include <lttng-events.h>
 #include <lttng-tracer.h>
+#include <lttng-tp-mempool.h>
 #include <lib/ringbuffer/frontend_types.h>
 
 /*
@@ -654,6 +655,38 @@ void lttng_metadata_ring_buffer_ioctl_put_next_subbuf(struct file *filp,
 	stream->metadata_out = stream->metadata_in;
 }
 
+/*
+ * Reset the counter of how much metadata has been consumed to 0. That way,
+ * the consumer receives the content of the metadata cache unchanged. This is
+ * different from the metadata_regenerate where the offset from epoch is
+ * resampled, here we want the exact same content as the last time the metadata
+ * was generated. This command is only possible if all the metadata written
+ * in the cache has been output to the metadata stream to avoid corrupting the
+ * metadata file.
+ *
+ * Return 0 on success, a negative value on error.
+ */
+static
+int lttng_metadata_cache_dump(struct lttng_metadata_stream *stream)
+{
+	int ret;
+	struct lttng_metadata_cache *cache = stream->metadata_cache;
+
+	mutex_lock(&cache->lock);
+	if (stream->metadata_out != cache->metadata_written) {
+		ret = -EBUSY;
+		goto end;
+	}
+	stream->metadata_out = 0;
+	stream->metadata_in = 0;
+	wake_up_interruptible(&stream->read_wait);
+	ret = 0;
+
+end:
+	mutex_unlock(&cache->lock);
+	return ret;
+}
+
 static
 long lttng_metadata_ring_buffer_ioctl(struct file *filp,
 		unsigned int cmd, unsigned long arg)
@@ -684,6 +717,7 @@ long lttng_metadata_ring_buffer_ioctl(struct file *filp,
 		 */
 		return -ENOSYS;
 	}
+	case RING_BUFFER_FLUSH_EMPTY:	/* Fall-through. */
 	case RING_BUFFER_FLUSH:
 	{
 		struct lttng_metadata_stream *stream = filp->private_data;
@@ -705,17 +739,11 @@ long lttng_metadata_ring_buffer_ioctl(struct file *filp,
 
 		return put_u64(stream->version, arg);
 	}
-	case RING_BUFFER_SNAPSHOT:
+	case RING_BUFFER_METADATA_CACHE_DUMP:
 	{
-		/*
-		 * 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;
+		struct lttng_metadata_stream *stream = filp->private_data;
+
+		return lttng_metadata_cache_dump(stream);
 	}
 	default:
 		break;
@@ -772,6 +800,7 @@ long lttng_metadata_ring_buffer_compat_ioctl(struct file *filp,
 		 */
 		return -ENOSYS;
 	}
+	case RING_BUFFER_FLUSH_EMPTY:	/* Fall-through. */
 	case RING_BUFFER_FLUSH:
 	{
 		struct lttng_metadata_stream *stream = filp->private_data;
@@ -793,17 +822,11 @@ long lttng_metadata_ring_buffer_compat_ioctl(struct file *filp,
 
 		return put_u64(stream->version, arg);
 	}
-	case RING_BUFFER_SNAPSHOT:
+	case RING_BUFFER_METADATA_CACHE_DUMP:
 	{
-		/*
-		 * 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;
+		struct lttng_metadata_stream *stream = filp->private_data;
+
+		return lttng_metadata_cache_dump(stream);
 	}
 	default:
 		break;
@@ -1749,6 +1772,12 @@ int __init lttng_abi_init(void)
 
 	wrapper_vmalloc_sync_all();
 	lttng_clock_ref();
+
+	ret = lttng_tp_mempool_init();
+	if (ret) {
+		goto error;
+	}
+
 	lttng_proc_dentry = proc_create_data("lttng", S_IRUSR | S_IWUSR, NULL,
 					&lttng_fops, NULL);
 
@@ -1761,6 +1790,7 @@ int __init lttng_abi_init(void)
 	return 0;
 
 error:
+	lttng_tp_mempool_destroy();
 	lttng_clock_unref();
 	return ret;
 }
@@ -1768,6 +1798,7 @@ error:
 /* No __exit annotation because used by init error path too. */
 void lttng_abi_exit(void)
 {
+	lttng_tp_mempool_destroy();
 	lttng_clock_unref();
 	if (lttng_proc_dentry)
 		remove_proc_entry("lttng", NULL);