X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=ltt-events.c;h=3532dee5a1c8d46e246fa14c8e6c07a1257f26c7;hb=9fe47d1849406a219578176753b763998dc7fad1;hp=ffcc61ec65d5657fb03a0e0ca7958cb1df43f60f;hpb=17baffe29814f2508556e498ab8c41a192e76b67;p=lttng-modules.git

diff --git a/ltt-events.c b/ltt-events.c
index ffcc61ec..3532dee5 100644
--- a/ltt-events.c
+++ b/ltt-events.c
@@ -14,7 +14,7 @@
 #include <linux/sched.h>
 #include <linux/slab.h>
 #include <linux/jiffies.h>
-#include <linux/uuid.h>
+#include "wrapper/uuid.h"
 #include "wrapper/vmalloc.h"	/* for wrapper_vmalloc_sync_all() */
 #include "ltt-events.h"
 #include "ltt-tracer.h"
@@ -34,8 +34,6 @@ int _ltt_event_metadata_statedump(struct ltt_session *session,
 static
 int _ltt_session_metadata_statedump(struct ltt_session *session);
 
-
-static
 void synchronize_trace(void)
 {
 	synchronize_sched();
@@ -82,7 +80,7 @@ void ltt_session_destroy(struct ltt_session *session)
 	kfree(session);
 }
 
-int ltt_session_start(struct ltt_session *session)
+int ltt_session_enable(struct ltt_session *session)
 {
 	int ret = 0;
 	struct ltt_channel *chan;
@@ -108,18 +106,15 @@ int ltt_session_start(struct ltt_session *session)
 
 	ACCESS_ONCE(session->active) = 1;
 	ACCESS_ONCE(session->been_active) = 1;
-	synchronize_trace();	/* Wait for in-flight events to complete */
 	ret = _ltt_session_metadata_statedump(session);
-	if (ret) {
+	if (ret)
 		ACCESS_ONCE(session->active) = 0;
-		synchronize_trace();	/* Wait for in-flight events to complete */
-	}
 end:
 	mutex_unlock(&sessions_mutex);
 	return ret;
 }
 
-int ltt_session_stop(struct ltt_session *session)
+int ltt_session_disable(struct ltt_session *session)
 {
 	int ret = 0;
 
@@ -129,12 +124,59 @@ int ltt_session_stop(struct ltt_session *session)
 		goto end;
 	}
 	ACCESS_ONCE(session->active) = 0;
-	synchronize_trace();	/* Wait for in-flight events to complete */
 end:
 	mutex_unlock(&sessions_mutex);
 	return ret;
 }
 
+int ltt_channel_enable(struct ltt_channel *channel)
+{
+	int old;
+
+	if (channel == channel->session->metadata)
+		return -EPERM;
+	old = xchg(&channel->enabled, 1);
+	if (old)
+		return -EEXIST;
+	return 0;
+}
+
+int ltt_channel_disable(struct ltt_channel *channel)
+{
+	int old;
+
+	if (channel == channel->session->metadata)
+		return -EPERM;
+	old = xchg(&channel->enabled, 0);
+	if (!old)
+		return -EEXIST;
+	return 0;
+}
+
+int ltt_event_enable(struct ltt_event *event)
+{
+	int old;
+
+	if (event->chan == event->chan->session->metadata)
+		return -EPERM;
+	old = xchg(&event->enabled, 1);
+	if (old)
+		return -EEXIST;
+	return 0;
+}
+
+int ltt_event_disable(struct ltt_event *event)
+{
+	int old;
+
+	if (event->chan == event->chan->session->metadata)
+		return -EPERM;
+	old = xchg(&event->enabled, 0);
+	if (!old)
+		return -EEXIST;
+	return 0;
+}
+
 static struct ltt_transport *ltt_transport_find(const char *name)
 {
 	struct ltt_transport *transport;
@@ -154,7 +196,7 @@ struct ltt_channel *ltt_channel_create(struct ltt_session *session,
 				       unsigned int read_timer_interval)
 {
 	struct ltt_channel *chan;
-	struct ltt_transport *transport;
+	struct ltt_transport *transport = NULL;
 
 	mutex_lock(&sessions_mutex);
 	if (session->been_active)
@@ -165,11 +207,14 @@ struct ltt_channel *ltt_channel_create(struct ltt_session *session,
 		       transport_name);
 		goto notransport;
 	}
+	if (!try_module_get(transport->owner)) {
+		printk(KERN_WARNING "LTT : Can't lock transport module.\n");
+		goto notransport;
+	}
 	chan = kzalloc(sizeof(struct ltt_channel), GFP_KERNEL);
 	if (!chan)
 		goto nomem;
 	chan->session = session;
-	init_waitqueue_head(&chan->notify_wait);
 	chan->id = session->free_chan_id++;
 	/*
 	 * Note: the channel creation op already writes into the packet
@@ -181,7 +226,9 @@ struct ltt_channel *ltt_channel_create(struct ltt_session *session,
 			read_timer_interval);
 	if (!chan->chan)
 		goto create_error;
+	chan->enabled = 1;
 	chan->ops = &transport->ops;
+	chan->transport = transport;
 	list_add(&chan->list, &session->chan);
 	mutex_unlock(&sessions_mutex);
 	return chan;
@@ -189,6 +236,8 @@ struct ltt_channel *ltt_channel_create(struct ltt_session *session,
 create_error:
 	kfree(chan);
 nomem:
+	if (transport)
+		module_put(transport->owner);
 notransport:
 active:
 	mutex_unlock(&sessions_mutex);
@@ -202,6 +251,7 @@ static
 void _ltt_channel_destroy(struct ltt_channel *chan)
 {
 	chan->ops->channel_destroy(chan->chan);
+	module_put(chan->transport->owner);
 	list_del(&chan->list);
 	lttng_destroy_context(chan->ctx);
 	kfree(chan);
@@ -233,6 +283,7 @@ struct ltt_event *ltt_event_create(struct ltt_channel *chan,
 	event->chan = chan;
 	event->filter = filter;
 	event->id = chan->free_event_id++;
+	event->enabled = 1;
 	event->instrumentation = event_param->instrumentation;
 	/* Populate ltt_event structure before tracepoint registration. */
 	smp_wmb();
@@ -385,7 +436,7 @@ int lttng_metadata_printf(struct ltt_session *session,
 		 * we need to bail out after timeout or being
 		 * interrupted.
 		 */
-		waitret = wait_event_interruptible_timeout(*chan->ops->get_reader_wait_queue(chan),
+		waitret = wait_event_interruptible_timeout(*chan->ops->get_reader_wait_queue(chan->chan),
 			({
 				ret = chan->ops->event_reserve(&ctx, 0);
 				ret != -ENOBUFS || !ret;
@@ -399,7 +450,7 @@ int lttng_metadata_printf(struct ltt_session *session,
 				ret = waitret;
 			goto end;
 		}
-		chan->ops->event_write(&ctx, &str[pos], len);
+		chan->ops->event_write(&ctx, &str[pos], reserve_len);
 		chan->ops->event_commit(&ctx);
 	}
 end: