From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Date: Wed, 26 Jun 2013 23:42:52 +0000 (-0400)
Subject: print warning and return -EBUSY on double get_subbuf()
X-Git-Tag: v2.3.0-rc1~20
X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=8202b8a0cca4c5b271c8ff729aa3b572eece6edf;p=lttng-modules.git

print warning and return -EBUSY on double get_subbuf()

Each get_subbuf() should be paired with a put_subbuf().

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
---

diff --git a/lib/ringbuffer/ring_buffer_frontend.c b/lib/ringbuffer/ring_buffer_frontend.c
index bff920d1..84341adc 100644
--- a/lib/ringbuffer/ring_buffer_frontend.c
+++ b/lib/ringbuffer/ring_buffer_frontend.c
@@ -927,6 +927,13 @@ int lib_ring_buffer_get_subbuf(struct lib_ring_buffer *buf,
 	int ret;
 	int finalized;
 
+	if (buf->get_subbuf) {
+		/*
+		 * Reader is trying to get a subbuffer twice.
+		 */
+		CHAN_WARN_ON(chan, 1);
+		return -EBUSY;
+	}
 retry:
 	finalized = ACCESS_ONCE(buf->finalized);
 	/*