From 7e932641df8e028debaac64baac3d61c20b05f78 Mon Sep 17 00:00:00 2001
From: Thomas Schoebel-Theuer <tst@1und1.de>
Date: Thu, 17 Apr 2014 09:01:46 +0200
Subject: [PATCH] bio: fix refcounting

---
 kernel/mars_bio.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/kernel/mars_bio.c b/kernel/mars_bio.c
index 9468b7c3..f1f63f0d 100644
--- a/kernel/mars_bio.c
+++ b/kernel/mars_bio.c
@@ -425,15 +425,17 @@ done: ;
 static
 void bio_ref_io(struct bio_output *output, struct mref_object *mref)
 {
+	CHECK_PTR(mref, fatal);
+
+	_mref_get(mref);
 	atomic_inc(&mars_global_io_flying);
+
 	if (mref->ref_prio == MARS_PRIO_LOW ||
 	    (mref->ref_prio == MARS_PRIO_NORMAL && mref->ref_rw)) {
 		struct bio_mref_aspect *mref_a = bio_mref_get_aspect(output->brick, mref);
 		struct bio_brick *brick = output->brick;
 		unsigned long flags;
 
-		_mref_get(mref);
-
 		spin_lock_irqsave(&brick->lock, flags);
 		list_add_tail(&mref_a->io_head, &brick->queue_list[PRIO_INDEX(mref)]);
 		atomic_inc(&brick->queue_count[PRIO_INDEX(mref)]);
@@ -443,8 +445,14 @@ void bio_ref_io(struct bio_output *output, struct mref_object *mref)
 		wake_up_interruptible(&brick->submit_event);
 		return;
 	}
+
 	// realtime IO: start immediately
 	_bio_ref_io(output, mref, false);
+	BIO_REF_PUT(output, mref);
+	return;
+
+fatal:
+	MARS_FAT("cannot handle mref %p on output %p\n", mref, output);
 }
 
 static