pjd@'s r180759 was intended to revert r180755 due to ipfilter breakage,

but removed too much, breaking the build in other places instead.  Now
that the ipfilter issue has been fixed (or hacked around), address the
second issue by restoring r180755, with one small change.  I don't feel
comfortable using assert(3) in a header that will be included in userland
code that may or may not already have an assertion mechanism in place,
so KASSERT() evaluates to a no-op in the !_KERNEL case.

1 files changed, 14 insertions, 1 deletions

diff --git a/sys/sys/refcount.h b/sys/sys/refcount.h
index 9788fdf..d15dbe0 100644
--- a/sys/sys/refcount.h
+++ b/sys/sys/refcount.h
@@ -32,6 +32,15 @@
 #ifndef __SYS_REFCOUNT_H__
 #define __SYS_REFCOUNT_H__
 
+#include <machine/atomic.h>
+
+#ifdef _KERNEL
+#warning _KERNEL defined
+#include <sys/systm.h>
+#else
+#define	KASSERT(exp, msg)	/* */
+#endif
+
 static __inline void
 refcount_init(volatile u_int *count, u_int value)
 {
@@ -49,8 +58,12 @@ refcount_acquire(volatile u_int *count)
 static __inline int
 refcount_release(volatile u_int *count)
 {
+	u_int old;
 
-	return (atomic_fetchadd_int(count, -1) == 1);
+	/* XXX: Should this have a rel membar? */
+	old = atomic_fetchadd_int(count, -1);
+	KASSERT(old > 0, ("negative refcount %p", count));
+	return (old == 1);
 }
 
 #endif	/* ! __SYS_REFCOUNT_H__ */