Teach rw_status() and rrw_status() to return LK_EXCLOTHER if it's write

locked by a different thread.  Teach lockstatus() to return LK_EXCLUSIVE
if an exclusive lock is held by some other thread.

ok beck@ tedu@

4 files changed, 21 insertions, 6 deletions

diff --git a/sys/kern/kern_lock.c b/sys/kern/kern_lock.c
index cef4c7c7664..946fd17e3b3 100644
--- a/sys/kern/kern_lock.c
+++ b/sys/kern/kern_lock.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kern_lock.c,v 1.43 2014/01/21 01:48:44 tedu Exp $	*/
+/*	$OpenBSD: kern_lock.c,v 1.44 2014/07/09 13:32:00 guenther Exp $	*/
 
 /* 
  * Copyright (c) 1995
@@ -64,6 +64,8 @@ lockstatus(struct lock *lkp)
 	switch (rrw_status(&lkp->lk_lck)) {
 	case RW_WRITE:
 		return (LK_EXCLUSIVE);
+	case RW_WRITE_OTHER:
+		return (LK_EXCLOTHER);
 	case RW_READ:
 		return (LK_SHARED);
 	case 0:
diff --git a/sys/kern/kern_rwlock.c b/sys/kern/kern_rwlock.c
index a472b616400..e1def9e874d 100644
--- a/sys/kern/kern_rwlock.c
+++ b/sys/kern/kern_rwlock.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kern_rwlock.c,v 1.21 2014/01/21 01:48:44 tedu Exp $	*/
+/*	$OpenBSD: kern_rwlock.c,v 1.22 2014/07/09 13:32:00 guenther Exp $	*/
 
 /*
  * Copyright (c) 2002, 2003 Artur Grabowski <art@openbsd.org>
@@ -256,8 +256,12 @@ rw_exit(struct rwlock *rwl)
 int
 rw_status(struct rwlock *rwl)
 {
-	if (rwl->rwl_owner & RWLOCK_WRLOCK)
-		return RW_WRITE;
+	if (rwl->rwl_owner & RWLOCK_WRLOCK) {
+		if (RW_PROC(curproc) == RW_PROC(rwl->rwl_owner))
+			return RW_WRITE;
+		else
+			return RW_WRITE_OTHER;
+	}
 	if (rwl->rwl_owner)
 		return RW_READ;
 	return (0);
diff --git a/sys/sys/lock.h b/sys/sys/lock.h
index 0bbbdbceffe..558fd9192e5 100644
--- a/sys/sys/lock.h
+++ b/sys/sys/lock.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: lock.h,v 1.22 2013/05/01 17:13:05 tedu Exp $	*/
+/*	$OpenBSD: lock.h,v 1.23 2014/07/09 13:32:00 guenther Exp $	*/
 
 /* 
  * Copyright (c) 1995
@@ -72,6 +72,9 @@ struct lock {
 #define LK_RECURSEFAIL	0x40	/* fail if recursive exclusive lock */
 #define LK_RETRY	0x80	/* vn_lock: retry until locked */
 
+/* for lockstatus() only */
+#define LK_EXCLOTHER	0x100	/* exclusive lock held by some other thread */
+
 void	lockinit(struct lock *, int, char *, int, int);
 int	lockmgr(struct lock *, u_int flags, void *);
 int	lockstatus(struct lock *);
diff --git a/sys/sys/rwlock.h b/sys/sys/rwlock.h
index 0fa11f6780f..9103a914410 100644
--- a/sys/sys/rwlock.h
+++ b/sys/sys/rwlock.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: rwlock.h,v 1.15 2014/03/29 18:09:31 guenther Exp $	*/
+/*	$OpenBSD: rwlock.h,v 1.16 2014/07/09 13:32:00 guenther Exp $	*/
 /*
  * Copyright (c) 2002 Artur Grabowski <art@openbsd.org>
  *
@@ -109,6 +109,12 @@ int rw_status(struct rwlock *);
 #define RW_NOSLEEP	0x0040UL	/* don't wait for the lock */
 #define RW_RECURSEFAIL	0x0080UL	/* Fail on recursion for RRW locks. */
 
+/*
+ * for rw_status() and rrw_status() only: exclusive lock held by
+ * some other thread
+ */
+#define RW_WRITE_OTHER	0x0100UL
+
 #ifndef rw_cas
 int rw_cas(volatile unsigned long *, unsigned long, unsigned long);
 #endif