factor out sync+wait code into vfa_syncwait() routine for

applications in system like power management and such.
art@ finally said `commit it'

2 files changed, 31 insertions, 17 deletions

diff --git a/sys/kern/vfs_subr.c b/sys/kern/vfs_subr.c
index 05317f457ad..4df9a385a12 100644
--- a/sys/kern/vfs_subr.c
+++ b/sys/kern/vfs_subr.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: vfs_subr.c,v 1.37 1999/04/30 08:21:52 art Exp $	*/
+/*	$OpenBSD: vfs_subr.c,v 1.38 1999/05/06 15:59:40 mickey Exp $	*/
 /*	$NetBSD: vfs_subr.c,v 1.53 1996/04/22 01:39:13 christos Exp $	*/
 
 /*
@@ -1727,9 +1727,6 @@ vfs_unmountall()
 void
 vfs_shutdown()
 {
-	register struct buf *bp;
-	int iter, nbusy;
-
 	/* XXX Should suspend scheduling. */
 	(void) spl0();
 
@@ -1751,24 +1748,40 @@ vfs_shutdown()
 		vfs_unmountall();
 	}
 
-	/* Sync again after unmount, just in case. */
-	sys_sync(&proc0, (void *)0, (register_t *)0);
+	if (vfs_syncwait(1))
+		printf("giving up\n");
+	else
+		printf("done\n");
+}
+
+/*
+ * perform sync() operation and wait for buffers to flush.
+ * assumtions: called w/ scheduler disabled and physical io enabled
+ * for now called at spl0() XXX
+ */
+int
+vfs_syncwait(verbose)
+	int verbose;
+{
+	register struct buf *bp;
+	int iter, nbusy;
 
+	sys_sync(&proc0, (void *)0, (register_t *)0);
+ 
 	/* Wait for sync to finish. */
 	for (iter = 0; iter < 20; iter++) {
 		nbusy = 0;
 		for (bp = &buf[nbuf]; --bp >= buf; )
 			if ((bp->b_flags & (B_BUSY|B_INVAL)) == B_BUSY)
 				nbusy++;
-		if (nbusy == 0)
-			break;
-		printf("%d ", nbusy);
-		DELAY(40000 * iter);
-	}
-	if (nbusy)
-		printf("giving up\n");
-	else
-		printf("done\n");
+			if (nbusy == 0)
+				break;
+			if (verbose)
+				printf("%d ", nbusy);
+			DELAY(40000 * iter);
+	}   
+
+	return nbusy;
 }
 
 /*
diff --git a/sys/sys/mount.h b/sys/sys/mount.h
index 9bf243df745..f183c31f41f 100644
--- a/sys/sys/mount.h
+++ b/sys/sys/mount.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: mount.h,v 1.27 1999/03/11 18:55:24 deraadt Exp $	*/
+/*	$OpenBSD: mount.h,v 1.28 1999/05/06 15:59:48 mickey Exp $	*/
 /*	$NetBSD: mount.h,v 1.48 1996/02/18 11:55:47 fvdl Exp $	*/
 
 /*
@@ -506,7 +506,8 @@ struct	netcred *vfs_export_lookup	    /* lookup host in fs export list */
 	  __P((struct mount *, struct netexport *, struct mbuf *));
 int	vfs_allocate_syncvnode __P((struct mount *));
 
-void	vfs_shutdown __P((void));	    /* unmount and sync file systems */
+int	vfs_syncwait __P((int));	/* sync and wait for complete */
+void	vfs_shutdown __P((void));	/* unmount and sync file systems */
 long	makefstype __P((char *));
 int	dounmount __P((struct mount *, int, struct proc *));
 void	vfsinit __P((void));