From: guenther <guenther@openbsd.org>
Date: Thu, 14 Dec 2017 17:25:39 +0000 (+0000)
Subject: If switching RW->RO, then stop deferring timestamp writes...and possibly
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=44961df1dceab8b67f900b362f44ce7d89e9fa6a;p=openbsd

If switching RW->RO, then stop deferring timestamp writes...and possibly
other pending inode attribute changes.  We appear to be missing UFS_UPDATE()
calls in some paths with the result that bsd.rd remounting the newly
created /mnt to RO would lose the GID changes on device inodes there.
This only affected devices, as they're the only inodes where timestamp
writes are delayed.

ok deraadt@
---

diff --git a/sys/ufs/ffs/ffs_vfsops.c b/sys/ufs/ffs/ffs_vfsops.c
index 15c0722cd62..a04cda2e70f 100644
--- a/sys/ufs/ffs/ffs_vfsops.c
+++ b/sys/ufs/ffs/ffs_vfsops.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ffs_vfsops.c,v 1.168 2017/12/11 17:13:34 deraadt Exp $	*/
+/*	$OpenBSD: ffs_vfsops.c,v 1.169 2017/12/14 17:25:39 guenther Exp $	*/
 /*	$NetBSD: ffs_vfsops.c,v 1.19 1996/02/09 22:22:26 christos Exp $	*/
 
 /*
@@ -1151,11 +1151,23 @@ ffs_sync_vnode(struct vnode *vp, void *arg) {
 	struct inode *ip;
 	int error;
 
+	if (vp->v_type == VNON)
+		return (0);
+
 	ip = VTOI(vp);
-	if (vp->v_type == VNON || 
-	    ((ip->i_flag &
+
+	/*
+	 * If unmounting or converting rw to ro, then stop deferring
+	 * timestamp writes.
+	 */
+	if (fsa->waitfor == MNT_WAIT && (ip->i_flag & IN_LAZYMOD)) {
+		ip->i_flag |= IN_MODIFIED;
+		UFS_UPDATE(ip, 1);
+	}
+
+	if ((ip->i_flag &
 		(IN_ACCESS | IN_CHANGE | IN_MODIFIED | IN_UPDATE)) == 0	&&
-		LIST_EMPTY(&vp->v_dirtyblkhd)) ) {
+		LIST_EMPTY(&vp->v_dirtyblkhd)) {
 		return (0);
 	}