Prevent updating async option on softdep mount

`mount -uo async,nosoftdep /mnt' would set "async" but keep "softdep"
untouched on a read/write mount.

OK deraadt krw beck bluhm

diff --git a/sys/ufs/ffs/ffs_vfsops.c b/sys/ufs/ffs/ffs_vfsops.c
index 0695d54..6c52bea 100644 (file)
--- a/sys/ufs/ffs/ffs_vfsops.c
+++ b/sys/ufs/ffs/ffs_vfsops.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: ffs_vfsops.c,v 1.177 2018/05/27 06:02:15 visa Exp $   */
+/*     $OpenBSD: ffs_vfsops.c,v 1.178 2018/07/11 17:44:57 kn Exp $     */
 /*     $NetBSD: ffs_vfsops.c,v 1.19 1996/02/09 22:22:26 christos Exp $ */
 
 /*
@@ -241,6 +241,16 @@ ffs_mount(struct mount *mp, const char *path, void *data,
                error = 0;
                ronly = fs->fs_ronly;
 
+               /*
+                * Soft updates won't be set if read/write,
+                * so "async" will be illegal.
+                */
+               if (ronly == 0 && (mp->mnt_flag & MNT_ASYNC) &&
+                   (fs->fs_flags & FS_DOSOFTDEP)) {
+                       error = EINVAL;
+                       goto error_1;
+               }
+
                if (ronly == 0 && (mp->mnt_flag & MNT_RDONLY)) {
                        /* Flush any dirty data */
                        VFS_SYNC(mp, MNT_WAIT, 0, p->p_ucred, p);