- Upgrade a shared lock request to exclusive in ffs_vget() if we have

to create the vnode.

Sponsored by:	Isilon Systems, Inc.

sys/ufs/ffs/ffs_vfsops.c

@@ -1176,6 +1176,15 @@ ffs_vget(mp, ino, flags, vpp)
 	if (error || *vpp != NULL)
 		return (error);
 
+	/*
+	 * We must promote to an exclusive lock for vnode creation.  This
+	 * can happen if lookup is passed LOCKSHARED.
+ 	 */
+	if ((flags & LK_TYPE_MASK) == LK_SHARED) {
+		flags &= ~LK_TYPE_MASK;
+		flags |= LK_EXCLUSIVE;
+	}
+
 	/*
 	 * We do not lock vnode creation as it is believed to be too
 	 * expensive for such rare case as simultaneous creation of vnode