1 files changed, 85 insertions, 0 deletions
diff --git a/module/zfs/vdev_missing.c b/module/zfs/vdev_missing.c
new file mode 100644
index 000000000..731f7d3dc
--- /dev/null
+++ b/module/zfs/vdev_missing.c
@@ -0,0 +1,85 @@
+/*
+ * CDDL HEADER START
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License (the "License").
+ * You may not use this file except in compliance with the License.
+ *
+ * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+ * or http://www.opensolaris.org/os/licensing.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ *
+ * When distributing Covered Code, include this CDDL HEADER in each
+ * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+ * If applicable, add the following below this CDDL HEADER, with the
+ * fields enclosed by brackets "[]" replaced with your own identifying
+ * information: Portions Copyright [yyyy] [name of copyright owner]
+ *
+ * CDDL HEADER END
+ */
+/*
+ * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
+ * Use is subject to license terms.
+ */
+
+/*
+ * The 'missing' vdev is a special vdev type used only during import.  It
+ * signifies a placeholder in the root vdev for some vdev that we know is
+ * missing.  We pass it down to the kernel to allow the rest of the
+ * configuration to parsed and an attempt made to open all available devices.
+ * Because its GUID is always 0, we know that the guid sum will mismatch and we
+ * won't be able to open the pool anyway.
+ */
+
+#include <sys/zfs_context.h>
+#include <sys/spa.h>
+#include <sys/vdev_impl.h>
+#include <sys/fs/zfs.h>
+#include <sys/zio.h>
+
+/* ARGSUSED */
+static int
+vdev_missing_open(vdev_t *vd, uint64_t *psize, uint64_t *ashift)
+{
+	/*
+	 * Really this should just fail.  But then the root vdev will be in the
+	 * faulted state with VDEV_AUX_NO_REPLICAS, when what we really want is
+	 * VDEV_AUX_BAD_GUID_SUM.  So we pretend to succeed, knowing that we
+	 * will fail the GUID sum check before ever trying to open the pool.
+	 */
+	*psize = SPA_MINDEVSIZE;
+	*ashift = SPA_MINBLOCKSHIFT;
+	return (0);
+}
+
+/* ARGSUSED */
+static void
+vdev_missing_close(vdev_t *vd)
+{
+}
+
+/* ARGSUSED */
+static int
+vdev_missing_io_start(zio_t *zio)
+{
+	zio->io_error = ENOTSUP;
+	return (ZIO_PIPELINE_CONTINUE);
+}
+
+/* ARGSUSED */
+static void
+vdev_missing_io_done(zio_t *zio)
+{
+}
+
+vdev_ops_t vdev_missing_ops = {
+	vdev_missing_open,
+	vdev_missing_close,
+	vdev_default_asize,
+	vdev_missing_io_start,
+	vdev_missing_io_done,
+	NULL,
+	VDEV_TYPE_MISSING,	/* name of this vdev type */
+	B_TRUE			/* leaf vdev */
+};