Please welcome ZFS - The last word in file systems.

ZFS file system was ported from OpenSolaris operating system. The code in under
CDDL license.

I'd like to thank all SUN developers that created this great piece of software.

Supported by:	Wheel LTD (http://www.wheel.pl/)
Supported by:	The FreeBSD Foundation (http://www.freebsdfoundation.org/)
Supported by:	Sentex (http://www.sentex.net/)

1 files changed, 118 insertions, 0 deletions

diff --git a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/vdev_root.c b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/vdev_root.c
new file mode 100644
index 0000000..0e8752c
--- /dev/null
+++ b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/vdev_root.c
@@ -0,0 +1,118 @@
+/*
+ * 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 2006 Sun Microsystems, Inc.  All rights reserved.
+ * Use is subject to license terms.
+ */
+
+#pragma ident	"%Z%%M%	%I%	%E% SMI"
+
+#include <sys/zfs_context.h>
+#include <sys/spa.h>
+#include <sys/vdev_impl.h>
+#include <sys/zio.h>
+#include <sys/fs/zfs.h>
+
+/*
+ * Virtual device vector for the pool's root vdev.
+ */
+
+/*
+ * We should be able to tolerate one failure with absolutely no damage
+ * to our metadata.  Two failures will take out space maps, a bunch of
+ * indirect block trees, meta dnodes, dnodes, etc.  Probably not a happy
+ * place to live.  When we get smarter, we can liberalize this policy.
+ * e.g. If we haven't lost two consecutive top-level vdevs, then we are
+ * probably fine.  Adding bean counters during alloc/free can make this
+ * future guesswork more accurate.
+ */
+/*ARGSUSED*/
+static int
+too_many_errors(vdev_t *vd, int numerrors)
+{
+	return (numerrors > 0);
+}
+
+static int
+vdev_root_open(vdev_t *vd, uint64_t *asize, uint64_t *ashift)
+{
+	vdev_t *cvd;
+	int c, error;
+	int lasterror = 0;
+	int numerrors = 0;
+
+	if (vd->vdev_children == 0) {
+		vd->vdev_stat.vs_aux = VDEV_AUX_BAD_LABEL;
+		return (EINVAL);
+	}
+
+	for (c = 0; c < vd->vdev_children; c++) {
+		cvd = vd->vdev_child[c];
+
+		if ((error = vdev_open(cvd)) != 0) {
+			lasterror = error;
+			numerrors++;
+			continue;
+		}
+	}
+
+	if (too_many_errors(vd, numerrors)) {
+		vd->vdev_stat.vs_aux = VDEV_AUX_NO_REPLICAS;
+		return (lasterror);
+	}
+
+	*asize = 0;
+	*ashift = 0;
+
+	return (0);
+}
+
+static void
+vdev_root_close(vdev_t *vd)
+{
+	int c;
+
+	for (c = 0; c < vd->vdev_children; c++)
+		vdev_close(vd->vdev_child[c]);
+}
+
+static void
+vdev_root_state_change(vdev_t *vd, int faulted, int degraded)
+{
+	if (too_many_errors(vd, faulted))
+		vdev_set_state(vd, B_FALSE, VDEV_STATE_CANT_OPEN,
+		    VDEV_AUX_NO_REPLICAS);
+	else if (degraded != 0)
+		vdev_set_state(vd, B_FALSE, VDEV_STATE_DEGRADED, VDEV_AUX_NONE);
+	else
+		vdev_set_state(vd, B_FALSE, VDEV_STATE_HEALTHY, VDEV_AUX_NONE);
+}
+
+vdev_ops_t vdev_root_ops = {
+	vdev_root_open,
+	vdev_root_close,
+	vdev_default_asize,
+	NULL,			/* io_start - not applicable to the root */
+	NULL,			/* io_done - not applicable to the root */
+	vdev_root_state_change,
+	VDEV_TYPE_ROOT,		/* name of this vdev type */
+	B_FALSE			/* not a leaf vdev */
+};