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-rw-r--r--uts/common/fs/zfs/vdev_root.c116
1 files changed, 116 insertions, 0 deletions
diff --git a/uts/common/fs/zfs/vdev_root.c b/uts/common/fs/zfs/vdev_root.c
new file mode 100644
index 000000000000..879f78f3a5b3
--- /dev/null
+++ b/uts/common/fs/zfs/vdev_root.c
@@ -0,0 +1,116 @@
+/*
+ * 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 2010 Sun Microsystems, Inc. All rights reserved.
+ * Use is subject to license terms.
+ */
+
+#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.
+ */
+static int
+too_many_errors(vdev_t *vd, int numerrors)
+{
+ ASSERT3U(numerrors, <=, vd->vdev_children);
+ return (numerrors > 0);
+}
+
+static int
+vdev_root_open(vdev_t *vd, uint64_t *asize, uint64_t *ashift)
+{
+ int lasterror = 0;
+ int numerrors = 0;
+
+ if (vd->vdev_children == 0) {
+ vd->vdev_stat.vs_aux = VDEV_AUX_BAD_LABEL;
+ return (EINVAL);
+ }
+
+ vdev_open_children(vd);
+
+ for (int c = 0; c < vd->vdev_children; c++) {
+ vdev_t *cvd = vd->vdev_child[c];
+
+ if (cvd->vdev_open_error && !cvd->vdev_islog) {
+ lasterror = cvd->vdev_open_error;
+ numerrors++;
+ }
+ }
+
+ 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)
+{
+ for (int 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) {
+ 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,
+ NULL,
+ NULL,
+ VDEV_TYPE_ROOT, /* name of this vdev type */
+ B_FALSE /* not a leaf vdev */
+};