zfs/module/zfs/vdev_root.c

120 lines
3.0 KiB
C

/*
* 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;
int c;
if (vd->vdev_children == 0) {
vd->vdev_stat.vs_aux = VDEV_AUX_BAD_LABEL;
return (EINVAL);
}
vdev_open_children(vd);
for (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)
{
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) {
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 */
};