freebsd-nq/module/zfs/vdev_root.c
George Amanakis 1b664952ae
Enable splitting mirrors with indirect vdevs
When a top-level vdev is removed from a pool it is converted to an
indirect vdev. Until now splitting such mirrored pools was not possible
with zpool split. This patch enables handling of indirect vdevs and
splitting of those pools with zpool split.

Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: George Amanakis <gamanakis@gmail.com>
Closes #10283
2020-05-06 10:32:28 -07:00

158 lines
4.0 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.
*/
/*
* Copyright (c) 2012, 2016 by Delphix. All rights reserved.
*/
#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.
*/
static uint64_t
vdev_root_core_tvds(vdev_t *vd)
{
uint64_t tvds = 0;
for (uint64_t c = 0; c < vd->vdev_children; c++) {
vdev_t *cvd = vd->vdev_child[c];
if (!cvd->vdev_ishole && !cvd->vdev_islog &&
cvd->vdev_ops != &vdev_indirect_ops) {
tvds++;
}
}
return (tvds);
}
/*
* 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 boolean_t
too_many_errors(vdev_t *vd, uint64_t numerrors)
{
uint64_t tvds;
if (numerrors == 0)
return (B_FALSE);
tvds = vdev_root_core_tvds(vd);
ASSERT3U(numerrors, <=, tvds);
if (numerrors == tvds)
return (B_TRUE);
return (numerrors > spa_missing_tvds_allowed(vd->vdev_spa));
}
static int
vdev_root_open(vdev_t *vd, uint64_t *asize, uint64_t *max_asize,
uint64_t *ashift)
{
spa_t *spa = vd->vdev_spa;
int lasterror = 0;
int numerrors = 0;
if (vd->vdev_children == 0) {
vd->vdev_stat.vs_aux = VDEV_AUX_BAD_LABEL;
return (SET_ERROR(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 &&
cvd->vdev_ops != &vdev_indirect_ops) {
lasterror = cvd->vdev_open_error;
numerrors++;
}
}
if (spa_load_state(spa) != SPA_LOAD_NONE)
spa_set_missing_tvds(spa, numerrors);
if (too_many_errors(vd, numerrors)) {
vd->vdev_stat.vs_aux = VDEV_AUX_NO_REPLICAS;
return (lasterror);
}
*asize = 0;
*max_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 || faulted) {
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_op_open = vdev_root_open,
.vdev_op_close = vdev_root_close,
.vdev_op_asize = vdev_default_asize,
.vdev_op_io_start = NULL, /* not applicable to the root */
.vdev_op_io_done = NULL, /* not applicable to the root */
.vdev_op_state_change = vdev_root_state_change,
.vdev_op_need_resilver = NULL,
.vdev_op_hold = NULL,
.vdev_op_rele = NULL,
.vdev_op_remap = NULL,
.vdev_op_xlate = NULL,
.vdev_op_type = VDEV_TYPE_ROOT, /* name of this vdev type */
.vdev_op_leaf = B_FALSE /* not a leaf vdev */
};