[mirror_zfs.git] / zfs / lib / libzpool / vdev_root.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 2007 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#pragma ident	"@(#)vdev_root.c	1.5	07/10/24 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.
 */
static int
too_many_errors(vdev_t *vd, int numerrors)
{
	ASSERT3U(numerrors, <=, vd->vdev_children);
	return (numerrors == vd->vdev_children);
}

static int
vdev_root_open(vdev_t *vd, uint64_t *asize, uint64_t *ashift)
{
	int c;
	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++) {
		vdev_t *cvd = vd->vdev_child[c];
		int error;

		if ((error = vdev_open(cvd)) != 0) {
			lasterror = error;
			numerrors++;
			continue;
		}
	}

	if (numerrors > 0) {
		if (!too_many_errors(vd, numerrors)) {
			/* XXX - should not be explicitly setting this state */
			vdev_set_state(vd, B_FALSE, VDEV_STATE_FAULTED,
			    VDEV_AUX_NO_REPLICAS);
		} else {
			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 (faulted) {
		if (too_many_errors(vd, faulted))
			vdev_set_state(vd, B_FALSE, VDEV_STATE_CANT_OPEN,
			    VDEV_AUX_NO_REPLICAS);
		else
			vdev_set_state(vd, B_FALSE, VDEV_STATE_FAULTED,
			    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,
	NULL,
	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 */
};
Commit	Line	Data
34dc7c2f BB	1	/*
	2	* CDDL HEADER START
	3	*
	4	* The contents of this file are subject to the terms of the
	5	* Common Development and Distribution License (the "License").
	6	* You may not use this file except in compliance with the License.
	7	*
	8	* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
	9	* or http://www.opensolaris.org/os/licensing.
	10	* See the License for the specific language governing permissions
	11	* and limitations under the License.
	12	*
	13	* When distributing Covered Code, include this CDDL HEADER in each
	14	* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
	15	* If applicable, add the following below this CDDL HEADER, with the
	16	* fields enclosed by brackets "[]" replaced with your own identifying
	17	* information: Portions Copyright [yyyy] [name of copyright owner]
	18	*
	19	* CDDL HEADER END
	20	*/
	21	/*
	22	* Copyright 2007 Sun Microsystems, Inc. All rights reserved.
	23	* Use is subject to license terms.
	24	*/
	25
	26	#pragma ident "@(#)vdev_root.c 1.5 07/10/24 SMI"
	27
	28	#include <sys/zfs_context.h>
	29	#include <sys/spa.h>
	30	#include <sys/vdev_impl.h>
	31	#include <sys/zio.h>
	32	#include <sys/fs/zfs.h>
	33
	34	/*
	35	* Virtual device vector for the pool's root vdev.
	36	*/
	37
	38	/*
	39	* We should be able to tolerate one failure with absolutely no damage
	40	* to our metadata. Two failures will take out space maps, a bunch of
	41	* indirect block trees, meta dnodes, dnodes, etc. Probably not a happy
	42	* place to live. When we get smarter, we can liberalize this policy.
	43	* e.g. If we haven't lost two consecutive top-level vdevs, then we are
	44	* probably fine. Adding bean counters during alloc/free can make this
	45	* future guesswork more accurate.
	46	*/
	47	static int
	48	too_many_errors(vdev_t *vd, int numerrors)
	49	{
	50	ASSERT3U(numerrors, <=, vd->vdev_children);
	51	return (numerrors == vd->vdev_children);
	52	}
	53
	54	static int
	55	vdev_root_open(vdev_t vd, uint64_t asize, uint64_t *ashift)
	56	{
	57	int c;
	58	int lasterror = 0;
	59	int numerrors = 0;
	60
	61	if (vd->vdev_children == 0) {
	62	vd->vdev_stat.vs_aux = VDEV_AUX_BAD_LABEL;
	63	return (EINVAL);
	64	}
65
66	for (c = 0; c < vd->vdev_children; c++) {
67	vdev_t *cvd = vd->vdev_child[c];
68	int error;
69
70	if ((error = vdev_open(cvd)) != 0) {
71	lasterror = error;
72	numerrors++;
73	continue;
74	}
75	}
76
77	if (numerrors > 0) {
78	if (!too_many_errors(vd, numerrors)) {
79	/* XXX - should not be explicitly setting this state */
80	vdev_set_state(vd, B_FALSE, VDEV_STATE_FAULTED,
81	VDEV_AUX_NO_REPLICAS);
82	} else {
83	vd->vdev_stat.vs_aux = VDEV_AUX_NO_REPLICAS;
84	return (lasterror);
85	}
86	}
87
88	*asize = 0;
89	*ashift = 0;
90
91	return (0);
92	}
93
94	static void
95	vdev_root_close(vdev_t *vd)
96	{
97	int c;
98
99	for (c = 0; c < vd->vdev_children; c++)
100	vdev_close(vd->vdev_child[c]);
101	}
102
103	static void
104	vdev_root_state_change(vdev_t *vd, int faulted, int degraded)
105	{
106	if (faulted) {
107	if (too_many_errors(vd, faulted))
108	vdev_set_state(vd, B_FALSE, VDEV_STATE_CANT_OPEN,
109	VDEV_AUX_NO_REPLICAS);
110	else
111	vdev_set_state(vd, B_FALSE, VDEV_STATE_FAULTED,
112	VDEV_AUX_NO_REPLICAS);
113	} else if (degraded) {
114	vdev_set_state(vd, B_FALSE, VDEV_STATE_DEGRADED, VDEV_AUX_NONE);
115	} else {
116	vdev_set_state(vd, B_FALSE, VDEV_STATE_HEALTHY, VDEV_AUX_NONE);
117	}
118	}
119
120	vdev_ops_t vdev_root_ops = {
121	vdev_root_open,
122	vdev_root_close,
123	NULL,
124	vdev_default_asize,
125	NULL, /* io_start - not applicable to the root */
126	NULL, /* io_done - not applicable to the root */
127	vdev_root_state_change,
128	VDEV_TYPE_ROOT, /* name of this vdev type */
129	B_FALSE /* not a leaf vdev */
130	};