[mirror_zfs.git] / module / zfs / vdev_missing.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.
 */

/*
 * The 'missing' vdev is a special vdev type used only during import.  It
 * signifies a placeholder in the root vdev for some vdev that we know is
 * missing.  We pass it down to the kernel to allow the rest of the
 * configuration to parsed and an attempt made to open all available devices.
 * Because its GUID is always 0, we know that the guid sum will mismatch and we
 * won't be able to open the pool anyway.
 */

#include <sys/zfs_context.h>
#include <sys/spa.h>
#include <sys/vdev_impl.h>
#include <sys/fs/zfs.h>
#include <sys/zio.h>

/* ARGSUSED */
static int
vdev_missing_open(vdev_t *vd, uint64_t *psize, uint64_t *ashift)
{
	/*
	 * Really this should just fail.  But then the root vdev will be in the
	 * faulted state with VDEV_AUX_NO_REPLICAS, when what we really want is
	 * VDEV_AUX_BAD_GUID_SUM.  So we pretend to succeed, knowing that we
	 * will fail the GUID sum check before ever trying to open the pool.
	 */
	*psize = 0;
	*ashift = 0;
	return (0);
}

/* ARGSUSED */
static void
vdev_missing_close(vdev_t *vd)
{
}

/* ARGSUSED */
static int
vdev_missing_io_start(zio_t *zio)
{
	zio->io_error = ENOTSUP;
	return (ZIO_PIPELINE_CONTINUE);
}

/* ARGSUSED */
static void
vdev_missing_io_done(zio_t *zio)
{
}

vdev_ops_t vdev_missing_ops = {
	vdev_missing_open,
	vdev_missing_close,
	vdev_default_asize,
	vdev_missing_io_start,
	vdev_missing_io_done,
	NULL,
	NULL,
	NULL,
	VDEV_TYPE_MISSING,	/* name of this vdev type */
	B_TRUE			/* leaf vdev */
};

vdev_ops_t vdev_hole_ops = {
	vdev_missing_open,
	vdev_missing_close,
	vdev_default_asize,
	vdev_missing_io_start,
	vdev_missing_io_done,
	NULL,
	NULL,
	NULL,
	VDEV_TYPE_HOLE,		/* name of this vdev type */
	B_TRUE			/* 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	/*
428870ff	22	* Copyright 2010 Sun Microsystems, Inc. All rights reserved.
34dc7c2f BB	23	* Use is subject to license terms.
	24	*/
	25
34dc7c2f BB	26	/*
	27	* The 'missing' vdev is a special vdev type used only during import. It
	28	* signifies a placeholder in the root vdev for some vdev that we know is
	29	* missing. We pass it down to the kernel to allow the rest of the
	30	* configuration to parsed and an attempt made to open all available devices.
	31	* Because its GUID is always 0, we know that the guid sum will mismatch and we
	32	* won't be able to open the pool anyway.
	33	*/
	34
	35	#include <sys/zfs_context.h>
	36	#include <sys/spa.h>
	37	#include <sys/vdev_impl.h>
	38	#include <sys/fs/zfs.h>
	39	#include <sys/zio.h>
	40
	41	/* ARGSUSED */
	42	static int
	43	vdev_missing_open(vdev_t vd, uint64_t psize, uint64_t *ashift)
	44	{
	45	/*
	46	* Really this should just fail. But then the root vdev will be in the
	47	* faulted state with VDEV_AUX_NO_REPLICAS, when what we really want is
	48	* VDEV_AUX_BAD_GUID_SUM. So we pretend to succeed, knowing that we
	49	* will fail the GUID sum check before ever trying to open the pool.
	50	*/
428870ff BB	51	*psize = 0;
428870ff BB	52	*ashift = 0;
34dc7c2f BB	53	return (0);
	54	}
	55
	56	/* ARGSUSED */
	57	static void
	58	vdev_missing_close(vdev_t *vd)
	59	{
	60	}
	61
	62	/* ARGSUSED */
	63	static int
	64	vdev_missing_io_start(zio_t *zio)
	65	{
	66	zio->io_error = ENOTSUP;
	67	return (ZIO_PIPELINE_CONTINUE);
	68	}
	69
	70	/* ARGSUSED */
b128c09f	71	static void
34dc7c2f BB	72	vdev_missing_io_done(zio_t *zio)
34dc7c2f BB	73	{
34dc7c2f BB	74	}
	75
	76	vdev_ops_t vdev_missing_ops = {
	77	vdev_missing_open,
	78	vdev_missing_close,
34dc7c2f BB	79	vdev_default_asize,
	80	vdev_missing_io_start,
	81	vdev_missing_io_done,
	82	NULL,
428870ff BB	83	NULL,
428870ff BB	84	NULL,
34dc7c2f BB	85	VDEV_TYPE_MISSING, /* name of this vdev type */
	86	B_TRUE /* leaf vdev */
	87	};
428870ff BB	88
	89	vdev_ops_t vdev_hole_ops = {
	90	vdev_missing_open,
	91	vdev_missing_close,
	92	vdev_default_asize,
	93	vdev_missing_io_start,
	94	vdev_missing_io_done,
	95	NULL,
	96	NULL,
	97	NULL,
	98	VDEV_TYPE_HOLE, /* name of this vdev type */
	99	B_TRUE /* leaf vdev */
	100	};