vdev_missing.c revision 297078 
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 2010 Sun Microsystems, Inc.  All rights reserved.
23 * Use is subject to license terms.
24 */
25
26/*
27 * Copyright (c) 2012, 2014 by Delphix. All rights reserved.
28 */
29
30/*
31 * The 'missing' vdev is a special vdev type used only during import.  It
32 * signifies a placeholder in the root vdev for some vdev that we know is
33 * missing.  We pass it down to the kernel to allow the rest of the
34 * configuration to parsed and an attempt made to open all available devices.
35 * Because its GUID is always 0, we know that the guid sum will mismatch and we
36 * won't be able to open the pool anyway.
37 */
38
39#include <sys/zfs_context.h>
40#include <sys/spa.h>
41#include <sys/vdev_impl.h>
42#include <sys/fs/zfs.h>
43#include <sys/zio.h>
44
45/* ARGSUSED */
46static int
47vdev_missing_open(vdev_t *vd, uint64_t *psize, uint64_t *max_psize,
48    uint64_t *logical_ashift, uint64_t *physical_ashift)
49{
50	/*
51	 * Really this should just fail.  But then the root vdev will be in the
52	 * faulted state with VDEV_AUX_NO_REPLICAS, when what we really want is
53	 * VDEV_AUX_BAD_GUID_SUM.  So we pretend to succeed, knowing that we
54	 * will fail the GUID sum check before ever trying to open the pool.
55	 */
56	*psize = 0;
57	*max_psize = 0;
58	*logical_ashift = 0;
59	*physical_ashift = 0;
60	return (0);
61}
62
63/* ARGSUSED */
64static void
65vdev_missing_close(vdev_t *vd)
66{
67}
68
69/* ARGSUSED */
70static void
71vdev_missing_io_start(zio_t *zio)
72{
73	zio->io_error = SET_ERROR(ENOTSUP);
74	zio_execute(zio);
75}
76
77/* ARGSUSED */
78static void
79vdev_missing_io_done(zio_t *zio)
80{
81}
82
83vdev_ops_t vdev_missing_ops = {
84	vdev_missing_open,
85	vdev_missing_close,
86	vdev_default_asize,
87	vdev_missing_io_start,
88	vdev_missing_io_done,
89	NULL,
90	NULL,
91	NULL,
92	VDEV_TYPE_MISSING,	/* name of this vdev type */
93	B_TRUE			/* leaf vdev */
94};
95
96vdev_ops_t vdev_hole_ops = {
97	vdev_missing_open,
98	vdev_missing_close,
99	vdev_default_asize,
100	vdev_missing_io_start,
101	vdev_missing_io_done,
102	NULL,
103	NULL,
104	NULL,
105	VDEV_TYPE_HOLE,		/* name of this vdev type */
106	B_TRUE			/* leaf vdev */
107};
108