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