aboutsummaryrefslogtreecommitdiffstats
path: root/module/zfs/zfeature_common.c
blob: 33d15133e20e989a5a90e0fd0c759d701f940ca5 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
/*
 * 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 (c) 2012 by Delphix. All rights reserved.
 */

#ifdef _KERNEL
#include <sys/systm.h>
#else
#include <errno.h>
#include <string.h>
#endif
#include <sys/debug.h>
#include <sys/fs/zfs.h>
#include <sys/inttypes.h>
#include <sys/types.h>
#include "zfeature_common.h"

/*
 * Set to disable all feature checks while opening pools, allowing pools with
 * unsupported features to be opened. Set for testing only.
 */
boolean_t zfeature_checks_disable = B_FALSE;

zfeature_info_t spa_feature_table[SPA_FEATURES];

/*
 * Valid characters for feature guids. This list is mainly for aesthetic
 * purposes and could be expanded in the future. There are different allowed
 * characters in the guids reverse dns portion (before the colon) and its
 * short name (after the colon).
 */
static int
valid_char(char c, boolean_t after_colon)
{
	return ((c >= 'a' && c <= 'z') ||
	    (c >= '0' && c <= '9') ||
	    c == (after_colon ? '_' : '.'));
}

/*
 * Every feature guid must contain exactly one colon which separates a reverse
 * dns organization name from the feature's "short" name (e.g.
 * "com.company:feature_name").
 */
boolean_t
zfeature_is_valid_guid(const char *name)
{
	int i;
	boolean_t has_colon = B_FALSE;

	i = 0;
	while (name[i] != '\0') {
		char c = name[i++];
		if (c == ':') {
			if (has_colon)
				return (B_FALSE);
			has_colon = B_TRUE;
			continue;
		}
		if (!valid_char(c, has_colon))
			return (B_FALSE);
	}

	return (has_colon);
}

boolean_t
zfeature_is_supported(const char *guid)
{
	if (zfeature_checks_disable)
		return (B_TRUE);

	return (0 == zfeature_lookup_guid(guid, NULL));
}

int
zfeature_lookup_guid(const char *guid, zfeature_info_t **res)
{
	int i;

	for (i = 0; i < SPA_FEATURES; i++) {
		zfeature_info_t *feature = &spa_feature_table[i];
		if (strcmp(guid, feature->fi_guid) == 0) {
			if (res != NULL)
				*res = feature;
			return (0);
		}
	}

	return (ENOENT);
}

int
zfeature_lookup_name(const char *name, zfeature_info_t **res)
{
	int i;

	for (i = 0; i < SPA_FEATURES; i++) {
		zfeature_info_t *feature = &spa_feature_table[i];
		if (strcmp(name, feature->fi_uname) == 0) {
			if (res != NULL)
				*res = feature;
			return (0);
		}
	}

	return (ENOENT);
}

static void
zfeature_register(int fid, const char *guid, const char *name, const char *desc,
    boolean_t readonly, boolean_t mos, zfeature_info_t **deps)
{
	zfeature_info_t *feature = &spa_feature_table[fid];
	static zfeature_info_t *nodeps[] = { NULL };

	ASSERT(name != NULL);
	ASSERT(desc != NULL);
	ASSERT(!readonly || !mos);
	ASSERT3U(fid, <, SPA_FEATURES);
	ASSERT(zfeature_is_valid_guid(guid));

	if (deps == NULL)
		deps = nodeps;

	feature->fi_guid = guid;
	feature->fi_uname = name;
	feature->fi_desc = desc;
	feature->fi_can_readonly = readonly;
	feature->fi_mos = mos;
	feature->fi_depends = deps;
}

void
zpool_feature_init(void)
{
	zfeature_register(SPA_FEATURE_ASYNC_DESTROY,
	    "com.delphix:async_destroy", "async_destroy",
	    "Destroy filesystems asynchronously.", B_TRUE, B_FALSE, NULL);
}