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 /*
23 * Copyright (c) 2012 by Delphix. All rights reserved.
24 * Copyright (c) 2012 Joyent, Inc. All rights reserved.
25 */
26
27 #ifdef _KERNEL
28 #include <sys/systm.h>
29 #else
30 #include <errno.h>
31 #include <string.h>
32 #endif
33 #include <sys/debug.h>
34 #include <sys/fs/zfs.h>
35 #include <sys/inttypes.h>
36 #include <sys/types.h>
37 #include "zfeature_common.h"
38
39 /*
40 * Set to disable all feature checks while opening pools, allowing pools with
41 * unsupported features to be opened. Set for testing only.
42 */
43 boolean_t zfeature_checks_disable = B_FALSE;
44
45 zfeature_info_t spa_feature_table[SPA_FEATURES];
46
47 /*
48 * Valid characters for feature guids. This list is mainly for aesthetic
49 * purposes and could be expanded in the future. There are different allowed
50 * characters in the guids reverse dns portion (before the colon) and its
51 * short name (after the colon).
52 */
53 static int
54 valid_char(char c, boolean_t after_colon)
55 {
56 return ((c >= 'a' && c <= 'z') ||
57 (c >= '0' && c <= '9') ||
58 c == (after_colon ? '_' : '.'));
59 }
60
61 /*
62 * Every feature guid must contain exactly one colon which separates a reverse
63 * dns organization name from the feature's "short" name (e.g.
64 * "com.company:feature_name").
65 */
66 boolean_t
67 zfeature_is_valid_guid(const char *name)
68 {
69 int i;
70 boolean_t has_colon = B_FALSE;
71
72 i = 0;
73 while (name[i] != '\0') {
74 char c = name[i++];
75 if (c == ':') {
76 if (has_colon)
77 return (B_FALSE);
78 has_colon = B_TRUE;
79 continue;
80 }
81 if (!valid_char(c, has_colon))
82 return (B_FALSE);
83 }
84
85 return (has_colon);
86 }
87
88 boolean_t
89 zfeature_is_supported(const char *guid)
90 {
91 if (zfeature_checks_disable)
92 return (B_TRUE);
93
94 return (0 == zfeature_lookup_guid(guid, NULL));
95 }
96
97 int
98 zfeature_lookup_guid(const char *guid, zfeature_info_t **res)
99 {
100 for (int i = 0; i < SPA_FEATURES; i++) {
101 zfeature_info_t *feature = &spa_feature_table[i];
102 if (strcmp(guid, feature->fi_guid) == 0) {
103 if (res != NULL)
104 *res = feature;
105 return (0);
106 }
107 }
108
109 return (ENOENT);
110 }
111
112 int
113 zfeature_lookup_name(const char *name, zfeature_info_t **res)
114 {
115 for (int i = 0; i < SPA_FEATURES; i++) {
116 zfeature_info_t *feature = &spa_feature_table[i];
117 if (strcmp(name, feature->fi_uname) == 0) {
118 if (res != NULL)
119 *res = feature;
120 return (0);
121 }
122 }
123
124 return (ENOENT);
125 }
126
127 static void
128 zfeature_register(int fid, const char *guid, const char *name, const char *desc,
129 boolean_t readonly, boolean_t mos, zfeature_info_t **deps)
130 {
131 zfeature_info_t *feature = &spa_feature_table[fid];
132 static zfeature_info_t *nodeps[] = { NULL };
133
134 ASSERT(name != NULL);
135 ASSERT(desc != NULL);
136 ASSERT(!readonly || !mos);
137 ASSERT3U(fid, <, SPA_FEATURES);
138 ASSERT(zfeature_is_valid_guid(guid));
139
140 if (deps == NULL)
141 deps = nodeps;
142
143 feature->fi_guid = guid;
144 feature->fi_uname = name;
145 feature->fi_desc = desc;
146 feature->fi_can_readonly = readonly;
147 feature->fi_mos = mos;
148 feature->fi_depends = deps;
149 }
150
151 void
152 zpool_feature_init(void)
153 {
154 zfeature_register(SPA_FEATURE_ASYNC_DESTROY,
155 "com.delphix:async_destroy", "async_destroy",
156 "Destroy filesystems asynchronously.", B_TRUE, B_FALSE, NULL);
157 zfeature_register(SPA_FEATURE_EMPTY_BPOBJ,
158 "com.delphix:empty_bpobj", "empty_bpobj",
159 "Snapshots use less space.", B_TRUE, B_FALSE, NULL);
160 zfeature_register(SPA_FEATURE_FS_SS_LIMIT,
161 "com.joyent:filesystem_limits", "filesystem_limits",
162 "Filesystem and snapshot limits.", B_TRUE, B_FALSE, NULL);
163 }