xref: /illumos-gate/usr/src/common/zfs/zfeature_common.c (revision faac71c002f7c7a98741f991b25937b24f309df0)
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) 2013 by Delphix. All rights reserved.
24  * Copyright (c) 2013 by Saso Kiselkov. All rights reserved.
25  * Copyright (c) 2013, Joyent, Inc. All rights reserved.
26  */
27 
28 #ifdef _KERNEL
29 #include <sys/systm.h>
30 #else
31 #include <errno.h>
32 #include <string.h>
33 #endif
34 #include <sys/debug.h>
35 #include <sys/fs/zfs.h>
36 #include <sys/inttypes.h>
37 #include <sys/types.h>
38 #include "zfeature_common.h"
39 
40 /*
41  * Set to disable all feature checks while opening pools, allowing pools with
42  * unsupported features to be opened. Set for testing only.
43  */
44 boolean_t zfeature_checks_disable = B_FALSE;
45 
46 zfeature_info_t spa_feature_table[SPA_FEATURES];
47 
48 /*
49  * Valid characters for feature guids. This list is mainly for aesthetic
50  * purposes and could be expanded in the future. There are different allowed
51  * characters in the guids reverse dns portion (before the colon) and its
52  * short name (after the colon).
53  */
54 static int
55 valid_char(char c, boolean_t after_colon)
56 {
57 	return ((c >= 'a' && c <= 'z') ||
58 	    (c >= '0' && c <= '9') ||
59 	    c == (after_colon ? '_' : '.'));
60 }
61 
62 /*
63  * Every feature guid must contain exactly one colon which separates a reverse
64  * dns organization name from the feature's "short" name (e.g.
65  * "com.company:feature_name").
66  */
67 boolean_t
68 zfeature_is_valid_guid(const char *name)
69 {
70 	int i;
71 	boolean_t has_colon = B_FALSE;
72 
73 	i = 0;
74 	while (name[i] != '\0') {
75 		char c = name[i++];
76 		if (c == ':') {
77 			if (has_colon)
78 				return (B_FALSE);
79 			has_colon = B_TRUE;
80 			continue;
81 		}
82 		if (!valid_char(c, has_colon))
83 			return (B_FALSE);
84 	}
85 
86 	return (has_colon);
87 }
88 
89 boolean_t
90 zfeature_is_supported(const char *guid)
91 {
92 	if (zfeature_checks_disable)
93 		return (B_TRUE);
94 
95 	for (spa_feature_t i = 0; i < SPA_FEATURES; i++) {
96 		zfeature_info_t *feature = &spa_feature_table[i];
97 		if (strcmp(guid, feature->fi_guid) == 0)
98 			return (B_TRUE);
99 	}
100 	return (B_FALSE);
101 }
102 
103 int
104 zfeature_lookup_name(const char *name, spa_feature_t *res)
105 {
106 	for (spa_feature_t i = 0; i < SPA_FEATURES; i++) {
107 		zfeature_info_t *feature = &spa_feature_table[i];
108 		if (strcmp(name, feature->fi_uname) == 0) {
109 			if (res != NULL)
110 				*res = i;
111 			return (0);
112 		}
113 	}
114 
115 	return (ENOENT);
116 }
117 
118 boolean_t
119 zfeature_depends_on(spa_feature_t fid, spa_feature_t check) {
120 	zfeature_info_t *feature = &spa_feature_table[fid];
121 
122 	for (int i = 0; feature->fi_depends[i] != SPA_FEATURE_NONE; i++) {
123 		if (feature->fi_depends[i] == check)
124 			return (B_TRUE);
125 	}
126 	return (B_FALSE);
127 }
128 
129 static void
130 zfeature_register(spa_feature_t fid, const char *guid, const char *name,
131     const char *desc, boolean_t readonly, boolean_t mos,
132     boolean_t activate_on_enable, const spa_feature_t *deps)
133 {
134 	zfeature_info_t *feature = &spa_feature_table[fid];
135 	static spa_feature_t nodeps[] = { SPA_FEATURE_NONE };
136 
137 	ASSERT(name != NULL);
138 	ASSERT(desc != NULL);
139 	ASSERT(!readonly || !mos);
140 	ASSERT3U(fid, <, SPA_FEATURES);
141 	ASSERT(zfeature_is_valid_guid(guid));
142 
143 	if (deps == NULL)
144 		deps = nodeps;
145 
146 	feature->fi_feature = fid;
147 	feature->fi_guid = guid;
148 	feature->fi_uname = name;
149 	feature->fi_desc = desc;
150 	feature->fi_can_readonly = readonly;
151 	feature->fi_mos = mos;
152 	feature->fi_activate_on_enable = activate_on_enable;
153 	feature->fi_depends = deps;
154 }
155 
156 void
157 zpool_feature_init(void)
158 {
159 	zfeature_register(SPA_FEATURE_ASYNC_DESTROY,
160 	    "com.delphix:async_destroy", "async_destroy",
161 	    "Destroy filesystems asynchronously.", B_TRUE, B_FALSE,
162 	    B_FALSE, NULL);
163 
164 	zfeature_register(SPA_FEATURE_EMPTY_BPOBJ,
165 	    "com.delphix:empty_bpobj", "empty_bpobj",
166 	    "Snapshots use less space.", B_TRUE, B_FALSE,
167 	    B_FALSE, NULL);
168 
169 	zfeature_register(SPA_FEATURE_LZ4_COMPRESS,
170 	    "org.illumos:lz4_compress", "lz4_compress",
171 	    "LZ4 compression algorithm support.", B_FALSE, B_FALSE,
172 	    B_FALSE, NULL);
173 
174 	zfeature_register(SPA_FEATURE_MULTI_VDEV_CRASH_DUMP,
175 	    "com.joyent:multi_vdev_crash_dump", "multi_vdev_crash_dump",
176 	    "Crash dumps to multiple vdev pools.", B_FALSE, B_FALSE,
177 	    B_FALSE, NULL);
178 
179 	zfeature_register(SPA_FEATURE_SPACEMAP_HISTOGRAM,
180 	    "com.delphix:spacemap_histogram", "spacemap_histogram",
181 	    "Spacemaps maintain space histograms.", B_TRUE, B_FALSE,
182 	    B_FALSE, NULL);
183 
184 	zfeature_register(SPA_FEATURE_ENABLED_TXG,
185 	    "com.delphix:enabled_txg", "enabled_txg",
186 	    "Record txg at which a feature is enabled", B_TRUE, B_FALSE,
187 	    B_FALSE, NULL);
188 
189 	static spa_feature_t hole_birth_deps[] = { SPA_FEATURE_ENABLED_TXG,
190 	    SPA_FEATURE_NONE };
191 	zfeature_register(SPA_FEATURE_HOLE_BIRTH,
192 	    "com.delphix:hole_birth", "hole_birth",
193 	    "Retain hole birth txg for more precise zfs send",
194 	    B_FALSE, B_TRUE, B_TRUE, hole_birth_deps);
195 
196 	zfeature_register(SPA_FEATURE_EXTENSIBLE_DATASET,
197 	    "com.delphix:extensible_dataset", "extensible_dataset",
198 	    "Enhanced dataset functionality, used by other features.",
199 	    B_FALSE, B_FALSE, B_FALSE, NULL);
200 
201 	static const spa_feature_t bookmarks_deps[] = {
202 		SPA_FEATURE_EXTENSIBLE_DATASET,
203 		SPA_FEATURE_NONE
204 	};
205 	zfeature_register(SPA_FEATURE_BOOKMARKS,
206 	    "com.delphix:bookmarks", "bookmarks",
207 	    "\"zfs bookmark\" command",
208 	    B_TRUE, B_FALSE, B_FALSE, bookmarks_deps);
209 }
210