xref: /titanic_51/usr/src/common/zfs/zfeature_common.c (revision a9478106a12424322498e53cf7cd75bd8a4d6004)
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) 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 	return (0 == zfeature_lookup_guid(guid, NULL));
96 }
97 
98 int
99 zfeature_lookup_guid(const char *guid, zfeature_info_t **res)
100 {
101 	for (int i = 0; i < SPA_FEATURES; i++) {
102 		zfeature_info_t *feature = &spa_feature_table[i];
103 		if (strcmp(guid, feature->fi_guid) == 0) {
104 			if (res != NULL)
105 				*res = feature;
106 			return (0);
107 		}
108 	}
109 
110 	return (ENOENT);
111 }
112 
113 int
114 zfeature_lookup_name(const char *name, zfeature_info_t **res)
115 {
116 	for (int i = 0; i < SPA_FEATURES; i++) {
117 		zfeature_info_t *feature = &spa_feature_table[i];
118 		if (strcmp(name, feature->fi_uname) == 0) {
119 			if (res != NULL)
120 				*res = feature;
121 			return (0);
122 		}
123 	}
124 
125 	return (ENOENT);
126 }
127 
128 static void
129 zfeature_register(int fid, const char *guid, const char *name, const char *desc,
130     boolean_t readonly, boolean_t mos, zfeature_info_t **deps)
131 {
132 	zfeature_info_t *feature = &spa_feature_table[fid];
133 	static zfeature_info_t *nodeps[] = { NULL };
134 
135 	ASSERT(name != NULL);
136 	ASSERT(desc != NULL);
137 	ASSERT(!readonly || !mos);
138 	ASSERT3U(fid, <, SPA_FEATURES);
139 	ASSERT(zfeature_is_valid_guid(guid));
140 
141 	if (deps == NULL)
142 		deps = nodeps;
143 
144 	feature->fi_guid = guid;
145 	feature->fi_uname = name;
146 	feature->fi_desc = desc;
147 	feature->fi_can_readonly = readonly;
148 	feature->fi_mos = mos;
149 	feature->fi_depends = deps;
150 }
151 
152 void
153 zpool_feature_init(void)
154 {
155 	zfeature_register(SPA_FEATURE_ASYNC_DESTROY,
156 	    "com.delphix:async_destroy", "async_destroy",
157 	    "Destroy filesystems asynchronously.", B_TRUE, B_FALSE, NULL);
158 	zfeature_register(SPA_FEATURE_EMPTY_BPOBJ,
159 	    "com.delphix:empty_bpobj", "empty_bpobj",
160 	    "Snapshots use less space.", B_TRUE, B_FALSE, NULL);
161 	zfeature_register(SPA_FEATURE_LZ4_COMPRESS,
162 	    "org.illumos:lz4_compress", "lz4_compress",
163 	    "LZ4 compression algorithm support.", B_FALSE, B_FALSE, NULL);
164 	zfeature_register(SPA_FEATURE_MULTI_VDEV_CRASH_DUMP,
165 	    "com.joyent:multi_vdev_crash_dump", "multi_vdev_crash_dump",
166 	    "Crash dumps to multiple vdev pools.", B_FALSE, B_FALSE, NULL);
167 }
168