xref: /titanic_51/usr/src/common/zfs/zfeature_common.c (revision a970c705050f9e90c4b6d7982a9b3211719353fb)
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  */
25 
26 #ifdef _KERNEL
27 #include <sys/systm.h>
28 #else
29 #include <errno.h>
30 #include <string.h>
31 #endif
32 #include <sys/debug.h>
33 #include <sys/fs/zfs.h>
34 #include <sys/inttypes.h>
35 #include <sys/types.h>
36 #include "zfeature_common.h"
37 
38 /*
39  * Set to disable all feature checks while opening pools, allowing pools with
40  * unsupported features to be opened. Set for testing only.
41  */
42 boolean_t zfeature_checks_disable = B_FALSE;
43 
44 zfeature_info_t spa_feature_table[SPA_FEATURES];
45 
46 /*
47  * Valid characters for feature guids. This list is mainly for aesthetic
48  * purposes and could be expanded in the future. There are different allowed
49  * characters in the guids reverse dns portion (before the colon) and its
50  * short name (after the colon).
51  */
52 static int
53 valid_char(char c, boolean_t after_colon)
54 {
55 	return ((c >= 'a' && c <= 'z') ||
56 	    (c >= '0' && c <= '9') ||
57 	    c == (after_colon ? '_' : '.'));
58 }
59 
60 /*
61  * Every feature guid must contain exactly one colon which separates a reverse
62  * dns organization name from the feature's "short" name (e.g.
63  * "com.company:feature_name").
64  */
65 boolean_t
66 zfeature_is_valid_guid(const char *name)
67 {
68 	int i;
69 	boolean_t has_colon = B_FALSE;
70 
71 	i = 0;
72 	while (name[i] != '\0') {
73 		char c = name[i++];
74 		if (c == ':') {
75 			if (has_colon)
76 				return (B_FALSE);
77 			has_colon = B_TRUE;
78 			continue;
79 		}
80 		if (!valid_char(c, has_colon))
81 			return (B_FALSE);
82 	}
83 
84 	return (has_colon);
85 }
86 
87 boolean_t
88 zfeature_is_supported(const char *guid)
89 {
90 	if (zfeature_checks_disable)
91 		return (B_TRUE);
92 
93 	return (0 == zfeature_lookup_guid(guid, NULL));
94 }
95 
96 int
97 zfeature_lookup_guid(const char *guid, zfeature_info_t **res)
98 {
99 	for (int i = 0; i < SPA_FEATURES; i++) {
100 		zfeature_info_t *feature = &spa_feature_table[i];
101 		if (strcmp(guid, feature->fi_guid) == 0) {
102 			if (res != NULL)
103 				*res = feature;
104 			return (0);
105 		}
106 	}
107 
108 	return (ENOENT);
109 }
110 
111 int
112 zfeature_lookup_name(const char *name, zfeature_info_t **res)
113 {
114 	for (int i = 0; i < SPA_FEATURES; i++) {
115 		zfeature_info_t *feature = &spa_feature_table[i];
116 		if (strcmp(name, feature->fi_uname) == 0) {
117 			if (res != NULL)
118 				*res = feature;
119 			return (0);
120 		}
121 	}
122 
123 	return (ENOENT);
124 }
125 
126 static void
127 zfeature_register(int fid, const char *guid, const char *name, const char *desc,
128     boolean_t readonly, boolean_t mos, zfeature_info_t **deps)
129 {
130 	zfeature_info_t *feature = &spa_feature_table[fid];
131 	static zfeature_info_t *nodeps[] = { NULL };
132 
133 	ASSERT(name != NULL);
134 	ASSERT(desc != NULL);
135 	ASSERT(!readonly || !mos);
136 	ASSERT3U(fid, <, SPA_FEATURES);
137 	ASSERT(zfeature_is_valid_guid(guid));
138 
139 	if (deps == NULL)
140 		deps = nodeps;
141 
142 	feature->fi_guid = guid;
143 	feature->fi_uname = name;
144 	feature->fi_desc = desc;
145 	feature->fi_can_readonly = readonly;
146 	feature->fi_mos = mos;
147 	feature->fi_depends = deps;
148 }
149 
150 void
151 zpool_feature_init(void)
152 {
153 	zfeature_register(SPA_FEATURE_ASYNC_DESTROY,
154 	    "com.delphix:async_destroy", "async_destroy",
155 	    "Destroy filesystems asynchronously.", B_TRUE, B_FALSE, NULL);
156 }
157