sys/cddl/contrib/opensolaris/common/zfs/zfeature_common.c

   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  * Copyright (c) 2014, Nexenta Systems, Inc. All rights reserved.
  27  */
  28
  29 #ifdef _KERNEL
  30 #include <sys/systm.h>
  31 #else
  32 #include <errno.h>
  33 #include <string.h>
  34 #endif
  35 #include <sys/debug.h>
  36 #include <sys/fs/zfs.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_TRUE, 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         static const spa_feature_t filesystem_limits_deps[] = {
 211             SPA_FEATURE_EXTENSIBLE_DATASET,
 212             SPA_FEATURE_NONE
 213         };
 214         zfeature_register(SPA_FEATURE_FS_SS_LIMIT,
 215             "com.joyent:filesystem_limits", "filesystem_limits",
 216             "Filesystem and snapshot limits.", B_TRUE, B_FALSE, B_FALSE,
 217             filesystem_limits_deps);
 218
 219         zfeature_register(SPA_FEATURE_EMBEDDED_DATA,
 220             "com.delphix:embedded_data", "embedded_data",
 221             "Blocks which compress very well use even less space.",
 222             B_FALSE, B_TRUE, B_TRUE, NULL);
 223 }