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/inttypes.h>
  38 #include <sys/types.h>
  39 #include "zfeature_common.h"
  40
  41 /*
  42  * Set to disable all feature checks while opening pools, allowing pools with
  43  * unsupported features to be opened. Set for testing only.
  44  */
  45 boolean_t zfeature_checks_disable = B_FALSE;
  46
  47 zfeature_info_t spa_feature_table[SPA_FEATURES];
  48
  49 /*
  50  * Valid characters for feature guids. This list is mainly for aesthetic
  51  * purposes and could be expanded in the future. There are different allowed
  52  * characters in the guids reverse dns portion (before the colon) and its
  53  * short name (after the colon).
  54  */
  55 static int
  56 valid_char(char c, boolean_t after_colon)
  57 {
  58         return ((c >= 'a' && c <= 'z') ||
  59             (c >= '0' && c <= '9') ||
  60             (after_colon && c == '_') ||
  61             (!after_colon && (c == '.' || c == '-')));
  62 }
  63
  64 /*
  65  * Every feature guid must contain exactly one colon which separates a reverse
  66  * dns organization name from the feature's "short" name (e.g.
  67  * "com.company:feature_name").
  68  */
  69 boolean_t
  70 zfeature_is_valid_guid(const char *name)
  71 {
  72         int i;
  73         boolean_t has_colon = B_FALSE;
  74
  75         i = 0;
  76         while (name[i] != '\0') {
  77                 char c = name[i++];
  78                 if (c == ':') {
  79                         if (has_colon)
  80                                 return (B_FALSE);
  81                         has_colon = B_TRUE;
  82                         continue;
  83                 }
  84                 if (!valid_char(c, has_colon))
  85                         return (B_FALSE);
  86         }
  87
  88         return (has_colon);
  89 }
  90
  91 boolean_t
  92 zfeature_is_supported(const char *guid)
  93 {
  94         if (zfeature_checks_disable)
  95                 return (B_TRUE);
  96
  97         for (spa_feature_t i = 0; i < SPA_FEATURES; i++) {
  98                 zfeature_info_t *feature = &spa_feature_table[i];
  99                 if (strcmp(guid, feature->fi_guid) == 0)
 100                         return (B_TRUE);
 101         }
 102         return (B_FALSE);
 103 }
 104
 105 int
 106 zfeature_lookup_name(const char *name, spa_feature_t *res)
 107 {
 108         for (spa_feature_t i = 0; i < SPA_FEATURES; i++) {
 109                 zfeature_info_t *feature = &spa_feature_table[i];
 110                 if (strcmp(name, feature->fi_uname) == 0) {
 111                         if (res != NULL)
 112                                 *res = i;
 113                         return (0);
 114                 }
 115         }
 116
 117         return (ENOENT);
 118 }
 119
 120 boolean_t
 121 zfeature_depends_on(spa_feature_t fid, spa_feature_t check) {
 122         zfeature_info_t *feature = &spa_feature_table[fid];
 123
 124         for (int i = 0; feature->fi_depends[i] != SPA_FEATURE_NONE; i++) {
 125                 if (feature->fi_depends[i] == check)
 126                         return (B_TRUE);
 127         }
 128         return (B_FALSE);
 129 }
 130
 131 static void
 132 zfeature_register(spa_feature_t fid, const char *guid, const char *name,
 133     const char *desc, boolean_t readonly, boolean_t mos,
 134     boolean_t activate_on_enable, const spa_feature_t *deps)
 135 {
 136         zfeature_info_t *feature = &spa_feature_table[fid];
 137         static spa_feature_t nodeps[] = { SPA_FEATURE_NONE };
 138
 139         ASSERT(name != NULL);
 140         ASSERT(desc != NULL);
 141         ASSERT(!readonly || !mos);
 142         ASSERT3U(fid, <, SPA_FEATURES);
 143         ASSERT(zfeature_is_valid_guid(guid));
 144
 145         if (deps == NULL)
 146                 deps = nodeps;
 147
 148         feature->fi_feature = fid;
 149         feature->fi_guid = guid;
 150         feature->fi_uname = name;
 151         feature->fi_desc = desc;
 152         feature->fi_can_readonly = readonly;
 153         feature->fi_mos = mos;
 154         feature->fi_activate_on_enable = activate_on_enable;
 155         feature->fi_depends = deps;
 156 }
 157
 158 void
 159 zpool_feature_init(void)
 160 {
 161         zfeature_register(SPA_FEATURE_ASYNC_DESTROY,
 162             "com.delphix:async_destroy", "async_destroy",
 163             "Destroy filesystems asynchronously.", B_TRUE, B_FALSE,
 164             B_FALSE, NULL);
 165
 166         zfeature_register(SPA_FEATURE_EMPTY_BPOBJ,
 167             "com.delphix:empty_bpobj", "empty_bpobj",
 168             "Snapshots use less space.", B_TRUE, B_FALSE,
 169             B_FALSE, NULL);
 170
 171         zfeature_register(SPA_FEATURE_LZ4_COMPRESS,
 172             "org.illumos:lz4_compress", "lz4_compress",
 173             "LZ4 compression algorithm support.", B_FALSE, B_FALSE,
 174             B_TRUE, NULL);
 175
 176         zfeature_register(SPA_FEATURE_MULTI_VDEV_CRASH_DUMP,
 177             "com.joyent:multi_vdev_crash_dump", "multi_vdev_crash_dump",
 178             "Crash dumps to multiple vdev pools.", B_FALSE, B_FALSE,
 179             B_FALSE, NULL);
 180
 181         zfeature_register(SPA_FEATURE_SPACEMAP_HISTOGRAM,
 182             "com.delphix:spacemap_histogram", "spacemap_histogram",
 183             "Spacemaps maintain space histograms.", B_TRUE, B_FALSE,
 184             B_FALSE, NULL);
 185
 186         zfeature_register(SPA_FEATURE_ENABLED_TXG,
 187             "com.delphix:enabled_txg", "enabled_txg",
 188             "Record txg at which a feature is enabled", B_TRUE, B_FALSE,
 189             B_FALSE, NULL);
 190
 191         static spa_feature_t hole_birth_deps[] = { SPA_FEATURE_ENABLED_TXG,
 192             SPA_FEATURE_NONE };
 193         zfeature_register(SPA_FEATURE_HOLE_BIRTH,
 194             "com.delphix:hole_birth", "hole_birth",
 195             "Retain hole birth txg for more precise zfs send",
 196             B_FALSE, B_TRUE, B_TRUE, hole_birth_deps);
 197
 198         zfeature_register(SPA_FEATURE_EXTENSIBLE_DATASET,
 199             "com.delphix:extensible_dataset", "extensible_dataset",
 200             "Enhanced dataset functionality, used by other features.",
 201             B_FALSE, B_FALSE, B_FALSE, NULL);
 202
 203         static const spa_feature_t bookmarks_deps[] = {
 204                 SPA_FEATURE_EXTENSIBLE_DATASET,
 205                 SPA_FEATURE_NONE
 206         };
 207         zfeature_register(SPA_FEATURE_BOOKMARKS,
 208             "com.delphix:bookmarks", "bookmarks",
 209             "\"zfs bookmark\" command",
 210             B_TRUE, B_FALSE, B_FALSE, bookmarks_deps);
 211
 212         static const spa_feature_t filesystem_limits_deps[] = {
 213             SPA_FEATURE_EXTENSIBLE_DATASET,
 214             SPA_FEATURE_NONE
 215         };
 216         zfeature_register(SPA_FEATURE_FS_SS_LIMIT,
 217             "com.joyent:filesystem_limits", "filesystem_limits",
 218             "Filesystem and snapshot limits.", B_TRUE, B_FALSE, B_FALSE,
 219             filesystem_limits_deps);
 220
 221         zfeature_register(SPA_FEATURE_EMBEDDED_DATA,
 222             "com.delphix:embedded_data", "embedded_data",
 223             "Blocks which compress very well use even less space.",
 224             B_FALSE, B_TRUE, B_TRUE, NULL);
 225
 226         static const spa_feature_t large_blocks_deps[] = {
 227                 SPA_FEATURE_EXTENSIBLE_DATASET,
 228                 SPA_FEATURE_NONE
 229         };
 230         zfeature_register(SPA_FEATURE_LARGE_BLOCKS,
 231             "org.open-zfs:large_blocks", "large_blocks",
 232             "Support for blocks larger than 128KB.", B_FALSE, B_FALSE, B_FALSE,
 233             large_blocks_deps);
 234 }