zfs/module/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) 2014, Nexenta Systems, 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             (after_colon && c == '_') ||
  60             (!after_colon && (c == '.' || c == '-')));
  61 }
  62
  63 /*
  64  * Every feature guid must contain exactly one colon which separates a reverse
  65  * dns organization name from the feature's "short" name (e.g.
  66  * "com.company:feature_name").
  67  */
  68 boolean_t
  69 zfeature_is_valid_guid(const char *name)
  70 {
  71         int i;
  72         boolean_t has_colon = B_FALSE;
  73
  74         i = 0;
  75         while (name[i] != '\0') {
  76                 char c = name[i++];
  77                 if (c == ':') {
  78                         if (has_colon)
  79                                 return (B_FALSE);
  80                         has_colon = B_TRUE;
  81                         continue;
  82                 }
  83                 if (!valid_char(c, has_colon))
  84                         return (B_FALSE);
  85         }
  86
  87         return (has_colon);
  88 }
  89
  90 boolean_t
  91 zfeature_is_supported(const char *guid)
  92 {
  93         spa_feature_t i;
  94
  95         if (zfeature_checks_disable)
  96                 return (B_TRUE);
  97
  98         for (i = 0; i < SPA_FEATURES; i++) {
  99                 zfeature_info_t *feature = &spa_feature_table[i];
 100                 if (strcmp(guid, feature->fi_guid) == 0)
 101                         return (B_TRUE);
 102         }
 103
 104         return (B_FALSE);
 105 }
 106
 107 int
 108 zfeature_lookup_name(const char *name, spa_feature_t *res)
 109 {
 110         spa_feature_t i;
 111
 112         for (i = 0; i < SPA_FEATURES; i++) {
 113                 zfeature_info_t *feature = &spa_feature_table[i];
 114                 if (strcmp(name, feature->fi_uname) == 0) {
 115                         if (res != NULL)
 116                                 *res = i;
 117                         return (0);
 118                 }
 119         }
 120
 121         return (ENOENT);
 122 }
 123
 124 boolean_t
 125 zfeature_depends_on(spa_feature_t fid, spa_feature_t check) {
 126         zfeature_info_t *feature = &spa_feature_table[fid];
 127         int i;
 128
 129         for (i = 0; feature->fi_depends[i] != SPA_FEATURE_NONE; i++) {
 130                 if (feature->fi_depends[i] == check)
 131                         return (B_TRUE);
 132         }
 133         return (B_FALSE);
 134 }
 135
 136 static void
 137 zfeature_register(spa_feature_t fid, const char *guid, const char *name,
 138     const char *desc, boolean_t readonly, boolean_t mos,
 139     boolean_t activate_on_enable, const spa_feature_t *deps)
 140 {
 141         zfeature_info_t *feature = &spa_feature_table[fid];
 142         static spa_feature_t nodeps[] = { SPA_FEATURE_NONE };
 143
 144         ASSERT(name != NULL);
 145         ASSERT(desc != NULL);
 146         ASSERT(!readonly || !mos);
 147         ASSERT3U(fid, <, SPA_FEATURES);
 148         ASSERT(zfeature_is_valid_guid(guid));
 149
 150         if (deps == NULL)
 151                 deps = nodeps;
 152
 153         feature->fi_feature = fid;
 154         feature->fi_guid = guid;
 155         feature->fi_uname = name;
 156         feature->fi_desc = desc;
 157         feature->fi_can_readonly = readonly;
 158         feature->fi_mos = mos;
 159         feature->fi_activate_on_enable = activate_on_enable;
 160         feature->fi_depends = deps;
 161 }
 162
 163 void
 164 zpool_feature_init(void)
 165 {
 166         zfeature_register(SPA_FEATURE_ASYNC_DESTROY,
 167             "com.delphix:async_destroy", "async_destroy",
 168             "Destroy filesystems asynchronously.", B_TRUE, B_FALSE,
 169             B_FALSE, NULL);
 170
 171         zfeature_register(SPA_FEATURE_EMPTY_BPOBJ,
 172             "com.delphix:empty_bpobj", "empty_bpobj",
 173             "Snapshots use less space.", B_TRUE, B_FALSE,
 174             B_FALSE, NULL);
 175
 176         zfeature_register(SPA_FEATURE_LZ4_COMPRESS,
 177             "org.illumos:lz4_compress", "lz4_compress",
 178             "LZ4 compression algorithm support.", B_FALSE, B_FALSE,
 179             B_TRUE, 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         {
 192         static const spa_feature_t hole_birth_deps[] = {
 193                 SPA_FEATURE_ENABLED_TXG,
 194                 SPA_FEATURE_NONE
 195         };
 196         zfeature_register(SPA_FEATURE_HOLE_BIRTH,
 197             "com.delphix:hole_birth", "hole_birth",
 198             "Retain hole birth txg for more precise zfs send",
 199             B_FALSE, B_TRUE, B_TRUE, hole_birth_deps);
 200         }
 201
 202         zfeature_register(SPA_FEATURE_EXTENSIBLE_DATASET,
 203             "com.delphix:extensible_dataset", "extensible_dataset",
 204             "Enhanced dataset functionality, used by other features.",
 205             B_FALSE, B_FALSE, B_FALSE, NULL);
 206
 207         {
 208         static const spa_feature_t bookmarks_deps[] = {
 209                 SPA_FEATURE_EXTENSIBLE_DATASET,
 210                 SPA_FEATURE_NONE
 211         };
 212
 213         zfeature_register(SPA_FEATURE_BOOKMARKS,
 214             "com.delphix:bookmarks", "bookmarks",
 215             "\"zfs bookmark\" command",
 216             B_TRUE, B_FALSE, B_FALSE, bookmarks_deps);
 217         }
 218
 219         {
 220         static const spa_feature_t filesystem_limits_deps[] = {
 221             SPA_FEATURE_EXTENSIBLE_DATASET,
 222             SPA_FEATURE_NONE
 223         };
 224         zfeature_register(SPA_FEATURE_FS_SS_LIMIT,
 225             "com.joyent:filesystem_limits", "filesystem_limits",
 226             "Filesystem and snapshot limits.", B_TRUE, B_FALSE, B_FALSE,
 227             filesystem_limits_deps);
 228         }
 229
 230         zfeature_register(SPA_FEATURE_EMBEDDED_DATA,
 231             "com.delphix:embedded_data", "embedded_data",
 232             "Blocks which compress very well use even less space.",
 233             B_FALSE, B_TRUE, B_TRUE, NULL);
 234
 235         {
 236         static const spa_feature_t large_blocks_deps[] = {
 237                 SPA_FEATURE_EXTENSIBLE_DATASET,
 238                 SPA_FEATURE_NONE
 239         };
 240         zfeature_register(SPA_FEATURE_LARGE_BLOCKS,
 241             "org.open-zfs:large_blocks", "large_blocks",
 242             "Support for blocks larger than 128KB.", B_FALSE, B_FALSE, B_FALSE,
 243             large_blocks_deps);
 244         }
 245 }