cmd/zhack/zhack.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) 2011, 2015 by Delphix. All rights reserved.
  24  * Copyright (c) 2013 Steven Hartland. All rights reserved.
  25  */
  26
  27 /*
  28  * zhack is a debugging tool that can write changes to ZFS pool using libzpool
  29  * for testing purposes. Altering pools with zhack is unsupported and may
  30  * result in corrupted pools.
  31  */
  32
  33 #include <stdio.h>
  34 #include <stdlib.h>
  35 #include <ctype.h>
  36 #include <sys/zfs_context.h>
  37 #include <sys/spa.h>
  38 #include <sys/spa_impl.h>
  39 #include <sys/dmu.h>
  40 #include <sys/zap.h>
  41 #include <sys/zfs_znode.h>
  42 #include <sys/dsl_synctask.h>
  43 #include <sys/vdev.h>
  44 #include <sys/fs/zfs.h>
  45 #include <sys/dmu_objset.h>
  46 #include <sys/dsl_pool.h>
  47 #include <sys/zio_checksum.h>
  48 #include <sys/zio_compress.h>
  49 #include <sys/zfeature.h>
  50 #include <sys/dmu_tx.h>
  51 #include <libzutil.h>
  52
  53 extern boolean_t zfeature_checks_disable;
  54
  55 const char cmdname[] = "zhack";
  56 static importargs_t g_importargs;
  57 static char *g_pool;
  58 static boolean_t g_readonly;
  59
  60 static void
  61 usage(void)
  62 {
  63         (void) fprintf(stderr,
  64             "Usage: %s [-c cachefile] [-d dir] <subcommand> <args> ...\n"
  65             "where <subcommand> <args> is one of the following:\n"
  66             "\n", cmdname);
  67
  68         (void) fprintf(stderr,
  69             "    feature stat <pool>\n"
  70             "        print information about enabled features\n"
  71             "    feature enable [-r] [-d desc] <pool> <feature>\n"
  72             "        add a new enabled feature to the pool\n"
  73             "        -d <desc> sets the feature's description\n"
  74             "        -r set read-only compatible flag for feature\n"
  75             "    feature ref [-md] <pool> <feature>\n"
  76             "        change the refcount on the given feature\n"
  77             "        -d decrease instead of increase the refcount\n"
  78             "        -m add the feature to the label if increasing refcount\n"
  79             "\n"
  80             "    <feature> : should be a feature guid\n");
  81         exit(1);
  82 }
  83
  84
  85 static void
  86 fatal(spa_t *spa, void *tag, const char *fmt, ...)
  87 {
  88         va_list ap;
  89
  90         if (spa != NULL) {
  91                 spa_close(spa, tag);
  92                 (void) spa_export(g_pool, NULL, B_TRUE, B_FALSE);
  93         }
  94
  95         va_start(ap, fmt);
  96         (void) fprintf(stderr, "%s: ", cmdname);
  97         (void) vfprintf(stderr, fmt, ap);
  98         va_end(ap);
  99         (void) fprintf(stderr, "\n");
 100
 101         exit(1);
 102 }
 103
 104 /* ARGSUSED */
 105 static int
 106 space_delta_cb(dmu_object_type_t bonustype, const void *data,
 107     zfs_file_info_t *zoi)
 108 {
 109         /*
 110          * Is it a valid type of object to track?
 111          */
 112         if (bonustype != DMU_OT_ZNODE && bonustype != DMU_OT_SA)
 113                 return (ENOENT);
 114         (void) fprintf(stderr, "modifying object that needs user accounting");
 115         abort();
 116         /* NOTREACHED */
 117 }
 118
 119 /*
 120  * Target is the dataset whose pool we want to open.
 121  */
 122 static void
 123 zhack_import(char *target, boolean_t readonly)
 124 {
 125         nvlist_t *config;
 126         nvlist_t *props;
 127         int error;
 128
 129         kernel_init(readonly ? SPA_MODE_READ :
 130             (SPA_MODE_READ | SPA_MODE_WRITE));
 131
 132         dmu_objset_register_type(DMU_OST_ZFS, space_delta_cb);
 133
 134         g_readonly = readonly;
 135         g_importargs.can_be_active = readonly;
 136         g_pool = strdup(target);
 137
 138         error = zpool_find_config(NULL, target, &config, &g_importargs,
 139             &libzpool_config_ops);
 140         if (error)
 141                 fatal(NULL, FTAG, "cannot import '%s'", target);
 142
 143         props = NULL;
 144         if (readonly) {
 145                 VERIFY(nvlist_alloc(&props, NV_UNIQUE_NAME, 0) == 0);
 146                 VERIFY(nvlist_add_uint64(props,
 147                     zpool_prop_to_name(ZPOOL_PROP_READONLY), 1) == 0);
 148         }
 149
 150         zfeature_checks_disable = B_TRUE;
 151         error = spa_import(target, config, props,
 152             (readonly ?  ZFS_IMPORT_SKIP_MMP : ZFS_IMPORT_NORMAL));
 153         zfeature_checks_disable = B_FALSE;
 154         if (error == EEXIST)
 155                 error = 0;
 156
 157         if (error)
 158                 fatal(NULL, FTAG, "can't import '%s': %s", target,
 159                     strerror(error));
 160 }
 161
 162 static void
 163 zhack_spa_open(char *target, boolean_t readonly, void *tag, spa_t **spa)
 164 {
 165         int err;
 166
 167         zhack_import(target, readonly);
 168
 169         zfeature_checks_disable = B_TRUE;
 170         err = spa_open(target, spa, tag);
 171         zfeature_checks_disable = B_FALSE;
 172
 173         if (err != 0)
 174                 fatal(*spa, FTAG, "cannot open '%s': %s", target,
 175                     strerror(err));
 176         if (spa_version(*spa) < SPA_VERSION_FEATURES) {
 177                 fatal(*spa, FTAG, "'%s' has version %d, features not enabled",
 178                     target, (int)spa_version(*spa));
 179         }
 180 }
 181
 182 static void
 183 dump_obj(objset_t *os, uint64_t obj, const char *name)
 184 {
 185         zap_cursor_t zc;
 186         zap_attribute_t za;
 187
 188         (void) printf("%s_obj:\n", name);
 189
 190         for (zap_cursor_init(&zc, os, obj);
 191             zap_cursor_retrieve(&zc, &za) == 0;
 192             zap_cursor_advance(&zc)) {
 193                 if (za.za_integer_length == 8) {
 194                         ASSERT(za.za_num_integers == 1);
 195                         (void) printf("\t%s = %llu\n",
 196                             za.za_name, (u_longlong_t)za.za_first_integer);
 197                 } else {
 198                         ASSERT(za.za_integer_length == 1);
 199                         char val[1024];
 200                         VERIFY(zap_lookup(os, obj, za.za_name,
 201                             1, sizeof (val), val) == 0);
 202                         (void) printf("\t%s = %s\n", za.za_name, val);
 203                 }
 204         }
 205         zap_cursor_fini(&zc);
 206 }
 207
 208 static void
 209 dump_mos(spa_t *spa)
 210 {
 211         nvlist_t *nv = spa->spa_label_features;
 212         nvpair_t *pair;
 213
 214         (void) printf("label config:\n");
 215         for (pair = nvlist_next_nvpair(nv, NULL);
 216             pair != NULL;
 217             pair = nvlist_next_nvpair(nv, pair)) {
 218                 (void) printf("\t%s\n", nvpair_name(pair));
 219         }
 220 }
 221
 222 static void
 223 zhack_do_feature_stat(int argc, char **argv)
 224 {
 225         spa_t *spa;
 226         objset_t *os;
 227         char *target;
 228
 229         argc--;
 230         argv++;
 231
 232         if (argc < 1) {
 233                 (void) fprintf(stderr, "error: missing pool name\n");
 234                 usage();
 235         }
 236         target = argv[0];
 237
 238         zhack_spa_open(target, B_TRUE, FTAG, &spa);
 239         os = spa->spa_meta_objset;
 240
 241         dump_obj(os, spa->spa_feat_for_read_obj, "for_read");
 242         dump_obj(os, spa->spa_feat_for_write_obj, "for_write");
 243         dump_obj(os, spa->spa_feat_desc_obj, "descriptions");
 244         if (spa_feature_is_active(spa, SPA_FEATURE_ENABLED_TXG)) {
 245                 dump_obj(os, spa->spa_feat_enabled_txg_obj, "enabled_txg");
 246         }
 247         dump_mos(spa);
 248
 249         spa_close(spa, FTAG);
 250 }
 251
 252 static void
 253 zhack_feature_enable_sync(void *arg, dmu_tx_t *tx)
 254 {
 255         spa_t *spa = dmu_tx_pool(tx)->dp_spa;
 256         zfeature_info_t *feature = arg;
 257
 258         feature_enable_sync(spa, feature, tx);
 259
 260         spa_history_log_internal(spa, "zhack enable feature", tx,
 261             "name=%s flags=%u",
 262             feature->fi_guid, feature->fi_flags);
 263 }
 264
 265 static void
 266 zhack_do_feature_enable(int argc, char **argv)
 267 {
 268         int c;
 269         char *desc, *target;
 270         spa_t *spa;
 271         objset_t *mos;
 272         zfeature_info_t feature;
 273         spa_feature_t nodeps[] = { SPA_FEATURE_NONE };
 274
 275         /*
 276          * Features are not added to the pool's label until their refcounts
 277          * are incremented, so fi_mos can just be left as false for now.
 278          */
 279         desc = NULL;
 280         feature.fi_uname = "zhack";
 281         feature.fi_flags = 0;
 282         feature.fi_depends = nodeps;
 283         feature.fi_feature = SPA_FEATURE_NONE;
 284
 285         optind = 1;
 286         while ((c = getopt(argc, argv, "+rd:")) != -1) {
 287                 switch (c) {
 288                 case 'r':
 289                         feature.fi_flags |= ZFEATURE_FLAG_READONLY_COMPAT;
 290                         break;
 291                 case 'd':
 292                         desc = strdup(optarg);
 293                         break;
 294                 default:
 295                         usage();
 296                         break;
 297                 }
 298         }
 299
 300         if (desc == NULL)
 301                 desc = strdup("zhack injected");
 302         feature.fi_desc = desc;
 303
 304         argc -= optind;
 305         argv += optind;
 306
 307         if (argc < 2) {
 308                 (void) fprintf(stderr, "error: missing feature or pool name\n");
 309                 usage();
 310         }
 311         target = argv[0];
 312         feature.fi_guid = argv[1];
 313
 314         if (!zfeature_is_valid_guid(feature.fi_guid))
 315                 fatal(NULL, FTAG, "invalid feature guid: %s", feature.fi_guid);
 316
 317         zhack_spa_open(target, B_FALSE, FTAG, &spa);
 318         mos = spa->spa_meta_objset;
 319
 320         if (zfeature_is_supported(feature.fi_guid))
 321                 fatal(spa, FTAG, "'%s' is a real feature, will not enable");
 322         if (0 == zap_contains(mos, spa->spa_feat_desc_obj, feature.fi_guid))
 323                 fatal(spa, FTAG, "feature already enabled: %s",
 324                     feature.fi_guid);
 325
 326         VERIFY0(dsl_sync_task(spa_name(spa), NULL,
 327             zhack_feature_enable_sync, &feature, 5, ZFS_SPACE_CHECK_NORMAL));
 328
 329         spa_close(spa, FTAG);
 330
 331         free(desc);
 332 }
 333
 334 static void
 335 feature_incr_sync(void *arg, dmu_tx_t *tx)
 336 {
 337         spa_t *spa = dmu_tx_pool(tx)->dp_spa;
 338         zfeature_info_t *feature = arg;
 339         uint64_t refcount;
 340
 341         VERIFY0(feature_get_refcount_from_disk(spa, feature, &refcount));
 342         feature_sync(spa, feature, refcount + 1, tx);
 343         spa_history_log_internal(spa, "zhack feature incr", tx,
 344             "name=%s", feature->fi_guid);
 345 }
 346
 347 static void
 348 feature_decr_sync(void *arg, dmu_tx_t *tx)
 349 {
 350         spa_t *spa = dmu_tx_pool(tx)->dp_spa;
 351         zfeature_info_t *feature = arg;
 352         uint64_t refcount;
 353
 354         VERIFY0(feature_get_refcount_from_disk(spa, feature, &refcount));
 355         feature_sync(spa, feature, refcount - 1, tx);
 356         spa_history_log_internal(spa, "zhack feature decr", tx,
 357             "name=%s", feature->fi_guid);
 358 }
 359
 360 static void
 361 zhack_do_feature_ref(int argc, char **argv)
 362 {
 363         int c;
 364         char *target;
 365         boolean_t decr = B_FALSE;
 366         spa_t *spa;
 367         objset_t *mos;
 368         zfeature_info_t feature;
 369         spa_feature_t nodeps[] = { SPA_FEATURE_NONE };
 370
 371         /*
 372          * fi_desc does not matter here because it was written to disk
 373          * when the feature was enabled, but we need to properly set the
 374          * feature for read or write based on the information we read off
 375          * disk later.
 376          */
 377         feature.fi_uname = "zhack";
 378         feature.fi_flags = 0;
 379         feature.fi_desc = NULL;
 380         feature.fi_depends = nodeps;
 381         feature.fi_feature = SPA_FEATURE_NONE;
 382
 383         optind = 1;
 384         while ((c = getopt(argc, argv, "+md")) != -1) {
 385                 switch (c) {
 386                 case 'm':
 387                         feature.fi_flags |= ZFEATURE_FLAG_MOS;
 388                         break;
 389                 case 'd':
 390                         decr = B_TRUE;
 391                         break;
 392                 default:
 393                         usage();
 394                         break;
 395                 }
 396         }
 397         argc -= optind;
 398         argv += optind;
 399
 400         if (argc < 2) {
 401                 (void) fprintf(stderr, "error: missing feature or pool name\n");
 402                 usage();
 403         }
 404         target = argv[0];
 405         feature.fi_guid = argv[1];
 406
 407         if (!zfeature_is_valid_guid(feature.fi_guid))
 408                 fatal(NULL, FTAG, "invalid feature guid: %s", feature.fi_guid);
 409
 410         zhack_spa_open(target, B_FALSE, FTAG, &spa);
 411         mos = spa->spa_meta_objset;
 412
 413         if (zfeature_is_supported(feature.fi_guid)) {
 414                 fatal(spa, FTAG,
 415                     "'%s' is a real feature, will not change refcount");
 416         }
 417
 418         if (0 == zap_contains(mos, spa->spa_feat_for_read_obj,
 419             feature.fi_guid)) {
 420                 feature.fi_flags &= ~ZFEATURE_FLAG_READONLY_COMPAT;
 421         } else if (0 == zap_contains(mos, spa->spa_feat_for_write_obj,
 422             feature.fi_guid)) {
 423                 feature.fi_flags |= ZFEATURE_FLAG_READONLY_COMPAT;
 424         } else {
 425                 fatal(spa, FTAG, "feature is not enabled: %s", feature.fi_guid);
 426         }
 427
 428         if (decr) {
 429                 uint64_t count;
 430                 if (feature_get_refcount_from_disk(spa, &feature,
 431                     &count) == 0 && count == 0) {
 432                         fatal(spa, FTAG, "feature refcount already 0: %s",
 433                             feature.fi_guid);
 434                 }
 435         }
 436
 437         VERIFY0(dsl_sync_task(spa_name(spa), NULL,
 438             decr ? feature_decr_sync : feature_incr_sync, &feature,
 439             5, ZFS_SPACE_CHECK_NORMAL));
 440
 441         spa_close(spa, FTAG);
 442 }
 443
 444 static int
 445 zhack_do_feature(int argc, char **argv)
 446 {
 447         char *subcommand;
 448
 449         argc--;
 450         argv++;
 451         if (argc == 0) {
 452                 (void) fprintf(stderr,
 453                     "error: no feature operation specified\n");
 454                 usage();
 455         }
 456
 457         subcommand = argv[0];
 458         if (strcmp(subcommand, "stat") == 0) {
 459                 zhack_do_feature_stat(argc, argv);
 460         } else if (strcmp(subcommand, "enable") == 0) {
 461                 zhack_do_feature_enable(argc, argv);
 462         } else if (strcmp(subcommand, "ref") == 0) {
 463                 zhack_do_feature_ref(argc, argv);
 464         } else {
 465                 (void) fprintf(stderr, "error: unknown subcommand: %s\n",
 466                     subcommand);
 467                 usage();
 468         }
 469
 470         return (0);
 471 }
 472
 473 #define MAX_NUM_PATHS 1024
 474
 475 int
 476 main(int argc, char **argv)
 477 {
 478         extern void zfs_prop_init(void);
 479
 480         char *path[MAX_NUM_PATHS];
 481         const char *subcommand;
 482         int rv = 0;
 483         int c;
 484
 485         g_importargs.path = path;
 486
 487         dprintf_setup(&argc, argv);
 488         zfs_prop_init();
 489
 490         while ((c = getopt(argc, argv, "+c:d:")) != -1) {
 491                 switch (c) {
 492                 case 'c':
 493                         g_importargs.cachefile = optarg;
 494                         break;
 495                 case 'd':
 496                         assert(g_importargs.paths < MAX_NUM_PATHS);
 497                         g_importargs.path[g_importargs.paths++] = optarg;
 498                         break;
 499                 default:
 500                         usage();
 501                         break;
 502                 }
 503         }
 504
 505         argc -= optind;
 506         argv += optind;
 507         optind = 1;
 508
 509         if (argc == 0) {
 510                 (void) fprintf(stderr, "error: no command specified\n");
 511                 usage();
 512         }
 513
 514         subcommand = argv[0];
 515
 516         if (strcmp(subcommand, "feature") == 0) {
 517                 rv = zhack_do_feature(argc, argv);
 518         } else {
 519                 (void) fprintf(stderr, "error: unknown subcommand: %s\n",
 520                     subcommand);
 521                 usage();
 522         }
 523
 524         if (!g_readonly && spa_export(g_pool, NULL, B_TRUE, B_FALSE) != 0) {
 525                 fatal(NULL, FTAG, "pool export failed; "
 526                     "changes may not be committed to disk\n");
 527         }
 528
 529         kernel_fini();
 530
 531         return (rv);
 532 }