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 <libzfs.h>
  52
  53 extern boolean_t zfeature_checks_disable;
  54
  55 const char cmdname[] = "zhack";
  56 libzfs_handle_t *g_zfs;
  57 static importargs_t g_importargs;
  58 static char *g_pool;
  59 static boolean_t g_readonly;
  60
  61 static void
  62 usage(void)
  63 {
  64         (void) fprintf(stderr,
  65             "Usage: %s [-c cachefile] [-d dir] <subcommand> <args> ...\n"
  66             "where <subcommand> <args> is one of the following:\n"
  67             "\n", cmdname);
  68
  69         (void) fprintf(stderr,
  70             "    feature stat <pool>\n"
  71             "        print information about enabled features\n"
  72             "    feature enable [-r] [-d desc] <pool> <feature>\n"
  73             "        add a new enabled feature to the pool\n"
  74             "        -d <desc> sets the feature's description\n"
  75             "        -r set read-only compatible flag for feature\n"
  76             "    feature ref [-md] <pool> <feature>\n"
  77             "        change the refcount on the given feature\n"
  78             "        -d decrease instead of increase the refcount\n"
  79             "        -m add the feature to the label if increasing refcount\n"
  80             "\n"
  81             "    <feature> : should be a feature guid\n");
  82         exit(1);
  83 }
  84
  85
  86 static void
  87 fatal(spa_t *spa, void *tag, const char *fmt, ...)
  88 {
  89         va_list ap;
  90
  91         if (spa != NULL) {
  92                 spa_close(spa, tag);
  93                 (void) spa_export(g_pool, NULL, B_TRUE, B_FALSE);
  94         }
  95
  96         va_start(ap, fmt);
  97         (void) fprintf(stderr, "%s: ", cmdname);
  98         (void) vfprintf(stderr, fmt, ap);
  99         va_end(ap);
 100         (void) fprintf(stderr, "\n");
 101
 102         exit(1);
 103 }
 104
 105 /* ARGSUSED */
 106 static int
 107 space_delta_cb(dmu_object_type_t bonustype, void *data,
 108     uint64_t *userp, uint64_t *groupp)
 109 {
 110         /*
 111          * Is it a valid type of object to track?
 112          */
 113         if (bonustype != DMU_OT_ZNODE && bonustype != DMU_OT_SA)
 114                 return (ENOENT);
 115         (void) fprintf(stderr, "modifying object that needs user accounting");
 116         abort();
 117         /* NOTREACHED */
 118 }
 119
 120 /*
 121  * Target is the dataset whose pool we want to open.
 122  */
 123 static void
 124 zhack_import(char *target, boolean_t readonly)
 125 {
 126         nvlist_t *config;
 127         nvlist_t *props;
 128         int error;
 129
 130         kernel_init(readonly ? FREAD : (FREAD | FWRITE));
 131         g_zfs = libzfs_init();
 132         ASSERT(g_zfs != NULL);
 133
 134         dmu_objset_register_type(DMU_OST_ZFS, space_delta_cb);
 135
 136         g_readonly = readonly;
 137         g_importargs.unique = B_TRUE;
 138         g_importargs.can_be_active = readonly;
 139         g_pool = strdup(target);
 140
 141         error = zpool_tryimport(g_zfs, target, &config, &g_importargs);
 142         if (error)
 143                 fatal(NULL, FTAG, "cannot import '%s': %s", target,
 144                     libzfs_error_description(g_zfs));
 145
 146         props = NULL;
 147         if (readonly) {
 148                 VERIFY(nvlist_alloc(&props, NV_UNIQUE_NAME, 0) == 0);
 149                 VERIFY(nvlist_add_uint64(props,
 150                     zpool_prop_to_name(ZPOOL_PROP_READONLY), 1) == 0);
 151         }
 152
 153         zfeature_checks_disable = B_TRUE;
 154         error = spa_import(target, config, props, ZFS_IMPORT_NORMAL);
 155         zfeature_checks_disable = B_FALSE;
 156         if (error == EEXIST)
 157                 error = 0;
 158
 159         if (error)
 160                 fatal(NULL, FTAG, "can't import '%s': %s", target,
 161                     strerror(error));
 162 }
 163
 164 static void
 165 zhack_spa_open(char *target, boolean_t readonly, void *tag, spa_t **spa)
 166 {
 167         int err;
 168
 169         zhack_import(target, readonly);
 170
 171         zfeature_checks_disable = B_TRUE;
 172         err = spa_open(target, spa, tag);
 173         zfeature_checks_disable = B_FALSE;
 174
 175         if (err != 0)
 176                 fatal(*spa, FTAG, "cannot open '%s': %s", target,
 177                     strerror(err));
 178         if (spa_version(*spa) < SPA_VERSION_FEATURES) {
 179                 fatal(*spa, FTAG, "'%s' has version %d, features not enabled",
 180                     target, (int)spa_version(*spa));
 181         }
 182 }
 183
 184 static void
 185 dump_obj(objset_t *os, uint64_t obj, const char *name)
 186 {
 187         zap_cursor_t zc;
 188         zap_attribute_t za;
 189
 190         (void) printf("%s_obj:\n", name);
 191
 192         for (zap_cursor_init(&zc, os, obj);
 193             zap_cursor_retrieve(&zc, &za) == 0;
 194             zap_cursor_advance(&zc)) {
 195                 if (za.za_integer_length == 8) {
 196                         ASSERT(za.za_num_integers == 1);
 197                         (void) printf("\t%s = %llu\n",
 198                             za.za_name, (u_longlong_t)za.za_first_integer);
 199                 } else {
 200                         ASSERT(za.za_integer_length == 1);
 201                         char val[1024];
 202                         VERIFY(zap_lookup(os, obj, za.za_name,
 203                             1, sizeof (val), val) == 0);
 204                         (void) printf("\t%s = %s\n", za.za_name, val);
 205                 }
 206         }
 207         zap_cursor_fini(&zc);
 208 }
 209
 210 static void
 211 dump_mos(spa_t *spa)
 212 {
 213         nvlist_t *nv = spa->spa_label_features;
 214         nvpair_t *pair;
 215
 216         (void) printf("label config:\n");
 217         for (pair = nvlist_next_nvpair(nv, NULL);
 218             pair != NULL;
 219             pair = nvlist_next_nvpair(nv, pair)) {
 220                 (void) printf("\t%s\n", nvpair_name(pair));
 221         }
 222 }
 223
 224 static void
 225 zhack_do_feature_stat(int argc, char **argv)
 226 {
 227         spa_t *spa;
 228         objset_t *os;
 229         char *target;
 230
 231         argc--;
 232         argv++;
 233
 234         if (argc < 1) {
 235                 (void) fprintf(stderr, "error: missing pool name\n");
 236                 usage();
 237         }
 238         target = argv[0];
 239
 240         zhack_spa_open(target, B_TRUE, FTAG, &spa);
 241         os = spa->spa_meta_objset;
 242
 243         dump_obj(os, spa->spa_feat_for_read_obj, "for_read");
 244         dump_obj(os, spa->spa_feat_for_write_obj, "for_write");
 245         dump_obj(os, spa->spa_feat_desc_obj, "descriptions");
 246         if (spa_feature_is_active(spa, SPA_FEATURE_ENABLED_TXG)) {
 247                 dump_obj(os, spa->spa_feat_enabled_txg_obj, "enabled_txg");
 248         }
 249         dump_mos(spa);
 250
 251         spa_close(spa, FTAG);
 252 }
 253
 254 static void
 255 zhack_feature_enable_sync(void *arg, dmu_tx_t *tx)
 256 {
 257         spa_t *spa = dmu_tx_pool(tx)->dp_spa;
 258         zfeature_info_t *feature = arg;
 259
 260         feature_enable_sync(spa, feature, tx);
 261
 262         spa_history_log_internal(spa, "zhack enable feature", tx,
 263             "name=%s flags=%u",
 264             feature->fi_guid, feature->fi_flags);
 265 }
 266
 267 static void
 268 zhack_do_feature_enable(int argc, char **argv)
 269 {
 270         char c;
 271         char *desc, *target;
 272         spa_t *spa;
 273         objset_t *mos;
 274         zfeature_info_t feature;
 275         spa_feature_t nodeps[] = { SPA_FEATURE_NONE };
 276
 277         /*
 278          * Features are not added to the pool's label until their refcounts
 279          * are incremented, so fi_mos can just be left as false for now.
 280          */
 281         desc = NULL;
 282         feature.fi_uname = "zhack";
 283         feature.fi_flags = 0;
 284         feature.fi_depends = nodeps;
 285         feature.fi_feature = SPA_FEATURE_NONE;
 286
 287         optind = 1;
 288         while ((c = getopt(argc, argv, "+rd:")) != -1) {
 289                 switch (c) {
 290                 case 'r':
 291                         feature.fi_flags |= ZFEATURE_FLAG_READONLY_COMPAT;
 292                         break;
 293                 case 'd':
 294                         desc = strdup(optarg);
 295                         break;
 296                 default:
 297                         usage();
 298                         break;
 299                 }
 300         }
 301
 302         if (desc == NULL)
 303                 desc = strdup("zhack injected");
 304         feature.fi_desc = desc;
 305
 306         argc -= optind;
 307         argv += optind;
 308
 309         if (argc < 2) {
 310                 (void) fprintf(stderr, "error: missing feature or pool name\n");
 311                 usage();
 312         }
 313         target = argv[0];
 314         feature.fi_guid = argv[1];
 315
 316         if (!zfeature_is_valid_guid(feature.fi_guid))
 317                 fatal(NULL, FTAG, "invalid feature guid: %s", feature.fi_guid);
 318
 319         zhack_spa_open(target, B_FALSE, FTAG, &spa);
 320         mos = spa->spa_meta_objset;
 321
 322         if (zfeature_is_supported(feature.fi_guid))
 323                 fatal(spa, FTAG, "'%s' is a real feature, will not enable");
 324         if (0 == zap_contains(mos, spa->spa_feat_desc_obj, feature.fi_guid))
 325                 fatal(spa, FTAG, "feature already enabled: %s",
 326                     feature.fi_guid);
 327
 328         VERIFY0(dsl_sync_task(spa_name(spa), NULL,
 329             zhack_feature_enable_sync, &feature, 5, ZFS_SPACE_CHECK_NORMAL));
 330
 331         spa_close(spa, FTAG);
 332
 333         free(desc);
 334 }
 335
 336 static void
 337 feature_incr_sync(void *arg, dmu_tx_t *tx)
 338 {
 339         spa_t *spa = dmu_tx_pool(tx)->dp_spa;
 340         zfeature_info_t *feature = arg;
 341         uint64_t refcount;
 342
 343         VERIFY0(feature_get_refcount_from_disk(spa, feature, &refcount));
 344         feature_sync(spa, feature, refcount + 1, tx);
 345         spa_history_log_internal(spa, "zhack feature incr", tx,
 346             "name=%s", feature->fi_guid);
 347 }
 348
 349 static void
 350 feature_decr_sync(void *arg, dmu_tx_t *tx)
 351 {
 352         spa_t *spa = dmu_tx_pool(tx)->dp_spa;
 353         zfeature_info_t *feature = arg;
 354         uint64_t refcount;
 355
 356         VERIFY0(feature_get_refcount_from_disk(spa, feature, &refcount));
 357         feature_sync(spa, feature, refcount - 1, tx);
 358         spa_history_log_internal(spa, "zhack feature decr", tx,
 359             "name=%s", feature->fi_guid);
 360 }
 361
 362 static void
 363 zhack_do_feature_ref(int argc, char **argv)
 364 {
 365         char c;
 366         char *target;
 367         boolean_t decr = B_FALSE;
 368         spa_t *spa;
 369         objset_t *mos;
 370         zfeature_info_t feature;
 371         spa_feature_t nodeps[] = { SPA_FEATURE_NONE };
 372
 373         /*
 374          * fi_desc does not matter here because it was written to disk
 375          * when the feature was enabled, but we need to properly set the
 376          * feature for read or write based on the information we read off
 377          * disk later.
 378          */
 379         feature.fi_uname = "zhack";
 380         feature.fi_flags = 0;
 381         feature.fi_desc = NULL;
 382         feature.fi_depends = nodeps;
 383         feature.fi_feature = SPA_FEATURE_NONE;
 384
 385         optind = 1;
 386         while ((c = getopt(argc, argv, "+md")) != -1) {
 387                 switch (c) {
 388                 case 'm':
 389                         feature.fi_flags |= ZFEATURE_FLAG_MOS;
 390                         break;
 391                 case 'd':
 392                         decr = B_TRUE;
 393                         break;
 394                 default:
 395                         usage();
 396                         break;
 397                 }
 398         }
 399         argc -= optind;
 400         argv += optind;
 401
 402         if (argc < 2) {
 403                 (void) fprintf(stderr, "error: missing feature or pool name\n");
 404                 usage();
 405         }
 406         target = argv[0];
 407         feature.fi_guid = argv[1];
 408
 409         if (!zfeature_is_valid_guid(feature.fi_guid))
 410                 fatal(NULL, FTAG, "invalid feature guid: %s", feature.fi_guid);
 411
 412         zhack_spa_open(target, B_FALSE, FTAG, &spa);
 413         mos = spa->spa_meta_objset;
 414
 415         if (zfeature_is_supported(feature.fi_guid)) {
 416                 fatal(spa, FTAG,
 417                     "'%s' is a real feature, will not change refcount");
 418         }
 419
 420         if (0 == zap_contains(mos, spa->spa_feat_for_read_obj,
 421             feature.fi_guid)) {
 422                 feature.fi_flags &= ~ZFEATURE_FLAG_READONLY_COMPAT;
 423         } else if (0 == zap_contains(mos, spa->spa_feat_for_write_obj,
 424             feature.fi_guid)) {
 425                 feature.fi_flags |= ZFEATURE_FLAG_READONLY_COMPAT;
 426         } else {
 427                 fatal(spa, FTAG, "feature is not enabled: %s", feature.fi_guid);
 428         }
 429
 430         if (decr) {
 431                 uint64_t count;
 432                 if (feature_get_refcount_from_disk(spa, &feature,
 433                     &count) == 0 && count == 0) {
 434                         fatal(spa, FTAG, "feature refcount already 0: %s",
 435                             feature.fi_guid);
 436                 }
 437         }
 438
 439         VERIFY0(dsl_sync_task(spa_name(spa), NULL,
 440             decr ? feature_decr_sync : feature_incr_sync, &feature,
 441             5, ZFS_SPACE_CHECK_NORMAL));
 442
 443         spa_close(spa, FTAG);
 444 }
 445
 446 static int
 447 zhack_do_feature(int argc, char **argv)
 448 {
 449         char *subcommand;
 450
 451         argc--;
 452         argv++;
 453         if (argc == 0) {
 454                 (void) fprintf(stderr,
 455                     "error: no feature operation specified\n");
 456                 usage();
 457         }
 458
 459         subcommand = argv[0];
 460         if (strcmp(subcommand, "stat") == 0) {
 461                 zhack_do_feature_stat(argc, argv);
 462         } else if (strcmp(subcommand, "enable") == 0) {
 463                 zhack_do_feature_enable(argc, argv);
 464         } else if (strcmp(subcommand, "ref") == 0) {
 465                 zhack_do_feature_ref(argc, argv);
 466         } else {
 467                 (void) fprintf(stderr, "error: unknown subcommand: %s\n",
 468                     subcommand);
 469                 usage();
 470         }
 471
 472         return (0);
 473 }
 474
 475 #define MAX_NUM_PATHS 1024
 476
 477 int
 478 main(int argc, char **argv)
 479 {
 480         extern void zfs_prop_init(void);
 481
 482         char *path[MAX_NUM_PATHS];
 483         const char *subcommand;
 484         int rv = 0;
 485         char c;
 486
 487         g_importargs.path = path;
 488
 489         dprintf_setup(&argc, argv);
 490         zfs_prop_init();
 491
 492         while ((c = getopt(argc, argv, "+c:d:")) != -1) {
 493                 switch (c) {
 494                 case 'c':
 495                         g_importargs.cachefile = optarg;
 496                         break;
 497                 case 'd':
 498                         assert(g_importargs.paths < MAX_NUM_PATHS);
 499                         g_importargs.path[g_importargs.paths++] = optarg;
 500                         break;
 501                 default:
 502                         usage();
 503                         break;
 504                 }
 505         }
 506
 507         argc -= optind;
 508         argv += optind;
 509         optind = 1;
 510
 511         if (argc == 0) {
 512                 (void) fprintf(stderr, "error: no command specified\n");
 513                 usage();
 514         }
 515
 516         subcommand = argv[0];
 517
 518         if (strcmp(subcommand, "feature") == 0) {
 519                 rv = zhack_do_feature(argc, argv);
 520         } else {
 521                 (void) fprintf(stderr, "error: unknown subcommand: %s\n",
 522                     subcommand);
 523                 usage();
 524         }
 525
 526         if (!g_readonly && spa_export(g_pool, NULL, B_TRUE, B_FALSE) != 0) {
 527                 fatal(NULL, FTAG, "pool export failed; "
 528                     "changes may not be committed to disk\n");
 529         }
 530
 531         libzfs_fini(g_zfs);
 532         kernel_fini();
 533
 534         return (rv);
 535 }