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,
 155             (readonly ?  ZFS_IMPORT_SKIP_MMP : ZFS_IMPORT_NORMAL));
 156         zfeature_checks_disable = B_FALSE;
 157         if (error == EEXIST)
 158                 error = 0;
 159
 160         if (error)
 161                 fatal(NULL, FTAG, "can't import '%s': %s", target,
 162                     strerror(error));
 163 }
 164
 165 static void
 166 zhack_spa_open(char *target, boolean_t readonly, void *tag, spa_t **spa)
 167 {
 168         int err;
 169
 170         zhack_import(target, readonly);
 171
 172         zfeature_checks_disable = B_TRUE;
 173         err = spa_open(target, spa, tag);
 174         zfeature_checks_disable = B_FALSE;
 175
 176         if (err != 0)
 177                 fatal(*spa, FTAG, "cannot open '%s': %s", target,
 178                     strerror(err));
 179         if (spa_version(*spa) < SPA_VERSION_FEATURES) {
 180                 fatal(*spa, FTAG, "'%s' has version %d, features not enabled",
 181                     target, (int)spa_version(*spa));
 182         }
 183 }
 184
 185 static void
 186 dump_obj(objset_t *os, uint64_t obj, const char *name)
 187 {
 188         zap_cursor_t zc;
 189         zap_attribute_t za;
 190
 191         (void) printf("%s_obj:\n", name);
 192
 193         for (zap_cursor_init(&zc, os, obj);
 194             zap_cursor_retrieve(&zc, &za) == 0;
 195             zap_cursor_advance(&zc)) {
 196                 if (za.za_integer_length == 8) {
 197                         ASSERT(za.za_num_integers == 1);
 198                         (void) printf("\t%s = %llu\n",
 199                             za.za_name, (u_longlong_t)za.za_first_integer);
 200                 } else {
 201                         ASSERT(za.za_integer_length == 1);
 202                         char val[1024];
 203                         VERIFY(zap_lookup(os, obj, za.za_name,
 204                             1, sizeof (val), val) == 0);
 205                         (void) printf("\t%s = %s\n", za.za_name, val);
 206                 }
 207         }
 208         zap_cursor_fini(&zc);
 209 }
 210
 211 static void
 212 dump_mos(spa_t *spa)
 213 {
 214         nvlist_t *nv = spa->spa_label_features;
 215         nvpair_t *pair;
 216
 217         (void) printf("label config:\n");
 218         for (pair = nvlist_next_nvpair(nv, NULL);
 219             pair != NULL;
 220             pair = nvlist_next_nvpair(nv, pair)) {
 221                 (void) printf("\t%s\n", nvpair_name(pair));
 222         }
 223 }
 224
 225 static void
 226 zhack_do_feature_stat(int argc, char **argv)
 227 {
 228         spa_t *spa;
 229         objset_t *os;
 230         char *target;
 231
 232         argc--;
 233         argv++;
 234
 235         if (argc < 1) {
 236                 (void) fprintf(stderr, "error: missing pool name\n");
 237                 usage();
 238         }
 239         target = argv[0];
 240
 241         zhack_spa_open(target, B_TRUE, FTAG, &spa);
 242         os = spa->spa_meta_objset;
 243
 244         dump_obj(os, spa->spa_feat_for_read_obj, "for_read");
 245         dump_obj(os, spa->spa_feat_for_write_obj, "for_write");
 246         dump_obj(os, spa->spa_feat_desc_obj, "descriptions");
 247         if (spa_feature_is_active(spa, SPA_FEATURE_ENABLED_TXG)) {
 248                 dump_obj(os, spa->spa_feat_enabled_txg_obj, "enabled_txg");
 249         }
 250         dump_mos(spa);
 251
 252         spa_close(spa, FTAG);
 253 }
 254
 255 static void
 256 zhack_feature_enable_sync(void *arg, dmu_tx_t *tx)
 257 {
 258         spa_t *spa = dmu_tx_pool(tx)->dp_spa;
 259         zfeature_info_t *feature = arg;
 260
 261         feature_enable_sync(spa, feature, tx);
 262
 263         spa_history_log_internal(spa, "zhack enable feature", tx,
 264             "name=%s flags=%u",
 265             feature->fi_guid, feature->fi_flags);
 266 }
 267
 268 static void
 269 zhack_do_feature_enable(int argc, char **argv)
 270 {
 271         int c;
 272         char *desc, *target;
 273         spa_t *spa;
 274         objset_t *mos;
 275         zfeature_info_t feature;
 276         spa_feature_t nodeps[] = { SPA_FEATURE_NONE };
 277
 278         /*
 279          * Features are not added to the pool's label until their refcounts
 280          * are incremented, so fi_mos can just be left as false for now.
 281          */
 282         desc = NULL;
 283         feature.fi_uname = "zhack";
 284         feature.fi_flags = 0;
 285         feature.fi_depends = nodeps;
 286         feature.fi_feature = SPA_FEATURE_NONE;
 287
 288         optind = 1;
 289         while ((c = getopt(argc, argv, "+rd:")) != -1) {
 290                 switch (c) {
 291                 case 'r':
 292                         feature.fi_flags |= ZFEATURE_FLAG_READONLY_COMPAT;
 293                         break;
 294                 case 'd':
 295                         desc = strdup(optarg);
 296                         break;
 297                 default:
 298                         usage();
 299                         break;
 300                 }
 301         }
 302
 303         if (desc == NULL)
 304                 desc = strdup("zhack injected");
 305         feature.fi_desc = desc;
 306
 307         argc -= optind;
 308         argv += optind;
 309
 310         if (argc < 2) {
 311                 (void) fprintf(stderr, "error: missing feature or pool name\n");
 312                 usage();
 313         }
 314         target = argv[0];
 315         feature.fi_guid = argv[1];
 316
 317         if (!zfeature_is_valid_guid(feature.fi_guid))
 318                 fatal(NULL, FTAG, "invalid feature guid: %s", feature.fi_guid);
 319
 320         zhack_spa_open(target, B_FALSE, FTAG, &spa);
 321         mos = spa->spa_meta_objset;
 322
 323         if (zfeature_is_supported(feature.fi_guid))
 324                 fatal(spa, FTAG, "'%s' is a real feature, will not enable");
 325         if (0 == zap_contains(mos, spa->spa_feat_desc_obj, feature.fi_guid))
 326                 fatal(spa, FTAG, "feature already enabled: %s",
 327                     feature.fi_guid);
 328
 329         VERIFY0(dsl_sync_task(spa_name(spa), NULL,
 330             zhack_feature_enable_sync, &feature, 5, ZFS_SPACE_CHECK_NORMAL));
 331
 332         spa_close(spa, FTAG);
 333
 334         free(desc);
 335 }
 336
 337 static void
 338 feature_incr_sync(void *arg, dmu_tx_t *tx)
 339 {
 340         spa_t *spa = dmu_tx_pool(tx)->dp_spa;
 341         zfeature_info_t *feature = arg;
 342         uint64_t refcount;
 343
 344         VERIFY0(feature_get_refcount_from_disk(spa, feature, &refcount));
 345         feature_sync(spa, feature, refcount + 1, tx);
 346         spa_history_log_internal(spa, "zhack feature incr", tx,
 347             "name=%s", feature->fi_guid);
 348 }
 349
 350 static void
 351 feature_decr_sync(void *arg, dmu_tx_t *tx)
 352 {
 353         spa_t *spa = dmu_tx_pool(tx)->dp_spa;
 354         zfeature_info_t *feature = arg;
 355         uint64_t refcount;
 356
 357         VERIFY0(feature_get_refcount_from_disk(spa, feature, &refcount));
 358         feature_sync(spa, feature, refcount - 1, tx);
 359         spa_history_log_internal(spa, "zhack feature decr", tx,
 360             "name=%s", feature->fi_guid);
 361 }
 362
 363 static void
 364 zhack_do_feature_ref(int argc, char **argv)
 365 {
 366         int c;
 367         char *target;
 368         boolean_t decr = B_FALSE;
 369         spa_t *spa;
 370         objset_t *mos;
 371         zfeature_info_t feature;
 372         spa_feature_t nodeps[] = { SPA_FEATURE_NONE };
 373
 374         /*
 375          * fi_desc does not matter here because it was written to disk
 376          * when the feature was enabled, but we need to properly set the
 377          * feature for read or write based on the information we read off
 378          * disk later.
 379          */
 380         feature.fi_uname = "zhack";
 381         feature.fi_flags = 0;
 382         feature.fi_desc = NULL;
 383         feature.fi_depends = nodeps;
 384         feature.fi_feature = SPA_FEATURE_NONE;
 385
 386         optind = 1;
 387         while ((c = getopt(argc, argv, "+md")) != -1) {
 388                 switch (c) {
 389                 case 'm':
 390                         feature.fi_flags |= ZFEATURE_FLAG_MOS;
 391                         break;
 392                 case 'd':
 393                         decr = B_TRUE;
 394                         break;
 395                 default:
 396                         usage();
 397                         break;
 398                 }
 399         }
 400         argc -= optind;
 401         argv += optind;
 402
 403         if (argc < 2) {
 404                 (void) fprintf(stderr, "error: missing feature or pool name\n");
 405                 usage();
 406         }
 407         target = argv[0];
 408         feature.fi_guid = argv[1];
 409
 410         if (!zfeature_is_valid_guid(feature.fi_guid))
 411                 fatal(NULL, FTAG, "invalid feature guid: %s", feature.fi_guid);
 412
 413         zhack_spa_open(target, B_FALSE, FTAG, &spa);
 414         mos = spa->spa_meta_objset;
 415
 416         if (zfeature_is_supported(feature.fi_guid)) {
 417                 fatal(spa, FTAG,
 418                     "'%s' is a real feature, will not change refcount");
 419         }
 420
 421         if (0 == zap_contains(mos, spa->spa_feat_for_read_obj,
 422             feature.fi_guid)) {
 423                 feature.fi_flags &= ~ZFEATURE_FLAG_READONLY_COMPAT;
 424         } else if (0 == zap_contains(mos, spa->spa_feat_for_write_obj,
 425             feature.fi_guid)) {
 426                 feature.fi_flags |= ZFEATURE_FLAG_READONLY_COMPAT;
 427         } else {
 428                 fatal(spa, FTAG, "feature is not enabled: %s", feature.fi_guid);
 429         }
 430
 431         if (decr) {
 432                 uint64_t count;
 433                 if (feature_get_refcount_from_disk(spa, &feature,
 434                     &count) == 0 && count == 0) {
 435                         fatal(spa, FTAG, "feature refcount already 0: %s",
 436                             feature.fi_guid);
 437                 }
 438         }
 439
 440         VERIFY0(dsl_sync_task(spa_name(spa), NULL,
 441             decr ? feature_decr_sync : feature_incr_sync, &feature,
 442             5, ZFS_SPACE_CHECK_NORMAL));
 443
 444         spa_close(spa, FTAG);
 445 }
 446
 447 static int
 448 zhack_do_feature(int argc, char **argv)
 449 {
 450         char *subcommand;
 451
 452         argc--;
 453         argv++;
 454         if (argc == 0) {
 455                 (void) fprintf(stderr,
 456                     "error: no feature operation specified\n");
 457                 usage();
 458         }
 459
 460         subcommand = argv[0];
 461         if (strcmp(subcommand, "stat") == 0) {
 462                 zhack_do_feature_stat(argc, argv);
 463         } else if (strcmp(subcommand, "enable") == 0) {
 464                 zhack_do_feature_enable(argc, argv);
 465         } else if (strcmp(subcommand, "ref") == 0) {
 466                 zhack_do_feature_ref(argc, argv);
 467         } else {
 468                 (void) fprintf(stderr, "error: unknown subcommand: %s\n",
 469                     subcommand);
 470                 usage();
 471         }
 472
 473         return (0);
 474 }
 475
 476 #define MAX_NUM_PATHS 1024
 477
 478 int
 479 main(int argc, char **argv)
 480 {
 481         extern void zfs_prop_init(void);
 482
 483         char *path[MAX_NUM_PATHS];
 484         const char *subcommand;
 485         int rv = 0;
 486         int c;
 487
 488         g_importargs.path = path;
 489
 490         dprintf_setup(&argc, argv);
 491         zfs_prop_init();
 492
 493         while ((c = getopt(argc, argv, "+c:d:")) != -1) {
 494                 switch (c) {
 495                 case 'c':
 496                         g_importargs.cachefile = optarg;
 497                         break;
 498                 case 'd':
 499                         assert(g_importargs.paths < MAX_NUM_PATHS);
 500                         g_importargs.path[g_importargs.paths++] = optarg;
 501                         break;
 502                 default:
 503                         usage();
 504                         break;
 505                 }
 506         }
 507
 508         argc -= optind;
 509         argv += optind;
 510         optind = 1;
 511
 512         if (argc == 0) {
 513                 (void) fprintf(stderr, "error: no command specified\n");
 514                 usage();
 515         }
 516
 517         subcommand = argv[0];
 518
 519         if (strcmp(subcommand, "feature") == 0) {
 520                 rv = zhack_do_feature(argc, argv);
 521         } else {
 522                 (void) fprintf(stderr, "error: unknown subcommand: %s\n",
 523                     subcommand);
 524                 usage();
 525         }
 526
 527         if (!g_readonly && spa_export(g_pool, NULL, B_TRUE, B_FALSE) != 0) {
 528                 fatal(NULL, FTAG, "pool export failed; "
 529                     "changes may not be committed to disk\n");
 530         }
 531
 532         libzfs_fini(g_zfs);
 533         kernel_fini();
 534
 535         return (rv);
 536 }