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