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 <zfeature_common.h>
  52 #include <libzutil.h>
  53
  54 const char cmdname[] = "zhack";
  55 static importargs_t g_importargs;
  56 static char *g_pool;
  57 static boolean_t g_readonly;
  58
  59 static __attribute__((noreturn)) void
  60 usage(void)
  61 {
  62         (void) fprintf(stderr,
  63             "Usage: %s [-c cachefile] [-d dir] <subcommand> <args> ...\n"
  64             "where <subcommand> <args> is one of the following:\n"
  65             "\n", cmdname);
  66
  67         (void) fprintf(stderr,
  68             "    feature stat <pool>\n"
  69             "        print information about enabled features\n"
  70             "    feature enable [-r] [-d desc] <pool> <feature>\n"
  71             "        add a new enabled feature to the pool\n"
  72             "        -d <desc> sets the feature's description\n"
  73             "        -r set read-only compatible flag for feature\n"
  74             "    feature ref [-md] <pool> <feature>\n"
  75             "        change the refcount on the given feature\n"
  76             "        -d decrease instead of increase the refcount\n"
  77             "        -m add the feature to the label if increasing refcount\n"
  78             "\n"
  79             "    <feature> : should be a feature guid\n");
  80         exit(1);
  81 }
  82
  83
  84 static __attribute__((noreturn)) __attribute__((format(printf, 3, 4))) void
  85 fatal(spa_t *spa, void *tag, const char *fmt, ...)
  86 {
  87         va_list ap;
  88
  89         if (spa != NULL) {
  90                 spa_close(spa, tag);
  91                 (void) spa_export(g_pool, NULL, B_TRUE, B_FALSE);
  92         }
  93
  94         va_start(ap, fmt);
  95         (void) fprintf(stderr, "%s: ", cmdname);
  96         (void) vfprintf(stderr, fmt, ap);
  97         va_end(ap);
  98         (void) fprintf(stderr, "\n");
  99
 100         exit(1);
 101 }
 102
 103 /* ARGSUSED */
 104 static int
 105 space_delta_cb(dmu_object_type_t bonustype, const void *data,
 106     zfs_file_info_t *zoi)
 107 {
 108         /*
 109          * Is it a valid type of object to track?
 110          */
 111         if (bonustype != DMU_OT_ZNODE && bonustype != DMU_OT_SA)
 112                 return (ENOENT);
 113         (void) fprintf(stderr, "modifying object that needs user accounting");
 114         abort();
 115 }
 116
 117 /*
 118  * Target is the dataset whose pool we want to open.
 119  */
 120 static void
 121 zhack_import(char *target, boolean_t readonly)
 122 {
 123         nvlist_t *config;
 124         nvlist_t *props;
 125         int error;
 126
 127         kernel_init(readonly ? SPA_MODE_READ :
 128             (SPA_MODE_READ | SPA_MODE_WRITE));
 129
 130         dmu_objset_register_type(DMU_OST_ZFS, space_delta_cb);
 131
 132         g_readonly = readonly;
 133         g_importargs.can_be_active = readonly;
 134         g_pool = strdup(target);
 135
 136         error = zpool_find_config(NULL, target, &config, &g_importargs,
 137             &libzpool_config_ops);
 138         if (error)
 139                 fatal(NULL, FTAG, "cannot import '%s'", target);
 140
 141         props = NULL;
 142         if (readonly) {
 143                 VERIFY(nvlist_alloc(&props, NV_UNIQUE_NAME, 0) == 0);
 144                 VERIFY(nvlist_add_uint64(props,
 145                     zpool_prop_to_name(ZPOOL_PROP_READONLY), 1) == 0);
 146         }
 147
 148         zfeature_checks_disable = B_TRUE;
 149         error = spa_import(target, config, props,
 150             (readonly ?  ZFS_IMPORT_SKIP_MMP : ZFS_IMPORT_NORMAL));
 151         fnvlist_free(config);
 152         zfeature_checks_disable = B_FALSE;
 153         if (error == EEXIST)
 154                 error = 0;
 155
 156         if (error)
 157                 fatal(NULL, FTAG, "can't import '%s': %s", target,
 158                     strerror(error));
 159 }
 160
 161 static void
 162 zhack_spa_open(char *target, boolean_t readonly, void *tag, spa_t **spa)
 163 {
 164         int err;
 165
 166         zhack_import(target, readonly);
 167
 168         zfeature_checks_disable = B_TRUE;
 169         err = spa_open(target, spa, tag);
 170         zfeature_checks_disable = B_FALSE;
 171
 172         if (err != 0)
 173                 fatal(*spa, FTAG, "cannot open '%s': %s", target,
 174                     strerror(err));
 175         if (spa_version(*spa) < SPA_VERSION_FEATURES) {
 176                 fatal(*spa, FTAG, "'%s' has version %d, features not enabled",
 177                     target, (int)spa_version(*spa));
 178         }
 179 }
 180
 181 static void
 182 dump_obj(objset_t *os, uint64_t obj, const char *name)
 183 {
 184         zap_cursor_t zc;
 185         zap_attribute_t za;
 186
 187         (void) printf("%s_obj:\n", name);
 188
 189         for (zap_cursor_init(&zc, os, obj);
 190             zap_cursor_retrieve(&zc, &za) == 0;
 191             zap_cursor_advance(&zc)) {
 192                 if (za.za_integer_length == 8) {
 193                         ASSERT(za.za_num_integers == 1);
 194                         (void) printf("\t%s = %llu\n",
 195                             za.za_name, (u_longlong_t)za.za_first_integer);
 196                 } else {
 197                         ASSERT(za.za_integer_length == 1);
 198                         char val[1024];
 199                         VERIFY(zap_lookup(os, obj, za.za_name,
 200                             1, sizeof (val), val) == 0);
 201                         (void) printf("\t%s = %s\n", za.za_name, val);
 202                 }
 203         }
 204         zap_cursor_fini(&zc);
 205 }
 206
 207 static void
 208 dump_mos(spa_t *spa)
 209 {
 210         nvlist_t *nv = spa->spa_label_features;
 211         nvpair_t *pair;
 212
 213         (void) printf("label config:\n");
 214         for (pair = nvlist_next_nvpair(nv, NULL);
 215             pair != NULL;
 216             pair = nvlist_next_nvpair(nv, pair)) {
 217                 (void) printf("\t%s\n", nvpair_name(pair));
 218         }
 219 }
 220
 221 static void
 222 zhack_do_feature_stat(int argc, char **argv)
 223 {
 224         spa_t *spa;
 225         objset_t *os;
 226         char *target;
 227
 228         argc--;
 229         argv++;
 230
 231         if (argc < 1) {
 232                 (void) fprintf(stderr, "error: missing pool name\n");
 233                 usage();
 234         }
 235         target = argv[0];
 236
 237         zhack_spa_open(target, B_TRUE, FTAG, &spa);
 238         os = spa->spa_meta_objset;
 239
 240         dump_obj(os, spa->spa_feat_for_read_obj, "for_read");
 241         dump_obj(os, spa->spa_feat_for_write_obj, "for_write");
 242         dump_obj(os, spa->spa_feat_desc_obj, "descriptions");
 243         if (spa_feature_is_active(spa, SPA_FEATURE_ENABLED_TXG)) {
 244                 dump_obj(os, spa->spa_feat_enabled_txg_obj, "enabled_txg");
 245         }
 246         dump_mos(spa);
 247
 248         spa_close(spa, FTAG);
 249 }
 250
 251 static void
 252 zhack_feature_enable_sync(void *arg, dmu_tx_t *tx)
 253 {
 254         spa_t *spa = dmu_tx_pool(tx)->dp_spa;
 255         zfeature_info_t *feature = arg;
 256
 257         feature_enable_sync(spa, feature, tx);
 258
 259         spa_history_log_internal(spa, "zhack enable feature", tx,
 260             "name=%s flags=%u",
 261             feature->fi_guid, feature->fi_flags);
 262 }
 263
 264 static void
 265 zhack_do_feature_enable(int argc, char **argv)
 266 {
 267         int c;
 268         char *desc, *target;
 269         spa_t *spa;
 270         objset_t *mos;
 271         zfeature_info_t feature;
 272         spa_feature_t nodeps[] = { SPA_FEATURE_NONE };
 273
 274         /*
 275          * Features are not added to the pool's label until their refcounts
 276          * are incremented, so fi_mos can just be left as false for now.
 277          */
 278         desc = NULL;
 279         feature.fi_uname = "zhack";
 280         feature.fi_flags = 0;
 281         feature.fi_depends = nodeps;
 282         feature.fi_feature = SPA_FEATURE_NONE;
 283
 284         optind = 1;
 285         while ((c = getopt(argc, argv, "+rd:")) != -1) {
 286                 switch (c) {
 287                 case 'r':
 288                         feature.fi_flags |= ZFEATURE_FLAG_READONLY_COMPAT;
 289                         break;
 290                 case 'd':
 291                         desc = strdup(optarg);
 292                         break;
 293                 default:
 294                         usage();
 295                         break;
 296                 }
 297         }
 298
 299         if (desc == NULL)
 300                 desc = strdup("zhack injected");
 301         feature.fi_desc = desc;
 302
 303         argc -= optind;
 304         argv += optind;
 305
 306         if (argc < 2) {
 307                 (void) fprintf(stderr, "error: missing feature or pool name\n");
 308                 usage();
 309         }
 310         target = argv[0];
 311         feature.fi_guid = argv[1];
 312
 313         if (!zfeature_is_valid_guid(feature.fi_guid))
 314                 fatal(NULL, FTAG, "invalid feature guid: %s", feature.fi_guid);
 315
 316         zhack_spa_open(target, B_FALSE, FTAG, &spa);
 317         mos = spa->spa_meta_objset;
 318
 319         if (zfeature_is_supported(feature.fi_guid))
 320                 fatal(spa, FTAG, "'%s' is a real feature, will not enable",
 321                     feature.fi_guid);
 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                     feature.fi_guid);
 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 }