cddl/contrib/opensolaris/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) 2013 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 #undef ZFS_MAXNAMELEN
  52 #undef verify
  53 #include <libzfs.h>
  54
  55 extern boolean_t zfeature_checks_disable;
  56
  57 const char cmdname[] = "zhack";
  58 libzfs_handle_t *g_zfs;
  59 static importargs_t g_importargs;
  60 static char *g_pool;
  61 static boolean_t g_readonly;
  62
  63 static void
  64 usage(void)
  65 {
  66         (void) fprintf(stderr,
  67             "Usage: %s [-c cachefile] [-d dir] <subcommand> <args> ...\n"
  68             "where <subcommand> <args> is one of the following:\n"
  69             "\n", cmdname);
  70
  71         (void) fprintf(stderr,
  72             "    feature stat <pool>\n"
  73             "        print information about enabled features\n"
  74             "    feature enable [-d desc] <pool> <feature>\n"
  75             "        add a new enabled feature to the pool\n"
  76             "        -d <desc> sets the feature's description\n"
  77             "    feature ref [-md] <pool> <feature>\n"
  78             "        change the refcount on the given feature\n"
  79             "        -d decrease instead of increase the refcount\n"
  80             "        -m add the feature to the label if increasing refcount\n"
  81             "\n"
  82             "    <feature> : should be a feature guid\n");
  83         exit(1);
  84 }
  85
  86
  87 static void
  88 fatal(spa_t *spa, void *tag, const char *fmt, ...)
  89 {
  90         va_list ap;
  91
  92         if (spa != NULL) {
  93                 spa_close(spa, tag);
  94                 (void) spa_export(g_pool, NULL, B_TRUE, B_FALSE);
  95         }
  96
  97         va_start(ap, fmt);
  98         (void) fprintf(stderr, "%s: ", cmdname);
  99         (void) vfprintf(stderr, fmt, ap);
 100         va_end(ap);
 101         (void) fprintf(stderr, "\n");
 102
 103         exit(1);
 104 }
 105
 106 /* ARGSUSED */
 107 static int
 108 space_delta_cb(dmu_object_type_t bonustype, void *data,
 109     uint64_t *userp, uint64_t *groupp)
 110 {
 111         /*
 112          * Is it a valid type of object to track?
 113          */
 114         if (bonustype != DMU_OT_ZNODE && bonustype != DMU_OT_SA)
 115                 return (ENOENT);
 116         (void) fprintf(stderr, "modifying object that needs user accounting");
 117         abort();
 118         /* NOTREACHED */
 119 }
 120
 121 /*
 122  * Target is the dataset whose pool we want to open.
 123  */
 124 static void
 125 import_pool(const char *target, boolean_t readonly)
 126 {
 127         nvlist_t *config;
 128         nvlist_t *pools;
 129         int error;
 130         char *sepp;
 131         spa_t *spa;
 132         nvpair_t *elem;
 133         nvlist_t *props;
 134         const char *name;
 135
 136         kernel_init(readonly ? FREAD : (FREAD | FWRITE));
 137         g_zfs = libzfs_init();
 138         ASSERT(g_zfs != NULL);
 139
 140         dmu_objset_register_type(DMU_OST_ZFS, space_delta_cb);
 141
 142         g_readonly = readonly;
 143
 144         /*
 145          * If we only want readonly access, it's OK if we find
 146          * a potentially-active (ie, imported into the kernel) pool from the
 147          * default cachefile.
 148          */
 149         if (readonly && spa_open(target, &spa, FTAG) == 0) {
 150                 spa_close(spa, FTAG);
 151                 return;
 152         }
 153
 154         g_importargs.unique = B_TRUE;
 155         g_importargs.can_be_active = readonly;
 156         g_pool = strdup(target);
 157         if ((sepp = strpbrk(g_pool, "/@")) != NULL)
 158                 *sepp = '\0';
 159         g_importargs.poolname = g_pool;
 160         pools = zpool_search_import(g_zfs, &g_importargs);
 161
 162         if (nvlist_empty(pools)) {
 163                 if (!g_importargs.can_be_active) {
 164                         g_importargs.can_be_active = B_TRUE;
 165                         if (zpool_search_import(g_zfs, &g_importargs) != NULL ||
 166                             spa_open(target, &spa, FTAG) == 0) {
 167                                 fatal(spa, FTAG, "cannot import '%s': pool is "
 168                                     "active; run " "\"zpool export %s\" "
 169                                     "first\n", g_pool, g_pool);
 170                         }
 171                 }
 172
 173                 fatal(NULL, FTAG, "cannot import '%s': no such pool "
 174                     "available\n", g_pool);
 175         }
 176
 177         elem = nvlist_next_nvpair(pools, NULL);
 178         name = nvpair_name(elem);
 179         verify(nvpair_value_nvlist(elem, &config) == 0);
 180
 181         props = NULL;
 182         if (readonly) {
 183                 verify(nvlist_alloc(&props, NV_UNIQUE_NAME, 0) == 0);
 184                 verify(nvlist_add_uint64(props,
 185                     zpool_prop_to_name(ZPOOL_PROP_READONLY), 1) == 0);
 186         }
 187
 188         zfeature_checks_disable = B_TRUE;
 189         error = spa_import(name, config, props, ZFS_IMPORT_NORMAL);
 190         zfeature_checks_disable = B_FALSE;
 191         if (error == EEXIST)
 192                 error = 0;
 193
 194         if (error)
 195                 fatal(NULL, FTAG, "can't import '%s': %s", name,
 196                     strerror(error));
 197 }
 198
 199 static void
 200 zhack_spa_open(const char *target, boolean_t readonly, void *tag, spa_t **spa)
 201 {
 202         int err;
 203
 204         import_pool(target, readonly);
 205
 206         zfeature_checks_disable = B_TRUE;
 207         err = spa_open(target, spa, tag);
 208         zfeature_checks_disable = B_FALSE;
 209
 210         if (err != 0)
 211                 fatal(*spa, FTAG, "cannot open '%s': %s", target,
 212                     strerror(err));
 213         if (spa_version(*spa) < SPA_VERSION_FEATURES) {
 214                 fatal(*spa, FTAG, "'%s' has version %d, features not enabled",
 215                     target, (int)spa_version(*spa));
 216         }
 217 }
 218
 219 static void
 220 dump_obj(objset_t *os, uint64_t obj, const char *name)
 221 {
 222         zap_cursor_t zc;
 223         zap_attribute_t za;
 224
 225         (void) printf("%s_obj:\n", name);
 226
 227         for (zap_cursor_init(&zc, os, obj);
 228             zap_cursor_retrieve(&zc, &za) == 0;
 229             zap_cursor_advance(&zc)) {
 230                 if (za.za_integer_length == 8) {
 231                         ASSERT(za.za_num_integers == 1);
 232                         (void) printf("\t%s = %llu\n",
 233                             za.za_name, (u_longlong_t)za.za_first_integer);
 234                 } else {
 235                         ASSERT(za.za_integer_length == 1);
 236                         char val[1024];
 237                         VERIFY(zap_lookup(os, obj, za.za_name,
 238                             1, sizeof (val), val) == 0);
 239                         (void) printf("\t%s = %s\n", za.za_name, val);
 240                 }
 241         }
 242         zap_cursor_fini(&zc);
 243 }
 244
 245 static void
 246 dump_mos(spa_t *spa)
 247 {
 248         nvlist_t *nv = spa->spa_label_features;
 249
 250         (void) printf("label config:\n");
 251         for (nvpair_t *pair = nvlist_next_nvpair(nv, NULL);
 252             pair != NULL;
 253             pair = nvlist_next_nvpair(nv, pair)) {
 254                 (void) printf("\t%s\n", nvpair_name(pair));
 255         }
 256 }
 257
 258 static void
 259 zhack_do_feature_stat(int argc, char **argv)
 260 {
 261         spa_t *spa;
 262         objset_t *os;
 263         char *target;
 264
 265         argc--;
 266         argv++;
 267
 268         if (argc < 1) {
 269                 (void) fprintf(stderr, "error: missing pool name\n");
 270                 usage();
 271         }
 272         target = argv[0];
 273
 274         zhack_spa_open(target, B_TRUE, FTAG, &spa);
 275         os = spa->spa_meta_objset;
 276
 277         dump_obj(os, spa->spa_feat_for_read_obj, "for_read");
 278         dump_obj(os, spa->spa_feat_for_write_obj, "for_write");
 279         dump_obj(os, spa->spa_feat_desc_obj, "descriptions");
 280         dump_mos(spa);
 281
 282         spa_close(spa, FTAG);
 283 }
 284
 285 static void
 286 feature_enable_sync(void *arg, dmu_tx_t *tx)
 287 {
 288         spa_t *spa = dmu_tx_pool(tx)->dp_spa;
 289         zfeature_info_t *feature = arg;
 290
 291         spa_feature_enable(spa, feature, tx);
 292         spa_history_log_internal(spa, "zhack enable feature", tx,
 293             "name=%s can_readonly=%u",
 294             feature->fi_guid, feature->fi_can_readonly);
 295 }
 296
 297 static void
 298 zhack_do_feature_enable(int argc, char **argv)
 299 {
 300         char c;
 301         char *desc, *target;
 302         spa_t *spa;
 303         objset_t *mos;
 304         zfeature_info_t feature;
 305         zfeature_info_t *nodeps[] = { NULL };
 306
 307         /*
 308          * Features are not added to the pool's label until their refcounts
 309          * are incremented, so fi_mos can just be left as false for now.
 310          */
 311         desc = NULL;
 312         feature.fi_uname = "zhack";
 313         feature.fi_mos = B_FALSE;
 314         feature.fi_can_readonly = B_FALSE;
 315         feature.fi_depends = nodeps;
 316
 317         optind = 1;
 318         while ((c = getopt(argc, argv, "rmd:")) != -1) {
 319                 switch (c) {
 320                 case 'r':
 321                         feature.fi_can_readonly = B_TRUE;
 322                         break;
 323                 case 'd':
 324                         desc = strdup(optarg);
 325                         break;
 326                 default:
 327                         usage();
 328                         break;
 329                 }
 330         }
 331
 332         if (desc == NULL)
 333                 desc = strdup("zhack injected");
 334         feature.fi_desc = desc;
 335
 336         argc -= optind;
 337         argv += optind;
 338
 339         if (argc < 2) {
 340                 (void) fprintf(stderr, "error: missing feature or pool name\n");
 341                 usage();
 342         }
 343         target = argv[0];
 344         feature.fi_guid = argv[1];
 345
 346         if (!zfeature_is_valid_guid(feature.fi_guid))
 347                 fatal(NULL, FTAG, "invalid feature guid: %s", feature.fi_guid);
 348
 349         zhack_spa_open(target, B_FALSE, FTAG, &spa);
 350         mos = spa->spa_meta_objset;
 351
 352         if (0 == zfeature_lookup_guid(feature.fi_guid, NULL))
 353                 fatal(spa, FTAG, "'%s' is a real feature, will not enable");
 354         if (0 == zap_contains(mos, spa->spa_feat_desc_obj, feature.fi_guid))
 355                 fatal(spa, FTAG, "feature already enabled: %s",
 356                     feature.fi_guid);
 357
 358         VERIFY0(dsl_sync_task(spa_name(spa), NULL,
 359             feature_enable_sync, &feature, 5));
 360
 361         spa_close(spa, FTAG);
 362
 363         free(desc);
 364 }
 365
 366 static void
 367 feature_incr_sync(void *arg, dmu_tx_t *tx)
 368 {
 369         spa_t *spa = dmu_tx_pool(tx)->dp_spa;
 370         zfeature_info_t *feature = arg;
 371
 372         spa_feature_incr(spa, feature, tx);
 373         spa_history_log_internal(spa, "zhack feature incr", tx,
 374             "name=%s", feature->fi_guid);
 375 }
 376
 377 static void
 378 feature_decr_sync(void *arg, dmu_tx_t *tx)
 379 {
 380         spa_t *spa = dmu_tx_pool(tx)->dp_spa;
 381         zfeature_info_t *feature = arg;
 382
 383         spa_feature_decr(spa, feature, tx);
 384         spa_history_log_internal(spa, "zhack feature decr", tx,
 385             "name=%s", feature->fi_guid);
 386 }
 387
 388 static void
 389 zhack_do_feature_ref(int argc, char **argv)
 390 {
 391         char c;
 392         char *target;
 393         boolean_t decr = B_FALSE;
 394         spa_t *spa;
 395         objset_t *mos;
 396         zfeature_info_t feature;
 397         zfeature_info_t *nodeps[] = { NULL };
 398
 399         /*
 400          * fi_desc does not matter here because it was written to disk
 401          * when the feature was enabled, but we need to properly set the
 402          * feature for read or write based on the information we read off
 403          * disk later.
 404          */
 405         feature.fi_uname = "zhack";
 406         feature.fi_mos = B_FALSE;
 407         feature.fi_desc = NULL;
 408         feature.fi_depends = nodeps;
 409
 410         optind = 1;
 411         while ((c = getopt(argc, argv, "md")) != -1) {
 412                 switch (c) {
 413                 case 'm':
 414                         feature.fi_mos = B_TRUE;
 415                         break;
 416                 case 'd':
 417                         decr = B_TRUE;
 418                         break;
 419                 default:
 420                         usage();
 421                         break;
 422                 }
 423         }
 424         argc -= optind;
 425         argv += optind;
 426
 427         if (argc < 2) {
 428                 (void) fprintf(stderr, "error: missing feature or pool name\n");
 429                 usage();
 430         }
 431         target = argv[0];
 432         feature.fi_guid = argv[1];
 433
 434         if (!zfeature_is_valid_guid(feature.fi_guid))
 435                 fatal(NULL, FTAG, "invalid feature guid: %s", feature.fi_guid);
 436
 437         zhack_spa_open(target, B_FALSE, FTAG, &spa);
 438         mos = spa->spa_meta_objset;
 439
 440         if (0 == zfeature_lookup_guid(feature.fi_guid, NULL))
 441                 fatal(spa, FTAG, "'%s' is a real feature, will not change "
 442                     "refcount");
 443
 444         if (0 == zap_contains(mos, spa->spa_feat_for_read_obj,
 445             feature.fi_guid)) {
 446                 feature.fi_can_readonly = B_FALSE;
 447         } else if (0 == zap_contains(mos, spa->spa_feat_for_write_obj,
 448             feature.fi_guid)) {
 449                 feature.fi_can_readonly = B_TRUE;
 450         } else {
 451                 fatal(spa, FTAG, "feature is not enabled: %s", feature.fi_guid);
 452         }
 453
 454         if (decr && !spa_feature_is_active(spa, &feature))
 455                 fatal(spa, FTAG, "feature refcount already 0: %s",
 456                     feature.fi_guid);
 457
 458         VERIFY0(dsl_sync_task(spa_name(spa), NULL,
 459             decr ? feature_decr_sync : feature_incr_sync, &feature, 5));
 460
 461         spa_close(spa, FTAG);
 462 }
 463
 464 static int
 465 zhack_do_feature(int argc, char **argv)
 466 {
 467         char *subcommand;
 468
 469         argc--;
 470         argv++;
 471         if (argc == 0) {
 472                 (void) fprintf(stderr,
 473                     "error: no feature operation specified\n");
 474                 usage();
 475         }
 476
 477         subcommand = argv[0];
 478         if (strcmp(subcommand, "stat") == 0) {
 479                 zhack_do_feature_stat(argc, argv);
 480         } else if (strcmp(subcommand, "enable") == 0) {
 481                 zhack_do_feature_enable(argc, argv);
 482         } else if (strcmp(subcommand, "ref") == 0) {
 483                 zhack_do_feature_ref(argc, argv);
 484         } else {
 485                 (void) fprintf(stderr, "error: unknown subcommand: %s\n",
 486                     subcommand);
 487                 usage();
 488         }
 489
 490         return (0);
 491 }
 492
 493 #define MAX_NUM_PATHS 1024
 494
 495 int
 496 main(int argc, char **argv)
 497 {
 498         extern void zfs_prop_init(void);
 499
 500         char *path[MAX_NUM_PATHS];
 501         const char *subcommand;
 502         int rv = 0;
 503         char c;
 504
 505         g_importargs.path = path;
 506
 507         dprintf_setup(&argc, argv);
 508         zfs_prop_init();
 509
 510         while ((c = getopt(argc, argv, "c:d:")) != -1) {
 511                 switch (c) {
 512                 case 'c':
 513                         g_importargs.cachefile = optarg;
 514                         break;
 515                 case 'd':
 516                         assert(g_importargs.paths < MAX_NUM_PATHS);
 517                         g_importargs.path[g_importargs.paths++] = optarg;
 518                         break;
 519                 default:
 520                         usage();
 521                         break;
 522                 }
 523         }
 524
 525         argc -= optind;
 526         argv += optind;
 527         optind = 1;
 528
 529         if (argc == 0) {
 530                 (void) fprintf(stderr, "error: no command specified\n");
 531                 usage();
 532         }
 533
 534         subcommand = argv[0];
 535
 536         if (strcmp(subcommand, "feature") == 0) {
 537                 rv = zhack_do_feature(argc, argv);
 538         } else {
 539                 (void) fprintf(stderr, "error: unknown subcommand: %s\n",
 540                     subcommand);
 541                 usage();
 542         }
 543
 544         if (!g_readonly && spa_export(g_pool, NULL, B_TRUE, B_FALSE) != 0) {
 545                 fatal(NULL, FTAG, "pool export failed; "
 546                     "changes may not be committed to disk\n");
 547         }
 548
 549         libzfs_fini(g_zfs);
 550         kernel_fini();
 551
 552         return (rv);
 553 }