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) 2012 by Delphix. All rights reserved.
  24  */
  25
  26 /*
  27  * zhack is a debugging tool that can write changes to ZFS pool using libzpool
  28  * for testing purposes. Altering pools with zhack is unsupported and may
  29  * result in corrupted pools.
  30  */
  31
  32 #include <stdio.h>
  33 #include <stdlib.h>
  34 #include <ctype.h>
  35 #include <sys/zfs_context.h>
  36 #include <sys/spa.h>
  37 #include <sys/spa_impl.h>
  38 #include <sys/dmu.h>
  39 #include <sys/zap.h>
  40 #include <sys/zfs_znode.h>
  41 #include <sys/dsl_synctask.h>
  42 #include <sys/vdev.h>
  43 #include <sys/fs/zfs.h>
  44 #include <sys/dmu_objset.h>
  45 #include <sys/dsl_pool.h>
  46 #include <sys/zio_checksum.h>
  47 #include <sys/zio_compress.h>
  48 #include <sys/zfeature.h>
  49 #undef ZFS_MAXNAMELEN
  50 #include <libzfs.h>
  51
  52 extern boolean_t zfeature_checks_disable;
  53
  54 const char cmdname[] = "zhack";
  55 libzfs_handle_t *g_zfs;
  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 [-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             "    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 void
  85 fatal(const char *fmt, ...)
  86 {
  87         va_list ap;
  88
  89         va_start(ap, fmt);
  90         (void) fprintf(stderr, "%s: ", cmdname);
  91         (void) vfprintf(stderr, fmt, ap);
  92         va_end(ap);
  93         (void) fprintf(stderr, "\n");
  94
  95         exit(1);
  96 }
  97
  98 /* ARGSUSED */
  99 static int
 100 space_delta_cb(dmu_object_type_t bonustype, void *data,
 101     uint64_t *userp, uint64_t *groupp)
 102 {
 103         /*
 104          * Is it a valid type of object to track?
 105          */
 106         if (bonustype != DMU_OT_ZNODE && bonustype != DMU_OT_SA)
 107                 return (ENOENT);
 108         (void) fprintf(stderr, "modifying object that needs user accounting");
 109         abort();
 110         /* NOTREACHED */
 111 }
 112
 113 /*
 114  * Target is the dataset whose pool we want to open.
 115  */
 116 static void
 117 import_pool(const char *target, boolean_t readonly)
 118 {
 119         nvlist_t *config;
 120         nvlist_t *pools;
 121         int error;
 122         char *sepp;
 123         spa_t *spa;
 124         nvpair_t *elem;
 125         nvlist_t *props;
 126         const char *name;
 127
 128         kernel_init(readonly ? FREAD : (FREAD | FWRITE));
 129         g_zfs = libzfs_init();
 130         ASSERT(g_zfs != NULL);
 131
 132         dmu_objset_register_type(DMU_OST_ZFS, space_delta_cb);
 133
 134         g_readonly = readonly;
 135
 136         /*
 137          * If we only want readonly access, it's OK if we find
 138          * a potentially-active (ie, imported into the kernel) pool from the
 139          * default cachefile.
 140          */
 141         if (readonly && spa_open(target, &spa, FTAG) == 0) {
 142                 spa_close(spa, FTAG);
 143                 return;
 144         }
 145
 146         g_importargs.unique = B_TRUE;
 147         g_importargs.can_be_active = readonly;
 148         g_pool = strdup(target);
 149         if ((sepp = strpbrk(g_pool, "/@")) != NULL)
 150                 *sepp = '\0';
 151         g_importargs.poolname = g_pool;
 152         pools = zpool_search_import(g_zfs, &g_importargs);
 153
 154         if (pools == NULL || nvlist_next_nvpair(pools, NULL) == NULL) {
 155                 if (!g_importargs.can_be_active) {
 156                         g_importargs.can_be_active = B_TRUE;
 157                         if (zpool_search_import(g_zfs, &g_importargs) != NULL ||
 158                             spa_open(target, &spa, FTAG) == 0) {
 159                                 fatal("cannot import '%s': pool is active; run "
 160                                     "\"zpool export %s\" first\n",
 161                                     g_pool, g_pool);
 162                         }
 163                 }
 164
 165                 fatal("cannot import '%s': no such pool available\n", g_pool);
 166         }
 167
 168         elem = nvlist_next_nvpair(pools, NULL);
 169         name = nvpair_name(elem);
 170         VERIFY(nvpair_value_nvlist(elem, &config) == 0);
 171
 172         props = NULL;
 173         if (readonly) {
 174                 VERIFY(nvlist_alloc(&props, NV_UNIQUE_NAME, 0) == 0);
 175                 VERIFY(nvlist_add_uint64(props,
 176                     zpool_prop_to_name(ZPOOL_PROP_READONLY), 1) == 0);
 177         }
 178
 179         zfeature_checks_disable = B_TRUE;
 180         error = spa_import(name, config, props, ZFS_IMPORT_NORMAL);
 181         zfeature_checks_disable = B_FALSE;
 182         if (error == EEXIST)
 183                 error = 0;
 184
 185         if (error)
 186                 fatal("can't import '%s': %s", name, strerror(error));
 187 }
 188
 189 static void
 190 zhack_spa_open(const char *target, boolean_t readonly, void *tag, spa_t **spa)
 191 {
 192         int err;
 193
 194         import_pool(target, readonly);
 195
 196         zfeature_checks_disable = B_TRUE;
 197         err = spa_open(target, spa, tag);
 198         zfeature_checks_disable = B_FALSE;
 199
 200         if (err != 0)
 201                 fatal("cannot open '%s': %s", target, strerror(err));
 202         if (spa_version(*spa) < SPA_VERSION_FEATURES) {
 203                 fatal("'%s' has version %d, features not enabled", target,
 204                     (int)spa_version(*spa));
 205         }
 206 }
 207
 208 static void
 209 dump_obj(objset_t *os, uint64_t obj, const char *name)
 210 {
 211         zap_cursor_t zc;
 212         zap_attribute_t za;
 213
 214         (void) printf("%s_obj:\n", name);
 215
 216         for (zap_cursor_init(&zc, os, obj);
 217             zap_cursor_retrieve(&zc, &za) == 0;
 218             zap_cursor_advance(&zc)) {
 219                 if (za.za_integer_length == 8) {
 220                         ASSERT(za.za_num_integers == 1);
 221                         (void) printf("\t%s = %llu\n",
 222                             za.za_name, (u_longlong_t)za.za_first_integer);
 223                 } else {
 224                         ASSERT(za.za_integer_length == 1);
 225                         char val[1024];
 226                         VERIFY(zap_lookup(os, obj, za.za_name,
 227                             1, sizeof (val), val) == 0);
 228                         (void) printf("\t%s = %s\n", za.za_name, val);
 229                 }
 230         }
 231         zap_cursor_fini(&zc);
 232 }
 233
 234 static void
 235 dump_mos(spa_t *spa)
 236 {
 237         nvlist_t *nv = spa->spa_label_features;
 238         nvpair_t *pair;
 239
 240         (void) printf("label config:\n");
 241         for (pair = nvlist_next_nvpair(nv, NULL);
 242             pair != NULL;
 243             pair = nvlist_next_nvpair(nv, pair)) {
 244                 (void) printf("\t%s\n", nvpair_name(pair));
 245         }
 246 }
 247
 248 static void
 249 zhack_do_feature_stat(int argc, char **argv)
 250 {
 251         spa_t *spa;
 252         objset_t *os;
 253         char *target;
 254
 255         argc--;
 256         argv++;
 257
 258         if (argc < 1) {
 259                 (void) fprintf(stderr, "error: missing pool name\n");
 260                 usage();
 261         }
 262         target = argv[0];
 263
 264         zhack_spa_open(target, B_TRUE, FTAG, &spa);
 265         os = spa->spa_meta_objset;
 266
 267         dump_obj(os, spa->spa_feat_for_read_obj, "for_read");
 268         dump_obj(os, spa->spa_feat_for_write_obj, "for_write");
 269         dump_obj(os, spa->spa_feat_desc_obj, "descriptions");
 270         dump_mos(spa);
 271
 272         spa_close(spa, FTAG);
 273 }
 274
 275 static void
 276 feature_enable_sync(void *arg1, void *arg2, dmu_tx_t *tx)
 277 {
 278         spa_t *spa = arg1;
 279         zfeature_info_t *feature = arg2;
 280
 281         spa_feature_enable(spa, feature, tx);
 282 }
 283
 284 static void
 285 zhack_do_feature_enable(int argc, char **argv)
 286 {
 287         char c;
 288         char *desc, *target;
 289         spa_t *spa;
 290         objset_t *mos;
 291         zfeature_info_t feature;
 292         zfeature_info_t *nodeps[] = { NULL };
 293
 294         /*
 295          * Features are not added to the pool's label until their refcounts
 296          * are incremented, so fi_mos can just be left as false for now.
 297          */
 298         desc = NULL;
 299         feature.fi_uname = "zhack";
 300         feature.fi_mos = B_FALSE;
 301         feature.fi_can_readonly = B_FALSE;
 302         feature.fi_depends = nodeps;
 303
 304         optind = 1;
 305         while ((c = getopt(argc, argv, "rmd:")) != -1) {
 306                 switch (c) {
 307                 case 'r':
 308                         feature.fi_can_readonly = B_TRUE;
 309                         break;
 310                 case 'd':
 311                         desc = strdup(optarg);
 312                         break;
 313                 default:
 314                         usage();
 315                         break;
 316                 }
 317         }
 318
 319         if (desc == NULL)
 320                 desc = strdup("zhack injected");
 321         feature.fi_desc = desc;
 322
 323         argc -= optind;
 324         argv += optind;
 325
 326         if (argc < 2) {
 327                 (void) fprintf(stderr, "error: missing feature or pool name\n");
 328                 usage();
 329         }
 330         target = argv[0];
 331         feature.fi_guid = argv[1];
 332
 333         if (!zfeature_is_valid_guid(feature.fi_guid))
 334                 fatal("invalid feature guid: %s", feature.fi_guid);
 335
 336         zhack_spa_open(target, B_FALSE, FTAG, &spa);
 337         mos = spa->spa_meta_objset;
 338
 339         if (0 == zfeature_lookup_guid(feature.fi_guid, NULL))
 340                 fatal("'%s' is a real feature, will not enable");
 341         if (0 == zap_contains(mos, spa->spa_feat_desc_obj, feature.fi_guid))
 342                 fatal("feature already enabled: %s", feature.fi_guid);
 343
 344         VERIFY3U(0, ==, dsl_sync_task_do(spa->spa_dsl_pool, NULL,
 345             feature_enable_sync, spa, &feature, 5));
 346
 347         spa_close(spa, FTAG);
 348
 349         free(desc);
 350 }
 351
 352 static void
 353 feature_incr_sync(void *arg1, void *arg2, dmu_tx_t *tx)
 354 {
 355         spa_t *spa = arg1;
 356         zfeature_info_t *feature = arg2;
 357
 358         spa_feature_incr(spa, feature, tx);
 359 }
 360
 361 static void
 362 feature_decr_sync(void *arg1, void *arg2, dmu_tx_t *tx)
 363 {
 364         spa_t *spa = arg1;
 365         zfeature_info_t *feature = arg2;
 366
 367         spa_feature_decr(spa, feature, tx);
 368 }
 369
 370 static void
 371 zhack_do_feature_ref(int argc, char **argv)
 372 {
 373         char c;
 374         char *target;
 375         boolean_t decr = B_FALSE;
 376         spa_t *spa;
 377         objset_t *mos;
 378         zfeature_info_t feature;
 379         zfeature_info_t *nodeps[] = { NULL };
 380
 381         /*
 382          * fi_desc does not matter here because it was written to disk
 383          * when the feature was enabled, but we need to properly set the
 384          * feature for read or write based on the information we read off
 385          * disk later.
 386          */
 387         feature.fi_uname = "zhack";
 388         feature.fi_mos = B_FALSE;
 389         feature.fi_desc = NULL;
 390         feature.fi_depends = nodeps;
 391
 392         optind = 1;
 393         while ((c = getopt(argc, argv, "md")) != -1) {
 394                 switch (c) {
 395                 case 'm':
 396                         feature.fi_mos = B_TRUE;
 397                         break;
 398                 case 'd':
 399                         decr = B_TRUE;
 400                         break;
 401                 default:
 402                         usage();
 403                         break;
 404                 }
 405         }
 406         argc -= optind;
 407         argv += optind;
 408
 409         if (argc < 2) {
 410                 (void) fprintf(stderr, "error: missing feature or pool name\n");
 411                 usage();
 412         }
 413         target = argv[0];
 414         feature.fi_guid = argv[1];
 415
 416         if (!zfeature_is_valid_guid(feature.fi_guid))
 417                 fatal("invalid feature guid: %s", feature.fi_guid);
 418
 419         zhack_spa_open(target, B_FALSE, FTAG, &spa);
 420         mos = spa->spa_meta_objset;
 421
 422         if (0 == zfeature_lookup_guid(feature.fi_guid, NULL))
 423                 fatal("'%s' is a real feature, will not change refcount");
 424
 425         if (0 == zap_contains(mos, spa->spa_feat_for_read_obj,
 426             feature.fi_guid)) {
 427                 feature.fi_can_readonly = B_FALSE;
 428         } else if (0 == zap_contains(mos, spa->spa_feat_for_write_obj,
 429             feature.fi_guid)) {
 430                 feature.fi_can_readonly = B_TRUE;
 431         } else {
 432                 fatal("feature is not enabled: %s", feature.fi_guid);
 433         }
 434
 435         if (decr && !spa_feature_is_active(spa, &feature))
 436                 fatal("feature refcount already 0: %s", feature.fi_guid);
 437
 438         VERIFY3U(0, ==, dsl_sync_task_do(spa->spa_dsl_pool, NULL,
 439             decr ? feature_decr_sync : feature_incr_sync, spa, &feature, 5));
 440
 441         spa_close(spa, FTAG);
 442 }
 443
 444 static int
 445 zhack_do_feature(int argc, char **argv)
 446 {
 447         char *subcommand;
 448
 449         argc--;
 450         argv++;
 451         if (argc == 0) {
 452                 (void) fprintf(stderr,
 453                     "error: no feature operation specified\n");
 454                 usage();
 455         }
 456
 457         subcommand = argv[0];
 458         if (strcmp(subcommand, "stat") == 0) {
 459                 zhack_do_feature_stat(argc, argv);
 460         } else if (strcmp(subcommand, "enable") == 0) {
 461                 zhack_do_feature_enable(argc, argv);
 462         } else if (strcmp(subcommand, "ref") == 0) {
 463                 zhack_do_feature_ref(argc, argv);
 464         } else {
 465                 (void) fprintf(stderr, "error: unknown subcommand: %s\n",
 466                     subcommand);
 467                 usage();
 468         }
 469
 470         return (0);
 471 }
 472
 473 #define MAX_NUM_PATHS 1024
 474
 475 int
 476 main(int argc, char **argv)
 477 {
 478         extern void zfs_prop_init(void);
 479
 480         char *path[MAX_NUM_PATHS];
 481         const char *subcommand;
 482         int rv = 0;
 483         char c;
 484
 485         g_importargs.path = path;
 486
 487         dprintf_setup(&argc, argv);
 488         zfs_prop_init();
 489
 490         while ((c = getopt(argc, argv, "c:d:")) != -1) {
 491                 switch (c) {
 492                 case 'c':
 493                         g_importargs.cachefile = optarg;
 494                         break;
 495                 case 'd':
 496                         assert(g_importargs.paths < MAX_NUM_PATHS);
 497                         g_importargs.path[g_importargs.paths++] = optarg;
 498                         break;
 499                 default:
 500                         usage();
 501                         break;
 502                 }
 503         }
 504
 505         argc -= optind;
 506         argv += optind;
 507         optind = 1;
 508
 509         if (argc == 0) {
 510                 (void) fprintf(stderr, "error: no command specified\n");
 511                 usage();
 512         }
 513
 514         subcommand = argv[0];
 515
 516         if (strcmp(subcommand, "feature") == 0) {
 517                 rv = zhack_do_feature(argc, argv);
 518         } else {
 519                 (void) fprintf(stderr, "error: unknown subcommand: %s\n",
 520                     subcommand);
 521                 usage();
 522         }
 523
 524         if (!g_readonly && spa_export(g_pool, NULL, B_TRUE, B_TRUE) != 0) {
 525                 fatal("pool export failed; "
 526                     "changes may not be committed to disk\n");
 527         }
 528
 529         libzfs_fini(g_zfs);
 530         kernel_fini();
 531
 532         return (rv);
 533 }