xref: /illumos-gate/usr/src/cmd/zhack/zhack.c (revision aaceae985c2e78cadef76bf0b7b50ed887ccb3a6)
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 #undef verify
52 #include <libzutil.h>
53 
54 extern boolean_t zfeature_checks_disable;
55 
56 const char cmdname[] = "zhack";
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 [-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 	    "    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, void *data,
107     uint64_t *userp, uint64_t *groupp, uint64_t *projectp)
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 ? FREAD : (FREAD | FWRITE));
130 
131 	dmu_objset_register_type(DMU_OST_ZFS, space_delta_cb);
132 
133 	g_readonly = readonly;
134 	g_importargs.can_be_active = readonly;
135 	g_pool = strdup(target);
136 
137 	error = zpool_find_config(NULL, target, &config, &g_importargs,
138 	    &libzpool_config_ops);
139 	if (error)
140 		fatal(NULL, FTAG, "cannot import '%s'", target);
141 
142 	props = NULL;
143 	if (readonly) {
144 		VERIFY(nvlist_alloc(&props, NV_UNIQUE_NAME, 0) == 0);
145 		VERIFY(nvlist_add_uint64(props,
146 		    zpool_prop_to_name(ZPOOL_PROP_READONLY), 1) == 0);
147 	}
148 
149 	zfeature_checks_disable = B_TRUE;
150 	error = spa_import(target, config, props,
151 	    (readonly ?  ZFS_IMPORT_SKIP_MMP : ZFS_IMPORT_NORMAL));
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 
212 	(void) printf("label config:\n");
213 	for (nvpair_t *pair = nvlist_next_nvpair(nv, NULL);
214 	    pair != NULL;
215 	    pair = nvlist_next_nvpair(nv, pair)) {
216 		(void) printf("\t%s\n", nvpair_name(pair));
217 	}
218 }
219 
220 static void
221 zhack_do_feature_stat(int argc, char **argv)
222 {
223 	spa_t *spa;
224 	objset_t *os;
225 	char *target;
226 
227 	argc--;
228 	argv++;
229 
230 	if (argc < 1) {
231 		(void) fprintf(stderr, "error: missing pool name\n");
232 		usage();
233 	}
234 	target = argv[0];
235 
236 	zhack_spa_open(target, B_TRUE, FTAG, &spa);
237 	os = spa->spa_meta_objset;
238 
239 	dump_obj(os, spa->spa_feat_for_read_obj, "for_read");
240 	dump_obj(os, spa->spa_feat_for_write_obj, "for_write");
241 	dump_obj(os, spa->spa_feat_desc_obj, "descriptions");
242 	if (spa_feature_is_active(spa, SPA_FEATURE_ENABLED_TXG)) {
243 		dump_obj(os, spa->spa_feat_enabled_txg_obj, "enabled_txg");
244 	}
245 	dump_mos(spa);
246 
247 	spa_close(spa, FTAG);
248 }
249 
250 static void
251 zhack_feature_enable_sync(void *arg, dmu_tx_t *tx)
252 {
253 	spa_t *spa = dmu_tx_pool(tx)->dp_spa;
254 	zfeature_info_t *feature = arg;
255 
256 	feature_enable_sync(spa, feature, tx);
257 
258 	spa_history_log_internal(spa, "zhack enable feature", tx,
259 	    "guid=%s flags=%x",
260 	    feature->fi_guid, feature->fi_flags);
261 }
262 
263 static void
264 zhack_do_feature_enable(int argc, char **argv)
265 {
266 	int c;
267 	char *desc, *target;
268 	spa_t *spa;
269 	objset_t *mos;
270 	zfeature_info_t feature;
271 	spa_feature_t nodeps[] = { SPA_FEATURE_NONE };
272 
273 	/*
274 	 * Features are not added to the pool's label until their refcounts
275 	 * are incremented, so fi_mos can just be left as false for now.
276 	 */
277 	desc = NULL;
278 	feature.fi_uname = "zhack";
279 	feature.fi_flags = 0;
280 	feature.fi_depends = nodeps;
281 	feature.fi_feature = SPA_FEATURE_NONE;
282 
283 	optind = 1;
284 	while ((c = getopt(argc, argv, "rmd:")) != -1) {
285 		switch (c) {
286 		case 'r':
287 			feature.fi_flags |= ZFEATURE_FLAG_READONLY_COMPAT;
288 			break;
289 		case 'd':
290 			desc = strdup(optarg);
291 			break;
292 		default:
293 			usage();
294 			break;
295 		}
296 	}
297 
298 	if (desc == NULL)
299 		desc = strdup("zhack injected");
300 	feature.fi_desc = desc;
301 
302 	argc -= optind;
303 	argv += optind;
304 
305 	if (argc < 2) {
306 		(void) fprintf(stderr, "error: missing feature or pool name\n");
307 		usage();
308 	}
309 	target = argv[0];
310 	feature.fi_guid = argv[1];
311 
312 	if (!zfeature_is_valid_guid(feature.fi_guid))
313 		fatal(NULL, FTAG, "invalid feature guid: %s", feature.fi_guid);
314 
315 	zhack_spa_open(target, B_FALSE, FTAG, &spa);
316 	mos = spa->spa_meta_objset;
317 
318 	if (zfeature_is_supported(feature.fi_guid))
319 		fatal(spa, FTAG, "'%s' is a real feature, will not enable");
320 	if (0 == zap_contains(mos, spa->spa_feat_desc_obj, feature.fi_guid))
321 		fatal(spa, FTAG, "feature already enabled: %s",
322 		    feature.fi_guid);
323 
324 	VERIFY0(dsl_sync_task(spa_name(spa), NULL,
325 	    zhack_feature_enable_sync, &feature, 5, ZFS_SPACE_CHECK_NORMAL));
326 
327 	spa_close(spa, FTAG);
328 
329 	free(desc);
330 }
331 
332 static void
333 feature_incr_sync(void *arg, dmu_tx_t *tx)
334 {
335 	spa_t *spa = dmu_tx_pool(tx)->dp_spa;
336 	zfeature_info_t *feature = arg;
337 	uint64_t refcount;
338 
339 	VERIFY0(feature_get_refcount_from_disk(spa, feature, &refcount));
340 	feature_sync(spa, feature, refcount + 1, tx);
341 	spa_history_log_internal(spa, "zhack feature incr", tx,
342 	    "guid=%s", feature->fi_guid);
343 }
344 
345 static void
346 feature_decr_sync(void *arg, dmu_tx_t *tx)
347 {
348 	spa_t *spa = dmu_tx_pool(tx)->dp_spa;
349 	zfeature_info_t *feature = arg;
350 	uint64_t refcount;
351 
352 	VERIFY0(feature_get_refcount_from_disk(spa, feature, &refcount));
353 	feature_sync(spa, feature, refcount - 1, tx);
354 	spa_history_log_internal(spa, "zhack feature decr", tx,
355 	    "guid=%s", feature->fi_guid);
356 }
357 
358 static void
359 zhack_do_feature_ref(int argc, char **argv)
360 {
361 	int c;
362 	char *target;
363 	boolean_t decr = B_FALSE;
364 	spa_t *spa;
365 	objset_t *mos;
366 	zfeature_info_t feature;
367 	spa_feature_t nodeps[] = { SPA_FEATURE_NONE };
368 
369 	/*
370 	 * fi_desc does not matter here because it was written to disk
371 	 * when the feature was enabled, but we need to properly set the
372 	 * feature for read or write based on the information we read off
373 	 * disk later.
374 	 */
375 	feature.fi_uname = "zhack";
376 	feature.fi_flags = 0;
377 	feature.fi_desc = NULL;
378 	feature.fi_depends = nodeps;
379 	feature.fi_feature = SPA_FEATURE_NONE;
380 
381 	optind = 1;
382 	while ((c = getopt(argc, argv, "md")) != -1) {
383 		switch (c) {
384 		case 'm':
385 			feature.fi_flags |= ZFEATURE_FLAG_MOS;
386 			break;
387 		case 'd':
388 			decr = B_TRUE;
389 			break;
390 		default:
391 			usage();
392 			break;
393 		}
394 	}
395 	argc -= optind;
396 	argv += optind;
397 
398 	if (argc < 2) {
399 		(void) fprintf(stderr, "error: missing feature or pool name\n");
400 		usage();
401 	}
402 	target = argv[0];
403 	feature.fi_guid = argv[1];
404 
405 	if (!zfeature_is_valid_guid(feature.fi_guid))
406 		fatal(NULL, FTAG, "invalid feature guid: %s", feature.fi_guid);
407 
408 	zhack_spa_open(target, B_FALSE, FTAG, &spa);
409 	mos = spa->spa_meta_objset;
410 
411 	if (zfeature_is_supported(feature.fi_guid)) {
412 		fatal(spa, FTAG,
413 		    "'%s' is a real feature, will not change refcount");
414 	}
415 
416 	if (0 == zap_contains(mos, spa->spa_feat_for_read_obj,
417 	    feature.fi_guid)) {
418 		feature.fi_flags &= ~ZFEATURE_FLAG_READONLY_COMPAT;
419 	} else if (0 == zap_contains(mos, spa->spa_feat_for_write_obj,
420 	    feature.fi_guid)) {
421 		feature.fi_flags |= ZFEATURE_FLAG_READONLY_COMPAT;
422 	} else {
423 		fatal(spa, FTAG, "feature is not enabled: %s", feature.fi_guid);
424 	}
425 
426 	if (decr) {
427 		uint64_t count;
428 		if (feature_get_refcount_from_disk(spa, &feature,
429 		    &count) == 0 && count != 0) {
430 			fatal(spa, FTAG, "feature refcount already 0: %s",
431 			    feature.fi_guid);
432 		}
433 	}
434 
435 	VERIFY0(dsl_sync_task(spa_name(spa), NULL,
436 	    decr ? feature_decr_sync : feature_incr_sync, &feature,
437 	    5, ZFS_SPACE_CHECK_NORMAL));
438 
439 	spa_close(spa, FTAG);
440 }
441 
442 static int
443 zhack_do_feature(int argc, char **argv)
444 {
445 	char *subcommand;
446 
447 	argc--;
448 	argv++;
449 	if (argc == 0) {
450 		(void) fprintf(stderr,
451 		    "error: no feature operation specified\n");
452 		usage();
453 	}
454 
455 	subcommand = argv[0];
456 	if (strcmp(subcommand, "stat") == 0) {
457 		zhack_do_feature_stat(argc, argv);
458 	} else if (strcmp(subcommand, "enable") == 0) {
459 		zhack_do_feature_enable(argc, argv);
460 	} else if (strcmp(subcommand, "ref") == 0) {
461 		zhack_do_feature_ref(argc, argv);
462 	} else {
463 		(void) fprintf(stderr, "error: unknown subcommand: %s\n",
464 		    subcommand);
465 		usage();
466 	}
467 
468 	return (0);
469 }
470 
471 #define	MAX_NUM_PATHS 1024
472 
473 int
474 main(int argc, char **argv)
475 {
476 	extern void zfs_prop_init(void);
477 
478 	char *path[MAX_NUM_PATHS];
479 	const char *subcommand;
480 	int rv = 0;
481 	int c;
482 
483 	g_importargs.path = path;
484 
485 	dprintf_setup(&argc, argv);
486 	zfs_prop_init();
487 
488 	while ((c = getopt(argc, argv, "c:d:")) != -1) {
489 		switch (c) {
490 		case 'c':
491 			g_importargs.cachefile = optarg;
492 			break;
493 		case 'd':
494 			assert(g_importargs.paths < MAX_NUM_PATHS);
495 			g_importargs.path[g_importargs.paths++] = optarg;
496 			break;
497 		default:
498 			usage();
499 			break;
500 		}
501 	}
502 
503 	argc -= optind;
504 	argv += optind;
505 	optind = 1;
506 
507 	if (argc == 0) {
508 		(void) fprintf(stderr, "error: no command specified\n");
509 		usage();
510 	}
511 
512 	subcommand = argv[0];
513 
514 	if (strcmp(subcommand, "feature") == 0) {
515 		rv = zhack_do_feature(argc, argv);
516 	} else {
517 		(void) fprintf(stderr, "error: unknown subcommand: %s\n",
518 		    subcommand);
519 		usage();
520 	}
521 
522 	if (!g_readonly && spa_export(g_pool, NULL, B_TRUE, B_FALSE) != 0) {
523 		fatal(NULL, FTAG, "pool export failed; "
524 		    "changes may not be committed to disk\n");
525 	}
526 
527 	kernel_fini();
528 
529 	return (rv);
530 }
531