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
usage(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
fatal(spa_t * spa,void * tag,const char * fmt,...)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
space_delta_cb(dmu_object_type_t bonustype,const void * data,zfs_file_info_t * zoi)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
zhack_import(char * target,boolean_t readonly)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
zhack_spa_open(char * target,boolean_t readonly,void * tag,spa_t ** spa)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
dump_obj(objset_t * os,uint64_t obj,const char * name)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
dump_mos(spa_t * spa)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
zhack_do_feature_stat(int argc,char ** argv)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
zhack_feature_enable_sync(void * arg,dmu_tx_t * tx)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
zhack_do_feature_enable(int argc,char ** argv)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
feature_incr_sync(void * arg,dmu_tx_t * tx)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
feature_decr_sync(void * arg,dmu_tx_t * tx)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
zhack_do_feature_ref(int argc,char ** argv)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
zhack_do_feature(int argc,char ** argv)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
main(int argc,char ** argv)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 }
534