xref: /titanic_50/usr/src/cmd/zhack/zhack.c (revision 40a5c998e5462ed47916e2edfcc5016073cf8851)
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 <libzfs.h>
53 
54 extern boolean_t zfeature_checks_disable;
55 
56 const char cmdname[] = "zhack";
57 libzfs_handle_t *g_zfs;
58 static importargs_t g_importargs;
59 static char *g_pool;
60 static boolean_t g_readonly;
61 
62 static void
usage(void)63 usage(void)
64 {
65 	(void) fprintf(stderr,
66 	    "Usage: %s [-c cachefile] [-d dir] <subcommand> <args> ...\n"
67 	    "where <subcommand> <args> is one of the following:\n"
68 	    "\n", cmdname);
69 
70 	(void) fprintf(stderr,
71 	    "    feature stat <pool>\n"
72 	    "        print information about enabled features\n"
73 	    "    feature enable [-d desc] <pool> <feature>\n"
74 	    "        add a new enabled feature to the pool\n"
75 	    "        -d <desc> sets the feature's description\n"
76 	    "    feature ref [-md] <pool> <feature>\n"
77 	    "        change the refcount on the given feature\n"
78 	    "        -d decrease instead of increase the refcount\n"
79 	    "        -m add the feature to the label if increasing refcount\n"
80 	    "\n"
81 	    "    <feature> : should be a feature guid\n");
82 	exit(1);
83 }
84 
85 
86 static void
fatal(spa_t * spa,void * tag,const char * fmt,...)87 fatal(spa_t *spa, void *tag, const char *fmt, ...)
88 {
89 	va_list ap;
90 
91 	if (spa != NULL) {
92 		spa_close(spa, tag);
93 		(void) spa_export(g_pool, NULL, B_TRUE, B_FALSE);
94 	}
95 
96 	va_start(ap, fmt);
97 	(void) fprintf(stderr, "%s: ", cmdname);
98 	(void) vfprintf(stderr, fmt, ap);
99 	va_end(ap);
100 	(void) fprintf(stderr, "\n");
101 
102 	exit(1);
103 }
104 
105 /* ARGSUSED */
106 static int
space_delta_cb(dmu_object_type_t bonustype,void * data,uint64_t * userp,uint64_t * groupp)107 space_delta_cb(dmu_object_type_t bonustype, void *data,
108     uint64_t *userp, uint64_t *groupp)
109 {
110 	/*
111 	 * Is it a valid type of object to track?
112 	 */
113 	if (bonustype != DMU_OT_ZNODE && bonustype != DMU_OT_SA)
114 		return (ENOENT);
115 	(void) fprintf(stderr, "modifying object that needs user accounting");
116 	abort();
117 	/* NOTREACHED */
118 }
119 
120 /*
121  * Target is the dataset whose pool we want to open.
122  */
123 static void
import_pool(const char * target,boolean_t readonly)124 import_pool(const char *target, boolean_t readonly)
125 {
126 	nvlist_t *config;
127 	nvlist_t *pools;
128 	int error;
129 	char *sepp;
130 	spa_t *spa;
131 	nvpair_t *elem;
132 	nvlist_t *props;
133 	const char *name;
134 
135 	kernel_init(readonly ? FREAD : (FREAD | FWRITE));
136 	g_zfs = libzfs_init();
137 	ASSERT(g_zfs != NULL);
138 
139 	dmu_objset_register_type(DMU_OST_ZFS, space_delta_cb);
140 
141 	g_readonly = readonly;
142 
143 	/*
144 	 * If we only want readonly access, it's OK if we find
145 	 * a potentially-active (ie, imported into the kernel) pool from the
146 	 * default cachefile.
147 	 */
148 	if (readonly && spa_open(target, &spa, FTAG) == 0) {
149 		spa_close(spa, FTAG);
150 		return;
151 	}
152 
153 	g_importargs.unique = B_TRUE;
154 	g_importargs.can_be_active = readonly;
155 	g_pool = strdup(target);
156 	if ((sepp = strpbrk(g_pool, "/@")) != NULL)
157 		*sepp = '\0';
158 	g_importargs.poolname = g_pool;
159 	pools = zpool_search_import(g_zfs, &g_importargs);
160 
161 	if (nvlist_empty(pools)) {
162 		if (!g_importargs.can_be_active) {
163 			g_importargs.can_be_active = B_TRUE;
164 			if (zpool_search_import(g_zfs, &g_importargs) != NULL ||
165 			    spa_open(target, &spa, FTAG) == 0) {
166 				fatal(spa, FTAG, "cannot import '%s': pool is "
167 				    "active; run " "\"zpool export %s\" "
168 				    "first\n", g_pool, g_pool);
169 			}
170 		}
171 
172 		fatal(NULL, FTAG, "cannot import '%s': no such pool "
173 		    "available\n", g_pool);
174 	}
175 
176 	elem = nvlist_next_nvpair(pools, NULL);
177 	name = nvpair_name(elem);
178 	verify(nvpair_value_nvlist(elem, &config) == 0);
179 
180 	props = NULL;
181 	if (readonly) {
182 		verify(nvlist_alloc(&props, NV_UNIQUE_NAME, 0) == 0);
183 		verify(nvlist_add_uint64(props,
184 		    zpool_prop_to_name(ZPOOL_PROP_READONLY), 1) == 0);
185 	}
186 
187 	zfeature_checks_disable = B_TRUE;
188 	error = spa_import(name, config, props, ZFS_IMPORT_NORMAL);
189 	zfeature_checks_disable = B_FALSE;
190 	if (error == EEXIST)
191 		error = 0;
192 
193 	if (error)
194 		fatal(NULL, FTAG, "can't import '%s': %s", name,
195 		    strerror(error));
196 }
197 
198 static void
zhack_spa_open(const char * target,boolean_t readonly,void * tag,spa_t ** spa)199 zhack_spa_open(const char *target, boolean_t readonly, void *tag, spa_t **spa)
200 {
201 	int err;
202 
203 	import_pool(target, readonly);
204 
205 	zfeature_checks_disable = B_TRUE;
206 	err = spa_open(target, spa, tag);
207 	zfeature_checks_disable = B_FALSE;
208 
209 	if (err != 0)
210 		fatal(*spa, FTAG, "cannot open '%s': %s", target,
211 		    strerror(err));
212 	if (spa_version(*spa) < SPA_VERSION_FEATURES) {
213 		fatal(*spa, FTAG, "'%s' has version %d, features not enabled",
214 		    target, (int)spa_version(*spa));
215 	}
216 }
217 
218 static void
dump_obj(objset_t * os,uint64_t obj,const char * name)219 dump_obj(objset_t *os, uint64_t obj, const char *name)
220 {
221 	zap_cursor_t zc;
222 	zap_attribute_t za;
223 
224 	(void) printf("%s_obj:\n", name);
225 
226 	for (zap_cursor_init(&zc, os, obj);
227 	    zap_cursor_retrieve(&zc, &za) == 0;
228 	    zap_cursor_advance(&zc)) {
229 		if (za.za_integer_length == 8) {
230 			ASSERT(za.za_num_integers == 1);
231 			(void) printf("\t%s = %llu\n",
232 			    za.za_name, (u_longlong_t)za.za_first_integer);
233 		} else {
234 			ASSERT(za.za_integer_length == 1);
235 			char val[1024];
236 			VERIFY(zap_lookup(os, obj, za.za_name,
237 			    1, sizeof (val), val) == 0);
238 			(void) printf("\t%s = %s\n", za.za_name, val);
239 		}
240 	}
241 	zap_cursor_fini(&zc);
242 }
243 
244 static void
dump_mos(spa_t * spa)245 dump_mos(spa_t *spa)
246 {
247 	nvlist_t *nv = spa->spa_label_features;
248 
249 	(void) printf("label config:\n");
250 	for (nvpair_t *pair = nvlist_next_nvpair(nv, NULL);
251 	    pair != NULL;
252 	    pair = nvlist_next_nvpair(nv, pair)) {
253 		(void) printf("\t%s\n", nvpair_name(pair));
254 	}
255 }
256 
257 static void
zhack_do_feature_stat(int argc,char ** argv)258 zhack_do_feature_stat(int argc, char **argv)
259 {
260 	spa_t *spa;
261 	objset_t *os;
262 	char *target;
263 
264 	argc--;
265 	argv++;
266 
267 	if (argc < 1) {
268 		(void) fprintf(stderr, "error: missing pool name\n");
269 		usage();
270 	}
271 	target = argv[0];
272 
273 	zhack_spa_open(target, B_TRUE, FTAG, &spa);
274 	os = spa->spa_meta_objset;
275 
276 	dump_obj(os, spa->spa_feat_for_read_obj, "for_read");
277 	dump_obj(os, spa->spa_feat_for_write_obj, "for_write");
278 	dump_obj(os, spa->spa_feat_desc_obj, "descriptions");
279 	if (spa_feature_is_active(spa, SPA_FEATURE_ENABLED_TXG)) {
280 		dump_obj(os, spa->spa_feat_enabled_txg_obj, "enabled_txg");
281 	}
282 	dump_mos(spa);
283 
284 	spa_close(spa, FTAG);
285 }
286 
287 static void
zhack_feature_enable_sync(void * arg,dmu_tx_t * tx)288 zhack_feature_enable_sync(void *arg, dmu_tx_t *tx)
289 {
290 	spa_t *spa = dmu_tx_pool(tx)->dp_spa;
291 	zfeature_info_t *feature = arg;
292 
293 	feature_enable_sync(spa, feature, tx);
294 
295 	spa_history_log_internal(spa, "zhack enable feature", tx,
296 	    "guid=%s flags=%x",
297 	    feature->fi_guid, feature->fi_flags);
298 }
299 
300 static void
zhack_do_feature_enable(int argc,char ** argv)301 zhack_do_feature_enable(int argc, char **argv)
302 {
303 	char c;
304 	char *desc, *target;
305 	spa_t *spa;
306 	objset_t *mos;
307 	zfeature_info_t feature;
308 	spa_feature_t nodeps[] = { SPA_FEATURE_NONE };
309 
310 	/*
311 	 * Features are not added to the pool's label until their refcounts
312 	 * are incremented, so fi_mos can just be left as false for now.
313 	 */
314 	desc = NULL;
315 	feature.fi_uname = "zhack";
316 	feature.fi_flags = 0;
317 	feature.fi_depends = nodeps;
318 	feature.fi_feature = SPA_FEATURE_NONE;
319 
320 	optind = 1;
321 	while ((c = getopt(argc, argv, "rmd:")) != -1) {
322 		switch (c) {
323 		case 'r':
324 			feature.fi_flags |= ZFEATURE_FLAG_READONLY_COMPAT;
325 			break;
326 		case 'd':
327 			desc = strdup(optarg);
328 			break;
329 		default:
330 			usage();
331 			break;
332 		}
333 	}
334 
335 	if (desc == NULL)
336 		desc = strdup("zhack injected");
337 	feature.fi_desc = desc;
338 
339 	argc -= optind;
340 	argv += optind;
341 
342 	if (argc < 2) {
343 		(void) fprintf(stderr, "error: missing feature or pool name\n");
344 		usage();
345 	}
346 	target = argv[0];
347 	feature.fi_guid = argv[1];
348 
349 	if (!zfeature_is_valid_guid(feature.fi_guid))
350 		fatal(NULL, FTAG, "invalid feature guid: %s", feature.fi_guid);
351 
352 	zhack_spa_open(target, B_FALSE, FTAG, &spa);
353 	mos = spa->spa_meta_objset;
354 
355 	if (zfeature_is_supported(feature.fi_guid))
356 		fatal(spa, FTAG, "'%s' is a real feature, will not enable");
357 	if (0 == zap_contains(mos, spa->spa_feat_desc_obj, feature.fi_guid))
358 		fatal(spa, FTAG, "feature already enabled: %s",
359 		    feature.fi_guid);
360 
361 	VERIFY0(dsl_sync_task(spa_name(spa), NULL,
362 	    zhack_feature_enable_sync, &feature, 5, ZFS_SPACE_CHECK_NORMAL));
363 
364 	spa_close(spa, FTAG);
365 
366 	free(desc);
367 }
368 
369 static void
feature_incr_sync(void * arg,dmu_tx_t * tx)370 feature_incr_sync(void *arg, dmu_tx_t *tx)
371 {
372 	spa_t *spa = dmu_tx_pool(tx)->dp_spa;
373 	zfeature_info_t *feature = arg;
374 	uint64_t refcount;
375 
376 	VERIFY0(feature_get_refcount_from_disk(spa, feature, &refcount));
377 	feature_sync(spa, feature, refcount + 1, tx);
378 	spa_history_log_internal(spa, "zhack feature incr", tx,
379 	    "guid=%s", feature->fi_guid);
380 }
381 
382 static void
feature_decr_sync(void * arg,dmu_tx_t * tx)383 feature_decr_sync(void *arg, dmu_tx_t *tx)
384 {
385 	spa_t *spa = dmu_tx_pool(tx)->dp_spa;
386 	zfeature_info_t *feature = arg;
387 	uint64_t refcount;
388 
389 	VERIFY0(feature_get_refcount_from_disk(spa, feature, &refcount));
390 	feature_sync(spa, feature, refcount - 1, tx);
391 	spa_history_log_internal(spa, "zhack feature decr", tx,
392 	    "guid=%s", feature->fi_guid);
393 }
394 
395 static void
zhack_do_feature_ref(int argc,char ** argv)396 zhack_do_feature_ref(int argc, char **argv)
397 {
398 	char c;
399 	char *target;
400 	boolean_t decr = B_FALSE;
401 	spa_t *spa;
402 	objset_t *mos;
403 	zfeature_info_t feature;
404 	spa_feature_t nodeps[] = { SPA_FEATURE_NONE };
405 
406 	/*
407 	 * fi_desc does not matter here because it was written to disk
408 	 * when the feature was enabled, but we need to properly set the
409 	 * feature for read or write based on the information we read off
410 	 * disk later.
411 	 */
412 	feature.fi_uname = "zhack";
413 	feature.fi_flags = 0;
414 	feature.fi_desc = NULL;
415 	feature.fi_depends = nodeps;
416 	feature.fi_feature = SPA_FEATURE_NONE;
417 
418 	optind = 1;
419 	while ((c = getopt(argc, argv, "md")) != -1) {
420 		switch (c) {
421 		case 'm':
422 			feature.fi_flags |= ZFEATURE_FLAG_MOS;
423 			break;
424 		case 'd':
425 			decr = B_TRUE;
426 			break;
427 		default:
428 			usage();
429 			break;
430 		}
431 	}
432 	argc -= optind;
433 	argv += optind;
434 
435 	if (argc < 2) {
436 		(void) fprintf(stderr, "error: missing feature or pool name\n");
437 		usage();
438 	}
439 	target = argv[0];
440 	feature.fi_guid = argv[1];
441 
442 	if (!zfeature_is_valid_guid(feature.fi_guid))
443 		fatal(NULL, FTAG, "invalid feature guid: %s", feature.fi_guid);
444 
445 	zhack_spa_open(target, B_FALSE, FTAG, &spa);
446 	mos = spa->spa_meta_objset;
447 
448 	if (zfeature_is_supported(feature.fi_guid)) {
449 		fatal(spa, FTAG,
450 		    "'%s' is a real feature, will not change refcount");
451 	}
452 
453 	if (0 == zap_contains(mos, spa->spa_feat_for_read_obj,
454 	    feature.fi_guid)) {
455 		feature.fi_flags &= ~ZFEATURE_FLAG_READONLY_COMPAT;
456 	} else if (0 == zap_contains(mos, spa->spa_feat_for_write_obj,
457 	    feature.fi_guid)) {
458 		feature.fi_flags |= ZFEATURE_FLAG_READONLY_COMPAT;
459 	} else {
460 		fatal(spa, FTAG, "feature is not enabled: %s", feature.fi_guid);
461 	}
462 
463 	if (decr) {
464 		uint64_t count;
465 		if (feature_get_refcount_from_disk(spa, &feature,
466 		    &count) == 0 && count != 0) {
467 			fatal(spa, FTAG, "feature refcount already 0: %s",
468 			    feature.fi_guid);
469 		}
470 	}
471 
472 	VERIFY0(dsl_sync_task(spa_name(spa), NULL,
473 	    decr ? feature_decr_sync : feature_incr_sync, &feature,
474 	    5, ZFS_SPACE_CHECK_NORMAL));
475 
476 	spa_close(spa, FTAG);
477 }
478 
479 static int
zhack_do_feature(int argc,char ** argv)480 zhack_do_feature(int argc, char **argv)
481 {
482 	char *subcommand;
483 
484 	argc--;
485 	argv++;
486 	if (argc == 0) {
487 		(void) fprintf(stderr,
488 		    "error: no feature operation specified\n");
489 		usage();
490 	}
491 
492 	subcommand = argv[0];
493 	if (strcmp(subcommand, "stat") == 0) {
494 		zhack_do_feature_stat(argc, argv);
495 	} else if (strcmp(subcommand, "enable") == 0) {
496 		zhack_do_feature_enable(argc, argv);
497 	} else if (strcmp(subcommand, "ref") == 0) {
498 		zhack_do_feature_ref(argc, argv);
499 	} else {
500 		(void) fprintf(stderr, "error: unknown subcommand: %s\n",
501 		    subcommand);
502 		usage();
503 	}
504 
505 	return (0);
506 }
507 
508 #define	MAX_NUM_PATHS 1024
509 
510 int
main(int argc,char ** argv)511 main(int argc, char **argv)
512 {
513 	extern void zfs_prop_init(void);
514 
515 	char *path[MAX_NUM_PATHS];
516 	const char *subcommand;
517 	int rv = 0;
518 	char c;
519 
520 	g_importargs.path = path;
521 
522 	dprintf_setup(&argc, argv);
523 	zfs_prop_init();
524 
525 	while ((c = getopt(argc, argv, "c:d:")) != -1) {
526 		switch (c) {
527 		case 'c':
528 			g_importargs.cachefile = optarg;
529 			break;
530 		case 'd':
531 			assert(g_importargs.paths < MAX_NUM_PATHS);
532 			g_importargs.path[g_importargs.paths++] = optarg;
533 			break;
534 		default:
535 			usage();
536 			break;
537 		}
538 	}
539 
540 	argc -= optind;
541 	argv += optind;
542 	optind = 1;
543 
544 	if (argc == 0) {
545 		(void) fprintf(stderr, "error: no command specified\n");
546 		usage();
547 	}
548 
549 	subcommand = argv[0];
550 
551 	if (strcmp(subcommand, "feature") == 0) {
552 		rv = zhack_do_feature(argc, argv);
553 	} else {
554 		(void) fprintf(stderr, "error: unknown subcommand: %s\n",
555 		    subcommand);
556 		usage();
557 	}
558 
559 	if (!g_readonly && spa_export(g_pool, NULL, B_TRUE, B_FALSE) != 0) {
560 		fatal(NULL, FTAG, "pool export failed; "
561 		    "changes may not be committed to disk\n");
562 	}
563 
564 	libzfs_fini(g_zfs);
565 	kernel_fini();
566 
567 	return (rv);
568 }
569