xref: /titanic_50/usr/src/cmd/zhack/zhack.c (revision 7b07063d906859b2be1e88791f801b3c96e432f6)
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 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 	if (spa_feature_is_active(spa, SPA_FEATURE_ENABLED_TXG)) {
281 		dump_obj(os, spa->spa_feat_enabled_txg_obj, "enabled_txg");
282 	}
283 	dump_mos(spa);
284 
285 	spa_close(spa, FTAG);
286 }
287 
288 static void
289 zhack_feature_enable_sync(void *arg, dmu_tx_t *tx)
290 {
291 	spa_t *spa = dmu_tx_pool(tx)->dp_spa;
292 	zfeature_info_t *feature = arg;
293 
294 	feature_enable_sync(spa, feature, tx);
295 
296 	spa_history_log_internal(spa, "zhack enable feature", tx,
297 	    "guid=%s flags=%x",
298 	    feature->fi_guid, feature->fi_flags);
299 }
300 
301 static void
302 zhack_do_feature_enable(int argc, char **argv)
303 {
304 	char c;
305 	char *desc, *target;
306 	spa_t *spa;
307 	objset_t *mos;
308 	zfeature_info_t feature;
309 	spa_feature_t nodeps[] = { SPA_FEATURE_NONE };
310 
311 	/*
312 	 * Features are not added to the pool's label until their refcounts
313 	 * are incremented, so fi_mos can just be left as false for now.
314 	 */
315 	desc = NULL;
316 	feature.fi_uname = "zhack";
317 	feature.fi_flags = 0;
318 	feature.fi_depends = nodeps;
319 	feature.fi_feature = SPA_FEATURE_NONE;
320 
321 	optind = 1;
322 	while ((c = getopt(argc, argv, "rmd:")) != -1) {
323 		switch (c) {
324 		case 'r':
325 			feature.fi_flags |= ZFEATURE_FLAG_READONLY_COMPAT;
326 			break;
327 		case 'd':
328 			desc = strdup(optarg);
329 			break;
330 		default:
331 			usage();
332 			break;
333 		}
334 	}
335 
336 	if (desc == NULL)
337 		desc = strdup("zhack injected");
338 	feature.fi_desc = desc;
339 
340 	argc -= optind;
341 	argv += optind;
342 
343 	if (argc < 2) {
344 		(void) fprintf(stderr, "error: missing feature or pool name\n");
345 		usage();
346 	}
347 	target = argv[0];
348 	feature.fi_guid = argv[1];
349 
350 	if (!zfeature_is_valid_guid(feature.fi_guid))
351 		fatal(NULL, FTAG, "invalid feature guid: %s", feature.fi_guid);
352 
353 	zhack_spa_open(target, B_FALSE, FTAG, &spa);
354 	mos = spa->spa_meta_objset;
355 
356 	if (zfeature_is_supported(feature.fi_guid))
357 		fatal(spa, FTAG, "'%s' is a real feature, will not enable");
358 	if (0 == zap_contains(mos, spa->spa_feat_desc_obj, feature.fi_guid))
359 		fatal(spa, FTAG, "feature already enabled: %s",
360 		    feature.fi_guid);
361 
362 	VERIFY0(dsl_sync_task(spa_name(spa), NULL,
363 	    zhack_feature_enable_sync, &feature, 5, ZFS_SPACE_CHECK_NORMAL));
364 
365 	spa_close(spa, FTAG);
366 
367 	free(desc);
368 }
369 
370 static void
371 feature_incr_sync(void *arg, dmu_tx_t *tx)
372 {
373 	spa_t *spa = dmu_tx_pool(tx)->dp_spa;
374 	zfeature_info_t *feature = arg;
375 	uint64_t refcount;
376 
377 	VERIFY0(feature_get_refcount_from_disk(spa, feature, &refcount));
378 	feature_sync(spa, feature, refcount + 1, tx);
379 	spa_history_log_internal(spa, "zhack feature incr", tx,
380 	    "guid=%s", feature->fi_guid);
381 }
382 
383 static void
384 feature_decr_sync(void *arg, dmu_tx_t *tx)
385 {
386 	spa_t *spa = dmu_tx_pool(tx)->dp_spa;
387 	zfeature_info_t *feature = arg;
388 	uint64_t refcount;
389 
390 	VERIFY0(feature_get_refcount_from_disk(spa, feature, &refcount));
391 	feature_sync(spa, feature, refcount - 1, tx);
392 	spa_history_log_internal(spa, "zhack feature decr", tx,
393 	    "guid=%s", feature->fi_guid);
394 }
395 
396 static void
397 zhack_do_feature_ref(int argc, char **argv)
398 {
399 	char c;
400 	char *target;
401 	boolean_t decr = B_FALSE;
402 	spa_t *spa;
403 	objset_t *mos;
404 	zfeature_info_t feature;
405 	spa_feature_t nodeps[] = { SPA_FEATURE_NONE };
406 
407 	/*
408 	 * fi_desc does not matter here because it was written to disk
409 	 * when the feature was enabled, but we need to properly set the
410 	 * feature for read or write based on the information we read off
411 	 * disk later.
412 	 */
413 	feature.fi_uname = "zhack";
414 	feature.fi_flags = 0;
415 	feature.fi_desc = NULL;
416 	feature.fi_depends = nodeps;
417 	feature.fi_feature = SPA_FEATURE_NONE;
418 
419 	optind = 1;
420 	while ((c = getopt(argc, argv, "md")) != -1) {
421 		switch (c) {
422 		case 'm':
423 			feature.fi_flags |= ZFEATURE_FLAG_MOS;
424 			break;
425 		case 'd':
426 			decr = B_TRUE;
427 			break;
428 		default:
429 			usage();
430 			break;
431 		}
432 	}
433 	argc -= optind;
434 	argv += optind;
435 
436 	if (argc < 2) {
437 		(void) fprintf(stderr, "error: missing feature or pool name\n");
438 		usage();
439 	}
440 	target = argv[0];
441 	feature.fi_guid = argv[1];
442 
443 	if (!zfeature_is_valid_guid(feature.fi_guid))
444 		fatal(NULL, FTAG, "invalid feature guid: %s", feature.fi_guid);
445 
446 	zhack_spa_open(target, B_FALSE, FTAG, &spa);
447 	mos = spa->spa_meta_objset;
448 
449 	if (zfeature_is_supported(feature.fi_guid)) {
450 		fatal(spa, FTAG,
451 		    "'%s' is a real feature, will not change refcount");
452 	}
453 
454 	if (0 == zap_contains(mos, spa->spa_feat_for_read_obj,
455 	    feature.fi_guid)) {
456 		feature.fi_flags &= ~ZFEATURE_FLAG_READONLY_COMPAT;
457 	} else if (0 == zap_contains(mos, spa->spa_feat_for_write_obj,
458 	    feature.fi_guid)) {
459 		feature.fi_flags |= ZFEATURE_FLAG_READONLY_COMPAT;
460 	} else {
461 		fatal(spa, FTAG, "feature is not enabled: %s", feature.fi_guid);
462 	}
463 
464 	if (decr) {
465 		uint64_t count;
466 		if (feature_get_refcount_from_disk(spa, &feature,
467 		    &count) == 0 && count != 0) {
468 			fatal(spa, FTAG, "feature refcount already 0: %s",
469 			    feature.fi_guid);
470 		}
471 	}
472 
473 	VERIFY0(dsl_sync_task(spa_name(spa), NULL,
474 	    decr ? feature_decr_sync : feature_incr_sync, &feature,
475 	    5, ZFS_SPACE_CHECK_NORMAL));
476 
477 	spa_close(spa, FTAG);
478 }
479 
480 static int
481 zhack_do_feature(int argc, char **argv)
482 {
483 	char *subcommand;
484 
485 	argc--;
486 	argv++;
487 	if (argc == 0) {
488 		(void) fprintf(stderr,
489 		    "error: no feature operation specified\n");
490 		usage();
491 	}
492 
493 	subcommand = argv[0];
494 	if (strcmp(subcommand, "stat") == 0) {
495 		zhack_do_feature_stat(argc, argv);
496 	} else if (strcmp(subcommand, "enable") == 0) {
497 		zhack_do_feature_enable(argc, argv);
498 	} else if (strcmp(subcommand, "ref") == 0) {
499 		zhack_do_feature_ref(argc, argv);
500 	} else {
501 		(void) fprintf(stderr, "error: unknown subcommand: %s\n",
502 		    subcommand);
503 		usage();
504 	}
505 
506 	return (0);
507 }
508 
509 #define	MAX_NUM_PATHS 1024
510 
511 int
512 main(int argc, char **argv)
513 {
514 	extern void zfs_prop_init(void);
515 
516 	char *path[MAX_NUM_PATHS];
517 	const char *subcommand;
518 	int rv = 0;
519 	char c;
520 
521 	g_importargs.path = path;
522 
523 	dprintf_setup(&argc, argv);
524 	zfs_prop_init();
525 
526 	while ((c = getopt(argc, argv, "c:d:")) != -1) {
527 		switch (c) {
528 		case 'c':
529 			g_importargs.cachefile = optarg;
530 			break;
531 		case 'd':
532 			assert(g_importargs.paths < MAX_NUM_PATHS);
533 			g_importargs.path[g_importargs.paths++] = optarg;
534 			break;
535 		default:
536 			usage();
537 			break;
538 		}
539 	}
540 
541 	argc -= optind;
542 	argv += optind;
543 	optind = 1;
544 
545 	if (argc == 0) {
546 		(void) fprintf(stderr, "error: no command specified\n");
547 		usage();
548 	}
549 
550 	subcommand = argv[0];
551 
552 	if (strcmp(subcommand, "feature") == 0) {
553 		rv = zhack_do_feature(argc, argv);
554 	} else {
555 		(void) fprintf(stderr, "error: unknown subcommand: %s\n",
556 		    subcommand);
557 		usage();
558 	}
559 
560 	if (!g_readonly && spa_export(g_pool, NULL, B_TRUE, B_FALSE) != 0) {
561 		fatal(NULL, FTAG, "pool export failed; "
562 		    "changes may not be committed to disk\n");
563 	}
564 
565 	libzfs_fini(g_zfs);
566 	kernel_fini();
567 
568 	return (rv);
569 }
570