xref: /illumos-gate/usr/src/cmd/zhack/zhack.c (revision 2667222682da9a362b1246a1e39cdaf1f38cb56e)
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
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
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
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
124 zhack_import(char *target, boolean_t readonly)
125 {
126 	nvlist_t *config;
127 	nvlist_t *props;
128 	int error;
129 
130 	kernel_init(readonly ? FREAD : (FREAD | FWRITE));
131 	g_zfs = libzfs_init();
132 	ASSERT(g_zfs != NULL);
133 
134 	dmu_objset_register_type(DMU_OST_ZFS, space_delta_cb);
135 
136 	g_readonly = readonly;
137 	g_importargs.unique = B_TRUE;
138 	g_importargs.can_be_active = readonly;
139 	g_pool = strdup(target);
140 
141 	error = zpool_tryimport(g_zfs, target, &config, &g_importargs);
142 	if (error)
143 		fatal(NULL, FTAG, "cannot import '%s': %s", target,
144 		    libzfs_error_description(g_zfs));
145 
146 	props = NULL;
147 	if (readonly) {
148 		VERIFY(nvlist_alloc(&props, NV_UNIQUE_NAME, 0) == 0);
149 		VERIFY(nvlist_add_uint64(props,
150 		    zpool_prop_to_name(ZPOOL_PROP_READONLY), 1) == 0);
151 	}
152 
153 	zfeature_checks_disable = B_TRUE;
154 	error = spa_import(target, config, props,
155 	    (readonly ?  ZFS_IMPORT_SKIP_MMP : ZFS_IMPORT_NORMAL));
156 	zfeature_checks_disable = B_FALSE;
157 	if (error == EEXIST)
158 		error = 0;
159 
160 	if (error)
161 		fatal(NULL, FTAG, "can't import '%s': %s", target,
162 		    strerror(error));
163 }
164 
165 static void
166 zhack_spa_open(char *target, boolean_t readonly, void *tag, spa_t **spa)
167 {
168 	int err;
169 
170 	zhack_import(target, readonly);
171 
172 	zfeature_checks_disable = B_TRUE;
173 	err = spa_open(target, spa, tag);
174 	zfeature_checks_disable = B_FALSE;
175 
176 	if (err != 0)
177 		fatal(*spa, FTAG, "cannot open '%s': %s", target,
178 		    strerror(err));
179 	if (spa_version(*spa) < SPA_VERSION_FEATURES) {
180 		fatal(*spa, FTAG, "'%s' has version %d, features not enabled",
181 		    target, (int)spa_version(*spa));
182 	}
183 }
184 
185 static void
186 dump_obj(objset_t *os, uint64_t obj, const char *name)
187 {
188 	zap_cursor_t zc;
189 	zap_attribute_t za;
190 
191 	(void) printf("%s_obj:\n", name);
192 
193 	for (zap_cursor_init(&zc, os, obj);
194 	    zap_cursor_retrieve(&zc, &za) == 0;
195 	    zap_cursor_advance(&zc)) {
196 		if (za.za_integer_length == 8) {
197 			ASSERT(za.za_num_integers == 1);
198 			(void) printf("\t%s = %llu\n",
199 			    za.za_name, (u_longlong_t)za.za_first_integer);
200 		} else {
201 			ASSERT(za.za_integer_length == 1);
202 			char val[1024];
203 			VERIFY(zap_lookup(os, obj, za.za_name,
204 			    1, sizeof (val), val) == 0);
205 			(void) printf("\t%s = %s\n", za.za_name, val);
206 		}
207 	}
208 	zap_cursor_fini(&zc);
209 }
210 
211 static void
212 dump_mos(spa_t *spa)
213 {
214 	nvlist_t *nv = spa->spa_label_features;
215 
216 	(void) printf("label config:\n");
217 	for (nvpair_t *pair = nvlist_next_nvpair(nv, NULL);
218 	    pair != NULL;
219 	    pair = nvlist_next_nvpair(nv, pair)) {
220 		(void) printf("\t%s\n", nvpair_name(pair));
221 	}
222 }
223 
224 static void
225 zhack_do_feature_stat(int argc, char **argv)
226 {
227 	spa_t *spa;
228 	objset_t *os;
229 	char *target;
230 
231 	argc--;
232 	argv++;
233 
234 	if (argc < 1) {
235 		(void) fprintf(stderr, "error: missing pool name\n");
236 		usage();
237 	}
238 	target = argv[0];
239 
240 	zhack_spa_open(target, B_TRUE, FTAG, &spa);
241 	os = spa->spa_meta_objset;
242 
243 	dump_obj(os, spa->spa_feat_for_read_obj, "for_read");
244 	dump_obj(os, spa->spa_feat_for_write_obj, "for_write");
245 	dump_obj(os, spa->spa_feat_desc_obj, "descriptions");
246 	if (spa_feature_is_active(spa, SPA_FEATURE_ENABLED_TXG)) {
247 		dump_obj(os, spa->spa_feat_enabled_txg_obj, "enabled_txg");
248 	}
249 	dump_mos(spa);
250 
251 	spa_close(spa, FTAG);
252 }
253 
254 static void
255 zhack_feature_enable_sync(void *arg, dmu_tx_t *tx)
256 {
257 	spa_t *spa = dmu_tx_pool(tx)->dp_spa;
258 	zfeature_info_t *feature = arg;
259 
260 	feature_enable_sync(spa, feature, tx);
261 
262 	spa_history_log_internal(spa, "zhack enable feature", tx,
263 	    "guid=%s flags=%x",
264 	    feature->fi_guid, feature->fi_flags);
265 }
266 
267 static void
268 zhack_do_feature_enable(int argc, char **argv)
269 {
270 	char c;
271 	char *desc, *target;
272 	spa_t *spa;
273 	objset_t *mos;
274 	zfeature_info_t feature;
275 	spa_feature_t nodeps[] = { SPA_FEATURE_NONE };
276 
277 	/*
278 	 * Features are not added to the pool's label until their refcounts
279 	 * are incremented, so fi_mos can just be left as false for now.
280 	 */
281 	desc = NULL;
282 	feature.fi_uname = "zhack";
283 	feature.fi_flags = 0;
284 	feature.fi_depends = nodeps;
285 	feature.fi_feature = SPA_FEATURE_NONE;
286 
287 	optind = 1;
288 	while ((c = getopt(argc, argv, "rmd:")) != -1) {
289 		switch (c) {
290 		case 'r':
291 			feature.fi_flags |= ZFEATURE_FLAG_READONLY_COMPAT;
292 			break;
293 		case 'd':
294 			desc = strdup(optarg);
295 			break;
296 		default:
297 			usage();
298 			break;
299 		}
300 	}
301 
302 	if (desc == NULL)
303 		desc = strdup("zhack injected");
304 	feature.fi_desc = desc;
305 
306 	argc -= optind;
307 	argv += optind;
308 
309 	if (argc < 2) {
310 		(void) fprintf(stderr, "error: missing feature or pool name\n");
311 		usage();
312 	}
313 	target = argv[0];
314 	feature.fi_guid = argv[1];
315 
316 	if (!zfeature_is_valid_guid(feature.fi_guid))
317 		fatal(NULL, FTAG, "invalid feature guid: %s", feature.fi_guid);
318 
319 	zhack_spa_open(target, B_FALSE, FTAG, &spa);
320 	mos = spa->spa_meta_objset;
321 
322 	if (zfeature_is_supported(feature.fi_guid))
323 		fatal(spa, FTAG, "'%s' is a real feature, will not enable");
324 	if (0 == zap_contains(mos, spa->spa_feat_desc_obj, feature.fi_guid))
325 		fatal(spa, FTAG, "feature already enabled: %s",
326 		    feature.fi_guid);
327 
328 	VERIFY0(dsl_sync_task(spa_name(spa), NULL,
329 	    zhack_feature_enable_sync, &feature, 5, ZFS_SPACE_CHECK_NORMAL));
330 
331 	spa_close(spa, FTAG);
332 
333 	free(desc);
334 }
335 
336 static void
337 feature_incr_sync(void *arg, dmu_tx_t *tx)
338 {
339 	spa_t *spa = dmu_tx_pool(tx)->dp_spa;
340 	zfeature_info_t *feature = arg;
341 	uint64_t refcount;
342 
343 	VERIFY0(feature_get_refcount_from_disk(spa, feature, &refcount));
344 	feature_sync(spa, feature, refcount + 1, tx);
345 	spa_history_log_internal(spa, "zhack feature incr", tx,
346 	    "guid=%s", feature->fi_guid);
347 }
348 
349 static void
350 feature_decr_sync(void *arg, dmu_tx_t *tx)
351 {
352 	spa_t *spa = dmu_tx_pool(tx)->dp_spa;
353 	zfeature_info_t *feature = arg;
354 	uint64_t refcount;
355 
356 	VERIFY0(feature_get_refcount_from_disk(spa, feature, &refcount));
357 	feature_sync(spa, feature, refcount - 1, tx);
358 	spa_history_log_internal(spa, "zhack feature decr", tx,
359 	    "guid=%s", feature->fi_guid);
360 }
361 
362 static void
363 zhack_do_feature_ref(int argc, char **argv)
364 {
365 	char c;
366 	char *target;
367 	boolean_t decr = B_FALSE;
368 	spa_t *spa;
369 	objset_t *mos;
370 	zfeature_info_t feature;
371 	spa_feature_t nodeps[] = { SPA_FEATURE_NONE };
372 
373 	/*
374 	 * fi_desc does not matter here because it was written to disk
375 	 * when the feature was enabled, but we need to properly set the
376 	 * feature for read or write based on the information we read off
377 	 * disk later.
378 	 */
379 	feature.fi_uname = "zhack";
380 	feature.fi_flags = 0;
381 	feature.fi_desc = NULL;
382 	feature.fi_depends = nodeps;
383 	feature.fi_feature = SPA_FEATURE_NONE;
384 
385 	optind = 1;
386 	while ((c = getopt(argc, argv, "md")) != -1) {
387 		switch (c) {
388 		case 'm':
389 			feature.fi_flags |= ZFEATURE_FLAG_MOS;
390 			break;
391 		case 'd':
392 			decr = B_TRUE;
393 			break;
394 		default:
395 			usage();
396 			break;
397 		}
398 	}
399 	argc -= optind;
400 	argv += optind;
401 
402 	if (argc < 2) {
403 		(void) fprintf(stderr, "error: missing feature or pool name\n");
404 		usage();
405 	}
406 	target = argv[0];
407 	feature.fi_guid = argv[1];
408 
409 	if (!zfeature_is_valid_guid(feature.fi_guid))
410 		fatal(NULL, FTAG, "invalid feature guid: %s", feature.fi_guid);
411 
412 	zhack_spa_open(target, B_FALSE, FTAG, &spa);
413 	mos = spa->spa_meta_objset;
414 
415 	if (zfeature_is_supported(feature.fi_guid)) {
416 		fatal(spa, FTAG,
417 		    "'%s' is a real feature, will not change refcount");
418 	}
419 
420 	if (0 == zap_contains(mos, spa->spa_feat_for_read_obj,
421 	    feature.fi_guid)) {
422 		feature.fi_flags &= ~ZFEATURE_FLAG_READONLY_COMPAT;
423 	} else if (0 == zap_contains(mos, spa->spa_feat_for_write_obj,
424 	    feature.fi_guid)) {
425 		feature.fi_flags |= ZFEATURE_FLAG_READONLY_COMPAT;
426 	} else {
427 		fatal(spa, FTAG, "feature is not enabled: %s", feature.fi_guid);
428 	}
429 
430 	if (decr) {
431 		uint64_t count;
432 		if (feature_get_refcount_from_disk(spa, &feature,
433 		    &count) == 0 && count != 0) {
434 			fatal(spa, FTAG, "feature refcount already 0: %s",
435 			    feature.fi_guid);
436 		}
437 	}
438 
439 	VERIFY0(dsl_sync_task(spa_name(spa), NULL,
440 	    decr ? feature_decr_sync : feature_incr_sync, &feature,
441 	    5, ZFS_SPACE_CHECK_NORMAL));
442 
443 	spa_close(spa, FTAG);
444 }
445 
446 static int
447 zhack_do_feature(int argc, char **argv)
448 {
449 	char *subcommand;
450 
451 	argc--;
452 	argv++;
453 	if (argc == 0) {
454 		(void) fprintf(stderr,
455 		    "error: no feature operation specified\n");
456 		usage();
457 	}
458 
459 	subcommand = argv[0];
460 	if (strcmp(subcommand, "stat") == 0) {
461 		zhack_do_feature_stat(argc, argv);
462 	} else if (strcmp(subcommand, "enable") == 0) {
463 		zhack_do_feature_enable(argc, argv);
464 	} else if (strcmp(subcommand, "ref") == 0) {
465 		zhack_do_feature_ref(argc, argv);
466 	} else {
467 		(void) fprintf(stderr, "error: unknown subcommand: %s\n",
468 		    subcommand);
469 		usage();
470 	}
471 
472 	return (0);
473 }
474 
475 #define	MAX_NUM_PATHS 1024
476 
477 int
478 main(int argc, char **argv)
479 {
480 	extern void zfs_prop_init(void);
481 
482 	char *path[MAX_NUM_PATHS];
483 	const char *subcommand;
484 	int rv = 0;
485 	char c;
486 
487 	g_importargs.path = path;
488 
489 	dprintf_setup(&argc, argv);
490 	zfs_prop_init();
491 
492 	while ((c = getopt(argc, argv, "c:d:")) != -1) {
493 		switch (c) {
494 		case 'c':
495 			g_importargs.cachefile = optarg;
496 			break;
497 		case 'd':
498 			assert(g_importargs.paths < MAX_NUM_PATHS);
499 			g_importargs.path[g_importargs.paths++] = optarg;
500 			break;
501 		default:
502 			usage();
503 			break;
504 		}
505 	}
506 
507 	argc -= optind;
508 	argv += optind;
509 	optind = 1;
510 
511 	if (argc == 0) {
512 		(void) fprintf(stderr, "error: no command specified\n");
513 		usage();
514 	}
515 
516 	subcommand = argv[0];
517 
518 	if (strcmp(subcommand, "feature") == 0) {
519 		rv = zhack_do_feature(argc, argv);
520 	} else {
521 		(void) fprintf(stderr, "error: unknown subcommand: %s\n",
522 		    subcommand);
523 		usage();
524 	}
525 
526 	if (!g_readonly && spa_export(g_pool, NULL, B_TRUE, B_FALSE) != 0) {
527 		fatal(NULL, FTAG, "pool export failed; "
528 		    "changes may not be committed to disk\n");
529 	}
530 
531 	libzfs_fini(g_zfs);
532 	kernel_fini();
533 
534 	return (rv);
535 }
536