xref: /illumos-gate/usr/src/cmd/zhack/zhack.c (revision a7a845e4bf22fd1b2a284729ccd95c7370a0438c)
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) 2012 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(const char *fmt, ...)
89 {
90 	va_list ap;
91 
92 	va_start(ap, fmt);
93 	(void) fprintf(stderr, "%s: ", cmdname);
94 	(void) vfprintf(stderr, fmt, ap);
95 	va_end(ap);
96 	(void) fprintf(stderr, "\n");
97 
98 	exit(1);
99 }
100 
101 /* ARGSUSED */
102 static int
103 space_delta_cb(dmu_object_type_t bonustype, void *data,
104     uint64_t *userp, uint64_t *groupp)
105 {
106 	/*
107 	 * Is it a valid type of object to track?
108 	 */
109 	if (bonustype != DMU_OT_ZNODE && bonustype != DMU_OT_SA)
110 		return (ENOENT);
111 	(void) fprintf(stderr, "modifying object that needs user accounting");
112 	abort();
113 	/* NOTREACHED */
114 }
115 
116 /*
117  * Target is the dataset whose pool we want to open.
118  */
119 static void
120 import_pool(const char *target, boolean_t readonly)
121 {
122 	nvlist_t *config;
123 	nvlist_t *pools;
124 	int error;
125 	char *sepp;
126 	spa_t *spa;
127 	nvpair_t *elem;
128 	nvlist_t *props;
129 	const char *name;
130 
131 	kernel_init(readonly ? FREAD : (FREAD | FWRITE));
132 	g_zfs = libzfs_init();
133 	ASSERT(g_zfs != NULL);
134 
135 	dmu_objset_register_type(DMU_OST_ZFS, space_delta_cb);
136 
137 	g_readonly = readonly;
138 
139 	/*
140 	 * If we only want readonly access, it's OK if we find
141 	 * a potentially-active (ie, imported into the kernel) pool from the
142 	 * default cachefile.
143 	 */
144 	if (readonly && spa_open(target, &spa, FTAG) == 0) {
145 		spa_close(spa, FTAG);
146 		return;
147 	}
148 
149 	g_importargs.unique = B_TRUE;
150 	g_importargs.can_be_active = readonly;
151 	g_pool = strdup(target);
152 	if ((sepp = strpbrk(g_pool, "/@")) != NULL)
153 		*sepp = '\0';
154 	g_importargs.poolname = g_pool;
155 	pools = zpool_search_import(g_zfs, &g_importargs);
156 
157 	if (nvlist_empty(pools)) {
158 		if (!g_importargs.can_be_active) {
159 			g_importargs.can_be_active = B_TRUE;
160 			if (zpool_search_import(g_zfs, &g_importargs) != NULL ||
161 			    spa_open(target, &spa, FTAG) == 0) {
162 				fatal("cannot import '%s': pool is active; run "
163 				    "\"zpool export %s\" first\n",
164 				    g_pool, g_pool);
165 			}
166 		}
167 
168 		fatal("cannot import '%s': no such pool available\n", g_pool);
169 	}
170 
171 	elem = nvlist_next_nvpair(pools, NULL);
172 	name = nvpair_name(elem);
173 	verify(nvpair_value_nvlist(elem, &config) == 0);
174 
175 	props = NULL;
176 	if (readonly) {
177 		verify(nvlist_alloc(&props, NV_UNIQUE_NAME, 0) == 0);
178 		verify(nvlist_add_uint64(props,
179 		    zpool_prop_to_name(ZPOOL_PROP_READONLY), 1) == 0);
180 	}
181 
182 	zfeature_checks_disable = B_TRUE;
183 	error = spa_import(name, config, props, ZFS_IMPORT_NORMAL);
184 	zfeature_checks_disable = B_FALSE;
185 	if (error == EEXIST)
186 		error = 0;
187 
188 	if (error)
189 		fatal("can't import '%s': %s", name, strerror(error));
190 }
191 
192 static void
193 zhack_spa_open(const char *target, boolean_t readonly, void *tag, spa_t **spa)
194 {
195 	int err;
196 
197 	import_pool(target, readonly);
198 
199 	zfeature_checks_disable = B_TRUE;
200 	err = spa_open(target, spa, tag);
201 	zfeature_checks_disable = B_FALSE;
202 
203 	if (err != 0)
204 		fatal("cannot open '%s': %s", target, strerror(err));
205 	if (spa_version(*spa) < SPA_VERSION_FEATURES) {
206 		fatal("'%s' has version %d, features not enabled", target,
207 		    (int)spa_version(*spa));
208 	}
209 }
210 
211 static void
212 dump_obj(objset_t *os, uint64_t obj, const char *name)
213 {
214 	zap_cursor_t zc;
215 	zap_attribute_t za;
216 
217 	(void) printf("%s_obj:\n", name);
218 
219 	for (zap_cursor_init(&zc, os, obj);
220 	    zap_cursor_retrieve(&zc, &za) == 0;
221 	    zap_cursor_advance(&zc)) {
222 		if (za.za_integer_length == 8) {
223 			ASSERT(za.za_num_integers == 1);
224 			(void) printf("\t%s = %llu\n",
225 			    za.za_name, (u_longlong_t)za.za_first_integer);
226 		} else {
227 			ASSERT(za.za_integer_length == 1);
228 			char val[1024];
229 			VERIFY(zap_lookup(os, obj, za.za_name,
230 			    1, sizeof (val), val) == 0);
231 			(void) printf("\t%s = %s\n", za.za_name, val);
232 		}
233 	}
234 	zap_cursor_fini(&zc);
235 }
236 
237 static void
238 dump_mos(spa_t *spa)
239 {
240 	nvlist_t *nv = spa->spa_label_features;
241 
242 	(void) printf("label config:\n");
243 	for (nvpair_t *pair = nvlist_next_nvpair(nv, NULL);
244 	    pair != NULL;
245 	    pair = nvlist_next_nvpair(nv, pair)) {
246 		(void) printf("\t%s\n", nvpair_name(pair));
247 	}
248 }
249 
250 static void
251 zhack_do_feature_stat(int argc, char **argv)
252 {
253 	spa_t *spa;
254 	objset_t *os;
255 	char *target;
256 
257 	argc--;
258 	argv++;
259 
260 	if (argc < 1) {
261 		(void) fprintf(stderr, "error: missing pool name\n");
262 		usage();
263 	}
264 	target = argv[0];
265 
266 	zhack_spa_open(target, B_TRUE, FTAG, &spa);
267 	os = spa->spa_meta_objset;
268 
269 	dump_obj(os, spa->spa_feat_for_read_obj, "for_read");
270 	dump_obj(os, spa->spa_feat_for_write_obj, "for_write");
271 	dump_obj(os, spa->spa_feat_desc_obj, "descriptions");
272 	dump_mos(spa);
273 
274 	spa_close(spa, FTAG);
275 }
276 
277 static void
278 feature_enable_sync(void *arg, dmu_tx_t *tx)
279 {
280 	spa_t *spa = dmu_tx_pool(tx)->dp_spa;
281 	zfeature_info_t *feature = arg;
282 
283 	spa_feature_enable(spa, feature, tx);
284 	spa_history_log_internal(spa, "zhack enable feature", tx,
285 	    "guid=%s can_readonly=%u",
286 	    feature->fi_guid, feature->fi_can_readonly);
287 }
288 
289 static void
290 zhack_do_feature_enable(int argc, char **argv)
291 {
292 	char c;
293 	char *desc, *target;
294 	spa_t *spa;
295 	objset_t *mos;
296 	zfeature_info_t feature;
297 	zfeature_info_t *nodeps[] = { NULL };
298 
299 	/*
300 	 * Features are not added to the pool's label until their refcounts
301 	 * are incremented, so fi_mos can just be left as false for now.
302 	 */
303 	desc = NULL;
304 	feature.fi_uname = "zhack";
305 	feature.fi_mos = B_FALSE;
306 	feature.fi_can_readonly = B_FALSE;
307 	feature.fi_depends = nodeps;
308 
309 	optind = 1;
310 	while ((c = getopt(argc, argv, "rmd:")) != -1) {
311 		switch (c) {
312 		case 'r':
313 			feature.fi_can_readonly = B_TRUE;
314 			break;
315 		case 'd':
316 			desc = strdup(optarg);
317 			break;
318 		default:
319 			usage();
320 			break;
321 		}
322 	}
323 
324 	if (desc == NULL)
325 		desc = strdup("zhack injected");
326 	feature.fi_desc = desc;
327 
328 	argc -= optind;
329 	argv += optind;
330 
331 	if (argc < 2) {
332 		(void) fprintf(stderr, "error: missing feature or pool name\n");
333 		usage();
334 	}
335 	target = argv[0];
336 	feature.fi_guid = argv[1];
337 
338 	if (!zfeature_is_valid_guid(feature.fi_guid))
339 		fatal("invalid feature guid: %s", feature.fi_guid);
340 
341 	zhack_spa_open(target, B_FALSE, FTAG, &spa);
342 	mos = spa->spa_meta_objset;
343 
344 	if (0 == zfeature_lookup_guid(feature.fi_guid, NULL))
345 		fatal("'%s' is a real feature, will not enable");
346 	if (0 == zap_contains(mos, spa->spa_feat_desc_obj, feature.fi_guid))
347 		fatal("feature already enabled: %s", feature.fi_guid);
348 
349 	VERIFY0(dsl_sync_task(spa_name(spa), NULL,
350 	    feature_enable_sync, &feature, 5));
351 
352 	spa_close(spa, FTAG);
353 
354 	free(desc);
355 }
356 
357 static void
358 feature_incr_sync(void *arg, dmu_tx_t *tx)
359 {
360 	spa_t *spa = dmu_tx_pool(tx)->dp_spa;
361 	zfeature_info_t *feature = arg;
362 
363 	spa_feature_incr(spa, feature, tx);
364 	spa_history_log_internal(spa, "zhack feature incr", tx,
365 	    "guid=%s", feature->fi_guid);
366 }
367 
368 static void
369 feature_decr_sync(void *arg, dmu_tx_t *tx)
370 {
371 	spa_t *spa = dmu_tx_pool(tx)->dp_spa;
372 	zfeature_info_t *feature = arg;
373 
374 	spa_feature_decr(spa, feature, tx);
375 	spa_history_log_internal(spa, "zhack feature decr", tx,
376 	    "guid=%s", feature->fi_guid);
377 }
378 
379 static void
380 zhack_do_feature_ref(int argc, char **argv)
381 {
382 	char c;
383 	char *target;
384 	boolean_t decr = B_FALSE;
385 	spa_t *spa;
386 	objset_t *mos;
387 	zfeature_info_t feature;
388 	zfeature_info_t *nodeps[] = { NULL };
389 
390 	/*
391 	 * fi_desc does not matter here because it was written to disk
392 	 * when the feature was enabled, but we need to properly set the
393 	 * feature for read or write based on the information we read off
394 	 * disk later.
395 	 */
396 	feature.fi_uname = "zhack";
397 	feature.fi_mos = B_FALSE;
398 	feature.fi_desc = NULL;
399 	feature.fi_depends = nodeps;
400 
401 	optind = 1;
402 	while ((c = getopt(argc, argv, "md")) != -1) {
403 		switch (c) {
404 		case 'm':
405 			feature.fi_mos = B_TRUE;
406 			break;
407 		case 'd':
408 			decr = B_TRUE;
409 			break;
410 		default:
411 			usage();
412 			break;
413 		}
414 	}
415 	argc -= optind;
416 	argv += optind;
417 
418 	if (argc < 2) {
419 		(void) fprintf(stderr, "error: missing feature or pool name\n");
420 		usage();
421 	}
422 	target = argv[0];
423 	feature.fi_guid = argv[1];
424 
425 	if (!zfeature_is_valid_guid(feature.fi_guid))
426 		fatal("invalid feature guid: %s", feature.fi_guid);
427 
428 	zhack_spa_open(target, B_FALSE, FTAG, &spa);
429 	mos = spa->spa_meta_objset;
430 
431 	if (0 == zfeature_lookup_guid(feature.fi_guid, NULL))
432 		fatal("'%s' is a real feature, will not change refcount");
433 
434 	if (0 == zap_contains(mos, spa->spa_feat_for_read_obj,
435 	    feature.fi_guid)) {
436 		feature.fi_can_readonly = B_FALSE;
437 	} else if (0 == zap_contains(mos, spa->spa_feat_for_write_obj,
438 	    feature.fi_guid)) {
439 		feature.fi_can_readonly = B_TRUE;
440 	} else {
441 		fatal("feature is not enabled: %s", feature.fi_guid);
442 	}
443 
444 	if (decr && !spa_feature_is_active(spa, &feature))
445 		fatal("feature refcount already 0: %s", feature.fi_guid);
446 
447 	VERIFY0(dsl_sync_task(spa_name(spa), NULL,
448 	    decr ? feature_decr_sync : feature_incr_sync, &feature, 5));
449 
450 	spa_close(spa, FTAG);
451 }
452 
453 static int
454 zhack_do_feature(int argc, char **argv)
455 {
456 	char *subcommand;
457 
458 	argc--;
459 	argv++;
460 	if (argc == 0) {
461 		(void) fprintf(stderr,
462 		    "error: no feature operation specified\n");
463 		usage();
464 	}
465 
466 	subcommand = argv[0];
467 	if (strcmp(subcommand, "stat") == 0) {
468 		zhack_do_feature_stat(argc, argv);
469 	} else if (strcmp(subcommand, "enable") == 0) {
470 		zhack_do_feature_enable(argc, argv);
471 	} else if (strcmp(subcommand, "ref") == 0) {
472 		zhack_do_feature_ref(argc, argv);
473 	} else {
474 		(void) fprintf(stderr, "error: unknown subcommand: %s\n",
475 		    subcommand);
476 		usage();
477 	}
478 
479 	return (0);
480 }
481 
482 #define	MAX_NUM_PATHS 1024
483 
484 int
485 main(int argc, char **argv)
486 {
487 	extern void zfs_prop_init(void);
488 
489 	char *path[MAX_NUM_PATHS];
490 	const char *subcommand;
491 	int rv = 0;
492 	char c;
493 
494 	g_importargs.path = path;
495 
496 	dprintf_setup(&argc, argv);
497 	zfs_prop_init();
498 
499 	while ((c = getopt(argc, argv, "c:d:")) != -1) {
500 		switch (c) {
501 		case 'c':
502 			g_importargs.cachefile = optarg;
503 			break;
504 		case 'd':
505 			assert(g_importargs.paths < MAX_NUM_PATHS);
506 			g_importargs.path[g_importargs.paths++] = optarg;
507 			break;
508 		default:
509 			usage();
510 			break;
511 		}
512 	}
513 
514 	argc -= optind;
515 	argv += optind;
516 	optind = 1;
517 
518 	if (argc == 0) {
519 		(void) fprintf(stderr, "error: no command specified\n");
520 		usage();
521 	}
522 
523 	subcommand = argv[0];
524 
525 	if (strcmp(subcommand, "feature") == 0) {
526 		rv = zhack_do_feature(argc, argv);
527 	} else {
528 		(void) fprintf(stderr, "error: unknown subcommand: %s\n",
529 		    subcommand);
530 		usage();
531 	}
532 
533 	if (!g_readonly && spa_export(g_pool, NULL, B_TRUE, B_TRUE) != 0) {
534 		fatal("pool export failed; "
535 		    "changes may not be committed to disk\n");
536 	}
537 
538 	libzfs_fini(g_zfs);
539 	kernel_fini();
540 
541 	return (rv);
542 }
543