xref: /illumos-gate/usr/src/cmd/zhack/zhack.c (revision 7fdd916c474ea52896c671bbe7b56ba34a1ca132)
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) 2013 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 	dump_mos(spa);
281 
282 	spa_close(spa, FTAG);
283 }
284 
285 static void
286 feature_enable_sync(void *arg, dmu_tx_t *tx)
287 {
288 	spa_t *spa = dmu_tx_pool(tx)->dp_spa;
289 	zfeature_info_t *feature = arg;
290 
291 	spa_feature_enable(spa, feature, tx);
292 	spa_history_log_internal(spa, "zhack enable feature", tx,
293 	    "guid=%s can_readonly=%u",
294 	    feature->fi_guid, feature->fi_can_readonly);
295 }
296 
297 static void
298 zhack_do_feature_enable(int argc, char **argv)
299 {
300 	char c;
301 	char *desc, *target;
302 	spa_t *spa;
303 	objset_t *mos;
304 	zfeature_info_t feature;
305 	zfeature_info_t *nodeps[] = { NULL };
306 
307 	/*
308 	 * Features are not added to the pool's label until their refcounts
309 	 * are incremented, so fi_mos can just be left as false for now.
310 	 */
311 	desc = NULL;
312 	feature.fi_uname = "zhack";
313 	feature.fi_mos = B_FALSE;
314 	feature.fi_can_readonly = B_FALSE;
315 	feature.fi_depends = nodeps;
316 
317 	optind = 1;
318 	while ((c = getopt(argc, argv, "rmd:")) != -1) {
319 		switch (c) {
320 		case 'r':
321 			feature.fi_can_readonly = B_TRUE;
322 			break;
323 		case 'd':
324 			desc = strdup(optarg);
325 			break;
326 		default:
327 			usage();
328 			break;
329 		}
330 	}
331 
332 	if (desc == NULL)
333 		desc = strdup("zhack injected");
334 	feature.fi_desc = desc;
335 
336 	argc -= optind;
337 	argv += optind;
338 
339 	if (argc < 2) {
340 		(void) fprintf(stderr, "error: missing feature or pool name\n");
341 		usage();
342 	}
343 	target = argv[0];
344 	feature.fi_guid = argv[1];
345 
346 	if (!zfeature_is_valid_guid(feature.fi_guid))
347 		fatal(NULL, FTAG, "invalid feature guid: %s", feature.fi_guid);
348 
349 	zhack_spa_open(target, B_FALSE, FTAG, &spa);
350 	mos = spa->spa_meta_objset;
351 
352 	if (0 == zfeature_lookup_guid(feature.fi_guid, NULL))
353 		fatal(spa, FTAG, "'%s' is a real feature, will not enable");
354 	if (0 == zap_contains(mos, spa->spa_feat_desc_obj, feature.fi_guid))
355 		fatal(spa, FTAG, "feature already enabled: %s",
356 		    feature.fi_guid);
357 
358 	VERIFY0(dsl_sync_task(spa_name(spa), NULL,
359 	    feature_enable_sync, &feature, 5));
360 
361 	spa_close(spa, FTAG);
362 
363 	free(desc);
364 }
365 
366 static void
367 feature_incr_sync(void *arg, dmu_tx_t *tx)
368 {
369 	spa_t *spa = dmu_tx_pool(tx)->dp_spa;
370 	zfeature_info_t *feature = arg;
371 
372 	spa_feature_incr(spa, feature, tx);
373 	spa_history_log_internal(spa, "zhack feature incr", tx,
374 	    "guid=%s", feature->fi_guid);
375 }
376 
377 static void
378 feature_decr_sync(void *arg, dmu_tx_t *tx)
379 {
380 	spa_t *spa = dmu_tx_pool(tx)->dp_spa;
381 	zfeature_info_t *feature = arg;
382 
383 	spa_feature_decr(spa, feature, tx);
384 	spa_history_log_internal(spa, "zhack feature decr", tx,
385 	    "guid=%s", feature->fi_guid);
386 }
387 
388 static void
389 zhack_do_feature_ref(int argc, char **argv)
390 {
391 	char c;
392 	char *target;
393 	boolean_t decr = B_FALSE;
394 	spa_t *spa;
395 	objset_t *mos;
396 	zfeature_info_t feature;
397 	zfeature_info_t *nodeps[] = { NULL };
398 
399 	/*
400 	 * fi_desc does not matter here because it was written to disk
401 	 * when the feature was enabled, but we need to properly set the
402 	 * feature for read or write based on the information we read off
403 	 * disk later.
404 	 */
405 	feature.fi_uname = "zhack";
406 	feature.fi_mos = B_FALSE;
407 	feature.fi_desc = NULL;
408 	feature.fi_depends = nodeps;
409 
410 	optind = 1;
411 	while ((c = getopt(argc, argv, "md")) != -1) {
412 		switch (c) {
413 		case 'm':
414 			feature.fi_mos = B_TRUE;
415 			break;
416 		case 'd':
417 			decr = B_TRUE;
418 			break;
419 		default:
420 			usage();
421 			break;
422 		}
423 	}
424 	argc -= optind;
425 	argv += optind;
426 
427 	if (argc < 2) {
428 		(void) fprintf(stderr, "error: missing feature or pool name\n");
429 		usage();
430 	}
431 	target = argv[0];
432 	feature.fi_guid = argv[1];
433 
434 	if (!zfeature_is_valid_guid(feature.fi_guid))
435 		fatal(NULL, FTAG, "invalid feature guid: %s", feature.fi_guid);
436 
437 	zhack_spa_open(target, B_FALSE, FTAG, &spa);
438 	mos = spa->spa_meta_objset;
439 
440 	if (0 == zfeature_lookup_guid(feature.fi_guid, NULL))
441 		fatal(spa, FTAG, "'%s' is a real feature, will not change "
442 		    "refcount");
443 
444 	if (0 == zap_contains(mos, spa->spa_feat_for_read_obj,
445 	    feature.fi_guid)) {
446 		feature.fi_can_readonly = B_FALSE;
447 	} else if (0 == zap_contains(mos, spa->spa_feat_for_write_obj,
448 	    feature.fi_guid)) {
449 		feature.fi_can_readonly = B_TRUE;
450 	} else {
451 		fatal(spa, FTAG, "feature is not enabled: %s", feature.fi_guid);
452 	}
453 
454 	if (decr && !spa_feature_is_active(spa, &feature))
455 		fatal(spa, FTAG, "feature refcount already 0: %s",
456 		    feature.fi_guid);
457 
458 	VERIFY0(dsl_sync_task(spa_name(spa), NULL,
459 	    decr ? feature_decr_sync : feature_incr_sync, &feature, 5));
460 
461 	spa_close(spa, FTAG);
462 }
463 
464 static int
465 zhack_do_feature(int argc, char **argv)
466 {
467 	char *subcommand;
468 
469 	argc--;
470 	argv++;
471 	if (argc == 0) {
472 		(void) fprintf(stderr,
473 		    "error: no feature operation specified\n");
474 		usage();
475 	}
476 
477 	subcommand = argv[0];
478 	if (strcmp(subcommand, "stat") == 0) {
479 		zhack_do_feature_stat(argc, argv);
480 	} else if (strcmp(subcommand, "enable") == 0) {
481 		zhack_do_feature_enable(argc, argv);
482 	} else if (strcmp(subcommand, "ref") == 0) {
483 		zhack_do_feature_ref(argc, argv);
484 	} else {
485 		(void) fprintf(stderr, "error: unknown subcommand: %s\n",
486 		    subcommand);
487 		usage();
488 	}
489 
490 	return (0);
491 }
492 
493 #define	MAX_NUM_PATHS 1024
494 
495 int
496 main(int argc, char **argv)
497 {
498 	extern void zfs_prop_init(void);
499 
500 	char *path[MAX_NUM_PATHS];
501 	const char *subcommand;
502 	int rv = 0;
503 	char c;
504 
505 	g_importargs.path = path;
506 
507 	dprintf_setup(&argc, argv);
508 	zfs_prop_init();
509 
510 	while ((c = getopt(argc, argv, "c:d:")) != -1) {
511 		switch (c) {
512 		case 'c':
513 			g_importargs.cachefile = optarg;
514 			break;
515 		case 'd':
516 			assert(g_importargs.paths < MAX_NUM_PATHS);
517 			g_importargs.path[g_importargs.paths++] = optarg;
518 			break;
519 		default:
520 			usage();
521 			break;
522 		}
523 	}
524 
525 	argc -= optind;
526 	argv += optind;
527 	optind = 1;
528 
529 	if (argc == 0) {
530 		(void) fprintf(stderr, "error: no command specified\n");
531 		usage();
532 	}
533 
534 	subcommand = argv[0];
535 
536 	if (strcmp(subcommand, "feature") == 0) {
537 		rv = zhack_do_feature(argc, argv);
538 	} else {
539 		(void) fprintf(stderr, "error: unknown subcommand: %s\n",
540 		    subcommand);
541 		usage();
542 	}
543 
544 	if (!g_readonly && spa_export(g_pool, NULL, B_TRUE, B_FALSE) != 0) {
545 		fatal(NULL, FTAG, "pool export failed; "
546 		    "changes may not be committed to disk\n");
547 	}
548 
549 	libzfs_fini(g_zfs);
550 	kernel_fini();
551 
552 	return (rv);
553 }
554