xref: /titanic_51/usr/src/cmd/zhack/zhack.c (revision 6a3e8e8695d5c7d1d18c6800d676990d7f61a2a4)
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  */
25 
26 /*
27  * zhack is a debugging tool that can write changes to ZFS pool using libzpool
28  * for testing purposes. Altering pools with zhack is unsupported and may
29  * result in corrupted pools.
30  */
31 
32 #include <stdio.h>
33 #include <stdlib.h>
34 #include <ctype.h>
35 #include <sys/zfs_context.h>
36 #include <sys/spa.h>
37 #include <sys/spa_impl.h>
38 #include <sys/dmu.h>
39 #include <sys/zap.h>
40 #include <sys/zfs_znode.h>
41 #include <sys/dsl_synctask.h>
42 #include <sys/vdev.h>
43 #include <sys/fs/zfs.h>
44 #include <sys/dmu_objset.h>
45 #include <sys/dsl_pool.h>
46 #include <sys/zio_checksum.h>
47 #include <sys/zio_compress.h>
48 #include <sys/zfeature.h>
49 #undef ZFS_MAXNAMELEN
50 #undef verify
51 #include <libzfs.h>
52 
53 extern boolean_t zfeature_checks_disable;
54 
55 const char cmdname[] = "zhack";
56 libzfs_handle_t *g_zfs;
57 static importargs_t g_importargs;
58 static char *g_pool;
59 static boolean_t g_readonly;
60 
61 static void
62 usage(void)
63 {
64 	(void) fprintf(stderr,
65 	    "Usage: %s [-c cachefile] [-d dir] <subcommand> <args> ...\n"
66 	    "where <subcommand> <args> is one of the following:\n"
67 	    "\n", cmdname);
68 
69 	(void) fprintf(stderr,
70 	    "    feature stat <pool>\n"
71 	    "        print information about enabled features\n"
72 	    "    feature enable [-d desc] <pool> <feature>\n"
73 	    "        add a new enabled feature to the pool\n"
74 	    "        -d <desc> sets the feature's description\n"
75 	    "    feature ref [-md] <pool> <feature>\n"
76 	    "        change the refcount on the given feature\n"
77 	    "        -d decrease instead of increase the refcount\n"
78 	    "        -m add the feature to the label if increasing refcount\n"
79 	    "\n"
80 	    "    <feature> : should be a feature guid\n");
81 	exit(1);
82 }
83 
84 
85 static void
86 fatal(const char *fmt, ...)
87 {
88 	va_list ap;
89 
90 	va_start(ap, fmt);
91 	(void) fprintf(stderr, "%s: ", cmdname);
92 	(void) vfprintf(stderr, fmt, ap);
93 	va_end(ap);
94 	(void) fprintf(stderr, "\n");
95 
96 	exit(1);
97 }
98 
99 /* ARGSUSED */
100 static int
101 space_delta_cb(dmu_object_type_t bonustype, void *data,
102     uint64_t *userp, uint64_t *groupp)
103 {
104 	/*
105 	 * Is it a valid type of object to track?
106 	 */
107 	if (bonustype != DMU_OT_ZNODE && bonustype != DMU_OT_SA)
108 		return (ENOENT);
109 	(void) fprintf(stderr, "modifying object that needs user accounting");
110 	abort();
111 	/* NOTREACHED */
112 }
113 
114 /*
115  * Target is the dataset whose pool we want to open.
116  */
117 static void
118 import_pool(const char *target, boolean_t readonly)
119 {
120 	nvlist_t *config;
121 	nvlist_t *pools;
122 	int error;
123 	char *sepp;
124 	spa_t *spa;
125 	nvpair_t *elem;
126 	nvlist_t *props;
127 	const char *name;
128 
129 	kernel_init(readonly ? FREAD : (FREAD | FWRITE));
130 	g_zfs = libzfs_init();
131 	ASSERT(g_zfs != NULL);
132 
133 	dmu_objset_register_type(DMU_OST_ZFS, space_delta_cb);
134 
135 	g_readonly = readonly;
136 
137 	/*
138 	 * If we only want readonly access, it's OK if we find
139 	 * a potentially-active (ie, imported into the kernel) pool from the
140 	 * default cachefile.
141 	 */
142 	if (readonly && spa_open(target, &spa, FTAG) == 0) {
143 		spa_close(spa, FTAG);
144 		return;
145 	}
146 
147 	g_importargs.unique = B_TRUE;
148 	g_importargs.can_be_active = readonly;
149 	g_pool = strdup(target);
150 	if ((sepp = strpbrk(g_pool, "/@")) != NULL)
151 		*sepp = '\0';
152 	g_importargs.poolname = g_pool;
153 	pools = zpool_search_import(g_zfs, &g_importargs);
154 
155 	if (pools == NULL || nvlist_next_nvpair(pools, NULL) == NULL) {
156 		if (!g_importargs.can_be_active) {
157 			g_importargs.can_be_active = B_TRUE;
158 			if (zpool_search_import(g_zfs, &g_importargs) != NULL ||
159 			    spa_open(target, &spa, FTAG) == 0) {
160 				fatal("cannot import '%s': pool is active; run "
161 				    "\"zpool export %s\" first\n",
162 				    g_pool, g_pool);
163 			}
164 		}
165 
166 		fatal("cannot import '%s': no such pool available\n", g_pool);
167 	}
168 
169 	elem = nvlist_next_nvpair(pools, NULL);
170 	name = nvpair_name(elem);
171 	verify(nvpair_value_nvlist(elem, &config) == 0);
172 
173 	props = NULL;
174 	if (readonly) {
175 		verify(nvlist_alloc(&props, NV_UNIQUE_NAME, 0) == 0);
176 		verify(nvlist_add_uint64(props,
177 		    zpool_prop_to_name(ZPOOL_PROP_READONLY), 1) == 0);
178 	}
179 
180 	zfeature_checks_disable = B_TRUE;
181 	error = spa_import(name, config, props, ZFS_IMPORT_NORMAL);
182 	zfeature_checks_disable = B_FALSE;
183 	if (error == EEXIST)
184 		error = 0;
185 
186 	if (error)
187 		fatal("can't import '%s': %s", name, strerror(error));
188 }
189 
190 static void
191 zhack_spa_open(const char *target, boolean_t readonly, void *tag, spa_t **spa)
192 {
193 	int err;
194 
195 	import_pool(target, readonly);
196 
197 	zfeature_checks_disable = B_TRUE;
198 	err = spa_open(target, spa, tag);
199 	zfeature_checks_disable = B_FALSE;
200 
201 	if (err != 0)
202 		fatal("cannot open '%s': %s", target, strerror(err));
203 	if (spa_version(*spa) < SPA_VERSION_FEATURES) {
204 		fatal("'%s' has version %d, features not enabled", target,
205 		    (int)spa_version(*spa));
206 	}
207 }
208 
209 static void
210 dump_obj(objset_t *os, uint64_t obj, const char *name)
211 {
212 	zap_cursor_t zc;
213 	zap_attribute_t za;
214 
215 	(void) printf("%s_obj:\n", name);
216 
217 	for (zap_cursor_init(&zc, os, obj);
218 	    zap_cursor_retrieve(&zc, &za) == 0;
219 	    zap_cursor_advance(&zc)) {
220 		if (za.za_integer_length == 8) {
221 			ASSERT(za.za_num_integers == 1);
222 			(void) printf("\t%s = %llu\n",
223 			    za.za_name, (u_longlong_t)za.za_first_integer);
224 		} else {
225 			ASSERT(za.za_integer_length == 1);
226 			char val[1024];
227 			VERIFY(zap_lookup(os, obj, za.za_name,
228 			    1, sizeof (val), val) == 0);
229 			(void) printf("\t%s = %s\n", za.za_name, val);
230 		}
231 	}
232 	zap_cursor_fini(&zc);
233 }
234 
235 static void
236 dump_mos(spa_t *spa)
237 {
238 	nvlist_t *nv = spa->spa_label_features;
239 
240 	(void) printf("label config:\n");
241 	for (nvpair_t *pair = nvlist_next_nvpair(nv, NULL);
242 	    pair != NULL;
243 	    pair = nvlist_next_nvpair(nv, pair)) {
244 		(void) printf("\t%s\n", nvpair_name(pair));
245 	}
246 }
247 
248 static void
249 zhack_do_feature_stat(int argc, char **argv)
250 {
251 	spa_t *spa;
252 	objset_t *os;
253 	char *target;
254 
255 	argc--;
256 	argv++;
257 
258 	if (argc < 1) {
259 		(void) fprintf(stderr, "error: missing pool name\n");
260 		usage();
261 	}
262 	target = argv[0];
263 
264 	zhack_spa_open(target, B_TRUE, FTAG, &spa);
265 	os = spa->spa_meta_objset;
266 
267 	dump_obj(os, spa->spa_feat_for_read_obj, "for_read");
268 	dump_obj(os, spa->spa_feat_for_write_obj, "for_write");
269 	dump_obj(os, spa->spa_feat_desc_obj, "descriptions");
270 	dump_mos(spa);
271 
272 	spa_close(spa, FTAG);
273 }
274 
275 static void
276 feature_enable_sync(void *arg1, void *arg2, dmu_tx_t *tx)
277 {
278 	spa_t *spa = arg1;
279 	zfeature_info_t *feature = arg2;
280 
281 	spa_feature_enable(spa, feature, tx);
282 }
283 
284 static void
285 zhack_do_feature_enable(int argc, char **argv)
286 {
287 	char c;
288 	char *desc, *target;
289 	spa_t *spa;
290 	objset_t *mos;
291 	zfeature_info_t feature;
292 	zfeature_info_t *nodeps[] = { NULL };
293 
294 	/*
295 	 * Features are not added to the pool's label until their refcounts
296 	 * are incremented, so fi_mos can just be left as false for now.
297 	 */
298 	desc = NULL;
299 	feature.fi_uname = "zhack";
300 	feature.fi_mos = B_FALSE;
301 	feature.fi_can_readonly = B_FALSE;
302 	feature.fi_depends = nodeps;
303 
304 	optind = 1;
305 	while ((c = getopt(argc, argv, "rmd:")) != -1) {
306 		switch (c) {
307 		case 'r':
308 			feature.fi_can_readonly = B_TRUE;
309 			break;
310 		case 'd':
311 			desc = strdup(optarg);
312 			break;
313 		default:
314 			usage();
315 			break;
316 		}
317 	}
318 
319 	if (desc == NULL)
320 		desc = strdup("zhack injected");
321 	feature.fi_desc = desc;
322 
323 	argc -= optind;
324 	argv += optind;
325 
326 	if (argc < 2) {
327 		(void) fprintf(stderr, "error: missing feature or pool name\n");
328 		usage();
329 	}
330 	target = argv[0];
331 	feature.fi_guid = argv[1];
332 
333 	if (!zfeature_is_valid_guid(feature.fi_guid))
334 		fatal("invalid feature guid: %s", feature.fi_guid);
335 
336 	zhack_spa_open(target, B_FALSE, FTAG, &spa);
337 	mos = spa->spa_meta_objset;
338 
339 	if (0 == zfeature_lookup_guid(feature.fi_guid, NULL))
340 		fatal("'%s' is a real feature, will not enable");
341 	if (0 == zap_contains(mos, spa->spa_feat_desc_obj, feature.fi_guid))
342 		fatal("feature already enabled: %s", feature.fi_guid);
343 
344 	VERIFY3U(0, ==, dsl_sync_task_do(spa->spa_dsl_pool, NULL,
345 	    feature_enable_sync, spa, &feature, 5));
346 
347 	spa_close(spa, FTAG);
348 
349 	free(desc);
350 }
351 
352 static void
353 feature_incr_sync(void *arg1, void *arg2, dmu_tx_t *tx)
354 {
355 	spa_t *spa = arg1;
356 	zfeature_info_t *feature = arg2;
357 
358 	spa_feature_incr(spa, feature, tx);
359 }
360 
361 static void
362 feature_decr_sync(void *arg1, void *arg2, dmu_tx_t *tx)
363 {
364 	spa_t *spa = arg1;
365 	zfeature_info_t *feature = arg2;
366 
367 	spa_feature_decr(spa, feature, tx);
368 }
369 
370 static void
371 zhack_do_feature_ref(int argc, char **argv)
372 {
373 	char c;
374 	char *target;
375 	boolean_t decr = B_FALSE;
376 	spa_t *spa;
377 	objset_t *mos;
378 	zfeature_info_t feature;
379 	zfeature_info_t *nodeps[] = { NULL };
380 
381 	/*
382 	 * fi_desc does not matter here because it was written to disk
383 	 * when the feature was enabled, but we need to properly set the
384 	 * feature for read or write based on the information we read off
385 	 * disk later.
386 	 */
387 	feature.fi_uname = "zhack";
388 	feature.fi_mos = B_FALSE;
389 	feature.fi_desc = NULL;
390 	feature.fi_depends = nodeps;
391 
392 	optind = 1;
393 	while ((c = getopt(argc, argv, "md")) != -1) {
394 		switch (c) {
395 		case 'm':
396 			feature.fi_mos = B_TRUE;
397 			break;
398 		case 'd':
399 			decr = B_TRUE;
400 			break;
401 		default:
402 			usage();
403 			break;
404 		}
405 	}
406 	argc -= optind;
407 	argv += optind;
408 
409 	if (argc < 2) {
410 		(void) fprintf(stderr, "error: missing feature or pool name\n");
411 		usage();
412 	}
413 	target = argv[0];
414 	feature.fi_guid = argv[1];
415 
416 	if (!zfeature_is_valid_guid(feature.fi_guid))
417 		fatal("invalid feature guid: %s", feature.fi_guid);
418 
419 	zhack_spa_open(target, B_FALSE, FTAG, &spa);
420 	mos = spa->spa_meta_objset;
421 
422 	if (0 == zfeature_lookup_guid(feature.fi_guid, NULL))
423 		fatal("'%s' is a real feature, will not change refcount");
424 
425 	if (0 == zap_contains(mos, spa->spa_feat_for_read_obj,
426 	    feature.fi_guid)) {
427 		feature.fi_can_readonly = B_FALSE;
428 	} else if (0 == zap_contains(mos, spa->spa_feat_for_write_obj,
429 	    feature.fi_guid)) {
430 		feature.fi_can_readonly = B_TRUE;
431 	} else {
432 		fatal("feature is not enabled: %s", feature.fi_guid);
433 	}
434 
435 	if (decr && !spa_feature_is_active(spa, &feature))
436 		fatal("feature refcount already 0: %s", feature.fi_guid);
437 
438 	VERIFY3U(0, ==, dsl_sync_task_do(spa->spa_dsl_pool, NULL,
439 	    decr ? feature_decr_sync : feature_incr_sync, spa, &feature, 5));
440 
441 	spa_close(spa, FTAG);
442 }
443 
444 static int
445 zhack_do_feature(int argc, char **argv)
446 {
447 	char *subcommand;
448 
449 	argc--;
450 	argv++;
451 	if (argc == 0) {
452 		(void) fprintf(stderr,
453 		    "error: no feature operation specified\n");
454 		usage();
455 	}
456 
457 	subcommand = argv[0];
458 	if (strcmp(subcommand, "stat") == 0) {
459 		zhack_do_feature_stat(argc, argv);
460 	} else if (strcmp(subcommand, "enable") == 0) {
461 		zhack_do_feature_enable(argc, argv);
462 	} else if (strcmp(subcommand, "ref") == 0) {
463 		zhack_do_feature_ref(argc, argv);
464 	} else {
465 		(void) fprintf(stderr, "error: unknown subcommand: %s\n",
466 		    subcommand);
467 		usage();
468 	}
469 
470 	return (0);
471 }
472 
473 #define	MAX_NUM_PATHS 1024
474 
475 int
476 main(int argc, char **argv)
477 {
478 	extern void zfs_prop_init(void);
479 
480 	char *path[MAX_NUM_PATHS];
481 	const char *subcommand;
482 	int rv = 0;
483 	char c;
484 
485 	g_importargs.path = path;
486 
487 	dprintf_setup(&argc, argv);
488 	zfs_prop_init();
489 
490 	while ((c = getopt(argc, argv, "c:d:")) != -1) {
491 		switch (c) {
492 		case 'c':
493 			g_importargs.cachefile = optarg;
494 			break;
495 		case 'd':
496 			assert(g_importargs.paths < MAX_NUM_PATHS);
497 			g_importargs.path[g_importargs.paths++] = optarg;
498 			break;
499 		default:
500 			usage();
501 			break;
502 		}
503 	}
504 
505 	argc -= optind;
506 	argv += optind;
507 	optind = 1;
508 
509 	if (argc == 0) {
510 		(void) fprintf(stderr, "error: no command specified\n");
511 		usage();
512 	}
513 
514 	subcommand = argv[0];
515 
516 	if (strcmp(subcommand, "feature") == 0) {
517 		rv = zhack_do_feature(argc, argv);
518 	} else {
519 		(void) fprintf(stderr, "error: unknown subcommand: %s\n",
520 		    subcommand);
521 		usage();
522 	}
523 
524 	if (!g_readonly && spa_export(g_pool, NULL, B_TRUE, B_TRUE) != 0) {
525 		fatal("pool export failed; "
526 		    "changes may not be committed to disk\n");
527 	}
528 
529 	libzfs_fini(g_zfs);
530 	kernel_fini();
531 
532 	return (rv);
533 }
534