xref: /illumos-gate/usr/src/cmd/zinject/zinject.c (revision 4eaa471005973e11a6110b69fe990530b3b95a38)
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  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 /*
27  * ZFS Fault Injector
28  *
29  * This userland component takes a set of options and uses libzpool to translate
30  * from a user-visible object type and name to an internal representation.
31  * There are two basic types of faults: device faults and data faults.
32  *
33  *
34  * DEVICE FAULTS
35  *
36  * Errors can be injected into a particular vdev using the '-d' option.  This
37  * option takes a path or vdev GUID to uniquely identify the device within a
38  * pool.  There are two types of errors that can be injected, EIO and ENXIO,
39  * that can be controlled through the '-e' option.  The default is ENXIO.  For
40  * EIO failures, any attempt to read data from the device will return EIO, but
41  * subsequent attempt to reopen the device will succeed.  For ENXIO failures,
42  * any attempt to read from the device will return EIO, but any attempt to
43  * reopen the device will also return ENXIO.
44  * For label faults, the -L option must be specified. This allows faults
45  * to be injected into either the nvlist or uberblock region of all the labels
46  * for the specified device.
47  *
48  * This form of the command looks like:
49  *
50  * 	zinject -d device [-e errno] [-L <uber | nvlist>] pool
51  *
52  *
53  * DATA FAULTS
54  *
55  * We begin with a tuple of the form:
56  *
57  * 	<type,level,range,object>
58  *
59  * 	type	A string describing the type of data to target.  Each type
60  * 		implicitly describes how to interpret 'object'. Currently,
61  * 		the following values are supported:
62  *
63  * 		data		User data for a file
64  * 		dnode		Dnode for a file or directory
65  *
66  *		The following MOS objects are special.  Instead of injecting
67  *		errors on a particular object or blkid, we inject errors across
68  *		all objects of the given type.
69  *
70  * 		mos		Any data in the MOS
71  * 		mosdir		object directory
72  * 		config		pool configuration
73  * 		bplist		blkptr list
74  * 		spacemap	spacemap
75  * 		metaslab	metaslab
76  * 		errlog		persistent error log
77  *
78  * 	level	Object level.  Defaults to '0', not applicable to all types.  If
79  * 		a range is given, this corresponds to the indirect block
80  * 		corresponding to the specific range.
81  *
82  *	range	A numerical range [start,end) within the object.  Defaults to
83  *		the full size of the file.
84  *
85  * 	object	A string describing the logical location of the object.  For
86  * 		files and directories (currently the only supported types),
87  * 		this is the path of the object on disk.
88  *
89  * This is translated, via libzpool, into the following internal representation:
90  *
91  * 	<type,objset,object,level,range>
92  *
93  * These types should be self-explanatory.  This tuple is then passed to the
94  * kernel via a special ioctl() to initiate fault injection for the given
95  * object.  Note that 'type' is not strictly necessary for fault injection, but
96  * is used when translating existing faults into a human-readable string.
97  *
98  *
99  * The command itself takes one of the forms:
100  *
101  * 	zinject
102  * 	zinject <-a | -u pool>
103  * 	zinject -c <id|all>
104  * 	zinject [-q] <-t type> [-f freq] [-u] [-a] [-m] [-e errno] [-l level]
105  *	    [-r range] <object>
106  * 	zinject [-f freq] [-a] [-m] [-u] -b objset:object:level:start:end pool
107  *
108  * With no arguments, the command prints all currently registered injection
109  * handlers, with their numeric identifiers.
110  *
111  * The '-c' option will clear the given handler, or all handlers if 'all' is
112  * specified.
113  *
114  * The '-e' option takes a string describing the errno to simulate.  This must
115  * be either 'io' or 'checksum'.  In most cases this will result in the same
116  * behavior, but RAID-Z will produce a different set of ereports for this
117  * situation.
118  *
119  * The '-a', '-u', and '-m' flags toggle internal flush behavior.  If '-a' is
120  * specified, then the ARC cache is flushed appropriately.  If '-u' is
121  * specified, then the underlying SPA is unloaded.  Either of these flags can be
122  * specified independently of any other handlers.  The '-m' flag automatically
123  * does an unmount and remount of the underlying dataset to aid in flushing the
124  * cache.
125  *
126  * The '-f' flag controls the frequency of errors injected, expressed as a
127  * integer percentage between 1 and 100.  The default is 100.
128  *
129  * The this form is responsible for actually injecting the handler into the
130  * framework.  It takes the arguments described above, translates them to the
131  * internal tuple using libzpool, and then issues an ioctl() to register the
132  * handler.
133  *
134  * The final form can target a specific bookmark, regardless of whether a
135  * human-readable interface has been designed.  It allows developers to specify
136  * a particular block by number.
137  */
138 
139 #include <errno.h>
140 #include <fcntl.h>
141 #include <stdio.h>
142 #include <stdlib.h>
143 #include <strings.h>
144 #include <unistd.h>
145 
146 #include <sys/fs/zfs.h>
147 #include <sys/mount.h>
148 
149 #include <libzfs.h>
150 
151 #undef verify	/* both libzfs.h and zfs_context.h want to define this */
152 
153 #include "zinject.h"
154 
155 libzfs_handle_t *g_zfs;
156 int zfs_fd;
157 
158 #define	ECKSUM	EBADE
159 
160 static const char *errtable[TYPE_INVAL] = {
161 	"data",
162 	"dnode",
163 	"mos",
164 	"mosdir",
165 	"metaslab",
166 	"config",
167 	"bplist",
168 	"spacemap",
169 	"errlog",
170 	"uber",
171 	"nvlist"
172 };
173 
174 static err_type_t
175 name_to_type(const char *arg)
176 {
177 	int i;
178 	for (i = 0; i < TYPE_INVAL; i++)
179 		if (strcmp(errtable[i], arg) == 0)
180 			return (i);
181 
182 	return (TYPE_INVAL);
183 }
184 
185 static const char *
186 type_to_name(uint64_t type)
187 {
188 	switch (type) {
189 	case DMU_OT_OBJECT_DIRECTORY:
190 		return ("mosdir");
191 	case DMU_OT_OBJECT_ARRAY:
192 		return ("metaslab");
193 	case DMU_OT_PACKED_NVLIST:
194 		return ("config");
195 	case DMU_OT_BPLIST:
196 		return ("bplist");
197 	case DMU_OT_SPACE_MAP:
198 		return ("spacemap");
199 	case DMU_OT_ERROR_LOG:
200 		return ("errlog");
201 	default:
202 		return ("-");
203 	}
204 }
205 
206 
207 /*
208  * Print usage message.
209  */
210 void
211 usage(void)
212 {
213 	(void) printf(
214 	    "usage:\n"
215 	    "\n"
216 	    "\tzinject\n"
217 	    "\n"
218 	    "\t\tList all active injection records.\n"
219 	    "\n"
220 	    "\tzinject -c <id|all>\n"
221 	    "\n"
222 	    "\t\tClear the particular record (if given a numeric ID), or\n"
223 	    "\t\tall records if 'all' is specificed.\n"
224 	    "\n"
225 	    "\tzinject -d device [-e errno] [-L <nvlist|uber>] [-F] pool\n"
226 	    "\t\tInject a fault into a particular device or the device's\n"
227 	    "\t\tlabel.  Label injection can either be 'nvlist' or 'uber'.\n"
228 	    "\t\t'errno' can either be 'nxio' (the default) or 'io'.\n"
229 	    "\n"
230 	    "\tzinject -b objset:object:level:blkid pool\n"
231 	    "\n"
232 	    "\t\tInject an error into pool 'pool' with the numeric bookmark\n"
233 	    "\t\tspecified by the remaining tuple.  Each number is in\n"
234 	    "\t\thexidecimal, and only one block can be specified.\n"
235 	    "\n"
236 	    "\tzinject [-q] <-t type> [-e errno] [-l level] [-r range]\n"
237 	    "\t    [-a] [-m] [-u] [-f freq] <object>\n"
238 	    "\n"
239 	    "\t\tInject an error into the object specified by the '-t' option\n"
240 	    "\t\tand the object descriptor.  The 'object' parameter is\n"
241 	    "\t\tinterperted depending on the '-t' option.\n"
242 	    "\n"
243 	    "\t\t-q\tQuiet mode.  Only print out the handler number added.\n"
244 	    "\t\t-e\tInject a specific error.  Must be either 'io' or\n"
245 	    "\t\t\t'checksum'.  Default is 'io'.\n"
246 	    "\t\t-l\tInject error at a particular block level. Default is "
247 	    "0.\n"
248 	    "\t\t-m\tAutomatically remount underlying filesystem.\n"
249 	    "\t\t-r\tInject error over a particular logical range of an\n"
250 	    "\t\t\tobject.  Will be translated to the appropriate blkid\n"
251 	    "\t\t\trange according to the object's properties.\n"
252 	    "\t\t-a\tFlush the ARC cache.  Can be specified without any\n"
253 	    "\t\t\tassociated object.\n"
254 	    "\t\t-u\tUnload the associated pool.  Can be specified with only\n"
255 	    "\t\t\ta pool object.\n"
256 	    "\t\t-f\tOnly inject errors a fraction of the time.  Expressed as\n"
257 	    "\t\t\ta percentage between 1 and 100.\n"
258 	    "\n"
259 	    "\t-t data\t\tInject an error into the plain file contents of a\n"
260 	    "\t\t\tfile.  The object must be specified as a complete path\n"
261 	    "\t\t\tto a file on a ZFS filesystem.\n"
262 	    "\n"
263 	    "\t-t dnode\tInject an error into the metadnode in the block\n"
264 	    "\t\t\tcorresponding to the dnode for a file or directory.  The\n"
265 	    "\t\t\t'-r' option is incompatible with this mode.  The object\n"
266 	    "\t\t\tis specified as a complete path to a file or directory\n"
267 	    "\t\t\ton a ZFS filesystem.\n"
268 	    "\n"
269 	    "\t-t <mos>\tInject errors into the MOS for objects of the given\n"
270 	    "\t\t\ttype.  Valid types are: mos, mosdir, config, bplist,\n"
271 	    "\t\t\tspacemap, metaslab, errlog.  The only valid <object> is\n"
272 	    "\t\t\tthe poolname.\n");
273 }
274 
275 static int
276 iter_handlers(int (*func)(int, const char *, zinject_record_t *, void *),
277     void *data)
278 {
279 	zfs_cmd_t zc;
280 	int ret;
281 
282 	zc.zc_guid = 0;
283 
284 	while (ioctl(zfs_fd, ZFS_IOC_INJECT_LIST_NEXT, &zc) == 0)
285 		if ((ret = func((int)zc.zc_guid, zc.zc_name,
286 		    &zc.zc_inject_record, data)) != 0)
287 			return (ret);
288 
289 	return (0);
290 }
291 
292 static int
293 print_data_handler(int id, const char *pool, zinject_record_t *record,
294     void *data)
295 {
296 	int *count = data;
297 
298 	if (record->zi_guid != 0)
299 		return (0);
300 
301 	if (*count == 0) {
302 		(void) printf("%3s  %-15s  %-6s  %-6s  %-8s  %3s  %-15s\n",
303 		    "ID", "POOL", "OBJSET", "OBJECT", "TYPE", "LVL",  "RANGE");
304 		(void) printf("---  ---------------  ------  "
305 		    "------  --------  ---  ---------------\n");
306 	}
307 
308 	*count += 1;
309 
310 	(void) printf("%3d  %-15s  %-6llu  %-6llu  %-8s  %3d  ", id, pool,
311 	    (u_longlong_t)record->zi_objset, (u_longlong_t)record->zi_object,
312 	    type_to_name(record->zi_type), record->zi_level);
313 
314 	if (record->zi_start == 0 &&
315 	    record->zi_end == -1ULL)
316 		(void) printf("all\n");
317 	else
318 		(void) printf("[%llu, %llu]\n", (u_longlong_t)record->zi_start,
319 		    (u_longlong_t)record->zi_end);
320 
321 	return (0);
322 }
323 
324 static int
325 print_device_handler(int id, const char *pool, zinject_record_t *record,
326     void *data)
327 {
328 	int *count = data;
329 
330 	if (record->zi_guid == 0)
331 		return (0);
332 
333 	if (*count == 0) {
334 		(void) printf("%3s  %-15s  %s\n", "ID", "POOL", "GUID");
335 		(void) printf("---  ---------------  ----------------\n");
336 	}
337 
338 	*count += 1;
339 
340 	(void) printf("%3d  %-15s  %llx\n", id, pool,
341 	    (u_longlong_t)record->zi_guid);
342 
343 	return (0);
344 }
345 
346 /*
347  * Print all registered error handlers.  Returns the number of handlers
348  * registered.
349  */
350 static int
351 print_all_handlers(void)
352 {
353 	int count = 0;
354 
355 	(void) iter_handlers(print_device_handler, &count);
356 	(void) printf("\n");
357 	count = 0;
358 	(void) iter_handlers(print_data_handler, &count);
359 
360 	return (count);
361 }
362 
363 /* ARGSUSED */
364 static int
365 cancel_one_handler(int id, const char *pool, zinject_record_t *record,
366     void *data)
367 {
368 	zfs_cmd_t zc;
369 
370 	zc.zc_guid = (uint64_t)id;
371 
372 	if (ioctl(zfs_fd, ZFS_IOC_CLEAR_FAULT, &zc) != 0) {
373 		(void) fprintf(stderr, "failed to remove handler %d: %s\n",
374 		    id, strerror(errno));
375 		return (1);
376 	}
377 
378 	return (0);
379 }
380 
381 /*
382  * Remove all fault injection handlers.
383  */
384 static int
385 cancel_all_handlers(void)
386 {
387 	int ret = iter_handlers(cancel_one_handler, NULL);
388 
389 	(void) printf("removed all registered handlers\n");
390 
391 	return (ret);
392 }
393 
394 /*
395  * Remove a specific fault injection handler.
396  */
397 static int
398 cancel_handler(int id)
399 {
400 	zfs_cmd_t zc;
401 
402 	zc.zc_guid = (uint64_t)id;
403 
404 	if (ioctl(zfs_fd, ZFS_IOC_CLEAR_FAULT, &zc) != 0) {
405 		(void) fprintf(stderr, "failed to remove handler %d: %s\n",
406 		    id, strerror(errno));
407 		return (1);
408 	}
409 
410 	(void) printf("removed handler %d\n", id);
411 
412 	return (0);
413 }
414 
415 /*
416  * Register a new fault injection handler.
417  */
418 static int
419 register_handler(const char *pool, int flags, zinject_record_t *record,
420     int quiet)
421 {
422 	zfs_cmd_t zc;
423 
424 	(void) strcpy(zc.zc_name, pool);
425 	zc.zc_inject_record = *record;
426 	zc.zc_guid = flags;
427 
428 	if (ioctl(zfs_fd, ZFS_IOC_INJECT_FAULT, &zc) != 0) {
429 		(void) fprintf(stderr, "failed to add handler: %s\n",
430 		    strerror(errno));
431 		return (1);
432 	}
433 
434 	if (flags & ZINJECT_NULL)
435 		return (0);
436 
437 	if (quiet) {
438 		(void) printf("%llu\n", (u_longlong_t)zc.zc_guid);
439 	} else {
440 		(void) printf("Added handler %llu with the following "
441 		    "properties:\n", (u_longlong_t)zc.zc_guid);
442 		(void) printf("  pool: %s\n", pool);
443 		if (record->zi_guid) {
444 			(void) printf("  vdev: %llx\n",
445 			    (u_longlong_t)record->zi_guid);
446 		} else {
447 			(void) printf("objset: %llu\n",
448 			    (u_longlong_t)record->zi_objset);
449 			(void) printf("object: %llu\n",
450 			    (u_longlong_t)record->zi_object);
451 			(void) printf("  type: %llu\n",
452 			    (u_longlong_t)record->zi_type);
453 			(void) printf(" level: %d\n", record->zi_level);
454 			if (record->zi_start == 0 &&
455 			    record->zi_end == -1ULL)
456 				(void) printf(" range: all\n");
457 			else
458 				(void) printf(" range: [%llu, %llu)\n",
459 				    (u_longlong_t)record->zi_start,
460 				    (u_longlong_t)record->zi_end);
461 		}
462 	}
463 
464 	return (0);
465 }
466 
467 int
468 main(int argc, char **argv)
469 {
470 	int c;
471 	char *range = NULL;
472 	char *cancel = NULL;
473 	char *end;
474 	char *raw = NULL;
475 	char *device = NULL;
476 	int level = 0;
477 	int quiet = 0;
478 	int error = 0;
479 	int domount = 0;
480 	err_type_t type = TYPE_INVAL;
481 	err_type_t label = TYPE_INVAL;
482 	zinject_record_t record = { 0 };
483 	char pool[MAXNAMELEN];
484 	char dataset[MAXNAMELEN];
485 	zfs_handle_t *zhp;
486 	int ret;
487 	int flags = 0;
488 
489 	if ((g_zfs = libzfs_init()) == NULL) {
490 		(void) fprintf(stderr, "internal error: failed to "
491 		    "initialize ZFS library\n");
492 		return (1);
493 	}
494 
495 	libzfs_print_on_error(g_zfs, B_TRUE);
496 
497 	if ((zfs_fd = open(ZFS_DEV, O_RDWR)) < 0) {
498 		(void) fprintf(stderr, "failed to open ZFS device\n");
499 		return (1);
500 	}
501 
502 	if (argc == 1) {
503 		/*
504 		 * No arguments.  Print the available handlers.  If there are no
505 		 * available handlers, direct the user to '-h' for help
506 		 * information.
507 		 */
508 		if (print_all_handlers() == 0) {
509 			(void) printf("No handlers registered.\n");
510 			(void) printf("Run 'zinject -h' for usage "
511 			    "information.\n");
512 		}
513 
514 		return (0);
515 	}
516 
517 	while ((c = getopt(argc, argv, ":ab:d:f:Fqhc:t:l:mr:e:uL:")) != -1) {
518 		switch (c) {
519 		case 'a':
520 			flags |= ZINJECT_FLUSH_ARC;
521 			break;
522 		case 'b':
523 			raw = optarg;
524 			break;
525 		case 'c':
526 			cancel = optarg;
527 			break;
528 		case 'd':
529 			device = optarg;
530 			break;
531 		case 'e':
532 			if (strcasecmp(optarg, "io") == 0) {
533 				error = EIO;
534 			} else if (strcasecmp(optarg, "checksum") == 0) {
535 				error = ECKSUM;
536 			} else if (strcasecmp(optarg, "nxio") == 0) {
537 				error = ENXIO;
538 			} else {
539 				(void) fprintf(stderr, "invalid error type "
540 				    "'%s': must be 'io', 'checksum' or "
541 				    "'nxio'\n", optarg);
542 				usage();
543 				return (1);
544 			}
545 			break;
546 		case 'f':
547 			record.zi_freq = atoi(optarg);
548 			if (record.zi_freq < 1 || record.zi_freq > 100) {
549 				(void) fprintf(stderr, "frequency range must "
550 				    "be in the range (0, 100]\n");
551 				return (1);
552 			}
553 			break;
554 		case 'F':
555 			record.zi_failfast = B_TRUE;
556 			break;
557 		case 'h':
558 			usage();
559 			return (0);
560 		case 'l':
561 			level = (int)strtol(optarg, &end, 10);
562 			if (*end != '\0') {
563 				(void) fprintf(stderr, "invalid level '%s': "
564 				    "must be an integer\n", optarg);
565 				usage();
566 				return (1);
567 			}
568 			break;
569 		case 'm':
570 			domount = 1;
571 			break;
572 		case 'q':
573 			quiet = 1;
574 			break;
575 		case 'r':
576 			range = optarg;
577 			break;
578 		case 't':
579 			if ((type = name_to_type(optarg)) == TYPE_INVAL &&
580 			    !MOS_TYPE(type)) {
581 				(void) fprintf(stderr, "invalid type '%s'\n",
582 				    optarg);
583 				usage();
584 				return (1);
585 			}
586 			break;
587 		case 'u':
588 			flags |= ZINJECT_UNLOAD_SPA;
589 			break;
590 		case 'L':
591 			if ((label = name_to_type(optarg)) == TYPE_INVAL &&
592 			    !LABEL_TYPE(type)) {
593 				(void) fprintf(stderr, "invalid label type "
594 				    "'%s'\n", optarg);
595 				usage();
596 				return (1);
597 			}
598 			break;
599 		case ':':
600 			(void) fprintf(stderr, "option -%c requires an "
601 			    "operand\n", optopt);
602 			usage();
603 			return (1);
604 		case '?':
605 			(void) fprintf(stderr, "invalid option '%c'\n",
606 			    optopt);
607 			usage();
608 			return (2);
609 		}
610 	}
611 
612 	argc -= optind;
613 	argv += optind;
614 
615 	if (cancel != NULL) {
616 		/*
617 		 * '-c' is invalid with any other options.
618 		 */
619 		if (raw != NULL || range != NULL || type != TYPE_INVAL ||
620 		    level != 0) {
621 			(void) fprintf(stderr, "cancel (-c) incompatible with "
622 			    "any other options\n");
623 			usage();
624 			return (2);
625 		}
626 		if (argc != 0) {
627 			(void) fprintf(stderr, "extraneous argument to '-c'\n");
628 			usage();
629 			return (2);
630 		}
631 
632 		if (strcmp(cancel, "all") == 0) {
633 			return (cancel_all_handlers());
634 		} else {
635 			int id = (int)strtol(cancel, &end, 10);
636 			if (*end != '\0') {
637 				(void) fprintf(stderr, "invalid handle id '%s':"
638 				    " must be an integer or 'all'\n", cancel);
639 				usage();
640 				return (1);
641 			}
642 			return (cancel_handler(id));
643 		}
644 	}
645 
646 	if (device != NULL) {
647 		/*
648 		 * Device (-d) injection uses a completely different mechanism
649 		 * for doing injection, so handle it separately here.
650 		 */
651 		if (raw != NULL || range != NULL || type != TYPE_INVAL ||
652 		    level != 0) {
653 			(void) fprintf(stderr, "device (-d) incompatible with "
654 			    "data error injection\n");
655 			usage();
656 			return (2);
657 		}
658 
659 		if (argc != 1) {
660 			(void) fprintf(stderr, "device (-d) injection requires "
661 			    "a single pool name\n");
662 			usage();
663 			return (2);
664 		}
665 
666 		(void) strcpy(pool, argv[0]);
667 		dataset[0] = '\0';
668 
669 		if (error == ECKSUM) {
670 			(void) fprintf(stderr, "device error type must be "
671 			    "'io' or 'nxio'\n");
672 			return (1);
673 		}
674 
675 		if (translate_device(pool, device, label, &record) != 0)
676 			return (1);
677 		if (!error)
678 			error = ENXIO;
679 	} else if (raw != NULL) {
680 		if (range != NULL || type != TYPE_INVAL || level != 0) {
681 			(void) fprintf(stderr, "raw (-b) format with "
682 			    "any other options\n");
683 			usage();
684 			return (2);
685 		}
686 
687 		if (argc != 1) {
688 			(void) fprintf(stderr, "raw (-b) format expects a "
689 			    "single pool name\n");
690 			usage();
691 			return (2);
692 		}
693 
694 		(void) strcpy(pool, argv[0]);
695 		dataset[0] = '\0';
696 
697 		if (error == ENXIO) {
698 			(void) fprintf(stderr, "data error type must be "
699 			    "'checksum' or 'io'\n");
700 			return (1);
701 		}
702 
703 		if (translate_raw(raw, &record) != 0)
704 			return (1);
705 		if (!error)
706 			error = EIO;
707 	} else if (type == TYPE_INVAL) {
708 		if (flags == 0) {
709 			(void) fprintf(stderr, "at least one of '-b', '-d', "
710 			    "'-t', '-a', or '-u' must be specified\n");
711 			usage();
712 			return (2);
713 		}
714 
715 		if (argc == 1 && (flags & ZINJECT_UNLOAD_SPA)) {
716 			(void) strcpy(pool, argv[0]);
717 			dataset[0] = '\0';
718 		} else if (argc != 0) {
719 			(void) fprintf(stderr, "extraneous argument for "
720 			    "'-f'\n");
721 			usage();
722 			return (2);
723 		}
724 
725 		flags |= ZINJECT_NULL;
726 	} else {
727 		if (argc != 1) {
728 			(void) fprintf(stderr, "missing object\n");
729 			usage();
730 			return (2);
731 		}
732 
733 		if (error == ENXIO) {
734 			(void) fprintf(stderr, "data error type must be "
735 			    "'checksum' or 'io'\n");
736 			return (1);
737 		}
738 
739 		if (translate_record(type, argv[0], range, level, &record, pool,
740 		    dataset) != 0)
741 			return (1);
742 		if (!error)
743 			error = EIO;
744 	}
745 
746 	/*
747 	 * If this is pool-wide metadata, unmount everything.  The ioctl() will
748 	 * unload the pool, so that we trigger spa-wide reopen of metadata next
749 	 * time we access the pool.
750 	 */
751 	if (dataset[0] != '\0' && domount) {
752 		if ((zhp = zfs_open(g_zfs, dataset, ZFS_TYPE_DATASET)) == NULL)
753 			return (1);
754 
755 		if (zfs_unmount(zhp, NULL, 0) != 0)
756 			return (1);
757 	}
758 
759 	record.zi_error = error;
760 
761 	ret = register_handler(pool, flags, &record, quiet);
762 
763 	if (dataset[0] != '\0' && domount)
764 		ret = (zfs_mount(zhp, NULL, 0) != 0);
765 
766 	libzfs_fini(g_zfs);
767 
768 	return (ret);
769 }
770