xref: /titanic_52/usr/src/cmd/ztest/ztest.c (revision fc30d4661fdf50c4c69dacbc572af35439c28cd8)
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 (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
23  * Copyright (c) 2011, 2016 by Delphix. All rights reserved.
24  * Copyright 2011 Nexenta Systems, Inc.  All rights reserved.
25  * Copyright (c) 2013 Steven Hartland. All rights reserved.
26  * Copyright (c) 2014 Integros [integros.com]
27  * Copyright 2017 Joyent, Inc.
28  */
29 
30 /*
31  * The objective of this program is to provide a DMU/ZAP/SPA stress test
32  * that runs entirely in userland, is easy to use, and easy to extend.
33  *
34  * The overall design of the ztest program is as follows:
35  *
36  * (1) For each major functional area (e.g. adding vdevs to a pool,
37  *     creating and destroying datasets, reading and writing objects, etc)
38  *     we have a simple routine to test that functionality.  These
39  *     individual routines do not have to do anything "stressful".
40  *
41  * (2) We turn these simple functionality tests into a stress test by
42  *     running them all in parallel, with as many threads as desired,
43  *     and spread across as many datasets, objects, and vdevs as desired.
44  *
45  * (3) While all this is happening, we inject faults into the pool to
46  *     verify that self-healing data really works.
47  *
48  * (4) Every time we open a dataset, we change its checksum and compression
49  *     functions.  Thus even individual objects vary from block to block
50  *     in which checksum they use and whether they're compressed.
51  *
52  * (5) To verify that we never lose on-disk consistency after a crash,
53  *     we run the entire test in a child of the main process.
54  *     At random times, the child self-immolates with a SIGKILL.
55  *     This is the software equivalent of pulling the power cord.
56  *     The parent then runs the test again, using the existing
57  *     storage pool, as many times as desired. If backwards compatibility
58  *     testing is enabled ztest will sometimes run the "older" version
59  *     of ztest after a SIGKILL.
60  *
61  * (6) To verify that we don't have future leaks or temporal incursions,
62  *     many of the functional tests record the transaction group number
63  *     as part of their data.  When reading old data, they verify that
64  *     the transaction group number is less than the current, open txg.
65  *     If you add a new test, please do this if applicable.
66  *
67  * When run with no arguments, ztest runs for about five minutes and
68  * produces no output if successful.  To get a little bit of information,
69  * specify -V.  To get more information, specify -VV, and so on.
70  *
71  * To turn this into an overnight stress test, use -T to specify run time.
72  *
73  * You can ask more more vdevs [-v], datasets [-d], or threads [-t]
74  * to increase the pool capacity, fanout, and overall stress level.
75  *
76  * Use the -k option to set the desired frequency of kills.
77  *
78  * When ztest invokes itself it passes all relevant information through a
79  * temporary file which is mmap-ed in the child process. This allows shared
80  * memory to survive the exec syscall. The ztest_shared_hdr_t struct is always
81  * stored at offset 0 of this file and contains information on the size and
82  * number of shared structures in the file. The information stored in this file
83  * must remain backwards compatible with older versions of ztest so that
84  * ztest can invoke them during backwards compatibility testing (-B).
85  */
86 
87 #include <sys/zfs_context.h>
88 #include <sys/spa.h>
89 #include <sys/dmu.h>
90 #include <sys/txg.h>
91 #include <sys/dbuf.h>
92 #include <sys/zap.h>
93 #include <sys/dmu_objset.h>
94 #include <sys/poll.h>
95 #include <sys/stat.h>
96 #include <sys/time.h>
97 #include <sys/wait.h>
98 #include <sys/mman.h>
99 #include <sys/resource.h>
100 #include <sys/zio.h>
101 #include <sys/zil.h>
102 #include <sys/zil_impl.h>
103 #include <sys/vdev_impl.h>
104 #include <sys/vdev_file.h>
105 #include <sys/spa_impl.h>
106 #include <sys/metaslab_impl.h>
107 #include <sys/dsl_prop.h>
108 #include <sys/dsl_dataset.h>
109 #include <sys/dsl_destroy.h>
110 #include <sys/dsl_scan.h>
111 #include <sys/zio_checksum.h>
112 #include <sys/refcount.h>
113 #include <sys/zfeature.h>
114 #include <sys/dsl_userhold.h>
115 #include <stdio.h>
116 #include <stdio_ext.h>
117 #include <stdlib.h>
118 #include <unistd.h>
119 #include <signal.h>
120 #include <umem.h>
121 #include <dlfcn.h>
122 #include <ctype.h>
123 #include <math.h>
124 #include <sys/fs/zfs.h>
125 #include <libnvpair.h>
126 #include <libcmdutils.h>
127 
128 static int ztest_fd_data = -1;
129 static int ztest_fd_rand = -1;
130 
131 typedef struct ztest_shared_hdr {
132 	uint64_t	zh_hdr_size;
133 	uint64_t	zh_opts_size;
134 	uint64_t	zh_size;
135 	uint64_t	zh_stats_size;
136 	uint64_t	zh_stats_count;
137 	uint64_t	zh_ds_size;
138 	uint64_t	zh_ds_count;
139 } ztest_shared_hdr_t;
140 
141 static ztest_shared_hdr_t *ztest_shared_hdr;
142 
143 typedef struct ztest_shared_opts {
144 	char zo_pool[ZFS_MAX_DATASET_NAME_LEN];
145 	char zo_dir[ZFS_MAX_DATASET_NAME_LEN];
146 	char zo_alt_ztest[MAXNAMELEN];
147 	char zo_alt_libpath[MAXNAMELEN];
148 	uint64_t zo_vdevs;
149 	uint64_t zo_vdevtime;
150 	size_t zo_vdev_size;
151 	int zo_ashift;
152 	int zo_mirrors;
153 	int zo_raidz;
154 	int zo_raidz_parity;
155 	int zo_datasets;
156 	int zo_threads;
157 	uint64_t zo_passtime;
158 	uint64_t zo_killrate;
159 	int zo_verbose;
160 	int zo_init;
161 	uint64_t zo_time;
162 	uint64_t zo_maxloops;
163 	uint64_t zo_metaslab_gang_bang;
164 } ztest_shared_opts_t;
165 
166 static const ztest_shared_opts_t ztest_opts_defaults = {
167 	.zo_pool = { 'z', 't', 'e', 's', 't', '\0' },
168 	.zo_dir = { '/', 't', 'm', 'p', '\0' },
169 	.zo_alt_ztest = { '\0' },
170 	.zo_alt_libpath = { '\0' },
171 	.zo_vdevs = 5,
172 	.zo_ashift = SPA_MINBLOCKSHIFT,
173 	.zo_mirrors = 2,
174 	.zo_raidz = 4,
175 	.zo_raidz_parity = 1,
176 	.zo_vdev_size = SPA_MINDEVSIZE * 2,
177 	.zo_datasets = 7,
178 	.zo_threads = 23,
179 	.zo_passtime = 60,		/* 60 seconds */
180 	.zo_killrate = 70,		/* 70% kill rate */
181 	.zo_verbose = 0,
182 	.zo_init = 1,
183 	.zo_time = 300,			/* 5 minutes */
184 	.zo_maxloops = 50,		/* max loops during spa_freeze() */
185 	.zo_metaslab_gang_bang = 32 << 10
186 };
187 
188 extern uint64_t metaslab_gang_bang;
189 extern uint64_t metaslab_df_alloc_threshold;
190 extern uint64_t zfs_deadman_synctime_ms;
191 extern int metaslab_preload_limit;
192 
193 static ztest_shared_opts_t *ztest_shared_opts;
194 static ztest_shared_opts_t ztest_opts;
195 
196 typedef struct ztest_shared_ds {
197 	uint64_t	zd_seq;
198 } ztest_shared_ds_t;
199 
200 static ztest_shared_ds_t *ztest_shared_ds;
201 #define	ZTEST_GET_SHARED_DS(d) (&ztest_shared_ds[d])
202 
203 #define	BT_MAGIC	0x123456789abcdefULL
204 #define	MAXFAULTS() \
205 	(MAX(zs->zs_mirrors, 1) * (ztest_opts.zo_raidz_parity + 1) - 1)
206 
207 enum ztest_io_type {
208 	ZTEST_IO_WRITE_TAG,
209 	ZTEST_IO_WRITE_PATTERN,
210 	ZTEST_IO_WRITE_ZEROES,
211 	ZTEST_IO_TRUNCATE,
212 	ZTEST_IO_SETATTR,
213 	ZTEST_IO_REWRITE,
214 	ZTEST_IO_TYPES
215 };
216 
217 typedef struct ztest_block_tag {
218 	uint64_t	bt_magic;
219 	uint64_t	bt_objset;
220 	uint64_t	bt_object;
221 	uint64_t	bt_offset;
222 	uint64_t	bt_gen;
223 	uint64_t	bt_txg;
224 	uint64_t	bt_crtxg;
225 } ztest_block_tag_t;
226 
227 typedef struct bufwad {
228 	uint64_t	bw_index;
229 	uint64_t	bw_txg;
230 	uint64_t	bw_data;
231 } bufwad_t;
232 
233 /*
234  * XXX -- fix zfs range locks to be generic so we can use them here.
235  */
236 typedef enum {
237 	RL_READER,
238 	RL_WRITER,
239 	RL_APPEND
240 } rl_type_t;
241 
242 typedef struct rll {
243 	void		*rll_writer;
244 	int		rll_readers;
245 	mutex_t		rll_lock;
246 	cond_t		rll_cv;
247 } rll_t;
248 
249 typedef struct rl {
250 	uint64_t	rl_object;
251 	uint64_t	rl_offset;
252 	uint64_t	rl_size;
253 	rll_t		*rl_lock;
254 } rl_t;
255 
256 #define	ZTEST_RANGE_LOCKS	64
257 #define	ZTEST_OBJECT_LOCKS	64
258 
259 /*
260  * Object descriptor.  Used as a template for object lookup/create/remove.
261  */
262 typedef struct ztest_od {
263 	uint64_t	od_dir;
264 	uint64_t	od_object;
265 	dmu_object_type_t od_type;
266 	dmu_object_type_t od_crtype;
267 	uint64_t	od_blocksize;
268 	uint64_t	od_crblocksize;
269 	uint64_t	od_gen;
270 	uint64_t	od_crgen;
271 	char		od_name[ZFS_MAX_DATASET_NAME_LEN];
272 } ztest_od_t;
273 
274 /*
275  * Per-dataset state.
276  */
277 typedef struct ztest_ds {
278 	ztest_shared_ds_t *zd_shared;
279 	objset_t	*zd_os;
280 	rwlock_t	zd_zilog_lock;
281 	zilog_t		*zd_zilog;
282 	ztest_od_t	*zd_od;		/* debugging aid */
283 	char		zd_name[ZFS_MAX_DATASET_NAME_LEN];
284 	mutex_t		zd_dirobj_lock;
285 	rll_t		zd_object_lock[ZTEST_OBJECT_LOCKS];
286 	rll_t		zd_range_lock[ZTEST_RANGE_LOCKS];
287 } ztest_ds_t;
288 
289 /*
290  * Per-iteration state.
291  */
292 typedef void ztest_func_t(ztest_ds_t *zd, uint64_t id);
293 
294 typedef struct ztest_info {
295 	ztest_func_t	*zi_func;	/* test function */
296 	uint64_t	zi_iters;	/* iterations per execution */
297 	uint64_t	*zi_interval;	/* execute every <interval> seconds */
298 } ztest_info_t;
299 
300 typedef struct ztest_shared_callstate {
301 	uint64_t	zc_count;	/* per-pass count */
302 	uint64_t	zc_time;	/* per-pass time */
303 	uint64_t	zc_next;	/* next time to call this function */
304 } ztest_shared_callstate_t;
305 
306 static ztest_shared_callstate_t *ztest_shared_callstate;
307 #define	ZTEST_GET_SHARED_CALLSTATE(c) (&ztest_shared_callstate[c])
308 
309 /*
310  * Note: these aren't static because we want dladdr() to work.
311  */
312 ztest_func_t ztest_dmu_read_write;
313 ztest_func_t ztest_dmu_write_parallel;
314 ztest_func_t ztest_dmu_object_alloc_free;
315 ztest_func_t ztest_dmu_commit_callbacks;
316 ztest_func_t ztest_zap;
317 ztest_func_t ztest_zap_parallel;
318 ztest_func_t ztest_zil_commit;
319 ztest_func_t ztest_zil_remount;
320 ztest_func_t ztest_dmu_read_write_zcopy;
321 ztest_func_t ztest_dmu_objset_create_destroy;
322 ztest_func_t ztest_dmu_prealloc;
323 ztest_func_t ztest_fzap;
324 ztest_func_t ztest_dmu_snapshot_create_destroy;
325 ztest_func_t ztest_dsl_prop_get_set;
326 ztest_func_t ztest_spa_prop_get_set;
327 ztest_func_t ztest_spa_create_destroy;
328 ztest_func_t ztest_fault_inject;
329 ztest_func_t ztest_ddt_repair;
330 ztest_func_t ztest_dmu_snapshot_hold;
331 ztest_func_t ztest_spa_rename;
332 ztest_func_t ztest_scrub;
333 ztest_func_t ztest_dsl_dataset_promote_busy;
334 ztest_func_t ztest_vdev_attach_detach;
335 ztest_func_t ztest_vdev_LUN_growth;
336 ztest_func_t ztest_vdev_add_remove;
337 ztest_func_t ztest_vdev_aux_add_remove;
338 ztest_func_t ztest_split_pool;
339 ztest_func_t ztest_reguid;
340 ztest_func_t ztest_spa_upgrade;
341 
342 uint64_t zopt_always = 0ULL * NANOSEC;		/* all the time */
343 uint64_t zopt_incessant = 1ULL * NANOSEC / 10;	/* every 1/10 second */
344 uint64_t zopt_often = 1ULL * NANOSEC;		/* every second */
345 uint64_t zopt_sometimes = 10ULL * NANOSEC;	/* every 10 seconds */
346 uint64_t zopt_rarely = 60ULL * NANOSEC;		/* every 60 seconds */
347 
348 ztest_info_t ztest_info[] = {
349 	{ ztest_dmu_read_write,			1,	&zopt_always	},
350 	{ ztest_dmu_write_parallel,		10,	&zopt_always	},
351 	{ ztest_dmu_object_alloc_free,		1,	&zopt_always	},
352 	{ ztest_dmu_commit_callbacks,		1,	&zopt_always	},
353 	{ ztest_zap,				30,	&zopt_always	},
354 	{ ztest_zap_parallel,			100,	&zopt_always	},
355 	{ ztest_split_pool,			1,	&zopt_always	},
356 	{ ztest_zil_commit,			1,	&zopt_incessant	},
357 	{ ztest_zil_remount,			1,	&zopt_sometimes	},
358 	{ ztest_dmu_read_write_zcopy,		1,	&zopt_often	},
359 	{ ztest_dmu_objset_create_destroy,	1,	&zopt_often	},
360 	{ ztest_dsl_prop_get_set,		1,	&zopt_often	},
361 	{ ztest_spa_prop_get_set,		1,	&zopt_sometimes	},
362 #if 0
363 	{ ztest_dmu_prealloc,			1,	&zopt_sometimes	},
364 #endif
365 	{ ztest_fzap,				1,	&zopt_sometimes	},
366 	{ ztest_dmu_snapshot_create_destroy,	1,	&zopt_sometimes	},
367 	{ ztest_spa_create_destroy,		1,	&zopt_sometimes	},
368 	{ ztest_fault_inject,			1,	&zopt_sometimes	},
369 	{ ztest_ddt_repair,			1,	&zopt_sometimes	},
370 	{ ztest_dmu_snapshot_hold,		1,	&zopt_sometimes	},
371 	{ ztest_reguid,				1,	&zopt_rarely	},
372 	{ ztest_spa_rename,			1,	&zopt_rarely	},
373 	{ ztest_scrub,				1,	&zopt_rarely	},
374 	{ ztest_spa_upgrade,			1,	&zopt_rarely	},
375 	{ ztest_dsl_dataset_promote_busy,	1,	&zopt_rarely	},
376 	{ ztest_vdev_attach_detach,		1,	&zopt_sometimes	},
377 	{ ztest_vdev_LUN_growth,		1,	&zopt_rarely	},
378 	{ ztest_vdev_add_remove,		1,
379 	    &ztest_opts.zo_vdevtime				},
380 	{ ztest_vdev_aux_add_remove,		1,
381 	    &ztest_opts.zo_vdevtime				},
382 };
383 
384 #define	ZTEST_FUNCS	(sizeof (ztest_info) / sizeof (ztest_info_t))
385 
386 /*
387  * The following struct is used to hold a list of uncalled commit callbacks.
388  * The callbacks are ordered by txg number.
389  */
390 typedef struct ztest_cb_list {
391 	mutex_t	zcl_callbacks_lock;
392 	list_t	zcl_callbacks;
393 } ztest_cb_list_t;
394 
395 /*
396  * Stuff we need to share writably between parent and child.
397  */
398 typedef struct ztest_shared {
399 	boolean_t	zs_do_init;
400 	hrtime_t	zs_proc_start;
401 	hrtime_t	zs_proc_stop;
402 	hrtime_t	zs_thread_start;
403 	hrtime_t	zs_thread_stop;
404 	hrtime_t	zs_thread_kill;
405 	uint64_t	zs_enospc_count;
406 	uint64_t	zs_vdev_next_leaf;
407 	uint64_t	zs_vdev_aux;
408 	uint64_t	zs_alloc;
409 	uint64_t	zs_space;
410 	uint64_t	zs_splits;
411 	uint64_t	zs_mirrors;
412 	uint64_t	zs_metaslab_sz;
413 	uint64_t	zs_metaslab_df_alloc_threshold;
414 	uint64_t	zs_guid;
415 } ztest_shared_t;
416 
417 #define	ID_PARALLEL	-1ULL
418 
419 static char ztest_dev_template[] = "%s/%s.%llua";
420 static char ztest_aux_template[] = "%s/%s.%s.%llu";
421 ztest_shared_t *ztest_shared;
422 
423 static spa_t *ztest_spa = NULL;
424 static ztest_ds_t *ztest_ds;
425 
426 static mutex_t ztest_vdev_lock;
427 
428 /*
429  * The ztest_name_lock protects the pool and dataset namespace used by
430  * the individual tests. To modify the namespace, consumers must grab
431  * this lock as writer. Grabbing the lock as reader will ensure that the
432  * namespace does not change while the lock is held.
433  */
434 static rwlock_t ztest_name_lock;
435 
436 static boolean_t ztest_dump_core = B_TRUE;
437 static boolean_t ztest_exiting;
438 
439 /* Global commit callback list */
440 static ztest_cb_list_t zcl;
441 
442 enum ztest_object {
443 	ZTEST_META_DNODE = 0,
444 	ZTEST_DIROBJ,
445 	ZTEST_OBJECTS
446 };
447 
448 static void usage(boolean_t) __NORETURN;
449 
450 /*
451  * These libumem hooks provide a reasonable set of defaults for the allocator's
452  * debugging facilities.
453  */
454 const char *
455 _umem_debug_init()
456 {
457 	return ("default,verbose"); /* $UMEM_DEBUG setting */
458 }
459 
460 const char *
461 _umem_logging_init(void)
462 {
463 	return ("fail,contents"); /* $UMEM_LOGGING setting */
464 }
465 
466 #define	FATAL_MSG_SZ	1024
467 
468 char *fatal_msg;
469 
470 static void
471 fatal(int do_perror, char *message, ...)
472 {
473 	va_list args;
474 	int save_errno = errno;
475 	char buf[FATAL_MSG_SZ];
476 
477 	(void) fflush(stdout);
478 
479 	va_start(args, message);
480 	(void) sprintf(buf, "ztest: ");
481 	/* LINTED */
482 	(void) vsprintf(buf + strlen(buf), message, args);
483 	va_end(args);
484 	if (do_perror) {
485 		(void) snprintf(buf + strlen(buf), FATAL_MSG_SZ - strlen(buf),
486 		    ": %s", strerror(save_errno));
487 	}
488 	(void) fprintf(stderr, "%s\n", buf);
489 	fatal_msg = buf;			/* to ease debugging */
490 	if (ztest_dump_core)
491 		abort();
492 	exit(3);
493 }
494 
495 static int
496 str2shift(const char *buf)
497 {
498 	const char *ends = "BKMGTPEZ";
499 	int i;
500 
501 	if (buf[0] == '\0')
502 		return (0);
503 	for (i = 0; i < strlen(ends); i++) {
504 		if (toupper(buf[0]) == ends[i])
505 			break;
506 	}
507 	if (i == strlen(ends)) {
508 		(void) fprintf(stderr, "ztest: invalid bytes suffix: %s\n",
509 		    buf);
510 		usage(B_FALSE);
511 	}
512 	if (buf[1] == '\0' || (toupper(buf[1]) == 'B' && buf[2] == '\0')) {
513 		return (10*i);
514 	}
515 	(void) fprintf(stderr, "ztest: invalid bytes suffix: %s\n", buf);
516 	usage(B_FALSE);
517 	/* NOTREACHED */
518 }
519 
520 static uint64_t
521 nicenumtoull(const char *buf)
522 {
523 	char *end;
524 	uint64_t val;
525 
526 	val = strtoull(buf, &end, 0);
527 	if (end == buf) {
528 		(void) fprintf(stderr, "ztest: bad numeric value: %s\n", buf);
529 		usage(B_FALSE);
530 	} else if (end[0] == '.') {
531 		double fval = strtod(buf, &end);
532 		fval *= pow(2, str2shift(end));
533 		if (fval > UINT64_MAX) {
534 			(void) fprintf(stderr, "ztest: value too large: %s\n",
535 			    buf);
536 			usage(B_FALSE);
537 		}
538 		val = (uint64_t)fval;
539 	} else {
540 		int shift = str2shift(end);
541 		if (shift >= 64 || (val << shift) >> shift != val) {
542 			(void) fprintf(stderr, "ztest: value too large: %s\n",
543 			    buf);
544 			usage(B_FALSE);
545 		}
546 		val <<= shift;
547 	}
548 	return (val);
549 }
550 
551 static void
552 usage(boolean_t requested)
553 {
554 	const ztest_shared_opts_t *zo = &ztest_opts_defaults;
555 
556 	char nice_vdev_size[NN_NUMBUF_SZ];
557 	char nice_gang_bang[NN_NUMBUF_SZ];
558 	FILE *fp = requested ? stdout : stderr;
559 
560 	nicenum(zo->zo_vdev_size, nice_vdev_size, sizeof (nice_vdev_size));
561 	nicenum(zo->zo_metaslab_gang_bang, nice_gang_bang,
562 	    sizeof (nice_gang_bang));
563 
564 	(void) fprintf(fp, "Usage: %s\n"
565 	    "\t[-v vdevs (default: %llu)]\n"
566 	    "\t[-s size_of_each_vdev (default: %s)]\n"
567 	    "\t[-a alignment_shift (default: %d)] use 0 for random\n"
568 	    "\t[-m mirror_copies (default: %d)]\n"
569 	    "\t[-r raidz_disks (default: %d)]\n"
570 	    "\t[-R raidz_parity (default: %d)]\n"
571 	    "\t[-d datasets (default: %d)]\n"
572 	    "\t[-t threads (default: %d)]\n"
573 	    "\t[-g gang_block_threshold (default: %s)]\n"
574 	    "\t[-i init_count (default: %d)] initialize pool i times\n"
575 	    "\t[-k kill_percentage (default: %llu%%)]\n"
576 	    "\t[-p pool_name (default: %s)]\n"
577 	    "\t[-f dir (default: %s)] file directory for vdev files\n"
578 	    "\t[-V] verbose (use multiple times for ever more blather)\n"
579 	    "\t[-E] use existing pool instead of creating new one\n"
580 	    "\t[-T time (default: %llu sec)] total run time\n"
581 	    "\t[-F freezeloops (default: %llu)] max loops in spa_freeze()\n"
582 	    "\t[-P passtime (default: %llu sec)] time per pass\n"
583 	    "\t[-B alt_ztest (default: <none>)] alternate ztest path\n"
584 	    "\t[-h] (print help)\n"
585 	    "",
586 	    zo->zo_pool,
587 	    (u_longlong_t)zo->zo_vdevs,			/* -v */
588 	    nice_vdev_size,				/* -s */
589 	    zo->zo_ashift,				/* -a */
590 	    zo->zo_mirrors,				/* -m */
591 	    zo->zo_raidz,				/* -r */
592 	    zo->zo_raidz_parity,			/* -R */
593 	    zo->zo_datasets,				/* -d */
594 	    zo->zo_threads,				/* -t */
595 	    nice_gang_bang,				/* -g */
596 	    zo->zo_init,				/* -i */
597 	    (u_longlong_t)zo->zo_killrate,		/* -k */
598 	    zo->zo_pool,				/* -p */
599 	    zo->zo_dir,					/* -f */
600 	    (u_longlong_t)zo->zo_time,			/* -T */
601 	    (u_longlong_t)zo->zo_maxloops,		/* -F */
602 	    (u_longlong_t)zo->zo_passtime);
603 	exit(requested ? 0 : 1);
604 }
605 
606 static void
607 process_options(int argc, char **argv)
608 {
609 	char *path;
610 	ztest_shared_opts_t *zo = &ztest_opts;
611 
612 	int opt;
613 	uint64_t value;
614 	char altdir[MAXNAMELEN] = { 0 };
615 
616 	bcopy(&ztest_opts_defaults, zo, sizeof (*zo));
617 
618 	while ((opt = getopt(argc, argv,
619 	    "v:s:a:m:r:R:d:t:g:i:k:p:f:VET:P:hF:B:")) != EOF) {
620 		value = 0;
621 		switch (opt) {
622 		case 'v':
623 		case 's':
624 		case 'a':
625 		case 'm':
626 		case 'r':
627 		case 'R':
628 		case 'd':
629 		case 't':
630 		case 'g':
631 		case 'i':
632 		case 'k':
633 		case 'T':
634 		case 'P':
635 		case 'F':
636 			value = nicenumtoull(optarg);
637 		}
638 		switch (opt) {
639 		case 'v':
640 			zo->zo_vdevs = value;
641 			break;
642 		case 's':
643 			zo->zo_vdev_size = MAX(SPA_MINDEVSIZE, value);
644 			break;
645 		case 'a':
646 			zo->zo_ashift = value;
647 			break;
648 		case 'm':
649 			zo->zo_mirrors = value;
650 			break;
651 		case 'r':
652 			zo->zo_raidz = MAX(1, value);
653 			break;
654 		case 'R':
655 			zo->zo_raidz_parity = MIN(MAX(value, 1), 3);
656 			break;
657 		case 'd':
658 			zo->zo_datasets = MAX(1, value);
659 			break;
660 		case 't':
661 			zo->zo_threads = MAX(1, value);
662 			break;
663 		case 'g':
664 			zo->zo_metaslab_gang_bang = MAX(SPA_MINBLOCKSIZE << 1,
665 			    value);
666 			break;
667 		case 'i':
668 			zo->zo_init = value;
669 			break;
670 		case 'k':
671 			zo->zo_killrate = value;
672 			break;
673 		case 'p':
674 			(void) strlcpy(zo->zo_pool, optarg,
675 			    sizeof (zo->zo_pool));
676 			break;
677 		case 'f':
678 			path = realpath(optarg, NULL);
679 			if (path == NULL) {
680 				(void) fprintf(stderr, "error: %s: %s\n",
681 				    optarg, strerror(errno));
682 				usage(B_FALSE);
683 			} else {
684 				(void) strlcpy(zo->zo_dir, path,
685 				    sizeof (zo->zo_dir));
686 			}
687 			break;
688 		case 'V':
689 			zo->zo_verbose++;
690 			break;
691 		case 'E':
692 			zo->zo_init = 0;
693 			break;
694 		case 'T':
695 			zo->zo_time = value;
696 			break;
697 		case 'P':
698 			zo->zo_passtime = MAX(1, value);
699 			break;
700 		case 'F':
701 			zo->zo_maxloops = MAX(1, value);
702 			break;
703 		case 'B':
704 			(void) strlcpy(altdir, optarg, sizeof (altdir));
705 			break;
706 		case 'h':
707 			usage(B_TRUE);
708 			break;
709 		case '?':
710 		default:
711 			usage(B_FALSE);
712 			break;
713 		}
714 	}
715 
716 	zo->zo_raidz_parity = MIN(zo->zo_raidz_parity, zo->zo_raidz - 1);
717 
718 	zo->zo_vdevtime =
719 	    (zo->zo_vdevs > 0 ? zo->zo_time * NANOSEC / zo->zo_vdevs :
720 	    UINT64_MAX >> 2);
721 
722 	if (strlen(altdir) > 0) {
723 		char *cmd;
724 		char *realaltdir;
725 		char *bin;
726 		char *ztest;
727 		char *isa;
728 		int isalen;
729 
730 		cmd = umem_alloc(MAXPATHLEN, UMEM_NOFAIL);
731 		realaltdir = umem_alloc(MAXPATHLEN, UMEM_NOFAIL);
732 
733 		VERIFY(NULL != realpath(getexecname(), cmd));
734 		if (0 != access(altdir, F_OK)) {
735 			ztest_dump_core = B_FALSE;
736 			fatal(B_TRUE, "invalid alternate ztest path: %s",
737 			    altdir);
738 		}
739 		VERIFY(NULL != realpath(altdir, realaltdir));
740 
741 		/*
742 		 * 'cmd' should be of the form "<anything>/usr/bin/<isa>/ztest".
743 		 * We want to extract <isa> to determine if we should use
744 		 * 32 or 64 bit binaries.
745 		 */
746 		bin = strstr(cmd, "/usr/bin/");
747 		ztest = strstr(bin, "/ztest");
748 		isa = bin + 9;
749 		isalen = ztest - isa;
750 		(void) snprintf(zo->zo_alt_ztest, sizeof (zo->zo_alt_ztest),
751 		    "%s/usr/bin/%.*s/ztest", realaltdir, isalen, isa);
752 		(void) snprintf(zo->zo_alt_libpath, sizeof (zo->zo_alt_libpath),
753 		    "%s/usr/lib/%.*s", realaltdir, isalen, isa);
754 
755 		if (0 != access(zo->zo_alt_ztest, X_OK)) {
756 			ztest_dump_core = B_FALSE;
757 			fatal(B_TRUE, "invalid alternate ztest: %s",
758 			    zo->zo_alt_ztest);
759 		} else if (0 != access(zo->zo_alt_libpath, X_OK)) {
760 			ztest_dump_core = B_FALSE;
761 			fatal(B_TRUE, "invalid alternate lib directory %s",
762 			    zo->zo_alt_libpath);
763 		}
764 
765 		umem_free(cmd, MAXPATHLEN);
766 		umem_free(realaltdir, MAXPATHLEN);
767 	}
768 }
769 
770 static void
771 ztest_kill(ztest_shared_t *zs)
772 {
773 	zs->zs_alloc = metaslab_class_get_alloc(spa_normal_class(ztest_spa));
774 	zs->zs_space = metaslab_class_get_space(spa_normal_class(ztest_spa));
775 
776 	/*
777 	 * Before we kill off ztest, make sure that the config is updated.
778 	 * See comment above spa_config_sync().
779 	 */
780 	mutex_enter(&spa_namespace_lock);
781 	spa_config_sync(ztest_spa, B_FALSE, B_FALSE);
782 	mutex_exit(&spa_namespace_lock);
783 
784 	zfs_dbgmsg_print(FTAG);
785 	(void) kill(getpid(), SIGKILL);
786 }
787 
788 static uint64_t
789 ztest_random(uint64_t range)
790 {
791 	uint64_t r;
792 
793 	ASSERT3S(ztest_fd_rand, >=, 0);
794 
795 	if (range == 0)
796 		return (0);
797 
798 	if (read(ztest_fd_rand, &r, sizeof (r)) != sizeof (r))
799 		fatal(1, "short read from /dev/urandom");
800 
801 	return (r % range);
802 }
803 
804 /* ARGSUSED */
805 static void
806 ztest_record_enospc(const char *s)
807 {
808 	ztest_shared->zs_enospc_count++;
809 }
810 
811 static uint64_t
812 ztest_get_ashift(void)
813 {
814 	if (ztest_opts.zo_ashift == 0)
815 		return (SPA_MINBLOCKSHIFT + ztest_random(5));
816 	return (ztest_opts.zo_ashift);
817 }
818 
819 static nvlist_t *
820 make_vdev_file(char *path, char *aux, char *pool, size_t size, uint64_t ashift)
821 {
822 	char pathbuf[MAXPATHLEN];
823 	uint64_t vdev;
824 	nvlist_t *file;
825 
826 	if (ashift == 0)
827 		ashift = ztest_get_ashift();
828 
829 	if (path == NULL) {
830 		path = pathbuf;
831 
832 		if (aux != NULL) {
833 			vdev = ztest_shared->zs_vdev_aux;
834 			(void) snprintf(path, sizeof (pathbuf),
835 			    ztest_aux_template, ztest_opts.zo_dir,
836 			    pool == NULL ? ztest_opts.zo_pool : pool,
837 			    aux, vdev);
838 		} else {
839 			vdev = ztest_shared->zs_vdev_next_leaf++;
840 			(void) snprintf(path, sizeof (pathbuf),
841 			    ztest_dev_template, ztest_opts.zo_dir,
842 			    pool == NULL ? ztest_opts.zo_pool : pool, vdev);
843 		}
844 	}
845 
846 	if (size != 0) {
847 		int fd = open(path, O_RDWR | O_CREAT | O_TRUNC, 0666);
848 		if (fd == -1)
849 			fatal(1, "can't open %s", path);
850 		if (ftruncate(fd, size) != 0)
851 			fatal(1, "can't ftruncate %s", path);
852 		(void) close(fd);
853 	}
854 
855 	VERIFY(nvlist_alloc(&file, NV_UNIQUE_NAME, 0) == 0);
856 	VERIFY(nvlist_add_string(file, ZPOOL_CONFIG_TYPE, VDEV_TYPE_FILE) == 0);
857 	VERIFY(nvlist_add_string(file, ZPOOL_CONFIG_PATH, path) == 0);
858 	VERIFY(nvlist_add_uint64(file, ZPOOL_CONFIG_ASHIFT, ashift) == 0);
859 
860 	return (file);
861 }
862 
863 static nvlist_t *
864 make_vdev_raidz(char *path, char *aux, char *pool, size_t size,
865     uint64_t ashift, int r)
866 {
867 	nvlist_t *raidz, **child;
868 	int c;
869 
870 	if (r < 2)
871 		return (make_vdev_file(path, aux, pool, size, ashift));
872 	child = umem_alloc(r * sizeof (nvlist_t *), UMEM_NOFAIL);
873 
874 	for (c = 0; c < r; c++)
875 		child[c] = make_vdev_file(path, aux, pool, size, ashift);
876 
877 	VERIFY(nvlist_alloc(&raidz, NV_UNIQUE_NAME, 0) == 0);
878 	VERIFY(nvlist_add_string(raidz, ZPOOL_CONFIG_TYPE,
879 	    VDEV_TYPE_RAIDZ) == 0);
880 	VERIFY(nvlist_add_uint64(raidz, ZPOOL_CONFIG_NPARITY,
881 	    ztest_opts.zo_raidz_parity) == 0);
882 	VERIFY(nvlist_add_nvlist_array(raidz, ZPOOL_CONFIG_CHILDREN,
883 	    child, r) == 0);
884 
885 	for (c = 0; c < r; c++)
886 		nvlist_free(child[c]);
887 
888 	umem_free(child, r * sizeof (nvlist_t *));
889 
890 	return (raidz);
891 }
892 
893 static nvlist_t *
894 make_vdev_mirror(char *path, char *aux, char *pool, size_t size,
895     uint64_t ashift, int r, int m)
896 {
897 	nvlist_t *mirror, **child;
898 	int c;
899 
900 	if (m < 1)
901 		return (make_vdev_raidz(path, aux, pool, size, ashift, r));
902 
903 	child = umem_alloc(m * sizeof (nvlist_t *), UMEM_NOFAIL);
904 
905 	for (c = 0; c < m; c++)
906 		child[c] = make_vdev_raidz(path, aux, pool, size, ashift, r);
907 
908 	VERIFY(nvlist_alloc(&mirror, NV_UNIQUE_NAME, 0) == 0);
909 	VERIFY(nvlist_add_string(mirror, ZPOOL_CONFIG_TYPE,
910 	    VDEV_TYPE_MIRROR) == 0);
911 	VERIFY(nvlist_add_nvlist_array(mirror, ZPOOL_CONFIG_CHILDREN,
912 	    child, m) == 0);
913 
914 	for (c = 0; c < m; c++)
915 		nvlist_free(child[c]);
916 
917 	umem_free(child, m * sizeof (nvlist_t *));
918 
919 	return (mirror);
920 }
921 
922 static nvlist_t *
923 make_vdev_root(char *path, char *aux, char *pool, size_t size, uint64_t ashift,
924     int log, int r, int m, int t)
925 {
926 	nvlist_t *root, **child;
927 	int c;
928 
929 	ASSERT(t > 0);
930 
931 	child = umem_alloc(t * sizeof (nvlist_t *), UMEM_NOFAIL);
932 
933 	for (c = 0; c < t; c++) {
934 		child[c] = make_vdev_mirror(path, aux, pool, size, ashift,
935 		    r, m);
936 		VERIFY(nvlist_add_uint64(child[c], ZPOOL_CONFIG_IS_LOG,
937 		    log) == 0);
938 	}
939 
940 	VERIFY(nvlist_alloc(&root, NV_UNIQUE_NAME, 0) == 0);
941 	VERIFY(nvlist_add_string(root, ZPOOL_CONFIG_TYPE, VDEV_TYPE_ROOT) == 0);
942 	VERIFY(nvlist_add_nvlist_array(root, aux ? aux : ZPOOL_CONFIG_CHILDREN,
943 	    child, t) == 0);
944 
945 	for (c = 0; c < t; c++)
946 		nvlist_free(child[c]);
947 
948 	umem_free(child, t * sizeof (nvlist_t *));
949 
950 	return (root);
951 }
952 
953 /*
954  * Find a random spa version. Returns back a random spa version in the
955  * range [initial_version, SPA_VERSION_FEATURES].
956  */
957 static uint64_t
958 ztest_random_spa_version(uint64_t initial_version)
959 {
960 	uint64_t version = initial_version;
961 
962 	if (version <= SPA_VERSION_BEFORE_FEATURES) {
963 		version = version +
964 		    ztest_random(SPA_VERSION_BEFORE_FEATURES - version + 1);
965 	}
966 
967 	if (version > SPA_VERSION_BEFORE_FEATURES)
968 		version = SPA_VERSION_FEATURES;
969 
970 	ASSERT(SPA_VERSION_IS_SUPPORTED(version));
971 	return (version);
972 }
973 
974 static int
975 ztest_random_blocksize(void)
976 {
977 	uint64_t block_shift;
978 	/*
979 	 * Choose a block size >= the ashift.
980 	 * If the SPA supports new MAXBLOCKSIZE, test up to 1MB blocks.
981 	 */
982 	int maxbs = SPA_OLD_MAXBLOCKSHIFT;
983 	if (spa_maxblocksize(ztest_spa) == SPA_MAXBLOCKSIZE)
984 		maxbs = 20;
985 	block_shift = ztest_random(maxbs - ztest_spa->spa_max_ashift + 1);
986 	return (1 << (SPA_MINBLOCKSHIFT + block_shift));
987 }
988 
989 static int
990 ztest_random_ibshift(void)
991 {
992 	return (DN_MIN_INDBLKSHIFT +
993 	    ztest_random(DN_MAX_INDBLKSHIFT - DN_MIN_INDBLKSHIFT + 1));
994 }
995 
996 static uint64_t
997 ztest_random_vdev_top(spa_t *spa, boolean_t log_ok)
998 {
999 	uint64_t top;
1000 	vdev_t *rvd = spa->spa_root_vdev;
1001 	vdev_t *tvd;
1002 
1003 	ASSERT(spa_config_held(spa, SCL_ALL, RW_READER) != 0);
1004 
1005 	do {
1006 		top = ztest_random(rvd->vdev_children);
1007 		tvd = rvd->vdev_child[top];
1008 	} while (tvd->vdev_ishole || (tvd->vdev_islog && !log_ok) ||
1009 	    tvd->vdev_mg == NULL || tvd->vdev_mg->mg_class == NULL);
1010 
1011 	return (top);
1012 }
1013 
1014 static uint64_t
1015 ztest_random_dsl_prop(zfs_prop_t prop)
1016 {
1017 	uint64_t value;
1018 
1019 	do {
1020 		value = zfs_prop_random_value(prop, ztest_random(-1ULL));
1021 	} while (prop == ZFS_PROP_CHECKSUM && value == ZIO_CHECKSUM_OFF);
1022 
1023 	return (value);
1024 }
1025 
1026 static int
1027 ztest_dsl_prop_set_uint64(char *osname, zfs_prop_t prop, uint64_t value,
1028     boolean_t inherit)
1029 {
1030 	const char *propname = zfs_prop_to_name(prop);
1031 	const char *valname;
1032 	char setpoint[MAXPATHLEN];
1033 	uint64_t curval;
1034 	int error;
1035 
1036 	error = dsl_prop_set_int(osname, propname,
1037 	    (inherit ? ZPROP_SRC_NONE : ZPROP_SRC_LOCAL), value);
1038 
1039 	if (error == ENOSPC) {
1040 		ztest_record_enospc(FTAG);
1041 		return (error);
1042 	}
1043 	ASSERT0(error);
1044 
1045 	VERIFY0(dsl_prop_get_integer(osname, propname, &curval, setpoint));
1046 
1047 	if (ztest_opts.zo_verbose >= 6) {
1048 		VERIFY(zfs_prop_index_to_string(prop, curval, &valname) == 0);
1049 		(void) printf("%s %s = %s at '%s'\n",
1050 		    osname, propname, valname, setpoint);
1051 	}
1052 
1053 	return (error);
1054 }
1055 
1056 static int
1057 ztest_spa_prop_set_uint64(zpool_prop_t prop, uint64_t value)
1058 {
1059 	spa_t *spa = ztest_spa;
1060 	nvlist_t *props = NULL;
1061 	int error;
1062 
1063 	VERIFY(nvlist_alloc(&props, NV_UNIQUE_NAME, 0) == 0);
1064 	VERIFY(nvlist_add_uint64(props, zpool_prop_to_name(prop), value) == 0);
1065 
1066 	error = spa_prop_set(spa, props);
1067 
1068 	nvlist_free(props);
1069 
1070 	if (error == ENOSPC) {
1071 		ztest_record_enospc(FTAG);
1072 		return (error);
1073 	}
1074 	ASSERT0(error);
1075 
1076 	return (error);
1077 }
1078 
1079 static void
1080 ztest_rll_init(rll_t *rll)
1081 {
1082 	rll->rll_writer = NULL;
1083 	rll->rll_readers = 0;
1084 	VERIFY(_mutex_init(&rll->rll_lock, USYNC_THREAD, NULL) == 0);
1085 	VERIFY(cond_init(&rll->rll_cv, USYNC_THREAD, NULL) == 0);
1086 }
1087 
1088 static void
1089 ztest_rll_destroy(rll_t *rll)
1090 {
1091 	ASSERT(rll->rll_writer == NULL);
1092 	ASSERT(rll->rll_readers == 0);
1093 	VERIFY(_mutex_destroy(&rll->rll_lock) == 0);
1094 	VERIFY(cond_destroy(&rll->rll_cv) == 0);
1095 }
1096 
1097 static void
1098 ztest_rll_lock(rll_t *rll, rl_type_t type)
1099 {
1100 	VERIFY(mutex_lock(&rll->rll_lock) == 0);
1101 
1102 	if (type == RL_READER) {
1103 		while (rll->rll_writer != NULL)
1104 			(void) cond_wait(&rll->rll_cv, &rll->rll_lock);
1105 		rll->rll_readers++;
1106 	} else {
1107 		while (rll->rll_writer != NULL || rll->rll_readers)
1108 			(void) cond_wait(&rll->rll_cv, &rll->rll_lock);
1109 		rll->rll_writer = curthread;
1110 	}
1111 
1112 	VERIFY(mutex_unlock(&rll->rll_lock) == 0);
1113 }
1114 
1115 static void
1116 ztest_rll_unlock(rll_t *rll)
1117 {
1118 	VERIFY(mutex_lock(&rll->rll_lock) == 0);
1119 
1120 	if (rll->rll_writer) {
1121 		ASSERT(rll->rll_readers == 0);
1122 		rll->rll_writer = NULL;
1123 	} else {
1124 		ASSERT(rll->rll_readers != 0);
1125 		ASSERT(rll->rll_writer == NULL);
1126 		rll->rll_readers--;
1127 	}
1128 
1129 	if (rll->rll_writer == NULL && rll->rll_readers == 0)
1130 		VERIFY(cond_broadcast(&rll->rll_cv) == 0);
1131 
1132 	VERIFY(mutex_unlock(&rll->rll_lock) == 0);
1133 }
1134 
1135 static void
1136 ztest_object_lock(ztest_ds_t *zd, uint64_t object, rl_type_t type)
1137 {
1138 	rll_t *rll = &zd->zd_object_lock[object & (ZTEST_OBJECT_LOCKS - 1)];
1139 
1140 	ztest_rll_lock(rll, type);
1141 }
1142 
1143 static void
1144 ztest_object_unlock(ztest_ds_t *zd, uint64_t object)
1145 {
1146 	rll_t *rll = &zd->zd_object_lock[object & (ZTEST_OBJECT_LOCKS - 1)];
1147 
1148 	ztest_rll_unlock(rll);
1149 }
1150 
1151 static rl_t *
1152 ztest_range_lock(ztest_ds_t *zd, uint64_t object, uint64_t offset,
1153     uint64_t size, rl_type_t type)
1154 {
1155 	uint64_t hash = object ^ (offset % (ZTEST_RANGE_LOCKS + 1));
1156 	rll_t *rll = &zd->zd_range_lock[hash & (ZTEST_RANGE_LOCKS - 1)];
1157 	rl_t *rl;
1158 
1159 	rl = umem_alloc(sizeof (*rl), UMEM_NOFAIL);
1160 	rl->rl_object = object;
1161 	rl->rl_offset = offset;
1162 	rl->rl_size = size;
1163 	rl->rl_lock = rll;
1164 
1165 	ztest_rll_lock(rll, type);
1166 
1167 	return (rl);
1168 }
1169 
1170 static void
1171 ztest_range_unlock(rl_t *rl)
1172 {
1173 	rll_t *rll = rl->rl_lock;
1174 
1175 	ztest_rll_unlock(rll);
1176 
1177 	umem_free(rl, sizeof (*rl));
1178 }
1179 
1180 static void
1181 ztest_zd_init(ztest_ds_t *zd, ztest_shared_ds_t *szd, objset_t *os)
1182 {
1183 	zd->zd_os = os;
1184 	zd->zd_zilog = dmu_objset_zil(os);
1185 	zd->zd_shared = szd;
1186 	dmu_objset_name(os, zd->zd_name);
1187 
1188 	if (zd->zd_shared != NULL)
1189 		zd->zd_shared->zd_seq = 0;
1190 
1191 	VERIFY(rwlock_init(&zd->zd_zilog_lock, USYNC_THREAD, NULL) == 0);
1192 	VERIFY(_mutex_init(&zd->zd_dirobj_lock, USYNC_THREAD, NULL) == 0);
1193 
1194 	for (int l = 0; l < ZTEST_OBJECT_LOCKS; l++)
1195 		ztest_rll_init(&zd->zd_object_lock[l]);
1196 
1197 	for (int l = 0; l < ZTEST_RANGE_LOCKS; l++)
1198 		ztest_rll_init(&zd->zd_range_lock[l]);
1199 }
1200 
1201 static void
1202 ztest_zd_fini(ztest_ds_t *zd)
1203 {
1204 	VERIFY(_mutex_destroy(&zd->zd_dirobj_lock) == 0);
1205 
1206 	for (int l = 0; l < ZTEST_OBJECT_LOCKS; l++)
1207 		ztest_rll_destroy(&zd->zd_object_lock[l]);
1208 
1209 	for (int l = 0; l < ZTEST_RANGE_LOCKS; l++)
1210 		ztest_rll_destroy(&zd->zd_range_lock[l]);
1211 }
1212 
1213 #define	TXG_MIGHTWAIT	(ztest_random(10) == 0 ? TXG_NOWAIT : TXG_WAIT)
1214 
1215 static uint64_t
1216 ztest_tx_assign(dmu_tx_t *tx, uint64_t txg_how, const char *tag)
1217 {
1218 	uint64_t txg;
1219 	int error;
1220 
1221 	/*
1222 	 * Attempt to assign tx to some transaction group.
1223 	 */
1224 	error = dmu_tx_assign(tx, txg_how);
1225 	if (error) {
1226 		if (error == ERESTART) {
1227 			ASSERT(txg_how == TXG_NOWAIT);
1228 			dmu_tx_wait(tx);
1229 		} else {
1230 			ASSERT3U(error, ==, ENOSPC);
1231 			ztest_record_enospc(tag);
1232 		}
1233 		dmu_tx_abort(tx);
1234 		return (0);
1235 	}
1236 	txg = dmu_tx_get_txg(tx);
1237 	ASSERT(txg != 0);
1238 	return (txg);
1239 }
1240 
1241 static void
1242 ztest_pattern_set(void *buf, uint64_t size, uint64_t value)
1243 {
1244 	uint64_t *ip = buf;
1245 	uint64_t *ip_end = (uint64_t *)((uintptr_t)buf + (uintptr_t)size);
1246 
1247 	while (ip < ip_end)
1248 		*ip++ = value;
1249 }
1250 
1251 static boolean_t
1252 ztest_pattern_match(void *buf, uint64_t size, uint64_t value)
1253 {
1254 	uint64_t *ip = buf;
1255 	uint64_t *ip_end = (uint64_t *)((uintptr_t)buf + (uintptr_t)size);
1256 	uint64_t diff = 0;
1257 
1258 	while (ip < ip_end)
1259 		diff |= (value - *ip++);
1260 
1261 	return (diff == 0);
1262 }
1263 
1264 static void
1265 ztest_bt_generate(ztest_block_tag_t *bt, objset_t *os, uint64_t object,
1266     uint64_t offset, uint64_t gen, uint64_t txg, uint64_t crtxg)
1267 {
1268 	bt->bt_magic = BT_MAGIC;
1269 	bt->bt_objset = dmu_objset_id(os);
1270 	bt->bt_object = object;
1271 	bt->bt_offset = offset;
1272 	bt->bt_gen = gen;
1273 	bt->bt_txg = txg;
1274 	bt->bt_crtxg = crtxg;
1275 }
1276 
1277 static void
1278 ztest_bt_verify(ztest_block_tag_t *bt, objset_t *os, uint64_t object,
1279     uint64_t offset, uint64_t gen, uint64_t txg, uint64_t crtxg)
1280 {
1281 	ASSERT3U(bt->bt_magic, ==, BT_MAGIC);
1282 	ASSERT3U(bt->bt_objset, ==, dmu_objset_id(os));
1283 	ASSERT3U(bt->bt_object, ==, object);
1284 	ASSERT3U(bt->bt_offset, ==, offset);
1285 	ASSERT3U(bt->bt_gen, <=, gen);
1286 	ASSERT3U(bt->bt_txg, <=, txg);
1287 	ASSERT3U(bt->bt_crtxg, ==, crtxg);
1288 }
1289 
1290 static ztest_block_tag_t *
1291 ztest_bt_bonus(dmu_buf_t *db)
1292 {
1293 	dmu_object_info_t doi;
1294 	ztest_block_tag_t *bt;
1295 
1296 	dmu_object_info_from_db(db, &doi);
1297 	ASSERT3U(doi.doi_bonus_size, <=, db->db_size);
1298 	ASSERT3U(doi.doi_bonus_size, >=, sizeof (*bt));
1299 	bt = (void *)((char *)db->db_data + doi.doi_bonus_size - sizeof (*bt));
1300 
1301 	return (bt);
1302 }
1303 
1304 /*
1305  * ZIL logging ops
1306  */
1307 
1308 #define	lrz_type	lr_mode
1309 #define	lrz_blocksize	lr_uid
1310 #define	lrz_ibshift	lr_gid
1311 #define	lrz_bonustype	lr_rdev
1312 #define	lrz_bonuslen	lr_crtime[1]
1313 
1314 static void
1315 ztest_log_create(ztest_ds_t *zd, dmu_tx_t *tx, lr_create_t *lr)
1316 {
1317 	char *name = (void *)(lr + 1);		/* name follows lr */
1318 	size_t namesize = strlen(name) + 1;
1319 	itx_t *itx;
1320 
1321 	if (zil_replaying(zd->zd_zilog, tx))
1322 		return;
1323 
1324 	itx = zil_itx_create(TX_CREATE, sizeof (*lr) + namesize);
1325 	bcopy(&lr->lr_common + 1, &itx->itx_lr + 1,
1326 	    sizeof (*lr) + namesize - sizeof (lr_t));
1327 
1328 	zil_itx_assign(zd->zd_zilog, itx, tx);
1329 }
1330 
1331 static void
1332 ztest_log_remove(ztest_ds_t *zd, dmu_tx_t *tx, lr_remove_t *lr, uint64_t object)
1333 {
1334 	char *name = (void *)(lr + 1);		/* name follows lr */
1335 	size_t namesize = strlen(name) + 1;
1336 	itx_t *itx;
1337 
1338 	if (zil_replaying(zd->zd_zilog, tx))
1339 		return;
1340 
1341 	itx = zil_itx_create(TX_REMOVE, sizeof (*lr) + namesize);
1342 	bcopy(&lr->lr_common + 1, &itx->itx_lr + 1,
1343 	    sizeof (*lr) + namesize - sizeof (lr_t));
1344 
1345 	itx->itx_oid = object;
1346 	zil_itx_assign(zd->zd_zilog, itx, tx);
1347 }
1348 
1349 static void
1350 ztest_log_write(ztest_ds_t *zd, dmu_tx_t *tx, lr_write_t *lr)
1351 {
1352 	itx_t *itx;
1353 	itx_wr_state_t write_state = ztest_random(WR_NUM_STATES);
1354 
1355 	if (zil_replaying(zd->zd_zilog, tx))
1356 		return;
1357 
1358 	if (lr->lr_length > ZIL_MAX_LOG_DATA)
1359 		write_state = WR_INDIRECT;
1360 
1361 	itx = zil_itx_create(TX_WRITE,
1362 	    sizeof (*lr) + (write_state == WR_COPIED ? lr->lr_length : 0));
1363 
1364 	if (write_state == WR_COPIED &&
1365 	    dmu_read(zd->zd_os, lr->lr_foid, lr->lr_offset, lr->lr_length,
1366 	    ((lr_write_t *)&itx->itx_lr) + 1, DMU_READ_NO_PREFETCH) != 0) {
1367 		zil_itx_destroy(itx);
1368 		itx = zil_itx_create(TX_WRITE, sizeof (*lr));
1369 		write_state = WR_NEED_COPY;
1370 	}
1371 	itx->itx_private = zd;
1372 	itx->itx_wr_state = write_state;
1373 	itx->itx_sync = (ztest_random(8) == 0);
1374 	itx->itx_sod += (write_state == WR_NEED_COPY ? lr->lr_length : 0);
1375 
1376 	bcopy(&lr->lr_common + 1, &itx->itx_lr + 1,
1377 	    sizeof (*lr) - sizeof (lr_t));
1378 
1379 	zil_itx_assign(zd->zd_zilog, itx, tx);
1380 }
1381 
1382 static void
1383 ztest_log_truncate(ztest_ds_t *zd, dmu_tx_t *tx, lr_truncate_t *lr)
1384 {
1385 	itx_t *itx;
1386 
1387 	if (zil_replaying(zd->zd_zilog, tx))
1388 		return;
1389 
1390 	itx = zil_itx_create(TX_TRUNCATE, sizeof (*lr));
1391 	bcopy(&lr->lr_common + 1, &itx->itx_lr + 1,
1392 	    sizeof (*lr) - sizeof (lr_t));
1393 
1394 	itx->itx_sync = B_FALSE;
1395 	zil_itx_assign(zd->zd_zilog, itx, tx);
1396 }
1397 
1398 static void
1399 ztest_log_setattr(ztest_ds_t *zd, dmu_tx_t *tx, lr_setattr_t *lr)
1400 {
1401 	itx_t *itx;
1402 
1403 	if (zil_replaying(zd->zd_zilog, tx))
1404 		return;
1405 
1406 	itx = zil_itx_create(TX_SETATTR, sizeof (*lr));
1407 	bcopy(&lr->lr_common + 1, &itx->itx_lr + 1,
1408 	    sizeof (*lr) - sizeof (lr_t));
1409 
1410 	itx->itx_sync = B_FALSE;
1411 	zil_itx_assign(zd->zd_zilog, itx, tx);
1412 }
1413 
1414 /*
1415  * ZIL replay ops
1416  */
1417 static int
1418 ztest_replay_create(ztest_ds_t *zd, lr_create_t *lr, boolean_t byteswap)
1419 {
1420 	char *name = (void *)(lr + 1);		/* name follows lr */
1421 	objset_t *os = zd->zd_os;
1422 	ztest_block_tag_t *bbt;
1423 	dmu_buf_t *db;
1424 	dmu_tx_t *tx;
1425 	uint64_t txg;
1426 	int error = 0;
1427 
1428 	if (byteswap)
1429 		byteswap_uint64_array(lr, sizeof (*lr));
1430 
1431 	ASSERT(lr->lr_doid == ZTEST_DIROBJ);
1432 	ASSERT(name[0] != '\0');
1433 
1434 	tx = dmu_tx_create(os);
1435 
1436 	dmu_tx_hold_zap(tx, lr->lr_doid, B_TRUE, name);
1437 
1438 	if (lr->lrz_type == DMU_OT_ZAP_OTHER) {
1439 		dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, B_TRUE, NULL);
1440 	} else {
1441 		dmu_tx_hold_bonus(tx, DMU_NEW_OBJECT);
1442 	}
1443 
1444 	txg = ztest_tx_assign(tx, TXG_WAIT, FTAG);
1445 	if (txg == 0)
1446 		return (ENOSPC);
1447 
1448 	ASSERT(dmu_objset_zil(os)->zl_replay == !!lr->lr_foid);
1449 
1450 	if (lr->lrz_type == DMU_OT_ZAP_OTHER) {
1451 		if (lr->lr_foid == 0) {
1452 			lr->lr_foid = zap_create(os,
1453 			    lr->lrz_type, lr->lrz_bonustype,
1454 			    lr->lrz_bonuslen, tx);
1455 		} else {
1456 			error = zap_create_claim(os, lr->lr_foid,
1457 			    lr->lrz_type, lr->lrz_bonustype,
1458 			    lr->lrz_bonuslen, tx);
1459 		}
1460 	} else {
1461 		if (lr->lr_foid == 0) {
1462 			lr->lr_foid = dmu_object_alloc(os,
1463 			    lr->lrz_type, 0, lr->lrz_bonustype,
1464 			    lr->lrz_bonuslen, tx);
1465 		} else {
1466 			error = dmu_object_claim(os, lr->lr_foid,
1467 			    lr->lrz_type, 0, lr->lrz_bonustype,
1468 			    lr->lrz_bonuslen, tx);
1469 		}
1470 	}
1471 
1472 	if (error) {
1473 		ASSERT3U(error, ==, EEXIST);
1474 		ASSERT(zd->zd_zilog->zl_replay);
1475 		dmu_tx_commit(tx);
1476 		return (error);
1477 	}
1478 
1479 	ASSERT(lr->lr_foid != 0);
1480 
1481 	if (lr->lrz_type != DMU_OT_ZAP_OTHER)
1482 		VERIFY3U(0, ==, dmu_object_set_blocksize(os, lr->lr_foid,
1483 		    lr->lrz_blocksize, lr->lrz_ibshift, tx));
1484 
1485 	VERIFY3U(0, ==, dmu_bonus_hold(os, lr->lr_foid, FTAG, &db));
1486 	bbt = ztest_bt_bonus(db);
1487 	dmu_buf_will_dirty(db, tx);
1488 	ztest_bt_generate(bbt, os, lr->lr_foid, -1ULL, lr->lr_gen, txg, txg);
1489 	dmu_buf_rele(db, FTAG);
1490 
1491 	VERIFY3U(0, ==, zap_add(os, lr->lr_doid, name, sizeof (uint64_t), 1,
1492 	    &lr->lr_foid, tx));
1493 
1494 	(void) ztest_log_create(zd, tx, lr);
1495 
1496 	dmu_tx_commit(tx);
1497 
1498 	return (0);
1499 }
1500 
1501 static int
1502 ztest_replay_remove(ztest_ds_t *zd, lr_remove_t *lr, boolean_t byteswap)
1503 {
1504 	char *name = (void *)(lr + 1);		/* name follows lr */
1505 	objset_t *os = zd->zd_os;
1506 	dmu_object_info_t doi;
1507 	dmu_tx_t *tx;
1508 	uint64_t object, txg;
1509 
1510 	if (byteswap)
1511 		byteswap_uint64_array(lr, sizeof (*lr));
1512 
1513 	ASSERT(lr->lr_doid == ZTEST_DIROBJ);
1514 	ASSERT(name[0] != '\0');
1515 
1516 	VERIFY3U(0, ==,
1517 	    zap_lookup(os, lr->lr_doid, name, sizeof (object), 1, &object));
1518 	ASSERT(object != 0);
1519 
1520 	ztest_object_lock(zd, object, RL_WRITER);
1521 
1522 	VERIFY3U(0, ==, dmu_object_info(os, object, &doi));
1523 
1524 	tx = dmu_tx_create(os);
1525 
1526 	dmu_tx_hold_zap(tx, lr->lr_doid, B_FALSE, name);
1527 	dmu_tx_hold_free(tx, object, 0, DMU_OBJECT_END);
1528 
1529 	txg = ztest_tx_assign(tx, TXG_WAIT, FTAG);
1530 	if (txg == 0) {
1531 		ztest_object_unlock(zd, object);
1532 		return (ENOSPC);
1533 	}
1534 
1535 	if (doi.doi_type == DMU_OT_ZAP_OTHER) {
1536 		VERIFY3U(0, ==, zap_destroy(os, object, tx));
1537 	} else {
1538 		VERIFY3U(0, ==, dmu_object_free(os, object, tx));
1539 	}
1540 
1541 	VERIFY3U(0, ==, zap_remove(os, lr->lr_doid, name, tx));
1542 
1543 	(void) ztest_log_remove(zd, tx, lr, object);
1544 
1545 	dmu_tx_commit(tx);
1546 
1547 	ztest_object_unlock(zd, object);
1548 
1549 	return (0);
1550 }
1551 
1552 static int
1553 ztest_replay_write(ztest_ds_t *zd, lr_write_t *lr, boolean_t byteswap)
1554 {
1555 	objset_t *os = zd->zd_os;
1556 	void *data = lr + 1;			/* data follows lr */
1557 	uint64_t offset, length;
1558 	ztest_block_tag_t *bt = data;
1559 	ztest_block_tag_t *bbt;
1560 	uint64_t gen, txg, lrtxg, crtxg;
1561 	dmu_object_info_t doi;
1562 	dmu_tx_t *tx;
1563 	dmu_buf_t *db;
1564 	arc_buf_t *abuf = NULL;
1565 	rl_t *rl;
1566 
1567 	if (byteswap)
1568 		byteswap_uint64_array(lr, sizeof (*lr));
1569 
1570 	offset = lr->lr_offset;
1571 	length = lr->lr_length;
1572 
1573 	/* If it's a dmu_sync() block, write the whole block */
1574 	if (lr->lr_common.lrc_reclen == sizeof (lr_write_t)) {
1575 		uint64_t blocksize = BP_GET_LSIZE(&lr->lr_blkptr);
1576 		if (length < blocksize) {
1577 			offset -= offset % blocksize;
1578 			length = blocksize;
1579 		}
1580 	}
1581 
1582 	if (bt->bt_magic == BSWAP_64(BT_MAGIC))
1583 		byteswap_uint64_array(bt, sizeof (*bt));
1584 
1585 	if (bt->bt_magic != BT_MAGIC)
1586 		bt = NULL;
1587 
1588 	ztest_object_lock(zd, lr->lr_foid, RL_READER);
1589 	rl = ztest_range_lock(zd, lr->lr_foid, offset, length, RL_WRITER);
1590 
1591 	VERIFY3U(0, ==, dmu_bonus_hold(os, lr->lr_foid, FTAG, &db));
1592 
1593 	dmu_object_info_from_db(db, &doi);
1594 
1595 	bbt = ztest_bt_bonus(db);
1596 	ASSERT3U(bbt->bt_magic, ==, BT_MAGIC);
1597 	gen = bbt->bt_gen;
1598 	crtxg = bbt->bt_crtxg;
1599 	lrtxg = lr->lr_common.lrc_txg;
1600 
1601 	tx = dmu_tx_create(os);
1602 
1603 	dmu_tx_hold_write(tx, lr->lr_foid, offset, length);
1604 
1605 	if (ztest_random(8) == 0 && length == doi.doi_data_block_size &&
1606 	    P2PHASE(offset, length) == 0)
1607 		abuf = dmu_request_arcbuf(db, length);
1608 
1609 	txg = ztest_tx_assign(tx, TXG_WAIT, FTAG);
1610 	if (txg == 0) {
1611 		if (abuf != NULL)
1612 			dmu_return_arcbuf(abuf);
1613 		dmu_buf_rele(db, FTAG);
1614 		ztest_range_unlock(rl);
1615 		ztest_object_unlock(zd, lr->lr_foid);
1616 		return (ENOSPC);
1617 	}
1618 
1619 	if (bt != NULL) {
1620 		/*
1621 		 * Usually, verify the old data before writing new data --
1622 		 * but not always, because we also want to verify correct
1623 		 * behavior when the data was not recently read into cache.
1624 		 */
1625 		ASSERT(offset % doi.doi_data_block_size == 0);
1626 		if (ztest_random(4) != 0) {
1627 			int prefetch = ztest_random(2) ?
1628 			    DMU_READ_PREFETCH : DMU_READ_NO_PREFETCH;
1629 			ztest_block_tag_t rbt;
1630 
1631 			VERIFY(dmu_read(os, lr->lr_foid, offset,
1632 			    sizeof (rbt), &rbt, prefetch) == 0);
1633 			if (rbt.bt_magic == BT_MAGIC) {
1634 				ztest_bt_verify(&rbt, os, lr->lr_foid,
1635 				    offset, gen, txg, crtxg);
1636 			}
1637 		}
1638 
1639 		/*
1640 		 * Writes can appear to be newer than the bonus buffer because
1641 		 * the ztest_get_data() callback does a dmu_read() of the
1642 		 * open-context data, which may be different than the data
1643 		 * as it was when the write was generated.
1644 		 */
1645 		if (zd->zd_zilog->zl_replay) {
1646 			ztest_bt_verify(bt, os, lr->lr_foid, offset,
1647 			    MAX(gen, bt->bt_gen), MAX(txg, lrtxg),
1648 			    bt->bt_crtxg);
1649 		}
1650 
1651 		/*
1652 		 * Set the bt's gen/txg to the bonus buffer's gen/txg
1653 		 * so that all of the usual ASSERTs will work.
1654 		 */
1655 		ztest_bt_generate(bt, os, lr->lr_foid, offset, gen, txg, crtxg);
1656 	}
1657 
1658 	if (abuf == NULL) {
1659 		dmu_write(os, lr->lr_foid, offset, length, data, tx);
1660 	} else {
1661 		bcopy(data, abuf->b_data, length);
1662 		dmu_assign_arcbuf(db, offset, abuf, tx);
1663 	}
1664 
1665 	(void) ztest_log_write(zd, tx, lr);
1666 
1667 	dmu_buf_rele(db, FTAG);
1668 
1669 	dmu_tx_commit(tx);
1670 
1671 	ztest_range_unlock(rl);
1672 	ztest_object_unlock(zd, lr->lr_foid);
1673 
1674 	return (0);
1675 }
1676 
1677 static int
1678 ztest_replay_truncate(ztest_ds_t *zd, lr_truncate_t *lr, boolean_t byteswap)
1679 {
1680 	objset_t *os = zd->zd_os;
1681 	dmu_tx_t *tx;
1682 	uint64_t txg;
1683 	rl_t *rl;
1684 
1685 	if (byteswap)
1686 		byteswap_uint64_array(lr, sizeof (*lr));
1687 
1688 	ztest_object_lock(zd, lr->lr_foid, RL_READER);
1689 	rl = ztest_range_lock(zd, lr->lr_foid, lr->lr_offset, lr->lr_length,
1690 	    RL_WRITER);
1691 
1692 	tx = dmu_tx_create(os);
1693 
1694 	dmu_tx_hold_free(tx, lr->lr_foid, lr->lr_offset, lr->lr_length);
1695 
1696 	txg = ztest_tx_assign(tx, TXG_WAIT, FTAG);
1697 	if (txg == 0) {
1698 		ztest_range_unlock(rl);
1699 		ztest_object_unlock(zd, lr->lr_foid);
1700 		return (ENOSPC);
1701 	}
1702 
1703 	VERIFY(dmu_free_range(os, lr->lr_foid, lr->lr_offset,
1704 	    lr->lr_length, tx) == 0);
1705 
1706 	(void) ztest_log_truncate(zd, tx, lr);
1707 
1708 	dmu_tx_commit(tx);
1709 
1710 	ztest_range_unlock(rl);
1711 	ztest_object_unlock(zd, lr->lr_foid);
1712 
1713 	return (0);
1714 }
1715 
1716 static int
1717 ztest_replay_setattr(ztest_ds_t *zd, lr_setattr_t *lr, boolean_t byteswap)
1718 {
1719 	objset_t *os = zd->zd_os;
1720 	dmu_tx_t *tx;
1721 	dmu_buf_t *db;
1722 	ztest_block_tag_t *bbt;
1723 	uint64_t txg, lrtxg, crtxg;
1724 
1725 	if (byteswap)
1726 		byteswap_uint64_array(lr, sizeof (*lr));
1727 
1728 	ztest_object_lock(zd, lr->lr_foid, RL_WRITER);
1729 
1730 	VERIFY3U(0, ==, dmu_bonus_hold(os, lr->lr_foid, FTAG, &db));
1731 
1732 	tx = dmu_tx_create(os);
1733 	dmu_tx_hold_bonus(tx, lr->lr_foid);
1734 
1735 	txg = ztest_tx_assign(tx, TXG_WAIT, FTAG);
1736 	if (txg == 0) {
1737 		dmu_buf_rele(db, FTAG);
1738 		ztest_object_unlock(zd, lr->lr_foid);
1739 		return (ENOSPC);
1740 	}
1741 
1742 	bbt = ztest_bt_bonus(db);
1743 	ASSERT3U(bbt->bt_magic, ==, BT_MAGIC);
1744 	crtxg = bbt->bt_crtxg;
1745 	lrtxg = lr->lr_common.lrc_txg;
1746 
1747 	if (zd->zd_zilog->zl_replay) {
1748 		ASSERT(lr->lr_size != 0);
1749 		ASSERT(lr->lr_mode != 0);
1750 		ASSERT(lrtxg != 0);
1751 	} else {
1752 		/*
1753 		 * Randomly change the size and increment the generation.
1754 		 */
1755 		lr->lr_size = (ztest_random(db->db_size / sizeof (*bbt)) + 1) *
1756 		    sizeof (*bbt);
1757 		lr->lr_mode = bbt->bt_gen + 1;
1758 		ASSERT(lrtxg == 0);
1759 	}
1760 
1761 	/*
1762 	 * Verify that the current bonus buffer is not newer than our txg.
1763 	 */
1764 	ztest_bt_verify(bbt, os, lr->lr_foid, -1ULL, lr->lr_mode,
1765 	    MAX(txg, lrtxg), crtxg);
1766 
1767 	dmu_buf_will_dirty(db, tx);
1768 
1769 	ASSERT3U(lr->lr_size, >=, sizeof (*bbt));
1770 	ASSERT3U(lr->lr_size, <=, db->db_size);
1771 	VERIFY0(dmu_set_bonus(db, lr->lr_size, tx));
1772 	bbt = ztest_bt_bonus(db);
1773 
1774 	ztest_bt_generate(bbt, os, lr->lr_foid, -1ULL, lr->lr_mode, txg, crtxg);
1775 
1776 	dmu_buf_rele(db, FTAG);
1777 
1778 	(void) ztest_log_setattr(zd, tx, lr);
1779 
1780 	dmu_tx_commit(tx);
1781 
1782 	ztest_object_unlock(zd, lr->lr_foid);
1783 
1784 	return (0);
1785 }
1786 
1787 zil_replay_func_t *ztest_replay_vector[TX_MAX_TYPE] = {
1788 	NULL,			/* 0 no such transaction type */
1789 	ztest_replay_create,	/* TX_CREATE */
1790 	NULL,			/* TX_MKDIR */
1791 	NULL,			/* TX_MKXATTR */
1792 	NULL,			/* TX_SYMLINK */
1793 	ztest_replay_remove,	/* TX_REMOVE */
1794 	NULL,			/* TX_RMDIR */
1795 	NULL,			/* TX_LINK */
1796 	NULL,			/* TX_RENAME */
1797 	ztest_replay_write,	/* TX_WRITE */
1798 	ztest_replay_truncate,	/* TX_TRUNCATE */
1799 	ztest_replay_setattr,	/* TX_SETATTR */
1800 	NULL,			/* TX_ACL */
1801 	NULL,			/* TX_CREATE_ACL */
1802 	NULL,			/* TX_CREATE_ATTR */
1803 	NULL,			/* TX_CREATE_ACL_ATTR */
1804 	NULL,			/* TX_MKDIR_ACL */
1805 	NULL,			/* TX_MKDIR_ATTR */
1806 	NULL,			/* TX_MKDIR_ACL_ATTR */
1807 	NULL,			/* TX_WRITE2 */
1808 };
1809 
1810 /*
1811  * ZIL get_data callbacks
1812  */
1813 
1814 static void
1815 ztest_get_done(zgd_t *zgd, int error)
1816 {
1817 	ztest_ds_t *zd = zgd->zgd_private;
1818 	uint64_t object = zgd->zgd_rl->rl_object;
1819 
1820 	if (zgd->zgd_db)
1821 		dmu_buf_rele(zgd->zgd_db, zgd);
1822 
1823 	ztest_range_unlock(zgd->zgd_rl);
1824 	ztest_object_unlock(zd, object);
1825 
1826 	if (error == 0 && zgd->zgd_bp)
1827 		zil_add_block(zgd->zgd_zilog, zgd->zgd_bp);
1828 
1829 	umem_free(zgd, sizeof (*zgd));
1830 }
1831 
1832 static int
1833 ztest_get_data(void *arg, lr_write_t *lr, char *buf, zio_t *zio)
1834 {
1835 	ztest_ds_t *zd = arg;
1836 	objset_t *os = zd->zd_os;
1837 	uint64_t object = lr->lr_foid;
1838 	uint64_t offset = lr->lr_offset;
1839 	uint64_t size = lr->lr_length;
1840 	blkptr_t *bp = &lr->lr_blkptr;
1841 	uint64_t txg = lr->lr_common.lrc_txg;
1842 	uint64_t crtxg;
1843 	dmu_object_info_t doi;
1844 	dmu_buf_t *db;
1845 	zgd_t *zgd;
1846 	int error;
1847 
1848 	ztest_object_lock(zd, object, RL_READER);
1849 	error = dmu_bonus_hold(os, object, FTAG, &db);
1850 	if (error) {
1851 		ztest_object_unlock(zd, object);
1852 		return (error);
1853 	}
1854 
1855 	crtxg = ztest_bt_bonus(db)->bt_crtxg;
1856 
1857 	if (crtxg == 0 || crtxg > txg) {
1858 		dmu_buf_rele(db, FTAG);
1859 		ztest_object_unlock(zd, object);
1860 		return (ENOENT);
1861 	}
1862 
1863 	dmu_object_info_from_db(db, &doi);
1864 	dmu_buf_rele(db, FTAG);
1865 	db = NULL;
1866 
1867 	zgd = umem_zalloc(sizeof (*zgd), UMEM_NOFAIL);
1868 	zgd->zgd_zilog = zd->zd_zilog;
1869 	zgd->zgd_private = zd;
1870 
1871 	if (buf != NULL) {	/* immediate write */
1872 		zgd->zgd_rl = ztest_range_lock(zd, object, offset, size,
1873 		    RL_READER);
1874 
1875 		error = dmu_read(os, object, offset, size, buf,
1876 		    DMU_READ_NO_PREFETCH);
1877 		ASSERT(error == 0);
1878 	} else {
1879 		size = doi.doi_data_block_size;
1880 		if (ISP2(size)) {
1881 			offset = P2ALIGN(offset, size);
1882 		} else {
1883 			ASSERT(offset < size);
1884 			offset = 0;
1885 		}
1886 
1887 		zgd->zgd_rl = ztest_range_lock(zd, object, offset, size,
1888 		    RL_READER);
1889 
1890 		error = dmu_buf_hold(os, object, offset, zgd, &db,
1891 		    DMU_READ_NO_PREFETCH);
1892 
1893 		if (error == 0) {
1894 			blkptr_t *obp = dmu_buf_get_blkptr(db);
1895 			if (obp) {
1896 				ASSERT(BP_IS_HOLE(bp));
1897 				*bp = *obp;
1898 			}
1899 
1900 			zgd->zgd_db = db;
1901 			zgd->zgd_bp = bp;
1902 
1903 			ASSERT(db->db_offset == offset);
1904 			ASSERT(db->db_size == size);
1905 
1906 			error = dmu_sync(zio, lr->lr_common.lrc_txg,
1907 			    ztest_get_done, zgd);
1908 
1909 			if (error == 0)
1910 				return (0);
1911 		}
1912 	}
1913 
1914 	ztest_get_done(zgd, error);
1915 
1916 	return (error);
1917 }
1918 
1919 static void *
1920 ztest_lr_alloc(size_t lrsize, char *name)
1921 {
1922 	char *lr;
1923 	size_t namesize = name ? strlen(name) + 1 : 0;
1924 
1925 	lr = umem_zalloc(lrsize + namesize, UMEM_NOFAIL);
1926 
1927 	if (name)
1928 		bcopy(name, lr + lrsize, namesize);
1929 
1930 	return (lr);
1931 }
1932 
1933 void
1934 ztest_lr_free(void *lr, size_t lrsize, char *name)
1935 {
1936 	size_t namesize = name ? strlen(name) + 1 : 0;
1937 
1938 	umem_free(lr, lrsize + namesize);
1939 }
1940 
1941 /*
1942  * Lookup a bunch of objects.  Returns the number of objects not found.
1943  */
1944 static int
1945 ztest_lookup(ztest_ds_t *zd, ztest_od_t *od, int count)
1946 {
1947 	int missing = 0;
1948 	int error;
1949 
1950 	ASSERT(_mutex_held(&zd->zd_dirobj_lock));
1951 
1952 	for (int i = 0; i < count; i++, od++) {
1953 		od->od_object = 0;
1954 		error = zap_lookup(zd->zd_os, od->od_dir, od->od_name,
1955 		    sizeof (uint64_t), 1, &od->od_object);
1956 		if (error) {
1957 			ASSERT(error == ENOENT);
1958 			ASSERT(od->od_object == 0);
1959 			missing++;
1960 		} else {
1961 			dmu_buf_t *db;
1962 			ztest_block_tag_t *bbt;
1963 			dmu_object_info_t doi;
1964 
1965 			ASSERT(od->od_object != 0);
1966 			ASSERT(missing == 0);	/* there should be no gaps */
1967 
1968 			ztest_object_lock(zd, od->od_object, RL_READER);
1969 			VERIFY3U(0, ==, dmu_bonus_hold(zd->zd_os,
1970 			    od->od_object, FTAG, &db));
1971 			dmu_object_info_from_db(db, &doi);
1972 			bbt = ztest_bt_bonus(db);
1973 			ASSERT3U(bbt->bt_magic, ==, BT_MAGIC);
1974 			od->od_type = doi.doi_type;
1975 			od->od_blocksize = doi.doi_data_block_size;
1976 			od->od_gen = bbt->bt_gen;
1977 			dmu_buf_rele(db, FTAG);
1978 			ztest_object_unlock(zd, od->od_object);
1979 		}
1980 	}
1981 
1982 	return (missing);
1983 }
1984 
1985 static int
1986 ztest_create(ztest_ds_t *zd, ztest_od_t *od, int count)
1987 {
1988 	int missing = 0;
1989 
1990 	ASSERT(_mutex_held(&zd->zd_dirobj_lock));
1991 
1992 	for (int i = 0; i < count; i++, od++) {
1993 		if (missing) {
1994 			od->od_object = 0;
1995 			missing++;
1996 			continue;
1997 		}
1998 
1999 		lr_create_t *lr = ztest_lr_alloc(sizeof (*lr), od->od_name);
2000 
2001 		lr->lr_doid = od->od_dir;
2002 		lr->lr_foid = 0;	/* 0 to allocate, > 0 to claim */
2003 		lr->lrz_type = od->od_crtype;
2004 		lr->lrz_blocksize = od->od_crblocksize;
2005 		lr->lrz_ibshift = ztest_random_ibshift();
2006 		lr->lrz_bonustype = DMU_OT_UINT64_OTHER;
2007 		lr->lrz_bonuslen = dmu_bonus_max();
2008 		lr->lr_gen = od->od_crgen;
2009 		lr->lr_crtime[0] = time(NULL);
2010 
2011 		if (ztest_replay_create(zd, lr, B_FALSE) != 0) {
2012 			ASSERT(missing == 0);
2013 			od->od_object = 0;
2014 			missing++;
2015 		} else {
2016 			od->od_object = lr->lr_foid;
2017 			od->od_type = od->od_crtype;
2018 			od->od_blocksize = od->od_crblocksize;
2019 			od->od_gen = od->od_crgen;
2020 			ASSERT(od->od_object != 0);
2021 		}
2022 
2023 		ztest_lr_free(lr, sizeof (*lr), od->od_name);
2024 	}
2025 
2026 	return (missing);
2027 }
2028 
2029 static int
2030 ztest_remove(ztest_ds_t *zd, ztest_od_t *od, int count)
2031 {
2032 	int missing = 0;
2033 	int error;
2034 
2035 	ASSERT(_mutex_held(&zd->zd_dirobj_lock));
2036 
2037 	od += count - 1;
2038 
2039 	for (int i = count - 1; i >= 0; i--, od--) {
2040 		if (missing) {
2041 			missing++;
2042 			continue;
2043 		}
2044 
2045 		/*
2046 		 * No object was found.
2047 		 */
2048 		if (od->od_object == 0)
2049 			continue;
2050 
2051 		lr_remove_t *lr = ztest_lr_alloc(sizeof (*lr), od->od_name);
2052 
2053 		lr->lr_doid = od->od_dir;
2054 
2055 		if ((error = ztest_replay_remove(zd, lr, B_FALSE)) != 0) {
2056 			ASSERT3U(error, ==, ENOSPC);
2057 			missing++;
2058 		} else {
2059 			od->od_object = 0;
2060 		}
2061 		ztest_lr_free(lr, sizeof (*lr), od->od_name);
2062 	}
2063 
2064 	return (missing);
2065 }
2066 
2067 static int
2068 ztest_write(ztest_ds_t *zd, uint64_t object, uint64_t offset, uint64_t size,
2069     void *data)
2070 {
2071 	lr_write_t *lr;
2072 	int error;
2073 
2074 	lr = ztest_lr_alloc(sizeof (*lr) + size, NULL);
2075 
2076 	lr->lr_foid = object;
2077 	lr->lr_offset = offset;
2078 	lr->lr_length = size;
2079 	lr->lr_blkoff = 0;
2080 	BP_ZERO(&lr->lr_blkptr);
2081 
2082 	bcopy(data, lr + 1, size);
2083 
2084 	error = ztest_replay_write(zd, lr, B_FALSE);
2085 
2086 	ztest_lr_free(lr, sizeof (*lr) + size, NULL);
2087 
2088 	return (error);
2089 }
2090 
2091 static int
2092 ztest_truncate(ztest_ds_t *zd, uint64_t object, uint64_t offset, uint64_t size)
2093 {
2094 	lr_truncate_t *lr;
2095 	int error;
2096 
2097 	lr = ztest_lr_alloc(sizeof (*lr), NULL);
2098 
2099 	lr->lr_foid = object;
2100 	lr->lr_offset = offset;
2101 	lr->lr_length = size;
2102 
2103 	error = ztest_replay_truncate(zd, lr, B_FALSE);
2104 
2105 	ztest_lr_free(lr, sizeof (*lr), NULL);
2106 
2107 	return (error);
2108 }
2109 
2110 static int
2111 ztest_setattr(ztest_ds_t *zd, uint64_t object)
2112 {
2113 	lr_setattr_t *lr;
2114 	int error;
2115 
2116 	lr = ztest_lr_alloc(sizeof (*lr), NULL);
2117 
2118 	lr->lr_foid = object;
2119 	lr->lr_size = 0;
2120 	lr->lr_mode = 0;
2121 
2122 	error = ztest_replay_setattr(zd, lr, B_FALSE);
2123 
2124 	ztest_lr_free(lr, sizeof (*lr), NULL);
2125 
2126 	return (error);
2127 }
2128 
2129 static void
2130 ztest_prealloc(ztest_ds_t *zd, uint64_t object, uint64_t offset, uint64_t size)
2131 {
2132 	objset_t *os = zd->zd_os;
2133 	dmu_tx_t *tx;
2134 	uint64_t txg;
2135 	rl_t *rl;
2136 
2137 	txg_wait_synced(dmu_objset_pool(os), 0);
2138 
2139 	ztest_object_lock(zd, object, RL_READER);
2140 	rl = ztest_range_lock(zd, object, offset, size, RL_WRITER);
2141 
2142 	tx = dmu_tx_create(os);
2143 
2144 	dmu_tx_hold_write(tx, object, offset, size);
2145 
2146 	txg = ztest_tx_assign(tx, TXG_WAIT, FTAG);
2147 
2148 	if (txg != 0) {
2149 		dmu_prealloc(os, object, offset, size, tx);
2150 		dmu_tx_commit(tx);
2151 		txg_wait_synced(dmu_objset_pool(os), txg);
2152 	} else {
2153 		(void) dmu_free_long_range(os, object, offset, size);
2154 	}
2155 
2156 	ztest_range_unlock(rl);
2157 	ztest_object_unlock(zd, object);
2158 }
2159 
2160 static void
2161 ztest_io(ztest_ds_t *zd, uint64_t object, uint64_t offset)
2162 {
2163 	int err;
2164 	ztest_block_tag_t wbt;
2165 	dmu_object_info_t doi;
2166 	enum ztest_io_type io_type;
2167 	uint64_t blocksize;
2168 	void *data;
2169 
2170 	VERIFY(dmu_object_info(zd->zd_os, object, &doi) == 0);
2171 	blocksize = doi.doi_data_block_size;
2172 	data = umem_alloc(blocksize, UMEM_NOFAIL);
2173 
2174 	/*
2175 	 * Pick an i/o type at random, biased toward writing block tags.
2176 	 */
2177 	io_type = ztest_random(ZTEST_IO_TYPES);
2178 	if (ztest_random(2) == 0)
2179 		io_type = ZTEST_IO_WRITE_TAG;
2180 
2181 	(void) rw_rdlock(&zd->zd_zilog_lock);
2182 
2183 	switch (io_type) {
2184 
2185 	case ZTEST_IO_WRITE_TAG:
2186 		ztest_bt_generate(&wbt, zd->zd_os, object, offset, 0, 0, 0);
2187 		(void) ztest_write(zd, object, offset, sizeof (wbt), &wbt);
2188 		break;
2189 
2190 	case ZTEST_IO_WRITE_PATTERN:
2191 		(void) memset(data, 'a' + (object + offset) % 5, blocksize);
2192 		if (ztest_random(2) == 0) {
2193 			/*
2194 			 * Induce fletcher2 collisions to ensure that
2195 			 * zio_ddt_collision() detects and resolves them
2196 			 * when using fletcher2-verify for deduplication.
2197 			 */
2198 			((uint64_t *)data)[0] ^= 1ULL << 63;
2199 			((uint64_t *)data)[4] ^= 1ULL << 63;
2200 		}
2201 		(void) ztest_write(zd, object, offset, blocksize, data);
2202 		break;
2203 
2204 	case ZTEST_IO_WRITE_ZEROES:
2205 		bzero(data, blocksize);
2206 		(void) ztest_write(zd, object, offset, blocksize, data);
2207 		break;
2208 
2209 	case ZTEST_IO_TRUNCATE:
2210 		(void) ztest_truncate(zd, object, offset, blocksize);
2211 		break;
2212 
2213 	case ZTEST_IO_SETATTR:
2214 		(void) ztest_setattr(zd, object);
2215 		break;
2216 
2217 	case ZTEST_IO_REWRITE:
2218 		(void) rw_rdlock(&ztest_name_lock);
2219 		err = ztest_dsl_prop_set_uint64(zd->zd_name,
2220 		    ZFS_PROP_CHECKSUM, spa_dedup_checksum(ztest_spa),
2221 		    B_FALSE);
2222 		VERIFY(err == 0 || err == ENOSPC);
2223 		err = ztest_dsl_prop_set_uint64(zd->zd_name,
2224 		    ZFS_PROP_COMPRESSION,
2225 		    ztest_random_dsl_prop(ZFS_PROP_COMPRESSION),
2226 		    B_FALSE);
2227 		VERIFY(err == 0 || err == ENOSPC);
2228 		(void) rw_unlock(&ztest_name_lock);
2229 
2230 		VERIFY0(dmu_read(zd->zd_os, object, offset, blocksize, data,
2231 		    DMU_READ_NO_PREFETCH));
2232 
2233 		(void) ztest_write(zd, object, offset, blocksize, data);
2234 		break;
2235 	}
2236 
2237 	(void) rw_unlock(&zd->zd_zilog_lock);
2238 
2239 	umem_free(data, blocksize);
2240 }
2241 
2242 /*
2243  * Initialize an object description template.
2244  */
2245 static void
2246 ztest_od_init(ztest_od_t *od, uint64_t id, char *tag, uint64_t index,
2247     dmu_object_type_t type, uint64_t blocksize, uint64_t gen)
2248 {
2249 	od->od_dir = ZTEST_DIROBJ;
2250 	od->od_object = 0;
2251 
2252 	od->od_crtype = type;
2253 	od->od_crblocksize = blocksize ? blocksize : ztest_random_blocksize();
2254 	od->od_crgen = gen;
2255 
2256 	od->od_type = DMU_OT_NONE;
2257 	od->od_blocksize = 0;
2258 	od->od_gen = 0;
2259 
2260 	(void) snprintf(od->od_name, sizeof (od->od_name), "%s(%lld)[%llu]",
2261 	    tag, (int64_t)id, index);
2262 }
2263 
2264 /*
2265  * Lookup or create the objects for a test using the od template.
2266  * If the objects do not all exist, or if 'remove' is specified,
2267  * remove any existing objects and create new ones.  Otherwise,
2268  * use the existing objects.
2269  */
2270 static int
2271 ztest_object_init(ztest_ds_t *zd, ztest_od_t *od, size_t size, boolean_t remove)
2272 {
2273 	int count = size / sizeof (*od);
2274 	int rv = 0;
2275 
2276 	VERIFY(mutex_lock(&zd->zd_dirobj_lock) == 0);
2277 	if ((ztest_lookup(zd, od, count) != 0 || remove) &&
2278 	    (ztest_remove(zd, od, count) != 0 ||
2279 	    ztest_create(zd, od, count) != 0))
2280 		rv = -1;
2281 	zd->zd_od = od;
2282 	VERIFY(mutex_unlock(&zd->zd_dirobj_lock) == 0);
2283 
2284 	return (rv);
2285 }
2286 
2287 /* ARGSUSED */
2288 void
2289 ztest_zil_commit(ztest_ds_t *zd, uint64_t id)
2290 {
2291 	zilog_t *zilog = zd->zd_zilog;
2292 
2293 	(void) rw_rdlock(&zd->zd_zilog_lock);
2294 
2295 	zil_commit(zilog, ztest_random(ZTEST_OBJECTS));
2296 
2297 	/*
2298 	 * Remember the committed values in zd, which is in parent/child
2299 	 * shared memory.  If we die, the next iteration of ztest_run()
2300 	 * will verify that the log really does contain this record.
2301 	 */
2302 	mutex_enter(&zilog->zl_lock);
2303 	ASSERT(zd->zd_shared != NULL);
2304 	ASSERT3U(zd->zd_shared->zd_seq, <=, zilog->zl_commit_lr_seq);
2305 	zd->zd_shared->zd_seq = zilog->zl_commit_lr_seq;
2306 	mutex_exit(&zilog->zl_lock);
2307 
2308 	(void) rw_unlock(&zd->zd_zilog_lock);
2309 }
2310 
2311 /*
2312  * This function is designed to simulate the operations that occur during a
2313  * mount/unmount operation.  We hold the dataset across these operations in an
2314  * attempt to expose any implicit assumptions about ZIL management.
2315  */
2316 /* ARGSUSED */
2317 void
2318 ztest_zil_remount(ztest_ds_t *zd, uint64_t id)
2319 {
2320 	objset_t *os = zd->zd_os;
2321 
2322 	/*
2323 	 * We grab the zd_dirobj_lock to ensure that no other thread is
2324 	 * updating the zil (i.e. adding in-memory log records) and the
2325 	 * zd_zilog_lock to block any I/O.
2326 	 */
2327 	VERIFY0(mutex_lock(&zd->zd_dirobj_lock));
2328 	(void) rw_wrlock(&zd->zd_zilog_lock);
2329 
2330 	/* zfsvfs_teardown() */
2331 	zil_close(zd->zd_zilog);
2332 
2333 	/* zfsvfs_setup() */
2334 	VERIFY(zil_open(os, ztest_get_data) == zd->zd_zilog);
2335 	zil_replay(os, zd, ztest_replay_vector);
2336 
2337 	(void) rw_unlock(&zd->zd_zilog_lock);
2338 	VERIFY(mutex_unlock(&zd->zd_dirobj_lock) == 0);
2339 }
2340 
2341 /*
2342  * Verify that we can't destroy an active pool, create an existing pool,
2343  * or create a pool with a bad vdev spec.
2344  */
2345 /* ARGSUSED */
2346 void
2347 ztest_spa_create_destroy(ztest_ds_t *zd, uint64_t id)
2348 {
2349 	ztest_shared_opts_t *zo = &ztest_opts;
2350 	spa_t *spa;
2351 	nvlist_t *nvroot;
2352 
2353 	/*
2354 	 * Attempt to create using a bad file.
2355 	 */
2356 	nvroot = make_vdev_root("/dev/bogus", NULL, NULL, 0, 0, 0, 0, 0, 1);
2357 	VERIFY3U(ENOENT, ==,
2358 	    spa_create("ztest_bad_file", nvroot, NULL, NULL));
2359 	nvlist_free(nvroot);
2360 
2361 	/*
2362 	 * Attempt to create using a bad mirror.
2363 	 */
2364 	nvroot = make_vdev_root("/dev/bogus", NULL, NULL, 0, 0, 0, 0, 2, 1);
2365 	VERIFY3U(ENOENT, ==,
2366 	    spa_create("ztest_bad_mirror", nvroot, NULL, NULL));
2367 	nvlist_free(nvroot);
2368 
2369 	/*
2370 	 * Attempt to create an existing pool.  It shouldn't matter
2371 	 * what's in the nvroot; we should fail with EEXIST.
2372 	 */
2373 	(void) rw_rdlock(&ztest_name_lock);
2374 	nvroot = make_vdev_root("/dev/bogus", NULL, NULL, 0, 0, 0, 0, 0, 1);
2375 	VERIFY3U(EEXIST, ==, spa_create(zo->zo_pool, nvroot, NULL, NULL));
2376 	nvlist_free(nvroot);
2377 	VERIFY3U(0, ==, spa_open(zo->zo_pool, &spa, FTAG));
2378 	VERIFY3U(EBUSY, ==, spa_destroy(zo->zo_pool));
2379 	spa_close(spa, FTAG);
2380 
2381 	(void) rw_unlock(&ztest_name_lock);
2382 }
2383 
2384 /* ARGSUSED */
2385 void
2386 ztest_spa_upgrade(ztest_ds_t *zd, uint64_t id)
2387 {
2388 	spa_t *spa;
2389 	uint64_t initial_version = SPA_VERSION_INITIAL;
2390 	uint64_t version, newversion;
2391 	nvlist_t *nvroot, *props;
2392 	char *name;
2393 
2394 	VERIFY0(mutex_lock(&ztest_vdev_lock));
2395 	name = kmem_asprintf("%s_upgrade", ztest_opts.zo_pool);
2396 
2397 	/*
2398 	 * Clean up from previous runs.
2399 	 */
2400 	(void) spa_destroy(name);
2401 
2402 	nvroot = make_vdev_root(NULL, NULL, name, ztest_opts.zo_vdev_size, 0,
2403 	    0, ztest_opts.zo_raidz, ztest_opts.zo_mirrors, 1);
2404 
2405 	/*
2406 	 * If we're configuring a RAIDZ device then make sure that the
2407 	 * the initial version is capable of supporting that feature.
2408 	 */
2409 	switch (ztest_opts.zo_raidz_parity) {
2410 	case 0:
2411 	case 1:
2412 		initial_version = SPA_VERSION_INITIAL;
2413 		break;
2414 	case 2:
2415 		initial_version = SPA_VERSION_RAIDZ2;
2416 		break;
2417 	case 3:
2418 		initial_version = SPA_VERSION_RAIDZ3;
2419 		break;
2420 	}
2421 
2422 	/*
2423 	 * Create a pool with a spa version that can be upgraded. Pick
2424 	 * a value between initial_version and SPA_VERSION_BEFORE_FEATURES.
2425 	 */
2426 	do {
2427 		version = ztest_random_spa_version(initial_version);
2428 	} while (version > SPA_VERSION_BEFORE_FEATURES);
2429 
2430 	props = fnvlist_alloc();
2431 	fnvlist_add_uint64(props,
2432 	    zpool_prop_to_name(ZPOOL_PROP_VERSION), version);
2433 	VERIFY0(spa_create(name, nvroot, props, NULL));
2434 	fnvlist_free(nvroot);
2435 	fnvlist_free(props);
2436 
2437 	VERIFY0(spa_open(name, &spa, FTAG));
2438 	VERIFY3U(spa_version(spa), ==, version);
2439 	newversion = ztest_random_spa_version(version + 1);
2440 
2441 	if (ztest_opts.zo_verbose >= 4) {
2442 		(void) printf("upgrading spa version from %llu to %llu\n",
2443 		    (u_longlong_t)version, (u_longlong_t)newversion);
2444 	}
2445 
2446 	spa_upgrade(spa, newversion);
2447 	VERIFY3U(spa_version(spa), >, version);
2448 	VERIFY3U(spa_version(spa), ==, fnvlist_lookup_uint64(spa->spa_config,
2449 	    zpool_prop_to_name(ZPOOL_PROP_VERSION)));
2450 	spa_close(spa, FTAG);
2451 
2452 	strfree(name);
2453 	VERIFY0(mutex_unlock(&ztest_vdev_lock));
2454 }
2455 
2456 static vdev_t *
2457 vdev_lookup_by_path(vdev_t *vd, const char *path)
2458 {
2459 	vdev_t *mvd;
2460 
2461 	if (vd->vdev_path != NULL && strcmp(path, vd->vdev_path) == 0)
2462 		return (vd);
2463 
2464 	for (int c = 0; c < vd->vdev_children; c++)
2465 		if ((mvd = vdev_lookup_by_path(vd->vdev_child[c], path)) !=
2466 		    NULL)
2467 			return (mvd);
2468 
2469 	return (NULL);
2470 }
2471 
2472 /*
2473  * Find the first available hole which can be used as a top-level.
2474  */
2475 int
2476 find_vdev_hole(spa_t *spa)
2477 {
2478 	vdev_t *rvd = spa->spa_root_vdev;
2479 	int c;
2480 
2481 	ASSERT(spa_config_held(spa, SCL_VDEV, RW_READER) == SCL_VDEV);
2482 
2483 	for (c = 0; c < rvd->vdev_children; c++) {
2484 		vdev_t *cvd = rvd->vdev_child[c];
2485 
2486 		if (cvd->vdev_ishole)
2487 			break;
2488 	}
2489 	return (c);
2490 }
2491 
2492 /*
2493  * Verify that vdev_add() works as expected.
2494  */
2495 /* ARGSUSED */
2496 void
2497 ztest_vdev_add_remove(ztest_ds_t *zd, uint64_t id)
2498 {
2499 	ztest_shared_t *zs = ztest_shared;
2500 	spa_t *spa = ztest_spa;
2501 	uint64_t leaves;
2502 	uint64_t guid;
2503 	nvlist_t *nvroot;
2504 	int error;
2505 
2506 	VERIFY(mutex_lock(&ztest_vdev_lock) == 0);
2507 	leaves = MAX(zs->zs_mirrors + zs->zs_splits, 1) * ztest_opts.zo_raidz;
2508 
2509 	spa_config_enter(spa, SCL_VDEV, FTAG, RW_READER);
2510 
2511 	ztest_shared->zs_vdev_next_leaf = find_vdev_hole(spa) * leaves;
2512 
2513 	/*
2514 	 * If we have slogs then remove them 1/4 of the time.
2515 	 */
2516 	if (spa_has_slogs(spa) && ztest_random(4) == 0) {
2517 		/*
2518 		 * Grab the guid from the head of the log class rotor.
2519 		 */
2520 		guid = spa_log_class(spa)->mc_rotor->mg_vd->vdev_guid;
2521 
2522 		spa_config_exit(spa, SCL_VDEV, FTAG);
2523 
2524 		/*
2525 		 * We have to grab the zs_name_lock as writer to
2526 		 * prevent a race between removing a slog (dmu_objset_find)
2527 		 * and destroying a dataset. Removing the slog will
2528 		 * grab a reference on the dataset which may cause
2529 		 * dmu_objset_destroy() to fail with EBUSY thus
2530 		 * leaving the dataset in an inconsistent state.
2531 		 */
2532 		VERIFY(rw_wrlock(&ztest_name_lock) == 0);
2533 		error = spa_vdev_remove(spa, guid, B_FALSE);
2534 		VERIFY(rw_unlock(&ztest_name_lock) == 0);
2535 
2536 		if (error && error != EEXIST)
2537 			fatal(0, "spa_vdev_remove() = %d", error);
2538 	} else {
2539 		spa_config_exit(spa, SCL_VDEV, FTAG);
2540 
2541 		/*
2542 		 * Make 1/4 of the devices be log devices.
2543 		 */
2544 		nvroot = make_vdev_root(NULL, NULL, NULL,
2545 		    ztest_opts.zo_vdev_size, 0,
2546 		    ztest_random(4) == 0, ztest_opts.zo_raidz,
2547 		    zs->zs_mirrors, 1);
2548 
2549 		error = spa_vdev_add(spa, nvroot);
2550 		nvlist_free(nvroot);
2551 
2552 		if (error == ENOSPC)
2553 			ztest_record_enospc("spa_vdev_add");
2554 		else if (error != 0)
2555 			fatal(0, "spa_vdev_add() = %d", error);
2556 	}
2557 
2558 	VERIFY(mutex_unlock(&ztest_vdev_lock) == 0);
2559 }
2560 
2561 /*
2562  * Verify that adding/removing aux devices (l2arc, hot spare) works as expected.
2563  */
2564 /* ARGSUSED */
2565 void
2566 ztest_vdev_aux_add_remove(ztest_ds_t *zd, uint64_t id)
2567 {
2568 	ztest_shared_t *zs = ztest_shared;
2569 	spa_t *spa = ztest_spa;
2570 	vdev_t *rvd = spa->spa_root_vdev;
2571 	spa_aux_vdev_t *sav;
2572 	char *aux;
2573 	uint64_t guid = 0;
2574 	int error;
2575 
2576 	if (ztest_random(2) == 0) {
2577 		sav = &spa->spa_spares;
2578 		aux = ZPOOL_CONFIG_SPARES;
2579 	} else {
2580 		sav = &spa->spa_l2cache;
2581 		aux = ZPOOL_CONFIG_L2CACHE;
2582 	}
2583 
2584 	VERIFY(mutex_lock(&ztest_vdev_lock) == 0);
2585 
2586 	spa_config_enter(spa, SCL_VDEV, FTAG, RW_READER);
2587 
2588 	if (sav->sav_count != 0 && ztest_random(4) == 0) {
2589 		/*
2590 		 * Pick a random device to remove.
2591 		 */
2592 		guid = sav->sav_vdevs[ztest_random(sav->sav_count)]->vdev_guid;
2593 	} else {
2594 		/*
2595 		 * Find an unused device we can add.
2596 		 */
2597 		zs->zs_vdev_aux = 0;
2598 		for (;;) {
2599 			char path[MAXPATHLEN];
2600 			int c;
2601 			(void) snprintf(path, sizeof (path), ztest_aux_template,
2602 			    ztest_opts.zo_dir, ztest_opts.zo_pool, aux,
2603 			    zs->zs_vdev_aux);
2604 			for (c = 0; c < sav->sav_count; c++)
2605 				if (strcmp(sav->sav_vdevs[c]->vdev_path,
2606 				    path) == 0)
2607 					break;
2608 			if (c == sav->sav_count &&
2609 			    vdev_lookup_by_path(rvd, path) == NULL)
2610 				break;
2611 			zs->zs_vdev_aux++;
2612 		}
2613 	}
2614 
2615 	spa_config_exit(spa, SCL_VDEV, FTAG);
2616 
2617 	if (guid == 0) {
2618 		/*
2619 		 * Add a new device.
2620 		 */
2621 		nvlist_t *nvroot = make_vdev_root(NULL, aux, NULL,
2622 		    (ztest_opts.zo_vdev_size * 5) / 4, 0, 0, 0, 0, 1);
2623 		error = spa_vdev_add(spa, nvroot);
2624 		if (error != 0)
2625 			fatal(0, "spa_vdev_add(%p) = %d", nvroot, error);
2626 		nvlist_free(nvroot);
2627 	} else {
2628 		/*
2629 		 * Remove an existing device.  Sometimes, dirty its
2630 		 * vdev state first to make sure we handle removal
2631 		 * of devices that have pending state changes.
2632 		 */
2633 		if (ztest_random(2) == 0)
2634 			(void) vdev_online(spa, guid, 0, NULL);
2635 
2636 		error = spa_vdev_remove(spa, guid, B_FALSE);
2637 		if (error != 0 && error != EBUSY)
2638 			fatal(0, "spa_vdev_remove(%llu) = %d", guid, error);
2639 	}
2640 
2641 	VERIFY(mutex_unlock(&ztest_vdev_lock) == 0);
2642 }
2643 
2644 /*
2645  * split a pool if it has mirror tlvdevs
2646  */
2647 /* ARGSUSED */
2648 void
2649 ztest_split_pool(ztest_ds_t *zd, uint64_t id)
2650 {
2651 	ztest_shared_t *zs = ztest_shared;
2652 	spa_t *spa = ztest_spa;
2653 	vdev_t *rvd = spa->spa_root_vdev;
2654 	nvlist_t *tree, **child, *config, *split, **schild;
2655 	uint_t c, children, schildren = 0, lastlogid = 0;
2656 	int error = 0;
2657 
2658 	VERIFY(mutex_lock(&ztest_vdev_lock) == 0);
2659 
2660 	/* ensure we have a useable config; mirrors of raidz aren't supported */
2661 	if (zs->zs_mirrors < 3 || ztest_opts.zo_raidz > 1) {
2662 		VERIFY(mutex_unlock(&ztest_vdev_lock) == 0);
2663 		return;
2664 	}
2665 
2666 	/* clean up the old pool, if any */
2667 	(void) spa_destroy("splitp");
2668 
2669 	spa_config_enter(spa, SCL_VDEV, FTAG, RW_READER);
2670 
2671 	/* generate a config from the existing config */
2672 	mutex_enter(&spa->spa_props_lock);
2673 	VERIFY(nvlist_lookup_nvlist(spa->spa_config, ZPOOL_CONFIG_VDEV_TREE,
2674 	    &tree) == 0);
2675 	mutex_exit(&spa->spa_props_lock);
2676 
2677 	VERIFY(nvlist_lookup_nvlist_array(tree, ZPOOL_CONFIG_CHILDREN, &child,
2678 	    &children) == 0);
2679 
2680 	schild = malloc(rvd->vdev_children * sizeof (nvlist_t *));
2681 	for (c = 0; c < children; c++) {
2682 		vdev_t *tvd = rvd->vdev_child[c];
2683 		nvlist_t **mchild;
2684 		uint_t mchildren;
2685 
2686 		if (tvd->vdev_islog || tvd->vdev_ops == &vdev_hole_ops) {
2687 			VERIFY(nvlist_alloc(&schild[schildren], NV_UNIQUE_NAME,
2688 			    0) == 0);
2689 			VERIFY(nvlist_add_string(schild[schildren],
2690 			    ZPOOL_CONFIG_TYPE, VDEV_TYPE_HOLE) == 0);
2691 			VERIFY(nvlist_add_uint64(schild[schildren],
2692 			    ZPOOL_CONFIG_IS_HOLE, 1) == 0);
2693 			if (lastlogid == 0)
2694 				lastlogid = schildren;
2695 			++schildren;
2696 			continue;
2697 		}
2698 		lastlogid = 0;
2699 		VERIFY(nvlist_lookup_nvlist_array(child[c],
2700 		    ZPOOL_CONFIG_CHILDREN, &mchild, &mchildren) == 0);
2701 		VERIFY(nvlist_dup(mchild[0], &schild[schildren++], 0) == 0);
2702 	}
2703 
2704 	/* OK, create a config that can be used to split */
2705 	VERIFY(nvlist_alloc(&split, NV_UNIQUE_NAME, 0) == 0);
2706 	VERIFY(nvlist_add_string(split, ZPOOL_CONFIG_TYPE,
2707 	    VDEV_TYPE_ROOT) == 0);
2708 	VERIFY(nvlist_add_nvlist_array(split, ZPOOL_CONFIG_CHILDREN, schild,
2709 	    lastlogid != 0 ? lastlogid : schildren) == 0);
2710 
2711 	VERIFY(nvlist_alloc(&config, NV_UNIQUE_NAME, 0) == 0);
2712 	VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, split) == 0);
2713 
2714 	for (c = 0; c < schildren; c++)
2715 		nvlist_free(schild[c]);
2716 	free(schild);
2717 	nvlist_free(split);
2718 
2719 	spa_config_exit(spa, SCL_VDEV, FTAG);
2720 
2721 	(void) rw_wrlock(&ztest_name_lock);
2722 	error = spa_vdev_split_mirror(spa, "splitp", config, NULL, B_FALSE);
2723 	(void) rw_unlock(&ztest_name_lock);
2724 
2725 	nvlist_free(config);
2726 
2727 	if (error == 0) {
2728 		(void) printf("successful split - results:\n");
2729 		mutex_enter(&spa_namespace_lock);
2730 		show_pool_stats(spa);
2731 		show_pool_stats(spa_lookup("splitp"));
2732 		mutex_exit(&spa_namespace_lock);
2733 		++zs->zs_splits;
2734 		--zs->zs_mirrors;
2735 	}
2736 	VERIFY(mutex_unlock(&ztest_vdev_lock) == 0);
2737 
2738 }
2739 
2740 /*
2741  * Verify that we can attach and detach devices.
2742  */
2743 /* ARGSUSED */
2744 void
2745 ztest_vdev_attach_detach(ztest_ds_t *zd, uint64_t id)
2746 {
2747 	ztest_shared_t *zs = ztest_shared;
2748 	spa_t *spa = ztest_spa;
2749 	spa_aux_vdev_t *sav = &spa->spa_spares;
2750 	vdev_t *rvd = spa->spa_root_vdev;
2751 	vdev_t *oldvd, *newvd, *pvd;
2752 	nvlist_t *root;
2753 	uint64_t leaves;
2754 	uint64_t leaf, top;
2755 	uint64_t ashift = ztest_get_ashift();
2756 	uint64_t oldguid, pguid;
2757 	uint64_t oldsize, newsize;
2758 	char oldpath[MAXPATHLEN], newpath[MAXPATHLEN];
2759 	int replacing;
2760 	int oldvd_has_siblings = B_FALSE;
2761 	int newvd_is_spare = B_FALSE;
2762 	int oldvd_is_log;
2763 	int error, expected_error;
2764 
2765 	VERIFY(mutex_lock(&ztest_vdev_lock) == 0);
2766 	leaves = MAX(zs->zs_mirrors, 1) * ztest_opts.zo_raidz;
2767 
2768 	spa_config_enter(spa, SCL_VDEV, FTAG, RW_READER);
2769 
2770 	/*
2771 	 * Decide whether to do an attach or a replace.
2772 	 */
2773 	replacing = ztest_random(2);
2774 
2775 	/*
2776 	 * Pick a random top-level vdev.
2777 	 */
2778 	top = ztest_random_vdev_top(spa, B_TRUE);
2779 
2780 	/*
2781 	 * Pick a random leaf within it.
2782 	 */
2783 	leaf = ztest_random(leaves);
2784 
2785 	/*
2786 	 * Locate this vdev.
2787 	 */
2788 	oldvd = rvd->vdev_child[top];
2789 	if (zs->zs_mirrors >= 1) {
2790 		ASSERT(oldvd->vdev_ops == &vdev_mirror_ops);
2791 		ASSERT(oldvd->vdev_children >= zs->zs_mirrors);
2792 		oldvd = oldvd->vdev_child[leaf / ztest_opts.zo_raidz];
2793 	}
2794 	if (ztest_opts.zo_raidz > 1) {
2795 		ASSERT(oldvd->vdev_ops == &vdev_raidz_ops);
2796 		ASSERT(oldvd->vdev_children == ztest_opts.zo_raidz);
2797 		oldvd = oldvd->vdev_child[leaf % ztest_opts.zo_raidz];
2798 	}
2799 
2800 	/*
2801 	 * If we're already doing an attach or replace, oldvd may be a
2802 	 * mirror vdev -- in which case, pick a random child.
2803 	 */
2804 	while (oldvd->vdev_children != 0) {
2805 		oldvd_has_siblings = B_TRUE;
2806 		ASSERT(oldvd->vdev_children >= 2);
2807 		oldvd = oldvd->vdev_child[ztest_random(oldvd->vdev_children)];
2808 	}
2809 
2810 	oldguid = oldvd->vdev_guid;
2811 	oldsize = vdev_get_min_asize(oldvd);
2812 	oldvd_is_log = oldvd->vdev_top->vdev_islog;
2813 	(void) strcpy(oldpath, oldvd->vdev_path);
2814 	pvd = oldvd->vdev_parent;
2815 	pguid = pvd->vdev_guid;
2816 
2817 	/*
2818 	 * If oldvd has siblings, then half of the time, detach it.
2819 	 */
2820 	if (oldvd_has_siblings && ztest_random(2) == 0) {
2821 		spa_config_exit(spa, SCL_VDEV, FTAG);
2822 		error = spa_vdev_detach(spa, oldguid, pguid, B_FALSE);
2823 		if (error != 0 && error != ENODEV && error != EBUSY &&
2824 		    error != ENOTSUP)
2825 			fatal(0, "detach (%s) returned %d", oldpath, error);
2826 		VERIFY(mutex_unlock(&ztest_vdev_lock) == 0);
2827 		return;
2828 	}
2829 
2830 	/*
2831 	 * For the new vdev, choose with equal probability between the two
2832 	 * standard paths (ending in either 'a' or 'b') or a random hot spare.
2833 	 */
2834 	if (sav->sav_count != 0 && ztest_random(3) == 0) {
2835 		newvd = sav->sav_vdevs[ztest_random(sav->sav_count)];
2836 		newvd_is_spare = B_TRUE;
2837 		(void) strcpy(newpath, newvd->vdev_path);
2838 	} else {
2839 		(void) snprintf(newpath, sizeof (newpath), ztest_dev_template,
2840 		    ztest_opts.zo_dir, ztest_opts.zo_pool,
2841 		    top * leaves + leaf);
2842 		if (ztest_random(2) == 0)
2843 			newpath[strlen(newpath) - 1] = 'b';
2844 		newvd = vdev_lookup_by_path(rvd, newpath);
2845 	}
2846 
2847 	if (newvd) {
2848 		newsize = vdev_get_min_asize(newvd);
2849 	} else {
2850 		/*
2851 		 * Make newsize a little bigger or smaller than oldsize.
2852 		 * If it's smaller, the attach should fail.
2853 		 * If it's larger, and we're doing a replace,
2854 		 * we should get dynamic LUN growth when we're done.
2855 		 */
2856 		newsize = 10 * oldsize / (9 + ztest_random(3));
2857 	}
2858 
2859 	/*
2860 	 * If pvd is not a mirror or root, the attach should fail with ENOTSUP,
2861 	 * unless it's a replace; in that case any non-replacing parent is OK.
2862 	 *
2863 	 * If newvd is already part of the pool, it should fail with EBUSY.
2864 	 *
2865 	 * If newvd is too small, it should fail with EOVERFLOW.
2866 	 */
2867 	if (pvd->vdev_ops != &vdev_mirror_ops &&
2868 	    pvd->vdev_ops != &vdev_root_ops && (!replacing ||
2869 	    pvd->vdev_ops == &vdev_replacing_ops ||
2870 	    pvd->vdev_ops == &vdev_spare_ops))
2871 		expected_error = ENOTSUP;
2872 	else if (newvd_is_spare && (!replacing || oldvd_is_log))
2873 		expected_error = ENOTSUP;
2874 	else if (newvd == oldvd)
2875 		expected_error = replacing ? 0 : EBUSY;
2876 	else if (vdev_lookup_by_path(rvd, newpath) != NULL)
2877 		expected_error = EBUSY;
2878 	else if (newsize < oldsize)
2879 		expected_error = EOVERFLOW;
2880 	else if (ashift > oldvd->vdev_top->vdev_ashift)
2881 		expected_error = EDOM;
2882 	else
2883 		expected_error = 0;
2884 
2885 	spa_config_exit(spa, SCL_VDEV, FTAG);
2886 
2887 	/*
2888 	 * Build the nvlist describing newpath.
2889 	 */
2890 	root = make_vdev_root(newpath, NULL, NULL, newvd == NULL ? newsize : 0,
2891 	    ashift, 0, 0, 0, 1);
2892 
2893 	error = spa_vdev_attach(spa, oldguid, root, replacing);
2894 
2895 	nvlist_free(root);
2896 
2897 	/*
2898 	 * If our parent was the replacing vdev, but the replace completed,
2899 	 * then instead of failing with ENOTSUP we may either succeed,
2900 	 * fail with ENODEV, or fail with EOVERFLOW.
2901 	 */
2902 	if (expected_error == ENOTSUP &&
2903 	    (error == 0 || error == ENODEV || error == EOVERFLOW))
2904 		expected_error = error;
2905 
2906 	/*
2907 	 * If someone grew the LUN, the replacement may be too small.
2908 	 */
2909 	if (error == EOVERFLOW || error == EBUSY)
2910 		expected_error = error;
2911 
2912 	/* XXX workaround 6690467 */
2913 	if (error != expected_error && expected_error != EBUSY) {
2914 		fatal(0, "attach (%s %llu, %s %llu, %d) "
2915 		    "returned %d, expected %d",
2916 		    oldpath, oldsize, newpath,
2917 		    newsize, replacing, error, expected_error);
2918 	}
2919 
2920 	VERIFY(mutex_unlock(&ztest_vdev_lock) == 0);
2921 }
2922 
2923 /*
2924  * Callback function which expands the physical size of the vdev.
2925  */
2926 vdev_t *
2927 grow_vdev(vdev_t *vd, void *arg)
2928 {
2929 	spa_t *spa = vd->vdev_spa;
2930 	size_t *newsize = arg;
2931 	size_t fsize;
2932 	int fd;
2933 
2934 	ASSERT(spa_config_held(spa, SCL_STATE, RW_READER) == SCL_STATE);
2935 	ASSERT(vd->vdev_ops->vdev_op_leaf);
2936 
2937 	if ((fd = open(vd->vdev_path, O_RDWR)) == -1)
2938 		return (vd);
2939 
2940 	fsize = lseek(fd, 0, SEEK_END);
2941 	(void) ftruncate(fd, *newsize);
2942 
2943 	if (ztest_opts.zo_verbose >= 6) {
2944 		(void) printf("%s grew from %lu to %lu bytes\n",
2945 		    vd->vdev_path, (ulong_t)fsize, (ulong_t)*newsize);
2946 	}
2947 	(void) close(fd);
2948 	return (NULL);
2949 }
2950 
2951 /*
2952  * Callback function which expands a given vdev by calling vdev_online().
2953  */
2954 /* ARGSUSED */
2955 vdev_t *
2956 online_vdev(vdev_t *vd, void *arg)
2957 {
2958 	spa_t *spa = vd->vdev_spa;
2959 	vdev_t *tvd = vd->vdev_top;
2960 	uint64_t guid = vd->vdev_guid;
2961 	uint64_t generation = spa->spa_config_generation + 1;
2962 	vdev_state_t newstate = VDEV_STATE_UNKNOWN;
2963 	int error;
2964 
2965 	ASSERT(spa_config_held(spa, SCL_STATE, RW_READER) == SCL_STATE);
2966 	ASSERT(vd->vdev_ops->vdev_op_leaf);
2967 
2968 	/* Calling vdev_online will initialize the new metaslabs */
2969 	spa_config_exit(spa, SCL_STATE, spa);
2970 	error = vdev_online(spa, guid, ZFS_ONLINE_EXPAND, &newstate);
2971 	spa_config_enter(spa, SCL_STATE, spa, RW_READER);
2972 
2973 	/*
2974 	 * If vdev_online returned an error or the underlying vdev_open
2975 	 * failed then we abort the expand. The only way to know that
2976 	 * vdev_open fails is by checking the returned newstate.
2977 	 */
2978 	if (error || newstate != VDEV_STATE_HEALTHY) {
2979 		if (ztest_opts.zo_verbose >= 5) {
2980 			(void) printf("Unable to expand vdev, state %llu, "
2981 			    "error %d\n", (u_longlong_t)newstate, error);
2982 		}
2983 		return (vd);
2984 	}
2985 	ASSERT3U(newstate, ==, VDEV_STATE_HEALTHY);
2986 
2987 	/*
2988 	 * Since we dropped the lock we need to ensure that we're
2989 	 * still talking to the original vdev. It's possible this
2990 	 * vdev may have been detached/replaced while we were
2991 	 * trying to online it.
2992 	 */
2993 	if (generation != spa->spa_config_generation) {
2994 		if (ztest_opts.zo_verbose >= 5) {
2995 			(void) printf("vdev configuration has changed, "
2996 			    "guid %llu, state %llu, expected gen %llu, "
2997 			    "got gen %llu\n",
2998 			    (u_longlong_t)guid,
2999 			    (u_longlong_t)tvd->vdev_state,
3000 			    (u_longlong_t)generation,
3001 			    (u_longlong_t)spa->spa_config_generation);
3002 		}
3003 		return (vd);
3004 	}
3005 	return (NULL);
3006 }
3007 
3008 /*
3009  * Traverse the vdev tree calling the supplied function.
3010  * We continue to walk the tree until we either have walked all
3011  * children or we receive a non-NULL return from the callback.
3012  * If a NULL callback is passed, then we just return back the first
3013  * leaf vdev we encounter.
3014  */
3015 vdev_t *
3016 vdev_walk_tree(vdev_t *vd, vdev_t *(*func)(vdev_t *, void *), void *arg)
3017 {
3018 	if (vd->vdev_ops->vdev_op_leaf) {
3019 		if (func == NULL)
3020 			return (vd);
3021 		else
3022 			return (func(vd, arg));
3023 	}
3024 
3025 	for (uint_t c = 0; c < vd->vdev_children; c++) {
3026 		vdev_t *cvd = vd->vdev_child[c];
3027 		if ((cvd = vdev_walk_tree(cvd, func, arg)) != NULL)
3028 			return (cvd);
3029 	}
3030 	return (NULL);
3031 }
3032 
3033 /*
3034  * Verify that dynamic LUN growth works as expected.
3035  */
3036 /* ARGSUSED */
3037 void
3038 ztest_vdev_LUN_growth(ztest_ds_t *zd, uint64_t id)
3039 {
3040 	spa_t *spa = ztest_spa;
3041 	vdev_t *vd, *tvd;
3042 	metaslab_class_t *mc;
3043 	metaslab_group_t *mg;
3044 	size_t psize, newsize;
3045 	uint64_t top;
3046 	uint64_t old_class_space, new_class_space, old_ms_count, new_ms_count;
3047 
3048 	VERIFY(mutex_lock(&ztest_vdev_lock) == 0);
3049 	spa_config_enter(spa, SCL_STATE, spa, RW_READER);
3050 
3051 	top = ztest_random_vdev_top(spa, B_TRUE);
3052 
3053 	tvd = spa->spa_root_vdev->vdev_child[top];
3054 	mg = tvd->vdev_mg;
3055 	mc = mg->mg_class;
3056 	old_ms_count = tvd->vdev_ms_count;
3057 	old_class_space = metaslab_class_get_space(mc);
3058 
3059 	/*
3060 	 * Determine the size of the first leaf vdev associated with
3061 	 * our top-level device.
3062 	 */
3063 	vd = vdev_walk_tree(tvd, NULL, NULL);
3064 	ASSERT3P(vd, !=, NULL);
3065 	ASSERT(vd->vdev_ops->vdev_op_leaf);
3066 
3067 	psize = vd->vdev_psize;
3068 
3069 	/*
3070 	 * We only try to expand the vdev if it's healthy, less than 4x its
3071 	 * original size, and it has a valid psize.
3072 	 */
3073 	if (tvd->vdev_state != VDEV_STATE_HEALTHY ||
3074 	    psize == 0 || psize >= 4 * ztest_opts.zo_vdev_size) {
3075 		spa_config_exit(spa, SCL_STATE, spa);
3076 		VERIFY(mutex_unlock(&ztest_vdev_lock) == 0);
3077 		return;
3078 	}
3079 	ASSERT(psize > 0);
3080 	newsize = psize + psize / 8;
3081 	ASSERT3U(newsize, >, psize);
3082 
3083 	if (ztest_opts.zo_verbose >= 6) {
3084 		(void) printf("Expanding LUN %s from %lu to %lu\n",
3085 		    vd->vdev_path, (ulong_t)psize, (ulong_t)newsize);
3086 	}
3087 
3088 	/*
3089 	 * Growing the vdev is a two step process:
3090 	 *	1). expand the physical size (i.e. relabel)
3091 	 *	2). online the vdev to create the new metaslabs
3092 	 */
3093 	if (vdev_walk_tree(tvd, grow_vdev, &newsize) != NULL ||
3094 	    vdev_walk_tree(tvd, online_vdev, NULL) != NULL ||
3095 	    tvd->vdev_state != VDEV_STATE_HEALTHY) {
3096 		if (ztest_opts.zo_verbose >= 5) {
3097 			(void) printf("Could not expand LUN because "
3098 			    "the vdev configuration changed.\n");
3099 		}
3100 		spa_config_exit(spa, SCL_STATE, spa);
3101 		VERIFY(mutex_unlock(&ztest_vdev_lock) == 0);
3102 		return;
3103 	}
3104 
3105 	spa_config_exit(spa, SCL_STATE, spa);
3106 
3107 	/*
3108 	 * Expanding the LUN will update the config asynchronously,
3109 	 * thus we must wait for the async thread to complete any
3110 	 * pending tasks before proceeding.
3111 	 */
3112 	for (;;) {
3113 		boolean_t done;
3114 		mutex_enter(&spa->spa_async_lock);
3115 		done = (spa->spa_async_thread == NULL && !spa->spa_async_tasks);
3116 		mutex_exit(&spa->spa_async_lock);
3117 		if (done)
3118 			break;
3119 		txg_wait_synced(spa_get_dsl(spa), 0);
3120 		(void) poll(NULL, 0, 100);
3121 	}
3122 
3123 	spa_config_enter(spa, SCL_STATE, spa, RW_READER);
3124 
3125 	tvd = spa->spa_root_vdev->vdev_child[top];
3126 	new_ms_count = tvd->vdev_ms_count;
3127 	new_class_space = metaslab_class_get_space(mc);
3128 
3129 	if (tvd->vdev_mg != mg || mg->mg_class != mc) {
3130 		if (ztest_opts.zo_verbose >= 5) {
3131 			(void) printf("Could not verify LUN expansion due to "
3132 			    "intervening vdev offline or remove.\n");
3133 		}
3134 		spa_config_exit(spa, SCL_STATE, spa);
3135 		VERIFY(mutex_unlock(&ztest_vdev_lock) == 0);
3136 		return;
3137 	}
3138 
3139 	/*
3140 	 * Make sure we were able to grow the vdev.
3141 	 */
3142 	if (new_ms_count <= old_ms_count)
3143 		fatal(0, "LUN expansion failed: ms_count %llu <= %llu\n",
3144 		    old_ms_count, new_ms_count);
3145 
3146 	/*
3147 	 * Make sure we were able to grow the pool.
3148 	 */
3149 	if (new_class_space <= old_class_space)
3150 		fatal(0, "LUN expansion failed: class_space %llu <= %llu\n",
3151 		    old_class_space, new_class_space);
3152 
3153 	if (ztest_opts.zo_verbose >= 5) {
3154 		char oldnumbuf[NN_NUMBUF_SZ], newnumbuf[NN_NUMBUF_SZ];
3155 
3156 		nicenum(old_class_space, oldnumbuf, sizeof (oldnumbuf));
3157 		nicenum(new_class_space, newnumbuf, sizeof (newnumbuf));
3158 		(void) printf("%s grew from %s to %s\n",
3159 		    spa->spa_name, oldnumbuf, newnumbuf);
3160 	}
3161 
3162 	spa_config_exit(spa, SCL_STATE, spa);
3163 	VERIFY(mutex_unlock(&ztest_vdev_lock) == 0);
3164 }
3165 
3166 /*
3167  * Verify that dmu_objset_{create,destroy,open,close} work as expected.
3168  */
3169 /* ARGSUSED */
3170 static void
3171 ztest_objset_create_cb(objset_t *os, void *arg, cred_t *cr, dmu_tx_t *tx)
3172 {
3173 	/*
3174 	 * Create the objects common to all ztest datasets.
3175 	 */
3176 	VERIFY(zap_create_claim(os, ZTEST_DIROBJ,
3177 	    DMU_OT_ZAP_OTHER, DMU_OT_NONE, 0, tx) == 0);
3178 }
3179 
3180 static int
3181 ztest_dataset_create(char *dsname)
3182 {
3183 	uint64_t zilset = ztest_random(100);
3184 	int err = dmu_objset_create(dsname, DMU_OST_OTHER, 0,
3185 	    ztest_objset_create_cb, NULL);
3186 
3187 	if (err || zilset < 80)
3188 		return (err);
3189 
3190 	if (ztest_opts.zo_verbose >= 6)
3191 		(void) printf("Setting dataset %s to sync always\n", dsname);
3192 	return (ztest_dsl_prop_set_uint64(dsname, ZFS_PROP_SYNC,
3193 	    ZFS_SYNC_ALWAYS, B_FALSE));
3194 }
3195 
3196 /* ARGSUSED */
3197 static int
3198 ztest_objset_destroy_cb(const char *name, void *arg)
3199 {
3200 	objset_t *os;
3201 	dmu_object_info_t doi;
3202 	int error;
3203 
3204 	/*
3205 	 * Verify that the dataset contains a directory object.
3206 	 */
3207 	VERIFY0(dmu_objset_own(name, DMU_OST_OTHER, B_TRUE, FTAG, &os));
3208 	error = dmu_object_info(os, ZTEST_DIROBJ, &doi);
3209 	if (error != ENOENT) {
3210 		/* We could have crashed in the middle of destroying it */
3211 		ASSERT0(error);
3212 		ASSERT3U(doi.doi_type, ==, DMU_OT_ZAP_OTHER);
3213 		ASSERT3S(doi.doi_physical_blocks_512, >=, 0);
3214 	}
3215 	dmu_objset_disown(os, FTAG);
3216 
3217 	/*
3218 	 * Destroy the dataset.
3219 	 */
3220 	if (strchr(name, '@') != NULL) {
3221 		VERIFY0(dsl_destroy_snapshot(name, B_FALSE));
3222 	} else {
3223 		VERIFY0(dsl_destroy_head(name));
3224 	}
3225 	return (0);
3226 }
3227 
3228 static boolean_t
3229 ztest_snapshot_create(char *osname, uint64_t id)
3230 {
3231 	char snapname[ZFS_MAX_DATASET_NAME_LEN];
3232 	int error;
3233 
3234 	(void) snprintf(snapname, sizeof (snapname), "%llu", (u_longlong_t)id);
3235 
3236 	error = dmu_objset_snapshot_one(osname, snapname);
3237 	if (error == ENOSPC) {
3238 		ztest_record_enospc(FTAG);
3239 		return (B_FALSE);
3240 	}
3241 	if (error != 0 && error != EEXIST) {
3242 		fatal(0, "ztest_snapshot_create(%s@%s) = %d", osname,
3243 		    snapname, error);
3244 	}
3245 	return (B_TRUE);
3246 }
3247 
3248 static boolean_t
3249 ztest_snapshot_destroy(char *osname, uint64_t id)
3250 {
3251 	char snapname[ZFS_MAX_DATASET_NAME_LEN];
3252 	int error;
3253 
3254 	(void) snprintf(snapname, sizeof (snapname), "%s@%llu", osname,
3255 	    (u_longlong_t)id);
3256 
3257 	error = dsl_destroy_snapshot(snapname, B_FALSE);
3258 	if (error != 0 && error != ENOENT)
3259 		fatal(0, "ztest_snapshot_destroy(%s) = %d", snapname, error);
3260 	return (B_TRUE);
3261 }
3262 
3263 /* ARGSUSED */
3264 void
3265 ztest_dmu_objset_create_destroy(ztest_ds_t *zd, uint64_t id)
3266 {
3267 	ztest_ds_t zdtmp;
3268 	int iters;
3269 	int error;
3270 	objset_t *os, *os2;
3271 	char name[ZFS_MAX_DATASET_NAME_LEN];
3272 	zilog_t *zilog;
3273 
3274 	(void) rw_rdlock(&ztest_name_lock);
3275 
3276 	(void) snprintf(name, sizeof (name), "%s/temp_%llu",
3277 	    ztest_opts.zo_pool, (u_longlong_t)id);
3278 
3279 	/*
3280 	 * If this dataset exists from a previous run, process its replay log
3281 	 * half of the time.  If we don't replay it, then dmu_objset_destroy()
3282 	 * (invoked from ztest_objset_destroy_cb()) should just throw it away.
3283 	 */
3284 	if (ztest_random(2) == 0 &&
3285 	    dmu_objset_own(name, DMU_OST_OTHER, B_FALSE, FTAG, &os) == 0) {
3286 		ztest_zd_init(&zdtmp, NULL, os);
3287 		zil_replay(os, &zdtmp, ztest_replay_vector);
3288 		ztest_zd_fini(&zdtmp);
3289 		dmu_objset_disown(os, FTAG);
3290 	}
3291 
3292 	/*
3293 	 * There may be an old instance of the dataset we're about to
3294 	 * create lying around from a previous run.  If so, destroy it
3295 	 * and all of its snapshots.
3296 	 */
3297 	(void) dmu_objset_find(name, ztest_objset_destroy_cb, NULL,
3298 	    DS_FIND_CHILDREN | DS_FIND_SNAPSHOTS);
3299 
3300 	/*
3301 	 * Verify that the destroyed dataset is no longer in the namespace.
3302 	 */
3303 	VERIFY3U(ENOENT, ==, dmu_objset_own(name, DMU_OST_OTHER, B_TRUE,
3304 	    FTAG, &os));
3305 
3306 	/*
3307 	 * Verify that we can create a new dataset.
3308 	 */
3309 	error = ztest_dataset_create(name);
3310 	if (error) {
3311 		if (error == ENOSPC) {
3312 			ztest_record_enospc(FTAG);
3313 			(void) rw_unlock(&ztest_name_lock);
3314 			return;
3315 		}
3316 		fatal(0, "dmu_objset_create(%s) = %d", name, error);
3317 	}
3318 
3319 	VERIFY0(dmu_objset_own(name, DMU_OST_OTHER, B_FALSE, FTAG, &os));
3320 
3321 	ztest_zd_init(&zdtmp, NULL, os);
3322 
3323 	/*
3324 	 * Open the intent log for it.
3325 	 */
3326 	zilog = zil_open(os, ztest_get_data);
3327 
3328 	/*
3329 	 * Put some objects in there, do a little I/O to them,
3330 	 * and randomly take a couple of snapshots along the way.
3331 	 */
3332 	iters = ztest_random(5);
3333 	for (int i = 0; i < iters; i++) {
3334 		ztest_dmu_object_alloc_free(&zdtmp, id);
3335 		if (ztest_random(iters) == 0)
3336 			(void) ztest_snapshot_create(name, i);
3337 	}
3338 
3339 	/*
3340 	 * Verify that we cannot create an existing dataset.
3341 	 */
3342 	VERIFY3U(EEXIST, ==,
3343 	    dmu_objset_create(name, DMU_OST_OTHER, 0, NULL, NULL));
3344 
3345 	/*
3346 	 * Verify that we can hold an objset that is also owned.
3347 	 */
3348 	VERIFY3U(0, ==, dmu_objset_hold(name, FTAG, &os2));
3349 	dmu_objset_rele(os2, FTAG);
3350 
3351 	/*
3352 	 * Verify that we cannot own an objset that is already owned.
3353 	 */
3354 	VERIFY3U(EBUSY, ==,
3355 	    dmu_objset_own(name, DMU_OST_OTHER, B_FALSE, FTAG, &os2));
3356 
3357 	zil_close(zilog);
3358 	dmu_objset_disown(os, FTAG);
3359 	ztest_zd_fini(&zdtmp);
3360 
3361 	(void) rw_unlock(&ztest_name_lock);
3362 }
3363 
3364 /*
3365  * Verify that dmu_snapshot_{create,destroy,open,close} work as expected.
3366  */
3367 void
3368 ztest_dmu_snapshot_create_destroy(ztest_ds_t *zd, uint64_t id)
3369 {
3370 	(void) rw_rdlock(&ztest_name_lock);
3371 	(void) ztest_snapshot_destroy(zd->zd_name, id);
3372 	(void) ztest_snapshot_create(zd->zd_name, id);
3373 	(void) rw_unlock(&ztest_name_lock);
3374 }
3375 
3376 /*
3377  * Cleanup non-standard snapshots and clones.
3378  */
3379 void
3380 ztest_dsl_dataset_cleanup(char *osname, uint64_t id)
3381 {
3382 	char snap1name[ZFS_MAX_DATASET_NAME_LEN];
3383 	char clone1name[ZFS_MAX_DATASET_NAME_LEN];
3384 	char snap2name[ZFS_MAX_DATASET_NAME_LEN];
3385 	char clone2name[ZFS_MAX_DATASET_NAME_LEN];
3386 	char snap3name[ZFS_MAX_DATASET_NAME_LEN];
3387 	int error;
3388 
3389 	(void) snprintf(snap1name, sizeof (snap1name),
3390 	    "%s@s1_%llu", osname, id);
3391 	(void) snprintf(clone1name, sizeof (clone1name),
3392 	    "%s/c1_%llu", osname, id);
3393 	(void) snprintf(snap2name, sizeof (snap2name),
3394 	    "%s@s2_%llu", clone1name, id);
3395 	(void) snprintf(clone2name, sizeof (clone2name),
3396 	    "%s/c2_%llu", osname, id);
3397 	(void) snprintf(snap3name, sizeof (snap3name),
3398 	    "%s@s3_%llu", clone1name, id);
3399 
3400 	error = dsl_destroy_head(clone2name);
3401 	if (error && error != ENOENT)
3402 		fatal(0, "dsl_destroy_head(%s) = %d", clone2name, error);
3403 	error = dsl_destroy_snapshot(snap3name, B_FALSE);
3404 	if (error && error != ENOENT)
3405 		fatal(0, "dsl_destroy_snapshot(%s) = %d", snap3name, error);
3406 	error = dsl_destroy_snapshot(snap2name, B_FALSE);
3407 	if (error && error != ENOENT)
3408 		fatal(0, "dsl_destroy_snapshot(%s) = %d", snap2name, error);
3409 	error = dsl_destroy_head(clone1name);
3410 	if (error && error != ENOENT)
3411 		fatal(0, "dsl_destroy_head(%s) = %d", clone1name, error);
3412 	error = dsl_destroy_snapshot(snap1name, B_FALSE);
3413 	if (error && error != ENOENT)
3414 		fatal(0, "dsl_destroy_snapshot(%s) = %d", snap1name, error);
3415 }
3416 
3417 /*
3418  * Verify dsl_dataset_promote handles EBUSY
3419  */
3420 void
3421 ztest_dsl_dataset_promote_busy(ztest_ds_t *zd, uint64_t id)
3422 {
3423 	objset_t *os;
3424 	char snap1name[ZFS_MAX_DATASET_NAME_LEN];
3425 	char clone1name[ZFS_MAX_DATASET_NAME_LEN];
3426 	char snap2name[ZFS_MAX_DATASET_NAME_LEN];
3427 	char clone2name[ZFS_MAX_DATASET_NAME_LEN];
3428 	char snap3name[ZFS_MAX_DATASET_NAME_LEN];
3429 	char *osname = zd->zd_name;
3430 	int error;
3431 
3432 	(void) rw_rdlock(&ztest_name_lock);
3433 
3434 	ztest_dsl_dataset_cleanup(osname, id);
3435 
3436 	(void) snprintf(snap1name, sizeof (snap1name),
3437 	    "%s@s1_%llu", osname, id);
3438 	(void) snprintf(clone1name, sizeof (clone1name),
3439 	    "%s/c1_%llu", osname, id);
3440 	(void) snprintf(snap2name, sizeof (snap2name),
3441 	    "%s@s2_%llu", clone1name, id);
3442 	(void) snprintf(clone2name, sizeof (clone2name),
3443 	    "%s/c2_%llu", osname, id);
3444 	(void) snprintf(snap3name, sizeof (snap3name),
3445 	    "%s@s3_%llu", clone1name, id);
3446 
3447 	error = dmu_objset_snapshot_one(osname, strchr(snap1name, '@') + 1);
3448 	if (error && error != EEXIST) {
3449 		if (error == ENOSPC) {
3450 			ztest_record_enospc(FTAG);
3451 			goto out;
3452 		}
3453 		fatal(0, "dmu_take_snapshot(%s) = %d", snap1name, error);
3454 	}
3455 
3456 	error = dmu_objset_clone(clone1name, snap1name);
3457 	if (error) {
3458 		if (error == ENOSPC) {
3459 			ztest_record_enospc(FTAG);
3460 			goto out;
3461 		}
3462 		fatal(0, "dmu_objset_create(%s) = %d", clone1name, error);
3463 	}
3464 
3465 	error = dmu_objset_snapshot_one(clone1name, strchr(snap2name, '@') + 1);
3466 	if (error && error != EEXIST) {
3467 		if (error == ENOSPC) {
3468 			ztest_record_enospc(FTAG);
3469 			goto out;
3470 		}
3471 		fatal(0, "dmu_open_snapshot(%s) = %d", snap2name, error);
3472 	}
3473 
3474 	error = dmu_objset_snapshot_one(clone1name, strchr(snap3name, '@') + 1);
3475 	if (error && error != EEXIST) {
3476 		if (error == ENOSPC) {
3477 			ztest_record_enospc(FTAG);
3478 			goto out;
3479 		}
3480 		fatal(0, "dmu_open_snapshot(%s) = %d", snap3name, error);
3481 	}
3482 
3483 	error = dmu_objset_clone(clone2name, snap3name);
3484 	if (error) {
3485 		if (error == ENOSPC) {
3486 			ztest_record_enospc(FTAG);
3487 			goto out;
3488 		}
3489 		fatal(0, "dmu_objset_create(%s) = %d", clone2name, error);
3490 	}
3491 
3492 	error = dmu_objset_own(snap2name, DMU_OST_ANY, B_TRUE, FTAG, &os);
3493 	if (error)
3494 		fatal(0, "dmu_objset_own(%s) = %d", snap2name, error);
3495 	error = dsl_dataset_promote(clone2name, NULL);
3496 	if (error == ENOSPC) {
3497 		dmu_objset_disown(os, FTAG);
3498 		ztest_record_enospc(FTAG);
3499 		goto out;
3500 	}
3501 	if (error != EBUSY)
3502 		fatal(0, "dsl_dataset_promote(%s), %d, not EBUSY", clone2name,
3503 		    error);
3504 	dmu_objset_disown(os, FTAG);
3505 
3506 out:
3507 	ztest_dsl_dataset_cleanup(osname, id);
3508 
3509 	(void) rw_unlock(&ztest_name_lock);
3510 }
3511 
3512 /*
3513  * Verify that dmu_object_{alloc,free} work as expected.
3514  */
3515 void
3516 ztest_dmu_object_alloc_free(ztest_ds_t *zd, uint64_t id)
3517 {
3518 	ztest_od_t od[4];
3519 	int batchsize = sizeof (od) / sizeof (od[0]);
3520 
3521 	for (int b = 0; b < batchsize; b++)
3522 		ztest_od_init(&od[b], id, FTAG, b, DMU_OT_UINT64_OTHER, 0, 0);
3523 
3524 	/*
3525 	 * Destroy the previous batch of objects, create a new batch,
3526 	 * and do some I/O on the new objects.
3527 	 */
3528 	if (ztest_object_init(zd, od, sizeof (od), B_TRUE) != 0)
3529 		return;
3530 
3531 	while (ztest_random(4 * batchsize) != 0)
3532 		ztest_io(zd, od[ztest_random(batchsize)].od_object,
3533 		    ztest_random(ZTEST_RANGE_LOCKS) << SPA_MAXBLOCKSHIFT);
3534 }
3535 
3536 /*
3537  * Verify that dmu_{read,write} work as expected.
3538  */
3539 void
3540 ztest_dmu_read_write(ztest_ds_t *zd, uint64_t id)
3541 {
3542 	objset_t *os = zd->zd_os;
3543 	ztest_od_t od[2];
3544 	dmu_tx_t *tx;
3545 	int i, freeit, error;
3546 	uint64_t n, s, txg;
3547 	bufwad_t *packbuf, *bigbuf, *pack, *bigH, *bigT;
3548 	uint64_t packobj, packoff, packsize, bigobj, bigoff, bigsize;
3549 	uint64_t chunksize = (1000 + ztest_random(1000)) * sizeof (uint64_t);
3550 	uint64_t regions = 997;
3551 	uint64_t stride = 123456789ULL;
3552 	uint64_t width = 40;
3553 	int free_percent = 5;
3554 
3555 	/*
3556 	 * This test uses two objects, packobj and bigobj, that are always
3557 	 * updated together (i.e. in the same tx) so that their contents are
3558 	 * in sync and can be compared.  Their contents relate to each other
3559 	 * in a simple way: packobj is a dense array of 'bufwad' structures,
3560 	 * while bigobj is a sparse array of the same bufwads.  Specifically,
3561 	 * for any index n, there are three bufwads that should be identical:
3562 	 *
3563 	 *	packobj, at offset n * sizeof (bufwad_t)
3564 	 *	bigobj, at the head of the nth chunk
3565 	 *	bigobj, at the tail of the nth chunk
3566 	 *
3567 	 * The chunk size is arbitrary. It doesn't have to be a power of two,
3568 	 * and it doesn't have any relation to the object blocksize.
3569 	 * The only requirement is that it can hold at least two bufwads.
3570 	 *
3571 	 * Normally, we write the bufwad to each of these locations.
3572 	 * However, free_percent of the time we instead write zeroes to
3573 	 * packobj and perform a dmu_free_range() on bigobj.  By comparing
3574 	 * bigobj to packobj, we can verify that the DMU is correctly
3575 	 * tracking which parts of an object are allocated and free,
3576 	 * and that the contents of the allocated blocks are correct.
3577 	 */
3578 
3579 	/*
3580 	 * Read the directory info.  If it's the first time, set things up.
3581 	 */
3582 	ztest_od_init(&od[0], id, FTAG, 0, DMU_OT_UINT64_OTHER, 0, chunksize);
3583 	ztest_od_init(&od[1], id, FTAG, 1, DMU_OT_UINT64_OTHER, 0, chunksize);
3584 
3585 	if (ztest_object_init(zd, od, sizeof (od), B_FALSE) != 0)
3586 		return;
3587 
3588 	bigobj = od[0].od_object;
3589 	packobj = od[1].od_object;
3590 	chunksize = od[0].od_gen;
3591 	ASSERT(chunksize == od[1].od_gen);
3592 
3593 	/*
3594 	 * Prefetch a random chunk of the big object.
3595 	 * Our aim here is to get some async reads in flight
3596 	 * for blocks that we may free below; the DMU should
3597 	 * handle this race correctly.
3598 	 */
3599 	n = ztest_random(regions) * stride + ztest_random(width);
3600 	s = 1 + ztest_random(2 * width - 1);
3601 	dmu_prefetch(os, bigobj, 0, n * chunksize, s * chunksize,
3602 	    ZIO_PRIORITY_SYNC_READ);
3603 
3604 	/*
3605 	 * Pick a random index and compute the offsets into packobj and bigobj.
3606 	 */
3607 	n = ztest_random(regions) * stride + ztest_random(width);
3608 	s = 1 + ztest_random(width - 1);
3609 
3610 	packoff = n * sizeof (bufwad_t);
3611 	packsize = s * sizeof (bufwad_t);
3612 
3613 	bigoff = n * chunksize;
3614 	bigsize = s * chunksize;
3615 
3616 	packbuf = umem_alloc(packsize, UMEM_NOFAIL);
3617 	bigbuf = umem_alloc(bigsize, UMEM_NOFAIL);
3618 
3619 	/*
3620 	 * free_percent of the time, free a range of bigobj rather than
3621 	 * overwriting it.
3622 	 */
3623 	freeit = (ztest_random(100) < free_percent);
3624 
3625 	/*
3626 	 * Read the current contents of our objects.
3627 	 */
3628 	error = dmu_read(os, packobj, packoff, packsize, packbuf,
3629 	    DMU_READ_PREFETCH);
3630 	ASSERT0(error);
3631 	error = dmu_read(os, bigobj, bigoff, bigsize, bigbuf,
3632 	    DMU_READ_PREFETCH);
3633 	ASSERT0(error);
3634 
3635 	/*
3636 	 * Get a tx for the mods to both packobj and bigobj.
3637 	 */
3638 	tx = dmu_tx_create(os);
3639 
3640 	dmu_tx_hold_write(tx, packobj, packoff, packsize);
3641 
3642 	if (freeit)
3643 		dmu_tx_hold_free(tx, bigobj, bigoff, bigsize);
3644 	else
3645 		dmu_tx_hold_write(tx, bigobj, bigoff, bigsize);
3646 
3647 	/* This accounts for setting the checksum/compression. */
3648 	dmu_tx_hold_bonus(tx, bigobj);
3649 
3650 	txg = ztest_tx_assign(tx, TXG_MIGHTWAIT, FTAG);
3651 	if (txg == 0) {
3652 		umem_free(packbuf, packsize);
3653 		umem_free(bigbuf, bigsize);
3654 		return;
3655 	}
3656 
3657 	enum zio_checksum cksum;
3658 	do {
3659 		cksum = (enum zio_checksum)
3660 		    ztest_random_dsl_prop(ZFS_PROP_CHECKSUM);
3661 	} while (cksum >= ZIO_CHECKSUM_LEGACY_FUNCTIONS);
3662 	dmu_object_set_checksum(os, bigobj, cksum, tx);
3663 
3664 	enum zio_compress comp;
3665 	do {
3666 		comp = (enum zio_compress)
3667 		    ztest_random_dsl_prop(ZFS_PROP_COMPRESSION);
3668 	} while (comp >= ZIO_COMPRESS_LEGACY_FUNCTIONS);
3669 	dmu_object_set_compress(os, bigobj, comp, tx);
3670 
3671 	/*
3672 	 * For each index from n to n + s, verify that the existing bufwad
3673 	 * in packobj matches the bufwads at the head and tail of the
3674 	 * corresponding chunk in bigobj.  Then update all three bufwads
3675 	 * with the new values we want to write out.
3676 	 */
3677 	for (i = 0; i < s; i++) {
3678 		/* LINTED */
3679 		pack = (bufwad_t *)((char *)packbuf + i * sizeof (bufwad_t));
3680 		/* LINTED */
3681 		bigH = (bufwad_t *)((char *)bigbuf + i * chunksize);
3682 		/* LINTED */
3683 		bigT = (bufwad_t *)((char *)bigH + chunksize) - 1;
3684 
3685 		ASSERT((uintptr_t)bigH - (uintptr_t)bigbuf < bigsize);
3686 		ASSERT((uintptr_t)bigT - (uintptr_t)bigbuf < bigsize);
3687 
3688 		if (pack->bw_txg > txg)
3689 			fatal(0, "future leak: got %llx, open txg is %llx",
3690 			    pack->bw_txg, txg);
3691 
3692 		if (pack->bw_data != 0 && pack->bw_index != n + i)
3693 			fatal(0, "wrong index: got %llx, wanted %llx+%llx",
3694 			    pack->bw_index, n, i);
3695 
3696 		if (bcmp(pack, bigH, sizeof (bufwad_t)) != 0)
3697 			fatal(0, "pack/bigH mismatch in %p/%p", pack, bigH);
3698 
3699 		if (bcmp(pack, bigT, sizeof (bufwad_t)) != 0)
3700 			fatal(0, "pack/bigT mismatch in %p/%p", pack, bigT);
3701 
3702 		if (freeit) {
3703 			bzero(pack, sizeof (bufwad_t));
3704 		} else {
3705 			pack->bw_index = n + i;
3706 			pack->bw_txg = txg;
3707 			pack->bw_data = 1 + ztest_random(-2ULL);
3708 		}
3709 		*bigH = *pack;
3710 		*bigT = *pack;
3711 	}
3712 
3713 	/*
3714 	 * We've verified all the old bufwads, and made new ones.
3715 	 * Now write them out.
3716 	 */
3717 	dmu_write(os, packobj, packoff, packsize, packbuf, tx);
3718 
3719 	if (freeit) {
3720 		if (ztest_opts.zo_verbose >= 7) {
3721 			(void) printf("freeing offset %llx size %llx"
3722 			    " txg %llx\n",
3723 			    (u_longlong_t)bigoff,
3724 			    (u_longlong_t)bigsize,
3725 			    (u_longlong_t)txg);
3726 		}
3727 		VERIFY(0 == dmu_free_range(os, bigobj, bigoff, bigsize, tx));
3728 	} else {
3729 		if (ztest_opts.zo_verbose >= 7) {
3730 			(void) printf("writing offset %llx size %llx"
3731 			    " txg %llx\n",
3732 			    (u_longlong_t)bigoff,
3733 			    (u_longlong_t)bigsize,
3734 			    (u_longlong_t)txg);
3735 		}
3736 		dmu_write(os, bigobj, bigoff, bigsize, bigbuf, tx);
3737 	}
3738 
3739 	dmu_tx_commit(tx);
3740 
3741 	/*
3742 	 * Sanity check the stuff we just wrote.
3743 	 */
3744 	{
3745 		void *packcheck = umem_alloc(packsize, UMEM_NOFAIL);
3746 		void *bigcheck = umem_alloc(bigsize, UMEM_NOFAIL);
3747 
3748 		VERIFY(0 == dmu_read(os, packobj, packoff,
3749 		    packsize, packcheck, DMU_READ_PREFETCH));
3750 		VERIFY(0 == dmu_read(os, bigobj, bigoff,
3751 		    bigsize, bigcheck, DMU_READ_PREFETCH));
3752 
3753 		ASSERT(bcmp(packbuf, packcheck, packsize) == 0);
3754 		ASSERT(bcmp(bigbuf, bigcheck, bigsize) == 0);
3755 
3756 		umem_free(packcheck, packsize);
3757 		umem_free(bigcheck, bigsize);
3758 	}
3759 
3760 	umem_free(packbuf, packsize);
3761 	umem_free(bigbuf, bigsize);
3762 }
3763 
3764 void
3765 compare_and_update_pbbufs(uint64_t s, bufwad_t *packbuf, bufwad_t *bigbuf,
3766     uint64_t bigsize, uint64_t n, uint64_t chunksize, uint64_t txg)
3767 {
3768 	uint64_t i;
3769 	bufwad_t *pack;
3770 	bufwad_t *bigH;
3771 	bufwad_t *bigT;
3772 
3773 	/*
3774 	 * For each index from n to n + s, verify that the existing bufwad
3775 	 * in packobj matches the bufwads at the head and tail of the
3776 	 * corresponding chunk in bigobj.  Then update all three bufwads
3777 	 * with the new values we want to write out.
3778 	 */
3779 	for (i = 0; i < s; i++) {
3780 		/* LINTED */
3781 		pack = (bufwad_t *)((char *)packbuf + i * sizeof (bufwad_t));
3782 		/* LINTED */
3783 		bigH = (bufwad_t *)((char *)bigbuf + i * chunksize);
3784 		/* LINTED */
3785 		bigT = (bufwad_t *)((char *)bigH + chunksize) - 1;
3786 
3787 		ASSERT((uintptr_t)bigH - (uintptr_t)bigbuf < bigsize);
3788 		ASSERT((uintptr_t)bigT - (uintptr_t)bigbuf < bigsize);
3789 
3790 		if (pack->bw_txg > txg)
3791 			fatal(0, "future leak: got %llx, open txg is %llx",
3792 			    pack->bw_txg, txg);
3793 
3794 		if (pack->bw_data != 0 && pack->bw_index != n + i)
3795 			fatal(0, "wrong index: got %llx, wanted %llx+%llx",
3796 			    pack->bw_index, n, i);
3797 
3798 		if (bcmp(pack, bigH, sizeof (bufwad_t)) != 0)
3799 			fatal(0, "pack/bigH mismatch in %p/%p", pack, bigH);
3800 
3801 		if (bcmp(pack, bigT, sizeof (bufwad_t)) != 0)
3802 			fatal(0, "pack/bigT mismatch in %p/%p", pack, bigT);
3803 
3804 		pack->bw_index = n + i;
3805 		pack->bw_txg = txg;
3806 		pack->bw_data = 1 + ztest_random(-2ULL);
3807 
3808 		*bigH = *pack;
3809 		*bigT = *pack;
3810 	}
3811 }
3812 
3813 void
3814 ztest_dmu_read_write_zcopy(ztest_ds_t *zd, uint64_t id)
3815 {
3816 	objset_t *os = zd->zd_os;
3817 	ztest_od_t od[2];
3818 	dmu_tx_t *tx;
3819 	uint64_t i;
3820 	int error;
3821 	uint64_t n, s, txg;
3822 	bufwad_t *packbuf, *bigbuf;
3823 	uint64_t packobj, packoff, packsize, bigobj, bigoff, bigsize;
3824 	uint64_t blocksize = ztest_random_blocksize();
3825 	uint64_t chunksize = blocksize;
3826 	uint64_t regions = 997;
3827 	uint64_t stride = 123456789ULL;
3828 	uint64_t width = 9;
3829 	dmu_buf_t *bonus_db;
3830 	arc_buf_t **bigbuf_arcbufs;
3831 	dmu_object_info_t doi;
3832 
3833 	/*
3834 	 * This test uses two objects, packobj and bigobj, that are always
3835 	 * updated together (i.e. in the same tx) so that their contents are
3836 	 * in sync and can be compared.  Their contents relate to each other
3837 	 * in a simple way: packobj is a dense array of 'bufwad' structures,
3838 	 * while bigobj is a sparse array of the same bufwads.  Specifically,
3839 	 * for any index n, there are three bufwads that should be identical:
3840 	 *
3841 	 *	packobj, at offset n * sizeof (bufwad_t)
3842 	 *	bigobj, at the head of the nth chunk
3843 	 *	bigobj, at the tail of the nth chunk
3844 	 *
3845 	 * The chunk size is set equal to bigobj block size so that
3846 	 * dmu_assign_arcbuf() can be tested for object updates.
3847 	 */
3848 
3849 	/*
3850 	 * Read the directory info.  If it's the first time, set things up.
3851 	 */
3852 	ztest_od_init(&od[0], id, FTAG, 0, DMU_OT_UINT64_OTHER, blocksize, 0);
3853 	ztest_od_init(&od[1], id, FTAG, 1, DMU_OT_UINT64_OTHER, 0, chunksize);
3854 
3855 	if (ztest_object_init(zd, od, sizeof (od), B_FALSE) != 0)
3856 		return;
3857 
3858 	bigobj = od[0].od_object;
3859 	packobj = od[1].od_object;
3860 	blocksize = od[0].od_blocksize;
3861 	chunksize = blocksize;
3862 	ASSERT(chunksize == od[1].od_gen);
3863 
3864 	VERIFY(dmu_object_info(os, bigobj, &doi) == 0);
3865 	VERIFY(ISP2(doi.doi_data_block_size));
3866 	VERIFY(chunksize == doi.doi_data_block_size);
3867 	VERIFY(chunksize >= 2 * sizeof (bufwad_t));
3868 
3869 	/*
3870 	 * Pick a random index and compute the offsets into packobj and bigobj.
3871 	 */
3872 	n = ztest_random(regions) * stride + ztest_random(width);
3873 	s = 1 + ztest_random(width - 1);
3874 
3875 	packoff = n * sizeof (bufwad_t);
3876 	packsize = s * sizeof (bufwad_t);
3877 
3878 	bigoff = n * chunksize;
3879 	bigsize = s * chunksize;
3880 
3881 	packbuf = umem_zalloc(packsize, UMEM_NOFAIL);
3882 	bigbuf = umem_zalloc(bigsize, UMEM_NOFAIL);
3883 
3884 	VERIFY3U(0, ==, dmu_bonus_hold(os, bigobj, FTAG, &bonus_db));
3885 
3886 	bigbuf_arcbufs = umem_zalloc(2 * s * sizeof (arc_buf_t *), UMEM_NOFAIL);
3887 
3888 	/*
3889 	 * Iteration 0 test zcopy for DB_UNCACHED dbufs.
3890 	 * Iteration 1 test zcopy to already referenced dbufs.
3891 	 * Iteration 2 test zcopy to dirty dbuf in the same txg.
3892 	 * Iteration 3 test zcopy to dbuf dirty in previous txg.
3893 	 * Iteration 4 test zcopy when dbuf is no longer dirty.
3894 	 * Iteration 5 test zcopy when it can't be done.
3895 	 * Iteration 6 one more zcopy write.
3896 	 */
3897 	for (i = 0; i < 7; i++) {
3898 		uint64_t j;
3899 		uint64_t off;
3900 
3901 		/*
3902 		 * In iteration 5 (i == 5) use arcbufs
3903 		 * that don't match bigobj blksz to test
3904 		 * dmu_assign_arcbuf() when it can't directly
3905 		 * assign an arcbuf to a dbuf.
3906 		 */
3907 		for (j = 0; j < s; j++) {
3908 			if (i != 5 || chunksize < (SPA_MINBLOCKSIZE * 2)) {
3909 				bigbuf_arcbufs[j] =
3910 				    dmu_request_arcbuf(bonus_db, chunksize);
3911 			} else {
3912 				bigbuf_arcbufs[2 * j] =
3913 				    dmu_request_arcbuf(bonus_db, chunksize / 2);
3914 				bigbuf_arcbufs[2 * j + 1] =
3915 				    dmu_request_arcbuf(bonus_db, chunksize / 2);
3916 			}
3917 		}
3918 
3919 		/*
3920 		 * Get a tx for the mods to both packobj and bigobj.
3921 		 */
3922 		tx = dmu_tx_create(os);
3923 
3924 		dmu_tx_hold_write(tx, packobj, packoff, packsize);
3925 		dmu_tx_hold_write(tx, bigobj, bigoff, bigsize);
3926 
3927 		txg = ztest_tx_assign(tx, TXG_MIGHTWAIT, FTAG);
3928 		if (txg == 0) {
3929 			umem_free(packbuf, packsize);
3930 			umem_free(bigbuf, bigsize);
3931 			for (j = 0; j < s; j++) {
3932 				if (i != 5 ||
3933 				    chunksize < (SPA_MINBLOCKSIZE * 2)) {
3934 					dmu_return_arcbuf(bigbuf_arcbufs[j]);
3935 				} else {
3936 					dmu_return_arcbuf(
3937 					    bigbuf_arcbufs[2 * j]);
3938 					dmu_return_arcbuf(
3939 					    bigbuf_arcbufs[2 * j + 1]);
3940 				}
3941 			}
3942 			umem_free(bigbuf_arcbufs, 2 * s * sizeof (arc_buf_t *));
3943 			dmu_buf_rele(bonus_db, FTAG);
3944 			return;
3945 		}
3946 
3947 		/*
3948 		 * 50% of the time don't read objects in the 1st iteration to
3949 		 * test dmu_assign_arcbuf() for the case when there're no
3950 		 * existing dbufs for the specified offsets.
3951 		 */
3952 		if (i != 0 || ztest_random(2) != 0) {
3953 			error = dmu_read(os, packobj, packoff,
3954 			    packsize, packbuf, DMU_READ_PREFETCH);
3955 			ASSERT0(error);
3956 			error = dmu_read(os, bigobj, bigoff, bigsize,
3957 			    bigbuf, DMU_READ_PREFETCH);
3958 			ASSERT0(error);
3959 		}
3960 		compare_and_update_pbbufs(s, packbuf, bigbuf, bigsize,
3961 		    n, chunksize, txg);
3962 
3963 		/*
3964 		 * We've verified all the old bufwads, and made new ones.
3965 		 * Now write them out.
3966 		 */
3967 		dmu_write(os, packobj, packoff, packsize, packbuf, tx);
3968 		if (ztest_opts.zo_verbose >= 7) {
3969 			(void) printf("writing offset %llx size %llx"
3970 			    " txg %llx\n",
3971 			    (u_longlong_t)bigoff,
3972 			    (u_longlong_t)bigsize,
3973 			    (u_longlong_t)txg);
3974 		}
3975 		for (off = bigoff, j = 0; j < s; j++, off += chunksize) {
3976 			dmu_buf_t *dbt;
3977 			if (i != 5 || chunksize < (SPA_MINBLOCKSIZE * 2)) {
3978 				bcopy((caddr_t)bigbuf + (off - bigoff),
3979 				    bigbuf_arcbufs[j]->b_data, chunksize);
3980 			} else {
3981 				bcopy((caddr_t)bigbuf + (off - bigoff),
3982 				    bigbuf_arcbufs[2 * j]->b_data,
3983 				    chunksize / 2);
3984 				bcopy((caddr_t)bigbuf + (off - bigoff) +
3985 				    chunksize / 2,
3986 				    bigbuf_arcbufs[2 * j + 1]->b_data,
3987 				    chunksize / 2);
3988 			}
3989 
3990 			if (i == 1) {
3991 				VERIFY(dmu_buf_hold(os, bigobj, off,
3992 				    FTAG, &dbt, DMU_READ_NO_PREFETCH) == 0);
3993 			}
3994 			if (i != 5 || chunksize < (SPA_MINBLOCKSIZE * 2)) {
3995 				dmu_assign_arcbuf(bonus_db, off,
3996 				    bigbuf_arcbufs[j], tx);
3997 			} else {
3998 				dmu_assign_arcbuf(bonus_db, off,
3999 				    bigbuf_arcbufs[2 * j], tx);
4000 				dmu_assign_arcbuf(bonus_db,
4001 				    off + chunksize / 2,
4002 				    bigbuf_arcbufs[2 * j + 1], tx);
4003 			}
4004 			if (i == 1) {
4005 				dmu_buf_rele(dbt, FTAG);
4006 			}
4007 		}
4008 		dmu_tx_commit(tx);
4009 
4010 		/*
4011 		 * Sanity check the stuff we just wrote.
4012 		 */
4013 		{
4014 			void *packcheck = umem_alloc(packsize, UMEM_NOFAIL);
4015 			void *bigcheck = umem_alloc(bigsize, UMEM_NOFAIL);
4016 
4017 			VERIFY(0 == dmu_read(os, packobj, packoff,
4018 			    packsize, packcheck, DMU_READ_PREFETCH));
4019 			VERIFY(0 == dmu_read(os, bigobj, bigoff,
4020 			    bigsize, bigcheck, DMU_READ_PREFETCH));
4021 
4022 			ASSERT(bcmp(packbuf, packcheck, packsize) == 0);
4023 			ASSERT(bcmp(bigbuf, bigcheck, bigsize) == 0);
4024 
4025 			umem_free(packcheck, packsize);
4026 			umem_free(bigcheck, bigsize);
4027 		}
4028 		if (i == 2) {
4029 			txg_wait_open(dmu_objset_pool(os), 0);
4030 		} else if (i == 3) {
4031 			txg_wait_synced(dmu_objset_pool(os), 0);
4032 		}
4033 	}
4034 
4035 	dmu_buf_rele(bonus_db, FTAG);
4036 	umem_free(packbuf, packsize);
4037 	umem_free(bigbuf, bigsize);
4038 	umem_free(bigbuf_arcbufs, 2 * s * sizeof (arc_buf_t *));
4039 }
4040 
4041 /* ARGSUSED */
4042 void
4043 ztest_dmu_write_parallel(ztest_ds_t *zd, uint64_t id)
4044 {
4045 	ztest_od_t od[1];
4046 	uint64_t offset = (1ULL << (ztest_random(20) + 43)) +
4047 	    (ztest_random(ZTEST_RANGE_LOCKS) << SPA_MAXBLOCKSHIFT);
4048 
4049 	/*
4050 	 * Have multiple threads write to large offsets in an object
4051 	 * to verify that parallel writes to an object -- even to the
4052 	 * same blocks within the object -- doesn't cause any trouble.
4053 	 */
4054 	ztest_od_init(&od[0], ID_PARALLEL, FTAG, 0, DMU_OT_UINT64_OTHER, 0, 0);
4055 
4056 	if (ztest_object_init(zd, od, sizeof (od), B_FALSE) != 0)
4057 		return;
4058 
4059 	while (ztest_random(10) != 0)
4060 		ztest_io(zd, od[0].od_object, offset);
4061 }
4062 
4063 void
4064 ztest_dmu_prealloc(ztest_ds_t *zd, uint64_t id)
4065 {
4066 	ztest_od_t od[1];
4067 	uint64_t offset = (1ULL << (ztest_random(4) + SPA_MAXBLOCKSHIFT)) +
4068 	    (ztest_random(ZTEST_RANGE_LOCKS) << SPA_MAXBLOCKSHIFT);
4069 	uint64_t count = ztest_random(20) + 1;
4070 	uint64_t blocksize = ztest_random_blocksize();
4071 	void *data;
4072 
4073 	ztest_od_init(&od[0], id, FTAG, 0, DMU_OT_UINT64_OTHER, blocksize, 0);
4074 
4075 	if (ztest_object_init(zd, od, sizeof (od), !ztest_random(2)) != 0)
4076 		return;
4077 
4078 	if (ztest_truncate(zd, od[0].od_object, offset, count * blocksize) != 0)
4079 		return;
4080 
4081 	ztest_prealloc(zd, od[0].od_object, offset, count * blocksize);
4082 
4083 	data = umem_zalloc(blocksize, UMEM_NOFAIL);
4084 
4085 	while (ztest_random(count) != 0) {
4086 		uint64_t randoff = offset + (ztest_random(count) * blocksize);
4087 		if (ztest_write(zd, od[0].od_object, randoff, blocksize,
4088 		    data) != 0)
4089 			break;
4090 		while (ztest_random(4) != 0)
4091 			ztest_io(zd, od[0].od_object, randoff);
4092 	}
4093 
4094 	umem_free(data, blocksize);
4095 }
4096 
4097 /*
4098  * Verify that zap_{create,destroy,add,remove,update} work as expected.
4099  */
4100 #define	ZTEST_ZAP_MIN_INTS	1
4101 #define	ZTEST_ZAP_MAX_INTS	4
4102 #define	ZTEST_ZAP_MAX_PROPS	1000
4103 
4104 void
4105 ztest_zap(ztest_ds_t *zd, uint64_t id)
4106 {
4107 	objset_t *os = zd->zd_os;
4108 	ztest_od_t od[1];
4109 	uint64_t object;
4110 	uint64_t txg, last_txg;
4111 	uint64_t value[ZTEST_ZAP_MAX_INTS];
4112 	uint64_t zl_ints, zl_intsize, prop;
4113 	int i, ints;
4114 	dmu_tx_t *tx;
4115 	char propname[100], txgname[100];
4116 	int error;
4117 	char *hc[2] = { "s.acl.h", ".s.open.h.hyLZlg" };
4118 
4119 	ztest_od_init(&od[0], id, FTAG, 0, DMU_OT_ZAP_OTHER, 0, 0);
4120 
4121 	if (ztest_object_init(zd, od, sizeof (od), !ztest_random(2)) != 0)
4122 		return;
4123 
4124 	object = od[0].od_object;
4125 
4126 	/*
4127 	 * Generate a known hash collision, and verify that
4128 	 * we can lookup and remove both entries.
4129 	 */
4130 	tx = dmu_tx_create(os);
4131 	dmu_tx_hold_zap(tx, object, B_TRUE, NULL);
4132 	txg = ztest_tx_assign(tx, TXG_MIGHTWAIT, FTAG);
4133 	if (txg == 0)
4134 		return;
4135 	for (i = 0; i < 2; i++) {
4136 		value[i] = i;
4137 		VERIFY3U(0, ==, zap_add(os, object, hc[i], sizeof (uint64_t),
4138 		    1, &value[i], tx));
4139 	}
4140 	for (i = 0; i < 2; i++) {
4141 		VERIFY3U(EEXIST, ==, zap_add(os, object, hc[i],
4142 		    sizeof (uint64_t), 1, &value[i], tx));
4143 		VERIFY3U(0, ==,
4144 		    zap_length(os, object, hc[i], &zl_intsize, &zl_ints));
4145 		ASSERT3U(zl_intsize, ==, sizeof (uint64_t));
4146 		ASSERT3U(zl_ints, ==, 1);
4147 	}
4148 	for (i = 0; i < 2; i++) {
4149 		VERIFY3U(0, ==, zap_remove(os, object, hc[i], tx));
4150 	}
4151 	dmu_tx_commit(tx);
4152 
4153 	/*
4154 	 * Generate a buch of random entries.
4155 	 */
4156 	ints = MAX(ZTEST_ZAP_MIN_INTS, object % ZTEST_ZAP_MAX_INTS);
4157 
4158 	prop = ztest_random(ZTEST_ZAP_MAX_PROPS);
4159 	(void) sprintf(propname, "prop_%llu", (u_longlong_t)prop);
4160 	(void) sprintf(txgname, "txg_%llu", (u_longlong_t)prop);
4161 	bzero(value, sizeof (value));
4162 	last_txg = 0;
4163 
4164 	/*
4165 	 * If these zap entries already exist, validate their contents.
4166 	 */
4167 	error = zap_length(os, object, txgname, &zl_intsize, &zl_ints);
4168 	if (error == 0) {
4169 		ASSERT3U(zl_intsize, ==, sizeof (uint64_t));
4170 		ASSERT3U(zl_ints, ==, 1);
4171 
4172 		VERIFY(zap_lookup(os, object, txgname, zl_intsize,
4173 		    zl_ints, &last_txg) == 0);
4174 
4175 		VERIFY(zap_length(os, object, propname, &zl_intsize,
4176 		    &zl_ints) == 0);
4177 
4178 		ASSERT3U(zl_intsize, ==, sizeof (uint64_t));
4179 		ASSERT3U(zl_ints, ==, ints);
4180 
4181 		VERIFY(zap_lookup(os, object, propname, zl_intsize,
4182 		    zl_ints, value) == 0);
4183 
4184 		for (i = 0; i < ints; i++) {
4185 			ASSERT3U(value[i], ==, last_txg + object + i);
4186 		}
4187 	} else {
4188 		ASSERT3U(error, ==, ENOENT);
4189 	}
4190 
4191 	/*
4192 	 * Atomically update two entries in our zap object.
4193 	 * The first is named txg_%llu, and contains the txg
4194 	 * in which the property was last updated.  The second
4195 	 * is named prop_%llu, and the nth element of its value
4196 	 * should be txg + object + n.
4197 	 */
4198 	tx = dmu_tx_create(os);
4199 	dmu_tx_hold_zap(tx, object, B_TRUE, NULL);
4200 	txg = ztest_tx_assign(tx, TXG_MIGHTWAIT, FTAG);
4201 	if (txg == 0)
4202 		return;
4203 
4204 	if (last_txg > txg)
4205 		fatal(0, "zap future leak: old %llu new %llu", last_txg, txg);
4206 
4207 	for (i = 0; i < ints; i++)
4208 		value[i] = txg + object + i;
4209 
4210 	VERIFY3U(0, ==, zap_update(os, object, txgname, sizeof (uint64_t),
4211 	    1, &txg, tx));
4212 	VERIFY3U(0, ==, zap_update(os, object, propname, sizeof (uint64_t),
4213 	    ints, value, tx));
4214 
4215 	dmu_tx_commit(tx);
4216 
4217 	/*
4218 	 * Remove a random pair of entries.
4219 	 */
4220 	prop = ztest_random(ZTEST_ZAP_MAX_PROPS);
4221 	(void) sprintf(propname, "prop_%llu", (u_longlong_t)prop);
4222 	(void) sprintf(txgname, "txg_%llu", (u_longlong_t)prop);
4223 
4224 	error = zap_length(os, object, txgname, &zl_intsize, &zl_ints);
4225 
4226 	if (error == ENOENT)
4227 		return;
4228 
4229 	ASSERT0(error);
4230 
4231 	tx = dmu_tx_create(os);
4232 	dmu_tx_hold_zap(tx, object, B_TRUE, NULL);
4233 	txg = ztest_tx_assign(tx, TXG_MIGHTWAIT, FTAG);
4234 	if (txg == 0)
4235 		return;
4236 	VERIFY3U(0, ==, zap_remove(os, object, txgname, tx));
4237 	VERIFY3U(0, ==, zap_remove(os, object, propname, tx));
4238 	dmu_tx_commit(tx);
4239 }
4240 
4241 /*
4242  * Testcase to test the upgrading of a microzap to fatzap.
4243  */
4244 void
4245 ztest_fzap(ztest_ds_t *zd, uint64_t id)
4246 {
4247 	objset_t *os = zd->zd_os;
4248 	ztest_od_t od[1];
4249 	uint64_t object, txg;
4250 
4251 	ztest_od_init(&od[0], id, FTAG, 0, DMU_OT_ZAP_OTHER, 0, 0);
4252 
4253 	if (ztest_object_init(zd, od, sizeof (od), !ztest_random(2)) != 0)
4254 		return;
4255 
4256 	object = od[0].od_object;
4257 
4258 	/*
4259 	 * Add entries to this ZAP and make sure it spills over
4260 	 * and gets upgraded to a fatzap. Also, since we are adding
4261 	 * 2050 entries we should see ptrtbl growth and leaf-block split.
4262 	 */
4263 	for (int i = 0; i < 2050; i++) {
4264 		char name[ZFS_MAX_DATASET_NAME_LEN];
4265 		uint64_t value = i;
4266 		dmu_tx_t *tx;
4267 		int error;
4268 
4269 		(void) snprintf(name, sizeof (name), "fzap-%llu-%llu",
4270 		    id, value);
4271 
4272 		tx = dmu_tx_create(os);
4273 		dmu_tx_hold_zap(tx, object, B_TRUE, name);
4274 		txg = ztest_tx_assign(tx, TXG_MIGHTWAIT, FTAG);
4275 		if (txg == 0)
4276 			return;
4277 		error = zap_add(os, object, name, sizeof (uint64_t), 1,
4278 		    &value, tx);
4279 		ASSERT(error == 0 || error == EEXIST);
4280 		dmu_tx_commit(tx);
4281 	}
4282 }
4283 
4284 /* ARGSUSED */
4285 void
4286 ztest_zap_parallel(ztest_ds_t *zd, uint64_t id)
4287 {
4288 	objset_t *os = zd->zd_os;
4289 	ztest_od_t od[1];
4290 	uint64_t txg, object, count, wsize, wc, zl_wsize, zl_wc;
4291 	dmu_tx_t *tx;
4292 	int i, namelen, error;
4293 	int micro = ztest_random(2);
4294 	char name[20], string_value[20];
4295 	void *data;
4296 
4297 	ztest_od_init(&od[0], ID_PARALLEL, FTAG, micro, DMU_OT_ZAP_OTHER, 0, 0);
4298 
4299 	if (ztest_object_init(zd, od, sizeof (od), B_FALSE) != 0)
4300 		return;
4301 
4302 	object = od[0].od_object;
4303 
4304 	/*
4305 	 * Generate a random name of the form 'xxx.....' where each
4306 	 * x is a random printable character and the dots are dots.
4307 	 * There are 94 such characters, and the name length goes from
4308 	 * 6 to 20, so there are 94^3 * 15 = 12,458,760 possible names.
4309 	 */
4310 	namelen = ztest_random(sizeof (name) - 5) + 5 + 1;
4311 
4312 	for (i = 0; i < 3; i++)
4313 		name[i] = '!' + ztest_random('~' - '!' + 1);
4314 	for (; i < namelen - 1; i++)
4315 		name[i] = '.';
4316 	name[i] = '\0';
4317 
4318 	if ((namelen & 1) || micro) {
4319 		wsize = sizeof (txg);
4320 		wc = 1;
4321 		data = &txg;
4322 	} else {
4323 		wsize = 1;
4324 		wc = namelen;
4325 		data = string_value;
4326 	}
4327 
4328 	count = -1ULL;
4329 	VERIFY0(zap_count(os, object, &count));
4330 	ASSERT(count != -1ULL);
4331 
4332 	/*
4333 	 * Select an operation: length, lookup, add, update, remove.
4334 	 */
4335 	i = ztest_random(5);
4336 
4337 	if (i >= 2) {
4338 		tx = dmu_tx_create(os);
4339 		dmu_tx_hold_zap(tx, object, B_TRUE, NULL);
4340 		txg = ztest_tx_assign(tx, TXG_MIGHTWAIT, FTAG);
4341 		if (txg == 0)
4342 			return;
4343 		bcopy(name, string_value, namelen);
4344 	} else {
4345 		tx = NULL;
4346 		txg = 0;
4347 		bzero(string_value, namelen);
4348 	}
4349 
4350 	switch (i) {
4351 
4352 	case 0:
4353 		error = zap_length(os, object, name, &zl_wsize, &zl_wc);
4354 		if (error == 0) {
4355 			ASSERT3U(wsize, ==, zl_wsize);
4356 			ASSERT3U(wc, ==, zl_wc);
4357 		} else {
4358 			ASSERT3U(error, ==, ENOENT);
4359 		}
4360 		break;
4361 
4362 	case 1:
4363 		error = zap_lookup(os, object, name, wsize, wc, data);
4364 		if (error == 0) {
4365 			if (data == string_value &&
4366 			    bcmp(name, data, namelen) != 0)
4367 				fatal(0, "name '%s' != val '%s' len %d",
4368 				    name, data, namelen);
4369 		} else {
4370 			ASSERT3U(error, ==, ENOENT);
4371 		}
4372 		break;
4373 
4374 	case 2:
4375 		error = zap_add(os, object, name, wsize, wc, data, tx);
4376 		ASSERT(error == 0 || error == EEXIST);
4377 		break;
4378 
4379 	case 3:
4380 		VERIFY(zap_update(os, object, name, wsize, wc, data, tx) == 0);
4381 		break;
4382 
4383 	case 4:
4384 		error = zap_remove(os, object, name, tx);
4385 		ASSERT(error == 0 || error == ENOENT);
4386 		break;
4387 	}
4388 
4389 	if (tx != NULL)
4390 		dmu_tx_commit(tx);
4391 }
4392 
4393 /*
4394  * Commit callback data.
4395  */
4396 typedef struct ztest_cb_data {
4397 	list_node_t		zcd_node;
4398 	uint64_t		zcd_txg;
4399 	int			zcd_expected_err;
4400 	boolean_t		zcd_added;
4401 	boolean_t		zcd_called;
4402 	spa_t			*zcd_spa;
4403 } ztest_cb_data_t;
4404 
4405 /* This is the actual commit callback function */
4406 static void
4407 ztest_commit_callback(void *arg, int error)
4408 {
4409 	ztest_cb_data_t *data = arg;
4410 	uint64_t synced_txg;
4411 
4412 	VERIFY(data != NULL);
4413 	VERIFY3S(data->zcd_expected_err, ==, error);
4414 	VERIFY(!data->zcd_called);
4415 
4416 	synced_txg = spa_last_synced_txg(data->zcd_spa);
4417 	if (data->zcd_txg > synced_txg)
4418 		fatal(0, "commit callback of txg %" PRIu64 " called prematurely"
4419 		    ", last synced txg = %" PRIu64 "\n", data->zcd_txg,
4420 		    synced_txg);
4421 
4422 	data->zcd_called = B_TRUE;
4423 
4424 	if (error == ECANCELED) {
4425 		ASSERT0(data->zcd_txg);
4426 		ASSERT(!data->zcd_added);
4427 
4428 		/*
4429 		 * The private callback data should be destroyed here, but
4430 		 * since we are going to check the zcd_called field after
4431 		 * dmu_tx_abort(), we will destroy it there.
4432 		 */
4433 		return;
4434 	}
4435 
4436 	/* Was this callback added to the global callback list? */
4437 	if (!data->zcd_added)
4438 		goto out;
4439 
4440 	ASSERT3U(data->zcd_txg, !=, 0);
4441 
4442 	/* Remove our callback from the list */
4443 	(void) mutex_lock(&zcl.zcl_callbacks_lock);
4444 	list_remove(&zcl.zcl_callbacks, data);
4445 	(void) mutex_unlock(&zcl.zcl_callbacks_lock);
4446 
4447 out:
4448 	umem_free(data, sizeof (ztest_cb_data_t));
4449 }
4450 
4451 /* Allocate and initialize callback data structure */
4452 static ztest_cb_data_t *
4453 ztest_create_cb_data(objset_t *os, uint64_t txg)
4454 {
4455 	ztest_cb_data_t *cb_data;
4456 
4457 	cb_data = umem_zalloc(sizeof (ztest_cb_data_t), UMEM_NOFAIL);
4458 
4459 	cb_data->zcd_txg = txg;
4460 	cb_data->zcd_spa = dmu_objset_spa(os);
4461 
4462 	return (cb_data);
4463 }
4464 
4465 /*
4466  * If a number of txgs equal to this threshold have been created after a commit
4467  * callback has been registered but not called, then we assume there is an
4468  * implementation bug.
4469  */
4470 #define	ZTEST_COMMIT_CALLBACK_THRESH	(TXG_CONCURRENT_STATES + 2)
4471 
4472 /*
4473  * Commit callback test.
4474  */
4475 void
4476 ztest_dmu_commit_callbacks(ztest_ds_t *zd, uint64_t id)
4477 {
4478 	objset_t *os = zd->zd_os;
4479 	ztest_od_t od[1];
4480 	dmu_tx_t *tx;
4481 	ztest_cb_data_t *cb_data[3], *tmp_cb;
4482 	uint64_t old_txg, txg;
4483 	int i, error;
4484 
4485 	ztest_od_init(&od[0], id, FTAG, 0, DMU_OT_UINT64_OTHER, 0, 0);
4486 
4487 	if (ztest_object_init(zd, od, sizeof (od), B_FALSE) != 0)
4488 		return;
4489 
4490 	tx = dmu_tx_create(os);
4491 
4492 	cb_data[0] = ztest_create_cb_data(os, 0);
4493 	dmu_tx_callback_register(tx, ztest_commit_callback, cb_data[0]);
4494 
4495 	dmu_tx_hold_write(tx, od[0].od_object, 0, sizeof (uint64_t));
4496 
4497 	/* Every once in a while, abort the transaction on purpose */
4498 	if (ztest_random(100) == 0)
4499 		error = -1;
4500 
4501 	if (!error)
4502 		error = dmu_tx_assign(tx, TXG_NOWAIT);
4503 
4504 	txg = error ? 0 : dmu_tx_get_txg(tx);
4505 
4506 	cb_data[0]->zcd_txg = txg;
4507 	cb_data[1] = ztest_create_cb_data(os, txg);
4508 	dmu_tx_callback_register(tx, ztest_commit_callback, cb_data[1]);
4509 
4510 	if (error) {
4511 		/*
4512 		 * It's not a strict requirement to call the registered
4513 		 * callbacks from inside dmu_tx_abort(), but that's what
4514 		 * it's supposed to happen in the current implementation
4515 		 * so we will check for that.
4516 		 */
4517 		for (i = 0; i < 2; i++) {
4518 			cb_data[i]->zcd_expected_err = ECANCELED;
4519 			VERIFY(!cb_data[i]->zcd_called);
4520 		}
4521 
4522 		dmu_tx_abort(tx);
4523 
4524 		for (i = 0; i < 2; i++) {
4525 			VERIFY(cb_data[i]->zcd_called);
4526 			umem_free(cb_data[i], sizeof (ztest_cb_data_t));
4527 		}
4528 
4529 		return;
4530 	}
4531 
4532 	cb_data[2] = ztest_create_cb_data(os, txg);
4533 	dmu_tx_callback_register(tx, ztest_commit_callback, cb_data[2]);
4534 
4535 	/*
4536 	 * Read existing data to make sure there isn't a future leak.
4537 	 */
4538 	VERIFY(0 == dmu_read(os, od[0].od_object, 0, sizeof (uint64_t),
4539 	    &old_txg, DMU_READ_PREFETCH));
4540 
4541 	if (old_txg > txg)
4542 		fatal(0, "future leak: got %" PRIu64 ", open txg is %" PRIu64,
4543 		    old_txg, txg);
4544 
4545 	dmu_write(os, od[0].od_object, 0, sizeof (uint64_t), &txg, tx);
4546 
4547 	(void) mutex_lock(&zcl.zcl_callbacks_lock);
4548 
4549 	/*
4550 	 * Since commit callbacks don't have any ordering requirement and since
4551 	 * it is theoretically possible for a commit callback to be called
4552 	 * after an arbitrary amount of time has elapsed since its txg has been
4553 	 * synced, it is difficult to reliably determine whether a commit
4554 	 * callback hasn't been called due to high load or due to a flawed
4555 	 * implementation.
4556 	 *
4557 	 * In practice, we will assume that if after a certain number of txgs a
4558 	 * commit callback hasn't been called, then most likely there's an
4559 	 * implementation bug..
4560 	 */
4561 	tmp_cb = list_head(&zcl.zcl_callbacks);
4562 	if (tmp_cb != NULL &&
4563 	    (txg - ZTEST_COMMIT_CALLBACK_THRESH) > tmp_cb->zcd_txg) {
4564 		fatal(0, "Commit callback threshold exceeded, oldest txg: %"
4565 		    PRIu64 ", open txg: %" PRIu64 "\n", tmp_cb->zcd_txg, txg);
4566 	}
4567 
4568 	/*
4569 	 * Let's find the place to insert our callbacks.
4570 	 *
4571 	 * Even though the list is ordered by txg, it is possible for the
4572 	 * insertion point to not be the end because our txg may already be
4573 	 * quiescing at this point and other callbacks in the open txg
4574 	 * (from other objsets) may have sneaked in.
4575 	 */
4576 	tmp_cb = list_tail(&zcl.zcl_callbacks);
4577 	while (tmp_cb != NULL && tmp_cb->zcd_txg > txg)
4578 		tmp_cb = list_prev(&zcl.zcl_callbacks, tmp_cb);
4579 
4580 	/* Add the 3 callbacks to the list */
4581 	for (i = 0; i < 3; i++) {
4582 		if (tmp_cb == NULL)
4583 			list_insert_head(&zcl.zcl_callbacks, cb_data[i]);
4584 		else
4585 			list_insert_after(&zcl.zcl_callbacks, tmp_cb,
4586 			    cb_data[i]);
4587 
4588 		cb_data[i]->zcd_added = B_TRUE;
4589 		VERIFY(!cb_data[i]->zcd_called);
4590 
4591 		tmp_cb = cb_data[i];
4592 	}
4593 
4594 	(void) mutex_unlock(&zcl.zcl_callbacks_lock);
4595 
4596 	dmu_tx_commit(tx);
4597 }
4598 
4599 /* ARGSUSED */
4600 void
4601 ztest_dsl_prop_get_set(ztest_ds_t *zd, uint64_t id)
4602 {
4603 	zfs_prop_t proplist[] = {
4604 		ZFS_PROP_CHECKSUM,
4605 		ZFS_PROP_COMPRESSION,
4606 		ZFS_PROP_COPIES,
4607 		ZFS_PROP_DEDUP
4608 	};
4609 
4610 	(void) rw_rdlock(&ztest_name_lock);
4611 
4612 	for (int p = 0; p < sizeof (proplist) / sizeof (proplist[0]); p++)
4613 		(void) ztest_dsl_prop_set_uint64(zd->zd_name, proplist[p],
4614 		    ztest_random_dsl_prop(proplist[p]), (int)ztest_random(2));
4615 
4616 	(void) rw_unlock(&ztest_name_lock);
4617 }
4618 
4619 /* ARGSUSED */
4620 void
4621 ztest_spa_prop_get_set(ztest_ds_t *zd, uint64_t id)
4622 {
4623 	nvlist_t *props = NULL;
4624 
4625 	(void) rw_rdlock(&ztest_name_lock);
4626 
4627 	(void) ztest_spa_prop_set_uint64(ZPOOL_PROP_DEDUPDITTO,
4628 	    ZIO_DEDUPDITTO_MIN + ztest_random(ZIO_DEDUPDITTO_MIN));
4629 
4630 	VERIFY0(spa_prop_get(ztest_spa, &props));
4631 
4632 	if (ztest_opts.zo_verbose >= 6)
4633 		dump_nvlist(props, 4);
4634 
4635 	nvlist_free(props);
4636 
4637 	(void) rw_unlock(&ztest_name_lock);
4638 }
4639 
4640 static int
4641 user_release_one(const char *snapname, const char *holdname)
4642 {
4643 	nvlist_t *snaps, *holds;
4644 	int error;
4645 
4646 	snaps = fnvlist_alloc();
4647 	holds = fnvlist_alloc();
4648 	fnvlist_add_boolean(holds, holdname);
4649 	fnvlist_add_nvlist(snaps, snapname, holds);
4650 	fnvlist_free(holds);
4651 	error = dsl_dataset_user_release(snaps, NULL);
4652 	fnvlist_free(snaps);
4653 	return (error);
4654 }
4655 
4656 /*
4657  * Test snapshot hold/release and deferred destroy.
4658  */
4659 void
4660 ztest_dmu_snapshot_hold(ztest_ds_t *zd, uint64_t id)
4661 {
4662 	int error;
4663 	objset_t *os = zd->zd_os;
4664 	objset_t *origin;
4665 	char snapname[100];
4666 	char fullname[100];
4667 	char clonename[100];
4668 	char tag[100];
4669 	char osname[ZFS_MAX_DATASET_NAME_LEN];
4670 	nvlist_t *holds;
4671 
4672 	(void) rw_rdlock(&ztest_name_lock);
4673 
4674 	dmu_objset_name(os, osname);
4675 
4676 	(void) snprintf(snapname, sizeof (snapname), "sh1_%llu", id);
4677 	(void) snprintf(fullname, sizeof (fullname), "%s@%s", osname, snapname);
4678 	(void) snprintf(clonename, sizeof (clonename),
4679 	    "%s/ch1_%llu", osname, id);
4680 	(void) snprintf(tag, sizeof (tag), "tag_%llu", id);
4681 
4682 	/*
4683 	 * Clean up from any previous run.
4684 	 */
4685 	error = dsl_destroy_head(clonename);
4686 	if (error != ENOENT)
4687 		ASSERT0(error);
4688 	error = user_release_one(fullname, tag);
4689 	if (error != ESRCH && error != ENOENT)
4690 		ASSERT0(error);
4691 	error = dsl_destroy_snapshot(fullname, B_FALSE);
4692 	if (error != ENOENT)
4693 		ASSERT0(error);
4694 
4695 	/*
4696 	 * Create snapshot, clone it, mark snap for deferred destroy,
4697 	 * destroy clone, verify snap was also destroyed.
4698 	 */
4699 	error = dmu_objset_snapshot_one(osname, snapname);
4700 	if (error) {
4701 		if (error == ENOSPC) {
4702 			ztest_record_enospc("dmu_objset_snapshot");
4703 			goto out;
4704 		}
4705 		fatal(0, "dmu_objset_snapshot(%s) = %d", fullname, error);
4706 	}
4707 
4708 	error = dmu_objset_clone(clonename, fullname);
4709 	if (error) {
4710 		if (error == ENOSPC) {
4711 			ztest_record_enospc("dmu_objset_clone");
4712 			goto out;
4713 		}
4714 		fatal(0, "dmu_objset_clone(%s) = %d", clonename, error);
4715 	}
4716 
4717 	error = dsl_destroy_snapshot(fullname, B_TRUE);
4718 	if (error) {
4719 		fatal(0, "dsl_destroy_snapshot(%s, B_TRUE) = %d",
4720 		    fullname, error);
4721 	}
4722 
4723 	error = dsl_destroy_head(clonename);
4724 	if (error)
4725 		fatal(0, "dsl_destroy_head(%s) = %d", clonename, error);
4726 
4727 	error = dmu_objset_hold(fullname, FTAG, &origin);
4728 	if (error != ENOENT)
4729 		fatal(0, "dmu_objset_hold(%s) = %d", fullname, error);
4730 
4731 	/*
4732 	 * Create snapshot, add temporary hold, verify that we can't
4733 	 * destroy a held snapshot, mark for deferred destroy,
4734 	 * release hold, verify snapshot was destroyed.
4735 	 */
4736 	error = dmu_objset_snapshot_one(osname, snapname);
4737 	if (error) {
4738 		if (error == ENOSPC) {
4739 			ztest_record_enospc("dmu_objset_snapshot");
4740 			goto out;
4741 		}
4742 		fatal(0, "dmu_objset_snapshot(%s) = %d", fullname, error);
4743 	}
4744 
4745 	holds = fnvlist_alloc();
4746 	fnvlist_add_string(holds, fullname, tag);
4747 	error = dsl_dataset_user_hold(holds, 0, NULL);
4748 	fnvlist_free(holds);
4749 
4750 	if (error == ENOSPC) {
4751 		ztest_record_enospc("dsl_dataset_user_hold");
4752 		goto out;
4753 	} else if (error) {
4754 		fatal(0, "dsl_dataset_user_hold(%s, %s) = %u",
4755 		    fullname, tag, error);
4756 	}
4757 
4758 	error = dsl_destroy_snapshot(fullname, B_FALSE);
4759 	if (error != EBUSY) {
4760 		fatal(0, "dsl_destroy_snapshot(%s, B_FALSE) = %d",
4761 		    fullname, error);
4762 	}
4763 
4764 	error = dsl_destroy_snapshot(fullname, B_TRUE);
4765 	if (error) {
4766 		fatal(0, "dsl_destroy_snapshot(%s, B_TRUE) = %d",
4767 		    fullname, error);
4768 	}
4769 
4770 	error = user_release_one(fullname, tag);
4771 	if (error)
4772 		fatal(0, "user_release_one(%s, %s) = %d", fullname, tag, error);
4773 
4774 	VERIFY3U(dmu_objset_hold(fullname, FTAG, &origin), ==, ENOENT);
4775 
4776 out:
4777 	(void) rw_unlock(&ztest_name_lock);
4778 }
4779 
4780 /*
4781  * Inject random faults into the on-disk data.
4782  */
4783 /* ARGSUSED */
4784 void
4785 ztest_fault_inject(ztest_ds_t *zd, uint64_t id)
4786 {
4787 	ztest_shared_t *zs = ztest_shared;
4788 	spa_t *spa = ztest_spa;
4789 	int fd;
4790 	uint64_t offset;
4791 	uint64_t leaves;
4792 	uint64_t bad = 0x1990c0ffeedecade;
4793 	uint64_t top, leaf;
4794 	char path0[MAXPATHLEN];
4795 	char pathrand[MAXPATHLEN];
4796 	size_t fsize;
4797 	int bshift = SPA_MAXBLOCKSHIFT + 2;	/* don't scrog all labels */
4798 	int iters = 1000;
4799 	int maxfaults;
4800 	int mirror_save;
4801 	vdev_t *vd0 = NULL;
4802 	uint64_t guid0 = 0;
4803 	boolean_t islog = B_FALSE;
4804 
4805 	VERIFY(mutex_lock(&ztest_vdev_lock) == 0);
4806 	maxfaults = MAXFAULTS();
4807 	leaves = MAX(zs->zs_mirrors, 1) * ztest_opts.zo_raidz;
4808 	mirror_save = zs->zs_mirrors;
4809 	VERIFY(mutex_unlock(&ztest_vdev_lock) == 0);
4810 
4811 	ASSERT(leaves >= 1);
4812 
4813 	/*
4814 	 * Grab the name lock as reader. There are some operations
4815 	 * which don't like to have their vdevs changed while
4816 	 * they are in progress (i.e. spa_change_guid). Those
4817 	 * operations will have grabbed the name lock as writer.
4818 	 */
4819 	(void) rw_rdlock(&ztest_name_lock);
4820 
4821 	/*
4822 	 * We need SCL_STATE here because we're going to look at vd0->vdev_tsd.
4823 	 */
4824 	spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
4825 
4826 	if (ztest_random(2) == 0) {
4827 		/*
4828 		 * Inject errors on a normal data device or slog device.
4829 		 */
4830 		top = ztest_random_vdev_top(spa, B_TRUE);
4831 		leaf = ztest_random(leaves) + zs->zs_splits;
4832 
4833 		/*
4834 		 * Generate paths to the first leaf in this top-level vdev,
4835 		 * and to the random leaf we selected.  We'll induce transient
4836 		 * write failures and random online/offline activity on leaf 0,
4837 		 * and we'll write random garbage to the randomly chosen leaf.
4838 		 */
4839 		(void) snprintf(path0, sizeof (path0), ztest_dev_template,
4840 		    ztest_opts.zo_dir, ztest_opts.zo_pool,
4841 		    top * leaves + zs->zs_splits);
4842 		(void) snprintf(pathrand, sizeof (pathrand), ztest_dev_template,
4843 		    ztest_opts.zo_dir, ztest_opts.zo_pool,
4844 		    top * leaves + leaf);
4845 
4846 		vd0 = vdev_lookup_by_path(spa->spa_root_vdev, path0);
4847 		if (vd0 != NULL && vd0->vdev_top->vdev_islog)
4848 			islog = B_TRUE;
4849 
4850 		/*
4851 		 * If the top-level vdev needs to be resilvered
4852 		 * then we only allow faults on the device that is
4853 		 * resilvering.
4854 		 */
4855 		if (vd0 != NULL && maxfaults != 1 &&
4856 		    (!vdev_resilver_needed(vd0->vdev_top, NULL, NULL) ||
4857 		    vd0->vdev_resilver_txg != 0)) {
4858 			/*
4859 			 * Make vd0 explicitly claim to be unreadable,
4860 			 * or unwriteable, or reach behind its back
4861 			 * and close the underlying fd.  We can do this if
4862 			 * maxfaults == 0 because we'll fail and reexecute,
4863 			 * and we can do it if maxfaults >= 2 because we'll
4864 			 * have enough redundancy.  If maxfaults == 1, the
4865 			 * combination of this with injection of random data
4866 			 * corruption below exceeds the pool's fault tolerance.
4867 			 */
4868 			vdev_file_t *vf = vd0->vdev_tsd;
4869 
4870 			if (vf != NULL && ztest_random(3) == 0) {
4871 				(void) close(vf->vf_vnode->v_fd);
4872 				vf->vf_vnode->v_fd = -1;
4873 			} else if (ztest_random(2) == 0) {
4874 				vd0->vdev_cant_read = B_TRUE;
4875 			} else {
4876 				vd0->vdev_cant_write = B_TRUE;
4877 			}
4878 			guid0 = vd0->vdev_guid;
4879 		}
4880 	} else {
4881 		/*
4882 		 * Inject errors on an l2cache device.
4883 		 */
4884 		spa_aux_vdev_t *sav = &spa->spa_l2cache;
4885 
4886 		if (sav->sav_count == 0) {
4887 			spa_config_exit(spa, SCL_STATE, FTAG);
4888 			(void) rw_unlock(&ztest_name_lock);
4889 			return;
4890 		}
4891 		vd0 = sav->sav_vdevs[ztest_random(sav->sav_count)];
4892 		guid0 = vd0->vdev_guid;
4893 		(void) strcpy(path0, vd0->vdev_path);
4894 		(void) strcpy(pathrand, vd0->vdev_path);
4895 
4896 		leaf = 0;
4897 		leaves = 1;
4898 		maxfaults = INT_MAX;	/* no limit on cache devices */
4899 	}
4900 
4901 	spa_config_exit(spa, SCL_STATE, FTAG);
4902 	(void) rw_unlock(&ztest_name_lock);
4903 
4904 	/*
4905 	 * If we can tolerate two or more faults, or we're dealing
4906 	 * with a slog, randomly online/offline vd0.
4907 	 */
4908 	if ((maxfaults >= 2 || islog) && guid0 != 0) {
4909 		if (ztest_random(10) < 6) {
4910 			int flags = (ztest_random(2) == 0 ?
4911 			    ZFS_OFFLINE_TEMPORARY : 0);
4912 
4913 			/*
4914 			 * We have to grab the zs_name_lock as writer to
4915 			 * prevent a race between offlining a slog and
4916 			 * destroying a dataset. Offlining the slog will
4917 			 * grab a reference on the dataset which may cause
4918 			 * dmu_objset_destroy() to fail with EBUSY thus
4919 			 * leaving the dataset in an inconsistent state.
4920 			 */
4921 			if (islog)
4922 				(void) rw_wrlock(&ztest_name_lock);
4923 
4924 			VERIFY(vdev_offline(spa, guid0, flags) != EBUSY);
4925 
4926 			if (islog)
4927 				(void) rw_unlock(&ztest_name_lock);
4928 		} else {
4929 			/*
4930 			 * Ideally we would like to be able to randomly
4931 			 * call vdev_[on|off]line without holding locks
4932 			 * to force unpredictable failures but the side
4933 			 * effects of vdev_[on|off]line prevent us from
4934 			 * doing so. We grab the ztest_vdev_lock here to
4935 			 * prevent a race between injection testing and
4936 			 * aux_vdev removal.
4937 			 */
4938 			VERIFY(mutex_lock(&ztest_vdev_lock) == 0);
4939 			(void) vdev_online(spa, guid0, 0, NULL);
4940 			VERIFY(mutex_unlock(&ztest_vdev_lock) == 0);
4941 		}
4942 	}
4943 
4944 	if (maxfaults == 0)
4945 		return;
4946 
4947 	/*
4948 	 * We have at least single-fault tolerance, so inject data corruption.
4949 	 */
4950 	fd = open(pathrand, O_RDWR);
4951 
4952 	if (fd == -1)	/* we hit a gap in the device namespace */
4953 		return;
4954 
4955 	fsize = lseek(fd, 0, SEEK_END);
4956 
4957 	while (--iters != 0) {
4958 		/*
4959 		 * The offset must be chosen carefully to ensure that
4960 		 * we do not inject a given logical block with errors
4961 		 * on two different leaf devices, because ZFS can not
4962 		 * tolerate that (if maxfaults==1).
4963 		 *
4964 		 * We divide each leaf into chunks of size
4965 		 * (# leaves * SPA_MAXBLOCKSIZE * 4).  Within each chunk
4966 		 * there is a series of ranges to which we can inject errors.
4967 		 * Each range can accept errors on only a single leaf vdev.
4968 		 * The error injection ranges are separated by ranges
4969 		 * which we will not inject errors on any device (DMZs).
4970 		 * Each DMZ must be large enough such that a single block
4971 		 * can not straddle it, so that a single block can not be
4972 		 * a target in two different injection ranges (on different
4973 		 * leaf vdevs).
4974 		 *
4975 		 * For example, with 3 leaves, each chunk looks like:
4976 		 *    0 to  32M: injection range for leaf 0
4977 		 *  32M to  64M: DMZ - no injection allowed
4978 		 *  64M to  96M: injection range for leaf 1
4979 		 *  96M to 128M: DMZ - no injection allowed
4980 		 * 128M to 160M: injection range for leaf 2
4981 		 * 160M to 192M: DMZ - no injection allowed
4982 		 */
4983 		offset = ztest_random(fsize / (leaves << bshift)) *
4984 		    (leaves << bshift) + (leaf << bshift) +
4985 		    (ztest_random(1ULL << (bshift - 1)) & -8ULL);
4986 
4987 		if (offset >= fsize)
4988 			continue;
4989 
4990 		VERIFY(mutex_lock(&ztest_vdev_lock) == 0);
4991 		if (mirror_save != zs->zs_mirrors) {
4992 			VERIFY(mutex_unlock(&ztest_vdev_lock) == 0);
4993 			(void) close(fd);
4994 			return;
4995 		}
4996 
4997 		if (pwrite(fd, &bad, sizeof (bad), offset) != sizeof (bad))
4998 			fatal(1, "can't inject bad word at 0x%llx in %s",
4999 			    offset, pathrand);
5000 
5001 		VERIFY(mutex_unlock(&ztest_vdev_lock) == 0);
5002 
5003 		if (ztest_opts.zo_verbose >= 7)
5004 			(void) printf("injected bad word into %s,"
5005 			    " offset 0x%llx\n", pathrand, (u_longlong_t)offset);
5006 	}
5007 
5008 	(void) close(fd);
5009 }
5010 
5011 /*
5012  * Verify that DDT repair works as expected.
5013  */
5014 void
5015 ztest_ddt_repair(ztest_ds_t *zd, uint64_t id)
5016 {
5017 	ztest_shared_t *zs = ztest_shared;
5018 	spa_t *spa = ztest_spa;
5019 	objset_t *os = zd->zd_os;
5020 	ztest_od_t od[1];
5021 	uint64_t object, blocksize, txg, pattern, psize;
5022 	enum zio_checksum checksum = spa_dedup_checksum(spa);
5023 	dmu_buf_t *db;
5024 	dmu_tx_t *tx;
5025 	void *buf;
5026 	blkptr_t blk;
5027 	int copies = 2 * ZIO_DEDUPDITTO_MIN;
5028 
5029 	blocksize = ztest_random_blocksize();
5030 	blocksize = MIN(blocksize, 2048);	/* because we write so many */
5031 
5032 	ztest_od_init(&od[0], id, FTAG, 0, DMU_OT_UINT64_OTHER, blocksize, 0);
5033 
5034 	if (ztest_object_init(zd, od, sizeof (od), B_FALSE) != 0)
5035 		return;
5036 
5037 	/*
5038 	 * Take the name lock as writer to prevent anyone else from changing
5039 	 * the pool and dataset properies we need to maintain during this test.
5040 	 */
5041 	(void) rw_wrlock(&ztest_name_lock);
5042 
5043 	if (ztest_dsl_prop_set_uint64(zd->zd_name, ZFS_PROP_DEDUP, checksum,
5044 	    B_FALSE) != 0 ||
5045 	    ztest_dsl_prop_set_uint64(zd->zd_name, ZFS_PROP_COPIES, 1,
5046 	    B_FALSE) != 0) {
5047 		(void) rw_unlock(&ztest_name_lock);
5048 		return;
5049 	}
5050 
5051 	object = od[0].od_object;
5052 	blocksize = od[0].od_blocksize;
5053 	pattern = zs->zs_guid ^ dmu_objset_fsid_guid(os);
5054 
5055 	ASSERT(object != 0);
5056 
5057 	tx = dmu_tx_create(os);
5058 	dmu_tx_hold_write(tx, object, 0, copies * blocksize);
5059 	txg = ztest_tx_assign(tx, TXG_WAIT, FTAG);
5060 	if (txg == 0) {
5061 		(void) rw_unlock(&ztest_name_lock);
5062 		return;
5063 	}
5064 
5065 	/*
5066 	 * Write all the copies of our block.
5067 	 */
5068 	for (int i = 0; i < copies; i++) {
5069 		uint64_t offset = i * blocksize;
5070 		int error = dmu_buf_hold(os, object, offset, FTAG, &db,
5071 		    DMU_READ_NO_PREFETCH);
5072 		if (error != 0) {
5073 			fatal(B_FALSE, "dmu_buf_hold(%p, %llu, %llu) = %u",
5074 			    os, (long long)object, (long long) offset, error);
5075 		}
5076 		ASSERT(db->db_offset == offset);
5077 		ASSERT(db->db_size == blocksize);
5078 		ASSERT(ztest_pattern_match(db->db_data, db->db_size, pattern) ||
5079 		    ztest_pattern_match(db->db_data, db->db_size, 0ULL));
5080 		dmu_buf_will_fill(db, tx);
5081 		ztest_pattern_set(db->db_data, db->db_size, pattern);
5082 		dmu_buf_rele(db, FTAG);
5083 	}
5084 
5085 	dmu_tx_commit(tx);
5086 	txg_wait_synced(spa_get_dsl(spa), txg);
5087 
5088 	/*
5089 	 * Find out what block we got.
5090 	 */
5091 	VERIFY0(dmu_buf_hold(os, object, 0, FTAG, &db,
5092 	    DMU_READ_NO_PREFETCH));
5093 	blk = *((dmu_buf_impl_t *)db)->db_blkptr;
5094 	dmu_buf_rele(db, FTAG);
5095 
5096 	/*
5097 	 * Damage the block.  Dedup-ditto will save us when we read it later.
5098 	 */
5099 	psize = BP_GET_PSIZE(&blk);
5100 	buf = zio_buf_alloc(psize);
5101 	ztest_pattern_set(buf, psize, ~pattern);
5102 
5103 	(void) zio_wait(zio_rewrite(NULL, spa, 0, &blk,
5104 	    buf, psize, NULL, NULL, ZIO_PRIORITY_SYNC_WRITE,
5105 	    ZIO_FLAG_CANFAIL | ZIO_FLAG_INDUCE_DAMAGE, NULL));
5106 
5107 	zio_buf_free(buf, psize);
5108 
5109 	(void) rw_unlock(&ztest_name_lock);
5110 }
5111 
5112 /*
5113  * Scrub the pool.
5114  */
5115 /* ARGSUSED */
5116 void
5117 ztest_scrub(ztest_ds_t *zd, uint64_t id)
5118 {
5119 	spa_t *spa = ztest_spa;
5120 
5121 	(void) spa_scan(spa, POOL_SCAN_SCRUB);
5122 	(void) poll(NULL, 0, 100); /* wait a moment, then force a restart */
5123 	(void) spa_scan(spa, POOL_SCAN_SCRUB);
5124 }
5125 
5126 /*
5127  * Change the guid for the pool.
5128  */
5129 /* ARGSUSED */
5130 void
5131 ztest_reguid(ztest_ds_t *zd, uint64_t id)
5132 {
5133 	spa_t *spa = ztest_spa;
5134 	uint64_t orig, load;
5135 	int error;
5136 
5137 	orig = spa_guid(spa);
5138 	load = spa_load_guid(spa);
5139 
5140 	(void) rw_wrlock(&ztest_name_lock);
5141 	error = spa_change_guid(spa);
5142 	(void) rw_unlock(&ztest_name_lock);
5143 
5144 	if (error != 0)
5145 		return;
5146 
5147 	if (ztest_opts.zo_verbose >= 4) {
5148 		(void) printf("Changed guid old %llu -> %llu\n",
5149 		    (u_longlong_t)orig, (u_longlong_t)spa_guid(spa));
5150 	}
5151 
5152 	VERIFY3U(orig, !=, spa_guid(spa));
5153 	VERIFY3U(load, ==, spa_load_guid(spa));
5154 }
5155 
5156 /*
5157  * Rename the pool to a different name and then rename it back.
5158  */
5159 /* ARGSUSED */
5160 void
5161 ztest_spa_rename(ztest_ds_t *zd, uint64_t id)
5162 {
5163 	char *oldname, *newname;
5164 	spa_t *spa;
5165 
5166 	(void) rw_wrlock(&ztest_name_lock);
5167 
5168 	oldname = ztest_opts.zo_pool;
5169 	newname = umem_alloc(strlen(oldname) + 5, UMEM_NOFAIL);
5170 	(void) strcpy(newname, oldname);
5171 	(void) strcat(newname, "_tmp");
5172 
5173 	/*
5174 	 * Do the rename
5175 	 */
5176 	VERIFY3U(0, ==, spa_rename(oldname, newname));
5177 
5178 	/*
5179 	 * Try to open it under the old name, which shouldn't exist
5180 	 */
5181 	VERIFY3U(ENOENT, ==, spa_open(oldname, &spa, FTAG));
5182 
5183 	/*
5184 	 * Open it under the new name and make sure it's still the same spa_t.
5185 	 */
5186 	VERIFY3U(0, ==, spa_open(newname, &spa, FTAG));
5187 
5188 	ASSERT(spa == ztest_spa);
5189 	spa_close(spa, FTAG);
5190 
5191 	/*
5192 	 * Rename it back to the original
5193 	 */
5194 	VERIFY3U(0, ==, spa_rename(newname, oldname));
5195 
5196 	/*
5197 	 * Make sure it can still be opened
5198 	 */
5199 	VERIFY3U(0, ==, spa_open(oldname, &spa, FTAG));
5200 
5201 	ASSERT(spa == ztest_spa);
5202 	spa_close(spa, FTAG);
5203 
5204 	umem_free(newname, strlen(newname) + 1);
5205 
5206 	(void) rw_unlock(&ztest_name_lock);
5207 }
5208 
5209 /*
5210  * Verify pool integrity by running zdb.
5211  */
5212 static void
5213 ztest_run_zdb(char *pool)
5214 {
5215 	int status;
5216 	char zdb[MAXPATHLEN + MAXNAMELEN + 20];
5217 	char zbuf[1024];
5218 	char *bin;
5219 	char *ztest;
5220 	char *isa;
5221 	int isalen;
5222 	FILE *fp;
5223 
5224 	(void) realpath(getexecname(), zdb);
5225 
5226 	/* zdb lives in /usr/sbin, while ztest lives in /usr/bin */
5227 	bin = strstr(zdb, "/usr/bin/");
5228 	ztest = strstr(bin, "/ztest");
5229 	isa = bin + 8;
5230 	isalen = ztest - isa;
5231 	isa = strdup(isa);
5232 	/* LINTED */
5233 	(void) sprintf(bin,
5234 	    "/usr/sbin%.*s/zdb -bcc%s%s -d -U %s %s",
5235 	    isalen,
5236 	    isa,
5237 	    ztest_opts.zo_verbose >= 3 ? "s" : "",
5238 	    ztest_opts.zo_verbose >= 4 ? "v" : "",
5239 	    spa_config_path,
5240 	    pool);
5241 	free(isa);
5242 
5243 	if (ztest_opts.zo_verbose >= 5)
5244 		(void) printf("Executing %s\n", strstr(zdb, "zdb "));
5245 
5246 	fp = popen(zdb, "r");
5247 
5248 	while (fgets(zbuf, sizeof (zbuf), fp) != NULL)
5249 		if (ztest_opts.zo_verbose >= 3)
5250 			(void) printf("%s", zbuf);
5251 
5252 	status = pclose(fp);
5253 
5254 	if (status == 0)
5255 		return;
5256 
5257 	ztest_dump_core = 0;
5258 	if (WIFEXITED(status))
5259 		fatal(0, "'%s' exit code %d", zdb, WEXITSTATUS(status));
5260 	else
5261 		fatal(0, "'%s' died with signal %d", zdb, WTERMSIG(status));
5262 }
5263 
5264 static void
5265 ztest_walk_pool_directory(char *header)
5266 {
5267 	spa_t *spa = NULL;
5268 
5269 	if (ztest_opts.zo_verbose >= 6)
5270 		(void) printf("%s\n", header);
5271 
5272 	mutex_enter(&spa_namespace_lock);
5273 	while ((spa = spa_next(spa)) != NULL)
5274 		if (ztest_opts.zo_verbose >= 6)
5275 			(void) printf("\t%s\n", spa_name(spa));
5276 	mutex_exit(&spa_namespace_lock);
5277 }
5278 
5279 static void
5280 ztest_spa_import_export(char *oldname, char *newname)
5281 {
5282 	nvlist_t *config, *newconfig;
5283 	uint64_t pool_guid;
5284 	spa_t *spa;
5285 	int error;
5286 
5287 	if (ztest_opts.zo_verbose >= 4) {
5288 		(void) printf("import/export: old = %s, new = %s\n",
5289 		    oldname, newname);
5290 	}
5291 
5292 	/*
5293 	 * Clean up from previous runs.
5294 	 */
5295 	(void) spa_destroy(newname);
5296 
5297 	/*
5298 	 * Get the pool's configuration and guid.
5299 	 */
5300 	VERIFY3U(0, ==, spa_open(oldname, &spa, FTAG));
5301 
5302 	/*
5303 	 * Kick off a scrub to tickle scrub/export races.
5304 	 */
5305 	if (ztest_random(2) == 0)
5306 		(void) spa_scan(spa, POOL_SCAN_SCRUB);
5307 
5308 	pool_guid = spa_guid(spa);
5309 	spa_close(spa, FTAG);
5310 
5311 	ztest_walk_pool_directory("pools before export");
5312 
5313 	/*
5314 	 * Export it.
5315 	 */
5316 	VERIFY3U(0, ==, spa_export(oldname, &config, B_FALSE, B_FALSE));
5317 
5318 	ztest_walk_pool_directory("pools after export");
5319 
5320 	/*
5321 	 * Try to import it.
5322 	 */
5323 	newconfig = spa_tryimport(config);
5324 	ASSERT(newconfig != NULL);
5325 	nvlist_free(newconfig);
5326 
5327 	/*
5328 	 * Import it under the new name.
5329 	 */
5330 	error = spa_import(newname, config, NULL, 0);
5331 	if (error != 0) {
5332 		dump_nvlist(config, 0);
5333 		fatal(B_FALSE, "couldn't import pool %s as %s: error %u",
5334 		    oldname, newname, error);
5335 	}
5336 
5337 	ztest_walk_pool_directory("pools after import");
5338 
5339 	/*
5340 	 * Try to import it again -- should fail with EEXIST.
5341 	 */
5342 	VERIFY3U(EEXIST, ==, spa_import(newname, config, NULL, 0));
5343 
5344 	/*
5345 	 * Try to import it under a different name -- should fail with EEXIST.
5346 	 */
5347 	VERIFY3U(EEXIST, ==, spa_import(oldname, config, NULL, 0));
5348 
5349 	/*
5350 	 * Verify that the pool is no longer visible under the old name.
5351 	 */
5352 	VERIFY3U(ENOENT, ==, spa_open(oldname, &spa, FTAG));
5353 
5354 	/*
5355 	 * Verify that we can open and close the pool using the new name.
5356 	 */
5357 	VERIFY3U(0, ==, spa_open(newname, &spa, FTAG));
5358 	ASSERT(pool_guid == spa_guid(spa));
5359 	spa_close(spa, FTAG);
5360 
5361 	nvlist_free(config);
5362 }
5363 
5364 static void
5365 ztest_resume(spa_t *spa)
5366 {
5367 	if (spa_suspended(spa) && ztest_opts.zo_verbose >= 6)
5368 		(void) printf("resuming from suspended state\n");
5369 	spa_vdev_state_enter(spa, SCL_NONE);
5370 	vdev_clear(spa, NULL);
5371 	(void) spa_vdev_state_exit(spa, NULL, 0);
5372 	(void) zio_resume(spa);
5373 }
5374 
5375 static void *
5376 ztest_resume_thread(void *arg)
5377 {
5378 	spa_t *spa = arg;
5379 
5380 	while (!ztest_exiting) {
5381 		if (spa_suspended(spa))
5382 			ztest_resume(spa);
5383 		(void) poll(NULL, 0, 100);
5384 	}
5385 	return (NULL);
5386 }
5387 
5388 static void *
5389 ztest_deadman_thread(void *arg)
5390 {
5391 	ztest_shared_t *zs = arg;
5392 	spa_t *spa = ztest_spa;
5393 	hrtime_t delta, total = 0;
5394 
5395 	for (;;) {
5396 		delta = zs->zs_thread_stop - zs->zs_thread_start +
5397 		    MSEC2NSEC(zfs_deadman_synctime_ms);
5398 
5399 		(void) poll(NULL, 0, (int)NSEC2MSEC(delta));
5400 
5401 		/*
5402 		 * If the pool is suspended then fail immediately. Otherwise,
5403 		 * check to see if the pool is making any progress. If
5404 		 * vdev_deadman() discovers that there hasn't been any recent
5405 		 * I/Os then it will end up aborting the tests.
5406 		 */
5407 		if (spa_suspended(spa) || spa->spa_root_vdev == NULL) {
5408 			fatal(0, "aborting test after %llu seconds because "
5409 			    "pool has transitioned to a suspended state.",
5410 			    zfs_deadman_synctime_ms / 1000);
5411 			return (NULL);
5412 		}
5413 		vdev_deadman(spa->spa_root_vdev);
5414 
5415 		total += zfs_deadman_synctime_ms/1000;
5416 		(void) printf("ztest has been running for %lld seconds\n",
5417 		    total);
5418 	}
5419 }
5420 
5421 static void
5422 ztest_execute(int test, ztest_info_t *zi, uint64_t id)
5423 {
5424 	ztest_ds_t *zd = &ztest_ds[id % ztest_opts.zo_datasets];
5425 	ztest_shared_callstate_t *zc = ZTEST_GET_SHARED_CALLSTATE(test);
5426 	hrtime_t functime = gethrtime();
5427 
5428 	for (int i = 0; i < zi->zi_iters; i++)
5429 		zi->zi_func(zd, id);
5430 
5431 	functime = gethrtime() - functime;
5432 
5433 	atomic_add_64(&zc->zc_count, 1);
5434 	atomic_add_64(&zc->zc_time, functime);
5435 
5436 	if (ztest_opts.zo_verbose >= 4) {
5437 		Dl_info dli;
5438 		(void) dladdr((void *)zi->zi_func, &dli);
5439 		(void) printf("%6.2f sec in %s\n",
5440 		    (double)functime / NANOSEC, dli.dli_sname);
5441 	}
5442 }
5443 
5444 static void *
5445 ztest_thread(void *arg)
5446 {
5447 	int rand;
5448 	uint64_t id = (uintptr_t)arg;
5449 	ztest_shared_t *zs = ztest_shared;
5450 	uint64_t call_next;
5451 	hrtime_t now;
5452 	ztest_info_t *zi;
5453 	ztest_shared_callstate_t *zc;
5454 
5455 	while ((now = gethrtime()) < zs->zs_thread_stop) {
5456 		/*
5457 		 * See if it's time to force a crash.
5458 		 */
5459 		if (now > zs->zs_thread_kill)
5460 			ztest_kill(zs);
5461 
5462 		/*
5463 		 * If we're getting ENOSPC with some regularity, stop.
5464 		 */
5465 		if (zs->zs_enospc_count > 10)
5466 			break;
5467 
5468 		/*
5469 		 * Pick a random function to execute.
5470 		 */
5471 		rand = ztest_random(ZTEST_FUNCS);
5472 		zi = &ztest_info[rand];
5473 		zc = ZTEST_GET_SHARED_CALLSTATE(rand);
5474 		call_next = zc->zc_next;
5475 
5476 		if (now >= call_next &&
5477 		    atomic_cas_64(&zc->zc_next, call_next, call_next +
5478 		    ztest_random(2 * zi->zi_interval[0] + 1)) == call_next) {
5479 			ztest_execute(rand, zi, id);
5480 		}
5481 	}
5482 
5483 	return (NULL);
5484 }
5485 
5486 static void
5487 ztest_dataset_name(char *dsname, char *pool, int d)
5488 {
5489 	(void) snprintf(dsname, ZFS_MAX_DATASET_NAME_LEN, "%s/ds_%d", pool, d);
5490 }
5491 
5492 static void
5493 ztest_dataset_destroy(int d)
5494 {
5495 	char name[ZFS_MAX_DATASET_NAME_LEN];
5496 
5497 	ztest_dataset_name(name, ztest_opts.zo_pool, d);
5498 
5499 	if (ztest_opts.zo_verbose >= 3)
5500 		(void) printf("Destroying %s to free up space\n", name);
5501 
5502 	/*
5503 	 * Cleanup any non-standard clones and snapshots.  In general,
5504 	 * ztest thread t operates on dataset (t % zopt_datasets),
5505 	 * so there may be more than one thing to clean up.
5506 	 */
5507 	for (int t = d; t < ztest_opts.zo_threads;
5508 	    t += ztest_opts.zo_datasets) {
5509 		ztest_dsl_dataset_cleanup(name, t);
5510 	}
5511 
5512 	(void) dmu_objset_find(name, ztest_objset_destroy_cb, NULL,
5513 	    DS_FIND_SNAPSHOTS | DS_FIND_CHILDREN);
5514 }
5515 
5516 static void
5517 ztest_dataset_dirobj_verify(ztest_ds_t *zd)
5518 {
5519 	uint64_t usedobjs, dirobjs, scratch;
5520 
5521 	/*
5522 	 * ZTEST_DIROBJ is the object directory for the entire dataset.
5523 	 * Therefore, the number of objects in use should equal the
5524 	 * number of ZTEST_DIROBJ entries, +1 for ZTEST_DIROBJ itself.
5525 	 * If not, we have an object leak.
5526 	 *
5527 	 * Note that we can only check this in ztest_dataset_open(),
5528 	 * when the open-context and syncing-context values agree.
5529 	 * That's because zap_count() returns the open-context value,
5530 	 * while dmu_objset_space() returns the rootbp fill count.
5531 	 */
5532 	VERIFY3U(0, ==, zap_count(zd->zd_os, ZTEST_DIROBJ, &dirobjs));
5533 	dmu_objset_space(zd->zd_os, &scratch, &scratch, &usedobjs, &scratch);
5534 	ASSERT3U(dirobjs + 1, ==, usedobjs);
5535 }
5536 
5537 static int
5538 ztest_dataset_open(int d)
5539 {
5540 	ztest_ds_t *zd = &ztest_ds[d];
5541 	uint64_t committed_seq = ZTEST_GET_SHARED_DS(d)->zd_seq;
5542 	objset_t *os;
5543 	zilog_t *zilog;
5544 	char name[ZFS_MAX_DATASET_NAME_LEN];
5545 	int error;
5546 
5547 	ztest_dataset_name(name, ztest_opts.zo_pool, d);
5548 
5549 	(void) rw_rdlock(&ztest_name_lock);
5550 
5551 	error = ztest_dataset_create(name);
5552 	if (error == ENOSPC) {
5553 		(void) rw_unlock(&ztest_name_lock);
5554 		ztest_record_enospc(FTAG);
5555 		return (error);
5556 	}
5557 	ASSERT(error == 0 || error == EEXIST);
5558 
5559 	VERIFY0(dmu_objset_own(name, DMU_OST_OTHER, B_FALSE, zd, &os));
5560 	(void) rw_unlock(&ztest_name_lock);
5561 
5562 	ztest_zd_init(zd, ZTEST_GET_SHARED_DS(d), os);
5563 
5564 	zilog = zd->zd_zilog;
5565 
5566 	if (zilog->zl_header->zh_claim_lr_seq != 0 &&
5567 	    zilog->zl_header->zh_claim_lr_seq < committed_seq)
5568 		fatal(0, "missing log records: claimed %llu < committed %llu",
5569 		    zilog->zl_header->zh_claim_lr_seq, committed_seq);
5570 
5571 	ztest_dataset_dirobj_verify(zd);
5572 
5573 	zil_replay(os, zd, ztest_replay_vector);
5574 
5575 	ztest_dataset_dirobj_verify(zd);
5576 
5577 	if (ztest_opts.zo_verbose >= 6)
5578 		(void) printf("%s replay %llu blocks, %llu records, seq %llu\n",
5579 		    zd->zd_name,
5580 		    (u_longlong_t)zilog->zl_parse_blk_count,
5581 		    (u_longlong_t)zilog->zl_parse_lr_count,
5582 		    (u_longlong_t)zilog->zl_replaying_seq);
5583 
5584 	zilog = zil_open(os, ztest_get_data);
5585 
5586 	if (zilog->zl_replaying_seq != 0 &&
5587 	    zilog->zl_replaying_seq < committed_seq)
5588 		fatal(0, "missing log records: replayed %llu < committed %llu",
5589 		    zilog->zl_replaying_seq, committed_seq);
5590 
5591 	return (0);
5592 }
5593 
5594 static void
5595 ztest_dataset_close(int d)
5596 {
5597 	ztest_ds_t *zd = &ztest_ds[d];
5598 
5599 	zil_close(zd->zd_zilog);
5600 	dmu_objset_disown(zd->zd_os, zd);
5601 
5602 	ztest_zd_fini(zd);
5603 }
5604 
5605 /*
5606  * Kick off threads to run tests on all datasets in parallel.
5607  */
5608 static void
5609 ztest_run(ztest_shared_t *zs)
5610 {
5611 	thread_t *tid;
5612 	spa_t *spa;
5613 	objset_t *os;
5614 	thread_t resume_tid;
5615 	int error;
5616 
5617 	ztest_exiting = B_FALSE;
5618 
5619 	/*
5620 	 * Initialize parent/child shared state.
5621 	 */
5622 	VERIFY(_mutex_init(&ztest_vdev_lock, USYNC_THREAD, NULL) == 0);
5623 	VERIFY(rwlock_init(&ztest_name_lock, USYNC_THREAD, NULL) == 0);
5624 
5625 	zs->zs_thread_start = gethrtime();
5626 	zs->zs_thread_stop =
5627 	    zs->zs_thread_start + ztest_opts.zo_passtime * NANOSEC;
5628 	zs->zs_thread_stop = MIN(zs->zs_thread_stop, zs->zs_proc_stop);
5629 	zs->zs_thread_kill = zs->zs_thread_stop;
5630 	if (ztest_random(100) < ztest_opts.zo_killrate) {
5631 		zs->zs_thread_kill -=
5632 		    ztest_random(ztest_opts.zo_passtime * NANOSEC);
5633 	}
5634 
5635 	(void) _mutex_init(&zcl.zcl_callbacks_lock, USYNC_THREAD, NULL);
5636 
5637 	list_create(&zcl.zcl_callbacks, sizeof (ztest_cb_data_t),
5638 	    offsetof(ztest_cb_data_t, zcd_node));
5639 
5640 	/*
5641 	 * Open our pool.
5642 	 */
5643 	kernel_init(FREAD | FWRITE);
5644 	VERIFY0(spa_open(ztest_opts.zo_pool, &spa, FTAG));
5645 	spa->spa_debug = B_TRUE;
5646 	metaslab_preload_limit = ztest_random(20) + 1;
5647 	ztest_spa = spa;
5648 
5649 	VERIFY0(dmu_objset_own(ztest_opts.zo_pool,
5650 	    DMU_OST_ANY, B_TRUE, FTAG, &os));
5651 	zs->zs_guid = dmu_objset_fsid_guid(os);
5652 	dmu_objset_disown(os, FTAG);
5653 
5654 	spa->spa_dedup_ditto = 2 * ZIO_DEDUPDITTO_MIN;
5655 
5656 	/*
5657 	 * We don't expect the pool to suspend unless maxfaults == 0,
5658 	 * in which case ztest_fault_inject() temporarily takes away
5659 	 * the only valid replica.
5660 	 */
5661 	if (MAXFAULTS() == 0)
5662 		spa->spa_failmode = ZIO_FAILURE_MODE_WAIT;
5663 	else
5664 		spa->spa_failmode = ZIO_FAILURE_MODE_PANIC;
5665 
5666 	/*
5667 	 * Create a thread to periodically resume suspended I/O.
5668 	 */
5669 	VERIFY(thr_create(0, 0, ztest_resume_thread, spa, THR_BOUND,
5670 	    &resume_tid) == 0);
5671 
5672 	/*
5673 	 * Create a deadman thread to abort() if we hang.
5674 	 */
5675 	VERIFY(thr_create(0, 0, ztest_deadman_thread, zs, THR_BOUND,
5676 	    NULL) == 0);
5677 
5678 	/*
5679 	 * Verify that we can safely inquire about about any object,
5680 	 * whether it's allocated or not.  To make it interesting,
5681 	 * we probe a 5-wide window around each power of two.
5682 	 * This hits all edge cases, including zero and the max.
5683 	 */
5684 	for (int t = 0; t < 64; t++) {
5685 		for (int d = -5; d <= 5; d++) {
5686 			error = dmu_object_info(spa->spa_meta_objset,
5687 			    (1ULL << t) + d, NULL);
5688 			ASSERT(error == 0 || error == ENOENT ||
5689 			    error == EINVAL);
5690 		}
5691 	}
5692 
5693 	/*
5694 	 * If we got any ENOSPC errors on the previous run, destroy something.
5695 	 */
5696 	if (zs->zs_enospc_count != 0) {
5697 		int d = ztest_random(ztest_opts.zo_datasets);
5698 		ztest_dataset_destroy(d);
5699 	}
5700 	zs->zs_enospc_count = 0;
5701 
5702 	tid = umem_zalloc(ztest_opts.zo_threads * sizeof (thread_t),
5703 	    UMEM_NOFAIL);
5704 
5705 	if (ztest_opts.zo_verbose >= 4)
5706 		(void) printf("starting main threads...\n");
5707 
5708 	/*
5709 	 * Kick off all the tests that run in parallel.
5710 	 */
5711 	for (int t = 0; t < ztest_opts.zo_threads; t++) {
5712 		if (t < ztest_opts.zo_datasets &&
5713 		    ztest_dataset_open(t) != 0)
5714 			return;
5715 		VERIFY(thr_create(0, 0, ztest_thread, (void *)(uintptr_t)t,
5716 		    THR_BOUND, &tid[t]) == 0);
5717 	}
5718 
5719 	/*
5720 	 * Wait for all of the tests to complete.  We go in reverse order
5721 	 * so we don't close datasets while threads are still using them.
5722 	 */
5723 	for (int t = ztest_opts.zo_threads - 1; t >= 0; t--) {
5724 		VERIFY(thr_join(tid[t], NULL, NULL) == 0);
5725 		if (t < ztest_opts.zo_datasets)
5726 			ztest_dataset_close(t);
5727 	}
5728 
5729 	txg_wait_synced(spa_get_dsl(spa), 0);
5730 
5731 	zs->zs_alloc = metaslab_class_get_alloc(spa_normal_class(spa));
5732 	zs->zs_space = metaslab_class_get_space(spa_normal_class(spa));
5733 	zfs_dbgmsg_print(FTAG);
5734 
5735 	umem_free(tid, ztest_opts.zo_threads * sizeof (thread_t));
5736 
5737 	/* Kill the resume thread */
5738 	ztest_exiting = B_TRUE;
5739 	VERIFY(thr_join(resume_tid, NULL, NULL) == 0);
5740 	ztest_resume(spa);
5741 
5742 	/*
5743 	 * Right before closing the pool, kick off a bunch of async I/O;
5744 	 * spa_close() should wait for it to complete.
5745 	 */
5746 	for (uint64_t object = 1; object < 50; object++) {
5747 		dmu_prefetch(spa->spa_meta_objset, object, 0, 0, 1ULL << 20,
5748 		    ZIO_PRIORITY_SYNC_READ);
5749 	}
5750 
5751 	spa_close(spa, FTAG);
5752 
5753 	/*
5754 	 * Verify that we can loop over all pools.
5755 	 */
5756 	mutex_enter(&spa_namespace_lock);
5757 	for (spa = spa_next(NULL); spa != NULL; spa = spa_next(spa))
5758 		if (ztest_opts.zo_verbose > 3)
5759 			(void) printf("spa_next: found %s\n", spa_name(spa));
5760 	mutex_exit(&spa_namespace_lock);
5761 
5762 	/*
5763 	 * Verify that we can export the pool and reimport it under a
5764 	 * different name.
5765 	 */
5766 	if (ztest_random(2) == 0) {
5767 		char name[ZFS_MAX_DATASET_NAME_LEN];
5768 		(void) snprintf(name, sizeof (name), "%s_import",
5769 		    ztest_opts.zo_pool);
5770 		ztest_spa_import_export(ztest_opts.zo_pool, name);
5771 		ztest_spa_import_export(name, ztest_opts.zo_pool);
5772 	}
5773 
5774 	kernel_fini();
5775 
5776 	list_destroy(&zcl.zcl_callbacks);
5777 
5778 	(void) _mutex_destroy(&zcl.zcl_callbacks_lock);
5779 
5780 	(void) rwlock_destroy(&ztest_name_lock);
5781 	(void) _mutex_destroy(&ztest_vdev_lock);
5782 }
5783 
5784 static void
5785 ztest_freeze(void)
5786 {
5787 	ztest_ds_t *zd = &ztest_ds[0];
5788 	spa_t *spa;
5789 	int numloops = 0;
5790 
5791 	if (ztest_opts.zo_verbose >= 3)
5792 		(void) printf("testing spa_freeze()...\n");
5793 
5794 	kernel_init(FREAD | FWRITE);
5795 	VERIFY3U(0, ==, spa_open(ztest_opts.zo_pool, &spa, FTAG));
5796 	VERIFY3U(0, ==, ztest_dataset_open(0));
5797 	spa->spa_debug = B_TRUE;
5798 	ztest_spa = spa;
5799 
5800 	/*
5801 	 * Force the first log block to be transactionally allocated.
5802 	 * We have to do this before we freeze the pool -- otherwise
5803 	 * the log chain won't be anchored.
5804 	 */
5805 	while (BP_IS_HOLE(&zd->zd_zilog->zl_header->zh_log)) {
5806 		ztest_dmu_object_alloc_free(zd, 0);
5807 		zil_commit(zd->zd_zilog, 0);
5808 	}
5809 
5810 	txg_wait_synced(spa_get_dsl(spa), 0);
5811 
5812 	/*
5813 	 * Freeze the pool.  This stops spa_sync() from doing anything,
5814 	 * so that the only way to record changes from now on is the ZIL.
5815 	 */
5816 	spa_freeze(spa);
5817 
5818 	/*
5819 	 * Because it is hard to predict how much space a write will actually
5820 	 * require beforehand, we leave ourselves some fudge space to write over
5821 	 * capacity.
5822 	 */
5823 	uint64_t capacity = metaslab_class_get_space(spa_normal_class(spa)) / 2;
5824 
5825 	/*
5826 	 * Run tests that generate log records but don't alter the pool config
5827 	 * or depend on DSL sync tasks (snapshots, objset create/destroy, etc).
5828 	 * We do a txg_wait_synced() after each iteration to force the txg
5829 	 * to increase well beyond the last synced value in the uberblock.
5830 	 * The ZIL should be OK with that.
5831 	 *
5832 	 * Run a random number of times less than zo_maxloops and ensure we do
5833 	 * not run out of space on the pool.
5834 	 */
5835 	while (ztest_random(10) != 0 &&
5836 	    numloops++ < ztest_opts.zo_maxloops &&
5837 	    metaslab_class_get_alloc(spa_normal_class(spa)) < capacity) {
5838 		ztest_od_t od;
5839 		ztest_od_init(&od, 0, FTAG, 0, DMU_OT_UINT64_OTHER, 0, 0);
5840 		VERIFY0(ztest_object_init(zd, &od, sizeof (od), B_FALSE));
5841 		ztest_io(zd, od.od_object,
5842 		    ztest_random(ZTEST_RANGE_LOCKS) << SPA_MAXBLOCKSHIFT);
5843 		txg_wait_synced(spa_get_dsl(spa), 0);
5844 	}
5845 
5846 	/*
5847 	 * Commit all of the changes we just generated.
5848 	 */
5849 	zil_commit(zd->zd_zilog, 0);
5850 	txg_wait_synced(spa_get_dsl(spa), 0);
5851 
5852 	/*
5853 	 * Close our dataset and close the pool.
5854 	 */
5855 	ztest_dataset_close(0);
5856 	spa_close(spa, FTAG);
5857 	kernel_fini();
5858 
5859 	/*
5860 	 * Open and close the pool and dataset to induce log replay.
5861 	 */
5862 	kernel_init(FREAD | FWRITE);
5863 	VERIFY3U(0, ==, spa_open(ztest_opts.zo_pool, &spa, FTAG));
5864 	ASSERT(spa_freeze_txg(spa) == UINT64_MAX);
5865 	VERIFY3U(0, ==, ztest_dataset_open(0));
5866 	ztest_dataset_close(0);
5867 
5868 	spa->spa_debug = B_TRUE;
5869 	ztest_spa = spa;
5870 	txg_wait_synced(spa_get_dsl(spa), 0);
5871 	ztest_reguid(NULL, 0);
5872 
5873 	spa_close(spa, FTAG);
5874 	kernel_fini();
5875 }
5876 
5877 void
5878 print_time(hrtime_t t, char *timebuf)
5879 {
5880 	hrtime_t s = t / NANOSEC;
5881 	hrtime_t m = s / 60;
5882 	hrtime_t h = m / 60;
5883 	hrtime_t d = h / 24;
5884 
5885 	s -= m * 60;
5886 	m -= h * 60;
5887 	h -= d * 24;
5888 
5889 	timebuf[0] = '\0';
5890 
5891 	if (d)
5892 		(void) sprintf(timebuf,
5893 		    "%llud%02lluh%02llum%02llus", d, h, m, s);
5894 	else if (h)
5895 		(void) sprintf(timebuf, "%lluh%02llum%02llus", h, m, s);
5896 	else if (m)
5897 		(void) sprintf(timebuf, "%llum%02llus", m, s);
5898 	else
5899 		(void) sprintf(timebuf, "%llus", s);
5900 }
5901 
5902 static nvlist_t *
5903 make_random_props()
5904 {
5905 	nvlist_t *props;
5906 
5907 	VERIFY(nvlist_alloc(&props, NV_UNIQUE_NAME, 0) == 0);
5908 	if (ztest_random(2) == 0)
5909 		return (props);
5910 	VERIFY(nvlist_add_uint64(props, "autoreplace", 1) == 0);
5911 
5912 	return (props);
5913 }
5914 
5915 /*
5916  * Create a storage pool with the given name and initial vdev size.
5917  * Then test spa_freeze() functionality.
5918  */
5919 static void
5920 ztest_init(ztest_shared_t *zs)
5921 {
5922 	spa_t *spa;
5923 	nvlist_t *nvroot, *props;
5924 
5925 	VERIFY(_mutex_init(&ztest_vdev_lock, USYNC_THREAD, NULL) == 0);
5926 	VERIFY(rwlock_init(&ztest_name_lock, USYNC_THREAD, NULL) == 0);
5927 
5928 	kernel_init(FREAD | FWRITE);
5929 
5930 	/*
5931 	 * Create the storage pool.
5932 	 */
5933 	(void) spa_destroy(ztest_opts.zo_pool);
5934 	ztest_shared->zs_vdev_next_leaf = 0;
5935 	zs->zs_splits = 0;
5936 	zs->zs_mirrors = ztest_opts.zo_mirrors;
5937 	nvroot = make_vdev_root(NULL, NULL, NULL, ztest_opts.zo_vdev_size, 0,
5938 	    0, ztest_opts.zo_raidz, zs->zs_mirrors, 1);
5939 	props = make_random_props();
5940 	for (int i = 0; i < SPA_FEATURES; i++) {
5941 		char buf[1024];
5942 		(void) snprintf(buf, sizeof (buf), "feature@%s",
5943 		    spa_feature_table[i].fi_uname);
5944 		VERIFY3U(0, ==, nvlist_add_uint64(props, buf, 0));
5945 	}
5946 	VERIFY3U(0, ==, spa_create(ztest_opts.zo_pool, nvroot, props, NULL));
5947 	nvlist_free(nvroot);
5948 	nvlist_free(props);
5949 
5950 	VERIFY3U(0, ==, spa_open(ztest_opts.zo_pool, &spa, FTAG));
5951 	zs->zs_metaslab_sz =
5952 	    1ULL << spa->spa_root_vdev->vdev_child[0]->vdev_ms_shift;
5953 
5954 	spa_close(spa, FTAG);
5955 
5956 	kernel_fini();
5957 
5958 	ztest_run_zdb(ztest_opts.zo_pool);
5959 
5960 	ztest_freeze();
5961 
5962 	ztest_run_zdb(ztest_opts.zo_pool);
5963 
5964 	(void) rwlock_destroy(&ztest_name_lock);
5965 	(void) _mutex_destroy(&ztest_vdev_lock);
5966 }
5967 
5968 static void
5969 setup_data_fd(void)
5970 {
5971 	static char ztest_name_data[] = "/tmp/ztest.data.XXXXXX";
5972 
5973 	ztest_fd_data = mkstemp(ztest_name_data);
5974 	ASSERT3S(ztest_fd_data, >=, 0);
5975 	(void) unlink(ztest_name_data);
5976 }
5977 
5978 
5979 static int
5980 shared_data_size(ztest_shared_hdr_t *hdr)
5981 {
5982 	int size;
5983 
5984 	size = hdr->zh_hdr_size;
5985 	size += hdr->zh_opts_size;
5986 	size += hdr->zh_size;
5987 	size += hdr->zh_stats_size * hdr->zh_stats_count;
5988 	size += hdr->zh_ds_size * hdr->zh_ds_count;
5989 
5990 	return (size);
5991 }
5992 
5993 static void
5994 setup_hdr(void)
5995 {
5996 	int size;
5997 	ztest_shared_hdr_t *hdr;
5998 
5999 	hdr = (void *)mmap(0, P2ROUNDUP(sizeof (*hdr), getpagesize()),
6000 	    PROT_READ | PROT_WRITE, MAP_SHARED, ztest_fd_data, 0);
6001 	ASSERT(hdr != MAP_FAILED);
6002 
6003 	VERIFY3U(0, ==, ftruncate(ztest_fd_data, sizeof (ztest_shared_hdr_t)));
6004 
6005 	hdr->zh_hdr_size = sizeof (ztest_shared_hdr_t);
6006 	hdr->zh_opts_size = sizeof (ztest_shared_opts_t);
6007 	hdr->zh_size = sizeof (ztest_shared_t);
6008 	hdr->zh_stats_size = sizeof (ztest_shared_callstate_t);
6009 	hdr->zh_stats_count = ZTEST_FUNCS;
6010 	hdr->zh_ds_size = sizeof (ztest_shared_ds_t);
6011 	hdr->zh_ds_count = ztest_opts.zo_datasets;
6012 
6013 	size = shared_data_size(hdr);
6014 	VERIFY3U(0, ==, ftruncate(ztest_fd_data, size));
6015 
6016 	(void) munmap((caddr_t)hdr, P2ROUNDUP(sizeof (*hdr), getpagesize()));
6017 }
6018 
6019 static void
6020 setup_data(void)
6021 {
6022 	int size, offset;
6023 	ztest_shared_hdr_t *hdr;
6024 	uint8_t *buf;
6025 
6026 	hdr = (void *)mmap(0, P2ROUNDUP(sizeof (*hdr), getpagesize()),
6027 	    PROT_READ, MAP_SHARED, ztest_fd_data, 0);
6028 	ASSERT(hdr != MAP_FAILED);
6029 
6030 	size = shared_data_size(hdr);
6031 
6032 	(void) munmap((caddr_t)hdr, P2ROUNDUP(sizeof (*hdr), getpagesize()));
6033 	hdr = ztest_shared_hdr = (void *)mmap(0, P2ROUNDUP(size, getpagesize()),
6034 	    PROT_READ | PROT_WRITE, MAP_SHARED, ztest_fd_data, 0);
6035 	ASSERT(hdr != MAP_FAILED);
6036 	buf = (uint8_t *)hdr;
6037 
6038 	offset = hdr->zh_hdr_size;
6039 	ztest_shared_opts = (void *)&buf[offset];
6040 	offset += hdr->zh_opts_size;
6041 	ztest_shared = (void *)&buf[offset];
6042 	offset += hdr->zh_size;
6043 	ztest_shared_callstate = (void *)&buf[offset];
6044 	offset += hdr->zh_stats_size * hdr->zh_stats_count;
6045 	ztest_shared_ds = (void *)&buf[offset];
6046 }
6047 
6048 static boolean_t
6049 exec_child(char *cmd, char *libpath, boolean_t ignorekill, int *statusp)
6050 {
6051 	pid_t pid;
6052 	int status;
6053 	char *cmdbuf = NULL;
6054 
6055 	pid = fork();
6056 
6057 	if (cmd == NULL) {
6058 		cmdbuf = umem_alloc(MAXPATHLEN, UMEM_NOFAIL);
6059 		(void) strlcpy(cmdbuf, getexecname(), MAXPATHLEN);
6060 		cmd = cmdbuf;
6061 	}
6062 
6063 	if (pid == -1)
6064 		fatal(1, "fork failed");
6065 
6066 	if (pid == 0) {	/* child */
6067 		char *emptyargv[2] = { cmd, NULL };
6068 		char fd_data_str[12];
6069 
6070 		struct rlimit rl = { 1024, 1024 };
6071 		(void) setrlimit(RLIMIT_NOFILE, &rl);
6072 
6073 		(void) close(ztest_fd_rand);
6074 		VERIFY3U(11, >=,
6075 		    snprintf(fd_data_str, 12, "%d", ztest_fd_data));
6076 		VERIFY0(setenv("ZTEST_FD_DATA", fd_data_str, 1));
6077 
6078 		(void) enable_extended_FILE_stdio(-1, -1);
6079 		if (libpath != NULL)
6080 			VERIFY(0 == setenv("LD_LIBRARY_PATH", libpath, 1));
6081 		(void) execv(cmd, emptyargv);
6082 		ztest_dump_core = B_FALSE;
6083 		fatal(B_TRUE, "exec failed: %s", cmd);
6084 	}
6085 
6086 	if (cmdbuf != NULL) {
6087 		umem_free(cmdbuf, MAXPATHLEN);
6088 		cmd = NULL;
6089 	}
6090 
6091 	while (waitpid(pid, &status, 0) != pid)
6092 		continue;
6093 	if (statusp != NULL)
6094 		*statusp = status;
6095 
6096 	if (WIFEXITED(status)) {
6097 		if (WEXITSTATUS(status) != 0) {
6098 			(void) fprintf(stderr, "child exited with code %d\n",
6099 			    WEXITSTATUS(status));
6100 			exit(2);
6101 		}
6102 		return (B_FALSE);
6103 	} else if (WIFSIGNALED(status)) {
6104 		if (!ignorekill || WTERMSIG(status) != SIGKILL) {
6105 			(void) fprintf(stderr, "child died with signal %d\n",
6106 			    WTERMSIG(status));
6107 			exit(3);
6108 		}
6109 		return (B_TRUE);
6110 	} else {
6111 		(void) fprintf(stderr, "something strange happened to child\n");
6112 		exit(4);
6113 		/* NOTREACHED */
6114 	}
6115 }
6116 
6117 static void
6118 ztest_run_init(void)
6119 {
6120 	ztest_shared_t *zs = ztest_shared;
6121 
6122 	ASSERT(ztest_opts.zo_init != 0);
6123 
6124 	/*
6125 	 * Blow away any existing copy of zpool.cache
6126 	 */
6127 	(void) remove(spa_config_path);
6128 
6129 	/*
6130 	 * Create and initialize our storage pool.
6131 	 */
6132 	for (int i = 1; i <= ztest_opts.zo_init; i++) {
6133 		bzero(zs, sizeof (ztest_shared_t));
6134 		if (ztest_opts.zo_verbose >= 3 &&
6135 		    ztest_opts.zo_init != 1) {
6136 			(void) printf("ztest_init(), pass %d\n", i);
6137 		}
6138 		ztest_init(zs);
6139 	}
6140 }
6141 
6142 int
6143 main(int argc, char **argv)
6144 {
6145 	int kills = 0;
6146 	int iters = 0;
6147 	int older = 0;
6148 	int newer = 0;
6149 	ztest_shared_t *zs;
6150 	ztest_info_t *zi;
6151 	ztest_shared_callstate_t *zc;
6152 	char timebuf[100];
6153 	char numbuf[NN_NUMBUF_SZ];
6154 	spa_t *spa;
6155 	char *cmd;
6156 	boolean_t hasalt;
6157 	char *fd_data_str = getenv("ZTEST_FD_DATA");
6158 
6159 	(void) setvbuf(stdout, NULL, _IOLBF, 0);
6160 
6161 	dprintf_setup(&argc, argv);
6162 	zfs_deadman_synctime_ms = 300000;
6163 
6164 	ztest_fd_rand = open("/dev/urandom", O_RDONLY);
6165 	ASSERT3S(ztest_fd_rand, >=, 0);
6166 
6167 	if (!fd_data_str) {
6168 		process_options(argc, argv);
6169 
6170 		setup_data_fd();
6171 		setup_hdr();
6172 		setup_data();
6173 		bcopy(&ztest_opts, ztest_shared_opts,
6174 		    sizeof (*ztest_shared_opts));
6175 	} else {
6176 		ztest_fd_data = atoi(fd_data_str);
6177 		setup_data();
6178 		bcopy(ztest_shared_opts, &ztest_opts, sizeof (ztest_opts));
6179 	}
6180 	ASSERT3U(ztest_opts.zo_datasets, ==, ztest_shared_hdr->zh_ds_count);
6181 
6182 	/* Override location of zpool.cache */
6183 	VERIFY3U(asprintf((char **)&spa_config_path, "%s/zpool.cache",
6184 	    ztest_opts.zo_dir), !=, -1);
6185 
6186 	ztest_ds = umem_alloc(ztest_opts.zo_datasets * sizeof (ztest_ds_t),
6187 	    UMEM_NOFAIL);
6188 	zs = ztest_shared;
6189 
6190 	if (fd_data_str) {
6191 		metaslab_gang_bang = ztest_opts.zo_metaslab_gang_bang;
6192 		metaslab_df_alloc_threshold =
6193 		    zs->zs_metaslab_df_alloc_threshold;
6194 
6195 		if (zs->zs_do_init)
6196 			ztest_run_init();
6197 		else
6198 			ztest_run(zs);
6199 		exit(0);
6200 	}
6201 
6202 	hasalt = (strlen(ztest_opts.zo_alt_ztest) != 0);
6203 
6204 	if (ztest_opts.zo_verbose >= 1) {
6205 		(void) printf("%llu vdevs, %d datasets, %d threads,"
6206 		    " %llu seconds...\n",
6207 		    (u_longlong_t)ztest_opts.zo_vdevs,
6208 		    ztest_opts.zo_datasets,
6209 		    ztest_opts.zo_threads,
6210 		    (u_longlong_t)ztest_opts.zo_time);
6211 	}
6212 
6213 	cmd = umem_alloc(MAXNAMELEN, UMEM_NOFAIL);
6214 	(void) strlcpy(cmd, getexecname(), MAXNAMELEN);
6215 
6216 	zs->zs_do_init = B_TRUE;
6217 	if (strlen(ztest_opts.zo_alt_ztest) != 0) {
6218 		if (ztest_opts.zo_verbose >= 1) {
6219 			(void) printf("Executing older ztest for "
6220 			    "initialization: %s\n", ztest_opts.zo_alt_ztest);
6221 		}
6222 		VERIFY(!exec_child(ztest_opts.zo_alt_ztest,
6223 		    ztest_opts.zo_alt_libpath, B_FALSE, NULL));
6224 	} else {
6225 		VERIFY(!exec_child(NULL, NULL, B_FALSE, NULL));
6226 	}
6227 	zs->zs_do_init = B_FALSE;
6228 
6229 	zs->zs_proc_start = gethrtime();
6230 	zs->zs_proc_stop = zs->zs_proc_start + ztest_opts.zo_time * NANOSEC;
6231 
6232 	for (int f = 0; f < ZTEST_FUNCS; f++) {
6233 		zi = &ztest_info[f];
6234 		zc = ZTEST_GET_SHARED_CALLSTATE(f);
6235 		if (zs->zs_proc_start + zi->zi_interval[0] > zs->zs_proc_stop)
6236 			zc->zc_next = UINT64_MAX;
6237 		else
6238 			zc->zc_next = zs->zs_proc_start +
6239 			    ztest_random(2 * zi->zi_interval[0] + 1);
6240 	}
6241 
6242 	/*
6243 	 * Run the tests in a loop.  These tests include fault injection
6244 	 * to verify that self-healing data works, and forced crashes
6245 	 * to verify that we never lose on-disk consistency.
6246 	 */
6247 	while (gethrtime() < zs->zs_proc_stop) {
6248 		int status;
6249 		boolean_t killed;
6250 
6251 		/*
6252 		 * Initialize the workload counters for each function.
6253 		 */
6254 		for (int f = 0; f < ZTEST_FUNCS; f++) {
6255 			zc = ZTEST_GET_SHARED_CALLSTATE(f);
6256 			zc->zc_count = 0;
6257 			zc->zc_time = 0;
6258 		}
6259 
6260 		/* Set the allocation switch size */
6261 		zs->zs_metaslab_df_alloc_threshold =
6262 		    ztest_random(zs->zs_metaslab_sz / 4) + 1;
6263 
6264 		if (!hasalt || ztest_random(2) == 0) {
6265 			if (hasalt && ztest_opts.zo_verbose >= 1) {
6266 				(void) printf("Executing newer ztest: %s\n",
6267 				    cmd);
6268 			}
6269 			newer++;
6270 			killed = exec_child(cmd, NULL, B_TRUE, &status);
6271 		} else {
6272 			if (hasalt && ztest_opts.zo_verbose >= 1) {
6273 				(void) printf("Executing older ztest: %s\n",
6274 				    ztest_opts.zo_alt_ztest);
6275 			}
6276 			older++;
6277 			killed = exec_child(ztest_opts.zo_alt_ztest,
6278 			    ztest_opts.zo_alt_libpath, B_TRUE, &status);
6279 		}
6280 
6281 		if (killed)
6282 			kills++;
6283 		iters++;
6284 
6285 		if (ztest_opts.zo_verbose >= 1) {
6286 			hrtime_t now = gethrtime();
6287 
6288 			now = MIN(now, zs->zs_proc_stop);
6289 			print_time(zs->zs_proc_stop - now, timebuf);
6290 			nicenum(zs->zs_space, numbuf, sizeof (numbuf));
6291 
6292 			(void) printf("Pass %3d, %8s, %3llu ENOSPC, "
6293 			    "%4.1f%% of %5s used, %3.0f%% done, %8s to go\n",
6294 			    iters,
6295 			    WIFEXITED(status) ? "Complete" : "SIGKILL",
6296 			    (u_longlong_t)zs->zs_enospc_count,
6297 			    100.0 * zs->zs_alloc / zs->zs_space,
6298 			    numbuf,
6299 			    100.0 * (now - zs->zs_proc_start) /
6300 			    (ztest_opts.zo_time * NANOSEC), timebuf);
6301 		}
6302 
6303 		if (ztest_opts.zo_verbose >= 2) {
6304 			(void) printf("\nWorkload summary:\n\n");
6305 			(void) printf("%7s %9s   %s\n",
6306 			    "Calls", "Time", "Function");
6307 			(void) printf("%7s %9s   %s\n",
6308 			    "-----", "----", "--------");
6309 			for (int f = 0; f < ZTEST_FUNCS; f++) {
6310 				Dl_info dli;
6311 
6312 				zi = &ztest_info[f];
6313 				zc = ZTEST_GET_SHARED_CALLSTATE(f);
6314 				print_time(zc->zc_time, timebuf);
6315 				(void) dladdr((void *)zi->zi_func, &dli);
6316 				(void) printf("%7llu %9s   %s\n",
6317 				    (u_longlong_t)zc->zc_count, timebuf,
6318 				    dli.dli_sname);
6319 			}
6320 			(void) printf("\n");
6321 		}
6322 
6323 		/*
6324 		 * It's possible that we killed a child during a rename test,
6325 		 * in which case we'll have a 'ztest_tmp' pool lying around
6326 		 * instead of 'ztest'.  Do a blind rename in case this happened.
6327 		 */
6328 		kernel_init(FREAD);
6329 		if (spa_open(ztest_opts.zo_pool, &spa, FTAG) == 0) {
6330 			spa_close(spa, FTAG);
6331 		} else {
6332 			char tmpname[ZFS_MAX_DATASET_NAME_LEN];
6333 			kernel_fini();
6334 			kernel_init(FREAD | FWRITE);
6335 			(void) snprintf(tmpname, sizeof (tmpname), "%s_tmp",
6336 			    ztest_opts.zo_pool);
6337 			(void) spa_rename(tmpname, ztest_opts.zo_pool);
6338 		}
6339 		kernel_fini();
6340 
6341 		ztest_run_zdb(ztest_opts.zo_pool);
6342 	}
6343 
6344 	if (ztest_opts.zo_verbose >= 1) {
6345 		if (hasalt) {
6346 			(void) printf("%d runs of older ztest: %s\n", older,
6347 			    ztest_opts.zo_alt_ztest);
6348 			(void) printf("%d runs of newer ztest: %s\n", newer,
6349 			    cmd);
6350 		}
6351 		(void) printf("%d killed, %d completed, %.0f%% kill rate\n",
6352 		    kills, iters - kills, (100.0 * kills) / MAX(1, iters));
6353 	}
6354 
6355 	umem_free(cmd, MAXNAMELEN);
6356 
6357 	return (0);
6358 }
6359