xref: /titanic_50/usr/src/cmd/mdb/common/modules/zfs/zfs.c (revision a80670315ce377f65d0b82e01c8c0538cd176f39)
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 2011 Nexenta Systems, Inc. All rights reserved.
24  */
25 
26 /* Portions Copyright 2010 Robert Milkowski */
27 
28 #include <mdb/mdb_ctf.h>
29 #include <sys/zfs_context.h>
30 #include <sys/mdb_modapi.h>
31 #include <sys/dbuf.h>
32 #include <sys/dmu_objset.h>
33 #include <sys/dsl_dir.h>
34 #include <sys/dsl_pool.h>
35 #include <sys/metaslab_impl.h>
36 #include <sys/space_map.h>
37 #include <sys/list.h>
38 #include <sys/spa_impl.h>
39 #include <sys/vdev_impl.h>
40 #include <sys/zap_leaf.h>
41 #include <sys/zap_impl.h>
42 #include <ctype.h>
43 #include <sys/zfs_acl.h>
44 #include <sys/sa_impl.h>
45 
46 #ifdef _KERNEL
47 #define	ZFS_OBJ_NAME	"zfs"
48 #else
49 #define	ZFS_OBJ_NAME	"libzpool.so.1"
50 #endif
51 
52 #ifndef _KERNEL
53 int aok;
54 #endif
55 
56 static int
57 getmember(uintptr_t addr, const char *type, mdb_ctf_id_t *idp,
58     const char *member, int len, void *buf)
59 {
60 	mdb_ctf_id_t id;
61 	ulong_t off;
62 	char name[64];
63 
64 	if (idp == NULL) {
65 		if (mdb_ctf_lookup_by_name(type, &id) == -1) {
66 			mdb_warn("couldn't find type %s", type);
67 			return (DCMD_ERR);
68 		}
69 		idp = &id;
70 	} else {
71 		type = name;
72 		mdb_ctf_type_name(*idp, name, sizeof (name));
73 	}
74 
75 	if (mdb_ctf_offsetof(*idp, member, &off) == -1) {
76 		mdb_warn("couldn't find member %s of type %s\n", member, type);
77 		return (DCMD_ERR);
78 	}
79 	if (off % 8 != 0) {
80 		mdb_warn("member %s of type %s is unsupported bitfield",
81 		    member, type);
82 		return (DCMD_ERR);
83 	}
84 	off /= 8;
85 
86 	if (mdb_vread(buf, len, addr + off) == -1) {
87 		mdb_warn("failed to read %s from %s at %p",
88 		    member, type, addr + off);
89 		return (DCMD_ERR);
90 	}
91 	/* mdb_warn("read %s from %s at %p+%llx\n", member, type, addr, off); */
92 
93 	return (0);
94 }
95 
96 #define	GETMEMB(addr, type, member, dest) \
97 	getmember(addr, #type, NULL, #member, sizeof (dest), &(dest))
98 
99 #define	GETMEMBID(addr, ctfid, member, dest) \
100 	getmember(addr, NULL, ctfid, #member, sizeof (dest), &(dest))
101 
102 static int
103 getrefcount(uintptr_t addr, mdb_ctf_id_t *id,
104     const char *member, uint64_t *rc)
105 {
106 	static int gotid;
107 	static mdb_ctf_id_t rc_id;
108 	ulong_t off;
109 
110 	if (!gotid) {
111 		if (mdb_ctf_lookup_by_name("struct refcount", &rc_id) == -1) {
112 			mdb_warn("couldn't find struct refcount");
113 			return (DCMD_ERR);
114 		}
115 		gotid = TRUE;
116 	}
117 
118 	if (mdb_ctf_offsetof(*id, member, &off) == -1) {
119 		char name[64];
120 		mdb_ctf_type_name(*id, name, sizeof (name));
121 		mdb_warn("couldn't find member %s of type %s\n", member, name);
122 		return (DCMD_ERR);
123 	}
124 	off /= 8;
125 
126 	return (GETMEMBID(addr + off, &rc_id, rc_count, *rc));
127 }
128 
129 static boolean_t
130 strisprint(const char *cp)
131 {
132 	for (; *cp; cp++) {
133 		if (!isprint(*cp))
134 			return (B_FALSE);
135 	}
136 	return (B_TRUE);
137 }
138 
139 static int verbose;
140 
141 static int
142 freelist_walk_init(mdb_walk_state_t *wsp)
143 {
144 	if (wsp->walk_addr == NULL) {
145 		mdb_warn("must supply starting address\n");
146 		return (WALK_ERR);
147 	}
148 
149 	wsp->walk_data = 0;  /* Index into the freelist */
150 	return (WALK_NEXT);
151 }
152 
153 static int
154 freelist_walk_step(mdb_walk_state_t *wsp)
155 {
156 	uint64_t entry;
157 	uintptr_t number = (uintptr_t)wsp->walk_data;
158 	char *ddata[] = { "ALLOC", "FREE", "CONDENSE", "INVALID",
159 			    "INVALID", "INVALID", "INVALID", "INVALID" };
160 	int mapshift = SPA_MINBLOCKSHIFT;
161 
162 	if (mdb_vread(&entry, sizeof (entry), wsp->walk_addr) == -1) {
163 		mdb_warn("failed to read freelist entry %p", wsp->walk_addr);
164 		return (WALK_DONE);
165 	}
166 	wsp->walk_addr += sizeof (entry);
167 	wsp->walk_data = (void *)(number + 1);
168 
169 	if (SM_DEBUG_DECODE(entry)) {
170 		mdb_printf("DEBUG: %3u  %10s: txg=%llu  pass=%llu\n",
171 		    number,
172 		    ddata[SM_DEBUG_ACTION_DECODE(entry)],
173 		    SM_DEBUG_TXG_DECODE(entry),
174 		    SM_DEBUG_SYNCPASS_DECODE(entry));
175 	} else {
176 		mdb_printf("Entry: %3u  offsets=%08llx-%08llx  type=%c  "
177 		    "size=%06llx", number,
178 		    SM_OFFSET_DECODE(entry) << mapshift,
179 		    (SM_OFFSET_DECODE(entry) + SM_RUN_DECODE(entry)) <<
180 		    mapshift,
181 		    SM_TYPE_DECODE(entry) == SM_ALLOC ? 'A' : 'F',
182 		    SM_RUN_DECODE(entry) << mapshift);
183 		if (verbose)
184 			mdb_printf("      (raw=%012llx)\n", entry);
185 		mdb_printf("\n");
186 	}
187 	return (WALK_NEXT);
188 }
189 
190 
191 static int
192 dataset_name(uintptr_t addr, char *buf)
193 {
194 	static int gotid;
195 	static mdb_ctf_id_t dd_id;
196 	uintptr_t dd_parent;
197 	char dd_myname[MAXNAMELEN];
198 
199 	if (!gotid) {
200 		if (mdb_ctf_lookup_by_name("struct dsl_dir",
201 		    &dd_id) == -1) {
202 			mdb_warn("couldn't find struct dsl_dir");
203 			return (DCMD_ERR);
204 		}
205 		gotid = TRUE;
206 	}
207 	if (GETMEMBID(addr, &dd_id, dd_parent, dd_parent) ||
208 	    GETMEMBID(addr, &dd_id, dd_myname, dd_myname)) {
209 		return (DCMD_ERR);
210 	}
211 
212 	if (dd_parent) {
213 		if (dataset_name(dd_parent, buf))
214 			return (DCMD_ERR);
215 		strcat(buf, "/");
216 	}
217 
218 	if (dd_myname[0])
219 		strcat(buf, dd_myname);
220 	else
221 		strcat(buf, "???");
222 
223 	return (0);
224 }
225 
226 static int
227 objset_name(uintptr_t addr, char *buf)
228 {
229 	static int gotid;
230 	static mdb_ctf_id_t os_id, ds_id;
231 	uintptr_t os_dsl_dataset;
232 	char ds_snapname[MAXNAMELEN];
233 	uintptr_t ds_dir;
234 
235 	buf[0] = '\0';
236 
237 	if (!gotid) {
238 		if (mdb_ctf_lookup_by_name("struct objset",
239 		    &os_id) == -1) {
240 			mdb_warn("couldn't find struct objset");
241 			return (DCMD_ERR);
242 		}
243 		if (mdb_ctf_lookup_by_name("struct dsl_dataset",
244 		    &ds_id) == -1) {
245 			mdb_warn("couldn't find struct dsl_dataset");
246 			return (DCMD_ERR);
247 		}
248 
249 		gotid = TRUE;
250 	}
251 
252 	if (GETMEMBID(addr, &os_id, os_dsl_dataset, os_dsl_dataset))
253 		return (DCMD_ERR);
254 
255 	if (os_dsl_dataset == 0) {
256 		strcat(buf, "mos");
257 		return (0);
258 	}
259 
260 	if (GETMEMBID(os_dsl_dataset, &ds_id, ds_snapname, ds_snapname) ||
261 	    GETMEMBID(os_dsl_dataset, &ds_id, ds_dir, ds_dir)) {
262 		return (DCMD_ERR);
263 	}
264 
265 	if (ds_dir && dataset_name(ds_dir, buf))
266 		return (DCMD_ERR);
267 
268 	if (ds_snapname[0]) {
269 		strcat(buf, "@");
270 		strcat(buf, ds_snapname);
271 	}
272 	return (0);
273 }
274 
275 static void
276 enum_lookup(char *out, size_t size, mdb_ctf_id_t id, int val,
277     const char *prefix)
278 {
279 	const char *cp;
280 	size_t len = strlen(prefix);
281 
282 	if ((cp = mdb_ctf_enum_name(id, val)) != NULL) {
283 		if (strncmp(cp, prefix, len) == 0)
284 			cp += len;
285 		(void) strncpy(out, cp, size);
286 	} else {
287 		mdb_snprintf(out, size, "? (%d)", val);
288 	}
289 }
290 
291 /* ARGSUSED */
292 static int
293 zfs_params(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
294 {
295 	/*
296 	 * This table can be approximately generated by running:
297 	 * egrep "^[a-z0-9_]+ [a-z0-9_]+( =.*)?;" *.c | cut -d ' ' -f 2
298 	 */
299 	static const char *params[] = {
300 		"arc_reduce_dnlc_percent",
301 		"zfs_arc_max",
302 		"zfs_arc_min",
303 		"arc_shrink_shift",
304 		"zfs_mdcomp_disable",
305 		"zfs_prefetch_disable",
306 		"zfetch_max_streams",
307 		"zfetch_min_sec_reap",
308 		"zfetch_block_cap",
309 		"zfetch_array_rd_sz",
310 		"zfs_default_bs",
311 		"zfs_default_ibs",
312 		"metaslab_aliquot",
313 		"reference_tracking_enable",
314 		"reference_history",
315 		"spa_max_replication_override",
316 		"spa_mode_global",
317 		"zfs_flags",
318 		"zfs_txg_synctime_ms",
319 		"zfs_txg_timeout",
320 		"zfs_write_limit_min",
321 		"zfs_write_limit_max",
322 		"zfs_write_limit_shift",
323 		"zfs_write_limit_override",
324 		"zfs_no_write_throttle",
325 		"zfs_vdev_cache_max",
326 		"zfs_vdev_cache_size",
327 		"zfs_vdev_cache_bshift",
328 		"vdev_mirror_shift",
329 		"zfs_vdev_max_pending",
330 		"zfs_vdev_min_pending",
331 		"zfs_scrub_limit",
332 		"zfs_no_scrub_io",
333 		"zfs_no_scrub_prefetch",
334 		"zfs_vdev_time_shift",
335 		"zfs_vdev_ramp_rate",
336 		"zfs_vdev_aggregation_limit",
337 		"fzap_default_block_shift",
338 		"zfs_immediate_write_sz",
339 		"zfs_read_chunk_size",
340 		"zfs_nocacheflush",
341 		"zil_replay_disable",
342 		"metaslab_gang_bang",
343 		"metaslab_df_alloc_threshold",
344 		"metaslab_df_free_pct",
345 		"zio_injection_enabled",
346 		"zvol_immediate_write_sz",
347 	};
348 
349 	for (int i = 0; i < sizeof (params) / sizeof (params[0]); i++) {
350 		int sz;
351 		uint64_t val64;
352 		uint32_t *val32p = (uint32_t *)&val64;
353 
354 		sz = mdb_readvar(&val64, params[i]);
355 		if (sz == 4) {
356 			mdb_printf("%s = 0x%x\n", params[i], *val32p);
357 		} else if (sz == 8) {
358 			mdb_printf("%s = 0x%llx\n", params[i], val64);
359 		} else {
360 			mdb_warn("variable %s not found", params[i]);
361 		}
362 	}
363 
364 	return (DCMD_OK);
365 }
366 
367 /* ARGSUSED */
368 static int
369 blkptr(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
370 {
371 	mdb_ctf_id_t type_enum, checksum_enum, compress_enum;
372 	char type[80], checksum[80], compress[80];
373 	blkptr_t blk, *bp = &blk;
374 	char buf[BP_SPRINTF_LEN];
375 
376 	if (mdb_vread(&blk, sizeof (blkptr_t), addr) == -1) {
377 		mdb_warn("failed to read blkptr_t");
378 		return (DCMD_ERR);
379 	}
380 
381 	if (mdb_ctf_lookup_by_name("enum dmu_object_type", &type_enum) == -1 ||
382 	    mdb_ctf_lookup_by_name("enum zio_checksum", &checksum_enum) == -1 ||
383 	    mdb_ctf_lookup_by_name("enum zio_compress", &compress_enum) == -1) {
384 		mdb_warn("Could not find blkptr enumerated types");
385 		return (DCMD_ERR);
386 	}
387 
388 	enum_lookup(type, sizeof (type), type_enum,
389 	    BP_GET_TYPE(bp), "DMU_OT_");
390 	enum_lookup(checksum, sizeof (checksum), checksum_enum,
391 	    BP_GET_CHECKSUM(bp), "ZIO_CHECKSUM_");
392 	enum_lookup(compress, sizeof (compress), compress_enum,
393 	    BP_GET_COMPRESS(bp), "ZIO_COMPRESS_");
394 
395 	SPRINTF_BLKPTR(mdb_snprintf, '\n', buf, bp, type, checksum, compress);
396 
397 	mdb_printf("%s\n", buf);
398 
399 	return (DCMD_OK);
400 }
401 
402 /* ARGSUSED */
403 static int
404 dbuf(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
405 {
406 	mdb_ctf_id_t id;
407 	dmu_buf_t db;
408 	uintptr_t objset;
409 	uint8_t level;
410 	uint64_t blkid;
411 	uint64_t holds;
412 	char objectname[32];
413 	char blkidname[32];
414 	char path[MAXNAMELEN];
415 
416 	if (DCMD_HDRSPEC(flags)) {
417 		mdb_printf("        addr object lvl blkid holds os\n");
418 	}
419 
420 	if (mdb_ctf_lookup_by_name("struct dmu_buf_impl", &id) == -1) {
421 		mdb_warn("couldn't find struct dmu_buf_impl_t");
422 		return (DCMD_ERR);
423 	}
424 
425 	if (GETMEMBID(addr, &id, db_objset, objset) ||
426 	    GETMEMBID(addr, &id, db, db) ||
427 	    GETMEMBID(addr, &id, db_level, level) ||
428 	    GETMEMBID(addr, &id, db_blkid, blkid)) {
429 		return (WALK_ERR);
430 	}
431 
432 	if (getrefcount(addr, &id, "db_holds", &holds)) {
433 		return (WALK_ERR);
434 	}
435 
436 	if (db.db_object == DMU_META_DNODE_OBJECT)
437 		(void) strcpy(objectname, "mdn");
438 	else
439 		(void) mdb_snprintf(objectname, sizeof (objectname), "%llx",
440 		    (u_longlong_t)db.db_object);
441 
442 	if (blkid == DMU_BONUS_BLKID)
443 		(void) strcpy(blkidname, "bonus");
444 	else
445 		(void) mdb_snprintf(blkidname, sizeof (blkidname), "%llx",
446 		    (u_longlong_t)blkid);
447 
448 	if (objset_name(objset, path)) {
449 		return (WALK_ERR);
450 	}
451 
452 	mdb_printf("%p %8s %1u %9s %2llu %s\n",
453 	    addr, objectname, level, blkidname, holds, path);
454 
455 	return (DCMD_OK);
456 }
457 
458 /* ARGSUSED */
459 static int
460 dbuf_stats(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
461 {
462 #define	HISTOSZ 32
463 	uintptr_t dbp;
464 	dmu_buf_impl_t db;
465 	dbuf_hash_table_t ht;
466 	uint64_t bucket, ndbufs;
467 	uint64_t histo[HISTOSZ];
468 	uint64_t histo2[HISTOSZ];
469 	int i, maxidx;
470 
471 	if (mdb_readvar(&ht, "dbuf_hash_table") == -1) {
472 		mdb_warn("failed to read 'dbuf_hash_table'");
473 		return (DCMD_ERR);
474 	}
475 
476 	for (i = 0; i < HISTOSZ; i++) {
477 		histo[i] = 0;
478 		histo2[i] = 0;
479 	}
480 
481 	ndbufs = 0;
482 	for (bucket = 0; bucket < ht.hash_table_mask+1; bucket++) {
483 		int len;
484 
485 		if (mdb_vread(&dbp, sizeof (void *),
486 		    (uintptr_t)(ht.hash_table+bucket)) == -1) {
487 			mdb_warn("failed to read hash bucket %u at %p",
488 			    bucket, ht.hash_table+bucket);
489 			return (DCMD_ERR);
490 		}
491 
492 		len = 0;
493 		while (dbp != 0) {
494 			if (mdb_vread(&db, sizeof (dmu_buf_impl_t),
495 			    dbp) == -1) {
496 				mdb_warn("failed to read dbuf at %p", dbp);
497 				return (DCMD_ERR);
498 			}
499 			dbp = (uintptr_t)db.db_hash_next;
500 			for (i = MIN(len, HISTOSZ - 1); i >= 0; i--)
501 				histo2[i]++;
502 			len++;
503 			ndbufs++;
504 		}
505 
506 		if (len >= HISTOSZ)
507 			len = HISTOSZ-1;
508 		histo[len]++;
509 	}
510 
511 	mdb_printf("hash table has %llu buckets, %llu dbufs "
512 	    "(avg %llu buckets/dbuf)\n",
513 	    ht.hash_table_mask+1, ndbufs,
514 	    (ht.hash_table_mask+1)/ndbufs);
515 
516 	mdb_printf("\n");
517 	maxidx = 0;
518 	for (i = 0; i < HISTOSZ; i++)
519 		if (histo[i] > 0)
520 			maxidx = i;
521 	mdb_printf("hash chain length	number of buckets\n");
522 	for (i = 0; i <= maxidx; i++)
523 		mdb_printf("%u			%llu\n", i, histo[i]);
524 
525 	mdb_printf("\n");
526 	maxidx = 0;
527 	for (i = 0; i < HISTOSZ; i++)
528 		if (histo2[i] > 0)
529 			maxidx = i;
530 	mdb_printf("hash chain depth	number of dbufs\n");
531 	for (i = 0; i <= maxidx; i++)
532 		mdb_printf("%u or more		%llu	%llu%%\n",
533 		    i, histo2[i], histo2[i]*100/ndbufs);
534 
535 
536 	return (DCMD_OK);
537 }
538 
539 #define	CHAIN_END 0xffff
540 /*
541  * ::zap_leaf [-v]
542  *
543  * Print a zap_leaf_phys_t, assumed to be 16k
544  */
545 /* ARGSUSED */
546 static int
547 zap_leaf(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
548 {
549 	char buf[16*1024];
550 	int verbose = B_FALSE;
551 	int four = B_FALSE;
552 	zap_leaf_t l;
553 	zap_leaf_phys_t *zlp = (void *)buf;
554 	int i;
555 
556 	if (mdb_getopts(argc, argv,
557 	    'v', MDB_OPT_SETBITS, TRUE, &verbose,
558 	    '4', MDB_OPT_SETBITS, TRUE, &four,
559 	    NULL) != argc)
560 		return (DCMD_USAGE);
561 
562 	l.l_phys = zlp;
563 	l.l_bs = 14; /* assume 16k blocks */
564 	if (four)
565 		l.l_bs = 12;
566 
567 	if (!(flags & DCMD_ADDRSPEC)) {
568 		return (DCMD_USAGE);
569 	}
570 
571 	if (mdb_vread(buf, sizeof (buf), addr) == -1) {
572 		mdb_warn("failed to read zap_leaf_phys_t at %p", addr);
573 		return (DCMD_ERR);
574 	}
575 
576 	if (zlp->l_hdr.lh_block_type != ZBT_LEAF ||
577 	    zlp->l_hdr.lh_magic != ZAP_LEAF_MAGIC) {
578 		mdb_warn("This does not appear to be a zap_leaf_phys_t");
579 		return (DCMD_ERR);
580 	}
581 
582 	mdb_printf("zap_leaf_phys_t at %p:\n", addr);
583 	mdb_printf("    lh_prefix_len = %u\n", zlp->l_hdr.lh_prefix_len);
584 	mdb_printf("    lh_prefix = %llx\n", zlp->l_hdr.lh_prefix);
585 	mdb_printf("    lh_nentries = %u\n", zlp->l_hdr.lh_nentries);
586 	mdb_printf("    lh_nfree = %u\n", zlp->l_hdr.lh_nfree,
587 	    zlp->l_hdr.lh_nfree * 100 / (ZAP_LEAF_NUMCHUNKS(&l)));
588 	mdb_printf("    lh_freelist = %u\n", zlp->l_hdr.lh_freelist);
589 	mdb_printf("    lh_flags = %x (%s)\n", zlp->l_hdr.lh_flags,
590 	    zlp->l_hdr.lh_flags & ZLF_ENTRIES_CDSORTED ?
591 	    "ENTRIES_CDSORTED" : "");
592 
593 	if (verbose) {
594 		mdb_printf(" hash table:\n");
595 		for (i = 0; i < ZAP_LEAF_HASH_NUMENTRIES(&l); i++) {
596 			if (zlp->l_hash[i] != CHAIN_END)
597 				mdb_printf("    %u: %u\n", i, zlp->l_hash[i]);
598 		}
599 	}
600 
601 	mdb_printf(" chunks:\n");
602 	for (i = 0; i < ZAP_LEAF_NUMCHUNKS(&l); i++) {
603 		/* LINTED: alignment */
604 		zap_leaf_chunk_t *zlc = &ZAP_LEAF_CHUNK(&l, i);
605 		switch (zlc->l_entry.le_type) {
606 		case ZAP_CHUNK_FREE:
607 			if (verbose) {
608 				mdb_printf("    %u: free; lf_next = %u\n",
609 				    i, zlc->l_free.lf_next);
610 			}
611 			break;
612 		case ZAP_CHUNK_ENTRY:
613 			mdb_printf("    %u: entry\n", i);
614 			if (verbose) {
615 				mdb_printf("        le_next = %u\n",
616 				    zlc->l_entry.le_next);
617 			}
618 			mdb_printf("        le_name_chunk = %u\n",
619 			    zlc->l_entry.le_name_chunk);
620 			mdb_printf("        le_name_numints = %u\n",
621 			    zlc->l_entry.le_name_numints);
622 			mdb_printf("        le_value_chunk = %u\n",
623 			    zlc->l_entry.le_value_chunk);
624 			mdb_printf("        le_value_intlen = %u\n",
625 			    zlc->l_entry.le_value_intlen);
626 			mdb_printf("        le_value_numints = %u\n",
627 			    zlc->l_entry.le_value_numints);
628 			mdb_printf("        le_cd = %u\n",
629 			    zlc->l_entry.le_cd);
630 			mdb_printf("        le_hash = %llx\n",
631 			    zlc->l_entry.le_hash);
632 			break;
633 		case ZAP_CHUNK_ARRAY:
634 			mdb_printf("    %u: array", i);
635 			if (strisprint((char *)zlc->l_array.la_array))
636 				mdb_printf(" \"%s\"", zlc->l_array.la_array);
637 			mdb_printf("\n");
638 			if (verbose) {
639 				int j;
640 				mdb_printf("        ");
641 				for (j = 0; j < ZAP_LEAF_ARRAY_BYTES; j++) {
642 					mdb_printf("%02x ",
643 					    zlc->l_array.la_array[j]);
644 				}
645 				mdb_printf("\n");
646 			}
647 			if (zlc->l_array.la_next != CHAIN_END) {
648 				mdb_printf("        lf_next = %u\n",
649 				    zlc->l_array.la_next);
650 			}
651 			break;
652 		default:
653 			mdb_printf("    %u: undefined type %u\n",
654 			    zlc->l_entry.le_type);
655 		}
656 	}
657 
658 	return (DCMD_OK);
659 }
660 
661 typedef struct dbufs_data {
662 	mdb_ctf_id_t id;
663 	uint64_t objset;
664 	uint64_t object;
665 	uint64_t level;
666 	uint64_t blkid;
667 	char *osname;
668 } dbufs_data_t;
669 
670 #define	DBUFS_UNSET	(0xbaddcafedeadbeefULL)
671 
672 /* ARGSUSED */
673 static int
674 dbufs_cb(uintptr_t addr, const void *unknown, void *arg)
675 {
676 	dbufs_data_t *data = arg;
677 	uintptr_t objset;
678 	dmu_buf_t db;
679 	uint8_t level;
680 	uint64_t blkid;
681 	char osname[MAXNAMELEN];
682 
683 	if (GETMEMBID(addr, &data->id, db_objset, objset) ||
684 	    GETMEMBID(addr, &data->id, db, db) ||
685 	    GETMEMBID(addr, &data->id, db_level, level) ||
686 	    GETMEMBID(addr, &data->id, db_blkid, blkid)) {
687 		return (WALK_ERR);
688 	}
689 
690 	if ((data->objset == DBUFS_UNSET || data->objset == objset) &&
691 	    (data->osname == NULL || (objset_name(objset, osname) == 0 &&
692 	    strcmp(data->osname, osname) == 0)) &&
693 	    (data->object == DBUFS_UNSET || data->object == db.db_object) &&
694 	    (data->level == DBUFS_UNSET || data->level == level) &&
695 	    (data->blkid == DBUFS_UNSET || data->blkid == blkid)) {
696 		mdb_printf("%#lr\n", addr);
697 	}
698 	return (WALK_NEXT);
699 }
700 
701 /* ARGSUSED */
702 static int
703 dbufs(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
704 {
705 	dbufs_data_t data;
706 	char *object = NULL;
707 	char *blkid = NULL;
708 
709 	data.objset = data.object = data.level = data.blkid = DBUFS_UNSET;
710 	data.osname = NULL;
711 
712 	if (mdb_getopts(argc, argv,
713 	    'O', MDB_OPT_UINT64, &data.objset,
714 	    'n', MDB_OPT_STR, &data.osname,
715 	    'o', MDB_OPT_STR, &object,
716 	    'l', MDB_OPT_UINT64, &data.level,
717 	    'b', MDB_OPT_STR, &blkid) != argc) {
718 		return (DCMD_USAGE);
719 	}
720 
721 	if (object) {
722 		if (strcmp(object, "mdn") == 0) {
723 			data.object = DMU_META_DNODE_OBJECT;
724 		} else {
725 			data.object = mdb_strtoull(object);
726 		}
727 	}
728 
729 	if (blkid) {
730 		if (strcmp(blkid, "bonus") == 0) {
731 			data.blkid = DMU_BONUS_BLKID;
732 		} else {
733 			data.blkid = mdb_strtoull(blkid);
734 		}
735 	}
736 
737 	if (mdb_ctf_lookup_by_name("struct dmu_buf_impl", &data.id) == -1) {
738 		mdb_warn("couldn't find struct dmu_buf_impl_t");
739 		return (DCMD_ERR);
740 	}
741 
742 	if (mdb_walk("dmu_buf_impl_t", dbufs_cb, &data) != 0) {
743 		mdb_warn("can't walk dbufs");
744 		return (DCMD_ERR);
745 	}
746 
747 	return (DCMD_OK);
748 }
749 
750 typedef struct abuf_find_data {
751 	dva_t dva;
752 	mdb_ctf_id_t id;
753 } abuf_find_data_t;
754 
755 /* ARGSUSED */
756 static int
757 abuf_find_cb(uintptr_t addr, const void *unknown, void *arg)
758 {
759 	abuf_find_data_t *data = arg;
760 	dva_t dva;
761 
762 	if (GETMEMBID(addr, &data->id, b_dva, dva)) {
763 		return (WALK_ERR);
764 	}
765 
766 	if (dva.dva_word[0] == data->dva.dva_word[0] &&
767 	    dva.dva_word[1] == data->dva.dva_word[1]) {
768 		mdb_printf("%#lr\n", addr);
769 	}
770 	return (WALK_NEXT);
771 }
772 
773 /* ARGSUSED */
774 static int
775 abuf_find(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
776 {
777 	abuf_find_data_t data;
778 	GElf_Sym sym;
779 	int i;
780 	const char *syms[] = {
781 		"ARC_mru",
782 		"ARC_mru_ghost",
783 		"ARC_mfu",
784 		"ARC_mfu_ghost",
785 	};
786 
787 	if (argc != 2)
788 		return (DCMD_USAGE);
789 
790 	for (i = 0; i < 2; i ++) {
791 		switch (argv[i].a_type) {
792 		case MDB_TYPE_STRING:
793 			data.dva.dva_word[i] = mdb_strtoull(argv[i].a_un.a_str);
794 			break;
795 		case MDB_TYPE_IMMEDIATE:
796 			data.dva.dva_word[i] = argv[i].a_un.a_val;
797 			break;
798 		default:
799 			return (DCMD_USAGE);
800 		}
801 	}
802 
803 	if (mdb_ctf_lookup_by_name("struct arc_buf_hdr", &data.id) == -1) {
804 		mdb_warn("couldn't find struct arc_buf_hdr");
805 		return (DCMD_ERR);
806 	}
807 
808 	for (i = 0; i < sizeof (syms) / sizeof (syms[0]); i++) {
809 		if (mdb_lookup_by_name(syms[i], &sym)) {
810 			mdb_warn("can't find symbol %s", syms[i]);
811 			return (DCMD_ERR);
812 		}
813 
814 		if (mdb_pwalk("list", abuf_find_cb, &data, sym.st_value) != 0) {
815 			mdb_warn("can't walk %s", syms[i]);
816 			return (DCMD_ERR);
817 		}
818 	}
819 
820 	return (DCMD_OK);
821 }
822 
823 /* ARGSUSED */
824 static int
825 dbgmsg_cb(uintptr_t addr, const void *unknown, void *arg)
826 {
827 	static mdb_ctf_id_t id;
828 	static boolean_t gotid;
829 	static ulong_t off;
830 
831 	int *verbosep = arg;
832 	time_t timestamp;
833 	char buf[1024];
834 
835 	if (!gotid) {
836 		if (mdb_ctf_lookup_by_name("struct zfs_dbgmsg", &id) == -1) {
837 			mdb_warn("couldn't find struct zfs_dbgmsg");
838 			return (WALK_ERR);
839 		}
840 		gotid = TRUE;
841 		if (mdb_ctf_offsetof(id, "zdm_msg", &off) == -1) {
842 			mdb_warn("couldn't find zdm_msg");
843 			return (WALK_ERR);
844 		}
845 		off /= 8;
846 	}
847 
848 
849 	if (GETMEMBID(addr, &id, zdm_timestamp, timestamp)) {
850 		return (WALK_ERR);
851 	}
852 
853 	if (mdb_readstr(buf, sizeof (buf), addr + off) == -1) {
854 		mdb_warn("failed to read zdm_msg at %p\n", addr + off);
855 		return (DCMD_ERR);
856 	}
857 
858 	if (*verbosep)
859 		mdb_printf("%Y ", timestamp);
860 
861 	mdb_printf("%s\n", buf);
862 
863 	if (*verbosep)
864 		(void) mdb_call_dcmd("whatis", addr, DCMD_ADDRSPEC, 0, NULL);
865 
866 	return (WALK_NEXT);
867 }
868 
869 /* ARGSUSED */
870 static int
871 dbgmsg(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
872 {
873 	GElf_Sym sym;
874 	int verbose = FALSE;
875 
876 	if (mdb_getopts(argc, argv,
877 	    'v', MDB_OPT_SETBITS, TRUE, &verbose,
878 	    NULL) != argc)
879 		return (DCMD_USAGE);
880 
881 	if (mdb_lookup_by_name("zfs_dbgmsgs", &sym)) {
882 		mdb_warn("can't find zfs_dbgmsgs");
883 		return (DCMD_ERR);
884 	}
885 
886 	if (mdb_pwalk("list", dbgmsg_cb, &verbose, sym.st_value) != 0) {
887 		mdb_warn("can't walk zfs_dbgmsgs");
888 		return (DCMD_ERR);
889 	}
890 
891 	return (DCMD_OK);
892 }
893 
894 /*ARGSUSED*/
895 static int
896 arc_print(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
897 {
898 	kstat_named_t *stats;
899 	GElf_Sym sym;
900 	int nstats, i;
901 	uint_t opt_a = FALSE;
902 	uint_t opt_b = FALSE;
903 	uint_t shift = 0;
904 	const char *suffix;
905 
906 	static const char *bytestats[] = {
907 		"p", "c", "c_min", "c_max", "size", NULL
908 	};
909 
910 	static const char *extras[] = {
911 		"arc_no_grow", "arc_tempreserve",
912 		"arc_meta_used", "arc_meta_limit", "arc_meta_max",
913 		NULL
914 	};
915 
916 	if (mdb_lookup_by_name("arc_stats", &sym) == -1) {
917 		mdb_warn("failed to find 'arc_stats'");
918 		return (DCMD_ERR);
919 	}
920 
921 	stats = mdb_zalloc(sym.st_size, UM_SLEEP | UM_GC);
922 
923 	if (mdb_vread(stats, sym.st_size, sym.st_value) == -1) {
924 		mdb_warn("couldn't read 'arc_stats' at %p", sym.st_value);
925 		return (DCMD_ERR);
926 	}
927 
928 	nstats = sym.st_size / sizeof (kstat_named_t);
929 
930 	/* NB: -a / opt_a are ignored for backwards compatability */
931 	if (mdb_getopts(argc, argv,
932 	    'a', MDB_OPT_SETBITS, TRUE, &opt_a,
933 	    'b', MDB_OPT_SETBITS, TRUE, &opt_b,
934 	    'k', MDB_OPT_SETBITS, 10, &shift,
935 	    'm', MDB_OPT_SETBITS, 20, &shift,
936 	    'g', MDB_OPT_SETBITS, 30, &shift,
937 	    NULL) != argc)
938 		return (DCMD_USAGE);
939 
940 	if (!opt_b && !shift)
941 		shift = 20;
942 
943 	switch (shift) {
944 	case 0:
945 		suffix = "B";
946 		break;
947 	case 10:
948 		suffix = "KB";
949 		break;
950 	case 20:
951 		suffix = "MB";
952 		break;
953 	case 30:
954 		suffix = "GB";
955 		break;
956 	default:
957 		suffix = "XX";
958 	}
959 
960 	for (i = 0; i < nstats; i++) {
961 		int j;
962 		boolean_t bytes = B_FALSE;
963 
964 		for (j = 0; bytestats[j]; j++) {
965 			if (strcmp(stats[i].name, bytestats[j]) == 0) {
966 				bytes = B_TRUE;
967 				break;
968 			}
969 		}
970 
971 		if (bytes) {
972 			mdb_printf("%-25s = %9llu %s\n", stats[i].name,
973 			    stats[i].value.ui64 >> shift, suffix);
974 		} else {
975 			mdb_printf("%-25s = %9llu\n", stats[i].name,
976 			    stats[i].value.ui64);
977 		}
978 	}
979 
980 	for (i = 0; extras[i]; i++) {
981 		uint64_t buf;
982 
983 		if (mdb_lookup_by_name(extras[i], &sym) == -1) {
984 			mdb_warn("failed to find '%s'", extras[i]);
985 			return (DCMD_ERR);
986 		}
987 
988 		if (sym.st_size != sizeof (uint64_t) &&
989 		    sym.st_size != sizeof (uint32_t)) {
990 			mdb_warn("expected scalar for variable '%s'\n",
991 			    extras[i]);
992 			return (DCMD_ERR);
993 		}
994 
995 		if (mdb_vread(&buf, sym.st_size, sym.st_value) == -1) {
996 			mdb_warn("couldn't read '%s'", extras[i]);
997 			return (DCMD_ERR);
998 		}
999 
1000 		mdb_printf("%-25s = ", extras[i]);
1001 
1002 		/* NB: all the 64-bit extras happen to be byte counts */
1003 		if (sym.st_size == sizeof (uint64_t))
1004 			mdb_printf("%9llu %s\n", buf >> shift, suffix);
1005 
1006 		if (sym.st_size == sizeof (uint32_t))
1007 			mdb_printf("%9d\n", *((uint32_t *)&buf));
1008 	}
1009 	return (DCMD_OK);
1010 }
1011 
1012 /*
1013  * ::spa
1014  *
1015  * 	-c	Print configuration information as well
1016  * 	-v	Print vdev state
1017  * 	-e	Print vdev error stats
1018  *
1019  * Print a summarized spa_t.  When given no arguments, prints out a table of all
1020  * active pools on the system.
1021  */
1022 /* ARGSUSED */
1023 static int
1024 spa_print(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
1025 {
1026 	spa_t spa;
1027 	const char *statetab[] = { "ACTIVE", "EXPORTED", "DESTROYED",
1028 		"SPARE", "L2CACHE", "UNINIT", "UNAVAIL", "POTENTIAL" };
1029 	const char *state;
1030 	int config = FALSE;
1031 	int vdevs = FALSE;
1032 	int errors = FALSE;
1033 
1034 	if (mdb_getopts(argc, argv,
1035 	    'c', MDB_OPT_SETBITS, TRUE, &config,
1036 	    'v', MDB_OPT_SETBITS, TRUE, &vdevs,
1037 	    'e', MDB_OPT_SETBITS, TRUE, &errors,
1038 	    NULL) != argc)
1039 		return (DCMD_USAGE);
1040 
1041 	if (!(flags & DCMD_ADDRSPEC)) {
1042 		if (mdb_walk_dcmd("spa", "spa", argc, argv) == -1) {
1043 			mdb_warn("can't walk spa");
1044 			return (DCMD_ERR);
1045 		}
1046 
1047 		return (DCMD_OK);
1048 	}
1049 
1050 	if (flags & DCMD_PIPE_OUT) {
1051 		mdb_printf("%#lr\n", addr);
1052 		return (DCMD_OK);
1053 	}
1054 
1055 	if (DCMD_HDRSPEC(flags))
1056 		mdb_printf("%<u>%-?s %9s %-*s%</u>\n", "ADDR", "STATE",
1057 		    sizeof (uintptr_t) == 4 ? 60 : 52, "NAME");
1058 
1059 	if (mdb_vread(&spa, sizeof (spa), addr) == -1) {
1060 		mdb_warn("failed to read spa_t at %p", addr);
1061 		return (DCMD_ERR);
1062 	}
1063 
1064 	if (spa.spa_state < 0 || spa.spa_state > POOL_STATE_UNAVAIL)
1065 		state = "UNKNOWN";
1066 	else
1067 		state = statetab[spa.spa_state];
1068 
1069 	mdb_printf("%0?p %9s %s\n", addr, state, spa.spa_name);
1070 
1071 	if (config) {
1072 		mdb_printf("\n");
1073 		mdb_inc_indent(4);
1074 		if (mdb_call_dcmd("spa_config", addr, flags, 0,
1075 		    NULL) != DCMD_OK)
1076 			return (DCMD_ERR);
1077 		mdb_dec_indent(4);
1078 	}
1079 
1080 	if (vdevs || errors) {
1081 		mdb_arg_t v;
1082 
1083 		v.a_type = MDB_TYPE_STRING;
1084 		v.a_un.a_str = "-e";
1085 
1086 		mdb_printf("\n");
1087 		mdb_inc_indent(4);
1088 		if (mdb_call_dcmd("spa_vdevs", addr, flags, errors ? 1 : 0,
1089 		    &v) != DCMD_OK)
1090 			return (DCMD_ERR);
1091 		mdb_dec_indent(4);
1092 	}
1093 
1094 	return (DCMD_OK);
1095 }
1096 
1097 /*
1098  * ::spa_config
1099  *
1100  * Given a spa_t, print the configuration information stored in spa_config.
1101  * Since it's just an nvlist, format it as an indented list of name=value pairs.
1102  * We simply read the value of spa_config and pass off to ::nvlist.
1103  */
1104 /* ARGSUSED */
1105 static int
1106 spa_print_config(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
1107 {
1108 	spa_t spa;
1109 
1110 	if (argc != 0 || !(flags & DCMD_ADDRSPEC))
1111 		return (DCMD_USAGE);
1112 
1113 	if (mdb_vread(&spa, sizeof (spa), addr) == -1) {
1114 		mdb_warn("failed to read spa_t at %p", addr);
1115 		return (DCMD_ERR);
1116 	}
1117 
1118 	if (spa.spa_config == NULL) {
1119 		mdb_printf("(none)\n");
1120 		return (DCMD_OK);
1121 	}
1122 
1123 	return (mdb_call_dcmd("nvlist", (uintptr_t)spa.spa_config, flags,
1124 	    0, NULL));
1125 }
1126 
1127 /*
1128  * ::vdev
1129  *
1130  * Print out a summarized vdev_t, in the following form:
1131  *
1132  * ADDR             STATE	AUX            DESC
1133  * fffffffbcde23df0 HEALTHY	-              /dev/dsk/c0t0d0
1134  *
1135  * If '-r' is specified, recursively visit all children.
1136  *
1137  * With '-e', the statistics associated with the vdev are printed as well.
1138  */
1139 static int
1140 do_print_vdev(uintptr_t addr, int flags, int depth, int stats,
1141     int recursive)
1142 {
1143 	vdev_t vdev;
1144 	char desc[MAXNAMELEN];
1145 	int c, children;
1146 	uintptr_t *child;
1147 	const char *state, *aux;
1148 
1149 	if (mdb_vread(&vdev, sizeof (vdev), (uintptr_t)addr) == -1) {
1150 		mdb_warn("failed to read vdev_t at %p\n", (uintptr_t)addr);
1151 		return (DCMD_ERR);
1152 	}
1153 
1154 	if (flags & DCMD_PIPE_OUT) {
1155 		mdb_printf("%#lr", addr);
1156 	} else {
1157 		if (vdev.vdev_path != NULL) {
1158 			if (mdb_readstr(desc, sizeof (desc),
1159 			    (uintptr_t)vdev.vdev_path) == -1) {
1160 				mdb_warn("failed to read vdev_path at %p\n",
1161 				    vdev.vdev_path);
1162 				return (DCMD_ERR);
1163 			}
1164 		} else if (vdev.vdev_ops != NULL) {
1165 			vdev_ops_t ops;
1166 			if (mdb_vread(&ops, sizeof (ops),
1167 			    (uintptr_t)vdev.vdev_ops) == -1) {
1168 				mdb_warn("failed to read vdev_ops at %p\n",
1169 				    vdev.vdev_ops);
1170 				return (DCMD_ERR);
1171 			}
1172 			(void) strcpy(desc, ops.vdev_op_type);
1173 		} else {
1174 			(void) strcpy(desc, "<unknown>");
1175 		}
1176 
1177 		if (depth == 0 && DCMD_HDRSPEC(flags))
1178 			mdb_printf("%<u>%-?s %-9s %-12s %-*s%</u>\n",
1179 			    "ADDR", "STATE", "AUX",
1180 			    sizeof (uintptr_t) == 4 ? 43 : 35,
1181 			    "DESCRIPTION");
1182 
1183 		mdb_printf("%0?p ", addr);
1184 
1185 		switch (vdev.vdev_state) {
1186 		case VDEV_STATE_CLOSED:
1187 			state = "CLOSED";
1188 			break;
1189 		case VDEV_STATE_OFFLINE:
1190 			state = "OFFLINE";
1191 			break;
1192 		case VDEV_STATE_CANT_OPEN:
1193 			state = "CANT_OPEN";
1194 			break;
1195 		case VDEV_STATE_DEGRADED:
1196 			state = "DEGRADED";
1197 			break;
1198 		case VDEV_STATE_HEALTHY:
1199 			state = "HEALTHY";
1200 			break;
1201 		case VDEV_STATE_REMOVED:
1202 			state = "REMOVED";
1203 			break;
1204 		case VDEV_STATE_FAULTED:
1205 			state = "FAULTED";
1206 			break;
1207 		default:
1208 			state = "UNKNOWN";
1209 			break;
1210 		}
1211 
1212 		switch (vdev.vdev_stat.vs_aux) {
1213 		case VDEV_AUX_NONE:
1214 			aux = "-";
1215 			break;
1216 		case VDEV_AUX_OPEN_FAILED:
1217 			aux = "OPEN_FAILED";
1218 			break;
1219 		case VDEV_AUX_CORRUPT_DATA:
1220 			aux = "CORRUPT_DATA";
1221 			break;
1222 		case VDEV_AUX_NO_REPLICAS:
1223 			aux = "NO_REPLICAS";
1224 			break;
1225 		case VDEV_AUX_BAD_GUID_SUM:
1226 			aux = "BAD_GUID_SUM";
1227 			break;
1228 		case VDEV_AUX_TOO_SMALL:
1229 			aux = "TOO_SMALL";
1230 			break;
1231 		case VDEV_AUX_BAD_LABEL:
1232 			aux = "BAD_LABEL";
1233 			break;
1234 		case VDEV_AUX_VERSION_NEWER:
1235 			aux = "VERS_NEWER";
1236 			break;
1237 		case VDEV_AUX_VERSION_OLDER:
1238 			aux = "VERS_OLDER";
1239 			break;
1240 		case VDEV_AUX_SPARED:
1241 			aux = "SPARED";
1242 			break;
1243 		case VDEV_AUX_ERR_EXCEEDED:
1244 			aux = "ERR_EXCEEDED";
1245 			break;
1246 		case VDEV_AUX_IO_FAILURE:
1247 			aux = "IO_FAILURE";
1248 			break;
1249 		case VDEV_AUX_BAD_LOG:
1250 			aux = "BAD_LOG";
1251 			break;
1252 		case VDEV_AUX_EXTERNAL:
1253 			aux = "EXTERNAL";
1254 			break;
1255 		case VDEV_AUX_SPLIT_POOL:
1256 			aux = "SPLIT_POOL";
1257 			break;
1258 		default:
1259 			aux = "UNKNOWN";
1260 			break;
1261 		}
1262 
1263 		mdb_printf("%-9s %-12s %*s%s\n", state, aux, depth, "", desc);
1264 
1265 		if (stats) {
1266 			vdev_stat_t *vs = &vdev.vdev_stat;
1267 			int i;
1268 
1269 			mdb_inc_indent(4);
1270 			mdb_printf("\n");
1271 			mdb_printf("%<u>       %12s %12s %12s %12s "
1272 			    "%12s%</u>\n", "READ", "WRITE", "FREE", "CLAIM",
1273 			    "IOCTL");
1274 			mdb_printf("OPS     ");
1275 			for (i = 1; i < ZIO_TYPES; i++)
1276 				mdb_printf("%11#llx%s", vs->vs_ops[i],
1277 				    i == ZIO_TYPES - 1 ? "" : "  ");
1278 			mdb_printf("\n");
1279 			mdb_printf("BYTES   ");
1280 			for (i = 1; i < ZIO_TYPES; i++)
1281 				mdb_printf("%11#llx%s", vs->vs_bytes[i],
1282 				    i == ZIO_TYPES - 1 ? "" : "  ");
1283 
1284 
1285 			mdb_printf("\n");
1286 			mdb_printf("EREAD    %10#llx\n", vs->vs_read_errors);
1287 			mdb_printf("EWRITE   %10#llx\n", vs->vs_write_errors);
1288 			mdb_printf("ECKSUM   %10#llx\n",
1289 			    vs->vs_checksum_errors);
1290 			mdb_dec_indent(4);
1291 		}
1292 
1293 		if (stats)
1294 			mdb_printf("\n");
1295 	}
1296 
1297 	children = vdev.vdev_children;
1298 
1299 	if (children == 0 || !recursive)
1300 		return (DCMD_OK);
1301 
1302 	child = mdb_alloc(children * sizeof (void *), UM_SLEEP | UM_GC);
1303 	if (mdb_vread(child, children * sizeof (void *),
1304 	    (uintptr_t)vdev.vdev_child) == -1) {
1305 		mdb_warn("failed to read vdev children at %p", vdev.vdev_child);
1306 		return (DCMD_ERR);
1307 	}
1308 
1309 	for (c = 0; c < children; c++) {
1310 		if (do_print_vdev(child[c], flags, depth + 2, stats,
1311 		    recursive))
1312 			return (DCMD_ERR);
1313 	}
1314 
1315 	return (DCMD_OK);
1316 }
1317 
1318 static int
1319 vdev_print(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
1320 {
1321 	int recursive = FALSE;
1322 	int stats = FALSE;
1323 	uint64_t depth = 0;
1324 
1325 	if (mdb_getopts(argc, argv,
1326 	    'r', MDB_OPT_SETBITS, TRUE, &recursive,
1327 	    'e', MDB_OPT_SETBITS, TRUE, &stats,
1328 	    'd', MDB_OPT_UINT64, &depth,
1329 	    NULL) != argc)
1330 		return (DCMD_USAGE);
1331 
1332 	if (!(flags & DCMD_ADDRSPEC)) {
1333 		mdb_warn("no vdev_t address given\n");
1334 		return (DCMD_ERR);
1335 	}
1336 
1337 	return (do_print_vdev(addr, flags, (int)depth, stats, recursive));
1338 }
1339 
1340 typedef struct metaslab_walk_data {
1341 	uint64_t mw_numvdevs;
1342 	uintptr_t *mw_vdevs;
1343 	int mw_curvdev;
1344 	uint64_t mw_nummss;
1345 	uintptr_t *mw_mss;
1346 	int mw_curms;
1347 } metaslab_walk_data_t;
1348 
1349 static int
1350 metaslab_walk_step(mdb_walk_state_t *wsp)
1351 {
1352 	metaslab_walk_data_t *mw = wsp->walk_data;
1353 	metaslab_t ms;
1354 	uintptr_t msp;
1355 
1356 	if (mw->mw_curvdev >= mw->mw_numvdevs)
1357 		return (WALK_DONE);
1358 
1359 	if (mw->mw_mss == NULL) {
1360 		uintptr_t mssp;
1361 		uintptr_t vdevp;
1362 
1363 		ASSERT(mw->mw_curms == 0);
1364 		ASSERT(mw->mw_nummss == 0);
1365 
1366 		vdevp = mw->mw_vdevs[mw->mw_curvdev];
1367 		if (GETMEMB(vdevp, struct vdev, vdev_ms, mssp) ||
1368 		    GETMEMB(vdevp, struct vdev, vdev_ms_count, mw->mw_nummss)) {
1369 			return (WALK_ERR);
1370 		}
1371 
1372 		mw->mw_mss = mdb_alloc(mw->mw_nummss * sizeof (void*),
1373 		    UM_SLEEP | UM_GC);
1374 		if (mdb_vread(mw->mw_mss, mw->mw_nummss * sizeof (void*),
1375 		    mssp) == -1) {
1376 			mdb_warn("failed to read vdev_ms at %p", mssp);
1377 			return (WALK_ERR);
1378 		}
1379 	}
1380 
1381 	if (mw->mw_curms >= mw->mw_nummss) {
1382 		mw->mw_mss = NULL;
1383 		mw->mw_curms = 0;
1384 		mw->mw_nummss = 0;
1385 		mw->mw_curvdev++;
1386 		return (WALK_NEXT);
1387 	}
1388 
1389 	msp = mw->mw_mss[mw->mw_curms];
1390 	if (mdb_vread(&ms, sizeof (metaslab_t), msp) == -1) {
1391 		mdb_warn("failed to read metaslab_t at %p", msp);
1392 		return (WALK_ERR);
1393 	}
1394 
1395 	mw->mw_curms++;
1396 
1397 	return (wsp->walk_callback(msp, &ms, wsp->walk_cbdata));
1398 }
1399 
1400 /* ARGSUSED */
1401 static int
1402 metaslab_walk_init(mdb_walk_state_t *wsp)
1403 {
1404 	metaslab_walk_data_t *mw;
1405 	uintptr_t root_vdevp;
1406 	uintptr_t childp;
1407 
1408 	if (wsp->walk_addr == NULL) {
1409 		mdb_warn("must supply address of spa_t\n");
1410 		return (WALK_ERR);
1411 	}
1412 
1413 	mw = mdb_zalloc(sizeof (metaslab_walk_data_t), UM_SLEEP | UM_GC);
1414 
1415 	if (GETMEMB(wsp->walk_addr, struct spa, spa_root_vdev, root_vdevp) ||
1416 	    GETMEMB(root_vdevp, struct vdev, vdev_children, mw->mw_numvdevs) ||
1417 	    GETMEMB(root_vdevp, struct vdev, vdev_child, childp)) {
1418 		return (DCMD_ERR);
1419 	}
1420 
1421 	mw->mw_vdevs = mdb_alloc(mw->mw_numvdevs * sizeof (void *),
1422 	    UM_SLEEP | UM_GC);
1423 	if (mdb_vread(mw->mw_vdevs, mw->mw_numvdevs * sizeof (void *),
1424 	    childp) == -1) {
1425 		mdb_warn("failed to read root vdev children at %p", childp);
1426 		return (DCMD_ERR);
1427 	}
1428 
1429 	wsp->walk_data = mw;
1430 
1431 	return (WALK_NEXT);
1432 }
1433 
1434 typedef struct mdb_spa {
1435 	uintptr_t spa_dsl_pool;
1436 	uintptr_t spa_root_vdev;
1437 } mdb_spa_t;
1438 
1439 typedef struct mdb_dsl_dir {
1440 	uintptr_t dd_phys;
1441 	int64_t dd_space_towrite[TXG_SIZE];
1442 } mdb_dsl_dir_t;
1443 
1444 typedef struct mdb_dsl_dir_phys {
1445 	uint64_t dd_used_bytes;
1446 	uint64_t dd_compressed_bytes;
1447 	uint64_t dd_uncompressed_bytes;
1448 } mdb_dsl_dir_phys_t;
1449 
1450 typedef struct mdb_vdev {
1451 	uintptr_t vdev_parent;
1452 	uintptr_t vdev_ms;
1453 	uint64_t vdev_ms_count;
1454 	vdev_stat_t vdev_stat;
1455 } mdb_vdev_t;
1456 
1457 typedef struct mdb_metaslab {
1458 	space_map_t ms_allocmap[TXG_SIZE];
1459 	space_map_t ms_freemap[TXG_SIZE];
1460 	space_map_t ms_map;
1461 	space_map_obj_t ms_smo;
1462 	space_map_obj_t ms_smo_syncing;
1463 } mdb_metaslab_t;
1464 
1465 typedef struct space_data {
1466 	uint64_t ms_allocmap[TXG_SIZE];
1467 	uint64_t ms_freemap[TXG_SIZE];
1468 	uint64_t ms_map;
1469 	uint64_t avail;
1470 	uint64_t nowavail;
1471 } space_data_t;
1472 
1473 /* ARGSUSED */
1474 static int
1475 space_cb(uintptr_t addr, const void *unknown, void *arg)
1476 {
1477 	space_data_t *sd = arg;
1478 	mdb_metaslab_t ms;
1479 
1480 	if (GETMEMB(addr, struct metaslab, ms_allocmap, ms.ms_allocmap) ||
1481 	    GETMEMB(addr, struct metaslab, ms_freemap, ms.ms_freemap) ||
1482 	    GETMEMB(addr, struct metaslab, ms_map, ms.ms_map) ||
1483 	    GETMEMB(addr, struct metaslab, ms_smo, ms.ms_smo) ||
1484 	    GETMEMB(addr, struct metaslab, ms_smo_syncing, ms.ms_smo_syncing)) {
1485 		return (WALK_ERR);
1486 	}
1487 
1488 	sd->ms_allocmap[0] += ms.ms_allocmap[0].sm_space;
1489 	sd->ms_allocmap[1] += ms.ms_allocmap[1].sm_space;
1490 	sd->ms_allocmap[2] += ms.ms_allocmap[2].sm_space;
1491 	sd->ms_allocmap[3] += ms.ms_allocmap[3].sm_space;
1492 	sd->ms_freemap[0] += ms.ms_freemap[0].sm_space;
1493 	sd->ms_freemap[1] += ms.ms_freemap[1].sm_space;
1494 	sd->ms_freemap[2] += ms.ms_freemap[2].sm_space;
1495 	sd->ms_freemap[3] += ms.ms_freemap[3].sm_space;
1496 	sd->ms_map += ms.ms_map.sm_space;
1497 	sd->avail += ms.ms_map.sm_size - ms.ms_smo.smo_alloc;
1498 	sd->nowavail += ms.ms_map.sm_size - ms.ms_smo_syncing.smo_alloc;
1499 
1500 	return (WALK_NEXT);
1501 }
1502 
1503 /*
1504  * ::spa_space [-b]
1505  *
1506  * Given a spa_t, print out it's on-disk space usage and in-core
1507  * estimates of future usage.  If -b is given, print space in bytes.
1508  * Otherwise print in megabytes.
1509  */
1510 /* ARGSUSED */
1511 static int
1512 spa_space(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
1513 {
1514 	mdb_spa_t spa;
1515 	uintptr_t dp_root_dir;
1516 	mdb_dsl_dir_t dd;
1517 	mdb_dsl_dir_phys_t dsp;
1518 	uint64_t children;
1519 	uintptr_t childaddr;
1520 	space_data_t sd;
1521 	int shift = 20;
1522 	char *suffix = "M";
1523 	int bits = FALSE;
1524 
1525 	if (mdb_getopts(argc, argv, 'b', MDB_OPT_SETBITS, TRUE, &bits, NULL) !=
1526 	    argc)
1527 		return (DCMD_USAGE);
1528 	if (!(flags & DCMD_ADDRSPEC))
1529 		return (DCMD_USAGE);
1530 
1531 	if (bits) {
1532 		shift = 0;
1533 		suffix = "";
1534 	}
1535 
1536 	if (GETMEMB(addr, struct spa, spa_dsl_pool, spa.spa_dsl_pool) ||
1537 	    GETMEMB(addr, struct spa, spa_root_vdev, spa.spa_root_vdev) ||
1538 	    GETMEMB(spa.spa_root_vdev, struct vdev, vdev_children, children) ||
1539 	    GETMEMB(spa.spa_root_vdev, struct vdev, vdev_child, childaddr) ||
1540 	    GETMEMB(spa.spa_dsl_pool, struct dsl_pool,
1541 	    dp_root_dir, dp_root_dir) ||
1542 	    GETMEMB(dp_root_dir, struct dsl_dir, dd_phys, dd.dd_phys) ||
1543 	    GETMEMB(dp_root_dir, struct dsl_dir,
1544 	    dd_space_towrite, dd.dd_space_towrite) ||
1545 	    GETMEMB(dd.dd_phys, struct dsl_dir_phys,
1546 	    dd_used_bytes, dsp.dd_used_bytes) ||
1547 	    GETMEMB(dd.dd_phys, struct dsl_dir_phys,
1548 	    dd_compressed_bytes, dsp.dd_compressed_bytes) ||
1549 	    GETMEMB(dd.dd_phys, struct dsl_dir_phys,
1550 	    dd_uncompressed_bytes, dsp.dd_uncompressed_bytes)) {
1551 		return (DCMD_ERR);
1552 	}
1553 
1554 	mdb_printf("dd_space_towrite = %llu%s %llu%s %llu%s %llu%s\n",
1555 	    dd.dd_space_towrite[0] >> shift, suffix,
1556 	    dd.dd_space_towrite[1] >> shift, suffix,
1557 	    dd.dd_space_towrite[2] >> shift, suffix,
1558 	    dd.dd_space_towrite[3] >> shift, suffix);
1559 
1560 	mdb_printf("dd_phys.dd_used_bytes = %llu%s\n",
1561 	    dsp.dd_used_bytes >> shift, suffix);
1562 	mdb_printf("dd_phys.dd_compressed_bytes = %llu%s\n",
1563 	    dsp.dd_compressed_bytes >> shift, suffix);
1564 	mdb_printf("dd_phys.dd_uncompressed_bytes = %llu%s\n",
1565 	    dsp.dd_uncompressed_bytes >> shift, suffix);
1566 
1567 	bzero(&sd, sizeof (sd));
1568 	if (mdb_pwalk("metaslab", space_cb, &sd, addr) != 0) {
1569 		mdb_warn("can't walk metaslabs");
1570 		return (DCMD_ERR);
1571 	}
1572 
1573 	mdb_printf("ms_allocmap = %llu%s %llu%s %llu%s %llu%s\n",
1574 	    sd.ms_allocmap[0] >> shift, suffix,
1575 	    sd.ms_allocmap[1] >> shift, suffix,
1576 	    sd.ms_allocmap[2] >> shift, suffix,
1577 	    sd.ms_allocmap[3] >> shift, suffix);
1578 	mdb_printf("ms_freemap = %llu%s %llu%s %llu%s %llu%s\n",
1579 	    sd.ms_freemap[0] >> shift, suffix,
1580 	    sd.ms_freemap[1] >> shift, suffix,
1581 	    sd.ms_freemap[2] >> shift, suffix,
1582 	    sd.ms_freemap[3] >> shift, suffix);
1583 	mdb_printf("ms_map = %llu%s\n", sd.ms_map >> shift, suffix);
1584 	mdb_printf("last synced avail = %llu%s\n", sd.avail >> shift, suffix);
1585 	mdb_printf("current syncing avail = %llu%s\n",
1586 	    sd.nowavail >> shift, suffix);
1587 
1588 	return (DCMD_OK);
1589 }
1590 
1591 /*
1592  * ::spa_verify
1593  *
1594  * Given a spa_t, verify that that the pool is self-consistent.
1595  * Currently, it only checks to make sure that the vdev tree exists.
1596  */
1597 /* ARGSUSED */
1598 static int
1599 spa_verify(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
1600 {
1601 	spa_t spa;
1602 
1603 	if (argc != 0 || !(flags & DCMD_ADDRSPEC))
1604 		return (DCMD_USAGE);
1605 
1606 	if (mdb_vread(&spa, sizeof (spa), addr) == -1) {
1607 		mdb_warn("failed to read spa_t at %p", addr);
1608 		return (DCMD_ERR);
1609 	}
1610 
1611 	if (spa.spa_root_vdev == NULL) {
1612 		mdb_printf("no vdev tree present\n");
1613 		return (DCMD_OK);
1614 	}
1615 
1616 	return (DCMD_OK);
1617 }
1618 
1619 static int
1620 spa_print_aux(spa_aux_vdev_t *sav, uint_t flags, mdb_arg_t *v,
1621     const char *name)
1622 {
1623 	uintptr_t *aux;
1624 	size_t len;
1625 	int ret, i;
1626 
1627 	/*
1628 	 * Iterate over aux vdevs and print those out as well.  This is a
1629 	 * little annoying because we don't have a root vdev to pass to ::vdev.
1630 	 * Instead, we print a single line and then call it for each child
1631 	 * vdev.
1632 	 */
1633 	if (sav->sav_count != 0) {
1634 		v[1].a_type = MDB_TYPE_STRING;
1635 		v[1].a_un.a_str = "-d";
1636 		v[2].a_type = MDB_TYPE_IMMEDIATE;
1637 		v[2].a_un.a_val = 2;
1638 
1639 		len = sav->sav_count * sizeof (uintptr_t);
1640 		aux = mdb_alloc(len, UM_SLEEP);
1641 		if (mdb_vread(aux, len,
1642 		    (uintptr_t)sav->sav_vdevs) == -1) {
1643 			mdb_free(aux, len);
1644 			mdb_warn("failed to read l2cache vdevs at %p",
1645 			    sav->sav_vdevs);
1646 			return (DCMD_ERR);
1647 		}
1648 
1649 		mdb_printf("%-?s %-9s %-12s %s\n", "-", "-", "-", name);
1650 
1651 		for (i = 0; i < sav->sav_count; i++) {
1652 			ret = mdb_call_dcmd("vdev", aux[i], flags, 3, v);
1653 			if (ret != DCMD_OK) {
1654 				mdb_free(aux, len);
1655 				return (ret);
1656 			}
1657 		}
1658 
1659 		mdb_free(aux, len);
1660 	}
1661 
1662 	return (0);
1663 }
1664 
1665 /*
1666  * ::spa_vdevs
1667  *
1668  * 	-e	Include error stats
1669  *
1670  * Print out a summarized list of vdevs for the given spa_t.
1671  * This is accomplished by invoking "::vdev -re" on the root vdev, as well as
1672  * iterating over the cache devices.
1673  */
1674 /* ARGSUSED */
1675 static int
1676 spa_vdevs(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
1677 {
1678 	spa_t spa;
1679 	mdb_arg_t v[3];
1680 	int errors = FALSE;
1681 	int ret;
1682 
1683 	if (mdb_getopts(argc, argv,
1684 	    'e', MDB_OPT_SETBITS, TRUE, &errors,
1685 	    NULL) != argc)
1686 		return (DCMD_USAGE);
1687 
1688 	if (!(flags & DCMD_ADDRSPEC))
1689 		return (DCMD_USAGE);
1690 
1691 	if (mdb_vread(&spa, sizeof (spa), addr) == -1) {
1692 		mdb_warn("failed to read spa_t at %p", addr);
1693 		return (DCMD_ERR);
1694 	}
1695 
1696 	/*
1697 	 * Unitialized spa_t structures can have a NULL root vdev.
1698 	 */
1699 	if (spa.spa_root_vdev == NULL) {
1700 		mdb_printf("no associated vdevs\n");
1701 		return (DCMD_OK);
1702 	}
1703 
1704 	v[0].a_type = MDB_TYPE_STRING;
1705 	v[0].a_un.a_str = errors ? "-re" : "-r";
1706 
1707 	ret = mdb_call_dcmd("vdev", (uintptr_t)spa.spa_root_vdev,
1708 	    flags, 1, v);
1709 	if (ret != DCMD_OK)
1710 		return (ret);
1711 
1712 	if (spa_print_aux(&spa.spa_l2cache, flags, v, "cache") != 0 ||
1713 	    spa_print_aux(&spa.spa_spares, flags, v, "spares") != 0)
1714 		return (DCMD_ERR);
1715 
1716 	return (DCMD_OK);
1717 }
1718 
1719 /*
1720  * ::zio
1721  *
1722  * Print a summary of zio_t and all its children.  This is intended to display a
1723  * zio tree, and hence we only pick the most important pieces of information for
1724  * the main summary.  More detailed information can always be found by doing a
1725  * '::print zio' on the underlying zio_t.  The columns we display are:
1726  *
1727  *	ADDRESS		TYPE	STAGE		WAITER
1728  *
1729  * The 'address' column is indented by one space for each depth level as we
1730  * descend down the tree.
1731  */
1732 
1733 #define	ZIO_MAXINDENT	24
1734 #define	ZIO_MAXWIDTH	(sizeof (uintptr_t) * 2 + ZIO_MAXINDENT)
1735 #define	ZIO_WALK_SELF	0
1736 #define	ZIO_WALK_CHILD	1
1737 #define	ZIO_WALK_PARENT	2
1738 
1739 typedef struct zio_print_args {
1740 	int	zpa_current_depth;
1741 	int	zpa_min_depth;
1742 	int	zpa_max_depth;
1743 	int	zpa_type;
1744 	uint_t	zpa_flags;
1745 } zio_print_args_t;
1746 
1747 static int zio_child_cb(uintptr_t addr, const void *unknown, void *arg);
1748 
1749 static int
1750 zio_print_cb(uintptr_t addr, const void *data, void *priv)
1751 {
1752 	const zio_t *zio = data;
1753 	zio_print_args_t *zpa = priv;
1754 	mdb_ctf_id_t type_enum, stage_enum;
1755 	int indent = zpa->zpa_current_depth;
1756 	const char *type, *stage;
1757 	uintptr_t laddr;
1758 
1759 	if (indent > ZIO_MAXINDENT)
1760 		indent = ZIO_MAXINDENT;
1761 
1762 	if (mdb_ctf_lookup_by_name("enum zio_type", &type_enum) == -1 ||
1763 	    mdb_ctf_lookup_by_name("enum zio_stage", &stage_enum) == -1) {
1764 		mdb_warn("failed to lookup zio enums");
1765 		return (WALK_ERR);
1766 	}
1767 
1768 	if ((type = mdb_ctf_enum_name(type_enum, zio->io_type)) != NULL)
1769 		type += sizeof ("ZIO_TYPE_") - 1;
1770 	else
1771 		type = "?";
1772 
1773 	if ((stage = mdb_ctf_enum_name(stage_enum, zio->io_stage)) != NULL)
1774 		stage += sizeof ("ZIO_STAGE_") - 1;
1775 	else
1776 		stage = "?";
1777 
1778 	if (zpa->zpa_current_depth >= zpa->zpa_min_depth) {
1779 		if (zpa->zpa_flags & DCMD_PIPE_OUT) {
1780 			mdb_printf("%?p\n", addr);
1781 		} else {
1782 			mdb_printf("%*s%-*p %-5s %-16s ", indent, "",
1783 			    ZIO_MAXWIDTH - indent, addr, type, stage);
1784 			if (zio->io_waiter)
1785 				mdb_printf("%?p\n", zio->io_waiter);
1786 			else
1787 				mdb_printf("-\n");
1788 		}
1789 	}
1790 
1791 	if (zpa->zpa_current_depth >= zpa->zpa_max_depth)
1792 		return (WALK_NEXT);
1793 
1794 	if (zpa->zpa_type == ZIO_WALK_PARENT)
1795 		laddr = addr + OFFSETOF(zio_t, io_parent_list);
1796 	else
1797 		laddr = addr + OFFSETOF(zio_t, io_child_list);
1798 
1799 	zpa->zpa_current_depth++;
1800 	if (mdb_pwalk("list", zio_child_cb, zpa, laddr) != 0) {
1801 		mdb_warn("failed to walk zio_t children at %p\n", laddr);
1802 		return (WALK_ERR);
1803 	}
1804 	zpa->zpa_current_depth--;
1805 
1806 	return (WALK_NEXT);
1807 }
1808 
1809 /* ARGSUSED */
1810 static int
1811 zio_child_cb(uintptr_t addr, const void *unknown, void *arg)
1812 {
1813 	zio_link_t zl;
1814 	zio_t zio;
1815 	uintptr_t ziop;
1816 	zio_print_args_t *zpa = arg;
1817 
1818 	if (mdb_vread(&zl, sizeof (zl), addr) == -1) {
1819 		mdb_warn("failed to read zio_link_t at %p", addr);
1820 		return (WALK_ERR);
1821 	}
1822 
1823 	if (zpa->zpa_type == ZIO_WALK_PARENT)
1824 		ziop = (uintptr_t)zl.zl_parent;
1825 	else
1826 		ziop = (uintptr_t)zl.zl_child;
1827 
1828 	if (mdb_vread(&zio, sizeof (zio_t), ziop) == -1) {
1829 		mdb_warn("failed to read zio_t at %p", ziop);
1830 		return (WALK_ERR);
1831 	}
1832 
1833 	return (zio_print_cb(ziop, &zio, arg));
1834 }
1835 
1836 /* ARGSUSED */
1837 static int
1838 zio_print(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
1839 {
1840 	zio_t zio;
1841 	zio_print_args_t zpa = { 0 };
1842 
1843 	if (!(flags & DCMD_ADDRSPEC))
1844 		return (DCMD_USAGE);
1845 
1846 	if (mdb_getopts(argc, argv,
1847 	    'r', MDB_OPT_SETBITS, INT_MAX, &zpa.zpa_max_depth,
1848 	    'c', MDB_OPT_SETBITS, ZIO_WALK_CHILD, &zpa.zpa_type,
1849 	    'p', MDB_OPT_SETBITS, ZIO_WALK_PARENT, &zpa.zpa_type,
1850 	    NULL) != argc)
1851 		return (DCMD_USAGE);
1852 
1853 	zpa.zpa_flags = flags;
1854 	if (zpa.zpa_max_depth != 0) {
1855 		if (zpa.zpa_type == ZIO_WALK_SELF)
1856 			zpa.zpa_type = ZIO_WALK_CHILD;
1857 	} else if (zpa.zpa_type != ZIO_WALK_SELF) {
1858 		zpa.zpa_min_depth = 1;
1859 		zpa.zpa_max_depth = 1;
1860 	}
1861 
1862 	if (mdb_vread(&zio, sizeof (zio_t), addr) == -1) {
1863 		mdb_warn("failed to read zio_t at %p", addr);
1864 		return (DCMD_ERR);
1865 	}
1866 
1867 	if (!(flags & DCMD_PIPE_OUT) && DCMD_HDRSPEC(flags))
1868 		mdb_printf("%<u>%-*s %-5s %-16s %-?s%</u>\n", ZIO_MAXWIDTH,
1869 		    "ADDRESS", "TYPE", "STAGE", "WAITER");
1870 
1871 	if (zio_print_cb(addr, &zio, &zpa) != WALK_NEXT)
1872 		return (DCMD_ERR);
1873 
1874 	return (DCMD_OK);
1875 }
1876 
1877 /*
1878  * [addr]::zio_state
1879  *
1880  * Print a summary of all zio_t structures on the system, or for a particular
1881  * pool.  This is equivalent to '::walk zio_root | ::zio'.
1882  */
1883 /*ARGSUSED*/
1884 static int
1885 zio_state(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
1886 {
1887 	/*
1888 	 * MDB will remember the last address of the pipeline, so if we don't
1889 	 * zero this we'll end up trying to walk zio structures for a
1890 	 * non-existent spa_t.
1891 	 */
1892 	if (!(flags & DCMD_ADDRSPEC))
1893 		addr = 0;
1894 
1895 	return (mdb_pwalk_dcmd("zio_root", "zio", argc, argv, addr));
1896 }
1897 
1898 typedef struct txg_list_walk_data {
1899 	uintptr_t lw_head[TXG_SIZE];
1900 	int	lw_txgoff;
1901 	int	lw_maxoff;
1902 	size_t	lw_offset;
1903 	void	*lw_obj;
1904 } txg_list_walk_data_t;
1905 
1906 static int
1907 txg_list_walk_init_common(mdb_walk_state_t *wsp, int txg, int maxoff)
1908 {
1909 	txg_list_walk_data_t *lwd;
1910 	txg_list_t list;
1911 	int i;
1912 
1913 	lwd = mdb_alloc(sizeof (txg_list_walk_data_t), UM_SLEEP | UM_GC);
1914 	if (mdb_vread(&list, sizeof (txg_list_t), wsp->walk_addr) == -1) {
1915 		mdb_warn("failed to read txg_list_t at %#lx", wsp->walk_addr);
1916 		return (WALK_ERR);
1917 	}
1918 
1919 	for (i = 0; i < TXG_SIZE; i++)
1920 		lwd->lw_head[i] = (uintptr_t)list.tl_head[i];
1921 	lwd->lw_offset = list.tl_offset;
1922 	lwd->lw_obj = mdb_alloc(lwd->lw_offset + sizeof (txg_node_t),
1923 	    UM_SLEEP | UM_GC);
1924 	lwd->lw_txgoff = txg;
1925 	lwd->lw_maxoff = maxoff;
1926 
1927 	wsp->walk_addr = lwd->lw_head[lwd->lw_txgoff];
1928 	wsp->walk_data = lwd;
1929 
1930 	return (WALK_NEXT);
1931 }
1932 
1933 static int
1934 txg_list_walk_init(mdb_walk_state_t *wsp)
1935 {
1936 	return (txg_list_walk_init_common(wsp, 0, TXG_SIZE-1));
1937 }
1938 
1939 static int
1940 txg_list0_walk_init(mdb_walk_state_t *wsp)
1941 {
1942 	return (txg_list_walk_init_common(wsp, 0, 0));
1943 }
1944 
1945 static int
1946 txg_list1_walk_init(mdb_walk_state_t *wsp)
1947 {
1948 	return (txg_list_walk_init_common(wsp, 1, 1));
1949 }
1950 
1951 static int
1952 txg_list2_walk_init(mdb_walk_state_t *wsp)
1953 {
1954 	return (txg_list_walk_init_common(wsp, 2, 2));
1955 }
1956 
1957 static int
1958 txg_list3_walk_init(mdb_walk_state_t *wsp)
1959 {
1960 	return (txg_list_walk_init_common(wsp, 3, 3));
1961 }
1962 
1963 static int
1964 txg_list_walk_step(mdb_walk_state_t *wsp)
1965 {
1966 	txg_list_walk_data_t *lwd = wsp->walk_data;
1967 	uintptr_t addr;
1968 	txg_node_t *node;
1969 	int status;
1970 
1971 	while (wsp->walk_addr == NULL && lwd->lw_txgoff < lwd->lw_maxoff) {
1972 		lwd->lw_txgoff++;
1973 		wsp->walk_addr = lwd->lw_head[lwd->lw_txgoff];
1974 	}
1975 
1976 	if (wsp->walk_addr == NULL)
1977 		return (WALK_DONE);
1978 
1979 	addr = wsp->walk_addr - lwd->lw_offset;
1980 
1981 	if (mdb_vread(lwd->lw_obj,
1982 	    lwd->lw_offset + sizeof (txg_node_t), addr) == -1) {
1983 		mdb_warn("failed to read list element at %#lx", addr);
1984 		return (WALK_ERR);
1985 	}
1986 
1987 	status = wsp->walk_callback(addr, lwd->lw_obj, wsp->walk_cbdata);
1988 	node = (txg_node_t *)((uintptr_t)lwd->lw_obj + lwd->lw_offset);
1989 	wsp->walk_addr = (uintptr_t)node->tn_next[lwd->lw_txgoff];
1990 
1991 	return (status);
1992 }
1993 
1994 /*
1995  * ::walk spa
1996  *
1997  * Walk all named spa_t structures in the namespace.  This is nothing more than
1998  * a layered avl walk.
1999  */
2000 static int
2001 spa_walk_init(mdb_walk_state_t *wsp)
2002 {
2003 	GElf_Sym sym;
2004 
2005 	if (wsp->walk_addr != NULL) {
2006 		mdb_warn("spa walk only supports global walks\n");
2007 		return (WALK_ERR);
2008 	}
2009 
2010 	if (mdb_lookup_by_obj(ZFS_OBJ_NAME, "spa_namespace_avl", &sym) == -1) {
2011 		mdb_warn("failed to find symbol 'spa_namespace_avl'");
2012 		return (WALK_ERR);
2013 	}
2014 
2015 	wsp->walk_addr = (uintptr_t)sym.st_value;
2016 
2017 	if (mdb_layered_walk("avl", wsp) == -1) {
2018 		mdb_warn("failed to walk 'avl'\n");
2019 		return (WALK_ERR);
2020 	}
2021 
2022 	return (WALK_NEXT);
2023 }
2024 
2025 static int
2026 spa_walk_step(mdb_walk_state_t *wsp)
2027 {
2028 	spa_t	spa;
2029 
2030 	if (mdb_vread(&spa, sizeof (spa), wsp->walk_addr) == -1) {
2031 		mdb_warn("failed to read spa_t at %p", wsp->walk_addr);
2032 		return (WALK_ERR);
2033 	}
2034 
2035 	return (wsp->walk_callback(wsp->walk_addr, &spa, wsp->walk_cbdata));
2036 }
2037 
2038 /*
2039  * [addr]::walk zio
2040  *
2041  * Walk all active zio_t structures on the system.  This is simply a layered
2042  * walk on top of ::walk zio_cache, with the optional ability to limit the
2043  * structures to a particular pool.
2044  */
2045 static int
2046 zio_walk_init(mdb_walk_state_t *wsp)
2047 {
2048 	wsp->walk_data = (void *)wsp->walk_addr;
2049 
2050 	if (mdb_layered_walk("zio_cache", wsp) == -1) {
2051 		mdb_warn("failed to walk 'zio_cache'\n");
2052 		return (WALK_ERR);
2053 	}
2054 
2055 	return (WALK_NEXT);
2056 }
2057 
2058 static int
2059 zio_walk_step(mdb_walk_state_t *wsp)
2060 {
2061 	zio_t zio;
2062 
2063 	if (mdb_vread(&zio, sizeof (zio), wsp->walk_addr) == -1) {
2064 		mdb_warn("failed to read zio_t at %p", wsp->walk_addr);
2065 		return (WALK_ERR);
2066 	}
2067 
2068 	if (wsp->walk_data != NULL && wsp->walk_data != zio.io_spa)
2069 		return (WALK_NEXT);
2070 
2071 	return (wsp->walk_callback(wsp->walk_addr, &zio, wsp->walk_cbdata));
2072 }
2073 
2074 /*
2075  * [addr]::walk zio_root
2076  *
2077  * Walk only root zio_t structures, optionally for a particular spa_t.
2078  */
2079 static int
2080 zio_walk_root_step(mdb_walk_state_t *wsp)
2081 {
2082 	zio_t zio;
2083 
2084 	if (mdb_vread(&zio, sizeof (zio), wsp->walk_addr) == -1) {
2085 		mdb_warn("failed to read zio_t at %p", wsp->walk_addr);
2086 		return (WALK_ERR);
2087 	}
2088 
2089 	if (wsp->walk_data != NULL && wsp->walk_data != zio.io_spa)
2090 		return (WALK_NEXT);
2091 
2092 	/* If the parent list is not empty, ignore */
2093 	if (zio.io_parent_list.list_head.list_next !=
2094 	    &((zio_t *)wsp->walk_addr)->io_parent_list.list_head)
2095 		return (WALK_NEXT);
2096 
2097 	return (wsp->walk_callback(wsp->walk_addr, &zio, wsp->walk_cbdata));
2098 }
2099 
2100 #define	NICENUM_BUFLEN 6
2101 
2102 static int
2103 snprintfrac(char *buf, int len,
2104     uint64_t numerator, uint64_t denom, int frac_digits)
2105 {
2106 	int mul = 1;
2107 	int whole, frac, i;
2108 
2109 	for (i = frac_digits; i; i--)
2110 		mul *= 10;
2111 	whole = numerator / denom;
2112 	frac = mul * numerator / denom - mul * whole;
2113 	return (mdb_snprintf(buf, len, "%u.%0*u", whole, frac_digits, frac));
2114 }
2115 
2116 static void
2117 mdb_nicenum(uint64_t num, char *buf)
2118 {
2119 	uint64_t n = num;
2120 	int index = 0;
2121 	char *u;
2122 
2123 	while (n >= 1024) {
2124 		n = (n + (1024 / 2)) / 1024; /* Round up or down */
2125 		index++;
2126 	}
2127 
2128 	u = &" \0K\0M\0G\0T\0P\0E\0"[index*2];
2129 
2130 	if (index == 0) {
2131 		(void) mdb_snprintf(buf, NICENUM_BUFLEN, "%llu",
2132 		    (u_longlong_t)n);
2133 	} else if (n < 10 && (num & (num - 1)) != 0) {
2134 		(void) snprintfrac(buf, NICENUM_BUFLEN,
2135 		    num, 1ULL << 10 * index, 2);
2136 		strcat(buf, u);
2137 	} else if (n < 100 && (num & (num - 1)) != 0) {
2138 		(void) snprintfrac(buf, NICENUM_BUFLEN,
2139 		    num, 1ULL << 10 * index, 1);
2140 		strcat(buf, u);
2141 	} else {
2142 		(void) mdb_snprintf(buf, NICENUM_BUFLEN, "%llu%s",
2143 		    (u_longlong_t)n, u);
2144 	}
2145 }
2146 
2147 /*
2148  * ::zfs_blkstats
2149  *
2150  * 	-v	print verbose per-level information
2151  *
2152  */
2153 static int
2154 zfs_blkstats(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
2155 {
2156 	boolean_t verbose = B_FALSE;
2157 	zfs_all_blkstats_t stats;
2158 	dmu_object_type_t t;
2159 	zfs_blkstat_t *tzb;
2160 	uint64_t ditto;
2161 	dmu_object_type_info_t dmu_ot[DMU_OT_NUMTYPES + 10];
2162 	/* +10 in case it grew */
2163 
2164 	if (mdb_readvar(&dmu_ot, "dmu_ot") == -1) {
2165 		mdb_warn("failed to read 'dmu_ot'");
2166 		return (DCMD_ERR);
2167 	}
2168 
2169 	if (mdb_getopts(argc, argv,
2170 	    'v', MDB_OPT_SETBITS, TRUE, &verbose,
2171 	    NULL) != argc)
2172 		return (DCMD_USAGE);
2173 
2174 	if (!(flags & DCMD_ADDRSPEC))
2175 		return (DCMD_USAGE);
2176 
2177 	if (GETMEMB(addr, struct spa, spa_dsl_pool, addr) ||
2178 	    GETMEMB(addr, struct dsl_pool, dp_blkstats, addr) ||
2179 	    mdb_vread(&stats, sizeof (zfs_all_blkstats_t), addr) == -1) {
2180 		mdb_warn("failed to read data at %p;", addr);
2181 		mdb_printf("maybe no stats? run \"zpool scrub\" first.");
2182 		return (DCMD_ERR);
2183 	}
2184 
2185 	tzb = &stats.zab_type[DN_MAX_LEVELS][DMU_OT_NUMTYPES];
2186 	if (tzb->zb_gangs != 0) {
2187 		mdb_printf("Ganged blocks: %llu\n",
2188 		    (longlong_t)tzb->zb_gangs);
2189 	}
2190 
2191 	ditto = tzb->zb_ditto_2_of_2_samevdev + tzb->zb_ditto_2_of_3_samevdev +
2192 	    tzb->zb_ditto_3_of_3_samevdev;
2193 	if (ditto != 0) {
2194 		mdb_printf("Dittoed blocks on same vdev: %llu\n",
2195 		    (longlong_t)ditto);
2196 	}
2197 
2198 	mdb_printf("\nBlocks\tLSIZE\tPSIZE\tASIZE"
2199 	    "\t  avg\t comp\t%%Total\tType\n");
2200 
2201 	for (t = 0; t <= DMU_OT_NUMTYPES; t++) {
2202 		char csize[NICENUM_BUFLEN], lsize[NICENUM_BUFLEN];
2203 		char psize[NICENUM_BUFLEN], asize[NICENUM_BUFLEN];
2204 		char avg[NICENUM_BUFLEN];
2205 		char comp[NICENUM_BUFLEN], pct[NICENUM_BUFLEN];
2206 		char typename[64];
2207 		int l;
2208 
2209 
2210 		if (t == DMU_OT_DEFERRED)
2211 			strcpy(typename, "deferred free");
2212 		else if (t == DMU_OT_TOTAL)
2213 			strcpy(typename, "Total");
2214 		else if (mdb_readstr(typename, sizeof (typename),
2215 		    (uintptr_t)dmu_ot[t].ot_name) == -1) {
2216 			mdb_warn("failed to read type name");
2217 			return (DCMD_ERR);
2218 		}
2219 
2220 		if (stats.zab_type[DN_MAX_LEVELS][t].zb_asize == 0)
2221 			continue;
2222 
2223 		for (l = -1; l < DN_MAX_LEVELS; l++) {
2224 			int level = (l == -1 ? DN_MAX_LEVELS : l);
2225 			zfs_blkstat_t *zb = &stats.zab_type[level][t];
2226 
2227 			if (zb->zb_asize == 0)
2228 				continue;
2229 
2230 			/*
2231 			 * Don't print each level unless requested.
2232 			 */
2233 			if (!verbose && level != DN_MAX_LEVELS)
2234 				continue;
2235 
2236 			/*
2237 			 * If all the space is level 0, don't print the
2238 			 * level 0 separately.
2239 			 */
2240 			if (level == 0 && zb->zb_asize ==
2241 			    stats.zab_type[DN_MAX_LEVELS][t].zb_asize)
2242 				continue;
2243 
2244 			mdb_nicenum(zb->zb_count, csize);
2245 			mdb_nicenum(zb->zb_lsize, lsize);
2246 			mdb_nicenum(zb->zb_psize, psize);
2247 			mdb_nicenum(zb->zb_asize, asize);
2248 			mdb_nicenum(zb->zb_asize / zb->zb_count, avg);
2249 			(void) snprintfrac(comp, NICENUM_BUFLEN,
2250 			    zb->zb_lsize, zb->zb_psize, 2);
2251 			(void) snprintfrac(pct, NICENUM_BUFLEN,
2252 			    100 * zb->zb_asize, tzb->zb_asize, 2);
2253 
2254 			mdb_printf("%6s\t%5s\t%5s\t%5s\t%5s"
2255 			    "\t%5s\t%6s\t",
2256 			    csize, lsize, psize, asize, avg, comp, pct);
2257 
2258 			if (level == DN_MAX_LEVELS)
2259 				mdb_printf("%s\n", typename);
2260 			else
2261 				mdb_printf("  L%d %s\n",
2262 				    level, typename);
2263 		}
2264 	}
2265 
2266 	return (DCMD_OK);
2267 }
2268 
2269 /* ARGSUSED */
2270 static int
2271 reference_cb(uintptr_t addr, const void *ignored, void *arg)
2272 {
2273 	static int gotid;
2274 	static mdb_ctf_id_t ref_id;
2275 	uintptr_t ref_holder;
2276 	uintptr_t ref_removed;
2277 	uint64_t ref_number;
2278 	boolean_t holder_is_str = B_FALSE;
2279 	char holder_str[128];
2280 	boolean_t removed = (boolean_t)arg;
2281 
2282 	if (!gotid) {
2283 		if (mdb_ctf_lookup_by_name("struct reference", &ref_id) == -1) {
2284 			mdb_warn("couldn't find struct reference");
2285 			return (WALK_ERR);
2286 		}
2287 		gotid = TRUE;
2288 	}
2289 
2290 	if (GETMEMBID(addr, &ref_id, ref_holder, ref_holder) ||
2291 	    GETMEMBID(addr, &ref_id, ref_removed, ref_removed) ||
2292 	    GETMEMBID(addr, &ref_id, ref_number, ref_number))
2293 		return (WALK_ERR);
2294 
2295 	if (mdb_readstr(holder_str, sizeof (holder_str), ref_holder) != -1)
2296 		holder_is_str = strisprint(holder_str);
2297 
2298 	if (removed)
2299 		mdb_printf("removed ");
2300 	mdb_printf("reference ");
2301 	if (ref_number != 1)
2302 		mdb_printf("with count=%llu ", ref_number);
2303 	mdb_printf("with tag %p", (void*)ref_holder);
2304 	if (holder_is_str)
2305 		mdb_printf(" \"%s\"", holder_str);
2306 	mdb_printf(", held at:\n");
2307 
2308 	(void) mdb_call_dcmd("whatis", addr, DCMD_ADDRSPEC, 0, NULL);
2309 
2310 	if (removed) {
2311 		mdb_printf("removed at:\n");
2312 		(void) mdb_call_dcmd("whatis", ref_removed,
2313 		    DCMD_ADDRSPEC, 0, NULL);
2314 	}
2315 
2316 	mdb_printf("\n");
2317 
2318 	return (WALK_NEXT);
2319 }
2320 
2321 /* ARGSUSED */
2322 static int
2323 refcount(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
2324 {
2325 	uint64_t rc_count, rc_removed_count;
2326 	uintptr_t rc_list, rc_removed;
2327 	static int gotid;
2328 	static mdb_ctf_id_t rc_id;
2329 	ulong_t off;
2330 
2331 	if (!(flags & DCMD_ADDRSPEC))
2332 		return (DCMD_USAGE);
2333 
2334 	if (!gotid) {
2335 		if (mdb_ctf_lookup_by_name("struct refcount", &rc_id) == -1) {
2336 			mdb_warn("couldn't find struct refcount");
2337 			return (DCMD_ERR);
2338 		}
2339 		gotid = TRUE;
2340 	}
2341 
2342 	if (GETMEMBID(addr, &rc_id, rc_count, rc_count) ||
2343 	    GETMEMBID(addr, &rc_id, rc_removed_count, rc_removed_count))
2344 		return (DCMD_ERR);
2345 
2346 	mdb_printf("refcount_t at %p has %llu current holds, "
2347 	    "%llu recently released holds\n",
2348 	    addr, (longlong_t)rc_count, (longlong_t)rc_removed_count);
2349 
2350 	if (rc_count > 0)
2351 		mdb_printf("current holds:\n");
2352 	if (mdb_ctf_offsetof(rc_id, "rc_list", &off) == -1)
2353 		return (DCMD_ERR);
2354 	rc_list = addr + off/NBBY;
2355 	mdb_pwalk("list", reference_cb, (void*)B_FALSE, rc_list);
2356 
2357 	if (rc_removed_count > 0)
2358 		mdb_printf("released holds:\n");
2359 	if (mdb_ctf_offsetof(rc_id, "rc_removed", &off) == -1)
2360 		return (DCMD_ERR);
2361 	rc_removed = addr + off/NBBY;
2362 	mdb_pwalk("list", reference_cb, (void*)B_TRUE, rc_removed);
2363 
2364 	return (DCMD_OK);
2365 }
2366 
2367 /* ARGSUSED */
2368 static int
2369 sa_attr_table(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
2370 {
2371 	sa_attr_table_t *table;
2372 	sa_os_t sa_os;
2373 	char *name;
2374 	int i;
2375 
2376 	if (mdb_vread(&sa_os, sizeof (sa_os_t), addr) == -1) {
2377 		mdb_warn("failed to read sa_os at %p", addr);
2378 		return (DCMD_ERR);
2379 	}
2380 
2381 	table = mdb_alloc(sizeof (sa_attr_table_t) * sa_os.sa_num_attrs,
2382 	    UM_SLEEP | UM_GC);
2383 	name = mdb_alloc(MAXPATHLEN, UM_SLEEP | UM_GC);
2384 
2385 	if (mdb_vread(table, sizeof (sa_attr_table_t) * sa_os.sa_num_attrs,
2386 	    (uintptr_t)sa_os.sa_attr_table) == -1) {
2387 		mdb_warn("failed to read sa_os at %p", addr);
2388 		return (DCMD_ERR);
2389 	}
2390 
2391 	mdb_printf("%<u>%-10s %-10s %-10s %-10s %s%</u>\n",
2392 	    "ATTR ID", "REGISTERED", "LENGTH", "BSWAP", "NAME");
2393 	for (i = 0; i != sa_os.sa_num_attrs; i++) {
2394 		mdb_readstr(name, MAXPATHLEN, (uintptr_t)table[i].sa_name);
2395 		mdb_printf("%5x   %8x %8x %8x          %-s\n",
2396 		    (int)table[i].sa_attr, (int)table[i].sa_registered,
2397 		    (int)table[i].sa_length, table[i].sa_byteswap, name);
2398 	}
2399 
2400 	return (DCMD_OK);
2401 }
2402 
2403 static int
2404 sa_get_off_table(uintptr_t addr, uint32_t **off_tab, int attr_count)
2405 {
2406 	uintptr_t idx_table;
2407 
2408 	if (GETMEMB(addr, struct sa_idx_tab, sa_idx_tab, idx_table)) {
2409 		mdb_printf("can't find offset table in sa_idx_tab\n");
2410 		return (-1);
2411 	}
2412 
2413 	*off_tab = mdb_alloc(attr_count * sizeof (uint32_t),
2414 	    UM_SLEEP | UM_GC);
2415 
2416 	if (mdb_vread(*off_tab,
2417 	    attr_count * sizeof (uint32_t), idx_table) == -1) {
2418 		mdb_warn("failed to attribute offset table %p", idx_table);
2419 		return (-1);
2420 	}
2421 
2422 	return (DCMD_OK);
2423 }
2424 
2425 /*ARGSUSED*/
2426 static int
2427 sa_attr_print(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
2428 {
2429 	uint32_t *offset_tab;
2430 	int attr_count;
2431 	uint64_t attr_id;
2432 	uintptr_t attr_addr;
2433 	uintptr_t bonus_tab, spill_tab;
2434 	uintptr_t db_bonus, db_spill;
2435 	uintptr_t os, os_sa;
2436 	uintptr_t db_data;
2437 
2438 	if (argc != 1)
2439 		return (DCMD_USAGE);
2440 
2441 	if (argv[0].a_type == MDB_TYPE_STRING)
2442 		attr_id = mdb_strtoull(argv[0].a_un.a_str);
2443 	else
2444 		return (DCMD_USAGE);
2445 
2446 	if (GETMEMB(addr, struct sa_handle, sa_bonus_tab, bonus_tab) ||
2447 	    GETMEMB(addr, struct sa_handle, sa_spill_tab, spill_tab) ||
2448 	    GETMEMB(addr, struct sa_handle, sa_os, os) ||
2449 	    GETMEMB(addr, struct sa_handle, sa_bonus, db_bonus) ||
2450 	    GETMEMB(addr, struct sa_handle, sa_spill, db_spill)) {
2451 		mdb_printf("Can't find necessary information in sa_handle "
2452 		    "in sa_handle\n");
2453 		return (DCMD_ERR);
2454 	}
2455 
2456 	if (GETMEMB(os, struct objset, os_sa, os_sa)) {
2457 		mdb_printf("Can't find os_sa in objset\n");
2458 		return (DCMD_ERR);
2459 	}
2460 
2461 	if (GETMEMB(os_sa, struct sa_os, sa_num_attrs, attr_count)) {
2462 		mdb_printf("Can't find sa_num_attrs\n");
2463 		return (DCMD_ERR);
2464 	}
2465 
2466 	if (attr_id > attr_count) {
2467 		mdb_printf("attribute id number is out of range\n");
2468 		return (DCMD_ERR);
2469 	}
2470 
2471 	if (bonus_tab) {
2472 		if (sa_get_off_table(bonus_tab, &offset_tab,
2473 		    attr_count) == -1) {
2474 			return (DCMD_ERR);
2475 		}
2476 
2477 		if (GETMEMB(db_bonus, struct dmu_buf, db_data, db_data)) {
2478 			mdb_printf("can't find db_data in bonus dbuf\n");
2479 			return (DCMD_ERR);
2480 		}
2481 	}
2482 
2483 	if (bonus_tab && !TOC_ATTR_PRESENT(offset_tab[attr_id]) &&
2484 	    spill_tab == NULL) {
2485 		mdb_printf("Attribute does not exist\n");
2486 		return (DCMD_ERR);
2487 	} else if (!TOC_ATTR_PRESENT(offset_tab[attr_id]) && spill_tab) {
2488 		if (sa_get_off_table(spill_tab, &offset_tab,
2489 		    attr_count) == -1) {
2490 			return (DCMD_ERR);
2491 		}
2492 		if (GETMEMB(db_spill, struct dmu_buf, db_data, db_data)) {
2493 			mdb_printf("can't find db_data in spill dbuf\n");
2494 			return (DCMD_ERR);
2495 		}
2496 		if (!TOC_ATTR_PRESENT(offset_tab[attr_id])) {
2497 			mdb_printf("Attribute does not exist\n");
2498 			return (DCMD_ERR);
2499 		}
2500 	}
2501 	attr_addr = db_data + TOC_OFF(offset_tab[attr_id]);
2502 	mdb_printf("%p\n", attr_addr);
2503 	return (DCMD_OK);
2504 }
2505 
2506 /* ARGSUSED */
2507 static int
2508 zfs_ace_print_common(uintptr_t addr, uint_t flags,
2509     uint64_t id, uint32_t access_mask, uint16_t ace_flags,
2510     uint16_t ace_type, int verbose)
2511 {
2512 	if (DCMD_HDRSPEC(flags) && !verbose)
2513 		mdb_printf("%<u>%-?s %-8s %-8s %-8s %s%</u>\n",
2514 		    "ADDR", "FLAGS", "MASK", "TYPE", "ID");
2515 
2516 	if (!verbose) {
2517 		mdb_printf("%0?p %-8x %-8x %-8x %-llx\n", addr,
2518 		    ace_flags, access_mask, ace_type, id);
2519 		return (DCMD_OK);
2520 	}
2521 
2522 	switch (ace_flags & ACE_TYPE_FLAGS) {
2523 	case ACE_OWNER:
2524 		mdb_printf("owner@:");
2525 		break;
2526 	case (ACE_IDENTIFIER_GROUP | ACE_GROUP):
2527 		mdb_printf("group@:");
2528 		break;
2529 	case ACE_EVERYONE:
2530 		mdb_printf("everyone@:");
2531 		break;
2532 	case ACE_IDENTIFIER_GROUP:
2533 		mdb_printf("group:%llx:", (u_longlong_t)id);
2534 		break;
2535 	case 0: /* User entry */
2536 		mdb_printf("user:%llx:", (u_longlong_t)id);
2537 		break;
2538 	}
2539 
2540 	/* print out permission mask */
2541 	if (access_mask & ACE_READ_DATA)
2542 		mdb_printf("r");
2543 	else
2544 		mdb_printf("-");
2545 	if (access_mask & ACE_WRITE_DATA)
2546 		mdb_printf("w");
2547 	else
2548 		mdb_printf("-");
2549 	if (access_mask & ACE_EXECUTE)
2550 		mdb_printf("x");
2551 	else
2552 		mdb_printf("-");
2553 	if (access_mask & ACE_APPEND_DATA)
2554 		mdb_printf("p");
2555 	else
2556 		mdb_printf("-");
2557 	if (access_mask & ACE_DELETE)
2558 		mdb_printf("d");
2559 	else
2560 		mdb_printf("-");
2561 	if (access_mask & ACE_DELETE_CHILD)
2562 		mdb_printf("D");
2563 	else
2564 		mdb_printf("-");
2565 	if (access_mask & ACE_READ_ATTRIBUTES)
2566 		mdb_printf("a");
2567 	else
2568 		mdb_printf("-");
2569 	if (access_mask & ACE_WRITE_ATTRIBUTES)
2570 		mdb_printf("A");
2571 	else
2572 		mdb_printf("-");
2573 	if (access_mask & ACE_READ_NAMED_ATTRS)
2574 		mdb_printf("R");
2575 	else
2576 		mdb_printf("-");
2577 	if (access_mask & ACE_WRITE_NAMED_ATTRS)
2578 		mdb_printf("W");
2579 	else
2580 		mdb_printf("-");
2581 	if (access_mask & ACE_READ_ACL)
2582 		mdb_printf("c");
2583 	else
2584 		mdb_printf("-");
2585 	if (access_mask & ACE_WRITE_ACL)
2586 		mdb_printf("C");
2587 	else
2588 		mdb_printf("-");
2589 	if (access_mask & ACE_WRITE_OWNER)
2590 		mdb_printf("o");
2591 	else
2592 		mdb_printf("-");
2593 	if (access_mask & ACE_SYNCHRONIZE)
2594 		mdb_printf("s");
2595 	else
2596 		mdb_printf("-");
2597 
2598 	mdb_printf(":");
2599 
2600 	/* Print out inheritance flags */
2601 	if (ace_flags & ACE_FILE_INHERIT_ACE)
2602 		mdb_printf("f");
2603 	else
2604 		mdb_printf("-");
2605 	if (ace_flags & ACE_DIRECTORY_INHERIT_ACE)
2606 		mdb_printf("d");
2607 	else
2608 		mdb_printf("-");
2609 	if (ace_flags & ACE_INHERIT_ONLY_ACE)
2610 		mdb_printf("i");
2611 	else
2612 		mdb_printf("-");
2613 	if (ace_flags & ACE_NO_PROPAGATE_INHERIT_ACE)
2614 		mdb_printf("n");
2615 	else
2616 		mdb_printf("-");
2617 	if (ace_flags & ACE_SUCCESSFUL_ACCESS_ACE_FLAG)
2618 		mdb_printf("S");
2619 	else
2620 		mdb_printf("-");
2621 	if (ace_flags & ACE_FAILED_ACCESS_ACE_FLAG)
2622 		mdb_printf("F");
2623 	else
2624 		mdb_printf("-");
2625 	if (ace_flags & ACE_INHERITED_ACE)
2626 		mdb_printf("I");
2627 	else
2628 		mdb_printf("-");
2629 
2630 	switch (ace_type) {
2631 	case ACE_ACCESS_ALLOWED_ACE_TYPE:
2632 		mdb_printf(":allow\n");
2633 		break;
2634 	case ACE_ACCESS_DENIED_ACE_TYPE:
2635 		mdb_printf(":deny\n");
2636 		break;
2637 	case ACE_SYSTEM_AUDIT_ACE_TYPE:
2638 		mdb_printf(":audit\n");
2639 		break;
2640 	case ACE_SYSTEM_ALARM_ACE_TYPE:
2641 		mdb_printf(":alarm\n");
2642 		break;
2643 	default:
2644 		mdb_printf(":?\n");
2645 	}
2646 	return (DCMD_OK);
2647 }
2648 
2649 /* ARGSUSED */
2650 static int
2651 zfs_ace_print(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
2652 {
2653 	zfs_ace_t zace;
2654 	int verbose = FALSE;
2655 	uint64_t id;
2656 
2657 	if (!(flags & DCMD_ADDRSPEC))
2658 		return (DCMD_USAGE);
2659 
2660 	if (mdb_getopts(argc, argv,
2661 	    'v', MDB_OPT_SETBITS, TRUE, &verbose, TRUE, NULL) != argc)
2662 		return (DCMD_USAGE);
2663 
2664 	if (mdb_vread(&zace, sizeof (zfs_ace_t), addr) == -1) {
2665 		mdb_warn("failed to read zfs_ace_t");
2666 		return (DCMD_ERR);
2667 	}
2668 
2669 	if ((zace.z_hdr.z_flags & ACE_TYPE_FLAGS) == 0 ||
2670 	    (zace.z_hdr.z_flags & ACE_TYPE_FLAGS) == ACE_IDENTIFIER_GROUP)
2671 		id = zace.z_fuid;
2672 	else
2673 		id = -1;
2674 
2675 	return (zfs_ace_print_common(addr, flags, id, zace.z_hdr.z_access_mask,
2676 	    zace.z_hdr.z_flags, zace.z_hdr.z_type, verbose));
2677 }
2678 
2679 /* ARGSUSED */
2680 static int
2681 zfs_ace0_print(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
2682 {
2683 	ace_t ace;
2684 	uint64_t id;
2685 	int verbose = FALSE;
2686 
2687 	if (!(flags & DCMD_ADDRSPEC))
2688 		return (DCMD_USAGE);
2689 
2690 	if (mdb_getopts(argc, argv,
2691 	    'v', MDB_OPT_SETBITS, TRUE, &verbose, TRUE, NULL) != argc)
2692 		return (DCMD_USAGE);
2693 
2694 	if (mdb_vread(&ace, sizeof (ace_t), addr) == -1) {
2695 		mdb_warn("failed to read ace_t");
2696 		return (DCMD_ERR);
2697 	}
2698 
2699 	if ((ace.a_flags & ACE_TYPE_FLAGS) == 0 ||
2700 	    (ace.a_flags & ACE_TYPE_FLAGS) == ACE_IDENTIFIER_GROUP)
2701 		id = ace.a_who;
2702 	else
2703 		id = -1;
2704 
2705 	return (zfs_ace_print_common(addr, flags, id, ace.a_access_mask,
2706 	    ace.a_flags, ace.a_type, verbose));
2707 }
2708 
2709 typedef struct acl_dump_args {
2710 	int a_argc;
2711 	const mdb_arg_t *a_argv;
2712 	uint16_t a_version;
2713 	int a_flags;
2714 } acl_dump_args_t;
2715 
2716 /* ARGSUSED */
2717 static int
2718 acl_aces_cb(uintptr_t addr, const void *unknown, void *arg)
2719 {
2720 	acl_dump_args_t *acl_args = (acl_dump_args_t *)arg;
2721 
2722 	if (acl_args->a_version == 1) {
2723 		if (mdb_call_dcmd("zfs_ace", addr,
2724 		    DCMD_ADDRSPEC|acl_args->a_flags, acl_args->a_argc,
2725 		    acl_args->a_argv) != DCMD_OK) {
2726 			return (WALK_ERR);
2727 		}
2728 	} else {
2729 		if (mdb_call_dcmd("zfs_ace0", addr,
2730 		    DCMD_ADDRSPEC|acl_args->a_flags, acl_args->a_argc,
2731 		    acl_args->a_argv) != DCMD_OK) {
2732 			return (WALK_ERR);
2733 		}
2734 	}
2735 	acl_args->a_flags = DCMD_LOOP;
2736 	return (WALK_NEXT);
2737 }
2738 
2739 /* ARGSUSED */
2740 static int
2741 acl_cb(uintptr_t addr, const void *unknown, void *arg)
2742 {
2743 	acl_dump_args_t *acl_args = (acl_dump_args_t *)arg;
2744 
2745 	if (acl_args->a_version == 1) {
2746 		if (mdb_pwalk("zfs_acl_node_aces", acl_aces_cb,
2747 		    arg, addr) != 0) {
2748 			mdb_warn("can't walk ACEs");
2749 			return (DCMD_ERR);
2750 		}
2751 	} else {
2752 		if (mdb_pwalk("zfs_acl_node_aces0", acl_aces_cb,
2753 		    arg, addr) != 0) {
2754 			mdb_warn("can't walk ACEs");
2755 			return (DCMD_ERR);
2756 		}
2757 	}
2758 	return (WALK_NEXT);
2759 }
2760 
2761 /* ARGSUSED */
2762 static int
2763 zfs_acl_dump(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
2764 {
2765 	zfs_acl_t zacl;
2766 	int verbose = FALSE;
2767 	acl_dump_args_t acl_args;
2768 
2769 	if (!(flags & DCMD_ADDRSPEC))
2770 		return (DCMD_USAGE);
2771 
2772 	if (mdb_getopts(argc, argv,
2773 	    'v', MDB_OPT_SETBITS, TRUE, &verbose, TRUE, NULL) != argc)
2774 		return (DCMD_USAGE);
2775 
2776 	if (mdb_vread(&zacl, sizeof (zfs_acl_t), addr) == -1) {
2777 		mdb_warn("failed to read zfs_acl_t");
2778 		return (DCMD_ERR);
2779 	}
2780 
2781 	acl_args.a_argc = argc;
2782 	acl_args.a_argv = argv;
2783 	acl_args.a_version = zacl.z_version;
2784 	acl_args.a_flags = DCMD_LOOPFIRST;
2785 
2786 	if (mdb_pwalk("zfs_acl_node", acl_cb, &acl_args, addr) != 0) {
2787 		mdb_warn("can't walk ACL");
2788 		return (DCMD_ERR);
2789 	}
2790 
2791 	return (DCMD_OK);
2792 }
2793 
2794 /* ARGSUSED */
2795 static int
2796 zfs_acl_node_walk_init(mdb_walk_state_t *wsp)
2797 {
2798 	if (wsp->walk_addr == NULL) {
2799 		mdb_warn("must supply address of zfs_acl_node_t\n");
2800 		return (WALK_ERR);
2801 	}
2802 
2803 	wsp->walk_addr += OFFSETOF(zfs_acl_t, z_acl);
2804 
2805 	if (mdb_layered_walk("list", wsp) == -1) {
2806 		mdb_warn("failed to walk 'list'\n");
2807 		return (WALK_ERR);
2808 	}
2809 
2810 	return (WALK_NEXT);
2811 }
2812 
2813 static int
2814 zfs_acl_node_walk_step(mdb_walk_state_t *wsp)
2815 {
2816 	zfs_acl_node_t	aclnode;
2817 
2818 	if (mdb_vread(&aclnode, sizeof (zfs_acl_node_t),
2819 	    wsp->walk_addr) == -1) {
2820 		mdb_warn("failed to read zfs_acl_node at %p", wsp->walk_addr);
2821 		return (WALK_ERR);
2822 	}
2823 
2824 	return (wsp->walk_callback(wsp->walk_addr, &aclnode, wsp->walk_cbdata));
2825 }
2826 
2827 typedef struct ace_walk_data {
2828 	int		ace_count;
2829 	int		ace_version;
2830 } ace_walk_data_t;
2831 
2832 static int
2833 zfs_aces_walk_init_common(mdb_walk_state_t *wsp, int version,
2834     int ace_count, uintptr_t ace_data)
2835 {
2836 	ace_walk_data_t *ace_walk_data;
2837 
2838 	if (wsp->walk_addr == NULL) {
2839 		mdb_warn("must supply address of zfs_acl_node_t\n");
2840 		return (WALK_ERR);
2841 	}
2842 
2843 	ace_walk_data = mdb_alloc(sizeof (ace_walk_data_t), UM_SLEEP | UM_GC);
2844 
2845 	ace_walk_data->ace_count = ace_count;
2846 	ace_walk_data->ace_version = version;
2847 
2848 	wsp->walk_addr = ace_data;
2849 	wsp->walk_data = ace_walk_data;
2850 
2851 	return (WALK_NEXT);
2852 }
2853 
2854 static int
2855 zfs_acl_node_aces_walk_init_common(mdb_walk_state_t *wsp, int version)
2856 {
2857 	static int gotid;
2858 	static mdb_ctf_id_t acl_id;
2859 	int z_ace_count;
2860 	uintptr_t z_acldata;
2861 
2862 	if (!gotid) {
2863 		if (mdb_ctf_lookup_by_name("struct zfs_acl_node",
2864 		    &acl_id) == -1) {
2865 			mdb_warn("couldn't find struct zfs_acl_node");
2866 			return (DCMD_ERR);
2867 		}
2868 		gotid = TRUE;
2869 	}
2870 
2871 	if (GETMEMBID(wsp->walk_addr, &acl_id, z_ace_count, z_ace_count)) {
2872 		return (DCMD_ERR);
2873 	}
2874 	if (GETMEMBID(wsp->walk_addr, &acl_id, z_acldata, z_acldata)) {
2875 		return (DCMD_ERR);
2876 	}
2877 
2878 	return (zfs_aces_walk_init_common(wsp, version,
2879 	    z_ace_count, z_acldata));
2880 }
2881 
2882 /* ARGSUSED */
2883 static int
2884 zfs_acl_node_aces_walk_init(mdb_walk_state_t *wsp)
2885 {
2886 	return (zfs_acl_node_aces_walk_init_common(wsp, 1));
2887 }
2888 
2889 /* ARGSUSED */
2890 static int
2891 zfs_acl_node_aces0_walk_init(mdb_walk_state_t *wsp)
2892 {
2893 	return (zfs_acl_node_aces_walk_init_common(wsp, 0));
2894 }
2895 
2896 static int
2897 zfs_aces_walk_step(mdb_walk_state_t *wsp)
2898 {
2899 	ace_walk_data_t *ace_data = wsp->walk_data;
2900 	zfs_ace_t zace;
2901 	ace_t *acep;
2902 	int status;
2903 	int entry_type;
2904 	int allow_type;
2905 	uintptr_t ptr;
2906 
2907 	if (ace_data->ace_count == 0)
2908 		return (WALK_DONE);
2909 
2910 	if (mdb_vread(&zace, sizeof (zfs_ace_t), wsp->walk_addr) == -1) {
2911 		mdb_warn("failed to read zfs_ace_t at %#lx",
2912 		    wsp->walk_addr);
2913 		return (WALK_ERR);
2914 	}
2915 
2916 	switch (ace_data->ace_version) {
2917 	case 0:
2918 		acep = (ace_t *)&zace;
2919 		entry_type = acep->a_flags & ACE_TYPE_FLAGS;
2920 		allow_type = acep->a_type;
2921 		break;
2922 	case 1:
2923 		entry_type = zace.z_hdr.z_flags & ACE_TYPE_FLAGS;
2924 		allow_type = zace.z_hdr.z_type;
2925 		break;
2926 	default:
2927 		return (WALK_ERR);
2928 	}
2929 
2930 	ptr = (uintptr_t)wsp->walk_addr;
2931 	switch (entry_type) {
2932 	case ACE_OWNER:
2933 	case ACE_EVERYONE:
2934 	case (ACE_IDENTIFIER_GROUP | ACE_GROUP):
2935 		ptr += ace_data->ace_version == 0 ?
2936 		    sizeof (ace_t) : sizeof (zfs_ace_hdr_t);
2937 		break;
2938 	case ACE_IDENTIFIER_GROUP:
2939 	default:
2940 		switch (allow_type) {
2941 		case ACE_ACCESS_ALLOWED_OBJECT_ACE_TYPE:
2942 		case ACE_ACCESS_DENIED_OBJECT_ACE_TYPE:
2943 		case ACE_SYSTEM_AUDIT_OBJECT_ACE_TYPE:
2944 		case ACE_SYSTEM_ALARM_OBJECT_ACE_TYPE:
2945 			ptr += ace_data->ace_version == 0 ?
2946 			    sizeof (ace_t) : sizeof (zfs_object_ace_t);
2947 			break;
2948 		default:
2949 			ptr += ace_data->ace_version == 0 ?
2950 			    sizeof (ace_t) : sizeof (zfs_ace_t);
2951 			break;
2952 		}
2953 	}
2954 
2955 	ace_data->ace_count--;
2956 	status = wsp->walk_callback(wsp->walk_addr,
2957 	    (void *)(uintptr_t)&zace, wsp->walk_cbdata);
2958 
2959 	wsp->walk_addr = ptr;
2960 	return (status);
2961 }
2962 
2963 /*
2964  * MDB module linkage information:
2965  *
2966  * We declare a list of structures describing our dcmds, and a function
2967  * named _mdb_init to return a pointer to our module information.
2968  */
2969 
2970 static const mdb_dcmd_t dcmds[] = {
2971 	{ "arc", "[-bkmg]", "print ARC variables", arc_print },
2972 	{ "blkptr", ":", "print blkptr_t", blkptr },
2973 	{ "dbuf", ":", "print dmu_buf_impl_t", dbuf },
2974 	{ "dbuf_stats", ":", "dbuf stats", dbuf_stats },
2975 	{ "dbufs",
2976 	    "\t[-O objset_t*] [-n objset_name | \"mos\"] "
2977 	    "[-o object | \"mdn\"] \n"
2978 	    "\t[-l level] [-b blkid | \"bonus\"]",
2979 	    "find dmu_buf_impl_t's that match specified criteria", dbufs },
2980 	{ "abuf_find", "dva_word[0] dva_word[1]",
2981 	    "find arc_buf_hdr_t of a specified DVA",
2982 	    abuf_find },
2983 	{ "spa", "?[-cv]", "spa_t summary", spa_print },
2984 	{ "spa_config", ":", "print spa_t configuration", spa_print_config },
2985 	{ "spa_verify", ":", "verify spa_t consistency", spa_verify },
2986 	{ "spa_space", ":[-b]", "print spa_t on-disk space usage", spa_space },
2987 	{ "spa_vdevs", ":", "given a spa_t, print vdev summary", spa_vdevs },
2988 	{ "vdev", ":[-re]\n"
2989 	    "\t-r display recursively\n"
2990 	    "\t-e print statistics",
2991 	    "vdev_t summary", vdev_print },
2992 	{ "zio", ":[cpr]\n"
2993 	    "\t-c display children\n"
2994 	    "\t-p display parents\n"
2995 	    "\t-r display recursively",
2996 	    "zio_t summary", zio_print },
2997 	{ "zio_state", "?", "print out all zio_t structures on system or "
2998 	    "for a particular pool", zio_state },
2999 	{ "zfs_blkstats", ":[-v]",
3000 	    "given a spa_t, print block type stats from last scrub",
3001 	    zfs_blkstats },
3002 	{ "zfs_params", "", "print zfs tunable parameters", zfs_params },
3003 	{ "refcount", "", "print refcount_t holders", refcount },
3004 	{ "zap_leaf", "", "print zap_leaf_phys_t", zap_leaf },
3005 	{ "zfs_aces", ":[-v]", "print all ACEs from a zfs_acl_t",
3006 	    zfs_acl_dump },
3007 	{ "zfs_ace", ":[-v]", "print zfs_ace", zfs_ace_print },
3008 	{ "zfs_ace0", ":[-v]", "print zfs_ace0", zfs_ace0_print },
3009 	{ "sa_attr_table", ":", "print SA attribute table from sa_os_t",
3010 	    sa_attr_table},
3011 	{ "sa_attr", ": attr_id",
3012 	    "print SA attribute address when given sa_handle_t", sa_attr_print},
3013 	{ "zfs_dbgmsg", ":[-v]",
3014 	    "print zfs debug log", dbgmsg},
3015 	{ NULL }
3016 };
3017 
3018 static const mdb_walker_t walkers[] = {
3019 	{ "zms_freelist", "walk ZFS metaslab freelist",
3020 		freelist_walk_init, freelist_walk_step, NULL },
3021 	{ "txg_list", "given any txg_list_t *, walk all entries in all txgs",
3022 		txg_list_walk_init, txg_list_walk_step, NULL },
3023 	{ "txg_list0", "given any txg_list_t *, walk all entries in txg 0",
3024 		txg_list0_walk_init, txg_list_walk_step, NULL },
3025 	{ "txg_list1", "given any txg_list_t *, walk all entries in txg 1",
3026 		txg_list1_walk_init, txg_list_walk_step, NULL },
3027 	{ "txg_list2", "given any txg_list_t *, walk all entries in txg 2",
3028 		txg_list2_walk_init, txg_list_walk_step, NULL },
3029 	{ "txg_list3", "given any txg_list_t *, walk all entries in txg 3",
3030 		txg_list3_walk_init, txg_list_walk_step, NULL },
3031 	{ "zio", "walk all zio structures, optionally for a particular spa_t",
3032 		zio_walk_init, zio_walk_step, NULL },
3033 	{ "zio_root", "walk all root zio_t structures, optionally for a "
3034 	    "particular spa_t",
3035 		zio_walk_init, zio_walk_root_step, NULL },
3036 	{ "spa", "walk all spa_t entries in the namespace",
3037 		spa_walk_init, spa_walk_step, NULL },
3038 	{ "metaslab", "given a spa_t *, walk all metaslab_t structures",
3039 		metaslab_walk_init, metaslab_walk_step, NULL },
3040 	{ "zfs_acl_node", "given a zfs_acl_t, walk all zfs_acl_nodes",
3041 	    zfs_acl_node_walk_init, zfs_acl_node_walk_step, NULL },
3042 	{ "zfs_acl_node_aces", "given a zfs_acl_node_t, walk all ACEs",
3043 	    zfs_acl_node_aces_walk_init, zfs_aces_walk_step, NULL },
3044 	{ "zfs_acl_node_aces0",
3045 	    "given a zfs_acl_node_t, walk all ACEs as ace_t",
3046 	    zfs_acl_node_aces0_walk_init, zfs_aces_walk_step, NULL },
3047 	{ NULL }
3048 };
3049 
3050 static const mdb_modinfo_t modinfo = {
3051 	MDB_API_VERSION, dcmds, walkers
3052 };
3053 
3054 const mdb_modinfo_t *
3055 _mdb_init(void)
3056 {
3057 	return (&modinfo);
3058 }
3059