xref: /illumos-gate/usr/src/cmd/mdb/common/modules/zfs/zfs.c (revision 5cabbc6b49070407fb9610cfe73d4c0e0dea3e77)
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  * Copyright (c) 2011, 2016 by Delphix. All rights reserved.
25  * Copyright (c) 2017, Joyent, Inc.  All rights reserved.
26  */
27 
28 /* Portions Copyright 2010 Robert Milkowski */
29 
30 #include <mdb/mdb_ctf.h>
31 #include <sys/zfs_context.h>
32 #include <sys/mdb_modapi.h>
33 #include <sys/dbuf.h>
34 #include <sys/dmu_objset.h>
35 #include <sys/dsl_dir.h>
36 #include <sys/dsl_pool.h>
37 #include <sys/metaslab_impl.h>
38 #include <sys/space_map.h>
39 #include <sys/list.h>
40 #include <sys/vdev_impl.h>
41 #include <sys/zap_leaf.h>
42 #include <sys/zap_impl.h>
43 #include <ctype.h>
44 #include <sys/zfs_acl.h>
45 #include <sys/sa_impl.h>
46 #include <sys/multilist.h>
47 
48 #ifdef _KERNEL
49 #define	ZFS_OBJ_NAME	"zfs"
50 extern int64_t mdb_gethrtime(void);
51 #else
52 #define	ZFS_OBJ_NAME	"libzpool.so.1"
53 #endif
54 
55 #define	ZFS_STRUCT	"struct " ZFS_OBJ_NAME "`"
56 
57 #ifndef _KERNEL
58 int aok;
59 #endif
60 
61 enum spa_flags {
62 	SPA_FLAG_CONFIG			= 1 << 0,
63 	SPA_FLAG_VDEVS			= 1 << 1,
64 	SPA_FLAG_ERRORS			= 1 << 2,
65 	SPA_FLAG_METASLAB_GROUPS	= 1 << 3,
66 	SPA_FLAG_METASLABS		= 1 << 4,
67 	SPA_FLAG_HISTOGRAMS		= 1 << 5
68 };
69 
70 /*
71  * If any of these flags are set, call spa_vdevs in spa_print
72  */
73 #define	SPA_FLAG_ALL_VDEV	\
74 	(SPA_FLAG_VDEVS | SPA_FLAG_ERRORS | SPA_FLAG_METASLAB_GROUPS | \
75 	SPA_FLAG_METASLABS)
76 
77 static int
78 getmember(uintptr_t addr, const char *type, mdb_ctf_id_t *idp,
79     const char *member, int len, void *buf)
80 {
81 	mdb_ctf_id_t id;
82 	ulong_t off;
83 	char name[64];
84 
85 	if (idp == NULL) {
86 		if (mdb_ctf_lookup_by_name(type, &id) == -1) {
87 			mdb_warn("couldn't find type %s", type);
88 			return (DCMD_ERR);
89 		}
90 		idp = &id;
91 	} else {
92 		type = name;
93 		mdb_ctf_type_name(*idp, name, sizeof (name));
94 	}
95 
96 	if (mdb_ctf_offsetof(*idp, member, &off) == -1) {
97 		mdb_warn("couldn't find member %s of type %s\n", member, type);
98 		return (DCMD_ERR);
99 	}
100 	if (off % 8 != 0) {
101 		mdb_warn("member %s of type %s is unsupported bitfield",
102 		    member, type);
103 		return (DCMD_ERR);
104 	}
105 	off /= 8;
106 
107 	if (mdb_vread(buf, len, addr + off) == -1) {
108 		mdb_warn("failed to read %s from %s at %p",
109 		    member, type, addr + off);
110 		return (DCMD_ERR);
111 	}
112 	/* mdb_warn("read %s from %s at %p+%llx\n", member, type, addr, off); */
113 
114 	return (0);
115 }
116 
117 #define	GETMEMB(addr, structname, member, dest) \
118 	getmember(addr, ZFS_STRUCT structname, NULL, #member, \
119 	sizeof (dest), &(dest))
120 
121 #define	GETMEMBID(addr, ctfid, member, dest) \
122 	getmember(addr, NULL, ctfid, #member, sizeof (dest), &(dest))
123 
124 static boolean_t
125 strisprint(const char *cp)
126 {
127 	for (; *cp; cp++) {
128 		if (!isprint(*cp))
129 			return (B_FALSE);
130 	}
131 	return (B_TRUE);
132 }
133 
134 #define	NICENUM_BUFLEN 6
135 
136 static int
137 snprintfrac(char *buf, int len,
138     uint64_t numerator, uint64_t denom, int frac_digits)
139 {
140 	int mul = 1;
141 	int whole, frac, i;
142 
143 	for (i = frac_digits; i; i--)
144 		mul *= 10;
145 	whole = numerator / denom;
146 	frac = mul * numerator / denom - mul * whole;
147 	return (mdb_snprintf(buf, len, "%u.%0*u", whole, frac_digits, frac));
148 }
149 
150 static void
151 mdb_nicenum(uint64_t num, char *buf)
152 {
153 	uint64_t n = num;
154 	int index = 0;
155 	char *u;
156 
157 	while (n >= 1024) {
158 		n = (n + (1024 / 2)) / 1024; /* Round up or down */
159 		index++;
160 	}
161 
162 	u = &" \0K\0M\0G\0T\0P\0E\0"[index*2];
163 
164 	if (index == 0) {
165 		(void) mdb_snprintf(buf, NICENUM_BUFLEN, "%llu",
166 		    (u_longlong_t)n);
167 	} else if (n < 10 && (num & (num - 1)) != 0) {
168 		(void) snprintfrac(buf, NICENUM_BUFLEN,
169 		    num, 1ULL << 10 * index, 2);
170 		strcat(buf, u);
171 	} else if (n < 100 && (num & (num - 1)) != 0) {
172 		(void) snprintfrac(buf, NICENUM_BUFLEN,
173 		    num, 1ULL << 10 * index, 1);
174 		strcat(buf, u);
175 	} else {
176 		(void) mdb_snprintf(buf, NICENUM_BUFLEN, "%llu%s",
177 		    (u_longlong_t)n, u);
178 	}
179 }
180 
181 static int verbose;
182 
183 static int
184 freelist_walk_init(mdb_walk_state_t *wsp)
185 {
186 	if (wsp->walk_addr == NULL) {
187 		mdb_warn("must supply starting address\n");
188 		return (WALK_ERR);
189 	}
190 
191 	wsp->walk_data = 0;  /* Index into the freelist */
192 	return (WALK_NEXT);
193 }
194 
195 static int
196 freelist_walk_step(mdb_walk_state_t *wsp)
197 {
198 	uint64_t entry;
199 	uintptr_t number = (uintptr_t)wsp->walk_data;
200 	char *ddata[] = { "ALLOC", "FREE", "CONDENSE", "INVALID",
201 			    "INVALID", "INVALID", "INVALID", "INVALID" };
202 	int mapshift = SPA_MINBLOCKSHIFT;
203 
204 	if (mdb_vread(&entry, sizeof (entry), wsp->walk_addr) == -1) {
205 		mdb_warn("failed to read freelist entry %p", wsp->walk_addr);
206 		return (WALK_DONE);
207 	}
208 	wsp->walk_addr += sizeof (entry);
209 	wsp->walk_data = (void *)(number + 1);
210 
211 	if (SM_DEBUG_DECODE(entry)) {
212 		mdb_printf("DEBUG: %3u  %10s: txg=%llu  pass=%llu\n",
213 		    number,
214 		    ddata[SM_DEBUG_ACTION_DECODE(entry)],
215 		    SM_DEBUG_TXG_DECODE(entry),
216 		    SM_DEBUG_SYNCPASS_DECODE(entry));
217 	} else {
218 		mdb_printf("Entry: %3u  offsets=%08llx-%08llx  type=%c  "
219 		    "size=%06llx", number,
220 		    SM_OFFSET_DECODE(entry) << mapshift,
221 		    (SM_OFFSET_DECODE(entry) + SM_RUN_DECODE(entry)) <<
222 		    mapshift,
223 		    SM_TYPE_DECODE(entry) == SM_ALLOC ? 'A' : 'F',
224 		    SM_RUN_DECODE(entry) << mapshift);
225 		if (verbose)
226 			mdb_printf("      (raw=%012llx)\n", entry);
227 		mdb_printf("\n");
228 	}
229 	return (WALK_NEXT);
230 }
231 
232 static int
233 mdb_dsl_dir_name(uintptr_t addr, char *buf)
234 {
235 	static int gotid;
236 	static mdb_ctf_id_t dd_id;
237 	uintptr_t dd_parent;
238 	char dd_myname[ZFS_MAX_DATASET_NAME_LEN];
239 
240 	if (!gotid) {
241 		if (mdb_ctf_lookup_by_name(ZFS_STRUCT "dsl_dir",
242 		    &dd_id) == -1) {
243 			mdb_warn("couldn't find struct dsl_dir");
244 			return (DCMD_ERR);
245 		}
246 		gotid = TRUE;
247 	}
248 	if (GETMEMBID(addr, &dd_id, dd_parent, dd_parent) ||
249 	    GETMEMBID(addr, &dd_id, dd_myname, dd_myname)) {
250 		return (DCMD_ERR);
251 	}
252 
253 	if (dd_parent) {
254 		if (mdb_dsl_dir_name(dd_parent, buf))
255 			return (DCMD_ERR);
256 		strcat(buf, "/");
257 	}
258 
259 	if (dd_myname[0])
260 		strcat(buf, dd_myname);
261 	else
262 		strcat(buf, "???");
263 
264 	return (0);
265 }
266 
267 static int
268 objset_name(uintptr_t addr, char *buf)
269 {
270 	static int gotid;
271 	static mdb_ctf_id_t os_id, ds_id;
272 	uintptr_t os_dsl_dataset;
273 	char ds_snapname[ZFS_MAX_DATASET_NAME_LEN];
274 	uintptr_t ds_dir;
275 
276 	buf[0] = '\0';
277 
278 	if (!gotid) {
279 		if (mdb_ctf_lookup_by_name(ZFS_STRUCT "objset",
280 		    &os_id) == -1) {
281 			mdb_warn("couldn't find struct objset");
282 			return (DCMD_ERR);
283 		}
284 		if (mdb_ctf_lookup_by_name(ZFS_STRUCT "dsl_dataset",
285 		    &ds_id) == -1) {
286 			mdb_warn("couldn't find struct dsl_dataset");
287 			return (DCMD_ERR);
288 		}
289 
290 		gotid = TRUE;
291 	}
292 
293 	if (GETMEMBID(addr, &os_id, os_dsl_dataset, os_dsl_dataset))
294 		return (DCMD_ERR);
295 
296 	if (os_dsl_dataset == 0) {
297 		strcat(buf, "mos");
298 		return (0);
299 	}
300 
301 	if (GETMEMBID(os_dsl_dataset, &ds_id, ds_snapname, ds_snapname) ||
302 	    GETMEMBID(os_dsl_dataset, &ds_id, ds_dir, ds_dir)) {
303 		return (DCMD_ERR);
304 	}
305 
306 	if (ds_dir && mdb_dsl_dir_name(ds_dir, buf))
307 		return (DCMD_ERR);
308 
309 	if (ds_snapname[0]) {
310 		strcat(buf, "@");
311 		strcat(buf, ds_snapname);
312 	}
313 	return (0);
314 }
315 
316 static int
317 enum_lookup(char *type, int val, const char *prefix, size_t size, char *out)
318 {
319 	const char *cp;
320 	size_t len = strlen(prefix);
321 	mdb_ctf_id_t enum_type;
322 
323 	if (mdb_ctf_lookup_by_name(type, &enum_type) != 0) {
324 		mdb_warn("Could not find enum for %s", type);
325 		return (-1);
326 	}
327 
328 	if ((cp = mdb_ctf_enum_name(enum_type, val)) != NULL) {
329 		if (strncmp(cp, prefix, len) == 0)
330 			cp += len;
331 		(void) strncpy(out, cp, size);
332 	} else {
333 		mdb_snprintf(out, size, "? (%d)", val);
334 	}
335 	return (0);
336 }
337 
338 /* ARGSUSED */
339 static int
340 zfs_params(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
341 {
342 	/*
343 	 * This table can be approximately generated by running:
344 	 * egrep "^[a-z0-9_]+ [a-z0-9_]+( =.*)?;" *.c | cut -d ' ' -f 2
345 	 */
346 	static const char *params[] = {
347 		"arc_reduce_dnlc_percent",
348 		"arc_lotsfree_percent",
349 		"zfs_dirty_data_max",
350 		"zfs_dirty_data_sync",
351 		"zfs_delay_max_ns",
352 		"zfs_delay_min_dirty_percent",
353 		"zfs_delay_scale",
354 		"zfs_vdev_max_active",
355 		"zfs_vdev_sync_read_min_active",
356 		"zfs_vdev_sync_read_max_active",
357 		"zfs_vdev_sync_write_min_active",
358 		"zfs_vdev_sync_write_max_active",
359 		"zfs_vdev_async_read_min_active",
360 		"zfs_vdev_async_read_max_active",
361 		"zfs_vdev_async_write_min_active",
362 		"zfs_vdev_async_write_max_active",
363 		"zfs_vdev_scrub_min_active",
364 		"zfs_vdev_scrub_max_active",
365 		"zfs_vdev_async_write_active_min_dirty_percent",
366 		"zfs_vdev_async_write_active_max_dirty_percent",
367 		"spa_asize_inflation",
368 		"zfs_arc_max",
369 		"zfs_arc_min",
370 		"arc_shrink_shift",
371 		"zfs_mdcomp_disable",
372 		"zfs_prefetch_disable",
373 		"zfetch_max_streams",
374 		"zfetch_min_sec_reap",
375 		"zfetch_block_cap",
376 		"zfetch_array_rd_sz",
377 		"zfs_default_bs",
378 		"zfs_default_ibs",
379 		"metaslab_aliquot",
380 		"reference_tracking_enable",
381 		"reference_history",
382 		"spa_max_replication_override",
383 		"spa_mode_global",
384 		"zfs_flags",
385 		"zfs_txg_timeout",
386 		"zfs_vdev_cache_max",
387 		"zfs_vdev_cache_size",
388 		"zfs_vdev_cache_bshift",
389 		"vdev_mirror_shift",
390 		"zfs_scrub_limit",
391 		"zfs_no_scrub_io",
392 		"zfs_no_scrub_prefetch",
393 		"zfs_vdev_aggregation_limit",
394 		"fzap_default_block_shift",
395 		"zfs_immediate_write_sz",
396 		"zfs_read_chunk_size",
397 		"zfs_nocacheflush",
398 		"zil_replay_disable",
399 		"metaslab_gang_bang",
400 		"metaslab_df_alloc_threshold",
401 		"metaslab_df_free_pct",
402 		"zio_injection_enabled",
403 		"zvol_immediate_write_sz",
404 	};
405 
406 	for (int i = 0; i < sizeof (params) / sizeof (params[0]); i++) {
407 		int sz;
408 		uint64_t val64;
409 		uint32_t *val32p = (uint32_t *)&val64;
410 
411 		sz = mdb_readvar(&val64, params[i]);
412 		if (sz == 4) {
413 			mdb_printf("%s = 0x%x\n", params[i], *val32p);
414 		} else if (sz == 8) {
415 			mdb_printf("%s = 0x%llx\n", params[i], val64);
416 		} else {
417 			mdb_warn("variable %s not found", params[i]);
418 		}
419 	}
420 
421 	return (DCMD_OK);
422 }
423 
424 /* ARGSUSED */
425 static int
426 dva(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
427 {
428 	dva_t dva;
429 	if (mdb_vread(&dva, sizeof (dva_t), addr) == -1) {
430 		mdb_warn("failed to read dva_t");
431 		return (DCMD_ERR);
432 	}
433 	mdb_printf("<%llu:%llx:%llx>\n",
434 	    (u_longlong_t)DVA_GET_VDEV(&dva),
435 	    (u_longlong_t)DVA_GET_OFFSET(&dva),
436 	    (u_longlong_t)DVA_GET_ASIZE(&dva));
437 
438 	return (DCMD_OK);
439 }
440 
441 /* ARGSUSED */
442 static int
443 blkptr(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
444 {
445 	char type[80], checksum[80], compress[80];
446 	blkptr_t blk, *bp = &blk;
447 	char buf[BP_SPRINTF_LEN];
448 
449 	if (mdb_vread(&blk, sizeof (blkptr_t), addr) == -1) {
450 		mdb_warn("failed to read blkptr_t");
451 		return (DCMD_ERR);
452 	}
453 
454 	if (enum_lookup("enum dmu_object_type", BP_GET_TYPE(bp), "DMU_OT_",
455 	    sizeof (type), type) == -1 ||
456 	    enum_lookup("enum zio_checksum", BP_GET_CHECKSUM(bp),
457 	    "ZIO_CHECKSUM_", sizeof (checksum), checksum) == -1 ||
458 	    enum_lookup("enum zio_compress", BP_GET_COMPRESS(bp),
459 	    "ZIO_COMPRESS_", sizeof (compress), compress) == -1) {
460 		mdb_warn("Could not find blkptr enumerated types");
461 		return (DCMD_ERR);
462 	}
463 
464 	SNPRINTF_BLKPTR(mdb_snprintf, '\n', buf, sizeof (buf), bp, type,
465 	    checksum, compress);
466 
467 	mdb_printf("%s\n", buf);
468 
469 	return (DCMD_OK);
470 }
471 
472 typedef struct mdb_dmu_buf_impl {
473 	struct {
474 		uint64_t db_object;
475 		uintptr_t db_data;
476 	} db;
477 	uintptr_t db_objset;
478 	uint64_t db_level;
479 	uint64_t db_blkid;
480 	struct {
481 		uint64_t rc_count;
482 	} db_holds;
483 } mdb_dmu_buf_impl_t;
484 
485 /* ARGSUSED */
486 static int
487 dbuf(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
488 {
489 	mdb_dmu_buf_impl_t db;
490 	char objectname[32];
491 	char blkidname[32];
492 	char path[ZFS_MAX_DATASET_NAME_LEN];
493 	int ptr_width = (int)(sizeof (void *)) * 2;
494 
495 	if (DCMD_HDRSPEC(flags))
496 		mdb_printf("%*s %8s %3s %9s %5s %s\n",
497 		    ptr_width, "addr", "object", "lvl", "blkid", "holds", "os");
498 
499 	if (mdb_ctf_vread(&db, ZFS_STRUCT "dmu_buf_impl", "mdb_dmu_buf_impl_t",
500 	    addr, 0) == -1)
501 		return (DCMD_ERR);
502 
503 	if (db.db.db_object == DMU_META_DNODE_OBJECT)
504 		(void) strcpy(objectname, "mdn");
505 	else
506 		(void) mdb_snprintf(objectname, sizeof (objectname), "%llx",
507 		    (u_longlong_t)db.db.db_object);
508 
509 	if (db.db_blkid == DMU_BONUS_BLKID)
510 		(void) strcpy(blkidname, "bonus");
511 	else
512 		(void) mdb_snprintf(blkidname, sizeof (blkidname), "%llx",
513 		    (u_longlong_t)db.db_blkid);
514 
515 	if (objset_name(db.db_objset, path)) {
516 		return (DCMD_ERR);
517 	}
518 
519 	mdb_printf("%*p %8s %3u %9s %5llu %s\n", ptr_width, addr,
520 	    objectname, (int)db.db_level, blkidname,
521 	    db.db_holds.rc_count, path);
522 
523 	return (DCMD_OK);
524 }
525 
526 /* ARGSUSED */
527 static int
528 dbuf_stats(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
529 {
530 #define	HISTOSZ 32
531 	uintptr_t dbp;
532 	dmu_buf_impl_t db;
533 	dbuf_hash_table_t ht;
534 	uint64_t bucket, ndbufs;
535 	uint64_t histo[HISTOSZ];
536 	uint64_t histo2[HISTOSZ];
537 	int i, maxidx;
538 
539 	if (mdb_readvar(&ht, "dbuf_hash_table") == -1) {
540 		mdb_warn("failed to read 'dbuf_hash_table'");
541 		return (DCMD_ERR);
542 	}
543 
544 	for (i = 0; i < HISTOSZ; i++) {
545 		histo[i] = 0;
546 		histo2[i] = 0;
547 	}
548 
549 	ndbufs = 0;
550 	for (bucket = 0; bucket < ht.hash_table_mask+1; bucket++) {
551 		int len;
552 
553 		if (mdb_vread(&dbp, sizeof (void *),
554 		    (uintptr_t)(ht.hash_table+bucket)) == -1) {
555 			mdb_warn("failed to read hash bucket %u at %p",
556 			    bucket, ht.hash_table+bucket);
557 			return (DCMD_ERR);
558 		}
559 
560 		len = 0;
561 		while (dbp != 0) {
562 			if (mdb_vread(&db, sizeof (dmu_buf_impl_t),
563 			    dbp) == -1) {
564 				mdb_warn("failed to read dbuf at %p", dbp);
565 				return (DCMD_ERR);
566 			}
567 			dbp = (uintptr_t)db.db_hash_next;
568 			for (i = MIN(len, HISTOSZ - 1); i >= 0; i--)
569 				histo2[i]++;
570 			len++;
571 			ndbufs++;
572 		}
573 
574 		if (len >= HISTOSZ)
575 			len = HISTOSZ-1;
576 		histo[len]++;
577 	}
578 
579 	mdb_printf("hash table has %llu buckets, %llu dbufs "
580 	    "(avg %llu buckets/dbuf)\n",
581 	    ht.hash_table_mask+1, ndbufs,
582 	    (ht.hash_table_mask+1)/ndbufs);
583 
584 	mdb_printf("\n");
585 	maxidx = 0;
586 	for (i = 0; i < HISTOSZ; i++)
587 		if (histo[i] > 0)
588 			maxidx = i;
589 	mdb_printf("hash chain length	number of buckets\n");
590 	for (i = 0; i <= maxidx; i++)
591 		mdb_printf("%u			%llu\n", i, histo[i]);
592 
593 	mdb_printf("\n");
594 	maxidx = 0;
595 	for (i = 0; i < HISTOSZ; i++)
596 		if (histo2[i] > 0)
597 			maxidx = i;
598 	mdb_printf("hash chain depth	number of dbufs\n");
599 	for (i = 0; i <= maxidx; i++)
600 		mdb_printf("%u or more		%llu	%llu%%\n",
601 		    i, histo2[i], histo2[i]*100/ndbufs);
602 
603 
604 	return (DCMD_OK);
605 }
606 
607 #define	CHAIN_END 0xffff
608 /*
609  * ::zap_leaf [-v]
610  *
611  * Print a zap_leaf_phys_t, assumed to be 16k
612  */
613 /* ARGSUSED */
614 static int
615 zap_leaf(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
616 {
617 	char buf[16*1024];
618 	int verbose = B_FALSE;
619 	int four = B_FALSE;
620 	dmu_buf_t l_dbuf;
621 	zap_leaf_t l;
622 	zap_leaf_phys_t *zlp = (void *)buf;
623 	int i;
624 
625 	if (mdb_getopts(argc, argv,
626 	    'v', MDB_OPT_SETBITS, TRUE, &verbose,
627 	    '4', MDB_OPT_SETBITS, TRUE, &four,
628 	    NULL) != argc)
629 		return (DCMD_USAGE);
630 
631 	l_dbuf.db_data = zlp;
632 	l.l_dbuf = &l_dbuf;
633 	l.l_bs = 14; /* assume 16k blocks */
634 	if (four)
635 		l.l_bs = 12;
636 
637 	if (!(flags & DCMD_ADDRSPEC)) {
638 		return (DCMD_USAGE);
639 	}
640 
641 	if (mdb_vread(buf, sizeof (buf), addr) == -1) {
642 		mdb_warn("failed to read zap_leaf_phys_t at %p", addr);
643 		return (DCMD_ERR);
644 	}
645 
646 	if (zlp->l_hdr.lh_block_type != ZBT_LEAF ||
647 	    zlp->l_hdr.lh_magic != ZAP_LEAF_MAGIC) {
648 		mdb_warn("This does not appear to be a zap_leaf_phys_t");
649 		return (DCMD_ERR);
650 	}
651 
652 	mdb_printf("zap_leaf_phys_t at %p:\n", addr);
653 	mdb_printf("    lh_prefix_len = %u\n", zlp->l_hdr.lh_prefix_len);
654 	mdb_printf("    lh_prefix = %llx\n", zlp->l_hdr.lh_prefix);
655 	mdb_printf("    lh_nentries = %u\n", zlp->l_hdr.lh_nentries);
656 	mdb_printf("    lh_nfree = %u\n", zlp->l_hdr.lh_nfree,
657 	    zlp->l_hdr.lh_nfree * 100 / (ZAP_LEAF_NUMCHUNKS(&l)));
658 	mdb_printf("    lh_freelist = %u\n", zlp->l_hdr.lh_freelist);
659 	mdb_printf("    lh_flags = %x (%s)\n", zlp->l_hdr.lh_flags,
660 	    zlp->l_hdr.lh_flags & ZLF_ENTRIES_CDSORTED ?
661 	    "ENTRIES_CDSORTED" : "");
662 
663 	if (verbose) {
664 		mdb_printf(" hash table:\n");
665 		for (i = 0; i < ZAP_LEAF_HASH_NUMENTRIES(&l); i++) {
666 			if (zlp->l_hash[i] != CHAIN_END)
667 				mdb_printf("    %u: %u\n", i, zlp->l_hash[i]);
668 		}
669 	}
670 
671 	mdb_printf(" chunks:\n");
672 	for (i = 0; i < ZAP_LEAF_NUMCHUNKS(&l); i++) {
673 		/* LINTED: alignment */
674 		zap_leaf_chunk_t *zlc = &ZAP_LEAF_CHUNK(&l, i);
675 		switch (zlc->l_entry.le_type) {
676 		case ZAP_CHUNK_FREE:
677 			if (verbose) {
678 				mdb_printf("    %u: free; lf_next = %u\n",
679 				    i, zlc->l_free.lf_next);
680 			}
681 			break;
682 		case ZAP_CHUNK_ENTRY:
683 			mdb_printf("    %u: entry\n", i);
684 			if (verbose) {
685 				mdb_printf("        le_next = %u\n",
686 				    zlc->l_entry.le_next);
687 			}
688 			mdb_printf("        le_name_chunk = %u\n",
689 			    zlc->l_entry.le_name_chunk);
690 			mdb_printf("        le_name_numints = %u\n",
691 			    zlc->l_entry.le_name_numints);
692 			mdb_printf("        le_value_chunk = %u\n",
693 			    zlc->l_entry.le_value_chunk);
694 			mdb_printf("        le_value_intlen = %u\n",
695 			    zlc->l_entry.le_value_intlen);
696 			mdb_printf("        le_value_numints = %u\n",
697 			    zlc->l_entry.le_value_numints);
698 			mdb_printf("        le_cd = %u\n",
699 			    zlc->l_entry.le_cd);
700 			mdb_printf("        le_hash = %llx\n",
701 			    zlc->l_entry.le_hash);
702 			break;
703 		case ZAP_CHUNK_ARRAY:
704 			mdb_printf("    %u: array", i);
705 			if (strisprint((char *)zlc->l_array.la_array))
706 				mdb_printf(" \"%s\"", zlc->l_array.la_array);
707 			mdb_printf("\n");
708 			if (verbose) {
709 				int j;
710 				mdb_printf("        ");
711 				for (j = 0; j < ZAP_LEAF_ARRAY_BYTES; j++) {
712 					mdb_printf("%02x ",
713 					    zlc->l_array.la_array[j]);
714 				}
715 				mdb_printf("\n");
716 			}
717 			if (zlc->l_array.la_next != CHAIN_END) {
718 				mdb_printf("        lf_next = %u\n",
719 				    zlc->l_array.la_next);
720 			}
721 			break;
722 		default:
723 			mdb_printf("    %u: undefined type %u\n",
724 			    zlc->l_entry.le_type);
725 		}
726 	}
727 
728 	return (DCMD_OK);
729 }
730 
731 typedef struct dbufs_data {
732 	mdb_ctf_id_t id;
733 	uint64_t objset;
734 	uint64_t object;
735 	uint64_t level;
736 	uint64_t blkid;
737 	char *osname;
738 } dbufs_data_t;
739 
740 #define	DBUFS_UNSET	(0xbaddcafedeadbeefULL)
741 
742 /* ARGSUSED */
743 static int
744 dbufs_cb(uintptr_t addr, const void *unknown, void *arg)
745 {
746 	dbufs_data_t *data = arg;
747 	uintptr_t objset;
748 	dmu_buf_t db;
749 	uint8_t level;
750 	uint64_t blkid;
751 	char osname[ZFS_MAX_DATASET_NAME_LEN];
752 
753 	if (GETMEMBID(addr, &data->id, db_objset, objset) ||
754 	    GETMEMBID(addr, &data->id, db, db) ||
755 	    GETMEMBID(addr, &data->id, db_level, level) ||
756 	    GETMEMBID(addr, &data->id, db_blkid, blkid)) {
757 		return (WALK_ERR);
758 	}
759 
760 	if ((data->objset == DBUFS_UNSET || data->objset == objset) &&
761 	    (data->osname == NULL || (objset_name(objset, osname) == 0 &&
762 	    strcmp(data->osname, osname) == 0)) &&
763 	    (data->object == DBUFS_UNSET || data->object == db.db_object) &&
764 	    (data->level == DBUFS_UNSET || data->level == level) &&
765 	    (data->blkid == DBUFS_UNSET || data->blkid == blkid)) {
766 		mdb_printf("%#lr\n", addr);
767 	}
768 	return (WALK_NEXT);
769 }
770 
771 /* ARGSUSED */
772 static int
773 dbufs(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
774 {
775 	dbufs_data_t data;
776 	char *object = NULL;
777 	char *blkid = NULL;
778 
779 	data.objset = data.object = data.level = data.blkid = DBUFS_UNSET;
780 	data.osname = NULL;
781 
782 	if (mdb_getopts(argc, argv,
783 	    'O', MDB_OPT_UINT64, &data.objset,
784 	    'n', MDB_OPT_STR, &data.osname,
785 	    'o', MDB_OPT_STR, &object,
786 	    'l', MDB_OPT_UINT64, &data.level,
787 	    'b', MDB_OPT_STR, &blkid) != argc) {
788 		return (DCMD_USAGE);
789 	}
790 
791 	if (object) {
792 		if (strcmp(object, "mdn") == 0) {
793 			data.object = DMU_META_DNODE_OBJECT;
794 		} else {
795 			data.object = mdb_strtoull(object);
796 		}
797 	}
798 
799 	if (blkid) {
800 		if (strcmp(blkid, "bonus") == 0) {
801 			data.blkid = DMU_BONUS_BLKID;
802 		} else {
803 			data.blkid = mdb_strtoull(blkid);
804 		}
805 	}
806 
807 	if (mdb_ctf_lookup_by_name(ZFS_STRUCT "dmu_buf_impl", &data.id) == -1) {
808 		mdb_warn("couldn't find struct dmu_buf_impl_t");
809 		return (DCMD_ERR);
810 	}
811 
812 	if (mdb_walk("dmu_buf_impl_t", dbufs_cb, &data) != 0) {
813 		mdb_warn("can't walk dbufs");
814 		return (DCMD_ERR);
815 	}
816 
817 	return (DCMD_OK);
818 }
819 
820 typedef struct abuf_find_data {
821 	dva_t dva;
822 	mdb_ctf_id_t id;
823 } abuf_find_data_t;
824 
825 /* ARGSUSED */
826 static int
827 abuf_find_cb(uintptr_t addr, const void *unknown, void *arg)
828 {
829 	abuf_find_data_t *data = arg;
830 	dva_t dva;
831 
832 	if (GETMEMBID(addr, &data->id, b_dva, dva)) {
833 		return (WALK_ERR);
834 	}
835 
836 	if (dva.dva_word[0] == data->dva.dva_word[0] &&
837 	    dva.dva_word[1] == data->dva.dva_word[1]) {
838 		mdb_printf("%#lr\n", addr);
839 	}
840 	return (WALK_NEXT);
841 }
842 
843 /* ARGSUSED */
844 static int
845 abuf_find(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
846 {
847 	abuf_find_data_t data;
848 	GElf_Sym sym;
849 	int i;
850 	const char *syms[] = {
851 		"ARC_mru",
852 		"ARC_mru_ghost",
853 		"ARC_mfu",
854 		"ARC_mfu_ghost",
855 	};
856 
857 	if (argc != 2)
858 		return (DCMD_USAGE);
859 
860 	for (i = 0; i < 2; i ++) {
861 		switch (argv[i].a_type) {
862 		case MDB_TYPE_STRING:
863 			data.dva.dva_word[i] = mdb_strtoull(argv[i].a_un.a_str);
864 			break;
865 		case MDB_TYPE_IMMEDIATE:
866 			data.dva.dva_word[i] = argv[i].a_un.a_val;
867 			break;
868 		default:
869 			return (DCMD_USAGE);
870 		}
871 	}
872 
873 	if (mdb_ctf_lookup_by_name(ZFS_STRUCT "arc_buf_hdr", &data.id) == -1) {
874 		mdb_warn("couldn't find struct arc_buf_hdr");
875 		return (DCMD_ERR);
876 	}
877 
878 	for (i = 0; i < sizeof (syms) / sizeof (syms[0]); i++) {
879 		if (mdb_lookup_by_obj(ZFS_OBJ_NAME, syms[i], &sym)) {
880 			mdb_warn("can't find symbol %s", syms[i]);
881 			return (DCMD_ERR);
882 		}
883 
884 		if (mdb_pwalk("list", abuf_find_cb, &data, sym.st_value) != 0) {
885 			mdb_warn("can't walk %s", syms[i]);
886 			return (DCMD_ERR);
887 		}
888 	}
889 
890 	return (DCMD_OK);
891 }
892 
893 
894 typedef struct dbgmsg_arg {
895 	boolean_t da_verbose;
896 	boolean_t da_address;
897 } dbgmsg_arg_t;
898 
899 /* ARGSUSED */
900 static int
901 dbgmsg_cb(uintptr_t addr, const void *unknown, void *arg)
902 {
903 	static mdb_ctf_id_t id;
904 	static boolean_t gotid;
905 	static ulong_t off;
906 
907 	dbgmsg_arg_t *da = arg;
908 	time_t timestamp;
909 	char buf[1024];
910 
911 	if (!gotid) {
912 		if (mdb_ctf_lookup_by_name(ZFS_STRUCT "zfs_dbgmsg", &id) ==
913 		    -1) {
914 			mdb_warn("couldn't find struct zfs_dbgmsg");
915 			return (WALK_ERR);
916 		}
917 		gotid = TRUE;
918 		if (mdb_ctf_offsetof(id, "zdm_msg", &off) == -1) {
919 			mdb_warn("couldn't find zdm_msg");
920 			return (WALK_ERR);
921 		}
922 		off /= 8;
923 	}
924 
925 
926 	if (GETMEMBID(addr, &id, zdm_timestamp, timestamp)) {
927 		return (WALK_ERR);
928 	}
929 
930 	if (mdb_readstr(buf, sizeof (buf), addr + off) == -1) {
931 		mdb_warn("failed to read zdm_msg at %p\n", addr + off);
932 		return (DCMD_ERR);
933 	}
934 
935 	if (da->da_address)
936 		mdb_printf("%p ", addr);
937 	if (da->da_verbose)
938 		mdb_printf("%Y ", timestamp);
939 
940 	mdb_printf("%s\n", buf);
941 
942 	if (da->da_verbose)
943 		(void) mdb_call_dcmd("whatis", addr, DCMD_ADDRSPEC, 0, NULL);
944 
945 	return (WALK_NEXT);
946 }
947 
948 /* ARGSUSED */
949 static int
950 dbgmsg(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
951 {
952 	GElf_Sym sym;
953 	dbgmsg_arg_t da = { 0 };
954 
955 	if (mdb_getopts(argc, argv,
956 	    'v', MDB_OPT_SETBITS, B_TRUE, &da.da_verbose,
957 	    'a', MDB_OPT_SETBITS, B_TRUE, &da.da_address,
958 	    NULL) != argc)
959 		return (DCMD_USAGE);
960 
961 	if (mdb_lookup_by_obj(ZFS_OBJ_NAME, "zfs_dbgmsgs", &sym)) {
962 		mdb_warn("can't find zfs_dbgmsgs");
963 		return (DCMD_ERR);
964 	}
965 
966 	if (mdb_pwalk("list", dbgmsg_cb, &da, sym.st_value) != 0) {
967 		mdb_warn("can't walk zfs_dbgmsgs");
968 		return (DCMD_ERR);
969 	}
970 
971 	return (DCMD_OK);
972 }
973 
974 /*ARGSUSED*/
975 static int
976 arc_print(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
977 {
978 	kstat_named_t *stats;
979 	GElf_Sym sym;
980 	int nstats, i;
981 	uint_t opt_a = FALSE;
982 	uint_t opt_b = FALSE;
983 	uint_t shift = 0;
984 	const char *suffix;
985 
986 	static const char *bytestats[] = {
987 		"p", "c", "c_min", "c_max", "size", "duplicate_buffers_size",
988 		"arc_meta_used", "arc_meta_limit", "arc_meta_max",
989 		"arc_meta_min", "hdr_size", "data_size", "metadata_size",
990 		"other_size", "anon_size", "anon_evictable_data",
991 		"anon_evictable_metadata", "mru_size", "mru_evictable_data",
992 		"mru_evictable_metadata", "mru_ghost_size",
993 		"mru_ghost_evictable_data", "mru_ghost_evictable_metadata",
994 		"mfu_size", "mfu_evictable_data", "mfu_evictable_metadata",
995 		"mfu_ghost_size", "mfu_ghost_evictable_data",
996 		"mfu_ghost_evictable_metadata", "evict_l2_cached",
997 		"evict_l2_eligible", "evict_l2_ineligible", "l2_read_bytes",
998 		"l2_write_bytes", "l2_size", "l2_asize", "l2_hdr_size",
999 		"compressed_size", "uncompressed_size", "overhead_size",
1000 		NULL
1001 	};
1002 
1003 	static const char *extras[] = {
1004 		"arc_no_grow", "arc_tempreserve",
1005 		NULL
1006 	};
1007 
1008 	if (mdb_lookup_by_obj(ZFS_OBJ_NAME, "arc_stats", &sym) == -1) {
1009 		mdb_warn("failed to find 'arc_stats'");
1010 		return (DCMD_ERR);
1011 	}
1012 
1013 	stats = mdb_zalloc(sym.st_size, UM_SLEEP | UM_GC);
1014 
1015 	if (mdb_vread(stats, sym.st_size, sym.st_value) == -1) {
1016 		mdb_warn("couldn't read 'arc_stats' at %p", sym.st_value);
1017 		return (DCMD_ERR);
1018 	}
1019 
1020 	nstats = sym.st_size / sizeof (kstat_named_t);
1021 
1022 	/* NB: -a / opt_a are ignored for backwards compatability */
1023 	if (mdb_getopts(argc, argv,
1024 	    'a', MDB_OPT_SETBITS, TRUE, &opt_a,
1025 	    'b', MDB_OPT_SETBITS, TRUE, &opt_b,
1026 	    'k', MDB_OPT_SETBITS, 10, &shift,
1027 	    'm', MDB_OPT_SETBITS, 20, &shift,
1028 	    'g', MDB_OPT_SETBITS, 30, &shift,
1029 	    NULL) != argc)
1030 		return (DCMD_USAGE);
1031 
1032 	if (!opt_b && !shift)
1033 		shift = 20;
1034 
1035 	switch (shift) {
1036 	case 0:
1037 		suffix = "B";
1038 		break;
1039 	case 10:
1040 		suffix = "KB";
1041 		break;
1042 	case 20:
1043 		suffix = "MB";
1044 		break;
1045 	case 30:
1046 		suffix = "GB";
1047 		break;
1048 	default:
1049 		suffix = "XX";
1050 	}
1051 
1052 	for (i = 0; i < nstats; i++) {
1053 		int j;
1054 		boolean_t bytes = B_FALSE;
1055 
1056 		for (j = 0; bytestats[j]; j++) {
1057 			if (strcmp(stats[i].name, bytestats[j]) == 0) {
1058 				bytes = B_TRUE;
1059 				break;
1060 			}
1061 		}
1062 
1063 		if (bytes) {
1064 			mdb_printf("%-25s = %9llu %s\n", stats[i].name,
1065 			    stats[i].value.ui64 >> shift, suffix);
1066 		} else {
1067 			mdb_printf("%-25s = %9llu\n", stats[i].name,
1068 			    stats[i].value.ui64);
1069 		}
1070 	}
1071 
1072 	for (i = 0; extras[i]; i++) {
1073 		uint64_t buf;
1074 
1075 		if (mdb_lookup_by_obj(ZFS_OBJ_NAME, extras[i], &sym) == -1) {
1076 			mdb_warn("failed to find '%s'", extras[i]);
1077 			return (DCMD_ERR);
1078 		}
1079 
1080 		if (sym.st_size != sizeof (uint64_t) &&
1081 		    sym.st_size != sizeof (uint32_t)) {
1082 			mdb_warn("expected scalar for variable '%s'\n",
1083 			    extras[i]);
1084 			return (DCMD_ERR);
1085 		}
1086 
1087 		if (mdb_vread(&buf, sym.st_size, sym.st_value) == -1) {
1088 			mdb_warn("couldn't read '%s'", extras[i]);
1089 			return (DCMD_ERR);
1090 		}
1091 
1092 		mdb_printf("%-25s = ", extras[i]);
1093 
1094 		/* NB: all the 64-bit extras happen to be byte counts */
1095 		if (sym.st_size == sizeof (uint64_t))
1096 			mdb_printf("%9llu %s\n", buf >> shift, suffix);
1097 
1098 		if (sym.st_size == sizeof (uint32_t))
1099 			mdb_printf("%9d\n", *((uint32_t *)&buf));
1100 	}
1101 	return (DCMD_OK);
1102 }
1103 
1104 typedef struct mdb_spa_print {
1105 	pool_state_t spa_state;
1106 	char spa_name[ZFS_MAX_DATASET_NAME_LEN];
1107 	uintptr_t spa_normal_class;
1108 } mdb_spa_print_t;
1109 
1110 
1111 const char histo_stars[] = "****************************************";
1112 const int histo_width = sizeof (histo_stars) - 1;
1113 
1114 static void
1115 dump_histogram(const uint64_t *histo, int size, int offset)
1116 {
1117 	int i;
1118 	int minidx = size - 1;
1119 	int maxidx = 0;
1120 	uint64_t max = 0;
1121 
1122 	for (i = 0; i < size; i++) {
1123 		if (histo[i] > max)
1124 			max = histo[i];
1125 		if (histo[i] > 0 && i > maxidx)
1126 			maxidx = i;
1127 		if (histo[i] > 0 && i < minidx)
1128 			minidx = i;
1129 	}
1130 
1131 	if (max < histo_width)
1132 		max = histo_width;
1133 
1134 	for (i = minidx; i <= maxidx; i++) {
1135 		mdb_printf("%3u: %6llu %s\n",
1136 		    i + offset, (u_longlong_t)histo[i],
1137 		    &histo_stars[(max - histo[i]) * histo_width / max]);
1138 	}
1139 }
1140 
1141 typedef struct mdb_metaslab_class {
1142 	uint64_t mc_histogram[RANGE_TREE_HISTOGRAM_SIZE];
1143 } mdb_metaslab_class_t;
1144 
1145 /*
1146  * spa_class_histogram(uintptr_t class_addr)
1147  *
1148  * Prints free space histogram for a device class
1149  *
1150  * Returns DCMD_OK, or DCMD_ERR.
1151  */
1152 static int
1153 spa_class_histogram(uintptr_t class_addr)
1154 {
1155 	mdb_metaslab_class_t mc;
1156 	if (mdb_ctf_vread(&mc, "metaslab_class_t",
1157 	    "mdb_metaslab_class_t", class_addr, 0) == -1)
1158 		return (DCMD_ERR);
1159 
1160 	mdb_inc_indent(4);
1161 	dump_histogram(mc.mc_histogram, RANGE_TREE_HISTOGRAM_SIZE, 0);
1162 	mdb_dec_indent(4);
1163 	return (DCMD_OK);
1164 }
1165 
1166 /*
1167  * ::spa
1168  *
1169  *	-c	Print configuration information as well
1170  *	-v	Print vdev state
1171  *	-e	Print vdev error stats
1172  *	-m	Print vdev metaslab info
1173  *	-M	print vdev metaslab group info
1174  *	-h	Print histogram info (must be combined with -m or -M)
1175  *
1176  * Print a summarized spa_t.  When given no arguments, prints out a table of all
1177  * active pools on the system.
1178  */
1179 /* ARGSUSED */
1180 static int
1181 spa_print(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
1182 {
1183 	const char *statetab[] = { "ACTIVE", "EXPORTED", "DESTROYED",
1184 		"SPARE", "L2CACHE", "UNINIT", "UNAVAIL", "POTENTIAL" };
1185 	const char *state;
1186 	int spa_flags = 0;
1187 
1188 	if (mdb_getopts(argc, argv,
1189 	    'c', MDB_OPT_SETBITS, SPA_FLAG_CONFIG, &spa_flags,
1190 	    'v', MDB_OPT_SETBITS, SPA_FLAG_VDEVS, &spa_flags,
1191 	    'e', MDB_OPT_SETBITS, SPA_FLAG_ERRORS, &spa_flags,
1192 	    'M', MDB_OPT_SETBITS, SPA_FLAG_METASLAB_GROUPS, &spa_flags,
1193 	    'm', MDB_OPT_SETBITS, SPA_FLAG_METASLABS, &spa_flags,
1194 	    'h', MDB_OPT_SETBITS, SPA_FLAG_HISTOGRAMS, &spa_flags,
1195 	    NULL) != argc)
1196 		return (DCMD_USAGE);
1197 
1198 	if (!(flags & DCMD_ADDRSPEC)) {
1199 		if (mdb_walk_dcmd("spa", "spa", argc, argv) == -1) {
1200 			mdb_warn("can't walk spa");
1201 			return (DCMD_ERR);
1202 		}
1203 
1204 		return (DCMD_OK);
1205 	}
1206 
1207 	if (flags & DCMD_PIPE_OUT) {
1208 		mdb_printf("%#lr\n", addr);
1209 		return (DCMD_OK);
1210 	}
1211 
1212 	if (DCMD_HDRSPEC(flags))
1213 		mdb_printf("%<u>%-?s %9s %-*s%</u>\n", "ADDR", "STATE",
1214 		    sizeof (uintptr_t) == 4 ? 60 : 52, "NAME");
1215 
1216 	mdb_spa_print_t spa;
1217 	if (mdb_ctf_vread(&spa, "spa_t", "mdb_spa_print_t", addr, 0) == -1)
1218 		return (DCMD_ERR);
1219 
1220 	if (spa.spa_state < 0 || spa.spa_state > POOL_STATE_UNAVAIL)
1221 		state = "UNKNOWN";
1222 	else
1223 		state = statetab[spa.spa_state];
1224 
1225 	mdb_printf("%0?p %9s %s\n", addr, state, spa.spa_name);
1226 	if (spa_flags & SPA_FLAG_HISTOGRAMS)
1227 		spa_class_histogram(spa.spa_normal_class);
1228 
1229 	if (spa_flags & SPA_FLAG_CONFIG) {
1230 		mdb_printf("\n");
1231 		mdb_inc_indent(4);
1232 		if (mdb_call_dcmd("spa_config", addr, flags, 0,
1233 		    NULL) != DCMD_OK)
1234 			return (DCMD_ERR);
1235 		mdb_dec_indent(4);
1236 	}
1237 
1238 	if (spa_flags & SPA_FLAG_ALL_VDEV) {
1239 		mdb_arg_t v;
1240 		char opts[100] = "-";
1241 		int args =
1242 		    (spa_flags | SPA_FLAG_VDEVS) == SPA_FLAG_VDEVS ? 0 : 1;
1243 
1244 		if (spa_flags & SPA_FLAG_ERRORS)
1245 			strcat(opts, "e");
1246 		if (spa_flags & SPA_FLAG_METASLABS)
1247 			strcat(opts, "m");
1248 		if (spa_flags & SPA_FLAG_METASLAB_GROUPS)
1249 			strcat(opts, "M");
1250 		if (spa_flags & SPA_FLAG_HISTOGRAMS)
1251 			strcat(opts, "h");
1252 
1253 		v.a_type = MDB_TYPE_STRING;
1254 		v.a_un.a_str = opts;
1255 
1256 		mdb_printf("\n");
1257 		mdb_inc_indent(4);
1258 		if (mdb_call_dcmd("spa_vdevs", addr, flags, args,
1259 		    &v) != DCMD_OK)
1260 			return (DCMD_ERR);
1261 		mdb_dec_indent(4);
1262 	}
1263 
1264 	return (DCMD_OK);
1265 }
1266 
1267 typedef struct mdb_spa_config_spa {
1268 	uintptr_t spa_config;
1269 } mdb_spa_config_spa_t;
1270 
1271 /*
1272  * ::spa_config
1273  *
1274  * Given a spa_t, print the configuration information stored in spa_config.
1275  * Since it's just an nvlist, format it as an indented list of name=value pairs.
1276  * We simply read the value of spa_config and pass off to ::nvlist.
1277  */
1278 /* ARGSUSED */
1279 static int
1280 spa_print_config(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
1281 {
1282 	mdb_spa_config_spa_t spa;
1283 
1284 	if (argc != 0 || !(flags & DCMD_ADDRSPEC))
1285 		return (DCMD_USAGE);
1286 
1287 	if (mdb_ctf_vread(&spa, ZFS_STRUCT "spa", "mdb_spa_config_spa_t",
1288 	    addr, 0) == -1)
1289 		return (DCMD_ERR);
1290 
1291 	if (spa.spa_config == 0) {
1292 		mdb_printf("(none)\n");
1293 		return (DCMD_OK);
1294 	}
1295 
1296 	return (mdb_call_dcmd("nvlist", spa.spa_config, flags,
1297 	    0, NULL));
1298 }
1299 
1300 
1301 
1302 typedef struct mdb_range_tree {
1303 	uint64_t rt_space;
1304 } mdb_range_tree_t;
1305 
1306 typedef struct mdb_metaslab_group {
1307 	uint64_t mg_fragmentation;
1308 	uint64_t mg_histogram[RANGE_TREE_HISTOGRAM_SIZE];
1309 	uintptr_t mg_vd;
1310 } mdb_metaslab_group_t;
1311 
1312 typedef struct mdb_metaslab {
1313 	uint64_t ms_id;
1314 	uint64_t ms_start;
1315 	uint64_t ms_size;
1316 	int64_t ms_deferspace;
1317 	uint64_t ms_fragmentation;
1318 	uint64_t ms_weight;
1319 	uintptr_t ms_alloctree[TXG_SIZE];
1320 	uintptr_t ms_freeingtree;
1321 	uintptr_t ms_freedtree;
1322 	uintptr_t ms_tree;
1323 	uintptr_t ms_sm;
1324 } mdb_metaslab_t;
1325 
1326 typedef struct mdb_space_map_phys_t {
1327 	uint64_t smp_alloc;
1328 	uint64_t smp_histogram[SPACE_MAP_HISTOGRAM_SIZE];
1329 } mdb_space_map_phys_t;
1330 
1331 typedef struct mdb_space_map {
1332 	uint64_t sm_size;
1333 	uint8_t sm_shift;
1334 	uint64_t sm_alloc;
1335 	uintptr_t sm_phys;
1336 } mdb_space_map_t;
1337 
1338 typedef struct mdb_vdev {
1339 	uintptr_t vdev_path;
1340 	uintptr_t vdev_ms;
1341 	uintptr_t vdev_ops;
1342 	uint64_t vdev_ms_count;
1343 	uint64_t vdev_id;
1344 	vdev_stat_t vdev_stat;
1345 } mdb_vdev_t;
1346 
1347 typedef struct mdb_vdev_ops {
1348 	char vdev_op_type[16];
1349 } mdb_vdev_ops_t;
1350 
1351 static int
1352 metaslab_stats(uintptr_t addr, int spa_flags)
1353 {
1354 	mdb_vdev_t vdev;
1355 	uintptr_t *vdev_ms;
1356 
1357 	if (mdb_ctf_vread(&vdev, "vdev_t", "mdb_vdev_t",
1358 	    (uintptr_t)addr, 0) == -1) {
1359 		mdb_warn("failed to read vdev at %p\n", addr);
1360 		return (DCMD_ERR);
1361 	}
1362 
1363 	mdb_inc_indent(4);
1364 	mdb_printf("%<u>%-?s %6s %20s %10s %9s%</u>\n", "ADDR", "ID",
1365 	    "OFFSET", "FREE", "FRAGMENTATION");
1366 
1367 	vdev_ms = mdb_alloc(vdev.vdev_ms_count * sizeof (void *),
1368 	    UM_SLEEP | UM_GC);
1369 	if (mdb_vread(vdev_ms, vdev.vdev_ms_count * sizeof (void *),
1370 	    (uintptr_t)vdev.vdev_ms) == -1) {
1371 		mdb_warn("failed to read vdev_ms at %p\n", vdev.vdev_ms);
1372 		return (DCMD_ERR);
1373 	}
1374 
1375 	for (int m = 0; m < vdev.vdev_ms_count; m++) {
1376 		mdb_metaslab_t ms;
1377 		mdb_space_map_t sm = { 0 };
1378 		char free[NICENUM_BUFLEN];
1379 
1380 		if (mdb_ctf_vread(&ms, "metaslab_t", "mdb_metaslab_t",
1381 		    (uintptr_t)vdev_ms[m], 0) == -1)
1382 			return (DCMD_ERR);
1383 
1384 		if (ms.ms_sm != NULL &&
1385 		    mdb_ctf_vread(&sm, "space_map_t", "mdb_space_map_t",
1386 		    ms.ms_sm, 0) == -1)
1387 			return (DCMD_ERR);
1388 
1389 		mdb_nicenum(ms.ms_size - sm.sm_alloc, free);
1390 
1391 		mdb_printf("%0?p %6llu %20llx %10s ", vdev_ms[m], ms.ms_id,
1392 		    ms.ms_start, free);
1393 		if (ms.ms_fragmentation == ZFS_FRAG_INVALID)
1394 			mdb_printf("%9s\n", "-");
1395 		else
1396 			mdb_printf("%9llu%%\n", ms.ms_fragmentation);
1397 
1398 		if ((spa_flags & SPA_FLAG_HISTOGRAMS) && ms.ms_sm != NULL) {
1399 			mdb_space_map_phys_t smp;
1400 
1401 			if (sm.sm_phys == NULL)
1402 				continue;
1403 
1404 			(void) mdb_ctf_vread(&smp, "space_map_phys_t",
1405 			    "mdb_space_map_phys_t", sm.sm_phys, 0);
1406 
1407 			dump_histogram(smp.smp_histogram,
1408 			    SPACE_MAP_HISTOGRAM_SIZE, sm.sm_shift);
1409 		}
1410 	}
1411 	mdb_dec_indent(4);
1412 	return (DCMD_OK);
1413 }
1414 
1415 static int
1416 metaslab_group_stats(uintptr_t addr, int spa_flags)
1417 {
1418 	mdb_metaslab_group_t mg;
1419 	if (mdb_ctf_vread(&mg, "metaslab_group_t", "mdb_metaslab_group_t",
1420 	    (uintptr_t)addr, 0) == -1) {
1421 		mdb_warn("failed to read vdev_mg at %p\n", addr);
1422 		return (DCMD_ERR);
1423 	}
1424 
1425 	mdb_inc_indent(4);
1426 	mdb_printf("%<u>%-?s %15s%</u>\n", "ADDR", "FRAGMENTATION");
1427 	if (mg.mg_fragmentation == ZFS_FRAG_INVALID)
1428 		mdb_printf("%0?p %15s\n", addr, "-");
1429 	else
1430 		mdb_printf("%0?p %15llu%%\n", addr, mg.mg_fragmentation);
1431 
1432 	if (spa_flags & SPA_FLAG_HISTOGRAMS)
1433 		dump_histogram(mg.mg_histogram, RANGE_TREE_HISTOGRAM_SIZE, 0);
1434 	mdb_dec_indent(4);
1435 	return (DCMD_OK);
1436 }
1437 
1438 /*
1439  * ::vdev
1440  *
1441  * Print out a summarized vdev_t, in the following form:
1442  *
1443  * ADDR             STATE	AUX            DESC
1444  * fffffffbcde23df0 HEALTHY	-              /dev/dsk/c0t0d0
1445  *
1446  * If '-r' is specified, recursively visit all children.
1447  *
1448  * With '-e', the statistics associated with the vdev are printed as well.
1449  */
1450 static int
1451 do_print_vdev(uintptr_t addr, int flags, int depth, boolean_t recursive,
1452     int spa_flags)
1453 {
1454 	vdev_t vdev;
1455 	char desc[MAXNAMELEN];
1456 	int c, children;
1457 	uintptr_t *child;
1458 	const char *state, *aux;
1459 
1460 	if (mdb_vread(&vdev, sizeof (vdev), (uintptr_t)addr) == -1) {
1461 		mdb_warn("failed to read vdev_t at %p\n", (uintptr_t)addr);
1462 		return (DCMD_ERR);
1463 	}
1464 
1465 	if (flags & DCMD_PIPE_OUT) {
1466 		mdb_printf("%#lr\n", addr);
1467 	} else {
1468 		if (vdev.vdev_path != NULL) {
1469 			if (mdb_readstr(desc, sizeof (desc),
1470 			    (uintptr_t)vdev.vdev_path) == -1) {
1471 				mdb_warn("failed to read vdev_path at %p\n",
1472 				    vdev.vdev_path);
1473 				return (DCMD_ERR);
1474 			}
1475 		} else if (vdev.vdev_ops != NULL) {
1476 			vdev_ops_t ops;
1477 			if (mdb_vread(&ops, sizeof (ops),
1478 			    (uintptr_t)vdev.vdev_ops) == -1) {
1479 				mdb_warn("failed to read vdev_ops at %p\n",
1480 				    vdev.vdev_ops);
1481 				return (DCMD_ERR);
1482 			}
1483 			(void) strcpy(desc, ops.vdev_op_type);
1484 		} else {
1485 			(void) strcpy(desc, "<unknown>");
1486 		}
1487 
1488 		if (depth == 0 && DCMD_HDRSPEC(flags))
1489 			mdb_printf("%<u>%-?s %-9s %-12s %-*s%</u>\n",
1490 			    "ADDR", "STATE", "AUX",
1491 			    sizeof (uintptr_t) == 4 ? 43 : 35,
1492 			    "DESCRIPTION");
1493 
1494 		mdb_printf("%0?p ", addr);
1495 
1496 		switch (vdev.vdev_state) {
1497 		case VDEV_STATE_CLOSED:
1498 			state = "CLOSED";
1499 			break;
1500 		case VDEV_STATE_OFFLINE:
1501 			state = "OFFLINE";
1502 			break;
1503 		case VDEV_STATE_CANT_OPEN:
1504 			state = "CANT_OPEN";
1505 			break;
1506 		case VDEV_STATE_DEGRADED:
1507 			state = "DEGRADED";
1508 			break;
1509 		case VDEV_STATE_HEALTHY:
1510 			state = "HEALTHY";
1511 			break;
1512 		case VDEV_STATE_REMOVED:
1513 			state = "REMOVED";
1514 			break;
1515 		case VDEV_STATE_FAULTED:
1516 			state = "FAULTED";
1517 			break;
1518 		default:
1519 			state = "UNKNOWN";
1520 			break;
1521 		}
1522 
1523 		switch (vdev.vdev_stat.vs_aux) {
1524 		case VDEV_AUX_NONE:
1525 			aux = "-";
1526 			break;
1527 		case VDEV_AUX_OPEN_FAILED:
1528 			aux = "OPEN_FAILED";
1529 			break;
1530 		case VDEV_AUX_CORRUPT_DATA:
1531 			aux = "CORRUPT_DATA";
1532 			break;
1533 		case VDEV_AUX_NO_REPLICAS:
1534 			aux = "NO_REPLICAS";
1535 			break;
1536 		case VDEV_AUX_BAD_GUID_SUM:
1537 			aux = "BAD_GUID_SUM";
1538 			break;
1539 		case VDEV_AUX_TOO_SMALL:
1540 			aux = "TOO_SMALL";
1541 			break;
1542 		case VDEV_AUX_BAD_LABEL:
1543 			aux = "BAD_LABEL";
1544 			break;
1545 		case VDEV_AUX_VERSION_NEWER:
1546 			aux = "VERS_NEWER";
1547 			break;
1548 		case VDEV_AUX_VERSION_OLDER:
1549 			aux = "VERS_OLDER";
1550 			break;
1551 		case VDEV_AUX_UNSUP_FEAT:
1552 			aux = "UNSUP_FEAT";
1553 			break;
1554 		case VDEV_AUX_SPARED:
1555 			aux = "SPARED";
1556 			break;
1557 		case VDEV_AUX_ERR_EXCEEDED:
1558 			aux = "ERR_EXCEEDED";
1559 			break;
1560 		case VDEV_AUX_IO_FAILURE:
1561 			aux = "IO_FAILURE";
1562 			break;
1563 		case VDEV_AUX_BAD_LOG:
1564 			aux = "BAD_LOG";
1565 			break;
1566 		case VDEV_AUX_EXTERNAL:
1567 			aux = "EXTERNAL";
1568 			break;
1569 		case VDEV_AUX_SPLIT_POOL:
1570 			aux = "SPLIT_POOL";
1571 			break;
1572 		default:
1573 			aux = "UNKNOWN";
1574 			break;
1575 		}
1576 
1577 		mdb_printf("%-9s %-12s %*s%s\n", state, aux, depth, "", desc);
1578 
1579 		if (spa_flags & SPA_FLAG_ERRORS) {
1580 			vdev_stat_t *vs = &vdev.vdev_stat;
1581 			int i;
1582 
1583 			mdb_inc_indent(4);
1584 			mdb_printf("\n");
1585 			mdb_printf("%<u>       %12s %12s %12s %12s "
1586 			    "%12s%</u>\n", "READ", "WRITE", "FREE", "CLAIM",
1587 			    "IOCTL");
1588 			mdb_printf("OPS     ");
1589 			for (i = 1; i < ZIO_TYPES; i++)
1590 				mdb_printf("%11#llx%s", vs->vs_ops[i],
1591 				    i == ZIO_TYPES - 1 ? "" : "  ");
1592 			mdb_printf("\n");
1593 			mdb_printf("BYTES   ");
1594 			for (i = 1; i < ZIO_TYPES; i++)
1595 				mdb_printf("%11#llx%s", vs->vs_bytes[i],
1596 				    i == ZIO_TYPES - 1 ? "" : "  ");
1597 
1598 
1599 			mdb_printf("\n");
1600 			mdb_printf("EREAD    %10#llx\n", vs->vs_read_errors);
1601 			mdb_printf("EWRITE   %10#llx\n", vs->vs_write_errors);
1602 			mdb_printf("ECKSUM   %10#llx\n",
1603 			    vs->vs_checksum_errors);
1604 			mdb_dec_indent(4);
1605 			mdb_printf("\n");
1606 		}
1607 
1608 		if (spa_flags & SPA_FLAG_METASLAB_GROUPS &&
1609 		    vdev.vdev_mg != NULL) {
1610 			metaslab_group_stats((uintptr_t)vdev.vdev_mg,
1611 			    spa_flags);
1612 		}
1613 		if (spa_flags & SPA_FLAG_METASLABS && vdev.vdev_ms != NULL) {
1614 			metaslab_stats((uintptr_t)addr, spa_flags);
1615 		}
1616 	}
1617 
1618 	children = vdev.vdev_children;
1619 
1620 	if (children == 0 || !recursive)
1621 		return (DCMD_OK);
1622 
1623 	child = mdb_alloc(children * sizeof (void *), UM_SLEEP | UM_GC);
1624 	if (mdb_vread(child, children * sizeof (void *),
1625 	    (uintptr_t)vdev.vdev_child) == -1) {
1626 		mdb_warn("failed to read vdev children at %p", vdev.vdev_child);
1627 		return (DCMD_ERR);
1628 	}
1629 
1630 	for (c = 0; c < children; c++) {
1631 		if (do_print_vdev(child[c], flags, depth + 2, recursive,
1632 		    spa_flags)) {
1633 			return (DCMD_ERR);
1634 		}
1635 	}
1636 
1637 	return (DCMD_OK);
1638 }
1639 
1640 static int
1641 vdev_print(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
1642 {
1643 	uint64_t depth = 0;
1644 	boolean_t recursive = B_FALSE;
1645 	int spa_flags = 0;
1646 
1647 	if (mdb_getopts(argc, argv,
1648 	    'e', MDB_OPT_SETBITS, SPA_FLAG_ERRORS, &spa_flags,
1649 	    'm', MDB_OPT_SETBITS, SPA_FLAG_METASLABS, &spa_flags,
1650 	    'M', MDB_OPT_SETBITS, SPA_FLAG_METASLAB_GROUPS, &spa_flags,
1651 	    'h', MDB_OPT_SETBITS, SPA_FLAG_HISTOGRAMS, &spa_flags,
1652 	    'r', MDB_OPT_SETBITS, TRUE, &recursive,
1653 	    'd', MDB_OPT_UINT64, &depth, NULL) != argc)
1654 		return (DCMD_USAGE);
1655 
1656 	if (!(flags & DCMD_ADDRSPEC)) {
1657 		mdb_warn("no vdev_t address given\n");
1658 		return (DCMD_ERR);
1659 	}
1660 
1661 	return (do_print_vdev(addr, flags, (int)depth, recursive, spa_flags));
1662 }
1663 
1664 typedef struct mdb_metaslab_alloc_trace {
1665 	uintptr_t mat_mg;
1666 	uintptr_t mat_msp;
1667 	uint64_t mat_size;
1668 	uint64_t mat_weight;
1669 	uint64_t mat_offset;
1670 	uint32_t mat_dva_id;
1671 } mdb_metaslab_alloc_trace_t;
1672 
1673 static void
1674 metaslab_print_weight(uint64_t weight)
1675 {
1676 	char buf[100];
1677 
1678 	if (WEIGHT_IS_SPACEBASED(weight)) {
1679 		mdb_nicenum(
1680 		    weight & ~(METASLAB_ACTIVE_MASK | METASLAB_WEIGHT_TYPE),
1681 		    buf);
1682 	} else {
1683 		char size[NICENUM_BUFLEN];
1684 		mdb_nicenum(1ULL << WEIGHT_GET_INDEX(weight), size);
1685 		(void) mdb_snprintf(buf, sizeof (buf), "%llu x %s",
1686 		    WEIGHT_GET_COUNT(weight), size);
1687 	}
1688 	mdb_printf("%11s ", buf);
1689 }
1690 
1691 /* ARGSUSED */
1692 static int
1693 metaslab_weight(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
1694 {
1695 	uint64_t weight = 0;
1696 	char active;
1697 
1698 	if (argc == 0 && (flags & DCMD_ADDRSPEC)) {
1699 		if (mdb_vread(&weight, sizeof (uint64_t), addr) == -1) {
1700 			mdb_warn("failed to read weight at %p\n", addr);
1701 			return (DCMD_ERR);
1702 		}
1703 	} else if (argc == 1 && !(flags & DCMD_ADDRSPEC)) {
1704 		weight = (argv[0].a_type == MDB_TYPE_IMMEDIATE) ?
1705 		    argv[0].a_un.a_val : mdb_strtoull(argv[0].a_un.a_str);
1706 	} else {
1707 		return (DCMD_USAGE);
1708 	}
1709 
1710 	if (DCMD_HDRSPEC(flags)) {
1711 		mdb_printf("%<u>%-6s %9s %9s%</u>\n",
1712 		    "ACTIVE", "ALGORITHM", "WEIGHT");
1713 	}
1714 
1715 	if (weight & METASLAB_WEIGHT_PRIMARY)
1716 		active = 'P';
1717 	else if (weight & METASLAB_WEIGHT_SECONDARY)
1718 		active = 'S';
1719 	else
1720 		active = '-';
1721 	mdb_printf("%6c %8s ", active,
1722 	    WEIGHT_IS_SPACEBASED(weight) ? "SPACE" : "SEGMENT");
1723 	metaslab_print_weight(weight);
1724 	mdb_printf("\n");
1725 
1726 	return (DCMD_OK);
1727 }
1728 
1729 /* ARGSUSED */
1730 static int
1731 metaslab_trace(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
1732 {
1733 	mdb_metaslab_alloc_trace_t mat;
1734 	mdb_metaslab_group_t mg = { 0 };
1735 	char result_type[100];
1736 
1737 	if (mdb_ctf_vread(&mat, "metaslab_alloc_trace_t",
1738 	    "mdb_metaslab_alloc_trace_t", addr, 0) == -1) {
1739 		return (DCMD_ERR);
1740 	}
1741 
1742 	if (!(flags & DCMD_PIPE_OUT) && DCMD_HDRSPEC(flags)) {
1743 		mdb_printf("%<u>%6s %6s %8s %11s %18s %18s%</u>\n",
1744 		    "MSID", "DVA", "ASIZE", "WEIGHT", "RESULT", "VDEV");
1745 	}
1746 
1747 	if (mat.mat_msp != NULL) {
1748 		mdb_metaslab_t ms;
1749 
1750 		if (mdb_ctf_vread(&ms, "metaslab_t", "mdb_metaslab_t",
1751 		    mat.mat_msp, 0) == -1) {
1752 			return (DCMD_ERR);
1753 		}
1754 		mdb_printf("%6llu ", ms.ms_id);
1755 	} else {
1756 		mdb_printf("%6s ", "-");
1757 	}
1758 
1759 	mdb_printf("%6d %8llx ", mat.mat_dva_id, mat.mat_size);
1760 
1761 	metaslab_print_weight(mat.mat_weight);
1762 
1763 	if ((int64_t)mat.mat_offset < 0) {
1764 		if (enum_lookup("enum trace_alloc_type", mat.mat_offset,
1765 		    "TRACE_", sizeof (result_type), result_type) == -1) {
1766 			mdb_warn("Could not find enum for trace_alloc_type");
1767 			return (DCMD_ERR);
1768 		}
1769 		mdb_printf("%18s ", result_type);
1770 	} else {
1771 		mdb_printf("%<b>%18llx%</b> ", mat.mat_offset);
1772 	}
1773 
1774 	if (mat.mat_mg != NULL &&
1775 	    mdb_ctf_vread(&mg, "metaslab_group_t", "mdb_metaslab_group_t",
1776 	    mat.mat_mg, 0) == -1) {
1777 		return (DCMD_ERR);
1778 	}
1779 
1780 	if (mg.mg_vd != NULL) {
1781 		mdb_vdev_t vdev;
1782 		char desc[MAXNAMELEN];
1783 
1784 		if (mdb_ctf_vread(&vdev, "vdev_t", "mdb_vdev_t",
1785 		    mg.mg_vd, 0) == -1) {
1786 			return (DCMD_ERR);
1787 		}
1788 
1789 		if (vdev.vdev_path != NULL) {
1790 			char path[MAXNAMELEN];
1791 
1792 			if (mdb_readstr(path, sizeof (path),
1793 			    vdev.vdev_path) == -1) {
1794 				mdb_warn("failed to read vdev_path at %p\n",
1795 				    vdev.vdev_path);
1796 				return (DCMD_ERR);
1797 			}
1798 			char *slash;
1799 			if ((slash = strrchr(path, '/')) != NULL) {
1800 				strcpy(desc, slash + 1);
1801 			} else {
1802 				strcpy(desc, path);
1803 			}
1804 		} else if (vdev.vdev_ops != NULL) {
1805 			mdb_vdev_ops_t ops;
1806 			if (mdb_ctf_vread(&ops, "vdev_ops_t", "mdb_vdev_ops_t",
1807 			    vdev.vdev_ops, 0) == -1) {
1808 				mdb_warn("failed to read vdev_ops at %p\n",
1809 				    vdev.vdev_ops);
1810 				return (DCMD_ERR);
1811 			}
1812 			(void) mdb_snprintf(desc, sizeof (desc),
1813 			    "%s-%llu", ops.vdev_op_type, vdev.vdev_id);
1814 		} else {
1815 			(void) strcpy(desc, "<unknown>");
1816 		}
1817 		mdb_printf("%18s\n", desc);
1818 	}
1819 
1820 	return (DCMD_OK);
1821 }
1822 
1823 typedef struct metaslab_walk_data {
1824 	uint64_t mw_numvdevs;
1825 	uintptr_t *mw_vdevs;
1826 	int mw_curvdev;
1827 	uint64_t mw_nummss;
1828 	uintptr_t *mw_mss;
1829 	int mw_curms;
1830 } metaslab_walk_data_t;
1831 
1832 static int
1833 metaslab_walk_step(mdb_walk_state_t *wsp)
1834 {
1835 	metaslab_walk_data_t *mw = wsp->walk_data;
1836 	metaslab_t ms;
1837 	uintptr_t msp;
1838 
1839 	if (mw->mw_curvdev >= mw->mw_numvdevs)
1840 		return (WALK_DONE);
1841 
1842 	if (mw->mw_mss == NULL) {
1843 		uintptr_t mssp;
1844 		uintptr_t vdevp;
1845 
1846 		ASSERT(mw->mw_curms == 0);
1847 		ASSERT(mw->mw_nummss == 0);
1848 
1849 		vdevp = mw->mw_vdevs[mw->mw_curvdev];
1850 		if (GETMEMB(vdevp, "vdev", vdev_ms, mssp) ||
1851 		    GETMEMB(vdevp, "vdev", vdev_ms_count, mw->mw_nummss)) {
1852 			return (WALK_ERR);
1853 		}
1854 
1855 		mw->mw_mss = mdb_alloc(mw->mw_nummss * sizeof (void*),
1856 		    UM_SLEEP | UM_GC);
1857 		if (mdb_vread(mw->mw_mss, mw->mw_nummss * sizeof (void*),
1858 		    mssp) == -1) {
1859 			mdb_warn("failed to read vdev_ms at %p", mssp);
1860 			return (WALK_ERR);
1861 		}
1862 	}
1863 
1864 	if (mw->mw_curms >= mw->mw_nummss) {
1865 		mw->mw_mss = NULL;
1866 		mw->mw_curms = 0;
1867 		mw->mw_nummss = 0;
1868 		mw->mw_curvdev++;
1869 		return (WALK_NEXT);
1870 	}
1871 
1872 	msp = mw->mw_mss[mw->mw_curms];
1873 	if (mdb_vread(&ms, sizeof (metaslab_t), msp) == -1) {
1874 		mdb_warn("failed to read metaslab_t at %p", msp);
1875 		return (WALK_ERR);
1876 	}
1877 
1878 	mw->mw_curms++;
1879 
1880 	return (wsp->walk_callback(msp, &ms, wsp->walk_cbdata));
1881 }
1882 
1883 static int
1884 metaslab_walk_init(mdb_walk_state_t *wsp)
1885 {
1886 	metaslab_walk_data_t *mw;
1887 	uintptr_t root_vdevp;
1888 	uintptr_t childp;
1889 
1890 	if (wsp->walk_addr == NULL) {
1891 		mdb_warn("must supply address of spa_t\n");
1892 		return (WALK_ERR);
1893 	}
1894 
1895 	mw = mdb_zalloc(sizeof (metaslab_walk_data_t), UM_SLEEP | UM_GC);
1896 
1897 	if (GETMEMB(wsp->walk_addr, "spa", spa_root_vdev, root_vdevp) ||
1898 	    GETMEMB(root_vdevp, "vdev", vdev_children, mw->mw_numvdevs) ||
1899 	    GETMEMB(root_vdevp, "vdev", vdev_child, childp)) {
1900 		return (DCMD_ERR);
1901 	}
1902 
1903 	mw->mw_vdevs = mdb_alloc(mw->mw_numvdevs * sizeof (void *),
1904 	    UM_SLEEP | UM_GC);
1905 	if (mdb_vread(mw->mw_vdevs, mw->mw_numvdevs * sizeof (void *),
1906 	    childp) == -1) {
1907 		mdb_warn("failed to read root vdev children at %p", childp);
1908 		return (DCMD_ERR);
1909 	}
1910 
1911 	wsp->walk_data = mw;
1912 
1913 	return (WALK_NEXT);
1914 }
1915 
1916 typedef struct mdb_spa {
1917 	uintptr_t spa_dsl_pool;
1918 	uintptr_t spa_root_vdev;
1919 } mdb_spa_t;
1920 
1921 typedef struct mdb_dsl_pool {
1922 	uintptr_t dp_root_dir;
1923 } mdb_dsl_pool_t;
1924 
1925 typedef struct mdb_dsl_dir {
1926 	uintptr_t dd_dbuf;
1927 	int64_t dd_space_towrite[TXG_SIZE];
1928 } mdb_dsl_dir_t;
1929 
1930 typedef struct mdb_dsl_dir_phys {
1931 	uint64_t dd_used_bytes;
1932 	uint64_t dd_compressed_bytes;
1933 	uint64_t dd_uncompressed_bytes;
1934 } mdb_dsl_dir_phys_t;
1935 
1936 typedef struct space_data {
1937 	uint64_t ms_alloctree[TXG_SIZE];
1938 	uint64_t ms_freeingtree;
1939 	uint64_t ms_freedtree;
1940 	uint64_t ms_tree;
1941 	int64_t ms_deferspace;
1942 	uint64_t avail;
1943 	uint64_t nowavail;
1944 } space_data_t;
1945 
1946 /* ARGSUSED */
1947 static int
1948 space_cb(uintptr_t addr, const void *unknown, void *arg)
1949 {
1950 	space_data_t *sd = arg;
1951 	mdb_metaslab_t ms;
1952 	mdb_range_tree_t rt;
1953 	mdb_space_map_t sm = { 0 };
1954 	mdb_space_map_phys_t smp = { 0 };
1955 	int i;
1956 
1957 	if (mdb_ctf_vread(&ms, "metaslab_t", "mdb_metaslab_t",
1958 	    addr, 0) == -1)
1959 		return (WALK_ERR);
1960 
1961 	for (i = 0; i < TXG_SIZE; i++) {
1962 		if (mdb_ctf_vread(&rt, "range_tree_t",
1963 		    "mdb_range_tree_t", ms.ms_alloctree[i], 0) == -1)
1964 			return (WALK_ERR);
1965 
1966 		sd->ms_alloctree[i] += rt.rt_space;
1967 
1968 	}
1969 
1970 	if (mdb_ctf_vread(&rt, "range_tree_t",
1971 	    "mdb_range_tree_t", ms.ms_freeingtree, 0) == -1)
1972 		return (WALK_ERR);
1973 	sd->ms_freeingtree += rt.rt_space;
1974 
1975 	if (mdb_ctf_vread(&rt, "range_tree_t",
1976 	    "mdb_range_tree_t", ms.ms_freedtree, 0) == -1)
1977 		return (WALK_ERR);
1978 	sd->ms_freedtree += rt.rt_space;
1979 
1980 	if (mdb_ctf_vread(&rt, "range_tree_t",
1981 	    "mdb_range_tree_t", ms.ms_tree, 0) == -1)
1982 		return (WALK_ERR);
1983 	sd->ms_tree += rt.rt_space;
1984 
1985 	if (ms.ms_sm != NULL &&
1986 	    mdb_ctf_vread(&sm, "space_map_t",
1987 	    "mdb_space_map_t", ms.ms_sm, 0) == -1)
1988 		return (WALK_ERR);
1989 
1990 	if (sm.sm_phys != NULL) {
1991 		(void) mdb_ctf_vread(&smp, "space_map_phys_t",
1992 		    "mdb_space_map_phys_t", sm.sm_phys, 0);
1993 	}
1994 
1995 	sd->ms_deferspace += ms.ms_deferspace;
1996 	sd->avail += sm.sm_size - sm.sm_alloc;
1997 	sd->nowavail += sm.sm_size - smp.smp_alloc;
1998 
1999 	return (WALK_NEXT);
2000 }
2001 
2002 /*
2003  * ::spa_space [-b]
2004  *
2005  * Given a spa_t, print out it's on-disk space usage and in-core
2006  * estimates of future usage.  If -b is given, print space in bytes.
2007  * Otherwise print in megabytes.
2008  */
2009 /* ARGSUSED */
2010 static int
2011 spa_space(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
2012 {
2013 	mdb_spa_t spa;
2014 	mdb_dsl_pool_t dp;
2015 	mdb_dsl_dir_t dd;
2016 	mdb_dmu_buf_impl_t db;
2017 	mdb_dsl_dir_phys_t dsp;
2018 	space_data_t sd;
2019 	int shift = 20;
2020 	char *suffix = "M";
2021 	int bytes = B_FALSE;
2022 
2023 	if (mdb_getopts(argc, argv, 'b', MDB_OPT_SETBITS, TRUE, &bytes, NULL) !=
2024 	    argc)
2025 		return (DCMD_USAGE);
2026 	if (!(flags & DCMD_ADDRSPEC))
2027 		return (DCMD_USAGE);
2028 
2029 	if (bytes) {
2030 		shift = 0;
2031 		suffix = "";
2032 	}
2033 
2034 	if (mdb_ctf_vread(&spa, ZFS_STRUCT "spa", "mdb_spa_t",
2035 	    addr, 0) == -1 ||
2036 	    mdb_ctf_vread(&dp, ZFS_STRUCT "dsl_pool", "mdb_dsl_pool_t",
2037 	    spa.spa_dsl_pool, 0) == -1 ||
2038 	    mdb_ctf_vread(&dd, ZFS_STRUCT "dsl_dir", "mdb_dsl_dir_t",
2039 	    dp.dp_root_dir, 0) == -1 ||
2040 	    mdb_ctf_vread(&db, ZFS_STRUCT "dmu_buf_impl", "mdb_dmu_buf_impl_t",
2041 	    dd.dd_dbuf, 0) == -1 ||
2042 	    mdb_ctf_vread(&dsp, ZFS_STRUCT "dsl_dir_phys",
2043 	    "mdb_dsl_dir_phys_t", db.db.db_data, 0) == -1) {
2044 		return (DCMD_ERR);
2045 	}
2046 
2047 	mdb_printf("dd_space_towrite = %llu%s %llu%s %llu%s %llu%s\n",
2048 	    dd.dd_space_towrite[0] >> shift, suffix,
2049 	    dd.dd_space_towrite[1] >> shift, suffix,
2050 	    dd.dd_space_towrite[2] >> shift, suffix,
2051 	    dd.dd_space_towrite[3] >> shift, suffix);
2052 
2053 	mdb_printf("dd_phys.dd_used_bytes = %llu%s\n",
2054 	    dsp.dd_used_bytes >> shift, suffix);
2055 	mdb_printf("dd_phys.dd_compressed_bytes = %llu%s\n",
2056 	    dsp.dd_compressed_bytes >> shift, suffix);
2057 	mdb_printf("dd_phys.dd_uncompressed_bytes = %llu%s\n",
2058 	    dsp.dd_uncompressed_bytes >> shift, suffix);
2059 
2060 	bzero(&sd, sizeof (sd));
2061 	if (mdb_pwalk("metaslab", space_cb, &sd, addr) != 0) {
2062 		mdb_warn("can't walk metaslabs");
2063 		return (DCMD_ERR);
2064 	}
2065 
2066 	mdb_printf("ms_allocmap = %llu%s %llu%s %llu%s %llu%s\n",
2067 	    sd.ms_alloctree[0] >> shift, suffix,
2068 	    sd.ms_alloctree[1] >> shift, suffix,
2069 	    sd.ms_alloctree[2] >> shift, suffix,
2070 	    sd.ms_alloctree[3] >> shift, suffix);
2071 	mdb_printf("ms_freeingtree = %llu%s\n",
2072 	    sd.ms_freeingtree >> shift, suffix);
2073 	mdb_printf("ms_freedtree = %llu%s\n",
2074 	    sd.ms_freedtree >> shift, suffix);
2075 	mdb_printf("ms_tree = %llu%s\n",
2076 	    sd.ms_tree >> shift, suffix);
2077 	mdb_printf("ms_deferspace = %llu%s\n",
2078 	    sd.ms_deferspace >> shift, suffix);
2079 	mdb_printf("last synced avail = %llu%s\n",
2080 	    sd.avail >> shift, suffix);
2081 	mdb_printf("current syncing avail = %llu%s\n",
2082 	    sd.nowavail >> shift, suffix);
2083 
2084 	return (DCMD_OK);
2085 }
2086 
2087 typedef struct mdb_spa_aux_vdev {
2088 	int sav_count;
2089 	uintptr_t sav_vdevs;
2090 } mdb_spa_aux_vdev_t;
2091 
2092 typedef struct mdb_spa_vdevs {
2093 	uintptr_t spa_root_vdev;
2094 	mdb_spa_aux_vdev_t spa_l2cache;
2095 	mdb_spa_aux_vdev_t spa_spares;
2096 } mdb_spa_vdevs_t;
2097 
2098 static int
2099 spa_print_aux(mdb_spa_aux_vdev_t *sav, uint_t flags, mdb_arg_t *v,
2100     const char *name)
2101 {
2102 	uintptr_t *aux;
2103 	size_t len;
2104 	int ret, i;
2105 
2106 	/*
2107 	 * Iterate over aux vdevs and print those out as well.  This is a
2108 	 * little annoying because we don't have a root vdev to pass to ::vdev.
2109 	 * Instead, we print a single line and then call it for each child
2110 	 * vdev.
2111 	 */
2112 	if (sav->sav_count != 0) {
2113 		v[1].a_type = MDB_TYPE_STRING;
2114 		v[1].a_un.a_str = "-d";
2115 		v[2].a_type = MDB_TYPE_IMMEDIATE;
2116 		v[2].a_un.a_val = 2;
2117 
2118 		len = sav->sav_count * sizeof (uintptr_t);
2119 		aux = mdb_alloc(len, UM_SLEEP);
2120 		if (mdb_vread(aux, len, sav->sav_vdevs) == -1) {
2121 			mdb_free(aux, len);
2122 			mdb_warn("failed to read l2cache vdevs at %p",
2123 			    sav->sav_vdevs);
2124 			return (DCMD_ERR);
2125 		}
2126 
2127 		mdb_printf("%-?s %-9s %-12s %s\n", "-", "-", "-", name);
2128 
2129 		for (i = 0; i < sav->sav_count; i++) {
2130 			ret = mdb_call_dcmd("vdev", aux[i], flags, 3, v);
2131 			if (ret != DCMD_OK) {
2132 				mdb_free(aux, len);
2133 				return (ret);
2134 			}
2135 		}
2136 
2137 		mdb_free(aux, len);
2138 	}
2139 
2140 	return (0);
2141 }
2142 
2143 /*
2144  * ::spa_vdevs
2145  *
2146  *	-e	Include error stats
2147  *	-m	Include metaslab information
2148  *	-M	Include metaslab group information
2149  *	-h	Include histogram information (requires -m or -M)
2150  *
2151  * Print out a summarized list of vdevs for the given spa_t.
2152  * This is accomplished by invoking "::vdev -re" on the root vdev, as well as
2153  * iterating over the cache devices.
2154  */
2155 /* ARGSUSED */
2156 static int
2157 spa_vdevs(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
2158 {
2159 	mdb_arg_t v[3];
2160 	int ret;
2161 	char opts[100] = "-r";
2162 	int spa_flags = 0;
2163 
2164 	if (mdb_getopts(argc, argv,
2165 	    'e', MDB_OPT_SETBITS, SPA_FLAG_ERRORS, &spa_flags,
2166 	    'm', MDB_OPT_SETBITS, SPA_FLAG_METASLABS, &spa_flags,
2167 	    'M', MDB_OPT_SETBITS, SPA_FLAG_METASLAB_GROUPS, &spa_flags,
2168 	    'h', MDB_OPT_SETBITS, SPA_FLAG_HISTOGRAMS, &spa_flags,
2169 	    NULL) != argc)
2170 		return (DCMD_USAGE);
2171 
2172 	if (!(flags & DCMD_ADDRSPEC))
2173 		return (DCMD_USAGE);
2174 
2175 	mdb_spa_vdevs_t spa;
2176 	if (mdb_ctf_vread(&spa, "spa_t", "mdb_spa_vdevs_t", addr, 0) == -1)
2177 		return (DCMD_ERR);
2178 
2179 	/*
2180 	 * Unitialized spa_t structures can have a NULL root vdev.
2181 	 */
2182 	if (spa.spa_root_vdev == NULL) {
2183 		mdb_printf("no associated vdevs\n");
2184 		return (DCMD_OK);
2185 	}
2186 
2187 	if (spa_flags & SPA_FLAG_ERRORS)
2188 		strcat(opts, "e");
2189 	if (spa_flags & SPA_FLAG_METASLABS)
2190 		strcat(opts, "m");
2191 	if (spa_flags & SPA_FLAG_METASLAB_GROUPS)
2192 		strcat(opts, "M");
2193 	if (spa_flags & SPA_FLAG_HISTOGRAMS)
2194 		strcat(opts, "h");
2195 
2196 	v[0].a_type = MDB_TYPE_STRING;
2197 	v[0].a_un.a_str = opts;
2198 
2199 	ret = mdb_call_dcmd("vdev", (uintptr_t)spa.spa_root_vdev,
2200 	    flags, 1, v);
2201 	if (ret != DCMD_OK)
2202 		return (ret);
2203 
2204 	if (spa_print_aux(&spa.spa_l2cache, flags, v, "cache") != 0 ||
2205 	    spa_print_aux(&spa.spa_spares, flags, v, "spares") != 0)
2206 		return (DCMD_ERR);
2207 
2208 	return (DCMD_OK);
2209 }
2210 
2211 /*
2212  * ::zio
2213  *
2214  * Print a summary of zio_t and all its children.  This is intended to display a
2215  * zio tree, and hence we only pick the most important pieces of information for
2216  * the main summary.  More detailed information can always be found by doing a
2217  * '::print zio' on the underlying zio_t.  The columns we display are:
2218  *
2219  *	ADDRESS  TYPE  STAGE  WAITER  TIME_ELAPSED
2220  *
2221  * The 'address' column is indented by one space for each depth level as we
2222  * descend down the tree.
2223  */
2224 
2225 #define	ZIO_MAXINDENT	7
2226 #define	ZIO_MAXWIDTH	(sizeof (uintptr_t) * 2 + ZIO_MAXINDENT)
2227 #define	ZIO_WALK_SELF	0
2228 #define	ZIO_WALK_CHILD	1
2229 #define	ZIO_WALK_PARENT	2
2230 
2231 typedef struct zio_print_args {
2232 	int	zpa_current_depth;
2233 	int	zpa_min_depth;
2234 	int	zpa_max_depth;
2235 	int	zpa_type;
2236 	uint_t	zpa_flags;
2237 } zio_print_args_t;
2238 
2239 typedef struct mdb_zio {
2240 	enum zio_type io_type;
2241 	enum zio_stage io_stage;
2242 	uintptr_t io_waiter;
2243 	uintptr_t io_spa;
2244 	struct {
2245 		struct {
2246 			uintptr_t list_next;
2247 		} list_head;
2248 	} io_parent_list;
2249 	int io_error;
2250 } mdb_zio_t;
2251 
2252 typedef struct mdb_zio_timestamp {
2253 	hrtime_t io_timestamp;
2254 } mdb_zio_timestamp_t;
2255 
2256 static int zio_child_cb(uintptr_t addr, const void *unknown, void *arg);
2257 
2258 static int
2259 zio_print_cb(uintptr_t addr, zio_print_args_t *zpa)
2260 {
2261 	mdb_ctf_id_t type_enum, stage_enum;
2262 	int indent = zpa->zpa_current_depth;
2263 	const char *type, *stage;
2264 	uintptr_t laddr;
2265 	mdb_zio_t zio;
2266 	mdb_zio_timestamp_t zio_timestamp = { 0 };
2267 
2268 	if (mdb_ctf_vread(&zio, ZFS_STRUCT "zio", "mdb_zio_t", addr, 0) == -1)
2269 		return (WALK_ERR);
2270 	(void) mdb_ctf_vread(&zio_timestamp, ZFS_STRUCT "zio",
2271 	    "mdb_zio_timestamp_t", addr, MDB_CTF_VREAD_QUIET);
2272 
2273 	if (indent > ZIO_MAXINDENT)
2274 		indent = ZIO_MAXINDENT;
2275 
2276 	if (mdb_ctf_lookup_by_name("enum zio_type", &type_enum) == -1 ||
2277 	    mdb_ctf_lookup_by_name("enum zio_stage", &stage_enum) == -1) {
2278 		mdb_warn("failed to lookup zio enums");
2279 		return (WALK_ERR);
2280 	}
2281 
2282 	if ((type = mdb_ctf_enum_name(type_enum, zio.io_type)) != NULL)
2283 		type += sizeof ("ZIO_TYPE_") - 1;
2284 	else
2285 		type = "?";
2286 
2287 	if (zio.io_error == 0) {
2288 		stage = mdb_ctf_enum_name(stage_enum, zio.io_stage);
2289 		if (stage != NULL)
2290 			stage += sizeof ("ZIO_STAGE_") - 1;
2291 		else
2292 			stage = "?";
2293 	} else {
2294 		stage = "FAILED";
2295 	}
2296 
2297 	if (zpa->zpa_current_depth >= zpa->zpa_min_depth) {
2298 		if (zpa->zpa_flags & DCMD_PIPE_OUT) {
2299 			mdb_printf("%?p\n", addr);
2300 		} else {
2301 			mdb_printf("%*s%-*p %-5s %-16s ", indent, "",
2302 			    ZIO_MAXWIDTH - indent, addr, type, stage);
2303 			if (zio.io_waiter != 0)
2304 				mdb_printf("%-16lx ", zio.io_waiter);
2305 			else
2306 				mdb_printf("%-16s ", "-");
2307 #ifdef _KERNEL
2308 			if (zio_timestamp.io_timestamp != 0) {
2309 				mdb_printf("%llums", (mdb_gethrtime() -
2310 				    zio_timestamp.io_timestamp) /
2311 				    1000000);
2312 			} else {
2313 				mdb_printf("%-12s ", "-");
2314 			}
2315 #else
2316 			mdb_printf("%-12s ", "-");
2317 #endif
2318 			mdb_printf("\n");
2319 		}
2320 	}
2321 
2322 	if (zpa->zpa_current_depth >= zpa->zpa_max_depth)
2323 		return (WALK_NEXT);
2324 
2325 	if (zpa->zpa_type == ZIO_WALK_PARENT)
2326 		laddr = addr + mdb_ctf_offsetof_by_name(ZFS_STRUCT "zio",
2327 		    "io_parent_list");
2328 	else
2329 		laddr = addr + mdb_ctf_offsetof_by_name(ZFS_STRUCT "zio",
2330 		    "io_child_list");
2331 
2332 	zpa->zpa_current_depth++;
2333 	if (mdb_pwalk("list", zio_child_cb, zpa, laddr) != 0) {
2334 		mdb_warn("failed to walk zio_t children at %p\n", laddr);
2335 		return (WALK_ERR);
2336 	}
2337 	zpa->zpa_current_depth--;
2338 
2339 	return (WALK_NEXT);
2340 }
2341 
2342 /* ARGSUSED */
2343 static int
2344 zio_child_cb(uintptr_t addr, const void *unknown, void *arg)
2345 {
2346 	zio_link_t zl;
2347 	uintptr_t ziop;
2348 	zio_print_args_t *zpa = arg;
2349 
2350 	if (mdb_vread(&zl, sizeof (zl), addr) == -1) {
2351 		mdb_warn("failed to read zio_link_t at %p", addr);
2352 		return (WALK_ERR);
2353 	}
2354 
2355 	if (zpa->zpa_type == ZIO_WALK_PARENT)
2356 		ziop = (uintptr_t)zl.zl_parent;
2357 	else
2358 		ziop = (uintptr_t)zl.zl_child;
2359 
2360 	return (zio_print_cb(ziop, zpa));
2361 }
2362 
2363 /* ARGSUSED */
2364 static int
2365 zio_print(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
2366 {
2367 	zio_print_args_t zpa = { 0 };
2368 
2369 	if (!(flags & DCMD_ADDRSPEC))
2370 		return (DCMD_USAGE);
2371 
2372 	if (mdb_getopts(argc, argv,
2373 	    'r', MDB_OPT_SETBITS, INT_MAX, &zpa.zpa_max_depth,
2374 	    'c', MDB_OPT_SETBITS, ZIO_WALK_CHILD, &zpa.zpa_type,
2375 	    'p', MDB_OPT_SETBITS, ZIO_WALK_PARENT, &zpa.zpa_type,
2376 	    NULL) != argc)
2377 		return (DCMD_USAGE);
2378 
2379 	zpa.zpa_flags = flags;
2380 	if (zpa.zpa_max_depth != 0) {
2381 		if (zpa.zpa_type == ZIO_WALK_SELF)
2382 			zpa.zpa_type = ZIO_WALK_CHILD;
2383 	} else if (zpa.zpa_type != ZIO_WALK_SELF) {
2384 		zpa.zpa_min_depth = 1;
2385 		zpa.zpa_max_depth = 1;
2386 	}
2387 
2388 	if (!(flags & DCMD_PIPE_OUT) && DCMD_HDRSPEC(flags)) {
2389 		mdb_printf("%<u>%-*s %-5s %-16s %-16s %-12s%</u>\n",
2390 		    ZIO_MAXWIDTH, "ADDRESS", "TYPE", "STAGE", "WAITER",
2391 		    "TIME_ELAPSED");
2392 	}
2393 
2394 	if (zio_print_cb(addr, &zpa) != WALK_NEXT)
2395 		return (DCMD_ERR);
2396 
2397 	return (DCMD_OK);
2398 }
2399 
2400 /*
2401  * [addr]::zio_state
2402  *
2403  * Print a summary of all zio_t structures on the system, or for a particular
2404  * pool.  This is equivalent to '::walk zio_root | ::zio'.
2405  */
2406 /*ARGSUSED*/
2407 static int
2408 zio_state(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
2409 {
2410 	/*
2411 	 * MDB will remember the last address of the pipeline, so if we don't
2412 	 * zero this we'll end up trying to walk zio structures for a
2413 	 * non-existent spa_t.
2414 	 */
2415 	if (!(flags & DCMD_ADDRSPEC))
2416 		addr = 0;
2417 
2418 	return (mdb_pwalk_dcmd("zio_root", "zio", argc, argv, addr));
2419 }
2420 
2421 typedef struct mdb_multilist {
2422 	uint64_t ml_num_sublists;
2423 	uintptr_t ml_sublists;
2424 } mdb_multilist_t;
2425 
2426 typedef struct multilist_walk_data {
2427 	uint64_t mwd_idx;
2428 	mdb_multilist_t mwd_ml;
2429 } multilist_walk_data_t;
2430 
2431 /* ARGSUSED */
2432 static int
2433 multilist_print_cb(uintptr_t addr, const void *unknown, void *arg)
2434 {
2435 	mdb_printf("%#lr\n", addr);
2436 	return (WALK_NEXT);
2437 }
2438 
2439 static int
2440 multilist_walk_step(mdb_walk_state_t *wsp)
2441 {
2442 	multilist_walk_data_t *mwd = wsp->walk_data;
2443 
2444 	if (mwd->mwd_idx >= mwd->mwd_ml.ml_num_sublists)
2445 		return (WALK_DONE);
2446 
2447 	wsp->walk_addr = mwd->mwd_ml.ml_sublists +
2448 	    mdb_ctf_sizeof_by_name("multilist_sublist_t") * mwd->mwd_idx +
2449 	    mdb_ctf_offsetof_by_name("multilist_sublist_t", "mls_list");
2450 
2451 	mdb_pwalk("list", multilist_print_cb, (void*)NULL, wsp->walk_addr);
2452 	mwd->mwd_idx++;
2453 
2454 	return (WALK_NEXT);
2455 }
2456 
2457 static int
2458 multilist_walk_init(mdb_walk_state_t *wsp)
2459 {
2460 	multilist_walk_data_t *mwd;
2461 
2462 	if (wsp->walk_addr == NULL) {
2463 		mdb_warn("must supply address of multilist_t\n");
2464 		return (WALK_ERR);
2465 	}
2466 
2467 	mwd = mdb_zalloc(sizeof (multilist_walk_data_t), UM_SLEEP | UM_GC);
2468 	if (mdb_ctf_vread(&mwd->mwd_ml, "multilist_t", "mdb_multilist_t",
2469 	    wsp->walk_addr, 0) == -1) {
2470 		return (WALK_ERR);
2471 	}
2472 
2473 	if (mwd->mwd_ml.ml_num_sublists == 0 ||
2474 	    mwd->mwd_ml.ml_sublists == NULL) {
2475 		mdb_warn("invalid or uninitialized multilist at %#lx\n",
2476 		    wsp->walk_addr);
2477 		return (WALK_ERR);
2478 	}
2479 
2480 	wsp->walk_data = mwd;
2481 	return (WALK_NEXT);
2482 }
2483 
2484 typedef struct mdb_txg_list {
2485 	size_t		tl_offset;
2486 	uintptr_t	tl_head[TXG_SIZE];
2487 } mdb_txg_list_t;
2488 
2489 typedef struct txg_list_walk_data {
2490 	uintptr_t lw_head[TXG_SIZE];
2491 	int	lw_txgoff;
2492 	int	lw_maxoff;
2493 	size_t	lw_offset;
2494 	void	*lw_obj;
2495 } txg_list_walk_data_t;
2496 
2497 static int
2498 txg_list_walk_init_common(mdb_walk_state_t *wsp, int txg, int maxoff)
2499 {
2500 	txg_list_walk_data_t *lwd;
2501 	mdb_txg_list_t list;
2502 	int i;
2503 
2504 	lwd = mdb_alloc(sizeof (txg_list_walk_data_t), UM_SLEEP | UM_GC);
2505 	if (mdb_ctf_vread(&list, "txg_list_t", "mdb_txg_list_t", wsp->walk_addr,
2506 	    0) == -1) {
2507 		mdb_warn("failed to read txg_list_t at %#lx", wsp->walk_addr);
2508 		return (WALK_ERR);
2509 	}
2510 
2511 	for (i = 0; i < TXG_SIZE; i++)
2512 		lwd->lw_head[i] = list.tl_head[i];
2513 	lwd->lw_offset = list.tl_offset;
2514 	lwd->lw_obj = mdb_alloc(lwd->lw_offset + sizeof (txg_node_t),
2515 	    UM_SLEEP | UM_GC);
2516 	lwd->lw_txgoff = txg;
2517 	lwd->lw_maxoff = maxoff;
2518 
2519 	wsp->walk_addr = lwd->lw_head[lwd->lw_txgoff];
2520 	wsp->walk_data = lwd;
2521 
2522 	return (WALK_NEXT);
2523 }
2524 
2525 static int
2526 txg_list_walk_init(mdb_walk_state_t *wsp)
2527 {
2528 	return (txg_list_walk_init_common(wsp, 0, TXG_SIZE-1));
2529 }
2530 
2531 static int
2532 txg_list0_walk_init(mdb_walk_state_t *wsp)
2533 {
2534 	return (txg_list_walk_init_common(wsp, 0, 0));
2535 }
2536 
2537 static int
2538 txg_list1_walk_init(mdb_walk_state_t *wsp)
2539 {
2540 	return (txg_list_walk_init_common(wsp, 1, 1));
2541 }
2542 
2543 static int
2544 txg_list2_walk_init(mdb_walk_state_t *wsp)
2545 {
2546 	return (txg_list_walk_init_common(wsp, 2, 2));
2547 }
2548 
2549 static int
2550 txg_list3_walk_init(mdb_walk_state_t *wsp)
2551 {
2552 	return (txg_list_walk_init_common(wsp, 3, 3));
2553 }
2554 
2555 static int
2556 txg_list_walk_step(mdb_walk_state_t *wsp)
2557 {
2558 	txg_list_walk_data_t *lwd = wsp->walk_data;
2559 	uintptr_t addr;
2560 	txg_node_t *node;
2561 	int status;
2562 
2563 	while (wsp->walk_addr == NULL && lwd->lw_txgoff < lwd->lw_maxoff) {
2564 		lwd->lw_txgoff++;
2565 		wsp->walk_addr = lwd->lw_head[lwd->lw_txgoff];
2566 	}
2567 
2568 	if (wsp->walk_addr == NULL)
2569 		return (WALK_DONE);
2570 
2571 	addr = wsp->walk_addr - lwd->lw_offset;
2572 
2573 	if (mdb_vread(lwd->lw_obj,
2574 	    lwd->lw_offset + sizeof (txg_node_t), addr) == -1) {
2575 		mdb_warn("failed to read list element at %#lx", addr);
2576 		return (WALK_ERR);
2577 	}
2578 
2579 	status = wsp->walk_callback(addr, lwd->lw_obj, wsp->walk_cbdata);
2580 	node = (txg_node_t *)((uintptr_t)lwd->lw_obj + lwd->lw_offset);
2581 	wsp->walk_addr = (uintptr_t)node->tn_next[lwd->lw_txgoff];
2582 
2583 	return (status);
2584 }
2585 
2586 /*
2587  * ::walk spa
2588  *
2589  * Walk all named spa_t structures in the namespace.  This is nothing more than
2590  * a layered avl walk.
2591  */
2592 static int
2593 spa_walk_init(mdb_walk_state_t *wsp)
2594 {
2595 	GElf_Sym sym;
2596 
2597 	if (wsp->walk_addr != NULL) {
2598 		mdb_warn("spa walk only supports global walks\n");
2599 		return (WALK_ERR);
2600 	}
2601 
2602 	if (mdb_lookup_by_obj(ZFS_OBJ_NAME, "spa_namespace_avl", &sym) == -1) {
2603 		mdb_warn("failed to find symbol 'spa_namespace_avl'");
2604 		return (WALK_ERR);
2605 	}
2606 
2607 	wsp->walk_addr = (uintptr_t)sym.st_value;
2608 
2609 	if (mdb_layered_walk("avl", wsp) == -1) {
2610 		mdb_warn("failed to walk 'avl'\n");
2611 		return (WALK_ERR);
2612 	}
2613 
2614 	return (WALK_NEXT);
2615 }
2616 
2617 static int
2618 spa_walk_step(mdb_walk_state_t *wsp)
2619 {
2620 	return (wsp->walk_callback(wsp->walk_addr, NULL, wsp->walk_cbdata));
2621 }
2622 
2623 /*
2624  * [addr]::walk zio
2625  *
2626  * Walk all active zio_t structures on the system.  This is simply a layered
2627  * walk on top of ::walk zio_cache, with the optional ability to limit the
2628  * structures to a particular pool.
2629  */
2630 static int
2631 zio_walk_init(mdb_walk_state_t *wsp)
2632 {
2633 	wsp->walk_data = (void *)wsp->walk_addr;
2634 
2635 	if (mdb_layered_walk("zio_cache", wsp) == -1) {
2636 		mdb_warn("failed to walk 'zio_cache'\n");
2637 		return (WALK_ERR);
2638 	}
2639 
2640 	return (WALK_NEXT);
2641 }
2642 
2643 static int
2644 zio_walk_step(mdb_walk_state_t *wsp)
2645 {
2646 	mdb_zio_t zio;
2647 	uintptr_t spa = (uintptr_t)wsp->walk_data;
2648 
2649 	if (mdb_ctf_vread(&zio, ZFS_STRUCT "zio", "mdb_zio_t",
2650 	    wsp->walk_addr, 0) == -1)
2651 		return (WALK_ERR);
2652 
2653 	if (spa != 0 && spa != zio.io_spa)
2654 		return (WALK_NEXT);
2655 
2656 	return (wsp->walk_callback(wsp->walk_addr, &zio, wsp->walk_cbdata));
2657 }
2658 
2659 /*
2660  * [addr]::walk zio_root
2661  *
2662  * Walk only root zio_t structures, optionally for a particular spa_t.
2663  */
2664 static int
2665 zio_walk_root_step(mdb_walk_state_t *wsp)
2666 {
2667 	mdb_zio_t zio;
2668 	uintptr_t spa = (uintptr_t)wsp->walk_data;
2669 
2670 	if (mdb_ctf_vread(&zio, ZFS_STRUCT "zio", "mdb_zio_t",
2671 	    wsp->walk_addr, 0) == -1)
2672 		return (WALK_ERR);
2673 
2674 	if (spa != 0 && spa != zio.io_spa)
2675 		return (WALK_NEXT);
2676 
2677 	/* If the parent list is not empty, ignore */
2678 	if (zio.io_parent_list.list_head.list_next !=
2679 	    wsp->walk_addr +
2680 	    mdb_ctf_offsetof_by_name(ZFS_STRUCT "zio", "io_parent_list") +
2681 	    mdb_ctf_offsetof_by_name("struct list", "list_head"))
2682 		return (WALK_NEXT);
2683 
2684 	return (wsp->walk_callback(wsp->walk_addr, &zio, wsp->walk_cbdata));
2685 }
2686 
2687 /*
2688  * ::zfs_blkstats
2689  *
2690  *	-v	print verbose per-level information
2691  *
2692  */
2693 static int
2694 zfs_blkstats(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
2695 {
2696 	boolean_t verbose = B_FALSE;
2697 	zfs_all_blkstats_t stats;
2698 	dmu_object_type_t t;
2699 	zfs_blkstat_t *tzb;
2700 	uint64_t ditto;
2701 	dmu_object_type_info_t dmu_ot[DMU_OT_NUMTYPES + 10];
2702 	/* +10 in case it grew */
2703 
2704 	if (mdb_readvar(&dmu_ot, "dmu_ot") == -1) {
2705 		mdb_warn("failed to read 'dmu_ot'");
2706 		return (DCMD_ERR);
2707 	}
2708 
2709 	if (mdb_getopts(argc, argv,
2710 	    'v', MDB_OPT_SETBITS, TRUE, &verbose,
2711 	    NULL) != argc)
2712 		return (DCMD_USAGE);
2713 
2714 	if (!(flags & DCMD_ADDRSPEC))
2715 		return (DCMD_USAGE);
2716 
2717 	if (GETMEMB(addr, "spa", spa_dsl_pool, addr) ||
2718 	    GETMEMB(addr, "dsl_pool", dp_blkstats, addr) ||
2719 	    mdb_vread(&stats, sizeof (zfs_all_blkstats_t), addr) == -1) {
2720 		mdb_warn("failed to read data at %p;", addr);
2721 		mdb_printf("maybe no stats? run \"zpool scrub\" first.");
2722 		return (DCMD_ERR);
2723 	}
2724 
2725 	tzb = &stats.zab_type[DN_MAX_LEVELS][DMU_OT_TOTAL];
2726 	if (tzb->zb_gangs != 0) {
2727 		mdb_printf("Ganged blocks: %llu\n",
2728 		    (longlong_t)tzb->zb_gangs);
2729 	}
2730 
2731 	ditto = tzb->zb_ditto_2_of_2_samevdev + tzb->zb_ditto_2_of_3_samevdev +
2732 	    tzb->zb_ditto_3_of_3_samevdev;
2733 	if (ditto != 0) {
2734 		mdb_printf("Dittoed blocks on same vdev: %llu\n",
2735 		    (longlong_t)ditto);
2736 	}
2737 
2738 	mdb_printf("\nBlocks\tLSIZE\tPSIZE\tASIZE"
2739 	    "\t  avg\t comp\t%%Total\tType\n");
2740 
2741 	for (t = 0; t <= DMU_OT_TOTAL; t++) {
2742 		char csize[NICENUM_BUFLEN], lsize[NICENUM_BUFLEN];
2743 		char psize[NICENUM_BUFLEN], asize[NICENUM_BUFLEN];
2744 		char avg[NICENUM_BUFLEN];
2745 		char comp[NICENUM_BUFLEN], pct[NICENUM_BUFLEN];
2746 		char typename[64];
2747 		int l;
2748 
2749 
2750 		if (t == DMU_OT_DEFERRED)
2751 			strcpy(typename, "deferred free");
2752 		else if (t == DMU_OT_OTHER)
2753 			strcpy(typename, "other");
2754 		else if (t == DMU_OT_TOTAL)
2755 			strcpy(typename, "Total");
2756 		else if (mdb_readstr(typename, sizeof (typename),
2757 		    (uintptr_t)dmu_ot[t].ot_name) == -1) {
2758 			mdb_warn("failed to read type name");
2759 			return (DCMD_ERR);
2760 		}
2761 
2762 		if (stats.zab_type[DN_MAX_LEVELS][t].zb_asize == 0)
2763 			continue;
2764 
2765 		for (l = -1; l < DN_MAX_LEVELS; l++) {
2766 			int level = (l == -1 ? DN_MAX_LEVELS : l);
2767 			zfs_blkstat_t *zb = &stats.zab_type[level][t];
2768 
2769 			if (zb->zb_asize == 0)
2770 				continue;
2771 
2772 			/*
2773 			 * Don't print each level unless requested.
2774 			 */
2775 			if (!verbose && level != DN_MAX_LEVELS)
2776 				continue;
2777 
2778 			/*
2779 			 * If all the space is level 0, don't print the
2780 			 * level 0 separately.
2781 			 */
2782 			if (level == 0 && zb->zb_asize ==
2783 			    stats.zab_type[DN_MAX_LEVELS][t].zb_asize)
2784 				continue;
2785 
2786 			mdb_nicenum(zb->zb_count, csize);
2787 			mdb_nicenum(zb->zb_lsize, lsize);
2788 			mdb_nicenum(zb->zb_psize, psize);
2789 			mdb_nicenum(zb->zb_asize, asize);
2790 			mdb_nicenum(zb->zb_asize / zb->zb_count, avg);
2791 			(void) snprintfrac(comp, NICENUM_BUFLEN,
2792 			    zb->zb_lsize, zb->zb_psize, 2);
2793 			(void) snprintfrac(pct, NICENUM_BUFLEN,
2794 			    100 * zb->zb_asize, tzb->zb_asize, 2);
2795 
2796 			mdb_printf("%6s\t%5s\t%5s\t%5s\t%5s"
2797 			    "\t%5s\t%6s\t",
2798 			    csize, lsize, psize, asize, avg, comp, pct);
2799 
2800 			if (level == DN_MAX_LEVELS)
2801 				mdb_printf("%s\n", typename);
2802 			else
2803 				mdb_printf("  L%d %s\n",
2804 				    level, typename);
2805 		}
2806 	}
2807 
2808 	return (DCMD_OK);
2809 }
2810 
2811 typedef struct mdb_reference {
2812 	uintptr_t ref_holder;
2813 	uintptr_t ref_removed;
2814 	uint64_t ref_number;
2815 } mdb_reference_t;
2816 
2817 /* ARGSUSED */
2818 static int
2819 reference_cb(uintptr_t addr, const void *ignored, void *arg)
2820 {
2821 	mdb_reference_t ref;
2822 	boolean_t holder_is_str = B_FALSE;
2823 	char holder_str[128];
2824 	boolean_t removed = (boolean_t)arg;
2825 
2826 	if (mdb_ctf_vread(&ref, "reference_t", "mdb_reference_t", addr,
2827 	    0) == -1)
2828 		return (DCMD_ERR);
2829 
2830 	if (mdb_readstr(holder_str, sizeof (holder_str),
2831 	    ref.ref_holder) != -1)
2832 		holder_is_str = strisprint(holder_str);
2833 
2834 	if (removed)
2835 		mdb_printf("removed ");
2836 	mdb_printf("reference ");
2837 	if (ref.ref_number != 1)
2838 		mdb_printf("with count=%llu ", ref.ref_number);
2839 	mdb_printf("with tag %lx", ref.ref_holder);
2840 	if (holder_is_str)
2841 		mdb_printf(" \"%s\"", holder_str);
2842 	mdb_printf(", held at:\n");
2843 
2844 	(void) mdb_call_dcmd("whatis", addr, DCMD_ADDRSPEC, 0, NULL);
2845 
2846 	if (removed) {
2847 		mdb_printf("removed at:\n");
2848 		(void) mdb_call_dcmd("whatis", ref.ref_removed,
2849 		    DCMD_ADDRSPEC, 0, NULL);
2850 	}
2851 
2852 	mdb_printf("\n");
2853 
2854 	return (WALK_NEXT);
2855 }
2856 
2857 typedef struct mdb_refcount {
2858 	uint64_t rc_count;
2859 } mdb_refcount_t;
2860 
2861 typedef struct mdb_refcount_removed {
2862 	uint64_t rc_removed_count;
2863 } mdb_refcount_removed_t;
2864 
2865 typedef struct mdb_refcount_tracked {
2866 	boolean_t rc_tracked;
2867 } mdb_refcount_tracked_t;
2868 
2869 /* ARGSUSED */
2870 static int
2871 refcount(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
2872 {
2873 	mdb_refcount_t rc;
2874 	mdb_refcount_removed_t rcr;
2875 	mdb_refcount_tracked_t rct;
2876 	int off;
2877 	boolean_t released = B_FALSE;
2878 
2879 	if (!(flags & DCMD_ADDRSPEC))
2880 		return (DCMD_USAGE);
2881 
2882 	if (mdb_getopts(argc, argv,
2883 	    'r', MDB_OPT_SETBITS, B_TRUE, &released,
2884 	    NULL) != argc)
2885 		return (DCMD_USAGE);
2886 
2887 	if (mdb_ctf_vread(&rc, "refcount_t", "mdb_refcount_t", addr,
2888 	    0) == -1)
2889 		return (DCMD_ERR);
2890 
2891 	if (mdb_ctf_vread(&rcr, "refcount_t", "mdb_refcount_removed_t", addr,
2892 	    MDB_CTF_VREAD_QUIET) == -1) {
2893 		mdb_printf("refcount_t at %p has %llu holds (untracked)\n",
2894 		    addr, (longlong_t)rc.rc_count);
2895 		return (DCMD_OK);
2896 	}
2897 
2898 	if (mdb_ctf_vread(&rct, "refcount_t", "mdb_refcount_tracked_t", addr,
2899 	    MDB_CTF_VREAD_QUIET) == -1) {
2900 		/* If this is an old target, it might be tracked. */
2901 		rct.rc_tracked = B_TRUE;
2902 	}
2903 
2904 	mdb_printf("refcount_t at %p has %llu current holds, "
2905 	    "%llu recently released holds\n",
2906 	    addr, (longlong_t)rc.rc_count, (longlong_t)rcr.rc_removed_count);
2907 
2908 	if (rct.rc_tracked && rc.rc_count > 0)
2909 		mdb_printf("current holds:\n");
2910 	off = mdb_ctf_offsetof_by_name("refcount_t", "rc_list");
2911 	if (off == -1)
2912 		return (DCMD_ERR);
2913 	mdb_pwalk("list", reference_cb, (void*)B_FALSE, addr + off);
2914 
2915 	if (released && rcr.rc_removed_count > 0) {
2916 		mdb_printf("released holds:\n");
2917 
2918 		off = mdb_ctf_offsetof_by_name("refcount_t", "rc_removed");
2919 		if (off == -1)
2920 			return (DCMD_ERR);
2921 		mdb_pwalk("list", reference_cb, (void*)B_TRUE, addr + off);
2922 	}
2923 
2924 	return (DCMD_OK);
2925 }
2926 
2927 /* ARGSUSED */
2928 static int
2929 sa_attr_table(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
2930 {
2931 	sa_attr_table_t *table;
2932 	sa_os_t sa_os;
2933 	char *name;
2934 	int i;
2935 
2936 	if (mdb_vread(&sa_os, sizeof (sa_os_t), addr) == -1) {
2937 		mdb_warn("failed to read sa_os at %p", addr);
2938 		return (DCMD_ERR);
2939 	}
2940 
2941 	table = mdb_alloc(sizeof (sa_attr_table_t) * sa_os.sa_num_attrs,
2942 	    UM_SLEEP | UM_GC);
2943 	name = mdb_alloc(MAXPATHLEN, UM_SLEEP | UM_GC);
2944 
2945 	if (mdb_vread(table, sizeof (sa_attr_table_t) * sa_os.sa_num_attrs,
2946 	    (uintptr_t)sa_os.sa_attr_table) == -1) {
2947 		mdb_warn("failed to read sa_os at %p", addr);
2948 		return (DCMD_ERR);
2949 	}
2950 
2951 	mdb_printf("%<u>%-10s %-10s %-10s %-10s %s%</u>\n",
2952 	    "ATTR ID", "REGISTERED", "LENGTH", "BSWAP", "NAME");
2953 	for (i = 0; i != sa_os.sa_num_attrs; i++) {
2954 		mdb_readstr(name, MAXPATHLEN, (uintptr_t)table[i].sa_name);
2955 		mdb_printf("%5x   %8x %8x %8x          %-s\n",
2956 		    (int)table[i].sa_attr, (int)table[i].sa_registered,
2957 		    (int)table[i].sa_length, table[i].sa_byteswap, name);
2958 	}
2959 
2960 	return (DCMD_OK);
2961 }
2962 
2963 static int
2964 sa_get_off_table(uintptr_t addr, uint32_t **off_tab, int attr_count)
2965 {
2966 	uintptr_t idx_table;
2967 
2968 	if (GETMEMB(addr, "sa_idx_tab", sa_idx_tab, idx_table)) {
2969 		mdb_printf("can't find offset table in sa_idx_tab\n");
2970 		return (-1);
2971 	}
2972 
2973 	*off_tab = mdb_alloc(attr_count * sizeof (uint32_t),
2974 	    UM_SLEEP | UM_GC);
2975 
2976 	if (mdb_vread(*off_tab,
2977 	    attr_count * sizeof (uint32_t), idx_table) == -1) {
2978 		mdb_warn("failed to attribute offset table %p", idx_table);
2979 		return (-1);
2980 	}
2981 
2982 	return (DCMD_OK);
2983 }
2984 
2985 /*ARGSUSED*/
2986 static int
2987 sa_attr_print(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
2988 {
2989 	uint32_t *offset_tab;
2990 	int attr_count;
2991 	uint64_t attr_id;
2992 	uintptr_t attr_addr;
2993 	uintptr_t bonus_tab, spill_tab;
2994 	uintptr_t db_bonus, db_spill;
2995 	uintptr_t os, os_sa;
2996 	uintptr_t db_data;
2997 
2998 	if (argc != 1)
2999 		return (DCMD_USAGE);
3000 
3001 	if (argv[0].a_type == MDB_TYPE_STRING)
3002 		attr_id = mdb_strtoull(argv[0].a_un.a_str);
3003 	else
3004 		return (DCMD_USAGE);
3005 
3006 	if (GETMEMB(addr, "sa_handle", sa_bonus_tab, bonus_tab) ||
3007 	    GETMEMB(addr, "sa_handle", sa_spill_tab, spill_tab) ||
3008 	    GETMEMB(addr, "sa_handle", sa_os, os) ||
3009 	    GETMEMB(addr, "sa_handle", sa_bonus, db_bonus) ||
3010 	    GETMEMB(addr, "sa_handle", sa_spill, db_spill)) {
3011 		mdb_printf("Can't find necessary information in sa_handle "
3012 		    "in sa_handle\n");
3013 		return (DCMD_ERR);
3014 	}
3015 
3016 	if (GETMEMB(os, "objset", os_sa, os_sa)) {
3017 		mdb_printf("Can't find os_sa in objset\n");
3018 		return (DCMD_ERR);
3019 	}
3020 
3021 	if (GETMEMB(os_sa, "sa_os", sa_num_attrs, attr_count)) {
3022 		mdb_printf("Can't find sa_num_attrs\n");
3023 		return (DCMD_ERR);
3024 	}
3025 
3026 	if (attr_id > attr_count) {
3027 		mdb_printf("attribute id number is out of range\n");
3028 		return (DCMD_ERR);
3029 	}
3030 
3031 	if (bonus_tab) {
3032 		if (sa_get_off_table(bonus_tab, &offset_tab,
3033 		    attr_count) == -1) {
3034 			return (DCMD_ERR);
3035 		}
3036 
3037 		if (GETMEMB(db_bonus, "dmu_buf", db_data, db_data)) {
3038 			mdb_printf("can't find db_data in bonus dbuf\n");
3039 			return (DCMD_ERR);
3040 		}
3041 	}
3042 
3043 	if (bonus_tab && !TOC_ATTR_PRESENT(offset_tab[attr_id]) &&
3044 	    spill_tab == NULL) {
3045 		mdb_printf("Attribute does not exist\n");
3046 		return (DCMD_ERR);
3047 	} else if (!TOC_ATTR_PRESENT(offset_tab[attr_id]) && spill_tab) {
3048 		if (sa_get_off_table(spill_tab, &offset_tab,
3049 		    attr_count) == -1) {
3050 			return (DCMD_ERR);
3051 		}
3052 		if (GETMEMB(db_spill, "dmu_buf", db_data, db_data)) {
3053 			mdb_printf("can't find db_data in spill dbuf\n");
3054 			return (DCMD_ERR);
3055 		}
3056 		if (!TOC_ATTR_PRESENT(offset_tab[attr_id])) {
3057 			mdb_printf("Attribute does not exist\n");
3058 			return (DCMD_ERR);
3059 		}
3060 	}
3061 	attr_addr = db_data + TOC_OFF(offset_tab[attr_id]);
3062 	mdb_printf("%p\n", attr_addr);
3063 	return (DCMD_OK);
3064 }
3065 
3066 /* ARGSUSED */
3067 static int
3068 zfs_ace_print_common(uintptr_t addr, uint_t flags,
3069     uint64_t id, uint32_t access_mask, uint16_t ace_flags,
3070     uint16_t ace_type, int verbose)
3071 {
3072 	if (DCMD_HDRSPEC(flags) && !verbose)
3073 		mdb_printf("%<u>%-?s %-8s %-8s %-8s %s%</u>\n",
3074 		    "ADDR", "FLAGS", "MASK", "TYPE", "ID");
3075 
3076 	if (!verbose) {
3077 		mdb_printf("%0?p %-8x %-8x %-8x %-llx\n", addr,
3078 		    ace_flags, access_mask, ace_type, id);
3079 		return (DCMD_OK);
3080 	}
3081 
3082 	switch (ace_flags & ACE_TYPE_FLAGS) {
3083 	case ACE_OWNER:
3084 		mdb_printf("owner@:");
3085 		break;
3086 	case (ACE_IDENTIFIER_GROUP | ACE_GROUP):
3087 		mdb_printf("group@:");
3088 		break;
3089 	case ACE_EVERYONE:
3090 		mdb_printf("everyone@:");
3091 		break;
3092 	case ACE_IDENTIFIER_GROUP:
3093 		mdb_printf("group:%llx:", (u_longlong_t)id);
3094 		break;
3095 	case 0: /* User entry */
3096 		mdb_printf("user:%llx:", (u_longlong_t)id);
3097 		break;
3098 	}
3099 
3100 	/* print out permission mask */
3101 	if (access_mask & ACE_READ_DATA)
3102 		mdb_printf("r");
3103 	else
3104 		mdb_printf("-");
3105 	if (access_mask & ACE_WRITE_DATA)
3106 		mdb_printf("w");
3107 	else
3108 		mdb_printf("-");
3109 	if (access_mask & ACE_EXECUTE)
3110 		mdb_printf("x");
3111 	else
3112 		mdb_printf("-");
3113 	if (access_mask & ACE_APPEND_DATA)
3114 		mdb_printf("p");
3115 	else
3116 		mdb_printf("-");
3117 	if (access_mask & ACE_DELETE)
3118 		mdb_printf("d");
3119 	else
3120 		mdb_printf("-");
3121 	if (access_mask & ACE_DELETE_CHILD)
3122 		mdb_printf("D");
3123 	else
3124 		mdb_printf("-");
3125 	if (access_mask & ACE_READ_ATTRIBUTES)
3126 		mdb_printf("a");
3127 	else
3128 		mdb_printf("-");
3129 	if (access_mask & ACE_WRITE_ATTRIBUTES)
3130 		mdb_printf("A");
3131 	else
3132 		mdb_printf("-");
3133 	if (access_mask & ACE_READ_NAMED_ATTRS)
3134 		mdb_printf("R");
3135 	else
3136 		mdb_printf("-");
3137 	if (access_mask & ACE_WRITE_NAMED_ATTRS)
3138 		mdb_printf("W");
3139 	else
3140 		mdb_printf("-");
3141 	if (access_mask & ACE_READ_ACL)
3142 		mdb_printf("c");
3143 	else
3144 		mdb_printf("-");
3145 	if (access_mask & ACE_WRITE_ACL)
3146 		mdb_printf("C");
3147 	else
3148 		mdb_printf("-");
3149 	if (access_mask & ACE_WRITE_OWNER)
3150 		mdb_printf("o");
3151 	else
3152 		mdb_printf("-");
3153 	if (access_mask & ACE_SYNCHRONIZE)
3154 		mdb_printf("s");
3155 	else
3156 		mdb_printf("-");
3157 
3158 	mdb_printf(":");
3159 
3160 	/* Print out inheritance flags */
3161 	if (ace_flags & ACE_FILE_INHERIT_ACE)
3162 		mdb_printf("f");
3163 	else
3164 		mdb_printf("-");
3165 	if (ace_flags & ACE_DIRECTORY_INHERIT_ACE)
3166 		mdb_printf("d");
3167 	else
3168 		mdb_printf("-");
3169 	if (ace_flags & ACE_INHERIT_ONLY_ACE)
3170 		mdb_printf("i");
3171 	else
3172 		mdb_printf("-");
3173 	if (ace_flags & ACE_NO_PROPAGATE_INHERIT_ACE)
3174 		mdb_printf("n");
3175 	else
3176 		mdb_printf("-");
3177 	if (ace_flags & ACE_SUCCESSFUL_ACCESS_ACE_FLAG)
3178 		mdb_printf("S");
3179 	else
3180 		mdb_printf("-");
3181 	if (ace_flags & ACE_FAILED_ACCESS_ACE_FLAG)
3182 		mdb_printf("F");
3183 	else
3184 		mdb_printf("-");
3185 	if (ace_flags & ACE_INHERITED_ACE)
3186 		mdb_printf("I");
3187 	else
3188 		mdb_printf("-");
3189 
3190 	switch (ace_type) {
3191 	case ACE_ACCESS_ALLOWED_ACE_TYPE:
3192 		mdb_printf(":allow\n");
3193 		break;
3194 	case ACE_ACCESS_DENIED_ACE_TYPE:
3195 		mdb_printf(":deny\n");
3196 		break;
3197 	case ACE_SYSTEM_AUDIT_ACE_TYPE:
3198 		mdb_printf(":audit\n");
3199 		break;
3200 	case ACE_SYSTEM_ALARM_ACE_TYPE:
3201 		mdb_printf(":alarm\n");
3202 		break;
3203 	default:
3204 		mdb_printf(":?\n");
3205 	}
3206 	return (DCMD_OK);
3207 }
3208 
3209 /* ARGSUSED */
3210 static int
3211 zfs_ace_print(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
3212 {
3213 	zfs_ace_t zace;
3214 	int verbose = FALSE;
3215 	uint64_t id;
3216 
3217 	if (!(flags & DCMD_ADDRSPEC))
3218 		return (DCMD_USAGE);
3219 
3220 	if (mdb_getopts(argc, argv,
3221 	    'v', MDB_OPT_SETBITS, TRUE, &verbose, TRUE, NULL) != argc)
3222 		return (DCMD_USAGE);
3223 
3224 	if (mdb_vread(&zace, sizeof (zfs_ace_t), addr) == -1) {
3225 		mdb_warn("failed to read zfs_ace_t");
3226 		return (DCMD_ERR);
3227 	}
3228 
3229 	if ((zace.z_hdr.z_flags & ACE_TYPE_FLAGS) == 0 ||
3230 	    (zace.z_hdr.z_flags & ACE_TYPE_FLAGS) == ACE_IDENTIFIER_GROUP)
3231 		id = zace.z_fuid;
3232 	else
3233 		id = -1;
3234 
3235 	return (zfs_ace_print_common(addr, flags, id, zace.z_hdr.z_access_mask,
3236 	    zace.z_hdr.z_flags, zace.z_hdr.z_type, verbose));
3237 }
3238 
3239 /* ARGSUSED */
3240 static int
3241 zfs_ace0_print(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
3242 {
3243 	ace_t ace;
3244 	uint64_t id;
3245 	int verbose = FALSE;
3246 
3247 	if (!(flags & DCMD_ADDRSPEC))
3248 		return (DCMD_USAGE);
3249 
3250 	if (mdb_getopts(argc, argv,
3251 	    'v', MDB_OPT_SETBITS, TRUE, &verbose, TRUE, NULL) != argc)
3252 		return (DCMD_USAGE);
3253 
3254 	if (mdb_vread(&ace, sizeof (ace_t), addr) == -1) {
3255 		mdb_warn("failed to read ace_t");
3256 		return (DCMD_ERR);
3257 	}
3258 
3259 	if ((ace.a_flags & ACE_TYPE_FLAGS) == 0 ||
3260 	    (ace.a_flags & ACE_TYPE_FLAGS) == ACE_IDENTIFIER_GROUP)
3261 		id = ace.a_who;
3262 	else
3263 		id = -1;
3264 
3265 	return (zfs_ace_print_common(addr, flags, id, ace.a_access_mask,
3266 	    ace.a_flags, ace.a_type, verbose));
3267 }
3268 
3269 typedef struct acl_dump_args {
3270 	int a_argc;
3271 	const mdb_arg_t *a_argv;
3272 	uint16_t a_version;
3273 	int a_flags;
3274 } acl_dump_args_t;
3275 
3276 /* ARGSUSED */
3277 static int
3278 acl_aces_cb(uintptr_t addr, const void *unknown, void *arg)
3279 {
3280 	acl_dump_args_t *acl_args = (acl_dump_args_t *)arg;
3281 
3282 	if (acl_args->a_version == 1) {
3283 		if (mdb_call_dcmd("zfs_ace", addr,
3284 		    DCMD_ADDRSPEC|acl_args->a_flags, acl_args->a_argc,
3285 		    acl_args->a_argv) != DCMD_OK) {
3286 			return (WALK_ERR);
3287 		}
3288 	} else {
3289 		if (mdb_call_dcmd("zfs_ace0", addr,
3290 		    DCMD_ADDRSPEC|acl_args->a_flags, acl_args->a_argc,
3291 		    acl_args->a_argv) != DCMD_OK) {
3292 			return (WALK_ERR);
3293 		}
3294 	}
3295 	acl_args->a_flags = DCMD_LOOP;
3296 	return (WALK_NEXT);
3297 }
3298 
3299 /* ARGSUSED */
3300 static int
3301 acl_cb(uintptr_t addr, const void *unknown, void *arg)
3302 {
3303 	acl_dump_args_t *acl_args = (acl_dump_args_t *)arg;
3304 
3305 	if (acl_args->a_version == 1) {
3306 		if (mdb_pwalk("zfs_acl_node_aces", acl_aces_cb,
3307 		    arg, addr) != 0) {
3308 			mdb_warn("can't walk ACEs");
3309 			return (DCMD_ERR);
3310 		}
3311 	} else {
3312 		if (mdb_pwalk("zfs_acl_node_aces0", acl_aces_cb,
3313 		    arg, addr) != 0) {
3314 			mdb_warn("can't walk ACEs");
3315 			return (DCMD_ERR);
3316 		}
3317 	}
3318 	return (WALK_NEXT);
3319 }
3320 
3321 /* ARGSUSED */
3322 static int
3323 zfs_acl_dump(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
3324 {
3325 	zfs_acl_t zacl;
3326 	int verbose = FALSE;
3327 	acl_dump_args_t acl_args;
3328 
3329 	if (!(flags & DCMD_ADDRSPEC))
3330 		return (DCMD_USAGE);
3331 
3332 	if (mdb_getopts(argc, argv,
3333 	    'v', MDB_OPT_SETBITS, TRUE, &verbose, TRUE, NULL) != argc)
3334 		return (DCMD_USAGE);
3335 
3336 	if (mdb_vread(&zacl, sizeof (zfs_acl_t), addr) == -1) {
3337 		mdb_warn("failed to read zfs_acl_t");
3338 		return (DCMD_ERR);
3339 	}
3340 
3341 	acl_args.a_argc = argc;
3342 	acl_args.a_argv = argv;
3343 	acl_args.a_version = zacl.z_version;
3344 	acl_args.a_flags = DCMD_LOOPFIRST;
3345 
3346 	if (mdb_pwalk("zfs_acl_node", acl_cb, &acl_args, addr) != 0) {
3347 		mdb_warn("can't walk ACL");
3348 		return (DCMD_ERR);
3349 	}
3350 
3351 	return (DCMD_OK);
3352 }
3353 
3354 /* ARGSUSED */
3355 static int
3356 zfs_acl_node_walk_init(mdb_walk_state_t *wsp)
3357 {
3358 	if (wsp->walk_addr == NULL) {
3359 		mdb_warn("must supply address of zfs_acl_node_t\n");
3360 		return (WALK_ERR);
3361 	}
3362 
3363 	wsp->walk_addr +=
3364 	    mdb_ctf_offsetof_by_name(ZFS_STRUCT "zfs_acl", "z_acl");
3365 
3366 	if (mdb_layered_walk("list", wsp) == -1) {
3367 		mdb_warn("failed to walk 'list'\n");
3368 		return (WALK_ERR);
3369 	}
3370 
3371 	return (WALK_NEXT);
3372 }
3373 
3374 static int
3375 zfs_acl_node_walk_step(mdb_walk_state_t *wsp)
3376 {
3377 	zfs_acl_node_t	aclnode;
3378 
3379 	if (mdb_vread(&aclnode, sizeof (zfs_acl_node_t),
3380 	    wsp->walk_addr) == -1) {
3381 		mdb_warn("failed to read zfs_acl_node at %p", wsp->walk_addr);
3382 		return (WALK_ERR);
3383 	}
3384 
3385 	return (wsp->walk_callback(wsp->walk_addr, &aclnode, wsp->walk_cbdata));
3386 }
3387 
3388 typedef struct ace_walk_data {
3389 	int		ace_count;
3390 	int		ace_version;
3391 } ace_walk_data_t;
3392 
3393 static int
3394 zfs_aces_walk_init_common(mdb_walk_state_t *wsp, int version,
3395     int ace_count, uintptr_t ace_data)
3396 {
3397 	ace_walk_data_t *ace_walk_data;
3398 
3399 	if (wsp->walk_addr == NULL) {
3400 		mdb_warn("must supply address of zfs_acl_node_t\n");
3401 		return (WALK_ERR);
3402 	}
3403 
3404 	ace_walk_data = mdb_alloc(sizeof (ace_walk_data_t), UM_SLEEP | UM_GC);
3405 
3406 	ace_walk_data->ace_count = ace_count;
3407 	ace_walk_data->ace_version = version;
3408 
3409 	wsp->walk_addr = ace_data;
3410 	wsp->walk_data = ace_walk_data;
3411 
3412 	return (WALK_NEXT);
3413 }
3414 
3415 static int
3416 zfs_acl_node_aces_walk_init_common(mdb_walk_state_t *wsp, int version)
3417 {
3418 	static int gotid;
3419 	static mdb_ctf_id_t acl_id;
3420 	int z_ace_count;
3421 	uintptr_t z_acldata;
3422 
3423 	if (!gotid) {
3424 		if (mdb_ctf_lookup_by_name("struct zfs_acl_node",
3425 		    &acl_id) == -1) {
3426 			mdb_warn("couldn't find struct zfs_acl_node");
3427 			return (DCMD_ERR);
3428 		}
3429 		gotid = TRUE;
3430 	}
3431 
3432 	if (GETMEMBID(wsp->walk_addr, &acl_id, z_ace_count, z_ace_count)) {
3433 		return (DCMD_ERR);
3434 	}
3435 	if (GETMEMBID(wsp->walk_addr, &acl_id, z_acldata, z_acldata)) {
3436 		return (DCMD_ERR);
3437 	}
3438 
3439 	return (zfs_aces_walk_init_common(wsp, version,
3440 	    z_ace_count, z_acldata));
3441 }
3442 
3443 /* ARGSUSED */
3444 static int
3445 zfs_acl_node_aces_walk_init(mdb_walk_state_t *wsp)
3446 {
3447 	return (zfs_acl_node_aces_walk_init_common(wsp, 1));
3448 }
3449 
3450 /* ARGSUSED */
3451 static int
3452 zfs_acl_node_aces0_walk_init(mdb_walk_state_t *wsp)
3453 {
3454 	return (zfs_acl_node_aces_walk_init_common(wsp, 0));
3455 }
3456 
3457 static int
3458 zfs_aces_walk_step(mdb_walk_state_t *wsp)
3459 {
3460 	ace_walk_data_t *ace_data = wsp->walk_data;
3461 	zfs_ace_t zace;
3462 	ace_t *acep;
3463 	int status;
3464 	int entry_type;
3465 	int allow_type;
3466 	uintptr_t ptr;
3467 
3468 	if (ace_data->ace_count == 0)
3469 		return (WALK_DONE);
3470 
3471 	if (mdb_vread(&zace, sizeof (zfs_ace_t), wsp->walk_addr) == -1) {
3472 		mdb_warn("failed to read zfs_ace_t at %#lx",
3473 		    wsp->walk_addr);
3474 		return (WALK_ERR);
3475 	}
3476 
3477 	switch (ace_data->ace_version) {
3478 	case 0:
3479 		acep = (ace_t *)&zace;
3480 		entry_type = acep->a_flags & ACE_TYPE_FLAGS;
3481 		allow_type = acep->a_type;
3482 		break;
3483 	case 1:
3484 		entry_type = zace.z_hdr.z_flags & ACE_TYPE_FLAGS;
3485 		allow_type = zace.z_hdr.z_type;
3486 		break;
3487 	default:
3488 		return (WALK_ERR);
3489 	}
3490 
3491 	ptr = (uintptr_t)wsp->walk_addr;
3492 	switch (entry_type) {
3493 	case ACE_OWNER:
3494 	case ACE_EVERYONE:
3495 	case (ACE_IDENTIFIER_GROUP | ACE_GROUP):
3496 		ptr += ace_data->ace_version == 0 ?
3497 		    sizeof (ace_t) : sizeof (zfs_ace_hdr_t);
3498 		break;
3499 	case ACE_IDENTIFIER_GROUP:
3500 	default:
3501 		switch (allow_type) {
3502 		case ACE_ACCESS_ALLOWED_OBJECT_ACE_TYPE:
3503 		case ACE_ACCESS_DENIED_OBJECT_ACE_TYPE:
3504 		case ACE_SYSTEM_AUDIT_OBJECT_ACE_TYPE:
3505 		case ACE_SYSTEM_ALARM_OBJECT_ACE_TYPE:
3506 			ptr += ace_data->ace_version == 0 ?
3507 			    sizeof (ace_t) : sizeof (zfs_object_ace_t);
3508 			break;
3509 		default:
3510 			ptr += ace_data->ace_version == 0 ?
3511 			    sizeof (ace_t) : sizeof (zfs_ace_t);
3512 			break;
3513 		}
3514 	}
3515 
3516 	ace_data->ace_count--;
3517 	status = wsp->walk_callback(wsp->walk_addr,
3518 	    (void *)(uintptr_t)&zace, wsp->walk_cbdata);
3519 
3520 	wsp->walk_addr = ptr;
3521 	return (status);
3522 }
3523 
3524 typedef struct mdb_zfs_rrwlock {
3525 	uintptr_t	rr_writer;
3526 	boolean_t	rr_writer_wanted;
3527 } mdb_zfs_rrwlock_t;
3528 
3529 static uint_t rrw_key;
3530 
3531 /* ARGSUSED */
3532 static int
3533 rrwlock(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
3534 {
3535 	mdb_zfs_rrwlock_t rrw;
3536 
3537 	if (rrw_key == 0) {
3538 		if (mdb_ctf_readsym(&rrw_key, "uint_t", "rrw_tsd_key", 0) == -1)
3539 			return (DCMD_ERR);
3540 	}
3541 
3542 	if (mdb_ctf_vread(&rrw, "rrwlock_t", "mdb_zfs_rrwlock_t", addr,
3543 	    0) == -1)
3544 		return (DCMD_ERR);
3545 
3546 	if (rrw.rr_writer != 0) {
3547 		mdb_printf("write lock held by thread %lx\n", rrw.rr_writer);
3548 		return (DCMD_OK);
3549 	}
3550 
3551 	if (rrw.rr_writer_wanted) {
3552 		mdb_printf("writer wanted\n");
3553 	}
3554 
3555 	mdb_printf("anonymous references:\n");
3556 	(void) mdb_call_dcmd("refcount", addr +
3557 	    mdb_ctf_offsetof_by_name(ZFS_STRUCT "rrwlock", "rr_anon_rcount"),
3558 	    DCMD_ADDRSPEC, 0, NULL);
3559 
3560 	mdb_printf("linked references:\n");
3561 	(void) mdb_call_dcmd("refcount", addr +
3562 	    mdb_ctf_offsetof_by_name(ZFS_STRUCT "rrwlock", "rr_linked_rcount"),
3563 	    DCMD_ADDRSPEC, 0, NULL);
3564 
3565 	/*
3566 	 * XXX This should find references from
3567 	 * "::walk thread | ::tsd -v <rrw_key>", but there is no support
3568 	 * for programmatic consumption of dcmds, so this would be
3569 	 * difficult, potentially requiring reimplementing ::tsd (both
3570 	 * user and kernel versions) in this MDB module.
3571 	 */
3572 
3573 	return (DCMD_OK);
3574 }
3575 
3576 typedef struct mdb_arc_buf_hdr_t {
3577 	uint16_t b_psize;
3578 	uint16_t b_lsize;
3579 	struct {
3580 		uint32_t	b_bufcnt;
3581 		uintptr_t	b_state;
3582 	} b_l1hdr;
3583 } mdb_arc_buf_hdr_t;
3584 
3585 enum arc_cflags {
3586 	ARC_CFLAG_VERBOSE		= 1 << 0,
3587 	ARC_CFLAG_ANON			= 1 << 1,
3588 	ARC_CFLAG_MRU			= 1 << 2,
3589 	ARC_CFLAG_MFU			= 1 << 3,
3590 	ARC_CFLAG_BUFS			= 1 << 4,
3591 };
3592 
3593 typedef struct arc_compression_stats_data {
3594 	GElf_Sym anon_sym;	/* ARC_anon symbol */
3595 	GElf_Sym mru_sym;	/* ARC_mru symbol */
3596 	GElf_Sym mrug_sym;	/* ARC_mru_ghost symbol */
3597 	GElf_Sym mfu_sym;	/* ARC_mfu symbol */
3598 	GElf_Sym mfug_sym;	/* ARC_mfu_ghost symbol */
3599 	GElf_Sym l2c_sym;	/* ARC_l2c_only symbol */
3600 	uint64_t *anon_c_hist;	/* histogram of compressed sizes in anon */
3601 	uint64_t *anon_u_hist;	/* histogram of uncompressed sizes in anon */
3602 	uint64_t *anon_bufs;	/* histogram of buffer counts in anon state */
3603 	uint64_t *mru_c_hist;	/* histogram of compressed sizes in mru */
3604 	uint64_t *mru_u_hist;	/* histogram of uncompressed sizes in mru */
3605 	uint64_t *mru_bufs;	/* histogram of buffer counts in mru */
3606 	uint64_t *mfu_c_hist;	/* histogram of compressed sizes in mfu */
3607 	uint64_t *mfu_u_hist;	/* histogram of uncompressed sizes in mfu */
3608 	uint64_t *mfu_bufs;	/* histogram of buffer counts in mfu */
3609 	uint64_t *all_c_hist;	/* histogram of compressed anon + mru + mfu */
3610 	uint64_t *all_u_hist;	/* histogram of uncompressed anon + mru + mfu */
3611 	uint64_t *all_bufs;	/* histogram of buffer counts in all states  */
3612 	int arc_cflags;		/* arc compression flags, specified by user */
3613 	int hist_nbuckets;	/* number of buckets in each histogram */
3614 } arc_compression_stats_data_t;
3615 
3616 int
3617 highbit64(uint64_t i)
3618 {
3619 	int h = 1;
3620 
3621 	if (i == 0)
3622 		return (0);
3623 	if (i & 0xffffffff00000000ULL) {
3624 		h += 32; i >>= 32;
3625 	}
3626 	if (i & 0xffff0000) {
3627 		h += 16; i >>= 16;
3628 	}
3629 	if (i & 0xff00) {
3630 		h += 8; i >>= 8;
3631 	}
3632 	if (i & 0xf0) {
3633 		h += 4; i >>= 4;
3634 	}
3635 	if (i & 0xc) {
3636 		h += 2; i >>= 2;
3637 	}
3638 	if (i & 0x2) {
3639 		h += 1;
3640 	}
3641 	return (h);
3642 }
3643 
3644 /* ARGSUSED */
3645 static int
3646 arc_compression_stats_cb(uintptr_t addr, const void *unknown, void *arg)
3647 {
3648 	arc_compression_stats_data_t *data = arg;
3649 	mdb_arc_buf_hdr_t hdr;
3650 	int cbucket, ubucket, bufcnt;
3651 
3652 	if (mdb_ctf_vread(&hdr, "arc_buf_hdr_t", "mdb_arc_buf_hdr_t",
3653 	    addr, 0) == -1) {
3654 		return (WALK_ERR);
3655 	}
3656 
3657 	/*
3658 	 * Headers in the ghost states, or the l2c_only state don't have
3659 	 * arc buffers linked off of them. Thus, their compressed size
3660 	 * is meaningless, so we skip these from the stats.
3661 	 */
3662 	if (hdr.b_l1hdr.b_state == data->mrug_sym.st_value ||
3663 	    hdr.b_l1hdr.b_state == data->mfug_sym.st_value ||
3664 	    hdr.b_l1hdr.b_state == data->l2c_sym.st_value) {
3665 		return (WALK_NEXT);
3666 	}
3667 
3668 	/*
3669 	 * The physical size (compressed) and logical size
3670 	 * (uncompressed) are in units of SPA_MINBLOCKSIZE. By default,
3671 	 * we use the log2 of this value (rounded down to the nearest
3672 	 * integer) to determine the bucket to assign this header to.
3673 	 * Thus, the histogram is logarithmic with respect to the size
3674 	 * of the header. For example, the following is a mapping of the
3675 	 * bucket numbers and the range of header sizes they correspond to:
3676 	 *
3677 	 *	0: 0 byte headers
3678 	 *	1: 512 byte headers
3679 	 *	2: [1024 - 2048) byte headers
3680 	 *	3: [2048 - 4096) byte headers
3681 	 *	4: [4096 - 8192) byte headers
3682 	 *	5: [8192 - 16394) byte headers
3683 	 *	6: [16384 - 32768) byte headers
3684 	 *	7: [32768 - 65536) byte headers
3685 	 *	8: [65536 - 131072) byte headers
3686 	 *	9: 131072 byte headers
3687 	 *
3688 	 * If the ARC_CFLAG_VERBOSE flag was specified, we use the
3689 	 * physical and logical sizes directly. Thus, the histogram will
3690 	 * no longer be logarithmic; instead it will be linear with
3691 	 * respect to the size of the header. The following is a mapping
3692 	 * of the first many bucket numbers and the header size they
3693 	 * correspond to:
3694 	 *
3695 	 *	0: 0 byte headers
3696 	 *	1: 512 byte headers
3697 	 *	2: 1024 byte headers
3698 	 *	3: 1536 byte headers
3699 	 *	4: 2048 byte headers
3700 	 *	5: 2560 byte headers
3701 	 *	6: 3072 byte headers
3702 	 *
3703 	 * And so on. Keep in mind that a range of sizes isn't used in
3704 	 * the case of linear scale because the headers can only
3705 	 * increment or decrement in sizes of 512 bytes. So, it's not
3706 	 * possible for a header to be sized in between whats listed
3707 	 * above.
3708 	 *
3709 	 * Also, the above mapping values were calculated assuming a
3710 	 * SPA_MINBLOCKSHIFT of 512 bytes and a SPA_MAXBLOCKSIZE of 128K.
3711 	 */
3712 
3713 	if (data->arc_cflags & ARC_CFLAG_VERBOSE) {
3714 		cbucket = hdr.b_psize;
3715 		ubucket = hdr.b_lsize;
3716 	} else {
3717 		cbucket = highbit64(hdr.b_psize);
3718 		ubucket = highbit64(hdr.b_lsize);
3719 	}
3720 
3721 	bufcnt = hdr.b_l1hdr.b_bufcnt;
3722 	if (bufcnt >= data->hist_nbuckets)
3723 		bufcnt = data->hist_nbuckets - 1;
3724 
3725 	/* Ensure we stay within the bounds of the histogram array */
3726 	ASSERT3U(cbucket, <, data->hist_nbuckets);
3727 	ASSERT3U(ubucket, <, data->hist_nbuckets);
3728 
3729 	if (hdr.b_l1hdr.b_state == data->anon_sym.st_value) {
3730 		data->anon_c_hist[cbucket]++;
3731 		data->anon_u_hist[ubucket]++;
3732 		data->anon_bufs[bufcnt]++;
3733 	} else if (hdr.b_l1hdr.b_state == data->mru_sym.st_value) {
3734 		data->mru_c_hist[cbucket]++;
3735 		data->mru_u_hist[ubucket]++;
3736 		data->mru_bufs[bufcnt]++;
3737 	} else if (hdr.b_l1hdr.b_state == data->mfu_sym.st_value) {
3738 		data->mfu_c_hist[cbucket]++;
3739 		data->mfu_u_hist[ubucket]++;
3740 		data->mfu_bufs[bufcnt]++;
3741 	}
3742 
3743 	data->all_c_hist[cbucket]++;
3744 	data->all_u_hist[ubucket]++;
3745 	data->all_bufs[bufcnt]++;
3746 
3747 	return (WALK_NEXT);
3748 }
3749 
3750 /* ARGSUSED */
3751 static int
3752 arc_compression_stats(uintptr_t addr, uint_t flags, int argc,
3753     const mdb_arg_t *argv)
3754 {
3755 	arc_compression_stats_data_t data = { 0 };
3756 	unsigned int max_shifted = SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT;
3757 	unsigned int hist_size;
3758 	char range[32];
3759 	int rc = DCMD_OK;
3760 
3761 	if (mdb_getopts(argc, argv,
3762 	    'v', MDB_OPT_SETBITS, ARC_CFLAG_VERBOSE, &data.arc_cflags,
3763 	    'a', MDB_OPT_SETBITS, ARC_CFLAG_ANON, &data.arc_cflags,
3764 	    'b', MDB_OPT_SETBITS, ARC_CFLAG_BUFS, &data.arc_cflags,
3765 	    'r', MDB_OPT_SETBITS, ARC_CFLAG_MRU, &data.arc_cflags,
3766 	    'f', MDB_OPT_SETBITS, ARC_CFLAG_MFU, &data.arc_cflags) != argc)
3767 		return (DCMD_USAGE);
3768 
3769 	if (mdb_lookup_by_obj(ZFS_OBJ_NAME, "ARC_anon", &data.anon_sym) ||
3770 	    mdb_lookup_by_obj(ZFS_OBJ_NAME, "ARC_mru", &data.mru_sym) ||
3771 	    mdb_lookup_by_obj(ZFS_OBJ_NAME, "ARC_mru_ghost", &data.mrug_sym) ||
3772 	    mdb_lookup_by_obj(ZFS_OBJ_NAME, "ARC_mfu", &data.mfu_sym) ||
3773 	    mdb_lookup_by_obj(ZFS_OBJ_NAME, "ARC_mfu_ghost", &data.mfug_sym) ||
3774 	    mdb_lookup_by_obj(ZFS_OBJ_NAME, "ARC_l2c_only", &data.l2c_sym)) {
3775 		mdb_warn("can't find arc state symbol");
3776 		return (DCMD_ERR);
3777 	}
3778 
3779 	/*
3780 	 * Determine the maximum expected size for any header, and use
3781 	 * this to determine the number of buckets needed for each
3782 	 * histogram. If ARC_CFLAG_VERBOSE is specified, this value is
3783 	 * used directly; otherwise the log2 of the maximum size is
3784 	 * used. Thus, if using a log2 scale there's a maximum of 10
3785 	 * possible buckets, while the linear scale (when using
3786 	 * ARC_CFLAG_VERBOSE) has a maximum of 257 buckets.
3787 	 */
3788 	if (data.arc_cflags & ARC_CFLAG_VERBOSE)
3789 		data.hist_nbuckets = max_shifted + 1;
3790 	else
3791 		data.hist_nbuckets = highbit64(max_shifted) + 1;
3792 
3793 	hist_size = sizeof (uint64_t) * data.hist_nbuckets;
3794 
3795 	data.anon_c_hist = mdb_zalloc(hist_size, UM_SLEEP);
3796 	data.anon_u_hist = mdb_zalloc(hist_size, UM_SLEEP);
3797 	data.anon_bufs = mdb_zalloc(hist_size, UM_SLEEP);
3798 
3799 	data.mru_c_hist = mdb_zalloc(hist_size, UM_SLEEP);
3800 	data.mru_u_hist = mdb_zalloc(hist_size, UM_SLEEP);
3801 	data.mru_bufs = mdb_zalloc(hist_size, UM_SLEEP);
3802 
3803 	data.mfu_c_hist = mdb_zalloc(hist_size, UM_SLEEP);
3804 	data.mfu_u_hist = mdb_zalloc(hist_size, UM_SLEEP);
3805 	data.mfu_bufs = mdb_zalloc(hist_size, UM_SLEEP);
3806 
3807 	data.all_c_hist = mdb_zalloc(hist_size, UM_SLEEP);
3808 	data.all_u_hist = mdb_zalloc(hist_size, UM_SLEEP);
3809 	data.all_bufs = mdb_zalloc(hist_size, UM_SLEEP);
3810 
3811 	if (mdb_walk("arc_buf_hdr_t_full", arc_compression_stats_cb,
3812 	    &data) != 0) {
3813 		mdb_warn("can't walk arc_buf_hdr's");
3814 		rc = DCMD_ERR;
3815 		goto out;
3816 	}
3817 
3818 	if (data.arc_cflags & ARC_CFLAG_VERBOSE) {
3819 		rc = mdb_snprintf(range, sizeof (range),
3820 		    "[n*%llu, (n+1)*%llu)", SPA_MINBLOCKSIZE,
3821 		    SPA_MINBLOCKSIZE);
3822 	} else {
3823 		rc = mdb_snprintf(range, sizeof (range),
3824 		    "[2^(n-1)*%llu, 2^n*%llu)", SPA_MINBLOCKSIZE,
3825 		    SPA_MINBLOCKSIZE);
3826 	}
3827 
3828 	if (rc < 0) {
3829 		/* snprintf failed, abort the dcmd */
3830 		rc = DCMD_ERR;
3831 		goto out;
3832 	} else {
3833 		/* snprintf succeeded above, reset return code */
3834 		rc = DCMD_OK;
3835 	}
3836 
3837 	if (data.arc_cflags & ARC_CFLAG_ANON) {
3838 		if (data.arc_cflags & ARC_CFLAG_BUFS) {
3839 			mdb_printf("Histogram of the number of anon buffers "
3840 			    "that are associated with an arc hdr.\n");
3841 			dump_histogram(data.anon_bufs, data.hist_nbuckets, 0);
3842 			mdb_printf("\n");
3843 		}
3844 		mdb_printf("Histogram of compressed anon buffers.\n"
3845 		    "Each bucket represents buffers of size: %s.\n", range);
3846 		dump_histogram(data.anon_c_hist, data.hist_nbuckets, 0);
3847 		mdb_printf("\n");
3848 
3849 		mdb_printf("Histogram of uncompressed anon buffers.\n"
3850 		    "Each bucket represents buffers of size: %s.\n", range);
3851 		dump_histogram(data.anon_u_hist, data.hist_nbuckets, 0);
3852 		mdb_printf("\n");
3853 	}
3854 
3855 	if (data.arc_cflags & ARC_CFLAG_MRU) {
3856 		if (data.arc_cflags & ARC_CFLAG_BUFS) {
3857 			mdb_printf("Histogram of the number of mru buffers "
3858 			    "that are associated with an arc hdr.\n");
3859 			dump_histogram(data.mru_bufs, data.hist_nbuckets, 0);
3860 			mdb_printf("\n");
3861 		}
3862 		mdb_printf("Histogram of compressed mru buffers.\n"
3863 		    "Each bucket represents buffers of size: %s.\n", range);
3864 		dump_histogram(data.mru_c_hist, data.hist_nbuckets, 0);
3865 		mdb_printf("\n");
3866 
3867 		mdb_printf("Histogram of uncompressed mru buffers.\n"
3868 		    "Each bucket represents buffers of size: %s.\n", range);
3869 		dump_histogram(data.mru_u_hist, data.hist_nbuckets, 0);
3870 		mdb_printf("\n");
3871 	}
3872 
3873 	if (data.arc_cflags & ARC_CFLAG_MFU) {
3874 		if (data.arc_cflags & ARC_CFLAG_BUFS) {
3875 			mdb_printf("Histogram of the number of mfu buffers "
3876 			    "that are associated with an arc hdr.\n");
3877 			dump_histogram(data.mfu_bufs, data.hist_nbuckets, 0);
3878 			mdb_printf("\n");
3879 		}
3880 
3881 		mdb_printf("Histogram of compressed mfu buffers.\n"
3882 		    "Each bucket represents buffers of size: %s.\n", range);
3883 		dump_histogram(data.mfu_c_hist, data.hist_nbuckets, 0);
3884 		mdb_printf("\n");
3885 
3886 		mdb_printf("Histogram of uncompressed mfu buffers.\n"
3887 		    "Each bucket represents buffers of size: %s.\n", range);
3888 		dump_histogram(data.mfu_u_hist, data.hist_nbuckets, 0);
3889 		mdb_printf("\n");
3890 	}
3891 
3892 	if (data.arc_cflags & ARC_CFLAG_BUFS) {
3893 		mdb_printf("Histogram of all buffers that "
3894 		    "are associated with an arc hdr.\n");
3895 		dump_histogram(data.all_bufs, data.hist_nbuckets, 0);
3896 		mdb_printf("\n");
3897 	}
3898 
3899 	mdb_printf("Histogram of all compressed buffers.\n"
3900 	    "Each bucket represents buffers of size: %s.\n", range);
3901 	dump_histogram(data.all_c_hist, data.hist_nbuckets, 0);
3902 	mdb_printf("\n");
3903 
3904 	mdb_printf("Histogram of all uncompressed buffers.\n"
3905 	    "Each bucket represents buffers of size: %s.\n", range);
3906 	dump_histogram(data.all_u_hist, data.hist_nbuckets, 0);
3907 
3908 out:
3909 	mdb_free(data.anon_c_hist, hist_size);
3910 	mdb_free(data.anon_u_hist, hist_size);
3911 	mdb_free(data.anon_bufs, hist_size);
3912 
3913 	mdb_free(data.mru_c_hist, hist_size);
3914 	mdb_free(data.mru_u_hist, hist_size);
3915 	mdb_free(data.mru_bufs, hist_size);
3916 
3917 	mdb_free(data.mfu_c_hist, hist_size);
3918 	mdb_free(data.mfu_u_hist, hist_size);
3919 	mdb_free(data.mfu_bufs, hist_size);
3920 
3921 	mdb_free(data.all_c_hist, hist_size);
3922 	mdb_free(data.all_u_hist, hist_size);
3923 	mdb_free(data.all_bufs, hist_size);
3924 
3925 	return (rc);
3926 }
3927 
3928 /*
3929  * MDB module linkage information:
3930  *
3931  * We declare a list of structures describing our dcmds, and a function
3932  * named _mdb_init to return a pointer to our module information.
3933  */
3934 
3935 static const mdb_dcmd_t dcmds[] = {
3936 	{ "arc", "[-bkmg]", "print ARC variables", arc_print },
3937 	{ "blkptr", ":", "print blkptr_t", blkptr },
3938 	{ "dva", ":", "print dva_t", dva },
3939 	{ "dbuf", ":", "print dmu_buf_impl_t", dbuf },
3940 	{ "dbuf_stats", ":", "dbuf stats", dbuf_stats },
3941 	{ "dbufs",
3942 	    "\t[-O objset_t*] [-n objset_name | \"mos\"] "
3943 	    "[-o object | \"mdn\"] \n"
3944 	    "\t[-l level] [-b blkid | \"bonus\"]",
3945 	    "find dmu_buf_impl_t's that match specified criteria", dbufs },
3946 	{ "abuf_find", "dva_word[0] dva_word[1]",
3947 	    "find arc_buf_hdr_t of a specified DVA",
3948 	    abuf_find },
3949 	{ "spa", "?[-cevmMh]\n"
3950 	    "\t-c display spa config\n"
3951 	    "\t-e display vdev statistics\n"
3952 	    "\t-v display vdev information\n"
3953 	    "\t-m display metaslab statistics\n"
3954 	    "\t-M display metaslab group statistics\n"
3955 	    "\t-h display histogram (requires -m or -M)\n",
3956 	    "spa_t summary", spa_print },
3957 	{ "spa_config", ":", "print spa_t configuration", spa_print_config },
3958 	{ "spa_space", ":[-b]", "print spa_t on-disk space usage", spa_space },
3959 	{ "spa_vdevs", ":[-emMh]\n"
3960 	    "\t-e display vdev statistics\n"
3961 	    "\t-m dispaly metaslab statistics\n"
3962 	    "\t-M display metaslab group statistic\n"
3963 	    "\t-h display histogram (requires -m or -M)\n",
3964 	    "given a spa_t, print vdev summary", spa_vdevs },
3965 	{ "vdev", ":[-remMh]\n"
3966 	    "\t-r display recursively\n"
3967 	    "\t-e display statistics\n"
3968 	    "\t-m display metaslab statistics (top level vdev only)\n"
3969 	    "\t-M display metaslab group statistics (top level vdev only)\n"
3970 	    "\t-h display histogram (requires -m or -M)\n",
3971 	    "vdev_t summary", vdev_print },
3972 	{ "zio", ":[-cpr]\n"
3973 	    "\t-c display children\n"
3974 	    "\t-p display parents\n"
3975 	    "\t-r display recursively",
3976 	    "zio_t summary", zio_print },
3977 	{ "zio_state", "?", "print out all zio_t structures on system or "
3978 	    "for a particular pool", zio_state },
3979 	{ "zfs_blkstats", ":[-v]",
3980 	    "given a spa_t, print block type stats from last scrub",
3981 	    zfs_blkstats },
3982 	{ "zfs_params", "", "print zfs tunable parameters", zfs_params },
3983 	{ "refcount", ":[-r]\n"
3984 	    "\t-r display recently removed references",
3985 	    "print refcount_t holders", refcount },
3986 	{ "zap_leaf", "", "print zap_leaf_phys_t", zap_leaf },
3987 	{ "zfs_aces", ":[-v]", "print all ACEs from a zfs_acl_t",
3988 	    zfs_acl_dump },
3989 	{ "zfs_ace", ":[-v]", "print zfs_ace", zfs_ace_print },
3990 	{ "zfs_ace0", ":[-v]", "print zfs_ace0", zfs_ace0_print },
3991 	{ "sa_attr_table", ":", "print SA attribute table from sa_os_t",
3992 	    sa_attr_table},
3993 	{ "sa_attr", ": attr_id",
3994 	    "print SA attribute address when given sa_handle_t", sa_attr_print},
3995 	{ "zfs_dbgmsg", ":[-va]",
3996 	    "print zfs debug log", dbgmsg},
3997 	{ "rrwlock", ":",
3998 	    "print rrwlock_t, including readers", rrwlock},
3999 	{ "metaslab_weight", "weight",
4000 	    "print metaslab weight", metaslab_weight},
4001 	{ "metaslab_trace", ":",
4002 	    "print metaslab allocation trace records", metaslab_trace},
4003 	{ "arc_compression_stats", ":[-vabrf]\n"
4004 	    "\t-v verbose, display a linearly scaled histogram\n"
4005 	    "\t-a display ARC_anon state statistics individually\n"
4006 	    "\t-r display ARC_mru state statistics individually\n"
4007 	    "\t-f display ARC_mfu state statistics individually\n"
4008 	    "\t-b display histogram of buffer counts\n",
4009 	    "print a histogram of compressed arc buffer sizes",
4010 	    arc_compression_stats},
4011 	{ NULL }
4012 };
4013 
4014 static const mdb_walker_t walkers[] = {
4015 	{ "zms_freelist", "walk ZFS metaslab freelist",
4016 	    freelist_walk_init, freelist_walk_step, NULL },
4017 	{ "txg_list", "given any txg_list_t *, walk all entries in all txgs",
4018 	    txg_list_walk_init, txg_list_walk_step, NULL },
4019 	{ "txg_list0", "given any txg_list_t *, walk all entries in txg 0",
4020 	    txg_list0_walk_init, txg_list_walk_step, NULL },
4021 	{ "txg_list1", "given any txg_list_t *, walk all entries in txg 1",
4022 	    txg_list1_walk_init, txg_list_walk_step, NULL },
4023 	{ "txg_list2", "given any txg_list_t *, walk all entries in txg 2",
4024 	    txg_list2_walk_init, txg_list_walk_step, NULL },
4025 	{ "txg_list3", "given any txg_list_t *, walk all entries in txg 3",
4026 	    txg_list3_walk_init, txg_list_walk_step, NULL },
4027 	{ "zio", "walk all zio structures, optionally for a particular spa_t",
4028 	    zio_walk_init, zio_walk_step, NULL },
4029 	{ "zio_root",
4030 	    "walk all root zio_t structures, optionally for a particular spa_t",
4031 	    zio_walk_init, zio_walk_root_step, NULL },
4032 	{ "spa", "walk all spa_t entries in the namespace",
4033 	    spa_walk_init, spa_walk_step, NULL },
4034 	{ "metaslab", "given a spa_t *, walk all metaslab_t structures",
4035 	    metaslab_walk_init, metaslab_walk_step, NULL },
4036 	{ "multilist", "given a multilist_t *, walk all list_t structures",
4037 	    multilist_walk_init, multilist_walk_step, NULL },
4038 	{ "zfs_acl_node", "given a zfs_acl_t, walk all zfs_acl_nodes",
4039 	    zfs_acl_node_walk_init, zfs_acl_node_walk_step, NULL },
4040 	{ "zfs_acl_node_aces", "given a zfs_acl_node_t, walk all ACEs",
4041 	    zfs_acl_node_aces_walk_init, zfs_aces_walk_step, NULL },
4042 	{ "zfs_acl_node_aces0",
4043 	    "given a zfs_acl_node_t, walk all ACEs as ace_t",
4044 	    zfs_acl_node_aces0_walk_init, zfs_aces_walk_step, NULL },
4045 	{ NULL }
4046 };
4047 
4048 static const mdb_modinfo_t modinfo = {
4049 	MDB_API_VERSION, dcmds, walkers
4050 };
4051 
4052 const mdb_modinfo_t *
4053 _mdb_init(void)
4054 {
4055 	return (&modinfo);
4056 }
4057