xref: /illumos-gate/usr/src/cmd/mdb/common/modules/zfs/zfs.c (revision c160bf3613805cfb4a89a0433ae896d3594f551f)
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  */
26 
27 /* Portions Copyright 2010 Robert Milkowski */
28 
29 #include <mdb/mdb_ctf.h>
30 #include <sys/zfs_context.h>
31 #include <sys/mdb_modapi.h>
32 #include <sys/dbuf.h>
33 #include <sys/dmu_objset.h>
34 #include <sys/dsl_dir.h>
35 #include <sys/dsl_pool.h>
36 #include <sys/metaslab_impl.h>
37 #include <sys/space_map.h>
38 #include <sys/list.h>
39 #include <sys/vdev_impl.h>
40 #include <sys/zap_leaf.h>
41 #include <sys/zap_impl.h>
42 #include <ctype.h>
43 #include <sys/zfs_acl.h>
44 #include <sys/sa_impl.h>
45 #include <sys/multilist.h>
46 
47 #ifdef _KERNEL
48 #define	ZFS_OBJ_NAME	"zfs"
49 extern int64_t mdb_gethrtime(void);
50 #else
51 #define	ZFS_OBJ_NAME	"libzpool.so.1"
52 #endif
53 
54 #define	ZFS_STRUCT	"struct " ZFS_OBJ_NAME "`"
55 
56 #ifndef _KERNEL
57 int aok;
58 #endif
59 
60 enum spa_flags {
61 	SPA_FLAG_CONFIG			= 1 << 0,
62 	SPA_FLAG_VDEVS			= 1 << 1,
63 	SPA_FLAG_ERRORS			= 1 << 2,
64 	SPA_FLAG_METASLAB_GROUPS	= 1 << 3,
65 	SPA_FLAG_METASLABS		= 1 << 4,
66 	SPA_FLAG_HISTOGRAMS		= 1 << 5
67 };
68 
69 /*
70  * If any of these flags are set, call spa_vdevs in spa_print
71  */
72 #define	SPA_FLAG_ALL_VDEV	\
73 	(SPA_FLAG_VDEVS | SPA_FLAG_ERRORS | SPA_FLAG_METASLAB_GROUPS | \
74 	SPA_FLAG_METASLABS)
75 
76 static int
77 getmember(uintptr_t addr, const char *type, mdb_ctf_id_t *idp,
78     const char *member, int len, void *buf)
79 {
80 	mdb_ctf_id_t id;
81 	ulong_t off;
82 	char name[64];
83 
84 	if (idp == NULL) {
85 		if (mdb_ctf_lookup_by_name(type, &id) == -1) {
86 			mdb_warn("couldn't find type %s", type);
87 			return (DCMD_ERR);
88 		}
89 		idp = &id;
90 	} else {
91 		type = name;
92 		mdb_ctf_type_name(*idp, name, sizeof (name));
93 	}
94 
95 	if (mdb_ctf_offsetof(*idp, member, &off) == -1) {
96 		mdb_warn("couldn't find member %s of type %s\n", member, type);
97 		return (DCMD_ERR);
98 	}
99 	if (off % 8 != 0) {
100 		mdb_warn("member %s of type %s is unsupported bitfield",
101 		    member, type);
102 		return (DCMD_ERR);
103 	}
104 	off /= 8;
105 
106 	if (mdb_vread(buf, len, addr + off) == -1) {
107 		mdb_warn("failed to read %s from %s at %p",
108 		    member, type, addr + off);
109 		return (DCMD_ERR);
110 	}
111 	/* mdb_warn("read %s from %s at %p+%llx\n", member, type, addr, off); */
112 
113 	return (0);
114 }
115 
116 #define	GETMEMB(addr, structname, member, dest) \
117 	getmember(addr, ZFS_STRUCT structname, NULL, #member, \
118 	sizeof (dest), &(dest))
119 
120 #define	GETMEMBID(addr, ctfid, member, dest) \
121 	getmember(addr, NULL, ctfid, #member, sizeof (dest), &(dest))
122 
123 static boolean_t
124 strisprint(const char *cp)
125 {
126 	for (; *cp; cp++) {
127 		if (!isprint(*cp))
128 			return (B_FALSE);
129 	}
130 	return (B_TRUE);
131 }
132 
133 #define	NICENUM_BUFLEN 6
134 
135 static int
136 snprintfrac(char *buf, int len,
137     uint64_t numerator, uint64_t denom, int frac_digits)
138 {
139 	int mul = 1;
140 	int whole, frac, i;
141 
142 	for (i = frac_digits; i; i--)
143 		mul *= 10;
144 	whole = numerator / denom;
145 	frac = mul * numerator / denom - mul * whole;
146 	return (mdb_snprintf(buf, len, "%u.%0*u", whole, frac_digits, frac));
147 }
148 
149 static void
150 mdb_nicenum(uint64_t num, char *buf)
151 {
152 	uint64_t n = num;
153 	int index = 0;
154 	char *u;
155 
156 	while (n >= 1024) {
157 		n = (n + (1024 / 2)) / 1024; /* Round up or down */
158 		index++;
159 	}
160 
161 	u = &" \0K\0M\0G\0T\0P\0E\0"[index*2];
162 
163 	if (index == 0) {
164 		(void) mdb_snprintf(buf, NICENUM_BUFLEN, "%llu",
165 		    (u_longlong_t)n);
166 	} else if (n < 10 && (num & (num - 1)) != 0) {
167 		(void) snprintfrac(buf, NICENUM_BUFLEN,
168 		    num, 1ULL << 10 * index, 2);
169 		strcat(buf, u);
170 	} else if (n < 100 && (num & (num - 1)) != 0) {
171 		(void) snprintfrac(buf, NICENUM_BUFLEN,
172 		    num, 1ULL << 10 * index, 1);
173 		strcat(buf, u);
174 	} else {
175 		(void) mdb_snprintf(buf, NICENUM_BUFLEN, "%llu%s",
176 		    (u_longlong_t)n, u);
177 	}
178 }
179 
180 static int verbose;
181 
182 static int
183 freelist_walk_init(mdb_walk_state_t *wsp)
184 {
185 	if (wsp->walk_addr == NULL) {
186 		mdb_warn("must supply starting address\n");
187 		return (WALK_ERR);
188 	}
189 
190 	wsp->walk_data = 0;  /* Index into the freelist */
191 	return (WALK_NEXT);
192 }
193 
194 static int
195 freelist_walk_step(mdb_walk_state_t *wsp)
196 {
197 	uint64_t entry;
198 	uintptr_t number = (uintptr_t)wsp->walk_data;
199 	char *ddata[] = { "ALLOC", "FREE", "CONDENSE", "INVALID",
200 			    "INVALID", "INVALID", "INVALID", "INVALID" };
201 	int mapshift = SPA_MINBLOCKSHIFT;
202 
203 	if (mdb_vread(&entry, sizeof (entry), wsp->walk_addr) == -1) {
204 		mdb_warn("failed to read freelist entry %p", wsp->walk_addr);
205 		return (WALK_DONE);
206 	}
207 	wsp->walk_addr += sizeof (entry);
208 	wsp->walk_data = (void *)(number + 1);
209 
210 	if (SM_DEBUG_DECODE(entry)) {
211 		mdb_printf("DEBUG: %3u  %10s: txg=%llu  pass=%llu\n",
212 		    number,
213 		    ddata[SM_DEBUG_ACTION_DECODE(entry)],
214 		    SM_DEBUG_TXG_DECODE(entry),
215 		    SM_DEBUG_SYNCPASS_DECODE(entry));
216 	} else {
217 		mdb_printf("Entry: %3u  offsets=%08llx-%08llx  type=%c  "
218 		    "size=%06llx", number,
219 		    SM_OFFSET_DECODE(entry) << mapshift,
220 		    (SM_OFFSET_DECODE(entry) + SM_RUN_DECODE(entry)) <<
221 		    mapshift,
222 		    SM_TYPE_DECODE(entry) == SM_ALLOC ? 'A' : 'F',
223 		    SM_RUN_DECODE(entry) << mapshift);
224 		if (verbose)
225 			mdb_printf("      (raw=%012llx)\n", entry);
226 		mdb_printf("\n");
227 	}
228 	return (WALK_NEXT);
229 }
230 
231 static int
232 mdb_dsl_dir_name(uintptr_t addr, char *buf)
233 {
234 	static int gotid;
235 	static mdb_ctf_id_t dd_id;
236 	uintptr_t dd_parent;
237 	char dd_myname[ZFS_MAX_DATASET_NAME_LEN];
238 
239 	if (!gotid) {
240 		if (mdb_ctf_lookup_by_name(ZFS_STRUCT "dsl_dir",
241 		    &dd_id) == -1) {
242 			mdb_warn("couldn't find struct dsl_dir");
243 			return (DCMD_ERR);
244 		}
245 		gotid = TRUE;
246 	}
247 	if (GETMEMBID(addr, &dd_id, dd_parent, dd_parent) ||
248 	    GETMEMBID(addr, &dd_id, dd_myname, dd_myname)) {
249 		return (DCMD_ERR);
250 	}
251 
252 	if (dd_parent) {
253 		if (mdb_dsl_dir_name(dd_parent, buf))
254 			return (DCMD_ERR);
255 		strcat(buf, "/");
256 	}
257 
258 	if (dd_myname[0])
259 		strcat(buf, dd_myname);
260 	else
261 		strcat(buf, "???");
262 
263 	return (0);
264 }
265 
266 static int
267 objset_name(uintptr_t addr, char *buf)
268 {
269 	static int gotid;
270 	static mdb_ctf_id_t os_id, ds_id;
271 	uintptr_t os_dsl_dataset;
272 	char ds_snapname[ZFS_MAX_DATASET_NAME_LEN];
273 	uintptr_t ds_dir;
274 
275 	buf[0] = '\0';
276 
277 	if (!gotid) {
278 		if (mdb_ctf_lookup_by_name(ZFS_STRUCT "objset",
279 		    &os_id) == -1) {
280 			mdb_warn("couldn't find struct objset");
281 			return (DCMD_ERR);
282 		}
283 		if (mdb_ctf_lookup_by_name(ZFS_STRUCT "dsl_dataset",
284 		    &ds_id) == -1) {
285 			mdb_warn("couldn't find struct dsl_dataset");
286 			return (DCMD_ERR);
287 		}
288 
289 		gotid = TRUE;
290 	}
291 
292 	if (GETMEMBID(addr, &os_id, os_dsl_dataset, os_dsl_dataset))
293 		return (DCMD_ERR);
294 
295 	if (os_dsl_dataset == 0) {
296 		strcat(buf, "mos");
297 		return (0);
298 	}
299 
300 	if (GETMEMBID(os_dsl_dataset, &ds_id, ds_snapname, ds_snapname) ||
301 	    GETMEMBID(os_dsl_dataset, &ds_id, ds_dir, ds_dir)) {
302 		return (DCMD_ERR);
303 	}
304 
305 	if (ds_dir && mdb_dsl_dir_name(ds_dir, buf))
306 		return (DCMD_ERR);
307 
308 	if (ds_snapname[0]) {
309 		strcat(buf, "@");
310 		strcat(buf, ds_snapname);
311 	}
312 	return (0);
313 }
314 
315 static int
316 enum_lookup(char *type, int val, const char *prefix, size_t size, char *out)
317 {
318 	const char *cp;
319 	size_t len = strlen(prefix);
320 	mdb_ctf_id_t enum_type;
321 
322 	if (mdb_ctf_lookup_by_name(type, &enum_type) != 0) {
323 		mdb_warn("Could not find enum for %s", type);
324 		return (-1);
325 	}
326 
327 	if ((cp = mdb_ctf_enum_name(enum_type, val)) != NULL) {
328 		if (strncmp(cp, prefix, len) == 0)
329 			cp += len;
330 		(void) strncpy(out, cp, size);
331 	} else {
332 		mdb_snprintf(out, size, "? (%d)", val);
333 	}
334 	return (0);
335 }
336 
337 /* ARGSUSED */
338 static int
339 zfs_params(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
340 {
341 	/*
342 	 * This table can be approximately generated by running:
343 	 * egrep "^[a-z0-9_]+ [a-z0-9_]+( =.*)?;" *.c | cut -d ' ' -f 2
344 	 */
345 	static const char *params[] = {
346 		"arc_reduce_dnlc_percent",
347 		"arc_lotsfree_percent",
348 		"zfs_dirty_data_max",
349 		"zfs_dirty_data_sync",
350 		"zfs_delay_max_ns",
351 		"zfs_delay_min_dirty_percent",
352 		"zfs_delay_scale",
353 		"zfs_vdev_max_active",
354 		"zfs_vdev_sync_read_min_active",
355 		"zfs_vdev_sync_read_max_active",
356 		"zfs_vdev_sync_write_min_active",
357 		"zfs_vdev_sync_write_max_active",
358 		"zfs_vdev_async_read_min_active",
359 		"zfs_vdev_async_read_max_active",
360 		"zfs_vdev_async_write_min_active",
361 		"zfs_vdev_async_write_max_active",
362 		"zfs_vdev_scrub_min_active",
363 		"zfs_vdev_scrub_max_active",
364 		"zfs_vdev_async_write_active_min_dirty_percent",
365 		"zfs_vdev_async_write_active_max_dirty_percent",
366 		"spa_asize_inflation",
367 		"zfs_arc_max",
368 		"zfs_arc_min",
369 		"arc_shrink_shift",
370 		"zfs_mdcomp_disable",
371 		"zfs_prefetch_disable",
372 		"zfetch_max_streams",
373 		"zfetch_min_sec_reap",
374 		"zfetch_block_cap",
375 		"zfetch_array_rd_sz",
376 		"zfs_default_bs",
377 		"zfs_default_ibs",
378 		"metaslab_aliquot",
379 		"reference_tracking_enable",
380 		"reference_history",
381 		"spa_max_replication_override",
382 		"spa_mode_global",
383 		"zfs_flags",
384 		"zfs_txg_timeout",
385 		"zfs_vdev_cache_max",
386 		"zfs_vdev_cache_size",
387 		"zfs_vdev_cache_bshift",
388 		"vdev_mirror_shift",
389 		"zfs_scrub_limit",
390 		"zfs_no_scrub_io",
391 		"zfs_no_scrub_prefetch",
392 		"zfs_vdev_aggregation_limit",
393 		"fzap_default_block_shift",
394 		"zfs_immediate_write_sz",
395 		"zfs_read_chunk_size",
396 		"zfs_nocacheflush",
397 		"zil_replay_disable",
398 		"metaslab_gang_bang",
399 		"metaslab_df_alloc_threshold",
400 		"metaslab_df_free_pct",
401 		"zio_injection_enabled",
402 		"zvol_immediate_write_sz",
403 	};
404 
405 	for (int i = 0; i < sizeof (params) / sizeof (params[0]); i++) {
406 		int sz;
407 		uint64_t val64;
408 		uint32_t *val32p = (uint32_t *)&val64;
409 
410 		sz = mdb_readvar(&val64, params[i]);
411 		if (sz == 4) {
412 			mdb_printf("%s = 0x%x\n", params[i], *val32p);
413 		} else if (sz == 8) {
414 			mdb_printf("%s = 0x%llx\n", params[i], val64);
415 		} else {
416 			mdb_warn("variable %s not found", params[i]);
417 		}
418 	}
419 
420 	return (DCMD_OK);
421 }
422 
423 /* ARGSUSED */
424 static int
425 blkptr(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
426 {
427 	char type[80], checksum[80], compress[80];
428 	blkptr_t blk, *bp = &blk;
429 	char buf[BP_SPRINTF_LEN];
430 
431 	if (mdb_vread(&blk, sizeof (blkptr_t), addr) == -1) {
432 		mdb_warn("failed to read blkptr_t");
433 		return (DCMD_ERR);
434 	}
435 
436 	if (enum_lookup("enum dmu_object_type", BP_GET_TYPE(bp), "DMU_OT_",
437 	    sizeof (type), type) == -1 ||
438 	    enum_lookup("enum zio_checksum", BP_GET_CHECKSUM(bp),
439 	    "ZIO_CHECKSUM_", sizeof (checksum), checksum) == -1 ||
440 	    enum_lookup("enum zio_compress", BP_GET_COMPRESS(bp),
441 	    "ZIO_COMPRESS_", sizeof (compress), compress) == -1) {
442 		mdb_warn("Could not find blkptr enumerated types");
443 		return (DCMD_ERR);
444 	}
445 
446 	SNPRINTF_BLKPTR(mdb_snprintf, '\n', buf, sizeof (buf), bp, type,
447 	    checksum, compress);
448 
449 	mdb_printf("%s\n", buf);
450 
451 	return (DCMD_OK);
452 }
453 
454 typedef struct mdb_dmu_buf_impl {
455 	struct {
456 		uint64_t db_object;
457 		uintptr_t db_data;
458 	} db;
459 	uintptr_t db_objset;
460 	uint64_t db_level;
461 	uint64_t db_blkid;
462 	struct {
463 		uint64_t rc_count;
464 	} db_holds;
465 } mdb_dmu_buf_impl_t;
466 
467 /* ARGSUSED */
468 static int
469 dbuf(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
470 {
471 	mdb_dmu_buf_impl_t db;
472 	char objectname[32];
473 	char blkidname[32];
474 	char path[ZFS_MAX_DATASET_NAME_LEN];
475 	int ptr_width = (int)(sizeof (void *)) * 2;
476 
477 	if (DCMD_HDRSPEC(flags))
478 		mdb_printf("%*s %8s %3s %9s %5s %s\n",
479 		    ptr_width, "addr", "object", "lvl", "blkid", "holds", "os");
480 
481 	if (mdb_ctf_vread(&db, ZFS_STRUCT "dmu_buf_impl", "mdb_dmu_buf_impl_t",
482 	    addr, 0) == -1)
483 		return (DCMD_ERR);
484 
485 	if (db.db.db_object == DMU_META_DNODE_OBJECT)
486 		(void) strcpy(objectname, "mdn");
487 	else
488 		(void) mdb_snprintf(objectname, sizeof (objectname), "%llx",
489 		    (u_longlong_t)db.db.db_object);
490 
491 	if (db.db_blkid == DMU_BONUS_BLKID)
492 		(void) strcpy(blkidname, "bonus");
493 	else
494 		(void) mdb_snprintf(blkidname, sizeof (blkidname), "%llx",
495 		    (u_longlong_t)db.db_blkid);
496 
497 	if (objset_name(db.db_objset, path)) {
498 		return (DCMD_ERR);
499 	}
500 
501 	mdb_printf("%*p %8s %3u %9s %5llu %s\n", ptr_width, addr,
502 	    objectname, (int)db.db_level, blkidname,
503 	    db.db_holds.rc_count, path);
504 
505 	return (DCMD_OK);
506 }
507 
508 /* ARGSUSED */
509 static int
510 dbuf_stats(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
511 {
512 #define	HISTOSZ 32
513 	uintptr_t dbp;
514 	dmu_buf_impl_t db;
515 	dbuf_hash_table_t ht;
516 	uint64_t bucket, ndbufs;
517 	uint64_t histo[HISTOSZ];
518 	uint64_t histo2[HISTOSZ];
519 	int i, maxidx;
520 
521 	if (mdb_readvar(&ht, "dbuf_hash_table") == -1) {
522 		mdb_warn("failed to read 'dbuf_hash_table'");
523 		return (DCMD_ERR);
524 	}
525 
526 	for (i = 0; i < HISTOSZ; i++) {
527 		histo[i] = 0;
528 		histo2[i] = 0;
529 	}
530 
531 	ndbufs = 0;
532 	for (bucket = 0; bucket < ht.hash_table_mask+1; bucket++) {
533 		int len;
534 
535 		if (mdb_vread(&dbp, sizeof (void *),
536 		    (uintptr_t)(ht.hash_table+bucket)) == -1) {
537 			mdb_warn("failed to read hash bucket %u at %p",
538 			    bucket, ht.hash_table+bucket);
539 			return (DCMD_ERR);
540 		}
541 
542 		len = 0;
543 		while (dbp != 0) {
544 			if (mdb_vread(&db, sizeof (dmu_buf_impl_t),
545 			    dbp) == -1) {
546 				mdb_warn("failed to read dbuf at %p", dbp);
547 				return (DCMD_ERR);
548 			}
549 			dbp = (uintptr_t)db.db_hash_next;
550 			for (i = MIN(len, HISTOSZ - 1); i >= 0; i--)
551 				histo2[i]++;
552 			len++;
553 			ndbufs++;
554 		}
555 
556 		if (len >= HISTOSZ)
557 			len = HISTOSZ-1;
558 		histo[len]++;
559 	}
560 
561 	mdb_printf("hash table has %llu buckets, %llu dbufs "
562 	    "(avg %llu buckets/dbuf)\n",
563 	    ht.hash_table_mask+1, ndbufs,
564 	    (ht.hash_table_mask+1)/ndbufs);
565 
566 	mdb_printf("\n");
567 	maxidx = 0;
568 	for (i = 0; i < HISTOSZ; i++)
569 		if (histo[i] > 0)
570 			maxidx = i;
571 	mdb_printf("hash chain length	number of buckets\n");
572 	for (i = 0; i <= maxidx; i++)
573 		mdb_printf("%u			%llu\n", i, histo[i]);
574 
575 	mdb_printf("\n");
576 	maxidx = 0;
577 	for (i = 0; i < HISTOSZ; i++)
578 		if (histo2[i] > 0)
579 			maxidx = i;
580 	mdb_printf("hash chain depth	number of dbufs\n");
581 	for (i = 0; i <= maxidx; i++)
582 		mdb_printf("%u or more		%llu	%llu%%\n",
583 		    i, histo2[i], histo2[i]*100/ndbufs);
584 
585 
586 	return (DCMD_OK);
587 }
588 
589 #define	CHAIN_END 0xffff
590 /*
591  * ::zap_leaf [-v]
592  *
593  * Print a zap_leaf_phys_t, assumed to be 16k
594  */
595 /* ARGSUSED */
596 static int
597 zap_leaf(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
598 {
599 	char buf[16*1024];
600 	int verbose = B_FALSE;
601 	int four = B_FALSE;
602 	dmu_buf_t l_dbuf;
603 	zap_leaf_t l;
604 	zap_leaf_phys_t *zlp = (void *)buf;
605 	int i;
606 
607 	if (mdb_getopts(argc, argv,
608 	    'v', MDB_OPT_SETBITS, TRUE, &verbose,
609 	    '4', MDB_OPT_SETBITS, TRUE, &four,
610 	    NULL) != argc)
611 		return (DCMD_USAGE);
612 
613 	l_dbuf.db_data = zlp;
614 	l.l_dbuf = &l_dbuf;
615 	l.l_bs = 14; /* assume 16k blocks */
616 	if (four)
617 		l.l_bs = 12;
618 
619 	if (!(flags & DCMD_ADDRSPEC)) {
620 		return (DCMD_USAGE);
621 	}
622 
623 	if (mdb_vread(buf, sizeof (buf), addr) == -1) {
624 		mdb_warn("failed to read zap_leaf_phys_t at %p", addr);
625 		return (DCMD_ERR);
626 	}
627 
628 	if (zlp->l_hdr.lh_block_type != ZBT_LEAF ||
629 	    zlp->l_hdr.lh_magic != ZAP_LEAF_MAGIC) {
630 		mdb_warn("This does not appear to be a zap_leaf_phys_t");
631 		return (DCMD_ERR);
632 	}
633 
634 	mdb_printf("zap_leaf_phys_t at %p:\n", addr);
635 	mdb_printf("    lh_prefix_len = %u\n", zlp->l_hdr.lh_prefix_len);
636 	mdb_printf("    lh_prefix = %llx\n", zlp->l_hdr.lh_prefix);
637 	mdb_printf("    lh_nentries = %u\n", zlp->l_hdr.lh_nentries);
638 	mdb_printf("    lh_nfree = %u\n", zlp->l_hdr.lh_nfree,
639 	    zlp->l_hdr.lh_nfree * 100 / (ZAP_LEAF_NUMCHUNKS(&l)));
640 	mdb_printf("    lh_freelist = %u\n", zlp->l_hdr.lh_freelist);
641 	mdb_printf("    lh_flags = %x (%s)\n", zlp->l_hdr.lh_flags,
642 	    zlp->l_hdr.lh_flags & ZLF_ENTRIES_CDSORTED ?
643 	    "ENTRIES_CDSORTED" : "");
644 
645 	if (verbose) {
646 		mdb_printf(" hash table:\n");
647 		for (i = 0; i < ZAP_LEAF_HASH_NUMENTRIES(&l); i++) {
648 			if (zlp->l_hash[i] != CHAIN_END)
649 				mdb_printf("    %u: %u\n", i, zlp->l_hash[i]);
650 		}
651 	}
652 
653 	mdb_printf(" chunks:\n");
654 	for (i = 0; i < ZAP_LEAF_NUMCHUNKS(&l); i++) {
655 		/* LINTED: alignment */
656 		zap_leaf_chunk_t *zlc = &ZAP_LEAF_CHUNK(&l, i);
657 		switch (zlc->l_entry.le_type) {
658 		case ZAP_CHUNK_FREE:
659 			if (verbose) {
660 				mdb_printf("    %u: free; lf_next = %u\n",
661 				    i, zlc->l_free.lf_next);
662 			}
663 			break;
664 		case ZAP_CHUNK_ENTRY:
665 			mdb_printf("    %u: entry\n", i);
666 			if (verbose) {
667 				mdb_printf("        le_next = %u\n",
668 				    zlc->l_entry.le_next);
669 			}
670 			mdb_printf("        le_name_chunk = %u\n",
671 			    zlc->l_entry.le_name_chunk);
672 			mdb_printf("        le_name_numints = %u\n",
673 			    zlc->l_entry.le_name_numints);
674 			mdb_printf("        le_value_chunk = %u\n",
675 			    zlc->l_entry.le_value_chunk);
676 			mdb_printf("        le_value_intlen = %u\n",
677 			    zlc->l_entry.le_value_intlen);
678 			mdb_printf("        le_value_numints = %u\n",
679 			    zlc->l_entry.le_value_numints);
680 			mdb_printf("        le_cd = %u\n",
681 			    zlc->l_entry.le_cd);
682 			mdb_printf("        le_hash = %llx\n",
683 			    zlc->l_entry.le_hash);
684 			break;
685 		case ZAP_CHUNK_ARRAY:
686 			mdb_printf("    %u: array", i);
687 			if (strisprint((char *)zlc->l_array.la_array))
688 				mdb_printf(" \"%s\"", zlc->l_array.la_array);
689 			mdb_printf("\n");
690 			if (verbose) {
691 				int j;
692 				mdb_printf("        ");
693 				for (j = 0; j < ZAP_LEAF_ARRAY_BYTES; j++) {
694 					mdb_printf("%02x ",
695 					    zlc->l_array.la_array[j]);
696 				}
697 				mdb_printf("\n");
698 			}
699 			if (zlc->l_array.la_next != CHAIN_END) {
700 				mdb_printf("        lf_next = %u\n",
701 				    zlc->l_array.la_next);
702 			}
703 			break;
704 		default:
705 			mdb_printf("    %u: undefined type %u\n",
706 			    zlc->l_entry.le_type);
707 		}
708 	}
709 
710 	return (DCMD_OK);
711 }
712 
713 typedef struct dbufs_data {
714 	mdb_ctf_id_t id;
715 	uint64_t objset;
716 	uint64_t object;
717 	uint64_t level;
718 	uint64_t blkid;
719 	char *osname;
720 } dbufs_data_t;
721 
722 #define	DBUFS_UNSET	(0xbaddcafedeadbeefULL)
723 
724 /* ARGSUSED */
725 static int
726 dbufs_cb(uintptr_t addr, const void *unknown, void *arg)
727 {
728 	dbufs_data_t *data = arg;
729 	uintptr_t objset;
730 	dmu_buf_t db;
731 	uint8_t level;
732 	uint64_t blkid;
733 	char osname[ZFS_MAX_DATASET_NAME_LEN];
734 
735 	if (GETMEMBID(addr, &data->id, db_objset, objset) ||
736 	    GETMEMBID(addr, &data->id, db, db) ||
737 	    GETMEMBID(addr, &data->id, db_level, level) ||
738 	    GETMEMBID(addr, &data->id, db_blkid, blkid)) {
739 		return (WALK_ERR);
740 	}
741 
742 	if ((data->objset == DBUFS_UNSET || data->objset == objset) &&
743 	    (data->osname == NULL || (objset_name(objset, osname) == 0 &&
744 	    strcmp(data->osname, osname) == 0)) &&
745 	    (data->object == DBUFS_UNSET || data->object == db.db_object) &&
746 	    (data->level == DBUFS_UNSET || data->level == level) &&
747 	    (data->blkid == DBUFS_UNSET || data->blkid == blkid)) {
748 		mdb_printf("%#lr\n", addr);
749 	}
750 	return (WALK_NEXT);
751 }
752 
753 /* ARGSUSED */
754 static int
755 dbufs(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
756 {
757 	dbufs_data_t data;
758 	char *object = NULL;
759 	char *blkid = NULL;
760 
761 	data.objset = data.object = data.level = data.blkid = DBUFS_UNSET;
762 	data.osname = NULL;
763 
764 	if (mdb_getopts(argc, argv,
765 	    'O', MDB_OPT_UINT64, &data.objset,
766 	    'n', MDB_OPT_STR, &data.osname,
767 	    'o', MDB_OPT_STR, &object,
768 	    'l', MDB_OPT_UINT64, &data.level,
769 	    'b', MDB_OPT_STR, &blkid) != argc) {
770 		return (DCMD_USAGE);
771 	}
772 
773 	if (object) {
774 		if (strcmp(object, "mdn") == 0) {
775 			data.object = DMU_META_DNODE_OBJECT;
776 		} else {
777 			data.object = mdb_strtoull(object);
778 		}
779 	}
780 
781 	if (blkid) {
782 		if (strcmp(blkid, "bonus") == 0) {
783 			data.blkid = DMU_BONUS_BLKID;
784 		} else {
785 			data.blkid = mdb_strtoull(blkid);
786 		}
787 	}
788 
789 	if (mdb_ctf_lookup_by_name(ZFS_STRUCT "dmu_buf_impl", &data.id) == -1) {
790 		mdb_warn("couldn't find struct dmu_buf_impl_t");
791 		return (DCMD_ERR);
792 	}
793 
794 	if (mdb_walk("dmu_buf_impl_t", dbufs_cb, &data) != 0) {
795 		mdb_warn("can't walk dbufs");
796 		return (DCMD_ERR);
797 	}
798 
799 	return (DCMD_OK);
800 }
801 
802 typedef struct abuf_find_data {
803 	dva_t dva;
804 	mdb_ctf_id_t id;
805 } abuf_find_data_t;
806 
807 /* ARGSUSED */
808 static int
809 abuf_find_cb(uintptr_t addr, const void *unknown, void *arg)
810 {
811 	abuf_find_data_t *data = arg;
812 	dva_t dva;
813 
814 	if (GETMEMBID(addr, &data->id, b_dva, dva)) {
815 		return (WALK_ERR);
816 	}
817 
818 	if (dva.dva_word[0] == data->dva.dva_word[0] &&
819 	    dva.dva_word[1] == data->dva.dva_word[1]) {
820 		mdb_printf("%#lr\n", addr);
821 	}
822 	return (WALK_NEXT);
823 }
824 
825 /* ARGSUSED */
826 static int
827 abuf_find(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
828 {
829 	abuf_find_data_t data;
830 	GElf_Sym sym;
831 	int i;
832 	const char *syms[] = {
833 		"ARC_mru",
834 		"ARC_mru_ghost",
835 		"ARC_mfu",
836 		"ARC_mfu_ghost",
837 	};
838 
839 	if (argc != 2)
840 		return (DCMD_USAGE);
841 
842 	for (i = 0; i < 2; i ++) {
843 		switch (argv[i].a_type) {
844 		case MDB_TYPE_STRING:
845 			data.dva.dva_word[i] = mdb_strtoull(argv[i].a_un.a_str);
846 			break;
847 		case MDB_TYPE_IMMEDIATE:
848 			data.dva.dva_word[i] = argv[i].a_un.a_val;
849 			break;
850 		default:
851 			return (DCMD_USAGE);
852 		}
853 	}
854 
855 	if (mdb_ctf_lookup_by_name(ZFS_STRUCT "arc_buf_hdr", &data.id) == -1) {
856 		mdb_warn("couldn't find struct arc_buf_hdr");
857 		return (DCMD_ERR);
858 	}
859 
860 	for (i = 0; i < sizeof (syms) / sizeof (syms[0]); i++) {
861 		if (mdb_lookup_by_obj(ZFS_OBJ_NAME, syms[i], &sym)) {
862 			mdb_warn("can't find symbol %s", syms[i]);
863 			return (DCMD_ERR);
864 		}
865 
866 		if (mdb_pwalk("list", abuf_find_cb, &data, sym.st_value) != 0) {
867 			mdb_warn("can't walk %s", syms[i]);
868 			return (DCMD_ERR);
869 		}
870 	}
871 
872 	return (DCMD_OK);
873 }
874 
875 
876 typedef struct dbgmsg_arg {
877 	boolean_t da_verbose;
878 	boolean_t da_address;
879 } dbgmsg_arg_t;
880 
881 /* ARGSUSED */
882 static int
883 dbgmsg_cb(uintptr_t addr, const void *unknown, void *arg)
884 {
885 	static mdb_ctf_id_t id;
886 	static boolean_t gotid;
887 	static ulong_t off;
888 
889 	dbgmsg_arg_t *da = arg;
890 	time_t timestamp;
891 	char buf[1024];
892 
893 	if (!gotid) {
894 		if (mdb_ctf_lookup_by_name(ZFS_STRUCT "zfs_dbgmsg", &id) ==
895 		    -1) {
896 			mdb_warn("couldn't find struct zfs_dbgmsg");
897 			return (WALK_ERR);
898 		}
899 		gotid = TRUE;
900 		if (mdb_ctf_offsetof(id, "zdm_msg", &off) == -1) {
901 			mdb_warn("couldn't find zdm_msg");
902 			return (WALK_ERR);
903 		}
904 		off /= 8;
905 	}
906 
907 
908 	if (GETMEMBID(addr, &id, zdm_timestamp, timestamp)) {
909 		return (WALK_ERR);
910 	}
911 
912 	if (mdb_readstr(buf, sizeof (buf), addr + off) == -1) {
913 		mdb_warn("failed to read zdm_msg at %p\n", addr + off);
914 		return (DCMD_ERR);
915 	}
916 
917 	if (da->da_address)
918 		mdb_printf("%p ", addr);
919 	if (da->da_verbose)
920 		mdb_printf("%Y ", timestamp);
921 
922 	mdb_printf("%s\n", buf);
923 
924 	if (da->da_verbose)
925 		(void) mdb_call_dcmd("whatis", addr, DCMD_ADDRSPEC, 0, NULL);
926 
927 	return (WALK_NEXT);
928 }
929 
930 /* ARGSUSED */
931 static int
932 dbgmsg(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
933 {
934 	GElf_Sym sym;
935 	dbgmsg_arg_t da = { 0 };
936 
937 	if (mdb_getopts(argc, argv,
938 	    'v', MDB_OPT_SETBITS, B_TRUE, &da.da_verbose,
939 	    'a', MDB_OPT_SETBITS, B_TRUE, &da.da_address,
940 	    NULL) != argc)
941 		return (DCMD_USAGE);
942 
943 	if (mdb_lookup_by_obj(ZFS_OBJ_NAME, "zfs_dbgmsgs", &sym)) {
944 		mdb_warn("can't find zfs_dbgmsgs");
945 		return (DCMD_ERR);
946 	}
947 
948 	if (mdb_pwalk("list", dbgmsg_cb, &da, sym.st_value) != 0) {
949 		mdb_warn("can't walk zfs_dbgmsgs");
950 		return (DCMD_ERR);
951 	}
952 
953 	return (DCMD_OK);
954 }
955 
956 /*ARGSUSED*/
957 static int
958 arc_print(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
959 {
960 	kstat_named_t *stats;
961 	GElf_Sym sym;
962 	int nstats, i;
963 	uint_t opt_a = FALSE;
964 	uint_t opt_b = FALSE;
965 	uint_t shift = 0;
966 	const char *suffix;
967 
968 	static const char *bytestats[] = {
969 		"p", "c", "c_min", "c_max", "size", "duplicate_buffers_size",
970 		"arc_meta_used", "arc_meta_limit", "arc_meta_max",
971 		"arc_meta_min", "hdr_size", "data_size", "metadata_size",
972 		"other_size", "anon_size", "anon_evictable_data",
973 		"anon_evictable_metadata", "mru_size", "mru_evictable_data",
974 		"mru_evictable_metadata", "mru_ghost_size",
975 		"mru_ghost_evictable_data", "mru_ghost_evictable_metadata",
976 		"mfu_size", "mfu_evictable_data", "mfu_evictable_metadata",
977 		"mfu_ghost_size", "mfu_ghost_evictable_data",
978 		"mfu_ghost_evictable_metadata", "evict_l2_cached",
979 		"evict_l2_eligible", "evict_l2_ineligible", "l2_read_bytes",
980 		"l2_write_bytes", "l2_size", "l2_asize", "l2_hdr_size",
981 		"compressed_size", "uncompressed_size", "overhead_size",
982 		NULL
983 	};
984 
985 	static const char *extras[] = {
986 		"arc_no_grow", "arc_tempreserve",
987 		NULL
988 	};
989 
990 	if (mdb_lookup_by_obj(ZFS_OBJ_NAME, "arc_stats", &sym) == -1) {
991 		mdb_warn("failed to find 'arc_stats'");
992 		return (DCMD_ERR);
993 	}
994 
995 	stats = mdb_zalloc(sym.st_size, UM_SLEEP | UM_GC);
996 
997 	if (mdb_vread(stats, sym.st_size, sym.st_value) == -1) {
998 		mdb_warn("couldn't read 'arc_stats' at %p", sym.st_value);
999 		return (DCMD_ERR);
1000 	}
1001 
1002 	nstats = sym.st_size / sizeof (kstat_named_t);
1003 
1004 	/* NB: -a / opt_a are ignored for backwards compatability */
1005 	if (mdb_getopts(argc, argv,
1006 	    'a', MDB_OPT_SETBITS, TRUE, &opt_a,
1007 	    'b', MDB_OPT_SETBITS, TRUE, &opt_b,
1008 	    'k', MDB_OPT_SETBITS, 10, &shift,
1009 	    'm', MDB_OPT_SETBITS, 20, &shift,
1010 	    'g', MDB_OPT_SETBITS, 30, &shift,
1011 	    NULL) != argc)
1012 		return (DCMD_USAGE);
1013 
1014 	if (!opt_b && !shift)
1015 		shift = 20;
1016 
1017 	switch (shift) {
1018 	case 0:
1019 		suffix = "B";
1020 		break;
1021 	case 10:
1022 		suffix = "KB";
1023 		break;
1024 	case 20:
1025 		suffix = "MB";
1026 		break;
1027 	case 30:
1028 		suffix = "GB";
1029 		break;
1030 	default:
1031 		suffix = "XX";
1032 	}
1033 
1034 	for (i = 0; i < nstats; i++) {
1035 		int j;
1036 		boolean_t bytes = B_FALSE;
1037 
1038 		for (j = 0; bytestats[j]; j++) {
1039 			if (strcmp(stats[i].name, bytestats[j]) == 0) {
1040 				bytes = B_TRUE;
1041 				break;
1042 			}
1043 		}
1044 
1045 		if (bytes) {
1046 			mdb_printf("%-25s = %9llu %s\n", stats[i].name,
1047 			    stats[i].value.ui64 >> shift, suffix);
1048 		} else {
1049 			mdb_printf("%-25s = %9llu\n", stats[i].name,
1050 			    stats[i].value.ui64);
1051 		}
1052 	}
1053 
1054 	for (i = 0; extras[i]; i++) {
1055 		uint64_t buf;
1056 
1057 		if (mdb_lookup_by_obj(ZFS_OBJ_NAME, extras[i], &sym) == -1) {
1058 			mdb_warn("failed to find '%s'", extras[i]);
1059 			return (DCMD_ERR);
1060 		}
1061 
1062 		if (sym.st_size != sizeof (uint64_t) &&
1063 		    sym.st_size != sizeof (uint32_t)) {
1064 			mdb_warn("expected scalar for variable '%s'\n",
1065 			    extras[i]);
1066 			return (DCMD_ERR);
1067 		}
1068 
1069 		if (mdb_vread(&buf, sym.st_size, sym.st_value) == -1) {
1070 			mdb_warn("couldn't read '%s'", extras[i]);
1071 			return (DCMD_ERR);
1072 		}
1073 
1074 		mdb_printf("%-25s = ", extras[i]);
1075 
1076 		/* NB: all the 64-bit extras happen to be byte counts */
1077 		if (sym.st_size == sizeof (uint64_t))
1078 			mdb_printf("%9llu %s\n", buf >> shift, suffix);
1079 
1080 		if (sym.st_size == sizeof (uint32_t))
1081 			mdb_printf("%9d\n", *((uint32_t *)&buf));
1082 	}
1083 	return (DCMD_OK);
1084 }
1085 
1086 typedef struct mdb_spa_print {
1087 	pool_state_t spa_state;
1088 	char spa_name[ZFS_MAX_DATASET_NAME_LEN];
1089 	uintptr_t spa_normal_class;
1090 } mdb_spa_print_t;
1091 
1092 
1093 const char histo_stars[] = "****************************************";
1094 const int histo_width = sizeof (histo_stars) - 1;
1095 
1096 static void
1097 dump_histogram(const uint64_t *histo, int size, int offset)
1098 {
1099 	int i;
1100 	int minidx = size - 1;
1101 	int maxidx = 0;
1102 	uint64_t max = 0;
1103 
1104 	for (i = 0; i < size; i++) {
1105 		if (histo[i] > max)
1106 			max = histo[i];
1107 		if (histo[i] > 0 && i > maxidx)
1108 			maxidx = i;
1109 		if (histo[i] > 0 && i < minidx)
1110 			minidx = i;
1111 	}
1112 
1113 	if (max < histo_width)
1114 		max = histo_width;
1115 
1116 	for (i = minidx; i <= maxidx; i++) {
1117 		mdb_printf("%3u: %6llu %s\n",
1118 		    i + offset, (u_longlong_t)histo[i],
1119 		    &histo_stars[(max - histo[i]) * histo_width / max]);
1120 	}
1121 }
1122 
1123 typedef struct mdb_metaslab_class {
1124 	uint64_t mc_histogram[RANGE_TREE_HISTOGRAM_SIZE];
1125 } mdb_metaslab_class_t;
1126 
1127 /*
1128  * spa_class_histogram(uintptr_t class_addr)
1129  *
1130  * Prints free space histogram for a device class
1131  *
1132  * Returns DCMD_OK, or DCMD_ERR.
1133  */
1134 static int
1135 spa_class_histogram(uintptr_t class_addr)
1136 {
1137 	mdb_metaslab_class_t mc;
1138 	if (mdb_ctf_vread(&mc, "metaslab_class_t",
1139 	    "mdb_metaslab_class_t", class_addr, 0) == -1)
1140 		return (DCMD_ERR);
1141 
1142 	mdb_inc_indent(4);
1143 	dump_histogram(mc.mc_histogram, RANGE_TREE_HISTOGRAM_SIZE, 0);
1144 	mdb_dec_indent(4);
1145 	return (DCMD_OK);
1146 }
1147 
1148 /*
1149  * ::spa
1150  *
1151  *	-c	Print configuration information as well
1152  *	-v	Print vdev state
1153  *	-e	Print vdev error stats
1154  *	-m	Print vdev metaslab info
1155  *	-M	print vdev metaslab group info
1156  *	-h	Print histogram info (must be combined with -m or -M)
1157  *
1158  * Print a summarized spa_t.  When given no arguments, prints out a table of all
1159  * active pools on the system.
1160  */
1161 /* ARGSUSED */
1162 static int
1163 spa_print(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
1164 {
1165 	const char *statetab[] = { "ACTIVE", "EXPORTED", "DESTROYED",
1166 		"SPARE", "L2CACHE", "UNINIT", "UNAVAIL", "POTENTIAL" };
1167 	const char *state;
1168 	int spa_flags = 0;
1169 
1170 	if (mdb_getopts(argc, argv,
1171 	    'c', MDB_OPT_SETBITS, SPA_FLAG_CONFIG, &spa_flags,
1172 	    'v', MDB_OPT_SETBITS, SPA_FLAG_VDEVS, &spa_flags,
1173 	    'e', MDB_OPT_SETBITS, SPA_FLAG_ERRORS, &spa_flags,
1174 	    'M', MDB_OPT_SETBITS, SPA_FLAG_METASLAB_GROUPS, &spa_flags,
1175 	    'm', MDB_OPT_SETBITS, SPA_FLAG_METASLABS, &spa_flags,
1176 	    'h', MDB_OPT_SETBITS, SPA_FLAG_HISTOGRAMS, &spa_flags,
1177 	    NULL) != argc)
1178 		return (DCMD_USAGE);
1179 
1180 	if (!(flags & DCMD_ADDRSPEC)) {
1181 		if (mdb_walk_dcmd("spa", "spa", argc, argv) == -1) {
1182 			mdb_warn("can't walk spa");
1183 			return (DCMD_ERR);
1184 		}
1185 
1186 		return (DCMD_OK);
1187 	}
1188 
1189 	if (flags & DCMD_PIPE_OUT) {
1190 		mdb_printf("%#lr\n", addr);
1191 		return (DCMD_OK);
1192 	}
1193 
1194 	if (DCMD_HDRSPEC(flags))
1195 		mdb_printf("%<u>%-?s %9s %-*s%</u>\n", "ADDR", "STATE",
1196 		    sizeof (uintptr_t) == 4 ? 60 : 52, "NAME");
1197 
1198 	mdb_spa_print_t spa;
1199 	if (mdb_ctf_vread(&spa, "spa_t", "mdb_spa_print_t", addr, 0) == -1)
1200 		return (DCMD_ERR);
1201 
1202 	if (spa.spa_state < 0 || spa.spa_state > POOL_STATE_UNAVAIL)
1203 		state = "UNKNOWN";
1204 	else
1205 		state = statetab[spa.spa_state];
1206 
1207 	mdb_printf("%0?p %9s %s\n", addr, state, spa.spa_name);
1208 	if (spa_flags & SPA_FLAG_HISTOGRAMS)
1209 		spa_class_histogram(spa.spa_normal_class);
1210 
1211 	if (spa_flags & SPA_FLAG_CONFIG) {
1212 		mdb_printf("\n");
1213 		mdb_inc_indent(4);
1214 		if (mdb_call_dcmd("spa_config", addr, flags, 0,
1215 		    NULL) != DCMD_OK)
1216 			return (DCMD_ERR);
1217 		mdb_dec_indent(4);
1218 	}
1219 
1220 	if (spa_flags & SPA_FLAG_ALL_VDEV) {
1221 		mdb_arg_t v;
1222 		char opts[100] = "-";
1223 		int args =
1224 		    (spa_flags | SPA_FLAG_VDEVS) == SPA_FLAG_VDEVS ? 0 : 1;
1225 
1226 		if (spa_flags & SPA_FLAG_ERRORS)
1227 			strcat(opts, "e");
1228 		if (spa_flags & SPA_FLAG_METASLABS)
1229 			strcat(opts, "m");
1230 		if (spa_flags & SPA_FLAG_METASLAB_GROUPS)
1231 			strcat(opts, "M");
1232 		if (spa_flags & SPA_FLAG_HISTOGRAMS)
1233 			strcat(opts, "h");
1234 
1235 		v.a_type = MDB_TYPE_STRING;
1236 		v.a_un.a_str = opts;
1237 
1238 		mdb_printf("\n");
1239 		mdb_inc_indent(4);
1240 		if (mdb_call_dcmd("spa_vdevs", addr, flags, args,
1241 		    &v) != DCMD_OK)
1242 			return (DCMD_ERR);
1243 		mdb_dec_indent(4);
1244 	}
1245 
1246 	return (DCMD_OK);
1247 }
1248 
1249 typedef struct mdb_spa_config_spa {
1250 	uintptr_t spa_config;
1251 } mdb_spa_config_spa_t;
1252 
1253 /*
1254  * ::spa_config
1255  *
1256  * Given a spa_t, print the configuration information stored in spa_config.
1257  * Since it's just an nvlist, format it as an indented list of name=value pairs.
1258  * We simply read the value of spa_config and pass off to ::nvlist.
1259  */
1260 /* ARGSUSED */
1261 static int
1262 spa_print_config(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
1263 {
1264 	mdb_spa_config_spa_t spa;
1265 
1266 	if (argc != 0 || !(flags & DCMD_ADDRSPEC))
1267 		return (DCMD_USAGE);
1268 
1269 	if (mdb_ctf_vread(&spa, ZFS_STRUCT "spa", "mdb_spa_config_spa_t",
1270 	    addr, 0) == -1)
1271 		return (DCMD_ERR);
1272 
1273 	if (spa.spa_config == 0) {
1274 		mdb_printf("(none)\n");
1275 		return (DCMD_OK);
1276 	}
1277 
1278 	return (mdb_call_dcmd("nvlist", spa.spa_config, flags,
1279 	    0, NULL));
1280 }
1281 
1282 
1283 
1284 typedef struct mdb_range_tree {
1285 	uint64_t rt_space;
1286 } mdb_range_tree_t;
1287 
1288 typedef struct mdb_metaslab_group {
1289 	uint64_t mg_fragmentation;
1290 	uint64_t mg_histogram[RANGE_TREE_HISTOGRAM_SIZE];
1291 	uintptr_t mg_vd;
1292 } mdb_metaslab_group_t;
1293 
1294 typedef struct mdb_metaslab {
1295 	uint64_t ms_id;
1296 	uint64_t ms_start;
1297 	uint64_t ms_size;
1298 	int64_t ms_deferspace;
1299 	uint64_t ms_fragmentation;
1300 	uint64_t ms_weight;
1301 	uintptr_t ms_alloctree[TXG_SIZE];
1302 	uintptr_t ms_freeingtree;
1303 	uintptr_t ms_freedtree;
1304 	uintptr_t ms_tree;
1305 	uintptr_t ms_sm;
1306 } mdb_metaslab_t;
1307 
1308 typedef struct mdb_space_map_phys_t {
1309 	uint64_t smp_alloc;
1310 	uint64_t smp_histogram[SPACE_MAP_HISTOGRAM_SIZE];
1311 } mdb_space_map_phys_t;
1312 
1313 typedef struct mdb_space_map {
1314 	uint64_t sm_size;
1315 	uint8_t sm_shift;
1316 	uint64_t sm_alloc;
1317 	uintptr_t sm_phys;
1318 } mdb_space_map_t;
1319 
1320 typedef struct mdb_vdev {
1321 	uintptr_t vdev_path;
1322 	uintptr_t vdev_ms;
1323 	uintptr_t vdev_ops;
1324 	uint64_t vdev_ms_count;
1325 	uint64_t vdev_id;
1326 	vdev_stat_t vdev_stat;
1327 } mdb_vdev_t;
1328 
1329 typedef struct mdb_vdev_ops {
1330 	char vdev_op_type[16];
1331 } mdb_vdev_ops_t;
1332 
1333 static int
1334 metaslab_stats(uintptr_t addr, int spa_flags)
1335 {
1336 	mdb_vdev_t vdev;
1337 	uintptr_t *vdev_ms;
1338 
1339 	if (mdb_ctf_vread(&vdev, "vdev_t", "mdb_vdev_t",
1340 	    (uintptr_t)addr, 0) == -1) {
1341 		mdb_warn("failed to read vdev at %p\n", addr);
1342 		return (DCMD_ERR);
1343 	}
1344 
1345 	mdb_inc_indent(4);
1346 	mdb_printf("%<u>%-?s %6s %20s %10s %9s%</u>\n", "ADDR", "ID",
1347 	    "OFFSET", "FREE", "FRAGMENTATION");
1348 
1349 	vdev_ms = mdb_alloc(vdev.vdev_ms_count * sizeof (void *),
1350 	    UM_SLEEP | UM_GC);
1351 	if (mdb_vread(vdev_ms, vdev.vdev_ms_count * sizeof (void *),
1352 	    (uintptr_t)vdev.vdev_ms) == -1) {
1353 		mdb_warn("failed to read vdev_ms at %p\n", vdev.vdev_ms);
1354 		return (DCMD_ERR);
1355 	}
1356 
1357 	for (int m = 0; m < vdev.vdev_ms_count; m++) {
1358 		mdb_metaslab_t ms;
1359 		mdb_space_map_t sm = { 0 };
1360 		char free[NICENUM_BUFLEN];
1361 
1362 		if (mdb_ctf_vread(&ms, "metaslab_t", "mdb_metaslab_t",
1363 		    (uintptr_t)vdev_ms[m], 0) == -1)
1364 			return (DCMD_ERR);
1365 
1366 		if (ms.ms_sm != NULL &&
1367 		    mdb_ctf_vread(&sm, "space_map_t", "mdb_space_map_t",
1368 		    ms.ms_sm, 0) == -1)
1369 			return (DCMD_ERR);
1370 
1371 		mdb_nicenum(ms.ms_size - sm.sm_alloc, free);
1372 
1373 		mdb_printf("%0?p %6llu %20llx %10s ", vdev_ms[m], ms.ms_id,
1374 		    ms.ms_start, free);
1375 		if (ms.ms_fragmentation == ZFS_FRAG_INVALID)
1376 			mdb_printf("%9s\n", "-");
1377 		else
1378 			mdb_printf("%9llu%%\n", ms.ms_fragmentation);
1379 
1380 		if ((spa_flags & SPA_FLAG_HISTOGRAMS) && ms.ms_sm != NULL) {
1381 			mdb_space_map_phys_t smp;
1382 
1383 			if (sm.sm_phys == NULL)
1384 				continue;
1385 
1386 			(void) mdb_ctf_vread(&smp, "space_map_phys_t",
1387 			    "mdb_space_map_phys_t", sm.sm_phys, 0);
1388 
1389 			dump_histogram(smp.smp_histogram,
1390 			    SPACE_MAP_HISTOGRAM_SIZE, sm.sm_shift);
1391 		}
1392 	}
1393 	mdb_dec_indent(4);
1394 	return (DCMD_OK);
1395 }
1396 
1397 static int
1398 metaslab_group_stats(uintptr_t addr, int spa_flags)
1399 {
1400 	mdb_metaslab_group_t mg;
1401 	if (mdb_ctf_vread(&mg, "metaslab_group_t", "mdb_metaslab_group_t",
1402 	    (uintptr_t)addr, 0) == -1) {
1403 		mdb_warn("failed to read vdev_mg at %p\n", addr);
1404 		return (DCMD_ERR);
1405 	}
1406 
1407 	mdb_inc_indent(4);
1408 	mdb_printf("%<u>%-?s %15s%</u>\n", "ADDR", "FRAGMENTATION");
1409 	if (mg.mg_fragmentation == ZFS_FRAG_INVALID)
1410 		mdb_printf("%0?p %15s\n", addr, "-");
1411 	else
1412 		mdb_printf("%0?p %15llu%%\n", addr, mg.mg_fragmentation);
1413 
1414 	if (spa_flags & SPA_FLAG_HISTOGRAMS)
1415 		dump_histogram(mg.mg_histogram, RANGE_TREE_HISTOGRAM_SIZE, 0);
1416 	mdb_dec_indent(4);
1417 	return (DCMD_OK);
1418 }
1419 
1420 /*
1421  * ::vdev
1422  *
1423  * Print out a summarized vdev_t, in the following form:
1424  *
1425  * ADDR             STATE	AUX            DESC
1426  * fffffffbcde23df0 HEALTHY	-              /dev/dsk/c0t0d0
1427  *
1428  * If '-r' is specified, recursively visit all children.
1429  *
1430  * With '-e', the statistics associated with the vdev are printed as well.
1431  */
1432 static int
1433 do_print_vdev(uintptr_t addr, int flags, int depth, boolean_t recursive,
1434     int spa_flags)
1435 {
1436 	vdev_t vdev;
1437 	char desc[MAXNAMELEN];
1438 	int c, children;
1439 	uintptr_t *child;
1440 	const char *state, *aux;
1441 
1442 	if (mdb_vread(&vdev, sizeof (vdev), (uintptr_t)addr) == -1) {
1443 		mdb_warn("failed to read vdev_t at %p\n", (uintptr_t)addr);
1444 		return (DCMD_ERR);
1445 	}
1446 
1447 	if (flags & DCMD_PIPE_OUT) {
1448 		mdb_printf("%#lr\n", addr);
1449 	} else {
1450 		if (vdev.vdev_path != NULL) {
1451 			if (mdb_readstr(desc, sizeof (desc),
1452 			    (uintptr_t)vdev.vdev_path) == -1) {
1453 				mdb_warn("failed to read vdev_path at %p\n",
1454 				    vdev.vdev_path);
1455 				return (DCMD_ERR);
1456 			}
1457 		} else if (vdev.vdev_ops != NULL) {
1458 			vdev_ops_t ops;
1459 			if (mdb_vread(&ops, sizeof (ops),
1460 			    (uintptr_t)vdev.vdev_ops) == -1) {
1461 				mdb_warn("failed to read vdev_ops at %p\n",
1462 				    vdev.vdev_ops);
1463 				return (DCMD_ERR);
1464 			}
1465 			(void) strcpy(desc, ops.vdev_op_type);
1466 		} else {
1467 			(void) strcpy(desc, "<unknown>");
1468 		}
1469 
1470 		if (depth == 0 && DCMD_HDRSPEC(flags))
1471 			mdb_printf("%<u>%-?s %-9s %-12s %-*s%</u>\n",
1472 			    "ADDR", "STATE", "AUX",
1473 			    sizeof (uintptr_t) == 4 ? 43 : 35,
1474 			    "DESCRIPTION");
1475 
1476 		mdb_printf("%0?p ", addr);
1477 
1478 		switch (vdev.vdev_state) {
1479 		case VDEV_STATE_CLOSED:
1480 			state = "CLOSED";
1481 			break;
1482 		case VDEV_STATE_OFFLINE:
1483 			state = "OFFLINE";
1484 			break;
1485 		case VDEV_STATE_CANT_OPEN:
1486 			state = "CANT_OPEN";
1487 			break;
1488 		case VDEV_STATE_DEGRADED:
1489 			state = "DEGRADED";
1490 			break;
1491 		case VDEV_STATE_HEALTHY:
1492 			state = "HEALTHY";
1493 			break;
1494 		case VDEV_STATE_REMOVED:
1495 			state = "REMOVED";
1496 			break;
1497 		case VDEV_STATE_FAULTED:
1498 			state = "FAULTED";
1499 			break;
1500 		default:
1501 			state = "UNKNOWN";
1502 			break;
1503 		}
1504 
1505 		switch (vdev.vdev_stat.vs_aux) {
1506 		case VDEV_AUX_NONE:
1507 			aux = "-";
1508 			break;
1509 		case VDEV_AUX_OPEN_FAILED:
1510 			aux = "OPEN_FAILED";
1511 			break;
1512 		case VDEV_AUX_CORRUPT_DATA:
1513 			aux = "CORRUPT_DATA";
1514 			break;
1515 		case VDEV_AUX_NO_REPLICAS:
1516 			aux = "NO_REPLICAS";
1517 			break;
1518 		case VDEV_AUX_BAD_GUID_SUM:
1519 			aux = "BAD_GUID_SUM";
1520 			break;
1521 		case VDEV_AUX_TOO_SMALL:
1522 			aux = "TOO_SMALL";
1523 			break;
1524 		case VDEV_AUX_BAD_LABEL:
1525 			aux = "BAD_LABEL";
1526 			break;
1527 		case VDEV_AUX_VERSION_NEWER:
1528 			aux = "VERS_NEWER";
1529 			break;
1530 		case VDEV_AUX_VERSION_OLDER:
1531 			aux = "VERS_OLDER";
1532 			break;
1533 		case VDEV_AUX_UNSUP_FEAT:
1534 			aux = "UNSUP_FEAT";
1535 			break;
1536 		case VDEV_AUX_SPARED:
1537 			aux = "SPARED";
1538 			break;
1539 		case VDEV_AUX_ERR_EXCEEDED:
1540 			aux = "ERR_EXCEEDED";
1541 			break;
1542 		case VDEV_AUX_IO_FAILURE:
1543 			aux = "IO_FAILURE";
1544 			break;
1545 		case VDEV_AUX_BAD_LOG:
1546 			aux = "BAD_LOG";
1547 			break;
1548 		case VDEV_AUX_EXTERNAL:
1549 			aux = "EXTERNAL";
1550 			break;
1551 		case VDEV_AUX_SPLIT_POOL:
1552 			aux = "SPLIT_POOL";
1553 			break;
1554 		default:
1555 			aux = "UNKNOWN";
1556 			break;
1557 		}
1558 
1559 		mdb_printf("%-9s %-12s %*s%s\n", state, aux, depth, "", desc);
1560 
1561 		if (spa_flags & SPA_FLAG_ERRORS) {
1562 			vdev_stat_t *vs = &vdev.vdev_stat;
1563 			int i;
1564 
1565 			mdb_inc_indent(4);
1566 			mdb_printf("\n");
1567 			mdb_printf("%<u>       %12s %12s %12s %12s "
1568 			    "%12s%</u>\n", "READ", "WRITE", "FREE", "CLAIM",
1569 			    "IOCTL");
1570 			mdb_printf("OPS     ");
1571 			for (i = 1; i < ZIO_TYPES; i++)
1572 				mdb_printf("%11#llx%s", vs->vs_ops[i],
1573 				    i == ZIO_TYPES - 1 ? "" : "  ");
1574 			mdb_printf("\n");
1575 			mdb_printf("BYTES   ");
1576 			for (i = 1; i < ZIO_TYPES; i++)
1577 				mdb_printf("%11#llx%s", vs->vs_bytes[i],
1578 				    i == ZIO_TYPES - 1 ? "" : "  ");
1579 
1580 
1581 			mdb_printf("\n");
1582 			mdb_printf("EREAD    %10#llx\n", vs->vs_read_errors);
1583 			mdb_printf("EWRITE   %10#llx\n", vs->vs_write_errors);
1584 			mdb_printf("ECKSUM   %10#llx\n",
1585 			    vs->vs_checksum_errors);
1586 			mdb_dec_indent(4);
1587 			mdb_printf("\n");
1588 		}
1589 
1590 		if (spa_flags & SPA_FLAG_METASLAB_GROUPS &&
1591 		    vdev.vdev_mg != NULL) {
1592 			metaslab_group_stats((uintptr_t)vdev.vdev_mg,
1593 			    spa_flags);
1594 		}
1595 		if (spa_flags & SPA_FLAG_METASLABS && vdev.vdev_ms != NULL) {
1596 			metaslab_stats((uintptr_t)addr, spa_flags);
1597 		}
1598 	}
1599 
1600 	children = vdev.vdev_children;
1601 
1602 	if (children == 0 || !recursive)
1603 		return (DCMD_OK);
1604 
1605 	child = mdb_alloc(children * sizeof (void *), UM_SLEEP | UM_GC);
1606 	if (mdb_vread(child, children * sizeof (void *),
1607 	    (uintptr_t)vdev.vdev_child) == -1) {
1608 		mdb_warn("failed to read vdev children at %p", vdev.vdev_child);
1609 		return (DCMD_ERR);
1610 	}
1611 
1612 	for (c = 0; c < children; c++) {
1613 		if (do_print_vdev(child[c], flags, depth + 2, recursive,
1614 		    spa_flags)) {
1615 			return (DCMD_ERR);
1616 		}
1617 	}
1618 
1619 	return (DCMD_OK);
1620 }
1621 
1622 static int
1623 vdev_print(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
1624 {
1625 	uint64_t depth = 0;
1626 	boolean_t recursive = B_FALSE;
1627 	int spa_flags = 0;
1628 
1629 	if (mdb_getopts(argc, argv,
1630 	    'e', MDB_OPT_SETBITS, SPA_FLAG_ERRORS, &spa_flags,
1631 	    'm', MDB_OPT_SETBITS, SPA_FLAG_METASLABS, &spa_flags,
1632 	    'M', MDB_OPT_SETBITS, SPA_FLAG_METASLAB_GROUPS, &spa_flags,
1633 	    'h', MDB_OPT_SETBITS, SPA_FLAG_HISTOGRAMS, &spa_flags,
1634 	    'r', MDB_OPT_SETBITS, TRUE, &recursive,
1635 	    'd', MDB_OPT_UINT64, &depth, NULL) != argc)
1636 		return (DCMD_USAGE);
1637 
1638 	if (!(flags & DCMD_ADDRSPEC)) {
1639 		mdb_warn("no vdev_t address given\n");
1640 		return (DCMD_ERR);
1641 	}
1642 
1643 	return (do_print_vdev(addr, flags, (int)depth, recursive, spa_flags));
1644 }
1645 
1646 typedef struct mdb_metaslab_alloc_trace {
1647 	uintptr_t mat_mg;
1648 	uintptr_t mat_msp;
1649 	uint64_t mat_size;
1650 	uint64_t mat_weight;
1651 	uint64_t mat_offset;
1652 	uint32_t mat_dva_id;
1653 } mdb_metaslab_alloc_trace_t;
1654 
1655 static void
1656 metaslab_print_weight(uint64_t weight)
1657 {
1658 	char buf[100];
1659 
1660 	if (WEIGHT_IS_SPACEBASED(weight)) {
1661 		mdb_nicenum(
1662 		    weight & ~(METASLAB_ACTIVE_MASK | METASLAB_WEIGHT_TYPE),
1663 		    buf);
1664 	} else {
1665 		char size[NICENUM_BUFLEN];
1666 		mdb_nicenum(1ULL << WEIGHT_GET_INDEX(weight), size);
1667 		(void) mdb_snprintf(buf, sizeof (buf), "%llu x %s",
1668 		    WEIGHT_GET_COUNT(weight), size);
1669 	}
1670 	mdb_printf("%11s ", buf);
1671 }
1672 
1673 /* ARGSUSED */
1674 static int
1675 metaslab_weight(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
1676 {
1677 	uint64_t weight = 0;
1678 	char active;
1679 
1680 	if (argc == 0 && (flags & DCMD_ADDRSPEC)) {
1681 		if (mdb_vread(&weight, sizeof (uint64_t), addr) == -1) {
1682 			mdb_warn("failed to read weight at %p\n", addr);
1683 			return (DCMD_ERR);
1684 		}
1685 	} else if (argc == 1 && !(flags & DCMD_ADDRSPEC)) {
1686 		weight = (argv[0].a_type == MDB_TYPE_IMMEDIATE) ?
1687 		    argv[0].a_un.a_val : mdb_strtoull(argv[0].a_un.a_str);
1688 	} else {
1689 		return (DCMD_USAGE);
1690 	}
1691 
1692 	if (DCMD_HDRSPEC(flags)) {
1693 		mdb_printf("%<u>%-6s %9s %9s%</u>\n",
1694 		    "ACTIVE", "ALGORITHM", "WEIGHT");
1695 	}
1696 
1697 	if (weight & METASLAB_WEIGHT_PRIMARY)
1698 		active = 'P';
1699 	else if (weight & METASLAB_WEIGHT_SECONDARY)
1700 		active = 'S';
1701 	else
1702 		active = '-';
1703 	mdb_printf("%6c %8s ", active,
1704 	    WEIGHT_IS_SPACEBASED(weight) ? "SPACE" : "SEGMENT");
1705 	metaslab_print_weight(weight);
1706 	mdb_printf("\n");
1707 
1708 	return (DCMD_OK);
1709 }
1710 
1711 /* ARGSUSED */
1712 static int
1713 metaslab_trace(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
1714 {
1715 	mdb_metaslab_alloc_trace_t mat;
1716 	mdb_metaslab_group_t mg = { 0 };
1717 	char result_type[100];
1718 
1719 	if (mdb_ctf_vread(&mat, "metaslab_alloc_trace_t",
1720 	    "mdb_metaslab_alloc_trace_t", addr, 0) == -1) {
1721 		return (DCMD_ERR);
1722 	}
1723 
1724 	if (!(flags & DCMD_PIPE_OUT) && DCMD_HDRSPEC(flags)) {
1725 		mdb_printf("%<u>%6s %6s %8s %11s %18s %18s%</u>\n",
1726 		    "MSID", "DVA", "ASIZE", "WEIGHT", "RESULT", "VDEV");
1727 	}
1728 
1729 	if (mat.mat_msp != NULL) {
1730 		mdb_metaslab_t ms;
1731 
1732 		if (mdb_ctf_vread(&ms, "metaslab_t", "mdb_metaslab_t",
1733 		    mat.mat_msp, 0) == -1) {
1734 			return (DCMD_ERR);
1735 		}
1736 		mdb_printf("%6llu ", ms.ms_id);
1737 	} else {
1738 		mdb_printf("%6s ", "-");
1739 	}
1740 
1741 	mdb_printf("%6d %8llx ", mat.mat_dva_id, mat.mat_size);
1742 
1743 	metaslab_print_weight(mat.mat_weight);
1744 
1745 	if ((int64_t)mat.mat_offset < 0) {
1746 		if (enum_lookup("enum trace_alloc_type", mat.mat_offset,
1747 		    "TRACE_", sizeof (result_type), result_type) == -1) {
1748 			mdb_warn("Could not find enum for trace_alloc_type");
1749 			return (DCMD_ERR);
1750 		}
1751 		mdb_printf("%18s ", result_type);
1752 	} else {
1753 		mdb_printf("%<b>%18llx%</b> ", mat.mat_offset);
1754 	}
1755 
1756 	if (mat.mat_mg != NULL &&
1757 	    mdb_ctf_vread(&mg, "metaslab_group_t", "mdb_metaslab_group_t",
1758 	    mat.mat_mg, 0) == -1) {
1759 		return (DCMD_ERR);
1760 	}
1761 
1762 	if (mg.mg_vd != NULL) {
1763 		mdb_vdev_t vdev;
1764 		char desc[MAXNAMELEN];
1765 
1766 		if (mdb_ctf_vread(&vdev, "vdev_t", "mdb_vdev_t",
1767 		    mg.mg_vd, 0) == -1) {
1768 			return (DCMD_ERR);
1769 		}
1770 
1771 		if (vdev.vdev_path != NULL) {
1772 			char path[MAXNAMELEN];
1773 
1774 			if (mdb_readstr(path, sizeof (path),
1775 			    vdev.vdev_path) == -1) {
1776 				mdb_warn("failed to read vdev_path at %p\n",
1777 				    vdev.vdev_path);
1778 				return (DCMD_ERR);
1779 			}
1780 			char *slash;
1781 			if ((slash = strrchr(path, '/')) != NULL) {
1782 				strcpy(desc, slash + 1);
1783 			} else {
1784 				strcpy(desc, path);
1785 			}
1786 		} else if (vdev.vdev_ops != NULL) {
1787 			mdb_vdev_ops_t ops;
1788 			if (mdb_ctf_vread(&ops, "vdev_ops_t", "mdb_vdev_ops_t",
1789 			    vdev.vdev_ops, 0) == -1) {
1790 				mdb_warn("failed to read vdev_ops at %p\n",
1791 				    vdev.vdev_ops);
1792 				return (DCMD_ERR);
1793 			}
1794 			(void) mdb_snprintf(desc, sizeof (desc),
1795 			    "%s-%llu", ops.vdev_op_type, vdev.vdev_id);
1796 		} else {
1797 			(void) strcpy(desc, "<unknown>");
1798 		}
1799 		mdb_printf("%18s\n", desc);
1800 	}
1801 
1802 	return (DCMD_OK);
1803 }
1804 
1805 typedef struct metaslab_walk_data {
1806 	uint64_t mw_numvdevs;
1807 	uintptr_t *mw_vdevs;
1808 	int mw_curvdev;
1809 	uint64_t mw_nummss;
1810 	uintptr_t *mw_mss;
1811 	int mw_curms;
1812 } metaslab_walk_data_t;
1813 
1814 static int
1815 metaslab_walk_step(mdb_walk_state_t *wsp)
1816 {
1817 	metaslab_walk_data_t *mw = wsp->walk_data;
1818 	metaslab_t ms;
1819 	uintptr_t msp;
1820 
1821 	if (mw->mw_curvdev >= mw->mw_numvdevs)
1822 		return (WALK_DONE);
1823 
1824 	if (mw->mw_mss == NULL) {
1825 		uintptr_t mssp;
1826 		uintptr_t vdevp;
1827 
1828 		ASSERT(mw->mw_curms == 0);
1829 		ASSERT(mw->mw_nummss == 0);
1830 
1831 		vdevp = mw->mw_vdevs[mw->mw_curvdev];
1832 		if (GETMEMB(vdevp, "vdev", vdev_ms, mssp) ||
1833 		    GETMEMB(vdevp, "vdev", vdev_ms_count, mw->mw_nummss)) {
1834 			return (WALK_ERR);
1835 		}
1836 
1837 		mw->mw_mss = mdb_alloc(mw->mw_nummss * sizeof (void*),
1838 		    UM_SLEEP | UM_GC);
1839 		if (mdb_vread(mw->mw_mss, mw->mw_nummss * sizeof (void*),
1840 		    mssp) == -1) {
1841 			mdb_warn("failed to read vdev_ms at %p", mssp);
1842 			return (WALK_ERR);
1843 		}
1844 	}
1845 
1846 	if (mw->mw_curms >= mw->mw_nummss) {
1847 		mw->mw_mss = NULL;
1848 		mw->mw_curms = 0;
1849 		mw->mw_nummss = 0;
1850 		mw->mw_curvdev++;
1851 		return (WALK_NEXT);
1852 	}
1853 
1854 	msp = mw->mw_mss[mw->mw_curms];
1855 	if (mdb_vread(&ms, sizeof (metaslab_t), msp) == -1) {
1856 		mdb_warn("failed to read metaslab_t at %p", msp);
1857 		return (WALK_ERR);
1858 	}
1859 
1860 	mw->mw_curms++;
1861 
1862 	return (wsp->walk_callback(msp, &ms, wsp->walk_cbdata));
1863 }
1864 
1865 static int
1866 metaslab_walk_init(mdb_walk_state_t *wsp)
1867 {
1868 	metaslab_walk_data_t *mw;
1869 	uintptr_t root_vdevp;
1870 	uintptr_t childp;
1871 
1872 	if (wsp->walk_addr == NULL) {
1873 		mdb_warn("must supply address of spa_t\n");
1874 		return (WALK_ERR);
1875 	}
1876 
1877 	mw = mdb_zalloc(sizeof (metaslab_walk_data_t), UM_SLEEP | UM_GC);
1878 
1879 	if (GETMEMB(wsp->walk_addr, "spa", spa_root_vdev, root_vdevp) ||
1880 	    GETMEMB(root_vdevp, "vdev", vdev_children, mw->mw_numvdevs) ||
1881 	    GETMEMB(root_vdevp, "vdev", vdev_child, childp)) {
1882 		return (DCMD_ERR);
1883 	}
1884 
1885 	mw->mw_vdevs = mdb_alloc(mw->mw_numvdevs * sizeof (void *),
1886 	    UM_SLEEP | UM_GC);
1887 	if (mdb_vread(mw->mw_vdevs, mw->mw_numvdevs * sizeof (void *),
1888 	    childp) == -1) {
1889 		mdb_warn("failed to read root vdev children at %p", childp);
1890 		return (DCMD_ERR);
1891 	}
1892 
1893 	wsp->walk_data = mw;
1894 
1895 	return (WALK_NEXT);
1896 }
1897 
1898 typedef struct mdb_spa {
1899 	uintptr_t spa_dsl_pool;
1900 	uintptr_t spa_root_vdev;
1901 } mdb_spa_t;
1902 
1903 typedef struct mdb_dsl_pool {
1904 	uintptr_t dp_root_dir;
1905 } mdb_dsl_pool_t;
1906 
1907 typedef struct mdb_dsl_dir {
1908 	uintptr_t dd_dbuf;
1909 	int64_t dd_space_towrite[TXG_SIZE];
1910 } mdb_dsl_dir_t;
1911 
1912 typedef struct mdb_dsl_dir_phys {
1913 	uint64_t dd_used_bytes;
1914 	uint64_t dd_compressed_bytes;
1915 	uint64_t dd_uncompressed_bytes;
1916 } mdb_dsl_dir_phys_t;
1917 
1918 typedef struct space_data {
1919 	uint64_t ms_alloctree[TXG_SIZE];
1920 	uint64_t ms_freeingtree;
1921 	uint64_t ms_freedtree;
1922 	uint64_t ms_tree;
1923 	int64_t ms_deferspace;
1924 	uint64_t avail;
1925 	uint64_t nowavail;
1926 } space_data_t;
1927 
1928 /* ARGSUSED */
1929 static int
1930 space_cb(uintptr_t addr, const void *unknown, void *arg)
1931 {
1932 	space_data_t *sd = arg;
1933 	mdb_metaslab_t ms;
1934 	mdb_range_tree_t rt;
1935 	mdb_space_map_t sm = { 0 };
1936 	mdb_space_map_phys_t smp = { 0 };
1937 	int i;
1938 
1939 	if (mdb_ctf_vread(&ms, "metaslab_t", "mdb_metaslab_t",
1940 	    addr, 0) == -1)
1941 		return (WALK_ERR);
1942 
1943 	for (i = 0; i < TXG_SIZE; i++) {
1944 		if (mdb_ctf_vread(&rt, "range_tree_t",
1945 		    "mdb_range_tree_t", ms.ms_alloctree[i], 0) == -1)
1946 			return (WALK_ERR);
1947 
1948 		sd->ms_alloctree[i] += rt.rt_space;
1949 
1950 	}
1951 
1952 	if (mdb_ctf_vread(&rt, "range_tree_t",
1953 	    "mdb_range_tree_t", ms.ms_freeingtree, 0) == -1)
1954 		return (WALK_ERR);
1955 	sd->ms_freeingtree += rt.rt_space;
1956 
1957 	if (mdb_ctf_vread(&rt, "range_tree_t",
1958 	    "mdb_range_tree_t", ms.ms_freedtree, 0) == -1)
1959 		return (WALK_ERR);
1960 	sd->ms_freedtree += rt.rt_space;
1961 
1962 	if (mdb_ctf_vread(&rt, "range_tree_t",
1963 	    "mdb_range_tree_t", ms.ms_tree, 0) == -1)
1964 		return (WALK_ERR);
1965 	sd->ms_tree += rt.rt_space;
1966 
1967 	if (ms.ms_sm != NULL &&
1968 	    mdb_ctf_vread(&sm, "space_map_t",
1969 	    "mdb_space_map_t", ms.ms_sm, 0) == -1)
1970 		return (WALK_ERR);
1971 
1972 	if (sm.sm_phys != NULL) {
1973 		(void) mdb_ctf_vread(&smp, "space_map_phys_t",
1974 		    "mdb_space_map_phys_t", sm.sm_phys, 0);
1975 	}
1976 
1977 	sd->ms_deferspace += ms.ms_deferspace;
1978 	sd->avail += sm.sm_size - sm.sm_alloc;
1979 	sd->nowavail += sm.sm_size - smp.smp_alloc;
1980 
1981 	return (WALK_NEXT);
1982 }
1983 
1984 /*
1985  * ::spa_space [-b]
1986  *
1987  * Given a spa_t, print out it's on-disk space usage and in-core
1988  * estimates of future usage.  If -b is given, print space in bytes.
1989  * Otherwise print in megabytes.
1990  */
1991 /* ARGSUSED */
1992 static int
1993 spa_space(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
1994 {
1995 	mdb_spa_t spa;
1996 	mdb_dsl_pool_t dp;
1997 	mdb_dsl_dir_t dd;
1998 	mdb_dmu_buf_impl_t db;
1999 	mdb_dsl_dir_phys_t dsp;
2000 	space_data_t sd;
2001 	int shift = 20;
2002 	char *suffix = "M";
2003 	int bytes = B_FALSE;
2004 
2005 	if (mdb_getopts(argc, argv, 'b', MDB_OPT_SETBITS, TRUE, &bytes, NULL) !=
2006 	    argc)
2007 		return (DCMD_USAGE);
2008 	if (!(flags & DCMD_ADDRSPEC))
2009 		return (DCMD_USAGE);
2010 
2011 	if (bytes) {
2012 		shift = 0;
2013 		suffix = "";
2014 	}
2015 
2016 	if (mdb_ctf_vread(&spa, ZFS_STRUCT "spa", "mdb_spa_t",
2017 	    addr, 0) == -1 ||
2018 	    mdb_ctf_vread(&dp, ZFS_STRUCT "dsl_pool", "mdb_dsl_pool_t",
2019 	    spa.spa_dsl_pool, 0) == -1 ||
2020 	    mdb_ctf_vread(&dd, ZFS_STRUCT "dsl_dir", "mdb_dsl_dir_t",
2021 	    dp.dp_root_dir, 0) == -1 ||
2022 	    mdb_ctf_vread(&db, ZFS_STRUCT "dmu_buf_impl", "mdb_dmu_buf_impl_t",
2023 	    dd.dd_dbuf, 0) == -1 ||
2024 	    mdb_ctf_vread(&dsp, ZFS_STRUCT "dsl_dir_phys",
2025 	    "mdb_dsl_dir_phys_t", db.db.db_data, 0) == -1) {
2026 		return (DCMD_ERR);
2027 	}
2028 
2029 	mdb_printf("dd_space_towrite = %llu%s %llu%s %llu%s %llu%s\n",
2030 	    dd.dd_space_towrite[0] >> shift, suffix,
2031 	    dd.dd_space_towrite[1] >> shift, suffix,
2032 	    dd.dd_space_towrite[2] >> shift, suffix,
2033 	    dd.dd_space_towrite[3] >> shift, suffix);
2034 
2035 	mdb_printf("dd_phys.dd_used_bytes = %llu%s\n",
2036 	    dsp.dd_used_bytes >> shift, suffix);
2037 	mdb_printf("dd_phys.dd_compressed_bytes = %llu%s\n",
2038 	    dsp.dd_compressed_bytes >> shift, suffix);
2039 	mdb_printf("dd_phys.dd_uncompressed_bytes = %llu%s\n",
2040 	    dsp.dd_uncompressed_bytes >> shift, suffix);
2041 
2042 	bzero(&sd, sizeof (sd));
2043 	if (mdb_pwalk("metaslab", space_cb, &sd, addr) != 0) {
2044 		mdb_warn("can't walk metaslabs");
2045 		return (DCMD_ERR);
2046 	}
2047 
2048 	mdb_printf("ms_allocmap = %llu%s %llu%s %llu%s %llu%s\n",
2049 	    sd.ms_alloctree[0] >> shift, suffix,
2050 	    sd.ms_alloctree[1] >> shift, suffix,
2051 	    sd.ms_alloctree[2] >> shift, suffix,
2052 	    sd.ms_alloctree[3] >> shift, suffix);
2053 	mdb_printf("ms_freeingtree = %llu%s\n",
2054 	    sd.ms_freeingtree >> shift, suffix);
2055 	mdb_printf("ms_freedtree = %llu%s\n",
2056 	    sd.ms_freedtree >> shift, suffix);
2057 	mdb_printf("ms_tree = %llu%s\n", sd.ms_tree >> shift, suffix);
2058 	mdb_printf("ms_deferspace = %llu%s\n",
2059 	    sd.ms_deferspace >> shift, suffix);
2060 	mdb_printf("last synced avail = %llu%s\n", sd.avail >> shift, suffix);
2061 	mdb_printf("current syncing avail = %llu%s\n",
2062 	    sd.nowavail >> shift, suffix);
2063 
2064 	return (DCMD_OK);
2065 }
2066 
2067 typedef struct mdb_spa_aux_vdev {
2068 	int sav_count;
2069 	uintptr_t sav_vdevs;
2070 } mdb_spa_aux_vdev_t;
2071 
2072 typedef struct mdb_spa_vdevs {
2073 	uintptr_t spa_root_vdev;
2074 	mdb_spa_aux_vdev_t spa_l2cache;
2075 	mdb_spa_aux_vdev_t spa_spares;
2076 } mdb_spa_vdevs_t;
2077 
2078 static int
2079 spa_print_aux(mdb_spa_aux_vdev_t *sav, uint_t flags, mdb_arg_t *v,
2080     const char *name)
2081 {
2082 	uintptr_t *aux;
2083 	size_t len;
2084 	int ret, i;
2085 
2086 	/*
2087 	 * Iterate over aux vdevs and print those out as well.  This is a
2088 	 * little annoying because we don't have a root vdev to pass to ::vdev.
2089 	 * Instead, we print a single line and then call it for each child
2090 	 * vdev.
2091 	 */
2092 	if (sav->sav_count != 0) {
2093 		v[1].a_type = MDB_TYPE_STRING;
2094 		v[1].a_un.a_str = "-d";
2095 		v[2].a_type = MDB_TYPE_IMMEDIATE;
2096 		v[2].a_un.a_val = 2;
2097 
2098 		len = sav->sav_count * sizeof (uintptr_t);
2099 		aux = mdb_alloc(len, UM_SLEEP);
2100 		if (mdb_vread(aux, len, sav->sav_vdevs) == -1) {
2101 			mdb_free(aux, len);
2102 			mdb_warn("failed to read l2cache vdevs at %p",
2103 			    sav->sav_vdevs);
2104 			return (DCMD_ERR);
2105 		}
2106 
2107 		mdb_printf("%-?s %-9s %-12s %s\n", "-", "-", "-", name);
2108 
2109 		for (i = 0; i < sav->sav_count; i++) {
2110 			ret = mdb_call_dcmd("vdev", aux[i], flags, 3, v);
2111 			if (ret != DCMD_OK) {
2112 				mdb_free(aux, len);
2113 				return (ret);
2114 			}
2115 		}
2116 
2117 		mdb_free(aux, len);
2118 	}
2119 
2120 	return (0);
2121 }
2122 
2123 /*
2124  * ::spa_vdevs
2125  *
2126  *	-e	Include error stats
2127  *	-m	Include metaslab information
2128  *	-M	Include metaslab group information
2129  *	-h	Include histogram information (requires -m or -M)
2130  *
2131  * Print out a summarized list of vdevs for the given spa_t.
2132  * This is accomplished by invoking "::vdev -re" on the root vdev, as well as
2133  * iterating over the cache devices.
2134  */
2135 /* ARGSUSED */
2136 static int
2137 spa_vdevs(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
2138 {
2139 	mdb_arg_t v[3];
2140 	int ret;
2141 	char opts[100] = "-r";
2142 	int spa_flags = 0;
2143 
2144 	if (mdb_getopts(argc, argv,
2145 	    'e', MDB_OPT_SETBITS, SPA_FLAG_ERRORS, &spa_flags,
2146 	    'm', MDB_OPT_SETBITS, SPA_FLAG_METASLABS, &spa_flags,
2147 	    'M', MDB_OPT_SETBITS, SPA_FLAG_METASLAB_GROUPS, &spa_flags,
2148 	    'h', MDB_OPT_SETBITS, SPA_FLAG_HISTOGRAMS, &spa_flags,
2149 	    NULL) != argc)
2150 		return (DCMD_USAGE);
2151 
2152 	if (!(flags & DCMD_ADDRSPEC))
2153 		return (DCMD_USAGE);
2154 
2155 	mdb_spa_vdevs_t spa;
2156 	if (mdb_ctf_vread(&spa, "spa_t", "mdb_spa_vdevs_t", addr, 0) == -1)
2157 		return (DCMD_ERR);
2158 
2159 	/*
2160 	 * Unitialized spa_t structures can have a NULL root vdev.
2161 	 */
2162 	if (spa.spa_root_vdev == NULL) {
2163 		mdb_printf("no associated vdevs\n");
2164 		return (DCMD_OK);
2165 	}
2166 
2167 	if (spa_flags & SPA_FLAG_ERRORS)
2168 		strcat(opts, "e");
2169 	if (spa_flags & SPA_FLAG_METASLABS)
2170 		strcat(opts, "m");
2171 	if (spa_flags & SPA_FLAG_METASLAB_GROUPS)
2172 		strcat(opts, "M");
2173 	if (spa_flags & SPA_FLAG_HISTOGRAMS)
2174 		strcat(opts, "h");
2175 
2176 	v[0].a_type = MDB_TYPE_STRING;
2177 	v[0].a_un.a_str = opts;
2178 
2179 	ret = mdb_call_dcmd("vdev", (uintptr_t)spa.spa_root_vdev,
2180 	    flags, 1, v);
2181 	if (ret != DCMD_OK)
2182 		return (ret);
2183 
2184 	if (spa_print_aux(&spa.spa_l2cache, flags, v, "cache") != 0 ||
2185 	    spa_print_aux(&spa.spa_spares, flags, v, "spares") != 0)
2186 		return (DCMD_ERR);
2187 
2188 	return (DCMD_OK);
2189 }
2190 
2191 /*
2192  * ::zio
2193  *
2194  * Print a summary of zio_t and all its children.  This is intended to display a
2195  * zio tree, and hence we only pick the most important pieces of information for
2196  * the main summary.  More detailed information can always be found by doing a
2197  * '::print zio' on the underlying zio_t.  The columns we display are:
2198  *
2199  *	ADDRESS  TYPE  STAGE  WAITER  TIME_ELAPSED
2200  *
2201  * The 'address' column is indented by one space for each depth level as we
2202  * descend down the tree.
2203  */
2204 
2205 #define	ZIO_MAXINDENT	7
2206 #define	ZIO_MAXWIDTH	(sizeof (uintptr_t) * 2 + ZIO_MAXINDENT)
2207 #define	ZIO_WALK_SELF	0
2208 #define	ZIO_WALK_CHILD	1
2209 #define	ZIO_WALK_PARENT	2
2210 
2211 typedef struct zio_print_args {
2212 	int	zpa_current_depth;
2213 	int	zpa_min_depth;
2214 	int	zpa_max_depth;
2215 	int	zpa_type;
2216 	uint_t	zpa_flags;
2217 } zio_print_args_t;
2218 
2219 typedef struct mdb_zio {
2220 	enum zio_type io_type;
2221 	enum zio_stage io_stage;
2222 	uintptr_t io_waiter;
2223 	uintptr_t io_spa;
2224 	struct {
2225 		struct {
2226 			uintptr_t list_next;
2227 		} list_head;
2228 	} io_parent_list;
2229 	int io_error;
2230 } mdb_zio_t;
2231 
2232 typedef struct mdb_zio_timestamp {
2233 	hrtime_t io_timestamp;
2234 } mdb_zio_timestamp_t;
2235 
2236 static int zio_child_cb(uintptr_t addr, const void *unknown, void *arg);
2237 
2238 static int
2239 zio_print_cb(uintptr_t addr, zio_print_args_t *zpa)
2240 {
2241 	mdb_ctf_id_t type_enum, stage_enum;
2242 	int indent = zpa->zpa_current_depth;
2243 	const char *type, *stage;
2244 	uintptr_t laddr;
2245 	mdb_zio_t zio;
2246 	mdb_zio_timestamp_t zio_timestamp = { 0 };
2247 
2248 	if (mdb_ctf_vread(&zio, ZFS_STRUCT "zio", "mdb_zio_t", addr, 0) == -1)
2249 		return (WALK_ERR);
2250 	(void) mdb_ctf_vread(&zio_timestamp, ZFS_STRUCT "zio",
2251 	    "mdb_zio_timestamp_t", addr, MDB_CTF_VREAD_QUIET);
2252 
2253 	if (indent > ZIO_MAXINDENT)
2254 		indent = ZIO_MAXINDENT;
2255 
2256 	if (mdb_ctf_lookup_by_name("enum zio_type", &type_enum) == -1 ||
2257 	    mdb_ctf_lookup_by_name("enum zio_stage", &stage_enum) == -1) {
2258 		mdb_warn("failed to lookup zio enums");
2259 		return (WALK_ERR);
2260 	}
2261 
2262 	if ((type = mdb_ctf_enum_name(type_enum, zio.io_type)) != NULL)
2263 		type += sizeof ("ZIO_TYPE_") - 1;
2264 	else
2265 		type = "?";
2266 
2267 	if (zio.io_error == 0) {
2268 		stage = mdb_ctf_enum_name(stage_enum, zio.io_stage);
2269 		if (stage != NULL)
2270 			stage += sizeof ("ZIO_STAGE_") - 1;
2271 		else
2272 			stage = "?";
2273 	} else {
2274 		stage = "FAILED";
2275 	}
2276 
2277 	if (zpa->zpa_current_depth >= zpa->zpa_min_depth) {
2278 		if (zpa->zpa_flags & DCMD_PIPE_OUT) {
2279 			mdb_printf("%?p\n", addr);
2280 		} else {
2281 			mdb_printf("%*s%-*p %-5s %-16s ", indent, "",
2282 			    ZIO_MAXWIDTH - indent, addr, type, stage);
2283 			if (zio.io_waiter != 0)
2284 				mdb_printf("%-16lx ", zio.io_waiter);
2285 			else
2286 				mdb_printf("%-16s ", "-");
2287 #ifdef _KERNEL
2288 			if (zio_timestamp.io_timestamp != 0) {
2289 				mdb_printf("%llums", (mdb_gethrtime() -
2290 				    zio_timestamp.io_timestamp) /
2291 				    1000000);
2292 			} else {
2293 				mdb_printf("%-12s ", "-");
2294 			}
2295 #else
2296 			mdb_printf("%-12s ", "-");
2297 #endif
2298 			mdb_printf("\n");
2299 		}
2300 	}
2301 
2302 	if (zpa->zpa_current_depth >= zpa->zpa_max_depth)
2303 		return (WALK_NEXT);
2304 
2305 	if (zpa->zpa_type == ZIO_WALK_PARENT)
2306 		laddr = addr + mdb_ctf_offsetof_by_name(ZFS_STRUCT "zio",
2307 		    "io_parent_list");
2308 	else
2309 		laddr = addr + mdb_ctf_offsetof_by_name(ZFS_STRUCT "zio",
2310 		    "io_child_list");
2311 
2312 	zpa->zpa_current_depth++;
2313 	if (mdb_pwalk("list", zio_child_cb, zpa, laddr) != 0) {
2314 		mdb_warn("failed to walk zio_t children at %p\n", laddr);
2315 		return (WALK_ERR);
2316 	}
2317 	zpa->zpa_current_depth--;
2318 
2319 	return (WALK_NEXT);
2320 }
2321 
2322 /* ARGSUSED */
2323 static int
2324 zio_child_cb(uintptr_t addr, const void *unknown, void *arg)
2325 {
2326 	zio_link_t zl;
2327 	uintptr_t ziop;
2328 	zio_print_args_t *zpa = arg;
2329 
2330 	if (mdb_vread(&zl, sizeof (zl), addr) == -1) {
2331 		mdb_warn("failed to read zio_link_t at %p", addr);
2332 		return (WALK_ERR);
2333 	}
2334 
2335 	if (zpa->zpa_type == ZIO_WALK_PARENT)
2336 		ziop = (uintptr_t)zl.zl_parent;
2337 	else
2338 		ziop = (uintptr_t)zl.zl_child;
2339 
2340 	return (zio_print_cb(ziop, zpa));
2341 }
2342 
2343 /* ARGSUSED */
2344 static int
2345 zio_print(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
2346 {
2347 	zio_print_args_t zpa = { 0 };
2348 
2349 	if (!(flags & DCMD_ADDRSPEC))
2350 		return (DCMD_USAGE);
2351 
2352 	if (mdb_getopts(argc, argv,
2353 	    'r', MDB_OPT_SETBITS, INT_MAX, &zpa.zpa_max_depth,
2354 	    'c', MDB_OPT_SETBITS, ZIO_WALK_CHILD, &zpa.zpa_type,
2355 	    'p', MDB_OPT_SETBITS, ZIO_WALK_PARENT, &zpa.zpa_type,
2356 	    NULL) != argc)
2357 		return (DCMD_USAGE);
2358 
2359 	zpa.zpa_flags = flags;
2360 	if (zpa.zpa_max_depth != 0) {
2361 		if (zpa.zpa_type == ZIO_WALK_SELF)
2362 			zpa.zpa_type = ZIO_WALK_CHILD;
2363 	} else if (zpa.zpa_type != ZIO_WALK_SELF) {
2364 		zpa.zpa_min_depth = 1;
2365 		zpa.zpa_max_depth = 1;
2366 	}
2367 
2368 	if (!(flags & DCMD_PIPE_OUT) && DCMD_HDRSPEC(flags)) {
2369 		mdb_printf("%<u>%-*s %-5s %-16s %-16s %-12s%</u>\n",
2370 		    ZIO_MAXWIDTH, "ADDRESS", "TYPE", "STAGE", "WAITER",
2371 		    "TIME_ELAPSED");
2372 	}
2373 
2374 	if (zio_print_cb(addr, &zpa) != WALK_NEXT)
2375 		return (DCMD_ERR);
2376 
2377 	return (DCMD_OK);
2378 }
2379 
2380 /*
2381  * [addr]::zio_state
2382  *
2383  * Print a summary of all zio_t structures on the system, or for a particular
2384  * pool.  This is equivalent to '::walk zio_root | ::zio'.
2385  */
2386 /*ARGSUSED*/
2387 static int
2388 zio_state(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
2389 {
2390 	/*
2391 	 * MDB will remember the last address of the pipeline, so if we don't
2392 	 * zero this we'll end up trying to walk zio structures for a
2393 	 * non-existent spa_t.
2394 	 */
2395 	if (!(flags & DCMD_ADDRSPEC))
2396 		addr = 0;
2397 
2398 	return (mdb_pwalk_dcmd("zio_root", "zio", argc, argv, addr));
2399 }
2400 
2401 typedef struct mdb_multilist {
2402 	uint64_t ml_num_sublists;
2403 	uintptr_t ml_sublists;
2404 } mdb_multilist_t;
2405 
2406 typedef struct multilist_walk_data {
2407 	uint64_t mwd_idx;
2408 	mdb_multilist_t mwd_ml;
2409 } multilist_walk_data_t;
2410 
2411 /* ARGSUSED */
2412 static int
2413 multilist_print_cb(uintptr_t addr, const void *unknown, void *arg)
2414 {
2415 	mdb_printf("%#lr\n", addr);
2416 	return (WALK_NEXT);
2417 }
2418 
2419 static int
2420 multilist_walk_step(mdb_walk_state_t *wsp)
2421 {
2422 	multilist_walk_data_t *mwd = wsp->walk_data;
2423 
2424 	if (mwd->mwd_idx >= mwd->mwd_ml.ml_num_sublists)
2425 		return (WALK_DONE);
2426 
2427 	wsp->walk_addr = mwd->mwd_ml.ml_sublists +
2428 	    mdb_ctf_sizeof_by_name("multilist_sublist_t") * mwd->mwd_idx +
2429 	    mdb_ctf_offsetof_by_name("multilist_sublist_t", "mls_list");
2430 
2431 	mdb_pwalk("list", multilist_print_cb, (void*)NULL, wsp->walk_addr);
2432 	mwd->mwd_idx++;
2433 
2434 	return (WALK_NEXT);
2435 }
2436 
2437 static int
2438 multilist_walk_init(mdb_walk_state_t *wsp)
2439 {
2440 	multilist_walk_data_t *mwd;
2441 
2442 	if (wsp->walk_addr == NULL) {
2443 		mdb_warn("must supply address of multilist_t\n");
2444 		return (WALK_ERR);
2445 	}
2446 
2447 	mwd = mdb_zalloc(sizeof (multilist_walk_data_t), UM_SLEEP | UM_GC);
2448 	if (mdb_ctf_vread(&mwd->mwd_ml, "multilist_t", "mdb_multilist_t",
2449 	    wsp->walk_addr, 0) == -1) {
2450 		return (WALK_ERR);
2451 	}
2452 
2453 	if (mwd->mwd_ml.ml_num_sublists == 0 ||
2454 	    mwd->mwd_ml.ml_sublists == NULL) {
2455 		mdb_warn("invalid or uninitialized multilist at %#lx\n",
2456 		    wsp->walk_addr);
2457 		return (WALK_ERR);
2458 	}
2459 
2460 	wsp->walk_data = mwd;
2461 	return (WALK_NEXT);
2462 }
2463 
2464 typedef struct txg_list_walk_data {
2465 	uintptr_t lw_head[TXG_SIZE];
2466 	int	lw_txgoff;
2467 	int	lw_maxoff;
2468 	size_t	lw_offset;
2469 	void	*lw_obj;
2470 } txg_list_walk_data_t;
2471 
2472 static int
2473 txg_list_walk_init_common(mdb_walk_state_t *wsp, int txg, int maxoff)
2474 {
2475 	txg_list_walk_data_t *lwd;
2476 	txg_list_t list;
2477 	int i;
2478 
2479 	lwd = mdb_alloc(sizeof (txg_list_walk_data_t), UM_SLEEP | UM_GC);
2480 	if (mdb_vread(&list, sizeof (txg_list_t), wsp->walk_addr) == -1) {
2481 		mdb_warn("failed to read txg_list_t at %#lx", wsp->walk_addr);
2482 		return (WALK_ERR);
2483 	}
2484 
2485 	for (i = 0; i < TXG_SIZE; i++)
2486 		lwd->lw_head[i] = (uintptr_t)list.tl_head[i];
2487 	lwd->lw_offset = list.tl_offset;
2488 	lwd->lw_obj = mdb_alloc(lwd->lw_offset + sizeof (txg_node_t),
2489 	    UM_SLEEP | UM_GC);
2490 	lwd->lw_txgoff = txg;
2491 	lwd->lw_maxoff = maxoff;
2492 
2493 	wsp->walk_addr = lwd->lw_head[lwd->lw_txgoff];
2494 	wsp->walk_data = lwd;
2495 
2496 	return (WALK_NEXT);
2497 }
2498 
2499 static int
2500 txg_list_walk_init(mdb_walk_state_t *wsp)
2501 {
2502 	return (txg_list_walk_init_common(wsp, 0, TXG_SIZE-1));
2503 }
2504 
2505 static int
2506 txg_list0_walk_init(mdb_walk_state_t *wsp)
2507 {
2508 	return (txg_list_walk_init_common(wsp, 0, 0));
2509 }
2510 
2511 static int
2512 txg_list1_walk_init(mdb_walk_state_t *wsp)
2513 {
2514 	return (txg_list_walk_init_common(wsp, 1, 1));
2515 }
2516 
2517 static int
2518 txg_list2_walk_init(mdb_walk_state_t *wsp)
2519 {
2520 	return (txg_list_walk_init_common(wsp, 2, 2));
2521 }
2522 
2523 static int
2524 txg_list3_walk_init(mdb_walk_state_t *wsp)
2525 {
2526 	return (txg_list_walk_init_common(wsp, 3, 3));
2527 }
2528 
2529 static int
2530 txg_list_walk_step(mdb_walk_state_t *wsp)
2531 {
2532 	txg_list_walk_data_t *lwd = wsp->walk_data;
2533 	uintptr_t addr;
2534 	txg_node_t *node;
2535 	int status;
2536 
2537 	while (wsp->walk_addr == NULL && lwd->lw_txgoff < lwd->lw_maxoff) {
2538 		lwd->lw_txgoff++;
2539 		wsp->walk_addr = lwd->lw_head[lwd->lw_txgoff];
2540 	}
2541 
2542 	if (wsp->walk_addr == NULL)
2543 		return (WALK_DONE);
2544 
2545 	addr = wsp->walk_addr - lwd->lw_offset;
2546 
2547 	if (mdb_vread(lwd->lw_obj,
2548 	    lwd->lw_offset + sizeof (txg_node_t), addr) == -1) {
2549 		mdb_warn("failed to read list element at %#lx", addr);
2550 		return (WALK_ERR);
2551 	}
2552 
2553 	status = wsp->walk_callback(addr, lwd->lw_obj, wsp->walk_cbdata);
2554 	node = (txg_node_t *)((uintptr_t)lwd->lw_obj + lwd->lw_offset);
2555 	wsp->walk_addr = (uintptr_t)node->tn_next[lwd->lw_txgoff];
2556 
2557 	return (status);
2558 }
2559 
2560 /*
2561  * ::walk spa
2562  *
2563  * Walk all named spa_t structures in the namespace.  This is nothing more than
2564  * a layered avl walk.
2565  */
2566 static int
2567 spa_walk_init(mdb_walk_state_t *wsp)
2568 {
2569 	GElf_Sym sym;
2570 
2571 	if (wsp->walk_addr != NULL) {
2572 		mdb_warn("spa walk only supports global walks\n");
2573 		return (WALK_ERR);
2574 	}
2575 
2576 	if (mdb_lookup_by_obj(ZFS_OBJ_NAME, "spa_namespace_avl", &sym) == -1) {
2577 		mdb_warn("failed to find symbol 'spa_namespace_avl'");
2578 		return (WALK_ERR);
2579 	}
2580 
2581 	wsp->walk_addr = (uintptr_t)sym.st_value;
2582 
2583 	if (mdb_layered_walk("avl", wsp) == -1) {
2584 		mdb_warn("failed to walk 'avl'\n");
2585 		return (WALK_ERR);
2586 	}
2587 
2588 	return (WALK_NEXT);
2589 }
2590 
2591 static int
2592 spa_walk_step(mdb_walk_state_t *wsp)
2593 {
2594 	return (wsp->walk_callback(wsp->walk_addr, NULL, wsp->walk_cbdata));
2595 }
2596 
2597 /*
2598  * [addr]::walk zio
2599  *
2600  * Walk all active zio_t structures on the system.  This is simply a layered
2601  * walk on top of ::walk zio_cache, with the optional ability to limit the
2602  * structures to a particular pool.
2603  */
2604 static int
2605 zio_walk_init(mdb_walk_state_t *wsp)
2606 {
2607 	wsp->walk_data = (void *)wsp->walk_addr;
2608 
2609 	if (mdb_layered_walk("zio_cache", wsp) == -1) {
2610 		mdb_warn("failed to walk 'zio_cache'\n");
2611 		return (WALK_ERR);
2612 	}
2613 
2614 	return (WALK_NEXT);
2615 }
2616 
2617 static int
2618 zio_walk_step(mdb_walk_state_t *wsp)
2619 {
2620 	mdb_zio_t zio;
2621 	uintptr_t spa = (uintptr_t)wsp->walk_data;
2622 
2623 	if (mdb_ctf_vread(&zio, ZFS_STRUCT "zio", "mdb_zio_t",
2624 	    wsp->walk_addr, 0) == -1)
2625 		return (WALK_ERR);
2626 
2627 	if (spa != 0 && spa != zio.io_spa)
2628 		return (WALK_NEXT);
2629 
2630 	return (wsp->walk_callback(wsp->walk_addr, &zio, wsp->walk_cbdata));
2631 }
2632 
2633 /*
2634  * [addr]::walk zio_root
2635  *
2636  * Walk only root zio_t structures, optionally for a particular spa_t.
2637  */
2638 static int
2639 zio_walk_root_step(mdb_walk_state_t *wsp)
2640 {
2641 	mdb_zio_t zio;
2642 	uintptr_t spa = (uintptr_t)wsp->walk_data;
2643 
2644 	if (mdb_ctf_vread(&zio, ZFS_STRUCT "zio", "mdb_zio_t",
2645 	    wsp->walk_addr, 0) == -1)
2646 		return (WALK_ERR);
2647 
2648 	if (spa != 0 && spa != zio.io_spa)
2649 		return (WALK_NEXT);
2650 
2651 	/* If the parent list is not empty, ignore */
2652 	if (zio.io_parent_list.list_head.list_next !=
2653 	    wsp->walk_addr +
2654 	    mdb_ctf_offsetof_by_name(ZFS_STRUCT "zio", "io_parent_list") +
2655 	    mdb_ctf_offsetof_by_name("struct list", "list_head"))
2656 		return (WALK_NEXT);
2657 
2658 	return (wsp->walk_callback(wsp->walk_addr, &zio, wsp->walk_cbdata));
2659 }
2660 
2661 /*
2662  * ::zfs_blkstats
2663  *
2664  *	-v	print verbose per-level information
2665  *
2666  */
2667 static int
2668 zfs_blkstats(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
2669 {
2670 	boolean_t verbose = B_FALSE;
2671 	zfs_all_blkstats_t stats;
2672 	dmu_object_type_t t;
2673 	zfs_blkstat_t *tzb;
2674 	uint64_t ditto;
2675 	dmu_object_type_info_t dmu_ot[DMU_OT_NUMTYPES + 10];
2676 	/* +10 in case it grew */
2677 
2678 	if (mdb_readvar(&dmu_ot, "dmu_ot") == -1) {
2679 		mdb_warn("failed to read 'dmu_ot'");
2680 		return (DCMD_ERR);
2681 	}
2682 
2683 	if (mdb_getopts(argc, argv,
2684 	    'v', MDB_OPT_SETBITS, TRUE, &verbose,
2685 	    NULL) != argc)
2686 		return (DCMD_USAGE);
2687 
2688 	if (!(flags & DCMD_ADDRSPEC))
2689 		return (DCMD_USAGE);
2690 
2691 	if (GETMEMB(addr, "spa", spa_dsl_pool, addr) ||
2692 	    GETMEMB(addr, "dsl_pool", dp_blkstats, addr) ||
2693 	    mdb_vread(&stats, sizeof (zfs_all_blkstats_t), addr) == -1) {
2694 		mdb_warn("failed to read data at %p;", addr);
2695 		mdb_printf("maybe no stats? run \"zpool scrub\" first.");
2696 		return (DCMD_ERR);
2697 	}
2698 
2699 	tzb = &stats.zab_type[DN_MAX_LEVELS][DMU_OT_TOTAL];
2700 	if (tzb->zb_gangs != 0) {
2701 		mdb_printf("Ganged blocks: %llu\n",
2702 		    (longlong_t)tzb->zb_gangs);
2703 	}
2704 
2705 	ditto = tzb->zb_ditto_2_of_2_samevdev + tzb->zb_ditto_2_of_3_samevdev +
2706 	    tzb->zb_ditto_3_of_3_samevdev;
2707 	if (ditto != 0) {
2708 		mdb_printf("Dittoed blocks on same vdev: %llu\n",
2709 		    (longlong_t)ditto);
2710 	}
2711 
2712 	mdb_printf("\nBlocks\tLSIZE\tPSIZE\tASIZE"
2713 	    "\t  avg\t comp\t%%Total\tType\n");
2714 
2715 	for (t = 0; t <= DMU_OT_TOTAL; t++) {
2716 		char csize[NICENUM_BUFLEN], lsize[NICENUM_BUFLEN];
2717 		char psize[NICENUM_BUFLEN], asize[NICENUM_BUFLEN];
2718 		char avg[NICENUM_BUFLEN];
2719 		char comp[NICENUM_BUFLEN], pct[NICENUM_BUFLEN];
2720 		char typename[64];
2721 		int l;
2722 
2723 
2724 		if (t == DMU_OT_DEFERRED)
2725 			strcpy(typename, "deferred free");
2726 		else if (t == DMU_OT_OTHER)
2727 			strcpy(typename, "other");
2728 		else if (t == DMU_OT_TOTAL)
2729 			strcpy(typename, "Total");
2730 		else if (mdb_readstr(typename, sizeof (typename),
2731 		    (uintptr_t)dmu_ot[t].ot_name) == -1) {
2732 			mdb_warn("failed to read type name");
2733 			return (DCMD_ERR);
2734 		}
2735 
2736 		if (stats.zab_type[DN_MAX_LEVELS][t].zb_asize == 0)
2737 			continue;
2738 
2739 		for (l = -1; l < DN_MAX_LEVELS; l++) {
2740 			int level = (l == -1 ? DN_MAX_LEVELS : l);
2741 			zfs_blkstat_t *zb = &stats.zab_type[level][t];
2742 
2743 			if (zb->zb_asize == 0)
2744 				continue;
2745 
2746 			/*
2747 			 * Don't print each level unless requested.
2748 			 */
2749 			if (!verbose && level != DN_MAX_LEVELS)
2750 				continue;
2751 
2752 			/*
2753 			 * If all the space is level 0, don't print the
2754 			 * level 0 separately.
2755 			 */
2756 			if (level == 0 && zb->zb_asize ==
2757 			    stats.zab_type[DN_MAX_LEVELS][t].zb_asize)
2758 				continue;
2759 
2760 			mdb_nicenum(zb->zb_count, csize);
2761 			mdb_nicenum(zb->zb_lsize, lsize);
2762 			mdb_nicenum(zb->zb_psize, psize);
2763 			mdb_nicenum(zb->zb_asize, asize);
2764 			mdb_nicenum(zb->zb_asize / zb->zb_count, avg);
2765 			(void) snprintfrac(comp, NICENUM_BUFLEN,
2766 			    zb->zb_lsize, zb->zb_psize, 2);
2767 			(void) snprintfrac(pct, NICENUM_BUFLEN,
2768 			    100 * zb->zb_asize, tzb->zb_asize, 2);
2769 
2770 			mdb_printf("%6s\t%5s\t%5s\t%5s\t%5s"
2771 			    "\t%5s\t%6s\t",
2772 			    csize, lsize, psize, asize, avg, comp, pct);
2773 
2774 			if (level == DN_MAX_LEVELS)
2775 				mdb_printf("%s\n", typename);
2776 			else
2777 				mdb_printf("  L%d %s\n",
2778 				    level, typename);
2779 		}
2780 	}
2781 
2782 	return (DCMD_OK);
2783 }
2784 
2785 typedef struct mdb_reference {
2786 	uintptr_t ref_holder;
2787 	uintptr_t ref_removed;
2788 	uint64_t ref_number;
2789 } mdb_reference_t;
2790 
2791 /* ARGSUSED */
2792 static int
2793 reference_cb(uintptr_t addr, const void *ignored, void *arg)
2794 {
2795 	mdb_reference_t ref;
2796 	boolean_t holder_is_str = B_FALSE;
2797 	char holder_str[128];
2798 	boolean_t removed = (boolean_t)arg;
2799 
2800 	if (mdb_ctf_vread(&ref, "reference_t", "mdb_reference_t", addr,
2801 	    0) == -1)
2802 		return (DCMD_ERR);
2803 
2804 	if (mdb_readstr(holder_str, sizeof (holder_str),
2805 	    ref.ref_holder) != -1)
2806 		holder_is_str = strisprint(holder_str);
2807 
2808 	if (removed)
2809 		mdb_printf("removed ");
2810 	mdb_printf("reference ");
2811 	if (ref.ref_number != 1)
2812 		mdb_printf("with count=%llu ", ref.ref_number);
2813 	mdb_printf("with tag %lx", ref.ref_holder);
2814 	if (holder_is_str)
2815 		mdb_printf(" \"%s\"", holder_str);
2816 	mdb_printf(", held at:\n");
2817 
2818 	(void) mdb_call_dcmd("whatis", addr, DCMD_ADDRSPEC, 0, NULL);
2819 
2820 	if (removed) {
2821 		mdb_printf("removed at:\n");
2822 		(void) mdb_call_dcmd("whatis", ref.ref_removed,
2823 		    DCMD_ADDRSPEC, 0, NULL);
2824 	}
2825 
2826 	mdb_printf("\n");
2827 
2828 	return (WALK_NEXT);
2829 }
2830 
2831 typedef struct mdb_refcount {
2832 	uint64_t rc_count;
2833 } mdb_refcount_t;
2834 
2835 typedef struct mdb_refcount_removed {
2836 	uint64_t rc_removed_count;
2837 } mdb_refcount_removed_t;
2838 
2839 typedef struct mdb_refcount_tracked {
2840 	boolean_t rc_tracked;
2841 } mdb_refcount_tracked_t;
2842 
2843 /* ARGSUSED */
2844 static int
2845 refcount(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
2846 {
2847 	mdb_refcount_t rc;
2848 	mdb_refcount_removed_t rcr;
2849 	mdb_refcount_tracked_t rct;
2850 	int off;
2851 	boolean_t released = B_FALSE;
2852 
2853 	if (!(flags & DCMD_ADDRSPEC))
2854 		return (DCMD_USAGE);
2855 
2856 	if (mdb_getopts(argc, argv,
2857 	    'r', MDB_OPT_SETBITS, B_TRUE, &released,
2858 	    NULL) != argc)
2859 		return (DCMD_USAGE);
2860 
2861 	if (mdb_ctf_vread(&rc, "refcount_t", "mdb_refcount_t", addr,
2862 	    0) == -1)
2863 		return (DCMD_ERR);
2864 
2865 	if (mdb_ctf_vread(&rcr, "refcount_t", "mdb_refcount_removed_t", addr,
2866 	    MDB_CTF_VREAD_QUIET) == -1) {
2867 		mdb_printf("refcount_t at %p has %llu holds (untracked)\n",
2868 		    addr, (longlong_t)rc.rc_count);
2869 		return (DCMD_OK);
2870 	}
2871 
2872 	if (mdb_ctf_vread(&rct, "refcount_t", "mdb_refcount_tracked_t", addr,
2873 	    MDB_CTF_VREAD_QUIET) == -1) {
2874 		/* If this is an old target, it might be tracked. */
2875 		rct.rc_tracked = B_TRUE;
2876 	}
2877 
2878 	mdb_printf("refcount_t at %p has %llu current holds, "
2879 	    "%llu recently released holds\n",
2880 	    addr, (longlong_t)rc.rc_count, (longlong_t)rcr.rc_removed_count);
2881 
2882 	if (rct.rc_tracked && rc.rc_count > 0)
2883 		mdb_printf("current holds:\n");
2884 	off = mdb_ctf_offsetof_by_name("refcount_t", "rc_list");
2885 	if (off == -1)
2886 		return (DCMD_ERR);
2887 	mdb_pwalk("list", reference_cb, (void*)B_FALSE, addr + off);
2888 
2889 	if (released && rcr.rc_removed_count > 0) {
2890 		mdb_printf("released holds:\n");
2891 
2892 		off = mdb_ctf_offsetof_by_name("refcount_t", "rc_removed");
2893 		if (off == -1)
2894 			return (DCMD_ERR);
2895 		mdb_pwalk("list", reference_cb, (void*)B_TRUE, addr + off);
2896 	}
2897 
2898 	return (DCMD_OK);
2899 }
2900 
2901 /* ARGSUSED */
2902 static int
2903 sa_attr_table(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
2904 {
2905 	sa_attr_table_t *table;
2906 	sa_os_t sa_os;
2907 	char *name;
2908 	int i;
2909 
2910 	if (mdb_vread(&sa_os, sizeof (sa_os_t), addr) == -1) {
2911 		mdb_warn("failed to read sa_os at %p", addr);
2912 		return (DCMD_ERR);
2913 	}
2914 
2915 	table = mdb_alloc(sizeof (sa_attr_table_t) * sa_os.sa_num_attrs,
2916 	    UM_SLEEP | UM_GC);
2917 	name = mdb_alloc(MAXPATHLEN, UM_SLEEP | UM_GC);
2918 
2919 	if (mdb_vread(table, sizeof (sa_attr_table_t) * sa_os.sa_num_attrs,
2920 	    (uintptr_t)sa_os.sa_attr_table) == -1) {
2921 		mdb_warn("failed to read sa_os at %p", addr);
2922 		return (DCMD_ERR);
2923 	}
2924 
2925 	mdb_printf("%<u>%-10s %-10s %-10s %-10s %s%</u>\n",
2926 	    "ATTR ID", "REGISTERED", "LENGTH", "BSWAP", "NAME");
2927 	for (i = 0; i != sa_os.sa_num_attrs; i++) {
2928 		mdb_readstr(name, MAXPATHLEN, (uintptr_t)table[i].sa_name);
2929 		mdb_printf("%5x   %8x %8x %8x          %-s\n",
2930 		    (int)table[i].sa_attr, (int)table[i].sa_registered,
2931 		    (int)table[i].sa_length, table[i].sa_byteswap, name);
2932 	}
2933 
2934 	return (DCMD_OK);
2935 }
2936 
2937 static int
2938 sa_get_off_table(uintptr_t addr, uint32_t **off_tab, int attr_count)
2939 {
2940 	uintptr_t idx_table;
2941 
2942 	if (GETMEMB(addr, "sa_idx_tab", sa_idx_tab, idx_table)) {
2943 		mdb_printf("can't find offset table in sa_idx_tab\n");
2944 		return (-1);
2945 	}
2946 
2947 	*off_tab = mdb_alloc(attr_count * sizeof (uint32_t),
2948 	    UM_SLEEP | UM_GC);
2949 
2950 	if (mdb_vread(*off_tab,
2951 	    attr_count * sizeof (uint32_t), idx_table) == -1) {
2952 		mdb_warn("failed to attribute offset table %p", idx_table);
2953 		return (-1);
2954 	}
2955 
2956 	return (DCMD_OK);
2957 }
2958 
2959 /*ARGSUSED*/
2960 static int
2961 sa_attr_print(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
2962 {
2963 	uint32_t *offset_tab;
2964 	int attr_count;
2965 	uint64_t attr_id;
2966 	uintptr_t attr_addr;
2967 	uintptr_t bonus_tab, spill_tab;
2968 	uintptr_t db_bonus, db_spill;
2969 	uintptr_t os, os_sa;
2970 	uintptr_t db_data;
2971 
2972 	if (argc != 1)
2973 		return (DCMD_USAGE);
2974 
2975 	if (argv[0].a_type == MDB_TYPE_STRING)
2976 		attr_id = mdb_strtoull(argv[0].a_un.a_str);
2977 	else
2978 		return (DCMD_USAGE);
2979 
2980 	if (GETMEMB(addr, "sa_handle", sa_bonus_tab, bonus_tab) ||
2981 	    GETMEMB(addr, "sa_handle", sa_spill_tab, spill_tab) ||
2982 	    GETMEMB(addr, "sa_handle", sa_os, os) ||
2983 	    GETMEMB(addr, "sa_handle", sa_bonus, db_bonus) ||
2984 	    GETMEMB(addr, "sa_handle", sa_spill, db_spill)) {
2985 		mdb_printf("Can't find necessary information in sa_handle "
2986 		    "in sa_handle\n");
2987 		return (DCMD_ERR);
2988 	}
2989 
2990 	if (GETMEMB(os, "objset", os_sa, os_sa)) {
2991 		mdb_printf("Can't find os_sa in objset\n");
2992 		return (DCMD_ERR);
2993 	}
2994 
2995 	if (GETMEMB(os_sa, "sa_os", sa_num_attrs, attr_count)) {
2996 		mdb_printf("Can't find sa_num_attrs\n");
2997 		return (DCMD_ERR);
2998 	}
2999 
3000 	if (attr_id > attr_count) {
3001 		mdb_printf("attribute id number is out of range\n");
3002 		return (DCMD_ERR);
3003 	}
3004 
3005 	if (bonus_tab) {
3006 		if (sa_get_off_table(bonus_tab, &offset_tab,
3007 		    attr_count) == -1) {
3008 			return (DCMD_ERR);
3009 		}
3010 
3011 		if (GETMEMB(db_bonus, "dmu_buf", db_data, db_data)) {
3012 			mdb_printf("can't find db_data in bonus dbuf\n");
3013 			return (DCMD_ERR);
3014 		}
3015 	}
3016 
3017 	if (bonus_tab && !TOC_ATTR_PRESENT(offset_tab[attr_id]) &&
3018 	    spill_tab == NULL) {
3019 		mdb_printf("Attribute does not exist\n");
3020 		return (DCMD_ERR);
3021 	} else if (!TOC_ATTR_PRESENT(offset_tab[attr_id]) && spill_tab) {
3022 		if (sa_get_off_table(spill_tab, &offset_tab,
3023 		    attr_count) == -1) {
3024 			return (DCMD_ERR);
3025 		}
3026 		if (GETMEMB(db_spill, "dmu_buf", db_data, db_data)) {
3027 			mdb_printf("can't find db_data in spill dbuf\n");
3028 			return (DCMD_ERR);
3029 		}
3030 		if (!TOC_ATTR_PRESENT(offset_tab[attr_id])) {
3031 			mdb_printf("Attribute does not exist\n");
3032 			return (DCMD_ERR);
3033 		}
3034 	}
3035 	attr_addr = db_data + TOC_OFF(offset_tab[attr_id]);
3036 	mdb_printf("%p\n", attr_addr);
3037 	return (DCMD_OK);
3038 }
3039 
3040 /* ARGSUSED */
3041 static int
3042 zfs_ace_print_common(uintptr_t addr, uint_t flags,
3043     uint64_t id, uint32_t access_mask, uint16_t ace_flags,
3044     uint16_t ace_type, int verbose)
3045 {
3046 	if (DCMD_HDRSPEC(flags) && !verbose)
3047 		mdb_printf("%<u>%-?s %-8s %-8s %-8s %s%</u>\n",
3048 		    "ADDR", "FLAGS", "MASK", "TYPE", "ID");
3049 
3050 	if (!verbose) {
3051 		mdb_printf("%0?p %-8x %-8x %-8x %-llx\n", addr,
3052 		    ace_flags, access_mask, ace_type, id);
3053 		return (DCMD_OK);
3054 	}
3055 
3056 	switch (ace_flags & ACE_TYPE_FLAGS) {
3057 	case ACE_OWNER:
3058 		mdb_printf("owner@:");
3059 		break;
3060 	case (ACE_IDENTIFIER_GROUP | ACE_GROUP):
3061 		mdb_printf("group@:");
3062 		break;
3063 	case ACE_EVERYONE:
3064 		mdb_printf("everyone@:");
3065 		break;
3066 	case ACE_IDENTIFIER_GROUP:
3067 		mdb_printf("group:%llx:", (u_longlong_t)id);
3068 		break;
3069 	case 0: /* User entry */
3070 		mdb_printf("user:%llx:", (u_longlong_t)id);
3071 		break;
3072 	}
3073 
3074 	/* print out permission mask */
3075 	if (access_mask & ACE_READ_DATA)
3076 		mdb_printf("r");
3077 	else
3078 		mdb_printf("-");
3079 	if (access_mask & ACE_WRITE_DATA)
3080 		mdb_printf("w");
3081 	else
3082 		mdb_printf("-");
3083 	if (access_mask & ACE_EXECUTE)
3084 		mdb_printf("x");
3085 	else
3086 		mdb_printf("-");
3087 	if (access_mask & ACE_APPEND_DATA)
3088 		mdb_printf("p");
3089 	else
3090 		mdb_printf("-");
3091 	if (access_mask & ACE_DELETE)
3092 		mdb_printf("d");
3093 	else
3094 		mdb_printf("-");
3095 	if (access_mask & ACE_DELETE_CHILD)
3096 		mdb_printf("D");
3097 	else
3098 		mdb_printf("-");
3099 	if (access_mask & ACE_READ_ATTRIBUTES)
3100 		mdb_printf("a");
3101 	else
3102 		mdb_printf("-");
3103 	if (access_mask & ACE_WRITE_ATTRIBUTES)
3104 		mdb_printf("A");
3105 	else
3106 		mdb_printf("-");
3107 	if (access_mask & ACE_READ_NAMED_ATTRS)
3108 		mdb_printf("R");
3109 	else
3110 		mdb_printf("-");
3111 	if (access_mask & ACE_WRITE_NAMED_ATTRS)
3112 		mdb_printf("W");
3113 	else
3114 		mdb_printf("-");
3115 	if (access_mask & ACE_READ_ACL)
3116 		mdb_printf("c");
3117 	else
3118 		mdb_printf("-");
3119 	if (access_mask & ACE_WRITE_ACL)
3120 		mdb_printf("C");
3121 	else
3122 		mdb_printf("-");
3123 	if (access_mask & ACE_WRITE_OWNER)
3124 		mdb_printf("o");
3125 	else
3126 		mdb_printf("-");
3127 	if (access_mask & ACE_SYNCHRONIZE)
3128 		mdb_printf("s");
3129 	else
3130 		mdb_printf("-");
3131 
3132 	mdb_printf(":");
3133 
3134 	/* Print out inheritance flags */
3135 	if (ace_flags & ACE_FILE_INHERIT_ACE)
3136 		mdb_printf("f");
3137 	else
3138 		mdb_printf("-");
3139 	if (ace_flags & ACE_DIRECTORY_INHERIT_ACE)
3140 		mdb_printf("d");
3141 	else
3142 		mdb_printf("-");
3143 	if (ace_flags & ACE_INHERIT_ONLY_ACE)
3144 		mdb_printf("i");
3145 	else
3146 		mdb_printf("-");
3147 	if (ace_flags & ACE_NO_PROPAGATE_INHERIT_ACE)
3148 		mdb_printf("n");
3149 	else
3150 		mdb_printf("-");
3151 	if (ace_flags & ACE_SUCCESSFUL_ACCESS_ACE_FLAG)
3152 		mdb_printf("S");
3153 	else
3154 		mdb_printf("-");
3155 	if (ace_flags & ACE_FAILED_ACCESS_ACE_FLAG)
3156 		mdb_printf("F");
3157 	else
3158 		mdb_printf("-");
3159 	if (ace_flags & ACE_INHERITED_ACE)
3160 		mdb_printf("I");
3161 	else
3162 		mdb_printf("-");
3163 
3164 	switch (ace_type) {
3165 	case ACE_ACCESS_ALLOWED_ACE_TYPE:
3166 		mdb_printf(":allow\n");
3167 		break;
3168 	case ACE_ACCESS_DENIED_ACE_TYPE:
3169 		mdb_printf(":deny\n");
3170 		break;
3171 	case ACE_SYSTEM_AUDIT_ACE_TYPE:
3172 		mdb_printf(":audit\n");
3173 		break;
3174 	case ACE_SYSTEM_ALARM_ACE_TYPE:
3175 		mdb_printf(":alarm\n");
3176 		break;
3177 	default:
3178 		mdb_printf(":?\n");
3179 	}
3180 	return (DCMD_OK);
3181 }
3182 
3183 /* ARGSUSED */
3184 static int
3185 zfs_ace_print(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
3186 {
3187 	zfs_ace_t zace;
3188 	int verbose = FALSE;
3189 	uint64_t id;
3190 
3191 	if (!(flags & DCMD_ADDRSPEC))
3192 		return (DCMD_USAGE);
3193 
3194 	if (mdb_getopts(argc, argv,
3195 	    'v', MDB_OPT_SETBITS, TRUE, &verbose, TRUE, NULL) != argc)
3196 		return (DCMD_USAGE);
3197 
3198 	if (mdb_vread(&zace, sizeof (zfs_ace_t), addr) == -1) {
3199 		mdb_warn("failed to read zfs_ace_t");
3200 		return (DCMD_ERR);
3201 	}
3202 
3203 	if ((zace.z_hdr.z_flags & ACE_TYPE_FLAGS) == 0 ||
3204 	    (zace.z_hdr.z_flags & ACE_TYPE_FLAGS) == ACE_IDENTIFIER_GROUP)
3205 		id = zace.z_fuid;
3206 	else
3207 		id = -1;
3208 
3209 	return (zfs_ace_print_common(addr, flags, id, zace.z_hdr.z_access_mask,
3210 	    zace.z_hdr.z_flags, zace.z_hdr.z_type, verbose));
3211 }
3212 
3213 /* ARGSUSED */
3214 static int
3215 zfs_ace0_print(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
3216 {
3217 	ace_t ace;
3218 	uint64_t id;
3219 	int verbose = FALSE;
3220 
3221 	if (!(flags & DCMD_ADDRSPEC))
3222 		return (DCMD_USAGE);
3223 
3224 	if (mdb_getopts(argc, argv,
3225 	    'v', MDB_OPT_SETBITS, TRUE, &verbose, TRUE, NULL) != argc)
3226 		return (DCMD_USAGE);
3227 
3228 	if (mdb_vread(&ace, sizeof (ace_t), addr) == -1) {
3229 		mdb_warn("failed to read ace_t");
3230 		return (DCMD_ERR);
3231 	}
3232 
3233 	if ((ace.a_flags & ACE_TYPE_FLAGS) == 0 ||
3234 	    (ace.a_flags & ACE_TYPE_FLAGS) == ACE_IDENTIFIER_GROUP)
3235 		id = ace.a_who;
3236 	else
3237 		id = -1;
3238 
3239 	return (zfs_ace_print_common(addr, flags, id, ace.a_access_mask,
3240 	    ace.a_flags, ace.a_type, verbose));
3241 }
3242 
3243 typedef struct acl_dump_args {
3244 	int a_argc;
3245 	const mdb_arg_t *a_argv;
3246 	uint16_t a_version;
3247 	int a_flags;
3248 } acl_dump_args_t;
3249 
3250 /* ARGSUSED */
3251 static int
3252 acl_aces_cb(uintptr_t addr, const void *unknown, void *arg)
3253 {
3254 	acl_dump_args_t *acl_args = (acl_dump_args_t *)arg;
3255 
3256 	if (acl_args->a_version == 1) {
3257 		if (mdb_call_dcmd("zfs_ace", addr,
3258 		    DCMD_ADDRSPEC|acl_args->a_flags, acl_args->a_argc,
3259 		    acl_args->a_argv) != DCMD_OK) {
3260 			return (WALK_ERR);
3261 		}
3262 	} else {
3263 		if (mdb_call_dcmd("zfs_ace0", addr,
3264 		    DCMD_ADDRSPEC|acl_args->a_flags, acl_args->a_argc,
3265 		    acl_args->a_argv) != DCMD_OK) {
3266 			return (WALK_ERR);
3267 		}
3268 	}
3269 	acl_args->a_flags = DCMD_LOOP;
3270 	return (WALK_NEXT);
3271 }
3272 
3273 /* ARGSUSED */
3274 static int
3275 acl_cb(uintptr_t addr, const void *unknown, void *arg)
3276 {
3277 	acl_dump_args_t *acl_args = (acl_dump_args_t *)arg;
3278 
3279 	if (acl_args->a_version == 1) {
3280 		if (mdb_pwalk("zfs_acl_node_aces", acl_aces_cb,
3281 		    arg, addr) != 0) {
3282 			mdb_warn("can't walk ACEs");
3283 			return (DCMD_ERR);
3284 		}
3285 	} else {
3286 		if (mdb_pwalk("zfs_acl_node_aces0", acl_aces_cb,
3287 		    arg, addr) != 0) {
3288 			mdb_warn("can't walk ACEs");
3289 			return (DCMD_ERR);
3290 		}
3291 	}
3292 	return (WALK_NEXT);
3293 }
3294 
3295 /* ARGSUSED */
3296 static int
3297 zfs_acl_dump(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
3298 {
3299 	zfs_acl_t zacl;
3300 	int verbose = FALSE;
3301 	acl_dump_args_t acl_args;
3302 
3303 	if (!(flags & DCMD_ADDRSPEC))
3304 		return (DCMD_USAGE);
3305 
3306 	if (mdb_getopts(argc, argv,
3307 	    'v', MDB_OPT_SETBITS, TRUE, &verbose, TRUE, NULL) != argc)
3308 		return (DCMD_USAGE);
3309 
3310 	if (mdb_vread(&zacl, sizeof (zfs_acl_t), addr) == -1) {
3311 		mdb_warn("failed to read zfs_acl_t");
3312 		return (DCMD_ERR);
3313 	}
3314 
3315 	acl_args.a_argc = argc;
3316 	acl_args.a_argv = argv;
3317 	acl_args.a_version = zacl.z_version;
3318 	acl_args.a_flags = DCMD_LOOPFIRST;
3319 
3320 	if (mdb_pwalk("zfs_acl_node", acl_cb, &acl_args, addr) != 0) {
3321 		mdb_warn("can't walk ACL");
3322 		return (DCMD_ERR);
3323 	}
3324 
3325 	return (DCMD_OK);
3326 }
3327 
3328 /* ARGSUSED */
3329 static int
3330 zfs_acl_node_walk_init(mdb_walk_state_t *wsp)
3331 {
3332 	if (wsp->walk_addr == NULL) {
3333 		mdb_warn("must supply address of zfs_acl_node_t\n");
3334 		return (WALK_ERR);
3335 	}
3336 
3337 	wsp->walk_addr +=
3338 	    mdb_ctf_offsetof_by_name(ZFS_STRUCT "zfs_acl", "z_acl");
3339 
3340 	if (mdb_layered_walk("list", wsp) == -1) {
3341 		mdb_warn("failed to walk 'list'\n");
3342 		return (WALK_ERR);
3343 	}
3344 
3345 	return (WALK_NEXT);
3346 }
3347 
3348 static int
3349 zfs_acl_node_walk_step(mdb_walk_state_t *wsp)
3350 {
3351 	zfs_acl_node_t	aclnode;
3352 
3353 	if (mdb_vread(&aclnode, sizeof (zfs_acl_node_t),
3354 	    wsp->walk_addr) == -1) {
3355 		mdb_warn("failed to read zfs_acl_node at %p", wsp->walk_addr);
3356 		return (WALK_ERR);
3357 	}
3358 
3359 	return (wsp->walk_callback(wsp->walk_addr, &aclnode, wsp->walk_cbdata));
3360 }
3361 
3362 typedef struct ace_walk_data {
3363 	int		ace_count;
3364 	int		ace_version;
3365 } ace_walk_data_t;
3366 
3367 static int
3368 zfs_aces_walk_init_common(mdb_walk_state_t *wsp, int version,
3369     int ace_count, uintptr_t ace_data)
3370 {
3371 	ace_walk_data_t *ace_walk_data;
3372 
3373 	if (wsp->walk_addr == NULL) {
3374 		mdb_warn("must supply address of zfs_acl_node_t\n");
3375 		return (WALK_ERR);
3376 	}
3377 
3378 	ace_walk_data = mdb_alloc(sizeof (ace_walk_data_t), UM_SLEEP | UM_GC);
3379 
3380 	ace_walk_data->ace_count = ace_count;
3381 	ace_walk_data->ace_version = version;
3382 
3383 	wsp->walk_addr = ace_data;
3384 	wsp->walk_data = ace_walk_data;
3385 
3386 	return (WALK_NEXT);
3387 }
3388 
3389 static int
3390 zfs_acl_node_aces_walk_init_common(mdb_walk_state_t *wsp, int version)
3391 {
3392 	static int gotid;
3393 	static mdb_ctf_id_t acl_id;
3394 	int z_ace_count;
3395 	uintptr_t z_acldata;
3396 
3397 	if (!gotid) {
3398 		if (mdb_ctf_lookup_by_name("struct zfs_acl_node",
3399 		    &acl_id) == -1) {
3400 			mdb_warn("couldn't find struct zfs_acl_node");
3401 			return (DCMD_ERR);
3402 		}
3403 		gotid = TRUE;
3404 	}
3405 
3406 	if (GETMEMBID(wsp->walk_addr, &acl_id, z_ace_count, z_ace_count)) {
3407 		return (DCMD_ERR);
3408 	}
3409 	if (GETMEMBID(wsp->walk_addr, &acl_id, z_acldata, z_acldata)) {
3410 		return (DCMD_ERR);
3411 	}
3412 
3413 	return (zfs_aces_walk_init_common(wsp, version,
3414 	    z_ace_count, z_acldata));
3415 }
3416 
3417 /* ARGSUSED */
3418 static int
3419 zfs_acl_node_aces_walk_init(mdb_walk_state_t *wsp)
3420 {
3421 	return (zfs_acl_node_aces_walk_init_common(wsp, 1));
3422 }
3423 
3424 /* ARGSUSED */
3425 static int
3426 zfs_acl_node_aces0_walk_init(mdb_walk_state_t *wsp)
3427 {
3428 	return (zfs_acl_node_aces_walk_init_common(wsp, 0));
3429 }
3430 
3431 static int
3432 zfs_aces_walk_step(mdb_walk_state_t *wsp)
3433 {
3434 	ace_walk_data_t *ace_data = wsp->walk_data;
3435 	zfs_ace_t zace;
3436 	ace_t *acep;
3437 	int status;
3438 	int entry_type;
3439 	int allow_type;
3440 	uintptr_t ptr;
3441 
3442 	if (ace_data->ace_count == 0)
3443 		return (WALK_DONE);
3444 
3445 	if (mdb_vread(&zace, sizeof (zfs_ace_t), wsp->walk_addr) == -1) {
3446 		mdb_warn("failed to read zfs_ace_t at %#lx",
3447 		    wsp->walk_addr);
3448 		return (WALK_ERR);
3449 	}
3450 
3451 	switch (ace_data->ace_version) {
3452 	case 0:
3453 		acep = (ace_t *)&zace;
3454 		entry_type = acep->a_flags & ACE_TYPE_FLAGS;
3455 		allow_type = acep->a_type;
3456 		break;
3457 	case 1:
3458 		entry_type = zace.z_hdr.z_flags & ACE_TYPE_FLAGS;
3459 		allow_type = zace.z_hdr.z_type;
3460 		break;
3461 	default:
3462 		return (WALK_ERR);
3463 	}
3464 
3465 	ptr = (uintptr_t)wsp->walk_addr;
3466 	switch (entry_type) {
3467 	case ACE_OWNER:
3468 	case ACE_EVERYONE:
3469 	case (ACE_IDENTIFIER_GROUP | ACE_GROUP):
3470 		ptr += ace_data->ace_version == 0 ?
3471 		    sizeof (ace_t) : sizeof (zfs_ace_hdr_t);
3472 		break;
3473 	case ACE_IDENTIFIER_GROUP:
3474 	default:
3475 		switch (allow_type) {
3476 		case ACE_ACCESS_ALLOWED_OBJECT_ACE_TYPE:
3477 		case ACE_ACCESS_DENIED_OBJECT_ACE_TYPE:
3478 		case ACE_SYSTEM_AUDIT_OBJECT_ACE_TYPE:
3479 		case ACE_SYSTEM_ALARM_OBJECT_ACE_TYPE:
3480 			ptr += ace_data->ace_version == 0 ?
3481 			    sizeof (ace_t) : sizeof (zfs_object_ace_t);
3482 			break;
3483 		default:
3484 			ptr += ace_data->ace_version == 0 ?
3485 			    sizeof (ace_t) : sizeof (zfs_ace_t);
3486 			break;
3487 		}
3488 	}
3489 
3490 	ace_data->ace_count--;
3491 	status = wsp->walk_callback(wsp->walk_addr,
3492 	    (void *)(uintptr_t)&zace, wsp->walk_cbdata);
3493 
3494 	wsp->walk_addr = ptr;
3495 	return (status);
3496 }
3497 
3498 typedef struct mdb_zfs_rrwlock {
3499 	uintptr_t	rr_writer;
3500 	boolean_t	rr_writer_wanted;
3501 } mdb_zfs_rrwlock_t;
3502 
3503 static uint_t rrw_key;
3504 
3505 /* ARGSUSED */
3506 static int
3507 rrwlock(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
3508 {
3509 	mdb_zfs_rrwlock_t rrw;
3510 
3511 	if (rrw_key == 0) {
3512 		if (mdb_ctf_readsym(&rrw_key, "uint_t", "rrw_tsd_key", 0) == -1)
3513 			return (DCMD_ERR);
3514 	}
3515 
3516 	if (mdb_ctf_vread(&rrw, "rrwlock_t", "mdb_zfs_rrwlock_t", addr,
3517 	    0) == -1)
3518 		return (DCMD_ERR);
3519 
3520 	if (rrw.rr_writer != 0) {
3521 		mdb_printf("write lock held by thread %lx\n", rrw.rr_writer);
3522 		return (DCMD_OK);
3523 	}
3524 
3525 	if (rrw.rr_writer_wanted) {
3526 		mdb_printf("writer wanted\n");
3527 	}
3528 
3529 	mdb_printf("anonymous references:\n");
3530 	(void) mdb_call_dcmd("refcount", addr +
3531 	    mdb_ctf_offsetof_by_name(ZFS_STRUCT "rrwlock", "rr_anon_rcount"),
3532 	    DCMD_ADDRSPEC, 0, NULL);
3533 
3534 	mdb_printf("linked references:\n");
3535 	(void) mdb_call_dcmd("refcount", addr +
3536 	    mdb_ctf_offsetof_by_name(ZFS_STRUCT "rrwlock", "rr_linked_rcount"),
3537 	    DCMD_ADDRSPEC, 0, NULL);
3538 
3539 	/*
3540 	 * XXX This should find references from
3541 	 * "::walk thread | ::tsd -v <rrw_key>", but there is no support
3542 	 * for programmatic consumption of dcmds, so this would be
3543 	 * difficult, potentially requiring reimplementing ::tsd (both
3544 	 * user and kernel versions) in this MDB module.
3545 	 */
3546 
3547 	return (DCMD_OK);
3548 }
3549 
3550 typedef struct mdb_arc_buf_hdr_t {
3551 	uint16_t b_psize;
3552 	uint16_t b_lsize;
3553 	struct {
3554 		uint32_t	b_bufcnt;
3555 		uintptr_t	b_state;
3556 		uintptr_t	b_pdata;
3557 	} b_l1hdr;
3558 } mdb_arc_buf_hdr_t;
3559 
3560 enum arc_cflags {
3561 	ARC_CFLAG_VERBOSE		= 1 << 0,
3562 	ARC_CFLAG_ANON			= 1 << 1,
3563 	ARC_CFLAG_MRU			= 1 << 2,
3564 	ARC_CFLAG_MFU			= 1 << 3,
3565 	ARC_CFLAG_BUFS			= 1 << 4,
3566 };
3567 
3568 typedef struct arc_compression_stats_data {
3569 	GElf_Sym anon_sym;	/* ARC_anon symbol */
3570 	GElf_Sym mru_sym;	/* ARC_mru symbol */
3571 	GElf_Sym mrug_sym;	/* ARC_mru_ghost symbol */
3572 	GElf_Sym mfu_sym;	/* ARC_mfu symbol */
3573 	GElf_Sym mfug_sym;	/* ARC_mfu_ghost symbol */
3574 	GElf_Sym l2c_sym;	/* ARC_l2c_only symbol */
3575 	uint64_t *anon_c_hist;	/* histogram of compressed sizes in anon */
3576 	uint64_t *anon_u_hist;	/* histogram of uncompressed sizes in anon */
3577 	uint64_t *anon_bufs;	/* histogram of buffer counts in anon state */
3578 	uint64_t *mru_c_hist;	/* histogram of compressed sizes in mru */
3579 	uint64_t *mru_u_hist;	/* histogram of uncompressed sizes in mru */
3580 	uint64_t *mru_bufs;	/* histogram of buffer counts in mru */
3581 	uint64_t *mfu_c_hist;	/* histogram of compressed sizes in mfu */
3582 	uint64_t *mfu_u_hist;	/* histogram of uncompressed sizes in mfu */
3583 	uint64_t *mfu_bufs;	/* histogram of buffer counts in mfu */
3584 	uint64_t *all_c_hist;	/* histogram of compressed anon + mru + mfu */
3585 	uint64_t *all_u_hist;	/* histogram of uncompressed anon + mru + mfu */
3586 	uint64_t *all_bufs;	/* histogram of buffer counts in all states  */
3587 	int arc_cflags;		/* arc compression flags, specified by user */
3588 	int hist_nbuckets;	/* number of buckets in each histogram */
3589 } arc_compression_stats_data_t;
3590 
3591 int
3592 highbit64(uint64_t i)
3593 {
3594 	int h = 1;
3595 
3596 	if (i == 0)
3597 		return (0);
3598 	if (i & 0xffffffff00000000ULL) {
3599 		h += 32; i >>= 32;
3600 	}
3601 	if (i & 0xffff0000) {
3602 		h += 16; i >>= 16;
3603 	}
3604 	if (i & 0xff00) {
3605 		h += 8; i >>= 8;
3606 	}
3607 	if (i & 0xf0) {
3608 		h += 4; i >>= 4;
3609 	}
3610 	if (i & 0xc) {
3611 		h += 2; i >>= 2;
3612 	}
3613 	if (i & 0x2) {
3614 		h += 1;
3615 	}
3616 	return (h);
3617 }
3618 
3619 /* ARGSUSED */
3620 static int
3621 arc_compression_stats_cb(uintptr_t addr, const void *unknown, void *arg)
3622 {
3623 	arc_compression_stats_data_t *data = arg;
3624 	mdb_arc_buf_hdr_t hdr;
3625 	int cbucket, ubucket, bufcnt;
3626 
3627 	if (mdb_ctf_vread(&hdr, "arc_buf_hdr_t", "mdb_arc_buf_hdr_t",
3628 	    addr, 0) == -1) {
3629 		return (WALK_ERR);
3630 	}
3631 
3632 	/*
3633 	 * Headers in the ghost states, or the l2c_only state don't have
3634 	 * arc buffers linked off of them. Thus, their compressed size
3635 	 * is meaningless, so we skip these from the stats.
3636 	 */
3637 	if (hdr.b_l1hdr.b_state == data->mrug_sym.st_value ||
3638 	    hdr.b_l1hdr.b_state == data->mfug_sym.st_value ||
3639 	    hdr.b_l1hdr.b_state == data->l2c_sym.st_value) {
3640 		return (WALK_NEXT);
3641 	}
3642 
3643 	/*
3644 	 * The physical size (compressed) and logical size
3645 	 * (uncompressed) are in units of SPA_MINBLOCKSIZE. By default,
3646 	 * we use the log2 of this value (rounded down to the nearest
3647 	 * integer) to determine the bucket to assign this header to.
3648 	 * Thus, the histogram is logarithmic with respect to the size
3649 	 * of the header. For example, the following is a mapping of the
3650 	 * bucket numbers and the range of header sizes they correspond to:
3651 	 *
3652 	 *	0: 0 byte headers
3653 	 *	1: 512 byte headers
3654 	 *	2: [1024 - 2048) byte headers
3655 	 *	3: [2048 - 4096) byte headers
3656 	 *	4: [4096 - 8192) byte headers
3657 	 *	5: [8192 - 16394) byte headers
3658 	 *	6: [16384 - 32768) byte headers
3659 	 *	7: [32768 - 65536) byte headers
3660 	 *	8: [65536 - 131072) byte headers
3661 	 *	9: 131072 byte headers
3662 	 *
3663 	 * If the ARC_CFLAG_VERBOSE flag was specified, we use the
3664 	 * physical and logical sizes directly. Thus, the histogram will
3665 	 * no longer be logarithmic; instead it will be linear with
3666 	 * respect to the size of the header. The following is a mapping
3667 	 * of the first many bucket numbers and the header size they
3668 	 * correspond to:
3669 	 *
3670 	 *	0: 0 byte headers
3671 	 *	1: 512 byte headers
3672 	 *	2: 1024 byte headers
3673 	 *	3: 1536 byte headers
3674 	 *	4: 2048 byte headers
3675 	 *	5: 2560 byte headers
3676 	 *	6: 3072 byte headers
3677 	 *
3678 	 * And so on. Keep in mind that a range of sizes isn't used in
3679 	 * the case of linear scale because the headers can only
3680 	 * increment or decrement in sizes of 512 bytes. So, it's not
3681 	 * possible for a header to be sized in between whats listed
3682 	 * above.
3683 	 *
3684 	 * Also, the above mapping values were calculated assuming a
3685 	 * SPA_MINBLOCKSHIFT of 512 bytes and a SPA_MAXBLOCKSIZE of 128K.
3686 	 */
3687 
3688 	if (data->arc_cflags & ARC_CFLAG_VERBOSE) {
3689 		cbucket = hdr.b_psize;
3690 		ubucket = hdr.b_lsize;
3691 	} else {
3692 		cbucket = highbit64(hdr.b_psize);
3693 		ubucket = highbit64(hdr.b_lsize);
3694 	}
3695 
3696 	bufcnt = hdr.b_l1hdr.b_bufcnt;
3697 	if (bufcnt >= data->hist_nbuckets)
3698 		bufcnt = data->hist_nbuckets - 1;
3699 
3700 	/* Ensure we stay within the bounds of the histogram array */
3701 	ASSERT3U(cbucket, <, data->hist_nbuckets);
3702 	ASSERT3U(ubucket, <, data->hist_nbuckets);
3703 
3704 	if (hdr.b_l1hdr.b_state == data->anon_sym.st_value) {
3705 		data->anon_c_hist[cbucket]++;
3706 		data->anon_u_hist[ubucket]++;
3707 		data->anon_bufs[bufcnt]++;
3708 	} else if (hdr.b_l1hdr.b_state == data->mru_sym.st_value) {
3709 		data->mru_c_hist[cbucket]++;
3710 		data->mru_u_hist[ubucket]++;
3711 		data->mru_bufs[bufcnt]++;
3712 	} else if (hdr.b_l1hdr.b_state == data->mfu_sym.st_value) {
3713 		data->mfu_c_hist[cbucket]++;
3714 		data->mfu_u_hist[ubucket]++;
3715 		data->mfu_bufs[bufcnt]++;
3716 	}
3717 
3718 	data->all_c_hist[cbucket]++;
3719 	data->all_u_hist[ubucket]++;
3720 	data->all_bufs[bufcnt]++;
3721 
3722 	return (WALK_NEXT);
3723 }
3724 
3725 /* ARGSUSED */
3726 static int
3727 arc_compression_stats(uintptr_t addr, uint_t flags, int argc,
3728     const mdb_arg_t *argv)
3729 {
3730 	arc_compression_stats_data_t data = { 0 };
3731 	unsigned int max_shifted = SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT;
3732 	unsigned int hist_size;
3733 	char range[32];
3734 	int rc = DCMD_OK;
3735 
3736 	if (mdb_getopts(argc, argv,
3737 	    'v', MDB_OPT_SETBITS, ARC_CFLAG_VERBOSE, &data.arc_cflags,
3738 	    'a', MDB_OPT_SETBITS, ARC_CFLAG_ANON, &data.arc_cflags,
3739 	    'b', MDB_OPT_SETBITS, ARC_CFLAG_BUFS, &data.arc_cflags,
3740 	    'r', MDB_OPT_SETBITS, ARC_CFLAG_MRU, &data.arc_cflags,
3741 	    'f', MDB_OPT_SETBITS, ARC_CFLAG_MFU, &data.arc_cflags) != argc)
3742 		return (DCMD_USAGE);
3743 
3744 	if (mdb_lookup_by_obj(ZFS_OBJ_NAME, "ARC_anon", &data.anon_sym) ||
3745 	    mdb_lookup_by_obj(ZFS_OBJ_NAME, "ARC_mru", &data.mru_sym) ||
3746 	    mdb_lookup_by_obj(ZFS_OBJ_NAME, "ARC_mru_ghost", &data.mrug_sym) ||
3747 	    mdb_lookup_by_obj(ZFS_OBJ_NAME, "ARC_mfu", &data.mfu_sym) ||
3748 	    mdb_lookup_by_obj(ZFS_OBJ_NAME, "ARC_mfu_ghost", &data.mfug_sym) ||
3749 	    mdb_lookup_by_obj(ZFS_OBJ_NAME, "ARC_l2c_only", &data.l2c_sym)) {
3750 		mdb_warn("can't find arc state symbol");
3751 		return (DCMD_ERR);
3752 	}
3753 
3754 	/*
3755 	 * Determine the maximum expected size for any header, and use
3756 	 * this to determine the number of buckets needed for each
3757 	 * histogram. If ARC_CFLAG_VERBOSE is specified, this value is
3758 	 * used directly; otherwise the log2 of the maximum size is
3759 	 * used. Thus, if using a log2 scale there's a maximum of 10
3760 	 * possible buckets, while the linear scale (when using
3761 	 * ARC_CFLAG_VERBOSE) has a maximum of 257 buckets.
3762 	 */
3763 	if (data.arc_cflags & ARC_CFLAG_VERBOSE)
3764 		data.hist_nbuckets = max_shifted + 1;
3765 	else
3766 		data.hist_nbuckets = highbit64(max_shifted) + 1;
3767 
3768 	hist_size = sizeof (uint64_t) * data.hist_nbuckets;
3769 
3770 	data.anon_c_hist = mdb_zalloc(hist_size, UM_SLEEP);
3771 	data.anon_u_hist = mdb_zalloc(hist_size, UM_SLEEP);
3772 	data.anon_bufs = mdb_zalloc(hist_size, UM_SLEEP);
3773 
3774 	data.mru_c_hist = mdb_zalloc(hist_size, UM_SLEEP);
3775 	data.mru_u_hist = mdb_zalloc(hist_size, UM_SLEEP);
3776 	data.mru_bufs = mdb_zalloc(hist_size, UM_SLEEP);
3777 
3778 	data.mfu_c_hist = mdb_zalloc(hist_size, UM_SLEEP);
3779 	data.mfu_u_hist = mdb_zalloc(hist_size, UM_SLEEP);
3780 	data.mfu_bufs = mdb_zalloc(hist_size, UM_SLEEP);
3781 
3782 	data.all_c_hist = mdb_zalloc(hist_size, UM_SLEEP);
3783 	data.all_u_hist = mdb_zalloc(hist_size, UM_SLEEP);
3784 	data.all_bufs = mdb_zalloc(hist_size, UM_SLEEP);
3785 
3786 	if (mdb_walk("arc_buf_hdr_t_full", arc_compression_stats_cb,
3787 	    &data) != 0) {
3788 		mdb_warn("can't walk arc_buf_hdr's");
3789 		rc = DCMD_ERR;
3790 		goto out;
3791 	}
3792 
3793 	if (data.arc_cflags & ARC_CFLAG_VERBOSE) {
3794 		rc = mdb_snprintf(range, sizeof (range),
3795 		    "[n*%llu, (n+1)*%llu)", SPA_MINBLOCKSIZE,
3796 		    SPA_MINBLOCKSIZE);
3797 	} else {
3798 		rc = mdb_snprintf(range, sizeof (range),
3799 		    "[2^(n-1)*%llu, 2^n*%llu)", SPA_MINBLOCKSIZE,
3800 		    SPA_MINBLOCKSIZE);
3801 	}
3802 
3803 	if (rc < 0) {
3804 		/* snprintf failed, abort the dcmd */
3805 		rc = DCMD_ERR;
3806 		goto out;
3807 	} else {
3808 		/* snprintf succeeded above, reset return code */
3809 		rc = DCMD_OK;
3810 	}
3811 
3812 	if (data.arc_cflags & ARC_CFLAG_ANON) {
3813 		if (data.arc_cflags & ARC_CFLAG_BUFS) {
3814 			mdb_printf("Histogram of the number of anon buffers "
3815 			    "that are associated with an arc hdr.\n");
3816 			dump_histogram(data.anon_bufs, data.hist_nbuckets, 0);
3817 			mdb_printf("\n");
3818 		}
3819 		mdb_printf("Histogram of compressed anon buffers.\n"
3820 		    "Each bucket represents buffers of size: %s.\n", range);
3821 		dump_histogram(data.anon_c_hist, data.hist_nbuckets, 0);
3822 		mdb_printf("\n");
3823 
3824 		mdb_printf("Histogram of uncompressed anon buffers.\n"
3825 		    "Each bucket represents buffers of size: %s.\n", range);
3826 		dump_histogram(data.anon_u_hist, data.hist_nbuckets, 0);
3827 		mdb_printf("\n");
3828 	}
3829 
3830 	if (data.arc_cflags & ARC_CFLAG_MRU) {
3831 		if (data.arc_cflags & ARC_CFLAG_BUFS) {
3832 			mdb_printf("Histogram of the number of mru buffers "
3833 			    "that are associated with an arc hdr.\n");
3834 			dump_histogram(data.mru_bufs, data.hist_nbuckets, 0);
3835 			mdb_printf("\n");
3836 		}
3837 		mdb_printf("Histogram of compressed mru buffers.\n"
3838 		    "Each bucket represents buffers of size: %s.\n", range);
3839 		dump_histogram(data.mru_c_hist, data.hist_nbuckets, 0);
3840 		mdb_printf("\n");
3841 
3842 		mdb_printf("Histogram of uncompressed mru buffers.\n"
3843 		    "Each bucket represents buffers of size: %s.\n", range);
3844 		dump_histogram(data.mru_u_hist, data.hist_nbuckets, 0);
3845 		mdb_printf("\n");
3846 	}
3847 
3848 	if (data.arc_cflags & ARC_CFLAG_MFU) {
3849 		if (data.arc_cflags & ARC_CFLAG_BUFS) {
3850 			mdb_printf("Histogram of the number of mfu buffers "
3851 			    "that are associated with an arc hdr.\n");
3852 			dump_histogram(data.mfu_bufs, data.hist_nbuckets, 0);
3853 			mdb_printf("\n");
3854 		}
3855 
3856 		mdb_printf("Histogram of compressed mfu buffers.\n"
3857 		    "Each bucket represents buffers of size: %s.\n", range);
3858 		dump_histogram(data.mfu_c_hist, data.hist_nbuckets, 0);
3859 		mdb_printf("\n");
3860 
3861 		mdb_printf("Histogram of uncompressed mfu buffers.\n"
3862 		    "Each bucket represents buffers of size: %s.\n", range);
3863 		dump_histogram(data.mfu_u_hist, data.hist_nbuckets, 0);
3864 		mdb_printf("\n");
3865 	}
3866 
3867 	if (data.arc_cflags & ARC_CFLAG_BUFS) {
3868 		mdb_printf("Histogram of all buffers that "
3869 		    "are associated with an arc hdr.\n");
3870 		dump_histogram(data.all_bufs, data.hist_nbuckets, 0);
3871 		mdb_printf("\n");
3872 	}
3873 
3874 	mdb_printf("Histogram of all compressed buffers.\n"
3875 	    "Each bucket represents buffers of size: %s.\n", range);
3876 	dump_histogram(data.all_c_hist, data.hist_nbuckets, 0);
3877 	mdb_printf("\n");
3878 
3879 	mdb_printf("Histogram of all uncompressed buffers.\n"
3880 	    "Each bucket represents buffers of size: %s.\n", range);
3881 	dump_histogram(data.all_u_hist, data.hist_nbuckets, 0);
3882 
3883 out:
3884 	mdb_free(data.anon_c_hist, hist_size);
3885 	mdb_free(data.anon_u_hist, hist_size);
3886 	mdb_free(data.anon_bufs, hist_size);
3887 
3888 	mdb_free(data.mru_c_hist, hist_size);
3889 	mdb_free(data.mru_u_hist, hist_size);
3890 	mdb_free(data.mru_bufs, hist_size);
3891 
3892 	mdb_free(data.mfu_c_hist, hist_size);
3893 	mdb_free(data.mfu_u_hist, hist_size);
3894 	mdb_free(data.mfu_bufs, hist_size);
3895 
3896 	mdb_free(data.all_c_hist, hist_size);
3897 	mdb_free(data.all_u_hist, hist_size);
3898 	mdb_free(data.all_bufs, hist_size);
3899 
3900 	return (rc);
3901 }
3902 
3903 /*
3904  * MDB module linkage information:
3905  *
3906  * We declare a list of structures describing our dcmds, and a function
3907  * named _mdb_init to return a pointer to our module information.
3908  */
3909 
3910 static const mdb_dcmd_t dcmds[] = {
3911 	{ "arc", "[-bkmg]", "print ARC variables", arc_print },
3912 	{ "blkptr", ":", "print blkptr_t", blkptr },
3913 	{ "dbuf", ":", "print dmu_buf_impl_t", dbuf },
3914 	{ "dbuf_stats", ":", "dbuf stats", dbuf_stats },
3915 	{ "dbufs",
3916 	    "\t[-O objset_t*] [-n objset_name | \"mos\"] "
3917 	    "[-o object | \"mdn\"] \n"
3918 	    "\t[-l level] [-b blkid | \"bonus\"]",
3919 	    "find dmu_buf_impl_t's that match specified criteria", dbufs },
3920 	{ "abuf_find", "dva_word[0] dva_word[1]",
3921 	    "find arc_buf_hdr_t of a specified DVA",
3922 	    abuf_find },
3923 	{ "spa", "?[-cevmMh]\n"
3924 	    "\t-c display spa config\n"
3925 	    "\t-e display vdev statistics\n"
3926 	    "\t-v display vdev information\n"
3927 	    "\t-m display metaslab statistics\n"
3928 	    "\t-M display metaslab group statistics\n"
3929 	    "\t-h display histogram (requires -m or -M)\n",
3930 	    "spa_t summary", spa_print },
3931 	{ "spa_config", ":", "print spa_t configuration", spa_print_config },
3932 	{ "spa_space", ":[-b]", "print spa_t on-disk space usage", spa_space },
3933 	{ "spa_vdevs", ":[-emMh]\n"
3934 	    "\t-e display vdev statistics\n"
3935 	    "\t-m dispaly metaslab statistics\n"
3936 	    "\t-M display metaslab group statistic\n"
3937 	    "\t-h display histogram (requires -m or -M)\n",
3938 	    "given a spa_t, print vdev summary", spa_vdevs },
3939 	{ "vdev", ":[-remMh]\n"
3940 	    "\t-r display recursively\n"
3941 	    "\t-e display statistics\n"
3942 	    "\t-m display metaslab statistics (top level vdev only)\n"
3943 	    "\t-M display metaslab group statistics (top level vdev only)\n"
3944 	    "\t-h display histogram (requires -m or -M)\n",
3945 	    "vdev_t summary", vdev_print },
3946 	{ "zio", ":[-cpr]\n"
3947 	    "\t-c display children\n"
3948 	    "\t-p display parents\n"
3949 	    "\t-r display recursively",
3950 	    "zio_t summary", zio_print },
3951 	{ "zio_state", "?", "print out all zio_t structures on system or "
3952 	    "for a particular pool", zio_state },
3953 	{ "zfs_blkstats", ":[-v]",
3954 	    "given a spa_t, print block type stats from last scrub",
3955 	    zfs_blkstats },
3956 	{ "zfs_params", "", "print zfs tunable parameters", zfs_params },
3957 	{ "refcount", ":[-r]\n"
3958 	    "\t-r display recently removed references",
3959 	    "print refcount_t holders", refcount },
3960 	{ "zap_leaf", "", "print zap_leaf_phys_t", zap_leaf },
3961 	{ "zfs_aces", ":[-v]", "print all ACEs from a zfs_acl_t",
3962 	    zfs_acl_dump },
3963 	{ "zfs_ace", ":[-v]", "print zfs_ace", zfs_ace_print },
3964 	{ "zfs_ace0", ":[-v]", "print zfs_ace0", zfs_ace0_print },
3965 	{ "sa_attr_table", ":", "print SA attribute table from sa_os_t",
3966 	    sa_attr_table},
3967 	{ "sa_attr", ": attr_id",
3968 	    "print SA attribute address when given sa_handle_t", sa_attr_print},
3969 	{ "zfs_dbgmsg", ":[-va]",
3970 	    "print zfs debug log", dbgmsg},
3971 	{ "rrwlock", ":",
3972 	    "print rrwlock_t, including readers", rrwlock},
3973 	{ "metaslab_weight", "weight",
3974 	    "print metaslab weight", metaslab_weight},
3975 	{ "metaslab_trace", ":",
3976 	    "print metaslab allocation trace records", metaslab_trace},
3977 	{ "arc_compression_stats", ":[-vabrf]\n"
3978 	    "\t-v verbose, display a linearly scaled histogram\n"
3979 	    "\t-a display ARC_anon state statistics individually\n"
3980 	    "\t-r display ARC_mru state statistics individually\n"
3981 	    "\t-f display ARC_mfu state statistics individually\n"
3982 	    "\t-b display histogram of buffer counts\n",
3983 	    "print a histogram of compressed arc buffer sizes",
3984 	    arc_compression_stats},
3985 	{ NULL }
3986 };
3987 
3988 static const mdb_walker_t walkers[] = {
3989 	{ "zms_freelist", "walk ZFS metaslab freelist",
3990 	    freelist_walk_init, freelist_walk_step, NULL },
3991 	{ "txg_list", "given any txg_list_t *, walk all entries in all txgs",
3992 	    txg_list_walk_init, txg_list_walk_step, NULL },
3993 	{ "txg_list0", "given any txg_list_t *, walk all entries in txg 0",
3994 	    txg_list0_walk_init, txg_list_walk_step, NULL },
3995 	{ "txg_list1", "given any txg_list_t *, walk all entries in txg 1",
3996 	    txg_list1_walk_init, txg_list_walk_step, NULL },
3997 	{ "txg_list2", "given any txg_list_t *, walk all entries in txg 2",
3998 	    txg_list2_walk_init, txg_list_walk_step, NULL },
3999 	{ "txg_list3", "given any txg_list_t *, walk all entries in txg 3",
4000 	    txg_list3_walk_init, txg_list_walk_step, NULL },
4001 	{ "zio", "walk all zio structures, optionally for a particular spa_t",
4002 	    zio_walk_init, zio_walk_step, NULL },
4003 	{ "zio_root",
4004 	    "walk all root zio_t structures, optionally for a particular spa_t",
4005 	    zio_walk_init, zio_walk_root_step, NULL },
4006 	{ "spa", "walk all spa_t entries in the namespace",
4007 	    spa_walk_init, spa_walk_step, NULL },
4008 	{ "metaslab", "given a spa_t *, walk all metaslab_t structures",
4009 	    metaslab_walk_init, metaslab_walk_step, NULL },
4010 	{ "multilist", "given a multilist_t *, walk all list_t structures",
4011 	    multilist_walk_init, multilist_walk_step, NULL },
4012 	{ "zfs_acl_node", "given a zfs_acl_t, walk all zfs_acl_nodes",
4013 	    zfs_acl_node_walk_init, zfs_acl_node_walk_step, NULL },
4014 	{ "zfs_acl_node_aces", "given a zfs_acl_node_t, walk all ACEs",
4015 	    zfs_acl_node_aces_walk_init, zfs_aces_walk_step, NULL },
4016 	{ "zfs_acl_node_aces0",
4017 	    "given a zfs_acl_node_t, walk all ACEs as ace_t",
4018 	    zfs_acl_node_aces0_walk_init, zfs_aces_walk_step, NULL },
4019 	{ NULL }
4020 };
4021 
4022 static const mdb_modinfo_t modinfo = {
4023 	MDB_API_VERSION, dcmds, walkers
4024 };
4025 
4026 const mdb_modinfo_t *
4027 _mdb_init(void)
4028 {
4029 	return (&modinfo);
4030 }
4031