xref: /titanic_41/usr/src/cmd/mdb/common/modules/zfs/zfs.c (revision aed5247ff899ec457005d93dfbdb4ffd74574695)
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) 2013 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 
46 #ifdef _KERNEL
47 #define	ZFS_OBJ_NAME	"zfs"
48 extern int64_t mdb_gethrtime(void);
49 #else
50 #define	ZFS_OBJ_NAME	"libzpool.so.1"
51 #endif
52 
53 #define	ZFS_STRUCT	"struct " ZFS_OBJ_NAME "`"
54 
55 #ifndef _KERNEL
56 int aok;
57 #endif
58 
59 static int
60 getmember(uintptr_t addr, const char *type, mdb_ctf_id_t *idp,
61     const char *member, int len, void *buf)
62 {
63 	mdb_ctf_id_t id;
64 	ulong_t off;
65 	char name[64];
66 
67 	if (idp == NULL) {
68 		if (mdb_ctf_lookup_by_name(type, &id) == -1) {
69 			mdb_warn("couldn't find type %s", type);
70 			return (DCMD_ERR);
71 		}
72 		idp = &id;
73 	} else {
74 		type = name;
75 		mdb_ctf_type_name(*idp, name, sizeof (name));
76 	}
77 
78 	if (mdb_ctf_offsetof(*idp, member, &off) == -1) {
79 		mdb_warn("couldn't find member %s of type %s\n", member, type);
80 		return (DCMD_ERR);
81 	}
82 	if (off % 8 != 0) {
83 		mdb_warn("member %s of type %s is unsupported bitfield",
84 		    member, type);
85 		return (DCMD_ERR);
86 	}
87 	off /= 8;
88 
89 	if (mdb_vread(buf, len, addr + off) == -1) {
90 		mdb_warn("failed to read %s from %s at %p",
91 		    member, type, addr + off);
92 		return (DCMD_ERR);
93 	}
94 	/* mdb_warn("read %s from %s at %p+%llx\n", member, type, addr, off); */
95 
96 	return (0);
97 }
98 
99 #define	GETMEMB(addr, structname, member, dest) \
100 	getmember(addr, ZFS_STRUCT structname, NULL, #member, \
101 	sizeof (dest), &(dest))
102 
103 #define	GETMEMBID(addr, ctfid, member, dest) \
104 	getmember(addr, NULL, ctfid, #member, sizeof (dest), &(dest))
105 
106 static boolean_t
107 strisprint(const char *cp)
108 {
109 	for (; *cp; cp++) {
110 		if (!isprint(*cp))
111 			return (B_FALSE);
112 	}
113 	return (B_TRUE);
114 }
115 
116 static int verbose;
117 
118 static int
119 freelist_walk_init(mdb_walk_state_t *wsp)
120 {
121 	if (wsp->walk_addr == NULL) {
122 		mdb_warn("must supply starting address\n");
123 		return (WALK_ERR);
124 	}
125 
126 	wsp->walk_data = 0;  /* Index into the freelist */
127 	return (WALK_NEXT);
128 }
129 
130 static int
131 freelist_walk_step(mdb_walk_state_t *wsp)
132 {
133 	uint64_t entry;
134 	uintptr_t number = (uintptr_t)wsp->walk_data;
135 	char *ddata[] = { "ALLOC", "FREE", "CONDENSE", "INVALID",
136 			    "INVALID", "INVALID", "INVALID", "INVALID" };
137 	int mapshift = SPA_MINBLOCKSHIFT;
138 
139 	if (mdb_vread(&entry, sizeof (entry), wsp->walk_addr) == -1) {
140 		mdb_warn("failed to read freelist entry %p", wsp->walk_addr);
141 		return (WALK_DONE);
142 	}
143 	wsp->walk_addr += sizeof (entry);
144 	wsp->walk_data = (void *)(number + 1);
145 
146 	if (SM_DEBUG_DECODE(entry)) {
147 		mdb_printf("DEBUG: %3u  %10s: txg=%llu  pass=%llu\n",
148 		    number,
149 		    ddata[SM_DEBUG_ACTION_DECODE(entry)],
150 		    SM_DEBUG_TXG_DECODE(entry),
151 		    SM_DEBUG_SYNCPASS_DECODE(entry));
152 	} else {
153 		mdb_printf("Entry: %3u  offsets=%08llx-%08llx  type=%c  "
154 		    "size=%06llx", number,
155 		    SM_OFFSET_DECODE(entry) << mapshift,
156 		    (SM_OFFSET_DECODE(entry) + SM_RUN_DECODE(entry)) <<
157 		    mapshift,
158 		    SM_TYPE_DECODE(entry) == SM_ALLOC ? 'A' : 'F',
159 		    SM_RUN_DECODE(entry) << mapshift);
160 		if (verbose)
161 			mdb_printf("      (raw=%012llx)\n", entry);
162 		mdb_printf("\n");
163 	}
164 	return (WALK_NEXT);
165 }
166 
167 static int
168 mdb_dsl_dir_name(uintptr_t addr, char *buf)
169 {
170 	static int gotid;
171 	static mdb_ctf_id_t dd_id;
172 	uintptr_t dd_parent;
173 	char dd_myname[MAXNAMELEN];
174 
175 	if (!gotid) {
176 		if (mdb_ctf_lookup_by_name(ZFS_STRUCT "dsl_dir",
177 		    &dd_id) == -1) {
178 			mdb_warn("couldn't find struct dsl_dir");
179 			return (DCMD_ERR);
180 		}
181 		gotid = TRUE;
182 	}
183 	if (GETMEMBID(addr, &dd_id, dd_parent, dd_parent) ||
184 	    GETMEMBID(addr, &dd_id, dd_myname, dd_myname)) {
185 		return (DCMD_ERR);
186 	}
187 
188 	if (dd_parent) {
189 		if (mdb_dsl_dir_name(dd_parent, buf))
190 			return (DCMD_ERR);
191 		strcat(buf, "/");
192 	}
193 
194 	if (dd_myname[0])
195 		strcat(buf, dd_myname);
196 	else
197 		strcat(buf, "???");
198 
199 	return (0);
200 }
201 
202 static int
203 objset_name(uintptr_t addr, char *buf)
204 {
205 	static int gotid;
206 	static mdb_ctf_id_t os_id, ds_id;
207 	uintptr_t os_dsl_dataset;
208 	char ds_snapname[MAXNAMELEN];
209 	uintptr_t ds_dir;
210 
211 	buf[0] = '\0';
212 
213 	if (!gotid) {
214 		if (mdb_ctf_lookup_by_name(ZFS_STRUCT "objset",
215 		    &os_id) == -1) {
216 			mdb_warn("couldn't find struct objset");
217 			return (DCMD_ERR);
218 		}
219 		if (mdb_ctf_lookup_by_name(ZFS_STRUCT "dsl_dataset",
220 		    &ds_id) == -1) {
221 			mdb_warn("couldn't find struct dsl_dataset");
222 			return (DCMD_ERR);
223 		}
224 
225 		gotid = TRUE;
226 	}
227 
228 	if (GETMEMBID(addr, &os_id, os_dsl_dataset, os_dsl_dataset))
229 		return (DCMD_ERR);
230 
231 	if (os_dsl_dataset == 0) {
232 		strcat(buf, "mos");
233 		return (0);
234 	}
235 
236 	if (GETMEMBID(os_dsl_dataset, &ds_id, ds_snapname, ds_snapname) ||
237 	    GETMEMBID(os_dsl_dataset, &ds_id, ds_dir, ds_dir)) {
238 		return (DCMD_ERR);
239 	}
240 
241 	if (ds_dir && mdb_dsl_dir_name(ds_dir, buf))
242 		return (DCMD_ERR);
243 
244 	if (ds_snapname[0]) {
245 		strcat(buf, "@");
246 		strcat(buf, ds_snapname);
247 	}
248 	return (0);
249 }
250 
251 static void
252 enum_lookup(char *out, size_t size, mdb_ctf_id_t id, int val,
253     const char *prefix)
254 {
255 	const char *cp;
256 	size_t len = strlen(prefix);
257 
258 	if ((cp = mdb_ctf_enum_name(id, val)) != NULL) {
259 		if (strncmp(cp, prefix, len) == 0)
260 			cp += len;
261 		(void) strncpy(out, cp, size);
262 	} else {
263 		mdb_snprintf(out, size, "? (%d)", val);
264 	}
265 }
266 
267 /* ARGSUSED */
268 static int
269 zfs_params(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
270 {
271 	/*
272 	 * This table can be approximately generated by running:
273 	 * egrep "^[a-z0-9_]+ [a-z0-9_]+( =.*)?;" *.c | cut -d ' ' -f 2
274 	 */
275 	static const char *params[] = {
276 		"arc_reduce_dnlc_percent",
277 		"arc_lotsfree_percent",
278 		"zfs_dirty_data_max",
279 		"zfs_dirty_data_sync",
280 		"zfs_delay_max_ns",
281 		"zfs_delay_min_dirty_percent",
282 		"zfs_delay_scale",
283 		"zfs_vdev_max_active",
284 		"zfs_vdev_sync_read_min_active",
285 		"zfs_vdev_sync_read_max_active",
286 		"zfs_vdev_sync_write_min_active",
287 		"zfs_vdev_sync_write_max_active",
288 		"zfs_vdev_async_read_min_active",
289 		"zfs_vdev_async_read_max_active",
290 		"zfs_vdev_async_write_min_active",
291 		"zfs_vdev_async_write_max_active",
292 		"zfs_vdev_scrub_min_active",
293 		"zfs_vdev_scrub_max_active",
294 		"zfs_vdev_async_write_active_min_dirty_percent",
295 		"zfs_vdev_async_write_active_max_dirty_percent",
296 		"spa_asize_inflation",
297 		"zfs_arc_max",
298 		"zfs_arc_min",
299 		"arc_shrink_shift",
300 		"zfs_mdcomp_disable",
301 		"zfs_prefetch_disable",
302 		"zfetch_max_streams",
303 		"zfetch_min_sec_reap",
304 		"zfetch_block_cap",
305 		"zfetch_array_rd_sz",
306 		"zfs_default_bs",
307 		"zfs_default_ibs",
308 		"metaslab_aliquot",
309 		"reference_tracking_enable",
310 		"reference_history",
311 		"spa_max_replication_override",
312 		"spa_mode_global",
313 		"zfs_flags",
314 		"zfs_txg_timeout",
315 		"zfs_vdev_cache_max",
316 		"zfs_vdev_cache_size",
317 		"zfs_vdev_cache_bshift",
318 		"vdev_mirror_shift",
319 		"zfs_scrub_limit",
320 		"zfs_no_scrub_io",
321 		"zfs_no_scrub_prefetch",
322 		"zfs_vdev_aggregation_limit",
323 		"fzap_default_block_shift",
324 		"zfs_immediate_write_sz",
325 		"zfs_read_chunk_size",
326 		"zfs_nocacheflush",
327 		"zil_replay_disable",
328 		"metaslab_gang_bang",
329 		"metaslab_df_alloc_threshold",
330 		"metaslab_df_free_pct",
331 		"zio_injection_enabled",
332 		"zvol_immediate_write_sz",
333 	};
334 
335 	for (int i = 0; i < sizeof (params) / sizeof (params[0]); i++) {
336 		int sz;
337 		uint64_t val64;
338 		uint32_t *val32p = (uint32_t *)&val64;
339 
340 		sz = mdb_readvar(&val64, params[i]);
341 		if (sz == 4) {
342 			mdb_printf("%s = 0x%x\n", params[i], *val32p);
343 		} else if (sz == 8) {
344 			mdb_printf("%s = 0x%llx\n", params[i], val64);
345 		} else {
346 			mdb_warn("variable %s not found", params[i]);
347 		}
348 	}
349 
350 	return (DCMD_OK);
351 }
352 
353 /* ARGSUSED */
354 static int
355 blkptr(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
356 {
357 	mdb_ctf_id_t type_enum, checksum_enum, compress_enum;
358 	char type[80], checksum[80], compress[80];
359 	blkptr_t blk, *bp = &blk;
360 	char buf[BP_SPRINTF_LEN];
361 
362 	if (mdb_vread(&blk, sizeof (blkptr_t), addr) == -1) {
363 		mdb_warn("failed to read blkptr_t");
364 		return (DCMD_ERR);
365 	}
366 
367 	if (mdb_ctf_lookup_by_name("enum dmu_object_type", &type_enum) == -1 ||
368 	    mdb_ctf_lookup_by_name("enum zio_checksum", &checksum_enum) == -1 ||
369 	    mdb_ctf_lookup_by_name("enum zio_compress", &compress_enum) == -1) {
370 		mdb_warn("Could not find blkptr enumerated types");
371 		return (DCMD_ERR);
372 	}
373 
374 	enum_lookup(type, sizeof (type), type_enum,
375 	    BP_GET_TYPE(bp), "DMU_OT_");
376 	enum_lookup(checksum, sizeof (checksum), checksum_enum,
377 	    BP_GET_CHECKSUM(bp), "ZIO_CHECKSUM_");
378 	enum_lookup(compress, sizeof (compress), compress_enum,
379 	    BP_GET_COMPRESS(bp), "ZIO_COMPRESS_");
380 
381 	SPRINTF_BLKPTR(mdb_snprintf, '\n', buf, bp, type, checksum, compress);
382 
383 	mdb_printf("%s\n", buf);
384 
385 	return (DCMD_OK);
386 }
387 
388 typedef struct mdb_dmu_buf_impl {
389 	struct {
390 		uint64_t db_object;
391 	} db;
392 	uintptr_t db_objset;
393 	uint64_t db_level;
394 	uint64_t db_blkid;
395 	struct {
396 		uint64_t rc_count;
397 	} db_holds;
398 } mdb_dmu_buf_impl_t;
399 
400 /* ARGSUSED */
401 static int
402 dbuf(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
403 {
404 	mdb_dmu_buf_impl_t db;
405 	char objectname[32];
406 	char blkidname[32];
407 	char path[MAXNAMELEN];
408 
409 	if (DCMD_HDRSPEC(flags))
410 		mdb_printf("        addr object lvl blkid holds os\n");
411 
412 	if (mdb_ctf_vread(&db, ZFS_STRUCT "dmu_buf_impl", "mdb_dmu_buf_impl_t",
413 	    addr, 0) == -1)
414 		return (DCMD_ERR);
415 
416 	if (db.db.db_object == DMU_META_DNODE_OBJECT)
417 		(void) strcpy(objectname, "mdn");
418 	else
419 		(void) mdb_snprintf(objectname, sizeof (objectname), "%llx",
420 		    (u_longlong_t)db.db.db_object);
421 
422 	if (db.db_blkid == DMU_BONUS_BLKID)
423 		(void) strcpy(blkidname, "bonus");
424 	else
425 		(void) mdb_snprintf(blkidname, sizeof (blkidname), "%llx",
426 		    (u_longlong_t)db.db_blkid);
427 
428 	if (objset_name(db.db_objset, path)) {
429 		return (DCMD_ERR);
430 	}
431 
432 	mdb_printf("%p %8s %1u %9s %2llu %s\n", addr,
433 	    objectname, (int)db.db_level, blkidname,
434 	    db.db_holds.rc_count, path);
435 
436 	return (DCMD_OK);
437 }
438 
439 /* ARGSUSED */
440 static int
441 dbuf_stats(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
442 {
443 #define	HISTOSZ 32
444 	uintptr_t dbp;
445 	dmu_buf_impl_t db;
446 	dbuf_hash_table_t ht;
447 	uint64_t bucket, ndbufs;
448 	uint64_t histo[HISTOSZ];
449 	uint64_t histo2[HISTOSZ];
450 	int i, maxidx;
451 
452 	if (mdb_readvar(&ht, "dbuf_hash_table") == -1) {
453 		mdb_warn("failed to read 'dbuf_hash_table'");
454 		return (DCMD_ERR);
455 	}
456 
457 	for (i = 0; i < HISTOSZ; i++) {
458 		histo[i] = 0;
459 		histo2[i] = 0;
460 	}
461 
462 	ndbufs = 0;
463 	for (bucket = 0; bucket < ht.hash_table_mask+1; bucket++) {
464 		int len;
465 
466 		if (mdb_vread(&dbp, sizeof (void *),
467 		    (uintptr_t)(ht.hash_table+bucket)) == -1) {
468 			mdb_warn("failed to read hash bucket %u at %p",
469 			    bucket, ht.hash_table+bucket);
470 			return (DCMD_ERR);
471 		}
472 
473 		len = 0;
474 		while (dbp != 0) {
475 			if (mdb_vread(&db, sizeof (dmu_buf_impl_t),
476 			    dbp) == -1) {
477 				mdb_warn("failed to read dbuf at %p", dbp);
478 				return (DCMD_ERR);
479 			}
480 			dbp = (uintptr_t)db.db_hash_next;
481 			for (i = MIN(len, HISTOSZ - 1); i >= 0; i--)
482 				histo2[i]++;
483 			len++;
484 			ndbufs++;
485 		}
486 
487 		if (len >= HISTOSZ)
488 			len = HISTOSZ-1;
489 		histo[len]++;
490 	}
491 
492 	mdb_printf("hash table has %llu buckets, %llu dbufs "
493 	    "(avg %llu buckets/dbuf)\n",
494 	    ht.hash_table_mask+1, ndbufs,
495 	    (ht.hash_table_mask+1)/ndbufs);
496 
497 	mdb_printf("\n");
498 	maxidx = 0;
499 	for (i = 0; i < HISTOSZ; i++)
500 		if (histo[i] > 0)
501 			maxidx = i;
502 	mdb_printf("hash chain length	number of buckets\n");
503 	for (i = 0; i <= maxidx; i++)
504 		mdb_printf("%u			%llu\n", i, histo[i]);
505 
506 	mdb_printf("\n");
507 	maxidx = 0;
508 	for (i = 0; i < HISTOSZ; i++)
509 		if (histo2[i] > 0)
510 			maxidx = i;
511 	mdb_printf("hash chain depth	number of dbufs\n");
512 	for (i = 0; i <= maxidx; i++)
513 		mdb_printf("%u or more		%llu	%llu%%\n",
514 		    i, histo2[i], histo2[i]*100/ndbufs);
515 
516 
517 	return (DCMD_OK);
518 }
519 
520 #define	CHAIN_END 0xffff
521 /*
522  * ::zap_leaf [-v]
523  *
524  * Print a zap_leaf_phys_t, assumed to be 16k
525  */
526 /* ARGSUSED */
527 static int
528 zap_leaf(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
529 {
530 	char buf[16*1024];
531 	int verbose = B_FALSE;
532 	int four = B_FALSE;
533 	zap_leaf_t l;
534 	zap_leaf_phys_t *zlp = (void *)buf;
535 	int i;
536 
537 	if (mdb_getopts(argc, argv,
538 	    'v', MDB_OPT_SETBITS, TRUE, &verbose,
539 	    '4', MDB_OPT_SETBITS, TRUE, &four,
540 	    NULL) != argc)
541 		return (DCMD_USAGE);
542 
543 	l.l_phys = zlp;
544 	l.l_bs = 14; /* assume 16k blocks */
545 	if (four)
546 		l.l_bs = 12;
547 
548 	if (!(flags & DCMD_ADDRSPEC)) {
549 		return (DCMD_USAGE);
550 	}
551 
552 	if (mdb_vread(buf, sizeof (buf), addr) == -1) {
553 		mdb_warn("failed to read zap_leaf_phys_t at %p", addr);
554 		return (DCMD_ERR);
555 	}
556 
557 	if (zlp->l_hdr.lh_block_type != ZBT_LEAF ||
558 	    zlp->l_hdr.lh_magic != ZAP_LEAF_MAGIC) {
559 		mdb_warn("This does not appear to be a zap_leaf_phys_t");
560 		return (DCMD_ERR);
561 	}
562 
563 	mdb_printf("zap_leaf_phys_t at %p:\n", addr);
564 	mdb_printf("    lh_prefix_len = %u\n", zlp->l_hdr.lh_prefix_len);
565 	mdb_printf("    lh_prefix = %llx\n", zlp->l_hdr.lh_prefix);
566 	mdb_printf("    lh_nentries = %u\n", zlp->l_hdr.lh_nentries);
567 	mdb_printf("    lh_nfree = %u\n", zlp->l_hdr.lh_nfree,
568 	    zlp->l_hdr.lh_nfree * 100 / (ZAP_LEAF_NUMCHUNKS(&l)));
569 	mdb_printf("    lh_freelist = %u\n", zlp->l_hdr.lh_freelist);
570 	mdb_printf("    lh_flags = %x (%s)\n", zlp->l_hdr.lh_flags,
571 	    zlp->l_hdr.lh_flags & ZLF_ENTRIES_CDSORTED ?
572 	    "ENTRIES_CDSORTED" : "");
573 
574 	if (verbose) {
575 		mdb_printf(" hash table:\n");
576 		for (i = 0; i < ZAP_LEAF_HASH_NUMENTRIES(&l); i++) {
577 			if (zlp->l_hash[i] != CHAIN_END)
578 				mdb_printf("    %u: %u\n", i, zlp->l_hash[i]);
579 		}
580 	}
581 
582 	mdb_printf(" chunks:\n");
583 	for (i = 0; i < ZAP_LEAF_NUMCHUNKS(&l); i++) {
584 		/* LINTED: alignment */
585 		zap_leaf_chunk_t *zlc = &ZAP_LEAF_CHUNK(&l, i);
586 		switch (zlc->l_entry.le_type) {
587 		case ZAP_CHUNK_FREE:
588 			if (verbose) {
589 				mdb_printf("    %u: free; lf_next = %u\n",
590 				    i, zlc->l_free.lf_next);
591 			}
592 			break;
593 		case ZAP_CHUNK_ENTRY:
594 			mdb_printf("    %u: entry\n", i);
595 			if (verbose) {
596 				mdb_printf("        le_next = %u\n",
597 				    zlc->l_entry.le_next);
598 			}
599 			mdb_printf("        le_name_chunk = %u\n",
600 			    zlc->l_entry.le_name_chunk);
601 			mdb_printf("        le_name_numints = %u\n",
602 			    zlc->l_entry.le_name_numints);
603 			mdb_printf("        le_value_chunk = %u\n",
604 			    zlc->l_entry.le_value_chunk);
605 			mdb_printf("        le_value_intlen = %u\n",
606 			    zlc->l_entry.le_value_intlen);
607 			mdb_printf("        le_value_numints = %u\n",
608 			    zlc->l_entry.le_value_numints);
609 			mdb_printf("        le_cd = %u\n",
610 			    zlc->l_entry.le_cd);
611 			mdb_printf("        le_hash = %llx\n",
612 			    zlc->l_entry.le_hash);
613 			break;
614 		case ZAP_CHUNK_ARRAY:
615 			mdb_printf("    %u: array", i);
616 			if (strisprint((char *)zlc->l_array.la_array))
617 				mdb_printf(" \"%s\"", zlc->l_array.la_array);
618 			mdb_printf("\n");
619 			if (verbose) {
620 				int j;
621 				mdb_printf("        ");
622 				for (j = 0; j < ZAP_LEAF_ARRAY_BYTES; j++) {
623 					mdb_printf("%02x ",
624 					    zlc->l_array.la_array[j]);
625 				}
626 				mdb_printf("\n");
627 			}
628 			if (zlc->l_array.la_next != CHAIN_END) {
629 				mdb_printf("        lf_next = %u\n",
630 				    zlc->l_array.la_next);
631 			}
632 			break;
633 		default:
634 			mdb_printf("    %u: undefined type %u\n",
635 			    zlc->l_entry.le_type);
636 		}
637 	}
638 
639 	return (DCMD_OK);
640 }
641 
642 typedef struct dbufs_data {
643 	mdb_ctf_id_t id;
644 	uint64_t objset;
645 	uint64_t object;
646 	uint64_t level;
647 	uint64_t blkid;
648 	char *osname;
649 } dbufs_data_t;
650 
651 #define	DBUFS_UNSET	(0xbaddcafedeadbeefULL)
652 
653 /* ARGSUSED */
654 static int
655 dbufs_cb(uintptr_t addr, const void *unknown, void *arg)
656 {
657 	dbufs_data_t *data = arg;
658 	uintptr_t objset;
659 	dmu_buf_t db;
660 	uint8_t level;
661 	uint64_t blkid;
662 	char osname[MAXNAMELEN];
663 
664 	if (GETMEMBID(addr, &data->id, db_objset, objset) ||
665 	    GETMEMBID(addr, &data->id, db, db) ||
666 	    GETMEMBID(addr, &data->id, db_level, level) ||
667 	    GETMEMBID(addr, &data->id, db_blkid, blkid)) {
668 		return (WALK_ERR);
669 	}
670 
671 	if ((data->objset == DBUFS_UNSET || data->objset == objset) &&
672 	    (data->osname == NULL || (objset_name(objset, osname) == 0 &&
673 	    strcmp(data->osname, osname) == 0)) &&
674 	    (data->object == DBUFS_UNSET || data->object == db.db_object) &&
675 	    (data->level == DBUFS_UNSET || data->level == level) &&
676 	    (data->blkid == DBUFS_UNSET || data->blkid == blkid)) {
677 		mdb_printf("%#lr\n", addr);
678 	}
679 	return (WALK_NEXT);
680 }
681 
682 /* ARGSUSED */
683 static int
684 dbufs(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
685 {
686 	dbufs_data_t data;
687 	char *object = NULL;
688 	char *blkid = NULL;
689 
690 	data.objset = data.object = data.level = data.blkid = DBUFS_UNSET;
691 	data.osname = NULL;
692 
693 	if (mdb_getopts(argc, argv,
694 	    'O', MDB_OPT_UINT64, &data.objset,
695 	    'n', MDB_OPT_STR, &data.osname,
696 	    'o', MDB_OPT_STR, &object,
697 	    'l', MDB_OPT_UINT64, &data.level,
698 	    'b', MDB_OPT_STR, &blkid) != argc) {
699 		return (DCMD_USAGE);
700 	}
701 
702 	if (object) {
703 		if (strcmp(object, "mdn") == 0) {
704 			data.object = DMU_META_DNODE_OBJECT;
705 		} else {
706 			data.object = mdb_strtoull(object);
707 		}
708 	}
709 
710 	if (blkid) {
711 		if (strcmp(blkid, "bonus") == 0) {
712 			data.blkid = DMU_BONUS_BLKID;
713 		} else {
714 			data.blkid = mdb_strtoull(blkid);
715 		}
716 	}
717 
718 	if (mdb_ctf_lookup_by_name(ZFS_STRUCT "dmu_buf_impl", &data.id) == -1) {
719 		mdb_warn("couldn't find struct dmu_buf_impl_t");
720 		return (DCMD_ERR);
721 	}
722 
723 	if (mdb_walk("dmu_buf_impl_t", dbufs_cb, &data) != 0) {
724 		mdb_warn("can't walk dbufs");
725 		return (DCMD_ERR);
726 	}
727 
728 	return (DCMD_OK);
729 }
730 
731 typedef struct abuf_find_data {
732 	dva_t dva;
733 	mdb_ctf_id_t id;
734 } abuf_find_data_t;
735 
736 /* ARGSUSED */
737 static int
738 abuf_find_cb(uintptr_t addr, const void *unknown, void *arg)
739 {
740 	abuf_find_data_t *data = arg;
741 	dva_t dva;
742 
743 	if (GETMEMBID(addr, &data->id, b_dva, dva)) {
744 		return (WALK_ERR);
745 	}
746 
747 	if (dva.dva_word[0] == data->dva.dva_word[0] &&
748 	    dva.dva_word[1] == data->dva.dva_word[1]) {
749 		mdb_printf("%#lr\n", addr);
750 	}
751 	return (WALK_NEXT);
752 }
753 
754 /* ARGSUSED */
755 static int
756 abuf_find(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
757 {
758 	abuf_find_data_t data;
759 	GElf_Sym sym;
760 	int i;
761 	const char *syms[] = {
762 		"ARC_mru",
763 		"ARC_mru_ghost",
764 		"ARC_mfu",
765 		"ARC_mfu_ghost",
766 	};
767 
768 	if (argc != 2)
769 		return (DCMD_USAGE);
770 
771 	for (i = 0; i < 2; i ++) {
772 		switch (argv[i].a_type) {
773 		case MDB_TYPE_STRING:
774 			data.dva.dva_word[i] = mdb_strtoull(argv[i].a_un.a_str);
775 			break;
776 		case MDB_TYPE_IMMEDIATE:
777 			data.dva.dva_word[i] = argv[i].a_un.a_val;
778 			break;
779 		default:
780 			return (DCMD_USAGE);
781 		}
782 	}
783 
784 	if (mdb_ctf_lookup_by_name(ZFS_STRUCT "arc_buf_hdr", &data.id) == -1) {
785 		mdb_warn("couldn't find struct arc_buf_hdr");
786 		return (DCMD_ERR);
787 	}
788 
789 	for (i = 0; i < sizeof (syms) / sizeof (syms[0]); i++) {
790 		if (mdb_lookup_by_obj(ZFS_OBJ_NAME, syms[i], &sym)) {
791 			mdb_warn("can't find symbol %s", syms[i]);
792 			return (DCMD_ERR);
793 		}
794 
795 		if (mdb_pwalk("list", abuf_find_cb, &data, sym.st_value) != 0) {
796 			mdb_warn("can't walk %s", syms[i]);
797 			return (DCMD_ERR);
798 		}
799 	}
800 
801 	return (DCMD_OK);
802 }
803 
804 
805 typedef struct dbgmsg_arg {
806 	boolean_t da_verbose;
807 	boolean_t da_address;
808 } dbgmsg_arg_t;
809 
810 /* ARGSUSED */
811 static int
812 dbgmsg_cb(uintptr_t addr, const void *unknown, void *arg)
813 {
814 	static mdb_ctf_id_t id;
815 	static boolean_t gotid;
816 	static ulong_t off;
817 
818 	dbgmsg_arg_t *da = arg;
819 	time_t timestamp;
820 	char buf[1024];
821 
822 	if (!gotid) {
823 		if (mdb_ctf_lookup_by_name(ZFS_STRUCT "zfs_dbgmsg", &id) ==
824 		    -1) {
825 			mdb_warn("couldn't find struct zfs_dbgmsg");
826 			return (WALK_ERR);
827 		}
828 		gotid = TRUE;
829 		if (mdb_ctf_offsetof(id, "zdm_msg", &off) == -1) {
830 			mdb_warn("couldn't find zdm_msg");
831 			return (WALK_ERR);
832 		}
833 		off /= 8;
834 	}
835 
836 
837 	if (GETMEMBID(addr, &id, zdm_timestamp, timestamp)) {
838 		return (WALK_ERR);
839 	}
840 
841 	if (mdb_readstr(buf, sizeof (buf), addr + off) == -1) {
842 		mdb_warn("failed to read zdm_msg at %p\n", addr + off);
843 		return (DCMD_ERR);
844 	}
845 
846 	if (da->da_address)
847 		mdb_printf("%p ", addr);
848 	if (da->da_verbose)
849 		mdb_printf("%Y ", timestamp);
850 
851 	mdb_printf("%s\n", buf);
852 
853 	if (da->da_verbose)
854 		(void) mdb_call_dcmd("whatis", addr, DCMD_ADDRSPEC, 0, NULL);
855 
856 	return (WALK_NEXT);
857 }
858 
859 /* ARGSUSED */
860 static int
861 dbgmsg(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
862 {
863 	GElf_Sym sym;
864 	dbgmsg_arg_t da = { 0 };
865 
866 	if (mdb_getopts(argc, argv,
867 	    'v', MDB_OPT_SETBITS, B_TRUE, &da.da_verbose,
868 	    'a', MDB_OPT_SETBITS, B_TRUE, &da.da_address,
869 	    NULL) != argc)
870 		return (DCMD_USAGE);
871 
872 	if (mdb_lookup_by_obj(ZFS_OBJ_NAME, "zfs_dbgmsgs", &sym)) {
873 		mdb_warn("can't find zfs_dbgmsgs");
874 		return (DCMD_ERR);
875 	}
876 
877 	if (mdb_pwalk("list", dbgmsg_cb, &da, sym.st_value) != 0) {
878 		mdb_warn("can't walk zfs_dbgmsgs");
879 		return (DCMD_ERR);
880 	}
881 
882 	return (DCMD_OK);
883 }
884 
885 /*ARGSUSED*/
886 static int
887 arc_print(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
888 {
889 	kstat_named_t *stats;
890 	GElf_Sym sym;
891 	int nstats, i;
892 	uint_t opt_a = FALSE;
893 	uint_t opt_b = FALSE;
894 	uint_t shift = 0;
895 	const char *suffix;
896 
897 	static const char *bytestats[] = {
898 		"p", "c", "c_min", "c_max", "size", "duplicate_buffers_size",
899 		"arc_meta_used", "arc_meta_limit", "arc_meta_max",
900 		NULL
901 	};
902 
903 	static const char *extras[] = {
904 		"arc_no_grow", "arc_tempreserve",
905 		NULL
906 	};
907 
908 	if (mdb_lookup_by_obj(ZFS_OBJ_NAME, "arc_stats", &sym) == -1) {
909 		mdb_warn("failed to find 'arc_stats'");
910 		return (DCMD_ERR);
911 	}
912 
913 	stats = mdb_zalloc(sym.st_size, UM_SLEEP | UM_GC);
914 
915 	if (mdb_vread(stats, sym.st_size, sym.st_value) == -1) {
916 		mdb_warn("couldn't read 'arc_stats' at %p", sym.st_value);
917 		return (DCMD_ERR);
918 	}
919 
920 	nstats = sym.st_size / sizeof (kstat_named_t);
921 
922 	/* NB: -a / opt_a are ignored for backwards compatability */
923 	if (mdb_getopts(argc, argv,
924 	    'a', MDB_OPT_SETBITS, TRUE, &opt_a,
925 	    'b', MDB_OPT_SETBITS, TRUE, &opt_b,
926 	    'k', MDB_OPT_SETBITS, 10, &shift,
927 	    'm', MDB_OPT_SETBITS, 20, &shift,
928 	    'g', MDB_OPT_SETBITS, 30, &shift,
929 	    NULL) != argc)
930 		return (DCMD_USAGE);
931 
932 	if (!opt_b && !shift)
933 		shift = 20;
934 
935 	switch (shift) {
936 	case 0:
937 		suffix = "B";
938 		break;
939 	case 10:
940 		suffix = "KB";
941 		break;
942 	case 20:
943 		suffix = "MB";
944 		break;
945 	case 30:
946 		suffix = "GB";
947 		break;
948 	default:
949 		suffix = "XX";
950 	}
951 
952 	for (i = 0; i < nstats; i++) {
953 		int j;
954 		boolean_t bytes = B_FALSE;
955 
956 		for (j = 0; bytestats[j]; j++) {
957 			if (strcmp(stats[i].name, bytestats[j]) == 0) {
958 				bytes = B_TRUE;
959 				break;
960 			}
961 		}
962 
963 		if (bytes) {
964 			mdb_printf("%-25s = %9llu %s\n", stats[i].name,
965 			    stats[i].value.ui64 >> shift, suffix);
966 		} else {
967 			mdb_printf("%-25s = %9llu\n", stats[i].name,
968 			    stats[i].value.ui64);
969 		}
970 	}
971 
972 	for (i = 0; extras[i]; i++) {
973 		uint64_t buf;
974 
975 		if (mdb_lookup_by_obj(ZFS_OBJ_NAME, extras[i], &sym) == -1) {
976 			mdb_warn("failed to find '%s'", extras[i]);
977 			return (DCMD_ERR);
978 		}
979 
980 		if (sym.st_size != sizeof (uint64_t) &&
981 		    sym.st_size != sizeof (uint32_t)) {
982 			mdb_warn("expected scalar for variable '%s'\n",
983 			    extras[i]);
984 			return (DCMD_ERR);
985 		}
986 
987 		if (mdb_vread(&buf, sym.st_size, sym.st_value) == -1) {
988 			mdb_warn("couldn't read '%s'", extras[i]);
989 			return (DCMD_ERR);
990 		}
991 
992 		mdb_printf("%-25s = ", extras[i]);
993 
994 		/* NB: all the 64-bit extras happen to be byte counts */
995 		if (sym.st_size == sizeof (uint64_t))
996 			mdb_printf("%9llu %s\n", buf >> shift, suffix);
997 
998 		if (sym.st_size == sizeof (uint32_t))
999 			mdb_printf("%9d\n", *((uint32_t *)&buf));
1000 	}
1001 	return (DCMD_OK);
1002 }
1003 
1004 typedef struct mdb_spa_print {
1005 	pool_state_t spa_state;
1006 	char spa_name[MAXNAMELEN];
1007 } mdb_spa_print_t;
1008 
1009 /*
1010  * ::spa
1011  *
1012  *	-c	Print configuration information as well
1013  *	-v	Print vdev state
1014  *	-e	Print vdev error stats
1015  *
1016  * Print a summarized spa_t.  When given no arguments, prints out a table of all
1017  * active pools on the system.
1018  */
1019 /* ARGSUSED */
1020 static int
1021 spa_print(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
1022 {
1023 	const char *statetab[] = { "ACTIVE", "EXPORTED", "DESTROYED",
1024 		"SPARE", "L2CACHE", "UNINIT", "UNAVAIL", "POTENTIAL" };
1025 	const char *state;
1026 	int config = FALSE;
1027 	int vdevs = FALSE;
1028 	int errors = FALSE;
1029 
1030 	if (mdb_getopts(argc, argv,
1031 	    'c', MDB_OPT_SETBITS, TRUE, &config,
1032 	    'v', MDB_OPT_SETBITS, TRUE, &vdevs,
1033 	    'e', MDB_OPT_SETBITS, TRUE, &errors,
1034 	    NULL) != argc)
1035 		return (DCMD_USAGE);
1036 
1037 	if (!(flags & DCMD_ADDRSPEC)) {
1038 		if (mdb_walk_dcmd("spa", "spa", argc, argv) == -1) {
1039 			mdb_warn("can't walk spa");
1040 			return (DCMD_ERR);
1041 		}
1042 
1043 		return (DCMD_OK);
1044 	}
1045 
1046 	if (flags & DCMD_PIPE_OUT) {
1047 		mdb_printf("%#lr\n", addr);
1048 		return (DCMD_OK);
1049 	}
1050 
1051 	if (DCMD_HDRSPEC(flags))
1052 		mdb_printf("%<u>%-?s %9s %-*s%</u>\n", "ADDR", "STATE",
1053 		    sizeof (uintptr_t) == 4 ? 60 : 52, "NAME");
1054 
1055 	mdb_spa_print_t spa;
1056 	if (mdb_ctf_vread(&spa, "spa_t", "mdb_spa_print_t", addr, 0) == -1)
1057 		return (DCMD_ERR);
1058 
1059 	if (spa.spa_state < 0 || spa.spa_state > POOL_STATE_UNAVAIL)
1060 		state = "UNKNOWN";
1061 	else
1062 		state = statetab[spa.spa_state];
1063 
1064 	mdb_printf("%0?p %9s %s\n", addr, state, spa.spa_name);
1065 
1066 	if (config) {
1067 		mdb_printf("\n");
1068 		mdb_inc_indent(4);
1069 		if (mdb_call_dcmd("spa_config", addr, flags, 0,
1070 		    NULL) != DCMD_OK)
1071 			return (DCMD_ERR);
1072 		mdb_dec_indent(4);
1073 	}
1074 
1075 	if (vdevs || errors) {
1076 		mdb_arg_t v;
1077 
1078 		v.a_type = MDB_TYPE_STRING;
1079 		v.a_un.a_str = "-e";
1080 
1081 		mdb_printf("\n");
1082 		mdb_inc_indent(4);
1083 		if (mdb_call_dcmd("spa_vdevs", addr, flags, errors ? 1 : 0,
1084 		    &v) != DCMD_OK)
1085 			return (DCMD_ERR);
1086 		mdb_dec_indent(4);
1087 	}
1088 
1089 	return (DCMD_OK);
1090 }
1091 
1092 typedef struct mdb_spa_config_spa {
1093 	uintptr_t spa_config;
1094 } mdb_spa_config_spa_t;
1095 
1096 /*
1097  * ::spa_config
1098  *
1099  * Given a spa_t, print the configuration information stored in spa_config.
1100  * Since it's just an nvlist, format it as an indented list of name=value pairs.
1101  * We simply read the value of spa_config and pass off to ::nvlist.
1102  */
1103 /* ARGSUSED */
1104 static int
1105 spa_print_config(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
1106 {
1107 	mdb_spa_config_spa_t spa;
1108 
1109 	if (argc != 0 || !(flags & DCMD_ADDRSPEC))
1110 		return (DCMD_USAGE);
1111 
1112 	if (mdb_ctf_vread(&spa, ZFS_STRUCT "spa", "mdb_spa_config_spa_t",
1113 	    addr, 0) == -1)
1114 		return (DCMD_ERR);
1115 
1116 	if (spa.spa_config == 0) {
1117 		mdb_printf("(none)\n");
1118 		return (DCMD_OK);
1119 	}
1120 
1121 	return (mdb_call_dcmd("nvlist", spa.spa_config, flags,
1122 	    0, NULL));
1123 }
1124 
1125 /*
1126  * ::vdev
1127  *
1128  * Print out a summarized vdev_t, in the following form:
1129  *
1130  * ADDR             STATE	AUX            DESC
1131  * fffffffbcde23df0 HEALTHY	-              /dev/dsk/c0t0d0
1132  *
1133  * If '-r' is specified, recursively visit all children.
1134  *
1135  * With '-e', the statistics associated with the vdev are printed as well.
1136  */
1137 static int
1138 do_print_vdev(uintptr_t addr, int flags, int depth, int stats,
1139     int recursive)
1140 {
1141 	vdev_t vdev;
1142 	char desc[MAXNAMELEN];
1143 	int c, children;
1144 	uintptr_t *child;
1145 	const char *state, *aux;
1146 
1147 	if (mdb_vread(&vdev, sizeof (vdev), (uintptr_t)addr) == -1) {
1148 		mdb_warn("failed to read vdev_t at %p\n", (uintptr_t)addr);
1149 		return (DCMD_ERR);
1150 	}
1151 
1152 	if (flags & DCMD_PIPE_OUT) {
1153 		mdb_printf("%#lr\n", addr);
1154 	} else {
1155 		if (vdev.vdev_path != NULL) {
1156 			if (mdb_readstr(desc, sizeof (desc),
1157 			    (uintptr_t)vdev.vdev_path) == -1) {
1158 				mdb_warn("failed to read vdev_path at %p\n",
1159 				    vdev.vdev_path);
1160 				return (DCMD_ERR);
1161 			}
1162 		} else if (vdev.vdev_ops != NULL) {
1163 			vdev_ops_t ops;
1164 			if (mdb_vread(&ops, sizeof (ops),
1165 			    (uintptr_t)vdev.vdev_ops) == -1) {
1166 				mdb_warn("failed to read vdev_ops at %p\n",
1167 				    vdev.vdev_ops);
1168 				return (DCMD_ERR);
1169 			}
1170 			(void) strcpy(desc, ops.vdev_op_type);
1171 		} else {
1172 			(void) strcpy(desc, "<unknown>");
1173 		}
1174 
1175 		if (depth == 0 && DCMD_HDRSPEC(flags))
1176 			mdb_printf("%<u>%-?s %-9s %-12s %-*s%</u>\n",
1177 			    "ADDR", "STATE", "AUX",
1178 			    sizeof (uintptr_t) == 4 ? 43 : 35,
1179 			    "DESCRIPTION");
1180 
1181 		mdb_printf("%0?p ", addr);
1182 
1183 		switch (vdev.vdev_state) {
1184 		case VDEV_STATE_CLOSED:
1185 			state = "CLOSED";
1186 			break;
1187 		case VDEV_STATE_OFFLINE:
1188 			state = "OFFLINE";
1189 			break;
1190 		case VDEV_STATE_CANT_OPEN:
1191 			state = "CANT_OPEN";
1192 			break;
1193 		case VDEV_STATE_DEGRADED:
1194 			state = "DEGRADED";
1195 			break;
1196 		case VDEV_STATE_HEALTHY:
1197 			state = "HEALTHY";
1198 			break;
1199 		case VDEV_STATE_REMOVED:
1200 			state = "REMOVED";
1201 			break;
1202 		case VDEV_STATE_FAULTED:
1203 			state = "FAULTED";
1204 			break;
1205 		default:
1206 			state = "UNKNOWN";
1207 			break;
1208 		}
1209 
1210 		switch (vdev.vdev_stat.vs_aux) {
1211 		case VDEV_AUX_NONE:
1212 			aux = "-";
1213 			break;
1214 		case VDEV_AUX_OPEN_FAILED:
1215 			aux = "OPEN_FAILED";
1216 			break;
1217 		case VDEV_AUX_CORRUPT_DATA:
1218 			aux = "CORRUPT_DATA";
1219 			break;
1220 		case VDEV_AUX_NO_REPLICAS:
1221 			aux = "NO_REPLICAS";
1222 			break;
1223 		case VDEV_AUX_BAD_GUID_SUM:
1224 			aux = "BAD_GUID_SUM";
1225 			break;
1226 		case VDEV_AUX_TOO_SMALL:
1227 			aux = "TOO_SMALL";
1228 			break;
1229 		case VDEV_AUX_BAD_LABEL:
1230 			aux = "BAD_LABEL";
1231 			break;
1232 		case VDEV_AUX_VERSION_NEWER:
1233 			aux = "VERS_NEWER";
1234 			break;
1235 		case VDEV_AUX_VERSION_OLDER:
1236 			aux = "VERS_OLDER";
1237 			break;
1238 		case VDEV_AUX_UNSUP_FEAT:
1239 			aux = "UNSUP_FEAT";
1240 			break;
1241 		case VDEV_AUX_SPARED:
1242 			aux = "SPARED";
1243 			break;
1244 		case VDEV_AUX_ERR_EXCEEDED:
1245 			aux = "ERR_EXCEEDED";
1246 			break;
1247 		case VDEV_AUX_IO_FAILURE:
1248 			aux = "IO_FAILURE";
1249 			break;
1250 		case VDEV_AUX_BAD_LOG:
1251 			aux = "BAD_LOG";
1252 			break;
1253 		case VDEV_AUX_EXTERNAL:
1254 			aux = "EXTERNAL";
1255 			break;
1256 		case VDEV_AUX_SPLIT_POOL:
1257 			aux = "SPLIT_POOL";
1258 			break;
1259 		default:
1260 			aux = "UNKNOWN";
1261 			break;
1262 		}
1263 
1264 		mdb_printf("%-9s %-12s %*s%s\n", state, aux, depth, "", desc);
1265 
1266 		if (stats) {
1267 			vdev_stat_t *vs = &vdev.vdev_stat;
1268 			int i;
1269 
1270 			mdb_inc_indent(4);
1271 			mdb_printf("\n");
1272 			mdb_printf("%<u>       %12s %12s %12s %12s "
1273 			    "%12s%</u>\n", "READ", "WRITE", "FREE", "CLAIM",
1274 			    "IOCTL");
1275 			mdb_printf("OPS     ");
1276 			for (i = 1; i < ZIO_TYPES; i++)
1277 				mdb_printf("%11#llx%s", vs->vs_ops[i],
1278 				    i == ZIO_TYPES - 1 ? "" : "  ");
1279 			mdb_printf("\n");
1280 			mdb_printf("BYTES   ");
1281 			for (i = 1; i < ZIO_TYPES; i++)
1282 				mdb_printf("%11#llx%s", vs->vs_bytes[i],
1283 				    i == ZIO_TYPES - 1 ? "" : "  ");
1284 
1285 
1286 			mdb_printf("\n");
1287 			mdb_printf("EREAD    %10#llx\n", vs->vs_read_errors);
1288 			mdb_printf("EWRITE   %10#llx\n", vs->vs_write_errors);
1289 			mdb_printf("ECKSUM   %10#llx\n",
1290 			    vs->vs_checksum_errors);
1291 			mdb_dec_indent(4);
1292 		}
1293 
1294 		if (stats)
1295 			mdb_printf("\n");
1296 	}
1297 
1298 	children = vdev.vdev_children;
1299 
1300 	if (children == 0 || !recursive)
1301 		return (DCMD_OK);
1302 
1303 	child = mdb_alloc(children * sizeof (void *), UM_SLEEP | UM_GC);
1304 	if (mdb_vread(child, children * sizeof (void *),
1305 	    (uintptr_t)vdev.vdev_child) == -1) {
1306 		mdb_warn("failed to read vdev children at %p", vdev.vdev_child);
1307 		return (DCMD_ERR);
1308 	}
1309 
1310 	for (c = 0; c < children; c++) {
1311 		if (do_print_vdev(child[c], flags, depth + 2, stats,
1312 		    recursive))
1313 			return (DCMD_ERR);
1314 	}
1315 
1316 	return (DCMD_OK);
1317 }
1318 
1319 static int
1320 vdev_print(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
1321 {
1322 	int recursive = FALSE;
1323 	int stats = FALSE;
1324 	uint64_t depth = 0;
1325 
1326 	if (mdb_getopts(argc, argv,
1327 	    'r', MDB_OPT_SETBITS, TRUE, &recursive,
1328 	    'e', MDB_OPT_SETBITS, TRUE, &stats,
1329 	    'd', MDB_OPT_UINT64, &depth,
1330 	    NULL) != argc)
1331 		return (DCMD_USAGE);
1332 
1333 	if (!(flags & DCMD_ADDRSPEC)) {
1334 		mdb_warn("no vdev_t address given\n");
1335 		return (DCMD_ERR);
1336 	}
1337 
1338 	return (do_print_vdev(addr, flags, (int)depth, stats, recursive));
1339 }
1340 
1341 typedef struct metaslab_walk_data {
1342 	uint64_t mw_numvdevs;
1343 	uintptr_t *mw_vdevs;
1344 	int mw_curvdev;
1345 	uint64_t mw_nummss;
1346 	uintptr_t *mw_mss;
1347 	int mw_curms;
1348 } metaslab_walk_data_t;
1349 
1350 static int
1351 metaslab_walk_step(mdb_walk_state_t *wsp)
1352 {
1353 	metaslab_walk_data_t *mw = wsp->walk_data;
1354 	metaslab_t ms;
1355 	uintptr_t msp;
1356 
1357 	if (mw->mw_curvdev >= mw->mw_numvdevs)
1358 		return (WALK_DONE);
1359 
1360 	if (mw->mw_mss == NULL) {
1361 		uintptr_t mssp;
1362 		uintptr_t vdevp;
1363 
1364 		ASSERT(mw->mw_curms == 0);
1365 		ASSERT(mw->mw_nummss == 0);
1366 
1367 		vdevp = mw->mw_vdevs[mw->mw_curvdev];
1368 		if (GETMEMB(vdevp, "vdev", vdev_ms, mssp) ||
1369 		    GETMEMB(vdevp, "vdev", vdev_ms_count, mw->mw_nummss)) {
1370 			return (WALK_ERR);
1371 		}
1372 
1373 		mw->mw_mss = mdb_alloc(mw->mw_nummss * sizeof (void*),
1374 		    UM_SLEEP | UM_GC);
1375 		if (mdb_vread(mw->mw_mss, mw->mw_nummss * sizeof (void*),
1376 		    mssp) == -1) {
1377 			mdb_warn("failed to read vdev_ms at %p", mssp);
1378 			return (WALK_ERR);
1379 		}
1380 	}
1381 
1382 	if (mw->mw_curms >= mw->mw_nummss) {
1383 		mw->mw_mss = NULL;
1384 		mw->mw_curms = 0;
1385 		mw->mw_nummss = 0;
1386 		mw->mw_curvdev++;
1387 		return (WALK_NEXT);
1388 	}
1389 
1390 	msp = mw->mw_mss[mw->mw_curms];
1391 	if (mdb_vread(&ms, sizeof (metaslab_t), msp) == -1) {
1392 		mdb_warn("failed to read metaslab_t at %p", msp);
1393 		return (WALK_ERR);
1394 	}
1395 
1396 	mw->mw_curms++;
1397 
1398 	return (wsp->walk_callback(msp, &ms, wsp->walk_cbdata));
1399 }
1400 
1401 /* ARGSUSED */
1402 static int
1403 metaslab_walk_init(mdb_walk_state_t *wsp)
1404 {
1405 	metaslab_walk_data_t *mw;
1406 	uintptr_t root_vdevp;
1407 	uintptr_t childp;
1408 
1409 	if (wsp->walk_addr == NULL) {
1410 		mdb_warn("must supply address of spa_t\n");
1411 		return (WALK_ERR);
1412 	}
1413 
1414 	mw = mdb_zalloc(sizeof (metaslab_walk_data_t), UM_SLEEP | UM_GC);
1415 
1416 	if (GETMEMB(wsp->walk_addr, "spa", spa_root_vdev, root_vdevp) ||
1417 	    GETMEMB(root_vdevp, "vdev", vdev_children, mw->mw_numvdevs) ||
1418 	    GETMEMB(root_vdevp, "vdev", vdev_child, childp)) {
1419 		return (DCMD_ERR);
1420 	}
1421 
1422 	mw->mw_vdevs = mdb_alloc(mw->mw_numvdevs * sizeof (void *),
1423 	    UM_SLEEP | UM_GC);
1424 	if (mdb_vread(mw->mw_vdevs, mw->mw_numvdevs * sizeof (void *),
1425 	    childp) == -1) {
1426 		mdb_warn("failed to read root vdev children at %p", childp);
1427 		return (DCMD_ERR);
1428 	}
1429 
1430 	wsp->walk_data = mw;
1431 
1432 	return (WALK_NEXT);
1433 }
1434 
1435 typedef struct mdb_spa {
1436 	uintptr_t spa_dsl_pool;
1437 	uintptr_t spa_root_vdev;
1438 } mdb_spa_t;
1439 
1440 typedef struct mdb_dsl_dir {
1441 	uintptr_t dd_phys;
1442 	int64_t dd_space_towrite[TXG_SIZE];
1443 } mdb_dsl_dir_t;
1444 
1445 typedef struct mdb_dsl_dir_phys {
1446 	uint64_t dd_used_bytes;
1447 	uint64_t dd_compressed_bytes;
1448 	uint64_t dd_uncompressed_bytes;
1449 } mdb_dsl_dir_phys_t;
1450 
1451 typedef struct mdb_vdev {
1452 	uintptr_t vdev_parent;
1453 	uintptr_t vdev_ms;
1454 	uint64_t vdev_ms_count;
1455 	vdev_stat_t vdev_stat;
1456 } mdb_vdev_t;
1457 
1458 typedef struct mdb_metaslab {
1459 	space_map_t ms_allocmap[TXG_SIZE];
1460 	space_map_t ms_freemap[TXG_SIZE];
1461 	space_map_t ms_map;
1462 	space_map_obj_t ms_smo;
1463 	space_map_obj_t ms_smo_syncing;
1464 } mdb_metaslab_t;
1465 
1466 typedef struct space_data {
1467 	uint64_t ms_allocmap[TXG_SIZE];
1468 	uint64_t ms_freemap[TXG_SIZE];
1469 	uint64_t ms_map;
1470 	uint64_t avail;
1471 	uint64_t nowavail;
1472 } space_data_t;
1473 
1474 /* ARGSUSED */
1475 static int
1476 space_cb(uintptr_t addr, const void *unknown, void *arg)
1477 {
1478 	space_data_t *sd = arg;
1479 	mdb_metaslab_t ms;
1480 
1481 	if (GETMEMB(addr, "metaslab", ms_allocmap, ms.ms_allocmap) ||
1482 	    GETMEMB(addr, "metaslab", ms_freemap, ms.ms_freemap) ||
1483 	    GETMEMB(addr, "metaslab", ms_map, ms.ms_map) ||
1484 	    GETMEMB(addr, "metaslab", ms_smo, ms.ms_smo) ||
1485 	    GETMEMB(addr, "metaslab", ms_smo_syncing, ms.ms_smo_syncing)) {
1486 		return (WALK_ERR);
1487 	}
1488 
1489 	sd->ms_allocmap[0] += ms.ms_allocmap[0].sm_space;
1490 	sd->ms_allocmap[1] += ms.ms_allocmap[1].sm_space;
1491 	sd->ms_allocmap[2] += ms.ms_allocmap[2].sm_space;
1492 	sd->ms_allocmap[3] += ms.ms_allocmap[3].sm_space;
1493 	sd->ms_freemap[0] += ms.ms_freemap[0].sm_space;
1494 	sd->ms_freemap[1] += ms.ms_freemap[1].sm_space;
1495 	sd->ms_freemap[2] += ms.ms_freemap[2].sm_space;
1496 	sd->ms_freemap[3] += ms.ms_freemap[3].sm_space;
1497 	sd->ms_map += ms.ms_map.sm_space;
1498 	sd->avail += ms.ms_map.sm_size - ms.ms_smo.smo_alloc;
1499 	sd->nowavail += ms.ms_map.sm_size - ms.ms_smo_syncing.smo_alloc;
1500 
1501 	return (WALK_NEXT);
1502 }
1503 
1504 /*
1505  * ::spa_space [-b]
1506  *
1507  * Given a spa_t, print out it's on-disk space usage and in-core
1508  * estimates of future usage.  If -b is given, print space in bytes.
1509  * Otherwise print in megabytes.
1510  */
1511 /* ARGSUSED */
1512 static int
1513 spa_space(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
1514 {
1515 	mdb_spa_t spa;
1516 	uintptr_t dp_root_dir;
1517 	mdb_dsl_dir_t dd;
1518 	mdb_dsl_dir_phys_t dsp;
1519 	uint64_t children;
1520 	uintptr_t childaddr;
1521 	space_data_t sd;
1522 	int shift = 20;
1523 	char *suffix = "M";
1524 	int bytes = B_FALSE;
1525 
1526 	if (mdb_getopts(argc, argv, 'b', MDB_OPT_SETBITS, TRUE, &bytes, NULL) !=
1527 	    argc)
1528 		return (DCMD_USAGE);
1529 	if (!(flags & DCMD_ADDRSPEC))
1530 		return (DCMD_USAGE);
1531 
1532 	if (bytes) {
1533 		shift = 0;
1534 		suffix = "";
1535 	}
1536 
1537 	if (GETMEMB(addr, "spa", spa_dsl_pool, spa.spa_dsl_pool) ||
1538 	    GETMEMB(addr, "spa", spa_root_vdev, spa.spa_root_vdev) ||
1539 	    GETMEMB(spa.spa_root_vdev, "vdev", vdev_children, children) ||
1540 	    GETMEMB(spa.spa_root_vdev, "vdev", vdev_child, childaddr) ||
1541 	    GETMEMB(spa.spa_dsl_pool, "dsl_pool",
1542 	    dp_root_dir, dp_root_dir) ||
1543 	    GETMEMB(dp_root_dir, "dsl_dir", dd_phys, dd.dd_phys) ||
1544 	    GETMEMB(dp_root_dir, "dsl_dir",
1545 	    dd_space_towrite, dd.dd_space_towrite) ||
1546 	    GETMEMB(dd.dd_phys, "dsl_dir_phys",
1547 	    dd_used_bytes, dsp.dd_used_bytes) ||
1548 	    GETMEMB(dd.dd_phys, "dsl_dir_phys",
1549 	    dd_compressed_bytes, dsp.dd_compressed_bytes) ||
1550 	    GETMEMB(dd.dd_phys, "dsl_dir_phys",
1551 	    dd_uncompressed_bytes, dsp.dd_uncompressed_bytes)) {
1552 		return (DCMD_ERR);
1553 	}
1554 
1555 	mdb_printf("dd_space_towrite = %llu%s %llu%s %llu%s %llu%s\n",
1556 	    dd.dd_space_towrite[0] >> shift, suffix,
1557 	    dd.dd_space_towrite[1] >> shift, suffix,
1558 	    dd.dd_space_towrite[2] >> shift, suffix,
1559 	    dd.dd_space_towrite[3] >> shift, suffix);
1560 
1561 	mdb_printf("dd_phys.dd_used_bytes = %llu%s\n",
1562 	    dsp.dd_used_bytes >> shift, suffix);
1563 	mdb_printf("dd_phys.dd_compressed_bytes = %llu%s\n",
1564 	    dsp.dd_compressed_bytes >> shift, suffix);
1565 	mdb_printf("dd_phys.dd_uncompressed_bytes = %llu%s\n",
1566 	    dsp.dd_uncompressed_bytes >> shift, suffix);
1567 
1568 	bzero(&sd, sizeof (sd));
1569 	if (mdb_pwalk("metaslab", space_cb, &sd, addr) != 0) {
1570 		mdb_warn("can't walk metaslabs");
1571 		return (DCMD_ERR);
1572 	}
1573 
1574 	mdb_printf("ms_allocmap = %llu%s %llu%s %llu%s %llu%s\n",
1575 	    sd.ms_allocmap[0] >> shift, suffix,
1576 	    sd.ms_allocmap[1] >> shift, suffix,
1577 	    sd.ms_allocmap[2] >> shift, suffix,
1578 	    sd.ms_allocmap[3] >> shift, suffix);
1579 	mdb_printf("ms_freemap = %llu%s %llu%s %llu%s %llu%s\n",
1580 	    sd.ms_freemap[0] >> shift, suffix,
1581 	    sd.ms_freemap[1] >> shift, suffix,
1582 	    sd.ms_freemap[2] >> shift, suffix,
1583 	    sd.ms_freemap[3] >> shift, suffix);
1584 	mdb_printf("ms_map = %llu%s\n", sd.ms_map >> shift, suffix);
1585 	mdb_printf("last synced avail = %llu%s\n", sd.avail >> shift, suffix);
1586 	mdb_printf("current syncing avail = %llu%s\n",
1587 	    sd.nowavail >> shift, suffix);
1588 
1589 	return (DCMD_OK);
1590 }
1591 
1592 typedef struct mdb_spa_aux_vdev {
1593 	int sav_count;
1594 	uintptr_t sav_vdevs;
1595 } mdb_spa_aux_vdev_t;
1596 
1597 typedef struct mdb_spa_vdevs {
1598 	uintptr_t spa_root_vdev;
1599 	mdb_spa_aux_vdev_t spa_l2cache;
1600 	mdb_spa_aux_vdev_t spa_spares;
1601 } mdb_spa_vdevs_t;
1602 
1603 static int
1604 spa_print_aux(mdb_spa_aux_vdev_t *sav, uint_t flags, mdb_arg_t *v,
1605     const char *name)
1606 {
1607 	uintptr_t *aux;
1608 	size_t len;
1609 	int ret, i;
1610 
1611 	/*
1612 	 * Iterate over aux vdevs and print those out as well.  This is a
1613 	 * little annoying because we don't have a root vdev to pass to ::vdev.
1614 	 * Instead, we print a single line and then call it for each child
1615 	 * vdev.
1616 	 */
1617 	if (sav->sav_count != 0) {
1618 		v[1].a_type = MDB_TYPE_STRING;
1619 		v[1].a_un.a_str = "-d";
1620 		v[2].a_type = MDB_TYPE_IMMEDIATE;
1621 		v[2].a_un.a_val = 2;
1622 
1623 		len = sav->sav_count * sizeof (uintptr_t);
1624 		aux = mdb_alloc(len, UM_SLEEP);
1625 		if (mdb_vread(aux, len, sav->sav_vdevs) == -1) {
1626 			mdb_free(aux, len);
1627 			mdb_warn("failed to read l2cache vdevs at %p",
1628 			    sav->sav_vdevs);
1629 			return (DCMD_ERR);
1630 		}
1631 
1632 		mdb_printf("%-?s %-9s %-12s %s\n", "-", "-", "-", name);
1633 
1634 		for (i = 0; i < sav->sav_count; i++) {
1635 			ret = mdb_call_dcmd("vdev", aux[i], flags, 3, v);
1636 			if (ret != DCMD_OK) {
1637 				mdb_free(aux, len);
1638 				return (ret);
1639 			}
1640 		}
1641 
1642 		mdb_free(aux, len);
1643 	}
1644 
1645 	return (0);
1646 }
1647 
1648 /*
1649  * ::spa_vdevs
1650  *
1651  * 	-e	Include error stats
1652  *
1653  * Print out a summarized list of vdevs for the given spa_t.
1654  * This is accomplished by invoking "::vdev -re" on the root vdev, as well as
1655  * iterating over the cache devices.
1656  */
1657 /* ARGSUSED */
1658 static int
1659 spa_vdevs(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
1660 {
1661 	mdb_arg_t v[3];
1662 	int errors = FALSE;
1663 	int ret;
1664 
1665 	if (mdb_getopts(argc, argv,
1666 	    'e', MDB_OPT_SETBITS, TRUE, &errors,
1667 	    NULL) != argc)
1668 		return (DCMD_USAGE);
1669 
1670 	if (!(flags & DCMD_ADDRSPEC))
1671 		return (DCMD_USAGE);
1672 
1673 	mdb_spa_vdevs_t spa;
1674 	if (mdb_ctf_vread(&spa, "spa_t", "mdb_spa_vdevs_t", addr, 0) == -1)
1675 		return (DCMD_ERR);
1676 
1677 	/*
1678 	 * Unitialized spa_t structures can have a NULL root vdev.
1679 	 */
1680 	if (spa.spa_root_vdev == NULL) {
1681 		mdb_printf("no associated vdevs\n");
1682 		return (DCMD_OK);
1683 	}
1684 
1685 	v[0].a_type = MDB_TYPE_STRING;
1686 	v[0].a_un.a_str = errors ? "-re" : "-r";
1687 
1688 	ret = mdb_call_dcmd("vdev", (uintptr_t)spa.spa_root_vdev,
1689 	    flags, 1, v);
1690 	if (ret != DCMD_OK)
1691 		return (ret);
1692 
1693 	if (spa_print_aux(&spa.spa_l2cache, flags, v, "cache") != 0 ||
1694 	    spa_print_aux(&spa.spa_spares, flags, v, "spares") != 0)
1695 		return (DCMD_ERR);
1696 
1697 	return (DCMD_OK);
1698 }
1699 
1700 /*
1701  * ::zio
1702  *
1703  * Print a summary of zio_t and all its children.  This is intended to display a
1704  * zio tree, and hence we only pick the most important pieces of information for
1705  * the main summary.  More detailed information can always be found by doing a
1706  * '::print zio' on the underlying zio_t.  The columns we display are:
1707  *
1708  *	ADDRESS  TYPE  STAGE  WAITER  TIME_ELAPSED
1709  *
1710  * The 'address' column is indented by one space for each depth level as we
1711  * descend down the tree.
1712  */
1713 
1714 #define	ZIO_MAXINDENT	7
1715 #define	ZIO_MAXWIDTH	(sizeof (uintptr_t) * 2 + ZIO_MAXINDENT)
1716 #define	ZIO_WALK_SELF	0
1717 #define	ZIO_WALK_CHILD	1
1718 #define	ZIO_WALK_PARENT	2
1719 
1720 typedef struct zio_print_args {
1721 	int	zpa_current_depth;
1722 	int	zpa_min_depth;
1723 	int	zpa_max_depth;
1724 	int	zpa_type;
1725 	uint_t	zpa_flags;
1726 } zio_print_args_t;
1727 
1728 typedef struct mdb_zio {
1729 	enum zio_type io_type;
1730 	enum zio_stage io_stage;
1731 	uintptr_t io_waiter;
1732 	uintptr_t io_spa;
1733 	struct {
1734 		struct {
1735 			uintptr_t list_next;
1736 		} list_head;
1737 	} io_parent_list;
1738 	int io_error;
1739 } mdb_zio_t;
1740 
1741 typedef struct mdb_zio_timestamp {
1742 	hrtime_t io_timestamp;
1743 } mdb_zio_timestamp_t;
1744 
1745 static int zio_child_cb(uintptr_t addr, const void *unknown, void *arg);
1746 
1747 static int
1748 zio_print_cb(uintptr_t addr, zio_print_args_t *zpa)
1749 {
1750 	mdb_ctf_id_t type_enum, stage_enum;
1751 	int indent = zpa->zpa_current_depth;
1752 	const char *type, *stage;
1753 	uintptr_t laddr;
1754 	mdb_zio_t zio;
1755 	mdb_zio_timestamp_t zio_timestamp = { 0 };
1756 
1757 	if (mdb_ctf_vread(&zio, ZFS_STRUCT "zio", "mdb_zio_t", addr, 0) == -1)
1758 		return (WALK_ERR);
1759 	(void) mdb_ctf_vread(&zio_timestamp, ZFS_STRUCT "zio",
1760 	    "mdb_zio_timestamp_t", addr, MDB_CTF_VREAD_QUIET);
1761 
1762 	if (indent > ZIO_MAXINDENT)
1763 		indent = ZIO_MAXINDENT;
1764 
1765 	if (mdb_ctf_lookup_by_name("enum zio_type", &type_enum) == -1 ||
1766 	    mdb_ctf_lookup_by_name("enum zio_stage", &stage_enum) == -1) {
1767 		mdb_warn("failed to lookup zio enums");
1768 		return (WALK_ERR);
1769 	}
1770 
1771 	if ((type = mdb_ctf_enum_name(type_enum, zio.io_type)) != NULL)
1772 		type += sizeof ("ZIO_TYPE_") - 1;
1773 	else
1774 		type = "?";
1775 
1776 	if (zio.io_error == 0) {
1777 		stage = mdb_ctf_enum_name(stage_enum, zio.io_stage);
1778 		if (stage != NULL)
1779 			stage += sizeof ("ZIO_STAGE_") - 1;
1780 		else
1781 			stage = "?";
1782 	} else {
1783 		stage = "FAILED";
1784 	}
1785 
1786 	if (zpa->zpa_current_depth >= zpa->zpa_min_depth) {
1787 		if (zpa->zpa_flags & DCMD_PIPE_OUT) {
1788 			mdb_printf("%?p\n", addr);
1789 		} else {
1790 			mdb_printf("%*s%-*p %-5s %-16s ", indent, "",
1791 			    ZIO_MAXWIDTH - indent, addr, type, stage);
1792 			if (zio.io_waiter != 0)
1793 				mdb_printf("%-16lx ", zio.io_waiter);
1794 			else
1795 				mdb_printf("%-16s ", "-");
1796 #ifdef _KERNEL
1797 			if (zio_timestamp.io_timestamp != 0) {
1798 				mdb_printf("%llums", (mdb_gethrtime() -
1799 				    zio_timestamp.io_timestamp) /
1800 				    1000000);
1801 			} else {
1802 				mdb_printf("%-12s ", "-");
1803 			}
1804 #else
1805 			mdb_printf("%-12s ", "-");
1806 #endif
1807 			mdb_printf("\n");
1808 		}
1809 	}
1810 
1811 	if (zpa->zpa_current_depth >= zpa->zpa_max_depth)
1812 		return (WALK_NEXT);
1813 
1814 	if (zpa->zpa_type == ZIO_WALK_PARENT)
1815 		laddr = addr + mdb_ctf_offsetof_by_name(ZFS_STRUCT "zio",
1816 		    "io_parent_list");
1817 	else
1818 		laddr = addr + mdb_ctf_offsetof_by_name(ZFS_STRUCT "zio",
1819 		    "io_child_list");
1820 
1821 	zpa->zpa_current_depth++;
1822 	if (mdb_pwalk("list", zio_child_cb, zpa, laddr) != 0) {
1823 		mdb_warn("failed to walk zio_t children at %p\n", laddr);
1824 		return (WALK_ERR);
1825 	}
1826 	zpa->zpa_current_depth--;
1827 
1828 	return (WALK_NEXT);
1829 }
1830 
1831 /* ARGSUSED */
1832 static int
1833 zio_child_cb(uintptr_t addr, const void *unknown, void *arg)
1834 {
1835 	zio_link_t zl;
1836 	uintptr_t ziop;
1837 	zio_print_args_t *zpa = arg;
1838 
1839 	if (mdb_vread(&zl, sizeof (zl), addr) == -1) {
1840 		mdb_warn("failed to read zio_link_t at %p", addr);
1841 		return (WALK_ERR);
1842 	}
1843 
1844 	if (zpa->zpa_type == ZIO_WALK_PARENT)
1845 		ziop = (uintptr_t)zl.zl_parent;
1846 	else
1847 		ziop = (uintptr_t)zl.zl_child;
1848 
1849 	return (zio_print_cb(ziop, zpa));
1850 }
1851 
1852 /* ARGSUSED */
1853 static int
1854 zio_print(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
1855 {
1856 	zio_print_args_t zpa = { 0 };
1857 
1858 	if (!(flags & DCMD_ADDRSPEC))
1859 		return (DCMD_USAGE);
1860 
1861 	if (mdb_getopts(argc, argv,
1862 	    'r', MDB_OPT_SETBITS, INT_MAX, &zpa.zpa_max_depth,
1863 	    'c', MDB_OPT_SETBITS, ZIO_WALK_CHILD, &zpa.zpa_type,
1864 	    'p', MDB_OPT_SETBITS, ZIO_WALK_PARENT, &zpa.zpa_type,
1865 	    NULL) != argc)
1866 		return (DCMD_USAGE);
1867 
1868 	zpa.zpa_flags = flags;
1869 	if (zpa.zpa_max_depth != 0) {
1870 		if (zpa.zpa_type == ZIO_WALK_SELF)
1871 			zpa.zpa_type = ZIO_WALK_CHILD;
1872 	} else if (zpa.zpa_type != ZIO_WALK_SELF) {
1873 		zpa.zpa_min_depth = 1;
1874 		zpa.zpa_max_depth = 1;
1875 	}
1876 
1877 	if (!(flags & DCMD_PIPE_OUT) && DCMD_HDRSPEC(flags)) {
1878 		mdb_printf("%<u>%-*s %-5s %-16s %-16s %-12s%</u>\n",
1879 		    ZIO_MAXWIDTH, "ADDRESS", "TYPE", "STAGE", "WAITER",
1880 		    "TIME_ELAPSED");
1881 	}
1882 
1883 	if (zio_print_cb(addr, &zpa) != WALK_NEXT)
1884 		return (DCMD_ERR);
1885 
1886 	return (DCMD_OK);
1887 }
1888 
1889 /*
1890  * [addr]::zio_state
1891  *
1892  * Print a summary of all zio_t structures on the system, or for a particular
1893  * pool.  This is equivalent to '::walk zio_root | ::zio'.
1894  */
1895 /*ARGSUSED*/
1896 static int
1897 zio_state(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
1898 {
1899 	/*
1900 	 * MDB will remember the last address of the pipeline, so if we don't
1901 	 * zero this we'll end up trying to walk zio structures for a
1902 	 * non-existent spa_t.
1903 	 */
1904 	if (!(flags & DCMD_ADDRSPEC))
1905 		addr = 0;
1906 
1907 	return (mdb_pwalk_dcmd("zio_root", "zio", argc, argv, addr));
1908 }
1909 
1910 typedef struct txg_list_walk_data {
1911 	uintptr_t lw_head[TXG_SIZE];
1912 	int	lw_txgoff;
1913 	int	lw_maxoff;
1914 	size_t	lw_offset;
1915 	void	*lw_obj;
1916 } txg_list_walk_data_t;
1917 
1918 static int
1919 txg_list_walk_init_common(mdb_walk_state_t *wsp, int txg, int maxoff)
1920 {
1921 	txg_list_walk_data_t *lwd;
1922 	txg_list_t list;
1923 	int i;
1924 
1925 	lwd = mdb_alloc(sizeof (txg_list_walk_data_t), UM_SLEEP | UM_GC);
1926 	if (mdb_vread(&list, sizeof (txg_list_t), wsp->walk_addr) == -1) {
1927 		mdb_warn("failed to read txg_list_t at %#lx", wsp->walk_addr);
1928 		return (WALK_ERR);
1929 	}
1930 
1931 	for (i = 0; i < TXG_SIZE; i++)
1932 		lwd->lw_head[i] = (uintptr_t)list.tl_head[i];
1933 	lwd->lw_offset = list.tl_offset;
1934 	lwd->lw_obj = mdb_alloc(lwd->lw_offset + sizeof (txg_node_t),
1935 	    UM_SLEEP | UM_GC);
1936 	lwd->lw_txgoff = txg;
1937 	lwd->lw_maxoff = maxoff;
1938 
1939 	wsp->walk_addr = lwd->lw_head[lwd->lw_txgoff];
1940 	wsp->walk_data = lwd;
1941 
1942 	return (WALK_NEXT);
1943 }
1944 
1945 static int
1946 txg_list_walk_init(mdb_walk_state_t *wsp)
1947 {
1948 	return (txg_list_walk_init_common(wsp, 0, TXG_SIZE-1));
1949 }
1950 
1951 static int
1952 txg_list0_walk_init(mdb_walk_state_t *wsp)
1953 {
1954 	return (txg_list_walk_init_common(wsp, 0, 0));
1955 }
1956 
1957 static int
1958 txg_list1_walk_init(mdb_walk_state_t *wsp)
1959 {
1960 	return (txg_list_walk_init_common(wsp, 1, 1));
1961 }
1962 
1963 static int
1964 txg_list2_walk_init(mdb_walk_state_t *wsp)
1965 {
1966 	return (txg_list_walk_init_common(wsp, 2, 2));
1967 }
1968 
1969 static int
1970 txg_list3_walk_init(mdb_walk_state_t *wsp)
1971 {
1972 	return (txg_list_walk_init_common(wsp, 3, 3));
1973 }
1974 
1975 static int
1976 txg_list_walk_step(mdb_walk_state_t *wsp)
1977 {
1978 	txg_list_walk_data_t *lwd = wsp->walk_data;
1979 	uintptr_t addr;
1980 	txg_node_t *node;
1981 	int status;
1982 
1983 	while (wsp->walk_addr == NULL && lwd->lw_txgoff < lwd->lw_maxoff) {
1984 		lwd->lw_txgoff++;
1985 		wsp->walk_addr = lwd->lw_head[lwd->lw_txgoff];
1986 	}
1987 
1988 	if (wsp->walk_addr == NULL)
1989 		return (WALK_DONE);
1990 
1991 	addr = wsp->walk_addr - lwd->lw_offset;
1992 
1993 	if (mdb_vread(lwd->lw_obj,
1994 	    lwd->lw_offset + sizeof (txg_node_t), addr) == -1) {
1995 		mdb_warn("failed to read list element at %#lx", addr);
1996 		return (WALK_ERR);
1997 	}
1998 
1999 	status = wsp->walk_callback(addr, lwd->lw_obj, wsp->walk_cbdata);
2000 	node = (txg_node_t *)((uintptr_t)lwd->lw_obj + lwd->lw_offset);
2001 	wsp->walk_addr = (uintptr_t)node->tn_next[lwd->lw_txgoff];
2002 
2003 	return (status);
2004 }
2005 
2006 /*
2007  * ::walk spa
2008  *
2009  * Walk all named spa_t structures in the namespace.  This is nothing more than
2010  * a layered avl walk.
2011  */
2012 static int
2013 spa_walk_init(mdb_walk_state_t *wsp)
2014 {
2015 	GElf_Sym sym;
2016 
2017 	if (wsp->walk_addr != NULL) {
2018 		mdb_warn("spa walk only supports global walks\n");
2019 		return (WALK_ERR);
2020 	}
2021 
2022 	if (mdb_lookup_by_obj(ZFS_OBJ_NAME, "spa_namespace_avl", &sym) == -1) {
2023 		mdb_warn("failed to find symbol 'spa_namespace_avl'");
2024 		return (WALK_ERR);
2025 	}
2026 
2027 	wsp->walk_addr = (uintptr_t)sym.st_value;
2028 
2029 	if (mdb_layered_walk("avl", wsp) == -1) {
2030 		mdb_warn("failed to walk 'avl'\n");
2031 		return (WALK_ERR);
2032 	}
2033 
2034 	return (WALK_NEXT);
2035 }
2036 
2037 static int
2038 spa_walk_step(mdb_walk_state_t *wsp)
2039 {
2040 	return (wsp->walk_callback(wsp->walk_addr, NULL, wsp->walk_cbdata));
2041 }
2042 
2043 /*
2044  * [addr]::walk zio
2045  *
2046  * Walk all active zio_t structures on the system.  This is simply a layered
2047  * walk on top of ::walk zio_cache, with the optional ability to limit the
2048  * structures to a particular pool.
2049  */
2050 static int
2051 zio_walk_init(mdb_walk_state_t *wsp)
2052 {
2053 	wsp->walk_data = &wsp->walk_addr;
2054 
2055 	if (mdb_layered_walk("zio_cache", wsp) == -1) {
2056 		mdb_warn("failed to walk 'zio_cache'\n");
2057 		return (WALK_ERR);
2058 	}
2059 
2060 	return (WALK_NEXT);
2061 }
2062 
2063 static int
2064 zio_walk_step(mdb_walk_state_t *wsp)
2065 {
2066 	mdb_zio_t zio;
2067 	uintptr_t *spap = wsp->walk_data;
2068 
2069 	if (mdb_ctf_vread(&zio, ZFS_STRUCT "zio", "mdb_zio_t",
2070 	    wsp->walk_addr, 0) == -1)
2071 		return (WALK_ERR);
2072 
2073 	if (*spap != 0 && *spap != zio.io_spa)
2074 		return (WALK_NEXT);
2075 
2076 	return (wsp->walk_callback(wsp->walk_addr, &zio, wsp->walk_cbdata));
2077 }
2078 
2079 /*
2080  * [addr]::walk zio_root
2081  *
2082  * Walk only root zio_t structures, optionally for a particular spa_t.
2083  */
2084 static int
2085 zio_walk_root_step(mdb_walk_state_t *wsp)
2086 {
2087 	mdb_zio_t zio;
2088 	uintptr_t *spap = wsp->walk_data;
2089 
2090 	if (mdb_ctf_vread(&zio, ZFS_STRUCT "zio", "mdb_zio_t",
2091 	    wsp->walk_addr, 0) == -1)
2092 		return (WALK_ERR);
2093 
2094 	if (*spap != 0 && *spap != zio.io_spa)
2095 		return (WALK_NEXT);
2096 
2097 	/* If the parent list is not empty, ignore */
2098 	if (zio.io_parent_list.list_head.list_next !=
2099 	    wsp->walk_addr +
2100 	    mdb_ctf_offsetof_by_name(ZFS_STRUCT "zio", "io_parent_list") +
2101 	    mdb_ctf_offsetof_by_name("struct list", "list_head"))
2102 		return (WALK_NEXT);
2103 
2104 	return (wsp->walk_callback(wsp->walk_addr, &zio, wsp->walk_cbdata));
2105 }
2106 
2107 #define	NICENUM_BUFLEN 6
2108 
2109 static int
2110 snprintfrac(char *buf, int len,
2111     uint64_t numerator, uint64_t denom, int frac_digits)
2112 {
2113 	int mul = 1;
2114 	int whole, frac, i;
2115 
2116 	for (i = frac_digits; i; i--)
2117 		mul *= 10;
2118 	whole = numerator / denom;
2119 	frac = mul * numerator / denom - mul * whole;
2120 	return (mdb_snprintf(buf, len, "%u.%0*u", whole, frac_digits, frac));
2121 }
2122 
2123 static void
2124 mdb_nicenum(uint64_t num, char *buf)
2125 {
2126 	uint64_t n = num;
2127 	int index = 0;
2128 	char *u;
2129 
2130 	while (n >= 1024) {
2131 		n = (n + (1024 / 2)) / 1024; /* Round up or down */
2132 		index++;
2133 	}
2134 
2135 	u = &" \0K\0M\0G\0T\0P\0E\0"[index*2];
2136 
2137 	if (index == 0) {
2138 		(void) mdb_snprintf(buf, NICENUM_BUFLEN, "%llu",
2139 		    (u_longlong_t)n);
2140 	} else if (n < 10 && (num & (num - 1)) != 0) {
2141 		(void) snprintfrac(buf, NICENUM_BUFLEN,
2142 		    num, 1ULL << 10 * index, 2);
2143 		strcat(buf, u);
2144 	} else if (n < 100 && (num & (num - 1)) != 0) {
2145 		(void) snprintfrac(buf, NICENUM_BUFLEN,
2146 		    num, 1ULL << 10 * index, 1);
2147 		strcat(buf, u);
2148 	} else {
2149 		(void) mdb_snprintf(buf, NICENUM_BUFLEN, "%llu%s",
2150 		    (u_longlong_t)n, u);
2151 	}
2152 }
2153 
2154 /*
2155  * ::zfs_blkstats
2156  *
2157  * 	-v	print verbose per-level information
2158  *
2159  */
2160 static int
2161 zfs_blkstats(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
2162 {
2163 	boolean_t verbose = B_FALSE;
2164 	zfs_all_blkstats_t stats;
2165 	dmu_object_type_t t;
2166 	zfs_blkstat_t *tzb;
2167 	uint64_t ditto;
2168 	dmu_object_type_info_t dmu_ot[DMU_OT_NUMTYPES + 10];
2169 	/* +10 in case it grew */
2170 
2171 	if (mdb_readvar(&dmu_ot, "dmu_ot") == -1) {
2172 		mdb_warn("failed to read 'dmu_ot'");
2173 		return (DCMD_ERR);
2174 	}
2175 
2176 	if (mdb_getopts(argc, argv,
2177 	    'v', MDB_OPT_SETBITS, TRUE, &verbose,
2178 	    NULL) != argc)
2179 		return (DCMD_USAGE);
2180 
2181 	if (!(flags & DCMD_ADDRSPEC))
2182 		return (DCMD_USAGE);
2183 
2184 	if (GETMEMB(addr, "spa", spa_dsl_pool, addr) ||
2185 	    GETMEMB(addr, "dsl_pool", dp_blkstats, addr) ||
2186 	    mdb_vread(&stats, sizeof (zfs_all_blkstats_t), addr) == -1) {
2187 		mdb_warn("failed to read data at %p;", addr);
2188 		mdb_printf("maybe no stats? run \"zpool scrub\" first.");
2189 		return (DCMD_ERR);
2190 	}
2191 
2192 	tzb = &stats.zab_type[DN_MAX_LEVELS][DMU_OT_TOTAL];
2193 	if (tzb->zb_gangs != 0) {
2194 		mdb_printf("Ganged blocks: %llu\n",
2195 		    (longlong_t)tzb->zb_gangs);
2196 	}
2197 
2198 	ditto = tzb->zb_ditto_2_of_2_samevdev + tzb->zb_ditto_2_of_3_samevdev +
2199 	    tzb->zb_ditto_3_of_3_samevdev;
2200 	if (ditto != 0) {
2201 		mdb_printf("Dittoed blocks on same vdev: %llu\n",
2202 		    (longlong_t)ditto);
2203 	}
2204 
2205 	mdb_printf("\nBlocks\tLSIZE\tPSIZE\tASIZE"
2206 	    "\t  avg\t comp\t%%Total\tType\n");
2207 
2208 	for (t = 0; t <= DMU_OT_TOTAL; t++) {
2209 		char csize[NICENUM_BUFLEN], lsize[NICENUM_BUFLEN];
2210 		char psize[NICENUM_BUFLEN], asize[NICENUM_BUFLEN];
2211 		char avg[NICENUM_BUFLEN];
2212 		char comp[NICENUM_BUFLEN], pct[NICENUM_BUFLEN];
2213 		char typename[64];
2214 		int l;
2215 
2216 
2217 		if (t == DMU_OT_DEFERRED)
2218 			strcpy(typename, "deferred free");
2219 		else if (t == DMU_OT_OTHER)
2220 			strcpy(typename, "other");
2221 		else if (t == DMU_OT_TOTAL)
2222 			strcpy(typename, "Total");
2223 		else if (mdb_readstr(typename, sizeof (typename),
2224 		    (uintptr_t)dmu_ot[t].ot_name) == -1) {
2225 			mdb_warn("failed to read type name");
2226 			return (DCMD_ERR);
2227 		}
2228 
2229 		if (stats.zab_type[DN_MAX_LEVELS][t].zb_asize == 0)
2230 			continue;
2231 
2232 		for (l = -1; l < DN_MAX_LEVELS; l++) {
2233 			int level = (l == -1 ? DN_MAX_LEVELS : l);
2234 			zfs_blkstat_t *zb = &stats.zab_type[level][t];
2235 
2236 			if (zb->zb_asize == 0)
2237 				continue;
2238 
2239 			/*
2240 			 * Don't print each level unless requested.
2241 			 */
2242 			if (!verbose && level != DN_MAX_LEVELS)
2243 				continue;
2244 
2245 			/*
2246 			 * If all the space is level 0, don't print the
2247 			 * level 0 separately.
2248 			 */
2249 			if (level == 0 && zb->zb_asize ==
2250 			    stats.zab_type[DN_MAX_LEVELS][t].zb_asize)
2251 				continue;
2252 
2253 			mdb_nicenum(zb->zb_count, csize);
2254 			mdb_nicenum(zb->zb_lsize, lsize);
2255 			mdb_nicenum(zb->zb_psize, psize);
2256 			mdb_nicenum(zb->zb_asize, asize);
2257 			mdb_nicenum(zb->zb_asize / zb->zb_count, avg);
2258 			(void) snprintfrac(comp, NICENUM_BUFLEN,
2259 			    zb->zb_lsize, zb->zb_psize, 2);
2260 			(void) snprintfrac(pct, NICENUM_BUFLEN,
2261 			    100 * zb->zb_asize, tzb->zb_asize, 2);
2262 
2263 			mdb_printf("%6s\t%5s\t%5s\t%5s\t%5s"
2264 			    "\t%5s\t%6s\t",
2265 			    csize, lsize, psize, asize, avg, comp, pct);
2266 
2267 			if (level == DN_MAX_LEVELS)
2268 				mdb_printf("%s\n", typename);
2269 			else
2270 				mdb_printf("  L%d %s\n",
2271 				    level, typename);
2272 		}
2273 	}
2274 
2275 	return (DCMD_OK);
2276 }
2277 
2278 typedef struct mdb_reference {
2279 	uintptr_t ref_holder;
2280 	uintptr_t ref_removed;
2281 	uint64_t ref_number;
2282 } mdb_reference_t;
2283 
2284 /* ARGSUSED */
2285 static int
2286 reference_cb(uintptr_t addr, const void *ignored, void *arg)
2287 {
2288 	mdb_reference_t ref;
2289 	boolean_t holder_is_str = B_FALSE;
2290 	char holder_str[128];
2291 	boolean_t removed = (boolean_t)arg;
2292 
2293 	if (mdb_ctf_vread(&ref, "reference_t", "mdb_reference_t", addr,
2294 	    0) == -1)
2295 		return (DCMD_ERR);
2296 
2297 	if (mdb_readstr(holder_str, sizeof (holder_str),
2298 	    ref.ref_holder) != -1)
2299 		holder_is_str = strisprint(holder_str);
2300 
2301 	if (removed)
2302 		mdb_printf("removed ");
2303 	mdb_printf("reference ");
2304 	if (ref.ref_number != 1)
2305 		mdb_printf("with count=%llu ", ref.ref_number);
2306 	mdb_printf("with tag %lx", ref.ref_holder);
2307 	if (holder_is_str)
2308 		mdb_printf(" \"%s\"", holder_str);
2309 	mdb_printf(", held at:\n");
2310 
2311 	(void) mdb_call_dcmd("whatis", addr, DCMD_ADDRSPEC, 0, NULL);
2312 
2313 	if (removed) {
2314 		mdb_printf("removed at:\n");
2315 		(void) mdb_call_dcmd("whatis", ref.ref_removed,
2316 		    DCMD_ADDRSPEC, 0, NULL);
2317 	}
2318 
2319 	mdb_printf("\n");
2320 
2321 	return (WALK_NEXT);
2322 }
2323 
2324 typedef struct mdb_refcount {
2325 	uint64_t rc_count;
2326 } mdb_refcount_t;
2327 
2328 typedef struct mdb_refcount_removed {
2329 	uint64_t rc_removed_count;
2330 } mdb_refcount_removed_t;
2331 
2332 typedef struct mdb_refcount_tracked {
2333 	boolean_t rc_tracked;
2334 } mdb_refcount_tracked_t;
2335 
2336 /* ARGSUSED */
2337 static int
2338 refcount(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
2339 {
2340 	mdb_refcount_t rc;
2341 	mdb_refcount_removed_t rcr;
2342 	mdb_refcount_tracked_t rct;
2343 	int off;
2344 	boolean_t released = B_FALSE;
2345 
2346 	if (!(flags & DCMD_ADDRSPEC))
2347 		return (DCMD_USAGE);
2348 
2349 	if (mdb_getopts(argc, argv,
2350 	    'r', MDB_OPT_SETBITS, B_TRUE, &released,
2351 	    NULL) != argc)
2352 		return (DCMD_USAGE);
2353 
2354 	if (mdb_ctf_vread(&rc, "refcount_t", "mdb_refcount_t", addr,
2355 	    0) == -1)
2356 		return (DCMD_ERR);
2357 
2358 	if (mdb_ctf_vread(&rcr, "refcount_t", "mdb_refcount_removed_t", addr,
2359 	    MDB_CTF_VREAD_QUIET) == -1) {
2360 		mdb_printf("refcount_t at %p has %llu holds (untracked)\n",
2361 		    addr, (longlong_t)rc.rc_count);
2362 		return (DCMD_OK);
2363 	}
2364 
2365 	if (mdb_ctf_vread(&rct, "refcount_t", "mdb_refcount_tracked_t", addr,
2366 	    MDB_CTF_VREAD_QUIET) == -1) {
2367 		/* If this is an old target, it might be tracked. */
2368 		rct.rc_tracked = B_TRUE;
2369 	}
2370 
2371 	mdb_printf("refcount_t at %p has %llu current holds, "
2372 	    "%llu recently released holds\n",
2373 	    addr, (longlong_t)rc.rc_count, (longlong_t)rcr.rc_removed_count);
2374 
2375 	if (rct.rc_tracked && rc.rc_count > 0)
2376 		mdb_printf("current holds:\n");
2377 	off = mdb_ctf_offsetof_by_name("refcount_t", "rc_list");
2378 	if (off == -1)
2379 		return (DCMD_ERR);
2380 	mdb_pwalk("list", reference_cb, (void*)B_FALSE, addr + off);
2381 
2382 	if (released && rcr.rc_removed_count > 0) {
2383 		mdb_printf("released holds:\n");
2384 
2385 		off = mdb_ctf_offsetof_by_name("refcount_t", "rc_removed");
2386 		if (off == -1)
2387 			return (DCMD_ERR);
2388 		mdb_pwalk("list", reference_cb, (void*)B_FALSE, addr + off);
2389 	}
2390 
2391 	return (DCMD_OK);
2392 }
2393 
2394 /* ARGSUSED */
2395 static int
2396 sa_attr_table(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
2397 {
2398 	sa_attr_table_t *table;
2399 	sa_os_t sa_os;
2400 	char *name;
2401 	int i;
2402 
2403 	if (mdb_vread(&sa_os, sizeof (sa_os_t), addr) == -1) {
2404 		mdb_warn("failed to read sa_os at %p", addr);
2405 		return (DCMD_ERR);
2406 	}
2407 
2408 	table = mdb_alloc(sizeof (sa_attr_table_t) * sa_os.sa_num_attrs,
2409 	    UM_SLEEP | UM_GC);
2410 	name = mdb_alloc(MAXPATHLEN, UM_SLEEP | UM_GC);
2411 
2412 	if (mdb_vread(table, sizeof (sa_attr_table_t) * sa_os.sa_num_attrs,
2413 	    (uintptr_t)sa_os.sa_attr_table) == -1) {
2414 		mdb_warn("failed to read sa_os at %p", addr);
2415 		return (DCMD_ERR);
2416 	}
2417 
2418 	mdb_printf("%<u>%-10s %-10s %-10s %-10s %s%</u>\n",
2419 	    "ATTR ID", "REGISTERED", "LENGTH", "BSWAP", "NAME");
2420 	for (i = 0; i != sa_os.sa_num_attrs; i++) {
2421 		mdb_readstr(name, MAXPATHLEN, (uintptr_t)table[i].sa_name);
2422 		mdb_printf("%5x   %8x %8x %8x          %-s\n",
2423 		    (int)table[i].sa_attr, (int)table[i].sa_registered,
2424 		    (int)table[i].sa_length, table[i].sa_byteswap, name);
2425 	}
2426 
2427 	return (DCMD_OK);
2428 }
2429 
2430 static int
2431 sa_get_off_table(uintptr_t addr, uint32_t **off_tab, int attr_count)
2432 {
2433 	uintptr_t idx_table;
2434 
2435 	if (GETMEMB(addr, "sa_idx_tab", sa_idx_tab, idx_table)) {
2436 		mdb_printf("can't find offset table in sa_idx_tab\n");
2437 		return (-1);
2438 	}
2439 
2440 	*off_tab = mdb_alloc(attr_count * sizeof (uint32_t),
2441 	    UM_SLEEP | UM_GC);
2442 
2443 	if (mdb_vread(*off_tab,
2444 	    attr_count * sizeof (uint32_t), idx_table) == -1) {
2445 		mdb_warn("failed to attribute offset table %p", idx_table);
2446 		return (-1);
2447 	}
2448 
2449 	return (DCMD_OK);
2450 }
2451 
2452 /*ARGSUSED*/
2453 static int
2454 sa_attr_print(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
2455 {
2456 	uint32_t *offset_tab;
2457 	int attr_count;
2458 	uint64_t attr_id;
2459 	uintptr_t attr_addr;
2460 	uintptr_t bonus_tab, spill_tab;
2461 	uintptr_t db_bonus, db_spill;
2462 	uintptr_t os, os_sa;
2463 	uintptr_t db_data;
2464 
2465 	if (argc != 1)
2466 		return (DCMD_USAGE);
2467 
2468 	if (argv[0].a_type == MDB_TYPE_STRING)
2469 		attr_id = mdb_strtoull(argv[0].a_un.a_str);
2470 	else
2471 		return (DCMD_USAGE);
2472 
2473 	if (GETMEMB(addr, "sa_handle", sa_bonus_tab, bonus_tab) ||
2474 	    GETMEMB(addr, "sa_handle", sa_spill_tab, spill_tab) ||
2475 	    GETMEMB(addr, "sa_handle", sa_os, os) ||
2476 	    GETMEMB(addr, "sa_handle", sa_bonus, db_bonus) ||
2477 	    GETMEMB(addr, "sa_handle", sa_spill, db_spill)) {
2478 		mdb_printf("Can't find necessary information in sa_handle "
2479 		    "in sa_handle\n");
2480 		return (DCMD_ERR);
2481 	}
2482 
2483 	if (GETMEMB(os, "objset", os_sa, os_sa)) {
2484 		mdb_printf("Can't find os_sa in objset\n");
2485 		return (DCMD_ERR);
2486 	}
2487 
2488 	if (GETMEMB(os_sa, "sa_os", sa_num_attrs, attr_count)) {
2489 		mdb_printf("Can't find sa_num_attrs\n");
2490 		return (DCMD_ERR);
2491 	}
2492 
2493 	if (attr_id > attr_count) {
2494 		mdb_printf("attribute id number is out of range\n");
2495 		return (DCMD_ERR);
2496 	}
2497 
2498 	if (bonus_tab) {
2499 		if (sa_get_off_table(bonus_tab, &offset_tab,
2500 		    attr_count) == -1) {
2501 			return (DCMD_ERR);
2502 		}
2503 
2504 		if (GETMEMB(db_bonus, "dmu_buf", db_data, db_data)) {
2505 			mdb_printf("can't find db_data in bonus dbuf\n");
2506 			return (DCMD_ERR);
2507 		}
2508 	}
2509 
2510 	if (bonus_tab && !TOC_ATTR_PRESENT(offset_tab[attr_id]) &&
2511 	    spill_tab == NULL) {
2512 		mdb_printf("Attribute does not exist\n");
2513 		return (DCMD_ERR);
2514 	} else if (!TOC_ATTR_PRESENT(offset_tab[attr_id]) && spill_tab) {
2515 		if (sa_get_off_table(spill_tab, &offset_tab,
2516 		    attr_count) == -1) {
2517 			return (DCMD_ERR);
2518 		}
2519 		if (GETMEMB(db_spill, "dmu_buf", db_data, db_data)) {
2520 			mdb_printf("can't find db_data in spill dbuf\n");
2521 			return (DCMD_ERR);
2522 		}
2523 		if (!TOC_ATTR_PRESENT(offset_tab[attr_id])) {
2524 			mdb_printf("Attribute does not exist\n");
2525 			return (DCMD_ERR);
2526 		}
2527 	}
2528 	attr_addr = db_data + TOC_OFF(offset_tab[attr_id]);
2529 	mdb_printf("%p\n", attr_addr);
2530 	return (DCMD_OK);
2531 }
2532 
2533 /* ARGSUSED */
2534 static int
2535 zfs_ace_print_common(uintptr_t addr, uint_t flags,
2536     uint64_t id, uint32_t access_mask, uint16_t ace_flags,
2537     uint16_t ace_type, int verbose)
2538 {
2539 	if (DCMD_HDRSPEC(flags) && !verbose)
2540 		mdb_printf("%<u>%-?s %-8s %-8s %-8s %s%</u>\n",
2541 		    "ADDR", "FLAGS", "MASK", "TYPE", "ID");
2542 
2543 	if (!verbose) {
2544 		mdb_printf("%0?p %-8x %-8x %-8x %-llx\n", addr,
2545 		    ace_flags, access_mask, ace_type, id);
2546 		return (DCMD_OK);
2547 	}
2548 
2549 	switch (ace_flags & ACE_TYPE_FLAGS) {
2550 	case ACE_OWNER:
2551 		mdb_printf("owner@:");
2552 		break;
2553 	case (ACE_IDENTIFIER_GROUP | ACE_GROUP):
2554 		mdb_printf("group@:");
2555 		break;
2556 	case ACE_EVERYONE:
2557 		mdb_printf("everyone@:");
2558 		break;
2559 	case ACE_IDENTIFIER_GROUP:
2560 		mdb_printf("group:%llx:", (u_longlong_t)id);
2561 		break;
2562 	case 0: /* User entry */
2563 		mdb_printf("user:%llx:", (u_longlong_t)id);
2564 		break;
2565 	}
2566 
2567 	/* print out permission mask */
2568 	if (access_mask & ACE_READ_DATA)
2569 		mdb_printf("r");
2570 	else
2571 		mdb_printf("-");
2572 	if (access_mask & ACE_WRITE_DATA)
2573 		mdb_printf("w");
2574 	else
2575 		mdb_printf("-");
2576 	if (access_mask & ACE_EXECUTE)
2577 		mdb_printf("x");
2578 	else
2579 		mdb_printf("-");
2580 	if (access_mask & ACE_APPEND_DATA)
2581 		mdb_printf("p");
2582 	else
2583 		mdb_printf("-");
2584 	if (access_mask & ACE_DELETE)
2585 		mdb_printf("d");
2586 	else
2587 		mdb_printf("-");
2588 	if (access_mask & ACE_DELETE_CHILD)
2589 		mdb_printf("D");
2590 	else
2591 		mdb_printf("-");
2592 	if (access_mask & ACE_READ_ATTRIBUTES)
2593 		mdb_printf("a");
2594 	else
2595 		mdb_printf("-");
2596 	if (access_mask & ACE_WRITE_ATTRIBUTES)
2597 		mdb_printf("A");
2598 	else
2599 		mdb_printf("-");
2600 	if (access_mask & ACE_READ_NAMED_ATTRS)
2601 		mdb_printf("R");
2602 	else
2603 		mdb_printf("-");
2604 	if (access_mask & ACE_WRITE_NAMED_ATTRS)
2605 		mdb_printf("W");
2606 	else
2607 		mdb_printf("-");
2608 	if (access_mask & ACE_READ_ACL)
2609 		mdb_printf("c");
2610 	else
2611 		mdb_printf("-");
2612 	if (access_mask & ACE_WRITE_ACL)
2613 		mdb_printf("C");
2614 	else
2615 		mdb_printf("-");
2616 	if (access_mask & ACE_WRITE_OWNER)
2617 		mdb_printf("o");
2618 	else
2619 		mdb_printf("-");
2620 	if (access_mask & ACE_SYNCHRONIZE)
2621 		mdb_printf("s");
2622 	else
2623 		mdb_printf("-");
2624 
2625 	mdb_printf(":");
2626 
2627 	/* Print out inheritance flags */
2628 	if (ace_flags & ACE_FILE_INHERIT_ACE)
2629 		mdb_printf("f");
2630 	else
2631 		mdb_printf("-");
2632 	if (ace_flags & ACE_DIRECTORY_INHERIT_ACE)
2633 		mdb_printf("d");
2634 	else
2635 		mdb_printf("-");
2636 	if (ace_flags & ACE_INHERIT_ONLY_ACE)
2637 		mdb_printf("i");
2638 	else
2639 		mdb_printf("-");
2640 	if (ace_flags & ACE_NO_PROPAGATE_INHERIT_ACE)
2641 		mdb_printf("n");
2642 	else
2643 		mdb_printf("-");
2644 	if (ace_flags & ACE_SUCCESSFUL_ACCESS_ACE_FLAG)
2645 		mdb_printf("S");
2646 	else
2647 		mdb_printf("-");
2648 	if (ace_flags & ACE_FAILED_ACCESS_ACE_FLAG)
2649 		mdb_printf("F");
2650 	else
2651 		mdb_printf("-");
2652 	if (ace_flags & ACE_INHERITED_ACE)
2653 		mdb_printf("I");
2654 	else
2655 		mdb_printf("-");
2656 
2657 	switch (ace_type) {
2658 	case ACE_ACCESS_ALLOWED_ACE_TYPE:
2659 		mdb_printf(":allow\n");
2660 		break;
2661 	case ACE_ACCESS_DENIED_ACE_TYPE:
2662 		mdb_printf(":deny\n");
2663 		break;
2664 	case ACE_SYSTEM_AUDIT_ACE_TYPE:
2665 		mdb_printf(":audit\n");
2666 		break;
2667 	case ACE_SYSTEM_ALARM_ACE_TYPE:
2668 		mdb_printf(":alarm\n");
2669 		break;
2670 	default:
2671 		mdb_printf(":?\n");
2672 	}
2673 	return (DCMD_OK);
2674 }
2675 
2676 /* ARGSUSED */
2677 static int
2678 zfs_ace_print(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
2679 {
2680 	zfs_ace_t zace;
2681 	int verbose = FALSE;
2682 	uint64_t id;
2683 
2684 	if (!(flags & DCMD_ADDRSPEC))
2685 		return (DCMD_USAGE);
2686 
2687 	if (mdb_getopts(argc, argv,
2688 	    'v', MDB_OPT_SETBITS, TRUE, &verbose, TRUE, NULL) != argc)
2689 		return (DCMD_USAGE);
2690 
2691 	if (mdb_vread(&zace, sizeof (zfs_ace_t), addr) == -1) {
2692 		mdb_warn("failed to read zfs_ace_t");
2693 		return (DCMD_ERR);
2694 	}
2695 
2696 	if ((zace.z_hdr.z_flags & ACE_TYPE_FLAGS) == 0 ||
2697 	    (zace.z_hdr.z_flags & ACE_TYPE_FLAGS) == ACE_IDENTIFIER_GROUP)
2698 		id = zace.z_fuid;
2699 	else
2700 		id = -1;
2701 
2702 	return (zfs_ace_print_common(addr, flags, id, zace.z_hdr.z_access_mask,
2703 	    zace.z_hdr.z_flags, zace.z_hdr.z_type, verbose));
2704 }
2705 
2706 /* ARGSUSED */
2707 static int
2708 zfs_ace0_print(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
2709 {
2710 	ace_t ace;
2711 	uint64_t id;
2712 	int verbose = FALSE;
2713 
2714 	if (!(flags & DCMD_ADDRSPEC))
2715 		return (DCMD_USAGE);
2716 
2717 	if (mdb_getopts(argc, argv,
2718 	    'v', MDB_OPT_SETBITS, TRUE, &verbose, TRUE, NULL) != argc)
2719 		return (DCMD_USAGE);
2720 
2721 	if (mdb_vread(&ace, sizeof (ace_t), addr) == -1) {
2722 		mdb_warn("failed to read ace_t");
2723 		return (DCMD_ERR);
2724 	}
2725 
2726 	if ((ace.a_flags & ACE_TYPE_FLAGS) == 0 ||
2727 	    (ace.a_flags & ACE_TYPE_FLAGS) == ACE_IDENTIFIER_GROUP)
2728 		id = ace.a_who;
2729 	else
2730 		id = -1;
2731 
2732 	return (zfs_ace_print_common(addr, flags, id, ace.a_access_mask,
2733 	    ace.a_flags, ace.a_type, verbose));
2734 }
2735 
2736 typedef struct acl_dump_args {
2737 	int a_argc;
2738 	const mdb_arg_t *a_argv;
2739 	uint16_t a_version;
2740 	int a_flags;
2741 } acl_dump_args_t;
2742 
2743 /* ARGSUSED */
2744 static int
2745 acl_aces_cb(uintptr_t addr, const void *unknown, void *arg)
2746 {
2747 	acl_dump_args_t *acl_args = (acl_dump_args_t *)arg;
2748 
2749 	if (acl_args->a_version == 1) {
2750 		if (mdb_call_dcmd("zfs_ace", addr,
2751 		    DCMD_ADDRSPEC|acl_args->a_flags, acl_args->a_argc,
2752 		    acl_args->a_argv) != DCMD_OK) {
2753 			return (WALK_ERR);
2754 		}
2755 	} else {
2756 		if (mdb_call_dcmd("zfs_ace0", addr,
2757 		    DCMD_ADDRSPEC|acl_args->a_flags, acl_args->a_argc,
2758 		    acl_args->a_argv) != DCMD_OK) {
2759 			return (WALK_ERR);
2760 		}
2761 	}
2762 	acl_args->a_flags = DCMD_LOOP;
2763 	return (WALK_NEXT);
2764 }
2765 
2766 /* ARGSUSED */
2767 static int
2768 acl_cb(uintptr_t addr, const void *unknown, void *arg)
2769 {
2770 	acl_dump_args_t *acl_args = (acl_dump_args_t *)arg;
2771 
2772 	if (acl_args->a_version == 1) {
2773 		if (mdb_pwalk("zfs_acl_node_aces", acl_aces_cb,
2774 		    arg, addr) != 0) {
2775 			mdb_warn("can't walk ACEs");
2776 			return (DCMD_ERR);
2777 		}
2778 	} else {
2779 		if (mdb_pwalk("zfs_acl_node_aces0", acl_aces_cb,
2780 		    arg, addr) != 0) {
2781 			mdb_warn("can't walk ACEs");
2782 			return (DCMD_ERR);
2783 		}
2784 	}
2785 	return (WALK_NEXT);
2786 }
2787 
2788 /* ARGSUSED */
2789 static int
2790 zfs_acl_dump(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
2791 {
2792 	zfs_acl_t zacl;
2793 	int verbose = FALSE;
2794 	acl_dump_args_t acl_args;
2795 
2796 	if (!(flags & DCMD_ADDRSPEC))
2797 		return (DCMD_USAGE);
2798 
2799 	if (mdb_getopts(argc, argv,
2800 	    'v', MDB_OPT_SETBITS, TRUE, &verbose, TRUE, NULL) != argc)
2801 		return (DCMD_USAGE);
2802 
2803 	if (mdb_vread(&zacl, sizeof (zfs_acl_t), addr) == -1) {
2804 		mdb_warn("failed to read zfs_acl_t");
2805 		return (DCMD_ERR);
2806 	}
2807 
2808 	acl_args.a_argc = argc;
2809 	acl_args.a_argv = argv;
2810 	acl_args.a_version = zacl.z_version;
2811 	acl_args.a_flags = DCMD_LOOPFIRST;
2812 
2813 	if (mdb_pwalk("zfs_acl_node", acl_cb, &acl_args, addr) != 0) {
2814 		mdb_warn("can't walk ACL");
2815 		return (DCMD_ERR);
2816 	}
2817 
2818 	return (DCMD_OK);
2819 }
2820 
2821 /* ARGSUSED */
2822 static int
2823 zfs_acl_node_walk_init(mdb_walk_state_t *wsp)
2824 {
2825 	if (wsp->walk_addr == NULL) {
2826 		mdb_warn("must supply address of zfs_acl_node_t\n");
2827 		return (WALK_ERR);
2828 	}
2829 
2830 	wsp->walk_addr +=
2831 	    mdb_ctf_offsetof_by_name(ZFS_STRUCT "zfs_acl", "z_acl");
2832 
2833 	if (mdb_layered_walk("list", wsp) == -1) {
2834 		mdb_warn("failed to walk 'list'\n");
2835 		return (WALK_ERR);
2836 	}
2837 
2838 	return (WALK_NEXT);
2839 }
2840 
2841 static int
2842 zfs_acl_node_walk_step(mdb_walk_state_t *wsp)
2843 {
2844 	zfs_acl_node_t	aclnode;
2845 
2846 	if (mdb_vread(&aclnode, sizeof (zfs_acl_node_t),
2847 	    wsp->walk_addr) == -1) {
2848 		mdb_warn("failed to read zfs_acl_node at %p", wsp->walk_addr);
2849 		return (WALK_ERR);
2850 	}
2851 
2852 	return (wsp->walk_callback(wsp->walk_addr, &aclnode, wsp->walk_cbdata));
2853 }
2854 
2855 typedef struct ace_walk_data {
2856 	int		ace_count;
2857 	int		ace_version;
2858 } ace_walk_data_t;
2859 
2860 static int
2861 zfs_aces_walk_init_common(mdb_walk_state_t *wsp, int version,
2862     int ace_count, uintptr_t ace_data)
2863 {
2864 	ace_walk_data_t *ace_walk_data;
2865 
2866 	if (wsp->walk_addr == NULL) {
2867 		mdb_warn("must supply address of zfs_acl_node_t\n");
2868 		return (WALK_ERR);
2869 	}
2870 
2871 	ace_walk_data = mdb_alloc(sizeof (ace_walk_data_t), UM_SLEEP | UM_GC);
2872 
2873 	ace_walk_data->ace_count = ace_count;
2874 	ace_walk_data->ace_version = version;
2875 
2876 	wsp->walk_addr = ace_data;
2877 	wsp->walk_data = ace_walk_data;
2878 
2879 	return (WALK_NEXT);
2880 }
2881 
2882 static int
2883 zfs_acl_node_aces_walk_init_common(mdb_walk_state_t *wsp, int version)
2884 {
2885 	static int gotid;
2886 	static mdb_ctf_id_t acl_id;
2887 	int z_ace_count;
2888 	uintptr_t z_acldata;
2889 
2890 	if (!gotid) {
2891 		if (mdb_ctf_lookup_by_name("struct zfs_acl_node",
2892 		    &acl_id) == -1) {
2893 			mdb_warn("couldn't find struct zfs_acl_node");
2894 			return (DCMD_ERR);
2895 		}
2896 		gotid = TRUE;
2897 	}
2898 
2899 	if (GETMEMBID(wsp->walk_addr, &acl_id, z_ace_count, z_ace_count)) {
2900 		return (DCMD_ERR);
2901 	}
2902 	if (GETMEMBID(wsp->walk_addr, &acl_id, z_acldata, z_acldata)) {
2903 		return (DCMD_ERR);
2904 	}
2905 
2906 	return (zfs_aces_walk_init_common(wsp, version,
2907 	    z_ace_count, z_acldata));
2908 }
2909 
2910 /* ARGSUSED */
2911 static int
2912 zfs_acl_node_aces_walk_init(mdb_walk_state_t *wsp)
2913 {
2914 	return (zfs_acl_node_aces_walk_init_common(wsp, 1));
2915 }
2916 
2917 /* ARGSUSED */
2918 static int
2919 zfs_acl_node_aces0_walk_init(mdb_walk_state_t *wsp)
2920 {
2921 	return (zfs_acl_node_aces_walk_init_common(wsp, 0));
2922 }
2923 
2924 static int
2925 zfs_aces_walk_step(mdb_walk_state_t *wsp)
2926 {
2927 	ace_walk_data_t *ace_data = wsp->walk_data;
2928 	zfs_ace_t zace;
2929 	ace_t *acep;
2930 	int status;
2931 	int entry_type;
2932 	int allow_type;
2933 	uintptr_t ptr;
2934 
2935 	if (ace_data->ace_count == 0)
2936 		return (WALK_DONE);
2937 
2938 	if (mdb_vread(&zace, sizeof (zfs_ace_t), wsp->walk_addr) == -1) {
2939 		mdb_warn("failed to read zfs_ace_t at %#lx",
2940 		    wsp->walk_addr);
2941 		return (WALK_ERR);
2942 	}
2943 
2944 	switch (ace_data->ace_version) {
2945 	case 0:
2946 		acep = (ace_t *)&zace;
2947 		entry_type = acep->a_flags & ACE_TYPE_FLAGS;
2948 		allow_type = acep->a_type;
2949 		break;
2950 	case 1:
2951 		entry_type = zace.z_hdr.z_flags & ACE_TYPE_FLAGS;
2952 		allow_type = zace.z_hdr.z_type;
2953 		break;
2954 	default:
2955 		return (WALK_ERR);
2956 	}
2957 
2958 	ptr = (uintptr_t)wsp->walk_addr;
2959 	switch (entry_type) {
2960 	case ACE_OWNER:
2961 	case ACE_EVERYONE:
2962 	case (ACE_IDENTIFIER_GROUP | ACE_GROUP):
2963 		ptr += ace_data->ace_version == 0 ?
2964 		    sizeof (ace_t) : sizeof (zfs_ace_hdr_t);
2965 		break;
2966 	case ACE_IDENTIFIER_GROUP:
2967 	default:
2968 		switch (allow_type) {
2969 		case ACE_ACCESS_ALLOWED_OBJECT_ACE_TYPE:
2970 		case ACE_ACCESS_DENIED_OBJECT_ACE_TYPE:
2971 		case ACE_SYSTEM_AUDIT_OBJECT_ACE_TYPE:
2972 		case ACE_SYSTEM_ALARM_OBJECT_ACE_TYPE:
2973 			ptr += ace_data->ace_version == 0 ?
2974 			    sizeof (ace_t) : sizeof (zfs_object_ace_t);
2975 			break;
2976 		default:
2977 			ptr += ace_data->ace_version == 0 ?
2978 			    sizeof (ace_t) : sizeof (zfs_ace_t);
2979 			break;
2980 		}
2981 	}
2982 
2983 	ace_data->ace_count--;
2984 	status = wsp->walk_callback(wsp->walk_addr,
2985 	    (void *)(uintptr_t)&zace, wsp->walk_cbdata);
2986 
2987 	wsp->walk_addr = ptr;
2988 	return (status);
2989 }
2990 
2991 typedef struct mdb_zfs_rrwlock {
2992 	uintptr_t	rr_writer;
2993 	boolean_t	rr_writer_wanted;
2994 } mdb_zfs_rrwlock_t;
2995 
2996 static uint_t rrw_key;
2997 
2998 /* ARGSUSED */
2999 static int
3000 rrwlock(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
3001 {
3002 	mdb_zfs_rrwlock_t rrw;
3003 
3004 	if (rrw_key == 0) {
3005 		if (mdb_ctf_readsym(&rrw_key, "uint_t", "rrw_tsd_key", 0) == -1)
3006 			return (DCMD_ERR);
3007 	}
3008 
3009 	if (mdb_ctf_vread(&rrw, "rrwlock_t", "mdb_zfs_rrwlock_t", addr,
3010 	    0) == -1)
3011 		return (DCMD_ERR);
3012 
3013 	if (rrw.rr_writer != 0) {
3014 		mdb_printf("write lock held by thread %lx\n", rrw.rr_writer);
3015 		return (DCMD_OK);
3016 	}
3017 
3018 	if (rrw.rr_writer_wanted) {
3019 		mdb_printf("writer wanted\n");
3020 	}
3021 
3022 	mdb_printf("anonymous references:\n");
3023 	(void) mdb_call_dcmd("refcount", addr +
3024 	    mdb_ctf_offsetof_by_name(ZFS_STRUCT "rrwlock", "rr_anon_rcount"),
3025 	    DCMD_ADDRSPEC, 0, NULL);
3026 
3027 	mdb_printf("linked references:\n");
3028 	(void) mdb_call_dcmd("refcount", addr +
3029 	    mdb_ctf_offsetof_by_name(ZFS_STRUCT "rrwlock", "rr_linked_rcount"),
3030 	    DCMD_ADDRSPEC, 0, NULL);
3031 
3032 	/*
3033 	 * XXX This should find references from
3034 	 * "::walk thread | ::tsd -v <rrw_key>", but there is no support
3035 	 * for programmatic consumption of dcmds, so this would be
3036 	 * difficult, potentially requiring reimplementing ::tsd (both
3037 	 * user and kernel versions) in this MDB module.
3038 	 */
3039 
3040 	return (DCMD_OK);
3041 }
3042 
3043 /*
3044  * MDB module linkage information:
3045  *
3046  * We declare a list of structures describing our dcmds, and a function
3047  * named _mdb_init to return a pointer to our module information.
3048  */
3049 
3050 static const mdb_dcmd_t dcmds[] = {
3051 	{ "arc", "[-bkmg]", "print ARC variables", arc_print },
3052 	{ "blkptr", ":", "print blkptr_t", blkptr },
3053 	{ "dbuf", ":", "print dmu_buf_impl_t", dbuf },
3054 	{ "dbuf_stats", ":", "dbuf stats", dbuf_stats },
3055 	{ "dbufs",
3056 	    "\t[-O objset_t*] [-n objset_name | \"mos\"] "
3057 	    "[-o object | \"mdn\"] \n"
3058 	    "\t[-l level] [-b blkid | \"bonus\"]",
3059 	    "find dmu_buf_impl_t's that match specified criteria", dbufs },
3060 	{ "abuf_find", "dva_word[0] dva_word[1]",
3061 	    "find arc_buf_hdr_t of a specified DVA",
3062 	    abuf_find },
3063 	{ "spa", "?[-cv]", "spa_t summary", spa_print },
3064 	{ "spa_config", ":", "print spa_t configuration", spa_print_config },
3065 	{ "spa_space", ":[-b]", "print spa_t on-disk space usage", spa_space },
3066 	{ "spa_vdevs", ":", "given a spa_t, print vdev summary", spa_vdevs },
3067 	{ "vdev", ":[-re]\n"
3068 	    "\t-r display recursively\n"
3069 	    "\t-e print statistics",
3070 	    "vdev_t summary", vdev_print },
3071 	{ "zio", ":[cpr]\n"
3072 	    "\t-c display children\n"
3073 	    "\t-p display parents\n"
3074 	    "\t-r display recursively",
3075 	    "zio_t summary", zio_print },
3076 	{ "zio_state", "?", "print out all zio_t structures on system or "
3077 	    "for a particular pool", zio_state },
3078 	{ "zfs_blkstats", ":[-v]",
3079 	    "given a spa_t, print block type stats from last scrub",
3080 	    zfs_blkstats },
3081 	{ "zfs_params", "", "print zfs tunable parameters", zfs_params },
3082 	{ "refcount", ":[-r]\n"
3083 	    "\t-r display recently removed references",
3084 	    "print refcount_t holders", refcount },
3085 	{ "zap_leaf", "", "print zap_leaf_phys_t", zap_leaf },
3086 	{ "zfs_aces", ":[-v]", "print all ACEs from a zfs_acl_t",
3087 	    zfs_acl_dump },
3088 	{ "zfs_ace", ":[-v]", "print zfs_ace", zfs_ace_print },
3089 	{ "zfs_ace0", ":[-v]", "print zfs_ace0", zfs_ace0_print },
3090 	{ "sa_attr_table", ":", "print SA attribute table from sa_os_t",
3091 	    sa_attr_table},
3092 	{ "sa_attr", ": attr_id",
3093 	    "print SA attribute address when given sa_handle_t", sa_attr_print},
3094 	{ "zfs_dbgmsg", ":[-va]",
3095 	    "print zfs debug log", dbgmsg},
3096 	{ "rrwlock", ":",
3097 	    "print rrwlock_t, including readers", rrwlock},
3098 	{ NULL }
3099 };
3100 
3101 static const mdb_walker_t walkers[] = {
3102 	{ "zms_freelist", "walk ZFS metaslab freelist",
3103 	    freelist_walk_init, freelist_walk_step, NULL },
3104 	{ "txg_list", "given any txg_list_t *, walk all entries in all txgs",
3105 	    txg_list_walk_init, txg_list_walk_step, NULL },
3106 	{ "txg_list0", "given any txg_list_t *, walk all entries in txg 0",
3107 	    txg_list0_walk_init, txg_list_walk_step, NULL },
3108 	{ "txg_list1", "given any txg_list_t *, walk all entries in txg 1",
3109 	    txg_list1_walk_init, txg_list_walk_step, NULL },
3110 	{ "txg_list2", "given any txg_list_t *, walk all entries in txg 2",
3111 	    txg_list2_walk_init, txg_list_walk_step, NULL },
3112 	{ "txg_list3", "given any txg_list_t *, walk all entries in txg 3",
3113 	    txg_list3_walk_init, txg_list_walk_step, NULL },
3114 	{ "zio", "walk all zio structures, optionally for a particular spa_t",
3115 	    zio_walk_init, zio_walk_step, NULL },
3116 	{ "zio_root",
3117 	    "walk all root zio_t structures, optionally for a particular spa_t",
3118 	    zio_walk_init, zio_walk_root_step, NULL },
3119 	{ "spa", "walk all spa_t entries in the namespace",
3120 	    spa_walk_init, spa_walk_step, NULL },
3121 	{ "metaslab", "given a spa_t *, walk all metaslab_t structures",
3122 	    metaslab_walk_init, metaslab_walk_step, NULL },
3123 	{ "zfs_acl_node", "given a zfs_acl_t, walk all zfs_acl_nodes",
3124 	    zfs_acl_node_walk_init, zfs_acl_node_walk_step, NULL },
3125 	{ "zfs_acl_node_aces", "given a zfs_acl_node_t, walk all ACEs",
3126 	    zfs_acl_node_aces_walk_init, zfs_aces_walk_step, NULL },
3127 	{ "zfs_acl_node_aces0",
3128 	    "given a zfs_acl_node_t, walk all ACEs as ace_t",
3129 	    zfs_acl_node_aces0_walk_init, zfs_aces_walk_step, NULL },
3130 	{ NULL }
3131 };
3132 
3133 static const mdb_modinfo_t modinfo = {
3134 	MDB_API_VERSION, dcmds, walkers
3135 };
3136 
3137 const mdb_modinfo_t *
3138 _mdb_init(void)
3139 {
3140 	return (&modinfo);
3141 }
3142