1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21 /*
22 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
23 * Copyright (c) 2012 by Delphix. All rights reserved.
24 */
25
26 #include <sys/zio.h>
27 #include <sys/spa.h>
28 #include <sys/dmu.h>
29 #include <sys/zfs_context.h>
30 #include <sys/zap.h>
31 #include <sys/refcount.h>
32 #include <sys/zap_impl.h>
33 #include <sys/zap_leaf.h>
34 #include <sys/avl.h>
35 #include <sys/arc.h>
36
37 #ifdef _KERNEL
38 #include <sys/sunddi.h>
39 #endif
40
41 static int mzap_upgrade(zap_t **zapp, dmu_tx_t *tx, zap_flags_t flags);
42
43 uint64_t
44 zap_getflags(zap_t *zap)
45 {
46 if (zap->zap_ismicro)
47 return (0);
48 return (zap->zap_u.zap_fat.zap_phys->zap_flags);
49 }
50
51 int
52 zap_hashbits(zap_t *zap)
53 {
54 if (zap_getflags(zap) & ZAP_FLAG_HASH64)
55 return (48);
56 else
57 return (28);
58 }
59
60 uint32_t
61 zap_maxcd(zap_t *zap)
62 {
63 if (zap_getflags(zap) & ZAP_FLAG_HASH64)
64 return ((1<<16)-1);
65 else
66 return (-1U);
67 }
68
69 static uint64_t
70 zap_hash(zap_name_t *zn)
71 {
72 zap_t *zap = zn->zn_zap;
73 uint64_t h = 0;
74
75 if (zap_getflags(zap) & ZAP_FLAG_PRE_HASHED_KEY) {
76 ASSERT(zap_getflags(zap) & ZAP_FLAG_UINT64_KEY);
77 h = *(uint64_t *)zn->zn_key_orig;
78 } else {
79 h = zap->zap_salt;
80 ASSERT(h != 0);
81 ASSERT(zfs_crc64_table[128] == ZFS_CRC64_POLY);
82
83 if (zap_getflags(zap) & ZAP_FLAG_UINT64_KEY) {
84 int i;
85 const uint64_t *wp = zn->zn_key_norm;
86
87 ASSERT(zn->zn_key_intlen == 8);
88 for (i = 0; i < zn->zn_key_norm_numints; wp++, i++) {
89 int j;
90 uint64_t word = *wp;
91
92 for (j = 0; j < zn->zn_key_intlen; j++) {
93 h = (h >> 8) ^
94 zfs_crc64_table[(h ^ word) & 0xFF];
95 word >>= NBBY;
96 }
97 }
98 } else {
99 int i, len;
100 const uint8_t *cp = zn->zn_key_norm;
101
102 /*
103 * We previously stored the terminating null on
104 * disk, but didn't hash it, so we need to
105 * continue to not hash it. (The
106 * zn_key_*_numints includes the terminating
107 * null for non-binary keys.)
108 */
109 len = zn->zn_key_norm_numints - 1;
110
111 ASSERT(zn->zn_key_intlen == 1);
112 for (i = 0; i < len; cp++, i++) {
113 h = (h >> 8) ^
114 zfs_crc64_table[(h ^ *cp) & 0xFF];
115 }
116 }
117 }
118 /*
119 * Don't use all 64 bits, since we need some in the cookie for
120 * the collision differentiator. We MUST use the high bits,
121 * since those are the ones that we first pay attention to when
122 * chosing the bucket.
123 */
124 h &= ~((1ULL << (64 - zap_hashbits(zap))) - 1);
125
126 return (h);
127 }
128
129 static int
130 zap_normalize(zap_t *zap, const char *name, char *namenorm)
131 {
132 size_t inlen, outlen;
133 int err;
134
135 ASSERT(!(zap_getflags(zap) & ZAP_FLAG_UINT64_KEY));
136
137 inlen = strlen(name) + 1;
138 outlen = ZAP_MAXNAMELEN;
139
140 err = 0;
141 (void) u8_textprep_str((char *)name, &inlen, namenorm, &outlen,
142 zap->zap_normflags | U8_TEXTPREP_IGNORE_NULL |
143 U8_TEXTPREP_IGNORE_INVALID, U8_UNICODE_LATEST, &err);
144
145 return (err);
146 }
147
148 boolean_t
149 zap_match(zap_name_t *zn, const char *matchname)
150 {
151 ASSERT(!(zap_getflags(zn->zn_zap) & ZAP_FLAG_UINT64_KEY));
152
153 if (zn->zn_matchtype == MT_FIRST) {
154 char norm[ZAP_MAXNAMELEN];
155
156 if (zap_normalize(zn->zn_zap, matchname, norm) != 0)
157 return (B_FALSE);
158
159 return (strcmp(zn->zn_key_norm, norm) == 0);
160 } else {
161 /* MT_BEST or MT_EXACT */
162 return (strcmp(zn->zn_key_orig, matchname) == 0);
163 }
164 }
165
166 void
167 zap_name_free(zap_name_t *zn)
168 {
169 kmem_free(zn, sizeof (zap_name_t));
170 }
171
172 zap_name_t *
173 zap_name_alloc(zap_t *zap, const char *key, matchtype_t mt)
174 {
175 zap_name_t *zn = kmem_alloc(sizeof (zap_name_t), KM_SLEEP);
176
177 zn->zn_zap = zap;
178 zn->zn_key_intlen = sizeof (*key);
179 zn->zn_key_orig = key;
180 zn->zn_key_orig_numints = strlen(zn->zn_key_orig) + 1;
181 zn->zn_matchtype = mt;
182 if (zap->zap_normflags) {
183 if (zap_normalize(zap, key, zn->zn_normbuf) != 0) {
184 zap_name_free(zn);
185 return (NULL);
186 }
187 zn->zn_key_norm = zn->zn_normbuf;
188 zn->zn_key_norm_numints = strlen(zn->zn_key_norm) + 1;
189 } else {
190 if (mt != MT_EXACT) {
191 zap_name_free(zn);
192 return (NULL);
193 }
194 zn->zn_key_norm = zn->zn_key_orig;
195 zn->zn_key_norm_numints = zn->zn_key_orig_numints;
196 }
197
198 zn->zn_hash = zap_hash(zn);
199 return (zn);
200 }
201
202 zap_name_t *
203 zap_name_alloc_uint64(zap_t *zap, const uint64_t *key, int numints)
204 {
205 zap_name_t *zn = kmem_alloc(sizeof (zap_name_t), KM_SLEEP);
206
207 ASSERT(zap->zap_normflags == 0);
208 zn->zn_zap = zap;
209 zn->zn_key_intlen = sizeof (*key);
210 zn->zn_key_orig = zn->zn_key_norm = key;
211 zn->zn_key_orig_numints = zn->zn_key_norm_numints = numints;
212 zn->zn_matchtype = MT_EXACT;
213
214 zn->zn_hash = zap_hash(zn);
215 return (zn);
216 }
217
218 static void
219 mzap_byteswap(mzap_phys_t *buf, size_t size)
220 {
221 int i, max;
222 buf->mz_block_type = BSWAP_64(buf->mz_block_type);
223 buf->mz_salt = BSWAP_64(buf->mz_salt);
224 buf->mz_normflags = BSWAP_64(buf->mz_normflags);
225 max = (size / MZAP_ENT_LEN) - 1;
226 for (i = 0; i < max; i++) {
227 buf->mz_chunk[i].mze_value =
228 BSWAP_64(buf->mz_chunk[i].mze_value);
229 buf->mz_chunk[i].mze_cd =
230 BSWAP_32(buf->mz_chunk[i].mze_cd);
231 }
232 }
233
234 void
235 zap_byteswap(void *buf, size_t size)
236 {
237 uint64_t block_type;
238
239 block_type = *(uint64_t *)buf;
240
241 if (block_type == ZBT_MICRO || block_type == BSWAP_64(ZBT_MICRO)) {
242 /* ASSERT(magic == ZAP_LEAF_MAGIC); */
243 mzap_byteswap(buf, size);
244 } else {
245 fzap_byteswap(buf, size);
246 }
247 }
248
249 static int
250 mze_compare(const void *arg1, const void *arg2)
251 {
252 const mzap_ent_t *mze1 = arg1;
253 const mzap_ent_t *mze2 = arg2;
254
255 if (mze1->mze_hash > mze2->mze_hash)
256 return (+1);
257 if (mze1->mze_hash < mze2->mze_hash)
258 return (-1);
259 if (mze1->mze_cd > mze2->mze_cd)
260 return (+1);
261 if (mze1->mze_cd < mze2->mze_cd)
262 return (-1);
263 return (0);
264 }
265
266 static void
267 mze_insert(zap_t *zap, int chunkid, uint64_t hash)
268 {
269 mzap_ent_t *mze;
270
271 ASSERT(zap->zap_ismicro);
272 ASSERT(RW_WRITE_HELD(&zap->zap_rwlock));
273
274 mze = kmem_alloc(sizeof (mzap_ent_t), KM_SLEEP);
275 mze->mze_chunkid = chunkid;
276 mze->mze_hash = hash;
277 mze->mze_cd = MZE_PHYS(zap, mze)->mze_cd;
278 ASSERT(MZE_PHYS(zap, mze)->mze_name[0] != 0);
279 avl_add(&zap->zap_m.zap_avl, mze);
280 }
281
282 static mzap_ent_t *
283 mze_find(zap_name_t *zn)
284 {
285 mzap_ent_t mze_tofind;
286 mzap_ent_t *mze;
287 avl_index_t idx;
288 avl_tree_t *avl = &zn->zn_zap->zap_m.zap_avl;
289
290 ASSERT(zn->zn_zap->zap_ismicro);
291 ASSERT(RW_LOCK_HELD(&zn->zn_zap->zap_rwlock));
292
293 mze_tofind.mze_hash = zn->zn_hash;
294 mze_tofind.mze_cd = 0;
295
296 again:
297 mze = avl_find(avl, &mze_tofind, &idx);
298 if (mze == NULL)
299 mze = avl_nearest(avl, idx, AVL_AFTER);
300 for (; mze && mze->mze_hash == zn->zn_hash; mze = AVL_NEXT(avl, mze)) {
301 ASSERT3U(mze->mze_cd, ==, MZE_PHYS(zn->zn_zap, mze)->mze_cd);
302 if (zap_match(zn, MZE_PHYS(zn->zn_zap, mze)->mze_name))
303 return (mze);
304 }
305 if (zn->zn_matchtype == MT_BEST) {
306 zn->zn_matchtype = MT_FIRST;
307 goto again;
308 }
309 return (NULL);
310 }
311
312 static uint32_t
313 mze_find_unused_cd(zap_t *zap, uint64_t hash)
314 {
315 mzap_ent_t mze_tofind;
316 mzap_ent_t *mze;
317 avl_index_t idx;
318 avl_tree_t *avl = &zap->zap_m.zap_avl;
319 uint32_t cd;
320
321 ASSERT(zap->zap_ismicro);
322 ASSERT(RW_LOCK_HELD(&zap->zap_rwlock));
323
324 mze_tofind.mze_hash = hash;
325 mze_tofind.mze_cd = 0;
326
327 cd = 0;
328 for (mze = avl_find(avl, &mze_tofind, &idx);
329 mze && mze->mze_hash == hash; mze = AVL_NEXT(avl, mze)) {
330 if (mze->mze_cd != cd)
331 break;
332 cd++;
333 }
334
335 return (cd);
336 }
337
338 static void
339 mze_remove(zap_t *zap, mzap_ent_t *mze)
340 {
341 ASSERT(zap->zap_ismicro);
342 ASSERT(RW_WRITE_HELD(&zap->zap_rwlock));
343
344 avl_remove(&zap->zap_m.zap_avl, mze);
345 kmem_free(mze, sizeof (mzap_ent_t));
346 }
347
348 static void
349 mze_destroy(zap_t *zap)
350 {
351 mzap_ent_t *mze;
352 void *avlcookie = NULL;
353
354 while (mze = avl_destroy_nodes(&zap->zap_m.zap_avl, &avlcookie))
355 kmem_free(mze, sizeof (mzap_ent_t));
356 avl_destroy(&zap->zap_m.zap_avl);
357 }
358
359 static zap_t *
360 mzap_open(objset_t *os, uint64_t obj, dmu_buf_t *db)
361 {
362 zap_t *winner;
363 zap_t *zap;
364 int i;
365
366 ASSERT3U(MZAP_ENT_LEN, ==, sizeof (mzap_ent_phys_t));
367
368 zap = kmem_zalloc(sizeof (zap_t), KM_SLEEP);
369 rw_init(&zap->zap_rwlock, 0, 0, 0);
370 rw_enter(&zap->zap_rwlock, RW_WRITER);
371 zap->zap_objset = os;
372 zap->zap_object = obj;
373 zap->zap_dbuf = db;
374
375 if (*(uint64_t *)db->db_data != ZBT_MICRO) {
376 mutex_init(&zap->zap_f.zap_num_entries_mtx, 0, 0, 0);
377 zap->zap_f.zap_block_shift = highbit(db->db_size) - 1;
378 } else {
379 zap->zap_ismicro = TRUE;
380 }
381
382 /*
383 * Make sure that zap_ismicro is set before we let others see
384 * it, because zap_lockdir() checks zap_ismicro without the lock
385 * held.
386 */
387 winner = dmu_buf_set_user(db, zap, &zap->zap_m.zap_phys, zap_evict);
388
389 if (winner != NULL) {
390 rw_exit(&zap->zap_rwlock);
391 rw_destroy(&zap->zap_rwlock);
392 if (!zap->zap_ismicro)
393 mutex_destroy(&zap->zap_f.zap_num_entries_mtx);
394 kmem_free(zap, sizeof (zap_t));
395 return (winner);
396 }
397
398 if (zap->zap_ismicro) {
399 zap->zap_salt = zap->zap_m.zap_phys->mz_salt;
400 zap->zap_normflags = zap->zap_m.zap_phys->mz_normflags;
401 zap->zap_m.zap_num_chunks = db->db_size / MZAP_ENT_LEN - 1;
402 avl_create(&zap->zap_m.zap_avl, mze_compare,
403 sizeof (mzap_ent_t), offsetof(mzap_ent_t, mze_node));
404
405 for (i = 0; i < zap->zap_m.zap_num_chunks; i++) {
406 mzap_ent_phys_t *mze =
407 &zap->zap_m.zap_phys->mz_chunk[i];
408 if (mze->mze_name[0]) {
409 zap_name_t *zn;
410
411 zap->zap_m.zap_num_entries++;
412 zn = zap_name_alloc(zap, mze->mze_name,
413 MT_EXACT);
414 mze_insert(zap, i, zn->zn_hash);
415 zap_name_free(zn);
416 }
417 }
418 } else {
419 zap->zap_salt = zap->zap_f.zap_phys->zap_salt;
420 zap->zap_normflags = zap->zap_f.zap_phys->zap_normflags;
421
422 ASSERT3U(sizeof (struct zap_leaf_header), ==,
423 2*ZAP_LEAF_CHUNKSIZE);
424
425 /*
426 * The embedded pointer table should not overlap the
427 * other members.
428 */
429 ASSERT3P(&ZAP_EMBEDDED_PTRTBL_ENT(zap, 0), >,
430 &zap->zap_f.zap_phys->zap_salt);
431
432 /*
433 * The embedded pointer table should end at the end of
434 * the block
435 */
436 ASSERT3U((uintptr_t)&ZAP_EMBEDDED_PTRTBL_ENT(zap,
437 1<<ZAP_EMBEDDED_PTRTBL_SHIFT(zap)) -
438 (uintptr_t)zap->zap_f.zap_phys, ==,
439 zap->zap_dbuf->db_size);
440 }
441 rw_exit(&zap->zap_rwlock);
442 return (zap);
443 }
444
445 int
446 zap_lockdir(objset_t *os, uint64_t obj, dmu_tx_t *tx,
447 krw_t lti, boolean_t fatreader, boolean_t adding, zap_t **zapp)
448 {
449 zap_t *zap;
450 dmu_buf_t *db;
451 krw_t lt;
452 int err;
453
454 *zapp = NULL;
455
456 err = dmu_buf_hold(os, obj, 0, NULL, &db, DMU_READ_NO_PREFETCH);
457 if (err)
458 return (err);
459
460 #ifdef ZFS_DEBUG
461 {
462 dmu_object_info_t doi;
463 dmu_object_info_from_db(db, &doi);
464 ASSERT3U(DMU_OT_BYTESWAP(doi.doi_type), ==, DMU_BSWAP_ZAP);
465 }
466 #endif
467
468 zap = dmu_buf_get_user(db);
469 if (zap == NULL)
470 zap = mzap_open(os, obj, db);
471
472 /*
473 * We're checking zap_ismicro without the lock held, in order to
474 * tell what type of lock we want. Once we have some sort of
475 * lock, see if it really is the right type. In practice this
476 * can only be different if it was upgraded from micro to fat,
477 * and micro wanted WRITER but fat only needs READER.
478 */
479 lt = (!zap->zap_ismicro && fatreader) ? RW_READER : lti;
480 rw_enter(&zap->zap_rwlock, lt);
481 if (lt != ((!zap->zap_ismicro && fatreader) ? RW_READER : lti)) {
482 /* it was upgraded, now we only need reader */
483 ASSERT(lt == RW_WRITER);
484 ASSERT(RW_READER ==
485 (!zap->zap_ismicro && fatreader) ? RW_READER : lti);
486 rw_downgrade(&zap->zap_rwlock);
487 lt = RW_READER;
488 }
489
490 zap->zap_objset = os;
491
492 if (lt == RW_WRITER)
493 dmu_buf_will_dirty(db, tx);
494
495 ASSERT3P(zap->zap_dbuf, ==, db);
496
497 ASSERT(!zap->zap_ismicro ||
498 zap->zap_m.zap_num_entries <= zap->zap_m.zap_num_chunks);
499 if (zap->zap_ismicro && tx && adding &&
500 zap->zap_m.zap_num_entries == zap->zap_m.zap_num_chunks) {
501 uint64_t newsz = db->db_size + SPA_MINBLOCKSIZE;
502 if (newsz > MZAP_MAX_BLKSZ) {
503 dprintf("upgrading obj %llu: num_entries=%u\n",
504 obj, zap->zap_m.zap_num_entries);
505 *zapp = zap;
506 return (mzap_upgrade(zapp, tx, 0));
507 }
508 err = dmu_object_set_blocksize(os, obj, newsz, 0, tx);
509 ASSERT0(err);
510 zap->zap_m.zap_num_chunks =
511 db->db_size / MZAP_ENT_LEN - 1;
512 }
513
514 *zapp = zap;
515 return (0);
516 }
517
518 void
519 zap_unlockdir(zap_t *zap)
520 {
521 rw_exit(&zap->zap_rwlock);
522 dmu_buf_rele(zap->zap_dbuf, NULL);
523 }
524
525 static int
526 mzap_upgrade(zap_t **zapp, dmu_tx_t *tx, zap_flags_t flags)
527 {
528 mzap_phys_t *mzp;
529 int i, sz, nchunks;
530 int err = 0;
531 zap_t *zap = *zapp;
532
533 ASSERT(RW_WRITE_HELD(&zap->zap_rwlock));
534
535 sz = zap->zap_dbuf->db_size;
536 mzp = kmem_alloc(sz, KM_SLEEP);
537 bcopy(zap->zap_dbuf->db_data, mzp, sz);
538 nchunks = zap->zap_m.zap_num_chunks;
539
540 if (!flags) {
541 err = dmu_object_set_blocksize(zap->zap_objset, zap->zap_object,
542 1ULL << fzap_default_block_shift, 0, tx);
543 if (err) {
544 kmem_free(mzp, sz);
545 return (err);
546 }
547 }
548
549 dprintf("upgrading obj=%llu with %u chunks\n",
550 zap->zap_object, nchunks);
551 /* XXX destroy the avl later, so we can use the stored hash value */
552 mze_destroy(zap);
553
554 fzap_upgrade(zap, tx, flags);
555
556 for (i = 0; i < nchunks; i++) {
557 mzap_ent_phys_t *mze = &mzp->mz_chunk[i];
558 zap_name_t *zn;
559 if (mze->mze_name[0] == 0)
560 continue;
561 dprintf("adding %s=%llu\n",
562 mze->mze_name, mze->mze_value);
563 zn = zap_name_alloc(zap, mze->mze_name, MT_EXACT);
564 err = fzap_add_cd(zn, 8, 1, &mze->mze_value, mze->mze_cd, tx);
565 zap = zn->zn_zap; /* fzap_add_cd() may change zap */
566 zap_name_free(zn);
567 if (err)
568 break;
569 }
570 kmem_free(mzp, sz);
571 *zapp = zap;
572 return (err);
573 }
574
575 static void
576 mzap_create_impl(objset_t *os, uint64_t obj, int normflags, zap_flags_t flags,
577 dmu_tx_t *tx)
578 {
579 dmu_buf_t *db;
580 mzap_phys_t *zp;
581
582 VERIFY(0 == dmu_buf_hold(os, obj, 0, FTAG, &db, DMU_READ_NO_PREFETCH));
583
584 #ifdef ZFS_DEBUG
585 {
586 dmu_object_info_t doi;
587 dmu_object_info_from_db(db, &doi);
588 ASSERT3U(DMU_OT_BYTESWAP(doi.doi_type), ==, DMU_BSWAP_ZAP);
589 }
590 #endif
591
592 dmu_buf_will_dirty(db, tx);
593 zp = db->db_data;
594 zp->mz_block_type = ZBT_MICRO;
595 zp->mz_salt = ((uintptr_t)db ^ (uintptr_t)tx ^ (obj << 1)) | 1ULL;
596 zp->mz_normflags = normflags;
597 dmu_buf_rele(db, FTAG);
598
599 if (flags != 0) {
600 zap_t *zap;
601 /* Only fat zap supports flags; upgrade immediately. */
602 VERIFY(0 == zap_lockdir(os, obj, tx, RW_WRITER,
603 B_FALSE, B_FALSE, &zap));
604 VERIFY0(mzap_upgrade(&zap, tx, flags));
605 zap_unlockdir(zap);
606 }
607 }
608
609 int
610 zap_create_claim(objset_t *os, uint64_t obj, dmu_object_type_t ot,
611 dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx)
612 {
613 return (zap_create_claim_norm(os, obj,
614 0, ot, bonustype, bonuslen, tx));
615 }
616
617 int
618 zap_create_claim_norm(objset_t *os, uint64_t obj, int normflags,
619 dmu_object_type_t ot,
620 dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx)
621 {
622 int err;
623
624 err = dmu_object_claim(os, obj, ot, 0, bonustype, bonuslen, tx);
625 if (err != 0)
626 return (err);
627 mzap_create_impl(os, obj, normflags, 0, tx);
628 return (0);
629 }
630
631 uint64_t
632 zap_create(objset_t *os, dmu_object_type_t ot,
633 dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx)
634 {
635 return (zap_create_norm(os, 0, ot, bonustype, bonuslen, tx));
636 }
637
638 uint64_t
639 zap_create_norm(objset_t *os, int normflags, dmu_object_type_t ot,
640 dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx)
641 {
642 uint64_t obj = dmu_object_alloc(os, ot, 0, bonustype, bonuslen, tx);
643
644 mzap_create_impl(os, obj, normflags, 0, tx);
645 return (obj);
646 }
647
648 uint64_t
649 zap_create_flags(objset_t *os, int normflags, zap_flags_t flags,
650 dmu_object_type_t ot, int leaf_blockshift, int indirect_blockshift,
651 dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx)
652 {
653 uint64_t obj = dmu_object_alloc(os, ot, 0, bonustype, bonuslen, tx);
654
655 ASSERT(leaf_blockshift >= SPA_MINBLOCKSHIFT &&
656 leaf_blockshift <= SPA_MAXBLOCKSHIFT &&
657 indirect_blockshift >= SPA_MINBLOCKSHIFT &&
658 indirect_blockshift <= SPA_MAXBLOCKSHIFT);
659
660 VERIFY(dmu_object_set_blocksize(os, obj,
661 1ULL << leaf_blockshift, indirect_blockshift, tx) == 0);
662
663 mzap_create_impl(os, obj, normflags, flags, tx);
664 return (obj);
665 }
666
667 int
668 zap_destroy(objset_t *os, uint64_t zapobj, dmu_tx_t *tx)
669 {
670 /*
671 * dmu_object_free will free the object number and free the
672 * data. Freeing the data will cause our pageout function to be
673 * called, which will destroy our data (zap_leaf_t's and zap_t).
674 */
675
676 return (dmu_object_free(os, zapobj, tx));
677 }
678
679 _NOTE(ARGSUSED(0))
680 void
681 zap_evict(dmu_buf_t *db, void *vzap)
682 {
683 zap_t *zap = vzap;
684
685 rw_destroy(&zap->zap_rwlock);
686
687 if (zap->zap_ismicro)
688 mze_destroy(zap);
689 else
690 mutex_destroy(&zap->zap_f.zap_num_entries_mtx);
691
692 kmem_free(zap, sizeof (zap_t));
693 }
694
695 int
696 zap_count(objset_t *os, uint64_t zapobj, uint64_t *count)
697 {
698 zap_t *zap;
699 int err;
700
701 err = zap_lockdir(os, zapobj, NULL, RW_READER, TRUE, FALSE, &zap);
702 if (err)
703 return (err);
704 if (!zap->zap_ismicro) {
705 err = fzap_count(zap, count);
706 } else {
707 *count = zap->zap_m.zap_num_entries;
708 }
709 zap_unlockdir(zap);
710 return (err);
711 }
712
713 /*
714 * zn may be NULL; if not specified, it will be computed if needed.
715 * See also the comment above zap_entry_normalization_conflict().
716 */
717 static boolean_t
718 mzap_normalization_conflict(zap_t *zap, zap_name_t *zn, mzap_ent_t *mze)
719 {
720 mzap_ent_t *other;
721 int direction = AVL_BEFORE;
722 boolean_t allocdzn = B_FALSE;
723
724 if (zap->zap_normflags == 0)
725 return (B_FALSE);
726
727 again:
728 for (other = avl_walk(&zap->zap_m.zap_avl, mze, direction);
729 other && other->mze_hash == mze->mze_hash;
730 other = avl_walk(&zap->zap_m.zap_avl, other, direction)) {
731
732 if (zn == NULL) {
733 zn = zap_name_alloc(zap, MZE_PHYS(zap, mze)->mze_name,
734 MT_FIRST);
735 allocdzn = B_TRUE;
736 }
737 if (zap_match(zn, MZE_PHYS(zap, other)->mze_name)) {
738 if (allocdzn)
739 zap_name_free(zn);
740 return (B_TRUE);
741 }
742 }
743
744 if (direction == AVL_BEFORE) {
745 direction = AVL_AFTER;
746 goto again;
747 }
748
749 if (allocdzn)
750 zap_name_free(zn);
751 return (B_FALSE);
752 }
753
754 /*
755 * Routines for manipulating attributes.
756 */
757
758 int
759 zap_lookup(objset_t *os, uint64_t zapobj, const char *name,
760 uint64_t integer_size, uint64_t num_integers, void *buf)
761 {
762 return (zap_lookup_norm(os, zapobj, name, integer_size,
763 num_integers, buf, MT_EXACT, NULL, 0, NULL));
764 }
765
766 int
767 zap_lookup_norm(objset_t *os, uint64_t zapobj, const char *name,
768 uint64_t integer_size, uint64_t num_integers, void *buf,
769 matchtype_t mt, char *realname, int rn_len,
770 boolean_t *ncp)
771 {
772 zap_t *zap;
773 int err;
774 mzap_ent_t *mze;
775 zap_name_t *zn;
776
777 err = zap_lockdir(os, zapobj, NULL, RW_READER, TRUE, FALSE, &zap);
778 if (err)
779 return (err);
780 zn = zap_name_alloc(zap, name, mt);
781 if (zn == NULL) {
782 zap_unlockdir(zap);
783 return (ENOTSUP);
784 }
785
786 if (!zap->zap_ismicro) {
787 err = fzap_lookup(zn, integer_size, num_integers, buf,
788 realname, rn_len, ncp);
789 } else {
790 mze = mze_find(zn);
791 if (mze == NULL) {
792 err = ENOENT;
793 } else {
794 if (num_integers < 1) {
795 err = EOVERFLOW;
796 } else if (integer_size != 8) {
797 err = EINVAL;
798 } else {
799 *(uint64_t *)buf =
800 MZE_PHYS(zap, mze)->mze_value;
801 (void) strlcpy(realname,
802 MZE_PHYS(zap, mze)->mze_name, rn_len);
803 if (ncp) {
804 *ncp = mzap_normalization_conflict(zap,
805 zn, mze);
806 }
807 }
808 }
809 }
810 zap_name_free(zn);
811 zap_unlockdir(zap);
812 return (err);
813 }
814
815 int
816 zap_prefetch_uint64(objset_t *os, uint64_t zapobj, const uint64_t *key,
817 int key_numints)
818 {
819 zap_t *zap;
820 int err;
821 zap_name_t *zn;
822
823 err = zap_lockdir(os, zapobj, NULL, RW_READER, TRUE, FALSE, &zap);
824 if (err)
825 return (err);
826 zn = zap_name_alloc_uint64(zap, key, key_numints);
827 if (zn == NULL) {
828 zap_unlockdir(zap);
829 return (ENOTSUP);
830 }
831
832 fzap_prefetch(zn);
833 zap_name_free(zn);
834 zap_unlockdir(zap);
835 return (err);
836 }
837
838 int
839 zap_lookup_uint64(objset_t *os, uint64_t zapobj, const uint64_t *key,
840 int key_numints, uint64_t integer_size, uint64_t num_integers, void *buf)
841 {
842 zap_t *zap;
843 int err;
844 zap_name_t *zn;
845
846 err = zap_lockdir(os, zapobj, NULL, RW_READER, TRUE, FALSE, &zap);
847 if (err)
848 return (err);
849 zn = zap_name_alloc_uint64(zap, key, key_numints);
850 if (zn == NULL) {
851 zap_unlockdir(zap);
852 return (ENOTSUP);
853 }
854
855 err = fzap_lookup(zn, integer_size, num_integers, buf,
856 NULL, 0, NULL);
857 zap_name_free(zn);
858 zap_unlockdir(zap);
859 return (err);
860 }
861
862 int
863 zap_contains(objset_t *os, uint64_t zapobj, const char *name)
864 {
865 int err = (zap_lookup_norm(os, zapobj, name, 0,
866 0, NULL, MT_EXACT, NULL, 0, NULL));
867 if (err == EOVERFLOW || err == EINVAL)
868 err = 0; /* found, but skipped reading the value */
869 return (err);
870 }
871
872 int
873 zap_length(objset_t *os, uint64_t zapobj, const char *name,
874 uint64_t *integer_size, uint64_t *num_integers)
875 {
876 zap_t *zap;
877 int err;
878 mzap_ent_t *mze;
879 zap_name_t *zn;
880
881 err = zap_lockdir(os, zapobj, NULL, RW_READER, TRUE, FALSE, &zap);
882 if (err)
883 return (err);
884 zn = zap_name_alloc(zap, name, MT_EXACT);
885 if (zn == NULL) {
886 zap_unlockdir(zap);
887 return (ENOTSUP);
888 }
889 if (!zap->zap_ismicro) {
890 err = fzap_length(zn, integer_size, num_integers);
891 } else {
892 mze = mze_find(zn);
893 if (mze == NULL) {
894 err = ENOENT;
895 } else {
896 if (integer_size)
897 *integer_size = 8;
898 if (num_integers)
899 *num_integers = 1;
900 }
901 }
902 zap_name_free(zn);
903 zap_unlockdir(zap);
904 return (err);
905 }
906
907 int
908 zap_length_uint64(objset_t *os, uint64_t zapobj, const uint64_t *key,
909 int key_numints, uint64_t *integer_size, uint64_t *num_integers)
910 {
911 zap_t *zap;
912 int err;
913 zap_name_t *zn;
914
915 err = zap_lockdir(os, zapobj, NULL, RW_READER, TRUE, FALSE, &zap);
916 if (err)
917 return (err);
918 zn = zap_name_alloc_uint64(zap, key, key_numints);
919 if (zn == NULL) {
920 zap_unlockdir(zap);
921 return (ENOTSUP);
922 }
923 err = fzap_length(zn, integer_size, num_integers);
924 zap_name_free(zn);
925 zap_unlockdir(zap);
926 return (err);
927 }
928
929 static void
930 mzap_addent(zap_name_t *zn, uint64_t value)
931 {
932 int i;
933 zap_t *zap = zn->zn_zap;
934 int start = zap->zap_m.zap_alloc_next;
935 uint32_t cd;
936
937 ASSERT(RW_WRITE_HELD(&zap->zap_rwlock));
938
939 #ifdef ZFS_DEBUG
940 for (i = 0; i < zap->zap_m.zap_num_chunks; i++) {
941 mzap_ent_phys_t *mze = &zap->zap_m.zap_phys->mz_chunk[i];
942 ASSERT(strcmp(zn->zn_key_orig, mze->mze_name) != 0);
943 }
944 #endif
945
946 cd = mze_find_unused_cd(zap, zn->zn_hash);
947 /* given the limited size of the microzap, this can't happen */
948 ASSERT(cd < zap_maxcd(zap));
949
950 again:
951 for (i = start; i < zap->zap_m.zap_num_chunks; i++) {
952 mzap_ent_phys_t *mze = &zap->zap_m.zap_phys->mz_chunk[i];
953 if (mze->mze_name[0] == 0) {
954 mze->mze_value = value;
955 mze->mze_cd = cd;
956 (void) strcpy(mze->mze_name, zn->zn_key_orig);
957 zap->zap_m.zap_num_entries++;
958 zap->zap_m.zap_alloc_next = i+1;
959 if (zap->zap_m.zap_alloc_next ==
960 zap->zap_m.zap_num_chunks)
961 zap->zap_m.zap_alloc_next = 0;
962 mze_insert(zap, i, zn->zn_hash);
963 return;
964 }
965 }
966 if (start != 0) {
967 start = 0;
968 goto again;
969 }
970 ASSERT(!"out of entries!");
971 }
972
973 int
974 zap_add(objset_t *os, uint64_t zapobj, const char *key,
975 int integer_size, uint64_t num_integers,
976 const void *val, dmu_tx_t *tx)
977 {
978 zap_t *zap;
979 int err;
980 mzap_ent_t *mze;
981 const uint64_t *intval = val;
982 zap_name_t *zn;
983
984 err = zap_lockdir(os, zapobj, tx, RW_WRITER, TRUE, TRUE, &zap);
985 if (err)
986 return (err);
987 zn = zap_name_alloc(zap, key, MT_EXACT);
988 if (zn == NULL) {
989 zap_unlockdir(zap);
990 return (ENOTSUP);
991 }
992 if (!zap->zap_ismicro) {
993 err = fzap_add(zn, integer_size, num_integers, val, tx);
994 zap = zn->zn_zap; /* fzap_add() may change zap */
995 } else if (integer_size != 8 || num_integers != 1 ||
996 strlen(key) >= MZAP_NAME_LEN) {
997 err = mzap_upgrade(&zn->zn_zap, tx, 0);
998 if (err == 0)
999 err = fzap_add(zn, integer_size, num_integers, val, tx);
1000 zap = zn->zn_zap; /* fzap_add() may change zap */
1001 } else {
1002 mze = mze_find(zn);
1003 if (mze != NULL) {
1004 err = EEXIST;
1005 } else {
1006 mzap_addent(zn, *intval);
1007 }
1008 }
1009 ASSERT(zap == zn->zn_zap);
1010 zap_name_free(zn);
1011 if (zap != NULL) /* may be NULL if fzap_add() failed */
1012 zap_unlockdir(zap);
1013 return (err);
1014 }
1015
1016 int
1017 zap_add_uint64(objset_t *os, uint64_t zapobj, const uint64_t *key,
1018 int key_numints, int integer_size, uint64_t num_integers,
1019 const void *val, dmu_tx_t *tx)
1020 {
1021 zap_t *zap;
1022 int err;
1023 zap_name_t *zn;
1024
1025 err = zap_lockdir(os, zapobj, tx, RW_WRITER, TRUE, TRUE, &zap);
1026 if (err)
1027 return (err);
1028 zn = zap_name_alloc_uint64(zap, key, key_numints);
1029 if (zn == NULL) {
1030 zap_unlockdir(zap);
1031 return (ENOTSUP);
1032 }
1033 err = fzap_add(zn, integer_size, num_integers, val, tx);
1034 zap = zn->zn_zap; /* fzap_add() may change zap */
1035 zap_name_free(zn);
1036 if (zap != NULL) /* may be NULL if fzap_add() failed */
1037 zap_unlockdir(zap);
1038 return (err);
1039 }
1040
1041 int
1042 zap_update(objset_t *os, uint64_t zapobj, const char *name,
1043 int integer_size, uint64_t num_integers, const void *val, dmu_tx_t *tx)
1044 {
1045 zap_t *zap;
1046 mzap_ent_t *mze;
1047 uint64_t oldval;
1048 const uint64_t *intval = val;
1049 zap_name_t *zn;
1050 int err;
1051
1052 #ifdef ZFS_DEBUG
1053 /*
1054 * If there is an old value, it shouldn't change across the
1055 * lockdir (eg, due to bprewrite's xlation).
1056 */
1057 if (integer_size == 8 && num_integers == 1)
1058 (void) zap_lookup(os, zapobj, name, 8, 1, &oldval);
1059 #endif
1060
1061 err = zap_lockdir(os, zapobj, tx, RW_WRITER, TRUE, TRUE, &zap);
1062 if (err)
1063 return (err);
1064 zn = zap_name_alloc(zap, name, MT_EXACT);
1065 if (zn == NULL) {
1066 zap_unlockdir(zap);
1067 return (ENOTSUP);
1068 }
1069 if (!zap->zap_ismicro) {
1070 err = fzap_update(zn, integer_size, num_integers, val, tx);
1071 zap = zn->zn_zap; /* fzap_update() may change zap */
1072 } else if (integer_size != 8 || num_integers != 1 ||
1073 strlen(name) >= MZAP_NAME_LEN) {
1074 dprintf("upgrading obj %llu: intsz=%u numint=%llu name=%s\n",
1075 zapobj, integer_size, num_integers, name);
1076 err = mzap_upgrade(&zn->zn_zap, tx, 0);
1077 if (err == 0)
1078 err = fzap_update(zn, integer_size, num_integers,
1079 val, tx);
1080 zap = zn->zn_zap; /* fzap_update() may change zap */
1081 } else {
1082 mze = mze_find(zn);
1083 if (mze != NULL) {
1084 ASSERT3U(MZE_PHYS(zap, mze)->mze_value, ==, oldval);
1085 MZE_PHYS(zap, mze)->mze_value = *intval;
1086 } else {
1087 mzap_addent(zn, *intval);
1088 }
1089 }
1090 ASSERT(zap == zn->zn_zap);
1091 zap_name_free(zn);
1092 if (zap != NULL) /* may be NULL if fzap_upgrade() failed */
1093 zap_unlockdir(zap);
1094 return (err);
1095 }
1096
1097 int
1098 zap_update_uint64(objset_t *os, uint64_t zapobj, const uint64_t *key,
1099 int key_numints,
1100 int integer_size, uint64_t num_integers, const void *val, dmu_tx_t *tx)
1101 {
1102 zap_t *zap;
1103 zap_name_t *zn;
1104 int err;
1105
1106 err = zap_lockdir(os, zapobj, tx, RW_WRITER, TRUE, TRUE, &zap);
1107 if (err)
1108 return (err);
1109 zn = zap_name_alloc_uint64(zap, key, key_numints);
1110 if (zn == NULL) {
1111 zap_unlockdir(zap);
1112 return (ENOTSUP);
1113 }
1114 err = fzap_update(zn, integer_size, num_integers, val, tx);
1115 zap = zn->zn_zap; /* fzap_update() may change zap */
1116 zap_name_free(zn);
1117 if (zap != NULL) /* may be NULL if fzap_upgrade() failed */
1118 zap_unlockdir(zap);
1119 return (err);
1120 }
1121
1122 int
1123 zap_remove(objset_t *os, uint64_t zapobj, const char *name, dmu_tx_t *tx)
1124 {
1125 return (zap_remove_norm(os, zapobj, name, MT_EXACT, tx));
1126 }
1127
1128 int
1129 zap_remove_norm(objset_t *os, uint64_t zapobj, const char *name,
1130 matchtype_t mt, dmu_tx_t *tx)
1131 {
1132 zap_t *zap;
1133 int err;
1134 mzap_ent_t *mze;
1135 zap_name_t *zn;
1136
1137 err = zap_lockdir(os, zapobj, tx, RW_WRITER, TRUE, FALSE, &zap);
1138 if (err)
1139 return (err);
1140 zn = zap_name_alloc(zap, name, mt);
1141 if (zn == NULL) {
1142 zap_unlockdir(zap);
1143 return (ENOTSUP);
1144 }
1145 if (!zap->zap_ismicro) {
1146 err = fzap_remove(zn, tx);
1147 } else {
1148 mze = mze_find(zn);
1149 if (mze == NULL) {
1150 err = ENOENT;
1151 } else {
1152 zap->zap_m.zap_num_entries--;
1153 bzero(&zap->zap_m.zap_phys->mz_chunk[mze->mze_chunkid],
1154 sizeof (mzap_ent_phys_t));
1155 mze_remove(zap, mze);
1156 }
1157 }
1158 zap_name_free(zn);
1159 zap_unlockdir(zap);
1160 return (err);
1161 }
1162
1163 int
1164 zap_remove_uint64(objset_t *os, uint64_t zapobj, const uint64_t *key,
1165 int key_numints, dmu_tx_t *tx)
1166 {
1167 zap_t *zap;
1168 int err;
1169 zap_name_t *zn;
1170
1171 err = zap_lockdir(os, zapobj, tx, RW_WRITER, TRUE, FALSE, &zap);
1172 if (err)
1173 return (err);
1174 zn = zap_name_alloc_uint64(zap, key, key_numints);
1175 if (zn == NULL) {
1176 zap_unlockdir(zap);
1177 return (ENOTSUP);
1178 }
1179 err = fzap_remove(zn, tx);
1180 zap_name_free(zn);
1181 zap_unlockdir(zap);
1182 return (err);
1183 }
1184
1185 /*
1186 * Routines for iterating over the attributes.
1187 */
1188
1189 void
1190 zap_cursor_init_serialized(zap_cursor_t *zc, objset_t *os, uint64_t zapobj,
1191 uint64_t serialized)
1192 {
1193 zc->zc_objset = os;
1194 zc->zc_zap = NULL;
1195 zc->zc_leaf = NULL;
1196 zc->zc_zapobj = zapobj;
1197 zc->zc_serialized = serialized;
1198 zc->zc_hash = 0;
1199 zc->zc_cd = 0;
1200 }
1201
1202 void
1203 zap_cursor_init(zap_cursor_t *zc, objset_t *os, uint64_t zapobj)
1204 {
1205 zap_cursor_init_serialized(zc, os, zapobj, 0);
1206 }
1207
1208 void
1209 zap_cursor_fini(zap_cursor_t *zc)
1210 {
1211 if (zc->zc_zap) {
1212 rw_enter(&zc->zc_zap->zap_rwlock, RW_READER);
1213 zap_unlockdir(zc->zc_zap);
1214 zc->zc_zap = NULL;
1215 }
1216 if (zc->zc_leaf) {
1217 rw_enter(&zc->zc_leaf->l_rwlock, RW_READER);
1218 zap_put_leaf(zc->zc_leaf);
1219 zc->zc_leaf = NULL;
1220 }
1221 zc->zc_objset = NULL;
1222 }
1223
1224 uint64_t
1225 zap_cursor_serialize(zap_cursor_t *zc)
1226 {
1227 if (zc->zc_hash == -1ULL)
1228 return (-1ULL);
1229 if (zc->zc_zap == NULL)
1230 return (zc->zc_serialized);
1231 ASSERT((zc->zc_hash & zap_maxcd(zc->zc_zap)) == 0);
1232 ASSERT(zc->zc_cd < zap_maxcd(zc->zc_zap));
1233
1234 /*
1235 * We want to keep the high 32 bits of the cursor zero if we can, so
1236 * that 32-bit programs can access this. So usually use a small
1237 * (28-bit) hash value so we can fit 4 bits of cd into the low 32-bits
1238 * of the cursor.
1239 *
1240 * [ collision differentiator | zap_hashbits()-bit hash value ]
1241 */
1242 return ((zc->zc_hash >> (64 - zap_hashbits(zc->zc_zap))) |
1243 ((uint64_t)zc->zc_cd << zap_hashbits(zc->zc_zap)));
1244 }
1245
1246 int
1247 zap_cursor_retrieve(zap_cursor_t *zc, zap_attribute_t *za)
1248 {
1249 int err;
1250 avl_index_t idx;
1251 mzap_ent_t mze_tofind;
1252 mzap_ent_t *mze;
1253
1254 if (zc->zc_hash == -1ULL)
1255 return (ENOENT);
1256
1257 if (zc->zc_zap == NULL) {
1258 int hb;
1259 err = zap_lockdir(zc->zc_objset, zc->zc_zapobj, NULL,
1260 RW_READER, TRUE, FALSE, &zc->zc_zap);
1261 if (err)
1262 return (err);
1263
1264 /*
1265 * To support zap_cursor_init_serialized, advance, retrieve,
1266 * we must add to the existing zc_cd, which may already
1267 * be 1 due to the zap_cursor_advance.
1268 */
1269 ASSERT(zc->zc_hash == 0);
1270 hb = zap_hashbits(zc->zc_zap);
1271 zc->zc_hash = zc->zc_serialized << (64 - hb);
1272 zc->zc_cd += zc->zc_serialized >> hb;
1273 if (zc->zc_cd >= zap_maxcd(zc->zc_zap)) /* corrupt serialized */
1274 zc->zc_cd = 0;
1275 } else {
1276 rw_enter(&zc->zc_zap->zap_rwlock, RW_READER);
1277 }
1278 if (!zc->zc_zap->zap_ismicro) {
1279 err = fzap_cursor_retrieve(zc->zc_zap, zc, za);
1280 } else {
1281 err = ENOENT;
1282
1283 mze_tofind.mze_hash = zc->zc_hash;
1284 mze_tofind.mze_cd = zc->zc_cd;
1285
1286 mze = avl_find(&zc->zc_zap->zap_m.zap_avl, &mze_tofind, &idx);
1287 if (mze == NULL) {
1288 mze = avl_nearest(&zc->zc_zap->zap_m.zap_avl,
1289 idx, AVL_AFTER);
1290 }
1291 if (mze) {
1292 mzap_ent_phys_t *mzep = MZE_PHYS(zc->zc_zap, mze);
1293 ASSERT3U(mze->mze_cd, ==, mzep->mze_cd);
1294 za->za_normalization_conflict =
1295 mzap_normalization_conflict(zc->zc_zap, NULL, mze);
1296 za->za_integer_length = 8;
1297 za->za_num_integers = 1;
1298 za->za_first_integer = mzep->mze_value;
1299 (void) strcpy(za->za_name, mzep->mze_name);
1300 zc->zc_hash = mze->mze_hash;
1301 zc->zc_cd = mze->mze_cd;
1302 err = 0;
1303 } else {
1304 zc->zc_hash = -1ULL;
1305 }
1306 }
1307 rw_exit(&zc->zc_zap->zap_rwlock);
1308 return (err);
1309 }
1310
1311 void
1312 zap_cursor_advance(zap_cursor_t *zc)
1313 {
1314 if (zc->zc_hash == -1ULL)
1315 return;
1316 zc->zc_cd++;
1317 }
1318
1319 int
1320 zap_cursor_move_to_key(zap_cursor_t *zc, const char *name, matchtype_t mt)
1321 {
1322 int err = 0;
1323 mzap_ent_t *mze;
1324 zap_name_t *zn;
1325
1326 if (zc->zc_zap == NULL) {
1327 err = zap_lockdir(zc->zc_objset, zc->zc_zapobj, NULL,
1328 RW_READER, TRUE, FALSE, &zc->zc_zap);
1329 if (err)
1330 return (err);
1331 } else {
1332 rw_enter(&zc->zc_zap->zap_rwlock, RW_READER);
1333 }
1334
1335 zn = zap_name_alloc(zc->zc_zap, name, mt);
1336 if (zn == NULL) {
1337 rw_exit(&zc->zc_zap->zap_rwlock);
1338 return (ENOTSUP);
1339 }
1340
1341 if (!zc->zc_zap->zap_ismicro) {
1342 err = fzap_cursor_move_to_key(zc, zn);
1343 } else {
1344 mze = mze_find(zn);
1345 if (mze == NULL) {
1346 err = ENOENT;
1347 goto out;
1348 }
1349 zc->zc_hash = mze->mze_hash;
1350 zc->zc_cd = mze->mze_cd;
1351 }
1352
1353 out:
1354 zap_name_free(zn);
1355 rw_exit(&zc->zc_zap->zap_rwlock);
1356 return (err);
1357 }
1358
1359 int
1360 zap_get_stats(objset_t *os, uint64_t zapobj, zap_stats_t *zs)
1361 {
1362 int err;
1363 zap_t *zap;
1364
1365 err = zap_lockdir(os, zapobj, NULL, RW_READER, TRUE, FALSE, &zap);
1366 if (err)
1367 return (err);
1368
1369 bzero(zs, sizeof (zap_stats_t));
1370
1371 if (zap->zap_ismicro) {
1372 zs->zs_blocksize = zap->zap_dbuf->db_size;
1373 zs->zs_num_entries = zap->zap_m.zap_num_entries;
1374 zs->zs_num_blocks = 1;
1375 } else {
1376 fzap_get_stats(zap, zs);
1377 }
1378 zap_unlockdir(zap);
1379 return (0);
1380 }
1381
1382 int
1383 zap_count_write(objset_t *os, uint64_t zapobj, const char *name, int add,
1384 uint64_t *towrite, uint64_t *tooverwrite)
1385 {
1386 zap_t *zap;
1387 int err = 0;
1388
1389
1390 /*
1391 * Since, we don't have a name, we cannot figure out which blocks will
1392 * be affected in this operation. So, account for the worst case :
1393 * - 3 blocks overwritten: target leaf, ptrtbl block, header block
1394 * - 4 new blocks written if adding:
1395 * - 2 blocks for possibly split leaves,
1396 * - 2 grown ptrtbl blocks
1397 *
1398 * This also accomodates the case where an add operation to a fairly
1399 * large microzap results in a promotion to fatzap.
1400 */
1401 if (name == NULL) {
1402 *towrite += (3 + (add ? 4 : 0)) * SPA_MAXBLOCKSIZE;
1403 return (err);
1404 }
1405
1406 /*
1407 * We lock the zap with adding == FALSE. Because, if we pass
1408 * the actual value of add, it could trigger a mzap_upgrade().
1409 * At present we are just evaluating the possibility of this operation
1410 * and hence we donot want to trigger an upgrade.
1411 */
1412 err = zap_lockdir(os, zapobj, NULL, RW_READER, TRUE, FALSE, &zap);
1413 if (err)
1414 return (err);
1415
1416 if (!zap->zap_ismicro) {
1417 zap_name_t *zn = zap_name_alloc(zap, name, MT_EXACT);
1418 if (zn) {
1419 err = fzap_count_write(zn, add, towrite,
1420 tooverwrite);
1421 zap_name_free(zn);
1422 } else {
1423 /*
1424 * We treat this case as similar to (name == NULL)
1425 */
1426 *towrite += (3 + (add ? 4 : 0)) * SPA_MAXBLOCKSIZE;
1427 }
1428 } else {
1429 /*
1430 * We are here if (name != NULL) and this is a micro-zap.
1431 * We account for the header block depending on whether it
1432 * is freeable.
1433 *
1434 * Incase of an add-operation it is hard to find out
1435 * if this add will promote this microzap to fatzap.
1436 * Hence, we consider the worst case and account for the
1437 * blocks assuming this microzap would be promoted to a
1438 * fatzap.
1439 *
1440 * 1 block overwritten : header block
1441 * 4 new blocks written : 2 new split leaf, 2 grown
1442 * ptrtbl blocks
1443 */
1444 if (dmu_buf_freeable(zap->zap_dbuf))
1445 *tooverwrite += SPA_MAXBLOCKSIZE;
1446 else
1447 *towrite += SPA_MAXBLOCKSIZE;
1448
1449 if (add) {
1450 *towrite += 4 * SPA_MAXBLOCKSIZE;
1451 }
1452 }
1453
1454 zap_unlockdir(zap);
1455 return (err);
1456 }