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5056 ZFS deadlock on db_mtx and dn_holds
[illumos-gate.git] / usr / src / uts / common / fs / zfs / zap_micro.c
blob3742471f78e6485885e523af80fc847690e9e591
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) 2011, 2014 by Delphix. All rights reserved.
24 * Copyright (c) 2014 Spectra Logic Corporation, All rights reserved.
25 */
26
27 #include <sys/zio.h>
28 #include <sys/spa.h>
29 #include <sys/dmu.h>
30 #include <sys/zfs_context.h>
31 #include <sys/zap.h>
32 #include <sys/refcount.h>
33 #include <sys/zap_impl.h>
34 #include <sys/zap_leaf.h>
35 #include <sys/avl.h>
36 #include <sys/arc.h>
37 #include <sys/dmu_objset.h>
38
39 #ifdef _KERNEL
40 #include <sys/sunddi.h>
41 #endif
42
43 extern inline mzap_phys_t *zap_m_phys(zap_t *zap);
44
45 static int mzap_upgrade(zap_t **zapp, dmu_tx_t *tx, zap_flags_t flags);
46
47 uint64_t
48 zap_getflags(zap_t *zap)
49 {
50 if (zap->zap_ismicro)
51 return (0);
52 return (zap_f_phys(zap)->zap_flags);
53 }
54
55 int
56 zap_hashbits(zap_t *zap)
57 {
58 if (zap_getflags(zap) & ZAP_FLAG_HASH64)
59 return (48);
60 else
61 return (28);
62 }
63
64 uint32_t
65 zap_maxcd(zap_t *zap)
66 {
67 if (zap_getflags(zap) & ZAP_FLAG_HASH64)
68 return ((1<<16)-1);
69 else
70 return (-1U);
71 }
72
73 static uint64_t
74 zap_hash(zap_name_t *zn)
75 {
76 zap_t *zap = zn->zn_zap;
77 uint64_t h = 0;
78
79 if (zap_getflags(zap) & ZAP_FLAG_PRE_HASHED_KEY) {
80 ASSERT(zap_getflags(zap) & ZAP_FLAG_UINT64_KEY);
81 h = *(uint64_t *)zn->zn_key_orig;
82 } else {
83 h = zap->zap_salt;
84 ASSERT(h != 0);
85 ASSERT(zfs_crc64_table[128] == ZFS_CRC64_POLY);
86
87 if (zap_getflags(zap) & ZAP_FLAG_UINT64_KEY) {
88 int i;
89 const uint64_t *wp = zn->zn_key_norm;
90
91 ASSERT(zn->zn_key_intlen == 8);
92 for (i = 0; i < zn->zn_key_norm_numints; wp++, i++) {
93 int j;
94 uint64_t word = *wp;
95
96 for (j = 0; j < zn->zn_key_intlen; j++) {
97 h = (h >> 8) ^
98 zfs_crc64_table[(h ^ word) & 0xFF];
99 word >>= NBBY;
100 }
101 }
102 } else {
103 int i, len;
104 const uint8_t *cp = zn->zn_key_norm;
105
106 /*
107 * We previously stored the terminating null on
108 * disk, but didn't hash it, so we need to
109 * continue to not hash it. (The
110 * zn_key_*_numints includes the terminating
111 * null for non-binary keys.)
112 */
113 len = zn->zn_key_norm_numints - 1;
114
115 ASSERT(zn->zn_key_intlen == 1);
116 for (i = 0; i < len; cp++, i++) {
117 h = (h >> 8) ^
118 zfs_crc64_table[(h ^ *cp) & 0xFF];
119 }
120 }
121 }
122 /*
123 * Don't use all 64 bits, since we need some in the cookie for
124 * the collision differentiator. We MUST use the high bits,
125 * since those are the ones that we first pay attention to when
126 * chosing the bucket.
127 */
128 h &= ~((1ULL << (64 - zap_hashbits(zap))) - 1);
129
130 return (h);
131 }
132
133 static int
134 zap_normalize(zap_t *zap, const char *name, char *namenorm)
135 {
136 size_t inlen, outlen;
137 int err;
138
139 ASSERT(!(zap_getflags(zap) & ZAP_FLAG_UINT64_KEY));
140
141 inlen = strlen(name) + 1;
142 outlen = ZAP_MAXNAMELEN;
143
144 err = 0;
145 (void) u8_textprep_str((char *)name, &inlen, namenorm, &outlen,
146 zap->zap_normflags | U8_TEXTPREP_IGNORE_NULL |
147 U8_TEXTPREP_IGNORE_INVALID, U8_UNICODE_LATEST, &err);
148
149 return (err);
150 }
151
152 boolean_t
153 zap_match(zap_name_t *zn, const char *matchname)
154 {
155 ASSERT(!(zap_getflags(zn->zn_zap) & ZAP_FLAG_UINT64_KEY));
156
157 if (zn->zn_matchtype == MT_FIRST) {
158 char norm[ZAP_MAXNAMELEN];
159
160 if (zap_normalize(zn->zn_zap, matchname, norm) != 0)
161 return (B_FALSE);
162
163 return (strcmp(zn->zn_key_norm, norm) == 0);
164 } else {
165 /* MT_BEST or MT_EXACT */
166 return (strcmp(zn->zn_key_orig, matchname) == 0);
167 }
168 }
169
170 void
171 zap_name_free(zap_name_t *zn)
172 {
173 kmem_free(zn, sizeof (zap_name_t));
174 }
175
176 zap_name_t *
177 zap_name_alloc(zap_t *zap, const char *key, matchtype_t mt)
178 {
179 zap_name_t *zn = kmem_alloc(sizeof (zap_name_t), KM_SLEEP);
180
181 zn->zn_zap = zap;
182 zn->zn_key_intlen = sizeof (*key);
183 zn->zn_key_orig = key;
184 zn->zn_key_orig_numints = strlen(zn->zn_key_orig) + 1;
185 zn->zn_matchtype = mt;
186 if (zap->zap_normflags) {
187 if (zap_normalize(zap, key, zn->zn_normbuf) != 0) {
188 zap_name_free(zn);
189 return (NULL);
190 }
191 zn->zn_key_norm = zn->zn_normbuf;
192 zn->zn_key_norm_numints = strlen(zn->zn_key_norm) + 1;
193 } else {
194 if (mt != MT_EXACT) {
195 zap_name_free(zn);
196 return (NULL);
197 }
198 zn->zn_key_norm = zn->zn_key_orig;
199 zn->zn_key_norm_numints = zn->zn_key_orig_numints;
200 }
201
202 zn->zn_hash = zap_hash(zn);
203 return (zn);
204 }
205
206 zap_name_t *
207 zap_name_alloc_uint64(zap_t *zap, const uint64_t *key, int numints)
208 {
209 zap_name_t *zn = kmem_alloc(sizeof (zap_name_t), KM_SLEEP);
210
211 ASSERT(zap->zap_normflags == 0);
212 zn->zn_zap = zap;
213 zn->zn_key_intlen = sizeof (*key);
214 zn->zn_key_orig = zn->zn_key_norm = key;
215 zn->zn_key_orig_numints = zn->zn_key_norm_numints = numints;
216 zn->zn_matchtype = MT_EXACT;
217
218 zn->zn_hash = zap_hash(zn);
219 return (zn);
220 }
221
222 static void
223 mzap_byteswap(mzap_phys_t *buf, size_t size)
224 {
225 int i, max;
226 buf->mz_block_type = BSWAP_64(buf->mz_block_type);
227 buf->mz_salt = BSWAP_64(buf->mz_salt);
228 buf->mz_normflags = BSWAP_64(buf->mz_normflags);
229 max = (size / MZAP_ENT_LEN) - 1;
230 for (i = 0; i < max; i++) {
231 buf->mz_chunk[i].mze_value =
232 BSWAP_64(buf->mz_chunk[i].mze_value);
233 buf->mz_chunk[i].mze_cd =
234 BSWAP_32(buf->mz_chunk[i].mze_cd);
235 }
236 }
237
238 void
239 zap_byteswap(void *buf, size_t size)
240 {
241 uint64_t block_type;
242
243 block_type = *(uint64_t *)buf;
244
245 if (block_type == ZBT_MICRO || block_type == BSWAP_64(ZBT_MICRO)) {
246 /* ASSERT(magic == ZAP_LEAF_MAGIC); */
247 mzap_byteswap(buf, size);
248 } else {
249 fzap_byteswap(buf, size);
250 }
251 }
252
253 static int
254 mze_compare(const void *arg1, const void *arg2)
255 {
256 const mzap_ent_t *mze1 = arg1;
257 const mzap_ent_t *mze2 = arg2;
258
259 if (mze1->mze_hash > mze2->mze_hash)
260 return (+1);
261 if (mze1->mze_hash < mze2->mze_hash)
262 return (-1);
263 if (mze1->mze_cd > mze2->mze_cd)
264 return (+1);
265 if (mze1->mze_cd < mze2->mze_cd)
266 return (-1);
267 return (0);
268 }
269
270 static void
271 mze_insert(zap_t *zap, int chunkid, uint64_t hash)
272 {
273 mzap_ent_t *mze;
274
275 ASSERT(zap->zap_ismicro);
276 ASSERT(RW_WRITE_HELD(&zap->zap_rwlock));
277
278 mze = kmem_alloc(sizeof (mzap_ent_t), KM_SLEEP);
279 mze->mze_chunkid = chunkid;
280 mze->mze_hash = hash;
281 mze->mze_cd = MZE_PHYS(zap, mze)->mze_cd;
282 ASSERT(MZE_PHYS(zap, mze)->mze_name[0] != 0);
283 avl_add(&zap->zap_m.zap_avl, mze);
284 }
285
286 static mzap_ent_t *
287 mze_find(zap_name_t *zn)
288 {
289 mzap_ent_t mze_tofind;
290 mzap_ent_t *mze;
291 avl_index_t idx;
292 avl_tree_t *avl = &zn->zn_zap->zap_m.zap_avl;
293
294 ASSERT(zn->zn_zap->zap_ismicro);
295 ASSERT(RW_LOCK_HELD(&zn->zn_zap->zap_rwlock));
296
297 mze_tofind.mze_hash = zn->zn_hash;
298 mze_tofind.mze_cd = 0;
299
300 again:
301 mze = avl_find(avl, &mze_tofind, &idx);
302 if (mze == NULL)
303 mze = avl_nearest(avl, idx, AVL_AFTER);
304 for (; mze && mze->mze_hash == zn->zn_hash; mze = AVL_NEXT(avl, mze)) {
305 ASSERT3U(mze->mze_cd, ==, MZE_PHYS(zn->zn_zap, mze)->mze_cd);
306 if (zap_match(zn, MZE_PHYS(zn->zn_zap, mze)->mze_name))
307 return (mze);
308 }
309 if (zn->zn_matchtype == MT_BEST) {
310 zn->zn_matchtype = MT_FIRST;
311 goto again;
312 }
313 return (NULL);
314 }
315
316 static uint32_t
317 mze_find_unused_cd(zap_t *zap, uint64_t hash)
318 {
319 mzap_ent_t mze_tofind;
320 mzap_ent_t *mze;
321 avl_index_t idx;
322 avl_tree_t *avl = &zap->zap_m.zap_avl;
323 uint32_t cd;
324
325 ASSERT(zap->zap_ismicro);
326 ASSERT(RW_LOCK_HELD(&zap->zap_rwlock));
327
328 mze_tofind.mze_hash = hash;
329 mze_tofind.mze_cd = 0;
330
331 cd = 0;
332 for (mze = avl_find(avl, &mze_tofind, &idx);
333 mze && mze->mze_hash == hash; mze = AVL_NEXT(avl, mze)) {
334 if (mze->mze_cd != cd)
335 break;
336 cd++;
337 }
338
339 return (cd);
340 }
341
342 static void
343 mze_remove(zap_t *zap, mzap_ent_t *mze)
344 {
345 ASSERT(zap->zap_ismicro);
346 ASSERT(RW_WRITE_HELD(&zap->zap_rwlock));
347
348 avl_remove(&zap->zap_m.zap_avl, mze);
349 kmem_free(mze, sizeof (mzap_ent_t));
350 }
351
352 static void
353 mze_destroy(zap_t *zap)
354 {
355 mzap_ent_t *mze;
356 void *avlcookie = NULL;
357
358 while (mze = avl_destroy_nodes(&zap->zap_m.zap_avl, &avlcookie))
359 kmem_free(mze, sizeof (mzap_ent_t));
360 avl_destroy(&zap->zap_m.zap_avl);
361 }
362
363 static zap_t *
364 mzap_open(objset_t *os, uint64_t obj, dmu_buf_t *db)
365 {
366 zap_t *winner;
367 zap_t *zap;
368 int i;
369
370 ASSERT3U(MZAP_ENT_LEN, ==, sizeof (mzap_ent_phys_t));
371
372 zap = kmem_zalloc(sizeof (zap_t), KM_SLEEP);
373 rw_init(&zap->zap_rwlock, 0, 0, 0);
374 rw_enter(&zap->zap_rwlock, RW_WRITER);
375 zap->zap_objset = os;
376 zap->zap_object = obj;
377 zap->zap_dbuf = db;
378
379 if (*(uint64_t *)db->db_data != ZBT_MICRO) {
380 mutex_init(&zap->zap_f.zap_num_entries_mtx, 0, 0, 0);
381 zap->zap_f.zap_block_shift = highbit64(db->db_size) - 1;
382 } else {
383 zap->zap_ismicro = TRUE;
384 }
385
386 /*
387 * Make sure that zap_ismicro is set before we let others see
388 * it, because zap_lockdir() checks zap_ismicro without the lock
389 * held.
390 */
391 dmu_buf_init_user(&zap->zap_dbu, zap_evict, &zap->zap_dbuf);
392 winner = dmu_buf_set_user(db, &zap->zap_dbu);
393
394 if (winner != NULL) {
395 rw_exit(&zap->zap_rwlock);
396 rw_destroy(&zap->zap_rwlock);
397 if (!zap->zap_ismicro)
398 mutex_destroy(&zap->zap_f.zap_num_entries_mtx);
399 kmem_free(zap, sizeof (zap_t));
400 return (winner);
401 }
402
403 if (zap->zap_ismicro) {
404 zap->zap_salt = zap_m_phys(zap)->mz_salt;
405 zap->zap_normflags = zap_m_phys(zap)->mz_normflags;
406 zap->zap_m.zap_num_chunks = db->db_size / MZAP_ENT_LEN - 1;
407 avl_create(&zap->zap_m.zap_avl, mze_compare,
408 sizeof (mzap_ent_t), offsetof(mzap_ent_t, mze_node));
409
410 for (i = 0; i < zap->zap_m.zap_num_chunks; i++) {
411 mzap_ent_phys_t *mze =
412 &zap_m_phys(zap)->mz_chunk[i];
413 if (mze->mze_name[0]) {
414 zap_name_t *zn;
415
416 zap->zap_m.zap_num_entries++;
417 zn = zap_name_alloc(zap, mze->mze_name,
418 MT_EXACT);
419 mze_insert(zap, i, zn->zn_hash);
420 zap_name_free(zn);
421 }
422 }
423 } else {
424 zap->zap_salt = zap_f_phys(zap)->zap_salt;
425 zap->zap_normflags = zap_f_phys(zap)->zap_normflags;
426
427 ASSERT3U(sizeof (struct zap_leaf_header), ==,
428 2*ZAP_LEAF_CHUNKSIZE);
429
430 /*
431 * The embedded pointer table should not overlap the
432 * other members.
433 */
434 ASSERT3P(&ZAP_EMBEDDED_PTRTBL_ENT(zap, 0), >,
435 &zap_f_phys(zap)->zap_salt);
436
437 /*
438 * The embedded pointer table should end at the end of
439 * the block
440 */
441 ASSERT3U((uintptr_t)&ZAP_EMBEDDED_PTRTBL_ENT(zap,
442 1<<ZAP_EMBEDDED_PTRTBL_SHIFT(zap)) -
443 (uintptr_t)zap_f_phys(zap), ==,
444 zap->zap_dbuf->db_size);
445 }
446 rw_exit(&zap->zap_rwlock);
447 return (zap);
448 }
449
450 int
451 zap_lockdir(objset_t *os, uint64_t obj, dmu_tx_t *tx,
452 krw_t lti, boolean_t fatreader, boolean_t adding, zap_t **zapp)
453 {
454 zap_t *zap;
455 dmu_buf_t *db;
456 krw_t lt;
457 int err;
458
459 *zapp = NULL;
460
461 err = dmu_buf_hold(os, obj, 0, NULL, &db, DMU_READ_NO_PREFETCH);
462 if (err)
463 return (err);
464
465 #ifdef ZFS_DEBUG
466 {
467 dmu_object_info_t doi;
468 dmu_object_info_from_db(db, &doi);
469 ASSERT3U(DMU_OT_BYTESWAP(doi.doi_type), ==, DMU_BSWAP_ZAP);
470 }
471 #endif
472
473 zap = dmu_buf_get_user(db);
474 if (zap == NULL)
475 zap = mzap_open(os, obj, db);
476
477 /*
478 * We're checking zap_ismicro without the lock held, in order to
479 * tell what type of lock we want. Once we have some sort of
480 * lock, see if it really is the right type. In practice this
481 * can only be different if it was upgraded from micro to fat,
482 * and micro wanted WRITER but fat only needs READER.
483 */
484 lt = (!zap->zap_ismicro && fatreader) ? RW_READER : lti;
485 rw_enter(&zap->zap_rwlock, lt);
486 if (lt != ((!zap->zap_ismicro && fatreader) ? RW_READER : lti)) {
487 /* it was upgraded, now we only need reader */
488 ASSERT(lt == RW_WRITER);
489 ASSERT(RW_READER ==
490 (!zap->zap_ismicro && fatreader) ? RW_READER : lti);
491 rw_downgrade(&zap->zap_rwlock);
492 lt = RW_READER;
493 }
494
495 zap->zap_objset = os;
496
497 if (lt == RW_WRITER)
498 dmu_buf_will_dirty(db, tx);
499
500 ASSERT3P(zap->zap_dbuf, ==, db);
501
502 ASSERT(!zap->zap_ismicro ||
503 zap->zap_m.zap_num_entries <= zap->zap_m.zap_num_chunks);
504 if (zap->zap_ismicro && tx && adding &&
505 zap->zap_m.zap_num_entries == zap->zap_m.zap_num_chunks) {
506 uint64_t newsz = db->db_size + SPA_MINBLOCKSIZE;
507 if (newsz > MZAP_MAX_BLKSZ) {
508 dprintf("upgrading obj %llu: num_entries=%u\n",
509 obj, zap->zap_m.zap_num_entries);
510 *zapp = zap;
511 return (mzap_upgrade(zapp, tx, 0));
512 }
513 err = dmu_object_set_blocksize(os, obj, newsz, 0, tx);
514 ASSERT0(err);
515 zap->zap_m.zap_num_chunks =
516 db->db_size / MZAP_ENT_LEN - 1;
517 }
518
519 *zapp = zap;
520 return (0);
521 }
522
523 void
524 zap_unlockdir(zap_t *zap)
525 {
526 rw_exit(&zap->zap_rwlock);
527 dmu_buf_rele(zap->zap_dbuf, NULL);
528 }
529
530 static int
531 mzap_upgrade(zap_t **zapp, dmu_tx_t *tx, zap_flags_t flags)
532 {
533 mzap_phys_t *mzp;
534 int i, sz, nchunks;
535 int err = 0;
536 zap_t *zap = *zapp;
537
538 ASSERT(RW_WRITE_HELD(&zap->zap_rwlock));
539
540 sz = zap->zap_dbuf->db_size;
541 mzp = kmem_alloc(sz, KM_SLEEP);
542 bcopy(zap->zap_dbuf->db_data, mzp, sz);
543 nchunks = zap->zap_m.zap_num_chunks;
544
545 if (!flags) {
546 err = dmu_object_set_blocksize(zap->zap_objset, zap->zap_object,
547 1ULL << fzap_default_block_shift, 0, tx);
548 if (err) {
549 kmem_free(mzp, sz);
550 return (err);
551 }
552 }
553
554 dprintf("upgrading obj=%llu with %u chunks\n",
555 zap->zap_object, nchunks);
556 /* XXX destroy the avl later, so we can use the stored hash value */
557 mze_destroy(zap);
558
559 fzap_upgrade(zap, tx, flags);
560
561 for (i = 0; i < nchunks; i++) {
562 mzap_ent_phys_t *mze = &mzp->mz_chunk[i];
563 zap_name_t *zn;
564 if (mze->mze_name[0] == 0)
565 continue;
566 dprintf("adding %s=%llu\n",
567 mze->mze_name, mze->mze_value);
568 zn = zap_name_alloc(zap, mze->mze_name, MT_EXACT);
569 err = fzap_add_cd(zn, 8, 1, &mze->mze_value, mze->mze_cd, tx);
570 zap = zn->zn_zap; /* fzap_add_cd() may change zap */
571 zap_name_free(zn);
572 if (err)
573 break;
574 }
575 kmem_free(mzp, sz);
576 *zapp = zap;
577 return (err);
578 }
579
580 void
581 mzap_create_impl(objset_t *os, uint64_t obj, int normflags, zap_flags_t flags,
582 dmu_tx_t *tx)
583 {
584 dmu_buf_t *db;
585 mzap_phys_t *zp;
586
587 VERIFY(0 == dmu_buf_hold(os, obj, 0, FTAG, &db, DMU_READ_NO_PREFETCH));
588
589 #ifdef ZFS_DEBUG
590 {
591 dmu_object_info_t doi;
592 dmu_object_info_from_db(db, &doi);
593 ASSERT3U(DMU_OT_BYTESWAP(doi.doi_type), ==, DMU_BSWAP_ZAP);
594 }
595 #endif
596
597 dmu_buf_will_dirty(db, tx);
598 zp = db->db_data;
599 zp->mz_block_type = ZBT_MICRO;
600 zp->mz_salt = ((uintptr_t)db ^ (uintptr_t)tx ^ (obj << 1)) | 1ULL;
601 zp->mz_normflags = normflags;
602 dmu_buf_rele(db, FTAG);
603
604 if (flags != 0) {
605 zap_t *zap;
606 /* Only fat zap supports flags; upgrade immediately. */
607 VERIFY(0 == zap_lockdir(os, obj, tx, RW_WRITER,
608 B_FALSE, B_FALSE, &zap));
609 VERIFY3U(0, ==, mzap_upgrade(&zap, tx, flags));
610 zap_unlockdir(zap);
611 }
612 }
613
614 int
615 zap_create_claim(objset_t *os, uint64_t obj, dmu_object_type_t ot,
616 dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx)
617 {
618 return (zap_create_claim_norm(os, obj,
619 0, ot, bonustype, bonuslen, tx));
620 }
621
622 int
623 zap_create_claim_norm(objset_t *os, uint64_t obj, int normflags,
624 dmu_object_type_t ot,
625 dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx)
626 {
627 int err;
628
629 err = dmu_object_claim(os, obj, ot, 0, bonustype, bonuslen, tx);
630 if (err != 0)
631 return (err);
632 mzap_create_impl(os, obj, normflags, 0, tx);
633 return (0);
634 }
635
636 uint64_t
637 zap_create(objset_t *os, dmu_object_type_t ot,
638 dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx)
639 {
640 return (zap_create_norm(os, 0, ot, bonustype, bonuslen, tx));
641 }
642
643 uint64_t
644 zap_create_norm(objset_t *os, int normflags, dmu_object_type_t ot,
645 dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx)
646 {
647 uint64_t obj = dmu_object_alloc(os, ot, 0, bonustype, bonuslen, tx);
648
649 mzap_create_impl(os, obj, normflags, 0, tx);
650 return (obj);
651 }
652
653 uint64_t
654 zap_create_flags(objset_t *os, int normflags, zap_flags_t flags,
655 dmu_object_type_t ot, int leaf_blockshift, int indirect_blockshift,
656 dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx)
657 {
658 uint64_t obj = dmu_object_alloc(os, ot, 0, bonustype, bonuslen, tx);
659
660 ASSERT(leaf_blockshift >= SPA_MINBLOCKSHIFT &&
661 leaf_blockshift <= SPA_OLD_MAXBLOCKSHIFT &&
662 indirect_blockshift >= SPA_MINBLOCKSHIFT &&
663 indirect_blockshift <= SPA_OLD_MAXBLOCKSHIFT);
664
665 VERIFY(dmu_object_set_blocksize(os, obj,
666 1ULL << leaf_blockshift, indirect_blockshift, tx) == 0);
667
668 mzap_create_impl(os, obj, normflags, flags, tx);
669 return (obj);
670 }
671
672 int
673 zap_destroy(objset_t *os, uint64_t zapobj, dmu_tx_t *tx)
674 {
675 /*
676 * dmu_object_free will free the object number and free the
677 * data. Freeing the data will cause our pageout function to be
678 * called, which will destroy our data (zap_leaf_t's and zap_t).
679 */
680
681 return (dmu_object_free(os, zapobj, tx));
682 }
683
684 void
685 zap_evict(void *dbu)
686 {
687 zap_t *zap = dbu;
688
689 rw_destroy(&zap->zap_rwlock);
690
691 if (zap->zap_ismicro)
692 mze_destroy(zap);
693 else
694 mutex_destroy(&zap->zap_f.zap_num_entries_mtx);
695
696 kmem_free(zap, sizeof (zap_t));
697 }
698
699 int
700 zap_count(objset_t *os, uint64_t zapobj, uint64_t *count)
701 {
702 zap_t *zap;
703 int err;
704
705 err = zap_lockdir(os, zapobj, NULL, RW_READER, TRUE, FALSE, &zap);
706 if (err)
707 return (err);
708 if (!zap->zap_ismicro) {
709 err = fzap_count(zap, count);
710 } else {
711 *count = zap->zap_m.zap_num_entries;
712 }
713 zap_unlockdir(zap);
714 return (err);
715 }
716
717 /*
718 * zn may be NULL; if not specified, it will be computed if needed.
719 * See also the comment above zap_entry_normalization_conflict().
720 */
721 static boolean_t
722 mzap_normalization_conflict(zap_t *zap, zap_name_t *zn, mzap_ent_t *mze)
723 {
724 mzap_ent_t *other;
725 int direction = AVL_BEFORE;
726 boolean_t allocdzn = B_FALSE;
727
728 if (zap->zap_normflags == 0)
729 return (B_FALSE);
730
731 again:
732 for (other = avl_walk(&zap->zap_m.zap_avl, mze, direction);
733 other && other->mze_hash == mze->mze_hash;
734 other = avl_walk(&zap->zap_m.zap_avl, other, direction)) {
735
736 if (zn == NULL) {
737 zn = zap_name_alloc(zap, MZE_PHYS(zap, mze)->mze_name,
738 MT_FIRST);
739 allocdzn = B_TRUE;
740 }
741 if (zap_match(zn, MZE_PHYS(zap, other)->mze_name)) {
742 if (allocdzn)
743 zap_name_free(zn);
744 return (B_TRUE);
745 }
746 }
747
748 if (direction == AVL_BEFORE) {
749 direction = AVL_AFTER;
750 goto again;
751 }
752
753 if (allocdzn)
754 zap_name_free(zn);
755 return (B_FALSE);
756 }
757
758 /*
759 * Routines for manipulating attributes.
760 */
761
762 int
763 zap_lookup(objset_t *os, uint64_t zapobj, const char *name,
764 uint64_t integer_size, uint64_t num_integers, void *buf)
765 {
766 return (zap_lookup_norm(os, zapobj, name, integer_size,
767 num_integers, buf, MT_EXACT, NULL, 0, NULL));
768 }
769
770 int
771 zap_lookup_norm(objset_t *os, uint64_t zapobj, const char *name,
772 uint64_t integer_size, uint64_t num_integers, void *buf,
773 matchtype_t mt, char *realname, int rn_len,
774 boolean_t *ncp)
775 {
776 zap_t *zap;
777 int err;
778 mzap_ent_t *mze;
779 zap_name_t *zn;
780
781 err = zap_lockdir(os, zapobj, NULL, RW_READER, TRUE, FALSE, &zap);
782 if (err)
783 return (err);
784 zn = zap_name_alloc(zap, name, mt);
785 if (zn == NULL) {
786 zap_unlockdir(zap);
787 return (SET_ERROR(ENOTSUP));
788 }
789
790 if (!zap->zap_ismicro) {
791 err = fzap_lookup(zn, integer_size, num_integers, buf,
792 realname, rn_len, ncp);
793 } else {
794 mze = mze_find(zn);
795 if (mze == NULL) {
796 err = SET_ERROR(ENOENT);
797 } else {
798 if (num_integers < 1) {
799 err = SET_ERROR(EOVERFLOW);
800 } else if (integer_size != 8) {
801 err = SET_ERROR(EINVAL);
802 } else {
803 *(uint64_t *)buf =
804 MZE_PHYS(zap, mze)->mze_value;
805 (void) strlcpy(realname,
806 MZE_PHYS(zap, mze)->mze_name, rn_len);
807 if (ncp) {
808 *ncp = mzap_normalization_conflict(zap,
809 zn, mze);
810 }
811 }
812 }
813 }
814 zap_name_free(zn);
815 zap_unlockdir(zap);
816 return (err);
817 }
818
819 int
820 zap_prefetch_uint64(objset_t *os, uint64_t zapobj, const uint64_t *key,
821 int key_numints)
822 {
823 zap_t *zap;
824 int err;
825 zap_name_t *zn;
826
827 err = zap_lockdir(os, zapobj, NULL, RW_READER, TRUE, FALSE, &zap);
828 if (err)
829 return (err);
830 zn = zap_name_alloc_uint64(zap, key, key_numints);
831 if (zn == NULL) {
832 zap_unlockdir(zap);
833 return (SET_ERROR(ENOTSUP));
834 }
835
836 fzap_prefetch(zn);
837 zap_name_free(zn);
838 zap_unlockdir(zap);
839 return (err);
840 }
841
842 int
843 zap_lookup_uint64(objset_t *os, uint64_t zapobj, const uint64_t *key,
844 int key_numints, uint64_t integer_size, uint64_t num_integers, void *buf)
845 {
846 zap_t *zap;
847 int err;
848 zap_name_t *zn;
849
850 err = zap_lockdir(os, zapobj, NULL, RW_READER, TRUE, FALSE, &zap);
851 if (err)
852 return (err);
853 zn = zap_name_alloc_uint64(zap, key, key_numints);
854 if (zn == NULL) {
855 zap_unlockdir(zap);
856 return (SET_ERROR(ENOTSUP));
857 }
858
859 err = fzap_lookup(zn, integer_size, num_integers, buf,
860 NULL, 0, NULL);
861 zap_name_free(zn);
862 zap_unlockdir(zap);
863 return (err);
864 }
865
866 int
867 zap_contains(objset_t *os, uint64_t zapobj, const char *name)
868 {
869 int err = zap_lookup_norm(os, zapobj, name, 0,
870 0, NULL, MT_EXACT, NULL, 0, NULL);
871 if (err == EOVERFLOW || err == EINVAL)
872 err = 0; /* found, but skipped reading the value */
873 return (err);
874 }
875
876 int
877 zap_length(objset_t *os, uint64_t zapobj, const char *name,
878 uint64_t *integer_size, uint64_t *num_integers)
879 {
880 zap_t *zap;
881 int err;
882 mzap_ent_t *mze;
883 zap_name_t *zn;
884
885 err = zap_lockdir(os, zapobj, NULL, RW_READER, TRUE, FALSE, &zap);
886 if (err)
887 return (err);
888 zn = zap_name_alloc(zap, name, MT_EXACT);
889 if (zn == NULL) {
890 zap_unlockdir(zap);
891 return (SET_ERROR(ENOTSUP));
892 }
893 if (!zap->zap_ismicro) {
894 err = fzap_length(zn, integer_size, num_integers);
895 } else {
896 mze = mze_find(zn);
897 if (mze == NULL) {
898 err = SET_ERROR(ENOENT);
899 } else {
900 if (integer_size)
901 *integer_size = 8;
902 if (num_integers)
903 *num_integers = 1;
904 }
905 }
906 zap_name_free(zn);
907 zap_unlockdir(zap);
908 return (err);
909 }
910
911 int
912 zap_length_uint64(objset_t *os, uint64_t zapobj, const uint64_t *key,
913 int key_numints, uint64_t *integer_size, uint64_t *num_integers)
914 {
915 zap_t *zap;
916 int err;
917 zap_name_t *zn;
918
919 err = zap_lockdir(os, zapobj, NULL, RW_READER, TRUE, FALSE, &zap);
920 if (err)
921 return (err);
922 zn = zap_name_alloc_uint64(zap, key, key_numints);
923 if (zn == NULL) {
924 zap_unlockdir(zap);
925 return (SET_ERROR(ENOTSUP));
926 }
927 err = fzap_length(zn, integer_size, num_integers);
928 zap_name_free(zn);
929 zap_unlockdir(zap);
930 return (err);
931 }
932
933 static void
934 mzap_addent(zap_name_t *zn, uint64_t value)
935 {
936 int i;
937 zap_t *zap = zn->zn_zap;
938 int start = zap->zap_m.zap_alloc_next;
939 uint32_t cd;
940
941 ASSERT(RW_WRITE_HELD(&zap->zap_rwlock));
942
943 #ifdef ZFS_DEBUG
944 for (i = 0; i < zap->zap_m.zap_num_chunks; i++) {
945 mzap_ent_phys_t *mze = &zap_m_phys(zap)->mz_chunk[i];
946 ASSERT(strcmp(zn->zn_key_orig, mze->mze_name) != 0);
947 }
948 #endif
949
950 cd = mze_find_unused_cd(zap, zn->zn_hash);
951 /* given the limited size of the microzap, this can't happen */
952 ASSERT(cd < zap_maxcd(zap));
953
954 again:
955 for (i = start; i < zap->zap_m.zap_num_chunks; i++) {
956 mzap_ent_phys_t *mze = &zap_m_phys(zap)->mz_chunk[i];
957 if (mze->mze_name[0] == 0) {
958 mze->mze_value = value;
959 mze->mze_cd = cd;
960 (void) strcpy(mze->mze_name, zn->zn_key_orig);
961 zap->zap_m.zap_num_entries++;
962 zap->zap_m.zap_alloc_next = i+1;
963 if (zap->zap_m.zap_alloc_next ==
964 zap->zap_m.zap_num_chunks)
965 zap->zap_m.zap_alloc_next = 0;
966 mze_insert(zap, i, zn->zn_hash);
967 return;
968 }
969 }
970 if (start != 0) {
971 start = 0;
972 goto again;
973 }
974 ASSERT(!"out of entries!");
975 }
976
977 int
978 zap_add(objset_t *os, uint64_t zapobj, const char *key,
979 int integer_size, uint64_t num_integers,
980 const void *val, dmu_tx_t *tx)
981 {
982 zap_t *zap;
983 int err;
984 mzap_ent_t *mze;
985 const uint64_t *intval = val;
986 zap_name_t *zn;
987
988 err = zap_lockdir(os, zapobj, tx, RW_WRITER, TRUE, TRUE, &zap);
989 if (err)
990 return (err);
991 zn = zap_name_alloc(zap, key, MT_EXACT);
992 if (zn == NULL) {
993 zap_unlockdir(zap);
994 return (SET_ERROR(ENOTSUP));
995 }
996 if (!zap->zap_ismicro) {
997 err = fzap_add(zn, integer_size, num_integers, val, tx);
998 zap = zn->zn_zap; /* fzap_add() may change zap */
999 } else if (integer_size != 8 || num_integers != 1 ||
1000 strlen(key) >= MZAP_NAME_LEN) {
1001 err = mzap_upgrade(&zn->zn_zap, tx, 0);
1002 if (err == 0)
1003 err = fzap_add(zn, integer_size, num_integers, val, tx);
1004 zap = zn->zn_zap; /* fzap_add() may change zap */
1005 } else {
1006 mze = mze_find(zn);
1007 if (mze != NULL) {
1008 err = SET_ERROR(EEXIST);
1009 } else {
1010 mzap_addent(zn, *intval);
1011 }
1012 }
1013 ASSERT(zap == zn->zn_zap);
1014 zap_name_free(zn);
1015 if (zap != NULL) /* may be NULL if fzap_add() failed */
1016 zap_unlockdir(zap);
1017 return (err);
1018 }
1019
1020 int
1021 zap_add_uint64(objset_t *os, uint64_t zapobj, const uint64_t *key,
1022 int key_numints, int integer_size, uint64_t num_integers,
1023 const void *val, dmu_tx_t *tx)
1024 {
1025 zap_t *zap;
1026 int err;
1027 zap_name_t *zn;
1028
1029 err = zap_lockdir(os, zapobj, tx, RW_WRITER, TRUE, TRUE, &zap);
1030 if (err)
1031 return (err);
1032 zn = zap_name_alloc_uint64(zap, key, key_numints);
1033 if (zn == NULL) {
1034 zap_unlockdir(zap);
1035 return (SET_ERROR(ENOTSUP));
1036 }
1037 err = fzap_add(zn, integer_size, num_integers, val, tx);
1038 zap = zn->zn_zap; /* fzap_add() may change zap */
1039 zap_name_free(zn);
1040 if (zap != NULL) /* may be NULL if fzap_add() failed */
1041 zap_unlockdir(zap);
1042 return (err);
1043 }
1044
1045 int
1046 zap_update(objset_t *os, uint64_t zapobj, const char *name,
1047 int integer_size, uint64_t num_integers, const void *val, dmu_tx_t *tx)
1048 {
1049 zap_t *zap;
1050 mzap_ent_t *mze;
1051 uint64_t oldval;
1052 const uint64_t *intval = val;
1053 zap_name_t *zn;
1054 int err;
1055
1056 #ifdef ZFS_DEBUG
1057 /*
1058 * If there is an old value, it shouldn't change across the
1059 * lockdir (eg, due to bprewrite's xlation).
1060 */
1061 if (integer_size == 8 && num_integers == 1)
1062 (void) zap_lookup(os, zapobj, name, 8, 1, &oldval);
1063 #endif
1064
1065 err = zap_lockdir(os, zapobj, tx, RW_WRITER, TRUE, TRUE, &zap);
1066 if (err)
1067 return (err);
1068 zn = zap_name_alloc(zap, name, MT_EXACT);
1069 if (zn == NULL) {
1070 zap_unlockdir(zap);
1071 return (SET_ERROR(ENOTSUP));
1072 }
1073 if (!zap->zap_ismicro) {
1074 err = fzap_update(zn, integer_size, num_integers, val, tx);
1075 zap = zn->zn_zap; /* fzap_update() may change zap */
1076 } else if (integer_size != 8 || num_integers != 1 ||
1077 strlen(name) >= MZAP_NAME_LEN) {
1078 dprintf("upgrading obj %llu: intsz=%u numint=%llu name=%s\n",
1079 zapobj, integer_size, num_integers, name);
1080 err = mzap_upgrade(&zn->zn_zap, tx, 0);
1081 if (err == 0)
1082 err = fzap_update(zn, integer_size, num_integers,
1083 val, tx);
1084 zap = zn->zn_zap; /* fzap_update() may change zap */
1085 } else {
1086 mze = mze_find(zn);
1087 if (mze != NULL) {
1088 ASSERT3U(MZE_PHYS(zap, mze)->mze_value, ==, oldval);
1089 MZE_PHYS(zap, mze)->mze_value = *intval;
1090 } else {
1091 mzap_addent(zn, *intval);
1092 }
1093 }
1094 ASSERT(zap == zn->zn_zap);
1095 zap_name_free(zn);
1096 if (zap != NULL) /* may be NULL if fzap_upgrade() failed */
1097 zap_unlockdir(zap);
1098 return (err);
1099 }
1100
1101 int
1102 zap_update_uint64(objset_t *os, uint64_t zapobj, const uint64_t *key,
1103 int key_numints,
1104 int integer_size, uint64_t num_integers, const void *val, dmu_tx_t *tx)
1105 {
1106 zap_t *zap;
1107 zap_name_t *zn;
1108 int err;
1109
1110 err = zap_lockdir(os, zapobj, tx, RW_WRITER, TRUE, TRUE, &zap);
1111 if (err)
1112 return (err);
1113 zn = zap_name_alloc_uint64(zap, key, key_numints);
1114 if (zn == NULL) {
1115 zap_unlockdir(zap);
1116 return (SET_ERROR(ENOTSUP));
1117 }
1118 err = fzap_update(zn, integer_size, num_integers, val, tx);
1119 zap = zn->zn_zap; /* fzap_update() may change zap */
1120 zap_name_free(zn);
1121 if (zap != NULL) /* may be NULL if fzap_upgrade() failed */
1122 zap_unlockdir(zap);
1123 return (err);
1124 }
1125
1126 int
1127 zap_remove(objset_t *os, uint64_t zapobj, const char *name, dmu_tx_t *tx)
1128 {
1129 return (zap_remove_norm(os, zapobj, name, MT_EXACT, tx));
1130 }
1131
1132 int
1133 zap_remove_norm(objset_t *os, uint64_t zapobj, const char *name,
1134 matchtype_t mt, dmu_tx_t *tx)
1135 {
1136 zap_t *zap;
1137 int err;
1138 mzap_ent_t *mze;
1139 zap_name_t *zn;
1140
1141 err = zap_lockdir(os, zapobj, tx, RW_WRITER, TRUE, FALSE, &zap);
1142 if (err)
1143 return (err);
1144 zn = zap_name_alloc(zap, name, mt);
1145 if (zn == NULL) {
1146 zap_unlockdir(zap);
1147 return (SET_ERROR(ENOTSUP));
1148 }
1149 if (!zap->zap_ismicro) {
1150 err = fzap_remove(zn, tx);
1151 } else {
1152 mze = mze_find(zn);
1153 if (mze == NULL) {
1154 err = SET_ERROR(ENOENT);
1155 } else {
1156 zap->zap_m.zap_num_entries--;
1157 bzero(&zap_m_phys(zap)->mz_chunk[mze->mze_chunkid],
1158 sizeof (mzap_ent_phys_t));
1159 mze_remove(zap, mze);
1160 }
1161 }
1162 zap_name_free(zn);
1163 zap_unlockdir(zap);
1164 return (err);
1165 }
1166
1167 int
1168 zap_remove_uint64(objset_t *os, uint64_t zapobj, const uint64_t *key,
1169 int key_numints, dmu_tx_t *tx)
1170 {
1171 zap_t *zap;
1172 int err;
1173 zap_name_t *zn;
1174
1175 err = zap_lockdir(os, zapobj, tx, RW_WRITER, TRUE, FALSE, &zap);
1176 if (err)
1177 return (err);
1178 zn = zap_name_alloc_uint64(zap, key, key_numints);
1179 if (zn == NULL) {
1180 zap_unlockdir(zap);
1181 return (SET_ERROR(ENOTSUP));
1182 }
1183 err = fzap_remove(zn, tx);
1184 zap_name_free(zn);
1185 zap_unlockdir(zap);
1186 return (err);
1187 }
1188
1189 /*
1190 * Routines for iterating over the attributes.
1191 */
1192
1193 void
1194 zap_cursor_init_serialized(zap_cursor_t *zc, objset_t *os, uint64_t zapobj,
1195 uint64_t serialized)
1196 {
1197 zc->zc_objset = os;
1198 zc->zc_zap = NULL;
1199 zc->zc_leaf = NULL;
1200 zc->zc_zapobj = zapobj;
1201 zc->zc_serialized = serialized;
1202 zc->zc_hash = 0;
1203 zc->zc_cd = 0;
1204 }
1205
1206 void
1207 zap_cursor_init(zap_cursor_t *zc, objset_t *os, uint64_t zapobj)
1208 {
1209 zap_cursor_init_serialized(zc, os, zapobj, 0);
1210 }
1211
1212 void
1213 zap_cursor_fini(zap_cursor_t *zc)
1214 {
1215 if (zc->zc_zap) {
1216 rw_enter(&zc->zc_zap->zap_rwlock, RW_READER);
1217 zap_unlockdir(zc->zc_zap);
1218 zc->zc_zap = NULL;
1219 }
1220 if (zc->zc_leaf) {
1221 rw_enter(&zc->zc_leaf->l_rwlock, RW_READER);
1222 zap_put_leaf(zc->zc_leaf);
1223 zc->zc_leaf = NULL;
1224 }
1225 zc->zc_objset = NULL;
1226 }
1227
1228 uint64_t
1229 zap_cursor_serialize(zap_cursor_t *zc)
1230 {
1231 if (zc->zc_hash == -1ULL)
1232 return (-1ULL);
1233 if (zc->zc_zap == NULL)
1234 return (zc->zc_serialized);
1235 ASSERT((zc->zc_hash & zap_maxcd(zc->zc_zap)) == 0);
1236 ASSERT(zc->zc_cd < zap_maxcd(zc->zc_zap));
1237
1238 /*
1239 * We want to keep the high 32 bits of the cursor zero if we can, so
1240 * that 32-bit programs can access this. So usually use a small
1241 * (28-bit) hash value so we can fit 4 bits of cd into the low 32-bits
1242 * of the cursor.
1243 *
1244 * [ collision differentiator | zap_hashbits()-bit hash value ]
1245 */
1246 return ((zc->zc_hash >> (64 - zap_hashbits(zc->zc_zap))) |
1247 ((uint64_t)zc->zc_cd << zap_hashbits(zc->zc_zap)));
1248 }
1249
1250 int
1251 zap_cursor_retrieve(zap_cursor_t *zc, zap_attribute_t *za)
1252 {
1253 int err;
1254 avl_index_t idx;
1255 mzap_ent_t mze_tofind;
1256 mzap_ent_t *mze;
1257
1258 if (zc->zc_hash == -1ULL)
1259 return (SET_ERROR(ENOENT));
1260
1261 if (zc->zc_zap == NULL) {
1262 int hb;
1263 err = zap_lockdir(zc->zc_objset, zc->zc_zapobj, NULL,
1264 RW_READER, TRUE, FALSE, &zc->zc_zap);
1265 if (err)
1266 return (err);
1267
1268 /*
1269 * To support zap_cursor_init_serialized, advance, retrieve,
1270 * we must add to the existing zc_cd, which may already
1271 * be 1 due to the zap_cursor_advance.
1272 */
1273 ASSERT(zc->zc_hash == 0);
1274 hb = zap_hashbits(zc->zc_zap);
1275 zc->zc_hash = zc->zc_serialized << (64 - hb);
1276 zc->zc_cd += zc->zc_serialized >> hb;
1277 if (zc->zc_cd >= zap_maxcd(zc->zc_zap)) /* corrupt serialized */
1278 zc->zc_cd = 0;
1279 } else {
1280 rw_enter(&zc->zc_zap->zap_rwlock, RW_READER);
1281 }
1282 if (!zc->zc_zap->zap_ismicro) {
1283 err = fzap_cursor_retrieve(zc->zc_zap, zc, za);
1284 } else {
1285 mze_tofind.mze_hash = zc->zc_hash;
1286 mze_tofind.mze_cd = zc->zc_cd;
1287
1288 mze = avl_find(&zc->zc_zap->zap_m.zap_avl, &mze_tofind, &idx);
1289 if (mze == NULL) {
1290 mze = avl_nearest(&zc->zc_zap->zap_m.zap_avl,
1291 idx, AVL_AFTER);
1292 }
1293 if (mze) {
1294 mzap_ent_phys_t *mzep = MZE_PHYS(zc->zc_zap, mze);
1295 ASSERT3U(mze->mze_cd, ==, mzep->mze_cd);
1296 za->za_normalization_conflict =
1297 mzap_normalization_conflict(zc->zc_zap, NULL, mze);
1298 za->za_integer_length = 8;
1299 za->za_num_integers = 1;
1300 za->za_first_integer = mzep->mze_value;
1301 (void) strcpy(za->za_name, mzep->mze_name);
1302 zc->zc_hash = mze->mze_hash;
1303 zc->zc_cd = mze->mze_cd;
1304 err = 0;
1305 } else {
1306 zc->zc_hash = -1ULL;
1307 err = SET_ERROR(ENOENT);
1308 }
1309 }
1310 rw_exit(&zc->zc_zap->zap_rwlock);
1311 return (err);
1312 }
1313
1314 void
1315 zap_cursor_advance(zap_cursor_t *zc)
1316 {
1317 if (zc->zc_hash == -1ULL)
1318 return;
1319 zc->zc_cd++;
1320 }
1321
1322 int
1323 zap_get_stats(objset_t *os, uint64_t zapobj, zap_stats_t *zs)
1324 {
1325 int err;
1326 zap_t *zap;
1327
1328 err = zap_lockdir(os, zapobj, NULL, RW_READER, TRUE, FALSE, &zap);
1329 if (err)
1330 return (err);
1331
1332 bzero(zs, sizeof (zap_stats_t));
1333
1334 if (zap->zap_ismicro) {
1335 zs->zs_blocksize = zap->zap_dbuf->db_size;
1336 zs->zs_num_entries = zap->zap_m.zap_num_entries;
1337 zs->zs_num_blocks = 1;
1338 } else {
1339 fzap_get_stats(zap, zs);
1340 }
1341 zap_unlockdir(zap);
1342 return (0);
1343 }
1344
1345 int
1346 zap_count_write(objset_t *os, uint64_t zapobj, const char *name, int add,
1347 uint64_t *towrite, uint64_t *tooverwrite)
1348 {
1349 zap_t *zap;
1350 int err = 0;
1351
1352 /*
1353 * Since, we don't have a name, we cannot figure out which blocks will
1354 * be affected in this operation. So, account for the worst case :
1355 * - 3 blocks overwritten: target leaf, ptrtbl block, header block
1356 * - 4 new blocks written if adding:
1357 * - 2 blocks for possibly split leaves,
1358 * - 2 grown ptrtbl blocks
1359 *
1360 * This also accomodates the case where an add operation to a fairly
1361 * large microzap results in a promotion to fatzap.
1362 */
1363 if (name == NULL) {
1364 *towrite += (3 + (add ? 4 : 0)) * SPA_OLD_MAXBLOCKSIZE;
1365 return (err);
1366 }
1367
1368 /*
1369 * We lock the zap with adding == FALSE. Because, if we pass
1370 * the actual value of add, it could trigger a mzap_upgrade().
1371 * At present we are just evaluating the possibility of this operation
1372 * and hence we donot want to trigger an upgrade.
1373 */
1374 err = zap_lockdir(os, zapobj, NULL, RW_READER, TRUE, FALSE, &zap);
1375 if (err)
1376 return (err);
1377
1378 if (!zap->zap_ismicro) {
1379 zap_name_t *zn = zap_name_alloc(zap, name, MT_EXACT);
1380 if (zn) {
1381 err = fzap_count_write(zn, add, towrite,
1382 tooverwrite);
1383 zap_name_free(zn);
1384 } else {
1385 /*
1386 * We treat this case as similar to (name == NULL)
1387 */
1388 *towrite += (3 + (add ? 4 : 0)) * SPA_OLD_MAXBLOCKSIZE;
1389 }
1390 } else {
1391 /*
1392 * We are here if (name != NULL) and this is a micro-zap.
1393 * We account for the header block depending on whether it
1394 * is freeable.
1395 *
1396 * Incase of an add-operation it is hard to find out
1397 * if this add will promote this microzap to fatzap.
1398 * Hence, we consider the worst case and account for the
1399 * blocks assuming this microzap would be promoted to a
1400 * fatzap.
1401 *
1402 * 1 block overwritten : header block
1403 * 4 new blocks written : 2 new split leaf, 2 grown
1404 * ptrtbl blocks
1405 */
1406 if (dmu_buf_freeable(zap->zap_dbuf))
1407 *tooverwrite += MZAP_MAX_BLKSZ;
1408 else
1409 *towrite += MZAP_MAX_BLKSZ;
1410
1411 if (add) {
1412 *towrite += 4 * MZAP_MAX_BLKSZ;
1413 }
1414 }
1415
1416 zap_unlockdir(zap);
1417 return (err);
1418 }
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