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 /*
27 * This file contains the top half of the zfs directory structure
28 * implementation. The bottom half is in zap_leaf.c.
29 *
30 * The zdir is an extendable hash data structure. There is a table of
31 * pointers to buckets (zap_t->zd_data->zd_leafs). The buckets are
32 * each a constant size and hold a variable number of directory entries.
33 * The buckets (aka "leaf nodes") are implemented in zap_leaf.c.
34 *
35 * The pointer table holds a power of 2 number of pointers.
36 * (1<<zap_t->zd_data->zd_phys->zd_prefix_len). The bucket pointed to
37 * by the pointer at index i in the table holds entries whose hash value
38 * has a zd_prefix_len - bit prefix
39 */
40
41 #include <sys/spa.h>
42 #include <sys/dmu.h>
43 #include <sys/zfs_context.h>
44 #include <sys/zfs_znode.h>
45 #include <sys/fs/zfs.h>
46 #include <sys/zap.h>
47 #include <sys/refcount.h>
48 #include <sys/zap_impl.h>
49 #include <sys/zap_leaf.h>
50
51 int fzap_default_block_shift = 14; /* 16k blocksize */
52
53 static void zap_leaf_pageout(dmu_buf_t *db, void *vl);
54 static uint64_t zap_allocate_blocks(zap_t *zap, int nblocks);
55
56
57 void
58 fzap_byteswap(void *vbuf, size_t size)
59 {
60 uint64_t block_type;
61
62 block_type = *(uint64_t *)vbuf;
63
64 if (block_type == ZBT_LEAF || block_type == BSWAP_64(ZBT_LEAF))
65 zap_leaf_byteswap(vbuf, size);
66 else {
67 /* it's a ptrtbl block */
68 byteswap_uint64_array(vbuf, size);
69 }
70 }
71
72 void
73 fzap_upgrade(zap_t *zap, dmu_tx_t *tx, zap_flags_t flags)
74 {
75 dmu_buf_t *db;
76 zap_leaf_t *l;
77 int i;
78 zap_phys_t *zp;
79
80 ASSERT(RW_WRITE_HELD(&zap->zap_rwlock));
81 zap->zap_ismicro = FALSE;
82
83 (void) dmu_buf_update_user(zap->zap_dbuf, zap, zap,
84 &zap->zap_f.zap_phys, zap_evict);
85
86 mutex_init(&zap->zap_f.zap_num_entries_mtx, 0, 0, 0);
87 zap->zap_f.zap_block_shift = highbit(zap->zap_dbuf->db_size) - 1;
88
89 zp = zap->zap_f.zap_phys;
90 /*
91 * explicitly zero it since it might be coming from an
92 * initialized microzap
93 */
94 bzero(zap->zap_dbuf->db_data, zap->zap_dbuf->db_size);
95 zp->zap_block_type = ZBT_HEADER;
96 zp->zap_magic = ZAP_MAGIC;
97
98 zp->zap_ptrtbl.zt_shift = ZAP_EMBEDDED_PTRTBL_SHIFT(zap);
99
100 zp->zap_freeblk = 2; /* block 1 will be the first leaf */
101 zp->zap_num_leafs = 1;
102 zp->zap_num_entries = 0;
103 zp->zap_salt = zap->zap_salt;
104 zp->zap_normflags = zap->zap_normflags;
105 zp->zap_flags = flags;
106
107 /* block 1 will be the first leaf */
108 for (i = 0; i < (1<<zp->zap_ptrtbl.zt_shift); i++)
109 ZAP_EMBEDDED_PTRTBL_ENT(zap, i) = 1;
110
111 /*
112 * set up block 1 - the first leaf
113 */
114 VERIFY(0 == dmu_buf_hold(zap->zap_objset, zap->zap_object,
115 1<<FZAP_BLOCK_SHIFT(zap), FTAG, &db, DMU_READ_NO_PREFETCH));
116 dmu_buf_will_dirty(db, tx);
117
118 l = kmem_zalloc(sizeof (zap_leaf_t), KM_SLEEP);
119 l->l_dbuf = db;
120 l->l_phys = db->db_data;
121
122 zap_leaf_init(l, zp->zap_normflags != 0);
123
124 kmem_free(l, sizeof (zap_leaf_t));
125 dmu_buf_rele(db, FTAG);
126 }
127
128 static int
129 zap_tryupgradedir(zap_t *zap, dmu_tx_t *tx)
130 {
131 if (RW_WRITE_HELD(&zap->zap_rwlock))
132 return (1);
133 if (rw_tryupgrade(&zap->zap_rwlock)) {
134 dmu_buf_will_dirty(zap->zap_dbuf, tx);
135 return (1);
136 }
137 return (0);
138 }
139
140 /*
141 * Generic routines for dealing with the pointer & cookie tables.
142 */
143
144 static int
145 zap_table_grow(zap_t *zap, zap_table_phys_t *tbl,
146 void (*transfer_func)(const uint64_t *src, uint64_t *dst, int n),
147 dmu_tx_t *tx)
148 {
149 uint64_t b, newblk;
150 dmu_buf_t *db_old, *db_new;
151 int err;
152 int bs = FZAP_BLOCK_SHIFT(zap);
153 int hepb = 1<<(bs-4);
154 /* hepb = half the number of entries in a block */
155
156 ASSERT(RW_WRITE_HELD(&zap->zap_rwlock));
157 ASSERT(tbl->zt_blk != 0);
158 ASSERT(tbl->zt_numblks > 0);
159
160 if (tbl->zt_nextblk != 0) {
161 newblk = tbl->zt_nextblk;
162 } else {
163 newblk = zap_allocate_blocks(zap, tbl->zt_numblks * 2);
164 tbl->zt_nextblk = newblk;
165 ASSERT0(tbl->zt_blks_copied);
166 dmu_prefetch(zap->zap_objset, zap->zap_object,
167 tbl->zt_blk << bs, tbl->zt_numblks << bs);
168 }
169
170 /*
171 * Copy the ptrtbl from the old to new location.
172 */
173
174 b = tbl->zt_blks_copied;
175 err = dmu_buf_hold(zap->zap_objset, zap->zap_object,
176 (tbl->zt_blk + b) << bs, FTAG, &db_old, DMU_READ_NO_PREFETCH);
177 if (err)
178 return (err);
179
180 /* first half of entries in old[b] go to new[2*b+0] */
181 VERIFY(0 == dmu_buf_hold(zap->zap_objset, zap->zap_object,
182 (newblk + 2*b+0) << bs, FTAG, &db_new, DMU_READ_NO_PREFETCH));
183 dmu_buf_will_dirty(db_new, tx);
184 transfer_func(db_old->db_data, db_new->db_data, hepb);
185 dmu_buf_rele(db_new, FTAG);
186
187 /* second half of entries in old[b] go to new[2*b+1] */
188 VERIFY(0 == dmu_buf_hold(zap->zap_objset, zap->zap_object,
189 (newblk + 2*b+1) << bs, FTAG, &db_new, DMU_READ_NO_PREFETCH));
190 dmu_buf_will_dirty(db_new, tx);
191 transfer_func((uint64_t *)db_old->db_data + hepb,
192 db_new->db_data, hepb);
193 dmu_buf_rele(db_new, FTAG);
194
195 dmu_buf_rele(db_old, FTAG);
196
197 tbl->zt_blks_copied++;
198
199 dprintf("copied block %llu of %llu\n",
200 tbl->zt_blks_copied, tbl->zt_numblks);
201
202 if (tbl->zt_blks_copied == tbl->zt_numblks) {
203 (void) dmu_free_range(zap->zap_objset, zap->zap_object,
204 tbl->zt_blk << bs, tbl->zt_numblks << bs, tx);
205
206 tbl->zt_blk = newblk;
207 tbl->zt_numblks *= 2;
208 tbl->zt_shift++;
209 tbl->zt_nextblk = 0;
210 tbl->zt_blks_copied = 0;
211
212 dprintf("finished; numblocks now %llu (%lluk entries)\n",
213 tbl->zt_numblks, 1<<(tbl->zt_shift-10));
214 }
215
216 return (0);
217 }
218
219 static int
220 zap_table_store(zap_t *zap, zap_table_phys_t *tbl, uint64_t idx, uint64_t val,
221 dmu_tx_t *tx)
222 {
223 int err;
224 uint64_t blk, off;
225 int bs = FZAP_BLOCK_SHIFT(zap);
226 dmu_buf_t *db;
227
228 ASSERT(RW_LOCK_HELD(&zap->zap_rwlock));
229 ASSERT(tbl->zt_blk != 0);
230
231 dprintf("storing %llx at index %llx\n", val, idx);
232
233 blk = idx >> (bs-3);
234 off = idx & ((1<<(bs-3))-1);
235
236 err = dmu_buf_hold(zap->zap_objset, zap->zap_object,
237 (tbl->zt_blk + blk) << bs, FTAG, &db, DMU_READ_NO_PREFETCH);
238 if (err)
239 return (err);
240 dmu_buf_will_dirty(db, tx);
241
242 if (tbl->zt_nextblk != 0) {
243 uint64_t idx2 = idx * 2;
244 uint64_t blk2 = idx2 >> (bs-3);
245 uint64_t off2 = idx2 & ((1<<(bs-3))-1);
246 dmu_buf_t *db2;
247
248 err = dmu_buf_hold(zap->zap_objset, zap->zap_object,
249 (tbl->zt_nextblk + blk2) << bs, FTAG, &db2,
250 DMU_READ_NO_PREFETCH);
251 if (err) {
252 dmu_buf_rele(db, FTAG);
253 return (err);
254 }
255 dmu_buf_will_dirty(db2, tx);
256 ((uint64_t *)db2->db_data)[off2] = val;
257 ((uint64_t *)db2->db_data)[off2+1] = val;
258 dmu_buf_rele(db2, FTAG);
259 }
260
261 ((uint64_t *)db->db_data)[off] = val;
262 dmu_buf_rele(db, FTAG);
263
264 return (0);
265 }
266
267 static int
268 zap_table_load(zap_t *zap, zap_table_phys_t *tbl, uint64_t idx, uint64_t *valp)
269 {
270 uint64_t blk, off;
271 int err;
272 dmu_buf_t *db;
273 int bs = FZAP_BLOCK_SHIFT(zap);
274
275 ASSERT(RW_LOCK_HELD(&zap->zap_rwlock));
276
277 blk = idx >> (bs-3);
278 off = idx & ((1<<(bs-3))-1);
279
280 err = dmu_buf_hold(zap->zap_objset, zap->zap_object,
281 (tbl->zt_blk + blk) << bs, FTAG, &db, DMU_READ_NO_PREFETCH);
282 if (err)
283 return (err);
284 *valp = ((uint64_t *)db->db_data)[off];
285 dmu_buf_rele(db, FTAG);
286
287 if (tbl->zt_nextblk != 0) {
288 /*
289 * read the nextblk for the sake of i/o error checking,
290 * so that zap_table_load() will catch errors for
291 * zap_table_store.
292 */
293 blk = (idx*2) >> (bs-3);
294
295 err = dmu_buf_hold(zap->zap_objset, zap->zap_object,
296 (tbl->zt_nextblk + blk) << bs, FTAG, &db,
297 DMU_READ_NO_PREFETCH);
298 dmu_buf_rele(db, FTAG);
299 }
300 return (err);
301 }
302
303 /*
304 * Routines for growing the ptrtbl.
305 */
306
307 static void
308 zap_ptrtbl_transfer(const uint64_t *src, uint64_t *dst, int n)
309 {
310 int i;
311 for (i = 0; i < n; i++) {
312 uint64_t lb = src[i];
313 dst[2*i+0] = lb;
314 dst[2*i+1] = lb;
315 }
316 }
317
318 static int
319 zap_grow_ptrtbl(zap_t *zap, dmu_tx_t *tx)
320 {
321 /*
322 * The pointer table should never use more hash bits than we
323 * have (otherwise we'd be using useless zero bits to index it).
324 * If we are within 2 bits of running out, stop growing, since
325 * this is already an aberrant condition.
326 */
327 if (zap->zap_f.zap_phys->zap_ptrtbl.zt_shift >= zap_hashbits(zap) - 2)
328 return (ENOSPC);
329
330 if (zap->zap_f.zap_phys->zap_ptrtbl.zt_numblks == 0) {
331 /*
332 * We are outgrowing the "embedded" ptrtbl (the one
333 * stored in the header block). Give it its own entire
334 * block, which will double the size of the ptrtbl.
335 */
336 uint64_t newblk;
337 dmu_buf_t *db_new;
338 int err;
339
340 ASSERT3U(zap->zap_f.zap_phys->zap_ptrtbl.zt_shift, ==,
341 ZAP_EMBEDDED_PTRTBL_SHIFT(zap));
342 ASSERT0(zap->zap_f.zap_phys->zap_ptrtbl.zt_blk);
343
344 newblk = zap_allocate_blocks(zap, 1);
345 err = dmu_buf_hold(zap->zap_objset, zap->zap_object,
346 newblk << FZAP_BLOCK_SHIFT(zap), FTAG, &db_new,
347 DMU_READ_NO_PREFETCH);
348 if (err)
349 return (err);
350 dmu_buf_will_dirty(db_new, tx);
351 zap_ptrtbl_transfer(&ZAP_EMBEDDED_PTRTBL_ENT(zap, 0),
352 db_new->db_data, 1 << ZAP_EMBEDDED_PTRTBL_SHIFT(zap));
353 dmu_buf_rele(db_new, FTAG);
354
355 zap->zap_f.zap_phys->zap_ptrtbl.zt_blk = newblk;
356 zap->zap_f.zap_phys->zap_ptrtbl.zt_numblks = 1;
357 zap->zap_f.zap_phys->zap_ptrtbl.zt_shift++;
358
359 ASSERT3U(1ULL << zap->zap_f.zap_phys->zap_ptrtbl.zt_shift, ==,
360 zap->zap_f.zap_phys->zap_ptrtbl.zt_numblks <<
361 (FZAP_BLOCK_SHIFT(zap)-3));
362
363 return (0);
364 } else {
365 return (zap_table_grow(zap, &zap->zap_f.zap_phys->zap_ptrtbl,
366 zap_ptrtbl_transfer, tx));
367 }
368 }
369
370 static void
371 zap_increment_num_entries(zap_t *zap, int delta, dmu_tx_t *tx)
372 {
373 dmu_buf_will_dirty(zap->zap_dbuf, tx);
374 mutex_enter(&zap->zap_f.zap_num_entries_mtx);
375 ASSERT(delta > 0 || zap->zap_f.zap_phys->zap_num_entries >= -delta);
376 zap->zap_f.zap_phys->zap_num_entries += delta;
377 mutex_exit(&zap->zap_f.zap_num_entries_mtx);
378 }
379
380 static uint64_t
381 zap_allocate_blocks(zap_t *zap, int nblocks)
382 {
383 uint64_t newblk;
384 ASSERT(RW_WRITE_HELD(&zap->zap_rwlock));
385 newblk = zap->zap_f.zap_phys->zap_freeblk;
386 zap->zap_f.zap_phys->zap_freeblk += nblocks;
387 return (newblk);
388 }
389
390 static zap_leaf_t *
391 zap_create_leaf(zap_t *zap, dmu_tx_t *tx)
392 {
393 void *winner;
394 zap_leaf_t *l = kmem_alloc(sizeof (zap_leaf_t), KM_SLEEP);
395
396 ASSERT(RW_WRITE_HELD(&zap->zap_rwlock));
397
398 rw_init(&l->l_rwlock, 0, 0, 0);
399 rw_enter(&l->l_rwlock, RW_WRITER);
400 l->l_blkid = zap_allocate_blocks(zap, 1);
401 l->l_dbuf = NULL;
402 l->l_phys = NULL;
403
404 VERIFY(0 == dmu_buf_hold(zap->zap_objset, zap->zap_object,
405 l->l_blkid << FZAP_BLOCK_SHIFT(zap), NULL, &l->l_dbuf,
406 DMU_READ_NO_PREFETCH));
407 winner = dmu_buf_set_user(l->l_dbuf, l, &l->l_phys, zap_leaf_pageout);
408 ASSERT(winner == NULL);
409 dmu_buf_will_dirty(l->l_dbuf, tx);
410
411 zap_leaf_init(l, zap->zap_normflags != 0);
412
413 zap->zap_f.zap_phys->zap_num_leafs++;
414
415 return (l);
416 }
417
418 int
419 fzap_count(zap_t *zap, uint64_t *count)
420 {
421 ASSERT(!zap->zap_ismicro);
422 mutex_enter(&zap->zap_f.zap_num_entries_mtx); /* unnecessary */
423 *count = zap->zap_f.zap_phys->zap_num_entries;
424 mutex_exit(&zap->zap_f.zap_num_entries_mtx);
425 return (0);
426 }
427
428 /*
429 * Routines for obtaining zap_leaf_t's
430 */
431
432 void
433 zap_put_leaf(zap_leaf_t *l)
434 {
435 rw_exit(&l->l_rwlock);
436 dmu_buf_rele(l->l_dbuf, NULL);
437 }
438
439 _NOTE(ARGSUSED(0))
440 static void
441 zap_leaf_pageout(dmu_buf_t *db, void *vl)
442 {
443 zap_leaf_t *l = vl;
444
445 rw_destroy(&l->l_rwlock);
446 kmem_free(l, sizeof (zap_leaf_t));
447 }
448
449 static zap_leaf_t *
450 zap_open_leaf(uint64_t blkid, dmu_buf_t *db)
451 {
452 zap_leaf_t *l, *winner;
453
454 ASSERT(blkid != 0);
455
456 l = kmem_alloc(sizeof (zap_leaf_t), KM_SLEEP);
457 rw_init(&l->l_rwlock, 0, 0, 0);
458 rw_enter(&l->l_rwlock, RW_WRITER);
459 l->l_blkid = blkid;
460 l->l_bs = highbit(db->db_size)-1;
461 l->l_dbuf = db;
462 l->l_phys = NULL;
463
464 winner = dmu_buf_set_user(db, l, &l->l_phys, zap_leaf_pageout);
465
466 rw_exit(&l->l_rwlock);
467 if (winner != NULL) {
468 /* someone else set it first */
469 zap_leaf_pageout(NULL, l);
470 l = winner;
471 }
472
473 /*
474 * lhr_pad was previously used for the next leaf in the leaf
475 * chain. There should be no chained leafs (as we have removed
476 * support for them).
477 */
478 ASSERT0(l->l_phys->l_hdr.lh_pad1);
479
480 /*
481 * There should be more hash entries than there can be
482 * chunks to put in the hash table
483 */
484 ASSERT3U(ZAP_LEAF_HASH_NUMENTRIES(l), >, ZAP_LEAF_NUMCHUNKS(l) / 3);
485
486 /* The chunks should begin at the end of the hash table */
487 ASSERT3P(&ZAP_LEAF_CHUNK(l, 0), ==,
488 &l->l_phys->l_hash[ZAP_LEAF_HASH_NUMENTRIES(l)]);
489
490 /* The chunks should end at the end of the block */
491 ASSERT3U((uintptr_t)&ZAP_LEAF_CHUNK(l, ZAP_LEAF_NUMCHUNKS(l)) -
492 (uintptr_t)l->l_phys, ==, l->l_dbuf->db_size);
493
494 return (l);
495 }
496
497 static int
498 zap_get_leaf_byblk(zap_t *zap, uint64_t blkid, dmu_tx_t *tx, krw_t lt,
499 zap_leaf_t **lp)
500 {
501 dmu_buf_t *db;
502 zap_leaf_t *l;
503 int bs = FZAP_BLOCK_SHIFT(zap);
504 int err;
505
506 ASSERT(RW_LOCK_HELD(&zap->zap_rwlock));
507
508 err = dmu_buf_hold(zap->zap_objset, zap->zap_object,
509 blkid << bs, NULL, &db, DMU_READ_NO_PREFETCH);
510 if (err)
511 return (err);
512
513 ASSERT3U(db->db_object, ==, zap->zap_object);
514 ASSERT3U(db->db_offset, ==, blkid << bs);
515 ASSERT3U(db->db_size, ==, 1 << bs);
516 ASSERT(blkid != 0);
517
518 l = dmu_buf_get_user(db);
519
520 if (l == NULL)
521 l = zap_open_leaf(blkid, db);
522
523 rw_enter(&l->l_rwlock, lt);
524 /*
525 * Must lock before dirtying, otherwise l->l_phys could change,
526 * causing ASSERT below to fail.
527 */
528 if (lt == RW_WRITER)
529 dmu_buf_will_dirty(db, tx);
530 ASSERT3U(l->l_blkid, ==, blkid);
531 ASSERT3P(l->l_dbuf, ==, db);
532 ASSERT3P(l->l_phys, ==, l->l_dbuf->db_data);
533 ASSERT3U(l->l_phys->l_hdr.lh_block_type, ==, ZBT_LEAF);
534 ASSERT3U(l->l_phys->l_hdr.lh_magic, ==, ZAP_LEAF_MAGIC);
535
536 *lp = l;
537 return (0);
538 }
539
540 static int
541 zap_idx_to_blk(zap_t *zap, uint64_t idx, uint64_t *valp)
542 {
543 ASSERT(RW_LOCK_HELD(&zap->zap_rwlock));
544
545 if (zap->zap_f.zap_phys->zap_ptrtbl.zt_numblks == 0) {
546 ASSERT3U(idx, <,
547 (1ULL << zap->zap_f.zap_phys->zap_ptrtbl.zt_shift));
548 *valp = ZAP_EMBEDDED_PTRTBL_ENT(zap, idx);
549 return (0);
550 } else {
551 return (zap_table_load(zap, &zap->zap_f.zap_phys->zap_ptrtbl,
552 idx, valp));
553 }
554 }
555
556 static int
557 zap_set_idx_to_blk(zap_t *zap, uint64_t idx, uint64_t blk, dmu_tx_t *tx)
558 {
559 ASSERT(tx != NULL);
560 ASSERT(RW_WRITE_HELD(&zap->zap_rwlock));
561
562 if (zap->zap_f.zap_phys->zap_ptrtbl.zt_blk == 0) {
563 ZAP_EMBEDDED_PTRTBL_ENT(zap, idx) = blk;
564 return (0);
565 } else {
566 return (zap_table_store(zap, &zap->zap_f.zap_phys->zap_ptrtbl,
567 idx, blk, tx));
568 }
569 }
570
571 static int
572 zap_deref_leaf(zap_t *zap, uint64_t h, dmu_tx_t *tx, krw_t lt, zap_leaf_t **lp)
573 {
574 uint64_t idx, blk;
575 int err;
576
577 ASSERT(zap->zap_dbuf == NULL ||
578 zap->zap_f.zap_phys == zap->zap_dbuf->db_data);
579 ASSERT3U(zap->zap_f.zap_phys->zap_magic, ==, ZAP_MAGIC);
580 idx = ZAP_HASH_IDX(h, zap->zap_f.zap_phys->zap_ptrtbl.zt_shift);
581 err = zap_idx_to_blk(zap, idx, &blk);
582 if (err != 0)
583 return (err);
584 err = zap_get_leaf_byblk(zap, blk, tx, lt, lp);
585
586 ASSERT(err || ZAP_HASH_IDX(h, (*lp)->l_phys->l_hdr.lh_prefix_len) ==
587 (*lp)->l_phys->l_hdr.lh_prefix);
588 return (err);
589 }
590
591 static int
592 zap_expand_leaf(zap_name_t *zn, zap_leaf_t *l, dmu_tx_t *tx, zap_leaf_t **lp)
593 {
594 zap_t *zap = zn->zn_zap;
595 uint64_t hash = zn->zn_hash;
596 zap_leaf_t *nl;
597 int prefix_diff, i, err;
598 uint64_t sibling;
599 int old_prefix_len = l->l_phys->l_hdr.lh_prefix_len;
600
601 ASSERT3U(old_prefix_len, <=, zap->zap_f.zap_phys->zap_ptrtbl.zt_shift);
602 ASSERT(RW_LOCK_HELD(&zap->zap_rwlock));
603
604 ASSERT3U(ZAP_HASH_IDX(hash, old_prefix_len), ==,
605 l->l_phys->l_hdr.lh_prefix);
606
607 if (zap_tryupgradedir(zap, tx) == 0 ||
608 old_prefix_len == zap->zap_f.zap_phys->zap_ptrtbl.zt_shift) {
609 /* We failed to upgrade, or need to grow the pointer table */
610 objset_t *os = zap->zap_objset;
611 uint64_t object = zap->zap_object;
612
613 zap_put_leaf(l);
614 zap_unlockdir(zap);
615 err = zap_lockdir(os, object, tx, RW_WRITER,
616 FALSE, FALSE, &zn->zn_zap);
617 zap = zn->zn_zap;
618 if (err)
619 return (err);
620 ASSERT(!zap->zap_ismicro);
621
622 while (old_prefix_len ==
623 zap->zap_f.zap_phys->zap_ptrtbl.zt_shift) {
624 err = zap_grow_ptrtbl(zap, tx);
625 if (err)
626 return (err);
627 }
628
629 err = zap_deref_leaf(zap, hash, tx, RW_WRITER, &l);
630 if (err)
631 return (err);
632
633 if (l->l_phys->l_hdr.lh_prefix_len != old_prefix_len) {
634 /* it split while our locks were down */
635 *lp = l;
636 return (0);
637 }
638 }
639 ASSERT(RW_WRITE_HELD(&zap->zap_rwlock));
640 ASSERT3U(old_prefix_len, <, zap->zap_f.zap_phys->zap_ptrtbl.zt_shift);
641 ASSERT3U(ZAP_HASH_IDX(hash, old_prefix_len), ==,
642 l->l_phys->l_hdr.lh_prefix);
643
644 prefix_diff = zap->zap_f.zap_phys->zap_ptrtbl.zt_shift -
645 (old_prefix_len + 1);
646 sibling = (ZAP_HASH_IDX(hash, old_prefix_len + 1) | 1) << prefix_diff;
647
648 /* check for i/o errors before doing zap_leaf_split */
649 for (i = 0; i < (1ULL<<prefix_diff); i++) {
650 uint64_t blk;
651 err = zap_idx_to_blk(zap, sibling+i, &blk);
652 if (err)
653 return (err);
654 ASSERT3U(blk, ==, l->l_blkid);
655 }
656
657 nl = zap_create_leaf(zap, tx);
658 zap_leaf_split(l, nl, zap->zap_normflags != 0);
659
660 /* set sibling pointers */
661 for (i = 0; i < (1ULL << prefix_diff); i++) {
662 err = zap_set_idx_to_blk(zap, sibling+i, nl->l_blkid, tx);
663 ASSERT0(err); /* we checked for i/o errors above */
664 }
665
666 if (hash & (1ULL << (64 - l->l_phys->l_hdr.lh_prefix_len))) {
667 /* we want the sibling */
668 zap_put_leaf(l);
669 *lp = nl;
670 } else {
671 zap_put_leaf(nl);
672 *lp = l;
673 }
674
675 return (0);
676 }
677
678 static void
679 zap_put_leaf_maybe_grow_ptrtbl(zap_name_t *zn, zap_leaf_t *l, dmu_tx_t *tx)
680 {
681 zap_t *zap = zn->zn_zap;
682 int shift = zap->zap_f.zap_phys->zap_ptrtbl.zt_shift;
683 int leaffull = (l->l_phys->l_hdr.lh_prefix_len == shift &&
684 l->l_phys->l_hdr.lh_nfree < ZAP_LEAF_LOW_WATER);
685
686 zap_put_leaf(l);
687
688 if (leaffull || zap->zap_f.zap_phys->zap_ptrtbl.zt_nextblk) {
689 int err;
690
691 /*
692 * We are in the middle of growing the pointer table, or
693 * this leaf will soon make us grow it.
694 */
695 if (zap_tryupgradedir(zap, tx) == 0) {
696 objset_t *os = zap->zap_objset;
697 uint64_t zapobj = zap->zap_object;
698
699 zap_unlockdir(zap);
700 err = zap_lockdir(os, zapobj, tx,
701 RW_WRITER, FALSE, FALSE, &zn->zn_zap);
702 zap = zn->zn_zap;
703 if (err)
704 return;
705 }
706
707 /* could have finished growing while our locks were down */
708 if (zap->zap_f.zap_phys->zap_ptrtbl.zt_shift == shift)
709 (void) zap_grow_ptrtbl(zap, tx);
710 }
711 }
712
713 static int
714 fzap_checkname(zap_name_t *zn)
715 {
716 if (zn->zn_key_orig_numints * zn->zn_key_intlen > ZAP_MAXNAMELEN)
717 return (ENAMETOOLONG);
718 return (0);
719 }
720
721 static int
722 fzap_checksize(uint64_t integer_size, uint64_t num_integers)
723 {
724 /* Only integer sizes supported by C */
725 switch (integer_size) {
726 case 1:
727 case 2:
728 case 4:
729 case 8:
730 break;
731 default:
732 return (EINVAL);
733 }
734
735 if (integer_size * num_integers > ZAP_MAXVALUELEN)
736 return (E2BIG);
737
738 return (0);
739 }
740
741 static int
742 fzap_check(zap_name_t *zn, uint64_t integer_size, uint64_t num_integers)
743 {
744 int err;
745
746 if ((err = fzap_checkname(zn)) != 0)
747 return (err);
748 return (fzap_checksize(integer_size, num_integers));
749 }
750
751 /*
752 * Routines for manipulating attributes.
753 */
754 int
755 fzap_lookup(zap_name_t *zn,
756 uint64_t integer_size, uint64_t num_integers, void *buf,
757 char *realname, int rn_len, boolean_t *ncp)
758 {
759 zap_leaf_t *l;
760 int err;
761 zap_entry_handle_t zeh;
762
763 if ((err = fzap_checkname(zn)) != 0)
764 return (err);
765
766 err = zap_deref_leaf(zn->zn_zap, zn->zn_hash, NULL, RW_READER, &l);
767 if (err != 0)
768 return (err);
769 err = zap_leaf_lookup(l, zn, &zeh);
770 if (err == 0) {
771 if ((err = fzap_checksize(integer_size, num_integers)) != 0) {
772 zap_put_leaf(l);
773 return (err);
774 }
775
776 err = zap_entry_read(&zeh, integer_size, num_integers, buf);
777 (void) zap_entry_read_name(zn->zn_zap, &zeh, rn_len, realname);
778 if (ncp) {
779 *ncp = zap_entry_normalization_conflict(&zeh,
780 zn, NULL, zn->zn_zap);
781 }
782 }
783
784 zap_put_leaf(l);
785 return (err);
786 }
787
788 int
789 fzap_add_cd(zap_name_t *zn,
790 uint64_t integer_size, uint64_t num_integers,
791 const void *val, uint32_t cd, dmu_tx_t *tx)
792 {
793 zap_leaf_t *l;
794 int err;
795 zap_entry_handle_t zeh;
796 zap_t *zap = zn->zn_zap;
797
798 ASSERT(RW_LOCK_HELD(&zap->zap_rwlock));
799 ASSERT(!zap->zap_ismicro);
800 ASSERT(fzap_check(zn, integer_size, num_integers) == 0);
801
802 err = zap_deref_leaf(zap, zn->zn_hash, tx, RW_WRITER, &l);
803 if (err != 0)
804 return (err);
805 retry:
806 err = zap_leaf_lookup(l, zn, &zeh);
807 if (err == 0) {
808 err = EEXIST;
809 goto out;
810 }
811 if (err != ENOENT)
812 goto out;
813
814 err = zap_entry_create(l, zn, cd,
815 integer_size, num_integers, val, &zeh);
816
817 if (err == 0) {
818 zap_increment_num_entries(zap, 1, tx);
819 } else if (err == EAGAIN) {
820 err = zap_expand_leaf(zn, l, tx, &l);
821 zap = zn->zn_zap; /* zap_expand_leaf() may change zap */
822 if (err == 0)
823 goto retry;
824 }
825
826 out:
827 if (zap != NULL)
828 zap_put_leaf_maybe_grow_ptrtbl(zn, l, tx);
829 return (err);
830 }
831
832 int
833 fzap_add(zap_name_t *zn,
834 uint64_t integer_size, uint64_t num_integers,
835 const void *val, dmu_tx_t *tx)
836 {
837 int err = fzap_check(zn, integer_size, num_integers);
838 if (err != 0)
839 return (err);
840
841 return (fzap_add_cd(zn, integer_size, num_integers,
842 val, ZAP_NEED_CD, tx));
843 }
844
845 int
846 fzap_update(zap_name_t *zn,
847 int integer_size, uint64_t num_integers, const void *val, dmu_tx_t *tx)
848 {
849 zap_leaf_t *l;
850 int err, create;
851 zap_entry_handle_t zeh;
852 zap_t *zap = zn->zn_zap;
853
854 ASSERT(RW_LOCK_HELD(&zap->zap_rwlock));
855 err = fzap_check(zn, integer_size, num_integers);
856 if (err != 0)
857 return (err);
858
859 err = zap_deref_leaf(zap, zn->zn_hash, tx, RW_WRITER, &l);
860 if (err != 0)
861 return (err);
862 retry:
863 err = zap_leaf_lookup(l, zn, &zeh);
864 create = (err == ENOENT);
865 ASSERT(err == 0 || err == ENOENT);
866
867 if (create) {
868 err = zap_entry_create(l, zn, ZAP_NEED_CD,
869 integer_size, num_integers, val, &zeh);
870 if (err == 0)
871 zap_increment_num_entries(zap, 1, tx);
872 } else {
873 err = zap_entry_update(&zeh, integer_size, num_integers, val);
874 }
875
876 if (err == EAGAIN) {
877 err = zap_expand_leaf(zn, l, tx, &l);
878 zap = zn->zn_zap; /* zap_expand_leaf() may change zap */
879 if (err == 0)
880 goto retry;
881 }
882
883 if (zap != NULL)
884 zap_put_leaf_maybe_grow_ptrtbl(zn, l, tx);
885 return (err);
886 }
887
888 int
889 fzap_length(zap_name_t *zn,
890 uint64_t *integer_size, uint64_t *num_integers)
891 {
892 zap_leaf_t *l;
893 int err;
894 zap_entry_handle_t zeh;
895
896 err = zap_deref_leaf(zn->zn_zap, zn->zn_hash, NULL, RW_READER, &l);
897 if (err != 0)
898 return (err);
899 err = zap_leaf_lookup(l, zn, &zeh);
900 if (err != 0)
901 goto out;
902
903 if (integer_size)
904 *integer_size = zeh.zeh_integer_size;
905 if (num_integers)
906 *num_integers = zeh.zeh_num_integers;
907 out:
908 zap_put_leaf(l);
909 return (err);
910 }
911
912 int
913 fzap_remove(zap_name_t *zn, dmu_tx_t *tx)
914 {
915 zap_leaf_t *l;
916 int err;
917 zap_entry_handle_t zeh;
918
919 err = zap_deref_leaf(zn->zn_zap, zn->zn_hash, tx, RW_WRITER, &l);
920 if (err != 0)
921 return (err);
922 err = zap_leaf_lookup(l, zn, &zeh);
923 if (err == 0) {
924 zap_entry_remove(&zeh);
925 zap_increment_num_entries(zn->zn_zap, -1, tx);
926 }
927 zap_put_leaf(l);
928 return (err);
929 }
930
931 void
932 fzap_prefetch(zap_name_t *zn)
933 {
934 uint64_t idx, blk;
935 zap_t *zap = zn->zn_zap;
936 int bs;
937
938 idx = ZAP_HASH_IDX(zn->zn_hash,
939 zap->zap_f.zap_phys->zap_ptrtbl.zt_shift);
940 if (zap_idx_to_blk(zap, idx, &blk) != 0)
941 return;
942 bs = FZAP_BLOCK_SHIFT(zap);
943 dmu_prefetch(zap->zap_objset, zap->zap_object, blk << bs, 1 << bs);
944 }
945
946 /*
947 * Helper functions for consumers.
948 */
949
950 uint64_t
951 zap_create_link(objset_t *os, dmu_object_type_t ot, uint64_t parent_obj,
952 const char *name, dmu_tx_t *tx)
953 {
954 uint64_t new_obj;
955
956 VERIFY((new_obj = zap_create(os, ot, DMU_OT_NONE, 0, tx)) > 0);
957 VERIFY(zap_add(os, parent_obj, name, sizeof (uint64_t), 1, &new_obj,
958 tx) == 0);
959
960 return (new_obj);
961 }
962
963 int
964 zap_value_search(objset_t *os, uint64_t zapobj, uint64_t value, uint64_t mask,
965 char *name)
966 {
967 zap_cursor_t zc;
968 zap_attribute_t *za;
969 int err;
970
971 if (mask == 0)
972 mask = -1ULL;
973
974 za = kmem_alloc(sizeof (zap_attribute_t), KM_SLEEP);
975 for (zap_cursor_init(&zc, os, zapobj);
976 (err = zap_cursor_retrieve(&zc, za)) == 0;
977 zap_cursor_advance(&zc)) {
978 if ((za->za_first_integer & mask) == (value & mask)) {
979 (void) strcpy(name, za->za_name);
980 break;
981 }
982 }
983 zap_cursor_fini(&zc);
984 kmem_free(za, sizeof (zap_attribute_t));
985 return (err);
986 }
987
988 int
989 zap_join(objset_t *os, uint64_t fromobj, uint64_t intoobj, dmu_tx_t *tx)
990 {
991 zap_cursor_t zc;
992 zap_attribute_t za;
993 int err;
994
995 for (zap_cursor_init(&zc, os, fromobj);
996 zap_cursor_retrieve(&zc, &za) == 0;
997 (void) zap_cursor_advance(&zc)) {
998 if (za.za_integer_length != 8 || za.za_num_integers != 1)
999 return (EINVAL);
1000 err = zap_add(os, intoobj, za.za_name,
1001 8, 1, &za.za_first_integer, tx);
1002 if (err)
1003 return (err);
1004 }
1005 zap_cursor_fini(&zc);
1006 return (0);
1007 }
1008
1009 int
1010 zap_join_key(objset_t *os, uint64_t fromobj, uint64_t intoobj,
1011 uint64_t value, dmu_tx_t *tx)
1012 {
1013 zap_cursor_t zc;
1014 zap_attribute_t za;
1015 int err;
1016
1017 for (zap_cursor_init(&zc, os, fromobj);
1018 zap_cursor_retrieve(&zc, &za) == 0;
1019 (void) zap_cursor_advance(&zc)) {
1020 if (za.za_integer_length != 8 || za.za_num_integers != 1)
1021 return (EINVAL);
1022 err = zap_add(os, intoobj, za.za_name,
1023 8, 1, &value, tx);
1024 if (err)
1025 return (err);
1026 }
1027 zap_cursor_fini(&zc);
1028 return (0);
1029 }
1030
1031 int
1032 zap_join_increment(objset_t *os, uint64_t fromobj, uint64_t intoobj,
1033 dmu_tx_t *tx)
1034 {
1035 zap_cursor_t zc;
1036 zap_attribute_t za;
1037 int err;
1038
1039 for (zap_cursor_init(&zc, os, fromobj);
1040 zap_cursor_retrieve(&zc, &za) == 0;
1041 (void) zap_cursor_advance(&zc)) {
1042 uint64_t delta = 0;
1043
1044 if (za.za_integer_length != 8 || za.za_num_integers != 1)
1045 return (EINVAL);
1046
1047 err = zap_lookup(os, intoobj, za.za_name, 8, 1, &delta);
1048 if (err != 0 && err != ENOENT)
1049 return (err);
1050 delta += za.za_first_integer;
1051 err = zap_update(os, intoobj, za.za_name, 8, 1, &delta, tx);
1052 if (err)
1053 return (err);
1054 }
1055 zap_cursor_fini(&zc);
1056 return (0);
1057 }
1058
1059 int
1060 zap_add_int(objset_t *os, uint64_t obj, uint64_t value, dmu_tx_t *tx)
1061 {
1062 char name[20];
1063
1064 (void) snprintf(name, sizeof (name), "%llx", (longlong_t)value);
1065 return (zap_add(os, obj, name, 8, 1, &value, tx));
1066 }
1067
1068 int
1069 zap_remove_int(objset_t *os, uint64_t obj, uint64_t value, dmu_tx_t *tx)
1070 {
1071 char name[20];
1072
1073 (void) snprintf(name, sizeof (name), "%llx", (longlong_t)value);
1074 return (zap_remove(os, obj, name, tx));
1075 }
1076
1077 int
1078 zap_lookup_int(objset_t *os, uint64_t obj, uint64_t value)
1079 {
1080 char name[20];
1081
1082 (void) snprintf(name, sizeof (name), "%llx", (longlong_t)value);
1083 return (zap_lookup(os, obj, name, 8, 1, &value));
1084 }
1085
1086 int
1087 zap_add_int_key(objset_t *os, uint64_t obj,
1088 uint64_t key, uint64_t value, dmu_tx_t *tx)
1089 {
1090 char name[20];
1091
1092 (void) snprintf(name, sizeof (name), "%llx", (longlong_t)key);
1093 return (zap_add(os, obj, name, 8, 1, &value, tx));
1094 }
1095
1096 int
1097 zap_lookup_int_key(objset_t *os, uint64_t obj, uint64_t key, uint64_t *valuep)
1098 {
1099 char name[20];
1100
1101 (void) snprintf(name, sizeof (name), "%llx", (longlong_t)key);
1102 return (zap_lookup(os, obj, name, 8, 1, valuep));
1103 }
1104
1105 int
1106 zap_increment(objset_t *os, uint64_t obj, const char *name, int64_t delta,
1107 dmu_tx_t *tx)
1108 {
1109 uint64_t value = 0;
1110 int err;
1111
1112 if (delta == 0)
1113 return (0);
1114
1115 err = zap_lookup(os, obj, name, 8, 1, &value);
1116 if (err != 0 && err != ENOENT)
1117 return (err);
1118 value += delta;
1119 if (value == 0)
1120 err = zap_remove(os, obj, name, tx);
1121 else
1122 err = zap_update(os, obj, name, 8, 1, &value, tx);
1123 return (err);
1124 }
1125
1126 int
1127 zap_increment_int(objset_t *os, uint64_t obj, uint64_t key, int64_t delta,
1128 dmu_tx_t *tx)
1129 {
1130 char name[20];
1131
1132 (void) snprintf(name, sizeof (name), "%llx", (longlong_t)key);
1133 return (zap_increment(os, obj, name, delta, tx));
1134 }
1135
1136 /*
1137 * Routines for iterating over the attributes.
1138 */
1139
1140 int
1141 fzap_cursor_retrieve(zap_t *zap, zap_cursor_t *zc, zap_attribute_t *za)
1142 {
1143 int err = ENOENT;
1144 zap_entry_handle_t zeh;
1145 zap_leaf_t *l;
1146
1147 /* retrieve the next entry at or after zc_hash/zc_cd */
1148 /* if no entry, return ENOENT */
1149
1150 if (zc->zc_leaf &&
1151 (ZAP_HASH_IDX(zc->zc_hash,
1152 zc->zc_leaf->l_phys->l_hdr.lh_prefix_len) !=
1153 zc->zc_leaf->l_phys->l_hdr.lh_prefix)) {
1154 rw_enter(&zc->zc_leaf->l_rwlock, RW_READER);
1155 zap_put_leaf(zc->zc_leaf);
1156 zc->zc_leaf = NULL;
1157 }
1158
1159 again:
1160 if (zc->zc_leaf == NULL) {
1161 err = zap_deref_leaf(zap, zc->zc_hash, NULL, RW_READER,
1162 &zc->zc_leaf);
1163 if (err != 0)
1164 return (err);
1165 } else {
1166 rw_enter(&zc->zc_leaf->l_rwlock, RW_READER);
1167 }
1168 l = zc->zc_leaf;
1169
1170 err = zap_leaf_lookup_closest(l, zc->zc_hash, zc->zc_cd, &zeh);
1171
1172 if (err == ENOENT) {
1173 uint64_t nocare =
1174 (1ULL << (64 - l->l_phys->l_hdr.lh_prefix_len)) - 1;
1175 zc->zc_hash = (zc->zc_hash & ~nocare) + nocare + 1;
1176 zc->zc_cd = 0;
1177 if (l->l_phys->l_hdr.lh_prefix_len == 0 || zc->zc_hash == 0) {
1178 zc->zc_hash = -1ULL;
1179 } else {
1180 zap_put_leaf(zc->zc_leaf);
1181 zc->zc_leaf = NULL;
1182 goto again;
1183 }
1184 }
1185
1186 if (err == 0) {
1187 zc->zc_hash = zeh.zeh_hash;
1188 zc->zc_cd = zeh.zeh_cd;
1189 za->za_integer_length = zeh.zeh_integer_size;
1190 za->za_num_integers = zeh.zeh_num_integers;
1191 if (zeh.zeh_num_integers == 0) {
1192 za->za_first_integer = 0;
1193 } else {
1194 err = zap_entry_read(&zeh, 8, 1, &za->za_first_integer);
1195 ASSERT(err == 0 || err == EOVERFLOW);
1196 }
1197 err = zap_entry_read_name(zap, &zeh,
1198 sizeof (za->za_name), za->za_name);
1199 ASSERT(err == 0);
1200
1201 za->za_normalization_conflict =
1202 zap_entry_normalization_conflict(&zeh,
1203 NULL, za->za_name, zap);
1204 }
1205 rw_exit(&zc->zc_leaf->l_rwlock);
1206 return (err);
1207 }
1208
1209 static void
1210 zap_stats_ptrtbl(zap_t *zap, uint64_t *tbl, int len, zap_stats_t *zs)
1211 {
1212 int i, err;
1213 uint64_t lastblk = 0;
1214
1215 /*
1216 * NB: if a leaf has more pointers than an entire ptrtbl block
1217 * can hold, then it'll be accounted for more than once, since
1218 * we won't have lastblk.
1219 */
1220 for (i = 0; i < len; i++) {
1221 zap_leaf_t *l;
1222
1223 if (tbl[i] == lastblk)
1224 continue;
1225 lastblk = tbl[i];
1226
1227 err = zap_get_leaf_byblk(zap, tbl[i], NULL, RW_READER, &l);
1228 if (err == 0) {
1229 zap_leaf_stats(zap, l, zs);
1230 zap_put_leaf(l);
1231 }
1232 }
1233 }
1234
1235 int
1236 fzap_cursor_move_to_key(zap_cursor_t *zc, zap_name_t *zn)
1237 {
1238 int err;
1239 zap_leaf_t *l;
1240 zap_entry_handle_t zeh;
1241
1242 if (zn->zn_key_orig_numints * zn->zn_key_intlen > ZAP_MAXNAMELEN)
1243 return (ENAMETOOLONG);
1244
1245 err = zap_deref_leaf(zc->zc_zap, zn->zn_hash, NULL, RW_READER, &l);
1246 if (err != 0)
1247 return (err);
1248
1249 err = zap_leaf_lookup(l, zn, &zeh);
1250 if (err != 0)
1251 return (err);
1252
1253 zc->zc_leaf = l;
1254 zc->zc_hash = zeh.zeh_hash;
1255 zc->zc_cd = zeh.zeh_cd;
1256
1257 return (err);
1258 }
1259
1260 void
1261 fzap_get_stats(zap_t *zap, zap_stats_t *zs)
1262 {
1263 int bs = FZAP_BLOCK_SHIFT(zap);
1264 zs->zs_blocksize = 1ULL << bs;
1265
1266 /*
1267 * Set zap_phys_t fields
1268 */
1269 zs->zs_num_leafs = zap->zap_f.zap_phys->zap_num_leafs;
1270 zs->zs_num_entries = zap->zap_f.zap_phys->zap_num_entries;
1271 zs->zs_num_blocks = zap->zap_f.zap_phys->zap_freeblk;
1272 zs->zs_block_type = zap->zap_f.zap_phys->zap_block_type;
1273 zs->zs_magic = zap->zap_f.zap_phys->zap_magic;
1274 zs->zs_salt = zap->zap_f.zap_phys->zap_salt;
1275
1276 /*
1277 * Set zap_ptrtbl fields
1278 */
1279 zs->zs_ptrtbl_len = 1ULL << zap->zap_f.zap_phys->zap_ptrtbl.zt_shift;
1280 zs->zs_ptrtbl_nextblk = zap->zap_f.zap_phys->zap_ptrtbl.zt_nextblk;
1281 zs->zs_ptrtbl_blks_copied =
1282 zap->zap_f.zap_phys->zap_ptrtbl.zt_blks_copied;
1283 zs->zs_ptrtbl_zt_blk = zap->zap_f.zap_phys->zap_ptrtbl.zt_blk;
1284 zs->zs_ptrtbl_zt_numblks = zap->zap_f.zap_phys->zap_ptrtbl.zt_numblks;
1285 zs->zs_ptrtbl_zt_shift = zap->zap_f.zap_phys->zap_ptrtbl.zt_shift;
1286
1287 if (zap->zap_f.zap_phys->zap_ptrtbl.zt_numblks == 0) {
1288 /* the ptrtbl is entirely in the header block. */
1289 zap_stats_ptrtbl(zap, &ZAP_EMBEDDED_PTRTBL_ENT(zap, 0),
1290 1 << ZAP_EMBEDDED_PTRTBL_SHIFT(zap), zs);
1291 } else {
1292 int b;
1293
1294 dmu_prefetch(zap->zap_objset, zap->zap_object,
1295 zap->zap_f.zap_phys->zap_ptrtbl.zt_blk << bs,
1296 zap->zap_f.zap_phys->zap_ptrtbl.zt_numblks << bs);
1297
1298 for (b = 0; b < zap->zap_f.zap_phys->zap_ptrtbl.zt_numblks;
1299 b++) {
1300 dmu_buf_t *db;
1301 int err;
1302
1303 err = dmu_buf_hold(zap->zap_objset, zap->zap_object,
1304 (zap->zap_f.zap_phys->zap_ptrtbl.zt_blk + b) << bs,
1305 FTAG, &db, DMU_READ_NO_PREFETCH);
1306 if (err == 0) {
1307 zap_stats_ptrtbl(zap, db->db_data,
1308 1<<(bs-3), zs);
1309 dmu_buf_rele(db, FTAG);
1310 }
1311 }
1312 }
1313 }
1314
1315 int
1316 fzap_count_write(zap_name_t *zn, int add, uint64_t *towrite,
1317 uint64_t *tooverwrite)
1318 {
1319 zap_t *zap = zn->zn_zap;
1320 zap_leaf_t *l;
1321 int err;
1322
1323 /*
1324 * Account for the header block of the fatzap.
1325 */
1326 if (!add && dmu_buf_freeable(zap->zap_dbuf)) {
1327 *tooverwrite += zap->zap_dbuf->db_size;
1328 } else {
1329 *towrite += zap->zap_dbuf->db_size;
1330 }
1331
1332 /*
1333 * Account for the pointer table blocks.
1334 * If we are adding we need to account for the following cases :
1335 * - If the pointer table is embedded, this operation could force an
1336 * external pointer table.
1337 * - If this already has an external pointer table this operation
1338 * could extend the table.
1339 */
1340 if (add) {
1341 if (zap->zap_f.zap_phys->zap_ptrtbl.zt_blk == 0)
1342 *towrite += zap->zap_dbuf->db_size;
1343 else
1344 *towrite += (zap->zap_dbuf->db_size * 3);
1345 }
1346
1347 /*
1348 * Now, check if the block containing leaf is freeable
1349 * and account accordingly.
1350 */
1351 err = zap_deref_leaf(zap, zn->zn_hash, NULL, RW_READER, &l);
1352 if (err != 0) {
1353 return (err);
1354 }
1355
1356 if (!add && dmu_buf_freeable(l->l_dbuf)) {
1357 *tooverwrite += l->l_dbuf->db_size;
1358 } else {
1359 /*
1360 * If this an add operation, the leaf block could split.
1361 * Hence, we need to account for an additional leaf block.
1362 */
1363 *towrite += (add ? 2 : 1) * l->l_dbuf->db_size;
1364 }
1365
1366 zap_put_leaf(l);
1367 return (0);
1368 }