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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 https://opensource.org/licenses/CDDL-1.0.
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, 2020 by Delphix. All rights reserved.
24 * Copyright (c) 2013 by Saso Kiselkov. All rights reserved.
25 * Copyright (c) 2013, Joyent, Inc. All rights reserved.
26 * Copyright (c) 2016, Nexenta Systems, Inc. All rights reserved.
27 * Copyright (c) 2015 by Chunwei Chen. All rights reserved.
28 * Copyright (c) 2019 Datto Inc.
29 * Copyright (c) 2019, Klara Inc.
30 * Copyright (c) 2019, Allan Jude
31 * Copyright (c) 2022 Hewlett Packard Enterprise Development LP.
32 * Copyright (c) 2021, 2022 by Pawel Jakub Dawidek
33 */
34
35 #include <sys/dmu.h>
36 #include <sys/dmu_impl.h>
37 #include <sys/dmu_tx.h>
38 #include <sys/dbuf.h>
39 #include <sys/dnode.h>
40 #include <sys/zfs_context.h>
41 #include <sys/dmu_objset.h>
42 #include <sys/dmu_traverse.h>
43 #include <sys/dsl_dataset.h>
44 #include <sys/dsl_dir.h>
45 #include <sys/dsl_pool.h>
46 #include <sys/dsl_synctask.h>
47 #include <sys/dsl_prop.h>
48 #include <sys/dmu_zfetch.h>
49 #include <sys/zfs_ioctl.h>
50 #include <sys/zap.h>
51 #include <sys/zio_checksum.h>
52 #include <sys/zio_compress.h>
53 #include <sys/sa.h>
54 #include <sys/zfeature.h>
55 #include <sys/abd.h>
56 #include <sys/brt.h>
57 #include <sys/trace_zfs.h>
58 #include <sys/zfs_racct.h>
59 #include <sys/zfs_rlock.h>
60 #ifdef _KERNEL
61 #include <sys/vmsystm.h>
62 #include <sys/zfs_znode.h>
63 #endif
64
65 /*
66 * Enable/disable nopwrite feature.
67 */
68 static int zfs_nopwrite_enabled = 1;
69
70 /*
71 * Tunable to control percentage of dirtied L1 blocks from frees allowed into
72 * one TXG. After this threshold is crossed, additional dirty blocks from frees
73 * will wait until the next TXG.
74 * A value of zero will disable this throttle.
75 */
76 static uint_t zfs_per_txg_dirty_frees_percent = 30;
77
78 /*
79 * Enable/disable forcing txg sync when dirty checking for holes with lseek().
80 * By default this is enabled to ensure accurate hole reporting, it can result
81 * in a significant performance penalty for lseek(SEEK_HOLE) heavy workloads.
82 * Disabling this option will result in holes never being reported in dirty
83 * files which is always safe.
84 */
85 static int zfs_dmu_offset_next_sync = 1;
86
87 /*
88 * Limit the amount we can prefetch with one call to this amount. This
89 * helps to limit the amount of memory that can be used by prefetching.
90 * Larger objects should be prefetched a bit at a time.
91 */
92 #ifdef _ILP32
93 uint_t dmu_prefetch_max = 8 * 1024 * 1024;
94 #else
95 uint_t dmu_prefetch_max = 8 * SPA_MAXBLOCKSIZE;
96 #endif
97
98 const dmu_object_type_info_t dmu_ot[DMU_OT_NUMTYPES] = {
99 {DMU_BSWAP_UINT8, TRUE, FALSE, FALSE, "unallocated" },
100 {DMU_BSWAP_ZAP, TRUE, TRUE, FALSE, "object directory" },
101 {DMU_BSWAP_UINT64, TRUE, TRUE, FALSE, "object array" },
102 {DMU_BSWAP_UINT8, TRUE, FALSE, FALSE, "packed nvlist" },
103 {DMU_BSWAP_UINT64, TRUE, FALSE, FALSE, "packed nvlist size" },
104 {DMU_BSWAP_UINT64, TRUE, FALSE, FALSE, "bpobj" },
105 {DMU_BSWAP_UINT64, TRUE, FALSE, FALSE, "bpobj header" },
106 {DMU_BSWAP_UINT64, TRUE, FALSE, FALSE, "SPA space map header" },
107 {DMU_BSWAP_UINT64, TRUE, FALSE, FALSE, "SPA space map" },
108 {DMU_BSWAP_UINT64, TRUE, FALSE, TRUE, "ZIL intent log" },
109 {DMU_BSWAP_DNODE, TRUE, FALSE, TRUE, "DMU dnode" },
110 {DMU_BSWAP_OBJSET, TRUE, TRUE, FALSE, "DMU objset" },
111 {DMU_BSWAP_UINT64, TRUE, TRUE, FALSE, "DSL directory" },
112 {DMU_BSWAP_ZAP, TRUE, TRUE, FALSE, "DSL directory child map"},
113 {DMU_BSWAP_ZAP, TRUE, TRUE, FALSE, "DSL dataset snap map" },
114 {DMU_BSWAP_ZAP, TRUE, TRUE, FALSE, "DSL props" },
115 {DMU_BSWAP_UINT64, TRUE, TRUE, FALSE, "DSL dataset" },
116 {DMU_BSWAP_ZNODE, TRUE, FALSE, FALSE, "ZFS znode" },
117 {DMU_BSWAP_OLDACL, TRUE, FALSE, TRUE, "ZFS V0 ACL" },
118 {DMU_BSWAP_UINT8, FALSE, FALSE, TRUE, "ZFS plain file" },
119 {DMU_BSWAP_ZAP, TRUE, FALSE, TRUE, "ZFS directory" },
120 {DMU_BSWAP_ZAP, TRUE, FALSE, FALSE, "ZFS master node" },
121 {DMU_BSWAP_ZAP, TRUE, FALSE, TRUE, "ZFS delete queue" },
122 {DMU_BSWAP_UINT8, FALSE, FALSE, TRUE, "zvol object" },
123 {DMU_BSWAP_ZAP, TRUE, FALSE, FALSE, "zvol prop" },
124 {DMU_BSWAP_UINT8, FALSE, FALSE, TRUE, "other uint8[]" },
125 {DMU_BSWAP_UINT64, FALSE, FALSE, TRUE, "other uint64[]" },
126 {DMU_BSWAP_ZAP, TRUE, FALSE, FALSE, "other ZAP" },
127 {DMU_BSWAP_ZAP, TRUE, FALSE, FALSE, "persistent error log" },
128 {DMU_BSWAP_UINT8, TRUE, FALSE, FALSE, "SPA history" },
129 {DMU_BSWAP_UINT64, TRUE, FALSE, FALSE, "SPA history offsets" },
130 {DMU_BSWAP_ZAP, TRUE, TRUE, FALSE, "Pool properties" },
131 {DMU_BSWAP_ZAP, TRUE, TRUE, FALSE, "DSL permissions" },
132 {DMU_BSWAP_ACL, TRUE, FALSE, TRUE, "ZFS ACL" },
133 {DMU_BSWAP_UINT8, TRUE, FALSE, TRUE, "ZFS SYSACL" },
134 {DMU_BSWAP_UINT8, TRUE, FALSE, TRUE, "FUID table" },
135 {DMU_BSWAP_UINT64, TRUE, FALSE, FALSE, "FUID table size" },
136 {DMU_BSWAP_ZAP, TRUE, TRUE, FALSE, "DSL dataset next clones"},
137 {DMU_BSWAP_ZAP, TRUE, FALSE, FALSE, "scan work queue" },
138 {DMU_BSWAP_ZAP, TRUE, FALSE, TRUE, "ZFS user/group/project used" },
139 {DMU_BSWAP_ZAP, TRUE, FALSE, TRUE, "ZFS user/group/project quota"},
140 {DMU_BSWAP_ZAP, TRUE, TRUE, FALSE, "snapshot refcount tags"},
141 {DMU_BSWAP_ZAP, TRUE, FALSE, FALSE, "DDT ZAP algorithm" },
142 {DMU_BSWAP_ZAP, TRUE, FALSE, FALSE, "DDT statistics" },
143 {DMU_BSWAP_UINT8, TRUE, FALSE, TRUE, "System attributes" },
144 {DMU_BSWAP_ZAP, TRUE, FALSE, TRUE, "SA master node" },
145 {DMU_BSWAP_ZAP, TRUE, FALSE, TRUE, "SA attr registration" },
146 {DMU_BSWAP_ZAP, TRUE, FALSE, TRUE, "SA attr layouts" },
147 {DMU_BSWAP_ZAP, TRUE, FALSE, FALSE, "scan translations" },
148 {DMU_BSWAP_UINT8, FALSE, FALSE, TRUE, "deduplicated block" },
149 {DMU_BSWAP_ZAP, TRUE, TRUE, FALSE, "DSL deadlist map" },
150 {DMU_BSWAP_UINT64, TRUE, TRUE, FALSE, "DSL deadlist map hdr" },
151 {DMU_BSWAP_ZAP, TRUE, TRUE, FALSE, "DSL dir clones" },
152 {DMU_BSWAP_UINT64, TRUE, FALSE, FALSE, "bpobj subobj" }
153 };
154
155 dmu_object_byteswap_info_t dmu_ot_byteswap[DMU_BSWAP_NUMFUNCS] = {
156 { byteswap_uint8_array, "uint8" },
157 { byteswap_uint16_array, "uint16" },
158 { byteswap_uint32_array, "uint32" },
159 { byteswap_uint64_array, "uint64" },
160 { zap_byteswap, "zap" },
161 { dnode_buf_byteswap, "dnode" },
162 { dmu_objset_byteswap, "objset" },
163 { zfs_znode_byteswap, "znode" },
164 { zfs_oldacl_byteswap, "oldacl" },
165 { zfs_acl_byteswap, "acl" }
166 };
167
168 int
169 dmu_buf_hold_noread_by_dnode(dnode_t *dn, uint64_t offset,
170 const void *tag, dmu_buf_t **dbp)
171 {
172 uint64_t blkid;
173 dmu_buf_impl_t *db;
174
175 rw_enter(&dn->dn_struct_rwlock, RW_READER);
176 blkid = dbuf_whichblock(dn, 0, offset);
177 db = dbuf_hold(dn, blkid, tag);
178 rw_exit(&dn->dn_struct_rwlock);
179
180 if (db == NULL) {
181 *dbp = NULL;
182 return (SET_ERROR(EIO));
183 }
184
185 *dbp = &db->db;
186 return (0);
187 }
188
189 int
190 dmu_buf_hold_noread(objset_t *os, uint64_t object, uint64_t offset,
191 const void *tag, dmu_buf_t **dbp)
192 {
193 dnode_t *dn;
194 uint64_t blkid;
195 dmu_buf_impl_t *db;
196 int err;
197
198 err = dnode_hold(os, object, FTAG, &dn);
199 if (err)
200 return (err);
201 rw_enter(&dn->dn_struct_rwlock, RW_READER);
202 blkid = dbuf_whichblock(dn, 0, offset);
203 db = dbuf_hold(dn, blkid, tag);
204 rw_exit(&dn->dn_struct_rwlock);
205 dnode_rele(dn, FTAG);
206
207 if (db == NULL) {
208 *dbp = NULL;
209 return (SET_ERROR(EIO));
210 }
211
212 *dbp = &db->db;
213 return (err);
214 }
215
216 int
217 dmu_buf_hold_by_dnode(dnode_t *dn, uint64_t offset,
218 const void *tag, dmu_buf_t **dbp, int flags)
219 {
220 int err;
221 int db_flags = DB_RF_CANFAIL;
222
223 if (flags & DMU_READ_NO_PREFETCH)
224 db_flags |= DB_RF_NOPREFETCH;
225 if (flags & DMU_READ_NO_DECRYPT)
226 db_flags |= DB_RF_NO_DECRYPT;
227
228 err = dmu_buf_hold_noread_by_dnode(dn, offset, tag, dbp);
229 if (err == 0) {
230 dmu_buf_impl_t *db = (dmu_buf_impl_t *)(*dbp);
231 err = dbuf_read(db, NULL, db_flags);
232 if (err != 0) {
233 dbuf_rele(db, tag);
234 *dbp = NULL;
235 }
236 }
237
238 return (err);
239 }
240
241 int
242 dmu_buf_hold(objset_t *os, uint64_t object, uint64_t offset,
243 const void *tag, dmu_buf_t **dbp, int flags)
244 {
245 int err;
246 int db_flags = DB_RF_CANFAIL;
247
248 if (flags & DMU_READ_NO_PREFETCH)
249 db_flags |= DB_RF_NOPREFETCH;
250 if (flags & DMU_READ_NO_DECRYPT)
251 db_flags |= DB_RF_NO_DECRYPT;
252
253 err = dmu_buf_hold_noread(os, object, offset, tag, dbp);
254 if (err == 0) {
255 dmu_buf_impl_t *db = (dmu_buf_impl_t *)(*dbp);
256 err = dbuf_read(db, NULL, db_flags);
257 if (err != 0) {
258 dbuf_rele(db, tag);
259 *dbp = NULL;
260 }
261 }
262
263 return (err);
264 }
265
266 int
267 dmu_bonus_max(void)
268 {
269 return (DN_OLD_MAX_BONUSLEN);
270 }
271
272 int
273 dmu_set_bonus(dmu_buf_t *db_fake, int newsize, dmu_tx_t *tx)
274 {
275 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
276 dnode_t *dn;
277 int error;
278
279 DB_DNODE_ENTER(db);
280 dn = DB_DNODE(db);
281
282 if (dn->dn_bonus != db) {
283 error = SET_ERROR(EINVAL);
284 } else if (newsize < 0 || newsize > db_fake->db_size) {
285 error = SET_ERROR(EINVAL);
286 } else {
287 dnode_setbonuslen(dn, newsize, tx);
288 error = 0;
289 }
290
291 DB_DNODE_EXIT(db);
292 return (error);
293 }
294
295 int
296 dmu_set_bonustype(dmu_buf_t *db_fake, dmu_object_type_t type, dmu_tx_t *tx)
297 {
298 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
299 dnode_t *dn;
300 int error;
301
302 DB_DNODE_ENTER(db);
303 dn = DB_DNODE(db);
304
305 if (!DMU_OT_IS_VALID(type)) {
306 error = SET_ERROR(EINVAL);
307 } else if (dn->dn_bonus != db) {
308 error = SET_ERROR(EINVAL);
309 } else {
310 dnode_setbonus_type(dn, type, tx);
311 error = 0;
312 }
313
314 DB_DNODE_EXIT(db);
315 return (error);
316 }
317
318 dmu_object_type_t
319 dmu_get_bonustype(dmu_buf_t *db_fake)
320 {
321 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
322 dnode_t *dn;
323 dmu_object_type_t type;
324
325 DB_DNODE_ENTER(db);
326 dn = DB_DNODE(db);
327 type = dn->dn_bonustype;
328 DB_DNODE_EXIT(db);
329
330 return (type);
331 }
332
333 int
334 dmu_rm_spill(objset_t *os, uint64_t object, dmu_tx_t *tx)
335 {
336 dnode_t *dn;
337 int error;
338
339 error = dnode_hold(os, object, FTAG, &dn);
340 dbuf_rm_spill(dn, tx);
341 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
342 dnode_rm_spill(dn, tx);
343 rw_exit(&dn->dn_struct_rwlock);
344 dnode_rele(dn, FTAG);
345 return (error);
346 }
347
348 /*
349 * Lookup and hold the bonus buffer for the provided dnode. If the dnode
350 * has not yet been allocated a new bonus dbuf a will be allocated.
351 * Returns ENOENT, EIO, or 0.
352 */
353 int dmu_bonus_hold_by_dnode(dnode_t *dn, const void *tag, dmu_buf_t **dbp,
354 uint32_t flags)
355 {
356 dmu_buf_impl_t *db;
357 int error;
358 uint32_t db_flags = DB_RF_MUST_SUCCEED;
359
360 if (flags & DMU_READ_NO_PREFETCH)
361 db_flags |= DB_RF_NOPREFETCH;
362 if (flags & DMU_READ_NO_DECRYPT)
363 db_flags |= DB_RF_NO_DECRYPT;
364
365 rw_enter(&dn->dn_struct_rwlock, RW_READER);
366 if (dn->dn_bonus == NULL) {
367 if (!rw_tryupgrade(&dn->dn_struct_rwlock)) {
368 rw_exit(&dn->dn_struct_rwlock);
369 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
370 }
371 if (dn->dn_bonus == NULL)
372 dbuf_create_bonus(dn);
373 }
374 db = dn->dn_bonus;
375
376 /* as long as the bonus buf is held, the dnode will be held */
377 if (zfs_refcount_add(&db->db_holds, tag) == 1) {
378 VERIFY(dnode_add_ref(dn, db));
379 atomic_inc_32(&dn->dn_dbufs_count);
380 }
381
382 /*
383 * Wait to drop dn_struct_rwlock until after adding the bonus dbuf's
384 * hold and incrementing the dbuf count to ensure that dnode_move() sees
385 * a dnode hold for every dbuf.
386 */
387 rw_exit(&dn->dn_struct_rwlock);
388
389 error = dbuf_read(db, NULL, db_flags);
390 if (error) {
391 dnode_evict_bonus(dn);
392 dbuf_rele(db, tag);
393 *dbp = NULL;
394 return (error);
395 }
396
397 *dbp = &db->db;
398 return (0);
399 }
400
401 int
402 dmu_bonus_hold(objset_t *os, uint64_t object, const void *tag, dmu_buf_t **dbp)
403 {
404 dnode_t *dn;
405 int error;
406
407 error = dnode_hold(os, object, FTAG, &dn);
408 if (error)
409 return (error);
410
411 error = dmu_bonus_hold_by_dnode(dn, tag, dbp, DMU_READ_NO_PREFETCH);
412 dnode_rele(dn, FTAG);
413
414 return (error);
415 }
416
417 /*
418 * returns ENOENT, EIO, or 0.
419 *
420 * This interface will allocate a blank spill dbuf when a spill blk
421 * doesn't already exist on the dnode.
422 *
423 * if you only want to find an already existing spill db, then
424 * dmu_spill_hold_existing() should be used.
425 */
426 int
427 dmu_spill_hold_by_dnode(dnode_t *dn, uint32_t flags, const void *tag,
428 dmu_buf_t **dbp)
429 {
430 dmu_buf_impl_t *db = NULL;
431 int err;
432
433 if ((flags & DB_RF_HAVESTRUCT) == 0)
434 rw_enter(&dn->dn_struct_rwlock, RW_READER);
435
436 db = dbuf_hold(dn, DMU_SPILL_BLKID, tag);
437
438 if ((flags & DB_RF_HAVESTRUCT) == 0)
439 rw_exit(&dn->dn_struct_rwlock);
440
441 if (db == NULL) {
442 *dbp = NULL;
443 return (SET_ERROR(EIO));
444 }
445 err = dbuf_read(db, NULL, flags);
446 if (err == 0)
447 *dbp = &db->db;
448 else {
449 dbuf_rele(db, tag);
450 *dbp = NULL;
451 }
452 return (err);
453 }
454
455 int
456 dmu_spill_hold_existing(dmu_buf_t *bonus, const void *tag, dmu_buf_t **dbp)
457 {
458 dmu_buf_impl_t *db = (dmu_buf_impl_t *)bonus;
459 dnode_t *dn;
460 int err;
461
462 DB_DNODE_ENTER(db);
463 dn = DB_DNODE(db);
464
465 if (spa_version(dn->dn_objset->os_spa) < SPA_VERSION_SA) {
466 err = SET_ERROR(EINVAL);
467 } else {
468 rw_enter(&dn->dn_struct_rwlock, RW_READER);
469
470 if (!dn->dn_have_spill) {
471 err = SET_ERROR(ENOENT);
472 } else {
473 err = dmu_spill_hold_by_dnode(dn,
474 DB_RF_HAVESTRUCT | DB_RF_CANFAIL, tag, dbp);
475 }
476
477 rw_exit(&dn->dn_struct_rwlock);
478 }
479
480 DB_DNODE_EXIT(db);
481 return (err);
482 }
483
484 int
485 dmu_spill_hold_by_bonus(dmu_buf_t *bonus, uint32_t flags, const void *tag,
486 dmu_buf_t **dbp)
487 {
488 dmu_buf_impl_t *db = (dmu_buf_impl_t *)bonus;
489 dnode_t *dn;
490 int err;
491 uint32_t db_flags = DB_RF_CANFAIL;
492
493 if (flags & DMU_READ_NO_DECRYPT)
494 db_flags |= DB_RF_NO_DECRYPT;
495
496 DB_DNODE_ENTER(db);
497 dn = DB_DNODE(db);
498 err = dmu_spill_hold_by_dnode(dn, db_flags, tag, dbp);
499 DB_DNODE_EXIT(db);
500
501 return (err);
502 }
503
504 /*
505 * Note: longer-term, we should modify all of the dmu_buf_*() interfaces
506 * to take a held dnode rather than <os, object> -- the lookup is wasteful,
507 * and can induce severe lock contention when writing to several files
508 * whose dnodes are in the same block.
509 */
510 int
511 dmu_buf_hold_array_by_dnode(dnode_t *dn, uint64_t offset, uint64_t length,
512 boolean_t read, const void *tag, int *numbufsp, dmu_buf_t ***dbpp,
513 uint32_t flags)
514 {
515 dmu_buf_t **dbp;
516 zstream_t *zs = NULL;
517 uint64_t blkid, nblks, i;
518 uint32_t dbuf_flags;
519 int err;
520 zio_t *zio = NULL;
521 boolean_t missed = B_FALSE;
522
523 ASSERT(!read || length <= DMU_MAX_ACCESS);
524
525 /*
526 * Note: We directly notify the prefetch code of this read, so that
527 * we can tell it about the multi-block read. dbuf_read() only knows
528 * about the one block it is accessing.
529 */
530 dbuf_flags = DB_RF_CANFAIL | DB_RF_NEVERWAIT | DB_RF_HAVESTRUCT |
531 DB_RF_NOPREFETCH;
532
533 if ((flags & DMU_READ_NO_DECRYPT) != 0)
534 dbuf_flags |= DB_RF_NO_DECRYPT;
535
536 rw_enter(&dn->dn_struct_rwlock, RW_READER);
537 if (dn->dn_datablkshift) {
538 int blkshift = dn->dn_datablkshift;
539 nblks = (P2ROUNDUP(offset + length, 1ULL << blkshift) -
540 P2ALIGN(offset, 1ULL << blkshift)) >> blkshift;
541 } else {
542 if (offset + length > dn->dn_datablksz) {
543 zfs_panic_recover("zfs: accessing past end of object "
544 "%llx/%llx (size=%u access=%llu+%llu)",
545 (longlong_t)dn->dn_objset->
546 os_dsl_dataset->ds_object,
547 (longlong_t)dn->dn_object, dn->dn_datablksz,
548 (longlong_t)offset, (longlong_t)length);
549 rw_exit(&dn->dn_struct_rwlock);
550 return (SET_ERROR(EIO));
551 }
552 nblks = 1;
553 }
554 dbp = kmem_zalloc(sizeof (dmu_buf_t *) * nblks, KM_SLEEP);
555
556 if (read)
557 zio = zio_root(dn->dn_objset->os_spa, NULL, NULL,
558 ZIO_FLAG_CANFAIL);
559 blkid = dbuf_whichblock(dn, 0, offset);
560 if ((flags & DMU_READ_NO_PREFETCH) == 0) {
561 /*
562 * Prepare the zfetch before initiating the demand reads, so
563 * that if multiple threads block on same indirect block, we
564 * base predictions on the original less racy request order.
565 */
566 zs = dmu_zfetch_prepare(&dn->dn_zfetch, blkid, nblks, read,
567 B_TRUE);
568 }
569 for (i = 0; i < nblks; i++) {
570 dmu_buf_impl_t *db = dbuf_hold(dn, blkid + i, tag);
571 if (db == NULL) {
572 if (zs)
573 dmu_zfetch_run(zs, missed, B_TRUE);
574 rw_exit(&dn->dn_struct_rwlock);
575 dmu_buf_rele_array(dbp, nblks, tag);
576 if (read)
577 zio_nowait(zio);
578 return (SET_ERROR(EIO));
579 }
580
581 /*
582 * Initiate async demand data read.
583 * We check the db_state after calling dbuf_read() because
584 * (1) dbuf_read() may change the state to CACHED due to a
585 * hit in the ARC, and (2) on a cache miss, a child will
586 * have been added to "zio" but not yet completed, so the
587 * state will not yet be CACHED.
588 */
589 if (read) {
590 if (i == nblks - 1 && blkid + i < dn->dn_maxblkid &&
591 offset + length < db->db.db_offset +
592 db->db.db_size) {
593 if (offset <= db->db.db_offset)
594 dbuf_flags |= DB_RF_PARTIAL_FIRST;
595 else
596 dbuf_flags |= DB_RF_PARTIAL_MORE;
597 }
598 (void) dbuf_read(db, zio, dbuf_flags);
599 if (db->db_state != DB_CACHED)
600 missed = B_TRUE;
601 }
602 dbp[i] = &db->db;
603 }
604
605 if (!read)
606 zfs_racct_write(length, nblks);
607
608 if (zs)
609 dmu_zfetch_run(zs, missed, B_TRUE);
610 rw_exit(&dn->dn_struct_rwlock);
611
612 if (read) {
613 /* wait for async read i/o */
614 err = zio_wait(zio);
615 if (err) {
616 dmu_buf_rele_array(dbp, nblks, tag);
617 return (err);
618 }
619
620 /* wait for other io to complete */
621 for (i = 0; i < nblks; i++) {
622 dmu_buf_impl_t *db = (dmu_buf_impl_t *)dbp[i];
623 mutex_enter(&db->db_mtx);
624 while (db->db_state == DB_READ ||
625 db->db_state == DB_FILL)
626 cv_wait(&db->db_changed, &db->db_mtx);
627 if (db->db_state == DB_UNCACHED)
628 err = SET_ERROR(EIO);
629 mutex_exit(&db->db_mtx);
630 if (err) {
631 dmu_buf_rele_array(dbp, nblks, tag);
632 return (err);
633 }
634 }
635 }
636
637 *numbufsp = nblks;
638 *dbpp = dbp;
639 return (0);
640 }
641
642 int
643 dmu_buf_hold_array(objset_t *os, uint64_t object, uint64_t offset,
644 uint64_t length, int read, const void *tag, int *numbufsp,
645 dmu_buf_t ***dbpp)
646 {
647 dnode_t *dn;
648 int err;
649
650 err = dnode_hold(os, object, FTAG, &dn);
651 if (err)
652 return (err);
653
654 err = dmu_buf_hold_array_by_dnode(dn, offset, length, read, tag,
655 numbufsp, dbpp, DMU_READ_PREFETCH);
656
657 dnode_rele(dn, FTAG);
658
659 return (err);
660 }
661
662 int
663 dmu_buf_hold_array_by_bonus(dmu_buf_t *db_fake, uint64_t offset,
664 uint64_t length, boolean_t read, const void *tag, int *numbufsp,
665 dmu_buf_t ***dbpp)
666 {
667 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
668 dnode_t *dn;
669 int err;
670
671 DB_DNODE_ENTER(db);
672 dn = DB_DNODE(db);
673 err = dmu_buf_hold_array_by_dnode(dn, offset, length, read, tag,
674 numbufsp, dbpp, DMU_READ_PREFETCH);
675 DB_DNODE_EXIT(db);
676
677 return (err);
678 }
679
680 void
681 dmu_buf_rele_array(dmu_buf_t **dbp_fake, int numbufs, const void *tag)
682 {
683 int i;
684 dmu_buf_impl_t **dbp = (dmu_buf_impl_t **)dbp_fake;
685
686 if (numbufs == 0)
687 return;
688
689 for (i = 0; i < numbufs; i++) {
690 if (dbp[i])
691 dbuf_rele(dbp[i], tag);
692 }
693
694 kmem_free(dbp, sizeof (dmu_buf_t *) * numbufs);
695 }
696
697 /*
698 * Issue prefetch I/Os for the given blocks. If level is greater than 0, the
699 * indirect blocks prefetched will be those that point to the blocks containing
700 * the data starting at offset, and continuing to offset + len. If the range
701 * it too long, prefetch the first dmu_prefetch_max bytes as requested, while
702 * for the rest only a higher level, also fitting within dmu_prefetch_max. It
703 * should primarily help random reads, since for long sequential reads there is
704 * a speculative prefetcher.
705 *
706 * Note that if the indirect blocks above the blocks being prefetched are not
707 * in cache, they will be asynchronously read in. Dnode read by dnode_hold()
708 * is currently synchronous.
709 */
710 void
711 dmu_prefetch(objset_t *os, uint64_t object, int64_t level, uint64_t offset,
712 uint64_t len, zio_priority_t pri)
713 {
714 dnode_t *dn;
715
716 if (dmu_prefetch_max == 0 || len == 0) {
717 dmu_prefetch_dnode(os, object, pri);
718 return;
719 }
720
721 if (dnode_hold(os, object, FTAG, &dn) != 0)
722 return;
723
724 dmu_prefetch_by_dnode(dn, level, offset, len, pri);
725
726 dnode_rele(dn, FTAG);
727 }
728
729 void
730 dmu_prefetch_by_dnode(dnode_t *dn, int64_t level, uint64_t offset,
731 uint64_t len, zio_priority_t pri)
732 {
733 int64_t level2 = level;
734 uint64_t start, end, start2, end2;
735
736 /*
737 * Depending on len we may do two prefetches: blocks [start, end) at
738 * level, and following blocks [start2, end2) at higher level2.
739 */
740 rw_enter(&dn->dn_struct_rwlock, RW_READER);
741 if (dn->dn_datablkshift != 0) {
742 /*
743 * The object has multiple blocks. Calculate the full range
744 * of blocks [start, end2) and then split it into two parts,
745 * so that the first [start, end) fits into dmu_prefetch_max.
746 */
747 start = dbuf_whichblock(dn, level, offset);
748 end2 = dbuf_whichblock(dn, level, offset + len - 1) + 1;
749 uint8_t ibs = dn->dn_indblkshift;
750 uint8_t bs = (level == 0) ? dn->dn_datablkshift : ibs;
751 uint_t limit = P2ROUNDUP(dmu_prefetch_max, 1 << bs) >> bs;
752 start2 = end = MIN(end2, start + limit);
753
754 /*
755 * Find level2 where [start2, end2) fits into dmu_prefetch_max.
756 */
757 uint8_t ibps = ibs - SPA_BLKPTRSHIFT;
758 limit = P2ROUNDUP(dmu_prefetch_max, 1 << ibs) >> ibs;
759 do {
760 level2++;
761 start2 = P2ROUNDUP(start2, 1 << ibps) >> ibps;
762 end2 = P2ROUNDUP(end2, 1 << ibps) >> ibps;
763 } while (end2 - start2 > limit);
764 } else {
765 /* There is only one block. Prefetch it or nothing. */
766 start = start2 = end2 = 0;
767 end = start + (level == 0 && offset < dn->dn_datablksz);
768 }
769
770 for (uint64_t i = start; i < end; i++)
771 dbuf_prefetch(dn, level, i, pri, 0);
772 for (uint64_t i = start2; i < end2; i++)
773 dbuf_prefetch(dn, level2, i, pri, 0);
774 rw_exit(&dn->dn_struct_rwlock);
775 }
776
777 /*
778 * Issue prefetch I/Os for the given object's dnode.
779 */
780 void
781 dmu_prefetch_dnode(objset_t *os, uint64_t object, zio_priority_t pri)
782 {
783 if (object == 0 || object >= DN_MAX_OBJECT)
784 return;
785
786 dnode_t *dn = DMU_META_DNODE(os);
787 rw_enter(&dn->dn_struct_rwlock, RW_READER);
788 uint64_t blkid = dbuf_whichblock(dn, 0, object * sizeof (dnode_phys_t));
789 dbuf_prefetch(dn, 0, blkid, pri, 0);
790 rw_exit(&dn->dn_struct_rwlock);
791 }
792
793 /*
794 * Get the next "chunk" of file data to free. We traverse the file from
795 * the end so that the file gets shorter over time (if we crashes in the
796 * middle, this will leave us in a better state). We find allocated file
797 * data by simply searching the allocated level 1 indirects.
798 *
799 * On input, *start should be the first offset that does not need to be
800 * freed (e.g. "offset + length"). On return, *start will be the first
801 * offset that should be freed and l1blks is set to the number of level 1
802 * indirect blocks found within the chunk.
803 */
804 static int
805 get_next_chunk(dnode_t *dn, uint64_t *start, uint64_t minimum, uint64_t *l1blks)
806 {
807 uint64_t blks;
808 uint64_t maxblks = DMU_MAX_ACCESS >> (dn->dn_indblkshift + 1);
809 /* bytes of data covered by a level-1 indirect block */
810 uint64_t iblkrange = (uint64_t)dn->dn_datablksz *
811 EPB(dn->dn_indblkshift, SPA_BLKPTRSHIFT);
812
813 ASSERT3U(minimum, <=, *start);
814
815 /*
816 * Check if we can free the entire range assuming that all of the
817 * L1 blocks in this range have data. If we can, we use this
818 * worst case value as an estimate so we can avoid having to look
819 * at the object's actual data.
820 */
821 uint64_t total_l1blks =
822 (roundup(*start, iblkrange) - (minimum / iblkrange * iblkrange)) /
823 iblkrange;
824 if (total_l1blks <= maxblks) {
825 *l1blks = total_l1blks;
826 *start = minimum;
827 return (0);
828 }
829 ASSERT(ISP2(iblkrange));
830
831 for (blks = 0; *start > minimum && blks < maxblks; blks++) {
832 int err;
833
834 /*
835 * dnode_next_offset(BACKWARDS) will find an allocated L1
836 * indirect block at or before the input offset. We must
837 * decrement *start so that it is at the end of the region
838 * to search.
839 */
840 (*start)--;
841
842 err = dnode_next_offset(dn,
843 DNODE_FIND_BACKWARDS, start, 2, 1, 0);
844
845 /* if there are no indirect blocks before start, we are done */
846 if (err == ESRCH) {
847 *start = minimum;
848 break;
849 } else if (err != 0) {
850 *l1blks = blks;
851 return (err);
852 }
853
854 /* set start to the beginning of this L1 indirect */
855 *start = P2ALIGN(*start, iblkrange);
856 }
857 if (*start < minimum)
858 *start = minimum;
859 *l1blks = blks;
860
861 return (0);
862 }
863
864 /*
865 * If this objset is of type OST_ZFS return true if vfs's unmounted flag is set,
866 * otherwise return false.
867 * Used below in dmu_free_long_range_impl() to enable abort when unmounting
868 */
869 static boolean_t
870 dmu_objset_zfs_unmounting(objset_t *os)
871 {
872 #ifdef _KERNEL
873 if (dmu_objset_type(os) == DMU_OST_ZFS)
874 return (zfs_get_vfs_flag_unmounted(os));
875 #else
876 (void) os;
877 #endif
878 return (B_FALSE);
879 }
880
881 static int
882 dmu_free_long_range_impl(objset_t *os, dnode_t *dn, uint64_t offset,
883 uint64_t length)
884 {
885 uint64_t object_size;
886 int err;
887 uint64_t dirty_frees_threshold;
888 dsl_pool_t *dp = dmu_objset_pool(os);
889
890 if (dn == NULL)
891 return (SET_ERROR(EINVAL));
892
893 object_size = (dn->dn_maxblkid + 1) * dn->dn_datablksz;
894 if (offset >= object_size)
895 return (0);
896
897 if (zfs_per_txg_dirty_frees_percent <= 100)
898 dirty_frees_threshold =
899 zfs_per_txg_dirty_frees_percent * zfs_dirty_data_max / 100;
900 else
901 dirty_frees_threshold = zfs_dirty_data_max / 20;
902
903 if (length == DMU_OBJECT_END || offset + length > object_size)
904 length = object_size - offset;
905
906 while (length != 0) {
907 uint64_t chunk_end, chunk_begin, chunk_len;
908 uint64_t l1blks;
909 dmu_tx_t *tx;
910
911 if (dmu_objset_zfs_unmounting(dn->dn_objset))
912 return (SET_ERROR(EINTR));
913
914 chunk_end = chunk_begin = offset + length;
915
916 /* move chunk_begin backwards to the beginning of this chunk */
917 err = get_next_chunk(dn, &chunk_begin, offset, &l1blks);
918 if (err)
919 return (err);
920 ASSERT3U(chunk_begin, >=, offset);
921 ASSERT3U(chunk_begin, <=, chunk_end);
922
923 chunk_len = chunk_end - chunk_begin;
924
925 tx = dmu_tx_create(os);
926 dmu_tx_hold_free(tx, dn->dn_object, chunk_begin, chunk_len);
927
928 /*
929 * Mark this transaction as typically resulting in a net
930 * reduction in space used.
931 */
932 dmu_tx_mark_netfree(tx);
933 err = dmu_tx_assign(tx, TXG_WAIT);
934 if (err) {
935 dmu_tx_abort(tx);
936 return (err);
937 }
938
939 uint64_t txg = dmu_tx_get_txg(tx);
940
941 mutex_enter(&dp->dp_lock);
942 uint64_t long_free_dirty =
943 dp->dp_long_free_dirty_pertxg[txg & TXG_MASK];
944 mutex_exit(&dp->dp_lock);
945
946 /*
947 * To avoid filling up a TXG with just frees, wait for
948 * the next TXG to open before freeing more chunks if
949 * we have reached the threshold of frees.
950 */
951 if (dirty_frees_threshold != 0 &&
952 long_free_dirty >= dirty_frees_threshold) {
953 DMU_TX_STAT_BUMP(dmu_tx_dirty_frees_delay);
954 dmu_tx_commit(tx);
955 txg_wait_open(dp, 0, B_TRUE);
956 continue;
957 }
958
959 /*
960 * In order to prevent unnecessary write throttling, for each
961 * TXG, we track the cumulative size of L1 blocks being dirtied
962 * in dnode_free_range() below. We compare this number to a
963 * tunable threshold, past which we prevent new L1 dirty freeing
964 * blocks from being added into the open TXG. See
965 * dmu_free_long_range_impl() for details. The threshold
966 * prevents write throttle activation due to dirty freeing L1
967 * blocks taking up a large percentage of zfs_dirty_data_max.
968 */
969 mutex_enter(&dp->dp_lock);
970 dp->dp_long_free_dirty_pertxg[txg & TXG_MASK] +=
971 l1blks << dn->dn_indblkshift;
972 mutex_exit(&dp->dp_lock);
973 DTRACE_PROBE3(free__long__range,
974 uint64_t, long_free_dirty, uint64_t, chunk_len,
975 uint64_t, txg);
976 dnode_free_range(dn, chunk_begin, chunk_len, tx);
977
978 dmu_tx_commit(tx);
979
980 length -= chunk_len;
981 }
982 return (0);
983 }
984
985 int
986 dmu_free_long_range(objset_t *os, uint64_t object,
987 uint64_t offset, uint64_t length)
988 {
989 dnode_t *dn;
990 int err;
991
992 err = dnode_hold(os, object, FTAG, &dn);
993 if (err != 0)
994 return (err);
995 err = dmu_free_long_range_impl(os, dn, offset, length);
996
997 /*
998 * It is important to zero out the maxblkid when freeing the entire
999 * file, so that (a) subsequent calls to dmu_free_long_range_impl()
1000 * will take the fast path, and (b) dnode_reallocate() can verify
1001 * that the entire file has been freed.
1002 */
1003 if (err == 0 && offset == 0 && length == DMU_OBJECT_END)
1004 dn->dn_maxblkid = 0;
1005
1006 dnode_rele(dn, FTAG);
1007 return (err);
1008 }
1009
1010 int
1011 dmu_free_long_object(objset_t *os, uint64_t object)
1012 {
1013 dmu_tx_t *tx;
1014 int err;
1015
1016 err = dmu_free_long_range(os, object, 0, DMU_OBJECT_END);
1017 if (err != 0)
1018 return (err);
1019
1020 tx = dmu_tx_create(os);
1021 dmu_tx_hold_bonus(tx, object);
1022 dmu_tx_hold_free(tx, object, 0, DMU_OBJECT_END);
1023 dmu_tx_mark_netfree(tx);
1024 err = dmu_tx_assign(tx, TXG_WAIT);
1025 if (err == 0) {
1026 err = dmu_object_free(os, object, tx);
1027 dmu_tx_commit(tx);
1028 } else {
1029 dmu_tx_abort(tx);
1030 }
1031
1032 return (err);
1033 }
1034
1035 int
1036 dmu_free_range(objset_t *os, uint64_t object, uint64_t offset,
1037 uint64_t size, dmu_tx_t *tx)
1038 {
1039 dnode_t *dn;
1040 int err = dnode_hold(os, object, FTAG, &dn);
1041 if (err)
1042 return (err);
1043 ASSERT(offset < UINT64_MAX);
1044 ASSERT(size == DMU_OBJECT_END || size <= UINT64_MAX - offset);
1045 dnode_free_range(dn, offset, size, tx);
1046 dnode_rele(dn, FTAG);
1047 return (0);
1048 }
1049
1050 static int
1051 dmu_read_impl(dnode_t *dn, uint64_t offset, uint64_t size,
1052 void *buf, uint32_t flags)
1053 {
1054 dmu_buf_t **dbp;
1055 int numbufs, err = 0;
1056
1057 /*
1058 * Deal with odd block sizes, where there can't be data past the first
1059 * block. If we ever do the tail block optimization, we will need to
1060 * handle that here as well.
1061 */
1062 if (dn->dn_maxblkid == 0) {
1063 uint64_t newsz = offset > dn->dn_datablksz ? 0 :
1064 MIN(size, dn->dn_datablksz - offset);
1065 memset((char *)buf + newsz, 0, size - newsz);
1066 size = newsz;
1067 }
1068
1069 while (size > 0) {
1070 uint64_t mylen = MIN(size, DMU_MAX_ACCESS / 2);
1071 int i;
1072
1073 /*
1074 * NB: we could do this block-at-a-time, but it's nice
1075 * to be reading in parallel.
1076 */
1077 err = dmu_buf_hold_array_by_dnode(dn, offset, mylen,
1078 TRUE, FTAG, &numbufs, &dbp, flags);
1079 if (err)
1080 break;
1081
1082 for (i = 0; i < numbufs; i++) {
1083 uint64_t tocpy;
1084 int64_t bufoff;
1085 dmu_buf_t *db = dbp[i];
1086
1087 ASSERT(size > 0);
1088
1089 bufoff = offset - db->db_offset;
1090 tocpy = MIN(db->db_size - bufoff, size);
1091
1092 (void) memcpy(buf, (char *)db->db_data + bufoff, tocpy);
1093
1094 offset += tocpy;
1095 size -= tocpy;
1096 buf = (char *)buf + tocpy;
1097 }
1098 dmu_buf_rele_array(dbp, numbufs, FTAG);
1099 }
1100 return (err);
1101 }
1102
1103 int
1104 dmu_read(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
1105 void *buf, uint32_t flags)
1106 {
1107 dnode_t *dn;
1108 int err;
1109
1110 err = dnode_hold(os, object, FTAG, &dn);
1111 if (err != 0)
1112 return (err);
1113
1114 err = dmu_read_impl(dn, offset, size, buf, flags);
1115 dnode_rele(dn, FTAG);
1116 return (err);
1117 }
1118
1119 int
1120 dmu_read_by_dnode(dnode_t *dn, uint64_t offset, uint64_t size, void *buf,
1121 uint32_t flags)
1122 {
1123 return (dmu_read_impl(dn, offset, size, buf, flags));
1124 }
1125
1126 static void
1127 dmu_write_impl(dmu_buf_t **dbp, int numbufs, uint64_t offset, uint64_t size,
1128 const void *buf, dmu_tx_t *tx)
1129 {
1130 int i;
1131
1132 for (i = 0; i < numbufs; i++) {
1133 uint64_t tocpy;
1134 int64_t bufoff;
1135 dmu_buf_t *db = dbp[i];
1136
1137 ASSERT(size > 0);
1138
1139 bufoff = offset - db->db_offset;
1140 tocpy = MIN(db->db_size - bufoff, size);
1141
1142 ASSERT(i == 0 || i == numbufs-1 || tocpy == db->db_size);
1143
1144 if (tocpy == db->db_size)
1145 dmu_buf_will_fill(db, tx, B_FALSE);
1146 else
1147 dmu_buf_will_dirty(db, tx);
1148
1149 (void) memcpy((char *)db->db_data + bufoff, buf, tocpy);
1150
1151 if (tocpy == db->db_size)
1152 dmu_buf_fill_done(db, tx, B_FALSE);
1153
1154 offset += tocpy;
1155 size -= tocpy;
1156 buf = (char *)buf + tocpy;
1157 }
1158 }
1159
1160 void
1161 dmu_write(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
1162 const void *buf, dmu_tx_t *tx)
1163 {
1164 dmu_buf_t **dbp;
1165 int numbufs;
1166
1167 if (size == 0)
1168 return;
1169
1170 VERIFY0(dmu_buf_hold_array(os, object, offset, size,
1171 FALSE, FTAG, &numbufs, &dbp));
1172 dmu_write_impl(dbp, numbufs, offset, size, buf, tx);
1173 dmu_buf_rele_array(dbp, numbufs, FTAG);
1174 }
1175
1176 /*
1177 * Note: Lustre is an external consumer of this interface.
1178 */
1179 void
1180 dmu_write_by_dnode(dnode_t *dn, uint64_t offset, uint64_t size,
1181 const void *buf, dmu_tx_t *tx)
1182 {
1183 dmu_buf_t **dbp;
1184 int numbufs;
1185
1186 if (size == 0)
1187 return;
1188
1189 VERIFY0(dmu_buf_hold_array_by_dnode(dn, offset, size,
1190 FALSE, FTAG, &numbufs, &dbp, DMU_READ_PREFETCH));
1191 dmu_write_impl(dbp, numbufs, offset, size, buf, tx);
1192 dmu_buf_rele_array(dbp, numbufs, FTAG);
1193 }
1194
1195 void
1196 dmu_prealloc(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
1197 dmu_tx_t *tx)
1198 {
1199 dmu_buf_t **dbp;
1200 int numbufs, i;
1201
1202 if (size == 0)
1203 return;
1204
1205 VERIFY(0 == dmu_buf_hold_array(os, object, offset, size,
1206 FALSE, FTAG, &numbufs, &dbp));
1207
1208 for (i = 0; i < numbufs; i++) {
1209 dmu_buf_t *db = dbp[i];
1210
1211 dmu_buf_will_not_fill(db, tx);
1212 }
1213 dmu_buf_rele_array(dbp, numbufs, FTAG);
1214 }
1215
1216 void
1217 dmu_write_embedded(objset_t *os, uint64_t object, uint64_t offset,
1218 void *data, uint8_t etype, uint8_t comp, int uncompressed_size,
1219 int compressed_size, int byteorder, dmu_tx_t *tx)
1220 {
1221 dmu_buf_t *db;
1222
1223 ASSERT3U(etype, <, NUM_BP_EMBEDDED_TYPES);
1224 ASSERT3U(comp, <, ZIO_COMPRESS_FUNCTIONS);
1225 VERIFY0(dmu_buf_hold_noread(os, object, offset,
1226 FTAG, &db));
1227
1228 dmu_buf_write_embedded(db,
1229 data, (bp_embedded_type_t)etype, (enum zio_compress)comp,
1230 uncompressed_size, compressed_size, byteorder, tx);
1231
1232 dmu_buf_rele(db, FTAG);
1233 }
1234
1235 void
1236 dmu_redact(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
1237 dmu_tx_t *tx)
1238 {
1239 int numbufs, i;
1240 dmu_buf_t **dbp;
1241
1242 VERIFY0(dmu_buf_hold_array(os, object, offset, size, FALSE, FTAG,
1243 &numbufs, &dbp));
1244 for (i = 0; i < numbufs; i++)
1245 dmu_buf_redact(dbp[i], tx);
1246 dmu_buf_rele_array(dbp, numbufs, FTAG);
1247 }
1248
1249 #ifdef _KERNEL
1250 int
1251 dmu_read_uio_dnode(dnode_t *dn, zfs_uio_t *uio, uint64_t size)
1252 {
1253 dmu_buf_t **dbp;
1254 int numbufs, i, err;
1255
1256 /*
1257 * NB: we could do this block-at-a-time, but it's nice
1258 * to be reading in parallel.
1259 */
1260 err = dmu_buf_hold_array_by_dnode(dn, zfs_uio_offset(uio), size,
1261 TRUE, FTAG, &numbufs, &dbp, 0);
1262 if (err)
1263 return (err);
1264
1265 for (i = 0; i < numbufs; i++) {
1266 uint64_t tocpy;
1267 int64_t bufoff;
1268 dmu_buf_t *db = dbp[i];
1269
1270 ASSERT(size > 0);
1271
1272 bufoff = zfs_uio_offset(uio) - db->db_offset;
1273 tocpy = MIN(db->db_size - bufoff, size);
1274
1275 err = zfs_uio_fault_move((char *)db->db_data + bufoff, tocpy,
1276 UIO_READ, uio);
1277
1278 if (err)
1279 break;
1280
1281 size -= tocpy;
1282 }
1283 dmu_buf_rele_array(dbp, numbufs, FTAG);
1284
1285 return (err);
1286 }
1287
1288 /*
1289 * Read 'size' bytes into the uio buffer.
1290 * From object zdb->db_object.
1291 * Starting at zfs_uio_offset(uio).
1292 *
1293 * If the caller already has a dbuf in the target object
1294 * (e.g. its bonus buffer), this routine is faster than dmu_read_uio(),
1295 * because we don't have to find the dnode_t for the object.
1296 */
1297 int
1298 dmu_read_uio_dbuf(dmu_buf_t *zdb, zfs_uio_t *uio, uint64_t size)
1299 {
1300 dmu_buf_impl_t *db = (dmu_buf_impl_t *)zdb;
1301 dnode_t *dn;
1302 int err;
1303
1304 if (size == 0)
1305 return (0);
1306
1307 DB_DNODE_ENTER(db);
1308 dn = DB_DNODE(db);
1309 err = dmu_read_uio_dnode(dn, uio, size);
1310 DB_DNODE_EXIT(db);
1311
1312 return (err);
1313 }
1314
1315 /*
1316 * Read 'size' bytes into the uio buffer.
1317 * From the specified object
1318 * Starting at offset zfs_uio_offset(uio).
1319 */
1320 int
1321 dmu_read_uio(objset_t *os, uint64_t object, zfs_uio_t *uio, uint64_t size)
1322 {
1323 dnode_t *dn;
1324 int err;
1325
1326 if (size == 0)
1327 return (0);
1328
1329 err = dnode_hold(os, object, FTAG, &dn);
1330 if (err)
1331 return (err);
1332
1333 err = dmu_read_uio_dnode(dn, uio, size);
1334
1335 dnode_rele(dn, FTAG);
1336
1337 return (err);
1338 }
1339
1340 int
1341 dmu_write_uio_dnode(dnode_t *dn, zfs_uio_t *uio, uint64_t size, dmu_tx_t *tx)
1342 {
1343 dmu_buf_t **dbp;
1344 int numbufs;
1345 int err = 0;
1346 int i;
1347
1348 err = dmu_buf_hold_array_by_dnode(dn, zfs_uio_offset(uio), size,
1349 FALSE, FTAG, &numbufs, &dbp, DMU_READ_PREFETCH);
1350 if (err)
1351 return (err);
1352
1353 for (i = 0; i < numbufs; i++) {
1354 uint64_t tocpy;
1355 int64_t bufoff;
1356 dmu_buf_t *db = dbp[i];
1357
1358 ASSERT(size > 0);
1359
1360 offset_t off = zfs_uio_offset(uio);
1361 bufoff = off - db->db_offset;
1362 tocpy = MIN(db->db_size - bufoff, size);
1363
1364 ASSERT(i == 0 || i == numbufs-1 || tocpy == db->db_size);
1365
1366 if (tocpy == db->db_size)
1367 dmu_buf_will_fill(db, tx, B_TRUE);
1368 else
1369 dmu_buf_will_dirty(db, tx);
1370
1371 err = zfs_uio_fault_move((char *)db->db_data + bufoff,
1372 tocpy, UIO_WRITE, uio);
1373
1374 if (tocpy == db->db_size && dmu_buf_fill_done(db, tx, err)) {
1375 /* The fill was reverted. Undo any uio progress. */
1376 zfs_uio_advance(uio, off - zfs_uio_offset(uio));
1377 }
1378
1379 if (err)
1380 break;
1381
1382 size -= tocpy;
1383 }
1384
1385 dmu_buf_rele_array(dbp, numbufs, FTAG);
1386 return (err);
1387 }
1388
1389 /*
1390 * Write 'size' bytes from the uio buffer.
1391 * To object zdb->db_object.
1392 * Starting at offset zfs_uio_offset(uio).
1393 *
1394 * If the caller already has a dbuf in the target object
1395 * (e.g. its bonus buffer), this routine is faster than dmu_write_uio(),
1396 * because we don't have to find the dnode_t for the object.
1397 */
1398 int
1399 dmu_write_uio_dbuf(dmu_buf_t *zdb, zfs_uio_t *uio, uint64_t size,
1400 dmu_tx_t *tx)
1401 {
1402 dmu_buf_impl_t *db = (dmu_buf_impl_t *)zdb;
1403 dnode_t *dn;
1404 int err;
1405
1406 if (size == 0)
1407 return (0);
1408
1409 DB_DNODE_ENTER(db);
1410 dn = DB_DNODE(db);
1411 err = dmu_write_uio_dnode(dn, uio, size, tx);
1412 DB_DNODE_EXIT(db);
1413
1414 return (err);
1415 }
1416
1417 /*
1418 * Write 'size' bytes from the uio buffer.
1419 * To the specified object.
1420 * Starting at offset zfs_uio_offset(uio).
1421 */
1422 int
1423 dmu_write_uio(objset_t *os, uint64_t object, zfs_uio_t *uio, uint64_t size,
1424 dmu_tx_t *tx)
1425 {
1426 dnode_t *dn;
1427 int err;
1428
1429 if (size == 0)
1430 return (0);
1431
1432 err = dnode_hold(os, object, FTAG, &dn);
1433 if (err)
1434 return (err);
1435
1436 err = dmu_write_uio_dnode(dn, uio, size, tx);
1437
1438 dnode_rele(dn, FTAG);
1439
1440 return (err);
1441 }
1442 #endif /* _KERNEL */
1443
1444 /*
1445 * Allocate a loaned anonymous arc buffer.
1446 */
1447 arc_buf_t *
1448 dmu_request_arcbuf(dmu_buf_t *handle, int size)
1449 {
1450 dmu_buf_impl_t *db = (dmu_buf_impl_t *)handle;
1451
1452 return (arc_loan_buf(db->db_objset->os_spa, B_FALSE, size));
1453 }
1454
1455 /*
1456 * Free a loaned arc buffer.
1457 */
1458 void
1459 dmu_return_arcbuf(arc_buf_t *buf)
1460 {
1461 arc_return_buf(buf, FTAG);
1462 arc_buf_destroy(buf, FTAG);
1463 }
1464
1465 /*
1466 * A "lightweight" write is faster than a regular write (e.g.
1467 * dmu_write_by_dnode() or dmu_assign_arcbuf_by_dnode()), because it avoids the
1468 * CPU cost of creating a dmu_buf_impl_t and arc_buf_[hdr_]_t. However, the
1469 * data can not be read or overwritten until the transaction's txg has been
1470 * synced. This makes it appropriate for workloads that are known to be
1471 * (temporarily) write-only, like "zfs receive".
1472 *
1473 * A single block is written, starting at the specified offset in bytes. If
1474 * the call is successful, it returns 0 and the provided abd has been
1475 * consumed (the caller should not free it).
1476 */
1477 int
1478 dmu_lightweight_write_by_dnode(dnode_t *dn, uint64_t offset, abd_t *abd,
1479 const zio_prop_t *zp, zio_flag_t flags, dmu_tx_t *tx)
1480 {
1481 dbuf_dirty_record_t *dr =
1482 dbuf_dirty_lightweight(dn, dbuf_whichblock(dn, 0, offset), tx);
1483 if (dr == NULL)
1484 return (SET_ERROR(EIO));
1485 dr->dt.dll.dr_abd = abd;
1486 dr->dt.dll.dr_props = *zp;
1487 dr->dt.dll.dr_flags = flags;
1488 return (0);
1489 }
1490
1491 /*
1492 * When possible directly assign passed loaned arc buffer to a dbuf.
1493 * If this is not possible copy the contents of passed arc buf via
1494 * dmu_write().
1495 */
1496 int
1497 dmu_assign_arcbuf_by_dnode(dnode_t *dn, uint64_t offset, arc_buf_t *buf,
1498 dmu_tx_t *tx)
1499 {
1500 dmu_buf_impl_t *db;
1501 objset_t *os = dn->dn_objset;
1502 uint64_t object = dn->dn_object;
1503 uint32_t blksz = (uint32_t)arc_buf_lsize(buf);
1504 uint64_t blkid;
1505
1506 rw_enter(&dn->dn_struct_rwlock, RW_READER);
1507 blkid = dbuf_whichblock(dn, 0, offset);
1508 db = dbuf_hold(dn, blkid, FTAG);
1509 rw_exit(&dn->dn_struct_rwlock);
1510 if (db == NULL)
1511 return (SET_ERROR(EIO));
1512
1513 /*
1514 * We can only assign if the offset is aligned and the arc buf is the
1515 * same size as the dbuf.
1516 */
1517 if (offset == db->db.db_offset && blksz == db->db.db_size) {
1518 zfs_racct_write(blksz, 1);
1519 dbuf_assign_arcbuf(db, buf, tx);
1520 dbuf_rele(db, FTAG);
1521 } else {
1522 /* compressed bufs must always be assignable to their dbuf */
1523 ASSERT3U(arc_get_compression(buf), ==, ZIO_COMPRESS_OFF);
1524 ASSERT(!(buf->b_flags & ARC_BUF_FLAG_COMPRESSED));
1525
1526 dbuf_rele(db, FTAG);
1527 dmu_write(os, object, offset, blksz, buf->b_data, tx);
1528 dmu_return_arcbuf(buf);
1529 }
1530
1531 return (0);
1532 }
1533
1534 int
1535 dmu_assign_arcbuf_by_dbuf(dmu_buf_t *handle, uint64_t offset, arc_buf_t *buf,
1536 dmu_tx_t *tx)
1537 {
1538 int err;
1539 dmu_buf_impl_t *dbuf = (dmu_buf_impl_t *)handle;
1540
1541 DB_DNODE_ENTER(dbuf);
1542 err = dmu_assign_arcbuf_by_dnode(DB_DNODE(dbuf), offset, buf, tx);
1543 DB_DNODE_EXIT(dbuf);
1544
1545 return (err);
1546 }
1547
1548 typedef struct {
1549 dbuf_dirty_record_t *dsa_dr;
1550 dmu_sync_cb_t *dsa_done;
1551 zgd_t *dsa_zgd;
1552 dmu_tx_t *dsa_tx;
1553 } dmu_sync_arg_t;
1554
1555 static void
1556 dmu_sync_ready(zio_t *zio, arc_buf_t *buf, void *varg)
1557 {
1558 (void) buf;
1559 dmu_sync_arg_t *dsa = varg;
1560 dmu_buf_t *db = dsa->dsa_zgd->zgd_db;
1561 blkptr_t *bp = zio->io_bp;
1562
1563 if (zio->io_error == 0) {
1564 if (BP_IS_HOLE(bp)) {
1565 /*
1566 * A block of zeros may compress to a hole, but the
1567 * block size still needs to be known for replay.
1568 */
1569 BP_SET_LSIZE(bp, db->db_size);
1570 } else if (!BP_IS_EMBEDDED(bp)) {
1571 ASSERT(BP_GET_LEVEL(bp) == 0);
1572 BP_SET_FILL(bp, 1);
1573 }
1574 }
1575 }
1576
1577 static void
1578 dmu_sync_late_arrival_ready(zio_t *zio)
1579 {
1580 dmu_sync_ready(zio, NULL, zio->io_private);
1581 }
1582
1583 static void
1584 dmu_sync_done(zio_t *zio, arc_buf_t *buf, void *varg)
1585 {
1586 (void) buf;
1587 dmu_sync_arg_t *dsa = varg;
1588 dbuf_dirty_record_t *dr = dsa->dsa_dr;
1589 dmu_buf_impl_t *db = dr->dr_dbuf;
1590 zgd_t *zgd = dsa->dsa_zgd;
1591
1592 /*
1593 * Record the vdev(s) backing this blkptr so they can be flushed after
1594 * the writes for the lwb have completed.
1595 */
1596 if (zio->io_error == 0) {
1597 zil_lwb_add_block(zgd->zgd_lwb, zgd->zgd_bp);
1598 }
1599
1600 mutex_enter(&db->db_mtx);
1601 ASSERT(dr->dt.dl.dr_override_state == DR_IN_DMU_SYNC);
1602 if (zio->io_error == 0) {
1603 dr->dt.dl.dr_nopwrite = !!(zio->io_flags & ZIO_FLAG_NOPWRITE);
1604 if (dr->dt.dl.dr_nopwrite) {
1605 blkptr_t *bp = zio->io_bp;
1606 blkptr_t *bp_orig = &zio->io_bp_orig;
1607 uint8_t chksum = BP_GET_CHECKSUM(bp_orig);
1608
1609 ASSERT(BP_EQUAL(bp, bp_orig));
1610 VERIFY(BP_EQUAL(bp, db->db_blkptr));
1611 ASSERT(zio->io_prop.zp_compress != ZIO_COMPRESS_OFF);
1612 VERIFY(zio_checksum_table[chksum].ci_flags &
1613 ZCHECKSUM_FLAG_NOPWRITE);
1614 }
1615 dr->dt.dl.dr_overridden_by = *zio->io_bp;
1616 dr->dt.dl.dr_override_state = DR_OVERRIDDEN;
1617 dr->dt.dl.dr_copies = zio->io_prop.zp_copies;
1618
1619 /*
1620 * Old style holes are filled with all zeros, whereas
1621 * new-style holes maintain their lsize, type, level,
1622 * and birth time (see zio_write_compress). While we
1623 * need to reset the BP_SET_LSIZE() call that happened
1624 * in dmu_sync_ready for old style holes, we do *not*
1625 * want to wipe out the information contained in new
1626 * style holes. Thus, only zero out the block pointer if
1627 * it's an old style hole.
1628 */
1629 if (BP_IS_HOLE(&dr->dt.dl.dr_overridden_by) &&
1630 BP_GET_LOGICAL_BIRTH(&dr->dt.dl.dr_overridden_by) == 0)
1631 BP_ZERO(&dr->dt.dl.dr_overridden_by);
1632 } else {
1633 dr->dt.dl.dr_override_state = DR_NOT_OVERRIDDEN;
1634 }
1635 cv_broadcast(&db->db_changed);
1636 mutex_exit(&db->db_mtx);
1637
1638 dsa->dsa_done(dsa->dsa_zgd, zio->io_error);
1639
1640 kmem_free(dsa, sizeof (*dsa));
1641 }
1642
1643 static void
1644 dmu_sync_late_arrival_done(zio_t *zio)
1645 {
1646 blkptr_t *bp = zio->io_bp;
1647 dmu_sync_arg_t *dsa = zio->io_private;
1648 zgd_t *zgd = dsa->dsa_zgd;
1649
1650 if (zio->io_error == 0) {
1651 /*
1652 * Record the vdev(s) backing this blkptr so they can be
1653 * flushed after the writes for the lwb have completed.
1654 */
1655 zil_lwb_add_block(zgd->zgd_lwb, zgd->zgd_bp);
1656
1657 if (!BP_IS_HOLE(bp)) {
1658 blkptr_t *bp_orig __maybe_unused = &zio->io_bp_orig;
1659 ASSERT(!(zio->io_flags & ZIO_FLAG_NOPWRITE));
1660 ASSERT(BP_IS_HOLE(bp_orig) || !BP_EQUAL(bp, bp_orig));
1661 ASSERT(BP_GET_LOGICAL_BIRTH(zio->io_bp) == zio->io_txg);
1662 ASSERT(zio->io_txg > spa_syncing_txg(zio->io_spa));
1663 zio_free(zio->io_spa, zio->io_txg, zio->io_bp);
1664 }
1665 }
1666
1667 dmu_tx_commit(dsa->dsa_tx);
1668
1669 dsa->dsa_done(dsa->dsa_zgd, zio->io_error);
1670
1671 abd_free(zio->io_abd);
1672 kmem_free(dsa, sizeof (*dsa));
1673 }
1674
1675 static int
1676 dmu_sync_late_arrival(zio_t *pio, objset_t *os, dmu_sync_cb_t *done, zgd_t *zgd,
1677 zio_prop_t *zp, zbookmark_phys_t *zb)
1678 {
1679 dmu_sync_arg_t *dsa;
1680 dmu_tx_t *tx;
1681 int error;
1682
1683 error = dbuf_read((dmu_buf_impl_t *)zgd->zgd_db, NULL,
1684 DB_RF_CANFAIL | DB_RF_NOPREFETCH);
1685 if (error != 0)
1686 return (error);
1687
1688 tx = dmu_tx_create(os);
1689 dmu_tx_hold_space(tx, zgd->zgd_db->db_size);
1690 /*
1691 * This transaction does not produce any dirty data or log blocks, so
1692 * it should not be throttled. All other cases wait for TXG sync, by
1693 * which time the log block we are writing will be obsolete, so we can
1694 * skip waiting and just return error here instead.
1695 */
1696 if (dmu_tx_assign(tx, TXG_NOWAIT | TXG_NOTHROTTLE) != 0) {
1697 dmu_tx_abort(tx);
1698 /* Make zl_get_data do txg_waited_synced() */
1699 return (SET_ERROR(EIO));
1700 }
1701
1702 /*
1703 * In order to prevent the zgd's lwb from being free'd prior to
1704 * dmu_sync_late_arrival_done() being called, we have to ensure
1705 * the lwb's "max txg" takes this tx's txg into account.
1706 */
1707 zil_lwb_add_txg(zgd->zgd_lwb, dmu_tx_get_txg(tx));
1708
1709 dsa = kmem_alloc(sizeof (dmu_sync_arg_t), KM_SLEEP);
1710 dsa->dsa_dr = NULL;
1711 dsa->dsa_done = done;
1712 dsa->dsa_zgd = zgd;
1713 dsa->dsa_tx = tx;
1714
1715 /*
1716 * Since we are currently syncing this txg, it's nontrivial to
1717 * determine what BP to nopwrite against, so we disable nopwrite.
1718 *
1719 * When syncing, the db_blkptr is initially the BP of the previous
1720 * txg. We can not nopwrite against it because it will be changed
1721 * (this is similar to the non-late-arrival case where the dbuf is
1722 * dirty in a future txg).
1723 *
1724 * Then dbuf_write_ready() sets bp_blkptr to the location we will write.
1725 * We can not nopwrite against it because although the BP will not
1726 * (typically) be changed, the data has not yet been persisted to this
1727 * location.
1728 *
1729 * Finally, when dbuf_write_done() is called, it is theoretically
1730 * possible to always nopwrite, because the data that was written in
1731 * this txg is the same data that we are trying to write. However we
1732 * would need to check that this dbuf is not dirty in any future
1733 * txg's (as we do in the normal dmu_sync() path). For simplicity, we
1734 * don't nopwrite in this case.
1735 */
1736 zp->zp_nopwrite = B_FALSE;
1737
1738 zio_nowait(zio_write(pio, os->os_spa, dmu_tx_get_txg(tx), zgd->zgd_bp,
1739 abd_get_from_buf(zgd->zgd_db->db_data, zgd->zgd_db->db_size),
1740 zgd->zgd_db->db_size, zgd->zgd_db->db_size, zp,
1741 dmu_sync_late_arrival_ready, NULL, dmu_sync_late_arrival_done,
1742 dsa, ZIO_PRIORITY_SYNC_WRITE, ZIO_FLAG_CANFAIL, zb));
1743
1744 return (0);
1745 }
1746
1747 /*
1748 * Intent log support: sync the block associated with db to disk.
1749 * N.B. and XXX: the caller is responsible for making sure that the
1750 * data isn't changing while dmu_sync() is writing it.
1751 *
1752 * Return values:
1753 *
1754 * EEXIST: this txg has already been synced, so there's nothing to do.
1755 * The caller should not log the write.
1756 *
1757 * ENOENT: the block was dbuf_free_range()'d, so there's nothing to do.
1758 * The caller should not log the write.
1759 *
1760 * EALREADY: this block is already in the process of being synced.
1761 * The caller should track its progress (somehow).
1762 *
1763 * EIO: could not do the I/O.
1764 * The caller should do a txg_wait_synced().
1765 *
1766 * 0: the I/O has been initiated.
1767 * The caller should log this blkptr in the done callback.
1768 * It is possible that the I/O will fail, in which case
1769 * the error will be reported to the done callback and
1770 * propagated to pio from zio_done().
1771 */
1772 int
1773 dmu_sync(zio_t *pio, uint64_t txg, dmu_sync_cb_t *done, zgd_t *zgd)
1774 {
1775 dmu_buf_impl_t *db = (dmu_buf_impl_t *)zgd->zgd_db;
1776 objset_t *os = db->db_objset;
1777 dsl_dataset_t *ds = os->os_dsl_dataset;
1778 dbuf_dirty_record_t *dr, *dr_next;
1779 dmu_sync_arg_t *dsa;
1780 zbookmark_phys_t zb;
1781 zio_prop_t zp;
1782 dnode_t *dn;
1783
1784 ASSERT(pio != NULL);
1785 ASSERT(txg != 0);
1786
1787 SET_BOOKMARK(&zb, ds->ds_object,
1788 db->db.db_object, db->db_level, db->db_blkid);
1789
1790 DB_DNODE_ENTER(db);
1791 dn = DB_DNODE(db);
1792 dmu_write_policy(os, dn, db->db_level, WP_DMU_SYNC, &zp);
1793 DB_DNODE_EXIT(db);
1794
1795 /*
1796 * If we're frozen (running ziltest), we always need to generate a bp.
1797 */
1798 if (txg > spa_freeze_txg(os->os_spa))
1799 return (dmu_sync_late_arrival(pio, os, done, zgd, &zp, &zb));
1800
1801 /*
1802 * Grabbing db_mtx now provides a barrier between dbuf_sync_leaf()
1803 * and us. If we determine that this txg is not yet syncing,
1804 * but it begins to sync a moment later, that's OK because the
1805 * sync thread will block in dbuf_sync_leaf() until we drop db_mtx.
1806 */
1807 mutex_enter(&db->db_mtx);
1808
1809 if (txg <= spa_last_synced_txg(os->os_spa)) {
1810 /*
1811 * This txg has already synced. There's nothing to do.
1812 */
1813 mutex_exit(&db->db_mtx);
1814 return (SET_ERROR(EEXIST));
1815 }
1816
1817 if (txg <= spa_syncing_txg(os->os_spa)) {
1818 /*
1819 * This txg is currently syncing, so we can't mess with
1820 * the dirty record anymore; just write a new log block.
1821 */
1822 mutex_exit(&db->db_mtx);
1823 return (dmu_sync_late_arrival(pio, os, done, zgd, &zp, &zb));
1824 }
1825
1826 dr = dbuf_find_dirty_eq(db, txg);
1827
1828 if (dr == NULL) {
1829 /*
1830 * There's no dr for this dbuf, so it must have been freed.
1831 * There's no need to log writes to freed blocks, so we're done.
1832 */
1833 mutex_exit(&db->db_mtx);
1834 return (SET_ERROR(ENOENT));
1835 }
1836
1837 dr_next = list_next(&db->db_dirty_records, dr);
1838 ASSERT(dr_next == NULL || dr_next->dr_txg < txg);
1839
1840 if (db->db_blkptr != NULL) {
1841 /*
1842 * We need to fill in zgd_bp with the current blkptr so that
1843 * the nopwrite code can check if we're writing the same
1844 * data that's already on disk. We can only nopwrite if we
1845 * are sure that after making the copy, db_blkptr will not
1846 * change until our i/o completes. We ensure this by
1847 * holding the db_mtx, and only allowing nopwrite if the
1848 * block is not already dirty (see below). This is verified
1849 * by dmu_sync_done(), which VERIFYs that the db_blkptr has
1850 * not changed.
1851 */
1852 *zgd->zgd_bp = *db->db_blkptr;
1853 }
1854
1855 /*
1856 * Assume the on-disk data is X, the current syncing data (in
1857 * txg - 1) is Y, and the current in-memory data is Z (currently
1858 * in dmu_sync).
1859 *
1860 * We usually want to perform a nopwrite if X and Z are the
1861 * same. However, if Y is different (i.e. the BP is going to
1862 * change before this write takes effect), then a nopwrite will
1863 * be incorrect - we would override with X, which could have
1864 * been freed when Y was written.
1865 *
1866 * (Note that this is not a concern when we are nop-writing from
1867 * syncing context, because X and Y must be identical, because
1868 * all previous txgs have been synced.)
1869 *
1870 * Therefore, we disable nopwrite if the current BP could change
1871 * before this TXG. There are two ways it could change: by
1872 * being dirty (dr_next is non-NULL), or by being freed
1873 * (dnode_block_freed()). This behavior is verified by
1874 * zio_done(), which VERIFYs that the override BP is identical
1875 * to the on-disk BP.
1876 */
1877 DB_DNODE_ENTER(db);
1878 dn = DB_DNODE(db);
1879 if (dr_next != NULL || dnode_block_freed(dn, db->db_blkid))
1880 zp.zp_nopwrite = B_FALSE;
1881 DB_DNODE_EXIT(db);
1882
1883 ASSERT(dr->dr_txg == txg);
1884 if (dr->dt.dl.dr_override_state == DR_IN_DMU_SYNC ||
1885 dr->dt.dl.dr_override_state == DR_OVERRIDDEN) {
1886 /*
1887 * We have already issued a sync write for this buffer,
1888 * or this buffer has already been synced. It could not
1889 * have been dirtied since, or we would have cleared the state.
1890 */
1891 mutex_exit(&db->db_mtx);
1892 return (SET_ERROR(EALREADY));
1893 }
1894
1895 ASSERT(dr->dt.dl.dr_override_state == DR_NOT_OVERRIDDEN);
1896 dr->dt.dl.dr_override_state = DR_IN_DMU_SYNC;
1897 mutex_exit(&db->db_mtx);
1898
1899 dsa = kmem_alloc(sizeof (dmu_sync_arg_t), KM_SLEEP);
1900 dsa->dsa_dr = dr;
1901 dsa->dsa_done = done;
1902 dsa->dsa_zgd = zgd;
1903 dsa->dsa_tx = NULL;
1904
1905 zio_nowait(arc_write(pio, os->os_spa, txg, zgd->zgd_bp,
1906 dr->dt.dl.dr_data, !DBUF_IS_CACHEABLE(db), dbuf_is_l2cacheable(db),
1907 &zp, dmu_sync_ready, NULL, dmu_sync_done, dsa,
1908 ZIO_PRIORITY_SYNC_WRITE, ZIO_FLAG_CANFAIL, &zb));
1909
1910 return (0);
1911 }
1912
1913 int
1914 dmu_object_set_nlevels(objset_t *os, uint64_t object, int nlevels, dmu_tx_t *tx)
1915 {
1916 dnode_t *dn;
1917 int err;
1918
1919 err = dnode_hold(os, object, FTAG, &dn);
1920 if (err)
1921 return (err);
1922 err = dnode_set_nlevels(dn, nlevels, tx);
1923 dnode_rele(dn, FTAG);
1924 return (err);
1925 }
1926
1927 int
1928 dmu_object_set_blocksize(objset_t *os, uint64_t object, uint64_t size, int ibs,
1929 dmu_tx_t *tx)
1930 {
1931 dnode_t *dn;
1932 int err;
1933
1934 err = dnode_hold(os, object, FTAG, &dn);
1935 if (err)
1936 return (err);
1937 err = dnode_set_blksz(dn, size, ibs, tx);
1938 dnode_rele(dn, FTAG);
1939 return (err);
1940 }
1941
1942 int
1943 dmu_object_set_maxblkid(objset_t *os, uint64_t object, uint64_t maxblkid,
1944 dmu_tx_t *tx)
1945 {
1946 dnode_t *dn;
1947 int err;
1948
1949 err = dnode_hold(os, object, FTAG, &dn);
1950 if (err)
1951 return (err);
1952 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
1953 dnode_new_blkid(dn, maxblkid, tx, B_FALSE, B_TRUE);
1954 rw_exit(&dn->dn_struct_rwlock);
1955 dnode_rele(dn, FTAG);
1956 return (0);
1957 }
1958
1959 void
1960 dmu_object_set_checksum(objset_t *os, uint64_t object, uint8_t checksum,
1961 dmu_tx_t *tx)
1962 {
1963 dnode_t *dn;
1964
1965 /*
1966 * Send streams include each object's checksum function. This
1967 * check ensures that the receiving system can understand the
1968 * checksum function transmitted.
1969 */
1970 ASSERT3U(checksum, <, ZIO_CHECKSUM_LEGACY_FUNCTIONS);
1971
1972 VERIFY0(dnode_hold(os, object, FTAG, &dn));
1973 ASSERT3U(checksum, <, ZIO_CHECKSUM_FUNCTIONS);
1974 dn->dn_checksum = checksum;
1975 dnode_setdirty(dn, tx);
1976 dnode_rele(dn, FTAG);
1977 }
1978
1979 void
1980 dmu_object_set_compress(objset_t *os, uint64_t object, uint8_t compress,
1981 dmu_tx_t *tx)
1982 {
1983 dnode_t *dn;
1984
1985 /*
1986 * Send streams include each object's compression function. This
1987 * check ensures that the receiving system can understand the
1988 * compression function transmitted.
1989 */
1990 ASSERT3U(compress, <, ZIO_COMPRESS_LEGACY_FUNCTIONS);
1991
1992 VERIFY0(dnode_hold(os, object, FTAG, &dn));
1993 dn->dn_compress = compress;
1994 dnode_setdirty(dn, tx);
1995 dnode_rele(dn, FTAG);
1996 }
1997
1998 /*
1999 * When the "redundant_metadata" property is set to "most", only indirect
2000 * blocks of this level and higher will have an additional ditto block.
2001 */
2002 static const int zfs_redundant_metadata_most_ditto_level = 2;
2003
2004 void
2005 dmu_write_policy(objset_t *os, dnode_t *dn, int level, int wp, zio_prop_t *zp)
2006 {
2007 dmu_object_type_t type = dn ? dn->dn_type : DMU_OT_OBJSET;
2008 boolean_t ismd = (level > 0 || DMU_OT_IS_METADATA(type) ||
2009 (wp & WP_SPILL));
2010 enum zio_checksum checksum = os->os_checksum;
2011 enum zio_compress compress = os->os_compress;
2012 uint8_t complevel = os->os_complevel;
2013 enum zio_checksum dedup_checksum = os->os_dedup_checksum;
2014 boolean_t dedup = B_FALSE;
2015 boolean_t nopwrite = B_FALSE;
2016 boolean_t dedup_verify = os->os_dedup_verify;
2017 boolean_t encrypt = B_FALSE;
2018 int copies = os->os_copies;
2019
2020 /*
2021 * We maintain different write policies for each of the following
2022 * types of data:
2023 * 1. metadata
2024 * 2. preallocated blocks (i.e. level-0 blocks of a dump device)
2025 * 3. all other level 0 blocks
2026 */
2027 if (ismd) {
2028 /*
2029 * XXX -- we should design a compression algorithm
2030 * that specializes in arrays of bps.
2031 */
2032 compress = zio_compress_select(os->os_spa,
2033 ZIO_COMPRESS_ON, ZIO_COMPRESS_ON);
2034
2035 /*
2036 * Metadata always gets checksummed. If the data
2037 * checksum is multi-bit correctable, and it's not a
2038 * ZBT-style checksum, then it's suitable for metadata
2039 * as well. Otherwise, the metadata checksum defaults
2040 * to fletcher4.
2041 */
2042 if (!(zio_checksum_table[checksum].ci_flags &
2043 ZCHECKSUM_FLAG_METADATA) ||
2044 (zio_checksum_table[checksum].ci_flags &
2045 ZCHECKSUM_FLAG_EMBEDDED))
2046 checksum = ZIO_CHECKSUM_FLETCHER_4;
2047
2048 switch (os->os_redundant_metadata) {
2049 case ZFS_REDUNDANT_METADATA_ALL:
2050 copies++;
2051 break;
2052 case ZFS_REDUNDANT_METADATA_MOST:
2053 if (level >= zfs_redundant_metadata_most_ditto_level ||
2054 DMU_OT_IS_METADATA(type) || (wp & WP_SPILL))
2055 copies++;
2056 break;
2057 case ZFS_REDUNDANT_METADATA_SOME:
2058 if (DMU_OT_IS_CRITICAL(type))
2059 copies++;
2060 break;
2061 case ZFS_REDUNDANT_METADATA_NONE:
2062 break;
2063 }
2064 } else if (wp & WP_NOFILL) {
2065 ASSERT(level == 0);
2066
2067 /*
2068 * If we're writing preallocated blocks, we aren't actually
2069 * writing them so don't set any policy properties. These
2070 * blocks are currently only used by an external subsystem
2071 * outside of zfs (i.e. dump) and not written by the zio
2072 * pipeline.
2073 */
2074 compress = ZIO_COMPRESS_OFF;
2075 checksum = ZIO_CHECKSUM_OFF;
2076 } else {
2077 compress = zio_compress_select(os->os_spa, dn->dn_compress,
2078 compress);
2079 complevel = zio_complevel_select(os->os_spa, compress,
2080 complevel, complevel);
2081
2082 checksum = (dedup_checksum == ZIO_CHECKSUM_OFF) ?
2083 zio_checksum_select(dn->dn_checksum, checksum) :
2084 dedup_checksum;
2085
2086 /*
2087 * Determine dedup setting. If we are in dmu_sync(),
2088 * we won't actually dedup now because that's all
2089 * done in syncing context; but we do want to use the
2090 * dedup checksum. If the checksum is not strong
2091 * enough to ensure unique signatures, force
2092 * dedup_verify.
2093 */
2094 if (dedup_checksum != ZIO_CHECKSUM_OFF) {
2095 dedup = (wp & WP_DMU_SYNC) ? B_FALSE : B_TRUE;
2096 if (!(zio_checksum_table[checksum].ci_flags &
2097 ZCHECKSUM_FLAG_DEDUP))
2098 dedup_verify = B_TRUE;
2099 }
2100
2101 /*
2102 * Enable nopwrite if we have secure enough checksum
2103 * algorithm (see comment in zio_nop_write) and
2104 * compression is enabled. We don't enable nopwrite if
2105 * dedup is enabled as the two features are mutually
2106 * exclusive.
2107 */
2108 nopwrite = (!dedup && (zio_checksum_table[checksum].ci_flags &
2109 ZCHECKSUM_FLAG_NOPWRITE) &&
2110 compress != ZIO_COMPRESS_OFF && zfs_nopwrite_enabled);
2111 }
2112
2113 /*
2114 * All objects in an encrypted objset are protected from modification
2115 * via a MAC. Encrypted objects store their IV and salt in the last DVA
2116 * in the bp, so we cannot use all copies. Encrypted objects are also
2117 * not subject to nopwrite since writing the same data will still
2118 * result in a new ciphertext. Only encrypted blocks can be dedup'd
2119 * to avoid ambiguity in the dedup code since the DDT does not store
2120 * object types.
2121 */
2122 if (os->os_encrypted && (wp & WP_NOFILL) == 0) {
2123 encrypt = B_TRUE;
2124
2125 if (DMU_OT_IS_ENCRYPTED(type)) {
2126 copies = MIN(copies, SPA_DVAS_PER_BP - 1);
2127 nopwrite = B_FALSE;
2128 } else {
2129 dedup = B_FALSE;
2130 }
2131
2132 if (level <= 0 &&
2133 (type == DMU_OT_DNODE || type == DMU_OT_OBJSET)) {
2134 compress = ZIO_COMPRESS_EMPTY;
2135 }
2136 }
2137
2138 zp->zp_compress = compress;
2139 zp->zp_complevel = complevel;
2140 zp->zp_checksum = checksum;
2141 zp->zp_type = (wp & WP_SPILL) ? dn->dn_bonustype : type;
2142 zp->zp_level = level;
2143 zp->zp_copies = MIN(copies, spa_max_replication(os->os_spa));
2144 zp->zp_dedup = dedup;
2145 zp->zp_dedup_verify = dedup && dedup_verify;
2146 zp->zp_nopwrite = nopwrite;
2147 zp->zp_encrypt = encrypt;
2148 zp->zp_byteorder = ZFS_HOST_BYTEORDER;
2149 memset(zp->zp_salt, 0, ZIO_DATA_SALT_LEN);
2150 memset(zp->zp_iv, 0, ZIO_DATA_IV_LEN);
2151 memset(zp->zp_mac, 0, ZIO_DATA_MAC_LEN);
2152 zp->zp_zpl_smallblk = DMU_OT_IS_FILE(zp->zp_type) ?
2153 os->os_zpl_special_smallblock : 0;
2154
2155 ASSERT3U(zp->zp_compress, !=, ZIO_COMPRESS_INHERIT);
2156 }
2157
2158 /*
2159 * Reports the location of data and holes in an object. In order to
2160 * accurately report holes all dirty data must be synced to disk. This
2161 * causes extremely poor performance when seeking for holes in a dirty file.
2162 * As a compromise, only provide hole data when the dnode is clean. When
2163 * a dnode is dirty report the dnode as having no holes by returning EBUSY
2164 * which is always safe to do.
2165 */
2166 int
2167 dmu_offset_next(objset_t *os, uint64_t object, boolean_t hole, uint64_t *off)
2168 {
2169 dnode_t *dn;
2170 int restarted = 0, err;
2171
2172 restart:
2173 err = dnode_hold(os, object, FTAG, &dn);
2174 if (err)
2175 return (err);
2176
2177 rw_enter(&dn->dn_struct_rwlock, RW_READER);
2178
2179 if (dnode_is_dirty(dn)) {
2180 /*
2181 * If the zfs_dmu_offset_next_sync module option is enabled
2182 * then hole reporting has been requested. Dirty dnodes
2183 * must be synced to disk to accurately report holes.
2184 *
2185 * Provided a RL_READER rangelock spanning 0-UINT64_MAX is
2186 * held by the caller only a single restart will be required.
2187 * We tolerate callers which do not hold the rangelock by
2188 * returning EBUSY and not reporting holes after one restart.
2189 */
2190 if (zfs_dmu_offset_next_sync) {
2191 rw_exit(&dn->dn_struct_rwlock);
2192 dnode_rele(dn, FTAG);
2193
2194 if (restarted)
2195 return (SET_ERROR(EBUSY));
2196
2197 txg_wait_synced(dmu_objset_pool(os), 0);
2198 restarted = 1;
2199 goto restart;
2200 }
2201
2202 err = SET_ERROR(EBUSY);
2203 } else {
2204 err = dnode_next_offset(dn, DNODE_FIND_HAVELOCK |
2205 (hole ? DNODE_FIND_HOLE : 0), off, 1, 1, 0);
2206 }
2207
2208 rw_exit(&dn->dn_struct_rwlock);
2209 dnode_rele(dn, FTAG);
2210
2211 return (err);
2212 }
2213
2214 int
2215 dmu_read_l0_bps(objset_t *os, uint64_t object, uint64_t offset, uint64_t length,
2216 blkptr_t *bps, size_t *nbpsp)
2217 {
2218 dmu_buf_t **dbp, *dbuf;
2219 dmu_buf_impl_t *db;
2220 blkptr_t *bp;
2221 int error, numbufs;
2222
2223 error = dmu_buf_hold_array(os, object, offset, length, FALSE, FTAG,
2224 &numbufs, &dbp);
2225 if (error != 0) {
2226 if (error == ESRCH) {
2227 error = SET_ERROR(ENXIO);
2228 }
2229 return (error);
2230 }
2231
2232 ASSERT3U(numbufs, <=, *nbpsp);
2233
2234 for (int i = 0; i < numbufs; i++) {
2235 dbuf = dbp[i];
2236 db = (dmu_buf_impl_t *)dbuf;
2237
2238 mutex_enter(&db->db_mtx);
2239
2240 if (!list_is_empty(&db->db_dirty_records)) {
2241 dbuf_dirty_record_t *dr;
2242
2243 dr = list_head(&db->db_dirty_records);
2244 if (dr->dt.dl.dr_brtwrite) {
2245 /*
2246 * This is very special case where we clone a
2247 * block and in the same transaction group we
2248 * read its BP (most likely to clone the clone).
2249 */
2250 bp = &dr->dt.dl.dr_overridden_by;
2251 } else {
2252 /*
2253 * The block was modified in the same
2254 * transaction group.
2255 */
2256 mutex_exit(&db->db_mtx);
2257 error = SET_ERROR(EAGAIN);
2258 goto out;
2259 }
2260 } else {
2261 bp = db->db_blkptr;
2262 }
2263
2264 mutex_exit(&db->db_mtx);
2265
2266 if (bp == NULL) {
2267 /*
2268 * The block was created in this transaction group,
2269 * so it has no BP yet.
2270 */
2271 error = SET_ERROR(EAGAIN);
2272 goto out;
2273 }
2274 /*
2275 * Make sure we clone only data blocks.
2276 */
2277 if (BP_IS_METADATA(bp) && !BP_IS_HOLE(bp)) {
2278 error = SET_ERROR(EINVAL);
2279 goto out;
2280 }
2281
2282 /*
2283 * If the block was allocated in transaction group that is not
2284 * yet synced, we could clone it, but we couldn't write this
2285 * operation into ZIL, or it may be impossible to replay, since
2286 * the block may appear not yet allocated at that point.
2287 */
2288 if (BP_GET_BIRTH(bp) > spa_freeze_txg(os->os_spa)) {
2289 error = SET_ERROR(EINVAL);
2290 goto out;
2291 }
2292 if (BP_GET_BIRTH(bp) > spa_last_synced_txg(os->os_spa)) {
2293 error = SET_ERROR(EAGAIN);
2294 goto out;
2295 }
2296
2297 bps[i] = *bp;
2298 }
2299
2300 *nbpsp = numbufs;
2301 out:
2302 dmu_buf_rele_array(dbp, numbufs, FTAG);
2303
2304 return (error);
2305 }
2306
2307 int
2308 dmu_brt_clone(objset_t *os, uint64_t object, uint64_t offset, uint64_t length,
2309 dmu_tx_t *tx, const blkptr_t *bps, size_t nbps)
2310 {
2311 spa_t *spa;
2312 dmu_buf_t **dbp, *dbuf;
2313 dmu_buf_impl_t *db;
2314 struct dirty_leaf *dl;
2315 dbuf_dirty_record_t *dr;
2316 const blkptr_t *bp;
2317 int error = 0, i, numbufs;
2318
2319 spa = os->os_spa;
2320
2321 VERIFY0(dmu_buf_hold_array(os, object, offset, length, FALSE, FTAG,
2322 &numbufs, &dbp));
2323 ASSERT3U(nbps, ==, numbufs);
2324
2325 /*
2326 * Before we start cloning make sure that the dbufs sizes match new BPs
2327 * sizes. If they don't, that's a no-go, as we are not able to shrink
2328 * dbufs.
2329 */
2330 for (i = 0; i < numbufs; i++) {
2331 dbuf = dbp[i];
2332 db = (dmu_buf_impl_t *)dbuf;
2333 bp = &bps[i];
2334
2335 ASSERT0(db->db_level);
2336 ASSERT(db->db_blkid != DMU_BONUS_BLKID);
2337 ASSERT(db->db_blkid != DMU_SPILL_BLKID);
2338
2339 if (!BP_IS_HOLE(bp) && BP_GET_LSIZE(bp) != dbuf->db_size) {
2340 error = SET_ERROR(EXDEV);
2341 goto out;
2342 }
2343 }
2344
2345 for (i = 0; i < numbufs; i++) {
2346 dbuf = dbp[i];
2347 db = (dmu_buf_impl_t *)dbuf;
2348 bp = &bps[i];
2349
2350 ASSERT0(db->db_level);
2351 ASSERT(db->db_blkid != DMU_BONUS_BLKID);
2352 ASSERT(db->db_blkid != DMU_SPILL_BLKID);
2353 ASSERT(BP_IS_HOLE(bp) || dbuf->db_size == BP_GET_LSIZE(bp));
2354
2355 dmu_buf_will_clone(dbuf, tx);
2356
2357 mutex_enter(&db->db_mtx);
2358
2359 dr = list_head(&db->db_dirty_records);
2360 VERIFY(dr != NULL);
2361 ASSERT3U(dr->dr_txg, ==, tx->tx_txg);
2362 dl = &dr->dt.dl;
2363 dl->dr_overridden_by = *bp;
2364 dl->dr_brtwrite = B_TRUE;
2365 dl->dr_override_state = DR_OVERRIDDEN;
2366 if (BP_IS_HOLE(bp)) {
2367 BP_SET_LOGICAL_BIRTH(&dl->dr_overridden_by, 0);
2368 BP_SET_PHYSICAL_BIRTH(&dl->dr_overridden_by, 0);
2369 } else {
2370 BP_SET_LOGICAL_BIRTH(&dl->dr_overridden_by,
2371 dr->dr_txg);
2372 if (!BP_IS_EMBEDDED(bp)) {
2373 BP_SET_PHYSICAL_BIRTH(&dl->dr_overridden_by,
2374 BP_GET_BIRTH(bp));
2375 }
2376 }
2377
2378 mutex_exit(&db->db_mtx);
2379
2380 /*
2381 * When data in embedded into BP there is no need to create
2382 * BRT entry as there is no data block. Just copy the BP as
2383 * it contains the data.
2384 */
2385 if (!BP_IS_HOLE(bp) && !BP_IS_EMBEDDED(bp)) {
2386 brt_pending_add(spa, bp, tx);
2387 }
2388 }
2389 out:
2390 dmu_buf_rele_array(dbp, numbufs, FTAG);
2391
2392 return (error);
2393 }
2394
2395 void
2396 __dmu_object_info_from_dnode(dnode_t *dn, dmu_object_info_t *doi)
2397 {
2398 dnode_phys_t *dnp = dn->dn_phys;
2399
2400 doi->doi_data_block_size = dn->dn_datablksz;
2401 doi->doi_metadata_block_size = dn->dn_indblkshift ?
2402 1ULL << dn->dn_indblkshift : 0;
2403 doi->doi_type = dn->dn_type;
2404 doi->doi_bonus_type = dn->dn_bonustype;
2405 doi->doi_bonus_size = dn->dn_bonuslen;
2406 doi->doi_dnodesize = dn->dn_num_slots << DNODE_SHIFT;
2407 doi->doi_indirection = dn->dn_nlevels;
2408 doi->doi_checksum = dn->dn_checksum;
2409 doi->doi_compress = dn->dn_compress;
2410 doi->doi_nblkptr = dn->dn_nblkptr;
2411 doi->doi_physical_blocks_512 = (DN_USED_BYTES(dnp) + 256) >> 9;
2412 doi->doi_max_offset = (dn->dn_maxblkid + 1) * dn->dn_datablksz;
2413 doi->doi_fill_count = 0;
2414 for (int i = 0; i < dnp->dn_nblkptr; i++)
2415 doi->doi_fill_count += BP_GET_FILL(&dnp->dn_blkptr[i]);
2416 }
2417
2418 void
2419 dmu_object_info_from_dnode(dnode_t *dn, dmu_object_info_t *doi)
2420 {
2421 rw_enter(&dn->dn_struct_rwlock, RW_READER);
2422 mutex_enter(&dn->dn_mtx);
2423
2424 __dmu_object_info_from_dnode(dn, doi);
2425
2426 mutex_exit(&dn->dn_mtx);
2427 rw_exit(&dn->dn_struct_rwlock);
2428 }
2429
2430 /*
2431 * Get information on a DMU object.
2432 * If doi is NULL, just indicates whether the object exists.
2433 */
2434 int
2435 dmu_object_info(objset_t *os, uint64_t object, dmu_object_info_t *doi)
2436 {
2437 dnode_t *dn;
2438 int err = dnode_hold(os, object, FTAG, &dn);
2439
2440 if (err)
2441 return (err);
2442
2443 if (doi != NULL)
2444 dmu_object_info_from_dnode(dn, doi);
2445
2446 dnode_rele(dn, FTAG);
2447 return (0);
2448 }
2449
2450 /*
2451 * As above, but faster; can be used when you have a held dbuf in hand.
2452 */
2453 void
2454 dmu_object_info_from_db(dmu_buf_t *db_fake, dmu_object_info_t *doi)
2455 {
2456 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
2457
2458 DB_DNODE_ENTER(db);
2459 dmu_object_info_from_dnode(DB_DNODE(db), doi);
2460 DB_DNODE_EXIT(db);
2461 }
2462
2463 /*
2464 * Faster still when you only care about the size.
2465 */
2466 void
2467 dmu_object_size_from_db(dmu_buf_t *db_fake, uint32_t *blksize,
2468 u_longlong_t *nblk512)
2469 {
2470 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
2471 dnode_t *dn;
2472
2473 DB_DNODE_ENTER(db);
2474 dn = DB_DNODE(db);
2475
2476 *blksize = dn->dn_datablksz;
2477 /* add in number of slots used for the dnode itself */
2478 *nblk512 = ((DN_USED_BYTES(dn->dn_phys) + SPA_MINBLOCKSIZE/2) >>
2479 SPA_MINBLOCKSHIFT) + dn->dn_num_slots;
2480 DB_DNODE_EXIT(db);
2481 }
2482
2483 void
2484 dmu_object_dnsize_from_db(dmu_buf_t *db_fake, int *dnsize)
2485 {
2486 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
2487 dnode_t *dn;
2488
2489 DB_DNODE_ENTER(db);
2490 dn = DB_DNODE(db);
2491 *dnsize = dn->dn_num_slots << DNODE_SHIFT;
2492 DB_DNODE_EXIT(db);
2493 }
2494
2495 void
2496 byteswap_uint64_array(void *vbuf, size_t size)
2497 {
2498 uint64_t *buf = vbuf;
2499 size_t count = size >> 3;
2500 int i;
2501
2502 ASSERT((size & 7) == 0);
2503
2504 for (i = 0; i < count; i++)
2505 buf[i] = BSWAP_64(buf[i]);
2506 }
2507
2508 void
2509 byteswap_uint32_array(void *vbuf, size_t size)
2510 {
2511 uint32_t *buf = vbuf;
2512 size_t count = size >> 2;
2513 int i;
2514
2515 ASSERT((size & 3) == 0);
2516
2517 for (i = 0; i < count; i++)
2518 buf[i] = BSWAP_32(buf[i]);
2519 }
2520
2521 void
2522 byteswap_uint16_array(void *vbuf, size_t size)
2523 {
2524 uint16_t *buf = vbuf;
2525 size_t count = size >> 1;
2526 int i;
2527
2528 ASSERT((size & 1) == 0);
2529
2530 for (i = 0; i < count; i++)
2531 buf[i] = BSWAP_16(buf[i]);
2532 }
2533
2534 void
2535 byteswap_uint8_array(void *vbuf, size_t size)
2536 {
2537 (void) vbuf, (void) size;
2538 }
2539
2540 void
2541 dmu_init(void)
2542 {
2543 abd_init();
2544 zfs_dbgmsg_init();
2545 sa_cache_init();
2546 dmu_objset_init();
2547 dnode_init();
2548 zfetch_init();
2549 dmu_tx_init();
2550 l2arc_init();
2551 arc_init();
2552 dbuf_init();
2553 }
2554
2555 void
2556 dmu_fini(void)
2557 {
2558 arc_fini(); /* arc depends on l2arc, so arc must go first */
2559 l2arc_fini();
2560 dmu_tx_fini();
2561 zfetch_fini();
2562 dbuf_fini();
2563 dnode_fini();
2564 dmu_objset_fini();
2565 sa_cache_fini();
2566 zfs_dbgmsg_fini();
2567 abd_fini();
2568 }
2569
2570 EXPORT_SYMBOL(dmu_bonus_hold);
2571 EXPORT_SYMBOL(dmu_bonus_hold_by_dnode);
2572 EXPORT_SYMBOL(dmu_buf_hold_array_by_bonus);
2573 EXPORT_SYMBOL(dmu_buf_rele_array);
2574 EXPORT_SYMBOL(dmu_prefetch);
2575 EXPORT_SYMBOL(dmu_prefetch_by_dnode);
2576 EXPORT_SYMBOL(dmu_prefetch_dnode);
2577 EXPORT_SYMBOL(dmu_free_range);
2578 EXPORT_SYMBOL(dmu_free_long_range);
2579 EXPORT_SYMBOL(dmu_free_long_object);
2580 EXPORT_SYMBOL(dmu_read);
2581 EXPORT_SYMBOL(dmu_read_by_dnode);
2582 EXPORT_SYMBOL(dmu_write);
2583 EXPORT_SYMBOL(dmu_write_by_dnode);
2584 EXPORT_SYMBOL(dmu_prealloc);
2585 EXPORT_SYMBOL(dmu_object_info);
2586 EXPORT_SYMBOL(dmu_object_info_from_dnode);
2587 EXPORT_SYMBOL(dmu_object_info_from_db);
2588 EXPORT_SYMBOL(dmu_object_size_from_db);
2589 EXPORT_SYMBOL(dmu_object_dnsize_from_db);
2590 EXPORT_SYMBOL(dmu_object_set_nlevels);
2591 EXPORT_SYMBOL(dmu_object_set_blocksize);
2592 EXPORT_SYMBOL(dmu_object_set_maxblkid);
2593 EXPORT_SYMBOL(dmu_object_set_checksum);
2594 EXPORT_SYMBOL(dmu_object_set_compress);
2595 EXPORT_SYMBOL(dmu_offset_next);
2596 EXPORT_SYMBOL(dmu_write_policy);
2597 EXPORT_SYMBOL(dmu_sync);
2598 EXPORT_SYMBOL(dmu_request_arcbuf);
2599 EXPORT_SYMBOL(dmu_return_arcbuf);
2600 EXPORT_SYMBOL(dmu_assign_arcbuf_by_dnode);
2601 EXPORT_SYMBOL(dmu_assign_arcbuf_by_dbuf);
2602 EXPORT_SYMBOL(dmu_buf_hold);
2603 EXPORT_SYMBOL(dmu_ot);
2604
2605 ZFS_MODULE_PARAM(zfs, zfs_, nopwrite_enabled, INT, ZMOD_RW,
2606 "Enable NOP writes");
2607
2608 ZFS_MODULE_PARAM(zfs, zfs_, per_txg_dirty_frees_percent, UINT, ZMOD_RW,
2609 "Percentage of dirtied blocks from frees in one TXG");
2610
2611 ZFS_MODULE_PARAM(zfs, zfs_, dmu_offset_next_sync, INT, ZMOD_RW,
2612 "Enable forcing txg sync to find holes");
2613
2614 /* CSTYLED */
2615 ZFS_MODULE_PARAM(zfs, , dmu_prefetch_max, UINT, ZMOD_RW,
2616 "Limit one prefetch call to this size");
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