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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 int64_t level2 = level;
716 uint64_t start, end, start2, end2;
717
718 if (dmu_prefetch_max == 0 || len == 0) {
719 dmu_prefetch_dnode(os, object, pri);
720 return;
721 }
722
723 if (dnode_hold(os, object, FTAG, &dn) != 0)
724 return;
725
726 /*
727 * Depending on len we may do two prefetches: blocks [start, end) at
728 * level, and following blocks [start2, end2) at higher level2.
729 */
730 rw_enter(&dn->dn_struct_rwlock, RW_READER);
731 if (dn->dn_datablkshift != 0) {
732 /*
733 * The object has multiple blocks. Calculate the full range
734 * of blocks [start, end2) and then split it into two parts,
735 * so that the first [start, end) fits into dmu_prefetch_max.
736 */
737 start = dbuf_whichblock(dn, level, offset);
738 end2 = dbuf_whichblock(dn, level, offset + len - 1) + 1;
739 uint8_t ibs = dn->dn_indblkshift;
740 uint8_t bs = (level == 0) ? dn->dn_datablkshift : ibs;
741 uint_t limit = P2ROUNDUP(dmu_prefetch_max, 1 << bs) >> bs;
742 start2 = end = MIN(end2, start + limit);
743
744 /*
745 * Find level2 where [start2, end2) fits into dmu_prefetch_max.
746 */
747 uint8_t ibps = ibs - SPA_BLKPTRSHIFT;
748 limit = P2ROUNDUP(dmu_prefetch_max, 1 << ibs) >> ibs;
749 do {
750 level2++;
751 start2 = P2ROUNDUP(start2, 1 << ibps) >> ibps;
752 end2 = P2ROUNDUP(end2, 1 << ibps) >> ibps;
753 } while (end2 - start2 > limit);
754 } else {
755 /* There is only one block. Prefetch it or nothing. */
756 start = start2 = end2 = 0;
757 end = start + (level == 0 && offset < dn->dn_datablksz);
758 }
759
760 for (uint64_t i = start; i < end; i++)
761 dbuf_prefetch(dn, level, i, pri, 0);
762 for (uint64_t i = start2; i < end2; i++)
763 dbuf_prefetch(dn, level2, i, pri, 0);
764 rw_exit(&dn->dn_struct_rwlock);
765
766 dnode_rele(dn, FTAG);
767 }
768
769 /*
770 * Issue prefetch I/Os for the given object's dnode.
771 */
772 void
773 dmu_prefetch_dnode(objset_t *os, uint64_t object, zio_priority_t pri)
774 {
775 if (object == 0 || object >= DN_MAX_OBJECT)
776 return;
777
778 dnode_t *dn = DMU_META_DNODE(os);
779 rw_enter(&dn->dn_struct_rwlock, RW_READER);
780 uint64_t blkid = dbuf_whichblock(dn, 0, object * sizeof (dnode_phys_t));
781 dbuf_prefetch(dn, 0, blkid, pri, 0);
782 rw_exit(&dn->dn_struct_rwlock);
783 }
784
785 /*
786 * Get the next "chunk" of file data to free. We traverse the file from
787 * the end so that the file gets shorter over time (if we crashes in the
788 * middle, this will leave us in a better state). We find allocated file
789 * data by simply searching the allocated level 1 indirects.
790 *
791 * On input, *start should be the first offset that does not need to be
792 * freed (e.g. "offset + length"). On return, *start will be the first
793 * offset that should be freed and l1blks is set to the number of level 1
794 * indirect blocks found within the chunk.
795 */
796 static int
797 get_next_chunk(dnode_t *dn, uint64_t *start, uint64_t minimum, uint64_t *l1blks)
798 {
799 uint64_t blks;
800 uint64_t maxblks = DMU_MAX_ACCESS >> (dn->dn_indblkshift + 1);
801 /* bytes of data covered by a level-1 indirect block */
802 uint64_t iblkrange = (uint64_t)dn->dn_datablksz *
803 EPB(dn->dn_indblkshift, SPA_BLKPTRSHIFT);
804
805 ASSERT3U(minimum, <=, *start);
806
807 /*
808 * Check if we can free the entire range assuming that all of the
809 * L1 blocks in this range have data. If we can, we use this
810 * worst case value as an estimate so we can avoid having to look
811 * at the object's actual data.
812 */
813 uint64_t total_l1blks =
814 (roundup(*start, iblkrange) - (minimum / iblkrange * iblkrange)) /
815 iblkrange;
816 if (total_l1blks <= maxblks) {
817 *l1blks = total_l1blks;
818 *start = minimum;
819 return (0);
820 }
821 ASSERT(ISP2(iblkrange));
822
823 for (blks = 0; *start > minimum && blks < maxblks; blks++) {
824 int err;
825
826 /*
827 * dnode_next_offset(BACKWARDS) will find an allocated L1
828 * indirect block at or before the input offset. We must
829 * decrement *start so that it is at the end of the region
830 * to search.
831 */
832 (*start)--;
833
834 err = dnode_next_offset(dn,
835 DNODE_FIND_BACKWARDS, start, 2, 1, 0);
836
837 /* if there are no indirect blocks before start, we are done */
838 if (err == ESRCH) {
839 *start = minimum;
840 break;
841 } else if (err != 0) {
842 *l1blks = blks;
843 return (err);
844 }
845
846 /* set start to the beginning of this L1 indirect */
847 *start = P2ALIGN(*start, iblkrange);
848 }
849 if (*start < minimum)
850 *start = minimum;
851 *l1blks = blks;
852
853 return (0);
854 }
855
856 /*
857 * If this objset is of type OST_ZFS return true if vfs's unmounted flag is set,
858 * otherwise return false.
859 * Used below in dmu_free_long_range_impl() to enable abort when unmounting
860 */
861 static boolean_t
862 dmu_objset_zfs_unmounting(objset_t *os)
863 {
864 #ifdef _KERNEL
865 if (dmu_objset_type(os) == DMU_OST_ZFS)
866 return (zfs_get_vfs_flag_unmounted(os));
867 #else
868 (void) os;
869 #endif
870 return (B_FALSE);
871 }
872
873 static int
874 dmu_free_long_range_impl(objset_t *os, dnode_t *dn, uint64_t offset,
875 uint64_t length)
876 {
877 uint64_t object_size;
878 int err;
879 uint64_t dirty_frees_threshold;
880 dsl_pool_t *dp = dmu_objset_pool(os);
881
882 if (dn == NULL)
883 return (SET_ERROR(EINVAL));
884
885 object_size = (dn->dn_maxblkid + 1) * dn->dn_datablksz;
886 if (offset >= object_size)
887 return (0);
888
889 if (zfs_per_txg_dirty_frees_percent <= 100)
890 dirty_frees_threshold =
891 zfs_per_txg_dirty_frees_percent * zfs_dirty_data_max / 100;
892 else
893 dirty_frees_threshold = zfs_dirty_data_max / 20;
894
895 if (length == DMU_OBJECT_END || offset + length > object_size)
896 length = object_size - offset;
897
898 while (length != 0) {
899 uint64_t chunk_end, chunk_begin, chunk_len;
900 uint64_t l1blks;
901 dmu_tx_t *tx;
902
903 if (dmu_objset_zfs_unmounting(dn->dn_objset))
904 return (SET_ERROR(EINTR));
905
906 chunk_end = chunk_begin = offset + length;
907
908 /* move chunk_begin backwards to the beginning of this chunk */
909 err = get_next_chunk(dn, &chunk_begin, offset, &l1blks);
910 if (err)
911 return (err);
912 ASSERT3U(chunk_begin, >=, offset);
913 ASSERT3U(chunk_begin, <=, chunk_end);
914
915 chunk_len = chunk_end - chunk_begin;
916
917 tx = dmu_tx_create(os);
918 dmu_tx_hold_free(tx, dn->dn_object, chunk_begin, chunk_len);
919
920 /*
921 * Mark this transaction as typically resulting in a net
922 * reduction in space used.
923 */
924 dmu_tx_mark_netfree(tx);
925 err = dmu_tx_assign(tx, TXG_WAIT);
926 if (err) {
927 dmu_tx_abort(tx);
928 return (err);
929 }
930
931 uint64_t txg = dmu_tx_get_txg(tx);
932
933 mutex_enter(&dp->dp_lock);
934 uint64_t long_free_dirty =
935 dp->dp_long_free_dirty_pertxg[txg & TXG_MASK];
936 mutex_exit(&dp->dp_lock);
937
938 /*
939 * To avoid filling up a TXG with just frees, wait for
940 * the next TXG to open before freeing more chunks if
941 * we have reached the threshold of frees.
942 */
943 if (dirty_frees_threshold != 0 &&
944 long_free_dirty >= dirty_frees_threshold) {
945 DMU_TX_STAT_BUMP(dmu_tx_dirty_frees_delay);
946 dmu_tx_commit(tx);
947 txg_wait_open(dp, 0, B_TRUE);
948 continue;
949 }
950
951 /*
952 * In order to prevent unnecessary write throttling, for each
953 * TXG, we track the cumulative size of L1 blocks being dirtied
954 * in dnode_free_range() below. We compare this number to a
955 * tunable threshold, past which we prevent new L1 dirty freeing
956 * blocks from being added into the open TXG. See
957 * dmu_free_long_range_impl() for details. The threshold
958 * prevents write throttle activation due to dirty freeing L1
959 * blocks taking up a large percentage of zfs_dirty_data_max.
960 */
961 mutex_enter(&dp->dp_lock);
962 dp->dp_long_free_dirty_pertxg[txg & TXG_MASK] +=
963 l1blks << dn->dn_indblkshift;
964 mutex_exit(&dp->dp_lock);
965 DTRACE_PROBE3(free__long__range,
966 uint64_t, long_free_dirty, uint64_t, chunk_len,
967 uint64_t, txg);
968 dnode_free_range(dn, chunk_begin, chunk_len, tx);
969
970 dmu_tx_commit(tx);
971
972 length -= chunk_len;
973 }
974 return (0);
975 }
976
977 int
978 dmu_free_long_range(objset_t *os, uint64_t object,
979 uint64_t offset, uint64_t length)
980 {
981 dnode_t *dn;
982 int err;
983
984 err = dnode_hold(os, object, FTAG, &dn);
985 if (err != 0)
986 return (err);
987 err = dmu_free_long_range_impl(os, dn, offset, length);
988
989 /*
990 * It is important to zero out the maxblkid when freeing the entire
991 * file, so that (a) subsequent calls to dmu_free_long_range_impl()
992 * will take the fast path, and (b) dnode_reallocate() can verify
993 * that the entire file has been freed.
994 */
995 if (err == 0 && offset == 0 && length == DMU_OBJECT_END)
996 dn->dn_maxblkid = 0;
997
998 dnode_rele(dn, FTAG);
999 return (err);
1000 }
1001
1002 int
1003 dmu_free_long_object(objset_t *os, uint64_t object)
1004 {
1005 dmu_tx_t *tx;
1006 int err;
1007
1008 err = dmu_free_long_range(os, object, 0, DMU_OBJECT_END);
1009 if (err != 0)
1010 return (err);
1011
1012 tx = dmu_tx_create(os);
1013 dmu_tx_hold_bonus(tx, object);
1014 dmu_tx_hold_free(tx, object, 0, DMU_OBJECT_END);
1015 dmu_tx_mark_netfree(tx);
1016 err = dmu_tx_assign(tx, TXG_WAIT);
1017 if (err == 0) {
1018 err = dmu_object_free(os, object, tx);
1019 dmu_tx_commit(tx);
1020 } else {
1021 dmu_tx_abort(tx);
1022 }
1023
1024 return (err);
1025 }
1026
1027 int
1028 dmu_free_range(objset_t *os, uint64_t object, uint64_t offset,
1029 uint64_t size, dmu_tx_t *tx)
1030 {
1031 dnode_t *dn;
1032 int err = dnode_hold(os, object, FTAG, &dn);
1033 if (err)
1034 return (err);
1035 ASSERT(offset < UINT64_MAX);
1036 ASSERT(size == DMU_OBJECT_END || size <= UINT64_MAX - offset);
1037 dnode_free_range(dn, offset, size, tx);
1038 dnode_rele(dn, FTAG);
1039 return (0);
1040 }
1041
1042 static int
1043 dmu_read_impl(dnode_t *dn, uint64_t offset, uint64_t size,
1044 void *buf, uint32_t flags)
1045 {
1046 dmu_buf_t **dbp;
1047 int numbufs, err = 0;
1048
1049 /*
1050 * Deal with odd block sizes, where there can't be data past the first
1051 * block. If we ever do the tail block optimization, we will need to
1052 * handle that here as well.
1053 */
1054 if (dn->dn_maxblkid == 0) {
1055 uint64_t newsz = offset > dn->dn_datablksz ? 0 :
1056 MIN(size, dn->dn_datablksz - offset);
1057 memset((char *)buf + newsz, 0, size - newsz);
1058 size = newsz;
1059 }
1060
1061 while (size > 0) {
1062 uint64_t mylen = MIN(size, DMU_MAX_ACCESS / 2);
1063 int i;
1064
1065 /*
1066 * NB: we could do this block-at-a-time, but it's nice
1067 * to be reading in parallel.
1068 */
1069 err = dmu_buf_hold_array_by_dnode(dn, offset, mylen,
1070 TRUE, FTAG, &numbufs, &dbp, flags);
1071 if (err)
1072 break;
1073
1074 for (i = 0; i < numbufs; i++) {
1075 uint64_t tocpy;
1076 int64_t bufoff;
1077 dmu_buf_t *db = dbp[i];
1078
1079 ASSERT(size > 0);
1080
1081 bufoff = offset - db->db_offset;
1082 tocpy = MIN(db->db_size - bufoff, size);
1083
1084 (void) memcpy(buf, (char *)db->db_data + bufoff, tocpy);
1085
1086 offset += tocpy;
1087 size -= tocpy;
1088 buf = (char *)buf + tocpy;
1089 }
1090 dmu_buf_rele_array(dbp, numbufs, FTAG);
1091 }
1092 return (err);
1093 }
1094
1095 int
1096 dmu_read(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
1097 void *buf, uint32_t flags)
1098 {
1099 dnode_t *dn;
1100 int err;
1101
1102 err = dnode_hold(os, object, FTAG, &dn);
1103 if (err != 0)
1104 return (err);
1105
1106 err = dmu_read_impl(dn, offset, size, buf, flags);
1107 dnode_rele(dn, FTAG);
1108 return (err);
1109 }
1110
1111 int
1112 dmu_read_by_dnode(dnode_t *dn, uint64_t offset, uint64_t size, void *buf,
1113 uint32_t flags)
1114 {
1115 return (dmu_read_impl(dn, offset, size, buf, flags));
1116 }
1117
1118 static void
1119 dmu_write_impl(dmu_buf_t **dbp, int numbufs, uint64_t offset, uint64_t size,
1120 const void *buf, dmu_tx_t *tx)
1121 {
1122 int i;
1123
1124 for (i = 0; i < numbufs; i++) {
1125 uint64_t tocpy;
1126 int64_t bufoff;
1127 dmu_buf_t *db = dbp[i];
1128
1129 ASSERT(size > 0);
1130
1131 bufoff = offset - db->db_offset;
1132 tocpy = MIN(db->db_size - bufoff, size);
1133
1134 ASSERT(i == 0 || i == numbufs-1 || tocpy == db->db_size);
1135
1136 if (tocpy == db->db_size)
1137 dmu_buf_will_fill(db, tx);
1138 else
1139 dmu_buf_will_dirty(db, tx);
1140
1141 (void) memcpy((char *)db->db_data + bufoff, buf, tocpy);
1142
1143 if (tocpy == db->db_size)
1144 dmu_buf_fill_done(db, tx);
1145
1146 offset += tocpy;
1147 size -= tocpy;
1148 buf = (char *)buf + tocpy;
1149 }
1150 }
1151
1152 void
1153 dmu_write(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
1154 const void *buf, dmu_tx_t *tx)
1155 {
1156 dmu_buf_t **dbp;
1157 int numbufs;
1158
1159 if (size == 0)
1160 return;
1161
1162 VERIFY0(dmu_buf_hold_array(os, object, offset, size,
1163 FALSE, FTAG, &numbufs, &dbp));
1164 dmu_write_impl(dbp, numbufs, offset, size, buf, tx);
1165 dmu_buf_rele_array(dbp, numbufs, FTAG);
1166 }
1167
1168 /*
1169 * Note: Lustre is an external consumer of this interface.
1170 */
1171 void
1172 dmu_write_by_dnode(dnode_t *dn, uint64_t offset, uint64_t size,
1173 const void *buf, dmu_tx_t *tx)
1174 {
1175 dmu_buf_t **dbp;
1176 int numbufs;
1177
1178 if (size == 0)
1179 return;
1180
1181 VERIFY0(dmu_buf_hold_array_by_dnode(dn, offset, size,
1182 FALSE, FTAG, &numbufs, &dbp, DMU_READ_PREFETCH));
1183 dmu_write_impl(dbp, numbufs, offset, size, buf, tx);
1184 dmu_buf_rele_array(dbp, numbufs, FTAG);
1185 }
1186
1187 void
1188 dmu_prealloc(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
1189 dmu_tx_t *tx)
1190 {
1191 dmu_buf_t **dbp;
1192 int numbufs, i;
1193
1194 if (size == 0)
1195 return;
1196
1197 VERIFY(0 == dmu_buf_hold_array(os, object, offset, size,
1198 FALSE, FTAG, &numbufs, &dbp));
1199
1200 for (i = 0; i < numbufs; i++) {
1201 dmu_buf_t *db = dbp[i];
1202
1203 dmu_buf_will_not_fill(db, tx);
1204 }
1205 dmu_buf_rele_array(dbp, numbufs, FTAG);
1206 }
1207
1208 void
1209 dmu_write_embedded(objset_t *os, uint64_t object, uint64_t offset,
1210 void *data, uint8_t etype, uint8_t comp, int uncompressed_size,
1211 int compressed_size, int byteorder, dmu_tx_t *tx)
1212 {
1213 dmu_buf_t *db;
1214
1215 ASSERT3U(etype, <, NUM_BP_EMBEDDED_TYPES);
1216 ASSERT3U(comp, <, ZIO_COMPRESS_FUNCTIONS);
1217 VERIFY0(dmu_buf_hold_noread(os, object, offset,
1218 FTAG, &db));
1219
1220 dmu_buf_write_embedded(db,
1221 data, (bp_embedded_type_t)etype, (enum zio_compress)comp,
1222 uncompressed_size, compressed_size, byteorder, tx);
1223
1224 dmu_buf_rele(db, FTAG);
1225 }
1226
1227 void
1228 dmu_redact(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
1229 dmu_tx_t *tx)
1230 {
1231 int numbufs, i;
1232 dmu_buf_t **dbp;
1233
1234 VERIFY0(dmu_buf_hold_array(os, object, offset, size, FALSE, FTAG,
1235 &numbufs, &dbp));
1236 for (i = 0; i < numbufs; i++)
1237 dmu_buf_redact(dbp[i], tx);
1238 dmu_buf_rele_array(dbp, numbufs, FTAG);
1239 }
1240
1241 #ifdef _KERNEL
1242 int
1243 dmu_read_uio_dnode(dnode_t *dn, zfs_uio_t *uio, uint64_t size)
1244 {
1245 dmu_buf_t **dbp;
1246 int numbufs, i, err;
1247
1248 /*
1249 * NB: we could do this block-at-a-time, but it's nice
1250 * to be reading in parallel.
1251 */
1252 err = dmu_buf_hold_array_by_dnode(dn, zfs_uio_offset(uio), size,
1253 TRUE, FTAG, &numbufs, &dbp, 0);
1254 if (err)
1255 return (err);
1256
1257 for (i = 0; i < numbufs; i++) {
1258 uint64_t tocpy;
1259 int64_t bufoff;
1260 dmu_buf_t *db = dbp[i];
1261
1262 ASSERT(size > 0);
1263
1264 bufoff = zfs_uio_offset(uio) - db->db_offset;
1265 tocpy = MIN(db->db_size - bufoff, size);
1266
1267 err = zfs_uio_fault_move((char *)db->db_data + bufoff, tocpy,
1268 UIO_READ, uio);
1269
1270 if (err)
1271 break;
1272
1273 size -= tocpy;
1274 }
1275 dmu_buf_rele_array(dbp, numbufs, FTAG);
1276
1277 return (err);
1278 }
1279
1280 /*
1281 * Read 'size' bytes into the uio buffer.
1282 * From object zdb->db_object.
1283 * Starting at zfs_uio_offset(uio).
1284 *
1285 * If the caller already has a dbuf in the target object
1286 * (e.g. its bonus buffer), this routine is faster than dmu_read_uio(),
1287 * because we don't have to find the dnode_t for the object.
1288 */
1289 int
1290 dmu_read_uio_dbuf(dmu_buf_t *zdb, zfs_uio_t *uio, uint64_t size)
1291 {
1292 dmu_buf_impl_t *db = (dmu_buf_impl_t *)zdb;
1293 dnode_t *dn;
1294 int err;
1295
1296 if (size == 0)
1297 return (0);
1298
1299 DB_DNODE_ENTER(db);
1300 dn = DB_DNODE(db);
1301 err = dmu_read_uio_dnode(dn, uio, size);
1302 DB_DNODE_EXIT(db);
1303
1304 return (err);
1305 }
1306
1307 /*
1308 * Read 'size' bytes into the uio buffer.
1309 * From the specified object
1310 * Starting at offset zfs_uio_offset(uio).
1311 */
1312 int
1313 dmu_read_uio(objset_t *os, uint64_t object, zfs_uio_t *uio, uint64_t size)
1314 {
1315 dnode_t *dn;
1316 int err;
1317
1318 if (size == 0)
1319 return (0);
1320
1321 err = dnode_hold(os, object, FTAG, &dn);
1322 if (err)
1323 return (err);
1324
1325 err = dmu_read_uio_dnode(dn, uio, size);
1326
1327 dnode_rele(dn, FTAG);
1328
1329 return (err);
1330 }
1331
1332 int
1333 dmu_write_uio_dnode(dnode_t *dn, zfs_uio_t *uio, uint64_t size, dmu_tx_t *tx)
1334 {
1335 dmu_buf_t **dbp;
1336 int numbufs;
1337 int err = 0;
1338 int i;
1339
1340 err = dmu_buf_hold_array_by_dnode(dn, zfs_uio_offset(uio), size,
1341 FALSE, FTAG, &numbufs, &dbp, DMU_READ_PREFETCH);
1342 if (err)
1343 return (err);
1344
1345 for (i = 0; i < numbufs; i++) {
1346 uint64_t tocpy;
1347 int64_t bufoff;
1348 dmu_buf_t *db = dbp[i];
1349
1350 ASSERT(size > 0);
1351
1352 bufoff = zfs_uio_offset(uio) - db->db_offset;
1353 tocpy = MIN(db->db_size - bufoff, size);
1354
1355 ASSERT(i == 0 || i == numbufs-1 || tocpy == db->db_size);
1356
1357 if (tocpy == db->db_size)
1358 dmu_buf_will_fill(db, tx);
1359 else
1360 dmu_buf_will_dirty(db, tx);
1361
1362 /*
1363 * XXX zfs_uiomove could block forever (eg.nfs-backed
1364 * pages). There needs to be a uiolockdown() function
1365 * to lock the pages in memory, so that zfs_uiomove won't
1366 * block.
1367 */
1368 err = zfs_uio_fault_move((char *)db->db_data + bufoff,
1369 tocpy, UIO_WRITE, uio);
1370
1371 if (tocpy == db->db_size)
1372 dmu_buf_fill_done(db, tx);
1373
1374 if (err)
1375 break;
1376
1377 size -= tocpy;
1378 }
1379
1380 dmu_buf_rele_array(dbp, numbufs, FTAG);
1381 return (err);
1382 }
1383
1384 /*
1385 * Write 'size' bytes from the uio buffer.
1386 * To object zdb->db_object.
1387 * Starting at offset zfs_uio_offset(uio).
1388 *
1389 * If the caller already has a dbuf in the target object
1390 * (e.g. its bonus buffer), this routine is faster than dmu_write_uio(),
1391 * because we don't have to find the dnode_t for the object.
1392 */
1393 int
1394 dmu_write_uio_dbuf(dmu_buf_t *zdb, zfs_uio_t *uio, uint64_t size,
1395 dmu_tx_t *tx)
1396 {
1397 dmu_buf_impl_t *db = (dmu_buf_impl_t *)zdb;
1398 dnode_t *dn;
1399 int err;
1400
1401 if (size == 0)
1402 return (0);
1403
1404 DB_DNODE_ENTER(db);
1405 dn = DB_DNODE(db);
1406 err = dmu_write_uio_dnode(dn, uio, size, tx);
1407 DB_DNODE_EXIT(db);
1408
1409 return (err);
1410 }
1411
1412 /*
1413 * Write 'size' bytes from the uio buffer.
1414 * To the specified object.
1415 * Starting at offset zfs_uio_offset(uio).
1416 */
1417 int
1418 dmu_write_uio(objset_t *os, uint64_t object, zfs_uio_t *uio, uint64_t size,
1419 dmu_tx_t *tx)
1420 {
1421 dnode_t *dn;
1422 int err;
1423
1424 if (size == 0)
1425 return (0);
1426
1427 err = dnode_hold(os, object, FTAG, &dn);
1428 if (err)
1429 return (err);
1430
1431 err = dmu_write_uio_dnode(dn, uio, size, tx);
1432
1433 dnode_rele(dn, FTAG);
1434
1435 return (err);
1436 }
1437 #endif /* _KERNEL */
1438
1439 /*
1440 * Allocate a loaned anonymous arc buffer.
1441 */
1442 arc_buf_t *
1443 dmu_request_arcbuf(dmu_buf_t *handle, int size)
1444 {
1445 dmu_buf_impl_t *db = (dmu_buf_impl_t *)handle;
1446
1447 return (arc_loan_buf(db->db_objset->os_spa, B_FALSE, size));
1448 }
1449
1450 /*
1451 * Free a loaned arc buffer.
1452 */
1453 void
1454 dmu_return_arcbuf(arc_buf_t *buf)
1455 {
1456 arc_return_buf(buf, FTAG);
1457 arc_buf_destroy(buf, FTAG);
1458 }
1459
1460 /*
1461 * A "lightweight" write is faster than a regular write (e.g.
1462 * dmu_write_by_dnode() or dmu_assign_arcbuf_by_dnode()), because it avoids the
1463 * CPU cost of creating a dmu_buf_impl_t and arc_buf_[hdr_]_t. However, the
1464 * data can not be read or overwritten until the transaction's txg has been
1465 * synced. This makes it appropriate for workloads that are known to be
1466 * (temporarily) write-only, like "zfs receive".
1467 *
1468 * A single block is written, starting at the specified offset in bytes. If
1469 * the call is successful, it returns 0 and the provided abd has been
1470 * consumed (the caller should not free it).
1471 */
1472 int
1473 dmu_lightweight_write_by_dnode(dnode_t *dn, uint64_t offset, abd_t *abd,
1474 const zio_prop_t *zp, zio_flag_t flags, dmu_tx_t *tx)
1475 {
1476 dbuf_dirty_record_t *dr =
1477 dbuf_dirty_lightweight(dn, dbuf_whichblock(dn, 0, offset), tx);
1478 if (dr == NULL)
1479 return (SET_ERROR(EIO));
1480 dr->dt.dll.dr_abd = abd;
1481 dr->dt.dll.dr_props = *zp;
1482 dr->dt.dll.dr_flags = flags;
1483 return (0);
1484 }
1485
1486 /*
1487 * When possible directly assign passed loaned arc buffer to a dbuf.
1488 * If this is not possible copy the contents of passed arc buf via
1489 * dmu_write().
1490 */
1491 int
1492 dmu_assign_arcbuf_by_dnode(dnode_t *dn, uint64_t offset, arc_buf_t *buf,
1493 dmu_tx_t *tx)
1494 {
1495 dmu_buf_impl_t *db;
1496 objset_t *os = dn->dn_objset;
1497 uint64_t object = dn->dn_object;
1498 uint32_t blksz = (uint32_t)arc_buf_lsize(buf);
1499 uint64_t blkid;
1500
1501 rw_enter(&dn->dn_struct_rwlock, RW_READER);
1502 blkid = dbuf_whichblock(dn, 0, offset);
1503 db = dbuf_hold(dn, blkid, FTAG);
1504 if (db == NULL)
1505 return (SET_ERROR(EIO));
1506 rw_exit(&dn->dn_struct_rwlock);
1507
1508 /*
1509 * We can only assign if the offset is aligned and the arc buf is the
1510 * same size as the dbuf.
1511 */
1512 if (offset == db->db.db_offset && blksz == db->db.db_size) {
1513 zfs_racct_write(blksz, 1);
1514 dbuf_assign_arcbuf(db, buf, tx);
1515 dbuf_rele(db, FTAG);
1516 } else {
1517 /* compressed bufs must always be assignable to their dbuf */
1518 ASSERT3U(arc_get_compression(buf), ==, ZIO_COMPRESS_OFF);
1519 ASSERT(!(buf->b_flags & ARC_BUF_FLAG_COMPRESSED));
1520
1521 dbuf_rele(db, FTAG);
1522 dmu_write(os, object, offset, blksz, buf->b_data, tx);
1523 dmu_return_arcbuf(buf);
1524 }
1525
1526 return (0);
1527 }
1528
1529 int
1530 dmu_assign_arcbuf_by_dbuf(dmu_buf_t *handle, uint64_t offset, arc_buf_t *buf,
1531 dmu_tx_t *tx)
1532 {
1533 int err;
1534 dmu_buf_impl_t *dbuf = (dmu_buf_impl_t *)handle;
1535
1536 DB_DNODE_ENTER(dbuf);
1537 err = dmu_assign_arcbuf_by_dnode(DB_DNODE(dbuf), offset, buf, tx);
1538 DB_DNODE_EXIT(dbuf);
1539
1540 return (err);
1541 }
1542
1543 typedef struct {
1544 dbuf_dirty_record_t *dsa_dr;
1545 dmu_sync_cb_t *dsa_done;
1546 zgd_t *dsa_zgd;
1547 dmu_tx_t *dsa_tx;
1548 } dmu_sync_arg_t;
1549
1550 static void
1551 dmu_sync_ready(zio_t *zio, arc_buf_t *buf, void *varg)
1552 {
1553 (void) buf;
1554 dmu_sync_arg_t *dsa = varg;
1555 dmu_buf_t *db = dsa->dsa_zgd->zgd_db;
1556 blkptr_t *bp = zio->io_bp;
1557
1558 if (zio->io_error == 0) {
1559 if (BP_IS_HOLE(bp)) {
1560 /*
1561 * A block of zeros may compress to a hole, but the
1562 * block size still needs to be known for replay.
1563 */
1564 BP_SET_LSIZE(bp, db->db_size);
1565 } else if (!BP_IS_EMBEDDED(bp)) {
1566 ASSERT(BP_GET_LEVEL(bp) == 0);
1567 BP_SET_FILL(bp, 1);
1568 }
1569 }
1570 }
1571
1572 static void
1573 dmu_sync_late_arrival_ready(zio_t *zio)
1574 {
1575 dmu_sync_ready(zio, NULL, zio->io_private);
1576 }
1577
1578 static void
1579 dmu_sync_done(zio_t *zio, arc_buf_t *buf, void *varg)
1580 {
1581 (void) buf;
1582 dmu_sync_arg_t *dsa = varg;
1583 dbuf_dirty_record_t *dr = dsa->dsa_dr;
1584 dmu_buf_impl_t *db = dr->dr_dbuf;
1585 zgd_t *zgd = dsa->dsa_zgd;
1586
1587 /*
1588 * Record the vdev(s) backing this blkptr so they can be flushed after
1589 * the writes for the lwb have completed.
1590 */
1591 if (zio->io_error == 0) {
1592 zil_lwb_add_block(zgd->zgd_lwb, zgd->zgd_bp);
1593 }
1594
1595 mutex_enter(&db->db_mtx);
1596 ASSERT(dr->dt.dl.dr_override_state == DR_IN_DMU_SYNC);
1597 if (zio->io_error == 0) {
1598 dr->dt.dl.dr_nopwrite = !!(zio->io_flags & ZIO_FLAG_NOPWRITE);
1599 if (dr->dt.dl.dr_nopwrite) {
1600 blkptr_t *bp = zio->io_bp;
1601 blkptr_t *bp_orig = &zio->io_bp_orig;
1602 uint8_t chksum = BP_GET_CHECKSUM(bp_orig);
1603
1604 ASSERT(BP_EQUAL(bp, bp_orig));
1605 VERIFY(BP_EQUAL(bp, db->db_blkptr));
1606 ASSERT(zio->io_prop.zp_compress != ZIO_COMPRESS_OFF);
1607 VERIFY(zio_checksum_table[chksum].ci_flags &
1608 ZCHECKSUM_FLAG_NOPWRITE);
1609 }
1610 dr->dt.dl.dr_overridden_by = *zio->io_bp;
1611 dr->dt.dl.dr_override_state = DR_OVERRIDDEN;
1612 dr->dt.dl.dr_copies = zio->io_prop.zp_copies;
1613
1614 /*
1615 * Old style holes are filled with all zeros, whereas
1616 * new-style holes maintain their lsize, type, level,
1617 * and birth time (see zio_write_compress). While we
1618 * need to reset the BP_SET_LSIZE() call that happened
1619 * in dmu_sync_ready for old style holes, we do *not*
1620 * want to wipe out the information contained in new
1621 * style holes. Thus, only zero out the block pointer if
1622 * it's an old style hole.
1623 */
1624 if (BP_IS_HOLE(&dr->dt.dl.dr_overridden_by) &&
1625 dr->dt.dl.dr_overridden_by.blk_birth == 0)
1626 BP_ZERO(&dr->dt.dl.dr_overridden_by);
1627 } else {
1628 dr->dt.dl.dr_override_state = DR_NOT_OVERRIDDEN;
1629 }
1630 cv_broadcast(&db->db_changed);
1631 mutex_exit(&db->db_mtx);
1632
1633 dsa->dsa_done(dsa->dsa_zgd, zio->io_error);
1634
1635 kmem_free(dsa, sizeof (*dsa));
1636 }
1637
1638 static void
1639 dmu_sync_late_arrival_done(zio_t *zio)
1640 {
1641 blkptr_t *bp = zio->io_bp;
1642 dmu_sync_arg_t *dsa = zio->io_private;
1643 zgd_t *zgd = dsa->dsa_zgd;
1644
1645 if (zio->io_error == 0) {
1646 /*
1647 * Record the vdev(s) backing this blkptr so they can be
1648 * flushed after the writes for the lwb have completed.
1649 */
1650 zil_lwb_add_block(zgd->zgd_lwb, zgd->zgd_bp);
1651
1652 if (!BP_IS_HOLE(bp)) {
1653 blkptr_t *bp_orig __maybe_unused = &zio->io_bp_orig;
1654 ASSERT(!(zio->io_flags & ZIO_FLAG_NOPWRITE));
1655 ASSERT(BP_IS_HOLE(bp_orig) || !BP_EQUAL(bp, bp_orig));
1656 ASSERT(zio->io_bp->blk_birth == zio->io_txg);
1657 ASSERT(zio->io_txg > spa_syncing_txg(zio->io_spa));
1658 zio_free(zio->io_spa, zio->io_txg, zio->io_bp);
1659 }
1660 }
1661
1662 dmu_tx_commit(dsa->dsa_tx);
1663
1664 dsa->dsa_done(dsa->dsa_zgd, zio->io_error);
1665
1666 abd_free(zio->io_abd);
1667 kmem_free(dsa, sizeof (*dsa));
1668 }
1669
1670 static int
1671 dmu_sync_late_arrival(zio_t *pio, objset_t *os, dmu_sync_cb_t *done, zgd_t *zgd,
1672 zio_prop_t *zp, zbookmark_phys_t *zb)
1673 {
1674 dmu_sync_arg_t *dsa;
1675 dmu_tx_t *tx;
1676 int error;
1677
1678 error = dbuf_read((dmu_buf_impl_t *)zgd->zgd_db, NULL,
1679 DB_RF_CANFAIL | DB_RF_NOPREFETCH);
1680 if (error != 0)
1681 return (error);
1682
1683 tx = dmu_tx_create(os);
1684 dmu_tx_hold_space(tx, zgd->zgd_db->db_size);
1685 /*
1686 * This transaction does not produce any dirty data or log blocks, so
1687 * it should not be throttled. All other cases wait for TXG sync, by
1688 * which time the log block we are writing will be obsolete, so we can
1689 * skip waiting and just return error here instead.
1690 */
1691 if (dmu_tx_assign(tx, TXG_NOWAIT | TXG_NOTHROTTLE) != 0) {
1692 dmu_tx_abort(tx);
1693 /* Make zl_get_data do txg_waited_synced() */
1694 return (SET_ERROR(EIO));
1695 }
1696
1697 /*
1698 * In order to prevent the zgd's lwb from being free'd prior to
1699 * dmu_sync_late_arrival_done() being called, we have to ensure
1700 * the lwb's "max txg" takes this tx's txg into account.
1701 */
1702 zil_lwb_add_txg(zgd->zgd_lwb, dmu_tx_get_txg(tx));
1703
1704 dsa = kmem_alloc(sizeof (dmu_sync_arg_t), KM_SLEEP);
1705 dsa->dsa_dr = NULL;
1706 dsa->dsa_done = done;
1707 dsa->dsa_zgd = zgd;
1708 dsa->dsa_tx = tx;
1709
1710 /*
1711 * Since we are currently syncing this txg, it's nontrivial to
1712 * determine what BP to nopwrite against, so we disable nopwrite.
1713 *
1714 * When syncing, the db_blkptr is initially the BP of the previous
1715 * txg. We can not nopwrite against it because it will be changed
1716 * (this is similar to the non-late-arrival case where the dbuf is
1717 * dirty in a future txg).
1718 *
1719 * Then dbuf_write_ready() sets bp_blkptr to the location we will write.
1720 * We can not nopwrite against it because although the BP will not
1721 * (typically) be changed, the data has not yet been persisted to this
1722 * location.
1723 *
1724 * Finally, when dbuf_write_done() is called, it is theoretically
1725 * possible to always nopwrite, because the data that was written in
1726 * this txg is the same data that we are trying to write. However we
1727 * would need to check that this dbuf is not dirty in any future
1728 * txg's (as we do in the normal dmu_sync() path). For simplicity, we
1729 * don't nopwrite in this case.
1730 */
1731 zp->zp_nopwrite = B_FALSE;
1732
1733 zio_nowait(zio_write(pio, os->os_spa, dmu_tx_get_txg(tx), zgd->zgd_bp,
1734 abd_get_from_buf(zgd->zgd_db->db_data, zgd->zgd_db->db_size),
1735 zgd->zgd_db->db_size, zgd->zgd_db->db_size, zp,
1736 dmu_sync_late_arrival_ready, NULL, dmu_sync_late_arrival_done,
1737 dsa, ZIO_PRIORITY_SYNC_WRITE, ZIO_FLAG_CANFAIL, zb));
1738
1739 return (0);
1740 }
1741
1742 /*
1743 * Intent log support: sync the block associated with db to disk.
1744 * N.B. and XXX: the caller is responsible for making sure that the
1745 * data isn't changing while dmu_sync() is writing it.
1746 *
1747 * Return values:
1748 *
1749 * EEXIST: this txg has already been synced, so there's nothing to do.
1750 * The caller should not log the write.
1751 *
1752 * ENOENT: the block was dbuf_free_range()'d, so there's nothing to do.
1753 * The caller should not log the write.
1754 *
1755 * EALREADY: this block is already in the process of being synced.
1756 * The caller should track its progress (somehow).
1757 *
1758 * EIO: could not do the I/O.
1759 * The caller should do a txg_wait_synced().
1760 *
1761 * 0: the I/O has been initiated.
1762 * The caller should log this blkptr in the done callback.
1763 * It is possible that the I/O will fail, in which case
1764 * the error will be reported to the done callback and
1765 * propagated to pio from zio_done().
1766 */
1767 int
1768 dmu_sync(zio_t *pio, uint64_t txg, dmu_sync_cb_t *done, zgd_t *zgd)
1769 {
1770 dmu_buf_impl_t *db = (dmu_buf_impl_t *)zgd->zgd_db;
1771 objset_t *os = db->db_objset;
1772 dsl_dataset_t *ds = os->os_dsl_dataset;
1773 dbuf_dirty_record_t *dr, *dr_next;
1774 dmu_sync_arg_t *dsa;
1775 zbookmark_phys_t zb;
1776 zio_prop_t zp;
1777 dnode_t *dn;
1778
1779 ASSERT(pio != NULL);
1780 ASSERT(txg != 0);
1781
1782 SET_BOOKMARK(&zb, ds->ds_object,
1783 db->db.db_object, db->db_level, db->db_blkid);
1784
1785 DB_DNODE_ENTER(db);
1786 dn = DB_DNODE(db);
1787 dmu_write_policy(os, dn, db->db_level, WP_DMU_SYNC, &zp);
1788 DB_DNODE_EXIT(db);
1789
1790 /*
1791 * If we're frozen (running ziltest), we always need to generate a bp.
1792 */
1793 if (txg > spa_freeze_txg(os->os_spa))
1794 return (dmu_sync_late_arrival(pio, os, done, zgd, &zp, &zb));
1795
1796 /*
1797 * Grabbing db_mtx now provides a barrier between dbuf_sync_leaf()
1798 * and us. If we determine that this txg is not yet syncing,
1799 * but it begins to sync a moment later, that's OK because the
1800 * sync thread will block in dbuf_sync_leaf() until we drop db_mtx.
1801 */
1802 mutex_enter(&db->db_mtx);
1803
1804 if (txg <= spa_last_synced_txg(os->os_spa)) {
1805 /*
1806 * This txg has already synced. There's nothing to do.
1807 */
1808 mutex_exit(&db->db_mtx);
1809 return (SET_ERROR(EEXIST));
1810 }
1811
1812 if (txg <= spa_syncing_txg(os->os_spa)) {
1813 /*
1814 * This txg is currently syncing, so we can't mess with
1815 * the dirty record anymore; just write a new log block.
1816 */
1817 mutex_exit(&db->db_mtx);
1818 return (dmu_sync_late_arrival(pio, os, done, zgd, &zp, &zb));
1819 }
1820
1821 dr = dbuf_find_dirty_eq(db, txg);
1822
1823 if (dr == NULL) {
1824 /*
1825 * There's no dr for this dbuf, so it must have been freed.
1826 * There's no need to log writes to freed blocks, so we're done.
1827 */
1828 mutex_exit(&db->db_mtx);
1829 return (SET_ERROR(ENOENT));
1830 }
1831
1832 dr_next = list_next(&db->db_dirty_records, dr);
1833 ASSERT(dr_next == NULL || dr_next->dr_txg < txg);
1834
1835 if (db->db_blkptr != NULL) {
1836 /*
1837 * We need to fill in zgd_bp with the current blkptr so that
1838 * the nopwrite code can check if we're writing the same
1839 * data that's already on disk. We can only nopwrite if we
1840 * are sure that after making the copy, db_blkptr will not
1841 * change until our i/o completes. We ensure this by
1842 * holding the db_mtx, and only allowing nopwrite if the
1843 * block is not already dirty (see below). This is verified
1844 * by dmu_sync_done(), which VERIFYs that the db_blkptr has
1845 * not changed.
1846 */
1847 *zgd->zgd_bp = *db->db_blkptr;
1848 }
1849
1850 /*
1851 * Assume the on-disk data is X, the current syncing data (in
1852 * txg - 1) is Y, and the current in-memory data is Z (currently
1853 * in dmu_sync).
1854 *
1855 * We usually want to perform a nopwrite if X and Z are the
1856 * same. However, if Y is different (i.e. the BP is going to
1857 * change before this write takes effect), then a nopwrite will
1858 * be incorrect - we would override with X, which could have
1859 * been freed when Y was written.
1860 *
1861 * (Note that this is not a concern when we are nop-writing from
1862 * syncing context, because X and Y must be identical, because
1863 * all previous txgs have been synced.)
1864 *
1865 * Therefore, we disable nopwrite if the current BP could change
1866 * before this TXG. There are two ways it could change: by
1867 * being dirty (dr_next is non-NULL), or by being freed
1868 * (dnode_block_freed()). This behavior is verified by
1869 * zio_done(), which VERIFYs that the override BP is identical
1870 * to the on-disk BP.
1871 */
1872 DB_DNODE_ENTER(db);
1873 dn = DB_DNODE(db);
1874 if (dr_next != NULL || dnode_block_freed(dn, db->db_blkid))
1875 zp.zp_nopwrite = B_FALSE;
1876 DB_DNODE_EXIT(db);
1877
1878 ASSERT(dr->dr_txg == txg);
1879 if (dr->dt.dl.dr_override_state == DR_IN_DMU_SYNC ||
1880 dr->dt.dl.dr_override_state == DR_OVERRIDDEN) {
1881 /*
1882 * We have already issued a sync write for this buffer,
1883 * or this buffer has already been synced. It could not
1884 * have been dirtied since, or we would have cleared the state.
1885 */
1886 mutex_exit(&db->db_mtx);
1887 return (SET_ERROR(EALREADY));
1888 }
1889
1890 ASSERT(dr->dt.dl.dr_override_state == DR_NOT_OVERRIDDEN);
1891 dr->dt.dl.dr_override_state = DR_IN_DMU_SYNC;
1892 mutex_exit(&db->db_mtx);
1893
1894 dsa = kmem_alloc(sizeof (dmu_sync_arg_t), KM_SLEEP);
1895 dsa->dsa_dr = dr;
1896 dsa->dsa_done = done;
1897 dsa->dsa_zgd = zgd;
1898 dsa->dsa_tx = NULL;
1899
1900 zio_nowait(arc_write(pio, os->os_spa, txg, zgd->zgd_bp,
1901 dr->dt.dl.dr_data, !DBUF_IS_CACHEABLE(db), dbuf_is_l2cacheable(db),
1902 &zp, dmu_sync_ready, NULL, dmu_sync_done, dsa,
1903 ZIO_PRIORITY_SYNC_WRITE, ZIO_FLAG_CANFAIL, &zb));
1904
1905 return (0);
1906 }
1907
1908 int
1909 dmu_object_set_nlevels(objset_t *os, uint64_t object, int nlevels, dmu_tx_t *tx)
1910 {
1911 dnode_t *dn;
1912 int err;
1913
1914 err = dnode_hold(os, object, FTAG, &dn);
1915 if (err)
1916 return (err);
1917 err = dnode_set_nlevels(dn, nlevels, tx);
1918 dnode_rele(dn, FTAG);
1919 return (err);
1920 }
1921
1922 int
1923 dmu_object_set_blocksize(objset_t *os, uint64_t object, uint64_t size, int ibs,
1924 dmu_tx_t *tx)
1925 {
1926 dnode_t *dn;
1927 int err;
1928
1929 err = dnode_hold(os, object, FTAG, &dn);
1930 if (err)
1931 return (err);
1932 err = dnode_set_blksz(dn, size, ibs, tx);
1933 dnode_rele(dn, FTAG);
1934 return (err);
1935 }
1936
1937 int
1938 dmu_object_set_maxblkid(objset_t *os, uint64_t object, uint64_t maxblkid,
1939 dmu_tx_t *tx)
1940 {
1941 dnode_t *dn;
1942 int err;
1943
1944 err = dnode_hold(os, object, FTAG, &dn);
1945 if (err)
1946 return (err);
1947 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
1948 dnode_new_blkid(dn, maxblkid, tx, B_FALSE, B_TRUE);
1949 rw_exit(&dn->dn_struct_rwlock);
1950 dnode_rele(dn, FTAG);
1951 return (0);
1952 }
1953
1954 void
1955 dmu_object_set_checksum(objset_t *os, uint64_t object, uint8_t checksum,
1956 dmu_tx_t *tx)
1957 {
1958 dnode_t *dn;
1959
1960 /*
1961 * Send streams include each object's checksum function. This
1962 * check ensures that the receiving system can understand the
1963 * checksum function transmitted.
1964 */
1965 ASSERT3U(checksum, <, ZIO_CHECKSUM_LEGACY_FUNCTIONS);
1966
1967 VERIFY0(dnode_hold(os, object, FTAG, &dn));
1968 ASSERT3U(checksum, <, ZIO_CHECKSUM_FUNCTIONS);
1969 dn->dn_checksum = checksum;
1970 dnode_setdirty(dn, tx);
1971 dnode_rele(dn, FTAG);
1972 }
1973
1974 void
1975 dmu_object_set_compress(objset_t *os, uint64_t object, uint8_t compress,
1976 dmu_tx_t *tx)
1977 {
1978 dnode_t *dn;
1979
1980 /*
1981 * Send streams include each object's compression function. This
1982 * check ensures that the receiving system can understand the
1983 * compression function transmitted.
1984 */
1985 ASSERT3U(compress, <, ZIO_COMPRESS_LEGACY_FUNCTIONS);
1986
1987 VERIFY0(dnode_hold(os, object, FTAG, &dn));
1988 dn->dn_compress = compress;
1989 dnode_setdirty(dn, tx);
1990 dnode_rele(dn, FTAG);
1991 }
1992
1993 /*
1994 * When the "redundant_metadata" property is set to "most", only indirect
1995 * blocks of this level and higher will have an additional ditto block.
1996 */
1997 static const int zfs_redundant_metadata_most_ditto_level = 2;
1998
1999 void
2000 dmu_write_policy(objset_t *os, dnode_t *dn, int level, int wp, zio_prop_t *zp)
2001 {
2002 dmu_object_type_t type = dn ? dn->dn_type : DMU_OT_OBJSET;
2003 boolean_t ismd = (level > 0 || DMU_OT_IS_METADATA(type) ||
2004 (wp & WP_SPILL));
2005 enum zio_checksum checksum = os->os_checksum;
2006 enum zio_compress compress = os->os_compress;
2007 uint8_t complevel = os->os_complevel;
2008 enum zio_checksum dedup_checksum = os->os_dedup_checksum;
2009 boolean_t dedup = B_FALSE;
2010 boolean_t nopwrite = B_FALSE;
2011 boolean_t dedup_verify = os->os_dedup_verify;
2012 boolean_t encrypt = B_FALSE;
2013 int copies = os->os_copies;
2014
2015 /*
2016 * We maintain different write policies for each of the following
2017 * types of data:
2018 * 1. metadata
2019 * 2. preallocated blocks (i.e. level-0 blocks of a dump device)
2020 * 3. all other level 0 blocks
2021 */
2022 if (ismd) {
2023 /*
2024 * XXX -- we should design a compression algorithm
2025 * that specializes in arrays of bps.
2026 */
2027 compress = zio_compress_select(os->os_spa,
2028 ZIO_COMPRESS_ON, ZIO_COMPRESS_ON);
2029
2030 /*
2031 * Metadata always gets checksummed. If the data
2032 * checksum is multi-bit correctable, and it's not a
2033 * ZBT-style checksum, then it's suitable for metadata
2034 * as well. Otherwise, the metadata checksum defaults
2035 * to fletcher4.
2036 */
2037 if (!(zio_checksum_table[checksum].ci_flags &
2038 ZCHECKSUM_FLAG_METADATA) ||
2039 (zio_checksum_table[checksum].ci_flags &
2040 ZCHECKSUM_FLAG_EMBEDDED))
2041 checksum = ZIO_CHECKSUM_FLETCHER_4;
2042
2043 switch (os->os_redundant_metadata) {
2044 case ZFS_REDUNDANT_METADATA_ALL:
2045 copies++;
2046 break;
2047 case ZFS_REDUNDANT_METADATA_MOST:
2048 if (level >= zfs_redundant_metadata_most_ditto_level ||
2049 DMU_OT_IS_METADATA(type) || (wp & WP_SPILL))
2050 copies++;
2051 break;
2052 case ZFS_REDUNDANT_METADATA_SOME:
2053 if (DMU_OT_IS_CRITICAL(type))
2054 copies++;
2055 break;
2056 case ZFS_REDUNDANT_METADATA_NONE:
2057 break;
2058 }
2059 } else if (wp & WP_NOFILL) {
2060 ASSERT(level == 0);
2061
2062 /*
2063 * If we're writing preallocated blocks, we aren't actually
2064 * writing them so don't set any policy properties. These
2065 * blocks are currently only used by an external subsystem
2066 * outside of zfs (i.e. dump) and not written by the zio
2067 * pipeline.
2068 */
2069 compress = ZIO_COMPRESS_OFF;
2070 checksum = ZIO_CHECKSUM_OFF;
2071 } else {
2072 compress = zio_compress_select(os->os_spa, dn->dn_compress,
2073 compress);
2074 complevel = zio_complevel_select(os->os_spa, compress,
2075 complevel, complevel);
2076
2077 checksum = (dedup_checksum == ZIO_CHECKSUM_OFF) ?
2078 zio_checksum_select(dn->dn_checksum, checksum) :
2079 dedup_checksum;
2080
2081 /*
2082 * Determine dedup setting. If we are in dmu_sync(),
2083 * we won't actually dedup now because that's all
2084 * done in syncing context; but we do want to use the
2085 * dedup checksum. If the checksum is not strong
2086 * enough to ensure unique signatures, force
2087 * dedup_verify.
2088 */
2089 if (dedup_checksum != ZIO_CHECKSUM_OFF) {
2090 dedup = (wp & WP_DMU_SYNC) ? B_FALSE : B_TRUE;
2091 if (!(zio_checksum_table[checksum].ci_flags &
2092 ZCHECKSUM_FLAG_DEDUP))
2093 dedup_verify = B_TRUE;
2094 }
2095
2096 /*
2097 * Enable nopwrite if we have secure enough checksum
2098 * algorithm (see comment in zio_nop_write) and
2099 * compression is enabled. We don't enable nopwrite if
2100 * dedup is enabled as the two features are mutually
2101 * exclusive.
2102 */
2103 nopwrite = (!dedup && (zio_checksum_table[checksum].ci_flags &
2104 ZCHECKSUM_FLAG_NOPWRITE) &&
2105 compress != ZIO_COMPRESS_OFF && zfs_nopwrite_enabled);
2106 }
2107
2108 /*
2109 * All objects in an encrypted objset are protected from modification
2110 * via a MAC. Encrypted objects store their IV and salt in the last DVA
2111 * in the bp, so we cannot use all copies. Encrypted objects are also
2112 * not subject to nopwrite since writing the same data will still
2113 * result in a new ciphertext. Only encrypted blocks can be dedup'd
2114 * to avoid ambiguity in the dedup code since the DDT does not store
2115 * object types.
2116 */
2117 if (os->os_encrypted && (wp & WP_NOFILL) == 0) {
2118 encrypt = B_TRUE;
2119
2120 if (DMU_OT_IS_ENCRYPTED(type)) {
2121 copies = MIN(copies, SPA_DVAS_PER_BP - 1);
2122 nopwrite = B_FALSE;
2123 } else {
2124 dedup = B_FALSE;
2125 }
2126
2127 if (level <= 0 &&
2128 (type == DMU_OT_DNODE || type == DMU_OT_OBJSET)) {
2129 compress = ZIO_COMPRESS_EMPTY;
2130 }
2131 }
2132
2133 zp->zp_compress = compress;
2134 zp->zp_complevel = complevel;
2135 zp->zp_checksum = checksum;
2136 zp->zp_type = (wp & WP_SPILL) ? dn->dn_bonustype : type;
2137 zp->zp_level = level;
2138 zp->zp_copies = MIN(copies, spa_max_replication(os->os_spa));
2139 zp->zp_dedup = dedup;
2140 zp->zp_dedup_verify = dedup && dedup_verify;
2141 zp->zp_nopwrite = nopwrite;
2142 zp->zp_encrypt = encrypt;
2143 zp->zp_byteorder = ZFS_HOST_BYTEORDER;
2144 memset(zp->zp_salt, 0, ZIO_DATA_SALT_LEN);
2145 memset(zp->zp_iv, 0, ZIO_DATA_IV_LEN);
2146 memset(zp->zp_mac, 0, ZIO_DATA_MAC_LEN);
2147 zp->zp_zpl_smallblk = DMU_OT_IS_FILE(zp->zp_type) ?
2148 os->os_zpl_special_smallblock : 0;
2149
2150 ASSERT3U(zp->zp_compress, !=, ZIO_COMPRESS_INHERIT);
2151 }
2152
2153 /*
2154 * Reports the location of data and holes in an object. In order to
2155 * accurately report holes all dirty data must be synced to disk. This
2156 * causes extremely poor performance when seeking for holes in a dirty file.
2157 * As a compromise, only provide hole data when the dnode is clean. When
2158 * a dnode is dirty report the dnode as having no holes by returning EBUSY
2159 * which is always safe to do.
2160 */
2161 int
2162 dmu_offset_next(objset_t *os, uint64_t object, boolean_t hole, uint64_t *off)
2163 {
2164 dnode_t *dn;
2165 int restarted = 0, err;
2166
2167 restart:
2168 err = dnode_hold(os, object, FTAG, &dn);
2169 if (err)
2170 return (err);
2171
2172 rw_enter(&dn->dn_struct_rwlock, RW_READER);
2173
2174 if (dnode_is_dirty(dn)) {
2175 /*
2176 * If the zfs_dmu_offset_next_sync module option is enabled
2177 * then hole reporting has been requested. Dirty dnodes
2178 * must be synced to disk to accurately report holes.
2179 *
2180 * Provided a RL_READER rangelock spanning 0-UINT64_MAX is
2181 * held by the caller only a single restart will be required.
2182 * We tolerate callers which do not hold the rangelock by
2183 * returning EBUSY and not reporting holes after one restart.
2184 */
2185 if (zfs_dmu_offset_next_sync) {
2186 rw_exit(&dn->dn_struct_rwlock);
2187 dnode_rele(dn, FTAG);
2188
2189 if (restarted)
2190 return (SET_ERROR(EBUSY));
2191
2192 txg_wait_synced(dmu_objset_pool(os), 0);
2193 restarted = 1;
2194 goto restart;
2195 }
2196
2197 err = SET_ERROR(EBUSY);
2198 } else {
2199 err = dnode_next_offset(dn, DNODE_FIND_HAVELOCK |
2200 (hole ? DNODE_FIND_HOLE : 0), off, 1, 1, 0);
2201 }
2202
2203 rw_exit(&dn->dn_struct_rwlock);
2204 dnode_rele(dn, FTAG);
2205
2206 return (err);
2207 }
2208
2209 int
2210 dmu_read_l0_bps(objset_t *os, uint64_t object, uint64_t offset, uint64_t length,
2211 blkptr_t *bps, size_t *nbpsp)
2212 {
2213 dmu_buf_t **dbp, *dbuf;
2214 dmu_buf_impl_t *db;
2215 blkptr_t *bp;
2216 int error, numbufs;
2217
2218 error = dmu_buf_hold_array(os, object, offset, length, FALSE, FTAG,
2219 &numbufs, &dbp);
2220 if (error != 0) {
2221 if (error == ESRCH) {
2222 error = SET_ERROR(ENXIO);
2223 }
2224 return (error);
2225 }
2226
2227 ASSERT3U(numbufs, <=, *nbpsp);
2228
2229 for (int i = 0; i < numbufs; i++) {
2230 dbuf = dbp[i];
2231 db = (dmu_buf_impl_t *)dbuf;
2232
2233 mutex_enter(&db->db_mtx);
2234
2235 if (!list_is_empty(&db->db_dirty_records)) {
2236 dbuf_dirty_record_t *dr;
2237
2238 dr = list_head(&db->db_dirty_records);
2239 if (dr->dt.dl.dr_brtwrite) {
2240 /*
2241 * This is very special case where we clone a
2242 * block and in the same transaction group we
2243 * read its BP (most likely to clone the clone).
2244 */
2245 bp = &dr->dt.dl.dr_overridden_by;
2246 } else {
2247 /*
2248 * The block was modified in the same
2249 * transaction group.
2250 */
2251 mutex_exit(&db->db_mtx);
2252 error = SET_ERROR(EAGAIN);
2253 goto out;
2254 }
2255 } else {
2256 bp = db->db_blkptr;
2257 }
2258
2259 mutex_exit(&db->db_mtx);
2260
2261 if (bp == NULL) {
2262 /*
2263 * The block was created in this transaction group,
2264 * so it has no BP yet.
2265 */
2266 error = SET_ERROR(EAGAIN);
2267 goto out;
2268 }
2269 /*
2270 * Make sure we clone only data blocks.
2271 */
2272 if (BP_IS_METADATA(bp) && !BP_IS_HOLE(bp)) {
2273 error = SET_ERROR(EINVAL);
2274 goto out;
2275 }
2276
2277 bps[i] = *bp;
2278 }
2279
2280 *nbpsp = numbufs;
2281 out:
2282 dmu_buf_rele_array(dbp, numbufs, FTAG);
2283
2284 return (error);
2285 }
2286
2287 int
2288 dmu_brt_clone(objset_t *os, uint64_t object, uint64_t offset, uint64_t length,
2289 dmu_tx_t *tx, const blkptr_t *bps, size_t nbps)
2290 {
2291 spa_t *spa;
2292 dmu_buf_t **dbp, *dbuf;
2293 dmu_buf_impl_t *db;
2294 struct dirty_leaf *dl;
2295 dbuf_dirty_record_t *dr;
2296 const blkptr_t *bp;
2297 int error = 0, i, numbufs;
2298
2299 spa = os->os_spa;
2300
2301 VERIFY0(dmu_buf_hold_array(os, object, offset, length, FALSE, FTAG,
2302 &numbufs, &dbp));
2303 ASSERT3U(nbps, ==, numbufs);
2304
2305 /*
2306 * Before we start cloning make sure that the dbufs sizes match new BPs
2307 * sizes. If they don't, that's a no-go, as we are not able to shrink
2308 * dbufs.
2309 */
2310 for (i = 0; i < numbufs; i++) {
2311 dbuf = dbp[i];
2312 db = (dmu_buf_impl_t *)dbuf;
2313 bp = &bps[i];
2314
2315 ASSERT0(db->db_level);
2316 ASSERT(db->db_blkid != DMU_BONUS_BLKID);
2317 ASSERT(db->db_blkid != DMU_SPILL_BLKID);
2318
2319 if (!BP_IS_HOLE(bp) && BP_GET_LSIZE(bp) != dbuf->db_size) {
2320 error = SET_ERROR(EXDEV);
2321 goto out;
2322 }
2323 }
2324
2325 for (i = 0; i < numbufs; i++) {
2326 dbuf = dbp[i];
2327 db = (dmu_buf_impl_t *)dbuf;
2328 bp = &bps[i];
2329
2330 ASSERT0(db->db_level);
2331 ASSERT(db->db_blkid != DMU_BONUS_BLKID);
2332 ASSERT(db->db_blkid != DMU_SPILL_BLKID);
2333 ASSERT(BP_IS_HOLE(bp) || dbuf->db_size == BP_GET_LSIZE(bp));
2334
2335 dmu_buf_will_clone(dbuf, tx);
2336
2337 mutex_enter(&db->db_mtx);
2338
2339 dr = list_head(&db->db_dirty_records);
2340 VERIFY(dr != NULL);
2341 ASSERT3U(dr->dr_txg, ==, tx->tx_txg);
2342 dl = &dr->dt.dl;
2343 dl->dr_overridden_by = *bp;
2344 dl->dr_brtwrite = B_TRUE;
2345 dl->dr_override_state = DR_OVERRIDDEN;
2346 if (BP_IS_HOLE(bp)) {
2347 dl->dr_overridden_by.blk_birth = 0;
2348 dl->dr_overridden_by.blk_phys_birth = 0;
2349 } else {
2350 dl->dr_overridden_by.blk_birth = dr->dr_txg;
2351 if (!BP_IS_EMBEDDED(bp)) {
2352 dl->dr_overridden_by.blk_phys_birth =
2353 BP_PHYSICAL_BIRTH(bp);
2354 }
2355 }
2356
2357 mutex_exit(&db->db_mtx);
2358
2359 /*
2360 * When data in embedded into BP there is no need to create
2361 * BRT entry as there is no data block. Just copy the BP as
2362 * it contains the data.
2363 */
2364 if (!BP_IS_HOLE(bp) && !BP_IS_EMBEDDED(bp)) {
2365 brt_pending_add(spa, bp, tx);
2366 }
2367 }
2368 out:
2369 dmu_buf_rele_array(dbp, numbufs, FTAG);
2370
2371 return (error);
2372 }
2373
2374 void
2375 __dmu_object_info_from_dnode(dnode_t *dn, dmu_object_info_t *doi)
2376 {
2377 dnode_phys_t *dnp = dn->dn_phys;
2378
2379 doi->doi_data_block_size = dn->dn_datablksz;
2380 doi->doi_metadata_block_size = dn->dn_indblkshift ?
2381 1ULL << dn->dn_indblkshift : 0;
2382 doi->doi_type = dn->dn_type;
2383 doi->doi_bonus_type = dn->dn_bonustype;
2384 doi->doi_bonus_size = dn->dn_bonuslen;
2385 doi->doi_dnodesize = dn->dn_num_slots << DNODE_SHIFT;
2386 doi->doi_indirection = dn->dn_nlevels;
2387 doi->doi_checksum = dn->dn_checksum;
2388 doi->doi_compress = dn->dn_compress;
2389 doi->doi_nblkptr = dn->dn_nblkptr;
2390 doi->doi_physical_blocks_512 = (DN_USED_BYTES(dnp) + 256) >> 9;
2391 doi->doi_max_offset = (dn->dn_maxblkid + 1) * dn->dn_datablksz;
2392 doi->doi_fill_count = 0;
2393 for (int i = 0; i < dnp->dn_nblkptr; i++)
2394 doi->doi_fill_count += BP_GET_FILL(&dnp->dn_blkptr[i]);
2395 }
2396
2397 void
2398 dmu_object_info_from_dnode(dnode_t *dn, dmu_object_info_t *doi)
2399 {
2400 rw_enter(&dn->dn_struct_rwlock, RW_READER);
2401 mutex_enter(&dn->dn_mtx);
2402
2403 __dmu_object_info_from_dnode(dn, doi);
2404
2405 mutex_exit(&dn->dn_mtx);
2406 rw_exit(&dn->dn_struct_rwlock);
2407 }
2408
2409 /*
2410 * Get information on a DMU object.
2411 * If doi is NULL, just indicates whether the object exists.
2412 */
2413 int
2414 dmu_object_info(objset_t *os, uint64_t object, dmu_object_info_t *doi)
2415 {
2416 dnode_t *dn;
2417 int err = dnode_hold(os, object, FTAG, &dn);
2418
2419 if (err)
2420 return (err);
2421
2422 if (doi != NULL)
2423 dmu_object_info_from_dnode(dn, doi);
2424
2425 dnode_rele(dn, FTAG);
2426 return (0);
2427 }
2428
2429 /*
2430 * As above, but faster; can be used when you have a held dbuf in hand.
2431 */
2432 void
2433 dmu_object_info_from_db(dmu_buf_t *db_fake, dmu_object_info_t *doi)
2434 {
2435 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
2436
2437 DB_DNODE_ENTER(db);
2438 dmu_object_info_from_dnode(DB_DNODE(db), doi);
2439 DB_DNODE_EXIT(db);
2440 }
2441
2442 /*
2443 * Faster still when you only care about the size.
2444 */
2445 void
2446 dmu_object_size_from_db(dmu_buf_t *db_fake, uint32_t *blksize,
2447 u_longlong_t *nblk512)
2448 {
2449 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
2450 dnode_t *dn;
2451
2452 DB_DNODE_ENTER(db);
2453 dn = DB_DNODE(db);
2454
2455 *blksize = dn->dn_datablksz;
2456 /* add in number of slots used for the dnode itself */
2457 *nblk512 = ((DN_USED_BYTES(dn->dn_phys) + SPA_MINBLOCKSIZE/2) >>
2458 SPA_MINBLOCKSHIFT) + dn->dn_num_slots;
2459 DB_DNODE_EXIT(db);
2460 }
2461
2462 void
2463 dmu_object_dnsize_from_db(dmu_buf_t *db_fake, int *dnsize)
2464 {
2465 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
2466 dnode_t *dn;
2467
2468 DB_DNODE_ENTER(db);
2469 dn = DB_DNODE(db);
2470 *dnsize = dn->dn_num_slots << DNODE_SHIFT;
2471 DB_DNODE_EXIT(db);
2472 }
2473
2474 void
2475 byteswap_uint64_array(void *vbuf, size_t size)
2476 {
2477 uint64_t *buf = vbuf;
2478 size_t count = size >> 3;
2479 int i;
2480
2481 ASSERT((size & 7) == 0);
2482
2483 for (i = 0; i < count; i++)
2484 buf[i] = BSWAP_64(buf[i]);
2485 }
2486
2487 void
2488 byteswap_uint32_array(void *vbuf, size_t size)
2489 {
2490 uint32_t *buf = vbuf;
2491 size_t count = size >> 2;
2492 int i;
2493
2494 ASSERT((size & 3) == 0);
2495
2496 for (i = 0; i < count; i++)
2497 buf[i] = BSWAP_32(buf[i]);
2498 }
2499
2500 void
2501 byteswap_uint16_array(void *vbuf, size_t size)
2502 {
2503 uint16_t *buf = vbuf;
2504 size_t count = size >> 1;
2505 int i;
2506
2507 ASSERT((size & 1) == 0);
2508
2509 for (i = 0; i < count; i++)
2510 buf[i] = BSWAP_16(buf[i]);
2511 }
2512
2513 void
2514 byteswap_uint8_array(void *vbuf, size_t size)
2515 {
2516 (void) vbuf, (void) size;
2517 }
2518
2519 void
2520 dmu_init(void)
2521 {
2522 abd_init();
2523 zfs_dbgmsg_init();
2524 sa_cache_init();
2525 dmu_objset_init();
2526 dnode_init();
2527 zfetch_init();
2528 dmu_tx_init();
2529 l2arc_init();
2530 arc_init();
2531 dbuf_init();
2532 }
2533
2534 void
2535 dmu_fini(void)
2536 {
2537 arc_fini(); /* arc depends on l2arc, so arc must go first */
2538 l2arc_fini();
2539 dmu_tx_fini();
2540 zfetch_fini();
2541 dbuf_fini();
2542 dnode_fini();
2543 dmu_objset_fini();
2544 sa_cache_fini();
2545 zfs_dbgmsg_fini();
2546 abd_fini();
2547 }
2548
2549 EXPORT_SYMBOL(dmu_bonus_hold);
2550 EXPORT_SYMBOL(dmu_bonus_hold_by_dnode);
2551 EXPORT_SYMBOL(dmu_buf_hold_array_by_bonus);
2552 EXPORT_SYMBOL(dmu_buf_rele_array);
2553 EXPORT_SYMBOL(dmu_prefetch);
2554 EXPORT_SYMBOL(dmu_free_range);
2555 EXPORT_SYMBOL(dmu_free_long_range);
2556 EXPORT_SYMBOL(dmu_free_long_object);
2557 EXPORT_SYMBOL(dmu_read);
2558 EXPORT_SYMBOL(dmu_read_by_dnode);
2559 EXPORT_SYMBOL(dmu_write);
2560 EXPORT_SYMBOL(dmu_write_by_dnode);
2561 EXPORT_SYMBOL(dmu_prealloc);
2562 EXPORT_SYMBOL(dmu_object_info);
2563 EXPORT_SYMBOL(dmu_object_info_from_dnode);
2564 EXPORT_SYMBOL(dmu_object_info_from_db);
2565 EXPORT_SYMBOL(dmu_object_size_from_db);
2566 EXPORT_SYMBOL(dmu_object_dnsize_from_db);
2567 EXPORT_SYMBOL(dmu_object_set_nlevels);
2568 EXPORT_SYMBOL(dmu_object_set_blocksize);
2569 EXPORT_SYMBOL(dmu_object_set_maxblkid);
2570 EXPORT_SYMBOL(dmu_object_set_checksum);
2571 EXPORT_SYMBOL(dmu_object_set_compress);
2572 EXPORT_SYMBOL(dmu_offset_next);
2573 EXPORT_SYMBOL(dmu_write_policy);
2574 EXPORT_SYMBOL(dmu_sync);
2575 EXPORT_SYMBOL(dmu_request_arcbuf);
2576 EXPORT_SYMBOL(dmu_return_arcbuf);
2577 EXPORT_SYMBOL(dmu_assign_arcbuf_by_dnode);
2578 EXPORT_SYMBOL(dmu_assign_arcbuf_by_dbuf);
2579 EXPORT_SYMBOL(dmu_buf_hold);
2580 EXPORT_SYMBOL(dmu_ot);
2581
2582 ZFS_MODULE_PARAM(zfs, zfs_, nopwrite_enabled, INT, ZMOD_RW,
2583 "Enable NOP writes");
2584
2585 ZFS_MODULE_PARAM(zfs, zfs_, per_txg_dirty_frees_percent, UINT, ZMOD_RW,
2586 "Percentage of dirtied blocks from frees in one TXG");
2587
2588 ZFS_MODULE_PARAM(zfs, zfs_, dmu_offset_next_sync, INT, ZMOD_RW,
2589 "Enable forcing txg sync to find holes");
2590
2591 /* CSTYLED */
2592 ZFS_MODULE_PARAM(zfs, , dmu_prefetch_max, UINT, ZMOD_RW,
2593 "Limit one prefetch call to this size");
ZFS On Linux mirror for PVE