1 // SPDX-License-Identifier: CDDL-1.0
2 /*
3 * CDDL HEADER START
4 *
5 * The contents of this file are subject to the terms of the
6 * Common Development and Distribution License (the "License").
7 * You may not use this file except in compliance with the License.
8 *
9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10 * or https://opensource.org/licenses/CDDL-1.0.
11 * See the License for the specific language governing permissions
12 * and limitations under the License.
13 *
14 * When distributing Covered Code, include this CDDL HEADER in each
15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16 * If applicable, add the following below this CDDL HEADER, with the
17 * fields enclosed by brackets "[]" replaced with your own identifying
18 * information: Portions Copyright [yyyy] [name of copyright owner]
19 *
20 * CDDL HEADER END
21 */
22 /*
23 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
24 * Copyright (c) 2011, 2020 by Delphix. All rights reserved.
25 * Copyright (c) 2013 by Saso Kiselkov. All rights reserved.
26 * Copyright (c) 2013, Joyent, Inc. All rights reserved.
27 * Copyright (c) 2016, Nexenta Systems, Inc. All rights reserved.
28 * Copyright (c) 2015 by Chunwei Chen. All rights reserved.
29 * Copyright (c) 2019 Datto Inc.
30 * Copyright (c) 2019, 2023, Klara Inc.
31 * Copyright (c) 2019, Allan Jude
32 * Copyright (c) 2022 Hewlett Packard Enterprise Development LP.
33 * Copyright (c) 2021, 2022 by Pawel Jakub Dawidek
34 */
35
36 #include <sys/dmu.h>
37 #include <sys/dmu_impl.h>
38 #include <sys/dmu_tx.h>
39 #include <sys/dbuf.h>
40 #include <sys/dnode.h>
41 #include <sys/zfs_context.h>
42 #include <sys/dmu_objset.h>
43 #include <sys/dmu_traverse.h>
44 #include <sys/dsl_dataset.h>
45 #include <sys/dsl_dir.h>
46 #include <sys/dsl_pool.h>
47 #include <sys/dsl_synctask.h>
48 #include <sys/dsl_prop.h>
49 #include <sys/dmu_zfetch.h>
50 #include <sys/zfs_ioctl.h>
51 #include <sys/zap.h>
52 #include <sys/zio_checksum.h>
53 #include <sys/zio_compress.h>
54 #include <sys/sa.h>
55 #include <sys/zfeature.h>
56 #include <sys/abd.h>
57 #include <sys/brt.h>
58 #include <sys/trace_zfs.h>
59 #include <sys/zfs_racct.h>
60 #include <sys/zfs_rlock.h>
61 #ifdef _KERNEL
62 #include <sys/vmsystm.h>
63 #include <sys/zfs_znode.h>
64 #endif
65
66 /*
67 * Enable/disable nopwrite feature.
68 */
69 static int zfs_nopwrite_enabled = 1;
70
71 /*
72 * Tunable to control percentage of dirtied L1 blocks from frees allowed into
73 * one TXG. After this threshold is crossed, additional dirty blocks from frees
74 * will wait until the next TXG.
75 * A value of zero will disable this throttle.
76 */
77 static uint_t zfs_per_txg_dirty_frees_percent = 30;
78
79 /*
80 * Enable/disable forcing txg sync when dirty checking for holes with lseek().
81 * By default this is enabled to ensure accurate hole reporting, it can result
82 * in a significant performance penalty for lseek(SEEK_HOLE) heavy workloads.
83 * Disabling this option will result in holes never being reported in dirty
84 * files which is always safe.
85 */
86 static int zfs_dmu_offset_next_sync = 1;
87
88 /*
89 * Limit the amount we can prefetch with one call to this amount. This
90 * helps to limit the amount of memory that can be used by prefetching.
91 * Larger objects should be prefetched a bit at a time.
92 */
93 #ifdef _ILP32
94 uint_t dmu_prefetch_max = 8 * 1024 * 1024;
95 #else
96 uint_t dmu_prefetch_max = 8 * SPA_MAXBLOCKSIZE;
97 #endif
98
99 /*
100 * Override copies= for dedup state objects. 0 means the traditional behaviour
101 * (ie the default for the containing objset ie 3 for the MOS).
102 */
103 uint_t dmu_ddt_copies = 0;
104
105 const dmu_object_type_info_t dmu_ot[DMU_OT_NUMTYPES] = {
106 {DMU_BSWAP_UINT8, TRUE, FALSE, FALSE, "unallocated" },
107 {DMU_BSWAP_ZAP, TRUE, TRUE, FALSE, "object directory" },
108 {DMU_BSWAP_UINT64, TRUE, TRUE, FALSE, "object array" },
109 {DMU_BSWAP_UINT8, TRUE, FALSE, FALSE, "packed nvlist" },
110 {DMU_BSWAP_UINT64, TRUE, FALSE, FALSE, "packed nvlist size" },
111 {DMU_BSWAP_UINT64, TRUE, FALSE, FALSE, "bpobj" },
112 {DMU_BSWAP_UINT64, TRUE, FALSE, FALSE, "bpobj header" },
113 {DMU_BSWAP_UINT64, TRUE, FALSE, FALSE, "SPA space map header" },
114 {DMU_BSWAP_UINT64, TRUE, FALSE, FALSE, "SPA space map" },
115 {DMU_BSWAP_UINT64, TRUE, FALSE, TRUE, "ZIL intent log" },
116 {DMU_BSWAP_DNODE, TRUE, FALSE, TRUE, "DMU dnode" },
117 {DMU_BSWAP_OBJSET, TRUE, TRUE, FALSE, "DMU objset" },
118 {DMU_BSWAP_UINT64, TRUE, TRUE, FALSE, "DSL directory" },
119 {DMU_BSWAP_ZAP, TRUE, TRUE, FALSE, "DSL directory child map"},
120 {DMU_BSWAP_ZAP, TRUE, TRUE, FALSE, "DSL dataset snap map" },
121 {DMU_BSWAP_ZAP, TRUE, TRUE, FALSE, "DSL props" },
122 {DMU_BSWAP_UINT64, TRUE, TRUE, FALSE, "DSL dataset" },
123 {DMU_BSWAP_ZNODE, TRUE, FALSE, FALSE, "ZFS znode" },
124 {DMU_BSWAP_OLDACL, TRUE, FALSE, TRUE, "ZFS V0 ACL" },
125 {DMU_BSWAP_UINT8, FALSE, FALSE, TRUE, "ZFS plain file" },
126 {DMU_BSWAP_ZAP, TRUE, FALSE, TRUE, "ZFS directory" },
127 {DMU_BSWAP_ZAP, TRUE, FALSE, FALSE, "ZFS master node" },
128 {DMU_BSWAP_ZAP, TRUE, FALSE, TRUE, "ZFS delete queue" },
129 {DMU_BSWAP_UINT8, FALSE, FALSE, TRUE, "zvol object" },
130 {DMU_BSWAP_ZAP, TRUE, FALSE, FALSE, "zvol prop" },
131 {DMU_BSWAP_UINT8, FALSE, FALSE, TRUE, "other uint8[]" },
132 {DMU_BSWAP_UINT64, FALSE, FALSE, TRUE, "other uint64[]" },
133 {DMU_BSWAP_ZAP, TRUE, FALSE, FALSE, "other ZAP" },
134 {DMU_BSWAP_ZAP, TRUE, FALSE, FALSE, "persistent error log" },
135 {DMU_BSWAP_UINT8, TRUE, FALSE, FALSE, "SPA history" },
136 {DMU_BSWAP_UINT64, TRUE, FALSE, FALSE, "SPA history offsets" },
137 {DMU_BSWAP_ZAP, TRUE, TRUE, FALSE, "Pool properties" },
138 {DMU_BSWAP_ZAP, TRUE, TRUE, FALSE, "DSL permissions" },
139 {DMU_BSWAP_ACL, TRUE, FALSE, TRUE, "ZFS ACL" },
140 {DMU_BSWAP_UINT8, TRUE, FALSE, TRUE, "ZFS SYSACL" },
141 {DMU_BSWAP_UINT8, TRUE, FALSE, TRUE, "FUID table" },
142 {DMU_BSWAP_UINT64, TRUE, FALSE, FALSE, "FUID table size" },
143 {DMU_BSWAP_ZAP, TRUE, TRUE, FALSE, "DSL dataset next clones"},
144 {DMU_BSWAP_ZAP, TRUE, FALSE, FALSE, "scan work queue" },
145 {DMU_BSWAP_ZAP, TRUE, FALSE, TRUE, "ZFS user/group/project used" },
146 {DMU_BSWAP_ZAP, TRUE, FALSE, TRUE, "ZFS user/group/project quota"},
147 {DMU_BSWAP_ZAP, TRUE, TRUE, FALSE, "snapshot refcount tags"},
148 {DMU_BSWAP_ZAP, TRUE, FALSE, FALSE, "DDT ZAP algorithm" },
149 {DMU_BSWAP_ZAP, TRUE, FALSE, FALSE, "DDT statistics" },
150 {DMU_BSWAP_UINT8, TRUE, FALSE, TRUE, "System attributes" },
151 {DMU_BSWAP_ZAP, TRUE, FALSE, TRUE, "SA master node" },
152 {DMU_BSWAP_ZAP, TRUE, FALSE, TRUE, "SA attr registration" },
153 {DMU_BSWAP_ZAP, TRUE, FALSE, TRUE, "SA attr layouts" },
154 {DMU_BSWAP_ZAP, TRUE, FALSE, FALSE, "scan translations" },
155 {DMU_BSWAP_UINT8, FALSE, FALSE, TRUE, "deduplicated block" },
156 {DMU_BSWAP_ZAP, TRUE, TRUE, FALSE, "DSL deadlist map" },
157 {DMU_BSWAP_UINT64, TRUE, TRUE, FALSE, "DSL deadlist map hdr" },
158 {DMU_BSWAP_ZAP, TRUE, TRUE, FALSE, "DSL dir clones" },
159 {DMU_BSWAP_UINT64, TRUE, FALSE, FALSE, "bpobj subobj" }
160 };
161
162 dmu_object_byteswap_info_t dmu_ot_byteswap[DMU_BSWAP_NUMFUNCS] = {
163 { byteswap_uint8_array, "uint8" },
164 { byteswap_uint16_array, "uint16" },
165 { byteswap_uint32_array, "uint32" },
166 { byteswap_uint64_array, "uint64" },
167 { zap_byteswap, "zap" },
168 { dnode_buf_byteswap, "dnode" },
169 { dmu_objset_byteswap, "objset" },
170 { zfs_znode_byteswap, "znode" },
171 { zfs_oldacl_byteswap, "oldacl" },
172 { zfs_acl_byteswap, "acl" }
173 };
174
175 int
dmu_buf_hold_noread_by_dnode(dnode_t * dn,uint64_t offset,const void * tag,dmu_buf_t ** dbp)176 dmu_buf_hold_noread_by_dnode(dnode_t *dn, uint64_t offset,
177 const void *tag, dmu_buf_t **dbp)
178 {
179 uint64_t blkid;
180 dmu_buf_impl_t *db;
181
182 rw_enter(&dn->dn_struct_rwlock, RW_READER);
183 blkid = dbuf_whichblock(dn, 0, offset);
184 db = dbuf_hold(dn, blkid, tag);
185 rw_exit(&dn->dn_struct_rwlock);
186
187 if (db == NULL) {
188 *dbp = NULL;
189 return (SET_ERROR(EIO));
190 }
191
192 *dbp = &db->db;
193 return (0);
194 }
195
196 int
dmu_buf_hold_noread(objset_t * os,uint64_t object,uint64_t offset,const void * tag,dmu_buf_t ** dbp)197 dmu_buf_hold_noread(objset_t *os, uint64_t object, uint64_t offset,
198 const void *tag, dmu_buf_t **dbp)
199 {
200 dnode_t *dn;
201 uint64_t blkid;
202 dmu_buf_impl_t *db;
203 int err;
204
205 err = dnode_hold(os, object, FTAG, &dn);
206 if (err)
207 return (err);
208 rw_enter(&dn->dn_struct_rwlock, RW_READER);
209 blkid = dbuf_whichblock(dn, 0, offset);
210 db = dbuf_hold(dn, blkid, tag);
211 rw_exit(&dn->dn_struct_rwlock);
212 dnode_rele(dn, FTAG);
213
214 if (db == NULL) {
215 *dbp = NULL;
216 return (SET_ERROR(EIO));
217 }
218
219 *dbp = &db->db;
220 return (err);
221 }
222
223 int
dmu_buf_hold_by_dnode(dnode_t * dn,uint64_t offset,const void * tag,dmu_buf_t ** dbp,int flags)224 dmu_buf_hold_by_dnode(dnode_t *dn, uint64_t offset,
225 const void *tag, dmu_buf_t **dbp, int flags)
226 {
227 int err;
228 int db_flags = DB_RF_CANFAIL;
229
230 if (flags & DMU_READ_NO_PREFETCH)
231 db_flags |= DB_RF_NOPREFETCH;
232 if (flags & DMU_READ_NO_DECRYPT)
233 db_flags |= DB_RF_NO_DECRYPT;
234
235 err = dmu_buf_hold_noread_by_dnode(dn, offset, tag, dbp);
236 if (err == 0) {
237 dmu_buf_impl_t *db = (dmu_buf_impl_t *)(*dbp);
238 err = dbuf_read(db, NULL, db_flags);
239 if (err != 0) {
240 dbuf_rele(db, tag);
241 *dbp = NULL;
242 }
243 }
244
245 return (err);
246 }
247
248 int
dmu_buf_hold(objset_t * os,uint64_t object,uint64_t offset,const void * tag,dmu_buf_t ** dbp,int flags)249 dmu_buf_hold(objset_t *os, uint64_t object, uint64_t offset,
250 const void *tag, dmu_buf_t **dbp, int flags)
251 {
252 int err;
253 int db_flags = DB_RF_CANFAIL;
254
255 if (flags & DMU_READ_NO_PREFETCH)
256 db_flags |= DB_RF_NOPREFETCH;
257 if (flags & DMU_READ_NO_DECRYPT)
258 db_flags |= DB_RF_NO_DECRYPT;
259
260 err = dmu_buf_hold_noread(os, object, offset, tag, dbp);
261 if (err == 0) {
262 dmu_buf_impl_t *db = (dmu_buf_impl_t *)(*dbp);
263 err = dbuf_read(db, NULL, db_flags);
264 if (err != 0) {
265 dbuf_rele(db, tag);
266 *dbp = NULL;
267 }
268 }
269
270 return (err);
271 }
272
273 int
dmu_bonus_max(void)274 dmu_bonus_max(void)
275 {
276 return (DN_OLD_MAX_BONUSLEN);
277 }
278
279 int
dmu_set_bonus(dmu_buf_t * db_fake,int newsize,dmu_tx_t * tx)280 dmu_set_bonus(dmu_buf_t *db_fake, int newsize, dmu_tx_t *tx)
281 {
282 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
283 dnode_t *dn;
284 int error;
285
286 if (newsize < 0 || newsize > db_fake->db_size)
287 return (SET_ERROR(EINVAL));
288
289 DB_DNODE_ENTER(db);
290 dn = DB_DNODE(db);
291
292 if (dn->dn_bonus != db) {
293 error = SET_ERROR(EINVAL);
294 } else {
295 dnode_setbonuslen(dn, newsize, tx);
296 error = 0;
297 }
298
299 DB_DNODE_EXIT(db);
300 return (error);
301 }
302
303 int
dmu_set_bonustype(dmu_buf_t * db_fake,dmu_object_type_t type,dmu_tx_t * tx)304 dmu_set_bonustype(dmu_buf_t *db_fake, dmu_object_type_t type, dmu_tx_t *tx)
305 {
306 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
307 dnode_t *dn;
308 int error;
309
310 if (!DMU_OT_IS_VALID(type))
311 return (SET_ERROR(EINVAL));
312
313 DB_DNODE_ENTER(db);
314 dn = DB_DNODE(db);
315
316 if (dn->dn_bonus != db) {
317 error = SET_ERROR(EINVAL);
318 } else {
319 dnode_setbonus_type(dn, type, tx);
320 error = 0;
321 }
322
323 DB_DNODE_EXIT(db);
324 return (error);
325 }
326
327 dmu_object_type_t
dmu_get_bonustype(dmu_buf_t * db_fake)328 dmu_get_bonustype(dmu_buf_t *db_fake)
329 {
330 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
331 dmu_object_type_t type;
332
333 DB_DNODE_ENTER(db);
334 type = DB_DNODE(db)->dn_bonustype;
335 DB_DNODE_EXIT(db);
336
337 return (type);
338 }
339
340 int
dmu_rm_spill(objset_t * os,uint64_t object,dmu_tx_t * tx)341 dmu_rm_spill(objset_t *os, uint64_t object, dmu_tx_t *tx)
342 {
343 dnode_t *dn;
344 int error;
345
346 error = dnode_hold(os, object, FTAG, &dn);
347 dbuf_rm_spill(dn, tx);
348 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
349 dnode_rm_spill(dn, tx);
350 rw_exit(&dn->dn_struct_rwlock);
351 dnode_rele(dn, FTAG);
352 return (error);
353 }
354
355 /*
356 * Lookup and hold the bonus buffer for the provided dnode. If the dnode
357 * has not yet been allocated a new bonus dbuf a will be allocated.
358 * Returns ENOENT, EIO, or 0.
359 */
dmu_bonus_hold_by_dnode(dnode_t * dn,const void * tag,dmu_buf_t ** dbp,uint32_t flags)360 int dmu_bonus_hold_by_dnode(dnode_t *dn, const void *tag, dmu_buf_t **dbp,
361 uint32_t flags)
362 {
363 dmu_buf_impl_t *db;
364 int error;
365 uint32_t db_flags = DB_RF_MUST_SUCCEED;
366
367 if (flags & DMU_READ_NO_PREFETCH)
368 db_flags |= DB_RF_NOPREFETCH;
369 if (flags & DMU_READ_NO_DECRYPT)
370 db_flags |= DB_RF_NO_DECRYPT;
371
372 rw_enter(&dn->dn_struct_rwlock, RW_READER);
373 if (dn->dn_bonus == NULL) {
374 if (!rw_tryupgrade(&dn->dn_struct_rwlock)) {
375 rw_exit(&dn->dn_struct_rwlock);
376 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
377 }
378 if (dn->dn_bonus == NULL)
379 dbuf_create_bonus(dn);
380 }
381 db = dn->dn_bonus;
382
383 /* as long as the bonus buf is held, the dnode will be held */
384 if (zfs_refcount_add(&db->db_holds, tag) == 1) {
385 VERIFY(dnode_add_ref(dn, db));
386 atomic_inc_32(&dn->dn_dbufs_count);
387 }
388
389 /*
390 * Wait to drop dn_struct_rwlock until after adding the bonus dbuf's
391 * hold and incrementing the dbuf count to ensure that dnode_move() sees
392 * a dnode hold for every dbuf.
393 */
394 rw_exit(&dn->dn_struct_rwlock);
395
396 error = dbuf_read(db, NULL, db_flags);
397 if (error) {
398 dnode_evict_bonus(dn);
399 dbuf_rele(db, tag);
400 *dbp = NULL;
401 return (error);
402 }
403
404 *dbp = &db->db;
405 return (0);
406 }
407
408 int
dmu_bonus_hold(objset_t * os,uint64_t object,const void * tag,dmu_buf_t ** dbp)409 dmu_bonus_hold(objset_t *os, uint64_t object, const void *tag, dmu_buf_t **dbp)
410 {
411 dnode_t *dn;
412 int error;
413
414 error = dnode_hold(os, object, FTAG, &dn);
415 if (error)
416 return (error);
417
418 error = dmu_bonus_hold_by_dnode(dn, tag, dbp, DMU_READ_NO_PREFETCH);
419 dnode_rele(dn, FTAG);
420
421 return (error);
422 }
423
424 /*
425 * returns ENOENT, EIO, or 0.
426 *
427 * This interface will allocate a blank spill dbuf when a spill blk
428 * doesn't already exist on the dnode.
429 *
430 * if you only want to find an already existing spill db, then
431 * dmu_spill_hold_existing() should be used.
432 */
433 int
dmu_spill_hold_by_dnode(dnode_t * dn,uint32_t flags,const void * tag,dmu_buf_t ** dbp)434 dmu_spill_hold_by_dnode(dnode_t *dn, uint32_t flags, const void *tag,
435 dmu_buf_t **dbp)
436 {
437 dmu_buf_impl_t *db = NULL;
438 int err;
439
440 if ((flags & DB_RF_HAVESTRUCT) == 0)
441 rw_enter(&dn->dn_struct_rwlock, RW_READER);
442
443 db = dbuf_hold(dn, DMU_SPILL_BLKID, tag);
444
445 if ((flags & DB_RF_HAVESTRUCT) == 0)
446 rw_exit(&dn->dn_struct_rwlock);
447
448 if (db == NULL) {
449 *dbp = NULL;
450 return (SET_ERROR(EIO));
451 }
452 err = dbuf_read(db, NULL, flags);
453 if (err == 0)
454 *dbp = &db->db;
455 else {
456 dbuf_rele(db, tag);
457 *dbp = NULL;
458 }
459 return (err);
460 }
461
462 int
dmu_spill_hold_existing(dmu_buf_t * bonus,const void * tag,dmu_buf_t ** dbp)463 dmu_spill_hold_existing(dmu_buf_t *bonus, const void *tag, dmu_buf_t **dbp)
464 {
465 dmu_buf_impl_t *db = (dmu_buf_impl_t *)bonus;
466 dnode_t *dn;
467 int err;
468
469 DB_DNODE_ENTER(db);
470 dn = DB_DNODE(db);
471
472 if (spa_version(dn->dn_objset->os_spa) < SPA_VERSION_SA) {
473 err = SET_ERROR(EINVAL);
474 } else {
475 rw_enter(&dn->dn_struct_rwlock, RW_READER);
476
477 if (!dn->dn_have_spill) {
478 err = SET_ERROR(ENOENT);
479 } else {
480 err = dmu_spill_hold_by_dnode(dn,
481 DB_RF_HAVESTRUCT | DB_RF_CANFAIL, tag, dbp);
482 }
483
484 rw_exit(&dn->dn_struct_rwlock);
485 }
486
487 DB_DNODE_EXIT(db);
488 return (err);
489 }
490
491 int
dmu_spill_hold_by_bonus(dmu_buf_t * bonus,uint32_t flags,const void * tag,dmu_buf_t ** dbp)492 dmu_spill_hold_by_bonus(dmu_buf_t *bonus, uint32_t flags, const void *tag,
493 dmu_buf_t **dbp)
494 {
495 dmu_buf_impl_t *db = (dmu_buf_impl_t *)bonus;
496 int err;
497 uint32_t db_flags = DB_RF_CANFAIL;
498
499 if (flags & DMU_READ_NO_DECRYPT)
500 db_flags |= DB_RF_NO_DECRYPT;
501
502 DB_DNODE_ENTER(db);
503 err = dmu_spill_hold_by_dnode(DB_DNODE(db), db_flags, tag, dbp);
504 DB_DNODE_EXIT(db);
505
506 return (err);
507 }
508
509 /*
510 * Note: longer-term, we should modify all of the dmu_buf_*() interfaces
511 * to take a held dnode rather than <os, object> -- the lookup is wasteful,
512 * and can induce severe lock contention when writing to several files
513 * whose dnodes are in the same block.
514 */
515 int
dmu_buf_hold_array_by_dnode(dnode_t * dn,uint64_t offset,uint64_t length,boolean_t read,const void * tag,int * numbufsp,dmu_buf_t *** dbpp,uint32_t flags)516 dmu_buf_hold_array_by_dnode(dnode_t *dn, uint64_t offset, uint64_t length,
517 boolean_t read, const void *tag, int *numbufsp, dmu_buf_t ***dbpp,
518 uint32_t flags)
519 {
520 dmu_buf_t **dbp;
521 zstream_t *zs = NULL;
522 uint64_t blkid, nblks, i;
523 uint32_t dbuf_flags;
524 int err;
525 zio_t *zio = NULL;
526 boolean_t missed = B_FALSE;
527
528 ASSERT(!read || length <= DMU_MAX_ACCESS);
529
530 /*
531 * Note: We directly notify the prefetch code of this read, so that
532 * we can tell it about the multi-block read. dbuf_read() only knows
533 * about the one block it is accessing.
534 */
535 dbuf_flags = DB_RF_CANFAIL | DB_RF_NEVERWAIT | DB_RF_HAVESTRUCT |
536 DB_RF_NOPREFETCH;
537
538 if ((flags & DMU_READ_NO_DECRYPT) != 0)
539 dbuf_flags |= DB_RF_NO_DECRYPT;
540
541 rw_enter(&dn->dn_struct_rwlock, RW_READER);
542 if (dn->dn_datablkshift) {
543 int blkshift = dn->dn_datablkshift;
544 nblks = (P2ROUNDUP(offset + length, 1ULL << blkshift) -
545 P2ALIGN_TYPED(offset, 1ULL << blkshift, uint64_t))
546 >> blkshift;
547 } else {
548 if (offset + length > dn->dn_datablksz) {
549 zfs_panic_recover("zfs: accessing past end of object "
550 "%llx/%llx (size=%u access=%llu+%llu)",
551 (longlong_t)dn->dn_objset->
552 os_dsl_dataset->ds_object,
553 (longlong_t)dn->dn_object, dn->dn_datablksz,
554 (longlong_t)offset, (longlong_t)length);
555 rw_exit(&dn->dn_struct_rwlock);
556 return (SET_ERROR(EIO));
557 }
558 nblks = 1;
559 }
560 dbp = kmem_zalloc(sizeof (dmu_buf_t *) * nblks, KM_SLEEP);
561
562 if (read)
563 zio = zio_root(dn->dn_objset->os_spa, NULL, NULL,
564 ZIO_FLAG_CANFAIL);
565 blkid = dbuf_whichblock(dn, 0, offset);
566 if ((flags & DMU_READ_NO_PREFETCH) == 0) {
567 /*
568 * Prepare the zfetch before initiating the demand reads, so
569 * that if multiple threads block on same indirect block, we
570 * base predictions on the original less racy request order.
571 */
572 zs = dmu_zfetch_prepare(&dn->dn_zfetch, blkid, nblks, read,
573 B_TRUE);
574 }
575 for (i = 0; i < nblks; i++) {
576 dmu_buf_impl_t *db = dbuf_hold(dn, blkid + i, tag);
577 if (db == NULL) {
578 if (zs) {
579 dmu_zfetch_run(&dn->dn_zfetch, zs, missed,
580 B_TRUE);
581 }
582 rw_exit(&dn->dn_struct_rwlock);
583 dmu_buf_rele_array(dbp, nblks, tag);
584 if (read)
585 zio_nowait(zio);
586 return (SET_ERROR(EIO));
587 }
588
589 /*
590 * Initiate async demand data read.
591 * We check the db_state after calling dbuf_read() because
592 * (1) dbuf_read() may change the state to CACHED due to a
593 * hit in the ARC, and (2) on a cache miss, a child will
594 * have been added to "zio" but not yet completed, so the
595 * state will not yet be CACHED.
596 */
597 if (read) {
598 if (i == nblks - 1 && blkid + i < dn->dn_maxblkid &&
599 offset + length < db->db.db_offset +
600 db->db.db_size) {
601 if (offset <= db->db.db_offset)
602 dbuf_flags |= DB_RF_PARTIAL_FIRST;
603 else
604 dbuf_flags |= DB_RF_PARTIAL_MORE;
605 }
606 (void) dbuf_read(db, zio, dbuf_flags);
607 if (db->db_state != DB_CACHED)
608 missed = B_TRUE;
609 }
610 dbp[i] = &db->db;
611 }
612
613 /*
614 * If we are doing O_DIRECT we still hold the dbufs, even for reads,
615 * but we do not issue any reads here. We do not want to account for
616 * writes in this case.
617 *
618 * O_DIRECT write/read accounting takes place in
619 * dmu_{write/read}_abd().
620 */
621 if (!read && ((flags & DMU_DIRECTIO) == 0))
622 zfs_racct_write(dn->dn_objset->os_spa, length, nblks, flags);
623
624 if (zs)
625 dmu_zfetch_run(&dn->dn_zfetch, zs, missed, B_TRUE);
626 rw_exit(&dn->dn_struct_rwlock);
627
628 if (read) {
629 /* wait for async read i/o */
630 err = zio_wait(zio);
631 if (err) {
632 dmu_buf_rele_array(dbp, nblks, tag);
633 return (err);
634 }
635
636 /* wait for other io to complete */
637 for (i = 0; i < nblks; i++) {
638 dmu_buf_impl_t *db = (dmu_buf_impl_t *)dbp[i];
639 mutex_enter(&db->db_mtx);
640 while (db->db_state == DB_READ ||
641 db->db_state == DB_FILL)
642 cv_wait(&db->db_changed, &db->db_mtx);
643 if (db->db_state == DB_UNCACHED)
644 err = SET_ERROR(EIO);
645 mutex_exit(&db->db_mtx);
646 if (err) {
647 dmu_buf_rele_array(dbp, nblks, tag);
648 return (err);
649 }
650 }
651 }
652
653 *numbufsp = nblks;
654 *dbpp = dbp;
655 return (0);
656 }
657
658 int
dmu_buf_hold_array(objset_t * os,uint64_t object,uint64_t offset,uint64_t length,int read,const void * tag,int * numbufsp,dmu_buf_t *** dbpp)659 dmu_buf_hold_array(objset_t *os, uint64_t object, uint64_t offset,
660 uint64_t length, int read, const void *tag, int *numbufsp,
661 dmu_buf_t ***dbpp)
662 {
663 dnode_t *dn;
664 int err;
665
666 err = dnode_hold(os, object, FTAG, &dn);
667 if (err)
668 return (err);
669
670 err = dmu_buf_hold_array_by_dnode(dn, offset, length, read, tag,
671 numbufsp, dbpp, DMU_READ_PREFETCH);
672
673 dnode_rele(dn, FTAG);
674
675 return (err);
676 }
677
678 int
dmu_buf_hold_array_by_bonus(dmu_buf_t * db_fake,uint64_t offset,uint64_t length,boolean_t read,const void * tag,int * numbufsp,dmu_buf_t *** dbpp)679 dmu_buf_hold_array_by_bonus(dmu_buf_t *db_fake, uint64_t offset,
680 uint64_t length, boolean_t read, const void *tag, int *numbufsp,
681 dmu_buf_t ***dbpp)
682 {
683 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
684 int err;
685
686 DB_DNODE_ENTER(db);
687 err = dmu_buf_hold_array_by_dnode(DB_DNODE(db), offset, length, read,
688 tag, numbufsp, dbpp, DMU_READ_PREFETCH);
689 DB_DNODE_EXIT(db);
690
691 return (err);
692 }
693
694 void
dmu_buf_rele_array(dmu_buf_t ** dbp_fake,int numbufs,const void * tag)695 dmu_buf_rele_array(dmu_buf_t **dbp_fake, int numbufs, const void *tag)
696 {
697 int i;
698 dmu_buf_impl_t **dbp = (dmu_buf_impl_t **)dbp_fake;
699
700 if (numbufs == 0)
701 return;
702
703 for (i = 0; i < numbufs; i++) {
704 if (dbp[i])
705 dbuf_rele(dbp[i], tag);
706 }
707
708 kmem_free(dbp, sizeof (dmu_buf_t *) * numbufs);
709 }
710
711 /*
712 * Issue prefetch I/Os for the given blocks. If level is greater than 0, the
713 * indirect blocks prefetched will be those that point to the blocks containing
714 * the data starting at offset, and continuing to offset + len. If the range
715 * is too long, prefetch the first dmu_prefetch_max bytes as requested, while
716 * for the rest only a higher level, also fitting within dmu_prefetch_max. It
717 * should primarily help random reads, since for long sequential reads there is
718 * a speculative prefetcher.
719 *
720 * Note that if the indirect blocks above the blocks being prefetched are not
721 * in cache, they will be asynchronously read in. Dnode read by dnode_hold()
722 * is currently synchronous.
723 */
724 void
dmu_prefetch(objset_t * os,uint64_t object,int64_t level,uint64_t offset,uint64_t len,zio_priority_t pri)725 dmu_prefetch(objset_t *os, uint64_t object, int64_t level, uint64_t offset,
726 uint64_t len, zio_priority_t pri)
727 {
728 dnode_t *dn;
729
730 if (dmu_prefetch_max == 0 || len == 0) {
731 dmu_prefetch_dnode(os, object, pri);
732 return;
733 }
734
735 if (dnode_hold(os, object, FTAG, &dn) != 0)
736 return;
737
738 dmu_prefetch_by_dnode(dn, level, offset, len, pri);
739
740 dnode_rele(dn, FTAG);
741 }
742
743 void
dmu_prefetch_by_dnode(dnode_t * dn,int64_t level,uint64_t offset,uint64_t len,zio_priority_t pri)744 dmu_prefetch_by_dnode(dnode_t *dn, int64_t level, uint64_t offset,
745 uint64_t len, zio_priority_t pri)
746 {
747 int64_t level2 = level;
748 uint64_t start, end, start2, end2;
749
750 /*
751 * Depending on len we may do two prefetches: blocks [start, end) at
752 * level, and following blocks [start2, end2) at higher level2.
753 */
754 rw_enter(&dn->dn_struct_rwlock, RW_READER);
755 if (dn->dn_datablkshift != 0) {
756 /*
757 * The object has multiple blocks. Calculate the full range
758 * of blocks [start, end2) and then split it into two parts,
759 * so that the first [start, end) fits into dmu_prefetch_max.
760 */
761 start = dbuf_whichblock(dn, level, offset);
762 end2 = dbuf_whichblock(dn, level, offset + len - 1) + 1;
763 uint8_t ibs = dn->dn_indblkshift;
764 uint8_t bs = (level == 0) ? dn->dn_datablkshift : ibs;
765 uint_t limit = P2ROUNDUP(dmu_prefetch_max, 1 << bs) >> bs;
766 start2 = end = MIN(end2, start + limit);
767
768 /*
769 * Find level2 where [start2, end2) fits into dmu_prefetch_max.
770 */
771 uint8_t ibps = ibs - SPA_BLKPTRSHIFT;
772 limit = P2ROUNDUP(dmu_prefetch_max, 1 << ibs) >> ibs;
773 do {
774 level2++;
775 start2 = P2ROUNDUP(start2, 1 << ibps) >> ibps;
776 end2 = P2ROUNDUP(end2, 1 << ibps) >> ibps;
777 } while (end2 - start2 > limit);
778 } else {
779 /* There is only one block. Prefetch it or nothing. */
780 start = start2 = end2 = 0;
781 end = start + (level == 0 && offset < dn->dn_datablksz);
782 }
783
784 for (uint64_t i = start; i < end; i++)
785 dbuf_prefetch(dn, level, i, pri, 0);
786 for (uint64_t i = start2; i < end2; i++)
787 dbuf_prefetch(dn, level2, i, pri, 0);
788 rw_exit(&dn->dn_struct_rwlock);
789 }
790
791 typedef struct {
792 kmutex_t dpa_lock;
793 kcondvar_t dpa_cv;
794 uint64_t dpa_pending_io;
795 } dmu_prefetch_arg_t;
796
797 static void
dmu_prefetch_done(void * arg,uint64_t level,uint64_t blkid,boolean_t issued)798 dmu_prefetch_done(void *arg, uint64_t level, uint64_t blkid, boolean_t issued)
799 {
800 (void) level; (void) blkid; (void)issued;
801 dmu_prefetch_arg_t *dpa = arg;
802
803 ASSERT0(level);
804
805 mutex_enter(&dpa->dpa_lock);
806 ASSERT3U(dpa->dpa_pending_io, >, 0);
807 if (--dpa->dpa_pending_io == 0)
808 cv_broadcast(&dpa->dpa_cv);
809 mutex_exit(&dpa->dpa_lock);
810 }
811
812 static void
dmu_prefetch_wait_by_dnode(dnode_t * dn,uint64_t offset,uint64_t len)813 dmu_prefetch_wait_by_dnode(dnode_t *dn, uint64_t offset, uint64_t len)
814 {
815 dmu_prefetch_arg_t dpa;
816
817 mutex_init(&dpa.dpa_lock, NULL, MUTEX_DEFAULT, NULL);
818 cv_init(&dpa.dpa_cv, NULL, CV_DEFAULT, NULL);
819
820 rw_enter(&dn->dn_struct_rwlock, RW_READER);
821
822 uint64_t start = dbuf_whichblock(dn, 0, offset);
823 uint64_t end = dbuf_whichblock(dn, 0, offset + len - 1) + 1;
824 dpa.dpa_pending_io = end - start;
825
826 for (uint64_t blk = start; blk < end; blk++) {
827 (void) dbuf_prefetch_impl(dn, 0, blk, ZIO_PRIORITY_ASYNC_READ,
828 0, dmu_prefetch_done, &dpa);
829 }
830
831 rw_exit(&dn->dn_struct_rwlock);
832
833 /* wait for prefetch L0 reads to finish */
834 mutex_enter(&dpa.dpa_lock);
835 while (dpa.dpa_pending_io > 0) {
836 cv_wait(&dpa.dpa_cv, &dpa.dpa_lock);
837
838 }
839 mutex_exit(&dpa.dpa_lock);
840
841 mutex_destroy(&dpa.dpa_lock);
842 cv_destroy(&dpa.dpa_cv);
843 }
844
845 /*
846 * Issue prefetch I/Os for the given L0 block range and wait for the I/O
847 * to complete. This does not enforce dmu_prefetch_max and will prefetch
848 * the entire range. The blocks are read from disk into the ARC but no
849 * decompression occurs (i.e., the dbuf cache is not required).
850 */
851 int
dmu_prefetch_wait(objset_t * os,uint64_t object,uint64_t offset,uint64_t size)852 dmu_prefetch_wait(objset_t *os, uint64_t object, uint64_t offset, uint64_t size)
853 {
854 dnode_t *dn;
855 int err = 0;
856
857 err = dnode_hold(os, object, FTAG, &dn);
858 if (err != 0)
859 return (err);
860
861 /*
862 * Chunk the requests (16 indirects worth) so that we can be interrupted
863 */
864 uint64_t chunksize;
865 if (dn->dn_indblkshift) {
866 uint64_t nbps = bp_span_in_blocks(dn->dn_indblkshift, 1);
867 chunksize = (nbps * 16) << dn->dn_datablkshift;
868 } else {
869 chunksize = dn->dn_datablksz;
870 }
871
872 while (size > 0) {
873 uint64_t mylen = MIN(size, chunksize);
874
875 dmu_prefetch_wait_by_dnode(dn, offset, mylen);
876
877 offset += mylen;
878 size -= mylen;
879
880 if (issig()) {
881 err = SET_ERROR(EINTR);
882 break;
883 }
884 }
885
886 dnode_rele(dn, FTAG);
887
888 return (err);
889 }
890
891 /*
892 * Issue prefetch I/Os for the given object's dnode.
893 */
894 void
dmu_prefetch_dnode(objset_t * os,uint64_t object,zio_priority_t pri)895 dmu_prefetch_dnode(objset_t *os, uint64_t object, zio_priority_t pri)
896 {
897 if (object == 0 || object >= DN_MAX_OBJECT)
898 return;
899
900 dnode_t *dn = DMU_META_DNODE(os);
901 rw_enter(&dn->dn_struct_rwlock, RW_READER);
902 uint64_t blkid = dbuf_whichblock(dn, 0, object * sizeof (dnode_phys_t));
903 dbuf_prefetch(dn, 0, blkid, pri, 0);
904 rw_exit(&dn->dn_struct_rwlock);
905 }
906
907 /*
908 * Get the next "chunk" of file data to free. We traverse the file from
909 * the end so that the file gets shorter over time (if we crash in the
910 * middle, this will leave us in a better state). We find allocated file
911 * data by simply searching the allocated level 1 indirects.
912 *
913 * On input, *start should be the first offset that does not need to be
914 * freed (e.g. "offset + length"). On return, *start will be the first
915 * offset that should be freed and l1blks is set to the number of level 1
916 * indirect blocks found within the chunk.
917 */
918 static int
get_next_chunk(dnode_t * dn,uint64_t * start,uint64_t minimum,uint64_t * l1blks)919 get_next_chunk(dnode_t *dn, uint64_t *start, uint64_t minimum, uint64_t *l1blks)
920 {
921 uint64_t blks;
922 uint64_t maxblks = DMU_MAX_ACCESS >> (dn->dn_indblkshift + 1);
923 /* bytes of data covered by a level-1 indirect block */
924 uint64_t iblkrange = (uint64_t)dn->dn_datablksz *
925 EPB(dn->dn_indblkshift, SPA_BLKPTRSHIFT);
926
927 ASSERT3U(minimum, <=, *start);
928
929 /* dn_nlevels == 1 means we don't have any L1 blocks */
930 if (dn->dn_nlevels <= 1) {
931 *l1blks = 0;
932 *start = minimum;
933 return (0);
934 }
935
936 /*
937 * Check if we can free the entire range assuming that all of the
938 * L1 blocks in this range have data. If we can, we use this
939 * worst case value as an estimate so we can avoid having to look
940 * at the object's actual data.
941 */
942 uint64_t total_l1blks =
943 (roundup(*start, iblkrange) - (minimum / iblkrange * iblkrange)) /
944 iblkrange;
945 if (total_l1blks <= maxblks) {
946 *l1blks = total_l1blks;
947 *start = minimum;
948 return (0);
949 }
950 ASSERT(ISP2(iblkrange));
951
952 for (blks = 0; *start > minimum && blks < maxblks; blks++) {
953 int err;
954
955 /*
956 * dnode_next_offset(BACKWARDS) will find an allocated L1
957 * indirect block at or before the input offset. We must
958 * decrement *start so that it is at the end of the region
959 * to search.
960 */
961 (*start)--;
962
963 err = dnode_next_offset(dn,
964 DNODE_FIND_BACKWARDS, start, 2, 1, 0);
965
966 /* if there are no indirect blocks before start, we are done */
967 if (err == ESRCH) {
968 *start = minimum;
969 break;
970 } else if (err != 0) {
971 *l1blks = blks;
972 return (err);
973 }
974
975 /* set start to the beginning of this L1 indirect */
976 *start = P2ALIGN_TYPED(*start, iblkrange, uint64_t);
977 }
978 if (*start < minimum)
979 *start = minimum;
980 *l1blks = blks;
981
982 return (0);
983 }
984
985 /*
986 * If this objset is of type OST_ZFS return true if vfs's unmounted flag is set,
987 * otherwise return false.
988 * Used below in dmu_free_long_range_impl() to enable abort when unmounting
989 */
990 static boolean_t
dmu_objset_zfs_unmounting(objset_t * os)991 dmu_objset_zfs_unmounting(objset_t *os)
992 {
993 #ifdef _KERNEL
994 if (dmu_objset_type(os) == DMU_OST_ZFS)
995 return (zfs_get_vfs_flag_unmounted(os));
996 #else
997 (void) os;
998 #endif
999 return (B_FALSE);
1000 }
1001
1002 static int
dmu_free_long_range_impl(objset_t * os,dnode_t * dn,uint64_t offset,uint64_t length)1003 dmu_free_long_range_impl(objset_t *os, dnode_t *dn, uint64_t offset,
1004 uint64_t length)
1005 {
1006 uint64_t object_size;
1007 int err;
1008 uint64_t dirty_frees_threshold;
1009 dsl_pool_t *dp = dmu_objset_pool(os);
1010
1011 if (dn == NULL)
1012 return (SET_ERROR(EINVAL));
1013
1014 object_size = (dn->dn_maxblkid + 1) * dn->dn_datablksz;
1015 if (offset >= object_size)
1016 return (0);
1017
1018 if (zfs_per_txg_dirty_frees_percent <= 100)
1019 dirty_frees_threshold =
1020 zfs_per_txg_dirty_frees_percent * zfs_dirty_data_max / 100;
1021 else
1022 dirty_frees_threshold = zfs_dirty_data_max / 20;
1023
1024 if (length == DMU_OBJECT_END || offset + length > object_size)
1025 length = object_size - offset;
1026
1027 while (length != 0) {
1028 uint64_t chunk_end, chunk_begin, chunk_len;
1029 uint64_t l1blks;
1030 dmu_tx_t *tx;
1031
1032 if (dmu_objset_zfs_unmounting(dn->dn_objset))
1033 return (SET_ERROR(EINTR));
1034
1035 chunk_end = chunk_begin = offset + length;
1036
1037 /* move chunk_begin backwards to the beginning of this chunk */
1038 err = get_next_chunk(dn, &chunk_begin, offset, &l1blks);
1039 if (err)
1040 return (err);
1041 ASSERT3U(chunk_begin, >=, offset);
1042 ASSERT3U(chunk_begin, <=, chunk_end);
1043
1044 chunk_len = chunk_end - chunk_begin;
1045
1046 tx = dmu_tx_create(os);
1047 dmu_tx_hold_free(tx, dn->dn_object, chunk_begin, chunk_len);
1048
1049 /*
1050 * Mark this transaction as typically resulting in a net
1051 * reduction in space used.
1052 */
1053 dmu_tx_mark_netfree(tx);
1054 err = dmu_tx_assign(tx, DMU_TX_WAIT);
1055 if (err) {
1056 dmu_tx_abort(tx);
1057 return (err);
1058 }
1059
1060 uint64_t txg = dmu_tx_get_txg(tx);
1061
1062 mutex_enter(&dp->dp_lock);
1063 uint64_t long_free_dirty =
1064 dp->dp_long_free_dirty_pertxg[txg & TXG_MASK];
1065 mutex_exit(&dp->dp_lock);
1066
1067 /*
1068 * To avoid filling up a TXG with just frees, wait for
1069 * the next TXG to open before freeing more chunks if
1070 * we have reached the threshold of frees.
1071 */
1072 if (dirty_frees_threshold != 0 &&
1073 long_free_dirty >= dirty_frees_threshold) {
1074 DMU_TX_STAT_BUMP(dmu_tx_dirty_frees_delay);
1075 dmu_tx_commit(tx);
1076 txg_wait_open(dp, 0, B_TRUE);
1077 continue;
1078 }
1079
1080 /*
1081 * In order to prevent unnecessary write throttling, for each
1082 * TXG, we track the cumulative size of L1 blocks being dirtied
1083 * in dnode_free_range() below. We compare this number to a
1084 * tunable threshold, past which we prevent new L1 dirty freeing
1085 * blocks from being added into the open TXG. See
1086 * dmu_free_long_range_impl() for details. The threshold
1087 * prevents write throttle activation due to dirty freeing L1
1088 * blocks taking up a large percentage of zfs_dirty_data_max.
1089 */
1090 mutex_enter(&dp->dp_lock);
1091 dp->dp_long_free_dirty_pertxg[txg & TXG_MASK] +=
1092 l1blks << dn->dn_indblkshift;
1093 mutex_exit(&dp->dp_lock);
1094 DTRACE_PROBE3(free__long__range,
1095 uint64_t, long_free_dirty, uint64_t, chunk_len,
1096 uint64_t, txg);
1097 dnode_free_range(dn, chunk_begin, chunk_len, tx);
1098
1099 dmu_tx_commit(tx);
1100
1101 length -= chunk_len;
1102 }
1103 return (0);
1104 }
1105
1106 int
dmu_free_long_range(objset_t * os,uint64_t object,uint64_t offset,uint64_t length)1107 dmu_free_long_range(objset_t *os, uint64_t object,
1108 uint64_t offset, uint64_t length)
1109 {
1110 dnode_t *dn;
1111 int err;
1112
1113 err = dnode_hold(os, object, FTAG, &dn);
1114 if (err != 0)
1115 return (err);
1116 err = dmu_free_long_range_impl(os, dn, offset, length);
1117
1118 /*
1119 * It is important to zero out the maxblkid when freeing the entire
1120 * file, so that (a) subsequent calls to dmu_free_long_range_impl()
1121 * will take the fast path, and (b) dnode_reallocate() can verify
1122 * that the entire file has been freed.
1123 */
1124 if (err == 0 && offset == 0 && length == DMU_OBJECT_END)
1125 dn->dn_maxblkid = 0;
1126
1127 dnode_rele(dn, FTAG);
1128 return (err);
1129 }
1130
1131 int
dmu_free_long_object(objset_t * os,uint64_t object)1132 dmu_free_long_object(objset_t *os, uint64_t object)
1133 {
1134 dmu_tx_t *tx;
1135 int err;
1136
1137 err = dmu_free_long_range(os, object, 0, DMU_OBJECT_END);
1138 if (err != 0)
1139 return (err);
1140
1141 tx = dmu_tx_create(os);
1142 dmu_tx_hold_bonus(tx, object);
1143 dmu_tx_hold_free(tx, object, 0, DMU_OBJECT_END);
1144 dmu_tx_mark_netfree(tx);
1145 err = dmu_tx_assign(tx, DMU_TX_WAIT);
1146 if (err == 0) {
1147 err = dmu_object_free(os, object, tx);
1148 dmu_tx_commit(tx);
1149 } else {
1150 dmu_tx_abort(tx);
1151 }
1152
1153 return (err);
1154 }
1155
1156 int
dmu_free_range(objset_t * os,uint64_t object,uint64_t offset,uint64_t size,dmu_tx_t * tx)1157 dmu_free_range(objset_t *os, uint64_t object, uint64_t offset,
1158 uint64_t size, dmu_tx_t *tx)
1159 {
1160 dnode_t *dn;
1161 int err = dnode_hold(os, object, FTAG, &dn);
1162 if (err)
1163 return (err);
1164 ASSERT(offset < UINT64_MAX);
1165 ASSERT(size == DMU_OBJECT_END || size <= UINT64_MAX - offset);
1166 dnode_free_range(dn, offset, size, tx);
1167 dnode_rele(dn, FTAG);
1168 return (0);
1169 }
1170
1171 static int
dmu_read_impl(dnode_t * dn,uint64_t offset,uint64_t size,void * buf,uint32_t flags)1172 dmu_read_impl(dnode_t *dn, uint64_t offset, uint64_t size,
1173 void *buf, uint32_t flags)
1174 {
1175 dmu_buf_t **dbp;
1176 int numbufs, err = 0;
1177
1178 /*
1179 * Deal with odd block sizes, where there can't be data past the first
1180 * block. If we ever do the tail block optimization, we will need to
1181 * handle that here as well.
1182 */
1183 if (dn->dn_maxblkid == 0) {
1184 uint64_t newsz = offset > dn->dn_datablksz ? 0 :
1185 MIN(size, dn->dn_datablksz - offset);
1186 memset((char *)buf + newsz, 0, size - newsz);
1187 size = newsz;
1188 }
1189
1190 if (size == 0)
1191 return (0);
1192
1193 /* Allow Direct I/O when requested and properly aligned */
1194 if ((flags & DMU_DIRECTIO) && zfs_dio_page_aligned(buf) &&
1195 zfs_dio_aligned(offset, size, PAGESIZE)) {
1196 abd_t *data = abd_get_from_buf(buf, size);
1197 err = dmu_read_abd(dn, offset, size, data, flags);
1198 abd_free(data);
1199 return (err);
1200 }
1201
1202 while (size > 0) {
1203 uint64_t mylen = MIN(size, DMU_MAX_ACCESS / 2);
1204 int i;
1205
1206 /*
1207 * NB: we could do this block-at-a-time, but it's nice
1208 * to be reading in parallel.
1209 */
1210 err = dmu_buf_hold_array_by_dnode(dn, offset, mylen,
1211 TRUE, FTAG, &numbufs, &dbp, flags);
1212 if (err)
1213 break;
1214
1215 for (i = 0; i < numbufs; i++) {
1216 uint64_t tocpy;
1217 int64_t bufoff;
1218 dmu_buf_t *db = dbp[i];
1219
1220 ASSERT(size > 0);
1221
1222 bufoff = offset - db->db_offset;
1223 tocpy = MIN(db->db_size - bufoff, size);
1224
1225 ASSERT(db->db_data != NULL);
1226 (void) memcpy(buf, (char *)db->db_data + bufoff, tocpy);
1227
1228 offset += tocpy;
1229 size -= tocpy;
1230 buf = (char *)buf + tocpy;
1231 }
1232 dmu_buf_rele_array(dbp, numbufs, FTAG);
1233 }
1234 return (err);
1235 }
1236
1237 int
dmu_read(objset_t * os,uint64_t object,uint64_t offset,uint64_t size,void * buf,uint32_t flags)1238 dmu_read(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
1239 void *buf, uint32_t flags)
1240 {
1241 dnode_t *dn;
1242 int err;
1243
1244 err = dnode_hold(os, object, FTAG, &dn);
1245 if (err != 0)
1246 return (err);
1247
1248 err = dmu_read_impl(dn, offset, size, buf, flags);
1249 dnode_rele(dn, FTAG);
1250 return (err);
1251 }
1252
1253 int
dmu_read_by_dnode(dnode_t * dn,uint64_t offset,uint64_t size,void * buf,uint32_t flags)1254 dmu_read_by_dnode(dnode_t *dn, uint64_t offset, uint64_t size, void *buf,
1255 uint32_t flags)
1256 {
1257 return (dmu_read_impl(dn, offset, size, buf, flags));
1258 }
1259
1260 static void
dmu_write_impl(dmu_buf_t ** dbp,int numbufs,uint64_t offset,uint64_t size,const void * buf,dmu_tx_t * tx)1261 dmu_write_impl(dmu_buf_t **dbp, int numbufs, uint64_t offset, uint64_t size,
1262 const void *buf, dmu_tx_t *tx)
1263 {
1264 int i;
1265
1266 for (i = 0; i < numbufs; i++) {
1267 uint64_t tocpy;
1268 int64_t bufoff;
1269 dmu_buf_t *db = dbp[i];
1270
1271 ASSERT(size > 0);
1272
1273 bufoff = offset - db->db_offset;
1274 tocpy = MIN(db->db_size - bufoff, size);
1275
1276 ASSERT(i == 0 || i == numbufs-1 || tocpy == db->db_size);
1277
1278 if (tocpy == db->db_size)
1279 dmu_buf_will_fill(db, tx, B_FALSE);
1280 else
1281 dmu_buf_will_dirty(db, tx);
1282
1283 ASSERT(db->db_data != NULL);
1284 (void) memcpy((char *)db->db_data + bufoff, buf, tocpy);
1285
1286 if (tocpy == db->db_size)
1287 dmu_buf_fill_done(db, tx, B_FALSE);
1288
1289 offset += tocpy;
1290 size -= tocpy;
1291 buf = (char *)buf + tocpy;
1292 }
1293 }
1294
1295 void
dmu_write(objset_t * os,uint64_t object,uint64_t offset,uint64_t size,const void * buf,dmu_tx_t * tx)1296 dmu_write(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
1297 const void *buf, dmu_tx_t *tx)
1298 {
1299 dmu_buf_t **dbp;
1300 int numbufs;
1301
1302 if (size == 0)
1303 return;
1304
1305 VERIFY0(dmu_buf_hold_array(os, object, offset, size,
1306 FALSE, FTAG, &numbufs, &dbp));
1307 dmu_write_impl(dbp, numbufs, offset, size, buf, tx);
1308 dmu_buf_rele_array(dbp, numbufs, FTAG);
1309 }
1310
1311 /*
1312 * This interface is not used internally by ZFS but is provided for
1313 * use by Lustre which is built on the DMU interfaces.
1314 */
1315 int
dmu_write_by_dnode_flags(dnode_t * dn,uint64_t offset,uint64_t size,const void * buf,dmu_tx_t * tx,uint32_t flags)1316 dmu_write_by_dnode_flags(dnode_t *dn, uint64_t offset, uint64_t size,
1317 const void *buf, dmu_tx_t *tx, uint32_t flags)
1318 {
1319 dmu_buf_t **dbp;
1320 int numbufs;
1321 int error;
1322
1323 if (size == 0)
1324 return (0);
1325
1326 /* Allow Direct I/O when requested and properly aligned */
1327 if ((flags & DMU_DIRECTIO) && zfs_dio_page_aligned((void *)buf) &&
1328 zfs_dio_aligned(offset, size, dn->dn_datablksz)) {
1329 abd_t *data = abd_get_from_buf((void *)buf, size);
1330 error = dmu_write_abd(dn, offset, size, data, DMU_DIRECTIO, tx);
1331 abd_free(data);
1332 return (error);
1333 }
1334
1335 VERIFY0(dmu_buf_hold_array_by_dnode(dn, offset, size,
1336 FALSE, FTAG, &numbufs, &dbp, DMU_READ_PREFETCH));
1337 dmu_write_impl(dbp, numbufs, offset, size, buf, tx);
1338 dmu_buf_rele_array(dbp, numbufs, FTAG);
1339 return (0);
1340 }
1341
1342 int
dmu_write_by_dnode(dnode_t * dn,uint64_t offset,uint64_t size,const void * buf,dmu_tx_t * tx)1343 dmu_write_by_dnode(dnode_t *dn, uint64_t offset, uint64_t size,
1344 const void *buf, dmu_tx_t *tx)
1345 {
1346 return (dmu_write_by_dnode_flags(dn, offset, size, buf, tx, 0));
1347 }
1348
1349 void
dmu_prealloc(objset_t * os,uint64_t object,uint64_t offset,uint64_t size,dmu_tx_t * tx)1350 dmu_prealloc(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
1351 dmu_tx_t *tx)
1352 {
1353 dmu_buf_t **dbp;
1354 int numbufs, i;
1355
1356 if (size == 0)
1357 return;
1358
1359 VERIFY(0 == dmu_buf_hold_array(os, object, offset, size,
1360 FALSE, FTAG, &numbufs, &dbp));
1361
1362 for (i = 0; i < numbufs; i++) {
1363 dmu_buf_t *db = dbp[i];
1364
1365 dmu_buf_will_not_fill(db, tx);
1366 }
1367 dmu_buf_rele_array(dbp, numbufs, FTAG);
1368 }
1369
1370 void
dmu_write_embedded(objset_t * os,uint64_t object,uint64_t offset,void * data,uint8_t etype,uint8_t comp,int uncompressed_size,int compressed_size,int byteorder,dmu_tx_t * tx)1371 dmu_write_embedded(objset_t *os, uint64_t object, uint64_t offset,
1372 void *data, uint8_t etype, uint8_t comp, int uncompressed_size,
1373 int compressed_size, int byteorder, dmu_tx_t *tx)
1374 {
1375 dmu_buf_t *db;
1376
1377 ASSERT3U(etype, <, NUM_BP_EMBEDDED_TYPES);
1378 ASSERT3U(comp, <, ZIO_COMPRESS_FUNCTIONS);
1379 VERIFY0(dmu_buf_hold_noread(os, object, offset,
1380 FTAG, &db));
1381
1382 dmu_buf_write_embedded(db,
1383 data, (bp_embedded_type_t)etype, (enum zio_compress)comp,
1384 uncompressed_size, compressed_size, byteorder, tx);
1385
1386 dmu_buf_rele(db, FTAG);
1387 }
1388
1389 void
dmu_redact(objset_t * os,uint64_t object,uint64_t offset,uint64_t size,dmu_tx_t * tx)1390 dmu_redact(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
1391 dmu_tx_t *tx)
1392 {
1393 int numbufs, i;
1394 dmu_buf_t **dbp;
1395
1396 VERIFY0(dmu_buf_hold_array(os, object, offset, size, FALSE, FTAG,
1397 &numbufs, &dbp));
1398 for (i = 0; i < numbufs; i++)
1399 dmu_buf_redact(dbp[i], tx);
1400 dmu_buf_rele_array(dbp, numbufs, FTAG);
1401 }
1402
1403 #ifdef _KERNEL
1404 int
dmu_read_uio_dnode(dnode_t * dn,zfs_uio_t * uio,uint64_t size)1405 dmu_read_uio_dnode(dnode_t *dn, zfs_uio_t *uio, uint64_t size)
1406 {
1407 dmu_buf_t **dbp;
1408 int numbufs, i, err;
1409
1410 if (uio->uio_extflg & UIO_DIRECT)
1411 return (dmu_read_uio_direct(dn, uio, size));
1412
1413 /*
1414 * NB: we could do this block-at-a-time, but it's nice
1415 * to be reading in parallel.
1416 */
1417 err = dmu_buf_hold_array_by_dnode(dn, zfs_uio_offset(uio), size,
1418 TRUE, FTAG, &numbufs, &dbp, 0);
1419 if (err)
1420 return (err);
1421
1422 for (i = 0; i < numbufs; i++) {
1423 uint64_t tocpy;
1424 int64_t bufoff;
1425 dmu_buf_t *db = dbp[i];
1426
1427 ASSERT(size > 0);
1428
1429 bufoff = zfs_uio_offset(uio) - db->db_offset;
1430 tocpy = MIN(db->db_size - bufoff, size);
1431
1432 ASSERT(db->db_data != NULL);
1433 err = zfs_uio_fault_move((char *)db->db_data + bufoff, tocpy,
1434 UIO_READ, uio);
1435
1436 if (err)
1437 break;
1438
1439 size -= tocpy;
1440 }
1441 dmu_buf_rele_array(dbp, numbufs, FTAG);
1442
1443 return (err);
1444 }
1445
1446 /*
1447 * Read 'size' bytes into the uio buffer.
1448 * From object zdb->db_object.
1449 * Starting at zfs_uio_offset(uio).
1450 *
1451 * If the caller already has a dbuf in the target object
1452 * (e.g. its bonus buffer), this routine is faster than dmu_read_uio(),
1453 * because we don't have to find the dnode_t for the object.
1454 */
1455 int
dmu_read_uio_dbuf(dmu_buf_t * zdb,zfs_uio_t * uio,uint64_t size)1456 dmu_read_uio_dbuf(dmu_buf_t *zdb, zfs_uio_t *uio, uint64_t size)
1457 {
1458 dmu_buf_impl_t *db = (dmu_buf_impl_t *)zdb;
1459 int err;
1460
1461 if (size == 0)
1462 return (0);
1463
1464 DB_DNODE_ENTER(db);
1465 err = dmu_read_uio_dnode(DB_DNODE(db), uio, size);
1466 DB_DNODE_EXIT(db);
1467
1468 return (err);
1469 }
1470
1471 /*
1472 * Read 'size' bytes into the uio buffer.
1473 * From the specified object
1474 * Starting at offset zfs_uio_offset(uio).
1475 */
1476 int
dmu_read_uio(objset_t * os,uint64_t object,zfs_uio_t * uio,uint64_t size)1477 dmu_read_uio(objset_t *os, uint64_t object, zfs_uio_t *uio, uint64_t size)
1478 {
1479 dnode_t *dn;
1480 int err;
1481
1482 if (size == 0)
1483 return (0);
1484
1485 err = dnode_hold(os, object, FTAG, &dn);
1486 if (err)
1487 return (err);
1488
1489 err = dmu_read_uio_dnode(dn, uio, size);
1490
1491 dnode_rele(dn, FTAG);
1492
1493 return (err);
1494 }
1495
1496 int
dmu_write_uio_dnode(dnode_t * dn,zfs_uio_t * uio,uint64_t size,dmu_tx_t * tx)1497 dmu_write_uio_dnode(dnode_t *dn, zfs_uio_t *uio, uint64_t size, dmu_tx_t *tx)
1498 {
1499 dmu_buf_t **dbp;
1500 int numbufs;
1501 int err = 0;
1502 uint64_t write_size;
1503
1504 top:
1505 write_size = size;
1506
1507 /*
1508 * We only allow Direct I/O writes to happen if we are block
1509 * sized aligned. Otherwise, we pass the write off to the ARC.
1510 */
1511 if ((uio->uio_extflg & UIO_DIRECT) &&
1512 (write_size >= dn->dn_datablksz)) {
1513 if (zfs_dio_aligned(zfs_uio_offset(uio), write_size,
1514 dn->dn_datablksz)) {
1515 return (dmu_write_uio_direct(dn, uio, size, tx));
1516 } else if (write_size > dn->dn_datablksz &&
1517 zfs_dio_offset_aligned(zfs_uio_offset(uio),
1518 dn->dn_datablksz)) {
1519 write_size =
1520 dn->dn_datablksz * (write_size / dn->dn_datablksz);
1521 err = dmu_write_uio_direct(dn, uio, write_size, tx);
1522 if (err == 0) {
1523 size -= write_size;
1524 goto top;
1525 } else {
1526 return (err);
1527 }
1528 } else {
1529 write_size =
1530 P2PHASE(zfs_uio_offset(uio), dn->dn_datablksz);
1531 }
1532 }
1533
1534 err = dmu_buf_hold_array_by_dnode(dn, zfs_uio_offset(uio), write_size,
1535 FALSE, FTAG, &numbufs, &dbp, DMU_READ_PREFETCH);
1536 if (err)
1537 return (err);
1538
1539 for (int i = 0; i < numbufs; i++) {
1540 uint64_t tocpy;
1541 int64_t bufoff;
1542 dmu_buf_t *db = dbp[i];
1543
1544 ASSERT(write_size > 0);
1545
1546 offset_t off = zfs_uio_offset(uio);
1547 bufoff = off - db->db_offset;
1548 tocpy = MIN(db->db_size - bufoff, write_size);
1549
1550 ASSERT(i == 0 || i == numbufs-1 || tocpy == db->db_size);
1551
1552 if (tocpy == db->db_size)
1553 dmu_buf_will_fill(db, tx, B_TRUE);
1554 else
1555 dmu_buf_will_dirty(db, tx);
1556
1557 ASSERT(db->db_data != NULL);
1558 err = zfs_uio_fault_move((char *)db->db_data + bufoff,
1559 tocpy, UIO_WRITE, uio);
1560
1561 if (tocpy == db->db_size && dmu_buf_fill_done(db, tx, err)) {
1562 /* The fill was reverted. Undo any uio progress. */
1563 zfs_uio_advance(uio, off - zfs_uio_offset(uio));
1564 }
1565
1566 if (err)
1567 break;
1568
1569 write_size -= tocpy;
1570 size -= tocpy;
1571 }
1572
1573 IMPLY(err == 0, write_size == 0);
1574
1575 dmu_buf_rele_array(dbp, numbufs, FTAG);
1576
1577 if ((uio->uio_extflg & UIO_DIRECT) && size > 0) {
1578 goto top;
1579 }
1580
1581 return (err);
1582 }
1583
1584 /*
1585 * Write 'size' bytes from the uio buffer.
1586 * To object zdb->db_object.
1587 * Starting at offset zfs_uio_offset(uio).
1588 *
1589 * If the caller already has a dbuf in the target object
1590 * (e.g. its bonus buffer), this routine is faster than dmu_write_uio(),
1591 * because we don't have to find the dnode_t for the object.
1592 */
1593 int
dmu_write_uio_dbuf(dmu_buf_t * zdb,zfs_uio_t * uio,uint64_t size,dmu_tx_t * tx)1594 dmu_write_uio_dbuf(dmu_buf_t *zdb, zfs_uio_t *uio, uint64_t size,
1595 dmu_tx_t *tx)
1596 {
1597 dmu_buf_impl_t *db = (dmu_buf_impl_t *)zdb;
1598 int err;
1599
1600 if (size == 0)
1601 return (0);
1602
1603 DB_DNODE_ENTER(db);
1604 err = dmu_write_uio_dnode(DB_DNODE(db), uio, size, tx);
1605 DB_DNODE_EXIT(db);
1606
1607 return (err);
1608 }
1609
1610 /*
1611 * Write 'size' bytes from the uio buffer.
1612 * To the specified object.
1613 * Starting at offset zfs_uio_offset(uio).
1614 */
1615 int
dmu_write_uio(objset_t * os,uint64_t object,zfs_uio_t * uio,uint64_t size,dmu_tx_t * tx)1616 dmu_write_uio(objset_t *os, uint64_t object, zfs_uio_t *uio, uint64_t size,
1617 dmu_tx_t *tx)
1618 {
1619 dnode_t *dn;
1620 int err;
1621
1622 if (size == 0)
1623 return (0);
1624
1625 err = dnode_hold(os, object, FTAG, &dn);
1626 if (err)
1627 return (err);
1628
1629 err = dmu_write_uio_dnode(dn, uio, size, tx);
1630
1631 dnode_rele(dn, FTAG);
1632
1633 return (err);
1634 }
1635 #endif /* _KERNEL */
1636
1637 static void
dmu_cached_bps(spa_t * spa,blkptr_t * bps,uint_t nbps,uint64_t * l1sz,uint64_t * l2sz)1638 dmu_cached_bps(spa_t *spa, blkptr_t *bps, uint_t nbps,
1639 uint64_t *l1sz, uint64_t *l2sz)
1640 {
1641 int cached_flags;
1642
1643 if (bps == NULL)
1644 return;
1645
1646 for (size_t blk_off = 0; blk_off < nbps; blk_off++) {
1647 blkptr_t *bp = &bps[blk_off];
1648
1649 if (BP_IS_HOLE(bp))
1650 continue;
1651
1652 cached_flags = arc_cached(spa, bp);
1653 if (cached_flags == 0)
1654 continue;
1655
1656 if ((cached_flags & (ARC_CACHED_IN_L1 | ARC_CACHED_IN_L2)) ==
1657 ARC_CACHED_IN_L2)
1658 *l2sz += BP_GET_LSIZE(bp);
1659 else
1660 *l1sz += BP_GET_LSIZE(bp);
1661 }
1662 }
1663
1664 /*
1665 * Estimate DMU object cached size.
1666 */
1667 int
dmu_object_cached_size(objset_t * os,uint64_t object,uint64_t * l1sz,uint64_t * l2sz)1668 dmu_object_cached_size(objset_t *os, uint64_t object,
1669 uint64_t *l1sz, uint64_t *l2sz)
1670 {
1671 dnode_t *dn;
1672 dmu_object_info_t doi;
1673 int err = 0;
1674
1675 *l1sz = *l2sz = 0;
1676
1677 if (dnode_hold(os, object, FTAG, &dn) != 0)
1678 return (0);
1679
1680 if (dn->dn_nlevels < 2) {
1681 dnode_rele(dn, FTAG);
1682 return (0);
1683 }
1684
1685 dmu_object_info_from_dnode(dn, &doi);
1686
1687 for (uint64_t off = 0; off < doi.doi_max_offset;
1688 off += dmu_prefetch_max) {
1689 /* dbuf_read doesn't prefetch L1 blocks. */
1690 dmu_prefetch_by_dnode(dn, 1, off,
1691 dmu_prefetch_max, ZIO_PRIORITY_SYNC_READ);
1692 }
1693
1694 /*
1695 * Hold all valid L1 blocks, asking ARC the status of each BP
1696 * contained in each such L1 block.
1697 */
1698 uint_t nbps = bp_span_in_blocks(dn->dn_indblkshift, 1);
1699 uint64_t l1blks = 1 + (dn->dn_maxblkid / nbps);
1700
1701 rw_enter(&dn->dn_struct_rwlock, RW_READER);
1702 for (uint64_t blk = 0; blk < l1blks; blk++) {
1703 dmu_buf_impl_t *db = NULL;
1704
1705 if (issig()) {
1706 /*
1707 * On interrupt, get out, and bubble up EINTR
1708 */
1709 err = EINTR;
1710 break;
1711 }
1712
1713 /*
1714 * If we get an i/o error here, the L1 can't be read,
1715 * and nothing under it could be cached, so we just
1716 * continue. Ignoring the error from dbuf_hold_impl
1717 * or from dbuf_read is then a reasonable choice.
1718 */
1719 err = dbuf_hold_impl(dn, 1, blk, B_TRUE, B_FALSE, FTAG, &db);
1720 if (err != 0) {
1721 /*
1722 * ignore error and continue
1723 */
1724 err = 0;
1725 continue;
1726 }
1727
1728 err = dbuf_read(db, NULL, DB_RF_CANFAIL);
1729 if (err == 0) {
1730 dmu_cached_bps(dmu_objset_spa(os), db->db.db_data,
1731 nbps, l1sz, l2sz);
1732 }
1733 /*
1734 * error may be ignored, and we continue
1735 */
1736 err = 0;
1737 dbuf_rele(db, FTAG);
1738 }
1739 rw_exit(&dn->dn_struct_rwlock);
1740
1741 dnode_rele(dn, FTAG);
1742 return (err);
1743 }
1744
1745 /*
1746 * Allocate a loaned anonymous arc buffer.
1747 */
1748 arc_buf_t *
dmu_request_arcbuf(dmu_buf_t * handle,int size)1749 dmu_request_arcbuf(dmu_buf_t *handle, int size)
1750 {
1751 dmu_buf_impl_t *db = (dmu_buf_impl_t *)handle;
1752
1753 return (arc_loan_buf(db->db_objset->os_spa, B_FALSE, size));
1754 }
1755
1756 /*
1757 * Free a loaned arc buffer.
1758 */
1759 void
dmu_return_arcbuf(arc_buf_t * buf)1760 dmu_return_arcbuf(arc_buf_t *buf)
1761 {
1762 arc_return_buf(buf, FTAG);
1763 arc_buf_destroy(buf, FTAG);
1764 }
1765
1766 /*
1767 * A "lightweight" write is faster than a regular write (e.g.
1768 * dmu_write_by_dnode() or dmu_assign_arcbuf_by_dnode()), because it avoids the
1769 * CPU cost of creating a dmu_buf_impl_t and arc_buf_[hdr_]_t. However, the
1770 * data can not be read or overwritten until the transaction's txg has been
1771 * synced. This makes it appropriate for workloads that are known to be
1772 * (temporarily) write-only, like "zfs receive".
1773 *
1774 * A single block is written, starting at the specified offset in bytes. If
1775 * the call is successful, it returns 0 and the provided abd has been
1776 * consumed (the caller should not free it).
1777 */
1778 int
dmu_lightweight_write_by_dnode(dnode_t * dn,uint64_t offset,abd_t * abd,const zio_prop_t * zp,zio_flag_t flags,dmu_tx_t * tx)1779 dmu_lightweight_write_by_dnode(dnode_t *dn, uint64_t offset, abd_t *abd,
1780 const zio_prop_t *zp, zio_flag_t flags, dmu_tx_t *tx)
1781 {
1782 dbuf_dirty_record_t *dr =
1783 dbuf_dirty_lightweight(dn, dbuf_whichblock(dn, 0, offset), tx);
1784 if (dr == NULL)
1785 return (SET_ERROR(EIO));
1786 dr->dt.dll.dr_abd = abd;
1787 dr->dt.dll.dr_props = *zp;
1788 dr->dt.dll.dr_flags = flags;
1789 return (0);
1790 }
1791
1792 /*
1793 * When possible directly assign passed loaned arc buffer to a dbuf.
1794 * If this is not possible copy the contents of passed arc buf via
1795 * dmu_write().
1796 */
1797 int
dmu_assign_arcbuf_by_dnode(dnode_t * dn,uint64_t offset,arc_buf_t * buf,dmu_tx_t * tx)1798 dmu_assign_arcbuf_by_dnode(dnode_t *dn, uint64_t offset, arc_buf_t *buf,
1799 dmu_tx_t *tx)
1800 {
1801 dmu_buf_impl_t *db;
1802 objset_t *os = dn->dn_objset;
1803 uint64_t object = dn->dn_object;
1804 uint32_t blksz = (uint32_t)arc_buf_lsize(buf);
1805 uint64_t blkid;
1806
1807 rw_enter(&dn->dn_struct_rwlock, RW_READER);
1808 blkid = dbuf_whichblock(dn, 0, offset);
1809 db = dbuf_hold(dn, blkid, FTAG);
1810 rw_exit(&dn->dn_struct_rwlock);
1811 if (db == NULL)
1812 return (SET_ERROR(EIO));
1813
1814 /*
1815 * We can only assign if the offset is aligned and the arc buf is the
1816 * same size as the dbuf.
1817 */
1818 if (offset == db->db.db_offset && blksz == db->db.db_size) {
1819 zfs_racct_write(os->os_spa, blksz, 1, 0);
1820 dbuf_assign_arcbuf(db, buf, tx);
1821 dbuf_rele(db, FTAG);
1822 } else {
1823 /* compressed bufs must always be assignable to their dbuf */
1824 ASSERT3U(arc_get_compression(buf), ==, ZIO_COMPRESS_OFF);
1825 ASSERT(!(buf->b_flags & ARC_BUF_FLAG_COMPRESSED));
1826
1827 dbuf_rele(db, FTAG);
1828 dmu_write(os, object, offset, blksz, buf->b_data, tx);
1829 dmu_return_arcbuf(buf);
1830 }
1831
1832 return (0);
1833 }
1834
1835 int
dmu_assign_arcbuf_by_dbuf(dmu_buf_t * handle,uint64_t offset,arc_buf_t * buf,dmu_tx_t * tx)1836 dmu_assign_arcbuf_by_dbuf(dmu_buf_t *handle, uint64_t offset, arc_buf_t *buf,
1837 dmu_tx_t *tx)
1838 {
1839 int err;
1840 dmu_buf_impl_t *db = (dmu_buf_impl_t *)handle;
1841
1842 DB_DNODE_ENTER(db);
1843 err = dmu_assign_arcbuf_by_dnode(DB_DNODE(db), offset, buf, tx);
1844 DB_DNODE_EXIT(db);
1845
1846 return (err);
1847 }
1848
1849 void
dmu_sync_ready(zio_t * zio,arc_buf_t * buf,void * varg)1850 dmu_sync_ready(zio_t *zio, arc_buf_t *buf, void *varg)
1851 {
1852 (void) buf;
1853 dmu_sync_arg_t *dsa = varg;
1854
1855 if (zio->io_error == 0) {
1856 dbuf_dirty_record_t *dr = dsa->dsa_dr;
1857 blkptr_t *bp = zio->io_bp;
1858
1859 if (BP_IS_HOLE(bp)) {
1860 dmu_buf_t *db = NULL;
1861 if (dr)
1862 db = &(dr->dr_dbuf->db);
1863 else
1864 db = dsa->dsa_zgd->zgd_db;
1865 /*
1866 * A block of zeros may compress to a hole, but the
1867 * block size still needs to be known for replay.
1868 */
1869 BP_SET_LSIZE(bp, db->db_size);
1870 } else if (!BP_IS_EMBEDDED(bp)) {
1871 ASSERT(BP_GET_LEVEL(bp) == 0);
1872 BP_SET_FILL(bp, 1);
1873 }
1874 }
1875 }
1876
1877 static void
dmu_sync_late_arrival_ready(zio_t * zio)1878 dmu_sync_late_arrival_ready(zio_t *zio)
1879 {
1880 dmu_sync_ready(zio, NULL, zio->io_private);
1881 }
1882
1883 void
dmu_sync_done(zio_t * zio,arc_buf_t * buf,void * varg)1884 dmu_sync_done(zio_t *zio, arc_buf_t *buf, void *varg)
1885 {
1886 (void) buf;
1887 dmu_sync_arg_t *dsa = varg;
1888 dbuf_dirty_record_t *dr = dsa->dsa_dr;
1889 dmu_buf_impl_t *db = dr->dr_dbuf;
1890 zgd_t *zgd = dsa->dsa_zgd;
1891
1892 /*
1893 * Record the vdev(s) backing this blkptr so they can be flushed after
1894 * the writes for the lwb have completed.
1895 */
1896 if (zgd && zio->io_error == 0) {
1897 zil_lwb_add_block(zgd->zgd_lwb, zgd->zgd_bp);
1898 }
1899
1900 mutex_enter(&db->db_mtx);
1901 ASSERT(dr->dt.dl.dr_override_state == DR_IN_DMU_SYNC);
1902 if (zio->io_error == 0) {
1903 ASSERT0(dr->dt.dl.dr_has_raw_params);
1904 dr->dt.dl.dr_nopwrite = !!(zio->io_flags & ZIO_FLAG_NOPWRITE);
1905 if (dr->dt.dl.dr_nopwrite) {
1906 blkptr_t *bp = zio->io_bp;
1907 blkptr_t *bp_orig = &zio->io_bp_orig;
1908 uint8_t chksum = BP_GET_CHECKSUM(bp_orig);
1909
1910 ASSERT(BP_EQUAL(bp, bp_orig));
1911 VERIFY(BP_EQUAL(bp, db->db_blkptr));
1912 ASSERT(zio->io_prop.zp_compress != ZIO_COMPRESS_OFF);
1913 VERIFY(zio_checksum_table[chksum].ci_flags &
1914 ZCHECKSUM_FLAG_NOPWRITE);
1915 }
1916 dr->dt.dl.dr_overridden_by = *zio->io_bp;
1917 dr->dt.dl.dr_override_state = DR_OVERRIDDEN;
1918 dr->dt.dl.dr_copies = zio->io_prop.zp_copies;
1919 dr->dt.dl.dr_gang_copies = zio->io_prop.zp_gang_copies;
1920
1921 /*
1922 * Old style holes are filled with all zeros, whereas
1923 * new-style holes maintain their lsize, type, level,
1924 * and birth time (see zio_write_compress). While we
1925 * need to reset the BP_SET_LSIZE() call that happened
1926 * in dmu_sync_ready for old style holes, we do *not*
1927 * want to wipe out the information contained in new
1928 * style holes. Thus, only zero out the block pointer if
1929 * it's an old style hole.
1930 */
1931 if (BP_IS_HOLE(&dr->dt.dl.dr_overridden_by) &&
1932 BP_GET_LOGICAL_BIRTH(&dr->dt.dl.dr_overridden_by) == 0)
1933 BP_ZERO(&dr->dt.dl.dr_overridden_by);
1934 } else {
1935 dr->dt.dl.dr_override_state = DR_NOT_OVERRIDDEN;
1936 }
1937
1938 cv_broadcast(&db->db_changed);
1939 mutex_exit(&db->db_mtx);
1940
1941 if (dsa->dsa_done)
1942 dsa->dsa_done(dsa->dsa_zgd, zio->io_error);
1943
1944 kmem_free(dsa, sizeof (*dsa));
1945 }
1946
1947 static void
dmu_sync_late_arrival_done(zio_t * zio)1948 dmu_sync_late_arrival_done(zio_t *zio)
1949 {
1950 blkptr_t *bp = zio->io_bp;
1951 dmu_sync_arg_t *dsa = zio->io_private;
1952 zgd_t *zgd = dsa->dsa_zgd;
1953
1954 if (zio->io_error == 0) {
1955 /*
1956 * Record the vdev(s) backing this blkptr so they can be
1957 * flushed after the writes for the lwb have completed.
1958 */
1959 zil_lwb_add_block(zgd->zgd_lwb, zgd->zgd_bp);
1960
1961 if (!BP_IS_HOLE(bp)) {
1962 blkptr_t *bp_orig __maybe_unused = &zio->io_bp_orig;
1963 ASSERT(!(zio->io_flags & ZIO_FLAG_NOPWRITE));
1964 ASSERT(BP_IS_HOLE(bp_orig) || !BP_EQUAL(bp, bp_orig));
1965 ASSERT(BP_GET_LOGICAL_BIRTH(zio->io_bp) == zio->io_txg);
1966 ASSERT(zio->io_txg > spa_syncing_txg(zio->io_spa));
1967 zio_free(zio->io_spa, zio->io_txg, zio->io_bp);
1968 }
1969 }
1970
1971 dmu_tx_commit(dsa->dsa_tx);
1972
1973 dsa->dsa_done(dsa->dsa_zgd, zio->io_error);
1974
1975 abd_free(zio->io_abd);
1976 kmem_free(dsa, sizeof (*dsa));
1977 }
1978
1979 static int
dmu_sync_late_arrival(zio_t * pio,objset_t * os,dmu_sync_cb_t * done,zgd_t * zgd,zio_prop_t * zp,zbookmark_phys_t * zb)1980 dmu_sync_late_arrival(zio_t *pio, objset_t *os, dmu_sync_cb_t *done, zgd_t *zgd,
1981 zio_prop_t *zp, zbookmark_phys_t *zb)
1982 {
1983 dmu_sync_arg_t *dsa;
1984 dmu_tx_t *tx;
1985 int error;
1986
1987 error = dbuf_read((dmu_buf_impl_t *)zgd->zgd_db, NULL,
1988 DB_RF_CANFAIL | DB_RF_NOPREFETCH);
1989 if (error != 0)
1990 return (error);
1991
1992 tx = dmu_tx_create(os);
1993 dmu_tx_hold_space(tx, zgd->zgd_db->db_size);
1994 /*
1995 * This transaction does not produce any dirty data or log blocks, so
1996 * it should not be throttled. All other cases wait for TXG sync, by
1997 * which time the log block we are writing will be obsolete, so we can
1998 * skip waiting and just return error here instead.
1999 */
2000 if (dmu_tx_assign(tx, DMU_TX_NOWAIT | DMU_TX_NOTHROTTLE) != 0) {
2001 dmu_tx_abort(tx);
2002 /* Make zl_get_data do txg_waited_synced() */
2003 return (SET_ERROR(EIO));
2004 }
2005
2006 /*
2007 * In order to prevent the zgd's lwb from being free'd prior to
2008 * dmu_sync_late_arrival_done() being called, we have to ensure
2009 * the lwb's "max txg" takes this tx's txg into account.
2010 */
2011 zil_lwb_add_txg(zgd->zgd_lwb, dmu_tx_get_txg(tx));
2012
2013 dsa = kmem_alloc(sizeof (dmu_sync_arg_t), KM_SLEEP);
2014 dsa->dsa_dr = NULL;
2015 dsa->dsa_done = done;
2016 dsa->dsa_zgd = zgd;
2017 dsa->dsa_tx = tx;
2018
2019 /*
2020 * Since we are currently syncing this txg, it's nontrivial to
2021 * determine what BP to nopwrite against, so we disable nopwrite.
2022 *
2023 * When syncing, the db_blkptr is initially the BP of the previous
2024 * txg. We can not nopwrite against it because it will be changed
2025 * (this is similar to the non-late-arrival case where the dbuf is
2026 * dirty in a future txg).
2027 *
2028 * Then dbuf_write_ready() sets bp_blkptr to the location we will write.
2029 * We can not nopwrite against it because although the BP will not
2030 * (typically) be changed, the data has not yet been persisted to this
2031 * location.
2032 *
2033 * Finally, when dbuf_write_done() is called, it is theoretically
2034 * possible to always nopwrite, because the data that was written in
2035 * this txg is the same data that we are trying to write. However we
2036 * would need to check that this dbuf is not dirty in any future
2037 * txg's (as we do in the normal dmu_sync() path). For simplicity, we
2038 * don't nopwrite in this case.
2039 */
2040 zp->zp_nopwrite = B_FALSE;
2041
2042 zio_nowait(zio_write(pio, os->os_spa, dmu_tx_get_txg(tx), zgd->zgd_bp,
2043 abd_get_from_buf(zgd->zgd_db->db_data, zgd->zgd_db->db_size),
2044 zgd->zgd_db->db_size, zgd->zgd_db->db_size, zp,
2045 dmu_sync_late_arrival_ready, NULL, dmu_sync_late_arrival_done,
2046 dsa, ZIO_PRIORITY_SYNC_WRITE, ZIO_FLAG_CANFAIL, zb));
2047
2048 return (0);
2049 }
2050
2051 /*
2052 * Intent log support: sync the block associated with db to disk.
2053 * N.B. and XXX: the caller is responsible for making sure that the
2054 * data isn't changing while dmu_sync() is writing it.
2055 *
2056 * Return values:
2057 *
2058 * EEXIST: this txg has already been synced, so there's nothing to do.
2059 * The caller should not log the write.
2060 *
2061 * ENOENT: the block was dbuf_free_range()'d, so there's nothing to do.
2062 * The caller should not log the write.
2063 *
2064 * EALREADY: this block is already in the process of being synced.
2065 * The caller should track its progress (somehow).
2066 *
2067 * EIO: could not do the I/O.
2068 * The caller should do a txg_wait_synced().
2069 *
2070 * 0: the I/O has been initiated.
2071 * The caller should log this blkptr in the done callback.
2072 * It is possible that the I/O will fail, in which case
2073 * the error will be reported to the done callback and
2074 * propagated to pio from zio_done().
2075 */
2076 int
dmu_sync(zio_t * pio,uint64_t txg,dmu_sync_cb_t * done,zgd_t * zgd)2077 dmu_sync(zio_t *pio, uint64_t txg, dmu_sync_cb_t *done, zgd_t *zgd)
2078 {
2079 dmu_buf_impl_t *db = (dmu_buf_impl_t *)zgd->zgd_db;
2080 objset_t *os = db->db_objset;
2081 dsl_dataset_t *ds = os->os_dsl_dataset;
2082 dbuf_dirty_record_t *dr, *dr_next;
2083 dmu_sync_arg_t *dsa;
2084 zbookmark_phys_t zb;
2085 zio_prop_t zp;
2086
2087 ASSERT(pio != NULL);
2088 ASSERT(txg != 0);
2089
2090 SET_BOOKMARK(&zb, ds->ds_object,
2091 db->db.db_object, db->db_level, db->db_blkid);
2092
2093 DB_DNODE_ENTER(db);
2094 dmu_write_policy(os, DB_DNODE(db), db->db_level, WP_DMU_SYNC, &zp);
2095 DB_DNODE_EXIT(db);
2096
2097 /*
2098 * If we're frozen (running ziltest), we always need to generate a bp.
2099 */
2100 if (txg > spa_freeze_txg(os->os_spa))
2101 return (dmu_sync_late_arrival(pio, os, done, zgd, &zp, &zb));
2102
2103 /*
2104 * Grabbing db_mtx now provides a barrier between dbuf_sync_leaf()
2105 * and us. If we determine that this txg is not yet syncing,
2106 * but it begins to sync a moment later, that's OK because the
2107 * sync thread will block in dbuf_sync_leaf() until we drop db_mtx.
2108 */
2109 mutex_enter(&db->db_mtx);
2110
2111 if (txg <= spa_last_synced_txg(os->os_spa)) {
2112 /*
2113 * This txg has already synced. There's nothing to do.
2114 */
2115 mutex_exit(&db->db_mtx);
2116 return (SET_ERROR(EEXIST));
2117 }
2118
2119 if (txg <= spa_syncing_txg(os->os_spa)) {
2120 /*
2121 * This txg is currently syncing, so we can't mess with
2122 * the dirty record anymore; just write a new log block.
2123 */
2124 mutex_exit(&db->db_mtx);
2125 return (dmu_sync_late_arrival(pio, os, done, zgd, &zp, &zb));
2126 }
2127
2128 dr = dbuf_find_dirty_eq(db, txg);
2129
2130 if (dr == NULL) {
2131 /*
2132 * There's no dr for this dbuf, so it must have been freed.
2133 * There's no need to log writes to freed blocks, so we're done.
2134 */
2135 mutex_exit(&db->db_mtx);
2136 return (SET_ERROR(ENOENT));
2137 }
2138
2139 dr_next = list_next(&db->db_dirty_records, dr);
2140 ASSERT(dr_next == NULL || dr_next->dr_txg < txg);
2141
2142 if (db->db_blkptr != NULL) {
2143 /*
2144 * We need to fill in zgd_bp with the current blkptr so that
2145 * the nopwrite code can check if we're writing the same
2146 * data that's already on disk. We can only nopwrite if we
2147 * are sure that after making the copy, db_blkptr will not
2148 * change until our i/o completes. We ensure this by
2149 * holding the db_mtx, and only allowing nopwrite if the
2150 * block is not already dirty (see below). This is verified
2151 * by dmu_sync_done(), which VERIFYs that the db_blkptr has
2152 * not changed.
2153 */
2154 *zgd->zgd_bp = *db->db_blkptr;
2155 }
2156
2157 /*
2158 * Assume the on-disk data is X, the current syncing data (in
2159 * txg - 1) is Y, and the current in-memory data is Z (currently
2160 * in dmu_sync).
2161 *
2162 * We usually want to perform a nopwrite if X and Z are the
2163 * same. However, if Y is different (i.e. the BP is going to
2164 * change before this write takes effect), then a nopwrite will
2165 * be incorrect - we would override with X, which could have
2166 * been freed when Y was written.
2167 *
2168 * (Note that this is not a concern when we are nop-writing from
2169 * syncing context, because X and Y must be identical, because
2170 * all previous txgs have been synced.)
2171 *
2172 * Therefore, we disable nopwrite if the current BP could change
2173 * before this TXG. There are two ways it could change: by
2174 * being dirty (dr_next is non-NULL), or by being freed
2175 * (dnode_block_freed()). This behavior is verified by
2176 * zio_done(), which VERIFYs that the override BP is identical
2177 * to the on-disk BP.
2178 */
2179 if (dr_next != NULL) {
2180 zp.zp_nopwrite = B_FALSE;
2181 } else {
2182 DB_DNODE_ENTER(db);
2183 if (dnode_block_freed(DB_DNODE(db), db->db_blkid))
2184 zp.zp_nopwrite = B_FALSE;
2185 DB_DNODE_EXIT(db);
2186 }
2187
2188 ASSERT(dr->dr_txg == txg);
2189 if (dr->dt.dl.dr_override_state == DR_IN_DMU_SYNC ||
2190 dr->dt.dl.dr_override_state == DR_OVERRIDDEN) {
2191 /*
2192 * We have already issued a sync write for this buffer,
2193 * or this buffer has already been synced. It could not
2194 * have been dirtied since, or we would have cleared the state.
2195 */
2196 mutex_exit(&db->db_mtx);
2197 return (SET_ERROR(EALREADY));
2198 }
2199
2200 ASSERT0(dr->dt.dl.dr_has_raw_params);
2201 ASSERT(dr->dt.dl.dr_override_state == DR_NOT_OVERRIDDEN);
2202 dr->dt.dl.dr_override_state = DR_IN_DMU_SYNC;
2203 mutex_exit(&db->db_mtx);
2204
2205 dsa = kmem_alloc(sizeof (dmu_sync_arg_t), KM_SLEEP);
2206 dsa->dsa_dr = dr;
2207 dsa->dsa_done = done;
2208 dsa->dsa_zgd = zgd;
2209 dsa->dsa_tx = NULL;
2210
2211 zio_nowait(arc_write(pio, os->os_spa, txg, zgd->zgd_bp,
2212 dr->dt.dl.dr_data, !DBUF_IS_CACHEABLE(db),
2213 dbuf_is_l2cacheable(db, NULL), &zp, dmu_sync_ready, NULL,
2214 dmu_sync_done, dsa, ZIO_PRIORITY_SYNC_WRITE, ZIO_FLAG_CANFAIL,
2215 &zb));
2216
2217 return (0);
2218 }
2219
2220 int
dmu_object_set_nlevels(objset_t * os,uint64_t object,int nlevels,dmu_tx_t * tx)2221 dmu_object_set_nlevels(objset_t *os, uint64_t object, int nlevels, dmu_tx_t *tx)
2222 {
2223 dnode_t *dn;
2224 int err;
2225
2226 err = dnode_hold(os, object, FTAG, &dn);
2227 if (err)
2228 return (err);
2229 err = dnode_set_nlevels(dn, nlevels, tx);
2230 dnode_rele(dn, FTAG);
2231 return (err);
2232 }
2233
2234 int
dmu_object_set_blocksize(objset_t * os,uint64_t object,uint64_t size,int ibs,dmu_tx_t * tx)2235 dmu_object_set_blocksize(objset_t *os, uint64_t object, uint64_t size, int ibs,
2236 dmu_tx_t *tx)
2237 {
2238 dnode_t *dn;
2239 int err;
2240
2241 err = dnode_hold(os, object, FTAG, &dn);
2242 if (err)
2243 return (err);
2244 err = dnode_set_blksz(dn, size, ibs, tx);
2245 dnode_rele(dn, FTAG);
2246 return (err);
2247 }
2248
2249 int
dmu_object_set_maxblkid(objset_t * os,uint64_t object,uint64_t maxblkid,dmu_tx_t * tx)2250 dmu_object_set_maxblkid(objset_t *os, uint64_t object, uint64_t maxblkid,
2251 dmu_tx_t *tx)
2252 {
2253 dnode_t *dn;
2254 int err;
2255
2256 err = dnode_hold(os, object, FTAG, &dn);
2257 if (err)
2258 return (err);
2259 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
2260 dnode_new_blkid(dn, maxblkid, tx, B_FALSE, B_TRUE);
2261 rw_exit(&dn->dn_struct_rwlock);
2262 dnode_rele(dn, FTAG);
2263 return (0);
2264 }
2265
2266 void
dmu_object_set_checksum(objset_t * os,uint64_t object,uint8_t checksum,dmu_tx_t * tx)2267 dmu_object_set_checksum(objset_t *os, uint64_t object, uint8_t checksum,
2268 dmu_tx_t *tx)
2269 {
2270 dnode_t *dn;
2271
2272 /*
2273 * Send streams include each object's checksum function. This
2274 * check ensures that the receiving system can understand the
2275 * checksum function transmitted.
2276 */
2277 ASSERT3U(checksum, <, ZIO_CHECKSUM_LEGACY_FUNCTIONS);
2278
2279 VERIFY0(dnode_hold(os, object, FTAG, &dn));
2280 ASSERT3U(checksum, <, ZIO_CHECKSUM_FUNCTIONS);
2281 dn->dn_checksum = checksum;
2282 dnode_setdirty(dn, tx);
2283 dnode_rele(dn, FTAG);
2284 }
2285
2286 void
dmu_object_set_compress(objset_t * os,uint64_t object,uint8_t compress,dmu_tx_t * tx)2287 dmu_object_set_compress(objset_t *os, uint64_t object, uint8_t compress,
2288 dmu_tx_t *tx)
2289 {
2290 dnode_t *dn;
2291
2292 /*
2293 * Send streams include each object's compression function. This
2294 * check ensures that the receiving system can understand the
2295 * compression function transmitted.
2296 */
2297 ASSERT3U(compress, <, ZIO_COMPRESS_LEGACY_FUNCTIONS);
2298
2299 VERIFY0(dnode_hold(os, object, FTAG, &dn));
2300 dn->dn_compress = compress;
2301 dnode_setdirty(dn, tx);
2302 dnode_rele(dn, FTAG);
2303 }
2304
2305 /*
2306 * When the "redundant_metadata" property is set to "most", only indirect
2307 * blocks of this level and higher will have an additional ditto block.
2308 */
2309 static const int zfs_redundant_metadata_most_ditto_level = 2;
2310
2311 void
dmu_write_policy(objset_t * os,dnode_t * dn,int level,int wp,zio_prop_t * zp)2312 dmu_write_policy(objset_t *os, dnode_t *dn, int level, int wp, zio_prop_t *zp)
2313 {
2314 dmu_object_type_t type = dn ? dn->dn_type : DMU_OT_OBJSET;
2315 boolean_t ismd = (level > 0 || DMU_OT_IS_METADATA(type) ||
2316 (wp & WP_SPILL));
2317 enum zio_checksum checksum = os->os_checksum;
2318 enum zio_compress compress = os->os_compress;
2319 uint8_t complevel = os->os_complevel;
2320 enum zio_checksum dedup_checksum = os->os_dedup_checksum;
2321 boolean_t dedup = B_FALSE;
2322 boolean_t nopwrite = B_FALSE;
2323 boolean_t dedup_verify = os->os_dedup_verify;
2324 boolean_t encrypt = B_FALSE;
2325 int copies = os->os_copies;
2326 int gang_copies = os->os_copies;
2327
2328 /*
2329 * We maintain different write policies for each of the following
2330 * types of data:
2331 * 1. metadata
2332 * 2. preallocated blocks (i.e. level-0 blocks of a dump device)
2333 * 3. all other level 0 blocks
2334 */
2335 if (ismd) {
2336 /*
2337 * XXX -- we should design a compression algorithm
2338 * that specializes in arrays of bps.
2339 */
2340 compress = zio_compress_select(os->os_spa,
2341 ZIO_COMPRESS_ON, ZIO_COMPRESS_ON);
2342
2343 /*
2344 * Metadata always gets checksummed. If the data
2345 * checksum is multi-bit correctable, and it's not a
2346 * ZBT-style checksum, then it's suitable for metadata
2347 * as well. Otherwise, the metadata checksum defaults
2348 * to fletcher4.
2349 */
2350 if (!(zio_checksum_table[checksum].ci_flags &
2351 ZCHECKSUM_FLAG_METADATA) ||
2352 (zio_checksum_table[checksum].ci_flags &
2353 ZCHECKSUM_FLAG_EMBEDDED))
2354 checksum = ZIO_CHECKSUM_FLETCHER_4;
2355
2356 switch (os->os_redundant_metadata) {
2357 case ZFS_REDUNDANT_METADATA_ALL:
2358 copies++;
2359 gang_copies++;
2360 break;
2361 case ZFS_REDUNDANT_METADATA_MOST:
2362 if (level >= zfs_redundant_metadata_most_ditto_level ||
2363 DMU_OT_IS_METADATA(type) || (wp & WP_SPILL))
2364 copies++;
2365 if (level + 1 >=
2366 zfs_redundant_metadata_most_ditto_level ||
2367 DMU_OT_IS_METADATA(type) || (wp & WP_SPILL))
2368 gang_copies++;
2369 break;
2370 case ZFS_REDUNDANT_METADATA_SOME:
2371 if (DMU_OT_IS_CRITICAL(type)) {
2372 copies++;
2373 gang_copies++;
2374 } else if (DMU_OT_IS_METADATA(type)) {
2375 gang_copies++;
2376 }
2377 break;
2378 case ZFS_REDUNDANT_METADATA_NONE:
2379 break;
2380 }
2381
2382 if (dmu_ddt_copies > 0) {
2383 /*
2384 * If this tuneable is set, and this is a write for a
2385 * dedup entry store (zap or log), then we treat it
2386 * something like ZFS_REDUNDANT_METADATA_MOST on a
2387 * regular dataset: this many copies, and one more for
2388 * "higher" indirect blocks. This specific exception is
2389 * necessary because dedup objects are stored in the
2390 * MOS, which always has the highest possible copies.
2391 */
2392 dmu_object_type_t stype =
2393 dn ? dn->dn_storage_type : DMU_OT_NONE;
2394 if (stype == DMU_OT_NONE)
2395 stype = type;
2396 if (stype == DMU_OT_DDT_ZAP) {
2397 copies = dmu_ddt_copies;
2398 if (level >=
2399 zfs_redundant_metadata_most_ditto_level)
2400 copies++;
2401 }
2402 }
2403 } else if (wp & WP_NOFILL) {
2404 ASSERT(level == 0);
2405
2406 /*
2407 * If we're writing preallocated blocks, we aren't actually
2408 * writing them so don't set any policy properties. These
2409 * blocks are currently only used by an external subsystem
2410 * outside of zfs (i.e. dump) and not written by the zio
2411 * pipeline.
2412 */
2413 compress = ZIO_COMPRESS_OFF;
2414 checksum = ZIO_CHECKSUM_OFF;
2415 } else {
2416 compress = zio_compress_select(os->os_spa, dn->dn_compress,
2417 compress);
2418 complevel = zio_complevel_select(os->os_spa, compress,
2419 complevel, complevel);
2420
2421 checksum = (dedup_checksum == ZIO_CHECKSUM_OFF) ?
2422 zio_checksum_select(dn->dn_checksum, checksum) :
2423 dedup_checksum;
2424
2425 /*
2426 * Determine dedup setting. If we are in dmu_sync(),
2427 * we won't actually dedup now because that's all
2428 * done in syncing context; but we do want to use the
2429 * dedup checksum. If the checksum is not strong
2430 * enough to ensure unique signatures, force
2431 * dedup_verify.
2432 */
2433 if (dedup_checksum != ZIO_CHECKSUM_OFF) {
2434 dedup = (wp & WP_DMU_SYNC) ? B_FALSE : B_TRUE;
2435 if (!(zio_checksum_table[checksum].ci_flags &
2436 ZCHECKSUM_FLAG_DEDUP))
2437 dedup_verify = B_TRUE;
2438 }
2439
2440 /*
2441 * Enable nopwrite if we have secure enough checksum
2442 * algorithm (see comment in zio_nop_write) and
2443 * compression is enabled. We don't enable nopwrite if
2444 * dedup is enabled as the two features are mutually
2445 * exclusive.
2446 */
2447 nopwrite = (!dedup && (zio_checksum_table[checksum].ci_flags &
2448 ZCHECKSUM_FLAG_NOPWRITE) &&
2449 compress != ZIO_COMPRESS_OFF && zfs_nopwrite_enabled);
2450
2451 if (os->os_redundant_metadata == ZFS_REDUNDANT_METADATA_ALL ||
2452 (os->os_redundant_metadata ==
2453 ZFS_REDUNDANT_METADATA_MOST &&
2454 zfs_redundant_metadata_most_ditto_level <= 1))
2455 gang_copies++;
2456 }
2457
2458 /*
2459 * All objects in an encrypted objset are protected from modification
2460 * via a MAC. Encrypted objects store their IV and salt in the last DVA
2461 * in the bp, so we cannot use all copies. Encrypted objects are also
2462 * not subject to nopwrite since writing the same data will still
2463 * result in a new ciphertext. Only encrypted blocks can be dedup'd
2464 * to avoid ambiguity in the dedup code since the DDT does not store
2465 * object types.
2466 */
2467 if (os->os_encrypted && (wp & WP_NOFILL) == 0) {
2468 encrypt = B_TRUE;
2469
2470 if (DMU_OT_IS_ENCRYPTED(type)) {
2471 copies = MIN(copies, SPA_DVAS_PER_BP - 1);
2472 gang_copies = MIN(gang_copies, SPA_DVAS_PER_BP - 1);
2473 nopwrite = B_FALSE;
2474 } else {
2475 dedup = B_FALSE;
2476 }
2477
2478 if (level <= 0 &&
2479 (type == DMU_OT_DNODE || type == DMU_OT_OBJSET)) {
2480 compress = ZIO_COMPRESS_EMPTY;
2481 }
2482 }
2483
2484 zp->zp_compress = compress;
2485 zp->zp_complevel = complevel;
2486 zp->zp_checksum = checksum;
2487 zp->zp_type = (wp & WP_SPILL) ? dn->dn_bonustype : type;
2488 zp->zp_level = level;
2489 zp->zp_copies = MIN(copies, spa_max_replication(os->os_spa));
2490 zp->zp_gang_copies = MIN(gang_copies, spa_max_replication(os->os_spa));
2491 zp->zp_dedup = dedup;
2492 zp->zp_dedup_verify = dedup && dedup_verify;
2493 zp->zp_nopwrite = nopwrite;
2494 zp->zp_encrypt = encrypt;
2495 zp->zp_byteorder = ZFS_HOST_BYTEORDER;
2496 zp->zp_direct_write = (wp & WP_DIRECT_WR) ? B_TRUE : B_FALSE;
2497 memset(zp->zp_salt, 0, ZIO_DATA_SALT_LEN);
2498 memset(zp->zp_iv, 0, ZIO_DATA_IV_LEN);
2499 memset(zp->zp_mac, 0, ZIO_DATA_MAC_LEN);
2500 zp->zp_zpl_smallblk = DMU_OT_IS_FILE(zp->zp_type) ?
2501 os->os_zpl_special_smallblock : 0;
2502 zp->zp_storage_type = dn ? dn->dn_storage_type : DMU_OT_NONE;
2503
2504 ASSERT3U(zp->zp_compress, !=, ZIO_COMPRESS_INHERIT);
2505 }
2506
2507 /*
2508 * Reports the location of data and holes in an object. In order to
2509 * accurately report holes all dirty data must be synced to disk. This
2510 * causes extremely poor performance when seeking for holes in a dirty file.
2511 * As a compromise, only provide hole data when the dnode is clean. When
2512 * a dnode is dirty report the dnode as having no holes by returning EBUSY
2513 * which is always safe to do.
2514 */
2515 int
dmu_offset_next(objset_t * os,uint64_t object,boolean_t hole,uint64_t * off)2516 dmu_offset_next(objset_t *os, uint64_t object, boolean_t hole, uint64_t *off)
2517 {
2518 dnode_t *dn;
2519 int restarted = 0, err;
2520
2521 restart:
2522 err = dnode_hold(os, object, FTAG, &dn);
2523 if (err)
2524 return (err);
2525
2526 rw_enter(&dn->dn_struct_rwlock, RW_READER);
2527
2528 if (dnode_is_dirty(dn)) {
2529 /*
2530 * If the zfs_dmu_offset_next_sync module option is enabled
2531 * then hole reporting has been requested. Dirty dnodes
2532 * must be synced to disk to accurately report holes.
2533 *
2534 * Provided a RL_READER rangelock spanning 0-UINT64_MAX is
2535 * held by the caller only a single restart will be required.
2536 * We tolerate callers which do not hold the rangelock by
2537 * returning EBUSY and not reporting holes after one restart.
2538 */
2539 if (zfs_dmu_offset_next_sync) {
2540 rw_exit(&dn->dn_struct_rwlock);
2541 dnode_rele(dn, FTAG);
2542
2543 if (restarted)
2544 return (SET_ERROR(EBUSY));
2545
2546 txg_wait_synced(dmu_objset_pool(os), 0);
2547 restarted = 1;
2548 goto restart;
2549 }
2550
2551 err = SET_ERROR(EBUSY);
2552 } else {
2553 err = dnode_next_offset(dn, DNODE_FIND_HAVELOCK |
2554 (hole ? DNODE_FIND_HOLE : 0), off, 1, 1, 0);
2555 }
2556
2557 rw_exit(&dn->dn_struct_rwlock);
2558 dnode_rele(dn, FTAG);
2559
2560 return (err);
2561 }
2562
2563 int
dmu_read_l0_bps(objset_t * os,uint64_t object,uint64_t offset,uint64_t length,blkptr_t * bps,size_t * nbpsp)2564 dmu_read_l0_bps(objset_t *os, uint64_t object, uint64_t offset, uint64_t length,
2565 blkptr_t *bps, size_t *nbpsp)
2566 {
2567 dmu_buf_t **dbp, *dbuf;
2568 dmu_buf_impl_t *db;
2569 blkptr_t *bp;
2570 int error, numbufs;
2571
2572 error = dmu_buf_hold_array(os, object, offset, length, FALSE, FTAG,
2573 &numbufs, &dbp);
2574 if (error != 0) {
2575 if (error == ESRCH) {
2576 error = SET_ERROR(ENXIO);
2577 }
2578 return (error);
2579 }
2580
2581 ASSERT3U(numbufs, <=, *nbpsp);
2582
2583 for (int i = 0; i < numbufs; i++) {
2584 dbuf = dbp[i];
2585 db = (dmu_buf_impl_t *)dbuf;
2586
2587 mutex_enter(&db->db_mtx);
2588
2589 if (!list_is_empty(&db->db_dirty_records)) {
2590 dbuf_dirty_record_t *dr;
2591
2592 dr = list_head(&db->db_dirty_records);
2593 if (dr->dt.dl.dr_brtwrite) {
2594 /*
2595 * This is very special case where we clone a
2596 * block and in the same transaction group we
2597 * read its BP (most likely to clone the clone).
2598 */
2599 bp = &dr->dt.dl.dr_overridden_by;
2600 } else {
2601 /*
2602 * The block was modified in the same
2603 * transaction group.
2604 */
2605 mutex_exit(&db->db_mtx);
2606 error = SET_ERROR(EAGAIN);
2607 goto out;
2608 }
2609 } else {
2610 bp = db->db_blkptr;
2611 }
2612
2613 mutex_exit(&db->db_mtx);
2614
2615 if (bp == NULL) {
2616 /*
2617 * The file size was increased, but the block was never
2618 * written, otherwise we would either have the block
2619 * pointer or the dirty record and would not get here.
2620 * It is effectively a hole, so report it as such.
2621 */
2622 BP_ZERO(&bps[i]);
2623 continue;
2624 }
2625 /*
2626 * Make sure we clone only data blocks.
2627 */
2628 if (BP_IS_METADATA(bp) && !BP_IS_HOLE(bp)) {
2629 error = SET_ERROR(EINVAL);
2630 goto out;
2631 }
2632
2633 /*
2634 * If the block was allocated in transaction group that is not
2635 * yet synced, we could clone it, but we couldn't write this
2636 * operation into ZIL, or it may be impossible to replay, since
2637 * the block may appear not yet allocated at that point.
2638 */
2639 if (BP_GET_BIRTH(bp) > spa_freeze_txg(os->os_spa)) {
2640 error = SET_ERROR(EINVAL);
2641 goto out;
2642 }
2643 if (BP_GET_BIRTH(bp) > spa_last_synced_txg(os->os_spa)) {
2644 error = SET_ERROR(EAGAIN);
2645 goto out;
2646 }
2647
2648 bps[i] = *bp;
2649 }
2650
2651 *nbpsp = numbufs;
2652 out:
2653 dmu_buf_rele_array(dbp, numbufs, FTAG);
2654
2655 return (error);
2656 }
2657
2658 int
dmu_brt_clone(objset_t * os,uint64_t object,uint64_t offset,uint64_t length,dmu_tx_t * tx,const blkptr_t * bps,size_t nbps)2659 dmu_brt_clone(objset_t *os, uint64_t object, uint64_t offset, uint64_t length,
2660 dmu_tx_t *tx, const blkptr_t *bps, size_t nbps)
2661 {
2662 spa_t *spa;
2663 dmu_buf_t **dbp, *dbuf;
2664 dmu_buf_impl_t *db;
2665 struct dirty_leaf *dl;
2666 dbuf_dirty_record_t *dr;
2667 const blkptr_t *bp;
2668 int error = 0, i, numbufs;
2669
2670 spa = os->os_spa;
2671
2672 VERIFY0(dmu_buf_hold_array(os, object, offset, length, FALSE, FTAG,
2673 &numbufs, &dbp));
2674 ASSERT3U(nbps, ==, numbufs);
2675
2676 /*
2677 * Before we start cloning make sure that the dbufs sizes match new BPs
2678 * sizes. If they don't, that's a no-go, as we are not able to shrink
2679 * dbufs.
2680 */
2681 for (i = 0; i < numbufs; i++) {
2682 dbuf = dbp[i];
2683 db = (dmu_buf_impl_t *)dbuf;
2684 bp = &bps[i];
2685
2686 ASSERT3U(db->db.db_object, !=, DMU_META_DNODE_OBJECT);
2687 ASSERT0(db->db_level);
2688 ASSERT(db->db_blkid != DMU_BONUS_BLKID);
2689 ASSERT(db->db_blkid != DMU_SPILL_BLKID);
2690
2691 if (!BP_IS_HOLE(bp) && BP_GET_LSIZE(bp) != dbuf->db_size) {
2692 error = SET_ERROR(EXDEV);
2693 goto out;
2694 }
2695 }
2696
2697 for (i = 0; i < numbufs; i++) {
2698 dbuf = dbp[i];
2699 db = (dmu_buf_impl_t *)dbuf;
2700 bp = &bps[i];
2701
2702 dmu_buf_will_clone_or_dio(dbuf, tx);
2703
2704 mutex_enter(&db->db_mtx);
2705
2706 dr = list_head(&db->db_dirty_records);
2707 VERIFY(dr != NULL);
2708 ASSERT3U(dr->dr_txg, ==, tx->tx_txg);
2709 dl = &dr->dt.dl;
2710 ASSERT0(dl->dr_has_raw_params);
2711 dl->dr_overridden_by = *bp;
2712 if (!BP_IS_HOLE(bp) || BP_GET_LOGICAL_BIRTH(bp) != 0) {
2713 if (!BP_IS_EMBEDDED(bp)) {
2714 BP_SET_BIRTH(&dl->dr_overridden_by, dr->dr_txg,
2715 BP_GET_BIRTH(bp));
2716 } else {
2717 BP_SET_LOGICAL_BIRTH(&dl->dr_overridden_by,
2718 dr->dr_txg);
2719 }
2720 }
2721 dl->dr_brtwrite = B_TRUE;
2722 dl->dr_override_state = DR_OVERRIDDEN;
2723
2724 mutex_exit(&db->db_mtx);
2725
2726 /*
2727 * When data in embedded into BP there is no need to create
2728 * BRT entry as there is no data block. Just copy the BP as
2729 * it contains the data.
2730 */
2731 if (!BP_IS_HOLE(bp) && !BP_IS_EMBEDDED(bp)) {
2732 brt_pending_add(spa, bp, tx);
2733 }
2734 }
2735 out:
2736 dmu_buf_rele_array(dbp, numbufs, FTAG);
2737
2738 return (error);
2739 }
2740
2741 void
__dmu_object_info_from_dnode(dnode_t * dn,dmu_object_info_t * doi)2742 __dmu_object_info_from_dnode(dnode_t *dn, dmu_object_info_t *doi)
2743 {
2744 dnode_phys_t *dnp = dn->dn_phys;
2745
2746 doi->doi_data_block_size = dn->dn_datablksz;
2747 doi->doi_metadata_block_size = dn->dn_indblkshift ?
2748 1ULL << dn->dn_indblkshift : 0;
2749 doi->doi_type = dn->dn_type;
2750 doi->doi_bonus_type = dn->dn_bonustype;
2751 doi->doi_bonus_size = dn->dn_bonuslen;
2752 doi->doi_dnodesize = dn->dn_num_slots << DNODE_SHIFT;
2753 doi->doi_indirection = dn->dn_nlevels;
2754 doi->doi_checksum = dn->dn_checksum;
2755 doi->doi_compress = dn->dn_compress;
2756 doi->doi_nblkptr = dn->dn_nblkptr;
2757 doi->doi_physical_blocks_512 = (DN_USED_BYTES(dnp) + 256) >> 9;
2758 doi->doi_max_offset = (dn->dn_maxblkid + 1) * dn->dn_datablksz;
2759 doi->doi_fill_count = 0;
2760 for (int i = 0; i < dnp->dn_nblkptr; i++)
2761 doi->doi_fill_count += BP_GET_FILL(&dnp->dn_blkptr[i]);
2762 }
2763
2764 void
dmu_object_info_from_dnode(dnode_t * dn,dmu_object_info_t * doi)2765 dmu_object_info_from_dnode(dnode_t *dn, dmu_object_info_t *doi)
2766 {
2767 rw_enter(&dn->dn_struct_rwlock, RW_READER);
2768 mutex_enter(&dn->dn_mtx);
2769
2770 __dmu_object_info_from_dnode(dn, doi);
2771
2772 mutex_exit(&dn->dn_mtx);
2773 rw_exit(&dn->dn_struct_rwlock);
2774 }
2775
2776 /*
2777 * Get information on a DMU object.
2778 * If doi is NULL, just indicates whether the object exists.
2779 */
2780 int
dmu_object_info(objset_t * os,uint64_t object,dmu_object_info_t * doi)2781 dmu_object_info(objset_t *os, uint64_t object, dmu_object_info_t *doi)
2782 {
2783 dnode_t *dn;
2784 int err = dnode_hold(os, object, FTAG, &dn);
2785
2786 if (err)
2787 return (err);
2788
2789 if (doi != NULL)
2790 dmu_object_info_from_dnode(dn, doi);
2791
2792 dnode_rele(dn, FTAG);
2793 return (0);
2794 }
2795
2796 /*
2797 * As above, but faster; can be used when you have a held dbuf in hand.
2798 */
2799 void
dmu_object_info_from_db(dmu_buf_t * db_fake,dmu_object_info_t * doi)2800 dmu_object_info_from_db(dmu_buf_t *db_fake, dmu_object_info_t *doi)
2801 {
2802 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
2803
2804 DB_DNODE_ENTER(db);
2805 dmu_object_info_from_dnode(DB_DNODE(db), doi);
2806 DB_DNODE_EXIT(db);
2807 }
2808
2809 /*
2810 * Faster still when you only care about the size.
2811 */
2812 void
dmu_object_size_from_db(dmu_buf_t * db_fake,uint32_t * blksize,u_longlong_t * nblk512)2813 dmu_object_size_from_db(dmu_buf_t *db_fake, uint32_t *blksize,
2814 u_longlong_t *nblk512)
2815 {
2816 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
2817 dnode_t *dn;
2818
2819 DB_DNODE_ENTER(db);
2820 dn = DB_DNODE(db);
2821
2822 *blksize = dn->dn_datablksz;
2823 /* add in number of slots used for the dnode itself */
2824 *nblk512 = ((DN_USED_BYTES(dn->dn_phys) + SPA_MINBLOCKSIZE/2) >>
2825 SPA_MINBLOCKSHIFT) + dn->dn_num_slots;
2826 DB_DNODE_EXIT(db);
2827 }
2828
2829 void
dmu_object_dnsize_from_db(dmu_buf_t * db_fake,int * dnsize)2830 dmu_object_dnsize_from_db(dmu_buf_t *db_fake, int *dnsize)
2831 {
2832 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
2833
2834 DB_DNODE_ENTER(db);
2835 *dnsize = DB_DNODE(db)->dn_num_slots << DNODE_SHIFT;
2836 DB_DNODE_EXIT(db);
2837 }
2838
2839 void
byteswap_uint64_array(void * vbuf,size_t size)2840 byteswap_uint64_array(void *vbuf, size_t size)
2841 {
2842 uint64_t *buf = vbuf;
2843 size_t count = size >> 3;
2844 int i;
2845
2846 ASSERT((size & 7) == 0);
2847
2848 for (i = 0; i < count; i++)
2849 buf[i] = BSWAP_64(buf[i]);
2850 }
2851
2852 void
byteswap_uint32_array(void * vbuf,size_t size)2853 byteswap_uint32_array(void *vbuf, size_t size)
2854 {
2855 uint32_t *buf = vbuf;
2856 size_t count = size >> 2;
2857 int i;
2858
2859 ASSERT((size & 3) == 0);
2860
2861 for (i = 0; i < count; i++)
2862 buf[i] = BSWAP_32(buf[i]);
2863 }
2864
2865 void
byteswap_uint16_array(void * vbuf,size_t size)2866 byteswap_uint16_array(void *vbuf, size_t size)
2867 {
2868 uint16_t *buf = vbuf;
2869 size_t count = size >> 1;
2870 int i;
2871
2872 ASSERT((size & 1) == 0);
2873
2874 for (i = 0; i < count; i++)
2875 buf[i] = BSWAP_16(buf[i]);
2876 }
2877
2878 void
byteswap_uint8_array(void * vbuf,size_t size)2879 byteswap_uint8_array(void *vbuf, size_t size)
2880 {
2881 (void) vbuf, (void) size;
2882 }
2883
2884 void
dmu_init(void)2885 dmu_init(void)
2886 {
2887 abd_init();
2888 zfs_dbgmsg_init();
2889 sa_cache_init();
2890 dmu_objset_init();
2891 dnode_init();
2892 zfetch_init();
2893 dmu_tx_init();
2894 l2arc_init();
2895 arc_init();
2896 dbuf_init();
2897 }
2898
2899 void
dmu_fini(void)2900 dmu_fini(void)
2901 {
2902 arc_fini(); /* arc depends on l2arc, so arc must go first */
2903 l2arc_fini();
2904 dmu_tx_fini();
2905 zfetch_fini();
2906 dbuf_fini();
2907 dnode_fini();
2908 dmu_objset_fini();
2909 sa_cache_fini();
2910 zfs_dbgmsg_fini();
2911 abd_fini();
2912 }
2913
2914 EXPORT_SYMBOL(dmu_bonus_hold);
2915 EXPORT_SYMBOL(dmu_bonus_hold_by_dnode);
2916 EXPORT_SYMBOL(dmu_buf_hold_array_by_bonus);
2917 EXPORT_SYMBOL(dmu_buf_rele_array);
2918 EXPORT_SYMBOL(dmu_prefetch);
2919 EXPORT_SYMBOL(dmu_prefetch_by_dnode);
2920 EXPORT_SYMBOL(dmu_prefetch_dnode);
2921 EXPORT_SYMBOL(dmu_free_range);
2922 EXPORT_SYMBOL(dmu_free_long_range);
2923 EXPORT_SYMBOL(dmu_free_long_object);
2924 EXPORT_SYMBOL(dmu_read);
2925 EXPORT_SYMBOL(dmu_read_by_dnode);
2926 EXPORT_SYMBOL(dmu_read_uio);
2927 EXPORT_SYMBOL(dmu_read_uio_dbuf);
2928 EXPORT_SYMBOL(dmu_read_uio_dnode);
2929 EXPORT_SYMBOL(dmu_write);
2930 EXPORT_SYMBOL(dmu_write_by_dnode);
2931 EXPORT_SYMBOL(dmu_write_by_dnode_flags);
2932 EXPORT_SYMBOL(dmu_write_uio);
2933 EXPORT_SYMBOL(dmu_write_uio_dbuf);
2934 EXPORT_SYMBOL(dmu_write_uio_dnode);
2935 EXPORT_SYMBOL(dmu_prealloc);
2936 EXPORT_SYMBOL(dmu_object_info);
2937 EXPORT_SYMBOL(dmu_object_info_from_dnode);
2938 EXPORT_SYMBOL(dmu_object_info_from_db);
2939 EXPORT_SYMBOL(dmu_object_size_from_db);
2940 EXPORT_SYMBOL(dmu_object_dnsize_from_db);
2941 EXPORT_SYMBOL(dmu_object_set_nlevels);
2942 EXPORT_SYMBOL(dmu_object_set_blocksize);
2943 EXPORT_SYMBOL(dmu_object_set_maxblkid);
2944 EXPORT_SYMBOL(dmu_object_set_checksum);
2945 EXPORT_SYMBOL(dmu_object_set_compress);
2946 EXPORT_SYMBOL(dmu_offset_next);
2947 EXPORT_SYMBOL(dmu_write_policy);
2948 EXPORT_SYMBOL(dmu_sync);
2949 EXPORT_SYMBOL(dmu_request_arcbuf);
2950 EXPORT_SYMBOL(dmu_return_arcbuf);
2951 EXPORT_SYMBOL(dmu_assign_arcbuf_by_dnode);
2952 EXPORT_SYMBOL(dmu_assign_arcbuf_by_dbuf);
2953 EXPORT_SYMBOL(dmu_buf_hold);
2954 EXPORT_SYMBOL(dmu_ot);
2955
2956 ZFS_MODULE_PARAM(zfs, zfs_, nopwrite_enabled, INT, ZMOD_RW,
2957 "Enable NOP writes");
2958
2959 ZFS_MODULE_PARAM(zfs, zfs_, per_txg_dirty_frees_percent, UINT, ZMOD_RW,
2960 "Percentage of dirtied blocks from frees in one TXG");
2961
2962 ZFS_MODULE_PARAM(zfs, zfs_, dmu_offset_next_sync, INT, ZMOD_RW,
2963 "Enable forcing txg sync to find holes");
2964
2965 ZFS_MODULE_PARAM(zfs, , dmu_prefetch_max, UINT, ZMOD_RW,
2966 "Limit one prefetch call to this size");
2967
2968 ZFS_MODULE_PARAM(zfs, , dmu_ddt_copies, UINT, ZMOD_RW,
2969 "Override copies= for dedup objects");
2970