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[mirror_zfs.git] / module / zfs / dmu.c
1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21 /*
22 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
23 * Copyright (c) 2011, 2020 by Delphix. All rights reserved.
24 * Copyright (c) 2013 by Saso Kiselkov. All rights reserved.
25 * Copyright (c) 2013, Joyent, Inc. All rights reserved.
26 * Copyright (c) 2016, Nexenta Systems, Inc. All rights reserved.
27 * Copyright (c) 2015 by Chunwei Chen. All rights reserved.
28 * Copyright (c) 2019 Datto Inc.
29 * Copyright (c) 2019, Klara Inc.
30 * Copyright (c) 2019, Allan Jude
31 */
32
33 #include <sys/dmu.h>
34 #include <sys/dmu_impl.h>
35 #include <sys/dmu_tx.h>
36 #include <sys/dbuf.h>
37 #include <sys/dnode.h>
38 #include <sys/zfs_context.h>
39 #include <sys/dmu_objset.h>
40 #include <sys/dmu_traverse.h>
41 #include <sys/dsl_dataset.h>
42 #include <sys/dsl_dir.h>
43 #include <sys/dsl_pool.h>
44 #include <sys/dsl_synctask.h>
45 #include <sys/dsl_prop.h>
46 #include <sys/dmu_zfetch.h>
47 #include <sys/zfs_ioctl.h>
48 #include <sys/zap.h>
49 #include <sys/zio_checksum.h>
50 #include <sys/zio_compress.h>
51 #include <sys/sa.h>
52 #include <sys/zfeature.h>
53 #include <sys/abd.h>
54 #include <sys/trace_zfs.h>
55 #include <sys/zfs_racct.h>
56 #include <sys/zfs_rlock.h>
57 #ifdef _KERNEL
58 #include <sys/vmsystm.h>
59 #include <sys/zfs_znode.h>
60 #endif
61
62 /*
63 * Enable/disable nopwrite feature.
64 */
65 static int zfs_nopwrite_enabled = 1;
66
67 /*
68 * Tunable to control percentage of dirtied L1 blocks from frees allowed into
69 * one TXG. After this threshold is crossed, additional dirty blocks from frees
70 * will wait until the next TXG.
71 * A value of zero will disable this throttle.
72 */
73 static unsigned long zfs_per_txg_dirty_frees_percent = 5;
74
75 /*
76 * Enable/disable forcing txg sync when dirty checking for holes with lseek().
77 * By default this is enabled to ensure accurate hole reporting, it can result
78 * in a significant performance penalty for lseek(SEEK_HOLE) heavy workloads.
79 * Disabling this option will result in holes never being reported in dirty
80 * files which is always safe.
81 */
82 static int zfs_dmu_offset_next_sync = 1;
83
84 /*
85 * Limit the amount we can prefetch with one call to this amount. This
86 * helps to limit the amount of memory that can be used by prefetching.
87 * Larger objects should be prefetched a bit at a time.
88 */
89 static int dmu_prefetch_max = 8 * SPA_MAXBLOCKSIZE;
90
91 const dmu_object_type_info_t dmu_ot[DMU_OT_NUMTYPES] = {
92 {DMU_BSWAP_UINT8, TRUE, FALSE, FALSE, "unallocated" },
93 {DMU_BSWAP_ZAP, TRUE, TRUE, FALSE, "object directory" },
94 {DMU_BSWAP_UINT64, TRUE, TRUE, FALSE, "object array" },
95 {DMU_BSWAP_UINT8, TRUE, FALSE, FALSE, "packed nvlist" },
96 {DMU_BSWAP_UINT64, TRUE, FALSE, FALSE, "packed nvlist size" },
97 {DMU_BSWAP_UINT64, TRUE, FALSE, FALSE, "bpobj" },
98 {DMU_BSWAP_UINT64, TRUE, FALSE, FALSE, "bpobj header" },
99 {DMU_BSWAP_UINT64, TRUE, FALSE, FALSE, "SPA space map header" },
100 {DMU_BSWAP_UINT64, TRUE, FALSE, FALSE, "SPA space map" },
101 {DMU_BSWAP_UINT64, TRUE, FALSE, TRUE, "ZIL intent log" },
102 {DMU_BSWAP_DNODE, TRUE, FALSE, TRUE, "DMU dnode" },
103 {DMU_BSWAP_OBJSET, TRUE, TRUE, FALSE, "DMU objset" },
104 {DMU_BSWAP_UINT64, TRUE, TRUE, FALSE, "DSL directory" },
105 {DMU_BSWAP_ZAP, TRUE, TRUE, FALSE, "DSL directory child map"},
106 {DMU_BSWAP_ZAP, TRUE, TRUE, FALSE, "DSL dataset snap map" },
107 {DMU_BSWAP_ZAP, TRUE, TRUE, FALSE, "DSL props" },
108 {DMU_BSWAP_UINT64, TRUE, TRUE, FALSE, "DSL dataset" },
109 {DMU_BSWAP_ZNODE, TRUE, FALSE, FALSE, "ZFS znode" },
110 {DMU_BSWAP_OLDACL, TRUE, FALSE, TRUE, "ZFS V0 ACL" },
111 {DMU_BSWAP_UINT8, FALSE, FALSE, TRUE, "ZFS plain file" },
112 {DMU_BSWAP_ZAP, TRUE, FALSE, TRUE, "ZFS directory" },
113 {DMU_BSWAP_ZAP, TRUE, FALSE, FALSE, "ZFS master node" },
114 {DMU_BSWAP_ZAP, TRUE, FALSE, TRUE, "ZFS delete queue" },
115 {DMU_BSWAP_UINT8, FALSE, FALSE, TRUE, "zvol object" },
116 {DMU_BSWAP_ZAP, TRUE, FALSE, FALSE, "zvol prop" },
117 {DMU_BSWAP_UINT8, FALSE, FALSE, TRUE, "other uint8[]" },
118 {DMU_BSWAP_UINT64, FALSE, FALSE, TRUE, "other uint64[]" },
119 {DMU_BSWAP_ZAP, TRUE, FALSE, FALSE, "other ZAP" },
120 {DMU_BSWAP_ZAP, TRUE, FALSE, FALSE, "persistent error log" },
121 {DMU_BSWAP_UINT8, TRUE, FALSE, FALSE, "SPA history" },
122 {DMU_BSWAP_UINT64, TRUE, FALSE, FALSE, "SPA history offsets" },
123 {DMU_BSWAP_ZAP, TRUE, TRUE, FALSE, "Pool properties" },
124 {DMU_BSWAP_ZAP, TRUE, TRUE, FALSE, "DSL permissions" },
125 {DMU_BSWAP_ACL, TRUE, FALSE, TRUE, "ZFS ACL" },
126 {DMU_BSWAP_UINT8, TRUE, FALSE, TRUE, "ZFS SYSACL" },
127 {DMU_BSWAP_UINT8, TRUE, FALSE, TRUE, "FUID table" },
128 {DMU_BSWAP_UINT64, TRUE, FALSE, FALSE, "FUID table size" },
129 {DMU_BSWAP_ZAP, TRUE, TRUE, FALSE, "DSL dataset next clones"},
130 {DMU_BSWAP_ZAP, TRUE, FALSE, FALSE, "scan work queue" },
131 {DMU_BSWAP_ZAP, TRUE, FALSE, TRUE, "ZFS user/group/project used" },
132 {DMU_BSWAP_ZAP, TRUE, FALSE, TRUE, "ZFS user/group/project quota"},
133 {DMU_BSWAP_ZAP, TRUE, TRUE, FALSE, "snapshot refcount tags"},
134 {DMU_BSWAP_ZAP, TRUE, FALSE, FALSE, "DDT ZAP algorithm" },
135 {DMU_BSWAP_ZAP, TRUE, FALSE, FALSE, "DDT statistics" },
136 {DMU_BSWAP_UINT8, TRUE, FALSE, TRUE, "System attributes" },
137 {DMU_BSWAP_ZAP, TRUE, FALSE, TRUE, "SA master node" },
138 {DMU_BSWAP_ZAP, TRUE, FALSE, TRUE, "SA attr registration" },
139 {DMU_BSWAP_ZAP, TRUE, FALSE, TRUE, "SA attr layouts" },
140 {DMU_BSWAP_ZAP, TRUE, FALSE, FALSE, "scan translations" },
141 {DMU_BSWAP_UINT8, FALSE, FALSE, TRUE, "deduplicated block" },
142 {DMU_BSWAP_ZAP, TRUE, TRUE, FALSE, "DSL deadlist map" },
143 {DMU_BSWAP_UINT64, TRUE, TRUE, FALSE, "DSL deadlist map hdr" },
144 {DMU_BSWAP_ZAP, TRUE, TRUE, FALSE, "DSL dir clones" },
145 {DMU_BSWAP_UINT64, TRUE, FALSE, FALSE, "bpobj subobj" }
146 };
147
148 const dmu_object_byteswap_info_t dmu_ot_byteswap[DMU_BSWAP_NUMFUNCS] = {
149 { byteswap_uint8_array, "uint8" },
150 { byteswap_uint16_array, "uint16" },
151 { byteswap_uint32_array, "uint32" },
152 { byteswap_uint64_array, "uint64" },
153 { zap_byteswap, "zap" },
154 { dnode_buf_byteswap, "dnode" },
155 { dmu_objset_byteswap, "objset" },
156 { zfs_znode_byteswap, "znode" },
157 { zfs_oldacl_byteswap, "oldacl" },
158 { zfs_acl_byteswap, "acl" }
159 };
160
161 static int
162 dmu_buf_hold_noread_by_dnode(dnode_t *dn, uint64_t offset,
163 void *tag, dmu_buf_t **dbp)
164 {
165 uint64_t blkid;
166 dmu_buf_impl_t *db;
167
168 rw_enter(&dn->dn_struct_rwlock, RW_READER);
169 blkid = dbuf_whichblock(dn, 0, offset);
170 db = dbuf_hold(dn, blkid, tag);
171 rw_exit(&dn->dn_struct_rwlock);
172
173 if (db == NULL) {
174 *dbp = NULL;
175 return (SET_ERROR(EIO));
176 }
177
178 *dbp = &db->db;
179 return (0);
180 }
181 int
182 dmu_buf_hold_noread(objset_t *os, uint64_t object, uint64_t offset,
183 void *tag, dmu_buf_t **dbp)
184 {
185 dnode_t *dn;
186 uint64_t blkid;
187 dmu_buf_impl_t *db;
188 int err;
189
190 err = dnode_hold(os, object, FTAG, &dn);
191 if (err)
192 return (err);
193 rw_enter(&dn->dn_struct_rwlock, RW_READER);
194 blkid = dbuf_whichblock(dn, 0, offset);
195 db = dbuf_hold(dn, blkid, tag);
196 rw_exit(&dn->dn_struct_rwlock);
197 dnode_rele(dn, FTAG);
198
199 if (db == NULL) {
200 *dbp = NULL;
201 return (SET_ERROR(EIO));
202 }
203
204 *dbp = &db->db;
205 return (err);
206 }
207
208 int
209 dmu_buf_hold_by_dnode(dnode_t *dn, uint64_t offset,
210 void *tag, dmu_buf_t **dbp, int flags)
211 {
212 int err;
213 int db_flags = DB_RF_CANFAIL;
214
215 if (flags & DMU_READ_NO_PREFETCH)
216 db_flags |= DB_RF_NOPREFETCH;
217 if (flags & DMU_READ_NO_DECRYPT)
218 db_flags |= DB_RF_NO_DECRYPT;
219
220 err = dmu_buf_hold_noread_by_dnode(dn, offset, tag, dbp);
221 if (err == 0) {
222 dmu_buf_impl_t *db = (dmu_buf_impl_t *)(*dbp);
223 err = dbuf_read(db, NULL, db_flags);
224 if (err != 0) {
225 dbuf_rele(db, tag);
226 *dbp = NULL;
227 }
228 }
229
230 return (err);
231 }
232
233 int
234 dmu_buf_hold(objset_t *os, uint64_t object, uint64_t offset,
235 void *tag, dmu_buf_t **dbp, int flags)
236 {
237 int err;
238 int db_flags = DB_RF_CANFAIL;
239
240 if (flags & DMU_READ_NO_PREFETCH)
241 db_flags |= DB_RF_NOPREFETCH;
242 if (flags & DMU_READ_NO_DECRYPT)
243 db_flags |= DB_RF_NO_DECRYPT;
244
245 err = dmu_buf_hold_noread(os, object, offset, tag, dbp);
246 if (err == 0) {
247 dmu_buf_impl_t *db = (dmu_buf_impl_t *)(*dbp);
248 err = dbuf_read(db, NULL, db_flags);
249 if (err != 0) {
250 dbuf_rele(db, tag);
251 *dbp = NULL;
252 }
253 }
254
255 return (err);
256 }
257
258 int
259 dmu_bonus_max(void)
260 {
261 return (DN_OLD_MAX_BONUSLEN);
262 }
263
264 int
265 dmu_set_bonus(dmu_buf_t *db_fake, int newsize, dmu_tx_t *tx)
266 {
267 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
268 dnode_t *dn;
269 int error;
270
271 DB_DNODE_ENTER(db);
272 dn = DB_DNODE(db);
273
274 if (dn->dn_bonus != db) {
275 error = SET_ERROR(EINVAL);
276 } else if (newsize < 0 || newsize > db_fake->db_size) {
277 error = SET_ERROR(EINVAL);
278 } else {
279 dnode_setbonuslen(dn, newsize, tx);
280 error = 0;
281 }
282
283 DB_DNODE_EXIT(db);
284 return (error);
285 }
286
287 int
288 dmu_set_bonustype(dmu_buf_t *db_fake, dmu_object_type_t type, dmu_tx_t *tx)
289 {
290 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
291 dnode_t *dn;
292 int error;
293
294 DB_DNODE_ENTER(db);
295 dn = DB_DNODE(db);
296
297 if (!DMU_OT_IS_VALID(type)) {
298 error = SET_ERROR(EINVAL);
299 } else if (dn->dn_bonus != db) {
300 error = SET_ERROR(EINVAL);
301 } else {
302 dnode_setbonus_type(dn, type, tx);
303 error = 0;
304 }
305
306 DB_DNODE_EXIT(db);
307 return (error);
308 }
309
310 dmu_object_type_t
311 dmu_get_bonustype(dmu_buf_t *db_fake)
312 {
313 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
314 dnode_t *dn;
315 dmu_object_type_t type;
316
317 DB_DNODE_ENTER(db);
318 dn = DB_DNODE(db);
319 type = dn->dn_bonustype;
320 DB_DNODE_EXIT(db);
321
322 return (type);
323 }
324
325 int
326 dmu_rm_spill(objset_t *os, uint64_t object, dmu_tx_t *tx)
327 {
328 dnode_t *dn;
329 int error;
330
331 error = dnode_hold(os, object, FTAG, &dn);
332 dbuf_rm_spill(dn, tx);
333 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
334 dnode_rm_spill(dn, tx);
335 rw_exit(&dn->dn_struct_rwlock);
336 dnode_rele(dn, FTAG);
337 return (error);
338 }
339
340 /*
341 * Lookup and hold the bonus buffer for the provided dnode. If the dnode
342 * has not yet been allocated a new bonus dbuf a will be allocated.
343 * Returns ENOENT, EIO, or 0.
344 */
345 int dmu_bonus_hold_by_dnode(dnode_t *dn, void *tag, dmu_buf_t **dbp,
346 uint32_t flags)
347 {
348 dmu_buf_impl_t *db;
349 int error;
350 uint32_t db_flags = DB_RF_MUST_SUCCEED;
351
352 if (flags & DMU_READ_NO_PREFETCH)
353 db_flags |= DB_RF_NOPREFETCH;
354 if (flags & DMU_READ_NO_DECRYPT)
355 db_flags |= DB_RF_NO_DECRYPT;
356
357 rw_enter(&dn->dn_struct_rwlock, RW_READER);
358 if (dn->dn_bonus == NULL) {
359 rw_exit(&dn->dn_struct_rwlock);
360 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
361 if (dn->dn_bonus == NULL)
362 dbuf_create_bonus(dn);
363 }
364 db = dn->dn_bonus;
365
366 /* as long as the bonus buf is held, the dnode will be held */
367 if (zfs_refcount_add(&db->db_holds, tag) == 1) {
368 VERIFY(dnode_add_ref(dn, db));
369 atomic_inc_32(&dn->dn_dbufs_count);
370 }
371
372 /*
373 * Wait to drop dn_struct_rwlock until after adding the bonus dbuf's
374 * hold and incrementing the dbuf count to ensure that dnode_move() sees
375 * a dnode hold for every dbuf.
376 */
377 rw_exit(&dn->dn_struct_rwlock);
378
379 error = dbuf_read(db, NULL, db_flags);
380 if (error) {
381 dnode_evict_bonus(dn);
382 dbuf_rele(db, tag);
383 *dbp = NULL;
384 return (error);
385 }
386
387 *dbp = &db->db;
388 return (0);
389 }
390
391 int
392 dmu_bonus_hold(objset_t *os, uint64_t object, void *tag, dmu_buf_t **dbp)
393 {
394 dnode_t *dn;
395 int error;
396
397 error = dnode_hold(os, object, FTAG, &dn);
398 if (error)
399 return (error);
400
401 error = dmu_bonus_hold_by_dnode(dn, tag, dbp, DMU_READ_NO_PREFETCH);
402 dnode_rele(dn, FTAG);
403
404 return (error);
405 }
406
407 /*
408 * returns ENOENT, EIO, or 0.
409 *
410 * This interface will allocate a blank spill dbuf when a spill blk
411 * doesn't already exist on the dnode.
412 *
413 * if you only want to find an already existing spill db, then
414 * dmu_spill_hold_existing() should be used.
415 */
416 int
417 dmu_spill_hold_by_dnode(dnode_t *dn, uint32_t flags, void *tag, dmu_buf_t **dbp)
418 {
419 dmu_buf_impl_t *db = NULL;
420 int err;
421
422 if ((flags & DB_RF_HAVESTRUCT) == 0)
423 rw_enter(&dn->dn_struct_rwlock, RW_READER);
424
425 db = dbuf_hold(dn, DMU_SPILL_BLKID, tag);
426
427 if ((flags & DB_RF_HAVESTRUCT) == 0)
428 rw_exit(&dn->dn_struct_rwlock);
429
430 if (db == NULL) {
431 *dbp = NULL;
432 return (SET_ERROR(EIO));
433 }
434 err = dbuf_read(db, NULL, flags);
435 if (err == 0)
436 *dbp = &db->db;
437 else {
438 dbuf_rele(db, tag);
439 *dbp = NULL;
440 }
441 return (err);
442 }
443
444 int
445 dmu_spill_hold_existing(dmu_buf_t *bonus, void *tag, dmu_buf_t **dbp)
446 {
447 dmu_buf_impl_t *db = (dmu_buf_impl_t *)bonus;
448 dnode_t *dn;
449 int err;
450
451 DB_DNODE_ENTER(db);
452 dn = DB_DNODE(db);
453
454 if (spa_version(dn->dn_objset->os_spa) < SPA_VERSION_SA) {
455 err = SET_ERROR(EINVAL);
456 } else {
457 rw_enter(&dn->dn_struct_rwlock, RW_READER);
458
459 if (!dn->dn_have_spill) {
460 err = SET_ERROR(ENOENT);
461 } else {
462 err = dmu_spill_hold_by_dnode(dn,
463 DB_RF_HAVESTRUCT | DB_RF_CANFAIL, tag, dbp);
464 }
465
466 rw_exit(&dn->dn_struct_rwlock);
467 }
468
469 DB_DNODE_EXIT(db);
470 return (err);
471 }
472
473 int
474 dmu_spill_hold_by_bonus(dmu_buf_t *bonus, uint32_t flags, void *tag,
475 dmu_buf_t **dbp)
476 {
477 dmu_buf_impl_t *db = (dmu_buf_impl_t *)bonus;
478 dnode_t *dn;
479 int err;
480 uint32_t db_flags = DB_RF_CANFAIL;
481
482 if (flags & DMU_READ_NO_DECRYPT)
483 db_flags |= DB_RF_NO_DECRYPT;
484
485 DB_DNODE_ENTER(db);
486 dn = DB_DNODE(db);
487 err = dmu_spill_hold_by_dnode(dn, db_flags, tag, dbp);
488 DB_DNODE_EXIT(db);
489
490 return (err);
491 }
492
493 /*
494 * Note: longer-term, we should modify all of the dmu_buf_*() interfaces
495 * to take a held dnode rather than <os, object> -- the lookup is wasteful,
496 * and can induce severe lock contention when writing to several files
497 * whose dnodes are in the same block.
498 */
499 int
500 dmu_buf_hold_array_by_dnode(dnode_t *dn, uint64_t offset, uint64_t length,
501 boolean_t read, void *tag, int *numbufsp, dmu_buf_t ***dbpp, uint32_t flags)
502 {
503 dmu_buf_t **dbp;
504 zstream_t *zs = NULL;
505 uint64_t blkid, nblks, i;
506 uint32_t dbuf_flags;
507 int err;
508 zio_t *zio = NULL;
509 boolean_t missed = B_FALSE;
510
511 ASSERT(length <= DMU_MAX_ACCESS);
512
513 /*
514 * Note: We directly notify the prefetch code of this read, so that
515 * we can tell it about the multi-block read. dbuf_read() only knows
516 * about the one block it is accessing.
517 */
518 dbuf_flags = DB_RF_CANFAIL | DB_RF_NEVERWAIT | DB_RF_HAVESTRUCT |
519 DB_RF_NOPREFETCH;
520
521 rw_enter(&dn->dn_struct_rwlock, RW_READER);
522 if (dn->dn_datablkshift) {
523 int blkshift = dn->dn_datablkshift;
524 nblks = (P2ROUNDUP(offset + length, 1ULL << blkshift) -
525 P2ALIGN(offset, 1ULL << blkshift)) >> blkshift;
526 } else {
527 if (offset + length > dn->dn_datablksz) {
528 zfs_panic_recover("zfs: accessing past end of object "
529 "%llx/%llx (size=%u access=%llu+%llu)",
530 (longlong_t)dn->dn_objset->
531 os_dsl_dataset->ds_object,
532 (longlong_t)dn->dn_object, dn->dn_datablksz,
533 (longlong_t)offset, (longlong_t)length);
534 rw_exit(&dn->dn_struct_rwlock);
535 return (SET_ERROR(EIO));
536 }
537 nblks = 1;
538 }
539 dbp = kmem_zalloc(sizeof (dmu_buf_t *) * nblks, KM_SLEEP);
540
541 if (read)
542 zio = zio_root(dn->dn_objset->os_spa, NULL, NULL,
543 ZIO_FLAG_CANFAIL);
544 blkid = dbuf_whichblock(dn, 0, offset);
545 if ((flags & DMU_READ_NO_PREFETCH) == 0 &&
546 DNODE_META_IS_CACHEABLE(dn) && length <= zfetch_array_rd_sz) {
547 /*
548 * Prepare the zfetch before initiating the demand reads, so
549 * that if multiple threads block on same indirect block, we
550 * base predictions on the original less racy request order.
551 */
552 zs = dmu_zfetch_prepare(&dn->dn_zfetch, blkid, nblks,
553 read && DNODE_IS_CACHEABLE(dn), B_TRUE);
554 }
555 for (i = 0; i < nblks; i++) {
556 dmu_buf_impl_t *db = dbuf_hold(dn, blkid + i, tag);
557 if (db == NULL) {
558 if (zs)
559 dmu_zfetch_run(zs, missed, B_TRUE);
560 rw_exit(&dn->dn_struct_rwlock);
561 dmu_buf_rele_array(dbp, nblks, tag);
562 if (read)
563 zio_nowait(zio);
564 return (SET_ERROR(EIO));
565 }
566
567 /*
568 * Initiate async demand data read.
569 * We check the db_state after calling dbuf_read() because
570 * (1) dbuf_read() may change the state to CACHED due to a
571 * hit in the ARC, and (2) on a cache miss, a child will
572 * have been added to "zio" but not yet completed, so the
573 * state will not yet be CACHED.
574 */
575 if (read) {
576 (void) dbuf_read(db, zio, dbuf_flags);
577 if (db->db_state != DB_CACHED)
578 missed = B_TRUE;
579 }
580 dbp[i] = &db->db;
581 }
582
583 if (!read)
584 zfs_racct_write(length, nblks);
585
586 if (zs)
587 dmu_zfetch_run(zs, missed, B_TRUE);
588 rw_exit(&dn->dn_struct_rwlock);
589
590 if (read) {
591 /* wait for async read i/o */
592 err = zio_wait(zio);
593 if (err) {
594 dmu_buf_rele_array(dbp, nblks, tag);
595 return (err);
596 }
597
598 /* wait for other io to complete */
599 for (i = 0; i < nblks; i++) {
600 dmu_buf_impl_t *db = (dmu_buf_impl_t *)dbp[i];
601 mutex_enter(&db->db_mtx);
602 while (db->db_state == DB_READ ||
603 db->db_state == DB_FILL)
604 cv_wait(&db->db_changed, &db->db_mtx);
605 if (db->db_state == DB_UNCACHED)
606 err = SET_ERROR(EIO);
607 mutex_exit(&db->db_mtx);
608 if (err) {
609 dmu_buf_rele_array(dbp, nblks, tag);
610 return (err);
611 }
612 }
613 }
614
615 *numbufsp = nblks;
616 *dbpp = dbp;
617 return (0);
618 }
619
620 int
621 dmu_buf_hold_array(objset_t *os, uint64_t object, uint64_t offset,
622 uint64_t length, int read, void *tag, int *numbufsp, dmu_buf_t ***dbpp)
623 {
624 dnode_t *dn;
625 int err;
626
627 err = dnode_hold(os, object, FTAG, &dn);
628 if (err)
629 return (err);
630
631 err = dmu_buf_hold_array_by_dnode(dn, offset, length, read, tag,
632 numbufsp, dbpp, DMU_READ_PREFETCH);
633
634 dnode_rele(dn, FTAG);
635
636 return (err);
637 }
638
639 int
640 dmu_buf_hold_array_by_bonus(dmu_buf_t *db_fake, uint64_t offset,
641 uint64_t length, boolean_t read, void *tag, int *numbufsp,
642 dmu_buf_t ***dbpp)
643 {
644 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
645 dnode_t *dn;
646 int err;
647
648 DB_DNODE_ENTER(db);
649 dn = DB_DNODE(db);
650 err = dmu_buf_hold_array_by_dnode(dn, offset, length, read, tag,
651 numbufsp, dbpp, DMU_READ_PREFETCH);
652 DB_DNODE_EXIT(db);
653
654 return (err);
655 }
656
657 void
658 dmu_buf_rele_array(dmu_buf_t **dbp_fake, int numbufs, void *tag)
659 {
660 int i;
661 dmu_buf_impl_t **dbp = (dmu_buf_impl_t **)dbp_fake;
662
663 if (numbufs == 0)
664 return;
665
666 for (i = 0; i < numbufs; i++) {
667 if (dbp[i])
668 dbuf_rele(dbp[i], tag);
669 }
670
671 kmem_free(dbp, sizeof (dmu_buf_t *) * numbufs);
672 }
673
674 /*
675 * Issue prefetch i/os for the given blocks. If level is greater than 0, the
676 * indirect blocks prefetched will be those that point to the blocks containing
677 * the data starting at offset, and continuing to offset + len.
678 *
679 * Note that if the indirect blocks above the blocks being prefetched are not
680 * in cache, they will be asynchronously read in.
681 */
682 void
683 dmu_prefetch(objset_t *os, uint64_t object, int64_t level, uint64_t offset,
684 uint64_t len, zio_priority_t pri)
685 {
686 dnode_t *dn;
687 uint64_t blkid;
688 int nblks, err;
689
690 if (len == 0) { /* they're interested in the bonus buffer */
691 dn = DMU_META_DNODE(os);
692
693 if (object == 0 || object >= DN_MAX_OBJECT)
694 return;
695
696 rw_enter(&dn->dn_struct_rwlock, RW_READER);
697 blkid = dbuf_whichblock(dn, level,
698 object * sizeof (dnode_phys_t));
699 dbuf_prefetch(dn, level, blkid, pri, 0);
700 rw_exit(&dn->dn_struct_rwlock);
701 return;
702 }
703
704 /*
705 * See comment before the definition of dmu_prefetch_max.
706 */
707 len = MIN(len, dmu_prefetch_max);
708
709 /*
710 * XXX - Note, if the dnode for the requested object is not
711 * already cached, we will do a *synchronous* read in the
712 * dnode_hold() call. The same is true for any indirects.
713 */
714 err = dnode_hold(os, object, FTAG, &dn);
715 if (err != 0)
716 return;
717
718 /*
719 * offset + len - 1 is the last byte we want to prefetch for, and offset
720 * is the first. Then dbuf_whichblk(dn, level, off + len - 1) is the
721 * last block we want to prefetch, and dbuf_whichblock(dn, level,
722 * offset) is the first. Then the number we need to prefetch is the
723 * last - first + 1.
724 */
725 rw_enter(&dn->dn_struct_rwlock, RW_READER);
726 if (level > 0 || dn->dn_datablkshift != 0) {
727 nblks = dbuf_whichblock(dn, level, offset + len - 1) -
728 dbuf_whichblock(dn, level, offset) + 1;
729 } else {
730 nblks = (offset < dn->dn_datablksz);
731 }
732
733 if (nblks != 0) {
734 blkid = dbuf_whichblock(dn, level, offset);
735 for (int i = 0; i < nblks; i++)
736 dbuf_prefetch(dn, level, blkid + i, pri, 0);
737 }
738 rw_exit(&dn->dn_struct_rwlock);
739
740 dnode_rele(dn, FTAG);
741 }
742
743 /*
744 * Get the next "chunk" of file data to free. We traverse the file from
745 * the end so that the file gets shorter over time (if we crashes in the
746 * middle, this will leave us in a better state). We find allocated file
747 * data by simply searching the allocated level 1 indirects.
748 *
749 * On input, *start should be the first offset that does not need to be
750 * freed (e.g. "offset + length"). On return, *start will be the first
751 * offset that should be freed and l1blks is set to the number of level 1
752 * indirect blocks found within the chunk.
753 */
754 static int
755 get_next_chunk(dnode_t *dn, uint64_t *start, uint64_t minimum, uint64_t *l1blks)
756 {
757 uint64_t blks;
758 uint64_t maxblks = DMU_MAX_ACCESS >> (dn->dn_indblkshift + 1);
759 /* bytes of data covered by a level-1 indirect block */
760 uint64_t iblkrange = (uint64_t)dn->dn_datablksz *
761 EPB(dn->dn_indblkshift, SPA_BLKPTRSHIFT);
762
763 ASSERT3U(minimum, <=, *start);
764
765 /*
766 * Check if we can free the entire range assuming that all of the
767 * L1 blocks in this range have data. If we can, we use this
768 * worst case value as an estimate so we can avoid having to look
769 * at the object's actual data.
770 */
771 uint64_t total_l1blks =
772 (roundup(*start, iblkrange) - (minimum / iblkrange * iblkrange)) /
773 iblkrange;
774 if (total_l1blks <= maxblks) {
775 *l1blks = total_l1blks;
776 *start = minimum;
777 return (0);
778 }
779 ASSERT(ISP2(iblkrange));
780
781 for (blks = 0; *start > minimum && blks < maxblks; blks++) {
782 int err;
783
784 /*
785 * dnode_next_offset(BACKWARDS) will find an allocated L1
786 * indirect block at or before the input offset. We must
787 * decrement *start so that it is at the end of the region
788 * to search.
789 */
790 (*start)--;
791
792 err = dnode_next_offset(dn,
793 DNODE_FIND_BACKWARDS, start, 2, 1, 0);
794
795 /* if there are no indirect blocks before start, we are done */
796 if (err == ESRCH) {
797 *start = minimum;
798 break;
799 } else if (err != 0) {
800 *l1blks = blks;
801 return (err);
802 }
803
804 /* set start to the beginning of this L1 indirect */
805 *start = P2ALIGN(*start, iblkrange);
806 }
807 if (*start < minimum)
808 *start = minimum;
809 *l1blks = blks;
810
811 return (0);
812 }
813
814 /*
815 * If this objset is of type OST_ZFS return true if vfs's unmounted flag is set,
816 * otherwise return false.
817 * Used below in dmu_free_long_range_impl() to enable abort when unmounting
818 */
819 static boolean_t
820 dmu_objset_zfs_unmounting(objset_t *os)
821 {
822 #ifdef _KERNEL
823 if (dmu_objset_type(os) == DMU_OST_ZFS)
824 return (zfs_get_vfs_flag_unmounted(os));
825 #else
826 (void) os;
827 #endif
828 return (B_FALSE);
829 }
830
831 static int
832 dmu_free_long_range_impl(objset_t *os, dnode_t *dn, uint64_t offset,
833 uint64_t length)
834 {
835 uint64_t object_size;
836 int err;
837 uint64_t dirty_frees_threshold;
838 dsl_pool_t *dp = dmu_objset_pool(os);
839
840 if (dn == NULL)
841 return (SET_ERROR(EINVAL));
842
843 object_size = (dn->dn_maxblkid + 1) * dn->dn_datablksz;
844 if (offset >= object_size)
845 return (0);
846
847 if (zfs_per_txg_dirty_frees_percent <= 100)
848 dirty_frees_threshold =
849 zfs_per_txg_dirty_frees_percent * zfs_dirty_data_max / 100;
850 else
851 dirty_frees_threshold = zfs_dirty_data_max / 20;
852
853 if (length == DMU_OBJECT_END || offset + length > object_size)
854 length = object_size - offset;
855
856 while (length != 0) {
857 uint64_t chunk_end, chunk_begin, chunk_len;
858 uint64_t l1blks;
859 dmu_tx_t *tx;
860
861 if (dmu_objset_zfs_unmounting(dn->dn_objset))
862 return (SET_ERROR(EINTR));
863
864 chunk_end = chunk_begin = offset + length;
865
866 /* move chunk_begin backwards to the beginning of this chunk */
867 err = get_next_chunk(dn, &chunk_begin, offset, &l1blks);
868 if (err)
869 return (err);
870 ASSERT3U(chunk_begin, >=, offset);
871 ASSERT3U(chunk_begin, <=, chunk_end);
872
873 chunk_len = chunk_end - chunk_begin;
874
875 tx = dmu_tx_create(os);
876 dmu_tx_hold_free(tx, dn->dn_object, chunk_begin, chunk_len);
877
878 /*
879 * Mark this transaction as typically resulting in a net
880 * reduction in space used.
881 */
882 dmu_tx_mark_netfree(tx);
883 err = dmu_tx_assign(tx, TXG_WAIT);
884 if (err) {
885 dmu_tx_abort(tx);
886 return (err);
887 }
888
889 uint64_t txg = dmu_tx_get_txg(tx);
890
891 mutex_enter(&dp->dp_lock);
892 uint64_t long_free_dirty =
893 dp->dp_long_free_dirty_pertxg[txg & TXG_MASK];
894 mutex_exit(&dp->dp_lock);
895
896 /*
897 * To avoid filling up a TXG with just frees, wait for
898 * the next TXG to open before freeing more chunks if
899 * we have reached the threshold of frees.
900 */
901 if (dirty_frees_threshold != 0 &&
902 long_free_dirty >= dirty_frees_threshold) {
903 DMU_TX_STAT_BUMP(dmu_tx_dirty_frees_delay);
904 dmu_tx_commit(tx);
905 txg_wait_open(dp, 0, B_TRUE);
906 continue;
907 }
908
909 /*
910 * In order to prevent unnecessary write throttling, for each
911 * TXG, we track the cumulative size of L1 blocks being dirtied
912 * in dnode_free_range() below. We compare this number to a
913 * tunable threshold, past which we prevent new L1 dirty freeing
914 * blocks from being added into the open TXG. See
915 * dmu_free_long_range_impl() for details. The threshold
916 * prevents write throttle activation due to dirty freeing L1
917 * blocks taking up a large percentage of zfs_dirty_data_max.
918 */
919 mutex_enter(&dp->dp_lock);
920 dp->dp_long_free_dirty_pertxg[txg & TXG_MASK] +=
921 l1blks << dn->dn_indblkshift;
922 mutex_exit(&dp->dp_lock);
923 DTRACE_PROBE3(free__long__range,
924 uint64_t, long_free_dirty, uint64_t, chunk_len,
925 uint64_t, txg);
926 dnode_free_range(dn, chunk_begin, chunk_len, tx);
927
928 dmu_tx_commit(tx);
929
930 length -= chunk_len;
931 }
932 return (0);
933 }
934
935 int
936 dmu_free_long_range(objset_t *os, uint64_t object,
937 uint64_t offset, uint64_t length)
938 {
939 dnode_t *dn;
940 int err;
941
942 err = dnode_hold(os, object, FTAG, &dn);
943 if (err != 0)
944 return (err);
945 err = dmu_free_long_range_impl(os, dn, offset, length);
946
947 /*
948 * It is important to zero out the maxblkid when freeing the entire
949 * file, so that (a) subsequent calls to dmu_free_long_range_impl()
950 * will take the fast path, and (b) dnode_reallocate() can verify
951 * that the entire file has been freed.
952 */
953 if (err == 0 && offset == 0 && length == DMU_OBJECT_END)
954 dn->dn_maxblkid = 0;
955
956 dnode_rele(dn, FTAG);
957 return (err);
958 }
959
960 int
961 dmu_free_long_object(objset_t *os, uint64_t object)
962 {
963 dmu_tx_t *tx;
964 int err;
965
966 err = dmu_free_long_range(os, object, 0, DMU_OBJECT_END);
967 if (err != 0)
968 return (err);
969
970 tx = dmu_tx_create(os);
971 dmu_tx_hold_bonus(tx, object);
972 dmu_tx_hold_free(tx, object, 0, DMU_OBJECT_END);
973 dmu_tx_mark_netfree(tx);
974 err = dmu_tx_assign(tx, TXG_WAIT);
975 if (err == 0) {
976 err = dmu_object_free(os, object, tx);
977 dmu_tx_commit(tx);
978 } else {
979 dmu_tx_abort(tx);
980 }
981
982 return (err);
983 }
984
985 int
986 dmu_free_range(objset_t *os, uint64_t object, uint64_t offset,
987 uint64_t size, dmu_tx_t *tx)
988 {
989 dnode_t *dn;
990 int err = dnode_hold(os, object, FTAG, &dn);
991 if (err)
992 return (err);
993 ASSERT(offset < UINT64_MAX);
994 ASSERT(size == DMU_OBJECT_END || size <= UINT64_MAX - offset);
995 dnode_free_range(dn, offset, size, tx);
996 dnode_rele(dn, FTAG);
997 return (0);
998 }
999
1000 static int
1001 dmu_read_impl(dnode_t *dn, uint64_t offset, uint64_t size,
1002 void *buf, uint32_t flags)
1003 {
1004 dmu_buf_t **dbp;
1005 int numbufs, err = 0;
1006
1007 /*
1008 * Deal with odd block sizes, where there can't be data past the first
1009 * block. If we ever do the tail block optimization, we will need to
1010 * handle that here as well.
1011 */
1012 if (dn->dn_maxblkid == 0) {
1013 uint64_t newsz = offset > dn->dn_datablksz ? 0 :
1014 MIN(size, dn->dn_datablksz - offset);
1015 bzero((char *)buf + newsz, size - newsz);
1016 size = newsz;
1017 }
1018
1019 while (size > 0) {
1020 uint64_t mylen = MIN(size, DMU_MAX_ACCESS / 2);
1021 int i;
1022
1023 /*
1024 * NB: we could do this block-at-a-time, but it's nice
1025 * to be reading in parallel.
1026 */
1027 err = dmu_buf_hold_array_by_dnode(dn, offset, mylen,
1028 TRUE, FTAG, &numbufs, &dbp, flags);
1029 if (err)
1030 break;
1031
1032 for (i = 0; i < numbufs; i++) {
1033 uint64_t tocpy;
1034 int64_t bufoff;
1035 dmu_buf_t *db = dbp[i];
1036
1037 ASSERT(size > 0);
1038
1039 bufoff = offset - db->db_offset;
1040 tocpy = MIN(db->db_size - bufoff, size);
1041
1042 (void) memcpy(buf, (char *)db->db_data + bufoff, tocpy);
1043
1044 offset += tocpy;
1045 size -= tocpy;
1046 buf = (char *)buf + tocpy;
1047 }
1048 dmu_buf_rele_array(dbp, numbufs, FTAG);
1049 }
1050 return (err);
1051 }
1052
1053 int
1054 dmu_read(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
1055 void *buf, uint32_t flags)
1056 {
1057 dnode_t *dn;
1058 int err;
1059
1060 err = dnode_hold(os, object, FTAG, &dn);
1061 if (err != 0)
1062 return (err);
1063
1064 err = dmu_read_impl(dn, offset, size, buf, flags);
1065 dnode_rele(dn, FTAG);
1066 return (err);
1067 }
1068
1069 int
1070 dmu_read_by_dnode(dnode_t *dn, uint64_t offset, uint64_t size, void *buf,
1071 uint32_t flags)
1072 {
1073 return (dmu_read_impl(dn, offset, size, buf, flags));
1074 }
1075
1076 static void
1077 dmu_write_impl(dmu_buf_t **dbp, int numbufs, uint64_t offset, uint64_t size,
1078 const void *buf, dmu_tx_t *tx)
1079 {
1080 int i;
1081
1082 for (i = 0; i < numbufs; i++) {
1083 uint64_t tocpy;
1084 int64_t bufoff;
1085 dmu_buf_t *db = dbp[i];
1086
1087 ASSERT(size > 0);
1088
1089 bufoff = offset - db->db_offset;
1090 tocpy = MIN(db->db_size - bufoff, size);
1091
1092 ASSERT(i == 0 || i == numbufs-1 || tocpy == db->db_size);
1093
1094 if (tocpy == db->db_size)
1095 dmu_buf_will_fill(db, tx);
1096 else
1097 dmu_buf_will_dirty(db, tx);
1098
1099 (void) memcpy((char *)db->db_data + bufoff, buf, tocpy);
1100
1101 if (tocpy == db->db_size)
1102 dmu_buf_fill_done(db, tx);
1103
1104 offset += tocpy;
1105 size -= tocpy;
1106 buf = (char *)buf + tocpy;
1107 }
1108 }
1109
1110 void
1111 dmu_write(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
1112 const void *buf, dmu_tx_t *tx)
1113 {
1114 dmu_buf_t **dbp;
1115 int numbufs;
1116
1117 if (size == 0)
1118 return;
1119
1120 VERIFY0(dmu_buf_hold_array(os, object, offset, size,
1121 FALSE, FTAG, &numbufs, &dbp));
1122 dmu_write_impl(dbp, numbufs, offset, size, buf, tx);
1123 dmu_buf_rele_array(dbp, numbufs, FTAG);
1124 }
1125
1126 /*
1127 * Note: Lustre is an external consumer of this interface.
1128 */
1129 void
1130 dmu_write_by_dnode(dnode_t *dn, uint64_t offset, uint64_t size,
1131 const void *buf, dmu_tx_t *tx)
1132 {
1133 dmu_buf_t **dbp;
1134 int numbufs;
1135
1136 if (size == 0)
1137 return;
1138
1139 VERIFY0(dmu_buf_hold_array_by_dnode(dn, offset, size,
1140 FALSE, FTAG, &numbufs, &dbp, DMU_READ_PREFETCH));
1141 dmu_write_impl(dbp, numbufs, offset, size, buf, tx);
1142 dmu_buf_rele_array(dbp, numbufs, FTAG);
1143 }
1144
1145 void
1146 dmu_prealloc(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
1147 dmu_tx_t *tx)
1148 {
1149 dmu_buf_t **dbp;
1150 int numbufs, i;
1151
1152 if (size == 0)
1153 return;
1154
1155 VERIFY(0 == dmu_buf_hold_array(os, object, offset, size,
1156 FALSE, FTAG, &numbufs, &dbp));
1157
1158 for (i = 0; i < numbufs; i++) {
1159 dmu_buf_t *db = dbp[i];
1160
1161 dmu_buf_will_not_fill(db, tx);
1162 }
1163 dmu_buf_rele_array(dbp, numbufs, FTAG);
1164 }
1165
1166 void
1167 dmu_write_embedded(objset_t *os, uint64_t object, uint64_t offset,
1168 void *data, uint8_t etype, uint8_t comp, int uncompressed_size,
1169 int compressed_size, int byteorder, dmu_tx_t *tx)
1170 {
1171 dmu_buf_t *db;
1172
1173 ASSERT3U(etype, <, NUM_BP_EMBEDDED_TYPES);
1174 ASSERT3U(comp, <, ZIO_COMPRESS_FUNCTIONS);
1175 VERIFY0(dmu_buf_hold_noread(os, object, offset,
1176 FTAG, &db));
1177
1178 dmu_buf_write_embedded(db,
1179 data, (bp_embedded_type_t)etype, (enum zio_compress)comp,
1180 uncompressed_size, compressed_size, byteorder, tx);
1181
1182 dmu_buf_rele(db, FTAG);
1183 }
1184
1185 void
1186 dmu_redact(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
1187 dmu_tx_t *tx)
1188 {
1189 int numbufs, i;
1190 dmu_buf_t **dbp;
1191
1192 VERIFY0(dmu_buf_hold_array(os, object, offset, size, FALSE, FTAG,
1193 &numbufs, &dbp));
1194 for (i = 0; i < numbufs; i++)
1195 dmu_buf_redact(dbp[i], tx);
1196 dmu_buf_rele_array(dbp, numbufs, FTAG);
1197 }
1198
1199 #ifdef _KERNEL
1200 int
1201 dmu_read_uio_dnode(dnode_t *dn, zfs_uio_t *uio, uint64_t size)
1202 {
1203 dmu_buf_t **dbp;
1204 int numbufs, i, err;
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, zfs_uio_offset(uio), size,
1211 TRUE, FTAG, &numbufs, &dbp, 0);
1212 if (err)
1213 return (err);
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 = zfs_uio_offset(uio) - db->db_offset;
1223 tocpy = MIN(db->db_size - bufoff, size);
1224
1225 err = zfs_uio_fault_move((char *)db->db_data + bufoff, tocpy,
1226 UIO_READ, uio);
1227
1228 if (err)
1229 break;
1230
1231 size -= tocpy;
1232 }
1233 dmu_buf_rele_array(dbp, numbufs, FTAG);
1234
1235 return (err);
1236 }
1237
1238 /*
1239 * Read 'size' bytes into the uio buffer.
1240 * From object zdb->db_object.
1241 * Starting at zfs_uio_offset(uio).
1242 *
1243 * If the caller already has a dbuf in the target object
1244 * (e.g. its bonus buffer), this routine is faster than dmu_read_uio(),
1245 * because we don't have to find the dnode_t for the object.
1246 */
1247 int
1248 dmu_read_uio_dbuf(dmu_buf_t *zdb, zfs_uio_t *uio, uint64_t size)
1249 {
1250 dmu_buf_impl_t *db = (dmu_buf_impl_t *)zdb;
1251 dnode_t *dn;
1252 int err;
1253
1254 if (size == 0)
1255 return (0);
1256
1257 DB_DNODE_ENTER(db);
1258 dn = DB_DNODE(db);
1259 err = dmu_read_uio_dnode(dn, uio, size);
1260 DB_DNODE_EXIT(db);
1261
1262 return (err);
1263 }
1264
1265 /*
1266 * Read 'size' bytes into the uio buffer.
1267 * From the specified object
1268 * Starting at offset zfs_uio_offset(uio).
1269 */
1270 int
1271 dmu_read_uio(objset_t *os, uint64_t object, zfs_uio_t *uio, uint64_t size)
1272 {
1273 dnode_t *dn;
1274 int err;
1275
1276 if (size == 0)
1277 return (0);
1278
1279 err = dnode_hold(os, object, FTAG, &dn);
1280 if (err)
1281 return (err);
1282
1283 err = dmu_read_uio_dnode(dn, uio, size);
1284
1285 dnode_rele(dn, FTAG);
1286
1287 return (err);
1288 }
1289
1290 int
1291 dmu_write_uio_dnode(dnode_t *dn, zfs_uio_t *uio, uint64_t size, dmu_tx_t *tx)
1292 {
1293 dmu_buf_t **dbp;
1294 int numbufs;
1295 int err = 0;
1296 int i;
1297
1298 err = dmu_buf_hold_array_by_dnode(dn, zfs_uio_offset(uio), size,
1299 FALSE, FTAG, &numbufs, &dbp, DMU_READ_PREFETCH);
1300 if (err)
1301 return (err);
1302
1303 for (i = 0; i < numbufs; i++) {
1304 uint64_t tocpy;
1305 int64_t bufoff;
1306 dmu_buf_t *db = dbp[i];
1307
1308 ASSERT(size > 0);
1309
1310 bufoff = zfs_uio_offset(uio) - db->db_offset;
1311 tocpy = MIN(db->db_size - bufoff, size);
1312
1313 ASSERT(i == 0 || i == numbufs-1 || tocpy == db->db_size);
1314
1315 if (tocpy == db->db_size)
1316 dmu_buf_will_fill(db, tx);
1317 else
1318 dmu_buf_will_dirty(db, tx);
1319
1320 /*
1321 * XXX zfs_uiomove could block forever (eg.nfs-backed
1322 * pages). There needs to be a uiolockdown() function
1323 * to lock the pages in memory, so that zfs_uiomove won't
1324 * block.
1325 */
1326 err = zfs_uio_fault_move((char *)db->db_data + bufoff,
1327 tocpy, UIO_WRITE, uio);
1328
1329 if (tocpy == db->db_size)
1330 dmu_buf_fill_done(db, tx);
1331
1332 if (err)
1333 break;
1334
1335 size -= tocpy;
1336 }
1337
1338 dmu_buf_rele_array(dbp, numbufs, FTAG);
1339 return (err);
1340 }
1341
1342 /*
1343 * Write 'size' bytes from the uio buffer.
1344 * To object zdb->db_object.
1345 * Starting at offset zfs_uio_offset(uio).
1346 *
1347 * If the caller already has a dbuf in the target object
1348 * (e.g. its bonus buffer), this routine is faster than dmu_write_uio(),
1349 * because we don't have to find the dnode_t for the object.
1350 */
1351 int
1352 dmu_write_uio_dbuf(dmu_buf_t *zdb, zfs_uio_t *uio, uint64_t size,
1353 dmu_tx_t *tx)
1354 {
1355 dmu_buf_impl_t *db = (dmu_buf_impl_t *)zdb;
1356 dnode_t *dn;
1357 int err;
1358
1359 if (size == 0)
1360 return (0);
1361
1362 DB_DNODE_ENTER(db);
1363 dn = DB_DNODE(db);
1364 err = dmu_write_uio_dnode(dn, uio, size, tx);
1365 DB_DNODE_EXIT(db);
1366
1367 return (err);
1368 }
1369
1370 /*
1371 * Write 'size' bytes from the uio buffer.
1372 * To the specified object.
1373 * Starting at offset zfs_uio_offset(uio).
1374 */
1375 int
1376 dmu_write_uio(objset_t *os, uint64_t object, zfs_uio_t *uio, uint64_t size,
1377 dmu_tx_t *tx)
1378 {
1379 dnode_t *dn;
1380 int err;
1381
1382 if (size == 0)
1383 return (0);
1384
1385 err = dnode_hold(os, object, FTAG, &dn);
1386 if (err)
1387 return (err);
1388
1389 err = dmu_write_uio_dnode(dn, uio, size, tx);
1390
1391 dnode_rele(dn, FTAG);
1392
1393 return (err);
1394 }
1395 #endif /* _KERNEL */
1396
1397 /*
1398 * Allocate a loaned anonymous arc buffer.
1399 */
1400 arc_buf_t *
1401 dmu_request_arcbuf(dmu_buf_t *handle, int size)
1402 {
1403 dmu_buf_impl_t *db = (dmu_buf_impl_t *)handle;
1404
1405 return (arc_loan_buf(db->db_objset->os_spa, B_FALSE, size));
1406 }
1407
1408 /*
1409 * Free a loaned arc buffer.
1410 */
1411 void
1412 dmu_return_arcbuf(arc_buf_t *buf)
1413 {
1414 arc_return_buf(buf, FTAG);
1415 arc_buf_destroy(buf, FTAG);
1416 }
1417
1418 /*
1419 * A "lightweight" write is faster than a regular write (e.g.
1420 * dmu_write_by_dnode() or dmu_assign_arcbuf_by_dnode()), because it avoids the
1421 * CPU cost of creating a dmu_buf_impl_t and arc_buf_[hdr_]_t. However, the
1422 * data can not be read or overwritten until the transaction's txg has been
1423 * synced. This makes it appropriate for workloads that are known to be
1424 * (temporarily) write-only, like "zfs receive".
1425 *
1426 * A single block is written, starting at the specified offset in bytes. If
1427 * the call is successful, it returns 0 and the provided abd has been
1428 * consumed (the caller should not free it).
1429 */
1430 int
1431 dmu_lightweight_write_by_dnode(dnode_t *dn, uint64_t offset, abd_t *abd,
1432 const zio_prop_t *zp, enum zio_flag flags, dmu_tx_t *tx)
1433 {
1434 dbuf_dirty_record_t *dr =
1435 dbuf_dirty_lightweight(dn, dbuf_whichblock(dn, 0, offset), tx);
1436 if (dr == NULL)
1437 return (SET_ERROR(EIO));
1438 dr->dt.dll.dr_abd = abd;
1439 dr->dt.dll.dr_props = *zp;
1440 dr->dt.dll.dr_flags = flags;
1441 return (0);
1442 }
1443
1444 /*
1445 * When possible directly assign passed loaned arc buffer to a dbuf.
1446 * If this is not possible copy the contents of passed arc buf via
1447 * dmu_write().
1448 */
1449 int
1450 dmu_assign_arcbuf_by_dnode(dnode_t *dn, uint64_t offset, arc_buf_t *buf,
1451 dmu_tx_t *tx)
1452 {
1453 dmu_buf_impl_t *db;
1454 objset_t *os = dn->dn_objset;
1455 uint64_t object = dn->dn_object;
1456 uint32_t blksz = (uint32_t)arc_buf_lsize(buf);
1457 uint64_t blkid;
1458
1459 rw_enter(&dn->dn_struct_rwlock, RW_READER);
1460 blkid = dbuf_whichblock(dn, 0, offset);
1461 db = dbuf_hold(dn, blkid, FTAG);
1462 if (db == NULL)
1463 return (SET_ERROR(EIO));
1464 rw_exit(&dn->dn_struct_rwlock);
1465
1466 /*
1467 * We can only assign if the offset is aligned and the arc buf is the
1468 * same size as the dbuf.
1469 */
1470 if (offset == db->db.db_offset && blksz == db->db.db_size) {
1471 zfs_racct_write(blksz, 1);
1472 dbuf_assign_arcbuf(db, buf, tx);
1473 dbuf_rele(db, FTAG);
1474 } else {
1475 /* compressed bufs must always be assignable to their dbuf */
1476 ASSERT3U(arc_get_compression(buf), ==, ZIO_COMPRESS_OFF);
1477 ASSERT(!(buf->b_flags & ARC_BUF_FLAG_COMPRESSED));
1478
1479 dbuf_rele(db, FTAG);
1480 dmu_write(os, object, offset, blksz, buf->b_data, tx);
1481 dmu_return_arcbuf(buf);
1482 }
1483
1484 return (0);
1485 }
1486
1487 int
1488 dmu_assign_arcbuf_by_dbuf(dmu_buf_t *handle, uint64_t offset, arc_buf_t *buf,
1489 dmu_tx_t *tx)
1490 {
1491 int err;
1492 dmu_buf_impl_t *dbuf = (dmu_buf_impl_t *)handle;
1493
1494 DB_DNODE_ENTER(dbuf);
1495 err = dmu_assign_arcbuf_by_dnode(DB_DNODE(dbuf), offset, buf, tx);
1496 DB_DNODE_EXIT(dbuf);
1497
1498 return (err);
1499 }
1500
1501 typedef struct {
1502 dbuf_dirty_record_t *dsa_dr;
1503 dmu_sync_cb_t *dsa_done;
1504 zgd_t *dsa_zgd;
1505 dmu_tx_t *dsa_tx;
1506 } dmu_sync_arg_t;
1507
1508 static void
1509 dmu_sync_ready(zio_t *zio, arc_buf_t *buf, void *varg)
1510 {
1511 (void) buf;
1512 dmu_sync_arg_t *dsa = varg;
1513 dmu_buf_t *db = dsa->dsa_zgd->zgd_db;
1514 blkptr_t *bp = zio->io_bp;
1515
1516 if (zio->io_error == 0) {
1517 if (BP_IS_HOLE(bp)) {
1518 /*
1519 * A block of zeros may compress to a hole, but the
1520 * block size still needs to be known for replay.
1521 */
1522 BP_SET_LSIZE(bp, db->db_size);
1523 } else if (!BP_IS_EMBEDDED(bp)) {
1524 ASSERT(BP_GET_LEVEL(bp) == 0);
1525 BP_SET_FILL(bp, 1);
1526 }
1527 }
1528 }
1529
1530 static void
1531 dmu_sync_late_arrival_ready(zio_t *zio)
1532 {
1533 dmu_sync_ready(zio, NULL, zio->io_private);
1534 }
1535
1536 static void
1537 dmu_sync_done(zio_t *zio, arc_buf_t *buf, void *varg)
1538 {
1539 (void) buf;
1540 dmu_sync_arg_t *dsa = varg;
1541 dbuf_dirty_record_t *dr = dsa->dsa_dr;
1542 dmu_buf_impl_t *db = dr->dr_dbuf;
1543 zgd_t *zgd = dsa->dsa_zgd;
1544
1545 /*
1546 * Record the vdev(s) backing this blkptr so they can be flushed after
1547 * the writes for the lwb have completed.
1548 */
1549 if (zio->io_error == 0) {
1550 zil_lwb_add_block(zgd->zgd_lwb, zgd->zgd_bp);
1551 }
1552
1553 mutex_enter(&db->db_mtx);
1554 ASSERT(dr->dt.dl.dr_override_state == DR_IN_DMU_SYNC);
1555 if (zio->io_error == 0) {
1556 dr->dt.dl.dr_nopwrite = !!(zio->io_flags & ZIO_FLAG_NOPWRITE);
1557 if (dr->dt.dl.dr_nopwrite) {
1558 blkptr_t *bp = zio->io_bp;
1559 blkptr_t *bp_orig = &zio->io_bp_orig;
1560 uint8_t chksum = BP_GET_CHECKSUM(bp_orig);
1561
1562 ASSERT(BP_EQUAL(bp, bp_orig));
1563 VERIFY(BP_EQUAL(bp, db->db_blkptr));
1564 ASSERT(zio->io_prop.zp_compress != ZIO_COMPRESS_OFF);
1565 VERIFY(zio_checksum_table[chksum].ci_flags &
1566 ZCHECKSUM_FLAG_NOPWRITE);
1567 }
1568 dr->dt.dl.dr_overridden_by = *zio->io_bp;
1569 dr->dt.dl.dr_override_state = DR_OVERRIDDEN;
1570 dr->dt.dl.dr_copies = zio->io_prop.zp_copies;
1571
1572 /*
1573 * Old style holes are filled with all zeros, whereas
1574 * new-style holes maintain their lsize, type, level,
1575 * and birth time (see zio_write_compress). While we
1576 * need to reset the BP_SET_LSIZE() call that happened
1577 * in dmu_sync_ready for old style holes, we do *not*
1578 * want to wipe out the information contained in new
1579 * style holes. Thus, only zero out the block pointer if
1580 * it's an old style hole.
1581 */
1582 if (BP_IS_HOLE(&dr->dt.dl.dr_overridden_by) &&
1583 dr->dt.dl.dr_overridden_by.blk_birth == 0)
1584 BP_ZERO(&dr->dt.dl.dr_overridden_by);
1585 } else {
1586 dr->dt.dl.dr_override_state = DR_NOT_OVERRIDDEN;
1587 }
1588 cv_broadcast(&db->db_changed);
1589 mutex_exit(&db->db_mtx);
1590
1591 dsa->dsa_done(dsa->dsa_zgd, zio->io_error);
1592
1593 kmem_free(dsa, sizeof (*dsa));
1594 }
1595
1596 static void
1597 dmu_sync_late_arrival_done(zio_t *zio)
1598 {
1599 blkptr_t *bp = zio->io_bp;
1600 dmu_sync_arg_t *dsa = zio->io_private;
1601 zgd_t *zgd = dsa->dsa_zgd;
1602
1603 if (zio->io_error == 0) {
1604 /*
1605 * Record the vdev(s) backing this blkptr so they can be
1606 * flushed after the writes for the lwb have completed.
1607 */
1608 zil_lwb_add_block(zgd->zgd_lwb, zgd->zgd_bp);
1609
1610 if (!BP_IS_HOLE(bp)) {
1611 blkptr_t *bp_orig __maybe_unused = &zio->io_bp_orig;
1612 ASSERT(!(zio->io_flags & ZIO_FLAG_NOPWRITE));
1613 ASSERT(BP_IS_HOLE(bp_orig) || !BP_EQUAL(bp, bp_orig));
1614 ASSERT(zio->io_bp->blk_birth == zio->io_txg);
1615 ASSERT(zio->io_txg > spa_syncing_txg(zio->io_spa));
1616 zio_free(zio->io_spa, zio->io_txg, zio->io_bp);
1617 }
1618 }
1619
1620 dmu_tx_commit(dsa->dsa_tx);
1621
1622 dsa->dsa_done(dsa->dsa_zgd, zio->io_error);
1623
1624 abd_free(zio->io_abd);
1625 kmem_free(dsa, sizeof (*dsa));
1626 }
1627
1628 static int
1629 dmu_sync_late_arrival(zio_t *pio, objset_t *os, dmu_sync_cb_t *done, zgd_t *zgd,
1630 zio_prop_t *zp, zbookmark_phys_t *zb)
1631 {
1632 dmu_sync_arg_t *dsa;
1633 dmu_tx_t *tx;
1634
1635 tx = dmu_tx_create(os);
1636 dmu_tx_hold_space(tx, zgd->zgd_db->db_size);
1637 if (dmu_tx_assign(tx, TXG_WAIT) != 0) {
1638 dmu_tx_abort(tx);
1639 /* Make zl_get_data do txg_waited_synced() */
1640 return (SET_ERROR(EIO));
1641 }
1642
1643 /*
1644 * In order to prevent the zgd's lwb from being free'd prior to
1645 * dmu_sync_late_arrival_done() being called, we have to ensure
1646 * the lwb's "max txg" takes this tx's txg into account.
1647 */
1648 zil_lwb_add_txg(zgd->zgd_lwb, dmu_tx_get_txg(tx));
1649
1650 dsa = kmem_alloc(sizeof (dmu_sync_arg_t), KM_SLEEP);
1651 dsa->dsa_dr = NULL;
1652 dsa->dsa_done = done;
1653 dsa->dsa_zgd = zgd;
1654 dsa->dsa_tx = tx;
1655
1656 /*
1657 * Since we are currently syncing this txg, it's nontrivial to
1658 * determine what BP to nopwrite against, so we disable nopwrite.
1659 *
1660 * When syncing, the db_blkptr is initially the BP of the previous
1661 * txg. We can not nopwrite against it because it will be changed
1662 * (this is similar to the non-late-arrival case where the dbuf is
1663 * dirty in a future txg).
1664 *
1665 * Then dbuf_write_ready() sets bp_blkptr to the location we will write.
1666 * We can not nopwrite against it because although the BP will not
1667 * (typically) be changed, the data has not yet been persisted to this
1668 * location.
1669 *
1670 * Finally, when dbuf_write_done() is called, it is theoretically
1671 * possible to always nopwrite, because the data that was written in
1672 * this txg is the same data that we are trying to write. However we
1673 * would need to check that this dbuf is not dirty in any future
1674 * txg's (as we do in the normal dmu_sync() path). For simplicity, we
1675 * don't nopwrite in this case.
1676 */
1677 zp->zp_nopwrite = B_FALSE;
1678
1679 zio_nowait(zio_write(pio, os->os_spa, dmu_tx_get_txg(tx), zgd->zgd_bp,
1680 abd_get_from_buf(zgd->zgd_db->db_data, zgd->zgd_db->db_size),
1681 zgd->zgd_db->db_size, zgd->zgd_db->db_size, zp,
1682 dmu_sync_late_arrival_ready, NULL, NULL, dmu_sync_late_arrival_done,
1683 dsa, ZIO_PRIORITY_SYNC_WRITE, ZIO_FLAG_CANFAIL, zb));
1684
1685 return (0);
1686 }
1687
1688 /*
1689 * Intent log support: sync the block associated with db to disk.
1690 * N.B. and XXX: the caller is responsible for making sure that the
1691 * data isn't changing while dmu_sync() is writing it.
1692 *
1693 * Return values:
1694 *
1695 * EEXIST: this txg has already been synced, so there's nothing to do.
1696 * The caller should not log the write.
1697 *
1698 * ENOENT: the block was dbuf_free_range()'d, so there's nothing to do.
1699 * The caller should not log the write.
1700 *
1701 * EALREADY: this block is already in the process of being synced.
1702 * The caller should track its progress (somehow).
1703 *
1704 * EIO: could not do the I/O.
1705 * The caller should do a txg_wait_synced().
1706 *
1707 * 0: the I/O has been initiated.
1708 * The caller should log this blkptr in the done callback.
1709 * It is possible that the I/O will fail, in which case
1710 * the error will be reported to the done callback and
1711 * propagated to pio from zio_done().
1712 */
1713 int
1714 dmu_sync(zio_t *pio, uint64_t txg, dmu_sync_cb_t *done, zgd_t *zgd)
1715 {
1716 dmu_buf_impl_t *db = (dmu_buf_impl_t *)zgd->zgd_db;
1717 objset_t *os = db->db_objset;
1718 dsl_dataset_t *ds = os->os_dsl_dataset;
1719 dbuf_dirty_record_t *dr, *dr_next;
1720 dmu_sync_arg_t *dsa;
1721 zbookmark_phys_t zb;
1722 zio_prop_t zp;
1723 dnode_t *dn;
1724
1725 ASSERT(pio != NULL);
1726 ASSERT(txg != 0);
1727
1728 SET_BOOKMARK(&zb, ds->ds_object,
1729 db->db.db_object, db->db_level, db->db_blkid);
1730
1731 DB_DNODE_ENTER(db);
1732 dn = DB_DNODE(db);
1733 dmu_write_policy(os, dn, db->db_level, WP_DMU_SYNC, &zp);
1734 DB_DNODE_EXIT(db);
1735
1736 /*
1737 * If we're frozen (running ziltest), we always need to generate a bp.
1738 */
1739 if (txg > spa_freeze_txg(os->os_spa))
1740 return (dmu_sync_late_arrival(pio, os, done, zgd, &zp, &zb));
1741
1742 /*
1743 * Grabbing db_mtx now provides a barrier between dbuf_sync_leaf()
1744 * and us. If we determine that this txg is not yet syncing,
1745 * but it begins to sync a moment later, that's OK because the
1746 * sync thread will block in dbuf_sync_leaf() until we drop db_mtx.
1747 */
1748 mutex_enter(&db->db_mtx);
1749
1750 if (txg <= spa_last_synced_txg(os->os_spa)) {
1751 /*
1752 * This txg has already synced. There's nothing to do.
1753 */
1754 mutex_exit(&db->db_mtx);
1755 return (SET_ERROR(EEXIST));
1756 }
1757
1758 if (txg <= spa_syncing_txg(os->os_spa)) {
1759 /*
1760 * This txg is currently syncing, so we can't mess with
1761 * the dirty record anymore; just write a new log block.
1762 */
1763 mutex_exit(&db->db_mtx);
1764 return (dmu_sync_late_arrival(pio, os, done, zgd, &zp, &zb));
1765 }
1766
1767 dr = dbuf_find_dirty_eq(db, txg);
1768
1769 if (dr == NULL) {
1770 /*
1771 * There's no dr for this dbuf, so it must have been freed.
1772 * There's no need to log writes to freed blocks, so we're done.
1773 */
1774 mutex_exit(&db->db_mtx);
1775 return (SET_ERROR(ENOENT));
1776 }
1777
1778 dr_next = list_next(&db->db_dirty_records, dr);
1779 ASSERT(dr_next == NULL || dr_next->dr_txg < txg);
1780
1781 if (db->db_blkptr != NULL) {
1782 /*
1783 * We need to fill in zgd_bp with the current blkptr so that
1784 * the nopwrite code can check if we're writing the same
1785 * data that's already on disk. We can only nopwrite if we
1786 * are sure that after making the copy, db_blkptr will not
1787 * change until our i/o completes. We ensure this by
1788 * holding the db_mtx, and only allowing nopwrite if the
1789 * block is not already dirty (see below). This is verified
1790 * by dmu_sync_done(), which VERIFYs that the db_blkptr has
1791 * not changed.
1792 */
1793 *zgd->zgd_bp = *db->db_blkptr;
1794 }
1795
1796 /*
1797 * Assume the on-disk data is X, the current syncing data (in
1798 * txg - 1) is Y, and the current in-memory data is Z (currently
1799 * in dmu_sync).
1800 *
1801 * We usually want to perform a nopwrite if X and Z are the
1802 * same. However, if Y is different (i.e. the BP is going to
1803 * change before this write takes effect), then a nopwrite will
1804 * be incorrect - we would override with X, which could have
1805 * been freed when Y was written.
1806 *
1807 * (Note that this is not a concern when we are nop-writing from
1808 * syncing context, because X and Y must be identical, because
1809 * all previous txgs have been synced.)
1810 *
1811 * Therefore, we disable nopwrite if the current BP could change
1812 * before this TXG. There are two ways it could change: by
1813 * being dirty (dr_next is non-NULL), or by being freed
1814 * (dnode_block_freed()). This behavior is verified by
1815 * zio_done(), which VERIFYs that the override BP is identical
1816 * to the on-disk BP.
1817 */
1818 DB_DNODE_ENTER(db);
1819 dn = DB_DNODE(db);
1820 if (dr_next != NULL || dnode_block_freed(dn, db->db_blkid))
1821 zp.zp_nopwrite = B_FALSE;
1822 DB_DNODE_EXIT(db);
1823
1824 ASSERT(dr->dr_txg == txg);
1825 if (dr->dt.dl.dr_override_state == DR_IN_DMU_SYNC ||
1826 dr->dt.dl.dr_override_state == DR_OVERRIDDEN) {
1827 /*
1828 * We have already issued a sync write for this buffer,
1829 * or this buffer has already been synced. It could not
1830 * have been dirtied since, or we would have cleared the state.
1831 */
1832 mutex_exit(&db->db_mtx);
1833 return (SET_ERROR(EALREADY));
1834 }
1835
1836 ASSERT(dr->dt.dl.dr_override_state == DR_NOT_OVERRIDDEN);
1837 dr->dt.dl.dr_override_state = DR_IN_DMU_SYNC;
1838 mutex_exit(&db->db_mtx);
1839
1840 dsa = kmem_alloc(sizeof (dmu_sync_arg_t), KM_SLEEP);
1841 dsa->dsa_dr = dr;
1842 dsa->dsa_done = done;
1843 dsa->dsa_zgd = zgd;
1844 dsa->dsa_tx = NULL;
1845
1846 zio_nowait(arc_write(pio, os->os_spa, txg,
1847 zgd->zgd_bp, dr->dt.dl.dr_data, dbuf_is_l2cacheable(db),
1848 &zp, dmu_sync_ready, NULL, NULL, dmu_sync_done, dsa,
1849 ZIO_PRIORITY_SYNC_WRITE, ZIO_FLAG_CANFAIL, &zb));
1850
1851 return (0);
1852 }
1853
1854 int
1855 dmu_object_set_nlevels(objset_t *os, uint64_t object, int nlevels, dmu_tx_t *tx)
1856 {
1857 dnode_t *dn;
1858 int err;
1859
1860 err = dnode_hold(os, object, FTAG, &dn);
1861 if (err)
1862 return (err);
1863 err = dnode_set_nlevels(dn, nlevels, tx);
1864 dnode_rele(dn, FTAG);
1865 return (err);
1866 }
1867
1868 int
1869 dmu_object_set_blocksize(objset_t *os, uint64_t object, uint64_t size, int ibs,
1870 dmu_tx_t *tx)
1871 {
1872 dnode_t *dn;
1873 int err;
1874
1875 err = dnode_hold(os, object, FTAG, &dn);
1876 if (err)
1877 return (err);
1878 err = dnode_set_blksz(dn, size, ibs, tx);
1879 dnode_rele(dn, FTAG);
1880 return (err);
1881 }
1882
1883 int
1884 dmu_object_set_maxblkid(objset_t *os, uint64_t object, uint64_t maxblkid,
1885 dmu_tx_t *tx)
1886 {
1887 dnode_t *dn;
1888 int err;
1889
1890 err = dnode_hold(os, object, FTAG, &dn);
1891 if (err)
1892 return (err);
1893 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
1894 dnode_new_blkid(dn, maxblkid, tx, B_FALSE, B_TRUE);
1895 rw_exit(&dn->dn_struct_rwlock);
1896 dnode_rele(dn, FTAG);
1897 return (0);
1898 }
1899
1900 void
1901 dmu_object_set_checksum(objset_t *os, uint64_t object, uint8_t checksum,
1902 dmu_tx_t *tx)
1903 {
1904 dnode_t *dn;
1905
1906 /*
1907 * Send streams include each object's checksum function. This
1908 * check ensures that the receiving system can understand the
1909 * checksum function transmitted.
1910 */
1911 ASSERT3U(checksum, <, ZIO_CHECKSUM_LEGACY_FUNCTIONS);
1912
1913 VERIFY0(dnode_hold(os, object, FTAG, &dn));
1914 ASSERT3U(checksum, <, ZIO_CHECKSUM_FUNCTIONS);
1915 dn->dn_checksum = checksum;
1916 dnode_setdirty(dn, tx);
1917 dnode_rele(dn, FTAG);
1918 }
1919
1920 void
1921 dmu_object_set_compress(objset_t *os, uint64_t object, uint8_t compress,
1922 dmu_tx_t *tx)
1923 {
1924 dnode_t *dn;
1925
1926 /*
1927 * Send streams include each object's compression function. This
1928 * check ensures that the receiving system can understand the
1929 * compression function transmitted.
1930 */
1931 ASSERT3U(compress, <, ZIO_COMPRESS_LEGACY_FUNCTIONS);
1932
1933 VERIFY0(dnode_hold(os, object, FTAG, &dn));
1934 dn->dn_compress = compress;
1935 dnode_setdirty(dn, tx);
1936 dnode_rele(dn, FTAG);
1937 }
1938
1939 /*
1940 * When the "redundant_metadata" property is set to "most", only indirect
1941 * blocks of this level and higher will have an additional ditto block.
1942 */
1943 static const int zfs_redundant_metadata_most_ditto_level = 2;
1944
1945 void
1946 dmu_write_policy(objset_t *os, dnode_t *dn, int level, int wp, zio_prop_t *zp)
1947 {
1948 dmu_object_type_t type = dn ? dn->dn_type : DMU_OT_OBJSET;
1949 boolean_t ismd = (level > 0 || DMU_OT_IS_METADATA(type) ||
1950 (wp & WP_SPILL));
1951 enum zio_checksum checksum = os->os_checksum;
1952 enum zio_compress compress = os->os_compress;
1953 uint8_t complevel = os->os_complevel;
1954 enum zio_checksum dedup_checksum = os->os_dedup_checksum;
1955 boolean_t dedup = B_FALSE;
1956 boolean_t nopwrite = B_FALSE;
1957 boolean_t dedup_verify = os->os_dedup_verify;
1958 boolean_t encrypt = B_FALSE;
1959 int copies = os->os_copies;
1960
1961 /*
1962 * We maintain different write policies for each of the following
1963 * types of data:
1964 * 1. metadata
1965 * 2. preallocated blocks (i.e. level-0 blocks of a dump device)
1966 * 3. all other level 0 blocks
1967 */
1968 if (ismd) {
1969 /*
1970 * XXX -- we should design a compression algorithm
1971 * that specializes in arrays of bps.
1972 */
1973 compress = zio_compress_select(os->os_spa,
1974 ZIO_COMPRESS_ON, ZIO_COMPRESS_ON);
1975
1976 /*
1977 * Metadata always gets checksummed. If the data
1978 * checksum is multi-bit correctable, and it's not a
1979 * ZBT-style checksum, then it's suitable for metadata
1980 * as well. Otherwise, the metadata checksum defaults
1981 * to fletcher4.
1982 */
1983 if (!(zio_checksum_table[checksum].ci_flags &
1984 ZCHECKSUM_FLAG_METADATA) ||
1985 (zio_checksum_table[checksum].ci_flags &
1986 ZCHECKSUM_FLAG_EMBEDDED))
1987 checksum = ZIO_CHECKSUM_FLETCHER_4;
1988
1989 if (os->os_redundant_metadata == ZFS_REDUNDANT_METADATA_ALL ||
1990 (os->os_redundant_metadata ==
1991 ZFS_REDUNDANT_METADATA_MOST &&
1992 (level >= zfs_redundant_metadata_most_ditto_level ||
1993 DMU_OT_IS_METADATA(type) || (wp & WP_SPILL))))
1994 copies++;
1995 } else if (wp & WP_NOFILL) {
1996 ASSERT(level == 0);
1997
1998 /*
1999 * If we're writing preallocated blocks, we aren't actually
2000 * writing them so don't set any policy properties. These
2001 * blocks are currently only used by an external subsystem
2002 * outside of zfs (i.e. dump) and not written by the zio
2003 * pipeline.
2004 */
2005 compress = ZIO_COMPRESS_OFF;
2006 checksum = ZIO_CHECKSUM_OFF;
2007 } else {
2008 compress = zio_compress_select(os->os_spa, dn->dn_compress,
2009 compress);
2010 complevel = zio_complevel_select(os->os_spa, compress,
2011 complevel, complevel);
2012
2013 checksum = (dedup_checksum == ZIO_CHECKSUM_OFF) ?
2014 zio_checksum_select(dn->dn_checksum, checksum) :
2015 dedup_checksum;
2016
2017 /*
2018 * Determine dedup setting. If we are in dmu_sync(),
2019 * we won't actually dedup now because that's all
2020 * done in syncing context; but we do want to use the
2021 * dedup checksum. If the checksum is not strong
2022 * enough to ensure unique signatures, force
2023 * dedup_verify.
2024 */
2025 if (dedup_checksum != ZIO_CHECKSUM_OFF) {
2026 dedup = (wp & WP_DMU_SYNC) ? B_FALSE : B_TRUE;
2027 if (!(zio_checksum_table[checksum].ci_flags &
2028 ZCHECKSUM_FLAG_DEDUP))
2029 dedup_verify = B_TRUE;
2030 }
2031
2032 /*
2033 * Enable nopwrite if we have secure enough checksum
2034 * algorithm (see comment in zio_nop_write) and
2035 * compression is enabled. We don't enable nopwrite if
2036 * dedup is enabled as the two features are mutually
2037 * exclusive.
2038 */
2039 nopwrite = (!dedup && (zio_checksum_table[checksum].ci_flags &
2040 ZCHECKSUM_FLAG_NOPWRITE) &&
2041 compress != ZIO_COMPRESS_OFF && zfs_nopwrite_enabled);
2042 }
2043
2044 /*
2045 * All objects in an encrypted objset are protected from modification
2046 * via a MAC. Encrypted objects store their IV and salt in the last DVA
2047 * in the bp, so we cannot use all copies. Encrypted objects are also
2048 * not subject to nopwrite since writing the same data will still
2049 * result in a new ciphertext. Only encrypted blocks can be dedup'd
2050 * to avoid ambiguity in the dedup code since the DDT does not store
2051 * object types.
2052 */
2053 if (os->os_encrypted && (wp & WP_NOFILL) == 0) {
2054 encrypt = B_TRUE;
2055
2056 if (DMU_OT_IS_ENCRYPTED(type)) {
2057 copies = MIN(copies, SPA_DVAS_PER_BP - 1);
2058 nopwrite = B_FALSE;
2059 } else {
2060 dedup = B_FALSE;
2061 }
2062
2063 if (level <= 0 &&
2064 (type == DMU_OT_DNODE || type == DMU_OT_OBJSET)) {
2065 compress = ZIO_COMPRESS_EMPTY;
2066 }
2067 }
2068
2069 zp->zp_compress = compress;
2070 zp->zp_complevel = complevel;
2071 zp->zp_checksum = checksum;
2072 zp->zp_type = (wp & WP_SPILL) ? dn->dn_bonustype : type;
2073 zp->zp_level = level;
2074 zp->zp_copies = MIN(copies, spa_max_replication(os->os_spa));
2075 zp->zp_dedup = dedup;
2076 zp->zp_dedup_verify = dedup && dedup_verify;
2077 zp->zp_nopwrite = nopwrite;
2078 zp->zp_encrypt = encrypt;
2079 zp->zp_byteorder = ZFS_HOST_BYTEORDER;
2080 bzero(zp->zp_salt, ZIO_DATA_SALT_LEN);
2081 bzero(zp->zp_iv, ZIO_DATA_IV_LEN);
2082 bzero(zp->zp_mac, ZIO_DATA_MAC_LEN);
2083 zp->zp_zpl_smallblk = DMU_OT_IS_FILE(zp->zp_type) ?
2084 os->os_zpl_special_smallblock : 0;
2085
2086 ASSERT3U(zp->zp_compress, !=, ZIO_COMPRESS_INHERIT);
2087 }
2088
2089 /*
2090 * This function is only called from zfs_holey_common() for zpl_llseek()
2091 * in order to determine the location of holes. In order to accurately
2092 * report holes all dirty data must be synced to disk. This causes extremely
2093 * poor performance when seeking for holes in a dirty file. As a compromise,
2094 * only provide hole data when the dnode is clean. When a dnode is dirty
2095 * report the dnode as having no holes which is always a safe thing to do.
2096 */
2097 int
2098 dmu_offset_next(objset_t *os, uint64_t object, boolean_t hole, uint64_t *off)
2099 {
2100 dnode_t *dn;
2101 int err;
2102
2103 restart:
2104 err = dnode_hold(os, object, FTAG, &dn);
2105 if (err)
2106 return (err);
2107
2108 rw_enter(&dn->dn_struct_rwlock, RW_READER);
2109
2110 if (dnode_is_dirty(dn)) {
2111 /*
2112 * If the zfs_dmu_offset_next_sync module option is enabled
2113 * then strict hole reporting has been requested. Dirty
2114 * dnodes must be synced to disk to accurately report all
2115 * holes. When disabled dirty dnodes are reported to not
2116 * have any holes which is always safe.
2117 *
2118 * When called by zfs_holey_common() the zp->z_rangelock
2119 * is held to prevent zfs_write() and mmap writeback from
2120 * re-dirtying the dnode after txg_wait_synced().
2121 */
2122 if (zfs_dmu_offset_next_sync) {
2123 rw_exit(&dn->dn_struct_rwlock);
2124 dnode_rele(dn, FTAG);
2125 txg_wait_synced(dmu_objset_pool(os), 0);
2126 goto restart;
2127 }
2128
2129 err = SET_ERROR(EBUSY);
2130 } else {
2131 err = dnode_next_offset(dn, DNODE_FIND_HAVELOCK |
2132 (hole ? DNODE_FIND_HOLE : 0), off, 1, 1, 0);
2133 }
2134
2135 rw_exit(&dn->dn_struct_rwlock);
2136 dnode_rele(dn, FTAG);
2137
2138 return (err);
2139 }
2140
2141 void
2142 __dmu_object_info_from_dnode(dnode_t *dn, dmu_object_info_t *doi)
2143 {
2144 dnode_phys_t *dnp = dn->dn_phys;
2145
2146 doi->doi_data_block_size = dn->dn_datablksz;
2147 doi->doi_metadata_block_size = dn->dn_indblkshift ?
2148 1ULL << dn->dn_indblkshift : 0;
2149 doi->doi_type = dn->dn_type;
2150 doi->doi_bonus_type = dn->dn_bonustype;
2151 doi->doi_bonus_size = dn->dn_bonuslen;
2152 doi->doi_dnodesize = dn->dn_num_slots << DNODE_SHIFT;
2153 doi->doi_indirection = dn->dn_nlevels;
2154 doi->doi_checksum = dn->dn_checksum;
2155 doi->doi_compress = dn->dn_compress;
2156 doi->doi_nblkptr = dn->dn_nblkptr;
2157 doi->doi_physical_blocks_512 = (DN_USED_BYTES(dnp) + 256) >> 9;
2158 doi->doi_max_offset = (dn->dn_maxblkid + 1) * dn->dn_datablksz;
2159 doi->doi_fill_count = 0;
2160 for (int i = 0; i < dnp->dn_nblkptr; i++)
2161 doi->doi_fill_count += BP_GET_FILL(&dnp->dn_blkptr[i]);
2162 }
2163
2164 void
2165 dmu_object_info_from_dnode(dnode_t *dn, dmu_object_info_t *doi)
2166 {
2167 rw_enter(&dn->dn_struct_rwlock, RW_READER);
2168 mutex_enter(&dn->dn_mtx);
2169
2170 __dmu_object_info_from_dnode(dn, doi);
2171
2172 mutex_exit(&dn->dn_mtx);
2173 rw_exit(&dn->dn_struct_rwlock);
2174 }
2175
2176 /*
2177 * Get information on a DMU object.
2178 * If doi is NULL, just indicates whether the object exists.
2179 */
2180 int
2181 dmu_object_info(objset_t *os, uint64_t object, dmu_object_info_t *doi)
2182 {
2183 dnode_t *dn;
2184 int err = dnode_hold(os, object, FTAG, &dn);
2185
2186 if (err)
2187 return (err);
2188
2189 if (doi != NULL)
2190 dmu_object_info_from_dnode(dn, doi);
2191
2192 dnode_rele(dn, FTAG);
2193 return (0);
2194 }
2195
2196 /*
2197 * As above, but faster; can be used when you have a held dbuf in hand.
2198 */
2199 void
2200 dmu_object_info_from_db(dmu_buf_t *db_fake, dmu_object_info_t *doi)
2201 {
2202 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
2203
2204 DB_DNODE_ENTER(db);
2205 dmu_object_info_from_dnode(DB_DNODE(db), doi);
2206 DB_DNODE_EXIT(db);
2207 }
2208
2209 /*
2210 * Faster still when you only care about the size.
2211 */
2212 void
2213 dmu_object_size_from_db(dmu_buf_t *db_fake, uint32_t *blksize,
2214 u_longlong_t *nblk512)
2215 {
2216 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
2217 dnode_t *dn;
2218
2219 DB_DNODE_ENTER(db);
2220 dn = DB_DNODE(db);
2221
2222 *blksize = dn->dn_datablksz;
2223 /* add in number of slots used for the dnode itself */
2224 *nblk512 = ((DN_USED_BYTES(dn->dn_phys) + SPA_MINBLOCKSIZE/2) >>
2225 SPA_MINBLOCKSHIFT) + dn->dn_num_slots;
2226 DB_DNODE_EXIT(db);
2227 }
2228
2229 void
2230 dmu_object_dnsize_from_db(dmu_buf_t *db_fake, int *dnsize)
2231 {
2232 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
2233 dnode_t *dn;
2234
2235 DB_DNODE_ENTER(db);
2236 dn = DB_DNODE(db);
2237 *dnsize = dn->dn_num_slots << DNODE_SHIFT;
2238 DB_DNODE_EXIT(db);
2239 }
2240
2241 void
2242 byteswap_uint64_array(void *vbuf, size_t size)
2243 {
2244 uint64_t *buf = vbuf;
2245 size_t count = size >> 3;
2246 int i;
2247
2248 ASSERT((size & 7) == 0);
2249
2250 for (i = 0; i < count; i++)
2251 buf[i] = BSWAP_64(buf[i]);
2252 }
2253
2254 void
2255 byteswap_uint32_array(void *vbuf, size_t size)
2256 {
2257 uint32_t *buf = vbuf;
2258 size_t count = size >> 2;
2259 int i;
2260
2261 ASSERT((size & 3) == 0);
2262
2263 for (i = 0; i < count; i++)
2264 buf[i] = BSWAP_32(buf[i]);
2265 }
2266
2267 void
2268 byteswap_uint16_array(void *vbuf, size_t size)
2269 {
2270 uint16_t *buf = vbuf;
2271 size_t count = size >> 1;
2272 int i;
2273
2274 ASSERT((size & 1) == 0);
2275
2276 for (i = 0; i < count; i++)
2277 buf[i] = BSWAP_16(buf[i]);
2278 }
2279
2280 void
2281 byteswap_uint8_array(void *vbuf, size_t size)
2282 {
2283 (void) vbuf, (void) size;
2284 }
2285
2286 void
2287 dmu_init(void)
2288 {
2289 abd_init();
2290 zfs_dbgmsg_init();
2291 sa_cache_init();
2292 dmu_objset_init();
2293 dnode_init();
2294 zfetch_init();
2295 dmu_tx_init();
2296 l2arc_init();
2297 arc_init();
2298 dbuf_init();
2299 }
2300
2301 void
2302 dmu_fini(void)
2303 {
2304 arc_fini(); /* arc depends on l2arc, so arc must go first */
2305 l2arc_fini();
2306 dmu_tx_fini();
2307 zfetch_fini();
2308 dbuf_fini();
2309 dnode_fini();
2310 dmu_objset_fini();
2311 sa_cache_fini();
2312 zfs_dbgmsg_fini();
2313 abd_fini();
2314 }
2315
2316 EXPORT_SYMBOL(dmu_bonus_hold);
2317 EXPORT_SYMBOL(dmu_bonus_hold_by_dnode);
2318 EXPORT_SYMBOL(dmu_buf_hold_array_by_bonus);
2319 EXPORT_SYMBOL(dmu_buf_rele_array);
2320 EXPORT_SYMBOL(dmu_prefetch);
2321 EXPORT_SYMBOL(dmu_free_range);
2322 EXPORT_SYMBOL(dmu_free_long_range);
2323 EXPORT_SYMBOL(dmu_free_long_object);
2324 EXPORT_SYMBOL(dmu_read);
2325 EXPORT_SYMBOL(dmu_read_by_dnode);
2326 EXPORT_SYMBOL(dmu_write);
2327 EXPORT_SYMBOL(dmu_write_by_dnode);
2328 EXPORT_SYMBOL(dmu_prealloc);
2329 EXPORT_SYMBOL(dmu_object_info);
2330 EXPORT_SYMBOL(dmu_object_info_from_dnode);
2331 EXPORT_SYMBOL(dmu_object_info_from_db);
2332 EXPORT_SYMBOL(dmu_object_size_from_db);
2333 EXPORT_SYMBOL(dmu_object_dnsize_from_db);
2334 EXPORT_SYMBOL(dmu_object_set_nlevels);
2335 EXPORT_SYMBOL(dmu_object_set_blocksize);
2336 EXPORT_SYMBOL(dmu_object_set_maxblkid);
2337 EXPORT_SYMBOL(dmu_object_set_checksum);
2338 EXPORT_SYMBOL(dmu_object_set_compress);
2339 EXPORT_SYMBOL(dmu_offset_next);
2340 EXPORT_SYMBOL(dmu_write_policy);
2341 EXPORT_SYMBOL(dmu_sync);
2342 EXPORT_SYMBOL(dmu_request_arcbuf);
2343 EXPORT_SYMBOL(dmu_return_arcbuf);
2344 EXPORT_SYMBOL(dmu_assign_arcbuf_by_dnode);
2345 EXPORT_SYMBOL(dmu_assign_arcbuf_by_dbuf);
2346 EXPORT_SYMBOL(dmu_buf_hold);
2347 EXPORT_SYMBOL(dmu_ot);
2348
2349 /* BEGIN CSTYLED */
2350 ZFS_MODULE_PARAM(zfs, zfs_, nopwrite_enabled, INT, ZMOD_RW,
2351 "Enable NOP writes");
2352
2353 ZFS_MODULE_PARAM(zfs, zfs_, per_txg_dirty_frees_percent, ULONG, ZMOD_RW,
2354 "Percentage of dirtied blocks from frees in one TXG");
2355
2356 ZFS_MODULE_PARAM(zfs, zfs_, dmu_offset_next_sync, INT, ZMOD_RW,
2357 "Enable forcing txg sync to find holes");
2358
2359 ZFS_MODULE_PARAM(zfs, , dmu_prefetch_max, INT, ZMOD_RW,
2360 "Limit one prefetch call to this size");
2361 /* END CSTYLED */
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