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OpenZFS 7301 - zpool export -f should be able to interrupt file freeing
[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, 2016 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 */
29
30 #include <sys/dmu.h>
31 #include <sys/dmu_impl.h>
32 #include <sys/dmu_tx.h>
33 #include <sys/dbuf.h>
34 #include <sys/dnode.h>
35 #include <sys/zfs_context.h>
36 #include <sys/dmu_objset.h>
37 #include <sys/dmu_traverse.h>
38 #include <sys/dsl_dataset.h>
39 #include <sys/dsl_dir.h>
40 #include <sys/dsl_pool.h>
41 #include <sys/dsl_synctask.h>
42 #include <sys/dsl_prop.h>
43 #include <sys/dmu_zfetch.h>
44 #include <sys/zfs_ioctl.h>
45 #include <sys/zap.h>
46 #include <sys/zio_checksum.h>
47 #include <sys/zio_compress.h>
48 #include <sys/sa.h>
49 #include <sys/zfeature.h>
50 #include <sys/abd.h>
51 #ifdef _KERNEL
52 #include <sys/vmsystm.h>
53 #include <sys/zfs_znode.h>
54 #endif
55
56 /*
57 * Enable/disable nopwrite feature.
58 */
59 int zfs_nopwrite_enabled = 1;
60
61 const dmu_object_type_info_t dmu_ot[DMU_OT_NUMTYPES] = {
62 { DMU_BSWAP_UINT8, TRUE, "unallocated" },
63 { DMU_BSWAP_ZAP, TRUE, "object directory" },
64 { DMU_BSWAP_UINT64, TRUE, "object array" },
65 { DMU_BSWAP_UINT8, TRUE, "packed nvlist" },
66 { DMU_BSWAP_UINT64, TRUE, "packed nvlist size" },
67 { DMU_BSWAP_UINT64, TRUE, "bpobj" },
68 { DMU_BSWAP_UINT64, TRUE, "bpobj header" },
69 { DMU_BSWAP_UINT64, TRUE, "SPA space map header" },
70 { DMU_BSWAP_UINT64, TRUE, "SPA space map" },
71 { DMU_BSWAP_UINT64, TRUE, "ZIL intent log" },
72 { DMU_BSWAP_DNODE, TRUE, "DMU dnode" },
73 { DMU_BSWAP_OBJSET, TRUE, "DMU objset" },
74 { DMU_BSWAP_UINT64, TRUE, "DSL directory" },
75 { DMU_BSWAP_ZAP, TRUE, "DSL directory child map"},
76 { DMU_BSWAP_ZAP, TRUE, "DSL dataset snap map" },
77 { DMU_BSWAP_ZAP, TRUE, "DSL props" },
78 { DMU_BSWAP_UINT64, TRUE, "DSL dataset" },
79 { DMU_BSWAP_ZNODE, TRUE, "ZFS znode" },
80 { DMU_BSWAP_OLDACL, TRUE, "ZFS V0 ACL" },
81 { DMU_BSWAP_UINT8, FALSE, "ZFS plain file" },
82 { DMU_BSWAP_ZAP, TRUE, "ZFS directory" },
83 { DMU_BSWAP_ZAP, TRUE, "ZFS master node" },
84 { DMU_BSWAP_ZAP, TRUE, "ZFS delete queue" },
85 { DMU_BSWAP_UINT8, FALSE, "zvol object" },
86 { DMU_BSWAP_ZAP, TRUE, "zvol prop" },
87 { DMU_BSWAP_UINT8, FALSE, "other uint8[]" },
88 { DMU_BSWAP_UINT64, FALSE, "other uint64[]" },
89 { DMU_BSWAP_ZAP, TRUE, "other ZAP" },
90 { DMU_BSWAP_ZAP, TRUE, "persistent error log" },
91 { DMU_BSWAP_UINT8, TRUE, "SPA history" },
92 { DMU_BSWAP_UINT64, TRUE, "SPA history offsets" },
93 { DMU_BSWAP_ZAP, TRUE, "Pool properties" },
94 { DMU_BSWAP_ZAP, TRUE, "DSL permissions" },
95 { DMU_BSWAP_ACL, TRUE, "ZFS ACL" },
96 { DMU_BSWAP_UINT8, TRUE, "ZFS SYSACL" },
97 { DMU_BSWAP_UINT8, TRUE, "FUID table" },
98 { DMU_BSWAP_UINT64, TRUE, "FUID table size" },
99 { DMU_BSWAP_ZAP, TRUE, "DSL dataset next clones"},
100 { DMU_BSWAP_ZAP, TRUE, "scan work queue" },
101 { DMU_BSWAP_ZAP, TRUE, "ZFS user/group used" },
102 { DMU_BSWAP_ZAP, TRUE, "ZFS user/group quota" },
103 { DMU_BSWAP_ZAP, TRUE, "snapshot refcount tags"},
104 { DMU_BSWAP_ZAP, TRUE, "DDT ZAP algorithm" },
105 { DMU_BSWAP_ZAP, TRUE, "DDT statistics" },
106 { DMU_BSWAP_UINT8, TRUE, "System attributes" },
107 { DMU_BSWAP_ZAP, TRUE, "SA master node" },
108 { DMU_BSWAP_ZAP, TRUE, "SA attr registration" },
109 { DMU_BSWAP_ZAP, TRUE, "SA attr layouts" },
110 { DMU_BSWAP_ZAP, TRUE, "scan translations" },
111 { DMU_BSWAP_UINT8, FALSE, "deduplicated block" },
112 { DMU_BSWAP_ZAP, TRUE, "DSL deadlist map" },
113 { DMU_BSWAP_UINT64, TRUE, "DSL deadlist map hdr" },
114 { DMU_BSWAP_ZAP, TRUE, "DSL dir clones" },
115 { DMU_BSWAP_UINT64, TRUE, "bpobj subobj" }
116 };
117
118 const dmu_object_byteswap_info_t dmu_ot_byteswap[DMU_BSWAP_NUMFUNCS] = {
119 { byteswap_uint8_array, "uint8" },
120 { byteswap_uint16_array, "uint16" },
121 { byteswap_uint32_array, "uint32" },
122 { byteswap_uint64_array, "uint64" },
123 { zap_byteswap, "zap" },
124 { dnode_buf_byteswap, "dnode" },
125 { dmu_objset_byteswap, "objset" },
126 { zfs_znode_byteswap, "znode" },
127 { zfs_oldacl_byteswap, "oldacl" },
128 { zfs_acl_byteswap, "acl" }
129 };
130
131 int
132 dmu_buf_hold_noread_by_dnode(dnode_t *dn, uint64_t offset,
133 void *tag, dmu_buf_t **dbp)
134 {
135 uint64_t blkid;
136 dmu_buf_impl_t *db;
137
138 blkid = dbuf_whichblock(dn, 0, offset);
139 rw_enter(&dn->dn_struct_rwlock, RW_READER);
140 db = dbuf_hold(dn, blkid, tag);
141 rw_exit(&dn->dn_struct_rwlock);
142
143 if (db == NULL) {
144 *dbp = NULL;
145 return (SET_ERROR(EIO));
146 }
147
148 *dbp = &db->db;
149 return (0);
150 }
151 int
152 dmu_buf_hold_noread(objset_t *os, uint64_t object, uint64_t offset,
153 void *tag, dmu_buf_t **dbp)
154 {
155 dnode_t *dn;
156 uint64_t blkid;
157 dmu_buf_impl_t *db;
158 int err;
159
160 err = dnode_hold(os, object, FTAG, &dn);
161 if (err)
162 return (err);
163 blkid = dbuf_whichblock(dn, 0, offset);
164 rw_enter(&dn->dn_struct_rwlock, RW_READER);
165 db = dbuf_hold(dn, blkid, tag);
166 rw_exit(&dn->dn_struct_rwlock);
167 dnode_rele(dn, FTAG);
168
169 if (db == NULL) {
170 *dbp = NULL;
171 return (SET_ERROR(EIO));
172 }
173
174 *dbp = &db->db;
175 return (err);
176 }
177
178 int
179 dmu_buf_hold_by_dnode(dnode_t *dn, uint64_t offset,
180 void *tag, dmu_buf_t **dbp, int flags)
181 {
182 int err;
183 int db_flags = DB_RF_CANFAIL;
184
185 if (flags & DMU_READ_NO_PREFETCH)
186 db_flags |= DB_RF_NOPREFETCH;
187
188 err = dmu_buf_hold_noread_by_dnode(dn, offset, tag, dbp);
189 if (err == 0) {
190 dmu_buf_impl_t *db = (dmu_buf_impl_t *)(*dbp);
191 err = dbuf_read(db, NULL, db_flags);
192 if (err != 0) {
193 dbuf_rele(db, tag);
194 *dbp = NULL;
195 }
196 }
197
198 return (err);
199 }
200
201 int
202 dmu_buf_hold(objset_t *os, uint64_t object, uint64_t offset,
203 void *tag, dmu_buf_t **dbp, int flags)
204 {
205 int err;
206 int db_flags = DB_RF_CANFAIL;
207
208 if (flags & DMU_READ_NO_PREFETCH)
209 db_flags |= DB_RF_NOPREFETCH;
210
211 err = dmu_buf_hold_noread(os, object, offset, tag, dbp);
212 if (err == 0) {
213 dmu_buf_impl_t *db = (dmu_buf_impl_t *)(*dbp);
214 err = dbuf_read(db, NULL, db_flags);
215 if (err != 0) {
216 dbuf_rele(db, tag);
217 *dbp = NULL;
218 }
219 }
220
221 return (err);
222 }
223
224 int
225 dmu_bonus_max(void)
226 {
227 return (DN_OLD_MAX_BONUSLEN);
228 }
229
230 int
231 dmu_set_bonus(dmu_buf_t *db_fake, int newsize, dmu_tx_t *tx)
232 {
233 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
234 dnode_t *dn;
235 int error;
236
237 DB_DNODE_ENTER(db);
238 dn = DB_DNODE(db);
239
240 if (dn->dn_bonus != db) {
241 error = SET_ERROR(EINVAL);
242 } else if (newsize < 0 || newsize > db_fake->db_size) {
243 error = SET_ERROR(EINVAL);
244 } else {
245 dnode_setbonuslen(dn, newsize, tx);
246 error = 0;
247 }
248
249 DB_DNODE_EXIT(db);
250 return (error);
251 }
252
253 int
254 dmu_set_bonustype(dmu_buf_t *db_fake, dmu_object_type_t type, dmu_tx_t *tx)
255 {
256 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
257 dnode_t *dn;
258 int error;
259
260 DB_DNODE_ENTER(db);
261 dn = DB_DNODE(db);
262
263 if (!DMU_OT_IS_VALID(type)) {
264 error = SET_ERROR(EINVAL);
265 } else if (dn->dn_bonus != db) {
266 error = SET_ERROR(EINVAL);
267 } else {
268 dnode_setbonus_type(dn, type, tx);
269 error = 0;
270 }
271
272 DB_DNODE_EXIT(db);
273 return (error);
274 }
275
276 dmu_object_type_t
277 dmu_get_bonustype(dmu_buf_t *db_fake)
278 {
279 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
280 dnode_t *dn;
281 dmu_object_type_t type;
282
283 DB_DNODE_ENTER(db);
284 dn = DB_DNODE(db);
285 type = dn->dn_bonustype;
286 DB_DNODE_EXIT(db);
287
288 return (type);
289 }
290
291 int
292 dmu_rm_spill(objset_t *os, uint64_t object, dmu_tx_t *tx)
293 {
294 dnode_t *dn;
295 int error;
296
297 error = dnode_hold(os, object, FTAG, &dn);
298 dbuf_rm_spill(dn, tx);
299 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
300 dnode_rm_spill(dn, tx);
301 rw_exit(&dn->dn_struct_rwlock);
302 dnode_rele(dn, FTAG);
303 return (error);
304 }
305
306 /*
307 * returns ENOENT, EIO, or 0.
308 */
309 int
310 dmu_bonus_hold(objset_t *os, uint64_t object, void *tag, dmu_buf_t **dbp)
311 {
312 dnode_t *dn;
313 dmu_buf_impl_t *db;
314 int error;
315
316 error = dnode_hold(os, object, FTAG, &dn);
317 if (error)
318 return (error);
319
320 rw_enter(&dn->dn_struct_rwlock, RW_READER);
321 if (dn->dn_bonus == NULL) {
322 rw_exit(&dn->dn_struct_rwlock);
323 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
324 if (dn->dn_bonus == NULL)
325 dbuf_create_bonus(dn);
326 }
327 db = dn->dn_bonus;
328
329 /* as long as the bonus buf is held, the dnode will be held */
330 if (refcount_add(&db->db_holds, tag) == 1) {
331 VERIFY(dnode_add_ref(dn, db));
332 atomic_inc_32(&dn->dn_dbufs_count);
333 }
334
335 /*
336 * Wait to drop dn_struct_rwlock until after adding the bonus dbuf's
337 * hold and incrementing the dbuf count to ensure that dnode_move() sees
338 * a dnode hold for every dbuf.
339 */
340 rw_exit(&dn->dn_struct_rwlock);
341
342 dnode_rele(dn, FTAG);
343
344 VERIFY(0 == dbuf_read(db, NULL, DB_RF_MUST_SUCCEED | DB_RF_NOPREFETCH));
345
346 *dbp = &db->db;
347 return (0);
348 }
349
350 /*
351 * returns ENOENT, EIO, or 0.
352 *
353 * This interface will allocate a blank spill dbuf when a spill blk
354 * doesn't already exist on the dnode.
355 *
356 * if you only want to find an already existing spill db, then
357 * dmu_spill_hold_existing() should be used.
358 */
359 int
360 dmu_spill_hold_by_dnode(dnode_t *dn, uint32_t flags, void *tag, dmu_buf_t **dbp)
361 {
362 dmu_buf_impl_t *db = NULL;
363 int err;
364
365 if ((flags & DB_RF_HAVESTRUCT) == 0)
366 rw_enter(&dn->dn_struct_rwlock, RW_READER);
367
368 db = dbuf_hold(dn, DMU_SPILL_BLKID, tag);
369
370 if ((flags & DB_RF_HAVESTRUCT) == 0)
371 rw_exit(&dn->dn_struct_rwlock);
372
373 if (db == NULL) {
374 *dbp = NULL;
375 return (SET_ERROR(EIO));
376 }
377 err = dbuf_read(db, NULL, flags);
378 if (err == 0)
379 *dbp = &db->db;
380 else {
381 dbuf_rele(db, tag);
382 *dbp = NULL;
383 }
384 return (err);
385 }
386
387 int
388 dmu_spill_hold_existing(dmu_buf_t *bonus, void *tag, dmu_buf_t **dbp)
389 {
390 dmu_buf_impl_t *db = (dmu_buf_impl_t *)bonus;
391 dnode_t *dn;
392 int err;
393
394 DB_DNODE_ENTER(db);
395 dn = DB_DNODE(db);
396
397 if (spa_version(dn->dn_objset->os_spa) < SPA_VERSION_SA) {
398 err = SET_ERROR(EINVAL);
399 } else {
400 rw_enter(&dn->dn_struct_rwlock, RW_READER);
401
402 if (!dn->dn_have_spill) {
403 err = SET_ERROR(ENOENT);
404 } else {
405 err = dmu_spill_hold_by_dnode(dn,
406 DB_RF_HAVESTRUCT | DB_RF_CANFAIL, tag, dbp);
407 }
408
409 rw_exit(&dn->dn_struct_rwlock);
410 }
411
412 DB_DNODE_EXIT(db);
413 return (err);
414 }
415
416 int
417 dmu_spill_hold_by_bonus(dmu_buf_t *bonus, void *tag, dmu_buf_t **dbp)
418 {
419 dmu_buf_impl_t *db = (dmu_buf_impl_t *)bonus;
420 dnode_t *dn;
421 int err;
422
423 DB_DNODE_ENTER(db);
424 dn = DB_DNODE(db);
425 err = dmu_spill_hold_by_dnode(dn, DB_RF_CANFAIL, tag, dbp);
426 DB_DNODE_EXIT(db);
427
428 return (err);
429 }
430
431 /*
432 * Note: longer-term, we should modify all of the dmu_buf_*() interfaces
433 * to take a held dnode rather than <os, object> -- the lookup is wasteful,
434 * and can induce severe lock contention when writing to several files
435 * whose dnodes are in the same block.
436 */
437 static int
438 dmu_buf_hold_array_by_dnode(dnode_t *dn, uint64_t offset, uint64_t length,
439 boolean_t read, void *tag, int *numbufsp, dmu_buf_t ***dbpp, uint32_t flags)
440 {
441 dmu_buf_t **dbp;
442 uint64_t blkid, nblks, i;
443 uint32_t dbuf_flags;
444 int err;
445 zio_t *zio;
446
447 ASSERT(length <= DMU_MAX_ACCESS);
448
449 /*
450 * Note: We directly notify the prefetch code of this read, so that
451 * we can tell it about the multi-block read. dbuf_read() only knows
452 * about the one block it is accessing.
453 */
454 dbuf_flags = DB_RF_CANFAIL | DB_RF_NEVERWAIT | DB_RF_HAVESTRUCT |
455 DB_RF_NOPREFETCH;
456
457 rw_enter(&dn->dn_struct_rwlock, RW_READER);
458 if (dn->dn_datablkshift) {
459 int blkshift = dn->dn_datablkshift;
460 nblks = (P2ROUNDUP(offset + length, 1ULL << blkshift) -
461 P2ALIGN(offset, 1ULL << blkshift)) >> blkshift;
462 } else {
463 if (offset + length > dn->dn_datablksz) {
464 zfs_panic_recover("zfs: accessing past end of object "
465 "%llx/%llx (size=%u access=%llu+%llu)",
466 (longlong_t)dn->dn_objset->
467 os_dsl_dataset->ds_object,
468 (longlong_t)dn->dn_object, dn->dn_datablksz,
469 (longlong_t)offset, (longlong_t)length);
470 rw_exit(&dn->dn_struct_rwlock);
471 return (SET_ERROR(EIO));
472 }
473 nblks = 1;
474 }
475 dbp = kmem_zalloc(sizeof (dmu_buf_t *) * nblks, KM_SLEEP);
476
477 zio = zio_root(dn->dn_objset->os_spa, NULL, NULL, ZIO_FLAG_CANFAIL);
478 blkid = dbuf_whichblock(dn, 0, offset);
479 for (i = 0; i < nblks; i++) {
480 dmu_buf_impl_t *db = dbuf_hold(dn, blkid + i, tag);
481 if (db == NULL) {
482 rw_exit(&dn->dn_struct_rwlock);
483 dmu_buf_rele_array(dbp, nblks, tag);
484 zio_nowait(zio);
485 return (SET_ERROR(EIO));
486 }
487
488 /* initiate async i/o */
489 if (read)
490 (void) dbuf_read(db, zio, dbuf_flags);
491 dbp[i] = &db->db;
492 }
493
494 if ((flags & DMU_READ_NO_PREFETCH) == 0 &&
495 DNODE_META_IS_CACHEABLE(dn) && length <= zfetch_array_rd_sz) {
496 dmu_zfetch(&dn->dn_zfetch, blkid, nblks,
497 read && DNODE_IS_CACHEABLE(dn));
498 }
499 rw_exit(&dn->dn_struct_rwlock);
500
501 /* wait for async i/o */
502 err = zio_wait(zio);
503 if (err) {
504 dmu_buf_rele_array(dbp, nblks, tag);
505 return (err);
506 }
507
508 /* wait for other io to complete */
509 if (read) {
510 for (i = 0; i < nblks; i++) {
511 dmu_buf_impl_t *db = (dmu_buf_impl_t *)dbp[i];
512 mutex_enter(&db->db_mtx);
513 while (db->db_state == DB_READ ||
514 db->db_state == DB_FILL)
515 cv_wait(&db->db_changed, &db->db_mtx);
516 if (db->db_state == DB_UNCACHED)
517 err = SET_ERROR(EIO);
518 mutex_exit(&db->db_mtx);
519 if (err) {
520 dmu_buf_rele_array(dbp, nblks, tag);
521 return (err);
522 }
523 }
524 }
525
526 *numbufsp = nblks;
527 *dbpp = dbp;
528 return (0);
529 }
530
531 static int
532 dmu_buf_hold_array(objset_t *os, uint64_t object, uint64_t offset,
533 uint64_t length, int read, void *tag, int *numbufsp, dmu_buf_t ***dbpp)
534 {
535 dnode_t *dn;
536 int err;
537
538 err = dnode_hold(os, object, FTAG, &dn);
539 if (err)
540 return (err);
541
542 err = dmu_buf_hold_array_by_dnode(dn, offset, length, read, tag,
543 numbufsp, dbpp, DMU_READ_PREFETCH);
544
545 dnode_rele(dn, FTAG);
546
547 return (err);
548 }
549
550 int
551 dmu_buf_hold_array_by_bonus(dmu_buf_t *db_fake, uint64_t offset,
552 uint64_t length, boolean_t read, void *tag, int *numbufsp,
553 dmu_buf_t ***dbpp)
554 {
555 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
556 dnode_t *dn;
557 int err;
558
559 DB_DNODE_ENTER(db);
560 dn = DB_DNODE(db);
561 err = dmu_buf_hold_array_by_dnode(dn, offset, length, read, tag,
562 numbufsp, dbpp, DMU_READ_PREFETCH);
563 DB_DNODE_EXIT(db);
564
565 return (err);
566 }
567
568 void
569 dmu_buf_rele_array(dmu_buf_t **dbp_fake, int numbufs, void *tag)
570 {
571 int i;
572 dmu_buf_impl_t **dbp = (dmu_buf_impl_t **)dbp_fake;
573
574 if (numbufs == 0)
575 return;
576
577 for (i = 0; i < numbufs; i++) {
578 if (dbp[i])
579 dbuf_rele(dbp[i], tag);
580 }
581
582 kmem_free(dbp, sizeof (dmu_buf_t *) * numbufs);
583 }
584
585 /*
586 * Issue prefetch i/os for the given blocks. If level is greater than 0, the
587 * indirect blocks prefeteched will be those that point to the blocks containing
588 * the data starting at offset, and continuing to offset + len.
589 *
590 * Note that if the indirect blocks above the blocks being prefetched are not in
591 * cache, they will be asychronously read in.
592 */
593 void
594 dmu_prefetch(objset_t *os, uint64_t object, int64_t level, uint64_t offset,
595 uint64_t len, zio_priority_t pri)
596 {
597 dnode_t *dn;
598 uint64_t blkid;
599 int nblks, err;
600
601 if (len == 0) { /* they're interested in the bonus buffer */
602 dn = DMU_META_DNODE(os);
603
604 if (object == 0 || object >= DN_MAX_OBJECT)
605 return;
606
607 rw_enter(&dn->dn_struct_rwlock, RW_READER);
608 blkid = dbuf_whichblock(dn, level,
609 object * sizeof (dnode_phys_t));
610 dbuf_prefetch(dn, level, blkid, pri, 0);
611 rw_exit(&dn->dn_struct_rwlock);
612 return;
613 }
614
615 /*
616 * XXX - Note, if the dnode for the requested object is not
617 * already cached, we will do a *synchronous* read in the
618 * dnode_hold() call. The same is true for any indirects.
619 */
620 err = dnode_hold(os, object, FTAG, &dn);
621 if (err != 0)
622 return;
623
624 rw_enter(&dn->dn_struct_rwlock, RW_READER);
625 /*
626 * offset + len - 1 is the last byte we want to prefetch for, and offset
627 * is the first. Then dbuf_whichblk(dn, level, off + len - 1) is the
628 * last block we want to prefetch, and dbuf_whichblock(dn, level,
629 * offset) is the first. Then the number we need to prefetch is the
630 * last - first + 1.
631 */
632 if (level > 0 || dn->dn_datablkshift != 0) {
633 nblks = dbuf_whichblock(dn, level, offset + len - 1) -
634 dbuf_whichblock(dn, level, offset) + 1;
635 } else {
636 nblks = (offset < dn->dn_datablksz);
637 }
638
639 if (nblks != 0) {
640 int i;
641
642 blkid = dbuf_whichblock(dn, level, offset);
643 for (i = 0; i < nblks; i++)
644 dbuf_prefetch(dn, level, blkid + i, pri, 0);
645 }
646
647 rw_exit(&dn->dn_struct_rwlock);
648
649 dnode_rele(dn, FTAG);
650 }
651
652 /*
653 * Get the next "chunk" of file data to free. We traverse the file from
654 * the end so that the file gets shorter over time (if we crashes in the
655 * middle, this will leave us in a better state). We find allocated file
656 * data by simply searching the allocated level 1 indirects.
657 *
658 * On input, *start should be the first offset that does not need to be
659 * freed (e.g. "offset + length"). On return, *start will be the first
660 * offset that should be freed.
661 */
662 static int
663 get_next_chunk(dnode_t *dn, uint64_t *start, uint64_t minimum)
664 {
665 uint64_t maxblks = DMU_MAX_ACCESS >> (dn->dn_indblkshift + 1);
666 /* bytes of data covered by a level-1 indirect block */
667 uint64_t iblkrange =
668 dn->dn_datablksz * EPB(dn->dn_indblkshift, SPA_BLKPTRSHIFT);
669 uint64_t blks;
670
671 ASSERT3U(minimum, <=, *start);
672
673 if (*start - minimum <= iblkrange * maxblks) {
674 *start = minimum;
675 return (0);
676 }
677 ASSERT(ISP2(iblkrange));
678
679 for (blks = 0; *start > minimum && blks < maxblks; blks++) {
680 int err;
681
682 /*
683 * dnode_next_offset(BACKWARDS) will find an allocated L1
684 * indirect block at or before the input offset. We must
685 * decrement *start so that it is at the end of the region
686 * to search.
687 */
688 (*start)--;
689 err = dnode_next_offset(dn,
690 DNODE_FIND_BACKWARDS, start, 2, 1, 0);
691
692 /* if there are no indirect blocks before start, we are done */
693 if (err == ESRCH) {
694 *start = minimum;
695 break;
696 } else if (err != 0) {
697 return (err);
698 }
699
700 /* set start to the beginning of this L1 indirect */
701 *start = P2ALIGN(*start, iblkrange);
702 }
703 if (*start < minimum)
704 *start = minimum;
705 return (0);
706 }
707
708 /*
709 * If this objset is of type OST_ZFS return true if vfs's unmounted flag is set,
710 * otherwise return false.
711 * Used below in dmu_free_long_range_impl() to enable abort when unmounting
712 */
713 /*ARGSUSED*/
714 static boolean_t
715 dmu_objset_zfs_unmounting(objset_t *os)
716 {
717 #ifdef _KERNEL
718 if (dmu_objset_type(os) == DMU_OST_ZFS)
719 return (zfs_get_vfs_flag_unmounted(os));
720 #endif
721 return (B_FALSE);
722 }
723
724 static int
725 dmu_free_long_range_impl(objset_t *os, dnode_t *dn, uint64_t offset,
726 uint64_t length)
727 {
728 uint64_t object_size;
729 int err;
730
731 if (dn == NULL)
732 return (SET_ERROR(EINVAL));
733
734 object_size = (dn->dn_maxblkid + 1) * dn->dn_datablksz;
735 if (offset >= object_size)
736 return (0);
737
738 if (length == DMU_OBJECT_END || offset + length > object_size)
739 length = object_size - offset;
740
741 while (length != 0) {
742 uint64_t chunk_end, chunk_begin;
743 dmu_tx_t *tx;
744
745 if (dmu_objset_zfs_unmounting(dn->dn_objset))
746 return (SET_ERROR(EINTR));
747
748 chunk_end = chunk_begin = offset + length;
749
750 /* move chunk_begin backwards to the beginning of this chunk */
751 err = get_next_chunk(dn, &chunk_begin, offset);
752 if (err)
753 return (err);
754 ASSERT3U(chunk_begin, >=, offset);
755 ASSERT3U(chunk_begin, <=, chunk_end);
756
757 tx = dmu_tx_create(os);
758 dmu_tx_hold_free(tx, dn->dn_object,
759 chunk_begin, chunk_end - chunk_begin);
760
761 /*
762 * Mark this transaction as typically resulting in a net
763 * reduction in space used.
764 */
765 dmu_tx_mark_netfree(tx);
766 err = dmu_tx_assign(tx, TXG_WAIT);
767 if (err) {
768 dmu_tx_abort(tx);
769 return (err);
770 }
771 dnode_free_range(dn, chunk_begin, chunk_end - chunk_begin, tx);
772 dmu_tx_commit(tx);
773
774 length -= chunk_end - chunk_begin;
775 }
776 return (0);
777 }
778
779 int
780 dmu_free_long_range(objset_t *os, uint64_t object,
781 uint64_t offset, uint64_t length)
782 {
783 dnode_t *dn;
784 int err;
785
786 err = dnode_hold(os, object, FTAG, &dn);
787 if (err != 0)
788 return (err);
789 err = dmu_free_long_range_impl(os, dn, offset, length);
790
791 /*
792 * It is important to zero out the maxblkid when freeing the entire
793 * file, so that (a) subsequent calls to dmu_free_long_range_impl()
794 * will take the fast path, and (b) dnode_reallocate() can verify
795 * that the entire file has been freed.
796 */
797 if (err == 0 && offset == 0 && length == DMU_OBJECT_END)
798 dn->dn_maxblkid = 0;
799
800 dnode_rele(dn, FTAG);
801 return (err);
802 }
803
804 int
805 dmu_free_long_object(objset_t *os, uint64_t object)
806 {
807 dmu_tx_t *tx;
808 int err;
809
810 err = dmu_free_long_range(os, object, 0, DMU_OBJECT_END);
811 if (err != 0)
812 return (err);
813
814 tx = dmu_tx_create(os);
815 dmu_tx_hold_bonus(tx, object);
816 dmu_tx_hold_free(tx, object, 0, DMU_OBJECT_END);
817 dmu_tx_mark_netfree(tx);
818 err = dmu_tx_assign(tx, TXG_WAIT);
819 if (err == 0) {
820 err = dmu_object_free(os, object, tx);
821 dmu_tx_commit(tx);
822 } else {
823 dmu_tx_abort(tx);
824 }
825
826 return (err);
827 }
828
829 int
830 dmu_free_range(objset_t *os, uint64_t object, uint64_t offset,
831 uint64_t size, dmu_tx_t *tx)
832 {
833 dnode_t *dn;
834 int err = dnode_hold(os, object, FTAG, &dn);
835 if (err)
836 return (err);
837 ASSERT(offset < UINT64_MAX);
838 ASSERT(size == -1ULL || size <= UINT64_MAX - offset);
839 dnode_free_range(dn, offset, size, tx);
840 dnode_rele(dn, FTAG);
841 return (0);
842 }
843
844 static int
845 dmu_read_impl(dnode_t *dn, uint64_t offset, uint64_t size,
846 void *buf, uint32_t flags)
847 {
848 dmu_buf_t **dbp;
849 int numbufs, err = 0;
850
851 /*
852 * Deal with odd block sizes, where there can't be data past the first
853 * block. If we ever do the tail block optimization, we will need to
854 * handle that here as well.
855 */
856 if (dn->dn_maxblkid == 0) {
857 uint64_t newsz = offset > dn->dn_datablksz ? 0 :
858 MIN(size, dn->dn_datablksz - offset);
859 bzero((char *)buf + newsz, size - newsz);
860 size = newsz;
861 }
862
863 while (size > 0) {
864 uint64_t mylen = MIN(size, DMU_MAX_ACCESS / 2);
865 int i;
866
867 /*
868 * NB: we could do this block-at-a-time, but it's nice
869 * to be reading in parallel.
870 */
871 err = dmu_buf_hold_array_by_dnode(dn, offset, mylen,
872 TRUE, FTAG, &numbufs, &dbp, flags);
873 if (err)
874 break;
875
876 for (i = 0; i < numbufs; i++) {
877 uint64_t tocpy;
878 int64_t bufoff;
879 dmu_buf_t *db = dbp[i];
880
881 ASSERT(size > 0);
882
883 bufoff = offset - db->db_offset;
884 tocpy = MIN(db->db_size - bufoff, size);
885
886 (void) memcpy(buf, (char *)db->db_data + bufoff, tocpy);
887
888 offset += tocpy;
889 size -= tocpy;
890 buf = (char *)buf + tocpy;
891 }
892 dmu_buf_rele_array(dbp, numbufs, FTAG);
893 }
894 return (err);
895 }
896
897 int
898 dmu_read(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
899 void *buf, uint32_t flags)
900 {
901 dnode_t *dn;
902 int err;
903
904 err = dnode_hold(os, object, FTAG, &dn);
905 if (err != 0)
906 return (err);
907
908 err = dmu_read_impl(dn, offset, size, buf, flags);
909 dnode_rele(dn, FTAG);
910 return (err);
911 }
912
913 int
914 dmu_read_by_dnode(dnode_t *dn, uint64_t offset, uint64_t size, void *buf,
915 uint32_t flags)
916 {
917 return (dmu_read_impl(dn, offset, size, buf, flags));
918 }
919
920 static void
921 dmu_write_impl(dmu_buf_t **dbp, int numbufs, uint64_t offset, uint64_t size,
922 const void *buf, dmu_tx_t *tx)
923 {
924 int i;
925
926 for (i = 0; i < numbufs; i++) {
927 uint64_t tocpy;
928 int64_t bufoff;
929 dmu_buf_t *db = dbp[i];
930
931 ASSERT(size > 0);
932
933 bufoff = offset - db->db_offset;
934 tocpy = MIN(db->db_size - bufoff, size);
935
936 ASSERT(i == 0 || i == numbufs-1 || tocpy == db->db_size);
937
938 if (tocpy == db->db_size)
939 dmu_buf_will_fill(db, tx);
940 else
941 dmu_buf_will_dirty(db, tx);
942
943 (void) memcpy((char *)db->db_data + bufoff, buf, tocpy);
944
945 if (tocpy == db->db_size)
946 dmu_buf_fill_done(db, tx);
947
948 offset += tocpy;
949 size -= tocpy;
950 buf = (char *)buf + tocpy;
951 }
952 }
953
954 void
955 dmu_write(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
956 const void *buf, dmu_tx_t *tx)
957 {
958 dmu_buf_t **dbp;
959 int numbufs;
960
961 if (size == 0)
962 return;
963
964 VERIFY0(dmu_buf_hold_array(os, object, offset, size,
965 FALSE, FTAG, &numbufs, &dbp));
966 dmu_write_impl(dbp, numbufs, offset, size, buf, tx);
967 dmu_buf_rele_array(dbp, numbufs, FTAG);
968 }
969
970 void
971 dmu_write_by_dnode(dnode_t *dn, uint64_t offset, uint64_t size,
972 const void *buf, dmu_tx_t *tx)
973 {
974 dmu_buf_t **dbp;
975 int numbufs;
976
977 if (size == 0)
978 return;
979
980 VERIFY0(dmu_buf_hold_array_by_dnode(dn, offset, size,
981 FALSE, FTAG, &numbufs, &dbp, DMU_READ_PREFETCH));
982 dmu_write_impl(dbp, numbufs, offset, size, buf, tx);
983 dmu_buf_rele_array(dbp, numbufs, FTAG);
984 }
985
986 void
987 dmu_prealloc(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
988 dmu_tx_t *tx)
989 {
990 dmu_buf_t **dbp;
991 int numbufs, i;
992
993 if (size == 0)
994 return;
995
996 VERIFY(0 == dmu_buf_hold_array(os, object, offset, size,
997 FALSE, FTAG, &numbufs, &dbp));
998
999 for (i = 0; i < numbufs; i++) {
1000 dmu_buf_t *db = dbp[i];
1001
1002 dmu_buf_will_not_fill(db, tx);
1003 }
1004 dmu_buf_rele_array(dbp, numbufs, FTAG);
1005 }
1006
1007 void
1008 dmu_write_embedded(objset_t *os, uint64_t object, uint64_t offset,
1009 void *data, uint8_t etype, uint8_t comp, int uncompressed_size,
1010 int compressed_size, int byteorder, dmu_tx_t *tx)
1011 {
1012 dmu_buf_t *db;
1013
1014 ASSERT3U(etype, <, NUM_BP_EMBEDDED_TYPES);
1015 ASSERT3U(comp, <, ZIO_COMPRESS_FUNCTIONS);
1016 VERIFY0(dmu_buf_hold_noread(os, object, offset,
1017 FTAG, &db));
1018
1019 dmu_buf_write_embedded(db,
1020 data, (bp_embedded_type_t)etype, (enum zio_compress)comp,
1021 uncompressed_size, compressed_size, byteorder, tx);
1022
1023 dmu_buf_rele(db, FTAG);
1024 }
1025
1026 /*
1027 * DMU support for xuio
1028 */
1029 kstat_t *xuio_ksp = NULL;
1030
1031 typedef struct xuio_stats {
1032 /* loaned yet not returned arc_buf */
1033 kstat_named_t xuiostat_onloan_rbuf;
1034 kstat_named_t xuiostat_onloan_wbuf;
1035 /* whether a copy is made when loaning out a read buffer */
1036 kstat_named_t xuiostat_rbuf_copied;
1037 kstat_named_t xuiostat_rbuf_nocopy;
1038 /* whether a copy is made when assigning a write buffer */
1039 kstat_named_t xuiostat_wbuf_copied;
1040 kstat_named_t xuiostat_wbuf_nocopy;
1041 } xuio_stats_t;
1042
1043 static xuio_stats_t xuio_stats = {
1044 { "onloan_read_buf", KSTAT_DATA_UINT64 },
1045 { "onloan_write_buf", KSTAT_DATA_UINT64 },
1046 { "read_buf_copied", KSTAT_DATA_UINT64 },
1047 { "read_buf_nocopy", KSTAT_DATA_UINT64 },
1048 { "write_buf_copied", KSTAT_DATA_UINT64 },
1049 { "write_buf_nocopy", KSTAT_DATA_UINT64 }
1050 };
1051
1052 #define XUIOSTAT_INCR(stat, val) \
1053 atomic_add_64(&xuio_stats.stat.value.ui64, (val))
1054 #define XUIOSTAT_BUMP(stat) XUIOSTAT_INCR(stat, 1)
1055
1056 #ifdef HAVE_UIO_ZEROCOPY
1057 int
1058 dmu_xuio_init(xuio_t *xuio, int nblk)
1059 {
1060 dmu_xuio_t *priv;
1061 uio_t *uio = &xuio->xu_uio;
1062
1063 uio->uio_iovcnt = nblk;
1064 uio->uio_iov = kmem_zalloc(nblk * sizeof (iovec_t), KM_SLEEP);
1065
1066 priv = kmem_zalloc(sizeof (dmu_xuio_t), KM_SLEEP);
1067 priv->cnt = nblk;
1068 priv->bufs = kmem_zalloc(nblk * sizeof (arc_buf_t *), KM_SLEEP);
1069 priv->iovp = (iovec_t *)uio->uio_iov;
1070 XUIO_XUZC_PRIV(xuio) = priv;
1071
1072 if (XUIO_XUZC_RW(xuio) == UIO_READ)
1073 XUIOSTAT_INCR(xuiostat_onloan_rbuf, nblk);
1074 else
1075 XUIOSTAT_INCR(xuiostat_onloan_wbuf, nblk);
1076
1077 return (0);
1078 }
1079
1080 void
1081 dmu_xuio_fini(xuio_t *xuio)
1082 {
1083 dmu_xuio_t *priv = XUIO_XUZC_PRIV(xuio);
1084 int nblk = priv->cnt;
1085
1086 kmem_free(priv->iovp, nblk * sizeof (iovec_t));
1087 kmem_free(priv->bufs, nblk * sizeof (arc_buf_t *));
1088 kmem_free(priv, sizeof (dmu_xuio_t));
1089
1090 if (XUIO_XUZC_RW(xuio) == UIO_READ)
1091 XUIOSTAT_INCR(xuiostat_onloan_rbuf, -nblk);
1092 else
1093 XUIOSTAT_INCR(xuiostat_onloan_wbuf, -nblk);
1094 }
1095
1096 /*
1097 * Initialize iov[priv->next] and priv->bufs[priv->next] with { off, n, abuf }
1098 * and increase priv->next by 1.
1099 */
1100 int
1101 dmu_xuio_add(xuio_t *xuio, arc_buf_t *abuf, offset_t off, size_t n)
1102 {
1103 struct iovec *iov;
1104 uio_t *uio = &xuio->xu_uio;
1105 dmu_xuio_t *priv = XUIO_XUZC_PRIV(xuio);
1106 int i = priv->next++;
1107
1108 ASSERT(i < priv->cnt);
1109 ASSERT(off + n <= arc_buf_lsize(abuf));
1110 iov = (iovec_t *)uio->uio_iov + i;
1111 iov->iov_base = (char *)abuf->b_data + off;
1112 iov->iov_len = n;
1113 priv->bufs[i] = abuf;
1114 return (0);
1115 }
1116
1117 int
1118 dmu_xuio_cnt(xuio_t *xuio)
1119 {
1120 dmu_xuio_t *priv = XUIO_XUZC_PRIV(xuio);
1121 return (priv->cnt);
1122 }
1123
1124 arc_buf_t *
1125 dmu_xuio_arcbuf(xuio_t *xuio, int i)
1126 {
1127 dmu_xuio_t *priv = XUIO_XUZC_PRIV(xuio);
1128
1129 ASSERT(i < priv->cnt);
1130 return (priv->bufs[i]);
1131 }
1132
1133 void
1134 dmu_xuio_clear(xuio_t *xuio, int i)
1135 {
1136 dmu_xuio_t *priv = XUIO_XUZC_PRIV(xuio);
1137
1138 ASSERT(i < priv->cnt);
1139 priv->bufs[i] = NULL;
1140 }
1141 #endif /* HAVE_UIO_ZEROCOPY */
1142
1143 static void
1144 xuio_stat_init(void)
1145 {
1146 xuio_ksp = kstat_create("zfs", 0, "xuio_stats", "misc",
1147 KSTAT_TYPE_NAMED, sizeof (xuio_stats) / sizeof (kstat_named_t),
1148 KSTAT_FLAG_VIRTUAL);
1149 if (xuio_ksp != NULL) {
1150 xuio_ksp->ks_data = &xuio_stats;
1151 kstat_install(xuio_ksp);
1152 }
1153 }
1154
1155 static void
1156 xuio_stat_fini(void)
1157 {
1158 if (xuio_ksp != NULL) {
1159 kstat_delete(xuio_ksp);
1160 xuio_ksp = NULL;
1161 }
1162 }
1163
1164 void
1165 xuio_stat_wbuf_copied(void)
1166 {
1167 XUIOSTAT_BUMP(xuiostat_wbuf_copied);
1168 }
1169
1170 void
1171 xuio_stat_wbuf_nocopy(void)
1172 {
1173 XUIOSTAT_BUMP(xuiostat_wbuf_nocopy);
1174 }
1175
1176 #ifdef _KERNEL
1177 static int
1178 dmu_read_uio_dnode(dnode_t *dn, uio_t *uio, uint64_t size)
1179 {
1180 dmu_buf_t **dbp;
1181 int numbufs, i, err;
1182 #ifdef HAVE_UIO_ZEROCOPY
1183 xuio_t *xuio = NULL;
1184 #endif
1185
1186 /*
1187 * NB: we could do this block-at-a-time, but it's nice
1188 * to be reading in parallel.
1189 */
1190 err = dmu_buf_hold_array_by_dnode(dn, uio->uio_loffset, size,
1191 TRUE, FTAG, &numbufs, &dbp, 0);
1192 if (err)
1193 return (err);
1194
1195 for (i = 0; i < numbufs; i++) {
1196 uint64_t tocpy;
1197 int64_t bufoff;
1198 dmu_buf_t *db = dbp[i];
1199
1200 ASSERT(size > 0);
1201
1202 bufoff = uio->uio_loffset - db->db_offset;
1203 tocpy = MIN(db->db_size - bufoff, size);
1204
1205 #ifdef HAVE_UIO_ZEROCOPY
1206 if (xuio) {
1207 dmu_buf_impl_t *dbi = (dmu_buf_impl_t *)db;
1208 arc_buf_t *dbuf_abuf = dbi->db_buf;
1209 arc_buf_t *abuf = dbuf_loan_arcbuf(dbi);
1210 err = dmu_xuio_add(xuio, abuf, bufoff, tocpy);
1211 if (!err) {
1212 uio->uio_resid -= tocpy;
1213 uio->uio_loffset += tocpy;
1214 }
1215
1216 if (abuf == dbuf_abuf)
1217 XUIOSTAT_BUMP(xuiostat_rbuf_nocopy);
1218 else
1219 XUIOSTAT_BUMP(xuiostat_rbuf_copied);
1220 } else
1221 #endif
1222 err = uiomove((char *)db->db_data + bufoff, tocpy,
1223 UIO_READ, uio);
1224 if (err)
1225 break;
1226
1227 size -= tocpy;
1228 }
1229 dmu_buf_rele_array(dbp, numbufs, FTAG);
1230
1231 return (err);
1232 }
1233
1234 /*
1235 * Read 'size' bytes into the uio buffer.
1236 * From object zdb->db_object.
1237 * Starting at offset uio->uio_loffset.
1238 *
1239 * If the caller already has a dbuf in the target object
1240 * (e.g. its bonus buffer), this routine is faster than dmu_read_uio(),
1241 * because we don't have to find the dnode_t for the object.
1242 */
1243 int
1244 dmu_read_uio_dbuf(dmu_buf_t *zdb, uio_t *uio, uint64_t size)
1245 {
1246 dmu_buf_impl_t *db = (dmu_buf_impl_t *)zdb;
1247 dnode_t *dn;
1248 int err;
1249
1250 if (size == 0)
1251 return (0);
1252
1253 DB_DNODE_ENTER(db);
1254 dn = DB_DNODE(db);
1255 err = dmu_read_uio_dnode(dn, uio, size);
1256 DB_DNODE_EXIT(db);
1257
1258 return (err);
1259 }
1260
1261 /*
1262 * Read 'size' bytes into the uio buffer.
1263 * From the specified object
1264 * Starting at offset uio->uio_loffset.
1265 */
1266 int
1267 dmu_read_uio(objset_t *os, uint64_t object, uio_t *uio, uint64_t size)
1268 {
1269 dnode_t *dn;
1270 int err;
1271
1272 if (size == 0)
1273 return (0);
1274
1275 err = dnode_hold(os, object, FTAG, &dn);
1276 if (err)
1277 return (err);
1278
1279 err = dmu_read_uio_dnode(dn, uio, size);
1280
1281 dnode_rele(dn, FTAG);
1282
1283 return (err);
1284 }
1285
1286 static int
1287 dmu_write_uio_dnode(dnode_t *dn, uio_t *uio, uint64_t size, dmu_tx_t *tx)
1288 {
1289 dmu_buf_t **dbp;
1290 int numbufs;
1291 int err = 0;
1292 int i;
1293
1294 err = dmu_buf_hold_array_by_dnode(dn, uio->uio_loffset, size,
1295 FALSE, FTAG, &numbufs, &dbp, DMU_READ_PREFETCH);
1296 if (err)
1297 return (err);
1298
1299 for (i = 0; i < numbufs; i++) {
1300 uint64_t tocpy;
1301 int64_t bufoff;
1302 dmu_buf_t *db = dbp[i];
1303
1304 ASSERT(size > 0);
1305
1306 bufoff = uio->uio_loffset - db->db_offset;
1307 tocpy = MIN(db->db_size - bufoff, size);
1308
1309 ASSERT(i == 0 || i == numbufs-1 || tocpy == db->db_size);
1310
1311 if (tocpy == db->db_size)
1312 dmu_buf_will_fill(db, tx);
1313 else
1314 dmu_buf_will_dirty(db, tx);
1315
1316 /*
1317 * XXX uiomove could block forever (eg.nfs-backed
1318 * pages). There needs to be a uiolockdown() function
1319 * to lock the pages in memory, so that uiomove won't
1320 * block.
1321 */
1322 err = uiomove((char *)db->db_data + bufoff, tocpy,
1323 UIO_WRITE, uio);
1324
1325 if (tocpy == db->db_size)
1326 dmu_buf_fill_done(db, tx);
1327
1328 if (err)
1329 break;
1330
1331 size -= tocpy;
1332 }
1333
1334 dmu_buf_rele_array(dbp, numbufs, FTAG);
1335 return (err);
1336 }
1337
1338 /*
1339 * Write 'size' bytes from the uio buffer.
1340 * To object zdb->db_object.
1341 * Starting at offset uio->uio_loffset.
1342 *
1343 * If the caller already has a dbuf in the target object
1344 * (e.g. its bonus buffer), this routine is faster than dmu_write_uio(),
1345 * because we don't have to find the dnode_t for the object.
1346 */
1347 int
1348 dmu_write_uio_dbuf(dmu_buf_t *zdb, uio_t *uio, uint64_t size,
1349 dmu_tx_t *tx)
1350 {
1351 dmu_buf_impl_t *db = (dmu_buf_impl_t *)zdb;
1352 dnode_t *dn;
1353 int err;
1354
1355 if (size == 0)
1356 return (0);
1357
1358 DB_DNODE_ENTER(db);
1359 dn = DB_DNODE(db);
1360 err = dmu_write_uio_dnode(dn, uio, size, tx);
1361 DB_DNODE_EXIT(db);
1362
1363 return (err);
1364 }
1365
1366 /*
1367 * Write 'size' bytes from the uio buffer.
1368 * To the specified object.
1369 * Starting at offset uio->uio_loffset.
1370 */
1371 int
1372 dmu_write_uio(objset_t *os, uint64_t object, uio_t *uio, uint64_t size,
1373 dmu_tx_t *tx)
1374 {
1375 dnode_t *dn;
1376 int err;
1377
1378 if (size == 0)
1379 return (0);
1380
1381 err = dnode_hold(os, object, FTAG, &dn);
1382 if (err)
1383 return (err);
1384
1385 err = dmu_write_uio_dnode(dn, uio, size, tx);
1386
1387 dnode_rele(dn, FTAG);
1388
1389 return (err);
1390 }
1391 #endif /* _KERNEL */
1392
1393 /*
1394 * Allocate a loaned anonymous arc buffer.
1395 */
1396 arc_buf_t *
1397 dmu_request_arcbuf(dmu_buf_t *handle, int size)
1398 {
1399 dmu_buf_impl_t *db = (dmu_buf_impl_t *)handle;
1400
1401 return (arc_loan_buf(db->db_objset->os_spa, B_FALSE, size));
1402 }
1403
1404 /*
1405 * Free a loaned arc buffer.
1406 */
1407 void
1408 dmu_return_arcbuf(arc_buf_t *buf)
1409 {
1410 arc_return_buf(buf, FTAG);
1411 arc_buf_destroy(buf, FTAG);
1412 }
1413
1414 /*
1415 * When possible directly assign passed loaned arc buffer to a dbuf.
1416 * If this is not possible copy the contents of passed arc buf via
1417 * dmu_write().
1418 */
1419 void
1420 dmu_assign_arcbuf(dmu_buf_t *handle, uint64_t offset, arc_buf_t *buf,
1421 dmu_tx_t *tx)
1422 {
1423 dmu_buf_impl_t *dbuf = (dmu_buf_impl_t *)handle;
1424 dnode_t *dn;
1425 dmu_buf_impl_t *db;
1426 uint32_t blksz = (uint32_t)arc_buf_lsize(buf);
1427 uint64_t blkid;
1428
1429 DB_DNODE_ENTER(dbuf);
1430 dn = DB_DNODE(dbuf);
1431 rw_enter(&dn->dn_struct_rwlock, RW_READER);
1432 blkid = dbuf_whichblock(dn, 0, offset);
1433 VERIFY((db = dbuf_hold(dn, blkid, FTAG)) != NULL);
1434 rw_exit(&dn->dn_struct_rwlock);
1435 DB_DNODE_EXIT(dbuf);
1436
1437 /*
1438 * We can only assign if the offset is aligned, the arc buf is the
1439 * same size as the dbuf, and the dbuf is not metadata.
1440 */
1441 if (offset == db->db.db_offset && blksz == db->db.db_size) {
1442 dbuf_assign_arcbuf(db, buf, tx);
1443 dbuf_rele(db, FTAG);
1444 } else {
1445 objset_t *os;
1446 uint64_t object;
1447
1448 /* compressed bufs must always be assignable to their dbuf */
1449 ASSERT3U(arc_get_compression(buf), ==, ZIO_COMPRESS_OFF);
1450 ASSERT(!(buf->b_flags & ARC_BUF_FLAG_COMPRESSED));
1451
1452 DB_DNODE_ENTER(dbuf);
1453 dn = DB_DNODE(dbuf);
1454 os = dn->dn_objset;
1455 object = dn->dn_object;
1456 DB_DNODE_EXIT(dbuf);
1457
1458 dbuf_rele(db, FTAG);
1459 dmu_write(os, object, offset, blksz, buf->b_data, tx);
1460 dmu_return_arcbuf(buf);
1461 XUIOSTAT_BUMP(xuiostat_wbuf_copied);
1462 }
1463 }
1464
1465 typedef struct {
1466 dbuf_dirty_record_t *dsa_dr;
1467 dmu_sync_cb_t *dsa_done;
1468 zgd_t *dsa_zgd;
1469 dmu_tx_t *dsa_tx;
1470 } dmu_sync_arg_t;
1471
1472 /* ARGSUSED */
1473 static void
1474 dmu_sync_ready(zio_t *zio, arc_buf_t *buf, void *varg)
1475 {
1476 dmu_sync_arg_t *dsa = varg;
1477 dmu_buf_t *db = dsa->dsa_zgd->zgd_db;
1478 blkptr_t *bp = zio->io_bp;
1479
1480 if (zio->io_error == 0) {
1481 if (BP_IS_HOLE(bp)) {
1482 /*
1483 * A block of zeros may compress to a hole, but the
1484 * block size still needs to be known for replay.
1485 */
1486 BP_SET_LSIZE(bp, db->db_size);
1487 } else if (!BP_IS_EMBEDDED(bp)) {
1488 ASSERT(BP_GET_LEVEL(bp) == 0);
1489 bp->blk_fill = 1;
1490 }
1491 }
1492 }
1493
1494 static void
1495 dmu_sync_late_arrival_ready(zio_t *zio)
1496 {
1497 dmu_sync_ready(zio, NULL, zio->io_private);
1498 }
1499
1500 /* ARGSUSED */
1501 static void
1502 dmu_sync_done(zio_t *zio, arc_buf_t *buf, void *varg)
1503 {
1504 dmu_sync_arg_t *dsa = varg;
1505 dbuf_dirty_record_t *dr = dsa->dsa_dr;
1506 dmu_buf_impl_t *db = dr->dr_dbuf;
1507
1508 mutex_enter(&db->db_mtx);
1509 ASSERT(dr->dt.dl.dr_override_state == DR_IN_DMU_SYNC);
1510 if (zio->io_error == 0) {
1511 dr->dt.dl.dr_nopwrite = !!(zio->io_flags & ZIO_FLAG_NOPWRITE);
1512 if (dr->dt.dl.dr_nopwrite) {
1513 ASSERTV(blkptr_t *bp = zio->io_bp);
1514 ASSERTV(blkptr_t *bp_orig = &zio->io_bp_orig);
1515 ASSERTV(uint8_t chksum = BP_GET_CHECKSUM(bp_orig));
1516
1517 ASSERT(BP_EQUAL(bp, bp_orig));
1518 ASSERT(zio->io_prop.zp_compress != ZIO_COMPRESS_OFF);
1519 ASSERT(zio_checksum_table[chksum].ci_flags &
1520 ZCHECKSUM_FLAG_NOPWRITE);
1521 }
1522 dr->dt.dl.dr_overridden_by = *zio->io_bp;
1523 dr->dt.dl.dr_override_state = DR_OVERRIDDEN;
1524 dr->dt.dl.dr_copies = zio->io_prop.zp_copies;
1525
1526 /*
1527 * Old style holes are filled with all zeros, whereas
1528 * new-style holes maintain their lsize, type, level,
1529 * and birth time (see zio_write_compress). While we
1530 * need to reset the BP_SET_LSIZE() call that happened
1531 * in dmu_sync_ready for old style holes, we do *not*
1532 * want to wipe out the information contained in new
1533 * style holes. Thus, only zero out the block pointer if
1534 * it's an old style hole.
1535 */
1536 if (BP_IS_HOLE(&dr->dt.dl.dr_overridden_by) &&
1537 dr->dt.dl.dr_overridden_by.blk_birth == 0)
1538 BP_ZERO(&dr->dt.dl.dr_overridden_by);
1539 } else {
1540 dr->dt.dl.dr_override_state = DR_NOT_OVERRIDDEN;
1541 }
1542 cv_broadcast(&db->db_changed);
1543 mutex_exit(&db->db_mtx);
1544
1545 dsa->dsa_done(dsa->dsa_zgd, zio->io_error);
1546
1547 kmem_free(dsa, sizeof (*dsa));
1548 }
1549
1550 static void
1551 dmu_sync_late_arrival_done(zio_t *zio)
1552 {
1553 blkptr_t *bp = zio->io_bp;
1554 dmu_sync_arg_t *dsa = zio->io_private;
1555 ASSERTV(blkptr_t *bp_orig = &zio->io_bp_orig);
1556
1557 if (zio->io_error == 0 && !BP_IS_HOLE(bp)) {
1558 /*
1559 * If we didn't allocate a new block (i.e. ZIO_FLAG_NOPWRITE)
1560 * then there is nothing to do here. Otherwise, free the
1561 * newly allocated block in this txg.
1562 */
1563 if (zio->io_flags & ZIO_FLAG_NOPWRITE) {
1564 ASSERT(BP_EQUAL(bp, bp_orig));
1565 } else {
1566 ASSERT(BP_IS_HOLE(bp_orig) || !BP_EQUAL(bp, bp_orig));
1567 ASSERT(zio->io_bp->blk_birth == zio->io_txg);
1568 ASSERT(zio->io_txg > spa_syncing_txg(zio->io_spa));
1569 zio_free(zio->io_spa, zio->io_txg, zio->io_bp);
1570 }
1571 }
1572
1573 dmu_tx_commit(dsa->dsa_tx);
1574
1575 dsa->dsa_done(dsa->dsa_zgd, zio->io_error);
1576
1577 abd_put(zio->io_abd);
1578 kmem_free(dsa, sizeof (*dsa));
1579 }
1580
1581 static int
1582 dmu_sync_late_arrival(zio_t *pio, objset_t *os, dmu_sync_cb_t *done, zgd_t *zgd,
1583 zio_prop_t *zp, zbookmark_phys_t *zb)
1584 {
1585 dmu_sync_arg_t *dsa;
1586 dmu_tx_t *tx;
1587
1588 tx = dmu_tx_create(os);
1589 dmu_tx_hold_space(tx, zgd->zgd_db->db_size);
1590 if (dmu_tx_assign(tx, TXG_WAIT) != 0) {
1591 dmu_tx_abort(tx);
1592 /* Make zl_get_data do txg_waited_synced() */
1593 return (SET_ERROR(EIO));
1594 }
1595
1596 dsa = kmem_alloc(sizeof (dmu_sync_arg_t), KM_SLEEP);
1597 dsa->dsa_dr = NULL;
1598 dsa->dsa_done = done;
1599 dsa->dsa_zgd = zgd;
1600 dsa->dsa_tx = tx;
1601
1602 zio_nowait(zio_write(pio, os->os_spa, dmu_tx_get_txg(tx), zgd->zgd_bp,
1603 abd_get_from_buf(zgd->zgd_db->db_data, zgd->zgd_db->db_size),
1604 zgd->zgd_db->db_size, zgd->zgd_db->db_size, zp,
1605 dmu_sync_late_arrival_ready, NULL, NULL, dmu_sync_late_arrival_done,
1606 dsa, ZIO_PRIORITY_SYNC_WRITE, ZIO_FLAG_CANFAIL, zb));
1607
1608 return (0);
1609 }
1610
1611 /*
1612 * Intent log support: sync the block associated with db to disk.
1613 * N.B. and XXX: the caller is responsible for making sure that the
1614 * data isn't changing while dmu_sync() is writing it.
1615 *
1616 * Return values:
1617 *
1618 * EEXIST: this txg has already been synced, so there's nothing to do.
1619 * The caller should not log the write.
1620 *
1621 * ENOENT: the block was dbuf_free_range()'d, so there's nothing to do.
1622 * The caller should not log the write.
1623 *
1624 * EALREADY: this block is already in the process of being synced.
1625 * The caller should track its progress (somehow).
1626 *
1627 * EIO: could not do the I/O.
1628 * The caller should do a txg_wait_synced().
1629 *
1630 * 0: the I/O has been initiated.
1631 * The caller should log this blkptr in the done callback.
1632 * It is possible that the I/O will fail, in which case
1633 * the error will be reported to the done callback and
1634 * propagated to pio from zio_done().
1635 */
1636 int
1637 dmu_sync(zio_t *pio, uint64_t txg, dmu_sync_cb_t *done, zgd_t *zgd)
1638 {
1639 blkptr_t *bp = zgd->zgd_bp;
1640 dmu_buf_impl_t *db = (dmu_buf_impl_t *)zgd->zgd_db;
1641 objset_t *os = db->db_objset;
1642 dsl_dataset_t *ds = os->os_dsl_dataset;
1643 dbuf_dirty_record_t *dr;
1644 dmu_sync_arg_t *dsa;
1645 zbookmark_phys_t zb;
1646 zio_prop_t zp;
1647 dnode_t *dn;
1648
1649 ASSERT(pio != NULL);
1650 ASSERT(txg != 0);
1651
1652 SET_BOOKMARK(&zb, ds->ds_object,
1653 db->db.db_object, db->db_level, db->db_blkid);
1654
1655 DB_DNODE_ENTER(db);
1656 dn = DB_DNODE(db);
1657 dmu_write_policy(os, dn, db->db_level, WP_DMU_SYNC,
1658 ZIO_COMPRESS_INHERIT, &zp);
1659 DB_DNODE_EXIT(db);
1660
1661 /*
1662 * If we're frozen (running ziltest), we always need to generate a bp.
1663 */
1664 if (txg > spa_freeze_txg(os->os_spa))
1665 return (dmu_sync_late_arrival(pio, os, done, zgd, &zp, &zb));
1666
1667 /*
1668 * Grabbing db_mtx now provides a barrier between dbuf_sync_leaf()
1669 * and us. If we determine that this txg is not yet syncing,
1670 * but it begins to sync a moment later, that's OK because the
1671 * sync thread will block in dbuf_sync_leaf() until we drop db_mtx.
1672 */
1673 mutex_enter(&db->db_mtx);
1674
1675 if (txg <= spa_last_synced_txg(os->os_spa)) {
1676 /*
1677 * This txg has already synced. There's nothing to do.
1678 */
1679 mutex_exit(&db->db_mtx);
1680 return (SET_ERROR(EEXIST));
1681 }
1682
1683 if (txg <= spa_syncing_txg(os->os_spa)) {
1684 /*
1685 * This txg is currently syncing, so we can't mess with
1686 * the dirty record anymore; just write a new log block.
1687 */
1688 mutex_exit(&db->db_mtx);
1689 return (dmu_sync_late_arrival(pio, os, done, zgd, &zp, &zb));
1690 }
1691
1692 dr = db->db_last_dirty;
1693 while (dr && dr->dr_txg != txg)
1694 dr = dr->dr_next;
1695
1696 if (dr == NULL) {
1697 /*
1698 * There's no dr for this dbuf, so it must have been freed.
1699 * There's no need to log writes to freed blocks, so we're done.
1700 */
1701 mutex_exit(&db->db_mtx);
1702 return (SET_ERROR(ENOENT));
1703 }
1704
1705 ASSERT(dr->dr_next == NULL || dr->dr_next->dr_txg < txg);
1706
1707 /*
1708 * Assume the on-disk data is X, the current syncing data (in
1709 * txg - 1) is Y, and the current in-memory data is Z (currently
1710 * in dmu_sync).
1711 *
1712 * We usually want to perform a nopwrite if X and Z are the
1713 * same. However, if Y is different (i.e. the BP is going to
1714 * change before this write takes effect), then a nopwrite will
1715 * be incorrect - we would override with X, which could have
1716 * been freed when Y was written.
1717 *
1718 * (Note that this is not a concern when we are nop-writing from
1719 * syncing context, because X and Y must be identical, because
1720 * all previous txgs have been synced.)
1721 *
1722 * Therefore, we disable nopwrite if the current BP could change
1723 * before this TXG. There are two ways it could change: by
1724 * being dirty (dr_next is non-NULL), or by being freed
1725 * (dnode_block_freed()). This behavior is verified by
1726 * zio_done(), which VERIFYs that the override BP is identical
1727 * to the on-disk BP.
1728 */
1729 DB_DNODE_ENTER(db);
1730 dn = DB_DNODE(db);
1731 if (dr->dr_next != NULL || dnode_block_freed(dn, db->db_blkid))
1732 zp.zp_nopwrite = B_FALSE;
1733 DB_DNODE_EXIT(db);
1734
1735 ASSERT(dr->dr_txg == txg);
1736 if (dr->dt.dl.dr_override_state == DR_IN_DMU_SYNC ||
1737 dr->dt.dl.dr_override_state == DR_OVERRIDDEN) {
1738 /*
1739 * We have already issued a sync write for this buffer,
1740 * or this buffer has already been synced. It could not
1741 * have been dirtied since, or we would have cleared the state.
1742 */
1743 mutex_exit(&db->db_mtx);
1744 return (SET_ERROR(EALREADY));
1745 }
1746
1747 ASSERT(dr->dt.dl.dr_override_state == DR_NOT_OVERRIDDEN);
1748 dr->dt.dl.dr_override_state = DR_IN_DMU_SYNC;
1749 mutex_exit(&db->db_mtx);
1750
1751 dsa = kmem_alloc(sizeof (dmu_sync_arg_t), KM_SLEEP);
1752 dsa->dsa_dr = dr;
1753 dsa->dsa_done = done;
1754 dsa->dsa_zgd = zgd;
1755 dsa->dsa_tx = NULL;
1756
1757 zio_nowait(arc_write(pio, os->os_spa, txg,
1758 bp, dr->dt.dl.dr_data, DBUF_IS_L2CACHEABLE(db),
1759 &zp, dmu_sync_ready, NULL, NULL, dmu_sync_done, dsa,
1760 ZIO_PRIORITY_SYNC_WRITE, ZIO_FLAG_CANFAIL, &zb));
1761
1762 return (0);
1763 }
1764
1765 int
1766 dmu_object_set_blocksize(objset_t *os, uint64_t object, uint64_t size, int ibs,
1767 dmu_tx_t *tx)
1768 {
1769 dnode_t *dn;
1770 int err;
1771
1772 err = dnode_hold(os, object, FTAG, &dn);
1773 if (err)
1774 return (err);
1775 err = dnode_set_blksz(dn, size, ibs, tx);
1776 dnode_rele(dn, FTAG);
1777 return (err);
1778 }
1779
1780 void
1781 dmu_object_set_checksum(objset_t *os, uint64_t object, uint8_t checksum,
1782 dmu_tx_t *tx)
1783 {
1784 dnode_t *dn;
1785
1786 /*
1787 * Send streams include each object's checksum function. This
1788 * check ensures that the receiving system can understand the
1789 * checksum function transmitted.
1790 */
1791 ASSERT3U(checksum, <, ZIO_CHECKSUM_LEGACY_FUNCTIONS);
1792
1793 VERIFY0(dnode_hold(os, object, FTAG, &dn));
1794 ASSERT3U(checksum, <, ZIO_CHECKSUM_FUNCTIONS);
1795 dn->dn_checksum = checksum;
1796 dnode_setdirty(dn, tx);
1797 dnode_rele(dn, FTAG);
1798 }
1799
1800 void
1801 dmu_object_set_compress(objset_t *os, uint64_t object, uint8_t compress,
1802 dmu_tx_t *tx)
1803 {
1804 dnode_t *dn;
1805
1806 /*
1807 * Send streams include each object's compression function. This
1808 * check ensures that the receiving system can understand the
1809 * compression function transmitted.
1810 */
1811 ASSERT3U(compress, <, ZIO_COMPRESS_LEGACY_FUNCTIONS);
1812
1813 VERIFY0(dnode_hold(os, object, FTAG, &dn));
1814 dn->dn_compress = compress;
1815 dnode_setdirty(dn, tx);
1816 dnode_rele(dn, FTAG);
1817 }
1818
1819 int zfs_mdcomp_disable = 0;
1820
1821 /*
1822 * When the "redundant_metadata" property is set to "most", only indirect
1823 * blocks of this level and higher will have an additional ditto block.
1824 */
1825 int zfs_redundant_metadata_most_ditto_level = 2;
1826
1827 void
1828 dmu_write_policy(objset_t *os, dnode_t *dn, int level, int wp,
1829 enum zio_compress override_compress, zio_prop_t *zp)
1830 {
1831 dmu_object_type_t type = dn ? dn->dn_type : DMU_OT_OBJSET;
1832 boolean_t ismd = (level > 0 || DMU_OT_IS_METADATA(type) ||
1833 (wp & WP_SPILL));
1834 enum zio_checksum checksum = os->os_checksum;
1835 enum zio_compress compress = os->os_compress;
1836 enum zio_checksum dedup_checksum = os->os_dedup_checksum;
1837 boolean_t dedup = B_FALSE;
1838 boolean_t nopwrite = B_FALSE;
1839 boolean_t dedup_verify = os->os_dedup_verify;
1840 int copies = os->os_copies;
1841
1842 /*
1843 * We maintain different write policies for each of the following
1844 * types of data:
1845 * 1. metadata
1846 * 2. preallocated blocks (i.e. level-0 blocks of a dump device)
1847 * 3. all other level 0 blocks
1848 */
1849 if (ismd) {
1850 if (zfs_mdcomp_disable) {
1851 compress = ZIO_COMPRESS_EMPTY;
1852 } else {
1853 /*
1854 * XXX -- we should design a compression algorithm
1855 * that specializes in arrays of bps.
1856 */
1857 compress = zio_compress_select(os->os_spa,
1858 ZIO_COMPRESS_ON, ZIO_COMPRESS_ON);
1859 }
1860
1861 /*
1862 * Metadata always gets checksummed. If the data
1863 * checksum is multi-bit correctable, and it's not a
1864 * ZBT-style checksum, then it's suitable for metadata
1865 * as well. Otherwise, the metadata checksum defaults
1866 * to fletcher4.
1867 */
1868 if (!(zio_checksum_table[checksum].ci_flags &
1869 ZCHECKSUM_FLAG_METADATA) ||
1870 (zio_checksum_table[checksum].ci_flags &
1871 ZCHECKSUM_FLAG_EMBEDDED))
1872 checksum = ZIO_CHECKSUM_FLETCHER_4;
1873
1874 if (os->os_redundant_metadata == ZFS_REDUNDANT_METADATA_ALL ||
1875 (os->os_redundant_metadata ==
1876 ZFS_REDUNDANT_METADATA_MOST &&
1877 (level >= zfs_redundant_metadata_most_ditto_level ||
1878 DMU_OT_IS_METADATA(type) || (wp & WP_SPILL))))
1879 copies++;
1880 } else if (wp & WP_NOFILL) {
1881 ASSERT(level == 0);
1882
1883 /*
1884 * If we're writing preallocated blocks, we aren't actually
1885 * writing them so don't set any policy properties. These
1886 * blocks are currently only used by an external subsystem
1887 * outside of zfs (i.e. dump) and not written by the zio
1888 * pipeline.
1889 */
1890 compress = ZIO_COMPRESS_OFF;
1891 checksum = ZIO_CHECKSUM_OFF;
1892 } else {
1893 compress = zio_compress_select(os->os_spa, dn->dn_compress,
1894 compress);
1895
1896 checksum = (dedup_checksum == ZIO_CHECKSUM_OFF) ?
1897 zio_checksum_select(dn->dn_checksum, checksum) :
1898 dedup_checksum;
1899
1900 /*
1901 * Determine dedup setting. If we are in dmu_sync(),
1902 * we won't actually dedup now because that's all
1903 * done in syncing context; but we do want to use the
1904 * dedup checkum. If the checksum is not strong
1905 * enough to ensure unique signatures, force
1906 * dedup_verify.
1907 */
1908 if (dedup_checksum != ZIO_CHECKSUM_OFF) {
1909 dedup = (wp & WP_DMU_SYNC) ? B_FALSE : B_TRUE;
1910 if (!(zio_checksum_table[checksum].ci_flags &
1911 ZCHECKSUM_FLAG_DEDUP))
1912 dedup_verify = B_TRUE;
1913 }
1914
1915 /*
1916 * Enable nopwrite if we have secure enough checksum
1917 * algorithm (see comment in zio_nop_write) and
1918 * compression is enabled. We don't enable nopwrite if
1919 * dedup is enabled as the two features are mutually
1920 * exclusive.
1921 */
1922 nopwrite = (!dedup && (zio_checksum_table[checksum].ci_flags &
1923 ZCHECKSUM_FLAG_NOPWRITE) &&
1924 compress != ZIO_COMPRESS_OFF && zfs_nopwrite_enabled);
1925 }
1926
1927 zp->zp_checksum = checksum;
1928
1929 /*
1930 * If we're writing a pre-compressed buffer, the compression type we use
1931 * must match the data. If it hasn't been compressed yet, then we should
1932 * use the value dictated by the policies above.
1933 */
1934 zp->zp_compress = override_compress != ZIO_COMPRESS_INHERIT
1935 ? override_compress : compress;
1936 ASSERT3U(zp->zp_compress, !=, ZIO_COMPRESS_INHERIT);
1937
1938 zp->zp_type = (wp & WP_SPILL) ? dn->dn_bonustype : type;
1939 zp->zp_level = level;
1940 zp->zp_copies = MIN(copies, spa_max_replication(os->os_spa));
1941 zp->zp_dedup = dedup;
1942 zp->zp_dedup_verify = dedup && dedup_verify;
1943 zp->zp_nopwrite = nopwrite;
1944 }
1945
1946 int
1947 dmu_offset_next(objset_t *os, uint64_t object, boolean_t hole, uint64_t *off)
1948 {
1949 dnode_t *dn;
1950 int i, err;
1951
1952 err = dnode_hold(os, object, FTAG, &dn);
1953 if (err)
1954 return (err);
1955 /*
1956 * Sync any current changes before
1957 * we go trundling through the block pointers.
1958 */
1959 for (i = 0; i < TXG_SIZE; i++) {
1960 if (list_link_active(&dn->dn_dirty_link[i]))
1961 break;
1962 }
1963 if (i != TXG_SIZE) {
1964 dnode_rele(dn, FTAG);
1965 txg_wait_synced(dmu_objset_pool(os), 0);
1966 err = dnode_hold(os, object, FTAG, &dn);
1967 if (err)
1968 return (err);
1969 }
1970
1971 err = dnode_next_offset(dn, (hole ? DNODE_FIND_HOLE : 0), off, 1, 1, 0);
1972 dnode_rele(dn, FTAG);
1973
1974 return (err);
1975 }
1976
1977 void
1978 __dmu_object_info_from_dnode(dnode_t *dn, dmu_object_info_t *doi)
1979 {
1980 dnode_phys_t *dnp = dn->dn_phys;
1981 int i;
1982
1983 doi->doi_data_block_size = dn->dn_datablksz;
1984 doi->doi_metadata_block_size = dn->dn_indblkshift ?
1985 1ULL << dn->dn_indblkshift : 0;
1986 doi->doi_type = dn->dn_type;
1987 doi->doi_bonus_type = dn->dn_bonustype;
1988 doi->doi_bonus_size = dn->dn_bonuslen;
1989 doi->doi_dnodesize = dn->dn_num_slots << DNODE_SHIFT;
1990 doi->doi_indirection = dn->dn_nlevels;
1991 doi->doi_checksum = dn->dn_checksum;
1992 doi->doi_compress = dn->dn_compress;
1993 doi->doi_nblkptr = dn->dn_nblkptr;
1994 doi->doi_physical_blocks_512 = (DN_USED_BYTES(dnp) + 256) >> 9;
1995 doi->doi_max_offset = (dn->dn_maxblkid + 1) * dn->dn_datablksz;
1996 doi->doi_fill_count = 0;
1997 for (i = 0; i < dnp->dn_nblkptr; i++)
1998 doi->doi_fill_count += BP_GET_FILL(&dnp->dn_blkptr[i]);
1999 }
2000
2001 void
2002 dmu_object_info_from_dnode(dnode_t *dn, dmu_object_info_t *doi)
2003 {
2004 rw_enter(&dn->dn_struct_rwlock, RW_READER);
2005 mutex_enter(&dn->dn_mtx);
2006
2007 __dmu_object_info_from_dnode(dn, doi);
2008
2009 mutex_exit(&dn->dn_mtx);
2010 rw_exit(&dn->dn_struct_rwlock);
2011 }
2012
2013 /*
2014 * Get information on a DMU object.
2015 * If doi is NULL, just indicates whether the object exists.
2016 */
2017 int
2018 dmu_object_info(objset_t *os, uint64_t object, dmu_object_info_t *doi)
2019 {
2020 dnode_t *dn;
2021 int err = dnode_hold(os, object, FTAG, &dn);
2022
2023 if (err)
2024 return (err);
2025
2026 if (doi != NULL)
2027 dmu_object_info_from_dnode(dn, doi);
2028
2029 dnode_rele(dn, FTAG);
2030 return (0);
2031 }
2032
2033 /*
2034 * As above, but faster; can be used when you have a held dbuf in hand.
2035 */
2036 void
2037 dmu_object_info_from_db(dmu_buf_t *db_fake, dmu_object_info_t *doi)
2038 {
2039 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
2040
2041 DB_DNODE_ENTER(db);
2042 dmu_object_info_from_dnode(DB_DNODE(db), doi);
2043 DB_DNODE_EXIT(db);
2044 }
2045
2046 /*
2047 * Faster still when you only care about the size.
2048 * This is specifically optimized for zfs_getattr().
2049 */
2050 void
2051 dmu_object_size_from_db(dmu_buf_t *db_fake, uint32_t *blksize,
2052 u_longlong_t *nblk512)
2053 {
2054 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
2055 dnode_t *dn;
2056
2057 DB_DNODE_ENTER(db);
2058 dn = DB_DNODE(db);
2059
2060 *blksize = dn->dn_datablksz;
2061 /* add in number of slots used for the dnode itself */
2062 *nblk512 = ((DN_USED_BYTES(dn->dn_phys) + SPA_MINBLOCKSIZE/2) >>
2063 SPA_MINBLOCKSHIFT) + dn->dn_num_slots;
2064 DB_DNODE_EXIT(db);
2065 }
2066
2067 void
2068 dmu_object_dnsize_from_db(dmu_buf_t *db_fake, int *dnsize)
2069 {
2070 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
2071 dnode_t *dn;
2072
2073 DB_DNODE_ENTER(db);
2074 dn = DB_DNODE(db);
2075 *dnsize = dn->dn_num_slots << DNODE_SHIFT;
2076 DB_DNODE_EXIT(db);
2077 }
2078
2079 void
2080 byteswap_uint64_array(void *vbuf, size_t size)
2081 {
2082 uint64_t *buf = vbuf;
2083 size_t count = size >> 3;
2084 int i;
2085
2086 ASSERT((size & 7) == 0);
2087
2088 for (i = 0; i < count; i++)
2089 buf[i] = BSWAP_64(buf[i]);
2090 }
2091
2092 void
2093 byteswap_uint32_array(void *vbuf, size_t size)
2094 {
2095 uint32_t *buf = vbuf;
2096 size_t count = size >> 2;
2097 int i;
2098
2099 ASSERT((size & 3) == 0);
2100
2101 for (i = 0; i < count; i++)
2102 buf[i] = BSWAP_32(buf[i]);
2103 }
2104
2105 void
2106 byteswap_uint16_array(void *vbuf, size_t size)
2107 {
2108 uint16_t *buf = vbuf;
2109 size_t count = size >> 1;
2110 int i;
2111
2112 ASSERT((size & 1) == 0);
2113
2114 for (i = 0; i < count; i++)
2115 buf[i] = BSWAP_16(buf[i]);
2116 }
2117
2118 /* ARGSUSED */
2119 void
2120 byteswap_uint8_array(void *vbuf, size_t size)
2121 {
2122 }
2123
2124 void
2125 dmu_init(void)
2126 {
2127 abd_init();
2128 zfs_dbgmsg_init();
2129 sa_cache_init();
2130 xuio_stat_init();
2131 dmu_objset_init();
2132 dnode_init();
2133 zfetch_init();
2134 dmu_tx_init();
2135 l2arc_init();
2136 arc_init();
2137 dbuf_init();
2138 }
2139
2140 void
2141 dmu_fini(void)
2142 {
2143 arc_fini(); /* arc depends on l2arc, so arc must go first */
2144 l2arc_fini();
2145 dmu_tx_fini();
2146 zfetch_fini();
2147 dbuf_fini();
2148 dnode_fini();
2149 dmu_objset_fini();
2150 xuio_stat_fini();
2151 sa_cache_fini();
2152 zfs_dbgmsg_fini();
2153 abd_fini();
2154 }
2155
2156 #if defined(_KERNEL) && defined(HAVE_SPL)
2157 EXPORT_SYMBOL(dmu_bonus_hold);
2158 EXPORT_SYMBOL(dmu_buf_hold_array_by_bonus);
2159 EXPORT_SYMBOL(dmu_buf_rele_array);
2160 EXPORT_SYMBOL(dmu_prefetch);
2161 EXPORT_SYMBOL(dmu_free_range);
2162 EXPORT_SYMBOL(dmu_free_long_range);
2163 EXPORT_SYMBOL(dmu_free_long_object);
2164 EXPORT_SYMBOL(dmu_read);
2165 EXPORT_SYMBOL(dmu_read_by_dnode);
2166 EXPORT_SYMBOL(dmu_write);
2167 EXPORT_SYMBOL(dmu_write_by_dnode);
2168 EXPORT_SYMBOL(dmu_prealloc);
2169 EXPORT_SYMBOL(dmu_object_info);
2170 EXPORT_SYMBOL(dmu_object_info_from_dnode);
2171 EXPORT_SYMBOL(dmu_object_info_from_db);
2172 EXPORT_SYMBOL(dmu_object_size_from_db);
2173 EXPORT_SYMBOL(dmu_object_dnsize_from_db);
2174 EXPORT_SYMBOL(dmu_object_set_blocksize);
2175 EXPORT_SYMBOL(dmu_object_set_checksum);
2176 EXPORT_SYMBOL(dmu_object_set_compress);
2177 EXPORT_SYMBOL(dmu_write_policy);
2178 EXPORT_SYMBOL(dmu_sync);
2179 EXPORT_SYMBOL(dmu_request_arcbuf);
2180 EXPORT_SYMBOL(dmu_return_arcbuf);
2181 EXPORT_SYMBOL(dmu_assign_arcbuf);
2182 EXPORT_SYMBOL(dmu_buf_hold);
2183 EXPORT_SYMBOL(dmu_ot);
2184
2185 module_param(zfs_mdcomp_disable, int, 0644);
2186 MODULE_PARM_DESC(zfs_mdcomp_disable, "Disable meta data compression");
2187
2188 module_param(zfs_nopwrite_enabled, int, 0644);
2189 MODULE_PARM_DESC(zfs_nopwrite_enabled, "Enable NOP writes");
2190
2191 #endif
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