5661 ZFS: "compression = on" should use lz4 if feature is enabled
[unleashed.git] / usr / src / uts / common / fs / zfs / dmu.c
blob98eb40ec8d43bb965a420dd7a68de3664d6fb5ed
1 /*
2 * CDDL HEADER START
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.
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.
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]
19 * CDDL HEADER END
22 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
23 * Copyright (c) 2011, 2014 by Delphix. All rights reserved.
25 /* Copyright (c) 2013 by Saso Kiselkov. All rights reserved. */
26 /* Copyright (c) 2013, Joyent, Inc. All rights reserved. */
27 /* Copyright (c) 2014, Nexenta Systems, Inc. All rights reserved. */
29 #include <sys/dmu.h>
30 #include <sys/dmu_impl.h>
31 #include <sys/dmu_tx.h>
32 #include <sys/dbuf.h>
33 #include <sys/dnode.h>
34 #include <sys/zfs_context.h>
35 #include <sys/dmu_objset.h>
36 #include <sys/dmu_traverse.h>
37 #include <sys/dsl_dataset.h>
38 #include <sys/dsl_dir.h>
39 #include <sys/dsl_pool.h>
40 #include <sys/dsl_synctask.h>
41 #include <sys/dsl_prop.h>
42 #include <sys/dmu_zfetch.h>
43 #include <sys/zfs_ioctl.h>
44 #include <sys/zap.h>
45 #include <sys/zio_checksum.h>
46 #include <sys/zio_compress.h>
47 #include <sys/sa.h>
48 #include <sys/zfeature.h>
49 #ifdef _KERNEL
50 #include <sys/vmsystm.h>
51 #include <sys/zfs_znode.h>
52 #endif
55 * Enable/disable nopwrite feature.
57 int zfs_nopwrite_enabled = 1;
59 const dmu_object_type_info_t dmu_ot[DMU_OT_NUMTYPES] = {
60 { DMU_BSWAP_UINT8, TRUE, "unallocated" },
61 { DMU_BSWAP_ZAP, TRUE, "object directory" },
62 { DMU_BSWAP_UINT64, TRUE, "object array" },
63 { DMU_BSWAP_UINT8, TRUE, "packed nvlist" },
64 { DMU_BSWAP_UINT64, TRUE, "packed nvlist size" },
65 { DMU_BSWAP_UINT64, TRUE, "bpobj" },
66 { DMU_BSWAP_UINT64, TRUE, "bpobj header" },
67 { DMU_BSWAP_UINT64, TRUE, "SPA space map header" },
68 { DMU_BSWAP_UINT64, TRUE, "SPA space map" },
69 { DMU_BSWAP_UINT64, TRUE, "ZIL intent log" },
70 { DMU_BSWAP_DNODE, TRUE, "DMU dnode" },
71 { DMU_BSWAP_OBJSET, TRUE, "DMU objset" },
72 { DMU_BSWAP_UINT64, TRUE, "DSL directory" },
73 { DMU_BSWAP_ZAP, TRUE, "DSL directory child map"},
74 { DMU_BSWAP_ZAP, TRUE, "DSL dataset snap map" },
75 { DMU_BSWAP_ZAP, TRUE, "DSL props" },
76 { DMU_BSWAP_UINT64, TRUE, "DSL dataset" },
77 { DMU_BSWAP_ZNODE, TRUE, "ZFS znode" },
78 { DMU_BSWAP_OLDACL, TRUE, "ZFS V0 ACL" },
79 { DMU_BSWAP_UINT8, FALSE, "ZFS plain file" },
80 { DMU_BSWAP_ZAP, TRUE, "ZFS directory" },
81 { DMU_BSWAP_ZAP, TRUE, "ZFS master node" },
82 { DMU_BSWAP_ZAP, TRUE, "ZFS delete queue" },
83 { DMU_BSWAP_UINT8, FALSE, "zvol object" },
84 { DMU_BSWAP_ZAP, TRUE, "zvol prop" },
85 { DMU_BSWAP_UINT8, FALSE, "other uint8[]" },
86 { DMU_BSWAP_UINT64, FALSE, "other uint64[]" },
87 { DMU_BSWAP_ZAP, TRUE, "other ZAP" },
88 { DMU_BSWAP_ZAP, TRUE, "persistent error log" },
89 { DMU_BSWAP_UINT8, TRUE, "SPA history" },
90 { DMU_BSWAP_UINT64, TRUE, "SPA history offsets" },
91 { DMU_BSWAP_ZAP, TRUE, "Pool properties" },
92 { DMU_BSWAP_ZAP, TRUE, "DSL permissions" },
93 { DMU_BSWAP_ACL, TRUE, "ZFS ACL" },
94 { DMU_BSWAP_UINT8, TRUE, "ZFS SYSACL" },
95 { DMU_BSWAP_UINT8, TRUE, "FUID table" },
96 { DMU_BSWAP_UINT64, TRUE, "FUID table size" },
97 { DMU_BSWAP_ZAP, TRUE, "DSL dataset next clones"},
98 { DMU_BSWAP_ZAP, TRUE, "scan work queue" },
99 { DMU_BSWAP_ZAP, TRUE, "ZFS user/group used" },
100 { DMU_BSWAP_ZAP, TRUE, "ZFS user/group quota" },
101 { DMU_BSWAP_ZAP, TRUE, "snapshot refcount tags"},
102 { DMU_BSWAP_ZAP, TRUE, "DDT ZAP algorithm" },
103 { DMU_BSWAP_ZAP, TRUE, "DDT statistics" },
104 { DMU_BSWAP_UINT8, TRUE, "System attributes" },
105 { DMU_BSWAP_ZAP, TRUE, "SA master node" },
106 { DMU_BSWAP_ZAP, TRUE, "SA attr registration" },
107 { DMU_BSWAP_ZAP, TRUE, "SA attr layouts" },
108 { DMU_BSWAP_ZAP, TRUE, "scan translations" },
109 { DMU_BSWAP_UINT8, FALSE, "deduplicated block" },
110 { DMU_BSWAP_ZAP, TRUE, "DSL deadlist map" },
111 { DMU_BSWAP_UINT64, TRUE, "DSL deadlist map hdr" },
112 { DMU_BSWAP_ZAP, TRUE, "DSL dir clones" },
113 { DMU_BSWAP_UINT64, TRUE, "bpobj subobj" }
116 const dmu_object_byteswap_info_t dmu_ot_byteswap[DMU_BSWAP_NUMFUNCS] = {
117 { byteswap_uint8_array, "uint8" },
118 { byteswap_uint16_array, "uint16" },
119 { byteswap_uint32_array, "uint32" },
120 { byteswap_uint64_array, "uint64" },
121 { zap_byteswap, "zap" },
122 { dnode_buf_byteswap, "dnode" },
123 { dmu_objset_byteswap, "objset" },
124 { zfs_znode_byteswap, "znode" },
125 { zfs_oldacl_byteswap, "oldacl" },
126 { zfs_acl_byteswap, "acl" }
130 dmu_buf_hold_noread(objset_t *os, uint64_t object, uint64_t offset,
131 void *tag, dmu_buf_t **dbp)
133 dnode_t *dn;
134 uint64_t blkid;
135 dmu_buf_impl_t *db;
136 int err;
138 err = dnode_hold(os, object, FTAG, &dn);
139 if (err)
140 return (err);
141 blkid = dbuf_whichblock(dn, offset);
142 rw_enter(&dn->dn_struct_rwlock, RW_READER);
143 db = dbuf_hold(dn, blkid, tag);
144 rw_exit(&dn->dn_struct_rwlock);
145 dnode_rele(dn, FTAG);
147 if (db == NULL) {
148 *dbp = NULL;
149 return (SET_ERROR(EIO));
152 *dbp = &db->db;
153 return (err);
157 dmu_buf_hold(objset_t *os, uint64_t object, uint64_t offset,
158 void *tag, dmu_buf_t **dbp, int flags)
160 int err;
161 int db_flags = DB_RF_CANFAIL;
163 if (flags & DMU_READ_NO_PREFETCH)
164 db_flags |= DB_RF_NOPREFETCH;
166 err = dmu_buf_hold_noread(os, object, offset, tag, dbp);
167 if (err == 0) {
168 dmu_buf_impl_t *db = (dmu_buf_impl_t *)(*dbp);
169 err = dbuf_read(db, NULL, db_flags);
170 if (err != 0) {
171 dbuf_rele(db, tag);
172 *dbp = NULL;
176 return (err);
180 dmu_bonus_max(void)
182 return (DN_MAX_BONUSLEN);
186 dmu_set_bonus(dmu_buf_t *db_fake, int newsize, dmu_tx_t *tx)
188 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
189 dnode_t *dn;
190 int error;
192 DB_DNODE_ENTER(db);
193 dn = DB_DNODE(db);
195 if (dn->dn_bonus != db) {
196 error = SET_ERROR(EINVAL);
197 } else if (newsize < 0 || newsize > db_fake->db_size) {
198 error = SET_ERROR(EINVAL);
199 } else {
200 dnode_setbonuslen(dn, newsize, tx);
201 error = 0;
204 DB_DNODE_EXIT(db);
205 return (error);
209 dmu_set_bonustype(dmu_buf_t *db_fake, dmu_object_type_t type, dmu_tx_t *tx)
211 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
212 dnode_t *dn;
213 int error;
215 DB_DNODE_ENTER(db);
216 dn = DB_DNODE(db);
218 if (!DMU_OT_IS_VALID(type)) {
219 error = SET_ERROR(EINVAL);
220 } else if (dn->dn_bonus != db) {
221 error = SET_ERROR(EINVAL);
222 } else {
223 dnode_setbonus_type(dn, type, tx);
224 error = 0;
227 DB_DNODE_EXIT(db);
228 return (error);
231 dmu_object_type_t
232 dmu_get_bonustype(dmu_buf_t *db_fake)
234 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
235 dnode_t *dn;
236 dmu_object_type_t type;
238 DB_DNODE_ENTER(db);
239 dn = DB_DNODE(db);
240 type = dn->dn_bonustype;
241 DB_DNODE_EXIT(db);
243 return (type);
247 dmu_rm_spill(objset_t *os, uint64_t object, dmu_tx_t *tx)
249 dnode_t *dn;
250 int error;
252 error = dnode_hold(os, object, FTAG, &dn);
253 dbuf_rm_spill(dn, tx);
254 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
255 dnode_rm_spill(dn, tx);
256 rw_exit(&dn->dn_struct_rwlock);
257 dnode_rele(dn, FTAG);
258 return (error);
262 * returns ENOENT, EIO, or 0.
265 dmu_bonus_hold(objset_t *os, uint64_t object, void *tag, dmu_buf_t **dbp)
267 dnode_t *dn;
268 dmu_buf_impl_t *db;
269 int error;
271 error = dnode_hold(os, object, FTAG, &dn);
272 if (error)
273 return (error);
275 rw_enter(&dn->dn_struct_rwlock, RW_READER);
276 if (dn->dn_bonus == NULL) {
277 rw_exit(&dn->dn_struct_rwlock);
278 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
279 if (dn->dn_bonus == NULL)
280 dbuf_create_bonus(dn);
282 db = dn->dn_bonus;
284 /* as long as the bonus buf is held, the dnode will be held */
285 if (refcount_add(&db->db_holds, tag) == 1) {
286 VERIFY(dnode_add_ref(dn, db));
287 atomic_inc_32(&dn->dn_dbufs_count);
291 * Wait to drop dn_struct_rwlock until after adding the bonus dbuf's
292 * hold and incrementing the dbuf count to ensure that dnode_move() sees
293 * a dnode hold for every dbuf.
295 rw_exit(&dn->dn_struct_rwlock);
297 dnode_rele(dn, FTAG);
299 VERIFY(0 == dbuf_read(db, NULL, DB_RF_MUST_SUCCEED | DB_RF_NOPREFETCH));
301 *dbp = &db->db;
302 return (0);
306 * returns ENOENT, EIO, or 0.
308 * This interface will allocate a blank spill dbuf when a spill blk
309 * doesn't already exist on the dnode.
311 * if you only want to find an already existing spill db, then
312 * dmu_spill_hold_existing() should be used.
315 dmu_spill_hold_by_dnode(dnode_t *dn, uint32_t flags, void *tag, dmu_buf_t **dbp)
317 dmu_buf_impl_t *db = NULL;
318 int err;
320 if ((flags & DB_RF_HAVESTRUCT) == 0)
321 rw_enter(&dn->dn_struct_rwlock, RW_READER);
323 db = dbuf_hold(dn, DMU_SPILL_BLKID, tag);
325 if ((flags & DB_RF_HAVESTRUCT) == 0)
326 rw_exit(&dn->dn_struct_rwlock);
328 ASSERT(db != NULL);
329 err = dbuf_read(db, NULL, flags);
330 if (err == 0)
331 *dbp = &db->db;
332 else
333 dbuf_rele(db, tag);
334 return (err);
338 dmu_spill_hold_existing(dmu_buf_t *bonus, void *tag, dmu_buf_t **dbp)
340 dmu_buf_impl_t *db = (dmu_buf_impl_t *)bonus;
341 dnode_t *dn;
342 int err;
344 DB_DNODE_ENTER(db);
345 dn = DB_DNODE(db);
347 if (spa_version(dn->dn_objset->os_spa) < SPA_VERSION_SA) {
348 err = SET_ERROR(EINVAL);
349 } else {
350 rw_enter(&dn->dn_struct_rwlock, RW_READER);
352 if (!dn->dn_have_spill) {
353 err = SET_ERROR(ENOENT);
354 } else {
355 err = dmu_spill_hold_by_dnode(dn,
356 DB_RF_HAVESTRUCT | DB_RF_CANFAIL, tag, dbp);
359 rw_exit(&dn->dn_struct_rwlock);
362 DB_DNODE_EXIT(db);
363 return (err);
367 dmu_spill_hold_by_bonus(dmu_buf_t *bonus, void *tag, dmu_buf_t **dbp)
369 dmu_buf_impl_t *db = (dmu_buf_impl_t *)bonus;
370 dnode_t *dn;
371 int err;
373 DB_DNODE_ENTER(db);
374 dn = DB_DNODE(db);
375 err = dmu_spill_hold_by_dnode(dn, DB_RF_CANFAIL, tag, dbp);
376 DB_DNODE_EXIT(db);
378 return (err);
382 * Note: longer-term, we should modify all of the dmu_buf_*() interfaces
383 * to take a held dnode rather than <os, object> -- the lookup is wasteful,
384 * and can induce severe lock contention when writing to several files
385 * whose dnodes are in the same block.
387 static int
388 dmu_buf_hold_array_by_dnode(dnode_t *dn, uint64_t offset, uint64_t length,
389 int read, void *tag, int *numbufsp, dmu_buf_t ***dbpp, uint32_t flags)
391 dmu_buf_t **dbp;
392 uint64_t blkid, nblks, i;
393 uint32_t dbuf_flags;
394 int err;
395 zio_t *zio;
397 ASSERT(length <= DMU_MAX_ACCESS);
399 dbuf_flags = DB_RF_CANFAIL | DB_RF_NEVERWAIT | DB_RF_HAVESTRUCT;
400 if (flags & DMU_READ_NO_PREFETCH || length > zfetch_array_rd_sz)
401 dbuf_flags |= DB_RF_NOPREFETCH;
403 rw_enter(&dn->dn_struct_rwlock, RW_READER);
404 if (dn->dn_datablkshift) {
405 int blkshift = dn->dn_datablkshift;
406 nblks = (P2ROUNDUP(offset+length, 1ULL<<blkshift) -
407 P2ALIGN(offset, 1ULL<<blkshift)) >> blkshift;
408 } else {
409 if (offset + length > dn->dn_datablksz) {
410 zfs_panic_recover("zfs: accessing past end of object "
411 "%llx/%llx (size=%u access=%llu+%llu)",
412 (longlong_t)dn->dn_objset->
413 os_dsl_dataset->ds_object,
414 (longlong_t)dn->dn_object, dn->dn_datablksz,
415 (longlong_t)offset, (longlong_t)length);
416 rw_exit(&dn->dn_struct_rwlock);
417 return (SET_ERROR(EIO));
419 nblks = 1;
421 dbp = kmem_zalloc(sizeof (dmu_buf_t *) * nblks, KM_SLEEP);
423 zio = zio_root(dn->dn_objset->os_spa, NULL, NULL, ZIO_FLAG_CANFAIL);
424 blkid = dbuf_whichblock(dn, offset);
425 for (i = 0; i < nblks; i++) {
426 dmu_buf_impl_t *db = dbuf_hold(dn, blkid+i, tag);
427 if (db == NULL) {
428 rw_exit(&dn->dn_struct_rwlock);
429 dmu_buf_rele_array(dbp, nblks, tag);
430 zio_nowait(zio);
431 return (SET_ERROR(EIO));
433 /* initiate async i/o */
434 if (read) {
435 (void) dbuf_read(db, zio, dbuf_flags);
437 dbp[i] = &db->db;
439 rw_exit(&dn->dn_struct_rwlock);
441 /* wait for async i/o */
442 err = zio_wait(zio);
443 if (err) {
444 dmu_buf_rele_array(dbp, nblks, tag);
445 return (err);
448 /* wait for other io to complete */
449 if (read) {
450 for (i = 0; i < nblks; i++) {
451 dmu_buf_impl_t *db = (dmu_buf_impl_t *)dbp[i];
452 mutex_enter(&db->db_mtx);
453 while (db->db_state == DB_READ ||
454 db->db_state == DB_FILL)
455 cv_wait(&db->db_changed, &db->db_mtx);
456 if (db->db_state == DB_UNCACHED)
457 err = SET_ERROR(EIO);
458 mutex_exit(&db->db_mtx);
459 if (err) {
460 dmu_buf_rele_array(dbp, nblks, tag);
461 return (err);
466 *numbufsp = nblks;
467 *dbpp = dbp;
468 return (0);
471 static int
472 dmu_buf_hold_array(objset_t *os, uint64_t object, uint64_t offset,
473 uint64_t length, int read, void *tag, int *numbufsp, dmu_buf_t ***dbpp)
475 dnode_t *dn;
476 int err;
478 err = dnode_hold(os, object, FTAG, &dn);
479 if (err)
480 return (err);
482 err = dmu_buf_hold_array_by_dnode(dn, offset, length, read, tag,
483 numbufsp, dbpp, DMU_READ_PREFETCH);
485 dnode_rele(dn, FTAG);
487 return (err);
491 dmu_buf_hold_array_by_bonus(dmu_buf_t *db_fake, uint64_t offset,
492 uint64_t length, int read, void *tag, int *numbufsp, dmu_buf_t ***dbpp)
494 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
495 dnode_t *dn;
496 int err;
498 DB_DNODE_ENTER(db);
499 dn = DB_DNODE(db);
500 err = dmu_buf_hold_array_by_dnode(dn, offset, length, read, tag,
501 numbufsp, dbpp, DMU_READ_PREFETCH);
502 DB_DNODE_EXIT(db);
504 return (err);
507 void
508 dmu_buf_rele_array(dmu_buf_t **dbp_fake, int numbufs, void *tag)
510 int i;
511 dmu_buf_impl_t **dbp = (dmu_buf_impl_t **)dbp_fake;
513 if (numbufs == 0)
514 return;
516 for (i = 0; i < numbufs; i++) {
517 if (dbp[i])
518 dbuf_rele(dbp[i], tag);
521 kmem_free(dbp, sizeof (dmu_buf_t *) * numbufs);
525 * Issue prefetch i/os for the given blocks.
527 * Note: The assumption is that we *know* these blocks will be needed
528 * almost immediately. Therefore, the prefetch i/os will be issued at
529 * ZIO_PRIORITY_SYNC_READ
531 * Note: indirect blocks and other metadata will be read synchronously,
532 * causing this function to block if they are not already cached.
534 void
535 dmu_prefetch(objset_t *os, uint64_t object, uint64_t offset, uint64_t len)
537 dnode_t *dn;
538 uint64_t blkid;
539 int nblks, err;
541 if (zfs_prefetch_disable)
542 return;
544 if (len == 0) { /* they're interested in the bonus buffer */
545 dn = DMU_META_DNODE(os);
547 if (object == 0 || object >= DN_MAX_OBJECT)
548 return;
550 rw_enter(&dn->dn_struct_rwlock, RW_READER);
551 blkid = dbuf_whichblock(dn, object * sizeof (dnode_phys_t));
552 dbuf_prefetch(dn, blkid, ZIO_PRIORITY_SYNC_READ);
553 rw_exit(&dn->dn_struct_rwlock);
554 return;
558 * XXX - Note, if the dnode for the requested object is not
559 * already cached, we will do a *synchronous* read in the
560 * dnode_hold() call. The same is true for any indirects.
562 err = dnode_hold(os, object, FTAG, &dn);
563 if (err != 0)
564 return;
566 rw_enter(&dn->dn_struct_rwlock, RW_READER);
567 if (dn->dn_datablkshift) {
568 int blkshift = dn->dn_datablkshift;
569 nblks = (P2ROUNDUP(offset + len, 1 << blkshift) -
570 P2ALIGN(offset, 1 << blkshift)) >> blkshift;
571 } else {
572 nblks = (offset < dn->dn_datablksz);
575 if (nblks != 0) {
576 blkid = dbuf_whichblock(dn, offset);
577 for (int i = 0; i < nblks; i++)
578 dbuf_prefetch(dn, blkid + i, ZIO_PRIORITY_SYNC_READ);
581 rw_exit(&dn->dn_struct_rwlock);
583 dnode_rele(dn, FTAG);
587 * Get the next "chunk" of file data to free. We traverse the file from
588 * the end so that the file gets shorter over time (if we crashes in the
589 * middle, this will leave us in a better state). We find allocated file
590 * data by simply searching the allocated level 1 indirects.
592 * On input, *start should be the first offset that does not need to be
593 * freed (e.g. "offset + length"). On return, *start will be the first
594 * offset that should be freed.
596 static int
597 get_next_chunk(dnode_t *dn, uint64_t *start, uint64_t minimum)
599 uint64_t maxblks = DMU_MAX_ACCESS >> (dn->dn_indblkshift + 1);
600 /* bytes of data covered by a level-1 indirect block */
601 uint64_t iblkrange =
602 dn->dn_datablksz * EPB(dn->dn_indblkshift, SPA_BLKPTRSHIFT);
604 ASSERT3U(minimum, <=, *start);
606 if (*start - minimum <= iblkrange * maxblks) {
607 *start = minimum;
608 return (0);
610 ASSERT(ISP2(iblkrange));
612 for (uint64_t blks = 0; *start > minimum && blks < maxblks; blks++) {
613 int err;
616 * dnode_next_offset(BACKWARDS) will find an allocated L1
617 * indirect block at or before the input offset. We must
618 * decrement *start so that it is at the end of the region
619 * to search.
621 (*start)--;
622 err = dnode_next_offset(dn,
623 DNODE_FIND_BACKWARDS, start, 2, 1, 0);
625 /* if there are no indirect blocks before start, we are done */
626 if (err == ESRCH) {
627 *start = minimum;
628 break;
629 } else if (err != 0) {
630 return (err);
633 /* set start to the beginning of this L1 indirect */
634 *start = P2ALIGN(*start, iblkrange);
636 if (*start < minimum)
637 *start = minimum;
638 return (0);
641 static int
642 dmu_free_long_range_impl(objset_t *os, dnode_t *dn, uint64_t offset,
643 uint64_t length)
645 uint64_t object_size = (dn->dn_maxblkid + 1) * dn->dn_datablksz;
646 int err;
648 if (offset >= object_size)
649 return (0);
651 if (length == DMU_OBJECT_END || offset + length > object_size)
652 length = object_size - offset;
654 while (length != 0) {
655 uint64_t chunk_end, chunk_begin;
657 chunk_end = chunk_begin = offset + length;
659 /* move chunk_begin backwards to the beginning of this chunk */
660 err = get_next_chunk(dn, &chunk_begin, offset);
661 if (err)
662 return (err);
663 ASSERT3U(chunk_begin, >=, offset);
664 ASSERT3U(chunk_begin, <=, chunk_end);
666 dmu_tx_t *tx = dmu_tx_create(os);
667 dmu_tx_hold_free(tx, dn->dn_object,
668 chunk_begin, chunk_end - chunk_begin);
671 * Mark this transaction as typically resulting in a net
672 * reduction in space used.
674 dmu_tx_mark_netfree(tx);
675 err = dmu_tx_assign(tx, TXG_WAIT);
676 if (err) {
677 dmu_tx_abort(tx);
678 return (err);
680 dnode_free_range(dn, chunk_begin, chunk_end - chunk_begin, tx);
681 dmu_tx_commit(tx);
683 length -= chunk_end - chunk_begin;
685 return (0);
689 dmu_free_long_range(objset_t *os, uint64_t object,
690 uint64_t offset, uint64_t length)
692 dnode_t *dn;
693 int err;
695 err = dnode_hold(os, object, FTAG, &dn);
696 if (err != 0)
697 return (err);
698 err = dmu_free_long_range_impl(os, dn, offset, length);
701 * It is important to zero out the maxblkid when freeing the entire
702 * file, so that (a) subsequent calls to dmu_free_long_range_impl()
703 * will take the fast path, and (b) dnode_reallocate() can verify
704 * that the entire file has been freed.
706 if (err == 0 && offset == 0 && length == DMU_OBJECT_END)
707 dn->dn_maxblkid = 0;
709 dnode_rele(dn, FTAG);
710 return (err);
714 dmu_free_long_object(objset_t *os, uint64_t object)
716 dmu_tx_t *tx;
717 int err;
719 err = dmu_free_long_range(os, object, 0, DMU_OBJECT_END);
720 if (err != 0)
721 return (err);
723 tx = dmu_tx_create(os);
724 dmu_tx_hold_bonus(tx, object);
725 dmu_tx_hold_free(tx, object, 0, DMU_OBJECT_END);
726 dmu_tx_mark_netfree(tx);
727 err = dmu_tx_assign(tx, TXG_WAIT);
728 if (err == 0) {
729 err = dmu_object_free(os, object, tx);
730 dmu_tx_commit(tx);
731 } else {
732 dmu_tx_abort(tx);
735 return (err);
739 dmu_free_range(objset_t *os, uint64_t object, uint64_t offset,
740 uint64_t size, dmu_tx_t *tx)
742 dnode_t *dn;
743 int err = dnode_hold(os, object, FTAG, &dn);
744 if (err)
745 return (err);
746 ASSERT(offset < UINT64_MAX);
747 ASSERT(size == -1ULL || size <= UINT64_MAX - offset);
748 dnode_free_range(dn, offset, size, tx);
749 dnode_rele(dn, FTAG);
750 return (0);
754 dmu_read(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
755 void *buf, uint32_t flags)
757 dnode_t *dn;
758 dmu_buf_t **dbp;
759 int numbufs, err;
761 err = dnode_hold(os, object, FTAG, &dn);
762 if (err)
763 return (err);
766 * Deal with odd block sizes, where there can't be data past the first
767 * block. If we ever do the tail block optimization, we will need to
768 * handle that here as well.
770 if (dn->dn_maxblkid == 0) {
771 int newsz = offset > dn->dn_datablksz ? 0 :
772 MIN(size, dn->dn_datablksz - offset);
773 bzero((char *)buf + newsz, size - newsz);
774 size = newsz;
777 while (size > 0) {
778 uint64_t mylen = MIN(size, DMU_MAX_ACCESS / 2);
779 int i;
782 * NB: we could do this block-at-a-time, but it's nice
783 * to be reading in parallel.
785 err = dmu_buf_hold_array_by_dnode(dn, offset, mylen,
786 TRUE, FTAG, &numbufs, &dbp, flags);
787 if (err)
788 break;
790 for (i = 0; i < numbufs; i++) {
791 int tocpy;
792 int bufoff;
793 dmu_buf_t *db = dbp[i];
795 ASSERT(size > 0);
797 bufoff = offset - db->db_offset;
798 tocpy = (int)MIN(db->db_size - bufoff, size);
800 bcopy((char *)db->db_data + bufoff, buf, tocpy);
802 offset += tocpy;
803 size -= tocpy;
804 buf = (char *)buf + tocpy;
806 dmu_buf_rele_array(dbp, numbufs, FTAG);
808 dnode_rele(dn, FTAG);
809 return (err);
812 void
813 dmu_write(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
814 const void *buf, dmu_tx_t *tx)
816 dmu_buf_t **dbp;
817 int numbufs, i;
819 if (size == 0)
820 return;
822 VERIFY(0 == dmu_buf_hold_array(os, object, offset, size,
823 FALSE, FTAG, &numbufs, &dbp));
825 for (i = 0; i < numbufs; i++) {
826 int tocpy;
827 int bufoff;
828 dmu_buf_t *db = dbp[i];
830 ASSERT(size > 0);
832 bufoff = offset - db->db_offset;
833 tocpy = (int)MIN(db->db_size - bufoff, size);
835 ASSERT(i == 0 || i == numbufs-1 || tocpy == db->db_size);
837 if (tocpy == db->db_size)
838 dmu_buf_will_fill(db, tx);
839 else
840 dmu_buf_will_dirty(db, tx);
842 bcopy(buf, (char *)db->db_data + bufoff, tocpy);
844 if (tocpy == db->db_size)
845 dmu_buf_fill_done(db, tx);
847 offset += tocpy;
848 size -= tocpy;
849 buf = (char *)buf + tocpy;
851 dmu_buf_rele_array(dbp, numbufs, FTAG);
854 void
855 dmu_prealloc(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
856 dmu_tx_t *tx)
858 dmu_buf_t **dbp;
859 int numbufs, i;
861 if (size == 0)
862 return;
864 VERIFY(0 == dmu_buf_hold_array(os, object, offset, size,
865 FALSE, FTAG, &numbufs, &dbp));
867 for (i = 0; i < numbufs; i++) {
868 dmu_buf_t *db = dbp[i];
870 dmu_buf_will_not_fill(db, tx);
872 dmu_buf_rele_array(dbp, numbufs, FTAG);
875 void
876 dmu_write_embedded(objset_t *os, uint64_t object, uint64_t offset,
877 void *data, uint8_t etype, uint8_t comp, int uncompressed_size,
878 int compressed_size, int byteorder, dmu_tx_t *tx)
880 dmu_buf_t *db;
882 ASSERT3U(etype, <, NUM_BP_EMBEDDED_TYPES);
883 ASSERT3U(comp, <, ZIO_COMPRESS_FUNCTIONS);
884 VERIFY0(dmu_buf_hold_noread(os, object, offset,
885 FTAG, &db));
887 dmu_buf_write_embedded(db,
888 data, (bp_embedded_type_t)etype, (enum zio_compress)comp,
889 uncompressed_size, compressed_size, byteorder, tx);
891 dmu_buf_rele(db, FTAG);
895 * DMU support for xuio
897 kstat_t *xuio_ksp = NULL;
900 dmu_xuio_init(xuio_t *xuio, int nblk)
902 dmu_xuio_t *priv;
903 uio_t *uio = &xuio->xu_uio;
905 uio->uio_iovcnt = nblk;
906 uio->uio_iov = kmem_zalloc(nblk * sizeof (iovec_t), KM_SLEEP);
908 priv = kmem_zalloc(sizeof (dmu_xuio_t), KM_SLEEP);
909 priv->cnt = nblk;
910 priv->bufs = kmem_zalloc(nblk * sizeof (arc_buf_t *), KM_SLEEP);
911 priv->iovp = uio->uio_iov;
912 XUIO_XUZC_PRIV(xuio) = priv;
914 if (XUIO_XUZC_RW(xuio) == UIO_READ)
915 XUIOSTAT_INCR(xuiostat_onloan_rbuf, nblk);
916 else
917 XUIOSTAT_INCR(xuiostat_onloan_wbuf, nblk);
919 return (0);
922 void
923 dmu_xuio_fini(xuio_t *xuio)
925 dmu_xuio_t *priv = XUIO_XUZC_PRIV(xuio);
926 int nblk = priv->cnt;
928 kmem_free(priv->iovp, nblk * sizeof (iovec_t));
929 kmem_free(priv->bufs, nblk * sizeof (arc_buf_t *));
930 kmem_free(priv, sizeof (dmu_xuio_t));
932 if (XUIO_XUZC_RW(xuio) == UIO_READ)
933 XUIOSTAT_INCR(xuiostat_onloan_rbuf, -nblk);
934 else
935 XUIOSTAT_INCR(xuiostat_onloan_wbuf, -nblk);
939 * Initialize iov[priv->next] and priv->bufs[priv->next] with { off, n, abuf }
940 * and increase priv->next by 1.
943 dmu_xuio_add(xuio_t *xuio, arc_buf_t *abuf, offset_t off, size_t n)
945 struct iovec *iov;
946 uio_t *uio = &xuio->xu_uio;
947 dmu_xuio_t *priv = XUIO_XUZC_PRIV(xuio);
948 int i = priv->next++;
950 ASSERT(i < priv->cnt);
951 ASSERT(off + n <= arc_buf_size(abuf));
952 iov = uio->uio_iov + i;
953 iov->iov_base = (char *)abuf->b_data + off;
954 iov->iov_len = n;
955 priv->bufs[i] = abuf;
956 return (0);
960 dmu_xuio_cnt(xuio_t *xuio)
962 dmu_xuio_t *priv = XUIO_XUZC_PRIV(xuio);
963 return (priv->cnt);
966 arc_buf_t *
967 dmu_xuio_arcbuf(xuio_t *xuio, int i)
969 dmu_xuio_t *priv = XUIO_XUZC_PRIV(xuio);
971 ASSERT(i < priv->cnt);
972 return (priv->bufs[i]);
975 void
976 dmu_xuio_clear(xuio_t *xuio, int i)
978 dmu_xuio_t *priv = XUIO_XUZC_PRIV(xuio);
980 ASSERT(i < priv->cnt);
981 priv->bufs[i] = NULL;
984 static void
985 xuio_stat_init(void)
987 xuio_ksp = kstat_create("zfs", 0, "xuio_stats", "misc",
988 KSTAT_TYPE_NAMED, sizeof (xuio_stats) / sizeof (kstat_named_t),
989 KSTAT_FLAG_VIRTUAL);
990 if (xuio_ksp != NULL) {
991 xuio_ksp->ks_data = &xuio_stats;
992 kstat_install(xuio_ksp);
996 static void
997 xuio_stat_fini(void)
999 if (xuio_ksp != NULL) {
1000 kstat_delete(xuio_ksp);
1001 xuio_ksp = NULL;
1005 void
1006 xuio_stat_wbuf_copied()
1008 XUIOSTAT_BUMP(xuiostat_wbuf_copied);
1011 void
1012 xuio_stat_wbuf_nocopy()
1014 XUIOSTAT_BUMP(xuiostat_wbuf_nocopy);
1017 #ifdef _KERNEL
1018 static int
1019 dmu_read_uio_dnode(dnode_t *dn, uio_t *uio, uint64_t size)
1021 dmu_buf_t **dbp;
1022 int numbufs, i, err;
1023 xuio_t *xuio = NULL;
1026 * NB: we could do this block-at-a-time, but it's nice
1027 * to be reading in parallel.
1029 err = dmu_buf_hold_array_by_dnode(dn, uio->uio_loffset, size,
1030 TRUE, FTAG, &numbufs, &dbp, 0);
1031 if (err)
1032 return (err);
1034 if (uio->uio_extflg == UIO_XUIO)
1035 xuio = (xuio_t *)uio;
1037 for (i = 0; i < numbufs; i++) {
1038 int tocpy;
1039 int bufoff;
1040 dmu_buf_t *db = dbp[i];
1042 ASSERT(size > 0);
1044 bufoff = uio->uio_loffset - db->db_offset;
1045 tocpy = (int)MIN(db->db_size - bufoff, size);
1047 if (xuio) {
1048 dmu_buf_impl_t *dbi = (dmu_buf_impl_t *)db;
1049 arc_buf_t *dbuf_abuf = dbi->db_buf;
1050 arc_buf_t *abuf = dbuf_loan_arcbuf(dbi);
1051 err = dmu_xuio_add(xuio, abuf, bufoff, tocpy);
1052 if (!err) {
1053 uio->uio_resid -= tocpy;
1054 uio->uio_loffset += tocpy;
1057 if (abuf == dbuf_abuf)
1058 XUIOSTAT_BUMP(xuiostat_rbuf_nocopy);
1059 else
1060 XUIOSTAT_BUMP(xuiostat_rbuf_copied);
1061 } else {
1062 err = uiomove((char *)db->db_data + bufoff, tocpy,
1063 UIO_READ, uio);
1065 if (err)
1066 break;
1068 size -= tocpy;
1070 dmu_buf_rele_array(dbp, numbufs, FTAG);
1072 return (err);
1076 * Read 'size' bytes into the uio buffer.
1077 * From object zdb->db_object.
1078 * Starting at offset uio->uio_loffset.
1080 * If the caller already has a dbuf in the target object
1081 * (e.g. its bonus buffer), this routine is faster than dmu_read_uio(),
1082 * because we don't have to find the dnode_t for the object.
1085 dmu_read_uio_dbuf(dmu_buf_t *zdb, uio_t *uio, uint64_t size)
1087 dmu_buf_impl_t *db = (dmu_buf_impl_t *)zdb;
1088 dnode_t *dn;
1089 int err;
1091 if (size == 0)
1092 return (0);
1094 DB_DNODE_ENTER(db);
1095 dn = DB_DNODE(db);
1096 err = dmu_read_uio_dnode(dn, uio, size);
1097 DB_DNODE_EXIT(db);
1099 return (err);
1103 * Read 'size' bytes into the uio buffer.
1104 * From the specified object
1105 * Starting at offset uio->uio_loffset.
1108 dmu_read_uio(objset_t *os, uint64_t object, uio_t *uio, uint64_t size)
1110 dnode_t *dn;
1111 int err;
1113 if (size == 0)
1114 return (0);
1116 err = dnode_hold(os, object, FTAG, &dn);
1117 if (err)
1118 return (err);
1120 err = dmu_read_uio_dnode(dn, uio, size);
1122 dnode_rele(dn, FTAG);
1124 return (err);
1127 static int
1128 dmu_write_uio_dnode(dnode_t *dn, uio_t *uio, uint64_t size, dmu_tx_t *tx)
1130 dmu_buf_t **dbp;
1131 int numbufs;
1132 int err = 0;
1133 int i;
1135 err = dmu_buf_hold_array_by_dnode(dn, uio->uio_loffset, size,
1136 FALSE, FTAG, &numbufs, &dbp, DMU_READ_PREFETCH);
1137 if (err)
1138 return (err);
1140 for (i = 0; i < numbufs; i++) {
1141 int tocpy;
1142 int bufoff;
1143 dmu_buf_t *db = dbp[i];
1145 ASSERT(size > 0);
1147 bufoff = uio->uio_loffset - db->db_offset;
1148 tocpy = (int)MIN(db->db_size - bufoff, size);
1150 ASSERT(i == 0 || i == numbufs-1 || tocpy == db->db_size);
1152 if (tocpy == db->db_size)
1153 dmu_buf_will_fill(db, tx);
1154 else
1155 dmu_buf_will_dirty(db, tx);
1158 * XXX uiomove could block forever (eg. nfs-backed
1159 * pages). There needs to be a uiolockdown() function
1160 * to lock the pages in memory, so that uiomove won't
1161 * block.
1163 err = uiomove((char *)db->db_data + bufoff, tocpy,
1164 UIO_WRITE, uio);
1166 if (tocpy == db->db_size)
1167 dmu_buf_fill_done(db, tx);
1169 if (err)
1170 break;
1172 size -= tocpy;
1175 dmu_buf_rele_array(dbp, numbufs, FTAG);
1176 return (err);
1180 * Write 'size' bytes from the uio buffer.
1181 * To object zdb->db_object.
1182 * Starting at offset uio->uio_loffset.
1184 * If the caller already has a dbuf in the target object
1185 * (e.g. its bonus buffer), this routine is faster than dmu_write_uio(),
1186 * because we don't have to find the dnode_t for the object.
1189 dmu_write_uio_dbuf(dmu_buf_t *zdb, uio_t *uio, uint64_t size,
1190 dmu_tx_t *tx)
1192 dmu_buf_impl_t *db = (dmu_buf_impl_t *)zdb;
1193 dnode_t *dn;
1194 int err;
1196 if (size == 0)
1197 return (0);
1199 DB_DNODE_ENTER(db);
1200 dn = DB_DNODE(db);
1201 err = dmu_write_uio_dnode(dn, uio, size, tx);
1202 DB_DNODE_EXIT(db);
1204 return (err);
1208 * Write 'size' bytes from the uio buffer.
1209 * To the specified object.
1210 * Starting at offset uio->uio_loffset.
1213 dmu_write_uio(objset_t *os, uint64_t object, uio_t *uio, uint64_t size,
1214 dmu_tx_t *tx)
1216 dnode_t *dn;
1217 int err;
1219 if (size == 0)
1220 return (0);
1222 err = dnode_hold(os, object, FTAG, &dn);
1223 if (err)
1224 return (err);
1226 err = dmu_write_uio_dnode(dn, uio, size, tx);
1228 dnode_rele(dn, FTAG);
1230 return (err);
1234 dmu_write_pages(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
1235 page_t *pp, dmu_tx_t *tx)
1237 dmu_buf_t **dbp;
1238 int numbufs, i;
1239 int err;
1241 if (size == 0)
1242 return (0);
1244 err = dmu_buf_hold_array(os, object, offset, size,
1245 FALSE, FTAG, &numbufs, &dbp);
1246 if (err)
1247 return (err);
1249 for (i = 0; i < numbufs; i++) {
1250 int tocpy, copied, thiscpy;
1251 int bufoff;
1252 dmu_buf_t *db = dbp[i];
1253 caddr_t va;
1255 ASSERT(size > 0);
1256 ASSERT3U(db->db_size, >=, PAGESIZE);
1258 bufoff = offset - db->db_offset;
1259 tocpy = (int)MIN(db->db_size - bufoff, size);
1261 ASSERT(i == 0 || i == numbufs-1 || tocpy == db->db_size);
1263 if (tocpy == db->db_size)
1264 dmu_buf_will_fill(db, tx);
1265 else
1266 dmu_buf_will_dirty(db, tx);
1268 for (copied = 0; copied < tocpy; copied += PAGESIZE) {
1269 ASSERT3U(pp->p_offset, ==, db->db_offset + bufoff);
1270 thiscpy = MIN(PAGESIZE, tocpy - copied);
1271 va = zfs_map_page(pp, S_READ);
1272 bcopy(va, (char *)db->db_data + bufoff, thiscpy);
1273 zfs_unmap_page(pp, va);
1274 pp = pp->p_next;
1275 bufoff += PAGESIZE;
1278 if (tocpy == db->db_size)
1279 dmu_buf_fill_done(db, tx);
1281 offset += tocpy;
1282 size -= tocpy;
1284 dmu_buf_rele_array(dbp, numbufs, FTAG);
1285 return (err);
1287 #endif
1290 * Allocate a loaned anonymous arc buffer.
1292 arc_buf_t *
1293 dmu_request_arcbuf(dmu_buf_t *handle, int size)
1295 dmu_buf_impl_t *db = (dmu_buf_impl_t *)handle;
1297 return (arc_loan_buf(db->db_objset->os_spa, size));
1301 * Free a loaned arc buffer.
1303 void
1304 dmu_return_arcbuf(arc_buf_t *buf)
1306 arc_return_buf(buf, FTAG);
1307 VERIFY(arc_buf_remove_ref(buf, FTAG));
1311 * When possible directly assign passed loaned arc buffer to a dbuf.
1312 * If this is not possible copy the contents of passed arc buf via
1313 * dmu_write().
1315 void
1316 dmu_assign_arcbuf(dmu_buf_t *handle, uint64_t offset, arc_buf_t *buf,
1317 dmu_tx_t *tx)
1319 dmu_buf_impl_t *dbuf = (dmu_buf_impl_t *)handle;
1320 dnode_t *dn;
1321 dmu_buf_impl_t *db;
1322 uint32_t blksz = (uint32_t)arc_buf_size(buf);
1323 uint64_t blkid;
1325 DB_DNODE_ENTER(dbuf);
1326 dn = DB_DNODE(dbuf);
1327 rw_enter(&dn->dn_struct_rwlock, RW_READER);
1328 blkid = dbuf_whichblock(dn, offset);
1329 VERIFY((db = dbuf_hold(dn, blkid, FTAG)) != NULL);
1330 rw_exit(&dn->dn_struct_rwlock);
1331 DB_DNODE_EXIT(dbuf);
1334 * We can only assign if the offset is aligned, the arc buf is the
1335 * same size as the dbuf, and the dbuf is not metadata. It
1336 * can't be metadata because the loaned arc buf comes from the
1337 * user-data kmem arena.
1339 if (offset == db->db.db_offset && blksz == db->db.db_size &&
1340 DBUF_GET_BUFC_TYPE(db) == ARC_BUFC_DATA) {
1341 dbuf_assign_arcbuf(db, buf, tx);
1342 dbuf_rele(db, FTAG);
1343 } else {
1344 objset_t *os;
1345 uint64_t object;
1347 DB_DNODE_ENTER(dbuf);
1348 dn = DB_DNODE(dbuf);
1349 os = dn->dn_objset;
1350 object = dn->dn_object;
1351 DB_DNODE_EXIT(dbuf);
1353 dbuf_rele(db, FTAG);
1354 dmu_write(os, object, offset, blksz, buf->b_data, tx);
1355 dmu_return_arcbuf(buf);
1356 XUIOSTAT_BUMP(xuiostat_wbuf_copied);
1360 typedef struct {
1361 dbuf_dirty_record_t *dsa_dr;
1362 dmu_sync_cb_t *dsa_done;
1363 zgd_t *dsa_zgd;
1364 dmu_tx_t *dsa_tx;
1365 } dmu_sync_arg_t;
1367 /* ARGSUSED */
1368 static void
1369 dmu_sync_ready(zio_t *zio, arc_buf_t *buf, void *varg)
1371 dmu_sync_arg_t *dsa = varg;
1372 dmu_buf_t *db = dsa->dsa_zgd->zgd_db;
1373 blkptr_t *bp = zio->io_bp;
1375 if (zio->io_error == 0) {
1376 if (BP_IS_HOLE(bp)) {
1378 * A block of zeros may compress to a hole, but the
1379 * block size still needs to be known for replay.
1381 BP_SET_LSIZE(bp, db->db_size);
1382 } else if (!BP_IS_EMBEDDED(bp)) {
1383 ASSERT(BP_GET_LEVEL(bp) == 0);
1384 bp->blk_fill = 1;
1389 static void
1390 dmu_sync_late_arrival_ready(zio_t *zio)
1392 dmu_sync_ready(zio, NULL, zio->io_private);
1395 /* ARGSUSED */
1396 static void
1397 dmu_sync_done(zio_t *zio, arc_buf_t *buf, void *varg)
1399 dmu_sync_arg_t *dsa = varg;
1400 dbuf_dirty_record_t *dr = dsa->dsa_dr;
1401 dmu_buf_impl_t *db = dr->dr_dbuf;
1403 mutex_enter(&db->db_mtx);
1404 ASSERT(dr->dt.dl.dr_override_state == DR_IN_DMU_SYNC);
1405 if (zio->io_error == 0) {
1406 dr->dt.dl.dr_nopwrite = !!(zio->io_flags & ZIO_FLAG_NOPWRITE);
1407 if (dr->dt.dl.dr_nopwrite) {
1408 blkptr_t *bp = zio->io_bp;
1409 blkptr_t *bp_orig = &zio->io_bp_orig;
1410 uint8_t chksum = BP_GET_CHECKSUM(bp_orig);
1412 ASSERT(BP_EQUAL(bp, bp_orig));
1413 ASSERT(zio->io_prop.zp_compress != ZIO_COMPRESS_OFF);
1414 ASSERT(zio_checksum_table[chksum].ci_dedup);
1416 dr->dt.dl.dr_overridden_by = *zio->io_bp;
1417 dr->dt.dl.dr_override_state = DR_OVERRIDDEN;
1418 dr->dt.dl.dr_copies = zio->io_prop.zp_copies;
1419 if (BP_IS_HOLE(&dr->dt.dl.dr_overridden_by))
1420 BP_ZERO(&dr->dt.dl.dr_overridden_by);
1421 } else {
1422 dr->dt.dl.dr_override_state = DR_NOT_OVERRIDDEN;
1424 cv_broadcast(&db->db_changed);
1425 mutex_exit(&db->db_mtx);
1427 dsa->dsa_done(dsa->dsa_zgd, zio->io_error);
1429 kmem_free(dsa, sizeof (*dsa));
1432 static void
1433 dmu_sync_late_arrival_done(zio_t *zio)
1435 blkptr_t *bp = zio->io_bp;
1436 dmu_sync_arg_t *dsa = zio->io_private;
1437 blkptr_t *bp_orig = &zio->io_bp_orig;
1439 if (zio->io_error == 0 && !BP_IS_HOLE(bp)) {
1441 * If we didn't allocate a new block (i.e. ZIO_FLAG_NOPWRITE)
1442 * then there is nothing to do here. Otherwise, free the
1443 * newly allocated block in this txg.
1445 if (zio->io_flags & ZIO_FLAG_NOPWRITE) {
1446 ASSERT(BP_EQUAL(bp, bp_orig));
1447 } else {
1448 ASSERT(BP_IS_HOLE(bp_orig) || !BP_EQUAL(bp, bp_orig));
1449 ASSERT(zio->io_bp->blk_birth == zio->io_txg);
1450 ASSERT(zio->io_txg > spa_syncing_txg(zio->io_spa));
1451 zio_free(zio->io_spa, zio->io_txg, zio->io_bp);
1455 dmu_tx_commit(dsa->dsa_tx);
1457 dsa->dsa_done(dsa->dsa_zgd, zio->io_error);
1459 kmem_free(dsa, sizeof (*dsa));
1462 static int
1463 dmu_sync_late_arrival(zio_t *pio, objset_t *os, dmu_sync_cb_t *done, zgd_t *zgd,
1464 zio_prop_t *zp, zbookmark_phys_t *zb)
1466 dmu_sync_arg_t *dsa;
1467 dmu_tx_t *tx;
1469 tx = dmu_tx_create(os);
1470 dmu_tx_hold_space(tx, zgd->zgd_db->db_size);
1471 if (dmu_tx_assign(tx, TXG_WAIT) != 0) {
1472 dmu_tx_abort(tx);
1473 /* Make zl_get_data do txg_waited_synced() */
1474 return (SET_ERROR(EIO));
1477 dsa = kmem_alloc(sizeof (dmu_sync_arg_t), KM_SLEEP);
1478 dsa->dsa_dr = NULL;
1479 dsa->dsa_done = done;
1480 dsa->dsa_zgd = zgd;
1481 dsa->dsa_tx = tx;
1483 zio_nowait(zio_write(pio, os->os_spa, dmu_tx_get_txg(tx), zgd->zgd_bp,
1484 zgd->zgd_db->db_data, zgd->zgd_db->db_size, zp,
1485 dmu_sync_late_arrival_ready, NULL, dmu_sync_late_arrival_done, dsa,
1486 ZIO_PRIORITY_SYNC_WRITE, ZIO_FLAG_CANFAIL, zb));
1488 return (0);
1492 * Intent log support: sync the block associated with db to disk.
1493 * N.B. and XXX: the caller is responsible for making sure that the
1494 * data isn't changing while dmu_sync() is writing it.
1496 * Return values:
1498 * EEXIST: this txg has already been synced, so there's nothing to do.
1499 * The caller should not log the write.
1501 * ENOENT: the block was dbuf_free_range()'d, so there's nothing to do.
1502 * The caller should not log the write.
1504 * EALREADY: this block is already in the process of being synced.
1505 * The caller should track its progress (somehow).
1507 * EIO: could not do the I/O.
1508 * The caller should do a txg_wait_synced().
1510 * 0: the I/O has been initiated.
1511 * The caller should log this blkptr in the done callback.
1512 * It is possible that the I/O will fail, in which case
1513 * the error will be reported to the done callback and
1514 * propagated to pio from zio_done().
1517 dmu_sync(zio_t *pio, uint64_t txg, dmu_sync_cb_t *done, zgd_t *zgd)
1519 blkptr_t *bp = zgd->zgd_bp;
1520 dmu_buf_impl_t *db = (dmu_buf_impl_t *)zgd->zgd_db;
1521 objset_t *os = db->db_objset;
1522 dsl_dataset_t *ds = os->os_dsl_dataset;
1523 dbuf_dirty_record_t *dr;
1524 dmu_sync_arg_t *dsa;
1525 zbookmark_phys_t zb;
1526 zio_prop_t zp;
1527 dnode_t *dn;
1529 ASSERT(pio != NULL);
1530 ASSERT(txg != 0);
1532 SET_BOOKMARK(&zb, ds->ds_object,
1533 db->db.db_object, db->db_level, db->db_blkid);
1535 DB_DNODE_ENTER(db);
1536 dn = DB_DNODE(db);
1537 dmu_write_policy(os, dn, db->db_level, WP_DMU_SYNC, &zp);
1538 DB_DNODE_EXIT(db);
1541 * If we're frozen (running ziltest), we always need to generate a bp.
1543 if (txg > spa_freeze_txg(os->os_spa))
1544 return (dmu_sync_late_arrival(pio, os, done, zgd, &zp, &zb));
1547 * Grabbing db_mtx now provides a barrier between dbuf_sync_leaf()
1548 * and us. If we determine that this txg is not yet syncing,
1549 * but it begins to sync a moment later, that's OK because the
1550 * sync thread will block in dbuf_sync_leaf() until we drop db_mtx.
1552 mutex_enter(&db->db_mtx);
1554 if (txg <= spa_last_synced_txg(os->os_spa)) {
1556 * This txg has already synced. There's nothing to do.
1558 mutex_exit(&db->db_mtx);
1559 return (SET_ERROR(EEXIST));
1562 if (txg <= spa_syncing_txg(os->os_spa)) {
1564 * This txg is currently syncing, so we can't mess with
1565 * the dirty record anymore; just write a new log block.
1567 mutex_exit(&db->db_mtx);
1568 return (dmu_sync_late_arrival(pio, os, done, zgd, &zp, &zb));
1571 dr = db->db_last_dirty;
1572 while (dr && dr->dr_txg != txg)
1573 dr = dr->dr_next;
1575 if (dr == NULL) {
1577 * There's no dr for this dbuf, so it must have been freed.
1578 * There's no need to log writes to freed blocks, so we're done.
1580 mutex_exit(&db->db_mtx);
1581 return (SET_ERROR(ENOENT));
1584 ASSERT(dr->dr_next == NULL || dr->dr_next->dr_txg < txg);
1587 * Assume the on-disk data is X, the current syncing data is Y,
1588 * and the current in-memory data is Z (currently in dmu_sync).
1589 * X and Z are identical but Y is has been modified. Normally,
1590 * when X and Z are the same we will perform a nopwrite but if Y
1591 * is different we must disable nopwrite since the resulting write
1592 * of Y to disk can free the block containing X. If we allowed a
1593 * nopwrite to occur the block pointing to Z would reference a freed
1594 * block. Since this is a rare case we simplify this by disabling
1595 * nopwrite if the current dmu_sync-ing dbuf has been modified in
1596 * a previous transaction.
1598 if (dr->dr_next)
1599 zp.zp_nopwrite = B_FALSE;
1601 ASSERT(dr->dr_txg == txg);
1602 if (dr->dt.dl.dr_override_state == DR_IN_DMU_SYNC ||
1603 dr->dt.dl.dr_override_state == DR_OVERRIDDEN) {
1605 * We have already issued a sync write for this buffer,
1606 * or this buffer has already been synced. It could not
1607 * have been dirtied since, or we would have cleared the state.
1609 mutex_exit(&db->db_mtx);
1610 return (SET_ERROR(EALREADY));
1613 ASSERT(dr->dt.dl.dr_override_state == DR_NOT_OVERRIDDEN);
1614 dr->dt.dl.dr_override_state = DR_IN_DMU_SYNC;
1615 mutex_exit(&db->db_mtx);
1617 dsa = kmem_alloc(sizeof (dmu_sync_arg_t), KM_SLEEP);
1618 dsa->dsa_dr = dr;
1619 dsa->dsa_done = done;
1620 dsa->dsa_zgd = zgd;
1621 dsa->dsa_tx = NULL;
1623 zio_nowait(arc_write(pio, os->os_spa, txg,
1624 bp, dr->dt.dl.dr_data, DBUF_IS_L2CACHEABLE(db),
1625 DBUF_IS_L2COMPRESSIBLE(db), &zp, dmu_sync_ready,
1626 NULL, dmu_sync_done, dsa, ZIO_PRIORITY_SYNC_WRITE,
1627 ZIO_FLAG_CANFAIL, &zb));
1629 return (0);
1633 dmu_object_set_blocksize(objset_t *os, uint64_t object, uint64_t size, int ibs,
1634 dmu_tx_t *tx)
1636 dnode_t *dn;
1637 int err;
1639 err = dnode_hold(os, object, FTAG, &dn);
1640 if (err)
1641 return (err);
1642 err = dnode_set_blksz(dn, size, ibs, tx);
1643 dnode_rele(dn, FTAG);
1644 return (err);
1647 void
1648 dmu_object_set_checksum(objset_t *os, uint64_t object, uint8_t checksum,
1649 dmu_tx_t *tx)
1651 dnode_t *dn;
1654 * Send streams include each object's checksum function. This
1655 * check ensures that the receiving system can understand the
1656 * checksum function transmitted.
1658 ASSERT3U(checksum, <, ZIO_CHECKSUM_LEGACY_FUNCTIONS);
1660 VERIFY0(dnode_hold(os, object, FTAG, &dn));
1661 ASSERT3U(checksum, <, ZIO_CHECKSUM_FUNCTIONS);
1662 dn->dn_checksum = checksum;
1663 dnode_setdirty(dn, tx);
1664 dnode_rele(dn, FTAG);
1667 void
1668 dmu_object_set_compress(objset_t *os, uint64_t object, uint8_t compress,
1669 dmu_tx_t *tx)
1671 dnode_t *dn;
1674 * Send streams include each object's compression function. This
1675 * check ensures that the receiving system can understand the
1676 * compression function transmitted.
1678 ASSERT3U(compress, <, ZIO_COMPRESS_LEGACY_FUNCTIONS);
1680 VERIFY0(dnode_hold(os, object, FTAG, &dn));
1681 dn->dn_compress = compress;
1682 dnode_setdirty(dn, tx);
1683 dnode_rele(dn, FTAG);
1686 int zfs_mdcomp_disable = 0;
1689 * When the "redundant_metadata" property is set to "most", only indirect
1690 * blocks of this level and higher will have an additional ditto block.
1692 int zfs_redundant_metadata_most_ditto_level = 2;
1694 void
1695 dmu_write_policy(objset_t *os, dnode_t *dn, int level, int wp, zio_prop_t *zp)
1697 dmu_object_type_t type = dn ? dn->dn_type : DMU_OT_OBJSET;
1698 boolean_t ismd = (level > 0 || DMU_OT_IS_METADATA(type) ||
1699 (wp & WP_SPILL));
1700 enum zio_checksum checksum = os->os_checksum;
1701 enum zio_compress compress = os->os_compress;
1702 enum zio_checksum dedup_checksum = os->os_dedup_checksum;
1703 boolean_t dedup = B_FALSE;
1704 boolean_t nopwrite = B_FALSE;
1705 boolean_t dedup_verify = os->os_dedup_verify;
1706 int copies = os->os_copies;
1709 * We maintain different write policies for each of the following
1710 * types of data:
1711 * 1. metadata
1712 * 2. preallocated blocks (i.e. level-0 blocks of a dump device)
1713 * 3. all other level 0 blocks
1715 if (ismd) {
1716 if (zfs_mdcomp_disable) {
1717 compress = ZIO_COMPRESS_EMPTY;
1718 } else {
1720 * XXX -- we should design a compression algorithm
1721 * that specializes in arrays of bps.
1723 compress = zio_compress_select(os->os_spa,
1724 ZIO_COMPRESS_ON, ZIO_COMPRESS_ON);
1728 * Metadata always gets checksummed. If the data
1729 * checksum is multi-bit correctable, and it's not a
1730 * ZBT-style checksum, then it's suitable for metadata
1731 * as well. Otherwise, the metadata checksum defaults
1732 * to fletcher4.
1734 if (zio_checksum_table[checksum].ci_correctable < 1 ||
1735 zio_checksum_table[checksum].ci_eck)
1736 checksum = ZIO_CHECKSUM_FLETCHER_4;
1738 if (os->os_redundant_metadata == ZFS_REDUNDANT_METADATA_ALL ||
1739 (os->os_redundant_metadata ==
1740 ZFS_REDUNDANT_METADATA_MOST &&
1741 (level >= zfs_redundant_metadata_most_ditto_level ||
1742 DMU_OT_IS_METADATA(type) || (wp & WP_SPILL))))
1743 copies++;
1744 } else if (wp & WP_NOFILL) {
1745 ASSERT(level == 0);
1748 * If we're writing preallocated blocks, we aren't actually
1749 * writing them so don't set any policy properties. These
1750 * blocks are currently only used by an external subsystem
1751 * outside of zfs (i.e. dump) and not written by the zio
1752 * pipeline.
1754 compress = ZIO_COMPRESS_OFF;
1755 checksum = ZIO_CHECKSUM_NOPARITY;
1756 } else {
1757 compress = zio_compress_select(os->os_spa, dn->dn_compress,
1758 compress);
1760 checksum = (dedup_checksum == ZIO_CHECKSUM_OFF) ?
1761 zio_checksum_select(dn->dn_checksum, checksum) :
1762 dedup_checksum;
1765 * Determine dedup setting. If we are in dmu_sync(),
1766 * we won't actually dedup now because that's all
1767 * done in syncing context; but we do want to use the
1768 * dedup checkum. If the checksum is not strong
1769 * enough to ensure unique signatures, force
1770 * dedup_verify.
1772 if (dedup_checksum != ZIO_CHECKSUM_OFF) {
1773 dedup = (wp & WP_DMU_SYNC) ? B_FALSE : B_TRUE;
1774 if (!zio_checksum_table[checksum].ci_dedup)
1775 dedup_verify = B_TRUE;
1779 * Enable nopwrite if we have a cryptographically secure
1780 * checksum that has no known collisions (i.e. SHA-256)
1781 * and compression is enabled. We don't enable nopwrite if
1782 * dedup is enabled as the two features are mutually exclusive.
1784 nopwrite = (!dedup && zio_checksum_table[checksum].ci_dedup &&
1785 compress != ZIO_COMPRESS_OFF && zfs_nopwrite_enabled);
1788 zp->zp_checksum = checksum;
1789 zp->zp_compress = compress;
1790 zp->zp_type = (wp & WP_SPILL) ? dn->dn_bonustype : type;
1791 zp->zp_level = level;
1792 zp->zp_copies = MIN(copies, spa_max_replication(os->os_spa));
1793 zp->zp_dedup = dedup;
1794 zp->zp_dedup_verify = dedup && dedup_verify;
1795 zp->zp_nopwrite = nopwrite;
1799 dmu_offset_next(objset_t *os, uint64_t object, boolean_t hole, uint64_t *off)
1801 dnode_t *dn;
1802 int i, err;
1804 err = dnode_hold(os, object, FTAG, &dn);
1805 if (err)
1806 return (err);
1808 * Sync any current changes before
1809 * we go trundling through the block pointers.
1811 for (i = 0; i < TXG_SIZE; i++) {
1812 if (list_link_active(&dn->dn_dirty_link[i]))
1813 break;
1815 if (i != TXG_SIZE) {
1816 dnode_rele(dn, FTAG);
1817 txg_wait_synced(dmu_objset_pool(os), 0);
1818 err = dnode_hold(os, object, FTAG, &dn);
1819 if (err)
1820 return (err);
1823 err = dnode_next_offset(dn, (hole ? DNODE_FIND_HOLE : 0), off, 1, 1, 0);
1824 dnode_rele(dn, FTAG);
1826 return (err);
1829 void
1830 dmu_object_info_from_dnode(dnode_t *dn, dmu_object_info_t *doi)
1832 dnode_phys_t *dnp;
1834 rw_enter(&dn->dn_struct_rwlock, RW_READER);
1835 mutex_enter(&dn->dn_mtx);
1837 dnp = dn->dn_phys;
1839 doi->doi_data_block_size = dn->dn_datablksz;
1840 doi->doi_metadata_block_size = dn->dn_indblkshift ?
1841 1ULL << dn->dn_indblkshift : 0;
1842 doi->doi_type = dn->dn_type;
1843 doi->doi_bonus_type = dn->dn_bonustype;
1844 doi->doi_bonus_size = dn->dn_bonuslen;
1845 doi->doi_indirection = dn->dn_nlevels;
1846 doi->doi_checksum = dn->dn_checksum;
1847 doi->doi_compress = dn->dn_compress;
1848 doi->doi_nblkptr = dn->dn_nblkptr;
1849 doi->doi_physical_blocks_512 = (DN_USED_BYTES(dnp) + 256) >> 9;
1850 doi->doi_max_offset = (dn->dn_maxblkid + 1) * dn->dn_datablksz;
1851 doi->doi_fill_count = 0;
1852 for (int i = 0; i < dnp->dn_nblkptr; i++)
1853 doi->doi_fill_count += BP_GET_FILL(&dnp->dn_blkptr[i]);
1855 mutex_exit(&dn->dn_mtx);
1856 rw_exit(&dn->dn_struct_rwlock);
1860 * Get information on a DMU object.
1861 * If doi is NULL, just indicates whether the object exists.
1864 dmu_object_info(objset_t *os, uint64_t object, dmu_object_info_t *doi)
1866 dnode_t *dn;
1867 int err = dnode_hold(os, object, FTAG, &dn);
1869 if (err)
1870 return (err);
1872 if (doi != NULL)
1873 dmu_object_info_from_dnode(dn, doi);
1875 dnode_rele(dn, FTAG);
1876 return (0);
1880 * As above, but faster; can be used when you have a held dbuf in hand.
1882 void
1883 dmu_object_info_from_db(dmu_buf_t *db_fake, dmu_object_info_t *doi)
1885 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
1887 DB_DNODE_ENTER(db);
1888 dmu_object_info_from_dnode(DB_DNODE(db), doi);
1889 DB_DNODE_EXIT(db);
1893 * Faster still when you only care about the size.
1894 * This is specifically optimized for zfs_getattr().
1896 void
1897 dmu_object_size_from_db(dmu_buf_t *db_fake, uint32_t *blksize,
1898 u_longlong_t *nblk512)
1900 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
1901 dnode_t *dn;
1903 DB_DNODE_ENTER(db);
1904 dn = DB_DNODE(db);
1906 *blksize = dn->dn_datablksz;
1907 /* add 1 for dnode space */
1908 *nblk512 = ((DN_USED_BYTES(dn->dn_phys) + SPA_MINBLOCKSIZE/2) >>
1909 SPA_MINBLOCKSHIFT) + 1;
1910 DB_DNODE_EXIT(db);
1913 void
1914 byteswap_uint64_array(void *vbuf, size_t size)
1916 uint64_t *buf = vbuf;
1917 size_t count = size >> 3;
1918 int i;
1920 ASSERT((size & 7) == 0);
1922 for (i = 0; i < count; i++)
1923 buf[i] = BSWAP_64(buf[i]);
1926 void
1927 byteswap_uint32_array(void *vbuf, size_t size)
1929 uint32_t *buf = vbuf;
1930 size_t count = size >> 2;
1931 int i;
1933 ASSERT((size & 3) == 0);
1935 for (i = 0; i < count; i++)
1936 buf[i] = BSWAP_32(buf[i]);
1939 void
1940 byteswap_uint16_array(void *vbuf, size_t size)
1942 uint16_t *buf = vbuf;
1943 size_t count = size >> 1;
1944 int i;
1946 ASSERT((size & 1) == 0);
1948 for (i = 0; i < count; i++)
1949 buf[i] = BSWAP_16(buf[i]);
1952 /* ARGSUSED */
1953 void
1954 byteswap_uint8_array(void *vbuf, size_t size)
1958 void
1959 dmu_init(void)
1961 zfs_dbgmsg_init();
1962 sa_cache_init();
1963 xuio_stat_init();
1964 dmu_objset_init();
1965 dnode_init();
1966 dbuf_init();
1967 zfetch_init();
1968 l2arc_init();
1969 arc_init();
1972 void
1973 dmu_fini(void)
1975 arc_fini(); /* arc depends on l2arc, so arc must go first */
1976 l2arc_fini();
1977 zfetch_fini();
1978 dbuf_fini();
1979 dnode_fini();
1980 dmu_objset_fini();
1981 xuio_stat_fini();
1982 sa_cache_fini();
1983 zfs_dbgmsg_fini();