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]
22 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
23 * Copyright (c) 2011, 2014 by Delphix. All rights reserved.
24 * Copyright (c) 2013 by Saso Kiselkov. All rights reserved.
25 * Copyright (c) 2014, Nexenta Systems, Inc. All rights reserved.
29 #include <sys/dmu_impl.h>
30 #include <sys/dmu_tx.h>
32 #include <sys/dnode.h>
33 #include <sys/zfs_context.h>
34 #include <sys/dmu_objset.h>
35 #include <sys/dmu_traverse.h>
36 #include <sys/dsl_dataset.h>
37 #include <sys/dsl_dir.h>
38 #include <sys/dsl_pool.h>
39 #include <sys/dsl_synctask.h>
40 #include <sys/dsl_prop.h>
41 #include <sys/dmu_zfetch.h>
42 #include <sys/zfs_ioctl.h>
44 #include <sys/zio_checksum.h>
45 #include <sys/zio_compress.h>
47 #include <sys/zfeature.h>
49 #include <sys/vmsystm.h>
50 #include <sys/zfs_znode.h>
54 * Enable/disable nopwrite feature.
56 int zfs_nopwrite_enabled = 1;
58 const dmu_object_type_info_t dmu_ot[DMU_OT_NUMTYPES] = {
59 { DMU_BSWAP_UINT8, TRUE, "unallocated" },
60 { DMU_BSWAP_ZAP, TRUE, "object directory" },
61 { DMU_BSWAP_UINT64, TRUE, "object array" },
62 { DMU_BSWAP_UINT8, TRUE, "packed nvlist" },
63 { DMU_BSWAP_UINT64, TRUE, "packed nvlist size" },
64 { DMU_BSWAP_UINT64, TRUE, "bpobj" },
65 { DMU_BSWAP_UINT64, TRUE, "bpobj header" },
66 { DMU_BSWAP_UINT64, TRUE, "SPA space map header" },
67 { DMU_BSWAP_UINT64, TRUE, "SPA space map" },
68 { DMU_BSWAP_UINT64, TRUE, "ZIL intent log" },
69 { DMU_BSWAP_DNODE, TRUE, "DMU dnode" },
70 { DMU_BSWAP_OBJSET, TRUE, "DMU objset" },
71 { DMU_BSWAP_UINT64, TRUE, "DSL directory" },
72 { DMU_BSWAP_ZAP, TRUE, "DSL directory child map"},
73 { DMU_BSWAP_ZAP, TRUE, "DSL dataset snap map" },
74 { DMU_BSWAP_ZAP, TRUE, "DSL props" },
75 { DMU_BSWAP_UINT64, TRUE, "DSL dataset" },
76 { DMU_BSWAP_ZNODE, TRUE, "ZFS znode" },
77 { DMU_BSWAP_OLDACL, TRUE, "ZFS V0 ACL" },
78 { DMU_BSWAP_UINT8, FALSE, "ZFS plain file" },
79 { DMU_BSWAP_ZAP, TRUE, "ZFS directory" },
80 { DMU_BSWAP_ZAP, TRUE, "ZFS master node" },
81 { DMU_BSWAP_ZAP, TRUE, "ZFS delete queue" },
82 { DMU_BSWAP_UINT8, FALSE, "zvol object" },
83 { DMU_BSWAP_ZAP, TRUE, "zvol prop" },
84 { DMU_BSWAP_UINT8, FALSE, "other uint8[]" },
85 { DMU_BSWAP_UINT64, FALSE, "other uint64[]" },
86 { DMU_BSWAP_ZAP, TRUE, "other ZAP" },
87 { DMU_BSWAP_ZAP, TRUE, "persistent error log" },
88 { DMU_BSWAP_UINT8, TRUE, "SPA history" },
89 { DMU_BSWAP_UINT64, TRUE, "SPA history offsets" },
90 { DMU_BSWAP_ZAP, TRUE, "Pool properties" },
91 { DMU_BSWAP_ZAP, TRUE, "DSL permissions" },
92 { DMU_BSWAP_ACL, TRUE, "ZFS ACL" },
93 { DMU_BSWAP_UINT8, TRUE, "ZFS SYSACL" },
94 { DMU_BSWAP_UINT8, TRUE, "FUID table" },
95 { DMU_BSWAP_UINT64, TRUE, "FUID table size" },
96 { DMU_BSWAP_ZAP, TRUE, "DSL dataset next clones"},
97 { DMU_BSWAP_ZAP, TRUE, "scan work queue" },
98 { DMU_BSWAP_ZAP, TRUE, "ZFS user/group used" },
99 { DMU_BSWAP_ZAP, TRUE, "ZFS user/group quota" },
100 { DMU_BSWAP_ZAP, TRUE, "snapshot refcount tags"},
101 { DMU_BSWAP_ZAP, TRUE, "DDT ZAP algorithm" },
102 { DMU_BSWAP_ZAP, TRUE, "DDT statistics" },
103 { DMU_BSWAP_UINT8, TRUE, "System attributes" },
104 { DMU_BSWAP_ZAP, TRUE, "SA master node" },
105 { DMU_BSWAP_ZAP, TRUE, "SA attr registration" },
106 { DMU_BSWAP_ZAP, TRUE, "SA attr layouts" },
107 { DMU_BSWAP_ZAP, TRUE, "scan translations" },
108 { DMU_BSWAP_UINT8, FALSE, "deduplicated block" },
109 { DMU_BSWAP_ZAP, TRUE, "DSL deadlist map" },
110 { DMU_BSWAP_UINT64, TRUE, "DSL deadlist map hdr" },
111 { DMU_BSWAP_ZAP, TRUE, "DSL dir clones" },
112 { DMU_BSWAP_UINT64, TRUE, "bpobj subobj" }
115 const dmu_object_byteswap_info_t dmu_ot_byteswap[DMU_BSWAP_NUMFUNCS] = {
116 { byteswap_uint8_array, "uint8" },
117 { byteswap_uint16_array, "uint16" },
118 { byteswap_uint32_array, "uint32" },
119 { byteswap_uint64_array, "uint64" },
120 { zap_byteswap, "zap" },
121 { dnode_buf_byteswap, "dnode" },
122 { dmu_objset_byteswap, "objset" },
123 { zfs_znode_byteswap, "znode" },
124 { zfs_oldacl_byteswap, "oldacl" },
125 { zfs_acl_byteswap, "acl" }
129 dmu_buf_hold_noread(objset_t *os, uint64_t object, uint64_t offset,
130 void *tag, dmu_buf_t **dbp)
137 err = dnode_hold(os, object, FTAG, &dn);
140 blkid = dbuf_whichblock(dn, offset);
141 rw_enter(&dn->dn_struct_rwlock, RW_READER);
142 db = dbuf_hold(dn, blkid, tag);
143 rw_exit(&dn->dn_struct_rwlock);
144 dnode_rele(dn, FTAG);
148 return (SET_ERROR(EIO));
156 dmu_buf_hold(objset_t *os, uint64_t object, uint64_t offset,
157 void *tag, dmu_buf_t **dbp, int flags)
160 int db_flags = DB_RF_CANFAIL;
162 if (flags & DMU_READ_NO_PREFETCH)
163 db_flags |= DB_RF_NOPREFETCH;
165 err = dmu_buf_hold_noread(os, object, offset, tag, dbp);
167 dmu_buf_impl_t *db = (dmu_buf_impl_t *)(*dbp);
168 err = dbuf_read(db, NULL, db_flags);
181 return (DN_MAX_BONUSLEN);
185 dmu_set_bonus(dmu_buf_t *db_fake, int newsize, dmu_tx_t *tx)
187 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
194 if (dn->dn_bonus != db) {
195 error = SET_ERROR(EINVAL);
196 } else if (newsize < 0 || newsize > db_fake->db_size) {
197 error = SET_ERROR(EINVAL);
199 dnode_setbonuslen(dn, newsize, tx);
208 dmu_set_bonustype(dmu_buf_t *db_fake, dmu_object_type_t type, dmu_tx_t *tx)
210 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
217 if (!DMU_OT_IS_VALID(type)) {
218 error = SET_ERROR(EINVAL);
219 } else if (dn->dn_bonus != db) {
220 error = SET_ERROR(EINVAL);
222 dnode_setbonus_type(dn, type, tx);
231 dmu_get_bonustype(dmu_buf_t *db_fake)
233 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
235 dmu_object_type_t type;
239 type = dn->dn_bonustype;
246 dmu_rm_spill(objset_t *os, uint64_t object, dmu_tx_t *tx)
251 error = dnode_hold(os, object, FTAG, &dn);
252 dbuf_rm_spill(dn, tx);
253 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
254 dnode_rm_spill(dn, tx);
255 rw_exit(&dn->dn_struct_rwlock);
256 dnode_rele(dn, FTAG);
261 * returns ENOENT, EIO, or 0.
264 dmu_bonus_hold(objset_t *os, uint64_t object, void *tag, dmu_buf_t **dbp)
270 error = dnode_hold(os, object, FTAG, &dn);
274 rw_enter(&dn->dn_struct_rwlock, RW_READER);
275 if (dn->dn_bonus == NULL) {
276 rw_exit(&dn->dn_struct_rwlock);
277 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
278 if (dn->dn_bonus == NULL)
279 dbuf_create_bonus(dn);
283 /* as long as the bonus buf is held, the dnode will be held */
284 if (refcount_add(&db->db_holds, tag) == 1) {
285 VERIFY(dnode_add_ref(dn, db));
286 atomic_inc_32(&dn->dn_dbufs_count);
290 * Wait to drop dn_struct_rwlock until after adding the bonus dbuf's
291 * hold and incrementing the dbuf count to ensure that dnode_move() sees
292 * a dnode hold for every dbuf.
294 rw_exit(&dn->dn_struct_rwlock);
296 dnode_rele(dn, FTAG);
298 VERIFY(0 == dbuf_read(db, NULL, DB_RF_MUST_SUCCEED | DB_RF_NOPREFETCH));
305 * returns ENOENT, EIO, or 0.
307 * This interface will allocate a blank spill dbuf when a spill blk
308 * doesn't already exist on the dnode.
310 * if you only want to find an already existing spill db, then
311 * dmu_spill_hold_existing() should be used.
314 dmu_spill_hold_by_dnode(dnode_t *dn, uint32_t flags, void *tag, dmu_buf_t **dbp)
316 dmu_buf_impl_t *db = NULL;
319 if ((flags & DB_RF_HAVESTRUCT) == 0)
320 rw_enter(&dn->dn_struct_rwlock, RW_READER);
322 db = dbuf_hold(dn, DMU_SPILL_BLKID, tag);
324 if ((flags & DB_RF_HAVESTRUCT) == 0)
325 rw_exit(&dn->dn_struct_rwlock);
328 err = dbuf_read(db, NULL, flags);
337 dmu_spill_hold_existing(dmu_buf_t *bonus, void *tag, dmu_buf_t **dbp)
339 dmu_buf_impl_t *db = (dmu_buf_impl_t *)bonus;
346 if (spa_version(dn->dn_objset->os_spa) < SPA_VERSION_SA) {
347 err = SET_ERROR(EINVAL);
349 rw_enter(&dn->dn_struct_rwlock, RW_READER);
351 if (!dn->dn_have_spill) {
352 err = SET_ERROR(ENOENT);
354 err = dmu_spill_hold_by_dnode(dn,
355 DB_RF_HAVESTRUCT | DB_RF_CANFAIL, tag, dbp);
358 rw_exit(&dn->dn_struct_rwlock);
366 dmu_spill_hold_by_bonus(dmu_buf_t *bonus, void *tag, dmu_buf_t **dbp)
368 dmu_buf_impl_t *db = (dmu_buf_impl_t *)bonus;
374 err = dmu_spill_hold_by_dnode(dn, DB_RF_CANFAIL, tag, dbp);
381 * Note: longer-term, we should modify all of the dmu_buf_*() interfaces
382 * to take a held dnode rather than <os, object> -- the lookup is wasteful,
383 * and can induce severe lock contention when writing to several files
384 * whose dnodes are in the same block.
387 dmu_buf_hold_array_by_dnode(dnode_t *dn, uint64_t offset, uint64_t length,
388 int read, void *tag, int *numbufsp, dmu_buf_t ***dbpp, uint32_t flags)
391 uint64_t blkid, nblks, i;
396 ASSERT(length <= DMU_MAX_ACCESS);
398 dbuf_flags = DB_RF_CANFAIL | DB_RF_NEVERWAIT | DB_RF_HAVESTRUCT;
399 if (flags & DMU_READ_NO_PREFETCH || length > zfetch_array_rd_sz)
400 dbuf_flags |= DB_RF_NOPREFETCH;
402 rw_enter(&dn->dn_struct_rwlock, RW_READER);
403 if (dn->dn_datablkshift) {
404 int blkshift = dn->dn_datablkshift;
405 nblks = (P2ROUNDUP(offset+length, 1ULL<<blkshift) -
406 P2ALIGN(offset, 1ULL<<blkshift)) >> blkshift;
408 if (offset + length > dn->dn_datablksz) {
409 zfs_panic_recover("zfs: accessing past end of object "
410 "%llx/%llx (size=%u access=%llu+%llu)",
411 (longlong_t)dn->dn_objset->
412 os_dsl_dataset->ds_object,
413 (longlong_t)dn->dn_object, dn->dn_datablksz,
414 (longlong_t)offset, (longlong_t)length);
415 rw_exit(&dn->dn_struct_rwlock);
416 return (SET_ERROR(EIO));
420 dbp = kmem_zalloc(sizeof (dmu_buf_t *) * nblks, KM_SLEEP);
422 zio = zio_root(dn->dn_objset->os_spa, NULL, NULL, ZIO_FLAG_CANFAIL);
423 blkid = dbuf_whichblock(dn, offset);
424 for (i = 0; i < nblks; i++) {
425 dmu_buf_impl_t *db = dbuf_hold(dn, blkid+i, tag);
427 rw_exit(&dn->dn_struct_rwlock);
428 dmu_buf_rele_array(dbp, nblks, tag);
430 return (SET_ERROR(EIO));
432 /* initiate async i/o */
434 (void) dbuf_read(db, zio, dbuf_flags);
438 rw_exit(&dn->dn_struct_rwlock);
440 /* wait for async i/o */
443 dmu_buf_rele_array(dbp, nblks, tag);
447 /* wait for other io to complete */
449 for (i = 0; i < nblks; i++) {
450 dmu_buf_impl_t *db = (dmu_buf_impl_t *)dbp[i];
451 mutex_enter(&db->db_mtx);
452 while (db->db_state == DB_READ ||
453 db->db_state == DB_FILL)
454 cv_wait(&db->db_changed, &db->db_mtx);
455 if (db->db_state == DB_UNCACHED)
456 err = SET_ERROR(EIO);
457 mutex_exit(&db->db_mtx);
459 dmu_buf_rele_array(dbp, nblks, tag);
471 dmu_buf_hold_array(objset_t *os, uint64_t object, uint64_t offset,
472 uint64_t length, int read, void *tag, int *numbufsp, dmu_buf_t ***dbpp)
477 err = dnode_hold(os, object, FTAG, &dn);
481 err = dmu_buf_hold_array_by_dnode(dn, offset, length, read, tag,
482 numbufsp, dbpp, DMU_READ_PREFETCH);
484 dnode_rele(dn, FTAG);
490 dmu_buf_hold_array_by_bonus(dmu_buf_t *db_fake, uint64_t offset,
491 uint64_t length, int read, void *tag, int *numbufsp, dmu_buf_t ***dbpp)
493 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
499 err = dmu_buf_hold_array_by_dnode(dn, offset, length, read, tag,
500 numbufsp, dbpp, DMU_READ_PREFETCH);
507 dmu_buf_rele_array(dmu_buf_t **dbp_fake, int numbufs, void *tag)
510 dmu_buf_impl_t **dbp = (dmu_buf_impl_t **)dbp_fake;
515 for (i = 0; i < numbufs; i++) {
517 dbuf_rele(dbp[i], tag);
520 kmem_free(dbp, sizeof (dmu_buf_t *) * numbufs);
524 * Issue prefetch i/os for the given blocks.
526 * Note: The assumption is that we *know* these blocks will be needed
527 * almost immediately. Therefore, the prefetch i/os will be issued at
528 * ZIO_PRIORITY_SYNC_READ
530 * Note: indirect blocks and other metadata will be read synchronously,
531 * causing this function to block if they are not already cached.
534 dmu_prefetch(objset_t *os, uint64_t object, uint64_t offset, uint64_t len)
540 if (zfs_prefetch_disable)
543 if (len == 0) { /* they're interested in the bonus buffer */
544 dn = DMU_META_DNODE(os);
546 if (object == 0 || object >= DN_MAX_OBJECT)
549 rw_enter(&dn->dn_struct_rwlock, RW_READER);
550 blkid = dbuf_whichblock(dn, object * sizeof (dnode_phys_t));
551 dbuf_prefetch(dn, blkid, ZIO_PRIORITY_SYNC_READ);
552 rw_exit(&dn->dn_struct_rwlock);
557 * XXX - Note, if the dnode for the requested object is not
558 * already cached, we will do a *synchronous* read in the
559 * dnode_hold() call. The same is true for any indirects.
561 err = dnode_hold(os, object, FTAG, &dn);
565 rw_enter(&dn->dn_struct_rwlock, RW_READER);
566 if (dn->dn_datablkshift) {
567 int blkshift = dn->dn_datablkshift;
568 nblks = (P2ROUNDUP(offset + len, 1 << blkshift) -
569 P2ALIGN(offset, 1 << blkshift)) >> blkshift;
571 nblks = (offset < dn->dn_datablksz);
577 blkid = dbuf_whichblock(dn, offset);
578 for (i = 0; i < nblks; i++)
579 dbuf_prefetch(dn, blkid + i, ZIO_PRIORITY_SYNC_READ);
582 rw_exit(&dn->dn_struct_rwlock);
584 dnode_rele(dn, FTAG);
588 * Get the next "chunk" of file data to free. We traverse the file from
589 * the end so that the file gets shorter over time (if we crashes in the
590 * middle, this will leave us in a better state). We find allocated file
591 * data by simply searching the allocated level 1 indirects.
593 * On input, *start should be the first offset that does not need to be
594 * freed (e.g. "offset + length"). On return, *start will be the first
595 * offset that should be freed.
598 get_next_chunk(dnode_t *dn, uint64_t *start, uint64_t minimum)
600 uint64_t maxblks = DMU_MAX_ACCESS >> (dn->dn_indblkshift + 1);
601 /* bytes of data covered by a level-1 indirect block */
603 dn->dn_datablksz * EPB(dn->dn_indblkshift, SPA_BLKPTRSHIFT);
606 ASSERT3U(minimum, <=, *start);
608 if (*start - minimum <= iblkrange * maxblks) {
612 ASSERT(ISP2(iblkrange));
614 for (blks = 0; *start > minimum && blks < maxblks; blks++) {
618 * dnode_next_offset(BACKWARDS) will find an allocated L1
619 * indirect block at or before the input offset. We must
620 * decrement *start so that it is at the end of the region
624 err = dnode_next_offset(dn,
625 DNODE_FIND_BACKWARDS, start, 2, 1, 0);
627 /* if there are no indirect blocks before start, we are done */
631 } else if (err != 0) {
635 /* set start to the beginning of this L1 indirect */
636 *start = P2ALIGN(*start, iblkrange);
638 if (*start < minimum)
644 dmu_free_long_range_impl(objset_t *os, dnode_t *dn, uint64_t offset,
647 uint64_t object_size = (dn->dn_maxblkid + 1) * dn->dn_datablksz;
650 if (offset >= object_size)
653 if (length == DMU_OBJECT_END || offset + length > object_size)
654 length = object_size - offset;
656 while (length != 0) {
657 uint64_t chunk_end, chunk_begin;
660 chunk_end = chunk_begin = offset + length;
662 /* move chunk_begin backwards to the beginning of this chunk */
663 err = get_next_chunk(dn, &chunk_begin, offset);
666 ASSERT3U(chunk_begin, >=, offset);
667 ASSERT3U(chunk_begin, <=, chunk_end);
669 tx = dmu_tx_create(os);
670 dmu_tx_hold_free(tx, dn->dn_object,
671 chunk_begin, chunk_end - chunk_begin);
672 err = dmu_tx_assign(tx, TXG_WAIT);
677 dnode_free_range(dn, chunk_begin, chunk_end - chunk_begin, tx);
680 length -= chunk_end - chunk_begin;
686 dmu_free_long_range(objset_t *os, uint64_t object,
687 uint64_t offset, uint64_t length)
692 err = dnode_hold(os, object, FTAG, &dn);
695 err = dmu_free_long_range_impl(os, dn, offset, length);
698 * It is important to zero out the maxblkid when freeing the entire
699 * file, so that (a) subsequent calls to dmu_free_long_range_impl()
700 * will take the fast path, and (b) dnode_reallocate() can verify
701 * that the entire file has been freed.
703 if (err == 0 && offset == 0 && length == DMU_OBJECT_END)
706 dnode_rele(dn, FTAG);
711 dmu_free_long_object(objset_t *os, uint64_t object)
716 err = dmu_free_long_range(os, object, 0, DMU_OBJECT_END);
720 tx = dmu_tx_create(os);
721 dmu_tx_hold_bonus(tx, object);
722 dmu_tx_hold_free(tx, object, 0, DMU_OBJECT_END);
723 err = dmu_tx_assign(tx, TXG_WAIT);
725 err = dmu_object_free(os, object, tx);
735 dmu_free_range(objset_t *os, uint64_t object, uint64_t offset,
736 uint64_t size, dmu_tx_t *tx)
739 int err = dnode_hold(os, object, FTAG, &dn);
742 ASSERT(offset < UINT64_MAX);
743 ASSERT(size == -1ULL || size <= UINT64_MAX - offset);
744 dnode_free_range(dn, offset, size, tx);
745 dnode_rele(dn, FTAG);
750 dmu_read(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
751 void *buf, uint32_t flags)
757 err = dnode_hold(os, object, FTAG, &dn);
762 * Deal with odd block sizes, where there can't be data past the first
763 * block. If we ever do the tail block optimization, we will need to
764 * handle that here as well.
766 if (dn->dn_maxblkid == 0) {
767 int newsz = offset > dn->dn_datablksz ? 0 :
768 MIN(size, dn->dn_datablksz - offset);
769 bzero((char *)buf + newsz, size - newsz);
774 uint64_t mylen = MIN(size, DMU_MAX_ACCESS / 2);
778 * NB: we could do this block-at-a-time, but it's nice
779 * to be reading in parallel.
781 err = dmu_buf_hold_array_by_dnode(dn, offset, mylen,
782 TRUE, FTAG, &numbufs, &dbp, flags);
786 for (i = 0; i < numbufs; i++) {
789 dmu_buf_t *db = dbp[i];
793 bufoff = offset - db->db_offset;
794 tocpy = (int)MIN(db->db_size - bufoff, size);
796 bcopy((char *)db->db_data + bufoff, buf, tocpy);
800 buf = (char *)buf + tocpy;
802 dmu_buf_rele_array(dbp, numbufs, FTAG);
804 dnode_rele(dn, FTAG);
809 dmu_write(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
810 const void *buf, dmu_tx_t *tx)
818 VERIFY0(dmu_buf_hold_array(os, object, offset, size,
819 FALSE, FTAG, &numbufs, &dbp));
821 for (i = 0; i < numbufs; i++) {
824 dmu_buf_t *db = dbp[i];
828 bufoff = offset - db->db_offset;
829 tocpy = (int)MIN(db->db_size - bufoff, size);
831 ASSERT(i == 0 || i == numbufs-1 || tocpy == db->db_size);
833 if (tocpy == db->db_size)
834 dmu_buf_will_fill(db, tx);
836 dmu_buf_will_dirty(db, tx);
838 (void) memcpy((char *)db->db_data + bufoff, buf, tocpy);
840 if (tocpy == db->db_size)
841 dmu_buf_fill_done(db, tx);
845 buf = (char *)buf + tocpy;
847 dmu_buf_rele_array(dbp, numbufs, FTAG);
851 dmu_prealloc(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
860 VERIFY(0 == dmu_buf_hold_array(os, object, offset, size,
861 FALSE, FTAG, &numbufs, &dbp));
863 for (i = 0; i < numbufs; i++) {
864 dmu_buf_t *db = dbp[i];
866 dmu_buf_will_not_fill(db, tx);
868 dmu_buf_rele_array(dbp, numbufs, FTAG);
872 dmu_write_embedded(objset_t *os, uint64_t object, uint64_t offset,
873 void *data, uint8_t etype, uint8_t comp, int uncompressed_size,
874 int compressed_size, int byteorder, dmu_tx_t *tx)
878 ASSERT3U(etype, <, NUM_BP_EMBEDDED_TYPES);
879 ASSERT3U(comp, <, ZIO_COMPRESS_FUNCTIONS);
880 VERIFY0(dmu_buf_hold_noread(os, object, offset,
883 dmu_buf_write_embedded(db,
884 data, (bp_embedded_type_t)etype, (enum zio_compress)comp,
885 uncompressed_size, compressed_size, byteorder, tx);
887 dmu_buf_rele(db, FTAG);
891 * DMU support for xuio
893 kstat_t *xuio_ksp = NULL;
895 typedef struct xuio_stats {
896 /* loaned yet not returned arc_buf */
897 kstat_named_t xuiostat_onloan_rbuf;
898 kstat_named_t xuiostat_onloan_wbuf;
899 /* whether a copy is made when loaning out a read buffer */
900 kstat_named_t xuiostat_rbuf_copied;
901 kstat_named_t xuiostat_rbuf_nocopy;
902 /* whether a copy is made when assigning a write buffer */
903 kstat_named_t xuiostat_wbuf_copied;
904 kstat_named_t xuiostat_wbuf_nocopy;
907 static xuio_stats_t xuio_stats = {
908 { "onloan_read_buf", KSTAT_DATA_UINT64 },
909 { "onloan_write_buf", KSTAT_DATA_UINT64 },
910 { "read_buf_copied", KSTAT_DATA_UINT64 },
911 { "read_buf_nocopy", KSTAT_DATA_UINT64 },
912 { "write_buf_copied", KSTAT_DATA_UINT64 },
913 { "write_buf_nocopy", KSTAT_DATA_UINT64 }
916 #define XUIOSTAT_INCR(stat, val) \
917 atomic_add_64(&xuio_stats.stat.value.ui64, (val))
918 #define XUIOSTAT_BUMP(stat) XUIOSTAT_INCR(stat, 1)
921 dmu_xuio_init(xuio_t *xuio, int nblk)
924 uio_t *uio = &xuio->xu_uio;
926 uio->uio_iovcnt = nblk;
927 uio->uio_iov = kmem_zalloc(nblk * sizeof (iovec_t), KM_SLEEP);
929 priv = kmem_zalloc(sizeof (dmu_xuio_t), KM_SLEEP);
931 priv->bufs = kmem_zalloc(nblk * sizeof (arc_buf_t *), KM_SLEEP);
932 priv->iovp = uio->uio_iov;
933 XUIO_XUZC_PRIV(xuio) = priv;
935 if (XUIO_XUZC_RW(xuio) == UIO_READ)
936 XUIOSTAT_INCR(xuiostat_onloan_rbuf, nblk);
938 XUIOSTAT_INCR(xuiostat_onloan_wbuf, nblk);
944 dmu_xuio_fini(xuio_t *xuio)
946 dmu_xuio_t *priv = XUIO_XUZC_PRIV(xuio);
947 int nblk = priv->cnt;
949 kmem_free(priv->iovp, nblk * sizeof (iovec_t));
950 kmem_free(priv->bufs, nblk * sizeof (arc_buf_t *));
951 kmem_free(priv, sizeof (dmu_xuio_t));
953 if (XUIO_XUZC_RW(xuio) == UIO_READ)
954 XUIOSTAT_INCR(xuiostat_onloan_rbuf, -nblk);
956 XUIOSTAT_INCR(xuiostat_onloan_wbuf, -nblk);
960 * Initialize iov[priv->next] and priv->bufs[priv->next] with { off, n, abuf }
961 * and increase priv->next by 1.
964 dmu_xuio_add(xuio_t *xuio, arc_buf_t *abuf, offset_t off, size_t n)
967 uio_t *uio = &xuio->xu_uio;
968 dmu_xuio_t *priv = XUIO_XUZC_PRIV(xuio);
969 int i = priv->next++;
971 ASSERT(i < priv->cnt);
972 ASSERT(off + n <= arc_buf_size(abuf));
973 iov = uio->uio_iov + i;
974 iov->iov_base = (char *)abuf->b_data + off;
976 priv->bufs[i] = abuf;
981 dmu_xuio_cnt(xuio_t *xuio)
983 dmu_xuio_t *priv = XUIO_XUZC_PRIV(xuio);
988 dmu_xuio_arcbuf(xuio_t *xuio, int i)
990 dmu_xuio_t *priv = XUIO_XUZC_PRIV(xuio);
992 ASSERT(i < priv->cnt);
993 return (priv->bufs[i]);
997 dmu_xuio_clear(xuio_t *xuio, int i)
999 dmu_xuio_t *priv = XUIO_XUZC_PRIV(xuio);
1001 ASSERT(i < priv->cnt);
1002 priv->bufs[i] = NULL;
1006 xuio_stat_init(void)
1008 xuio_ksp = kstat_create("zfs", 0, "xuio_stats", "misc",
1009 KSTAT_TYPE_NAMED, sizeof (xuio_stats) / sizeof (kstat_named_t),
1010 KSTAT_FLAG_VIRTUAL);
1011 if (xuio_ksp != NULL) {
1012 xuio_ksp->ks_data = &xuio_stats;
1013 kstat_install(xuio_ksp);
1018 xuio_stat_fini(void)
1020 if (xuio_ksp != NULL) {
1021 kstat_delete(xuio_ksp);
1027 xuio_stat_wbuf_copied()
1029 XUIOSTAT_BUMP(xuiostat_wbuf_copied);
1033 xuio_stat_wbuf_nocopy()
1035 XUIOSTAT_BUMP(xuiostat_wbuf_nocopy);
1041 * Copy up to size bytes between arg_buf and req based on the data direction
1042 * described by the req. If an entire req's data cannot be transfered in one
1043 * pass, you should pass in @req_offset to indicate where to continue. The
1044 * return value is the number of bytes successfully copied to arg_buf.
1047 dmu_req_copy(void *arg_buf, int size, struct request *req, size_t req_offset)
1049 struct bio_vec bv, *bvp;
1050 struct req_iterator iter;
1052 int tocpy, bv_len, bv_offset;
1055 rq_for_each_segment4(bv, bvp, req, iter) {
1057 * Fully consumed the passed arg_buf. We use goto here because
1058 * rq_for_each_segment is a double loop
1060 ASSERT3S(offset, <=, size);
1064 /* Skip already copied bv */
1065 if (req_offset >= bv.bv_len) {
1066 req_offset -= bv.bv_len;
1070 bv_len = bv.bv_len - req_offset;
1071 bv_offset = bv.bv_offset + req_offset;
1074 tocpy = MIN(bv_len, size - offset);
1075 ASSERT3S(tocpy, >=, 0);
1077 bv_buf = page_address(bv.bv_page) + bv_offset;
1078 ASSERT3P(bv_buf, !=, NULL);
1080 if (rq_data_dir(req) == WRITE)
1081 memcpy(arg_buf + offset, bv_buf, tocpy);
1083 memcpy(bv_buf, arg_buf + offset, tocpy);
1092 dmu_read_req(objset_t *os, uint64_t object, struct request *req)
1094 uint64_t size = blk_rq_bytes(req);
1095 uint64_t offset = blk_rq_pos(req) << 9;
1097 int numbufs, i, err;
1101 * NB: we could do this block-at-a-time, but it's nice
1102 * to be reading in parallel.
1104 err = dmu_buf_hold_array(os, object, offset, size, TRUE, FTAG,
1110 for (i = 0; i < numbufs; i++) {
1111 int tocpy, didcpy, bufoff;
1112 dmu_buf_t *db = dbp[i];
1114 bufoff = offset - db->db_offset;
1115 ASSERT3S(bufoff, >=, 0);
1117 tocpy = (int)MIN(db->db_size - bufoff, size);
1121 didcpy = dmu_req_copy(db->db_data + bufoff, tocpy, req,
1132 req_offset += didcpy;
1135 dmu_buf_rele_array(dbp, numbufs, FTAG);
1141 dmu_write_req(objset_t *os, uint64_t object, struct request *req, dmu_tx_t *tx)
1143 uint64_t size = blk_rq_bytes(req);
1144 uint64_t offset = blk_rq_pos(req) << 9;
1146 int numbufs, i, err;
1152 err = dmu_buf_hold_array(os, object, offset, size, FALSE, FTAG,
1158 for (i = 0; i < numbufs; i++) {
1159 int tocpy, didcpy, bufoff;
1160 dmu_buf_t *db = dbp[i];
1162 bufoff = offset - db->db_offset;
1163 ASSERT3S(bufoff, >=, 0);
1165 tocpy = (int)MIN(db->db_size - bufoff, size);
1169 ASSERT(i == 0 || i == numbufs-1 || tocpy == db->db_size);
1171 if (tocpy == db->db_size)
1172 dmu_buf_will_fill(db, tx);
1174 dmu_buf_will_dirty(db, tx);
1176 didcpy = dmu_req_copy(db->db_data + bufoff, tocpy, req,
1179 if (tocpy == db->db_size)
1180 dmu_buf_fill_done(db, tx);
1190 req_offset += didcpy;
1194 dmu_buf_rele_array(dbp, numbufs, FTAG);
1199 dmu_read_uio(objset_t *os, uint64_t object, uio_t *uio, uint64_t size)
1202 int numbufs, i, err;
1203 xuio_t *xuio = NULL;
1206 * NB: we could do this block-at-a-time, but it's nice
1207 * to be reading in parallel.
1209 err = dmu_buf_hold_array(os, object, uio->uio_loffset, size, TRUE, FTAG,
1214 for (i = 0; i < numbufs; i++) {
1217 dmu_buf_t *db = dbp[i];
1221 bufoff = uio->uio_loffset - db->db_offset;
1222 tocpy = (int)MIN(db->db_size - bufoff, size);
1225 dmu_buf_impl_t *dbi = (dmu_buf_impl_t *)db;
1226 arc_buf_t *dbuf_abuf = dbi->db_buf;
1227 arc_buf_t *abuf = dbuf_loan_arcbuf(dbi);
1228 err = dmu_xuio_add(xuio, abuf, bufoff, tocpy);
1230 uio->uio_resid -= tocpy;
1231 uio->uio_loffset += tocpy;
1234 if (abuf == dbuf_abuf)
1235 XUIOSTAT_BUMP(xuiostat_rbuf_nocopy);
1237 XUIOSTAT_BUMP(xuiostat_rbuf_copied);
1239 err = uiomove((char *)db->db_data + bufoff, tocpy,
1247 dmu_buf_rele_array(dbp, numbufs, FTAG);
1253 dmu_write_uio_dnode(dnode_t *dn, uio_t *uio, uint64_t size, dmu_tx_t *tx)
1260 err = dmu_buf_hold_array_by_dnode(dn, uio->uio_loffset, size,
1261 FALSE, FTAG, &numbufs, &dbp, DMU_READ_PREFETCH);
1265 for (i = 0; i < numbufs; i++) {
1268 dmu_buf_t *db = dbp[i];
1272 bufoff = uio->uio_loffset - db->db_offset;
1273 tocpy = (int)MIN(db->db_size - bufoff, size);
1275 ASSERT(i == 0 || i == numbufs-1 || tocpy == db->db_size);
1277 if (tocpy == db->db_size)
1278 dmu_buf_will_fill(db, tx);
1280 dmu_buf_will_dirty(db, tx);
1283 * XXX uiomove could block forever (eg.nfs-backed
1284 * pages). There needs to be a uiolockdown() function
1285 * to lock the pages in memory, so that uiomove won't
1288 err = uiomove((char *)db->db_data + bufoff, tocpy,
1291 if (tocpy == db->db_size)
1292 dmu_buf_fill_done(db, tx);
1300 dmu_buf_rele_array(dbp, numbufs, FTAG);
1305 dmu_write_uio_dbuf(dmu_buf_t *zdb, uio_t *uio, uint64_t size,
1308 dmu_buf_impl_t *db = (dmu_buf_impl_t *)zdb;
1317 err = dmu_write_uio_dnode(dn, uio, size, tx);
1324 dmu_write_uio(objset_t *os, uint64_t object, uio_t *uio, uint64_t size,
1333 err = dnode_hold(os, object, FTAG, &dn);
1337 err = dmu_write_uio_dnode(dn, uio, size, tx);
1339 dnode_rele(dn, FTAG);
1343 #endif /* _KERNEL */
1346 * Allocate a loaned anonymous arc buffer.
1349 dmu_request_arcbuf(dmu_buf_t *handle, int size)
1351 dmu_buf_impl_t *db = (dmu_buf_impl_t *)handle;
1353 return (arc_loan_buf(db->db_objset->os_spa, size));
1357 * Free a loaned arc buffer.
1360 dmu_return_arcbuf(arc_buf_t *buf)
1362 arc_return_buf(buf, FTAG);
1363 VERIFY(arc_buf_remove_ref(buf, FTAG));
1367 * When possible directly assign passed loaned arc buffer to a dbuf.
1368 * If this is not possible copy the contents of passed arc buf via
1372 dmu_assign_arcbuf(dmu_buf_t *handle, uint64_t offset, arc_buf_t *buf,
1375 dmu_buf_impl_t *dbuf = (dmu_buf_impl_t *)handle;
1378 uint32_t blksz = (uint32_t)arc_buf_size(buf);
1381 DB_DNODE_ENTER(dbuf);
1382 dn = DB_DNODE(dbuf);
1383 rw_enter(&dn->dn_struct_rwlock, RW_READER);
1384 blkid = dbuf_whichblock(dn, offset);
1385 VERIFY((db = dbuf_hold(dn, blkid, FTAG)) != NULL);
1386 rw_exit(&dn->dn_struct_rwlock);
1387 DB_DNODE_EXIT(dbuf);
1390 * We can only assign if the offset is aligned, the arc buf is the
1391 * same size as the dbuf, and the dbuf is not metadata. It
1392 * can't be metadata because the loaned arc buf comes from the
1393 * user-data kmem area.
1395 if (offset == db->db.db_offset && blksz == db->db.db_size &&
1396 DBUF_GET_BUFC_TYPE(db) == ARC_BUFC_DATA) {
1397 dbuf_assign_arcbuf(db, buf, tx);
1398 dbuf_rele(db, FTAG);
1403 DB_DNODE_ENTER(dbuf);
1404 dn = DB_DNODE(dbuf);
1406 object = dn->dn_object;
1407 DB_DNODE_EXIT(dbuf);
1409 dbuf_rele(db, FTAG);
1410 dmu_write(os, object, offset, blksz, buf->b_data, tx);
1411 dmu_return_arcbuf(buf);
1412 XUIOSTAT_BUMP(xuiostat_wbuf_copied);
1417 dbuf_dirty_record_t *dsa_dr;
1418 dmu_sync_cb_t *dsa_done;
1425 dmu_sync_ready(zio_t *zio, arc_buf_t *buf, void *varg)
1427 dmu_sync_arg_t *dsa = varg;
1428 dmu_buf_t *db = dsa->dsa_zgd->zgd_db;
1429 blkptr_t *bp = zio->io_bp;
1431 if (zio->io_error == 0) {
1432 if (BP_IS_HOLE(bp)) {
1434 * A block of zeros may compress to a hole, but the
1435 * block size still needs to be known for replay.
1437 BP_SET_LSIZE(bp, db->db_size);
1438 } else if (!BP_IS_EMBEDDED(bp)) {
1439 ASSERT(BP_GET_LEVEL(bp) == 0);
1446 dmu_sync_late_arrival_ready(zio_t *zio)
1448 dmu_sync_ready(zio, NULL, zio->io_private);
1453 dmu_sync_done(zio_t *zio, arc_buf_t *buf, void *varg)
1455 dmu_sync_arg_t *dsa = varg;
1456 dbuf_dirty_record_t *dr = dsa->dsa_dr;
1457 dmu_buf_impl_t *db = dr->dr_dbuf;
1459 mutex_enter(&db->db_mtx);
1460 ASSERT(dr->dt.dl.dr_override_state == DR_IN_DMU_SYNC);
1461 if (zio->io_error == 0) {
1462 dr->dt.dl.dr_nopwrite = !!(zio->io_flags & ZIO_FLAG_NOPWRITE);
1463 if (dr->dt.dl.dr_nopwrite) {
1464 ASSERTV(blkptr_t *bp = zio->io_bp);
1465 ASSERTV(blkptr_t *bp_orig = &zio->io_bp_orig);
1466 ASSERTV(uint8_t chksum = BP_GET_CHECKSUM(bp_orig));
1468 ASSERT(BP_EQUAL(bp, bp_orig));
1469 ASSERT(zio->io_prop.zp_compress != ZIO_COMPRESS_OFF);
1470 ASSERT(zio_checksum_table[chksum].ci_dedup);
1472 dr->dt.dl.dr_overridden_by = *zio->io_bp;
1473 dr->dt.dl.dr_override_state = DR_OVERRIDDEN;
1474 dr->dt.dl.dr_copies = zio->io_prop.zp_copies;
1477 * Old style holes are filled with all zeros, whereas
1478 * new-style holes maintain their lsize, type, level,
1479 * and birth time (see zio_write_compress). While we
1480 * need to reset the BP_SET_LSIZE() call that happened
1481 * in dmu_sync_ready for old style holes, we do *not*
1482 * want to wipe out the information contained in new
1483 * style holes. Thus, only zero out the block pointer if
1484 * it's an old style hole.
1486 if (BP_IS_HOLE(&dr->dt.dl.dr_overridden_by) &&
1487 dr->dt.dl.dr_overridden_by.blk_birth == 0)
1488 BP_ZERO(&dr->dt.dl.dr_overridden_by);
1490 dr->dt.dl.dr_override_state = DR_NOT_OVERRIDDEN;
1492 cv_broadcast(&db->db_changed);
1493 mutex_exit(&db->db_mtx);
1495 dsa->dsa_done(dsa->dsa_zgd, zio->io_error);
1497 kmem_free(dsa, sizeof (*dsa));
1501 dmu_sync_late_arrival_done(zio_t *zio)
1503 blkptr_t *bp = zio->io_bp;
1504 dmu_sync_arg_t *dsa = zio->io_private;
1505 ASSERTV(blkptr_t *bp_orig = &zio->io_bp_orig);
1507 if (zio->io_error == 0 && !BP_IS_HOLE(bp)) {
1509 * If we didn't allocate a new block (i.e. ZIO_FLAG_NOPWRITE)
1510 * then there is nothing to do here. Otherwise, free the
1511 * newly allocated block in this txg.
1513 if (zio->io_flags & ZIO_FLAG_NOPWRITE) {
1514 ASSERT(BP_EQUAL(bp, bp_orig));
1516 ASSERT(BP_IS_HOLE(bp_orig) || !BP_EQUAL(bp, bp_orig));
1517 ASSERT(zio->io_bp->blk_birth == zio->io_txg);
1518 ASSERT(zio->io_txg > spa_syncing_txg(zio->io_spa));
1519 zio_free(zio->io_spa, zio->io_txg, zio->io_bp);
1523 dmu_tx_commit(dsa->dsa_tx);
1525 dsa->dsa_done(dsa->dsa_zgd, zio->io_error);
1527 kmem_free(dsa, sizeof (*dsa));
1531 dmu_sync_late_arrival(zio_t *pio, objset_t *os, dmu_sync_cb_t *done, zgd_t *zgd,
1532 zio_prop_t *zp, zbookmark_phys_t *zb)
1534 dmu_sync_arg_t *dsa;
1537 tx = dmu_tx_create(os);
1538 dmu_tx_hold_space(tx, zgd->zgd_db->db_size);
1539 if (dmu_tx_assign(tx, TXG_WAIT) != 0) {
1541 /* Make zl_get_data do txg_waited_synced() */
1542 return (SET_ERROR(EIO));
1545 dsa = kmem_alloc(sizeof (dmu_sync_arg_t), KM_SLEEP);
1547 dsa->dsa_done = done;
1551 zio_nowait(zio_write(pio, os->os_spa, dmu_tx_get_txg(tx), zgd->zgd_bp,
1552 zgd->zgd_db->db_data, zgd->zgd_db->db_size, zp,
1553 dmu_sync_late_arrival_ready, NULL, dmu_sync_late_arrival_done, dsa,
1554 ZIO_PRIORITY_SYNC_WRITE, ZIO_FLAG_CANFAIL|ZIO_FLAG_FASTWRITE, zb));
1560 * Intent log support: sync the block associated with db to disk.
1561 * N.B. and XXX: the caller is responsible for making sure that the
1562 * data isn't changing while dmu_sync() is writing it.
1566 * EEXIST: this txg has already been synced, so there's nothing to do.
1567 * The caller should not log the write.
1569 * ENOENT: the block was dbuf_free_range()'d, so there's nothing to do.
1570 * The caller should not log the write.
1572 * EALREADY: this block is already in the process of being synced.
1573 * The caller should track its progress (somehow).
1575 * EIO: could not do the I/O.
1576 * The caller should do a txg_wait_synced().
1578 * 0: the I/O has been initiated.
1579 * The caller should log this blkptr in the done callback.
1580 * It is possible that the I/O will fail, in which case
1581 * the error will be reported to the done callback and
1582 * propagated to pio from zio_done().
1585 dmu_sync(zio_t *pio, uint64_t txg, dmu_sync_cb_t *done, zgd_t *zgd)
1587 blkptr_t *bp = zgd->zgd_bp;
1588 dmu_buf_impl_t *db = (dmu_buf_impl_t *)zgd->zgd_db;
1589 objset_t *os = db->db_objset;
1590 dsl_dataset_t *ds = os->os_dsl_dataset;
1591 dbuf_dirty_record_t *dr;
1592 dmu_sync_arg_t *dsa;
1593 zbookmark_phys_t zb;
1597 ASSERT(pio != NULL);
1600 SET_BOOKMARK(&zb, ds->ds_object,
1601 db->db.db_object, db->db_level, db->db_blkid);
1605 dmu_write_policy(os, dn, db->db_level, WP_DMU_SYNC, &zp);
1609 * If we're frozen (running ziltest), we always need to generate a bp.
1611 if (txg > spa_freeze_txg(os->os_spa))
1612 return (dmu_sync_late_arrival(pio, os, done, zgd, &zp, &zb));
1615 * Grabbing db_mtx now provides a barrier between dbuf_sync_leaf()
1616 * and us. If we determine that this txg is not yet syncing,
1617 * but it begins to sync a moment later, that's OK because the
1618 * sync thread will block in dbuf_sync_leaf() until we drop db_mtx.
1620 mutex_enter(&db->db_mtx);
1622 if (txg <= spa_last_synced_txg(os->os_spa)) {
1624 * This txg has already synced. There's nothing to do.
1626 mutex_exit(&db->db_mtx);
1627 return (SET_ERROR(EEXIST));
1630 if (txg <= spa_syncing_txg(os->os_spa)) {
1632 * This txg is currently syncing, so we can't mess with
1633 * the dirty record anymore; just write a new log block.
1635 mutex_exit(&db->db_mtx);
1636 return (dmu_sync_late_arrival(pio, os, done, zgd, &zp, &zb));
1639 dr = db->db_last_dirty;
1640 while (dr && dr->dr_txg != txg)
1645 * There's no dr for this dbuf, so it must have been freed.
1646 * There's no need to log writes to freed blocks, so we're done.
1648 mutex_exit(&db->db_mtx);
1649 return (SET_ERROR(ENOENT));
1652 ASSERT(dr->dr_next == NULL || dr->dr_next->dr_txg < txg);
1655 * Assume the on-disk data is X, the current syncing data is Y,
1656 * and the current in-memory data is Z (currently in dmu_sync).
1657 * X and Z are identical but Y is has been modified. Normally,
1658 * when X and Z are the same we will perform a nopwrite but if Y
1659 * is different we must disable nopwrite since the resulting write
1660 * of Y to disk can free the block containing X. If we allowed a
1661 * nopwrite to occur the block pointing to Z would reference a freed
1662 * block. Since this is a rare case we simplify this by disabling
1663 * nopwrite if the current dmu_sync-ing dbuf has been modified in
1664 * a previous transaction.
1667 zp.zp_nopwrite = B_FALSE;
1669 ASSERT(dr->dr_txg == txg);
1670 if (dr->dt.dl.dr_override_state == DR_IN_DMU_SYNC ||
1671 dr->dt.dl.dr_override_state == DR_OVERRIDDEN) {
1673 * We have already issued a sync write for this buffer,
1674 * or this buffer has already been synced. It could not
1675 * have been dirtied since, or we would have cleared the state.
1677 mutex_exit(&db->db_mtx);
1678 return (SET_ERROR(EALREADY));
1681 ASSERT(dr->dt.dl.dr_override_state == DR_NOT_OVERRIDDEN);
1682 dr->dt.dl.dr_override_state = DR_IN_DMU_SYNC;
1683 mutex_exit(&db->db_mtx);
1685 dsa = kmem_alloc(sizeof (dmu_sync_arg_t), KM_SLEEP);
1687 dsa->dsa_done = done;
1691 zio_nowait(arc_write(pio, os->os_spa, txg,
1692 bp, dr->dt.dl.dr_data, DBUF_IS_L2CACHEABLE(db),
1693 DBUF_IS_L2COMPRESSIBLE(db), &zp, dmu_sync_ready,
1694 NULL, dmu_sync_done, dsa, ZIO_PRIORITY_SYNC_WRITE,
1695 ZIO_FLAG_CANFAIL, &zb));
1701 dmu_object_set_blocksize(objset_t *os, uint64_t object, uint64_t size, int ibs,
1707 err = dnode_hold(os, object, FTAG, &dn);
1710 err = dnode_set_blksz(dn, size, ibs, tx);
1711 dnode_rele(dn, FTAG);
1716 dmu_object_set_checksum(objset_t *os, uint64_t object, uint8_t checksum,
1722 * Send streams include each object's checksum function. This
1723 * check ensures that the receiving system can understand the
1724 * checksum function transmitted.
1726 ASSERT3U(checksum, <, ZIO_CHECKSUM_LEGACY_FUNCTIONS);
1728 VERIFY0(dnode_hold(os, object, FTAG, &dn));
1729 ASSERT3U(checksum, <, ZIO_CHECKSUM_FUNCTIONS);
1730 dn->dn_checksum = checksum;
1731 dnode_setdirty(dn, tx);
1732 dnode_rele(dn, FTAG);
1736 dmu_object_set_compress(objset_t *os, uint64_t object, uint8_t compress,
1742 * Send streams include each object's compression function. This
1743 * check ensures that the receiving system can understand the
1744 * compression function transmitted.
1746 ASSERT3U(compress, <, ZIO_COMPRESS_LEGACY_FUNCTIONS);
1748 VERIFY0(dnode_hold(os, object, FTAG, &dn));
1749 dn->dn_compress = compress;
1750 dnode_setdirty(dn, tx);
1751 dnode_rele(dn, FTAG);
1754 int zfs_mdcomp_disable = 0;
1757 * When the "redundant_metadata" property is set to "most", only indirect
1758 * blocks of this level and higher will have an additional ditto block.
1760 int zfs_redundant_metadata_most_ditto_level = 2;
1763 dmu_write_policy(objset_t *os, dnode_t *dn, int level, int wp, zio_prop_t *zp)
1765 dmu_object_type_t type = dn ? dn->dn_type : DMU_OT_OBJSET;
1766 boolean_t ismd = (level > 0 || DMU_OT_IS_METADATA(type) ||
1768 enum zio_checksum checksum = os->os_checksum;
1769 enum zio_compress compress = os->os_compress;
1770 enum zio_checksum dedup_checksum = os->os_dedup_checksum;
1771 boolean_t dedup = B_FALSE;
1772 boolean_t nopwrite = B_FALSE;
1773 boolean_t dedup_verify = os->os_dedup_verify;
1774 int copies = os->os_copies;
1777 * We maintain different write policies for each of the following
1780 * 2. preallocated blocks (i.e. level-0 blocks of a dump device)
1781 * 3. all other level 0 blocks
1785 * XXX -- we should design a compression algorithm
1786 * that specializes in arrays of bps.
1788 boolean_t lz4_ac = spa_feature_is_active(os->os_spa,
1789 SPA_FEATURE_LZ4_COMPRESS);
1791 if (zfs_mdcomp_disable) {
1792 compress = ZIO_COMPRESS_EMPTY;
1793 } else if (lz4_ac) {
1794 compress = ZIO_COMPRESS_LZ4;
1796 compress = ZIO_COMPRESS_LZJB;
1800 * Metadata always gets checksummed. If the data
1801 * checksum is multi-bit correctable, and it's not a
1802 * ZBT-style checksum, then it's suitable for metadata
1803 * as well. Otherwise, the metadata checksum defaults
1806 if (zio_checksum_table[checksum].ci_correctable < 1 ||
1807 zio_checksum_table[checksum].ci_eck)
1808 checksum = ZIO_CHECKSUM_FLETCHER_4;
1810 if (os->os_redundant_metadata == ZFS_REDUNDANT_METADATA_ALL ||
1811 (os->os_redundant_metadata ==
1812 ZFS_REDUNDANT_METADATA_MOST &&
1813 (level >= zfs_redundant_metadata_most_ditto_level ||
1814 DMU_OT_IS_METADATA(type) || (wp & WP_SPILL))))
1816 } else if (wp & WP_NOFILL) {
1820 * If we're writing preallocated blocks, we aren't actually
1821 * writing them so don't set any policy properties. These
1822 * blocks are currently only used by an external subsystem
1823 * outside of zfs (i.e. dump) and not written by the zio
1826 compress = ZIO_COMPRESS_OFF;
1827 checksum = ZIO_CHECKSUM_OFF;
1829 compress = zio_compress_select(dn->dn_compress, compress);
1831 checksum = (dedup_checksum == ZIO_CHECKSUM_OFF) ?
1832 zio_checksum_select(dn->dn_checksum, checksum) :
1836 * Determine dedup setting. If we are in dmu_sync(),
1837 * we won't actually dedup now because that's all
1838 * done in syncing context; but we do want to use the
1839 * dedup checkum. If the checksum is not strong
1840 * enough to ensure unique signatures, force
1843 if (dedup_checksum != ZIO_CHECKSUM_OFF) {
1844 dedup = (wp & WP_DMU_SYNC) ? B_FALSE : B_TRUE;
1845 if (!zio_checksum_table[checksum].ci_dedup)
1846 dedup_verify = B_TRUE;
1850 * Enable nopwrite if we have a cryptographically secure
1851 * checksum that has no known collisions (i.e. SHA-256)
1852 * and compression is enabled. We don't enable nopwrite if
1853 * dedup is enabled as the two features are mutually exclusive.
1855 nopwrite = (!dedup && zio_checksum_table[checksum].ci_dedup &&
1856 compress != ZIO_COMPRESS_OFF && zfs_nopwrite_enabled);
1859 zp->zp_checksum = checksum;
1860 zp->zp_compress = compress;
1861 zp->zp_type = (wp & WP_SPILL) ? dn->dn_bonustype : type;
1862 zp->zp_level = level;
1863 zp->zp_copies = MIN(copies, spa_max_replication(os->os_spa));
1864 zp->zp_dedup = dedup;
1865 zp->zp_dedup_verify = dedup && dedup_verify;
1866 zp->zp_nopwrite = nopwrite;
1870 dmu_offset_next(objset_t *os, uint64_t object, boolean_t hole, uint64_t *off)
1875 err = dnode_hold(os, object, FTAG, &dn);
1879 * Sync any current changes before
1880 * we go trundling through the block pointers.
1882 for (i = 0; i < TXG_SIZE; i++) {
1883 if (list_link_active(&dn->dn_dirty_link[i]))
1886 if (i != TXG_SIZE) {
1887 dnode_rele(dn, FTAG);
1888 txg_wait_synced(dmu_objset_pool(os), 0);
1889 err = dnode_hold(os, object, FTAG, &dn);
1894 err = dnode_next_offset(dn, (hole ? DNODE_FIND_HOLE : 0), off, 1, 1, 0);
1895 dnode_rele(dn, FTAG);
1901 __dmu_object_info_from_dnode(dnode_t *dn, dmu_object_info_t *doi)
1903 dnode_phys_t *dnp = dn->dn_phys;
1906 doi->doi_data_block_size = dn->dn_datablksz;
1907 doi->doi_metadata_block_size = dn->dn_indblkshift ?
1908 1ULL << dn->dn_indblkshift : 0;
1909 doi->doi_type = dn->dn_type;
1910 doi->doi_bonus_type = dn->dn_bonustype;
1911 doi->doi_bonus_size = dn->dn_bonuslen;
1912 doi->doi_indirection = dn->dn_nlevels;
1913 doi->doi_checksum = dn->dn_checksum;
1914 doi->doi_compress = dn->dn_compress;
1915 doi->doi_nblkptr = dn->dn_nblkptr;
1916 doi->doi_physical_blocks_512 = (DN_USED_BYTES(dnp) + 256) >> 9;
1917 doi->doi_max_offset = (dn->dn_maxblkid + 1) * dn->dn_datablksz;
1918 doi->doi_fill_count = 0;
1919 for (i = 0; i < dnp->dn_nblkptr; i++)
1920 doi->doi_fill_count += BP_GET_FILL(&dnp->dn_blkptr[i]);
1924 dmu_object_info_from_dnode(dnode_t *dn, dmu_object_info_t *doi)
1926 rw_enter(&dn->dn_struct_rwlock, RW_READER);
1927 mutex_enter(&dn->dn_mtx);
1929 __dmu_object_info_from_dnode(dn, doi);
1931 mutex_exit(&dn->dn_mtx);
1932 rw_exit(&dn->dn_struct_rwlock);
1936 * Get information on a DMU object.
1937 * If doi is NULL, just indicates whether the object exists.
1940 dmu_object_info(objset_t *os, uint64_t object, dmu_object_info_t *doi)
1943 int err = dnode_hold(os, object, FTAG, &dn);
1949 dmu_object_info_from_dnode(dn, doi);
1951 dnode_rele(dn, FTAG);
1956 * As above, but faster; can be used when you have a held dbuf in hand.
1959 dmu_object_info_from_db(dmu_buf_t *db_fake, dmu_object_info_t *doi)
1961 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
1964 dmu_object_info_from_dnode(DB_DNODE(db), doi);
1969 * Faster still when you only care about the size.
1970 * This is specifically optimized for zfs_getattr().
1973 dmu_object_size_from_db(dmu_buf_t *db_fake, uint32_t *blksize,
1974 u_longlong_t *nblk512)
1976 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
1982 *blksize = dn->dn_datablksz;
1983 /* add 1 for dnode space */
1984 *nblk512 = ((DN_USED_BYTES(dn->dn_phys) + SPA_MINBLOCKSIZE/2) >>
1985 SPA_MINBLOCKSHIFT) + 1;
1990 byteswap_uint64_array(void *vbuf, size_t size)
1992 uint64_t *buf = vbuf;
1993 size_t count = size >> 3;
1996 ASSERT((size & 7) == 0);
1998 for (i = 0; i < count; i++)
1999 buf[i] = BSWAP_64(buf[i]);
2003 byteswap_uint32_array(void *vbuf, size_t size)
2005 uint32_t *buf = vbuf;
2006 size_t count = size >> 2;
2009 ASSERT((size & 3) == 0);
2011 for (i = 0; i < count; i++)
2012 buf[i] = BSWAP_32(buf[i]);
2016 byteswap_uint16_array(void *vbuf, size_t size)
2018 uint16_t *buf = vbuf;
2019 size_t count = size >> 1;
2022 ASSERT((size & 1) == 0);
2024 for (i = 0; i < count; i++)
2025 buf[i] = BSWAP_16(buf[i]);
2030 byteswap_uint8_array(void *vbuf, size_t size)
2052 arc_fini(); /* arc depends on l2arc, so arc must go first */
2064 #if defined(_KERNEL) && defined(HAVE_SPL)
2065 EXPORT_SYMBOL(dmu_bonus_hold);
2066 EXPORT_SYMBOL(dmu_buf_hold_array_by_bonus);
2067 EXPORT_SYMBOL(dmu_buf_rele_array);
2068 EXPORT_SYMBOL(dmu_prefetch);
2069 EXPORT_SYMBOL(dmu_free_range);
2070 EXPORT_SYMBOL(dmu_free_long_range);
2071 EXPORT_SYMBOL(dmu_free_long_object);
2072 EXPORT_SYMBOL(dmu_read);
2073 EXPORT_SYMBOL(dmu_write);
2074 EXPORT_SYMBOL(dmu_prealloc);
2075 EXPORT_SYMBOL(dmu_object_info);
2076 EXPORT_SYMBOL(dmu_object_info_from_dnode);
2077 EXPORT_SYMBOL(dmu_object_info_from_db);
2078 EXPORT_SYMBOL(dmu_object_size_from_db);
2079 EXPORT_SYMBOL(dmu_object_set_blocksize);
2080 EXPORT_SYMBOL(dmu_object_set_checksum);
2081 EXPORT_SYMBOL(dmu_object_set_compress);
2082 EXPORT_SYMBOL(dmu_write_policy);
2083 EXPORT_SYMBOL(dmu_sync);
2084 EXPORT_SYMBOL(dmu_request_arcbuf);
2085 EXPORT_SYMBOL(dmu_return_arcbuf);
2086 EXPORT_SYMBOL(dmu_assign_arcbuf);
2087 EXPORT_SYMBOL(dmu_buf_hold);
2088 EXPORT_SYMBOL(dmu_ot);
2090 module_param(zfs_mdcomp_disable, int, 0644);
2091 MODULE_PARM_DESC(zfs_mdcomp_disable, "Disable meta data compression");
2093 module_param(zfs_nopwrite_enabled, int, 0644);
2094 MODULE_PARM_DESC(zfs_nopwrite_enabled, "Enable NOP writes");