]> git.proxmox.com Git - mirror_zfs.git/blob - module/zfs/dmu.c
projects / mirror_zfs.git / blob
? search:
summary | shortlog | log | commit | commitdiff | tree
blame | history | raw | HEAD
Illumos #3086: unnecessarily setting DS_FLAG_INCONSISTENT on async
[mirror_zfs.git] / module / zfs / dmu.c
1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21 /*
22 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
23 * Copyright (c) 2012 by Delphix. All rights reserved.
24 */
25
26 #include <sys/dmu.h>
27 #include <sys/dmu_impl.h>
28 #include <sys/dmu_tx.h>
29 #include <sys/dbuf.h>
30 #include <sys/dnode.h>
31 #include <sys/zfs_context.h>
32 #include <sys/dmu_objset.h>
33 #include <sys/dmu_traverse.h>
34 #include <sys/dsl_dataset.h>
35 #include <sys/dsl_dir.h>
36 #include <sys/dsl_pool.h>
37 #include <sys/dsl_synctask.h>
38 #include <sys/dsl_prop.h>
39 #include <sys/dmu_zfetch.h>
40 #include <sys/zfs_ioctl.h>
41 #include <sys/zap.h>
42 #include <sys/zio_checksum.h>
43 #include <sys/sa.h>
44 #ifdef _KERNEL
45 #include <sys/vmsystm.h>
46 #include <sys/zfs_znode.h>
47 #endif
48
49 const dmu_object_type_info_t dmu_ot[DMU_OT_NUMTYPES] = {
50 { DMU_BSWAP_UINT8, TRUE, "unallocated" },
51 { DMU_BSWAP_ZAP, TRUE, "object directory" },
52 { DMU_BSWAP_UINT64, TRUE, "object array" },
53 { DMU_BSWAP_UINT8, TRUE, "packed nvlist" },
54 { DMU_BSWAP_UINT64, TRUE, "packed nvlist size" },
55 { DMU_BSWAP_UINT64, TRUE, "bpobj" },
56 { DMU_BSWAP_UINT64, TRUE, "bpobj header" },
57 { DMU_BSWAP_UINT64, TRUE, "SPA space map header" },
58 { DMU_BSWAP_UINT64, TRUE, "SPA space map" },
59 { DMU_BSWAP_UINT64, TRUE, "ZIL intent log" },
60 { DMU_BSWAP_DNODE, TRUE, "DMU dnode" },
61 { DMU_BSWAP_OBJSET, TRUE, "DMU objset" },
62 { DMU_BSWAP_UINT64, TRUE, "DSL directory" },
63 { DMU_BSWAP_ZAP, TRUE, "DSL directory child map"},
64 { DMU_BSWAP_ZAP, TRUE, "DSL dataset snap map" },
65 { DMU_BSWAP_ZAP, TRUE, "DSL props" },
66 { DMU_BSWAP_UINT64, TRUE, "DSL dataset" },
67 { DMU_BSWAP_ZNODE, TRUE, "ZFS znode" },
68 { DMU_BSWAP_OLDACL, TRUE, "ZFS V0 ACL" },
69 { DMU_BSWAP_UINT8, FALSE, "ZFS plain file" },
70 { DMU_BSWAP_ZAP, TRUE, "ZFS directory" },
71 { DMU_BSWAP_ZAP, TRUE, "ZFS master node" },
72 { DMU_BSWAP_ZAP, TRUE, "ZFS delete queue" },
73 { DMU_BSWAP_UINT8, FALSE, "zvol object" },
74 { DMU_BSWAP_ZAP, TRUE, "zvol prop" },
75 { DMU_BSWAP_UINT8, FALSE, "other uint8[]" },
76 { DMU_BSWAP_UINT64, FALSE, "other uint64[]" },
77 { DMU_BSWAP_ZAP, TRUE, "other ZAP" },
78 { DMU_BSWAP_ZAP, TRUE, "persistent error log" },
79 { DMU_BSWAP_UINT8, TRUE, "SPA history" },
80 { DMU_BSWAP_UINT64, TRUE, "SPA history offsets" },
81 { DMU_BSWAP_ZAP, TRUE, "Pool properties" },
82 { DMU_BSWAP_ZAP, TRUE, "DSL permissions" },
83 { DMU_BSWAP_ACL, TRUE, "ZFS ACL" },
84 { DMU_BSWAP_UINT8, TRUE, "ZFS SYSACL" },
85 { DMU_BSWAP_UINT8, TRUE, "FUID table" },
86 { DMU_BSWAP_UINT64, TRUE, "FUID table size" },
87 { DMU_BSWAP_ZAP, TRUE, "DSL dataset next clones"},
88 { DMU_BSWAP_ZAP, TRUE, "scan work queue" },
89 { DMU_BSWAP_ZAP, TRUE, "ZFS user/group used" },
90 { DMU_BSWAP_ZAP, TRUE, "ZFS user/group quota" },
91 { DMU_BSWAP_ZAP, TRUE, "snapshot refcount tags"},
92 { DMU_BSWAP_ZAP, TRUE, "DDT ZAP algorithm" },
93 { DMU_BSWAP_ZAP, TRUE, "DDT statistics" },
94 { DMU_BSWAP_UINT8, TRUE, "System attributes" },
95 { DMU_BSWAP_ZAP, TRUE, "SA master node" },
96 { DMU_BSWAP_ZAP, TRUE, "SA attr registration" },
97 { DMU_BSWAP_ZAP, TRUE, "SA attr layouts" },
98 { DMU_BSWAP_ZAP, TRUE, "scan translations" },
99 { DMU_BSWAP_UINT8, FALSE, "deduplicated block" },
100 { DMU_BSWAP_ZAP, TRUE, "DSL deadlist map" },
101 { DMU_BSWAP_UINT64, TRUE, "DSL deadlist map hdr" },
102 { DMU_BSWAP_ZAP, TRUE, "DSL dir clones" },
103 { DMU_BSWAP_UINT64, TRUE, "bpobj subobj" }
104 };
105
106 const dmu_object_byteswap_info_t dmu_ot_byteswap[DMU_BSWAP_NUMFUNCS] = {
107 { byteswap_uint8_array, "uint8" },
108 { byteswap_uint16_array, "uint16" },
109 { byteswap_uint32_array, "uint32" },
110 { byteswap_uint64_array, "uint64" },
111 { zap_byteswap, "zap" },
112 { dnode_buf_byteswap, "dnode" },
113 { dmu_objset_byteswap, "objset" },
114 { zfs_znode_byteswap, "znode" },
115 { zfs_oldacl_byteswap, "oldacl" },
116 { zfs_acl_byteswap, "acl" }
117 };
118
119 int
120 dmu_buf_hold(objset_t *os, uint64_t object, uint64_t offset,
121 void *tag, dmu_buf_t **dbp, int flags)
122 {
123 dnode_t *dn;
124 uint64_t blkid;
125 dmu_buf_impl_t *db;
126 int err;
127 int db_flags = DB_RF_CANFAIL;
128
129 if (flags & DMU_READ_NO_PREFETCH)
130 db_flags |= DB_RF_NOPREFETCH;
131
132 err = dnode_hold(os, object, FTAG, &dn);
133 if (err)
134 return (err);
135 blkid = dbuf_whichblock(dn, offset);
136 rw_enter(&dn->dn_struct_rwlock, RW_READER);
137 db = dbuf_hold(dn, blkid, tag);
138 rw_exit(&dn->dn_struct_rwlock);
139 if (db == NULL) {
140 err = EIO;
141 } else {
142 err = dbuf_read(db, NULL, db_flags);
143 if (err) {
144 dbuf_rele(db, tag);
145 db = NULL;
146 }
147 }
148
149 dnode_rele(dn, FTAG);
150 *dbp = &db->db; /* NULL db plus first field offset is NULL */
151 return (err);
152 }
153
154 int
155 dmu_bonus_max(void)
156 {
157 return (DN_MAX_BONUSLEN);
158 }
159
160 int
161 dmu_set_bonus(dmu_buf_t *db_fake, int newsize, dmu_tx_t *tx)
162 {
163 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
164 dnode_t *dn;
165 int error;
166
167 DB_DNODE_ENTER(db);
168 dn = DB_DNODE(db);
169
170 if (dn->dn_bonus != db) {
171 error = EINVAL;
172 } else if (newsize < 0 || newsize > db_fake->db_size) {
173 error = EINVAL;
174 } else {
175 dnode_setbonuslen(dn, newsize, tx);
176 error = 0;
177 }
178
179 DB_DNODE_EXIT(db);
180 return (error);
181 }
182
183 int
184 dmu_set_bonustype(dmu_buf_t *db_fake, dmu_object_type_t type, dmu_tx_t *tx)
185 {
186 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
187 dnode_t *dn;
188 int error;
189
190 DB_DNODE_ENTER(db);
191 dn = DB_DNODE(db);
192
193 if (!DMU_OT_IS_VALID(type)) {
194 error = EINVAL;
195 } else if (dn->dn_bonus != db) {
196 error = EINVAL;
197 } else {
198 dnode_setbonus_type(dn, type, tx);
199 error = 0;
200 }
201
202 DB_DNODE_EXIT(db);
203 return (error);
204 }
205
206 dmu_object_type_t
207 dmu_get_bonustype(dmu_buf_t *db_fake)
208 {
209 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
210 dnode_t *dn;
211 dmu_object_type_t type;
212
213 DB_DNODE_ENTER(db);
214 dn = DB_DNODE(db);
215 type = dn->dn_bonustype;
216 DB_DNODE_EXIT(db);
217
218 return (type);
219 }
220
221 int
222 dmu_rm_spill(objset_t *os, uint64_t object, dmu_tx_t *tx)
223 {
224 dnode_t *dn;
225 int error;
226
227 error = dnode_hold(os, object, FTAG, &dn);
228 dbuf_rm_spill(dn, tx);
229 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
230 dnode_rm_spill(dn, tx);
231 rw_exit(&dn->dn_struct_rwlock);
232 dnode_rele(dn, FTAG);
233 return (error);
234 }
235
236 /*
237 * returns ENOENT, EIO, or 0.
238 */
239 int
240 dmu_bonus_hold(objset_t *os, uint64_t object, void *tag, dmu_buf_t **dbp)
241 {
242 dnode_t *dn;
243 dmu_buf_impl_t *db;
244 int error;
245
246 error = dnode_hold(os, object, FTAG, &dn);
247 if (error)
248 return (error);
249
250 rw_enter(&dn->dn_struct_rwlock, RW_READER);
251 if (dn->dn_bonus == NULL) {
252 rw_exit(&dn->dn_struct_rwlock);
253 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
254 if (dn->dn_bonus == NULL)
255 dbuf_create_bonus(dn);
256 }
257 db = dn->dn_bonus;
258
259 /* as long as the bonus buf is held, the dnode will be held */
260 if (refcount_add(&db->db_holds, tag) == 1) {
261 VERIFY(dnode_add_ref(dn, db));
262 (void) atomic_inc_32_nv(&dn->dn_dbufs_count);
263 }
264
265 /*
266 * Wait to drop dn_struct_rwlock until after adding the bonus dbuf's
267 * hold and incrementing the dbuf count to ensure that dnode_move() sees
268 * a dnode hold for every dbuf.
269 */
270 rw_exit(&dn->dn_struct_rwlock);
271
272 dnode_rele(dn, FTAG);
273
274 VERIFY(0 == dbuf_read(db, NULL, DB_RF_MUST_SUCCEED | DB_RF_NOPREFETCH));
275
276 *dbp = &db->db;
277 return (0);
278 }
279
280 /*
281 * returns ENOENT, EIO, or 0.
282 *
283 * This interface will allocate a blank spill dbuf when a spill blk
284 * doesn't already exist on the dnode.
285 *
286 * if you only want to find an already existing spill db, then
287 * dmu_spill_hold_existing() should be used.
288 */
289 int
290 dmu_spill_hold_by_dnode(dnode_t *dn, uint32_t flags, void *tag, dmu_buf_t **dbp)
291 {
292 dmu_buf_impl_t *db = NULL;
293 int err;
294
295 if ((flags & DB_RF_HAVESTRUCT) == 0)
296 rw_enter(&dn->dn_struct_rwlock, RW_READER);
297
298 db = dbuf_hold(dn, DMU_SPILL_BLKID, tag);
299
300 if ((flags & DB_RF_HAVESTRUCT) == 0)
301 rw_exit(&dn->dn_struct_rwlock);
302
303 ASSERT(db != NULL);
304 err = dbuf_read(db, NULL, flags);
305 if (err == 0)
306 *dbp = &db->db;
307 else
308 dbuf_rele(db, tag);
309 return (err);
310 }
311
312 int
313 dmu_spill_hold_existing(dmu_buf_t *bonus, void *tag, dmu_buf_t **dbp)
314 {
315 dmu_buf_impl_t *db = (dmu_buf_impl_t *)bonus;
316 dnode_t *dn;
317 int err;
318
319 DB_DNODE_ENTER(db);
320 dn = DB_DNODE(db);
321
322 if (spa_version(dn->dn_objset->os_spa) < SPA_VERSION_SA) {
323 err = EINVAL;
324 } else {
325 rw_enter(&dn->dn_struct_rwlock, RW_READER);
326
327 if (!dn->dn_have_spill) {
328 err = ENOENT;
329 } else {
330 err = dmu_spill_hold_by_dnode(dn,
331 DB_RF_HAVESTRUCT | DB_RF_CANFAIL, tag, dbp);
332 }
333
334 rw_exit(&dn->dn_struct_rwlock);
335 }
336
337 DB_DNODE_EXIT(db);
338 return (err);
339 }
340
341 int
342 dmu_spill_hold_by_bonus(dmu_buf_t *bonus, void *tag, dmu_buf_t **dbp)
343 {
344 dmu_buf_impl_t *db = (dmu_buf_impl_t *)bonus;
345 dnode_t *dn;
346 int err;
347
348 DB_DNODE_ENTER(db);
349 dn = DB_DNODE(db);
350 err = dmu_spill_hold_by_dnode(dn, DB_RF_CANFAIL, tag, dbp);
351 DB_DNODE_EXIT(db);
352
353 return (err);
354 }
355
356 /*
357 * Note: longer-term, we should modify all of the dmu_buf_*() interfaces
358 * to take a held dnode rather than <os, object> -- the lookup is wasteful,
359 * and can induce severe lock contention when writing to several files
360 * whose dnodes are in the same block.
361 */
362 static int
363 dmu_buf_hold_array_by_dnode(dnode_t *dn, uint64_t offset, uint64_t length,
364 int read, void *tag, int *numbufsp, dmu_buf_t ***dbpp, uint32_t flags)
365 {
366 dsl_pool_t *dp = NULL;
367 dmu_buf_t **dbp;
368 uint64_t blkid, nblks, i;
369 uint32_t dbuf_flags;
370 int err;
371 zio_t *zio;
372 hrtime_t start = 0;
373
374 ASSERT(length <= DMU_MAX_ACCESS);
375
376 dbuf_flags = DB_RF_CANFAIL | DB_RF_NEVERWAIT | DB_RF_HAVESTRUCT;
377 if (flags & DMU_READ_NO_PREFETCH || length > zfetch_array_rd_sz)
378 dbuf_flags |= DB_RF_NOPREFETCH;
379
380 rw_enter(&dn->dn_struct_rwlock, RW_READER);
381 if (dn->dn_datablkshift) {
382 int blkshift = dn->dn_datablkshift;
383 nblks = (P2ROUNDUP(offset+length, 1ULL<<blkshift) -
384 P2ALIGN(offset, 1ULL<<blkshift)) >> blkshift;
385 } else {
386 if (offset + length > dn->dn_datablksz) {
387 zfs_panic_recover("zfs: accessing past end of object "
388 "%llx/%llx (size=%u access=%llu+%llu)",
389 (longlong_t)dn->dn_objset->
390 os_dsl_dataset->ds_object,
391 (longlong_t)dn->dn_object, dn->dn_datablksz,
392 (longlong_t)offset, (longlong_t)length);
393 rw_exit(&dn->dn_struct_rwlock);
394 return (EIO);
395 }
396 nblks = 1;
397 }
398 dbp = kmem_zalloc(sizeof (dmu_buf_t *) * nblks, KM_PUSHPAGE | KM_NODEBUG);
399
400 if (dn->dn_objset->os_dsl_dataset)
401 dp = dn->dn_objset->os_dsl_dataset->ds_dir->dd_pool;
402 if (dp && dsl_pool_sync_context(dp))
403 start = gethrtime();
404 zio = zio_root(dn->dn_objset->os_spa, NULL, NULL, ZIO_FLAG_CANFAIL);
405 blkid = dbuf_whichblock(dn, offset);
406 for (i = 0; i < nblks; i++) {
407 dmu_buf_impl_t *db = dbuf_hold(dn, blkid+i, tag);
408 if (db == NULL) {
409 rw_exit(&dn->dn_struct_rwlock);
410 dmu_buf_rele_array(dbp, nblks, tag);
411 zio_nowait(zio);
412 return (EIO);
413 }
414 /* initiate async i/o */
415 if (read) {
416 (void) dbuf_read(db, zio, dbuf_flags);
417 }
418 dbp[i] = &db->db;
419 }
420 rw_exit(&dn->dn_struct_rwlock);
421
422 /* wait for async i/o */
423 err = zio_wait(zio);
424 /* track read overhead when we are in sync context */
425 if (dp && dsl_pool_sync_context(dp))
426 dp->dp_read_overhead += gethrtime() - start;
427 if (err) {
428 dmu_buf_rele_array(dbp, nblks, tag);
429 return (err);
430 }
431
432 /* wait for other io to complete */
433 if (read) {
434 for (i = 0; i < nblks; i++) {
435 dmu_buf_impl_t *db = (dmu_buf_impl_t *)dbp[i];
436 mutex_enter(&db->db_mtx);
437 while (db->db_state == DB_READ ||
438 db->db_state == DB_FILL)
439 cv_wait(&db->db_changed, &db->db_mtx);
440 if (db->db_state == DB_UNCACHED)
441 err = EIO;
442 mutex_exit(&db->db_mtx);
443 if (err) {
444 dmu_buf_rele_array(dbp, nblks, tag);
445 return (err);
446 }
447 }
448 }
449
450 *numbufsp = nblks;
451 *dbpp = dbp;
452 return (0);
453 }
454
455 static int
456 dmu_buf_hold_array(objset_t *os, uint64_t object, uint64_t offset,
457 uint64_t length, int read, void *tag, int *numbufsp, dmu_buf_t ***dbpp)
458 {
459 dnode_t *dn;
460 int err;
461
462 err = dnode_hold(os, object, FTAG, &dn);
463 if (err)
464 return (err);
465
466 err = dmu_buf_hold_array_by_dnode(dn, offset, length, read, tag,
467 numbufsp, dbpp, DMU_READ_PREFETCH);
468
469 dnode_rele(dn, FTAG);
470
471 return (err);
472 }
473
474 int
475 dmu_buf_hold_array_by_bonus(dmu_buf_t *db_fake, uint64_t offset,
476 uint64_t length, int read, void *tag, int *numbufsp, dmu_buf_t ***dbpp)
477 {
478 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
479 dnode_t *dn;
480 int err;
481
482 DB_DNODE_ENTER(db);
483 dn = DB_DNODE(db);
484 err = dmu_buf_hold_array_by_dnode(dn, offset, length, read, tag,
485 numbufsp, dbpp, DMU_READ_PREFETCH);
486 DB_DNODE_EXIT(db);
487
488 return (err);
489 }
490
491 void
492 dmu_buf_rele_array(dmu_buf_t **dbp_fake, int numbufs, void *tag)
493 {
494 int i;
495 dmu_buf_impl_t **dbp = (dmu_buf_impl_t **)dbp_fake;
496
497 if (numbufs == 0)
498 return;
499
500 for (i = 0; i < numbufs; i++) {
501 if (dbp[i])
502 dbuf_rele(dbp[i], tag);
503 }
504
505 kmem_free(dbp, sizeof (dmu_buf_t *) * numbufs);
506 }
507
508 void
509 dmu_prefetch(objset_t *os, uint64_t object, uint64_t offset, uint64_t len)
510 {
511 dnode_t *dn;
512 uint64_t blkid;
513 int nblks, i, err;
514
515 if (zfs_prefetch_disable)
516 return;
517
518 if (len == 0) { /* they're interested in the bonus buffer */
519 dn = DMU_META_DNODE(os);
520
521 if (object == 0 || object >= DN_MAX_OBJECT)
522 return;
523
524 rw_enter(&dn->dn_struct_rwlock, RW_READER);
525 blkid = dbuf_whichblock(dn, object * sizeof (dnode_phys_t));
526 dbuf_prefetch(dn, blkid);
527 rw_exit(&dn->dn_struct_rwlock);
528 return;
529 }
530
531 /*
532 * XXX - Note, if the dnode for the requested object is not
533 * already cached, we will do a *synchronous* read in the
534 * dnode_hold() call. The same is true for any indirects.
535 */
536 err = dnode_hold(os, object, FTAG, &dn);
537 if (err != 0)
538 return;
539
540 rw_enter(&dn->dn_struct_rwlock, RW_READER);
541 if (dn->dn_datablkshift) {
542 int blkshift = dn->dn_datablkshift;
543 nblks = (P2ROUNDUP(offset+len, 1<<blkshift) -
544 P2ALIGN(offset, 1<<blkshift)) >> blkshift;
545 } else {
546 nblks = (offset < dn->dn_datablksz);
547 }
548
549 if (nblks != 0) {
550 blkid = dbuf_whichblock(dn, offset);
551 for (i = 0; i < nblks; i++)
552 dbuf_prefetch(dn, blkid+i);
553 }
554
555 rw_exit(&dn->dn_struct_rwlock);
556
557 dnode_rele(dn, FTAG);
558 }
559
560 /*
561 * Get the next "chunk" of file data to free. We traverse the file from
562 * the end so that the file gets shorter over time (if we crashes in the
563 * middle, this will leave us in a better state). We find allocated file
564 * data by simply searching the allocated level 1 indirects.
565 */
566 static int
567 get_next_chunk(dnode_t *dn, uint64_t *start, uint64_t limit)
568 {
569 uint64_t len = *start - limit;
570 uint64_t blkcnt = 0;
571 uint64_t maxblks = DMU_MAX_ACCESS / (1ULL << (dn->dn_indblkshift + 1));
572 uint64_t iblkrange =
573 dn->dn_datablksz * EPB(dn->dn_indblkshift, SPA_BLKPTRSHIFT);
574
575 ASSERT(limit <= *start);
576
577 if (len <= iblkrange * maxblks) {
578 *start = limit;
579 return (0);
580 }
581 ASSERT(ISP2(iblkrange));
582
583 while (*start > limit && blkcnt < maxblks) {
584 int err;
585
586 /* find next allocated L1 indirect */
587 err = dnode_next_offset(dn,
588 DNODE_FIND_BACKWARDS, start, 2, 1, 0);
589
590 /* if there are no more, then we are done */
591 if (err == ESRCH) {
592 *start = limit;
593 return (0);
594 } else if (err) {
595 return (err);
596 }
597 blkcnt += 1;
598
599 /* reset offset to end of "next" block back */
600 *start = P2ALIGN(*start, iblkrange);
601 if (*start <= limit)
602 *start = limit;
603 else
604 *start -= 1;
605 }
606 return (0);
607 }
608
609 static int
610 dmu_free_long_range_impl(objset_t *os, dnode_t *dn, uint64_t offset,
611 uint64_t length, boolean_t free_dnode)
612 {
613 dmu_tx_t *tx;
614 uint64_t object_size, start, end, len;
615 boolean_t trunc = (length == DMU_OBJECT_END);
616 int align, err;
617
618 align = 1 << dn->dn_datablkshift;
619 ASSERT(align > 0);
620 object_size = align == 1 ? dn->dn_datablksz :
621 (dn->dn_maxblkid + 1) << dn->dn_datablkshift;
622
623 end = offset + length;
624 if (trunc || end > object_size)
625 end = object_size;
626 if (end <= offset)
627 return (0);
628 length = end - offset;
629
630 while (length) {
631 start = end;
632 /* assert(offset <= start) */
633 err = get_next_chunk(dn, &start, offset);
634 if (err)
635 return (err);
636 len = trunc ? DMU_OBJECT_END : end - start;
637
638 tx = dmu_tx_create(os);
639 dmu_tx_hold_free(tx, dn->dn_object, start, len);
640 err = dmu_tx_assign(tx, TXG_WAIT);
641 if (err) {
642 dmu_tx_abort(tx);
643 return (err);
644 }
645
646 dnode_free_range(dn, start, trunc ? -1 : len, tx);
647
648 if (start == 0 && free_dnode) {
649 ASSERT(trunc);
650 dnode_free(dn, tx);
651 }
652
653 length -= end - start;
654
655 dmu_tx_commit(tx);
656 end = start;
657 }
658 return (0);
659 }
660
661 int
662 dmu_free_long_range(objset_t *os, uint64_t object,
663 uint64_t offset, uint64_t length)
664 {
665 dnode_t *dn;
666 int err;
667
668 err = dnode_hold(os, object, FTAG, &dn);
669 if (err != 0)
670 return (err);
671 err = dmu_free_long_range_impl(os, dn, offset, length, FALSE);
672 dnode_rele(dn, FTAG);
673 return (err);
674 }
675
676 int
677 dmu_free_object(objset_t *os, uint64_t object)
678 {
679 dnode_t *dn;
680 dmu_tx_t *tx;
681 int err;
682
683 err = dnode_hold_impl(os, object, DNODE_MUST_BE_ALLOCATED,
684 FTAG, &dn);
685 if (err != 0)
686 return (err);
687 if (dn->dn_nlevels == 1) {
688 tx = dmu_tx_create(os);
689 dmu_tx_hold_bonus(tx, object);
690 dmu_tx_hold_free(tx, dn->dn_object, 0, DMU_OBJECT_END);
691 err = dmu_tx_assign(tx, TXG_WAIT);
692 if (err == 0) {
693 dnode_free_range(dn, 0, DMU_OBJECT_END, tx);
694 dnode_free(dn, tx);
695 dmu_tx_commit(tx);
696 } else {
697 dmu_tx_abort(tx);
698 }
699 } else {
700 err = dmu_free_long_range_impl(os, dn, 0, DMU_OBJECT_END, TRUE);
701 }
702 dnode_rele(dn, FTAG);
703 return (err);
704 }
705
706 int
707 dmu_free_range(objset_t *os, uint64_t object, uint64_t offset,
708 uint64_t size, dmu_tx_t *tx)
709 {
710 dnode_t *dn;
711 int err = dnode_hold(os, object, FTAG, &dn);
712 if (err)
713 return (err);
714 ASSERT(offset < UINT64_MAX);
715 ASSERT(size == -1ULL || size <= UINT64_MAX - offset);
716 dnode_free_range(dn, offset, size, tx);
717 dnode_rele(dn, FTAG);
718 return (0);
719 }
720
721 int
722 dmu_read(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
723 void *buf, uint32_t flags)
724 {
725 dnode_t *dn;
726 dmu_buf_t **dbp;
727 int numbufs, err;
728
729 err = dnode_hold(os, object, FTAG, &dn);
730 if (err)
731 return (err);
732
733 /*
734 * Deal with odd block sizes, where there can't be data past the first
735 * block. If we ever do the tail block optimization, we will need to
736 * handle that here as well.
737 */
738 if (dn->dn_maxblkid == 0) {
739 int newsz = offset > dn->dn_datablksz ? 0 :
740 MIN(size, dn->dn_datablksz - offset);
741 bzero((char *)buf + newsz, size - newsz);
742 size = newsz;
743 }
744
745 while (size > 0) {
746 uint64_t mylen = MIN(size, DMU_MAX_ACCESS / 2);
747 int i;
748
749 /*
750 * NB: we could do this block-at-a-time, but it's nice
751 * to be reading in parallel.
752 */
753 err = dmu_buf_hold_array_by_dnode(dn, offset, mylen,
754 TRUE, FTAG, &numbufs, &dbp, flags);
755 if (err)
756 break;
757
758 for (i = 0; i < numbufs; i++) {
759 int tocpy;
760 int bufoff;
761 dmu_buf_t *db = dbp[i];
762
763 ASSERT(size > 0);
764
765 bufoff = offset - db->db_offset;
766 tocpy = (int)MIN(db->db_size - bufoff, size);
767
768 bcopy((char *)db->db_data + bufoff, buf, tocpy);
769
770 offset += tocpy;
771 size -= tocpy;
772 buf = (char *)buf + tocpy;
773 }
774 dmu_buf_rele_array(dbp, numbufs, FTAG);
775 }
776 dnode_rele(dn, FTAG);
777 return (err);
778 }
779
780 void
781 dmu_write(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
782 const void *buf, dmu_tx_t *tx)
783 {
784 dmu_buf_t **dbp;
785 int numbufs, i;
786
787 if (size == 0)
788 return;
789
790 VERIFY(0 == dmu_buf_hold_array(os, object, offset, size,
791 FALSE, FTAG, &numbufs, &dbp));
792
793 for (i = 0; i < numbufs; i++) {
794 int tocpy;
795 int bufoff;
796 dmu_buf_t *db = dbp[i];
797
798 ASSERT(size > 0);
799
800 bufoff = offset - db->db_offset;
801 tocpy = (int)MIN(db->db_size - bufoff, size);
802
803 ASSERT(i == 0 || i == numbufs-1 || tocpy == db->db_size);
804
805 if (tocpy == db->db_size)
806 dmu_buf_will_fill(db, tx);
807 else
808 dmu_buf_will_dirty(db, tx);
809
810 (void) memcpy((char *)db->db_data + bufoff, buf, tocpy);
811
812 if (tocpy == db->db_size)
813 dmu_buf_fill_done(db, tx);
814
815 offset += tocpy;
816 size -= tocpy;
817 buf = (char *)buf + tocpy;
818 }
819 dmu_buf_rele_array(dbp, numbufs, FTAG);
820 }
821
822 void
823 dmu_prealloc(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
824 dmu_tx_t *tx)
825 {
826 dmu_buf_t **dbp;
827 int numbufs, i;
828
829 if (size == 0)
830 return;
831
832 VERIFY(0 == dmu_buf_hold_array(os, object, offset, size,
833 FALSE, FTAG, &numbufs, &dbp));
834
835 for (i = 0; i < numbufs; i++) {
836 dmu_buf_t *db = dbp[i];
837
838 dmu_buf_will_not_fill(db, tx);
839 }
840 dmu_buf_rele_array(dbp, numbufs, FTAG);
841 }
842
843 /*
844 * DMU support for xuio
845 */
846 kstat_t *xuio_ksp = NULL;
847
848 typedef struct xuio_stats {
849 /* loaned yet not returned arc_buf */
850 kstat_named_t xuiostat_onloan_rbuf;
851 kstat_named_t xuiostat_onloan_wbuf;
852 /* whether a copy is made when loaning out a read buffer */
853 kstat_named_t xuiostat_rbuf_copied;
854 kstat_named_t xuiostat_rbuf_nocopy;
855 /* whether a copy is made when assigning a write buffer */
856 kstat_named_t xuiostat_wbuf_copied;
857 kstat_named_t xuiostat_wbuf_nocopy;
858 } xuio_stats_t;
859
860 static xuio_stats_t xuio_stats = {
861 { "onloan_read_buf", KSTAT_DATA_UINT64 },
862 { "onloan_write_buf", KSTAT_DATA_UINT64 },
863 { "read_buf_copied", KSTAT_DATA_UINT64 },
864 { "read_buf_nocopy", KSTAT_DATA_UINT64 },
865 { "write_buf_copied", KSTAT_DATA_UINT64 },
866 { "write_buf_nocopy", KSTAT_DATA_UINT64 }
867 };
868
869 #define XUIOSTAT_INCR(stat, val) \
870 atomic_add_64(&xuio_stats.stat.value.ui64, (val))
871 #define XUIOSTAT_BUMP(stat) XUIOSTAT_INCR(stat, 1)
872
873 int
874 dmu_xuio_init(xuio_t *xuio, int nblk)
875 {
876 dmu_xuio_t *priv;
877 uio_t *uio = &xuio->xu_uio;
878
879 uio->uio_iovcnt = nblk;
880 uio->uio_iov = kmem_zalloc(nblk * sizeof (iovec_t), KM_PUSHPAGE);
881
882 priv = kmem_zalloc(sizeof (dmu_xuio_t), KM_PUSHPAGE);
883 priv->cnt = nblk;
884 priv->bufs = kmem_zalloc(nblk * sizeof (arc_buf_t *), KM_PUSHPAGE);
885 priv->iovp = uio->uio_iov;
886 XUIO_XUZC_PRIV(xuio) = priv;
887
888 if (XUIO_XUZC_RW(xuio) == UIO_READ)
889 XUIOSTAT_INCR(xuiostat_onloan_rbuf, nblk);
890 else
891 XUIOSTAT_INCR(xuiostat_onloan_wbuf, nblk);
892
893 return (0);
894 }
895
896 void
897 dmu_xuio_fini(xuio_t *xuio)
898 {
899 dmu_xuio_t *priv = XUIO_XUZC_PRIV(xuio);
900 int nblk = priv->cnt;
901
902 kmem_free(priv->iovp, nblk * sizeof (iovec_t));
903 kmem_free(priv->bufs, nblk * sizeof (arc_buf_t *));
904 kmem_free(priv, sizeof (dmu_xuio_t));
905
906 if (XUIO_XUZC_RW(xuio) == UIO_READ)
907 XUIOSTAT_INCR(xuiostat_onloan_rbuf, -nblk);
908 else
909 XUIOSTAT_INCR(xuiostat_onloan_wbuf, -nblk);
910 }
911
912 /*
913 * Initialize iov[priv->next] and priv->bufs[priv->next] with { off, n, abuf }
914 * and increase priv->next by 1.
915 */
916 int
917 dmu_xuio_add(xuio_t *xuio, arc_buf_t *abuf, offset_t off, size_t n)
918 {
919 struct iovec *iov;
920 uio_t *uio = &xuio->xu_uio;
921 dmu_xuio_t *priv = XUIO_XUZC_PRIV(xuio);
922 int i = priv->next++;
923
924 ASSERT(i < priv->cnt);
925 ASSERT(off + n <= arc_buf_size(abuf));
926 iov = uio->uio_iov + i;
927 iov->iov_base = (char *)abuf->b_data + off;
928 iov->iov_len = n;
929 priv->bufs[i] = abuf;
930 return (0);
931 }
932
933 int
934 dmu_xuio_cnt(xuio_t *xuio)
935 {
936 dmu_xuio_t *priv = XUIO_XUZC_PRIV(xuio);
937 return (priv->cnt);
938 }
939
940 arc_buf_t *
941 dmu_xuio_arcbuf(xuio_t *xuio, int i)
942 {
943 dmu_xuio_t *priv = XUIO_XUZC_PRIV(xuio);
944
945 ASSERT(i < priv->cnt);
946 return (priv->bufs[i]);
947 }
948
949 void
950 dmu_xuio_clear(xuio_t *xuio, int i)
951 {
952 dmu_xuio_t *priv = XUIO_XUZC_PRIV(xuio);
953
954 ASSERT(i < priv->cnt);
955 priv->bufs[i] = NULL;
956 }
957
958 static void
959 xuio_stat_init(void)
960 {
961 xuio_ksp = kstat_create("zfs", 0, "xuio_stats", "misc",
962 KSTAT_TYPE_NAMED, sizeof (xuio_stats) / sizeof (kstat_named_t),
963 KSTAT_FLAG_VIRTUAL);
964 if (xuio_ksp != NULL) {
965 xuio_ksp->ks_data = &xuio_stats;
966 kstat_install(xuio_ksp);
967 }
968 }
969
970 static void
971 xuio_stat_fini(void)
972 {
973 if (xuio_ksp != NULL) {
974 kstat_delete(xuio_ksp);
975 xuio_ksp = NULL;
976 }
977 }
978
979 void
980 xuio_stat_wbuf_copied()
981 {
982 XUIOSTAT_BUMP(xuiostat_wbuf_copied);
983 }
984
985 void
986 xuio_stat_wbuf_nocopy()
987 {
988 XUIOSTAT_BUMP(xuiostat_wbuf_nocopy);
989 }
990
991 #ifdef _KERNEL
992
993 /*
994 * Copy up to size bytes between arg_buf and req based on the data direction
995 * described by the req. If an entire req's data cannot be transfered the
996 * req's is updated such that it's current index and bv offsets correctly
997 * reference any residual data which could not be copied. The return value
998 * is the number of bytes successfully copied to arg_buf.
999 */
1000 static int
1001 dmu_req_copy(void *arg_buf, int size, int *offset, struct request *req)
1002 {
1003 struct bio_vec *bv;
1004 struct req_iterator iter;
1005 char *bv_buf;
1006 int tocpy;
1007
1008 *offset = 0;
1009 rq_for_each_segment(bv, req, iter) {
1010
1011 /* Fully consumed the passed arg_buf */
1012 ASSERT3S(*offset, <=, size);
1013 if (size == *offset)
1014 break;
1015
1016 /* Skip fully consumed bv's */
1017 if (bv->bv_len == 0)
1018 continue;
1019
1020 tocpy = MIN(bv->bv_len, size - *offset);
1021 ASSERT3S(tocpy, >=, 0);
1022
1023 bv_buf = page_address(bv->bv_page) + bv->bv_offset;
1024 ASSERT3P(bv_buf, !=, NULL);
1025
1026 if (rq_data_dir(req) == WRITE)
1027 memcpy(arg_buf + *offset, bv_buf, tocpy);
1028 else
1029 memcpy(bv_buf, arg_buf + *offset, tocpy);
1030
1031 *offset += tocpy;
1032 bv->bv_offset += tocpy;
1033 bv->bv_len -= tocpy;
1034 }
1035
1036 return 0;
1037 }
1038
1039 static void
1040 dmu_bio_put(struct bio *bio)
1041 {
1042 struct bio *bio_next;
1043
1044 while (bio) {
1045 bio_next = bio->bi_next;
1046 bio_put(bio);
1047 bio = bio_next;
1048 }
1049 }
1050
1051 static int
1052 dmu_bio_clone(struct bio *bio, struct bio **bio_copy)
1053 {
1054 struct bio *bio_root = NULL;
1055 struct bio *bio_last = NULL;
1056 struct bio *bio_new;
1057
1058 if (bio == NULL)
1059 return EINVAL;
1060
1061 while (bio) {
1062 bio_new = bio_clone(bio, GFP_NOIO);
1063 if (bio_new == NULL) {
1064 dmu_bio_put(bio_root);
1065 return ENOMEM;
1066 }
1067
1068 if (bio_last) {
1069 bio_last->bi_next = bio_new;
1070 bio_last = bio_new;
1071 } else {
1072 bio_root = bio_new;
1073 bio_last = bio_new;
1074 }
1075
1076 bio = bio->bi_next;
1077 }
1078
1079 *bio_copy = bio_root;
1080
1081 return 0;
1082 }
1083
1084 int
1085 dmu_read_req(objset_t *os, uint64_t object, struct request *req)
1086 {
1087 uint64_t size = blk_rq_bytes(req);
1088 uint64_t offset = blk_rq_pos(req) << 9;
1089 struct bio *bio_saved = req->bio;
1090 dmu_buf_t **dbp;
1091 int numbufs, i, err;
1092
1093 /*
1094 * NB: we could do this block-at-a-time, but it's nice
1095 * to be reading in parallel.
1096 */
1097 err = dmu_buf_hold_array(os, object, offset, size, TRUE, FTAG,
1098 &numbufs, &dbp);
1099 if (err)
1100 return (err);
1101
1102 /*
1103 * Clone the bio list so the bv->bv_offset and bv->bv_len members
1104 * can be safely modified. The original bio list is relinked in to
1105 * the request when the function exits. This is required because
1106 * some file systems blindly assume that these values will remain
1107 * constant between bio_submit() and the IO completion callback.
1108 */
1109 err = dmu_bio_clone(bio_saved, &req->bio);
1110 if (err)
1111 goto error;
1112
1113 for (i = 0; i < numbufs; i++) {
1114 int tocpy, didcpy, bufoff;
1115 dmu_buf_t *db = dbp[i];
1116
1117 bufoff = offset - db->db_offset;
1118 ASSERT3S(bufoff, >=, 0);
1119
1120 tocpy = (int)MIN(db->db_size - bufoff, size);
1121 if (tocpy == 0)
1122 break;
1123
1124 err = dmu_req_copy(db->db_data + bufoff, tocpy, &didcpy, req);
1125
1126 if (didcpy < tocpy)
1127 err = EIO;
1128
1129 if (err)
1130 break;
1131
1132 size -= tocpy;
1133 offset += didcpy;
1134 err = 0;
1135 }
1136
1137 dmu_bio_put(req->bio);
1138 req->bio = bio_saved;
1139 error:
1140 dmu_buf_rele_array(dbp, numbufs, FTAG);
1141
1142 return (err);
1143 }
1144
1145 int
1146 dmu_write_req(objset_t *os, uint64_t object, struct request *req, dmu_tx_t *tx)
1147 {
1148 uint64_t size = blk_rq_bytes(req);
1149 uint64_t offset = blk_rq_pos(req) << 9;
1150 struct bio *bio_saved = req->bio;
1151 dmu_buf_t **dbp;
1152 int numbufs;
1153 int err = 0;
1154 int i;
1155
1156 if (size == 0)
1157 return (0);
1158
1159 err = dmu_buf_hold_array(os, object, offset, size, FALSE, FTAG,
1160 &numbufs, &dbp);
1161 if (err)
1162 return (err);
1163
1164 /*
1165 * Clone the bio list so the bv->bv_offset and bv->bv_len members
1166 * can be safely modified. The original bio list is relinked in to
1167 * the request when the function exits. This is required because
1168 * some file systems blindly assume that these values will remain
1169 * constant between bio_submit() and the IO completion callback.
1170 */
1171 err = dmu_bio_clone(bio_saved, &req->bio);
1172 if (err)
1173 goto error;
1174
1175 for (i = 0; i < numbufs; i++) {
1176 int tocpy, didcpy, bufoff;
1177 dmu_buf_t *db = dbp[i];
1178
1179 bufoff = offset - db->db_offset;
1180 ASSERT3S(bufoff, >=, 0);
1181
1182 tocpy = (int)MIN(db->db_size - bufoff, size);
1183 if (tocpy == 0)
1184 break;
1185
1186 ASSERT(i == 0 || i == numbufs-1 || tocpy == db->db_size);
1187
1188 if (tocpy == db->db_size)
1189 dmu_buf_will_fill(db, tx);
1190 else
1191 dmu_buf_will_dirty(db, tx);
1192
1193 err = dmu_req_copy(db->db_data + bufoff, tocpy, &didcpy, req);
1194
1195 if (tocpy == db->db_size)
1196 dmu_buf_fill_done(db, tx);
1197
1198 if (didcpy < tocpy)
1199 err = EIO;
1200
1201 if (err)
1202 break;
1203
1204 size -= tocpy;
1205 offset += didcpy;
1206 err = 0;
1207 }
1208
1209 dmu_bio_put(req->bio);
1210 req->bio = bio_saved;
1211 error:
1212 dmu_buf_rele_array(dbp, numbufs, FTAG);
1213
1214 return (err);
1215 }
1216
1217 int
1218 dmu_read_uio(objset_t *os, uint64_t object, uio_t *uio, uint64_t size)
1219 {
1220 dmu_buf_t **dbp;
1221 int numbufs, i, err;
1222 xuio_t *xuio = NULL;
1223
1224 /*
1225 * NB: we could do this block-at-a-time, but it's nice
1226 * to be reading in parallel.
1227 */
1228 err = dmu_buf_hold_array(os, object, uio->uio_loffset, size, TRUE, FTAG,
1229 &numbufs, &dbp);
1230 if (err)
1231 return (err);
1232
1233 for (i = 0; i < numbufs; i++) {
1234 int tocpy;
1235 int bufoff;
1236 dmu_buf_t *db = dbp[i];
1237
1238 ASSERT(size > 0);
1239
1240 bufoff = uio->uio_loffset - db->db_offset;
1241 tocpy = (int)MIN(db->db_size - bufoff, size);
1242
1243 if (xuio) {
1244 dmu_buf_impl_t *dbi = (dmu_buf_impl_t *)db;
1245 arc_buf_t *dbuf_abuf = dbi->db_buf;
1246 arc_buf_t *abuf = dbuf_loan_arcbuf(dbi);
1247 err = dmu_xuio_add(xuio, abuf, bufoff, tocpy);
1248 if (!err) {
1249 uio->uio_resid -= tocpy;
1250 uio->uio_loffset += tocpy;
1251 }
1252
1253 if (abuf == dbuf_abuf)
1254 XUIOSTAT_BUMP(xuiostat_rbuf_nocopy);
1255 else
1256 XUIOSTAT_BUMP(xuiostat_rbuf_copied);
1257 } else {
1258 err = uiomove((char *)db->db_data + bufoff, tocpy,
1259 UIO_READ, uio);
1260 }
1261 if (err)
1262 break;
1263
1264 size -= tocpy;
1265 }
1266 dmu_buf_rele_array(dbp, numbufs, FTAG);
1267
1268 return (err);
1269 }
1270
1271 static int
1272 dmu_write_uio_dnode(dnode_t *dn, uio_t *uio, uint64_t size, dmu_tx_t *tx)
1273 {
1274 dmu_buf_t **dbp;
1275 int numbufs;
1276 int err = 0;
1277 int i;
1278
1279 err = dmu_buf_hold_array_by_dnode(dn, uio->uio_loffset, size,
1280 FALSE, FTAG, &numbufs, &dbp, DMU_READ_PREFETCH);
1281 if (err)
1282 return (err);
1283
1284 for (i = 0; i < numbufs; i++) {
1285 int tocpy;
1286 int bufoff;
1287 dmu_buf_t *db = dbp[i];
1288
1289 ASSERT(size > 0);
1290
1291 bufoff = uio->uio_loffset - db->db_offset;
1292 tocpy = (int)MIN(db->db_size - bufoff, size);
1293
1294 ASSERT(i == 0 || i == numbufs-1 || tocpy == db->db_size);
1295
1296 if (tocpy == db->db_size)
1297 dmu_buf_will_fill(db, tx);
1298 else
1299 dmu_buf_will_dirty(db, tx);
1300
1301 /*
1302 * XXX uiomove could block forever (eg.nfs-backed
1303 * pages). There needs to be a uiolockdown() function
1304 * to lock the pages in memory, so that uiomove won't
1305 * block.
1306 */
1307 err = uiomove((char *)db->db_data + bufoff, tocpy,
1308 UIO_WRITE, uio);
1309
1310 if (tocpy == db->db_size)
1311 dmu_buf_fill_done(db, tx);
1312
1313 if (err)
1314 break;
1315
1316 size -= tocpy;
1317 }
1318
1319 dmu_buf_rele_array(dbp, numbufs, FTAG);
1320 return (err);
1321 }
1322
1323 int
1324 dmu_write_uio_dbuf(dmu_buf_t *zdb, uio_t *uio, uint64_t size,
1325 dmu_tx_t *tx)
1326 {
1327 dmu_buf_impl_t *db = (dmu_buf_impl_t *)zdb;
1328 dnode_t *dn;
1329 int err;
1330
1331 if (size == 0)
1332 return (0);
1333
1334 DB_DNODE_ENTER(db);
1335 dn = DB_DNODE(db);
1336 err = dmu_write_uio_dnode(dn, uio, size, tx);
1337 DB_DNODE_EXIT(db);
1338
1339 return (err);
1340 }
1341
1342 int
1343 dmu_write_uio(objset_t *os, uint64_t object, uio_t *uio, uint64_t size,
1344 dmu_tx_t *tx)
1345 {
1346 dnode_t *dn;
1347 int err;
1348
1349 if (size == 0)
1350 return (0);
1351
1352 err = dnode_hold(os, object, FTAG, &dn);
1353 if (err)
1354 return (err);
1355
1356 err = dmu_write_uio_dnode(dn, uio, size, tx);
1357
1358 dnode_rele(dn, FTAG);
1359
1360 return (err);
1361 }
1362 #endif /* _KERNEL */
1363
1364 /*
1365 * Allocate a loaned anonymous arc buffer.
1366 */
1367 arc_buf_t *
1368 dmu_request_arcbuf(dmu_buf_t *handle, int size)
1369 {
1370 dmu_buf_impl_t *db = (dmu_buf_impl_t *)handle;
1371 spa_t *spa;
1372
1373 DB_GET_SPA(&spa, db);
1374 return (arc_loan_buf(spa, size));
1375 }
1376
1377 /*
1378 * Free a loaned arc buffer.
1379 */
1380 void
1381 dmu_return_arcbuf(arc_buf_t *buf)
1382 {
1383 arc_return_buf(buf, FTAG);
1384 VERIFY(arc_buf_remove_ref(buf, FTAG) == 1);
1385 }
1386
1387 /*
1388 * When possible directly assign passed loaned arc buffer to a dbuf.
1389 * If this is not possible copy the contents of passed arc buf via
1390 * dmu_write().
1391 */
1392 void
1393 dmu_assign_arcbuf(dmu_buf_t *handle, uint64_t offset, arc_buf_t *buf,
1394 dmu_tx_t *tx)
1395 {
1396 dmu_buf_impl_t *dbuf = (dmu_buf_impl_t *)handle;
1397 dnode_t *dn;
1398 dmu_buf_impl_t *db;
1399 uint32_t blksz = (uint32_t)arc_buf_size(buf);
1400 uint64_t blkid;
1401
1402 DB_DNODE_ENTER(dbuf);
1403 dn = DB_DNODE(dbuf);
1404 rw_enter(&dn->dn_struct_rwlock, RW_READER);
1405 blkid = dbuf_whichblock(dn, offset);
1406 VERIFY((db = dbuf_hold(dn, blkid, FTAG)) != NULL);
1407 rw_exit(&dn->dn_struct_rwlock);
1408 DB_DNODE_EXIT(dbuf);
1409
1410 if (offset == db->db.db_offset && blksz == db->db.db_size) {
1411 dbuf_assign_arcbuf(db, buf, tx);
1412 dbuf_rele(db, FTAG);
1413 } else {
1414 objset_t *os;
1415 uint64_t object;
1416
1417 DB_DNODE_ENTER(dbuf);
1418 dn = DB_DNODE(dbuf);
1419 os = dn->dn_objset;
1420 object = dn->dn_object;
1421 DB_DNODE_EXIT(dbuf);
1422
1423 dbuf_rele(db, FTAG);
1424 dmu_write(os, object, offset, blksz, buf->b_data, tx);
1425 dmu_return_arcbuf(buf);
1426 XUIOSTAT_BUMP(xuiostat_wbuf_copied);
1427 }
1428 }
1429
1430 typedef struct {
1431 dbuf_dirty_record_t *dsa_dr;
1432 dmu_sync_cb_t *dsa_done;
1433 zgd_t *dsa_zgd;
1434 dmu_tx_t *dsa_tx;
1435 } dmu_sync_arg_t;
1436
1437 /* ARGSUSED */
1438 static void
1439 dmu_sync_ready(zio_t *zio, arc_buf_t *buf, void *varg)
1440 {
1441 dmu_sync_arg_t *dsa = varg;
1442 dmu_buf_t *db = dsa->dsa_zgd->zgd_db;
1443 blkptr_t *bp = zio->io_bp;
1444
1445 if (zio->io_error == 0) {
1446 if (BP_IS_HOLE(bp)) {
1447 /*
1448 * A block of zeros may compress to a hole, but the
1449 * block size still needs to be known for replay.
1450 */
1451 BP_SET_LSIZE(bp, db->db_size);
1452 } else {
1453 ASSERT(BP_GET_LEVEL(bp) == 0);
1454 bp->blk_fill = 1;
1455 }
1456 }
1457 }
1458
1459 static void
1460 dmu_sync_late_arrival_ready(zio_t *zio)
1461 {
1462 dmu_sync_ready(zio, NULL, zio->io_private);
1463 }
1464
1465 /* ARGSUSED */
1466 static void
1467 dmu_sync_done(zio_t *zio, arc_buf_t *buf, void *varg)
1468 {
1469 dmu_sync_arg_t *dsa = varg;
1470 dbuf_dirty_record_t *dr = dsa->dsa_dr;
1471 dmu_buf_impl_t *db = dr->dr_dbuf;
1472
1473 mutex_enter(&db->db_mtx);
1474 ASSERT(dr->dt.dl.dr_override_state == DR_IN_DMU_SYNC);
1475 if (zio->io_error == 0) {
1476 dr->dt.dl.dr_overridden_by = *zio->io_bp;
1477 dr->dt.dl.dr_override_state = DR_OVERRIDDEN;
1478 dr->dt.dl.dr_copies = zio->io_prop.zp_copies;
1479 if (BP_IS_HOLE(&dr->dt.dl.dr_overridden_by))
1480 BP_ZERO(&dr->dt.dl.dr_overridden_by);
1481 } else {
1482 dr->dt.dl.dr_override_state = DR_NOT_OVERRIDDEN;
1483 }
1484 cv_broadcast(&db->db_changed);
1485 mutex_exit(&db->db_mtx);
1486
1487 dsa->dsa_done(dsa->dsa_zgd, zio->io_error);
1488
1489 kmem_free(dsa, sizeof (*dsa));
1490 }
1491
1492 static void
1493 dmu_sync_late_arrival_done(zio_t *zio)
1494 {
1495 blkptr_t *bp = zio->io_bp;
1496 dmu_sync_arg_t *dsa = zio->io_private;
1497
1498 if (zio->io_error == 0 && !BP_IS_HOLE(bp)) {
1499 ASSERT(zio->io_bp->blk_birth == zio->io_txg);
1500 ASSERT(zio->io_txg > spa_syncing_txg(zio->io_spa));
1501 zio_free(zio->io_spa, zio->io_txg, zio->io_bp);
1502 }
1503
1504 dmu_tx_commit(dsa->dsa_tx);
1505
1506 dsa->dsa_done(dsa->dsa_zgd, zio->io_error);
1507
1508 kmem_free(dsa, sizeof (*dsa));
1509 }
1510
1511 static int
1512 dmu_sync_late_arrival(zio_t *pio, objset_t *os, dmu_sync_cb_t *done, zgd_t *zgd,
1513 zio_prop_t *zp, zbookmark_t *zb)
1514 {
1515 dmu_sync_arg_t *dsa;
1516 dmu_tx_t *tx;
1517
1518 tx = dmu_tx_create(os);
1519 dmu_tx_hold_space(tx, zgd->zgd_db->db_size);
1520 if (dmu_tx_assign(tx, TXG_WAIT) != 0) {
1521 dmu_tx_abort(tx);
1522 return (EIO); /* Make zl_get_data do txg_waited_synced() */
1523 }
1524
1525 dsa = kmem_alloc(sizeof (dmu_sync_arg_t), KM_PUSHPAGE);
1526 dsa->dsa_dr = NULL;
1527 dsa->dsa_done = done;
1528 dsa->dsa_zgd = zgd;
1529 dsa->dsa_tx = tx;
1530
1531 zio_nowait(zio_write(pio, os->os_spa, dmu_tx_get_txg(tx), zgd->zgd_bp,
1532 zgd->zgd_db->db_data, zgd->zgd_db->db_size, zp,
1533 dmu_sync_late_arrival_ready, dmu_sync_late_arrival_done, dsa,
1534 ZIO_PRIORITY_SYNC_WRITE, ZIO_FLAG_CANFAIL | ZIO_FLAG_FASTWRITE, zb));
1535
1536 return (0);
1537 }
1538
1539 /*
1540 * Intent log support: sync the block associated with db to disk.
1541 * N.B. and XXX: the caller is responsible for making sure that the
1542 * data isn't changing while dmu_sync() is writing it.
1543 *
1544 * Return values:
1545 *
1546 * EEXIST: this txg has already been synced, so there's nothing to to.
1547 * The caller should not log the write.
1548 *
1549 * ENOENT: the block was dbuf_free_range()'d, so there's nothing to do.
1550 * The caller should not log the write.
1551 *
1552 * EALREADY: this block is already in the process of being synced.
1553 * The caller should track its progress (somehow).
1554 *
1555 * EIO: could not do the I/O.
1556 * The caller should do a txg_wait_synced().
1557 *
1558 * 0: the I/O has been initiated.
1559 * The caller should log this blkptr in the done callback.
1560 * It is possible that the I/O will fail, in which case
1561 * the error will be reported to the done callback and
1562 * propagated to pio from zio_done().
1563 */
1564 int
1565 dmu_sync(zio_t *pio, uint64_t txg, dmu_sync_cb_t *done, zgd_t *zgd)
1566 {
1567 blkptr_t *bp = zgd->zgd_bp;
1568 dmu_buf_impl_t *db = (dmu_buf_impl_t *)zgd->zgd_db;
1569 objset_t *os = db->db_objset;
1570 dsl_dataset_t *ds = os->os_dsl_dataset;
1571 dbuf_dirty_record_t *dr;
1572 dmu_sync_arg_t *dsa;
1573 zbookmark_t zb;
1574 zio_prop_t zp;
1575 dnode_t *dn;
1576
1577 ASSERT(pio != NULL);
1578 ASSERT(BP_IS_HOLE(bp));
1579 ASSERT(txg != 0);
1580
1581 SET_BOOKMARK(&zb, ds->ds_object,
1582 db->db.db_object, db->db_level, db->db_blkid);
1583
1584 DB_DNODE_ENTER(db);
1585 dn = DB_DNODE(db);
1586 dmu_write_policy(os, dn, db->db_level, WP_DMU_SYNC, &zp);
1587 DB_DNODE_EXIT(db);
1588
1589 /*
1590 * If we're frozen (running ziltest), we always need to generate a bp.
1591 */
1592 if (txg > spa_freeze_txg(os->os_spa))
1593 return (dmu_sync_late_arrival(pio, os, done, zgd, &zp, &zb));
1594
1595 /*
1596 * Grabbing db_mtx now provides a barrier between dbuf_sync_leaf()
1597 * and us. If we determine that this txg is not yet syncing,
1598 * but it begins to sync a moment later, that's OK because the
1599 * sync thread will block in dbuf_sync_leaf() until we drop db_mtx.
1600 */
1601 mutex_enter(&db->db_mtx);
1602
1603 if (txg <= spa_last_synced_txg(os->os_spa)) {
1604 /*
1605 * This txg has already synced. There's nothing to do.
1606 */
1607 mutex_exit(&db->db_mtx);
1608 return (EEXIST);
1609 }
1610
1611 if (txg <= spa_syncing_txg(os->os_spa)) {
1612 /*
1613 * This txg is currently syncing, so we can't mess with
1614 * the dirty record anymore; just write a new log block.
1615 */
1616 mutex_exit(&db->db_mtx);
1617 return (dmu_sync_late_arrival(pio, os, done, zgd, &zp, &zb));
1618 }
1619
1620 dr = db->db_last_dirty;
1621 while (dr && dr->dr_txg != txg)
1622 dr = dr->dr_next;
1623
1624 if (dr == NULL) {
1625 /*
1626 * There's no dr for this dbuf, so it must have been freed.
1627 * There's no need to log writes to freed blocks, so we're done.
1628 */
1629 mutex_exit(&db->db_mtx);
1630 return (ENOENT);
1631 }
1632
1633 ASSERT(dr->dr_txg == txg);
1634 if (dr->dt.dl.dr_override_state == DR_IN_DMU_SYNC ||
1635 dr->dt.dl.dr_override_state == DR_OVERRIDDEN) {
1636 /*
1637 * We have already issued a sync write for this buffer,
1638 * or this buffer has already been synced. It could not
1639 * have been dirtied since, or we would have cleared the state.
1640 */
1641 mutex_exit(&db->db_mtx);
1642 return (EALREADY);
1643 }
1644
1645 ASSERT(dr->dt.dl.dr_override_state == DR_NOT_OVERRIDDEN);
1646 dr->dt.dl.dr_override_state = DR_IN_DMU_SYNC;
1647 mutex_exit(&db->db_mtx);
1648
1649 dsa = kmem_alloc(sizeof (dmu_sync_arg_t), KM_PUSHPAGE);
1650 dsa->dsa_dr = dr;
1651 dsa->dsa_done = done;
1652 dsa->dsa_zgd = zgd;
1653 dsa->dsa_tx = NULL;
1654
1655 zio_nowait(arc_write(pio, os->os_spa, txg,
1656 bp, dr->dt.dl.dr_data, DBUF_IS_L2CACHEABLE(db), &zp,
1657 dmu_sync_ready, dmu_sync_done, dsa,
1658 ZIO_PRIORITY_SYNC_WRITE, ZIO_FLAG_CANFAIL | ZIO_FLAG_FASTWRITE, &zb));
1659
1660 return (0);
1661 }
1662
1663 int
1664 dmu_object_set_blocksize(objset_t *os, uint64_t object, uint64_t size, int ibs,
1665 dmu_tx_t *tx)
1666 {
1667 dnode_t *dn;
1668 int err;
1669
1670 err = dnode_hold(os, object, FTAG, &dn);
1671 if (err)
1672 return (err);
1673 err = dnode_set_blksz(dn, size, ibs, tx);
1674 dnode_rele(dn, FTAG);
1675 return (err);
1676 }
1677
1678 void
1679 dmu_object_set_checksum(objset_t *os, uint64_t object, uint8_t checksum,
1680 dmu_tx_t *tx)
1681 {
1682 dnode_t *dn;
1683
1684 /* XXX assumes dnode_hold will not get an i/o error */
1685 (void) dnode_hold(os, object, FTAG, &dn);
1686 ASSERT(checksum < ZIO_CHECKSUM_FUNCTIONS);
1687 dn->dn_checksum = checksum;
1688 dnode_setdirty(dn, tx);
1689 dnode_rele(dn, FTAG);
1690 }
1691
1692 void
1693 dmu_object_set_compress(objset_t *os, uint64_t object, uint8_t compress,
1694 dmu_tx_t *tx)
1695 {
1696 dnode_t *dn;
1697
1698 /* XXX assumes dnode_hold will not get an i/o error */
1699 (void) dnode_hold(os, object, FTAG, &dn);
1700 ASSERT(compress < ZIO_COMPRESS_FUNCTIONS);
1701 dn->dn_compress = compress;
1702 dnode_setdirty(dn, tx);
1703 dnode_rele(dn, FTAG);
1704 }
1705
1706 int zfs_mdcomp_disable = 0;
1707
1708 void
1709 dmu_write_policy(objset_t *os, dnode_t *dn, int level, int wp, zio_prop_t *zp)
1710 {
1711 dmu_object_type_t type = dn ? dn->dn_type : DMU_OT_OBJSET;
1712 boolean_t ismd = (level > 0 || DMU_OT_IS_METADATA(type) ||
1713 (wp & WP_SPILL));
1714 enum zio_checksum checksum = os->os_checksum;
1715 enum zio_compress compress = os->os_compress;
1716 enum zio_checksum dedup_checksum = os->os_dedup_checksum;
1717 boolean_t dedup;
1718 boolean_t dedup_verify = os->os_dedup_verify;
1719 int copies = os->os_copies;
1720
1721 /*
1722 * Determine checksum setting.
1723 */
1724 if (ismd) {
1725 /*
1726 * Metadata always gets checksummed. If the data
1727 * checksum is multi-bit correctable, and it's not a
1728 * ZBT-style checksum, then it's suitable for metadata
1729 * as well. Otherwise, the metadata checksum defaults
1730 * to fletcher4.
1731 */
1732 if (zio_checksum_table[checksum].ci_correctable < 1 ||
1733 zio_checksum_table[checksum].ci_eck)
1734 checksum = ZIO_CHECKSUM_FLETCHER_4;
1735 } else {
1736 checksum = zio_checksum_select(dn->dn_checksum, checksum);
1737 }
1738
1739 /*
1740 * Determine compression setting.
1741 */
1742 if (ismd) {
1743 /*
1744 * XXX -- we should design a compression algorithm
1745 * that specializes in arrays of bps.
1746 */
1747 compress = zfs_mdcomp_disable ? ZIO_COMPRESS_EMPTY :
1748 ZIO_COMPRESS_LZJB;
1749 } else {
1750 compress = zio_compress_select(dn->dn_compress, compress);
1751 }
1752
1753 /*
1754 * Determine dedup setting. If we are in dmu_sync(), we won't
1755 * actually dedup now because that's all done in syncing context;
1756 * but we do want to use the dedup checkum. If the checksum is not
1757 * strong enough to ensure unique signatures, force dedup_verify.
1758 */
1759 dedup = (!ismd && dedup_checksum != ZIO_CHECKSUM_OFF);
1760 if (dedup) {
1761 checksum = dedup_checksum;
1762 if (!zio_checksum_table[checksum].ci_dedup)
1763 dedup_verify = 1;
1764 }
1765
1766 if (wp & WP_DMU_SYNC)
1767 dedup = 0;
1768
1769 if (wp & WP_NOFILL) {
1770 ASSERT(!ismd && level == 0);
1771 checksum = ZIO_CHECKSUM_OFF;
1772 compress = ZIO_COMPRESS_OFF;
1773 dedup = B_FALSE;
1774 }
1775
1776 zp->zp_checksum = checksum;
1777 zp->zp_compress = compress;
1778 zp->zp_type = (wp & WP_SPILL) ? dn->dn_bonustype : type;
1779 zp->zp_level = level;
1780 zp->zp_copies = MIN(copies + ismd, spa_max_replication(os->os_spa));
1781 zp->zp_dedup = dedup;
1782 zp->zp_dedup_verify = dedup && dedup_verify;
1783 }
1784
1785 int
1786 dmu_offset_next(objset_t *os, uint64_t object, boolean_t hole, uint64_t *off)
1787 {
1788 dnode_t *dn;
1789 int i, err;
1790
1791 err = dnode_hold(os, object, FTAG, &dn);
1792 if (err)
1793 return (err);
1794 /*
1795 * Sync any current changes before
1796 * we go trundling through the block pointers.
1797 */
1798 for (i = 0; i < TXG_SIZE; i++) {
1799 if (list_link_active(&dn->dn_dirty_link[i]))
1800 break;
1801 }
1802 if (i != TXG_SIZE) {
1803 dnode_rele(dn, FTAG);
1804 txg_wait_synced(dmu_objset_pool(os), 0);
1805 err = dnode_hold(os, object, FTAG, &dn);
1806 if (err)
1807 return (err);
1808 }
1809
1810 err = dnode_next_offset(dn, (hole ? DNODE_FIND_HOLE : 0), off, 1, 1, 0);
1811 dnode_rele(dn, FTAG);
1812
1813 return (err);
1814 }
1815
1816 void
1817 dmu_object_info_from_dnode(dnode_t *dn, dmu_object_info_t *doi)
1818 {
1819 dnode_phys_t *dnp;
1820 int i;
1821
1822 rw_enter(&dn->dn_struct_rwlock, RW_READER);
1823 mutex_enter(&dn->dn_mtx);
1824
1825 dnp = dn->dn_phys;
1826
1827 doi->doi_data_block_size = dn->dn_datablksz;
1828 doi->doi_metadata_block_size = dn->dn_indblkshift ?
1829 1ULL << dn->dn_indblkshift : 0;
1830 doi->doi_type = dn->dn_type;
1831 doi->doi_bonus_type = dn->dn_bonustype;
1832 doi->doi_bonus_size = dn->dn_bonuslen;
1833 doi->doi_indirection = dn->dn_nlevels;
1834 doi->doi_checksum = dn->dn_checksum;
1835 doi->doi_compress = dn->dn_compress;
1836 doi->doi_physical_blocks_512 = (DN_USED_BYTES(dnp) + 256) >> 9;
1837 doi->doi_max_offset = (dnp->dn_maxblkid + 1) * dn->dn_datablksz;
1838 doi->doi_fill_count = 0;
1839 for (i = 0; i < dnp->dn_nblkptr; i++)
1840 doi->doi_fill_count += dnp->dn_blkptr[i].blk_fill;
1841
1842 mutex_exit(&dn->dn_mtx);
1843 rw_exit(&dn->dn_struct_rwlock);
1844 }
1845
1846 /*
1847 * Get information on a DMU object.
1848 * If doi is NULL, just indicates whether the object exists.
1849 */
1850 int
1851 dmu_object_info(objset_t *os, uint64_t object, dmu_object_info_t *doi)
1852 {
1853 dnode_t *dn;
1854 int err = dnode_hold(os, object, FTAG, &dn);
1855
1856 if (err)
1857 return (err);
1858
1859 if (doi != NULL)
1860 dmu_object_info_from_dnode(dn, doi);
1861
1862 dnode_rele(dn, FTAG);
1863 return (0);
1864 }
1865
1866 /*
1867 * As above, but faster; can be used when you have a held dbuf in hand.
1868 */
1869 void
1870 dmu_object_info_from_db(dmu_buf_t *db_fake, dmu_object_info_t *doi)
1871 {
1872 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
1873
1874 DB_DNODE_ENTER(db);
1875 dmu_object_info_from_dnode(DB_DNODE(db), doi);
1876 DB_DNODE_EXIT(db);
1877 }
1878
1879 /*
1880 * Faster still when you only care about the size.
1881 * This is specifically optimized for zfs_getattr().
1882 */
1883 void
1884 dmu_object_size_from_db(dmu_buf_t *db_fake, uint32_t *blksize,
1885 u_longlong_t *nblk512)
1886 {
1887 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
1888 dnode_t *dn;
1889
1890 DB_DNODE_ENTER(db);
1891 dn = DB_DNODE(db);
1892
1893 *blksize = dn->dn_datablksz;
1894 /* add 1 for dnode space */
1895 *nblk512 = ((DN_USED_BYTES(dn->dn_phys) + SPA_MINBLOCKSIZE/2) >>
1896 SPA_MINBLOCKSHIFT) + 1;
1897 DB_DNODE_EXIT(db);
1898 }
1899
1900 void
1901 byteswap_uint64_array(void *vbuf, size_t size)
1902 {
1903 uint64_t *buf = vbuf;
1904 size_t count = size >> 3;
1905 int i;
1906
1907 ASSERT((size & 7) == 0);
1908
1909 for (i = 0; i < count; i++)
1910 buf[i] = BSWAP_64(buf[i]);
1911 }
1912
1913 void
1914 byteswap_uint32_array(void *vbuf, size_t size)
1915 {
1916 uint32_t *buf = vbuf;
1917 size_t count = size >> 2;
1918 int i;
1919
1920 ASSERT((size & 3) == 0);
1921
1922 for (i = 0; i < count; i++)
1923 buf[i] = BSWAP_32(buf[i]);
1924 }
1925
1926 void
1927 byteswap_uint16_array(void *vbuf, size_t size)
1928 {
1929 uint16_t *buf = vbuf;
1930 size_t count = size >> 1;
1931 int i;
1932
1933 ASSERT((size & 1) == 0);
1934
1935 for (i = 0; i < count; i++)
1936 buf[i] = BSWAP_16(buf[i]);
1937 }
1938
1939 /* ARGSUSED */
1940 void
1941 byteswap_uint8_array(void *vbuf, size_t size)
1942 {
1943 }
1944
1945 void
1946 dmu_init(void)
1947 {
1948 zfs_dbgmsg_init();
1949 sa_cache_init();
1950 xuio_stat_init();
1951 dmu_objset_init();
1952 dnode_init();
1953 dbuf_init();
1954 zfetch_init();
1955 dmu_tx_init();
1956 l2arc_init();
1957 arc_init();
1958 }
1959
1960 void
1961 dmu_fini(void)
1962 {
1963 arc_fini();
1964 l2arc_fini();
1965 dmu_tx_fini();
1966 zfetch_fini();
1967 dbuf_fini();
1968 dnode_fini();
1969 dmu_objset_fini();
1970 xuio_stat_fini();
1971 sa_cache_fini();
1972 zfs_dbgmsg_fini();
1973 }
1974
1975 #if defined(_KERNEL) && defined(HAVE_SPL)
1976 EXPORT_SYMBOL(dmu_bonus_hold);
1977 EXPORT_SYMBOL(dmu_buf_hold_array_by_bonus);
1978 EXPORT_SYMBOL(dmu_buf_rele_array);
1979 EXPORT_SYMBOL(dmu_free_range);
1980 EXPORT_SYMBOL(dmu_read);
1981 EXPORT_SYMBOL(dmu_write);
1982 EXPORT_SYMBOL(dmu_object_info);
1983 EXPORT_SYMBOL(dmu_object_info_from_dnode);
1984 EXPORT_SYMBOL(dmu_object_info_from_db);
1985 EXPORT_SYMBOL(dmu_object_size_from_db);
1986 EXPORT_SYMBOL(dmu_object_set_blocksize);
1987 EXPORT_SYMBOL(dmu_object_set_checksum);
1988 EXPORT_SYMBOL(dmu_object_set_compress);
1989 EXPORT_SYMBOL(dmu_request_arcbuf);
1990 EXPORT_SYMBOL(dmu_return_arcbuf);
1991 EXPORT_SYMBOL(dmu_assign_arcbuf);
1992 EXPORT_SYMBOL(dmu_buf_hold);
1993 EXPORT_SYMBOL(dmu_ot);
1994
1995 module_param(zfs_mdcomp_disable, int, 0644);
1996 MODULE_PARM_DESC(zfs_mdcomp_disable, "Disable meta data compression");
1997 #endif
ZFS On Linux mirror for PVE