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;
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_SLEEP);
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 bcopy(buf, (char *)db->db_data + bufoff, 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 int
849 dmu_xuio_init(xuio_t *xuio, int nblk)
850 {
851 dmu_xuio_t *priv;
852 uio_t *uio = &xuio->xu_uio;
853
854 uio->uio_iovcnt = nblk;
855 uio->uio_iov = kmem_zalloc(nblk * sizeof (iovec_t), KM_SLEEP);
856
857 priv = kmem_zalloc(sizeof (dmu_xuio_t), KM_SLEEP);
858 priv->cnt = nblk;
859 priv->bufs = kmem_zalloc(nblk * sizeof (arc_buf_t *), KM_SLEEP);
860 priv->iovp = uio->uio_iov;
861 XUIO_XUZC_PRIV(xuio) = priv;
862
863 if (XUIO_XUZC_RW(xuio) == UIO_READ)
864 XUIOSTAT_INCR(xuiostat_onloan_rbuf, nblk);
865 else
866 XUIOSTAT_INCR(xuiostat_onloan_wbuf, nblk);
867
868 return (0);
869 }
870
871 void
872 dmu_xuio_fini(xuio_t *xuio)
873 {
874 dmu_xuio_t *priv = XUIO_XUZC_PRIV(xuio);
875 int nblk = priv->cnt;
876
877 kmem_free(priv->iovp, nblk * sizeof (iovec_t));
878 kmem_free(priv->bufs, nblk * sizeof (arc_buf_t *));
879 kmem_free(priv, sizeof (dmu_xuio_t));
880
881 if (XUIO_XUZC_RW(xuio) == UIO_READ)
882 XUIOSTAT_INCR(xuiostat_onloan_rbuf, -nblk);
883 else
884 XUIOSTAT_INCR(xuiostat_onloan_wbuf, -nblk);
885 }
886
887 /*
888 * Initialize iov[priv->next] and priv->bufs[priv->next] with { off, n, abuf }
889 * and increase priv->next by 1.
890 */
891 int
892 dmu_xuio_add(xuio_t *xuio, arc_buf_t *abuf, offset_t off, size_t n)
893 {
894 struct iovec *iov;
895 uio_t *uio = &xuio->xu_uio;
896 dmu_xuio_t *priv = XUIO_XUZC_PRIV(xuio);
897 int i = priv->next++;
898
899 ASSERT(i < priv->cnt);
900 ASSERT(off + n <= arc_buf_size(abuf));
901 iov = uio->uio_iov + i;
902 iov->iov_base = (char *)abuf->b_data + off;
903 iov->iov_len = n;
904 priv->bufs[i] = abuf;
905 return (0);
906 }
907
908 int
909 dmu_xuio_cnt(xuio_t *xuio)
910 {
911 dmu_xuio_t *priv = XUIO_XUZC_PRIV(xuio);
912 return (priv->cnt);
913 }
914
915 arc_buf_t *
916 dmu_xuio_arcbuf(xuio_t *xuio, int i)
917 {
918 dmu_xuio_t *priv = XUIO_XUZC_PRIV(xuio);
919
920 ASSERT(i < priv->cnt);
921 return (priv->bufs[i]);
922 }
923
924 void
925 dmu_xuio_clear(xuio_t *xuio, int i)
926 {
927 dmu_xuio_t *priv = XUIO_XUZC_PRIV(xuio);
928
929 ASSERT(i < priv->cnt);
930 priv->bufs[i] = NULL;
931 }
932
933 static void
934 xuio_stat_init(void)
935 {
936 xuio_ksp = kstat_create("zfs", 0, "xuio_stats", "misc",
937 KSTAT_TYPE_NAMED, sizeof (xuio_stats) / sizeof (kstat_named_t),
938 KSTAT_FLAG_VIRTUAL);
939 if (xuio_ksp != NULL) {
940 xuio_ksp->ks_data = &xuio_stats;
941 kstat_install(xuio_ksp);
942 }
943 }
944
945 static void
946 xuio_stat_fini(void)
947 {
948 if (xuio_ksp != NULL) {
949 kstat_delete(xuio_ksp);
950 xuio_ksp = NULL;
951 }
952 }
953
954 void
955 xuio_stat_wbuf_copied()
956 {
957 XUIOSTAT_BUMP(xuiostat_wbuf_copied);
958 }
959
960 void
961 xuio_stat_wbuf_nocopy()
962 {
963 XUIOSTAT_BUMP(xuiostat_wbuf_nocopy);
964 }
965
966 #ifdef _KERNEL
967 int
968 dmu_read_uio(objset_t *os, uint64_t object, uio_t *uio, uint64_t size)
969 {
970 dmu_buf_t **dbp;
971 int numbufs, i, err;
972 xuio_t *xuio = NULL;
973
974 /*
975 * NB: we could do this block-at-a-time, but it's nice
976 * to be reading in parallel.
977 */
978 err = dmu_buf_hold_array(os, object, uio->uio_loffset, size, TRUE, FTAG,
979 &numbufs, &dbp);
980 if (err)
981 return (err);
982
983 if (uio->uio_extflg == UIO_XUIO)
984 xuio = (xuio_t *)uio;
985
986 for (i = 0; i < numbufs; i++) {
987 int tocpy;
988 int bufoff;
989 dmu_buf_t *db = dbp[i];
990
991 ASSERT(size > 0);
992
993 bufoff = uio->uio_loffset - db->db_offset;
994 tocpy = (int)MIN(db->db_size - bufoff, size);
995
996 if (xuio) {
997 dmu_buf_impl_t *dbi = (dmu_buf_impl_t *)db;
998 arc_buf_t *dbuf_abuf = dbi->db_buf;
999 arc_buf_t *abuf = dbuf_loan_arcbuf(dbi);
1000 err = dmu_xuio_add(xuio, abuf, bufoff, tocpy);
1001 if (!err) {
1002 uio->uio_resid -= tocpy;
1003 uio->uio_loffset += tocpy;
1004 }
1005
1006 if (abuf == dbuf_abuf)
1007 XUIOSTAT_BUMP(xuiostat_rbuf_nocopy);
1008 else
1009 XUIOSTAT_BUMP(xuiostat_rbuf_copied);
1010 } else {
1011 err = uiomove((char *)db->db_data + bufoff, tocpy,
1012 UIO_READ, uio);
1013 }
1014 if (err)
1015 break;
1016
1017 size -= tocpy;
1018 }
1019 dmu_buf_rele_array(dbp, numbufs, FTAG);
1020
1021 return (err);
1022 }
1023
1024 static int
1025 dmu_write_uio_dnode(dnode_t *dn, uio_t *uio, uint64_t size, dmu_tx_t *tx)
1026 {
1027 dmu_buf_t **dbp;
1028 int numbufs;
1029 int err = 0;
1030 int i;
1031
1032 err = dmu_buf_hold_array_by_dnode(dn, uio->uio_loffset, size,
1033 FALSE, FTAG, &numbufs, &dbp, DMU_READ_PREFETCH);
1034 if (err)
1035 return (err);
1036
1037 for (i = 0; i < numbufs; i++) {
1038 int tocpy;
1039 int bufoff;
1040 dmu_buf_t *db = dbp[i];
1041
1042 ASSERT(size > 0);
1043
1044 bufoff = uio->uio_loffset - db->db_offset;
1045 tocpy = (int)MIN(db->db_size - bufoff, size);
1046
1047 ASSERT(i == 0 || i == numbufs-1 || tocpy == db->db_size);
1048
1049 if (tocpy == db->db_size)
1050 dmu_buf_will_fill(db, tx);
1051 else
1052 dmu_buf_will_dirty(db, tx);
1053
1054 /*
1055 * XXX uiomove could block forever (eg. nfs-backed
1056 * pages). There needs to be a uiolockdown() function
1057 * to lock the pages in memory, so that uiomove won't
1058 * block.
1059 */
1060 err = uiomove((char *)db->db_data + bufoff, tocpy,
1061 UIO_WRITE, uio);
1062
1063 if (tocpy == db->db_size)
1064 dmu_buf_fill_done(db, tx);
1065
1066 if (err)
1067 break;
1068
1069 size -= tocpy;
1070 }
1071
1072 dmu_buf_rele_array(dbp, numbufs, FTAG);
1073 return (err);
1074 }
1075
1076 int
1077 dmu_write_uio_dbuf(dmu_buf_t *zdb, uio_t *uio, uint64_t size,
1078 dmu_tx_t *tx)
1079 {
1080 dmu_buf_impl_t *db = (dmu_buf_impl_t *)zdb;
1081 dnode_t *dn;
1082 int err;
1083
1084 if (size == 0)
1085 return (0);
1086
1087 DB_DNODE_ENTER(db);
1088 dn = DB_DNODE(db);
1089 err = dmu_write_uio_dnode(dn, uio, size, tx);
1090 DB_DNODE_EXIT(db);
1091
1092 return (err);
1093 }
1094
1095 int
1096 dmu_write_uio(objset_t *os, uint64_t object, uio_t *uio, uint64_t size,
1097 dmu_tx_t *tx)
1098 {
1099 dnode_t *dn;
1100 int err;
1101
1102 if (size == 0)
1103 return (0);
1104
1105 err = dnode_hold(os, object, FTAG, &dn);
1106 if (err)
1107 return (err);
1108
1109 err = dmu_write_uio_dnode(dn, uio, size, tx);
1110
1111 dnode_rele(dn, FTAG);
1112
1113 return (err);
1114 }
1115
1116 int
1117 dmu_write_pages(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
1118 page_t *pp, dmu_tx_t *tx)
1119 {
1120 dmu_buf_t **dbp;
1121 int numbufs, i;
1122 int err;
1123
1124 if (size == 0)
1125 return (0);
1126
1127 err = dmu_buf_hold_array(os, object, offset, size,
1128 FALSE, FTAG, &numbufs, &dbp);
1129 if (err)
1130 return (err);
1131
1132 for (i = 0; i < numbufs; i++) {
1133 int tocpy, copied, thiscpy;
1134 int bufoff;
1135 dmu_buf_t *db = dbp[i];
1136 caddr_t va;
1137
1138 ASSERT(size > 0);
1139 ASSERT3U(db->db_size, >=, PAGESIZE);
1140
1141 bufoff = offset - db->db_offset;
1142 tocpy = (int)MIN(db->db_size - bufoff, size);
1143
1144 ASSERT(i == 0 || i == numbufs-1 || tocpy == db->db_size);
1145
1146 if (tocpy == db->db_size)
1147 dmu_buf_will_fill(db, tx);
1148 else
1149 dmu_buf_will_dirty(db, tx);
1150
1151 for (copied = 0; copied < tocpy; copied += PAGESIZE) {
1152 ASSERT3U(pp->p_offset, ==, db->db_offset + bufoff);
1153 thiscpy = MIN(PAGESIZE, tocpy - copied);
1154 va = zfs_map_page(pp, S_READ);
1155 bcopy(va, (char *)db->db_data + bufoff, thiscpy);
1156 zfs_unmap_page(pp, va);
1157 pp = pp->p_next;
1158 bufoff += PAGESIZE;
1159 }
1160
1161 if (tocpy == db->db_size)
1162 dmu_buf_fill_done(db, tx);
1163
1164 offset += tocpy;
1165 size -= tocpy;
1166 }
1167 dmu_buf_rele_array(dbp, numbufs, FTAG);
1168 return (err);
1169 }
1170 #endif
1171
1172 /*
1173 * Allocate a loaned anonymous arc buffer.
1174 */
1175 arc_buf_t *
1176 dmu_request_arcbuf(dmu_buf_t *handle, int size)
1177 {
1178 dmu_buf_impl_t *db = (dmu_buf_impl_t *)handle;
1179 spa_t *spa;
1180
1181 DB_GET_SPA(&spa, db);
1182 return (arc_loan_buf(spa, size));
1183 }
1184
1185 /*
1186 * Free a loaned arc buffer.
1187 */
1188 void
1189 dmu_return_arcbuf(arc_buf_t *buf)
1190 {
1191 arc_return_buf(buf, FTAG);
1192 VERIFY(arc_buf_remove_ref(buf, FTAG) == 1);
1193 }
1194
1195 /*
1196 * When possible directly assign passed loaned arc buffer to a dbuf.
1197 * If this is not possible copy the contents of passed arc buf via
1198 * dmu_write().
1199 */
1200 void
1201 dmu_assign_arcbuf(dmu_buf_t *handle, uint64_t offset, arc_buf_t *buf,
1202 dmu_tx_t *tx)
1203 {
1204 dmu_buf_impl_t *dbuf = (dmu_buf_impl_t *)handle;
1205 dnode_t *dn;
1206 dmu_buf_impl_t *db;
1207 uint32_t blksz = (uint32_t)arc_buf_size(buf);
1208 uint64_t blkid;
1209
1210 DB_DNODE_ENTER(dbuf);
1211 dn = DB_DNODE(dbuf);
1212 rw_enter(&dn->dn_struct_rwlock, RW_READER);
1213 blkid = dbuf_whichblock(dn, offset);
1214 VERIFY((db = dbuf_hold(dn, blkid, FTAG)) != NULL);
1215 rw_exit(&dn->dn_struct_rwlock);
1216 DB_DNODE_EXIT(dbuf);
1217
1218 if (offset == db->db.db_offset && blksz == db->db.db_size) {
1219 dbuf_assign_arcbuf(db, buf, tx);
1220 dbuf_rele(db, FTAG);
1221 } else {
1222 objset_t *os;
1223 uint64_t object;
1224
1225 DB_DNODE_ENTER(dbuf);
1226 dn = DB_DNODE(dbuf);
1227 os = dn->dn_objset;
1228 object = dn->dn_object;
1229 DB_DNODE_EXIT(dbuf);
1230
1231 dbuf_rele(db, FTAG);
1232 dmu_write(os, object, offset, blksz, buf->b_data, tx);
1233 dmu_return_arcbuf(buf);
1234 XUIOSTAT_BUMP(xuiostat_wbuf_copied);
1235 }
1236 }
1237
1238 typedef struct {
1239 dbuf_dirty_record_t *dsa_dr;
1240 dmu_sync_cb_t *dsa_done;
1241 zgd_t *dsa_zgd;
1242 dmu_tx_t *dsa_tx;
1243 } dmu_sync_arg_t;
1244
1245 /* ARGSUSED */
1246 static void
1247 dmu_sync_ready(zio_t *zio, arc_buf_t *buf, void *varg)
1248 {
1249 dmu_sync_arg_t *dsa = varg;
1250 dmu_buf_t *db = dsa->dsa_zgd->zgd_db;
1251 blkptr_t *bp = zio->io_bp;
1252
1253 if (zio->io_error == 0) {
1254 if (BP_IS_HOLE(bp)) {
1255 /*
1256 * A block of zeros may compress to a hole, but the
1257 * block size still needs to be known for replay.
1258 */
1259 BP_SET_LSIZE(bp, db->db_size);
1260 } else {
1261 ASSERT(BP_GET_LEVEL(bp) == 0);
1262 bp->blk_fill = 1;
1263 }
1264 }
1265 }
1266
1267 static void
1268 dmu_sync_late_arrival_ready(zio_t *zio)
1269 {
1270 dmu_sync_ready(zio, NULL, zio->io_private);
1271 }
1272
1273 /* ARGSUSED */
1274 static void
1275 dmu_sync_done(zio_t *zio, arc_buf_t *buf, void *varg)
1276 {
1277 dmu_sync_arg_t *dsa = varg;
1278 dbuf_dirty_record_t *dr = dsa->dsa_dr;
1279 dmu_buf_impl_t *db = dr->dr_dbuf;
1280
1281 mutex_enter(&db->db_mtx);
1282 ASSERT(dr->dt.dl.dr_override_state == DR_IN_DMU_SYNC);
1283 if (zio->io_error == 0) {
1284 dr->dt.dl.dr_overridden_by = *zio->io_bp;
1285 dr->dt.dl.dr_override_state = DR_OVERRIDDEN;
1286 dr->dt.dl.dr_copies = zio->io_prop.zp_copies;
1287 if (BP_IS_HOLE(&dr->dt.dl.dr_overridden_by))
1288 BP_ZERO(&dr->dt.dl.dr_overridden_by);
1289 } else {
1290 dr->dt.dl.dr_override_state = DR_NOT_OVERRIDDEN;
1291 }
1292 cv_broadcast(&db->db_changed);
1293 mutex_exit(&db->db_mtx);
1294
1295 dsa->dsa_done(dsa->dsa_zgd, zio->io_error);
1296
1297 kmem_free(dsa, sizeof (*dsa));
1298 }
1299
1300 static void
1301 dmu_sync_late_arrival_done(zio_t *zio)
1302 {
1303 blkptr_t *bp = zio->io_bp;
1304 dmu_sync_arg_t *dsa = zio->io_private;
1305
1306 if (zio->io_error == 0 && !BP_IS_HOLE(bp)) {
1307 ASSERT(zio->io_bp->blk_birth == zio->io_txg);
1308 ASSERT(zio->io_txg > spa_syncing_txg(zio->io_spa));
1309 zio_free(zio->io_spa, zio->io_txg, zio->io_bp);
1310 }
1311
1312 dmu_tx_commit(dsa->dsa_tx);
1313
1314 dsa->dsa_done(dsa->dsa_zgd, zio->io_error);
1315
1316 kmem_free(dsa, sizeof (*dsa));
1317 }
1318
1319 static int
1320 dmu_sync_late_arrival(zio_t *pio, objset_t *os, dmu_sync_cb_t *done, zgd_t *zgd,
1321 zio_prop_t *zp, zbookmark_t *zb)
1322 {
1323 dmu_sync_arg_t *dsa;
1324 dmu_tx_t *tx;
1325
1326 tx = dmu_tx_create(os);
1327 dmu_tx_hold_space(tx, zgd->zgd_db->db_size);
1328 if (dmu_tx_assign(tx, TXG_WAIT) != 0) {
1329 dmu_tx_abort(tx);
1330 return (EIO); /* Make zl_get_data do txg_waited_synced() */
1331 }
1332
1333 dsa = kmem_alloc(sizeof (dmu_sync_arg_t), KM_SLEEP);
1334 dsa->dsa_dr = NULL;
1335 dsa->dsa_done = done;
1336 dsa->dsa_zgd = zgd;
1337 dsa->dsa_tx = tx;
1338
1339 zio_nowait(zio_write(pio, os->os_spa, dmu_tx_get_txg(tx), zgd->zgd_bp,
1340 zgd->zgd_db->db_data, zgd->zgd_db->db_size, zp,
1341 dmu_sync_late_arrival_ready, dmu_sync_late_arrival_done, dsa,
1342 ZIO_PRIORITY_SYNC_WRITE, ZIO_FLAG_CANFAIL, zb));
1343
1344 return (0);
1345 }
1346
1347 /*
1348 * Intent log support: sync the block associated with db to disk.
1349 * N.B. and XXX: the caller is responsible for making sure that the
1350 * data isn't changing while dmu_sync() is writing it.
1351 *
1352 * Return values:
1353 *
1354 * EEXIST: this txg has already been synced, so there's nothing to to.
1355 * The caller should not log the write.
1356 *
1357 * ENOENT: the block was dbuf_free_range()'d, so there's nothing to do.
1358 * The caller should not log the write.
1359 *
1360 * EALREADY: this block is already in the process of being synced.
1361 * The caller should track its progress (somehow).
1362 *
1363 * EIO: could not do the I/O.
1364 * The caller should do a txg_wait_synced().
1365 *
1366 * 0: the I/O has been initiated.
1367 * The caller should log this blkptr in the done callback.
1368 * It is possible that the I/O will fail, in which case
1369 * the error will be reported to the done callback and
1370 * propagated to pio from zio_done().
1371 */
1372 int
1373 dmu_sync(zio_t *pio, uint64_t txg, dmu_sync_cb_t *done, zgd_t *zgd)
1374 {
1375 blkptr_t *bp = zgd->zgd_bp;
1376 dmu_buf_impl_t *db = (dmu_buf_impl_t *)zgd->zgd_db;
1377 objset_t *os = db->db_objset;
1378 dsl_dataset_t *ds = os->os_dsl_dataset;
1379 dbuf_dirty_record_t *dr;
1380 dmu_sync_arg_t *dsa;
1381 zbookmark_t zb;
1382 zio_prop_t zp;
1383 dnode_t *dn;
1384
1385 ASSERT(pio != NULL);
1386 ASSERT(BP_IS_HOLE(bp));
1387 ASSERT(txg != 0);
1388
1389 SET_BOOKMARK(&zb, ds->ds_object,
1390 db->db.db_object, db->db_level, db->db_blkid);
1391
1392 DB_DNODE_ENTER(db);
1393 dn = DB_DNODE(db);
1394 dmu_write_policy(os, dn, db->db_level, WP_DMU_SYNC, &zp);
1395 DB_DNODE_EXIT(db);
1396
1397 /*
1398 * If we're frozen (running ziltest), we always need to generate a bp.
1399 */
1400 if (txg > spa_freeze_txg(os->os_spa))
1401 return (dmu_sync_late_arrival(pio, os, done, zgd, &zp, &zb));
1402
1403 /*
1404 * Grabbing db_mtx now provides a barrier between dbuf_sync_leaf()
1405 * and us. If we determine that this txg is not yet syncing,
1406 * but it begins to sync a moment later, that's OK because the
1407 * sync thread will block in dbuf_sync_leaf() until we drop db_mtx.
1408 */
1409 mutex_enter(&db->db_mtx);
1410
1411 if (txg <= spa_last_synced_txg(os->os_spa)) {
1412 /*
1413 * This txg has already synced. There's nothing to do.
1414 */
1415 mutex_exit(&db->db_mtx);
1416 return (EEXIST);
1417 }
1418
1419 if (txg <= spa_syncing_txg(os->os_spa)) {
1420 /*
1421 * This txg is currently syncing, so we can't mess with
1422 * the dirty record anymore; just write a new log block.
1423 */
1424 mutex_exit(&db->db_mtx);
1425 return (dmu_sync_late_arrival(pio, os, done, zgd, &zp, &zb));
1426 }
1427
1428 dr = db->db_last_dirty;
1429 while (dr && dr->dr_txg != txg)
1430 dr = dr->dr_next;
1431
1432 if (dr == NULL) {
1433 /*
1434 * There's no dr for this dbuf, so it must have been freed.
1435 * There's no need to log writes to freed blocks, so we're done.
1436 */
1437 mutex_exit(&db->db_mtx);
1438 return (ENOENT);
1439 }
1440
1441 ASSERT(dr->dr_txg == txg);
1442 if (dr->dt.dl.dr_override_state == DR_IN_DMU_SYNC ||
1443 dr->dt.dl.dr_override_state == DR_OVERRIDDEN) {
1444 /*
1445 * We have already issued a sync write for this buffer,
1446 * or this buffer has already been synced. It could not
1447 * have been dirtied since, or we would have cleared the state.
1448 */
1449 mutex_exit(&db->db_mtx);
1450 return (EALREADY);
1451 }
1452
1453 ASSERT(dr->dt.dl.dr_override_state == DR_NOT_OVERRIDDEN);
1454 dr->dt.dl.dr_override_state = DR_IN_DMU_SYNC;
1455 mutex_exit(&db->db_mtx);
1456
1457 dsa = kmem_alloc(sizeof (dmu_sync_arg_t), KM_SLEEP);
1458 dsa->dsa_dr = dr;
1459 dsa->dsa_done = done;
1460 dsa->dsa_zgd = zgd;
1461 dsa->dsa_tx = NULL;
1462
1463 zio_nowait(arc_write(pio, os->os_spa, txg,
1464 bp, dr->dt.dl.dr_data, DBUF_IS_L2CACHEABLE(db), &zp,
1465 dmu_sync_ready, dmu_sync_done, dsa,
1466 ZIO_PRIORITY_SYNC_WRITE, ZIO_FLAG_CANFAIL, &zb));
1467
1468 return (0);
1469 }
1470
1471 int
1472 dmu_object_set_blocksize(objset_t *os, uint64_t object, uint64_t size, int ibs,
1473 dmu_tx_t *tx)
1474 {
1475 dnode_t *dn;
1476 int err;
1477
1478 err = dnode_hold(os, object, FTAG, &dn);
1479 if (err)
1480 return (err);
1481 err = dnode_set_blksz(dn, size, ibs, tx);
1482 dnode_rele(dn, FTAG);
1483 return (err);
1484 }
1485
1486 void
1487 dmu_object_set_checksum(objset_t *os, uint64_t object, uint8_t checksum,
1488 dmu_tx_t *tx)
1489 {
1490 dnode_t *dn;
1491
1492 /* XXX assumes dnode_hold will not get an i/o error */
1493 (void) dnode_hold(os, object, FTAG, &dn);
1494 ASSERT(checksum < ZIO_CHECKSUM_FUNCTIONS);
1495 dn->dn_checksum = checksum;
1496 dnode_setdirty(dn, tx);
1497 dnode_rele(dn, FTAG);
1498 }
1499
1500 void
1501 dmu_object_set_compress(objset_t *os, uint64_t object, uint8_t compress,
1502 dmu_tx_t *tx)
1503 {
1504 dnode_t *dn;
1505
1506 /* XXX assumes dnode_hold will not get an i/o error */
1507 (void) dnode_hold(os, object, FTAG, &dn);
1508 ASSERT(compress < ZIO_COMPRESS_FUNCTIONS);
1509 dn->dn_compress = compress;
1510 dnode_setdirty(dn, tx);
1511 dnode_rele(dn, FTAG);
1512 }
1513
1514 int zfs_mdcomp_disable = 0;
1515
1516 void
1517 dmu_write_policy(objset_t *os, dnode_t *dn, int level, int wp, zio_prop_t *zp)
1518 {
1519 dmu_object_type_t type = dn ? dn->dn_type : DMU_OT_OBJSET;
1520 boolean_t ismd = (level > 0 || DMU_OT_IS_METADATA(type) ||
1521 (wp & WP_SPILL));
1522 enum zio_checksum checksum = os->os_checksum;
1523 enum zio_compress compress = os->os_compress;
1524 enum zio_checksum dedup_checksum = os->os_dedup_checksum;
1525 boolean_t dedup;
1526 boolean_t dedup_verify = os->os_dedup_verify;
1527 int copies = os->os_copies;
1528
1529 /*
1530 * Determine checksum setting.
1531 */
1532 if (ismd) {
1533 /*
1534 * Metadata always gets checksummed. If the data
1535 * checksum is multi-bit correctable, and it's not a
1536 * ZBT-style checksum, then it's suitable for metadata
1537 * as well. Otherwise, the metadata checksum defaults
1538 * to fletcher4.
1539 */
1540 if (zio_checksum_table[checksum].ci_correctable < 1 ||
1541 zio_checksum_table[checksum].ci_eck)
1542 checksum = ZIO_CHECKSUM_FLETCHER_4;
1543 } else {
1544 checksum = zio_checksum_select(dn->dn_checksum, checksum);
1545 }
1546
1547 /*
1548 * Determine compression setting.
1549 */
1550 if (ismd) {
1551 /*
1552 * XXX -- we should design a compression algorithm
1553 * that specializes in arrays of bps.
1554 */
1555 compress = zfs_mdcomp_disable ? ZIO_COMPRESS_EMPTY :
1556 ZIO_COMPRESS_LZJB;
1557 } else {
1558 compress = zio_compress_select(dn->dn_compress, compress);
1559 }
1560
1561 /*
1562 * Determine dedup setting. If we are in dmu_sync(), we won't
1563 * actually dedup now because that's all done in syncing context;
1564 * but we do want to use the dedup checkum. If the checksum is not
1565 * strong enough to ensure unique signatures, force dedup_verify.
1566 */
1567 dedup = (!ismd && dedup_checksum != ZIO_CHECKSUM_OFF);
1568 if (dedup) {
1569 checksum = dedup_checksum;
1570 if (!zio_checksum_table[checksum].ci_dedup)
1571 dedup_verify = 1;
1572 }
1573
1574 if (wp & WP_DMU_SYNC)
1575 dedup = 0;
1576
1577 if (wp & WP_NOFILL) {
1578 ASSERT(!ismd && level == 0);
1579 checksum = ZIO_CHECKSUM_OFF;
1580 compress = ZIO_COMPRESS_OFF;
1581 dedup = B_FALSE;
1582 }
1583
1584 zp->zp_checksum = checksum;
1585 zp->zp_compress = compress;
1586 zp->zp_type = (wp & WP_SPILL) ? dn->dn_bonustype : type;
1587 zp->zp_level = level;
1588 zp->zp_copies = MIN(copies + ismd, spa_max_replication(os->os_spa));
1589 zp->zp_dedup = dedup;
1590 zp->zp_dedup_verify = dedup && dedup_verify;
1591 }
1592
1593 int
1594 dmu_offset_next(objset_t *os, uint64_t object, boolean_t hole, uint64_t *off)
1595 {
1596 dnode_t *dn;
1597 int i, err;
1598
1599 err = dnode_hold(os, object, FTAG, &dn);
1600 if (err)
1601 return (err);
1602 /*
1603 * Sync any current changes before
1604 * we go trundling through the block pointers.
1605 */
1606 for (i = 0; i < TXG_SIZE; i++) {
1607 if (list_link_active(&dn->dn_dirty_link[i]))
1608 break;
1609 }
1610 if (i != TXG_SIZE) {
1611 dnode_rele(dn, FTAG);
1612 txg_wait_synced(dmu_objset_pool(os), 0);
1613 err = dnode_hold(os, object, FTAG, &dn);
1614 if (err)
1615 return (err);
1616 }
1617
1618 err = dnode_next_offset(dn, (hole ? DNODE_FIND_HOLE : 0), off, 1, 1, 0);
1619 dnode_rele(dn, FTAG);
1620
1621 return (err);
1622 }
1623
1624 void
1625 dmu_object_info_from_dnode(dnode_t *dn, dmu_object_info_t *doi)
1626 {
1627 dnode_phys_t *dnp;
1628
1629 rw_enter(&dn->dn_struct_rwlock, RW_READER);
1630 mutex_enter(&dn->dn_mtx);
1631
1632 dnp = dn->dn_phys;
1633
1634 doi->doi_data_block_size = dn->dn_datablksz;
1635 doi->doi_metadata_block_size = dn->dn_indblkshift ?
1636 1ULL << dn->dn_indblkshift : 0;
1637 doi->doi_type = dn->dn_type;
1638 doi->doi_bonus_type = dn->dn_bonustype;
1639 doi->doi_bonus_size = dn->dn_bonuslen;
1640 doi->doi_indirection = dn->dn_nlevels;
1641 doi->doi_checksum = dn->dn_checksum;
1642 doi->doi_compress = dn->dn_compress;
1643 doi->doi_physical_blocks_512 = (DN_USED_BYTES(dnp) + 256) >> 9;
1644 doi->doi_max_offset = (dnp->dn_maxblkid + 1) * dn->dn_datablksz;
1645 doi->doi_fill_count = 0;
1646 for (int i = 0; i < dnp->dn_nblkptr; i++)
1647 doi->doi_fill_count += dnp->dn_blkptr[i].blk_fill;
1648
1649 mutex_exit(&dn->dn_mtx);
1650 rw_exit(&dn->dn_struct_rwlock);
1651 }
1652
1653 /*
1654 * Get information on a DMU object.
1655 * If doi is NULL, just indicates whether the object exists.
1656 */
1657 int
1658 dmu_object_info(objset_t *os, uint64_t object, dmu_object_info_t *doi)
1659 {
1660 dnode_t *dn;
1661 int err = dnode_hold(os, object, FTAG, &dn);
1662
1663 if (err)
1664 return (err);
1665
1666 if (doi != NULL)
1667 dmu_object_info_from_dnode(dn, doi);
1668
1669 dnode_rele(dn, FTAG);
1670 return (0);
1671 }
1672
1673 /*
1674 * As above, but faster; can be used when you have a held dbuf in hand.
1675 */
1676 void
1677 dmu_object_info_from_db(dmu_buf_t *db_fake, dmu_object_info_t *doi)
1678 {
1679 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
1680
1681 DB_DNODE_ENTER(db);
1682 dmu_object_info_from_dnode(DB_DNODE(db), doi);
1683 DB_DNODE_EXIT(db);
1684 }
1685
1686 /*
1687 * Faster still when you only care about the size.
1688 * This is specifically optimized for zfs_getattr().
1689 */
1690 void
1691 dmu_object_size_from_db(dmu_buf_t *db_fake, uint32_t *blksize,
1692 u_longlong_t *nblk512)
1693 {
1694 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
1695 dnode_t *dn;
1696
1697 DB_DNODE_ENTER(db);
1698 dn = DB_DNODE(db);
1699
1700 *blksize = dn->dn_datablksz;
1701 /* add 1 for dnode space */
1702 *nblk512 = ((DN_USED_BYTES(dn->dn_phys) + SPA_MINBLOCKSIZE/2) >>
1703 SPA_MINBLOCKSHIFT) + 1;
1704 DB_DNODE_EXIT(db);
1705 }
1706
1707 void
1708 byteswap_uint64_array(void *vbuf, size_t size)
1709 {
1710 uint64_t *buf = vbuf;
1711 size_t count = size >> 3;
1712 int i;
1713
1714 ASSERT((size & 7) == 0);
1715
1716 for (i = 0; i < count; i++)
1717 buf[i] = BSWAP_64(buf[i]);
1718 }
1719
1720 void
1721 byteswap_uint32_array(void *vbuf, size_t size)
1722 {
1723 uint32_t *buf = vbuf;
1724 size_t count = size >> 2;
1725 int i;
1726
1727 ASSERT((size & 3) == 0);
1728
1729 for (i = 0; i < count; i++)
1730 buf[i] = BSWAP_32(buf[i]);
1731 }
1732
1733 void
1734 byteswap_uint16_array(void *vbuf, size_t size)
1735 {
1736 uint16_t *buf = vbuf;
1737 size_t count = size >> 1;
1738 int i;
1739
1740 ASSERT((size & 1) == 0);
1741
1742 for (i = 0; i < count; i++)
1743 buf[i] = BSWAP_16(buf[i]);
1744 }
1745
1746 /* ARGSUSED */
1747 void
1748 byteswap_uint8_array(void *vbuf, size_t size)
1749 {
1750 }
1751
1752 void
1753 dmu_init(void)
1754 {
1755 zfs_dbgmsg_init();
1756 sa_cache_init();
1757 xuio_stat_init();
1758 dmu_objset_init();
1759 dnode_init();
1760 dbuf_init();
1761 zfetch_init();
1762 arc_init();
1763 l2arc_init();
1764 }
1765
1766 void
1767 dmu_fini(void)
1768 {
1769 l2arc_fini();
1770 arc_fini();
1771 zfetch_fini();
1772 dbuf_fini();
1773 dnode_fini();
1774 dmu_objset_fini();
1775 xuio_stat_fini();
1776 sa_cache_fini();
1777 zfs_dbgmsg_fini();
1778 }