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Linux 4.1 compat: loop device on ZFS
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1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21 /*
22 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
23 * Copyright (c) 2011, 2014 by Delphix. All rights reserved.
24 * Copyright (c) 2013 by Saso Kiselkov. All rights reserved.
25 * Copyright (c) 2014, Nexenta Systems, Inc. All rights reserved.
26 * Copyright (c) 2015 by Chunwei Chen. All rights reserved.
27 */
28
29 #include <sys/dmu.h>
30 #include <sys/dmu_impl.h>
31 #include <sys/dmu_tx.h>
32 #include <sys/dbuf.h>
33 #include <sys/dnode.h>
34 #include <sys/zfs_context.h>
35 #include <sys/dmu_objset.h>
36 #include <sys/dmu_traverse.h>
37 #include <sys/dsl_dataset.h>
38 #include <sys/dsl_dir.h>
39 #include <sys/dsl_pool.h>
40 #include <sys/dsl_synctask.h>
41 #include <sys/dsl_prop.h>
42 #include <sys/dmu_zfetch.h>
43 #include <sys/zfs_ioctl.h>
44 #include <sys/zap.h>
45 #include <sys/zio_checksum.h>
46 #include <sys/zio_compress.h>
47 #include <sys/sa.h>
48 #include <sys/zfeature.h>
49 #ifdef _KERNEL
50 #include <sys/vmsystm.h>
51 #include <sys/zfs_znode.h>
52 #endif
53
54 /*
55 * Enable/disable nopwrite feature.
56 */
57 int zfs_nopwrite_enabled = 1;
58
59 const dmu_object_type_info_t dmu_ot[DMU_OT_NUMTYPES] = {
60 { DMU_BSWAP_UINT8, TRUE, "unallocated" },
61 { DMU_BSWAP_ZAP, TRUE, "object directory" },
62 { DMU_BSWAP_UINT64, TRUE, "object array" },
63 { DMU_BSWAP_UINT8, TRUE, "packed nvlist" },
64 { DMU_BSWAP_UINT64, TRUE, "packed nvlist size" },
65 { DMU_BSWAP_UINT64, TRUE, "bpobj" },
66 { DMU_BSWAP_UINT64, TRUE, "bpobj header" },
67 { DMU_BSWAP_UINT64, TRUE, "SPA space map header" },
68 { DMU_BSWAP_UINT64, TRUE, "SPA space map" },
69 { DMU_BSWAP_UINT64, TRUE, "ZIL intent log" },
70 { DMU_BSWAP_DNODE, TRUE, "DMU dnode" },
71 { DMU_BSWAP_OBJSET, TRUE, "DMU objset" },
72 { DMU_BSWAP_UINT64, TRUE, "DSL directory" },
73 { DMU_BSWAP_ZAP, TRUE, "DSL directory child map"},
74 { DMU_BSWAP_ZAP, TRUE, "DSL dataset snap map" },
75 { DMU_BSWAP_ZAP, TRUE, "DSL props" },
76 { DMU_BSWAP_UINT64, TRUE, "DSL dataset" },
77 { DMU_BSWAP_ZNODE, TRUE, "ZFS znode" },
78 { DMU_BSWAP_OLDACL, TRUE, "ZFS V0 ACL" },
79 { DMU_BSWAP_UINT8, FALSE, "ZFS plain file" },
80 { DMU_BSWAP_ZAP, TRUE, "ZFS directory" },
81 { DMU_BSWAP_ZAP, TRUE, "ZFS master node" },
82 { DMU_BSWAP_ZAP, TRUE, "ZFS delete queue" },
83 { DMU_BSWAP_UINT8, FALSE, "zvol object" },
84 { DMU_BSWAP_ZAP, TRUE, "zvol prop" },
85 { DMU_BSWAP_UINT8, FALSE, "other uint8[]" },
86 { DMU_BSWAP_UINT64, FALSE, "other uint64[]" },
87 { DMU_BSWAP_ZAP, TRUE, "other ZAP" },
88 { DMU_BSWAP_ZAP, TRUE, "persistent error log" },
89 { DMU_BSWAP_UINT8, TRUE, "SPA history" },
90 { DMU_BSWAP_UINT64, TRUE, "SPA history offsets" },
91 { DMU_BSWAP_ZAP, TRUE, "Pool properties" },
92 { DMU_BSWAP_ZAP, TRUE, "DSL permissions" },
93 { DMU_BSWAP_ACL, TRUE, "ZFS ACL" },
94 { DMU_BSWAP_UINT8, TRUE, "ZFS SYSACL" },
95 { DMU_BSWAP_UINT8, TRUE, "FUID table" },
96 { DMU_BSWAP_UINT64, TRUE, "FUID table size" },
97 { DMU_BSWAP_ZAP, TRUE, "DSL dataset next clones"},
98 { DMU_BSWAP_ZAP, TRUE, "scan work queue" },
99 { DMU_BSWAP_ZAP, TRUE, "ZFS user/group used" },
100 { DMU_BSWAP_ZAP, TRUE, "ZFS user/group quota" },
101 { DMU_BSWAP_ZAP, TRUE, "snapshot refcount tags"},
102 { DMU_BSWAP_ZAP, TRUE, "DDT ZAP algorithm" },
103 { DMU_BSWAP_ZAP, TRUE, "DDT statistics" },
104 { DMU_BSWAP_UINT8, TRUE, "System attributes" },
105 { DMU_BSWAP_ZAP, TRUE, "SA master node" },
106 { DMU_BSWAP_ZAP, TRUE, "SA attr registration" },
107 { DMU_BSWAP_ZAP, TRUE, "SA attr layouts" },
108 { DMU_BSWAP_ZAP, TRUE, "scan translations" },
109 { DMU_BSWAP_UINT8, FALSE, "deduplicated block" },
110 { DMU_BSWAP_ZAP, TRUE, "DSL deadlist map" },
111 { DMU_BSWAP_UINT64, TRUE, "DSL deadlist map hdr" },
112 { DMU_BSWAP_ZAP, TRUE, "DSL dir clones" },
113 { DMU_BSWAP_UINT64, TRUE, "bpobj subobj" }
114 };
115
116 const dmu_object_byteswap_info_t dmu_ot_byteswap[DMU_BSWAP_NUMFUNCS] = {
117 { byteswap_uint8_array, "uint8" },
118 { byteswap_uint16_array, "uint16" },
119 { byteswap_uint32_array, "uint32" },
120 { byteswap_uint64_array, "uint64" },
121 { zap_byteswap, "zap" },
122 { dnode_buf_byteswap, "dnode" },
123 { dmu_objset_byteswap, "objset" },
124 { zfs_znode_byteswap, "znode" },
125 { zfs_oldacl_byteswap, "oldacl" },
126 { zfs_acl_byteswap, "acl" }
127 };
128
129 int
130 dmu_buf_hold_noread(objset_t *os, uint64_t object, uint64_t offset,
131 void *tag, dmu_buf_t **dbp)
132 {
133 dnode_t *dn;
134 uint64_t blkid;
135 dmu_buf_impl_t *db;
136 int err;
137
138 err = dnode_hold(os, object, FTAG, &dn);
139 if (err)
140 return (err);
141 blkid = dbuf_whichblock(dn, offset);
142 rw_enter(&dn->dn_struct_rwlock, RW_READER);
143 db = dbuf_hold(dn, blkid, tag);
144 rw_exit(&dn->dn_struct_rwlock);
145 dnode_rele(dn, FTAG);
146
147 if (db == NULL) {
148 *dbp = NULL;
149 return (SET_ERROR(EIO));
150 }
151
152 *dbp = &db->db;
153 return (err);
154 }
155
156 int
157 dmu_buf_hold(objset_t *os, uint64_t object, uint64_t offset,
158 void *tag, dmu_buf_t **dbp, int flags)
159 {
160 int err;
161 int db_flags = DB_RF_CANFAIL;
162
163 if (flags & DMU_READ_NO_PREFETCH)
164 db_flags |= DB_RF_NOPREFETCH;
165
166 err = dmu_buf_hold_noread(os, object, offset, tag, dbp);
167 if (err == 0) {
168 dmu_buf_impl_t *db = (dmu_buf_impl_t *)(*dbp);
169 err = dbuf_read(db, NULL, db_flags);
170 if (err != 0) {
171 dbuf_rele(db, tag);
172 *dbp = NULL;
173 }
174 }
175
176 return (err);
177 }
178
179 int
180 dmu_bonus_max(void)
181 {
182 return (DN_MAX_BONUSLEN);
183 }
184
185 int
186 dmu_set_bonus(dmu_buf_t *db_fake, int newsize, dmu_tx_t *tx)
187 {
188 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
189 dnode_t *dn;
190 int error;
191
192 DB_DNODE_ENTER(db);
193 dn = DB_DNODE(db);
194
195 if (dn->dn_bonus != db) {
196 error = SET_ERROR(EINVAL);
197 } else if (newsize < 0 || newsize > db_fake->db_size) {
198 error = SET_ERROR(EINVAL);
199 } else {
200 dnode_setbonuslen(dn, newsize, tx);
201 error = 0;
202 }
203
204 DB_DNODE_EXIT(db);
205 return (error);
206 }
207
208 int
209 dmu_set_bonustype(dmu_buf_t *db_fake, dmu_object_type_t type, dmu_tx_t *tx)
210 {
211 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
212 dnode_t *dn;
213 int error;
214
215 DB_DNODE_ENTER(db);
216 dn = DB_DNODE(db);
217
218 if (!DMU_OT_IS_VALID(type)) {
219 error = SET_ERROR(EINVAL);
220 } else if (dn->dn_bonus != db) {
221 error = SET_ERROR(EINVAL);
222 } else {
223 dnode_setbonus_type(dn, type, tx);
224 error = 0;
225 }
226
227 DB_DNODE_EXIT(db);
228 return (error);
229 }
230
231 dmu_object_type_t
232 dmu_get_bonustype(dmu_buf_t *db_fake)
233 {
234 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
235 dnode_t *dn;
236 dmu_object_type_t type;
237
238 DB_DNODE_ENTER(db);
239 dn = DB_DNODE(db);
240 type = dn->dn_bonustype;
241 DB_DNODE_EXIT(db);
242
243 return (type);
244 }
245
246 int
247 dmu_rm_spill(objset_t *os, uint64_t object, dmu_tx_t *tx)
248 {
249 dnode_t *dn;
250 int error;
251
252 error = dnode_hold(os, object, FTAG, &dn);
253 dbuf_rm_spill(dn, tx);
254 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
255 dnode_rm_spill(dn, tx);
256 rw_exit(&dn->dn_struct_rwlock);
257 dnode_rele(dn, FTAG);
258 return (error);
259 }
260
261 /*
262 * returns ENOENT, EIO, or 0.
263 */
264 int
265 dmu_bonus_hold(objset_t *os, uint64_t object, void *tag, dmu_buf_t **dbp)
266 {
267 dnode_t *dn;
268 dmu_buf_impl_t *db;
269 int error;
270
271 error = dnode_hold(os, object, FTAG, &dn);
272 if (error)
273 return (error);
274
275 rw_enter(&dn->dn_struct_rwlock, RW_READER);
276 if (dn->dn_bonus == NULL) {
277 rw_exit(&dn->dn_struct_rwlock);
278 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
279 if (dn->dn_bonus == NULL)
280 dbuf_create_bonus(dn);
281 }
282 db = dn->dn_bonus;
283
284 /* as long as the bonus buf is held, the dnode will be held */
285 if (refcount_add(&db->db_holds, tag) == 1) {
286 VERIFY(dnode_add_ref(dn, db));
287 atomic_inc_32(&dn->dn_dbufs_count);
288 }
289
290 /*
291 * Wait to drop dn_struct_rwlock until after adding the bonus dbuf's
292 * hold and incrementing the dbuf count to ensure that dnode_move() sees
293 * a dnode hold for every dbuf.
294 */
295 rw_exit(&dn->dn_struct_rwlock);
296
297 dnode_rele(dn, FTAG);
298
299 VERIFY(0 == dbuf_read(db, NULL, DB_RF_MUST_SUCCEED | DB_RF_NOPREFETCH));
300
301 *dbp = &db->db;
302 return (0);
303 }
304
305 /*
306 * returns ENOENT, EIO, or 0.
307 *
308 * This interface will allocate a blank spill dbuf when a spill blk
309 * doesn't already exist on the dnode.
310 *
311 * if you only want to find an already existing spill db, then
312 * dmu_spill_hold_existing() should be used.
313 */
314 int
315 dmu_spill_hold_by_dnode(dnode_t *dn, uint32_t flags, void *tag, dmu_buf_t **dbp)
316 {
317 dmu_buf_impl_t *db = NULL;
318 int err;
319
320 if ((flags & DB_RF_HAVESTRUCT) == 0)
321 rw_enter(&dn->dn_struct_rwlock, RW_READER);
322
323 db = dbuf_hold(dn, DMU_SPILL_BLKID, tag);
324
325 if ((flags & DB_RF_HAVESTRUCT) == 0)
326 rw_exit(&dn->dn_struct_rwlock);
327
328 ASSERT(db != NULL);
329 err = dbuf_read(db, NULL, flags);
330 if (err == 0)
331 *dbp = &db->db;
332 else
333 dbuf_rele(db, tag);
334 return (err);
335 }
336
337 int
338 dmu_spill_hold_existing(dmu_buf_t *bonus, void *tag, dmu_buf_t **dbp)
339 {
340 dmu_buf_impl_t *db = (dmu_buf_impl_t *)bonus;
341 dnode_t *dn;
342 int err;
343
344 DB_DNODE_ENTER(db);
345 dn = DB_DNODE(db);
346
347 if (spa_version(dn->dn_objset->os_spa) < SPA_VERSION_SA) {
348 err = SET_ERROR(EINVAL);
349 } else {
350 rw_enter(&dn->dn_struct_rwlock, RW_READER);
351
352 if (!dn->dn_have_spill) {
353 err = SET_ERROR(ENOENT);
354 } else {
355 err = dmu_spill_hold_by_dnode(dn,
356 DB_RF_HAVESTRUCT | DB_RF_CANFAIL, tag, dbp);
357 }
358
359 rw_exit(&dn->dn_struct_rwlock);
360 }
361
362 DB_DNODE_EXIT(db);
363 return (err);
364 }
365
366 int
367 dmu_spill_hold_by_bonus(dmu_buf_t *bonus, void *tag, dmu_buf_t **dbp)
368 {
369 dmu_buf_impl_t *db = (dmu_buf_impl_t *)bonus;
370 dnode_t *dn;
371 int err;
372
373 DB_DNODE_ENTER(db);
374 dn = DB_DNODE(db);
375 err = dmu_spill_hold_by_dnode(dn, DB_RF_CANFAIL, tag, dbp);
376 DB_DNODE_EXIT(db);
377
378 return (err);
379 }
380
381 /*
382 * Note: longer-term, we should modify all of the dmu_buf_*() interfaces
383 * to take a held dnode rather than <os, object> -- the lookup is wasteful,
384 * and can induce severe lock contention when writing to several files
385 * whose dnodes are in the same block.
386 */
387 static int
388 dmu_buf_hold_array_by_dnode(dnode_t *dn, uint64_t offset, uint64_t length,
389 int read, void *tag, int *numbufsp, dmu_buf_t ***dbpp, uint32_t flags)
390 {
391 dmu_buf_t **dbp;
392 uint64_t blkid, nblks, i;
393 uint32_t dbuf_flags;
394 int err;
395 zio_t *zio;
396
397 ASSERT(length <= DMU_MAX_ACCESS);
398
399 dbuf_flags = DB_RF_CANFAIL | DB_RF_NEVERWAIT | DB_RF_HAVESTRUCT;
400 if (flags & DMU_READ_NO_PREFETCH || length > zfetch_array_rd_sz)
401 dbuf_flags |= DB_RF_NOPREFETCH;
402
403 rw_enter(&dn->dn_struct_rwlock, RW_READER);
404 if (dn->dn_datablkshift) {
405 int blkshift = dn->dn_datablkshift;
406 nblks = (P2ROUNDUP(offset+length, 1ULL<<blkshift) -
407 P2ALIGN(offset, 1ULL<<blkshift)) >> blkshift;
408 } else {
409 if (offset + length > dn->dn_datablksz) {
410 zfs_panic_recover("zfs: accessing past end of object "
411 "%llx/%llx (size=%u access=%llu+%llu)",
412 (longlong_t)dn->dn_objset->
413 os_dsl_dataset->ds_object,
414 (longlong_t)dn->dn_object, dn->dn_datablksz,
415 (longlong_t)offset, (longlong_t)length);
416 rw_exit(&dn->dn_struct_rwlock);
417 return (SET_ERROR(EIO));
418 }
419 nblks = 1;
420 }
421 dbp = kmem_zalloc(sizeof (dmu_buf_t *) * nblks, KM_SLEEP);
422
423 zio = zio_root(dn->dn_objset->os_spa, NULL, NULL, ZIO_FLAG_CANFAIL);
424 blkid = dbuf_whichblock(dn, offset);
425 for (i = 0; i < nblks; i++) {
426 dmu_buf_impl_t *db = dbuf_hold(dn, blkid+i, tag);
427 if (db == NULL) {
428 rw_exit(&dn->dn_struct_rwlock);
429 dmu_buf_rele_array(dbp, nblks, tag);
430 zio_nowait(zio);
431 return (SET_ERROR(EIO));
432 }
433 /* initiate async i/o */
434 if (read) {
435 (void) dbuf_read(db, zio, dbuf_flags);
436 }
437 dbp[i] = &db->db;
438 }
439 rw_exit(&dn->dn_struct_rwlock);
440
441 /* wait for async i/o */
442 err = zio_wait(zio);
443 if (err) {
444 dmu_buf_rele_array(dbp, nblks, tag);
445 return (err);
446 }
447
448 /* wait for other io to complete */
449 if (read) {
450 for (i = 0; i < nblks; i++) {
451 dmu_buf_impl_t *db = (dmu_buf_impl_t *)dbp[i];
452 mutex_enter(&db->db_mtx);
453 while (db->db_state == DB_READ ||
454 db->db_state == DB_FILL)
455 cv_wait(&db->db_changed, &db->db_mtx);
456 if (db->db_state == DB_UNCACHED)
457 err = SET_ERROR(EIO);
458 mutex_exit(&db->db_mtx);
459 if (err) {
460 dmu_buf_rele_array(dbp, nblks, tag);
461 return (err);
462 }
463 }
464 }
465
466 *numbufsp = nblks;
467 *dbpp = dbp;
468 return (0);
469 }
470
471 static int
472 dmu_buf_hold_array(objset_t *os, uint64_t object, uint64_t offset,
473 uint64_t length, int read, void *tag, int *numbufsp, dmu_buf_t ***dbpp)
474 {
475 dnode_t *dn;
476 int err;
477
478 err = dnode_hold(os, object, FTAG, &dn);
479 if (err)
480 return (err);
481
482 err = dmu_buf_hold_array_by_dnode(dn, offset, length, read, tag,
483 numbufsp, dbpp, DMU_READ_PREFETCH);
484
485 dnode_rele(dn, FTAG);
486
487 return (err);
488 }
489
490 int
491 dmu_buf_hold_array_by_bonus(dmu_buf_t *db_fake, uint64_t offset,
492 uint64_t length, int read, void *tag, int *numbufsp, dmu_buf_t ***dbpp)
493 {
494 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
495 dnode_t *dn;
496 int err;
497
498 DB_DNODE_ENTER(db);
499 dn = DB_DNODE(db);
500 err = dmu_buf_hold_array_by_dnode(dn, offset, length, read, tag,
501 numbufsp, dbpp, DMU_READ_PREFETCH);
502 DB_DNODE_EXIT(db);
503
504 return (err);
505 }
506
507 void
508 dmu_buf_rele_array(dmu_buf_t **dbp_fake, int numbufs, void *tag)
509 {
510 int i;
511 dmu_buf_impl_t **dbp = (dmu_buf_impl_t **)dbp_fake;
512
513 if (numbufs == 0)
514 return;
515
516 for (i = 0; i < numbufs; i++) {
517 if (dbp[i])
518 dbuf_rele(dbp[i], tag);
519 }
520
521 kmem_free(dbp, sizeof (dmu_buf_t *) * numbufs);
522 }
523
524 /*
525 * Issue prefetch i/os for the given blocks.
526 *
527 * Note: The assumption is that we *know* these blocks will be needed
528 * almost immediately. Therefore, the prefetch i/os will be issued at
529 * ZIO_PRIORITY_SYNC_READ
530 *
531 * Note: indirect blocks and other metadata will be read synchronously,
532 * causing this function to block if they are not already cached.
533 */
534 void
535 dmu_prefetch(objset_t *os, uint64_t object, uint64_t offset, uint64_t len)
536 {
537 dnode_t *dn;
538 uint64_t blkid;
539 int nblks, err;
540
541 if (zfs_prefetch_disable)
542 return;
543
544 if (len == 0) { /* they're interested in the bonus buffer */
545 dn = DMU_META_DNODE(os);
546
547 if (object == 0 || object >= DN_MAX_OBJECT)
548 return;
549
550 rw_enter(&dn->dn_struct_rwlock, RW_READER);
551 blkid = dbuf_whichblock(dn, object * sizeof (dnode_phys_t));
552 dbuf_prefetch(dn, blkid, ZIO_PRIORITY_SYNC_READ);
553 rw_exit(&dn->dn_struct_rwlock);
554 return;
555 }
556
557 /*
558 * XXX - Note, if the dnode for the requested object is not
559 * already cached, we will do a *synchronous* read in the
560 * dnode_hold() call. The same is true for any indirects.
561 */
562 err = dnode_hold(os, object, FTAG, &dn);
563 if (err != 0)
564 return;
565
566 rw_enter(&dn->dn_struct_rwlock, RW_READER);
567 if (dn->dn_datablkshift) {
568 int blkshift = dn->dn_datablkshift;
569 nblks = (P2ROUNDUP(offset + len, 1 << blkshift) -
570 P2ALIGN(offset, 1 << blkshift)) >> blkshift;
571 } else {
572 nblks = (offset < dn->dn_datablksz);
573 }
574
575 if (nblks != 0) {
576 int i;
577
578 blkid = dbuf_whichblock(dn, offset);
579 for (i = 0; i < nblks; i++)
580 dbuf_prefetch(dn, blkid + i, ZIO_PRIORITY_SYNC_READ);
581 }
582
583 rw_exit(&dn->dn_struct_rwlock);
584
585 dnode_rele(dn, FTAG);
586 }
587
588 /*
589 * Get the next "chunk" of file data to free. We traverse the file from
590 * the end so that the file gets shorter over time (if we crashes in the
591 * middle, this will leave us in a better state). We find allocated file
592 * data by simply searching the allocated level 1 indirects.
593 *
594 * On input, *start should be the first offset that does not need to be
595 * freed (e.g. "offset + length"). On return, *start will be the first
596 * offset that should be freed.
597 */
598 static int
599 get_next_chunk(dnode_t *dn, uint64_t *start, uint64_t minimum)
600 {
601 uint64_t maxblks = DMU_MAX_ACCESS >> (dn->dn_indblkshift + 1);
602 /* bytes of data covered by a level-1 indirect block */
603 uint64_t iblkrange =
604 dn->dn_datablksz * EPB(dn->dn_indblkshift, SPA_BLKPTRSHIFT);
605 uint64_t blks;
606
607 ASSERT3U(minimum, <=, *start);
608
609 if (*start - minimum <= iblkrange * maxblks) {
610 *start = minimum;
611 return (0);
612 }
613 ASSERT(ISP2(iblkrange));
614
615 for (blks = 0; *start > minimum && blks < maxblks; blks++) {
616 int err;
617
618 /*
619 * dnode_next_offset(BACKWARDS) will find an allocated L1
620 * indirect block at or before the input offset. We must
621 * decrement *start so that it is at the end of the region
622 * to search.
623 */
624 (*start)--;
625 err = dnode_next_offset(dn,
626 DNODE_FIND_BACKWARDS, start, 2, 1, 0);
627
628 /* if there are no indirect blocks before start, we are done */
629 if (err == ESRCH) {
630 *start = minimum;
631 break;
632 } else if (err != 0) {
633 return (err);
634 }
635
636 /* set start to the beginning of this L1 indirect */
637 *start = P2ALIGN(*start, iblkrange);
638 }
639 if (*start < minimum)
640 *start = minimum;
641 return (0);
642 }
643
644 static int
645 dmu_free_long_range_impl(objset_t *os, dnode_t *dn, uint64_t offset,
646 uint64_t length)
647 {
648 uint64_t object_size;
649 int err;
650
651 if (dn == NULL)
652 return (SET_ERROR(EINVAL));
653
654 object_size = (dn->dn_maxblkid + 1) * dn->dn_datablksz;
655 if (offset >= object_size)
656 return (0);
657
658 if (length == DMU_OBJECT_END || offset + length > object_size)
659 length = object_size - offset;
660
661 while (length != 0) {
662 uint64_t chunk_end, chunk_begin;
663 dmu_tx_t *tx;
664
665 chunk_end = chunk_begin = offset + length;
666
667 /* move chunk_begin backwards to the beginning of this chunk */
668 err = get_next_chunk(dn, &chunk_begin, offset);
669 if (err)
670 return (err);
671 ASSERT3U(chunk_begin, >=, offset);
672 ASSERT3U(chunk_begin, <=, chunk_end);
673
674 tx = dmu_tx_create(os);
675 dmu_tx_hold_free(tx, dn->dn_object,
676 chunk_begin, chunk_end - chunk_begin);
677 err = dmu_tx_assign(tx, TXG_WAIT);
678 if (err) {
679 dmu_tx_abort(tx);
680 return (err);
681 }
682 dnode_free_range(dn, chunk_begin, chunk_end - chunk_begin, tx);
683 dmu_tx_commit(tx);
684
685 length -= chunk_end - chunk_begin;
686 }
687 return (0);
688 }
689
690 int
691 dmu_free_long_range(objset_t *os, uint64_t object,
692 uint64_t offset, uint64_t length)
693 {
694 dnode_t *dn;
695 int err;
696
697 err = dnode_hold(os, object, FTAG, &dn);
698 if (err != 0)
699 return (err);
700 err = dmu_free_long_range_impl(os, dn, offset, length);
701
702 /*
703 * It is important to zero out the maxblkid when freeing the entire
704 * file, so that (a) subsequent calls to dmu_free_long_range_impl()
705 * will take the fast path, and (b) dnode_reallocate() can verify
706 * that the entire file has been freed.
707 */
708 if (err == 0 && offset == 0 && length == DMU_OBJECT_END)
709 dn->dn_maxblkid = 0;
710
711 dnode_rele(dn, FTAG);
712 return (err);
713 }
714
715 int
716 dmu_free_long_object(objset_t *os, uint64_t object)
717 {
718 dmu_tx_t *tx;
719 int err;
720
721 err = dmu_free_long_range(os, object, 0, DMU_OBJECT_END);
722 if (err != 0)
723 return (err);
724
725 tx = dmu_tx_create(os);
726 dmu_tx_hold_bonus(tx, object);
727 dmu_tx_hold_free(tx, object, 0, DMU_OBJECT_END);
728 err = dmu_tx_assign(tx, TXG_WAIT);
729 if (err == 0) {
730 err = dmu_object_free(os, object, tx);
731 dmu_tx_commit(tx);
732 } else {
733 dmu_tx_abort(tx);
734 }
735
736 return (err);
737 }
738
739 int
740 dmu_free_range(objset_t *os, uint64_t object, uint64_t offset,
741 uint64_t size, dmu_tx_t *tx)
742 {
743 dnode_t *dn;
744 int err = dnode_hold(os, object, FTAG, &dn);
745 if (err)
746 return (err);
747 ASSERT(offset < UINT64_MAX);
748 ASSERT(size == -1ULL || size <= UINT64_MAX - offset);
749 dnode_free_range(dn, offset, size, tx);
750 dnode_rele(dn, FTAG);
751 return (0);
752 }
753
754 int
755 dmu_read(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
756 void *buf, uint32_t flags)
757 {
758 dnode_t *dn;
759 dmu_buf_t **dbp;
760 int numbufs, err;
761
762 err = dnode_hold(os, object, FTAG, &dn);
763 if (err)
764 return (err);
765
766 /*
767 * Deal with odd block sizes, where there can't be data past the first
768 * block. If we ever do the tail block optimization, we will need to
769 * handle that here as well.
770 */
771 if (dn->dn_maxblkid == 0) {
772 uint64_t newsz = offset > dn->dn_datablksz ? 0 :
773 MIN(size, dn->dn_datablksz - offset);
774 bzero((char *)buf + newsz, size - newsz);
775 size = newsz;
776 }
777
778 while (size > 0) {
779 uint64_t mylen = MIN(size, DMU_MAX_ACCESS / 2);
780 int i;
781
782 /*
783 * NB: we could do this block-at-a-time, but it's nice
784 * to be reading in parallel.
785 */
786 err = dmu_buf_hold_array_by_dnode(dn, offset, mylen,
787 TRUE, FTAG, &numbufs, &dbp, flags);
788 if (err)
789 break;
790
791 for (i = 0; i < numbufs; i++) {
792 uint64_t tocpy;
793 int64_t bufoff;
794 dmu_buf_t *db = dbp[i];
795
796 ASSERT(size > 0);
797
798 bufoff = offset - db->db_offset;
799 tocpy = MIN(db->db_size - bufoff, size);
800
801 (void) memcpy(buf, (char *)db->db_data + bufoff, tocpy);
802
803 offset += tocpy;
804 size -= tocpy;
805 buf = (char *)buf + tocpy;
806 }
807 dmu_buf_rele_array(dbp, numbufs, FTAG);
808 }
809 dnode_rele(dn, FTAG);
810 return (err);
811 }
812
813 void
814 dmu_write(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
815 const void *buf, dmu_tx_t *tx)
816 {
817 dmu_buf_t **dbp;
818 int numbufs, i;
819
820 if (size == 0)
821 return;
822
823 VERIFY0(dmu_buf_hold_array(os, object, offset, size,
824 FALSE, FTAG, &numbufs, &dbp));
825
826 for (i = 0; i < numbufs; i++) {
827 uint64_t tocpy;
828 int64_t bufoff;
829 dmu_buf_t *db = dbp[i];
830
831 ASSERT(size > 0);
832
833 bufoff = offset - db->db_offset;
834 tocpy = MIN(db->db_size - bufoff, size);
835
836 ASSERT(i == 0 || i == numbufs-1 || tocpy == db->db_size);
837
838 if (tocpy == db->db_size)
839 dmu_buf_will_fill(db, tx);
840 else
841 dmu_buf_will_dirty(db, tx);
842
843 (void) memcpy((char *)db->db_data + bufoff, buf, tocpy);
844
845 if (tocpy == db->db_size)
846 dmu_buf_fill_done(db, tx);
847
848 offset += tocpy;
849 size -= tocpy;
850 buf = (char *)buf + tocpy;
851 }
852 dmu_buf_rele_array(dbp, numbufs, FTAG);
853 }
854
855 void
856 dmu_prealloc(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
857 dmu_tx_t *tx)
858 {
859 dmu_buf_t **dbp;
860 int numbufs, i;
861
862 if (size == 0)
863 return;
864
865 VERIFY(0 == dmu_buf_hold_array(os, object, offset, size,
866 FALSE, FTAG, &numbufs, &dbp));
867
868 for (i = 0; i < numbufs; i++) {
869 dmu_buf_t *db = dbp[i];
870
871 dmu_buf_will_not_fill(db, tx);
872 }
873 dmu_buf_rele_array(dbp, numbufs, FTAG);
874 }
875
876 void
877 dmu_write_embedded(objset_t *os, uint64_t object, uint64_t offset,
878 void *data, uint8_t etype, uint8_t comp, int uncompressed_size,
879 int compressed_size, int byteorder, dmu_tx_t *tx)
880 {
881 dmu_buf_t *db;
882
883 ASSERT3U(etype, <, NUM_BP_EMBEDDED_TYPES);
884 ASSERT3U(comp, <, ZIO_COMPRESS_FUNCTIONS);
885 VERIFY0(dmu_buf_hold_noread(os, object, offset,
886 FTAG, &db));
887
888 dmu_buf_write_embedded(db,
889 data, (bp_embedded_type_t)etype, (enum zio_compress)comp,
890 uncompressed_size, compressed_size, byteorder, tx);
891
892 dmu_buf_rele(db, FTAG);
893 }
894
895 /*
896 * DMU support for xuio
897 */
898 kstat_t *xuio_ksp = NULL;
899
900 typedef struct xuio_stats {
901 /* loaned yet not returned arc_buf */
902 kstat_named_t xuiostat_onloan_rbuf;
903 kstat_named_t xuiostat_onloan_wbuf;
904 /* whether a copy is made when loaning out a read buffer */
905 kstat_named_t xuiostat_rbuf_copied;
906 kstat_named_t xuiostat_rbuf_nocopy;
907 /* whether a copy is made when assigning a write buffer */
908 kstat_named_t xuiostat_wbuf_copied;
909 kstat_named_t xuiostat_wbuf_nocopy;
910 } xuio_stats_t;
911
912 static xuio_stats_t xuio_stats = {
913 { "onloan_read_buf", KSTAT_DATA_UINT64 },
914 { "onloan_write_buf", KSTAT_DATA_UINT64 },
915 { "read_buf_copied", KSTAT_DATA_UINT64 },
916 { "read_buf_nocopy", KSTAT_DATA_UINT64 },
917 { "write_buf_copied", KSTAT_DATA_UINT64 },
918 { "write_buf_nocopy", KSTAT_DATA_UINT64 }
919 };
920
921 #define XUIOSTAT_INCR(stat, val) \
922 atomic_add_64(&xuio_stats.stat.value.ui64, (val))
923 #define XUIOSTAT_BUMP(stat) XUIOSTAT_INCR(stat, 1)
924
925 int
926 dmu_xuio_init(xuio_t *xuio, int nblk)
927 {
928 dmu_xuio_t *priv;
929 uio_t *uio = &xuio->xu_uio;
930
931 uio->uio_iovcnt = nblk;
932 uio->uio_iov = kmem_zalloc(nblk * sizeof (iovec_t), KM_SLEEP);
933
934 priv = kmem_zalloc(sizeof (dmu_xuio_t), KM_SLEEP);
935 priv->cnt = nblk;
936 priv->bufs = kmem_zalloc(nblk * sizeof (arc_buf_t *), KM_SLEEP);
937 priv->iovp = (iovec_t *)uio->uio_iov;
938 XUIO_XUZC_PRIV(xuio) = priv;
939
940 if (XUIO_XUZC_RW(xuio) == UIO_READ)
941 XUIOSTAT_INCR(xuiostat_onloan_rbuf, nblk);
942 else
943 XUIOSTAT_INCR(xuiostat_onloan_wbuf, nblk);
944
945 return (0);
946 }
947
948 void
949 dmu_xuio_fini(xuio_t *xuio)
950 {
951 dmu_xuio_t *priv = XUIO_XUZC_PRIV(xuio);
952 int nblk = priv->cnt;
953
954 kmem_free(priv->iovp, nblk * sizeof (iovec_t));
955 kmem_free(priv->bufs, nblk * sizeof (arc_buf_t *));
956 kmem_free(priv, sizeof (dmu_xuio_t));
957
958 if (XUIO_XUZC_RW(xuio) == UIO_READ)
959 XUIOSTAT_INCR(xuiostat_onloan_rbuf, -nblk);
960 else
961 XUIOSTAT_INCR(xuiostat_onloan_wbuf, -nblk);
962 }
963
964 /*
965 * Initialize iov[priv->next] and priv->bufs[priv->next] with { off, n, abuf }
966 * and increase priv->next by 1.
967 */
968 int
969 dmu_xuio_add(xuio_t *xuio, arc_buf_t *abuf, offset_t off, size_t n)
970 {
971 struct iovec *iov;
972 uio_t *uio = &xuio->xu_uio;
973 dmu_xuio_t *priv = XUIO_XUZC_PRIV(xuio);
974 int i = priv->next++;
975
976 ASSERT(i < priv->cnt);
977 ASSERT(off + n <= arc_buf_size(abuf));
978 iov = (iovec_t *)uio->uio_iov + i;
979 iov->iov_base = (char *)abuf->b_data + off;
980 iov->iov_len = n;
981 priv->bufs[i] = abuf;
982 return (0);
983 }
984
985 int
986 dmu_xuio_cnt(xuio_t *xuio)
987 {
988 dmu_xuio_t *priv = XUIO_XUZC_PRIV(xuio);
989 return (priv->cnt);
990 }
991
992 arc_buf_t *
993 dmu_xuio_arcbuf(xuio_t *xuio, int i)
994 {
995 dmu_xuio_t *priv = XUIO_XUZC_PRIV(xuio);
996
997 ASSERT(i < priv->cnt);
998 return (priv->bufs[i]);
999 }
1000
1001 void
1002 dmu_xuio_clear(xuio_t *xuio, int i)
1003 {
1004 dmu_xuio_t *priv = XUIO_XUZC_PRIV(xuio);
1005
1006 ASSERT(i < priv->cnt);
1007 priv->bufs[i] = NULL;
1008 }
1009
1010 static void
1011 xuio_stat_init(void)
1012 {
1013 xuio_ksp = kstat_create("zfs", 0, "xuio_stats", "misc",
1014 KSTAT_TYPE_NAMED, sizeof (xuio_stats) / sizeof (kstat_named_t),
1015 KSTAT_FLAG_VIRTUAL);
1016 if (xuio_ksp != NULL) {
1017 xuio_ksp->ks_data = &xuio_stats;
1018 kstat_install(xuio_ksp);
1019 }
1020 }
1021
1022 static void
1023 xuio_stat_fini(void)
1024 {
1025 if (xuio_ksp != NULL) {
1026 kstat_delete(xuio_ksp);
1027 xuio_ksp = NULL;
1028 }
1029 }
1030
1031 void
1032 xuio_stat_wbuf_copied()
1033 {
1034 XUIOSTAT_BUMP(xuiostat_wbuf_copied);
1035 }
1036
1037 void
1038 xuio_stat_wbuf_nocopy()
1039 {
1040 XUIOSTAT_BUMP(xuiostat_wbuf_nocopy);
1041 }
1042
1043 #ifdef _KERNEL
1044
1045 /*
1046 * Copy up to size bytes between arg_buf and req based on the data direction
1047 * described by the req. If an entire req's data cannot be transfered in one
1048 * pass, you should pass in @req_offset to indicate where to continue. The
1049 * return value is the number of bytes successfully copied to arg_buf.
1050 */
1051 static int
1052 dmu_req_copy(void *arg_buf, int size, struct request *req, size_t req_offset)
1053 {
1054 struct bio_vec bv, *bvp;
1055 struct req_iterator iter;
1056 char *bv_buf;
1057 int tocpy, bv_len, bv_offset;
1058 int offset = 0;
1059
1060 rq_for_each_segment4(bv, bvp, req, iter) {
1061 /*
1062 * Fully consumed the passed arg_buf. We use goto here because
1063 * rq_for_each_segment is a double loop
1064 */
1065 ASSERT3S(offset, <=, size);
1066 if (size == offset)
1067 goto out;
1068
1069 /* Skip already copied bv */
1070 if (req_offset >= bv.bv_len) {
1071 req_offset -= bv.bv_len;
1072 continue;
1073 }
1074
1075 bv_len = bv.bv_len - req_offset;
1076 bv_offset = bv.bv_offset + req_offset;
1077 req_offset = 0;
1078
1079 tocpy = MIN(bv_len, size - offset);
1080 ASSERT3S(tocpy, >=, 0);
1081
1082 bv_buf = page_address(bv.bv_page) + bv_offset;
1083 ASSERT3P(bv_buf, !=, NULL);
1084
1085 if (rq_data_dir(req) == WRITE)
1086 memcpy(arg_buf + offset, bv_buf, tocpy);
1087 else
1088 memcpy(bv_buf, arg_buf + offset, tocpy);
1089
1090 offset += tocpy;
1091 }
1092 out:
1093 return (offset);
1094 }
1095
1096 int
1097 dmu_read_req(objset_t *os, uint64_t object, struct request *req)
1098 {
1099 uint64_t size = blk_rq_bytes(req);
1100 uint64_t offset = blk_rq_pos(req) << 9;
1101 dmu_buf_t **dbp;
1102 int numbufs, i, err;
1103 size_t req_offset;
1104
1105 /*
1106 * NB: we could do this block-at-a-time, but it's nice
1107 * to be reading in parallel.
1108 */
1109 err = dmu_buf_hold_array(os, object, offset, size, TRUE, FTAG,
1110 &numbufs, &dbp);
1111 if (err)
1112 return (err);
1113
1114 req_offset = 0;
1115 for (i = 0; i < numbufs; i++) {
1116 uint64_t tocpy;
1117 int64_t bufoff;
1118 int didcpy;
1119 dmu_buf_t *db = dbp[i];
1120
1121 bufoff = offset - db->db_offset;
1122 ASSERT3S(bufoff, >=, 0);
1123
1124 tocpy = MIN(db->db_size - bufoff, size);
1125 if (tocpy == 0)
1126 break;
1127
1128 didcpy = dmu_req_copy(db->db_data + bufoff, tocpy, req,
1129 req_offset);
1130
1131 if (didcpy < tocpy)
1132 err = EIO;
1133
1134 if (err)
1135 break;
1136
1137 size -= tocpy;
1138 offset += didcpy;
1139 req_offset += didcpy;
1140 err = 0;
1141 }
1142 dmu_buf_rele_array(dbp, numbufs, FTAG);
1143
1144 return (err);
1145 }
1146
1147 int
1148 dmu_write_req(objset_t *os, uint64_t object, struct request *req, dmu_tx_t *tx)
1149 {
1150 uint64_t size = blk_rq_bytes(req);
1151 uint64_t offset = blk_rq_pos(req) << 9;
1152 dmu_buf_t **dbp;
1153 int numbufs, i, err;
1154 size_t req_offset;
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 req_offset = 0;
1165 for (i = 0; i < numbufs; i++) {
1166 uint64_t tocpy;
1167 int64_t bufoff;
1168 int didcpy;
1169 dmu_buf_t *db = dbp[i];
1170
1171 bufoff = offset - db->db_offset;
1172 ASSERT3S(bufoff, >=, 0);
1173
1174 tocpy = MIN(db->db_size - bufoff, size);
1175 if (tocpy == 0)
1176 break;
1177
1178 ASSERT(i == 0 || i == numbufs-1 || tocpy == db->db_size);
1179
1180 if (tocpy == db->db_size)
1181 dmu_buf_will_fill(db, tx);
1182 else
1183 dmu_buf_will_dirty(db, tx);
1184
1185 didcpy = dmu_req_copy(db->db_data + bufoff, tocpy, req,
1186 req_offset);
1187
1188 if (tocpy == db->db_size)
1189 dmu_buf_fill_done(db, tx);
1190
1191 if (didcpy < tocpy)
1192 err = EIO;
1193
1194 if (err)
1195 break;
1196
1197 size -= tocpy;
1198 offset += didcpy;
1199 req_offset += didcpy;
1200 err = 0;
1201 }
1202
1203 dmu_buf_rele_array(dbp, numbufs, FTAG);
1204 return (err);
1205 }
1206
1207 static int
1208 dmu_read_uio_dnode(dnode_t *dn, uio_t *uio, uint64_t size)
1209 {
1210 dmu_buf_t **dbp;
1211 int numbufs, i, err;
1212 xuio_t *xuio = NULL;
1213
1214 /*
1215 * NB: we could do this block-at-a-time, but it's nice
1216 * to be reading in parallel.
1217 */
1218 err = dmu_buf_hold_array_by_dnode(dn, uio->uio_loffset, size,
1219 TRUE, FTAG, &numbufs, &dbp, 0);
1220 if (err)
1221 return (err);
1222
1223 for (i = 0; i < numbufs; i++) {
1224 uint64_t tocpy;
1225 int64_t bufoff;
1226 dmu_buf_t *db = dbp[i];
1227
1228 ASSERT(size > 0);
1229
1230 bufoff = uio->uio_loffset - db->db_offset;
1231 tocpy = MIN(db->db_size - bufoff, size);
1232
1233 if (xuio) {
1234 dmu_buf_impl_t *dbi = (dmu_buf_impl_t *)db;
1235 arc_buf_t *dbuf_abuf = dbi->db_buf;
1236 arc_buf_t *abuf = dbuf_loan_arcbuf(dbi);
1237 err = dmu_xuio_add(xuio, abuf, bufoff, tocpy);
1238 if (!err) {
1239 uio->uio_resid -= tocpy;
1240 uio->uio_loffset += tocpy;
1241 }
1242
1243 if (abuf == dbuf_abuf)
1244 XUIOSTAT_BUMP(xuiostat_rbuf_nocopy);
1245 else
1246 XUIOSTAT_BUMP(xuiostat_rbuf_copied);
1247 } else {
1248 err = uiomove((char *)db->db_data + bufoff, tocpy,
1249 UIO_READ, uio);
1250 }
1251 if (err)
1252 break;
1253
1254 size -= tocpy;
1255 }
1256 dmu_buf_rele_array(dbp, numbufs, FTAG);
1257
1258 return (err);
1259 }
1260
1261 /*
1262 * Read 'size' bytes into the uio buffer.
1263 * From object zdb->db_object.
1264 * Starting at offset uio->uio_loffset.
1265 *
1266 * If the caller already has a dbuf in the target object
1267 * (e.g. its bonus buffer), this routine is faster than dmu_read_uio(),
1268 * because we don't have to find the dnode_t for the object.
1269 */
1270 int
1271 dmu_read_uio_dbuf(dmu_buf_t *zdb, uio_t *uio, uint64_t size)
1272 {
1273 dmu_buf_impl_t *db = (dmu_buf_impl_t *)zdb;
1274 dnode_t *dn;
1275 int err;
1276
1277 if (size == 0)
1278 return (0);
1279
1280 DB_DNODE_ENTER(db);
1281 dn = DB_DNODE(db);
1282 err = dmu_read_uio_dnode(dn, uio, size);
1283 DB_DNODE_EXIT(db);
1284
1285 return (err);
1286 }
1287
1288 /*
1289 * Read 'size' bytes into the uio buffer.
1290 * From the specified object
1291 * Starting at offset uio->uio_loffset.
1292 */
1293 int
1294 dmu_read_uio(objset_t *os, uint64_t object, uio_t *uio, uint64_t size)
1295 {
1296 dnode_t *dn;
1297 int err;
1298
1299 if (size == 0)
1300 return (0);
1301
1302 err = dnode_hold(os, object, FTAG, &dn);
1303 if (err)
1304 return (err);
1305
1306 err = dmu_read_uio_dnode(dn, uio, size);
1307
1308 dnode_rele(dn, FTAG);
1309
1310 return (err);
1311 }
1312
1313 static int
1314 dmu_write_uio_dnode(dnode_t *dn, uio_t *uio, uint64_t size, dmu_tx_t *tx)
1315 {
1316 dmu_buf_t **dbp;
1317 int numbufs;
1318 int err = 0;
1319 int i;
1320
1321 err = dmu_buf_hold_array_by_dnode(dn, uio->uio_loffset, size,
1322 FALSE, FTAG, &numbufs, &dbp, DMU_READ_PREFETCH);
1323 if (err)
1324 return (err);
1325
1326 for (i = 0; i < numbufs; i++) {
1327 uint64_t tocpy;
1328 int64_t bufoff;
1329 dmu_buf_t *db = dbp[i];
1330
1331 ASSERT(size > 0);
1332
1333 bufoff = uio->uio_loffset - db->db_offset;
1334 tocpy = MIN(db->db_size - bufoff, size);
1335
1336 ASSERT(i == 0 || i == numbufs-1 || tocpy == db->db_size);
1337
1338 if (tocpy == db->db_size)
1339 dmu_buf_will_fill(db, tx);
1340 else
1341 dmu_buf_will_dirty(db, tx);
1342
1343 /*
1344 * XXX uiomove could block forever (eg.nfs-backed
1345 * pages). There needs to be a uiolockdown() function
1346 * to lock the pages in memory, so that uiomove won't
1347 * block.
1348 */
1349 err = uiomove((char *)db->db_data + bufoff, tocpy,
1350 UIO_WRITE, uio);
1351
1352 if (tocpy == db->db_size)
1353 dmu_buf_fill_done(db, tx);
1354
1355 if (err)
1356 break;
1357
1358 size -= tocpy;
1359 }
1360
1361 dmu_buf_rele_array(dbp, numbufs, FTAG);
1362 return (err);
1363 }
1364
1365 /*
1366 * Write 'size' bytes from the uio buffer.
1367 * To object zdb->db_object.
1368 * Starting at offset uio->uio_loffset.
1369 *
1370 * If the caller already has a dbuf in the target object
1371 * (e.g. its bonus buffer), this routine is faster than dmu_write_uio(),
1372 * because we don't have to find the dnode_t for the object.
1373 */
1374 int
1375 dmu_write_uio_dbuf(dmu_buf_t *zdb, uio_t *uio, uint64_t size,
1376 dmu_tx_t *tx)
1377 {
1378 dmu_buf_impl_t *db = (dmu_buf_impl_t *)zdb;
1379 dnode_t *dn;
1380 int err;
1381
1382 if (size == 0)
1383 return (0);
1384
1385 DB_DNODE_ENTER(db);
1386 dn = DB_DNODE(db);
1387 err = dmu_write_uio_dnode(dn, uio, size, tx);
1388 DB_DNODE_EXIT(db);
1389
1390 return (err);
1391 }
1392
1393 /*
1394 * Write 'size' bytes from the uio buffer.
1395 * To the specified object.
1396 * Starting at offset uio->uio_loffset.
1397 */
1398 int
1399 dmu_write_uio(objset_t *os, uint64_t object, uio_t *uio, uint64_t size,
1400 dmu_tx_t *tx)
1401 {
1402 dnode_t *dn;
1403 int err;
1404
1405 if (size == 0)
1406 return (0);
1407
1408 err = dnode_hold(os, object, FTAG, &dn);
1409 if (err)
1410 return (err);
1411
1412 err = dmu_write_uio_dnode(dn, uio, size, tx);
1413
1414 dnode_rele(dn, FTAG);
1415
1416 return (err);
1417 }
1418 #endif /* _KERNEL */
1419
1420 /*
1421 * Allocate a loaned anonymous arc buffer.
1422 */
1423 arc_buf_t *
1424 dmu_request_arcbuf(dmu_buf_t *handle, int size)
1425 {
1426 dmu_buf_impl_t *db = (dmu_buf_impl_t *)handle;
1427
1428 return (arc_loan_buf(db->db_objset->os_spa, size));
1429 }
1430
1431 /*
1432 * Free a loaned arc buffer.
1433 */
1434 void
1435 dmu_return_arcbuf(arc_buf_t *buf)
1436 {
1437 arc_return_buf(buf, FTAG);
1438 VERIFY(arc_buf_remove_ref(buf, FTAG));
1439 }
1440
1441 /*
1442 * When possible directly assign passed loaned arc buffer to a dbuf.
1443 * If this is not possible copy the contents of passed arc buf via
1444 * dmu_write().
1445 */
1446 void
1447 dmu_assign_arcbuf(dmu_buf_t *handle, uint64_t offset, arc_buf_t *buf,
1448 dmu_tx_t *tx)
1449 {
1450 dmu_buf_impl_t *dbuf = (dmu_buf_impl_t *)handle;
1451 dnode_t *dn;
1452 dmu_buf_impl_t *db;
1453 uint32_t blksz = (uint32_t)arc_buf_size(buf);
1454 uint64_t blkid;
1455
1456 DB_DNODE_ENTER(dbuf);
1457 dn = DB_DNODE(dbuf);
1458 rw_enter(&dn->dn_struct_rwlock, RW_READER);
1459 blkid = dbuf_whichblock(dn, offset);
1460 VERIFY((db = dbuf_hold(dn, blkid, FTAG)) != NULL);
1461 rw_exit(&dn->dn_struct_rwlock);
1462 DB_DNODE_EXIT(dbuf);
1463
1464 /*
1465 * We can only assign if the offset is aligned, the arc buf is the
1466 * same size as the dbuf, and the dbuf is not metadata. It
1467 * can't be metadata because the loaned arc buf comes from the
1468 * user-data kmem area.
1469 */
1470 if (offset == db->db.db_offset && blksz == db->db.db_size &&
1471 DBUF_GET_BUFC_TYPE(db) == ARC_BUFC_DATA) {
1472 dbuf_assign_arcbuf(db, buf, tx);
1473 dbuf_rele(db, FTAG);
1474 } else {
1475 objset_t *os;
1476 uint64_t object;
1477
1478 DB_DNODE_ENTER(dbuf);
1479 dn = DB_DNODE(dbuf);
1480 os = dn->dn_objset;
1481 object = dn->dn_object;
1482 DB_DNODE_EXIT(dbuf);
1483
1484 dbuf_rele(db, FTAG);
1485 dmu_write(os, object, offset, blksz, buf->b_data, tx);
1486 dmu_return_arcbuf(buf);
1487 XUIOSTAT_BUMP(xuiostat_wbuf_copied);
1488 }
1489 }
1490
1491 typedef struct {
1492 dbuf_dirty_record_t *dsa_dr;
1493 dmu_sync_cb_t *dsa_done;
1494 zgd_t *dsa_zgd;
1495 dmu_tx_t *dsa_tx;
1496 } dmu_sync_arg_t;
1497
1498 /* ARGSUSED */
1499 static void
1500 dmu_sync_ready(zio_t *zio, arc_buf_t *buf, void *varg)
1501 {
1502 dmu_sync_arg_t *dsa = varg;
1503 dmu_buf_t *db = dsa->dsa_zgd->zgd_db;
1504 blkptr_t *bp = zio->io_bp;
1505
1506 if (zio->io_error == 0) {
1507 if (BP_IS_HOLE(bp)) {
1508 /*
1509 * A block of zeros may compress to a hole, but the
1510 * block size still needs to be known for replay.
1511 */
1512 BP_SET_LSIZE(bp, db->db_size);
1513 } else if (!BP_IS_EMBEDDED(bp)) {
1514 ASSERT(BP_GET_LEVEL(bp) == 0);
1515 bp->blk_fill = 1;
1516 }
1517 }
1518 }
1519
1520 static void
1521 dmu_sync_late_arrival_ready(zio_t *zio)
1522 {
1523 dmu_sync_ready(zio, NULL, zio->io_private);
1524 }
1525
1526 /* ARGSUSED */
1527 static void
1528 dmu_sync_done(zio_t *zio, arc_buf_t *buf, void *varg)
1529 {
1530 dmu_sync_arg_t *dsa = varg;
1531 dbuf_dirty_record_t *dr = dsa->dsa_dr;
1532 dmu_buf_impl_t *db = dr->dr_dbuf;
1533
1534 mutex_enter(&db->db_mtx);
1535 ASSERT(dr->dt.dl.dr_override_state == DR_IN_DMU_SYNC);
1536 if (zio->io_error == 0) {
1537 dr->dt.dl.dr_nopwrite = !!(zio->io_flags & ZIO_FLAG_NOPWRITE);
1538 if (dr->dt.dl.dr_nopwrite) {
1539 ASSERTV(blkptr_t *bp = zio->io_bp);
1540 ASSERTV(blkptr_t *bp_orig = &zio->io_bp_orig);
1541 ASSERTV(uint8_t chksum = BP_GET_CHECKSUM(bp_orig));
1542
1543 ASSERT(BP_EQUAL(bp, bp_orig));
1544 ASSERT(zio->io_prop.zp_compress != ZIO_COMPRESS_OFF);
1545 ASSERT(zio_checksum_table[chksum].ci_dedup);
1546 }
1547 dr->dt.dl.dr_overridden_by = *zio->io_bp;
1548 dr->dt.dl.dr_override_state = DR_OVERRIDDEN;
1549 dr->dt.dl.dr_copies = zio->io_prop.zp_copies;
1550
1551 /*
1552 * Old style holes are filled with all zeros, whereas
1553 * new-style holes maintain their lsize, type, level,
1554 * and birth time (see zio_write_compress). While we
1555 * need to reset the BP_SET_LSIZE() call that happened
1556 * in dmu_sync_ready for old style holes, we do *not*
1557 * want to wipe out the information contained in new
1558 * style holes. Thus, only zero out the block pointer if
1559 * it's an old style hole.
1560 */
1561 if (BP_IS_HOLE(&dr->dt.dl.dr_overridden_by) &&
1562 dr->dt.dl.dr_overridden_by.blk_birth == 0)
1563 BP_ZERO(&dr->dt.dl.dr_overridden_by);
1564 } else {
1565 dr->dt.dl.dr_override_state = DR_NOT_OVERRIDDEN;
1566 }
1567 cv_broadcast(&db->db_changed);
1568 mutex_exit(&db->db_mtx);
1569
1570 dsa->dsa_done(dsa->dsa_zgd, zio->io_error);
1571
1572 kmem_free(dsa, sizeof (*dsa));
1573 }
1574
1575 static void
1576 dmu_sync_late_arrival_done(zio_t *zio)
1577 {
1578 blkptr_t *bp = zio->io_bp;
1579 dmu_sync_arg_t *dsa = zio->io_private;
1580 ASSERTV(blkptr_t *bp_orig = &zio->io_bp_orig);
1581
1582 if (zio->io_error == 0 && !BP_IS_HOLE(bp)) {
1583 /*
1584 * If we didn't allocate a new block (i.e. ZIO_FLAG_NOPWRITE)
1585 * then there is nothing to do here. Otherwise, free the
1586 * newly allocated block in this txg.
1587 */
1588 if (zio->io_flags & ZIO_FLAG_NOPWRITE) {
1589 ASSERT(BP_EQUAL(bp, bp_orig));
1590 } else {
1591 ASSERT(BP_IS_HOLE(bp_orig) || !BP_EQUAL(bp, bp_orig));
1592 ASSERT(zio->io_bp->blk_birth == zio->io_txg);
1593 ASSERT(zio->io_txg > spa_syncing_txg(zio->io_spa));
1594 zio_free(zio->io_spa, zio->io_txg, zio->io_bp);
1595 }
1596 }
1597
1598 dmu_tx_commit(dsa->dsa_tx);
1599
1600 dsa->dsa_done(dsa->dsa_zgd, zio->io_error);
1601
1602 kmem_free(dsa, sizeof (*dsa));
1603 }
1604
1605 static int
1606 dmu_sync_late_arrival(zio_t *pio, objset_t *os, dmu_sync_cb_t *done, zgd_t *zgd,
1607 zio_prop_t *zp, zbookmark_phys_t *zb)
1608 {
1609 dmu_sync_arg_t *dsa;
1610 dmu_tx_t *tx;
1611
1612 tx = dmu_tx_create(os);
1613 dmu_tx_hold_space(tx, zgd->zgd_db->db_size);
1614 if (dmu_tx_assign(tx, TXG_WAIT) != 0) {
1615 dmu_tx_abort(tx);
1616 /* Make zl_get_data do txg_waited_synced() */
1617 return (SET_ERROR(EIO));
1618 }
1619
1620 dsa = kmem_alloc(sizeof (dmu_sync_arg_t), KM_SLEEP);
1621 dsa->dsa_dr = NULL;
1622 dsa->dsa_done = done;
1623 dsa->dsa_zgd = zgd;
1624 dsa->dsa_tx = tx;
1625
1626 zio_nowait(zio_write(pio, os->os_spa, dmu_tx_get_txg(tx), zgd->zgd_bp,
1627 zgd->zgd_db->db_data, zgd->zgd_db->db_size, zp,
1628 dmu_sync_late_arrival_ready, NULL, dmu_sync_late_arrival_done, dsa,
1629 ZIO_PRIORITY_SYNC_WRITE, ZIO_FLAG_CANFAIL|ZIO_FLAG_FASTWRITE, zb));
1630
1631 return (0);
1632 }
1633
1634 /*
1635 * Intent log support: sync the block associated with db to disk.
1636 * N.B. and XXX: the caller is responsible for making sure that the
1637 * data isn't changing while dmu_sync() is writing it.
1638 *
1639 * Return values:
1640 *
1641 * EEXIST: this txg has already been synced, so there's nothing to do.
1642 * The caller should not log the write.
1643 *
1644 * ENOENT: the block was dbuf_free_range()'d, so there's nothing to do.
1645 * The caller should not log the write.
1646 *
1647 * EALREADY: this block is already in the process of being synced.
1648 * The caller should track its progress (somehow).
1649 *
1650 * EIO: could not do the I/O.
1651 * The caller should do a txg_wait_synced().
1652 *
1653 * 0: the I/O has been initiated.
1654 * The caller should log this blkptr in the done callback.
1655 * It is possible that the I/O will fail, in which case
1656 * the error will be reported to the done callback and
1657 * propagated to pio from zio_done().
1658 */
1659 int
1660 dmu_sync(zio_t *pio, uint64_t txg, dmu_sync_cb_t *done, zgd_t *zgd)
1661 {
1662 blkptr_t *bp = zgd->zgd_bp;
1663 dmu_buf_impl_t *db = (dmu_buf_impl_t *)zgd->zgd_db;
1664 objset_t *os = db->db_objset;
1665 dsl_dataset_t *ds = os->os_dsl_dataset;
1666 dbuf_dirty_record_t *dr;
1667 dmu_sync_arg_t *dsa;
1668 zbookmark_phys_t zb;
1669 zio_prop_t zp;
1670 dnode_t *dn;
1671
1672 ASSERT(pio != NULL);
1673 ASSERT(txg != 0);
1674
1675 SET_BOOKMARK(&zb, ds->ds_object,
1676 db->db.db_object, db->db_level, db->db_blkid);
1677
1678 DB_DNODE_ENTER(db);
1679 dn = DB_DNODE(db);
1680 dmu_write_policy(os, dn, db->db_level, WP_DMU_SYNC, &zp);
1681 DB_DNODE_EXIT(db);
1682
1683 /*
1684 * If we're frozen (running ziltest), we always need to generate a bp.
1685 */
1686 if (txg > spa_freeze_txg(os->os_spa))
1687 return (dmu_sync_late_arrival(pio, os, done, zgd, &zp, &zb));
1688
1689 /*
1690 * Grabbing db_mtx now provides a barrier between dbuf_sync_leaf()
1691 * and us. If we determine that this txg is not yet syncing,
1692 * but it begins to sync a moment later, that's OK because the
1693 * sync thread will block in dbuf_sync_leaf() until we drop db_mtx.
1694 */
1695 mutex_enter(&db->db_mtx);
1696
1697 if (txg <= spa_last_synced_txg(os->os_spa)) {
1698 /*
1699 * This txg has already synced. There's nothing to do.
1700 */
1701 mutex_exit(&db->db_mtx);
1702 return (SET_ERROR(EEXIST));
1703 }
1704
1705 if (txg <= spa_syncing_txg(os->os_spa)) {
1706 /*
1707 * This txg is currently syncing, so we can't mess with
1708 * the dirty record anymore; just write a new log block.
1709 */
1710 mutex_exit(&db->db_mtx);
1711 return (dmu_sync_late_arrival(pio, os, done, zgd, &zp, &zb));
1712 }
1713
1714 dr = db->db_last_dirty;
1715 while (dr && dr->dr_txg != txg)
1716 dr = dr->dr_next;
1717
1718 if (dr == NULL) {
1719 /*
1720 * There's no dr for this dbuf, so it must have been freed.
1721 * There's no need to log writes to freed blocks, so we're done.
1722 */
1723 mutex_exit(&db->db_mtx);
1724 return (SET_ERROR(ENOENT));
1725 }
1726
1727 ASSERT(dr->dr_next == NULL || dr->dr_next->dr_txg < txg);
1728
1729 /*
1730 * Assume the on-disk data is X, the current syncing data (in
1731 * txg - 1) is Y, and the current in-memory data is Z (currently
1732 * in dmu_sync).
1733 *
1734 * We usually want to perform a nopwrite if X and Z are the
1735 * same. However, if Y is different (i.e. the BP is going to
1736 * change before this write takes effect), then a nopwrite will
1737 * be incorrect - we would override with X, which could have
1738 * been freed when Y was written.
1739 *
1740 * (Note that this is not a concern when we are nop-writing from
1741 * syncing context, because X and Y must be identical, because
1742 * all previous txgs have been synced.)
1743 *
1744 * Therefore, we disable nopwrite if the current BP could change
1745 * before this TXG. There are two ways it could change: by
1746 * being dirty (dr_next is non-NULL), or by being freed
1747 * (dnode_block_freed()). This behavior is verified by
1748 * zio_done(), which VERIFYs that the override BP is identical
1749 * to the on-disk BP.
1750 */
1751 DB_DNODE_ENTER(db);
1752 dn = DB_DNODE(db);
1753 if (dr->dr_next != NULL || dnode_block_freed(dn, db->db_blkid))
1754 zp.zp_nopwrite = B_FALSE;
1755 DB_DNODE_EXIT(db);
1756
1757 ASSERT(dr->dr_txg == txg);
1758 if (dr->dt.dl.dr_override_state == DR_IN_DMU_SYNC ||
1759 dr->dt.dl.dr_override_state == DR_OVERRIDDEN) {
1760 /*
1761 * We have already issued a sync write for this buffer,
1762 * or this buffer has already been synced. It could not
1763 * have been dirtied since, or we would have cleared the state.
1764 */
1765 mutex_exit(&db->db_mtx);
1766 return (SET_ERROR(EALREADY));
1767 }
1768
1769 ASSERT(dr->dt.dl.dr_override_state == DR_NOT_OVERRIDDEN);
1770 dr->dt.dl.dr_override_state = DR_IN_DMU_SYNC;
1771 mutex_exit(&db->db_mtx);
1772
1773 dsa = kmem_alloc(sizeof (dmu_sync_arg_t), KM_SLEEP);
1774 dsa->dsa_dr = dr;
1775 dsa->dsa_done = done;
1776 dsa->dsa_zgd = zgd;
1777 dsa->dsa_tx = NULL;
1778
1779 zio_nowait(arc_write(pio, os->os_spa, txg,
1780 bp, dr->dt.dl.dr_data, DBUF_IS_L2CACHEABLE(db),
1781 DBUF_IS_L2COMPRESSIBLE(db), &zp, dmu_sync_ready,
1782 NULL, dmu_sync_done, dsa, ZIO_PRIORITY_SYNC_WRITE,
1783 ZIO_FLAG_CANFAIL, &zb));
1784
1785 return (0);
1786 }
1787
1788 int
1789 dmu_object_set_blocksize(objset_t *os, uint64_t object, uint64_t size, int ibs,
1790 dmu_tx_t *tx)
1791 {
1792 dnode_t *dn;
1793 int err;
1794
1795 err = dnode_hold(os, object, FTAG, &dn);
1796 if (err)
1797 return (err);
1798 err = dnode_set_blksz(dn, size, ibs, tx);
1799 dnode_rele(dn, FTAG);
1800 return (err);
1801 }
1802
1803 void
1804 dmu_object_set_checksum(objset_t *os, uint64_t object, uint8_t checksum,
1805 dmu_tx_t *tx)
1806 {
1807 dnode_t *dn;
1808
1809 /*
1810 * Send streams include each object's checksum function. This
1811 * check ensures that the receiving system can understand the
1812 * checksum function transmitted.
1813 */
1814 ASSERT3U(checksum, <, ZIO_CHECKSUM_LEGACY_FUNCTIONS);
1815
1816 VERIFY0(dnode_hold(os, object, FTAG, &dn));
1817 ASSERT3U(checksum, <, ZIO_CHECKSUM_FUNCTIONS);
1818 dn->dn_checksum = checksum;
1819 dnode_setdirty(dn, tx);
1820 dnode_rele(dn, FTAG);
1821 }
1822
1823 void
1824 dmu_object_set_compress(objset_t *os, uint64_t object, uint8_t compress,
1825 dmu_tx_t *tx)
1826 {
1827 dnode_t *dn;
1828
1829 /*
1830 * Send streams include each object's compression function. This
1831 * check ensures that the receiving system can understand the
1832 * compression function transmitted.
1833 */
1834 ASSERT3U(compress, <, ZIO_COMPRESS_LEGACY_FUNCTIONS);
1835
1836 VERIFY0(dnode_hold(os, object, FTAG, &dn));
1837 dn->dn_compress = compress;
1838 dnode_setdirty(dn, tx);
1839 dnode_rele(dn, FTAG);
1840 }
1841
1842 int zfs_mdcomp_disable = 0;
1843
1844 /*
1845 * When the "redundant_metadata" property is set to "most", only indirect
1846 * blocks of this level and higher will have an additional ditto block.
1847 */
1848 int zfs_redundant_metadata_most_ditto_level = 2;
1849
1850 void
1851 dmu_write_policy(objset_t *os, dnode_t *dn, int level, int wp, zio_prop_t *zp)
1852 {
1853 dmu_object_type_t type = dn ? dn->dn_type : DMU_OT_OBJSET;
1854 boolean_t ismd = (level > 0 || DMU_OT_IS_METADATA(type) ||
1855 (wp & WP_SPILL));
1856 enum zio_checksum checksum = os->os_checksum;
1857 enum zio_compress compress = os->os_compress;
1858 enum zio_checksum dedup_checksum = os->os_dedup_checksum;
1859 boolean_t dedup = B_FALSE;
1860 boolean_t nopwrite = B_FALSE;
1861 boolean_t dedup_verify = os->os_dedup_verify;
1862 int copies = os->os_copies;
1863
1864 /*
1865 * We maintain different write policies for each of the following
1866 * types of data:
1867 * 1. metadata
1868 * 2. preallocated blocks (i.e. level-0 blocks of a dump device)
1869 * 3. all other level 0 blocks
1870 */
1871 if (ismd) {
1872 if (zfs_mdcomp_disable) {
1873 compress = ZIO_COMPRESS_EMPTY;
1874 } else {
1875 /*
1876 * XXX -- we should design a compression algorithm
1877 * that specializes in arrays of bps.
1878 */
1879 compress = zio_compress_select(os->os_spa,
1880 ZIO_COMPRESS_ON, ZIO_COMPRESS_ON);
1881 }
1882
1883 /*
1884 * Metadata always gets checksummed. If the data
1885 * checksum is multi-bit correctable, and it's not a
1886 * ZBT-style checksum, then it's suitable for metadata
1887 * as well. Otherwise, the metadata checksum defaults
1888 * to fletcher4.
1889 */
1890 if (zio_checksum_table[checksum].ci_correctable < 1 ||
1891 zio_checksum_table[checksum].ci_eck)
1892 checksum = ZIO_CHECKSUM_FLETCHER_4;
1893
1894 if (os->os_redundant_metadata == ZFS_REDUNDANT_METADATA_ALL ||
1895 (os->os_redundant_metadata ==
1896 ZFS_REDUNDANT_METADATA_MOST &&
1897 (level >= zfs_redundant_metadata_most_ditto_level ||
1898 DMU_OT_IS_METADATA(type) || (wp & WP_SPILL))))
1899 copies++;
1900 } else if (wp & WP_NOFILL) {
1901 ASSERT(level == 0);
1902
1903 /*
1904 * If we're writing preallocated blocks, we aren't actually
1905 * writing them so don't set any policy properties. These
1906 * blocks are currently only used by an external subsystem
1907 * outside of zfs (i.e. dump) and not written by the zio
1908 * pipeline.
1909 */
1910 compress = ZIO_COMPRESS_OFF;
1911 checksum = ZIO_CHECKSUM_OFF;
1912 } else {
1913 compress = zio_compress_select(os->os_spa, dn->dn_compress,
1914 compress);
1915
1916 checksum = (dedup_checksum == ZIO_CHECKSUM_OFF) ?
1917 zio_checksum_select(dn->dn_checksum, checksum) :
1918 dedup_checksum;
1919
1920 /*
1921 * Determine dedup setting. If we are in dmu_sync(),
1922 * we won't actually dedup now because that's all
1923 * done in syncing context; but we do want to use the
1924 * dedup checkum. If the checksum is not strong
1925 * enough to ensure unique signatures, force
1926 * dedup_verify.
1927 */
1928 if (dedup_checksum != ZIO_CHECKSUM_OFF) {
1929 dedup = (wp & WP_DMU_SYNC) ? B_FALSE : B_TRUE;
1930 if (!zio_checksum_table[checksum].ci_dedup)
1931 dedup_verify = B_TRUE;
1932 }
1933
1934 /*
1935 * Enable nopwrite if we have a cryptographically secure
1936 * checksum that has no known collisions (i.e. SHA-256)
1937 * and compression is enabled. We don't enable nopwrite if
1938 * dedup is enabled as the two features are mutually exclusive.
1939 */
1940 nopwrite = (!dedup && zio_checksum_table[checksum].ci_dedup &&
1941 compress != ZIO_COMPRESS_OFF && zfs_nopwrite_enabled);
1942 }
1943
1944 zp->zp_checksum = checksum;
1945 zp->zp_compress = compress;
1946 zp->zp_type = (wp & WP_SPILL) ? dn->dn_bonustype : type;
1947 zp->zp_level = level;
1948 zp->zp_copies = MIN(copies, spa_max_replication(os->os_spa));
1949 zp->zp_dedup = dedup;
1950 zp->zp_dedup_verify = dedup && dedup_verify;
1951 zp->zp_nopwrite = nopwrite;
1952 }
1953
1954 int
1955 dmu_offset_next(objset_t *os, uint64_t object, boolean_t hole, uint64_t *off)
1956 {
1957 dnode_t *dn;
1958 int i, err;
1959
1960 err = dnode_hold(os, object, FTAG, &dn);
1961 if (err)
1962 return (err);
1963 /*
1964 * Sync any current changes before
1965 * we go trundling through the block pointers.
1966 */
1967 for (i = 0; i < TXG_SIZE; i++) {
1968 if (list_link_active(&dn->dn_dirty_link[i]))
1969 break;
1970 }
1971 if (i != TXG_SIZE) {
1972 dnode_rele(dn, FTAG);
1973 txg_wait_synced(dmu_objset_pool(os), 0);
1974 err = dnode_hold(os, object, FTAG, &dn);
1975 if (err)
1976 return (err);
1977 }
1978
1979 err = dnode_next_offset(dn, (hole ? DNODE_FIND_HOLE : 0), off, 1, 1, 0);
1980 dnode_rele(dn, FTAG);
1981
1982 return (err);
1983 }
1984
1985 void
1986 __dmu_object_info_from_dnode(dnode_t *dn, dmu_object_info_t *doi)
1987 {
1988 dnode_phys_t *dnp = dn->dn_phys;
1989 int i;
1990
1991 doi->doi_data_block_size = dn->dn_datablksz;
1992 doi->doi_metadata_block_size = dn->dn_indblkshift ?
1993 1ULL << dn->dn_indblkshift : 0;
1994 doi->doi_type = dn->dn_type;
1995 doi->doi_bonus_type = dn->dn_bonustype;
1996 doi->doi_bonus_size = dn->dn_bonuslen;
1997 doi->doi_indirection = dn->dn_nlevels;
1998 doi->doi_checksum = dn->dn_checksum;
1999 doi->doi_compress = dn->dn_compress;
2000 doi->doi_nblkptr = dn->dn_nblkptr;
2001 doi->doi_physical_blocks_512 = (DN_USED_BYTES(dnp) + 256) >> 9;
2002 doi->doi_max_offset = (dn->dn_maxblkid + 1) * dn->dn_datablksz;
2003 doi->doi_fill_count = 0;
2004 for (i = 0; i < dnp->dn_nblkptr; i++)
2005 doi->doi_fill_count += BP_GET_FILL(&dnp->dn_blkptr[i]);
2006 }
2007
2008 void
2009 dmu_object_info_from_dnode(dnode_t *dn, dmu_object_info_t *doi)
2010 {
2011 rw_enter(&dn->dn_struct_rwlock, RW_READER);
2012 mutex_enter(&dn->dn_mtx);
2013
2014 __dmu_object_info_from_dnode(dn, doi);
2015
2016 mutex_exit(&dn->dn_mtx);
2017 rw_exit(&dn->dn_struct_rwlock);
2018 }
2019
2020 /*
2021 * Get information on a DMU object.
2022 * If doi is NULL, just indicates whether the object exists.
2023 */
2024 int
2025 dmu_object_info(objset_t *os, uint64_t object, dmu_object_info_t *doi)
2026 {
2027 dnode_t *dn;
2028 int err = dnode_hold(os, object, FTAG, &dn);
2029
2030 if (err)
2031 return (err);
2032
2033 if (doi != NULL)
2034 dmu_object_info_from_dnode(dn, doi);
2035
2036 dnode_rele(dn, FTAG);
2037 return (0);
2038 }
2039
2040 /*
2041 * As above, but faster; can be used when you have a held dbuf in hand.
2042 */
2043 void
2044 dmu_object_info_from_db(dmu_buf_t *db_fake, dmu_object_info_t *doi)
2045 {
2046 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
2047
2048 DB_DNODE_ENTER(db);
2049 dmu_object_info_from_dnode(DB_DNODE(db), doi);
2050 DB_DNODE_EXIT(db);
2051 }
2052
2053 /*
2054 * Faster still when you only care about the size.
2055 * This is specifically optimized for zfs_getattr().
2056 */
2057 void
2058 dmu_object_size_from_db(dmu_buf_t *db_fake, uint32_t *blksize,
2059 u_longlong_t *nblk512)
2060 {
2061 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
2062 dnode_t *dn;
2063
2064 DB_DNODE_ENTER(db);
2065 dn = DB_DNODE(db);
2066
2067 *blksize = dn->dn_datablksz;
2068 /* add 1 for dnode space */
2069 *nblk512 = ((DN_USED_BYTES(dn->dn_phys) + SPA_MINBLOCKSIZE/2) >>
2070 SPA_MINBLOCKSHIFT) + 1;
2071 DB_DNODE_EXIT(db);
2072 }
2073
2074 void
2075 byteswap_uint64_array(void *vbuf, size_t size)
2076 {
2077 uint64_t *buf = vbuf;
2078 size_t count = size >> 3;
2079 int i;
2080
2081 ASSERT((size & 7) == 0);
2082
2083 for (i = 0; i < count; i++)
2084 buf[i] = BSWAP_64(buf[i]);
2085 }
2086
2087 void
2088 byteswap_uint32_array(void *vbuf, size_t size)
2089 {
2090 uint32_t *buf = vbuf;
2091 size_t count = size >> 2;
2092 int i;
2093
2094 ASSERT((size & 3) == 0);
2095
2096 for (i = 0; i < count; i++)
2097 buf[i] = BSWAP_32(buf[i]);
2098 }
2099
2100 void
2101 byteswap_uint16_array(void *vbuf, size_t size)
2102 {
2103 uint16_t *buf = vbuf;
2104 size_t count = size >> 1;
2105 int i;
2106
2107 ASSERT((size & 1) == 0);
2108
2109 for (i = 0; i < count; i++)
2110 buf[i] = BSWAP_16(buf[i]);
2111 }
2112
2113 /* ARGSUSED */
2114 void
2115 byteswap_uint8_array(void *vbuf, size_t size)
2116 {
2117 }
2118
2119 void
2120 dmu_init(void)
2121 {
2122 zfs_dbgmsg_init();
2123 sa_cache_init();
2124 xuio_stat_init();
2125 dmu_objset_init();
2126 dnode_init();
2127 dbuf_init();
2128 zfetch_init();
2129 dmu_tx_init();
2130 l2arc_init();
2131 arc_init();
2132 }
2133
2134 void
2135 dmu_fini(void)
2136 {
2137 arc_fini(); /* arc depends on l2arc, so arc must go first */
2138 l2arc_fini();
2139 dmu_tx_fini();
2140 zfetch_fini();
2141 dbuf_fini();
2142 dnode_fini();
2143 dmu_objset_fini();
2144 xuio_stat_fini();
2145 sa_cache_fini();
2146 zfs_dbgmsg_fini();
2147 }
2148
2149 #if defined(_KERNEL) && defined(HAVE_SPL)
2150 EXPORT_SYMBOL(dmu_bonus_hold);
2151 EXPORT_SYMBOL(dmu_buf_hold_array_by_bonus);
2152 EXPORT_SYMBOL(dmu_buf_rele_array);
2153 EXPORT_SYMBOL(dmu_prefetch);
2154 EXPORT_SYMBOL(dmu_free_range);
2155 EXPORT_SYMBOL(dmu_free_long_range);
2156 EXPORT_SYMBOL(dmu_free_long_object);
2157 EXPORT_SYMBOL(dmu_read);
2158 EXPORT_SYMBOL(dmu_write);
2159 EXPORT_SYMBOL(dmu_prealloc);
2160 EXPORT_SYMBOL(dmu_object_info);
2161 EXPORT_SYMBOL(dmu_object_info_from_dnode);
2162 EXPORT_SYMBOL(dmu_object_info_from_db);
2163 EXPORT_SYMBOL(dmu_object_size_from_db);
2164 EXPORT_SYMBOL(dmu_object_set_blocksize);
2165 EXPORT_SYMBOL(dmu_object_set_checksum);
2166 EXPORT_SYMBOL(dmu_object_set_compress);
2167 EXPORT_SYMBOL(dmu_write_policy);
2168 EXPORT_SYMBOL(dmu_sync);
2169 EXPORT_SYMBOL(dmu_request_arcbuf);
2170 EXPORT_SYMBOL(dmu_return_arcbuf);
2171 EXPORT_SYMBOL(dmu_assign_arcbuf);
2172 EXPORT_SYMBOL(dmu_buf_hold);
2173 EXPORT_SYMBOL(dmu_ot);
2174
2175 module_param(zfs_mdcomp_disable, int, 0644);
2176 MODULE_PARM_DESC(zfs_mdcomp_disable, "Disable meta data compression");
2177
2178 module_param(zfs_nopwrite_enabled, int, 0644);
2179 MODULE_PARM_DESC(zfs_nopwrite_enabled, "Enable NOP writes");
2180
2181 #endif
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