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 2015 Nexenta Systems, Inc. All rights reserved.
24 * Copyright (c) 2012, 2017 by Delphix. All rights reserved.
25 * Copyright (c) 2014 Spectra Logic Corporation, All rights reserved.
26 * Copyright (c) 2014 Integros [integros.com]
27 * Copyright 2017 RackTop Systems.
28 */
29
30 #include <sys/zfs_context.h>
31 #include <sys/dbuf.h>
32 #include <sys/dnode.h>
33 #include <sys/dmu.h>
34 #include <sys/dmu_impl.h>
35 #include <sys/dmu_tx.h>
36 #include <sys/dmu_objset.h>
37 #include <sys/dsl_dir.h>
38 #include <sys/dsl_dataset.h>
39 #include <sys/spa.h>
40 #include <sys/zio.h>
41 #include <sys/dmu_zfetch.h>
42 #include <sys/range_tree.h>
43
44 static void smartcomp_check_comp(dnode_smartcomp_t *sc);
45
46 static kmem_cache_t *dnode_cache;
47 /*
48 * Define DNODE_STATS to turn on statistic gathering. By default, it is only
49 * turned on when DEBUG is also defined.
50 */
51 #ifdef DEBUG
52 #define DNODE_STATS
53 #endif /* DEBUG */
54
55 #ifdef DNODE_STATS
56 #define DNODE_STAT_ADD(stat) ((stat)++)
57 #else
58 #define DNODE_STAT_ADD(stat) /* nothing */
59 #endif /* DNODE_STATS */
60
61 static dnode_phys_t dnode_phys_zero;
62
63 int zfs_default_bs = SPA_MINBLOCKSHIFT;
64 int zfs_default_ibs = DN_DFL_INDBLKSHIFT;
65
66 #ifdef _KERNEL
67 static kmem_cbrc_t dnode_move(void *, void *, size_t, void *);
68 #endif /* _KERNEL */
69
70 static int
71 dbuf_compare(const void *x1, const void *x2)
72 {
73 const dmu_buf_impl_t *d1 = x1;
74 const dmu_buf_impl_t *d2 = x2;
75
76 if (d1->db_level < d2->db_level) {
77 return (-1);
78 }
79 if (d1->db_level > d2->db_level) {
80 return (1);
81 }
82
83 if (d1->db_blkid < d2->db_blkid) {
84 return (-1);
85 }
86 if (d1->db_blkid > d2->db_blkid) {
87 return (1);
88 }
89
90 if (d1->db_state == DB_SEARCH) {
91 ASSERT3S(d2->db_state, !=, DB_SEARCH);
92 return (-1);
93 } else if (d2->db_state == DB_SEARCH) {
94 ASSERT3S(d1->db_state, !=, DB_SEARCH);
95 return (1);
96 }
97
98 if ((uintptr_t)d1 < (uintptr_t)d2) {
99 return (-1);
100 }
101 if ((uintptr_t)d1 > (uintptr_t)d2) {
102 return (1);
103 }
104 return (0);
105 }
106
107 /* ARGSUSED */
108 static int
109 dnode_cons(void *arg, void *unused, int kmflag)
110 {
111 dnode_t *dn = arg;
112 int i;
113
114 rw_init(&dn->dn_struct_rwlock, NULL, RW_DEFAULT, NULL);
115 mutex_init(&dn->dn_mtx, NULL, MUTEX_DEFAULT, NULL);
116 mutex_init(&dn->dn_dbufs_mtx, NULL, MUTEX_DEFAULT, NULL);
117 cv_init(&dn->dn_notxholds, NULL, CV_DEFAULT, NULL);
118
119 /*
120 * Every dbuf has a reference, and dropping a tracked reference is
121 * O(number of references), so don't track dn_holds.
122 */
123 refcount_create_untracked(&dn->dn_holds);
124 refcount_create(&dn->dn_tx_holds);
125 list_link_init(&dn->dn_link);
126
127 bzero(&dn->dn_next_nblkptr[0], sizeof (dn->dn_next_nblkptr));
128 bzero(&dn->dn_next_nlevels[0], sizeof (dn->dn_next_nlevels));
129 bzero(&dn->dn_next_indblkshift[0], sizeof (dn->dn_next_indblkshift));
130 bzero(&dn->dn_next_bonustype[0], sizeof (dn->dn_next_bonustype));
131 bzero(&dn->dn_rm_spillblk[0], sizeof (dn->dn_rm_spillblk));
132 bzero(&dn->dn_next_bonuslen[0], sizeof (dn->dn_next_bonuslen));
133 bzero(&dn->dn_next_blksz[0], sizeof (dn->dn_next_blksz));
134
135 for (i = 0; i < TXG_SIZE; i++) {
136 list_link_init(&dn->dn_dirty_link[i]);
137 dn->dn_free_ranges[i] = NULL;
138 list_create(&dn->dn_dirty_records[i],
139 sizeof (dbuf_dirty_record_t),
140 offsetof(dbuf_dirty_record_t, dr_dirty_node));
141 }
142
143 dn->dn_allocated_txg = 0;
144 dn->dn_free_txg = 0;
145 dn->dn_assigned_txg = 0;
146 dn->dn_dirtyctx = 0;
147 dn->dn_dirtyctx_firstset = NULL;
148 dn->dn_bonus = NULL;
149 dn->dn_have_spill = B_FALSE;
150 dn->dn_zio = NULL;
151 dn->dn_oldused = 0;
152 dn->dn_oldflags = 0;
153 dn->dn_olduid = 0;
154 dn->dn_oldgid = 0;
155 dn->dn_newuid = 0;
156 dn->dn_newgid = 0;
157 dn->dn_id_flags = 0;
158
159 dn->dn_dbufs_count = 0;
160 avl_create(&dn->dn_dbufs, dbuf_compare, sizeof (dmu_buf_impl_t),
161 offsetof(dmu_buf_impl_t, db_link));
162
163 dn->dn_moved = 0;
164
165 bzero(&dn->dn_smartcomp, sizeof (dn->dn_smartcomp));
166 mutex_init(&dn->dn_smartcomp.sc_lock, NULL, MUTEX_DEFAULT, NULL);
167
168 return (0);
169 }
170
171 /* ARGSUSED */
172 static void
173 dnode_dest(void *arg, void *unused)
174 {
175 int i;
176 dnode_t *dn = arg;
177
178 mutex_destroy(&dn->dn_smartcomp.sc_lock);
179
180 rw_destroy(&dn->dn_struct_rwlock);
181 mutex_destroy(&dn->dn_mtx);
182 mutex_destroy(&dn->dn_dbufs_mtx);
183 cv_destroy(&dn->dn_notxholds);
184 refcount_destroy(&dn->dn_holds);
185 refcount_destroy(&dn->dn_tx_holds);
186 ASSERT(!list_link_active(&dn->dn_link));
187
188 for (i = 0; i < TXG_SIZE; i++) {
189 ASSERT(!list_link_active(&dn->dn_dirty_link[i]));
190 ASSERT3P(dn->dn_free_ranges[i], ==, NULL);
191 list_destroy(&dn->dn_dirty_records[i]);
192 ASSERT0(dn->dn_next_nblkptr[i]);
193 ASSERT0(dn->dn_next_nlevels[i]);
194 ASSERT0(dn->dn_next_indblkshift[i]);
195 ASSERT0(dn->dn_next_bonustype[i]);
196 ASSERT0(dn->dn_rm_spillblk[i]);
197 ASSERT0(dn->dn_next_bonuslen[i]);
198 ASSERT0(dn->dn_next_blksz[i]);
199 }
200
201 ASSERT0(dn->dn_allocated_txg);
202 ASSERT0(dn->dn_free_txg);
203 ASSERT0(dn->dn_assigned_txg);
204 ASSERT0(dn->dn_dirtyctx);
205 ASSERT3P(dn->dn_dirtyctx_firstset, ==, NULL);
206 ASSERT3P(dn->dn_bonus, ==, NULL);
207 ASSERT(!dn->dn_have_spill);
208 ASSERT3P(dn->dn_zio, ==, NULL);
209 ASSERT0(dn->dn_oldused);
210 ASSERT0(dn->dn_oldflags);
211 ASSERT0(dn->dn_olduid);
212 ASSERT0(dn->dn_oldgid);
213 ASSERT0(dn->dn_newuid);
214 ASSERT0(dn->dn_newgid);
215 ASSERT0(dn->dn_id_flags);
216
217 ASSERT0(dn->dn_dbufs_count);
218 avl_destroy(&dn->dn_dbufs);
219 }
220
221 void
222 dnode_init(void)
223 {
224 ASSERT(dnode_cache == NULL);
225 dnode_cache = kmem_cache_create("dnode_t",
226 sizeof (dnode_t),
227 0, dnode_cons, dnode_dest, NULL, NULL, NULL, 0);
228 #ifdef _KERNEL
229 kmem_cache_set_move(dnode_cache, dnode_move);
230 #endif /* _KERNEL */
231 }
232
233 void
234 dnode_fini(void)
235 {
236 kmem_cache_destroy(dnode_cache);
237 dnode_cache = NULL;
238 }
239
240
241 #ifdef ZFS_DEBUG
242 void
243 dnode_verify(dnode_t *dn)
244 {
245 int drop_struct_lock = FALSE;
246
247 ASSERT(dn->dn_phys);
248 ASSERT(dn->dn_objset);
249 ASSERT(dn->dn_handle->dnh_dnode == dn);
250
251 ASSERT(DMU_OT_IS_VALID(dn->dn_phys->dn_type));
252
253 if (!(zfs_flags & ZFS_DEBUG_DNODE_VERIFY))
254 return;
255
256 if (!RW_WRITE_HELD(&dn->dn_struct_rwlock)) {
257 rw_enter(&dn->dn_struct_rwlock, RW_READER);
258 drop_struct_lock = TRUE;
259 }
260 if (dn->dn_phys->dn_type != DMU_OT_NONE || dn->dn_allocated_txg != 0) {
261 int i;
262 ASSERT3U(dn->dn_indblkshift, >=, 0);
263 ASSERT3U(dn->dn_indblkshift, <=, SPA_MAXBLOCKSHIFT);
264 if (dn->dn_datablkshift) {
265 ASSERT3U(dn->dn_datablkshift, >=, SPA_MINBLOCKSHIFT);
266 ASSERT3U(dn->dn_datablkshift, <=, SPA_MAXBLOCKSHIFT);
267 ASSERT3U(1<<dn->dn_datablkshift, ==, dn->dn_datablksz);
268 }
269 ASSERT3U(dn->dn_nlevels, <=, 30);
270 ASSERT(DMU_OT_IS_VALID(dn->dn_type));
271 ASSERT3U(dn->dn_nblkptr, >=, 1);
272 ASSERT3U(dn->dn_nblkptr, <=, DN_MAX_NBLKPTR);
273 ASSERT3U(dn->dn_bonuslen, <=, DN_MAX_BONUSLEN);
274 ASSERT3U(dn->dn_datablksz, ==,
275 dn->dn_datablkszsec << SPA_MINBLOCKSHIFT);
276 ASSERT3U(ISP2(dn->dn_datablksz), ==, dn->dn_datablkshift != 0);
277 ASSERT3U((dn->dn_nblkptr - 1) * sizeof (blkptr_t) +
278 dn->dn_bonuslen, <=, DN_MAX_BONUSLEN);
279 for (i = 0; i < TXG_SIZE; i++) {
280 ASSERT3U(dn->dn_next_nlevels[i], <=, dn->dn_nlevels);
281 }
282 }
283 if (dn->dn_phys->dn_type != DMU_OT_NONE)
284 ASSERT3U(dn->dn_phys->dn_nlevels, <=, dn->dn_nlevels);
285 ASSERT(DMU_OBJECT_IS_SPECIAL(dn->dn_object) || dn->dn_dbuf != NULL);
286 if (dn->dn_dbuf != NULL) {
287 ASSERT3P(dn->dn_phys, ==,
288 (dnode_phys_t *)dn->dn_dbuf->db.db_data +
289 (dn->dn_object % (dn->dn_dbuf->db.db_size >> DNODE_SHIFT)));
290 }
291 if (drop_struct_lock)
292 rw_exit(&dn->dn_struct_rwlock);
293 }
294 #endif
295
296 void
297 dnode_byteswap(dnode_phys_t *dnp)
298 {
299 uint64_t *buf64 = (void*)&dnp->dn_blkptr;
300 int i;
301
302 if (dnp->dn_type == DMU_OT_NONE) {
303 bzero(dnp, sizeof (dnode_phys_t));
304 return;
305 }
306
307 dnp->dn_datablkszsec = BSWAP_16(dnp->dn_datablkszsec);
308 dnp->dn_bonuslen = BSWAP_16(dnp->dn_bonuslen);
309 dnp->dn_maxblkid = BSWAP_64(dnp->dn_maxblkid);
310 dnp->dn_used = BSWAP_64(dnp->dn_used);
311
312 /*
313 * dn_nblkptr is only one byte, so it's OK to read it in either
314 * byte order. We can't read dn_bouslen.
315 */
316 ASSERT(dnp->dn_indblkshift <= SPA_MAXBLOCKSHIFT);
317 ASSERT(dnp->dn_nblkptr <= DN_MAX_NBLKPTR);
318 for (i = 0; i < dnp->dn_nblkptr * sizeof (blkptr_t)/8; i++)
319 buf64[i] = BSWAP_64(buf64[i]);
320
321 /*
322 * OK to check dn_bonuslen for zero, because it won't matter if
323 * we have the wrong byte order. This is necessary because the
324 * dnode dnode is smaller than a regular dnode.
325 */
326 if (dnp->dn_bonuslen != 0) {
327 /*
328 * Note that the bonus length calculated here may be
329 * longer than the actual bonus buffer. This is because
330 * we always put the bonus buffer after the last block
331 * pointer (instead of packing it against the end of the
332 * dnode buffer).
333 */
334 int off = (dnp->dn_nblkptr-1) * sizeof (blkptr_t);
335 size_t len = DN_MAX_BONUSLEN - off;
336 ASSERT(DMU_OT_IS_VALID(dnp->dn_bonustype));
337 dmu_object_byteswap_t byteswap =
338 DMU_OT_BYTESWAP(dnp->dn_bonustype);
339 dmu_ot_byteswap[byteswap].ob_func(dnp->dn_bonus + off, len);
340 }
341
342 /* Swap SPILL block if we have one */
343 if (dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR)
344 byteswap_uint64_array(&dnp->dn_spill, sizeof (blkptr_t));
345
346 }
347
348 void
349 dnode_buf_byteswap(void *vbuf, size_t size)
350 {
351 dnode_phys_t *buf = vbuf;
352 int i;
353
354 ASSERT3U(sizeof (dnode_phys_t), ==, (1<<DNODE_SHIFT));
355 ASSERT((size & (sizeof (dnode_phys_t)-1)) == 0);
356
357 size >>= DNODE_SHIFT;
358 for (i = 0; i < size; i++) {
359 dnode_byteswap(buf);
360 buf++;
361 }
362 }
363
364 void
365 dnode_setbonuslen(dnode_t *dn, int newsize, dmu_tx_t *tx)
366 {
367 ASSERT3U(refcount_count(&dn->dn_holds), >=, 1);
368
369 dnode_setdirty(dn, tx);
370 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
371 ASSERT3U(newsize, <=, DN_MAX_BONUSLEN -
372 (dn->dn_nblkptr-1) * sizeof (blkptr_t));
373 dn->dn_bonuslen = newsize;
374 if (newsize == 0)
375 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = DN_ZERO_BONUSLEN;
376 else
377 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = dn->dn_bonuslen;
378 rw_exit(&dn->dn_struct_rwlock);
379 }
380
381 void
382 dnode_setbonus_type(dnode_t *dn, dmu_object_type_t newtype, dmu_tx_t *tx)
383 {
384 ASSERT3U(refcount_count(&dn->dn_holds), >=, 1);
385 dnode_setdirty(dn, tx);
386 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
387 dn->dn_bonustype = newtype;
388 dn->dn_next_bonustype[tx->tx_txg & TXG_MASK] = dn->dn_bonustype;
389 rw_exit(&dn->dn_struct_rwlock);
390 }
391
392 void
393 dnode_rm_spill(dnode_t *dn, dmu_tx_t *tx)
394 {
395 ASSERT3U(refcount_count(&dn->dn_holds), >=, 1);
396 ASSERT(RW_WRITE_HELD(&dn->dn_struct_rwlock));
397 dnode_setdirty(dn, tx);
398 dn->dn_rm_spillblk[tx->tx_txg&TXG_MASK] = DN_KILL_SPILLBLK;
399 dn->dn_have_spill = B_FALSE;
400 }
401
402 static void
403 dnode_setdblksz(dnode_t *dn, int size)
404 {
405 ASSERT0(P2PHASE(size, SPA_MINBLOCKSIZE));
406 ASSERT3U(size, <=, SPA_MAXBLOCKSIZE);
407 ASSERT3U(size, >=, SPA_MINBLOCKSIZE);
408 ASSERT3U(size >> SPA_MINBLOCKSHIFT, <,
409 1<<(sizeof (dn->dn_phys->dn_datablkszsec) * 8));
410 dn->dn_datablksz = size;
411 dn->dn_datablkszsec = size >> SPA_MINBLOCKSHIFT;
412 dn->dn_datablkshift = ISP2(size) ? highbit64(size - 1) : 0;
413 }
414
415 static dnode_t *
416 dnode_create(objset_t *os, dnode_phys_t *dnp, dmu_buf_impl_t *db,
417 uint64_t object, dnode_handle_t *dnh)
418 {
419 dnode_t *dn;
420
421 dn = kmem_cache_alloc(dnode_cache, KM_SLEEP);
422 #ifdef _KERNEL
423 ASSERT(!POINTER_IS_VALID(dn->dn_objset));
424 #endif /* _KERNEL */
425 dn->dn_moved = 0;
426
427 /*
428 * Defer setting dn_objset until the dnode is ready to be a candidate
429 * for the dnode_move() callback.
430 */
431 dn->dn_object = object;
432 dn->dn_dbuf = db;
433 dn->dn_handle = dnh;
434 dn->dn_phys = dnp;
435
436 if (dnp->dn_datablkszsec) {
437 dnode_setdblksz(dn, dnp->dn_datablkszsec << SPA_MINBLOCKSHIFT);
438 } else {
439 dn->dn_datablksz = 0;
440 dn->dn_datablkszsec = 0;
441 dn->dn_datablkshift = 0;
442 }
443 dn->dn_indblkshift = dnp->dn_indblkshift;
444 dn->dn_nlevels = dnp->dn_nlevels;
445 dn->dn_type = dnp->dn_type;
446 dn->dn_nblkptr = dnp->dn_nblkptr;
447 dn->dn_checksum = dnp->dn_checksum;
448 dn->dn_compress = dnp->dn_compress;
449 dn->dn_bonustype = dnp->dn_bonustype;
450 dn->dn_bonuslen = dnp->dn_bonuslen;
451 dn->dn_maxblkid = dnp->dn_maxblkid;
452 dn->dn_have_spill = ((dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) != 0);
453 dn->dn_id_flags = 0;
454
455 dmu_zfetch_init(&dn->dn_zfetch, dn);
456
457 ASSERT(DMU_OT_IS_VALID(dn->dn_phys->dn_type));
458
459 mutex_enter(&os->os_lock);
460 if (dnh->dnh_dnode != NULL) {
461 /* Lost the allocation race. */
462 mutex_exit(&os->os_lock);
463 kmem_cache_free(dnode_cache, dn);
464 return (dnh->dnh_dnode);
465 }
466
467 /*
468 * Exclude special dnodes from os_dnodes so an empty os_dnodes
469 * signifies that the special dnodes have no references from
470 * their children (the entries in os_dnodes). This allows
471 * dnode_destroy() to easily determine if the last child has
472 * been removed and then complete eviction of the objset.
473 */
474 if (!DMU_OBJECT_IS_SPECIAL(object))
475 list_insert_head(&os->os_dnodes, dn);
476 membar_producer();
477
478 /*
479 * Everything else must be valid before assigning dn_objset
480 * makes the dnode eligible for dnode_move().
481 */
482 dn->dn_objset = os;
483
484 dnh->dnh_dnode = dn;
485 mutex_exit(&os->os_lock);
486
487 arc_space_consume(sizeof (dnode_t), ARC_SPACE_OTHER);
488 return (dn);
489 }
490
491 /*
492 * Caller must be holding the dnode handle, which is released upon return.
493 */
494 static void
495 dnode_destroy(dnode_t *dn)
496 {
497 objset_t *os = dn->dn_objset;
498 boolean_t complete_os_eviction = B_FALSE;
499
500 ASSERT((dn->dn_id_flags & DN_ID_NEW_EXIST) == 0);
501
502 mutex_enter(&os->os_lock);
503 POINTER_INVALIDATE(&dn->dn_objset);
504 if (!DMU_OBJECT_IS_SPECIAL(dn->dn_object)) {
505 list_remove(&os->os_dnodes, dn);
506 complete_os_eviction =
507 list_is_empty(&os->os_dnodes) &&
508 list_link_active(&os->os_evicting_node);
509 }
510 mutex_exit(&os->os_lock);
511
512 /* the dnode can no longer move, so we can release the handle */
513 zrl_remove(&dn->dn_handle->dnh_zrlock);
514
515 dn->dn_allocated_txg = 0;
516 dn->dn_free_txg = 0;
517 dn->dn_assigned_txg = 0;
518
519 dn->dn_dirtyctx = 0;
520 if (dn->dn_dirtyctx_firstset != NULL) {
521 kmem_free(dn->dn_dirtyctx_firstset, 1);
522 dn->dn_dirtyctx_firstset = NULL;
523 }
524 if (dn->dn_bonus != NULL) {
525 mutex_enter(&dn->dn_bonus->db_mtx);
526 dbuf_destroy(dn->dn_bonus);
527 dn->dn_bonus = NULL;
528 }
529 dn->dn_zio = NULL;
530
531 dn->dn_have_spill = B_FALSE;
532 dn->dn_oldused = 0;
533 dn->dn_oldflags = 0;
534 dn->dn_olduid = 0;
535 dn->dn_oldgid = 0;
536 dn->dn_newuid = 0;
537 dn->dn_newgid = 0;
538 dn->dn_id_flags = 0;
539
540 dmu_zfetch_fini(&dn->dn_zfetch);
541 kmem_cache_free(dnode_cache, dn);
542 arc_space_return(sizeof (dnode_t), ARC_SPACE_OTHER);
543
544 if (complete_os_eviction)
545 dmu_objset_evict_done(os);
546 }
547
548 void
549 dnode_allocate(dnode_t *dn, dmu_object_type_t ot, int blocksize, int ibs,
550 dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx)
551 {
552 int i;
553
554 ASSERT3U(blocksize, <=,
555 spa_maxblocksize(dmu_objset_spa(dn->dn_objset)));
556 if (blocksize == 0)
557 blocksize = 1 << zfs_default_bs;
558 else
559 blocksize = P2ROUNDUP(blocksize, SPA_MINBLOCKSIZE);
560
561 if (ibs == 0)
562 ibs = zfs_default_ibs;
563
564 ibs = MIN(MAX(ibs, DN_MIN_INDBLKSHIFT), DN_MAX_INDBLKSHIFT);
565
566 dprintf("os=%p obj=%llu txg=%llu blocksize=%d ibs=%d\n", dn->dn_objset,
567 dn->dn_object, tx->tx_txg, blocksize, ibs);
568
569 ASSERT(dn->dn_type == DMU_OT_NONE);
570 ASSERT(bcmp(dn->dn_phys, &dnode_phys_zero, sizeof (dnode_phys_t)) == 0);
571 ASSERT(dn->dn_phys->dn_type == DMU_OT_NONE);
572 ASSERT(ot != DMU_OT_NONE);
573 ASSERT(DMU_OT_IS_VALID(ot));
574 ASSERT((bonustype == DMU_OT_NONE && bonuslen == 0) ||
575 (bonustype == DMU_OT_SA && bonuslen == 0) ||
576 (bonustype != DMU_OT_NONE && bonuslen != 0));
577 ASSERT(DMU_OT_IS_VALID(bonustype));
578 ASSERT3U(bonuslen, <=, DN_MAX_BONUSLEN);
579 ASSERT(dn->dn_type == DMU_OT_NONE);
580 ASSERT0(dn->dn_maxblkid);
581 ASSERT0(dn->dn_allocated_txg);
582 ASSERT0(dn->dn_assigned_txg);
583 ASSERT(refcount_is_zero(&dn->dn_tx_holds));
584 ASSERT3U(refcount_count(&dn->dn_holds), <=, 1);
585 ASSERT(avl_is_empty(&dn->dn_dbufs));
586
587 for (i = 0; i < TXG_SIZE; i++) {
588 ASSERT0(dn->dn_next_nblkptr[i]);
589 ASSERT0(dn->dn_next_nlevels[i]);
590 ASSERT0(dn->dn_next_indblkshift[i]);
591 ASSERT0(dn->dn_next_bonuslen[i]);
592 ASSERT0(dn->dn_next_bonustype[i]);
593 ASSERT0(dn->dn_rm_spillblk[i]);
594 ASSERT0(dn->dn_next_blksz[i]);
595 ASSERT(!list_link_active(&dn->dn_dirty_link[i]));
596 ASSERT3P(list_head(&dn->dn_dirty_records[i]), ==, NULL);
597 ASSERT3P(dn->dn_free_ranges[i], ==, NULL);
598 }
599
600 dn->dn_type = ot;
601 dnode_setdblksz(dn, blocksize);
602 dn->dn_indblkshift = ibs;
603 dn->dn_nlevels = 1;
604 if (bonustype == DMU_OT_SA) /* Maximize bonus space for SA */
605 dn->dn_nblkptr = 1;
606 else
607 dn->dn_nblkptr = 1 +
608 ((DN_MAX_BONUSLEN - bonuslen) >> SPA_BLKPTRSHIFT);
609 dn->dn_bonustype = bonustype;
610 dn->dn_bonuslen = bonuslen;
611 dn->dn_checksum = ZIO_CHECKSUM_INHERIT;
612 dn->dn_compress = ZIO_COMPRESS_INHERIT;
613 dn->dn_dirtyctx = 0;
614
615 dn->dn_free_txg = 0;
616 if (dn->dn_dirtyctx_firstset) {
617 kmem_free(dn->dn_dirtyctx_firstset, 1);
618 dn->dn_dirtyctx_firstset = NULL;
619 }
620
621 dn->dn_allocated_txg = tx->tx_txg;
622 dn->dn_id_flags = 0;
623
624 dnode_setdirty(dn, tx);
625 dn->dn_next_indblkshift[tx->tx_txg & TXG_MASK] = ibs;
626 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = dn->dn_bonuslen;
627 dn->dn_next_bonustype[tx->tx_txg & TXG_MASK] = dn->dn_bonustype;
628 dn->dn_next_blksz[tx->tx_txg & TXG_MASK] = dn->dn_datablksz;
629 }
630
631 void
632 dnode_reallocate(dnode_t *dn, dmu_object_type_t ot, int blocksize,
633 dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx)
634 {
635 int nblkptr;
636
637 ASSERT3U(blocksize, >=, SPA_MINBLOCKSIZE);
638 ASSERT3U(blocksize, <=,
639 spa_maxblocksize(dmu_objset_spa(dn->dn_objset)));
640 ASSERT0(blocksize % SPA_MINBLOCKSIZE);
641 ASSERT(dn->dn_object != DMU_META_DNODE_OBJECT || dmu_tx_private_ok(tx));
642 ASSERT(tx->tx_txg != 0);
643 ASSERT((bonustype == DMU_OT_NONE && bonuslen == 0) ||
644 (bonustype != DMU_OT_NONE && bonuslen != 0) ||
645 (bonustype == DMU_OT_SA && bonuslen == 0));
646 ASSERT(DMU_OT_IS_VALID(bonustype));
647 ASSERT3U(bonuslen, <=, DN_MAX_BONUSLEN);
648
649 /* clean up any unreferenced dbufs */
650 dnode_evict_dbufs(dn, DBUF_EVICT_ALL);
651
652 dn->dn_id_flags = 0;
653
654 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
655 dnode_setdirty(dn, tx);
656 if (dn->dn_datablksz != blocksize) {
657 /* change blocksize */
658 ASSERT(dn->dn_maxblkid == 0 &&
659 (BP_IS_HOLE(&dn->dn_phys->dn_blkptr[0]) ||
660 dnode_block_freed(dn, 0)));
661 dnode_setdblksz(dn, blocksize);
662 dn->dn_next_blksz[tx->tx_txg&TXG_MASK] = blocksize;
663 }
664 if (dn->dn_bonuslen != bonuslen)
665 dn->dn_next_bonuslen[tx->tx_txg&TXG_MASK] = bonuslen;
666
667 if (bonustype == DMU_OT_SA) /* Maximize bonus space for SA */
668 nblkptr = 1;
669 else
670 nblkptr = 1 + ((DN_MAX_BONUSLEN - bonuslen) >> SPA_BLKPTRSHIFT);
671 if (dn->dn_bonustype != bonustype)
672 dn->dn_next_bonustype[tx->tx_txg&TXG_MASK] = bonustype;
673 if (dn->dn_nblkptr != nblkptr)
674 dn->dn_next_nblkptr[tx->tx_txg&TXG_MASK] = nblkptr;
675 if (dn->dn_phys->dn_flags & DNODE_FLAG_SPILL_BLKPTR) {
676 dbuf_rm_spill(dn, tx);
677 dnode_rm_spill(dn, tx);
678 }
679 rw_exit(&dn->dn_struct_rwlock);
680
681 /* change type */
682 dn->dn_type = ot;
683
684 /* change bonus size and type */
685 mutex_enter(&dn->dn_mtx);
686 dn->dn_bonustype = bonustype;
687 dn->dn_bonuslen = bonuslen;
688 dn->dn_nblkptr = nblkptr;
689 dn->dn_checksum = ZIO_CHECKSUM_INHERIT;
690 dn->dn_compress = ZIO_COMPRESS_INHERIT;
691 ASSERT3U(dn->dn_nblkptr, <=, DN_MAX_NBLKPTR);
692
693 /* fix up the bonus db_size */
694 if (dn->dn_bonus) {
695 dn->dn_bonus->db.db_size =
696 DN_MAX_BONUSLEN - (dn->dn_nblkptr-1) * sizeof (blkptr_t);
697 ASSERT(dn->dn_bonuslen <= dn->dn_bonus->db.db_size);
698 }
699
700 dn->dn_allocated_txg = tx->tx_txg;
701 mutex_exit(&dn->dn_mtx);
702 }
703
704 #ifdef DNODE_STATS
705 static struct {
706 uint64_t dms_dnode_invalid;
707 uint64_t dms_dnode_recheck1;
708 uint64_t dms_dnode_recheck2;
709 uint64_t dms_dnode_special;
710 uint64_t dms_dnode_handle;
711 uint64_t dms_dnode_rwlock;
712 uint64_t dms_dnode_active;
713 } dnode_move_stats;
714 #endif /* DNODE_STATS */
715
716 #ifdef _KERNEL
717 static void
718 dnode_move_impl(dnode_t *odn, dnode_t *ndn)
719 {
720 int i;
721
722 ASSERT(!RW_LOCK_HELD(&odn->dn_struct_rwlock));
723 ASSERT(MUTEX_NOT_HELD(&odn->dn_mtx));
724 ASSERT(MUTEX_NOT_HELD(&odn->dn_dbufs_mtx));
725 ASSERT(!RW_LOCK_HELD(&odn->dn_zfetch.zf_rwlock));
726
727 /* Copy fields. */
728 ndn->dn_objset = odn->dn_objset;
729 ndn->dn_object = odn->dn_object;
730 ndn->dn_dbuf = odn->dn_dbuf;
731 ndn->dn_handle = odn->dn_handle;
732 ndn->dn_phys = odn->dn_phys;
733 ndn->dn_type = odn->dn_type;
734 ndn->dn_bonuslen = odn->dn_bonuslen;
735 ndn->dn_bonustype = odn->dn_bonustype;
736 ndn->dn_nblkptr = odn->dn_nblkptr;
737 ndn->dn_checksum = odn->dn_checksum;
738 ndn->dn_compress = odn->dn_compress;
739 ndn->dn_nlevels = odn->dn_nlevels;
740 ndn->dn_indblkshift = odn->dn_indblkshift;
741 ndn->dn_datablkshift = odn->dn_datablkshift;
742 ndn->dn_datablkszsec = odn->dn_datablkszsec;
743 ndn->dn_datablksz = odn->dn_datablksz;
744 ndn->dn_maxblkid = odn->dn_maxblkid;
745 bcopy(&odn->dn_next_nblkptr[0], &ndn->dn_next_nblkptr[0],
746 sizeof (odn->dn_next_nblkptr));
747 bcopy(&odn->dn_next_nlevels[0], &ndn->dn_next_nlevels[0],
748 sizeof (odn->dn_next_nlevels));
749 bcopy(&odn->dn_next_indblkshift[0], &ndn->dn_next_indblkshift[0],
750 sizeof (odn->dn_next_indblkshift));
751 bcopy(&odn->dn_next_bonustype[0], &ndn->dn_next_bonustype[0],
752 sizeof (odn->dn_next_bonustype));
753 bcopy(&odn->dn_rm_spillblk[0], &ndn->dn_rm_spillblk[0],
754 sizeof (odn->dn_rm_spillblk));
755 bcopy(&odn->dn_next_bonuslen[0], &ndn->dn_next_bonuslen[0],
756 sizeof (odn->dn_next_bonuslen));
757 bcopy(&odn->dn_next_blksz[0], &ndn->dn_next_blksz[0],
758 sizeof (odn->dn_next_blksz));
759 for (i = 0; i < TXG_SIZE; i++) {
760 list_move_tail(&ndn->dn_dirty_records[i],
761 &odn->dn_dirty_records[i]);
762 }
763 bcopy(&odn->dn_free_ranges[0], &ndn->dn_free_ranges[0],
764 sizeof (odn->dn_free_ranges));
765 ndn->dn_allocated_txg = odn->dn_allocated_txg;
766 ndn->dn_free_txg = odn->dn_free_txg;
767 ndn->dn_assigned_txg = odn->dn_assigned_txg;
768 ndn->dn_dirtyctx = odn->dn_dirtyctx;
769 ndn->dn_dirtyctx_firstset = odn->dn_dirtyctx_firstset;
770 ASSERT(refcount_count(&odn->dn_tx_holds) == 0);
771 refcount_transfer(&ndn->dn_holds, &odn->dn_holds);
772 ASSERT(avl_is_empty(&ndn->dn_dbufs));
773 avl_swap(&ndn->dn_dbufs, &odn->dn_dbufs);
774 ndn->dn_dbufs_count = odn->dn_dbufs_count;
775 ndn->dn_bonus = odn->dn_bonus;
776 ndn->dn_have_spill = odn->dn_have_spill;
777 ndn->dn_zio = odn->dn_zio;
778 ndn->dn_oldused = odn->dn_oldused;
779 ndn->dn_oldflags = odn->dn_oldflags;
780 ndn->dn_olduid = odn->dn_olduid;
781 ndn->dn_oldgid = odn->dn_oldgid;
782 ndn->dn_newuid = odn->dn_newuid;
783 ndn->dn_newgid = odn->dn_newgid;
784 ndn->dn_id_flags = odn->dn_id_flags;
785 dmu_zfetch_init(&ndn->dn_zfetch, NULL);
786 list_move_tail(&ndn->dn_zfetch.zf_stream, &odn->dn_zfetch.zf_stream);
787 ndn->dn_zfetch.zf_dnode = odn->dn_zfetch.zf_dnode;
788
789 /*
790 * Update back pointers. Updating the handle fixes the back pointer of
791 * every descendant dbuf as well as the bonus dbuf.
792 */
793 ASSERT(ndn->dn_handle->dnh_dnode == odn);
794 ndn->dn_handle->dnh_dnode = ndn;
795 if (ndn->dn_zfetch.zf_dnode == odn) {
796 ndn->dn_zfetch.zf_dnode = ndn;
797 }
798
799 /*
800 * Invalidate the original dnode by clearing all of its back pointers.
801 */
802 odn->dn_dbuf = NULL;
803 odn->dn_handle = NULL;
804 avl_create(&odn->dn_dbufs, dbuf_compare, sizeof (dmu_buf_impl_t),
805 offsetof(dmu_buf_impl_t, db_link));
806 odn->dn_dbufs_count = 0;
807 odn->dn_bonus = NULL;
808 odn->dn_zfetch.zf_dnode = NULL;
809
810 /*
811 * Set the low bit of the objset pointer to ensure that dnode_move()
812 * recognizes the dnode as invalid in any subsequent callback.
813 */
814 POINTER_INVALIDATE(&odn->dn_objset);
815
816 /*
817 * Satisfy the destructor.
818 */
819 for (i = 0; i < TXG_SIZE; i++) {
820 list_create(&odn->dn_dirty_records[i],
821 sizeof (dbuf_dirty_record_t),
822 offsetof(dbuf_dirty_record_t, dr_dirty_node));
823 odn->dn_free_ranges[i] = NULL;
824 odn->dn_next_nlevels[i] = 0;
825 odn->dn_next_indblkshift[i] = 0;
826 odn->dn_next_bonustype[i] = 0;
827 odn->dn_rm_spillblk[i] = 0;
828 odn->dn_next_bonuslen[i] = 0;
829 odn->dn_next_blksz[i] = 0;
830 }
831 odn->dn_allocated_txg = 0;
832 odn->dn_free_txg = 0;
833 odn->dn_assigned_txg = 0;
834 odn->dn_dirtyctx = 0;
835 odn->dn_dirtyctx_firstset = NULL;
836 odn->dn_have_spill = B_FALSE;
837 odn->dn_zio = NULL;
838 odn->dn_oldused = 0;
839 odn->dn_oldflags = 0;
840 odn->dn_olduid = 0;
841 odn->dn_oldgid = 0;
842 odn->dn_newuid = 0;
843 odn->dn_newgid = 0;
844 odn->dn_id_flags = 0;
845
846 /*
847 * Mark the dnode.
848 */
849 ndn->dn_moved = 1;
850 odn->dn_moved = (uint8_t)-1;
851 }
852
853 /*ARGSUSED*/
854 static kmem_cbrc_t
855 dnode_move(void *buf, void *newbuf, size_t size, void *arg)
856 {
857 dnode_t *odn = buf, *ndn = newbuf;
858 objset_t *os;
859 int64_t refcount;
860 uint32_t dbufs;
861
862 /*
863 * The dnode is on the objset's list of known dnodes if the objset
864 * pointer is valid. We set the low bit of the objset pointer when
865 * freeing the dnode to invalidate it, and the memory patterns written
866 * by kmem (baddcafe and deadbeef) set at least one of the two low bits.
867 * A newly created dnode sets the objset pointer last of all to indicate
868 * that the dnode is known and in a valid state to be moved by this
869 * function.
870 */
871 os = odn->dn_objset;
872 if (!POINTER_IS_VALID(os)) {
873 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_invalid);
874 return (KMEM_CBRC_DONT_KNOW);
875 }
876
877 /*
878 * Ensure that the objset does not go away during the move.
879 */
880 rw_enter(&os_lock, RW_WRITER);
881 if (os != odn->dn_objset) {
882 rw_exit(&os_lock);
883 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_recheck1);
884 return (KMEM_CBRC_DONT_KNOW);
885 }
886
887 /*
888 * If the dnode is still valid, then so is the objset. We know that no
889 * valid objset can be freed while we hold os_lock, so we can safely
890 * ensure that the objset remains in use.
891 */
892 mutex_enter(&os->os_lock);
893
894 /*
895 * Recheck the objset pointer in case the dnode was removed just before
896 * acquiring the lock.
897 */
898 if (os != odn->dn_objset) {
899 mutex_exit(&os->os_lock);
900 rw_exit(&os_lock);
901 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_recheck2);
902 return (KMEM_CBRC_DONT_KNOW);
903 }
904
905 /*
906 * At this point we know that as long as we hold os->os_lock, the dnode
907 * cannot be freed and fields within the dnode can be safely accessed.
908 * The objset listing this dnode cannot go away as long as this dnode is
909 * on its list.
910 */
911 rw_exit(&os_lock);
912 if (DMU_OBJECT_IS_SPECIAL(odn->dn_object)) {
913 mutex_exit(&os->os_lock);
914 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_special);
915 return (KMEM_CBRC_NO);
916 }
917 ASSERT(odn->dn_dbuf != NULL); /* only "special" dnodes have no parent */
918
919 /*
920 * Lock the dnode handle to prevent the dnode from obtaining any new
921 * holds. This also prevents the descendant dbufs and the bonus dbuf
922 * from accessing the dnode, so that we can discount their holds. The
923 * handle is safe to access because we know that while the dnode cannot
924 * go away, neither can its handle. Once we hold dnh_zrlock, we can
925 * safely move any dnode referenced only by dbufs.
926 */
927 if (!zrl_tryenter(&odn->dn_handle->dnh_zrlock)) {
928 mutex_exit(&os->os_lock);
929 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_handle);
930 return (KMEM_CBRC_LATER);
931 }
932
933 /*
934 * Ensure a consistent view of the dnode's holds and the dnode's dbufs.
935 * We need to guarantee that there is a hold for every dbuf in order to
936 * determine whether the dnode is actively referenced. Falsely matching
937 * a dbuf to an active hold would lead to an unsafe move. It's possible
938 * that a thread already having an active dnode hold is about to add a
939 * dbuf, and we can't compare hold and dbuf counts while the add is in
940 * progress.
941 */
942 if (!rw_tryenter(&odn->dn_struct_rwlock, RW_WRITER)) {
943 zrl_exit(&odn->dn_handle->dnh_zrlock);
944 mutex_exit(&os->os_lock);
945 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_rwlock);
946 return (KMEM_CBRC_LATER);
947 }
948
949 /*
950 * A dbuf may be removed (evicted) without an active dnode hold. In that
951 * case, the dbuf count is decremented under the handle lock before the
952 * dbuf's hold is released. This order ensures that if we count the hold
953 * after the dbuf is removed but before its hold is released, we will
954 * treat the unmatched hold as active and exit safely. If we count the
955 * hold before the dbuf is removed, the hold is discounted, and the
956 * removal is blocked until the move completes.
957 */
958 refcount = refcount_count(&odn->dn_holds);
959 ASSERT(refcount >= 0);
960 dbufs = odn->dn_dbufs_count;
961
962 /* We can't have more dbufs than dnode holds. */
963 ASSERT3U(dbufs, <=, refcount);
964 DTRACE_PROBE3(dnode__move, dnode_t *, odn, int64_t, refcount,
965 uint32_t, dbufs);
966
967 if (refcount > dbufs) {
968 rw_exit(&odn->dn_struct_rwlock);
969 zrl_exit(&odn->dn_handle->dnh_zrlock);
970 mutex_exit(&os->os_lock);
971 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_active);
972 return (KMEM_CBRC_LATER);
973 }
974
975 rw_exit(&odn->dn_struct_rwlock);
976
977 /*
978 * At this point we know that anyone with a hold on the dnode is not
979 * actively referencing it. The dnode is known and in a valid state to
980 * move. We're holding the locks needed to execute the critical section.
981 */
982 dnode_move_impl(odn, ndn);
983
984 list_link_replace(&odn->dn_link, &ndn->dn_link);
985 /* If the dnode was safe to move, the refcount cannot have changed. */
986 ASSERT(refcount == refcount_count(&ndn->dn_holds));
987 ASSERT(dbufs == ndn->dn_dbufs_count);
988 zrl_exit(&ndn->dn_handle->dnh_zrlock); /* handle has moved */
989 mutex_exit(&os->os_lock);
990
991 return (KMEM_CBRC_YES);
992 }
993 #endif /* _KERNEL */
994
995 void
996 dnode_special_close(dnode_handle_t *dnh)
997 {
998 dnode_t *dn = dnh->dnh_dnode;
999
1000 /*
1001 * Wait for final references to the dnode to clear. This can
1002 * only happen if the arc is asyncronously evicting state that
1003 * has a hold on this dnode while we are trying to evict this
1004 * dnode.
1005 */
1006 while (refcount_count(&dn->dn_holds) > 0)
1007 delay(1);
1008 ASSERT(dn->dn_dbuf == NULL ||
1009 dmu_buf_get_user(&dn->dn_dbuf->db) == NULL);
1010 zrl_add(&dnh->dnh_zrlock);
1011 dnode_destroy(dn); /* implicit zrl_remove() */
1012 zrl_destroy(&dnh->dnh_zrlock);
1013 dnh->dnh_dnode = NULL;
1014 }
1015
1016 void
1017 dnode_special_open(objset_t *os, dnode_phys_t *dnp, uint64_t object,
1018 dnode_handle_t *dnh)
1019 {
1020 dnode_t *dn;
1021
1022 dn = dnode_create(os, dnp, NULL, object, dnh);
1023 zrl_init(&dnh->dnh_zrlock);
1024 DNODE_VERIFY(dn);
1025 }
1026
1027 static void
1028 dnode_buf_evict_async(void *dbu)
1029 {
1030 dnode_children_t *children_dnodes = dbu;
1031 int i;
1032
1033 for (i = 0; i < children_dnodes->dnc_count; i++) {
1034 dnode_handle_t *dnh = &children_dnodes->dnc_children[i];
1035 dnode_t *dn;
1036
1037 /*
1038 * The dnode handle lock guards against the dnode moving to
1039 * another valid address, so there is no need here to guard
1040 * against changes to or from NULL.
1041 */
1042 if (dnh->dnh_dnode == NULL) {
1043 zrl_destroy(&dnh->dnh_zrlock);
1044 continue;
1045 }
1046
1047 zrl_add(&dnh->dnh_zrlock);
1048 dn = dnh->dnh_dnode;
1049 /*
1050 * If there are holds on this dnode, then there should
1051 * be holds on the dnode's containing dbuf as well; thus
1052 * it wouldn't be eligible for eviction and this function
1053 * would not have been called.
1054 */
1055 ASSERT(refcount_is_zero(&dn->dn_holds));
1056 ASSERT(refcount_is_zero(&dn->dn_tx_holds));
1057
1058 dnode_destroy(dn); /* implicit zrl_remove() */
1059 zrl_destroy(&dnh->dnh_zrlock);
1060 dnh->dnh_dnode = NULL;
1061 }
1062 kmem_free(children_dnodes, sizeof (dnode_children_t) +
1063 children_dnodes->dnc_count * sizeof (dnode_handle_t));
1064 }
1065
1066 /*
1067 * errors:
1068 * EINVAL - invalid object number.
1069 * EIO - i/o error.
1070 * succeeds even for free dnodes.
1071 */
1072 int
1073 dnode_hold_impl(objset_t *os, uint64_t object, int flag,
1074 void *tag, dnode_t **dnp)
1075 {
1076 int epb, idx, err;
1077 int drop_struct_lock = FALSE;
1078 int type;
1079 uint64_t blk;
1080 dnode_t *mdn, *dn;
1081 dmu_buf_impl_t *db;
1082 dnode_children_t *children_dnodes;
1083 dnode_handle_t *dnh;
1084
1085 /*
1086 * If you are holding the spa config lock as writer, you shouldn't
1087 * be asking the DMU to do *anything* unless it's the root pool
1088 * which may require us to read from the root filesystem while
1089 * holding some (not all) of the locks as writer.
1090 */
1091 ASSERT(spa_config_held(os->os_spa, SCL_ALL, RW_WRITER) == 0 ||
1092 (spa_is_root(os->os_spa) &&
1093 spa_config_held(os->os_spa, SCL_STATE, RW_WRITER)));
1094
1095 if (object == DMU_USERUSED_OBJECT || object == DMU_GROUPUSED_OBJECT) {
1096 dn = (object == DMU_USERUSED_OBJECT) ?
1097 DMU_USERUSED_DNODE(os) : DMU_GROUPUSED_DNODE(os);
1098 if (dn == NULL)
1099 return (SET_ERROR(ENOENT));
1100 type = dn->dn_type;
1101 if ((flag & DNODE_MUST_BE_ALLOCATED) && type == DMU_OT_NONE)
1102 return (SET_ERROR(ENOENT));
1103 if ((flag & DNODE_MUST_BE_FREE) && type != DMU_OT_NONE)
1104 return (SET_ERROR(EEXIST));
1105 DNODE_VERIFY(dn);
1106 (void) refcount_add(&dn->dn_holds, tag);
1107 *dnp = dn;
1108 return (0);
1109 }
1110
1111 if (object == 0 || object >= DN_MAX_OBJECT)
1112 return (SET_ERROR(EINVAL));
1113
1114 mdn = DMU_META_DNODE(os);
1115 ASSERT(mdn->dn_object == DMU_META_DNODE_OBJECT);
1116
1117 DNODE_VERIFY(mdn);
1118
1119 if (!RW_WRITE_HELD(&mdn->dn_struct_rwlock)) {
1120 rw_enter(&mdn->dn_struct_rwlock, RW_READER);
1121 drop_struct_lock = TRUE;
1122 }
1123
1124 blk = dbuf_whichblock(mdn, 0, object * sizeof (dnode_phys_t));
1125
1126 db = dbuf_hold(mdn, blk, FTAG);
1127 if (drop_struct_lock)
1128 rw_exit(&mdn->dn_struct_rwlock);
1129 if (db == NULL)
1130 return (SET_ERROR(EIO));
1131 err = dbuf_read(db, NULL, DB_RF_CANFAIL);
1132 if (err) {
1133 dbuf_rele(db, FTAG);
1134 return (err);
1135 }
1136
1137 ASSERT3U(db->db.db_size, >=, 1<<DNODE_SHIFT);
1138 epb = db->db.db_size >> DNODE_SHIFT;
1139
1140 idx = object & (epb-1);
1141
1142 ASSERT(DB_DNODE(db)->dn_type == DMU_OT_DNODE);
1143 children_dnodes = dmu_buf_get_user(&db->db);
1144 if (children_dnodes == NULL) {
1145 int i;
1146 dnode_children_t *winner;
1147 children_dnodes = kmem_zalloc(sizeof (dnode_children_t) +
1148 epb * sizeof (dnode_handle_t), KM_SLEEP);
1149 children_dnodes->dnc_count = epb;
1150 dnh = &children_dnodes->dnc_children[0];
1151 for (i = 0; i < epb; i++) {
1152 zrl_init(&dnh[i].dnh_zrlock);
1153 }
1154 dmu_buf_init_user(&children_dnodes->dnc_dbu, NULL,
1155 dnode_buf_evict_async, NULL);
1156 winner = dmu_buf_set_user(&db->db, &children_dnodes->dnc_dbu);
1157 if (winner != NULL) {
1158
1159 for (i = 0; i < epb; i++) {
1160 zrl_destroy(&dnh[i].dnh_zrlock);
1161 }
1162
1163 kmem_free(children_dnodes, sizeof (dnode_children_t) +
1164 epb * sizeof (dnode_handle_t));
1165 children_dnodes = winner;
1166 }
1167 }
1168 ASSERT(children_dnodes->dnc_count == epb);
1169
1170 dnh = &children_dnodes->dnc_children[idx];
1171 zrl_add(&dnh->dnh_zrlock);
1172 dn = dnh->dnh_dnode;
1173 if (dn == NULL) {
1174 dnode_phys_t *phys = (dnode_phys_t *)db->db.db_data+idx;
1175
1176 dn = dnode_create(os, phys, db, object, dnh);
1177 }
1178
1179 mutex_enter(&dn->dn_mtx);
1180 type = dn->dn_type;
1181 if (dn->dn_free_txg ||
1182 ((flag & DNODE_MUST_BE_ALLOCATED) && type == DMU_OT_NONE) ||
1183 ((flag & DNODE_MUST_BE_FREE) &&
1184 (type != DMU_OT_NONE || !refcount_is_zero(&dn->dn_holds)))) {
1185 mutex_exit(&dn->dn_mtx);
1186 zrl_remove(&dnh->dnh_zrlock);
1187 dbuf_rele(db, FTAG);
1188 return (type == DMU_OT_NONE ? ENOENT : EEXIST);
1189 }
1190 if (refcount_add(&dn->dn_holds, tag) == 1)
1191 dbuf_add_ref(db, dnh);
1192 mutex_exit(&dn->dn_mtx);
1193
1194 /* Now we can rely on the hold to prevent the dnode from moving. */
1195 zrl_remove(&dnh->dnh_zrlock);
1196
1197 DNODE_VERIFY(dn);
1198 ASSERT3P(dn->dn_dbuf, ==, db);
1199 ASSERT3U(dn->dn_object, ==, object);
1200 dbuf_rele(db, FTAG);
1201
1202 *dnp = dn;
1203 return (0);
1204 }
1205
1206 /*
1207 * Return held dnode if the object is allocated, NULL if not.
1208 */
1209 int
1210 dnode_hold(objset_t *os, uint64_t object, void *tag, dnode_t **dnp)
1211 {
1212 return (dnode_hold_impl(os, object, DNODE_MUST_BE_ALLOCATED, tag, dnp));
1213 }
1214
1215 /*
1216 * Can only add a reference if there is already at least one
1217 * reference on the dnode. Returns FALSE if unable to add a
1218 * new reference.
1219 */
1220 boolean_t
1221 dnode_add_ref(dnode_t *dn, void *tag)
1222 {
1223 mutex_enter(&dn->dn_mtx);
1224 if (refcount_is_zero(&dn->dn_holds)) {
1225 mutex_exit(&dn->dn_mtx);
1226 return (FALSE);
1227 }
1228 VERIFY(1 < refcount_add(&dn->dn_holds, tag));
1229 mutex_exit(&dn->dn_mtx);
1230 return (TRUE);
1231 }
1232
1233 void
1234 dnode_rele(dnode_t *dn, void *tag)
1235 {
1236 mutex_enter(&dn->dn_mtx);
1237 dnode_rele_and_unlock(dn, tag);
1238 }
1239
1240 void
1241 dnode_rele_and_unlock(dnode_t *dn, void *tag)
1242 {
1243 uint64_t refs;
1244 /* Get while the hold prevents the dnode from moving. */
1245 dmu_buf_impl_t *db = dn->dn_dbuf;
1246 dnode_handle_t *dnh = dn->dn_handle;
1247
1248 refs = refcount_remove(&dn->dn_holds, tag);
1249 mutex_exit(&dn->dn_mtx);
1250
1251 /*
1252 * It's unsafe to release the last hold on a dnode by dnode_rele() or
1253 * indirectly by dbuf_rele() while relying on the dnode handle to
1254 * prevent the dnode from moving, since releasing the last hold could
1255 * result in the dnode's parent dbuf evicting its dnode handles. For
1256 * that reason anyone calling dnode_rele() or dbuf_rele() without some
1257 * other direct or indirect hold on the dnode must first drop the dnode
1258 * handle.
1259 */
1260 ASSERT(refs > 0 || dnh->dnh_zrlock.zr_owner != curthread);
1261
1262 /* NOTE: the DNODE_DNODE does not have a dn_dbuf */
1263 if (refs == 0 && db != NULL) {
1264 /*
1265 * Another thread could add a hold to the dnode handle in
1266 * dnode_hold_impl() while holding the parent dbuf. Since the
1267 * hold on the parent dbuf prevents the handle from being
1268 * destroyed, the hold on the handle is OK. We can't yet assert
1269 * that the handle has zero references, but that will be
1270 * asserted anyway when the handle gets destroyed.
1271 */
1272 dbuf_rele(db, dnh);
1273 }
1274 }
1275
1276 void
1277 dnode_setdirty(dnode_t *dn, dmu_tx_t *tx)
1278 {
1279 dnode_setdirty_sc(dn, tx, B_TRUE);
1280 }
1281
1282 void
1283 dnode_setdirty_sc(dnode_t *dn, dmu_tx_t *tx, boolean_t usesc)
1284 {
1285 objset_t *os = dn->dn_objset;
1286 uint64_t txg = tx->tx_txg;
1287
1288 if (DMU_OBJECT_IS_SPECIAL(dn->dn_object)) {
1289 dsl_dataset_dirty(os->os_dsl_dataset, tx);
1290 return;
1291 }
1292
1293 DNODE_VERIFY(dn);
1294
1295 #ifdef ZFS_DEBUG
1296 mutex_enter(&dn->dn_mtx);
1297 ASSERT(dn->dn_phys->dn_type || dn->dn_allocated_txg);
1298 ASSERT(dn->dn_free_txg == 0 || dn->dn_free_txg >= txg);
1299 mutex_exit(&dn->dn_mtx);
1300 #endif
1301
1302 /*
1303 * Determine old uid/gid when necessary
1304 */
1305 dmu_objset_userquota_get_ids(dn, B_TRUE, tx);
1306
1307 multilist_t *dirtylist = os->os_dirty_dnodes[txg & TXG_MASK];
1308 multilist_sublist_t *mls = multilist_sublist_lock_obj(dirtylist, dn);
1309
1310 /*
1311 * If we are already marked dirty, we're done.
1312 */
1313 if (list_link_active(&dn->dn_dirty_link[txg & TXG_MASK])) {
1314 multilist_sublist_unlock(mls);
1315 return;
1316 }
1317
1318 ASSERT(!refcount_is_zero(&dn->dn_holds) ||
1319 !avl_is_empty(&dn->dn_dbufs));
1320 ASSERT(dn->dn_datablksz != 0);
1321 ASSERT0(dn->dn_next_bonuslen[txg&TXG_MASK]);
1322 ASSERT0(dn->dn_next_blksz[txg&TXG_MASK]);
1323 ASSERT0(dn->dn_next_bonustype[txg&TXG_MASK]);
1324
1325 dprintf_ds(os->os_dsl_dataset, "obj=%llu txg=%llu\n",
1326 dn->dn_object, txg);
1327
1328 multilist_sublist_insert_head(mls, dn);
1329
1330 multilist_sublist_unlock(mls);
1331
1332 /*
1333 * The dnode maintains a hold on its containing dbuf as
1334 * long as there are holds on it. Each instantiated child
1335 * dbuf maintains a hold on the dnode. When the last child
1336 * drops its hold, the dnode will drop its hold on the
1337 * containing dbuf. We add a "dirty hold" here so that the
1338 * dnode will hang around after we finish processing its
1339 * children.
1340 */
1341 VERIFY(dnode_add_ref(dn, (void *)(uintptr_t)tx->tx_txg));
1342
1343 (void) dbuf_dirty_sc(dn->dn_dbuf, tx, usesc);
1344 dsl_dataset_dirty(os->os_dsl_dataset, tx);
1345 }
1346
1347 void
1348 dnode_free(dnode_t *dn, dmu_tx_t *tx)
1349 {
1350 mutex_enter(&dn->dn_mtx);
1351 if (dn->dn_type == DMU_OT_NONE || dn->dn_free_txg) {
1352 mutex_exit(&dn->dn_mtx);
1353 return;
1354 }
1355 dn->dn_free_txg = tx->tx_txg;
1356 mutex_exit(&dn->dn_mtx);
1357
1358 dnode_setdirty(dn, tx);
1359 }
1360
1361 /*
1362 * Try to change the block size for the indicated dnode. This can only
1363 * succeed if there are no blocks allocated or dirty beyond first block
1364 */
1365 int
1366 dnode_set_blksz(dnode_t *dn, uint64_t size, int ibs, dmu_tx_t *tx)
1367 {
1368 dmu_buf_impl_t *db;
1369 int err;
1370
1371 ASSERT3U(size, <=, spa_maxblocksize(dmu_objset_spa(dn->dn_objset)));
1372 if (size == 0)
1373 size = SPA_MINBLOCKSIZE;
1374 else
1375 size = P2ROUNDUP(size, SPA_MINBLOCKSIZE);
1376
1377 if (ibs == dn->dn_indblkshift)
1378 ibs = 0;
1379
1380 if (size >> SPA_MINBLOCKSHIFT == dn->dn_datablkszsec && ibs == 0)
1381 return (0);
1382
1383 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
1384
1385 /* Check for any allocated blocks beyond the first */
1386 if (dn->dn_maxblkid != 0)
1387 goto fail;
1388
1389 mutex_enter(&dn->dn_dbufs_mtx);
1390 for (db = avl_first(&dn->dn_dbufs); db != NULL;
1391 db = AVL_NEXT(&dn->dn_dbufs, db)) {
1392 if (db->db_blkid != 0 && db->db_blkid != DMU_BONUS_BLKID &&
1393 db->db_blkid != DMU_SPILL_BLKID) {
1394 mutex_exit(&dn->dn_dbufs_mtx);
1395 goto fail;
1396 }
1397 }
1398 mutex_exit(&dn->dn_dbufs_mtx);
1399
1400 if (ibs && dn->dn_nlevels != 1)
1401 goto fail;
1402
1403 /* resize the old block */
1404 err = dbuf_hold_impl(dn, 0, 0, TRUE, FALSE, FTAG, &db);
1405 if (err == 0)
1406 dbuf_new_size(db, size, tx);
1407 else if (err != ENOENT)
1408 goto fail;
1409
1410 dnode_setdblksz(dn, size);
1411 dnode_setdirty(dn, tx);
1412 dn->dn_next_blksz[tx->tx_txg&TXG_MASK] = size;
1413 if (ibs) {
1414 dn->dn_indblkshift = ibs;
1415 dn->dn_next_indblkshift[tx->tx_txg&TXG_MASK] = ibs;
1416 }
1417 /* rele after we have fixed the blocksize in the dnode */
1418 if (db)
1419 dbuf_rele(db, FTAG);
1420
1421 rw_exit(&dn->dn_struct_rwlock);
1422 return (0);
1423
1424 fail:
1425 rw_exit(&dn->dn_struct_rwlock);
1426 return (SET_ERROR(ENOTSUP));
1427 }
1428
1429 /* read-holding callers must not rely on the lock being continuously held */
1430 void
1431 dnode_new_blkid(dnode_t *dn, uint64_t blkid, dmu_tx_t *tx,
1432 boolean_t usesc, boolean_t have_read)
1433 {
1434 uint64_t txgoff = tx->tx_txg & TXG_MASK;
1435 int epbs, new_nlevels;
1436 uint64_t sz;
1437
1438 ASSERT(blkid != DMU_BONUS_BLKID);
1439
1440 ASSERT(have_read ?
1441 RW_READ_HELD(&dn->dn_struct_rwlock) :
1442 RW_WRITE_HELD(&dn->dn_struct_rwlock));
1443
1444 /*
1445 * if we have a read-lock, check to see if we need to do any work
1446 * before upgrading to a write-lock.
1447 */
1448 if (have_read) {
1449 if (blkid <= dn->dn_maxblkid)
1450 return;
1451
1452 if (!rw_tryupgrade(&dn->dn_struct_rwlock)) {
1453 rw_exit(&dn->dn_struct_rwlock);
1454 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
1455 }
1456 }
1457
1458 if (blkid <= dn->dn_maxblkid)
1459 goto out;
1460
1461 dn->dn_maxblkid = blkid;
1462
1463 /*
1464 * Compute the number of levels necessary to support the new maxblkid.
1465 */
1466 new_nlevels = 1;
1467 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT;
1468 for (sz = dn->dn_nblkptr;
1469 sz <= blkid && sz >= dn->dn_nblkptr; sz <<= epbs)
1470 new_nlevels++;
1471
1472 if (new_nlevels > dn->dn_nlevels) {
1473 int old_nlevels = dn->dn_nlevels;
1474 dmu_buf_impl_t *db;
1475 list_t *list;
1476 dbuf_dirty_record_t *new, *dr, *dr_next;
1477
1478 dn->dn_nlevels = new_nlevels;
1479
1480 ASSERT3U(new_nlevels, >, dn->dn_next_nlevels[txgoff]);
1481 dn->dn_next_nlevels[txgoff] = new_nlevels;
1482
1483 /* dirty the left indirects */
1484 db = dbuf_hold_level(dn, old_nlevels, 0, FTAG);
1485 ASSERT(db != NULL);
1486 new = dbuf_dirty_sc(db, tx, usesc);
1487 dbuf_rele(db, FTAG);
1488
1489 /* transfer the dirty records to the new indirect */
1490 mutex_enter(&dn->dn_mtx);
1491 mutex_enter(&new->dt.di.dr_mtx);
1492 list = &dn->dn_dirty_records[txgoff];
1493 for (dr = list_head(list); dr; dr = dr_next) {
1494 dr_next = list_next(&dn->dn_dirty_records[txgoff], dr);
1495 if (dr->dr_dbuf->db_level != new_nlevels-1 &&
1496 dr->dr_dbuf->db_blkid != DMU_BONUS_BLKID &&
1497 dr->dr_dbuf->db_blkid != DMU_SPILL_BLKID) {
1498 ASSERT(dr->dr_dbuf->db_level == old_nlevels-1);
1499 list_remove(&dn->dn_dirty_records[txgoff], dr);
1500 list_insert_tail(&new->dt.di.dr_children, dr);
1501 dr->dr_parent = new;
1502 }
1503 }
1504 mutex_exit(&new->dt.di.dr_mtx);
1505 mutex_exit(&dn->dn_mtx);
1506 }
1507
1508 out:
1509 if (have_read)
1510 rw_downgrade(&dn->dn_struct_rwlock);
1511 }
1512
1513 static void
1514 dnode_dirty_l1(dnode_t *dn, uint64_t l1blkid, dmu_tx_t *tx)
1515 {
1516 dmu_buf_impl_t *db = dbuf_hold_level(dn, 1, l1blkid, FTAG);
1517 if (db != NULL) {
1518 dmu_buf_will_dirty(&db->db, tx);
1519 dbuf_rele(db, FTAG);
1520 }
1521 }
1522
1523 void
1524 dnode_free_range(dnode_t *dn, uint64_t off, uint64_t len, dmu_tx_t *tx)
1525 {
1526 dmu_buf_impl_t *db;
1527 uint64_t blkoff, blkid, nblks;
1528 int blksz, blkshift, head, tail;
1529 int trunc = FALSE;
1530 int epbs;
1531
1532 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
1533 blksz = dn->dn_datablksz;
1534 blkshift = dn->dn_datablkshift;
1535 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT;
1536
1537 if (len == DMU_OBJECT_END) {
1538 len = UINT64_MAX - off;
1539 trunc = TRUE;
1540 }
1541
1542 /*
1543 * First, block align the region to free:
1544 */
1545 if (ISP2(blksz)) {
1546 head = P2NPHASE(off, blksz);
1547 blkoff = P2PHASE(off, blksz);
1548 if ((off >> blkshift) > dn->dn_maxblkid)
1549 goto out;
1550 } else {
1551 ASSERT(dn->dn_maxblkid == 0);
1552 if (off == 0 && len >= blksz) {
1553 /*
1554 * Freeing the whole block; fast-track this request.
1555 * Note that we won't dirty any indirect blocks,
1556 * which is fine because we will be freeing the entire
1557 * file and thus all indirect blocks will be freed
1558 * by free_children().
1559 */
1560 blkid = 0;
1561 nblks = 1;
1562 goto done;
1563 } else if (off >= blksz) {
1564 /* Freeing past end-of-data */
1565 goto out;
1566 } else {
1567 /* Freeing part of the block. */
1568 head = blksz - off;
1569 ASSERT3U(head, >, 0);
1570 }
1571 blkoff = off;
1572 }
1573 /* zero out any partial block data at the start of the range */
1574 if (head) {
1575 ASSERT3U(blkoff + head, ==, blksz);
1576 if (len < head)
1577 head = len;
1578 if (dbuf_hold_impl(dn, 0, dbuf_whichblock(dn, 0, off),
1579 TRUE, FALSE, FTAG, &db) == 0) {
1580 caddr_t data;
1581
1582 /* don't dirty if it isn't on disk and isn't dirty */
1583 if (db->db_last_dirty ||
1584 (db->db_blkptr && !BP_IS_HOLE(db->db_blkptr))) {
1585 rw_exit(&dn->dn_struct_rwlock);
1586 dmu_buf_will_dirty(&db->db, tx);
1587 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
1588 data = db->db.db_data;
1589 bzero(data + blkoff, head);
1590 }
1591 dbuf_rele(db, FTAG);
1592 }
1593 off += head;
1594 len -= head;
1595 }
1596
1597 /* If the range was less than one block, we're done */
1598 if (len == 0)
1599 goto out;
1600
1601 /* If the remaining range is past end of file, we're done */
1602 if ((off >> blkshift) > dn->dn_maxblkid)
1603 goto out;
1604
1605 ASSERT(ISP2(blksz));
1606 if (trunc)
1607 tail = 0;
1608 else
1609 tail = P2PHASE(len, blksz);
1610
1611 ASSERT0(P2PHASE(off, blksz));
1612 /* zero out any partial block data at the end of the range */
1613 if (tail) {
1614 if (len < tail)
1615 tail = len;
1616 if (dbuf_hold_impl(dn, 0, dbuf_whichblock(dn, 0, off+len),
1617 TRUE, FALSE, FTAG, &db) == 0) {
1618 /* don't dirty if not on disk and not dirty */
1619 if (db->db_last_dirty ||
1620 (db->db_blkptr && !BP_IS_HOLE(db->db_blkptr))) {
1621 rw_exit(&dn->dn_struct_rwlock);
1622 dmu_buf_will_dirty(&db->db, tx);
1623 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
1624 bzero(db->db.db_data, tail);
1625 }
1626 dbuf_rele(db, FTAG);
1627 }
1628 len -= tail;
1629 }
1630
1631 /* If the range did not include a full block, we are done */
1632 if (len == 0)
1633 goto out;
1634
1635 ASSERT(IS_P2ALIGNED(off, blksz));
1636 ASSERT(trunc || IS_P2ALIGNED(len, blksz));
1637 blkid = off >> blkshift;
1638 nblks = len >> blkshift;
1639 if (trunc)
1640 nblks += 1;
1641
1642 /*
1643 * Dirty all the indirect blocks in this range. Note that only
1644 * the first and last indirect blocks can actually be written
1645 * (if they were partially freed) -- they must be dirtied, even if
1646 * they do not exist on disk yet. The interior blocks will
1647 * be freed by free_children(), so they will not actually be written.
1648 * Even though these interior blocks will not be written, we
1649 * dirty them for two reasons:
1650 *
1651 * - It ensures that the indirect blocks remain in memory until
1652 * syncing context. (They have already been prefetched by
1653 * dmu_tx_hold_free(), so we don't have to worry about reading
1654 * them serially here.)
1655 *
1656 * - The dirty space accounting will put pressure on the txg sync
1657 * mechanism to begin syncing, and to delay transactions if there
1658 * is a large amount of freeing. Even though these indirect
1659 * blocks will not be written, we could need to write the same
1660 * amount of space if we copy the freed BPs into deadlists.
1661 */
1662 if (dn->dn_nlevels > 1) {
1663 uint64_t first, last;
1664
1665 first = blkid >> epbs;
1666 dnode_dirty_l1(dn, first, tx);
1667 if (trunc)
1668 last = dn->dn_maxblkid >> epbs;
1669 else
1670 last = (blkid + nblks - 1) >> epbs;
1671 if (last != first)
1672 dnode_dirty_l1(dn, last, tx);
1673
1674 int shift = dn->dn_datablkshift + dn->dn_indblkshift -
1675 SPA_BLKPTRSHIFT;
1676 for (uint64_t i = first + 1; i < last; i++) {
1677 /*
1678 * Set i to the blockid of the next non-hole
1679 * level-1 indirect block at or after i. Note
1680 * that dnode_next_offset() operates in terms of
1681 * level-0-equivalent bytes.
1682 */
1683 uint64_t ibyte = i << shift;
1684 int err = dnode_next_offset(dn, DNODE_FIND_HAVELOCK,
1685 &ibyte, 2, 1, 0);
1686 i = ibyte >> shift;
1687 if (i >= last)
1688 break;
1689
1690 /*
1691 * Normally we should not see an error, either
1692 * from dnode_next_offset() or dbuf_hold_level()
1693 * (except for ESRCH from dnode_next_offset).
1694 * If there is an i/o error, then when we read
1695 * this block in syncing context, it will use
1696 * ZIO_FLAG_MUSTSUCCEED, and thus hang/panic according
1697 * to the "failmode" property. dnode_next_offset()
1698 * doesn't have a flag to indicate MUSTSUCCEED.
1699 */
1700 if (err != 0)
1701 break;
1702
1703 dnode_dirty_l1(dn, i, tx);
1704 }
1705 }
1706
1707 done:
1708 /*
1709 * Add this range to the dnode range list.
1710 * We will finish up this free operation in the syncing phase.
1711 */
1712 mutex_enter(&dn->dn_mtx);
1713 int txgoff = tx->tx_txg & TXG_MASK;
1714 if (dn->dn_free_ranges[txgoff] == NULL) {
1715 dn->dn_free_ranges[txgoff] =
1716 range_tree_create(NULL, NULL, &dn->dn_mtx);
1717 }
1718 range_tree_clear(dn->dn_free_ranges[txgoff], blkid, nblks);
1719 range_tree_add(dn->dn_free_ranges[txgoff], blkid, nblks);
1720 dprintf_dnode(dn, "blkid=%llu nblks=%llu txg=%llu\n",
1721 blkid, nblks, tx->tx_txg);
1722 mutex_exit(&dn->dn_mtx);
1723
1724 dbuf_free_range(dn, blkid, blkid + nblks - 1, tx);
1725 dnode_setdirty(dn, tx);
1726 out:
1727
1728 rw_exit(&dn->dn_struct_rwlock);
1729 }
1730
1731 static boolean_t
1732 dnode_spill_freed(dnode_t *dn)
1733 {
1734 int i;
1735
1736 mutex_enter(&dn->dn_mtx);
1737 for (i = 0; i < TXG_SIZE; i++) {
1738 if (dn->dn_rm_spillblk[i] == DN_KILL_SPILLBLK)
1739 break;
1740 }
1741 mutex_exit(&dn->dn_mtx);
1742 return (i < TXG_SIZE);
1743 }
1744
1745 /* return TRUE if this blkid was freed in a recent txg, or FALSE if it wasn't */
1746 uint64_t
1747 dnode_block_freed(dnode_t *dn, uint64_t blkid)
1748 {
1749 void *dp = spa_get_dsl(dn->dn_objset->os_spa);
1750 int i;
1751
1752 if (blkid == DMU_BONUS_BLKID)
1753 return (FALSE);
1754
1755 /*
1756 * If we're in the process of opening the pool, dp will not be
1757 * set yet, but there shouldn't be anything dirty.
1758 */
1759 if (dp == NULL)
1760 return (FALSE);
1761
1762 if (dn->dn_free_txg)
1763 return (TRUE);
1764
1765 if (blkid == DMU_SPILL_BLKID)
1766 return (dnode_spill_freed(dn));
1767
1768 mutex_enter(&dn->dn_mtx);
1769 for (i = 0; i < TXG_SIZE; i++) {
1770 if (dn->dn_free_ranges[i] != NULL &&
1771 range_tree_contains(dn->dn_free_ranges[i], blkid, 1))
1772 break;
1773 }
1774 mutex_exit(&dn->dn_mtx);
1775 return (i < TXG_SIZE);
1776 }
1777
1778 /* call from syncing context when we actually write/free space for this dnode */
1779 void
1780 dnode_diduse_space(dnode_t *dn, int64_t delta)
1781 {
1782 uint64_t space;
1783 dprintf_dnode(dn, "dn=%p dnp=%p used=%llu delta=%lld\n",
1784 dn, dn->dn_phys,
1785 (u_longlong_t)dn->dn_phys->dn_used,
1786 (longlong_t)delta);
1787
1788 mutex_enter(&dn->dn_mtx);
1789 space = DN_USED_BYTES(dn->dn_phys);
1790 if (delta > 0) {
1791 ASSERT3U(space + delta, >=, space); /* no overflow */
1792 } else {
1793 ASSERT3U(space, >=, -delta); /* no underflow */
1794 }
1795 space += delta;
1796 if (spa_version(dn->dn_objset->os_spa) < SPA_VERSION_DNODE_BYTES) {
1797 ASSERT((dn->dn_phys->dn_flags & DNODE_FLAG_USED_BYTES) == 0);
1798 ASSERT0(P2PHASE(space, 1<<DEV_BSHIFT));
1799 dn->dn_phys->dn_used = space >> DEV_BSHIFT;
1800 } else {
1801 dn->dn_phys->dn_used = space;
1802 dn->dn_phys->dn_flags |= DNODE_FLAG_USED_BYTES;
1803 }
1804 mutex_exit(&dn->dn_mtx);
1805 }
1806
1807 /*
1808 * Scans a block at the indicated "level" looking for a hole or data,
1809 * depending on 'flags'.
1810 *
1811 * If level > 0, then we are scanning an indirect block looking at its
1812 * pointers. If level == 0, then we are looking at a block of dnodes.
1813 *
1814 * If we don't find what we are looking for in the block, we return ESRCH.
1815 * Otherwise, return with *offset pointing to the beginning (if searching
1816 * forwards) or end (if searching backwards) of the range covered by the
1817 * block pointer we matched on (or dnode).
1818 *
1819 * The basic search algorithm used below by dnode_next_offset() is to
1820 * use this function to search up the block tree (widen the search) until
1821 * we find something (i.e., we don't return ESRCH) and then search back
1822 * down the tree (narrow the search) until we reach our original search
1823 * level.
1824 */
1825 static int
1826 dnode_next_offset_level(dnode_t *dn, int flags, uint64_t *offset,
1827 int lvl, uint64_t blkfill, uint64_t txg)
1828 {
1829 dmu_buf_impl_t *db = NULL;
1830 void *data = NULL;
1831 uint64_t epbs = dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT;
1832 uint64_t epb = 1ULL << epbs;
1833 uint64_t minfill, maxfill;
1834 boolean_t hole;
1835 int i, inc, error, span;
1836
1837 dprintf("probing object %llu offset %llx level %d of %u\n",
1838 dn->dn_object, *offset, lvl, dn->dn_phys->dn_nlevels);
1839
1840 hole = ((flags & DNODE_FIND_HOLE) != 0);
1841 inc = (flags & DNODE_FIND_BACKWARDS) ? -1 : 1;
1842 ASSERT(txg == 0 || !hole);
1843
1844 if (lvl == dn->dn_phys->dn_nlevels) {
1845 error = 0;
1846 epb = dn->dn_phys->dn_nblkptr;
1847 data = dn->dn_phys->dn_blkptr;
1848 } else {
1849 uint64_t blkid = dbuf_whichblock(dn, lvl, *offset);
1850 error = dbuf_hold_impl(dn, lvl, blkid, TRUE, FALSE, FTAG, &db);
1851 if (error) {
1852 if (error != ENOENT)
1853 return (error);
1854 if (hole)
1855 return (0);
1856 /*
1857 * This can only happen when we are searching up
1858 * the block tree for data. We don't really need to
1859 * adjust the offset, as we will just end up looking
1860 * at the pointer to this block in its parent, and its
1861 * going to be unallocated, so we will skip over it.
1862 */
1863 return (SET_ERROR(ESRCH));
1864 }
1865 error = dbuf_read(db, NULL, DB_RF_CANFAIL | DB_RF_HAVESTRUCT);
1866 if (error) {
1867 dbuf_rele(db, FTAG);
1868 return (error);
1869 }
1870 data = db->db.db_data;
1871 }
1872
1873
1874 if (db != NULL && txg != 0 && (db->db_blkptr == NULL ||
1875 db->db_blkptr->blk_birth <= txg ||
1876 BP_IS_HOLE(db->db_blkptr))) {
1877 /*
1878 * This can only happen when we are searching up the tree
1879 * and these conditions mean that we need to keep climbing.
1880 */
1881 error = SET_ERROR(ESRCH);
1882 } else if (lvl == 0) {
1883 dnode_phys_t *dnp = data;
1884 span = DNODE_SHIFT;
1885 ASSERT(dn->dn_type == DMU_OT_DNODE);
1886
1887 for (i = (*offset >> span) & (blkfill - 1);
1888 i >= 0 && i < blkfill; i += inc) {
1889 if ((dnp[i].dn_type == DMU_OT_NONE) == hole)
1890 break;
1891 *offset += (1ULL << span) * inc;
1892 }
1893 if (i < 0 || i == blkfill)
1894 error = SET_ERROR(ESRCH);
1895 } else {
1896 blkptr_t *bp = data;
1897 uint64_t start = *offset;
1898 span = (lvl - 1) * epbs + dn->dn_datablkshift;
1899 minfill = 0;
1900 maxfill = blkfill << ((lvl - 1) * epbs);
1901
1902 if (hole)
1903 maxfill--;
1904 else
1905 minfill++;
1906
1907 *offset = *offset >> span;
1908 for (i = BF64_GET(*offset, 0, epbs);
1909 i >= 0 && i < epb; i += inc) {
1910 if (BP_GET_FILL(&bp[i]) >= minfill &&
1911 BP_GET_FILL(&bp[i]) <= maxfill &&
1912 (hole || bp[i].blk_birth > txg))
1913 break;
1914 if (inc > 0 || *offset > 0)
1915 *offset += inc;
1916 }
1917 *offset = *offset << span;
1918 if (inc < 0) {
1919 /* traversing backwards; position offset at the end */
1920 ASSERT3U(*offset, <=, start);
1921 *offset = MIN(*offset + (1ULL << span) - 1, start);
1922 } else if (*offset < start) {
1923 *offset = start;
1924 }
1925 if (i < 0 || i >= epb)
1926 error = SET_ERROR(ESRCH);
1927 }
1928
1929 if (db)
1930 dbuf_rele(db, FTAG);
1931
1932 return (error);
1933 }
1934
1935 /*
1936 * Find the next hole, data, or sparse region at or after *offset.
1937 * The value 'blkfill' tells us how many items we expect to find
1938 * in an L0 data block; this value is 1 for normal objects,
1939 * DNODES_PER_BLOCK for the meta dnode, and some fraction of
1940 * DNODES_PER_BLOCK when searching for sparse regions thereof.
1941 *
1942 * Examples:
1943 *
1944 * dnode_next_offset(dn, flags, offset, 1, 1, 0);
1945 * Finds the next/previous hole/data in a file.
1946 * Used in dmu_offset_next().
1947 *
1948 * dnode_next_offset(mdn, flags, offset, 0, DNODES_PER_BLOCK, txg);
1949 * Finds the next free/allocated dnode an objset's meta-dnode.
1950 * Only finds objects that have new contents since txg (ie.
1951 * bonus buffer changes and content removal are ignored).
1952 * Used in dmu_object_next().
1953 *
1954 * dnode_next_offset(mdn, DNODE_FIND_HOLE, offset, 2, DNODES_PER_BLOCK >> 2, 0);
1955 * Finds the next L2 meta-dnode bp that's at most 1/4 full.
1956 * Used in dmu_object_alloc().
1957 */
1958 int
1959 dnode_next_offset(dnode_t *dn, int flags, uint64_t *offset,
1960 int minlvl, uint64_t blkfill, uint64_t txg)
1961 {
1962 uint64_t initial_offset = *offset;
1963 int lvl, maxlvl;
1964 int error = 0;
1965
1966 if (!(flags & DNODE_FIND_HAVELOCK))
1967 rw_enter(&dn->dn_struct_rwlock, RW_READER);
1968
1969 if (dn->dn_phys->dn_nlevels == 0) {
1970 error = SET_ERROR(ESRCH);
1971 goto out;
1972 }
1973
1974 if (dn->dn_datablkshift == 0) {
1975 if (*offset < dn->dn_datablksz) {
1976 if (flags & DNODE_FIND_HOLE)
1977 *offset = dn->dn_datablksz;
1978 } else {
1979 error = SET_ERROR(ESRCH);
1980 }
1981 goto out;
1982 }
1983
1984 maxlvl = dn->dn_phys->dn_nlevels;
1985
1986 for (lvl = minlvl; lvl <= maxlvl; lvl++) {
1987 error = dnode_next_offset_level(dn,
1988 flags, offset, lvl, blkfill, txg);
1989 if (error != ESRCH)
1990 break;
1991 }
1992
1993 while (error == 0 && --lvl >= minlvl) {
1994 error = dnode_next_offset_level(dn,
1995 flags, offset, lvl, blkfill, txg);
1996 }
1997
1998 /*
1999 * There's always a "virtual hole" at the end of the object, even
2000 * if all BP's which physically exist are non-holes.
2001 */
2002 if ((flags & DNODE_FIND_HOLE) && error == ESRCH && txg == 0 &&
2003 minlvl == 1 && blkfill == 1 && !(flags & DNODE_FIND_BACKWARDS)) {
2004 error = 0;
2005 }
2006
2007 if (error == 0 && (flags & DNODE_FIND_BACKWARDS ?
2008 initial_offset < *offset : initial_offset > *offset))
2009 error = SET_ERROR(ESRCH);
2010 out:
2011 if (!(flags & DNODE_FIND_HAVELOCK))
2012 rw_exit(&dn->dn_struct_rwlock);
2013
2014 return (error);
2015 }
2016
2017 /*
2018 * When in the compressing phase, we check our results every 1 MiB. If
2019 * compression ratio drops below the threshold factor, we give up trying
2020 * to compress the file for a while. The length of the interval is
2021 * calculated from this interval value according to the algorithm in
2022 * smartcomp_check_comp.
2023 */
2024 uint64_t zfs_smartcomp_interval = 1 * 1024 * 1024;
2025
2026 /*
2027 * Minimum compression factor is 12.5% (100% / factor) - below that we
2028 * consider compression to have failed.
2029 */
2030 uint64_t zfs_smartcomp_threshold_factor = 8;
2031
2032 /*
2033 * Maximum power-of-2 exponent on the deny interval and consequently
2034 * the maximum number of compression successes and failures we track.
2035 * Successive compression failures extend the deny interval, whereas
2036 * repeated successes makes the algorithm more hesitant to start denying.
2037 */
2038 int64_t zfs_smartcomp_interval_exp = 5;
2039
2040 /*
2041 * Callback invoked by the zio machinery when it wants to compress a data
2042 * block. If we are in the denying compression phase, we add the amount of
2043 * data written to our stats and check if we've denied enough data to
2044 * transition back in to the compression phase again.
2045 */
2046 boolean_t
2047 dnode_smartcomp_ask_cb(void *userinfo, const zio_t *zio)
2048 {
2049 dnode_t *dn = userinfo;
2050 dnode_smartcomp_t *sc;
2051 dnode_smartcomp_state_t old_state;
2052
2053 ASSERT(dn != NULL);
2054
2055 sc = &dn->dn_smartcomp;
2056 mutex_enter(&sc->sc_lock);
2057 old_state = sc->sc_state;
2058 if (sc->sc_state == DNODE_SMARTCOMP_DENYING) {
2059 sc->sc_orig_size += zio->io_orig_size;
2060 if (sc->sc_orig_size >= sc->sc_deny_interval) {
2061 /* time to retry compression on next call */
2062 sc->sc_state = DNODE_SMARTCOMP_COMPRESSING;
2063 sc->sc_size = 0;
2064 sc->sc_orig_size = 0;
2065 }
2066 }
2067 mutex_exit(&sc->sc_lock);
2068
2069 return (old_state != DNODE_SMARTCOMP_DENYING);
2070 }
2071
2072 /*
2073 * Callback invoked after compression has been performed to allow us to
2074 * monitor compression performance. If we're in a compressing phase, we
2075 * add the uncompressed and compressed data volumes to our state counters
2076 * and see if we need to recheck compression performance in
2077 * smartcomp_check_comp.
2078 */
2079 void
2080 dnode_smartcomp_result_cb(void *userinfo, const zio_t *zio)
2081 {
2082 dnode_t *dn = userinfo;
2083 dnode_smartcomp_t *sc;
2084 uint64_t io_size = zio->io_size, io_orig_size = zio->io_orig_size;
2085
2086 ASSERT(dn != NULL);
2087 sc = &dn->dn_smartcomp;
2088
2089 if (io_orig_size == 0)
2090 /* XXX: is this valid anyway? */
2091 return;
2092
2093 mutex_enter(&sc->sc_lock);
2094 if (sc->sc_state == DNODE_SMARTCOMP_COMPRESSING) {
2095 /* add last block's compression performance to our stats */
2096 sc->sc_size += io_size;
2097 sc->sc_orig_size += io_orig_size;
2098 /* time to recheck compression performance? */
2099 if (sc->sc_orig_size >= zfs_smartcomp_interval)
2100 smartcomp_check_comp(sc);
2101 }
2102 mutex_exit(&sc->sc_lock);
2103 }
2104
2105 /*
2106 * This function checks whether the compression we've been getting is above
2107 * the threshold value. If it is, we decrement the sc_comp_failures counter
2108 * to indicate compression success. If it isn't we increment the same
2109 * counter and potentially start a compression deny phase.
2110 */
2111 static void
2112 smartcomp_check_comp(dnode_smartcomp_t *sc)
2113 {
2114 uint64_t threshold = sc->sc_orig_size -
2115 sc->sc_orig_size / zfs_smartcomp_threshold_factor;
2116
2117 ASSERT(MUTEX_HELD(&sc->sc_lock));
2118 if (sc->sc_size > threshold) {
2119 sc->sc_comp_failures =
2120 MIN(sc->sc_comp_failures + 1, zfs_smartcomp_interval_exp);
2121 if (sc->sc_comp_failures > 0) {
2122 /* consistently getting too little compression, stop */
2123 sc->sc_state = DNODE_SMARTCOMP_DENYING;
2124 sc->sc_deny_interval =
2125 zfs_smartcomp_interval << sc->sc_comp_failures;
2126 /* randomize the interval by +-10% to avoid patterns */
2127 sc->sc_deny_interval = (sc->sc_deny_interval -
2128 (sc->sc_deny_interval / 10)) +
2129 spa_get_random(sc->sc_deny_interval / 5 + 1);
2130 }
2131 } else {
2132 if (sc->sc_comp_failures > 0) {
2133 /*
2134 * We're biased for compression, so any success makes
2135 * us forget the file's past incompressibility.
2136 */
2137 sc->sc_comp_failures = 0;
2138 } else {
2139 sc->sc_comp_failures = MAX(sc->sc_comp_failures - 1,
2140 -zfs_smartcomp_interval_exp);
2141 }
2142 }
2143 /* reset state counters */
2144 sc->sc_size = 0;
2145 sc->sc_orig_size = 0;
2146 }
2147
2148 /*
2149 * Prepares a zio_smartcomp_info_t structure for passing to zio_write or
2150 * arc_write depending on whether smart compression should be applied to
2151 * the specified objset, dnode and buffer.
2152 */
2153 extern void
2154 dnode_setup_zio_smartcomp(dmu_buf_impl_t *db, zio_smartcomp_info_t *sc)
2155 {
2156 dnode_t *dn = DB_DNODE(db);
2157 objset_t *os = dn->dn_objset;
2158
2159 /* Only do smart compression on user data of plain files. */
2160 if (dn->dn_type == DMU_OT_PLAIN_FILE_CONTENTS && db->db_level == 0 &&
2161 os->os_smartcomp_enabled && os->os_compress != ZIO_COMPRESS_OFF) {
2162 sc->sc_ask = dnode_smartcomp_ask_cb;
2163 sc->sc_result = dnode_smartcomp_result_cb;
2164 sc->sc_userinfo = dn;
2165 } else {
2166 /*
2167 * Zeroing out the structure passed to zio_write will turn
2168 * smart compression off.
2169 */
2170 bzero(sc, sizeof (*sc));
2171 }
2172 }