1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21 /*
22 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
23 * Copyright (c) 2012, 2014 by Delphix. All rights reserved.
24 */
25
26 #include <sys/zfs_context.h>
27 #include <sys/dbuf.h>
28 #include <sys/dnode.h>
29 #include <sys/dmu.h>
30 #include <sys/dmu_impl.h>
31 #include <sys/dmu_tx.h>
32 #include <sys/dmu_objset.h>
33 #include <sys/dsl_dir.h>
34 #include <sys/dsl_dataset.h>
35 #include <sys/spa.h>
36 #include <sys/zio.h>
37 #include <sys/dmu_zfetch.h>
38 #include <sys/range_tree.h>
39
40 static kmem_cache_t *dnode_cache;
41 /*
42 * Define DNODE_STATS to turn on statistic gathering. By default, it is only
43 * turned on when DEBUG is also defined.
44 */
45 #ifdef DEBUG
46 #define DNODE_STATS
47 #endif /* DEBUG */
48
49 #ifdef DNODE_STATS
50 #define DNODE_STAT_ADD(stat) ((stat)++)
51 #else
52 #define DNODE_STAT_ADD(stat) /* nothing */
53 #endif /* DNODE_STATS */
54
55 static dnode_phys_t dnode_phys_zero;
56
57 int zfs_default_bs = SPA_MINBLOCKSHIFT;
58 int zfs_default_ibs = DN_MAX_INDBLKSHIFT;
59
60 static kmem_cbrc_t dnode_move(void *, void *, size_t, void *);
61
62 static int
63 dbuf_compare(const void *x1, const void *x2)
64 {
65 const dmu_buf_impl_t *d1 = x1;
66 const dmu_buf_impl_t *d2 = x2;
67
68 if (d1->db_level < d2->db_level) {
69 return (-1);
70 }
71 if (d1->db_level > d2->db_level) {
72 return (1);
73 }
74
75 if (d1->db_blkid < d2->db_blkid) {
76 return (-1);
77 }
78 if (d1->db_blkid > d2->db_blkid) {
79 return (1);
80 }
81
82 if (d1->db_state == DB_SEARCH) {
83 ASSERT3S(d2->db_state, !=, DB_SEARCH);
84 return (-1);
85 } else if (d2->db_state == DB_SEARCH) {
86 ASSERT3S(d1->db_state, !=, DB_SEARCH);
87 return (1);
88 }
89
90 if ((uintptr_t)d1 < (uintptr_t)d2) {
91 return (-1);
92 }
93 if ((uintptr_t)d1 > (uintptr_t)d2) {
94 return (1);
95 }
96 return (0);
97 }
98
99 /* ARGSUSED */
100 static int
101 dnode_cons(void *arg, void *unused, int kmflag)
102 {
103 dnode_t *dn = arg;
104 int i;
105
106 rw_init(&dn->dn_struct_rwlock, NULL, RW_DEFAULT, NULL);
107 mutex_init(&dn->dn_mtx, NULL, MUTEX_DEFAULT, NULL);
108 mutex_init(&dn->dn_dbufs_mtx, NULL, MUTEX_DEFAULT, NULL);
109 cv_init(&dn->dn_notxholds, NULL, CV_DEFAULT, NULL);
110
111 /*
112 * Every dbuf has a reference, and dropping a tracked reference is
113 * O(number of references), so don't track dn_holds.
114 */
115 refcount_create_untracked(&dn->dn_holds);
116 refcount_create(&dn->dn_tx_holds);
117 list_link_init(&dn->dn_link);
118
119 bzero(&dn->dn_next_nblkptr[0], sizeof (dn->dn_next_nblkptr));
120 bzero(&dn->dn_next_nlevels[0], sizeof (dn->dn_next_nlevels));
121 bzero(&dn->dn_next_indblkshift[0], sizeof (dn->dn_next_indblkshift));
122 bzero(&dn->dn_next_bonustype[0], sizeof (dn->dn_next_bonustype));
123 bzero(&dn->dn_rm_spillblk[0], sizeof (dn->dn_rm_spillblk));
124 bzero(&dn->dn_next_bonuslen[0], sizeof (dn->dn_next_bonuslen));
125 bzero(&dn->dn_next_blksz[0], sizeof (dn->dn_next_blksz));
126
127 for (i = 0; i < TXG_SIZE; i++) {
128 list_link_init(&dn->dn_dirty_link[i]);
129 dn->dn_free_ranges[i] = NULL;
130 list_create(&dn->dn_dirty_records[i],
131 sizeof (dbuf_dirty_record_t),
132 offsetof(dbuf_dirty_record_t, dr_dirty_node));
133 }
134
135 dn->dn_allocated_txg = 0;
136 dn->dn_free_txg = 0;
137 dn->dn_assigned_txg = 0;
138 dn->dn_dirtyctx = 0;
139 dn->dn_dirtyctx_firstset = NULL;
140 dn->dn_bonus = NULL;
141 dn->dn_have_spill = B_FALSE;
142 dn->dn_zio = NULL;
143 dn->dn_oldused = 0;
144 dn->dn_oldflags = 0;
145 dn->dn_olduid = 0;
146 dn->dn_oldgid = 0;
147 dn->dn_newuid = 0;
148 dn->dn_newgid = 0;
149 dn->dn_id_flags = 0;
150
151 dn->dn_dbufs_count = 0;
152 dn->dn_unlisted_l0_blkid = 0;
153 avl_create(&dn->dn_dbufs, dbuf_compare, sizeof (dmu_buf_impl_t),
154 offsetof(dmu_buf_impl_t, db_link));
155
156 dn->dn_moved = 0;
157 return (0);
158 }
159
160 /* ARGSUSED */
161 static void
162 dnode_dest(void *arg, void *unused)
163 {
164 int i;
165 dnode_t *dn = arg;
166
167 rw_destroy(&dn->dn_struct_rwlock);
168 mutex_destroy(&dn->dn_mtx);
169 mutex_destroy(&dn->dn_dbufs_mtx);
170 cv_destroy(&dn->dn_notxholds);
171 refcount_destroy(&dn->dn_holds);
172 refcount_destroy(&dn->dn_tx_holds);
173 ASSERT(!list_link_active(&dn->dn_link));
174
175 for (i = 0; i < TXG_SIZE; i++) {
176 ASSERT(!list_link_active(&dn->dn_dirty_link[i]));
177 ASSERT3P(dn->dn_free_ranges[i], ==, NULL);
178 list_destroy(&dn->dn_dirty_records[i]);
179 ASSERT0(dn->dn_next_nblkptr[i]);
180 ASSERT0(dn->dn_next_nlevels[i]);
181 ASSERT0(dn->dn_next_indblkshift[i]);
182 ASSERT0(dn->dn_next_bonustype[i]);
183 ASSERT0(dn->dn_rm_spillblk[i]);
184 ASSERT0(dn->dn_next_bonuslen[i]);
185 ASSERT0(dn->dn_next_blksz[i]);
186 }
187
188 ASSERT0(dn->dn_allocated_txg);
189 ASSERT0(dn->dn_free_txg);
190 ASSERT0(dn->dn_assigned_txg);
191 ASSERT0(dn->dn_dirtyctx);
192 ASSERT3P(dn->dn_dirtyctx_firstset, ==, NULL);
193 ASSERT3P(dn->dn_bonus, ==, NULL);
194 ASSERT(!dn->dn_have_spill);
195 ASSERT3P(dn->dn_zio, ==, NULL);
196 ASSERT0(dn->dn_oldused);
197 ASSERT0(dn->dn_oldflags);
198 ASSERT0(dn->dn_olduid);
199 ASSERT0(dn->dn_oldgid);
200 ASSERT0(dn->dn_newuid);
201 ASSERT0(dn->dn_newgid);
202 ASSERT0(dn->dn_id_flags);
203
204 ASSERT0(dn->dn_dbufs_count);
205 ASSERT0(dn->dn_unlisted_l0_blkid);
206 avl_destroy(&dn->dn_dbufs);
207 }
208
209 void
210 dnode_init(void)
211 {
212 ASSERT(dnode_cache == NULL);
213 dnode_cache = kmem_cache_create("dnode_t",
214 sizeof (dnode_t),
215 0, dnode_cons, dnode_dest, NULL, NULL, NULL, 0);
216 kmem_cache_set_move(dnode_cache, dnode_move);
217 }
218
219 void
220 dnode_fini(void)
221 {
222 kmem_cache_destroy(dnode_cache);
223 dnode_cache = NULL;
224 }
225
226
227 #ifdef ZFS_DEBUG
228 void
229 dnode_verify(dnode_t *dn)
230 {
231 int drop_struct_lock = FALSE;
232
233 ASSERT(dn->dn_phys);
234 ASSERT(dn->dn_objset);
235 ASSERT(dn->dn_handle->dnh_dnode == dn);
236
237 ASSERT(DMU_OT_IS_VALID(dn->dn_phys->dn_type));
238
239 if (!(zfs_flags & ZFS_DEBUG_DNODE_VERIFY))
240 return;
241
242 if (!RW_WRITE_HELD(&dn->dn_struct_rwlock)) {
243 rw_enter(&dn->dn_struct_rwlock, RW_READER);
244 drop_struct_lock = TRUE;
245 }
246 if (dn->dn_phys->dn_type != DMU_OT_NONE || dn->dn_allocated_txg != 0) {
247 int i;
248 ASSERT3U(dn->dn_indblkshift, >=, 0);
249 ASSERT3U(dn->dn_indblkshift, <=, SPA_MAXBLOCKSHIFT);
250 if (dn->dn_datablkshift) {
251 ASSERT3U(dn->dn_datablkshift, >=, SPA_MINBLOCKSHIFT);
252 ASSERT3U(dn->dn_datablkshift, <=, SPA_MAXBLOCKSHIFT);
253 ASSERT3U(1<<dn->dn_datablkshift, ==, dn->dn_datablksz);
254 }
255 ASSERT3U(dn->dn_nlevels, <=, 30);
256 ASSERT(DMU_OT_IS_VALID(dn->dn_type));
257 ASSERT3U(dn->dn_nblkptr, >=, 1);
258 ASSERT3U(dn->dn_nblkptr, <=, DN_MAX_NBLKPTR);
259 ASSERT3U(dn->dn_bonuslen, <=, DN_MAX_BONUSLEN);
260 ASSERT3U(dn->dn_datablksz, ==,
261 dn->dn_datablkszsec << SPA_MINBLOCKSHIFT);
262 ASSERT3U(ISP2(dn->dn_datablksz), ==, dn->dn_datablkshift != 0);
263 ASSERT3U((dn->dn_nblkptr - 1) * sizeof (blkptr_t) +
264 dn->dn_bonuslen, <=, DN_MAX_BONUSLEN);
265 for (i = 0; i < TXG_SIZE; i++) {
266 ASSERT3U(dn->dn_next_nlevels[i], <=, dn->dn_nlevels);
267 }
268 }
269 if (dn->dn_phys->dn_type != DMU_OT_NONE)
270 ASSERT3U(dn->dn_phys->dn_nlevels, <=, dn->dn_nlevels);
271 ASSERT(DMU_OBJECT_IS_SPECIAL(dn->dn_object) || dn->dn_dbuf != NULL);
272 if (dn->dn_dbuf != NULL) {
273 ASSERT3P(dn->dn_phys, ==,
274 (dnode_phys_t *)dn->dn_dbuf->db.db_data +
275 (dn->dn_object % (dn->dn_dbuf->db.db_size >> DNODE_SHIFT)));
276 }
277 if (drop_struct_lock)
278 rw_exit(&dn->dn_struct_rwlock);
279 }
280 #endif
281
282 void
283 dnode_byteswap(dnode_phys_t *dnp)
284 {
285 uint64_t *buf64 = (void*)&dnp->dn_blkptr;
286 int i;
287
288 if (dnp->dn_type == DMU_OT_NONE) {
289 bzero(dnp, sizeof (dnode_phys_t));
290 return;
291 }
292
293 dnp->dn_datablkszsec = BSWAP_16(dnp->dn_datablkszsec);
294 dnp->dn_bonuslen = BSWAP_16(dnp->dn_bonuslen);
295 dnp->dn_maxblkid = BSWAP_64(dnp->dn_maxblkid);
296 dnp->dn_used = BSWAP_64(dnp->dn_used);
297
298 /*
299 * dn_nblkptr is only one byte, so it's OK to read it in either
300 * byte order. We can't read dn_bouslen.
301 */
302 ASSERT(dnp->dn_indblkshift <= SPA_MAXBLOCKSHIFT);
303 ASSERT(dnp->dn_nblkptr <= DN_MAX_NBLKPTR);
304 for (i = 0; i < dnp->dn_nblkptr * sizeof (blkptr_t)/8; i++)
305 buf64[i] = BSWAP_64(buf64[i]);
306
307 /*
308 * OK to check dn_bonuslen for zero, because it won't matter if
309 * we have the wrong byte order. This is necessary because the
310 * dnode dnode is smaller than a regular dnode.
311 */
312 if (dnp->dn_bonuslen != 0) {
313 /*
314 * Note that the bonus length calculated here may be
315 * longer than the actual bonus buffer. This is because
316 * we always put the bonus buffer after the last block
317 * pointer (instead of packing it against the end of the
318 * dnode buffer).
319 */
320 int off = (dnp->dn_nblkptr-1) * sizeof (blkptr_t);
321 size_t len = DN_MAX_BONUSLEN - off;
322 ASSERT(DMU_OT_IS_VALID(dnp->dn_bonustype));
323 dmu_object_byteswap_t byteswap =
324 DMU_OT_BYTESWAP(dnp->dn_bonustype);
325 dmu_ot_byteswap[byteswap].ob_func(dnp->dn_bonus + off, len);
326 }
327
328 /* Swap SPILL block if we have one */
329 if (dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR)
330 byteswap_uint64_array(&dnp->dn_spill, sizeof (blkptr_t));
331
332 }
333
334 void
335 dnode_buf_byteswap(void *vbuf, size_t size)
336 {
337 dnode_phys_t *buf = vbuf;
338 int i;
339
340 ASSERT3U(sizeof (dnode_phys_t), ==, (1<<DNODE_SHIFT));
341 ASSERT((size & (sizeof (dnode_phys_t)-1)) == 0);
342
343 size >>= DNODE_SHIFT;
344 for (i = 0; i < size; i++) {
345 dnode_byteswap(buf);
346 buf++;
347 }
348 }
349
350 void
351 dnode_setbonuslen(dnode_t *dn, int newsize, dmu_tx_t *tx)
352 {
353 ASSERT3U(refcount_count(&dn->dn_holds), >=, 1);
354
355 dnode_setdirty(dn, tx);
356 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
357 ASSERT3U(newsize, <=, DN_MAX_BONUSLEN -
358 (dn->dn_nblkptr-1) * sizeof (blkptr_t));
359 dn->dn_bonuslen = newsize;
360 if (newsize == 0)
361 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = DN_ZERO_BONUSLEN;
362 else
363 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = dn->dn_bonuslen;
364 rw_exit(&dn->dn_struct_rwlock);
365 }
366
367 void
368 dnode_setbonus_type(dnode_t *dn, dmu_object_type_t newtype, dmu_tx_t *tx)
369 {
370 ASSERT3U(refcount_count(&dn->dn_holds), >=, 1);
371 dnode_setdirty(dn, tx);
372 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
373 dn->dn_bonustype = newtype;
374 dn->dn_next_bonustype[tx->tx_txg & TXG_MASK] = dn->dn_bonustype;
375 rw_exit(&dn->dn_struct_rwlock);
376 }
377
378 void
379 dnode_rm_spill(dnode_t *dn, dmu_tx_t *tx)
380 {
381 ASSERT3U(refcount_count(&dn->dn_holds), >=, 1);
382 ASSERT(RW_WRITE_HELD(&dn->dn_struct_rwlock));
383 dnode_setdirty(dn, tx);
384 dn->dn_rm_spillblk[tx->tx_txg&TXG_MASK] = DN_KILL_SPILLBLK;
385 dn->dn_have_spill = B_FALSE;
386 }
387
388 static void
389 dnode_setdblksz(dnode_t *dn, int size)
390 {
391 ASSERT0(P2PHASE(size, SPA_MINBLOCKSIZE));
392 ASSERT3U(size, <=, SPA_MAXBLOCKSIZE);
393 ASSERT3U(size, >=, SPA_MINBLOCKSIZE);
394 ASSERT3U(size >> SPA_MINBLOCKSHIFT, <,
395 1<<(sizeof (dn->dn_phys->dn_datablkszsec) * 8));
396 dn->dn_datablksz = size;
397 dn->dn_datablkszsec = size >> SPA_MINBLOCKSHIFT;
398 dn->dn_datablkshift = ISP2(size) ? highbit64(size - 1) : 0;
399 }
400
401 static dnode_t *
402 dnode_create(objset_t *os, dnode_phys_t *dnp, dmu_buf_impl_t *db,
403 uint64_t object, dnode_handle_t *dnh)
404 {
405 dnode_t *dn = kmem_cache_alloc(dnode_cache, KM_SLEEP);
406
407 ASSERT(!POINTER_IS_VALID(dn->dn_objset));
408 dn->dn_moved = 0;
409
410 /*
411 * Defer setting dn_objset until the dnode is ready to be a candidate
412 * for the dnode_move() callback.
413 */
414 dn->dn_object = object;
415 dn->dn_dbuf = db;
416 dn->dn_handle = dnh;
417 dn->dn_phys = dnp;
418
419 if (dnp->dn_datablkszsec) {
420 dnode_setdblksz(dn, dnp->dn_datablkszsec << SPA_MINBLOCKSHIFT);
421 } else {
422 dn->dn_datablksz = 0;
423 dn->dn_datablkszsec = 0;
424 dn->dn_datablkshift = 0;
425 }
426 dn->dn_indblkshift = dnp->dn_indblkshift;
427 dn->dn_nlevels = dnp->dn_nlevels;
428 dn->dn_type = dnp->dn_type;
429 dn->dn_nblkptr = dnp->dn_nblkptr;
430 dn->dn_checksum = dnp->dn_checksum;
431 dn->dn_compress = dnp->dn_compress;
432 dn->dn_bonustype = dnp->dn_bonustype;
433 dn->dn_bonuslen = dnp->dn_bonuslen;
434 dn->dn_maxblkid = dnp->dn_maxblkid;
435 dn->dn_have_spill = ((dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) != 0);
436 dn->dn_id_flags = 0;
437
438 dmu_zfetch_init(&dn->dn_zfetch, dn);
439
440 ASSERT(DMU_OT_IS_VALID(dn->dn_phys->dn_type));
441
442 mutex_enter(&os->os_lock);
443 list_insert_head(&os->os_dnodes, dn);
444 membar_producer();
445 /*
446 * Everything else must be valid before assigning dn_objset makes the
447 * dnode eligible for dnode_move().
448 */
449 dn->dn_objset = os;
450 mutex_exit(&os->os_lock);
451
452 arc_space_consume(sizeof (dnode_t), ARC_SPACE_OTHER);
453 return (dn);
454 }
455
456 /*
457 * Caller must be holding the dnode handle, which is released upon return.
458 */
459 static void
460 dnode_destroy(dnode_t *dn)
461 {
462 objset_t *os = dn->dn_objset;
463
464 ASSERT((dn->dn_id_flags & DN_ID_NEW_EXIST) == 0);
465
466 mutex_enter(&os->os_lock);
467 POINTER_INVALIDATE(&dn->dn_objset);
468 list_remove(&os->os_dnodes, dn);
469 mutex_exit(&os->os_lock);
470
471 /* the dnode can no longer move, so we can release the handle */
472 zrl_remove(&dn->dn_handle->dnh_zrlock);
473
474 dn->dn_allocated_txg = 0;
475 dn->dn_free_txg = 0;
476 dn->dn_assigned_txg = 0;
477
478 dn->dn_dirtyctx = 0;
479 if (dn->dn_dirtyctx_firstset != NULL) {
480 kmem_free(dn->dn_dirtyctx_firstset, 1);
481 dn->dn_dirtyctx_firstset = NULL;
482 }
483 if (dn->dn_bonus != NULL) {
484 mutex_enter(&dn->dn_bonus->db_mtx);
485 dbuf_evict(dn->dn_bonus);
486 dn->dn_bonus = NULL;
487 }
488 dn->dn_zio = NULL;
489
490 dn->dn_have_spill = B_FALSE;
491 dn->dn_oldused = 0;
492 dn->dn_oldflags = 0;
493 dn->dn_olduid = 0;
494 dn->dn_oldgid = 0;
495 dn->dn_newuid = 0;
496 dn->dn_newgid = 0;
497 dn->dn_id_flags = 0;
498 dn->dn_unlisted_l0_blkid = 0;
499
500 dmu_zfetch_rele(&dn->dn_zfetch);
501 kmem_cache_free(dnode_cache, dn);
502 arc_space_return(sizeof (dnode_t), ARC_SPACE_OTHER);
503 }
504
505 void
506 dnode_allocate(dnode_t *dn, dmu_object_type_t ot, int blocksize, int ibs,
507 dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx)
508 {
509 int i;
510
511 ASSERT3U(blocksize, <=,
512 spa_maxblocksize(dmu_objset_spa(dn->dn_objset)));
513 if (blocksize == 0)
514 blocksize = 1 << zfs_default_bs;
515 else
516 blocksize = P2ROUNDUP(blocksize, SPA_MINBLOCKSIZE);
517
518 if (ibs == 0)
519 ibs = zfs_default_ibs;
520
521 ibs = MIN(MAX(ibs, DN_MIN_INDBLKSHIFT), DN_MAX_INDBLKSHIFT);
522
523 dprintf("os=%p obj=%llu txg=%llu blocksize=%d ibs=%d\n", dn->dn_objset,
524 dn->dn_object, tx->tx_txg, blocksize, ibs);
525
526 ASSERT(dn->dn_type == DMU_OT_NONE);
527 ASSERT(bcmp(dn->dn_phys, &dnode_phys_zero, sizeof (dnode_phys_t)) == 0);
528 ASSERT(dn->dn_phys->dn_type == DMU_OT_NONE);
529 ASSERT(ot != DMU_OT_NONE);
530 ASSERT(DMU_OT_IS_VALID(ot));
531 ASSERT((bonustype == DMU_OT_NONE && bonuslen == 0) ||
532 (bonustype == DMU_OT_SA && bonuslen == 0) ||
533 (bonustype != DMU_OT_NONE && bonuslen != 0));
534 ASSERT(DMU_OT_IS_VALID(bonustype));
535 ASSERT3U(bonuslen, <=, DN_MAX_BONUSLEN);
536 ASSERT(dn->dn_type == DMU_OT_NONE);
537 ASSERT0(dn->dn_maxblkid);
538 ASSERT0(dn->dn_allocated_txg);
539 ASSERT0(dn->dn_assigned_txg);
540 ASSERT(refcount_is_zero(&dn->dn_tx_holds));
541 ASSERT3U(refcount_count(&dn->dn_holds), <=, 1);
542 ASSERT(avl_is_empty(&dn->dn_dbufs));
543
544 for (i = 0; i < TXG_SIZE; i++) {
545 ASSERT0(dn->dn_next_nblkptr[i]);
546 ASSERT0(dn->dn_next_nlevels[i]);
547 ASSERT0(dn->dn_next_indblkshift[i]);
548 ASSERT0(dn->dn_next_bonuslen[i]);
549 ASSERT0(dn->dn_next_bonustype[i]);
550 ASSERT0(dn->dn_rm_spillblk[i]);
551 ASSERT0(dn->dn_next_blksz[i]);
552 ASSERT(!list_link_active(&dn->dn_dirty_link[i]));
553 ASSERT3P(list_head(&dn->dn_dirty_records[i]), ==, NULL);
554 ASSERT3P(dn->dn_free_ranges[i], ==, NULL);
555 }
556
557 dn->dn_type = ot;
558 dnode_setdblksz(dn, blocksize);
559 dn->dn_indblkshift = ibs;
560 dn->dn_nlevels = 1;
561 if (bonustype == DMU_OT_SA) /* Maximize bonus space for SA */
562 dn->dn_nblkptr = 1;
563 else
564 dn->dn_nblkptr = 1 +
565 ((DN_MAX_BONUSLEN - bonuslen) >> SPA_BLKPTRSHIFT);
566 dn->dn_bonustype = bonustype;
567 dn->dn_bonuslen = bonuslen;
568 dn->dn_checksum = ZIO_CHECKSUM_INHERIT;
569 dn->dn_compress = ZIO_COMPRESS_INHERIT;
570 dn->dn_dirtyctx = 0;
571
572 dn->dn_free_txg = 0;
573 if (dn->dn_dirtyctx_firstset) {
574 kmem_free(dn->dn_dirtyctx_firstset, 1);
575 dn->dn_dirtyctx_firstset = NULL;
576 }
577
578 dn->dn_allocated_txg = tx->tx_txg;
579 dn->dn_id_flags = 0;
580
581 dnode_setdirty(dn, tx);
582 dn->dn_next_indblkshift[tx->tx_txg & TXG_MASK] = ibs;
583 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = dn->dn_bonuslen;
584 dn->dn_next_bonustype[tx->tx_txg & TXG_MASK] = dn->dn_bonustype;
585 dn->dn_next_blksz[tx->tx_txg & TXG_MASK] = dn->dn_datablksz;
586 }
587
588 void
589 dnode_reallocate(dnode_t *dn, dmu_object_type_t ot, int blocksize,
590 dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx)
591 {
592 int nblkptr;
593
594 ASSERT3U(blocksize, >=, SPA_MINBLOCKSIZE);
595 ASSERT3U(blocksize, <=,
596 spa_maxblocksize(dmu_objset_spa(dn->dn_objset)));
597 ASSERT0(blocksize % SPA_MINBLOCKSIZE);
598 ASSERT(dn->dn_object != DMU_META_DNODE_OBJECT || dmu_tx_private_ok(tx));
599 ASSERT(tx->tx_txg != 0);
600 ASSERT((bonustype == DMU_OT_NONE && bonuslen == 0) ||
601 (bonustype != DMU_OT_NONE && bonuslen != 0) ||
602 (bonustype == DMU_OT_SA && bonuslen == 0));
603 ASSERT(DMU_OT_IS_VALID(bonustype));
604 ASSERT3U(bonuslen, <=, DN_MAX_BONUSLEN);
605
606 /* clean up any unreferenced dbufs */
607 dnode_evict_dbufs(dn);
608
609 dn->dn_id_flags = 0;
610
611 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
612 dnode_setdirty(dn, tx);
613 if (dn->dn_datablksz != blocksize) {
614 /* change blocksize */
615 ASSERT(dn->dn_maxblkid == 0 &&
616 (BP_IS_HOLE(&dn->dn_phys->dn_blkptr[0]) ||
617 dnode_block_freed(dn, 0)));
618 dnode_setdblksz(dn, blocksize);
619 dn->dn_next_blksz[tx->tx_txg&TXG_MASK] = blocksize;
620 }
621 if (dn->dn_bonuslen != bonuslen)
622 dn->dn_next_bonuslen[tx->tx_txg&TXG_MASK] = bonuslen;
623
624 if (bonustype == DMU_OT_SA) /* Maximize bonus space for SA */
625 nblkptr = 1;
626 else
627 nblkptr = 1 + ((DN_MAX_BONUSLEN - bonuslen) >> SPA_BLKPTRSHIFT);
628 if (dn->dn_bonustype != bonustype)
629 dn->dn_next_bonustype[tx->tx_txg&TXG_MASK] = bonustype;
630 if (dn->dn_nblkptr != nblkptr)
631 dn->dn_next_nblkptr[tx->tx_txg&TXG_MASK] = nblkptr;
632 if (dn->dn_phys->dn_flags & DNODE_FLAG_SPILL_BLKPTR) {
633 dbuf_rm_spill(dn, tx);
634 dnode_rm_spill(dn, tx);
635 }
636 rw_exit(&dn->dn_struct_rwlock);
637
638 /* change type */
639 dn->dn_type = ot;
640
641 /* change bonus size and type */
642 mutex_enter(&dn->dn_mtx);
643 dn->dn_bonustype = bonustype;
644 dn->dn_bonuslen = bonuslen;
645 dn->dn_nblkptr = nblkptr;
646 dn->dn_checksum = ZIO_CHECKSUM_INHERIT;
647 dn->dn_compress = ZIO_COMPRESS_INHERIT;
648 ASSERT3U(dn->dn_nblkptr, <=, DN_MAX_NBLKPTR);
649
650 /* fix up the bonus db_size */
651 if (dn->dn_bonus) {
652 dn->dn_bonus->db.db_size =
653 DN_MAX_BONUSLEN - (dn->dn_nblkptr-1) * sizeof (blkptr_t);
654 ASSERT(dn->dn_bonuslen <= dn->dn_bonus->db.db_size);
655 }
656
657 dn->dn_allocated_txg = tx->tx_txg;
658 mutex_exit(&dn->dn_mtx);
659 }
660
661 #ifdef DNODE_STATS
662 static struct {
663 uint64_t dms_dnode_invalid;
664 uint64_t dms_dnode_recheck1;
665 uint64_t dms_dnode_recheck2;
666 uint64_t dms_dnode_special;
667 uint64_t dms_dnode_handle;
668 uint64_t dms_dnode_rwlock;
669 uint64_t dms_dnode_active;
670 } dnode_move_stats;
671 #endif /* DNODE_STATS */
672
673 static void
674 dnode_move_impl(dnode_t *odn, dnode_t *ndn)
675 {
676 int i;
677
678 ASSERT(!RW_LOCK_HELD(&odn->dn_struct_rwlock));
679 ASSERT(MUTEX_NOT_HELD(&odn->dn_mtx));
680 ASSERT(MUTEX_NOT_HELD(&odn->dn_dbufs_mtx));
681 ASSERT(!RW_LOCK_HELD(&odn->dn_zfetch.zf_rwlock));
682
683 /* Copy fields. */
684 ndn->dn_objset = odn->dn_objset;
685 ndn->dn_object = odn->dn_object;
686 ndn->dn_dbuf = odn->dn_dbuf;
687 ndn->dn_handle = odn->dn_handle;
688 ndn->dn_phys = odn->dn_phys;
689 ndn->dn_type = odn->dn_type;
690 ndn->dn_bonuslen = odn->dn_bonuslen;
691 ndn->dn_bonustype = odn->dn_bonustype;
692 ndn->dn_nblkptr = odn->dn_nblkptr;
693 ndn->dn_checksum = odn->dn_checksum;
694 ndn->dn_compress = odn->dn_compress;
695 ndn->dn_nlevels = odn->dn_nlevels;
696 ndn->dn_indblkshift = odn->dn_indblkshift;
697 ndn->dn_datablkshift = odn->dn_datablkshift;
698 ndn->dn_datablkszsec = odn->dn_datablkszsec;
699 ndn->dn_datablksz = odn->dn_datablksz;
700 ndn->dn_maxblkid = odn->dn_maxblkid;
701 bcopy(&odn->dn_next_nblkptr[0], &ndn->dn_next_nblkptr[0],
702 sizeof (odn->dn_next_nblkptr));
703 bcopy(&odn->dn_next_nlevels[0], &ndn->dn_next_nlevels[0],
704 sizeof (odn->dn_next_nlevels));
705 bcopy(&odn->dn_next_indblkshift[0], &ndn->dn_next_indblkshift[0],
706 sizeof (odn->dn_next_indblkshift));
707 bcopy(&odn->dn_next_bonustype[0], &ndn->dn_next_bonustype[0],
708 sizeof (odn->dn_next_bonustype));
709 bcopy(&odn->dn_rm_spillblk[0], &ndn->dn_rm_spillblk[0],
710 sizeof (odn->dn_rm_spillblk));
711 bcopy(&odn->dn_next_bonuslen[0], &ndn->dn_next_bonuslen[0],
712 sizeof (odn->dn_next_bonuslen));
713 bcopy(&odn->dn_next_blksz[0], &ndn->dn_next_blksz[0],
714 sizeof (odn->dn_next_blksz));
715 for (i = 0; i < TXG_SIZE; i++) {
716 list_move_tail(&ndn->dn_dirty_records[i],
717 &odn->dn_dirty_records[i]);
718 }
719 bcopy(&odn->dn_free_ranges[0], &ndn->dn_free_ranges[0],
720 sizeof (odn->dn_free_ranges));
721 ndn->dn_allocated_txg = odn->dn_allocated_txg;
722 ndn->dn_free_txg = odn->dn_free_txg;
723 ndn->dn_assigned_txg = odn->dn_assigned_txg;
724 ndn->dn_dirtyctx = odn->dn_dirtyctx;
725 ndn->dn_dirtyctx_firstset = odn->dn_dirtyctx_firstset;
726 ASSERT(refcount_count(&odn->dn_tx_holds) == 0);
727 refcount_transfer(&ndn->dn_holds, &odn->dn_holds);
728 ASSERT(avl_is_empty(&ndn->dn_dbufs));
729 avl_swap(&ndn->dn_dbufs, &odn->dn_dbufs);
730 ndn->dn_dbufs_count = odn->dn_dbufs_count;
731 ndn->dn_unlisted_l0_blkid = odn->dn_unlisted_l0_blkid;
732 ndn->dn_bonus = odn->dn_bonus;
733 ndn->dn_have_spill = odn->dn_have_spill;
734 ndn->dn_zio = odn->dn_zio;
735 ndn->dn_oldused = odn->dn_oldused;
736 ndn->dn_oldflags = odn->dn_oldflags;
737 ndn->dn_olduid = odn->dn_olduid;
738 ndn->dn_oldgid = odn->dn_oldgid;
739 ndn->dn_newuid = odn->dn_newuid;
740 ndn->dn_newgid = odn->dn_newgid;
741 ndn->dn_id_flags = odn->dn_id_flags;
742 dmu_zfetch_init(&ndn->dn_zfetch, NULL);
743 list_move_tail(&ndn->dn_zfetch.zf_stream, &odn->dn_zfetch.zf_stream);
744 ndn->dn_zfetch.zf_dnode = odn->dn_zfetch.zf_dnode;
745 ndn->dn_zfetch.zf_stream_cnt = odn->dn_zfetch.zf_stream_cnt;
746 ndn->dn_zfetch.zf_alloc_fail = odn->dn_zfetch.zf_alloc_fail;
747
748 /*
749 * Update back pointers. Updating the handle fixes the back pointer of
750 * every descendant dbuf as well as the bonus dbuf.
751 */
752 ASSERT(ndn->dn_handle->dnh_dnode == odn);
753 ndn->dn_handle->dnh_dnode = ndn;
754 if (ndn->dn_zfetch.zf_dnode == odn) {
755 ndn->dn_zfetch.zf_dnode = ndn;
756 }
757
758 /*
759 * Invalidate the original dnode by clearing all of its back pointers.
760 */
761 odn->dn_dbuf = NULL;
762 odn->dn_handle = NULL;
763 avl_create(&odn->dn_dbufs, dbuf_compare, sizeof (dmu_buf_impl_t),
764 offsetof(dmu_buf_impl_t, db_link));
765 odn->dn_dbufs_count = 0;
766 odn->dn_unlisted_l0_blkid = 0;
767 odn->dn_bonus = NULL;
768 odn->dn_zfetch.zf_dnode = NULL;
769
770 /*
771 * Set the low bit of the objset pointer to ensure that dnode_move()
772 * recognizes the dnode as invalid in any subsequent callback.
773 */
774 POINTER_INVALIDATE(&odn->dn_objset);
775
776 /*
777 * Satisfy the destructor.
778 */
779 for (i = 0; i < TXG_SIZE; i++) {
780 list_create(&odn->dn_dirty_records[i],
781 sizeof (dbuf_dirty_record_t),
782 offsetof(dbuf_dirty_record_t, dr_dirty_node));
783 odn->dn_free_ranges[i] = NULL;
784 odn->dn_next_nlevels[i] = 0;
785 odn->dn_next_indblkshift[i] = 0;
786 odn->dn_next_bonustype[i] = 0;
787 odn->dn_rm_spillblk[i] = 0;
788 odn->dn_next_bonuslen[i] = 0;
789 odn->dn_next_blksz[i] = 0;
790 }
791 odn->dn_allocated_txg = 0;
792 odn->dn_free_txg = 0;
793 odn->dn_assigned_txg = 0;
794 odn->dn_dirtyctx = 0;
795 odn->dn_dirtyctx_firstset = NULL;
796 odn->dn_have_spill = B_FALSE;
797 odn->dn_zio = NULL;
798 odn->dn_oldused = 0;
799 odn->dn_oldflags = 0;
800 odn->dn_olduid = 0;
801 odn->dn_oldgid = 0;
802 odn->dn_newuid = 0;
803 odn->dn_newgid = 0;
804 odn->dn_id_flags = 0;
805
806 /*
807 * Mark the dnode.
808 */
809 ndn->dn_moved = 1;
810 odn->dn_moved = (uint8_t)-1;
811 }
812
813 #ifdef _KERNEL
814 /*ARGSUSED*/
815 static kmem_cbrc_t
816 dnode_move(void *buf, void *newbuf, size_t size, void *arg)
817 {
818 dnode_t *odn = buf, *ndn = newbuf;
819 objset_t *os;
820 int64_t refcount;
821 uint32_t dbufs;
822
823 /*
824 * The dnode is on the objset's list of known dnodes if the objset
825 * pointer is valid. We set the low bit of the objset pointer when
826 * freeing the dnode to invalidate it, and the memory patterns written
827 * by kmem (baddcafe and deadbeef) set at least one of the two low bits.
828 * A newly created dnode sets the objset pointer last of all to indicate
829 * that the dnode is known and in a valid state to be moved by this
830 * function.
831 */
832 os = odn->dn_objset;
833 if (!POINTER_IS_VALID(os)) {
834 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_invalid);
835 return (KMEM_CBRC_DONT_KNOW);
836 }
837
838 /*
839 * Ensure that the objset does not go away during the move.
840 */
841 rw_enter(&os_lock, RW_WRITER);
842 if (os != odn->dn_objset) {
843 rw_exit(&os_lock);
844 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_recheck1);
845 return (KMEM_CBRC_DONT_KNOW);
846 }
847
848 /*
849 * If the dnode is still valid, then so is the objset. We know that no
850 * valid objset can be freed while we hold os_lock, so we can safely
851 * ensure that the objset remains in use.
852 */
853 mutex_enter(&os->os_lock);
854
855 /*
856 * Recheck the objset pointer in case the dnode was removed just before
857 * acquiring the lock.
858 */
859 if (os != odn->dn_objset) {
860 mutex_exit(&os->os_lock);
861 rw_exit(&os_lock);
862 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_recheck2);
863 return (KMEM_CBRC_DONT_KNOW);
864 }
865
866 /*
867 * At this point we know that as long as we hold os->os_lock, the dnode
868 * cannot be freed and fields within the dnode can be safely accessed.
869 * The objset listing this dnode cannot go away as long as this dnode is
870 * on its list.
871 */
872 rw_exit(&os_lock);
873 if (DMU_OBJECT_IS_SPECIAL(odn->dn_object)) {
874 mutex_exit(&os->os_lock);
875 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_special);
876 return (KMEM_CBRC_NO);
877 }
878 ASSERT(odn->dn_dbuf != NULL); /* only "special" dnodes have no parent */
879
880 /*
881 * Lock the dnode handle to prevent the dnode from obtaining any new
882 * holds. This also prevents the descendant dbufs and the bonus dbuf
883 * from accessing the dnode, so that we can discount their holds. The
884 * handle is safe to access because we know that while the dnode cannot
885 * go away, neither can its handle. Once we hold dnh_zrlock, we can
886 * safely move any dnode referenced only by dbufs.
887 */
888 if (!zrl_tryenter(&odn->dn_handle->dnh_zrlock)) {
889 mutex_exit(&os->os_lock);
890 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_handle);
891 return (KMEM_CBRC_LATER);
892 }
893
894 /*
895 * Ensure a consistent view of the dnode's holds and the dnode's dbufs.
896 * We need to guarantee that there is a hold for every dbuf in order to
897 * determine whether the dnode is actively referenced. Falsely matching
898 * a dbuf to an active hold would lead to an unsafe move. It's possible
899 * that a thread already having an active dnode hold is about to add a
900 * dbuf, and we can't compare hold and dbuf counts while the add is in
901 * progress.
902 */
903 if (!rw_tryenter(&odn->dn_struct_rwlock, RW_WRITER)) {
904 zrl_exit(&odn->dn_handle->dnh_zrlock);
905 mutex_exit(&os->os_lock);
906 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_rwlock);
907 return (KMEM_CBRC_LATER);
908 }
909
910 /*
911 * A dbuf may be removed (evicted) without an active dnode hold. In that
912 * case, the dbuf count is decremented under the handle lock before the
913 * dbuf's hold is released. This order ensures that if we count the hold
914 * after the dbuf is removed but before its hold is released, we will
915 * treat the unmatched hold as active and exit safely. If we count the
916 * hold before the dbuf is removed, the hold is discounted, and the
917 * removal is blocked until the move completes.
918 */
919 refcount = refcount_count(&odn->dn_holds);
920 ASSERT(refcount >= 0);
921 dbufs = odn->dn_dbufs_count;
922
923 /* We can't have more dbufs than dnode holds. */
924 ASSERT3U(dbufs, <=, refcount);
925 DTRACE_PROBE3(dnode__move, dnode_t *, odn, int64_t, refcount,
926 uint32_t, dbufs);
927
928 if (refcount > dbufs) {
929 rw_exit(&odn->dn_struct_rwlock);
930 zrl_exit(&odn->dn_handle->dnh_zrlock);
931 mutex_exit(&os->os_lock);
932 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_active);
933 return (KMEM_CBRC_LATER);
934 }
935
936 rw_exit(&odn->dn_struct_rwlock);
937
938 /*
939 * At this point we know that anyone with a hold on the dnode is not
940 * actively referencing it. The dnode is known and in a valid state to
941 * move. We're holding the locks needed to execute the critical section.
942 */
943 dnode_move_impl(odn, ndn);
944
945 list_link_replace(&odn->dn_link, &ndn->dn_link);
946 /* If the dnode was safe to move, the refcount cannot have changed. */
947 ASSERT(refcount == refcount_count(&ndn->dn_holds));
948 ASSERT(dbufs == ndn->dn_dbufs_count);
949 zrl_exit(&ndn->dn_handle->dnh_zrlock); /* handle has moved */
950 mutex_exit(&os->os_lock);
951
952 return (KMEM_CBRC_YES);
953 }
954 #endif /* _KERNEL */
955
956 void
957 dnode_special_close(dnode_handle_t *dnh)
958 {
959 dnode_t *dn = dnh->dnh_dnode;
960
961 /*
962 * Wait for final references to the dnode to clear. This can
963 * only happen if the arc is asyncronously evicting state that
964 * has a hold on this dnode while we are trying to evict this
965 * dnode.
966 */
967 while (refcount_count(&dn->dn_holds) > 0)
968 delay(1);
969 zrl_add(&dnh->dnh_zrlock);
970 dnode_destroy(dn); /* implicit zrl_remove() */
971 zrl_destroy(&dnh->dnh_zrlock);
972 dnh->dnh_dnode = NULL;
973 }
974
975 dnode_t *
976 dnode_special_open(objset_t *os, dnode_phys_t *dnp, uint64_t object,
977 dnode_handle_t *dnh)
978 {
979 dnode_t *dn = dnode_create(os, dnp, NULL, object, dnh);
980 dnh->dnh_dnode = dn;
981 zrl_init(&dnh->dnh_zrlock);
982 DNODE_VERIFY(dn);
983 return (dn);
984 }
985
986 static void
987 dnode_buf_pageout(dmu_buf_t *db, void *arg)
988 {
989 dnode_children_t *children_dnodes = arg;
990 int i;
991 int epb = db->db_size >> DNODE_SHIFT;
992
993 ASSERT(epb == children_dnodes->dnc_count);
994
995 for (i = 0; i < epb; i++) {
996 dnode_handle_t *dnh = &children_dnodes->dnc_children[i];
997 dnode_t *dn;
998
999 /*
1000 * The dnode handle lock guards against the dnode moving to
1001 * another valid address, so there is no need here to guard
1002 * against changes to or from NULL.
1003 */
1004 if (dnh->dnh_dnode == NULL) {
1005 zrl_destroy(&dnh->dnh_zrlock);
1006 continue;
1007 }
1008
1009 zrl_add(&dnh->dnh_zrlock);
1010 dn = dnh->dnh_dnode;
1011 /*
1012 * If there are holds on this dnode, then there should
1013 * be holds on the dnode's containing dbuf as well; thus
1014 * it wouldn't be eligible for eviction and this function
1015 * would not have been called.
1016 */
1017 ASSERT(refcount_is_zero(&dn->dn_holds));
1018 ASSERT(refcount_is_zero(&dn->dn_tx_holds));
1019
1020 dnode_destroy(dn); /* implicit zrl_remove() */
1021 zrl_destroy(&dnh->dnh_zrlock);
1022 dnh->dnh_dnode = NULL;
1023 }
1024 kmem_free(children_dnodes, sizeof (dnode_children_t) +
1025 epb * sizeof (dnode_handle_t));
1026 }
1027
1028 /*
1029 * errors:
1030 * EINVAL - invalid object number.
1031 * EIO - i/o error.
1032 * succeeds even for free dnodes.
1033 */
1034 int
1035 dnode_hold_impl(objset_t *os, uint64_t object, int flag,
1036 void *tag, dnode_t **dnp)
1037 {
1038 int epb, idx, err;
1039 int drop_struct_lock = FALSE;
1040 int type;
1041 uint64_t blk;
1042 dnode_t *mdn, *dn;
1043 dmu_buf_impl_t *db;
1044 dnode_children_t *children_dnodes;
1045 dnode_handle_t *dnh;
1046
1047 /*
1048 * If you are holding the spa config lock as writer, you shouldn't
1049 * be asking the DMU to do *anything* unless it's the root pool
1050 * which may require us to read from the root filesystem while
1051 * holding some (not all) of the locks as writer.
1052 */
1053 ASSERT(spa_config_held(os->os_spa, SCL_ALL, RW_WRITER) == 0 ||
1054 (spa_is_root(os->os_spa) &&
1055 spa_config_held(os->os_spa, SCL_STATE, RW_WRITER)));
1056
1057 if (object == DMU_USERUSED_OBJECT || object == DMU_GROUPUSED_OBJECT) {
1058 dn = (object == DMU_USERUSED_OBJECT) ?
1059 DMU_USERUSED_DNODE(os) : DMU_GROUPUSED_DNODE(os);
1060 if (dn == NULL)
1061 return (SET_ERROR(ENOENT));
1062 type = dn->dn_type;
1063 if ((flag & DNODE_MUST_BE_ALLOCATED) && type == DMU_OT_NONE)
1064 return (SET_ERROR(ENOENT));
1065 if ((flag & DNODE_MUST_BE_FREE) && type != DMU_OT_NONE)
1066 return (SET_ERROR(EEXIST));
1067 DNODE_VERIFY(dn);
1068 (void) refcount_add(&dn->dn_holds, tag);
1069 *dnp = dn;
1070 return (0);
1071 }
1072
1073 if (object == 0 || object >= DN_MAX_OBJECT)
1074 return (SET_ERROR(EINVAL));
1075
1076 mdn = DMU_META_DNODE(os);
1077 ASSERT(mdn->dn_object == DMU_META_DNODE_OBJECT);
1078
1079 DNODE_VERIFY(mdn);
1080
1081 if (!RW_WRITE_HELD(&mdn->dn_struct_rwlock)) {
1082 rw_enter(&mdn->dn_struct_rwlock, RW_READER);
1083 drop_struct_lock = TRUE;
1084 }
1085
1086 blk = dbuf_whichblock(mdn, object * sizeof (dnode_phys_t));
1087
1088 db = dbuf_hold(mdn, blk, FTAG);
1089 if (drop_struct_lock)
1090 rw_exit(&mdn->dn_struct_rwlock);
1091 if (db == NULL)
1092 return (SET_ERROR(EIO));
1093 err = dbuf_read(db, NULL, DB_RF_CANFAIL);
1094 if (err) {
1095 dbuf_rele(db, FTAG);
1096 return (err);
1097 }
1098
1099 ASSERT3U(db->db.db_size, >=, 1<<DNODE_SHIFT);
1100 epb = db->db.db_size >> DNODE_SHIFT;
1101
1102 idx = object & (epb-1);
1103
1104 ASSERT(DB_DNODE(db)->dn_type == DMU_OT_DNODE);
1105 children_dnodes = dmu_buf_get_user(&db->db);
1106 if (children_dnodes == NULL) {
1107 int i;
1108 dnode_children_t *winner;
1109 children_dnodes = kmem_alloc(sizeof (dnode_children_t) +
1110 epb * sizeof (dnode_handle_t), KM_SLEEP);
1111 children_dnodes->dnc_count = epb;
1112 dnh = &children_dnodes->dnc_children[0];
1113 for (i = 0; i < epb; i++) {
1114 zrl_init(&dnh[i].dnh_zrlock);
1115 dnh[i].dnh_dnode = NULL;
1116 }
1117 if (winner = dmu_buf_set_user(&db->db, children_dnodes,
1118 dnode_buf_pageout)) {
1119
1120 for (i = 0; i < epb; i++) {
1121 zrl_destroy(&dnh[i].dnh_zrlock);
1122 }
1123
1124 kmem_free(children_dnodes, sizeof (dnode_children_t) +
1125 epb * sizeof (dnode_handle_t));
1126 children_dnodes = winner;
1127 }
1128 }
1129 ASSERT(children_dnodes->dnc_count == epb);
1130
1131 dnh = &children_dnodes->dnc_children[idx];
1132 zrl_add(&dnh->dnh_zrlock);
1133 if ((dn = dnh->dnh_dnode) == NULL) {
1134 dnode_phys_t *phys = (dnode_phys_t *)db->db.db_data+idx;
1135 dnode_t *winner;
1136
1137 dn = dnode_create(os, phys, db, object, dnh);
1138 winner = atomic_cas_ptr(&dnh->dnh_dnode, NULL, dn);
1139 if (winner != NULL) {
1140 zrl_add(&dnh->dnh_zrlock);
1141 dnode_destroy(dn); /* implicit zrl_remove() */
1142 dn = winner;
1143 }
1144 }
1145
1146 mutex_enter(&dn->dn_mtx);
1147 type = dn->dn_type;
1148 if (dn->dn_free_txg ||
1149 ((flag & DNODE_MUST_BE_ALLOCATED) && type == DMU_OT_NONE) ||
1150 ((flag & DNODE_MUST_BE_FREE) &&
1151 (type != DMU_OT_NONE || !refcount_is_zero(&dn->dn_holds)))) {
1152 mutex_exit(&dn->dn_mtx);
1153 zrl_remove(&dnh->dnh_zrlock);
1154 dbuf_rele(db, FTAG);
1155 return (type == DMU_OT_NONE ? ENOENT : EEXIST);
1156 }
1157 mutex_exit(&dn->dn_mtx);
1158
1159 if (refcount_add(&dn->dn_holds, tag) == 1)
1160 dbuf_add_ref(db, dnh);
1161 /* Now we can rely on the hold to prevent the dnode from moving. */
1162 zrl_remove(&dnh->dnh_zrlock);
1163
1164 DNODE_VERIFY(dn);
1165 ASSERT3P(dn->dn_dbuf, ==, db);
1166 ASSERT3U(dn->dn_object, ==, object);
1167 dbuf_rele(db, FTAG);
1168
1169 *dnp = dn;
1170 return (0);
1171 }
1172
1173 /*
1174 * Return held dnode if the object is allocated, NULL if not.
1175 */
1176 int
1177 dnode_hold(objset_t *os, uint64_t object, void *tag, dnode_t **dnp)
1178 {
1179 return (dnode_hold_impl(os, object, DNODE_MUST_BE_ALLOCATED, tag, dnp));
1180 }
1181
1182 /*
1183 * Can only add a reference if there is already at least one
1184 * reference on the dnode. Returns FALSE if unable to add a
1185 * new reference.
1186 */
1187 boolean_t
1188 dnode_add_ref(dnode_t *dn, void *tag)
1189 {
1190 mutex_enter(&dn->dn_mtx);
1191 if (refcount_is_zero(&dn->dn_holds)) {
1192 mutex_exit(&dn->dn_mtx);
1193 return (FALSE);
1194 }
1195 VERIFY(1 < refcount_add(&dn->dn_holds, tag));
1196 mutex_exit(&dn->dn_mtx);
1197 return (TRUE);
1198 }
1199
1200 void
1201 dnode_rele(dnode_t *dn, void *tag)
1202 {
1203 uint64_t refs;
1204 /* Get while the hold prevents the dnode from moving. */
1205 dmu_buf_impl_t *db = dn->dn_dbuf;
1206 dnode_handle_t *dnh = dn->dn_handle;
1207
1208 mutex_enter(&dn->dn_mtx);
1209 refs = refcount_remove(&dn->dn_holds, tag);
1210 mutex_exit(&dn->dn_mtx);
1211
1212 /*
1213 * It's unsafe to release the last hold on a dnode by dnode_rele() or
1214 * indirectly by dbuf_rele() while relying on the dnode handle to
1215 * prevent the dnode from moving, since releasing the last hold could
1216 * result in the dnode's parent dbuf evicting its dnode handles. For
1217 * that reason anyone calling dnode_rele() or dbuf_rele() without some
1218 * other direct or indirect hold on the dnode must first drop the dnode
1219 * handle.
1220 */
1221 ASSERT(refs > 0 || dnh->dnh_zrlock.zr_owner != curthread);
1222
1223 /* NOTE: the DNODE_DNODE does not have a dn_dbuf */
1224 if (refs == 0 && db != NULL) {
1225 /*
1226 * Another thread could add a hold to the dnode handle in
1227 * dnode_hold_impl() while holding the parent dbuf. Since the
1228 * hold on the parent dbuf prevents the handle from being
1229 * destroyed, the hold on the handle is OK. We can't yet assert
1230 * that the handle has zero references, but that will be
1231 * asserted anyway when the handle gets destroyed.
1232 */
1233 dbuf_rele(db, dnh);
1234 }
1235 }
1236
1237 void
1238 dnode_setdirty(dnode_t *dn, dmu_tx_t *tx)
1239 {
1240 objset_t *os = dn->dn_objset;
1241 uint64_t txg = tx->tx_txg;
1242
1243 if (DMU_OBJECT_IS_SPECIAL(dn->dn_object)) {
1244 dsl_dataset_dirty(os->os_dsl_dataset, tx);
1245 return;
1246 }
1247
1248 DNODE_VERIFY(dn);
1249
1250 #ifdef ZFS_DEBUG
1251 mutex_enter(&dn->dn_mtx);
1252 ASSERT(dn->dn_phys->dn_type || dn->dn_allocated_txg);
1253 ASSERT(dn->dn_free_txg == 0 || dn->dn_free_txg >= txg);
1254 mutex_exit(&dn->dn_mtx);
1255 #endif
1256
1257 /*
1258 * Determine old uid/gid when necessary
1259 */
1260 dmu_objset_userquota_get_ids(dn, B_TRUE, tx);
1261
1262 mutex_enter(&os->os_lock);
1263
1264 /*
1265 * If we are already marked dirty, we're done.
1266 */
1267 if (list_link_active(&dn->dn_dirty_link[txg & TXG_MASK])) {
1268 mutex_exit(&os->os_lock);
1269 return;
1270 }
1271
1272 ASSERT(!refcount_is_zero(&dn->dn_holds) ||
1273 !avl_is_empty(&dn->dn_dbufs));
1274 ASSERT(dn->dn_datablksz != 0);
1275 ASSERT0(dn->dn_next_bonuslen[txg&TXG_MASK]);
1276 ASSERT0(dn->dn_next_blksz[txg&TXG_MASK]);
1277 ASSERT0(dn->dn_next_bonustype[txg&TXG_MASK]);
1278
1279 dprintf_ds(os->os_dsl_dataset, "obj=%llu txg=%llu\n",
1280 dn->dn_object, txg);
1281
1282 if (dn->dn_free_txg > 0 && dn->dn_free_txg <= txg) {
1283 list_insert_tail(&os->os_free_dnodes[txg&TXG_MASK], dn);
1284 } else {
1285 list_insert_tail(&os->os_dirty_dnodes[txg&TXG_MASK], dn);
1286 }
1287
1288 mutex_exit(&os->os_lock);
1289
1290 /*
1291 * The dnode maintains a hold on its containing dbuf as
1292 * long as there are holds on it. Each instantiated child
1293 * dbuf maintains a hold on the dnode. When the last child
1294 * drops its hold, the dnode will drop its hold on the
1295 * containing dbuf. We add a "dirty hold" here so that the
1296 * dnode will hang around after we finish processing its
1297 * children.
1298 */
1299 VERIFY(dnode_add_ref(dn, (void *)(uintptr_t)tx->tx_txg));
1300
1301 (void) dbuf_dirty(dn->dn_dbuf, tx);
1302
1303 dsl_dataset_dirty(os->os_dsl_dataset, tx);
1304 }
1305
1306 void
1307 dnode_free(dnode_t *dn, dmu_tx_t *tx)
1308 {
1309 int txgoff = tx->tx_txg & TXG_MASK;
1310
1311 dprintf("dn=%p txg=%llu\n", dn, tx->tx_txg);
1312
1313 /* we should be the only holder... hopefully */
1314 /* ASSERT3U(refcount_count(&dn->dn_holds), ==, 1); */
1315
1316 mutex_enter(&dn->dn_mtx);
1317 if (dn->dn_type == DMU_OT_NONE || dn->dn_free_txg) {
1318 mutex_exit(&dn->dn_mtx);
1319 return;
1320 }
1321 dn->dn_free_txg = tx->tx_txg;
1322 mutex_exit(&dn->dn_mtx);
1323
1324 /*
1325 * If the dnode is already dirty, it needs to be moved from
1326 * the dirty list to the free list.
1327 */
1328 mutex_enter(&dn->dn_objset->os_lock);
1329 if (list_link_active(&dn->dn_dirty_link[txgoff])) {
1330 list_remove(&dn->dn_objset->os_dirty_dnodes[txgoff], dn);
1331 list_insert_tail(&dn->dn_objset->os_free_dnodes[txgoff], dn);
1332 mutex_exit(&dn->dn_objset->os_lock);
1333 } else {
1334 mutex_exit(&dn->dn_objset->os_lock);
1335 dnode_setdirty(dn, tx);
1336 }
1337 }
1338
1339 /*
1340 * Try to change the block size for the indicated dnode. This can only
1341 * succeed if there are no blocks allocated or dirty beyond first block
1342 */
1343 int
1344 dnode_set_blksz(dnode_t *dn, uint64_t size, int ibs, dmu_tx_t *tx)
1345 {
1346 dmu_buf_impl_t *db;
1347 int err;
1348
1349 ASSERT3U(size, <=, spa_maxblocksize(dmu_objset_spa(dn->dn_objset)));
1350 if (size == 0)
1351 size = SPA_MINBLOCKSIZE;
1352 else
1353 size = P2ROUNDUP(size, SPA_MINBLOCKSIZE);
1354
1355 if (ibs == dn->dn_indblkshift)
1356 ibs = 0;
1357
1358 if (size >> SPA_MINBLOCKSHIFT == dn->dn_datablkszsec && ibs == 0)
1359 return (0);
1360
1361 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
1362
1363 /* Check for any allocated blocks beyond the first */
1364 if (dn->dn_maxblkid != 0)
1365 goto fail;
1366
1367 mutex_enter(&dn->dn_dbufs_mtx);
1368 for (db = avl_first(&dn->dn_dbufs); db != NULL;
1369 db = AVL_NEXT(&dn->dn_dbufs, db)) {
1370 if (db->db_blkid != 0 && db->db_blkid != DMU_BONUS_BLKID &&
1371 db->db_blkid != DMU_SPILL_BLKID) {
1372 mutex_exit(&dn->dn_dbufs_mtx);
1373 goto fail;
1374 }
1375 }
1376 mutex_exit(&dn->dn_dbufs_mtx);
1377
1378 if (ibs && dn->dn_nlevels != 1)
1379 goto fail;
1380
1381 /* resize the old block */
1382 err = dbuf_hold_impl(dn, 0, 0, TRUE, FTAG, &db);
1383 if (err == 0)
1384 dbuf_new_size(db, size, tx);
1385 else if (err != ENOENT)
1386 goto fail;
1387
1388 dnode_setdblksz(dn, size);
1389 dnode_setdirty(dn, tx);
1390 dn->dn_next_blksz[tx->tx_txg&TXG_MASK] = size;
1391 if (ibs) {
1392 dn->dn_indblkshift = ibs;
1393 dn->dn_next_indblkshift[tx->tx_txg&TXG_MASK] = ibs;
1394 }
1395 /* rele after we have fixed the blocksize in the dnode */
1396 if (db)
1397 dbuf_rele(db, FTAG);
1398
1399 rw_exit(&dn->dn_struct_rwlock);
1400 return (0);
1401
1402 fail:
1403 rw_exit(&dn->dn_struct_rwlock);
1404 return (SET_ERROR(ENOTSUP));
1405 }
1406
1407 /* read-holding callers must not rely on the lock being continuously held */
1408 void
1409 dnode_new_blkid(dnode_t *dn, uint64_t blkid, dmu_tx_t *tx, boolean_t have_read)
1410 {
1411 uint64_t txgoff = tx->tx_txg & TXG_MASK;
1412 int epbs, new_nlevels;
1413 uint64_t sz;
1414
1415 ASSERT(blkid != DMU_BONUS_BLKID);
1416
1417 ASSERT(have_read ?
1418 RW_READ_HELD(&dn->dn_struct_rwlock) :
1419 RW_WRITE_HELD(&dn->dn_struct_rwlock));
1420
1421 /*
1422 * if we have a read-lock, check to see if we need to do any work
1423 * before upgrading to a write-lock.
1424 */
1425 if (have_read) {
1426 if (blkid <= dn->dn_maxblkid)
1427 return;
1428
1429 if (!rw_tryupgrade(&dn->dn_struct_rwlock)) {
1430 rw_exit(&dn->dn_struct_rwlock);
1431 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
1432 }
1433 }
1434
1435 if (blkid <= dn->dn_maxblkid)
1436 goto out;
1437
1438 dn->dn_maxblkid = blkid;
1439
1440 /*
1441 * Compute the number of levels necessary to support the new maxblkid.
1442 */
1443 new_nlevels = 1;
1444 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT;
1445 for (sz = dn->dn_nblkptr;
1446 sz <= blkid && sz >= dn->dn_nblkptr; sz <<= epbs)
1447 new_nlevels++;
1448
1449 if (new_nlevels > dn->dn_nlevels) {
1450 int old_nlevels = dn->dn_nlevels;
1451 dmu_buf_impl_t *db;
1452 list_t *list;
1453 dbuf_dirty_record_t *new, *dr, *dr_next;
1454
1455 dn->dn_nlevels = new_nlevels;
1456
1457 ASSERT3U(new_nlevels, >, dn->dn_next_nlevels[txgoff]);
1458 dn->dn_next_nlevels[txgoff] = new_nlevels;
1459
1460 /* dirty the left indirects */
1461 db = dbuf_hold_level(dn, old_nlevels, 0, FTAG);
1462 ASSERT(db != NULL);
1463 new = dbuf_dirty(db, tx);
1464 dbuf_rele(db, FTAG);
1465
1466 /* transfer the dirty records to the new indirect */
1467 mutex_enter(&dn->dn_mtx);
1468 mutex_enter(&new->dt.di.dr_mtx);
1469 list = &dn->dn_dirty_records[txgoff];
1470 for (dr = list_head(list); dr; dr = dr_next) {
1471 dr_next = list_next(&dn->dn_dirty_records[txgoff], dr);
1472 if (dr->dr_dbuf->db_level != new_nlevels-1 &&
1473 dr->dr_dbuf->db_blkid != DMU_BONUS_BLKID &&
1474 dr->dr_dbuf->db_blkid != DMU_SPILL_BLKID) {
1475 ASSERT(dr->dr_dbuf->db_level == old_nlevels-1);
1476 list_remove(&dn->dn_dirty_records[txgoff], dr);
1477 list_insert_tail(&new->dt.di.dr_children, dr);
1478 dr->dr_parent = new;
1479 }
1480 }
1481 mutex_exit(&new->dt.di.dr_mtx);
1482 mutex_exit(&dn->dn_mtx);
1483 }
1484
1485 out:
1486 if (have_read)
1487 rw_downgrade(&dn->dn_struct_rwlock);
1488 }
1489
1490 void
1491 dnode_free_range(dnode_t *dn, uint64_t off, uint64_t len, dmu_tx_t *tx)
1492 {
1493 dmu_buf_impl_t *db;
1494 uint64_t blkoff, blkid, nblks;
1495 int blksz, blkshift, head, tail;
1496 int trunc = FALSE;
1497 int epbs;
1498
1499 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
1500 blksz = dn->dn_datablksz;
1501 blkshift = dn->dn_datablkshift;
1502 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT;
1503
1504 if (len == DMU_OBJECT_END) {
1505 len = UINT64_MAX - off;
1506 trunc = TRUE;
1507 }
1508
1509 /*
1510 * First, block align the region to free:
1511 */
1512 if (ISP2(blksz)) {
1513 head = P2NPHASE(off, blksz);
1514 blkoff = P2PHASE(off, blksz);
1515 if ((off >> blkshift) > dn->dn_maxblkid)
1516 goto out;
1517 } else {
1518 ASSERT(dn->dn_maxblkid == 0);
1519 if (off == 0 && len >= blksz) {
1520 /*
1521 * Freeing the whole block; fast-track this request.
1522 * Note that we won't dirty any indirect blocks,
1523 * which is fine because we will be freeing the entire
1524 * file and thus all indirect blocks will be freed
1525 * by free_children().
1526 */
1527 blkid = 0;
1528 nblks = 1;
1529 goto done;
1530 } else if (off >= blksz) {
1531 /* Freeing past end-of-data */
1532 goto out;
1533 } else {
1534 /* Freeing part of the block. */
1535 head = blksz - off;
1536 ASSERT3U(head, >, 0);
1537 }
1538 blkoff = off;
1539 }
1540 /* zero out any partial block data at the start of the range */
1541 if (head) {
1542 ASSERT3U(blkoff + head, ==, blksz);
1543 if (len < head)
1544 head = len;
1545 if (dbuf_hold_impl(dn, 0, dbuf_whichblock(dn, off), TRUE,
1546 FTAG, &db) == 0) {
1547 caddr_t data;
1548
1549 /* don't dirty if it isn't on disk and isn't dirty */
1550 if (db->db_last_dirty ||
1551 (db->db_blkptr && !BP_IS_HOLE(db->db_blkptr))) {
1552 rw_exit(&dn->dn_struct_rwlock);
1553 dmu_buf_will_dirty(&db->db, tx);
1554 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
1555 data = db->db.db_data;
1556 bzero(data + blkoff, head);
1557 }
1558 dbuf_rele(db, FTAG);
1559 }
1560 off += head;
1561 len -= head;
1562 }
1563
1564 /* If the range was less than one block, we're done */
1565 if (len == 0)
1566 goto out;
1567
1568 /* If the remaining range is past end of file, we're done */
1569 if ((off >> blkshift) > dn->dn_maxblkid)
1570 goto out;
1571
1572 ASSERT(ISP2(blksz));
1573 if (trunc)
1574 tail = 0;
1575 else
1576 tail = P2PHASE(len, blksz);
1577
1578 ASSERT0(P2PHASE(off, blksz));
1579 /* zero out any partial block data at the end of the range */
1580 if (tail) {
1581 if (len < tail)
1582 tail = len;
1583 if (dbuf_hold_impl(dn, 0, dbuf_whichblock(dn, off+len),
1584 TRUE, FTAG, &db) == 0) {
1585 /* don't dirty if not on disk and not dirty */
1586 if (db->db_last_dirty ||
1587 (db->db_blkptr && !BP_IS_HOLE(db->db_blkptr))) {
1588 rw_exit(&dn->dn_struct_rwlock);
1589 dmu_buf_will_dirty(&db->db, tx);
1590 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
1591 bzero(db->db.db_data, tail);
1592 }
1593 dbuf_rele(db, FTAG);
1594 }
1595 len -= tail;
1596 }
1597
1598 /* If the range did not include a full block, we are done */
1599 if (len == 0)
1600 goto out;
1601
1602 ASSERT(IS_P2ALIGNED(off, blksz));
1603 ASSERT(trunc || IS_P2ALIGNED(len, blksz));
1604 blkid = off >> blkshift;
1605 nblks = len >> blkshift;
1606 if (trunc)
1607 nblks += 1;
1608
1609 /*
1610 * Dirty the first and last indirect blocks, as they (and/or their
1611 * parents) will need to be written out if they were only
1612 * partially freed. Interior indirect blocks will be themselves freed,
1613 * by free_children(), so they need not be dirtied. Note that these
1614 * interior blocks have already been prefetched by dmu_tx_hold_free().
1615 */
1616 if (dn->dn_nlevels > 1) {
1617 uint64_t first, last;
1618
1619 first = blkid >> epbs;
1620 if (db = dbuf_hold_level(dn, 1, first, FTAG)) {
1621 dmu_buf_will_dirty(&db->db, tx);
1622 dbuf_rele(db, FTAG);
1623 }
1624 if (trunc)
1625 last = dn->dn_maxblkid >> epbs;
1626 else
1627 last = (blkid + nblks - 1) >> epbs;
1628 if (last > first && (db = dbuf_hold_level(dn, 1, last, FTAG))) {
1629 dmu_buf_will_dirty(&db->db, tx);
1630 dbuf_rele(db, FTAG);
1631 }
1632 }
1633
1634 done:
1635 /*
1636 * Add this range to the dnode range list.
1637 * We will finish up this free operation in the syncing phase.
1638 */
1639 mutex_enter(&dn->dn_mtx);
1640 int txgoff = tx->tx_txg & TXG_MASK;
1641 if (dn->dn_free_ranges[txgoff] == NULL) {
1642 dn->dn_free_ranges[txgoff] =
1643 range_tree_create(NULL, NULL, &dn->dn_mtx);
1644 }
1645 range_tree_clear(dn->dn_free_ranges[txgoff], blkid, nblks);
1646 range_tree_add(dn->dn_free_ranges[txgoff], blkid, nblks);
1647 dprintf_dnode(dn, "blkid=%llu nblks=%llu txg=%llu\n",
1648 blkid, nblks, tx->tx_txg);
1649 mutex_exit(&dn->dn_mtx);
1650
1651 dbuf_free_range(dn, blkid, blkid + nblks - 1, tx);
1652 dnode_setdirty(dn, tx);
1653 out:
1654
1655 rw_exit(&dn->dn_struct_rwlock);
1656 }
1657
1658 static boolean_t
1659 dnode_spill_freed(dnode_t *dn)
1660 {
1661 int i;
1662
1663 mutex_enter(&dn->dn_mtx);
1664 for (i = 0; i < TXG_SIZE; i++) {
1665 if (dn->dn_rm_spillblk[i] == DN_KILL_SPILLBLK)
1666 break;
1667 }
1668 mutex_exit(&dn->dn_mtx);
1669 return (i < TXG_SIZE);
1670 }
1671
1672 /* return TRUE if this blkid was freed in a recent txg, or FALSE if it wasn't */
1673 uint64_t
1674 dnode_block_freed(dnode_t *dn, uint64_t blkid)
1675 {
1676 void *dp = spa_get_dsl(dn->dn_objset->os_spa);
1677 int i;
1678
1679 if (blkid == DMU_BONUS_BLKID)
1680 return (FALSE);
1681
1682 /*
1683 * If we're in the process of opening the pool, dp will not be
1684 * set yet, but there shouldn't be anything dirty.
1685 */
1686 if (dp == NULL)
1687 return (FALSE);
1688
1689 if (dn->dn_free_txg)
1690 return (TRUE);
1691
1692 if (blkid == DMU_SPILL_BLKID)
1693 return (dnode_spill_freed(dn));
1694
1695 mutex_enter(&dn->dn_mtx);
1696 for (i = 0; i < TXG_SIZE; i++) {
1697 if (dn->dn_free_ranges[i] != NULL &&
1698 range_tree_contains(dn->dn_free_ranges[i], blkid, 1))
1699 break;
1700 }
1701 mutex_exit(&dn->dn_mtx);
1702 return (i < TXG_SIZE);
1703 }
1704
1705 /* call from syncing context when we actually write/free space for this dnode */
1706 void
1707 dnode_diduse_space(dnode_t *dn, int64_t delta)
1708 {
1709 uint64_t space;
1710 dprintf_dnode(dn, "dn=%p dnp=%p used=%llu delta=%lld\n",
1711 dn, dn->dn_phys,
1712 (u_longlong_t)dn->dn_phys->dn_used,
1713 (longlong_t)delta);
1714
1715 mutex_enter(&dn->dn_mtx);
1716 space = DN_USED_BYTES(dn->dn_phys);
1717 if (delta > 0) {
1718 ASSERT3U(space + delta, >=, space); /* no overflow */
1719 } else {
1720 ASSERT3U(space, >=, -delta); /* no underflow */
1721 }
1722 space += delta;
1723 if (spa_version(dn->dn_objset->os_spa) < SPA_VERSION_DNODE_BYTES) {
1724 ASSERT((dn->dn_phys->dn_flags & DNODE_FLAG_USED_BYTES) == 0);
1725 ASSERT0(P2PHASE(space, 1<<DEV_BSHIFT));
1726 dn->dn_phys->dn_used = space >> DEV_BSHIFT;
1727 } else {
1728 dn->dn_phys->dn_used = space;
1729 dn->dn_phys->dn_flags |= DNODE_FLAG_USED_BYTES;
1730 }
1731 mutex_exit(&dn->dn_mtx);
1732 }
1733
1734 /*
1735 * Call when we think we're going to write/free space in open context to track
1736 * the amount of memory in use by the currently open txg.
1737 */
1738 void
1739 dnode_willuse_space(dnode_t *dn, int64_t space, dmu_tx_t *tx)
1740 {
1741 objset_t *os = dn->dn_objset;
1742 dsl_dataset_t *ds = os->os_dsl_dataset;
1743 int64_t aspace = spa_get_asize(os->os_spa, space);
1744
1745 if (ds != NULL) {
1746 dsl_dir_willuse_space(ds->ds_dir, aspace, tx);
1747 dsl_pool_dirty_space(dmu_tx_pool(tx), space, tx);
1748 }
1749
1750 dmu_tx_willuse_space(tx, aspace);
1751 }
1752
1753 /*
1754 * Scans a block at the indicated "level" looking for a hole or data,
1755 * depending on 'flags'.
1756 *
1757 * If level > 0, then we are scanning an indirect block looking at its
1758 * pointers. If level == 0, then we are looking at a block of dnodes.
1759 *
1760 * If we don't find what we are looking for in the block, we return ESRCH.
1761 * Otherwise, return with *offset pointing to the beginning (if searching
1762 * forwards) or end (if searching backwards) of the range covered by the
1763 * block pointer we matched on (or dnode).
1764 *
1765 * The basic search algorithm used below by dnode_next_offset() is to
1766 * use this function to search up the block tree (widen the search) until
1767 * we find something (i.e., we don't return ESRCH) and then search back
1768 * down the tree (narrow the search) until we reach our original search
1769 * level.
1770 */
1771 static int
1772 dnode_next_offset_level(dnode_t *dn, int flags, uint64_t *offset,
1773 int lvl, uint64_t blkfill, uint64_t txg)
1774 {
1775 dmu_buf_impl_t *db = NULL;
1776 void *data = NULL;
1777 uint64_t epbs = dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT;
1778 uint64_t epb = 1ULL << epbs;
1779 uint64_t minfill, maxfill;
1780 boolean_t hole;
1781 int i, inc, error, span;
1782
1783 dprintf("probing object %llu offset %llx level %d of %u\n",
1784 dn->dn_object, *offset, lvl, dn->dn_phys->dn_nlevels);
1785
1786 hole = ((flags & DNODE_FIND_HOLE) != 0);
1787 inc = (flags & DNODE_FIND_BACKWARDS) ? -1 : 1;
1788 ASSERT(txg == 0 || !hole);
1789
1790 if (lvl == dn->dn_phys->dn_nlevels) {
1791 error = 0;
1792 epb = dn->dn_phys->dn_nblkptr;
1793 data = dn->dn_phys->dn_blkptr;
1794 } else {
1795 uint64_t blkid = dbuf_whichblock(dn, *offset) >> (epbs * lvl);
1796 error = dbuf_hold_impl(dn, lvl, blkid, TRUE, FTAG, &db);
1797 if (error) {
1798 if (error != ENOENT)
1799 return (error);
1800 if (hole)
1801 return (0);
1802 /*
1803 * This can only happen when we are searching up
1804 * the block tree for data. We don't really need to
1805 * adjust the offset, as we will just end up looking
1806 * at the pointer to this block in its parent, and its
1807 * going to be unallocated, so we will skip over it.
1808 */
1809 return (SET_ERROR(ESRCH));
1810 }
1811 error = dbuf_read(db, NULL, DB_RF_CANFAIL | DB_RF_HAVESTRUCT);
1812 if (error) {
1813 dbuf_rele(db, FTAG);
1814 return (error);
1815 }
1816 data = db->db.db_data;
1817 }
1818
1819
1820 if (db != NULL && txg != 0 && (db->db_blkptr == NULL ||
1821 db->db_blkptr->blk_birth <= txg ||
1822 BP_IS_HOLE(db->db_blkptr))) {
1823 /*
1824 * This can only happen when we are searching up the tree
1825 * and these conditions mean that we need to keep climbing.
1826 */
1827 error = SET_ERROR(ESRCH);
1828 } else if (lvl == 0) {
1829 dnode_phys_t *dnp = data;
1830 span = DNODE_SHIFT;
1831 ASSERT(dn->dn_type == DMU_OT_DNODE);
1832
1833 for (i = (*offset >> span) & (blkfill - 1);
1834 i >= 0 && i < blkfill; i += inc) {
1835 if ((dnp[i].dn_type == DMU_OT_NONE) == hole)
1836 break;
1837 *offset += (1ULL << span) * inc;
1838 }
1839 if (i < 0 || i == blkfill)
1840 error = SET_ERROR(ESRCH);
1841 } else {
1842 blkptr_t *bp = data;
1843 uint64_t start = *offset;
1844 span = (lvl - 1) * epbs + dn->dn_datablkshift;
1845 minfill = 0;
1846 maxfill = blkfill << ((lvl - 1) * epbs);
1847
1848 if (hole)
1849 maxfill--;
1850 else
1851 minfill++;
1852
1853 *offset = *offset >> span;
1854 for (i = BF64_GET(*offset, 0, epbs);
1855 i >= 0 && i < epb; i += inc) {
1856 if (BP_GET_FILL(&bp[i]) >= minfill &&
1857 BP_GET_FILL(&bp[i]) <= maxfill &&
1858 (hole || bp[i].blk_birth > txg))
1859 break;
1860 if (inc > 0 || *offset > 0)
1861 *offset += inc;
1862 }
1863 *offset = *offset << span;
1864 if (inc < 0) {
1865 /* traversing backwards; position offset at the end */
1866 ASSERT3U(*offset, <=, start);
1867 *offset = MIN(*offset + (1ULL << span) - 1, start);
1868 } else if (*offset < start) {
1869 *offset = start;
1870 }
1871 if (i < 0 || i >= epb)
1872 error = SET_ERROR(ESRCH);
1873 }
1874
1875 if (db)
1876 dbuf_rele(db, FTAG);
1877
1878 return (error);
1879 }
1880
1881 /*
1882 * Find the next hole, data, or sparse region at or after *offset.
1883 * The value 'blkfill' tells us how many items we expect to find
1884 * in an L0 data block; this value is 1 for normal objects,
1885 * DNODES_PER_BLOCK for the meta dnode, and some fraction of
1886 * DNODES_PER_BLOCK when searching for sparse regions thereof.
1887 *
1888 * Examples:
1889 *
1890 * dnode_next_offset(dn, flags, offset, 1, 1, 0);
1891 * Finds the next/previous hole/data in a file.
1892 * Used in dmu_offset_next().
1893 *
1894 * dnode_next_offset(mdn, flags, offset, 0, DNODES_PER_BLOCK, txg);
1895 * Finds the next free/allocated dnode an objset's meta-dnode.
1896 * Only finds objects that have new contents since txg (ie.
1897 * bonus buffer changes and content removal are ignored).
1898 * Used in dmu_object_next().
1899 *
1900 * dnode_next_offset(mdn, DNODE_FIND_HOLE, offset, 2, DNODES_PER_BLOCK >> 2, 0);
1901 * Finds the next L2 meta-dnode bp that's at most 1/4 full.
1902 * Used in dmu_object_alloc().
1903 */
1904 int
1905 dnode_next_offset(dnode_t *dn, int flags, uint64_t *offset,
1906 int minlvl, uint64_t blkfill, uint64_t txg)
1907 {
1908 uint64_t initial_offset = *offset;
1909 int lvl, maxlvl;
1910 int error = 0;
1911
1912 if (!(flags & DNODE_FIND_HAVELOCK))
1913 rw_enter(&dn->dn_struct_rwlock, RW_READER);
1914
1915 if (dn->dn_phys->dn_nlevels == 0) {
1916 error = SET_ERROR(ESRCH);
1917 goto out;
1918 }
1919
1920 if (dn->dn_datablkshift == 0) {
1921 if (*offset < dn->dn_datablksz) {
1922 if (flags & DNODE_FIND_HOLE)
1923 *offset = dn->dn_datablksz;
1924 } else {
1925 error = SET_ERROR(ESRCH);
1926 }
1927 goto out;
1928 }
1929
1930 maxlvl = dn->dn_phys->dn_nlevels;
1931
1932 for (lvl = minlvl; lvl <= maxlvl; lvl++) {
1933 error = dnode_next_offset_level(dn,
1934 flags, offset, lvl, blkfill, txg);
1935 if (error != ESRCH)
1936 break;
1937 }
1938
1939 while (error == 0 && --lvl >= minlvl) {
1940 error = dnode_next_offset_level(dn,
1941 flags, offset, lvl, blkfill, txg);
1942 }
1943
1944 /*
1945 * There's always a "virtual hole" at the end of the object, even
1946 * if all BP's which physically exist are non-holes.
1947 */
1948 if ((flags & DNODE_FIND_HOLE) && error == ESRCH && txg == 0 &&
1949 minlvl == 1 && blkfill == 1 && !(flags & DNODE_FIND_BACKWARDS)) {
1950 error = 0;
1951 }
1952
1953 if (error == 0 && (flags & DNODE_FIND_BACKWARDS ?
1954 initial_offset < *offset : initial_offset > *offset))
1955 error = SET_ERROR(ESRCH);
1956 out:
1957 if (!(flags & DNODE_FIND_HAVELOCK))
1958 rw_exit(&dn->dn_struct_rwlock);
1959
1960 return (error);
1961 }