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 < d2->db_state) {
83 return (-1);
84 }
85 if (d1->db_state > d2->db_state) {
86 return (1);
87 }
88
89 ASSERT3S(d1->db_state, !=, DB_SEARCH);
90 ASSERT3S(d2->db_state, !=, DB_SEARCH);
91
92 if ((uintptr_t)d1 < (uintptr_t)d2) {
93 return (-1);
94 }
95 if ((uintptr_t)d1 > (uintptr_t)d2) {
96 return (1);
97 }
98 return (0);
99 }
100
101 /* ARGSUSED */
102 static int
103 dnode_cons(void *arg, void *unused, int kmflag)
104 {
105 dnode_t *dn = arg;
106 int i;
107
108 rw_init(&dn->dn_struct_rwlock, NULL, RW_DEFAULT, NULL);
109 mutex_init(&dn->dn_mtx, NULL, MUTEX_DEFAULT, NULL);
110 mutex_init(&dn->dn_dbufs_mtx, NULL, MUTEX_DEFAULT, NULL);
111 cv_init(&dn->dn_notxholds, NULL, CV_DEFAULT, NULL);
112
113 /*
114 * Every dbuf has a reference, and dropping a tracked reference is
115 * O(number of references), so don't track dn_holds.
116 */
117 refcount_create_untracked(&dn->dn_holds);
118 refcount_create(&dn->dn_tx_holds);
119 list_link_init(&dn->dn_link);
120
121 bzero(&dn->dn_next_nblkptr[0], sizeof (dn->dn_next_nblkptr));
122 bzero(&dn->dn_next_nlevels[0], sizeof (dn->dn_next_nlevels));
123 bzero(&dn->dn_next_indblkshift[0], sizeof (dn->dn_next_indblkshift));
124 bzero(&dn->dn_next_bonustype[0], sizeof (dn->dn_next_bonustype));
125 bzero(&dn->dn_rm_spillblk[0], sizeof (dn->dn_rm_spillblk));
126 bzero(&dn->dn_next_bonuslen[0], sizeof (dn->dn_next_bonuslen));
127 bzero(&dn->dn_next_blksz[0], sizeof (dn->dn_next_blksz));
128
129 for (i = 0; i < TXG_SIZE; i++) {
130 list_link_init(&dn->dn_dirty_link[i]);
131 dn->dn_free_ranges[i] = NULL;
132 list_create(&dn->dn_dirty_records[i],
133 sizeof (dbuf_dirty_record_t),
134 offsetof(dbuf_dirty_record_t, dr_dirty_node));
135 }
136
137 dn->dn_allocated_txg = 0;
138 dn->dn_free_txg = 0;
139 dn->dn_assigned_txg = 0;
140 dn->dn_dirtyctx = 0;
141 dn->dn_dirtyctx_firstset = NULL;
142 dn->dn_bonus = NULL;
143 dn->dn_have_spill = B_FALSE;
144 dn->dn_zio = NULL;
145 dn->dn_oldused = 0;
146 dn->dn_oldflags = 0;
147 dn->dn_olduid = 0;
148 dn->dn_oldgid = 0;
149 dn->dn_newuid = 0;
150 dn->dn_newgid = 0;
151 dn->dn_id_flags = 0;
152
153 dn->dn_dbufs_count = 0;
154 dn->dn_unlisted_l0_blkid = 0;
155 avl_create(&dn->dn_dbufs, dbuf_compare, sizeof (dmu_buf_impl_t),
156 offsetof(dmu_buf_impl_t, db_link));
157
158 dn->dn_moved = 0;
159 return (0);
160 }
161
162 /* ARGSUSED */
163 static void
164 dnode_dest(void *arg, void *unused)
165 {
166 int i;
167 dnode_t *dn = arg;
168
169 rw_destroy(&dn->dn_struct_rwlock);
170 mutex_destroy(&dn->dn_mtx);
171 mutex_destroy(&dn->dn_dbufs_mtx);
172 cv_destroy(&dn->dn_notxholds);
173 refcount_destroy(&dn->dn_holds);
174 refcount_destroy(&dn->dn_tx_holds);
175 ASSERT(!list_link_active(&dn->dn_link));
176
177 for (i = 0; i < TXG_SIZE; i++) {
178 ASSERT(!list_link_active(&dn->dn_dirty_link[i]));
179 ASSERT3P(dn->dn_free_ranges[i], ==, NULL);
180 list_destroy(&dn->dn_dirty_records[i]);
181 ASSERT0(dn->dn_next_nblkptr[i]);
182 ASSERT0(dn->dn_next_nlevels[i]);
183 ASSERT0(dn->dn_next_indblkshift[i]);
184 ASSERT0(dn->dn_next_bonustype[i]);
185 ASSERT0(dn->dn_rm_spillblk[i]);
186 ASSERT0(dn->dn_next_bonuslen[i]);
187 ASSERT0(dn->dn_next_blksz[i]);
188 }
189
190 ASSERT0(dn->dn_allocated_txg);
191 ASSERT0(dn->dn_free_txg);
192 ASSERT0(dn->dn_assigned_txg);
193 ASSERT0(dn->dn_dirtyctx);
194 ASSERT3P(dn->dn_dirtyctx_firstset, ==, NULL);
195 ASSERT3P(dn->dn_bonus, ==, NULL);
196 ASSERT(!dn->dn_have_spill);
197 ASSERT3P(dn->dn_zio, ==, NULL);
198 ASSERT0(dn->dn_oldused);
199 ASSERT0(dn->dn_oldflags);
200 ASSERT0(dn->dn_olduid);
201 ASSERT0(dn->dn_oldgid);
202 ASSERT0(dn->dn_newuid);
203 ASSERT0(dn->dn_newgid);
204 ASSERT0(dn->dn_id_flags);
205
206 ASSERT0(dn->dn_dbufs_count);
207 ASSERT0(dn->dn_unlisted_l0_blkid);
208 avl_destroy(&dn->dn_dbufs);
209 }
210
211 void
212 dnode_init(void)
213 {
214 ASSERT(dnode_cache == NULL);
215 dnode_cache = kmem_cache_create("dnode_t",
216 sizeof (dnode_t),
217 0, dnode_cons, dnode_dest, NULL, NULL, NULL, 0);
218 kmem_cache_set_move(dnode_cache, dnode_move);
219 }
220
221 void
222 dnode_fini(void)
223 {
224 kmem_cache_destroy(dnode_cache);
225 dnode_cache = NULL;
226 }
227
228
229 #ifdef ZFS_DEBUG
230 void
231 dnode_verify(dnode_t *dn)
232 {
233 int drop_struct_lock = FALSE;
234
235 ASSERT(dn->dn_phys);
236 ASSERT(dn->dn_objset);
237 ASSERT(dn->dn_handle->dnh_dnode == dn);
238
239 ASSERT(DMU_OT_IS_VALID(dn->dn_phys->dn_type));
240
241 if (!(zfs_flags & ZFS_DEBUG_DNODE_VERIFY))
242 return;
243
244 if (!RW_WRITE_HELD(&dn->dn_struct_rwlock)) {
245 rw_enter(&dn->dn_struct_rwlock, RW_READER);
246 drop_struct_lock = TRUE;
247 }
248 if (dn->dn_phys->dn_type != DMU_OT_NONE || dn->dn_allocated_txg != 0) {
249 int i;
250 ASSERT3U(dn->dn_indblkshift, >=, 0);
251 ASSERT3U(dn->dn_indblkshift, <=, SPA_MAXBLOCKSHIFT);
252 if (dn->dn_datablkshift) {
253 ASSERT3U(dn->dn_datablkshift, >=, SPA_MINBLOCKSHIFT);
254 ASSERT3U(dn->dn_datablkshift, <=, SPA_MAXBLOCKSHIFT);
255 ASSERT3U(1<<dn->dn_datablkshift, ==, dn->dn_datablksz);
256 }
257 ASSERT3U(dn->dn_nlevels, <=, 30);
258 ASSERT(DMU_OT_IS_VALID(dn->dn_type));
259 ASSERT3U(dn->dn_nblkptr, >=, 1);
260 ASSERT3U(dn->dn_nblkptr, <=, DN_MAX_NBLKPTR);
261 ASSERT3U(dn->dn_bonuslen, <=, DN_MAX_BONUSLEN);
262 ASSERT3U(dn->dn_datablksz, ==,
263 dn->dn_datablkszsec << SPA_MINBLOCKSHIFT);
264 ASSERT3U(ISP2(dn->dn_datablksz), ==, dn->dn_datablkshift != 0);
265 ASSERT3U((dn->dn_nblkptr - 1) * sizeof (blkptr_t) +
266 dn->dn_bonuslen, <=, DN_MAX_BONUSLEN);
267 for (i = 0; i < TXG_SIZE; i++) {
268 ASSERT3U(dn->dn_next_nlevels[i], <=, dn->dn_nlevels);
269 }
270 }
271 if (dn->dn_phys->dn_type != DMU_OT_NONE)
272 ASSERT3U(dn->dn_phys->dn_nlevels, <=, dn->dn_nlevels);
273 ASSERT(DMU_OBJECT_IS_SPECIAL(dn->dn_object) || dn->dn_dbuf != NULL);
274 if (dn->dn_dbuf != NULL) {
275 ASSERT3P(dn->dn_phys, ==,
276 (dnode_phys_t *)dn->dn_dbuf->db.db_data +
277 (dn->dn_object % (dn->dn_dbuf->db.db_size >> DNODE_SHIFT)));
278 }
279 if (drop_struct_lock)
280 rw_exit(&dn->dn_struct_rwlock);
281 }
282 #endif
283
284 void
285 dnode_byteswap(dnode_phys_t *dnp)
286 {
287 uint64_t *buf64 = (void*)&dnp->dn_blkptr;
288 int i;
289
290 if (dnp->dn_type == DMU_OT_NONE) {
291 bzero(dnp, sizeof (dnode_phys_t));
292 return;
293 }
294
295 dnp->dn_datablkszsec = BSWAP_16(dnp->dn_datablkszsec);
296 dnp->dn_bonuslen = BSWAP_16(dnp->dn_bonuslen);
297 dnp->dn_maxblkid = BSWAP_64(dnp->dn_maxblkid);
298 dnp->dn_used = BSWAP_64(dnp->dn_used);
299
300 /*
301 * dn_nblkptr is only one byte, so it's OK to read it in either
302 * byte order. We can't read dn_bouslen.
303 */
304 ASSERT(dnp->dn_indblkshift <= SPA_MAXBLOCKSHIFT);
305 ASSERT(dnp->dn_nblkptr <= DN_MAX_NBLKPTR);
306 for (i = 0; i < dnp->dn_nblkptr * sizeof (blkptr_t)/8; i++)
307 buf64[i] = BSWAP_64(buf64[i]);
308
309 /*
310 * OK to check dn_bonuslen for zero, because it won't matter if
311 * we have the wrong byte order. This is necessary because the
312 * dnode dnode is smaller than a regular dnode.
313 */
314 if (dnp->dn_bonuslen != 0) {
315 /*
316 * Note that the bonus length calculated here may be
317 * longer than the actual bonus buffer. This is because
318 * we always put the bonus buffer after the last block
319 * pointer (instead of packing it against the end of the
320 * dnode buffer).
321 */
322 int off = (dnp->dn_nblkptr-1) * sizeof (blkptr_t);
323 size_t len = DN_MAX_BONUSLEN - off;
324 ASSERT(DMU_OT_IS_VALID(dnp->dn_bonustype));
325 dmu_object_byteswap_t byteswap =
326 DMU_OT_BYTESWAP(dnp->dn_bonustype);
327 dmu_ot_byteswap[byteswap].ob_func(dnp->dn_bonus + off, len);
328 }
329
330 /* Swap SPILL block if we have one */
331 if (dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR)
332 byteswap_uint64_array(&dnp->dn_spill, sizeof (blkptr_t));
333
334 }
335
336 void
337 dnode_buf_byteswap(void *vbuf, size_t size)
338 {
339 dnode_phys_t *buf = vbuf;
340 int i;
341
342 ASSERT3U(sizeof (dnode_phys_t), ==, (1<<DNODE_SHIFT));
343 ASSERT((size & (sizeof (dnode_phys_t)-1)) == 0);
344
345 size >>= DNODE_SHIFT;
346 for (i = 0; i < size; i++) {
347 dnode_byteswap(buf);
348 buf++;
349 }
350 }
351
352 void
353 dnode_setbonuslen(dnode_t *dn, int newsize, dmu_tx_t *tx)
354 {
355 ASSERT3U(refcount_count(&dn->dn_holds), >=, 1);
356
357 dnode_setdirty(dn, tx);
358 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
359 ASSERT3U(newsize, <=, DN_MAX_BONUSLEN -
360 (dn->dn_nblkptr-1) * sizeof (blkptr_t));
361 dn->dn_bonuslen = newsize;
362 if (newsize == 0)
363 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = DN_ZERO_BONUSLEN;
364 else
365 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = dn->dn_bonuslen;
366 rw_exit(&dn->dn_struct_rwlock);
367 }
368
369 void
370 dnode_setbonus_type(dnode_t *dn, dmu_object_type_t newtype, dmu_tx_t *tx)
371 {
372 ASSERT3U(refcount_count(&dn->dn_holds), >=, 1);
373 dnode_setdirty(dn, tx);
374 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
375 dn->dn_bonustype = newtype;
376 dn->dn_next_bonustype[tx->tx_txg & TXG_MASK] = dn->dn_bonustype;
377 rw_exit(&dn->dn_struct_rwlock);
378 }
379
380 void
381 dnode_rm_spill(dnode_t *dn, dmu_tx_t *tx)
382 {
383 ASSERT3U(refcount_count(&dn->dn_holds), >=, 1);
384 ASSERT(RW_WRITE_HELD(&dn->dn_struct_rwlock));
385 dnode_setdirty(dn, tx);
386 dn->dn_rm_spillblk[tx->tx_txg&TXG_MASK] = DN_KILL_SPILLBLK;
387 dn->dn_have_spill = B_FALSE;
388 }
389
390 static void
391 dnode_setdblksz(dnode_t *dn, int size)
392 {
393 ASSERT0(P2PHASE(size, SPA_MINBLOCKSIZE));
394 ASSERT3U(size, <=, SPA_MAXBLOCKSIZE);
395 ASSERT3U(size, >=, SPA_MINBLOCKSIZE);
396 ASSERT3U(size >> SPA_MINBLOCKSHIFT, <,
397 1<<(sizeof (dn->dn_phys->dn_datablkszsec) * 8));
398 dn->dn_datablksz = size;
399 dn->dn_datablkszsec = size >> SPA_MINBLOCKSHIFT;
400 dn->dn_datablkshift = ISP2(size) ? highbit64(size - 1) : 0;
401 }
402
403 static dnode_t *
404 dnode_create(objset_t *os, dnode_phys_t *dnp, dmu_buf_impl_t *db,
405 uint64_t object, dnode_handle_t *dnh)
406 {
407 dnode_t *dn = kmem_cache_alloc(dnode_cache, KM_SLEEP);
408
409 ASSERT(!POINTER_IS_VALID(dn->dn_objset));
410 dn->dn_moved = 0;
411
412 /*
413 * Defer setting dn_objset until the dnode is ready to be a candidate
414 * for the dnode_move() callback.
415 */
416 dn->dn_object = object;
417 dn->dn_dbuf = db;
418 dn->dn_handle = dnh;
419 dn->dn_phys = dnp;
420
421 if (dnp->dn_datablkszsec) {
422 dnode_setdblksz(dn, dnp->dn_datablkszsec << SPA_MINBLOCKSHIFT);
423 } else {
424 dn->dn_datablksz = 0;
425 dn->dn_datablkszsec = 0;
426 dn->dn_datablkshift = 0;
427 }
428 dn->dn_indblkshift = dnp->dn_indblkshift;
429 dn->dn_nlevels = dnp->dn_nlevels;
430 dn->dn_type = dnp->dn_type;
431 dn->dn_nblkptr = dnp->dn_nblkptr;
432 dn->dn_checksum = dnp->dn_checksum;
433 dn->dn_compress = dnp->dn_compress;
434 dn->dn_bonustype = dnp->dn_bonustype;
435 dn->dn_bonuslen = dnp->dn_bonuslen;
436 dn->dn_maxblkid = dnp->dn_maxblkid;
437 dn->dn_have_spill = ((dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) != 0);
438 dn->dn_id_flags = 0;
439
440 dmu_zfetch_init(&dn->dn_zfetch, dn);
441
442 ASSERT(DMU_OT_IS_VALID(dn->dn_phys->dn_type));
443
444 mutex_enter(&os->os_lock);
445 list_insert_head(&os->os_dnodes, dn);
446 membar_producer();
447 /*
448 * Everything else must be valid before assigning dn_objset makes the
449 * dnode eligible for dnode_move().
450 */
451 dn->dn_objset = os;
452 mutex_exit(&os->os_lock);
453
454 arc_space_consume(sizeof (dnode_t), ARC_SPACE_OTHER);
455 return (dn);
456 }
457
458 /*
459 * Caller must be holding the dnode handle, which is released upon return.
460 */
461 static void
462 dnode_destroy(dnode_t *dn)
463 {
464 objset_t *os = dn->dn_objset;
465
466 ASSERT((dn->dn_id_flags & DN_ID_NEW_EXIST) == 0);
467
468 mutex_enter(&os->os_lock);
469 POINTER_INVALIDATE(&dn->dn_objset);
470 list_remove(&os->os_dnodes, dn);
471 mutex_exit(&os->os_lock);
472
473 /* the dnode can no longer move, so we can release the handle */
474 zrl_remove(&dn->dn_handle->dnh_zrlock);
475
476 dn->dn_allocated_txg = 0;
477 dn->dn_free_txg = 0;
478 dn->dn_assigned_txg = 0;
479
480 dn->dn_dirtyctx = 0;
481 if (dn->dn_dirtyctx_firstset != NULL) {
482 kmem_free(dn->dn_dirtyctx_firstset, 1);
483 dn->dn_dirtyctx_firstset = NULL;
484 }
485 if (dn->dn_bonus != NULL) {
486 mutex_enter(&dn->dn_bonus->db_mtx);
487 dbuf_evict(dn->dn_bonus);
488 dn->dn_bonus = NULL;
489 }
490 dn->dn_zio = NULL;
491
492 dn->dn_have_spill = B_FALSE;
493 dn->dn_oldused = 0;
494 dn->dn_oldflags = 0;
495 dn->dn_olduid = 0;
496 dn->dn_oldgid = 0;
497 dn->dn_newuid = 0;
498 dn->dn_newgid = 0;
499 dn->dn_id_flags = 0;
500 dn->dn_unlisted_l0_blkid = 0;
501
502 dmu_zfetch_rele(&dn->dn_zfetch);
503 kmem_cache_free(dnode_cache, dn);
504 arc_space_return(sizeof (dnode_t), ARC_SPACE_OTHER);
505 }
506
507 void
508 dnode_allocate(dnode_t *dn, dmu_object_type_t ot, int blocksize, int ibs,
509 dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx)
510 {
511 int i;
512
513 if (blocksize == 0)
514 blocksize = 1 << zfs_default_bs;
515 else if (blocksize > SPA_MAXBLOCKSIZE)
516 blocksize = SPA_MAXBLOCKSIZE;
517 else
518 blocksize = P2ROUNDUP(blocksize, SPA_MINBLOCKSIZE);
519
520 if (ibs == 0)
521 ibs = zfs_default_ibs;
522
523 ibs = MIN(MAX(ibs, DN_MIN_INDBLKSHIFT), DN_MAX_INDBLKSHIFT);
524
525 dprintf("os=%p obj=%llu txg=%llu blocksize=%d ibs=%d\n", dn->dn_objset,
526 dn->dn_object, tx->tx_txg, blocksize, ibs);
527
528 ASSERT(dn->dn_type == DMU_OT_NONE);
529 ASSERT(bcmp(dn->dn_phys, &dnode_phys_zero, sizeof (dnode_phys_t)) == 0);
530 ASSERT(dn->dn_phys->dn_type == DMU_OT_NONE);
531 ASSERT(ot != DMU_OT_NONE);
532 ASSERT(DMU_OT_IS_VALID(ot));
533 ASSERT((bonustype == DMU_OT_NONE && bonuslen == 0) ||
534 (bonustype == DMU_OT_SA && bonuslen == 0) ||
535 (bonustype != DMU_OT_NONE && bonuslen != 0));
536 ASSERT(DMU_OT_IS_VALID(bonustype));
537 ASSERT3U(bonuslen, <=, DN_MAX_BONUSLEN);
538 ASSERT(dn->dn_type == DMU_OT_NONE);
539 ASSERT0(dn->dn_maxblkid);
540 ASSERT0(dn->dn_allocated_txg);
541 ASSERT0(dn->dn_assigned_txg);
542 ASSERT(refcount_is_zero(&dn->dn_tx_holds));
543 ASSERT3U(refcount_count(&dn->dn_holds), <=, 1);
544 ASSERT(avl_is_empty(&dn->dn_dbufs));
545
546 for (i = 0; i < TXG_SIZE; i++) {
547 ASSERT0(dn->dn_next_nblkptr[i]);
548 ASSERT0(dn->dn_next_nlevels[i]);
549 ASSERT0(dn->dn_next_indblkshift[i]);
550 ASSERT0(dn->dn_next_bonuslen[i]);
551 ASSERT0(dn->dn_next_bonustype[i]);
552 ASSERT0(dn->dn_rm_spillblk[i]);
553 ASSERT0(dn->dn_next_blksz[i]);
554 ASSERT(!list_link_active(&dn->dn_dirty_link[i]));
555 ASSERT3P(list_head(&dn->dn_dirty_records[i]), ==, NULL);
556 ASSERT3P(dn->dn_free_ranges[i], ==, NULL);
557 }
558
559 dn->dn_type = ot;
560 dnode_setdblksz(dn, blocksize);
561 dn->dn_indblkshift = ibs;
562 dn->dn_nlevels = 1;
563 if (bonustype == DMU_OT_SA) /* Maximize bonus space for SA */
564 dn->dn_nblkptr = 1;
565 else
566 dn->dn_nblkptr = 1 +
567 ((DN_MAX_BONUSLEN - bonuslen) >> SPA_BLKPTRSHIFT);
568 dn->dn_bonustype = bonustype;
569 dn->dn_bonuslen = bonuslen;
570 dn->dn_checksum = ZIO_CHECKSUM_INHERIT;
571 dn->dn_compress = ZIO_COMPRESS_INHERIT;
572 dn->dn_dirtyctx = 0;
573
574 dn->dn_free_txg = 0;
575 if (dn->dn_dirtyctx_firstset) {
576 kmem_free(dn->dn_dirtyctx_firstset, 1);
577 dn->dn_dirtyctx_firstset = NULL;
578 }
579
580 dn->dn_allocated_txg = tx->tx_txg;
581 dn->dn_id_flags = 0;
582
583 dnode_setdirty(dn, tx);
584 dn->dn_next_indblkshift[tx->tx_txg & TXG_MASK] = ibs;
585 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = dn->dn_bonuslen;
586 dn->dn_next_bonustype[tx->tx_txg & TXG_MASK] = dn->dn_bonustype;
587 dn->dn_next_blksz[tx->tx_txg & TXG_MASK] = dn->dn_datablksz;
588 }
589
590 void
591 dnode_reallocate(dnode_t *dn, dmu_object_type_t ot, int blocksize,
592 dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx)
593 {
594 int nblkptr;
595
596 ASSERT3U(blocksize, >=, SPA_MINBLOCKSIZE);
597 ASSERT3U(blocksize, <=, SPA_MAXBLOCKSIZE);
598 ASSERT0(blocksize % SPA_MINBLOCKSIZE);
599 ASSERT(dn->dn_object != DMU_META_DNODE_OBJECT || dmu_tx_private_ok(tx));
600 ASSERT(tx->tx_txg != 0);
601 ASSERT((bonustype == DMU_OT_NONE && bonuslen == 0) ||
602 (bonustype != DMU_OT_NONE && bonuslen != 0) ||
603 (bonustype == DMU_OT_SA && bonuslen == 0));
604 ASSERT(DMU_OT_IS_VALID(bonustype));
605 ASSERT3U(bonuslen, <=, DN_MAX_BONUSLEN);
606
607 /* clean up any unreferenced dbufs */
608 dnode_evict_dbufs(dn);
609
610 dn->dn_id_flags = 0;
611
612 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
613 dnode_setdirty(dn, tx);
614 if (dn->dn_datablksz != blocksize) {
615 /* change blocksize */
616 ASSERT(dn->dn_maxblkid == 0 &&
617 (BP_IS_HOLE(&dn->dn_phys->dn_blkptr[0]) ||
618 dnode_block_freed(dn, 0)));
619 dnode_setdblksz(dn, blocksize);
620 dn->dn_next_blksz[tx->tx_txg&TXG_MASK] = blocksize;
621 }
622 if (dn->dn_bonuslen != bonuslen)
623 dn->dn_next_bonuslen[tx->tx_txg&TXG_MASK] = bonuslen;
624
625 if (bonustype == DMU_OT_SA) /* Maximize bonus space for SA */
626 nblkptr = 1;
627 else
628 nblkptr = 1 + ((DN_MAX_BONUSLEN - bonuslen) >> SPA_BLKPTRSHIFT);
629 if (dn->dn_bonustype != bonustype)
630 dn->dn_next_bonustype[tx->tx_txg&TXG_MASK] = bonustype;
631 if (dn->dn_nblkptr != nblkptr)
632 dn->dn_next_nblkptr[tx->tx_txg&TXG_MASK] = nblkptr;
633 if (dn->dn_phys->dn_flags & DNODE_FLAG_SPILL_BLKPTR) {
634 dbuf_rm_spill(dn, tx);
635 dnode_rm_spill(dn, tx);
636 }
637 rw_exit(&dn->dn_struct_rwlock);
638
639 /* change type */
640 dn->dn_type = ot;
641
642 /* change bonus size and type */
643 mutex_enter(&dn->dn_mtx);
644 dn->dn_bonustype = bonustype;
645 dn->dn_bonuslen = bonuslen;
646 dn->dn_nblkptr = nblkptr;
647 dn->dn_checksum = ZIO_CHECKSUM_INHERIT;
648 dn->dn_compress = ZIO_COMPRESS_INHERIT;
649 ASSERT3U(dn->dn_nblkptr, <=, DN_MAX_NBLKPTR);
650
651 /* fix up the bonus db_size */
652 if (dn->dn_bonus) {
653 dn->dn_bonus->db.db_size =
654 DN_MAX_BONUSLEN - (dn->dn_nblkptr-1) * sizeof (blkptr_t);
655 ASSERT(dn->dn_bonuslen <= dn->dn_bonus->db.db_size);
656 }
657
658 dn->dn_allocated_txg = tx->tx_txg;
659 mutex_exit(&dn->dn_mtx);
660 }
661
662 #ifdef DNODE_STATS
663 static struct {
664 uint64_t dms_dnode_invalid;
665 uint64_t dms_dnode_recheck1;
666 uint64_t dms_dnode_recheck2;
667 uint64_t dms_dnode_special;
668 uint64_t dms_dnode_handle;
669 uint64_t dms_dnode_rwlock;
670 uint64_t dms_dnode_active;
671 } dnode_move_stats;
672 #endif /* DNODE_STATS */
673
674 static void
675 dnode_move_impl(dnode_t *odn, dnode_t *ndn)
676 {
677 int i;
678
679 ASSERT(!RW_LOCK_HELD(&odn->dn_struct_rwlock));
680 ASSERT(MUTEX_NOT_HELD(&odn->dn_mtx));
681 ASSERT(MUTEX_NOT_HELD(&odn->dn_dbufs_mtx));
682 ASSERT(!RW_LOCK_HELD(&odn->dn_zfetch.zf_rwlock));
683
684 /* Copy fields. */
685 ndn->dn_objset = odn->dn_objset;
686 ndn->dn_object = odn->dn_object;
687 ndn->dn_dbuf = odn->dn_dbuf;
688 ndn->dn_handle = odn->dn_handle;
689 ndn->dn_phys = odn->dn_phys;
690 ndn->dn_type = odn->dn_type;
691 ndn->dn_bonuslen = odn->dn_bonuslen;
692 ndn->dn_bonustype = odn->dn_bonustype;
693 ndn->dn_nblkptr = odn->dn_nblkptr;
694 ndn->dn_checksum = odn->dn_checksum;
695 ndn->dn_compress = odn->dn_compress;
696 ndn->dn_nlevels = odn->dn_nlevels;
697 ndn->dn_indblkshift = odn->dn_indblkshift;
698 ndn->dn_datablkshift = odn->dn_datablkshift;
699 ndn->dn_datablkszsec = odn->dn_datablkszsec;
700 ndn->dn_datablksz = odn->dn_datablksz;
701 ndn->dn_maxblkid = odn->dn_maxblkid;
702 bcopy(&odn->dn_next_nblkptr[0], &ndn->dn_next_nblkptr[0],
703 sizeof (odn->dn_next_nblkptr));
704 bcopy(&odn->dn_next_nlevels[0], &ndn->dn_next_nlevels[0],
705 sizeof (odn->dn_next_nlevels));
706 bcopy(&odn->dn_next_indblkshift[0], &ndn->dn_next_indblkshift[0],
707 sizeof (odn->dn_next_indblkshift));
708 bcopy(&odn->dn_next_bonustype[0], &ndn->dn_next_bonustype[0],
709 sizeof (odn->dn_next_bonustype));
710 bcopy(&odn->dn_rm_spillblk[0], &ndn->dn_rm_spillblk[0],
711 sizeof (odn->dn_rm_spillblk));
712 bcopy(&odn->dn_next_bonuslen[0], &ndn->dn_next_bonuslen[0],
713 sizeof (odn->dn_next_bonuslen));
714 bcopy(&odn->dn_next_blksz[0], &ndn->dn_next_blksz[0],
715 sizeof (odn->dn_next_blksz));
716 for (i = 0; i < TXG_SIZE; i++) {
717 list_move_tail(&ndn->dn_dirty_records[i],
718 &odn->dn_dirty_records[i]);
719 }
720 bcopy(&odn->dn_free_ranges[0], &ndn->dn_free_ranges[0],
721 sizeof (odn->dn_free_ranges));
722 ndn->dn_allocated_txg = odn->dn_allocated_txg;
723 ndn->dn_free_txg = odn->dn_free_txg;
724 ndn->dn_assigned_txg = odn->dn_assigned_txg;
725 ndn->dn_dirtyctx = odn->dn_dirtyctx;
726 ndn->dn_dirtyctx_firstset = odn->dn_dirtyctx_firstset;
727 ASSERT(refcount_count(&odn->dn_tx_holds) == 0);
728 refcount_transfer(&ndn->dn_holds, &odn->dn_holds);
729 ASSERT(avl_is_empty(&ndn->dn_dbufs));
730 avl_swap(&ndn->dn_dbufs, &odn->dn_dbufs);
731 ndn->dn_dbufs_count = odn->dn_dbufs_count;
732 ndn->dn_unlisted_l0_blkid = odn->dn_unlisted_l0_blkid;
733 ndn->dn_bonus = odn->dn_bonus;
734 ndn->dn_have_spill = odn->dn_have_spill;
735 ndn->dn_zio = odn->dn_zio;
736 ndn->dn_oldused = odn->dn_oldused;
737 ndn->dn_oldflags = odn->dn_oldflags;
738 ndn->dn_olduid = odn->dn_olduid;
739 ndn->dn_oldgid = odn->dn_oldgid;
740 ndn->dn_newuid = odn->dn_newuid;
741 ndn->dn_newgid = odn->dn_newgid;
742 ndn->dn_id_flags = odn->dn_id_flags;
743 dmu_zfetch_init(&ndn->dn_zfetch, NULL);
744 list_move_tail(&ndn->dn_zfetch.zf_stream, &odn->dn_zfetch.zf_stream);
745 ndn->dn_zfetch.zf_dnode = odn->dn_zfetch.zf_dnode;
746 ndn->dn_zfetch.zf_stream_cnt = odn->dn_zfetch.zf_stream_cnt;
747 ndn->dn_zfetch.zf_alloc_fail = odn->dn_zfetch.zf_alloc_fail;
748
749 /*
750 * Update back pointers. Updating the handle fixes the back pointer of
751 * every descendant dbuf as well as the bonus dbuf.
752 */
753 ASSERT(ndn->dn_handle->dnh_dnode == odn);
754 ndn->dn_handle->dnh_dnode = ndn;
755 if (ndn->dn_zfetch.zf_dnode == odn) {
756 ndn->dn_zfetch.zf_dnode = ndn;
757 }
758
759 /*
760 * Invalidate the original dnode by clearing all of its back pointers.
761 */
762 odn->dn_dbuf = NULL;
763 odn->dn_handle = NULL;
764 avl_create(&odn->dn_dbufs, dbuf_compare, sizeof (dmu_buf_impl_t),
765 offsetof(dmu_buf_impl_t, db_link));
766 odn->dn_dbufs_count = 0;
767 odn->dn_unlisted_l0_blkid = 0;
768 odn->dn_bonus = NULL;
769 odn->dn_zfetch.zf_dnode = NULL;
770
771 /*
772 * Set the low bit of the objset pointer to ensure that dnode_move()
773 * recognizes the dnode as invalid in any subsequent callback.
774 */
775 POINTER_INVALIDATE(&odn->dn_objset);
776
777 /*
778 * Satisfy the destructor.
779 */
780 for (i = 0; i < TXG_SIZE; i++) {
781 list_create(&odn->dn_dirty_records[i],
782 sizeof (dbuf_dirty_record_t),
783 offsetof(dbuf_dirty_record_t, dr_dirty_node));
784 odn->dn_free_ranges[i] = NULL;
785 odn->dn_next_nlevels[i] = 0;
786 odn->dn_next_indblkshift[i] = 0;
787 odn->dn_next_bonustype[i] = 0;
788 odn->dn_rm_spillblk[i] = 0;
789 odn->dn_next_bonuslen[i] = 0;
790 odn->dn_next_blksz[i] = 0;
791 }
792 odn->dn_allocated_txg = 0;
793 odn->dn_free_txg = 0;
794 odn->dn_assigned_txg = 0;
795 odn->dn_dirtyctx = 0;
796 odn->dn_dirtyctx_firstset = NULL;
797 odn->dn_have_spill = B_FALSE;
798 odn->dn_zio = NULL;
799 odn->dn_oldused = 0;
800 odn->dn_oldflags = 0;
801 odn->dn_olduid = 0;
802 odn->dn_oldgid = 0;
803 odn->dn_newuid = 0;
804 odn->dn_newgid = 0;
805 odn->dn_id_flags = 0;
806
807 /*
808 * Mark the dnode.
809 */
810 ndn->dn_moved = 1;
811 odn->dn_moved = (uint8_t)-1;
812 }
813
814 #ifdef _KERNEL
815 /*ARGSUSED*/
816 static kmem_cbrc_t
817 dnode_move(void *buf, void *newbuf, size_t size, void *arg)
818 {
819 dnode_t *odn = buf, *ndn = newbuf;
820 objset_t *os;
821 int64_t refcount;
822 uint32_t dbufs;
823
824 /*
825 * The dnode is on the objset's list of known dnodes if the objset
826 * pointer is valid. We set the low bit of the objset pointer when
827 * freeing the dnode to invalidate it, and the memory patterns written
828 * by kmem (baddcafe and deadbeef) set at least one of the two low bits.
829 * A newly created dnode sets the objset pointer last of all to indicate
830 * that the dnode is known and in a valid state to be moved by this
831 * function.
832 */
833 os = odn->dn_objset;
834 if (!POINTER_IS_VALID(os)) {
835 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_invalid);
836 return (KMEM_CBRC_DONT_KNOW);
837 }
838
839 /*
840 * Ensure that the objset does not go away during the move.
841 */
842 rw_enter(&os_lock, RW_WRITER);
843 if (os != odn->dn_objset) {
844 rw_exit(&os_lock);
845 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_recheck1);
846 return (KMEM_CBRC_DONT_KNOW);
847 }
848
849 /*
850 * If the dnode is still valid, then so is the objset. We know that no
851 * valid objset can be freed while we hold os_lock, so we can safely
852 * ensure that the objset remains in use.
853 */
854 mutex_enter(&os->os_lock);
855
856 /*
857 * Recheck the objset pointer in case the dnode was removed just before
858 * acquiring the lock.
859 */
860 if (os != odn->dn_objset) {
861 mutex_exit(&os->os_lock);
862 rw_exit(&os_lock);
863 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_recheck2);
864 return (KMEM_CBRC_DONT_KNOW);
865 }
866
867 /*
868 * At this point we know that as long as we hold os->os_lock, the dnode
869 * cannot be freed and fields within the dnode can be safely accessed.
870 * The objset listing this dnode cannot go away as long as this dnode is
871 * on its list.
872 */
873 rw_exit(&os_lock);
874 if (DMU_OBJECT_IS_SPECIAL(odn->dn_object)) {
875 mutex_exit(&os->os_lock);
876 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_special);
877 return (KMEM_CBRC_NO);
878 }
879 ASSERT(odn->dn_dbuf != NULL); /* only "special" dnodes have no parent */
880
881 /*
882 * Lock the dnode handle to prevent the dnode from obtaining any new
883 * holds. This also prevents the descendant dbufs and the bonus dbuf
884 * from accessing the dnode, so that we can discount their holds. The
885 * handle is safe to access because we know that while the dnode cannot
886 * go away, neither can its handle. Once we hold dnh_zrlock, we can
887 * safely move any dnode referenced only by dbufs.
888 */
889 if (!zrl_tryenter(&odn->dn_handle->dnh_zrlock)) {
890 mutex_exit(&os->os_lock);
891 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_handle);
892 return (KMEM_CBRC_LATER);
893 }
894
895 /*
896 * Ensure a consistent view of the dnode's holds and the dnode's dbufs.
897 * We need to guarantee that there is a hold for every dbuf in order to
898 * determine whether the dnode is actively referenced. Falsely matching
899 * a dbuf to an active hold would lead to an unsafe move. It's possible
900 * that a thread already having an active dnode hold is about to add a
901 * dbuf, and we can't compare hold and dbuf counts while the add is in
902 * progress.
903 */
904 if (!rw_tryenter(&odn->dn_struct_rwlock, RW_WRITER)) {
905 zrl_exit(&odn->dn_handle->dnh_zrlock);
906 mutex_exit(&os->os_lock);
907 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_rwlock);
908 return (KMEM_CBRC_LATER);
909 }
910
911 /*
912 * A dbuf may be removed (evicted) without an active dnode hold. In that
913 * case, the dbuf count is decremented under the handle lock before the
914 * dbuf's hold is released. This order ensures that if we count the hold
915 * after the dbuf is removed but before its hold is released, we will
916 * treat the unmatched hold as active and exit safely. If we count the
917 * hold before the dbuf is removed, the hold is discounted, and the
918 * removal is blocked until the move completes.
919 */
920 refcount = refcount_count(&odn->dn_holds);
921 ASSERT(refcount >= 0);
922 dbufs = odn->dn_dbufs_count;
923
924 /* We can't have more dbufs than dnode holds. */
925 ASSERT3U(dbufs, <=, refcount);
926 DTRACE_PROBE3(dnode__move, dnode_t *, odn, int64_t, refcount,
927 uint32_t, dbufs);
928
929 if (refcount > dbufs) {
930 rw_exit(&odn->dn_struct_rwlock);
931 zrl_exit(&odn->dn_handle->dnh_zrlock);
932 mutex_exit(&os->os_lock);
933 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_active);
934 return (KMEM_CBRC_LATER);
935 }
936
937 rw_exit(&odn->dn_struct_rwlock);
938
939 /*
940 * At this point we know that anyone with a hold on the dnode is not
941 * actively referencing it. The dnode is known and in a valid state to
942 * move. We're holding the locks needed to execute the critical section.
943 */
944 dnode_move_impl(odn, ndn);
945
946 list_link_replace(&odn->dn_link, &ndn->dn_link);
947 /* If the dnode was safe to move, the refcount cannot have changed. */
948 ASSERT(refcount == refcount_count(&ndn->dn_holds));
949 ASSERT(dbufs == ndn->dn_dbufs_count);
950 zrl_exit(&ndn->dn_handle->dnh_zrlock); /* handle has moved */
951 mutex_exit(&os->os_lock);
952
953 return (KMEM_CBRC_YES);
954 }
955 #endif /* _KERNEL */
956
957 void
958 dnode_special_close(dnode_handle_t *dnh)
959 {
960 dnode_t *dn = dnh->dnh_dnode;
961
962 /*
963 * Wait for final references to the dnode to clear. This can
964 * only happen if the arc is asyncronously evicting state that
965 * has a hold on this dnode while we are trying to evict this
966 * dnode.
967 */
968 while (refcount_count(&dn->dn_holds) > 0)
969 delay(1);
970 zrl_add(&dnh->dnh_zrlock);
971 dnode_destroy(dn); /* implicit zrl_remove() */
972 zrl_destroy(&dnh->dnh_zrlock);
973 dnh->dnh_dnode = NULL;
974 }
975
976 dnode_t *
977 dnode_special_open(objset_t *os, dnode_phys_t *dnp, uint64_t object,
978 dnode_handle_t *dnh)
979 {
980 dnode_t *dn = dnode_create(os, dnp, NULL, object, dnh);
981 dnh->dnh_dnode = dn;
982 zrl_init(&dnh->dnh_zrlock);
983 DNODE_VERIFY(dn);
984 return (dn);
985 }
986
987 static void
988 dnode_buf_pageout(dmu_buf_t *db, void *arg)
989 {
990 dnode_children_t *children_dnodes = arg;
991 int i;
992 int epb = db->db_size >> DNODE_SHIFT;
993
994 ASSERT(epb == children_dnodes->dnc_count);
995
996 for (i = 0; i < epb; i++) {
997 dnode_handle_t *dnh = &children_dnodes->dnc_children[i];
998 dnode_t *dn;
999
1000 /*
1001 * The dnode handle lock guards against the dnode moving to
1002 * another valid address, so there is no need here to guard
1003 * against changes to or from NULL.
1004 */
1005 if (dnh->dnh_dnode == NULL) {
1006 zrl_destroy(&dnh->dnh_zrlock);
1007 continue;
1008 }
1009
1010 zrl_add(&dnh->dnh_zrlock);
1011 dn = dnh->dnh_dnode;
1012 /*
1013 * If there are holds on this dnode, then there should
1014 * be holds on the dnode's containing dbuf as well; thus
1015 * it wouldn't be eligible for eviction and this function
1016 * would not have been called.
1017 */
1018 ASSERT(refcount_is_zero(&dn->dn_holds));
1019 ASSERT(refcount_is_zero(&dn->dn_tx_holds));
1020
1021 dnode_destroy(dn); /* implicit zrl_remove() */
1022 zrl_destroy(&dnh->dnh_zrlock);
1023 dnh->dnh_dnode = NULL;
1024 }
1025 kmem_free(children_dnodes, sizeof (dnode_children_t) +
1026 epb * sizeof (dnode_handle_t));
1027 }
1028
1029 /*
1030 * errors:
1031 * EINVAL - invalid object number.
1032 * EIO - i/o error.
1033 * succeeds even for free dnodes.
1034 */
1035 int
1036 dnode_hold_impl(objset_t *os, uint64_t object, int flag,
1037 void *tag, dnode_t **dnp)
1038 {
1039 int epb, idx, err;
1040 int drop_struct_lock = FALSE;
1041 int type;
1042 uint64_t blk;
1043 dnode_t *mdn, *dn;
1044 dmu_buf_impl_t *db;
1045 dnode_children_t *children_dnodes;
1046 dnode_handle_t *dnh;
1047
1048 /*
1049 * If you are holding the spa config lock as writer, you shouldn't
1050 * be asking the DMU to do *anything* unless it's the root pool
1051 * which may require us to read from the root filesystem while
1052 * holding some (not all) of the locks as writer.
1053 */
1054 ASSERT(spa_config_held(os->os_spa, SCL_ALL, RW_WRITER) == 0 ||
1055 (spa_is_root(os->os_spa) &&
1056 spa_config_held(os->os_spa, SCL_STATE, RW_WRITER)));
1057
1058 if (object == DMU_USERUSED_OBJECT || object == DMU_GROUPUSED_OBJECT) {
1059 dn = (object == DMU_USERUSED_OBJECT) ?
1060 DMU_USERUSED_DNODE(os) : DMU_GROUPUSED_DNODE(os);
1061 if (dn == NULL)
1062 return (SET_ERROR(ENOENT));
1063 type = dn->dn_type;
1064 if ((flag & DNODE_MUST_BE_ALLOCATED) && type == DMU_OT_NONE)
1065 return (SET_ERROR(ENOENT));
1066 if ((flag & DNODE_MUST_BE_FREE) && type != DMU_OT_NONE)
1067 return (SET_ERROR(EEXIST));
1068 DNODE_VERIFY(dn);
1069 (void) refcount_add(&dn->dn_holds, tag);
1070 *dnp = dn;
1071 return (0);
1072 }
1073
1074 if (object == 0 || object >= DN_MAX_OBJECT)
1075 return (SET_ERROR(EINVAL));
1076
1077 mdn = DMU_META_DNODE(os);
1078 ASSERT(mdn->dn_object == DMU_META_DNODE_OBJECT);
1079
1080 DNODE_VERIFY(mdn);
1081
1082 if (!RW_WRITE_HELD(&mdn->dn_struct_rwlock)) {
1083 rw_enter(&mdn->dn_struct_rwlock, RW_READER);
1084 drop_struct_lock = TRUE;
1085 }
1086
1087 blk = dbuf_whichblock(mdn, object * sizeof (dnode_phys_t));
1088
1089 db = dbuf_hold(mdn, blk, FTAG);
1090 if (drop_struct_lock)
1091 rw_exit(&mdn->dn_struct_rwlock);
1092 if (db == NULL)
1093 return (SET_ERROR(EIO));
1094 err = dbuf_read(db, NULL, DB_RF_CANFAIL);
1095 if (err) {
1096 dbuf_rele(db, FTAG);
1097 return (err);
1098 }
1099
1100 ASSERT3U(db->db.db_size, >=, 1<<DNODE_SHIFT);
1101 epb = db->db.db_size >> DNODE_SHIFT;
1102
1103 idx = object & (epb-1);
1104
1105 ASSERT(DB_DNODE(db)->dn_type == DMU_OT_DNODE);
1106 children_dnodes = dmu_buf_get_user(&db->db);
1107 if (children_dnodes == NULL) {
1108 int i;
1109 dnode_children_t *winner;
1110 children_dnodes = kmem_alloc(sizeof (dnode_children_t) +
1111 epb * sizeof (dnode_handle_t), KM_SLEEP);
1112 children_dnodes->dnc_count = epb;
1113 dnh = &children_dnodes->dnc_children[0];
1114 for (i = 0; i < epb; i++) {
1115 zrl_init(&dnh[i].dnh_zrlock);
1116 dnh[i].dnh_dnode = NULL;
1117 }
1118 if (winner = dmu_buf_set_user(&db->db, children_dnodes, NULL,
1119 dnode_buf_pageout)) {
1120
1121 for (i = 0; i < epb; i++) {
1122 zrl_destroy(&dnh[i].dnh_zrlock);
1123 }
1124
1125 kmem_free(children_dnodes, sizeof (dnode_children_t) +
1126 epb * sizeof (dnode_handle_t));
1127 children_dnodes = winner;
1128 }
1129 }
1130 ASSERT(children_dnodes->dnc_count == epb);
1131
1132 dnh = &children_dnodes->dnc_children[idx];
1133 zrl_add(&dnh->dnh_zrlock);
1134 if ((dn = dnh->dnh_dnode) == NULL) {
1135 dnode_phys_t *phys = (dnode_phys_t *)db->db.db_data+idx;
1136 dnode_t *winner;
1137
1138 dn = dnode_create(os, phys, db, object, dnh);
1139 winner = atomic_cas_ptr(&dnh->dnh_dnode, NULL, dn);
1140 if (winner != NULL) {
1141 zrl_add(&dnh->dnh_zrlock);
1142 dnode_destroy(dn); /* implicit zrl_remove() */
1143 dn = winner;
1144 }
1145 }
1146
1147 mutex_enter(&dn->dn_mtx);
1148 type = dn->dn_type;
1149 if (dn->dn_free_txg ||
1150 ((flag & DNODE_MUST_BE_ALLOCATED) && type == DMU_OT_NONE) ||
1151 ((flag & DNODE_MUST_BE_FREE) &&
1152 (type != DMU_OT_NONE || !refcount_is_zero(&dn->dn_holds)))) {
1153 mutex_exit(&dn->dn_mtx);
1154 zrl_remove(&dnh->dnh_zrlock);
1155 dbuf_rele(db, FTAG);
1156 return (type == DMU_OT_NONE ? ENOENT : EEXIST);
1157 }
1158 mutex_exit(&dn->dn_mtx);
1159
1160 if (refcount_add(&dn->dn_holds, tag) == 1)
1161 dbuf_add_ref(db, dnh);
1162 /* Now we can rely on the hold to prevent the dnode from moving. */
1163 zrl_remove(&dnh->dnh_zrlock);
1164
1165 DNODE_VERIFY(dn);
1166 ASSERT3P(dn->dn_dbuf, ==, db);
1167 ASSERT3U(dn->dn_object, ==, object);
1168 dbuf_rele(db, FTAG);
1169
1170 *dnp = dn;
1171 return (0);
1172 }
1173
1174 /*
1175 * Return held dnode if the object is allocated, NULL if not.
1176 */
1177 int
1178 dnode_hold(objset_t *os, uint64_t object, void *tag, dnode_t **dnp)
1179 {
1180 return (dnode_hold_impl(os, object, DNODE_MUST_BE_ALLOCATED, tag, dnp));
1181 }
1182
1183 /*
1184 * Can only add a reference if there is already at least one
1185 * reference on the dnode. Returns FALSE if unable to add a
1186 * new reference.
1187 */
1188 boolean_t
1189 dnode_add_ref(dnode_t *dn, void *tag)
1190 {
1191 mutex_enter(&dn->dn_mtx);
1192 if (refcount_is_zero(&dn->dn_holds)) {
1193 mutex_exit(&dn->dn_mtx);
1194 return (FALSE);
1195 }
1196 VERIFY(1 < refcount_add(&dn->dn_holds, tag));
1197 mutex_exit(&dn->dn_mtx);
1198 return (TRUE);
1199 }
1200
1201 void
1202 dnode_rele(dnode_t *dn, void *tag)
1203 {
1204 uint64_t refs;
1205 /* Get while the hold prevents the dnode from moving. */
1206 dmu_buf_impl_t *db = dn->dn_dbuf;
1207 dnode_handle_t *dnh = dn->dn_handle;
1208
1209 mutex_enter(&dn->dn_mtx);
1210 refs = refcount_remove(&dn->dn_holds, tag);
1211 mutex_exit(&dn->dn_mtx);
1212
1213 /*
1214 * It's unsafe to release the last hold on a dnode by dnode_rele() or
1215 * indirectly by dbuf_rele() while relying on the dnode handle to
1216 * prevent the dnode from moving, since releasing the last hold could
1217 * result in the dnode's parent dbuf evicting its dnode handles. For
1218 * that reason anyone calling dnode_rele() or dbuf_rele() without some
1219 * other direct or indirect hold on the dnode must first drop the dnode
1220 * handle.
1221 */
1222 ASSERT(refs > 0 || dnh->dnh_zrlock.zr_owner != curthread);
1223
1224 /* NOTE: the DNODE_DNODE does not have a dn_dbuf */
1225 if (refs == 0 && db != NULL) {
1226 /*
1227 * Another thread could add a hold to the dnode handle in
1228 * dnode_hold_impl() while holding the parent dbuf. Since the
1229 * hold on the parent dbuf prevents the handle from being
1230 * destroyed, the hold on the handle is OK. We can't yet assert
1231 * that the handle has zero references, but that will be
1232 * asserted anyway when the handle gets destroyed.
1233 */
1234 dbuf_rele(db, dnh);
1235 }
1236 }
1237
1238 void
1239 dnode_setdirty(dnode_t *dn, dmu_tx_t *tx)
1240 {
1241 objset_t *os = dn->dn_objset;
1242 uint64_t txg = tx->tx_txg;
1243
1244 if (DMU_OBJECT_IS_SPECIAL(dn->dn_object)) {
1245 dsl_dataset_dirty(os->os_dsl_dataset, tx);
1246 return;
1247 }
1248
1249 DNODE_VERIFY(dn);
1250
1251 #ifdef ZFS_DEBUG
1252 mutex_enter(&dn->dn_mtx);
1253 ASSERT(dn->dn_phys->dn_type || dn->dn_allocated_txg);
1254 ASSERT(dn->dn_free_txg == 0 || dn->dn_free_txg >= txg);
1255 mutex_exit(&dn->dn_mtx);
1256 #endif
1257
1258 /*
1259 * Determine old uid/gid when necessary
1260 */
1261 dmu_objset_userquota_get_ids(dn, B_TRUE, tx);
1262
1263 mutex_enter(&os->os_lock);
1264
1265 /*
1266 * If we are already marked dirty, we're done.
1267 */
1268 if (list_link_active(&dn->dn_dirty_link[txg & TXG_MASK])) {
1269 mutex_exit(&os->os_lock);
1270 return;
1271 }
1272
1273 ASSERT(!refcount_is_zero(&dn->dn_holds) ||
1274 !avl_is_empty(&dn->dn_dbufs));
1275 ASSERT(dn->dn_datablksz != 0);
1276 ASSERT0(dn->dn_next_bonuslen[txg&TXG_MASK]);
1277 ASSERT0(dn->dn_next_blksz[txg&TXG_MASK]);
1278 ASSERT0(dn->dn_next_bonustype[txg&TXG_MASK]);
1279
1280 dprintf_ds(os->os_dsl_dataset, "obj=%llu txg=%llu\n",
1281 dn->dn_object, txg);
1282
1283 if (dn->dn_free_txg > 0 && dn->dn_free_txg <= txg) {
1284 list_insert_tail(&os->os_free_dnodes[txg&TXG_MASK], dn);
1285 } else {
1286 list_insert_tail(&os->os_dirty_dnodes[txg&TXG_MASK], dn);
1287 }
1288
1289 mutex_exit(&os->os_lock);
1290
1291 /*
1292 * The dnode maintains a hold on its containing dbuf as
1293 * long as there are holds on it. Each instantiated child
1294 * dbuf maintains a hold on the dnode. When the last child
1295 * drops its hold, the dnode will drop its hold on the
1296 * containing dbuf. We add a "dirty hold" here so that the
1297 * dnode will hang around after we finish processing its
1298 * children.
1299 */
1300 VERIFY(dnode_add_ref(dn, (void *)(uintptr_t)tx->tx_txg));
1301
1302 (void) dbuf_dirty(dn->dn_dbuf, tx, B_FALSE);
1303
1304 dsl_dataset_dirty(os->os_dsl_dataset, tx);
1305 }
1306
1307 void
1308 dnode_free(dnode_t *dn, dmu_tx_t *tx)
1309 {
1310 int txgoff = tx->tx_txg & TXG_MASK;
1311
1312 dprintf("dn=%p txg=%llu\n", dn, tx->tx_txg);
1313
1314 /* we should be the only holder... hopefully */
1315 /* ASSERT3U(refcount_count(&dn->dn_holds), ==, 1); */
1316
1317 mutex_enter(&dn->dn_mtx);
1318 if (dn->dn_type == DMU_OT_NONE || dn->dn_free_txg) {
1319 mutex_exit(&dn->dn_mtx);
1320 return;
1321 }
1322 dn->dn_free_txg = tx->tx_txg;
1323 mutex_exit(&dn->dn_mtx);
1324
1325 /*
1326 * If the dnode is already dirty, it needs to be moved from
1327 * the dirty list to the free list.
1328 */
1329 mutex_enter(&dn->dn_objset->os_lock);
1330 if (list_link_active(&dn->dn_dirty_link[txgoff])) {
1331 list_remove(&dn->dn_objset->os_dirty_dnodes[txgoff], dn);
1332 list_insert_tail(&dn->dn_objset->os_free_dnodes[txgoff], dn);
1333 mutex_exit(&dn->dn_objset->os_lock);
1334 } else {
1335 mutex_exit(&dn->dn_objset->os_lock);
1336 dnode_setdirty(dn, tx);
1337 }
1338 }
1339
1340 /*
1341 * Try to change the block size for the indicated dnode. This can only
1342 * succeed if there are no blocks allocated or dirty beyond first block
1343 */
1344 int
1345 dnode_set_blksz(dnode_t *dn, uint64_t size, int ibs, dmu_tx_t *tx)
1346 {
1347 dmu_buf_impl_t *db;
1348 int err;
1349
1350 if (size == 0)
1351 size = SPA_MINBLOCKSIZE;
1352 if (size > SPA_MAXBLOCKSIZE)
1353 size = SPA_MAXBLOCKSIZE;
1354 else
1355 size = P2ROUNDUP(size, SPA_MINBLOCKSIZE);
1356
1357 if (ibs == dn->dn_indblkshift)
1358 ibs = 0;
1359
1360 if (size >> SPA_MINBLOCKSHIFT == dn->dn_datablkszsec && ibs == 0)
1361 return (0);
1362
1363 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
1364
1365 /* Check for any allocated blocks beyond the first */
1366 if (dn->dn_maxblkid != 0)
1367 goto fail;
1368
1369 mutex_enter(&dn->dn_dbufs_mtx);
1370 for (db = avl_first(&dn->dn_dbufs); db != NULL;
1371 db = AVL_NEXT(&dn->dn_dbufs, db)) {
1372 if (db->db_blkid != 0 && db->db_blkid != DMU_BONUS_BLKID &&
1373 db->db_blkid != DMU_SPILL_BLKID) {
1374 mutex_exit(&dn->dn_dbufs_mtx);
1375 goto fail;
1376 }
1377 }
1378 mutex_exit(&dn->dn_dbufs_mtx);
1379
1380 if (ibs && dn->dn_nlevels != 1)
1381 goto fail;
1382
1383 /* resize the old block */
1384 err = dbuf_hold_impl(dn, 0, 0, TRUE, FTAG, &db);
1385 if (err == 0)
1386 dbuf_new_size(db, size, tx);
1387 else if (err != ENOENT)
1388 goto fail;
1389
1390 dnode_setdblksz(dn, size);
1391 dnode_setdirty(dn, tx);
1392 dn->dn_next_blksz[tx->tx_txg&TXG_MASK] = size;
1393 if (ibs) {
1394 dn->dn_indblkshift = ibs;
1395 dn->dn_next_indblkshift[tx->tx_txg&TXG_MASK] = ibs;
1396 }
1397 /* rele after we have fixed the blocksize in the dnode */
1398 if (db)
1399 dbuf_rele(db, FTAG);
1400
1401 rw_exit(&dn->dn_struct_rwlock);
1402 return (0);
1403
1404 fail:
1405 rw_exit(&dn->dn_struct_rwlock);
1406 return (SET_ERROR(ENOTSUP));
1407 }
1408
1409 /* read-holding callers must not rely on the lock being continuously held */
1410 void
1411 dnode_new_blkid(dnode_t *dn, uint64_t blkid, dmu_tx_t *tx, boolean_t have_read)
1412 {
1413 uint64_t txgoff = tx->tx_txg & TXG_MASK;
1414 int epbs, new_nlevels;
1415 uint64_t sz;
1416
1417 ASSERT(blkid != DMU_BONUS_BLKID);
1418
1419 ASSERT(have_read ?
1420 RW_READ_HELD(&dn->dn_struct_rwlock) :
1421 RW_WRITE_HELD(&dn->dn_struct_rwlock));
1422
1423 /*
1424 * if we have a read-lock, check to see if we need to do any work
1425 * before upgrading to a write-lock.
1426 */
1427 if (have_read) {
1428 if (blkid <= dn->dn_maxblkid)
1429 return;
1430
1431 if (!rw_tryupgrade(&dn->dn_struct_rwlock)) {
1432 rw_exit(&dn->dn_struct_rwlock);
1433 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
1434 }
1435 }
1436
1437 if (blkid <= dn->dn_maxblkid)
1438 goto out;
1439
1440 dn->dn_maxblkid = blkid;
1441
1442 /*
1443 * Compute the number of levels necessary to support the new maxblkid.
1444 */
1445 new_nlevels = 1;
1446 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT;
1447 for (sz = dn->dn_nblkptr;
1448 sz <= blkid && sz >= dn->dn_nblkptr; sz <<= epbs)
1449 new_nlevels++;
1450
1451 if (new_nlevels > dn->dn_nlevels) {
1452 int old_nlevels = dn->dn_nlevels;
1453 dmu_buf_impl_t *db;
1454 list_t *list;
1455 dbuf_dirty_record_t *new, *dr, *dr_next;
1456
1457 dn->dn_nlevels = new_nlevels;
1458
1459 ASSERT3U(new_nlevels, >, dn->dn_next_nlevels[txgoff]);
1460 dn->dn_next_nlevels[txgoff] = new_nlevels;
1461
1462 /* dirty the left indirects */
1463 db = dbuf_hold_level(dn, old_nlevels, 0, FTAG);
1464 ASSERT(db != NULL);
1465 new = dbuf_dirty(db, tx, B_FALSE);
1466 dbuf_rele(db, FTAG);
1467
1468 /* transfer the dirty records to the new indirect */
1469 mutex_enter(&dn->dn_mtx);
1470 mutex_enter(&new->dt.di.dr_mtx);
1471 list = &dn->dn_dirty_records[txgoff];
1472 for (dr = list_head(list); dr; dr = dr_next) {
1473 dr_next = list_next(&dn->dn_dirty_records[txgoff], dr);
1474 if (dr->dr_dbuf->db_level != new_nlevels-1 &&
1475 dr->dr_dbuf->db_blkid != DMU_BONUS_BLKID &&
1476 dr->dr_dbuf->db_blkid != DMU_SPILL_BLKID) {
1477 ASSERT(dr->dr_dbuf->db_level == old_nlevels-1);
1478 list_remove(&dn->dn_dirty_records[txgoff], dr);
1479 list_insert_tail(&new->dt.di.dr_children, dr);
1480 dr->dr_parent = new;
1481 }
1482 }
1483 mutex_exit(&new->dt.di.dr_mtx);
1484 mutex_exit(&dn->dn_mtx);
1485 }
1486
1487 out:
1488 if (have_read)
1489 rw_downgrade(&dn->dn_struct_rwlock);
1490 }
1491
1492 void
1493 dnode_free_range(dnode_t *dn, uint64_t off, uint64_t len, dmu_tx_t *tx)
1494 {
1495 dmu_buf_impl_t *db;
1496 uint64_t blkoff, blkid, nblks;
1497 int blksz, blkshift, head, tail;
1498 int trunc = FALSE;
1499 int epbs;
1500
1501 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
1502 blksz = dn->dn_datablksz;
1503 blkshift = dn->dn_datablkshift;
1504 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT;
1505
1506 if (len == DMU_OBJECT_END) {
1507 len = UINT64_MAX - off;
1508 trunc = TRUE;
1509 }
1510
1511 /*
1512 * First, block align the region to free:
1513 */
1514 if (ISP2(blksz)) {
1515 head = P2NPHASE(off, blksz);
1516 blkoff = P2PHASE(off, blksz);
1517 if ((off >> blkshift) > dn->dn_maxblkid)
1518 goto out;
1519 } else {
1520 ASSERT(dn->dn_maxblkid == 0);
1521 if (off == 0 && len >= blksz) {
1522 /*
1523 * Freeing the whole block; fast-track this request.
1524 * Note that we won't dirty any indirect blocks,
1525 * which is fine because we will be freeing the entire
1526 * file and thus all indirect blocks will be freed
1527 * by free_children().
1528 */
1529 blkid = 0;
1530 nblks = 1;
1531 goto done;
1532 } else if (off >= blksz) {
1533 /* Freeing past end-of-data */
1534 goto out;
1535 } else {
1536 /* Freeing part of the block. */
1537 head = blksz - off;
1538 ASSERT3U(head, >, 0);
1539 }
1540 blkoff = off;
1541 }
1542 /* zero out any partial block data at the start of the range */
1543 if (head) {
1544 ASSERT3U(blkoff + head, ==, blksz);
1545 if (len < head)
1546 head = len;
1547 if (dbuf_hold_impl(dn, 0, dbuf_whichblock(dn, off), TRUE,
1548 FTAG, &db) == 0) {
1549 caddr_t data;
1550
1551 /* don't dirty if it isn't on disk and isn't dirty */
1552 if (db->db_last_dirty ||
1553 (db->db_blkptr && !BP_IS_HOLE(db->db_blkptr))) {
1554 rw_exit(&dn->dn_struct_rwlock);
1555 dmu_buf_will_dirty(&db->db, tx);
1556 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
1557 data = db->db.db_data;
1558 bzero(data + blkoff, head);
1559 }
1560 dbuf_rele(db, FTAG);
1561 }
1562 off += head;
1563 len -= head;
1564 }
1565
1566 /* If the range was less than one block, we're done */
1567 if (len == 0)
1568 goto out;
1569
1570 /* If the remaining range is past end of file, we're done */
1571 if ((off >> blkshift) > dn->dn_maxblkid)
1572 goto out;
1573
1574 ASSERT(ISP2(blksz));
1575 if (trunc)
1576 tail = 0;
1577 else
1578 tail = P2PHASE(len, blksz);
1579
1580 ASSERT0(P2PHASE(off, blksz));
1581 /* zero out any partial block data at the end of the range */
1582 if (tail) {
1583 if (len < tail)
1584 tail = len;
1585 if (dbuf_hold_impl(dn, 0, dbuf_whichblock(dn, off+len),
1586 TRUE, FTAG, &db) == 0) {
1587 /* don't dirty if not on disk and not dirty */
1588 if (db->db_last_dirty ||
1589 (db->db_blkptr && !BP_IS_HOLE(db->db_blkptr))) {
1590 rw_exit(&dn->dn_struct_rwlock);
1591 dmu_buf_will_dirty(&db->db, tx);
1592 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
1593 bzero(db->db.db_data, tail);
1594 }
1595 dbuf_rele(db, FTAG);
1596 }
1597 len -= tail;
1598 }
1599
1600 /* If the range did not include a full block, we are done */
1601 if (len == 0)
1602 goto out;
1603
1604 ASSERT(IS_P2ALIGNED(off, blksz));
1605 ASSERT(trunc || IS_P2ALIGNED(len, blksz));
1606 blkid = off >> blkshift;
1607 nblks = len >> blkshift;
1608 if (trunc)
1609 nblks += 1;
1610
1611 /*
1612 * Dirty the first and last indirect blocks, as they (and/or their
1613 * parents) will need to be written out if they were only
1614 * partially freed. Interior indirect blocks will be themselves freed,
1615 * by free_children(), so they need not be dirtied. Note that these
1616 * interior blocks have already been prefetched by dmu_tx_hold_free().
1617 */
1618 if (dn->dn_nlevels > 1) {
1619 uint64_t first, last;
1620
1621 first = blkid >> epbs;
1622 if (db = dbuf_hold_level(dn, 1, first, FTAG)) {
1623 dmu_buf_will_dirty(&db->db, tx);
1624 dbuf_rele(db, FTAG);
1625 }
1626 if (trunc)
1627 last = dn->dn_maxblkid >> epbs;
1628 else
1629 last = (blkid + nblks - 1) >> epbs;
1630 if (last > first && (db = dbuf_hold_level(dn, 1, last, FTAG))) {
1631 dmu_buf_will_dirty(&db->db, tx);
1632 dbuf_rele(db, FTAG);
1633 }
1634 }
1635
1636 done:
1637 /*
1638 * Add this range to the dnode range list.
1639 * We will finish up this free operation in the syncing phase.
1640 */
1641 mutex_enter(&dn->dn_mtx);
1642 int txgoff = tx->tx_txg & TXG_MASK;
1643 if (dn->dn_free_ranges[txgoff] == NULL) {
1644 dn->dn_free_ranges[txgoff] =
1645 range_tree_create(NULL, NULL, &dn->dn_mtx);
1646 }
1647 range_tree_clear(dn->dn_free_ranges[txgoff], blkid, nblks);
1648 range_tree_add(dn->dn_free_ranges[txgoff], blkid, nblks);
1649 dprintf_dnode(dn, "blkid=%llu nblks=%llu txg=%llu\n",
1650 blkid, nblks, tx->tx_txg);
1651 mutex_exit(&dn->dn_mtx);
1652
1653 dbuf_free_range(dn, blkid, blkid + nblks - 1, tx);
1654 dnode_setdirty(dn, tx);
1655 out:
1656
1657 rw_exit(&dn->dn_struct_rwlock);
1658 }
1659
1660 static boolean_t
1661 dnode_spill_freed(dnode_t *dn)
1662 {
1663 int i;
1664
1665 mutex_enter(&dn->dn_mtx);
1666 for (i = 0; i < TXG_SIZE; i++) {
1667 if (dn->dn_rm_spillblk[i] == DN_KILL_SPILLBLK)
1668 break;
1669 }
1670 mutex_exit(&dn->dn_mtx);
1671 return (i < TXG_SIZE);
1672 }
1673
1674 /* return TRUE if this blkid was freed in a recent txg, or FALSE if it wasn't */
1675 uint64_t
1676 dnode_block_freed(dnode_t *dn, uint64_t blkid)
1677 {
1678 void *dp = spa_get_dsl(dn->dn_objset->os_spa);
1679 int i;
1680
1681 if (blkid == DMU_BONUS_BLKID)
1682 return (FALSE);
1683
1684 /*
1685 * If we're in the process of opening the pool, dp will not be
1686 * set yet, but there shouldn't be anything dirty.
1687 */
1688 if (dp == NULL)
1689 return (FALSE);
1690
1691 if (dn->dn_free_txg)
1692 return (TRUE);
1693
1694 if (blkid == DMU_SPILL_BLKID)
1695 return (dnode_spill_freed(dn));
1696
1697 mutex_enter(&dn->dn_mtx);
1698 for (i = 0; i < TXG_SIZE; i++) {
1699 if (dn->dn_free_ranges[i] != NULL &&
1700 range_tree_contains(dn->dn_free_ranges[i], blkid, 1))
1701 break;
1702 }
1703 mutex_exit(&dn->dn_mtx);
1704 return (i < TXG_SIZE);
1705 }
1706
1707 /* call from syncing context when we actually write/free space for this dnode */
1708 void
1709 dnode_diduse_space(dnode_t *dn, int64_t delta)
1710 {
1711 uint64_t space;
1712 dprintf_dnode(dn, "dn=%p dnp=%p used=%llu delta=%lld\n",
1713 dn, dn->dn_phys,
1714 (u_longlong_t)dn->dn_phys->dn_used,
1715 (longlong_t)delta);
1716
1717 mutex_enter(&dn->dn_mtx);
1718 space = DN_USED_BYTES(dn->dn_phys);
1719 if (delta > 0) {
1720 ASSERT3U(space + delta, >=, space); /* no overflow */
1721 } else {
1722 ASSERT3U(space, >=, -delta); /* no underflow */
1723 }
1724 space += delta;
1725 if (spa_version(dn->dn_objset->os_spa) < SPA_VERSION_DNODE_BYTES) {
1726 ASSERT((dn->dn_phys->dn_flags & DNODE_FLAG_USED_BYTES) == 0);
1727 ASSERT0(P2PHASE(space, 1<<DEV_BSHIFT));
1728 dn->dn_phys->dn_used = space >> DEV_BSHIFT;
1729 } else {
1730 dn->dn_phys->dn_used = space;
1731 dn->dn_phys->dn_flags |= DNODE_FLAG_USED_BYTES;
1732 }
1733 mutex_exit(&dn->dn_mtx);
1734 }
1735
1736 /*
1737 * Call when we think we're going to write/free space in open context to track
1738 * the amount of memory in use by the currently open txg.
1739 */
1740 void
1741 dnode_willuse_space(dnode_t *dn, int64_t space, dmu_tx_t *tx)
1742 {
1743 objset_t *os = dn->dn_objset;
1744 dsl_dataset_t *ds = os->os_dsl_dataset;
1745 int64_t aspace = spa_get_asize(os->os_spa, space);
1746
1747 if (ds != NULL) {
1748 dsl_dir_willuse_space(ds->ds_dir, aspace, tx);
1749 dsl_pool_dirty_space(dmu_tx_pool(tx), space, tx);
1750 }
1751
1752 dmu_tx_willuse_space(tx, aspace);
1753 }
1754
1755 /*
1756 * Scans a block at the indicated "level" looking for a hole or data,
1757 * depending on 'flags'.
1758 *
1759 * If level > 0, then we are scanning an indirect block looking at its
1760 * pointers. If level == 0, then we are looking at a block of dnodes.
1761 *
1762 * If we don't find what we are looking for in the block, we return ESRCH.
1763 * Otherwise, return with *offset pointing to the beginning (if searching
1764 * forwards) or end (if searching backwards) of the range covered by the
1765 * block pointer we matched on (or dnode).
1766 *
1767 * The basic search algorithm used below by dnode_next_offset() is to
1768 * use this function to search up the block tree (widen the search) until
1769 * we find something (i.e., we don't return ESRCH) and then search back
1770 * down the tree (narrow the search) until we reach our original search
1771 * level.
1772 */
1773 static int
1774 dnode_next_offset_level(dnode_t *dn, int flags, uint64_t *offset,
1775 int lvl, uint64_t blkfill, uint64_t txg)
1776 {
1777 dmu_buf_impl_t *db = NULL;
1778 void *data = NULL;
1779 uint64_t epbs = dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT;
1780 uint64_t epb = 1ULL << epbs;
1781 uint64_t minfill, maxfill;
1782 boolean_t hole;
1783 int i, inc, error, span;
1784
1785 dprintf("probing object %llu offset %llx level %d of %u\n",
1786 dn->dn_object, *offset, lvl, dn->dn_phys->dn_nlevels);
1787
1788 hole = ((flags & DNODE_FIND_HOLE) != 0);
1789 inc = (flags & DNODE_FIND_BACKWARDS) ? -1 : 1;
1790 ASSERT(txg == 0 || !hole);
1791
1792 if (lvl == dn->dn_phys->dn_nlevels) {
1793 error = 0;
1794 epb = dn->dn_phys->dn_nblkptr;
1795 data = dn->dn_phys->dn_blkptr;
1796 } else {
1797 uint64_t blkid = dbuf_whichblock(dn, *offset) >> (epbs * lvl);
1798 error = dbuf_hold_impl(dn, lvl, blkid, TRUE, FTAG, &db);
1799 if (error) {
1800 if (error != ENOENT)
1801 return (error);
1802 if (hole)
1803 return (0);
1804 /*
1805 * This can only happen when we are searching up
1806 * the block tree for data. We don't really need to
1807 * adjust the offset, as we will just end up looking
1808 * at the pointer to this block in its parent, and its
1809 * going to be unallocated, so we will skip over it.
1810 */
1811 return (SET_ERROR(ESRCH));
1812 }
1813 error = dbuf_read(db, NULL, DB_RF_CANFAIL | DB_RF_HAVESTRUCT);
1814 if (error) {
1815 dbuf_rele(db, FTAG);
1816 return (error);
1817 }
1818 data = db->db.db_data;
1819 }
1820
1821
1822 if (db != NULL && txg != 0 && (db->db_blkptr == NULL ||
1823 db->db_blkptr->blk_birth <= txg ||
1824 BP_IS_HOLE(db->db_blkptr))) {
1825 /*
1826 * This can only happen when we are searching up the tree
1827 * and these conditions mean that we need to keep climbing.
1828 */
1829 error = SET_ERROR(ESRCH);
1830 } else if (lvl == 0) {
1831 dnode_phys_t *dnp = data;
1832 span = DNODE_SHIFT;
1833 ASSERT(dn->dn_type == DMU_OT_DNODE);
1834
1835 for (i = (*offset >> span) & (blkfill - 1);
1836 i >= 0 && i < blkfill; i += inc) {
1837 if ((dnp[i].dn_type == DMU_OT_NONE) == hole)
1838 break;
1839 *offset += (1ULL << span) * inc;
1840 }
1841 if (i < 0 || i == blkfill)
1842 error = SET_ERROR(ESRCH);
1843 } else {
1844 blkptr_t *bp = data;
1845 uint64_t start = *offset;
1846 span = (lvl - 1) * epbs + dn->dn_datablkshift;
1847 minfill = 0;
1848 maxfill = blkfill << ((lvl - 1) * epbs);
1849
1850 if (hole)
1851 maxfill--;
1852 else
1853 minfill++;
1854
1855 *offset = *offset >> span;
1856 for (i = BF64_GET(*offset, 0, epbs);
1857 i >= 0 && i < epb; i += inc) {
1858 if (BP_GET_FILL(&bp[i]) >= minfill &&
1859 BP_GET_FILL(&bp[i]) <= maxfill &&
1860 (hole || bp[i].blk_birth > txg))
1861 break;
1862 if (inc > 0 || *offset > 0)
1863 *offset += inc;
1864 }
1865 *offset = *offset << span;
1866 if (inc < 0) {
1867 /* traversing backwards; position offset at the end */
1868 ASSERT3U(*offset, <=, start);
1869 *offset = MIN(*offset + (1ULL << span) - 1, start);
1870 } else if (*offset < start) {
1871 *offset = start;
1872 }
1873 if (i < 0 || i >= epb)
1874 error = SET_ERROR(ESRCH);
1875 }
1876
1877 if (db)
1878 dbuf_rele(db, FTAG);
1879
1880 return (error);
1881 }
1882
1883 /*
1884 * Find the next hole, data, or sparse region at or after *offset.
1885 * The value 'blkfill' tells us how many items we expect to find
1886 * in an L0 data block; this value is 1 for normal objects,
1887 * DNODES_PER_BLOCK for the meta dnode, and some fraction of
1888 * DNODES_PER_BLOCK when searching for sparse regions thereof.
1889 *
1890 * Examples:
1891 *
1892 * dnode_next_offset(dn, flags, offset, 1, 1, 0);
1893 * Finds the next/previous hole/data in a file.
1894 * Used in dmu_offset_next().
1895 *
1896 * dnode_next_offset(mdn, flags, offset, 0, DNODES_PER_BLOCK, txg);
1897 * Finds the next free/allocated dnode an objset's meta-dnode.
1898 * Only finds objects that have new contents since txg (ie.
1899 * bonus buffer changes and content removal are ignored).
1900 * Used in dmu_object_next().
1901 *
1902 * dnode_next_offset(mdn, DNODE_FIND_HOLE, offset, 2, DNODES_PER_BLOCK >> 2, 0);
1903 * Finds the next L2 meta-dnode bp that's at most 1/4 full.
1904 * Used in dmu_object_alloc().
1905 */
1906 int
1907 dnode_next_offset(dnode_t *dn, int flags, uint64_t *offset,
1908 int minlvl, uint64_t blkfill, uint64_t txg)
1909 {
1910 uint64_t initial_offset = *offset;
1911 int lvl, maxlvl;
1912 int error = 0;
1913
1914 if (!(flags & DNODE_FIND_HAVELOCK))
1915 rw_enter(&dn->dn_struct_rwlock, RW_READER);
1916
1917 if (dn->dn_phys->dn_nlevels == 0) {
1918 error = SET_ERROR(ESRCH);
1919 goto out;
1920 }
1921
1922 if (dn->dn_datablkshift == 0) {
1923 if (*offset < dn->dn_datablksz) {
1924 if (flags & DNODE_FIND_HOLE)
1925 *offset = dn->dn_datablksz;
1926 } else {
1927 error = SET_ERROR(ESRCH);
1928 }
1929 goto out;
1930 }
1931
1932 maxlvl = dn->dn_phys->dn_nlevels;
1933
1934 for (lvl = minlvl; lvl <= maxlvl; lvl++) {
1935 error = dnode_next_offset_level(dn,
1936 flags, offset, lvl, blkfill, txg);
1937 if (error != ESRCH)
1938 break;
1939 }
1940
1941 while (error == 0 && --lvl >= minlvl) {
1942 error = dnode_next_offset_level(dn,
1943 flags, offset, lvl, blkfill, txg);
1944 }
1945
1946 /*
1947 * There's always a "virtual hole" at the end of the object, even
1948 * if all BP's which physically exist are non-holes.
1949 */
1950 if ((flags & DNODE_FIND_HOLE) && error == ESRCH && txg == 0 &&
1951 minlvl == 1 && blkfill == 1 && !(flags & DNODE_FIND_BACKWARDS)) {
1952 error = 0;
1953 }
1954
1955 if (error == 0 && (flags & DNODE_FIND_BACKWARDS ?
1956 initial_offset < *offset : initial_offset > *offset))
1957 error = SET_ERROR(ESRCH);
1958 out:
1959 if (!(flags & DNODE_FIND_HAVELOCK))
1960 rw_exit(&dn->dn_struct_rwlock);
1961
1962 return (error);
1963 }