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) 2013 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
39 static int free_range_compar(const void *node1, const void *node2);
40
41 static kmem_cache_t *dnode_cache;
42 /*
43 * Define DNODE_STATS to turn on statistic gathering. By default, it is only
44 * turned on when DEBUG is also defined.
45 */
46 #ifdef DEBUG
47 #define DNODE_STATS
48 #endif /* DEBUG */
49
50 #ifdef DNODE_STATS
51 #define DNODE_STAT_ADD(stat) ((stat)++)
52 #else
53 #define DNODE_STAT_ADD(stat) /* nothing */
54 #endif /* DNODE_STATS */
55
56 static dnode_phys_t dnode_phys_zero;
57
58 int zfs_default_bs = SPA_MINBLOCKSHIFT;
59 int zfs_default_ibs = DN_MAX_INDBLKSHIFT;
60
61 static kmem_cbrc_t dnode_move(void *, void *, size_t, void *);
62
63 /* ARGSUSED */
64 static int
65 dnode_cons(void *arg, void *unused, int kmflag)
66 {
67 dnode_t *dn = arg;
68 int i;
69
70 rw_init(&dn->dn_struct_rwlock, NULL, RW_DEFAULT, NULL);
71 mutex_init(&dn->dn_mtx, NULL, MUTEX_DEFAULT, NULL);
72 mutex_init(&dn->dn_dbufs_mtx, NULL, MUTEX_DEFAULT, NULL);
73 cv_init(&dn->dn_notxholds, NULL, CV_DEFAULT, NULL);
74
75 /*
76 * Every dbuf has a reference, and dropping a tracked reference is
77 * O(number of references), so don't track dn_holds.
78 */
79 refcount_create_untracked(&dn->dn_holds);
80 refcount_create(&dn->dn_tx_holds);
81 list_link_init(&dn->dn_link);
82
83 bzero(&dn->dn_next_nblkptr[0], sizeof (dn->dn_next_nblkptr));
84 bzero(&dn->dn_next_nlevels[0], sizeof (dn->dn_next_nlevels));
85 bzero(&dn->dn_next_indblkshift[0], sizeof (dn->dn_next_indblkshift));
86 bzero(&dn->dn_next_bonustype[0], sizeof (dn->dn_next_bonustype));
87 bzero(&dn->dn_rm_spillblk[0], sizeof (dn->dn_rm_spillblk));
88 bzero(&dn->dn_next_bonuslen[0], sizeof (dn->dn_next_bonuslen));
89 bzero(&dn->dn_next_blksz[0], sizeof (dn->dn_next_blksz));
90
91 for (i = 0; i < TXG_SIZE; i++) {
92 list_link_init(&dn->dn_dirty_link[i]);
93 avl_create(&dn->dn_ranges[i], free_range_compar,
94 sizeof (free_range_t),
95 offsetof(struct free_range, fr_node));
96 list_create(&dn->dn_dirty_records[i],
97 sizeof (dbuf_dirty_record_t),
98 offsetof(dbuf_dirty_record_t, dr_dirty_node));
99 }
100
101 dn->dn_allocated_txg = 0;
102 dn->dn_free_txg = 0;
103 dn->dn_assigned_txg = 0;
104 dn->dn_dirtyctx = 0;
105 dn->dn_dirtyctx_firstset = NULL;
106 dn->dn_bonus = NULL;
107 dn->dn_have_spill = B_FALSE;
108 dn->dn_zio = NULL;
109 dn->dn_oldused = 0;
110 dn->dn_oldflags = 0;
111 dn->dn_olduid = 0;
112 dn->dn_oldgid = 0;
113 dn->dn_newuid = 0;
114 dn->dn_newgid = 0;
115 dn->dn_id_flags = 0;
116
117 dn->dn_dbufs_count = 0;
118 list_create(&dn->dn_dbufs, sizeof (dmu_buf_impl_t),
119 offsetof(dmu_buf_impl_t, db_link));
120
121 dn->dn_moved = 0;
122 return (0);
123 }
124
125 /* ARGSUSED */
126 static void
127 dnode_dest(void *arg, void *unused)
128 {
129 int i;
130 dnode_t *dn = arg;
131
132 rw_destroy(&dn->dn_struct_rwlock);
133 mutex_destroy(&dn->dn_mtx);
134 mutex_destroy(&dn->dn_dbufs_mtx);
135 cv_destroy(&dn->dn_notxholds);
136 refcount_destroy(&dn->dn_holds);
137 refcount_destroy(&dn->dn_tx_holds);
138 ASSERT(!list_link_active(&dn->dn_link));
139
140 for (i = 0; i < TXG_SIZE; i++) {
141 ASSERT(!list_link_active(&dn->dn_dirty_link[i]));
142 avl_destroy(&dn->dn_ranges[i]);
143 list_destroy(&dn->dn_dirty_records[i]);
144 ASSERT0(dn->dn_next_nblkptr[i]);
145 ASSERT0(dn->dn_next_nlevels[i]);
146 ASSERT0(dn->dn_next_indblkshift[i]);
147 ASSERT0(dn->dn_next_bonustype[i]);
148 ASSERT0(dn->dn_rm_spillblk[i]);
149 ASSERT0(dn->dn_next_bonuslen[i]);
150 ASSERT0(dn->dn_next_blksz[i]);
151 }
152
153 ASSERT0(dn->dn_allocated_txg);
154 ASSERT0(dn->dn_free_txg);
155 ASSERT0(dn->dn_assigned_txg);
156 ASSERT0(dn->dn_dirtyctx);
157 ASSERT3P(dn->dn_dirtyctx_firstset, ==, NULL);
158 ASSERT3P(dn->dn_bonus, ==, NULL);
159 ASSERT(!dn->dn_have_spill);
160 ASSERT3P(dn->dn_zio, ==, NULL);
161 ASSERT0(dn->dn_oldused);
162 ASSERT0(dn->dn_oldflags);
163 ASSERT0(dn->dn_olduid);
164 ASSERT0(dn->dn_oldgid);
165 ASSERT0(dn->dn_newuid);
166 ASSERT0(dn->dn_newgid);
167 ASSERT0(dn->dn_id_flags);
168
169 ASSERT0(dn->dn_dbufs_count);
170 list_destroy(&dn->dn_dbufs);
171 }
172
173 void
174 dnode_init(void)
175 {
176 ASSERT(dnode_cache == NULL);
177 dnode_cache = kmem_cache_create("dnode_t",
178 sizeof (dnode_t),
179 0, dnode_cons, dnode_dest, NULL, NULL, NULL, 0);
180 kmem_cache_set_move(dnode_cache, dnode_move);
181 }
182
183 void
184 dnode_fini(void)
185 {
186 kmem_cache_destroy(dnode_cache);
187 dnode_cache = NULL;
188 }
189
190
191 #ifdef ZFS_DEBUG
192 void
193 dnode_verify(dnode_t *dn)
194 {
195 int drop_struct_lock = FALSE;
196
197 ASSERT(dn->dn_phys);
198 ASSERT(dn->dn_objset);
199 ASSERT(dn->dn_handle->dnh_dnode == dn);
200
201 ASSERT(DMU_OT_IS_VALID(dn->dn_phys->dn_type));
202
203 if (!(zfs_flags & ZFS_DEBUG_DNODE_VERIFY))
204 return;
205
206 if (!RW_WRITE_HELD(&dn->dn_struct_rwlock)) {
207 rw_enter(&dn->dn_struct_rwlock, RW_READER);
208 drop_struct_lock = TRUE;
209 }
210 if (dn->dn_phys->dn_type != DMU_OT_NONE || dn->dn_allocated_txg != 0) {
211 int i;
212 ASSERT3U(dn->dn_indblkshift, >=, 0);
213 ASSERT3U(dn->dn_indblkshift, <=, SPA_MAXBLOCKSHIFT);
214 if (dn->dn_datablkshift) {
215 ASSERT3U(dn->dn_datablkshift, >=, SPA_MINBLOCKSHIFT);
216 ASSERT3U(dn->dn_datablkshift, <=, SPA_MAXBLOCKSHIFT);
217 ASSERT3U(1<<dn->dn_datablkshift, ==, dn->dn_datablksz);
218 }
219 ASSERT3U(dn->dn_nlevels, <=, 30);
220 ASSERT(DMU_OT_IS_VALID(dn->dn_type));
221 ASSERT3U(dn->dn_nblkptr, >=, 1);
222 ASSERT3U(dn->dn_nblkptr, <=, DN_MAX_NBLKPTR);
223 ASSERT3U(dn->dn_bonuslen, <=, DN_MAX_BONUSLEN);
224 ASSERT3U(dn->dn_datablksz, ==,
225 dn->dn_datablkszsec << SPA_MINBLOCKSHIFT);
226 ASSERT3U(ISP2(dn->dn_datablksz), ==, dn->dn_datablkshift != 0);
227 ASSERT3U((dn->dn_nblkptr - 1) * sizeof (blkptr_t) +
228 dn->dn_bonuslen, <=, DN_MAX_BONUSLEN);
229 for (i = 0; i < TXG_SIZE; i++) {
230 ASSERT3U(dn->dn_next_nlevels[i], <=, dn->dn_nlevels);
231 }
232 }
233 if (dn->dn_phys->dn_type != DMU_OT_NONE)
234 ASSERT3U(dn->dn_phys->dn_nlevels, <=, dn->dn_nlevels);
235 ASSERT(DMU_OBJECT_IS_SPECIAL(dn->dn_object) || dn->dn_dbuf != NULL);
236 if (dn->dn_dbuf != NULL) {
237 ASSERT3P(dn->dn_phys, ==,
238 (dnode_phys_t *)dn->dn_dbuf->db.db_data +
239 (dn->dn_object % (dn->dn_dbuf->db.db_size >> DNODE_SHIFT)));
240 }
241 if (drop_struct_lock)
242 rw_exit(&dn->dn_struct_rwlock);
243 }
244 #endif
245
246 void
247 dnode_byteswap(dnode_phys_t *dnp)
248 {
249 uint64_t *buf64 = (void*)&dnp->dn_blkptr;
250 int i;
251
252 if (dnp->dn_type == DMU_OT_NONE) {
253 bzero(dnp, sizeof (dnode_phys_t));
254 return;
255 }
256
257 dnp->dn_datablkszsec = BSWAP_16(dnp->dn_datablkszsec);
258 dnp->dn_bonuslen = BSWAP_16(dnp->dn_bonuslen);
259 dnp->dn_maxblkid = BSWAP_64(dnp->dn_maxblkid);
260 dnp->dn_used = BSWAP_64(dnp->dn_used);
261
262 /*
263 * dn_nblkptr is only one byte, so it's OK to read it in either
264 * byte order. We can't read dn_bouslen.
265 */
266 ASSERT(dnp->dn_indblkshift <= SPA_MAXBLOCKSHIFT);
267 ASSERT(dnp->dn_nblkptr <= DN_MAX_NBLKPTR);
268 for (i = 0; i < dnp->dn_nblkptr * sizeof (blkptr_t)/8; i++)
269 buf64[i] = BSWAP_64(buf64[i]);
270
271 /*
272 * OK to check dn_bonuslen for zero, because it won't matter if
273 * we have the wrong byte order. This is necessary because the
274 * dnode dnode is smaller than a regular dnode.
275 */
276 if (dnp->dn_bonuslen != 0) {
277 /*
278 * Note that the bonus length calculated here may be
279 * longer than the actual bonus buffer. This is because
280 * we always put the bonus buffer after the last block
281 * pointer (instead of packing it against the end of the
282 * dnode buffer).
283 */
284 int off = (dnp->dn_nblkptr-1) * sizeof (blkptr_t);
285 size_t len = DN_MAX_BONUSLEN - off;
286 ASSERT(DMU_OT_IS_VALID(dnp->dn_bonustype));
287 dmu_object_byteswap_t byteswap =
288 DMU_OT_BYTESWAP(dnp->dn_bonustype);
289 dmu_ot_byteswap[byteswap].ob_func(dnp->dn_bonus + off, len);
290 }
291
292 /* Swap SPILL block if we have one */
293 if (dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR)
294 byteswap_uint64_array(&dnp->dn_spill, sizeof (blkptr_t));
295
296 }
297
298 void
299 dnode_buf_byteswap(void *vbuf, size_t size)
300 {
301 dnode_phys_t *buf = vbuf;
302 int i;
303
304 ASSERT3U(sizeof (dnode_phys_t), ==, (1<<DNODE_SHIFT));
305 ASSERT((size & (sizeof (dnode_phys_t)-1)) == 0);
306
307 size >>= DNODE_SHIFT;
308 for (i = 0; i < size; i++) {
309 dnode_byteswap(buf);
310 buf++;
311 }
312 }
313
314 static int
315 free_range_compar(const void *node1, const void *node2)
316 {
317 const free_range_t *rp1 = node1;
318 const free_range_t *rp2 = node2;
319
320 if (rp1->fr_blkid < rp2->fr_blkid)
321 return (-1);
322 else if (rp1->fr_blkid > rp2->fr_blkid)
323 return (1);
324 else return (0);
325 }
326
327 void
328 dnode_setbonuslen(dnode_t *dn, int newsize, dmu_tx_t *tx)
329 {
330 ASSERT3U(refcount_count(&dn->dn_holds), >=, 1);
331
332 dnode_setdirty(dn, tx);
333 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
334 ASSERT3U(newsize, <=, DN_MAX_BONUSLEN -
335 (dn->dn_nblkptr-1) * sizeof (blkptr_t));
336 dn->dn_bonuslen = newsize;
337 if (newsize == 0)
338 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = DN_ZERO_BONUSLEN;
339 else
340 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = dn->dn_bonuslen;
341 rw_exit(&dn->dn_struct_rwlock);
342 }
343
344 void
345 dnode_setbonus_type(dnode_t *dn, dmu_object_type_t newtype, dmu_tx_t *tx)
346 {
347 ASSERT3U(refcount_count(&dn->dn_holds), >=, 1);
348 dnode_setdirty(dn, tx);
349 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
350 dn->dn_bonustype = newtype;
351 dn->dn_next_bonustype[tx->tx_txg & TXG_MASK] = dn->dn_bonustype;
352 rw_exit(&dn->dn_struct_rwlock);
353 }
354
355 void
356 dnode_rm_spill(dnode_t *dn, dmu_tx_t *tx)
357 {
358 ASSERT3U(refcount_count(&dn->dn_holds), >=, 1);
359 ASSERT(RW_WRITE_HELD(&dn->dn_struct_rwlock));
360 dnode_setdirty(dn, tx);
361 dn->dn_rm_spillblk[tx->tx_txg&TXG_MASK] = DN_KILL_SPILLBLK;
362 dn->dn_have_spill = B_FALSE;
363 }
364
365 static void
366 dnode_setdblksz(dnode_t *dn, int size)
367 {
368 ASSERT0(P2PHASE(size, SPA_MINBLOCKSIZE));
369 ASSERT3U(size, <=, SPA_MAXBLOCKSIZE);
370 ASSERT3U(size, >=, SPA_MINBLOCKSIZE);
371 ASSERT3U(size >> SPA_MINBLOCKSHIFT, <,
372 1<<(sizeof (dn->dn_phys->dn_datablkszsec) * 8));
373 dn->dn_datablksz = size;
374 dn->dn_datablkszsec = size >> SPA_MINBLOCKSHIFT;
375 dn->dn_datablkshift = ISP2(size) ? highbit(size - 1) : 0;
376 }
377
378 static dnode_t *
379 dnode_create(objset_t *os, dnode_phys_t *dnp, dmu_buf_impl_t *db,
380 uint64_t object, dnode_handle_t *dnh)
381 {
382 dnode_t *dn = kmem_cache_alloc(dnode_cache, KM_SLEEP);
383
384 ASSERT(!POINTER_IS_VALID(dn->dn_objset));
385 dn->dn_moved = 0;
386
387 /*
388 * Defer setting dn_objset until the dnode is ready to be a candidate
389 * for the dnode_move() callback.
390 */
391 dn->dn_object = object;
392 dn->dn_dbuf = db;
393 dn->dn_handle = dnh;
394 dn->dn_phys = dnp;
395
396 if (dnp->dn_datablkszsec) {
397 dnode_setdblksz(dn, dnp->dn_datablkszsec << SPA_MINBLOCKSHIFT);
398 } else {
399 dn->dn_datablksz = 0;
400 dn->dn_datablkszsec = 0;
401 dn->dn_datablkshift = 0;
402 }
403 dn->dn_indblkshift = dnp->dn_indblkshift;
404 dn->dn_nlevels = dnp->dn_nlevels;
405 dn->dn_type = dnp->dn_type;
406 dn->dn_nblkptr = dnp->dn_nblkptr;
407 dn->dn_checksum = dnp->dn_checksum;
408 dn->dn_compress = dnp->dn_compress;
409 dn->dn_bonustype = dnp->dn_bonustype;
410 dn->dn_bonuslen = dnp->dn_bonuslen;
411 dn->dn_maxblkid = dnp->dn_maxblkid;
412 dn->dn_have_spill = ((dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) != 0);
413 dn->dn_id_flags = 0;
414
415 dmu_zfetch_init(&dn->dn_zfetch, dn);
416
417 ASSERT(DMU_OT_IS_VALID(dn->dn_phys->dn_type));
418
419 mutex_enter(&os->os_lock);
420 list_insert_head(&os->os_dnodes, dn);
421 membar_producer();
422 /*
423 * Everything else must be valid before assigning dn_objset makes the
424 * dnode eligible for dnode_move().
425 */
426 dn->dn_objset = os;
427 mutex_exit(&os->os_lock);
428
429 arc_space_consume(sizeof (dnode_t), ARC_SPACE_OTHER);
430 return (dn);
431 }
432
433 /*
434 * Caller must be holding the dnode handle, which is released upon return.
435 */
436 static void
437 dnode_destroy(dnode_t *dn)
438 {
439 objset_t *os = dn->dn_objset;
440
441 ASSERT((dn->dn_id_flags & DN_ID_NEW_EXIST) == 0);
442
443 mutex_enter(&os->os_lock);
444 POINTER_INVALIDATE(&dn->dn_objset);
445 list_remove(&os->os_dnodes, dn);
446 mutex_exit(&os->os_lock);
447
448 /* the dnode can no longer move, so we can release the handle */
449 zrl_remove(&dn->dn_handle->dnh_zrlock);
450
451 dn->dn_allocated_txg = 0;
452 dn->dn_free_txg = 0;
453 dn->dn_assigned_txg = 0;
454
455 dn->dn_dirtyctx = 0;
456 if (dn->dn_dirtyctx_firstset != NULL) {
457 kmem_free(dn->dn_dirtyctx_firstset, 1);
458 dn->dn_dirtyctx_firstset = NULL;
459 }
460 if (dn->dn_bonus != NULL) {
461 list_t evict_list;
462
463 dmu_buf_create_user_evict_list(&evict_list);
464 mutex_enter(&dn->dn_bonus->db_mtx);
465 dbuf_evict(dn->dn_bonus, &evict_list);
466 dmu_buf_destroy_user_evict_list(&evict_list);
467 dn->dn_bonus = NULL;
468 }
469 dn->dn_zio = NULL;
470
471 dn->dn_have_spill = B_FALSE;
472 dn->dn_oldused = 0;
473 dn->dn_oldflags = 0;
474 dn->dn_olduid = 0;
475 dn->dn_oldgid = 0;
476 dn->dn_newuid = 0;
477 dn->dn_newgid = 0;
478 dn->dn_id_flags = 0;
479
480 dmu_zfetch_rele(&dn->dn_zfetch);
481 kmem_cache_free(dnode_cache, dn);
482 arc_space_return(sizeof (dnode_t), ARC_SPACE_OTHER);
483 }
484
485 void
486 dnode_allocate(dnode_t *dn, dmu_object_type_t ot, int blocksize, int ibs,
487 dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx)
488 {
489 int i;
490
491 if (blocksize == 0)
492 blocksize = 1 << zfs_default_bs;
493 else if (blocksize > SPA_MAXBLOCKSIZE)
494 blocksize = SPA_MAXBLOCKSIZE;
495 else
496 blocksize = P2ROUNDUP(blocksize, SPA_MINBLOCKSIZE);
497
498 if (ibs == 0)
499 ibs = zfs_default_ibs;
500
501 ibs = MIN(MAX(ibs, DN_MIN_INDBLKSHIFT), DN_MAX_INDBLKSHIFT);
502
503 dprintf("os=%p obj=%llu txg=%llu blocksize=%d ibs=%d\n", dn->dn_objset,
504 dn->dn_object, tx->tx_txg, blocksize, ibs);
505
506 ASSERT(dn->dn_type == DMU_OT_NONE);
507 ASSERT(bcmp(dn->dn_phys, &dnode_phys_zero, sizeof (dnode_phys_t)) == 0);
508 ASSERT(dn->dn_phys->dn_type == DMU_OT_NONE);
509 ASSERT(ot != DMU_OT_NONE);
510 ASSERT(DMU_OT_IS_VALID(ot));
511 ASSERT((bonustype == DMU_OT_NONE && bonuslen == 0) ||
512 (bonustype == DMU_OT_SA && bonuslen == 0) ||
513 (bonustype != DMU_OT_NONE && bonuslen != 0));
514 ASSERT(DMU_OT_IS_VALID(bonustype));
515 ASSERT3U(bonuslen, <=, DN_MAX_BONUSLEN);
516 ASSERT(dn->dn_type == DMU_OT_NONE);
517 ASSERT0(dn->dn_maxblkid);
518 ASSERT0(dn->dn_allocated_txg);
519 ASSERT0(dn->dn_assigned_txg);
520 ASSERT(refcount_is_zero(&dn->dn_tx_holds));
521 ASSERT3U(refcount_count(&dn->dn_holds), <=, 1);
522 ASSERT3P(list_head(&dn->dn_dbufs), ==, NULL);
523
524 for (i = 0; i < TXG_SIZE; i++) {
525 ASSERT0(dn->dn_next_nblkptr[i]);
526 ASSERT0(dn->dn_next_nlevels[i]);
527 ASSERT0(dn->dn_next_indblkshift[i]);
528 ASSERT0(dn->dn_next_bonuslen[i]);
529 ASSERT0(dn->dn_next_bonustype[i]);
530 ASSERT0(dn->dn_rm_spillblk[i]);
531 ASSERT0(dn->dn_next_blksz[i]);
532 ASSERT(!list_link_active(&dn->dn_dirty_link[i]));
533 ASSERT3P(list_head(&dn->dn_dirty_records[i]), ==, NULL);
534 ASSERT0(avl_numnodes(&dn->dn_ranges[i]));
535 }
536
537 dn->dn_type = ot;
538 dnode_setdblksz(dn, blocksize);
539 dn->dn_indblkshift = ibs;
540 dn->dn_nlevels = 1;
541 if (bonustype == DMU_OT_SA) /* Maximize bonus space for SA */
542 dn->dn_nblkptr = 1;
543 else
544 dn->dn_nblkptr = 1 +
545 ((DN_MAX_BONUSLEN - bonuslen) >> SPA_BLKPTRSHIFT);
546 dn->dn_bonustype = bonustype;
547 dn->dn_bonuslen = bonuslen;
548 dn->dn_checksum = ZIO_CHECKSUM_INHERIT;
549 dn->dn_compress = ZIO_COMPRESS_INHERIT;
550 dn->dn_dirtyctx = 0;
551
552 dn->dn_free_txg = 0;
553 if (dn->dn_dirtyctx_firstset) {
554 kmem_free(dn->dn_dirtyctx_firstset, 1);
555 dn->dn_dirtyctx_firstset = NULL;
556 }
557
558 dn->dn_allocated_txg = tx->tx_txg;
559 dn->dn_id_flags = 0;
560
561 dnode_setdirty(dn, tx);
562 dn->dn_next_indblkshift[tx->tx_txg & TXG_MASK] = ibs;
563 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = dn->dn_bonuslen;
564 dn->dn_next_bonustype[tx->tx_txg & TXG_MASK] = dn->dn_bonustype;
565 dn->dn_next_blksz[tx->tx_txg & TXG_MASK] = dn->dn_datablksz;
566 }
567
568 void
569 dnode_reallocate(dnode_t *dn, dmu_object_type_t ot, int blocksize,
570 dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx)
571 {
572 int nblkptr;
573
574 ASSERT3U(blocksize, >=, SPA_MINBLOCKSIZE);
575 ASSERT3U(blocksize, <=, SPA_MAXBLOCKSIZE);
576 ASSERT0(blocksize % SPA_MINBLOCKSIZE);
577 ASSERT(dn->dn_object != DMU_META_DNODE_OBJECT || dmu_tx_private_ok(tx));
578 ASSERT(tx->tx_txg != 0);
579 ASSERT((bonustype == DMU_OT_NONE && bonuslen == 0) ||
580 (bonustype != DMU_OT_NONE && bonuslen != 0) ||
581 (bonustype == DMU_OT_SA && bonuslen == 0));
582 ASSERT(DMU_OT_IS_VALID(bonustype));
583 ASSERT3U(bonuslen, <=, DN_MAX_BONUSLEN);
584
585 /* clean up any unreferenced dbufs */
586 dnode_evict_dbufs(dn);
587
588 dn->dn_id_flags = 0;
589
590 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
591 dnode_setdirty(dn, tx);
592 if (dn->dn_datablksz != blocksize) {
593 /* change blocksize */
594 ASSERT(dn->dn_maxblkid == 0 &&
595 (BP_IS_HOLE(&dn->dn_phys->dn_blkptr[0]) ||
596 dnode_block_freed(dn, 0)));
597 dnode_setdblksz(dn, blocksize);
598 dn->dn_next_blksz[tx->tx_txg&TXG_MASK] = blocksize;
599 }
600 if (dn->dn_bonuslen != bonuslen)
601 dn->dn_next_bonuslen[tx->tx_txg&TXG_MASK] = bonuslen;
602
603 if (bonustype == DMU_OT_SA) /* Maximize bonus space for SA */
604 nblkptr = 1;
605 else
606 nblkptr = 1 + ((DN_MAX_BONUSLEN - bonuslen) >> SPA_BLKPTRSHIFT);
607 if (dn->dn_bonustype != bonustype)
608 dn->dn_next_bonustype[tx->tx_txg&TXG_MASK] = bonustype;
609 if (dn->dn_nblkptr != nblkptr)
610 dn->dn_next_nblkptr[tx->tx_txg&TXG_MASK] = nblkptr;
611 if (dn->dn_phys->dn_flags & DNODE_FLAG_SPILL_BLKPTR) {
612 dbuf_rm_spill(dn, tx);
613 dnode_rm_spill(dn, tx);
614 }
615 rw_exit(&dn->dn_struct_rwlock);
616
617 /* change type */
618 dn->dn_type = ot;
619
620 /* change bonus size and type */
621 mutex_enter(&dn->dn_mtx);
622 dn->dn_bonustype = bonustype;
623 dn->dn_bonuslen = bonuslen;
624 dn->dn_nblkptr = nblkptr;
625 dn->dn_checksum = ZIO_CHECKSUM_INHERIT;
626 dn->dn_compress = ZIO_COMPRESS_INHERIT;
627 ASSERT3U(dn->dn_nblkptr, <=, DN_MAX_NBLKPTR);
628
629 /* fix up the bonus db_size */
630 if (dn->dn_bonus) {
631 dn->dn_bonus->db.db_size =
632 DN_MAX_BONUSLEN - (dn->dn_nblkptr-1) * sizeof (blkptr_t);
633 ASSERT(dn->dn_bonuslen <= dn->dn_bonus->db.db_size);
634 }
635
636 dn->dn_allocated_txg = tx->tx_txg;
637 mutex_exit(&dn->dn_mtx);
638 }
639
640 #ifdef DNODE_STATS
641 static struct {
642 uint64_t dms_dnode_invalid;
643 uint64_t dms_dnode_recheck1;
644 uint64_t dms_dnode_recheck2;
645 uint64_t dms_dnode_special;
646 uint64_t dms_dnode_handle;
647 uint64_t dms_dnode_rwlock;
648 uint64_t dms_dnode_active;
649 } dnode_move_stats;
650 #endif /* DNODE_STATS */
651
652 static void
653 dnode_move_impl(dnode_t *odn, dnode_t *ndn)
654 {
655 int i;
656
657 ASSERT(!RW_LOCK_HELD(&odn->dn_struct_rwlock));
658 ASSERT(MUTEX_NOT_HELD(&odn->dn_mtx));
659 ASSERT(MUTEX_NOT_HELD(&odn->dn_dbufs_mtx));
660 ASSERT(!RW_LOCK_HELD(&odn->dn_zfetch.zf_rwlock));
661
662 /* Copy fields. */
663 ndn->dn_objset = odn->dn_objset;
664 ndn->dn_object = odn->dn_object;
665 ndn->dn_dbuf = odn->dn_dbuf;
666 ndn->dn_handle = odn->dn_handle;
667 ndn->dn_phys = odn->dn_phys;
668 ndn->dn_type = odn->dn_type;
669 ndn->dn_bonuslen = odn->dn_bonuslen;
670 ndn->dn_bonustype = odn->dn_bonustype;
671 ndn->dn_nblkptr = odn->dn_nblkptr;
672 ndn->dn_checksum = odn->dn_checksum;
673 ndn->dn_compress = odn->dn_compress;
674 ndn->dn_nlevels = odn->dn_nlevels;
675 ndn->dn_indblkshift = odn->dn_indblkshift;
676 ndn->dn_datablkshift = odn->dn_datablkshift;
677 ndn->dn_datablkszsec = odn->dn_datablkszsec;
678 ndn->dn_datablksz = odn->dn_datablksz;
679 ndn->dn_maxblkid = odn->dn_maxblkid;
680 bcopy(&odn->dn_next_nblkptr[0], &ndn->dn_next_nblkptr[0],
681 sizeof (odn->dn_next_nblkptr));
682 bcopy(&odn->dn_next_nlevels[0], &ndn->dn_next_nlevels[0],
683 sizeof (odn->dn_next_nlevels));
684 bcopy(&odn->dn_next_indblkshift[0], &ndn->dn_next_indblkshift[0],
685 sizeof (odn->dn_next_indblkshift));
686 bcopy(&odn->dn_next_bonustype[0], &ndn->dn_next_bonustype[0],
687 sizeof (odn->dn_next_bonustype));
688 bcopy(&odn->dn_rm_spillblk[0], &ndn->dn_rm_spillblk[0],
689 sizeof (odn->dn_rm_spillblk));
690 bcopy(&odn->dn_next_bonuslen[0], &ndn->dn_next_bonuslen[0],
691 sizeof (odn->dn_next_bonuslen));
692 bcopy(&odn->dn_next_blksz[0], &ndn->dn_next_blksz[0],
693 sizeof (odn->dn_next_blksz));
694 for (i = 0; i < TXG_SIZE; i++) {
695 list_move_tail(&ndn->dn_dirty_records[i],
696 &odn->dn_dirty_records[i]);
697 }
698 bcopy(&odn->dn_ranges[0], &ndn->dn_ranges[0], sizeof (odn->dn_ranges));
699 ndn->dn_allocated_txg = odn->dn_allocated_txg;
700 ndn->dn_free_txg = odn->dn_free_txg;
701 ndn->dn_assigned_txg = odn->dn_assigned_txg;
702 ndn->dn_dirtyctx = odn->dn_dirtyctx;
703 ndn->dn_dirtyctx_firstset = odn->dn_dirtyctx_firstset;
704 ASSERT(refcount_count(&odn->dn_tx_holds) == 0);
705 refcount_transfer(&ndn->dn_holds, &odn->dn_holds);
706 ASSERT(list_is_empty(&ndn->dn_dbufs));
707 list_move_tail(&ndn->dn_dbufs, &odn->dn_dbufs);
708 ndn->dn_dbufs_count = odn->dn_dbufs_count;
709 ndn->dn_bonus = odn->dn_bonus;
710 ndn->dn_have_spill = odn->dn_have_spill;
711 ndn->dn_zio = odn->dn_zio;
712 ndn->dn_oldused = odn->dn_oldused;
713 ndn->dn_oldflags = odn->dn_oldflags;
714 ndn->dn_olduid = odn->dn_olduid;
715 ndn->dn_oldgid = odn->dn_oldgid;
716 ndn->dn_newuid = odn->dn_newuid;
717 ndn->dn_newgid = odn->dn_newgid;
718 ndn->dn_id_flags = odn->dn_id_flags;
719 dmu_zfetch_init(&ndn->dn_zfetch, NULL);
720 list_move_tail(&ndn->dn_zfetch.zf_stream, &odn->dn_zfetch.zf_stream);
721 ndn->dn_zfetch.zf_dnode = odn->dn_zfetch.zf_dnode;
722 ndn->dn_zfetch.zf_stream_cnt = odn->dn_zfetch.zf_stream_cnt;
723 ndn->dn_zfetch.zf_alloc_fail = odn->dn_zfetch.zf_alloc_fail;
724
725 /*
726 * Update back pointers. Updating the handle fixes the back pointer of
727 * every descendant dbuf as well as the bonus dbuf.
728 */
729 ASSERT(ndn->dn_handle->dnh_dnode == odn);
730 ndn->dn_handle->dnh_dnode = ndn;
731 if (ndn->dn_zfetch.zf_dnode == odn) {
732 ndn->dn_zfetch.zf_dnode = ndn;
733 }
734
735 /*
736 * Invalidate the original dnode by clearing all of its back pointers.
737 */
738 odn->dn_dbuf = NULL;
739 odn->dn_handle = NULL;
740 list_create(&odn->dn_dbufs, sizeof (dmu_buf_impl_t),
741 offsetof(dmu_buf_impl_t, db_link));
742 odn->dn_dbufs_count = 0;
743 odn->dn_bonus = NULL;
744 odn->dn_zfetch.zf_dnode = NULL;
745
746 /*
747 * Set the low bit of the objset pointer to ensure that dnode_move()
748 * recognizes the dnode as invalid in any subsequent callback.
749 */
750 POINTER_INVALIDATE(&odn->dn_objset);
751
752 /*
753 * Satisfy the destructor.
754 */
755 for (i = 0; i < TXG_SIZE; i++) {
756 list_create(&odn->dn_dirty_records[i],
757 sizeof (dbuf_dirty_record_t),
758 offsetof(dbuf_dirty_record_t, dr_dirty_node));
759 odn->dn_ranges[i].avl_root = NULL;
760 odn->dn_ranges[i].avl_numnodes = 0;
761 odn->dn_next_nlevels[i] = 0;
762 odn->dn_next_indblkshift[i] = 0;
763 odn->dn_next_bonustype[i] = 0;
764 odn->dn_rm_spillblk[i] = 0;
765 odn->dn_next_bonuslen[i] = 0;
766 odn->dn_next_blksz[i] = 0;
767 }
768 odn->dn_allocated_txg = 0;
769 odn->dn_free_txg = 0;
770 odn->dn_assigned_txg = 0;
771 odn->dn_dirtyctx = 0;
772 odn->dn_dirtyctx_firstset = NULL;
773 odn->dn_have_spill = B_FALSE;
774 odn->dn_zio = NULL;
775 odn->dn_oldused = 0;
776 odn->dn_oldflags = 0;
777 odn->dn_olduid = 0;
778 odn->dn_oldgid = 0;
779 odn->dn_newuid = 0;
780 odn->dn_newgid = 0;
781 odn->dn_id_flags = 0;
782
783 /*
784 * Mark the dnode.
785 */
786 ndn->dn_moved = 1;
787 odn->dn_moved = (uint8_t)-1;
788 }
789
790 #ifdef _KERNEL
791 /*ARGSUSED*/
792 static kmem_cbrc_t
793 dnode_move(void *buf, void *newbuf, size_t size, void *arg)
794 {
795 dnode_t *odn = buf, *ndn = newbuf;
796 objset_t *os;
797 int64_t refcount;
798 uint32_t dbufs;
799
800 /*
801 * The dnode is on the objset's list of known dnodes if the objset
802 * pointer is valid. We set the low bit of the objset pointer when
803 * freeing the dnode to invalidate it, and the memory patterns written
804 * by kmem (baddcafe and deadbeef) set at least one of the two low bits.
805 * A newly created dnode sets the objset pointer last of all to indicate
806 * that the dnode is known and in a valid state to be moved by this
807 * function.
808 */
809 os = odn->dn_objset;
810 if (!POINTER_IS_VALID(os)) {
811 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_invalid);
812 return (KMEM_CBRC_DONT_KNOW);
813 }
814
815 /*
816 * Ensure that the objset does not go away during the move.
817 */
818 rw_enter(&os_lock, RW_WRITER);
819 if (os != odn->dn_objset) {
820 rw_exit(&os_lock);
821 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_recheck1);
822 return (KMEM_CBRC_DONT_KNOW);
823 }
824
825 /*
826 * If the dnode is still valid, then so is the objset. We know that no
827 * valid objset can be freed while we hold os_lock, so we can safely
828 * ensure that the objset remains in use.
829 */
830 mutex_enter(&os->os_lock);
831
832 /*
833 * Recheck the objset pointer in case the dnode was removed just before
834 * acquiring the lock.
835 */
836 if (os != odn->dn_objset) {
837 mutex_exit(&os->os_lock);
838 rw_exit(&os_lock);
839 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_recheck2);
840 return (KMEM_CBRC_DONT_KNOW);
841 }
842
843 /*
844 * At this point we know that as long as we hold os->os_lock, the dnode
845 * cannot be freed and fields within the dnode can be safely accessed.
846 * The objset listing this dnode cannot go away as long as this dnode is
847 * on its list.
848 */
849 rw_exit(&os_lock);
850 if (DMU_OBJECT_IS_SPECIAL(odn->dn_object)) {
851 mutex_exit(&os->os_lock);
852 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_special);
853 return (KMEM_CBRC_NO);
854 }
855 ASSERT(odn->dn_dbuf != NULL); /* only "special" dnodes have no parent */
856
857 /*
858 * Lock the dnode handle to prevent the dnode from obtaining any new
859 * holds. This also prevents the descendant dbufs and the bonus dbuf
860 * from accessing the dnode, so that we can discount their holds. The
861 * handle is safe to access because we know that while the dnode cannot
862 * go away, neither can its handle. Once we hold dnh_zrlock, we can
863 * safely move any dnode referenced only by dbufs.
864 */
865 if (!zrl_tryenter(&odn->dn_handle->dnh_zrlock)) {
866 mutex_exit(&os->os_lock);
867 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_handle);
868 return (KMEM_CBRC_LATER);
869 }
870
871 /*
872 * Ensure a consistent view of the dnode's holds and the dnode's dbufs.
873 * We need to guarantee that there is a hold for every dbuf in order to
874 * determine whether the dnode is actively referenced. Falsely matching
875 * a dbuf to an active hold would lead to an unsafe move. It's possible
876 * that a thread already having an active dnode hold is about to add a
877 * dbuf, and we can't compare hold and dbuf counts while the add is in
878 * progress.
879 */
880 if (!rw_tryenter(&odn->dn_struct_rwlock, RW_WRITER)) {
881 zrl_exit(&odn->dn_handle->dnh_zrlock);
882 mutex_exit(&os->os_lock);
883 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_rwlock);
884 return (KMEM_CBRC_LATER);
885 }
886
887 /*
888 * A dbuf may be removed (evicted) without an active dnode hold. In that
889 * case, the dbuf count is decremented under the handle lock before the
890 * dbuf's hold is released. This order ensures that if we count the hold
891 * after the dbuf is removed but before its hold is released, we will
892 * treat the unmatched hold as active and exit safely. If we count the
893 * hold before the dbuf is removed, the hold is discounted, and the
894 * removal is blocked until the move completes.
895 */
896 refcount = refcount_count(&odn->dn_holds);
897 ASSERT(refcount >= 0);
898 dbufs = odn->dn_dbufs_count;
899
900 /* We can't have more dbufs than dnode holds. */
901 ASSERT3U(dbufs, <=, refcount);
902 DTRACE_PROBE3(dnode__move, dnode_t *, odn, int64_t, refcount,
903 uint32_t, dbufs);
904
905 if (refcount > dbufs) {
906 rw_exit(&odn->dn_struct_rwlock);
907 zrl_exit(&odn->dn_handle->dnh_zrlock);
908 mutex_exit(&os->os_lock);
909 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_active);
910 return (KMEM_CBRC_LATER);
911 }
912
913 rw_exit(&odn->dn_struct_rwlock);
914
915 /*
916 * At this point we know that anyone with a hold on the dnode is not
917 * actively referencing it. The dnode is known and in a valid state to
918 * move. We're holding the locks needed to execute the critical section.
919 */
920 dnode_move_impl(odn, ndn);
921
922 list_link_replace(&odn->dn_link, &ndn->dn_link);
923 /* If the dnode was safe to move, the refcount cannot have changed. */
924 ASSERT(refcount == refcount_count(&ndn->dn_holds));
925 ASSERT(dbufs == ndn->dn_dbufs_count);
926 zrl_exit(&ndn->dn_handle->dnh_zrlock); /* handle has moved */
927 mutex_exit(&os->os_lock);
928
929 return (KMEM_CBRC_YES);
930 }
931 #endif /* _KERNEL */
932
933 void
934 dnode_special_close(dnode_handle_t *dnh)
935 {
936 dnode_t *dn = dnh->dnh_dnode;
937
938 /*
939 * Wait for final references to the dnode to clear. This can
940 * only happen if the arc is asyncronously evicting state that
941 * has a hold on this dnode while we are trying to evict this
942 * dnode.
943 */
944 while (refcount_count(&dn->dn_holds) > 0)
945 delay(1);
946 zrl_add(&dnh->dnh_zrlock);
947 dnode_destroy(dn); /* implicit zrl_remove() */
948 zrl_destroy(&dnh->dnh_zrlock);
949 dnh->dnh_dnode = NULL;
950 }
951
952 dnode_t *
953 dnode_special_open(objset_t *os, dnode_phys_t *dnp, uint64_t object,
954 dnode_handle_t *dnh)
955 {
956 dnode_t *dn = dnode_create(os, dnp, NULL, object, dnh);
957 dnh->dnh_dnode = dn;
958 zrl_init(&dnh->dnh_zrlock);
959 DNODE_VERIFY(dn);
960 return (dn);
961 }
962
963 static void
964 dnode_buf_pageout(dmu_buf_user_t *dbu)
965 {
966 dnode_children_t *children_dnodes = (dnode_children_t *)dbu;
967 int i;
968
969 for (i = 0; i < children_dnodes->dnc_count; i++) {
970 dnode_handle_t *dnh = &children_dnodes->dnc_children[i];
971 dnode_t *dn;
972
973 /*
974 * The dnode handle lock guards against the dnode moving to
975 * another valid address, so there is no need here to guard
976 * against changes to or from NULL.
977 */
978 if (dnh->dnh_dnode == NULL) {
979 zrl_destroy(&dnh->dnh_zrlock);
980 continue;
981 }
982
983 zrl_add(&dnh->dnh_zrlock);
984 dn = dnh->dnh_dnode;
985 /*
986 * If there are holds on this dnode, then there should
987 * be holds on the dnode's containing dbuf as well; thus
988 * it wouldn't be eligible for eviction and this function
989 * would not have been called.
990 */
991 ASSERT(refcount_is_zero(&dn->dn_holds));
992 ASSERT(refcount_is_zero(&dn->dn_tx_holds));
993
994 dnode_destroy(dn); /* implicit zrl_remove() */
995 zrl_destroy(&dnh->dnh_zrlock);
996 dnh->dnh_dnode = NULL;
997 }
998 kmem_free(children_dnodes, sizeof (dnode_children_t) +
999 (children_dnodes->dnc_count - 1) * sizeof (dnode_handle_t));
1000 }
1001
1002 /*
1003 * errors:
1004 * EINVAL - invalid object number.
1005 * EIO - i/o error.
1006 * succeeds even for free dnodes.
1007 */
1008 int
1009 dnode_hold_impl(objset_t *os, uint64_t object, int flag,
1010 void *tag, dnode_t **dnp)
1011 {
1012 int epb, idx, err;
1013 int drop_struct_lock = FALSE;
1014 int type;
1015 uint64_t blk;
1016 dnode_t *mdn, *dn;
1017 dmu_buf_impl_t *db;
1018 dnode_children_t *children_dnodes;
1019 dnode_handle_t *dnh;
1020
1021 /*
1022 * If you are holding the spa config lock as writer, you shouldn't
1023 * be asking the DMU to do *anything* unless it's the root pool
1024 * which may require us to read from the root filesystem while
1025 * holding some (not all) of the locks as writer.
1026 */
1027 ASSERT(spa_config_held(os->os_spa, SCL_ALL, RW_WRITER) == 0 ||
1028 (spa_is_root(os->os_spa) &&
1029 spa_config_held(os->os_spa, SCL_STATE, RW_WRITER)));
1030
1031 if (object == DMU_USERUSED_OBJECT || object == DMU_GROUPUSED_OBJECT) {
1032 dn = (object == DMU_USERUSED_OBJECT) ?
1033 DMU_USERUSED_DNODE(os) : DMU_GROUPUSED_DNODE(os);
1034 if (dn == NULL)
1035 return (SET_ERROR(ENOENT));
1036 type = dn->dn_type;
1037 if ((flag & DNODE_MUST_BE_ALLOCATED) && type == DMU_OT_NONE)
1038 return (SET_ERROR(ENOENT));
1039 if ((flag & DNODE_MUST_BE_FREE) && type != DMU_OT_NONE)
1040 return (SET_ERROR(EEXIST));
1041 DNODE_VERIFY(dn);
1042 (void) refcount_add(&dn->dn_holds, tag);
1043 *dnp = dn;
1044 return (0);
1045 }
1046
1047 if (object == 0 || object >= DN_MAX_OBJECT)
1048 return (SET_ERROR(EINVAL));
1049
1050 mdn = DMU_META_DNODE(os);
1051 ASSERT(mdn->dn_object == DMU_META_DNODE_OBJECT);
1052
1053 DNODE_VERIFY(mdn);
1054
1055 if (!RW_WRITE_HELD(&mdn->dn_struct_rwlock)) {
1056 rw_enter(&mdn->dn_struct_rwlock, RW_READER);
1057 drop_struct_lock = TRUE;
1058 }
1059
1060 blk = dbuf_whichblock(mdn, object * sizeof (dnode_phys_t));
1061
1062 db = dbuf_hold(mdn, blk, FTAG);
1063 if (drop_struct_lock)
1064 rw_exit(&mdn->dn_struct_rwlock);
1065 if (db == NULL)
1066 return (SET_ERROR(EIO));
1067 err = dbuf_read(db, NULL, DB_RF_CANFAIL);
1068 if (err) {
1069 dbuf_rele(db, FTAG);
1070 return (err);
1071 }
1072
1073 ASSERT3U(db->db.db_size, >=, 1<<DNODE_SHIFT);
1074 epb = db->db.db_size >> DNODE_SHIFT;
1075
1076 idx = object & (epb-1);
1077
1078 ASSERT(DB_DNODE(db)->dn_type == DMU_OT_DNODE);
1079 children_dnodes = (dnode_children_t *)dmu_buf_get_user(&db->db);
1080 if (children_dnodes == NULL) {
1081 int i;
1082 dnode_children_t *winner;
1083 children_dnodes = kmem_alloc(sizeof (dnode_children_t) +
1084 (epb - 1) * sizeof (dnode_handle_t), KM_SLEEP);
1085 children_dnodes->dnc_count = epb;
1086 dnh = &children_dnodes->dnc_children[0];
1087 for (i = 0; i < epb; i++) {
1088 zrl_init(&dnh[i].dnh_zrlock);
1089 dnh[i].dnh_dnode = NULL;
1090 }
1091 dmu_buf_init_user(&children_dnodes->db_evict,
1092 dnode_buf_pageout);
1093 winner = (dnode_children_t *)
1094 dmu_buf_set_user(&db->db, &children_dnodes->db_evict);
1095 if (winner) {
1096 kmem_free(children_dnodes, sizeof (dnode_children_t) +
1097 (epb - 1) * sizeof (dnode_handle_t));
1098 children_dnodes = winner;
1099 }
1100 }
1101 ASSERT(children_dnodes->dnc_count == epb);
1102
1103 dnh = &children_dnodes->dnc_children[idx];
1104 zrl_add(&dnh->dnh_zrlock);
1105 if ((dn = dnh->dnh_dnode) == NULL) {
1106 dnode_phys_t *phys = (dnode_phys_t *)db->db.db_data+idx;
1107 dnode_t *winner;
1108
1109 dn = dnode_create(os, phys, db, object, dnh);
1110 winner = atomic_cas_ptr(&dnh->dnh_dnode, NULL, dn);
1111 if (winner != NULL) {
1112 zrl_add(&dnh->dnh_zrlock);
1113 dnode_destroy(dn); /* implicit zrl_remove() */
1114 dn = winner;
1115 }
1116 }
1117
1118 mutex_enter(&dn->dn_mtx);
1119 type = dn->dn_type;
1120 if (dn->dn_free_txg ||
1121 ((flag & DNODE_MUST_BE_ALLOCATED) && type == DMU_OT_NONE) ||
1122 ((flag & DNODE_MUST_BE_FREE) &&
1123 (type != DMU_OT_NONE || !refcount_is_zero(&dn->dn_holds)))) {
1124 mutex_exit(&dn->dn_mtx);
1125 zrl_remove(&dnh->dnh_zrlock);
1126 dbuf_rele(db, FTAG);
1127 return (type == DMU_OT_NONE ? ENOENT : EEXIST);
1128 }
1129 mutex_exit(&dn->dn_mtx);
1130
1131 if (refcount_add(&dn->dn_holds, tag) == 1)
1132 dbuf_add_ref(db, dnh);
1133 /* Now we can rely on the hold to prevent the dnode from moving. */
1134 zrl_remove(&dnh->dnh_zrlock);
1135
1136 DNODE_VERIFY(dn);
1137 ASSERT3P(dn->dn_dbuf, ==, db);
1138 ASSERT3U(dn->dn_object, ==, object);
1139 dbuf_rele(db, FTAG);
1140
1141 *dnp = dn;
1142 return (0);
1143 }
1144
1145 /*
1146 * Return held dnode if the object is allocated, NULL if not.
1147 */
1148 int
1149 dnode_hold(objset_t *os, uint64_t object, void *tag, dnode_t **dnp)
1150 {
1151 return (dnode_hold_impl(os, object, DNODE_MUST_BE_ALLOCATED, tag, dnp));
1152 }
1153
1154 /*
1155 * Can only add a reference if there is already at least one
1156 * reference on the dnode. Returns FALSE if unable to add a
1157 * new reference.
1158 */
1159 boolean_t
1160 dnode_add_ref(dnode_t *dn, void *tag)
1161 {
1162 mutex_enter(&dn->dn_mtx);
1163 if (refcount_is_zero(&dn->dn_holds)) {
1164 mutex_exit(&dn->dn_mtx);
1165 return (FALSE);
1166 }
1167 VERIFY(1 < refcount_add(&dn->dn_holds, tag));
1168 mutex_exit(&dn->dn_mtx);
1169 return (TRUE);
1170 }
1171
1172 void
1173 dnode_rele(dnode_t *dn, void *tag)
1174 {
1175 uint64_t refs;
1176 /* Get while the hold prevents the dnode from moving. */
1177 dmu_buf_impl_t *db = dn->dn_dbuf;
1178 dnode_handle_t *dnh = dn->dn_handle;
1179
1180 mutex_enter(&dn->dn_mtx);
1181 refs = refcount_remove(&dn->dn_holds, tag);
1182 mutex_exit(&dn->dn_mtx);
1183
1184 /*
1185 * It's unsafe to release the last hold on a dnode by dnode_rele() or
1186 * indirectly by dbuf_rele() while relying on the dnode handle to
1187 * prevent the dnode from moving, since releasing the last hold could
1188 * result in the dnode's parent dbuf evicting its dnode handles. For
1189 * that reason anyone calling dnode_rele() or dbuf_rele() without some
1190 * other direct or indirect hold on the dnode must first drop the dnode
1191 * handle.
1192 */
1193 ASSERT(refs > 0 || dnh->dnh_zrlock.zr_owner != curthread);
1194
1195 /* NOTE: the DNODE_DNODE does not have a dn_dbuf */
1196 if (refs == 0 && db != NULL) {
1197 /*
1198 * Another thread could add a hold to the dnode handle in
1199 * dnode_hold_impl() while holding the parent dbuf. Since the
1200 * hold on the parent dbuf prevents the handle from being
1201 * destroyed, the hold on the handle is OK. We can't yet assert
1202 * that the handle has zero references, but that will be
1203 * asserted anyway when the handle gets destroyed.
1204 */
1205 dbuf_rele(db, dnh);
1206 }
1207 }
1208
1209 void
1210 dnode_setdirty(dnode_t *dn, dmu_tx_t *tx)
1211 {
1212 objset_t *os = dn->dn_objset;
1213 uint64_t txg = tx->tx_txg;
1214
1215 if (DMU_OBJECT_IS_SPECIAL(dn->dn_object)) {
1216 dsl_dataset_dirty(os->os_dsl_dataset, tx);
1217 return;
1218 }
1219
1220 DNODE_VERIFY(dn);
1221
1222 #ifdef ZFS_DEBUG
1223 mutex_enter(&dn->dn_mtx);
1224 ASSERT(dn->dn_phys->dn_type || dn->dn_allocated_txg);
1225 ASSERT(dn->dn_free_txg == 0 || dn->dn_free_txg >= txg);
1226 mutex_exit(&dn->dn_mtx);
1227 #endif
1228
1229 /*
1230 * Determine old uid/gid when necessary
1231 */
1232 dmu_objset_userquota_get_ids(dn, B_TRUE, tx);
1233
1234 mutex_enter(&os->os_lock);
1235
1236 /*
1237 * If we are already marked dirty, we're done.
1238 */
1239 if (list_link_active(&dn->dn_dirty_link[txg & TXG_MASK])) {
1240 mutex_exit(&os->os_lock);
1241 return;
1242 }
1243
1244 ASSERT(!refcount_is_zero(&dn->dn_holds) || list_head(&dn->dn_dbufs));
1245 ASSERT(dn->dn_datablksz != 0);
1246 ASSERT0(dn->dn_next_bonuslen[txg&TXG_MASK]);
1247 ASSERT0(dn->dn_next_blksz[txg&TXG_MASK]);
1248 ASSERT0(dn->dn_next_bonustype[txg&TXG_MASK]);
1249
1250 dprintf_ds(os->os_dsl_dataset, "obj=%llu txg=%llu\n",
1251 dn->dn_object, txg);
1252
1253 if (dn->dn_free_txg > 0 && dn->dn_free_txg <= txg) {
1254 list_insert_tail(&os->os_free_dnodes[txg&TXG_MASK], dn);
1255 } else {
1256 list_insert_tail(&os->os_dirty_dnodes[txg&TXG_MASK], dn);
1257 }
1258
1259 mutex_exit(&os->os_lock);
1260
1261 /*
1262 * The dnode maintains a hold on its containing dbuf as
1263 * long as there are holds on it. Each instantiated child
1264 * dbuf maintains a hold on the dnode. When the last child
1265 * drops its hold, the dnode will drop its hold on the
1266 * containing dbuf. We add a "dirty hold" here so that the
1267 * dnode will hang around after we finish processing its
1268 * children.
1269 */
1270 VERIFY(dnode_add_ref(dn, (void *)(uintptr_t)tx->tx_txg));
1271
1272 (void) dbuf_dirty(dn->dn_dbuf, tx);
1273
1274 dsl_dataset_dirty(os->os_dsl_dataset, tx);
1275 }
1276
1277 void
1278 dnode_free(dnode_t *dn, dmu_tx_t *tx)
1279 {
1280 int txgoff = tx->tx_txg & TXG_MASK;
1281
1282 dprintf("dn=%p txg=%llu\n", dn, tx->tx_txg);
1283
1284 /* we should be the only holder... hopefully */
1285 /* ASSERT3U(refcount_count(&dn->dn_holds), ==, 1); */
1286
1287 mutex_enter(&dn->dn_mtx);
1288 if (dn->dn_type == DMU_OT_NONE || dn->dn_free_txg) {
1289 mutex_exit(&dn->dn_mtx);
1290 return;
1291 }
1292 dn->dn_free_txg = tx->tx_txg;
1293 mutex_exit(&dn->dn_mtx);
1294
1295 /*
1296 * If the dnode is already dirty, it needs to be moved from
1297 * the dirty list to the free list.
1298 */
1299 mutex_enter(&dn->dn_objset->os_lock);
1300 if (list_link_active(&dn->dn_dirty_link[txgoff])) {
1301 list_remove(&dn->dn_objset->os_dirty_dnodes[txgoff], dn);
1302 list_insert_tail(&dn->dn_objset->os_free_dnodes[txgoff], dn);
1303 mutex_exit(&dn->dn_objset->os_lock);
1304 } else {
1305 mutex_exit(&dn->dn_objset->os_lock);
1306 dnode_setdirty(dn, tx);
1307 }
1308 }
1309
1310 /*
1311 * Try to change the block size for the indicated dnode. This can only
1312 * succeed if there are no blocks allocated or dirty beyond first block
1313 */
1314 int
1315 dnode_set_blksz(dnode_t *dn, uint64_t size, int ibs, dmu_tx_t *tx)
1316 {
1317 dmu_buf_impl_t *db, *db_next;
1318 int err;
1319
1320 if (size == 0)
1321 size = SPA_MINBLOCKSIZE;
1322 if (size > SPA_MAXBLOCKSIZE)
1323 size = SPA_MAXBLOCKSIZE;
1324 else
1325 size = P2ROUNDUP(size, SPA_MINBLOCKSIZE);
1326
1327 if (ibs == dn->dn_indblkshift)
1328 ibs = 0;
1329
1330 if (size >> SPA_MINBLOCKSHIFT == dn->dn_datablkszsec && ibs == 0)
1331 return (0);
1332
1333 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
1334
1335 /* Check for any allocated blocks beyond the first */
1336 if (dn->dn_phys->dn_maxblkid != 0)
1337 goto fail;
1338
1339 mutex_enter(&dn->dn_dbufs_mtx);
1340 for (db = list_head(&dn->dn_dbufs); db; db = db_next) {
1341 db_next = list_next(&dn->dn_dbufs, db);
1342
1343 if (db->db_blkid != 0 && db->db_blkid != DMU_BONUS_BLKID &&
1344 db->db_blkid != DMU_SPILL_BLKID) {
1345 mutex_exit(&dn->dn_dbufs_mtx);
1346 goto fail;
1347 }
1348 }
1349 mutex_exit(&dn->dn_dbufs_mtx);
1350
1351 if (ibs && dn->dn_nlevels != 1)
1352 goto fail;
1353
1354 /* resize the old block */
1355 err = dbuf_hold_impl(dn, 0, 0, TRUE, FTAG, &db);
1356 if (err == 0)
1357 dbuf_new_size(db, size, tx);
1358 else if (err != ENOENT)
1359 goto fail;
1360
1361 dnode_setdblksz(dn, size);
1362 dnode_setdirty(dn, tx);
1363 dn->dn_next_blksz[tx->tx_txg&TXG_MASK] = size;
1364 if (ibs) {
1365 dn->dn_indblkshift = ibs;
1366 dn->dn_next_indblkshift[tx->tx_txg&TXG_MASK] = ibs;
1367 }
1368 /* rele after we have fixed the blocksize in the dnode */
1369 if (db)
1370 dbuf_rele(db, FTAG);
1371
1372 rw_exit(&dn->dn_struct_rwlock);
1373 return (0);
1374
1375 fail:
1376 rw_exit(&dn->dn_struct_rwlock);
1377 return (SET_ERROR(ENOTSUP));
1378 }
1379
1380 /* read-holding callers must not rely on the lock being continuously held */
1381 void
1382 dnode_new_blkid(dnode_t *dn, uint64_t blkid, dmu_tx_t *tx, boolean_t have_read)
1383 {
1384 uint64_t txgoff = tx->tx_txg & TXG_MASK;
1385 int epbs, new_nlevels;
1386 uint64_t sz;
1387
1388 ASSERT(blkid != DMU_BONUS_BLKID);
1389
1390 ASSERT(have_read ?
1391 RW_READ_HELD(&dn->dn_struct_rwlock) :
1392 RW_WRITE_HELD(&dn->dn_struct_rwlock));
1393
1394 /*
1395 * if we have a read-lock, check to see if we need to do any work
1396 * before upgrading to a write-lock.
1397 */
1398 if (have_read) {
1399 if (blkid <= dn->dn_maxblkid)
1400 return;
1401
1402 if (!rw_tryupgrade(&dn->dn_struct_rwlock)) {
1403 rw_exit(&dn->dn_struct_rwlock);
1404 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
1405 }
1406 }
1407
1408 if (blkid <= dn->dn_maxblkid)
1409 goto out;
1410
1411 dn->dn_maxblkid = blkid;
1412
1413 /*
1414 * Compute the number of levels necessary to support the new maxblkid.
1415 */
1416 new_nlevels = 1;
1417 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT;
1418 for (sz = dn->dn_nblkptr;
1419 sz <= blkid && sz >= dn->dn_nblkptr; sz <<= epbs)
1420 new_nlevels++;
1421
1422 if (new_nlevels > dn->dn_nlevels) {
1423 int old_nlevels = dn->dn_nlevels;
1424 dmu_buf_impl_t *db;
1425 list_t *list;
1426 dbuf_dirty_record_t *new, *dr, *dr_next;
1427
1428 dn->dn_nlevels = new_nlevels;
1429
1430 ASSERT3U(new_nlevels, >, dn->dn_next_nlevels[txgoff]);
1431 dn->dn_next_nlevels[txgoff] = new_nlevels;
1432
1433 /* dirty the left indirects */
1434 db = dbuf_hold_level(dn, old_nlevels, 0, FTAG);
1435 ASSERT(db != NULL);
1436 new = dbuf_dirty(db, tx);
1437 dbuf_rele(db, FTAG);
1438
1439 /* transfer the dirty records to the new indirect */
1440 mutex_enter(&dn->dn_mtx);
1441 mutex_enter(&new->dt.di.dr_mtx);
1442 list = &dn->dn_dirty_records[txgoff];
1443 for (dr = list_head(list); dr; dr = dr_next) {
1444 dr_next = list_next(&dn->dn_dirty_records[txgoff], dr);
1445 if (dr->dr_dbuf->db_level != new_nlevels-1 &&
1446 dr->dr_dbuf->db_blkid != DMU_BONUS_BLKID &&
1447 dr->dr_dbuf->db_blkid != DMU_SPILL_BLKID) {
1448 ASSERT(dr->dr_dbuf->db_level == old_nlevels-1);
1449 list_remove(&dn->dn_dirty_records[txgoff], dr);
1450 list_insert_tail(&new->dt.di.dr_children, dr);
1451 dr->dr_parent = new;
1452 }
1453 }
1454 mutex_exit(&new->dt.di.dr_mtx);
1455 mutex_exit(&dn->dn_mtx);
1456 }
1457
1458 out:
1459 if (have_read)
1460 rw_downgrade(&dn->dn_struct_rwlock);
1461 }
1462
1463 void
1464 dnode_clear_range(dnode_t *dn, uint64_t blkid, uint64_t nblks, dmu_tx_t *tx)
1465 {
1466 avl_tree_t *tree = &dn->dn_ranges[tx->tx_txg&TXG_MASK];
1467 avl_index_t where;
1468 free_range_t *rp;
1469 free_range_t rp_tofind;
1470 uint64_t endblk = blkid + nblks;
1471
1472 ASSERT(MUTEX_HELD(&dn->dn_mtx));
1473 ASSERT(nblks <= UINT64_MAX - blkid); /* no overflow */
1474
1475 dprintf_dnode(dn, "blkid=%llu nblks=%llu txg=%llu\n",
1476 blkid, nblks, tx->tx_txg);
1477 rp_tofind.fr_blkid = blkid;
1478 rp = avl_find(tree, &rp_tofind, &where);
1479 if (rp == NULL)
1480 rp = avl_nearest(tree, where, AVL_BEFORE);
1481 if (rp == NULL)
1482 rp = avl_nearest(tree, where, AVL_AFTER);
1483
1484 while (rp && (rp->fr_blkid <= blkid + nblks)) {
1485 uint64_t fr_endblk = rp->fr_blkid + rp->fr_nblks;
1486 free_range_t *nrp = AVL_NEXT(tree, rp);
1487
1488 if (blkid <= rp->fr_blkid && endblk >= fr_endblk) {
1489 /* clear this entire range */
1490 avl_remove(tree, rp);
1491 kmem_free(rp, sizeof (free_range_t));
1492 } else if (blkid <= rp->fr_blkid &&
1493 endblk > rp->fr_blkid && endblk < fr_endblk) {
1494 /* clear the beginning of this range */
1495 rp->fr_blkid = endblk;
1496 rp->fr_nblks = fr_endblk - endblk;
1497 } else if (blkid > rp->fr_blkid && blkid < fr_endblk &&
1498 endblk >= fr_endblk) {
1499 /* clear the end of this range */
1500 rp->fr_nblks = blkid - rp->fr_blkid;
1501 } else if (blkid > rp->fr_blkid && endblk < fr_endblk) {
1502 /* clear a chunk out of this range */
1503 free_range_t *new_rp =
1504 kmem_alloc(sizeof (free_range_t), KM_SLEEP);
1505
1506 new_rp->fr_blkid = endblk;
1507 new_rp->fr_nblks = fr_endblk - endblk;
1508 avl_insert_here(tree, new_rp, rp, AVL_AFTER);
1509 rp->fr_nblks = blkid - rp->fr_blkid;
1510 }
1511 /* there may be no overlap */
1512 rp = nrp;
1513 }
1514 }
1515
1516 void
1517 dnode_free_range(dnode_t *dn, uint64_t off, uint64_t len, dmu_tx_t *tx)
1518 {
1519 dmu_buf_impl_t *db;
1520 uint64_t blkoff, blkid, nblks;
1521 int blksz, blkshift, head, tail;
1522 int trunc = FALSE;
1523 int epbs;
1524
1525 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
1526 blksz = dn->dn_datablksz;
1527 blkshift = dn->dn_datablkshift;
1528 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT;
1529
1530 if (len == -1ULL) {
1531 len = UINT64_MAX - off;
1532 trunc = TRUE;
1533 }
1534
1535 /*
1536 * First, block align the region to free:
1537 */
1538 if (ISP2(blksz)) {
1539 head = P2NPHASE(off, blksz);
1540 blkoff = P2PHASE(off, blksz);
1541 if ((off >> blkshift) > dn->dn_maxblkid)
1542 goto out;
1543 } else {
1544 ASSERT(dn->dn_maxblkid == 0);
1545 if (off == 0 && len >= blksz) {
1546 /* Freeing the whole block; fast-track this request */
1547 blkid = 0;
1548 nblks = 1;
1549 goto done;
1550 } else if (off >= blksz) {
1551 /* Freeing past end-of-data */
1552 goto out;
1553 } else {
1554 /* Freeing part of the block. */
1555 head = blksz - off;
1556 ASSERT3U(head, >, 0);
1557 }
1558 blkoff = off;
1559 }
1560 /* zero out any partial block data at the start of the range */
1561 if (head) {
1562 ASSERT3U(blkoff + head, ==, blksz);
1563 if (len < head)
1564 head = len;
1565 if (dbuf_hold_impl(dn, 0, dbuf_whichblock(dn, off), TRUE,
1566 FTAG, &db) == 0) {
1567 caddr_t data;
1568
1569 /* don't dirty if it isn't on disk and isn't dirty */
1570 if (db->db_last_dirty ||
1571 (db->db_blkptr && !BP_IS_HOLE(db->db_blkptr))) {
1572 rw_exit(&dn->dn_struct_rwlock);
1573 dbuf_will_dirty(db, tx);
1574 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
1575 data = db->db.db_data;
1576 bzero(data + blkoff, head);
1577 }
1578 dbuf_rele(db, FTAG);
1579 }
1580 off += head;
1581 len -= head;
1582 }
1583
1584 /* If the range was less than one block, we're done */
1585 if (len == 0)
1586 goto out;
1587
1588 /* If the remaining range is past end of file, we're done */
1589 if ((off >> blkshift) > dn->dn_maxblkid)
1590 goto out;
1591
1592 ASSERT(ISP2(blksz));
1593 if (trunc)
1594 tail = 0;
1595 else
1596 tail = P2PHASE(len, blksz);
1597
1598 ASSERT0(P2PHASE(off, blksz));
1599 /* zero out any partial block data at the end of the range */
1600 if (tail) {
1601 if (len < tail)
1602 tail = len;
1603 if (dbuf_hold_impl(dn, 0, dbuf_whichblock(dn, off+len),
1604 TRUE, FTAG, &db) == 0) {
1605 /* don't dirty if not on disk and not dirty */
1606 if (db->db_last_dirty ||
1607 (db->db_blkptr && !BP_IS_HOLE(db->db_blkptr))) {
1608 rw_exit(&dn->dn_struct_rwlock);
1609 dbuf_will_dirty(db, tx);
1610 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
1611 bzero(db->db.db_data, tail);
1612 }
1613 dbuf_rele(db, FTAG);
1614 }
1615 len -= tail;
1616 }
1617
1618 /* If the range did not include a full block, we are done */
1619 if (len == 0)
1620 goto out;
1621
1622 ASSERT(IS_P2ALIGNED(off, blksz));
1623 ASSERT(trunc || IS_P2ALIGNED(len, blksz));
1624 blkid = off >> blkshift;
1625 nblks = len >> blkshift;
1626 if (trunc)
1627 nblks += 1;
1628
1629 /*
1630 * Read in and mark all the level-1 indirects dirty,
1631 * so that they will stay in memory until syncing phase.
1632 * Always dirty the first and last indirect to make sure
1633 * we dirty all the partial indirects.
1634 */
1635 if (dn->dn_nlevels > 1) {
1636 uint64_t i, first, last;
1637 int shift = epbs + dn->dn_datablkshift;
1638
1639 first = blkid >> epbs;
1640 if (db = dbuf_hold_level(dn, 1, first, FTAG)) {
1641 dbuf_will_dirty(db, tx);
1642 dbuf_rele(db, FTAG);
1643 }
1644 if (trunc)
1645 last = dn->dn_maxblkid >> epbs;
1646 else
1647 last = (blkid + nblks - 1) >> epbs;
1648 if (last > first && (db = dbuf_hold_level(dn, 1, last, FTAG))) {
1649 dbuf_will_dirty(db, tx);
1650 dbuf_rele(db, FTAG);
1651 }
1652 for (i = first + 1; i < last; i++) {
1653 uint64_t ibyte = i << shift;
1654 int err;
1655
1656 err = dnode_next_offset(dn,
1657 DNODE_FIND_HAVELOCK, &ibyte, 1, 1, 0);
1658 i = ibyte >> shift;
1659 if (err == ESRCH || i >= last)
1660 break;
1661 ASSERT(err == 0);
1662 db = dbuf_hold_level(dn, 1, i, FTAG);
1663 if (db) {
1664 dbuf_will_dirty(db, tx);
1665 dbuf_rele(db, FTAG);
1666 }
1667 }
1668 }
1669 done:
1670 /*
1671 * Add this range to the dnode range list.
1672 * We will finish up this free operation in the syncing phase.
1673 */
1674 mutex_enter(&dn->dn_mtx);
1675 dnode_clear_range(dn, blkid, nblks, tx);
1676 {
1677 free_range_t *rp, *found;
1678 avl_index_t where;
1679 avl_tree_t *tree = &dn->dn_ranges[tx->tx_txg&TXG_MASK];
1680
1681 /* Add new range to dn_ranges */
1682 rp = kmem_alloc(sizeof (free_range_t), KM_SLEEP);
1683 rp->fr_blkid = blkid;
1684 rp->fr_nblks = nblks;
1685 found = avl_find(tree, rp, &where);
1686 ASSERT(found == NULL);
1687 avl_insert(tree, rp, where);
1688 dprintf_dnode(dn, "blkid=%llu nblks=%llu txg=%llu\n",
1689 blkid, nblks, tx->tx_txg);
1690 }
1691 mutex_exit(&dn->dn_mtx);
1692
1693 dbuf_free_range(dn, blkid, blkid + nblks - 1, tx);
1694 dnode_setdirty(dn, tx);
1695 out:
1696 if (trunc && dn->dn_maxblkid >= (off >> blkshift))
1697 dn->dn_maxblkid = (off >> blkshift ? (off >> blkshift) - 1 : 0);
1698
1699 rw_exit(&dn->dn_struct_rwlock);
1700 }
1701
1702 static boolean_t
1703 dnode_spill_freed(dnode_t *dn)
1704 {
1705 int i;
1706
1707 mutex_enter(&dn->dn_mtx);
1708 for (i = 0; i < TXG_SIZE; i++) {
1709 if (dn->dn_rm_spillblk[i] == DN_KILL_SPILLBLK)
1710 break;
1711 }
1712 mutex_exit(&dn->dn_mtx);
1713 return (i < TXG_SIZE);
1714 }
1715
1716 /* return TRUE if this blkid was freed in a recent txg, or FALSE if it wasn't */
1717 uint64_t
1718 dnode_block_freed(dnode_t *dn, uint64_t blkid)
1719 {
1720 free_range_t range_tofind;
1721 void *dp = spa_get_dsl(dn->dn_objset->os_spa);
1722 int i;
1723
1724 if (blkid == DMU_BONUS_BLKID)
1725 return (FALSE);
1726
1727 /*
1728 * If we're in the process of opening the pool, dp will not be
1729 * set yet, but there shouldn't be anything dirty.
1730 */
1731 if (dp == NULL)
1732 return (FALSE);
1733
1734 if (dn->dn_free_txg)
1735 return (TRUE);
1736
1737 if (blkid == DMU_SPILL_BLKID)
1738 return (dnode_spill_freed(dn));
1739
1740 range_tofind.fr_blkid = blkid;
1741 mutex_enter(&dn->dn_mtx);
1742 for (i = 0; i < TXG_SIZE; i++) {
1743 free_range_t *range_found;
1744 avl_index_t idx;
1745
1746 range_found = avl_find(&dn->dn_ranges[i], &range_tofind, &idx);
1747 if (range_found) {
1748 ASSERT(range_found->fr_nblks > 0);
1749 break;
1750 }
1751 range_found = avl_nearest(&dn->dn_ranges[i], idx, AVL_BEFORE);
1752 if (range_found &&
1753 range_found->fr_blkid + range_found->fr_nblks > blkid)
1754 break;
1755 }
1756 mutex_exit(&dn->dn_mtx);
1757 return (i < TXG_SIZE);
1758 }
1759
1760 /* call from syncing context when we actually write/free space for this dnode */
1761 void
1762 dnode_diduse_space(dnode_t *dn, int64_t delta)
1763 {
1764 uint64_t space;
1765 dprintf_dnode(dn, "dn=%p dnp=%p used=%llu delta=%lld\n",
1766 dn, dn->dn_phys,
1767 (u_longlong_t)dn->dn_phys->dn_used,
1768 (longlong_t)delta);
1769
1770 mutex_enter(&dn->dn_mtx);
1771 space = DN_USED_BYTES(dn->dn_phys);
1772 if (delta > 0) {
1773 ASSERT3U(space + delta, >=, space); /* no overflow */
1774 } else {
1775 ASSERT3U(space, >=, -delta); /* no underflow */
1776 }
1777 space += delta;
1778 if (spa_version(dn->dn_objset->os_spa) < SPA_VERSION_DNODE_BYTES) {
1779 ASSERT((dn->dn_phys->dn_flags & DNODE_FLAG_USED_BYTES) == 0);
1780 ASSERT0(P2PHASE(space, 1<<DEV_BSHIFT));
1781 dn->dn_phys->dn_used = space >> DEV_BSHIFT;
1782 } else {
1783 dn->dn_phys->dn_used = space;
1784 dn->dn_phys->dn_flags |= DNODE_FLAG_USED_BYTES;
1785 }
1786 mutex_exit(&dn->dn_mtx);
1787 }
1788
1789 /*
1790 * Call when we think we're going to write/free space in open context.
1791 * Be conservative (ie. OK to write less than this or free more than
1792 * this, but don't write more or free less).
1793 */
1794 void
1795 dnode_willuse_space(dnode_t *dn, int64_t space, dmu_tx_t *tx)
1796 {
1797 objset_t *os = dn->dn_objset;
1798 dsl_dataset_t *ds = os->os_dsl_dataset;
1799
1800 if (space > 0)
1801 space = spa_get_asize(os->os_spa, space);
1802
1803 if (ds)
1804 dsl_dir_willuse_space(ds->ds_dir, space, tx);
1805
1806 dmu_tx_willuse_space(tx, space);
1807 }
1808
1809 /*
1810 * This function scans a block at the indicated "level" looking for
1811 * a hole or data (depending on 'flags'). If level > 0, then we are
1812 * scanning an indirect block looking at its pointers. If level == 0,
1813 * then we are looking at a block of dnodes. If we don't find what we
1814 * are looking for in the block, we return ESRCH. Otherwise, return
1815 * with *offset pointing to the beginning (if searching forwards) or
1816 * end (if searching backwards) of the range covered by the block
1817 * pointer we matched on (or dnode).
1818 *
1819 * The basic search algorithm used below by dnode_next_offset() is to
1820 * use this function to search up the block tree (widen the search) until
1821 * we find something (i.e., we don't return ESRCH) and then search back
1822 * down the tree (narrow the search) until we reach our original search
1823 * level.
1824 */
1825 static int
1826 dnode_next_offset_level(dnode_t *dn, int flags, uint64_t *offset,
1827 int lvl, uint64_t blkfill, uint64_t txg)
1828 {
1829 dmu_buf_impl_t *db = NULL;
1830 void *data = NULL;
1831 uint64_t epbs = dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT;
1832 uint64_t epb = 1ULL << epbs;
1833 uint64_t minfill, maxfill;
1834 boolean_t hole;
1835 int i, inc, error, span;
1836
1837 dprintf("probing object %llu offset %llx level %d of %u\n",
1838 dn->dn_object, *offset, lvl, dn->dn_phys->dn_nlevels);
1839
1840 hole = ((flags & DNODE_FIND_HOLE) != 0);
1841 inc = (flags & DNODE_FIND_BACKWARDS) ? -1 : 1;
1842 ASSERT(txg == 0 || !hole);
1843
1844 if (lvl == dn->dn_phys->dn_nlevels) {
1845 error = 0;
1846 epb = dn->dn_phys->dn_nblkptr;
1847 data = dn->dn_phys->dn_blkptr;
1848 } else {
1849 uint64_t blkid = dbuf_whichblock(dn, *offset) >> (epbs * lvl);
1850 error = dbuf_hold_impl(dn, lvl, blkid, TRUE, FTAG, &db);
1851 if (error) {
1852 if (error != ENOENT)
1853 return (error);
1854 if (hole)
1855 return (0);
1856 /*
1857 * This can only happen when we are searching up
1858 * the block tree for data. We don't really need to
1859 * adjust the offset, as we will just end up looking
1860 * at the pointer to this block in its parent, and its
1861 * going to be unallocated, so we will skip over it.
1862 */
1863 return (SET_ERROR(ESRCH));
1864 }
1865 error = dbuf_read(db, NULL, DB_RF_CANFAIL | DB_RF_HAVESTRUCT);
1866 if (error) {
1867 dbuf_rele(db, FTAG);
1868 return (error);
1869 }
1870 data = db->db.db_data;
1871 }
1872
1873 if (db && txg &&
1874 (db->db_blkptr == NULL || db->db_blkptr->blk_birth <= txg)) {
1875 /*
1876 * This can only happen when we are searching up the tree
1877 * and these conditions mean that we need to keep climbing.
1878 */
1879 error = SET_ERROR(ESRCH);
1880 } else if (lvl == 0) {
1881 dnode_phys_t *dnp = data;
1882 span = DNODE_SHIFT;
1883 ASSERT(dn->dn_type == DMU_OT_DNODE);
1884
1885 for (i = (*offset >> span) & (blkfill - 1);
1886 i >= 0 && i < blkfill; i += inc) {
1887 if ((dnp[i].dn_type == DMU_OT_NONE) == hole)
1888 break;
1889 *offset += (1ULL << span) * inc;
1890 }
1891 if (i < 0 || i == blkfill)
1892 error = SET_ERROR(ESRCH);
1893 } else {
1894 blkptr_t *bp = data;
1895 uint64_t start = *offset;
1896 span = (lvl - 1) * epbs + dn->dn_datablkshift;
1897 minfill = 0;
1898 maxfill = blkfill << ((lvl - 1) * epbs);
1899
1900 if (hole)
1901 maxfill--;
1902 else
1903 minfill++;
1904
1905 *offset = *offset >> span;
1906 for (i = BF64_GET(*offset, 0, epbs);
1907 i >= 0 && i < epb; i += inc) {
1908 if (bp[i].blk_fill >= minfill &&
1909 bp[i].blk_fill <= maxfill &&
1910 (hole || bp[i].blk_birth > txg))
1911 break;
1912 if (inc > 0 || *offset > 0)
1913 *offset += inc;
1914 }
1915 *offset = *offset << span;
1916 if (inc < 0) {
1917 /* traversing backwards; position offset at the end */
1918 ASSERT3U(*offset, <=, start);
1919 *offset = MIN(*offset + (1ULL << span) - 1, start);
1920 } else if (*offset < start) {
1921 *offset = start;
1922 }
1923 if (i < 0 || i >= epb)
1924 error = SET_ERROR(ESRCH);
1925 }
1926
1927 if (db)
1928 dbuf_rele(db, FTAG);
1929
1930 return (error);
1931 }
1932
1933 /*
1934 * Find the next hole, data, or sparse region at or after *offset.
1935 * The value 'blkfill' tells us how many items we expect to find
1936 * in an L0 data block; this value is 1 for normal objects,
1937 * DNODES_PER_BLOCK for the meta dnode, and some fraction of
1938 * DNODES_PER_BLOCK when searching for sparse regions thereof.
1939 *
1940 * Examples:
1941 *
1942 * dnode_next_offset(dn, flags, offset, 1, 1, 0);
1943 * Finds the next/previous hole/data in a file.
1944 * Used in dmu_offset_next().
1945 *
1946 * dnode_next_offset(mdn, flags, offset, 0, DNODES_PER_BLOCK, txg);
1947 * Finds the next free/allocated dnode an objset's meta-dnode.
1948 * Only finds objects that have new contents since txg (ie.
1949 * bonus buffer changes and content removal are ignored).
1950 * Used in dmu_object_next().
1951 *
1952 * dnode_next_offset(mdn, DNODE_FIND_HOLE, offset, 2, DNODES_PER_BLOCK >> 2, 0);
1953 * Finds the next L2 meta-dnode bp that's at most 1/4 full.
1954 * Used in dmu_object_alloc().
1955 */
1956 int
1957 dnode_next_offset(dnode_t *dn, int flags, uint64_t *offset,
1958 int minlvl, uint64_t blkfill, uint64_t txg)
1959 {
1960 uint64_t initial_offset = *offset;
1961 int lvl, maxlvl;
1962 int error = 0;
1963
1964 if (!(flags & DNODE_FIND_HAVELOCK))
1965 rw_enter(&dn->dn_struct_rwlock, RW_READER);
1966
1967 if (dn->dn_phys->dn_nlevels == 0) {
1968 error = SET_ERROR(ESRCH);
1969 goto out;
1970 }
1971
1972 if (dn->dn_datablkshift == 0) {
1973 if (*offset < dn->dn_datablksz) {
1974 if (flags & DNODE_FIND_HOLE)
1975 *offset = dn->dn_datablksz;
1976 } else {
1977 error = SET_ERROR(ESRCH);
1978 }
1979 goto out;
1980 }
1981
1982 maxlvl = dn->dn_phys->dn_nlevels;
1983
1984 for (lvl = minlvl; lvl <= maxlvl; lvl++) {
1985 error = dnode_next_offset_level(dn,
1986 flags, offset, lvl, blkfill, txg);
1987 if (error != ESRCH)
1988 break;
1989 }
1990
1991 while (error == 0 && --lvl >= minlvl) {
1992 error = dnode_next_offset_level(dn,
1993 flags, offset, lvl, blkfill, txg);
1994 }
1995
1996 if (error == 0 && (flags & DNODE_FIND_BACKWARDS ?
1997 initial_offset < *offset : initial_offset > *offset))
1998 error = SET_ERROR(ESRCH);
1999 out:
2000 if (!(flags & DNODE_FIND_HAVELOCK))
2001 rw_exit(&dn->dn_struct_rwlock);
2002
2003 return (error);
2004 }