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