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9166 zfs storage pool checkpoint
[unleashed.git] / usr / src / uts / common / fs / zfs / dnode.c
blobaa00acec8e243dc84d661c3dd4d3613e91b17ae5
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, 2017 by Delphix. All rights reserved.
24 * Copyright (c) 2014 Spectra Logic Corporation, All rights reserved.
25 * Copyright (c) 2014 Integros [integros.com]
26 * Copyright 2017 RackTop Systems.
27 */
28
29 #include <sys/zfs_context.h>
30 #include <sys/dbuf.h>
31 #include <sys/dnode.h>
32 #include <sys/dmu.h>
33 #include <sys/dmu_impl.h>
34 #include <sys/dmu_tx.h>
35 #include <sys/dmu_objset.h>
36 #include <sys/dsl_dir.h>
37 #include <sys/dsl_dataset.h>
38 #include <sys/spa.h>
39 #include <sys/zio.h>
40 #include <sys/dmu_zfetch.h>
41 #include <sys/range_tree.h>
42
43 static kmem_cache_t *dnode_cache;
44 /*
45 * Define DNODE_STATS to turn on statistic gathering. By default, it is only
46 * turned on when DEBUG is also defined.
47 */
48 #ifdef DEBUG
49 #define DNODE_STATS
50 #endif /* DEBUG */
51
52 #ifdef DNODE_STATS
53 #define DNODE_STAT_ADD(stat) ((stat)++)
54 #else
55 #define DNODE_STAT_ADD(stat) /* nothing */
56 #endif /* DNODE_STATS */
57
58 static dnode_phys_t dnode_phys_zero;
59
60 int zfs_default_bs = SPA_MINBLOCKSHIFT;
61 int zfs_default_ibs = DN_MAX_INDBLKSHIFT;
62
63 #ifdef _KERNEL
64 static kmem_cbrc_t dnode_move(void *, void *, size_t, void *);
65 #endif /* _KERNEL */
66
67 static int
68 dbuf_compare(const void *x1, const void *x2)
69 {
70 const dmu_buf_impl_t *d1 = x1;
71 const dmu_buf_impl_t *d2 = x2;
72
73 if (d1->db_level < d2->db_level) {
74 return (-1);
75 }
76 if (d1->db_level > d2->db_level) {
77 return (1);
78 }
79
80 if (d1->db_blkid < d2->db_blkid) {
81 return (-1);
82 }
83 if (d1->db_blkid > d2->db_blkid) {
84 return (1);
85 }
86
87 if (d1->db_state == DB_SEARCH) {
88 ASSERT3S(d2->db_state, !=, DB_SEARCH);
89 return (-1);
90 } else if (d2->db_state == DB_SEARCH) {
91 ASSERT3S(d1->db_state, !=, DB_SEARCH);
92 return (1);
93 }
94
95 if ((uintptr_t)d1 < (uintptr_t)d2) {
96 return (-1);
97 }
98 if ((uintptr_t)d1 > (uintptr_t)d2) {
99 return (1);
100 }
101 return (0);
102 }
103
104 /* ARGSUSED */
105 static int
106 dnode_cons(void *arg, void *unused, int kmflag)
107 {
108 dnode_t *dn = arg;
109 int i;
110
111 rw_init(&dn->dn_struct_rwlock, NULL, RW_DEFAULT, NULL);
112 mutex_init(&dn->dn_mtx, NULL, MUTEX_DEFAULT, NULL);
113 mutex_init(&dn->dn_dbufs_mtx, NULL, MUTEX_DEFAULT, NULL);
114 cv_init(&dn->dn_notxholds, NULL, CV_DEFAULT, NULL);
115
116 /*
117 * Every dbuf has a reference, and dropping a tracked reference is
118 * O(number of references), so don't track dn_holds.
119 */
120 refcount_create_untracked(&dn->dn_holds);
121 refcount_create(&dn->dn_tx_holds);
122 list_link_init(&dn->dn_link);
123
124 bzero(&dn->dn_next_nblkptr[0], sizeof (dn->dn_next_nblkptr));
125 bzero(&dn->dn_next_nlevels[0], sizeof (dn->dn_next_nlevels));
126 bzero(&dn->dn_next_indblkshift[0], sizeof (dn->dn_next_indblkshift));
127 bzero(&dn->dn_next_bonustype[0], sizeof (dn->dn_next_bonustype));
128 bzero(&dn->dn_rm_spillblk[0], sizeof (dn->dn_rm_spillblk));
129 bzero(&dn->dn_next_bonuslen[0], sizeof (dn->dn_next_bonuslen));
130 bzero(&dn->dn_next_blksz[0], sizeof (dn->dn_next_blksz));
131
132 for (i = 0; i < TXG_SIZE; i++) {
133 list_link_init(&dn->dn_dirty_link[i]);
134 dn->dn_free_ranges[i] = NULL;
135 list_create(&dn->dn_dirty_records[i],
136 sizeof (dbuf_dirty_record_t),
137 offsetof(dbuf_dirty_record_t, dr_dirty_node));
138 }
139
140 dn->dn_allocated_txg = 0;
141 dn->dn_free_txg = 0;
142 dn->dn_assigned_txg = 0;
143 dn->dn_dirtyctx = 0;
144 dn->dn_dirtyctx_firstset = NULL;
145 dn->dn_bonus = NULL;
146 dn->dn_have_spill = B_FALSE;
147 dn->dn_zio = NULL;
148 dn->dn_oldused = 0;
149 dn->dn_oldflags = 0;
150 dn->dn_olduid = 0;
151 dn->dn_oldgid = 0;
152 dn->dn_newuid = 0;
153 dn->dn_newgid = 0;
154 dn->dn_id_flags = 0;
155
156 dn->dn_dbufs_count = 0;
157 avl_create(&dn->dn_dbufs, dbuf_compare, sizeof (dmu_buf_impl_t),
158 offsetof(dmu_buf_impl_t, db_link));
159
160 dn->dn_moved = 0;
161 return (0);
162 }
163
164 /* ARGSUSED */
165 static void
166 dnode_dest(void *arg, void *unused)
167 {
168 int i;
169 dnode_t *dn = arg;
170
171 rw_destroy(&dn->dn_struct_rwlock);
172 mutex_destroy(&dn->dn_mtx);
173 mutex_destroy(&dn->dn_dbufs_mtx);
174 cv_destroy(&dn->dn_notxholds);
175 refcount_destroy(&dn->dn_holds);
176 refcount_destroy(&dn->dn_tx_holds);
177 ASSERT(!list_link_active(&dn->dn_link));
178
179 for (i = 0; i < TXG_SIZE; i++) {
180 ASSERT(!list_link_active(&dn->dn_dirty_link[i]));
181 ASSERT3P(dn->dn_free_ranges[i], ==, NULL);
182 list_destroy(&dn->dn_dirty_records[i]);
183 ASSERT0(dn->dn_next_nblkptr[i]);
184 ASSERT0(dn->dn_next_nlevels[i]);
185 ASSERT0(dn->dn_next_indblkshift[i]);
186 ASSERT0(dn->dn_next_bonustype[i]);
187 ASSERT0(dn->dn_rm_spillblk[i]);
188 ASSERT0(dn->dn_next_bonuslen[i]);
189 ASSERT0(dn->dn_next_blksz[i]);
190 }
191
192 ASSERT0(dn->dn_allocated_txg);
193 ASSERT0(dn->dn_free_txg);
194 ASSERT0(dn->dn_assigned_txg);
195 ASSERT0(dn->dn_dirtyctx);
196 ASSERT3P(dn->dn_dirtyctx_firstset, ==, NULL);
197 ASSERT3P(dn->dn_bonus, ==, NULL);
198 ASSERT(!dn->dn_have_spill);
199 ASSERT3P(dn->dn_zio, ==, NULL);
200 ASSERT0(dn->dn_oldused);
201 ASSERT0(dn->dn_oldflags);
202 ASSERT0(dn->dn_olduid);
203 ASSERT0(dn->dn_oldgid);
204 ASSERT0(dn->dn_newuid);
205 ASSERT0(dn->dn_newgid);
206 ASSERT0(dn->dn_id_flags);
207
208 ASSERT0(dn->dn_dbufs_count);
209 avl_destroy(&dn->dn_dbufs);
210 }
211
212 void
213 dnode_init(void)
214 {
215 ASSERT(dnode_cache == NULL);
216 dnode_cache = kmem_cache_create("dnode_t",
217 sizeof (dnode_t),
218 0, dnode_cons, dnode_dest, NULL, NULL, NULL, 0);
219 #ifdef _KERNEL
220 kmem_cache_set_move(dnode_cache, dnode_move);
221 #endif /* _KERNEL */
222 }
223
224 void
225 dnode_fini(void)
226 {
227 kmem_cache_destroy(dnode_cache);
228 dnode_cache = NULL;
229 }
230
231
232 #ifdef ZFS_DEBUG
233 void
234 dnode_verify(dnode_t *dn)
235 {
236 int drop_struct_lock = FALSE;
237
238 ASSERT(dn->dn_phys);
239 ASSERT(dn->dn_objset);
240 ASSERT(dn->dn_handle->dnh_dnode == dn);
241
242 ASSERT(DMU_OT_IS_VALID(dn->dn_phys->dn_type));
243
244 if (!(zfs_flags & ZFS_DEBUG_DNODE_VERIFY))
245 return;
246
247 if (!RW_WRITE_HELD(&dn->dn_struct_rwlock)) {
248 rw_enter(&dn->dn_struct_rwlock, RW_READER);
249 drop_struct_lock = TRUE;
250 }
251 if (dn->dn_phys->dn_type != DMU_OT_NONE || dn->dn_allocated_txg != 0) {
252 int i;
253 ASSERT3U(dn->dn_indblkshift, >=, 0);
254 ASSERT3U(dn->dn_indblkshift, <=, SPA_MAXBLOCKSHIFT);
255 if (dn->dn_datablkshift) {
256 ASSERT3U(dn->dn_datablkshift, >=, SPA_MINBLOCKSHIFT);
257 ASSERT3U(dn->dn_datablkshift, <=, SPA_MAXBLOCKSHIFT);
258 ASSERT3U(1<<dn->dn_datablkshift, ==, dn->dn_datablksz);
259 }
260 ASSERT3U(dn->dn_nlevels, <=, 30);
261 ASSERT(DMU_OT_IS_VALID(dn->dn_type));
262 ASSERT3U(dn->dn_nblkptr, >=, 1);
263 ASSERT3U(dn->dn_nblkptr, <=, DN_MAX_NBLKPTR);
264 ASSERT3U(dn->dn_bonuslen, <=, DN_MAX_BONUSLEN);
265 ASSERT3U(dn->dn_datablksz, ==,
266 dn->dn_datablkszsec << SPA_MINBLOCKSHIFT);
267 ASSERT3U(ISP2(dn->dn_datablksz), ==, dn->dn_datablkshift != 0);
268 ASSERT3U((dn->dn_nblkptr - 1) * sizeof (blkptr_t) +
269 dn->dn_bonuslen, <=, DN_MAX_BONUSLEN);
270 for (i = 0; i < TXG_SIZE; i++) {
271 ASSERT3U(dn->dn_next_nlevels[i], <=, dn->dn_nlevels);
272 }
273 }
274 if (dn->dn_phys->dn_type != DMU_OT_NONE)
275 ASSERT3U(dn->dn_phys->dn_nlevels, <=, dn->dn_nlevels);
276 ASSERT(DMU_OBJECT_IS_SPECIAL(dn->dn_object) || dn->dn_dbuf != NULL);
277 if (dn->dn_dbuf != NULL) {
278 ASSERT3P(dn->dn_phys, ==,
279 (dnode_phys_t *)dn->dn_dbuf->db.db_data +
280 (dn->dn_object % (dn->dn_dbuf->db.db_size >> DNODE_SHIFT)));
281 }
282 if (drop_struct_lock)
283 rw_exit(&dn->dn_struct_rwlock);
284 }
285 #endif
286
287 void
288 dnode_byteswap(dnode_phys_t *dnp)
289 {
290 uint64_t *buf64 = (void*)&dnp->dn_blkptr;
291 int i;
292
293 if (dnp->dn_type == DMU_OT_NONE) {
294 bzero(dnp, sizeof (dnode_phys_t));
295 return;
296 }
297
298 dnp->dn_datablkszsec = BSWAP_16(dnp->dn_datablkszsec);
299 dnp->dn_bonuslen = BSWAP_16(dnp->dn_bonuslen);
300 dnp->dn_maxblkid = BSWAP_64(dnp->dn_maxblkid);
301 dnp->dn_used = BSWAP_64(dnp->dn_used);
302
303 /*
304 * dn_nblkptr is only one byte, so it's OK to read it in either
305 * byte order. We can't read dn_bouslen.
306 */
307 ASSERT(dnp->dn_indblkshift <= SPA_MAXBLOCKSHIFT);
308 ASSERT(dnp->dn_nblkptr <= DN_MAX_NBLKPTR);
309 for (i = 0; i < dnp->dn_nblkptr * sizeof (blkptr_t)/8; i++)
310 buf64[i] = BSWAP_64(buf64[i]);
311
312 /*
313 * OK to check dn_bonuslen for zero, because it won't matter if
314 * we have the wrong byte order. This is necessary because the
315 * dnode dnode is smaller than a regular dnode.
316 */
317 if (dnp->dn_bonuslen != 0) {
318 /*
319 * Note that the bonus length calculated here may be
320 * longer than the actual bonus buffer. This is because
321 * we always put the bonus buffer after the last block
322 * pointer (instead of packing it against the end of the
323 * dnode buffer).
324 */
325 int off = (dnp->dn_nblkptr-1) * sizeof (blkptr_t);
326 size_t len = DN_MAX_BONUSLEN - off;
327 ASSERT(DMU_OT_IS_VALID(dnp->dn_bonustype));
328 dmu_object_byteswap_t byteswap =
329 DMU_OT_BYTESWAP(dnp->dn_bonustype);
330 dmu_ot_byteswap[byteswap].ob_func(dnp->dn_bonus + off, len);
331 }
332
333 /* Swap SPILL block if we have one */
334 if (dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR)
335 byteswap_uint64_array(&dnp->dn_spill, sizeof (blkptr_t));
336
337 }
338
339 void
340 dnode_buf_byteswap(void *vbuf, size_t size)
341 {
342 dnode_phys_t *buf = vbuf;
343 int i;
344
345 ASSERT3U(sizeof (dnode_phys_t), ==, (1<<DNODE_SHIFT));
346 ASSERT((size & (sizeof (dnode_phys_t)-1)) == 0);
347
348 size >>= DNODE_SHIFT;
349 for (i = 0; i < size; i++) {
350 dnode_byteswap(buf);
351 buf++;
352 }
353 }
354
355 void
356 dnode_setbonuslen(dnode_t *dn, int newsize, dmu_tx_t *tx)
357 {
358 ASSERT3U(refcount_count(&dn->dn_holds), >=, 1);
359
360 dnode_setdirty(dn, tx);
361 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
362 ASSERT3U(newsize, <=, DN_MAX_BONUSLEN -
363 (dn->dn_nblkptr-1) * sizeof (blkptr_t));
364 dn->dn_bonuslen = newsize;
365 if (newsize == 0)
366 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = DN_ZERO_BONUSLEN;
367 else
368 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = dn->dn_bonuslen;
369 rw_exit(&dn->dn_struct_rwlock);
370 }
371
372 void
373 dnode_setbonus_type(dnode_t *dn, dmu_object_type_t newtype, dmu_tx_t *tx)
374 {
375 ASSERT3U(refcount_count(&dn->dn_holds), >=, 1);
376 dnode_setdirty(dn, tx);
377 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
378 dn->dn_bonustype = newtype;
379 dn->dn_next_bonustype[tx->tx_txg & TXG_MASK] = dn->dn_bonustype;
380 rw_exit(&dn->dn_struct_rwlock);
381 }
382
383 void
384 dnode_rm_spill(dnode_t *dn, dmu_tx_t *tx)
385 {
386 ASSERT3U(refcount_count(&dn->dn_holds), >=, 1);
387 ASSERT(RW_WRITE_HELD(&dn->dn_struct_rwlock));
388 dnode_setdirty(dn, tx);
389 dn->dn_rm_spillblk[tx->tx_txg&TXG_MASK] = DN_KILL_SPILLBLK;
390 dn->dn_have_spill = B_FALSE;
391 }
392
393 static void
394 dnode_setdblksz(dnode_t *dn, int size)
395 {
396 ASSERT0(P2PHASE(size, SPA_MINBLOCKSIZE));
397 ASSERT3U(size, <=, SPA_MAXBLOCKSIZE);
398 ASSERT3U(size, >=, SPA_MINBLOCKSIZE);
399 ASSERT3U(size >> SPA_MINBLOCKSHIFT, <,
400 1<<(sizeof (dn->dn_phys->dn_datablkszsec) * 8));
401 dn->dn_datablksz = size;
402 dn->dn_datablkszsec = size >> SPA_MINBLOCKSHIFT;
403 dn->dn_datablkshift = ISP2(size) ? highbit64(size - 1) : 0;
404 }
405
406 static dnode_t *
407 dnode_create(objset_t *os, dnode_phys_t *dnp, dmu_buf_impl_t *db,
408 uint64_t object, dnode_handle_t *dnh)
409 {
410 dnode_t *dn;
411
412 dn = kmem_cache_alloc(dnode_cache, KM_SLEEP);
413 #ifdef _KERNEL
414 ASSERT(!POINTER_IS_VALID(dn->dn_objset));
415 #endif /* _KERNEL */
416 dn->dn_moved = 0;
417
418 /*
419 * Defer setting dn_objset until the dnode is ready to be a candidate
420 * for the dnode_move() callback.
421 */
422 dn->dn_object = object;
423 dn->dn_dbuf = db;
424 dn->dn_handle = dnh;
425 dn->dn_phys = dnp;
426
427 if (dnp->dn_datablkszsec) {
428 dnode_setdblksz(dn, dnp->dn_datablkszsec << SPA_MINBLOCKSHIFT);
429 } else {
430 dn->dn_datablksz = 0;
431 dn->dn_datablkszsec = 0;
432 dn->dn_datablkshift = 0;
433 }
434 dn->dn_indblkshift = dnp->dn_indblkshift;
435 dn->dn_nlevels = dnp->dn_nlevels;
436 dn->dn_type = dnp->dn_type;
437 dn->dn_nblkptr = dnp->dn_nblkptr;
438 dn->dn_checksum = dnp->dn_checksum;
439 dn->dn_compress = dnp->dn_compress;
440 dn->dn_bonustype = dnp->dn_bonustype;
441 dn->dn_bonuslen = dnp->dn_bonuslen;
442 dn->dn_maxblkid = dnp->dn_maxblkid;
443 dn->dn_have_spill = ((dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) != 0);
444 dn->dn_id_flags = 0;
445
446 dmu_zfetch_init(&dn->dn_zfetch, dn);
447
448 ASSERT(DMU_OT_IS_VALID(dn->dn_phys->dn_type));
449
450 mutex_enter(&os->os_lock);
451 if (dnh->dnh_dnode != NULL) {
452 /* Lost the allocation race. */
453 mutex_exit(&os->os_lock);
454 kmem_cache_free(dnode_cache, dn);
455 return (dnh->dnh_dnode);
456 }
457
458 /*
459 * Exclude special dnodes from os_dnodes so an empty os_dnodes
460 * signifies that the special dnodes have no references from
461 * their children (the entries in os_dnodes). This allows
462 * dnode_destroy() to easily determine if the last child has
463 * been removed and then complete eviction of the objset.
464 */
465 if (!DMU_OBJECT_IS_SPECIAL(object))
466 list_insert_head(&os->os_dnodes, dn);
467 membar_producer();
468
469 /*
470 * Everything else must be valid before assigning dn_objset
471 * makes the dnode eligible for dnode_move().
472 */
473 dn->dn_objset = os;
474
475 dnh->dnh_dnode = dn;
476 mutex_exit(&os->os_lock);
477
478 arc_space_consume(sizeof (dnode_t), ARC_SPACE_OTHER);
479 return (dn);
480 }
481
482 /*
483 * Caller must be holding the dnode handle, which is released upon return.
484 */
485 static void
486 dnode_destroy(dnode_t *dn)
487 {
488 objset_t *os = dn->dn_objset;
489 boolean_t complete_os_eviction = B_FALSE;
490
491 ASSERT((dn->dn_id_flags & DN_ID_NEW_EXIST) == 0);
492
493 mutex_enter(&os->os_lock);
494 POINTER_INVALIDATE(&dn->dn_objset);
495 if (!DMU_OBJECT_IS_SPECIAL(dn->dn_object)) {
496 list_remove(&os->os_dnodes, dn);
497 complete_os_eviction =
498 list_is_empty(&os->os_dnodes) &&
499 list_link_active(&os->os_evicting_node);
500 }
501 mutex_exit(&os->os_lock);
502
503 /* the dnode can no longer move, so we can release the handle */
504 zrl_remove(&dn->dn_handle->dnh_zrlock);
505
506 dn->dn_allocated_txg = 0;
507 dn->dn_free_txg = 0;
508 dn->dn_assigned_txg = 0;
509
510 dn->dn_dirtyctx = 0;
511 if (dn->dn_dirtyctx_firstset != NULL) {
512 kmem_free(dn->dn_dirtyctx_firstset, 1);
513 dn->dn_dirtyctx_firstset = NULL;
514 }
515 if (dn->dn_bonus != NULL) {
516 mutex_enter(&dn->dn_bonus->db_mtx);
517 dbuf_destroy(dn->dn_bonus);
518 dn->dn_bonus = NULL;
519 }
520 dn->dn_zio = NULL;
521
522 dn->dn_have_spill = B_FALSE;
523 dn->dn_oldused = 0;
524 dn->dn_oldflags = 0;
525 dn->dn_olduid = 0;
526 dn->dn_oldgid = 0;
527 dn->dn_newuid = 0;
528 dn->dn_newgid = 0;
529 dn->dn_id_flags = 0;
530
531 dmu_zfetch_fini(&dn->dn_zfetch);
532 kmem_cache_free(dnode_cache, dn);
533 arc_space_return(sizeof (dnode_t), ARC_SPACE_OTHER);
534
535 if (complete_os_eviction)
536 dmu_objset_evict_done(os);
537 }
538
539 void
540 dnode_allocate(dnode_t *dn, dmu_object_type_t ot, int blocksize, int ibs,
541 dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx)
542 {
543 int i;
544
545 ASSERT3U(blocksize, <=,
546 spa_maxblocksize(dmu_objset_spa(dn->dn_objset)));
547 if (blocksize == 0)
548 blocksize = 1 << zfs_default_bs;
549 else
550 blocksize = P2ROUNDUP(blocksize, SPA_MINBLOCKSIZE);
551
552 if (ibs == 0)
553 ibs = zfs_default_ibs;
554
555 ibs = MIN(MAX(ibs, DN_MIN_INDBLKSHIFT), DN_MAX_INDBLKSHIFT);
556
557 dprintf("os=%p obj=%llu txg=%llu blocksize=%d ibs=%d\n", dn->dn_objset,
558 dn->dn_object, tx->tx_txg, blocksize, ibs);
559
560 ASSERT(dn->dn_type == DMU_OT_NONE);
561 ASSERT(bcmp(dn->dn_phys, &dnode_phys_zero, sizeof (dnode_phys_t)) == 0);
562 ASSERT(dn->dn_phys->dn_type == DMU_OT_NONE);
563 ASSERT(ot != DMU_OT_NONE);
564 ASSERT(DMU_OT_IS_VALID(ot));
565 ASSERT((bonustype == DMU_OT_NONE && bonuslen == 0) ||
566 (bonustype == DMU_OT_SA && bonuslen == 0) ||
567 (bonustype != DMU_OT_NONE && bonuslen != 0));
568 ASSERT(DMU_OT_IS_VALID(bonustype));
569 ASSERT3U(bonuslen, <=, DN_MAX_BONUSLEN);
570 ASSERT(dn->dn_type == DMU_OT_NONE);
571 ASSERT0(dn->dn_maxblkid);
572 ASSERT0(dn->dn_allocated_txg);
573 ASSERT0(dn->dn_assigned_txg);
574 ASSERT(refcount_is_zero(&dn->dn_tx_holds));
575 ASSERT3U(refcount_count(&dn->dn_holds), <=, 1);
576 ASSERT(avl_is_empty(&dn->dn_dbufs));
577
578 for (i = 0; i < TXG_SIZE; i++) {
579 ASSERT0(dn->dn_next_nblkptr[i]);
580 ASSERT0(dn->dn_next_nlevels[i]);
581 ASSERT0(dn->dn_next_indblkshift[i]);
582 ASSERT0(dn->dn_next_bonuslen[i]);
583 ASSERT0(dn->dn_next_bonustype[i]);
584 ASSERT0(dn->dn_rm_spillblk[i]);
585 ASSERT0(dn->dn_next_blksz[i]);
586 ASSERT(!list_link_active(&dn->dn_dirty_link[i]));
587 ASSERT3P(list_head(&dn->dn_dirty_records[i]), ==, NULL);
588 ASSERT3P(dn->dn_free_ranges[i], ==, NULL);
589 }
590
591 dn->dn_type = ot;
592 dnode_setdblksz(dn, blocksize);
593 dn->dn_indblkshift = ibs;
594 dn->dn_nlevels = 1;
595 if (bonustype == DMU_OT_SA) /* Maximize bonus space for SA */
596 dn->dn_nblkptr = 1;
597 else
598 dn->dn_nblkptr = 1 +
599 ((DN_MAX_BONUSLEN - bonuslen) >> SPA_BLKPTRSHIFT);
600 dn->dn_bonustype = bonustype;
601 dn->dn_bonuslen = bonuslen;
602 dn->dn_checksum = ZIO_CHECKSUM_INHERIT;
603 dn->dn_compress = ZIO_COMPRESS_INHERIT;
604 dn->dn_dirtyctx = 0;
605
606 dn->dn_free_txg = 0;
607 if (dn->dn_dirtyctx_firstset) {
608 kmem_free(dn->dn_dirtyctx_firstset, 1);
609 dn->dn_dirtyctx_firstset = NULL;
610 }
611
612 dn->dn_allocated_txg = tx->tx_txg;
613 dn->dn_id_flags = 0;
614
615 dnode_setdirty(dn, tx);
616 dn->dn_next_indblkshift[tx->tx_txg & TXG_MASK] = ibs;
617 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = dn->dn_bonuslen;
618 dn->dn_next_bonustype[tx->tx_txg & TXG_MASK] = dn->dn_bonustype;
619 dn->dn_next_blksz[tx->tx_txg & TXG_MASK] = dn->dn_datablksz;
620 }
621
622 void
623 dnode_reallocate(dnode_t *dn, dmu_object_type_t ot, int blocksize,
624 dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx)
625 {
626 int nblkptr;
627
628 ASSERT3U(blocksize, >=, SPA_MINBLOCKSIZE);
629 ASSERT3U(blocksize, <=,
630 spa_maxblocksize(dmu_objset_spa(dn->dn_objset)));
631 ASSERT0(blocksize % SPA_MINBLOCKSIZE);
632 ASSERT(dn->dn_object != DMU_META_DNODE_OBJECT || dmu_tx_private_ok(tx));
633 ASSERT(tx->tx_txg != 0);
634 ASSERT((bonustype == DMU_OT_NONE && bonuslen == 0) ||
635 (bonustype != DMU_OT_NONE && bonuslen != 0) ||
636 (bonustype == DMU_OT_SA && bonuslen == 0));
637 ASSERT(DMU_OT_IS_VALID(bonustype));
638 ASSERT3U(bonuslen, <=, DN_MAX_BONUSLEN);
639
640 /* clean up any unreferenced dbufs */
641 dnode_evict_dbufs(dn);
642
643 dn->dn_id_flags = 0;
644
645 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
646 dnode_setdirty(dn, tx);
647 if (dn->dn_datablksz != blocksize) {
648 /* change blocksize */
649 ASSERT(dn->dn_maxblkid == 0 &&
650 (BP_IS_HOLE(&dn->dn_phys->dn_blkptr[0]) ||
651 dnode_block_freed(dn, 0)));
652 dnode_setdblksz(dn, blocksize);
653 dn->dn_next_blksz[tx->tx_txg&TXG_MASK] = blocksize;
654 }
655 if (dn->dn_bonuslen != bonuslen)
656 dn->dn_next_bonuslen[tx->tx_txg&TXG_MASK] = bonuslen;
657
658 if (bonustype == DMU_OT_SA) /* Maximize bonus space for SA */
659 nblkptr = 1;
660 else
661 nblkptr = 1 + ((DN_MAX_BONUSLEN - bonuslen) >> SPA_BLKPTRSHIFT);
662 if (dn->dn_bonustype != bonustype)
663 dn->dn_next_bonustype[tx->tx_txg&TXG_MASK] = bonustype;
664 if (dn->dn_nblkptr != nblkptr)
665 dn->dn_next_nblkptr[tx->tx_txg&TXG_MASK] = nblkptr;
666 if (dn->dn_phys->dn_flags & DNODE_FLAG_SPILL_BLKPTR) {
667 dbuf_rm_spill(dn, tx);
668 dnode_rm_spill(dn, tx);
669 }
670 rw_exit(&dn->dn_struct_rwlock);
671
672 /* change type */
673 dn->dn_type = ot;
674
675 /* change bonus size and type */
676 mutex_enter(&dn->dn_mtx);
677 dn->dn_bonustype = bonustype;
678 dn->dn_bonuslen = bonuslen;
679 dn->dn_nblkptr = nblkptr;
680 dn->dn_checksum = ZIO_CHECKSUM_INHERIT;
681 dn->dn_compress = ZIO_COMPRESS_INHERIT;
682 ASSERT3U(dn->dn_nblkptr, <=, DN_MAX_NBLKPTR);
683
684 /* fix up the bonus db_size */
685 if (dn->dn_bonus) {
686 dn->dn_bonus->db.db_size =
687 DN_MAX_BONUSLEN - (dn->dn_nblkptr-1) * sizeof (blkptr_t);
688 ASSERT(dn->dn_bonuslen <= dn->dn_bonus->db.db_size);
689 }
690
691 dn->dn_allocated_txg = tx->tx_txg;
692 mutex_exit(&dn->dn_mtx);
693 }
694
695 #ifdef DNODE_STATS
696 static struct {
697 uint64_t dms_dnode_invalid;
698 uint64_t dms_dnode_recheck1;
699 uint64_t dms_dnode_recheck2;
700 uint64_t dms_dnode_special;
701 uint64_t dms_dnode_handle;
702 uint64_t dms_dnode_rwlock;
703 uint64_t dms_dnode_active;
704 } dnode_move_stats;
705 #endif /* DNODE_STATS */
706
707 #ifdef _KERNEL
708 static void
709 dnode_move_impl(dnode_t *odn, dnode_t *ndn)
710 {
711 int i;
712
713 ASSERT(!RW_LOCK_HELD(&odn->dn_struct_rwlock));
714 ASSERT(MUTEX_NOT_HELD(&odn->dn_mtx));
715 ASSERT(MUTEX_NOT_HELD(&odn->dn_dbufs_mtx));
716 ASSERT(!RW_LOCK_HELD(&odn->dn_zfetch.zf_rwlock));
717
718 /* Copy fields. */
719 ndn->dn_objset = odn->dn_objset;
720 ndn->dn_object = odn->dn_object;
721 ndn->dn_dbuf = odn->dn_dbuf;
722 ndn->dn_handle = odn->dn_handle;
723 ndn->dn_phys = odn->dn_phys;
724 ndn->dn_type = odn->dn_type;
725 ndn->dn_bonuslen = odn->dn_bonuslen;
726 ndn->dn_bonustype = odn->dn_bonustype;
727 ndn->dn_nblkptr = odn->dn_nblkptr;
728 ndn->dn_checksum = odn->dn_checksum;
729 ndn->dn_compress = odn->dn_compress;
730 ndn->dn_nlevels = odn->dn_nlevels;
731 ndn->dn_indblkshift = odn->dn_indblkshift;
732 ndn->dn_datablkshift = odn->dn_datablkshift;
733 ndn->dn_datablkszsec = odn->dn_datablkszsec;
734 ndn->dn_datablksz = odn->dn_datablksz;
735 ndn->dn_maxblkid = odn->dn_maxblkid;
736 bcopy(&odn->dn_next_nblkptr[0], &ndn->dn_next_nblkptr[0],
737 sizeof (odn->dn_next_nblkptr));
738 bcopy(&odn->dn_next_nlevels[0], &ndn->dn_next_nlevels[0],
739 sizeof (odn->dn_next_nlevels));
740 bcopy(&odn->dn_next_indblkshift[0], &ndn->dn_next_indblkshift[0],
741 sizeof (odn->dn_next_indblkshift));
742 bcopy(&odn->dn_next_bonustype[0], &ndn->dn_next_bonustype[0],
743 sizeof (odn->dn_next_bonustype));
744 bcopy(&odn->dn_rm_spillblk[0], &ndn->dn_rm_spillblk[0],
745 sizeof (odn->dn_rm_spillblk));
746 bcopy(&odn->dn_next_bonuslen[0], &ndn->dn_next_bonuslen[0],
747 sizeof (odn->dn_next_bonuslen));
748 bcopy(&odn->dn_next_blksz[0], &ndn->dn_next_blksz[0],
749 sizeof (odn->dn_next_blksz));
750 for (i = 0; i < TXG_SIZE; i++) {
751 list_move_tail(&ndn->dn_dirty_records[i],
752 &odn->dn_dirty_records[i]);
753 }
754 bcopy(&odn->dn_free_ranges[0], &ndn->dn_free_ranges[0],
755 sizeof (odn->dn_free_ranges));
756 ndn->dn_allocated_txg = odn->dn_allocated_txg;
757 ndn->dn_free_txg = odn->dn_free_txg;
758 ndn->dn_assigned_txg = odn->dn_assigned_txg;
759 ndn->dn_dirtyctx = odn->dn_dirtyctx;
760 ndn->dn_dirtyctx_firstset = odn->dn_dirtyctx_firstset;
761 ASSERT(refcount_count(&odn->dn_tx_holds) == 0);
762 refcount_transfer(&ndn->dn_holds, &odn->dn_holds);
763 ASSERT(avl_is_empty(&ndn->dn_dbufs));
764 avl_swap(&ndn->dn_dbufs, &odn->dn_dbufs);
765 ndn->dn_dbufs_count = odn->dn_dbufs_count;
766 ndn->dn_bonus = odn->dn_bonus;
767 ndn->dn_have_spill = odn->dn_have_spill;
768 ndn->dn_zio = odn->dn_zio;
769 ndn->dn_oldused = odn->dn_oldused;
770 ndn->dn_oldflags = odn->dn_oldflags;
771 ndn->dn_olduid = odn->dn_olduid;
772 ndn->dn_oldgid = odn->dn_oldgid;
773 ndn->dn_newuid = odn->dn_newuid;
774 ndn->dn_newgid = odn->dn_newgid;
775 ndn->dn_id_flags = odn->dn_id_flags;
776 dmu_zfetch_init(&ndn->dn_zfetch, NULL);
777 list_move_tail(&ndn->dn_zfetch.zf_stream, &odn->dn_zfetch.zf_stream);
778 ndn->dn_zfetch.zf_dnode = odn->dn_zfetch.zf_dnode;
779
780 /*
781 * Update back pointers. Updating the handle fixes the back pointer of
782 * every descendant dbuf as well as the bonus dbuf.
783 */
784 ASSERT(ndn->dn_handle->dnh_dnode == odn);
785 ndn->dn_handle->dnh_dnode = ndn;
786 if (ndn->dn_zfetch.zf_dnode == odn) {
787 ndn->dn_zfetch.zf_dnode = ndn;
788 }
789
790 /*
791 * Invalidate the original dnode by clearing all of its back pointers.
792 */
793 odn->dn_dbuf = NULL;
794 odn->dn_handle = NULL;
795 avl_create(&odn->dn_dbufs, dbuf_compare, sizeof (dmu_buf_impl_t),
796 offsetof(dmu_buf_impl_t, db_link));
797 odn->dn_dbufs_count = 0;
798 odn->dn_bonus = NULL;
799 odn->dn_zfetch.zf_dnode = NULL;
800
801 /*
802 * Set the low bit of the objset pointer to ensure that dnode_move()
803 * recognizes the dnode as invalid in any subsequent callback.
804 */
805 POINTER_INVALIDATE(&odn->dn_objset);
806
807 /*
808 * Satisfy the destructor.
809 */
810 for (i = 0; i < TXG_SIZE; i++) {
811 list_create(&odn->dn_dirty_records[i],
812 sizeof (dbuf_dirty_record_t),
813 offsetof(dbuf_dirty_record_t, dr_dirty_node));
814 odn->dn_free_ranges[i] = NULL;
815 odn->dn_next_nlevels[i] = 0;
816 odn->dn_next_indblkshift[i] = 0;
817 odn->dn_next_bonustype[i] = 0;
818 odn->dn_rm_spillblk[i] = 0;
819 odn->dn_next_bonuslen[i] = 0;
820 odn->dn_next_blksz[i] = 0;
821 }
822 odn->dn_allocated_txg = 0;
823 odn->dn_free_txg = 0;
824 odn->dn_assigned_txg = 0;
825 odn->dn_dirtyctx = 0;
826 odn->dn_dirtyctx_firstset = NULL;
827 odn->dn_have_spill = B_FALSE;
828 odn->dn_zio = NULL;
829 odn->dn_oldused = 0;
830 odn->dn_oldflags = 0;
831 odn->dn_olduid = 0;
832 odn->dn_oldgid = 0;
833 odn->dn_newuid = 0;
834 odn->dn_newgid = 0;
835 odn->dn_id_flags = 0;
836
837 /*
838 * Mark the dnode.
839 */
840 ndn->dn_moved = 1;
841 odn->dn_moved = (uint8_t)-1;
842 }
843
844 /*ARGSUSED*/
845 static kmem_cbrc_t
846 dnode_move(void *buf, void *newbuf, size_t size, void *arg)
847 {
848 dnode_t *odn = buf, *ndn = newbuf;
849 objset_t *os;
850 int64_t refcount;
851 uint32_t dbufs;
852
853 /*
854 * The dnode is on the objset's list of known dnodes if the objset
855 * pointer is valid. We set the low bit of the objset pointer when
856 * freeing the dnode to invalidate it, and the memory patterns written
857 * by kmem (baddcafe and deadbeef) set at least one of the two low bits.
858 * A newly created dnode sets the objset pointer last of all to indicate
859 * that the dnode is known and in a valid state to be moved by this
860 * function.
861 */
862 os = odn->dn_objset;
863 if (!POINTER_IS_VALID(os)) {
864 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_invalid);
865 return (KMEM_CBRC_DONT_KNOW);
866 }
867
868 /*
869 * Ensure that the objset does not go away during the move.
870 */
871 rw_enter(&os_lock, RW_WRITER);
872 if (os != odn->dn_objset) {
873 rw_exit(&os_lock);
874 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_recheck1);
875 return (KMEM_CBRC_DONT_KNOW);
876 }
877
878 /*
879 * If the dnode is still valid, then so is the objset. We know that no
880 * valid objset can be freed while we hold os_lock, so we can safely
881 * ensure that the objset remains in use.
882 */
883 mutex_enter(&os->os_lock);
884
885 /*
886 * Recheck the objset pointer in case the dnode was removed just before
887 * acquiring the lock.
888 */
889 if (os != odn->dn_objset) {
890 mutex_exit(&os->os_lock);
891 rw_exit(&os_lock);
892 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_recheck2);
893 return (KMEM_CBRC_DONT_KNOW);
894 }
895
896 /*
897 * At this point we know that as long as we hold os->os_lock, the dnode
898 * cannot be freed and fields within the dnode can be safely accessed.
899 * The objset listing this dnode cannot go away as long as this dnode is
900 * on its list.
901 */
902 rw_exit(&os_lock);
903 if (DMU_OBJECT_IS_SPECIAL(odn->dn_object)) {
904 mutex_exit(&os->os_lock);
905 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_special);
906 return (KMEM_CBRC_NO);
907 }
908 ASSERT(odn->dn_dbuf != NULL); /* only "special" dnodes have no parent */
909
910 /*
911 * Lock the dnode handle to prevent the dnode from obtaining any new
912 * holds. This also prevents the descendant dbufs and the bonus dbuf
913 * from accessing the dnode, so that we can discount their holds. The
914 * handle is safe to access because we know that while the dnode cannot
915 * go away, neither can its handle. Once we hold dnh_zrlock, we can
916 * safely move any dnode referenced only by dbufs.
917 */
918 if (!zrl_tryenter(&odn->dn_handle->dnh_zrlock)) {
919 mutex_exit(&os->os_lock);
920 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_handle);
921 return (KMEM_CBRC_LATER);
922 }
923
924 /*
925 * Ensure a consistent view of the dnode's holds and the dnode's dbufs.
926 * We need to guarantee that there is a hold for every dbuf in order to
927 * determine whether the dnode is actively referenced. Falsely matching
928 * a dbuf to an active hold would lead to an unsafe move. It's possible
929 * that a thread already having an active dnode hold is about to add a
930 * dbuf, and we can't compare hold and dbuf counts while the add is in
931 * progress.
932 */
933 if (!rw_tryenter(&odn->dn_struct_rwlock, RW_WRITER)) {
934 zrl_exit(&odn->dn_handle->dnh_zrlock);
935 mutex_exit(&os->os_lock);
936 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_rwlock);
937 return (KMEM_CBRC_LATER);
938 }
939
940 /*
941 * A dbuf may be removed (evicted) without an active dnode hold. In that
942 * case, the dbuf count is decremented under the handle lock before the
943 * dbuf's hold is released. This order ensures that if we count the hold
944 * after the dbuf is removed but before its hold is released, we will
945 * treat the unmatched hold as active and exit safely. If we count the
946 * hold before the dbuf is removed, the hold is discounted, and the
947 * removal is blocked until the move completes.
948 */
949 refcount = refcount_count(&odn->dn_holds);
950 ASSERT(refcount >= 0);
951 dbufs = odn->dn_dbufs_count;
952
953 /* We can't have more dbufs than dnode holds. */
954 ASSERT3U(dbufs, <=, refcount);
955 DTRACE_PROBE3(dnode__move, dnode_t *, odn, int64_t, refcount,
956 uint32_t, dbufs);
957
958 if (refcount > dbufs) {
959 rw_exit(&odn->dn_struct_rwlock);
960 zrl_exit(&odn->dn_handle->dnh_zrlock);
961 mutex_exit(&os->os_lock);
962 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_active);
963 return (KMEM_CBRC_LATER);
964 }
965
966 rw_exit(&odn->dn_struct_rwlock);
967
968 /*
969 * At this point we know that anyone with a hold on the dnode is not
970 * actively referencing it. The dnode is known and in a valid state to
971 * move. We're holding the locks needed to execute the critical section.
972 */
973 dnode_move_impl(odn, ndn);
974
975 list_link_replace(&odn->dn_link, &ndn->dn_link);
976 /* If the dnode was safe to move, the refcount cannot have changed. */
977 ASSERT(refcount == refcount_count(&ndn->dn_holds));
978 ASSERT(dbufs == ndn->dn_dbufs_count);
979 zrl_exit(&ndn->dn_handle->dnh_zrlock); /* handle has moved */
980 mutex_exit(&os->os_lock);
981
982 return (KMEM_CBRC_YES);
983 }
984 #endif /* _KERNEL */
985
986 void
987 dnode_special_close(dnode_handle_t *dnh)
988 {
989 dnode_t *dn = dnh->dnh_dnode;
990
991 /*
992 * Wait for final references to the dnode to clear. This can
993 * only happen if the arc is asyncronously evicting state that
994 * has a hold on this dnode while we are trying to evict this
995 * dnode.
996 */
997 while (refcount_count(&dn->dn_holds) > 0)
998 delay(1);
999 ASSERT(dn->dn_dbuf == NULL ||
1000 dmu_buf_get_user(&dn->dn_dbuf->db) == NULL);
1001 zrl_add(&dnh->dnh_zrlock);
1002 dnode_destroy(dn); /* implicit zrl_remove() */
1003 zrl_destroy(&dnh->dnh_zrlock);
1004 dnh->dnh_dnode = NULL;
1005 }
1006
1007 void
1008 dnode_special_open(objset_t *os, dnode_phys_t *dnp, uint64_t object,
1009 dnode_handle_t *dnh)
1010 {
1011 dnode_t *dn;
1012
1013 dn = dnode_create(os, dnp, NULL, object, dnh);
1014 zrl_init(&dnh->dnh_zrlock);
1015 DNODE_VERIFY(dn);
1016 }
1017
1018 static void
1019 dnode_buf_evict_async(void *dbu)
1020 {
1021 dnode_children_t *children_dnodes = dbu;
1022 int i;
1023
1024 for (i = 0; i < children_dnodes->dnc_count; i++) {
1025 dnode_handle_t *dnh = &children_dnodes->dnc_children[i];
1026 dnode_t *dn;
1027
1028 /*
1029 * The dnode handle lock guards against the dnode moving to
1030 * another valid address, so there is no need here to guard
1031 * against changes to or from NULL.
1032 */
1033 if (dnh->dnh_dnode == NULL) {
1034 zrl_destroy(&dnh->dnh_zrlock);
1035 continue;
1036 }
1037
1038 zrl_add(&dnh->dnh_zrlock);
1039 dn = dnh->dnh_dnode;
1040 /*
1041 * If there are holds on this dnode, then there should
1042 * be holds on the dnode's containing dbuf as well; thus
1043 * it wouldn't be eligible for eviction and this function
1044 * would not have been called.
1045 */
1046 ASSERT(refcount_is_zero(&dn->dn_holds));
1047 ASSERT(refcount_is_zero(&dn->dn_tx_holds));
1048
1049 dnode_destroy(dn); /* implicit zrl_remove() */
1050 zrl_destroy(&dnh->dnh_zrlock);
1051 dnh->dnh_dnode = NULL;
1052 }
1053 kmem_free(children_dnodes, sizeof (dnode_children_t) +
1054 children_dnodes->dnc_count * sizeof (dnode_handle_t));
1055 }
1056
1057 /*
1058 * errors:
1059 * EINVAL - invalid object number.
1060 * EIO - i/o error.
1061 * succeeds even for free dnodes.
1062 */
1063 int
1064 dnode_hold_impl(objset_t *os, uint64_t object, int flag,
1065 void *tag, dnode_t **dnp)
1066 {
1067 int epb, idx, err;
1068 int drop_struct_lock = FALSE;
1069 int type;
1070 uint64_t blk;
1071 dnode_t *mdn, *dn;
1072 dmu_buf_impl_t *db;
1073 dnode_children_t *children_dnodes;
1074 dnode_handle_t *dnh;
1075
1076 /*
1077 * If you are holding the spa config lock as writer, you shouldn't
1078 * be asking the DMU to do *anything* unless it's the root pool
1079 * which may require us to read from the root filesystem while
1080 * holding some (not all) of the locks as writer.
1081 */
1082 ASSERT(spa_config_held(os->os_spa, SCL_ALL, RW_WRITER) == 0 ||
1083 (spa_is_root(os->os_spa) &&
1084 spa_config_held(os->os_spa, SCL_STATE, RW_WRITER)));
1085
1086 ASSERT((flag & DNODE_MUST_BE_ALLOCATED) || (flag & DNODE_MUST_BE_FREE));
1087
1088 if (object == DMU_USERUSED_OBJECT || object == DMU_GROUPUSED_OBJECT) {
1089 dn = (object == DMU_USERUSED_OBJECT) ?
1090 DMU_USERUSED_DNODE(os) : DMU_GROUPUSED_DNODE(os);
1091 if (dn == NULL)
1092 return (SET_ERROR(ENOENT));
1093 type = dn->dn_type;
1094 if ((flag & DNODE_MUST_BE_ALLOCATED) && type == DMU_OT_NONE)
1095 return (SET_ERROR(ENOENT));
1096 if ((flag & DNODE_MUST_BE_FREE) && type != DMU_OT_NONE)
1097 return (SET_ERROR(EEXIST));
1098 DNODE_VERIFY(dn);
1099 (void) refcount_add(&dn->dn_holds, tag);
1100 *dnp = dn;
1101 return (0);
1102 }
1103
1104 if (object == 0 || object >= DN_MAX_OBJECT)
1105 return (SET_ERROR(EINVAL));
1106
1107 mdn = DMU_META_DNODE(os);
1108 ASSERT(mdn->dn_object == DMU_META_DNODE_OBJECT);
1109
1110 DNODE_VERIFY(mdn);
1111
1112 if (!RW_WRITE_HELD(&mdn->dn_struct_rwlock)) {
1113 rw_enter(&mdn->dn_struct_rwlock, RW_READER);
1114 drop_struct_lock = TRUE;
1115 }
1116
1117 blk = dbuf_whichblock(mdn, 0, object * sizeof (dnode_phys_t));
1118
1119 db = dbuf_hold(mdn, blk, FTAG);
1120 if (drop_struct_lock)
1121 rw_exit(&mdn->dn_struct_rwlock);
1122 if (db == NULL)
1123 return (SET_ERROR(EIO));
1124 err = dbuf_read(db, NULL, DB_RF_CANFAIL);
1125 if (err) {
1126 dbuf_rele(db, FTAG);
1127 return (err);
1128 }
1129
1130 ASSERT3U(db->db.db_size, >=, 1<<DNODE_SHIFT);
1131 epb = db->db.db_size >> DNODE_SHIFT;
1132
1133 idx = object & (epb-1);
1134
1135 ASSERT(DB_DNODE(db)->dn_type == DMU_OT_DNODE);
1136 children_dnodes = dmu_buf_get_user(&db->db);
1137 if (children_dnodes == NULL) {
1138 int i;
1139 dnode_children_t *winner;
1140 children_dnodes = kmem_zalloc(sizeof (dnode_children_t) +
1141 epb * sizeof (dnode_handle_t), KM_SLEEP);
1142 children_dnodes->dnc_count = epb;
1143 dnh = &children_dnodes->dnc_children[0];
1144 for (i = 0; i < epb; i++) {
1145 zrl_init(&dnh[i].dnh_zrlock);
1146 }
1147 dmu_buf_init_user(&children_dnodes->dnc_dbu, NULL,
1148 dnode_buf_evict_async, NULL);
1149 winner = dmu_buf_set_user(&db->db, &children_dnodes->dnc_dbu);
1150 if (winner != NULL) {
1151
1152 for (i = 0; i < epb; i++) {
1153 zrl_destroy(&dnh[i].dnh_zrlock);
1154 }
1155
1156 kmem_free(children_dnodes, sizeof (dnode_children_t) +
1157 epb * sizeof (dnode_handle_t));
1158 children_dnodes = winner;
1159 }
1160 }
1161 ASSERT(children_dnodes->dnc_count == epb);
1162
1163 dnh = &children_dnodes->dnc_children[idx];
1164 zrl_add(&dnh->dnh_zrlock);
1165 dn = dnh->dnh_dnode;
1166 if (dn == NULL) {
1167 dnode_phys_t *phys = (dnode_phys_t *)db->db.db_data+idx;
1168
1169 dn = dnode_create(os, phys, db, object, dnh);
1170 }
1171
1172 mutex_enter(&dn->dn_mtx);
1173 type = dn->dn_type;
1174 if (dn->dn_free_txg ||
1175 ((flag & DNODE_MUST_BE_ALLOCATED) && type == DMU_OT_NONE) ||
1176 ((flag & DNODE_MUST_BE_FREE) &&
1177 (type != DMU_OT_NONE || !refcount_is_zero(&dn->dn_holds)))) {
1178 mutex_exit(&dn->dn_mtx);
1179 zrl_remove(&dnh->dnh_zrlock);
1180 dbuf_rele(db, FTAG);
1181 return ((flag & DNODE_MUST_BE_ALLOCATED) ? ENOENT : EEXIST);
1182 }
1183 if (refcount_add(&dn->dn_holds, tag) == 1)
1184 dbuf_add_ref(db, dnh);
1185 mutex_exit(&dn->dn_mtx);
1186
1187 /* Now we can rely on the hold to prevent the dnode from moving. */
1188 zrl_remove(&dnh->dnh_zrlock);
1189
1190 DNODE_VERIFY(dn);
1191 ASSERT3P(dn->dn_dbuf, ==, db);
1192 ASSERT3U(dn->dn_object, ==, object);
1193 dbuf_rele(db, FTAG);
1194
1195 *dnp = dn;
1196 return (0);
1197 }
1198
1199 /*
1200 * Return held dnode if the object is allocated, NULL if not.
1201 */
1202 int
1203 dnode_hold(objset_t *os, uint64_t object, void *tag, dnode_t **dnp)
1204 {
1205 return (dnode_hold_impl(os, object, DNODE_MUST_BE_ALLOCATED, tag, dnp));
1206 }
1207
1208 /*
1209 * Can only add a reference if there is already at least one
1210 * reference on the dnode. Returns FALSE if unable to add a
1211 * new reference.
1212 */
1213 boolean_t
1214 dnode_add_ref(dnode_t *dn, void *tag)
1215 {
1216 mutex_enter(&dn->dn_mtx);
1217 if (refcount_is_zero(&dn->dn_holds)) {
1218 mutex_exit(&dn->dn_mtx);
1219 return (FALSE);
1220 }
1221 VERIFY(1 < refcount_add(&dn->dn_holds, tag));
1222 mutex_exit(&dn->dn_mtx);
1223 return (TRUE);
1224 }
1225
1226 void
1227 dnode_rele(dnode_t *dn, void *tag)
1228 {
1229 mutex_enter(&dn->dn_mtx);
1230 dnode_rele_and_unlock(dn, tag);
1231 }
1232
1233 void
1234 dnode_rele_and_unlock(dnode_t *dn, void *tag)
1235 {
1236 uint64_t refs;
1237 /* Get while the hold prevents the dnode from moving. */
1238 dmu_buf_impl_t *db = dn->dn_dbuf;
1239 dnode_handle_t *dnh = dn->dn_handle;
1240
1241 refs = refcount_remove(&dn->dn_holds, tag);
1242 mutex_exit(&dn->dn_mtx);
1243
1244 /*
1245 * It's unsafe to release the last hold on a dnode by dnode_rele() or
1246 * indirectly by dbuf_rele() while relying on the dnode handle to
1247 * prevent the dnode from moving, since releasing the last hold could
1248 * result in the dnode's parent dbuf evicting its dnode handles. For
1249 * that reason anyone calling dnode_rele() or dbuf_rele() without some
1250 * other direct or indirect hold on the dnode must first drop the dnode
1251 * handle.
1252 */
1253 ASSERT(refs > 0 || dnh->dnh_zrlock.zr_owner != curthread);
1254
1255 /* NOTE: the DNODE_DNODE does not have a dn_dbuf */
1256 if (refs == 0 && db != NULL) {
1257 /*
1258 * Another thread could add a hold to the dnode handle in
1259 * dnode_hold_impl() while holding the parent dbuf. Since the
1260 * hold on the parent dbuf prevents the handle from being
1261 * destroyed, the hold on the handle is OK. We can't yet assert
1262 * that the handle has zero references, but that will be
1263 * asserted anyway when the handle gets destroyed.
1264 */
1265 dbuf_rele(db, dnh);
1266 }
1267 }
1268
1269 void
1270 dnode_setdirty(dnode_t *dn, dmu_tx_t *tx)
1271 {
1272 objset_t *os = dn->dn_objset;
1273 uint64_t txg = tx->tx_txg;
1274
1275 if (DMU_OBJECT_IS_SPECIAL(dn->dn_object)) {
1276 dsl_dataset_dirty(os->os_dsl_dataset, tx);
1277 return;
1278 }
1279
1280 DNODE_VERIFY(dn);
1281
1282 #ifdef ZFS_DEBUG
1283 mutex_enter(&dn->dn_mtx);
1284 ASSERT(dn->dn_phys->dn_type || dn->dn_allocated_txg);
1285 ASSERT(dn->dn_free_txg == 0 || dn->dn_free_txg >= txg);
1286 mutex_exit(&dn->dn_mtx);
1287 #endif
1288
1289 /*
1290 * Determine old uid/gid when necessary
1291 */
1292 dmu_objset_userquota_get_ids(dn, B_TRUE, tx);
1293
1294 multilist_t *dirtylist = os->os_dirty_dnodes[txg & TXG_MASK];
1295 multilist_sublist_t *mls = multilist_sublist_lock_obj(dirtylist, dn);
1296
1297 /*
1298 * If we are already marked dirty, we're done.
1299 */
1300 if (list_link_active(&dn->dn_dirty_link[txg & TXG_MASK])) {
1301 multilist_sublist_unlock(mls);
1302 return;
1303 }
1304
1305 ASSERT(!refcount_is_zero(&dn->dn_holds) ||
1306 !avl_is_empty(&dn->dn_dbufs));
1307 ASSERT(dn->dn_datablksz != 0);
1308 ASSERT0(dn->dn_next_bonuslen[txg&TXG_MASK]);
1309 ASSERT0(dn->dn_next_blksz[txg&TXG_MASK]);
1310 ASSERT0(dn->dn_next_bonustype[txg&TXG_MASK]);
1311
1312 dprintf_ds(os->os_dsl_dataset, "obj=%llu txg=%llu\n",
1313 dn->dn_object, txg);
1314
1315 multilist_sublist_insert_head(mls, dn);
1316
1317 multilist_sublist_unlock(mls);
1318
1319 /*
1320 * The dnode maintains a hold on its containing dbuf as
1321 * long as there are holds on it. Each instantiated child
1322 * dbuf maintains a hold on the dnode. When the last child
1323 * drops its hold, the dnode will drop its hold on the
1324 * containing dbuf. We add a "dirty hold" here so that the
1325 * dnode will hang around after we finish processing its
1326 * children.
1327 */
1328 VERIFY(dnode_add_ref(dn, (void *)(uintptr_t)tx->tx_txg));
1329
1330 (void) dbuf_dirty(dn->dn_dbuf, tx);
1331
1332 dsl_dataset_dirty(os->os_dsl_dataset, tx);
1333 }
1334
1335 void
1336 dnode_free(dnode_t *dn, dmu_tx_t *tx)
1337 {
1338 mutex_enter(&dn->dn_mtx);
1339 if (dn->dn_type == DMU_OT_NONE || dn->dn_free_txg) {
1340 mutex_exit(&dn->dn_mtx);
1341 return;
1342 }
1343 dn->dn_free_txg = tx->tx_txg;
1344 mutex_exit(&dn->dn_mtx);
1345
1346 dnode_setdirty(dn, tx);
1347 }
1348
1349 /*
1350 * Try to change the block size for the indicated dnode. This can only
1351 * succeed if there are no blocks allocated or dirty beyond first block
1352 */
1353 int
1354 dnode_set_blksz(dnode_t *dn, uint64_t size, int ibs, dmu_tx_t *tx)
1355 {
1356 dmu_buf_impl_t *db;
1357 int err;
1358
1359 ASSERT3U(size, <=, spa_maxblocksize(dmu_objset_spa(dn->dn_objset)));
1360 if (size == 0)
1361 size = SPA_MINBLOCKSIZE;
1362 else
1363 size = P2ROUNDUP(size, SPA_MINBLOCKSIZE);
1364
1365 if (ibs == dn->dn_indblkshift)
1366 ibs = 0;
1367
1368 if (size >> SPA_MINBLOCKSHIFT == dn->dn_datablkszsec && ibs == 0)
1369 return (0);
1370
1371 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
1372
1373 /* Check for any allocated blocks beyond the first */
1374 if (dn->dn_maxblkid != 0)
1375 goto fail;
1376
1377 mutex_enter(&dn->dn_dbufs_mtx);
1378 for (db = avl_first(&dn->dn_dbufs); db != NULL;
1379 db = AVL_NEXT(&dn->dn_dbufs, db)) {
1380 if (db->db_blkid != 0 && db->db_blkid != DMU_BONUS_BLKID &&
1381 db->db_blkid != DMU_SPILL_BLKID) {
1382 mutex_exit(&dn->dn_dbufs_mtx);
1383 goto fail;
1384 }
1385 }
1386 mutex_exit(&dn->dn_dbufs_mtx);
1387
1388 if (ibs && dn->dn_nlevels != 1)
1389 goto fail;
1390
1391 /* resize the old block */
1392 err = dbuf_hold_impl(dn, 0, 0, TRUE, FALSE, FTAG, &db);
1393 if (err == 0)
1394 dbuf_new_size(db, size, tx);
1395 else if (err != ENOENT)
1396 goto fail;
1397
1398 dnode_setdblksz(dn, size);
1399 dnode_setdirty(dn, tx);
1400 dn->dn_next_blksz[tx->tx_txg&TXG_MASK] = size;
1401 if (ibs) {
1402 dn->dn_indblkshift = ibs;
1403 dn->dn_next_indblkshift[tx->tx_txg&TXG_MASK] = ibs;
1404 }
1405 /* rele after we have fixed the blocksize in the dnode */
1406 if (db)
1407 dbuf_rele(db, FTAG);
1408
1409 rw_exit(&dn->dn_struct_rwlock);
1410 return (0);
1411
1412 fail:
1413 rw_exit(&dn->dn_struct_rwlock);
1414 return (SET_ERROR(ENOTSUP));
1415 }
1416
1417 /* read-holding callers must not rely on the lock being continuously held */
1418 void
1419 dnode_new_blkid(dnode_t *dn, uint64_t blkid, dmu_tx_t *tx, boolean_t have_read)
1420 {
1421 uint64_t txgoff = tx->tx_txg & TXG_MASK;
1422 int epbs, new_nlevels;
1423 uint64_t sz;
1424
1425 ASSERT(blkid != DMU_BONUS_BLKID);
1426
1427 ASSERT(have_read ?
1428 RW_READ_HELD(&dn->dn_struct_rwlock) :
1429 RW_WRITE_HELD(&dn->dn_struct_rwlock));
1430
1431 /*
1432 * if we have a read-lock, check to see if we need to do any work
1433 * before upgrading to a write-lock.
1434 */
1435 if (have_read) {
1436 if (blkid <= dn->dn_maxblkid)
1437 return;
1438
1439 if (!rw_tryupgrade(&dn->dn_struct_rwlock)) {
1440 rw_exit(&dn->dn_struct_rwlock);
1441 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
1442 }
1443 }
1444
1445 if (blkid <= dn->dn_maxblkid)
1446 goto out;
1447
1448 dn->dn_maxblkid = blkid;
1449
1450 /*
1451 * Compute the number of levels necessary to support the new maxblkid.
1452 */
1453 new_nlevels = 1;
1454 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT;
1455 for (sz = dn->dn_nblkptr;
1456 sz <= blkid && sz >= dn->dn_nblkptr; sz <<= epbs)
1457 new_nlevels++;
1458
1459 if (new_nlevels > dn->dn_nlevels) {
1460 int old_nlevels = dn->dn_nlevels;
1461 dmu_buf_impl_t *db;
1462 list_t *list;
1463 dbuf_dirty_record_t *new, *dr, *dr_next;
1464
1465 dn->dn_nlevels = new_nlevels;
1466
1467 ASSERT3U(new_nlevels, >, dn->dn_next_nlevels[txgoff]);
1468 dn->dn_next_nlevels[txgoff] = new_nlevels;
1469
1470 /* dirty the left indirects */
1471 db = dbuf_hold_level(dn, old_nlevels, 0, FTAG);
1472 ASSERT(db != NULL);
1473 new = dbuf_dirty(db, tx);
1474 dbuf_rele(db, FTAG);
1475
1476 /* transfer the dirty records to the new indirect */
1477 mutex_enter(&dn->dn_mtx);
1478 mutex_enter(&new->dt.di.dr_mtx);
1479 list = &dn->dn_dirty_records[txgoff];
1480 for (dr = list_head(list); dr; dr = dr_next) {
1481 dr_next = list_next(&dn->dn_dirty_records[txgoff], dr);
1482 if (dr->dr_dbuf->db_level != new_nlevels-1 &&
1483 dr->dr_dbuf->db_blkid != DMU_BONUS_BLKID &&
1484 dr->dr_dbuf->db_blkid != DMU_SPILL_BLKID) {
1485 ASSERT(dr->dr_dbuf->db_level == old_nlevels-1);
1486 list_remove(&dn->dn_dirty_records[txgoff], dr);
1487 list_insert_tail(&new->dt.di.dr_children, dr);
1488 dr->dr_parent = new;
1489 }
1490 }
1491 mutex_exit(&new->dt.di.dr_mtx);
1492 mutex_exit(&dn->dn_mtx);
1493 }
1494
1495 out:
1496 if (have_read)
1497 rw_downgrade(&dn->dn_struct_rwlock);
1498 }
1499
1500 static void
1501 dnode_dirty_l1(dnode_t *dn, uint64_t l1blkid, dmu_tx_t *tx)
1502 {
1503 dmu_buf_impl_t *db = dbuf_hold_level(dn, 1, l1blkid, FTAG);
1504 if (db != NULL) {
1505 dmu_buf_will_dirty(&db->db, tx);
1506 dbuf_rele(db, FTAG);
1507 }
1508 }
1509
1510 void
1511 dnode_free_range(dnode_t *dn, uint64_t off, uint64_t len, dmu_tx_t *tx)
1512 {
1513 dmu_buf_impl_t *db;
1514 uint64_t blkoff, blkid, nblks;
1515 int blksz, blkshift, head, tail;
1516 int trunc = FALSE;
1517 int epbs;
1518
1519 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
1520 blksz = dn->dn_datablksz;
1521 blkshift = dn->dn_datablkshift;
1522 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT;
1523
1524 if (len == DMU_OBJECT_END) {
1525 len = UINT64_MAX - off;
1526 trunc = TRUE;
1527 }
1528
1529 /*
1530 * First, block align the region to free:
1531 */
1532 if (ISP2(blksz)) {
1533 head = P2NPHASE(off, blksz);
1534 blkoff = P2PHASE(off, blksz);
1535 if ((off >> blkshift) > dn->dn_maxblkid)
1536 goto out;
1537 } else {
1538 ASSERT(dn->dn_maxblkid == 0);
1539 if (off == 0 && len >= blksz) {
1540 /*
1541 * Freeing the whole block; fast-track this request.
1542 * Note that we won't dirty any indirect blocks,
1543 * which is fine because we will be freeing the entire
1544 * file and thus all indirect blocks will be freed
1545 * by free_children().
1546 */
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, 0, off),
1566 TRUE, FALSE, 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 dmu_buf_will_dirty(&db->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, 0, off+len),
1604 TRUE, FALSE, 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 dmu_buf_will_dirty(&db->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 * Dirty all the indirect blocks in this range. Note that only
1631 * the first and last indirect blocks can actually be written
1632 * (if they were partially freed) -- they must be dirtied, even if
1633 * they do not exist on disk yet. The interior blocks will
1634 * be freed by free_children(), so they will not actually be written.
1635 * Even though these interior blocks will not be written, we
1636 * dirty them for two reasons:
1637 *
1638 * - It ensures that the indirect blocks remain in memory until
1639 * syncing context. (They have already been prefetched by
1640 * dmu_tx_hold_free(), so we don't have to worry about reading
1641 * them serially here.)
1642 *
1643 * - The dirty space accounting will put pressure on the txg sync
1644 * mechanism to begin syncing, and to delay transactions if there
1645 * is a large amount of freeing. Even though these indirect
1646 * blocks will not be written, we could need to write the same
1647 * amount of space if we copy the freed BPs into deadlists.
1648 */
1649 if (dn->dn_nlevels > 1) {
1650 uint64_t first, last;
1651
1652 first = blkid >> epbs;
1653 dnode_dirty_l1(dn, first, tx);
1654 if (trunc)
1655 last = dn->dn_maxblkid >> epbs;
1656 else
1657 last = (blkid + nblks - 1) >> epbs;
1658 if (last != first)
1659 dnode_dirty_l1(dn, last, tx);
1660
1661 int shift = dn->dn_datablkshift + dn->dn_indblkshift -
1662 SPA_BLKPTRSHIFT;
1663 for (uint64_t i = first + 1; i < last; i++) {
1664 /*
1665 * Set i to the blockid of the next non-hole
1666 * level-1 indirect block at or after i. Note
1667 * that dnode_next_offset() operates in terms of
1668 * level-0-equivalent bytes.
1669 */
1670 uint64_t ibyte = i << shift;
1671 int err = dnode_next_offset(dn, DNODE_FIND_HAVELOCK,
1672 &ibyte, 2, 1, 0);
1673 i = ibyte >> shift;
1674 if (i >= last)
1675 break;
1676
1677 /*
1678 * Normally we should not see an error, either
1679 * from dnode_next_offset() or dbuf_hold_level()
1680 * (except for ESRCH from dnode_next_offset).
1681 * If there is an i/o error, then when we read
1682 * this block in syncing context, it will use
1683 * ZIO_FLAG_MUSTSUCCEED, and thus hang/panic according
1684 * to the "failmode" property. dnode_next_offset()
1685 * doesn't have a flag to indicate MUSTSUCCEED.
1686 */
1687 if (err != 0)
1688 break;
1689
1690 dnode_dirty_l1(dn, i, tx);
1691 }
1692 }
1693
1694 done:
1695 /*
1696 * Add this range to the dnode range list.
1697 * We will finish up this free operation in the syncing phase.
1698 */
1699 mutex_enter(&dn->dn_mtx);
1700 int txgoff = tx->tx_txg & TXG_MASK;
1701 if (dn->dn_free_ranges[txgoff] == NULL) {
1702 dn->dn_free_ranges[txgoff] = range_tree_create(NULL, NULL);
1703 }
1704 range_tree_clear(dn->dn_free_ranges[txgoff], blkid, nblks);
1705 range_tree_add(dn->dn_free_ranges[txgoff], blkid, nblks);
1706 dprintf_dnode(dn, "blkid=%llu nblks=%llu txg=%llu\n",
1707 blkid, nblks, tx->tx_txg);
1708 mutex_exit(&dn->dn_mtx);
1709
1710 dbuf_free_range(dn, blkid, blkid + nblks - 1, tx);
1711 dnode_setdirty(dn, tx);
1712 out:
1713
1714 rw_exit(&dn->dn_struct_rwlock);
1715 }
1716
1717 static boolean_t
1718 dnode_spill_freed(dnode_t *dn)
1719 {
1720 int i;
1721
1722 mutex_enter(&dn->dn_mtx);
1723 for (i = 0; i < TXG_SIZE; i++) {
1724 if (dn->dn_rm_spillblk[i] == DN_KILL_SPILLBLK)
1725 break;
1726 }
1727 mutex_exit(&dn->dn_mtx);
1728 return (i < TXG_SIZE);
1729 }
1730
1731 /* return TRUE if this blkid was freed in a recent txg, or FALSE if it wasn't */
1732 uint64_t
1733 dnode_block_freed(dnode_t *dn, uint64_t blkid)
1734 {
1735 void *dp = spa_get_dsl(dn->dn_objset->os_spa);
1736 int i;
1737
1738 if (blkid == DMU_BONUS_BLKID)
1739 return (FALSE);
1740
1741 /*
1742 * If we're in the process of opening the pool, dp will not be
1743 * set yet, but there shouldn't be anything dirty.
1744 */
1745 if (dp == NULL)
1746 return (FALSE);
1747
1748 if (dn->dn_free_txg)
1749 return (TRUE);
1750
1751 if (blkid == DMU_SPILL_BLKID)
1752 return (dnode_spill_freed(dn));
1753
1754 mutex_enter(&dn->dn_mtx);
1755 for (i = 0; i < TXG_SIZE; i++) {
1756 if (dn->dn_free_ranges[i] != NULL &&
1757 range_tree_contains(dn->dn_free_ranges[i], blkid, 1))
1758 break;
1759 }
1760 mutex_exit(&dn->dn_mtx);
1761 return (i < TXG_SIZE);
1762 }
1763
1764 /* call from syncing context when we actually write/free space for this dnode */
1765 void
1766 dnode_diduse_space(dnode_t *dn, int64_t delta)
1767 {
1768 uint64_t space;
1769 dprintf_dnode(dn, "dn=%p dnp=%p used=%llu delta=%lld\n",
1770 dn, dn->dn_phys,
1771 (u_longlong_t)dn->dn_phys->dn_used,
1772 (longlong_t)delta);
1773
1774 mutex_enter(&dn->dn_mtx);
1775 space = DN_USED_BYTES(dn->dn_phys);
1776 if (delta > 0) {
1777 ASSERT3U(space + delta, >=, space); /* no overflow */
1778 } else {
1779 ASSERT3U(space, >=, -delta); /* no underflow */
1780 }
1781 space += delta;
1782 if (spa_version(dn->dn_objset->os_spa) < SPA_VERSION_DNODE_BYTES) {
1783 ASSERT((dn->dn_phys->dn_flags & DNODE_FLAG_USED_BYTES) == 0);
1784 ASSERT0(P2PHASE(space, 1<<DEV_BSHIFT));
1785 dn->dn_phys->dn_used = space >> DEV_BSHIFT;
1786 } else {
1787 dn->dn_phys->dn_used = space;
1788 dn->dn_phys->dn_flags |= DNODE_FLAG_USED_BYTES;
1789 }
1790 mutex_exit(&dn->dn_mtx);
1791 }
1792
1793 /*
1794 * Scans a block at the indicated "level" looking for a hole or data,
1795 * depending on 'flags'.
1796 *
1797 * If level > 0, then we are scanning an indirect block looking at its
1798 * pointers. If level == 0, then we are looking at a block of dnodes.
1799 *
1800 * If we don't find what we are looking for in the block, we return ESRCH.
1801 * Otherwise, return with *offset pointing to the beginning (if searching
1802 * forwards) or end (if searching backwards) of the range covered by the
1803 * block pointer we matched on (or dnode).
1804 *
1805 * The basic search algorithm used below by dnode_next_offset() is to
1806 * use this function to search up the block tree (widen the search) until
1807 * we find something (i.e., we don't return ESRCH) and then search back
1808 * down the tree (narrow the search) until we reach our original search
1809 * level.
1810 */
1811 static int
1812 dnode_next_offset_level(dnode_t *dn, int flags, uint64_t *offset,
1813 int lvl, uint64_t blkfill, uint64_t txg)
1814 {
1815 dmu_buf_impl_t *db = NULL;
1816 void *data = NULL;
1817 uint64_t epbs = dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT;
1818 uint64_t epb = 1ULL << epbs;
1819 uint64_t minfill, maxfill;
1820 boolean_t hole;
1821 int i, inc, error, span;
1822
1823 dprintf("probing object %llu offset %llx level %d of %u\n",
1824 dn->dn_object, *offset, lvl, dn->dn_phys->dn_nlevels);
1825
1826 hole = ((flags & DNODE_FIND_HOLE) != 0);
1827 inc = (flags & DNODE_FIND_BACKWARDS) ? -1 : 1;
1828 ASSERT(txg == 0 || !hole);
1829
1830 if (lvl == dn->dn_phys->dn_nlevels) {
1831 error = 0;
1832 epb = dn->dn_phys->dn_nblkptr;
1833 data = dn->dn_phys->dn_blkptr;
1834 } else {
1835 uint64_t blkid = dbuf_whichblock(dn, lvl, *offset);
1836 error = dbuf_hold_impl(dn, lvl, blkid, TRUE, FALSE, FTAG, &db);
1837 if (error) {
1838 if (error != ENOENT)
1839 return (error);
1840 if (hole)
1841 return (0);
1842 /*
1843 * This can only happen when we are searching up
1844 * the block tree for data. We don't really need to
1845 * adjust the offset, as we will just end up looking
1846 * at the pointer to this block in its parent, and its
1847 * going to be unallocated, so we will skip over it.
1848 */
1849 return (SET_ERROR(ESRCH));
1850 }
1851 error = dbuf_read(db, NULL, DB_RF_CANFAIL | DB_RF_HAVESTRUCT);
1852 if (error) {
1853 dbuf_rele(db, FTAG);
1854 return (error);
1855 }
1856 data = db->db.db_data;
1857 }
1858
1859
1860 if (db != NULL && txg != 0 && (db->db_blkptr == NULL ||
1861 db->db_blkptr->blk_birth <= txg ||
1862 BP_IS_HOLE(db->db_blkptr))) {
1863 /*
1864 * This can only happen when we are searching up the tree
1865 * and these conditions mean that we need to keep climbing.
1866 */
1867 error = SET_ERROR(ESRCH);
1868 } else if (lvl == 0) {
1869 dnode_phys_t *dnp = data;
1870 span = DNODE_SHIFT;
1871 ASSERT(dn->dn_type == DMU_OT_DNODE);
1872
1873 for (i = (*offset >> span) & (blkfill - 1);
1874 i >= 0 && i < blkfill; i += inc) {
1875 if ((dnp[i].dn_type == DMU_OT_NONE) == hole)
1876 break;
1877 *offset += (1ULL << span) * inc;
1878 }
1879 if (i < 0 || i == blkfill)
1880 error = SET_ERROR(ESRCH);
1881 } else {
1882 blkptr_t *bp = data;
1883 uint64_t start = *offset;
1884 span = (lvl - 1) * epbs + dn->dn_datablkshift;
1885 minfill = 0;
1886 maxfill = blkfill << ((lvl - 1) * epbs);
1887
1888 if (hole)
1889 maxfill--;
1890 else
1891 minfill++;
1892
1893 *offset = *offset >> span;
1894 for (i = BF64_GET(*offset, 0, epbs);
1895 i >= 0 && i < epb; i += inc) {
1896 if (BP_GET_FILL(&bp[i]) >= minfill &&
1897 BP_GET_FILL(&bp[i]) <= maxfill &&
1898 (hole || bp[i].blk_birth > txg))
1899 break;
1900 if (inc > 0 || *offset > 0)
1901 *offset += inc;
1902 }
1903 *offset = *offset << span;
1904 if (inc < 0) {
1905 /* traversing backwards; position offset at the end */
1906 ASSERT3U(*offset, <=, start);
1907 *offset = MIN(*offset + (1ULL << span) - 1, start);
1908 } else if (*offset < start) {
1909 *offset = start;
1910 }
1911 if (i < 0 || i >= epb)
1912 error = SET_ERROR(ESRCH);
1913 }
1914
1915 if (db)
1916 dbuf_rele(db, FTAG);
1917
1918 return (error);
1919 }
1920
1921 /*
1922 * Find the next hole, data, or sparse region at or after *offset.
1923 * The value 'blkfill' tells us how many items we expect to find
1924 * in an L0 data block; this value is 1 for normal objects,
1925 * DNODES_PER_BLOCK for the meta dnode, and some fraction of
1926 * DNODES_PER_BLOCK when searching for sparse regions thereof.
1927 *
1928 * Examples:
1929 *
1930 * dnode_next_offset(dn, flags, offset, 1, 1, 0);
1931 * Finds the next/previous hole/data in a file.
1932 * Used in dmu_offset_next().
1933 *
1934 * dnode_next_offset(mdn, flags, offset, 0, DNODES_PER_BLOCK, txg);
1935 * Finds the next free/allocated dnode an objset's meta-dnode.
1936 * Only finds objects that have new contents since txg (ie.
1937 * bonus buffer changes and content removal are ignored).
1938 * Used in dmu_object_next().
1939 *
1940 * dnode_next_offset(mdn, DNODE_FIND_HOLE, offset, 2, DNODES_PER_BLOCK >> 2, 0);
1941 * Finds the next L2 meta-dnode bp that's at most 1/4 full.
1942 * Used in dmu_object_alloc().
1943 */
1944 int
1945 dnode_next_offset(dnode_t *dn, int flags, uint64_t *offset,
1946 int minlvl, uint64_t blkfill, uint64_t txg)
1947 {
1948 uint64_t initial_offset = *offset;
1949 int lvl, maxlvl;
1950 int error = 0;
1951
1952 if (!(flags & DNODE_FIND_HAVELOCK))
1953 rw_enter(&dn->dn_struct_rwlock, RW_READER);
1954
1955 if (dn->dn_phys->dn_nlevels == 0) {
1956 error = SET_ERROR(ESRCH);
1957 goto out;
1958 }
1959
1960 if (dn->dn_datablkshift == 0) {
1961 if (*offset < dn->dn_datablksz) {
1962 if (flags & DNODE_FIND_HOLE)
1963 *offset = dn->dn_datablksz;
1964 } else {
1965 error = SET_ERROR(ESRCH);
1966 }
1967 goto out;
1968 }
1969
1970 maxlvl = dn->dn_phys->dn_nlevels;
1971
1972 for (lvl = minlvl; lvl <= maxlvl; lvl++) {
1973 error = dnode_next_offset_level(dn,
1974 flags, offset, lvl, blkfill, txg);
1975 if (error != ESRCH)
1976 break;
1977 }
1978
1979 while (error == 0 && --lvl >= minlvl) {
1980 error = dnode_next_offset_level(dn,
1981 flags, offset, lvl, blkfill, txg);
1982 }
1983
1984 /*
1985 * There's always a "virtual hole" at the end of the object, even
1986 * if all BP's which physically exist are non-holes.
1987 */
1988 if ((flags & DNODE_FIND_HOLE) && error == ESRCH && txg == 0 &&
1989 minlvl == 1 && blkfill == 1 && !(flags & DNODE_FIND_BACKWARDS)) {
1990 error = 0;
1991 }
1992
1993 if (error == 0 && (flags & DNODE_FIND_BACKWARDS ?
1994 initial_offset < *offset : initial_offset > *offset))
1995 error = SET_ERROR(ESRCH);
1996 out:
1997 if (!(flags & DNODE_FIND_HAVELOCK))
1998 rw_exit(&dn->dn_struct_rwlock);
1999
2000 return (error);
2001 }
Unleashed OS