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BRT should return EOPNOTSUPP
[zfs.git] / module / zfs / dnode.c
blob7cf03264dce241835432dfb068ffb14023ef575e
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 https://opensource.org/licenses/CDDL-1.0.
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, 2020 by Delphix. All rights reserved.
24 * Copyright (c) 2014 Spectra Logic Corporation, All rights reserved.
25 */
26
27 #include <sys/zfs_context.h>
28 #include <sys/dbuf.h>
29 #include <sys/dnode.h>
30 #include <sys/dmu.h>
31 #include <sys/dmu_impl.h>
32 #include <sys/dmu_tx.h>
33 #include <sys/dmu_objset.h>
34 #include <sys/dsl_dir.h>
35 #include <sys/dsl_dataset.h>
36 #include <sys/spa.h>
37 #include <sys/zio.h>
38 #include <sys/dmu_zfetch.h>
39 #include <sys/range_tree.h>
40 #include <sys/trace_zfs.h>
41 #include <sys/zfs_project.h>
42
43 dnode_stats_t dnode_stats = {
44 { "dnode_hold_dbuf_hold", KSTAT_DATA_UINT64 },
45 { "dnode_hold_dbuf_read", KSTAT_DATA_UINT64 },
46 { "dnode_hold_alloc_hits", KSTAT_DATA_UINT64 },
47 { "dnode_hold_alloc_misses", KSTAT_DATA_UINT64 },
48 { "dnode_hold_alloc_interior", KSTAT_DATA_UINT64 },
49 { "dnode_hold_alloc_lock_retry", KSTAT_DATA_UINT64 },
50 { "dnode_hold_alloc_lock_misses", KSTAT_DATA_UINT64 },
51 { "dnode_hold_alloc_type_none", KSTAT_DATA_UINT64 },
52 { "dnode_hold_free_hits", KSTAT_DATA_UINT64 },
53 { "dnode_hold_free_misses", KSTAT_DATA_UINT64 },
54 { "dnode_hold_free_lock_misses", KSTAT_DATA_UINT64 },
55 { "dnode_hold_free_lock_retry", KSTAT_DATA_UINT64 },
56 { "dnode_hold_free_overflow", KSTAT_DATA_UINT64 },
57 { "dnode_hold_free_refcount", KSTAT_DATA_UINT64 },
58 { "dnode_free_interior_lock_retry", KSTAT_DATA_UINT64 },
59 { "dnode_allocate", KSTAT_DATA_UINT64 },
60 { "dnode_reallocate", KSTAT_DATA_UINT64 },
61 { "dnode_buf_evict", KSTAT_DATA_UINT64 },
62 { "dnode_alloc_next_chunk", KSTAT_DATA_UINT64 },
63 { "dnode_alloc_race", KSTAT_DATA_UINT64 },
64 { "dnode_alloc_next_block", KSTAT_DATA_UINT64 },
65 { "dnode_move_invalid", KSTAT_DATA_UINT64 },
66 { "dnode_move_recheck1", KSTAT_DATA_UINT64 },
67 { "dnode_move_recheck2", KSTAT_DATA_UINT64 },
68 { "dnode_move_special", KSTAT_DATA_UINT64 },
69 { "dnode_move_handle", KSTAT_DATA_UINT64 },
70 { "dnode_move_rwlock", KSTAT_DATA_UINT64 },
71 { "dnode_move_active", KSTAT_DATA_UINT64 },
72 };
73
74 dnode_sums_t dnode_sums;
75
76 static kstat_t *dnode_ksp;
77 static kmem_cache_t *dnode_cache;
78
79 static dnode_phys_t dnode_phys_zero __maybe_unused;
80
81 int zfs_default_bs = SPA_MINBLOCKSHIFT;
82 int zfs_default_ibs = DN_MAX_INDBLKSHIFT;
83
84 #ifdef _KERNEL
85 static kmem_cbrc_t dnode_move(void *, void *, size_t, void *);
86 #endif /* _KERNEL */
87
88 static int
89 dbuf_compare(const void *x1, const void *x2)
90 {
91 const dmu_buf_impl_t *d1 = x1;
92 const dmu_buf_impl_t *d2 = x2;
93
94 int cmp = TREE_CMP(d1->db_level, d2->db_level);
95 if (likely(cmp))
96 return (cmp);
97
98 cmp = TREE_CMP(d1->db_blkid, d2->db_blkid);
99 if (likely(cmp))
100 return (cmp);
101
102 if (d1->db_state == DB_SEARCH) {
103 ASSERT3S(d2->db_state, !=, DB_SEARCH);
104 return (-1);
105 } else if (d2->db_state == DB_SEARCH) {
106 ASSERT3S(d1->db_state, !=, DB_SEARCH);
107 return (1);
108 }
109
110 return (TREE_PCMP(d1, d2));
111 }
112
113 static int
114 dnode_cons(void *arg, void *unused, int kmflag)
115 {
116 (void) unused, (void) kmflag;
117 dnode_t *dn = arg;
118
119 rw_init(&dn->dn_struct_rwlock, NULL, RW_NOLOCKDEP, NULL);
120 mutex_init(&dn->dn_mtx, NULL, MUTEX_DEFAULT, NULL);
121 mutex_init(&dn->dn_dbufs_mtx, NULL, MUTEX_DEFAULT, NULL);
122 cv_init(&dn->dn_notxholds, NULL, CV_DEFAULT, NULL);
123 cv_init(&dn->dn_nodnholds, NULL, CV_DEFAULT, NULL);
124
125 /*
126 * Every dbuf has a reference, and dropping a tracked reference is
127 * O(number of references), so don't track dn_holds.
128 */
129 zfs_refcount_create_untracked(&dn->dn_holds);
130 zfs_refcount_create(&dn->dn_tx_holds);
131 list_link_init(&dn->dn_link);
132
133 memset(dn->dn_next_type, 0, sizeof (dn->dn_next_type));
134 memset(dn->dn_next_nblkptr, 0, sizeof (dn->dn_next_nblkptr));
135 memset(dn->dn_next_nlevels, 0, sizeof (dn->dn_next_nlevels));
136 memset(dn->dn_next_indblkshift, 0, sizeof (dn->dn_next_indblkshift));
137 memset(dn->dn_next_bonustype, 0, sizeof (dn->dn_next_bonustype));
138 memset(dn->dn_rm_spillblk, 0, sizeof (dn->dn_rm_spillblk));
139 memset(dn->dn_next_bonuslen, 0, sizeof (dn->dn_next_bonuslen));
140 memset(dn->dn_next_blksz, 0, sizeof (dn->dn_next_blksz));
141 memset(dn->dn_next_maxblkid, 0, sizeof (dn->dn_next_maxblkid));
142
143 for (int i = 0; i < TXG_SIZE; i++) {
144 multilist_link_init(&dn->dn_dirty_link[i]);
145 dn->dn_free_ranges[i] = NULL;
146 list_create(&dn->dn_dirty_records[i],
147 sizeof (dbuf_dirty_record_t),
148 offsetof(dbuf_dirty_record_t, dr_dirty_node));
149 }
150
151 dn->dn_allocated_txg = 0;
152 dn->dn_free_txg = 0;
153 dn->dn_assigned_txg = 0;
154 dn->dn_dirty_txg = 0;
155 dn->dn_dirtyctx = 0;
156 dn->dn_dirtyctx_firstset = NULL;
157 dn->dn_bonus = NULL;
158 dn->dn_have_spill = B_FALSE;
159 dn->dn_zio = NULL;
160 dn->dn_oldused = 0;
161 dn->dn_oldflags = 0;
162 dn->dn_olduid = 0;
163 dn->dn_oldgid = 0;
164 dn->dn_oldprojid = ZFS_DEFAULT_PROJID;
165 dn->dn_newuid = 0;
166 dn->dn_newgid = 0;
167 dn->dn_newprojid = ZFS_DEFAULT_PROJID;
168 dn->dn_id_flags = 0;
169
170 dn->dn_dbufs_count = 0;
171 avl_create(&dn->dn_dbufs, dbuf_compare, sizeof (dmu_buf_impl_t),
172 offsetof(dmu_buf_impl_t, db_link));
173
174 dn->dn_moved = 0;
175 return (0);
176 }
177
178 static void
179 dnode_dest(void *arg, void *unused)
180 {
181 (void) unused;
182 dnode_t *dn = arg;
183
184 rw_destroy(&dn->dn_struct_rwlock);
185 mutex_destroy(&dn->dn_mtx);
186 mutex_destroy(&dn->dn_dbufs_mtx);
187 cv_destroy(&dn->dn_notxholds);
188 cv_destroy(&dn->dn_nodnholds);
189 zfs_refcount_destroy(&dn->dn_holds);
190 zfs_refcount_destroy(&dn->dn_tx_holds);
191 ASSERT(!list_link_active(&dn->dn_link));
192
193 for (int i = 0; i < TXG_SIZE; i++) {
194 ASSERT(!multilist_link_active(&dn->dn_dirty_link[i]));
195 ASSERT3P(dn->dn_free_ranges[i], ==, NULL);
196 list_destroy(&dn->dn_dirty_records[i]);
197 ASSERT0(dn->dn_next_nblkptr[i]);
198 ASSERT0(dn->dn_next_nlevels[i]);
199 ASSERT0(dn->dn_next_indblkshift[i]);
200 ASSERT0(dn->dn_next_bonustype[i]);
201 ASSERT0(dn->dn_rm_spillblk[i]);
202 ASSERT0(dn->dn_next_bonuslen[i]);
203 ASSERT0(dn->dn_next_blksz[i]);
204 ASSERT0(dn->dn_next_maxblkid[i]);
205 }
206
207 ASSERT0(dn->dn_allocated_txg);
208 ASSERT0(dn->dn_free_txg);
209 ASSERT0(dn->dn_assigned_txg);
210 ASSERT0(dn->dn_dirty_txg);
211 ASSERT0(dn->dn_dirtyctx);
212 ASSERT3P(dn->dn_dirtyctx_firstset, ==, NULL);
213 ASSERT3P(dn->dn_bonus, ==, NULL);
214 ASSERT(!dn->dn_have_spill);
215 ASSERT3P(dn->dn_zio, ==, NULL);
216 ASSERT0(dn->dn_oldused);
217 ASSERT0(dn->dn_oldflags);
218 ASSERT0(dn->dn_olduid);
219 ASSERT0(dn->dn_oldgid);
220 ASSERT0(dn->dn_oldprojid);
221 ASSERT0(dn->dn_newuid);
222 ASSERT0(dn->dn_newgid);
223 ASSERT0(dn->dn_newprojid);
224 ASSERT0(dn->dn_id_flags);
225
226 ASSERT0(dn->dn_dbufs_count);
227 avl_destroy(&dn->dn_dbufs);
228 }
229
230 static int
231 dnode_kstats_update(kstat_t *ksp, int rw)
232 {
233 dnode_stats_t *ds = ksp->ks_data;
234
235 if (rw == KSTAT_WRITE)
236 return (EACCES);
237 ds->dnode_hold_dbuf_hold.value.ui64 =
238 wmsum_value(&dnode_sums.dnode_hold_dbuf_hold);
239 ds->dnode_hold_dbuf_read.value.ui64 =
240 wmsum_value(&dnode_sums.dnode_hold_dbuf_read);
241 ds->dnode_hold_alloc_hits.value.ui64 =
242 wmsum_value(&dnode_sums.dnode_hold_alloc_hits);
243 ds->dnode_hold_alloc_misses.value.ui64 =
244 wmsum_value(&dnode_sums.dnode_hold_alloc_misses);
245 ds->dnode_hold_alloc_interior.value.ui64 =
246 wmsum_value(&dnode_sums.dnode_hold_alloc_interior);
247 ds->dnode_hold_alloc_lock_retry.value.ui64 =
248 wmsum_value(&dnode_sums.dnode_hold_alloc_lock_retry);
249 ds->dnode_hold_alloc_lock_misses.value.ui64 =
250 wmsum_value(&dnode_sums.dnode_hold_alloc_lock_misses);
251 ds->dnode_hold_alloc_type_none.value.ui64 =
252 wmsum_value(&dnode_sums.dnode_hold_alloc_type_none);
253 ds->dnode_hold_free_hits.value.ui64 =
254 wmsum_value(&dnode_sums.dnode_hold_free_hits);
255 ds->dnode_hold_free_misses.value.ui64 =
256 wmsum_value(&dnode_sums.dnode_hold_free_misses);
257 ds->dnode_hold_free_lock_misses.value.ui64 =
258 wmsum_value(&dnode_sums.dnode_hold_free_lock_misses);
259 ds->dnode_hold_free_lock_retry.value.ui64 =
260 wmsum_value(&dnode_sums.dnode_hold_free_lock_retry);
261 ds->dnode_hold_free_refcount.value.ui64 =
262 wmsum_value(&dnode_sums.dnode_hold_free_refcount);
263 ds->dnode_hold_free_overflow.value.ui64 =
264 wmsum_value(&dnode_sums.dnode_hold_free_overflow);
265 ds->dnode_free_interior_lock_retry.value.ui64 =
266 wmsum_value(&dnode_sums.dnode_free_interior_lock_retry);
267 ds->dnode_allocate.value.ui64 =
268 wmsum_value(&dnode_sums.dnode_allocate);
269 ds->dnode_reallocate.value.ui64 =
270 wmsum_value(&dnode_sums.dnode_reallocate);
271 ds->dnode_buf_evict.value.ui64 =
272 wmsum_value(&dnode_sums.dnode_buf_evict);
273 ds->dnode_alloc_next_chunk.value.ui64 =
274 wmsum_value(&dnode_sums.dnode_alloc_next_chunk);
275 ds->dnode_alloc_race.value.ui64 =
276 wmsum_value(&dnode_sums.dnode_alloc_race);
277 ds->dnode_alloc_next_block.value.ui64 =
278 wmsum_value(&dnode_sums.dnode_alloc_next_block);
279 ds->dnode_move_invalid.value.ui64 =
280 wmsum_value(&dnode_sums.dnode_move_invalid);
281 ds->dnode_move_recheck1.value.ui64 =
282 wmsum_value(&dnode_sums.dnode_move_recheck1);
283 ds->dnode_move_recheck2.value.ui64 =
284 wmsum_value(&dnode_sums.dnode_move_recheck2);
285 ds->dnode_move_special.value.ui64 =
286 wmsum_value(&dnode_sums.dnode_move_special);
287 ds->dnode_move_handle.value.ui64 =
288 wmsum_value(&dnode_sums.dnode_move_handle);
289 ds->dnode_move_rwlock.value.ui64 =
290 wmsum_value(&dnode_sums.dnode_move_rwlock);
291 ds->dnode_move_active.value.ui64 =
292 wmsum_value(&dnode_sums.dnode_move_active);
293 return (0);
294 }
295
296 void
297 dnode_init(void)
298 {
299 ASSERT(dnode_cache == NULL);
300 dnode_cache = kmem_cache_create("dnode_t", sizeof (dnode_t),
301 0, dnode_cons, dnode_dest, NULL, NULL, NULL, 0);
302 kmem_cache_set_move(dnode_cache, dnode_move);
303
304 wmsum_init(&dnode_sums.dnode_hold_dbuf_hold, 0);
305 wmsum_init(&dnode_sums.dnode_hold_dbuf_read, 0);
306 wmsum_init(&dnode_sums.dnode_hold_alloc_hits, 0);
307 wmsum_init(&dnode_sums.dnode_hold_alloc_misses, 0);
308 wmsum_init(&dnode_sums.dnode_hold_alloc_interior, 0);
309 wmsum_init(&dnode_sums.dnode_hold_alloc_lock_retry, 0);
310 wmsum_init(&dnode_sums.dnode_hold_alloc_lock_misses, 0);
311 wmsum_init(&dnode_sums.dnode_hold_alloc_type_none, 0);
312 wmsum_init(&dnode_sums.dnode_hold_free_hits, 0);
313 wmsum_init(&dnode_sums.dnode_hold_free_misses, 0);
314 wmsum_init(&dnode_sums.dnode_hold_free_lock_misses, 0);
315 wmsum_init(&dnode_sums.dnode_hold_free_lock_retry, 0);
316 wmsum_init(&dnode_sums.dnode_hold_free_refcount, 0);
317 wmsum_init(&dnode_sums.dnode_hold_free_overflow, 0);
318 wmsum_init(&dnode_sums.dnode_free_interior_lock_retry, 0);
319 wmsum_init(&dnode_sums.dnode_allocate, 0);
320 wmsum_init(&dnode_sums.dnode_reallocate, 0);
321 wmsum_init(&dnode_sums.dnode_buf_evict, 0);
322 wmsum_init(&dnode_sums.dnode_alloc_next_chunk, 0);
323 wmsum_init(&dnode_sums.dnode_alloc_race, 0);
324 wmsum_init(&dnode_sums.dnode_alloc_next_block, 0);
325 wmsum_init(&dnode_sums.dnode_move_invalid, 0);
326 wmsum_init(&dnode_sums.dnode_move_recheck1, 0);
327 wmsum_init(&dnode_sums.dnode_move_recheck2, 0);
328 wmsum_init(&dnode_sums.dnode_move_special, 0);
329 wmsum_init(&dnode_sums.dnode_move_handle, 0);
330 wmsum_init(&dnode_sums.dnode_move_rwlock, 0);
331 wmsum_init(&dnode_sums.dnode_move_active, 0);
332
333 dnode_ksp = kstat_create("zfs", 0, "dnodestats", "misc",
334 KSTAT_TYPE_NAMED, sizeof (dnode_stats) / sizeof (kstat_named_t),
335 KSTAT_FLAG_VIRTUAL);
336 if (dnode_ksp != NULL) {
337 dnode_ksp->ks_data = &dnode_stats;
338 dnode_ksp->ks_update = dnode_kstats_update;
339 kstat_install(dnode_ksp);
340 }
341 }
342
343 void
344 dnode_fini(void)
345 {
346 if (dnode_ksp != NULL) {
347 kstat_delete(dnode_ksp);
348 dnode_ksp = NULL;
349 }
350
351 wmsum_fini(&dnode_sums.dnode_hold_dbuf_hold);
352 wmsum_fini(&dnode_sums.dnode_hold_dbuf_read);
353 wmsum_fini(&dnode_sums.dnode_hold_alloc_hits);
354 wmsum_fini(&dnode_sums.dnode_hold_alloc_misses);
355 wmsum_fini(&dnode_sums.dnode_hold_alloc_interior);
356 wmsum_fini(&dnode_sums.dnode_hold_alloc_lock_retry);
357 wmsum_fini(&dnode_sums.dnode_hold_alloc_lock_misses);
358 wmsum_fini(&dnode_sums.dnode_hold_alloc_type_none);
359 wmsum_fini(&dnode_sums.dnode_hold_free_hits);
360 wmsum_fini(&dnode_sums.dnode_hold_free_misses);
361 wmsum_fini(&dnode_sums.dnode_hold_free_lock_misses);
362 wmsum_fini(&dnode_sums.dnode_hold_free_lock_retry);
363 wmsum_fini(&dnode_sums.dnode_hold_free_refcount);
364 wmsum_fini(&dnode_sums.dnode_hold_free_overflow);
365 wmsum_fini(&dnode_sums.dnode_free_interior_lock_retry);
366 wmsum_fini(&dnode_sums.dnode_allocate);
367 wmsum_fini(&dnode_sums.dnode_reallocate);
368 wmsum_fini(&dnode_sums.dnode_buf_evict);
369 wmsum_fini(&dnode_sums.dnode_alloc_next_chunk);
370 wmsum_fini(&dnode_sums.dnode_alloc_race);
371 wmsum_fini(&dnode_sums.dnode_alloc_next_block);
372 wmsum_fini(&dnode_sums.dnode_move_invalid);
373 wmsum_fini(&dnode_sums.dnode_move_recheck1);
374 wmsum_fini(&dnode_sums.dnode_move_recheck2);
375 wmsum_fini(&dnode_sums.dnode_move_special);
376 wmsum_fini(&dnode_sums.dnode_move_handle);
377 wmsum_fini(&dnode_sums.dnode_move_rwlock);
378 wmsum_fini(&dnode_sums.dnode_move_active);
379
380 kmem_cache_destroy(dnode_cache);
381 dnode_cache = NULL;
382 }
383
384
385 #ifdef ZFS_DEBUG
386 void
387 dnode_verify(dnode_t *dn)
388 {
389 int drop_struct_lock = FALSE;
390
391 ASSERT(dn->dn_phys);
392 ASSERT(dn->dn_objset);
393 ASSERT(dn->dn_handle->dnh_dnode == dn);
394
395 ASSERT(DMU_OT_IS_VALID(dn->dn_phys->dn_type));
396
397 if (!(zfs_flags & ZFS_DEBUG_DNODE_VERIFY))
398 return;
399
400 if (!RW_WRITE_HELD(&dn->dn_struct_rwlock)) {
401 rw_enter(&dn->dn_struct_rwlock, RW_READER);
402 drop_struct_lock = TRUE;
403 }
404 if (dn->dn_phys->dn_type != DMU_OT_NONE || dn->dn_allocated_txg != 0) {
405 int i;
406 int max_bonuslen = DN_SLOTS_TO_BONUSLEN(dn->dn_num_slots);
407 ASSERT3U(dn->dn_indblkshift, <=, SPA_MAXBLOCKSHIFT);
408 if (dn->dn_datablkshift) {
409 ASSERT3U(dn->dn_datablkshift, >=, SPA_MINBLOCKSHIFT);
410 ASSERT3U(dn->dn_datablkshift, <=, SPA_MAXBLOCKSHIFT);
411 ASSERT3U(1<<dn->dn_datablkshift, ==, dn->dn_datablksz);
412 }
413 ASSERT3U(dn->dn_nlevels, <=, 30);
414 ASSERT(DMU_OT_IS_VALID(dn->dn_type));
415 ASSERT3U(dn->dn_nblkptr, >=, 1);
416 ASSERT3U(dn->dn_nblkptr, <=, DN_MAX_NBLKPTR);
417 ASSERT3U(dn->dn_bonuslen, <=, max_bonuslen);
418 ASSERT3U(dn->dn_datablksz, ==,
419 dn->dn_datablkszsec << SPA_MINBLOCKSHIFT);
420 ASSERT3U(ISP2(dn->dn_datablksz), ==, dn->dn_datablkshift != 0);
421 ASSERT3U((dn->dn_nblkptr - 1) * sizeof (blkptr_t) +
422 dn->dn_bonuslen, <=, max_bonuslen);
423 for (i = 0; i < TXG_SIZE; i++) {
424 ASSERT3U(dn->dn_next_nlevels[i], <=, dn->dn_nlevels);
425 }
426 }
427 if (dn->dn_phys->dn_type != DMU_OT_NONE)
428 ASSERT3U(dn->dn_phys->dn_nlevels, <=, dn->dn_nlevels);
429 ASSERT(DMU_OBJECT_IS_SPECIAL(dn->dn_object) || dn->dn_dbuf != NULL);
430 if (dn->dn_dbuf != NULL) {
431 ASSERT3P(dn->dn_phys, ==,
432 (dnode_phys_t *)dn->dn_dbuf->db.db_data +
433 (dn->dn_object % (dn->dn_dbuf->db.db_size >> DNODE_SHIFT)));
434 }
435 if (drop_struct_lock)
436 rw_exit(&dn->dn_struct_rwlock);
437 }
438 #endif
439
440 void
441 dnode_byteswap(dnode_phys_t *dnp)
442 {
443 uint64_t *buf64 = (void*)&dnp->dn_blkptr;
444 int i;
445
446 if (dnp->dn_type == DMU_OT_NONE) {
447 memset(dnp, 0, sizeof (dnode_phys_t));
448 return;
449 }
450
451 dnp->dn_datablkszsec = BSWAP_16(dnp->dn_datablkszsec);
452 dnp->dn_bonuslen = BSWAP_16(dnp->dn_bonuslen);
453 dnp->dn_extra_slots = BSWAP_8(dnp->dn_extra_slots);
454 dnp->dn_maxblkid = BSWAP_64(dnp->dn_maxblkid);
455 dnp->dn_used = BSWAP_64(dnp->dn_used);
456
457 /*
458 * dn_nblkptr is only one byte, so it's OK to read it in either
459 * byte order. We can't read dn_bouslen.
460 */
461 ASSERT(dnp->dn_indblkshift <= SPA_MAXBLOCKSHIFT);
462 ASSERT(dnp->dn_nblkptr <= DN_MAX_NBLKPTR);
463 for (i = 0; i < dnp->dn_nblkptr * sizeof (blkptr_t)/8; i++)
464 buf64[i] = BSWAP_64(buf64[i]);
465
466 /*
467 * OK to check dn_bonuslen for zero, because it won't matter if
468 * we have the wrong byte order. This is necessary because the
469 * dnode dnode is smaller than a regular dnode.
470 */
471 if (dnp->dn_bonuslen != 0) {
472 dmu_object_byteswap_t byteswap;
473 ASSERT(DMU_OT_IS_VALID(dnp->dn_bonustype));
474 byteswap = DMU_OT_BYTESWAP(dnp->dn_bonustype);
475 dmu_ot_byteswap[byteswap].ob_func(DN_BONUS(dnp),
476 DN_MAX_BONUS_LEN(dnp));
477 }
478
479 /* Swap SPILL block if we have one */
480 if (dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR)
481 byteswap_uint64_array(DN_SPILL_BLKPTR(dnp), sizeof (blkptr_t));
482 }
483
484 void
485 dnode_buf_byteswap(void *vbuf, size_t size)
486 {
487 int i = 0;
488
489 ASSERT3U(sizeof (dnode_phys_t), ==, (1<<DNODE_SHIFT));
490 ASSERT((size & (sizeof (dnode_phys_t)-1)) == 0);
491
492 while (i < size) {
493 dnode_phys_t *dnp = (void *)(((char *)vbuf) + i);
494 dnode_byteswap(dnp);
495
496 i += DNODE_MIN_SIZE;
497 if (dnp->dn_type != DMU_OT_NONE)
498 i += dnp->dn_extra_slots * DNODE_MIN_SIZE;
499 }
500 }
501
502 void
503 dnode_setbonuslen(dnode_t *dn, int newsize, dmu_tx_t *tx)
504 {
505 ASSERT3U(zfs_refcount_count(&dn->dn_holds), >=, 1);
506
507 dnode_setdirty(dn, tx);
508 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
509 ASSERT3U(newsize, <=, DN_SLOTS_TO_BONUSLEN(dn->dn_num_slots) -
510 (dn->dn_nblkptr-1) * sizeof (blkptr_t));
511
512 if (newsize < dn->dn_bonuslen) {
513 /* clear any data after the end of the new size */
514 size_t diff = dn->dn_bonuslen - newsize;
515 char *data_end = ((char *)dn->dn_bonus->db.db_data) + newsize;
516 memset(data_end, 0, diff);
517 }
518
519 dn->dn_bonuslen = newsize;
520 if (newsize == 0)
521 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = DN_ZERO_BONUSLEN;
522 else
523 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = dn->dn_bonuslen;
524 rw_exit(&dn->dn_struct_rwlock);
525 }
526
527 void
528 dnode_setbonus_type(dnode_t *dn, dmu_object_type_t newtype, dmu_tx_t *tx)
529 {
530 ASSERT3U(zfs_refcount_count(&dn->dn_holds), >=, 1);
531 dnode_setdirty(dn, tx);
532 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
533 dn->dn_bonustype = newtype;
534 dn->dn_next_bonustype[tx->tx_txg & TXG_MASK] = dn->dn_bonustype;
535 rw_exit(&dn->dn_struct_rwlock);
536 }
537
538 void
539 dnode_rm_spill(dnode_t *dn, dmu_tx_t *tx)
540 {
541 ASSERT3U(zfs_refcount_count(&dn->dn_holds), >=, 1);
542 ASSERT(RW_WRITE_HELD(&dn->dn_struct_rwlock));
543 dnode_setdirty(dn, tx);
544 dn->dn_rm_spillblk[tx->tx_txg & TXG_MASK] = DN_KILL_SPILLBLK;
545 dn->dn_have_spill = B_FALSE;
546 }
547
548 static void
549 dnode_setdblksz(dnode_t *dn, int size)
550 {
551 ASSERT0(P2PHASE(size, SPA_MINBLOCKSIZE));
552 ASSERT3U(size, <=, SPA_MAXBLOCKSIZE);
553 ASSERT3U(size, >=, SPA_MINBLOCKSIZE);
554 ASSERT3U(size >> SPA_MINBLOCKSHIFT, <,
555 1<<(sizeof (dn->dn_phys->dn_datablkszsec) * 8));
556 dn->dn_datablksz = size;
557 dn->dn_datablkszsec = size >> SPA_MINBLOCKSHIFT;
558 dn->dn_datablkshift = ISP2(size) ? highbit64(size - 1) : 0;
559 }
560
561 static dnode_t *
562 dnode_create(objset_t *os, dnode_phys_t *dnp, dmu_buf_impl_t *db,
563 uint64_t object, dnode_handle_t *dnh)
564 {
565 dnode_t *dn;
566
567 dn = kmem_cache_alloc(dnode_cache, KM_SLEEP);
568 dn->dn_moved = 0;
569
570 /*
571 * Defer setting dn_objset until the dnode is ready to be a candidate
572 * for the dnode_move() callback.
573 */
574 dn->dn_object = object;
575 dn->dn_dbuf = db;
576 dn->dn_handle = dnh;
577 dn->dn_phys = dnp;
578
579 if (dnp->dn_datablkszsec) {
580 dnode_setdblksz(dn, dnp->dn_datablkszsec << SPA_MINBLOCKSHIFT);
581 } else {
582 dn->dn_datablksz = 0;
583 dn->dn_datablkszsec = 0;
584 dn->dn_datablkshift = 0;
585 }
586 dn->dn_indblkshift = dnp->dn_indblkshift;
587 dn->dn_nlevels = dnp->dn_nlevels;
588 dn->dn_type = dnp->dn_type;
589 dn->dn_nblkptr = dnp->dn_nblkptr;
590 dn->dn_checksum = dnp->dn_checksum;
591 dn->dn_compress = dnp->dn_compress;
592 dn->dn_bonustype = dnp->dn_bonustype;
593 dn->dn_bonuslen = dnp->dn_bonuslen;
594 dn->dn_num_slots = dnp->dn_extra_slots + 1;
595 dn->dn_maxblkid = dnp->dn_maxblkid;
596 dn->dn_have_spill = ((dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) != 0);
597 dn->dn_id_flags = 0;
598
599 dmu_zfetch_init(&dn->dn_zfetch, dn);
600
601 ASSERT(DMU_OT_IS_VALID(dn->dn_phys->dn_type));
602 ASSERT(zrl_is_locked(&dnh->dnh_zrlock));
603 ASSERT(!DN_SLOT_IS_PTR(dnh->dnh_dnode));
604
605 mutex_enter(&os->os_lock);
606
607 /*
608 * Exclude special dnodes from os_dnodes so an empty os_dnodes
609 * signifies that the special dnodes have no references from
610 * their children (the entries in os_dnodes). This allows
611 * dnode_destroy() to easily determine if the last child has
612 * been removed and then complete eviction of the objset.
613 */
614 if (!DMU_OBJECT_IS_SPECIAL(object))
615 list_insert_head(&os->os_dnodes, dn);
616 membar_producer();
617
618 /*
619 * Everything else must be valid before assigning dn_objset
620 * makes the dnode eligible for dnode_move().
621 */
622 dn->dn_objset = os;
623
624 dnh->dnh_dnode = dn;
625 mutex_exit(&os->os_lock);
626
627 arc_space_consume(sizeof (dnode_t), ARC_SPACE_DNODE);
628
629 return (dn);
630 }
631
632 /*
633 * Caller must be holding the dnode handle, which is released upon return.
634 */
635 static void
636 dnode_destroy(dnode_t *dn)
637 {
638 objset_t *os = dn->dn_objset;
639 boolean_t complete_os_eviction = B_FALSE;
640
641 ASSERT((dn->dn_id_flags & DN_ID_NEW_EXIST) == 0);
642
643 mutex_enter(&os->os_lock);
644 POINTER_INVALIDATE(&dn->dn_objset);
645 if (!DMU_OBJECT_IS_SPECIAL(dn->dn_object)) {
646 list_remove(&os->os_dnodes, dn);
647 complete_os_eviction =
648 list_is_empty(&os->os_dnodes) &&
649 list_link_active(&os->os_evicting_node);
650 }
651 mutex_exit(&os->os_lock);
652
653 /* the dnode can no longer move, so we can release the handle */
654 if (!zrl_is_locked(&dn->dn_handle->dnh_zrlock))
655 zrl_remove(&dn->dn_handle->dnh_zrlock);
656
657 dn->dn_allocated_txg = 0;
658 dn->dn_free_txg = 0;
659 dn->dn_assigned_txg = 0;
660 dn->dn_dirty_txg = 0;
661
662 dn->dn_dirtyctx = 0;
663 dn->dn_dirtyctx_firstset = NULL;
664 if (dn->dn_bonus != NULL) {
665 mutex_enter(&dn->dn_bonus->db_mtx);
666 dbuf_destroy(dn->dn_bonus);
667 dn->dn_bonus = NULL;
668 }
669 dn->dn_zio = NULL;
670
671 dn->dn_have_spill = B_FALSE;
672 dn->dn_oldused = 0;
673 dn->dn_oldflags = 0;
674 dn->dn_olduid = 0;
675 dn->dn_oldgid = 0;
676 dn->dn_oldprojid = ZFS_DEFAULT_PROJID;
677 dn->dn_newuid = 0;
678 dn->dn_newgid = 0;
679 dn->dn_newprojid = ZFS_DEFAULT_PROJID;
680 dn->dn_id_flags = 0;
681
682 dmu_zfetch_fini(&dn->dn_zfetch);
683 kmem_cache_free(dnode_cache, dn);
684 arc_space_return(sizeof (dnode_t), ARC_SPACE_DNODE);
685
686 if (complete_os_eviction)
687 dmu_objset_evict_done(os);
688 }
689
690 void
691 dnode_allocate(dnode_t *dn, dmu_object_type_t ot, int blocksize, int ibs,
692 dmu_object_type_t bonustype, int bonuslen, int dn_slots, dmu_tx_t *tx)
693 {
694 int i;
695
696 ASSERT3U(dn_slots, >, 0);
697 ASSERT3U(dn_slots << DNODE_SHIFT, <=,
698 spa_maxdnodesize(dmu_objset_spa(dn->dn_objset)));
699 ASSERT3U(blocksize, <=,
700 spa_maxblocksize(dmu_objset_spa(dn->dn_objset)));
701 if (blocksize == 0)
702 blocksize = 1 << zfs_default_bs;
703 else
704 blocksize = P2ROUNDUP(blocksize, SPA_MINBLOCKSIZE);
705
706 if (ibs == 0)
707 ibs = zfs_default_ibs;
708
709 ibs = MIN(MAX(ibs, DN_MIN_INDBLKSHIFT), DN_MAX_INDBLKSHIFT);
710
711 dprintf("os=%p obj=%llu txg=%llu blocksize=%d ibs=%d dn_slots=%d\n",
712 dn->dn_objset, (u_longlong_t)dn->dn_object,
713 (u_longlong_t)tx->tx_txg, blocksize, ibs, dn_slots);
714 DNODE_STAT_BUMP(dnode_allocate);
715
716 ASSERT(dn->dn_type == DMU_OT_NONE);
717 ASSERT0(memcmp(dn->dn_phys, &dnode_phys_zero, sizeof (dnode_phys_t)));
718 ASSERT(dn->dn_phys->dn_type == DMU_OT_NONE);
719 ASSERT(ot != DMU_OT_NONE);
720 ASSERT(DMU_OT_IS_VALID(ot));
721 ASSERT((bonustype == DMU_OT_NONE && bonuslen == 0) ||
722 (bonustype == DMU_OT_SA && bonuslen == 0) ||
723 (bonustype != DMU_OT_NONE && bonuslen != 0));
724 ASSERT(DMU_OT_IS_VALID(bonustype));
725 ASSERT3U(bonuslen, <=, DN_SLOTS_TO_BONUSLEN(dn_slots));
726 ASSERT(dn->dn_type == DMU_OT_NONE);
727 ASSERT0(dn->dn_maxblkid);
728 ASSERT0(dn->dn_allocated_txg);
729 ASSERT0(dn->dn_assigned_txg);
730 ASSERT(zfs_refcount_is_zero(&dn->dn_tx_holds));
731 ASSERT3U(zfs_refcount_count(&dn->dn_holds), <=, 1);
732 ASSERT(avl_is_empty(&dn->dn_dbufs));
733
734 for (i = 0; i < TXG_SIZE; i++) {
735 ASSERT0(dn->dn_next_nblkptr[i]);
736 ASSERT0(dn->dn_next_nlevels[i]);
737 ASSERT0(dn->dn_next_indblkshift[i]);
738 ASSERT0(dn->dn_next_bonuslen[i]);
739 ASSERT0(dn->dn_next_bonustype[i]);
740 ASSERT0(dn->dn_rm_spillblk[i]);
741 ASSERT0(dn->dn_next_blksz[i]);
742 ASSERT0(dn->dn_next_maxblkid[i]);
743 ASSERT(!multilist_link_active(&dn->dn_dirty_link[i]));
744 ASSERT3P(list_head(&dn->dn_dirty_records[i]), ==, NULL);
745 ASSERT3P(dn->dn_free_ranges[i], ==, NULL);
746 }
747
748 dn->dn_type = ot;
749 dnode_setdblksz(dn, blocksize);
750 dn->dn_indblkshift = ibs;
751 dn->dn_nlevels = 1;
752 dn->dn_num_slots = dn_slots;
753 if (bonustype == DMU_OT_SA) /* Maximize bonus space for SA */
754 dn->dn_nblkptr = 1;
755 else {
756 dn->dn_nblkptr = MIN(DN_MAX_NBLKPTR,
757 1 + ((DN_SLOTS_TO_BONUSLEN(dn_slots) - bonuslen) >>
758 SPA_BLKPTRSHIFT));
759 }
760
761 dn->dn_bonustype = bonustype;
762 dn->dn_bonuslen = bonuslen;
763 dn->dn_checksum = ZIO_CHECKSUM_INHERIT;
764 dn->dn_compress = ZIO_COMPRESS_INHERIT;
765 dn->dn_dirtyctx = 0;
766
767 dn->dn_free_txg = 0;
768 dn->dn_dirtyctx_firstset = NULL;
769 dn->dn_dirty_txg = 0;
770
771 dn->dn_allocated_txg = tx->tx_txg;
772 dn->dn_id_flags = 0;
773
774 dnode_setdirty(dn, tx);
775 dn->dn_next_indblkshift[tx->tx_txg & TXG_MASK] = ibs;
776 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = dn->dn_bonuslen;
777 dn->dn_next_bonustype[tx->tx_txg & TXG_MASK] = dn->dn_bonustype;
778 dn->dn_next_blksz[tx->tx_txg & TXG_MASK] = dn->dn_datablksz;
779 }
780
781 void
782 dnode_reallocate(dnode_t *dn, dmu_object_type_t ot, int blocksize,
783 dmu_object_type_t bonustype, int bonuslen, int dn_slots,
784 boolean_t keep_spill, dmu_tx_t *tx)
785 {
786 int nblkptr;
787
788 ASSERT3U(blocksize, >=, SPA_MINBLOCKSIZE);
789 ASSERT3U(blocksize, <=,
790 spa_maxblocksize(dmu_objset_spa(dn->dn_objset)));
791 ASSERT0(blocksize % SPA_MINBLOCKSIZE);
792 ASSERT(dn->dn_object != DMU_META_DNODE_OBJECT || dmu_tx_private_ok(tx));
793 ASSERT(tx->tx_txg != 0);
794 ASSERT((bonustype == DMU_OT_NONE && bonuslen == 0) ||
795 (bonustype != DMU_OT_NONE && bonuslen != 0) ||
796 (bonustype == DMU_OT_SA && bonuslen == 0));
797 ASSERT(DMU_OT_IS_VALID(bonustype));
798 ASSERT3U(bonuslen, <=,
799 DN_BONUS_SIZE(spa_maxdnodesize(dmu_objset_spa(dn->dn_objset))));
800 ASSERT3U(bonuslen, <=, DN_BONUS_SIZE(dn_slots << DNODE_SHIFT));
801
802 dnode_free_interior_slots(dn);
803 DNODE_STAT_BUMP(dnode_reallocate);
804
805 /* clean up any unreferenced dbufs */
806 dnode_evict_dbufs(dn);
807
808 dn->dn_id_flags = 0;
809
810 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
811 dnode_setdirty(dn, tx);
812 if (dn->dn_datablksz != blocksize) {
813 /* change blocksize */
814 ASSERT0(dn->dn_maxblkid);
815 ASSERT(BP_IS_HOLE(&dn->dn_phys->dn_blkptr[0]) ||
816 dnode_block_freed(dn, 0));
817
818 dnode_setdblksz(dn, blocksize);
819 dn->dn_next_blksz[tx->tx_txg & TXG_MASK] = blocksize;
820 }
821 if (dn->dn_bonuslen != bonuslen)
822 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = bonuslen;
823
824 if (bonustype == DMU_OT_SA) /* Maximize bonus space for SA */
825 nblkptr = 1;
826 else
827 nblkptr = MIN(DN_MAX_NBLKPTR,
828 1 + ((DN_SLOTS_TO_BONUSLEN(dn_slots) - bonuslen) >>
829 SPA_BLKPTRSHIFT));
830 if (dn->dn_bonustype != bonustype)
831 dn->dn_next_bonustype[tx->tx_txg & TXG_MASK] = bonustype;
832 if (dn->dn_nblkptr != nblkptr)
833 dn->dn_next_nblkptr[tx->tx_txg & TXG_MASK] = nblkptr;
834 if (dn->dn_phys->dn_flags & DNODE_FLAG_SPILL_BLKPTR && !keep_spill) {
835 dbuf_rm_spill(dn, tx);
836 dnode_rm_spill(dn, tx);
837 }
838
839 rw_exit(&dn->dn_struct_rwlock);
840
841 /* change type */
842 dn->dn_type = ot;
843
844 /* change bonus size and type */
845 mutex_enter(&dn->dn_mtx);
846 dn->dn_bonustype = bonustype;
847 dn->dn_bonuslen = bonuslen;
848 dn->dn_num_slots = dn_slots;
849 dn->dn_nblkptr = nblkptr;
850 dn->dn_checksum = ZIO_CHECKSUM_INHERIT;
851 dn->dn_compress = ZIO_COMPRESS_INHERIT;
852 ASSERT3U(dn->dn_nblkptr, <=, DN_MAX_NBLKPTR);
853
854 /* fix up the bonus db_size */
855 if (dn->dn_bonus) {
856 dn->dn_bonus->db.db_size =
857 DN_SLOTS_TO_BONUSLEN(dn->dn_num_slots) -
858 (dn->dn_nblkptr-1) * sizeof (blkptr_t);
859 ASSERT(dn->dn_bonuslen <= dn->dn_bonus->db.db_size);
860 }
861
862 dn->dn_allocated_txg = tx->tx_txg;
863 mutex_exit(&dn->dn_mtx);
864 }
865
866 #ifdef _KERNEL
867 static void
868 dnode_move_impl(dnode_t *odn, dnode_t *ndn)
869 {
870 ASSERT(!RW_LOCK_HELD(&odn->dn_struct_rwlock));
871 ASSERT(MUTEX_NOT_HELD(&odn->dn_mtx));
872 ASSERT(MUTEX_NOT_HELD(&odn->dn_dbufs_mtx));
873
874 /* Copy fields. */
875 ndn->dn_objset = odn->dn_objset;
876 ndn->dn_object = odn->dn_object;
877 ndn->dn_dbuf = odn->dn_dbuf;
878 ndn->dn_handle = odn->dn_handle;
879 ndn->dn_phys = odn->dn_phys;
880 ndn->dn_type = odn->dn_type;
881 ndn->dn_bonuslen = odn->dn_bonuslen;
882 ndn->dn_bonustype = odn->dn_bonustype;
883 ndn->dn_nblkptr = odn->dn_nblkptr;
884 ndn->dn_checksum = odn->dn_checksum;
885 ndn->dn_compress = odn->dn_compress;
886 ndn->dn_nlevels = odn->dn_nlevels;
887 ndn->dn_indblkshift = odn->dn_indblkshift;
888 ndn->dn_datablkshift = odn->dn_datablkshift;
889 ndn->dn_datablkszsec = odn->dn_datablkszsec;
890 ndn->dn_datablksz = odn->dn_datablksz;
891 ndn->dn_maxblkid = odn->dn_maxblkid;
892 ndn->dn_num_slots = odn->dn_num_slots;
893 memcpy(ndn->dn_next_type, odn->dn_next_type,
894 sizeof (odn->dn_next_type));
895 memcpy(ndn->dn_next_nblkptr, odn->dn_next_nblkptr,
896 sizeof (odn->dn_next_nblkptr));
897 memcpy(ndn->dn_next_nlevels, odn->dn_next_nlevels,
898 sizeof (odn->dn_next_nlevels));
899 memcpy(ndn->dn_next_indblkshift, odn->dn_next_indblkshift,
900 sizeof (odn->dn_next_indblkshift));
901 memcpy(ndn->dn_next_bonustype, odn->dn_next_bonustype,
902 sizeof (odn->dn_next_bonustype));
903 memcpy(ndn->dn_rm_spillblk, odn->dn_rm_spillblk,
904 sizeof (odn->dn_rm_spillblk));
905 memcpy(ndn->dn_next_bonuslen, odn->dn_next_bonuslen,
906 sizeof (odn->dn_next_bonuslen));
907 memcpy(ndn->dn_next_blksz, odn->dn_next_blksz,
908 sizeof (odn->dn_next_blksz));
909 memcpy(ndn->dn_next_maxblkid, odn->dn_next_maxblkid,
910 sizeof (odn->dn_next_maxblkid));
911 for (int i = 0; i < TXG_SIZE; i++) {
912 list_move_tail(&ndn->dn_dirty_records[i],
913 &odn->dn_dirty_records[i]);
914 }
915 memcpy(ndn->dn_free_ranges, odn->dn_free_ranges,
916 sizeof (odn->dn_free_ranges));
917 ndn->dn_allocated_txg = odn->dn_allocated_txg;
918 ndn->dn_free_txg = odn->dn_free_txg;
919 ndn->dn_assigned_txg = odn->dn_assigned_txg;
920 ndn->dn_dirty_txg = odn->dn_dirty_txg;
921 ndn->dn_dirtyctx = odn->dn_dirtyctx;
922 ndn->dn_dirtyctx_firstset = odn->dn_dirtyctx_firstset;
923 ASSERT(zfs_refcount_count(&odn->dn_tx_holds) == 0);
924 zfs_refcount_transfer(&ndn->dn_holds, &odn->dn_holds);
925 ASSERT(avl_is_empty(&ndn->dn_dbufs));
926 avl_swap(&ndn->dn_dbufs, &odn->dn_dbufs);
927 ndn->dn_dbufs_count = odn->dn_dbufs_count;
928 ndn->dn_bonus = odn->dn_bonus;
929 ndn->dn_have_spill = odn->dn_have_spill;
930 ndn->dn_zio = odn->dn_zio;
931 ndn->dn_oldused = odn->dn_oldused;
932 ndn->dn_oldflags = odn->dn_oldflags;
933 ndn->dn_olduid = odn->dn_olduid;
934 ndn->dn_oldgid = odn->dn_oldgid;
935 ndn->dn_oldprojid = odn->dn_oldprojid;
936 ndn->dn_newuid = odn->dn_newuid;
937 ndn->dn_newgid = odn->dn_newgid;
938 ndn->dn_newprojid = odn->dn_newprojid;
939 ndn->dn_id_flags = odn->dn_id_flags;
940 dmu_zfetch_init(&ndn->dn_zfetch, ndn);
941
942 /*
943 * Update back pointers. Updating the handle fixes the back pointer of
944 * every descendant dbuf as well as the bonus dbuf.
945 */
946 ASSERT(ndn->dn_handle->dnh_dnode == odn);
947 ndn->dn_handle->dnh_dnode = ndn;
948
949 /*
950 * Invalidate the original dnode by clearing all of its back pointers.
951 */
952 odn->dn_dbuf = NULL;
953 odn->dn_handle = NULL;
954 avl_create(&odn->dn_dbufs, dbuf_compare, sizeof (dmu_buf_impl_t),
955 offsetof(dmu_buf_impl_t, db_link));
956 odn->dn_dbufs_count = 0;
957 odn->dn_bonus = NULL;
958 dmu_zfetch_fini(&odn->dn_zfetch);
959
960 /*
961 * Set the low bit of the objset pointer to ensure that dnode_move()
962 * recognizes the dnode as invalid in any subsequent callback.
963 */
964 POINTER_INVALIDATE(&odn->dn_objset);
965
966 /*
967 * Satisfy the destructor.
968 */
969 for (int i = 0; i < TXG_SIZE; i++) {
970 list_create(&odn->dn_dirty_records[i],
971 sizeof (dbuf_dirty_record_t),
972 offsetof(dbuf_dirty_record_t, dr_dirty_node));
973 odn->dn_free_ranges[i] = NULL;
974 odn->dn_next_nlevels[i] = 0;
975 odn->dn_next_indblkshift[i] = 0;
976 odn->dn_next_bonustype[i] = 0;
977 odn->dn_rm_spillblk[i] = 0;
978 odn->dn_next_bonuslen[i] = 0;
979 odn->dn_next_blksz[i] = 0;
980 }
981 odn->dn_allocated_txg = 0;
982 odn->dn_free_txg = 0;
983 odn->dn_assigned_txg = 0;
984 odn->dn_dirty_txg = 0;
985 odn->dn_dirtyctx = 0;
986 odn->dn_dirtyctx_firstset = NULL;
987 odn->dn_have_spill = B_FALSE;
988 odn->dn_zio = NULL;
989 odn->dn_oldused = 0;
990 odn->dn_oldflags = 0;
991 odn->dn_olduid = 0;
992 odn->dn_oldgid = 0;
993 odn->dn_oldprojid = ZFS_DEFAULT_PROJID;
994 odn->dn_newuid = 0;
995 odn->dn_newgid = 0;
996 odn->dn_newprojid = ZFS_DEFAULT_PROJID;
997 odn->dn_id_flags = 0;
998
999 /*
1000 * Mark the dnode.
1001 */
1002 ndn->dn_moved = 1;
1003 odn->dn_moved = (uint8_t)-1;
1004 }
1005
1006 static kmem_cbrc_t
1007 dnode_move(void *buf, void *newbuf, size_t size, void *arg)
1008 {
1009 dnode_t *odn = buf, *ndn = newbuf;
1010 objset_t *os;
1011 int64_t refcount;
1012 uint32_t dbufs;
1013
1014 /*
1015 * The dnode is on the objset's list of known dnodes if the objset
1016 * pointer is valid. We set the low bit of the objset pointer when
1017 * freeing the dnode to invalidate it, and the memory patterns written
1018 * by kmem (baddcafe and deadbeef) set at least one of the two low bits.
1019 * A newly created dnode sets the objset pointer last of all to indicate
1020 * that the dnode is known and in a valid state to be moved by this
1021 * function.
1022 */
1023 os = odn->dn_objset;
1024 if (!POINTER_IS_VALID(os)) {
1025 DNODE_STAT_BUMP(dnode_move_invalid);
1026 return (KMEM_CBRC_DONT_KNOW);
1027 }
1028
1029 /*
1030 * Ensure that the objset does not go away during the move.
1031 */
1032 rw_enter(&os_lock, RW_WRITER);
1033 if (os != odn->dn_objset) {
1034 rw_exit(&os_lock);
1035 DNODE_STAT_BUMP(dnode_move_recheck1);
1036 return (KMEM_CBRC_DONT_KNOW);
1037 }
1038
1039 /*
1040 * If the dnode is still valid, then so is the objset. We know that no
1041 * valid objset can be freed while we hold os_lock, so we can safely
1042 * ensure that the objset remains in use.
1043 */
1044 mutex_enter(&os->os_lock);
1045
1046 /*
1047 * Recheck the objset pointer in case the dnode was removed just before
1048 * acquiring the lock.
1049 */
1050 if (os != odn->dn_objset) {
1051 mutex_exit(&os->os_lock);
1052 rw_exit(&os_lock);
1053 DNODE_STAT_BUMP(dnode_move_recheck2);
1054 return (KMEM_CBRC_DONT_KNOW);
1055 }
1056
1057 /*
1058 * At this point we know that as long as we hold os->os_lock, the dnode
1059 * cannot be freed and fields within the dnode can be safely accessed.
1060 * The objset listing this dnode cannot go away as long as this dnode is
1061 * on its list.
1062 */
1063 rw_exit(&os_lock);
1064 if (DMU_OBJECT_IS_SPECIAL(odn->dn_object)) {
1065 mutex_exit(&os->os_lock);
1066 DNODE_STAT_BUMP(dnode_move_special);
1067 return (KMEM_CBRC_NO);
1068 }
1069 ASSERT(odn->dn_dbuf != NULL); /* only "special" dnodes have no parent */
1070
1071 /*
1072 * Lock the dnode handle to prevent the dnode from obtaining any new
1073 * holds. This also prevents the descendant dbufs and the bonus dbuf
1074 * from accessing the dnode, so that we can discount their holds. The
1075 * handle is safe to access because we know that while the dnode cannot
1076 * go away, neither can its handle. Once we hold dnh_zrlock, we can
1077 * safely move any dnode referenced only by dbufs.
1078 */
1079 if (!zrl_tryenter(&odn->dn_handle->dnh_zrlock)) {
1080 mutex_exit(&os->os_lock);
1081 DNODE_STAT_BUMP(dnode_move_handle);
1082 return (KMEM_CBRC_LATER);
1083 }
1084
1085 /*
1086 * Ensure a consistent view of the dnode's holds and the dnode's dbufs.
1087 * We need to guarantee that there is a hold for every dbuf in order to
1088 * determine whether the dnode is actively referenced. Falsely matching
1089 * a dbuf to an active hold would lead to an unsafe move. It's possible
1090 * that a thread already having an active dnode hold is about to add a
1091 * dbuf, and we can't compare hold and dbuf counts while the add is in
1092 * progress.
1093 */
1094 if (!rw_tryenter(&odn->dn_struct_rwlock, RW_WRITER)) {
1095 zrl_exit(&odn->dn_handle->dnh_zrlock);
1096 mutex_exit(&os->os_lock);
1097 DNODE_STAT_BUMP(dnode_move_rwlock);
1098 return (KMEM_CBRC_LATER);
1099 }
1100
1101 /*
1102 * A dbuf may be removed (evicted) without an active dnode hold. In that
1103 * case, the dbuf count is decremented under the handle lock before the
1104 * dbuf's hold is released. This order ensures that if we count the hold
1105 * after the dbuf is removed but before its hold is released, we will
1106 * treat the unmatched hold as active and exit safely. If we count the
1107 * hold before the dbuf is removed, the hold is discounted, and the
1108 * removal is blocked until the move completes.
1109 */
1110 refcount = zfs_refcount_count(&odn->dn_holds);
1111 ASSERT(refcount >= 0);
1112 dbufs = DN_DBUFS_COUNT(odn);
1113
1114 /* We can't have more dbufs than dnode holds. */
1115 ASSERT3U(dbufs, <=, refcount);
1116 DTRACE_PROBE3(dnode__move, dnode_t *, odn, int64_t, refcount,
1117 uint32_t, dbufs);
1118
1119 if (refcount > dbufs) {
1120 rw_exit(&odn->dn_struct_rwlock);
1121 zrl_exit(&odn->dn_handle->dnh_zrlock);
1122 mutex_exit(&os->os_lock);
1123 DNODE_STAT_BUMP(dnode_move_active);
1124 return (KMEM_CBRC_LATER);
1125 }
1126
1127 rw_exit(&odn->dn_struct_rwlock);
1128
1129 /*
1130 * At this point we know that anyone with a hold on the dnode is not
1131 * actively referencing it. The dnode is known and in a valid state to
1132 * move. We're holding the locks needed to execute the critical section.
1133 */
1134 dnode_move_impl(odn, ndn);
1135
1136 list_link_replace(&odn->dn_link, &ndn->dn_link);
1137 /* If the dnode was safe to move, the refcount cannot have changed. */
1138 ASSERT(refcount == zfs_refcount_count(&ndn->dn_holds));
1139 ASSERT(dbufs == DN_DBUFS_COUNT(ndn));
1140 zrl_exit(&ndn->dn_handle->dnh_zrlock); /* handle has moved */
1141 mutex_exit(&os->os_lock);
1142
1143 return (KMEM_CBRC_YES);
1144 }
1145 #endif /* _KERNEL */
1146
1147 static void
1148 dnode_slots_hold(dnode_children_t *children, int idx, int slots)
1149 {
1150 ASSERT3S(idx + slots, <=, DNODES_PER_BLOCK);
1151
1152 for (int i = idx; i < idx + slots; i++) {
1153 dnode_handle_t *dnh = &children->dnc_children[i];
1154 zrl_add(&dnh->dnh_zrlock);
1155 }
1156 }
1157
1158 static void
1159 dnode_slots_rele(dnode_children_t *children, int idx, int slots)
1160 {
1161 ASSERT3S(idx + slots, <=, DNODES_PER_BLOCK);
1162
1163 for (int i = idx; i < idx + slots; i++) {
1164 dnode_handle_t *dnh = &children->dnc_children[i];
1165
1166 if (zrl_is_locked(&dnh->dnh_zrlock))
1167 zrl_exit(&dnh->dnh_zrlock);
1168 else
1169 zrl_remove(&dnh->dnh_zrlock);
1170 }
1171 }
1172
1173 static int
1174 dnode_slots_tryenter(dnode_children_t *children, int idx, int slots)
1175 {
1176 ASSERT3S(idx + slots, <=, DNODES_PER_BLOCK);
1177
1178 for (int i = idx; i < idx + slots; i++) {
1179 dnode_handle_t *dnh = &children->dnc_children[i];
1180
1181 if (!zrl_tryenter(&dnh->dnh_zrlock)) {
1182 for (int j = idx; j < i; j++) {
1183 dnh = &children->dnc_children[j];
1184 zrl_exit(&dnh->dnh_zrlock);
1185 }
1186
1187 return (0);
1188 }
1189 }
1190
1191 return (1);
1192 }
1193
1194 static void
1195 dnode_set_slots(dnode_children_t *children, int idx, int slots, void *ptr)
1196 {
1197 ASSERT3S(idx + slots, <=, DNODES_PER_BLOCK);
1198
1199 for (int i = idx; i < idx + slots; i++) {
1200 dnode_handle_t *dnh = &children->dnc_children[i];
1201 dnh->dnh_dnode = ptr;
1202 }
1203 }
1204
1205 static boolean_t
1206 dnode_check_slots_free(dnode_children_t *children, int idx, int slots)
1207 {
1208 ASSERT3S(idx + slots, <=, DNODES_PER_BLOCK);
1209
1210 /*
1211 * If all dnode slots are either already free or
1212 * evictable return B_TRUE.
1213 */
1214 for (int i = idx; i < idx + slots; i++) {
1215 dnode_handle_t *dnh = &children->dnc_children[i];
1216 dnode_t *dn = dnh->dnh_dnode;
1217
1218 if (dn == DN_SLOT_FREE) {
1219 continue;
1220 } else if (DN_SLOT_IS_PTR(dn)) {
1221 mutex_enter(&dn->dn_mtx);
1222 boolean_t can_free = (dn->dn_type == DMU_OT_NONE &&
1223 zfs_refcount_is_zero(&dn->dn_holds) &&
1224 !DNODE_IS_DIRTY(dn));
1225 mutex_exit(&dn->dn_mtx);
1226
1227 if (!can_free)
1228 return (B_FALSE);
1229 else
1230 continue;
1231 } else {
1232 return (B_FALSE);
1233 }
1234 }
1235
1236 return (B_TRUE);
1237 }
1238
1239 static void
1240 dnode_reclaim_slots(dnode_children_t *children, int idx, int slots)
1241 {
1242 ASSERT3S(idx + slots, <=, DNODES_PER_BLOCK);
1243
1244 for (int i = idx; i < idx + slots; i++) {
1245 dnode_handle_t *dnh = &children->dnc_children[i];
1246
1247 ASSERT(zrl_is_locked(&dnh->dnh_zrlock));
1248
1249 if (DN_SLOT_IS_PTR(dnh->dnh_dnode)) {
1250 ASSERT3S(dnh->dnh_dnode->dn_type, ==, DMU_OT_NONE);
1251 dnode_destroy(dnh->dnh_dnode);
1252 dnh->dnh_dnode = DN_SLOT_FREE;
1253 }
1254 }
1255 }
1256
1257 void
1258 dnode_free_interior_slots(dnode_t *dn)
1259 {
1260 dnode_children_t *children = dmu_buf_get_user(&dn->dn_dbuf->db);
1261 int epb = dn->dn_dbuf->db.db_size >> DNODE_SHIFT;
1262 int idx = (dn->dn_object & (epb - 1)) + 1;
1263 int slots = dn->dn_num_slots - 1;
1264
1265 if (slots == 0)
1266 return;
1267
1268 ASSERT3S(idx + slots, <=, DNODES_PER_BLOCK);
1269
1270 while (!dnode_slots_tryenter(children, idx, slots)) {
1271 DNODE_STAT_BUMP(dnode_free_interior_lock_retry);
1272 kpreempt(KPREEMPT_SYNC);
1273 }
1274
1275 dnode_set_slots(children, idx, slots, DN_SLOT_FREE);
1276 dnode_slots_rele(children, idx, slots);
1277 }
1278
1279 void
1280 dnode_special_close(dnode_handle_t *dnh)
1281 {
1282 dnode_t *dn = dnh->dnh_dnode;
1283
1284 /*
1285 * Ensure dnode_rele_and_unlock() has released dn_mtx, after final
1286 * zfs_refcount_remove()
1287 */
1288 mutex_enter(&dn->dn_mtx);
1289 if (zfs_refcount_count(&dn->dn_holds) > 0)
1290 cv_wait(&dn->dn_nodnholds, &dn->dn_mtx);
1291 mutex_exit(&dn->dn_mtx);
1292 ASSERT3U(zfs_refcount_count(&dn->dn_holds), ==, 0);
1293
1294 ASSERT(dn->dn_dbuf == NULL ||
1295 dmu_buf_get_user(&dn->dn_dbuf->db) == NULL);
1296 zrl_add(&dnh->dnh_zrlock);
1297 dnode_destroy(dn); /* implicit zrl_remove() */
1298 zrl_destroy(&dnh->dnh_zrlock);
1299 dnh->dnh_dnode = NULL;
1300 }
1301
1302 void
1303 dnode_special_open(objset_t *os, dnode_phys_t *dnp, uint64_t object,
1304 dnode_handle_t *dnh)
1305 {
1306 dnode_t *dn;
1307
1308 zrl_init(&dnh->dnh_zrlock);
1309 VERIFY3U(1, ==, zrl_tryenter(&dnh->dnh_zrlock));
1310
1311 dn = dnode_create(os, dnp, NULL, object, dnh);
1312 DNODE_VERIFY(dn);
1313
1314 zrl_exit(&dnh->dnh_zrlock);
1315 }
1316
1317 static void
1318 dnode_buf_evict_async(void *dbu)
1319 {
1320 dnode_children_t *dnc = dbu;
1321
1322 DNODE_STAT_BUMP(dnode_buf_evict);
1323
1324 for (int i = 0; i < dnc->dnc_count; i++) {
1325 dnode_handle_t *dnh = &dnc->dnc_children[i];
1326 dnode_t *dn;
1327
1328 /*
1329 * The dnode handle lock guards against the dnode moving to
1330 * another valid address, so there is no need here to guard
1331 * against changes to or from NULL.
1332 */
1333 if (!DN_SLOT_IS_PTR(dnh->dnh_dnode)) {
1334 zrl_destroy(&dnh->dnh_zrlock);
1335 dnh->dnh_dnode = DN_SLOT_UNINIT;
1336 continue;
1337 }
1338
1339 zrl_add(&dnh->dnh_zrlock);
1340 dn = dnh->dnh_dnode;
1341 /*
1342 * If there are holds on this dnode, then there should
1343 * be holds on the dnode's containing dbuf as well; thus
1344 * it wouldn't be eligible for eviction and this function
1345 * would not have been called.
1346 */
1347 ASSERT(zfs_refcount_is_zero(&dn->dn_holds));
1348 ASSERT(zfs_refcount_is_zero(&dn->dn_tx_holds));
1349
1350 dnode_destroy(dn); /* implicit zrl_remove() for first slot */
1351 zrl_destroy(&dnh->dnh_zrlock);
1352 dnh->dnh_dnode = DN_SLOT_UNINIT;
1353 }
1354 kmem_free(dnc, sizeof (dnode_children_t) +
1355 dnc->dnc_count * sizeof (dnode_handle_t));
1356 }
1357
1358 /*
1359 * When the DNODE_MUST_BE_FREE flag is set, the "slots" parameter is used
1360 * to ensure the hole at the specified object offset is large enough to
1361 * hold the dnode being created. The slots parameter is also used to ensure
1362 * a dnode does not span multiple dnode blocks. In both of these cases, if
1363 * a failure occurs, ENOSPC is returned. Keep in mind, these failure cases
1364 * are only possible when using DNODE_MUST_BE_FREE.
1365 *
1366 * If the DNODE_MUST_BE_ALLOCATED flag is set, "slots" must be 0.
1367 * dnode_hold_impl() will check if the requested dnode is already consumed
1368 * as an extra dnode slot by an large dnode, in which case it returns
1369 * ENOENT.
1370 *
1371 * If the DNODE_DRY_RUN flag is set, we don't actually hold the dnode, just
1372 * return whether the hold would succeed or not. tag and dnp should set to
1373 * NULL in this case.
1374 *
1375 * errors:
1376 * EINVAL - Invalid object number or flags.
1377 * ENOSPC - Hole too small to fulfill "slots" request (DNODE_MUST_BE_FREE)
1378 * EEXIST - Refers to an allocated dnode (DNODE_MUST_BE_FREE)
1379 * - Refers to a freeing dnode (DNODE_MUST_BE_FREE)
1380 * - Refers to an interior dnode slot (DNODE_MUST_BE_ALLOCATED)
1381 * ENOENT - The requested dnode is not allocated (DNODE_MUST_BE_ALLOCATED)
1382 * - The requested dnode is being freed (DNODE_MUST_BE_ALLOCATED)
1383 * EIO - I/O error when reading the meta dnode dbuf.
1384 *
1385 * succeeds even for free dnodes.
1386 */
1387 int
1388 dnode_hold_impl(objset_t *os, uint64_t object, int flag, int slots,
1389 const void *tag, dnode_t **dnp)
1390 {
1391 int epb, idx, err;
1392 int drop_struct_lock = FALSE;
1393 int type;
1394 uint64_t blk;
1395 dnode_t *mdn, *dn;
1396 dmu_buf_impl_t *db;
1397 dnode_children_t *dnc;
1398 dnode_phys_t *dn_block;
1399 dnode_handle_t *dnh;
1400
1401 ASSERT(!(flag & DNODE_MUST_BE_ALLOCATED) || (slots == 0));
1402 ASSERT(!(flag & DNODE_MUST_BE_FREE) || (slots > 0));
1403 IMPLY(flag & DNODE_DRY_RUN, (tag == NULL) && (dnp == NULL));
1404
1405 /*
1406 * If you are holding the spa config lock as writer, you shouldn't
1407 * be asking the DMU to do *anything* unless it's the root pool
1408 * which may require us to read from the root filesystem while
1409 * holding some (not all) of the locks as writer.
1410 */
1411 ASSERT(spa_config_held(os->os_spa, SCL_ALL, RW_WRITER) == 0 ||
1412 (spa_is_root(os->os_spa) &&
1413 spa_config_held(os->os_spa, SCL_STATE, RW_WRITER)));
1414
1415 ASSERT((flag & DNODE_MUST_BE_ALLOCATED) || (flag & DNODE_MUST_BE_FREE));
1416
1417 if (object == DMU_USERUSED_OBJECT || object == DMU_GROUPUSED_OBJECT ||
1418 object == DMU_PROJECTUSED_OBJECT) {
1419 if (object == DMU_USERUSED_OBJECT)
1420 dn = DMU_USERUSED_DNODE(os);
1421 else if (object == DMU_GROUPUSED_OBJECT)
1422 dn = DMU_GROUPUSED_DNODE(os);
1423 else
1424 dn = DMU_PROJECTUSED_DNODE(os);
1425 if (dn == NULL)
1426 return (SET_ERROR(ENOENT));
1427 type = dn->dn_type;
1428 if ((flag & DNODE_MUST_BE_ALLOCATED) && type == DMU_OT_NONE)
1429 return (SET_ERROR(ENOENT));
1430 if ((flag & DNODE_MUST_BE_FREE) && type != DMU_OT_NONE)
1431 return (SET_ERROR(EEXIST));
1432 DNODE_VERIFY(dn);
1433 /* Don't actually hold if dry run, just return 0 */
1434 if (!(flag & DNODE_DRY_RUN)) {
1435 (void) zfs_refcount_add(&dn->dn_holds, tag);
1436 *dnp = dn;
1437 }
1438 return (0);
1439 }
1440
1441 if (object == 0 || object >= DN_MAX_OBJECT)
1442 return (SET_ERROR(EINVAL));
1443
1444 mdn = DMU_META_DNODE(os);
1445 ASSERT(mdn->dn_object == DMU_META_DNODE_OBJECT);
1446
1447 DNODE_VERIFY(mdn);
1448
1449 if (!RW_WRITE_HELD(&mdn->dn_struct_rwlock)) {
1450 rw_enter(&mdn->dn_struct_rwlock, RW_READER);
1451 drop_struct_lock = TRUE;
1452 }
1453
1454 blk = dbuf_whichblock(mdn, 0, object * sizeof (dnode_phys_t));
1455 db = dbuf_hold(mdn, blk, FTAG);
1456 if (drop_struct_lock)
1457 rw_exit(&mdn->dn_struct_rwlock);
1458 if (db == NULL) {
1459 DNODE_STAT_BUMP(dnode_hold_dbuf_hold);
1460 return (SET_ERROR(EIO));
1461 }
1462
1463 /*
1464 * We do not need to decrypt to read the dnode so it doesn't matter
1465 * if we get the encrypted or decrypted version.
1466 */
1467 err = dbuf_read(db, NULL, DB_RF_CANFAIL |
1468 DB_RF_NO_DECRYPT | DB_RF_NOPREFETCH);
1469 if (err) {
1470 DNODE_STAT_BUMP(dnode_hold_dbuf_read);
1471 dbuf_rele(db, FTAG);
1472 return (err);
1473 }
1474
1475 ASSERT3U(db->db.db_size, >=, 1<<DNODE_SHIFT);
1476 epb = db->db.db_size >> DNODE_SHIFT;
1477
1478 idx = object & (epb - 1);
1479 dn_block = (dnode_phys_t *)db->db.db_data;
1480
1481 ASSERT(DB_DNODE(db)->dn_type == DMU_OT_DNODE);
1482 dnc = dmu_buf_get_user(&db->db);
1483 dnh = NULL;
1484 if (dnc == NULL) {
1485 dnode_children_t *winner;
1486 int skip = 0;
1487
1488 dnc = kmem_zalloc(sizeof (dnode_children_t) +
1489 epb * sizeof (dnode_handle_t), KM_SLEEP);
1490 dnc->dnc_count = epb;
1491 dnh = &dnc->dnc_children[0];
1492
1493 /* Initialize dnode slot status from dnode_phys_t */
1494 for (int i = 0; i < epb; i++) {
1495 zrl_init(&dnh[i].dnh_zrlock);
1496
1497 if (skip) {
1498 skip--;
1499 continue;
1500 }
1501
1502 if (dn_block[i].dn_type != DMU_OT_NONE) {
1503 int interior = dn_block[i].dn_extra_slots;
1504
1505 dnode_set_slots(dnc, i, 1, DN_SLOT_ALLOCATED);
1506 dnode_set_slots(dnc, i + 1, interior,
1507 DN_SLOT_INTERIOR);
1508 skip = interior;
1509 } else {
1510 dnh[i].dnh_dnode = DN_SLOT_FREE;
1511 skip = 0;
1512 }
1513 }
1514
1515 dmu_buf_init_user(&dnc->dnc_dbu, NULL,
1516 dnode_buf_evict_async, NULL);
1517 winner = dmu_buf_set_user(&db->db, &dnc->dnc_dbu);
1518 if (winner != NULL) {
1519
1520 for (int i = 0; i < epb; i++)
1521 zrl_destroy(&dnh[i].dnh_zrlock);
1522
1523 kmem_free(dnc, sizeof (dnode_children_t) +
1524 epb * sizeof (dnode_handle_t));
1525 dnc = winner;
1526 }
1527 }
1528
1529 ASSERT(dnc->dnc_count == epb);
1530
1531 if (flag & DNODE_MUST_BE_ALLOCATED) {
1532 slots = 1;
1533
1534 dnode_slots_hold(dnc, idx, slots);
1535 dnh = &dnc->dnc_children[idx];
1536
1537 if (DN_SLOT_IS_PTR(dnh->dnh_dnode)) {
1538 dn = dnh->dnh_dnode;
1539 } else if (dnh->dnh_dnode == DN_SLOT_INTERIOR) {
1540 DNODE_STAT_BUMP(dnode_hold_alloc_interior);
1541 dnode_slots_rele(dnc, idx, slots);
1542 dbuf_rele(db, FTAG);
1543 return (SET_ERROR(EEXIST));
1544 } else if (dnh->dnh_dnode != DN_SLOT_ALLOCATED) {
1545 DNODE_STAT_BUMP(dnode_hold_alloc_misses);
1546 dnode_slots_rele(dnc, idx, slots);
1547 dbuf_rele(db, FTAG);
1548 return (SET_ERROR(ENOENT));
1549 } else {
1550 dnode_slots_rele(dnc, idx, slots);
1551 while (!dnode_slots_tryenter(dnc, idx, slots)) {
1552 DNODE_STAT_BUMP(dnode_hold_alloc_lock_retry);
1553 kpreempt(KPREEMPT_SYNC);
1554 }
1555
1556 /*
1557 * Someone else won the race and called dnode_create()
1558 * after we checked DN_SLOT_IS_PTR() above but before
1559 * we acquired the lock.
1560 */
1561 if (DN_SLOT_IS_PTR(dnh->dnh_dnode)) {
1562 DNODE_STAT_BUMP(dnode_hold_alloc_lock_misses);
1563 dn = dnh->dnh_dnode;
1564 } else {
1565 dn = dnode_create(os, dn_block + idx, db,
1566 object, dnh);
1567 }
1568 }
1569
1570 mutex_enter(&dn->dn_mtx);
1571 if (dn->dn_type == DMU_OT_NONE || dn->dn_free_txg != 0) {
1572 DNODE_STAT_BUMP(dnode_hold_alloc_type_none);
1573 mutex_exit(&dn->dn_mtx);
1574 dnode_slots_rele(dnc, idx, slots);
1575 dbuf_rele(db, FTAG);
1576 return (SET_ERROR(ENOENT));
1577 }
1578
1579 /* Don't actually hold if dry run, just return 0 */
1580 if (flag & DNODE_DRY_RUN) {
1581 mutex_exit(&dn->dn_mtx);
1582 dnode_slots_rele(dnc, idx, slots);
1583 dbuf_rele(db, FTAG);
1584 return (0);
1585 }
1586
1587 DNODE_STAT_BUMP(dnode_hold_alloc_hits);
1588 } else if (flag & DNODE_MUST_BE_FREE) {
1589
1590 if (idx + slots - 1 >= DNODES_PER_BLOCK) {
1591 DNODE_STAT_BUMP(dnode_hold_free_overflow);
1592 dbuf_rele(db, FTAG);
1593 return (SET_ERROR(ENOSPC));
1594 }
1595
1596 dnode_slots_hold(dnc, idx, slots);
1597
1598 if (!dnode_check_slots_free(dnc, idx, slots)) {
1599 DNODE_STAT_BUMP(dnode_hold_free_misses);
1600 dnode_slots_rele(dnc, idx, slots);
1601 dbuf_rele(db, FTAG);
1602 return (SET_ERROR(ENOSPC));
1603 }
1604
1605 dnode_slots_rele(dnc, idx, slots);
1606 while (!dnode_slots_tryenter(dnc, idx, slots)) {
1607 DNODE_STAT_BUMP(dnode_hold_free_lock_retry);
1608 kpreempt(KPREEMPT_SYNC);
1609 }
1610
1611 if (!dnode_check_slots_free(dnc, idx, slots)) {
1612 DNODE_STAT_BUMP(dnode_hold_free_lock_misses);
1613 dnode_slots_rele(dnc, idx, slots);
1614 dbuf_rele(db, FTAG);
1615 return (SET_ERROR(ENOSPC));
1616 }
1617
1618 /*
1619 * Allocated but otherwise free dnodes which would
1620 * be in the interior of a multi-slot dnodes need
1621 * to be freed. Single slot dnodes can be safely
1622 * re-purposed as a performance optimization.
1623 */
1624 if (slots > 1)
1625 dnode_reclaim_slots(dnc, idx + 1, slots - 1);
1626
1627 dnh = &dnc->dnc_children[idx];
1628 if (DN_SLOT_IS_PTR(dnh->dnh_dnode)) {
1629 dn = dnh->dnh_dnode;
1630 } else {
1631 dn = dnode_create(os, dn_block + idx, db,
1632 object, dnh);
1633 }
1634
1635 mutex_enter(&dn->dn_mtx);
1636 if (!zfs_refcount_is_zero(&dn->dn_holds) || dn->dn_free_txg) {
1637 DNODE_STAT_BUMP(dnode_hold_free_refcount);
1638 mutex_exit(&dn->dn_mtx);
1639 dnode_slots_rele(dnc, idx, slots);
1640 dbuf_rele(db, FTAG);
1641 return (SET_ERROR(EEXIST));
1642 }
1643
1644 /* Don't actually hold if dry run, just return 0 */
1645 if (flag & DNODE_DRY_RUN) {
1646 mutex_exit(&dn->dn_mtx);
1647 dnode_slots_rele(dnc, idx, slots);
1648 dbuf_rele(db, FTAG);
1649 return (0);
1650 }
1651
1652 dnode_set_slots(dnc, idx + 1, slots - 1, DN_SLOT_INTERIOR);
1653 DNODE_STAT_BUMP(dnode_hold_free_hits);
1654 } else {
1655 dbuf_rele(db, FTAG);
1656 return (SET_ERROR(EINVAL));
1657 }
1658
1659 ASSERT0(dn->dn_free_txg);
1660
1661 if (zfs_refcount_add(&dn->dn_holds, tag) == 1)
1662 dbuf_add_ref(db, dnh);
1663
1664 mutex_exit(&dn->dn_mtx);
1665
1666 /* Now we can rely on the hold to prevent the dnode from moving. */
1667 dnode_slots_rele(dnc, idx, slots);
1668
1669 DNODE_VERIFY(dn);
1670 ASSERT3P(dnp, !=, NULL);
1671 ASSERT3P(dn->dn_dbuf, ==, db);
1672 ASSERT3U(dn->dn_object, ==, object);
1673 dbuf_rele(db, FTAG);
1674
1675 *dnp = dn;
1676 return (0);
1677 }
1678
1679 /*
1680 * Return held dnode if the object is allocated, NULL if not.
1681 */
1682 int
1683 dnode_hold(objset_t *os, uint64_t object, const void *tag, dnode_t **dnp)
1684 {
1685 return (dnode_hold_impl(os, object, DNODE_MUST_BE_ALLOCATED, 0, tag,
1686 dnp));
1687 }
1688
1689 /*
1690 * Can only add a reference if there is already at least one
1691 * reference on the dnode. Returns FALSE if unable to add a
1692 * new reference.
1693 */
1694 boolean_t
1695 dnode_add_ref(dnode_t *dn, const void *tag)
1696 {
1697 mutex_enter(&dn->dn_mtx);
1698 if (zfs_refcount_is_zero(&dn->dn_holds)) {
1699 mutex_exit(&dn->dn_mtx);
1700 return (FALSE);
1701 }
1702 VERIFY(1 < zfs_refcount_add(&dn->dn_holds, tag));
1703 mutex_exit(&dn->dn_mtx);
1704 return (TRUE);
1705 }
1706
1707 void
1708 dnode_rele(dnode_t *dn, const void *tag)
1709 {
1710 mutex_enter(&dn->dn_mtx);
1711 dnode_rele_and_unlock(dn, tag, B_FALSE);
1712 }
1713
1714 void
1715 dnode_rele_and_unlock(dnode_t *dn, const void *tag, boolean_t evicting)
1716 {
1717 uint64_t refs;
1718 /* Get while the hold prevents the dnode from moving. */
1719 dmu_buf_impl_t *db = dn->dn_dbuf;
1720 dnode_handle_t *dnh = dn->dn_handle;
1721
1722 refs = zfs_refcount_remove(&dn->dn_holds, tag);
1723 if (refs == 0)
1724 cv_broadcast(&dn->dn_nodnholds);
1725 mutex_exit(&dn->dn_mtx);
1726 /* dnode could get destroyed at this point, so don't use it anymore */
1727
1728 /*
1729 * It's unsafe to release the last hold on a dnode by dnode_rele() or
1730 * indirectly by dbuf_rele() while relying on the dnode handle to
1731 * prevent the dnode from moving, since releasing the last hold could
1732 * result in the dnode's parent dbuf evicting its dnode handles. For
1733 * that reason anyone calling dnode_rele() or dbuf_rele() without some
1734 * other direct or indirect hold on the dnode must first drop the dnode
1735 * handle.
1736 */
1737 #ifdef ZFS_DEBUG
1738 ASSERT(refs > 0 || dnh->dnh_zrlock.zr_owner != curthread);
1739 #endif
1740
1741 /* NOTE: the DNODE_DNODE does not have a dn_dbuf */
1742 if (refs == 0 && db != NULL) {
1743 /*
1744 * Another thread could add a hold to the dnode handle in
1745 * dnode_hold_impl() while holding the parent dbuf. Since the
1746 * hold on the parent dbuf prevents the handle from being
1747 * destroyed, the hold on the handle is OK. We can't yet assert
1748 * that the handle has zero references, but that will be
1749 * asserted anyway when the handle gets destroyed.
1750 */
1751 mutex_enter(&db->db_mtx);
1752 dbuf_rele_and_unlock(db, dnh, evicting);
1753 }
1754 }
1755
1756 /*
1757 * Test whether we can create a dnode at the specified location.
1758 */
1759 int
1760 dnode_try_claim(objset_t *os, uint64_t object, int slots)
1761 {
1762 return (dnode_hold_impl(os, object, DNODE_MUST_BE_FREE | DNODE_DRY_RUN,
1763 slots, NULL, NULL));
1764 }
1765
1766 /*
1767 * Checks if the dnode contains any uncommitted dirty records.
1768 */
1769 boolean_t
1770 dnode_is_dirty(dnode_t *dn)
1771 {
1772 mutex_enter(&dn->dn_mtx);
1773
1774 for (int i = 0; i < TXG_SIZE; i++) {
1775 if (multilist_link_active(&dn->dn_dirty_link[i])) {
1776 mutex_exit(&dn->dn_mtx);
1777 return (B_TRUE);
1778 }
1779 }
1780
1781 mutex_exit(&dn->dn_mtx);
1782
1783 return (B_FALSE);
1784 }
1785
1786 void
1787 dnode_setdirty(dnode_t *dn, dmu_tx_t *tx)
1788 {
1789 objset_t *os = dn->dn_objset;
1790 uint64_t txg = tx->tx_txg;
1791
1792 if (DMU_OBJECT_IS_SPECIAL(dn->dn_object)) {
1793 dsl_dataset_dirty(os->os_dsl_dataset, tx);
1794 return;
1795 }
1796
1797 DNODE_VERIFY(dn);
1798
1799 #ifdef ZFS_DEBUG
1800 mutex_enter(&dn->dn_mtx);
1801 ASSERT(dn->dn_phys->dn_type || dn->dn_allocated_txg);
1802 ASSERT(dn->dn_free_txg == 0 || dn->dn_free_txg >= txg);
1803 mutex_exit(&dn->dn_mtx);
1804 #endif
1805
1806 /*
1807 * Determine old uid/gid when necessary
1808 */
1809 dmu_objset_userquota_get_ids(dn, B_TRUE, tx);
1810
1811 multilist_t *dirtylist = &os->os_dirty_dnodes[txg & TXG_MASK];
1812 multilist_sublist_t *mls = multilist_sublist_lock_obj(dirtylist, dn);
1813
1814 /*
1815 * If we are already marked dirty, we're done.
1816 */
1817 if (multilist_link_active(&dn->dn_dirty_link[txg & TXG_MASK])) {
1818 multilist_sublist_unlock(mls);
1819 return;
1820 }
1821
1822 ASSERT(!zfs_refcount_is_zero(&dn->dn_holds) ||
1823 !avl_is_empty(&dn->dn_dbufs));
1824 ASSERT(dn->dn_datablksz != 0);
1825 ASSERT0(dn->dn_next_bonuslen[txg & TXG_MASK]);
1826 ASSERT0(dn->dn_next_blksz[txg & TXG_MASK]);
1827 ASSERT0(dn->dn_next_bonustype[txg & TXG_MASK]);
1828
1829 dprintf_ds(os->os_dsl_dataset, "obj=%llu txg=%llu\n",
1830 (u_longlong_t)dn->dn_object, (u_longlong_t)txg);
1831
1832 multilist_sublist_insert_head(mls, dn);
1833
1834 multilist_sublist_unlock(mls);
1835
1836 /*
1837 * The dnode maintains a hold on its containing dbuf as
1838 * long as there are holds on it. Each instantiated child
1839 * dbuf maintains a hold on the dnode. When the last child
1840 * drops its hold, the dnode will drop its hold on the
1841 * containing dbuf. We add a "dirty hold" here so that the
1842 * dnode will hang around after we finish processing its
1843 * children.
1844 */
1845 VERIFY(dnode_add_ref(dn, (void *)(uintptr_t)tx->tx_txg));
1846
1847 (void) dbuf_dirty(dn->dn_dbuf, tx);
1848
1849 dsl_dataset_dirty(os->os_dsl_dataset, tx);
1850 }
1851
1852 void
1853 dnode_free(dnode_t *dn, dmu_tx_t *tx)
1854 {
1855 mutex_enter(&dn->dn_mtx);
1856 if (dn->dn_type == DMU_OT_NONE || dn->dn_free_txg) {
1857 mutex_exit(&dn->dn_mtx);
1858 return;
1859 }
1860 dn->dn_free_txg = tx->tx_txg;
1861 mutex_exit(&dn->dn_mtx);
1862
1863 dnode_setdirty(dn, tx);
1864 }
1865
1866 /*
1867 * Try to change the block size for the indicated dnode. This can only
1868 * succeed if there are no blocks allocated or dirty beyond first block
1869 */
1870 int
1871 dnode_set_blksz(dnode_t *dn, uint64_t size, int ibs, dmu_tx_t *tx)
1872 {
1873 dmu_buf_impl_t *db;
1874 int err;
1875
1876 ASSERT3U(size, <=, spa_maxblocksize(dmu_objset_spa(dn->dn_objset)));
1877 if (size == 0)
1878 size = SPA_MINBLOCKSIZE;
1879 else
1880 size = P2ROUNDUP(size, SPA_MINBLOCKSIZE);
1881
1882 if (ibs == dn->dn_indblkshift)
1883 ibs = 0;
1884
1885 if (size == dn->dn_datablksz && ibs == 0)
1886 return (0);
1887
1888 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
1889
1890 /* Check for any allocated blocks beyond the first */
1891 if (dn->dn_maxblkid != 0)
1892 goto fail;
1893
1894 mutex_enter(&dn->dn_dbufs_mtx);
1895 for (db = avl_first(&dn->dn_dbufs); db != NULL;
1896 db = AVL_NEXT(&dn->dn_dbufs, db)) {
1897 if (db->db_blkid != 0 && db->db_blkid != DMU_BONUS_BLKID &&
1898 db->db_blkid != DMU_SPILL_BLKID) {
1899 mutex_exit(&dn->dn_dbufs_mtx);
1900 goto fail;
1901 }
1902 }
1903 mutex_exit(&dn->dn_dbufs_mtx);
1904
1905 if (ibs && dn->dn_nlevels != 1)
1906 goto fail;
1907
1908 dnode_setdirty(dn, tx);
1909 if (size != dn->dn_datablksz) {
1910 /* resize the old block */
1911 err = dbuf_hold_impl(dn, 0, 0, TRUE, FALSE, FTAG, &db);
1912 if (err == 0) {
1913 dbuf_new_size(db, size, tx);
1914 } else if (err != ENOENT) {
1915 goto fail;
1916 }
1917
1918 dnode_setdblksz(dn, size);
1919 dn->dn_next_blksz[tx->tx_txg & TXG_MASK] = size;
1920 if (db)
1921 dbuf_rele(db, FTAG);
1922 }
1923 if (ibs) {
1924 dn->dn_indblkshift = ibs;
1925 dn->dn_next_indblkshift[tx->tx_txg & TXG_MASK] = ibs;
1926 }
1927
1928 rw_exit(&dn->dn_struct_rwlock);
1929 return (0);
1930
1931 fail:
1932 rw_exit(&dn->dn_struct_rwlock);
1933 return (SET_ERROR(ENOTSUP));
1934 }
1935
1936 static void
1937 dnode_set_nlevels_impl(dnode_t *dn, int new_nlevels, dmu_tx_t *tx)
1938 {
1939 uint64_t txgoff = tx->tx_txg & TXG_MASK;
1940 int old_nlevels = dn->dn_nlevels;
1941 dmu_buf_impl_t *db;
1942 list_t *list;
1943 dbuf_dirty_record_t *new, *dr, *dr_next;
1944
1945 ASSERT(RW_WRITE_HELD(&dn->dn_struct_rwlock));
1946
1947 ASSERT3U(new_nlevels, >, dn->dn_nlevels);
1948 dn->dn_nlevels = new_nlevels;
1949
1950 ASSERT3U(new_nlevels, >, dn->dn_next_nlevels[txgoff]);
1951 dn->dn_next_nlevels[txgoff] = new_nlevels;
1952
1953 /* dirty the left indirects */
1954 db = dbuf_hold_level(dn, old_nlevels, 0, FTAG);
1955 ASSERT(db != NULL);
1956 new = dbuf_dirty(db, tx);
1957 dbuf_rele(db, FTAG);
1958
1959 /* transfer the dirty records to the new indirect */
1960 mutex_enter(&dn->dn_mtx);
1961 mutex_enter(&new->dt.di.dr_mtx);
1962 list = &dn->dn_dirty_records[txgoff];
1963 for (dr = list_head(list); dr; dr = dr_next) {
1964 dr_next = list_next(&dn->dn_dirty_records[txgoff], dr);
1965
1966 IMPLY(dr->dr_dbuf == NULL, old_nlevels == 1);
1967 if (dr->dr_dbuf == NULL ||
1968 (dr->dr_dbuf->db_level == old_nlevels - 1 &&
1969 dr->dr_dbuf->db_blkid != DMU_BONUS_BLKID &&
1970 dr->dr_dbuf->db_blkid != DMU_SPILL_BLKID)) {
1971 list_remove(&dn->dn_dirty_records[txgoff], dr);
1972 list_insert_tail(&new->dt.di.dr_children, dr);
1973 dr->dr_parent = new;
1974 }
1975 }
1976 mutex_exit(&new->dt.di.dr_mtx);
1977 mutex_exit(&dn->dn_mtx);
1978 }
1979
1980 int
1981 dnode_set_nlevels(dnode_t *dn, int nlevels, dmu_tx_t *tx)
1982 {
1983 int ret = 0;
1984
1985 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
1986
1987 if (dn->dn_nlevels == nlevels) {
1988 ret = 0;
1989 goto out;
1990 } else if (nlevels < dn->dn_nlevels) {
1991 ret = SET_ERROR(EINVAL);
1992 goto out;
1993 }
1994
1995 dnode_set_nlevels_impl(dn, nlevels, tx);
1996
1997 out:
1998 rw_exit(&dn->dn_struct_rwlock);
1999 return (ret);
2000 }
2001
2002 /* read-holding callers must not rely on the lock being continuously held */
2003 void
2004 dnode_new_blkid(dnode_t *dn, uint64_t blkid, dmu_tx_t *tx, boolean_t have_read,
2005 boolean_t force)
2006 {
2007 int epbs, new_nlevels;
2008 uint64_t sz;
2009
2010 ASSERT(blkid != DMU_BONUS_BLKID);
2011
2012 ASSERT(have_read ?
2013 RW_READ_HELD(&dn->dn_struct_rwlock) :
2014 RW_WRITE_HELD(&dn->dn_struct_rwlock));
2015
2016 /*
2017 * if we have a read-lock, check to see if we need to do any work
2018 * before upgrading to a write-lock.
2019 */
2020 if (have_read) {
2021 if (blkid <= dn->dn_maxblkid)
2022 return;
2023
2024 if (!rw_tryupgrade(&dn->dn_struct_rwlock)) {
2025 rw_exit(&dn->dn_struct_rwlock);
2026 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
2027 }
2028 }
2029
2030 /*
2031 * Raw sends (indicated by the force flag) require that we take the
2032 * given blkid even if the value is lower than the current value.
2033 */
2034 if (!force && blkid <= dn->dn_maxblkid)
2035 goto out;
2036
2037 /*
2038 * We use the (otherwise unused) top bit of dn_next_maxblkid[txgoff]
2039 * to indicate that this field is set. This allows us to set the
2040 * maxblkid to 0 on an existing object in dnode_sync().
2041 */
2042 dn->dn_maxblkid = blkid;
2043 dn->dn_next_maxblkid[tx->tx_txg & TXG_MASK] =
2044 blkid | DMU_NEXT_MAXBLKID_SET;
2045
2046 /*
2047 * Compute the number of levels necessary to support the new maxblkid.
2048 * Raw sends will ensure nlevels is set correctly for us.
2049 */
2050 new_nlevels = 1;
2051 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT;
2052 for (sz = dn->dn_nblkptr;
2053 sz <= blkid && sz >= dn->dn_nblkptr; sz <<= epbs)
2054 new_nlevels++;
2055
2056 ASSERT3U(new_nlevels, <=, DN_MAX_LEVELS);
2057
2058 if (!force) {
2059 if (new_nlevels > dn->dn_nlevels)
2060 dnode_set_nlevels_impl(dn, new_nlevels, tx);
2061 } else {
2062 ASSERT3U(dn->dn_nlevels, >=, new_nlevels);
2063 }
2064
2065 out:
2066 if (have_read)
2067 rw_downgrade(&dn->dn_struct_rwlock);
2068 }
2069
2070 static void
2071 dnode_dirty_l1(dnode_t *dn, uint64_t l1blkid, dmu_tx_t *tx)
2072 {
2073 dmu_buf_impl_t *db = dbuf_hold_level(dn, 1, l1blkid, FTAG);
2074 if (db != NULL) {
2075 dmu_buf_will_dirty(&db->db, tx);
2076 dbuf_rele(db, FTAG);
2077 }
2078 }
2079
2080 /*
2081 * Dirty all the in-core level-1 dbufs in the range specified by start_blkid
2082 * and end_blkid.
2083 */
2084 static void
2085 dnode_dirty_l1range(dnode_t *dn, uint64_t start_blkid, uint64_t end_blkid,
2086 dmu_tx_t *tx)
2087 {
2088 dmu_buf_impl_t *db_search;
2089 dmu_buf_impl_t *db;
2090 avl_index_t where;
2091
2092 db_search = kmem_zalloc(sizeof (dmu_buf_impl_t), KM_SLEEP);
2093
2094 mutex_enter(&dn->dn_dbufs_mtx);
2095
2096 db_search->db_level = 1;
2097 db_search->db_blkid = start_blkid + 1;
2098 db_search->db_state = DB_SEARCH;
2099 for (;;) {
2100
2101 db = avl_find(&dn->dn_dbufs, db_search, &where);
2102 if (db == NULL)
2103 db = avl_nearest(&dn->dn_dbufs, where, AVL_AFTER);
2104
2105 if (db == NULL || db->db_level != 1 ||
2106 db->db_blkid >= end_blkid) {
2107 break;
2108 }
2109
2110 /*
2111 * Setup the next blkid we want to search for.
2112 */
2113 db_search->db_blkid = db->db_blkid + 1;
2114 ASSERT3U(db->db_blkid, >=, start_blkid);
2115
2116 /*
2117 * If the dbuf transitions to DB_EVICTING while we're trying
2118 * to dirty it, then we will be unable to discover it in
2119 * the dbuf hash table. This will result in a call to
2120 * dbuf_create() which needs to acquire the dn_dbufs_mtx
2121 * lock. To avoid a deadlock, we drop the lock before
2122 * dirtying the level-1 dbuf.
2123 */
2124 mutex_exit(&dn->dn_dbufs_mtx);
2125 dnode_dirty_l1(dn, db->db_blkid, tx);
2126 mutex_enter(&dn->dn_dbufs_mtx);
2127 }
2128
2129 #ifdef ZFS_DEBUG
2130 /*
2131 * Walk all the in-core level-1 dbufs and verify they have been dirtied.
2132 */
2133 db_search->db_level = 1;
2134 db_search->db_blkid = start_blkid + 1;
2135 db_search->db_state = DB_SEARCH;
2136 db = avl_find(&dn->dn_dbufs, db_search, &where);
2137 if (db == NULL)
2138 db = avl_nearest(&dn->dn_dbufs, where, AVL_AFTER);
2139 for (; db != NULL; db = AVL_NEXT(&dn->dn_dbufs, db)) {
2140 if (db->db_level != 1 || db->db_blkid >= end_blkid)
2141 break;
2142 if (db->db_state != DB_EVICTING)
2143 ASSERT(db->db_dirtycnt > 0);
2144 }
2145 #endif
2146 kmem_free(db_search, sizeof (dmu_buf_impl_t));
2147 mutex_exit(&dn->dn_dbufs_mtx);
2148 }
2149
2150 void
2151 dnode_set_dirtyctx(dnode_t *dn, dmu_tx_t *tx, const void *tag)
2152 {
2153 /*
2154 * Don't set dirtyctx to SYNC if we're just modifying this as we
2155 * initialize the objset.
2156 */
2157 if (dn->dn_dirtyctx == DN_UNDIRTIED) {
2158 dsl_dataset_t *ds = dn->dn_objset->os_dsl_dataset;
2159
2160 if (ds != NULL) {
2161 rrw_enter(&ds->ds_bp_rwlock, RW_READER, tag);
2162 }
2163 if (!BP_IS_HOLE(dn->dn_objset->os_rootbp)) {
2164 if (dmu_tx_is_syncing(tx))
2165 dn->dn_dirtyctx = DN_DIRTY_SYNC;
2166 else
2167 dn->dn_dirtyctx = DN_DIRTY_OPEN;
2168 dn->dn_dirtyctx_firstset = tag;
2169 }
2170 if (ds != NULL) {
2171 rrw_exit(&ds->ds_bp_rwlock, tag);
2172 }
2173 }
2174 }
2175
2176 static void
2177 dnode_partial_zero(dnode_t *dn, uint64_t off, uint64_t blkoff, uint64_t len,
2178 dmu_tx_t *tx)
2179 {
2180 dmu_buf_impl_t *db;
2181 int res;
2182
2183 rw_enter(&dn->dn_struct_rwlock, RW_READER);
2184 res = dbuf_hold_impl(dn, 0, dbuf_whichblock(dn, 0, off), TRUE, FALSE,
2185 FTAG, &db);
2186 rw_exit(&dn->dn_struct_rwlock);
2187 if (res == 0) {
2188 db_lock_type_t dblt;
2189 boolean_t dirty;
2190
2191 dblt = dmu_buf_lock_parent(db, RW_READER, FTAG);
2192 /* don't dirty if not on disk and not dirty */
2193 dirty = !list_is_empty(&db->db_dirty_records) ||
2194 (db->db_blkptr && !BP_IS_HOLE(db->db_blkptr));
2195 dmu_buf_unlock_parent(db, dblt, FTAG);
2196 if (dirty) {
2197 caddr_t data;
2198
2199 dmu_buf_will_dirty(&db->db, tx);
2200 data = db->db.db_data;
2201 memset(data + blkoff, 0, len);
2202 }
2203 dbuf_rele(db, FTAG);
2204 }
2205 }
2206
2207 void
2208 dnode_free_range(dnode_t *dn, uint64_t off, uint64_t len, dmu_tx_t *tx)
2209 {
2210 uint64_t blkoff, blkid, nblks;
2211 int blksz, blkshift, head, tail;
2212 int trunc = FALSE;
2213 int epbs;
2214
2215 blksz = dn->dn_datablksz;
2216 blkshift = dn->dn_datablkshift;
2217 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT;
2218
2219 if (len == DMU_OBJECT_END) {
2220 len = UINT64_MAX - off;
2221 trunc = TRUE;
2222 }
2223
2224 /*
2225 * First, block align the region to free:
2226 */
2227 if (ISP2(blksz)) {
2228 head = P2NPHASE(off, blksz);
2229 blkoff = P2PHASE(off, blksz);
2230 if ((off >> blkshift) > dn->dn_maxblkid)
2231 return;
2232 } else {
2233 ASSERT(dn->dn_maxblkid == 0);
2234 if (off == 0 && len >= blksz) {
2235 /*
2236 * Freeing the whole block; fast-track this request.
2237 */
2238 blkid = 0;
2239 nblks = 1;
2240 if (dn->dn_nlevels > 1) {
2241 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
2242 dnode_dirty_l1(dn, 0, tx);
2243 rw_exit(&dn->dn_struct_rwlock);
2244 }
2245 goto done;
2246 } else if (off >= blksz) {
2247 /* Freeing past end-of-data */
2248 return;
2249 } else {
2250 /* Freeing part of the block. */
2251 head = blksz - off;
2252 ASSERT3U(head, >, 0);
2253 }
2254 blkoff = off;
2255 }
2256 /* zero out any partial block data at the start of the range */
2257 if (head) {
2258 ASSERT3U(blkoff + head, ==, blksz);
2259 if (len < head)
2260 head = len;
2261 dnode_partial_zero(dn, off, blkoff, head, tx);
2262 off += head;
2263 len -= head;
2264 }
2265
2266 /* If the range was less than one block, we're done */
2267 if (len == 0)
2268 return;
2269
2270 /* If the remaining range is past end of file, we're done */
2271 if ((off >> blkshift) > dn->dn_maxblkid)
2272 return;
2273
2274 ASSERT(ISP2(blksz));
2275 if (trunc)
2276 tail = 0;
2277 else
2278 tail = P2PHASE(len, blksz);
2279
2280 ASSERT0(P2PHASE(off, blksz));
2281 /* zero out any partial block data at the end of the range */
2282 if (tail) {
2283 if (len < tail)
2284 tail = len;
2285 dnode_partial_zero(dn, off + len, 0, tail, tx);
2286 len -= tail;
2287 }
2288
2289 /* If the range did not include a full block, we are done */
2290 if (len == 0)
2291 return;
2292
2293 ASSERT(IS_P2ALIGNED(off, blksz));
2294 ASSERT(trunc || IS_P2ALIGNED(len, blksz));
2295 blkid = off >> blkshift;
2296 nblks = len >> blkshift;
2297 if (trunc)
2298 nblks += 1;
2299
2300 /*
2301 * Dirty all the indirect blocks in this range. Note that only
2302 * the first and last indirect blocks can actually be written
2303 * (if they were partially freed) -- they must be dirtied, even if
2304 * they do not exist on disk yet. The interior blocks will
2305 * be freed by free_children(), so they will not actually be written.
2306 * Even though these interior blocks will not be written, we
2307 * dirty them for two reasons:
2308 *
2309 * - It ensures that the indirect blocks remain in memory until
2310 * syncing context. (They have already been prefetched by
2311 * dmu_tx_hold_free(), so we don't have to worry about reading
2312 * them serially here.)
2313 *
2314 * - The dirty space accounting will put pressure on the txg sync
2315 * mechanism to begin syncing, and to delay transactions if there
2316 * is a large amount of freeing. Even though these indirect
2317 * blocks will not be written, we could need to write the same
2318 * amount of space if we copy the freed BPs into deadlists.
2319 */
2320 if (dn->dn_nlevels > 1) {
2321 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
2322 uint64_t first, last;
2323
2324 first = blkid >> epbs;
2325 dnode_dirty_l1(dn, first, tx);
2326 if (trunc)
2327 last = dn->dn_maxblkid >> epbs;
2328 else
2329 last = (blkid + nblks - 1) >> epbs;
2330 if (last != first)
2331 dnode_dirty_l1(dn, last, tx);
2332
2333 dnode_dirty_l1range(dn, first, last, tx);
2334
2335 int shift = dn->dn_datablkshift + dn->dn_indblkshift -
2336 SPA_BLKPTRSHIFT;
2337 for (uint64_t i = first + 1; i < last; i++) {
2338 /*
2339 * Set i to the blockid of the next non-hole
2340 * level-1 indirect block at or after i. Note
2341 * that dnode_next_offset() operates in terms of
2342 * level-0-equivalent bytes.
2343 */
2344 uint64_t ibyte = i << shift;
2345 int err = dnode_next_offset(dn, DNODE_FIND_HAVELOCK,
2346 &ibyte, 2, 1, 0);
2347 i = ibyte >> shift;
2348 if (i >= last)
2349 break;
2350
2351 /*
2352 * Normally we should not see an error, either
2353 * from dnode_next_offset() or dbuf_hold_level()
2354 * (except for ESRCH from dnode_next_offset).
2355 * If there is an i/o error, then when we read
2356 * this block in syncing context, it will use
2357 * ZIO_FLAG_MUSTSUCCEED, and thus hang/panic according
2358 * to the "failmode" property. dnode_next_offset()
2359 * doesn't have a flag to indicate MUSTSUCCEED.
2360 */
2361 if (err != 0)
2362 break;
2363
2364 dnode_dirty_l1(dn, i, tx);
2365 }
2366 rw_exit(&dn->dn_struct_rwlock);
2367 }
2368
2369 done:
2370 /*
2371 * Add this range to the dnode range list.
2372 * We will finish up this free operation in the syncing phase.
2373 */
2374 mutex_enter(&dn->dn_mtx);
2375 {
2376 int txgoff = tx->tx_txg & TXG_MASK;
2377 if (dn->dn_free_ranges[txgoff] == NULL) {
2378 dn->dn_free_ranges[txgoff] = range_tree_create(NULL,
2379 RANGE_SEG64, NULL, 0, 0);
2380 }
2381 range_tree_clear(dn->dn_free_ranges[txgoff], blkid, nblks);
2382 range_tree_add(dn->dn_free_ranges[txgoff], blkid, nblks);
2383 }
2384 dprintf_dnode(dn, "blkid=%llu nblks=%llu txg=%llu\n",
2385 (u_longlong_t)blkid, (u_longlong_t)nblks,
2386 (u_longlong_t)tx->tx_txg);
2387 mutex_exit(&dn->dn_mtx);
2388
2389 dbuf_free_range(dn, blkid, blkid + nblks - 1, tx);
2390 dnode_setdirty(dn, tx);
2391 }
2392
2393 static boolean_t
2394 dnode_spill_freed(dnode_t *dn)
2395 {
2396 int i;
2397
2398 mutex_enter(&dn->dn_mtx);
2399 for (i = 0; i < TXG_SIZE; i++) {
2400 if (dn->dn_rm_spillblk[i] == DN_KILL_SPILLBLK)
2401 break;
2402 }
2403 mutex_exit(&dn->dn_mtx);
2404 return (i < TXG_SIZE);
2405 }
2406
2407 /* return TRUE if this blkid was freed in a recent txg, or FALSE if it wasn't */
2408 uint64_t
2409 dnode_block_freed(dnode_t *dn, uint64_t blkid)
2410 {
2411 int i;
2412
2413 if (blkid == DMU_BONUS_BLKID)
2414 return (FALSE);
2415
2416 if (dn->dn_free_txg)
2417 return (TRUE);
2418
2419 if (blkid == DMU_SPILL_BLKID)
2420 return (dnode_spill_freed(dn));
2421
2422 mutex_enter(&dn->dn_mtx);
2423 for (i = 0; i < TXG_SIZE; i++) {
2424 if (dn->dn_free_ranges[i] != NULL &&
2425 range_tree_contains(dn->dn_free_ranges[i], blkid, 1))
2426 break;
2427 }
2428 mutex_exit(&dn->dn_mtx);
2429 return (i < TXG_SIZE);
2430 }
2431
2432 /* call from syncing context when we actually write/free space for this dnode */
2433 void
2434 dnode_diduse_space(dnode_t *dn, int64_t delta)
2435 {
2436 uint64_t space;
2437 dprintf_dnode(dn, "dn=%p dnp=%p used=%llu delta=%lld\n",
2438 dn, dn->dn_phys,
2439 (u_longlong_t)dn->dn_phys->dn_used,
2440 (longlong_t)delta);
2441
2442 mutex_enter(&dn->dn_mtx);
2443 space = DN_USED_BYTES(dn->dn_phys);
2444 if (delta > 0) {
2445 ASSERT3U(space + delta, >=, space); /* no overflow */
2446 } else {
2447 ASSERT3U(space, >=, -delta); /* no underflow */
2448 }
2449 space += delta;
2450 if (spa_version(dn->dn_objset->os_spa) < SPA_VERSION_DNODE_BYTES) {
2451 ASSERT((dn->dn_phys->dn_flags & DNODE_FLAG_USED_BYTES) == 0);
2452 ASSERT0(P2PHASE(space, 1<<DEV_BSHIFT));
2453 dn->dn_phys->dn_used = space >> DEV_BSHIFT;
2454 } else {
2455 dn->dn_phys->dn_used = space;
2456 dn->dn_phys->dn_flags |= DNODE_FLAG_USED_BYTES;
2457 }
2458 mutex_exit(&dn->dn_mtx);
2459 }
2460
2461 /*
2462 * Scans a block at the indicated "level" looking for a hole or data,
2463 * depending on 'flags'.
2464 *
2465 * If level > 0, then we are scanning an indirect block looking at its
2466 * pointers. If level == 0, then we are looking at a block of dnodes.
2467 *
2468 * If we don't find what we are looking for in the block, we return ESRCH.
2469 * Otherwise, return with *offset pointing to the beginning (if searching
2470 * forwards) or end (if searching backwards) of the range covered by the
2471 * block pointer we matched on (or dnode).
2472 *
2473 * The basic search algorithm used below by dnode_next_offset() is to
2474 * use this function to search up the block tree (widen the search) until
2475 * we find something (i.e., we don't return ESRCH) and then search back
2476 * down the tree (narrow the search) until we reach our original search
2477 * level.
2478 */
2479 static int
2480 dnode_next_offset_level(dnode_t *dn, int flags, uint64_t *offset,
2481 int lvl, uint64_t blkfill, uint64_t txg)
2482 {
2483 dmu_buf_impl_t *db = NULL;
2484 void *data = NULL;
2485 uint64_t epbs = dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT;
2486 uint64_t epb = 1ULL << epbs;
2487 uint64_t minfill, maxfill;
2488 boolean_t hole;
2489 int i, inc, error, span;
2490
2491 ASSERT(RW_LOCK_HELD(&dn->dn_struct_rwlock));
2492
2493 hole = ((flags & DNODE_FIND_HOLE) != 0);
2494 inc = (flags & DNODE_FIND_BACKWARDS) ? -1 : 1;
2495 ASSERT(txg == 0 || !hole);
2496
2497 if (lvl == dn->dn_phys->dn_nlevels) {
2498 error = 0;
2499 epb = dn->dn_phys->dn_nblkptr;
2500 data = dn->dn_phys->dn_blkptr;
2501 } else {
2502 uint64_t blkid = dbuf_whichblock(dn, lvl, *offset);
2503 error = dbuf_hold_impl(dn, lvl, blkid, TRUE, FALSE, FTAG, &db);
2504 if (error) {
2505 if (error != ENOENT)
2506 return (error);
2507 if (hole)
2508 return (0);
2509 /*
2510 * This can only happen when we are searching up
2511 * the block tree for data. We don't really need to
2512 * adjust the offset, as we will just end up looking
2513 * at the pointer to this block in its parent, and its
2514 * going to be unallocated, so we will skip over it.
2515 */
2516 return (SET_ERROR(ESRCH));
2517 }
2518 error = dbuf_read(db, NULL,
2519 DB_RF_CANFAIL | DB_RF_HAVESTRUCT |
2520 DB_RF_NO_DECRYPT | DB_RF_NOPREFETCH);
2521 if (error) {
2522 dbuf_rele(db, FTAG);
2523 return (error);
2524 }
2525 data = db->db.db_data;
2526 rw_enter(&db->db_rwlock, RW_READER);
2527 }
2528
2529 if (db != NULL && txg != 0 && (db->db_blkptr == NULL ||
2530 db->db_blkptr->blk_birth <= txg ||
2531 BP_IS_HOLE(db->db_blkptr))) {
2532 /*
2533 * This can only happen when we are searching up the tree
2534 * and these conditions mean that we need to keep climbing.
2535 */
2536 error = SET_ERROR(ESRCH);
2537 } else if (lvl == 0) {
2538 dnode_phys_t *dnp = data;
2539
2540 ASSERT(dn->dn_type == DMU_OT_DNODE);
2541 ASSERT(!(flags & DNODE_FIND_BACKWARDS));
2542
2543 for (i = (*offset >> DNODE_SHIFT) & (blkfill - 1);
2544 i < blkfill; i += dnp[i].dn_extra_slots + 1) {
2545 if ((dnp[i].dn_type == DMU_OT_NONE) == hole)
2546 break;
2547 }
2548
2549 if (i == blkfill)
2550 error = SET_ERROR(ESRCH);
2551
2552 *offset = (*offset & ~(DNODE_BLOCK_SIZE - 1)) +
2553 (i << DNODE_SHIFT);
2554 } else {
2555 blkptr_t *bp = data;
2556 uint64_t start = *offset;
2557 span = (lvl - 1) * epbs + dn->dn_datablkshift;
2558 minfill = 0;
2559 maxfill = blkfill << ((lvl - 1) * epbs);
2560
2561 if (hole)
2562 maxfill--;
2563 else
2564 minfill++;
2565
2566 if (span >= 8 * sizeof (*offset)) {
2567 /* This only happens on the highest indirection level */
2568 ASSERT3U((lvl - 1), ==, dn->dn_phys->dn_nlevels - 1);
2569 *offset = 0;
2570 } else {
2571 *offset = *offset >> span;
2572 }
2573
2574 for (i = BF64_GET(*offset, 0, epbs);
2575 i >= 0 && i < epb; i += inc) {
2576 if (BP_GET_FILL(&bp[i]) >= minfill &&
2577 BP_GET_FILL(&bp[i]) <= maxfill &&
2578 (hole || bp[i].blk_birth > txg))
2579 break;
2580 if (inc > 0 || *offset > 0)
2581 *offset += inc;
2582 }
2583
2584 if (span >= 8 * sizeof (*offset)) {
2585 *offset = start;
2586 } else {
2587 *offset = *offset << span;
2588 }
2589
2590 if (inc < 0) {
2591 /* traversing backwards; position offset at the end */
2592 if (span < 8 * sizeof (*offset))
2593 *offset = MIN(*offset + (1ULL << span) - 1,
2594 start);
2595 } else if (*offset < start) {
2596 *offset = start;
2597 }
2598 if (i < 0 || i >= epb)
2599 error = SET_ERROR(ESRCH);
2600 }
2601
2602 if (db != NULL) {
2603 rw_exit(&db->db_rwlock);
2604 dbuf_rele(db, FTAG);
2605 }
2606
2607 return (error);
2608 }
2609
2610 /*
2611 * Find the next hole, data, or sparse region at or after *offset.
2612 * The value 'blkfill' tells us how many items we expect to find
2613 * in an L0 data block; this value is 1 for normal objects,
2614 * DNODES_PER_BLOCK for the meta dnode, and some fraction of
2615 * DNODES_PER_BLOCK when searching for sparse regions thereof.
2616 *
2617 * Examples:
2618 *
2619 * dnode_next_offset(dn, flags, offset, 1, 1, 0);
2620 * Finds the next/previous hole/data in a file.
2621 * Used in dmu_offset_next().
2622 *
2623 * dnode_next_offset(mdn, flags, offset, 0, DNODES_PER_BLOCK, txg);
2624 * Finds the next free/allocated dnode an objset's meta-dnode.
2625 * Only finds objects that have new contents since txg (ie.
2626 * bonus buffer changes and content removal are ignored).
2627 * Used in dmu_object_next().
2628 *
2629 * dnode_next_offset(mdn, DNODE_FIND_HOLE, offset, 2, DNODES_PER_BLOCK >> 2, 0);
2630 * Finds the next L2 meta-dnode bp that's at most 1/4 full.
2631 * Used in dmu_object_alloc().
2632 */
2633 int
2634 dnode_next_offset(dnode_t *dn, int flags, uint64_t *offset,
2635 int minlvl, uint64_t blkfill, uint64_t txg)
2636 {
2637 uint64_t initial_offset = *offset;
2638 int lvl, maxlvl;
2639 int error = 0;
2640
2641 if (!(flags & DNODE_FIND_HAVELOCK))
2642 rw_enter(&dn->dn_struct_rwlock, RW_READER);
2643
2644 if (dn->dn_phys->dn_nlevels == 0) {
2645 error = SET_ERROR(ESRCH);
2646 goto out;
2647 }
2648
2649 if (dn->dn_datablkshift == 0) {
2650 if (*offset < dn->dn_datablksz) {
2651 if (flags & DNODE_FIND_HOLE)
2652 *offset = dn->dn_datablksz;
2653 } else {
2654 error = SET_ERROR(ESRCH);
2655 }
2656 goto out;
2657 }
2658
2659 maxlvl = dn->dn_phys->dn_nlevels;
2660
2661 for (lvl = minlvl; lvl <= maxlvl; lvl++) {
2662 error = dnode_next_offset_level(dn,
2663 flags, offset, lvl, blkfill, txg);
2664 if (error != ESRCH)
2665 break;
2666 }
2667
2668 while (error == 0 && --lvl >= minlvl) {
2669 error = dnode_next_offset_level(dn,
2670 flags, offset, lvl, blkfill, txg);
2671 }
2672
2673 /*
2674 * There's always a "virtual hole" at the end of the object, even
2675 * if all BP's which physically exist are non-holes.
2676 */
2677 if ((flags & DNODE_FIND_HOLE) && error == ESRCH && txg == 0 &&
2678 minlvl == 1 && blkfill == 1 && !(flags & DNODE_FIND_BACKWARDS)) {
2679 error = 0;
2680 }
2681
2682 if (error == 0 && (flags & DNODE_FIND_BACKWARDS ?
2683 initial_offset < *offset : initial_offset > *offset))
2684 error = SET_ERROR(ESRCH);
2685 out:
2686 if (!(flags & DNODE_FIND_HAVELOCK))
2687 rw_exit(&dn->dn_struct_rwlock);
2688
2689 return (error);
2690 }
2691
2692 #if defined(_KERNEL)
2693 EXPORT_SYMBOL(dnode_hold);
2694 EXPORT_SYMBOL(dnode_rele);
2695 EXPORT_SYMBOL(dnode_set_nlevels);
2696 EXPORT_SYMBOL(dnode_set_blksz);
2697 EXPORT_SYMBOL(dnode_free_range);
2698 EXPORT_SYMBOL(dnode_evict_dbufs);
2699 EXPORT_SYMBOL(dnode_evict_bonus);
2700 #endif
2701
2702 ZFS_MODULE_PARAM(zfs, zfs_, default_bs, INT, ZMOD_RW,
2703 "Default dnode block shift");
2704 ZFS_MODULE_PARAM(zfs, zfs_, default_ibs, INT, ZMOD_RW,
2705 "Default dnode indirect block shift");
OpenZFS on Linux and FreeBSD