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, 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
dbuf_compare(const void * x1,const void * x2)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
dnode_cons(void * arg,void * unused,int kmflag)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 bzero(&dn->dn_next_type[0], sizeof (dn->dn_next_type));
134 bzero(&dn->dn_next_nblkptr[0], sizeof (dn->dn_next_nblkptr));
135 bzero(&dn->dn_next_nlevels[0], sizeof (dn->dn_next_nlevels));
136 bzero(&dn->dn_next_indblkshift[0], sizeof (dn->dn_next_indblkshift));
137 bzero(&dn->dn_next_bonustype[0], sizeof (dn->dn_next_bonustype));
138 bzero(&dn->dn_rm_spillblk[0], sizeof (dn->dn_rm_spillblk));
139 bzero(&dn->dn_next_bonuslen[0], sizeof (dn->dn_next_bonuslen));
140 bzero(&dn->dn_next_blksz[0], sizeof (dn->dn_next_blksz));
141 bzero(&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
dnode_dest(void * arg,void * unused)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
dnode_kstats_update(kstat_t * ksp,int rw)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
dnode_init(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
dnode_fini(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
dnode_verify(dnode_t * dn)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
dnode_byteswap(dnode_phys_t * dnp)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 bzero(dnp, 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 /*
473 * Note that the bonus length calculated here may be
474 * longer than the actual bonus buffer. This is because
475 * we always put the bonus buffer after the last block
476 * pointer (instead of packing it against the end of the
477 * dnode buffer).
478 */
479 int off = (dnp->dn_nblkptr-1) * sizeof (blkptr_t);
480 int slots = dnp->dn_extra_slots + 1;
481 size_t len = DN_SLOTS_TO_BONUSLEN(slots) - off;
482 dmu_object_byteswap_t byteswap;
483 ASSERT(DMU_OT_IS_VALID(dnp->dn_bonustype));
484 byteswap = DMU_OT_BYTESWAP(dnp->dn_bonustype);
485 dmu_ot_byteswap[byteswap].ob_func(dnp->dn_bonus + off, len);
486 }
487
488 /* Swap SPILL block if we have one */
489 if (dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR)
490 byteswap_uint64_array(DN_SPILL_BLKPTR(dnp), sizeof (blkptr_t));
491 }
492
493 void
dnode_buf_byteswap(void * vbuf,size_t size)494 dnode_buf_byteswap(void *vbuf, size_t size)
495 {
496 int i = 0;
497
498 ASSERT3U(sizeof (dnode_phys_t), ==, (1<<DNODE_SHIFT));
499 ASSERT((size & (sizeof (dnode_phys_t)-1)) == 0);
500
501 while (i < size) {
502 dnode_phys_t *dnp = (void *)(((char *)vbuf) + i);
503 dnode_byteswap(dnp);
504
505 i += DNODE_MIN_SIZE;
506 if (dnp->dn_type != DMU_OT_NONE)
507 i += dnp->dn_extra_slots * DNODE_MIN_SIZE;
508 }
509 }
510
511 void
dnode_setbonuslen(dnode_t * dn,int newsize,dmu_tx_t * tx)512 dnode_setbonuslen(dnode_t *dn, int newsize, dmu_tx_t *tx)
513 {
514 ASSERT3U(zfs_refcount_count(&dn->dn_holds), >=, 1);
515
516 dnode_setdirty(dn, tx);
517 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
518 ASSERT3U(newsize, <=, DN_SLOTS_TO_BONUSLEN(dn->dn_num_slots) -
519 (dn->dn_nblkptr-1) * sizeof (blkptr_t));
520
521 if (newsize < dn->dn_bonuslen) {
522 /* clear any data after the end of the new size */
523 size_t diff = dn->dn_bonuslen - newsize;
524 char *data_end = ((char *)dn->dn_bonus->db.db_data) + newsize;
525 bzero(data_end, diff);
526 }
527
528 dn->dn_bonuslen = newsize;
529 if (newsize == 0)
530 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = DN_ZERO_BONUSLEN;
531 else
532 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = dn->dn_bonuslen;
533 rw_exit(&dn->dn_struct_rwlock);
534 }
535
536 void
dnode_setbonus_type(dnode_t * dn,dmu_object_type_t newtype,dmu_tx_t * tx)537 dnode_setbonus_type(dnode_t *dn, dmu_object_type_t newtype, dmu_tx_t *tx)
538 {
539 ASSERT3U(zfs_refcount_count(&dn->dn_holds), >=, 1);
540 dnode_setdirty(dn, tx);
541 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
542 dn->dn_bonustype = newtype;
543 dn->dn_next_bonustype[tx->tx_txg & TXG_MASK] = dn->dn_bonustype;
544 rw_exit(&dn->dn_struct_rwlock);
545 }
546
547 void
dnode_rm_spill(dnode_t * dn,dmu_tx_t * tx)548 dnode_rm_spill(dnode_t *dn, dmu_tx_t *tx)
549 {
550 ASSERT3U(zfs_refcount_count(&dn->dn_holds), >=, 1);
551 ASSERT(RW_WRITE_HELD(&dn->dn_struct_rwlock));
552 dnode_setdirty(dn, tx);
553 dn->dn_rm_spillblk[tx->tx_txg & TXG_MASK] = DN_KILL_SPILLBLK;
554 dn->dn_have_spill = B_FALSE;
555 }
556
557 static void
dnode_setdblksz(dnode_t * dn,int size)558 dnode_setdblksz(dnode_t *dn, int size)
559 {
560 ASSERT0(P2PHASE(size, SPA_MINBLOCKSIZE));
561 ASSERT3U(size, <=, SPA_MAXBLOCKSIZE);
562 ASSERT3U(size, >=, SPA_MINBLOCKSIZE);
563 ASSERT3U(size >> SPA_MINBLOCKSHIFT, <,
564 1<<(sizeof (dn->dn_phys->dn_datablkszsec) * 8));
565 dn->dn_datablksz = size;
566 dn->dn_datablkszsec = size >> SPA_MINBLOCKSHIFT;
567 dn->dn_datablkshift = ISP2(size) ? highbit64(size - 1) : 0;
568 }
569
570 static dnode_t *
dnode_create(objset_t * os,dnode_phys_t * dnp,dmu_buf_impl_t * db,uint64_t object,dnode_handle_t * dnh)571 dnode_create(objset_t *os, dnode_phys_t *dnp, dmu_buf_impl_t *db,
572 uint64_t object, dnode_handle_t *dnh)
573 {
574 dnode_t *dn;
575
576 dn = kmem_cache_alloc(dnode_cache, KM_SLEEP);
577 dn->dn_moved = 0;
578
579 /*
580 * Defer setting dn_objset until the dnode is ready to be a candidate
581 * for the dnode_move() callback.
582 */
583 dn->dn_object = object;
584 dn->dn_dbuf = db;
585 dn->dn_handle = dnh;
586 dn->dn_phys = dnp;
587
588 if (dnp->dn_datablkszsec) {
589 dnode_setdblksz(dn, dnp->dn_datablkszsec << SPA_MINBLOCKSHIFT);
590 } else {
591 dn->dn_datablksz = 0;
592 dn->dn_datablkszsec = 0;
593 dn->dn_datablkshift = 0;
594 }
595 dn->dn_indblkshift = dnp->dn_indblkshift;
596 dn->dn_nlevels = dnp->dn_nlevels;
597 dn->dn_type = dnp->dn_type;
598 dn->dn_nblkptr = dnp->dn_nblkptr;
599 dn->dn_checksum = dnp->dn_checksum;
600 dn->dn_compress = dnp->dn_compress;
601 dn->dn_bonustype = dnp->dn_bonustype;
602 dn->dn_bonuslen = dnp->dn_bonuslen;
603 dn->dn_num_slots = dnp->dn_extra_slots + 1;
604 dn->dn_maxblkid = dnp->dn_maxblkid;
605 dn->dn_have_spill = ((dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) != 0);
606 dn->dn_id_flags = 0;
607
608 dmu_zfetch_init(&dn->dn_zfetch, dn);
609
610 ASSERT(DMU_OT_IS_VALID(dn->dn_phys->dn_type));
611 ASSERT(zrl_is_locked(&dnh->dnh_zrlock));
612 ASSERT(!DN_SLOT_IS_PTR(dnh->dnh_dnode));
613
614 mutex_enter(&os->os_lock);
615
616 /*
617 * Exclude special dnodes from os_dnodes so an empty os_dnodes
618 * signifies that the special dnodes have no references from
619 * their children (the entries in os_dnodes). This allows
620 * dnode_destroy() to easily determine if the last child has
621 * been removed and then complete eviction of the objset.
622 */
623 if (!DMU_OBJECT_IS_SPECIAL(object))
624 list_insert_head(&os->os_dnodes, dn);
625 membar_producer();
626
627 /*
628 * Everything else must be valid before assigning dn_objset
629 * makes the dnode eligible for dnode_move().
630 */
631 dn->dn_objset = os;
632
633 dnh->dnh_dnode = dn;
634 mutex_exit(&os->os_lock);
635
636 arc_space_consume(sizeof (dnode_t), ARC_SPACE_DNODE);
637
638 return (dn);
639 }
640
641 /*
642 * Caller must be holding the dnode handle, which is released upon return.
643 */
644 static void
dnode_destroy(dnode_t * dn)645 dnode_destroy(dnode_t *dn)
646 {
647 objset_t *os = dn->dn_objset;
648 boolean_t complete_os_eviction = B_FALSE;
649
650 ASSERT((dn->dn_id_flags & DN_ID_NEW_EXIST) == 0);
651
652 mutex_enter(&os->os_lock);
653 POINTER_INVALIDATE(&dn->dn_objset);
654 if (!DMU_OBJECT_IS_SPECIAL(dn->dn_object)) {
655 list_remove(&os->os_dnodes, dn);
656 complete_os_eviction =
657 list_is_empty(&os->os_dnodes) &&
658 list_link_active(&os->os_evicting_node);
659 }
660 mutex_exit(&os->os_lock);
661
662 /* the dnode can no longer move, so we can release the handle */
663 if (!zrl_is_locked(&dn->dn_handle->dnh_zrlock))
664 zrl_remove(&dn->dn_handle->dnh_zrlock);
665
666 dn->dn_allocated_txg = 0;
667 dn->dn_free_txg = 0;
668 dn->dn_assigned_txg = 0;
669 dn->dn_dirty_txg = 0;
670
671 dn->dn_dirtyctx = 0;
672 dn->dn_dirtyctx_firstset = NULL;
673 if (dn->dn_bonus != NULL) {
674 mutex_enter(&dn->dn_bonus->db_mtx);
675 dbuf_destroy(dn->dn_bonus);
676 dn->dn_bonus = NULL;
677 }
678 dn->dn_zio = NULL;
679
680 dn->dn_have_spill = B_FALSE;
681 dn->dn_oldused = 0;
682 dn->dn_oldflags = 0;
683 dn->dn_olduid = 0;
684 dn->dn_oldgid = 0;
685 dn->dn_oldprojid = ZFS_DEFAULT_PROJID;
686 dn->dn_newuid = 0;
687 dn->dn_newgid = 0;
688 dn->dn_newprojid = ZFS_DEFAULT_PROJID;
689 dn->dn_id_flags = 0;
690
691 dmu_zfetch_fini(&dn->dn_zfetch);
692 kmem_cache_free(dnode_cache, dn);
693 arc_space_return(sizeof (dnode_t), ARC_SPACE_DNODE);
694
695 if (complete_os_eviction)
696 dmu_objset_evict_done(os);
697 }
698
699 void
dnode_allocate(dnode_t * dn,dmu_object_type_t ot,int blocksize,int ibs,dmu_object_type_t bonustype,int bonuslen,int dn_slots,dmu_tx_t * tx)700 dnode_allocate(dnode_t *dn, dmu_object_type_t ot, int blocksize, int ibs,
701 dmu_object_type_t bonustype, int bonuslen, int dn_slots, dmu_tx_t *tx)
702 {
703 int i;
704
705 ASSERT3U(dn_slots, >, 0);
706 ASSERT3U(dn_slots << DNODE_SHIFT, <=,
707 spa_maxdnodesize(dmu_objset_spa(dn->dn_objset)));
708 ASSERT3U(blocksize, <=,
709 spa_maxblocksize(dmu_objset_spa(dn->dn_objset)));
710 if (blocksize == 0)
711 blocksize = 1 << zfs_default_bs;
712 else
713 blocksize = P2ROUNDUP(blocksize, SPA_MINBLOCKSIZE);
714
715 if (ibs == 0)
716 ibs = zfs_default_ibs;
717
718 ibs = MIN(MAX(ibs, DN_MIN_INDBLKSHIFT), DN_MAX_INDBLKSHIFT);
719
720 dprintf("os=%p obj=%llu txg=%llu blocksize=%d ibs=%d dn_slots=%d\n",
721 dn->dn_objset, (u_longlong_t)dn->dn_object,
722 (u_longlong_t)tx->tx_txg, blocksize, ibs, dn_slots);
723 DNODE_STAT_BUMP(dnode_allocate);
724
725 ASSERT(dn->dn_type == DMU_OT_NONE);
726 ASSERT(bcmp(dn->dn_phys, &dnode_phys_zero, sizeof (dnode_phys_t)) == 0);
727 ASSERT(dn->dn_phys->dn_type == DMU_OT_NONE);
728 ASSERT(ot != DMU_OT_NONE);
729 ASSERT(DMU_OT_IS_VALID(ot));
730 ASSERT((bonustype == DMU_OT_NONE && bonuslen == 0) ||
731 (bonustype == DMU_OT_SA && bonuslen == 0) ||
732 (bonustype != DMU_OT_NONE && bonuslen != 0));
733 ASSERT(DMU_OT_IS_VALID(bonustype));
734 ASSERT3U(bonuslen, <=, DN_SLOTS_TO_BONUSLEN(dn_slots));
735 ASSERT(dn->dn_type == DMU_OT_NONE);
736 ASSERT0(dn->dn_maxblkid);
737 ASSERT0(dn->dn_allocated_txg);
738 ASSERT0(dn->dn_assigned_txg);
739 ASSERT(zfs_refcount_is_zero(&dn->dn_tx_holds));
740 ASSERT3U(zfs_refcount_count(&dn->dn_holds), <=, 1);
741 ASSERT(avl_is_empty(&dn->dn_dbufs));
742
743 for (i = 0; i < TXG_SIZE; i++) {
744 ASSERT0(dn->dn_next_nblkptr[i]);
745 ASSERT0(dn->dn_next_nlevels[i]);
746 ASSERT0(dn->dn_next_indblkshift[i]);
747 ASSERT0(dn->dn_next_bonuslen[i]);
748 ASSERT0(dn->dn_next_bonustype[i]);
749 ASSERT0(dn->dn_rm_spillblk[i]);
750 ASSERT0(dn->dn_next_blksz[i]);
751 ASSERT0(dn->dn_next_maxblkid[i]);
752 ASSERT(!multilist_link_active(&dn->dn_dirty_link[i]));
753 ASSERT3P(list_head(&dn->dn_dirty_records[i]), ==, NULL);
754 ASSERT3P(dn->dn_free_ranges[i], ==, NULL);
755 }
756
757 dn->dn_type = ot;
758 dnode_setdblksz(dn, blocksize);
759 dn->dn_indblkshift = ibs;
760 dn->dn_nlevels = 1;
761 dn->dn_num_slots = dn_slots;
762 if (bonustype == DMU_OT_SA) /* Maximize bonus space for SA */
763 dn->dn_nblkptr = 1;
764 else {
765 dn->dn_nblkptr = MIN(DN_MAX_NBLKPTR,
766 1 + ((DN_SLOTS_TO_BONUSLEN(dn_slots) - bonuslen) >>
767 SPA_BLKPTRSHIFT));
768 }
769
770 dn->dn_bonustype = bonustype;
771 dn->dn_bonuslen = bonuslen;
772 dn->dn_checksum = ZIO_CHECKSUM_INHERIT;
773 dn->dn_compress = ZIO_COMPRESS_INHERIT;
774 dn->dn_dirtyctx = 0;
775
776 dn->dn_free_txg = 0;
777 dn->dn_dirtyctx_firstset = NULL;
778 dn->dn_dirty_txg = 0;
779
780 dn->dn_allocated_txg = tx->tx_txg;
781 dn->dn_id_flags = 0;
782
783 dnode_setdirty(dn, tx);
784 dn->dn_next_indblkshift[tx->tx_txg & TXG_MASK] = ibs;
785 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = dn->dn_bonuslen;
786 dn->dn_next_bonustype[tx->tx_txg & TXG_MASK] = dn->dn_bonustype;
787 dn->dn_next_blksz[tx->tx_txg & TXG_MASK] = dn->dn_datablksz;
788 }
789
790 void
dnode_reallocate(dnode_t * dn,dmu_object_type_t ot,int blocksize,dmu_object_type_t bonustype,int bonuslen,int dn_slots,boolean_t keep_spill,dmu_tx_t * tx)791 dnode_reallocate(dnode_t *dn, dmu_object_type_t ot, int blocksize,
792 dmu_object_type_t bonustype, int bonuslen, int dn_slots,
793 boolean_t keep_spill, dmu_tx_t *tx)
794 {
795 int nblkptr;
796
797 ASSERT3U(blocksize, >=, SPA_MINBLOCKSIZE);
798 ASSERT3U(blocksize, <=,
799 spa_maxblocksize(dmu_objset_spa(dn->dn_objset)));
800 ASSERT0(blocksize % SPA_MINBLOCKSIZE);
801 ASSERT(dn->dn_object != DMU_META_DNODE_OBJECT || dmu_tx_private_ok(tx));
802 ASSERT(tx->tx_txg != 0);
803 ASSERT((bonustype == DMU_OT_NONE && bonuslen == 0) ||
804 (bonustype != DMU_OT_NONE && bonuslen != 0) ||
805 (bonustype == DMU_OT_SA && bonuslen == 0));
806 ASSERT(DMU_OT_IS_VALID(bonustype));
807 ASSERT3U(bonuslen, <=,
808 DN_BONUS_SIZE(spa_maxdnodesize(dmu_objset_spa(dn->dn_objset))));
809 ASSERT3U(bonuslen, <=, DN_BONUS_SIZE(dn_slots << DNODE_SHIFT));
810
811 dnode_free_interior_slots(dn);
812 DNODE_STAT_BUMP(dnode_reallocate);
813
814 /* clean up any unreferenced dbufs */
815 dnode_evict_dbufs(dn);
816
817 dn->dn_id_flags = 0;
818
819 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
820 dnode_setdirty(dn, tx);
821 if (dn->dn_datablksz != blocksize) {
822 /* change blocksize */
823 ASSERT0(dn->dn_maxblkid);
824 ASSERT(BP_IS_HOLE(&dn->dn_phys->dn_blkptr[0]) ||
825 dnode_block_freed(dn, 0));
826
827 dnode_setdblksz(dn, blocksize);
828 dn->dn_next_blksz[tx->tx_txg & TXG_MASK] = blocksize;
829 }
830 if (dn->dn_bonuslen != bonuslen)
831 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = bonuslen;
832
833 if (bonustype == DMU_OT_SA) /* Maximize bonus space for SA */
834 nblkptr = 1;
835 else
836 nblkptr = MIN(DN_MAX_NBLKPTR,
837 1 + ((DN_SLOTS_TO_BONUSLEN(dn_slots) - bonuslen) >>
838 SPA_BLKPTRSHIFT));
839 if (dn->dn_bonustype != bonustype)
840 dn->dn_next_bonustype[tx->tx_txg & TXG_MASK] = bonustype;
841 if (dn->dn_nblkptr != nblkptr)
842 dn->dn_next_nblkptr[tx->tx_txg & TXG_MASK] = nblkptr;
843 if (dn->dn_phys->dn_flags & DNODE_FLAG_SPILL_BLKPTR && !keep_spill) {
844 dbuf_rm_spill(dn, tx);
845 dnode_rm_spill(dn, tx);
846 }
847
848 rw_exit(&dn->dn_struct_rwlock);
849
850 /* change type */
851 dn->dn_type = ot;
852
853 /* change bonus size and type */
854 mutex_enter(&dn->dn_mtx);
855 dn->dn_bonustype = bonustype;
856 dn->dn_bonuslen = bonuslen;
857 dn->dn_num_slots = dn_slots;
858 dn->dn_nblkptr = nblkptr;
859 dn->dn_checksum = ZIO_CHECKSUM_INHERIT;
860 dn->dn_compress = ZIO_COMPRESS_INHERIT;
861 ASSERT3U(dn->dn_nblkptr, <=, DN_MAX_NBLKPTR);
862
863 /* fix up the bonus db_size */
864 if (dn->dn_bonus) {
865 dn->dn_bonus->db.db_size =
866 DN_SLOTS_TO_BONUSLEN(dn->dn_num_slots) -
867 (dn->dn_nblkptr-1) * sizeof (blkptr_t);
868 ASSERT(dn->dn_bonuslen <= dn->dn_bonus->db.db_size);
869 }
870
871 dn->dn_allocated_txg = tx->tx_txg;
872 mutex_exit(&dn->dn_mtx);
873 }
874
875 #ifdef _KERNEL
876 static void
dnode_move_impl(dnode_t * odn,dnode_t * ndn)877 dnode_move_impl(dnode_t *odn, dnode_t *ndn)
878 {
879 int i;
880
881 ASSERT(!RW_LOCK_HELD(&odn->dn_struct_rwlock));
882 ASSERT(MUTEX_NOT_HELD(&odn->dn_mtx));
883 ASSERT(MUTEX_NOT_HELD(&odn->dn_dbufs_mtx));
884
885 /* Copy fields. */
886 ndn->dn_objset = odn->dn_objset;
887 ndn->dn_object = odn->dn_object;
888 ndn->dn_dbuf = odn->dn_dbuf;
889 ndn->dn_handle = odn->dn_handle;
890 ndn->dn_phys = odn->dn_phys;
891 ndn->dn_type = odn->dn_type;
892 ndn->dn_bonuslen = odn->dn_bonuslen;
893 ndn->dn_bonustype = odn->dn_bonustype;
894 ndn->dn_nblkptr = odn->dn_nblkptr;
895 ndn->dn_checksum = odn->dn_checksum;
896 ndn->dn_compress = odn->dn_compress;
897 ndn->dn_nlevels = odn->dn_nlevels;
898 ndn->dn_indblkshift = odn->dn_indblkshift;
899 ndn->dn_datablkshift = odn->dn_datablkshift;
900 ndn->dn_datablkszsec = odn->dn_datablkszsec;
901 ndn->dn_datablksz = odn->dn_datablksz;
902 ndn->dn_maxblkid = odn->dn_maxblkid;
903 ndn->dn_num_slots = odn->dn_num_slots;
904 bcopy(&odn->dn_next_type[0], &ndn->dn_next_type[0],
905 sizeof (odn->dn_next_type));
906 bcopy(&odn->dn_next_nblkptr[0], &ndn->dn_next_nblkptr[0],
907 sizeof (odn->dn_next_nblkptr));
908 bcopy(&odn->dn_next_nlevels[0], &ndn->dn_next_nlevels[0],
909 sizeof (odn->dn_next_nlevels));
910 bcopy(&odn->dn_next_indblkshift[0], &ndn->dn_next_indblkshift[0],
911 sizeof (odn->dn_next_indblkshift));
912 bcopy(&odn->dn_next_bonustype[0], &ndn->dn_next_bonustype[0],
913 sizeof (odn->dn_next_bonustype));
914 bcopy(&odn->dn_rm_spillblk[0], &ndn->dn_rm_spillblk[0],
915 sizeof (odn->dn_rm_spillblk));
916 bcopy(&odn->dn_next_bonuslen[0], &ndn->dn_next_bonuslen[0],
917 sizeof (odn->dn_next_bonuslen));
918 bcopy(&odn->dn_next_blksz[0], &ndn->dn_next_blksz[0],
919 sizeof (odn->dn_next_blksz));
920 bcopy(&odn->dn_next_maxblkid[0], &ndn->dn_next_maxblkid[0],
921 sizeof (odn->dn_next_maxblkid));
922 for (i = 0; i < TXG_SIZE; i++) {
923 list_move_tail(&ndn->dn_dirty_records[i],
924 &odn->dn_dirty_records[i]);
925 }
926 bcopy(&odn->dn_free_ranges[0], &ndn->dn_free_ranges[0],
927 sizeof (odn->dn_free_ranges));
928 ndn->dn_allocated_txg = odn->dn_allocated_txg;
929 ndn->dn_free_txg = odn->dn_free_txg;
930 ndn->dn_assigned_txg = odn->dn_assigned_txg;
931 ndn->dn_dirty_txg = odn->dn_dirty_txg;
932 ndn->dn_dirtyctx = odn->dn_dirtyctx;
933 ndn->dn_dirtyctx_firstset = odn->dn_dirtyctx_firstset;
934 ASSERT(zfs_refcount_count(&odn->dn_tx_holds) == 0);
935 zfs_refcount_transfer(&ndn->dn_holds, &odn->dn_holds);
936 ASSERT(avl_is_empty(&ndn->dn_dbufs));
937 avl_swap(&ndn->dn_dbufs, &odn->dn_dbufs);
938 ndn->dn_dbufs_count = odn->dn_dbufs_count;
939 ndn->dn_bonus = odn->dn_bonus;
940 ndn->dn_have_spill = odn->dn_have_spill;
941 ndn->dn_zio = odn->dn_zio;
942 ndn->dn_oldused = odn->dn_oldused;
943 ndn->dn_oldflags = odn->dn_oldflags;
944 ndn->dn_olduid = odn->dn_olduid;
945 ndn->dn_oldgid = odn->dn_oldgid;
946 ndn->dn_oldprojid = odn->dn_oldprojid;
947 ndn->dn_newuid = odn->dn_newuid;
948 ndn->dn_newgid = odn->dn_newgid;
949 ndn->dn_newprojid = odn->dn_newprojid;
950 ndn->dn_id_flags = odn->dn_id_flags;
951 dmu_zfetch_init(&ndn->dn_zfetch, ndn);
952
953 /*
954 * Update back pointers. Updating the handle fixes the back pointer of
955 * every descendant dbuf as well as the bonus dbuf.
956 */
957 ASSERT(ndn->dn_handle->dnh_dnode == odn);
958 ndn->dn_handle->dnh_dnode = ndn;
959
960 /*
961 * Invalidate the original dnode by clearing all of its back pointers.
962 */
963 odn->dn_dbuf = NULL;
964 odn->dn_handle = NULL;
965 avl_create(&odn->dn_dbufs, dbuf_compare, sizeof (dmu_buf_impl_t),
966 offsetof(dmu_buf_impl_t, db_link));
967 odn->dn_dbufs_count = 0;
968 odn->dn_bonus = NULL;
969 dmu_zfetch_fini(&odn->dn_zfetch);
970
971 /*
972 * Set the low bit of the objset pointer to ensure that dnode_move()
973 * recognizes the dnode as invalid in any subsequent callback.
974 */
975 POINTER_INVALIDATE(&odn->dn_objset);
976
977 /*
978 * Satisfy the destructor.
979 */
980 for (i = 0; i < TXG_SIZE; i++) {
981 list_create(&odn->dn_dirty_records[i],
982 sizeof (dbuf_dirty_record_t),
983 offsetof(dbuf_dirty_record_t, dr_dirty_node));
984 odn->dn_free_ranges[i] = NULL;
985 odn->dn_next_nlevels[i] = 0;
986 odn->dn_next_indblkshift[i] = 0;
987 odn->dn_next_bonustype[i] = 0;
988 odn->dn_rm_spillblk[i] = 0;
989 odn->dn_next_bonuslen[i] = 0;
990 odn->dn_next_blksz[i] = 0;
991 }
992 odn->dn_allocated_txg = 0;
993 odn->dn_free_txg = 0;
994 odn->dn_assigned_txg = 0;
995 odn->dn_dirty_txg = 0;
996 odn->dn_dirtyctx = 0;
997 odn->dn_dirtyctx_firstset = NULL;
998 odn->dn_have_spill = B_FALSE;
999 odn->dn_zio = NULL;
1000 odn->dn_oldused = 0;
1001 odn->dn_oldflags = 0;
1002 odn->dn_olduid = 0;
1003 odn->dn_oldgid = 0;
1004 odn->dn_oldprojid = ZFS_DEFAULT_PROJID;
1005 odn->dn_newuid = 0;
1006 odn->dn_newgid = 0;
1007 odn->dn_newprojid = ZFS_DEFAULT_PROJID;
1008 odn->dn_id_flags = 0;
1009
1010 /*
1011 * Mark the dnode.
1012 */
1013 ndn->dn_moved = 1;
1014 odn->dn_moved = (uint8_t)-1;
1015 }
1016
1017 static kmem_cbrc_t
dnode_move(void * buf,void * newbuf,size_t size,void * arg)1018 dnode_move(void *buf, void *newbuf, size_t size, void *arg)
1019 {
1020 dnode_t *odn = buf, *ndn = newbuf;
1021 objset_t *os;
1022 int64_t refcount;
1023 uint32_t dbufs;
1024
1025 /*
1026 * The dnode is on the objset's list of known dnodes if the objset
1027 * pointer is valid. We set the low bit of the objset pointer when
1028 * freeing the dnode to invalidate it, and the memory patterns written
1029 * by kmem (baddcafe and deadbeef) set at least one of the two low bits.
1030 * A newly created dnode sets the objset pointer last of all to indicate
1031 * that the dnode is known and in a valid state to be moved by this
1032 * function.
1033 */
1034 os = odn->dn_objset;
1035 if (!POINTER_IS_VALID(os)) {
1036 DNODE_STAT_BUMP(dnode_move_invalid);
1037 return (KMEM_CBRC_DONT_KNOW);
1038 }
1039
1040 /*
1041 * Ensure that the objset does not go away during the move.
1042 */
1043 rw_enter(&os_lock, RW_WRITER);
1044 if (os != odn->dn_objset) {
1045 rw_exit(&os_lock);
1046 DNODE_STAT_BUMP(dnode_move_recheck1);
1047 return (KMEM_CBRC_DONT_KNOW);
1048 }
1049
1050 /*
1051 * If the dnode is still valid, then so is the objset. We know that no
1052 * valid objset can be freed while we hold os_lock, so we can safely
1053 * ensure that the objset remains in use.
1054 */
1055 mutex_enter(&os->os_lock);
1056
1057 /*
1058 * Recheck the objset pointer in case the dnode was removed just before
1059 * acquiring the lock.
1060 */
1061 if (os != odn->dn_objset) {
1062 mutex_exit(&os->os_lock);
1063 rw_exit(&os_lock);
1064 DNODE_STAT_BUMP(dnode_move_recheck2);
1065 return (KMEM_CBRC_DONT_KNOW);
1066 }
1067
1068 /*
1069 * At this point we know that as long as we hold os->os_lock, the dnode
1070 * cannot be freed and fields within the dnode can be safely accessed.
1071 * The objset listing this dnode cannot go away as long as this dnode is
1072 * on its list.
1073 */
1074 rw_exit(&os_lock);
1075 if (DMU_OBJECT_IS_SPECIAL(odn->dn_object)) {
1076 mutex_exit(&os->os_lock);
1077 DNODE_STAT_BUMP(dnode_move_special);
1078 return (KMEM_CBRC_NO);
1079 }
1080 ASSERT(odn->dn_dbuf != NULL); /* only "special" dnodes have no parent */
1081
1082 /*
1083 * Lock the dnode handle to prevent the dnode from obtaining any new
1084 * holds. This also prevents the descendant dbufs and the bonus dbuf
1085 * from accessing the dnode, so that we can discount their holds. The
1086 * handle is safe to access because we know that while the dnode cannot
1087 * go away, neither can its handle. Once we hold dnh_zrlock, we can
1088 * safely move any dnode referenced only by dbufs.
1089 */
1090 if (!zrl_tryenter(&odn->dn_handle->dnh_zrlock)) {
1091 mutex_exit(&os->os_lock);
1092 DNODE_STAT_BUMP(dnode_move_handle);
1093 return (KMEM_CBRC_LATER);
1094 }
1095
1096 /*
1097 * Ensure a consistent view of the dnode's holds and the dnode's dbufs.
1098 * We need to guarantee that there is a hold for every dbuf in order to
1099 * determine whether the dnode is actively referenced. Falsely matching
1100 * a dbuf to an active hold would lead to an unsafe move. It's possible
1101 * that a thread already having an active dnode hold is about to add a
1102 * dbuf, and we can't compare hold and dbuf counts while the add is in
1103 * progress.
1104 */
1105 if (!rw_tryenter(&odn->dn_struct_rwlock, RW_WRITER)) {
1106 zrl_exit(&odn->dn_handle->dnh_zrlock);
1107 mutex_exit(&os->os_lock);
1108 DNODE_STAT_BUMP(dnode_move_rwlock);
1109 return (KMEM_CBRC_LATER);
1110 }
1111
1112 /*
1113 * A dbuf may be removed (evicted) without an active dnode hold. In that
1114 * case, the dbuf count is decremented under the handle lock before the
1115 * dbuf's hold is released. This order ensures that if we count the hold
1116 * after the dbuf is removed but before its hold is released, we will
1117 * treat the unmatched hold as active and exit safely. If we count the
1118 * hold before the dbuf is removed, the hold is discounted, and the
1119 * removal is blocked until the move completes.
1120 */
1121 refcount = zfs_refcount_count(&odn->dn_holds);
1122 ASSERT(refcount >= 0);
1123 dbufs = DN_DBUFS_COUNT(odn);
1124
1125 /* We can't have more dbufs than dnode holds. */
1126 ASSERT3U(dbufs, <=, refcount);
1127 DTRACE_PROBE3(dnode__move, dnode_t *, odn, int64_t, refcount,
1128 uint32_t, dbufs);
1129
1130 if (refcount > dbufs) {
1131 rw_exit(&odn->dn_struct_rwlock);
1132 zrl_exit(&odn->dn_handle->dnh_zrlock);
1133 mutex_exit(&os->os_lock);
1134 DNODE_STAT_BUMP(dnode_move_active);
1135 return (KMEM_CBRC_LATER);
1136 }
1137
1138 rw_exit(&odn->dn_struct_rwlock);
1139
1140 /*
1141 * At this point we know that anyone with a hold on the dnode is not
1142 * actively referencing it. The dnode is known and in a valid state to
1143 * move. We're holding the locks needed to execute the critical section.
1144 */
1145 dnode_move_impl(odn, ndn);
1146
1147 list_link_replace(&odn->dn_link, &ndn->dn_link);
1148 /* If the dnode was safe to move, the refcount cannot have changed. */
1149 ASSERT(refcount == zfs_refcount_count(&ndn->dn_holds));
1150 ASSERT(dbufs == DN_DBUFS_COUNT(ndn));
1151 zrl_exit(&ndn->dn_handle->dnh_zrlock); /* handle has moved */
1152 mutex_exit(&os->os_lock);
1153
1154 return (KMEM_CBRC_YES);
1155 }
1156 #endif /* _KERNEL */
1157
1158 static void
dnode_slots_hold(dnode_children_t * children,int idx,int slots)1159 dnode_slots_hold(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 zrl_add(&dnh->dnh_zrlock);
1166 }
1167 }
1168
1169 static void
dnode_slots_rele(dnode_children_t * children,int idx,int slots)1170 dnode_slots_rele(dnode_children_t *children, int idx, int slots)
1171 {
1172 ASSERT3S(idx + slots, <=, DNODES_PER_BLOCK);
1173
1174 for (int i = idx; i < idx + slots; i++) {
1175 dnode_handle_t *dnh = &children->dnc_children[i];
1176
1177 if (zrl_is_locked(&dnh->dnh_zrlock))
1178 zrl_exit(&dnh->dnh_zrlock);
1179 else
1180 zrl_remove(&dnh->dnh_zrlock);
1181 }
1182 }
1183
1184 static int
dnode_slots_tryenter(dnode_children_t * children,int idx,int slots)1185 dnode_slots_tryenter(dnode_children_t *children, int idx, int slots)
1186 {
1187 ASSERT3S(idx + slots, <=, DNODES_PER_BLOCK);
1188
1189 for (int i = idx; i < idx + slots; i++) {
1190 dnode_handle_t *dnh = &children->dnc_children[i];
1191
1192 if (!zrl_tryenter(&dnh->dnh_zrlock)) {
1193 for (int j = idx; j < i; j++) {
1194 dnh = &children->dnc_children[j];
1195 zrl_exit(&dnh->dnh_zrlock);
1196 }
1197
1198 return (0);
1199 }
1200 }
1201
1202 return (1);
1203 }
1204
1205 static void
dnode_set_slots(dnode_children_t * children,int idx,int slots,void * ptr)1206 dnode_set_slots(dnode_children_t *children, int idx, int slots, void *ptr)
1207 {
1208 ASSERT3S(idx + slots, <=, DNODES_PER_BLOCK);
1209
1210 for (int i = idx; i < idx + slots; i++) {
1211 dnode_handle_t *dnh = &children->dnc_children[i];
1212 dnh->dnh_dnode = ptr;
1213 }
1214 }
1215
1216 static boolean_t
dnode_check_slots_free(dnode_children_t * children,int idx,int slots)1217 dnode_check_slots_free(dnode_children_t *children, int idx, int slots)
1218 {
1219 ASSERT3S(idx + slots, <=, DNODES_PER_BLOCK);
1220
1221 /*
1222 * If all dnode slots are either already free or
1223 * evictable return B_TRUE.
1224 */
1225 for (int i = idx; i < idx + slots; i++) {
1226 dnode_handle_t *dnh = &children->dnc_children[i];
1227 dnode_t *dn = dnh->dnh_dnode;
1228
1229 if (dn == DN_SLOT_FREE) {
1230 continue;
1231 } else if (DN_SLOT_IS_PTR(dn)) {
1232 mutex_enter(&dn->dn_mtx);
1233 boolean_t can_free = (dn->dn_type == DMU_OT_NONE &&
1234 zfs_refcount_is_zero(&dn->dn_holds) &&
1235 !DNODE_IS_DIRTY(dn));
1236 mutex_exit(&dn->dn_mtx);
1237
1238 if (!can_free)
1239 return (B_FALSE);
1240 else
1241 continue;
1242 } else {
1243 return (B_FALSE);
1244 }
1245 }
1246
1247 return (B_TRUE);
1248 }
1249
1250 static void
dnode_reclaim_slots(dnode_children_t * children,int idx,int slots)1251 dnode_reclaim_slots(dnode_children_t *children, int idx, int slots)
1252 {
1253 ASSERT3S(idx + slots, <=, DNODES_PER_BLOCK);
1254
1255 for (int i = idx; i < idx + slots; i++) {
1256 dnode_handle_t *dnh = &children->dnc_children[i];
1257
1258 ASSERT(zrl_is_locked(&dnh->dnh_zrlock));
1259
1260 if (DN_SLOT_IS_PTR(dnh->dnh_dnode)) {
1261 ASSERT3S(dnh->dnh_dnode->dn_type, ==, DMU_OT_NONE);
1262 dnode_destroy(dnh->dnh_dnode);
1263 dnh->dnh_dnode = DN_SLOT_FREE;
1264 }
1265 }
1266 }
1267
1268 void
dnode_free_interior_slots(dnode_t * dn)1269 dnode_free_interior_slots(dnode_t *dn)
1270 {
1271 dnode_children_t *children = dmu_buf_get_user(&dn->dn_dbuf->db);
1272 int epb = dn->dn_dbuf->db.db_size >> DNODE_SHIFT;
1273 int idx = (dn->dn_object & (epb - 1)) + 1;
1274 int slots = dn->dn_num_slots - 1;
1275
1276 if (slots == 0)
1277 return;
1278
1279 ASSERT3S(idx + slots, <=, DNODES_PER_BLOCK);
1280
1281 while (!dnode_slots_tryenter(children, idx, slots)) {
1282 DNODE_STAT_BUMP(dnode_free_interior_lock_retry);
1283 cond_resched();
1284 }
1285
1286 dnode_set_slots(children, idx, slots, DN_SLOT_FREE);
1287 dnode_slots_rele(children, idx, slots);
1288 }
1289
1290 void
dnode_special_close(dnode_handle_t * dnh)1291 dnode_special_close(dnode_handle_t *dnh)
1292 {
1293 dnode_t *dn = dnh->dnh_dnode;
1294
1295 /*
1296 * Ensure dnode_rele_and_unlock() has released dn_mtx, after final
1297 * zfs_refcount_remove()
1298 */
1299 mutex_enter(&dn->dn_mtx);
1300 if (zfs_refcount_count(&dn->dn_holds) > 0)
1301 cv_wait(&dn->dn_nodnholds, &dn->dn_mtx);
1302 mutex_exit(&dn->dn_mtx);
1303 ASSERT3U(zfs_refcount_count(&dn->dn_holds), ==, 0);
1304
1305 ASSERT(dn->dn_dbuf == NULL ||
1306 dmu_buf_get_user(&dn->dn_dbuf->db) == NULL);
1307 zrl_add(&dnh->dnh_zrlock);
1308 dnode_destroy(dn); /* implicit zrl_remove() */
1309 zrl_destroy(&dnh->dnh_zrlock);
1310 dnh->dnh_dnode = NULL;
1311 }
1312
1313 void
dnode_special_open(objset_t * os,dnode_phys_t * dnp,uint64_t object,dnode_handle_t * dnh)1314 dnode_special_open(objset_t *os, dnode_phys_t *dnp, uint64_t object,
1315 dnode_handle_t *dnh)
1316 {
1317 dnode_t *dn;
1318
1319 zrl_init(&dnh->dnh_zrlock);
1320 VERIFY3U(1, ==, zrl_tryenter(&dnh->dnh_zrlock));
1321
1322 dn = dnode_create(os, dnp, NULL, object, dnh);
1323 DNODE_VERIFY(dn);
1324
1325 zrl_exit(&dnh->dnh_zrlock);
1326 }
1327
1328 static void
dnode_buf_evict_async(void * dbu)1329 dnode_buf_evict_async(void *dbu)
1330 {
1331 dnode_children_t *dnc = dbu;
1332
1333 DNODE_STAT_BUMP(dnode_buf_evict);
1334
1335 for (int i = 0; i < dnc->dnc_count; i++) {
1336 dnode_handle_t *dnh = &dnc->dnc_children[i];
1337 dnode_t *dn;
1338
1339 /*
1340 * The dnode handle lock guards against the dnode moving to
1341 * another valid address, so there is no need here to guard
1342 * against changes to or from NULL.
1343 */
1344 if (!DN_SLOT_IS_PTR(dnh->dnh_dnode)) {
1345 zrl_destroy(&dnh->dnh_zrlock);
1346 dnh->dnh_dnode = DN_SLOT_UNINIT;
1347 continue;
1348 }
1349
1350 zrl_add(&dnh->dnh_zrlock);
1351 dn = dnh->dnh_dnode;
1352 /*
1353 * If there are holds on this dnode, then there should
1354 * be holds on the dnode's containing dbuf as well; thus
1355 * it wouldn't be eligible for eviction and this function
1356 * would not have been called.
1357 */
1358 ASSERT(zfs_refcount_is_zero(&dn->dn_holds));
1359 ASSERT(zfs_refcount_is_zero(&dn->dn_tx_holds));
1360
1361 dnode_destroy(dn); /* implicit zrl_remove() for first slot */
1362 zrl_destroy(&dnh->dnh_zrlock);
1363 dnh->dnh_dnode = DN_SLOT_UNINIT;
1364 }
1365 kmem_free(dnc, sizeof (dnode_children_t) +
1366 dnc->dnc_count * sizeof (dnode_handle_t));
1367 }
1368
1369 /*
1370 * When the DNODE_MUST_BE_FREE flag is set, the "slots" parameter is used
1371 * to ensure the hole at the specified object offset is large enough to
1372 * hold the dnode being created. The slots parameter is also used to ensure
1373 * a dnode does not span multiple dnode blocks. In both of these cases, if
1374 * a failure occurs, ENOSPC is returned. Keep in mind, these failure cases
1375 * are only possible when using DNODE_MUST_BE_FREE.
1376 *
1377 * If the DNODE_MUST_BE_ALLOCATED flag is set, "slots" must be 0.
1378 * dnode_hold_impl() will check if the requested dnode is already consumed
1379 * as an extra dnode slot by an large dnode, in which case it returns
1380 * ENOENT.
1381 *
1382 * If the DNODE_DRY_RUN flag is set, we don't actually hold the dnode, just
1383 * return whether the hold would succeed or not. tag and dnp should set to
1384 * NULL in this case.
1385 *
1386 * errors:
1387 * EINVAL - Invalid object number or flags.
1388 * ENOSPC - Hole too small to fulfill "slots" request (DNODE_MUST_BE_FREE)
1389 * EEXIST - Refers to an allocated dnode (DNODE_MUST_BE_FREE)
1390 * - Refers to a freeing dnode (DNODE_MUST_BE_FREE)
1391 * - Refers to an interior dnode slot (DNODE_MUST_BE_ALLOCATED)
1392 * ENOENT - The requested dnode is not allocated (DNODE_MUST_BE_ALLOCATED)
1393 * - The requested dnode is being freed (DNODE_MUST_BE_ALLOCATED)
1394 * EIO - I/O error when reading the meta dnode dbuf.
1395 *
1396 * succeeds even for free dnodes.
1397 */
1398 int
dnode_hold_impl(objset_t * os,uint64_t object,int flag,int slots,void * tag,dnode_t ** dnp)1399 dnode_hold_impl(objset_t *os, uint64_t object, int flag, int slots,
1400 void *tag, dnode_t **dnp)
1401 {
1402 int epb, idx, err;
1403 int drop_struct_lock = FALSE;
1404 int type;
1405 uint64_t blk;
1406 dnode_t *mdn, *dn;
1407 dmu_buf_impl_t *db;
1408 dnode_children_t *dnc;
1409 dnode_phys_t *dn_block;
1410 dnode_handle_t *dnh;
1411
1412 ASSERT(!(flag & DNODE_MUST_BE_ALLOCATED) || (slots == 0));
1413 ASSERT(!(flag & DNODE_MUST_BE_FREE) || (slots > 0));
1414 IMPLY(flag & DNODE_DRY_RUN, (tag == NULL) && (dnp == NULL));
1415
1416 /*
1417 * If you are holding the spa config lock as writer, you shouldn't
1418 * be asking the DMU to do *anything* unless it's the root pool
1419 * which may require us to read from the root filesystem while
1420 * holding some (not all) of the locks as writer.
1421 */
1422 ASSERT(spa_config_held(os->os_spa, SCL_ALL, RW_WRITER) == 0 ||
1423 (spa_is_root(os->os_spa) &&
1424 spa_config_held(os->os_spa, SCL_STATE, RW_WRITER)));
1425
1426 ASSERT((flag & DNODE_MUST_BE_ALLOCATED) || (flag & DNODE_MUST_BE_FREE));
1427
1428 if (object == DMU_USERUSED_OBJECT || object == DMU_GROUPUSED_OBJECT ||
1429 object == DMU_PROJECTUSED_OBJECT) {
1430 if (object == DMU_USERUSED_OBJECT)
1431 dn = DMU_USERUSED_DNODE(os);
1432 else if (object == DMU_GROUPUSED_OBJECT)
1433 dn = DMU_GROUPUSED_DNODE(os);
1434 else
1435 dn = DMU_PROJECTUSED_DNODE(os);
1436 if (dn == NULL)
1437 return (SET_ERROR(ENOENT));
1438 type = dn->dn_type;
1439 if ((flag & DNODE_MUST_BE_ALLOCATED) && type == DMU_OT_NONE)
1440 return (SET_ERROR(ENOENT));
1441 if ((flag & DNODE_MUST_BE_FREE) && type != DMU_OT_NONE)
1442 return (SET_ERROR(EEXIST));
1443 DNODE_VERIFY(dn);
1444 /* Don't actually hold if dry run, just return 0 */
1445 if (!(flag & DNODE_DRY_RUN)) {
1446 (void) zfs_refcount_add(&dn->dn_holds, tag);
1447 *dnp = dn;
1448 }
1449 return (0);
1450 }
1451
1452 if (object == 0 || object >= DN_MAX_OBJECT)
1453 return (SET_ERROR(EINVAL));
1454
1455 mdn = DMU_META_DNODE(os);
1456 ASSERT(mdn->dn_object == DMU_META_DNODE_OBJECT);
1457
1458 DNODE_VERIFY(mdn);
1459
1460 if (!RW_WRITE_HELD(&mdn->dn_struct_rwlock)) {
1461 rw_enter(&mdn->dn_struct_rwlock, RW_READER);
1462 drop_struct_lock = TRUE;
1463 }
1464
1465 blk = dbuf_whichblock(mdn, 0, object * sizeof (dnode_phys_t));
1466 db = dbuf_hold(mdn, blk, FTAG);
1467 if (drop_struct_lock)
1468 rw_exit(&mdn->dn_struct_rwlock);
1469 if (db == NULL) {
1470 DNODE_STAT_BUMP(dnode_hold_dbuf_hold);
1471 return (SET_ERROR(EIO));
1472 }
1473
1474 /*
1475 * We do not need to decrypt to read the dnode so it doesn't matter
1476 * if we get the encrypted or decrypted version.
1477 */
1478 err = dbuf_read(db, NULL, DB_RF_CANFAIL |
1479 DB_RF_NO_DECRYPT | DB_RF_NOPREFETCH);
1480 if (err) {
1481 DNODE_STAT_BUMP(dnode_hold_dbuf_read);
1482 dbuf_rele(db, FTAG);
1483 return (err);
1484 }
1485
1486 ASSERT3U(db->db.db_size, >=, 1<<DNODE_SHIFT);
1487 epb = db->db.db_size >> DNODE_SHIFT;
1488
1489 idx = object & (epb - 1);
1490 dn_block = (dnode_phys_t *)db->db.db_data;
1491
1492 ASSERT(DB_DNODE(db)->dn_type == DMU_OT_DNODE);
1493 dnc = dmu_buf_get_user(&db->db);
1494 dnh = NULL;
1495 if (dnc == NULL) {
1496 dnode_children_t *winner;
1497 int skip = 0;
1498
1499 dnc = kmem_zalloc(sizeof (dnode_children_t) +
1500 epb * sizeof (dnode_handle_t), KM_SLEEP);
1501 dnc->dnc_count = epb;
1502 dnh = &dnc->dnc_children[0];
1503
1504 /* Initialize dnode slot status from dnode_phys_t */
1505 for (int i = 0; i < epb; i++) {
1506 zrl_init(&dnh[i].dnh_zrlock);
1507
1508 if (skip) {
1509 skip--;
1510 continue;
1511 }
1512
1513 if (dn_block[i].dn_type != DMU_OT_NONE) {
1514 int interior = dn_block[i].dn_extra_slots;
1515
1516 dnode_set_slots(dnc, i, 1, DN_SLOT_ALLOCATED);
1517 dnode_set_slots(dnc, i + 1, interior,
1518 DN_SLOT_INTERIOR);
1519 skip = interior;
1520 } else {
1521 dnh[i].dnh_dnode = DN_SLOT_FREE;
1522 skip = 0;
1523 }
1524 }
1525
1526 dmu_buf_init_user(&dnc->dnc_dbu, NULL,
1527 dnode_buf_evict_async, NULL);
1528 winner = dmu_buf_set_user(&db->db, &dnc->dnc_dbu);
1529 if (winner != NULL) {
1530
1531 for (int i = 0; i < epb; i++)
1532 zrl_destroy(&dnh[i].dnh_zrlock);
1533
1534 kmem_free(dnc, sizeof (dnode_children_t) +
1535 epb * sizeof (dnode_handle_t));
1536 dnc = winner;
1537 }
1538 }
1539
1540 ASSERT(dnc->dnc_count == epb);
1541
1542 if (flag & DNODE_MUST_BE_ALLOCATED) {
1543 slots = 1;
1544
1545 dnode_slots_hold(dnc, idx, slots);
1546 dnh = &dnc->dnc_children[idx];
1547
1548 if (DN_SLOT_IS_PTR(dnh->dnh_dnode)) {
1549 dn = dnh->dnh_dnode;
1550 } else if (dnh->dnh_dnode == DN_SLOT_INTERIOR) {
1551 DNODE_STAT_BUMP(dnode_hold_alloc_interior);
1552 dnode_slots_rele(dnc, idx, slots);
1553 dbuf_rele(db, FTAG);
1554 return (SET_ERROR(EEXIST));
1555 } else if (dnh->dnh_dnode != DN_SLOT_ALLOCATED) {
1556 DNODE_STAT_BUMP(dnode_hold_alloc_misses);
1557 dnode_slots_rele(dnc, idx, slots);
1558 dbuf_rele(db, FTAG);
1559 return (SET_ERROR(ENOENT));
1560 } else {
1561 dnode_slots_rele(dnc, idx, slots);
1562 while (!dnode_slots_tryenter(dnc, idx, slots)) {
1563 DNODE_STAT_BUMP(dnode_hold_alloc_lock_retry);
1564 cond_resched();
1565 }
1566
1567 /*
1568 * Someone else won the race and called dnode_create()
1569 * after we checked DN_SLOT_IS_PTR() above but before
1570 * we acquired the lock.
1571 */
1572 if (DN_SLOT_IS_PTR(dnh->dnh_dnode)) {
1573 DNODE_STAT_BUMP(dnode_hold_alloc_lock_misses);
1574 dn = dnh->dnh_dnode;
1575 } else {
1576 dn = dnode_create(os, dn_block + idx, db,
1577 object, dnh);
1578 }
1579 }
1580
1581 mutex_enter(&dn->dn_mtx);
1582 if (dn->dn_type == DMU_OT_NONE || dn->dn_free_txg != 0) {
1583 DNODE_STAT_BUMP(dnode_hold_alloc_type_none);
1584 mutex_exit(&dn->dn_mtx);
1585 dnode_slots_rele(dnc, idx, slots);
1586 dbuf_rele(db, FTAG);
1587 return (SET_ERROR(ENOENT));
1588 }
1589
1590 /* Don't actually hold if dry run, just return 0 */
1591 if (flag & DNODE_DRY_RUN) {
1592 mutex_exit(&dn->dn_mtx);
1593 dnode_slots_rele(dnc, idx, slots);
1594 dbuf_rele(db, FTAG);
1595 return (0);
1596 }
1597
1598 DNODE_STAT_BUMP(dnode_hold_alloc_hits);
1599 } else if (flag & DNODE_MUST_BE_FREE) {
1600
1601 if (idx + slots - 1 >= DNODES_PER_BLOCK) {
1602 DNODE_STAT_BUMP(dnode_hold_free_overflow);
1603 dbuf_rele(db, FTAG);
1604 return (SET_ERROR(ENOSPC));
1605 }
1606
1607 dnode_slots_hold(dnc, idx, slots);
1608
1609 if (!dnode_check_slots_free(dnc, idx, slots)) {
1610 DNODE_STAT_BUMP(dnode_hold_free_misses);
1611 dnode_slots_rele(dnc, idx, slots);
1612 dbuf_rele(db, FTAG);
1613 return (SET_ERROR(ENOSPC));
1614 }
1615
1616 dnode_slots_rele(dnc, idx, slots);
1617 while (!dnode_slots_tryenter(dnc, idx, slots)) {
1618 DNODE_STAT_BUMP(dnode_hold_free_lock_retry);
1619 cond_resched();
1620 }
1621
1622 if (!dnode_check_slots_free(dnc, idx, slots)) {
1623 DNODE_STAT_BUMP(dnode_hold_free_lock_misses);
1624 dnode_slots_rele(dnc, idx, slots);
1625 dbuf_rele(db, FTAG);
1626 return (SET_ERROR(ENOSPC));
1627 }
1628
1629 /*
1630 * Allocated but otherwise free dnodes which would
1631 * be in the interior of a multi-slot dnodes need
1632 * to be freed. Single slot dnodes can be safely
1633 * re-purposed as a performance optimization.
1634 */
1635 if (slots > 1)
1636 dnode_reclaim_slots(dnc, idx + 1, slots - 1);
1637
1638 dnh = &dnc->dnc_children[idx];
1639 if (DN_SLOT_IS_PTR(dnh->dnh_dnode)) {
1640 dn = dnh->dnh_dnode;
1641 } else {
1642 dn = dnode_create(os, dn_block + idx, db,
1643 object, dnh);
1644 }
1645
1646 mutex_enter(&dn->dn_mtx);
1647 if (!zfs_refcount_is_zero(&dn->dn_holds) || dn->dn_free_txg) {
1648 DNODE_STAT_BUMP(dnode_hold_free_refcount);
1649 mutex_exit(&dn->dn_mtx);
1650 dnode_slots_rele(dnc, idx, slots);
1651 dbuf_rele(db, FTAG);
1652 return (SET_ERROR(EEXIST));
1653 }
1654
1655 /* Don't actually hold if dry run, just return 0 */
1656 if (flag & DNODE_DRY_RUN) {
1657 mutex_exit(&dn->dn_mtx);
1658 dnode_slots_rele(dnc, idx, slots);
1659 dbuf_rele(db, FTAG);
1660 return (0);
1661 }
1662
1663 dnode_set_slots(dnc, idx + 1, slots - 1, DN_SLOT_INTERIOR);
1664 DNODE_STAT_BUMP(dnode_hold_free_hits);
1665 } else {
1666 dbuf_rele(db, FTAG);
1667 return (SET_ERROR(EINVAL));
1668 }
1669
1670 ASSERT0(dn->dn_free_txg);
1671
1672 if (zfs_refcount_add(&dn->dn_holds, tag) == 1)
1673 dbuf_add_ref(db, dnh);
1674
1675 mutex_exit(&dn->dn_mtx);
1676
1677 /* Now we can rely on the hold to prevent the dnode from moving. */
1678 dnode_slots_rele(dnc, idx, slots);
1679
1680 DNODE_VERIFY(dn);
1681 ASSERT3P(dnp, !=, NULL);
1682 ASSERT3P(dn->dn_dbuf, ==, db);
1683 ASSERT3U(dn->dn_object, ==, object);
1684 dbuf_rele(db, FTAG);
1685
1686 *dnp = dn;
1687 return (0);
1688 }
1689
1690 /*
1691 * Return held dnode if the object is allocated, NULL if not.
1692 */
1693 int
dnode_hold(objset_t * os,uint64_t object,void * tag,dnode_t ** dnp)1694 dnode_hold(objset_t *os, uint64_t object, void *tag, dnode_t **dnp)
1695 {
1696 return (dnode_hold_impl(os, object, DNODE_MUST_BE_ALLOCATED, 0, tag,
1697 dnp));
1698 }
1699
1700 /*
1701 * Can only add a reference if there is already at least one
1702 * reference on the dnode. Returns FALSE if unable to add a
1703 * new reference.
1704 */
1705 boolean_t
dnode_add_ref(dnode_t * dn,void * tag)1706 dnode_add_ref(dnode_t *dn, void *tag)
1707 {
1708 mutex_enter(&dn->dn_mtx);
1709 if (zfs_refcount_is_zero(&dn->dn_holds)) {
1710 mutex_exit(&dn->dn_mtx);
1711 return (FALSE);
1712 }
1713 VERIFY(1 < zfs_refcount_add(&dn->dn_holds, tag));
1714 mutex_exit(&dn->dn_mtx);
1715 return (TRUE);
1716 }
1717
1718 void
dnode_rele(dnode_t * dn,void * tag)1719 dnode_rele(dnode_t *dn, void *tag)
1720 {
1721 mutex_enter(&dn->dn_mtx);
1722 dnode_rele_and_unlock(dn, tag, B_FALSE);
1723 }
1724
1725 void
dnode_rele_and_unlock(dnode_t * dn,void * tag,boolean_t evicting)1726 dnode_rele_and_unlock(dnode_t *dn, void *tag, boolean_t evicting)
1727 {
1728 uint64_t refs;
1729 /* Get while the hold prevents the dnode from moving. */
1730 dmu_buf_impl_t *db = dn->dn_dbuf;
1731 dnode_handle_t *dnh = dn->dn_handle;
1732
1733 refs = zfs_refcount_remove(&dn->dn_holds, tag);
1734 if (refs == 0)
1735 cv_broadcast(&dn->dn_nodnholds);
1736 mutex_exit(&dn->dn_mtx);
1737 /* dnode could get destroyed at this point, so don't use it anymore */
1738
1739 /*
1740 * It's unsafe to release the last hold on a dnode by dnode_rele() or
1741 * indirectly by dbuf_rele() while relying on the dnode handle to
1742 * prevent the dnode from moving, since releasing the last hold could
1743 * result in the dnode's parent dbuf evicting its dnode handles. For
1744 * that reason anyone calling dnode_rele() or dbuf_rele() without some
1745 * other direct or indirect hold on the dnode must first drop the dnode
1746 * handle.
1747 */
1748 ASSERT(refs > 0 || dnh->dnh_zrlock.zr_owner != curthread);
1749
1750 /* NOTE: the DNODE_DNODE does not have a dn_dbuf */
1751 if (refs == 0 && db != NULL) {
1752 /*
1753 * Another thread could add a hold to the dnode handle in
1754 * dnode_hold_impl() while holding the parent dbuf. Since the
1755 * hold on the parent dbuf prevents the handle from being
1756 * destroyed, the hold on the handle is OK. We can't yet assert
1757 * that the handle has zero references, but that will be
1758 * asserted anyway when the handle gets destroyed.
1759 */
1760 mutex_enter(&db->db_mtx);
1761 dbuf_rele_and_unlock(db, dnh, evicting);
1762 }
1763 }
1764
1765 /*
1766 * Test whether we can create a dnode at the specified location.
1767 */
1768 int
dnode_try_claim(objset_t * os,uint64_t object,int slots)1769 dnode_try_claim(objset_t *os, uint64_t object, int slots)
1770 {
1771 return (dnode_hold_impl(os, object, DNODE_MUST_BE_FREE | DNODE_DRY_RUN,
1772 slots, NULL, NULL));
1773 }
1774
1775 /*
1776 * Checks if the dnode itself is dirty, or is carrying any uncommitted records.
1777 * It is important to check both conditions, as some operations (eg appending
1778 * to a file) can dirty both as a single logical unit, but they are not synced
1779 * out atomically, so checking one and not the other can result in an object
1780 * appearing to be clean mid-way through a commit.
1781 *
1782 * Do not change this lightly! If you get it wrong, dmu_offset_next() can
1783 * detect a hole where there is really data, leading to silent corruption.
1784 */
1785 boolean_t
dnode_is_dirty(dnode_t * dn)1786 dnode_is_dirty(dnode_t *dn)
1787 {
1788 mutex_enter(&dn->dn_mtx);
1789
1790 for (int i = 0; i < TXG_SIZE; i++) {
1791 if (multilist_link_active(&dn->dn_dirty_link[i]) ||
1792 !list_is_empty(&dn->dn_dirty_records[i])) {
1793 mutex_exit(&dn->dn_mtx);
1794 return (B_TRUE);
1795 }
1796 }
1797
1798 mutex_exit(&dn->dn_mtx);
1799
1800 return (B_FALSE);
1801 }
1802
1803 void
dnode_setdirty(dnode_t * dn,dmu_tx_t * tx)1804 dnode_setdirty(dnode_t *dn, dmu_tx_t *tx)
1805 {
1806 objset_t *os = dn->dn_objset;
1807 uint64_t txg = tx->tx_txg;
1808
1809 if (DMU_OBJECT_IS_SPECIAL(dn->dn_object)) {
1810 dsl_dataset_dirty(os->os_dsl_dataset, tx);
1811 return;
1812 }
1813
1814 DNODE_VERIFY(dn);
1815
1816 #ifdef ZFS_DEBUG
1817 mutex_enter(&dn->dn_mtx);
1818 ASSERT(dn->dn_phys->dn_type || dn->dn_allocated_txg);
1819 ASSERT(dn->dn_free_txg == 0 || dn->dn_free_txg >= txg);
1820 mutex_exit(&dn->dn_mtx);
1821 #endif
1822
1823 /*
1824 * Determine old uid/gid when necessary
1825 */
1826 dmu_objset_userquota_get_ids(dn, B_TRUE, tx);
1827
1828 multilist_t *dirtylist = &os->os_dirty_dnodes[txg & TXG_MASK];
1829 multilist_sublist_t *mls = multilist_sublist_lock_obj(dirtylist, dn);
1830
1831 /*
1832 * If we are already marked dirty, we're done.
1833 */
1834 if (multilist_link_active(&dn->dn_dirty_link[txg & TXG_MASK])) {
1835 multilist_sublist_unlock(mls);
1836 return;
1837 }
1838
1839 ASSERT(!zfs_refcount_is_zero(&dn->dn_holds) ||
1840 !avl_is_empty(&dn->dn_dbufs));
1841 ASSERT(dn->dn_datablksz != 0);
1842 ASSERT0(dn->dn_next_bonuslen[txg & TXG_MASK]);
1843 ASSERT0(dn->dn_next_blksz[txg & TXG_MASK]);
1844 ASSERT0(dn->dn_next_bonustype[txg & TXG_MASK]);
1845
1846 dprintf_ds(os->os_dsl_dataset, "obj=%llu txg=%llu\n",
1847 (u_longlong_t)dn->dn_object, (u_longlong_t)txg);
1848
1849 multilist_sublist_insert_head(mls, dn);
1850
1851 multilist_sublist_unlock(mls);
1852
1853 /*
1854 * The dnode maintains a hold on its containing dbuf as
1855 * long as there are holds on it. Each instantiated child
1856 * dbuf maintains a hold on the dnode. When the last child
1857 * drops its hold, the dnode will drop its hold on the
1858 * containing dbuf. We add a "dirty hold" here so that the
1859 * dnode will hang around after we finish processing its
1860 * children.
1861 */
1862 VERIFY(dnode_add_ref(dn, (void *)(uintptr_t)tx->tx_txg));
1863
1864 (void) dbuf_dirty(dn->dn_dbuf, tx);
1865
1866 dsl_dataset_dirty(os->os_dsl_dataset, tx);
1867 }
1868
1869 void
dnode_free(dnode_t * dn,dmu_tx_t * tx)1870 dnode_free(dnode_t *dn, dmu_tx_t *tx)
1871 {
1872 mutex_enter(&dn->dn_mtx);
1873 if (dn->dn_type == DMU_OT_NONE || dn->dn_free_txg) {
1874 mutex_exit(&dn->dn_mtx);
1875 return;
1876 }
1877 dn->dn_free_txg = tx->tx_txg;
1878 mutex_exit(&dn->dn_mtx);
1879
1880 dnode_setdirty(dn, tx);
1881 }
1882
1883 /*
1884 * Try to change the block size for the indicated dnode. This can only
1885 * succeed if there are no blocks allocated or dirty beyond first block
1886 */
1887 int
dnode_set_blksz(dnode_t * dn,uint64_t size,int ibs,dmu_tx_t * tx)1888 dnode_set_blksz(dnode_t *dn, uint64_t size, int ibs, dmu_tx_t *tx)
1889 {
1890 dmu_buf_impl_t *db;
1891 int err;
1892
1893 ASSERT3U(size, <=, spa_maxblocksize(dmu_objset_spa(dn->dn_objset)));
1894 if (size == 0)
1895 size = SPA_MINBLOCKSIZE;
1896 else
1897 size = P2ROUNDUP(size, SPA_MINBLOCKSIZE);
1898
1899 if (ibs == dn->dn_indblkshift)
1900 ibs = 0;
1901
1902 if (size == dn->dn_datablksz && ibs == 0)
1903 return (0);
1904
1905 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
1906
1907 /* Check for any allocated blocks beyond the first */
1908 if (dn->dn_maxblkid != 0)
1909 goto fail;
1910
1911 mutex_enter(&dn->dn_dbufs_mtx);
1912 for (db = avl_first(&dn->dn_dbufs); db != NULL;
1913 db = AVL_NEXT(&dn->dn_dbufs, db)) {
1914 if (db->db_blkid != 0 && db->db_blkid != DMU_BONUS_BLKID &&
1915 db->db_blkid != DMU_SPILL_BLKID) {
1916 mutex_exit(&dn->dn_dbufs_mtx);
1917 goto fail;
1918 }
1919 }
1920 mutex_exit(&dn->dn_dbufs_mtx);
1921
1922 if (ibs && dn->dn_nlevels != 1)
1923 goto fail;
1924
1925 dnode_setdirty(dn, tx);
1926 if (size != dn->dn_datablksz) {
1927 /* resize the old block */
1928 err = dbuf_hold_impl(dn, 0, 0, TRUE, FALSE, FTAG, &db);
1929 if (err == 0) {
1930 dbuf_new_size(db, size, tx);
1931 } else if (err != ENOENT) {
1932 goto fail;
1933 }
1934
1935 dnode_setdblksz(dn, size);
1936 dn->dn_next_blksz[tx->tx_txg & TXG_MASK] = size;
1937 if (db)
1938 dbuf_rele(db, FTAG);
1939 }
1940 if (ibs) {
1941 dn->dn_indblkshift = ibs;
1942 dn->dn_next_indblkshift[tx->tx_txg & TXG_MASK] = ibs;
1943 }
1944
1945 rw_exit(&dn->dn_struct_rwlock);
1946 return (0);
1947
1948 fail:
1949 rw_exit(&dn->dn_struct_rwlock);
1950 return (SET_ERROR(ENOTSUP));
1951 }
1952
1953 static void
dnode_set_nlevels_impl(dnode_t * dn,int new_nlevels,dmu_tx_t * tx)1954 dnode_set_nlevels_impl(dnode_t *dn, int new_nlevels, dmu_tx_t *tx)
1955 {
1956 uint64_t txgoff = tx->tx_txg & TXG_MASK;
1957 int old_nlevels = dn->dn_nlevels;
1958 dmu_buf_impl_t *db;
1959 list_t *list;
1960 dbuf_dirty_record_t *new, *dr, *dr_next;
1961
1962 ASSERT(RW_WRITE_HELD(&dn->dn_struct_rwlock));
1963
1964 ASSERT3U(new_nlevels, >, dn->dn_nlevels);
1965 dn->dn_nlevels = new_nlevels;
1966
1967 ASSERT3U(new_nlevels, >, dn->dn_next_nlevels[txgoff]);
1968 dn->dn_next_nlevels[txgoff] = new_nlevels;
1969
1970 /* dirty the left indirects */
1971 db = dbuf_hold_level(dn, old_nlevels, 0, FTAG);
1972 ASSERT(db != NULL);
1973 new = dbuf_dirty(db, tx);
1974 dbuf_rele(db, FTAG);
1975
1976 /* transfer the dirty records to the new indirect */
1977 mutex_enter(&dn->dn_mtx);
1978 mutex_enter(&new->dt.di.dr_mtx);
1979 list = &dn->dn_dirty_records[txgoff];
1980 for (dr = list_head(list); dr; dr = dr_next) {
1981 dr_next = list_next(&dn->dn_dirty_records[txgoff], dr);
1982
1983 IMPLY(dr->dr_dbuf == NULL, old_nlevels == 1);
1984 if (dr->dr_dbuf == NULL ||
1985 (dr->dr_dbuf->db_level == old_nlevels - 1 &&
1986 dr->dr_dbuf->db_blkid != DMU_BONUS_BLKID &&
1987 dr->dr_dbuf->db_blkid != DMU_SPILL_BLKID)) {
1988 list_remove(&dn->dn_dirty_records[txgoff], dr);
1989 list_insert_tail(&new->dt.di.dr_children, dr);
1990 dr->dr_parent = new;
1991 }
1992 }
1993 mutex_exit(&new->dt.di.dr_mtx);
1994 mutex_exit(&dn->dn_mtx);
1995 }
1996
1997 int
dnode_set_nlevels(dnode_t * dn,int nlevels,dmu_tx_t * tx)1998 dnode_set_nlevels(dnode_t *dn, int nlevels, dmu_tx_t *tx)
1999 {
2000 int ret = 0;
2001
2002 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
2003
2004 if (dn->dn_nlevels == nlevels) {
2005 ret = 0;
2006 goto out;
2007 } else if (nlevels < dn->dn_nlevels) {
2008 ret = SET_ERROR(EINVAL);
2009 goto out;
2010 }
2011
2012 dnode_set_nlevels_impl(dn, nlevels, tx);
2013
2014 out:
2015 rw_exit(&dn->dn_struct_rwlock);
2016 return (ret);
2017 }
2018
2019 /* read-holding callers must not rely on the lock being continuously held */
2020 void
dnode_new_blkid(dnode_t * dn,uint64_t blkid,dmu_tx_t * tx,boolean_t have_read,boolean_t force)2021 dnode_new_blkid(dnode_t *dn, uint64_t blkid, dmu_tx_t *tx, boolean_t have_read,
2022 boolean_t force)
2023 {
2024 int epbs, new_nlevels;
2025 uint64_t sz;
2026
2027 ASSERT(blkid != DMU_BONUS_BLKID);
2028
2029 ASSERT(have_read ?
2030 RW_READ_HELD(&dn->dn_struct_rwlock) :
2031 RW_WRITE_HELD(&dn->dn_struct_rwlock));
2032
2033 /*
2034 * if we have a read-lock, check to see if we need to do any work
2035 * before upgrading to a write-lock.
2036 */
2037 if (have_read) {
2038 if (blkid <= dn->dn_maxblkid)
2039 return;
2040
2041 if (!rw_tryupgrade(&dn->dn_struct_rwlock)) {
2042 rw_exit(&dn->dn_struct_rwlock);
2043 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
2044 }
2045 }
2046
2047 /*
2048 * Raw sends (indicated by the force flag) require that we take the
2049 * given blkid even if the value is lower than the current value.
2050 */
2051 if (!force && blkid <= dn->dn_maxblkid)
2052 goto out;
2053
2054 /*
2055 * We use the (otherwise unused) top bit of dn_next_maxblkid[txgoff]
2056 * to indicate that this field is set. This allows us to set the
2057 * maxblkid to 0 on an existing object in dnode_sync().
2058 */
2059 dn->dn_maxblkid = blkid;
2060 dn->dn_next_maxblkid[tx->tx_txg & TXG_MASK] =
2061 blkid | DMU_NEXT_MAXBLKID_SET;
2062
2063 /*
2064 * Compute the number of levels necessary to support the new maxblkid.
2065 * Raw sends will ensure nlevels is set correctly for us.
2066 */
2067 new_nlevels = 1;
2068 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT;
2069 for (sz = dn->dn_nblkptr;
2070 sz <= blkid && sz >= dn->dn_nblkptr; sz <<= epbs)
2071 new_nlevels++;
2072
2073 ASSERT3U(new_nlevels, <=, DN_MAX_LEVELS);
2074
2075 if (!force) {
2076 if (new_nlevels > dn->dn_nlevels)
2077 dnode_set_nlevels_impl(dn, new_nlevels, tx);
2078 } else {
2079 ASSERT3U(dn->dn_nlevels, >=, new_nlevels);
2080 }
2081
2082 out:
2083 if (have_read)
2084 rw_downgrade(&dn->dn_struct_rwlock);
2085 }
2086
2087 static void
dnode_dirty_l1(dnode_t * dn,uint64_t l1blkid,dmu_tx_t * tx)2088 dnode_dirty_l1(dnode_t *dn, uint64_t l1blkid, dmu_tx_t *tx)
2089 {
2090 dmu_buf_impl_t *db = dbuf_hold_level(dn, 1, l1blkid, FTAG);
2091 if (db != NULL) {
2092 dmu_buf_will_dirty(&db->db, tx);
2093 dbuf_rele(db, FTAG);
2094 }
2095 }
2096
2097 /*
2098 * Dirty all the in-core level-1 dbufs in the range specified by start_blkid
2099 * and end_blkid.
2100 */
2101 static void
dnode_dirty_l1range(dnode_t * dn,uint64_t start_blkid,uint64_t end_blkid,dmu_tx_t * tx)2102 dnode_dirty_l1range(dnode_t *dn, uint64_t start_blkid, uint64_t end_blkid,
2103 dmu_tx_t *tx)
2104 {
2105 dmu_buf_impl_t *db_search;
2106 dmu_buf_impl_t *db;
2107 avl_index_t where;
2108
2109 db_search = kmem_zalloc(sizeof (dmu_buf_impl_t), KM_SLEEP);
2110
2111 mutex_enter(&dn->dn_dbufs_mtx);
2112
2113 db_search->db_level = 1;
2114 db_search->db_blkid = start_blkid + 1;
2115 db_search->db_state = DB_SEARCH;
2116 for (;;) {
2117
2118 db = avl_find(&dn->dn_dbufs, db_search, &where);
2119 if (db == NULL)
2120 db = avl_nearest(&dn->dn_dbufs, where, AVL_AFTER);
2121
2122 if (db == NULL || db->db_level != 1 ||
2123 db->db_blkid >= end_blkid) {
2124 break;
2125 }
2126
2127 /*
2128 * Setup the next blkid we want to search for.
2129 */
2130 db_search->db_blkid = db->db_blkid + 1;
2131 ASSERT3U(db->db_blkid, >=, start_blkid);
2132
2133 /*
2134 * If the dbuf transitions to DB_EVICTING while we're trying
2135 * to dirty it, then we will be unable to discover it in
2136 * the dbuf hash table. This will result in a call to
2137 * dbuf_create() which needs to acquire the dn_dbufs_mtx
2138 * lock. To avoid a deadlock, we drop the lock before
2139 * dirtying the level-1 dbuf.
2140 */
2141 mutex_exit(&dn->dn_dbufs_mtx);
2142 dnode_dirty_l1(dn, db->db_blkid, tx);
2143 mutex_enter(&dn->dn_dbufs_mtx);
2144 }
2145
2146 #ifdef ZFS_DEBUG
2147 /*
2148 * Walk all the in-core level-1 dbufs and verify they have been dirtied.
2149 */
2150 db_search->db_level = 1;
2151 db_search->db_blkid = start_blkid + 1;
2152 db_search->db_state = DB_SEARCH;
2153 db = avl_find(&dn->dn_dbufs, db_search, &where);
2154 if (db == NULL)
2155 db = avl_nearest(&dn->dn_dbufs, where, AVL_AFTER);
2156 for (; db != NULL; db = AVL_NEXT(&dn->dn_dbufs, db)) {
2157 if (db->db_level != 1 || db->db_blkid >= end_blkid)
2158 break;
2159 if (db->db_state != DB_EVICTING)
2160 ASSERT(db->db_dirtycnt > 0);
2161 }
2162 #endif
2163 kmem_free(db_search, sizeof (dmu_buf_impl_t));
2164 mutex_exit(&dn->dn_dbufs_mtx);
2165 }
2166
2167 void
dnode_set_dirtyctx(dnode_t * dn,dmu_tx_t * tx,void * tag)2168 dnode_set_dirtyctx(dnode_t *dn, dmu_tx_t *tx, void *tag)
2169 {
2170 /*
2171 * Don't set dirtyctx to SYNC if we're just modifying this as we
2172 * initialize the objset.
2173 */
2174 if (dn->dn_dirtyctx == DN_UNDIRTIED) {
2175 dsl_dataset_t *ds = dn->dn_objset->os_dsl_dataset;
2176
2177 if (ds != NULL) {
2178 rrw_enter(&ds->ds_bp_rwlock, RW_READER, tag);
2179 }
2180 if (!BP_IS_HOLE(dn->dn_objset->os_rootbp)) {
2181 if (dmu_tx_is_syncing(tx))
2182 dn->dn_dirtyctx = DN_DIRTY_SYNC;
2183 else
2184 dn->dn_dirtyctx = DN_DIRTY_OPEN;
2185 dn->dn_dirtyctx_firstset = tag;
2186 }
2187 if (ds != NULL) {
2188 rrw_exit(&ds->ds_bp_rwlock, tag);
2189 }
2190 }
2191 }
2192
2193 void
dnode_free_range(dnode_t * dn,uint64_t off,uint64_t len,dmu_tx_t * tx)2194 dnode_free_range(dnode_t *dn, uint64_t off, uint64_t len, dmu_tx_t *tx)
2195 {
2196 dmu_buf_impl_t *db;
2197 uint64_t blkoff, blkid, nblks;
2198 int blksz, blkshift, head, tail;
2199 int trunc = FALSE;
2200 int epbs;
2201
2202 blksz = dn->dn_datablksz;
2203 blkshift = dn->dn_datablkshift;
2204 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT;
2205
2206 if (len == DMU_OBJECT_END) {
2207 len = UINT64_MAX - off;
2208 trunc = TRUE;
2209 }
2210
2211 /*
2212 * First, block align the region to free:
2213 */
2214 if (ISP2(blksz)) {
2215 head = P2NPHASE(off, blksz);
2216 blkoff = P2PHASE(off, blksz);
2217 if ((off >> blkshift) > dn->dn_maxblkid)
2218 return;
2219 } else {
2220 ASSERT(dn->dn_maxblkid == 0);
2221 if (off == 0 && len >= blksz) {
2222 /*
2223 * Freeing the whole block; fast-track this request.
2224 */
2225 blkid = 0;
2226 nblks = 1;
2227 if (dn->dn_nlevels > 1) {
2228 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
2229 dnode_dirty_l1(dn, 0, tx);
2230 rw_exit(&dn->dn_struct_rwlock);
2231 }
2232 goto done;
2233 } else if (off >= blksz) {
2234 /* Freeing past end-of-data */
2235 return;
2236 } else {
2237 /* Freeing part of the block. */
2238 head = blksz - off;
2239 ASSERT3U(head, >, 0);
2240 }
2241 blkoff = off;
2242 }
2243 /* zero out any partial block data at the start of the range */
2244 if (head) {
2245 int res;
2246 ASSERT3U(blkoff + head, ==, blksz);
2247 if (len < head)
2248 head = len;
2249 rw_enter(&dn->dn_struct_rwlock, RW_READER);
2250 res = dbuf_hold_impl(dn, 0, dbuf_whichblock(dn, 0, off),
2251 TRUE, FALSE, FTAG, &db);
2252 rw_exit(&dn->dn_struct_rwlock);
2253 if (res == 0) {
2254 caddr_t data;
2255 boolean_t dirty;
2256
2257 db_lock_type_t dblt = dmu_buf_lock_parent(db, RW_READER,
2258 FTAG);
2259 /* don't dirty if it isn't on disk and isn't dirty */
2260 dirty = !list_is_empty(&db->db_dirty_records) ||
2261 (db->db_blkptr && !BP_IS_HOLE(db->db_blkptr));
2262 dmu_buf_unlock_parent(db, dblt, FTAG);
2263 if (dirty) {
2264 dmu_buf_will_dirty(&db->db, tx);
2265 data = db->db.db_data;
2266 bzero(data + blkoff, head);
2267 }
2268 dbuf_rele(db, FTAG);
2269 }
2270 off += head;
2271 len -= head;
2272 }
2273
2274 /* If the range was less than one block, we're done */
2275 if (len == 0)
2276 return;
2277
2278 /* If the remaining range is past end of file, we're done */
2279 if ((off >> blkshift) > dn->dn_maxblkid)
2280 return;
2281
2282 ASSERT(ISP2(blksz));
2283 if (trunc)
2284 tail = 0;
2285 else
2286 tail = P2PHASE(len, blksz);
2287
2288 ASSERT0(P2PHASE(off, blksz));
2289 /* zero out any partial block data at the end of the range */
2290 if (tail) {
2291 int res;
2292 if (len < tail)
2293 tail = len;
2294 rw_enter(&dn->dn_struct_rwlock, RW_READER);
2295 res = dbuf_hold_impl(dn, 0, dbuf_whichblock(dn, 0, off+len),
2296 TRUE, FALSE, FTAG, &db);
2297 rw_exit(&dn->dn_struct_rwlock);
2298 if (res == 0) {
2299 boolean_t dirty;
2300 /* don't dirty if not on disk and not dirty */
2301 db_lock_type_t type = dmu_buf_lock_parent(db, RW_READER,
2302 FTAG);
2303 dirty = !list_is_empty(&db->db_dirty_records) ||
2304 (db->db_blkptr && !BP_IS_HOLE(db->db_blkptr));
2305 dmu_buf_unlock_parent(db, type, FTAG);
2306 if (dirty) {
2307 dmu_buf_will_dirty(&db->db, tx);
2308 bzero(db->db.db_data, tail);
2309 }
2310 dbuf_rele(db, FTAG);
2311 }
2312 len -= tail;
2313 }
2314
2315 /* If the range did not include a full block, we are done */
2316 if (len == 0)
2317 return;
2318
2319 ASSERT(IS_P2ALIGNED(off, blksz));
2320 ASSERT(trunc || IS_P2ALIGNED(len, blksz));
2321 blkid = off >> blkshift;
2322 nblks = len >> blkshift;
2323 if (trunc)
2324 nblks += 1;
2325
2326 /*
2327 * Dirty all the indirect blocks in this range. Note that only
2328 * the first and last indirect blocks can actually be written
2329 * (if they were partially freed) -- they must be dirtied, even if
2330 * they do not exist on disk yet. The interior blocks will
2331 * be freed by free_children(), so they will not actually be written.
2332 * Even though these interior blocks will not be written, we
2333 * dirty them for two reasons:
2334 *
2335 * - It ensures that the indirect blocks remain in memory until
2336 * syncing context. (They have already been prefetched by
2337 * dmu_tx_hold_free(), so we don't have to worry about reading
2338 * them serially here.)
2339 *
2340 * - The dirty space accounting will put pressure on the txg sync
2341 * mechanism to begin syncing, and to delay transactions if there
2342 * is a large amount of freeing. Even though these indirect
2343 * blocks will not be written, we could need to write the same
2344 * amount of space if we copy the freed BPs into deadlists.
2345 */
2346 if (dn->dn_nlevels > 1) {
2347 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
2348 uint64_t first, last;
2349
2350 first = blkid >> epbs;
2351 dnode_dirty_l1(dn, first, tx);
2352 if (trunc)
2353 last = dn->dn_maxblkid >> epbs;
2354 else
2355 last = (blkid + nblks - 1) >> epbs;
2356 if (last != first)
2357 dnode_dirty_l1(dn, last, tx);
2358
2359 dnode_dirty_l1range(dn, first, last, tx);
2360
2361 int shift = dn->dn_datablkshift + dn->dn_indblkshift -
2362 SPA_BLKPTRSHIFT;
2363 for (uint64_t i = first + 1; i < last; i++) {
2364 /*
2365 * Set i to the blockid of the next non-hole
2366 * level-1 indirect block at or after i. Note
2367 * that dnode_next_offset() operates in terms of
2368 * level-0-equivalent bytes.
2369 */
2370 uint64_t ibyte = i << shift;
2371 int err = dnode_next_offset(dn, DNODE_FIND_HAVELOCK,
2372 &ibyte, 2, 1, 0);
2373 i = ibyte >> shift;
2374 if (i >= last)
2375 break;
2376
2377 /*
2378 * Normally we should not see an error, either
2379 * from dnode_next_offset() or dbuf_hold_level()
2380 * (except for ESRCH from dnode_next_offset).
2381 * If there is an i/o error, then when we read
2382 * this block in syncing context, it will use
2383 * ZIO_FLAG_MUSTSUCCEED, and thus hang/panic according
2384 * to the "failmode" property. dnode_next_offset()
2385 * doesn't have a flag to indicate MUSTSUCCEED.
2386 */
2387 if (err != 0)
2388 break;
2389
2390 dnode_dirty_l1(dn, i, tx);
2391 }
2392 rw_exit(&dn->dn_struct_rwlock);
2393 }
2394
2395 done:
2396 /*
2397 * Add this range to the dnode range list.
2398 * We will finish up this free operation in the syncing phase.
2399 */
2400 mutex_enter(&dn->dn_mtx);
2401 {
2402 int txgoff = tx->tx_txg & TXG_MASK;
2403 if (dn->dn_free_ranges[txgoff] == NULL) {
2404 dn->dn_free_ranges[txgoff] = range_tree_create(NULL,
2405 RANGE_SEG64, NULL, 0, 0);
2406 }
2407 range_tree_clear(dn->dn_free_ranges[txgoff], blkid, nblks);
2408 range_tree_add(dn->dn_free_ranges[txgoff], blkid, nblks);
2409 }
2410 dprintf_dnode(dn, "blkid=%llu nblks=%llu txg=%llu\n",
2411 (u_longlong_t)blkid, (u_longlong_t)nblks,
2412 (u_longlong_t)tx->tx_txg);
2413 mutex_exit(&dn->dn_mtx);
2414
2415 dbuf_free_range(dn, blkid, blkid + nblks - 1, tx);
2416 dnode_setdirty(dn, tx);
2417 }
2418
2419 static boolean_t
dnode_spill_freed(dnode_t * dn)2420 dnode_spill_freed(dnode_t *dn)
2421 {
2422 int i;
2423
2424 mutex_enter(&dn->dn_mtx);
2425 for (i = 0; i < TXG_SIZE; i++) {
2426 if (dn->dn_rm_spillblk[i] == DN_KILL_SPILLBLK)
2427 break;
2428 }
2429 mutex_exit(&dn->dn_mtx);
2430 return (i < TXG_SIZE);
2431 }
2432
2433 /* return TRUE if this blkid was freed in a recent txg, or FALSE if it wasn't */
2434 uint64_t
dnode_block_freed(dnode_t * dn,uint64_t blkid)2435 dnode_block_freed(dnode_t *dn, uint64_t blkid)
2436 {
2437 int i;
2438
2439 if (blkid == DMU_BONUS_BLKID)
2440 return (FALSE);
2441
2442 if (dn->dn_free_txg)
2443 return (TRUE);
2444
2445 if (blkid == DMU_SPILL_BLKID)
2446 return (dnode_spill_freed(dn));
2447
2448 mutex_enter(&dn->dn_mtx);
2449 for (i = 0; i < TXG_SIZE; i++) {
2450 if (dn->dn_free_ranges[i] != NULL &&
2451 range_tree_contains(dn->dn_free_ranges[i], blkid, 1))
2452 break;
2453 }
2454 mutex_exit(&dn->dn_mtx);
2455 return (i < TXG_SIZE);
2456 }
2457
2458 /* call from syncing context when we actually write/free space for this dnode */
2459 void
dnode_diduse_space(dnode_t * dn,int64_t delta)2460 dnode_diduse_space(dnode_t *dn, int64_t delta)
2461 {
2462 uint64_t space;
2463 dprintf_dnode(dn, "dn=%p dnp=%p used=%llu delta=%lld\n",
2464 dn, dn->dn_phys,
2465 (u_longlong_t)dn->dn_phys->dn_used,
2466 (longlong_t)delta);
2467
2468 mutex_enter(&dn->dn_mtx);
2469 space = DN_USED_BYTES(dn->dn_phys);
2470 if (delta > 0) {
2471 ASSERT3U(space + delta, >=, space); /* no overflow */
2472 } else {
2473 ASSERT3U(space, >=, -delta); /* no underflow */
2474 }
2475 space += delta;
2476 if (spa_version(dn->dn_objset->os_spa) < SPA_VERSION_DNODE_BYTES) {
2477 ASSERT((dn->dn_phys->dn_flags & DNODE_FLAG_USED_BYTES) == 0);
2478 ASSERT0(P2PHASE(space, 1<<DEV_BSHIFT));
2479 dn->dn_phys->dn_used = space >> DEV_BSHIFT;
2480 } else {
2481 dn->dn_phys->dn_used = space;
2482 dn->dn_phys->dn_flags |= DNODE_FLAG_USED_BYTES;
2483 }
2484 mutex_exit(&dn->dn_mtx);
2485 }
2486
2487 /*
2488 * Scans a block at the indicated "level" looking for a hole or data,
2489 * depending on 'flags'.
2490 *
2491 * If level > 0, then we are scanning an indirect block looking at its
2492 * pointers. If level == 0, then we are looking at a block of dnodes.
2493 *
2494 * If we don't find what we are looking for in the block, we return ESRCH.
2495 * Otherwise, return with *offset pointing to the beginning (if searching
2496 * forwards) or end (if searching backwards) of the range covered by the
2497 * block pointer we matched on (or dnode).
2498 *
2499 * The basic search algorithm used below by dnode_next_offset() is to
2500 * use this function to search up the block tree (widen the search) until
2501 * we find something (i.e., we don't return ESRCH) and then search back
2502 * down the tree (narrow the search) until we reach our original search
2503 * level.
2504 */
2505 static int
dnode_next_offset_level(dnode_t * dn,int flags,uint64_t * offset,int lvl,uint64_t blkfill,uint64_t txg)2506 dnode_next_offset_level(dnode_t *dn, int flags, uint64_t *offset,
2507 int lvl, uint64_t blkfill, uint64_t txg)
2508 {
2509 dmu_buf_impl_t *db = NULL;
2510 void *data = NULL;
2511 uint64_t epbs = dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT;
2512 uint64_t epb = 1ULL << epbs;
2513 uint64_t minfill, maxfill;
2514 boolean_t hole;
2515 int i, inc, error, span;
2516
2517 ASSERT(RW_LOCK_HELD(&dn->dn_struct_rwlock));
2518
2519 hole = ((flags & DNODE_FIND_HOLE) != 0);
2520 inc = (flags & DNODE_FIND_BACKWARDS) ? -1 : 1;
2521 ASSERT(txg == 0 || !hole);
2522
2523 if (lvl == dn->dn_phys->dn_nlevels) {
2524 error = 0;
2525 epb = dn->dn_phys->dn_nblkptr;
2526 data = dn->dn_phys->dn_blkptr;
2527 } else {
2528 uint64_t blkid = dbuf_whichblock(dn, lvl, *offset);
2529 error = dbuf_hold_impl(dn, lvl, blkid, TRUE, FALSE, FTAG, &db);
2530 if (error) {
2531 if (error != ENOENT)
2532 return (error);
2533 if (hole)
2534 return (0);
2535 /*
2536 * This can only happen when we are searching up
2537 * the block tree for data. We don't really need to
2538 * adjust the offset, as we will just end up looking
2539 * at the pointer to this block in its parent, and its
2540 * going to be unallocated, so we will skip over it.
2541 */
2542 return (SET_ERROR(ESRCH));
2543 }
2544 error = dbuf_read(db, NULL,
2545 DB_RF_CANFAIL | DB_RF_HAVESTRUCT |
2546 DB_RF_NO_DECRYPT | DB_RF_NOPREFETCH);
2547 if (error) {
2548 dbuf_rele(db, FTAG);
2549 return (error);
2550 }
2551 data = db->db.db_data;
2552 rw_enter(&db->db_rwlock, RW_READER);
2553 }
2554
2555 if (db != NULL && txg != 0 && (db->db_blkptr == NULL ||
2556 db->db_blkptr->blk_birth <= txg ||
2557 BP_IS_HOLE(db->db_blkptr))) {
2558 /*
2559 * This can only happen when we are searching up the tree
2560 * and these conditions mean that we need to keep climbing.
2561 */
2562 error = SET_ERROR(ESRCH);
2563 } else if (lvl == 0) {
2564 dnode_phys_t *dnp = data;
2565
2566 ASSERT(dn->dn_type == DMU_OT_DNODE);
2567 ASSERT(!(flags & DNODE_FIND_BACKWARDS));
2568
2569 for (i = (*offset >> DNODE_SHIFT) & (blkfill - 1);
2570 i < blkfill; i += dnp[i].dn_extra_slots + 1) {
2571 if ((dnp[i].dn_type == DMU_OT_NONE) == hole)
2572 break;
2573 }
2574
2575 if (i == blkfill)
2576 error = SET_ERROR(ESRCH);
2577
2578 *offset = (*offset & ~(DNODE_BLOCK_SIZE - 1)) +
2579 (i << DNODE_SHIFT);
2580 } else {
2581 blkptr_t *bp = data;
2582 uint64_t start = *offset;
2583 span = (lvl - 1) * epbs + dn->dn_datablkshift;
2584 minfill = 0;
2585 maxfill = blkfill << ((lvl - 1) * epbs);
2586
2587 if (hole)
2588 maxfill--;
2589 else
2590 minfill++;
2591
2592 if (span >= 8 * sizeof (*offset)) {
2593 /* This only happens on the highest indirection level */
2594 ASSERT3U((lvl - 1), ==, dn->dn_phys->dn_nlevels - 1);
2595 *offset = 0;
2596 } else {
2597 *offset = *offset >> span;
2598 }
2599
2600 for (i = BF64_GET(*offset, 0, epbs);
2601 i >= 0 && i < epb; i += inc) {
2602 if (BP_GET_FILL(&bp[i]) >= minfill &&
2603 BP_GET_FILL(&bp[i]) <= maxfill &&
2604 (hole || bp[i].blk_birth > txg))
2605 break;
2606 if (inc > 0 || *offset > 0)
2607 *offset += inc;
2608 }
2609
2610 if (span >= 8 * sizeof (*offset)) {
2611 *offset = start;
2612 } else {
2613 *offset = *offset << span;
2614 }
2615
2616 if (inc < 0) {
2617 /* traversing backwards; position offset at the end */
2618 ASSERT3U(*offset, <=, start);
2619 *offset = MIN(*offset + (1ULL << span) - 1, start);
2620 } else if (*offset < start) {
2621 *offset = start;
2622 }
2623 if (i < 0 || i >= epb)
2624 error = SET_ERROR(ESRCH);
2625 }
2626
2627 if (db != NULL) {
2628 rw_exit(&db->db_rwlock);
2629 dbuf_rele(db, FTAG);
2630 }
2631
2632 return (error);
2633 }
2634
2635 /*
2636 * Find the next hole, data, or sparse region at or after *offset.
2637 * The value 'blkfill' tells us how many items we expect to find
2638 * in an L0 data block; this value is 1 for normal objects,
2639 * DNODES_PER_BLOCK for the meta dnode, and some fraction of
2640 * DNODES_PER_BLOCK when searching for sparse regions thereof.
2641 *
2642 * Examples:
2643 *
2644 * dnode_next_offset(dn, flags, offset, 1, 1, 0);
2645 * Finds the next/previous hole/data in a file.
2646 * Used in dmu_offset_next().
2647 *
2648 * dnode_next_offset(mdn, flags, offset, 0, DNODES_PER_BLOCK, txg);
2649 * Finds the next free/allocated dnode an objset's meta-dnode.
2650 * Only finds objects that have new contents since txg (ie.
2651 * bonus buffer changes and content removal are ignored).
2652 * Used in dmu_object_next().
2653 *
2654 * dnode_next_offset(mdn, DNODE_FIND_HOLE, offset, 2, DNODES_PER_BLOCK >> 2, 0);
2655 * Finds the next L2 meta-dnode bp that's at most 1/4 full.
2656 * Used in dmu_object_alloc().
2657 */
2658 int
dnode_next_offset(dnode_t * dn,int flags,uint64_t * offset,int minlvl,uint64_t blkfill,uint64_t txg)2659 dnode_next_offset(dnode_t *dn, int flags, uint64_t *offset,
2660 int minlvl, uint64_t blkfill, uint64_t txg)
2661 {
2662 uint64_t initial_offset = *offset;
2663 int lvl, maxlvl;
2664 int error = 0;
2665
2666 if (!(flags & DNODE_FIND_HAVELOCK))
2667 rw_enter(&dn->dn_struct_rwlock, RW_READER);
2668
2669 if (dn->dn_phys->dn_nlevels == 0) {
2670 error = SET_ERROR(ESRCH);
2671 goto out;
2672 }
2673
2674 if (dn->dn_datablkshift == 0) {
2675 if (*offset < dn->dn_datablksz) {
2676 if (flags & DNODE_FIND_HOLE)
2677 *offset = dn->dn_datablksz;
2678 } else {
2679 error = SET_ERROR(ESRCH);
2680 }
2681 goto out;
2682 }
2683
2684 maxlvl = dn->dn_phys->dn_nlevels;
2685
2686 for (lvl = minlvl; lvl <= maxlvl; lvl++) {
2687 error = dnode_next_offset_level(dn,
2688 flags, offset, lvl, blkfill, txg);
2689 if (error != ESRCH)
2690 break;
2691 }
2692
2693 while (error == 0 && --lvl >= minlvl) {
2694 error = dnode_next_offset_level(dn,
2695 flags, offset, lvl, blkfill, txg);
2696 }
2697
2698 /*
2699 * There's always a "virtual hole" at the end of the object, even
2700 * if all BP's which physically exist are non-holes.
2701 */
2702 if ((flags & DNODE_FIND_HOLE) && error == ESRCH && txg == 0 &&
2703 minlvl == 1 && blkfill == 1 && !(flags & DNODE_FIND_BACKWARDS)) {
2704 error = 0;
2705 }
2706
2707 if (error == 0 && (flags & DNODE_FIND_BACKWARDS ?
2708 initial_offset < *offset : initial_offset > *offset))
2709 error = SET_ERROR(ESRCH);
2710 out:
2711 if (!(flags & DNODE_FIND_HAVELOCK))
2712 rw_exit(&dn->dn_struct_rwlock);
2713
2714 return (error);
2715 }
2716
2717 #if defined(_KERNEL)
2718 EXPORT_SYMBOL(dnode_hold);
2719 EXPORT_SYMBOL(dnode_rele);
2720 EXPORT_SYMBOL(dnode_set_nlevels);
2721 EXPORT_SYMBOL(dnode_set_blksz);
2722 EXPORT_SYMBOL(dnode_free_range);
2723 EXPORT_SYMBOL(dnode_evict_dbufs);
2724 EXPORT_SYMBOL(dnode_evict_bonus);
2725 #endif
2726
2727 ZFS_MODULE_PARAM(zfs, zfs_, default_bs, INT, ZMOD_RW,
2728 "Default dnode block shift");
2729 ZFS_MODULE_PARAM(zfs, zfs_, default_ibs, INT, ZMOD_RW,
2730 "Default dnode indirect block shift");
2731