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FreeBSD: Parameterize ZFS_ENTER/ZFS_VERIFY_VP with an error code
[zfs.git] / module / zfs / dnode.c
blobaf0ee1b0f8b168f8fe3fc2ae022675e569f88dbe
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 static kstat_t *dnode_ksp;
75 static kmem_cache_t *dnode_cache;
76
77 static dnode_phys_t dnode_phys_zero __maybe_unused;
78
79 int zfs_default_bs = SPA_MINBLOCKSHIFT;
80 int zfs_default_ibs = DN_MAX_INDBLKSHIFT;
81
82 #ifdef _KERNEL
83 static kmem_cbrc_t dnode_move(void *, void *, size_t, void *);
84 #endif /* _KERNEL */
85
86 static int
87 dbuf_compare(const void *x1, const void *x2)
88 {
89 const dmu_buf_impl_t *d1 = x1;
90 const dmu_buf_impl_t *d2 = x2;
91
92 int cmp = TREE_CMP(d1->db_level, d2->db_level);
93 if (likely(cmp))
94 return (cmp);
95
96 cmp = TREE_CMP(d1->db_blkid, d2->db_blkid);
97 if (likely(cmp))
98 return (cmp);
99
100 if (d1->db_state == DB_SEARCH) {
101 ASSERT3S(d2->db_state, !=, DB_SEARCH);
102 return (-1);
103 } else if (d2->db_state == DB_SEARCH) {
104 ASSERT3S(d1->db_state, !=, DB_SEARCH);
105 return (1);
106 }
107
108 return (TREE_PCMP(d1, d2));
109 }
110
111 static int
112 dnode_cons(void *arg, void *unused, int kmflag)
113 {
114 (void) unused, (void) kmflag;
115 dnode_t *dn = arg;
116
117 rw_init(&dn->dn_struct_rwlock, NULL, RW_NOLOCKDEP, NULL);
118 mutex_init(&dn->dn_mtx, NULL, MUTEX_DEFAULT, NULL);
119 mutex_init(&dn->dn_dbufs_mtx, NULL, MUTEX_DEFAULT, NULL);
120 cv_init(&dn->dn_notxholds, NULL, CV_DEFAULT, NULL);
121 cv_init(&dn->dn_nodnholds, NULL, CV_DEFAULT, NULL);
122
123 /*
124 * Every dbuf has a reference, and dropping a tracked reference is
125 * O(number of references), so don't track dn_holds.
126 */
127 zfs_refcount_create_untracked(&dn->dn_holds);
128 zfs_refcount_create(&dn->dn_tx_holds);
129 list_link_init(&dn->dn_link);
130
131 memset(dn->dn_next_type, 0, sizeof (dn->dn_next_type));
132 memset(dn->dn_next_nblkptr, 0, sizeof (dn->dn_next_nblkptr));
133 memset(dn->dn_next_nlevels, 0, sizeof (dn->dn_next_nlevels));
134 memset(dn->dn_next_indblkshift, 0, sizeof (dn->dn_next_indblkshift));
135 memset(dn->dn_next_bonustype, 0, sizeof (dn->dn_next_bonustype));
136 memset(dn->dn_rm_spillblk, 0, sizeof (dn->dn_rm_spillblk));
137 memset(dn->dn_next_bonuslen, 0, sizeof (dn->dn_next_bonuslen));
138 memset(dn->dn_next_blksz, 0, sizeof (dn->dn_next_blksz));
139 memset(dn->dn_next_maxblkid, 0, sizeof (dn->dn_next_maxblkid));
140
141 for (int i = 0; i < TXG_SIZE; i++) {
142 multilist_link_init(&dn->dn_dirty_link[i]);
143 dn->dn_free_ranges[i] = NULL;
144 list_create(&dn->dn_dirty_records[i],
145 sizeof (dbuf_dirty_record_t),
146 offsetof(dbuf_dirty_record_t, dr_dirty_node));
147 }
148
149 dn->dn_allocated_txg = 0;
150 dn->dn_free_txg = 0;
151 dn->dn_assigned_txg = 0;
152 dn->dn_dirty_txg = 0;
153 dn->dn_dirtyctx = 0;
154 dn->dn_dirtyctx_firstset = NULL;
155 dn->dn_bonus = NULL;
156 dn->dn_have_spill = B_FALSE;
157 dn->dn_zio = NULL;
158 dn->dn_oldused = 0;
159 dn->dn_oldflags = 0;
160 dn->dn_olduid = 0;
161 dn->dn_oldgid = 0;
162 dn->dn_oldprojid = ZFS_DEFAULT_PROJID;
163 dn->dn_newuid = 0;
164 dn->dn_newgid = 0;
165 dn->dn_newprojid = ZFS_DEFAULT_PROJID;
166 dn->dn_id_flags = 0;
167
168 dn->dn_dbufs_count = 0;
169 avl_create(&dn->dn_dbufs, dbuf_compare, sizeof (dmu_buf_impl_t),
170 offsetof(dmu_buf_impl_t, db_link));
171
172 dn->dn_moved = 0;
173 return (0);
174 }
175
176 static void
177 dnode_dest(void *arg, void *unused)
178 {
179 (void) unused;
180 dnode_t *dn = arg;
181
182 rw_destroy(&dn->dn_struct_rwlock);
183 mutex_destroy(&dn->dn_mtx);
184 mutex_destroy(&dn->dn_dbufs_mtx);
185 cv_destroy(&dn->dn_notxholds);
186 cv_destroy(&dn->dn_nodnholds);
187 zfs_refcount_destroy(&dn->dn_holds);
188 zfs_refcount_destroy(&dn->dn_tx_holds);
189 ASSERT(!list_link_active(&dn->dn_link));
190
191 for (int i = 0; i < TXG_SIZE; i++) {
192 ASSERT(!multilist_link_active(&dn->dn_dirty_link[i]));
193 ASSERT3P(dn->dn_free_ranges[i], ==, NULL);
194 list_destroy(&dn->dn_dirty_records[i]);
195 ASSERT0(dn->dn_next_nblkptr[i]);
196 ASSERT0(dn->dn_next_nlevels[i]);
197 ASSERT0(dn->dn_next_indblkshift[i]);
198 ASSERT0(dn->dn_next_bonustype[i]);
199 ASSERT0(dn->dn_rm_spillblk[i]);
200 ASSERT0(dn->dn_next_bonuslen[i]);
201 ASSERT0(dn->dn_next_blksz[i]);
202 ASSERT0(dn->dn_next_maxblkid[i]);
203 }
204
205 ASSERT0(dn->dn_allocated_txg);
206 ASSERT0(dn->dn_free_txg);
207 ASSERT0(dn->dn_assigned_txg);
208 ASSERT0(dn->dn_dirty_txg);
209 ASSERT0(dn->dn_dirtyctx);
210 ASSERT3P(dn->dn_dirtyctx_firstset, ==, NULL);
211 ASSERT3P(dn->dn_bonus, ==, NULL);
212 ASSERT(!dn->dn_have_spill);
213 ASSERT3P(dn->dn_zio, ==, NULL);
214 ASSERT0(dn->dn_oldused);
215 ASSERT0(dn->dn_oldflags);
216 ASSERT0(dn->dn_olduid);
217 ASSERT0(dn->dn_oldgid);
218 ASSERT0(dn->dn_oldprojid);
219 ASSERT0(dn->dn_newuid);
220 ASSERT0(dn->dn_newgid);
221 ASSERT0(dn->dn_newprojid);
222 ASSERT0(dn->dn_id_flags);
223
224 ASSERT0(dn->dn_dbufs_count);
225 avl_destroy(&dn->dn_dbufs);
226 }
227
228 void
229 dnode_init(void)
230 {
231 ASSERT(dnode_cache == NULL);
232 dnode_cache = kmem_cache_create("dnode_t", sizeof (dnode_t),
233 0, dnode_cons, dnode_dest, NULL, NULL, NULL, 0);
234 kmem_cache_set_move(dnode_cache, dnode_move);
235
236 dnode_ksp = kstat_create("zfs", 0, "dnodestats", "misc",
237 KSTAT_TYPE_NAMED, sizeof (dnode_stats) / sizeof (kstat_named_t),
238 KSTAT_FLAG_VIRTUAL);
239 if (dnode_ksp != NULL) {
240 dnode_ksp->ks_data = &dnode_stats;
241 kstat_install(dnode_ksp);
242 }
243 }
244
245 void
246 dnode_fini(void)
247 {
248 if (dnode_ksp != NULL) {
249 kstat_delete(dnode_ksp);
250 dnode_ksp = NULL;
251 }
252
253 kmem_cache_destroy(dnode_cache);
254 dnode_cache = NULL;
255 }
256
257
258 #ifdef ZFS_DEBUG
259 void
260 dnode_verify(dnode_t *dn)
261 {
262 int drop_struct_lock = FALSE;
263
264 ASSERT(dn->dn_phys);
265 ASSERT(dn->dn_objset);
266 ASSERT(dn->dn_handle->dnh_dnode == dn);
267
268 ASSERT(DMU_OT_IS_VALID(dn->dn_phys->dn_type));
269
270 if (!(zfs_flags & ZFS_DEBUG_DNODE_VERIFY))
271 return;
272
273 if (!RW_WRITE_HELD(&dn->dn_struct_rwlock)) {
274 rw_enter(&dn->dn_struct_rwlock, RW_READER);
275 drop_struct_lock = TRUE;
276 }
277 if (dn->dn_phys->dn_type != DMU_OT_NONE || dn->dn_allocated_txg != 0) {
278 int i;
279 int max_bonuslen = DN_SLOTS_TO_BONUSLEN(dn->dn_num_slots);
280 ASSERT3U(dn->dn_indblkshift, <=, SPA_MAXBLOCKSHIFT);
281 if (dn->dn_datablkshift) {
282 ASSERT3U(dn->dn_datablkshift, >=, SPA_MINBLOCKSHIFT);
283 ASSERT3U(dn->dn_datablkshift, <=, SPA_MAXBLOCKSHIFT);
284 ASSERT3U(1<<dn->dn_datablkshift, ==, dn->dn_datablksz);
285 }
286 ASSERT3U(dn->dn_nlevels, <=, 30);
287 ASSERT(DMU_OT_IS_VALID(dn->dn_type));
288 ASSERT3U(dn->dn_nblkptr, >=, 1);
289 ASSERT3U(dn->dn_nblkptr, <=, DN_MAX_NBLKPTR);
290 ASSERT3U(dn->dn_bonuslen, <=, max_bonuslen);
291 ASSERT3U(dn->dn_datablksz, ==,
292 dn->dn_datablkszsec << SPA_MINBLOCKSHIFT);
293 ASSERT3U(ISP2(dn->dn_datablksz), ==, dn->dn_datablkshift != 0);
294 ASSERT3U((dn->dn_nblkptr - 1) * sizeof (blkptr_t) +
295 dn->dn_bonuslen, <=, max_bonuslen);
296 for (i = 0; i < TXG_SIZE; i++) {
297 ASSERT3U(dn->dn_next_nlevels[i], <=, dn->dn_nlevels);
298 }
299 }
300 if (dn->dn_phys->dn_type != DMU_OT_NONE)
301 ASSERT3U(dn->dn_phys->dn_nlevels, <=, dn->dn_nlevels);
302 ASSERT(DMU_OBJECT_IS_SPECIAL(dn->dn_object) || dn->dn_dbuf != NULL);
303 if (dn->dn_dbuf != NULL) {
304 ASSERT3P(dn->dn_phys, ==,
305 (dnode_phys_t *)dn->dn_dbuf->db.db_data +
306 (dn->dn_object % (dn->dn_dbuf->db.db_size >> DNODE_SHIFT)));
307 }
308 if (drop_struct_lock)
309 rw_exit(&dn->dn_struct_rwlock);
310 }
311 #endif
312
313 void
314 dnode_byteswap(dnode_phys_t *dnp)
315 {
316 uint64_t *buf64 = (void*)&dnp->dn_blkptr;
317 int i;
318
319 if (dnp->dn_type == DMU_OT_NONE) {
320 memset(dnp, 0, sizeof (dnode_phys_t));
321 return;
322 }
323
324 dnp->dn_datablkszsec = BSWAP_16(dnp->dn_datablkszsec);
325 dnp->dn_bonuslen = BSWAP_16(dnp->dn_bonuslen);
326 dnp->dn_extra_slots = BSWAP_8(dnp->dn_extra_slots);
327 dnp->dn_maxblkid = BSWAP_64(dnp->dn_maxblkid);
328 dnp->dn_used = BSWAP_64(dnp->dn_used);
329
330 /*
331 * dn_nblkptr is only one byte, so it's OK to read it in either
332 * byte order. We can't read dn_bouslen.
333 */
334 ASSERT(dnp->dn_indblkshift <= SPA_MAXBLOCKSHIFT);
335 ASSERT(dnp->dn_nblkptr <= DN_MAX_NBLKPTR);
336 for (i = 0; i < dnp->dn_nblkptr * sizeof (blkptr_t)/8; i++)
337 buf64[i] = BSWAP_64(buf64[i]);
338
339 /*
340 * OK to check dn_bonuslen for zero, because it won't matter if
341 * we have the wrong byte order. This is necessary because the
342 * dnode dnode is smaller than a regular dnode.
343 */
344 if (dnp->dn_bonuslen != 0) {
345 /*
346 * Note that the bonus length calculated here may be
347 * longer than the actual bonus buffer. This is because
348 * we always put the bonus buffer after the last block
349 * pointer (instead of packing it against the end of the
350 * dnode buffer).
351 */
352 int off = (dnp->dn_nblkptr-1) * sizeof (blkptr_t);
353 int slots = dnp->dn_extra_slots + 1;
354 size_t len = DN_SLOTS_TO_BONUSLEN(slots) - off;
355 dmu_object_byteswap_t byteswap;
356 ASSERT(DMU_OT_IS_VALID(dnp->dn_bonustype));
357 byteswap = DMU_OT_BYTESWAP(dnp->dn_bonustype);
358 dmu_ot_byteswap[byteswap].ob_func(dnp->dn_bonus + off, len);
359 }
360
361 /* Swap SPILL block if we have one */
362 if (dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR)
363 byteswap_uint64_array(DN_SPILL_BLKPTR(dnp), sizeof (blkptr_t));
364 }
365
366 void
367 dnode_buf_byteswap(void *vbuf, size_t size)
368 {
369 int i = 0;
370
371 ASSERT3U(sizeof (dnode_phys_t), ==, (1<<DNODE_SHIFT));
372 ASSERT((size & (sizeof (dnode_phys_t)-1)) == 0);
373
374 while (i < size) {
375 dnode_phys_t *dnp = (void *)(((char *)vbuf) + i);
376 dnode_byteswap(dnp);
377
378 i += DNODE_MIN_SIZE;
379 if (dnp->dn_type != DMU_OT_NONE)
380 i += dnp->dn_extra_slots * DNODE_MIN_SIZE;
381 }
382 }
383
384 void
385 dnode_setbonuslen(dnode_t *dn, int newsize, dmu_tx_t *tx)
386 {
387 ASSERT3U(zfs_refcount_count(&dn->dn_holds), >=, 1);
388
389 dnode_setdirty(dn, tx);
390 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
391 ASSERT3U(newsize, <=, DN_SLOTS_TO_BONUSLEN(dn->dn_num_slots) -
392 (dn->dn_nblkptr-1) * sizeof (blkptr_t));
393
394 if (newsize < dn->dn_bonuslen) {
395 /* clear any data after the end of the new size */
396 size_t diff = dn->dn_bonuslen - newsize;
397 char *data_end = ((char *)dn->dn_bonus->db.db_data) + newsize;
398 memset(data_end, 0, diff);
399 }
400
401 dn->dn_bonuslen = newsize;
402 if (newsize == 0)
403 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = DN_ZERO_BONUSLEN;
404 else
405 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = dn->dn_bonuslen;
406 rw_exit(&dn->dn_struct_rwlock);
407 }
408
409 void
410 dnode_setbonus_type(dnode_t *dn, dmu_object_type_t newtype, dmu_tx_t *tx)
411 {
412 ASSERT3U(zfs_refcount_count(&dn->dn_holds), >=, 1);
413 dnode_setdirty(dn, tx);
414 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
415 dn->dn_bonustype = newtype;
416 dn->dn_next_bonustype[tx->tx_txg & TXG_MASK] = dn->dn_bonustype;
417 rw_exit(&dn->dn_struct_rwlock);
418 }
419
420 void
421 dnode_rm_spill(dnode_t *dn, dmu_tx_t *tx)
422 {
423 ASSERT3U(zfs_refcount_count(&dn->dn_holds), >=, 1);
424 ASSERT(RW_WRITE_HELD(&dn->dn_struct_rwlock));
425 dnode_setdirty(dn, tx);
426 dn->dn_rm_spillblk[tx->tx_txg & TXG_MASK] = DN_KILL_SPILLBLK;
427 dn->dn_have_spill = B_FALSE;
428 }
429
430 static void
431 dnode_setdblksz(dnode_t *dn, int size)
432 {
433 ASSERT0(P2PHASE(size, SPA_MINBLOCKSIZE));
434 ASSERT3U(size, <=, SPA_MAXBLOCKSIZE);
435 ASSERT3U(size, >=, SPA_MINBLOCKSIZE);
436 ASSERT3U(size >> SPA_MINBLOCKSHIFT, <,
437 1<<(sizeof (dn->dn_phys->dn_datablkszsec) * 8));
438 dn->dn_datablksz = size;
439 dn->dn_datablkszsec = size >> SPA_MINBLOCKSHIFT;
440 dn->dn_datablkshift = ISP2(size) ? highbit64(size - 1) : 0;
441 }
442
443 static dnode_t *
444 dnode_create(objset_t *os, dnode_phys_t *dnp, dmu_buf_impl_t *db,
445 uint64_t object, dnode_handle_t *dnh)
446 {
447 dnode_t *dn;
448
449 dn = kmem_cache_alloc(dnode_cache, KM_SLEEP);
450 dn->dn_moved = 0;
451
452 /*
453 * Defer setting dn_objset until the dnode is ready to be a candidate
454 * for the dnode_move() callback.
455 */
456 dn->dn_object = object;
457 dn->dn_dbuf = db;
458 dn->dn_handle = dnh;
459 dn->dn_phys = dnp;
460
461 if (dnp->dn_datablkszsec) {
462 dnode_setdblksz(dn, dnp->dn_datablkszsec << SPA_MINBLOCKSHIFT);
463 } else {
464 dn->dn_datablksz = 0;
465 dn->dn_datablkszsec = 0;
466 dn->dn_datablkshift = 0;
467 }
468 dn->dn_indblkshift = dnp->dn_indblkshift;
469 dn->dn_nlevels = dnp->dn_nlevels;
470 dn->dn_type = dnp->dn_type;
471 dn->dn_nblkptr = dnp->dn_nblkptr;
472 dn->dn_checksum = dnp->dn_checksum;
473 dn->dn_compress = dnp->dn_compress;
474 dn->dn_bonustype = dnp->dn_bonustype;
475 dn->dn_bonuslen = dnp->dn_bonuslen;
476 dn->dn_num_slots = dnp->dn_extra_slots + 1;
477 dn->dn_maxblkid = dnp->dn_maxblkid;
478 dn->dn_have_spill = ((dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) != 0);
479 dn->dn_id_flags = 0;
480
481 dmu_zfetch_init(&dn->dn_zfetch, dn);
482
483 ASSERT(DMU_OT_IS_VALID(dn->dn_phys->dn_type));
484 ASSERT(zrl_is_locked(&dnh->dnh_zrlock));
485 ASSERT(!DN_SLOT_IS_PTR(dnh->dnh_dnode));
486
487 mutex_enter(&os->os_lock);
488
489 /*
490 * Exclude special dnodes from os_dnodes so an empty os_dnodes
491 * signifies that the special dnodes have no references from
492 * their children (the entries in os_dnodes). This allows
493 * dnode_destroy() to easily determine if the last child has
494 * been removed and then complete eviction of the objset.
495 */
496 if (!DMU_OBJECT_IS_SPECIAL(object))
497 list_insert_head(&os->os_dnodes, dn);
498 membar_producer();
499
500 /*
501 * Everything else must be valid before assigning dn_objset
502 * makes the dnode eligible for dnode_move().
503 */
504 dn->dn_objset = os;
505
506 dnh->dnh_dnode = dn;
507 mutex_exit(&os->os_lock);
508
509 arc_space_consume(sizeof (dnode_t), ARC_SPACE_DNODE);
510
511 return (dn);
512 }
513
514 /*
515 * Caller must be holding the dnode handle, which is released upon return.
516 */
517 static void
518 dnode_destroy(dnode_t *dn)
519 {
520 objset_t *os = dn->dn_objset;
521 boolean_t complete_os_eviction = B_FALSE;
522
523 ASSERT((dn->dn_id_flags & DN_ID_NEW_EXIST) == 0);
524
525 mutex_enter(&os->os_lock);
526 POINTER_INVALIDATE(&dn->dn_objset);
527 if (!DMU_OBJECT_IS_SPECIAL(dn->dn_object)) {
528 list_remove(&os->os_dnodes, dn);
529 complete_os_eviction =
530 list_is_empty(&os->os_dnodes) &&
531 list_link_active(&os->os_evicting_node);
532 }
533 mutex_exit(&os->os_lock);
534
535 /* the dnode can no longer move, so we can release the handle */
536 if (!zrl_is_locked(&dn->dn_handle->dnh_zrlock))
537 zrl_remove(&dn->dn_handle->dnh_zrlock);
538
539 dn->dn_allocated_txg = 0;
540 dn->dn_free_txg = 0;
541 dn->dn_assigned_txg = 0;
542 dn->dn_dirty_txg = 0;
543
544 dn->dn_dirtyctx = 0;
545 dn->dn_dirtyctx_firstset = NULL;
546 if (dn->dn_bonus != NULL) {
547 mutex_enter(&dn->dn_bonus->db_mtx);
548 dbuf_destroy(dn->dn_bonus);
549 dn->dn_bonus = NULL;
550 }
551 dn->dn_zio = NULL;
552
553 dn->dn_have_spill = B_FALSE;
554 dn->dn_oldused = 0;
555 dn->dn_oldflags = 0;
556 dn->dn_olduid = 0;
557 dn->dn_oldgid = 0;
558 dn->dn_oldprojid = ZFS_DEFAULT_PROJID;
559 dn->dn_newuid = 0;
560 dn->dn_newgid = 0;
561 dn->dn_newprojid = ZFS_DEFAULT_PROJID;
562 dn->dn_id_flags = 0;
563
564 dmu_zfetch_fini(&dn->dn_zfetch);
565 kmem_cache_free(dnode_cache, dn);
566 arc_space_return(sizeof (dnode_t), ARC_SPACE_DNODE);
567
568 if (complete_os_eviction)
569 dmu_objset_evict_done(os);
570 }
571
572 void
573 dnode_allocate(dnode_t *dn, dmu_object_type_t ot, int blocksize, int ibs,
574 dmu_object_type_t bonustype, int bonuslen, int dn_slots, dmu_tx_t *tx)
575 {
576 int i;
577
578 ASSERT3U(dn_slots, >, 0);
579 ASSERT3U(dn_slots << DNODE_SHIFT, <=,
580 spa_maxdnodesize(dmu_objset_spa(dn->dn_objset)));
581 ASSERT3U(blocksize, <=,
582 spa_maxblocksize(dmu_objset_spa(dn->dn_objset)));
583 if (blocksize == 0)
584 blocksize = 1 << zfs_default_bs;
585 else
586 blocksize = P2ROUNDUP(blocksize, SPA_MINBLOCKSIZE);
587
588 if (ibs == 0)
589 ibs = zfs_default_ibs;
590
591 ibs = MIN(MAX(ibs, DN_MIN_INDBLKSHIFT), DN_MAX_INDBLKSHIFT);
592
593 dprintf("os=%p obj=%llu txg=%llu blocksize=%d ibs=%d dn_slots=%d\n",
594 dn->dn_objset, (u_longlong_t)dn->dn_object,
595 (u_longlong_t)tx->tx_txg, blocksize, ibs, dn_slots);
596 DNODE_STAT_BUMP(dnode_allocate);
597
598 ASSERT(dn->dn_type == DMU_OT_NONE);
599 ASSERT0(memcmp(dn->dn_phys, &dnode_phys_zero, sizeof (dnode_phys_t)));
600 ASSERT(dn->dn_phys->dn_type == DMU_OT_NONE);
601 ASSERT(ot != DMU_OT_NONE);
602 ASSERT(DMU_OT_IS_VALID(ot));
603 ASSERT((bonustype == DMU_OT_NONE && bonuslen == 0) ||
604 (bonustype == DMU_OT_SA && bonuslen == 0) ||
605 (bonustype != DMU_OT_NONE && bonuslen != 0));
606 ASSERT(DMU_OT_IS_VALID(bonustype));
607 ASSERT3U(bonuslen, <=, DN_SLOTS_TO_BONUSLEN(dn_slots));
608 ASSERT(dn->dn_type == DMU_OT_NONE);
609 ASSERT0(dn->dn_maxblkid);
610 ASSERT0(dn->dn_allocated_txg);
611 ASSERT0(dn->dn_assigned_txg);
612 ASSERT(zfs_refcount_is_zero(&dn->dn_tx_holds));
613 ASSERT3U(zfs_refcount_count(&dn->dn_holds), <=, 1);
614 ASSERT(avl_is_empty(&dn->dn_dbufs));
615
616 for (i = 0; i < TXG_SIZE; i++) {
617 ASSERT0(dn->dn_next_nblkptr[i]);
618 ASSERT0(dn->dn_next_nlevels[i]);
619 ASSERT0(dn->dn_next_indblkshift[i]);
620 ASSERT0(dn->dn_next_bonuslen[i]);
621 ASSERT0(dn->dn_next_bonustype[i]);
622 ASSERT0(dn->dn_rm_spillblk[i]);
623 ASSERT0(dn->dn_next_blksz[i]);
624 ASSERT0(dn->dn_next_maxblkid[i]);
625 ASSERT(!multilist_link_active(&dn->dn_dirty_link[i]));
626 ASSERT3P(list_head(&dn->dn_dirty_records[i]), ==, NULL);
627 ASSERT3P(dn->dn_free_ranges[i], ==, NULL);
628 }
629
630 dn->dn_type = ot;
631 dnode_setdblksz(dn, blocksize);
632 dn->dn_indblkshift = ibs;
633 dn->dn_nlevels = 1;
634 dn->dn_num_slots = dn_slots;
635 if (bonustype == DMU_OT_SA) /* Maximize bonus space for SA */
636 dn->dn_nblkptr = 1;
637 else {
638 dn->dn_nblkptr = MIN(DN_MAX_NBLKPTR,
639 1 + ((DN_SLOTS_TO_BONUSLEN(dn_slots) - bonuslen) >>
640 SPA_BLKPTRSHIFT));
641 }
642
643 dn->dn_bonustype = bonustype;
644 dn->dn_bonuslen = bonuslen;
645 dn->dn_checksum = ZIO_CHECKSUM_INHERIT;
646 dn->dn_compress = ZIO_COMPRESS_INHERIT;
647 dn->dn_dirtyctx = 0;
648
649 dn->dn_free_txg = 0;
650 dn->dn_dirtyctx_firstset = NULL;
651 dn->dn_dirty_txg = 0;
652
653 dn->dn_allocated_txg = tx->tx_txg;
654 dn->dn_id_flags = 0;
655
656 dnode_setdirty(dn, tx);
657 dn->dn_next_indblkshift[tx->tx_txg & TXG_MASK] = ibs;
658 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = dn->dn_bonuslen;
659 dn->dn_next_bonustype[tx->tx_txg & TXG_MASK] = dn->dn_bonustype;
660 dn->dn_next_blksz[tx->tx_txg & TXG_MASK] = dn->dn_datablksz;
661 }
662
663 void
664 dnode_reallocate(dnode_t *dn, dmu_object_type_t ot, int blocksize,
665 dmu_object_type_t bonustype, int bonuslen, int dn_slots,
666 boolean_t keep_spill, dmu_tx_t *tx)
667 {
668 int nblkptr;
669
670 ASSERT3U(blocksize, >=, SPA_MINBLOCKSIZE);
671 ASSERT3U(blocksize, <=,
672 spa_maxblocksize(dmu_objset_spa(dn->dn_objset)));
673 ASSERT0(blocksize % SPA_MINBLOCKSIZE);
674 ASSERT(dn->dn_object != DMU_META_DNODE_OBJECT || dmu_tx_private_ok(tx));
675 ASSERT(tx->tx_txg != 0);
676 ASSERT((bonustype == DMU_OT_NONE && bonuslen == 0) ||
677 (bonustype != DMU_OT_NONE && bonuslen != 0) ||
678 (bonustype == DMU_OT_SA && bonuslen == 0));
679 ASSERT(DMU_OT_IS_VALID(bonustype));
680 ASSERT3U(bonuslen, <=,
681 DN_BONUS_SIZE(spa_maxdnodesize(dmu_objset_spa(dn->dn_objset))));
682 ASSERT3U(bonuslen, <=, DN_BONUS_SIZE(dn_slots << DNODE_SHIFT));
683
684 dnode_free_interior_slots(dn);
685 DNODE_STAT_BUMP(dnode_reallocate);
686
687 /* clean up any unreferenced dbufs */
688 dnode_evict_dbufs(dn);
689
690 dn->dn_id_flags = 0;
691
692 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
693 dnode_setdirty(dn, tx);
694 if (dn->dn_datablksz != blocksize) {
695 /* change blocksize */
696 ASSERT0(dn->dn_maxblkid);
697 ASSERT(BP_IS_HOLE(&dn->dn_phys->dn_blkptr[0]) ||
698 dnode_block_freed(dn, 0));
699
700 dnode_setdblksz(dn, blocksize);
701 dn->dn_next_blksz[tx->tx_txg & TXG_MASK] = blocksize;
702 }
703 if (dn->dn_bonuslen != bonuslen)
704 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = bonuslen;
705
706 if (bonustype == DMU_OT_SA) /* Maximize bonus space for SA */
707 nblkptr = 1;
708 else
709 nblkptr = MIN(DN_MAX_NBLKPTR,
710 1 + ((DN_SLOTS_TO_BONUSLEN(dn_slots) - bonuslen) >>
711 SPA_BLKPTRSHIFT));
712 if (dn->dn_bonustype != bonustype)
713 dn->dn_next_bonustype[tx->tx_txg & TXG_MASK] = bonustype;
714 if (dn->dn_nblkptr != nblkptr)
715 dn->dn_next_nblkptr[tx->tx_txg & TXG_MASK] = nblkptr;
716 if (dn->dn_phys->dn_flags & DNODE_FLAG_SPILL_BLKPTR && !keep_spill) {
717 dbuf_rm_spill(dn, tx);
718 dnode_rm_spill(dn, tx);
719 }
720
721 rw_exit(&dn->dn_struct_rwlock);
722
723 /* change type */
724 dn->dn_type = ot;
725
726 /* change bonus size and type */
727 mutex_enter(&dn->dn_mtx);
728 dn->dn_bonustype = bonustype;
729 dn->dn_bonuslen = bonuslen;
730 dn->dn_num_slots = dn_slots;
731 dn->dn_nblkptr = nblkptr;
732 dn->dn_checksum = ZIO_CHECKSUM_INHERIT;
733 dn->dn_compress = ZIO_COMPRESS_INHERIT;
734 ASSERT3U(dn->dn_nblkptr, <=, DN_MAX_NBLKPTR);
735
736 /* fix up the bonus db_size */
737 if (dn->dn_bonus) {
738 dn->dn_bonus->db.db_size =
739 DN_SLOTS_TO_BONUSLEN(dn->dn_num_slots) -
740 (dn->dn_nblkptr-1) * sizeof (blkptr_t);
741 ASSERT(dn->dn_bonuslen <= dn->dn_bonus->db.db_size);
742 }
743
744 dn->dn_allocated_txg = tx->tx_txg;
745 mutex_exit(&dn->dn_mtx);
746 }
747
748 #ifdef _KERNEL
749 static void
750 dnode_move_impl(dnode_t *odn, dnode_t *ndn)
751 {
752 ASSERT(!RW_LOCK_HELD(&odn->dn_struct_rwlock));
753 ASSERT(MUTEX_NOT_HELD(&odn->dn_mtx));
754 ASSERT(MUTEX_NOT_HELD(&odn->dn_dbufs_mtx));
755
756 /* Copy fields. */
757 ndn->dn_objset = odn->dn_objset;
758 ndn->dn_object = odn->dn_object;
759 ndn->dn_dbuf = odn->dn_dbuf;
760 ndn->dn_handle = odn->dn_handle;
761 ndn->dn_phys = odn->dn_phys;
762 ndn->dn_type = odn->dn_type;
763 ndn->dn_bonuslen = odn->dn_bonuslen;
764 ndn->dn_bonustype = odn->dn_bonustype;
765 ndn->dn_nblkptr = odn->dn_nblkptr;
766 ndn->dn_checksum = odn->dn_checksum;
767 ndn->dn_compress = odn->dn_compress;
768 ndn->dn_nlevels = odn->dn_nlevels;
769 ndn->dn_indblkshift = odn->dn_indblkshift;
770 ndn->dn_datablkshift = odn->dn_datablkshift;
771 ndn->dn_datablkszsec = odn->dn_datablkszsec;
772 ndn->dn_datablksz = odn->dn_datablksz;
773 ndn->dn_maxblkid = odn->dn_maxblkid;
774 ndn->dn_num_slots = odn->dn_num_slots;
775 memcpy(ndn->dn_next_type, odn->dn_next_type,
776 sizeof (odn->dn_next_type));
777 memcpy(ndn->dn_next_nblkptr, odn->dn_next_nblkptr,
778 sizeof (odn->dn_next_nblkptr));
779 memcpy(ndn->dn_next_nlevels, odn->dn_next_nlevels,
780 sizeof (odn->dn_next_nlevels));
781 memcpy(ndn->dn_next_indblkshift, odn->dn_next_indblkshift,
782 sizeof (odn->dn_next_indblkshift));
783 memcpy(ndn->dn_next_bonustype, odn->dn_next_bonustype,
784 sizeof (odn->dn_next_bonustype));
785 memcpy(ndn->dn_rm_spillblk, odn->dn_rm_spillblk,
786 sizeof (odn->dn_rm_spillblk));
787 memcpy(ndn->dn_next_bonuslen, odn->dn_next_bonuslen,
788 sizeof (odn->dn_next_bonuslen));
789 memcpy(ndn->dn_next_blksz, odn->dn_next_blksz,
790 sizeof (odn->dn_next_blksz));
791 memcpy(ndn->dn_next_maxblkid, odn->dn_next_maxblkid,
792 sizeof (odn->dn_next_maxblkid));
793 for (int i = 0; i < TXG_SIZE; i++) {
794 list_move_tail(&ndn->dn_dirty_records[i],
795 &odn->dn_dirty_records[i]);
796 }
797 memcpy(ndn->dn_free_ranges, odn->dn_free_ranges,
798 sizeof (odn->dn_free_ranges));
799 ndn->dn_allocated_txg = odn->dn_allocated_txg;
800 ndn->dn_free_txg = odn->dn_free_txg;
801 ndn->dn_assigned_txg = odn->dn_assigned_txg;
802 ndn->dn_dirty_txg = odn->dn_dirty_txg;
803 ndn->dn_dirtyctx = odn->dn_dirtyctx;
804 ndn->dn_dirtyctx_firstset = odn->dn_dirtyctx_firstset;
805 ASSERT(zfs_refcount_count(&odn->dn_tx_holds) == 0);
806 zfs_refcount_transfer(&ndn->dn_holds, &odn->dn_holds);
807 ASSERT(avl_is_empty(&ndn->dn_dbufs));
808 avl_swap(&ndn->dn_dbufs, &odn->dn_dbufs);
809 ndn->dn_dbufs_count = odn->dn_dbufs_count;
810 ndn->dn_bonus = odn->dn_bonus;
811 ndn->dn_have_spill = odn->dn_have_spill;
812 ndn->dn_zio = odn->dn_zio;
813 ndn->dn_oldused = odn->dn_oldused;
814 ndn->dn_oldflags = odn->dn_oldflags;
815 ndn->dn_olduid = odn->dn_olduid;
816 ndn->dn_oldgid = odn->dn_oldgid;
817 ndn->dn_oldprojid = odn->dn_oldprojid;
818 ndn->dn_newuid = odn->dn_newuid;
819 ndn->dn_newgid = odn->dn_newgid;
820 ndn->dn_newprojid = odn->dn_newprojid;
821 ndn->dn_id_flags = odn->dn_id_flags;
822 dmu_zfetch_init(&ndn->dn_zfetch, ndn);
823
824 /*
825 * Update back pointers. Updating the handle fixes the back pointer of
826 * every descendant dbuf as well as the bonus dbuf.
827 */
828 ASSERT(ndn->dn_handle->dnh_dnode == odn);
829 ndn->dn_handle->dnh_dnode = ndn;
830
831 /*
832 * Invalidate the original dnode by clearing all of its back pointers.
833 */
834 odn->dn_dbuf = NULL;
835 odn->dn_handle = NULL;
836 avl_create(&odn->dn_dbufs, dbuf_compare, sizeof (dmu_buf_impl_t),
837 offsetof(dmu_buf_impl_t, db_link));
838 odn->dn_dbufs_count = 0;
839 odn->dn_bonus = NULL;
840 dmu_zfetch_fini(&odn->dn_zfetch);
841
842 /*
843 * Set the low bit of the objset pointer to ensure that dnode_move()
844 * recognizes the dnode as invalid in any subsequent callback.
845 */
846 POINTER_INVALIDATE(&odn->dn_objset);
847
848 /*
849 * Satisfy the destructor.
850 */
851 for (int i = 0; i < TXG_SIZE; i++) {
852 list_create(&odn->dn_dirty_records[i],
853 sizeof (dbuf_dirty_record_t),
854 offsetof(dbuf_dirty_record_t, dr_dirty_node));
855 odn->dn_free_ranges[i] = NULL;
856 odn->dn_next_nlevels[i] = 0;
857 odn->dn_next_indblkshift[i] = 0;
858 odn->dn_next_bonustype[i] = 0;
859 odn->dn_rm_spillblk[i] = 0;
860 odn->dn_next_bonuslen[i] = 0;
861 odn->dn_next_blksz[i] = 0;
862 }
863 odn->dn_allocated_txg = 0;
864 odn->dn_free_txg = 0;
865 odn->dn_assigned_txg = 0;
866 odn->dn_dirty_txg = 0;
867 odn->dn_dirtyctx = 0;
868 odn->dn_dirtyctx_firstset = NULL;
869 odn->dn_have_spill = B_FALSE;
870 odn->dn_zio = NULL;
871 odn->dn_oldused = 0;
872 odn->dn_oldflags = 0;
873 odn->dn_olduid = 0;
874 odn->dn_oldgid = 0;
875 odn->dn_oldprojid = ZFS_DEFAULT_PROJID;
876 odn->dn_newuid = 0;
877 odn->dn_newgid = 0;
878 odn->dn_newprojid = ZFS_DEFAULT_PROJID;
879 odn->dn_id_flags = 0;
880
881 /*
882 * Mark the dnode.
883 */
884 ndn->dn_moved = 1;
885 odn->dn_moved = (uint8_t)-1;
886 }
887
888 static kmem_cbrc_t
889 dnode_move(void *buf, void *newbuf, size_t size, void *arg)
890 {
891 dnode_t *odn = buf, *ndn = newbuf;
892 objset_t *os;
893 int64_t refcount;
894 uint32_t dbufs;
895
896 /*
897 * The dnode is on the objset's list of known dnodes if the objset
898 * pointer is valid. We set the low bit of the objset pointer when
899 * freeing the dnode to invalidate it, and the memory patterns written
900 * by kmem (baddcafe and deadbeef) set at least one of the two low bits.
901 * A newly created dnode sets the objset pointer last of all to indicate
902 * that the dnode is known and in a valid state to be moved by this
903 * function.
904 */
905 os = odn->dn_objset;
906 if (!POINTER_IS_VALID(os)) {
907 DNODE_STAT_BUMP(dnode_move_invalid);
908 return (KMEM_CBRC_DONT_KNOW);
909 }
910
911 /*
912 * Ensure that the objset does not go away during the move.
913 */
914 rw_enter(&os_lock, RW_WRITER);
915 if (os != odn->dn_objset) {
916 rw_exit(&os_lock);
917 DNODE_STAT_BUMP(dnode_move_recheck1);
918 return (KMEM_CBRC_DONT_KNOW);
919 }
920
921 /*
922 * If the dnode is still valid, then so is the objset. We know that no
923 * valid objset can be freed while we hold os_lock, so we can safely
924 * ensure that the objset remains in use.
925 */
926 mutex_enter(&os->os_lock);
927
928 /*
929 * Recheck the objset pointer in case the dnode was removed just before
930 * acquiring the lock.
931 */
932 if (os != odn->dn_objset) {
933 mutex_exit(&os->os_lock);
934 rw_exit(&os_lock);
935 DNODE_STAT_BUMP(dnode_move_recheck2);
936 return (KMEM_CBRC_DONT_KNOW);
937 }
938
939 /*
940 * At this point we know that as long as we hold os->os_lock, the dnode
941 * cannot be freed and fields within the dnode can be safely accessed.
942 * The objset listing this dnode cannot go away as long as this dnode is
943 * on its list.
944 */
945 rw_exit(&os_lock);
946 if (DMU_OBJECT_IS_SPECIAL(odn->dn_object)) {
947 mutex_exit(&os->os_lock);
948 DNODE_STAT_BUMP(dnode_move_special);
949 return (KMEM_CBRC_NO);
950 }
951 ASSERT(odn->dn_dbuf != NULL); /* only "special" dnodes have no parent */
952
953 /*
954 * Lock the dnode handle to prevent the dnode from obtaining any new
955 * holds. This also prevents the descendant dbufs and the bonus dbuf
956 * from accessing the dnode, so that we can discount their holds. The
957 * handle is safe to access because we know that while the dnode cannot
958 * go away, neither can its handle. Once we hold dnh_zrlock, we can
959 * safely move any dnode referenced only by dbufs.
960 */
961 if (!zrl_tryenter(&odn->dn_handle->dnh_zrlock)) {
962 mutex_exit(&os->os_lock);
963 DNODE_STAT_BUMP(dnode_move_handle);
964 return (KMEM_CBRC_LATER);
965 }
966
967 /*
968 * Ensure a consistent view of the dnode's holds and the dnode's dbufs.
969 * We need to guarantee that there is a hold for every dbuf in order to
970 * determine whether the dnode is actively referenced. Falsely matching
971 * a dbuf to an active hold would lead to an unsafe move. It's possible
972 * that a thread already having an active dnode hold is about to add a
973 * dbuf, and we can't compare hold and dbuf counts while the add is in
974 * progress.
975 */
976 if (!rw_tryenter(&odn->dn_struct_rwlock, RW_WRITER)) {
977 zrl_exit(&odn->dn_handle->dnh_zrlock);
978 mutex_exit(&os->os_lock);
979 DNODE_STAT_BUMP(dnode_move_rwlock);
980 return (KMEM_CBRC_LATER);
981 }
982
983 /*
984 * A dbuf may be removed (evicted) without an active dnode hold. In that
985 * case, the dbuf count is decremented under the handle lock before the
986 * dbuf's hold is released. This order ensures that if we count the hold
987 * after the dbuf is removed but before its hold is released, we will
988 * treat the unmatched hold as active and exit safely. If we count the
989 * hold before the dbuf is removed, the hold is discounted, and the
990 * removal is blocked until the move completes.
991 */
992 refcount = zfs_refcount_count(&odn->dn_holds);
993 ASSERT(refcount >= 0);
994 dbufs = DN_DBUFS_COUNT(odn);
995
996 /* We can't have more dbufs than dnode holds. */
997 ASSERT3U(dbufs, <=, refcount);
998 DTRACE_PROBE3(dnode__move, dnode_t *, odn, int64_t, refcount,
999 uint32_t, dbufs);
1000
1001 if (refcount > dbufs) {
1002 rw_exit(&odn->dn_struct_rwlock);
1003 zrl_exit(&odn->dn_handle->dnh_zrlock);
1004 mutex_exit(&os->os_lock);
1005 DNODE_STAT_BUMP(dnode_move_active);
1006 return (KMEM_CBRC_LATER);
1007 }
1008
1009 rw_exit(&odn->dn_struct_rwlock);
1010
1011 /*
1012 * At this point we know that anyone with a hold on the dnode is not
1013 * actively referencing it. The dnode is known and in a valid state to
1014 * move. We're holding the locks needed to execute the critical section.
1015 */
1016 dnode_move_impl(odn, ndn);
1017
1018 list_link_replace(&odn->dn_link, &ndn->dn_link);
1019 /* If the dnode was safe to move, the refcount cannot have changed. */
1020 ASSERT(refcount == zfs_refcount_count(&ndn->dn_holds));
1021 ASSERT(dbufs == DN_DBUFS_COUNT(ndn));
1022 zrl_exit(&ndn->dn_handle->dnh_zrlock); /* handle has moved */
1023 mutex_exit(&os->os_lock);
1024
1025 return (KMEM_CBRC_YES);
1026 }
1027 #endif /* _KERNEL */
1028
1029 static void
1030 dnode_slots_hold(dnode_children_t *children, int idx, int slots)
1031 {
1032 ASSERT3S(idx + slots, <=, DNODES_PER_BLOCK);
1033
1034 for (int i = idx; i < idx + slots; i++) {
1035 dnode_handle_t *dnh = &children->dnc_children[i];
1036 zrl_add(&dnh->dnh_zrlock);
1037 }
1038 }
1039
1040 static void
1041 dnode_slots_rele(dnode_children_t *children, int idx, int slots)
1042 {
1043 ASSERT3S(idx + slots, <=, DNODES_PER_BLOCK);
1044
1045 for (int i = idx; i < idx + slots; i++) {
1046 dnode_handle_t *dnh = &children->dnc_children[i];
1047
1048 if (zrl_is_locked(&dnh->dnh_zrlock))
1049 zrl_exit(&dnh->dnh_zrlock);
1050 else
1051 zrl_remove(&dnh->dnh_zrlock);
1052 }
1053 }
1054
1055 static int
1056 dnode_slots_tryenter(dnode_children_t *children, int idx, int slots)
1057 {
1058 ASSERT3S(idx + slots, <=, DNODES_PER_BLOCK);
1059
1060 for (int i = idx; i < idx + slots; i++) {
1061 dnode_handle_t *dnh = &children->dnc_children[i];
1062
1063 if (!zrl_tryenter(&dnh->dnh_zrlock)) {
1064 for (int j = idx; j < i; j++) {
1065 dnh = &children->dnc_children[j];
1066 zrl_exit(&dnh->dnh_zrlock);
1067 }
1068
1069 return (0);
1070 }
1071 }
1072
1073 return (1);
1074 }
1075
1076 static void
1077 dnode_set_slots(dnode_children_t *children, int idx, int slots, void *ptr)
1078 {
1079 ASSERT3S(idx + slots, <=, DNODES_PER_BLOCK);
1080
1081 for (int i = idx; i < idx + slots; i++) {
1082 dnode_handle_t *dnh = &children->dnc_children[i];
1083 dnh->dnh_dnode = ptr;
1084 }
1085 }
1086
1087 static boolean_t
1088 dnode_check_slots_free(dnode_children_t *children, int idx, int slots)
1089 {
1090 ASSERT3S(idx + slots, <=, DNODES_PER_BLOCK);
1091
1092 /*
1093 * If all dnode slots are either already free or
1094 * evictable return B_TRUE.
1095 */
1096 for (int i = idx; i < idx + slots; i++) {
1097 dnode_handle_t *dnh = &children->dnc_children[i];
1098 dnode_t *dn = dnh->dnh_dnode;
1099
1100 if (dn == DN_SLOT_FREE) {
1101 continue;
1102 } else if (DN_SLOT_IS_PTR(dn)) {
1103 mutex_enter(&dn->dn_mtx);
1104 boolean_t can_free = (dn->dn_type == DMU_OT_NONE &&
1105 zfs_refcount_is_zero(&dn->dn_holds) &&
1106 !DNODE_IS_DIRTY(dn));
1107 mutex_exit(&dn->dn_mtx);
1108
1109 if (!can_free)
1110 return (B_FALSE);
1111 else
1112 continue;
1113 } else {
1114 return (B_FALSE);
1115 }
1116 }
1117
1118 return (B_TRUE);
1119 }
1120
1121 static void
1122 dnode_reclaim_slots(dnode_children_t *children, int idx, int slots)
1123 {
1124 ASSERT3S(idx + slots, <=, DNODES_PER_BLOCK);
1125
1126 for (int i = idx; i < idx + slots; i++) {
1127 dnode_handle_t *dnh = &children->dnc_children[i];
1128
1129 ASSERT(zrl_is_locked(&dnh->dnh_zrlock));
1130
1131 if (DN_SLOT_IS_PTR(dnh->dnh_dnode)) {
1132 ASSERT3S(dnh->dnh_dnode->dn_type, ==, DMU_OT_NONE);
1133 dnode_destroy(dnh->dnh_dnode);
1134 dnh->dnh_dnode = DN_SLOT_FREE;
1135 }
1136 }
1137 }
1138
1139 void
1140 dnode_free_interior_slots(dnode_t *dn)
1141 {
1142 dnode_children_t *children = dmu_buf_get_user(&dn->dn_dbuf->db);
1143 int epb = dn->dn_dbuf->db.db_size >> DNODE_SHIFT;
1144 int idx = (dn->dn_object & (epb - 1)) + 1;
1145 int slots = dn->dn_num_slots - 1;
1146
1147 if (slots == 0)
1148 return;
1149
1150 ASSERT3S(idx + slots, <=, DNODES_PER_BLOCK);
1151
1152 while (!dnode_slots_tryenter(children, idx, slots)) {
1153 DNODE_STAT_BUMP(dnode_free_interior_lock_retry);
1154 cond_resched();
1155 }
1156
1157 dnode_set_slots(children, idx, slots, DN_SLOT_FREE);
1158 dnode_slots_rele(children, idx, slots);
1159 }
1160
1161 void
1162 dnode_special_close(dnode_handle_t *dnh)
1163 {
1164 dnode_t *dn = dnh->dnh_dnode;
1165
1166 /*
1167 * Ensure dnode_rele_and_unlock() has released dn_mtx, after final
1168 * zfs_refcount_remove()
1169 */
1170 mutex_enter(&dn->dn_mtx);
1171 if (zfs_refcount_count(&dn->dn_holds) > 0)
1172 cv_wait(&dn->dn_nodnholds, &dn->dn_mtx);
1173 mutex_exit(&dn->dn_mtx);
1174 ASSERT3U(zfs_refcount_count(&dn->dn_holds), ==, 0);
1175
1176 ASSERT(dn->dn_dbuf == NULL ||
1177 dmu_buf_get_user(&dn->dn_dbuf->db) == NULL);
1178 zrl_add(&dnh->dnh_zrlock);
1179 dnode_destroy(dn); /* implicit zrl_remove() */
1180 zrl_destroy(&dnh->dnh_zrlock);
1181 dnh->dnh_dnode = NULL;
1182 }
1183
1184 void
1185 dnode_special_open(objset_t *os, dnode_phys_t *dnp, uint64_t object,
1186 dnode_handle_t *dnh)
1187 {
1188 dnode_t *dn;
1189
1190 zrl_init(&dnh->dnh_zrlock);
1191 VERIFY3U(1, ==, zrl_tryenter(&dnh->dnh_zrlock));
1192
1193 dn = dnode_create(os, dnp, NULL, object, dnh);
1194 DNODE_VERIFY(dn);
1195
1196 zrl_exit(&dnh->dnh_zrlock);
1197 }
1198
1199 static void
1200 dnode_buf_evict_async(void *dbu)
1201 {
1202 dnode_children_t *dnc = dbu;
1203
1204 DNODE_STAT_BUMP(dnode_buf_evict);
1205
1206 for (int i = 0; i < dnc->dnc_count; i++) {
1207 dnode_handle_t *dnh = &dnc->dnc_children[i];
1208 dnode_t *dn;
1209
1210 /*
1211 * The dnode handle lock guards against the dnode moving to
1212 * another valid address, so there is no need here to guard
1213 * against changes to or from NULL.
1214 */
1215 if (!DN_SLOT_IS_PTR(dnh->dnh_dnode)) {
1216 zrl_destroy(&dnh->dnh_zrlock);
1217 dnh->dnh_dnode = DN_SLOT_UNINIT;
1218 continue;
1219 }
1220
1221 zrl_add(&dnh->dnh_zrlock);
1222 dn = dnh->dnh_dnode;
1223 /*
1224 * If there are holds on this dnode, then there should
1225 * be holds on the dnode's containing dbuf as well; thus
1226 * it wouldn't be eligible for eviction and this function
1227 * would not have been called.
1228 */
1229 ASSERT(zfs_refcount_is_zero(&dn->dn_holds));
1230 ASSERT(zfs_refcount_is_zero(&dn->dn_tx_holds));
1231
1232 dnode_destroy(dn); /* implicit zrl_remove() for first slot */
1233 zrl_destroy(&dnh->dnh_zrlock);
1234 dnh->dnh_dnode = DN_SLOT_UNINIT;
1235 }
1236 kmem_free(dnc, sizeof (dnode_children_t) +
1237 dnc->dnc_count * sizeof (dnode_handle_t));
1238 }
1239
1240 /*
1241 * When the DNODE_MUST_BE_FREE flag is set, the "slots" parameter is used
1242 * to ensure the hole at the specified object offset is large enough to
1243 * hold the dnode being created. The slots parameter is also used to ensure
1244 * a dnode does not span multiple dnode blocks. In both of these cases, if
1245 * a failure occurs, ENOSPC is returned. Keep in mind, these failure cases
1246 * are only possible when using DNODE_MUST_BE_FREE.
1247 *
1248 * If the DNODE_MUST_BE_ALLOCATED flag is set, "slots" must be 0.
1249 * dnode_hold_impl() will check if the requested dnode is already consumed
1250 * as an extra dnode slot by an large dnode, in which case it returns
1251 * ENOENT.
1252 *
1253 * If the DNODE_DRY_RUN flag is set, we don't actually hold the dnode, just
1254 * return whether the hold would succeed or not. tag and dnp should set to
1255 * NULL in this case.
1256 *
1257 * errors:
1258 * EINVAL - Invalid object number or flags.
1259 * ENOSPC - Hole too small to fulfill "slots" request (DNODE_MUST_BE_FREE)
1260 * EEXIST - Refers to an allocated dnode (DNODE_MUST_BE_FREE)
1261 * - Refers to a freeing dnode (DNODE_MUST_BE_FREE)
1262 * - Refers to an interior dnode slot (DNODE_MUST_BE_ALLOCATED)
1263 * ENOENT - The requested dnode is not allocated (DNODE_MUST_BE_ALLOCATED)
1264 * - The requested dnode is being freed (DNODE_MUST_BE_ALLOCATED)
1265 * EIO - I/O error when reading the meta dnode dbuf.
1266 *
1267 * succeeds even for free dnodes.
1268 */
1269 int
1270 dnode_hold_impl(objset_t *os, uint64_t object, int flag, int slots,
1271 void *tag, dnode_t **dnp)
1272 {
1273 int epb, idx, err;
1274 int drop_struct_lock = FALSE;
1275 int type;
1276 uint64_t blk;
1277 dnode_t *mdn, *dn;
1278 dmu_buf_impl_t *db;
1279 dnode_children_t *dnc;
1280 dnode_phys_t *dn_block;
1281 dnode_handle_t *dnh;
1282
1283 ASSERT(!(flag & DNODE_MUST_BE_ALLOCATED) || (slots == 0));
1284 ASSERT(!(flag & DNODE_MUST_BE_FREE) || (slots > 0));
1285 IMPLY(flag & DNODE_DRY_RUN, (tag == NULL) && (dnp == NULL));
1286
1287 /*
1288 * If you are holding the spa config lock as writer, you shouldn't
1289 * be asking the DMU to do *anything* unless it's the root pool
1290 * which may require us to read from the root filesystem while
1291 * holding some (not all) of the locks as writer.
1292 */
1293 ASSERT(spa_config_held(os->os_spa, SCL_ALL, RW_WRITER) == 0 ||
1294 (spa_is_root(os->os_spa) &&
1295 spa_config_held(os->os_spa, SCL_STATE, RW_WRITER)));
1296
1297 ASSERT((flag & DNODE_MUST_BE_ALLOCATED) || (flag & DNODE_MUST_BE_FREE));
1298
1299 if (object == DMU_USERUSED_OBJECT || object == DMU_GROUPUSED_OBJECT ||
1300 object == DMU_PROJECTUSED_OBJECT) {
1301 if (object == DMU_USERUSED_OBJECT)
1302 dn = DMU_USERUSED_DNODE(os);
1303 else if (object == DMU_GROUPUSED_OBJECT)
1304 dn = DMU_GROUPUSED_DNODE(os);
1305 else
1306 dn = DMU_PROJECTUSED_DNODE(os);
1307 if (dn == NULL)
1308 return (SET_ERROR(ENOENT));
1309 type = dn->dn_type;
1310 if ((flag & DNODE_MUST_BE_ALLOCATED) && type == DMU_OT_NONE)
1311 return (SET_ERROR(ENOENT));
1312 if ((flag & DNODE_MUST_BE_FREE) && type != DMU_OT_NONE)
1313 return (SET_ERROR(EEXIST));
1314 DNODE_VERIFY(dn);
1315 /* Don't actually hold if dry run, just return 0 */
1316 if (!(flag & DNODE_DRY_RUN)) {
1317 (void) zfs_refcount_add(&dn->dn_holds, tag);
1318 *dnp = dn;
1319 }
1320 return (0);
1321 }
1322
1323 if (object == 0 || object >= DN_MAX_OBJECT)
1324 return (SET_ERROR(EINVAL));
1325
1326 mdn = DMU_META_DNODE(os);
1327 ASSERT(mdn->dn_object == DMU_META_DNODE_OBJECT);
1328
1329 DNODE_VERIFY(mdn);
1330
1331 if (!RW_WRITE_HELD(&mdn->dn_struct_rwlock)) {
1332 rw_enter(&mdn->dn_struct_rwlock, RW_READER);
1333 drop_struct_lock = TRUE;
1334 }
1335
1336 blk = dbuf_whichblock(mdn, 0, object * sizeof (dnode_phys_t));
1337 db = dbuf_hold(mdn, blk, FTAG);
1338 if (drop_struct_lock)
1339 rw_exit(&mdn->dn_struct_rwlock);
1340 if (db == NULL) {
1341 DNODE_STAT_BUMP(dnode_hold_dbuf_hold);
1342 return (SET_ERROR(EIO));
1343 }
1344
1345 /*
1346 * We do not need to decrypt to read the dnode so it doesn't matter
1347 * if we get the encrypted or decrypted version.
1348 */
1349 err = dbuf_read(db, NULL, DB_RF_CANFAIL |
1350 DB_RF_NO_DECRYPT | DB_RF_NOPREFETCH);
1351 if (err) {
1352 DNODE_STAT_BUMP(dnode_hold_dbuf_read);
1353 dbuf_rele(db, FTAG);
1354 return (err);
1355 }
1356
1357 ASSERT3U(db->db.db_size, >=, 1<<DNODE_SHIFT);
1358 epb = db->db.db_size >> DNODE_SHIFT;
1359
1360 idx = object & (epb - 1);
1361 dn_block = (dnode_phys_t *)db->db.db_data;
1362
1363 ASSERT(DB_DNODE(db)->dn_type == DMU_OT_DNODE);
1364 dnc = dmu_buf_get_user(&db->db);
1365 dnh = NULL;
1366 if (dnc == NULL) {
1367 dnode_children_t *winner;
1368 int skip = 0;
1369
1370 dnc = kmem_zalloc(sizeof (dnode_children_t) +
1371 epb * sizeof (dnode_handle_t), KM_SLEEP);
1372 dnc->dnc_count = epb;
1373 dnh = &dnc->dnc_children[0];
1374
1375 /* Initialize dnode slot status from dnode_phys_t */
1376 for (int i = 0; i < epb; i++) {
1377 zrl_init(&dnh[i].dnh_zrlock);
1378
1379 if (skip) {
1380 skip--;
1381 continue;
1382 }
1383
1384 if (dn_block[i].dn_type != DMU_OT_NONE) {
1385 int interior = dn_block[i].dn_extra_slots;
1386
1387 dnode_set_slots(dnc, i, 1, DN_SLOT_ALLOCATED);
1388 dnode_set_slots(dnc, i + 1, interior,
1389 DN_SLOT_INTERIOR);
1390 skip = interior;
1391 } else {
1392 dnh[i].dnh_dnode = DN_SLOT_FREE;
1393 skip = 0;
1394 }
1395 }
1396
1397 dmu_buf_init_user(&dnc->dnc_dbu, NULL,
1398 dnode_buf_evict_async, NULL);
1399 winner = dmu_buf_set_user(&db->db, &dnc->dnc_dbu);
1400 if (winner != NULL) {
1401
1402 for (int i = 0; i < epb; i++)
1403 zrl_destroy(&dnh[i].dnh_zrlock);
1404
1405 kmem_free(dnc, sizeof (dnode_children_t) +
1406 epb * sizeof (dnode_handle_t));
1407 dnc = winner;
1408 }
1409 }
1410
1411 ASSERT(dnc->dnc_count == epb);
1412
1413 if (flag & DNODE_MUST_BE_ALLOCATED) {
1414 slots = 1;
1415
1416 dnode_slots_hold(dnc, idx, slots);
1417 dnh = &dnc->dnc_children[idx];
1418
1419 if (DN_SLOT_IS_PTR(dnh->dnh_dnode)) {
1420 dn = dnh->dnh_dnode;
1421 } else if (dnh->dnh_dnode == DN_SLOT_INTERIOR) {
1422 DNODE_STAT_BUMP(dnode_hold_alloc_interior);
1423 dnode_slots_rele(dnc, idx, slots);
1424 dbuf_rele(db, FTAG);
1425 return (SET_ERROR(EEXIST));
1426 } else if (dnh->dnh_dnode != DN_SLOT_ALLOCATED) {
1427 DNODE_STAT_BUMP(dnode_hold_alloc_misses);
1428 dnode_slots_rele(dnc, idx, slots);
1429 dbuf_rele(db, FTAG);
1430 return (SET_ERROR(ENOENT));
1431 } else {
1432 dnode_slots_rele(dnc, idx, slots);
1433 while (!dnode_slots_tryenter(dnc, idx, slots)) {
1434 DNODE_STAT_BUMP(dnode_hold_alloc_lock_retry);
1435 cond_resched();
1436 }
1437
1438 /*
1439 * Someone else won the race and called dnode_create()
1440 * after we checked DN_SLOT_IS_PTR() above but before
1441 * we acquired the lock.
1442 */
1443 if (DN_SLOT_IS_PTR(dnh->dnh_dnode)) {
1444 DNODE_STAT_BUMP(dnode_hold_alloc_lock_misses);
1445 dn = dnh->dnh_dnode;
1446 } else {
1447 dn = dnode_create(os, dn_block + idx, db,
1448 object, dnh);
1449 }
1450 }
1451
1452 mutex_enter(&dn->dn_mtx);
1453 if (dn->dn_type == DMU_OT_NONE || dn->dn_free_txg != 0) {
1454 DNODE_STAT_BUMP(dnode_hold_alloc_type_none);
1455 mutex_exit(&dn->dn_mtx);
1456 dnode_slots_rele(dnc, idx, slots);
1457 dbuf_rele(db, FTAG);
1458 return (SET_ERROR(ENOENT));
1459 }
1460
1461 /* Don't actually hold if dry run, just return 0 */
1462 if (flag & DNODE_DRY_RUN) {
1463 mutex_exit(&dn->dn_mtx);
1464 dnode_slots_rele(dnc, idx, slots);
1465 dbuf_rele(db, FTAG);
1466 return (0);
1467 }
1468
1469 DNODE_STAT_BUMP(dnode_hold_alloc_hits);
1470 } else if (flag & DNODE_MUST_BE_FREE) {
1471
1472 if (idx + slots - 1 >= DNODES_PER_BLOCK) {
1473 DNODE_STAT_BUMP(dnode_hold_free_overflow);
1474 dbuf_rele(db, FTAG);
1475 return (SET_ERROR(ENOSPC));
1476 }
1477
1478 dnode_slots_hold(dnc, idx, slots);
1479
1480 if (!dnode_check_slots_free(dnc, idx, slots)) {
1481 DNODE_STAT_BUMP(dnode_hold_free_misses);
1482 dnode_slots_rele(dnc, idx, slots);
1483 dbuf_rele(db, FTAG);
1484 return (SET_ERROR(ENOSPC));
1485 }
1486
1487 dnode_slots_rele(dnc, idx, slots);
1488 while (!dnode_slots_tryenter(dnc, idx, slots)) {
1489 DNODE_STAT_BUMP(dnode_hold_free_lock_retry);
1490 cond_resched();
1491 }
1492
1493 if (!dnode_check_slots_free(dnc, idx, slots)) {
1494 DNODE_STAT_BUMP(dnode_hold_free_lock_misses);
1495 dnode_slots_rele(dnc, idx, slots);
1496 dbuf_rele(db, FTAG);
1497 return (SET_ERROR(ENOSPC));
1498 }
1499
1500 /*
1501 * Allocated but otherwise free dnodes which would
1502 * be in the interior of a multi-slot dnodes need
1503 * to be freed. Single slot dnodes can be safely
1504 * re-purposed as a performance optimization.
1505 */
1506 if (slots > 1)
1507 dnode_reclaim_slots(dnc, idx + 1, slots - 1);
1508
1509 dnh = &dnc->dnc_children[idx];
1510 if (DN_SLOT_IS_PTR(dnh->dnh_dnode)) {
1511 dn = dnh->dnh_dnode;
1512 } else {
1513 dn = dnode_create(os, dn_block + idx, db,
1514 object, dnh);
1515 }
1516
1517 mutex_enter(&dn->dn_mtx);
1518 if (!zfs_refcount_is_zero(&dn->dn_holds) || dn->dn_free_txg) {
1519 DNODE_STAT_BUMP(dnode_hold_free_refcount);
1520 mutex_exit(&dn->dn_mtx);
1521 dnode_slots_rele(dnc, idx, slots);
1522 dbuf_rele(db, FTAG);
1523 return (SET_ERROR(EEXIST));
1524 }
1525
1526 /* Don't actually hold if dry run, just return 0 */
1527 if (flag & DNODE_DRY_RUN) {
1528 mutex_exit(&dn->dn_mtx);
1529 dnode_slots_rele(dnc, idx, slots);
1530 dbuf_rele(db, FTAG);
1531 return (0);
1532 }
1533
1534 dnode_set_slots(dnc, idx + 1, slots - 1, DN_SLOT_INTERIOR);
1535 DNODE_STAT_BUMP(dnode_hold_free_hits);
1536 } else {
1537 dbuf_rele(db, FTAG);
1538 return (SET_ERROR(EINVAL));
1539 }
1540
1541 ASSERT0(dn->dn_free_txg);
1542
1543 if (zfs_refcount_add(&dn->dn_holds, tag) == 1)
1544 dbuf_add_ref(db, dnh);
1545
1546 mutex_exit(&dn->dn_mtx);
1547
1548 /* Now we can rely on the hold to prevent the dnode from moving. */
1549 dnode_slots_rele(dnc, idx, slots);
1550
1551 DNODE_VERIFY(dn);
1552 ASSERT3P(dnp, !=, NULL);
1553 ASSERT3P(dn->dn_dbuf, ==, db);
1554 ASSERT3U(dn->dn_object, ==, object);
1555 dbuf_rele(db, FTAG);
1556
1557 *dnp = dn;
1558 return (0);
1559 }
1560
1561 /*
1562 * Return held dnode if the object is allocated, NULL if not.
1563 */
1564 int
1565 dnode_hold(objset_t *os, uint64_t object, void *tag, dnode_t **dnp)
1566 {
1567 return (dnode_hold_impl(os, object, DNODE_MUST_BE_ALLOCATED, 0, tag,
1568 dnp));
1569 }
1570
1571 /*
1572 * Can only add a reference if there is already at least one
1573 * reference on the dnode. Returns FALSE if unable to add a
1574 * new reference.
1575 */
1576 boolean_t
1577 dnode_add_ref(dnode_t *dn, void *tag)
1578 {
1579 mutex_enter(&dn->dn_mtx);
1580 if (zfs_refcount_is_zero(&dn->dn_holds)) {
1581 mutex_exit(&dn->dn_mtx);
1582 return (FALSE);
1583 }
1584 VERIFY(1 < zfs_refcount_add(&dn->dn_holds, tag));
1585 mutex_exit(&dn->dn_mtx);
1586 return (TRUE);
1587 }
1588
1589 void
1590 dnode_rele(dnode_t *dn, void *tag)
1591 {
1592 mutex_enter(&dn->dn_mtx);
1593 dnode_rele_and_unlock(dn, tag, B_FALSE);
1594 }
1595
1596 void
1597 dnode_rele_and_unlock(dnode_t *dn, void *tag, boolean_t evicting)
1598 {
1599 uint64_t refs;
1600 /* Get while the hold prevents the dnode from moving. */
1601 dmu_buf_impl_t *db = dn->dn_dbuf;
1602 dnode_handle_t *dnh = dn->dn_handle;
1603
1604 refs = zfs_refcount_remove(&dn->dn_holds, tag);
1605 if (refs == 0)
1606 cv_broadcast(&dn->dn_nodnholds);
1607 mutex_exit(&dn->dn_mtx);
1608 /* dnode could get destroyed at this point, so don't use it anymore */
1609
1610 /*
1611 * It's unsafe to release the last hold on a dnode by dnode_rele() or
1612 * indirectly by dbuf_rele() while relying on the dnode handle to
1613 * prevent the dnode from moving, since releasing the last hold could
1614 * result in the dnode's parent dbuf evicting its dnode handles. For
1615 * that reason anyone calling dnode_rele() or dbuf_rele() without some
1616 * other direct or indirect hold on the dnode must first drop the dnode
1617 * handle.
1618 */
1619 #ifdef ZFS_DEBUG
1620 ASSERT(refs > 0 || dnh->dnh_zrlock.zr_owner != curthread);
1621 #endif
1622
1623 /* NOTE: the DNODE_DNODE does not have a dn_dbuf */
1624 if (refs == 0 && db != NULL) {
1625 /*
1626 * Another thread could add a hold to the dnode handle in
1627 * dnode_hold_impl() while holding the parent dbuf. Since the
1628 * hold on the parent dbuf prevents the handle from being
1629 * destroyed, the hold on the handle is OK. We can't yet assert
1630 * that the handle has zero references, but that will be
1631 * asserted anyway when the handle gets destroyed.
1632 */
1633 mutex_enter(&db->db_mtx);
1634 dbuf_rele_and_unlock(db, dnh, evicting);
1635 }
1636 }
1637
1638 /*
1639 * Test whether we can create a dnode at the specified location.
1640 */
1641 int
1642 dnode_try_claim(objset_t *os, uint64_t object, int slots)
1643 {
1644 return (dnode_hold_impl(os, object, DNODE_MUST_BE_FREE | DNODE_DRY_RUN,
1645 slots, NULL, NULL));
1646 }
1647
1648 /*
1649 * Checks if the dnode contains any uncommitted dirty records.
1650 */
1651 boolean_t
1652 dnode_is_dirty(dnode_t *dn)
1653 {
1654 mutex_enter(&dn->dn_mtx);
1655
1656 for (int i = 0; i < TXG_SIZE; i++) {
1657 if (multilist_link_active(&dn->dn_dirty_link[i])) {
1658 mutex_exit(&dn->dn_mtx);
1659 return (B_TRUE);
1660 }
1661 }
1662
1663 mutex_exit(&dn->dn_mtx);
1664
1665 return (B_FALSE);
1666 }
1667
1668 void
1669 dnode_setdirty(dnode_t *dn, dmu_tx_t *tx)
1670 {
1671 objset_t *os = dn->dn_objset;
1672 uint64_t txg = tx->tx_txg;
1673
1674 if (DMU_OBJECT_IS_SPECIAL(dn->dn_object)) {
1675 dsl_dataset_dirty(os->os_dsl_dataset, tx);
1676 return;
1677 }
1678
1679 DNODE_VERIFY(dn);
1680
1681 #ifdef ZFS_DEBUG
1682 mutex_enter(&dn->dn_mtx);
1683 ASSERT(dn->dn_phys->dn_type || dn->dn_allocated_txg);
1684 ASSERT(dn->dn_free_txg == 0 || dn->dn_free_txg >= txg);
1685 mutex_exit(&dn->dn_mtx);
1686 #endif
1687
1688 /*
1689 * Determine old uid/gid when necessary
1690 */
1691 dmu_objset_userquota_get_ids(dn, B_TRUE, tx);
1692
1693 multilist_t *dirtylist = &os->os_dirty_dnodes[txg & TXG_MASK];
1694 multilist_sublist_t *mls = multilist_sublist_lock_obj(dirtylist, dn);
1695
1696 /*
1697 * If we are already marked dirty, we're done.
1698 */
1699 if (multilist_link_active(&dn->dn_dirty_link[txg & TXG_MASK])) {
1700 multilist_sublist_unlock(mls);
1701 return;
1702 }
1703
1704 ASSERT(!zfs_refcount_is_zero(&dn->dn_holds) ||
1705 !avl_is_empty(&dn->dn_dbufs));
1706 ASSERT(dn->dn_datablksz != 0);
1707 ASSERT0(dn->dn_next_bonuslen[txg & TXG_MASK]);
1708 ASSERT0(dn->dn_next_blksz[txg & TXG_MASK]);
1709 ASSERT0(dn->dn_next_bonustype[txg & TXG_MASK]);
1710
1711 dprintf_ds(os->os_dsl_dataset, "obj=%llu txg=%llu\n",
1712 (u_longlong_t)dn->dn_object, (u_longlong_t)txg);
1713
1714 multilist_sublist_insert_head(mls, dn);
1715
1716 multilist_sublist_unlock(mls);
1717
1718 /*
1719 * The dnode maintains a hold on its containing dbuf as
1720 * long as there are holds on it. Each instantiated child
1721 * dbuf maintains a hold on the dnode. When the last child
1722 * drops its hold, the dnode will drop its hold on the
1723 * containing dbuf. We add a "dirty hold" here so that the
1724 * dnode will hang around after we finish processing its
1725 * children.
1726 */
1727 VERIFY(dnode_add_ref(dn, (void *)(uintptr_t)tx->tx_txg));
1728
1729 (void) dbuf_dirty(dn->dn_dbuf, tx);
1730
1731 dsl_dataset_dirty(os->os_dsl_dataset, tx);
1732 }
1733
1734 void
1735 dnode_free(dnode_t *dn, dmu_tx_t *tx)
1736 {
1737 mutex_enter(&dn->dn_mtx);
1738 if (dn->dn_type == DMU_OT_NONE || dn->dn_free_txg) {
1739 mutex_exit(&dn->dn_mtx);
1740 return;
1741 }
1742 dn->dn_free_txg = tx->tx_txg;
1743 mutex_exit(&dn->dn_mtx);
1744
1745 dnode_setdirty(dn, tx);
1746 }
1747
1748 /*
1749 * Try to change the block size for the indicated dnode. This can only
1750 * succeed if there are no blocks allocated or dirty beyond first block
1751 */
1752 int
1753 dnode_set_blksz(dnode_t *dn, uint64_t size, int ibs, dmu_tx_t *tx)
1754 {
1755 dmu_buf_impl_t *db;
1756 int err;
1757
1758 ASSERT3U(size, <=, spa_maxblocksize(dmu_objset_spa(dn->dn_objset)));
1759 if (size == 0)
1760 size = SPA_MINBLOCKSIZE;
1761 else
1762 size = P2ROUNDUP(size, SPA_MINBLOCKSIZE);
1763
1764 if (ibs == dn->dn_indblkshift)
1765 ibs = 0;
1766
1767 if (size >> SPA_MINBLOCKSHIFT == dn->dn_datablkszsec && ibs == 0)
1768 return (0);
1769
1770 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
1771
1772 /* Check for any allocated blocks beyond the first */
1773 if (dn->dn_maxblkid != 0)
1774 goto fail;
1775
1776 mutex_enter(&dn->dn_dbufs_mtx);
1777 for (db = avl_first(&dn->dn_dbufs); db != NULL;
1778 db = AVL_NEXT(&dn->dn_dbufs, db)) {
1779 if (db->db_blkid != 0 && db->db_blkid != DMU_BONUS_BLKID &&
1780 db->db_blkid != DMU_SPILL_BLKID) {
1781 mutex_exit(&dn->dn_dbufs_mtx);
1782 goto fail;
1783 }
1784 }
1785 mutex_exit(&dn->dn_dbufs_mtx);
1786
1787 if (ibs && dn->dn_nlevels != 1)
1788 goto fail;
1789
1790 /* resize the old block */
1791 err = dbuf_hold_impl(dn, 0, 0, TRUE, FALSE, FTAG, &db);
1792 if (err == 0) {
1793 dbuf_new_size(db, size, tx);
1794 } else if (err != ENOENT) {
1795 goto fail;
1796 }
1797
1798 dnode_setdblksz(dn, size);
1799 dnode_setdirty(dn, tx);
1800 dn->dn_next_blksz[tx->tx_txg&TXG_MASK] = size;
1801 if (ibs) {
1802 dn->dn_indblkshift = ibs;
1803 dn->dn_next_indblkshift[tx->tx_txg&TXG_MASK] = ibs;
1804 }
1805 /* release after we have fixed the blocksize in the dnode */
1806 if (db)
1807 dbuf_rele(db, FTAG);
1808
1809 rw_exit(&dn->dn_struct_rwlock);
1810 return (0);
1811
1812 fail:
1813 rw_exit(&dn->dn_struct_rwlock);
1814 return (SET_ERROR(ENOTSUP));
1815 }
1816
1817 static void
1818 dnode_set_nlevels_impl(dnode_t *dn, int new_nlevels, dmu_tx_t *tx)
1819 {
1820 uint64_t txgoff = tx->tx_txg & TXG_MASK;
1821 int old_nlevels = dn->dn_nlevels;
1822 dmu_buf_impl_t *db;
1823 list_t *list;
1824 dbuf_dirty_record_t *new, *dr, *dr_next;
1825
1826 ASSERT(RW_WRITE_HELD(&dn->dn_struct_rwlock));
1827
1828 ASSERT3U(new_nlevels, >, dn->dn_nlevels);
1829 dn->dn_nlevels = new_nlevels;
1830
1831 ASSERT3U(new_nlevels, >, dn->dn_next_nlevels[txgoff]);
1832 dn->dn_next_nlevels[txgoff] = new_nlevels;
1833
1834 /* dirty the left indirects */
1835 db = dbuf_hold_level(dn, old_nlevels, 0, FTAG);
1836 ASSERT(db != NULL);
1837 new = dbuf_dirty(db, tx);
1838 dbuf_rele(db, FTAG);
1839
1840 /* transfer the dirty records to the new indirect */
1841 mutex_enter(&dn->dn_mtx);
1842 mutex_enter(&new->dt.di.dr_mtx);
1843 list = &dn->dn_dirty_records[txgoff];
1844 for (dr = list_head(list); dr; dr = dr_next) {
1845 dr_next = list_next(&dn->dn_dirty_records[txgoff], dr);
1846
1847 IMPLY(dr->dr_dbuf == NULL, old_nlevels == 1);
1848 if (dr->dr_dbuf == NULL ||
1849 (dr->dr_dbuf->db_level == old_nlevels - 1 &&
1850 dr->dr_dbuf->db_blkid != DMU_BONUS_BLKID &&
1851 dr->dr_dbuf->db_blkid != DMU_SPILL_BLKID)) {
1852 list_remove(&dn->dn_dirty_records[txgoff], dr);
1853 list_insert_tail(&new->dt.di.dr_children, dr);
1854 dr->dr_parent = new;
1855 }
1856 }
1857 mutex_exit(&new->dt.di.dr_mtx);
1858 mutex_exit(&dn->dn_mtx);
1859 }
1860
1861 int
1862 dnode_set_nlevels(dnode_t *dn, int nlevels, dmu_tx_t *tx)
1863 {
1864 int ret = 0;
1865
1866 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
1867
1868 if (dn->dn_nlevels == nlevels) {
1869 ret = 0;
1870 goto out;
1871 } else if (nlevels < dn->dn_nlevels) {
1872 ret = SET_ERROR(EINVAL);
1873 goto out;
1874 }
1875
1876 dnode_set_nlevels_impl(dn, nlevels, tx);
1877
1878 out:
1879 rw_exit(&dn->dn_struct_rwlock);
1880 return (ret);
1881 }
1882
1883 /* read-holding callers must not rely on the lock being continuously held */
1884 void
1885 dnode_new_blkid(dnode_t *dn, uint64_t blkid, dmu_tx_t *tx, boolean_t have_read,
1886 boolean_t force)
1887 {
1888 int epbs, new_nlevels;
1889 uint64_t sz;
1890
1891 ASSERT(blkid != DMU_BONUS_BLKID);
1892
1893 ASSERT(have_read ?
1894 RW_READ_HELD(&dn->dn_struct_rwlock) :
1895 RW_WRITE_HELD(&dn->dn_struct_rwlock));
1896
1897 /*
1898 * if we have a read-lock, check to see if we need to do any work
1899 * before upgrading to a write-lock.
1900 */
1901 if (have_read) {
1902 if (blkid <= dn->dn_maxblkid)
1903 return;
1904
1905 if (!rw_tryupgrade(&dn->dn_struct_rwlock)) {
1906 rw_exit(&dn->dn_struct_rwlock);
1907 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
1908 }
1909 }
1910
1911 /*
1912 * Raw sends (indicated by the force flag) require that we take the
1913 * given blkid even if the value is lower than the current value.
1914 */
1915 if (!force && blkid <= dn->dn_maxblkid)
1916 goto out;
1917
1918 /*
1919 * We use the (otherwise unused) top bit of dn_next_maxblkid[txgoff]
1920 * to indicate that this field is set. This allows us to set the
1921 * maxblkid to 0 on an existing object in dnode_sync().
1922 */
1923 dn->dn_maxblkid = blkid;
1924 dn->dn_next_maxblkid[tx->tx_txg & TXG_MASK] =
1925 blkid | DMU_NEXT_MAXBLKID_SET;
1926
1927 /*
1928 * Compute the number of levels necessary to support the new maxblkid.
1929 * Raw sends will ensure nlevels is set correctly for us.
1930 */
1931 new_nlevels = 1;
1932 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT;
1933 for (sz = dn->dn_nblkptr;
1934 sz <= blkid && sz >= dn->dn_nblkptr; sz <<= epbs)
1935 new_nlevels++;
1936
1937 ASSERT3U(new_nlevels, <=, DN_MAX_LEVELS);
1938
1939 if (!force) {
1940 if (new_nlevels > dn->dn_nlevels)
1941 dnode_set_nlevels_impl(dn, new_nlevels, tx);
1942 } else {
1943 ASSERT3U(dn->dn_nlevels, >=, new_nlevels);
1944 }
1945
1946 out:
1947 if (have_read)
1948 rw_downgrade(&dn->dn_struct_rwlock);
1949 }
1950
1951 static void
1952 dnode_dirty_l1(dnode_t *dn, uint64_t l1blkid, dmu_tx_t *tx)
1953 {
1954 dmu_buf_impl_t *db = dbuf_hold_level(dn, 1, l1blkid, FTAG);
1955 if (db != NULL) {
1956 dmu_buf_will_dirty(&db->db, tx);
1957 dbuf_rele(db, FTAG);
1958 }
1959 }
1960
1961 /*
1962 * Dirty all the in-core level-1 dbufs in the range specified by start_blkid
1963 * and end_blkid.
1964 */
1965 static void
1966 dnode_dirty_l1range(dnode_t *dn, uint64_t start_blkid, uint64_t end_blkid,
1967 dmu_tx_t *tx)
1968 {
1969 dmu_buf_impl_t *db_search;
1970 dmu_buf_impl_t *db;
1971 avl_index_t where;
1972
1973 db_search = kmem_zalloc(sizeof (dmu_buf_impl_t), KM_SLEEP);
1974
1975 mutex_enter(&dn->dn_dbufs_mtx);
1976
1977 db_search->db_level = 1;
1978 db_search->db_blkid = start_blkid + 1;
1979 db_search->db_state = DB_SEARCH;
1980 for (;;) {
1981
1982 db = avl_find(&dn->dn_dbufs, db_search, &where);
1983 if (db == NULL)
1984 db = avl_nearest(&dn->dn_dbufs, where, AVL_AFTER);
1985
1986 if (db == NULL || db->db_level != 1 ||
1987 db->db_blkid >= end_blkid) {
1988 break;
1989 }
1990
1991 /*
1992 * Setup the next blkid we want to search for.
1993 */
1994 db_search->db_blkid = db->db_blkid + 1;
1995 ASSERT3U(db->db_blkid, >=, start_blkid);
1996
1997 /*
1998 * If the dbuf transitions to DB_EVICTING while we're trying
1999 * to dirty it, then we will be unable to discover it in
2000 * the dbuf hash table. This will result in a call to
2001 * dbuf_create() which needs to acquire the dn_dbufs_mtx
2002 * lock. To avoid a deadlock, we drop the lock before
2003 * dirtying the level-1 dbuf.
2004 */
2005 mutex_exit(&dn->dn_dbufs_mtx);
2006 dnode_dirty_l1(dn, db->db_blkid, tx);
2007 mutex_enter(&dn->dn_dbufs_mtx);
2008 }
2009
2010 #ifdef ZFS_DEBUG
2011 /*
2012 * Walk all the in-core level-1 dbufs and verify they have been dirtied.
2013 */
2014 db_search->db_level = 1;
2015 db_search->db_blkid = start_blkid + 1;
2016 db_search->db_state = DB_SEARCH;
2017 db = avl_find(&dn->dn_dbufs, db_search, &where);
2018 if (db == NULL)
2019 db = avl_nearest(&dn->dn_dbufs, where, AVL_AFTER);
2020 for (; db != NULL; db = AVL_NEXT(&dn->dn_dbufs, db)) {
2021 if (db->db_level != 1 || db->db_blkid >= end_blkid)
2022 break;
2023 if (db->db_state != DB_EVICTING)
2024 ASSERT(db->db_dirtycnt > 0);
2025 }
2026 #endif
2027 kmem_free(db_search, sizeof (dmu_buf_impl_t));
2028 mutex_exit(&dn->dn_dbufs_mtx);
2029 }
2030
2031 void
2032 dnode_set_dirtyctx(dnode_t *dn, dmu_tx_t *tx, void *tag)
2033 {
2034 /*
2035 * Don't set dirtyctx to SYNC if we're just modifying this as we
2036 * initialize the objset.
2037 */
2038 if (dn->dn_dirtyctx == DN_UNDIRTIED) {
2039 dsl_dataset_t *ds = dn->dn_objset->os_dsl_dataset;
2040
2041 if (ds != NULL) {
2042 rrw_enter(&ds->ds_bp_rwlock, RW_READER, tag);
2043 }
2044 if (!BP_IS_HOLE(dn->dn_objset->os_rootbp)) {
2045 if (dmu_tx_is_syncing(tx))
2046 dn->dn_dirtyctx = DN_DIRTY_SYNC;
2047 else
2048 dn->dn_dirtyctx = DN_DIRTY_OPEN;
2049 dn->dn_dirtyctx_firstset = tag;
2050 }
2051 if (ds != NULL) {
2052 rrw_exit(&ds->ds_bp_rwlock, tag);
2053 }
2054 }
2055 }
2056
2057 static void
2058 dnode_partial_zero(dnode_t *dn, uint64_t off, uint64_t blkoff, uint64_t len,
2059 dmu_tx_t *tx)
2060 {
2061 dmu_buf_impl_t *db;
2062 int res;
2063
2064 rw_enter(&dn->dn_struct_rwlock, RW_READER);
2065 res = dbuf_hold_impl(dn, 0, dbuf_whichblock(dn, 0, off), TRUE, FALSE,
2066 FTAG, &db);
2067 rw_exit(&dn->dn_struct_rwlock);
2068 if (res == 0) {
2069 db_lock_type_t dblt;
2070 boolean_t dirty;
2071
2072 dblt = dmu_buf_lock_parent(db, RW_READER, FTAG);
2073 /* don't dirty if not on disk and not dirty */
2074 dirty = !list_is_empty(&db->db_dirty_records) ||
2075 (db->db_blkptr && !BP_IS_HOLE(db->db_blkptr));
2076 dmu_buf_unlock_parent(db, dblt, FTAG);
2077 if (dirty) {
2078 caddr_t data;
2079
2080 dmu_buf_will_dirty(&db->db, tx);
2081 data = db->db.db_data;
2082 memset(data + blkoff, 0, len);
2083 }
2084 dbuf_rele(db, FTAG);
2085 }
2086 }
2087
2088 void
2089 dnode_free_range(dnode_t *dn, uint64_t off, uint64_t len, dmu_tx_t *tx)
2090 {
2091 uint64_t blkoff, blkid, nblks;
2092 int blksz, blkshift, head, tail;
2093 int trunc = FALSE;
2094 int epbs;
2095
2096 blksz = dn->dn_datablksz;
2097 blkshift = dn->dn_datablkshift;
2098 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT;
2099
2100 if (len == DMU_OBJECT_END) {
2101 len = UINT64_MAX - off;
2102 trunc = TRUE;
2103 }
2104
2105 /*
2106 * First, block align the region to free:
2107 */
2108 if (ISP2(blksz)) {
2109 head = P2NPHASE(off, blksz);
2110 blkoff = P2PHASE(off, blksz);
2111 if ((off >> blkshift) > dn->dn_maxblkid)
2112 return;
2113 } else {
2114 ASSERT(dn->dn_maxblkid == 0);
2115 if (off == 0 && len >= blksz) {
2116 /*
2117 * Freeing the whole block; fast-track this request.
2118 */
2119 blkid = 0;
2120 nblks = 1;
2121 if (dn->dn_nlevels > 1) {
2122 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
2123 dnode_dirty_l1(dn, 0, tx);
2124 rw_exit(&dn->dn_struct_rwlock);
2125 }
2126 goto done;
2127 } else if (off >= blksz) {
2128 /* Freeing past end-of-data */
2129 return;
2130 } else {
2131 /* Freeing part of the block. */
2132 head = blksz - off;
2133 ASSERT3U(head, >, 0);
2134 }
2135 blkoff = off;
2136 }
2137 /* zero out any partial block data at the start of the range */
2138 if (head) {
2139 ASSERT3U(blkoff + head, ==, blksz);
2140 if (len < head)
2141 head = len;
2142 dnode_partial_zero(dn, off, blkoff, head, tx);
2143 off += head;
2144 len -= head;
2145 }
2146
2147 /* If the range was less than one block, we're done */
2148 if (len == 0)
2149 return;
2150
2151 /* If the remaining range is past end of file, we're done */
2152 if ((off >> blkshift) > dn->dn_maxblkid)
2153 return;
2154
2155 ASSERT(ISP2(blksz));
2156 if (trunc)
2157 tail = 0;
2158 else
2159 tail = P2PHASE(len, blksz);
2160
2161 ASSERT0(P2PHASE(off, blksz));
2162 /* zero out any partial block data at the end of the range */
2163 if (tail) {
2164 if (len < tail)
2165 tail = len;
2166 dnode_partial_zero(dn, off + len, 0, tail, tx);
2167 len -= tail;
2168 }
2169
2170 /* If the range did not include a full block, we are done */
2171 if (len == 0)
2172 return;
2173
2174 ASSERT(IS_P2ALIGNED(off, blksz));
2175 ASSERT(trunc || IS_P2ALIGNED(len, blksz));
2176 blkid = off >> blkshift;
2177 nblks = len >> blkshift;
2178 if (trunc)
2179 nblks += 1;
2180
2181 /*
2182 * Dirty all the indirect blocks in this range. Note that only
2183 * the first and last indirect blocks can actually be written
2184 * (if they were partially freed) -- they must be dirtied, even if
2185 * they do not exist on disk yet. The interior blocks will
2186 * be freed by free_children(), so they will not actually be written.
2187 * Even though these interior blocks will not be written, we
2188 * dirty them for two reasons:
2189 *
2190 * - It ensures that the indirect blocks remain in memory until
2191 * syncing context. (They have already been prefetched by
2192 * dmu_tx_hold_free(), so we don't have to worry about reading
2193 * them serially here.)
2194 *
2195 * - The dirty space accounting will put pressure on the txg sync
2196 * mechanism to begin syncing, and to delay transactions if there
2197 * is a large amount of freeing. Even though these indirect
2198 * blocks will not be written, we could need to write the same
2199 * amount of space if we copy the freed BPs into deadlists.
2200 */
2201 if (dn->dn_nlevels > 1) {
2202 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
2203 uint64_t first, last;
2204
2205 first = blkid >> epbs;
2206 dnode_dirty_l1(dn, first, tx);
2207 if (trunc)
2208 last = dn->dn_maxblkid >> epbs;
2209 else
2210 last = (blkid + nblks - 1) >> epbs;
2211 if (last != first)
2212 dnode_dirty_l1(dn, last, tx);
2213
2214 dnode_dirty_l1range(dn, first, last, tx);
2215
2216 int shift = dn->dn_datablkshift + dn->dn_indblkshift -
2217 SPA_BLKPTRSHIFT;
2218 for (uint64_t i = first + 1; i < last; i++) {
2219 /*
2220 * Set i to the blockid of the next non-hole
2221 * level-1 indirect block at or after i. Note
2222 * that dnode_next_offset() operates in terms of
2223 * level-0-equivalent bytes.
2224 */
2225 uint64_t ibyte = i << shift;
2226 int err = dnode_next_offset(dn, DNODE_FIND_HAVELOCK,
2227 &ibyte, 2, 1, 0);
2228 i = ibyte >> shift;
2229 if (i >= last)
2230 break;
2231
2232 /*
2233 * Normally we should not see an error, either
2234 * from dnode_next_offset() or dbuf_hold_level()
2235 * (except for ESRCH from dnode_next_offset).
2236 * If there is an i/o error, then when we read
2237 * this block in syncing context, it will use
2238 * ZIO_FLAG_MUSTSUCCEED, and thus hang/panic according
2239 * to the "failmode" property. dnode_next_offset()
2240 * doesn't have a flag to indicate MUSTSUCCEED.
2241 */
2242 if (err != 0)
2243 break;
2244
2245 dnode_dirty_l1(dn, i, tx);
2246 }
2247 rw_exit(&dn->dn_struct_rwlock);
2248 }
2249
2250 done:
2251 /*
2252 * Add this range to the dnode range list.
2253 * We will finish up this free operation in the syncing phase.
2254 */
2255 mutex_enter(&dn->dn_mtx);
2256 {
2257 int txgoff = tx->tx_txg & TXG_MASK;
2258 if (dn->dn_free_ranges[txgoff] == NULL) {
2259 dn->dn_free_ranges[txgoff] = range_tree_create(NULL,
2260 RANGE_SEG64, NULL, 0, 0);
2261 }
2262 range_tree_clear(dn->dn_free_ranges[txgoff], blkid, nblks);
2263 range_tree_add(dn->dn_free_ranges[txgoff], blkid, nblks);
2264 }
2265 dprintf_dnode(dn, "blkid=%llu nblks=%llu txg=%llu\n",
2266 (u_longlong_t)blkid, (u_longlong_t)nblks,
2267 (u_longlong_t)tx->tx_txg);
2268 mutex_exit(&dn->dn_mtx);
2269
2270 dbuf_free_range(dn, blkid, blkid + nblks - 1, tx);
2271 dnode_setdirty(dn, tx);
2272 }
2273
2274 static boolean_t
2275 dnode_spill_freed(dnode_t *dn)
2276 {
2277 int i;
2278
2279 mutex_enter(&dn->dn_mtx);
2280 for (i = 0; i < TXG_SIZE; i++) {
2281 if (dn->dn_rm_spillblk[i] == DN_KILL_SPILLBLK)
2282 break;
2283 }
2284 mutex_exit(&dn->dn_mtx);
2285 return (i < TXG_SIZE);
2286 }
2287
2288 /* return TRUE if this blkid was freed in a recent txg, or FALSE if it wasn't */
2289 uint64_t
2290 dnode_block_freed(dnode_t *dn, uint64_t blkid)
2291 {
2292 void *dp = spa_get_dsl(dn->dn_objset->os_spa);
2293 int i;
2294
2295 if (blkid == DMU_BONUS_BLKID)
2296 return (FALSE);
2297
2298 /*
2299 * If we're in the process of opening the pool, dp will not be
2300 * set yet, but there shouldn't be anything dirty.
2301 */
2302 if (dp == NULL)
2303 return (FALSE);
2304
2305 if (dn->dn_free_txg)
2306 return (TRUE);
2307
2308 if (blkid == DMU_SPILL_BLKID)
2309 return (dnode_spill_freed(dn));
2310
2311 mutex_enter(&dn->dn_mtx);
2312 for (i = 0; i < TXG_SIZE; i++) {
2313 if (dn->dn_free_ranges[i] != NULL &&
2314 range_tree_contains(dn->dn_free_ranges[i], blkid, 1))
2315 break;
2316 }
2317 mutex_exit(&dn->dn_mtx);
2318 return (i < TXG_SIZE);
2319 }
2320
2321 /* call from syncing context when we actually write/free space for this dnode */
2322 void
2323 dnode_diduse_space(dnode_t *dn, int64_t delta)
2324 {
2325 uint64_t space;
2326 dprintf_dnode(dn, "dn=%p dnp=%p used=%llu delta=%lld\n",
2327 dn, dn->dn_phys,
2328 (u_longlong_t)dn->dn_phys->dn_used,
2329 (longlong_t)delta);
2330
2331 mutex_enter(&dn->dn_mtx);
2332 space = DN_USED_BYTES(dn->dn_phys);
2333 if (delta > 0) {
2334 ASSERT3U(space + delta, >=, space); /* no overflow */
2335 } else {
2336 ASSERT3U(space, >=, -delta); /* no underflow */
2337 }
2338 space += delta;
2339 if (spa_version(dn->dn_objset->os_spa) < SPA_VERSION_DNODE_BYTES) {
2340 ASSERT((dn->dn_phys->dn_flags & DNODE_FLAG_USED_BYTES) == 0);
2341 ASSERT0(P2PHASE(space, 1<<DEV_BSHIFT));
2342 dn->dn_phys->dn_used = space >> DEV_BSHIFT;
2343 } else {
2344 dn->dn_phys->dn_used = space;
2345 dn->dn_phys->dn_flags |= DNODE_FLAG_USED_BYTES;
2346 }
2347 mutex_exit(&dn->dn_mtx);
2348 }
2349
2350 /*
2351 * Scans a block at the indicated "level" looking for a hole or data,
2352 * depending on 'flags'.
2353 *
2354 * If level > 0, then we are scanning an indirect block looking at its
2355 * pointers. If level == 0, then we are looking at a block of dnodes.
2356 *
2357 * If we don't find what we are looking for in the block, we return ESRCH.
2358 * Otherwise, return with *offset pointing to the beginning (if searching
2359 * forwards) or end (if searching backwards) of the range covered by the
2360 * block pointer we matched on (or dnode).
2361 *
2362 * The basic search algorithm used below by dnode_next_offset() is to
2363 * use this function to search up the block tree (widen the search) until
2364 * we find something (i.e., we don't return ESRCH) and then search back
2365 * down the tree (narrow the search) until we reach our original search
2366 * level.
2367 */
2368 static int
2369 dnode_next_offset_level(dnode_t *dn, int flags, uint64_t *offset,
2370 int lvl, uint64_t blkfill, uint64_t txg)
2371 {
2372 dmu_buf_impl_t *db = NULL;
2373 void *data = NULL;
2374 uint64_t epbs = dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT;
2375 uint64_t epb = 1ULL << epbs;
2376 uint64_t minfill, maxfill;
2377 boolean_t hole;
2378 int i, inc, error, span;
2379
2380 ASSERT(RW_LOCK_HELD(&dn->dn_struct_rwlock));
2381
2382 hole = ((flags & DNODE_FIND_HOLE) != 0);
2383 inc = (flags & DNODE_FIND_BACKWARDS) ? -1 : 1;
2384 ASSERT(txg == 0 || !hole);
2385
2386 if (lvl == dn->dn_phys->dn_nlevels) {
2387 error = 0;
2388 epb = dn->dn_phys->dn_nblkptr;
2389 data = dn->dn_phys->dn_blkptr;
2390 } else {
2391 uint64_t blkid = dbuf_whichblock(dn, lvl, *offset);
2392 error = dbuf_hold_impl(dn, lvl, blkid, TRUE, FALSE, FTAG, &db);
2393 if (error) {
2394 if (error != ENOENT)
2395 return (error);
2396 if (hole)
2397 return (0);
2398 /*
2399 * This can only happen when we are searching up
2400 * the block tree for data. We don't really need to
2401 * adjust the offset, as we will just end up looking
2402 * at the pointer to this block in its parent, and its
2403 * going to be unallocated, so we will skip over it.
2404 */
2405 return (SET_ERROR(ESRCH));
2406 }
2407 error = dbuf_read(db, NULL,
2408 DB_RF_CANFAIL | DB_RF_HAVESTRUCT |
2409 DB_RF_NO_DECRYPT | DB_RF_NOPREFETCH);
2410 if (error) {
2411 dbuf_rele(db, FTAG);
2412 return (error);
2413 }
2414 data = db->db.db_data;
2415 rw_enter(&db->db_rwlock, RW_READER);
2416 }
2417
2418 if (db != NULL && txg != 0 && (db->db_blkptr == NULL ||
2419 db->db_blkptr->blk_birth <= txg ||
2420 BP_IS_HOLE(db->db_blkptr))) {
2421 /*
2422 * This can only happen when we are searching up the tree
2423 * and these conditions mean that we need to keep climbing.
2424 */
2425 error = SET_ERROR(ESRCH);
2426 } else if (lvl == 0) {
2427 dnode_phys_t *dnp = data;
2428
2429 ASSERT(dn->dn_type == DMU_OT_DNODE);
2430 ASSERT(!(flags & DNODE_FIND_BACKWARDS));
2431
2432 for (i = (*offset >> DNODE_SHIFT) & (blkfill - 1);
2433 i < blkfill; i += dnp[i].dn_extra_slots + 1) {
2434 if ((dnp[i].dn_type == DMU_OT_NONE) == hole)
2435 break;
2436 }
2437
2438 if (i == blkfill)
2439 error = SET_ERROR(ESRCH);
2440
2441 *offset = (*offset & ~(DNODE_BLOCK_SIZE - 1)) +
2442 (i << DNODE_SHIFT);
2443 } else {
2444 blkptr_t *bp = data;
2445 uint64_t start = *offset;
2446 span = (lvl - 1) * epbs + dn->dn_datablkshift;
2447 minfill = 0;
2448 maxfill = blkfill << ((lvl - 1) * epbs);
2449
2450 if (hole)
2451 maxfill--;
2452 else
2453 minfill++;
2454
2455 if (span >= 8 * sizeof (*offset)) {
2456 /* This only happens on the highest indirection level */
2457 ASSERT3U((lvl - 1), ==, dn->dn_phys->dn_nlevels - 1);
2458 *offset = 0;
2459 } else {
2460 *offset = *offset >> span;
2461 }
2462
2463 for (i = BF64_GET(*offset, 0, epbs);
2464 i >= 0 && i < epb; i += inc) {
2465 if (BP_GET_FILL(&bp[i]) >= minfill &&
2466 BP_GET_FILL(&bp[i]) <= maxfill &&
2467 (hole || bp[i].blk_birth > txg))
2468 break;
2469 if (inc > 0 || *offset > 0)
2470 *offset += inc;
2471 }
2472
2473 if (span >= 8 * sizeof (*offset)) {
2474 *offset = start;
2475 } else {
2476 *offset = *offset << span;
2477 }
2478
2479 if (inc < 0) {
2480 /* traversing backwards; position offset at the end */
2481 ASSERT3U(*offset, <=, start);
2482 *offset = MIN(*offset + (1ULL << span) - 1, start);
2483 } else if (*offset < start) {
2484 *offset = start;
2485 }
2486 if (i < 0 || i >= epb)
2487 error = SET_ERROR(ESRCH);
2488 }
2489
2490 if (db != NULL) {
2491 rw_exit(&db->db_rwlock);
2492 dbuf_rele(db, FTAG);
2493 }
2494
2495 return (error);
2496 }
2497
2498 /*
2499 * Find the next hole, data, or sparse region at or after *offset.
2500 * The value 'blkfill' tells us how many items we expect to find
2501 * in an L0 data block; this value is 1 for normal objects,
2502 * DNODES_PER_BLOCK for the meta dnode, and some fraction of
2503 * DNODES_PER_BLOCK when searching for sparse regions thereof.
2504 *
2505 * Examples:
2506 *
2507 * dnode_next_offset(dn, flags, offset, 1, 1, 0);
2508 * Finds the next/previous hole/data in a file.
2509 * Used in dmu_offset_next().
2510 *
2511 * dnode_next_offset(mdn, flags, offset, 0, DNODES_PER_BLOCK, txg);
2512 * Finds the next free/allocated dnode an objset's meta-dnode.
2513 * Only finds objects that have new contents since txg (ie.
2514 * bonus buffer changes and content removal are ignored).
2515 * Used in dmu_object_next().
2516 *
2517 * dnode_next_offset(mdn, DNODE_FIND_HOLE, offset, 2, DNODES_PER_BLOCK >> 2, 0);
2518 * Finds the next L2 meta-dnode bp that's at most 1/4 full.
2519 * Used in dmu_object_alloc().
2520 */
2521 int
2522 dnode_next_offset(dnode_t *dn, int flags, uint64_t *offset,
2523 int minlvl, uint64_t blkfill, uint64_t txg)
2524 {
2525 uint64_t initial_offset = *offset;
2526 int lvl, maxlvl;
2527 int error = 0;
2528
2529 if (!(flags & DNODE_FIND_HAVELOCK))
2530 rw_enter(&dn->dn_struct_rwlock, RW_READER);
2531
2532 if (dn->dn_phys->dn_nlevels == 0) {
2533 error = SET_ERROR(ESRCH);
2534 goto out;
2535 }
2536
2537 if (dn->dn_datablkshift == 0) {
2538 if (*offset < dn->dn_datablksz) {
2539 if (flags & DNODE_FIND_HOLE)
2540 *offset = dn->dn_datablksz;
2541 } else {
2542 error = SET_ERROR(ESRCH);
2543 }
2544 goto out;
2545 }
2546
2547 maxlvl = dn->dn_phys->dn_nlevels;
2548
2549 for (lvl = minlvl; lvl <= maxlvl; lvl++) {
2550 error = dnode_next_offset_level(dn,
2551 flags, offset, lvl, blkfill, txg);
2552 if (error != ESRCH)
2553 break;
2554 }
2555
2556 while (error == 0 && --lvl >= minlvl) {
2557 error = dnode_next_offset_level(dn,
2558 flags, offset, lvl, blkfill, txg);
2559 }
2560
2561 /*
2562 * There's always a "virtual hole" at the end of the object, even
2563 * if all BP's which physically exist are non-holes.
2564 */
2565 if ((flags & DNODE_FIND_HOLE) && error == ESRCH && txg == 0 &&
2566 minlvl == 1 && blkfill == 1 && !(flags & DNODE_FIND_BACKWARDS)) {
2567 error = 0;
2568 }
2569
2570 if (error == 0 && (flags & DNODE_FIND_BACKWARDS ?
2571 initial_offset < *offset : initial_offset > *offset))
2572 error = SET_ERROR(ESRCH);
2573 out:
2574 if (!(flags & DNODE_FIND_HAVELOCK))
2575 rw_exit(&dn->dn_struct_rwlock);
2576
2577 return (error);
2578 }
2579
2580 #if defined(_KERNEL)
2581 EXPORT_SYMBOL(dnode_hold);
2582 EXPORT_SYMBOL(dnode_rele);
2583 EXPORT_SYMBOL(dnode_set_nlevels);
2584 EXPORT_SYMBOL(dnode_set_blksz);
2585 EXPORT_SYMBOL(dnode_free_range);
2586 EXPORT_SYMBOL(dnode_evict_dbufs);
2587 EXPORT_SYMBOL(dnode_evict_bonus);
2588 #endif
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