1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21 /*
22 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
23 * Copyright (c) 2012, 2017 by Delphix. All rights reserved.
24 * Copyright (c) 2014 Spectra Logic Corporation, All rights reserved.
25 * Copyright (c) 2014 Integros [integros.com]
26 * Copyright 2017 RackTop Systems.
27 */
28
29 #include <sys/zfs_context.h>
30 #include <sys/dbuf.h>
31 #include <sys/dnode.h>
32 #include <sys/dmu.h>
33 #include <sys/dmu_impl.h>
34 #include <sys/dmu_tx.h>
35 #include <sys/dmu_objset.h>
36 #include <sys/dsl_dir.h>
37 #include <sys/dsl_dataset.h>
38 #include <sys/spa.h>
39 #include <sys/zio.h>
40 #include <sys/dmu_zfetch.h>
41 #include <sys/range_tree.h>
42 #include <sys/zfs_project.h>
43
44 dnode_stats_t dnode_stats = {
45 { "dnode_hold_dbuf_hold", KSTAT_DATA_UINT64 },
46 { "dnode_hold_dbuf_read", KSTAT_DATA_UINT64 },
47 { "dnode_hold_alloc_hits", KSTAT_DATA_UINT64 },
48 { "dnode_hold_alloc_misses", KSTAT_DATA_UINT64 },
49 { "dnode_hold_alloc_interior", KSTAT_DATA_UINT64 },
50 { "dnode_hold_alloc_lock_retry", KSTAT_DATA_UINT64 },
51 { "dnode_hold_alloc_lock_misses", KSTAT_DATA_UINT64 },
52 { "dnode_hold_alloc_type_none", KSTAT_DATA_UINT64 },
53 { "dnode_hold_free_hits", KSTAT_DATA_UINT64 },
54 { "dnode_hold_free_misses", KSTAT_DATA_UINT64 },
55 { "dnode_hold_free_lock_misses", KSTAT_DATA_UINT64 },
56 { "dnode_hold_free_lock_retry", KSTAT_DATA_UINT64 },
57 { "dnode_hold_free_overflow", KSTAT_DATA_UINT64 },
58 { "dnode_hold_free_refcount", KSTAT_DATA_UINT64 },
59 { "dnode_free_interior_lock_retry", KSTAT_DATA_UINT64 },
60 { "dnode_allocate", KSTAT_DATA_UINT64 },
61 { "dnode_reallocate", KSTAT_DATA_UINT64 },
62 { "dnode_buf_evict", KSTAT_DATA_UINT64 },
63 { "dnode_alloc_next_chunk", KSTAT_DATA_UINT64 },
64 { "dnode_alloc_race", KSTAT_DATA_UINT64 },
65 { "dnode_alloc_next_block", KSTAT_DATA_UINT64 },
66 { "dnode_move_invalid", KSTAT_DATA_UINT64 },
67 { "dnode_move_recheck1", KSTAT_DATA_UINT64 },
68 { "dnode_move_recheck2", KSTAT_DATA_UINT64 },
69 { "dnode_move_special", KSTAT_DATA_UINT64 },
70 { "dnode_move_handle", KSTAT_DATA_UINT64 },
71 { "dnode_move_rwlock", KSTAT_DATA_UINT64 },
72 { "dnode_move_active", KSTAT_DATA_UINT64 },
73 };
74
75 static kstat_t *dnode_ksp;
76 static kmem_cache_t *dnode_cache;
77
78 static dnode_phys_t dnode_phys_zero;
79
80 int zfs_default_bs = SPA_MINBLOCKSHIFT;
81 int zfs_default_ibs = DN_MAX_INDBLKSHIFT;
82
83 #ifdef _KERNEL
84 static kmem_cbrc_t dnode_move(void *, void *, size_t, void *);
85 #endif /* _KERNEL */
86
87 static int
88 dbuf_compare(const void *x1, const void *x2)
89 {
90 const dmu_buf_impl_t *d1 = x1;
91 const dmu_buf_impl_t *d2 = x2;
92
93 int cmp = AVL_CMP(d1->db_level, d2->db_level);
94 if (likely(cmp))
95 return (cmp);
96
97 cmp = AVL_CMP(d1->db_blkid, d2->db_blkid);
98 if (likely(cmp))
99 return (cmp);
100
101 if (d1->db_state == DB_SEARCH) {
102 ASSERT3S(d2->db_state, !=, DB_SEARCH);
103 return (-1);
104 } else if (d2->db_state == DB_SEARCH) {
105 ASSERT3S(d1->db_state, !=, DB_SEARCH);
106 return (1);
107 }
108
109 return (AVL_PCMP(d1, d2));
110 }
111
112 /* ARGSUSED */
113 static int
114 dnode_cons(void *arg, void *unused, int kmflag)
115 {
116 dnode_t *dn = arg;
117 int i;
118
119 rw_init(&dn->dn_struct_rwlock, NULL, RW_DEFAULT, 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
124 /*
125 * Every dbuf has a reference, and dropping a tracked reference is
126 * O(number of references), so don't track dn_holds.
127 */
128 zfs_refcount_create_untracked(&dn->dn_holds);
129 zfs_refcount_create(&dn->dn_tx_holds);
130 list_link_init(&dn->dn_link);
131
132 bzero(&dn->dn_next_nblkptr[0], sizeof (dn->dn_next_nblkptr));
133 bzero(&dn->dn_next_nlevels[0], sizeof (dn->dn_next_nlevels));
134 bzero(&dn->dn_next_indblkshift[0], sizeof (dn->dn_next_indblkshift));
135 bzero(&dn->dn_next_bonustype[0], sizeof (dn->dn_next_bonustype));
136 bzero(&dn->dn_rm_spillblk[0], sizeof (dn->dn_rm_spillblk));
137 bzero(&dn->dn_next_bonuslen[0], sizeof (dn->dn_next_bonuslen));
138 bzero(&dn->dn_next_blksz[0], sizeof (dn->dn_next_blksz));
139 bzero(&dn->dn_next_maxblkid[0], sizeof (dn->dn_next_maxblkid));
140
141 for (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 /* ARGSUSED */
177 static void
178 dnode_dest(void *arg, void *unused)
179 {
180 int i;
181 dnode_t *dn = arg;
182
183 rw_destroy(&dn->dn_struct_rwlock);
184 mutex_destroy(&dn->dn_mtx);
185 mutex_destroy(&dn->dn_dbufs_mtx);
186 cv_destroy(&dn->dn_notxholds);
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 (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",
233 sizeof (dnode_t),
234 0, dnode_cons, dnode_dest, NULL, NULL, NULL, 0);
235 #ifdef _KERNEL
236 kmem_cache_set_move(dnode_cache, dnode_move);
237
238 dnode_ksp = kstat_create("zfs", 0, "dnodestats", "misc",
239 KSTAT_TYPE_NAMED, sizeof (dnode_stats) / sizeof (kstat_named_t),
240 KSTAT_FLAG_VIRTUAL);
241 if (dnode_ksp != NULL) {
242 dnode_ksp->ks_data = &dnode_stats;
243 kstat_install(dnode_ksp);
244 }
245 #endif /* _KERNEL */
246 }
247
248 void
249 dnode_fini(void)
250 {
251 if (dnode_ksp != NULL) {
252 kstat_delete(dnode_ksp);
253 dnode_ksp = NULL;
254 }
255
256 kmem_cache_destroy(dnode_cache);
257 dnode_cache = NULL;
258 }
259
260
261 #ifdef ZFS_DEBUG
262 void
263 dnode_verify(dnode_t *dn)
264 {
265 int drop_struct_lock = FALSE;
266
267 ASSERT(dn->dn_phys);
268 ASSERT(dn->dn_objset);
269 ASSERT(dn->dn_handle->dnh_dnode == dn);
270
271 ASSERT(DMU_OT_IS_VALID(dn->dn_phys->dn_type));
272
273 if (!(zfs_flags & ZFS_DEBUG_DNODE_VERIFY))
274 return;
275
276 if (!RW_WRITE_HELD(&dn->dn_struct_rwlock)) {
277 rw_enter(&dn->dn_struct_rwlock, RW_READER);
278 drop_struct_lock = TRUE;
279 }
280 if (dn->dn_phys->dn_type != DMU_OT_NONE || dn->dn_allocated_txg != 0) {
281 int i;
282 int max_bonuslen = DN_SLOTS_TO_BONUSLEN(dn->dn_num_slots);
283 ASSERT3U(dn->dn_indblkshift, >=, 0);
284 ASSERT3U(dn->dn_indblkshift, <=, SPA_MAXBLOCKSHIFT);
285 if (dn->dn_datablkshift) {
286 ASSERT3U(dn->dn_datablkshift, >=, SPA_MINBLOCKSHIFT);
287 ASSERT3U(dn->dn_datablkshift, <=, SPA_MAXBLOCKSHIFT);
288 ASSERT3U(1<<dn->dn_datablkshift, ==, dn->dn_datablksz);
289 }
290 ASSERT3U(dn->dn_nlevels, <=, 30);
291 ASSERT(DMU_OT_IS_VALID(dn->dn_type));
292 ASSERT3U(dn->dn_nblkptr, >=, 1);
293 ASSERT3U(dn->dn_nblkptr, <=, DN_MAX_NBLKPTR);
294 ASSERT3U(dn->dn_bonuslen, <=, max_bonuslen);
295 ASSERT3U(dn->dn_datablksz, ==,
296 dn->dn_datablkszsec << SPA_MINBLOCKSHIFT);
297 ASSERT3U(ISP2(dn->dn_datablksz), ==, dn->dn_datablkshift != 0);
298 ASSERT3U((dn->dn_nblkptr - 1) * sizeof (blkptr_t) +
299 dn->dn_bonuslen, <=, max_bonuslen);
300 for (i = 0; i < TXG_SIZE; i++) {
301 ASSERT3U(dn->dn_next_nlevels[i], <=, dn->dn_nlevels);
302 }
303 }
304 if (dn->dn_phys->dn_type != DMU_OT_NONE)
305 ASSERT3U(dn->dn_phys->dn_nlevels, <=, dn->dn_nlevels);
306 ASSERT(DMU_OBJECT_IS_SPECIAL(dn->dn_object) || dn->dn_dbuf != NULL);
307 if (dn->dn_dbuf != NULL) {
308 ASSERT3P(dn->dn_phys, ==,
309 (dnode_phys_t *)dn->dn_dbuf->db.db_data +
310 (dn->dn_object % (dn->dn_dbuf->db.db_size >> DNODE_SHIFT)));
311 }
312 if (drop_struct_lock)
313 rw_exit(&dn->dn_struct_rwlock);
314 }
315 #endif
316
317 void
318 dnode_byteswap(dnode_phys_t *dnp)
319 {
320 uint64_t *buf64 = (void*)&dnp->dn_blkptr;
321 int i;
322
323 if (dnp->dn_type == DMU_OT_NONE) {
324 bzero(dnp, sizeof (dnode_phys_t));
325 return;
326 }
327
328 dnp->dn_datablkszsec = BSWAP_16(dnp->dn_datablkszsec);
329 dnp->dn_bonuslen = BSWAP_16(dnp->dn_bonuslen);
330 dnp->dn_extra_slots = BSWAP_8(dnp->dn_extra_slots);
331 dnp->dn_maxblkid = BSWAP_64(dnp->dn_maxblkid);
332 dnp->dn_used = BSWAP_64(dnp->dn_used);
333
334 /*
335 * dn_nblkptr is only one byte, so it's OK to read it in either
336 * byte order. We can't read dn_bouslen.
337 */
338 ASSERT(dnp->dn_indblkshift <= SPA_MAXBLOCKSHIFT);
339 ASSERT(dnp->dn_nblkptr <= DN_MAX_NBLKPTR);
340 for (i = 0; i < dnp->dn_nblkptr * sizeof (blkptr_t)/8; i++)
341 buf64[i] = BSWAP_64(buf64[i]);
342
343 /*
344 * OK to check dn_bonuslen for zero, because it won't matter if
345 * we have the wrong byte order. This is necessary because the
346 * dnode dnode is smaller than a regular dnode.
347 */
348 if (dnp->dn_bonuslen != 0) {
349 /*
350 * Note that the bonus length calculated here may be
351 * longer than the actual bonus buffer. This is because
352 * we always put the bonus buffer after the last block
353 * pointer (instead of packing it against the end of the
354 * dnode buffer).
355 */
356 int off = (dnp->dn_nblkptr-1) * sizeof (blkptr_t);
357 int slots = dnp->dn_extra_slots + 1;
358 size_t len = DN_SLOTS_TO_BONUSLEN(slots) - off;
359 ASSERT(DMU_OT_IS_VALID(dnp->dn_bonustype));
360 dmu_object_byteswap_t byteswap =
361 DMU_OT_BYTESWAP(dnp->dn_bonustype);
362 dmu_ot_byteswap[byteswap].ob_func(dnp->dn_bonus + off, len);
363 }
364
365 /* Swap SPILL block if we have one */
366 if (dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR)
367 byteswap_uint64_array(DN_SPILL_BLKPTR(dnp), sizeof (blkptr_t));
368
369 }
370
371 void
372 dnode_buf_byteswap(void *vbuf, size_t size)
373 {
374 int i = 0;
375
376 ASSERT3U(sizeof (dnode_phys_t), ==, (1<<DNODE_SHIFT));
377 ASSERT((size & (sizeof (dnode_phys_t)-1)) == 0);
378
379 while (i < size) {
380 dnode_phys_t *dnp = (void *)(((char *)vbuf) + i);
381 dnode_byteswap(dnp);
382
383 i += DNODE_MIN_SIZE;
384 if (dnp->dn_type != DMU_OT_NONE)
385 i += dnp->dn_extra_slots * DNODE_MIN_SIZE;
386 }
387 }
388
389 void
390 dnode_setbonuslen(dnode_t *dn, int newsize, dmu_tx_t *tx)
391 {
392 ASSERT3U(zfs_refcount_count(&dn->dn_holds), >=, 1);
393
394 dnode_setdirty(dn, tx);
395 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
396 ASSERT3U(newsize, <=, DN_SLOTS_TO_BONUSLEN(dn->dn_num_slots) -
397 (dn->dn_nblkptr-1) * sizeof (blkptr_t));
398 dn->dn_bonuslen = newsize;
399 if (newsize == 0)
400 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = DN_ZERO_BONUSLEN;
401 else
402 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = dn->dn_bonuslen;
403 rw_exit(&dn->dn_struct_rwlock);
404 }
405
406 void
407 dnode_setbonus_type(dnode_t *dn, dmu_object_type_t newtype, dmu_tx_t *tx)
408 {
409 ASSERT3U(zfs_refcount_count(&dn->dn_holds), >=, 1);
410 dnode_setdirty(dn, tx);
411 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
412 dn->dn_bonustype = newtype;
413 dn->dn_next_bonustype[tx->tx_txg & TXG_MASK] = dn->dn_bonustype;
414 rw_exit(&dn->dn_struct_rwlock);
415 }
416
417 void
418 dnode_rm_spill(dnode_t *dn, dmu_tx_t *tx)
419 {
420 ASSERT3U(zfs_refcount_count(&dn->dn_holds), >=, 1);
421 ASSERT(RW_WRITE_HELD(&dn->dn_struct_rwlock));
422 dnode_setdirty(dn, tx);
423 dn->dn_rm_spillblk[tx->tx_txg&TXG_MASK] = DN_KILL_SPILLBLK;
424 dn->dn_have_spill = B_FALSE;
425 }
426
427 static void
428 dnode_setdblksz(dnode_t *dn, int size)
429 {
430 ASSERT0(P2PHASE(size, SPA_MINBLOCKSIZE));
431 ASSERT3U(size, <=, SPA_MAXBLOCKSIZE);
432 ASSERT3U(size, >=, SPA_MINBLOCKSIZE);
433 ASSERT3U(size >> SPA_MINBLOCKSHIFT, <,
434 1<<(sizeof (dn->dn_phys->dn_datablkszsec) * 8));
435 dn->dn_datablksz = size;
436 dn->dn_datablkszsec = size >> SPA_MINBLOCKSHIFT;
437 dn->dn_datablkshift = ISP2(size) ? highbit64(size - 1) : 0;
438 }
439
440 static dnode_t *
441 dnode_create(objset_t *os, dnode_phys_t *dnp, dmu_buf_impl_t *db,
442 uint64_t object, dnode_handle_t *dnh)
443 {
444 dnode_t *dn;
445
446 dn = kmem_cache_alloc(dnode_cache, KM_SLEEP);
447 #ifdef _KERNEL
448 ASSERT(!POINTER_IS_VALID(dn->dn_objset));
449 #endif /* _KERNEL */
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_OTHER);
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 if (dn->dn_dirtyctx_firstset != NULL) {
546 kmem_free(dn->dn_dirtyctx_firstset, 1);
547 dn->dn_dirtyctx_firstset = NULL;
548 }
549 if (dn->dn_bonus != NULL) {
550 mutex_enter(&dn->dn_bonus->db_mtx);
551 dbuf_destroy(dn->dn_bonus);
552 dn->dn_bonus = NULL;
553 }
554 dn->dn_zio = NULL;
555
556 dn->dn_have_spill = B_FALSE;
557 dn->dn_oldused = 0;
558 dn->dn_oldflags = 0;
559 dn->dn_olduid = 0;
560 dn->dn_oldgid = 0;
561 dn->dn_oldprojid = ZFS_DEFAULT_PROJID;
562 dn->dn_newuid = 0;
563 dn->dn_newgid = 0;
564 dn->dn_newprojid = ZFS_DEFAULT_PROJID;
565 dn->dn_id_flags = 0;
566
567 dmu_zfetch_fini(&dn->dn_zfetch);
568 kmem_cache_free(dnode_cache, dn);
569 arc_space_return(sizeof (dnode_t), ARC_SPACE_OTHER);
570
571 if (complete_os_eviction)
572 dmu_objset_evict_done(os);
573 }
574
575 void
576 dnode_allocate(dnode_t *dn, dmu_object_type_t ot, int blocksize, int ibs,
577 dmu_object_type_t bonustype, int bonuslen, int dn_slots, dmu_tx_t *tx)
578 {
579 int i;
580
581 ASSERT3U(dn_slots, >, 0);
582 ASSERT3U(dn_slots << DNODE_SHIFT, <=,
583 spa_maxdnodesize(dmu_objset_spa(dn->dn_objset)));
584 ASSERT3U(blocksize, <=,
585 spa_maxblocksize(dmu_objset_spa(dn->dn_objset)));
586 if (blocksize == 0)
587 blocksize = 1 << zfs_default_bs;
588 else
589 blocksize = P2ROUNDUP(blocksize, SPA_MINBLOCKSIZE);
590
591 if (ibs == 0)
592 ibs = zfs_default_ibs;
593
594 ibs = MIN(MAX(ibs, DN_MIN_INDBLKSHIFT), DN_MAX_INDBLKSHIFT);
595
596 dprintf("os=%p obj=%" PRIu64 " txg=%" PRIu64
597 " blocksize=%d ibs=%d dn_slots=%d\n",
598 dn->dn_objset, dn->dn_object, tx->tx_txg, blocksize, ibs, dn_slots);
599 DNODE_STAT_BUMP(dnode_allocate);
600
601 ASSERT(dn->dn_type == DMU_OT_NONE);
602 ASSERT(bcmp(dn->dn_phys, &dnode_phys_zero, sizeof (dnode_phys_t)) == 0);
603 ASSERT(dn->dn_phys->dn_type == DMU_OT_NONE);
604 ASSERT(ot != DMU_OT_NONE);
605 ASSERT(DMU_OT_IS_VALID(ot));
606 ASSERT((bonustype == DMU_OT_NONE && bonuslen == 0) ||
607 (bonustype == DMU_OT_SA && bonuslen == 0) ||
608 (bonustype != DMU_OT_NONE && bonuslen != 0));
609 ASSERT(DMU_OT_IS_VALID(bonustype));
610 ASSERT3U(bonuslen, <=, DN_SLOTS_TO_BONUSLEN(dn_slots));
611 ASSERT(dn->dn_type == DMU_OT_NONE);
612 ASSERT0(dn->dn_maxblkid);
613 ASSERT0(dn->dn_allocated_txg);
614 ASSERT0(dn->dn_dirty_txg);
615 ASSERT0(dn->dn_assigned_txg);
616 ASSERT(zfs_refcount_is_zero(&dn->dn_tx_holds));
617 ASSERT3U(zfs_refcount_count(&dn->dn_holds), <=, 1);
618 ASSERT(avl_is_empty(&dn->dn_dbufs));
619
620 for (i = 0; i < TXG_SIZE; i++) {
621 ASSERT0(dn->dn_next_nblkptr[i]);
622 ASSERT0(dn->dn_next_nlevels[i]);
623 ASSERT0(dn->dn_next_indblkshift[i]);
624 ASSERT0(dn->dn_next_bonuslen[i]);
625 ASSERT0(dn->dn_next_bonustype[i]);
626 ASSERT0(dn->dn_rm_spillblk[i]);
627 ASSERT0(dn->dn_next_blksz[i]);
628 ASSERT0(dn->dn_next_maxblkid[i]);
629 ASSERT(!multilist_link_active(&dn->dn_dirty_link[i]));
630 ASSERT3P(list_head(&dn->dn_dirty_records[i]), ==, NULL);
631 ASSERT3P(dn->dn_free_ranges[i], ==, NULL);
632 }
633
634 dn->dn_type = ot;
635 dnode_setdblksz(dn, blocksize);
636 dn->dn_indblkshift = ibs;
637 dn->dn_nlevels = 1;
638 dn->dn_num_slots = dn_slots;
639 if (bonustype == DMU_OT_SA) /* Maximize bonus space for SA */
640 dn->dn_nblkptr = 1;
641 else {
642 dn->dn_nblkptr = MIN(DN_MAX_NBLKPTR,
643 1 + ((DN_SLOTS_TO_BONUSLEN(dn_slots) - bonuslen) >>
644 SPA_BLKPTRSHIFT));
645 }
646
647 dn->dn_bonustype = bonustype;
648 dn->dn_bonuslen = bonuslen;
649 dn->dn_checksum = ZIO_CHECKSUM_INHERIT;
650 dn->dn_compress = ZIO_COMPRESS_INHERIT;
651 dn->dn_dirtyctx = 0;
652
653 dn->dn_free_txg = 0;
654 if (dn->dn_dirtyctx_firstset) {
655 kmem_free(dn->dn_dirtyctx_firstset, 1);
656 dn->dn_dirtyctx_firstset = NULL;
657 }
658
659 dn->dn_allocated_txg = tx->tx_txg;
660 dn->dn_id_flags = 0;
661
662 dnode_setdirty(dn, tx);
663 dn->dn_next_indblkshift[tx->tx_txg & TXG_MASK] = ibs;
664 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = dn->dn_bonuslen;
665 dn->dn_next_bonustype[tx->tx_txg & TXG_MASK] = dn->dn_bonustype;
666 dn->dn_next_blksz[tx->tx_txg & TXG_MASK] = dn->dn_datablksz;
667 }
668
669 void
670 dnode_reallocate(dnode_t *dn, dmu_object_type_t ot, int blocksize,
671 dmu_object_type_t bonustype, int bonuslen, int dn_slots,
672 boolean_t keep_spill, dmu_tx_t *tx)
673 {
674 int nblkptr;
675
676 ASSERT3U(blocksize, >=, SPA_MINBLOCKSIZE);
677 ASSERT3U(blocksize, <=,
678 spa_maxblocksize(dmu_objset_spa(dn->dn_objset)));
679 ASSERT0(blocksize % SPA_MINBLOCKSIZE);
680 ASSERT(dn->dn_object != DMU_META_DNODE_OBJECT || dmu_tx_private_ok(tx));
681 ASSERT(tx->tx_txg != 0);
682 ASSERT((bonustype == DMU_OT_NONE && bonuslen == 0) ||
683 (bonustype != DMU_OT_NONE && bonuslen != 0) ||
684 (bonustype == DMU_OT_SA && bonuslen == 0));
685 ASSERT(DMU_OT_IS_VALID(bonustype));
686 ASSERT3U(bonuslen, <=,
687 DN_BONUS_SIZE(spa_maxdnodesize(dmu_objset_spa(dn->dn_objset))));
688 ASSERT3U(bonuslen, <=, DN_BONUS_SIZE(dn_slots << DNODE_SHIFT));
689
690 dnode_free_interior_slots(dn);
691 DNODE_STAT_BUMP(dnode_reallocate);
692
693 /* clean up any unreferenced dbufs */
694 dnode_evict_dbufs(dn);
695
696 dn->dn_id_flags = 0;
697
698 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
699 dnode_setdirty(dn, tx);
700 if (dn->dn_datablksz != blocksize) {
701 /* change blocksize */
702 ASSERT(dn->dn_maxblkid == 0 &&
703 (BP_IS_HOLE(&dn->dn_phys->dn_blkptr[0]) ||
704 dnode_block_freed(dn, 0)));
705 dnode_setdblksz(dn, blocksize);
706 dn->dn_next_blksz[tx->tx_txg&TXG_MASK] = blocksize;
707 }
708 if (dn->dn_bonuslen != bonuslen)
709 dn->dn_next_bonuslen[tx->tx_txg&TXG_MASK] = bonuslen;
710
711 if (bonustype == DMU_OT_SA) /* Maximize bonus space for SA */
712 nblkptr = 1;
713 else
714 nblkptr = MIN(DN_MAX_NBLKPTR,
715 1 + ((DN_SLOTS_TO_BONUSLEN(dn_slots) - bonuslen) >>
716 SPA_BLKPTRSHIFT));
717 if (dn->dn_bonustype != bonustype)
718 dn->dn_next_bonustype[tx->tx_txg&TXG_MASK] = bonustype;
719 if (dn->dn_nblkptr != nblkptr)
720 dn->dn_next_nblkptr[tx->tx_txg&TXG_MASK] = nblkptr;
721 if (dn->dn_phys->dn_flags & DNODE_FLAG_SPILL_BLKPTR && !keep_spill) {
722 dbuf_rm_spill(dn, tx);
723 dnode_rm_spill(dn, tx);
724 }
725 rw_exit(&dn->dn_struct_rwlock);
726
727 /* change type */
728 dn->dn_type = ot;
729
730 /* change bonus size and type */
731 mutex_enter(&dn->dn_mtx);
732 dn->dn_bonustype = bonustype;
733 dn->dn_bonuslen = bonuslen;
734 dn->dn_num_slots = dn_slots;
735 dn->dn_nblkptr = nblkptr;
736 dn->dn_checksum = ZIO_CHECKSUM_INHERIT;
737 dn->dn_compress = ZIO_COMPRESS_INHERIT;
738 ASSERT3U(dn->dn_nblkptr, <=, DN_MAX_NBLKPTR);
739
740 /* fix up the bonus db_size */
741 if (dn->dn_bonus) {
742 dn->dn_bonus->db.db_size =
743 DN_SLOTS_TO_BONUSLEN(dn->dn_num_slots) -
744 (dn->dn_nblkptr - 1) * sizeof (blkptr_t);
745 ASSERT(dn->dn_bonuslen <= dn->dn_bonus->db.db_size);
746 }
747
748 dn->dn_allocated_txg = tx->tx_txg;
749 mutex_exit(&dn->dn_mtx);
750 }
751
752 #ifdef _KERNEL
753 static void
754 dnode_move_impl(dnode_t *odn, dnode_t *ndn)
755 {
756 int i;
757
758 ASSERT(!RW_LOCK_HELD(&odn->dn_struct_rwlock));
759 ASSERT(MUTEX_NOT_HELD(&odn->dn_mtx));
760 ASSERT(MUTEX_NOT_HELD(&odn->dn_dbufs_mtx));
761 ASSERT(!RW_LOCK_HELD(&odn->dn_zfetch.zf_rwlock));
762
763 /* Copy fields. */
764 ndn->dn_objset = odn->dn_objset;
765 ndn->dn_object = odn->dn_object;
766 ndn->dn_dbuf = odn->dn_dbuf;
767 ndn->dn_handle = odn->dn_handle;
768 ndn->dn_phys = odn->dn_phys;
769 ndn->dn_type = odn->dn_type;
770 ndn->dn_bonuslen = odn->dn_bonuslen;
771 ndn->dn_bonustype = odn->dn_bonustype;
772 ndn->dn_nblkptr = odn->dn_nblkptr;
773 ndn->dn_checksum = odn->dn_checksum;
774 ndn->dn_compress = odn->dn_compress;
775 ndn->dn_nlevels = odn->dn_nlevels;
776 ndn->dn_indblkshift = odn->dn_indblkshift;
777 ndn->dn_datablkshift = odn->dn_datablkshift;
778 ndn->dn_datablkszsec = odn->dn_datablkszsec;
779 ndn->dn_datablksz = odn->dn_datablksz;
780 ndn->dn_maxblkid = odn->dn_maxblkid;
781 ndn->dn_num_slots = odn->dn_num_slots;
782 bcopy(&odn->dn_next_type[0], &ndn->dn_next_type[0],
783 sizeof (odn->dn_next_type));
784 bcopy(&odn->dn_next_nblkptr[0], &ndn->dn_next_nblkptr[0],
785 sizeof (odn->dn_next_nblkptr));
786 bcopy(&odn->dn_next_nlevels[0], &ndn->dn_next_nlevels[0],
787 sizeof (odn->dn_next_nlevels));
788 bcopy(&odn->dn_next_indblkshift[0], &ndn->dn_next_indblkshift[0],
789 sizeof (odn->dn_next_indblkshift));
790 bcopy(&odn->dn_next_bonustype[0], &ndn->dn_next_bonustype[0],
791 sizeof (odn->dn_next_bonustype));
792 bcopy(&odn->dn_rm_spillblk[0], &ndn->dn_rm_spillblk[0],
793 sizeof (odn->dn_rm_spillblk));
794 bcopy(&odn->dn_next_bonuslen[0], &ndn->dn_next_bonuslen[0],
795 sizeof (odn->dn_next_bonuslen));
796 bcopy(&odn->dn_next_blksz[0], &ndn->dn_next_blksz[0],
797 sizeof (odn->dn_next_blksz));
798 bcopy(&odn->dn_next_maxblkid[0], &ndn->dn_next_maxblkid[0],
799 sizeof (odn->dn_next_maxblkid));
800 for (i = 0; i < TXG_SIZE; i++) {
801 list_move_tail(&ndn->dn_dirty_records[i],
802 &odn->dn_dirty_records[i]);
803 }
804 bcopy(&odn->dn_free_ranges[0], &ndn->dn_free_ranges[0],
805 sizeof (odn->dn_free_ranges));
806 ndn->dn_allocated_txg = odn->dn_allocated_txg;
807 ndn->dn_free_txg = odn->dn_free_txg;
808 ndn->dn_assigned_txg = odn->dn_assigned_txg;
809 ndn->dn_dirty_txg = odn->dn_dirty_txg;
810 ndn->dn_dirtyctx = odn->dn_dirtyctx;
811 ndn->dn_dirtyctx_firstset = odn->dn_dirtyctx_firstset;
812 ASSERT(zfs_refcount_count(&odn->dn_tx_holds) == 0);
813 zfs_refcount_transfer(&ndn->dn_holds, &odn->dn_holds);
814 ASSERT(avl_is_empty(&ndn->dn_dbufs));
815 avl_swap(&ndn->dn_dbufs, &odn->dn_dbufs);
816 ndn->dn_dbufs_count = odn->dn_dbufs_count;
817 ndn->dn_bonus = odn->dn_bonus;
818 ndn->dn_have_spill = odn->dn_have_spill;
819 ndn->dn_zio = odn->dn_zio;
820 ndn->dn_oldused = odn->dn_oldused;
821 ndn->dn_oldflags = odn->dn_oldflags;
822 ndn->dn_olduid = odn->dn_olduid;
823 ndn->dn_oldgid = odn->dn_oldgid;
824 ndn->dn_oldprojid = odn->dn_oldprojid;
825 ndn->dn_newuid = odn->dn_newuid;
826 ndn->dn_newgid = odn->dn_newgid;
827 ndn->dn_newprojid = odn->dn_newprojid;
828 ndn->dn_id_flags = odn->dn_id_flags;
829 dmu_zfetch_init(&ndn->dn_zfetch, NULL);
830 list_move_tail(&ndn->dn_zfetch.zf_stream, &odn->dn_zfetch.zf_stream);
831 ndn->dn_zfetch.zf_dnode = odn->dn_zfetch.zf_dnode;
832
833 /*
834 * Update back pointers. Updating the handle fixes the back pointer of
835 * every descendant dbuf as well as the bonus dbuf.
836 */
837 ASSERT(ndn->dn_handle->dnh_dnode == odn);
838 ndn->dn_handle->dnh_dnode = ndn;
839 if (ndn->dn_zfetch.zf_dnode == odn) {
840 ndn->dn_zfetch.zf_dnode = ndn;
841 }
842
843 /*
844 * Invalidate the original dnode by clearing all of its back pointers.
845 */
846 odn->dn_dbuf = NULL;
847 odn->dn_handle = NULL;
848 avl_create(&odn->dn_dbufs, dbuf_compare, sizeof (dmu_buf_impl_t),
849 offsetof(dmu_buf_impl_t, db_link));
850 odn->dn_dbufs_count = 0;
851 odn->dn_bonus = NULL;
852 odn->dn_zfetch.zf_dnode = NULL;
853
854 /*
855 * Set the low bit of the objset pointer to ensure that dnode_move()
856 * recognizes the dnode as invalid in any subsequent callback.
857 */
858 POINTER_INVALIDATE(&odn->dn_objset);
859
860 /*
861 * Satisfy the destructor.
862 */
863 for (i = 0; i < TXG_SIZE; i++) {
864 list_create(&odn->dn_dirty_records[i],
865 sizeof (dbuf_dirty_record_t),
866 offsetof(dbuf_dirty_record_t, dr_dirty_node));
867 odn->dn_free_ranges[i] = NULL;
868 odn->dn_next_nlevels[i] = 0;
869 odn->dn_next_indblkshift[i] = 0;
870 odn->dn_next_bonustype[i] = 0;
871 odn->dn_rm_spillblk[i] = 0;
872 odn->dn_next_bonuslen[i] = 0;
873 odn->dn_next_blksz[i] = 0;
874 }
875 odn->dn_allocated_txg = 0;
876 odn->dn_free_txg = 0;
877 odn->dn_assigned_txg = 0;
878 odn->dn_dirty_txg = 0;
879 odn->dn_dirtyctx = 0;
880 odn->dn_dirtyctx_firstset = NULL;
881 odn->dn_have_spill = B_FALSE;
882 odn->dn_zio = NULL;
883 odn->dn_oldused = 0;
884 odn->dn_oldflags = 0;
885 odn->dn_olduid = 0;
886 odn->dn_oldgid = 0;
887 odn->dn_oldprojid = ZFS_DEFAULT_PROJID;
888 odn->dn_newuid = 0;
889 odn->dn_newgid = 0;
890 odn->dn_newprojid = ZFS_DEFAULT_PROJID;
891 odn->dn_id_flags = 0;
892
893 /*
894 * Mark the dnode.
895 */
896 ndn->dn_moved = 1;
897 odn->dn_moved = (uint8_t)-1;
898 }
899
900 /*ARGSUSED*/
901 static kmem_cbrc_t
902 dnode_move(void *buf, void *newbuf, size_t size, void *arg)
903 {
904 dnode_t *odn = buf, *ndn = newbuf;
905 objset_t *os;
906 int64_t refcount;
907 uint32_t dbufs;
908
909 /*
910 * The dnode is on the objset's list of known dnodes if the objset
911 * pointer is valid. We set the low bit of the objset pointer when
912 * freeing the dnode to invalidate it, and the memory patterns written
913 * by kmem (baddcafe and deadbeef) set at least one of the two low bits.
914 * A newly created dnode sets the objset pointer last of all to indicate
915 * that the dnode is known and in a valid state to be moved by this
916 * function.
917 */
918 os = odn->dn_objset;
919 if (!POINTER_IS_VALID(os)) {
920 DNODE_STAT_BUMP(dnode_move_invalid);
921 return (KMEM_CBRC_DONT_KNOW);
922 }
923
924 /*
925 * Ensure that the objset does not go away during the move.
926 */
927 rw_enter(&os_lock, RW_WRITER);
928 if (os != odn->dn_objset) {
929 rw_exit(&os_lock);
930 DNODE_STAT_BUMP(dnode_move_recheck1);
931 return (KMEM_CBRC_DONT_KNOW);
932 }
933
934 /*
935 * If the dnode is still valid, then so is the objset. We know that no
936 * valid objset can be freed while we hold os_lock, so we can safely
937 * ensure that the objset remains in use.
938 */
939 mutex_enter(&os->os_lock);
940
941 /*
942 * Recheck the objset pointer in case the dnode was removed just before
943 * acquiring the lock.
944 */
945 if (os != odn->dn_objset) {
946 mutex_exit(&os->os_lock);
947 rw_exit(&os_lock);
948 DNODE_STAT_BUMP(dnode_move_recheck2);
949 return (KMEM_CBRC_DONT_KNOW);
950 }
951
952 /*
953 * At this point we know that as long as we hold os->os_lock, the dnode
954 * cannot be freed and fields within the dnode can be safely accessed.
955 * The objset listing this dnode cannot go away as long as this dnode is
956 * on its list.
957 */
958 rw_exit(&os_lock);
959 if (DMU_OBJECT_IS_SPECIAL(odn->dn_object)) {
960 mutex_exit(&os->os_lock);
961 DNODE_STAT_BUMP(dnode_move_special);
962 return (KMEM_CBRC_NO);
963 }
964 ASSERT(odn->dn_dbuf != NULL); /* only "special" dnodes have no parent */
965
966 /*
967 * Lock the dnode handle to prevent the dnode from obtaining any new
968 * holds. This also prevents the descendant dbufs and the bonus dbuf
969 * from accessing the dnode, so that we can discount their holds. The
970 * handle is safe to access because we know that while the dnode cannot
971 * go away, neither can its handle. Once we hold dnh_zrlock, we can
972 * safely move any dnode referenced only by dbufs.
973 */
974 if (!zrl_tryenter(&odn->dn_handle->dnh_zrlock)) {
975 mutex_exit(&os->os_lock);
976 DNODE_STAT_BUMP(dnode_move_handle);
977 return (KMEM_CBRC_LATER);
978 }
979
980 /*
981 * Ensure a consistent view of the dnode's holds and the dnode's dbufs.
982 * We need to guarantee that there is a hold for every dbuf in order to
983 * determine whether the dnode is actively referenced. Falsely matching
984 * a dbuf to an active hold would lead to an unsafe move. It's possible
985 * that a thread already having an active dnode hold is about to add a
986 * dbuf, and we can't compare hold and dbuf counts while the add is in
987 * progress.
988 */
989 if (!rw_tryenter(&odn->dn_struct_rwlock, RW_WRITER)) {
990 zrl_exit(&odn->dn_handle->dnh_zrlock);
991 mutex_exit(&os->os_lock);
992 DNODE_STAT_BUMP(dnode_move_rwlock);
993 return (KMEM_CBRC_LATER);
994 }
995
996 /*
997 * A dbuf may be removed (evicted) without an active dnode hold. In that
998 * case, the dbuf count is decremented under the handle lock before the
999 * dbuf's hold is released. This order ensures that if we count the hold
1000 * after the dbuf is removed but before its hold is released, we will
1001 * treat the unmatched hold as active and exit safely. If we count the
1002 * hold before the dbuf is removed, the hold is discounted, and the
1003 * removal is blocked until the move completes.
1004 */
1005 refcount = zfs_refcount_count(&odn->dn_holds);
1006 ASSERT(refcount >= 0);
1007 dbufs = odn->dn_dbufs_count;
1008
1009 /* We can't have more dbufs than dnode holds. */
1010 ASSERT3U(dbufs, <=, refcount);
1011 DTRACE_PROBE3(dnode__move, dnode_t *, odn, int64_t, refcount,
1012 uint32_t, dbufs);
1013
1014 if (refcount > dbufs) {
1015 rw_exit(&odn->dn_struct_rwlock);
1016 zrl_exit(&odn->dn_handle->dnh_zrlock);
1017 mutex_exit(&os->os_lock);
1018 DNODE_STAT_BUMP(dnode_move_active);
1019 return (KMEM_CBRC_LATER);
1020 }
1021
1022 rw_exit(&odn->dn_struct_rwlock);
1023
1024 /*
1025 * At this point we know that anyone with a hold on the dnode is not
1026 * actively referencing it. The dnode is known and in a valid state to
1027 * move. We're holding the locks needed to execute the critical section.
1028 */
1029 dnode_move_impl(odn, ndn);
1030
1031 list_link_replace(&odn->dn_link, &ndn->dn_link);
1032 /* If the dnode was safe to move, the refcount cannot have changed. */
1033 ASSERT(refcount == zfs_refcount_count(&ndn->dn_holds));
1034 ASSERT(dbufs == ndn->dn_dbufs_count);
1035 zrl_exit(&ndn->dn_handle->dnh_zrlock); /* handle has moved */
1036 mutex_exit(&os->os_lock);
1037
1038 return (KMEM_CBRC_YES);
1039 }
1040 #endif /* _KERNEL */
1041
1042 static void
1043 dnode_slots_hold(dnode_children_t *children, int idx, int slots)
1044 {
1045 ASSERT3S(idx + slots, <=, DNODES_PER_BLOCK);
1046
1047 for (int i = idx; i < idx + slots; i++) {
1048 dnode_handle_t *dnh = &children->dnc_children[i];
1049 zrl_add(&dnh->dnh_zrlock);
1050 }
1051 }
1052
1053 static void
1054 dnode_slots_rele(dnode_children_t *children, int idx, int slots)
1055 {
1056 ASSERT3S(idx + slots, <=, DNODES_PER_BLOCK);
1057
1058 for (int i = idx; i < idx + slots; i++) {
1059 dnode_handle_t *dnh = &children->dnc_children[i];
1060
1061 if (zrl_is_locked(&dnh->dnh_zrlock))
1062 zrl_exit(&dnh->dnh_zrlock);
1063 else
1064 zrl_remove(&dnh->dnh_zrlock);
1065 }
1066 }
1067
1068 static int
1069 dnode_slots_tryenter(dnode_children_t *children, int idx, int slots)
1070 {
1071 ASSERT3S(idx + slots, <=, DNODES_PER_BLOCK);
1072
1073 for (int i = idx; i < idx + slots; i++) {
1074 dnode_handle_t *dnh = &children->dnc_children[i];
1075
1076 if (!zrl_tryenter(&dnh->dnh_zrlock)) {
1077 for (int j = idx; j < i; j++) {
1078 dnh = &children->dnc_children[j];
1079 zrl_exit(&dnh->dnh_zrlock);
1080 }
1081
1082 return (0);
1083 }
1084 }
1085
1086 return (1);
1087 }
1088
1089 static void
1090 dnode_set_slots(dnode_children_t *children, int idx, int slots, void *ptr)
1091 {
1092 ASSERT3S(idx + slots, <=, DNODES_PER_BLOCK);
1093
1094 for (int i = idx; i < idx + slots; i++) {
1095 dnode_handle_t *dnh = &children->dnc_children[i];
1096 dnh->dnh_dnode = ptr;
1097 }
1098 }
1099
1100 static boolean_t
1101 dnode_check_slots_free(dnode_children_t *children, int idx, int slots)
1102 {
1103 ASSERT3S(idx + slots, <=, DNODES_PER_BLOCK);
1104
1105 /*
1106 * If all dnode slots are either already free or
1107 * evictable return B_TRUE.
1108 */
1109 for (int i = idx; i < idx + slots; i++) {
1110 dnode_handle_t *dnh = &children->dnc_children[i];
1111 dnode_t *dn = dnh->dnh_dnode;
1112
1113 if (dn == DN_SLOT_FREE) {
1114 continue;
1115 } else if (DN_SLOT_IS_PTR(dn)) {
1116 mutex_enter(&dn->dn_mtx);
1117 boolean_t can_free = (dn->dn_type == DMU_OT_NONE &&
1118 zfs_refcount_is_zero(&dn->dn_holds) &&
1119 !DNODE_IS_DIRTY(dn));
1120 mutex_exit(&dn->dn_mtx);
1121
1122 if (!can_free)
1123 return (B_FALSE);
1124 else
1125 continue;
1126 } else {
1127 return (B_FALSE);
1128 }
1129 }
1130
1131 return (B_TRUE);
1132 }
1133
1134 static void
1135 dnode_reclaim_slots(dnode_children_t *children, int idx, int slots)
1136 {
1137 ASSERT3S(idx + slots, <=, DNODES_PER_BLOCK);
1138
1139 for (int i = idx; i < idx + slots; i++) {
1140 dnode_handle_t *dnh = &children->dnc_children[i];
1141
1142 ASSERT(zrl_is_locked(&dnh->dnh_zrlock));
1143
1144 if (DN_SLOT_IS_PTR(dnh->dnh_dnode)) {
1145 ASSERT3S(dnh->dnh_dnode->dn_type, ==, DMU_OT_NONE);
1146 dnode_destroy(dnh->dnh_dnode);
1147 dnh->dnh_dnode = DN_SLOT_FREE;
1148 }
1149 }
1150 }
1151
1152 void
1153 dnode_free_interior_slots(dnode_t *dn)
1154 {
1155 dnode_children_t *children = dmu_buf_get_user(&dn->dn_dbuf->db);
1156 int epb = dn->dn_dbuf->db.db_size >> DNODE_SHIFT;
1157 int idx = (dn->dn_object & (epb - 1)) + 1;
1158 int slots = dn->dn_num_slots - 1;
1159
1160 if (slots == 0)
1161 return;
1162
1163 ASSERT3S(idx + slots, <=, DNODES_PER_BLOCK);
1164
1165 while (!dnode_slots_tryenter(children, idx, slots))
1166 DNODE_STAT_BUMP(dnode_free_interior_lock_retry);
1167
1168 dnode_set_slots(children, idx, slots, DN_SLOT_FREE);
1169 dnode_slots_rele(children, idx, slots);
1170 }
1171
1172 void
1173 dnode_special_close(dnode_handle_t *dnh)
1174 {
1175 dnode_t *dn = dnh->dnh_dnode;
1176
1177 /*
1178 * Wait for final references to the dnode to clear. This can
1179 * only happen if the arc is asynchronously evicting state that
1180 * has a hold on this dnode while we are trying to evict this
1181 * dnode.
1182 */
1183 while (zfs_refcount_count(&dn->dn_holds) > 0)
1184 delay(1);
1185 ASSERT(dn->dn_dbuf == NULL ||
1186 dmu_buf_get_user(&dn->dn_dbuf->db) == NULL);
1187 zrl_add(&dnh->dnh_zrlock);
1188 dnode_destroy(dn); /* implicit zrl_remove() */
1189 zrl_destroy(&dnh->dnh_zrlock);
1190 dnh->dnh_dnode = NULL;
1191 }
1192
1193 void
1194 dnode_special_open(objset_t *os, dnode_phys_t *dnp, uint64_t object,
1195 dnode_handle_t *dnh)
1196 {
1197 dnode_t *dn;
1198
1199 zrl_init(&dnh->dnh_zrlock);
1200 zrl_tryenter(&dnh->dnh_zrlock);
1201
1202 dn = dnode_create(os, dnp, NULL, object, dnh);
1203 DNODE_VERIFY(dn);
1204
1205 zrl_exit(&dnh->dnh_zrlock);
1206 }
1207
1208 static void
1209 dnode_buf_evict_async(void *dbu)
1210 {
1211 dnode_children_t *dnc = dbu;
1212
1213 DNODE_STAT_BUMP(dnode_buf_evict);
1214
1215 for (int i = 0; i < dnc->dnc_count; i++) {
1216 dnode_handle_t *dnh = &dnc->dnc_children[i];
1217 dnode_t *dn;
1218
1219 /*
1220 * The dnode handle lock guards against the dnode moving to
1221 * another valid address, so there is no need here to guard
1222 * against changes to or from NULL.
1223 */
1224 if (!DN_SLOT_IS_PTR(dnh->dnh_dnode)) {
1225 zrl_destroy(&dnh->dnh_zrlock);
1226 dnh->dnh_dnode = DN_SLOT_UNINIT;
1227 continue;
1228 }
1229
1230 zrl_add(&dnh->dnh_zrlock);
1231 dn = dnh->dnh_dnode;
1232 /*
1233 * If there are holds on this dnode, then there should
1234 * be holds on the dnode's containing dbuf as well; thus
1235 * it wouldn't be eligible for eviction and this function
1236 * would not have been called.
1237 */
1238 ASSERT(zfs_refcount_is_zero(&dn->dn_holds));
1239 ASSERT(zfs_refcount_is_zero(&dn->dn_tx_holds));
1240
1241 dnode_destroy(dn); /* implicit zrl_remove() for first slot */
1242 zrl_destroy(&dnh->dnh_zrlock);
1243 dnh->dnh_dnode = DN_SLOT_UNINIT;
1244 }
1245 kmem_free(dnc, sizeof (dnode_children_t) +
1246 dnc->dnc_count * sizeof (dnode_handle_t));
1247 }
1248
1249 /*
1250 * When the DNODE_MUST_BE_FREE flag is set, the "slots" parameter is used
1251 * to ensure the hole at the specified object offset is large enough to
1252 * hold the dnode being created. The slots parameter is also used to ensure
1253 * a dnode does not span multiple dnode blocks. In both of these cases, if
1254 * a failure occurs, ENOSPC is returned. Keep in mind, these failure cases
1255 * are only possible when using DNODE_MUST_BE_FREE.
1256 *
1257 * If the DNODE_MUST_BE_ALLOCATED flag is set, "slots" must be 0.
1258 * dnode_hold_impl() will check if the requested dnode is already consumed
1259 * as an extra dnode slot by an large dnode, in which case it returns
1260 * ENOENT.
1261 *
1262 * If the DNODE_DRY_RUN flag is set, we don't actually hold the dnode, just
1263 * return whether the hold would succeed or not. tag and dnp should set to
1264 * NULL in this case.
1265 *
1266 * errors:
1267 * EINVAL - invalid object number or flags.
1268 * ENOSPC - hole too small to fulfill "slots" request (DNODE_MUST_BE_FREE)
1269 * EEXIST - Refers to an allocated dnode (DNODE_MUST_BE_FREE)
1270 * - Refers to a freeing dnode (DNODE_MUST_BE_FREE)
1271 * - Refers to an interior dnode slot (DNODE_MUST_BE_ALLOCATED)
1272 * ENOENT - The requested dnode is not allocated (DNODE_MUST_BE_ALLOCATED)
1273 * - The requested dnode is being freed (DNODE_MUST_BE_ALLOCATED)
1274 * EIO - i/o error error when reading the meta dnode dbuf.
1275 * succeeds even for free dnodes.
1276 */
1277 int
1278 dnode_hold_impl(objset_t *os, uint64_t object, int flag, int slots,
1279 void *tag, dnode_t **dnp)
1280 {
1281 int epb, idx, err;
1282 int drop_struct_lock = FALSE;
1283 int type;
1284 uint64_t blk;
1285 dnode_t *mdn, *dn;
1286 dmu_buf_impl_t *db;
1287 dnode_children_t *dnc;
1288 dnode_phys_t *dn_block;
1289 dnode_handle_t *dnh;
1290
1291 ASSERT(!(flag & DNODE_MUST_BE_ALLOCATED) || (slots == 0));
1292 ASSERT(!(flag & DNODE_MUST_BE_FREE) || (slots > 0));
1293 IMPLY(flag & DNODE_DRY_RUN, (tag == NULL) && (dnp == NULL));
1294
1295 /*
1296 * If you are holding the spa config lock as writer, you shouldn't
1297 * be asking the DMU to do *anything* unless it's the root pool
1298 * which may require us to read from the root filesystem while
1299 * holding some (not all) of the locks as writer.
1300 */
1301 ASSERT(spa_config_held(os->os_spa, SCL_ALL, RW_WRITER) == 0 ||
1302 (spa_is_root(os->os_spa) &&
1303 spa_config_held(os->os_spa, SCL_STATE, RW_WRITER)));
1304
1305 ASSERT((flag & DNODE_MUST_BE_ALLOCATED) || (flag & DNODE_MUST_BE_FREE));
1306
1307 if (object == DMU_USERUSED_OBJECT || object == DMU_GROUPUSED_OBJECT ||
1308 object == DMU_PROJECTUSED_OBJECT) {
1309 if (object == DMU_USERUSED_OBJECT)
1310 dn = DMU_USERUSED_DNODE(os);
1311 else if (object == DMU_GROUPUSED_OBJECT)
1312 dn = DMU_GROUPUSED_DNODE(os);
1313 else
1314 dn = DMU_PROJECTUSED_DNODE(os);
1315 if (dn == NULL)
1316 return (SET_ERROR(ENOENT));
1317 type = dn->dn_type;
1318 if ((flag & DNODE_MUST_BE_ALLOCATED) && type == DMU_OT_NONE)
1319 return (SET_ERROR(ENOENT));
1320 if ((flag & DNODE_MUST_BE_FREE) && type != DMU_OT_NONE)
1321 return (SET_ERROR(EEXIST));
1322 DNODE_VERIFY(dn);
1323 /* Don't actually hold if dry run, just return 0 */
1324 if (!(flag & DNODE_DRY_RUN)) {
1325 (void) zfs_refcount_add(&dn->dn_holds, tag);
1326 *dnp = dn;
1327 }
1328 return (0);
1329 }
1330
1331 if (object == 0 || object >= DN_MAX_OBJECT)
1332 return (SET_ERROR(EINVAL));
1333
1334 mdn = DMU_META_DNODE(os);
1335 ASSERT(mdn->dn_object == DMU_META_DNODE_OBJECT);
1336
1337 DNODE_VERIFY(mdn);
1338
1339 if (!RW_WRITE_HELD(&mdn->dn_struct_rwlock)) {
1340 rw_enter(&mdn->dn_struct_rwlock, RW_READER);
1341 drop_struct_lock = TRUE;
1342 }
1343
1344 blk = dbuf_whichblock(mdn, 0, object * sizeof (dnode_phys_t));
1345
1346 db = dbuf_hold(mdn, blk, FTAG);
1347 if (drop_struct_lock)
1348 rw_exit(&mdn->dn_struct_rwlock);
1349 if (db == NULL) {
1350 DNODE_STAT_BUMP(dnode_hold_dbuf_hold);
1351 return (SET_ERROR(EIO));
1352 }
1353 /*
1354 * We do not need to decrypt to read the dnode so it doesn't matter
1355 * if we get the encrypted or decrypted version.
1356 */
1357 err = dbuf_read(db, NULL, DB_RF_CANFAIL | DB_RF_NO_DECRYPT);
1358 if (err) {
1359 DNODE_STAT_BUMP(dnode_hold_dbuf_read);
1360 dbuf_rele(db, FTAG);
1361 return (err);
1362 }
1363
1364 ASSERT3U(db->db.db_size, >=, 1<<DNODE_SHIFT);
1365 epb = db->db.db_size >> DNODE_SHIFT;
1366
1367 idx = object & (epb - 1);
1368 dn_block = (dnode_phys_t *)db->db.db_data;
1369
1370 ASSERT(DB_DNODE(db)->dn_type == DMU_OT_DNODE);
1371 dnc = dmu_buf_get_user(&db->db);
1372 dnh = NULL;
1373 if (dnc == NULL) {
1374 dnode_children_t *winner;
1375 int skip = 0;
1376
1377 dnc = kmem_zalloc(sizeof (dnode_children_t) +
1378 epb * sizeof (dnode_handle_t), KM_SLEEP);
1379 dnc->dnc_count = epb;
1380 dnh = &dnc->dnc_children[0];
1381
1382 /* Initialize dnode slot status from dnode_phys_t */
1383 for (int i = 0; i < epb; i++) {
1384 zrl_init(&dnh[i].dnh_zrlock);
1385
1386 if (skip) {
1387 skip--;
1388 continue;
1389 }
1390
1391 if (dn_block[i].dn_type != DMU_OT_NONE) {
1392 int interior = dn_block[i].dn_extra_slots;
1393
1394 dnode_set_slots(dnc, i, 1, DN_SLOT_ALLOCATED);
1395 dnode_set_slots(dnc, i + 1, interior,
1396 DN_SLOT_INTERIOR);
1397 skip = interior;
1398 } else {
1399 dnh[i].dnh_dnode = DN_SLOT_FREE;
1400 skip = 0;
1401 }
1402 }
1403
1404 dmu_buf_init_user(&dnc->dnc_dbu, NULL,
1405 dnode_buf_evict_async, NULL);
1406 winner = dmu_buf_set_user(&db->db, &dnc->dnc_dbu);
1407 if (winner != NULL) {
1408
1409 for (int i = 0; i < epb; i++)
1410 zrl_destroy(&dnh[i].dnh_zrlock);
1411
1412 kmem_free(dnc, sizeof (dnode_children_t) +
1413 epb * sizeof (dnode_handle_t));
1414 dnc = winner;
1415 }
1416 }
1417
1418 ASSERT(dnc->dnc_count == epb);
1419 dn = DN_SLOT_UNINIT;
1420
1421 if (flag & DNODE_MUST_BE_ALLOCATED) {
1422 slots = 1;
1423
1424 while (dn == DN_SLOT_UNINIT) {
1425 dnode_slots_hold(dnc, idx, slots);
1426 dnh = &dnc->dnc_children[idx];
1427
1428 if (DN_SLOT_IS_PTR(dnh->dnh_dnode)) {
1429 dn = dnh->dnh_dnode;
1430 break;
1431 } else if (dnh->dnh_dnode == DN_SLOT_INTERIOR) {
1432 DNODE_STAT_BUMP(dnode_hold_alloc_interior);
1433 dnode_slots_rele(dnc, idx, slots);
1434 dbuf_rele(db, FTAG);
1435 return (SET_ERROR(EEXIST));
1436 } else if (dnh->dnh_dnode != DN_SLOT_ALLOCATED) {
1437 DNODE_STAT_BUMP(dnode_hold_alloc_misses);
1438 dnode_slots_rele(dnc, idx, slots);
1439 dbuf_rele(db, FTAG);
1440 return (SET_ERROR(ENOENT));
1441 }
1442
1443 dnode_slots_rele(dnc, idx, slots);
1444 if (!dnode_slots_tryenter(dnc, idx, slots)) {
1445 DNODE_STAT_BUMP(dnode_hold_alloc_lock_retry);
1446 continue;
1447 }
1448
1449 /*
1450 * Someone else won the race and called dnode_create()
1451 * after we checked DN_SLOT_IS_PTR() above but before
1452 * we acquired the lock.
1453 */
1454 if (DN_SLOT_IS_PTR(dnh->dnh_dnode)) {
1455 DNODE_STAT_BUMP(dnode_hold_alloc_lock_misses);
1456 dn = dnh->dnh_dnode;
1457 } else {
1458 dn = dnode_create(os, dn_block + idx, db,
1459 object, dnh);
1460 }
1461 }
1462
1463 mutex_enter(&dn->dn_mtx);
1464 if (dn->dn_type == DMU_OT_NONE || dn->dn_free_txg != 0) {
1465 DNODE_STAT_BUMP(dnode_hold_alloc_type_none);
1466 mutex_exit(&dn->dn_mtx);
1467 dnode_slots_rele(dnc, idx, slots);
1468 dbuf_rele(db, FTAG);
1469 return (SET_ERROR(ENOENT));
1470 }
1471
1472 /* Don't actually hold if dry run, just return 0 */
1473 if (flag & DNODE_DRY_RUN) {
1474 mutex_exit(&dn->dn_mtx);
1475 dnode_slots_rele(dnc, idx, slots);
1476 dbuf_rele(db, FTAG);
1477 return (0);
1478 }
1479
1480 DNODE_STAT_BUMP(dnode_hold_alloc_hits);
1481 } else if (flag & DNODE_MUST_BE_FREE) {
1482
1483 if (idx + slots - 1 >= DNODES_PER_BLOCK) {
1484 DNODE_STAT_BUMP(dnode_hold_free_overflow);
1485 dbuf_rele(db, FTAG);
1486 return (SET_ERROR(ENOSPC));
1487 }
1488
1489 while (dn == DN_SLOT_UNINIT) {
1490 dnode_slots_hold(dnc, idx, slots);
1491
1492 if (!dnode_check_slots_free(dnc, idx, slots)) {
1493 DNODE_STAT_BUMP(dnode_hold_free_misses);
1494 dnode_slots_rele(dnc, idx, slots);
1495 dbuf_rele(db, FTAG);
1496 return (SET_ERROR(ENOSPC));
1497 }
1498
1499 dnode_slots_rele(dnc, idx, slots);
1500 if (!dnode_slots_tryenter(dnc, idx, slots)) {
1501 DNODE_STAT_BUMP(dnode_hold_free_lock_retry);
1502 continue;
1503 }
1504
1505 if (!dnode_check_slots_free(dnc, idx, slots)) {
1506 DNODE_STAT_BUMP(dnode_hold_free_lock_misses);
1507 dnode_slots_rele(dnc, idx, slots);
1508 dbuf_rele(db, FTAG);
1509 return (SET_ERROR(ENOSPC));
1510 }
1511
1512 /*
1513 * Allocated but otherwise free dnodes which would
1514 * be in the interior of a multi-slot dnodes need
1515 * to be freed. Single slot dnodes can be safely
1516 * re-purposed as a performance optimization.
1517 */
1518 if (slots > 1)
1519 dnode_reclaim_slots(dnc, idx + 1, slots - 1);
1520
1521 dnh = &dnc->dnc_children[idx];
1522 if (DN_SLOT_IS_PTR(dnh->dnh_dnode)) {
1523 dn = dnh->dnh_dnode;
1524 } else {
1525 dn = dnode_create(os, dn_block + idx, db,
1526 object, dnh);
1527 }
1528 }
1529
1530 mutex_enter(&dn->dn_mtx);
1531 if (!zfs_refcount_is_zero(&dn->dn_holds) || dn->dn_free_txg) {
1532 DNODE_STAT_BUMP(dnode_hold_free_refcount);
1533 mutex_exit(&dn->dn_mtx);
1534 dnode_slots_rele(dnc, idx, slots);
1535 dbuf_rele(db, FTAG);
1536 return (SET_ERROR(EEXIST));
1537 }
1538
1539 /* Don't actually hold if dry run, just return 0 */
1540 if (flag & DNODE_DRY_RUN) {
1541 mutex_exit(&dn->dn_mtx);
1542 dnode_slots_rele(dnc, idx, slots);
1543 dbuf_rele(db, FTAG);
1544 return (0);
1545 }
1546
1547 dnode_set_slots(dnc, idx + 1, slots - 1, DN_SLOT_INTERIOR);
1548 DNODE_STAT_BUMP(dnode_hold_free_hits);
1549 } else {
1550 dbuf_rele(db, FTAG);
1551 return (SET_ERROR(EINVAL));
1552 }
1553
1554 ASSERT0(dn->dn_free_txg);
1555
1556 if (zfs_refcount_add(&dn->dn_holds, tag) == 1)
1557 dbuf_add_ref(db, dnh);
1558
1559 mutex_exit(&dn->dn_mtx);
1560
1561 /* Now we can rely on the hold to prevent the dnode from moving. */
1562 dnode_slots_rele(dnc, idx, slots);
1563
1564 DNODE_VERIFY(dn);
1565 ASSERT3P(dn->dn_dbuf, ==, db);
1566 ASSERT3U(dn->dn_object, ==, object);
1567 dbuf_rele(db, FTAG);
1568
1569 *dnp = dn;
1570 return (0);
1571 }
1572
1573 /*
1574 * Return held dnode if the object is allocated, NULL if not.
1575 */
1576 int
1577 dnode_hold(objset_t *os, uint64_t object, void *tag, dnode_t **dnp)
1578 {
1579 return (dnode_hold_impl(os, object, DNODE_MUST_BE_ALLOCATED, 0, tag,
1580 dnp));
1581 }
1582
1583 /*
1584 * Can only add a reference if there is already at least one
1585 * reference on the dnode. Returns FALSE if unable to add a
1586 * new reference.
1587 */
1588 boolean_t
1589 dnode_add_ref(dnode_t *dn, void *tag)
1590 {
1591 mutex_enter(&dn->dn_mtx);
1592 if (zfs_refcount_is_zero(&dn->dn_holds)) {
1593 mutex_exit(&dn->dn_mtx);
1594 return (FALSE);
1595 }
1596 VERIFY(1 < zfs_refcount_add(&dn->dn_holds, tag));
1597 mutex_exit(&dn->dn_mtx);
1598 return (TRUE);
1599 }
1600
1601 void
1602 dnode_rele(dnode_t *dn, void *tag)
1603 {
1604 mutex_enter(&dn->dn_mtx);
1605 dnode_rele_and_unlock(dn, tag, B_FALSE);
1606 }
1607
1608 void
1609 dnode_rele_and_unlock(dnode_t *dn, void *tag, boolean_t evicting)
1610 {
1611 uint64_t refs;
1612 /* Get while the hold prevents the dnode from moving. */
1613 dmu_buf_impl_t *db = dn->dn_dbuf;
1614 dnode_handle_t *dnh = dn->dn_handle;
1615
1616 refs = zfs_refcount_remove(&dn->dn_holds, tag);
1617 mutex_exit(&dn->dn_mtx);
1618
1619 /*
1620 * It's unsafe to release the last hold on a dnode by dnode_rele() or
1621 * indirectly by dbuf_rele() while relying on the dnode handle to
1622 * prevent the dnode from moving, since releasing the last hold could
1623 * result in the dnode's parent dbuf evicting its dnode handles. For
1624 * that reason anyone calling dnode_rele() or dbuf_rele() without some
1625 * other direct or indirect hold on the dnode must first drop the dnode
1626 * handle.
1627 */
1628 ASSERT(refs > 0 || dnh->dnh_zrlock.zr_owner != curthread);
1629
1630 /* NOTE: the DNODE_DNODE does not have a dn_dbuf */
1631 if (refs == 0 && db != NULL) {
1632 /*
1633 * Another thread could add a hold to the dnode handle in
1634 * dnode_hold_impl() while holding the parent dbuf. Since the
1635 * hold on the parent dbuf prevents the handle from being
1636 * destroyed, the hold on the handle is OK. We can't yet assert
1637 * that the handle has zero references, but that will be
1638 * asserted anyway when the handle gets destroyed.
1639 */
1640 mutex_enter(&db->db_mtx);
1641 dbuf_rele_and_unlock(db, dnh, evicting);
1642 }
1643 }
1644
1645 /*
1646 * Test whether we can create a dnode at the specified location.
1647 */
1648 int
1649 dnode_try_claim(objset_t *os, uint64_t object, int slots)
1650 {
1651 return (dnode_hold_impl(os, object, DNODE_MUST_BE_FREE | DNODE_DRY_RUN,
1652 slots, NULL, NULL));
1653 }
1654
1655 void
1656 dnode_setdirty(dnode_t *dn, dmu_tx_t *tx)
1657 {
1658 objset_t *os = dn->dn_objset;
1659 uint64_t txg = tx->tx_txg;
1660
1661 if (DMU_OBJECT_IS_SPECIAL(dn->dn_object)) {
1662 dsl_dataset_dirty(os->os_dsl_dataset, tx);
1663 return;
1664 }
1665
1666 DNODE_VERIFY(dn);
1667
1668 #ifdef ZFS_DEBUG
1669 mutex_enter(&dn->dn_mtx);
1670 ASSERT(dn->dn_phys->dn_type || dn->dn_allocated_txg);
1671 ASSERT(dn->dn_free_txg == 0 || dn->dn_free_txg >= txg);
1672 mutex_exit(&dn->dn_mtx);
1673 #endif
1674
1675 /*
1676 * Determine old uid/gid when necessary
1677 */
1678 dmu_objset_userquota_get_ids(dn, B_TRUE, tx);
1679
1680 multilist_t *dirtylist = os->os_dirty_dnodes[txg & TXG_MASK];
1681 multilist_sublist_t *mls = multilist_sublist_lock_obj(dirtylist, dn);
1682
1683 /*
1684 * If we are already marked dirty, we're done.
1685 */
1686 if (multilist_link_active(&dn->dn_dirty_link[txg & TXG_MASK])) {
1687 multilist_sublist_unlock(mls);
1688 return;
1689 }
1690
1691 ASSERT(!zfs_refcount_is_zero(&dn->dn_holds) ||
1692 !avl_is_empty(&dn->dn_dbufs));
1693 ASSERT(dn->dn_datablksz != 0);
1694 ASSERT0(dn->dn_next_bonuslen[txg&TXG_MASK]);
1695 ASSERT0(dn->dn_next_blksz[txg&TXG_MASK]);
1696 ASSERT0(dn->dn_next_bonustype[txg&TXG_MASK]);
1697
1698 dprintf_ds(os->os_dsl_dataset, "obj=%llu txg=%llu\n",
1699 dn->dn_object, txg);
1700
1701 multilist_sublist_insert_head(mls, dn);
1702
1703 multilist_sublist_unlock(mls);
1704
1705 /*
1706 * The dnode maintains a hold on its containing dbuf as
1707 * long as there are holds on it. Each instantiated child
1708 * dbuf maintains a hold on the dnode. When the last child
1709 * drops its hold, the dnode will drop its hold on the
1710 * containing dbuf. We add a "dirty hold" here so that the
1711 * dnode will hang around after we finish processing its
1712 * children.
1713 */
1714 VERIFY(dnode_add_ref(dn, (void *)(uintptr_t)tx->tx_txg));
1715
1716 (void) dbuf_dirty(dn->dn_dbuf, tx);
1717
1718 dsl_dataset_dirty(os->os_dsl_dataset, tx);
1719 }
1720
1721 void
1722 dnode_free(dnode_t *dn, dmu_tx_t *tx)
1723 {
1724 mutex_enter(&dn->dn_mtx);
1725 if (dn->dn_type == DMU_OT_NONE || dn->dn_free_txg) {
1726 mutex_exit(&dn->dn_mtx);
1727 return;
1728 }
1729 dn->dn_free_txg = tx->tx_txg;
1730 mutex_exit(&dn->dn_mtx);
1731
1732 dnode_setdirty(dn, tx);
1733 }
1734
1735 /*
1736 * Try to change the block size for the indicated dnode. This can only
1737 * succeed if there are no blocks allocated or dirty beyond first block
1738 */
1739 int
1740 dnode_set_blksz(dnode_t *dn, uint64_t size, int ibs, dmu_tx_t *tx)
1741 {
1742 dmu_buf_impl_t *db;
1743 int err;
1744
1745 ASSERT3U(size, <=, spa_maxblocksize(dmu_objset_spa(dn->dn_objset)));
1746 if (size == 0)
1747 size = SPA_MINBLOCKSIZE;
1748 else
1749 size = P2ROUNDUP(size, SPA_MINBLOCKSIZE);
1750
1751 if (ibs == dn->dn_indblkshift)
1752 ibs = 0;
1753
1754 if (size >> SPA_MINBLOCKSHIFT == dn->dn_datablkszsec && ibs == 0)
1755 return (0);
1756
1757 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
1758
1759 /* Check for any allocated blocks beyond the first */
1760 if (dn->dn_maxblkid != 0)
1761 goto fail;
1762
1763 mutex_enter(&dn->dn_dbufs_mtx);
1764 for (db = avl_first(&dn->dn_dbufs); db != NULL;
1765 db = AVL_NEXT(&dn->dn_dbufs, db)) {
1766 if (db->db_blkid != 0 && db->db_blkid != DMU_BONUS_BLKID &&
1767 db->db_blkid != DMU_SPILL_BLKID) {
1768 mutex_exit(&dn->dn_dbufs_mtx);
1769 goto fail;
1770 }
1771 }
1772 mutex_exit(&dn->dn_dbufs_mtx);
1773
1774 if (ibs && dn->dn_nlevels != 1)
1775 goto fail;
1776
1777 /* resize the old block */
1778 err = dbuf_hold_impl(dn, 0, 0, TRUE, FALSE, FTAG, &db);
1779 if (err == 0)
1780 dbuf_new_size(db, size, tx);
1781 else if (err != ENOENT)
1782 goto fail;
1783
1784 dnode_setdblksz(dn, size);
1785 dnode_setdirty(dn, tx);
1786 dn->dn_next_blksz[tx->tx_txg&TXG_MASK] = size;
1787 if (ibs) {
1788 dn->dn_indblkshift = ibs;
1789 dn->dn_next_indblkshift[tx->tx_txg&TXG_MASK] = ibs;
1790 }
1791 /* rele after we have fixed the blocksize in the dnode */
1792 if (db)
1793 dbuf_rele(db, FTAG);
1794
1795 rw_exit(&dn->dn_struct_rwlock);
1796 return (0);
1797
1798 fail:
1799 rw_exit(&dn->dn_struct_rwlock);
1800 return (SET_ERROR(ENOTSUP));
1801 }
1802
1803 static void
1804 dnode_set_nlevels_impl(dnode_t *dn, int new_nlevels, dmu_tx_t *tx)
1805 {
1806 uint64_t txgoff = tx->tx_txg & TXG_MASK;
1807 int old_nlevels = dn->dn_nlevels;
1808 dmu_buf_impl_t *db;
1809 list_t *list;
1810 dbuf_dirty_record_t *new, *dr, *dr_next;
1811
1812 ASSERT(RW_WRITE_HELD(&dn->dn_struct_rwlock));
1813
1814 dn->dn_nlevels = new_nlevels;
1815
1816 ASSERT3U(new_nlevels, >, dn->dn_next_nlevels[txgoff]);
1817 dn->dn_next_nlevels[txgoff] = new_nlevels;
1818
1819 /* dirty the left indirects */
1820 db = dbuf_hold_level(dn, old_nlevels, 0, FTAG);
1821 ASSERT(db != NULL);
1822 new = dbuf_dirty(db, tx);
1823 dbuf_rele(db, FTAG);
1824
1825 /* transfer the dirty records to the new indirect */
1826 mutex_enter(&dn->dn_mtx);
1827 mutex_enter(&new->dt.di.dr_mtx);
1828 list = &dn->dn_dirty_records[txgoff];
1829 for (dr = list_head(list); dr; dr = dr_next) {
1830 dr_next = list_next(&dn->dn_dirty_records[txgoff], dr);
1831 if (dr->dr_dbuf->db_level != new_nlevels-1 &&
1832 dr->dr_dbuf->db_blkid != DMU_BONUS_BLKID &&
1833 dr->dr_dbuf->db_blkid != DMU_SPILL_BLKID) {
1834 ASSERT(dr->dr_dbuf->db_level == old_nlevels-1);
1835 list_remove(&dn->dn_dirty_records[txgoff], dr);
1836 list_insert_tail(&new->dt.di.dr_children, dr);
1837 dr->dr_parent = new;
1838 }
1839 }
1840 mutex_exit(&new->dt.di.dr_mtx);
1841 mutex_exit(&dn->dn_mtx);
1842 }
1843
1844 int
1845 dnode_set_nlevels(dnode_t *dn, int nlevels, dmu_tx_t *tx)
1846 {
1847 int ret = 0;
1848
1849 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
1850
1851 if (dn->dn_nlevels == nlevels) {
1852 ret = 0;
1853 goto out;
1854 } else if (nlevels < dn->dn_nlevels) {
1855 ret = SET_ERROR(EINVAL);
1856 goto out;
1857 }
1858
1859 dnode_set_nlevels_impl(dn, nlevels, tx);
1860
1861 out:
1862 rw_exit(&dn->dn_struct_rwlock);
1863 return (ret);
1864 }
1865
1866 /* read-holding callers must not rely on the lock being continuously held */
1867 void
1868 dnode_new_blkid(dnode_t *dn, uint64_t blkid, dmu_tx_t *tx, boolean_t have_read,
1869 boolean_t force)
1870 {
1871 int epbs, new_nlevels;
1872 uint64_t sz;
1873
1874 ASSERT(blkid != DMU_BONUS_BLKID);
1875
1876 ASSERT(have_read ?
1877 RW_READ_HELD(&dn->dn_struct_rwlock) :
1878 RW_WRITE_HELD(&dn->dn_struct_rwlock));
1879
1880 /*
1881 * if we have a read-lock, check to see if we need to do any work
1882 * before upgrading to a write-lock.
1883 */
1884 if (have_read) {
1885 if (blkid <= dn->dn_maxblkid)
1886 return;
1887
1888 if (!rw_tryupgrade(&dn->dn_struct_rwlock)) {
1889 rw_exit(&dn->dn_struct_rwlock);
1890 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
1891 }
1892 }
1893
1894 /*
1895 * Raw sends (indicated by the force flag) require that we take the
1896 * given blkid even if the value is lower than the current value.
1897 */
1898 if (!force && blkid <= dn->dn_maxblkid)
1899 goto out;
1900
1901 /*
1902 * We use the (otherwise unused) top bit of dn_next_maxblkid[txgoff]
1903 * to indicate that this field is set. This allows us to set the
1904 * maxblkid to 0 on an existing object in dnode_sync().
1905 */
1906 dn->dn_maxblkid = blkid;
1907 dn->dn_next_maxblkid[tx->tx_txg & TXG_MASK] =
1908 blkid | DMU_NEXT_MAXBLKID_SET;
1909
1910 /*
1911 * Compute the number of levels necessary to support the new maxblkid.
1912 * Raw sends will ensure nlevels is set correctly for us.
1913 */
1914 new_nlevels = 1;
1915 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT;
1916 for (sz = dn->dn_nblkptr;
1917 sz <= blkid && sz >= dn->dn_nblkptr; sz <<= epbs)
1918 new_nlevels++;
1919
1920 if (!force) {
1921 if (new_nlevels > dn->dn_nlevels)
1922 dnode_set_nlevels_impl(dn, new_nlevels, tx);
1923 } else {
1924 ASSERT3U(dn->dn_nlevels, >=, new_nlevels);
1925 }
1926
1927 out:
1928 if (have_read)
1929 rw_downgrade(&dn->dn_struct_rwlock);
1930 }
1931
1932 static void
1933 dnode_dirty_l1(dnode_t *dn, uint64_t l1blkid, dmu_tx_t *tx)
1934 {
1935 dmu_buf_impl_t *db = dbuf_hold_level(dn, 1, l1blkid, FTAG);
1936 if (db != NULL) {
1937 dmu_buf_will_dirty(&db->db, tx);
1938 dbuf_rele(db, FTAG);
1939 }
1940 }
1941
1942 /*
1943 * Dirty all the in-core level-1 dbufs in the range specified by start_blkid
1944 * and end_blkid.
1945 */
1946 static void
1947 dnode_dirty_l1range(dnode_t *dn, uint64_t start_blkid, uint64_t end_blkid,
1948 dmu_tx_t *tx)
1949 {
1950 dmu_buf_impl_t db_search;
1951 dmu_buf_impl_t *db;
1952 avl_index_t where;
1953
1954 mutex_enter(&dn->dn_dbufs_mtx);
1955
1956 db_search.db_level = 1;
1957 db_search.db_blkid = start_blkid + 1;
1958 db_search.db_state = DB_SEARCH;
1959 for (;;) {
1960
1961 db = avl_find(&dn->dn_dbufs, &db_search, &where);
1962 if (db == NULL)
1963 db = avl_nearest(&dn->dn_dbufs, where, AVL_AFTER);
1964
1965 if (db == NULL || db->db_level != 1 ||
1966 db->db_blkid >= end_blkid) {
1967 break;
1968 }
1969
1970 /*
1971 * Setup the next blkid we want to search for.
1972 */
1973 db_search.db_blkid = db->db_blkid + 1;
1974 ASSERT3U(db->db_blkid, >=, start_blkid);
1975
1976 /*
1977 * If the dbuf transitions to DB_EVICTING while we're trying
1978 * to dirty it, then we will be unable to discover it in
1979 * the dbuf hash table. This will result in a call to
1980 * dbuf_create() which needs to acquire the dn_dbufs_mtx
1981 * lock. To avoid a deadlock, we drop the lock before
1982 * dirtying the level-1 dbuf.
1983 */
1984 mutex_exit(&dn->dn_dbufs_mtx);
1985 dnode_dirty_l1(dn, db->db_blkid, tx);
1986 mutex_enter(&dn->dn_dbufs_mtx);
1987 }
1988
1989 #ifdef ZFS_DEBUG
1990 /*
1991 * Walk all the in-core level-1 dbufs and verify they have been dirtied.
1992 */
1993 db_search.db_level = 1;
1994 db_search.db_blkid = start_blkid + 1;
1995 db_search.db_state = DB_SEARCH;
1996 db = avl_find(&dn->dn_dbufs, &db_search, &where);
1997 if (db == NULL)
1998 db = avl_nearest(&dn->dn_dbufs, where, AVL_AFTER);
1999 for (; db != NULL; db = AVL_NEXT(&dn->dn_dbufs, db)) {
2000 if (db->db_level != 1 || db->db_blkid >= end_blkid)
2001 break;
2002 ASSERT(db->db_dirtycnt > 0);
2003 }
2004 #endif
2005 mutex_exit(&dn->dn_dbufs_mtx);
2006 }
2007
2008 void
2009 dnode_free_range(dnode_t *dn, uint64_t off, uint64_t len, dmu_tx_t *tx)
2010 {
2011 dmu_buf_impl_t *db;
2012 uint64_t blkoff, blkid, nblks;
2013 int blksz, blkshift, head, tail;
2014 int trunc = FALSE;
2015 int epbs;
2016
2017 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
2018 blksz = dn->dn_datablksz;
2019 blkshift = dn->dn_datablkshift;
2020 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT;
2021
2022 if (len == DMU_OBJECT_END) {
2023 len = UINT64_MAX - off;
2024 trunc = TRUE;
2025 }
2026
2027 /*
2028 * First, block align the region to free:
2029 */
2030 if (ISP2(blksz)) {
2031 head = P2NPHASE(off, blksz);
2032 blkoff = P2PHASE(off, blksz);
2033 if ((off >> blkshift) > dn->dn_maxblkid)
2034 goto out;
2035 } else {
2036 ASSERT(dn->dn_maxblkid == 0);
2037 if (off == 0 && len >= blksz) {
2038 /*
2039 * Freeing the whole block; fast-track this request.
2040 */
2041 blkid = 0;
2042 nblks = 1;
2043 if (dn->dn_nlevels > 1)
2044 dnode_dirty_l1(dn, 0, tx);
2045 goto done;
2046 } else if (off >= blksz) {
2047 /* Freeing past end-of-data */
2048 goto out;
2049 } else {
2050 /* Freeing part of the block. */
2051 head = blksz - off;
2052 ASSERT3U(head, >, 0);
2053 }
2054 blkoff = off;
2055 }
2056 /* zero out any partial block data at the start of the range */
2057 if (head) {
2058 ASSERT3U(blkoff + head, ==, blksz);
2059 if (len < head)
2060 head = len;
2061 if (dbuf_hold_impl(dn, 0, dbuf_whichblock(dn, 0, off),
2062 TRUE, FALSE, FTAG, &db) == 0) {
2063 caddr_t data;
2064
2065 /* don't dirty if it isn't on disk and isn't dirty */
2066 if (db->db_last_dirty ||
2067 (db->db_blkptr && !BP_IS_HOLE(db->db_blkptr))) {
2068 rw_exit(&dn->dn_struct_rwlock);
2069 dmu_buf_will_dirty(&db->db, tx);
2070 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
2071 data = db->db.db_data;
2072 bzero(data + blkoff, head);
2073 }
2074 dbuf_rele(db, FTAG);
2075 }
2076 off += head;
2077 len -= head;
2078 }
2079
2080 /* If the range was less than one block, we're done */
2081 if (len == 0)
2082 goto out;
2083
2084 /* If the remaining range is past end of file, we're done */
2085 if ((off >> blkshift) > dn->dn_maxblkid)
2086 goto out;
2087
2088 ASSERT(ISP2(blksz));
2089 if (trunc)
2090 tail = 0;
2091 else
2092 tail = P2PHASE(len, blksz);
2093
2094 ASSERT0(P2PHASE(off, blksz));
2095 /* zero out any partial block data at the end of the range */
2096 if (tail) {
2097 if (len < tail)
2098 tail = len;
2099 if (dbuf_hold_impl(dn, 0, dbuf_whichblock(dn, 0, off+len),
2100 TRUE, FALSE, FTAG, &db) == 0) {
2101 /* don't dirty if not on disk and not dirty */
2102 if (db->db_last_dirty ||
2103 (db->db_blkptr && !BP_IS_HOLE(db->db_blkptr))) {
2104 rw_exit(&dn->dn_struct_rwlock);
2105 dmu_buf_will_dirty(&db->db, tx);
2106 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
2107 bzero(db->db.db_data, tail);
2108 }
2109 dbuf_rele(db, FTAG);
2110 }
2111 len -= tail;
2112 }
2113
2114 /* If the range did not include a full block, we are done */
2115 if (len == 0)
2116 goto out;
2117
2118 ASSERT(IS_P2ALIGNED(off, blksz));
2119 ASSERT(trunc || IS_P2ALIGNED(len, blksz));
2120 blkid = off >> blkshift;
2121 nblks = len >> blkshift;
2122 if (trunc)
2123 nblks += 1;
2124
2125 /*
2126 * Dirty all the indirect blocks in this range. Note that only
2127 * the first and last indirect blocks can actually be written
2128 * (if they were partially freed) -- they must be dirtied, even if
2129 * they do not exist on disk yet. The interior blocks will
2130 * be freed by free_children(), so they will not actually be written.
2131 * Even though these interior blocks will not be written, we
2132 * dirty them for two reasons:
2133 *
2134 * - It ensures that the indirect blocks remain in memory until
2135 * syncing context. (They have already been prefetched by
2136 * dmu_tx_hold_free(), so we don't have to worry about reading
2137 * them serially here.)
2138 *
2139 * - The dirty space accounting will put pressure on the txg sync
2140 * mechanism to begin syncing, and to delay transactions if there
2141 * is a large amount of freeing. Even though these indirect
2142 * blocks will not be written, we could need to write the same
2143 * amount of space if we copy the freed BPs into deadlists.
2144 */
2145 if (dn->dn_nlevels > 1) {
2146 uint64_t first, last;
2147
2148 first = blkid >> epbs;
2149 dnode_dirty_l1(dn, first, tx);
2150 if (trunc)
2151 last = dn->dn_maxblkid >> epbs;
2152 else
2153 last = (blkid + nblks - 1) >> epbs;
2154 if (last != first)
2155 dnode_dirty_l1(dn, last, tx);
2156
2157 dnode_dirty_l1range(dn, first, last, tx);
2158
2159 int shift = dn->dn_datablkshift + dn->dn_indblkshift -
2160 SPA_BLKPTRSHIFT;
2161 for (uint64_t i = first + 1; i < last; i++) {
2162 /*
2163 * Set i to the blockid of the next non-hole
2164 * level-1 indirect block at or after i. Note
2165 * that dnode_next_offset() operates in terms of
2166 * level-0-equivalent bytes.
2167 */
2168 uint64_t ibyte = i << shift;
2169 int err = dnode_next_offset(dn, DNODE_FIND_HAVELOCK,
2170 &ibyte, 2, 1, 0);
2171 i = ibyte >> shift;
2172 if (i >= last)
2173 break;
2174
2175 /*
2176 * Normally we should not see an error, either
2177 * from dnode_next_offset() or dbuf_hold_level()
2178 * (except for ESRCH from dnode_next_offset).
2179 * If there is an i/o error, then when we read
2180 * this block in syncing context, it will use
2181 * ZIO_FLAG_MUSTSUCCEED, and thus hang/panic according
2182 * to the "failmode" property. dnode_next_offset()
2183 * doesn't have a flag to indicate MUSTSUCCEED.
2184 */
2185 if (err != 0)
2186 break;
2187
2188 dnode_dirty_l1(dn, i, tx);
2189 }
2190 }
2191
2192 done:
2193 /*
2194 * Add this range to the dnode range list.
2195 * We will finish up this free operation in the syncing phase.
2196 */
2197 mutex_enter(&dn->dn_mtx);
2198 int txgoff = tx->tx_txg & TXG_MASK;
2199 if (dn->dn_free_ranges[txgoff] == NULL) {
2200 dn->dn_free_ranges[txgoff] = range_tree_create(NULL, NULL);
2201 }
2202 range_tree_clear(dn->dn_free_ranges[txgoff], blkid, nblks);
2203 range_tree_add(dn->dn_free_ranges[txgoff], blkid, nblks);
2204 dprintf_dnode(dn, "blkid=%llu nblks=%llu txg=%llu\n",
2205 blkid, nblks, tx->tx_txg);
2206 mutex_exit(&dn->dn_mtx);
2207
2208 dbuf_free_range(dn, blkid, blkid + nblks - 1, tx);
2209 dnode_setdirty(dn, tx);
2210 out:
2211
2212 rw_exit(&dn->dn_struct_rwlock);
2213 }
2214
2215 static boolean_t
2216 dnode_spill_freed(dnode_t *dn)
2217 {
2218 int i;
2219
2220 mutex_enter(&dn->dn_mtx);
2221 for (i = 0; i < TXG_SIZE; i++) {
2222 if (dn->dn_rm_spillblk[i] == DN_KILL_SPILLBLK)
2223 break;
2224 }
2225 mutex_exit(&dn->dn_mtx);
2226 return (i < TXG_SIZE);
2227 }
2228
2229 /* return TRUE if this blkid was freed in a recent txg, or FALSE if it wasn't */
2230 uint64_t
2231 dnode_block_freed(dnode_t *dn, uint64_t blkid)
2232 {
2233 void *dp = spa_get_dsl(dn->dn_objset->os_spa);
2234 int i;
2235
2236 if (blkid == DMU_BONUS_BLKID)
2237 return (FALSE);
2238
2239 /*
2240 * If we're in the process of opening the pool, dp will not be
2241 * set yet, but there shouldn't be anything dirty.
2242 */
2243 if (dp == NULL)
2244 return (FALSE);
2245
2246 if (dn->dn_free_txg)
2247 return (TRUE);
2248
2249 if (blkid == DMU_SPILL_BLKID)
2250 return (dnode_spill_freed(dn));
2251
2252 mutex_enter(&dn->dn_mtx);
2253 for (i = 0; i < TXG_SIZE; i++) {
2254 if (dn->dn_free_ranges[i] != NULL &&
2255 range_tree_contains(dn->dn_free_ranges[i], blkid, 1))
2256 break;
2257 }
2258 mutex_exit(&dn->dn_mtx);
2259 return (i < TXG_SIZE);
2260 }
2261
2262 /* call from syncing context when we actually write/free space for this dnode */
2263 void
2264 dnode_diduse_space(dnode_t *dn, int64_t delta)
2265 {
2266 uint64_t space;
2267 dprintf_dnode(dn, "dn=%p dnp=%p used=%llu delta=%lld\n",
2268 dn, dn->dn_phys,
2269 (u_longlong_t)dn->dn_phys->dn_used,
2270 (longlong_t)delta);
2271
2272 mutex_enter(&dn->dn_mtx);
2273 space = DN_USED_BYTES(dn->dn_phys);
2274 if (delta > 0) {
2275 ASSERT3U(space + delta, >=, space); /* no overflow */
2276 } else {
2277 ASSERT3U(space, >=, -delta); /* no underflow */
2278 }
2279 space += delta;
2280 if (spa_version(dn->dn_objset->os_spa) < SPA_VERSION_DNODE_BYTES) {
2281 ASSERT((dn->dn_phys->dn_flags & DNODE_FLAG_USED_BYTES) == 0);
2282 ASSERT0(P2PHASE(space, 1<<DEV_BSHIFT));
2283 dn->dn_phys->dn_used = space >> DEV_BSHIFT;
2284 } else {
2285 dn->dn_phys->dn_used = space;
2286 dn->dn_phys->dn_flags |= DNODE_FLAG_USED_BYTES;
2287 }
2288 mutex_exit(&dn->dn_mtx);
2289 }
2290
2291 /*
2292 * Scans a block at the indicated "level" looking for a hole or data,
2293 * depending on 'flags'.
2294 *
2295 * If level > 0, then we are scanning an indirect block looking at its
2296 * pointers. If level == 0, then we are looking at a block of dnodes.
2297 *
2298 * If we don't find what we are looking for in the block, we return ESRCH.
2299 * Otherwise, return with *offset pointing to the beginning (if searching
2300 * forwards) or end (if searching backwards) of the range covered by the
2301 * block pointer we matched on (or dnode).
2302 *
2303 * The basic search algorithm used below by dnode_next_offset() is to
2304 * use this function to search up the block tree (widen the search) until
2305 * we find something (i.e., we don't return ESRCH) and then search back
2306 * down the tree (narrow the search) until we reach our original search
2307 * level.
2308 */
2309 static int
2310 dnode_next_offset_level(dnode_t *dn, int flags, uint64_t *offset,
2311 int lvl, uint64_t blkfill, uint64_t txg)
2312 {
2313 dmu_buf_impl_t *db = NULL;
2314 void *data = NULL;
2315 uint64_t epbs = dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT;
2316 uint64_t epb = 1ULL << epbs;
2317 uint64_t minfill, maxfill;
2318 boolean_t hole;
2319 int i, inc, error, span;
2320
2321 dprintf("probing object %llu offset %llx level %d of %u\n",
2322 dn->dn_object, *offset, lvl, dn->dn_phys->dn_nlevels);
2323
2324 hole = ((flags & DNODE_FIND_HOLE) != 0);
2325 inc = (flags & DNODE_FIND_BACKWARDS) ? -1 : 1;
2326 ASSERT(txg == 0 || !hole);
2327
2328 if (lvl == dn->dn_phys->dn_nlevels) {
2329 error = 0;
2330 epb = dn->dn_phys->dn_nblkptr;
2331 data = dn->dn_phys->dn_blkptr;
2332 } else {
2333 uint64_t blkid = dbuf_whichblock(dn, lvl, *offset);
2334 error = dbuf_hold_impl(dn, lvl, blkid, TRUE, FALSE, FTAG, &db);
2335 if (error) {
2336 if (error != ENOENT)
2337 return (error);
2338 if (hole)
2339 return (0);
2340 /*
2341 * This can only happen when we are searching up
2342 * the block tree for data. We don't really need to
2343 * adjust the offset, as we will just end up looking
2344 * at the pointer to this block in its parent, and its
2345 * going to be unallocated, so we will skip over it.
2346 */
2347 return (SET_ERROR(ESRCH));
2348 }
2349 error = dbuf_read(db, NULL,
2350 DB_RF_CANFAIL | DB_RF_HAVESTRUCT | DB_RF_NO_DECRYPT);
2351 if (error) {
2352 dbuf_rele(db, FTAG);
2353 return (error);
2354 }
2355 data = db->db.db_data;
2356 }
2357
2358
2359 if (db != NULL && txg != 0 && (db->db_blkptr == NULL ||
2360 db->db_blkptr->blk_birth <= txg ||
2361 BP_IS_HOLE(db->db_blkptr))) {
2362 /*
2363 * This can only happen when we are searching up the tree
2364 * and these conditions mean that we need to keep climbing.
2365 */
2366 error = SET_ERROR(ESRCH);
2367 } else if (lvl == 0) {
2368 dnode_phys_t *dnp = data;
2369
2370 ASSERT(dn->dn_type == DMU_OT_DNODE);
2371 ASSERT(!(flags & DNODE_FIND_BACKWARDS));
2372
2373 for (i = (*offset >> DNODE_SHIFT) & (blkfill - 1);
2374 i < blkfill; i += dnp[i].dn_extra_slots + 1) {
2375 if ((dnp[i].dn_type == DMU_OT_NONE) == hole)
2376 break;
2377 }
2378
2379 if (i == blkfill)
2380 error = SET_ERROR(ESRCH);
2381
2382 *offset = (*offset & ~(DNODE_BLOCK_SIZE - 1)) +
2383 (i << DNODE_SHIFT);
2384 } else {
2385 blkptr_t *bp = data;
2386 uint64_t start = *offset;
2387 span = (lvl - 1) * epbs + dn->dn_datablkshift;
2388 minfill = 0;
2389 maxfill = blkfill << ((lvl - 1) * epbs);
2390
2391 if (hole)
2392 maxfill--;
2393 else
2394 minfill++;
2395
2396 *offset = *offset >> span;
2397 for (i = BF64_GET(*offset, 0, epbs);
2398 i >= 0 && i < epb; i += inc) {
2399 if (BP_GET_FILL(&bp[i]) >= minfill &&
2400 BP_GET_FILL(&bp[i]) <= maxfill &&
2401 (hole || bp[i].blk_birth > txg))
2402 break;
2403 if (inc > 0 || *offset > 0)
2404 *offset += inc;
2405 }
2406 *offset = *offset << span;
2407 if (inc < 0) {
2408 /* traversing backwards; position offset at the end */
2409 ASSERT3U(*offset, <=, start);
2410 *offset = MIN(*offset + (1ULL << span) - 1, start);
2411 } else if (*offset < start) {
2412 *offset = start;
2413 }
2414 if (i < 0 || i >= epb)
2415 error = SET_ERROR(ESRCH);
2416 }
2417
2418 if (db)
2419 dbuf_rele(db, FTAG);
2420
2421 return (error);
2422 }
2423
2424 /*
2425 * Find the next hole, data, or sparse region at or after *offset.
2426 * The value 'blkfill' tells us how many items we expect to find
2427 * in an L0 data block; this value is 1 for normal objects,
2428 * DNODES_PER_BLOCK for the meta dnode, and some fraction of
2429 * DNODES_PER_BLOCK when searching for sparse regions thereof.
2430 *
2431 * Examples:
2432 *
2433 * dnode_next_offset(dn, flags, offset, 1, 1, 0);
2434 * Finds the next/previous hole/data in a file.
2435 * Used in dmu_offset_next().
2436 *
2437 * dnode_next_offset(mdn, flags, offset, 0, DNODES_PER_BLOCK, txg);
2438 * Finds the next free/allocated dnode an objset's meta-dnode.
2439 * Only finds objects that have new contents since txg (ie.
2440 * bonus buffer changes and content removal are ignored).
2441 * Used in dmu_object_next().
2442 *
2443 * dnode_next_offset(mdn, DNODE_FIND_HOLE, offset, 2, DNODES_PER_BLOCK >> 2, 0);
2444 * Finds the next L2 meta-dnode bp that's at most 1/4 full.
2445 * Used in dmu_object_alloc().
2446 */
2447 int
2448 dnode_next_offset(dnode_t *dn, int flags, uint64_t *offset,
2449 int minlvl, uint64_t blkfill, uint64_t txg)
2450 {
2451 uint64_t initial_offset = *offset;
2452 int lvl, maxlvl;
2453 int error = 0;
2454
2455 if (!(flags & DNODE_FIND_HAVELOCK))
2456 rw_enter(&dn->dn_struct_rwlock, RW_READER);
2457
2458 if (dn->dn_phys->dn_nlevels == 0) {
2459 error = SET_ERROR(ESRCH);
2460 goto out;
2461 }
2462
2463 if (dn->dn_datablkshift == 0) {
2464 if (*offset < dn->dn_datablksz) {
2465 if (flags & DNODE_FIND_HOLE)
2466 *offset = dn->dn_datablksz;
2467 } else {
2468 error = SET_ERROR(ESRCH);
2469 }
2470 goto out;
2471 }
2472
2473 maxlvl = dn->dn_phys->dn_nlevels;
2474
2475 for (lvl = minlvl; lvl <= maxlvl; lvl++) {
2476 error = dnode_next_offset_level(dn,
2477 flags, offset, lvl, blkfill, txg);
2478 if (error != ESRCH)
2479 break;
2480 }
2481
2482 while (error == 0 && --lvl >= minlvl) {
2483 error = dnode_next_offset_level(dn,
2484 flags, offset, lvl, blkfill, txg);
2485 }
2486
2487 /*
2488 * There's always a "virtual hole" at the end of the object, even
2489 * if all BP's which physically exist are non-holes.
2490 */
2491 if ((flags & DNODE_FIND_HOLE) && error == ESRCH && txg == 0 &&
2492 minlvl == 1 && blkfill == 1 && !(flags & DNODE_FIND_BACKWARDS)) {
2493 error = 0;
2494 }
2495
2496 if (error == 0 && (flags & DNODE_FIND_BACKWARDS ?
2497 initial_offset < *offset : initial_offset > *offset))
2498 error = SET_ERROR(ESRCH);
2499 out:
2500 if (!(flags & DNODE_FIND_HAVELOCK))
2501 rw_exit(&dn->dn_struct_rwlock);
2502
2503 return (error);
2504 }