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, 2016 by Delphix. All rights reserved.
24 * Copyright (c) 2014 Spectra Logic Corporation, All rights reserved.
25 * Copyright (c) 2014 Integros [integros.com]
26 */
27
28 #include <sys/zfs_context.h>
29 #include <sys/dbuf.h>
30 #include <sys/dnode.h>
31 #include <sys/dmu.h>
32 #include <sys/dmu_impl.h>
33 #include <sys/dmu_tx.h>
34 #include <sys/dmu_objset.h>
35 #include <sys/dsl_dir.h>
36 #include <sys/dsl_dataset.h>
37 #include <sys/spa.h>
38 #include <sys/zio.h>
39 #include <sys/dmu_zfetch.h>
40 #include <sys/range_tree.h>
41
42 static kmem_cache_t *dnode_cache;
43 /*
44 * Define DNODE_STATS to turn on statistic gathering. By default, it is only
45 * turned on when DEBUG is also defined.
46 */
47 #ifdef DEBUG
48 #define DNODE_STATS
49 #endif /* DEBUG */
50
51 #ifdef DNODE_STATS
52 #define DNODE_STAT_ADD(stat) ((stat)++)
53 #else
54 #define DNODE_STAT_ADD(stat) /* nothing */
55 #endif /* DNODE_STATS */
56
57 static dnode_phys_t dnode_phys_zero;
58
59 int zfs_default_bs = SPA_MINBLOCKSHIFT;
60 int zfs_default_ibs = DN_MAX_INDBLKSHIFT;
61
62 #ifdef illumos
63 static kmem_cbrc_t dnode_move(void *, void *, size_t, void *);
64 #endif
65
66 static int
dbuf_compare(const void * x1,const void * x2)67 dbuf_compare(const void *x1, const void *x2)
68 {
69 const dmu_buf_impl_t *d1 = x1;
70 const dmu_buf_impl_t *d2 = x2;
71
72 if (d1->db_level < d2->db_level) {
73 return (-1);
74 }
75 if (d1->db_level > d2->db_level) {
76 return (1);
77 }
78
79 if (d1->db_blkid < d2->db_blkid) {
80 return (-1);
81 }
82 if (d1->db_blkid > d2->db_blkid) {
83 return (1);
84 }
85
86 if (d1->db_state == DB_SEARCH) {
87 ASSERT3S(d2->db_state, !=, DB_SEARCH);
88 return (-1);
89 } else if (d2->db_state == DB_SEARCH) {
90 ASSERT3S(d1->db_state, !=, DB_SEARCH);
91 return (1);
92 }
93
94 if ((uintptr_t)d1 < (uintptr_t)d2) {
95 return (-1);
96 }
97 if ((uintptr_t)d1 > (uintptr_t)d2) {
98 return (1);
99 }
100 return (0);
101 }
102
103 /* ARGSUSED */
104 static int
dnode_cons(void * arg,void * unused,int kmflag)105 dnode_cons(void *arg, void *unused, int kmflag)
106 {
107 dnode_t *dn = arg;
108 int i;
109
110 rw_init(&dn->dn_struct_rwlock, NULL, RW_DEFAULT, NULL);
111 mutex_init(&dn->dn_mtx, NULL, MUTEX_DEFAULT, NULL);
112 mutex_init(&dn->dn_dbufs_mtx, NULL, MUTEX_DEFAULT, NULL);
113 cv_init(&dn->dn_notxholds, NULL, CV_DEFAULT, NULL);
114
115 /*
116 * Every dbuf has a reference, and dropping a tracked reference is
117 * O(number of references), so don't track dn_holds.
118 */
119 refcount_create_untracked(&dn->dn_holds);
120 refcount_create(&dn->dn_tx_holds);
121 list_link_init(&dn->dn_link);
122
123 bzero(&dn->dn_next_nblkptr[0], sizeof (dn->dn_next_nblkptr));
124 bzero(&dn->dn_next_nlevels[0], sizeof (dn->dn_next_nlevels));
125 bzero(&dn->dn_next_indblkshift[0], sizeof (dn->dn_next_indblkshift));
126 bzero(&dn->dn_next_bonustype[0], sizeof (dn->dn_next_bonustype));
127 bzero(&dn->dn_rm_spillblk[0], sizeof (dn->dn_rm_spillblk));
128 bzero(&dn->dn_next_bonuslen[0], sizeof (dn->dn_next_bonuslen));
129 bzero(&dn->dn_next_blksz[0], sizeof (dn->dn_next_blksz));
130
131 for (i = 0; i < TXG_SIZE; i++) {
132 list_link_init(&dn->dn_dirty_link[i]);
133 dn->dn_free_ranges[i] = NULL;
134 list_create(&dn->dn_dirty_records[i],
135 sizeof (dbuf_dirty_record_t),
136 offsetof(dbuf_dirty_record_t, dr_dirty_node));
137 }
138
139 dn->dn_allocated_txg = 0;
140 dn->dn_free_txg = 0;
141 dn->dn_assigned_txg = 0;
142 dn->dn_dirtyctx = 0;
143 dn->dn_dirtyctx_firstset = NULL;
144 dn->dn_bonus = NULL;
145 dn->dn_have_spill = B_FALSE;
146 dn->dn_zio = NULL;
147 dn->dn_oldused = 0;
148 dn->dn_oldflags = 0;
149 dn->dn_olduid = 0;
150 dn->dn_oldgid = 0;
151 dn->dn_newuid = 0;
152 dn->dn_newgid = 0;
153 dn->dn_id_flags = 0;
154
155 dn->dn_dbufs_count = 0;
156 avl_create(&dn->dn_dbufs, dbuf_compare, sizeof (dmu_buf_impl_t),
157 offsetof(dmu_buf_impl_t, db_link));
158
159 dn->dn_moved = 0;
160 POINTER_INVALIDATE(&dn->dn_objset);
161 return (0);
162 }
163
164 /* ARGSUSED */
165 static void
dnode_dest(void * arg,void * unused)166 dnode_dest(void *arg, void *unused)
167 {
168 int i;
169 dnode_t *dn = arg;
170
171 rw_destroy(&dn->dn_struct_rwlock);
172 mutex_destroy(&dn->dn_mtx);
173 mutex_destroy(&dn->dn_dbufs_mtx);
174 cv_destroy(&dn->dn_notxholds);
175 refcount_destroy(&dn->dn_holds);
176 refcount_destroy(&dn->dn_tx_holds);
177 ASSERT(!list_link_active(&dn->dn_link));
178
179 for (i = 0; i < TXG_SIZE; i++) {
180 ASSERT(!list_link_active(&dn->dn_dirty_link[i]));
181 ASSERT3P(dn->dn_free_ranges[i], ==, NULL);
182 list_destroy(&dn->dn_dirty_records[i]);
183 ASSERT0(dn->dn_next_nblkptr[i]);
184 ASSERT0(dn->dn_next_nlevels[i]);
185 ASSERT0(dn->dn_next_indblkshift[i]);
186 ASSERT0(dn->dn_next_bonustype[i]);
187 ASSERT0(dn->dn_rm_spillblk[i]);
188 ASSERT0(dn->dn_next_bonuslen[i]);
189 ASSERT0(dn->dn_next_blksz[i]);
190 }
191
192 ASSERT0(dn->dn_allocated_txg);
193 ASSERT0(dn->dn_free_txg);
194 ASSERT0(dn->dn_assigned_txg);
195 ASSERT0(dn->dn_dirtyctx);
196 ASSERT3P(dn->dn_dirtyctx_firstset, ==, NULL);
197 ASSERT3P(dn->dn_bonus, ==, NULL);
198 ASSERT(!dn->dn_have_spill);
199 ASSERT3P(dn->dn_zio, ==, NULL);
200 ASSERT0(dn->dn_oldused);
201 ASSERT0(dn->dn_oldflags);
202 ASSERT0(dn->dn_olduid);
203 ASSERT0(dn->dn_oldgid);
204 ASSERT0(dn->dn_newuid);
205 ASSERT0(dn->dn_newgid);
206 ASSERT0(dn->dn_id_flags);
207
208 ASSERT0(dn->dn_dbufs_count);
209 avl_destroy(&dn->dn_dbufs);
210 }
211
212 void
dnode_init(void)213 dnode_init(void)
214 {
215 ASSERT(dnode_cache == NULL);
216 dnode_cache = kmem_cache_create("dnode_t",
217 sizeof (dnode_t),
218 0, dnode_cons, dnode_dest, NULL, NULL, NULL, 0);
219 kmem_cache_set_move(dnode_cache, dnode_move);
220 }
221
222 void
dnode_fini(void)223 dnode_fini(void)
224 {
225 kmem_cache_destroy(dnode_cache);
226 dnode_cache = NULL;
227 }
228
229
230 #ifdef ZFS_DEBUG
231 void
dnode_verify(dnode_t * dn)232 dnode_verify(dnode_t *dn)
233 {
234 int drop_struct_lock = FALSE;
235
236 ASSERT(dn->dn_phys);
237 ASSERT(dn->dn_objset);
238 ASSERT(dn->dn_handle->dnh_dnode == dn);
239
240 ASSERT(DMU_OT_IS_VALID(dn->dn_phys->dn_type));
241
242 if (!(zfs_flags & ZFS_DEBUG_DNODE_VERIFY))
243 return;
244
245 if (!RW_WRITE_HELD(&dn->dn_struct_rwlock)) {
246 rw_enter(&dn->dn_struct_rwlock, RW_READER);
247 drop_struct_lock = TRUE;
248 }
249 if (dn->dn_phys->dn_type != DMU_OT_NONE || dn->dn_allocated_txg != 0) {
250 int i;
251 ASSERT3U(dn->dn_indblkshift, >=, 0);
252 ASSERT3U(dn->dn_indblkshift, <=, SPA_MAXBLOCKSHIFT);
253 if (dn->dn_datablkshift) {
254 ASSERT3U(dn->dn_datablkshift, >=, SPA_MINBLOCKSHIFT);
255 ASSERT3U(dn->dn_datablkshift, <=, SPA_MAXBLOCKSHIFT);
256 ASSERT3U(1<<dn->dn_datablkshift, ==, dn->dn_datablksz);
257 }
258 ASSERT3U(dn->dn_nlevels, <=, 30);
259 ASSERT(DMU_OT_IS_VALID(dn->dn_type));
260 ASSERT3U(dn->dn_nblkptr, >=, 1);
261 ASSERT3U(dn->dn_nblkptr, <=, DN_MAX_NBLKPTR);
262 ASSERT3U(dn->dn_bonuslen, <=, DN_MAX_BONUSLEN);
263 ASSERT3U(dn->dn_datablksz, ==,
264 dn->dn_datablkszsec << SPA_MINBLOCKSHIFT);
265 ASSERT3U(ISP2(dn->dn_datablksz), ==, dn->dn_datablkshift != 0);
266 ASSERT3U((dn->dn_nblkptr - 1) * sizeof (blkptr_t) +
267 dn->dn_bonuslen, <=, DN_MAX_BONUSLEN);
268 for (i = 0; i < TXG_SIZE; i++) {
269 ASSERT3U(dn->dn_next_nlevels[i], <=, dn->dn_nlevels);
270 }
271 }
272 if (dn->dn_phys->dn_type != DMU_OT_NONE)
273 ASSERT3U(dn->dn_phys->dn_nlevels, <=, dn->dn_nlevels);
274 ASSERT(DMU_OBJECT_IS_SPECIAL(dn->dn_object) || dn->dn_dbuf != NULL);
275 if (dn->dn_dbuf != NULL) {
276 ASSERT3P(dn->dn_phys, ==,
277 (dnode_phys_t *)dn->dn_dbuf->db.db_data +
278 (dn->dn_object % (dn->dn_dbuf->db.db_size >> DNODE_SHIFT)));
279 }
280 if (drop_struct_lock)
281 rw_exit(&dn->dn_struct_rwlock);
282 }
283 #endif
284
285 void
dnode_byteswap(dnode_phys_t * dnp)286 dnode_byteswap(dnode_phys_t *dnp)
287 {
288 uint64_t *buf64 = (void*)&dnp->dn_blkptr;
289 int i;
290
291 if (dnp->dn_type == DMU_OT_NONE) {
292 bzero(dnp, sizeof (dnode_phys_t));
293 return;
294 }
295
296 dnp->dn_datablkszsec = BSWAP_16(dnp->dn_datablkszsec);
297 dnp->dn_bonuslen = BSWAP_16(dnp->dn_bonuslen);
298 dnp->dn_maxblkid = BSWAP_64(dnp->dn_maxblkid);
299 dnp->dn_used = BSWAP_64(dnp->dn_used);
300
301 /*
302 * dn_nblkptr is only one byte, so it's OK to read it in either
303 * byte order. We can't read dn_bouslen.
304 */
305 ASSERT(dnp->dn_indblkshift <= SPA_MAXBLOCKSHIFT);
306 ASSERT(dnp->dn_nblkptr <= DN_MAX_NBLKPTR);
307 for (i = 0; i < dnp->dn_nblkptr * sizeof (blkptr_t)/8; i++)
308 buf64[i] = BSWAP_64(buf64[i]);
309
310 /*
311 * OK to check dn_bonuslen for zero, because it won't matter if
312 * we have the wrong byte order. This is necessary because the
313 * dnode dnode is smaller than a regular dnode.
314 */
315 if (dnp->dn_bonuslen != 0) {
316 /*
317 * Note that the bonus length calculated here may be
318 * longer than the actual bonus buffer. This is because
319 * we always put the bonus buffer after the last block
320 * pointer (instead of packing it against the end of the
321 * dnode buffer).
322 */
323 int off = (dnp->dn_nblkptr-1) * sizeof (blkptr_t);
324 size_t len = DN_MAX_BONUSLEN - off;
325 ASSERT(DMU_OT_IS_VALID(dnp->dn_bonustype));
326 dmu_object_byteswap_t byteswap =
327 DMU_OT_BYTESWAP(dnp->dn_bonustype);
328 dmu_ot_byteswap[byteswap].ob_func(dnp->dn_bonus + off, len);
329 }
330
331 /* Swap SPILL block if we have one */
332 if (dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR)
333 byteswap_uint64_array(&dnp->dn_spill, sizeof (blkptr_t));
334
335 }
336
337 void
dnode_buf_byteswap(void * vbuf,size_t size)338 dnode_buf_byteswap(void *vbuf, size_t size)
339 {
340 dnode_phys_t *buf = vbuf;
341 int i;
342
343 ASSERT3U(sizeof (dnode_phys_t), ==, (1<<DNODE_SHIFT));
344 ASSERT((size & (sizeof (dnode_phys_t)-1)) == 0);
345
346 size >>= DNODE_SHIFT;
347 for (i = 0; i < size; i++) {
348 dnode_byteswap(buf);
349 buf++;
350 }
351 }
352
353 void
dnode_setbonuslen(dnode_t * dn,int newsize,dmu_tx_t * tx)354 dnode_setbonuslen(dnode_t *dn, int newsize, dmu_tx_t *tx)
355 {
356 ASSERT3U(refcount_count(&dn->dn_holds), >=, 1);
357
358 dnode_setdirty(dn, tx);
359 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
360 ASSERT3U(newsize, <=, DN_MAX_BONUSLEN -
361 (dn->dn_nblkptr-1) * sizeof (blkptr_t));
362 dn->dn_bonuslen = newsize;
363 if (newsize == 0)
364 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = DN_ZERO_BONUSLEN;
365 else
366 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = dn->dn_bonuslen;
367 rw_exit(&dn->dn_struct_rwlock);
368 }
369
370 void
dnode_setbonus_type(dnode_t * dn,dmu_object_type_t newtype,dmu_tx_t * tx)371 dnode_setbonus_type(dnode_t *dn, dmu_object_type_t newtype, dmu_tx_t *tx)
372 {
373 ASSERT3U(refcount_count(&dn->dn_holds), >=, 1);
374 dnode_setdirty(dn, tx);
375 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
376 dn->dn_bonustype = newtype;
377 dn->dn_next_bonustype[tx->tx_txg & TXG_MASK] = dn->dn_bonustype;
378 rw_exit(&dn->dn_struct_rwlock);
379 }
380
381 void
dnode_rm_spill(dnode_t * dn,dmu_tx_t * tx)382 dnode_rm_spill(dnode_t *dn, dmu_tx_t *tx)
383 {
384 ASSERT3U(refcount_count(&dn->dn_holds), >=, 1);
385 ASSERT(RW_WRITE_HELD(&dn->dn_struct_rwlock));
386 dnode_setdirty(dn, tx);
387 dn->dn_rm_spillblk[tx->tx_txg&TXG_MASK] = DN_KILL_SPILLBLK;
388 dn->dn_have_spill = B_FALSE;
389 }
390
391 static void
dnode_setdblksz(dnode_t * dn,int size)392 dnode_setdblksz(dnode_t *dn, int size)
393 {
394 ASSERT0(P2PHASE(size, SPA_MINBLOCKSIZE));
395 ASSERT3U(size, <=, SPA_MAXBLOCKSIZE);
396 ASSERT3U(size, >=, SPA_MINBLOCKSIZE);
397 ASSERT3U(size >> SPA_MINBLOCKSHIFT, <,
398 1<<(sizeof (dn->dn_phys->dn_datablkszsec) * 8));
399 dn->dn_datablksz = size;
400 dn->dn_datablkszsec = size >> SPA_MINBLOCKSHIFT;
401 dn->dn_datablkshift = ISP2(size) ? highbit64(size - 1) : 0;
402 }
403
404 static dnode_t *
dnode_create(objset_t * os,dnode_phys_t * dnp,dmu_buf_impl_t * db,uint64_t object,dnode_handle_t * dnh)405 dnode_create(objset_t *os, dnode_phys_t *dnp, dmu_buf_impl_t *db,
406 uint64_t object, dnode_handle_t *dnh)
407 {
408 dnode_t *dn;
409
410 dn = kmem_cache_alloc(dnode_cache, KM_SLEEP);
411 ASSERT(!POINTER_IS_VALID(dn->dn_objset));
412 dn->dn_moved = 0;
413
414 /*
415 * Defer setting dn_objset until the dnode is ready to be a candidate
416 * for the dnode_move() callback.
417 */
418 dn->dn_object = object;
419 dn->dn_dbuf = db;
420 dn->dn_handle = dnh;
421 dn->dn_phys = dnp;
422
423 if (dnp->dn_datablkszsec) {
424 dnode_setdblksz(dn, dnp->dn_datablkszsec << SPA_MINBLOCKSHIFT);
425 } else {
426 dn->dn_datablksz = 0;
427 dn->dn_datablkszsec = 0;
428 dn->dn_datablkshift = 0;
429 }
430 dn->dn_indblkshift = dnp->dn_indblkshift;
431 dn->dn_nlevels = dnp->dn_nlevels;
432 dn->dn_type = dnp->dn_type;
433 dn->dn_nblkptr = dnp->dn_nblkptr;
434 dn->dn_checksum = dnp->dn_checksum;
435 dn->dn_compress = dnp->dn_compress;
436 dn->dn_bonustype = dnp->dn_bonustype;
437 dn->dn_bonuslen = dnp->dn_bonuslen;
438 dn->dn_maxblkid = dnp->dn_maxblkid;
439 dn->dn_have_spill = ((dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) != 0);
440 dn->dn_id_flags = 0;
441
442 dmu_zfetch_init(&dn->dn_zfetch, dn);
443
444 ASSERT(DMU_OT_IS_VALID(dn->dn_phys->dn_type));
445
446 mutex_enter(&os->os_lock);
447 if (dnh->dnh_dnode != NULL) {
448 /* Lost the allocation race. */
449 mutex_exit(&os->os_lock);
450 #ifdef __NetBSD__
451 dmu_zfetch_fini(&dn->dn_zfetch);
452 #endif
453 kmem_cache_free(dnode_cache, dn);
454 return (dnh->dnh_dnode);
455 }
456
457 /*
458 * Exclude special dnodes from os_dnodes so an empty os_dnodes
459 * signifies that the special dnodes have no references from
460 * their children (the entries in os_dnodes). This allows
461 * dnode_destroy() to easily determine if the last child has
462 * been removed and then complete eviction of the objset.
463 */
464 if (!DMU_OBJECT_IS_SPECIAL(object))
465 list_insert_head(&os->os_dnodes, dn);
466 membar_producer();
467
468 /*
469 * Everything else must be valid before assigning dn_objset
470 * makes the dnode eligible for dnode_move().
471 */
472 dn->dn_objset = os;
473
474 dnh->dnh_dnode = dn;
475 mutex_exit(&os->os_lock);
476
477 arc_space_consume(sizeof (dnode_t), ARC_SPACE_OTHER);
478 return (dn);
479 }
480
481 /*
482 * Caller must be holding the dnode handle, which is released upon return.
483 */
484 static void
dnode_destroy(dnode_t * dn)485 dnode_destroy(dnode_t *dn)
486 {
487 objset_t *os = dn->dn_objset;
488 boolean_t complete_os_eviction = B_FALSE;
489
490 ASSERT((dn->dn_id_flags & DN_ID_NEW_EXIST) == 0);
491
492 mutex_enter(&os->os_lock);
493 POINTER_INVALIDATE(&dn->dn_objset);
494 if (!DMU_OBJECT_IS_SPECIAL(dn->dn_object)) {
495 list_remove(&os->os_dnodes, dn);
496 complete_os_eviction =
497 list_is_empty(&os->os_dnodes) &&
498 list_link_active(&os->os_evicting_node);
499 }
500 mutex_exit(&os->os_lock);
501
502 /* the dnode can no longer move, so we can release the handle */
503 zrl_remove(&dn->dn_handle->dnh_zrlock);
504
505 dn->dn_allocated_txg = 0;
506 dn->dn_free_txg = 0;
507 dn->dn_assigned_txg = 0;
508
509 dn->dn_dirtyctx = 0;
510 if (dn->dn_dirtyctx_firstset != NULL) {
511 kmem_free(dn->dn_dirtyctx_firstset, 1);
512 dn->dn_dirtyctx_firstset = NULL;
513 }
514 if (dn->dn_bonus != NULL) {
515 mutex_enter(&dn->dn_bonus->db_mtx);
516 dbuf_destroy(dn->dn_bonus);
517 dn->dn_bonus = NULL;
518 }
519 dn->dn_zio = NULL;
520
521 dn->dn_have_spill = B_FALSE;
522 dn->dn_oldused = 0;
523 dn->dn_oldflags = 0;
524 dn->dn_olduid = 0;
525 dn->dn_oldgid = 0;
526 dn->dn_newuid = 0;
527 dn->dn_newgid = 0;
528 dn->dn_id_flags = 0;
529
530 dmu_zfetch_fini(&dn->dn_zfetch);
531 kmem_cache_free(dnode_cache, dn);
532 arc_space_return(sizeof (dnode_t), ARC_SPACE_OTHER);
533
534 if (complete_os_eviction)
535 dmu_objset_evict_done(os);
536 }
537
538 void
dnode_allocate(dnode_t * dn,dmu_object_type_t ot,int blocksize,int ibs,dmu_object_type_t bonustype,int bonuslen,dmu_tx_t * tx)539 dnode_allocate(dnode_t *dn, dmu_object_type_t ot, int blocksize, int ibs,
540 dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx)
541 {
542 int i;
543
544 ASSERT3U(blocksize, <=,
545 spa_maxblocksize(dmu_objset_spa(dn->dn_objset)));
546 if (blocksize == 0)
547 blocksize = 1 << zfs_default_bs;
548 else
549 blocksize = P2ROUNDUP(blocksize, SPA_MINBLOCKSIZE);
550
551 if (ibs == 0)
552 ibs = zfs_default_ibs;
553
554 ibs = MIN(MAX(ibs, DN_MIN_INDBLKSHIFT), DN_MAX_INDBLKSHIFT);
555
556 dprintf("os=%p obj=%llu txg=%llu blocksize=%d ibs=%d\n", dn->dn_objset,
557 dn->dn_object, tx->tx_txg, blocksize, ibs);
558
559 ASSERT(dn->dn_type == DMU_OT_NONE);
560 ASSERT(bcmp(dn->dn_phys, &dnode_phys_zero, sizeof (dnode_phys_t)) == 0);
561 ASSERT(dn->dn_phys->dn_type == DMU_OT_NONE);
562 ASSERT(ot != DMU_OT_NONE);
563 ASSERT(DMU_OT_IS_VALID(ot));
564 ASSERT((bonustype == DMU_OT_NONE && bonuslen == 0) ||
565 (bonustype == DMU_OT_SA && bonuslen == 0) ||
566 (bonustype != DMU_OT_NONE && bonuslen != 0));
567 ASSERT(DMU_OT_IS_VALID(bonustype));
568 ASSERT3U(bonuslen, <=, DN_MAX_BONUSLEN);
569 ASSERT(dn->dn_type == DMU_OT_NONE);
570 ASSERT0(dn->dn_maxblkid);
571 ASSERT0(dn->dn_allocated_txg);
572 ASSERT0(dn->dn_assigned_txg);
573 ASSERT(refcount_is_zero(&dn->dn_tx_holds));
574 ASSERT3U(refcount_count(&dn->dn_holds), <=, 1);
575 ASSERT(avl_is_empty(&dn->dn_dbufs));
576
577 for (i = 0; i < TXG_SIZE; i++) {
578 ASSERT0(dn->dn_next_nblkptr[i]);
579 ASSERT0(dn->dn_next_nlevels[i]);
580 ASSERT0(dn->dn_next_indblkshift[i]);
581 ASSERT0(dn->dn_next_bonuslen[i]);
582 ASSERT0(dn->dn_next_bonustype[i]);
583 ASSERT0(dn->dn_rm_spillblk[i]);
584 ASSERT0(dn->dn_next_blksz[i]);
585 ASSERT(!list_link_active(&dn->dn_dirty_link[i]));
586 ASSERT3P(list_head(&dn->dn_dirty_records[i]), ==, NULL);
587 ASSERT3P(dn->dn_free_ranges[i], ==, NULL);
588 }
589
590 dn->dn_type = ot;
591 dnode_setdblksz(dn, blocksize);
592 dn->dn_indblkshift = ibs;
593 dn->dn_nlevels = 1;
594 if (bonustype == DMU_OT_SA) /* Maximize bonus space for SA */
595 dn->dn_nblkptr = 1;
596 else
597 dn->dn_nblkptr = 1 +
598 ((DN_MAX_BONUSLEN - bonuslen) >> SPA_BLKPTRSHIFT);
599 dn->dn_bonustype = bonustype;
600 dn->dn_bonuslen = bonuslen;
601 dn->dn_checksum = ZIO_CHECKSUM_INHERIT;
602 dn->dn_compress = ZIO_COMPRESS_INHERIT;
603 dn->dn_dirtyctx = 0;
604
605 dn->dn_free_txg = 0;
606 if (dn->dn_dirtyctx_firstset) {
607 kmem_free(dn->dn_dirtyctx_firstset, 1);
608 dn->dn_dirtyctx_firstset = NULL;
609 }
610
611 dn->dn_allocated_txg = tx->tx_txg;
612 dn->dn_id_flags = 0;
613
614 dnode_setdirty(dn, tx);
615 dn->dn_next_indblkshift[tx->tx_txg & TXG_MASK] = ibs;
616 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = dn->dn_bonuslen;
617 dn->dn_next_bonustype[tx->tx_txg & TXG_MASK] = dn->dn_bonustype;
618 dn->dn_next_blksz[tx->tx_txg & TXG_MASK] = dn->dn_datablksz;
619 }
620
621 void
dnode_reallocate(dnode_t * dn,dmu_object_type_t ot,int blocksize,dmu_object_type_t bonustype,int bonuslen,dmu_tx_t * tx)622 dnode_reallocate(dnode_t *dn, dmu_object_type_t ot, int blocksize,
623 dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx)
624 {
625 int nblkptr;
626
627 ASSERT3U(blocksize, >=, SPA_MINBLOCKSIZE);
628 ASSERT3U(blocksize, <=,
629 spa_maxblocksize(dmu_objset_spa(dn->dn_objset)));
630 ASSERT0(blocksize % SPA_MINBLOCKSIZE);
631 ASSERT(dn->dn_object != DMU_META_DNODE_OBJECT || dmu_tx_private_ok(tx));
632 ASSERT(tx->tx_txg != 0);
633 ASSERT((bonustype == DMU_OT_NONE && bonuslen == 0) ||
634 (bonustype != DMU_OT_NONE && bonuslen != 0) ||
635 (bonustype == DMU_OT_SA && bonuslen == 0));
636 ASSERT(DMU_OT_IS_VALID(bonustype));
637 ASSERT3U(bonuslen, <=, DN_MAX_BONUSLEN);
638
639 /* clean up any unreferenced dbufs */
640 dnode_evict_dbufs(dn);
641
642 dn->dn_id_flags = 0;
643
644 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
645 dnode_setdirty(dn, tx);
646 if (dn->dn_datablksz != blocksize) {
647 /* change blocksize */
648 ASSERT(dn->dn_maxblkid == 0 &&
649 (BP_IS_HOLE(&dn->dn_phys->dn_blkptr[0]) ||
650 dnode_block_freed(dn, 0)));
651 dnode_setdblksz(dn, blocksize);
652 dn->dn_next_blksz[tx->tx_txg&TXG_MASK] = blocksize;
653 }
654 if (dn->dn_bonuslen != bonuslen)
655 dn->dn_next_bonuslen[tx->tx_txg&TXG_MASK] = bonuslen;
656
657 if (bonustype == DMU_OT_SA) /* Maximize bonus space for SA */
658 nblkptr = 1;
659 else
660 nblkptr = 1 + ((DN_MAX_BONUSLEN - bonuslen) >> SPA_BLKPTRSHIFT);
661 if (dn->dn_bonustype != bonustype)
662 dn->dn_next_bonustype[tx->tx_txg&TXG_MASK] = bonustype;
663 if (dn->dn_nblkptr != nblkptr)
664 dn->dn_next_nblkptr[tx->tx_txg&TXG_MASK] = nblkptr;
665 if (dn->dn_phys->dn_flags & DNODE_FLAG_SPILL_BLKPTR) {
666 dbuf_rm_spill(dn, tx);
667 dnode_rm_spill(dn, tx);
668 }
669 rw_exit(&dn->dn_struct_rwlock);
670
671 /* change type */
672 dn->dn_type = ot;
673
674 /* change bonus size and type */
675 mutex_enter(&dn->dn_mtx);
676 dn->dn_bonustype = bonustype;
677 dn->dn_bonuslen = bonuslen;
678 dn->dn_nblkptr = nblkptr;
679 dn->dn_checksum = ZIO_CHECKSUM_INHERIT;
680 dn->dn_compress = ZIO_COMPRESS_INHERIT;
681 ASSERT3U(dn->dn_nblkptr, <=, DN_MAX_NBLKPTR);
682
683 /* fix up the bonus db_size */
684 if (dn->dn_bonus) {
685 dn->dn_bonus->db.db_size =
686 DN_MAX_BONUSLEN - (dn->dn_nblkptr-1) * sizeof (blkptr_t);
687 ASSERT(dn->dn_bonuslen <= dn->dn_bonus->db.db_size);
688 }
689
690 dn->dn_allocated_txg = tx->tx_txg;
691 mutex_exit(&dn->dn_mtx);
692 }
693
694 #ifdef DNODE_STATS
695 static struct {
696 uint64_t dms_dnode_invalid;
697 uint64_t dms_dnode_recheck1;
698 uint64_t dms_dnode_recheck2;
699 uint64_t dms_dnode_special;
700 uint64_t dms_dnode_handle;
701 uint64_t dms_dnode_rwlock;
702 uint64_t dms_dnode_active;
703 } dnode_move_stats;
704 #endif /* DNODE_STATS */
705
706 static void
dnode_move_impl(dnode_t * odn,dnode_t * ndn)707 dnode_move_impl(dnode_t *odn, dnode_t *ndn)
708 {
709 int i;
710
711 ASSERT(!RW_LOCK_HELD(&odn->dn_struct_rwlock));
712 ASSERT(MUTEX_NOT_HELD(&odn->dn_mtx));
713 ASSERT(MUTEX_NOT_HELD(&odn->dn_dbufs_mtx));
714 ASSERT(!RW_LOCK_HELD(&odn->dn_zfetch.zf_rwlock));
715
716 /* Copy fields. */
717 ndn->dn_objset = odn->dn_objset;
718 ndn->dn_object = odn->dn_object;
719 ndn->dn_dbuf = odn->dn_dbuf;
720 ndn->dn_handle = odn->dn_handle;
721 ndn->dn_phys = odn->dn_phys;
722 ndn->dn_type = odn->dn_type;
723 ndn->dn_bonuslen = odn->dn_bonuslen;
724 ndn->dn_bonustype = odn->dn_bonustype;
725 ndn->dn_nblkptr = odn->dn_nblkptr;
726 ndn->dn_checksum = odn->dn_checksum;
727 ndn->dn_compress = odn->dn_compress;
728 ndn->dn_nlevels = odn->dn_nlevels;
729 ndn->dn_indblkshift = odn->dn_indblkshift;
730 ndn->dn_datablkshift = odn->dn_datablkshift;
731 ndn->dn_datablkszsec = odn->dn_datablkszsec;
732 ndn->dn_datablksz = odn->dn_datablksz;
733 ndn->dn_maxblkid = odn->dn_maxblkid;
734 bcopy(&odn->dn_next_nblkptr[0], &ndn->dn_next_nblkptr[0],
735 sizeof (odn->dn_next_nblkptr));
736 bcopy(&odn->dn_next_nlevels[0], &ndn->dn_next_nlevels[0],
737 sizeof (odn->dn_next_nlevels));
738 bcopy(&odn->dn_next_indblkshift[0], &ndn->dn_next_indblkshift[0],
739 sizeof (odn->dn_next_indblkshift));
740 bcopy(&odn->dn_next_bonustype[0], &ndn->dn_next_bonustype[0],
741 sizeof (odn->dn_next_bonustype));
742 bcopy(&odn->dn_rm_spillblk[0], &ndn->dn_rm_spillblk[0],
743 sizeof (odn->dn_rm_spillblk));
744 bcopy(&odn->dn_next_bonuslen[0], &ndn->dn_next_bonuslen[0],
745 sizeof (odn->dn_next_bonuslen));
746 bcopy(&odn->dn_next_blksz[0], &ndn->dn_next_blksz[0],
747 sizeof (odn->dn_next_blksz));
748 for (i = 0; i < TXG_SIZE; i++) {
749 list_move_tail(&ndn->dn_dirty_records[i],
750 &odn->dn_dirty_records[i]);
751 }
752 bcopy(&odn->dn_free_ranges[0], &ndn->dn_free_ranges[0],
753 sizeof (odn->dn_free_ranges));
754 ndn->dn_allocated_txg = odn->dn_allocated_txg;
755 ndn->dn_free_txg = odn->dn_free_txg;
756 ndn->dn_assigned_txg = odn->dn_assigned_txg;
757 ndn->dn_dirtyctx = odn->dn_dirtyctx;
758 ndn->dn_dirtyctx_firstset = odn->dn_dirtyctx_firstset;
759 ASSERT(refcount_count(&odn->dn_tx_holds) == 0);
760 refcount_transfer(&ndn->dn_holds, &odn->dn_holds);
761 ASSERT(avl_is_empty(&ndn->dn_dbufs));
762 avl_swap(&ndn->dn_dbufs, &odn->dn_dbufs);
763 ndn->dn_dbufs_count = odn->dn_dbufs_count;
764 ndn->dn_bonus = odn->dn_bonus;
765 ndn->dn_have_spill = odn->dn_have_spill;
766 ndn->dn_zio = odn->dn_zio;
767 ndn->dn_oldused = odn->dn_oldused;
768 ndn->dn_oldflags = odn->dn_oldflags;
769 ndn->dn_olduid = odn->dn_olduid;
770 ndn->dn_oldgid = odn->dn_oldgid;
771 ndn->dn_newuid = odn->dn_newuid;
772 ndn->dn_newgid = odn->dn_newgid;
773 ndn->dn_id_flags = odn->dn_id_flags;
774 dmu_zfetch_init(&ndn->dn_zfetch, NULL);
775 list_move_tail(&ndn->dn_zfetch.zf_stream, &odn->dn_zfetch.zf_stream);
776 ndn->dn_zfetch.zf_dnode = odn->dn_zfetch.zf_dnode;
777
778 /*
779 * Update back pointers. Updating the handle fixes the back pointer of
780 * every descendant dbuf as well as the bonus dbuf.
781 */
782 ASSERT(ndn->dn_handle->dnh_dnode == odn);
783 ndn->dn_handle->dnh_dnode = ndn;
784 if (ndn->dn_zfetch.zf_dnode == odn) {
785 ndn->dn_zfetch.zf_dnode = ndn;
786 }
787
788 /*
789 * Invalidate the original dnode by clearing all of its back pointers.
790 */
791 odn->dn_dbuf = NULL;
792 odn->dn_handle = NULL;
793 avl_create(&odn->dn_dbufs, dbuf_compare, sizeof (dmu_buf_impl_t),
794 offsetof(dmu_buf_impl_t, db_link));
795 odn->dn_dbufs_count = 0;
796 odn->dn_bonus = NULL;
797 odn->dn_zfetch.zf_dnode = NULL;
798
799 /*
800 * Set the low bit of the objset pointer to ensure that dnode_move()
801 * recognizes the dnode as invalid in any subsequent callback.
802 */
803 POINTER_INVALIDATE(&odn->dn_objset);
804
805 /*
806 * Satisfy the destructor.
807 */
808 for (i = 0; i < TXG_SIZE; i++) {
809 list_create(&odn->dn_dirty_records[i],
810 sizeof (dbuf_dirty_record_t),
811 offsetof(dbuf_dirty_record_t, dr_dirty_node));
812 odn->dn_free_ranges[i] = NULL;
813 odn->dn_next_nlevels[i] = 0;
814 odn->dn_next_indblkshift[i] = 0;
815 odn->dn_next_bonustype[i] = 0;
816 odn->dn_rm_spillblk[i] = 0;
817 odn->dn_next_bonuslen[i] = 0;
818 odn->dn_next_blksz[i] = 0;
819 }
820 odn->dn_allocated_txg = 0;
821 odn->dn_free_txg = 0;
822 odn->dn_assigned_txg = 0;
823 odn->dn_dirtyctx = 0;
824 odn->dn_dirtyctx_firstset = NULL;
825 odn->dn_have_spill = B_FALSE;
826 odn->dn_zio = NULL;
827 odn->dn_oldused = 0;
828 odn->dn_oldflags = 0;
829 odn->dn_olduid = 0;
830 odn->dn_oldgid = 0;
831 odn->dn_newuid = 0;
832 odn->dn_newgid = 0;
833 odn->dn_id_flags = 0;
834
835 /*
836 * Mark the dnode.
837 */
838 ndn->dn_moved = 1;
839 odn->dn_moved = (uint8_t)-1;
840 }
841
842 #ifdef illumos
843 #ifdef _KERNEL
844 /*ARGSUSED*/
845 static kmem_cbrc_t
dnode_move(void * buf,void * newbuf,size_t size,void * arg)846 dnode_move(void *buf, void *newbuf, size_t size, void *arg)
847 {
848 dnode_t *odn = buf, *ndn = newbuf;
849 objset_t *os;
850 int64_t refcount;
851 uint32_t dbufs;
852
853 /*
854 * The dnode is on the objset's list of known dnodes if the objset
855 * pointer is valid. We set the low bit of the objset pointer when
856 * freeing the dnode to invalidate it, and the memory patterns written
857 * by kmem (baddcafe and deadbeef) set at least one of the two low bits.
858 * A newly created dnode sets the objset pointer last of all to indicate
859 * that the dnode is known and in a valid state to be moved by this
860 * function.
861 */
862 os = odn->dn_objset;
863 if (!POINTER_IS_VALID(os)) {
864 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_invalid);
865 return (KMEM_CBRC_DONT_KNOW);
866 }
867
868 /*
869 * Ensure that the objset does not go away during the move.
870 */
871 rw_enter(&os_lock, RW_WRITER);
872 if (os != odn->dn_objset) {
873 rw_exit(&os_lock);
874 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_recheck1);
875 return (KMEM_CBRC_DONT_KNOW);
876 }
877
878 /*
879 * If the dnode is still valid, then so is the objset. We know that no
880 * valid objset can be freed while we hold os_lock, so we can safely
881 * ensure that the objset remains in use.
882 */
883 mutex_enter(&os->os_lock);
884
885 /*
886 * Recheck the objset pointer in case the dnode was removed just before
887 * acquiring the lock.
888 */
889 if (os != odn->dn_objset) {
890 mutex_exit(&os->os_lock);
891 rw_exit(&os_lock);
892 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_recheck2);
893 return (KMEM_CBRC_DONT_KNOW);
894 }
895
896 /*
897 * At this point we know that as long as we hold os->os_lock, the dnode
898 * cannot be freed and fields within the dnode can be safely accessed.
899 * The objset listing this dnode cannot go away as long as this dnode is
900 * on its list.
901 */
902 rw_exit(&os_lock);
903 if (DMU_OBJECT_IS_SPECIAL(odn->dn_object)) {
904 mutex_exit(&os->os_lock);
905 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_special);
906 return (KMEM_CBRC_NO);
907 }
908 ASSERT(odn->dn_dbuf != NULL); /* only "special" dnodes have no parent */
909
910 /*
911 * Lock the dnode handle to prevent the dnode from obtaining any new
912 * holds. This also prevents the descendant dbufs and the bonus dbuf
913 * from accessing the dnode, so that we can discount their holds. The
914 * handle is safe to access because we know that while the dnode cannot
915 * go away, neither can its handle. Once we hold dnh_zrlock, we can
916 * safely move any dnode referenced only by dbufs.
917 */
918 if (!zrl_tryenter(&odn->dn_handle->dnh_zrlock)) {
919 mutex_exit(&os->os_lock);
920 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_handle);
921 return (KMEM_CBRC_LATER);
922 }
923
924 /*
925 * Ensure a consistent view of the dnode's holds and the dnode's dbufs.
926 * We need to guarantee that there is a hold for every dbuf in order to
927 * determine whether the dnode is actively referenced. Falsely matching
928 * a dbuf to an active hold would lead to an unsafe move. It's possible
929 * that a thread already having an active dnode hold is about to add a
930 * dbuf, and we can't compare hold and dbuf counts while the add is in
931 * progress.
932 */
933 if (!rw_tryenter(&odn->dn_struct_rwlock, RW_WRITER)) {
934 zrl_exit(&odn->dn_handle->dnh_zrlock);
935 mutex_exit(&os->os_lock);
936 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_rwlock);
937 return (KMEM_CBRC_LATER);
938 }
939
940 /*
941 * A dbuf may be removed (evicted) without an active dnode hold. In that
942 * case, the dbuf count is decremented under the handle lock before the
943 * dbuf's hold is released. This order ensures that if we count the hold
944 * after the dbuf is removed but before its hold is released, we will
945 * treat the unmatched hold as active and exit safely. If we count the
946 * hold before the dbuf is removed, the hold is discounted, and the
947 * removal is blocked until the move completes.
948 */
949 refcount = refcount_count(&odn->dn_holds);
950 ASSERT(refcount >= 0);
951 dbufs = odn->dn_dbufs_count;
952
953 /* We can't have more dbufs than dnode holds. */
954 ASSERT3U(dbufs, <=, refcount);
955 DTRACE_PROBE3(dnode__move, dnode_t *, odn, int64_t, refcount,
956 uint32_t, dbufs);
957
958 if (refcount > dbufs) {
959 rw_exit(&odn->dn_struct_rwlock);
960 zrl_exit(&odn->dn_handle->dnh_zrlock);
961 mutex_exit(&os->os_lock);
962 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_active);
963 return (KMEM_CBRC_LATER);
964 }
965
966 rw_exit(&odn->dn_struct_rwlock);
967
968 /*
969 * At this point we know that anyone with a hold on the dnode is not
970 * actively referencing it. The dnode is known and in a valid state to
971 * move. We're holding the locks needed to execute the critical section.
972 */
973 dnode_move_impl(odn, ndn);
974
975 list_link_replace(&odn->dn_link, &ndn->dn_link);
976 /* If the dnode was safe to move, the refcount cannot have changed. */
977 ASSERT(refcount == refcount_count(&ndn->dn_holds));
978 ASSERT(dbufs == ndn->dn_dbufs_count);
979 zrl_exit(&ndn->dn_handle->dnh_zrlock); /* handle has moved */
980 mutex_exit(&os->os_lock);
981
982 return (KMEM_CBRC_YES);
983 }
984 #endif /* _KERNEL */
985 #endif /* illumos */
986
987 void
dnode_special_close(dnode_handle_t * dnh)988 dnode_special_close(dnode_handle_t *dnh)
989 {
990 dnode_t *dn = dnh->dnh_dnode;
991
992 /*
993 * Wait for final references to the dnode to clear. This can
994 * only happen if the arc is asyncronously evicting state that
995 * has a hold on this dnode while we are trying to evict this
996 * dnode.
997 */
998 while (refcount_count(&dn->dn_holds) > 0)
999 delay(1);
1000 ASSERT(dn->dn_dbuf == NULL ||
1001 dmu_buf_get_user(&dn->dn_dbuf->db) == NULL);
1002 zrl_add(&dnh->dnh_zrlock);
1003 dnode_destroy(dn); /* implicit zrl_remove() */
1004 zrl_destroy(&dnh->dnh_zrlock);
1005 dnh->dnh_dnode = NULL;
1006 }
1007
1008 void
dnode_special_open(objset_t * os,dnode_phys_t * dnp,uint64_t object,dnode_handle_t * dnh)1009 dnode_special_open(objset_t *os, dnode_phys_t *dnp, uint64_t object,
1010 dnode_handle_t *dnh)
1011 {
1012 dnode_t *dn;
1013
1014 dn = dnode_create(os, dnp, NULL, object, dnh);
1015 zrl_init(&dnh->dnh_zrlock);
1016 DNODE_VERIFY(dn);
1017 }
1018
1019 static void
dnode_buf_evict_async(void * dbu)1020 dnode_buf_evict_async(void *dbu)
1021 {
1022 dnode_children_t *children_dnodes = dbu;
1023 int i;
1024
1025 for (i = 0; i < children_dnodes->dnc_count; i++) {
1026 dnode_handle_t *dnh = &children_dnodes->dnc_children[i];
1027 dnode_t *dn;
1028
1029 /*
1030 * The dnode handle lock guards against the dnode moving to
1031 * another valid address, so there is no need here to guard
1032 * against changes to or from NULL.
1033 */
1034 if (dnh->dnh_dnode == NULL) {
1035 zrl_destroy(&dnh->dnh_zrlock);
1036 continue;
1037 }
1038
1039 zrl_add(&dnh->dnh_zrlock);
1040 dn = dnh->dnh_dnode;
1041 /*
1042 * If there are holds on this dnode, then there should
1043 * be holds on the dnode's containing dbuf as well; thus
1044 * it wouldn't be eligible for eviction and this function
1045 * would not have been called.
1046 */
1047 ASSERT(refcount_is_zero(&dn->dn_holds));
1048 ASSERT(refcount_is_zero(&dn->dn_tx_holds));
1049
1050 dnode_destroy(dn); /* implicit zrl_remove() */
1051 zrl_destroy(&dnh->dnh_zrlock);
1052 dnh->dnh_dnode = NULL;
1053 }
1054 kmem_free(children_dnodes, sizeof (dnode_children_t) +
1055 children_dnodes->dnc_count * sizeof (dnode_handle_t));
1056 }
1057
1058 /*
1059 * errors:
1060 * EINVAL - invalid object number.
1061 * EIO - i/o error.
1062 * succeeds even for free dnodes.
1063 */
1064 int
dnode_hold_impl(objset_t * os,uint64_t object,int flag,void * tag,dnode_t ** dnp)1065 dnode_hold_impl(objset_t *os, uint64_t object, int flag,
1066 void *tag, dnode_t **dnp)
1067 {
1068 int epb, idx, err;
1069 int drop_struct_lock = FALSE;
1070 int type;
1071 uint64_t blk;
1072 dnode_t *mdn, *dn;
1073 dmu_buf_impl_t *db;
1074 dnode_children_t *children_dnodes;
1075 dnode_handle_t *dnh;
1076
1077 /*
1078 * If you are holding the spa config lock as writer, you shouldn't
1079 * be asking the DMU to do *anything* unless it's the root pool
1080 * which may require us to read from the root filesystem while
1081 * holding some (not all) of the locks as writer.
1082 */
1083 ASSERT(spa_config_held(os->os_spa, SCL_ALL, RW_WRITER) == 0 ||
1084 (spa_is_root(os->os_spa) &&
1085 spa_config_held(os->os_spa, SCL_STATE, RW_WRITER)));
1086
1087 if (object == DMU_USERUSED_OBJECT || object == DMU_GROUPUSED_OBJECT) {
1088 dn = (object == DMU_USERUSED_OBJECT) ?
1089 DMU_USERUSED_DNODE(os) : DMU_GROUPUSED_DNODE(os);
1090 if (dn == NULL)
1091 return (SET_ERROR(ENOENT));
1092 type = dn->dn_type;
1093 if ((flag & DNODE_MUST_BE_ALLOCATED) && type == DMU_OT_NONE)
1094 return (SET_ERROR(ENOENT));
1095 if ((flag & DNODE_MUST_BE_FREE) && type != DMU_OT_NONE)
1096 return (SET_ERROR(EEXIST));
1097 DNODE_VERIFY(dn);
1098 (void) refcount_add(&dn->dn_holds, tag);
1099 *dnp = dn;
1100 return (0);
1101 }
1102
1103 if (object == 0 || object >= DN_MAX_OBJECT)
1104 return (SET_ERROR(EINVAL));
1105
1106 mdn = DMU_META_DNODE(os);
1107 ASSERT(mdn->dn_object == DMU_META_DNODE_OBJECT);
1108
1109 DNODE_VERIFY(mdn);
1110
1111 if (!RW_WRITE_HELD(&mdn->dn_struct_rwlock)) {
1112 rw_enter(&mdn->dn_struct_rwlock, RW_READER);
1113 drop_struct_lock = TRUE;
1114 }
1115
1116 blk = dbuf_whichblock(mdn, 0, object * sizeof (dnode_phys_t));
1117
1118 db = dbuf_hold(mdn, blk, FTAG);
1119 if (drop_struct_lock)
1120 rw_exit(&mdn->dn_struct_rwlock);
1121 if (db == NULL)
1122 return (SET_ERROR(EIO));
1123 err = dbuf_read(db, NULL, DB_RF_CANFAIL);
1124 if (err) {
1125 dbuf_rele(db, FTAG);
1126 return (err);
1127 }
1128
1129 ASSERT3U(db->db.db_size, >=, 1<<DNODE_SHIFT);
1130 epb = db->db.db_size >> DNODE_SHIFT;
1131
1132 idx = object & (epb-1);
1133
1134 ASSERT(DB_DNODE(db)->dn_type == DMU_OT_DNODE);
1135 children_dnodes = dmu_buf_get_user(&db->db);
1136 if (children_dnodes == NULL) {
1137 int i;
1138 dnode_children_t *winner;
1139 children_dnodes = kmem_zalloc(sizeof (dnode_children_t) +
1140 epb * sizeof (dnode_handle_t), KM_SLEEP);
1141 children_dnodes->dnc_count = epb;
1142 dnh = &children_dnodes->dnc_children[0];
1143 for (i = 0; i < epb; i++) {
1144 zrl_init(&dnh[i].dnh_zrlock);
1145 }
1146 dmu_buf_init_user(&children_dnodes->dnc_dbu, NULL,
1147 dnode_buf_evict_async, NULL);
1148 winner = dmu_buf_set_user(&db->db, &children_dnodes->dnc_dbu);
1149 if (winner != NULL) {
1150
1151 for (i = 0; i < epb; i++) {
1152 zrl_destroy(&dnh[i].dnh_zrlock);
1153 }
1154
1155 kmem_free(children_dnodes, sizeof (dnode_children_t) +
1156 epb * sizeof (dnode_handle_t));
1157 children_dnodes = winner;
1158 }
1159 }
1160 ASSERT(children_dnodes->dnc_count == epb);
1161
1162 dnh = &children_dnodes->dnc_children[idx];
1163 zrl_add(&dnh->dnh_zrlock);
1164 dn = dnh->dnh_dnode;
1165 if (dn == NULL) {
1166 dnode_phys_t *phys = (dnode_phys_t *)db->db.db_data+idx;
1167
1168 dn = dnode_create(os, phys, db, object, dnh);
1169 }
1170
1171 mutex_enter(&dn->dn_mtx);
1172 type = dn->dn_type;
1173 if (dn->dn_free_txg ||
1174 ((flag & DNODE_MUST_BE_ALLOCATED) && type == DMU_OT_NONE) ||
1175 ((flag & DNODE_MUST_BE_FREE) &&
1176 (type != DMU_OT_NONE || !refcount_is_zero(&dn->dn_holds)))) {
1177 mutex_exit(&dn->dn_mtx);
1178 zrl_remove(&dnh->dnh_zrlock);
1179 dbuf_rele(db, FTAG);
1180 return (type == DMU_OT_NONE ? ENOENT : EEXIST);
1181 }
1182 if (refcount_add(&dn->dn_holds, tag) == 1)
1183 dbuf_add_ref(db, dnh);
1184 mutex_exit(&dn->dn_mtx);
1185
1186 /* Now we can rely on the hold to prevent the dnode from moving. */
1187 zrl_remove(&dnh->dnh_zrlock);
1188
1189 DNODE_VERIFY(dn);
1190 ASSERT3P(dn->dn_dbuf, ==, db);
1191 ASSERT3U(dn->dn_object, ==, object);
1192 dbuf_rele(db, FTAG);
1193
1194 *dnp = dn;
1195 return (0);
1196 }
1197
1198 /*
1199 * Return held dnode if the object is allocated, NULL if not.
1200 */
1201 int
dnode_hold(objset_t * os,uint64_t object,void * tag,dnode_t ** dnp)1202 dnode_hold(objset_t *os, uint64_t object, void *tag, dnode_t **dnp)
1203 {
1204 return (dnode_hold_impl(os, object, DNODE_MUST_BE_ALLOCATED, tag, dnp));
1205 }
1206
1207 /*
1208 * Can only add a reference if there is already at least one
1209 * reference on the dnode. Returns FALSE if unable to add a
1210 * new reference.
1211 */
1212 boolean_t
dnode_add_ref(dnode_t * dn,void * tag)1213 dnode_add_ref(dnode_t *dn, void *tag)
1214 {
1215 mutex_enter(&dn->dn_mtx);
1216 if (refcount_is_zero(&dn->dn_holds)) {
1217 mutex_exit(&dn->dn_mtx);
1218 return (FALSE);
1219 }
1220 VERIFY(1 < refcount_add(&dn->dn_holds, tag));
1221 mutex_exit(&dn->dn_mtx);
1222 return (TRUE);
1223 }
1224
1225 void
dnode_rele(dnode_t * dn,void * tag)1226 dnode_rele(dnode_t *dn, void *tag)
1227 {
1228 mutex_enter(&dn->dn_mtx);
1229 dnode_rele_and_unlock(dn, tag);
1230 }
1231
1232 void
dnode_rele_and_unlock(dnode_t * dn,void * tag)1233 dnode_rele_and_unlock(dnode_t *dn, void *tag)
1234 {
1235 uint64_t refs;
1236 /* Get while the hold prevents the dnode from moving. */
1237 dmu_buf_impl_t *db = dn->dn_dbuf;
1238 dnode_handle_t *dnh = dn->dn_handle;
1239
1240 refs = refcount_remove(&dn->dn_holds, tag);
1241 mutex_exit(&dn->dn_mtx);
1242
1243 /*
1244 * It's unsafe to release the last hold on a dnode by dnode_rele() or
1245 * indirectly by dbuf_rele() while relying on the dnode handle to
1246 * prevent the dnode from moving, since releasing the last hold could
1247 * result in the dnode's parent dbuf evicting its dnode handles. For
1248 * that reason anyone calling dnode_rele() or dbuf_rele() without some
1249 * other direct or indirect hold on the dnode must first drop the dnode
1250 * handle.
1251 */
1252 ASSERT(refs > 0 || dnh->dnh_zrlock.zr_owner != curthread);
1253
1254 /* NOTE: the DNODE_DNODE does not have a dn_dbuf */
1255 if (refs == 0 && db != NULL) {
1256 /*
1257 * Another thread could add a hold to the dnode handle in
1258 * dnode_hold_impl() while holding the parent dbuf. Since the
1259 * hold on the parent dbuf prevents the handle from being
1260 * destroyed, the hold on the handle is OK. We can't yet assert
1261 * that the handle has zero references, but that will be
1262 * asserted anyway when the handle gets destroyed.
1263 */
1264 dbuf_rele(db, dnh);
1265 }
1266 }
1267
1268 void
dnode_setdirty(dnode_t * dn,dmu_tx_t * tx)1269 dnode_setdirty(dnode_t *dn, dmu_tx_t *tx)
1270 {
1271 objset_t *os = dn->dn_objset;
1272 uint64_t txg = tx->tx_txg;
1273
1274 if (DMU_OBJECT_IS_SPECIAL(dn->dn_object)) {
1275 dsl_dataset_dirty(os->os_dsl_dataset, tx);
1276 return;
1277 }
1278
1279 DNODE_VERIFY(dn);
1280
1281 #ifdef ZFS_DEBUG
1282 mutex_enter(&dn->dn_mtx);
1283 ASSERT(dn->dn_phys->dn_type || dn->dn_allocated_txg);
1284 ASSERT(dn->dn_free_txg == 0 || dn->dn_free_txg >= txg);
1285 mutex_exit(&dn->dn_mtx);
1286 #endif
1287
1288 /*
1289 * Determine old uid/gid when necessary
1290 */
1291 dmu_objset_userquota_get_ids(dn, B_TRUE, tx);
1292
1293 mutex_enter(&os->os_lock);
1294
1295 /*
1296 * If we are already marked dirty, we're done.
1297 */
1298 if (list_link_active(&dn->dn_dirty_link[txg & TXG_MASK])) {
1299 mutex_exit(&os->os_lock);
1300 return;
1301 }
1302
1303 ASSERT(!refcount_is_zero(&dn->dn_holds) ||
1304 !avl_is_empty(&dn->dn_dbufs));
1305 ASSERT(dn->dn_datablksz != 0);
1306 ASSERT0(dn->dn_next_bonuslen[txg&TXG_MASK]);
1307 ASSERT0(dn->dn_next_blksz[txg&TXG_MASK]);
1308 ASSERT0(dn->dn_next_bonustype[txg&TXG_MASK]);
1309
1310 dprintf_ds(os->os_dsl_dataset, "obj=%llu txg=%llu\n",
1311 dn->dn_object, txg);
1312
1313 if (dn->dn_free_txg > 0 && dn->dn_free_txg <= txg) {
1314 list_insert_tail(&os->os_free_dnodes[txg&TXG_MASK], dn);
1315 } else {
1316 list_insert_tail(&os->os_dirty_dnodes[txg&TXG_MASK], dn);
1317 }
1318
1319 mutex_exit(&os->os_lock);
1320
1321 /*
1322 * The dnode maintains a hold on its containing dbuf as
1323 * long as there are holds on it. Each instantiated child
1324 * dbuf maintains a hold on the dnode. When the last child
1325 * drops its hold, the dnode will drop its hold on the
1326 * containing dbuf. We add a "dirty hold" here so that the
1327 * dnode will hang around after we finish processing its
1328 * children.
1329 */
1330 VERIFY(dnode_add_ref(dn, (void *)(uintptr_t)tx->tx_txg));
1331
1332 (void) dbuf_dirty(dn->dn_dbuf, tx);
1333
1334 dsl_dataset_dirty(os->os_dsl_dataset, tx);
1335 }
1336
1337 void
dnode_free(dnode_t * dn,dmu_tx_t * tx)1338 dnode_free(dnode_t *dn, dmu_tx_t *tx)
1339 {
1340 int txgoff = tx->tx_txg & TXG_MASK;
1341
1342 dprintf("dn=%p txg=%llu\n", dn, tx->tx_txg);
1343
1344 /* we should be the only holder... hopefully */
1345 /* ASSERT3U(refcount_count(&dn->dn_holds), ==, 1); */
1346
1347 mutex_enter(&dn->dn_mtx);
1348 if (dn->dn_type == DMU_OT_NONE || dn->dn_free_txg) {
1349 mutex_exit(&dn->dn_mtx);
1350 return;
1351 }
1352 dn->dn_free_txg = tx->tx_txg;
1353 mutex_exit(&dn->dn_mtx);
1354
1355 /*
1356 * If the dnode is already dirty, it needs to be moved from
1357 * the dirty list to the free list.
1358 */
1359 mutex_enter(&dn->dn_objset->os_lock);
1360 if (list_link_active(&dn->dn_dirty_link[txgoff])) {
1361 list_remove(&dn->dn_objset->os_dirty_dnodes[txgoff], dn);
1362 list_insert_tail(&dn->dn_objset->os_free_dnodes[txgoff], dn);
1363 mutex_exit(&dn->dn_objset->os_lock);
1364 } else {
1365 mutex_exit(&dn->dn_objset->os_lock);
1366 dnode_setdirty(dn, tx);
1367 }
1368 }
1369
1370 /*
1371 * Try to change the block size for the indicated dnode. This can only
1372 * succeed if there are no blocks allocated or dirty beyond first block
1373 */
1374 int
dnode_set_blksz(dnode_t * dn,uint64_t size,int ibs,dmu_tx_t * tx)1375 dnode_set_blksz(dnode_t *dn, uint64_t size, int ibs, dmu_tx_t *tx)
1376 {
1377 dmu_buf_impl_t *db;
1378 int err;
1379
1380 ASSERT3U(size, <=, spa_maxblocksize(dmu_objset_spa(dn->dn_objset)));
1381 if (size == 0)
1382 size = SPA_MINBLOCKSIZE;
1383 else
1384 size = P2ROUNDUP(size, SPA_MINBLOCKSIZE);
1385
1386 if (ibs == dn->dn_indblkshift)
1387 ibs = 0;
1388
1389 if (size >> SPA_MINBLOCKSHIFT == dn->dn_datablkszsec && ibs == 0)
1390 return (0);
1391
1392 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
1393
1394 /* Check for any allocated blocks beyond the first */
1395 if (dn->dn_maxblkid != 0)
1396 goto fail;
1397
1398 mutex_enter(&dn->dn_dbufs_mtx);
1399 for (db = avl_first(&dn->dn_dbufs); db != NULL;
1400 db = AVL_NEXT(&dn->dn_dbufs, db)) {
1401 if (db->db_blkid != 0 && db->db_blkid != DMU_BONUS_BLKID &&
1402 db->db_blkid != DMU_SPILL_BLKID) {
1403 mutex_exit(&dn->dn_dbufs_mtx);
1404 goto fail;
1405 }
1406 }
1407 mutex_exit(&dn->dn_dbufs_mtx);
1408
1409 if (ibs && dn->dn_nlevels != 1)
1410 goto fail;
1411
1412 /* resize the old block */
1413 err = dbuf_hold_impl(dn, 0, 0, TRUE, FALSE, FTAG, &db);
1414 if (err == 0)
1415 dbuf_new_size(db, size, tx);
1416 else if (err != ENOENT)
1417 goto fail;
1418
1419 dnode_setdblksz(dn, size);
1420 dnode_setdirty(dn, tx);
1421 dn->dn_next_blksz[tx->tx_txg&TXG_MASK] = size;
1422 if (ibs) {
1423 dn->dn_indblkshift = ibs;
1424 dn->dn_next_indblkshift[tx->tx_txg&TXG_MASK] = ibs;
1425 }
1426 /* rele after we have fixed the blocksize in the dnode */
1427 if (db)
1428 dbuf_rele(db, FTAG);
1429
1430 rw_exit(&dn->dn_struct_rwlock);
1431 return (0);
1432
1433 fail:
1434 rw_exit(&dn->dn_struct_rwlock);
1435 return (SET_ERROR(ENOTSUP));
1436 }
1437
1438 /* read-holding callers must not rely on the lock being continuously held */
1439 void
dnode_new_blkid(dnode_t * dn,uint64_t blkid,dmu_tx_t * tx,boolean_t have_read)1440 dnode_new_blkid(dnode_t *dn, uint64_t blkid, dmu_tx_t *tx, boolean_t have_read)
1441 {
1442 uint64_t txgoff = tx->tx_txg & TXG_MASK;
1443 int epbs, new_nlevels;
1444 uint64_t sz;
1445
1446 ASSERT(blkid != DMU_BONUS_BLKID);
1447
1448 ASSERT(have_read ?
1449 RW_READ_HELD(&dn->dn_struct_rwlock) :
1450 RW_WRITE_HELD(&dn->dn_struct_rwlock));
1451
1452 /*
1453 * if we have a read-lock, check to see if we need to do any work
1454 * before upgrading to a write-lock.
1455 */
1456 if (have_read) {
1457 if (blkid <= dn->dn_maxblkid)
1458 return;
1459
1460 if (!rw_tryupgrade(&dn->dn_struct_rwlock)) {
1461 rw_exit(&dn->dn_struct_rwlock);
1462 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
1463 }
1464 }
1465
1466 if (blkid <= dn->dn_maxblkid)
1467 goto out;
1468
1469 dn->dn_maxblkid = blkid;
1470
1471 /*
1472 * Compute the number of levels necessary to support the new maxblkid.
1473 */
1474 new_nlevels = 1;
1475 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT;
1476 for (sz = dn->dn_nblkptr;
1477 sz <= blkid && sz >= dn->dn_nblkptr; sz <<= epbs)
1478 new_nlevels++;
1479
1480 if (new_nlevels > dn->dn_nlevels) {
1481 int old_nlevels = dn->dn_nlevels;
1482 dmu_buf_impl_t *db;
1483 list_t *list;
1484 dbuf_dirty_record_t *new, *dr, *dr_next;
1485
1486 dn->dn_nlevels = new_nlevels;
1487
1488 ASSERT3U(new_nlevels, >, dn->dn_next_nlevels[txgoff]);
1489 dn->dn_next_nlevels[txgoff] = new_nlevels;
1490
1491 /* dirty the left indirects */
1492 db = dbuf_hold_level(dn, old_nlevels, 0, FTAG);
1493 ASSERT(db != NULL);
1494 new = dbuf_dirty(db, tx);
1495 dbuf_rele(db, FTAG);
1496
1497 /* transfer the dirty records to the new indirect */
1498 mutex_enter(&dn->dn_mtx);
1499 mutex_enter(&new->dt.di.dr_mtx);
1500 list = &dn->dn_dirty_records[txgoff];
1501 for (dr = list_head(list); dr; dr = dr_next) {
1502 dr_next = list_next(&dn->dn_dirty_records[txgoff], dr);
1503 if (dr->dr_dbuf->db_level != new_nlevels-1 &&
1504 dr->dr_dbuf->db_blkid != DMU_BONUS_BLKID &&
1505 dr->dr_dbuf->db_blkid != DMU_SPILL_BLKID) {
1506 ASSERT(dr->dr_dbuf->db_level == old_nlevels-1);
1507 list_remove(&dn->dn_dirty_records[txgoff], dr);
1508 list_insert_tail(&new->dt.di.dr_children, dr);
1509 dr->dr_parent = new;
1510 }
1511 }
1512 mutex_exit(&new->dt.di.dr_mtx);
1513 mutex_exit(&dn->dn_mtx);
1514 }
1515
1516 out:
1517 if (have_read)
1518 rw_downgrade(&dn->dn_struct_rwlock);
1519 }
1520
1521 static void
dnode_dirty_l1(dnode_t * dn,uint64_t l1blkid,dmu_tx_t * tx)1522 dnode_dirty_l1(dnode_t *dn, uint64_t l1blkid, dmu_tx_t *tx)
1523 {
1524 dmu_buf_impl_t *db = dbuf_hold_level(dn, 1, l1blkid, FTAG);
1525 if (db != NULL) {
1526 dmu_buf_will_dirty(&db->db, tx);
1527 dbuf_rele(db, FTAG);
1528 }
1529 }
1530
1531 void
dnode_free_range(dnode_t * dn,uint64_t off,uint64_t len,dmu_tx_t * tx)1532 dnode_free_range(dnode_t *dn, uint64_t off, uint64_t len, dmu_tx_t *tx)
1533 {
1534 dmu_buf_impl_t *db;
1535 uint64_t blkoff, blkid, nblks;
1536 int blksz, blkshift, head, tail;
1537 int trunc = FALSE;
1538 int epbs;
1539
1540 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
1541 blksz = dn->dn_datablksz;
1542 blkshift = dn->dn_datablkshift;
1543 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT;
1544
1545 if (len == DMU_OBJECT_END) {
1546 len = UINT64_MAX - off;
1547 trunc = TRUE;
1548 }
1549
1550 /*
1551 * First, block align the region to free:
1552 */
1553 if (ISP2(blksz)) {
1554 head = P2NPHASE(off, blksz);
1555 blkoff = P2PHASE(off, blksz);
1556 if ((off >> blkshift) > dn->dn_maxblkid)
1557 goto out;
1558 } else {
1559 ASSERT(dn->dn_maxblkid == 0);
1560 if (off == 0 && len >= blksz) {
1561 /*
1562 * Freeing the whole block; fast-track this request.
1563 * Note that we won't dirty any indirect blocks,
1564 * which is fine because we will be freeing the entire
1565 * file and thus all indirect blocks will be freed
1566 * by free_children().
1567 */
1568 blkid = 0;
1569 nblks = 1;
1570 goto done;
1571 } else if (off >= blksz) {
1572 /* Freeing past end-of-data */
1573 goto out;
1574 } else {
1575 /* Freeing part of the block. */
1576 head = blksz - off;
1577 ASSERT3U(head, >, 0);
1578 }
1579 blkoff = off;
1580 }
1581 /* zero out any partial block data at the start of the range */
1582 if (head) {
1583 ASSERT3U(blkoff + head, ==, blksz);
1584 if (len < head)
1585 head = len;
1586 if (dbuf_hold_impl(dn, 0, dbuf_whichblock(dn, 0, off),
1587 TRUE, FALSE, FTAG, &db) == 0) {
1588 caddr_t data;
1589
1590 /* don't dirty if it isn't on disk and isn't dirty */
1591 if (db->db_last_dirty ||
1592 (db->db_blkptr && !BP_IS_HOLE(db->db_blkptr))) {
1593 rw_exit(&dn->dn_struct_rwlock);
1594 dmu_buf_will_dirty(&db->db, tx);
1595 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
1596 data = db->db.db_data;
1597 bzero(data + blkoff, head);
1598 }
1599 dbuf_rele(db, FTAG);
1600 }
1601 off += head;
1602 len -= head;
1603 }
1604
1605 /* If the range was less than one block, we're done */
1606 if (len == 0)
1607 goto out;
1608
1609 /* If the remaining range is past end of file, we're done */
1610 if ((off >> blkshift) > dn->dn_maxblkid)
1611 goto out;
1612
1613 ASSERT(ISP2(blksz));
1614 if (trunc)
1615 tail = 0;
1616 else
1617 tail = P2PHASE(len, blksz);
1618
1619 ASSERT0(P2PHASE(off, blksz));
1620 /* zero out any partial block data at the end of the range */
1621 if (tail) {
1622 if (len < tail)
1623 tail = len;
1624 if (dbuf_hold_impl(dn, 0, dbuf_whichblock(dn, 0, off+len),
1625 TRUE, FALSE, FTAG, &db) == 0) {
1626 /* don't dirty if not on disk and not dirty */
1627 if (db->db_last_dirty ||
1628 (db->db_blkptr && !BP_IS_HOLE(db->db_blkptr))) {
1629 rw_exit(&dn->dn_struct_rwlock);
1630 dmu_buf_will_dirty(&db->db, tx);
1631 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
1632 bzero(db->db.db_data, tail);
1633 }
1634 dbuf_rele(db, FTAG);
1635 }
1636 len -= tail;
1637 }
1638
1639 /* If the range did not include a full block, we are done */
1640 if (len == 0)
1641 goto out;
1642
1643 ASSERT(IS_P2ALIGNED(off, blksz));
1644 ASSERT(trunc || IS_P2ALIGNED(len, blksz));
1645 blkid = off >> blkshift;
1646 nblks = len >> blkshift;
1647 if (trunc)
1648 nblks += 1;
1649
1650 /*
1651 * Dirty all the indirect blocks in this range. Note that only
1652 * the first and last indirect blocks can actually be written
1653 * (if they were partially freed) -- they must be dirtied, even if
1654 * they do not exist on disk yet. The interior blocks will
1655 * be freed by free_children(), so they will not actually be written.
1656 * Even though these interior blocks will not be written, we
1657 * dirty them for two reasons:
1658 *
1659 * - It ensures that the indirect blocks remain in memory until
1660 * syncing context. (They have already been prefetched by
1661 * dmu_tx_hold_free(), so we don't have to worry about reading
1662 * them serially here.)
1663 *
1664 * - The dirty space accounting will put pressure on the txg sync
1665 * mechanism to begin syncing, and to delay transactions if there
1666 * is a large amount of freeing. Even though these indirect
1667 * blocks will not be written, we could need to write the same
1668 * amount of space if we copy the freed BPs into deadlists.
1669 */
1670 if (dn->dn_nlevels > 1) {
1671 uint64_t first, last;
1672
1673 first = blkid >> epbs;
1674 dnode_dirty_l1(dn, first, tx);
1675 if (trunc)
1676 last = dn->dn_maxblkid >> epbs;
1677 else
1678 last = (blkid + nblks - 1) >> epbs;
1679 if (last != first)
1680 dnode_dirty_l1(dn, last, tx);
1681
1682 int shift = dn->dn_datablkshift + dn->dn_indblkshift -
1683 SPA_BLKPTRSHIFT;
1684 for (uint64_t i = first + 1; i < last; i++) {
1685 /*
1686 * Set i to the blockid of the next non-hole
1687 * level-1 indirect block at or after i. Note
1688 * that dnode_next_offset() operates in terms of
1689 * level-0-equivalent bytes.
1690 */
1691 uint64_t ibyte = i << shift;
1692 int err = dnode_next_offset(dn, DNODE_FIND_HAVELOCK,
1693 &ibyte, 2, 1, 0);
1694 i = ibyte >> shift;
1695 if (i >= last)
1696 break;
1697
1698 /*
1699 * Normally we should not see an error, either
1700 * from dnode_next_offset() or dbuf_hold_level()
1701 * (except for ESRCH from dnode_next_offset).
1702 * If there is an i/o error, then when we read
1703 * this block in syncing context, it will use
1704 * ZIO_FLAG_MUSTSUCCEED, and thus hang/panic according
1705 * to the "failmode" property. dnode_next_offset()
1706 * doesn't have a flag to indicate MUSTSUCCEED.
1707 */
1708 if (err != 0)
1709 break;
1710
1711 dnode_dirty_l1(dn, i, tx);
1712 }
1713 }
1714
1715 done:
1716 /*
1717 * Add this range to the dnode range list.
1718 * We will finish up this free operation in the syncing phase.
1719 */
1720 mutex_enter(&dn->dn_mtx);
1721 int txgoff = tx->tx_txg & TXG_MASK;
1722 if (dn->dn_free_ranges[txgoff] == NULL) {
1723 dn->dn_free_ranges[txgoff] =
1724 range_tree_create(NULL, NULL, &dn->dn_mtx);
1725 }
1726 range_tree_clear(dn->dn_free_ranges[txgoff], blkid, nblks);
1727 range_tree_add(dn->dn_free_ranges[txgoff], blkid, nblks);
1728 dprintf_dnode(dn, "blkid=%llu nblks=%llu txg=%llu\n",
1729 blkid, nblks, tx->tx_txg);
1730 mutex_exit(&dn->dn_mtx);
1731
1732 dbuf_free_range(dn, blkid, blkid + nblks - 1, tx);
1733 dnode_setdirty(dn, tx);
1734 out:
1735
1736 rw_exit(&dn->dn_struct_rwlock);
1737 }
1738
1739 static boolean_t
dnode_spill_freed(dnode_t * dn)1740 dnode_spill_freed(dnode_t *dn)
1741 {
1742 int i;
1743
1744 mutex_enter(&dn->dn_mtx);
1745 for (i = 0; i < TXG_SIZE; i++) {
1746 if (dn->dn_rm_spillblk[i] == DN_KILL_SPILLBLK)
1747 break;
1748 }
1749 mutex_exit(&dn->dn_mtx);
1750 return (i < TXG_SIZE);
1751 }
1752
1753 /* return TRUE if this blkid was freed in a recent txg, or FALSE if it wasn't */
1754 uint64_t
dnode_block_freed(dnode_t * dn,uint64_t blkid)1755 dnode_block_freed(dnode_t *dn, uint64_t blkid)
1756 {
1757 void *dp = spa_get_dsl(dn->dn_objset->os_spa);
1758 int i;
1759
1760 if (blkid == DMU_BONUS_BLKID)
1761 return (FALSE);
1762
1763 /*
1764 * If we're in the process of opening the pool, dp will not be
1765 * set yet, but there shouldn't be anything dirty.
1766 */
1767 if (dp == NULL)
1768 return (FALSE);
1769
1770 if (dn->dn_free_txg)
1771 return (TRUE);
1772
1773 if (blkid == DMU_SPILL_BLKID)
1774 return (dnode_spill_freed(dn));
1775
1776 mutex_enter(&dn->dn_mtx);
1777 for (i = 0; i < TXG_SIZE; i++) {
1778 if (dn->dn_free_ranges[i] != NULL &&
1779 range_tree_contains(dn->dn_free_ranges[i], blkid, 1))
1780 break;
1781 }
1782 mutex_exit(&dn->dn_mtx);
1783 return (i < TXG_SIZE);
1784 }
1785
1786 /* call from syncing context when we actually write/free space for this dnode */
1787 void
dnode_diduse_space(dnode_t * dn,int64_t delta)1788 dnode_diduse_space(dnode_t *dn, int64_t delta)
1789 {
1790 uint64_t space;
1791 dprintf_dnode(dn, "dn=%p dnp=%p used=%llu delta=%lld\n",
1792 dn, dn->dn_phys,
1793 (u_longlong_t)dn->dn_phys->dn_used,
1794 (longlong_t)delta);
1795
1796 mutex_enter(&dn->dn_mtx);
1797 space = DN_USED_BYTES(dn->dn_phys);
1798 if (delta > 0) {
1799 ASSERT3U(space + delta, >=, space); /* no overflow */
1800 } else {
1801 ASSERT3U(space, >=, -delta); /* no underflow */
1802 }
1803 space += delta;
1804 if (spa_version(dn->dn_objset->os_spa) < SPA_VERSION_DNODE_BYTES) {
1805 ASSERT((dn->dn_phys->dn_flags & DNODE_FLAG_USED_BYTES) == 0);
1806 ASSERT0(P2PHASE(space, 1<<DEV_BSHIFT));
1807 dn->dn_phys->dn_used = space >> DEV_BSHIFT;
1808 } else {
1809 dn->dn_phys->dn_used = space;
1810 dn->dn_phys->dn_flags |= DNODE_FLAG_USED_BYTES;
1811 }
1812 mutex_exit(&dn->dn_mtx);
1813 }
1814
1815 /*
1816 * Call when we think we're going to write/free space in open context to track
1817 * the amount of memory in use by the currently open txg.
1818 */
1819 void
dnode_willuse_space(dnode_t * dn,int64_t space,dmu_tx_t * tx)1820 dnode_willuse_space(dnode_t *dn, int64_t space, dmu_tx_t *tx)
1821 {
1822 objset_t *os = dn->dn_objset;
1823 dsl_dataset_t *ds = os->os_dsl_dataset;
1824 int64_t aspace = spa_get_asize(os->os_spa, space);
1825
1826 if (ds != NULL) {
1827 dsl_dir_willuse_space(ds->ds_dir, aspace, tx);
1828 dsl_pool_dirty_space(dmu_tx_pool(tx), space, tx);
1829 }
1830
1831 dmu_tx_willuse_space(tx, aspace);
1832 }
1833
1834 /*
1835 * Scans a block at the indicated "level" looking for a hole or data,
1836 * depending on 'flags'.
1837 *
1838 * If level > 0, then we are scanning an indirect block looking at its
1839 * pointers. If level == 0, then we are looking at a block of dnodes.
1840 *
1841 * If we don't find what we are looking for in the block, we return ESRCH.
1842 * Otherwise, return with *offset pointing to the beginning (if searching
1843 * forwards) or end (if searching backwards) of the range covered by the
1844 * block pointer we matched on (or dnode).
1845 *
1846 * The basic search algorithm used below by dnode_next_offset() is to
1847 * use this function to search up the block tree (widen the search) until
1848 * we find something (i.e., we don't return ESRCH) and then search back
1849 * down the tree (narrow the search) until we reach our original search
1850 * level.
1851 */
1852 static int
dnode_next_offset_level(dnode_t * dn,int flags,uint64_t * offset,int lvl,uint64_t blkfill,uint64_t txg)1853 dnode_next_offset_level(dnode_t *dn, int flags, uint64_t *offset,
1854 int lvl, uint64_t blkfill, uint64_t txg)
1855 {
1856 dmu_buf_impl_t *db = NULL;
1857 void *data = NULL;
1858 uint64_t epbs = dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT;
1859 uint64_t epb = 1ULL << epbs;
1860 uint64_t minfill, maxfill;
1861 boolean_t hole;
1862 int i, inc, error, span;
1863
1864 dprintf("probing object %llu offset %llx level %d of %u\n",
1865 dn->dn_object, *offset, lvl, dn->dn_phys->dn_nlevels);
1866
1867 hole = ((flags & DNODE_FIND_HOLE) != 0);
1868 inc = (flags & DNODE_FIND_BACKWARDS) ? -1 : 1;
1869 ASSERT(txg == 0 || !hole);
1870
1871 if (lvl == dn->dn_phys->dn_nlevels) {
1872 error = 0;
1873 epb = dn->dn_phys->dn_nblkptr;
1874 data = dn->dn_phys->dn_blkptr;
1875 } else {
1876 uint64_t blkid = dbuf_whichblock(dn, lvl, *offset);
1877 error = dbuf_hold_impl(dn, lvl, blkid, TRUE, FALSE, FTAG, &db);
1878 if (error) {
1879 if (error != ENOENT)
1880 return (error);
1881 if (hole)
1882 return (0);
1883 /*
1884 * This can only happen when we are searching up
1885 * the block tree for data. We don't really need to
1886 * adjust the offset, as we will just end up looking
1887 * at the pointer to this block in its parent, and its
1888 * going to be unallocated, so we will skip over it.
1889 */
1890 return (SET_ERROR(ESRCH));
1891 }
1892 error = dbuf_read(db, NULL, DB_RF_CANFAIL | DB_RF_HAVESTRUCT);
1893 if (error) {
1894 dbuf_rele(db, FTAG);
1895 return (error);
1896 }
1897 data = db->db.db_data;
1898 }
1899
1900
1901 if (db != NULL && txg != 0 && (db->db_blkptr == NULL ||
1902 db->db_blkptr->blk_birth <= txg ||
1903 BP_IS_HOLE(db->db_blkptr))) {
1904 /*
1905 * This can only happen when we are searching up the tree
1906 * and these conditions mean that we need to keep climbing.
1907 */
1908 error = SET_ERROR(ESRCH);
1909 } else if (lvl == 0) {
1910 dnode_phys_t *dnp = data;
1911 span = DNODE_SHIFT;
1912 ASSERT(dn->dn_type == DMU_OT_DNODE);
1913
1914 for (i = (*offset >> span) & (blkfill - 1);
1915 i >= 0 && i < blkfill; i += inc) {
1916 if ((dnp[i].dn_type == DMU_OT_NONE) == hole)
1917 break;
1918 *offset += (1ULL << span) * inc;
1919 }
1920 if (i < 0 || i == blkfill)
1921 error = SET_ERROR(ESRCH);
1922 } else {
1923 blkptr_t *bp = data;
1924 uint64_t start = *offset;
1925 span = (lvl - 1) * epbs + dn->dn_datablkshift;
1926 minfill = 0;
1927 maxfill = blkfill << ((lvl - 1) * epbs);
1928
1929 if (hole)
1930 maxfill--;
1931 else
1932 minfill++;
1933
1934 *offset = *offset >> span;
1935 for (i = BF64_GET(*offset, 0, epbs);
1936 i >= 0 && i < epb; i += inc) {
1937 if (BP_GET_FILL(&bp[i]) >= minfill &&
1938 BP_GET_FILL(&bp[i]) <= maxfill &&
1939 (hole || bp[i].blk_birth > txg))
1940 break;
1941 if (inc > 0 || *offset > 0)
1942 *offset += inc;
1943 }
1944 *offset = *offset << span;
1945 if (inc < 0) {
1946 /* traversing backwards; position offset at the end */
1947 ASSERT3U(*offset, <=, start);
1948 *offset = MIN(*offset + (1ULL << span) - 1, start);
1949 } else if (*offset < start) {
1950 *offset = start;
1951 }
1952 if (i < 0 || i >= epb)
1953 error = SET_ERROR(ESRCH);
1954 }
1955
1956 if (db)
1957 dbuf_rele(db, FTAG);
1958
1959 return (error);
1960 }
1961
1962 /*
1963 * Find the next hole, data, or sparse region at or after *offset.
1964 * The value 'blkfill' tells us how many items we expect to find
1965 * in an L0 data block; this value is 1 for normal objects,
1966 * DNODES_PER_BLOCK for the meta dnode, and some fraction of
1967 * DNODES_PER_BLOCK when searching for sparse regions thereof.
1968 *
1969 * Examples:
1970 *
1971 * dnode_next_offset(dn, flags, offset, 1, 1, 0);
1972 * Finds the next/previous hole/data in a file.
1973 * Used in dmu_offset_next().
1974 *
1975 * dnode_next_offset(mdn, flags, offset, 0, DNODES_PER_BLOCK, txg);
1976 * Finds the next free/allocated dnode an objset's meta-dnode.
1977 * Only finds objects that have new contents since txg (ie.
1978 * bonus buffer changes and content removal are ignored).
1979 * Used in dmu_object_next().
1980 *
1981 * dnode_next_offset(mdn, DNODE_FIND_HOLE, offset, 2, DNODES_PER_BLOCK >> 2, 0);
1982 * Finds the next L2 meta-dnode bp that's at most 1/4 full.
1983 * Used in dmu_object_alloc().
1984 */
1985 int
dnode_next_offset(dnode_t * dn,int flags,uint64_t * offset,int minlvl,uint64_t blkfill,uint64_t txg)1986 dnode_next_offset(dnode_t *dn, int flags, uint64_t *offset,
1987 int minlvl, uint64_t blkfill, uint64_t txg)
1988 {
1989 uint64_t initial_offset = *offset;
1990 int lvl, maxlvl;
1991 int error = 0;
1992
1993 if (!(flags & DNODE_FIND_HAVELOCK))
1994 rw_enter(&dn->dn_struct_rwlock, RW_READER);
1995
1996 if (dn->dn_phys->dn_nlevels == 0) {
1997 error = SET_ERROR(ESRCH);
1998 goto out;
1999 }
2000
2001 if (dn->dn_datablkshift == 0) {
2002 if (*offset < dn->dn_datablksz) {
2003 if (flags & DNODE_FIND_HOLE)
2004 *offset = dn->dn_datablksz;
2005 } else {
2006 error = SET_ERROR(ESRCH);
2007 }
2008 goto out;
2009 }
2010
2011 maxlvl = dn->dn_phys->dn_nlevels;
2012
2013 for (lvl = minlvl; lvl <= maxlvl; lvl++) {
2014 error = dnode_next_offset_level(dn,
2015 flags, offset, lvl, blkfill, txg);
2016 if (error != ESRCH)
2017 break;
2018 }
2019
2020 while (error == 0 && --lvl >= minlvl) {
2021 error = dnode_next_offset_level(dn,
2022 flags, offset, lvl, blkfill, txg);
2023 }
2024
2025 /*
2026 * There's always a "virtual hole" at the end of the object, even
2027 * if all BP's which physically exist are non-holes.
2028 */
2029 if ((flags & DNODE_FIND_HOLE) && error == ESRCH && txg == 0 &&
2030 minlvl == 1 && blkfill == 1 && !(flags & DNODE_FIND_BACKWARDS)) {
2031 error = 0;
2032 }
2033
2034 if (error == 0 && (flags & DNODE_FIND_BACKWARDS ?
2035 initial_offset < *offset : initial_offset > *offset))
2036 error = SET_ERROR(ESRCH);
2037 out:
2038 if (!(flags & DNODE_FIND_HAVELOCK))
2039 rw_exit(&dn->dn_struct_rwlock);
2040
2041 return (error);
2042 }
2043