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, 2015 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 static kmem_cbrc_t dnode_move(void *, void *, size_t, void *);
63
64 static int
dbuf_compare(const void * x1,const void * x2)65 dbuf_compare(const void *x1, const void *x2)
66 {
67 const dmu_buf_impl_t *d1 = x1;
68 const dmu_buf_impl_t *d2 = x2;
69
70 if (d1->db_level < d2->db_level) {
71 return (-1);
72 }
73 if (d1->db_level > d2->db_level) {
74 return (1);
75 }
76
77 if (d1->db_blkid < d2->db_blkid) {
78 return (-1);
79 }
80 if (d1->db_blkid > d2->db_blkid) {
81 return (1);
82 }
83
84 if (d1->db_state == DB_SEARCH) {
85 ASSERT3S(d2->db_state, !=, DB_SEARCH);
86 return (-1);
87 } else if (d2->db_state == DB_SEARCH) {
88 ASSERT3S(d1->db_state, !=, DB_SEARCH);
89 return (1);
90 }
91
92 if ((uintptr_t)d1 < (uintptr_t)d2) {
93 return (-1);
94 }
95 if ((uintptr_t)d1 > (uintptr_t)d2) {
96 return (1);
97 }
98 return (0);
99 }
100
101 /* ARGSUSED */
102 static int
dnode_cons(void * arg,void * unused,int kmflag)103 dnode_cons(void *arg, void *unused, int kmflag)
104 {
105 dnode_t *dn = arg;
106 int i;
107
108 rw_init(&dn->dn_struct_rwlock, NULL, RW_DEFAULT, NULL);
109 mutex_init(&dn->dn_mtx, NULL, MUTEX_DEFAULT, NULL);
110 mutex_init(&dn->dn_dbufs_mtx, NULL, MUTEX_DEFAULT, NULL);
111 cv_init(&dn->dn_notxholds, NULL, CV_DEFAULT, NULL);
112
113 /*
114 * Every dbuf has a reference, and dropping a tracked reference is
115 * O(number of references), so don't track dn_holds.
116 */
117 refcount_create_untracked(&dn->dn_holds);
118 refcount_create(&dn->dn_tx_holds);
119 list_link_init(&dn->dn_link);
120
121 bzero(&dn->dn_next_nblkptr[0], sizeof (dn->dn_next_nblkptr));
122 bzero(&dn->dn_next_nlevels[0], sizeof (dn->dn_next_nlevels));
123 bzero(&dn->dn_next_indblkshift[0], sizeof (dn->dn_next_indblkshift));
124 bzero(&dn->dn_next_bonustype[0], sizeof (dn->dn_next_bonustype));
125 bzero(&dn->dn_rm_spillblk[0], sizeof (dn->dn_rm_spillblk));
126 bzero(&dn->dn_next_bonuslen[0], sizeof (dn->dn_next_bonuslen));
127 bzero(&dn->dn_next_blksz[0], sizeof (dn->dn_next_blksz));
128
129 for (i = 0; i < TXG_SIZE; i++) {
130 list_link_init(&dn->dn_dirty_link[i]);
131 dn->dn_free_ranges[i] = NULL;
132 list_create(&dn->dn_dirty_records[i],
133 sizeof (dbuf_dirty_record_t),
134 offsetof(dbuf_dirty_record_t, dr_dirty_node));
135 }
136
137 dn->dn_allocated_txg = 0;
138 dn->dn_free_txg = 0;
139 dn->dn_assigned_txg = 0;
140 dn->dn_dirtyctx = 0;
141 dn->dn_dirtyctx_firstset = NULL;
142 dn->dn_bonus = NULL;
143 dn->dn_have_spill = B_FALSE;
144 dn->dn_zio = NULL;
145 dn->dn_oldused = 0;
146 dn->dn_oldflags = 0;
147 dn->dn_olduid = 0;
148 dn->dn_oldgid = 0;
149 dn->dn_newuid = 0;
150 dn->dn_newgid = 0;
151 dn->dn_id_flags = 0;
152
153 dn->dn_dbufs_count = 0;
154 dn->dn_unlisted_l0_blkid = 0;
155 avl_create(&dn->dn_dbufs, dbuf_compare, sizeof (dmu_buf_impl_t),
156 offsetof(dmu_buf_impl_t, db_link));
157
158 dn->dn_moved = 0;
159 return (0);
160 }
161
162 /* ARGSUSED */
163 static void
dnode_dest(void * arg,void * unused)164 dnode_dest(void *arg, void *unused)
165 {
166 int i;
167 dnode_t *dn = arg;
168
169 rw_destroy(&dn->dn_struct_rwlock);
170 mutex_destroy(&dn->dn_mtx);
171 mutex_destroy(&dn->dn_dbufs_mtx);
172 cv_destroy(&dn->dn_notxholds);
173 refcount_destroy(&dn->dn_holds);
174 refcount_destroy(&dn->dn_tx_holds);
175 ASSERT(!list_link_active(&dn->dn_link));
176
177 for (i = 0; i < TXG_SIZE; i++) {
178 ASSERT(!list_link_active(&dn->dn_dirty_link[i]));
179 ASSERT3P(dn->dn_free_ranges[i], ==, NULL);
180 list_destroy(&dn->dn_dirty_records[i]);
181 ASSERT0(dn->dn_next_nblkptr[i]);
182 ASSERT0(dn->dn_next_nlevels[i]);
183 ASSERT0(dn->dn_next_indblkshift[i]);
184 ASSERT0(dn->dn_next_bonustype[i]);
185 ASSERT0(dn->dn_rm_spillblk[i]);
186 ASSERT0(dn->dn_next_bonuslen[i]);
187 ASSERT0(dn->dn_next_blksz[i]);
188 }
189
190 ASSERT0(dn->dn_allocated_txg);
191 ASSERT0(dn->dn_free_txg);
192 ASSERT0(dn->dn_assigned_txg);
193 ASSERT0(dn->dn_dirtyctx);
194 ASSERT3P(dn->dn_dirtyctx_firstset, ==, NULL);
195 ASSERT3P(dn->dn_bonus, ==, NULL);
196 ASSERT(!dn->dn_have_spill);
197 ASSERT3P(dn->dn_zio, ==, NULL);
198 ASSERT0(dn->dn_oldused);
199 ASSERT0(dn->dn_oldflags);
200 ASSERT0(dn->dn_olduid);
201 ASSERT0(dn->dn_oldgid);
202 ASSERT0(dn->dn_newuid);
203 ASSERT0(dn->dn_newgid);
204 ASSERT0(dn->dn_id_flags);
205
206 ASSERT0(dn->dn_dbufs_count);
207 ASSERT0(dn->dn_unlisted_l0_blkid);
208 avl_destroy(&dn->dn_dbufs);
209 }
210
211 void
dnode_init(void)212 dnode_init(void)
213 {
214 ASSERT(dnode_cache == NULL);
215 dnode_cache = kmem_cache_create("dnode_t",
216 sizeof (dnode_t),
217 0, dnode_cons, dnode_dest, NULL, NULL, NULL, 0);
218 kmem_cache_set_move(dnode_cache, dnode_move);
219 }
220
221 void
dnode_fini(void)222 dnode_fini(void)
223 {
224 kmem_cache_destroy(dnode_cache);
225 dnode_cache = NULL;
226 }
227
228
229 #ifdef ZFS_DEBUG
230 void
dnode_verify(dnode_t * dn)231 dnode_verify(dnode_t *dn)
232 {
233 int drop_struct_lock = FALSE;
234
235 ASSERT(dn->dn_phys);
236 ASSERT(dn->dn_objset);
237 ASSERT(dn->dn_handle->dnh_dnode == dn);
238
239 ASSERT(DMU_OT_IS_VALID(dn->dn_phys->dn_type));
240
241 if (!(zfs_flags & ZFS_DEBUG_DNODE_VERIFY))
242 return;
243
244 if (!RW_WRITE_HELD(&dn->dn_struct_rwlock)) {
245 rw_enter(&dn->dn_struct_rwlock, RW_READER);
246 drop_struct_lock = TRUE;
247 }
248 if (dn->dn_phys->dn_type != DMU_OT_NONE || dn->dn_allocated_txg != 0) {
249 int i;
250 ASSERT3U(dn->dn_indblkshift, >=, 0);
251 ASSERT3U(dn->dn_indblkshift, <=, SPA_MAXBLOCKSHIFT);
252 if (dn->dn_datablkshift) {
253 ASSERT3U(dn->dn_datablkshift, >=, SPA_MINBLOCKSHIFT);
254 ASSERT3U(dn->dn_datablkshift, <=, SPA_MAXBLOCKSHIFT);
255 ASSERT3U(1<<dn->dn_datablkshift, ==, dn->dn_datablksz);
256 }
257 ASSERT3U(dn->dn_nlevels, <=, 30);
258 ASSERT(DMU_OT_IS_VALID(dn->dn_type));
259 ASSERT3U(dn->dn_nblkptr, >=, 1);
260 ASSERT3U(dn->dn_nblkptr, <=, DN_MAX_NBLKPTR);
261 ASSERT3U(dn->dn_bonuslen, <=, DN_MAX_BONUSLEN);
262 ASSERT3U(dn->dn_datablksz, ==,
263 dn->dn_datablkszsec << SPA_MINBLOCKSHIFT);
264 ASSERT3U(ISP2(dn->dn_datablksz), ==, dn->dn_datablkshift != 0);
265 ASSERT3U((dn->dn_nblkptr - 1) * sizeof (blkptr_t) +
266 dn->dn_bonuslen, <=, DN_MAX_BONUSLEN);
267 for (i = 0; i < TXG_SIZE; i++) {
268 ASSERT3U(dn->dn_next_nlevels[i], <=, dn->dn_nlevels);
269 }
270 }
271 if (dn->dn_phys->dn_type != DMU_OT_NONE)
272 ASSERT3U(dn->dn_phys->dn_nlevels, <=, dn->dn_nlevels);
273 ASSERT(DMU_OBJECT_IS_SPECIAL(dn->dn_object) || dn->dn_dbuf != NULL);
274 if (dn->dn_dbuf != NULL) {
275 ASSERT3P(dn->dn_phys, ==,
276 (dnode_phys_t *)dn->dn_dbuf->db.db_data +
277 (dn->dn_object % (dn->dn_dbuf->db.db_size >> DNODE_SHIFT)));
278 }
279 if (drop_struct_lock)
280 rw_exit(&dn->dn_struct_rwlock);
281 }
282 #endif
283
284 void
dnode_byteswap(dnode_phys_t * dnp)285 dnode_byteswap(dnode_phys_t *dnp)
286 {
287 uint64_t *buf64 = (void*)&dnp->dn_blkptr;
288 int i;
289
290 if (dnp->dn_type == DMU_OT_NONE) {
291 bzero(dnp, sizeof (dnode_phys_t));
292 return;
293 }
294
295 dnp->dn_datablkszsec = BSWAP_16(dnp->dn_datablkszsec);
296 dnp->dn_bonuslen = BSWAP_16(dnp->dn_bonuslen);
297 dnp->dn_maxblkid = BSWAP_64(dnp->dn_maxblkid);
298 dnp->dn_used = BSWAP_64(dnp->dn_used);
299
300 /*
301 * dn_nblkptr is only one byte, so it's OK to read it in either
302 * byte order. We can't read dn_bouslen.
303 */
304 ASSERT(dnp->dn_indblkshift <= SPA_MAXBLOCKSHIFT);
305 ASSERT(dnp->dn_nblkptr <= DN_MAX_NBLKPTR);
306 for (i = 0; i < dnp->dn_nblkptr * sizeof (blkptr_t)/8; i++)
307 buf64[i] = BSWAP_64(buf64[i]);
308
309 /*
310 * OK to check dn_bonuslen for zero, because it won't matter if
311 * we have the wrong byte order. This is necessary because the
312 * dnode dnode is smaller than a regular dnode.
313 */
314 if (dnp->dn_bonuslen != 0) {
315 /*
316 * Note that the bonus length calculated here may be
317 * longer than the actual bonus buffer. This is because
318 * we always put the bonus buffer after the last block
319 * pointer (instead of packing it against the end of the
320 * dnode buffer).
321 */
322 int off = (dnp->dn_nblkptr-1) * sizeof (blkptr_t);
323 size_t len = DN_MAX_BONUSLEN - off;
324 ASSERT(DMU_OT_IS_VALID(dnp->dn_bonustype));
325 dmu_object_byteswap_t byteswap =
326 DMU_OT_BYTESWAP(dnp->dn_bonustype);
327 dmu_ot_byteswap[byteswap].ob_func(dnp->dn_bonus + off, len);
328 }
329
330 /* Swap SPILL block if we have one */
331 if (dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR)
332 byteswap_uint64_array(&dnp->dn_spill, sizeof (blkptr_t));
333
334 }
335
336 void
dnode_buf_byteswap(void * vbuf,size_t size)337 dnode_buf_byteswap(void *vbuf, size_t size)
338 {
339 dnode_phys_t *buf = vbuf;
340 int i;
341
342 ASSERT3U(sizeof (dnode_phys_t), ==, (1<<DNODE_SHIFT));
343 ASSERT((size & (sizeof (dnode_phys_t)-1)) == 0);
344
345 size >>= DNODE_SHIFT;
346 for (i = 0; i < size; i++) {
347 dnode_byteswap(buf);
348 buf++;
349 }
350 }
351
352 void
dnode_setbonuslen(dnode_t * dn,int newsize,dmu_tx_t * tx)353 dnode_setbonuslen(dnode_t *dn, int newsize, dmu_tx_t *tx)
354 {
355 ASSERT3U(refcount_count(&dn->dn_holds), >=, 1);
356
357 dnode_setdirty(dn, tx);
358 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
359 ASSERT3U(newsize, <=, DN_MAX_BONUSLEN -
360 (dn->dn_nblkptr-1) * sizeof (blkptr_t));
361 dn->dn_bonuslen = newsize;
362 if (newsize == 0)
363 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = DN_ZERO_BONUSLEN;
364 else
365 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = dn->dn_bonuslen;
366 rw_exit(&dn->dn_struct_rwlock);
367 }
368
369 void
dnode_setbonus_type(dnode_t * dn,dmu_object_type_t newtype,dmu_tx_t * tx)370 dnode_setbonus_type(dnode_t *dn, dmu_object_type_t newtype, dmu_tx_t *tx)
371 {
372 ASSERT3U(refcount_count(&dn->dn_holds), >=, 1);
373 dnode_setdirty(dn, tx);
374 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
375 dn->dn_bonustype = newtype;
376 dn->dn_next_bonustype[tx->tx_txg & TXG_MASK] = dn->dn_bonustype;
377 rw_exit(&dn->dn_struct_rwlock);
378 }
379
380 void
dnode_rm_spill(dnode_t * dn,dmu_tx_t * tx)381 dnode_rm_spill(dnode_t *dn, dmu_tx_t *tx)
382 {
383 ASSERT3U(refcount_count(&dn->dn_holds), >=, 1);
384 ASSERT(RW_WRITE_HELD(&dn->dn_struct_rwlock));
385 dnode_setdirty(dn, tx);
386 dn->dn_rm_spillblk[tx->tx_txg&TXG_MASK] = DN_KILL_SPILLBLK;
387 dn->dn_have_spill = B_FALSE;
388 }
389
390 static void
dnode_setdblksz(dnode_t * dn,int size)391 dnode_setdblksz(dnode_t *dn, int size)
392 {
393 ASSERT0(P2PHASE(size, SPA_MINBLOCKSIZE));
394 ASSERT3U(size, <=, SPA_MAXBLOCKSIZE);
395 ASSERT3U(size, >=, SPA_MINBLOCKSIZE);
396 ASSERT3U(size >> SPA_MINBLOCKSHIFT, <,
397 1<<(sizeof (dn->dn_phys->dn_datablkszsec) * 8));
398 dn->dn_datablksz = size;
399 dn->dn_datablkszsec = size >> SPA_MINBLOCKSHIFT;
400 dn->dn_datablkshift = ISP2(size) ? highbit64(size - 1) : 0;
401 }
402
403 static dnode_t *
dnode_create(objset_t * os,dnode_phys_t * dnp,dmu_buf_impl_t * db,uint64_t object,dnode_handle_t * dnh)404 dnode_create(objset_t *os, dnode_phys_t *dnp, dmu_buf_impl_t *db,
405 uint64_t object, dnode_handle_t *dnh)
406 {
407 dnode_t *dn;
408
409 dn = kmem_cache_alloc(dnode_cache, KM_SLEEP);
410 ASSERT(!POINTER_IS_VALID(dn->dn_objset));
411 dn->dn_moved = 0;
412
413 /*
414 * Defer setting dn_objset until the dnode is ready to be a candidate
415 * for the dnode_move() callback.
416 */
417 dn->dn_object = object;
418 dn->dn_dbuf = db;
419 dn->dn_handle = dnh;
420 dn->dn_phys = dnp;
421
422 if (dnp->dn_datablkszsec) {
423 dnode_setdblksz(dn, dnp->dn_datablkszsec << SPA_MINBLOCKSHIFT);
424 } else {
425 dn->dn_datablksz = 0;
426 dn->dn_datablkszsec = 0;
427 dn->dn_datablkshift = 0;
428 }
429 dn->dn_indblkshift = dnp->dn_indblkshift;
430 dn->dn_nlevels = dnp->dn_nlevels;
431 dn->dn_type = dnp->dn_type;
432 dn->dn_nblkptr = dnp->dn_nblkptr;
433 dn->dn_checksum = dnp->dn_checksum;
434 dn->dn_compress = dnp->dn_compress;
435 dn->dn_bonustype = dnp->dn_bonustype;
436 dn->dn_bonuslen = dnp->dn_bonuslen;
437 dn->dn_maxblkid = dnp->dn_maxblkid;
438 dn->dn_have_spill = ((dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) != 0);
439 dn->dn_id_flags = 0;
440
441 dmu_zfetch_init(&dn->dn_zfetch, dn);
442
443 ASSERT(DMU_OT_IS_VALID(dn->dn_phys->dn_type));
444
445 mutex_enter(&os->os_lock);
446 if (dnh->dnh_dnode != NULL) {
447 /* Lost the allocation race. */
448 mutex_exit(&os->os_lock);
449 kmem_cache_free(dnode_cache, dn);
450 return (dnh->dnh_dnode);
451 }
452
453 /*
454 * Exclude special dnodes from os_dnodes so an empty os_dnodes
455 * signifies that the special dnodes have no references from
456 * their children (the entries in os_dnodes). This allows
457 * dnode_destroy() to easily determine if the last child has
458 * been removed and then complete eviction of the objset.
459 */
460 if (!DMU_OBJECT_IS_SPECIAL(object))
461 list_insert_head(&os->os_dnodes, dn);
462 membar_producer();
463
464 /*
465 * Everything else must be valid before assigning dn_objset
466 * makes the dnode eligible for dnode_move().
467 */
468 dn->dn_objset = os;
469
470 dnh->dnh_dnode = dn;
471 mutex_exit(&os->os_lock);
472
473 arc_space_consume(sizeof (dnode_t), ARC_SPACE_OTHER);
474 return (dn);
475 }
476
477 /*
478 * Caller must be holding the dnode handle, which is released upon return.
479 */
480 static void
dnode_destroy(dnode_t * dn)481 dnode_destroy(dnode_t *dn)
482 {
483 objset_t *os = dn->dn_objset;
484 boolean_t complete_os_eviction = B_FALSE;
485
486 ASSERT((dn->dn_id_flags & DN_ID_NEW_EXIST) == 0);
487
488 mutex_enter(&os->os_lock);
489 POINTER_INVALIDATE(&dn->dn_objset);
490 if (!DMU_OBJECT_IS_SPECIAL(dn->dn_object)) {
491 list_remove(&os->os_dnodes, dn);
492 complete_os_eviction =
493 list_is_empty(&os->os_dnodes) &&
494 list_link_active(&os->os_evicting_node);
495 }
496 mutex_exit(&os->os_lock);
497
498 /* the dnode can no longer move, so we can release the handle */
499 zrl_remove(&dn->dn_handle->dnh_zrlock);
500
501 dn->dn_allocated_txg = 0;
502 dn->dn_free_txg = 0;
503 dn->dn_assigned_txg = 0;
504
505 dn->dn_dirtyctx = 0;
506 if (dn->dn_dirtyctx_firstset != NULL) {
507 kmem_free(dn->dn_dirtyctx_firstset, 1);
508 dn->dn_dirtyctx_firstset = NULL;
509 }
510 if (dn->dn_bonus != NULL) {
511 mutex_enter(&dn->dn_bonus->db_mtx);
512 dbuf_evict(dn->dn_bonus);
513 dn->dn_bonus = NULL;
514 }
515 dn->dn_zio = NULL;
516
517 dn->dn_have_spill = B_FALSE;
518 dn->dn_oldused = 0;
519 dn->dn_oldflags = 0;
520 dn->dn_olduid = 0;
521 dn->dn_oldgid = 0;
522 dn->dn_newuid = 0;
523 dn->dn_newgid = 0;
524 dn->dn_id_flags = 0;
525 dn->dn_unlisted_l0_blkid = 0;
526
527 dmu_zfetch_fini(&dn->dn_zfetch);
528 kmem_cache_free(dnode_cache, dn);
529 arc_space_return(sizeof (dnode_t), ARC_SPACE_OTHER);
530
531 if (complete_os_eviction)
532 dmu_objset_evict_done(os);
533 }
534
535 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)536 dnode_allocate(dnode_t *dn, dmu_object_type_t ot, int blocksize, int ibs,
537 dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx)
538 {
539 int i;
540
541 ASSERT3U(blocksize, <=,
542 spa_maxblocksize(dmu_objset_spa(dn->dn_objset)));
543 if (blocksize == 0)
544 blocksize = 1 << zfs_default_bs;
545 else
546 blocksize = P2ROUNDUP(blocksize, SPA_MINBLOCKSIZE);
547
548 if (ibs == 0)
549 ibs = zfs_default_ibs;
550
551 ibs = MIN(MAX(ibs, DN_MIN_INDBLKSHIFT), DN_MAX_INDBLKSHIFT);
552
553 dprintf("os=%p obj=%llu txg=%llu blocksize=%d ibs=%d\n", dn->dn_objset,
554 dn->dn_object, tx->tx_txg, blocksize, ibs);
555
556 ASSERT(dn->dn_type == DMU_OT_NONE);
557 ASSERT(bcmp(dn->dn_phys, &dnode_phys_zero, sizeof (dnode_phys_t)) == 0);
558 ASSERT(dn->dn_phys->dn_type == DMU_OT_NONE);
559 ASSERT(ot != DMU_OT_NONE);
560 ASSERT(DMU_OT_IS_VALID(ot));
561 ASSERT((bonustype == DMU_OT_NONE && bonuslen == 0) ||
562 (bonustype == DMU_OT_SA && bonuslen == 0) ||
563 (bonustype != DMU_OT_NONE && bonuslen != 0));
564 ASSERT(DMU_OT_IS_VALID(bonustype));
565 ASSERT3U(bonuslen, <=, DN_MAX_BONUSLEN);
566 ASSERT(dn->dn_type == DMU_OT_NONE);
567 ASSERT0(dn->dn_maxblkid);
568 ASSERT0(dn->dn_allocated_txg);
569 ASSERT0(dn->dn_assigned_txg);
570 ASSERT(refcount_is_zero(&dn->dn_tx_holds));
571 ASSERT3U(refcount_count(&dn->dn_holds), <=, 1);
572 ASSERT(avl_is_empty(&dn->dn_dbufs));
573
574 for (i = 0; i < TXG_SIZE; i++) {
575 ASSERT0(dn->dn_next_nblkptr[i]);
576 ASSERT0(dn->dn_next_nlevels[i]);
577 ASSERT0(dn->dn_next_indblkshift[i]);
578 ASSERT0(dn->dn_next_bonuslen[i]);
579 ASSERT0(dn->dn_next_bonustype[i]);
580 ASSERT0(dn->dn_rm_spillblk[i]);
581 ASSERT0(dn->dn_next_blksz[i]);
582 ASSERT(!list_link_active(&dn->dn_dirty_link[i]));
583 ASSERT3P(list_head(&dn->dn_dirty_records[i]), ==, NULL);
584 ASSERT3P(dn->dn_free_ranges[i], ==, NULL);
585 }
586
587 dn->dn_type = ot;
588 dnode_setdblksz(dn, blocksize);
589 dn->dn_indblkshift = ibs;
590 dn->dn_nlevels = 1;
591 if (bonustype == DMU_OT_SA) /* Maximize bonus space for SA */
592 dn->dn_nblkptr = 1;
593 else
594 dn->dn_nblkptr = 1 +
595 ((DN_MAX_BONUSLEN - bonuslen) >> SPA_BLKPTRSHIFT);
596 dn->dn_bonustype = bonustype;
597 dn->dn_bonuslen = bonuslen;
598 dn->dn_checksum = ZIO_CHECKSUM_INHERIT;
599 dn->dn_compress = ZIO_COMPRESS_INHERIT;
600 dn->dn_dirtyctx = 0;
601
602 dn->dn_free_txg = 0;
603 if (dn->dn_dirtyctx_firstset) {
604 kmem_free(dn->dn_dirtyctx_firstset, 1);
605 dn->dn_dirtyctx_firstset = NULL;
606 }
607
608 dn->dn_allocated_txg = tx->tx_txg;
609 dn->dn_id_flags = 0;
610
611 dnode_setdirty(dn, tx);
612 dn->dn_next_indblkshift[tx->tx_txg & TXG_MASK] = ibs;
613 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = dn->dn_bonuslen;
614 dn->dn_next_bonustype[tx->tx_txg & TXG_MASK] = dn->dn_bonustype;
615 dn->dn_next_blksz[tx->tx_txg & TXG_MASK] = dn->dn_datablksz;
616 }
617
618 void
dnode_reallocate(dnode_t * dn,dmu_object_type_t ot,int blocksize,dmu_object_type_t bonustype,int bonuslen,dmu_tx_t * tx)619 dnode_reallocate(dnode_t *dn, dmu_object_type_t ot, int blocksize,
620 dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx)
621 {
622 int nblkptr;
623
624 ASSERT3U(blocksize, >=, SPA_MINBLOCKSIZE);
625 ASSERT3U(blocksize, <=,
626 spa_maxblocksize(dmu_objset_spa(dn->dn_objset)));
627 ASSERT0(blocksize % SPA_MINBLOCKSIZE);
628 ASSERT(dn->dn_object != DMU_META_DNODE_OBJECT || dmu_tx_private_ok(tx));
629 ASSERT(tx->tx_txg != 0);
630 ASSERT((bonustype == DMU_OT_NONE && bonuslen == 0) ||
631 (bonustype != DMU_OT_NONE && bonuslen != 0) ||
632 (bonustype == DMU_OT_SA && bonuslen == 0));
633 ASSERT(DMU_OT_IS_VALID(bonustype));
634 ASSERT3U(bonuslen, <=, DN_MAX_BONUSLEN);
635
636 /* clean up any unreferenced dbufs */
637 dnode_evict_dbufs(dn);
638
639 dn->dn_id_flags = 0;
640
641 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
642 dnode_setdirty(dn, tx);
643 if (dn->dn_datablksz != blocksize) {
644 /* change blocksize */
645 ASSERT(dn->dn_maxblkid == 0 &&
646 (BP_IS_HOLE(&dn->dn_phys->dn_blkptr[0]) ||
647 dnode_block_freed(dn, 0)));
648 dnode_setdblksz(dn, blocksize);
649 dn->dn_next_blksz[tx->tx_txg&TXG_MASK] = blocksize;
650 }
651 if (dn->dn_bonuslen != bonuslen)
652 dn->dn_next_bonuslen[tx->tx_txg&TXG_MASK] = bonuslen;
653
654 if (bonustype == DMU_OT_SA) /* Maximize bonus space for SA */
655 nblkptr = 1;
656 else
657 nblkptr = 1 + ((DN_MAX_BONUSLEN - bonuslen) >> SPA_BLKPTRSHIFT);
658 if (dn->dn_bonustype != bonustype)
659 dn->dn_next_bonustype[tx->tx_txg&TXG_MASK] = bonustype;
660 if (dn->dn_nblkptr != nblkptr)
661 dn->dn_next_nblkptr[tx->tx_txg&TXG_MASK] = nblkptr;
662 if (dn->dn_phys->dn_flags & DNODE_FLAG_SPILL_BLKPTR) {
663 dbuf_rm_spill(dn, tx);
664 dnode_rm_spill(dn, tx);
665 }
666 rw_exit(&dn->dn_struct_rwlock);
667
668 /* change type */
669 dn->dn_type = ot;
670
671 /* change bonus size and type */
672 mutex_enter(&dn->dn_mtx);
673 dn->dn_bonustype = bonustype;
674 dn->dn_bonuslen = bonuslen;
675 dn->dn_nblkptr = nblkptr;
676 dn->dn_checksum = ZIO_CHECKSUM_INHERIT;
677 dn->dn_compress = ZIO_COMPRESS_INHERIT;
678 ASSERT3U(dn->dn_nblkptr, <=, DN_MAX_NBLKPTR);
679
680 /* fix up the bonus db_size */
681 if (dn->dn_bonus) {
682 dn->dn_bonus->db.db_size =
683 DN_MAX_BONUSLEN - (dn->dn_nblkptr-1) * sizeof (blkptr_t);
684 ASSERT(dn->dn_bonuslen <= dn->dn_bonus->db.db_size);
685 }
686
687 dn->dn_allocated_txg = tx->tx_txg;
688 mutex_exit(&dn->dn_mtx);
689 }
690
691 #ifdef DNODE_STATS
692 static struct {
693 uint64_t dms_dnode_invalid;
694 uint64_t dms_dnode_recheck1;
695 uint64_t dms_dnode_recheck2;
696 uint64_t dms_dnode_special;
697 uint64_t dms_dnode_handle;
698 uint64_t dms_dnode_rwlock;
699 uint64_t dms_dnode_active;
700 } dnode_move_stats;
701 #endif /* DNODE_STATS */
702
703 static void
dnode_move_impl(dnode_t * odn,dnode_t * ndn)704 dnode_move_impl(dnode_t *odn, dnode_t *ndn)
705 {
706 int i;
707
708 ASSERT(!RW_LOCK_HELD(&odn->dn_struct_rwlock));
709 ASSERT(MUTEX_NOT_HELD(&odn->dn_mtx));
710 ASSERT(MUTEX_NOT_HELD(&odn->dn_dbufs_mtx));
711 ASSERT(!RW_LOCK_HELD(&odn->dn_zfetch.zf_rwlock));
712
713 /* Copy fields. */
714 ndn->dn_objset = odn->dn_objset;
715 ndn->dn_object = odn->dn_object;
716 ndn->dn_dbuf = odn->dn_dbuf;
717 ndn->dn_handle = odn->dn_handle;
718 ndn->dn_phys = odn->dn_phys;
719 ndn->dn_type = odn->dn_type;
720 ndn->dn_bonuslen = odn->dn_bonuslen;
721 ndn->dn_bonustype = odn->dn_bonustype;
722 ndn->dn_nblkptr = odn->dn_nblkptr;
723 ndn->dn_checksum = odn->dn_checksum;
724 ndn->dn_compress = odn->dn_compress;
725 ndn->dn_nlevels = odn->dn_nlevels;
726 ndn->dn_indblkshift = odn->dn_indblkshift;
727 ndn->dn_datablkshift = odn->dn_datablkshift;
728 ndn->dn_datablkszsec = odn->dn_datablkszsec;
729 ndn->dn_datablksz = odn->dn_datablksz;
730 ndn->dn_maxblkid = odn->dn_maxblkid;
731 bcopy(&odn->dn_next_nblkptr[0], &ndn->dn_next_nblkptr[0],
732 sizeof (odn->dn_next_nblkptr));
733 bcopy(&odn->dn_next_nlevels[0], &ndn->dn_next_nlevels[0],
734 sizeof (odn->dn_next_nlevels));
735 bcopy(&odn->dn_next_indblkshift[0], &ndn->dn_next_indblkshift[0],
736 sizeof (odn->dn_next_indblkshift));
737 bcopy(&odn->dn_next_bonustype[0], &ndn->dn_next_bonustype[0],
738 sizeof (odn->dn_next_bonustype));
739 bcopy(&odn->dn_rm_spillblk[0], &ndn->dn_rm_spillblk[0],
740 sizeof (odn->dn_rm_spillblk));
741 bcopy(&odn->dn_next_bonuslen[0], &ndn->dn_next_bonuslen[0],
742 sizeof (odn->dn_next_bonuslen));
743 bcopy(&odn->dn_next_blksz[0], &ndn->dn_next_blksz[0],
744 sizeof (odn->dn_next_blksz));
745 for (i = 0; i < TXG_SIZE; i++) {
746 list_move_tail(&ndn->dn_dirty_records[i],
747 &odn->dn_dirty_records[i]);
748 }
749 bcopy(&odn->dn_free_ranges[0], &ndn->dn_free_ranges[0],
750 sizeof (odn->dn_free_ranges));
751 ndn->dn_allocated_txg = odn->dn_allocated_txg;
752 ndn->dn_free_txg = odn->dn_free_txg;
753 ndn->dn_assigned_txg = odn->dn_assigned_txg;
754 ndn->dn_dirtyctx = odn->dn_dirtyctx;
755 ndn->dn_dirtyctx_firstset = odn->dn_dirtyctx_firstset;
756 ASSERT(refcount_count(&odn->dn_tx_holds) == 0);
757 refcount_transfer(&ndn->dn_holds, &odn->dn_holds);
758 ASSERT(avl_is_empty(&ndn->dn_dbufs));
759 avl_swap(&ndn->dn_dbufs, &odn->dn_dbufs);
760 ndn->dn_dbufs_count = odn->dn_dbufs_count;
761 ndn->dn_unlisted_l0_blkid = odn->dn_unlisted_l0_blkid;
762 ndn->dn_bonus = odn->dn_bonus;
763 ndn->dn_have_spill = odn->dn_have_spill;
764 ndn->dn_zio = odn->dn_zio;
765 ndn->dn_oldused = odn->dn_oldused;
766 ndn->dn_oldflags = odn->dn_oldflags;
767 ndn->dn_olduid = odn->dn_olduid;
768 ndn->dn_oldgid = odn->dn_oldgid;
769 ndn->dn_newuid = odn->dn_newuid;
770 ndn->dn_newgid = odn->dn_newgid;
771 ndn->dn_id_flags = odn->dn_id_flags;
772 dmu_zfetch_init(&ndn->dn_zfetch, NULL);
773 list_move_tail(&ndn->dn_zfetch.zf_stream, &odn->dn_zfetch.zf_stream);
774 ndn->dn_zfetch.zf_dnode = odn->dn_zfetch.zf_dnode;
775
776 /*
777 * Update back pointers. Updating the handle fixes the back pointer of
778 * every descendant dbuf as well as the bonus dbuf.
779 */
780 ASSERT(ndn->dn_handle->dnh_dnode == odn);
781 ndn->dn_handle->dnh_dnode = ndn;
782 if (ndn->dn_zfetch.zf_dnode == odn) {
783 ndn->dn_zfetch.zf_dnode = ndn;
784 }
785
786 /*
787 * Invalidate the original dnode by clearing all of its back pointers.
788 */
789 odn->dn_dbuf = NULL;
790 odn->dn_handle = NULL;
791 avl_create(&odn->dn_dbufs, dbuf_compare, sizeof (dmu_buf_impl_t),
792 offsetof(dmu_buf_impl_t, db_link));
793 odn->dn_dbufs_count = 0;
794 odn->dn_unlisted_l0_blkid = 0;
795 odn->dn_bonus = NULL;
796 odn->dn_zfetch.zf_dnode = NULL;
797
798 /*
799 * Set the low bit of the objset pointer to ensure that dnode_move()
800 * recognizes the dnode as invalid in any subsequent callback.
801 */
802 POINTER_INVALIDATE(&odn->dn_objset);
803
804 /*
805 * Satisfy the destructor.
806 */
807 for (i = 0; i < TXG_SIZE; i++) {
808 list_create(&odn->dn_dirty_records[i],
809 sizeof (dbuf_dirty_record_t),
810 offsetof(dbuf_dirty_record_t, dr_dirty_node));
811 odn->dn_free_ranges[i] = NULL;
812 odn->dn_next_nlevels[i] = 0;
813 odn->dn_next_indblkshift[i] = 0;
814 odn->dn_next_bonustype[i] = 0;
815 odn->dn_rm_spillblk[i] = 0;
816 odn->dn_next_bonuslen[i] = 0;
817 odn->dn_next_blksz[i] = 0;
818 }
819 odn->dn_allocated_txg = 0;
820 odn->dn_free_txg = 0;
821 odn->dn_assigned_txg = 0;
822 odn->dn_dirtyctx = 0;
823 odn->dn_dirtyctx_firstset = NULL;
824 odn->dn_have_spill = B_FALSE;
825 odn->dn_zio = NULL;
826 odn->dn_oldused = 0;
827 odn->dn_oldflags = 0;
828 odn->dn_olduid = 0;
829 odn->dn_oldgid = 0;
830 odn->dn_newuid = 0;
831 odn->dn_newgid = 0;
832 odn->dn_id_flags = 0;
833
834 /*
835 * Mark the dnode.
836 */
837 ndn->dn_moved = 1;
838 odn->dn_moved = (uint8_t)-1;
839 }
840
841 #ifdef _KERNEL
842 /*ARGSUSED*/
843 static kmem_cbrc_t
dnode_move(void * buf,void * newbuf,size_t size,void * arg)844 dnode_move(void *buf, void *newbuf, size_t size, void *arg)
845 {
846 dnode_t *odn = buf, *ndn = newbuf;
847 objset_t *os;
848 int64_t refcount;
849 uint32_t dbufs;
850
851 /*
852 * The dnode is on the objset's list of known dnodes if the objset
853 * pointer is valid. We set the low bit of the objset pointer when
854 * freeing the dnode to invalidate it, and the memory patterns written
855 * by kmem (baddcafe and deadbeef) set at least one of the two low bits.
856 * A newly created dnode sets the objset pointer last of all to indicate
857 * that the dnode is known and in a valid state to be moved by this
858 * function.
859 */
860 os = odn->dn_objset;
861 if (!POINTER_IS_VALID(os)) {
862 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_invalid);
863 return (KMEM_CBRC_DONT_KNOW);
864 }
865
866 /*
867 * Ensure that the objset does not go away during the move.
868 */
869 rw_enter(&os_lock, RW_WRITER);
870 if (os != odn->dn_objset) {
871 rw_exit(&os_lock);
872 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_recheck1);
873 return (KMEM_CBRC_DONT_KNOW);
874 }
875
876 /*
877 * If the dnode is still valid, then so is the objset. We know that no
878 * valid objset can be freed while we hold os_lock, so we can safely
879 * ensure that the objset remains in use.
880 */
881 mutex_enter(&os->os_lock);
882
883 /*
884 * Recheck the objset pointer in case the dnode was removed just before
885 * acquiring the lock.
886 */
887 if (os != odn->dn_objset) {
888 mutex_exit(&os->os_lock);
889 rw_exit(&os_lock);
890 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_recheck2);
891 return (KMEM_CBRC_DONT_KNOW);
892 }
893
894 /*
895 * At this point we know that as long as we hold os->os_lock, the dnode
896 * cannot be freed and fields within the dnode can be safely accessed.
897 * The objset listing this dnode cannot go away as long as this dnode is
898 * on its list.
899 */
900 rw_exit(&os_lock);
901 if (DMU_OBJECT_IS_SPECIAL(odn->dn_object)) {
902 mutex_exit(&os->os_lock);
903 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_special);
904 return (KMEM_CBRC_NO);
905 }
906 ASSERT(odn->dn_dbuf != NULL); /* only "special" dnodes have no parent */
907
908 /*
909 * Lock the dnode handle to prevent the dnode from obtaining any new
910 * holds. This also prevents the descendant dbufs and the bonus dbuf
911 * from accessing the dnode, so that we can discount their holds. The
912 * handle is safe to access because we know that while the dnode cannot
913 * go away, neither can its handle. Once we hold dnh_zrlock, we can
914 * safely move any dnode referenced only by dbufs.
915 */
916 if (!zrl_tryenter(&odn->dn_handle->dnh_zrlock)) {
917 mutex_exit(&os->os_lock);
918 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_handle);
919 return (KMEM_CBRC_LATER);
920 }
921
922 /*
923 * Ensure a consistent view of the dnode's holds and the dnode's dbufs.
924 * We need to guarantee that there is a hold for every dbuf in order to
925 * determine whether the dnode is actively referenced. Falsely matching
926 * a dbuf to an active hold would lead to an unsafe move. It's possible
927 * that a thread already having an active dnode hold is about to add a
928 * dbuf, and we can't compare hold and dbuf counts while the add is in
929 * progress.
930 */
931 if (!rw_tryenter(&odn->dn_struct_rwlock, RW_WRITER)) {
932 zrl_exit(&odn->dn_handle->dnh_zrlock);
933 mutex_exit(&os->os_lock);
934 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_rwlock);
935 return (KMEM_CBRC_LATER);
936 }
937
938 /*
939 * A dbuf may be removed (evicted) without an active dnode hold. In that
940 * case, the dbuf count is decremented under the handle lock before the
941 * dbuf's hold is released. This order ensures that if we count the hold
942 * after the dbuf is removed but before its hold is released, we will
943 * treat the unmatched hold as active and exit safely. If we count the
944 * hold before the dbuf is removed, the hold is discounted, and the
945 * removal is blocked until the move completes.
946 */
947 refcount = refcount_count(&odn->dn_holds);
948 ASSERT(refcount >= 0);
949 dbufs = odn->dn_dbufs_count;
950
951 /* We can't have more dbufs than dnode holds. */
952 ASSERT3U(dbufs, <=, refcount);
953 DTRACE_PROBE3(dnode__move, dnode_t *, odn, int64_t, refcount,
954 uint32_t, dbufs);
955
956 if (refcount > dbufs) {
957 rw_exit(&odn->dn_struct_rwlock);
958 zrl_exit(&odn->dn_handle->dnh_zrlock);
959 mutex_exit(&os->os_lock);
960 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_active);
961 return (KMEM_CBRC_LATER);
962 }
963
964 rw_exit(&odn->dn_struct_rwlock);
965
966 /*
967 * At this point we know that anyone with a hold on the dnode is not
968 * actively referencing it. The dnode is known and in a valid state to
969 * move. We're holding the locks needed to execute the critical section.
970 */
971 dnode_move_impl(odn, ndn);
972
973 list_link_replace(&odn->dn_link, &ndn->dn_link);
974 /* If the dnode was safe to move, the refcount cannot have changed. */
975 ASSERT(refcount == refcount_count(&ndn->dn_holds));
976 ASSERT(dbufs == ndn->dn_dbufs_count);
977 zrl_exit(&ndn->dn_handle->dnh_zrlock); /* handle has moved */
978 mutex_exit(&os->os_lock);
979
980 return (KMEM_CBRC_YES);
981 }
982 #endif /* _KERNEL */
983
984 void
dnode_special_close(dnode_handle_t * dnh)985 dnode_special_close(dnode_handle_t *dnh)
986 {
987 dnode_t *dn = dnh->dnh_dnode;
988
989 /*
990 * Wait for final references to the dnode to clear. This can
991 * only happen if the arc is asyncronously evicting state that
992 * has a hold on this dnode while we are trying to evict this
993 * dnode.
994 */
995 while (refcount_count(&dn->dn_holds) > 0)
996 delay(1);
997 ASSERT(dn->dn_dbuf == NULL ||
998 dmu_buf_get_user(&dn->dn_dbuf->db) == NULL);
999 zrl_add(&dnh->dnh_zrlock);
1000 dnode_destroy(dn); /* implicit zrl_remove() */
1001 zrl_destroy(&dnh->dnh_zrlock);
1002 dnh->dnh_dnode = NULL;
1003 }
1004
1005 void
dnode_special_open(objset_t * os,dnode_phys_t * dnp,uint64_t object,dnode_handle_t * dnh)1006 dnode_special_open(objset_t *os, dnode_phys_t *dnp, uint64_t object,
1007 dnode_handle_t *dnh)
1008 {
1009 dnode_t *dn;
1010
1011 dn = dnode_create(os, dnp, NULL, object, dnh);
1012 zrl_init(&dnh->dnh_zrlock);
1013 DNODE_VERIFY(dn);
1014 }
1015
1016 static void
dnode_buf_evict_async(void * dbu)1017 dnode_buf_evict_async(void *dbu)
1018 {
1019 dnode_children_t *children_dnodes = dbu;
1020 int i;
1021
1022 for (i = 0; i < children_dnodes->dnc_count; i++) {
1023 dnode_handle_t *dnh = &children_dnodes->dnc_children[i];
1024 dnode_t *dn;
1025
1026 /*
1027 * The dnode handle lock guards against the dnode moving to
1028 * another valid address, so there is no need here to guard
1029 * against changes to or from NULL.
1030 */
1031 if (dnh->dnh_dnode == NULL) {
1032 zrl_destroy(&dnh->dnh_zrlock);
1033 continue;
1034 }
1035
1036 zrl_add(&dnh->dnh_zrlock);
1037 dn = dnh->dnh_dnode;
1038 /*
1039 * If there are holds on this dnode, then there should
1040 * be holds on the dnode's containing dbuf as well; thus
1041 * it wouldn't be eligible for eviction and this function
1042 * would not have been called.
1043 */
1044 ASSERT(refcount_is_zero(&dn->dn_holds));
1045 ASSERT(refcount_is_zero(&dn->dn_tx_holds));
1046
1047 dnode_destroy(dn); /* implicit zrl_remove() */
1048 zrl_destroy(&dnh->dnh_zrlock);
1049 dnh->dnh_dnode = NULL;
1050 }
1051 kmem_free(children_dnodes, sizeof (dnode_children_t) +
1052 children_dnodes->dnc_count * sizeof (dnode_handle_t));
1053 }
1054
1055 /*
1056 * errors:
1057 * EINVAL - invalid object number.
1058 * EIO - i/o error.
1059 * succeeds even for free dnodes.
1060 */
1061 int
dnode_hold_impl(objset_t * os,uint64_t object,int flag,void * tag,dnode_t ** dnp)1062 dnode_hold_impl(objset_t *os, uint64_t object, int flag,
1063 void *tag, dnode_t **dnp)
1064 {
1065 int epb, idx, err;
1066 int drop_struct_lock = FALSE;
1067 int type;
1068 uint64_t blk;
1069 dnode_t *mdn, *dn;
1070 dmu_buf_impl_t *db;
1071 dnode_children_t *children_dnodes;
1072 dnode_handle_t *dnh;
1073
1074 /*
1075 * If you are holding the spa config lock as writer, you shouldn't
1076 * be asking the DMU to do *anything* unless it's the root pool
1077 * which may require us to read from the root filesystem while
1078 * holding some (not all) of the locks as writer.
1079 */
1080 ASSERT(spa_config_held(os->os_spa, SCL_ALL, RW_WRITER) == 0 ||
1081 (spa_is_root(os->os_spa) &&
1082 spa_config_held(os->os_spa, SCL_STATE, RW_WRITER)));
1083
1084 if (object == DMU_USERUSED_OBJECT || object == DMU_GROUPUSED_OBJECT) {
1085 dn = (object == DMU_USERUSED_OBJECT) ?
1086 DMU_USERUSED_DNODE(os) : DMU_GROUPUSED_DNODE(os);
1087 if (dn == NULL)
1088 return (SET_ERROR(ENOENT));
1089 type = dn->dn_type;
1090 if ((flag & DNODE_MUST_BE_ALLOCATED) && type == DMU_OT_NONE)
1091 return (SET_ERROR(ENOENT));
1092 if ((flag & DNODE_MUST_BE_FREE) && type != DMU_OT_NONE)
1093 return (SET_ERROR(EEXIST));
1094 DNODE_VERIFY(dn);
1095 (void) refcount_add(&dn->dn_holds, tag);
1096 *dnp = dn;
1097 return (0);
1098 }
1099
1100 if (object == 0 || object >= DN_MAX_OBJECT)
1101 return (SET_ERROR(EINVAL));
1102
1103 mdn = DMU_META_DNODE(os);
1104 ASSERT(mdn->dn_object == DMU_META_DNODE_OBJECT);
1105
1106 DNODE_VERIFY(mdn);
1107
1108 if (!RW_WRITE_HELD(&mdn->dn_struct_rwlock)) {
1109 rw_enter(&mdn->dn_struct_rwlock, RW_READER);
1110 drop_struct_lock = TRUE;
1111 }
1112
1113 blk = dbuf_whichblock(mdn, 0, object * sizeof (dnode_phys_t));
1114
1115 db = dbuf_hold(mdn, blk, FTAG);
1116 if (drop_struct_lock)
1117 rw_exit(&mdn->dn_struct_rwlock);
1118 if (db == NULL)
1119 return (SET_ERROR(EIO));
1120 err = dbuf_read(db, NULL, DB_RF_CANFAIL);
1121 if (err) {
1122 dbuf_rele(db, FTAG);
1123 return (err);
1124 }
1125
1126 ASSERT3U(db->db.db_size, >=, 1<<DNODE_SHIFT);
1127 epb = db->db.db_size >> DNODE_SHIFT;
1128
1129 idx = object & (epb-1);
1130
1131 ASSERT(DB_DNODE(db)->dn_type == DMU_OT_DNODE);
1132 children_dnodes = dmu_buf_get_user(&db->db);
1133 if (children_dnodes == NULL) {
1134 int i;
1135 dnode_children_t *winner;
1136 children_dnodes = kmem_zalloc(sizeof (dnode_children_t) +
1137 epb * sizeof (dnode_handle_t), KM_SLEEP);
1138 children_dnodes->dnc_count = epb;
1139 dnh = &children_dnodes->dnc_children[0];
1140 for (i = 0; i < epb; i++) {
1141 zrl_init(&dnh[i].dnh_zrlock);
1142 }
1143 dmu_buf_init_user(&children_dnodes->dnc_dbu, NULL,
1144 dnode_buf_evict_async, NULL);
1145 winner = dmu_buf_set_user(&db->db, &children_dnodes->dnc_dbu);
1146 if (winner != NULL) {
1147
1148 for (i = 0; i < epb; i++) {
1149 zrl_destroy(&dnh[i].dnh_zrlock);
1150 }
1151
1152 kmem_free(children_dnodes, sizeof (dnode_children_t) +
1153 epb * sizeof (dnode_handle_t));
1154 children_dnodes = winner;
1155 }
1156 }
1157 ASSERT(children_dnodes->dnc_count == epb);
1158
1159 dnh = &children_dnodes->dnc_children[idx];
1160 zrl_add(&dnh->dnh_zrlock);
1161 dn = dnh->dnh_dnode;
1162 if (dn == NULL) {
1163 dnode_phys_t *phys = (dnode_phys_t *)db->db.db_data+idx;
1164
1165 dn = dnode_create(os, phys, db, object, dnh);
1166 }
1167
1168 mutex_enter(&dn->dn_mtx);
1169 type = dn->dn_type;
1170 if (dn->dn_free_txg ||
1171 ((flag & DNODE_MUST_BE_ALLOCATED) && type == DMU_OT_NONE) ||
1172 ((flag & DNODE_MUST_BE_FREE) &&
1173 (type != DMU_OT_NONE || !refcount_is_zero(&dn->dn_holds)))) {
1174 mutex_exit(&dn->dn_mtx);
1175 zrl_remove(&dnh->dnh_zrlock);
1176 dbuf_rele(db, FTAG);
1177 return (type == DMU_OT_NONE ? ENOENT : EEXIST);
1178 }
1179 if (refcount_add(&dn->dn_holds, tag) == 1)
1180 dbuf_add_ref(db, dnh);
1181 mutex_exit(&dn->dn_mtx);
1182
1183 /* Now we can rely on the hold to prevent the dnode from moving. */
1184 zrl_remove(&dnh->dnh_zrlock);
1185
1186 DNODE_VERIFY(dn);
1187 ASSERT3P(dn->dn_dbuf, ==, db);
1188 ASSERT3U(dn->dn_object, ==, object);
1189 dbuf_rele(db, FTAG);
1190
1191 *dnp = dn;
1192 return (0);
1193 }
1194
1195 /*
1196 * Return held dnode if the object is allocated, NULL if not.
1197 */
1198 int
dnode_hold(objset_t * os,uint64_t object,void * tag,dnode_t ** dnp)1199 dnode_hold(objset_t *os, uint64_t object, void *tag, dnode_t **dnp)
1200 {
1201 return (dnode_hold_impl(os, object, DNODE_MUST_BE_ALLOCATED, tag, dnp));
1202 }
1203
1204 /*
1205 * Can only add a reference if there is already at least one
1206 * reference on the dnode. Returns FALSE if unable to add a
1207 * new reference.
1208 */
1209 boolean_t
dnode_add_ref(dnode_t * dn,void * tag)1210 dnode_add_ref(dnode_t *dn, void *tag)
1211 {
1212 mutex_enter(&dn->dn_mtx);
1213 if (refcount_is_zero(&dn->dn_holds)) {
1214 mutex_exit(&dn->dn_mtx);
1215 return (FALSE);
1216 }
1217 VERIFY(1 < refcount_add(&dn->dn_holds, tag));
1218 mutex_exit(&dn->dn_mtx);
1219 return (TRUE);
1220 }
1221
1222 void
dnode_rele(dnode_t * dn,void * tag)1223 dnode_rele(dnode_t *dn, void *tag)
1224 {
1225 mutex_enter(&dn->dn_mtx);
1226 dnode_rele_and_unlock(dn, tag);
1227 }
1228
1229 void
dnode_rele_and_unlock(dnode_t * dn,void * tag)1230 dnode_rele_and_unlock(dnode_t *dn, void *tag)
1231 {
1232 uint64_t refs;
1233 /* Get while the hold prevents the dnode from moving. */
1234 dmu_buf_impl_t *db = dn->dn_dbuf;
1235 dnode_handle_t *dnh = dn->dn_handle;
1236
1237 refs = refcount_remove(&dn->dn_holds, tag);
1238 mutex_exit(&dn->dn_mtx);
1239
1240 /*
1241 * It's unsafe to release the last hold on a dnode by dnode_rele() or
1242 * indirectly by dbuf_rele() while relying on the dnode handle to
1243 * prevent the dnode from moving, since releasing the last hold could
1244 * result in the dnode's parent dbuf evicting its dnode handles. For
1245 * that reason anyone calling dnode_rele() or dbuf_rele() without some
1246 * other direct or indirect hold on the dnode must first drop the dnode
1247 * handle.
1248 */
1249 ASSERT(refs > 0 || dnh->dnh_zrlock.zr_owner != curthread);
1250
1251 /* NOTE: the DNODE_DNODE does not have a dn_dbuf */
1252 if (refs == 0 && db != NULL) {
1253 /*
1254 * Another thread could add a hold to the dnode handle in
1255 * dnode_hold_impl() while holding the parent dbuf. Since the
1256 * hold on the parent dbuf prevents the handle from being
1257 * destroyed, the hold on the handle is OK. We can't yet assert
1258 * that the handle has zero references, but that will be
1259 * asserted anyway when the handle gets destroyed.
1260 */
1261 dbuf_rele(db, dnh);
1262 }
1263 }
1264
1265 void
dnode_setdirty(dnode_t * dn,dmu_tx_t * tx)1266 dnode_setdirty(dnode_t *dn, dmu_tx_t *tx)
1267 {
1268 objset_t *os = dn->dn_objset;
1269 uint64_t txg = tx->tx_txg;
1270
1271 if (DMU_OBJECT_IS_SPECIAL(dn->dn_object)) {
1272 dsl_dataset_dirty(os->os_dsl_dataset, tx);
1273 return;
1274 }
1275
1276 DNODE_VERIFY(dn);
1277
1278 #ifdef ZFS_DEBUG
1279 mutex_enter(&dn->dn_mtx);
1280 ASSERT(dn->dn_phys->dn_type || dn->dn_allocated_txg);
1281 ASSERT(dn->dn_free_txg == 0 || dn->dn_free_txg >= txg);
1282 mutex_exit(&dn->dn_mtx);
1283 #endif
1284
1285 /*
1286 * Determine old uid/gid when necessary
1287 */
1288 dmu_objset_userquota_get_ids(dn, B_TRUE, tx);
1289
1290 mutex_enter(&os->os_lock);
1291
1292 /*
1293 * If we are already marked dirty, we're done.
1294 */
1295 if (list_link_active(&dn->dn_dirty_link[txg & TXG_MASK])) {
1296 mutex_exit(&os->os_lock);
1297 return;
1298 }
1299
1300 ASSERT(!refcount_is_zero(&dn->dn_holds) ||
1301 !avl_is_empty(&dn->dn_dbufs));
1302 ASSERT(dn->dn_datablksz != 0);
1303 ASSERT0(dn->dn_next_bonuslen[txg&TXG_MASK]);
1304 ASSERT0(dn->dn_next_blksz[txg&TXG_MASK]);
1305 ASSERT0(dn->dn_next_bonustype[txg&TXG_MASK]);
1306
1307 dprintf_ds(os->os_dsl_dataset, "obj=%llu txg=%llu\n",
1308 dn->dn_object, txg);
1309
1310 if (dn->dn_free_txg > 0 && dn->dn_free_txg <= txg) {
1311 list_insert_tail(&os->os_free_dnodes[txg&TXG_MASK], dn);
1312 } else {
1313 list_insert_tail(&os->os_dirty_dnodes[txg&TXG_MASK], dn);
1314 }
1315
1316 mutex_exit(&os->os_lock);
1317
1318 /*
1319 * The dnode maintains a hold on its containing dbuf as
1320 * long as there are holds on it. Each instantiated child
1321 * dbuf maintains a hold on the dnode. When the last child
1322 * drops its hold, the dnode will drop its hold on the
1323 * containing dbuf. We add a "dirty hold" here so that the
1324 * dnode will hang around after we finish processing its
1325 * children.
1326 */
1327 VERIFY(dnode_add_ref(dn, (void *)(uintptr_t)tx->tx_txg));
1328
1329 (void) dbuf_dirty(dn->dn_dbuf, tx);
1330
1331 dsl_dataset_dirty(os->os_dsl_dataset, tx);
1332 }
1333
1334 void
dnode_free(dnode_t * dn,dmu_tx_t * tx)1335 dnode_free(dnode_t *dn, dmu_tx_t *tx)
1336 {
1337 int txgoff = tx->tx_txg & TXG_MASK;
1338
1339 dprintf("dn=%p txg=%llu\n", dn, tx->tx_txg);
1340
1341 /* we should be the only holder... hopefully */
1342 /* ASSERT3U(refcount_count(&dn->dn_holds), ==, 1); */
1343
1344 mutex_enter(&dn->dn_mtx);
1345 if (dn->dn_type == DMU_OT_NONE || dn->dn_free_txg) {
1346 mutex_exit(&dn->dn_mtx);
1347 return;
1348 }
1349 dn->dn_free_txg = tx->tx_txg;
1350 mutex_exit(&dn->dn_mtx);
1351
1352 /*
1353 * If the dnode is already dirty, it needs to be moved from
1354 * the dirty list to the free list.
1355 */
1356 mutex_enter(&dn->dn_objset->os_lock);
1357 if (list_link_active(&dn->dn_dirty_link[txgoff])) {
1358 list_remove(&dn->dn_objset->os_dirty_dnodes[txgoff], dn);
1359 list_insert_tail(&dn->dn_objset->os_free_dnodes[txgoff], dn);
1360 mutex_exit(&dn->dn_objset->os_lock);
1361 } else {
1362 mutex_exit(&dn->dn_objset->os_lock);
1363 dnode_setdirty(dn, tx);
1364 }
1365 }
1366
1367 /*
1368 * Try to change the block size for the indicated dnode. This can only
1369 * succeed if there are no blocks allocated or dirty beyond first block
1370 */
1371 int
dnode_set_blksz(dnode_t * dn,uint64_t size,int ibs,dmu_tx_t * tx)1372 dnode_set_blksz(dnode_t *dn, uint64_t size, int ibs, dmu_tx_t *tx)
1373 {
1374 dmu_buf_impl_t *db;
1375 int err;
1376
1377 ASSERT3U(size, <=, spa_maxblocksize(dmu_objset_spa(dn->dn_objset)));
1378 if (size == 0)
1379 size = SPA_MINBLOCKSIZE;
1380 else
1381 size = P2ROUNDUP(size, SPA_MINBLOCKSIZE);
1382
1383 if (ibs == dn->dn_indblkshift)
1384 ibs = 0;
1385
1386 if (size >> SPA_MINBLOCKSHIFT == dn->dn_datablkszsec && ibs == 0)
1387 return (0);
1388
1389 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
1390
1391 /* Check for any allocated blocks beyond the first */
1392 if (dn->dn_maxblkid != 0)
1393 goto fail;
1394
1395 mutex_enter(&dn->dn_dbufs_mtx);
1396 for (db = avl_first(&dn->dn_dbufs); db != NULL;
1397 db = AVL_NEXT(&dn->dn_dbufs, db)) {
1398 if (db->db_blkid != 0 && db->db_blkid != DMU_BONUS_BLKID &&
1399 db->db_blkid != DMU_SPILL_BLKID) {
1400 mutex_exit(&dn->dn_dbufs_mtx);
1401 goto fail;
1402 }
1403 }
1404 mutex_exit(&dn->dn_dbufs_mtx);
1405
1406 if (ibs && dn->dn_nlevels != 1)
1407 goto fail;
1408
1409 /* resize the old block */
1410 err = dbuf_hold_impl(dn, 0, 0, TRUE, FALSE, FTAG, &db);
1411 if (err == 0)
1412 dbuf_new_size(db, size, tx);
1413 else if (err != ENOENT)
1414 goto fail;
1415
1416 dnode_setdblksz(dn, size);
1417 dnode_setdirty(dn, tx);
1418 dn->dn_next_blksz[tx->tx_txg&TXG_MASK] = size;
1419 if (ibs) {
1420 dn->dn_indblkshift = ibs;
1421 dn->dn_next_indblkshift[tx->tx_txg&TXG_MASK] = ibs;
1422 }
1423 /* rele after we have fixed the blocksize in the dnode */
1424 if (db)
1425 dbuf_rele(db, FTAG);
1426
1427 rw_exit(&dn->dn_struct_rwlock);
1428 return (0);
1429
1430 fail:
1431 rw_exit(&dn->dn_struct_rwlock);
1432 return (SET_ERROR(ENOTSUP));
1433 }
1434
1435 /* read-holding callers must not rely on the lock being continuously held */
1436 void
dnode_new_blkid(dnode_t * dn,uint64_t blkid,dmu_tx_t * tx,boolean_t have_read)1437 dnode_new_blkid(dnode_t *dn, uint64_t blkid, dmu_tx_t *tx, boolean_t have_read)
1438 {
1439 uint64_t txgoff = tx->tx_txg & TXG_MASK;
1440 int epbs, new_nlevels;
1441 uint64_t sz;
1442
1443 ASSERT(blkid != DMU_BONUS_BLKID);
1444
1445 ASSERT(have_read ?
1446 RW_READ_HELD(&dn->dn_struct_rwlock) :
1447 RW_WRITE_HELD(&dn->dn_struct_rwlock));
1448
1449 /*
1450 * if we have a read-lock, check to see if we need to do any work
1451 * before upgrading to a write-lock.
1452 */
1453 if (have_read) {
1454 if (blkid <= dn->dn_maxblkid)
1455 return;
1456
1457 if (!rw_tryupgrade(&dn->dn_struct_rwlock)) {
1458 rw_exit(&dn->dn_struct_rwlock);
1459 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
1460 }
1461 }
1462
1463 if (blkid <= dn->dn_maxblkid)
1464 goto out;
1465
1466 dn->dn_maxblkid = blkid;
1467
1468 /*
1469 * Compute the number of levels necessary to support the new maxblkid.
1470 */
1471 new_nlevels = 1;
1472 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT;
1473 for (sz = dn->dn_nblkptr;
1474 sz <= blkid && sz >= dn->dn_nblkptr; sz <<= epbs)
1475 new_nlevels++;
1476
1477 if (new_nlevels > dn->dn_nlevels) {
1478 int old_nlevels = dn->dn_nlevels;
1479 dmu_buf_impl_t *db;
1480 list_t *list;
1481 dbuf_dirty_record_t *new, *dr, *dr_next;
1482
1483 dn->dn_nlevels = new_nlevels;
1484
1485 ASSERT3U(new_nlevels, >, dn->dn_next_nlevels[txgoff]);
1486 dn->dn_next_nlevels[txgoff] = new_nlevels;
1487
1488 /* dirty the left indirects */
1489 db = dbuf_hold_level(dn, old_nlevels, 0, FTAG);
1490 ASSERT(db != NULL);
1491 new = dbuf_dirty(db, tx);
1492 dbuf_rele(db, FTAG);
1493
1494 /* transfer the dirty records to the new indirect */
1495 mutex_enter(&dn->dn_mtx);
1496 mutex_enter(&new->dt.di.dr_mtx);
1497 list = &dn->dn_dirty_records[txgoff];
1498 for (dr = list_head(list); dr; dr = dr_next) {
1499 dr_next = list_next(&dn->dn_dirty_records[txgoff], dr);
1500 if (dr->dr_dbuf->db_level != new_nlevels-1 &&
1501 dr->dr_dbuf->db_blkid != DMU_BONUS_BLKID &&
1502 dr->dr_dbuf->db_blkid != DMU_SPILL_BLKID) {
1503 ASSERT(dr->dr_dbuf->db_level == old_nlevels-1);
1504 list_remove(&dn->dn_dirty_records[txgoff], dr);
1505 list_insert_tail(&new->dt.di.dr_children, dr);
1506 dr->dr_parent = new;
1507 }
1508 }
1509 mutex_exit(&new->dt.di.dr_mtx);
1510 mutex_exit(&dn->dn_mtx);
1511 }
1512
1513 out:
1514 if (have_read)
1515 rw_downgrade(&dn->dn_struct_rwlock);
1516 }
1517
1518 static void
dnode_dirty_l1(dnode_t * dn,uint64_t l1blkid,dmu_tx_t * tx)1519 dnode_dirty_l1(dnode_t *dn, uint64_t l1blkid, dmu_tx_t *tx)
1520 {
1521 dmu_buf_impl_t *db = dbuf_hold_level(dn, 1, l1blkid, FTAG);
1522 if (db != NULL) {
1523 dmu_buf_will_dirty(&db->db, tx);
1524 dbuf_rele(db, FTAG);
1525 }
1526 }
1527
1528 void
dnode_free_range(dnode_t * dn,uint64_t off,uint64_t len,dmu_tx_t * tx)1529 dnode_free_range(dnode_t *dn, uint64_t off, uint64_t len, dmu_tx_t *tx)
1530 {
1531 dmu_buf_impl_t *db;
1532 uint64_t blkoff, blkid, nblks;
1533 int blksz, blkshift, head, tail;
1534 int trunc = FALSE;
1535 int epbs;
1536
1537 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
1538 blksz = dn->dn_datablksz;
1539 blkshift = dn->dn_datablkshift;
1540 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT;
1541
1542 if (len == DMU_OBJECT_END) {
1543 len = UINT64_MAX - off;
1544 trunc = TRUE;
1545 }
1546
1547 /*
1548 * First, block align the region to free:
1549 */
1550 if (ISP2(blksz)) {
1551 head = P2NPHASE(off, blksz);
1552 blkoff = P2PHASE(off, blksz);
1553 if ((off >> blkshift) > dn->dn_maxblkid)
1554 goto out;
1555 } else {
1556 ASSERT(dn->dn_maxblkid == 0);
1557 if (off == 0 && len >= blksz) {
1558 /*
1559 * Freeing the whole block; fast-track this request.
1560 * Note that we won't dirty any indirect blocks,
1561 * which is fine because we will be freeing the entire
1562 * file and thus all indirect blocks will be freed
1563 * by free_children().
1564 */
1565 blkid = 0;
1566 nblks = 1;
1567 goto done;
1568 } else if (off >= blksz) {
1569 /* Freeing past end-of-data */
1570 goto out;
1571 } else {
1572 /* Freeing part of the block. */
1573 head = blksz - off;
1574 ASSERT3U(head, >, 0);
1575 }
1576 blkoff = off;
1577 }
1578 /* zero out any partial block data at the start of the range */
1579 if (head) {
1580 ASSERT3U(blkoff + head, ==, blksz);
1581 if (len < head)
1582 head = len;
1583 if (dbuf_hold_impl(dn, 0, dbuf_whichblock(dn, 0, off),
1584 TRUE, FALSE, FTAG, &db) == 0) {
1585 caddr_t data;
1586
1587 /* don't dirty if it isn't on disk and isn't dirty */
1588 if (db->db_last_dirty ||
1589 (db->db_blkptr && !BP_IS_HOLE(db->db_blkptr))) {
1590 rw_exit(&dn->dn_struct_rwlock);
1591 dmu_buf_will_dirty(&db->db, tx);
1592 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
1593 data = db->db.db_data;
1594 bzero(data + blkoff, head);
1595 }
1596 dbuf_rele(db, FTAG);
1597 }
1598 off += head;
1599 len -= head;
1600 }
1601
1602 /* If the range was less than one block, we're done */
1603 if (len == 0)
1604 goto out;
1605
1606 /* If the remaining range is past end of file, we're done */
1607 if ((off >> blkshift) > dn->dn_maxblkid)
1608 goto out;
1609
1610 ASSERT(ISP2(blksz));
1611 if (trunc)
1612 tail = 0;
1613 else
1614 tail = P2PHASE(len, blksz);
1615
1616 ASSERT0(P2PHASE(off, blksz));
1617 /* zero out any partial block data at the end of the range */
1618 if (tail) {
1619 if (len < tail)
1620 tail = len;
1621 if (dbuf_hold_impl(dn, 0, dbuf_whichblock(dn, 0, off+len),
1622 TRUE, FALSE, FTAG, &db) == 0) {
1623 /* don't dirty if not on disk and not dirty */
1624 if (db->db_last_dirty ||
1625 (db->db_blkptr && !BP_IS_HOLE(db->db_blkptr))) {
1626 rw_exit(&dn->dn_struct_rwlock);
1627 dmu_buf_will_dirty(&db->db, tx);
1628 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
1629 bzero(db->db.db_data, tail);
1630 }
1631 dbuf_rele(db, FTAG);
1632 }
1633 len -= tail;
1634 }
1635
1636 /* If the range did not include a full block, we are done */
1637 if (len == 0)
1638 goto out;
1639
1640 ASSERT(IS_P2ALIGNED(off, blksz));
1641 ASSERT(trunc || IS_P2ALIGNED(len, blksz));
1642 blkid = off >> blkshift;
1643 nblks = len >> blkshift;
1644 if (trunc)
1645 nblks += 1;
1646
1647 /*
1648 * Dirty all the indirect blocks in this range. Note that only
1649 * the first and last indirect blocks can actually be written
1650 * (if they were partially freed) -- they must be dirtied, even if
1651 * they do not exist on disk yet. The interior blocks will
1652 * be freed by free_children(), so they will not actually be written.
1653 * Even though these interior blocks will not be written, we
1654 * dirty them for two reasons:
1655 *
1656 * - It ensures that the indirect blocks remain in memory until
1657 * syncing context. (They have already been prefetched by
1658 * dmu_tx_hold_free(), so we don't have to worry about reading
1659 * them serially here.)
1660 *
1661 * - The dirty space accounting will put pressure on the txg sync
1662 * mechanism to begin syncing, and to delay transactions if there
1663 * is a large amount of freeing. Even though these indirect
1664 * blocks will not be written, we could need to write the same
1665 * amount of space if we copy the freed BPs into deadlists.
1666 */
1667 if (dn->dn_nlevels > 1) {
1668 uint64_t first, last;
1669
1670 first = blkid >> epbs;
1671 dnode_dirty_l1(dn, first, tx);
1672 if (trunc)
1673 last = dn->dn_maxblkid >> epbs;
1674 else
1675 last = (blkid + nblks - 1) >> epbs;
1676 if (last != first)
1677 dnode_dirty_l1(dn, last, tx);
1678
1679 int shift = dn->dn_datablkshift + dn->dn_indblkshift -
1680 SPA_BLKPTRSHIFT;
1681 for (uint64_t i = first + 1; i < last; i++) {
1682 /*
1683 * Set i to the blockid of the next non-hole
1684 * level-1 indirect block at or after i. Note
1685 * that dnode_next_offset() operates in terms of
1686 * level-0-equivalent bytes.
1687 */
1688 uint64_t ibyte = i << shift;
1689 int err = dnode_next_offset(dn, DNODE_FIND_HAVELOCK,
1690 &ibyte, 2, 1, 0);
1691 i = ibyte >> shift;
1692 if (i >= last)
1693 break;
1694
1695 /*
1696 * Normally we should not see an error, either
1697 * from dnode_next_offset() or dbuf_hold_level()
1698 * (except for ESRCH from dnode_next_offset).
1699 * If there is an i/o error, then when we read
1700 * this block in syncing context, it will use
1701 * ZIO_FLAG_MUSTSUCCEED, and thus hang/panic according
1702 * to the "failmode" property. dnode_next_offset()
1703 * doesn't have a flag to indicate MUSTSUCCEED.
1704 */
1705 if (err != 0)
1706 break;
1707
1708 dnode_dirty_l1(dn, i, tx);
1709 }
1710 }
1711
1712 done:
1713 /*
1714 * Add this range to the dnode range list.
1715 * We will finish up this free operation in the syncing phase.
1716 */
1717 mutex_enter(&dn->dn_mtx);
1718 int txgoff = tx->tx_txg & TXG_MASK;
1719 if (dn->dn_free_ranges[txgoff] == NULL) {
1720 dn->dn_free_ranges[txgoff] =
1721 range_tree_create(NULL, NULL, &dn->dn_mtx);
1722 }
1723 range_tree_clear(dn->dn_free_ranges[txgoff], blkid, nblks);
1724 range_tree_add(dn->dn_free_ranges[txgoff], blkid, nblks);
1725 dprintf_dnode(dn, "blkid=%llu nblks=%llu txg=%llu\n",
1726 blkid, nblks, tx->tx_txg);
1727 mutex_exit(&dn->dn_mtx);
1728
1729 dbuf_free_range(dn, blkid, blkid + nblks - 1, tx);
1730 dnode_setdirty(dn, tx);
1731 out:
1732
1733 rw_exit(&dn->dn_struct_rwlock);
1734 }
1735
1736 static boolean_t
dnode_spill_freed(dnode_t * dn)1737 dnode_spill_freed(dnode_t *dn)
1738 {
1739 int i;
1740
1741 mutex_enter(&dn->dn_mtx);
1742 for (i = 0; i < TXG_SIZE; i++) {
1743 if (dn->dn_rm_spillblk[i] == DN_KILL_SPILLBLK)
1744 break;
1745 }
1746 mutex_exit(&dn->dn_mtx);
1747 return (i < TXG_SIZE);
1748 }
1749
1750 /* return TRUE if this blkid was freed in a recent txg, or FALSE if it wasn't */
1751 uint64_t
dnode_block_freed(dnode_t * dn,uint64_t blkid)1752 dnode_block_freed(dnode_t *dn, uint64_t blkid)
1753 {
1754 void *dp = spa_get_dsl(dn->dn_objset->os_spa);
1755 int i;
1756
1757 if (blkid == DMU_BONUS_BLKID)
1758 return (FALSE);
1759
1760 /*
1761 * If we're in the process of opening the pool, dp will not be
1762 * set yet, but there shouldn't be anything dirty.
1763 */
1764 if (dp == NULL)
1765 return (FALSE);
1766
1767 if (dn->dn_free_txg)
1768 return (TRUE);
1769
1770 if (blkid == DMU_SPILL_BLKID)
1771 return (dnode_spill_freed(dn));
1772
1773 mutex_enter(&dn->dn_mtx);
1774 for (i = 0; i < TXG_SIZE; i++) {
1775 if (dn->dn_free_ranges[i] != NULL &&
1776 range_tree_contains(dn->dn_free_ranges[i], blkid, 1))
1777 break;
1778 }
1779 mutex_exit(&dn->dn_mtx);
1780 return (i < TXG_SIZE);
1781 }
1782
1783 /* call from syncing context when we actually write/free space for this dnode */
1784 void
dnode_diduse_space(dnode_t * dn,int64_t delta)1785 dnode_diduse_space(dnode_t *dn, int64_t delta)
1786 {
1787 uint64_t space;
1788 dprintf_dnode(dn, "dn=%p dnp=%p used=%llu delta=%lld\n",
1789 dn, dn->dn_phys,
1790 (u_longlong_t)dn->dn_phys->dn_used,
1791 (longlong_t)delta);
1792
1793 mutex_enter(&dn->dn_mtx);
1794 space = DN_USED_BYTES(dn->dn_phys);
1795 if (delta > 0) {
1796 ASSERT3U(space + delta, >=, space); /* no overflow */
1797 } else {
1798 ASSERT3U(space, >=, -delta); /* no underflow */
1799 }
1800 space += delta;
1801 if (spa_version(dn->dn_objset->os_spa) < SPA_VERSION_DNODE_BYTES) {
1802 ASSERT((dn->dn_phys->dn_flags & DNODE_FLAG_USED_BYTES) == 0);
1803 ASSERT0(P2PHASE(space, 1<<DEV_BSHIFT));
1804 dn->dn_phys->dn_used = space >> DEV_BSHIFT;
1805 } else {
1806 dn->dn_phys->dn_used = space;
1807 dn->dn_phys->dn_flags |= DNODE_FLAG_USED_BYTES;
1808 }
1809 mutex_exit(&dn->dn_mtx);
1810 }
1811
1812 /*
1813 * Call when we think we're going to write/free space in open context to track
1814 * the amount of memory in use by the currently open txg.
1815 */
1816 void
dnode_willuse_space(dnode_t * dn,int64_t space,dmu_tx_t * tx)1817 dnode_willuse_space(dnode_t *dn, int64_t space, dmu_tx_t *tx)
1818 {
1819 objset_t *os = dn->dn_objset;
1820 dsl_dataset_t *ds = os->os_dsl_dataset;
1821 int64_t aspace = spa_get_asize(os->os_spa, space);
1822
1823 if (ds != NULL) {
1824 dsl_dir_willuse_space(ds->ds_dir, aspace, tx);
1825 dsl_pool_dirty_space(dmu_tx_pool(tx), space, tx);
1826 }
1827
1828 dmu_tx_willuse_space(tx, aspace);
1829 }
1830
1831 /*
1832 * Scans a block at the indicated "level" looking for a hole or data,
1833 * depending on 'flags'.
1834 *
1835 * If level > 0, then we are scanning an indirect block looking at its
1836 * pointers. If level == 0, then we are looking at a block of dnodes.
1837 *
1838 * If we don't find what we are looking for in the block, we return ESRCH.
1839 * Otherwise, return with *offset pointing to the beginning (if searching
1840 * forwards) or end (if searching backwards) of the range covered by the
1841 * block pointer we matched on (or dnode).
1842 *
1843 * The basic search algorithm used below by dnode_next_offset() is to
1844 * use this function to search up the block tree (widen the search) until
1845 * we find something (i.e., we don't return ESRCH) and then search back
1846 * down the tree (narrow the search) until we reach our original search
1847 * level.
1848 */
1849 static int
dnode_next_offset_level(dnode_t * dn,int flags,uint64_t * offset,int lvl,uint64_t blkfill,uint64_t txg)1850 dnode_next_offset_level(dnode_t *dn, int flags, uint64_t *offset,
1851 int lvl, uint64_t blkfill, uint64_t txg)
1852 {
1853 dmu_buf_impl_t *db = NULL;
1854 void *data = NULL;
1855 uint64_t epbs = dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT;
1856 uint64_t epb = 1ULL << epbs;
1857 uint64_t minfill, maxfill;
1858 boolean_t hole;
1859 int i, inc, error, span;
1860
1861 dprintf("probing object %llu offset %llx level %d of %u\n",
1862 dn->dn_object, *offset, lvl, dn->dn_phys->dn_nlevels);
1863
1864 hole = ((flags & DNODE_FIND_HOLE) != 0);
1865 inc = (flags & DNODE_FIND_BACKWARDS) ? -1 : 1;
1866 ASSERT(txg == 0 || !hole);
1867
1868 if (lvl == dn->dn_phys->dn_nlevels) {
1869 error = 0;
1870 epb = dn->dn_phys->dn_nblkptr;
1871 data = dn->dn_phys->dn_blkptr;
1872 } else {
1873 uint64_t blkid = dbuf_whichblock(dn, lvl, *offset);
1874 error = dbuf_hold_impl(dn, lvl, blkid, TRUE, FALSE, FTAG, &db);
1875 if (error) {
1876 if (error != ENOENT)
1877 return (error);
1878 if (hole)
1879 return (0);
1880 /*
1881 * This can only happen when we are searching up
1882 * the block tree for data. We don't really need to
1883 * adjust the offset, as we will just end up looking
1884 * at the pointer to this block in its parent, and its
1885 * going to be unallocated, so we will skip over it.
1886 */
1887 return (SET_ERROR(ESRCH));
1888 }
1889 error = dbuf_read(db, NULL, DB_RF_CANFAIL | DB_RF_HAVESTRUCT);
1890 if (error) {
1891 dbuf_rele(db, FTAG);
1892 return (error);
1893 }
1894 data = db->db.db_data;
1895 }
1896
1897
1898 if (db != NULL && txg != 0 && (db->db_blkptr == NULL ||
1899 db->db_blkptr->blk_birth <= txg ||
1900 BP_IS_HOLE(db->db_blkptr))) {
1901 /*
1902 * This can only happen when we are searching up the tree
1903 * and these conditions mean that we need to keep climbing.
1904 */
1905 error = SET_ERROR(ESRCH);
1906 } else if (lvl == 0) {
1907 dnode_phys_t *dnp = data;
1908 span = DNODE_SHIFT;
1909 ASSERT(dn->dn_type == DMU_OT_DNODE);
1910
1911 for (i = (*offset >> span) & (blkfill - 1);
1912 i >= 0 && i < blkfill; i += inc) {
1913 if ((dnp[i].dn_type == DMU_OT_NONE) == hole)
1914 break;
1915 *offset += (1ULL << span) * inc;
1916 }
1917 if (i < 0 || i == blkfill)
1918 error = SET_ERROR(ESRCH);
1919 } else {
1920 blkptr_t *bp = data;
1921 uint64_t start = *offset;
1922 span = (lvl - 1) * epbs + dn->dn_datablkshift;
1923 minfill = 0;
1924 maxfill = blkfill << ((lvl - 1) * epbs);
1925
1926 if (hole)
1927 maxfill--;
1928 else
1929 minfill++;
1930
1931 *offset = *offset >> span;
1932 for (i = BF64_GET(*offset, 0, epbs);
1933 i >= 0 && i < epb; i += inc) {
1934 if (BP_GET_FILL(&bp[i]) >= minfill &&
1935 BP_GET_FILL(&bp[i]) <= maxfill &&
1936 (hole || bp[i].blk_birth > txg))
1937 break;
1938 if (inc > 0 || *offset > 0)
1939 *offset += inc;
1940 }
1941 *offset = *offset << span;
1942 if (inc < 0) {
1943 /* traversing backwards; position offset at the end */
1944 ASSERT3U(*offset, <=, start);
1945 *offset = MIN(*offset + (1ULL << span) - 1, start);
1946 } else if (*offset < start) {
1947 *offset = start;
1948 }
1949 if (i < 0 || i >= epb)
1950 error = SET_ERROR(ESRCH);
1951 }
1952
1953 if (db)
1954 dbuf_rele(db, FTAG);
1955
1956 return (error);
1957 }
1958
1959 /*
1960 * Find the next hole, data, or sparse region at or after *offset.
1961 * The value 'blkfill' tells us how many items we expect to find
1962 * in an L0 data block; this value is 1 for normal objects,
1963 * DNODES_PER_BLOCK for the meta dnode, and some fraction of
1964 * DNODES_PER_BLOCK when searching for sparse regions thereof.
1965 *
1966 * Examples:
1967 *
1968 * dnode_next_offset(dn, flags, offset, 1, 1, 0);
1969 * Finds the next/previous hole/data in a file.
1970 * Used in dmu_offset_next().
1971 *
1972 * dnode_next_offset(mdn, flags, offset, 0, DNODES_PER_BLOCK, txg);
1973 * Finds the next free/allocated dnode an objset's meta-dnode.
1974 * Only finds objects that have new contents since txg (ie.
1975 * bonus buffer changes and content removal are ignored).
1976 * Used in dmu_object_next().
1977 *
1978 * dnode_next_offset(mdn, DNODE_FIND_HOLE, offset, 2, DNODES_PER_BLOCK >> 2, 0);
1979 * Finds the next L2 meta-dnode bp that's at most 1/4 full.
1980 * Used in dmu_object_alloc().
1981 */
1982 int
dnode_next_offset(dnode_t * dn,int flags,uint64_t * offset,int minlvl,uint64_t blkfill,uint64_t txg)1983 dnode_next_offset(dnode_t *dn, int flags, uint64_t *offset,
1984 int minlvl, uint64_t blkfill, uint64_t txg)
1985 {
1986 uint64_t initial_offset = *offset;
1987 int lvl, maxlvl;
1988 int error = 0;
1989
1990 if (!(flags & DNODE_FIND_HAVELOCK))
1991 rw_enter(&dn->dn_struct_rwlock, RW_READER);
1992
1993 if (dn->dn_phys->dn_nlevels == 0) {
1994 error = SET_ERROR(ESRCH);
1995 goto out;
1996 }
1997
1998 if (dn->dn_datablkshift == 0) {
1999 if (*offset < dn->dn_datablksz) {
2000 if (flags & DNODE_FIND_HOLE)
2001 *offset = dn->dn_datablksz;
2002 } else {
2003 error = SET_ERROR(ESRCH);
2004 }
2005 goto out;
2006 }
2007
2008 maxlvl = dn->dn_phys->dn_nlevels;
2009
2010 for (lvl = minlvl; lvl <= maxlvl; lvl++) {
2011 error = dnode_next_offset_level(dn,
2012 flags, offset, lvl, blkfill, txg);
2013 if (error != ESRCH)
2014 break;
2015 }
2016
2017 while (error == 0 && --lvl >= minlvl) {
2018 error = dnode_next_offset_level(dn,
2019 flags, offset, lvl, blkfill, txg);
2020 }
2021
2022 /*
2023 * There's always a "virtual hole" at the end of the object, even
2024 * if all BP's which physically exist are non-holes.
2025 */
2026 if ((flags & DNODE_FIND_HOLE) && error == ESRCH && txg == 0 &&
2027 minlvl == 1 && blkfill == 1 && !(flags & DNODE_FIND_BACKWARDS)) {
2028 error = 0;
2029 }
2030
2031 if (error == 0 && (flags & DNODE_FIND_BACKWARDS ?
2032 initial_offset < *offset : initial_offset > *offset))
2033 error = SET_ERROR(ESRCH);
2034 out:
2035 if (!(flags & DNODE_FIND_HAVELOCK))
2036 rw_exit(&dn->dn_struct_rwlock);
2037
2038 return (error);
2039 }
2040