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) 2013 by Delphix. All rights reserved.
24 */
25
26 #include <sys/zfs_context.h>
27 #include <sys/dbuf.h>
28 #include <sys/dnode.h>
29 #include <sys/dmu.h>
30 #include <sys/dmu_impl.h>
31 #include <sys/dmu_tx.h>
32 #include <sys/dmu_objset.h>
33 #include <sys/dsl_dir.h>
34 #include <sys/dsl_dataset.h>
35 #include <sys/spa.h>
36 #include <sys/zio.h>
37 #include <sys/dmu_zfetch.h>
38
39 static int free_range_compar(const void *node1, const void *node2);
40
41 static kmem_cache_t *dnode_cache;
42 /*
43 * Define DNODE_STATS to turn on statistic gathering. By default, it is only
44 * turned on when DEBUG is also defined.
45 */
46 #ifdef DEBUG
47 #define DNODE_STATS
48 #endif /* DEBUG */
49
50 #ifdef DNODE_STATS
51 #define DNODE_STAT_ADD(stat) ((stat)++)
52 #else
53 #define DNODE_STAT_ADD(stat) /* nothing */
54 #endif /* DNODE_STATS */
55
56 static dnode_phys_t dnode_phys_zero;
57
58 int zfs_default_bs = SPA_MINBLOCKSHIFT;
59 int zfs_default_ibs = DN_MAX_INDBLKSHIFT;
60
61 static kmem_cbrc_t dnode_move(void *, void *, size_t, void *);
62
63 /* ARGSUSED */
64 static int
65 dnode_cons(void *arg, void *unused, int kmflag)
66 {
67 dnode_t *dn = arg;
68 int i;
69
70 rw_init(&dn->dn_struct_rwlock, NULL, RW_DEFAULT, NULL);
71 mutex_init(&dn->dn_mtx, NULL, MUTEX_DEFAULT, NULL);
72 mutex_init(&dn->dn_dbufs_mtx, NULL, MUTEX_DEFAULT, NULL);
73 cv_init(&dn->dn_notxholds, NULL, CV_DEFAULT, NULL);
74
75 /*
76 * Every dbuf has a reference, and dropping a tracked reference is
77 * O(number of references), so don't track dn_holds.
78 */
79 refcount_create_untracked(&dn->dn_holds);
80 refcount_create(&dn->dn_tx_holds);
81 list_link_init(&dn->dn_link);
82
83 bzero(&dn->dn_next_nblkptr[0], sizeof (dn->dn_next_nblkptr));
84 bzero(&dn->dn_next_nlevels[0], sizeof (dn->dn_next_nlevels));
85 bzero(&dn->dn_next_indblkshift[0], sizeof (dn->dn_next_indblkshift));
86 bzero(&dn->dn_next_bonustype[0], sizeof (dn->dn_next_bonustype));
87 bzero(&dn->dn_rm_spillblk[0], sizeof (dn->dn_rm_spillblk));
88 bzero(&dn->dn_next_bonuslen[0], sizeof (dn->dn_next_bonuslen));
89 bzero(&dn->dn_next_blksz[0], sizeof (dn->dn_next_blksz));
90
91 for (i = 0; i < TXG_SIZE; i++) {
92 list_link_init(&dn->dn_dirty_link[i]);
93 avl_create(&dn->dn_ranges[i], free_range_compar,
94 sizeof (free_range_t),
95 offsetof(struct free_range, fr_node));
96 list_create(&dn->dn_dirty_records[i],
97 sizeof (dbuf_dirty_record_t),
98 offsetof(dbuf_dirty_record_t, dr_dirty_node));
99 }
100
101 dn->dn_allocated_txg = 0;
102 dn->dn_free_txg = 0;
103 dn->dn_assigned_txg = 0;
104 dn->dn_dirtyctx = 0;
105 dn->dn_dirtyctx_firstset = NULL;
106 dn->dn_bonus = NULL;
107 dn->dn_have_spill = B_FALSE;
108 dn->dn_zio = NULL;
109 dn->dn_oldused = 0;
110 dn->dn_oldflags = 0;
111 dn->dn_olduid = 0;
112 dn->dn_oldgid = 0;
113 dn->dn_newuid = 0;
114 dn->dn_newgid = 0;
115 dn->dn_id_flags = 0;
116
117 dn->dn_dbufs_count = 0;
118 dn->dn_unlisted_l0_blkid = 0;
119 list_create(&dn->dn_dbufs, sizeof (dmu_buf_impl_t),
120 offsetof(dmu_buf_impl_t, db_link));
121
122 dn->dn_moved = 0;
123 return (0);
124 }
125
126 /* ARGSUSED */
127 static void
128 dnode_dest(void *arg, void *unused)
129 {
130 int i;
131 dnode_t *dn = arg;
132
133 rw_destroy(&dn->dn_struct_rwlock);
134 mutex_destroy(&dn->dn_mtx);
135 mutex_destroy(&dn->dn_dbufs_mtx);
136 cv_destroy(&dn->dn_notxholds);
137 refcount_destroy(&dn->dn_holds);
138 refcount_destroy(&dn->dn_tx_holds);
139 ASSERT(!list_link_active(&dn->dn_link));
140
141 for (i = 0; i < TXG_SIZE; i++) {
142 ASSERT(!list_link_active(&dn->dn_dirty_link[i]));
143 avl_destroy(&dn->dn_ranges[i]);
144 list_destroy(&dn->dn_dirty_records[i]);
145 ASSERT0(dn->dn_next_nblkptr[i]);
146 ASSERT0(dn->dn_next_nlevels[i]);
147 ASSERT0(dn->dn_next_indblkshift[i]);
148 ASSERT0(dn->dn_next_bonustype[i]);
149 ASSERT0(dn->dn_rm_spillblk[i]);
150 ASSERT0(dn->dn_next_bonuslen[i]);
151 ASSERT0(dn->dn_next_blksz[i]);
152 }
153
154 ASSERT0(dn->dn_allocated_txg);
155 ASSERT0(dn->dn_free_txg);
156 ASSERT0(dn->dn_assigned_txg);
157 ASSERT0(dn->dn_dirtyctx);
158 ASSERT3P(dn->dn_dirtyctx_firstset, ==, NULL);
159 ASSERT3P(dn->dn_bonus, ==, NULL);
160 ASSERT(!dn->dn_have_spill);
161 ASSERT3P(dn->dn_zio, ==, NULL);
162 ASSERT0(dn->dn_oldused);
163 ASSERT0(dn->dn_oldflags);
164 ASSERT0(dn->dn_olduid);
165 ASSERT0(dn->dn_oldgid);
166 ASSERT0(dn->dn_newuid);
167 ASSERT0(dn->dn_newgid);
168 ASSERT0(dn->dn_id_flags);
169
170 ASSERT0(dn->dn_dbufs_count);
171 ASSERT0(dn->dn_unlisted_l0_blkid);
172 list_destroy(&dn->dn_dbufs);
173 }
174
175 void
176 dnode_init(void)
177 {
178 ASSERT(dnode_cache == NULL);
179 dnode_cache = kmem_cache_create("dnode_t",
180 sizeof (dnode_t),
181 0, dnode_cons, dnode_dest, NULL, NULL, NULL, 0);
182 kmem_cache_set_move(dnode_cache, dnode_move);
183 }
184
185 void
186 dnode_fini(void)
187 {
188 kmem_cache_destroy(dnode_cache);
189 dnode_cache = NULL;
190 }
191
192
193 #ifdef ZFS_DEBUG
194 void
195 dnode_verify(dnode_t *dn)
196 {
197 int drop_struct_lock = FALSE;
198
199 ASSERT(dn->dn_phys);
200 ASSERT(dn->dn_objset);
201 ASSERT(dn->dn_handle->dnh_dnode == dn);
202
203 ASSERT(DMU_OT_IS_VALID(dn->dn_phys->dn_type));
204
205 if (!(zfs_flags & ZFS_DEBUG_DNODE_VERIFY))
206 return;
207
208 if (!RW_WRITE_HELD(&dn->dn_struct_rwlock)) {
209 rw_enter(&dn->dn_struct_rwlock, RW_READER);
210 drop_struct_lock = TRUE;
211 }
212 if (dn->dn_phys->dn_type != DMU_OT_NONE || dn->dn_allocated_txg != 0) {
213 int i;
214 ASSERT3U(dn->dn_indblkshift, >=, 0);
215 ASSERT3U(dn->dn_indblkshift, <=, SPA_MAXBLOCKSHIFT);
216 if (dn->dn_datablkshift) {
217 ASSERT3U(dn->dn_datablkshift, >=, SPA_MINBLOCKSHIFT);
218 ASSERT3U(dn->dn_datablkshift, <=, SPA_MAXBLOCKSHIFT);
219 ASSERT3U(1<<dn->dn_datablkshift, ==, dn->dn_datablksz);
220 }
221 ASSERT3U(dn->dn_nlevels, <=, 30);
222 ASSERT(DMU_OT_IS_VALID(dn->dn_type));
223 ASSERT3U(dn->dn_nblkptr, >=, 1);
224 ASSERT3U(dn->dn_nblkptr, <=, DN_MAX_NBLKPTR);
225 ASSERT3U(dn->dn_bonuslen, <=, DN_MAX_BONUSLEN);
226 ASSERT3U(dn->dn_datablksz, ==,
227 dn->dn_datablkszsec << SPA_MINBLOCKSHIFT);
228 ASSERT3U(ISP2(dn->dn_datablksz), ==, dn->dn_datablkshift != 0);
229 ASSERT3U((dn->dn_nblkptr - 1) * sizeof (blkptr_t) +
230 dn->dn_bonuslen, <=, DN_MAX_BONUSLEN);
231 for (i = 0; i < TXG_SIZE; i++) {
232 ASSERT3U(dn->dn_next_nlevels[i], <=, dn->dn_nlevels);
233 }
234 }
235 if (dn->dn_phys->dn_type != DMU_OT_NONE)
236 ASSERT3U(dn->dn_phys->dn_nlevels, <=, dn->dn_nlevels);
237 ASSERT(DMU_OBJECT_IS_SPECIAL(dn->dn_object) || dn->dn_dbuf != NULL);
238 if (dn->dn_dbuf != NULL) {
239 ASSERT3P(dn->dn_phys, ==,
240 (dnode_phys_t *)dn->dn_dbuf->db.db_data +
241 (dn->dn_object % (dn->dn_dbuf->db.db_size >> DNODE_SHIFT)));
242 }
243 if (drop_struct_lock)
244 rw_exit(&dn->dn_struct_rwlock);
245 }
246 #endif
247
248 void
249 dnode_byteswap(dnode_phys_t *dnp)
250 {
251 uint64_t *buf64 = (void*)&dnp->dn_blkptr;
252 int i;
253
254 if (dnp->dn_type == DMU_OT_NONE) {
255 bzero(dnp, sizeof (dnode_phys_t));
256 return;
257 }
258
259 dnp->dn_datablkszsec = BSWAP_16(dnp->dn_datablkszsec);
260 dnp->dn_bonuslen = BSWAP_16(dnp->dn_bonuslen);
261 dnp->dn_maxblkid = BSWAP_64(dnp->dn_maxblkid);
262 dnp->dn_used = BSWAP_64(dnp->dn_used);
263
264 /*
265 * dn_nblkptr is only one byte, so it's OK to read it in either
266 * byte order. We can't read dn_bouslen.
267 */
268 ASSERT(dnp->dn_indblkshift <= SPA_MAXBLOCKSHIFT);
269 ASSERT(dnp->dn_nblkptr <= DN_MAX_NBLKPTR);
270 for (i = 0; i < dnp->dn_nblkptr * sizeof (blkptr_t)/8; i++)
271 buf64[i] = BSWAP_64(buf64[i]);
272
273 /*
274 * OK to check dn_bonuslen for zero, because it won't matter if
275 * we have the wrong byte order. This is necessary because the
276 * dnode dnode is smaller than a regular dnode.
277 */
278 if (dnp->dn_bonuslen != 0) {
279 /*
280 * Note that the bonus length calculated here may be
281 * longer than the actual bonus buffer. This is because
282 * we always put the bonus buffer after the last block
283 * pointer (instead of packing it against the end of the
284 * dnode buffer).
285 */
286 int off = (dnp->dn_nblkptr-1) * sizeof (blkptr_t);
287 size_t len = DN_MAX_BONUSLEN - off;
288 ASSERT(DMU_OT_IS_VALID(dnp->dn_bonustype));
289 dmu_object_byteswap_t byteswap =
290 DMU_OT_BYTESWAP(dnp->dn_bonustype);
291 dmu_ot_byteswap[byteswap].ob_func(dnp->dn_bonus + off, len);
292 }
293
294 /* Swap SPILL block if we have one */
295 if (dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR)
296 byteswap_uint64_array(&dnp->dn_spill, sizeof (blkptr_t));
297
298 }
299
300 void
301 dnode_buf_byteswap(void *vbuf, size_t size)
302 {
303 dnode_phys_t *buf = vbuf;
304 int i;
305
306 ASSERT3U(sizeof (dnode_phys_t), ==, (1<<DNODE_SHIFT));
307 ASSERT((size & (sizeof (dnode_phys_t)-1)) == 0);
308
309 size >>= DNODE_SHIFT;
310 for (i = 0; i < size; i++) {
311 dnode_byteswap(buf);
312 buf++;
313 }
314 }
315
316 static int
317 free_range_compar(const void *node1, const void *node2)
318 {
319 const free_range_t *rp1 = node1;
320 const free_range_t *rp2 = node2;
321
322 if (rp1->fr_blkid < rp2->fr_blkid)
323 return (-1);
324 else if (rp1->fr_blkid > rp2->fr_blkid)
325 return (1);
326 else return (0);
327 }
328
329 void
330 dnode_setbonuslen(dnode_t *dn, int newsize, dmu_tx_t *tx)
331 {
332 ASSERT3U(refcount_count(&dn->dn_holds), >=, 1);
333
334 dnode_setdirty(dn, tx);
335 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
336 ASSERT3U(newsize, <=, DN_MAX_BONUSLEN -
337 (dn->dn_nblkptr-1) * sizeof (blkptr_t));
338 dn->dn_bonuslen = newsize;
339 if (newsize == 0)
340 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = DN_ZERO_BONUSLEN;
341 else
342 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = dn->dn_bonuslen;
343 rw_exit(&dn->dn_struct_rwlock);
344 }
345
346 void
347 dnode_setbonus_type(dnode_t *dn, dmu_object_type_t newtype, dmu_tx_t *tx)
348 {
349 ASSERT3U(refcount_count(&dn->dn_holds), >=, 1);
350 dnode_setdirty(dn, tx);
351 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
352 dn->dn_bonustype = newtype;
353 dn->dn_next_bonustype[tx->tx_txg & TXG_MASK] = dn->dn_bonustype;
354 rw_exit(&dn->dn_struct_rwlock);
355 }
356
357 void
358 dnode_rm_spill(dnode_t *dn, dmu_tx_t *tx)
359 {
360 ASSERT3U(refcount_count(&dn->dn_holds), >=, 1);
361 ASSERT(RW_WRITE_HELD(&dn->dn_struct_rwlock));
362 dnode_setdirty(dn, tx);
363 dn->dn_rm_spillblk[tx->tx_txg&TXG_MASK] = DN_KILL_SPILLBLK;
364 dn->dn_have_spill = B_FALSE;
365 }
366
367 static void
368 dnode_setdblksz(dnode_t *dn, int size)
369 {
370 ASSERT0(P2PHASE(size, SPA_MINBLOCKSIZE));
371 ASSERT3U(size, <=, SPA_MAXBLOCKSIZE);
372 ASSERT3U(size, >=, SPA_MINBLOCKSIZE);
373 ASSERT3U(size >> SPA_MINBLOCKSHIFT, <,
374 1<<(sizeof (dn->dn_phys->dn_datablkszsec) * 8));
375 dn->dn_datablksz = size;
376 dn->dn_datablkszsec = size >> SPA_MINBLOCKSHIFT;
377 dn->dn_datablkshift = ISP2(size) ? highbit(size - 1) : 0;
378 }
379
380 static dnode_t *
381 dnode_create(objset_t *os, dnode_phys_t *dnp, dmu_buf_impl_t *db,
382 uint64_t object, dnode_handle_t *dnh)
383 {
384 dnode_t *dn = kmem_cache_alloc(dnode_cache, KM_SLEEP);
385
386 ASSERT(!POINTER_IS_VALID(dn->dn_objset));
387 dn->dn_moved = 0;
388
389 /*
390 * Defer setting dn_objset until the dnode is ready to be a candidate
391 * for the dnode_move() callback.
392 */
393 dn->dn_object = object;
394 dn->dn_dbuf = db;
395 dn->dn_handle = dnh;
396 dn->dn_phys = dnp;
397
398 if (dnp->dn_datablkszsec) {
399 dnode_setdblksz(dn, dnp->dn_datablkszsec << SPA_MINBLOCKSHIFT);
400 } else {
401 dn->dn_datablksz = 0;
402 dn->dn_datablkszsec = 0;
403 dn->dn_datablkshift = 0;
404 }
405 dn->dn_indblkshift = dnp->dn_indblkshift;
406 dn->dn_nlevels = dnp->dn_nlevels;
407 dn->dn_type = dnp->dn_type;
408 dn->dn_nblkptr = dnp->dn_nblkptr;
409 dn->dn_checksum = dnp->dn_checksum;
410 dn->dn_compress = dnp->dn_compress;
411 dn->dn_bonustype = dnp->dn_bonustype;
412 dn->dn_bonuslen = dnp->dn_bonuslen;
413 dn->dn_maxblkid = dnp->dn_maxblkid;
414 dn->dn_have_spill = ((dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) != 0);
415 dn->dn_id_flags = 0;
416
417 dmu_zfetch_init(&dn->dn_zfetch, dn);
418
419 ASSERT(DMU_OT_IS_VALID(dn->dn_phys->dn_type));
420
421 mutex_enter(&os->os_lock);
422 list_insert_head(&os->os_dnodes, dn);
423 membar_producer();
424 /*
425 * Everything else must be valid before assigning dn_objset makes the
426 * dnode eligible for dnode_move().
427 */
428 dn->dn_objset = os;
429 mutex_exit(&os->os_lock);
430
431 arc_space_consume(sizeof (dnode_t), ARC_SPACE_OTHER);
432 return (dn);
433 }
434
435 /*
436 * Caller must be holding the dnode handle, which is released upon return.
437 */
438 static void
439 dnode_destroy(dnode_t *dn)
440 {
441 objset_t *os = dn->dn_objset;
442
443 ASSERT((dn->dn_id_flags & DN_ID_NEW_EXIST) == 0);
444
445 mutex_enter(&os->os_lock);
446 POINTER_INVALIDATE(&dn->dn_objset);
447 list_remove(&os->os_dnodes, dn);
448 mutex_exit(&os->os_lock);
449
450 /* the dnode can no longer move, so we can release the handle */
451 zrl_remove(&dn->dn_handle->dnh_zrlock);
452
453 dn->dn_allocated_txg = 0;
454 dn->dn_free_txg = 0;
455 dn->dn_assigned_txg = 0;
456
457 dn->dn_dirtyctx = 0;
458 if (dn->dn_dirtyctx_firstset != NULL) {
459 kmem_free(dn->dn_dirtyctx_firstset, 1);
460 dn->dn_dirtyctx_firstset = NULL;
461 }
462 if (dn->dn_bonus != NULL) {
463 mutex_enter(&dn->dn_bonus->db_mtx);
464 dbuf_evict(dn->dn_bonus);
465 dn->dn_bonus = NULL;
466 }
467 dn->dn_zio = NULL;
468
469 dn->dn_have_spill = B_FALSE;
470 dn->dn_oldused = 0;
471 dn->dn_oldflags = 0;
472 dn->dn_olduid = 0;
473 dn->dn_oldgid = 0;
474 dn->dn_newuid = 0;
475 dn->dn_newgid = 0;
476 dn->dn_id_flags = 0;
477 dn->dn_unlisted_l0_blkid = 0;
478
479 dmu_zfetch_rele(&dn->dn_zfetch);
480 kmem_cache_free(dnode_cache, dn);
481 arc_space_return(sizeof (dnode_t), ARC_SPACE_OTHER);
482 }
483
484 void
485 dnode_allocate(dnode_t *dn, dmu_object_type_t ot, int blocksize, int ibs,
486 dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx)
487 {
488 int i;
489
490 if (blocksize == 0)
491 blocksize = 1 << zfs_default_bs;
492 else if (blocksize > SPA_MAXBLOCKSIZE)
493 blocksize = SPA_MAXBLOCKSIZE;
494 else
495 blocksize = P2ROUNDUP(blocksize, SPA_MINBLOCKSIZE);
496
497 if (ibs == 0)
498 ibs = zfs_default_ibs;
499
500 ibs = MIN(MAX(ibs, DN_MIN_INDBLKSHIFT), DN_MAX_INDBLKSHIFT);
501
502 dprintf("os=%p obj=%llu txg=%llu blocksize=%d ibs=%d\n", dn->dn_objset,
503 dn->dn_object, tx->tx_txg, blocksize, ibs);
504
505 ASSERT(dn->dn_type == DMU_OT_NONE);
506 ASSERT(bcmp(dn->dn_phys, &dnode_phys_zero, sizeof (dnode_phys_t)) == 0);
507 ASSERT(dn->dn_phys->dn_type == DMU_OT_NONE);
508 ASSERT(ot != DMU_OT_NONE);
509 ASSERT(DMU_OT_IS_VALID(ot));
510 ASSERT((bonustype == DMU_OT_NONE && bonuslen == 0) ||
511 (bonustype == DMU_OT_SA && bonuslen == 0) ||
512 (bonustype != DMU_OT_NONE && bonuslen != 0));
513 ASSERT(DMU_OT_IS_VALID(bonustype));
514 ASSERT3U(bonuslen, <=, DN_MAX_BONUSLEN);
515 ASSERT(dn->dn_type == DMU_OT_NONE);
516 ASSERT0(dn->dn_maxblkid);
517 ASSERT0(dn->dn_allocated_txg);
518 ASSERT0(dn->dn_assigned_txg);
519 ASSERT(refcount_is_zero(&dn->dn_tx_holds));
520 ASSERT3U(refcount_count(&dn->dn_holds), <=, 1);
521 ASSERT3P(list_head(&dn->dn_dbufs), ==, NULL);
522
523 for (i = 0; i < TXG_SIZE; i++) {
524 ASSERT0(dn->dn_next_nblkptr[i]);
525 ASSERT0(dn->dn_next_nlevels[i]);
526 ASSERT0(dn->dn_next_indblkshift[i]);
527 ASSERT0(dn->dn_next_bonuslen[i]);
528 ASSERT0(dn->dn_next_bonustype[i]);
529 ASSERT0(dn->dn_rm_spillblk[i]);
530 ASSERT0(dn->dn_next_blksz[i]);
531 ASSERT(!list_link_active(&dn->dn_dirty_link[i]));
532 ASSERT3P(list_head(&dn->dn_dirty_records[i]), ==, NULL);
533 ASSERT0(avl_numnodes(&dn->dn_ranges[i]));
534 }
535
536 dn->dn_type = ot;
537 dnode_setdblksz(dn, blocksize);
538 dn->dn_indblkshift = ibs;
539 dn->dn_nlevels = 1;
540 if (bonustype == DMU_OT_SA) /* Maximize bonus space for SA */
541 dn->dn_nblkptr = 1;
542 else
543 dn->dn_nblkptr = 1 +
544 ((DN_MAX_BONUSLEN - bonuslen) >> SPA_BLKPTRSHIFT);
545 dn->dn_bonustype = bonustype;
546 dn->dn_bonuslen = bonuslen;
547 dn->dn_checksum = ZIO_CHECKSUM_INHERIT;
548 dn->dn_compress = ZIO_COMPRESS_INHERIT;
549 dn->dn_dirtyctx = 0;
550
551 dn->dn_free_txg = 0;
552 if (dn->dn_dirtyctx_firstset) {
553 kmem_free(dn->dn_dirtyctx_firstset, 1);
554 dn->dn_dirtyctx_firstset = NULL;
555 }
556
557 dn->dn_allocated_txg = tx->tx_txg;
558 dn->dn_id_flags = 0;
559
560 dnode_setdirty(dn, tx);
561 dn->dn_next_indblkshift[tx->tx_txg & TXG_MASK] = ibs;
562 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = dn->dn_bonuslen;
563 dn->dn_next_bonustype[tx->tx_txg & TXG_MASK] = dn->dn_bonustype;
564 dn->dn_next_blksz[tx->tx_txg & TXG_MASK] = dn->dn_datablksz;
565 }
566
567 void
568 dnode_reallocate(dnode_t *dn, dmu_object_type_t ot, int blocksize,
569 dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx)
570 {
571 int nblkptr;
572
573 ASSERT3U(blocksize, >=, SPA_MINBLOCKSIZE);
574 ASSERT3U(blocksize, <=, SPA_MAXBLOCKSIZE);
575 ASSERT0(blocksize % SPA_MINBLOCKSIZE);
576 ASSERT(dn->dn_object != DMU_META_DNODE_OBJECT || dmu_tx_private_ok(tx));
577 ASSERT(tx->tx_txg != 0);
578 ASSERT((bonustype == DMU_OT_NONE && bonuslen == 0) ||
579 (bonustype != DMU_OT_NONE && bonuslen != 0) ||
580 (bonustype == DMU_OT_SA && bonuslen == 0));
581 ASSERT(DMU_OT_IS_VALID(bonustype));
582 ASSERT3U(bonuslen, <=, DN_MAX_BONUSLEN);
583
584 /* clean up any unreferenced dbufs */
585 dnode_evict_dbufs(dn);
586
587 dn->dn_id_flags = 0;
588
589 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
590 dnode_setdirty(dn, tx);
591 if (dn->dn_datablksz != blocksize) {
592 /* change blocksize */
593 ASSERT(dn->dn_maxblkid == 0 &&
594 (BP_IS_HOLE(&dn->dn_phys->dn_blkptr[0]) ||
595 dnode_block_freed(dn, 0)));
596 dnode_setdblksz(dn, blocksize);
597 dn->dn_next_blksz[tx->tx_txg&TXG_MASK] = blocksize;
598 }
599 if (dn->dn_bonuslen != bonuslen)
600 dn->dn_next_bonuslen[tx->tx_txg&TXG_MASK] = bonuslen;
601
602 if (bonustype == DMU_OT_SA) /* Maximize bonus space for SA */
603 nblkptr = 1;
604 else
605 nblkptr = 1 + ((DN_MAX_BONUSLEN - bonuslen) >> SPA_BLKPTRSHIFT);
606 if (dn->dn_bonustype != bonustype)
607 dn->dn_next_bonustype[tx->tx_txg&TXG_MASK] = bonustype;
608 if (dn->dn_nblkptr != nblkptr)
609 dn->dn_next_nblkptr[tx->tx_txg&TXG_MASK] = nblkptr;
610 if (dn->dn_phys->dn_flags & DNODE_FLAG_SPILL_BLKPTR) {
611 dbuf_rm_spill(dn, tx);
612 dnode_rm_spill(dn, tx);
613 }
614 rw_exit(&dn->dn_struct_rwlock);
615
616 /* change type */
617 dn->dn_type = ot;
618
619 /* change bonus size and type */
620 mutex_enter(&dn->dn_mtx);
621 dn->dn_bonustype = bonustype;
622 dn->dn_bonuslen = bonuslen;
623 dn->dn_nblkptr = nblkptr;
624 dn->dn_checksum = ZIO_CHECKSUM_INHERIT;
625 dn->dn_compress = ZIO_COMPRESS_INHERIT;
626 ASSERT3U(dn->dn_nblkptr, <=, DN_MAX_NBLKPTR);
627
628 /* fix up the bonus db_size */
629 if (dn->dn_bonus) {
630 dn->dn_bonus->db.db_size =
631 DN_MAX_BONUSLEN - (dn->dn_nblkptr-1) * sizeof (blkptr_t);
632 ASSERT(dn->dn_bonuslen <= dn->dn_bonus->db.db_size);
633 }
634
635 dn->dn_allocated_txg = tx->tx_txg;
636 mutex_exit(&dn->dn_mtx);
637 }
638
639 #ifdef DNODE_STATS
640 static struct {
641 uint64_t dms_dnode_invalid;
642 uint64_t dms_dnode_recheck1;
643 uint64_t dms_dnode_recheck2;
644 uint64_t dms_dnode_special;
645 uint64_t dms_dnode_handle;
646 uint64_t dms_dnode_rwlock;
647 uint64_t dms_dnode_active;
648 } dnode_move_stats;
649 #endif /* DNODE_STATS */
650
651 static void
652 dnode_move_impl(dnode_t *odn, dnode_t *ndn)
653 {
654 int i;
655
656 ASSERT(!RW_LOCK_HELD(&odn->dn_struct_rwlock));
657 ASSERT(MUTEX_NOT_HELD(&odn->dn_mtx));
658 ASSERT(MUTEX_NOT_HELD(&odn->dn_dbufs_mtx));
659 ASSERT(!RW_LOCK_HELD(&odn->dn_zfetch.zf_rwlock));
660
661 /* Copy fields. */
662 ndn->dn_objset = odn->dn_objset;
663 ndn->dn_object = odn->dn_object;
664 ndn->dn_dbuf = odn->dn_dbuf;
665 ndn->dn_handle = odn->dn_handle;
666 ndn->dn_phys = odn->dn_phys;
667 ndn->dn_type = odn->dn_type;
668 ndn->dn_bonuslen = odn->dn_bonuslen;
669 ndn->dn_bonustype = odn->dn_bonustype;
670 ndn->dn_nblkptr = odn->dn_nblkptr;
671 ndn->dn_checksum = odn->dn_checksum;
672 ndn->dn_compress = odn->dn_compress;
673 ndn->dn_nlevels = odn->dn_nlevels;
674 ndn->dn_indblkshift = odn->dn_indblkshift;
675 ndn->dn_datablkshift = odn->dn_datablkshift;
676 ndn->dn_datablkszsec = odn->dn_datablkszsec;
677 ndn->dn_datablksz = odn->dn_datablksz;
678 ndn->dn_maxblkid = odn->dn_maxblkid;
679 bcopy(&odn->dn_next_nblkptr[0], &ndn->dn_next_nblkptr[0],
680 sizeof (odn->dn_next_nblkptr));
681 bcopy(&odn->dn_next_nlevels[0], &ndn->dn_next_nlevels[0],
682 sizeof (odn->dn_next_nlevels));
683 bcopy(&odn->dn_next_indblkshift[0], &ndn->dn_next_indblkshift[0],
684 sizeof (odn->dn_next_indblkshift));
685 bcopy(&odn->dn_next_bonustype[0], &ndn->dn_next_bonustype[0],
686 sizeof (odn->dn_next_bonustype));
687 bcopy(&odn->dn_rm_spillblk[0], &ndn->dn_rm_spillblk[0],
688 sizeof (odn->dn_rm_spillblk));
689 bcopy(&odn->dn_next_bonuslen[0], &ndn->dn_next_bonuslen[0],
690 sizeof (odn->dn_next_bonuslen));
691 bcopy(&odn->dn_next_blksz[0], &ndn->dn_next_blksz[0],
692 sizeof (odn->dn_next_blksz));
693 for (i = 0; i < TXG_SIZE; i++) {
694 list_move_tail(&ndn->dn_dirty_records[i],
695 &odn->dn_dirty_records[i]);
696 }
697 bcopy(&odn->dn_ranges[0], &ndn->dn_ranges[0], sizeof (odn->dn_ranges));
698 ndn->dn_allocated_txg = odn->dn_allocated_txg;
699 ndn->dn_free_txg = odn->dn_free_txg;
700 ndn->dn_assigned_txg = odn->dn_assigned_txg;
701 ndn->dn_dirtyctx = odn->dn_dirtyctx;
702 ndn->dn_dirtyctx_firstset = odn->dn_dirtyctx_firstset;
703 ASSERT(refcount_count(&odn->dn_tx_holds) == 0);
704 refcount_transfer(&ndn->dn_holds, &odn->dn_holds);
705 ASSERT(list_is_empty(&ndn->dn_dbufs));
706 list_move_tail(&ndn->dn_dbufs, &odn->dn_dbufs);
707 ndn->dn_dbufs_count = odn->dn_dbufs_count;
708 ndn->dn_unlisted_l0_blkid = odn->dn_unlisted_l0_blkid;
709 ndn->dn_bonus = odn->dn_bonus;
710 ndn->dn_have_spill = odn->dn_have_spill;
711 ndn->dn_zio = odn->dn_zio;
712 ndn->dn_oldused = odn->dn_oldused;
713 ndn->dn_oldflags = odn->dn_oldflags;
714 ndn->dn_olduid = odn->dn_olduid;
715 ndn->dn_oldgid = odn->dn_oldgid;
716 ndn->dn_newuid = odn->dn_newuid;
717 ndn->dn_newgid = odn->dn_newgid;
718 ndn->dn_id_flags = odn->dn_id_flags;
719 dmu_zfetch_init(&ndn->dn_zfetch, NULL);
720 list_move_tail(&ndn->dn_zfetch.zf_stream, &odn->dn_zfetch.zf_stream);
721 ndn->dn_zfetch.zf_dnode = odn->dn_zfetch.zf_dnode;
722 ndn->dn_zfetch.zf_stream_cnt = odn->dn_zfetch.zf_stream_cnt;
723 ndn->dn_zfetch.zf_alloc_fail = odn->dn_zfetch.zf_alloc_fail;
724
725 /*
726 * Update back pointers. Updating the handle fixes the back pointer of
727 * every descendant dbuf as well as the bonus dbuf.
728 */
729 ASSERT(ndn->dn_handle->dnh_dnode == odn);
730 ndn->dn_handle->dnh_dnode = ndn;
731 if (ndn->dn_zfetch.zf_dnode == odn) {
732 ndn->dn_zfetch.zf_dnode = ndn;
733 }
734
735 /*
736 * Invalidate the original dnode by clearing all of its back pointers.
737 */
738 odn->dn_dbuf = NULL;
739 odn->dn_handle = NULL;
740 list_create(&odn->dn_dbufs, sizeof (dmu_buf_impl_t),
741 offsetof(dmu_buf_impl_t, db_link));
742 odn->dn_dbufs_count = 0;
743 odn->dn_unlisted_l0_blkid = 0;
744 odn->dn_bonus = NULL;
745 odn->dn_zfetch.zf_dnode = NULL;
746
747 /*
748 * Set the low bit of the objset pointer to ensure that dnode_move()
749 * recognizes the dnode as invalid in any subsequent callback.
750 */
751 POINTER_INVALIDATE(&odn->dn_objset);
752
753 /*
754 * Satisfy the destructor.
755 */
756 for (i = 0; i < TXG_SIZE; i++) {
757 list_create(&odn->dn_dirty_records[i],
758 sizeof (dbuf_dirty_record_t),
759 offsetof(dbuf_dirty_record_t, dr_dirty_node));
760 odn->dn_ranges[i].avl_root = NULL;
761 odn->dn_ranges[i].avl_numnodes = 0;
762 odn->dn_next_nlevels[i] = 0;
763 odn->dn_next_indblkshift[i] = 0;
764 odn->dn_next_bonustype[i] = 0;
765 odn->dn_rm_spillblk[i] = 0;
766 odn->dn_next_bonuslen[i] = 0;
767 odn->dn_next_blksz[i] = 0;
768 }
769 odn->dn_allocated_txg = 0;
770 odn->dn_free_txg = 0;
771 odn->dn_assigned_txg = 0;
772 odn->dn_dirtyctx = 0;
773 odn->dn_dirtyctx_firstset = NULL;
774 odn->dn_have_spill = B_FALSE;
775 odn->dn_zio = NULL;
776 odn->dn_oldused = 0;
777 odn->dn_oldflags = 0;
778 odn->dn_olduid = 0;
779 odn->dn_oldgid = 0;
780 odn->dn_newuid = 0;
781 odn->dn_newgid = 0;
782 odn->dn_id_flags = 0;
783
784 /*
785 * Mark the dnode.
786 */
787 ndn->dn_moved = 1;
788 odn->dn_moved = (uint8_t)-1;
789 }
790
791 #ifdef _KERNEL
792 /*ARGSUSED*/
793 static kmem_cbrc_t
794 dnode_move(void *buf, void *newbuf, size_t size, void *arg)
795 {
796 dnode_t *odn = buf, *ndn = newbuf;
797 objset_t *os;
798 int64_t refcount;
799 uint32_t dbufs;
800
801 /*
802 * The dnode is on the objset's list of known dnodes if the objset
803 * pointer is valid. We set the low bit of the objset pointer when
804 * freeing the dnode to invalidate it, and the memory patterns written
805 * by kmem (baddcafe and deadbeef) set at least one of the two low bits.
806 * A newly created dnode sets the objset pointer last of all to indicate
807 * that the dnode is known and in a valid state to be moved by this
808 * function.
809 */
810 os = odn->dn_objset;
811 if (!POINTER_IS_VALID(os)) {
812 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_invalid);
813 return (KMEM_CBRC_DONT_KNOW);
814 }
815
816 /*
817 * Ensure that the objset does not go away during the move.
818 */
819 rw_enter(&os_lock, RW_WRITER);
820 if (os != odn->dn_objset) {
821 rw_exit(&os_lock);
822 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_recheck1);
823 return (KMEM_CBRC_DONT_KNOW);
824 }
825
826 /*
827 * If the dnode is still valid, then so is the objset. We know that no
828 * valid objset can be freed while we hold os_lock, so we can safely
829 * ensure that the objset remains in use.
830 */
831 mutex_enter(&os->os_lock);
832
833 /*
834 * Recheck the objset pointer in case the dnode was removed just before
835 * acquiring the lock.
836 */
837 if (os != odn->dn_objset) {
838 mutex_exit(&os->os_lock);
839 rw_exit(&os_lock);
840 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_recheck2);
841 return (KMEM_CBRC_DONT_KNOW);
842 }
843
844 /*
845 * At this point we know that as long as we hold os->os_lock, the dnode
846 * cannot be freed and fields within the dnode can be safely accessed.
847 * The objset listing this dnode cannot go away as long as this dnode is
848 * on its list.
849 */
850 rw_exit(&os_lock);
851 if (DMU_OBJECT_IS_SPECIAL(odn->dn_object)) {
852 mutex_exit(&os->os_lock);
853 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_special);
854 return (KMEM_CBRC_NO);
855 }
856 ASSERT(odn->dn_dbuf != NULL); /* only "special" dnodes have no parent */
857
858 /*
859 * Lock the dnode handle to prevent the dnode from obtaining any new
860 * holds. This also prevents the descendant dbufs and the bonus dbuf
861 * from accessing the dnode, so that we can discount their holds. The
862 * handle is safe to access because we know that while the dnode cannot
863 * go away, neither can its handle. Once we hold dnh_zrlock, we can
864 * safely move any dnode referenced only by dbufs.
865 */
866 if (!zrl_tryenter(&odn->dn_handle->dnh_zrlock)) {
867 mutex_exit(&os->os_lock);
868 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_handle);
869 return (KMEM_CBRC_LATER);
870 }
871
872 /*
873 * Ensure a consistent view of the dnode's holds and the dnode's dbufs.
874 * We need to guarantee that there is a hold for every dbuf in order to
875 * determine whether the dnode is actively referenced. Falsely matching
876 * a dbuf to an active hold would lead to an unsafe move. It's possible
877 * that a thread already having an active dnode hold is about to add a
878 * dbuf, and we can't compare hold and dbuf counts while the add is in
879 * progress.
880 */
881 if (!rw_tryenter(&odn->dn_struct_rwlock, RW_WRITER)) {
882 zrl_exit(&odn->dn_handle->dnh_zrlock);
883 mutex_exit(&os->os_lock);
884 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_rwlock);
885 return (KMEM_CBRC_LATER);
886 }
887
888 /*
889 * A dbuf may be removed (evicted) without an active dnode hold. In that
890 * case, the dbuf count is decremented under the handle lock before the
891 * dbuf's hold is released. This order ensures that if we count the hold
892 * after the dbuf is removed but before its hold is released, we will
893 * treat the unmatched hold as active and exit safely. If we count the
894 * hold before the dbuf is removed, the hold is discounted, and the
895 * removal is blocked until the move completes.
896 */
897 refcount = refcount_count(&odn->dn_holds);
898 ASSERT(refcount >= 0);
899 dbufs = odn->dn_dbufs_count;
900
901 /* We can't have more dbufs than dnode holds. */
902 ASSERT3U(dbufs, <=, refcount);
903 DTRACE_PROBE3(dnode__move, dnode_t *, odn, int64_t, refcount,
904 uint32_t, dbufs);
905
906 if (refcount > dbufs) {
907 rw_exit(&odn->dn_struct_rwlock);
908 zrl_exit(&odn->dn_handle->dnh_zrlock);
909 mutex_exit(&os->os_lock);
910 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_active);
911 return (KMEM_CBRC_LATER);
912 }
913
914 rw_exit(&odn->dn_struct_rwlock);
915
916 /*
917 * At this point we know that anyone with a hold on the dnode is not
918 * actively referencing it. The dnode is known and in a valid state to
919 * move. We're holding the locks needed to execute the critical section.
920 */
921 dnode_move_impl(odn, ndn);
922
923 list_link_replace(&odn->dn_link, &ndn->dn_link);
924 /* If the dnode was safe to move, the refcount cannot have changed. */
925 ASSERT(refcount == refcount_count(&ndn->dn_holds));
926 ASSERT(dbufs == ndn->dn_dbufs_count);
927 zrl_exit(&ndn->dn_handle->dnh_zrlock); /* handle has moved */
928 mutex_exit(&os->os_lock);
929
930 return (KMEM_CBRC_YES);
931 }
932 #endif /* _KERNEL */
933
934 void
935 dnode_special_close(dnode_handle_t *dnh)
936 {
937 dnode_t *dn = dnh->dnh_dnode;
938
939 /*
940 * Wait for final references to the dnode to clear. This can
941 * only happen if the arc is asyncronously evicting state that
942 * has a hold on this dnode while we are trying to evict this
943 * dnode.
944 */
945 while (refcount_count(&dn->dn_holds) > 0)
946 delay(1);
947 zrl_add(&dnh->dnh_zrlock);
948 dnode_destroy(dn); /* implicit zrl_remove() */
949 zrl_destroy(&dnh->dnh_zrlock);
950 dnh->dnh_dnode = NULL;
951 }
952
953 dnode_t *
954 dnode_special_open(objset_t *os, dnode_phys_t *dnp, uint64_t object,
955 dnode_handle_t *dnh)
956 {
957 dnode_t *dn = dnode_create(os, dnp, NULL, object, dnh);
958 dnh->dnh_dnode = dn;
959 zrl_init(&dnh->dnh_zrlock);
960 DNODE_VERIFY(dn);
961 return (dn);
962 }
963
964 static void
965 dnode_buf_pageout(dmu_buf_t *db, void *arg)
966 {
967 dnode_children_t *children_dnodes = arg;
968 int i;
969 int epb = db->db_size >> DNODE_SHIFT;
970
971 ASSERT(epb == children_dnodes->dnc_count);
972
973 for (i = 0; i < epb; i++) {
974 dnode_handle_t *dnh = &children_dnodes->dnc_children[i];
975 dnode_t *dn;
976
977 /*
978 * The dnode handle lock guards against the dnode moving to
979 * another valid address, so there is no need here to guard
980 * against changes to or from NULL.
981 */
982 if (dnh->dnh_dnode == NULL) {
983 zrl_destroy(&dnh->dnh_zrlock);
984 continue;
985 }
986
987 zrl_add(&dnh->dnh_zrlock);
988 dn = dnh->dnh_dnode;
989 /*
990 * If there are holds on this dnode, then there should
991 * be holds on the dnode's containing dbuf as well; thus
992 * it wouldn't be eligible for eviction and this function
993 * would not have been called.
994 */
995 ASSERT(refcount_is_zero(&dn->dn_holds));
996 ASSERT(refcount_is_zero(&dn->dn_tx_holds));
997
998 dnode_destroy(dn); /* implicit zrl_remove() */
999 zrl_destroy(&dnh->dnh_zrlock);
1000 dnh->dnh_dnode = NULL;
1001 }
1002 kmem_free(children_dnodes, sizeof (dnode_children_t) +
1003 (epb - 1) * sizeof (dnode_handle_t));
1004 }
1005
1006 /*
1007 * errors:
1008 * EINVAL - invalid object number.
1009 * EIO - i/o error.
1010 * succeeds even for free dnodes.
1011 */
1012 int
1013 dnode_hold_impl(objset_t *os, uint64_t object, int flag,
1014 void *tag, dnode_t **dnp)
1015 {
1016 int epb, idx, err;
1017 int drop_struct_lock = FALSE;
1018 int type;
1019 uint64_t blk;
1020 dnode_t *mdn, *dn;
1021 dmu_buf_impl_t *db;
1022 dnode_children_t *children_dnodes;
1023 dnode_handle_t *dnh;
1024
1025 /*
1026 * If you are holding the spa config lock as writer, you shouldn't
1027 * be asking the DMU to do *anything* unless it's the root pool
1028 * which may require us to read from the root filesystem while
1029 * holding some (not all) of the locks as writer.
1030 */
1031 ASSERT(spa_config_held(os->os_spa, SCL_ALL, RW_WRITER) == 0 ||
1032 (spa_is_root(os->os_spa) &&
1033 spa_config_held(os->os_spa, SCL_STATE, RW_WRITER)));
1034
1035 if (object == DMU_USERUSED_OBJECT || object == DMU_GROUPUSED_OBJECT) {
1036 dn = (object == DMU_USERUSED_OBJECT) ?
1037 DMU_USERUSED_DNODE(os) : DMU_GROUPUSED_DNODE(os);
1038 if (dn == NULL)
1039 return (SET_ERROR(ENOENT));
1040 type = dn->dn_type;
1041 if ((flag & DNODE_MUST_BE_ALLOCATED) && type == DMU_OT_NONE)
1042 return (SET_ERROR(ENOENT));
1043 if ((flag & DNODE_MUST_BE_FREE) && type != DMU_OT_NONE)
1044 return (SET_ERROR(EEXIST));
1045 DNODE_VERIFY(dn);
1046 (void) refcount_add(&dn->dn_holds, tag);
1047 *dnp = dn;
1048 return (0);
1049 }
1050
1051 if (object == 0 || object >= DN_MAX_OBJECT)
1052 return (SET_ERROR(EINVAL));
1053
1054 mdn = DMU_META_DNODE(os);
1055 ASSERT(mdn->dn_object == DMU_META_DNODE_OBJECT);
1056
1057 DNODE_VERIFY(mdn);
1058
1059 if (!RW_WRITE_HELD(&mdn->dn_struct_rwlock)) {
1060 rw_enter(&mdn->dn_struct_rwlock, RW_READER);
1061 drop_struct_lock = TRUE;
1062 }
1063
1064 blk = dbuf_whichblock(mdn, object * sizeof (dnode_phys_t));
1065
1066 db = dbuf_hold(mdn, blk, FTAG);
1067 if (drop_struct_lock)
1068 rw_exit(&mdn->dn_struct_rwlock);
1069 if (db == NULL)
1070 return (SET_ERROR(EIO));
1071 err = dbuf_read(db, NULL, DB_RF_CANFAIL);
1072 if (err) {
1073 dbuf_rele(db, FTAG);
1074 return (err);
1075 }
1076
1077 ASSERT3U(db->db.db_size, >=, 1<<DNODE_SHIFT);
1078 epb = db->db.db_size >> DNODE_SHIFT;
1079
1080 idx = object & (epb-1);
1081
1082 ASSERT(DB_DNODE(db)->dn_type == DMU_OT_DNODE);
1083 children_dnodes = dmu_buf_get_user(&db->db);
1084 if (children_dnodes == NULL) {
1085 int i;
1086 dnode_children_t *winner;
1087 children_dnodes = kmem_alloc(sizeof (dnode_children_t) +
1088 (epb - 1) * sizeof (dnode_handle_t), KM_SLEEP);
1089 children_dnodes->dnc_count = epb;
1090 dnh = &children_dnodes->dnc_children[0];
1091 for (i = 0; i < epb; i++) {
1092 zrl_init(&dnh[i].dnh_zrlock);
1093 dnh[i].dnh_dnode = NULL;
1094 }
1095 if (winner = dmu_buf_set_user(&db->db, children_dnodes, NULL,
1096 dnode_buf_pageout)) {
1097 kmem_free(children_dnodes, sizeof (dnode_children_t) +
1098 (epb - 1) * sizeof (dnode_handle_t));
1099 children_dnodes = winner;
1100 }
1101 }
1102 ASSERT(children_dnodes->dnc_count == epb);
1103
1104 dnh = &children_dnodes->dnc_children[idx];
1105 zrl_add(&dnh->dnh_zrlock);
1106 if ((dn = dnh->dnh_dnode) == NULL) {
1107 dnode_phys_t *phys = (dnode_phys_t *)db->db.db_data+idx;
1108 dnode_t *winner;
1109
1110 dn = dnode_create(os, phys, db, object, dnh);
1111 winner = atomic_cas_ptr(&dnh->dnh_dnode, NULL, dn);
1112 if (winner != NULL) {
1113 zrl_add(&dnh->dnh_zrlock);
1114 dnode_destroy(dn); /* implicit zrl_remove() */
1115 dn = winner;
1116 }
1117 }
1118
1119 mutex_enter(&dn->dn_mtx);
1120 type = dn->dn_type;
1121 if (dn->dn_free_txg ||
1122 ((flag & DNODE_MUST_BE_ALLOCATED) && type == DMU_OT_NONE) ||
1123 ((flag & DNODE_MUST_BE_FREE) &&
1124 (type != DMU_OT_NONE || !refcount_is_zero(&dn->dn_holds)))) {
1125 mutex_exit(&dn->dn_mtx);
1126 zrl_remove(&dnh->dnh_zrlock);
1127 dbuf_rele(db, FTAG);
1128 return (type == DMU_OT_NONE ? ENOENT : EEXIST);
1129 }
1130 mutex_exit(&dn->dn_mtx);
1131
1132 if (refcount_add(&dn->dn_holds, tag) == 1)
1133 dbuf_add_ref(db, dnh);
1134 /* Now we can rely on the hold to prevent the dnode from moving. */
1135 zrl_remove(&dnh->dnh_zrlock);
1136
1137 DNODE_VERIFY(dn);
1138 ASSERT3P(dn->dn_dbuf, ==, db);
1139 ASSERT3U(dn->dn_object, ==, object);
1140 dbuf_rele(db, FTAG);
1141
1142 *dnp = dn;
1143 return (0);
1144 }
1145
1146 /*
1147 * Return held dnode if the object is allocated, NULL if not.
1148 */
1149 int
1150 dnode_hold(objset_t *os, uint64_t object, void *tag, dnode_t **dnp)
1151 {
1152 return (dnode_hold_impl(os, object, DNODE_MUST_BE_ALLOCATED, tag, dnp));
1153 }
1154
1155 /*
1156 * Can only add a reference if there is already at least one
1157 * reference on the dnode. Returns FALSE if unable to add a
1158 * new reference.
1159 */
1160 boolean_t
1161 dnode_add_ref(dnode_t *dn, void *tag)
1162 {
1163 mutex_enter(&dn->dn_mtx);
1164 if (refcount_is_zero(&dn->dn_holds)) {
1165 mutex_exit(&dn->dn_mtx);
1166 return (FALSE);
1167 }
1168 VERIFY(1 < refcount_add(&dn->dn_holds, tag));
1169 mutex_exit(&dn->dn_mtx);
1170 return (TRUE);
1171 }
1172
1173 void
1174 dnode_rele(dnode_t *dn, void *tag)
1175 {
1176 uint64_t refs;
1177 /* Get while the hold prevents the dnode from moving. */
1178 dmu_buf_impl_t *db = dn->dn_dbuf;
1179 dnode_handle_t *dnh = dn->dn_handle;
1180
1181 mutex_enter(&dn->dn_mtx);
1182 refs = refcount_remove(&dn->dn_holds, tag);
1183 mutex_exit(&dn->dn_mtx);
1184
1185 /*
1186 * It's unsafe to release the last hold on a dnode by dnode_rele() or
1187 * indirectly by dbuf_rele() while relying on the dnode handle to
1188 * prevent the dnode from moving, since releasing the last hold could
1189 * result in the dnode's parent dbuf evicting its dnode handles. For
1190 * that reason anyone calling dnode_rele() or dbuf_rele() without some
1191 * other direct or indirect hold on the dnode must first drop the dnode
1192 * handle.
1193 */
1194 ASSERT(refs > 0 || dnh->dnh_zrlock.zr_owner != curthread);
1195
1196 /* NOTE: the DNODE_DNODE does not have a dn_dbuf */
1197 if (refs == 0 && db != NULL) {
1198 /*
1199 * Another thread could add a hold to the dnode handle in
1200 * dnode_hold_impl() while holding the parent dbuf. Since the
1201 * hold on the parent dbuf prevents the handle from being
1202 * destroyed, the hold on the handle is OK. We can't yet assert
1203 * that the handle has zero references, but that will be
1204 * asserted anyway when the handle gets destroyed.
1205 */
1206 dbuf_rele(db, dnh);
1207 }
1208 }
1209
1210 void
1211 dnode_setdirty(dnode_t *dn, dmu_tx_t *tx)
1212 {
1213 objset_t *os = dn->dn_objset;
1214 uint64_t txg = tx->tx_txg;
1215
1216 if (DMU_OBJECT_IS_SPECIAL(dn->dn_object)) {
1217 dsl_dataset_dirty(os->os_dsl_dataset, tx);
1218 return;
1219 }
1220
1221 DNODE_VERIFY(dn);
1222
1223 #ifdef ZFS_DEBUG
1224 mutex_enter(&dn->dn_mtx);
1225 ASSERT(dn->dn_phys->dn_type || dn->dn_allocated_txg);
1226 ASSERT(dn->dn_free_txg == 0 || dn->dn_free_txg >= txg);
1227 mutex_exit(&dn->dn_mtx);
1228 #endif
1229
1230 /*
1231 * Determine old uid/gid when necessary
1232 */
1233 dmu_objset_userquota_get_ids(dn, B_TRUE, tx);
1234
1235 mutex_enter(&os->os_lock);
1236
1237 /*
1238 * If we are already marked dirty, we're done.
1239 */
1240 if (list_link_active(&dn->dn_dirty_link[txg & TXG_MASK])) {
1241 mutex_exit(&os->os_lock);
1242 return;
1243 }
1244
1245 ASSERT(!refcount_is_zero(&dn->dn_holds) || list_head(&dn->dn_dbufs));
1246 ASSERT(dn->dn_datablksz != 0);
1247 ASSERT0(dn->dn_next_bonuslen[txg&TXG_MASK]);
1248 ASSERT0(dn->dn_next_blksz[txg&TXG_MASK]);
1249 ASSERT0(dn->dn_next_bonustype[txg&TXG_MASK]);
1250
1251 dprintf_ds(os->os_dsl_dataset, "obj=%llu txg=%llu\n",
1252 dn->dn_object, txg);
1253
1254 if (dn->dn_free_txg > 0 && dn->dn_free_txg <= txg) {
1255 list_insert_tail(&os->os_free_dnodes[txg&TXG_MASK], dn);
1256 } else {
1257 list_insert_tail(&os->os_dirty_dnodes[txg&TXG_MASK], dn);
1258 }
1259
1260 mutex_exit(&os->os_lock);
1261
1262 /*
1263 * The dnode maintains a hold on its containing dbuf as
1264 * long as there are holds on it. Each instantiated child
1265 * dbuf maintains a hold on the dnode. When the last child
1266 * drops its hold, the dnode will drop its hold on the
1267 * containing dbuf. We add a "dirty hold" here so that the
1268 * dnode will hang around after we finish processing its
1269 * children.
1270 */
1271 VERIFY(dnode_add_ref(dn, (void *)(uintptr_t)tx->tx_txg));
1272
1273 (void) dbuf_dirty(dn->dn_dbuf, tx);
1274
1275 dsl_dataset_dirty(os->os_dsl_dataset, tx);
1276 }
1277
1278 void
1279 dnode_free(dnode_t *dn, dmu_tx_t *tx)
1280 {
1281 int txgoff = tx->tx_txg & TXG_MASK;
1282
1283 dprintf("dn=%p txg=%llu\n", dn, tx->tx_txg);
1284
1285 /* we should be the only holder... hopefully */
1286 /* ASSERT3U(refcount_count(&dn->dn_holds), ==, 1); */
1287
1288 mutex_enter(&dn->dn_mtx);
1289 if (dn->dn_type == DMU_OT_NONE || dn->dn_free_txg) {
1290 mutex_exit(&dn->dn_mtx);
1291 return;
1292 }
1293 dn->dn_free_txg = tx->tx_txg;
1294 mutex_exit(&dn->dn_mtx);
1295
1296 /*
1297 * If the dnode is already dirty, it needs to be moved from
1298 * the dirty list to the free list.
1299 */
1300 mutex_enter(&dn->dn_objset->os_lock);
1301 if (list_link_active(&dn->dn_dirty_link[txgoff])) {
1302 list_remove(&dn->dn_objset->os_dirty_dnodes[txgoff], dn);
1303 list_insert_tail(&dn->dn_objset->os_free_dnodes[txgoff], dn);
1304 mutex_exit(&dn->dn_objset->os_lock);
1305 } else {
1306 mutex_exit(&dn->dn_objset->os_lock);
1307 dnode_setdirty(dn, tx);
1308 }
1309 }
1310
1311 /*
1312 * Try to change the block size for the indicated dnode. This can only
1313 * succeed if there are no blocks allocated or dirty beyond first block
1314 */
1315 int
1316 dnode_set_blksz(dnode_t *dn, uint64_t size, int ibs, dmu_tx_t *tx)
1317 {
1318 dmu_buf_impl_t *db, *db_next;
1319 int err;
1320
1321 if (size == 0)
1322 size = SPA_MINBLOCKSIZE;
1323 if (size > SPA_MAXBLOCKSIZE)
1324 size = SPA_MAXBLOCKSIZE;
1325 else
1326 size = P2ROUNDUP(size, SPA_MINBLOCKSIZE);
1327
1328 if (ibs == dn->dn_indblkshift)
1329 ibs = 0;
1330
1331 if (size >> SPA_MINBLOCKSHIFT == dn->dn_datablkszsec && ibs == 0)
1332 return (0);
1333
1334 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
1335
1336 /* Check for any allocated blocks beyond the first */
1337 if (dn->dn_maxblkid != 0)
1338 goto fail;
1339
1340 mutex_enter(&dn->dn_dbufs_mtx);
1341 for (db = list_head(&dn->dn_dbufs); db; db = db_next) {
1342 db_next = list_next(&dn->dn_dbufs, db);
1343
1344 if (db->db_blkid != 0 && db->db_blkid != DMU_BONUS_BLKID &&
1345 db->db_blkid != DMU_SPILL_BLKID) {
1346 mutex_exit(&dn->dn_dbufs_mtx);
1347 goto fail;
1348 }
1349 }
1350 mutex_exit(&dn->dn_dbufs_mtx);
1351
1352 if (ibs && dn->dn_nlevels != 1)
1353 goto fail;
1354
1355 /* resize the old block */
1356 err = dbuf_hold_impl(dn, 0, 0, TRUE, FTAG, &db);
1357 if (err == 0)
1358 dbuf_new_size(db, size, tx);
1359 else if (err != ENOENT)
1360 goto fail;
1361
1362 dnode_setdblksz(dn, size);
1363 dnode_setdirty(dn, tx);
1364 dn->dn_next_blksz[tx->tx_txg&TXG_MASK] = size;
1365 if (ibs) {
1366 dn->dn_indblkshift = ibs;
1367 dn->dn_next_indblkshift[tx->tx_txg&TXG_MASK] = ibs;
1368 }
1369 /* rele after we have fixed the blocksize in the dnode */
1370 if (db)
1371 dbuf_rele(db, FTAG);
1372
1373 rw_exit(&dn->dn_struct_rwlock);
1374 return (0);
1375
1376 fail:
1377 rw_exit(&dn->dn_struct_rwlock);
1378 return (SET_ERROR(ENOTSUP));
1379 }
1380
1381 /* read-holding callers must not rely on the lock being continuously held */
1382 void
1383 dnode_new_blkid(dnode_t *dn, uint64_t blkid, dmu_tx_t *tx, boolean_t have_read)
1384 {
1385 uint64_t txgoff = tx->tx_txg & TXG_MASK;
1386 int epbs, new_nlevels;
1387 uint64_t sz;
1388
1389 ASSERT(blkid != DMU_BONUS_BLKID);
1390
1391 ASSERT(have_read ?
1392 RW_READ_HELD(&dn->dn_struct_rwlock) :
1393 RW_WRITE_HELD(&dn->dn_struct_rwlock));
1394
1395 /*
1396 * if we have a read-lock, check to see if we need to do any work
1397 * before upgrading to a write-lock.
1398 */
1399 if (have_read) {
1400 if (blkid <= dn->dn_maxblkid)
1401 return;
1402
1403 if (!rw_tryupgrade(&dn->dn_struct_rwlock)) {
1404 rw_exit(&dn->dn_struct_rwlock);
1405 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
1406 }
1407 }
1408
1409 if (blkid <= dn->dn_maxblkid)
1410 goto out;
1411
1412 dn->dn_maxblkid = blkid;
1413
1414 /*
1415 * Compute the number of levels necessary to support the new maxblkid.
1416 */
1417 new_nlevels = 1;
1418 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT;
1419 for (sz = dn->dn_nblkptr;
1420 sz <= blkid && sz >= dn->dn_nblkptr; sz <<= epbs)
1421 new_nlevels++;
1422
1423 if (new_nlevels > dn->dn_nlevels) {
1424 int old_nlevels = dn->dn_nlevels;
1425 dmu_buf_impl_t *db;
1426 list_t *list;
1427 dbuf_dirty_record_t *new, *dr, *dr_next;
1428
1429 dn->dn_nlevels = new_nlevels;
1430
1431 ASSERT3U(new_nlevels, >, dn->dn_next_nlevels[txgoff]);
1432 dn->dn_next_nlevels[txgoff] = new_nlevels;
1433
1434 /* dirty the left indirects */
1435 db = dbuf_hold_level(dn, old_nlevels, 0, FTAG);
1436 ASSERT(db != NULL);
1437 new = dbuf_dirty(db, tx);
1438 dbuf_rele(db, FTAG);
1439
1440 /* transfer the dirty records to the new indirect */
1441 mutex_enter(&dn->dn_mtx);
1442 mutex_enter(&new->dt.di.dr_mtx);
1443 list = &dn->dn_dirty_records[txgoff];
1444 for (dr = list_head(list); dr; dr = dr_next) {
1445 dr_next = list_next(&dn->dn_dirty_records[txgoff], dr);
1446 if (dr->dr_dbuf->db_level != new_nlevels-1 &&
1447 dr->dr_dbuf->db_blkid != DMU_BONUS_BLKID &&
1448 dr->dr_dbuf->db_blkid != DMU_SPILL_BLKID) {
1449 ASSERT(dr->dr_dbuf->db_level == old_nlevels-1);
1450 list_remove(&dn->dn_dirty_records[txgoff], dr);
1451 list_insert_tail(&new->dt.di.dr_children, dr);
1452 dr->dr_parent = new;
1453 }
1454 }
1455 mutex_exit(&new->dt.di.dr_mtx);
1456 mutex_exit(&dn->dn_mtx);
1457 }
1458
1459 out:
1460 if (have_read)
1461 rw_downgrade(&dn->dn_struct_rwlock);
1462 }
1463
1464 void
1465 dnode_clear_range(dnode_t *dn, uint64_t blkid, uint64_t nblks, dmu_tx_t *tx)
1466 {
1467 avl_tree_t *tree = &dn->dn_ranges[tx->tx_txg&TXG_MASK];
1468 avl_index_t where;
1469 free_range_t *rp;
1470 free_range_t rp_tofind;
1471 uint64_t endblk = blkid + nblks;
1472
1473 ASSERT(MUTEX_HELD(&dn->dn_mtx));
1474 ASSERT(nblks <= UINT64_MAX - blkid); /* no overflow */
1475
1476 dprintf_dnode(dn, "blkid=%llu nblks=%llu txg=%llu\n",
1477 blkid, nblks, tx->tx_txg);
1478 rp_tofind.fr_blkid = blkid;
1479 rp = avl_find(tree, &rp_tofind, &where);
1480 if (rp == NULL)
1481 rp = avl_nearest(tree, where, AVL_BEFORE);
1482 if (rp == NULL)
1483 rp = avl_nearest(tree, where, AVL_AFTER);
1484
1485 while (rp && (rp->fr_blkid <= blkid + nblks)) {
1486 uint64_t fr_endblk = rp->fr_blkid + rp->fr_nblks;
1487 free_range_t *nrp = AVL_NEXT(tree, rp);
1488
1489 if (blkid <= rp->fr_blkid && endblk >= fr_endblk) {
1490 /* clear this entire range */
1491 avl_remove(tree, rp);
1492 kmem_free(rp, sizeof (free_range_t));
1493 } else if (blkid <= rp->fr_blkid &&
1494 endblk > rp->fr_blkid && endblk < fr_endblk) {
1495 /* clear the beginning of this range */
1496 rp->fr_blkid = endblk;
1497 rp->fr_nblks = fr_endblk - endblk;
1498 } else if (blkid > rp->fr_blkid && blkid < fr_endblk &&
1499 endblk >= fr_endblk) {
1500 /* clear the end of this range */
1501 rp->fr_nblks = blkid - rp->fr_blkid;
1502 } else if (blkid > rp->fr_blkid && endblk < fr_endblk) {
1503 /* clear a chunk out of this range */
1504 free_range_t *new_rp =
1505 kmem_alloc(sizeof (free_range_t), KM_SLEEP);
1506
1507 new_rp->fr_blkid = endblk;
1508 new_rp->fr_nblks = fr_endblk - endblk;
1509 avl_insert_here(tree, new_rp, rp, AVL_AFTER);
1510 rp->fr_nblks = blkid - rp->fr_blkid;
1511 }
1512 /* there may be no overlap */
1513 rp = nrp;
1514 }
1515 }
1516
1517 void
1518 dnode_free_range(dnode_t *dn, uint64_t off, uint64_t len, dmu_tx_t *tx)
1519 {
1520 dmu_buf_impl_t *db;
1521 uint64_t blkoff, blkid, nblks;
1522 int blksz, blkshift, head, tail;
1523 int trunc = FALSE;
1524 int epbs;
1525
1526 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
1527 blksz = dn->dn_datablksz;
1528 blkshift = dn->dn_datablkshift;
1529 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT;
1530
1531 if (len == DMU_OBJECT_END) {
1532 len = UINT64_MAX - off;
1533 trunc = TRUE;
1534 }
1535
1536 /*
1537 * First, block align the region to free:
1538 */
1539 if (ISP2(blksz)) {
1540 head = P2NPHASE(off, blksz);
1541 blkoff = P2PHASE(off, blksz);
1542 if ((off >> blkshift) > dn->dn_maxblkid)
1543 goto out;
1544 } else {
1545 ASSERT(dn->dn_maxblkid == 0);
1546 if (off == 0 && len >= blksz) {
1547 /* Freeing the whole block; fast-track this request */
1548 blkid = 0;
1549 nblks = 1;
1550 goto done;
1551 } else if (off >= blksz) {
1552 /* Freeing past end-of-data */
1553 goto out;
1554 } else {
1555 /* Freeing part of the block. */
1556 head = blksz - off;
1557 ASSERT3U(head, >, 0);
1558 }
1559 blkoff = off;
1560 }
1561 /* zero out any partial block data at the start of the range */
1562 if (head) {
1563 ASSERT3U(blkoff + head, ==, blksz);
1564 if (len < head)
1565 head = len;
1566 if (dbuf_hold_impl(dn, 0, dbuf_whichblock(dn, off), TRUE,
1567 FTAG, &db) == 0) {
1568 caddr_t data;
1569
1570 /* don't dirty if it isn't on disk and isn't dirty */
1571 if (db->db_last_dirty ||
1572 (db->db_blkptr && !BP_IS_HOLE(db->db_blkptr))) {
1573 rw_exit(&dn->dn_struct_rwlock);
1574 dbuf_will_dirty(db, tx);
1575 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
1576 data = db->db.db_data;
1577 bzero(data + blkoff, head);
1578 }
1579 dbuf_rele(db, FTAG);
1580 }
1581 off += head;
1582 len -= head;
1583 }
1584
1585 /* If the range was less than one block, we're done */
1586 if (len == 0)
1587 goto out;
1588
1589 /* If the remaining range is past end of file, we're done */
1590 if ((off >> blkshift) > dn->dn_maxblkid)
1591 goto out;
1592
1593 ASSERT(ISP2(blksz));
1594 if (trunc)
1595 tail = 0;
1596 else
1597 tail = P2PHASE(len, blksz);
1598
1599 ASSERT0(P2PHASE(off, blksz));
1600 /* zero out any partial block data at the end of the range */
1601 if (tail) {
1602 if (len < tail)
1603 tail = len;
1604 if (dbuf_hold_impl(dn, 0, dbuf_whichblock(dn, off+len),
1605 TRUE, FTAG, &db) == 0) {
1606 /* don't dirty if not on disk and not dirty */
1607 if (db->db_last_dirty ||
1608 (db->db_blkptr && !BP_IS_HOLE(db->db_blkptr))) {
1609 rw_exit(&dn->dn_struct_rwlock);
1610 dbuf_will_dirty(db, tx);
1611 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
1612 bzero(db->db.db_data, tail);
1613 }
1614 dbuf_rele(db, FTAG);
1615 }
1616 len -= tail;
1617 }
1618
1619 /* If the range did not include a full block, we are done */
1620 if (len == 0)
1621 goto out;
1622
1623 ASSERT(IS_P2ALIGNED(off, blksz));
1624 ASSERT(trunc || IS_P2ALIGNED(len, blksz));
1625 blkid = off >> blkshift;
1626 nblks = len >> blkshift;
1627 if (trunc)
1628 nblks += 1;
1629
1630 /*
1631 * Read in and mark all the level-1 indirects dirty,
1632 * so that they will stay in memory until syncing phase.
1633 * Always dirty the first and last indirect to make sure
1634 * we dirty all the partial indirects.
1635 */
1636 if (dn->dn_nlevels > 1) {
1637 uint64_t i, first, last;
1638 int shift = epbs + dn->dn_datablkshift;
1639
1640 first = blkid >> epbs;
1641 if (db = dbuf_hold_level(dn, 1, first, FTAG)) {
1642 dbuf_will_dirty(db, tx);
1643 dbuf_rele(db, FTAG);
1644 }
1645 if (trunc)
1646 last = dn->dn_maxblkid >> epbs;
1647 else
1648 last = (blkid + nblks - 1) >> epbs;
1649 if (last > first && (db = dbuf_hold_level(dn, 1, last, FTAG))) {
1650 dbuf_will_dirty(db, tx);
1651 dbuf_rele(db, FTAG);
1652 }
1653 for (i = first + 1; i < last; i++) {
1654 uint64_t ibyte = i << shift;
1655 int err;
1656
1657 err = dnode_next_offset(dn,
1658 DNODE_FIND_HAVELOCK, &ibyte, 1, 1, 0);
1659 i = ibyte >> shift;
1660 if (err == ESRCH || i >= last)
1661 break;
1662 ASSERT(err == 0);
1663 db = dbuf_hold_level(dn, 1, i, FTAG);
1664 if (db) {
1665 dbuf_will_dirty(db, tx);
1666 dbuf_rele(db, FTAG);
1667 }
1668 }
1669 }
1670 done:
1671 /*
1672 * Add this range to the dnode range list.
1673 * We will finish up this free operation in the syncing phase.
1674 */
1675 mutex_enter(&dn->dn_mtx);
1676 dnode_clear_range(dn, blkid, nblks, tx);
1677 {
1678 free_range_t *rp, *found;
1679 avl_index_t where;
1680 avl_tree_t *tree = &dn->dn_ranges[tx->tx_txg&TXG_MASK];
1681
1682 /* Add new range to dn_ranges */
1683 rp = kmem_alloc(sizeof (free_range_t), KM_SLEEP);
1684 rp->fr_blkid = blkid;
1685 rp->fr_nblks = nblks;
1686 found = avl_find(tree, rp, &where);
1687 ASSERT(found == NULL);
1688 avl_insert(tree, rp, where);
1689 dprintf_dnode(dn, "blkid=%llu nblks=%llu txg=%llu\n",
1690 blkid, nblks, tx->tx_txg);
1691 }
1692 mutex_exit(&dn->dn_mtx);
1693
1694 dbuf_free_range(dn, blkid, blkid + nblks - 1, tx);
1695 dnode_setdirty(dn, tx);
1696 out:
1697 if (trunc && dn->dn_maxblkid >= (off >> blkshift))
1698 dn->dn_maxblkid = (off >> blkshift ? (off >> blkshift) - 1 : 0);
1699
1700 rw_exit(&dn->dn_struct_rwlock);
1701 }
1702
1703 static boolean_t
1704 dnode_spill_freed(dnode_t *dn)
1705 {
1706 int i;
1707
1708 mutex_enter(&dn->dn_mtx);
1709 for (i = 0; i < TXG_SIZE; i++) {
1710 if (dn->dn_rm_spillblk[i] == DN_KILL_SPILLBLK)
1711 break;
1712 }
1713 mutex_exit(&dn->dn_mtx);
1714 return (i < TXG_SIZE);
1715 }
1716
1717 /* return TRUE if this blkid was freed in a recent txg, or FALSE if it wasn't */
1718 uint64_t
1719 dnode_block_freed(dnode_t *dn, uint64_t blkid)
1720 {
1721 free_range_t range_tofind;
1722 void *dp = spa_get_dsl(dn->dn_objset->os_spa);
1723 int i;
1724
1725 if (blkid == DMU_BONUS_BLKID)
1726 return (FALSE);
1727
1728 /*
1729 * If we're in the process of opening the pool, dp will not be
1730 * set yet, but there shouldn't be anything dirty.
1731 */
1732 if (dp == NULL)
1733 return (FALSE);
1734
1735 if (dn->dn_free_txg)
1736 return (TRUE);
1737
1738 if (blkid == DMU_SPILL_BLKID)
1739 return (dnode_spill_freed(dn));
1740
1741 range_tofind.fr_blkid = blkid;
1742 mutex_enter(&dn->dn_mtx);
1743 for (i = 0; i < TXG_SIZE; i++) {
1744 free_range_t *range_found;
1745 avl_index_t idx;
1746
1747 range_found = avl_find(&dn->dn_ranges[i], &range_tofind, &idx);
1748 if (range_found) {
1749 ASSERT(range_found->fr_nblks > 0);
1750 break;
1751 }
1752 range_found = avl_nearest(&dn->dn_ranges[i], idx, AVL_BEFORE);
1753 if (range_found &&
1754 range_found->fr_blkid + range_found->fr_nblks > blkid)
1755 break;
1756 }
1757 mutex_exit(&dn->dn_mtx);
1758 return (i < TXG_SIZE);
1759 }
1760
1761 /* call from syncing context when we actually write/free space for this dnode */
1762 void
1763 dnode_diduse_space(dnode_t *dn, int64_t delta)
1764 {
1765 uint64_t space;
1766 dprintf_dnode(dn, "dn=%p dnp=%p used=%llu delta=%lld\n",
1767 dn, dn->dn_phys,
1768 (u_longlong_t)dn->dn_phys->dn_used,
1769 (longlong_t)delta);
1770
1771 mutex_enter(&dn->dn_mtx);
1772 space = DN_USED_BYTES(dn->dn_phys);
1773 if (delta > 0) {
1774 ASSERT3U(space + delta, >=, space); /* no overflow */
1775 } else {
1776 ASSERT3U(space, >=, -delta); /* no underflow */
1777 }
1778 space += delta;
1779 if (spa_version(dn->dn_objset->os_spa) < SPA_VERSION_DNODE_BYTES) {
1780 ASSERT((dn->dn_phys->dn_flags & DNODE_FLAG_USED_BYTES) == 0);
1781 ASSERT0(P2PHASE(space, 1<<DEV_BSHIFT));
1782 dn->dn_phys->dn_used = space >> DEV_BSHIFT;
1783 } else {
1784 dn->dn_phys->dn_used = space;
1785 dn->dn_phys->dn_flags |= DNODE_FLAG_USED_BYTES;
1786 }
1787 mutex_exit(&dn->dn_mtx);
1788 }
1789
1790 /*
1791 * Call when we think we're going to write/free space in open context to track
1792 * the amount of memory in use by the currently open txg.
1793 */
1794 void
1795 dnode_willuse_space(dnode_t *dn, int64_t space, dmu_tx_t *tx)
1796 {
1797 objset_t *os = dn->dn_objset;
1798 dsl_dataset_t *ds = os->os_dsl_dataset;
1799 int64_t aspace = spa_get_asize(os->os_spa, space);
1800
1801 if (ds != NULL) {
1802 dsl_dir_willuse_space(ds->ds_dir, aspace, tx);
1803 dsl_pool_dirty_space(dmu_tx_pool(tx), space, tx);
1804 }
1805
1806 dmu_tx_willuse_space(tx, aspace);
1807 }
1808
1809 /*
1810 * Scans a block at the indicated "level" looking for a hole or data,
1811 * depending on 'flags'.
1812 *
1813 * If level > 0, then we are scanning an indirect block looking at its
1814 * pointers. If level == 0, then we are looking at a block of dnodes.
1815 *
1816 * If we don't find what we are looking for in the block, we return ESRCH.
1817 * Otherwise, return with *offset pointing to the beginning (if searching
1818 * forwards) or end (if searching backwards) of the range covered by the
1819 * block pointer we matched on (or dnode).
1820 *
1821 * The basic search algorithm used below by dnode_next_offset() is to
1822 * use this function to search up the block tree (widen the search) until
1823 * we find something (i.e., we don't return ESRCH) and then search back
1824 * down the tree (narrow the search) until we reach our original search
1825 * level.
1826 */
1827 static int
1828 dnode_next_offset_level(dnode_t *dn, int flags, uint64_t *offset,
1829 int lvl, uint64_t blkfill, uint64_t txg)
1830 {
1831 dmu_buf_impl_t *db = NULL;
1832 void *data = NULL;
1833 uint64_t epbs = dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT;
1834 uint64_t epb = 1ULL << epbs;
1835 uint64_t minfill, maxfill;
1836 boolean_t hole;
1837 int i, inc, error, span;
1838
1839 dprintf("probing object %llu offset %llx level %d of %u\n",
1840 dn->dn_object, *offset, lvl, dn->dn_phys->dn_nlevels);
1841
1842 hole = ((flags & DNODE_FIND_HOLE) != 0);
1843 inc = (flags & DNODE_FIND_BACKWARDS) ? -1 : 1;
1844 ASSERT(txg == 0 || !hole);
1845
1846 if (lvl == dn->dn_phys->dn_nlevels) {
1847 error = 0;
1848 epb = dn->dn_phys->dn_nblkptr;
1849 data = dn->dn_phys->dn_blkptr;
1850 } else {
1851 uint64_t blkid = dbuf_whichblock(dn, *offset) >> (epbs * lvl);
1852 error = dbuf_hold_impl(dn, lvl, blkid, TRUE, FTAG, &db);
1853 if (error) {
1854 if (error != ENOENT)
1855 return (error);
1856 if (hole)
1857 return (0);
1858 /*
1859 * This can only happen when we are searching up
1860 * the block tree for data. We don't really need to
1861 * adjust the offset, as we will just end up looking
1862 * at the pointer to this block in its parent, and its
1863 * going to be unallocated, so we will skip over it.
1864 */
1865 return (SET_ERROR(ESRCH));
1866 }
1867 error = dbuf_read(db, NULL, DB_RF_CANFAIL | DB_RF_HAVESTRUCT);
1868 if (error) {
1869 dbuf_rele(db, FTAG);
1870 return (error);
1871 }
1872 data = db->db.db_data;
1873 }
1874
1875 if (db && txg &&
1876 (db->db_blkptr == NULL || db->db_blkptr->blk_birth <= txg)) {
1877 /*
1878 * This can only happen when we are searching up the tree
1879 * and these conditions mean that we need to keep climbing.
1880 */
1881 error = SET_ERROR(ESRCH);
1882 } else if (lvl == 0) {
1883 dnode_phys_t *dnp = data;
1884 span = DNODE_SHIFT;
1885 ASSERT(dn->dn_type == DMU_OT_DNODE);
1886
1887 for (i = (*offset >> span) & (blkfill - 1);
1888 i >= 0 && i < blkfill; i += inc) {
1889 if ((dnp[i].dn_type == DMU_OT_NONE) == hole)
1890 break;
1891 *offset += (1ULL << span) * inc;
1892 }
1893 if (i < 0 || i == blkfill)
1894 error = SET_ERROR(ESRCH);
1895 } else {
1896 blkptr_t *bp = data;
1897 uint64_t start = *offset;
1898 span = (lvl - 1) * epbs + dn->dn_datablkshift;
1899 minfill = 0;
1900 maxfill = blkfill << ((lvl - 1) * epbs);
1901
1902 if (hole)
1903 maxfill--;
1904 else
1905 minfill++;
1906
1907 *offset = *offset >> span;
1908 for (i = BF64_GET(*offset, 0, epbs);
1909 i >= 0 && i < epb; i += inc) {
1910 if (bp[i].blk_fill >= minfill &&
1911 bp[i].blk_fill <= maxfill &&
1912 (hole || bp[i].blk_birth > txg))
1913 break;
1914 if (inc > 0 || *offset > 0)
1915 *offset += inc;
1916 }
1917 *offset = *offset << span;
1918 if (inc < 0) {
1919 /* traversing backwards; position offset at the end */
1920 ASSERT3U(*offset, <=, start);
1921 *offset = MIN(*offset + (1ULL << span) - 1, start);
1922 } else if (*offset < start) {
1923 *offset = start;
1924 }
1925 if (i < 0 || i >= epb)
1926 error = SET_ERROR(ESRCH);
1927 }
1928
1929 if (db)
1930 dbuf_rele(db, FTAG);
1931
1932 return (error);
1933 }
1934
1935 /*
1936 * Find the next hole, data, or sparse region at or after *offset.
1937 * The value 'blkfill' tells us how many items we expect to find
1938 * in an L0 data block; this value is 1 for normal objects,
1939 * DNODES_PER_BLOCK for the meta dnode, and some fraction of
1940 * DNODES_PER_BLOCK when searching for sparse regions thereof.
1941 *
1942 * Examples:
1943 *
1944 * dnode_next_offset(dn, flags, offset, 1, 1, 0);
1945 * Finds the next/previous hole/data in a file.
1946 * Used in dmu_offset_next().
1947 *
1948 * dnode_next_offset(mdn, flags, offset, 0, DNODES_PER_BLOCK, txg);
1949 * Finds the next free/allocated dnode an objset's meta-dnode.
1950 * Only finds objects that have new contents since txg (ie.
1951 * bonus buffer changes and content removal are ignored).
1952 * Used in dmu_object_next().
1953 *
1954 * dnode_next_offset(mdn, DNODE_FIND_HOLE, offset, 2, DNODES_PER_BLOCK >> 2, 0);
1955 * Finds the next L2 meta-dnode bp that's at most 1/4 full.
1956 * Used in dmu_object_alloc().
1957 */
1958 int
1959 dnode_next_offset(dnode_t *dn, int flags, uint64_t *offset,
1960 int minlvl, uint64_t blkfill, uint64_t txg)
1961 {
1962 uint64_t initial_offset = *offset;
1963 int lvl, maxlvl;
1964 int error = 0;
1965
1966 if (!(flags & DNODE_FIND_HAVELOCK))
1967 rw_enter(&dn->dn_struct_rwlock, RW_READER);
1968
1969 if (dn->dn_phys->dn_nlevels == 0) {
1970 error = SET_ERROR(ESRCH);
1971 goto out;
1972 }
1973
1974 if (dn->dn_datablkshift == 0) {
1975 if (*offset < dn->dn_datablksz) {
1976 if (flags & DNODE_FIND_HOLE)
1977 *offset = dn->dn_datablksz;
1978 } else {
1979 error = SET_ERROR(ESRCH);
1980 }
1981 goto out;
1982 }
1983
1984 maxlvl = dn->dn_phys->dn_nlevels;
1985
1986 for (lvl = minlvl; lvl <= maxlvl; lvl++) {
1987 error = dnode_next_offset_level(dn,
1988 flags, offset, lvl, blkfill, txg);
1989 if (error != ESRCH)
1990 break;
1991 }
1992
1993 while (error == 0 && --lvl >= minlvl) {
1994 error = dnode_next_offset_level(dn,
1995 flags, offset, lvl, blkfill, txg);
1996 }
1997
1998 if (error == 0 && (flags & DNODE_FIND_BACKWARDS ?
1999 initial_offset < *offset : initial_offset > *offset))
2000 error = SET_ERROR(ESRCH);
2001 out:
2002 if (!(flags & DNODE_FIND_HAVELOCK))
2003 rw_exit(&dn->dn_struct_rwlock);
2004
2005 return (error);
2006 }