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