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1949 crash during reguid causes stale config
[unleashed.git] / usr / src / uts / common / fs / zfs / dnode.c
blob850dd5816bf32705408617d96363382e71f120ef
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 */
24
25 #include <sys/zfs_context.h>
26 #include <sys/dbuf.h>
27 #include <sys/dnode.h>
28 #include <sys/dmu.h>
29 #include <sys/dmu_impl.h>
30 #include <sys/dmu_tx.h>
31 #include <sys/dmu_objset.h>
32 #include <sys/dsl_dir.h>
33 #include <sys/dsl_dataset.h>
34 #include <sys/spa.h>
35 #include <sys/zio.h>
36 #include <sys/dmu_zfetch.h>
37
38 static int free_range_compar(const void *node1, const void *node2);
39
40 static kmem_cache_t *dnode_cache;
41 /*
42 * Define DNODE_STATS to turn on statistic gathering. By default, it is only
43 * turned on when DEBUG is also defined.
44 */
45 #ifdef DEBUG
46 #define DNODE_STATS
47 #endif /* DEBUG */
48
49 #ifdef DNODE_STATS
50 #define DNODE_STAT_ADD(stat) ((stat)++)
51 #else
52 #define DNODE_STAT_ADD(stat) /* nothing */
53 #endif /* DNODE_STATS */
54
55 static dnode_phys_t dnode_phys_zero;
56
57 int zfs_default_bs = SPA_MINBLOCKSHIFT;
58 int zfs_default_ibs = DN_MAX_INDBLKSHIFT;
59
60 static kmem_cbrc_t dnode_move(void *, void *, size_t, void *);
61
62 /* ARGSUSED */
63 static int
64 dnode_cons(void *arg, void *unused, int kmflag)
65 {
66 dnode_t *dn = arg;
67 int i;
68
69 rw_init(&dn->dn_struct_rwlock, NULL, RW_DEFAULT, NULL);
70 mutex_init(&dn->dn_mtx, NULL, MUTEX_DEFAULT, NULL);
71 mutex_init(&dn->dn_dbufs_mtx, NULL, MUTEX_DEFAULT, NULL);
72 cv_init(&dn->dn_notxholds, NULL, CV_DEFAULT, NULL);
73
74 refcount_create(&dn->dn_holds);
75 refcount_create(&dn->dn_tx_holds);
76 list_link_init(&dn->dn_link);
77
78 bzero(&dn->dn_next_nblkptr[0], sizeof (dn->dn_next_nblkptr));
79 bzero(&dn->dn_next_nlevels[0], sizeof (dn->dn_next_nlevels));
80 bzero(&dn->dn_next_indblkshift[0], sizeof (dn->dn_next_indblkshift));
81 bzero(&dn->dn_next_bonustype[0], sizeof (dn->dn_next_bonustype));
82 bzero(&dn->dn_rm_spillblk[0], sizeof (dn->dn_rm_spillblk));
83 bzero(&dn->dn_next_bonuslen[0], sizeof (dn->dn_next_bonuslen));
84 bzero(&dn->dn_next_blksz[0], sizeof (dn->dn_next_blksz));
85
86 for (i = 0; i < TXG_SIZE; i++) {
87 list_link_init(&dn->dn_dirty_link[i]);
88 avl_create(&dn->dn_ranges[i], free_range_compar,
89 sizeof (free_range_t),
90 offsetof(struct free_range, fr_node));
91 list_create(&dn->dn_dirty_records[i],
92 sizeof (dbuf_dirty_record_t),
93 offsetof(dbuf_dirty_record_t, dr_dirty_node));
94 }
95
96 dn->dn_allocated_txg = 0;
97 dn->dn_free_txg = 0;
98 dn->dn_assigned_txg = 0;
99 dn->dn_dirtyctx = 0;
100 dn->dn_dirtyctx_firstset = NULL;
101 dn->dn_bonus = NULL;
102 dn->dn_have_spill = B_FALSE;
103 dn->dn_zio = NULL;
104 dn->dn_oldused = 0;
105 dn->dn_oldflags = 0;
106 dn->dn_olduid = 0;
107 dn->dn_oldgid = 0;
108 dn->dn_newuid = 0;
109 dn->dn_newgid = 0;
110 dn->dn_id_flags = 0;
111
112 dn->dn_dbufs_count = 0;
113 list_create(&dn->dn_dbufs, sizeof (dmu_buf_impl_t),
114 offsetof(dmu_buf_impl_t, db_link));
115
116 dn->dn_moved = 0;
117 return (0);
118 }
119
120 /* ARGSUSED */
121 static void
122 dnode_dest(void *arg, void *unused)
123 {
124 int i;
125 dnode_t *dn = arg;
126
127 rw_destroy(&dn->dn_struct_rwlock);
128 mutex_destroy(&dn->dn_mtx);
129 mutex_destroy(&dn->dn_dbufs_mtx);
130 cv_destroy(&dn->dn_notxholds);
131 refcount_destroy(&dn->dn_holds);
132 refcount_destroy(&dn->dn_tx_holds);
133 ASSERT(!list_link_active(&dn->dn_link));
134
135 for (i = 0; i < TXG_SIZE; i++) {
136 ASSERT(!list_link_active(&dn->dn_dirty_link[i]));
137 avl_destroy(&dn->dn_ranges[i]);
138 list_destroy(&dn->dn_dirty_records[i]);
139 ASSERT3U(dn->dn_next_nblkptr[i], ==, 0);
140 ASSERT3U(dn->dn_next_nlevels[i], ==, 0);
141 ASSERT3U(dn->dn_next_indblkshift[i], ==, 0);
142 ASSERT3U(dn->dn_next_bonustype[i], ==, 0);
143 ASSERT3U(dn->dn_rm_spillblk[i], ==, 0);
144 ASSERT3U(dn->dn_next_bonuslen[i], ==, 0);
145 ASSERT3U(dn->dn_next_blksz[i], ==, 0);
146 }
147
148 ASSERT3U(dn->dn_allocated_txg, ==, 0);
149 ASSERT3U(dn->dn_free_txg, ==, 0);
150 ASSERT3U(dn->dn_assigned_txg, ==, 0);
151 ASSERT3U(dn->dn_dirtyctx, ==, 0);
152 ASSERT3P(dn->dn_dirtyctx_firstset, ==, NULL);
153 ASSERT3P(dn->dn_bonus, ==, NULL);
154 ASSERT(!dn->dn_have_spill);
155 ASSERT3P(dn->dn_zio, ==, NULL);
156 ASSERT3U(dn->dn_oldused, ==, 0);
157 ASSERT3U(dn->dn_oldflags, ==, 0);
158 ASSERT3U(dn->dn_olduid, ==, 0);
159 ASSERT3U(dn->dn_oldgid, ==, 0);
160 ASSERT3U(dn->dn_newuid, ==, 0);
161 ASSERT3U(dn->dn_newgid, ==, 0);
162 ASSERT3U(dn->dn_id_flags, ==, 0);
163
164 ASSERT3U(dn->dn_dbufs_count, ==, 0);
165 list_destroy(&dn->dn_dbufs);
166 }
167
168 void
169 dnode_init(void)
170 {
171 ASSERT(dnode_cache == NULL);
172 dnode_cache = kmem_cache_create("dnode_t",
173 sizeof (dnode_t),
174 0, dnode_cons, dnode_dest, NULL, NULL, NULL, 0);
175 kmem_cache_set_move(dnode_cache, dnode_move);
176 }
177
178 void
179 dnode_fini(void)
180 {
181 kmem_cache_destroy(dnode_cache);
182 dnode_cache = NULL;
183 }
184
185
186 #ifdef ZFS_DEBUG
187 void
188 dnode_verify(dnode_t *dn)
189 {
190 int drop_struct_lock = FALSE;
191
192 ASSERT(dn->dn_phys);
193 ASSERT(dn->dn_objset);
194 ASSERT(dn->dn_handle->dnh_dnode == dn);
195
196 ASSERT(dn->dn_phys->dn_type < DMU_OT_NUMTYPES);
197
198 if (!(zfs_flags & ZFS_DEBUG_DNODE_VERIFY))
199 return;
200
201 if (!RW_WRITE_HELD(&dn->dn_struct_rwlock)) {
202 rw_enter(&dn->dn_struct_rwlock, RW_READER);
203 drop_struct_lock = TRUE;
204 }
205 if (dn->dn_phys->dn_type != DMU_OT_NONE || dn->dn_allocated_txg != 0) {
206 int i;
207 ASSERT3U(dn->dn_indblkshift, >=, 0);
208 ASSERT3U(dn->dn_indblkshift, <=, SPA_MAXBLOCKSHIFT);
209 if (dn->dn_datablkshift) {
210 ASSERT3U(dn->dn_datablkshift, >=, SPA_MINBLOCKSHIFT);
211 ASSERT3U(dn->dn_datablkshift, <=, SPA_MAXBLOCKSHIFT);
212 ASSERT3U(1<<dn->dn_datablkshift, ==, dn->dn_datablksz);
213 }
214 ASSERT3U(dn->dn_nlevels, <=, 30);
215 ASSERT3U(dn->dn_type, <=, DMU_OT_NUMTYPES);
216 ASSERT3U(dn->dn_nblkptr, >=, 1);
217 ASSERT3U(dn->dn_nblkptr, <=, DN_MAX_NBLKPTR);
218 ASSERT3U(dn->dn_bonuslen, <=, DN_MAX_BONUSLEN);
219 ASSERT3U(dn->dn_datablksz, ==,
220 dn->dn_datablkszsec << SPA_MINBLOCKSHIFT);
221 ASSERT3U(ISP2(dn->dn_datablksz), ==, dn->dn_datablkshift != 0);
222 ASSERT3U((dn->dn_nblkptr - 1) * sizeof (blkptr_t) +
223 dn->dn_bonuslen, <=, DN_MAX_BONUSLEN);
224 for (i = 0; i < TXG_SIZE; i++) {
225 ASSERT3U(dn->dn_next_nlevels[i], <=, dn->dn_nlevels);
226 }
227 }
228 if (dn->dn_phys->dn_type != DMU_OT_NONE)
229 ASSERT3U(dn->dn_phys->dn_nlevels, <=, dn->dn_nlevels);
230 ASSERT(DMU_OBJECT_IS_SPECIAL(dn->dn_object) || dn->dn_dbuf != NULL);
231 if (dn->dn_dbuf != NULL) {
232 ASSERT3P(dn->dn_phys, ==,
233 (dnode_phys_t *)dn->dn_dbuf->db.db_data +
234 (dn->dn_object % (dn->dn_dbuf->db.db_size >> DNODE_SHIFT)));
235 }
236 if (drop_struct_lock)
237 rw_exit(&dn->dn_struct_rwlock);
238 }
239 #endif
240
241 void
242 dnode_byteswap(dnode_phys_t *dnp)
243 {
244 uint64_t *buf64 = (void*)&dnp->dn_blkptr;
245 int i;
246
247 if (dnp->dn_type == DMU_OT_NONE) {
248 bzero(dnp, sizeof (dnode_phys_t));
249 return;
250 }
251
252 dnp->dn_datablkszsec = BSWAP_16(dnp->dn_datablkszsec);
253 dnp->dn_bonuslen = BSWAP_16(dnp->dn_bonuslen);
254 dnp->dn_maxblkid = BSWAP_64(dnp->dn_maxblkid);
255 dnp->dn_used = BSWAP_64(dnp->dn_used);
256
257 /*
258 * dn_nblkptr is only one byte, so it's OK to read it in either
259 * byte order. We can't read dn_bouslen.
260 */
261 ASSERT(dnp->dn_indblkshift <= SPA_MAXBLOCKSHIFT);
262 ASSERT(dnp->dn_nblkptr <= DN_MAX_NBLKPTR);
263 for (i = 0; i < dnp->dn_nblkptr * sizeof (blkptr_t)/8; i++)
264 buf64[i] = BSWAP_64(buf64[i]);
265
266 /*
267 * OK to check dn_bonuslen for zero, because it won't matter if
268 * we have the wrong byte order. This is necessary because the
269 * dnode dnode is smaller than a regular dnode.
270 */
271 if (dnp->dn_bonuslen != 0) {
272 /*
273 * Note that the bonus length calculated here may be
274 * longer than the actual bonus buffer. This is because
275 * we always put the bonus buffer after the last block
276 * pointer (instead of packing it against the end of the
277 * dnode buffer).
278 */
279 int off = (dnp->dn_nblkptr-1) * sizeof (blkptr_t);
280 size_t len = DN_MAX_BONUSLEN - off;
281 ASSERT3U(dnp->dn_bonustype, <, DMU_OT_NUMTYPES);
282 dmu_ot[dnp->dn_bonustype].ot_byteswap(dnp->dn_bonus + off, len);
283 }
284
285 /* Swap SPILL block if we have one */
286 if (dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR)
287 byteswap_uint64_array(&dnp->dn_spill, sizeof (blkptr_t));
288
289 }
290
291 void
292 dnode_buf_byteswap(void *vbuf, size_t size)
293 {
294 dnode_phys_t *buf = vbuf;
295 int i;
296
297 ASSERT3U(sizeof (dnode_phys_t), ==, (1<<DNODE_SHIFT));
298 ASSERT((size & (sizeof (dnode_phys_t)-1)) == 0);
299
300 size >>= DNODE_SHIFT;
301 for (i = 0; i < size; i++) {
302 dnode_byteswap(buf);
303 buf++;
304 }
305 }
306
307 static int
308 free_range_compar(const void *node1, const void *node2)
309 {
310 const free_range_t *rp1 = node1;
311 const free_range_t *rp2 = node2;
312
313 if (rp1->fr_blkid < rp2->fr_blkid)
314 return (-1);
315 else if (rp1->fr_blkid > rp2->fr_blkid)
316 return (1);
317 else return (0);
318 }
319
320 void
321 dnode_setbonuslen(dnode_t *dn, int newsize, dmu_tx_t *tx)
322 {
323 ASSERT3U(refcount_count(&dn->dn_holds), >=, 1);
324
325 dnode_setdirty(dn, tx);
326 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
327 ASSERT3U(newsize, <=, DN_MAX_BONUSLEN -
328 (dn->dn_nblkptr-1) * sizeof (blkptr_t));
329 dn->dn_bonuslen = newsize;
330 if (newsize == 0)
331 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = DN_ZERO_BONUSLEN;
332 else
333 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = dn->dn_bonuslen;
334 rw_exit(&dn->dn_struct_rwlock);
335 }
336
337 void
338 dnode_setbonus_type(dnode_t *dn, dmu_object_type_t newtype, dmu_tx_t *tx)
339 {
340 ASSERT3U(refcount_count(&dn->dn_holds), >=, 1);
341 dnode_setdirty(dn, tx);
342 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
343 dn->dn_bonustype = newtype;
344 dn->dn_next_bonustype[tx->tx_txg & TXG_MASK] = dn->dn_bonustype;
345 rw_exit(&dn->dn_struct_rwlock);
346 }
347
348 void
349 dnode_rm_spill(dnode_t *dn, dmu_tx_t *tx)
350 {
351 ASSERT3U(refcount_count(&dn->dn_holds), >=, 1);
352 ASSERT(RW_WRITE_HELD(&dn->dn_struct_rwlock));
353 dnode_setdirty(dn, tx);
354 dn->dn_rm_spillblk[tx->tx_txg&TXG_MASK] = DN_KILL_SPILLBLK;
355 dn->dn_have_spill = B_FALSE;
356 }
357
358 static void
359 dnode_setdblksz(dnode_t *dn, int size)
360 {
361 ASSERT3U(P2PHASE(size, SPA_MINBLOCKSIZE), ==, 0);
362 ASSERT3U(size, <=, SPA_MAXBLOCKSIZE);
363 ASSERT3U(size, >=, SPA_MINBLOCKSIZE);
364 ASSERT3U(size >> SPA_MINBLOCKSHIFT, <,
365 1<<(sizeof (dn->dn_phys->dn_datablkszsec) * 8));
366 dn->dn_datablksz = size;
367 dn->dn_datablkszsec = size >> SPA_MINBLOCKSHIFT;
368 dn->dn_datablkshift = ISP2(size) ? highbit(size - 1) : 0;
369 }
370
371 static dnode_t *
372 dnode_create(objset_t *os, dnode_phys_t *dnp, dmu_buf_impl_t *db,
373 uint64_t object, dnode_handle_t *dnh)
374 {
375 dnode_t *dn = kmem_cache_alloc(dnode_cache, KM_SLEEP);
376
377 ASSERT(!POINTER_IS_VALID(dn->dn_objset));
378 dn->dn_moved = 0;
379
380 /*
381 * Defer setting dn_objset until the dnode is ready to be a candidate
382 * for the dnode_move() callback.
383 */
384 dn->dn_object = object;
385 dn->dn_dbuf = db;
386 dn->dn_handle = dnh;
387 dn->dn_phys = dnp;
388
389 if (dnp->dn_datablkszsec) {
390 dnode_setdblksz(dn, dnp->dn_datablkszsec << SPA_MINBLOCKSHIFT);
391 } else {
392 dn->dn_datablksz = 0;
393 dn->dn_datablkszsec = 0;
394 dn->dn_datablkshift = 0;
395 }
396 dn->dn_indblkshift = dnp->dn_indblkshift;
397 dn->dn_nlevels = dnp->dn_nlevels;
398 dn->dn_type = dnp->dn_type;
399 dn->dn_nblkptr = dnp->dn_nblkptr;
400 dn->dn_checksum = dnp->dn_checksum;
401 dn->dn_compress = dnp->dn_compress;
402 dn->dn_bonustype = dnp->dn_bonustype;
403 dn->dn_bonuslen = dnp->dn_bonuslen;
404 dn->dn_maxblkid = dnp->dn_maxblkid;
405 dn->dn_have_spill = ((dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) != 0);
406 dn->dn_id_flags = 0;
407
408 dmu_zfetch_init(&dn->dn_zfetch, dn);
409
410 ASSERT(dn->dn_phys->dn_type < DMU_OT_NUMTYPES);
411
412 mutex_enter(&os->os_lock);
413 list_insert_head(&os->os_dnodes, dn);
414 membar_producer();
415 /*
416 * Everything else must be valid before assigning dn_objset makes the
417 * dnode eligible for dnode_move().
418 */
419 dn->dn_objset = os;
420 mutex_exit(&os->os_lock);
421
422 arc_space_consume(sizeof (dnode_t), ARC_SPACE_OTHER);
423 return (dn);
424 }
425
426 /*
427 * Caller must be holding the dnode handle, which is released upon return.
428 */
429 static void
430 dnode_destroy(dnode_t *dn)
431 {
432 objset_t *os = dn->dn_objset;
433
434 ASSERT((dn->dn_id_flags & DN_ID_NEW_EXIST) == 0);
435
436 mutex_enter(&os->os_lock);
437 POINTER_INVALIDATE(&dn->dn_objset);
438 list_remove(&os->os_dnodes, dn);
439 mutex_exit(&os->os_lock);
440
441 /* the dnode can no longer move, so we can release the handle */
442 zrl_remove(&dn->dn_handle->dnh_zrlock);
443
444 dn->dn_allocated_txg = 0;
445 dn->dn_free_txg = 0;
446 dn->dn_assigned_txg = 0;
447
448 dn->dn_dirtyctx = 0;
449 if (dn->dn_dirtyctx_firstset != NULL) {
450 kmem_free(dn->dn_dirtyctx_firstset, 1);
451 dn->dn_dirtyctx_firstset = NULL;
452 }
453 if (dn->dn_bonus != NULL) {
454 mutex_enter(&dn->dn_bonus->db_mtx);
455 dbuf_evict(dn->dn_bonus);
456 dn->dn_bonus = NULL;
457 }
458 dn->dn_zio = NULL;
459
460 dn->dn_have_spill = B_FALSE;
461 dn->dn_oldused = 0;
462 dn->dn_oldflags = 0;
463 dn->dn_olduid = 0;
464 dn->dn_oldgid = 0;
465 dn->dn_newuid = 0;
466 dn->dn_newgid = 0;
467 dn->dn_id_flags = 0;
468
469 dmu_zfetch_rele(&dn->dn_zfetch);
470 kmem_cache_free(dnode_cache, dn);
471 arc_space_return(sizeof (dnode_t), ARC_SPACE_OTHER);
472 }
473
474 void
475 dnode_allocate(dnode_t *dn, dmu_object_type_t ot, int blocksize, int ibs,
476 dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx)
477 {
478 int i;
479
480 if (blocksize == 0)
481 blocksize = 1 << zfs_default_bs;
482 else if (blocksize > SPA_MAXBLOCKSIZE)
483 blocksize = SPA_MAXBLOCKSIZE;
484 else
485 blocksize = P2ROUNDUP(blocksize, SPA_MINBLOCKSIZE);
486
487 if (ibs == 0)
488 ibs = zfs_default_ibs;
489
490 ibs = MIN(MAX(ibs, DN_MIN_INDBLKSHIFT), DN_MAX_INDBLKSHIFT);
491
492 dprintf("os=%p obj=%llu txg=%llu blocksize=%d ibs=%d\n", dn->dn_objset,
493 dn->dn_object, tx->tx_txg, blocksize, ibs);
494
495 ASSERT(dn->dn_type == DMU_OT_NONE);
496 ASSERT(bcmp(dn->dn_phys, &dnode_phys_zero, sizeof (dnode_phys_t)) == 0);
497 ASSERT(dn->dn_phys->dn_type == DMU_OT_NONE);
498 ASSERT(ot != DMU_OT_NONE);
499 ASSERT3U(ot, <, DMU_OT_NUMTYPES);
500 ASSERT((bonustype == DMU_OT_NONE && bonuslen == 0) ||
501 (bonustype == DMU_OT_SA && bonuslen == 0) ||
502 (bonustype != DMU_OT_NONE && bonuslen != 0));
503 ASSERT3U(bonustype, <, DMU_OT_NUMTYPES);
504 ASSERT3U(bonuslen, <=, DN_MAX_BONUSLEN);
505 ASSERT(dn->dn_type == DMU_OT_NONE);
506 ASSERT3U(dn->dn_maxblkid, ==, 0);
507 ASSERT3U(dn->dn_allocated_txg, ==, 0);
508 ASSERT3U(dn->dn_assigned_txg, ==, 0);
509 ASSERT(refcount_is_zero(&dn->dn_tx_holds));
510 ASSERT3U(refcount_count(&dn->dn_holds), <=, 1);
511 ASSERT3P(list_head(&dn->dn_dbufs), ==, NULL);
512
513 for (i = 0; i < TXG_SIZE; i++) {
514 ASSERT3U(dn->dn_next_nblkptr[i], ==, 0);
515 ASSERT3U(dn->dn_next_nlevels[i], ==, 0);
516 ASSERT3U(dn->dn_next_indblkshift[i], ==, 0);
517 ASSERT3U(dn->dn_next_bonuslen[i], ==, 0);
518 ASSERT3U(dn->dn_next_bonustype[i], ==, 0);
519 ASSERT3U(dn->dn_rm_spillblk[i], ==, 0);
520 ASSERT3U(dn->dn_next_blksz[i], ==, 0);
521 ASSERT(!list_link_active(&dn->dn_dirty_link[i]));
522 ASSERT3P(list_head(&dn->dn_dirty_records[i]), ==, NULL);
523 ASSERT3U(avl_numnodes(&dn->dn_ranges[i]), ==, 0);
524 }
525
526 dn->dn_type = ot;
527 dnode_setdblksz(dn, blocksize);
528 dn->dn_indblkshift = ibs;
529 dn->dn_nlevels = 1;
530 if (bonustype == DMU_OT_SA) /* Maximize bonus space for SA */
531 dn->dn_nblkptr = 1;
532 else
533 dn->dn_nblkptr = 1 +
534 ((DN_MAX_BONUSLEN - bonuslen) >> SPA_BLKPTRSHIFT);
535 dn->dn_bonustype = bonustype;
536 dn->dn_bonuslen = bonuslen;
537 dn->dn_checksum = ZIO_CHECKSUM_INHERIT;
538 dn->dn_compress = ZIO_COMPRESS_INHERIT;
539 dn->dn_dirtyctx = 0;
540
541 dn->dn_free_txg = 0;
542 if (dn->dn_dirtyctx_firstset) {
543 kmem_free(dn->dn_dirtyctx_firstset, 1);
544 dn->dn_dirtyctx_firstset = NULL;
545 }
546
547 dn->dn_allocated_txg = tx->tx_txg;
548 dn->dn_id_flags = 0;
549
550 dnode_setdirty(dn, tx);
551 dn->dn_next_indblkshift[tx->tx_txg & TXG_MASK] = ibs;
552 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = dn->dn_bonuslen;
553 dn->dn_next_bonustype[tx->tx_txg & TXG_MASK] = dn->dn_bonustype;
554 dn->dn_next_blksz[tx->tx_txg & TXG_MASK] = dn->dn_datablksz;
555 }
556
557 void
558 dnode_reallocate(dnode_t *dn, dmu_object_type_t ot, int blocksize,
559 dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx)
560 {
561 int nblkptr;
562
563 ASSERT3U(blocksize, >=, SPA_MINBLOCKSIZE);
564 ASSERT3U(blocksize, <=, SPA_MAXBLOCKSIZE);
565 ASSERT3U(blocksize % SPA_MINBLOCKSIZE, ==, 0);
566 ASSERT(dn->dn_object != DMU_META_DNODE_OBJECT || dmu_tx_private_ok(tx));
567 ASSERT(tx->tx_txg != 0);
568 ASSERT((bonustype == DMU_OT_NONE && bonuslen == 0) ||
569 (bonustype != DMU_OT_NONE && bonuslen != 0) ||
570 (bonustype == DMU_OT_SA && bonuslen == 0));
571 ASSERT3U(bonustype, <, DMU_OT_NUMTYPES);
572 ASSERT3U(bonuslen, <=, DN_MAX_BONUSLEN);
573
574 /* clean up any unreferenced dbufs */
575 dnode_evict_dbufs(dn);
576
577 dn->dn_id_flags = 0;
578
579 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
580 dnode_setdirty(dn, tx);
581 if (dn->dn_datablksz != blocksize) {
582 /* change blocksize */
583 ASSERT(dn->dn_maxblkid == 0 &&
584 (BP_IS_HOLE(&dn->dn_phys->dn_blkptr[0]) ||
585 dnode_block_freed(dn, 0)));
586 dnode_setdblksz(dn, blocksize);
587 dn->dn_next_blksz[tx->tx_txg&TXG_MASK] = blocksize;
588 }
589 if (dn->dn_bonuslen != bonuslen)
590 dn->dn_next_bonuslen[tx->tx_txg&TXG_MASK] = bonuslen;
591
592 if (bonustype == DMU_OT_SA) /* Maximize bonus space for SA */
593 nblkptr = 1;
594 else
595 nblkptr = 1 + ((DN_MAX_BONUSLEN - bonuslen) >> SPA_BLKPTRSHIFT);
596 if (dn->dn_bonustype != bonustype)
597 dn->dn_next_bonustype[tx->tx_txg&TXG_MASK] = bonustype;
598 if (dn->dn_nblkptr != nblkptr)
599 dn->dn_next_nblkptr[tx->tx_txg&TXG_MASK] = nblkptr;
600 if (dn->dn_phys->dn_flags & DNODE_FLAG_SPILL_BLKPTR) {
601 dbuf_rm_spill(dn, tx);
602 dnode_rm_spill(dn, tx);
603 }
604 rw_exit(&dn->dn_struct_rwlock);
605
606 /* change type */
607 dn->dn_type = ot;
608
609 /* change bonus size and type */
610 mutex_enter(&dn->dn_mtx);
611 dn->dn_bonustype = bonustype;
612 dn->dn_bonuslen = bonuslen;
613 dn->dn_nblkptr = nblkptr;
614 dn->dn_checksum = ZIO_CHECKSUM_INHERIT;
615 dn->dn_compress = ZIO_COMPRESS_INHERIT;
616 ASSERT3U(dn->dn_nblkptr, <=, DN_MAX_NBLKPTR);
617
618 /* fix up the bonus db_size */
619 if (dn->dn_bonus) {
620 dn->dn_bonus->db.db_size =
621 DN_MAX_BONUSLEN - (dn->dn_nblkptr-1) * sizeof (blkptr_t);
622 ASSERT(dn->dn_bonuslen <= dn->dn_bonus->db.db_size);
623 }
624
625 dn->dn_allocated_txg = tx->tx_txg;
626 mutex_exit(&dn->dn_mtx);
627 }
628
629 #ifdef DNODE_STATS
630 static struct {
631 uint64_t dms_dnode_invalid;
632 uint64_t dms_dnode_recheck1;
633 uint64_t dms_dnode_recheck2;
634 uint64_t dms_dnode_special;
635 uint64_t dms_dnode_handle;
636 uint64_t dms_dnode_rwlock;
637 uint64_t dms_dnode_active;
638 } dnode_move_stats;
639 #endif /* DNODE_STATS */
640
641 static void
642 dnode_move_impl(dnode_t *odn, dnode_t *ndn)
643 {
644 int i;
645
646 ASSERT(!RW_LOCK_HELD(&odn->dn_struct_rwlock));
647 ASSERT(MUTEX_NOT_HELD(&odn->dn_mtx));
648 ASSERT(MUTEX_NOT_HELD(&odn->dn_dbufs_mtx));
649 ASSERT(!RW_LOCK_HELD(&odn->dn_zfetch.zf_rwlock));
650
651 /* Copy fields. */
652 ndn->dn_objset = odn->dn_objset;
653 ndn->dn_object = odn->dn_object;
654 ndn->dn_dbuf = odn->dn_dbuf;
655 ndn->dn_handle = odn->dn_handle;
656 ndn->dn_phys = odn->dn_phys;
657 ndn->dn_type = odn->dn_type;
658 ndn->dn_bonuslen = odn->dn_bonuslen;
659 ndn->dn_bonustype = odn->dn_bonustype;
660 ndn->dn_nblkptr = odn->dn_nblkptr;
661 ndn->dn_checksum = odn->dn_checksum;
662 ndn->dn_compress = odn->dn_compress;
663 ndn->dn_nlevels = odn->dn_nlevels;
664 ndn->dn_indblkshift = odn->dn_indblkshift;
665 ndn->dn_datablkshift = odn->dn_datablkshift;
666 ndn->dn_datablkszsec = odn->dn_datablkszsec;
667 ndn->dn_datablksz = odn->dn_datablksz;
668 ndn->dn_maxblkid = odn->dn_maxblkid;
669 bcopy(&odn->dn_next_nblkptr[0], &ndn->dn_next_nblkptr[0],
670 sizeof (odn->dn_next_nblkptr));
671 bcopy(&odn->dn_next_nlevels[0], &ndn->dn_next_nlevels[0],
672 sizeof (odn->dn_next_nlevels));
673 bcopy(&odn->dn_next_indblkshift[0], &ndn->dn_next_indblkshift[0],
674 sizeof (odn->dn_next_indblkshift));
675 bcopy(&odn->dn_next_bonustype[0], &ndn->dn_next_bonustype[0],
676 sizeof (odn->dn_next_bonustype));
677 bcopy(&odn->dn_rm_spillblk[0], &ndn->dn_rm_spillblk[0],
678 sizeof (odn->dn_rm_spillblk));
679 bcopy(&odn->dn_next_bonuslen[0], &ndn->dn_next_bonuslen[0],
680 sizeof (odn->dn_next_bonuslen));
681 bcopy(&odn->dn_next_blksz[0], &ndn->dn_next_blksz[0],
682 sizeof (odn->dn_next_blksz));
683 for (i = 0; i < TXG_SIZE; i++) {
684 list_move_tail(&ndn->dn_dirty_records[i],
685 &odn->dn_dirty_records[i]);
686 }
687 bcopy(&odn->dn_ranges[0], &ndn->dn_ranges[0], sizeof (odn->dn_ranges));
688 ndn->dn_allocated_txg = odn->dn_allocated_txg;
689 ndn->dn_free_txg = odn->dn_free_txg;
690 ndn->dn_assigned_txg = odn->dn_assigned_txg;
691 ndn->dn_dirtyctx = odn->dn_dirtyctx;
692 ndn->dn_dirtyctx_firstset = odn->dn_dirtyctx_firstset;
693 ASSERT(refcount_count(&odn->dn_tx_holds) == 0);
694 refcount_transfer(&ndn->dn_holds, &odn->dn_holds);
695 ASSERT(list_is_empty(&ndn->dn_dbufs));
696 list_move_tail(&ndn->dn_dbufs, &odn->dn_dbufs);
697 ndn->dn_dbufs_count = odn->dn_dbufs_count;
698 ndn->dn_bonus = odn->dn_bonus;
699 ndn->dn_have_spill = odn->dn_have_spill;
700 ndn->dn_zio = odn->dn_zio;
701 ndn->dn_oldused = odn->dn_oldused;
702 ndn->dn_oldflags = odn->dn_oldflags;
703 ndn->dn_olduid = odn->dn_olduid;
704 ndn->dn_oldgid = odn->dn_oldgid;
705 ndn->dn_newuid = odn->dn_newuid;
706 ndn->dn_newgid = odn->dn_newgid;
707 ndn->dn_id_flags = odn->dn_id_flags;
708 dmu_zfetch_init(&ndn->dn_zfetch, NULL);
709 list_move_tail(&ndn->dn_zfetch.zf_stream, &odn->dn_zfetch.zf_stream);
710 ndn->dn_zfetch.zf_dnode = odn->dn_zfetch.zf_dnode;
711 ndn->dn_zfetch.zf_stream_cnt = odn->dn_zfetch.zf_stream_cnt;
712 ndn->dn_zfetch.zf_alloc_fail = odn->dn_zfetch.zf_alloc_fail;
713
714 /*
715 * Update back pointers. Updating the handle fixes the back pointer of
716 * every descendant dbuf as well as the bonus dbuf.
717 */
718 ASSERT(ndn->dn_handle->dnh_dnode == odn);
719 ndn->dn_handle->dnh_dnode = ndn;
720 if (ndn->dn_zfetch.zf_dnode == odn) {
721 ndn->dn_zfetch.zf_dnode = ndn;
722 }
723
724 /*
725 * Invalidate the original dnode by clearing all of its back pointers.
726 */
727 odn->dn_dbuf = NULL;
728 odn->dn_handle = NULL;
729 list_create(&odn->dn_dbufs, sizeof (dmu_buf_impl_t),
730 offsetof(dmu_buf_impl_t, db_link));
731 odn->dn_dbufs_count = 0;
732 odn->dn_bonus = NULL;
733 odn->dn_zfetch.zf_dnode = NULL;
734
735 /*
736 * Set the low bit of the objset pointer to ensure that dnode_move()
737 * recognizes the dnode as invalid in any subsequent callback.
738 */
739 POINTER_INVALIDATE(&odn->dn_objset);
740
741 /*
742 * Satisfy the destructor.
743 */
744 for (i = 0; i < TXG_SIZE; i++) {
745 list_create(&odn->dn_dirty_records[i],
746 sizeof (dbuf_dirty_record_t),
747 offsetof(dbuf_dirty_record_t, dr_dirty_node));
748 odn->dn_ranges[i].avl_root = NULL;
749 odn->dn_ranges[i].avl_numnodes = 0;
750 odn->dn_next_nlevels[i] = 0;
751 odn->dn_next_indblkshift[i] = 0;
752 odn->dn_next_bonustype[i] = 0;
753 odn->dn_rm_spillblk[i] = 0;
754 odn->dn_next_bonuslen[i] = 0;
755 odn->dn_next_blksz[i] = 0;
756 }
757 odn->dn_allocated_txg = 0;
758 odn->dn_free_txg = 0;
759 odn->dn_assigned_txg = 0;
760 odn->dn_dirtyctx = 0;
761 odn->dn_dirtyctx_firstset = NULL;
762 odn->dn_have_spill = B_FALSE;
763 odn->dn_zio = NULL;
764 odn->dn_oldused = 0;
765 odn->dn_oldflags = 0;
766 odn->dn_olduid = 0;
767 odn->dn_oldgid = 0;
768 odn->dn_newuid = 0;
769 odn->dn_newgid = 0;
770 odn->dn_id_flags = 0;
771
772 /*
773 * Mark the dnode.
774 */
775 ndn->dn_moved = 1;
776 odn->dn_moved = (uint8_t)-1;
777 }
778
779 #ifdef _KERNEL
780 /*ARGSUSED*/
781 static kmem_cbrc_t
782 dnode_move(void *buf, void *newbuf, size_t size, void *arg)
783 {
784 dnode_t *odn = buf, *ndn = newbuf;
785 objset_t *os;
786 int64_t refcount;
787 uint32_t dbufs;
788
789 /*
790 * The dnode is on the objset's list of known dnodes if the objset
791 * pointer is valid. We set the low bit of the objset pointer when
792 * freeing the dnode to invalidate it, and the memory patterns written
793 * by kmem (baddcafe and deadbeef) set at least one of the two low bits.
794 * A newly created dnode sets the objset pointer last of all to indicate
795 * that the dnode is known and in a valid state to be moved by this
796 * function.
797 */
798 os = odn->dn_objset;
799 if (!POINTER_IS_VALID(os)) {
800 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_invalid);
801 return (KMEM_CBRC_DONT_KNOW);
802 }
803
804 /*
805 * Ensure that the objset does not go away during the move.
806 */
807 rw_enter(&os_lock, RW_WRITER);
808 if (os != odn->dn_objset) {
809 rw_exit(&os_lock);
810 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_recheck1);
811 return (KMEM_CBRC_DONT_KNOW);
812 }
813
814 /*
815 * If the dnode is still valid, then so is the objset. We know that no
816 * valid objset can be freed while we hold os_lock, so we can safely
817 * ensure that the objset remains in use.
818 */
819 mutex_enter(&os->os_lock);
820
821 /*
822 * Recheck the objset pointer in case the dnode was removed just before
823 * acquiring the lock.
824 */
825 if (os != odn->dn_objset) {
826 mutex_exit(&os->os_lock);
827 rw_exit(&os_lock);
828 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_recheck2);
829 return (KMEM_CBRC_DONT_KNOW);
830 }
831
832 /*
833 * At this point we know that as long as we hold os->os_lock, the dnode
834 * cannot be freed and fields within the dnode can be safely accessed.
835 * The objset listing this dnode cannot go away as long as this dnode is
836 * on its list.
837 */
838 rw_exit(&os_lock);
839 if (DMU_OBJECT_IS_SPECIAL(odn->dn_object)) {
840 mutex_exit(&os->os_lock);
841 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_special);
842 return (KMEM_CBRC_NO);
843 }
844 ASSERT(odn->dn_dbuf != NULL); /* only "special" dnodes have no parent */
845
846 /*
847 * Lock the dnode handle to prevent the dnode from obtaining any new
848 * holds. This also prevents the descendant dbufs and the bonus dbuf
849 * from accessing the dnode, so that we can discount their holds. The
850 * handle is safe to access because we know that while the dnode cannot
851 * go away, neither can its handle. Once we hold dnh_zrlock, we can
852 * safely move any dnode referenced only by dbufs.
853 */
854 if (!zrl_tryenter(&odn->dn_handle->dnh_zrlock)) {
855 mutex_exit(&os->os_lock);
856 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_handle);
857 return (KMEM_CBRC_LATER);
858 }
859
860 /*
861 * Ensure a consistent view of the dnode's holds and the dnode's dbufs.
862 * We need to guarantee that there is a hold for every dbuf in order to
863 * determine whether the dnode is actively referenced. Falsely matching
864 * a dbuf to an active hold would lead to an unsafe move. It's possible
865 * that a thread already having an active dnode hold is about to add a
866 * dbuf, and we can't compare hold and dbuf counts while the add is in
867 * progress.
868 */
869 if (!rw_tryenter(&odn->dn_struct_rwlock, RW_WRITER)) {
870 zrl_exit(&odn->dn_handle->dnh_zrlock);
871 mutex_exit(&os->os_lock);
872 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_rwlock);
873 return (KMEM_CBRC_LATER);
874 }
875
876 /*
877 * A dbuf may be removed (evicted) without an active dnode hold. In that
878 * case, the dbuf count is decremented under the handle lock before the
879 * dbuf's hold is released. This order ensures that if we count the hold
880 * after the dbuf is removed but before its hold is released, we will
881 * treat the unmatched hold as active and exit safely. If we count the
882 * hold before the dbuf is removed, the hold is discounted, and the
883 * removal is blocked until the move completes.
884 */
885 refcount = refcount_count(&odn->dn_holds);
886 ASSERT(refcount >= 0);
887 dbufs = odn->dn_dbufs_count;
888
889 /* We can't have more dbufs than dnode holds. */
890 ASSERT3U(dbufs, <=, refcount);
891 DTRACE_PROBE3(dnode__move, dnode_t *, odn, int64_t, refcount,
892 uint32_t, dbufs);
893
894 if (refcount > dbufs) {
895 rw_exit(&odn->dn_struct_rwlock);
896 zrl_exit(&odn->dn_handle->dnh_zrlock);
897 mutex_exit(&os->os_lock);
898 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_active);
899 return (KMEM_CBRC_LATER);
900 }
901
902 rw_exit(&odn->dn_struct_rwlock);
903
904 /*
905 * At this point we know that anyone with a hold on the dnode is not
906 * actively referencing it. The dnode is known and in a valid state to
907 * move. We're holding the locks needed to execute the critical section.
908 */
909 dnode_move_impl(odn, ndn);
910
911 list_link_replace(&odn->dn_link, &ndn->dn_link);
912 /* If the dnode was safe to move, the refcount cannot have changed. */
913 ASSERT(refcount == refcount_count(&ndn->dn_holds));
914 ASSERT(dbufs == ndn->dn_dbufs_count);
915 zrl_exit(&ndn->dn_handle->dnh_zrlock); /* handle has moved */
916 mutex_exit(&os->os_lock);
917
918 return (KMEM_CBRC_YES);
919 }
920 #endif /* _KERNEL */
921
922 void
923 dnode_special_close(dnode_handle_t *dnh)
924 {
925 dnode_t *dn = dnh->dnh_dnode;
926
927 /*
928 * Wait for final references to the dnode to clear. This can
929 * only happen if the arc is asyncronously evicting state that
930 * has a hold on this dnode while we are trying to evict this
931 * dnode.
932 */
933 while (refcount_count(&dn->dn_holds) > 0)
934 delay(1);
935 zrl_add(&dnh->dnh_zrlock);
936 dnode_destroy(dn); /* implicit zrl_remove() */
937 zrl_destroy(&dnh->dnh_zrlock);
938 dnh->dnh_dnode = NULL;
939 }
940
941 dnode_t *
942 dnode_special_open(objset_t *os, dnode_phys_t *dnp, uint64_t object,
943 dnode_handle_t *dnh)
944 {
945 dnode_t *dn = dnode_create(os, dnp, NULL, object, dnh);
946 dnh->dnh_dnode = dn;
947 zrl_init(&dnh->dnh_zrlock);
948 DNODE_VERIFY(dn);
949 return (dn);
950 }
951
952 static void
953 dnode_buf_pageout(dmu_buf_t *db, void *arg)
954 {
955 dnode_children_t *children_dnodes = arg;
956 int i;
957 int epb = db->db_size >> DNODE_SHIFT;
958
959 ASSERT(epb == children_dnodes->dnc_count);
960
961 for (i = 0; i < epb; i++) {
962 dnode_handle_t *dnh = &children_dnodes->dnc_children[i];
963 dnode_t *dn;
964
965 /*
966 * The dnode handle lock guards against the dnode moving to
967 * another valid address, so there is no need here to guard
968 * against changes to or from NULL.
969 */
970 if (dnh->dnh_dnode == NULL) {
971 zrl_destroy(&dnh->dnh_zrlock);
972 continue;
973 }
974
975 zrl_add(&dnh->dnh_zrlock);
976 dn = dnh->dnh_dnode;
977 /*
978 * If there are holds on this dnode, then there should
979 * be holds on the dnode's containing dbuf as well; thus
980 * it wouldn't be eligible for eviction and this function
981 * would not have been called.
982 */
983 ASSERT(refcount_is_zero(&dn->dn_holds));
984 ASSERT(refcount_is_zero(&dn->dn_tx_holds));
985
986 dnode_destroy(dn); /* implicit zrl_remove() */
987 zrl_destroy(&dnh->dnh_zrlock);
988 dnh->dnh_dnode = NULL;
989 }
990 kmem_free(children_dnodes, sizeof (dnode_children_t) +
991 (epb - 1) * sizeof (dnode_handle_t));
992 }
993
994 /*
995 * errors:
996 * EINVAL - invalid object number.
997 * EIO - i/o error.
998 * succeeds even for free dnodes.
999 */
1000 int
1001 dnode_hold_impl(objset_t *os, uint64_t object, int flag,
1002 void *tag, dnode_t **dnp)
1003 {
1004 int epb, idx, err;
1005 int drop_struct_lock = FALSE;
1006 int type;
1007 uint64_t blk;
1008 dnode_t *mdn, *dn;
1009 dmu_buf_impl_t *db;
1010 dnode_children_t *children_dnodes;
1011 dnode_handle_t *dnh;
1012
1013 /*
1014 * If you are holding the spa config lock as writer, you shouldn't
1015 * be asking the DMU to do *anything* unless it's the root pool
1016 * which may require us to read from the root filesystem while
1017 * holding some (not all) of the locks as writer.
1018 */
1019 ASSERT(spa_config_held(os->os_spa, SCL_ALL, RW_WRITER) == 0 ||
1020 (spa_is_root(os->os_spa) &&
1021 spa_config_held(os->os_spa, SCL_STATE, RW_WRITER)));
1022
1023 if (object == DMU_USERUSED_OBJECT || object == DMU_GROUPUSED_OBJECT) {
1024 dn = (object == DMU_USERUSED_OBJECT) ?
1025 DMU_USERUSED_DNODE(os) : DMU_GROUPUSED_DNODE(os);
1026 if (dn == NULL)
1027 return (ENOENT);
1028 type = dn->dn_type;
1029 if ((flag & DNODE_MUST_BE_ALLOCATED) && type == DMU_OT_NONE)
1030 return (ENOENT);
1031 if ((flag & DNODE_MUST_BE_FREE) && type != DMU_OT_NONE)
1032 return (EEXIST);
1033 DNODE_VERIFY(dn);
1034 (void) refcount_add(&dn->dn_holds, tag);
1035 *dnp = dn;
1036 return (0);
1037 }
1038
1039 if (object == 0 || object >= DN_MAX_OBJECT)
1040 return (EINVAL);
1041
1042 mdn = DMU_META_DNODE(os);
1043 ASSERT(mdn->dn_object == DMU_META_DNODE_OBJECT);
1044
1045 DNODE_VERIFY(mdn);
1046
1047 if (!RW_WRITE_HELD(&mdn->dn_struct_rwlock)) {
1048 rw_enter(&mdn->dn_struct_rwlock, RW_READER);
1049 drop_struct_lock = TRUE;
1050 }
1051
1052 blk = dbuf_whichblock(mdn, object * sizeof (dnode_phys_t));
1053
1054 db = dbuf_hold(mdn, blk, FTAG);
1055 if (drop_struct_lock)
1056 rw_exit(&mdn->dn_struct_rwlock);
1057 if (db == NULL)
1058 return (EIO);
1059 err = dbuf_read(db, NULL, DB_RF_CANFAIL);
1060 if (err) {
1061 dbuf_rele(db, FTAG);
1062 return (err);
1063 }
1064
1065 ASSERT3U(db->db.db_size, >=, 1<<DNODE_SHIFT);
1066 epb = db->db.db_size >> DNODE_SHIFT;
1067
1068 idx = object & (epb-1);
1069
1070 ASSERT(DB_DNODE(db)->dn_type == DMU_OT_DNODE);
1071 children_dnodes = dmu_buf_get_user(&db->db);
1072 if (children_dnodes == NULL) {
1073 int i;
1074 dnode_children_t *winner;
1075 children_dnodes = kmem_alloc(sizeof (dnode_children_t) +
1076 (epb - 1) * sizeof (dnode_handle_t), KM_SLEEP);
1077 children_dnodes->dnc_count = epb;
1078 dnh = &children_dnodes->dnc_children[0];
1079 for (i = 0; i < epb; i++) {
1080 zrl_init(&dnh[i].dnh_zrlock);
1081 dnh[i].dnh_dnode = NULL;
1082 }
1083 if (winner = dmu_buf_set_user(&db->db, children_dnodes, NULL,
1084 dnode_buf_pageout)) {
1085 kmem_free(children_dnodes, sizeof (dnode_children_t) +
1086 (epb - 1) * sizeof (dnode_handle_t));
1087 children_dnodes = winner;
1088 }
1089 }
1090 ASSERT(children_dnodes->dnc_count == epb);
1091
1092 dnh = &children_dnodes->dnc_children[idx];
1093 zrl_add(&dnh->dnh_zrlock);
1094 if ((dn = dnh->dnh_dnode) == NULL) {
1095 dnode_phys_t *phys = (dnode_phys_t *)db->db.db_data+idx;
1096 dnode_t *winner;
1097
1098 dn = dnode_create(os, phys, db, object, dnh);
1099 winner = atomic_cas_ptr(&dnh->dnh_dnode, NULL, dn);
1100 if (winner != NULL) {
1101 zrl_add(&dnh->dnh_zrlock);
1102 dnode_destroy(dn); /* implicit zrl_remove() */
1103 dn = winner;
1104 }
1105 }
1106
1107 mutex_enter(&dn->dn_mtx);
1108 type = dn->dn_type;
1109 if (dn->dn_free_txg ||
1110 ((flag & DNODE_MUST_BE_ALLOCATED) && type == DMU_OT_NONE) ||
1111 ((flag & DNODE_MUST_BE_FREE) &&
1112 (type != DMU_OT_NONE || !refcount_is_zero(&dn->dn_holds)))) {
1113 mutex_exit(&dn->dn_mtx);
1114 zrl_remove(&dnh->dnh_zrlock);
1115 dbuf_rele(db, FTAG);
1116 return (type == DMU_OT_NONE ? ENOENT : EEXIST);
1117 }
1118 mutex_exit(&dn->dn_mtx);
1119
1120 if (refcount_add(&dn->dn_holds, tag) == 1)
1121 dbuf_add_ref(db, dnh);
1122 /* Now we can rely on the hold to prevent the dnode from moving. */
1123 zrl_remove(&dnh->dnh_zrlock);
1124
1125 DNODE_VERIFY(dn);
1126 ASSERT3P(dn->dn_dbuf, ==, db);
1127 ASSERT3U(dn->dn_object, ==, object);
1128 dbuf_rele(db, FTAG);
1129
1130 *dnp = dn;
1131 return (0);
1132 }
1133
1134 /*
1135 * Return held dnode if the object is allocated, NULL if not.
1136 */
1137 int
1138 dnode_hold(objset_t *os, uint64_t object, void *tag, dnode_t **dnp)
1139 {
1140 return (dnode_hold_impl(os, object, DNODE_MUST_BE_ALLOCATED, tag, dnp));
1141 }
1142
1143 /*
1144 * Can only add a reference if there is already at least one
1145 * reference on the dnode. Returns FALSE if unable to add a
1146 * new reference.
1147 */
1148 boolean_t
1149 dnode_add_ref(dnode_t *dn, void *tag)
1150 {
1151 mutex_enter(&dn->dn_mtx);
1152 if (refcount_is_zero(&dn->dn_holds)) {
1153 mutex_exit(&dn->dn_mtx);
1154 return (FALSE);
1155 }
1156 VERIFY(1 < refcount_add(&dn->dn_holds, tag));
1157 mutex_exit(&dn->dn_mtx);
1158 return (TRUE);
1159 }
1160
1161 void
1162 dnode_rele(dnode_t *dn, void *tag)
1163 {
1164 uint64_t refs;
1165 /* Get while the hold prevents the dnode from moving. */
1166 dmu_buf_impl_t *db = dn->dn_dbuf;
1167 dnode_handle_t *dnh = dn->dn_handle;
1168
1169 mutex_enter(&dn->dn_mtx);
1170 refs = refcount_remove(&dn->dn_holds, tag);
1171 mutex_exit(&dn->dn_mtx);
1172
1173 /*
1174 * It's unsafe to release the last hold on a dnode by dnode_rele() or
1175 * indirectly by dbuf_rele() while relying on the dnode handle to
1176 * prevent the dnode from moving, since releasing the last hold could
1177 * result in the dnode's parent dbuf evicting its dnode handles. For
1178 * that reason anyone calling dnode_rele() or dbuf_rele() without some
1179 * other direct or indirect hold on the dnode must first drop the dnode
1180 * handle.
1181 */
1182 ASSERT(refs > 0 || dnh->dnh_zrlock.zr_owner != curthread);
1183
1184 /* NOTE: the DNODE_DNODE does not have a dn_dbuf */
1185 if (refs == 0 && db != NULL) {
1186 /*
1187 * Another thread could add a hold to the dnode handle in
1188 * dnode_hold_impl() while holding the parent dbuf. Since the
1189 * hold on the parent dbuf prevents the handle from being
1190 * destroyed, the hold on the handle is OK. We can't yet assert
1191 * that the handle has zero references, but that will be
1192 * asserted anyway when the handle gets destroyed.
1193 */
1194 dbuf_rele(db, dnh);
1195 }
1196 }
1197
1198 void
1199 dnode_setdirty(dnode_t *dn, dmu_tx_t *tx)
1200 {
1201 objset_t *os = dn->dn_objset;
1202 uint64_t txg = tx->tx_txg;
1203
1204 if (DMU_OBJECT_IS_SPECIAL(dn->dn_object)) {
1205 dsl_dataset_dirty(os->os_dsl_dataset, tx);
1206 return;
1207 }
1208
1209 DNODE_VERIFY(dn);
1210
1211 #ifdef ZFS_DEBUG
1212 mutex_enter(&dn->dn_mtx);
1213 ASSERT(dn->dn_phys->dn_type || dn->dn_allocated_txg);
1214 ASSERT(dn->dn_free_txg == 0 || dn->dn_free_txg >= txg);
1215 mutex_exit(&dn->dn_mtx);
1216 #endif
1217
1218 /*
1219 * Determine old uid/gid when necessary
1220 */
1221 dmu_objset_userquota_get_ids(dn, B_TRUE, tx);
1222
1223 mutex_enter(&os->os_lock);
1224
1225 /*
1226 * If we are already marked dirty, we're done.
1227 */
1228 if (list_link_active(&dn->dn_dirty_link[txg & TXG_MASK])) {
1229 mutex_exit(&os->os_lock);
1230 return;
1231 }
1232
1233 ASSERT(!refcount_is_zero(&dn->dn_holds) || list_head(&dn->dn_dbufs));
1234 ASSERT(dn->dn_datablksz != 0);
1235 ASSERT3U(dn->dn_next_bonuslen[txg&TXG_MASK], ==, 0);
1236 ASSERT3U(dn->dn_next_blksz[txg&TXG_MASK], ==, 0);
1237 ASSERT3U(dn->dn_next_bonustype[txg&TXG_MASK], ==, 0);
1238
1239 dprintf_ds(os->os_dsl_dataset, "obj=%llu txg=%llu\n",
1240 dn->dn_object, txg);
1241
1242 if (dn->dn_free_txg > 0 && dn->dn_free_txg <= txg) {
1243 list_insert_tail(&os->os_free_dnodes[txg&TXG_MASK], dn);
1244 } else {
1245 list_insert_tail(&os->os_dirty_dnodes[txg&TXG_MASK], dn);
1246 }
1247
1248 mutex_exit(&os->os_lock);
1249
1250 /*
1251 * The dnode maintains a hold on its containing dbuf as
1252 * long as there are holds on it. Each instantiated child
1253 * dbuf maintains a hold on the dnode. When the last child
1254 * drops its hold, the dnode will drop its hold on the
1255 * containing dbuf. We add a "dirty hold" here so that the
1256 * dnode will hang around after we finish processing its
1257 * children.
1258 */
1259 VERIFY(dnode_add_ref(dn, (void *)(uintptr_t)tx->tx_txg));
1260
1261 (void) dbuf_dirty(dn->dn_dbuf, tx);
1262
1263 dsl_dataset_dirty(os->os_dsl_dataset, tx);
1264 }
1265
1266 void
1267 dnode_free(dnode_t *dn, dmu_tx_t *tx)
1268 {
1269 int txgoff = tx->tx_txg & TXG_MASK;
1270
1271 dprintf("dn=%p txg=%llu\n", dn, tx->tx_txg);
1272
1273 /* we should be the only holder... hopefully */
1274 /* ASSERT3U(refcount_count(&dn->dn_holds), ==, 1); */
1275
1276 mutex_enter(&dn->dn_mtx);
1277 if (dn->dn_type == DMU_OT_NONE || dn->dn_free_txg) {
1278 mutex_exit(&dn->dn_mtx);
1279 return;
1280 }
1281 dn->dn_free_txg = tx->tx_txg;
1282 mutex_exit(&dn->dn_mtx);
1283
1284 /*
1285 * If the dnode is already dirty, it needs to be moved from
1286 * the dirty list to the free list.
1287 */
1288 mutex_enter(&dn->dn_objset->os_lock);
1289 if (list_link_active(&dn->dn_dirty_link[txgoff])) {
1290 list_remove(&dn->dn_objset->os_dirty_dnodes[txgoff], dn);
1291 list_insert_tail(&dn->dn_objset->os_free_dnodes[txgoff], dn);
1292 mutex_exit(&dn->dn_objset->os_lock);
1293 } else {
1294 mutex_exit(&dn->dn_objset->os_lock);
1295 dnode_setdirty(dn, tx);
1296 }
1297 }
1298
1299 /*
1300 * Try to change the block size for the indicated dnode. This can only
1301 * succeed if there are no blocks allocated or dirty beyond first block
1302 */
1303 int
1304 dnode_set_blksz(dnode_t *dn, uint64_t size, int ibs, dmu_tx_t *tx)
1305 {
1306 dmu_buf_impl_t *db, *db_next;
1307 int err;
1308
1309 if (size == 0)
1310 size = SPA_MINBLOCKSIZE;
1311 if (size > SPA_MAXBLOCKSIZE)
1312 size = SPA_MAXBLOCKSIZE;
1313 else
1314 size = P2ROUNDUP(size, SPA_MINBLOCKSIZE);
1315
1316 if (ibs == dn->dn_indblkshift)
1317 ibs = 0;
1318
1319 if (size >> SPA_MINBLOCKSHIFT == dn->dn_datablkszsec && ibs == 0)
1320 return (0);
1321
1322 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
1323
1324 /* Check for any allocated blocks beyond the first */
1325 if (dn->dn_phys->dn_maxblkid != 0)
1326 goto fail;
1327
1328 mutex_enter(&dn->dn_dbufs_mtx);
1329 for (db = list_head(&dn->dn_dbufs); db; db = db_next) {
1330 db_next = list_next(&dn->dn_dbufs, db);
1331
1332 if (db->db_blkid != 0 && db->db_blkid != DMU_BONUS_BLKID &&
1333 db->db_blkid != DMU_SPILL_BLKID) {
1334 mutex_exit(&dn->dn_dbufs_mtx);
1335 goto fail;
1336 }
1337 }
1338 mutex_exit(&dn->dn_dbufs_mtx);
1339
1340 if (ibs && dn->dn_nlevels != 1)
1341 goto fail;
1342
1343 /* resize the old block */
1344 err = dbuf_hold_impl(dn, 0, 0, TRUE, FTAG, &db);
1345 if (err == 0)
1346 dbuf_new_size(db, size, tx);
1347 else if (err != ENOENT)
1348 goto fail;
1349
1350 dnode_setdblksz(dn, size);
1351 dnode_setdirty(dn, tx);
1352 dn->dn_next_blksz[tx->tx_txg&TXG_MASK] = size;
1353 if (ibs) {
1354 dn->dn_indblkshift = ibs;
1355 dn->dn_next_indblkshift[tx->tx_txg&TXG_MASK] = ibs;
1356 }
1357 /* rele after we have fixed the blocksize in the dnode */
1358 if (db)
1359 dbuf_rele(db, FTAG);
1360
1361 rw_exit(&dn->dn_struct_rwlock);
1362 return (0);
1363
1364 fail:
1365 rw_exit(&dn->dn_struct_rwlock);
1366 return (ENOTSUP);
1367 }
1368
1369 /* read-holding callers must not rely on the lock being continuously held */
1370 void
1371 dnode_new_blkid(dnode_t *dn, uint64_t blkid, dmu_tx_t *tx, boolean_t have_read)
1372 {
1373 uint64_t txgoff = tx->tx_txg & TXG_MASK;
1374 int epbs, new_nlevels;
1375 uint64_t sz;
1376
1377 ASSERT(blkid != DMU_BONUS_BLKID);
1378
1379 ASSERT(have_read ?
1380 RW_READ_HELD(&dn->dn_struct_rwlock) :
1381 RW_WRITE_HELD(&dn->dn_struct_rwlock));
1382
1383 /*
1384 * if we have a read-lock, check to see if we need to do any work
1385 * before upgrading to a write-lock.
1386 */
1387 if (have_read) {
1388 if (blkid <= dn->dn_maxblkid)
1389 return;
1390
1391 if (!rw_tryupgrade(&dn->dn_struct_rwlock)) {
1392 rw_exit(&dn->dn_struct_rwlock);
1393 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
1394 }
1395 }
1396
1397 if (blkid <= dn->dn_maxblkid)
1398 goto out;
1399
1400 dn->dn_maxblkid = blkid;
1401
1402 /*
1403 * Compute the number of levels necessary to support the new maxblkid.
1404 */
1405 new_nlevels = 1;
1406 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT;
1407 for (sz = dn->dn_nblkptr;
1408 sz <= blkid && sz >= dn->dn_nblkptr; sz <<= epbs)
1409 new_nlevels++;
1410
1411 if (new_nlevels > dn->dn_nlevels) {
1412 int old_nlevels = dn->dn_nlevels;
1413 dmu_buf_impl_t *db;
1414 list_t *list;
1415 dbuf_dirty_record_t *new, *dr, *dr_next;
1416
1417 dn->dn_nlevels = new_nlevels;
1418
1419 ASSERT3U(new_nlevels, >, dn->dn_next_nlevels[txgoff]);
1420 dn->dn_next_nlevels[txgoff] = new_nlevels;
1421
1422 /* dirty the left indirects */
1423 db = dbuf_hold_level(dn, old_nlevels, 0, FTAG);
1424 ASSERT(db != NULL);
1425 new = dbuf_dirty(db, tx);
1426 dbuf_rele(db, FTAG);
1427
1428 /* transfer the dirty records to the new indirect */
1429 mutex_enter(&dn->dn_mtx);
1430 mutex_enter(&new->dt.di.dr_mtx);
1431 list = &dn->dn_dirty_records[txgoff];
1432 for (dr = list_head(list); dr; dr = dr_next) {
1433 dr_next = list_next(&dn->dn_dirty_records[txgoff], dr);
1434 if (dr->dr_dbuf->db_level != new_nlevels-1 &&
1435 dr->dr_dbuf->db_blkid != DMU_BONUS_BLKID &&
1436 dr->dr_dbuf->db_blkid != DMU_SPILL_BLKID) {
1437 ASSERT(dr->dr_dbuf->db_level == old_nlevels-1);
1438 list_remove(&dn->dn_dirty_records[txgoff], dr);
1439 list_insert_tail(&new->dt.di.dr_children, dr);
1440 dr->dr_parent = new;
1441 }
1442 }
1443 mutex_exit(&new->dt.di.dr_mtx);
1444 mutex_exit(&dn->dn_mtx);
1445 }
1446
1447 out:
1448 if (have_read)
1449 rw_downgrade(&dn->dn_struct_rwlock);
1450 }
1451
1452 void
1453 dnode_clear_range(dnode_t *dn, uint64_t blkid, uint64_t nblks, dmu_tx_t *tx)
1454 {
1455 avl_tree_t *tree = &dn->dn_ranges[tx->tx_txg&TXG_MASK];
1456 avl_index_t where;
1457 free_range_t *rp;
1458 free_range_t rp_tofind;
1459 uint64_t endblk = blkid + nblks;
1460
1461 ASSERT(MUTEX_HELD(&dn->dn_mtx));
1462 ASSERT(nblks <= UINT64_MAX - blkid); /* no overflow */
1463
1464 dprintf_dnode(dn, "blkid=%llu nblks=%llu txg=%llu\n",
1465 blkid, nblks, tx->tx_txg);
1466 rp_tofind.fr_blkid = blkid;
1467 rp = avl_find(tree, &rp_tofind, &where);
1468 if (rp == NULL)
1469 rp = avl_nearest(tree, where, AVL_BEFORE);
1470 if (rp == NULL)
1471 rp = avl_nearest(tree, where, AVL_AFTER);
1472
1473 while (rp && (rp->fr_blkid <= blkid + nblks)) {
1474 uint64_t fr_endblk = rp->fr_blkid + rp->fr_nblks;
1475 free_range_t *nrp = AVL_NEXT(tree, rp);
1476
1477 if (blkid <= rp->fr_blkid && endblk >= fr_endblk) {
1478 /* clear this entire range */
1479 avl_remove(tree, rp);
1480 kmem_free(rp, sizeof (free_range_t));
1481 } else if (blkid <= rp->fr_blkid &&
1482 endblk > rp->fr_blkid && endblk < fr_endblk) {
1483 /* clear the beginning of this range */
1484 rp->fr_blkid = endblk;
1485 rp->fr_nblks = fr_endblk - endblk;
1486 } else if (blkid > rp->fr_blkid && blkid < fr_endblk &&
1487 endblk >= fr_endblk) {
1488 /* clear the end of this range */
1489 rp->fr_nblks = blkid - rp->fr_blkid;
1490 } else if (blkid > rp->fr_blkid && endblk < fr_endblk) {
1491 /* clear a chunk out of this range */
1492 free_range_t *new_rp =
1493 kmem_alloc(sizeof (free_range_t), KM_SLEEP);
1494
1495 new_rp->fr_blkid = endblk;
1496 new_rp->fr_nblks = fr_endblk - endblk;
1497 avl_insert_here(tree, new_rp, rp, AVL_AFTER);
1498 rp->fr_nblks = blkid - rp->fr_blkid;
1499 }
1500 /* there may be no overlap */
1501 rp = nrp;
1502 }
1503 }
1504
1505 void
1506 dnode_free_range(dnode_t *dn, uint64_t off, uint64_t len, dmu_tx_t *tx)
1507 {
1508 dmu_buf_impl_t *db;
1509 uint64_t blkoff, blkid, nblks;
1510 int blksz, blkshift, head, tail;
1511 int trunc = FALSE;
1512 int epbs;
1513
1514 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
1515 blksz = dn->dn_datablksz;
1516 blkshift = dn->dn_datablkshift;
1517 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT;
1518
1519 if (len == -1ULL) {
1520 len = UINT64_MAX - off;
1521 trunc = TRUE;
1522 }
1523
1524 /*
1525 * First, block align the region to free:
1526 */
1527 if (ISP2(blksz)) {
1528 head = P2NPHASE(off, blksz);
1529 blkoff = P2PHASE(off, blksz);
1530 if ((off >> blkshift) > dn->dn_maxblkid)
1531 goto out;
1532 } else {
1533 ASSERT(dn->dn_maxblkid == 0);
1534 if (off == 0 && len >= blksz) {
1535 /* Freeing the whole block; fast-track this request */
1536 blkid = 0;
1537 nblks = 1;
1538 goto done;
1539 } else if (off >= blksz) {
1540 /* Freeing past end-of-data */
1541 goto out;
1542 } else {
1543 /* Freeing part of the block. */
1544 head = blksz - off;
1545 ASSERT3U(head, >, 0);
1546 }
1547 blkoff = off;
1548 }
1549 /* zero out any partial block data at the start of the range */
1550 if (head) {
1551 ASSERT3U(blkoff + head, ==, blksz);
1552 if (len < head)
1553 head = len;
1554 if (dbuf_hold_impl(dn, 0, dbuf_whichblock(dn, off), TRUE,
1555 FTAG, &db) == 0) {
1556 caddr_t data;
1557
1558 /* don't dirty if it isn't on disk and isn't dirty */
1559 if (db->db_last_dirty ||
1560 (db->db_blkptr && !BP_IS_HOLE(db->db_blkptr))) {
1561 rw_exit(&dn->dn_struct_rwlock);
1562 dbuf_will_dirty(db, tx);
1563 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
1564 data = db->db.db_data;
1565 bzero(data + blkoff, head);
1566 }
1567 dbuf_rele(db, FTAG);
1568 }
1569 off += head;
1570 len -= head;
1571 }
1572
1573 /* If the range was less than one block, we're done */
1574 if (len == 0)
1575 goto out;
1576
1577 /* If the remaining range is past end of file, we're done */
1578 if ((off >> blkshift) > dn->dn_maxblkid)
1579 goto out;
1580
1581 ASSERT(ISP2(blksz));
1582 if (trunc)
1583 tail = 0;
1584 else
1585 tail = P2PHASE(len, blksz);
1586
1587 ASSERT3U(P2PHASE(off, blksz), ==, 0);
1588 /* zero out any partial block data at the end of the range */
1589 if (tail) {
1590 if (len < tail)
1591 tail = len;
1592 if (dbuf_hold_impl(dn, 0, dbuf_whichblock(dn, off+len),
1593 TRUE, FTAG, &db) == 0) {
1594 /* don't dirty if not on disk and not dirty */
1595 if (db->db_last_dirty ||
1596 (db->db_blkptr && !BP_IS_HOLE(db->db_blkptr))) {
1597 rw_exit(&dn->dn_struct_rwlock);
1598 dbuf_will_dirty(db, tx);
1599 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
1600 bzero(db->db.db_data, tail);
1601 }
1602 dbuf_rele(db, FTAG);
1603 }
1604 len -= tail;
1605 }
1606
1607 /* If the range did not include a full block, we are done */
1608 if (len == 0)
1609 goto out;
1610
1611 ASSERT(IS_P2ALIGNED(off, blksz));
1612 ASSERT(trunc || IS_P2ALIGNED(len, blksz));
1613 blkid = off >> blkshift;
1614 nblks = len >> blkshift;
1615 if (trunc)
1616 nblks += 1;
1617
1618 /*
1619 * Read in and mark all the level-1 indirects dirty,
1620 * so that they will stay in memory until syncing phase.
1621 * Always dirty the first and last indirect to make sure
1622 * we dirty all the partial indirects.
1623 */
1624 if (dn->dn_nlevels > 1) {
1625 uint64_t i, first, last;
1626 int shift = epbs + dn->dn_datablkshift;
1627
1628 first = blkid >> epbs;
1629 if (db = dbuf_hold_level(dn, 1, first, FTAG)) {
1630 dbuf_will_dirty(db, tx);
1631 dbuf_rele(db, FTAG);
1632 }
1633 if (trunc)
1634 last = dn->dn_maxblkid >> epbs;
1635 else
1636 last = (blkid + nblks - 1) >> epbs;
1637 if (last > first && (db = dbuf_hold_level(dn, 1, last, FTAG))) {
1638 dbuf_will_dirty(db, tx);
1639 dbuf_rele(db, FTAG);
1640 }
1641 for (i = first + 1; i < last; i++) {
1642 uint64_t ibyte = i << shift;
1643 int err;
1644
1645 err = dnode_next_offset(dn,
1646 DNODE_FIND_HAVELOCK, &ibyte, 1, 1, 0);
1647 i = ibyte >> shift;
1648 if (err == ESRCH || i >= last)
1649 break;
1650 ASSERT(err == 0);
1651 db = dbuf_hold_level(dn, 1, i, FTAG);
1652 if (db) {
1653 dbuf_will_dirty(db, tx);
1654 dbuf_rele(db, FTAG);
1655 }
1656 }
1657 }
1658 done:
1659 /*
1660 * Add this range to the dnode range list.
1661 * We will finish up this free operation in the syncing phase.
1662 */
1663 mutex_enter(&dn->dn_mtx);
1664 dnode_clear_range(dn, blkid, nblks, tx);
1665 {
1666 free_range_t *rp, *found;
1667 avl_index_t where;
1668 avl_tree_t *tree = &dn->dn_ranges[tx->tx_txg&TXG_MASK];
1669
1670 /* Add new range to dn_ranges */
1671 rp = kmem_alloc(sizeof (free_range_t), KM_SLEEP);
1672 rp->fr_blkid = blkid;
1673 rp->fr_nblks = nblks;
1674 found = avl_find(tree, rp, &where);
1675 ASSERT(found == NULL);
1676 avl_insert(tree, rp, where);
1677 dprintf_dnode(dn, "blkid=%llu nblks=%llu txg=%llu\n",
1678 blkid, nblks, tx->tx_txg);
1679 }
1680 mutex_exit(&dn->dn_mtx);
1681
1682 dbuf_free_range(dn, blkid, blkid + nblks - 1, tx);
1683 dnode_setdirty(dn, tx);
1684 out:
1685 if (trunc && dn->dn_maxblkid >= (off >> blkshift))
1686 dn->dn_maxblkid = (off >> blkshift ? (off >> blkshift) - 1 : 0);
1687
1688 rw_exit(&dn->dn_struct_rwlock);
1689 }
1690
1691 static boolean_t
1692 dnode_spill_freed(dnode_t *dn)
1693 {
1694 int i;
1695
1696 mutex_enter(&dn->dn_mtx);
1697 for (i = 0; i < TXG_SIZE; i++) {
1698 if (dn->dn_rm_spillblk[i] == DN_KILL_SPILLBLK)
1699 break;
1700 }
1701 mutex_exit(&dn->dn_mtx);
1702 return (i < TXG_SIZE);
1703 }
1704
1705 /* return TRUE if this blkid was freed in a recent txg, or FALSE if it wasn't */
1706 uint64_t
1707 dnode_block_freed(dnode_t *dn, uint64_t blkid)
1708 {
1709 free_range_t range_tofind;
1710 void *dp = spa_get_dsl(dn->dn_objset->os_spa);
1711 int i;
1712
1713 if (blkid == DMU_BONUS_BLKID)
1714 return (FALSE);
1715
1716 /*
1717 * If we're in the process of opening the pool, dp will not be
1718 * set yet, but there shouldn't be anything dirty.
1719 */
1720 if (dp == NULL)
1721 return (FALSE);
1722
1723 if (dn->dn_free_txg)
1724 return (TRUE);
1725
1726 if (blkid == DMU_SPILL_BLKID)
1727 return (dnode_spill_freed(dn));
1728
1729 range_tofind.fr_blkid = blkid;
1730 mutex_enter(&dn->dn_mtx);
1731 for (i = 0; i < TXG_SIZE; i++) {
1732 free_range_t *range_found;
1733 avl_index_t idx;
1734
1735 range_found = avl_find(&dn->dn_ranges[i], &range_tofind, &idx);
1736 if (range_found) {
1737 ASSERT(range_found->fr_nblks > 0);
1738 break;
1739 }
1740 range_found = avl_nearest(&dn->dn_ranges[i], idx, AVL_BEFORE);
1741 if (range_found &&
1742 range_found->fr_blkid + range_found->fr_nblks > blkid)
1743 break;
1744 }
1745 mutex_exit(&dn->dn_mtx);
1746 return (i < TXG_SIZE);
1747 }
1748
1749 /* call from syncing context when we actually write/free space for this dnode */
1750 void
1751 dnode_diduse_space(dnode_t *dn, int64_t delta)
1752 {
1753 uint64_t space;
1754 dprintf_dnode(dn, "dn=%p dnp=%p used=%llu delta=%lld\n",
1755 dn, dn->dn_phys,
1756 (u_longlong_t)dn->dn_phys->dn_used,
1757 (longlong_t)delta);
1758
1759 mutex_enter(&dn->dn_mtx);
1760 space = DN_USED_BYTES(dn->dn_phys);
1761 if (delta > 0) {
1762 ASSERT3U(space + delta, >=, space); /* no overflow */
1763 } else {
1764 ASSERT3U(space, >=, -delta); /* no underflow */
1765 }
1766 space += delta;
1767 if (spa_version(dn->dn_objset->os_spa) < SPA_VERSION_DNODE_BYTES) {
1768 ASSERT((dn->dn_phys->dn_flags & DNODE_FLAG_USED_BYTES) == 0);
1769 ASSERT3U(P2PHASE(space, 1<<DEV_BSHIFT), ==, 0);
1770 dn->dn_phys->dn_used = space >> DEV_BSHIFT;
1771 } else {
1772 dn->dn_phys->dn_used = space;
1773 dn->dn_phys->dn_flags |= DNODE_FLAG_USED_BYTES;
1774 }
1775 mutex_exit(&dn->dn_mtx);
1776 }
1777
1778 /*
1779 * Call when we think we're going to write/free space in open context.
1780 * Be conservative (ie. OK to write less than this or free more than
1781 * this, but don't write more or free less).
1782 */
1783 void
1784 dnode_willuse_space(dnode_t *dn, int64_t space, dmu_tx_t *tx)
1785 {
1786 objset_t *os = dn->dn_objset;
1787 dsl_dataset_t *ds = os->os_dsl_dataset;
1788
1789 if (space > 0)
1790 space = spa_get_asize(os->os_spa, space);
1791
1792 if (ds)
1793 dsl_dir_willuse_space(ds->ds_dir, space, tx);
1794
1795 dmu_tx_willuse_space(tx, space);
1796 }
1797
1798 /*
1799 * This function scans a block at the indicated "level" looking for
1800 * a hole or data (depending on 'flags'). If level > 0, then we are
1801 * scanning an indirect block looking at its pointers. If level == 0,
1802 * then we are looking at a block of dnodes. If we don't find what we
1803 * are looking for in the block, we return ESRCH. Otherwise, return
1804 * with *offset pointing to the beginning (if searching forwards) or
1805 * end (if searching backwards) of the range covered by the block
1806 * pointer we matched on (or dnode).
1807 *
1808 * The basic search algorithm used below by dnode_next_offset() is to
1809 * use this function to search up the block tree (widen the search) until
1810 * we find something (i.e., we don't return ESRCH) and then search back
1811 * down the tree (narrow the search) until we reach our original search
1812 * level.
1813 */
1814 static int
1815 dnode_next_offset_level(dnode_t *dn, int flags, uint64_t *offset,
1816 int lvl, uint64_t blkfill, uint64_t txg)
1817 {
1818 dmu_buf_impl_t *db = NULL;
1819 void *data = NULL;
1820 uint64_t epbs = dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT;
1821 uint64_t epb = 1ULL << epbs;
1822 uint64_t minfill, maxfill;
1823 boolean_t hole;
1824 int i, inc, error, span;
1825
1826 dprintf("probing object %llu offset %llx level %d of %u\n",
1827 dn->dn_object, *offset, lvl, dn->dn_phys->dn_nlevels);
1828
1829 hole = ((flags & DNODE_FIND_HOLE) != 0);
1830 inc = (flags & DNODE_FIND_BACKWARDS) ? -1 : 1;
1831 ASSERT(txg == 0 || !hole);
1832
1833 if (lvl == dn->dn_phys->dn_nlevels) {
1834 error = 0;
1835 epb = dn->dn_phys->dn_nblkptr;
1836 data = dn->dn_phys->dn_blkptr;
1837 } else {
1838 uint64_t blkid = dbuf_whichblock(dn, *offset) >> (epbs * lvl);
1839 error = dbuf_hold_impl(dn, lvl, blkid, TRUE, FTAG, &db);
1840 if (error) {
1841 if (error != ENOENT)
1842 return (error);
1843 if (hole)
1844 return (0);
1845 /*
1846 * This can only happen when we are searching up
1847 * the block tree for data. We don't really need to
1848 * adjust the offset, as we will just end up looking
1849 * at the pointer to this block in its parent, and its
1850 * going to be unallocated, so we will skip over it.
1851 */
1852 return (ESRCH);
1853 }
1854 error = dbuf_read(db, NULL, DB_RF_CANFAIL | DB_RF_HAVESTRUCT);
1855 if (error) {
1856 dbuf_rele(db, FTAG);
1857 return (error);
1858 }
1859 data = db->db.db_data;
1860 }
1861
1862 if (db && txg &&
1863 (db->db_blkptr == NULL || db->db_blkptr->blk_birth <= txg)) {
1864 /*
1865 * This can only happen when we are searching up the tree
1866 * and these conditions mean that we need to keep climbing.
1867 */
1868 error = ESRCH;
1869 } else if (lvl == 0) {
1870 dnode_phys_t *dnp = data;
1871 span = DNODE_SHIFT;
1872 ASSERT(dn->dn_type == DMU_OT_DNODE);
1873
1874 for (i = (*offset >> span) & (blkfill - 1);
1875 i >= 0 && i < blkfill; i += inc) {
1876 if ((dnp[i].dn_type == DMU_OT_NONE) == hole)
1877 break;
1878 *offset += (1ULL << span) * inc;
1879 }
1880 if (i < 0 || i == blkfill)
1881 error = ESRCH;
1882 } else {
1883 blkptr_t *bp = data;
1884 uint64_t start = *offset;
1885 span = (lvl - 1) * epbs + dn->dn_datablkshift;
1886 minfill = 0;
1887 maxfill = blkfill << ((lvl - 1) * epbs);
1888
1889 if (hole)
1890 maxfill--;
1891 else
1892 minfill++;
1893
1894 *offset = *offset >> span;
1895 for (i = BF64_GET(*offset, 0, epbs);
1896 i >= 0 && i < epb; i += inc) {
1897 if (bp[i].blk_fill >= minfill &&
1898 bp[i].blk_fill <= maxfill &&
1899 (hole || bp[i].blk_birth > txg))
1900 break;
1901 if (inc > 0 || *offset > 0)
1902 *offset += inc;
1903 }
1904 *offset = *offset << span;
1905 if (inc < 0) {
1906 /* traversing backwards; position offset at the end */
1907 ASSERT3U(*offset, <=, start);
1908 *offset = MIN(*offset + (1ULL << span) - 1, start);
1909 } else if (*offset < start) {
1910 *offset = start;
1911 }
1912 if (i < 0 || i >= epb)
1913 error = ESRCH;
1914 }
1915
1916 if (db)
1917 dbuf_rele(db, FTAG);
1918
1919 return (error);
1920 }
1921
1922 /*
1923 * Find the next hole, data, or sparse region at or after *offset.
1924 * The value 'blkfill' tells us how many items we expect to find
1925 * in an L0 data block; this value is 1 for normal objects,
1926 * DNODES_PER_BLOCK for the meta dnode, and some fraction of
1927 * DNODES_PER_BLOCK when searching for sparse regions thereof.
1928 *
1929 * Examples:
1930 *
1931 * dnode_next_offset(dn, flags, offset, 1, 1, 0);
1932 * Finds the next/previous hole/data in a file.
1933 * Used in dmu_offset_next().
1934 *
1935 * dnode_next_offset(mdn, flags, offset, 0, DNODES_PER_BLOCK, txg);
1936 * Finds the next free/allocated dnode an objset's meta-dnode.
1937 * Only finds objects that have new contents since txg (ie.
1938 * bonus buffer changes and content removal are ignored).
1939 * Used in dmu_object_next().
1940 *
1941 * dnode_next_offset(mdn, DNODE_FIND_HOLE, offset, 2, DNODES_PER_BLOCK >> 2, 0);
1942 * Finds the next L2 meta-dnode bp that's at most 1/4 full.
1943 * Used in dmu_object_alloc().
1944 */
1945 int
1946 dnode_next_offset(dnode_t *dn, int flags, uint64_t *offset,
1947 int minlvl, uint64_t blkfill, uint64_t txg)
1948 {
1949 uint64_t initial_offset = *offset;
1950 int lvl, maxlvl;
1951 int error = 0;
1952
1953 if (!(flags & DNODE_FIND_HAVELOCK))
1954 rw_enter(&dn->dn_struct_rwlock, RW_READER);
1955
1956 if (dn->dn_phys->dn_nlevels == 0) {
1957 error = ESRCH;
1958 goto out;
1959 }
1960
1961 if (dn->dn_datablkshift == 0) {
1962 if (*offset < dn->dn_datablksz) {
1963 if (flags & DNODE_FIND_HOLE)
1964 *offset = dn->dn_datablksz;
1965 } else {
1966 error = ESRCH;
1967 }
1968 goto out;
1969 }
1970
1971 maxlvl = dn->dn_phys->dn_nlevels;
1972
1973 for (lvl = minlvl; lvl <= maxlvl; lvl++) {
1974 error = dnode_next_offset_level(dn,
1975 flags, offset, lvl, blkfill, txg);
1976 if (error != ESRCH)
1977 break;
1978 }
1979
1980 while (error == 0 && --lvl >= minlvl) {
1981 error = dnode_next_offset_level(dn,
1982 flags, offset, lvl, blkfill, txg);
1983 }
1984
1985 if (error == 0 && (flags & DNODE_FIND_BACKWARDS ?
1986 initial_offset < *offset : initial_offset > *offset))
1987 error = ESRCH;
1988 out:
1989 if (!(flags & DNODE_FIND_HAVELOCK))
1990 rw_exit(&dn->dn_struct_rwlock);
1991
1992 return (error);
1993 }
Unleashed OS