1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21 /*
22 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
23 * Copyright (c) 2012, 2015 by Delphix. All rights reserved.
24 * Copyright (c) 2014 Spectra Logic Corporation, All rights reserved.
25 */
26
27 #include <sys/zfs_context.h>
28 #include <sys/dbuf.h>
29 #include <sys/dnode.h>
30 #include <sys/dmu.h>
31 #include <sys/dmu_impl.h>
32 #include <sys/dmu_tx.h>
33 #include <sys/dmu_objset.h>
34 #include <sys/dsl_dir.h>
35 #include <sys/dsl_dataset.h>
36 #include <sys/spa.h>
37 #include <sys/zio.h>
38 #include <sys/dmu_zfetch.h>
39 #include <sys/range_tree.h>
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 static int
dbuf_compare(const void * x1,const void * x2)64 dbuf_compare(const void *x1, const void *x2)
65 {
66 const dmu_buf_impl_t *d1 = x1;
67 const dmu_buf_impl_t *d2 = x2;
68
69 if (d1->db_level < d2->db_level) {
70 return (-1);
71 }
72 if (d1->db_level > d2->db_level) {
73 return (1);
74 }
75
76 if (d1->db_blkid < d2->db_blkid) {
77 return (-1);
78 }
79 if (d1->db_blkid > d2->db_blkid) {
80 return (1);
81 }
82
83 if (d1->db_state == DB_SEARCH) {
84 ASSERT3S(d2->db_state, !=, DB_SEARCH);
85 return (-1);
86 } else if (d2->db_state == DB_SEARCH) {
87 ASSERT3S(d1->db_state, !=, DB_SEARCH);
88 return (1);
89 }
90
91 if ((uintptr_t)d1 < (uintptr_t)d2) {
92 return (-1);
93 }
94 if ((uintptr_t)d1 > (uintptr_t)d2) {
95 return (1);
96 }
97 return (0);
98 }
99
100 /* ARGSUSED */
101 static int
dnode_cons(void * arg,void * unused,int kmflag)102 dnode_cons(void *arg, void *unused, int kmflag)
103 {
104 dnode_t *dn = arg;
105 int i;
106
107 rw_init(&dn->dn_struct_rwlock, NULL, RW_DEFAULT, NULL);
108 mutex_init(&dn->dn_mtx, NULL, MUTEX_DEFAULT, NULL);
109 mutex_init(&dn->dn_dbufs_mtx, NULL, MUTEX_DEFAULT, NULL);
110 cv_init(&dn->dn_notxholds, NULL, CV_DEFAULT, NULL);
111
112 /*
113 * Every dbuf has a reference, and dropping a tracked reference is
114 * O(number of references), so don't track dn_holds.
115 */
116 refcount_create_untracked(&dn->dn_holds);
117 refcount_create(&dn->dn_tx_holds);
118 list_link_init(&dn->dn_link);
119
120 bzero(&dn->dn_next_nblkptr[0], sizeof (dn->dn_next_nblkptr));
121 bzero(&dn->dn_next_nlevels[0], sizeof (dn->dn_next_nlevels));
122 bzero(&dn->dn_next_indblkshift[0], sizeof (dn->dn_next_indblkshift));
123 bzero(&dn->dn_next_bonustype[0], sizeof (dn->dn_next_bonustype));
124 bzero(&dn->dn_rm_spillblk[0], sizeof (dn->dn_rm_spillblk));
125 bzero(&dn->dn_next_bonuslen[0], sizeof (dn->dn_next_bonuslen));
126 bzero(&dn->dn_next_blksz[0], sizeof (dn->dn_next_blksz));
127
128 for (i = 0; i < TXG_SIZE; i++) {
129 list_link_init(&dn->dn_dirty_link[i]);
130 dn->dn_free_ranges[i] = NULL;
131 list_create(&dn->dn_dirty_records[i],
132 sizeof (dbuf_dirty_record_t),
133 offsetof(dbuf_dirty_record_t, dr_dirty_node));
134 }
135
136 dn->dn_allocated_txg = 0;
137 dn->dn_free_txg = 0;
138 dn->dn_assigned_txg = 0;
139 dn->dn_dirtyctx = 0;
140 dn->dn_dirtyctx_firstset = NULL;
141 dn->dn_bonus = NULL;
142 dn->dn_have_spill = B_FALSE;
143 dn->dn_zio = NULL;
144 dn->dn_oldused = 0;
145 dn->dn_oldflags = 0;
146 dn->dn_olduid = 0;
147 dn->dn_oldgid = 0;
148 dn->dn_newuid = 0;
149 dn->dn_newgid = 0;
150 dn->dn_id_flags = 0;
151
152 dn->dn_dbufs_count = 0;
153 dn->dn_unlisted_l0_blkid = 0;
154 avl_create(&dn->dn_dbufs, dbuf_compare, sizeof (dmu_buf_impl_t),
155 offsetof(dmu_buf_impl_t, db_link));
156
157 dn->dn_moved = 0;
158 return (0);
159 }
160
161 /* ARGSUSED */
162 static void
dnode_dest(void * arg,void * unused)163 dnode_dest(void *arg, void *unused)
164 {
165 int i;
166 dnode_t *dn = arg;
167
168 rw_destroy(&dn->dn_struct_rwlock);
169 mutex_destroy(&dn->dn_mtx);
170 mutex_destroy(&dn->dn_dbufs_mtx);
171 cv_destroy(&dn->dn_notxholds);
172 refcount_destroy(&dn->dn_holds);
173 refcount_destroy(&dn->dn_tx_holds);
174 ASSERT(!list_link_active(&dn->dn_link));
175
176 for (i = 0; i < TXG_SIZE; i++) {
177 ASSERT(!list_link_active(&dn->dn_dirty_link[i]));
178 ASSERT3P(dn->dn_free_ranges[i], ==, NULL);
179 list_destroy(&dn->dn_dirty_records[i]);
180 ASSERT0(dn->dn_next_nblkptr[i]);
181 ASSERT0(dn->dn_next_nlevels[i]);
182 ASSERT0(dn->dn_next_indblkshift[i]);
183 ASSERT0(dn->dn_next_bonustype[i]);
184 ASSERT0(dn->dn_rm_spillblk[i]);
185 ASSERT0(dn->dn_next_bonuslen[i]);
186 ASSERT0(dn->dn_next_blksz[i]);
187 }
188
189 ASSERT0(dn->dn_allocated_txg);
190 ASSERT0(dn->dn_free_txg);
191 ASSERT0(dn->dn_assigned_txg);
192 ASSERT0(dn->dn_dirtyctx);
193 ASSERT3P(dn->dn_dirtyctx_firstset, ==, NULL);
194 ASSERT3P(dn->dn_bonus, ==, NULL);
195 ASSERT(!dn->dn_have_spill);
196 ASSERT3P(dn->dn_zio, ==, NULL);
197 ASSERT0(dn->dn_oldused);
198 ASSERT0(dn->dn_oldflags);
199 ASSERT0(dn->dn_olduid);
200 ASSERT0(dn->dn_oldgid);
201 ASSERT0(dn->dn_newuid);
202 ASSERT0(dn->dn_newgid);
203 ASSERT0(dn->dn_id_flags);
204
205 ASSERT0(dn->dn_dbufs_count);
206 ASSERT0(dn->dn_unlisted_l0_blkid);
207 avl_destroy(&dn->dn_dbufs);
208 }
209
210 void
dnode_init(void)211 dnode_init(void)
212 {
213 ASSERT(dnode_cache == NULL);
214 dnode_cache = kmem_cache_create("dnode_t",
215 sizeof (dnode_t),
216 0, dnode_cons, dnode_dest, NULL, NULL, NULL, 0);
217 kmem_cache_set_move(dnode_cache, dnode_move);
218 }
219
220 void
dnode_fini(void)221 dnode_fini(void)
222 {
223 kmem_cache_destroy(dnode_cache);
224 dnode_cache = NULL;
225 }
226
227
228 #ifdef ZFS_DEBUG
229 void
dnode_verify(dnode_t * dn)230 dnode_verify(dnode_t *dn)
231 {
232 int drop_struct_lock = FALSE;
233
234 ASSERT(dn->dn_phys);
235 ASSERT(dn->dn_objset);
236 ASSERT(dn->dn_handle->dnh_dnode == dn);
237
238 ASSERT(DMU_OT_IS_VALID(dn->dn_phys->dn_type));
239
240 if (!(zfs_flags & ZFS_DEBUG_DNODE_VERIFY))
241 return;
242
243 if (!RW_WRITE_HELD(&dn->dn_struct_rwlock)) {
244 rw_enter(&dn->dn_struct_rwlock, RW_READER);
245 drop_struct_lock = TRUE;
246 }
247 if (dn->dn_phys->dn_type != DMU_OT_NONE || dn->dn_allocated_txg != 0) {
248 int i;
249 ASSERT3U(dn->dn_indblkshift, >=, 0);
250 ASSERT3U(dn->dn_indblkshift, <=, SPA_MAXBLOCKSHIFT);
251 if (dn->dn_datablkshift) {
252 ASSERT3U(dn->dn_datablkshift, >=, SPA_MINBLOCKSHIFT);
253 ASSERT3U(dn->dn_datablkshift, <=, SPA_MAXBLOCKSHIFT);
254 ASSERT3U(1<<dn->dn_datablkshift, ==, dn->dn_datablksz);
255 }
256 ASSERT3U(dn->dn_nlevels, <=, 30);
257 ASSERT(DMU_OT_IS_VALID(dn->dn_type));
258 ASSERT3U(dn->dn_nblkptr, >=, 1);
259 ASSERT3U(dn->dn_nblkptr, <=, DN_MAX_NBLKPTR);
260 ASSERT3U(dn->dn_bonuslen, <=, DN_MAX_BONUSLEN);
261 ASSERT3U(dn->dn_datablksz, ==,
262 dn->dn_datablkszsec << SPA_MINBLOCKSHIFT);
263 ASSERT3U(ISP2(dn->dn_datablksz), ==, dn->dn_datablkshift != 0);
264 ASSERT3U((dn->dn_nblkptr - 1) * sizeof (blkptr_t) +
265 dn->dn_bonuslen, <=, DN_MAX_BONUSLEN);
266 for (i = 0; i < TXG_SIZE; i++) {
267 ASSERT3U(dn->dn_next_nlevels[i], <=, dn->dn_nlevels);
268 }
269 }
270 if (dn->dn_phys->dn_type != DMU_OT_NONE)
271 ASSERT3U(dn->dn_phys->dn_nlevels, <=, dn->dn_nlevels);
272 ASSERT(DMU_OBJECT_IS_SPECIAL(dn->dn_object) || dn->dn_dbuf != NULL);
273 if (dn->dn_dbuf != NULL) {
274 ASSERT3P(dn->dn_phys, ==,
275 (dnode_phys_t *)dn->dn_dbuf->db.db_data +
276 (dn->dn_object % (dn->dn_dbuf->db.db_size >> DNODE_SHIFT)));
277 }
278 if (drop_struct_lock)
279 rw_exit(&dn->dn_struct_rwlock);
280 }
281 #endif
282
283 void
dnode_byteswap(dnode_phys_t * dnp)284 dnode_byteswap(dnode_phys_t *dnp)
285 {
286 uint64_t *buf64 = (void*)&dnp->dn_blkptr;
287 int i;
288
289 if (dnp->dn_type == DMU_OT_NONE) {
290 bzero(dnp, sizeof (dnode_phys_t));
291 return;
292 }
293
294 dnp->dn_datablkszsec = BSWAP_16(dnp->dn_datablkszsec);
295 dnp->dn_bonuslen = BSWAP_16(dnp->dn_bonuslen);
296 dnp->dn_maxblkid = BSWAP_64(dnp->dn_maxblkid);
297 dnp->dn_used = BSWAP_64(dnp->dn_used);
298
299 /*
300 * dn_nblkptr is only one byte, so it's OK to read it in either
301 * byte order. We can't read dn_bouslen.
302 */
303 ASSERT(dnp->dn_indblkshift <= SPA_MAXBLOCKSHIFT);
304 ASSERT(dnp->dn_nblkptr <= DN_MAX_NBLKPTR);
305 for (i = 0; i < dnp->dn_nblkptr * sizeof (blkptr_t)/8; i++)
306 buf64[i] = BSWAP_64(buf64[i]);
307
308 /*
309 * OK to check dn_bonuslen for zero, because it won't matter if
310 * we have the wrong byte order. This is necessary because the
311 * dnode dnode is smaller than a regular dnode.
312 */
313 if (dnp->dn_bonuslen != 0) {
314 /*
315 * Note that the bonus length calculated here may be
316 * longer than the actual bonus buffer. This is because
317 * we always put the bonus buffer after the last block
318 * pointer (instead of packing it against the end of the
319 * dnode buffer).
320 */
321 int off = (dnp->dn_nblkptr-1) * sizeof (blkptr_t);
322 size_t len = DN_MAX_BONUSLEN - off;
323 ASSERT(DMU_OT_IS_VALID(dnp->dn_bonustype));
324 dmu_object_byteswap_t byteswap =
325 DMU_OT_BYTESWAP(dnp->dn_bonustype);
326 dmu_ot_byteswap[byteswap].ob_func(dnp->dn_bonus + off, len);
327 }
328
329 /* Swap SPILL block if we have one */
330 if (dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR)
331 byteswap_uint64_array(&dnp->dn_spill, sizeof (blkptr_t));
332
333 }
334
335 void
dnode_buf_byteswap(void * vbuf,size_t size)336 dnode_buf_byteswap(void *vbuf, size_t size)
337 {
338 dnode_phys_t *buf = vbuf;
339 int i;
340
341 ASSERT3U(sizeof (dnode_phys_t), ==, (1<<DNODE_SHIFT));
342 ASSERT((size & (sizeof (dnode_phys_t)-1)) == 0);
343
344 size >>= DNODE_SHIFT;
345 for (i = 0; i < size; i++) {
346 dnode_byteswap(buf);
347 buf++;
348 }
349 }
350
351 void
dnode_setbonuslen(dnode_t * dn,int newsize,dmu_tx_t * tx)352 dnode_setbonuslen(dnode_t *dn, int newsize, dmu_tx_t *tx)
353 {
354 ASSERT3U(refcount_count(&dn->dn_holds), >=, 1);
355
356 dnode_setdirty(dn, tx);
357 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
358 ASSERT3U(newsize, <=, DN_MAX_BONUSLEN -
359 (dn->dn_nblkptr-1) * sizeof (blkptr_t));
360 dn->dn_bonuslen = newsize;
361 if (newsize == 0)
362 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = DN_ZERO_BONUSLEN;
363 else
364 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = dn->dn_bonuslen;
365 rw_exit(&dn->dn_struct_rwlock);
366 }
367
368 void
dnode_setbonus_type(dnode_t * dn,dmu_object_type_t newtype,dmu_tx_t * tx)369 dnode_setbonus_type(dnode_t *dn, dmu_object_type_t newtype, dmu_tx_t *tx)
370 {
371 ASSERT3U(refcount_count(&dn->dn_holds), >=, 1);
372 dnode_setdirty(dn, tx);
373 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
374 dn->dn_bonustype = newtype;
375 dn->dn_next_bonustype[tx->tx_txg & TXG_MASK] = dn->dn_bonustype;
376 rw_exit(&dn->dn_struct_rwlock);
377 }
378
379 void
dnode_rm_spill(dnode_t * dn,dmu_tx_t * tx)380 dnode_rm_spill(dnode_t *dn, dmu_tx_t *tx)
381 {
382 ASSERT3U(refcount_count(&dn->dn_holds), >=, 1);
383 ASSERT(RW_WRITE_HELD(&dn->dn_struct_rwlock));
384 dnode_setdirty(dn, tx);
385 dn->dn_rm_spillblk[tx->tx_txg&TXG_MASK] = DN_KILL_SPILLBLK;
386 dn->dn_have_spill = B_FALSE;
387 }
388
389 static void
dnode_setdblksz(dnode_t * dn,int size)390 dnode_setdblksz(dnode_t *dn, int size)
391 {
392 ASSERT0(P2PHASE(size, SPA_MINBLOCKSIZE));
393 ASSERT3U(size, <=, SPA_MAXBLOCKSIZE);
394 ASSERT3U(size, >=, SPA_MINBLOCKSIZE);
395 ASSERT3U(size >> SPA_MINBLOCKSHIFT, <,
396 1<<(sizeof (dn->dn_phys->dn_datablkszsec) * 8));
397 dn->dn_datablksz = size;
398 dn->dn_datablkszsec = size >> SPA_MINBLOCKSHIFT;
399 dn->dn_datablkshift = ISP2(size) ? highbit64(size - 1) : 0;
400 }
401
402 static dnode_t *
dnode_create(objset_t * os,dnode_phys_t * dnp,dmu_buf_impl_t * db,uint64_t object,dnode_handle_t * dnh)403 dnode_create(objset_t *os, dnode_phys_t *dnp, dmu_buf_impl_t *db,
404 uint64_t object, dnode_handle_t *dnh)
405 {
406 dnode_t *dn;
407
408 dn = kmem_cache_alloc(dnode_cache, KM_SLEEP);
409 ASSERT(!POINTER_IS_VALID(dn->dn_objset));
410 dn->dn_moved = 0;
411
412 /*
413 * Defer setting dn_objset until the dnode is ready to be a candidate
414 * for the dnode_move() callback.
415 */
416 dn->dn_object = object;
417 dn->dn_dbuf = db;
418 dn->dn_handle = dnh;
419 dn->dn_phys = dnp;
420
421 if (dnp->dn_datablkszsec) {
422 dnode_setdblksz(dn, dnp->dn_datablkszsec << SPA_MINBLOCKSHIFT);
423 } else {
424 dn->dn_datablksz = 0;
425 dn->dn_datablkszsec = 0;
426 dn->dn_datablkshift = 0;
427 }
428 dn->dn_indblkshift = dnp->dn_indblkshift;
429 dn->dn_nlevels = dnp->dn_nlevels;
430 dn->dn_type = dnp->dn_type;
431 dn->dn_nblkptr = dnp->dn_nblkptr;
432 dn->dn_checksum = dnp->dn_checksum;
433 dn->dn_compress = dnp->dn_compress;
434 dn->dn_bonustype = dnp->dn_bonustype;
435 dn->dn_bonuslen = dnp->dn_bonuslen;
436 dn->dn_maxblkid = dnp->dn_maxblkid;
437 dn->dn_have_spill = ((dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) != 0);
438 dn->dn_id_flags = 0;
439
440 dmu_zfetch_init(&dn->dn_zfetch, dn);
441
442 ASSERT(DMU_OT_IS_VALID(dn->dn_phys->dn_type));
443
444 mutex_enter(&os->os_lock);
445 if (dnh->dnh_dnode != NULL) {
446 /* Lost the allocation race. */
447 mutex_exit(&os->os_lock);
448 kmem_cache_free(dnode_cache, dn);
449 return (dnh->dnh_dnode);
450 }
451
452 /*
453 * Exclude special dnodes from os_dnodes so an empty os_dnodes
454 * signifies that the special dnodes have no references from
455 * their children (the entries in os_dnodes). This allows
456 * dnode_destroy() to easily determine if the last child has
457 * been removed and then complete eviction of the objset.
458 */
459 if (!DMU_OBJECT_IS_SPECIAL(object))
460 list_insert_head(&os->os_dnodes, dn);
461 membar_producer();
462
463 /*
464 * Everything else must be valid before assigning dn_objset
465 * makes the dnode eligible for dnode_move().
466 */
467 dn->dn_objset = os;
468
469 dnh->dnh_dnode = dn;
470 mutex_exit(&os->os_lock);
471
472 arc_space_consume(sizeof (dnode_t), ARC_SPACE_OTHER);
473 return (dn);
474 }
475
476 /*
477 * Caller must be holding the dnode handle, which is released upon return.
478 */
479 static void
dnode_destroy(dnode_t * dn)480 dnode_destroy(dnode_t *dn)
481 {
482 objset_t *os = dn->dn_objset;
483 boolean_t complete_os_eviction = B_FALSE;
484
485 ASSERT((dn->dn_id_flags & DN_ID_NEW_EXIST) == 0);
486
487 mutex_enter(&os->os_lock);
488 POINTER_INVALIDATE(&dn->dn_objset);
489 if (!DMU_OBJECT_IS_SPECIAL(dn->dn_object)) {
490 list_remove(&os->os_dnodes, dn);
491 complete_os_eviction =
492 list_is_empty(&os->os_dnodes) &&
493 list_link_active(&os->os_evicting_node);
494 }
495 mutex_exit(&os->os_lock);
496
497 /* the dnode can no longer move, so we can release the handle */
498 zrl_remove(&dn->dn_handle->dnh_zrlock);
499
500 dn->dn_allocated_txg = 0;
501 dn->dn_free_txg = 0;
502 dn->dn_assigned_txg = 0;
503
504 dn->dn_dirtyctx = 0;
505 if (dn->dn_dirtyctx_firstset != NULL) {
506 kmem_free(dn->dn_dirtyctx_firstset, 1);
507 dn->dn_dirtyctx_firstset = NULL;
508 }
509 if (dn->dn_bonus != NULL) {
510 mutex_enter(&dn->dn_bonus->db_mtx);
511 dbuf_evict(dn->dn_bonus);
512 dn->dn_bonus = NULL;
513 }
514 dn->dn_zio = NULL;
515
516 dn->dn_have_spill = B_FALSE;
517 dn->dn_oldused = 0;
518 dn->dn_oldflags = 0;
519 dn->dn_olduid = 0;
520 dn->dn_oldgid = 0;
521 dn->dn_newuid = 0;
522 dn->dn_newgid = 0;
523 dn->dn_id_flags = 0;
524 dn->dn_unlisted_l0_blkid = 0;
525
526 dmu_zfetch_rele(&dn->dn_zfetch);
527 kmem_cache_free(dnode_cache, dn);
528 arc_space_return(sizeof (dnode_t), ARC_SPACE_OTHER);
529
530 if (complete_os_eviction)
531 dmu_objset_evict_done(os);
532 }
533
534 void
dnode_allocate(dnode_t * dn,dmu_object_type_t ot,int blocksize,int ibs,dmu_object_type_t bonustype,int bonuslen,dmu_tx_t * tx)535 dnode_allocate(dnode_t *dn, dmu_object_type_t ot, int blocksize, int ibs,
536 dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx)
537 {
538 int i;
539
540 ASSERT3U(blocksize, <=,
541 spa_maxblocksize(dmu_objset_spa(dn->dn_objset)));
542 if (blocksize == 0)
543 blocksize = 1 << zfs_default_bs;
544 else
545 blocksize = P2ROUNDUP(blocksize, SPA_MINBLOCKSIZE);
546
547 if (ibs == 0)
548 ibs = zfs_default_ibs;
549
550 ibs = MIN(MAX(ibs, DN_MIN_INDBLKSHIFT), DN_MAX_INDBLKSHIFT);
551
552 dprintf("os=%p obj=%llu txg=%llu blocksize=%d ibs=%d\n", dn->dn_objset,
553 dn->dn_object, tx->tx_txg, blocksize, ibs);
554
555 ASSERT(dn->dn_type == DMU_OT_NONE);
556 ASSERT(bcmp(dn->dn_phys, &dnode_phys_zero, sizeof (dnode_phys_t)) == 0);
557 ASSERT(dn->dn_phys->dn_type == DMU_OT_NONE);
558 ASSERT(ot != DMU_OT_NONE);
559 ASSERT(DMU_OT_IS_VALID(ot));
560 ASSERT((bonustype == DMU_OT_NONE && bonuslen == 0) ||
561 (bonustype == DMU_OT_SA && bonuslen == 0) ||
562 (bonustype != DMU_OT_NONE && bonuslen != 0));
563 ASSERT(DMU_OT_IS_VALID(bonustype));
564 ASSERT3U(bonuslen, <=, DN_MAX_BONUSLEN);
565 ASSERT(dn->dn_type == DMU_OT_NONE);
566 ASSERT0(dn->dn_maxblkid);
567 ASSERT0(dn->dn_allocated_txg);
568 ASSERT0(dn->dn_assigned_txg);
569 ASSERT(refcount_is_zero(&dn->dn_tx_holds));
570 ASSERT3U(refcount_count(&dn->dn_holds), <=, 1);
571 ASSERT(avl_is_empty(&dn->dn_dbufs));
572
573 for (i = 0; i < TXG_SIZE; i++) {
574 ASSERT0(dn->dn_next_nblkptr[i]);
575 ASSERT0(dn->dn_next_nlevels[i]);
576 ASSERT0(dn->dn_next_indblkshift[i]);
577 ASSERT0(dn->dn_next_bonuslen[i]);
578 ASSERT0(dn->dn_next_bonustype[i]);
579 ASSERT0(dn->dn_rm_spillblk[i]);
580 ASSERT0(dn->dn_next_blksz[i]);
581 ASSERT(!list_link_active(&dn->dn_dirty_link[i]));
582 ASSERT3P(list_head(&dn->dn_dirty_records[i]), ==, NULL);
583 ASSERT3P(dn->dn_free_ranges[i], ==, NULL);
584 }
585
586 dn->dn_type = ot;
587 dnode_setdblksz(dn, blocksize);
588 dn->dn_indblkshift = ibs;
589 dn->dn_nlevels = 1;
590 if (bonustype == DMU_OT_SA) /* Maximize bonus space for SA */
591 dn->dn_nblkptr = 1;
592 else
593 dn->dn_nblkptr = 1 +
594 ((DN_MAX_BONUSLEN - bonuslen) >> SPA_BLKPTRSHIFT);
595 dn->dn_bonustype = bonustype;
596 dn->dn_bonuslen = bonuslen;
597 dn->dn_checksum = ZIO_CHECKSUM_INHERIT;
598 dn->dn_compress = ZIO_COMPRESS_INHERIT;
599 dn->dn_dirtyctx = 0;
600
601 dn->dn_free_txg = 0;
602 if (dn->dn_dirtyctx_firstset) {
603 kmem_free(dn->dn_dirtyctx_firstset, 1);
604 dn->dn_dirtyctx_firstset = NULL;
605 }
606
607 dn->dn_allocated_txg = tx->tx_txg;
608 dn->dn_id_flags = 0;
609
610 dnode_setdirty(dn, tx);
611 dn->dn_next_indblkshift[tx->tx_txg & TXG_MASK] = ibs;
612 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = dn->dn_bonuslen;
613 dn->dn_next_bonustype[tx->tx_txg & TXG_MASK] = dn->dn_bonustype;
614 dn->dn_next_blksz[tx->tx_txg & TXG_MASK] = dn->dn_datablksz;
615 }
616
617 void
dnode_reallocate(dnode_t * dn,dmu_object_type_t ot,int blocksize,dmu_object_type_t bonustype,int bonuslen,dmu_tx_t * tx)618 dnode_reallocate(dnode_t *dn, dmu_object_type_t ot, int blocksize,
619 dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx)
620 {
621 int nblkptr;
622
623 ASSERT3U(blocksize, >=, SPA_MINBLOCKSIZE);
624 ASSERT3U(blocksize, <=,
625 spa_maxblocksize(dmu_objset_spa(dn->dn_objset)));
626 ASSERT0(blocksize % SPA_MINBLOCKSIZE);
627 ASSERT(dn->dn_object != DMU_META_DNODE_OBJECT || dmu_tx_private_ok(tx));
628 ASSERT(tx->tx_txg != 0);
629 ASSERT((bonustype == DMU_OT_NONE && bonuslen == 0) ||
630 (bonustype != DMU_OT_NONE && bonuslen != 0) ||
631 (bonustype == DMU_OT_SA && bonuslen == 0));
632 ASSERT(DMU_OT_IS_VALID(bonustype));
633 ASSERT3U(bonuslen, <=, DN_MAX_BONUSLEN);
634
635 /* clean up any unreferenced dbufs */
636 dnode_evict_dbufs(dn);
637
638 dn->dn_id_flags = 0;
639
640 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
641 dnode_setdirty(dn, tx);
642 if (dn->dn_datablksz != blocksize) {
643 /* change blocksize */
644 ASSERT(dn->dn_maxblkid == 0 &&
645 (BP_IS_HOLE(&dn->dn_phys->dn_blkptr[0]) ||
646 dnode_block_freed(dn, 0)));
647 dnode_setdblksz(dn, blocksize);
648 dn->dn_next_blksz[tx->tx_txg&TXG_MASK] = blocksize;
649 }
650 if (dn->dn_bonuslen != bonuslen)
651 dn->dn_next_bonuslen[tx->tx_txg&TXG_MASK] = bonuslen;
652
653 if (bonustype == DMU_OT_SA) /* Maximize bonus space for SA */
654 nblkptr = 1;
655 else
656 nblkptr = 1 + ((DN_MAX_BONUSLEN - bonuslen) >> SPA_BLKPTRSHIFT);
657 if (dn->dn_bonustype != bonustype)
658 dn->dn_next_bonustype[tx->tx_txg&TXG_MASK] = bonustype;
659 if (dn->dn_nblkptr != nblkptr)
660 dn->dn_next_nblkptr[tx->tx_txg&TXG_MASK] = nblkptr;
661 if (dn->dn_phys->dn_flags & DNODE_FLAG_SPILL_BLKPTR) {
662 dbuf_rm_spill(dn, tx);
663 dnode_rm_spill(dn, tx);
664 }
665 rw_exit(&dn->dn_struct_rwlock);
666
667 /* change type */
668 dn->dn_type = ot;
669
670 /* change bonus size and type */
671 mutex_enter(&dn->dn_mtx);
672 dn->dn_bonustype = bonustype;
673 dn->dn_bonuslen = bonuslen;
674 dn->dn_nblkptr = nblkptr;
675 dn->dn_checksum = ZIO_CHECKSUM_INHERIT;
676 dn->dn_compress = ZIO_COMPRESS_INHERIT;
677 ASSERT3U(dn->dn_nblkptr, <=, DN_MAX_NBLKPTR);
678
679 /* fix up the bonus db_size */
680 if (dn->dn_bonus) {
681 dn->dn_bonus->db.db_size =
682 DN_MAX_BONUSLEN - (dn->dn_nblkptr-1) * sizeof (blkptr_t);
683 ASSERT(dn->dn_bonuslen <= dn->dn_bonus->db.db_size);
684 }
685
686 dn->dn_allocated_txg = tx->tx_txg;
687 mutex_exit(&dn->dn_mtx);
688 }
689
690 #ifdef DNODE_STATS
691 static struct {
692 uint64_t dms_dnode_invalid;
693 uint64_t dms_dnode_recheck1;
694 uint64_t dms_dnode_recheck2;
695 uint64_t dms_dnode_special;
696 uint64_t dms_dnode_handle;
697 uint64_t dms_dnode_rwlock;
698 uint64_t dms_dnode_active;
699 } dnode_move_stats;
700 #endif /* DNODE_STATS */
701
702 static void
dnode_move_impl(dnode_t * odn,dnode_t * ndn)703 dnode_move_impl(dnode_t *odn, dnode_t *ndn)
704 {
705 int i;
706
707 ASSERT(!RW_LOCK_HELD(&odn->dn_struct_rwlock));
708 ASSERT(MUTEX_NOT_HELD(&odn->dn_mtx));
709 ASSERT(MUTEX_NOT_HELD(&odn->dn_dbufs_mtx));
710 ASSERT(!RW_LOCK_HELD(&odn->dn_zfetch.zf_rwlock));
711
712 /* Copy fields. */
713 ndn->dn_objset = odn->dn_objset;
714 ndn->dn_object = odn->dn_object;
715 ndn->dn_dbuf = odn->dn_dbuf;
716 ndn->dn_handle = odn->dn_handle;
717 ndn->dn_phys = odn->dn_phys;
718 ndn->dn_type = odn->dn_type;
719 ndn->dn_bonuslen = odn->dn_bonuslen;
720 ndn->dn_bonustype = odn->dn_bonustype;
721 ndn->dn_nblkptr = odn->dn_nblkptr;
722 ndn->dn_checksum = odn->dn_checksum;
723 ndn->dn_compress = odn->dn_compress;
724 ndn->dn_nlevels = odn->dn_nlevels;
725 ndn->dn_indblkshift = odn->dn_indblkshift;
726 ndn->dn_datablkshift = odn->dn_datablkshift;
727 ndn->dn_datablkszsec = odn->dn_datablkszsec;
728 ndn->dn_datablksz = odn->dn_datablksz;
729 ndn->dn_maxblkid = odn->dn_maxblkid;
730 bcopy(&odn->dn_next_nblkptr[0], &ndn->dn_next_nblkptr[0],
731 sizeof (odn->dn_next_nblkptr));
732 bcopy(&odn->dn_next_nlevels[0], &ndn->dn_next_nlevels[0],
733 sizeof (odn->dn_next_nlevels));
734 bcopy(&odn->dn_next_indblkshift[0], &ndn->dn_next_indblkshift[0],
735 sizeof (odn->dn_next_indblkshift));
736 bcopy(&odn->dn_next_bonustype[0], &ndn->dn_next_bonustype[0],
737 sizeof (odn->dn_next_bonustype));
738 bcopy(&odn->dn_rm_spillblk[0], &ndn->dn_rm_spillblk[0],
739 sizeof (odn->dn_rm_spillblk));
740 bcopy(&odn->dn_next_bonuslen[0], &ndn->dn_next_bonuslen[0],
741 sizeof (odn->dn_next_bonuslen));
742 bcopy(&odn->dn_next_blksz[0], &ndn->dn_next_blksz[0],
743 sizeof (odn->dn_next_blksz));
744 for (i = 0; i < TXG_SIZE; i++) {
745 list_move_tail(&ndn->dn_dirty_records[i],
746 &odn->dn_dirty_records[i]);
747 }
748 bcopy(&odn->dn_free_ranges[0], &ndn->dn_free_ranges[0],
749 sizeof (odn->dn_free_ranges));
750 ndn->dn_allocated_txg = odn->dn_allocated_txg;
751 ndn->dn_free_txg = odn->dn_free_txg;
752 ndn->dn_assigned_txg = odn->dn_assigned_txg;
753 ndn->dn_dirtyctx = odn->dn_dirtyctx;
754 ndn->dn_dirtyctx_firstset = odn->dn_dirtyctx_firstset;
755 ASSERT(refcount_count(&odn->dn_tx_holds) == 0);
756 refcount_transfer(&ndn->dn_holds, &odn->dn_holds);
757 ASSERT(avl_is_empty(&ndn->dn_dbufs));
758 avl_swap(&ndn->dn_dbufs, &odn->dn_dbufs);
759 ndn->dn_dbufs_count = odn->dn_dbufs_count;
760 ndn->dn_unlisted_l0_blkid = odn->dn_unlisted_l0_blkid;
761 ndn->dn_bonus = odn->dn_bonus;
762 ndn->dn_have_spill = odn->dn_have_spill;
763 ndn->dn_zio = odn->dn_zio;
764 ndn->dn_oldused = odn->dn_oldused;
765 ndn->dn_oldflags = odn->dn_oldflags;
766 ndn->dn_olduid = odn->dn_olduid;
767 ndn->dn_oldgid = odn->dn_oldgid;
768 ndn->dn_newuid = odn->dn_newuid;
769 ndn->dn_newgid = odn->dn_newgid;
770 ndn->dn_id_flags = odn->dn_id_flags;
771 dmu_zfetch_init(&ndn->dn_zfetch, NULL);
772 list_move_tail(&ndn->dn_zfetch.zf_stream, &odn->dn_zfetch.zf_stream);
773 ndn->dn_zfetch.zf_dnode = odn->dn_zfetch.zf_dnode;
774 ndn->dn_zfetch.zf_stream_cnt = odn->dn_zfetch.zf_stream_cnt;
775 ndn->dn_zfetch.zf_alloc_fail = odn->dn_zfetch.zf_alloc_fail;
776
777 /*
778 * Update back pointers. Updating the handle fixes the back pointer of
779 * every descendant dbuf as well as the bonus dbuf.
780 */
781 ASSERT(ndn->dn_handle->dnh_dnode == odn);
782 ndn->dn_handle->dnh_dnode = ndn;
783 if (ndn->dn_zfetch.zf_dnode == odn) {
784 ndn->dn_zfetch.zf_dnode = ndn;
785 }
786
787 /*
788 * Invalidate the original dnode by clearing all of its back pointers.
789 */
790 odn->dn_dbuf = NULL;
791 odn->dn_handle = NULL;
792 avl_create(&odn->dn_dbufs, dbuf_compare, sizeof (dmu_buf_impl_t),
793 offsetof(dmu_buf_impl_t, db_link));
794 odn->dn_dbufs_count = 0;
795 odn->dn_unlisted_l0_blkid = 0;
796 odn->dn_bonus = NULL;
797 odn->dn_zfetch.zf_dnode = NULL;
798
799 /*
800 * Set the low bit of the objset pointer to ensure that dnode_move()
801 * recognizes the dnode as invalid in any subsequent callback.
802 */
803 POINTER_INVALIDATE(&odn->dn_objset);
804
805 /*
806 * Satisfy the destructor.
807 */
808 for (i = 0; i < TXG_SIZE; i++) {
809 list_create(&odn->dn_dirty_records[i],
810 sizeof (dbuf_dirty_record_t),
811 offsetof(dbuf_dirty_record_t, dr_dirty_node));
812 odn->dn_free_ranges[i] = NULL;
813 odn->dn_next_nlevels[i] = 0;
814 odn->dn_next_indblkshift[i] = 0;
815 odn->dn_next_bonustype[i] = 0;
816 odn->dn_rm_spillblk[i] = 0;
817 odn->dn_next_bonuslen[i] = 0;
818 odn->dn_next_blksz[i] = 0;
819 }
820 odn->dn_allocated_txg = 0;
821 odn->dn_free_txg = 0;
822 odn->dn_assigned_txg = 0;
823 odn->dn_dirtyctx = 0;
824 odn->dn_dirtyctx_firstset = NULL;
825 odn->dn_have_spill = B_FALSE;
826 odn->dn_zio = NULL;
827 odn->dn_oldused = 0;
828 odn->dn_oldflags = 0;
829 odn->dn_olduid = 0;
830 odn->dn_oldgid = 0;
831 odn->dn_newuid = 0;
832 odn->dn_newgid = 0;
833 odn->dn_id_flags = 0;
834
835 /*
836 * Mark the dnode.
837 */
838 ndn->dn_moved = 1;
839 odn->dn_moved = (uint8_t)-1;
840 }
841
842 #ifdef _KERNEL
843 /*ARGSUSED*/
844 static kmem_cbrc_t
dnode_move(void * buf,void * newbuf,size_t size,void * arg)845 dnode_move(void *buf, void *newbuf, size_t size, void *arg)
846 {
847 dnode_t *odn = buf, *ndn = newbuf;
848 objset_t *os;
849 int64_t refcount;
850 uint32_t dbufs;
851
852 /*
853 * The dnode is on the objset's list of known dnodes if the objset
854 * pointer is valid. We set the low bit of the objset pointer when
855 * freeing the dnode to invalidate it, and the memory patterns written
856 * by kmem (baddcafe and deadbeef) set at least one of the two low bits.
857 * A newly created dnode sets the objset pointer last of all to indicate
858 * that the dnode is known and in a valid state to be moved by this
859 * function.
860 */
861 os = odn->dn_objset;
862 if (!POINTER_IS_VALID(os)) {
863 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_invalid);
864 return (KMEM_CBRC_DONT_KNOW);
865 }
866
867 /*
868 * Ensure that the objset does not go away during the move.
869 */
870 rw_enter(&os_lock, RW_WRITER);
871 if (os != odn->dn_objset) {
872 rw_exit(&os_lock);
873 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_recheck1);
874 return (KMEM_CBRC_DONT_KNOW);
875 }
876
877 /*
878 * If the dnode is still valid, then so is the objset. We know that no
879 * valid objset can be freed while we hold os_lock, so we can safely
880 * ensure that the objset remains in use.
881 */
882 mutex_enter(&os->os_lock);
883
884 /*
885 * Recheck the objset pointer in case the dnode was removed just before
886 * acquiring the lock.
887 */
888 if (os != odn->dn_objset) {
889 mutex_exit(&os->os_lock);
890 rw_exit(&os_lock);
891 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_recheck2);
892 return (KMEM_CBRC_DONT_KNOW);
893 }
894
895 /*
896 * At this point we know that as long as we hold os->os_lock, the dnode
897 * cannot be freed and fields within the dnode can be safely accessed.
898 * The objset listing this dnode cannot go away as long as this dnode is
899 * on its list.
900 */
901 rw_exit(&os_lock);
902 if (DMU_OBJECT_IS_SPECIAL(odn->dn_object)) {
903 mutex_exit(&os->os_lock);
904 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_special);
905 return (KMEM_CBRC_NO);
906 }
907 ASSERT(odn->dn_dbuf != NULL); /* only "special" dnodes have no parent */
908
909 /*
910 * Lock the dnode handle to prevent the dnode from obtaining any new
911 * holds. This also prevents the descendant dbufs and the bonus dbuf
912 * from accessing the dnode, so that we can discount their holds. The
913 * handle is safe to access because we know that while the dnode cannot
914 * go away, neither can its handle. Once we hold dnh_zrlock, we can
915 * safely move any dnode referenced only by dbufs.
916 */
917 if (!zrl_tryenter(&odn->dn_handle->dnh_zrlock)) {
918 mutex_exit(&os->os_lock);
919 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_handle);
920 return (KMEM_CBRC_LATER);
921 }
922
923 /*
924 * Ensure a consistent view of the dnode's holds and the dnode's dbufs.
925 * We need to guarantee that there is a hold for every dbuf in order to
926 * determine whether the dnode is actively referenced. Falsely matching
927 * a dbuf to an active hold would lead to an unsafe move. It's possible
928 * that a thread already having an active dnode hold is about to add a
929 * dbuf, and we can't compare hold and dbuf counts while the add is in
930 * progress.
931 */
932 if (!rw_tryenter(&odn->dn_struct_rwlock, RW_WRITER)) {
933 zrl_exit(&odn->dn_handle->dnh_zrlock);
934 mutex_exit(&os->os_lock);
935 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_rwlock);
936 return (KMEM_CBRC_LATER);
937 }
938
939 /*
940 * A dbuf may be removed (evicted) without an active dnode hold. In that
941 * case, the dbuf count is decremented under the handle lock before the
942 * dbuf's hold is released. This order ensures that if we count the hold
943 * after the dbuf is removed but before its hold is released, we will
944 * treat the unmatched hold as active and exit safely. If we count the
945 * hold before the dbuf is removed, the hold is discounted, and the
946 * removal is blocked until the move completes.
947 */
948 refcount = refcount_count(&odn->dn_holds);
949 ASSERT(refcount >= 0);
950 dbufs = odn->dn_dbufs_count;
951
952 /* We can't have more dbufs than dnode holds. */
953 ASSERT3U(dbufs, <=, refcount);
954 DTRACE_PROBE3(dnode__move, dnode_t *, odn, int64_t, refcount,
955 uint32_t, dbufs);
956
957 if (refcount > dbufs) {
958 rw_exit(&odn->dn_struct_rwlock);
959 zrl_exit(&odn->dn_handle->dnh_zrlock);
960 mutex_exit(&os->os_lock);
961 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_active);
962 return (KMEM_CBRC_LATER);
963 }
964
965 rw_exit(&odn->dn_struct_rwlock);
966
967 /*
968 * At this point we know that anyone with a hold on the dnode is not
969 * actively referencing it. The dnode is known and in a valid state to
970 * move. We're holding the locks needed to execute the critical section.
971 */
972 dnode_move_impl(odn, ndn);
973
974 list_link_replace(&odn->dn_link, &ndn->dn_link);
975 /* If the dnode was safe to move, the refcount cannot have changed. */
976 ASSERT(refcount == refcount_count(&ndn->dn_holds));
977 ASSERT(dbufs == ndn->dn_dbufs_count);
978 zrl_exit(&ndn->dn_handle->dnh_zrlock); /* handle has moved */
979 mutex_exit(&os->os_lock);
980
981 return (KMEM_CBRC_YES);
982 }
983 #endif /* _KERNEL */
984
985 void
dnode_special_close(dnode_handle_t * dnh)986 dnode_special_close(dnode_handle_t *dnh)
987 {
988 dnode_t *dn = dnh->dnh_dnode;
989
990 /*
991 * Wait for final references to the dnode to clear. This can
992 * only happen if the arc is asyncronously evicting state that
993 * has a hold on this dnode while we are trying to evict this
994 * dnode.
995 */
996 while (refcount_count(&dn->dn_holds) > 0)
997 delay(1);
998 ASSERT(dn->dn_dbuf == NULL ||
999 dmu_buf_get_user(&dn->dn_dbuf->db) == NULL);
1000 zrl_add(&dnh->dnh_zrlock);
1001 dnode_destroy(dn); /* implicit zrl_remove() */
1002 zrl_destroy(&dnh->dnh_zrlock);
1003 dnh->dnh_dnode = NULL;
1004 }
1005
1006 void
dnode_special_open(objset_t * os,dnode_phys_t * dnp,uint64_t object,dnode_handle_t * dnh)1007 dnode_special_open(objset_t *os, dnode_phys_t *dnp, uint64_t object,
1008 dnode_handle_t *dnh)
1009 {
1010 dnode_t *dn;
1011
1012 dn = dnode_create(os, dnp, NULL, object, dnh);
1013 zrl_init(&dnh->dnh_zrlock);
1014 DNODE_VERIFY(dn);
1015 }
1016
1017 static void
dnode_buf_evict_async(void * dbu)1018 dnode_buf_evict_async(void *dbu)
1019 {
1020 dnode_children_t *children_dnodes = dbu;
1021 int i;
1022
1023 for (i = 0; i < children_dnodes->dnc_count; i++) {
1024 dnode_handle_t *dnh = &children_dnodes->dnc_children[i];
1025 dnode_t *dn;
1026
1027 /*
1028 * The dnode handle lock guards against the dnode moving to
1029 * another valid address, so there is no need here to guard
1030 * against changes to or from NULL.
1031 */
1032 if (dnh->dnh_dnode == NULL) {
1033 zrl_destroy(&dnh->dnh_zrlock);
1034 continue;
1035 }
1036
1037 zrl_add(&dnh->dnh_zrlock);
1038 dn = dnh->dnh_dnode;
1039 /*
1040 * If there are holds on this dnode, then there should
1041 * be holds on the dnode's containing dbuf as well; thus
1042 * it wouldn't be eligible for eviction and this function
1043 * would not have been called.
1044 */
1045 ASSERT(refcount_is_zero(&dn->dn_holds));
1046 ASSERT(refcount_is_zero(&dn->dn_tx_holds));
1047
1048 dnode_destroy(dn); /* implicit zrl_remove() */
1049 zrl_destroy(&dnh->dnh_zrlock);
1050 dnh->dnh_dnode = NULL;
1051 }
1052 kmem_free(children_dnodes, sizeof (dnode_children_t) +
1053 children_dnodes->dnc_count * sizeof (dnode_handle_t));
1054 }
1055
1056 /*
1057 * errors:
1058 * EINVAL - invalid object number.
1059 * EIO - i/o error.
1060 * succeeds even for free dnodes.
1061 */
1062 int
dnode_hold_impl(objset_t * os,uint64_t object,int flag,void * tag,dnode_t ** dnp)1063 dnode_hold_impl(objset_t *os, uint64_t object, int flag,
1064 void *tag, dnode_t **dnp)
1065 {
1066 int epb, idx, err;
1067 int drop_struct_lock = FALSE;
1068 int type;
1069 uint64_t blk;
1070 dnode_t *mdn, *dn;
1071 dmu_buf_impl_t *db;
1072 dnode_children_t *children_dnodes;
1073 dnode_handle_t *dnh;
1074
1075 /*
1076 * If you are holding the spa config lock as writer, you shouldn't
1077 * be asking the DMU to do *anything* unless it's the root pool
1078 * which may require us to read from the root filesystem while
1079 * holding some (not all) of the locks as writer.
1080 */
1081 ASSERT(spa_config_held(os->os_spa, SCL_ALL, RW_WRITER) == 0 ||
1082 (spa_is_root(os->os_spa) &&
1083 spa_config_held(os->os_spa, SCL_STATE, RW_WRITER)));
1084
1085 if (object == DMU_USERUSED_OBJECT || object == DMU_GROUPUSED_OBJECT) {
1086 dn = (object == DMU_USERUSED_OBJECT) ?
1087 DMU_USERUSED_DNODE(os) : DMU_GROUPUSED_DNODE(os);
1088 if (dn == NULL)
1089 return (SET_ERROR(ENOENT));
1090 type = dn->dn_type;
1091 if ((flag & DNODE_MUST_BE_ALLOCATED) && type == DMU_OT_NONE)
1092 return (SET_ERROR(ENOENT));
1093 if ((flag & DNODE_MUST_BE_FREE) && type != DMU_OT_NONE)
1094 return (SET_ERROR(EEXIST));
1095 DNODE_VERIFY(dn);
1096 (void) refcount_add(&dn->dn_holds, tag);
1097 *dnp = dn;
1098 return (0);
1099 }
1100
1101 if (object == 0 || object >= DN_MAX_OBJECT)
1102 return (SET_ERROR(EINVAL));
1103
1104 mdn = DMU_META_DNODE(os);
1105 ASSERT(mdn->dn_object == DMU_META_DNODE_OBJECT);
1106
1107 DNODE_VERIFY(mdn);
1108
1109 if (!RW_WRITE_HELD(&mdn->dn_struct_rwlock)) {
1110 rw_enter(&mdn->dn_struct_rwlock, RW_READER);
1111 drop_struct_lock = TRUE;
1112 }
1113
1114 blk = dbuf_whichblock(mdn, 0, object * sizeof (dnode_phys_t));
1115
1116 db = dbuf_hold(mdn, blk, FTAG);
1117 if (drop_struct_lock)
1118 rw_exit(&mdn->dn_struct_rwlock);
1119 if (db == NULL)
1120 return (SET_ERROR(EIO));
1121 err = dbuf_read(db, NULL, DB_RF_CANFAIL);
1122 if (err) {
1123 dbuf_rele(db, FTAG);
1124 return (err);
1125 }
1126
1127 ASSERT3U(db->db.db_size, >=, 1<<DNODE_SHIFT);
1128 epb = db->db.db_size >> DNODE_SHIFT;
1129
1130 idx = object & (epb-1);
1131
1132 ASSERT(DB_DNODE(db)->dn_type == DMU_OT_DNODE);
1133 children_dnodes = dmu_buf_get_user(&db->db);
1134 if (children_dnodes == NULL) {
1135 int i;
1136 dnode_children_t *winner;
1137 children_dnodes = kmem_zalloc(sizeof (dnode_children_t) +
1138 epb * sizeof (dnode_handle_t), KM_SLEEP);
1139 children_dnodes->dnc_count = epb;
1140 dnh = &children_dnodes->dnc_children[0];
1141 for (i = 0; i < epb; i++) {
1142 zrl_init(&dnh[i].dnh_zrlock);
1143 }
1144 dmu_buf_init_user(&children_dnodes->dnc_dbu, NULL,
1145 dnode_buf_evict_async, NULL);
1146 winner = dmu_buf_set_user(&db->db, &children_dnodes->dnc_dbu);
1147 if (winner != NULL) {
1148
1149 for (i = 0; i < epb; i++) {
1150 zrl_destroy(&dnh[i].dnh_zrlock);
1151 }
1152
1153 kmem_free(children_dnodes, sizeof (dnode_children_t) +
1154 epb * sizeof (dnode_handle_t));
1155 children_dnodes = winner;
1156 }
1157 }
1158 ASSERT(children_dnodes->dnc_count == epb);
1159
1160 dnh = &children_dnodes->dnc_children[idx];
1161 zrl_add(&dnh->dnh_zrlock);
1162 dn = dnh->dnh_dnode;
1163 if (dn == NULL) {
1164 dnode_phys_t *phys = (dnode_phys_t *)db->db.db_data+idx;
1165
1166 dn = dnode_create(os, phys, db, object, dnh);
1167 }
1168
1169 mutex_enter(&dn->dn_mtx);
1170 type = dn->dn_type;
1171 if (dn->dn_free_txg ||
1172 ((flag & DNODE_MUST_BE_ALLOCATED) && type == DMU_OT_NONE) ||
1173 ((flag & DNODE_MUST_BE_FREE) &&
1174 (type != DMU_OT_NONE || !refcount_is_zero(&dn->dn_holds)))) {
1175 mutex_exit(&dn->dn_mtx);
1176 zrl_remove(&dnh->dnh_zrlock);
1177 dbuf_rele(db, FTAG);
1178 return (type == DMU_OT_NONE ? ENOENT : EEXIST);
1179 }
1180 if (refcount_add(&dn->dn_holds, tag) == 1)
1181 dbuf_add_ref(db, dnh);
1182 mutex_exit(&dn->dn_mtx);
1183
1184 /* Now we can rely on the hold to prevent the dnode from moving. */
1185 zrl_remove(&dnh->dnh_zrlock);
1186
1187 DNODE_VERIFY(dn);
1188 ASSERT3P(dn->dn_dbuf, ==, db);
1189 ASSERT3U(dn->dn_object, ==, object);
1190 dbuf_rele(db, FTAG);
1191
1192 *dnp = dn;
1193 return (0);
1194 }
1195
1196 /*
1197 * Return held dnode if the object is allocated, NULL if not.
1198 */
1199 int
dnode_hold(objset_t * os,uint64_t object,void * tag,dnode_t ** dnp)1200 dnode_hold(objset_t *os, uint64_t object, void *tag, dnode_t **dnp)
1201 {
1202 return (dnode_hold_impl(os, object, DNODE_MUST_BE_ALLOCATED, tag, dnp));
1203 }
1204
1205 /*
1206 * Can only add a reference if there is already at least one
1207 * reference on the dnode. Returns FALSE if unable to add a
1208 * new reference.
1209 */
1210 boolean_t
dnode_add_ref(dnode_t * dn,void * tag)1211 dnode_add_ref(dnode_t *dn, void *tag)
1212 {
1213 mutex_enter(&dn->dn_mtx);
1214 if (refcount_is_zero(&dn->dn_holds)) {
1215 mutex_exit(&dn->dn_mtx);
1216 return (FALSE);
1217 }
1218 VERIFY(1 < refcount_add(&dn->dn_holds, tag));
1219 mutex_exit(&dn->dn_mtx);
1220 return (TRUE);
1221 }
1222
1223 void
dnode_rele(dnode_t * dn,void * tag)1224 dnode_rele(dnode_t *dn, void *tag)
1225 {
1226 mutex_enter(&dn->dn_mtx);
1227 dnode_rele_and_unlock(dn, tag);
1228 }
1229
1230 void
dnode_rele_and_unlock(dnode_t * dn,void * tag)1231 dnode_rele_and_unlock(dnode_t *dn, void *tag)
1232 {
1233 uint64_t refs;
1234 /* Get while the hold prevents the dnode from moving. */
1235 dmu_buf_impl_t *db = dn->dn_dbuf;
1236 dnode_handle_t *dnh = dn->dn_handle;
1237
1238 refs = refcount_remove(&dn->dn_holds, tag);
1239 mutex_exit(&dn->dn_mtx);
1240
1241 /*
1242 * It's unsafe to release the last hold on a dnode by dnode_rele() or
1243 * indirectly by dbuf_rele() while relying on the dnode handle to
1244 * prevent the dnode from moving, since releasing the last hold could
1245 * result in the dnode's parent dbuf evicting its dnode handles. For
1246 * that reason anyone calling dnode_rele() or dbuf_rele() without some
1247 * other direct or indirect hold on the dnode must first drop the dnode
1248 * handle.
1249 */
1250 ASSERT(refs > 0 || dnh->dnh_zrlock.zr_owner != curthread);
1251
1252 /* NOTE: the DNODE_DNODE does not have a dn_dbuf */
1253 if (refs == 0 && db != NULL) {
1254 /*
1255 * Another thread could add a hold to the dnode handle in
1256 * dnode_hold_impl() while holding the parent dbuf. Since the
1257 * hold on the parent dbuf prevents the handle from being
1258 * destroyed, the hold on the handle is OK. We can't yet assert
1259 * that the handle has zero references, but that will be
1260 * asserted anyway when the handle gets destroyed.
1261 */
1262 dbuf_rele(db, dnh);
1263 }
1264 }
1265
1266 void
dnode_setdirty(dnode_t * dn,dmu_tx_t * tx)1267 dnode_setdirty(dnode_t *dn, dmu_tx_t *tx)
1268 {
1269 objset_t *os = dn->dn_objset;
1270 uint64_t txg = tx->tx_txg;
1271
1272 if (DMU_OBJECT_IS_SPECIAL(dn->dn_object)) {
1273 dsl_dataset_dirty(os->os_dsl_dataset, tx);
1274 return;
1275 }
1276
1277 DNODE_VERIFY(dn);
1278
1279 #ifdef ZFS_DEBUG
1280 mutex_enter(&dn->dn_mtx);
1281 ASSERT(dn->dn_phys->dn_type || dn->dn_allocated_txg);
1282 ASSERT(dn->dn_free_txg == 0 || dn->dn_free_txg >= txg);
1283 mutex_exit(&dn->dn_mtx);
1284 #endif
1285
1286 /*
1287 * Determine old uid/gid when necessary
1288 */
1289 dmu_objset_userquota_get_ids(dn, B_TRUE, tx);
1290
1291 mutex_enter(&os->os_lock);
1292
1293 /*
1294 * If we are already marked dirty, we're done.
1295 */
1296 if (list_link_active(&dn->dn_dirty_link[txg & TXG_MASK])) {
1297 mutex_exit(&os->os_lock);
1298 return;
1299 }
1300
1301 ASSERT(!refcount_is_zero(&dn->dn_holds) ||
1302 !avl_is_empty(&dn->dn_dbufs));
1303 ASSERT(dn->dn_datablksz != 0);
1304 ASSERT0(dn->dn_next_bonuslen[txg&TXG_MASK]);
1305 ASSERT0(dn->dn_next_blksz[txg&TXG_MASK]);
1306 ASSERT0(dn->dn_next_bonustype[txg&TXG_MASK]);
1307
1308 dprintf_ds(os->os_dsl_dataset, "obj=%llu txg=%llu\n",
1309 dn->dn_object, txg);
1310
1311 if (dn->dn_free_txg > 0 && dn->dn_free_txg <= txg) {
1312 list_insert_tail(&os->os_free_dnodes[txg&TXG_MASK], dn);
1313 } else {
1314 list_insert_tail(&os->os_dirty_dnodes[txg&TXG_MASK], dn);
1315 }
1316
1317 mutex_exit(&os->os_lock);
1318
1319 /*
1320 * The dnode maintains a hold on its containing dbuf as
1321 * long as there are holds on it. Each instantiated child
1322 * dbuf maintains a hold on the dnode. When the last child
1323 * drops its hold, the dnode will drop its hold on the
1324 * containing dbuf. We add a "dirty hold" here so that the
1325 * dnode will hang around after we finish processing its
1326 * children.
1327 */
1328 VERIFY(dnode_add_ref(dn, (void *)(uintptr_t)tx->tx_txg));
1329
1330 (void) dbuf_dirty(dn->dn_dbuf, tx);
1331
1332 dsl_dataset_dirty(os->os_dsl_dataset, tx);
1333 }
1334
1335 void
dnode_free(dnode_t * dn,dmu_tx_t * tx)1336 dnode_free(dnode_t *dn, dmu_tx_t *tx)
1337 {
1338 int txgoff = tx->tx_txg & TXG_MASK;
1339
1340 dprintf("dn=%p txg=%llu\n", dn, tx->tx_txg);
1341
1342 /* we should be the only holder... hopefully */
1343 /* ASSERT3U(refcount_count(&dn->dn_holds), ==, 1); */
1344
1345 mutex_enter(&dn->dn_mtx);
1346 if (dn->dn_type == DMU_OT_NONE || dn->dn_free_txg) {
1347 mutex_exit(&dn->dn_mtx);
1348 return;
1349 }
1350 dn->dn_free_txg = tx->tx_txg;
1351 mutex_exit(&dn->dn_mtx);
1352
1353 /*
1354 * If the dnode is already dirty, it needs to be moved from
1355 * the dirty list to the free list.
1356 */
1357 mutex_enter(&dn->dn_objset->os_lock);
1358 if (list_link_active(&dn->dn_dirty_link[txgoff])) {
1359 list_remove(&dn->dn_objset->os_dirty_dnodes[txgoff], dn);
1360 list_insert_tail(&dn->dn_objset->os_free_dnodes[txgoff], dn);
1361 mutex_exit(&dn->dn_objset->os_lock);
1362 } else {
1363 mutex_exit(&dn->dn_objset->os_lock);
1364 dnode_setdirty(dn, tx);
1365 }
1366 }
1367
1368 /*
1369 * Try to change the block size for the indicated dnode. This can only
1370 * succeed if there are no blocks allocated or dirty beyond first block
1371 */
1372 int
dnode_set_blksz(dnode_t * dn,uint64_t size,int ibs,dmu_tx_t * tx)1373 dnode_set_blksz(dnode_t *dn, uint64_t size, int ibs, dmu_tx_t *tx)
1374 {
1375 dmu_buf_impl_t *db;
1376 int err;
1377
1378 ASSERT3U(size, <=, spa_maxblocksize(dmu_objset_spa(dn->dn_objset)));
1379 if (size == 0)
1380 size = SPA_MINBLOCKSIZE;
1381 else
1382 size = P2ROUNDUP(size, SPA_MINBLOCKSIZE);
1383
1384 if (ibs == dn->dn_indblkshift)
1385 ibs = 0;
1386
1387 if (size >> SPA_MINBLOCKSHIFT == dn->dn_datablkszsec && ibs == 0)
1388 return (0);
1389
1390 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
1391
1392 /* Check for any allocated blocks beyond the first */
1393 if (dn->dn_maxblkid != 0)
1394 goto fail;
1395
1396 mutex_enter(&dn->dn_dbufs_mtx);
1397 for (db = avl_first(&dn->dn_dbufs); db != NULL;
1398 db = AVL_NEXT(&dn->dn_dbufs, db)) {
1399 if (db->db_blkid != 0 && db->db_blkid != DMU_BONUS_BLKID &&
1400 db->db_blkid != DMU_SPILL_BLKID) {
1401 mutex_exit(&dn->dn_dbufs_mtx);
1402 goto fail;
1403 }
1404 }
1405 mutex_exit(&dn->dn_dbufs_mtx);
1406
1407 if (ibs && dn->dn_nlevels != 1)
1408 goto fail;
1409
1410 /* resize the old block */
1411 err = dbuf_hold_impl(dn, 0, 0, TRUE, FALSE, FTAG, &db);
1412 if (err == 0)
1413 dbuf_new_size(db, size, tx);
1414 else if (err != ENOENT)
1415 goto fail;
1416
1417 dnode_setdblksz(dn, size);
1418 dnode_setdirty(dn, tx);
1419 dn->dn_next_blksz[tx->tx_txg&TXG_MASK] = size;
1420 if (ibs) {
1421 dn->dn_indblkshift = ibs;
1422 dn->dn_next_indblkshift[tx->tx_txg&TXG_MASK] = ibs;
1423 }
1424 /* rele after we have fixed the blocksize in the dnode */
1425 if (db)
1426 dbuf_rele(db, FTAG);
1427
1428 rw_exit(&dn->dn_struct_rwlock);
1429 return (0);
1430
1431 fail:
1432 rw_exit(&dn->dn_struct_rwlock);
1433 return (SET_ERROR(ENOTSUP));
1434 }
1435
1436 /* read-holding callers must not rely on the lock being continuously held */
1437 void
dnode_new_blkid(dnode_t * dn,uint64_t blkid,dmu_tx_t * tx,boolean_t have_read)1438 dnode_new_blkid(dnode_t *dn, uint64_t blkid, dmu_tx_t *tx, boolean_t have_read)
1439 {
1440 uint64_t txgoff = tx->tx_txg & TXG_MASK;
1441 int epbs, new_nlevels;
1442 uint64_t sz;
1443
1444 ASSERT(blkid != DMU_BONUS_BLKID);
1445
1446 ASSERT(have_read ?
1447 RW_READ_HELD(&dn->dn_struct_rwlock) :
1448 RW_WRITE_HELD(&dn->dn_struct_rwlock));
1449
1450 /*
1451 * if we have a read-lock, check to see if we need to do any work
1452 * before upgrading to a write-lock.
1453 */
1454 if (have_read) {
1455 if (blkid <= dn->dn_maxblkid)
1456 return;
1457
1458 if (!rw_tryupgrade(&dn->dn_struct_rwlock)) {
1459 rw_exit(&dn->dn_struct_rwlock);
1460 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
1461 }
1462 }
1463
1464 if (blkid <= dn->dn_maxblkid)
1465 goto out;
1466
1467 dn->dn_maxblkid = blkid;
1468
1469 /*
1470 * Compute the number of levels necessary to support the new maxblkid.
1471 */
1472 new_nlevels = 1;
1473 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT;
1474 for (sz = dn->dn_nblkptr;
1475 sz <= blkid && sz >= dn->dn_nblkptr; sz <<= epbs)
1476 new_nlevels++;
1477
1478 if (new_nlevels > dn->dn_nlevels) {
1479 int old_nlevels = dn->dn_nlevels;
1480 dmu_buf_impl_t *db;
1481 list_t *list;
1482 dbuf_dirty_record_t *new, *dr, *dr_next;
1483
1484 dn->dn_nlevels = new_nlevels;
1485
1486 ASSERT3U(new_nlevels, >, dn->dn_next_nlevels[txgoff]);
1487 dn->dn_next_nlevels[txgoff] = new_nlevels;
1488
1489 /* dirty the left indirects */
1490 db = dbuf_hold_level(dn, old_nlevels, 0, FTAG);
1491 ASSERT(db != NULL);
1492 new = dbuf_dirty(db, tx);
1493 dbuf_rele(db, FTAG);
1494
1495 /* transfer the dirty records to the new indirect */
1496 mutex_enter(&dn->dn_mtx);
1497 mutex_enter(&new->dt.di.dr_mtx);
1498 list = &dn->dn_dirty_records[txgoff];
1499 for (dr = list_head(list); dr; dr = dr_next) {
1500 dr_next = list_next(&dn->dn_dirty_records[txgoff], dr);
1501 if (dr->dr_dbuf->db_level != new_nlevels-1 &&
1502 dr->dr_dbuf->db_blkid != DMU_BONUS_BLKID &&
1503 dr->dr_dbuf->db_blkid != DMU_SPILL_BLKID) {
1504 ASSERT(dr->dr_dbuf->db_level == old_nlevels-1);
1505 list_remove(&dn->dn_dirty_records[txgoff], dr);
1506 list_insert_tail(&new->dt.di.dr_children, dr);
1507 dr->dr_parent = new;
1508 }
1509 }
1510 mutex_exit(&new->dt.di.dr_mtx);
1511 mutex_exit(&dn->dn_mtx);
1512 }
1513
1514 out:
1515 if (have_read)
1516 rw_downgrade(&dn->dn_struct_rwlock);
1517 }
1518
1519 static void
dnode_dirty_l1(dnode_t * dn,uint64_t l1blkid,dmu_tx_t * tx)1520 dnode_dirty_l1(dnode_t *dn, uint64_t l1blkid, dmu_tx_t *tx)
1521 {
1522 dmu_buf_impl_t *db = dbuf_hold_level(dn, 1, l1blkid, FTAG);
1523 if (db != NULL) {
1524 dmu_buf_will_dirty(&db->db, tx);
1525 dbuf_rele(db, FTAG);
1526 }
1527 }
1528
1529 void
dnode_free_range(dnode_t * dn,uint64_t off,uint64_t len,dmu_tx_t * tx)1530 dnode_free_range(dnode_t *dn, uint64_t off, uint64_t len, dmu_tx_t *tx)
1531 {
1532 dmu_buf_impl_t *db;
1533 uint64_t blkoff, blkid, nblks;
1534 int blksz, blkshift, head, tail;
1535 int trunc = FALSE;
1536 int epbs;
1537
1538 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
1539 blksz = dn->dn_datablksz;
1540 blkshift = dn->dn_datablkshift;
1541 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT;
1542
1543 if (len == DMU_OBJECT_END) {
1544 len = UINT64_MAX - off;
1545 trunc = TRUE;
1546 }
1547
1548 /*
1549 * First, block align the region to free:
1550 */
1551 if (ISP2(blksz)) {
1552 head = P2NPHASE(off, blksz);
1553 blkoff = P2PHASE(off, blksz);
1554 if ((off >> blkshift) > dn->dn_maxblkid)
1555 goto out;
1556 } else {
1557 ASSERT(dn->dn_maxblkid == 0);
1558 if (off == 0 && len >= blksz) {
1559 /*
1560 * Freeing the whole block; fast-track this request.
1561 * Note that we won't dirty any indirect blocks,
1562 * which is fine because we will be freeing the entire
1563 * file and thus all indirect blocks will be freed
1564 * by free_children().
1565 */
1566 blkid = 0;
1567 nblks = 1;
1568 goto done;
1569 } else if (off >= blksz) {
1570 /* Freeing past end-of-data */
1571 goto out;
1572 } else {
1573 /* Freeing part of the block. */
1574 head = blksz - off;
1575 ASSERT3U(head, >, 0);
1576 }
1577 blkoff = off;
1578 }
1579 /* zero out any partial block data at the start of the range */
1580 if (head) {
1581 ASSERT3U(blkoff + head, ==, blksz);
1582 if (len < head)
1583 head = len;
1584 if (dbuf_hold_impl(dn, 0, dbuf_whichblock(dn, 0, off),
1585 TRUE, FALSE, FTAG, &db) == 0) {
1586 caddr_t data;
1587
1588 /* don't dirty if it isn't on disk and isn't dirty */
1589 if (db->db_last_dirty ||
1590 (db->db_blkptr && !BP_IS_HOLE(db->db_blkptr))) {
1591 rw_exit(&dn->dn_struct_rwlock);
1592 dmu_buf_will_dirty(&db->db, tx);
1593 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
1594 data = db->db.db_data;
1595 bzero(data + blkoff, head);
1596 }
1597 dbuf_rele(db, FTAG);
1598 }
1599 off += head;
1600 len -= head;
1601 }
1602
1603 /* If the range was less than one block, we're done */
1604 if (len == 0)
1605 goto out;
1606
1607 /* If the remaining range is past end of file, we're done */
1608 if ((off >> blkshift) > dn->dn_maxblkid)
1609 goto out;
1610
1611 ASSERT(ISP2(blksz));
1612 if (trunc)
1613 tail = 0;
1614 else
1615 tail = P2PHASE(len, blksz);
1616
1617 ASSERT0(P2PHASE(off, blksz));
1618 /* zero out any partial block data at the end of the range */
1619 if (tail) {
1620 if (len < tail)
1621 tail = len;
1622 if (dbuf_hold_impl(dn, 0, dbuf_whichblock(dn, 0, off+len),
1623 TRUE, FALSE, FTAG, &db) == 0) {
1624 /* don't dirty if not on disk and not dirty */
1625 if (db->db_last_dirty ||
1626 (db->db_blkptr && !BP_IS_HOLE(db->db_blkptr))) {
1627 rw_exit(&dn->dn_struct_rwlock);
1628 dmu_buf_will_dirty(&db->db, tx);
1629 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
1630 bzero(db->db.db_data, tail);
1631 }
1632 dbuf_rele(db, FTAG);
1633 }
1634 len -= tail;
1635 }
1636
1637 /* If the range did not include a full block, we are done */
1638 if (len == 0)
1639 goto out;
1640
1641 ASSERT(IS_P2ALIGNED(off, blksz));
1642 ASSERT(trunc || IS_P2ALIGNED(len, blksz));
1643 blkid = off >> blkshift;
1644 nblks = len >> blkshift;
1645 if (trunc)
1646 nblks += 1;
1647
1648 /*
1649 * Dirty all the indirect blocks in this range. Note that only
1650 * the first and last indirect blocks can actually be written
1651 * (if they were partially freed) -- they must be dirtied, even if
1652 * they do not exist on disk yet. The interior blocks will
1653 * be freed by free_children(), so they will not actually be written.
1654 * Even though these interior blocks will not be written, we
1655 * dirty them for two reasons:
1656 *
1657 * - It ensures that the indirect blocks remain in memory until
1658 * syncing context. (They have already been prefetched by
1659 * dmu_tx_hold_free(), so we don't have to worry about reading
1660 * them serially here.)
1661 *
1662 * - The dirty space accounting will put pressure on the txg sync
1663 * mechanism to begin syncing, and to delay transactions if there
1664 * is a large amount of freeing. Even though these indirect
1665 * blocks will not be written, we could need to write the same
1666 * amount of space if we copy the freed BPs into deadlists.
1667 */
1668 if (dn->dn_nlevels > 1) {
1669 uint64_t first, last;
1670
1671 first = blkid >> epbs;
1672 dnode_dirty_l1(dn, first, tx);
1673 if (trunc)
1674 last = dn->dn_maxblkid >> epbs;
1675 else
1676 last = (blkid + nblks - 1) >> epbs;
1677 if (last != first)
1678 dnode_dirty_l1(dn, last, tx);
1679
1680 int shift = dn->dn_datablkshift + dn->dn_indblkshift -
1681 SPA_BLKPTRSHIFT;
1682 for (uint64_t i = first + 1; i < last; i++) {
1683 /*
1684 * Set i to the blockid of the next non-hole
1685 * level-1 indirect block at or after i. Note
1686 * that dnode_next_offset() operates in terms of
1687 * level-0-equivalent bytes.
1688 */
1689 uint64_t ibyte = i << shift;
1690 int err = dnode_next_offset(dn, DNODE_FIND_HAVELOCK,
1691 &ibyte, 2, 1, 0);
1692 i = ibyte >> shift;
1693 if (i >= last)
1694 break;
1695
1696 /*
1697 * Normally we should not see an error, either
1698 * from dnode_next_offset() or dbuf_hold_level()
1699 * (except for ESRCH from dnode_next_offset).
1700 * If there is an i/o error, then when we read
1701 * this block in syncing context, it will use
1702 * ZIO_FLAG_MUSTSUCCEED, and thus hang/panic according
1703 * to the "failmode" property. dnode_next_offset()
1704 * doesn't have a flag to indicate MUSTSUCCEED.
1705 */
1706 if (err != 0)
1707 break;
1708
1709 dnode_dirty_l1(dn, i, tx);
1710 }
1711 }
1712
1713 done:
1714 /*
1715 * Add this range to the dnode range list.
1716 * We will finish up this free operation in the syncing phase.
1717 */
1718 mutex_enter(&dn->dn_mtx);
1719 int txgoff = tx->tx_txg & TXG_MASK;
1720 if (dn->dn_free_ranges[txgoff] == NULL) {
1721 dn->dn_free_ranges[txgoff] =
1722 range_tree_create(NULL, NULL, &dn->dn_mtx);
1723 }
1724 range_tree_clear(dn->dn_free_ranges[txgoff], blkid, nblks);
1725 range_tree_add(dn->dn_free_ranges[txgoff], blkid, nblks);
1726 dprintf_dnode(dn, "blkid=%llu nblks=%llu txg=%llu\n",
1727 blkid, nblks, tx->tx_txg);
1728 mutex_exit(&dn->dn_mtx);
1729
1730 dbuf_free_range(dn, blkid, blkid + nblks - 1, tx);
1731 dnode_setdirty(dn, tx);
1732 out:
1733
1734 rw_exit(&dn->dn_struct_rwlock);
1735 }
1736
1737 static boolean_t
dnode_spill_freed(dnode_t * dn)1738 dnode_spill_freed(dnode_t *dn)
1739 {
1740 int i;
1741
1742 mutex_enter(&dn->dn_mtx);
1743 for (i = 0; i < TXG_SIZE; i++) {
1744 if (dn->dn_rm_spillblk[i] == DN_KILL_SPILLBLK)
1745 break;
1746 }
1747 mutex_exit(&dn->dn_mtx);
1748 return (i < TXG_SIZE);
1749 }
1750
1751 /* return TRUE if this blkid was freed in a recent txg, or FALSE if it wasn't */
1752 uint64_t
dnode_block_freed(dnode_t * dn,uint64_t blkid)1753 dnode_block_freed(dnode_t *dn, uint64_t blkid)
1754 {
1755 void *dp = spa_get_dsl(dn->dn_objset->os_spa);
1756 int i;
1757
1758 if (blkid == DMU_BONUS_BLKID)
1759 return (FALSE);
1760
1761 /*
1762 * If we're in the process of opening the pool, dp will not be
1763 * set yet, but there shouldn't be anything dirty.
1764 */
1765 if (dp == NULL)
1766 return (FALSE);
1767
1768 if (dn->dn_free_txg)
1769 return (TRUE);
1770
1771 if (blkid == DMU_SPILL_BLKID)
1772 return (dnode_spill_freed(dn));
1773
1774 mutex_enter(&dn->dn_mtx);
1775 for (i = 0; i < TXG_SIZE; i++) {
1776 if (dn->dn_free_ranges[i] != NULL &&
1777 range_tree_contains(dn->dn_free_ranges[i], blkid, 1))
1778 break;
1779 }
1780 mutex_exit(&dn->dn_mtx);
1781 return (i < TXG_SIZE);
1782 }
1783
1784 /* call from syncing context when we actually write/free space for this dnode */
1785 void
dnode_diduse_space(dnode_t * dn,int64_t delta)1786 dnode_diduse_space(dnode_t *dn, int64_t delta)
1787 {
1788 uint64_t space;
1789 dprintf_dnode(dn, "dn=%p dnp=%p used=%llu delta=%lld\n",
1790 dn, dn->dn_phys,
1791 (u_longlong_t)dn->dn_phys->dn_used,
1792 (longlong_t)delta);
1793
1794 mutex_enter(&dn->dn_mtx);
1795 space = DN_USED_BYTES(dn->dn_phys);
1796 if (delta > 0) {
1797 ASSERT3U(space + delta, >=, space); /* no overflow */
1798 } else {
1799 ASSERT3U(space, >=, -delta); /* no underflow */
1800 }
1801 space += delta;
1802 if (spa_version(dn->dn_objset->os_spa) < SPA_VERSION_DNODE_BYTES) {
1803 ASSERT((dn->dn_phys->dn_flags & DNODE_FLAG_USED_BYTES) == 0);
1804 ASSERT0(P2PHASE(space, 1<<DEV_BSHIFT));
1805 dn->dn_phys->dn_used = space >> DEV_BSHIFT;
1806 } else {
1807 dn->dn_phys->dn_used = space;
1808 dn->dn_phys->dn_flags |= DNODE_FLAG_USED_BYTES;
1809 }
1810 mutex_exit(&dn->dn_mtx);
1811 }
1812
1813 /*
1814 * Call when we think we're going to write/free space in open context to track
1815 * the amount of memory in use by the currently open txg.
1816 */
1817 void
dnode_willuse_space(dnode_t * dn,int64_t space,dmu_tx_t * tx)1818 dnode_willuse_space(dnode_t *dn, int64_t space, dmu_tx_t *tx)
1819 {
1820 objset_t *os = dn->dn_objset;
1821 dsl_dataset_t *ds = os->os_dsl_dataset;
1822 int64_t aspace = spa_get_asize(os->os_spa, space);
1823
1824 if (ds != NULL) {
1825 dsl_dir_willuse_space(ds->ds_dir, aspace, tx);
1826 dsl_pool_dirty_space(dmu_tx_pool(tx), space, tx);
1827 }
1828
1829 dmu_tx_willuse_space(tx, aspace);
1830 }
1831
1832 /*
1833 * Scans a block at the indicated "level" looking for a hole or data,
1834 * depending on 'flags'.
1835 *
1836 * If level > 0, then we are scanning an indirect block looking at its
1837 * pointers. If level == 0, then we are looking at a block of dnodes.
1838 *
1839 * If we don't find what we are looking for in the block, we return ESRCH.
1840 * Otherwise, return with *offset pointing to the beginning (if searching
1841 * forwards) or end (if searching backwards) of the range covered by the
1842 * block pointer we matched on (or dnode).
1843 *
1844 * The basic search algorithm used below by dnode_next_offset() is to
1845 * use this function to search up the block tree (widen the search) until
1846 * we find something (i.e., we don't return ESRCH) and then search back
1847 * down the tree (narrow the search) until we reach our original search
1848 * level.
1849 */
1850 static int
dnode_next_offset_level(dnode_t * dn,int flags,uint64_t * offset,int lvl,uint64_t blkfill,uint64_t txg)1851 dnode_next_offset_level(dnode_t *dn, int flags, uint64_t *offset,
1852 int lvl, uint64_t blkfill, uint64_t txg)
1853 {
1854 dmu_buf_impl_t *db = NULL;
1855 void *data = NULL;
1856 uint64_t epbs = dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT;
1857 uint64_t epb = 1ULL << epbs;
1858 uint64_t minfill, maxfill;
1859 boolean_t hole;
1860 int i, inc, error, span;
1861
1862 dprintf("probing object %llu offset %llx level %d of %u\n",
1863 dn->dn_object, *offset, lvl, dn->dn_phys->dn_nlevels);
1864
1865 hole = ((flags & DNODE_FIND_HOLE) != 0);
1866 inc = (flags & DNODE_FIND_BACKWARDS) ? -1 : 1;
1867 ASSERT(txg == 0 || !hole);
1868
1869 if (lvl == dn->dn_phys->dn_nlevels) {
1870 error = 0;
1871 epb = dn->dn_phys->dn_nblkptr;
1872 data = dn->dn_phys->dn_blkptr;
1873 } else {
1874 uint64_t blkid = dbuf_whichblock(dn, lvl, *offset);
1875 error = dbuf_hold_impl(dn, lvl, blkid, TRUE, FALSE, FTAG, &db);
1876 if (error) {
1877 if (error != ENOENT)
1878 return (error);
1879 if (hole)
1880 return (0);
1881 /*
1882 * This can only happen when we are searching up
1883 * the block tree for data. We don't really need to
1884 * adjust the offset, as we will just end up looking
1885 * at the pointer to this block in its parent, and its
1886 * going to be unallocated, so we will skip over it.
1887 */
1888 return (SET_ERROR(ESRCH));
1889 }
1890 error = dbuf_read(db, NULL, DB_RF_CANFAIL | DB_RF_HAVESTRUCT);
1891 if (error) {
1892 dbuf_rele(db, FTAG);
1893 return (error);
1894 }
1895 data = db->db.db_data;
1896 }
1897
1898
1899 if (db != NULL && txg != 0 && (db->db_blkptr == NULL ||
1900 db->db_blkptr->blk_birth <= txg ||
1901 BP_IS_HOLE(db->db_blkptr))) {
1902 /*
1903 * This can only happen when we are searching up the tree
1904 * and these conditions mean that we need to keep climbing.
1905 */
1906 error = SET_ERROR(ESRCH);
1907 } else if (lvl == 0) {
1908 dnode_phys_t *dnp = data;
1909 span = DNODE_SHIFT;
1910 ASSERT(dn->dn_type == DMU_OT_DNODE);
1911
1912 for (i = (*offset >> span) & (blkfill - 1);
1913 i >= 0 && i < blkfill; i += inc) {
1914 if ((dnp[i].dn_type == DMU_OT_NONE) == hole)
1915 break;
1916 *offset += (1ULL << span) * inc;
1917 }
1918 if (i < 0 || i == blkfill)
1919 error = SET_ERROR(ESRCH);
1920 } else {
1921 blkptr_t *bp = data;
1922 uint64_t start = *offset;
1923 span = (lvl - 1) * epbs + dn->dn_datablkshift;
1924 minfill = 0;
1925 maxfill = blkfill << ((lvl - 1) * epbs);
1926
1927 if (hole)
1928 maxfill--;
1929 else
1930 minfill++;
1931
1932 *offset = *offset >> span;
1933 for (i = BF64_GET(*offset, 0, epbs);
1934 i >= 0 && i < epb; i += inc) {
1935 if (BP_GET_FILL(&bp[i]) >= minfill &&
1936 BP_GET_FILL(&bp[i]) <= maxfill &&
1937 (hole || bp[i].blk_birth > txg))
1938 break;
1939 if (inc > 0 || *offset > 0)
1940 *offset += inc;
1941 }
1942 *offset = *offset << span;
1943 if (inc < 0) {
1944 /* traversing backwards; position offset at the end */
1945 ASSERT3U(*offset, <=, start);
1946 *offset = MIN(*offset + (1ULL << span) - 1, start);
1947 } else if (*offset < start) {
1948 *offset = start;
1949 }
1950 if (i < 0 || i >= epb)
1951 error = SET_ERROR(ESRCH);
1952 }
1953
1954 if (db)
1955 dbuf_rele(db, FTAG);
1956
1957 return (error);
1958 }
1959
1960 /*
1961 * Find the next hole, data, or sparse region at or after *offset.
1962 * The value 'blkfill' tells us how many items we expect to find
1963 * in an L0 data block; this value is 1 for normal objects,
1964 * DNODES_PER_BLOCK for the meta dnode, and some fraction of
1965 * DNODES_PER_BLOCK when searching for sparse regions thereof.
1966 *
1967 * Examples:
1968 *
1969 * dnode_next_offset(dn, flags, offset, 1, 1, 0);
1970 * Finds the next/previous hole/data in a file.
1971 * Used in dmu_offset_next().
1972 *
1973 * dnode_next_offset(mdn, flags, offset, 0, DNODES_PER_BLOCK, txg);
1974 * Finds the next free/allocated dnode an objset's meta-dnode.
1975 * Only finds objects that have new contents since txg (ie.
1976 * bonus buffer changes and content removal are ignored).
1977 * Used in dmu_object_next().
1978 *
1979 * dnode_next_offset(mdn, DNODE_FIND_HOLE, offset, 2, DNODES_PER_BLOCK >> 2, 0);
1980 * Finds the next L2 meta-dnode bp that's at most 1/4 full.
1981 * Used in dmu_object_alloc().
1982 */
1983 int
dnode_next_offset(dnode_t * dn,int flags,uint64_t * offset,int minlvl,uint64_t blkfill,uint64_t txg)1984 dnode_next_offset(dnode_t *dn, int flags, uint64_t *offset,
1985 int minlvl, uint64_t blkfill, uint64_t txg)
1986 {
1987 uint64_t initial_offset = *offset;
1988 int lvl, maxlvl;
1989 int error = 0;
1990
1991 if (!(flags & DNODE_FIND_HAVELOCK))
1992 rw_enter(&dn->dn_struct_rwlock, RW_READER);
1993
1994 if (dn->dn_phys->dn_nlevels == 0) {
1995 error = SET_ERROR(ESRCH);
1996 goto out;
1997 }
1998
1999 if (dn->dn_datablkshift == 0) {
2000 if (*offset < dn->dn_datablksz) {
2001 if (flags & DNODE_FIND_HOLE)
2002 *offset = dn->dn_datablksz;
2003 } else {
2004 error = SET_ERROR(ESRCH);
2005 }
2006 goto out;
2007 }
2008
2009 maxlvl = dn->dn_phys->dn_nlevels;
2010
2011 for (lvl = minlvl; lvl <= maxlvl; lvl++) {
2012 error = dnode_next_offset_level(dn,
2013 flags, offset, lvl, blkfill, txg);
2014 if (error != ESRCH)
2015 break;
2016 }
2017
2018 while (error == 0 && --lvl >= minlvl) {
2019 error = dnode_next_offset_level(dn,
2020 flags, offset, lvl, blkfill, txg);
2021 }
2022
2023 /*
2024 * There's always a "virtual hole" at the end of the object, even
2025 * if all BP's which physically exist are non-holes.
2026 */
2027 if ((flags & DNODE_FIND_HOLE) && error == ESRCH && txg == 0 &&
2028 minlvl == 1 && blkfill == 1 && !(flags & DNODE_FIND_BACKWARDS)) {
2029 error = 0;
2030 }
2031
2032 if (error == 0 && (flags & DNODE_FIND_BACKWARDS ?
2033 initial_offset < *offset : initial_offset > *offset))
2034 error = SET_ERROR(ESRCH);
2035 out:
2036 if (!(flags & DNODE_FIND_HAVELOCK))
2037 rw_exit(&dn->dn_struct_rwlock);
2038
2039 return (error);
2040 }
2041