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, 2014 by Delphix. All rights reserved.
24 */
25
26 #include <sys/zfs_context.h>
27 #include <sys/dbuf.h>
28 #include <sys/dnode.h>
29 #include <sys/dmu.h>
30 #include <sys/dmu_impl.h>
31 #include <sys/dmu_tx.h>
32 #include <sys/dmu_objset.h>
33 #include <sys/dsl_dir.h>
34 #include <sys/dsl_dataset.h>
35 #include <sys/spa.h>
36 #include <sys/zio.h>
37 #include <sys/dmu_zfetch.h>
38 #include <sys/range_tree.h>
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 #ifdef sun
61 static kmem_cbrc_t dnode_move(void *, void *, size_t, void *);
62 #endif
63
64 static int
dbuf_compare(const void * x1,const void * x2)65 dbuf_compare(const void *x1, const void *x2)
66 {
67 const dmu_buf_impl_t *d1 = x1;
68 const dmu_buf_impl_t *d2 = x2;
69
70 if (d1->db_level < d2->db_level) {
71 return (-1);
72 }
73 if (d1->db_level > d2->db_level) {
74 return (1);
75 }
76
77 if (d1->db_blkid < d2->db_blkid) {
78 return (-1);
79 }
80 if (d1->db_blkid > d2->db_blkid) {
81 return (1);
82 }
83
84 if (d1->db_state == DB_SEARCH) {
85 ASSERT3S(d2->db_state, !=, DB_SEARCH);
86 return (-1);
87 } else if (d2->db_state == DB_SEARCH) {
88 ASSERT3S(d1->db_state, !=, DB_SEARCH);
89 return (1);
90 }
91
92 if ((uintptr_t)d1 < (uintptr_t)d2) {
93 return (-1);
94 }
95 if ((uintptr_t)d1 > (uintptr_t)d2) {
96 return (1);
97 }
98 return (0);
99 }
100
101 /* ARGSUSED */
102 static int
dnode_cons(void * arg,void * unused,int kmflag)103 dnode_cons(void *arg, void *unused, int kmflag)
104 {
105 dnode_t *dn = arg;
106 int i;
107
108 rw_init(&dn->dn_struct_rwlock, NULL, RW_DEFAULT, NULL);
109 mutex_init(&dn->dn_mtx, NULL, MUTEX_DEFAULT, NULL);
110 mutex_init(&dn->dn_dbufs_mtx, NULL, MUTEX_DEFAULT, NULL);
111 cv_init(&dn->dn_notxholds, NULL, CV_DEFAULT, NULL);
112
113 /*
114 * Every dbuf has a reference, and dropping a tracked reference is
115 * O(number of references), so don't track dn_holds.
116 */
117 refcount_create_untracked(&dn->dn_holds);
118 refcount_create(&dn->dn_tx_holds);
119 list_link_init(&dn->dn_link);
120
121 bzero(&dn->dn_next_nblkptr[0], sizeof (dn->dn_next_nblkptr));
122 bzero(&dn->dn_next_nlevels[0], sizeof (dn->dn_next_nlevels));
123 bzero(&dn->dn_next_indblkshift[0], sizeof (dn->dn_next_indblkshift));
124 bzero(&dn->dn_next_bonustype[0], sizeof (dn->dn_next_bonustype));
125 bzero(&dn->dn_rm_spillblk[0], sizeof (dn->dn_rm_spillblk));
126 bzero(&dn->dn_next_bonuslen[0], sizeof (dn->dn_next_bonuslen));
127 bzero(&dn->dn_next_blksz[0], sizeof (dn->dn_next_blksz));
128
129 for (i = 0; i < TXG_SIZE; i++) {
130 list_link_init(&dn->dn_dirty_link[i]);
131 dn->dn_free_ranges[i] = NULL;
132 list_create(&dn->dn_dirty_records[i],
133 sizeof (dbuf_dirty_record_t),
134 offsetof(dbuf_dirty_record_t, dr_dirty_node));
135 }
136
137 dn->dn_allocated_txg = 0;
138 dn->dn_free_txg = 0;
139 dn->dn_assigned_txg = 0;
140 dn->dn_dirtyctx = 0;
141 dn->dn_dirtyctx_firstset = NULL;
142 dn->dn_bonus = NULL;
143 dn->dn_have_spill = B_FALSE;
144 dn->dn_zio = NULL;
145 dn->dn_oldused = 0;
146 dn->dn_oldflags = 0;
147 dn->dn_olduid = 0;
148 dn->dn_oldgid = 0;
149 dn->dn_newuid = 0;
150 dn->dn_newgid = 0;
151 dn->dn_id_flags = 0;
152
153 dn->dn_dbufs_count = 0;
154 dn->dn_unlisted_l0_blkid = 0;
155 avl_create(&dn->dn_dbufs, dbuf_compare, sizeof (dmu_buf_impl_t),
156 offsetof(dmu_buf_impl_t, db_link));
157
158 dn->dn_moved = 0;
159 POINTER_INVALIDATE(&dn->dn_objset);
160 return (0);
161 }
162
163 /* ARGSUSED */
164 static void
dnode_dest(void * arg,void * unused)165 dnode_dest(void *arg, void *unused)
166 {
167 int i;
168 dnode_t *dn = arg;
169
170 rw_destroy(&dn->dn_struct_rwlock);
171 mutex_destroy(&dn->dn_mtx);
172 mutex_destroy(&dn->dn_dbufs_mtx);
173 cv_destroy(&dn->dn_notxholds);
174 refcount_destroy(&dn->dn_holds);
175 refcount_destroy(&dn->dn_tx_holds);
176 ASSERT(!list_link_active(&dn->dn_link));
177
178 for (i = 0; i < TXG_SIZE; i++) {
179 ASSERT(!list_link_active(&dn->dn_dirty_link[i]));
180 ASSERT3P(dn->dn_free_ranges[i], ==, NULL);
181 list_destroy(&dn->dn_dirty_records[i]);
182 ASSERT0(dn->dn_next_nblkptr[i]);
183 ASSERT0(dn->dn_next_nlevels[i]);
184 ASSERT0(dn->dn_next_indblkshift[i]);
185 ASSERT0(dn->dn_next_bonustype[i]);
186 ASSERT0(dn->dn_rm_spillblk[i]);
187 ASSERT0(dn->dn_next_bonuslen[i]);
188 ASSERT0(dn->dn_next_blksz[i]);
189 }
190
191 ASSERT0(dn->dn_allocated_txg);
192 ASSERT0(dn->dn_free_txg);
193 ASSERT0(dn->dn_assigned_txg);
194 ASSERT0(dn->dn_dirtyctx);
195 ASSERT3P(dn->dn_dirtyctx_firstset, ==, NULL);
196 ASSERT3P(dn->dn_bonus, ==, NULL);
197 ASSERT(!dn->dn_have_spill);
198 ASSERT3P(dn->dn_zio, ==, NULL);
199 ASSERT0(dn->dn_oldused);
200 ASSERT0(dn->dn_oldflags);
201 ASSERT0(dn->dn_olduid);
202 ASSERT0(dn->dn_oldgid);
203 ASSERT0(dn->dn_newuid);
204 ASSERT0(dn->dn_newgid);
205 ASSERT0(dn->dn_id_flags);
206
207 ASSERT0(dn->dn_dbufs_count);
208 ASSERT0(dn->dn_unlisted_l0_blkid);
209 avl_destroy(&dn->dn_dbufs);
210 }
211
212 void
dnode_init(void)213 dnode_init(void)
214 {
215 ASSERT(dnode_cache == NULL);
216 dnode_cache = kmem_cache_create("dnode_t",
217 sizeof (dnode_t),
218 0, dnode_cons, dnode_dest, NULL, NULL, NULL, 0);
219 kmem_cache_set_move(dnode_cache, dnode_move);
220 }
221
222 void
dnode_fini(void)223 dnode_fini(void)
224 {
225 kmem_cache_destroy(dnode_cache);
226 dnode_cache = NULL;
227 }
228
229
230 #ifdef ZFS_DEBUG
231 void
dnode_verify(dnode_t * dn)232 dnode_verify(dnode_t *dn)
233 {
234 int drop_struct_lock = FALSE;
235
236 ASSERT(dn->dn_phys);
237 ASSERT(dn->dn_objset);
238 ASSERT(dn->dn_handle->dnh_dnode == dn);
239
240 ASSERT(DMU_OT_IS_VALID(dn->dn_phys->dn_type));
241
242 if (!(zfs_flags & ZFS_DEBUG_DNODE_VERIFY))
243 return;
244
245 if (!RW_WRITE_HELD(&dn->dn_struct_rwlock)) {
246 rw_enter(&dn->dn_struct_rwlock, RW_READER);
247 drop_struct_lock = TRUE;
248 }
249 if (dn->dn_phys->dn_type != DMU_OT_NONE || dn->dn_allocated_txg != 0) {
250 int i;
251 ASSERT3U(dn->dn_indblkshift, >=, 0);
252 ASSERT3U(dn->dn_indblkshift, <=, SPA_MAXBLOCKSHIFT);
253 if (dn->dn_datablkshift) {
254 ASSERT3U(dn->dn_datablkshift, >=, SPA_MINBLOCKSHIFT);
255 ASSERT3U(dn->dn_datablkshift, <=, SPA_MAXBLOCKSHIFT);
256 ASSERT3U(1<<dn->dn_datablkshift, ==, dn->dn_datablksz);
257 }
258 ASSERT3U(dn->dn_nlevels, <=, 30);
259 ASSERT(DMU_OT_IS_VALID(dn->dn_type));
260 ASSERT3U(dn->dn_nblkptr, >=, 1);
261 ASSERT3U(dn->dn_nblkptr, <=, DN_MAX_NBLKPTR);
262 ASSERT3U(dn->dn_bonuslen, <=, DN_MAX_BONUSLEN);
263 ASSERT3U(dn->dn_datablksz, ==,
264 dn->dn_datablkszsec << SPA_MINBLOCKSHIFT);
265 ASSERT3U(ISP2(dn->dn_datablksz), ==, dn->dn_datablkshift != 0);
266 ASSERT3U((dn->dn_nblkptr - 1) * sizeof (blkptr_t) +
267 dn->dn_bonuslen, <=, DN_MAX_BONUSLEN);
268 for (i = 0; i < TXG_SIZE; i++) {
269 ASSERT3U(dn->dn_next_nlevels[i], <=, dn->dn_nlevels);
270 }
271 }
272 if (dn->dn_phys->dn_type != DMU_OT_NONE)
273 ASSERT3U(dn->dn_phys->dn_nlevels, <=, dn->dn_nlevels);
274 ASSERT(DMU_OBJECT_IS_SPECIAL(dn->dn_object) || dn->dn_dbuf != NULL);
275 if (dn->dn_dbuf != NULL) {
276 ASSERT3P(dn->dn_phys, ==,
277 (dnode_phys_t *)dn->dn_dbuf->db.db_data +
278 (dn->dn_object % (dn->dn_dbuf->db.db_size >> DNODE_SHIFT)));
279 }
280 if (drop_struct_lock)
281 rw_exit(&dn->dn_struct_rwlock);
282 }
283 #endif
284
285 void
dnode_byteswap(dnode_phys_t * dnp)286 dnode_byteswap(dnode_phys_t *dnp)
287 {
288 uint64_t *buf64 = (void*)&dnp->dn_blkptr;
289 int i;
290
291 if (dnp->dn_type == DMU_OT_NONE) {
292 bzero(dnp, sizeof (dnode_phys_t));
293 return;
294 }
295
296 dnp->dn_datablkszsec = BSWAP_16(dnp->dn_datablkszsec);
297 dnp->dn_bonuslen = BSWAP_16(dnp->dn_bonuslen);
298 dnp->dn_maxblkid = BSWAP_64(dnp->dn_maxblkid);
299 dnp->dn_used = BSWAP_64(dnp->dn_used);
300
301 /*
302 * dn_nblkptr is only one byte, so it's OK to read it in either
303 * byte order. We can't read dn_bouslen.
304 */
305 ASSERT(dnp->dn_indblkshift <= SPA_MAXBLOCKSHIFT);
306 ASSERT(dnp->dn_nblkptr <= DN_MAX_NBLKPTR);
307 for (i = 0; i < dnp->dn_nblkptr * sizeof (blkptr_t)/8; i++)
308 buf64[i] = BSWAP_64(buf64[i]);
309
310 /*
311 * OK to check dn_bonuslen for zero, because it won't matter if
312 * we have the wrong byte order. This is necessary because the
313 * dnode dnode is smaller than a regular dnode.
314 */
315 if (dnp->dn_bonuslen != 0) {
316 /*
317 * Note that the bonus length calculated here may be
318 * longer than the actual bonus buffer. This is because
319 * we always put the bonus buffer after the last block
320 * pointer (instead of packing it against the end of the
321 * dnode buffer).
322 */
323 int off = (dnp->dn_nblkptr-1) * sizeof (blkptr_t);
324 size_t len = DN_MAX_BONUSLEN - off;
325 ASSERT(DMU_OT_IS_VALID(dnp->dn_bonustype));
326 dmu_object_byteswap_t byteswap =
327 DMU_OT_BYTESWAP(dnp->dn_bonustype);
328 dmu_ot_byteswap[byteswap].ob_func(dnp->dn_bonus + off, len);
329 }
330
331 /* Swap SPILL block if we have one */
332 if (dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR)
333 byteswap_uint64_array(&dnp->dn_spill, sizeof (blkptr_t));
334
335 }
336
337 void
dnode_buf_byteswap(void * vbuf,size_t size)338 dnode_buf_byteswap(void *vbuf, size_t size)
339 {
340 dnode_phys_t *buf = vbuf;
341 int i;
342
343 ASSERT3U(sizeof (dnode_phys_t), ==, (1<<DNODE_SHIFT));
344 ASSERT((size & (sizeof (dnode_phys_t)-1)) == 0);
345
346 size >>= DNODE_SHIFT;
347 for (i = 0; i < size; i++) {
348 dnode_byteswap(buf);
349 buf++;
350 }
351 }
352
353 void
dnode_setbonuslen(dnode_t * dn,int newsize,dmu_tx_t * tx)354 dnode_setbonuslen(dnode_t *dn, int newsize, dmu_tx_t *tx)
355 {
356 ASSERT3U(refcount_count(&dn->dn_holds), >=, 1);
357
358 dnode_setdirty(dn, tx);
359 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
360 ASSERT3U(newsize, <=, DN_MAX_BONUSLEN -
361 (dn->dn_nblkptr-1) * sizeof (blkptr_t));
362 dn->dn_bonuslen = newsize;
363 if (newsize == 0)
364 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = DN_ZERO_BONUSLEN;
365 else
366 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = dn->dn_bonuslen;
367 rw_exit(&dn->dn_struct_rwlock);
368 }
369
370 void
dnode_setbonus_type(dnode_t * dn,dmu_object_type_t newtype,dmu_tx_t * tx)371 dnode_setbonus_type(dnode_t *dn, dmu_object_type_t newtype, dmu_tx_t *tx)
372 {
373 ASSERT3U(refcount_count(&dn->dn_holds), >=, 1);
374 dnode_setdirty(dn, tx);
375 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
376 dn->dn_bonustype = newtype;
377 dn->dn_next_bonustype[tx->tx_txg & TXG_MASK] = dn->dn_bonustype;
378 rw_exit(&dn->dn_struct_rwlock);
379 }
380
381 void
dnode_rm_spill(dnode_t * dn,dmu_tx_t * tx)382 dnode_rm_spill(dnode_t *dn, dmu_tx_t *tx)
383 {
384 ASSERT3U(refcount_count(&dn->dn_holds), >=, 1);
385 ASSERT(RW_WRITE_HELD(&dn->dn_struct_rwlock));
386 dnode_setdirty(dn, tx);
387 dn->dn_rm_spillblk[tx->tx_txg&TXG_MASK] = DN_KILL_SPILLBLK;
388 dn->dn_have_spill = B_FALSE;
389 }
390
391 static void
dnode_setdblksz(dnode_t * dn,int size)392 dnode_setdblksz(dnode_t *dn, int size)
393 {
394 ASSERT0(P2PHASE(size, SPA_MINBLOCKSIZE));
395 ASSERT3U(size, <=, SPA_MAXBLOCKSIZE);
396 ASSERT3U(size, >=, SPA_MINBLOCKSIZE);
397 ASSERT3U(size >> SPA_MINBLOCKSHIFT, <,
398 1<<(sizeof (dn->dn_phys->dn_datablkszsec) * 8));
399 dn->dn_datablksz = size;
400 dn->dn_datablkszsec = size >> SPA_MINBLOCKSHIFT;
401 dn->dn_datablkshift = ISP2(size) ? highbit64(size - 1) : 0;
402 }
403
404 static dnode_t *
dnode_create(objset_t * os,dnode_phys_t * dnp,dmu_buf_impl_t * db,uint64_t object,dnode_handle_t * dnh)405 dnode_create(objset_t *os, dnode_phys_t *dnp, dmu_buf_impl_t *db,
406 uint64_t object, dnode_handle_t *dnh)
407 {
408 dnode_t *dn = kmem_cache_alloc(dnode_cache, KM_SLEEP);
409
410 ASSERT(!POINTER_IS_VALID(dn->dn_objset));
411 dn->dn_moved = 0;
412
413 /*
414 * Defer setting dn_objset until the dnode is ready to be a candidate
415 * for the dnode_move() callback.
416 */
417 dn->dn_object = object;
418 dn->dn_dbuf = db;
419 dn->dn_handle = dnh;
420 dn->dn_phys = dnp;
421
422 if (dnp->dn_datablkszsec) {
423 dnode_setdblksz(dn, dnp->dn_datablkszsec << SPA_MINBLOCKSHIFT);
424 } else {
425 dn->dn_datablksz = 0;
426 dn->dn_datablkszsec = 0;
427 dn->dn_datablkshift = 0;
428 }
429 dn->dn_indblkshift = dnp->dn_indblkshift;
430 dn->dn_nlevels = dnp->dn_nlevels;
431 dn->dn_type = dnp->dn_type;
432 dn->dn_nblkptr = dnp->dn_nblkptr;
433 dn->dn_checksum = dnp->dn_checksum;
434 dn->dn_compress = dnp->dn_compress;
435 dn->dn_bonustype = dnp->dn_bonustype;
436 dn->dn_bonuslen = dnp->dn_bonuslen;
437 dn->dn_maxblkid = dnp->dn_maxblkid;
438 dn->dn_have_spill = ((dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) != 0);
439 dn->dn_id_flags = 0;
440
441 dmu_zfetch_init(&dn->dn_zfetch, dn);
442
443 ASSERT(DMU_OT_IS_VALID(dn->dn_phys->dn_type));
444
445 mutex_enter(&os->os_lock);
446 list_insert_head(&os->os_dnodes, dn);
447 membar_producer();
448 /*
449 * Everything else must be valid before assigning dn_objset makes the
450 * dnode eligible for dnode_move().
451 */
452 dn->dn_objset = os;
453 mutex_exit(&os->os_lock);
454
455 arc_space_consume(sizeof (dnode_t), ARC_SPACE_OTHER);
456 return (dn);
457 }
458
459 /*
460 * Caller must be holding the dnode handle, which is released upon return.
461 */
462 static void
dnode_destroy(dnode_t * dn)463 dnode_destroy(dnode_t *dn)
464 {
465 objset_t *os = dn->dn_objset;
466
467 ASSERT((dn->dn_id_flags & DN_ID_NEW_EXIST) == 0);
468
469 mutex_enter(&os->os_lock);
470 POINTER_INVALIDATE(&dn->dn_objset);
471 list_remove(&os->os_dnodes, dn);
472 mutex_exit(&os->os_lock);
473
474 /* the dnode can no longer move, so we can release the handle */
475 zrl_remove(&dn->dn_handle->dnh_zrlock);
476
477 dn->dn_allocated_txg = 0;
478 dn->dn_free_txg = 0;
479 dn->dn_assigned_txg = 0;
480
481 dn->dn_dirtyctx = 0;
482 if (dn->dn_dirtyctx_firstset != NULL) {
483 kmem_free(dn->dn_dirtyctx_firstset, 1);
484 dn->dn_dirtyctx_firstset = NULL;
485 }
486 if (dn->dn_bonus != NULL) {
487 mutex_enter(&dn->dn_bonus->db_mtx);
488 dbuf_evict(dn->dn_bonus);
489 dn->dn_bonus = NULL;
490 }
491 dn->dn_zio = NULL;
492
493 dn->dn_have_spill = B_FALSE;
494 dn->dn_oldused = 0;
495 dn->dn_oldflags = 0;
496 dn->dn_olduid = 0;
497 dn->dn_oldgid = 0;
498 dn->dn_newuid = 0;
499 dn->dn_newgid = 0;
500 dn->dn_id_flags = 0;
501 dn->dn_unlisted_l0_blkid = 0;
502
503 dmu_zfetch_rele(&dn->dn_zfetch);
504 kmem_cache_free(dnode_cache, dn);
505 arc_space_return(sizeof (dnode_t), ARC_SPACE_OTHER);
506 }
507
508 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)509 dnode_allocate(dnode_t *dn, dmu_object_type_t ot, int blocksize, int ibs,
510 dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx)
511 {
512 int i;
513
514 ASSERT3U(blocksize, <=,
515 spa_maxblocksize(dmu_objset_spa(dn->dn_objset)));
516 if (blocksize == 0)
517 blocksize = 1 << zfs_default_bs;
518 else
519 blocksize = P2ROUNDUP(blocksize, SPA_MINBLOCKSIZE);
520
521 if (ibs == 0)
522 ibs = zfs_default_ibs;
523
524 ibs = MIN(MAX(ibs, DN_MIN_INDBLKSHIFT), DN_MAX_INDBLKSHIFT);
525
526 dprintf("os=%p obj=%llu txg=%llu blocksize=%d ibs=%d\n", dn->dn_objset,
527 dn->dn_object, tx->tx_txg, blocksize, ibs);
528
529 ASSERT(dn->dn_type == DMU_OT_NONE);
530 ASSERT(bcmp(dn->dn_phys, &dnode_phys_zero, sizeof (dnode_phys_t)) == 0);
531 ASSERT(dn->dn_phys->dn_type == DMU_OT_NONE);
532 ASSERT(ot != DMU_OT_NONE);
533 ASSERT(DMU_OT_IS_VALID(ot));
534 ASSERT((bonustype == DMU_OT_NONE && bonuslen == 0) ||
535 (bonustype == DMU_OT_SA && bonuslen == 0) ||
536 (bonustype != DMU_OT_NONE && bonuslen != 0));
537 ASSERT(DMU_OT_IS_VALID(bonustype));
538 ASSERT3U(bonuslen, <=, DN_MAX_BONUSLEN);
539 ASSERT(dn->dn_type == DMU_OT_NONE);
540 ASSERT0(dn->dn_maxblkid);
541 ASSERT0(dn->dn_allocated_txg);
542 ASSERT0(dn->dn_assigned_txg);
543 ASSERT(refcount_is_zero(&dn->dn_tx_holds));
544 ASSERT3U(refcount_count(&dn->dn_holds), <=, 1);
545 ASSERT(avl_is_empty(&dn->dn_dbufs));
546
547 for (i = 0; i < TXG_SIZE; i++) {
548 ASSERT0(dn->dn_next_nblkptr[i]);
549 ASSERT0(dn->dn_next_nlevels[i]);
550 ASSERT0(dn->dn_next_indblkshift[i]);
551 ASSERT0(dn->dn_next_bonuslen[i]);
552 ASSERT0(dn->dn_next_bonustype[i]);
553 ASSERT0(dn->dn_rm_spillblk[i]);
554 ASSERT0(dn->dn_next_blksz[i]);
555 ASSERT(!list_link_active(&dn->dn_dirty_link[i]));
556 ASSERT3P(list_head(&dn->dn_dirty_records[i]), ==, NULL);
557 ASSERT3P(dn->dn_free_ranges[i], ==, NULL);
558 }
559
560 dn->dn_type = ot;
561 dnode_setdblksz(dn, blocksize);
562 dn->dn_indblkshift = ibs;
563 dn->dn_nlevels = 1;
564 if (bonustype == DMU_OT_SA) /* Maximize bonus space for SA */
565 dn->dn_nblkptr = 1;
566 else
567 dn->dn_nblkptr = 1 +
568 ((DN_MAX_BONUSLEN - bonuslen) >> SPA_BLKPTRSHIFT);
569 dn->dn_bonustype = bonustype;
570 dn->dn_bonuslen = bonuslen;
571 dn->dn_checksum = ZIO_CHECKSUM_INHERIT;
572 dn->dn_compress = ZIO_COMPRESS_INHERIT;
573 dn->dn_dirtyctx = 0;
574
575 dn->dn_free_txg = 0;
576 if (dn->dn_dirtyctx_firstset) {
577 kmem_free(dn->dn_dirtyctx_firstset, 1);
578 dn->dn_dirtyctx_firstset = NULL;
579 }
580
581 dn->dn_allocated_txg = tx->tx_txg;
582 dn->dn_id_flags = 0;
583
584 dnode_setdirty(dn, tx);
585 dn->dn_next_indblkshift[tx->tx_txg & TXG_MASK] = ibs;
586 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = dn->dn_bonuslen;
587 dn->dn_next_bonustype[tx->tx_txg & TXG_MASK] = dn->dn_bonustype;
588 dn->dn_next_blksz[tx->tx_txg & TXG_MASK] = dn->dn_datablksz;
589 }
590
591 void
dnode_reallocate(dnode_t * dn,dmu_object_type_t ot,int blocksize,dmu_object_type_t bonustype,int bonuslen,dmu_tx_t * tx)592 dnode_reallocate(dnode_t *dn, dmu_object_type_t ot, int blocksize,
593 dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx)
594 {
595 int nblkptr;
596
597 ASSERT3U(blocksize, >=, SPA_MINBLOCKSIZE);
598 ASSERT3U(blocksize, <=,
599 spa_maxblocksize(dmu_objset_spa(dn->dn_objset)));
600 ASSERT0(blocksize % SPA_MINBLOCKSIZE);
601 ASSERT(dn->dn_object != DMU_META_DNODE_OBJECT || dmu_tx_private_ok(tx));
602 ASSERT(tx->tx_txg != 0);
603 ASSERT((bonustype == DMU_OT_NONE && bonuslen == 0) ||
604 (bonustype != DMU_OT_NONE && bonuslen != 0) ||
605 (bonustype == DMU_OT_SA && bonuslen == 0));
606 ASSERT(DMU_OT_IS_VALID(bonustype));
607 ASSERT3U(bonuslen, <=, DN_MAX_BONUSLEN);
608
609 /* clean up any unreferenced dbufs */
610 dnode_evict_dbufs(dn);
611
612 dn->dn_id_flags = 0;
613
614 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
615 dnode_setdirty(dn, tx);
616 if (dn->dn_datablksz != blocksize) {
617 /* change blocksize */
618 ASSERT(dn->dn_maxblkid == 0 &&
619 (BP_IS_HOLE(&dn->dn_phys->dn_blkptr[0]) ||
620 dnode_block_freed(dn, 0)));
621 dnode_setdblksz(dn, blocksize);
622 dn->dn_next_blksz[tx->tx_txg&TXG_MASK] = blocksize;
623 }
624 if (dn->dn_bonuslen != bonuslen)
625 dn->dn_next_bonuslen[tx->tx_txg&TXG_MASK] = bonuslen;
626
627 if (bonustype == DMU_OT_SA) /* Maximize bonus space for SA */
628 nblkptr = 1;
629 else
630 nblkptr = 1 + ((DN_MAX_BONUSLEN - bonuslen) >> SPA_BLKPTRSHIFT);
631 if (dn->dn_bonustype != bonustype)
632 dn->dn_next_bonustype[tx->tx_txg&TXG_MASK] = bonustype;
633 if (dn->dn_nblkptr != nblkptr)
634 dn->dn_next_nblkptr[tx->tx_txg&TXG_MASK] = nblkptr;
635 if (dn->dn_phys->dn_flags & DNODE_FLAG_SPILL_BLKPTR) {
636 dbuf_rm_spill(dn, tx);
637 dnode_rm_spill(dn, tx);
638 }
639 rw_exit(&dn->dn_struct_rwlock);
640
641 /* change type */
642 dn->dn_type = ot;
643
644 /* change bonus size and type */
645 mutex_enter(&dn->dn_mtx);
646 dn->dn_bonustype = bonustype;
647 dn->dn_bonuslen = bonuslen;
648 dn->dn_nblkptr = nblkptr;
649 dn->dn_checksum = ZIO_CHECKSUM_INHERIT;
650 dn->dn_compress = ZIO_COMPRESS_INHERIT;
651 ASSERT3U(dn->dn_nblkptr, <=, DN_MAX_NBLKPTR);
652
653 /* fix up the bonus db_size */
654 if (dn->dn_bonus) {
655 dn->dn_bonus->db.db_size =
656 DN_MAX_BONUSLEN - (dn->dn_nblkptr-1) * sizeof (blkptr_t);
657 ASSERT(dn->dn_bonuslen <= dn->dn_bonus->db.db_size);
658 }
659
660 dn->dn_allocated_txg = tx->tx_txg;
661 mutex_exit(&dn->dn_mtx);
662 }
663
664 #ifdef DNODE_STATS
665 static struct {
666 uint64_t dms_dnode_invalid;
667 uint64_t dms_dnode_recheck1;
668 uint64_t dms_dnode_recheck2;
669 uint64_t dms_dnode_special;
670 uint64_t dms_dnode_handle;
671 uint64_t dms_dnode_rwlock;
672 uint64_t dms_dnode_active;
673 } dnode_move_stats;
674 #endif /* DNODE_STATS */
675
676 static void
dnode_move_impl(dnode_t * odn,dnode_t * ndn)677 dnode_move_impl(dnode_t *odn, dnode_t *ndn)
678 {
679 int i;
680
681 ASSERT(!RW_LOCK_HELD(&odn->dn_struct_rwlock));
682 ASSERT(MUTEX_NOT_HELD(&odn->dn_mtx));
683 ASSERT(MUTEX_NOT_HELD(&odn->dn_dbufs_mtx));
684 ASSERT(!RW_LOCK_HELD(&odn->dn_zfetch.zf_rwlock));
685
686 /* Copy fields. */
687 ndn->dn_objset = odn->dn_objset;
688 ndn->dn_object = odn->dn_object;
689 ndn->dn_dbuf = odn->dn_dbuf;
690 ndn->dn_handle = odn->dn_handle;
691 ndn->dn_phys = odn->dn_phys;
692 ndn->dn_type = odn->dn_type;
693 ndn->dn_bonuslen = odn->dn_bonuslen;
694 ndn->dn_bonustype = odn->dn_bonustype;
695 ndn->dn_nblkptr = odn->dn_nblkptr;
696 ndn->dn_checksum = odn->dn_checksum;
697 ndn->dn_compress = odn->dn_compress;
698 ndn->dn_nlevels = odn->dn_nlevels;
699 ndn->dn_indblkshift = odn->dn_indblkshift;
700 ndn->dn_datablkshift = odn->dn_datablkshift;
701 ndn->dn_datablkszsec = odn->dn_datablkszsec;
702 ndn->dn_datablksz = odn->dn_datablksz;
703 ndn->dn_maxblkid = odn->dn_maxblkid;
704 bcopy(&odn->dn_next_nblkptr[0], &ndn->dn_next_nblkptr[0],
705 sizeof (odn->dn_next_nblkptr));
706 bcopy(&odn->dn_next_nlevels[0], &ndn->dn_next_nlevels[0],
707 sizeof (odn->dn_next_nlevels));
708 bcopy(&odn->dn_next_indblkshift[0], &ndn->dn_next_indblkshift[0],
709 sizeof (odn->dn_next_indblkshift));
710 bcopy(&odn->dn_next_bonustype[0], &ndn->dn_next_bonustype[0],
711 sizeof (odn->dn_next_bonustype));
712 bcopy(&odn->dn_rm_spillblk[0], &ndn->dn_rm_spillblk[0],
713 sizeof (odn->dn_rm_spillblk));
714 bcopy(&odn->dn_next_bonuslen[0], &ndn->dn_next_bonuslen[0],
715 sizeof (odn->dn_next_bonuslen));
716 bcopy(&odn->dn_next_blksz[0], &ndn->dn_next_blksz[0],
717 sizeof (odn->dn_next_blksz));
718 for (i = 0; i < TXG_SIZE; i++) {
719 list_move_tail(&ndn->dn_dirty_records[i],
720 &odn->dn_dirty_records[i]);
721 }
722 bcopy(&odn->dn_free_ranges[0], &ndn->dn_free_ranges[0],
723 sizeof (odn->dn_free_ranges));
724 ndn->dn_allocated_txg = odn->dn_allocated_txg;
725 ndn->dn_free_txg = odn->dn_free_txg;
726 ndn->dn_assigned_txg = odn->dn_assigned_txg;
727 ndn->dn_dirtyctx = odn->dn_dirtyctx;
728 ndn->dn_dirtyctx_firstset = odn->dn_dirtyctx_firstset;
729 ASSERT(refcount_count(&odn->dn_tx_holds) == 0);
730 refcount_transfer(&ndn->dn_holds, &odn->dn_holds);
731 ASSERT(avl_is_empty(&ndn->dn_dbufs));
732 avl_swap(&ndn->dn_dbufs, &odn->dn_dbufs);
733 ndn->dn_dbufs_count = odn->dn_dbufs_count;
734 ndn->dn_unlisted_l0_blkid = odn->dn_unlisted_l0_blkid;
735 ndn->dn_bonus = odn->dn_bonus;
736 ndn->dn_have_spill = odn->dn_have_spill;
737 ndn->dn_zio = odn->dn_zio;
738 ndn->dn_oldused = odn->dn_oldused;
739 ndn->dn_oldflags = odn->dn_oldflags;
740 ndn->dn_olduid = odn->dn_olduid;
741 ndn->dn_oldgid = odn->dn_oldgid;
742 ndn->dn_newuid = odn->dn_newuid;
743 ndn->dn_newgid = odn->dn_newgid;
744 ndn->dn_id_flags = odn->dn_id_flags;
745 dmu_zfetch_init(&ndn->dn_zfetch, NULL);
746 list_move_tail(&ndn->dn_zfetch.zf_stream, &odn->dn_zfetch.zf_stream);
747 ndn->dn_zfetch.zf_dnode = odn->dn_zfetch.zf_dnode;
748 ndn->dn_zfetch.zf_stream_cnt = odn->dn_zfetch.zf_stream_cnt;
749 ndn->dn_zfetch.zf_alloc_fail = odn->dn_zfetch.zf_alloc_fail;
750
751 /*
752 * Update back pointers. Updating the handle fixes the back pointer of
753 * every descendant dbuf as well as the bonus dbuf.
754 */
755 ASSERT(ndn->dn_handle->dnh_dnode == odn);
756 ndn->dn_handle->dnh_dnode = ndn;
757 if (ndn->dn_zfetch.zf_dnode == odn) {
758 ndn->dn_zfetch.zf_dnode = ndn;
759 }
760
761 /*
762 * Invalidate the original dnode by clearing all of its back pointers.
763 */
764 odn->dn_dbuf = NULL;
765 odn->dn_handle = NULL;
766 avl_create(&odn->dn_dbufs, dbuf_compare, sizeof (dmu_buf_impl_t),
767 offsetof(dmu_buf_impl_t, db_link));
768 odn->dn_dbufs_count = 0;
769 odn->dn_unlisted_l0_blkid = 0;
770 odn->dn_bonus = NULL;
771 odn->dn_zfetch.zf_dnode = NULL;
772
773 /*
774 * Set the low bit of the objset pointer to ensure that dnode_move()
775 * recognizes the dnode as invalid in any subsequent callback.
776 */
777 POINTER_INVALIDATE(&odn->dn_objset);
778
779 /*
780 * Satisfy the destructor.
781 */
782 for (i = 0; i < TXG_SIZE; i++) {
783 list_create(&odn->dn_dirty_records[i],
784 sizeof (dbuf_dirty_record_t),
785 offsetof(dbuf_dirty_record_t, dr_dirty_node));
786 odn->dn_free_ranges[i] = NULL;
787 odn->dn_next_nlevels[i] = 0;
788 odn->dn_next_indblkshift[i] = 0;
789 odn->dn_next_bonustype[i] = 0;
790 odn->dn_rm_spillblk[i] = 0;
791 odn->dn_next_bonuslen[i] = 0;
792 odn->dn_next_blksz[i] = 0;
793 }
794 odn->dn_allocated_txg = 0;
795 odn->dn_free_txg = 0;
796 odn->dn_assigned_txg = 0;
797 odn->dn_dirtyctx = 0;
798 odn->dn_dirtyctx_firstset = NULL;
799 odn->dn_have_spill = B_FALSE;
800 odn->dn_zio = NULL;
801 odn->dn_oldused = 0;
802 odn->dn_oldflags = 0;
803 odn->dn_olduid = 0;
804 odn->dn_oldgid = 0;
805 odn->dn_newuid = 0;
806 odn->dn_newgid = 0;
807 odn->dn_id_flags = 0;
808
809 /*
810 * Mark the dnode.
811 */
812 ndn->dn_moved = 1;
813 odn->dn_moved = (uint8_t)-1;
814 }
815
816 #ifdef sun
817 #ifdef _KERNEL
818 /*ARGSUSED*/
819 static kmem_cbrc_t
dnode_move(void * buf,void * newbuf,size_t size,void * arg)820 dnode_move(void *buf, void *newbuf, size_t size, void *arg)
821 {
822 dnode_t *odn = buf, *ndn = newbuf;
823 objset_t *os;
824 int64_t refcount;
825 uint32_t dbufs;
826
827 /*
828 * The dnode is on the objset's list of known dnodes if the objset
829 * pointer is valid. We set the low bit of the objset pointer when
830 * freeing the dnode to invalidate it, and the memory patterns written
831 * by kmem (baddcafe and deadbeef) set at least one of the two low bits.
832 * A newly created dnode sets the objset pointer last of all to indicate
833 * that the dnode is known and in a valid state to be moved by this
834 * function.
835 */
836 os = odn->dn_objset;
837 if (!POINTER_IS_VALID(os)) {
838 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_invalid);
839 return (KMEM_CBRC_DONT_KNOW);
840 }
841
842 /*
843 * Ensure that the objset does not go away during the move.
844 */
845 rw_enter(&os_lock, RW_WRITER);
846 if (os != odn->dn_objset) {
847 rw_exit(&os_lock);
848 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_recheck1);
849 return (KMEM_CBRC_DONT_KNOW);
850 }
851
852 /*
853 * If the dnode is still valid, then so is the objset. We know that no
854 * valid objset can be freed while we hold os_lock, so we can safely
855 * ensure that the objset remains in use.
856 */
857 mutex_enter(&os->os_lock);
858
859 /*
860 * Recheck the objset pointer in case the dnode was removed just before
861 * acquiring the lock.
862 */
863 if (os != odn->dn_objset) {
864 mutex_exit(&os->os_lock);
865 rw_exit(&os_lock);
866 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_recheck2);
867 return (KMEM_CBRC_DONT_KNOW);
868 }
869
870 /*
871 * At this point we know that as long as we hold os->os_lock, the dnode
872 * cannot be freed and fields within the dnode can be safely accessed.
873 * The objset listing this dnode cannot go away as long as this dnode is
874 * on its list.
875 */
876 rw_exit(&os_lock);
877 if (DMU_OBJECT_IS_SPECIAL(odn->dn_object)) {
878 mutex_exit(&os->os_lock);
879 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_special);
880 return (KMEM_CBRC_NO);
881 }
882 ASSERT(odn->dn_dbuf != NULL); /* only "special" dnodes have no parent */
883
884 /*
885 * Lock the dnode handle to prevent the dnode from obtaining any new
886 * holds. This also prevents the descendant dbufs and the bonus dbuf
887 * from accessing the dnode, so that we can discount their holds. The
888 * handle is safe to access because we know that while the dnode cannot
889 * go away, neither can its handle. Once we hold dnh_zrlock, we can
890 * safely move any dnode referenced only by dbufs.
891 */
892 if (!zrl_tryenter(&odn->dn_handle->dnh_zrlock)) {
893 mutex_exit(&os->os_lock);
894 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_handle);
895 return (KMEM_CBRC_LATER);
896 }
897
898 /*
899 * Ensure a consistent view of the dnode's holds and the dnode's dbufs.
900 * We need to guarantee that there is a hold for every dbuf in order to
901 * determine whether the dnode is actively referenced. Falsely matching
902 * a dbuf to an active hold would lead to an unsafe move. It's possible
903 * that a thread already having an active dnode hold is about to add a
904 * dbuf, and we can't compare hold and dbuf counts while the add is in
905 * progress.
906 */
907 if (!rw_tryenter(&odn->dn_struct_rwlock, RW_WRITER)) {
908 zrl_exit(&odn->dn_handle->dnh_zrlock);
909 mutex_exit(&os->os_lock);
910 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_rwlock);
911 return (KMEM_CBRC_LATER);
912 }
913
914 /*
915 * A dbuf may be removed (evicted) without an active dnode hold. In that
916 * case, the dbuf count is decremented under the handle lock before the
917 * dbuf's hold is released. This order ensures that if we count the hold
918 * after the dbuf is removed but before its hold is released, we will
919 * treat the unmatched hold as active and exit safely. If we count the
920 * hold before the dbuf is removed, the hold is discounted, and the
921 * removal is blocked until the move completes.
922 */
923 refcount = refcount_count(&odn->dn_holds);
924 ASSERT(refcount >= 0);
925 dbufs = odn->dn_dbufs_count;
926
927 /* We can't have more dbufs than dnode holds. */
928 ASSERT3U(dbufs, <=, refcount);
929 DTRACE_PROBE3(dnode__move, dnode_t *, odn, int64_t, refcount,
930 uint32_t, dbufs);
931
932 if (refcount > dbufs) {
933 rw_exit(&odn->dn_struct_rwlock);
934 zrl_exit(&odn->dn_handle->dnh_zrlock);
935 mutex_exit(&os->os_lock);
936 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_active);
937 return (KMEM_CBRC_LATER);
938 }
939
940 rw_exit(&odn->dn_struct_rwlock);
941
942 /*
943 * At this point we know that anyone with a hold on the dnode is not
944 * actively referencing it. The dnode is known and in a valid state to
945 * move. We're holding the locks needed to execute the critical section.
946 */
947 dnode_move_impl(odn, ndn);
948
949 list_link_replace(&odn->dn_link, &ndn->dn_link);
950 /* If the dnode was safe to move, the refcount cannot have changed. */
951 ASSERT(refcount == refcount_count(&ndn->dn_holds));
952 ASSERT(dbufs == ndn->dn_dbufs_count);
953 zrl_exit(&ndn->dn_handle->dnh_zrlock); /* handle has moved */
954 mutex_exit(&os->os_lock);
955
956 return (KMEM_CBRC_YES);
957 }
958 #endif /* _KERNEL */
959 #endif /* sun */
960
961 void
dnode_special_close(dnode_handle_t * dnh)962 dnode_special_close(dnode_handle_t *dnh)
963 {
964 dnode_t *dn = dnh->dnh_dnode;
965
966 /*
967 * Wait for final references to the dnode to clear. This can
968 * only happen if the arc is asyncronously evicting state that
969 * has a hold on this dnode while we are trying to evict this
970 * dnode.
971 */
972 while (refcount_count(&dn->dn_holds) > 0)
973 delay(1);
974 zrl_add(&dnh->dnh_zrlock);
975 dnode_destroy(dn); /* implicit zrl_remove() */
976 zrl_destroy(&dnh->dnh_zrlock);
977 dnh->dnh_dnode = NULL;
978 }
979
980 dnode_t *
dnode_special_open(objset_t * os,dnode_phys_t * dnp,uint64_t object,dnode_handle_t * dnh)981 dnode_special_open(objset_t *os, dnode_phys_t *dnp, uint64_t object,
982 dnode_handle_t *dnh)
983 {
984 dnode_t *dn = dnode_create(os, dnp, NULL, object, dnh);
985 dnh->dnh_dnode = dn;
986 zrl_init(&dnh->dnh_zrlock);
987 DNODE_VERIFY(dn);
988 return (dn);
989 }
990
991 static void
dnode_buf_pageout(dmu_buf_t * db,void * arg)992 dnode_buf_pageout(dmu_buf_t *db, void *arg)
993 {
994 dnode_children_t *children_dnodes = arg;
995 int i;
996 int epb = db->db_size >> DNODE_SHIFT;
997
998 ASSERT(epb == children_dnodes->dnc_count);
999
1000 for (i = 0; i < epb; i++) {
1001 dnode_handle_t *dnh = &children_dnodes->dnc_children[i];
1002 dnode_t *dn;
1003
1004 /*
1005 * The dnode handle lock guards against the dnode moving to
1006 * another valid address, so there is no need here to guard
1007 * against changes to or from NULL.
1008 */
1009 if (dnh->dnh_dnode == NULL) {
1010 zrl_destroy(&dnh->dnh_zrlock);
1011 continue;
1012 }
1013
1014 zrl_add(&dnh->dnh_zrlock);
1015 dn = dnh->dnh_dnode;
1016 /*
1017 * If there are holds on this dnode, then there should
1018 * be holds on the dnode's containing dbuf as well; thus
1019 * it wouldn't be eligible for eviction and this function
1020 * would not have been called.
1021 */
1022 ASSERT(refcount_is_zero(&dn->dn_holds));
1023 ASSERT(refcount_is_zero(&dn->dn_tx_holds));
1024
1025 dnode_destroy(dn); /* implicit zrl_remove() */
1026 zrl_destroy(&dnh->dnh_zrlock);
1027 dnh->dnh_dnode = NULL;
1028 }
1029 kmem_free(children_dnodes, sizeof (dnode_children_t) +
1030 epb * sizeof (dnode_handle_t));
1031 }
1032
1033 /*
1034 * errors:
1035 * EINVAL - invalid object number.
1036 * EIO - i/o error.
1037 * succeeds even for free dnodes.
1038 */
1039 int
dnode_hold_impl(objset_t * os,uint64_t object,int flag,void * tag,dnode_t ** dnp)1040 dnode_hold_impl(objset_t *os, uint64_t object, int flag,
1041 void *tag, dnode_t **dnp)
1042 {
1043 int epb, idx, err;
1044 int drop_struct_lock = FALSE;
1045 int type;
1046 uint64_t blk;
1047 dnode_t *mdn, *dn;
1048 dmu_buf_impl_t *db;
1049 dnode_children_t *children_dnodes;
1050 dnode_handle_t *dnh;
1051
1052 /*
1053 * If you are holding the spa config lock as writer, you shouldn't
1054 * be asking the DMU to do *anything* unless it's the root pool
1055 * which may require us to read from the root filesystem while
1056 * holding some (not all) of the locks as writer.
1057 */
1058 ASSERT(spa_config_held(os->os_spa, SCL_ALL, RW_WRITER) == 0 ||
1059 (spa_is_root(os->os_spa) &&
1060 spa_config_held(os->os_spa, SCL_STATE, RW_WRITER)));
1061
1062 if (object == DMU_USERUSED_OBJECT || object == DMU_GROUPUSED_OBJECT) {
1063 dn = (object == DMU_USERUSED_OBJECT) ?
1064 DMU_USERUSED_DNODE(os) : DMU_GROUPUSED_DNODE(os);
1065 if (dn == NULL)
1066 return (SET_ERROR(ENOENT));
1067 type = dn->dn_type;
1068 if ((flag & DNODE_MUST_BE_ALLOCATED) && type == DMU_OT_NONE)
1069 return (SET_ERROR(ENOENT));
1070 if ((flag & DNODE_MUST_BE_FREE) && type != DMU_OT_NONE)
1071 return (SET_ERROR(EEXIST));
1072 DNODE_VERIFY(dn);
1073 (void) refcount_add(&dn->dn_holds, tag);
1074 *dnp = dn;
1075 return (0);
1076 }
1077
1078 if (object == 0 || object >= DN_MAX_OBJECT)
1079 return (SET_ERROR(EINVAL));
1080
1081 mdn = DMU_META_DNODE(os);
1082 ASSERT(mdn->dn_object == DMU_META_DNODE_OBJECT);
1083
1084 DNODE_VERIFY(mdn);
1085
1086 if (!RW_WRITE_HELD(&mdn->dn_struct_rwlock)) {
1087 rw_enter(&mdn->dn_struct_rwlock, RW_READER);
1088 drop_struct_lock = TRUE;
1089 }
1090
1091 blk = dbuf_whichblock(mdn, object * sizeof (dnode_phys_t));
1092
1093 db = dbuf_hold(mdn, blk, FTAG);
1094 if (drop_struct_lock)
1095 rw_exit(&mdn->dn_struct_rwlock);
1096 if (db == NULL)
1097 return (SET_ERROR(EIO));
1098 err = dbuf_read(db, NULL, DB_RF_CANFAIL);
1099 if (err) {
1100 dbuf_rele(db, FTAG);
1101 return (err);
1102 }
1103
1104 ASSERT3U(db->db.db_size, >=, 1<<DNODE_SHIFT);
1105 epb = db->db.db_size >> DNODE_SHIFT;
1106
1107 idx = object & (epb-1);
1108
1109 ASSERT(DB_DNODE(db)->dn_type == DMU_OT_DNODE);
1110 children_dnodes = dmu_buf_get_user(&db->db);
1111 if (children_dnodes == NULL) {
1112 int i;
1113 dnode_children_t *winner;
1114 children_dnodes = kmem_zalloc(sizeof (dnode_children_t) +
1115 epb * sizeof (dnode_handle_t), KM_SLEEP);
1116 children_dnodes->dnc_count = epb;
1117 dnh = &children_dnodes->dnc_children[0];
1118 for (i = 0; i < epb; i++) {
1119 zrl_init(&dnh[i].dnh_zrlock);
1120 dnh[i].dnh_dnode = NULL;
1121 }
1122 if (winner = dmu_buf_set_user(&db->db, children_dnodes,
1123 dnode_buf_pageout)) {
1124
1125 for (i = 0; i < epb; i++) {
1126 zrl_destroy(&dnh[i].dnh_zrlock);
1127 }
1128
1129 kmem_free(children_dnodes, sizeof (dnode_children_t) +
1130 epb * sizeof (dnode_handle_t));
1131 children_dnodes = winner;
1132 }
1133 }
1134 ASSERT(children_dnodes->dnc_count == epb);
1135
1136 dnh = &children_dnodes->dnc_children[idx];
1137 zrl_add(&dnh->dnh_zrlock);
1138 if ((dn = dnh->dnh_dnode) == NULL) {
1139 dnode_phys_t *phys = (dnode_phys_t *)db->db.db_data+idx;
1140 dnode_t *winner;
1141
1142 dn = dnode_create(os, phys, db, object, dnh);
1143 winner = atomic_cas_ptr(&dnh->dnh_dnode, NULL, dn);
1144 if (winner != NULL) {
1145 zrl_add(&dnh->dnh_zrlock);
1146 dnode_destroy(dn); /* implicit zrl_remove() */
1147 dn = winner;
1148 }
1149 }
1150
1151 mutex_enter(&dn->dn_mtx);
1152 type = dn->dn_type;
1153 if (dn->dn_free_txg ||
1154 ((flag & DNODE_MUST_BE_ALLOCATED) && type == DMU_OT_NONE) ||
1155 ((flag & DNODE_MUST_BE_FREE) &&
1156 (type != DMU_OT_NONE || !refcount_is_zero(&dn->dn_holds)))) {
1157 mutex_exit(&dn->dn_mtx);
1158 zrl_remove(&dnh->dnh_zrlock);
1159 dbuf_rele(db, FTAG);
1160 return (type == DMU_OT_NONE ? ENOENT : EEXIST);
1161 }
1162 mutex_exit(&dn->dn_mtx);
1163
1164 if (refcount_add(&dn->dn_holds, tag) == 1)
1165 dbuf_add_ref(db, dnh);
1166 /* Now we can rely on the hold to prevent the dnode from moving. */
1167 zrl_remove(&dnh->dnh_zrlock);
1168
1169 DNODE_VERIFY(dn);
1170 ASSERT3P(dn->dn_dbuf, ==, db);
1171 ASSERT3U(dn->dn_object, ==, object);
1172 dbuf_rele(db, FTAG);
1173
1174 *dnp = dn;
1175 return (0);
1176 }
1177
1178 /*
1179 * Return held dnode if the object is allocated, NULL if not.
1180 */
1181 int
dnode_hold(objset_t * os,uint64_t object,void * tag,dnode_t ** dnp)1182 dnode_hold(objset_t *os, uint64_t object, void *tag, dnode_t **dnp)
1183 {
1184 return (dnode_hold_impl(os, object, DNODE_MUST_BE_ALLOCATED, tag, dnp));
1185 }
1186
1187 /*
1188 * Can only add a reference if there is already at least one
1189 * reference on the dnode. Returns FALSE if unable to add a
1190 * new reference.
1191 */
1192 boolean_t
dnode_add_ref(dnode_t * dn,void * tag)1193 dnode_add_ref(dnode_t *dn, void *tag)
1194 {
1195 mutex_enter(&dn->dn_mtx);
1196 if (refcount_is_zero(&dn->dn_holds)) {
1197 mutex_exit(&dn->dn_mtx);
1198 return (FALSE);
1199 }
1200 VERIFY(1 < refcount_add(&dn->dn_holds, tag));
1201 mutex_exit(&dn->dn_mtx);
1202 return (TRUE);
1203 }
1204
1205 void
dnode_rele(dnode_t * dn,void * tag)1206 dnode_rele(dnode_t *dn, void *tag)
1207 {
1208 uint64_t refs;
1209 /* Get while the hold prevents the dnode from moving. */
1210 dmu_buf_impl_t *db = dn->dn_dbuf;
1211 dnode_handle_t *dnh = dn->dn_handle;
1212
1213 mutex_enter(&dn->dn_mtx);
1214 refs = refcount_remove(&dn->dn_holds, tag);
1215 mutex_exit(&dn->dn_mtx);
1216
1217 /*
1218 * It's unsafe to release the last hold on a dnode by dnode_rele() or
1219 * indirectly by dbuf_rele() while relying on the dnode handle to
1220 * prevent the dnode from moving, since releasing the last hold could
1221 * result in the dnode's parent dbuf evicting its dnode handles. For
1222 * that reason anyone calling dnode_rele() or dbuf_rele() without some
1223 * other direct or indirect hold on the dnode must first drop the dnode
1224 * handle.
1225 */
1226 ASSERT(refs > 0 || dnh->dnh_zrlock.zr_owner != curthread);
1227
1228 /* NOTE: the DNODE_DNODE does not have a dn_dbuf */
1229 if (refs == 0 && db != NULL) {
1230 /*
1231 * Another thread could add a hold to the dnode handle in
1232 * dnode_hold_impl() while holding the parent dbuf. Since the
1233 * hold on the parent dbuf prevents the handle from being
1234 * destroyed, the hold on the handle is OK. We can't yet assert
1235 * that the handle has zero references, but that will be
1236 * asserted anyway when the handle gets destroyed.
1237 */
1238 dbuf_rele(db, dnh);
1239 }
1240 }
1241
1242 void
dnode_setdirty(dnode_t * dn,dmu_tx_t * tx)1243 dnode_setdirty(dnode_t *dn, dmu_tx_t *tx)
1244 {
1245 objset_t *os = dn->dn_objset;
1246 uint64_t txg = tx->tx_txg;
1247
1248 if (DMU_OBJECT_IS_SPECIAL(dn->dn_object)) {
1249 dsl_dataset_dirty(os->os_dsl_dataset, tx);
1250 return;
1251 }
1252
1253 DNODE_VERIFY(dn);
1254
1255 #ifdef ZFS_DEBUG
1256 mutex_enter(&dn->dn_mtx);
1257 ASSERT(dn->dn_phys->dn_type || dn->dn_allocated_txg);
1258 ASSERT(dn->dn_free_txg == 0 || dn->dn_free_txg >= txg);
1259 mutex_exit(&dn->dn_mtx);
1260 #endif
1261
1262 /*
1263 * Determine old uid/gid when necessary
1264 */
1265 dmu_objset_userquota_get_ids(dn, B_TRUE, tx);
1266
1267 mutex_enter(&os->os_lock);
1268
1269 /*
1270 * If we are already marked dirty, we're done.
1271 */
1272 if (list_link_active(&dn->dn_dirty_link[txg & TXG_MASK])) {
1273 mutex_exit(&os->os_lock);
1274 return;
1275 }
1276
1277 ASSERT(!refcount_is_zero(&dn->dn_holds) ||
1278 !avl_is_empty(&dn->dn_dbufs));
1279 ASSERT(dn->dn_datablksz != 0);
1280 ASSERT0(dn->dn_next_bonuslen[txg&TXG_MASK]);
1281 ASSERT0(dn->dn_next_blksz[txg&TXG_MASK]);
1282 ASSERT0(dn->dn_next_bonustype[txg&TXG_MASK]);
1283
1284 dprintf_ds(os->os_dsl_dataset, "obj=%llu txg=%llu\n",
1285 dn->dn_object, txg);
1286
1287 if (dn->dn_free_txg > 0 && dn->dn_free_txg <= txg) {
1288 list_insert_tail(&os->os_free_dnodes[txg&TXG_MASK], dn);
1289 } else {
1290 list_insert_tail(&os->os_dirty_dnodes[txg&TXG_MASK], dn);
1291 }
1292
1293 mutex_exit(&os->os_lock);
1294
1295 /*
1296 * The dnode maintains a hold on its containing dbuf as
1297 * long as there are holds on it. Each instantiated child
1298 * dbuf maintains a hold on the dnode. When the last child
1299 * drops its hold, the dnode will drop its hold on the
1300 * containing dbuf. We add a "dirty hold" here so that the
1301 * dnode will hang around after we finish processing its
1302 * children.
1303 */
1304 VERIFY(dnode_add_ref(dn, (void *)(uintptr_t)tx->tx_txg));
1305
1306 (void) dbuf_dirty(dn->dn_dbuf, tx);
1307
1308 dsl_dataset_dirty(os->os_dsl_dataset, tx);
1309 }
1310
1311 void
dnode_free(dnode_t * dn,dmu_tx_t * tx)1312 dnode_free(dnode_t *dn, dmu_tx_t *tx)
1313 {
1314 int txgoff = tx->tx_txg & TXG_MASK;
1315
1316 dprintf("dn=%p txg=%llu\n", dn, tx->tx_txg);
1317
1318 /* we should be the only holder... hopefully */
1319 /* ASSERT3U(refcount_count(&dn->dn_holds), ==, 1); */
1320
1321 mutex_enter(&dn->dn_mtx);
1322 if (dn->dn_type == DMU_OT_NONE || dn->dn_free_txg) {
1323 mutex_exit(&dn->dn_mtx);
1324 return;
1325 }
1326 dn->dn_free_txg = tx->tx_txg;
1327 mutex_exit(&dn->dn_mtx);
1328
1329 /*
1330 * If the dnode is already dirty, it needs to be moved from
1331 * the dirty list to the free list.
1332 */
1333 mutex_enter(&dn->dn_objset->os_lock);
1334 if (list_link_active(&dn->dn_dirty_link[txgoff])) {
1335 list_remove(&dn->dn_objset->os_dirty_dnodes[txgoff], dn);
1336 list_insert_tail(&dn->dn_objset->os_free_dnodes[txgoff], dn);
1337 mutex_exit(&dn->dn_objset->os_lock);
1338 } else {
1339 mutex_exit(&dn->dn_objset->os_lock);
1340 dnode_setdirty(dn, tx);
1341 }
1342 }
1343
1344 /*
1345 * Try to change the block size for the indicated dnode. This can only
1346 * succeed if there are no blocks allocated or dirty beyond first block
1347 */
1348 int
dnode_set_blksz(dnode_t * dn,uint64_t size,int ibs,dmu_tx_t * tx)1349 dnode_set_blksz(dnode_t *dn, uint64_t size, int ibs, dmu_tx_t *tx)
1350 {
1351 dmu_buf_impl_t *db;
1352 int err;
1353
1354 ASSERT3U(size, <=, spa_maxblocksize(dmu_objset_spa(dn->dn_objset)));
1355 if (size == 0)
1356 size = SPA_MINBLOCKSIZE;
1357 else
1358 size = P2ROUNDUP(size, SPA_MINBLOCKSIZE);
1359
1360 if (ibs == dn->dn_indblkshift)
1361 ibs = 0;
1362
1363 if (size >> SPA_MINBLOCKSHIFT == dn->dn_datablkszsec && ibs == 0)
1364 return (0);
1365
1366 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
1367
1368 /* Check for any allocated blocks beyond the first */
1369 if (dn->dn_maxblkid != 0)
1370 goto fail;
1371
1372 mutex_enter(&dn->dn_dbufs_mtx);
1373 for (db = avl_first(&dn->dn_dbufs); db != NULL;
1374 db = AVL_NEXT(&dn->dn_dbufs, db)) {
1375 if (db->db_blkid != 0 && db->db_blkid != DMU_BONUS_BLKID &&
1376 db->db_blkid != DMU_SPILL_BLKID) {
1377 mutex_exit(&dn->dn_dbufs_mtx);
1378 goto fail;
1379 }
1380 }
1381 mutex_exit(&dn->dn_dbufs_mtx);
1382
1383 if (ibs && dn->dn_nlevels != 1)
1384 goto fail;
1385
1386 /* resize the old block */
1387 err = dbuf_hold_impl(dn, 0, 0, TRUE, FTAG, &db);
1388 if (err == 0)
1389 dbuf_new_size(db, size, tx);
1390 else if (err != ENOENT)
1391 goto fail;
1392
1393 dnode_setdblksz(dn, size);
1394 dnode_setdirty(dn, tx);
1395 dn->dn_next_blksz[tx->tx_txg&TXG_MASK] = size;
1396 if (ibs) {
1397 dn->dn_indblkshift = ibs;
1398 dn->dn_next_indblkshift[tx->tx_txg&TXG_MASK] = ibs;
1399 }
1400 /* rele after we have fixed the blocksize in the dnode */
1401 if (db)
1402 dbuf_rele(db, FTAG);
1403
1404 rw_exit(&dn->dn_struct_rwlock);
1405 return (0);
1406
1407 fail:
1408 rw_exit(&dn->dn_struct_rwlock);
1409 return (SET_ERROR(ENOTSUP));
1410 }
1411
1412 /* read-holding callers must not rely on the lock being continuously held */
1413 void
dnode_new_blkid(dnode_t * dn,uint64_t blkid,dmu_tx_t * tx,boolean_t have_read)1414 dnode_new_blkid(dnode_t *dn, uint64_t blkid, dmu_tx_t *tx, boolean_t have_read)
1415 {
1416 uint64_t txgoff = tx->tx_txg & TXG_MASK;
1417 int epbs, new_nlevels;
1418 uint64_t sz;
1419
1420 ASSERT(blkid != DMU_BONUS_BLKID);
1421
1422 ASSERT(have_read ?
1423 RW_READ_HELD(&dn->dn_struct_rwlock) :
1424 RW_WRITE_HELD(&dn->dn_struct_rwlock));
1425
1426 /*
1427 * if we have a read-lock, check to see if we need to do any work
1428 * before upgrading to a write-lock.
1429 */
1430 if (have_read) {
1431 if (blkid <= dn->dn_maxblkid)
1432 return;
1433
1434 if (!rw_tryupgrade(&dn->dn_struct_rwlock)) {
1435 rw_exit(&dn->dn_struct_rwlock);
1436 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
1437 }
1438 }
1439
1440 if (blkid <= dn->dn_maxblkid)
1441 goto out;
1442
1443 dn->dn_maxblkid = blkid;
1444
1445 /*
1446 * Compute the number of levels necessary to support the new maxblkid.
1447 */
1448 new_nlevels = 1;
1449 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT;
1450 for (sz = dn->dn_nblkptr;
1451 sz <= blkid && sz >= dn->dn_nblkptr; sz <<= epbs)
1452 new_nlevels++;
1453
1454 if (new_nlevels > dn->dn_nlevels) {
1455 int old_nlevels = dn->dn_nlevels;
1456 dmu_buf_impl_t *db;
1457 list_t *list;
1458 dbuf_dirty_record_t *new, *dr, *dr_next;
1459
1460 dn->dn_nlevels = new_nlevels;
1461
1462 ASSERT3U(new_nlevels, >, dn->dn_next_nlevels[txgoff]);
1463 dn->dn_next_nlevels[txgoff] = new_nlevels;
1464
1465 /* dirty the left indirects */
1466 db = dbuf_hold_level(dn, old_nlevels, 0, FTAG);
1467 ASSERT(db != NULL);
1468 new = dbuf_dirty(db, tx);
1469 dbuf_rele(db, FTAG);
1470
1471 /* transfer the dirty records to the new indirect */
1472 mutex_enter(&dn->dn_mtx);
1473 mutex_enter(&new->dt.di.dr_mtx);
1474 list = &dn->dn_dirty_records[txgoff];
1475 for (dr = list_head(list); dr; dr = dr_next) {
1476 dr_next = list_next(&dn->dn_dirty_records[txgoff], dr);
1477 if (dr->dr_dbuf->db_level != new_nlevels-1 &&
1478 dr->dr_dbuf->db_blkid != DMU_BONUS_BLKID &&
1479 dr->dr_dbuf->db_blkid != DMU_SPILL_BLKID) {
1480 ASSERT(dr->dr_dbuf->db_level == old_nlevels-1);
1481 list_remove(&dn->dn_dirty_records[txgoff], dr);
1482 list_insert_tail(&new->dt.di.dr_children, dr);
1483 dr->dr_parent = new;
1484 }
1485 }
1486 mutex_exit(&new->dt.di.dr_mtx);
1487 mutex_exit(&dn->dn_mtx);
1488 }
1489
1490 out:
1491 if (have_read)
1492 rw_downgrade(&dn->dn_struct_rwlock);
1493 }
1494
1495 void
dnode_free_range(dnode_t * dn,uint64_t off,uint64_t len,dmu_tx_t * tx)1496 dnode_free_range(dnode_t *dn, uint64_t off, uint64_t len, dmu_tx_t *tx)
1497 {
1498 dmu_buf_impl_t *db;
1499 uint64_t blkoff, blkid, nblks;
1500 int blksz, blkshift, head, tail;
1501 int trunc = FALSE;
1502 int epbs;
1503
1504 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
1505 blksz = dn->dn_datablksz;
1506 blkshift = dn->dn_datablkshift;
1507 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT;
1508
1509 if (len == DMU_OBJECT_END) {
1510 len = UINT64_MAX - off;
1511 trunc = TRUE;
1512 }
1513
1514 /*
1515 * First, block align the region to free:
1516 */
1517 if (ISP2(blksz)) {
1518 head = P2NPHASE(off, blksz);
1519 blkoff = P2PHASE(off, blksz);
1520 if ((off >> blkshift) > dn->dn_maxblkid)
1521 goto out;
1522 } else {
1523 ASSERT(dn->dn_maxblkid == 0);
1524 if (off == 0 && len >= blksz) {
1525 /*
1526 * Freeing the whole block; fast-track this request.
1527 * Note that we won't dirty any indirect blocks,
1528 * which is fine because we will be freeing the entire
1529 * file and thus all indirect blocks will be freed
1530 * by free_children().
1531 */
1532 blkid = 0;
1533 nblks = 1;
1534 goto done;
1535 } else if (off >= blksz) {
1536 /* Freeing past end-of-data */
1537 goto out;
1538 } else {
1539 /* Freeing part of the block. */
1540 head = blksz - off;
1541 ASSERT3U(head, >, 0);
1542 }
1543 blkoff = off;
1544 }
1545 /* zero out any partial block data at the start of the range */
1546 if (head) {
1547 ASSERT3U(blkoff + head, ==, blksz);
1548 if (len < head)
1549 head = len;
1550 if (dbuf_hold_impl(dn, 0, dbuf_whichblock(dn, off), TRUE,
1551 FTAG, &db) == 0) {
1552 caddr_t data;
1553
1554 /* don't dirty if it isn't on disk and isn't dirty */
1555 if (db->db_last_dirty ||
1556 (db->db_blkptr && !BP_IS_HOLE(db->db_blkptr))) {
1557 rw_exit(&dn->dn_struct_rwlock);
1558 dmu_buf_will_dirty(&db->db, tx);
1559 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
1560 data = db->db.db_data;
1561 bzero(data + blkoff, head);
1562 }
1563 dbuf_rele(db, FTAG);
1564 }
1565 off += head;
1566 len -= head;
1567 }
1568
1569 /* If the range was less than one block, we're done */
1570 if (len == 0)
1571 goto out;
1572
1573 /* If the remaining range is past end of file, we're done */
1574 if ((off >> blkshift) > dn->dn_maxblkid)
1575 goto out;
1576
1577 ASSERT(ISP2(blksz));
1578 if (trunc)
1579 tail = 0;
1580 else
1581 tail = P2PHASE(len, blksz);
1582
1583 ASSERT0(P2PHASE(off, blksz));
1584 /* zero out any partial block data at the end of the range */
1585 if (tail) {
1586 if (len < tail)
1587 tail = len;
1588 if (dbuf_hold_impl(dn, 0, dbuf_whichblock(dn, off+len),
1589 TRUE, FTAG, &db) == 0) {
1590 /* don't dirty if not on disk and not dirty */
1591 if (db->db_last_dirty ||
1592 (db->db_blkptr && !BP_IS_HOLE(db->db_blkptr))) {
1593 rw_exit(&dn->dn_struct_rwlock);
1594 dmu_buf_will_dirty(&db->db, tx);
1595 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
1596 bzero(db->db.db_data, tail);
1597 }
1598 dbuf_rele(db, FTAG);
1599 }
1600 len -= tail;
1601 }
1602
1603 /* If the range did not include a full block, we are done */
1604 if (len == 0)
1605 goto out;
1606
1607 ASSERT(IS_P2ALIGNED(off, blksz));
1608 ASSERT(trunc || IS_P2ALIGNED(len, blksz));
1609 blkid = off >> blkshift;
1610 nblks = len >> blkshift;
1611 if (trunc)
1612 nblks += 1;
1613
1614 /*
1615 * Dirty the first and last indirect blocks, as they (and/or their
1616 * parents) will need to be written out if they were only
1617 * partially freed. Interior indirect blocks will be themselves freed,
1618 * by free_children(), so they need not be dirtied. Note that these
1619 * interior blocks have already been prefetched by dmu_tx_hold_free().
1620 */
1621 if (dn->dn_nlevels > 1) {
1622 uint64_t first, last;
1623
1624 first = blkid >> epbs;
1625 if (db = dbuf_hold_level(dn, 1, first, FTAG)) {
1626 dmu_buf_will_dirty(&db->db, tx);
1627 dbuf_rele(db, FTAG);
1628 }
1629 if (trunc)
1630 last = dn->dn_maxblkid >> epbs;
1631 else
1632 last = (blkid + nblks - 1) >> epbs;
1633 if (last > first && (db = dbuf_hold_level(dn, 1, last, FTAG))) {
1634 dmu_buf_will_dirty(&db->db, tx);
1635 dbuf_rele(db, FTAG);
1636 }
1637 }
1638
1639 done:
1640 /*
1641 * Add this range to the dnode range list.
1642 * We will finish up this free operation in the syncing phase.
1643 */
1644 mutex_enter(&dn->dn_mtx);
1645 int txgoff = tx->tx_txg & TXG_MASK;
1646 if (dn->dn_free_ranges[txgoff] == NULL) {
1647 dn->dn_free_ranges[txgoff] =
1648 range_tree_create(NULL, NULL, &dn->dn_mtx);
1649 }
1650 range_tree_clear(dn->dn_free_ranges[txgoff], blkid, nblks);
1651 range_tree_add(dn->dn_free_ranges[txgoff], blkid, nblks);
1652 dprintf_dnode(dn, "blkid=%llu nblks=%llu txg=%llu\n",
1653 blkid, nblks, tx->tx_txg);
1654 mutex_exit(&dn->dn_mtx);
1655
1656 dbuf_free_range(dn, blkid, blkid + nblks - 1, tx);
1657 dnode_setdirty(dn, tx);
1658 out:
1659
1660 rw_exit(&dn->dn_struct_rwlock);
1661 }
1662
1663 static boolean_t
dnode_spill_freed(dnode_t * dn)1664 dnode_spill_freed(dnode_t *dn)
1665 {
1666 int i;
1667
1668 mutex_enter(&dn->dn_mtx);
1669 for (i = 0; i < TXG_SIZE; i++) {
1670 if (dn->dn_rm_spillblk[i] == DN_KILL_SPILLBLK)
1671 break;
1672 }
1673 mutex_exit(&dn->dn_mtx);
1674 return (i < TXG_SIZE);
1675 }
1676
1677 /* return TRUE if this blkid was freed in a recent txg, or FALSE if it wasn't */
1678 uint64_t
dnode_block_freed(dnode_t * dn,uint64_t blkid)1679 dnode_block_freed(dnode_t *dn, uint64_t blkid)
1680 {
1681 void *dp = spa_get_dsl(dn->dn_objset->os_spa);
1682 int i;
1683
1684 if (blkid == DMU_BONUS_BLKID)
1685 return (FALSE);
1686
1687 /*
1688 * If we're in the process of opening the pool, dp will not be
1689 * set yet, but there shouldn't be anything dirty.
1690 */
1691 if (dp == NULL)
1692 return (FALSE);
1693
1694 if (dn->dn_free_txg)
1695 return (TRUE);
1696
1697 if (blkid == DMU_SPILL_BLKID)
1698 return (dnode_spill_freed(dn));
1699
1700 mutex_enter(&dn->dn_mtx);
1701 for (i = 0; i < TXG_SIZE; i++) {
1702 if (dn->dn_free_ranges[i] != NULL &&
1703 range_tree_contains(dn->dn_free_ranges[i], blkid, 1))
1704 break;
1705 }
1706 mutex_exit(&dn->dn_mtx);
1707 return (i < TXG_SIZE);
1708 }
1709
1710 /* call from syncing context when we actually write/free space for this dnode */
1711 void
dnode_diduse_space(dnode_t * dn,int64_t delta)1712 dnode_diduse_space(dnode_t *dn, int64_t delta)
1713 {
1714 uint64_t space;
1715 dprintf_dnode(dn, "dn=%p dnp=%p used=%llu delta=%lld\n",
1716 dn, dn->dn_phys,
1717 (u_longlong_t)dn->dn_phys->dn_used,
1718 (longlong_t)delta);
1719
1720 mutex_enter(&dn->dn_mtx);
1721 space = DN_USED_BYTES(dn->dn_phys);
1722 if (delta > 0) {
1723 ASSERT3U(space + delta, >=, space); /* no overflow */
1724 } else {
1725 ASSERT3U(space, >=, -delta); /* no underflow */
1726 }
1727 space += delta;
1728 if (spa_version(dn->dn_objset->os_spa) < SPA_VERSION_DNODE_BYTES) {
1729 ASSERT((dn->dn_phys->dn_flags & DNODE_FLAG_USED_BYTES) == 0);
1730 ASSERT0(P2PHASE(space, 1<<DEV_BSHIFT));
1731 dn->dn_phys->dn_used = space >> DEV_BSHIFT;
1732 } else {
1733 dn->dn_phys->dn_used = space;
1734 dn->dn_phys->dn_flags |= DNODE_FLAG_USED_BYTES;
1735 }
1736 mutex_exit(&dn->dn_mtx);
1737 }
1738
1739 /*
1740 * Call when we think we're going to write/free space in open context to track
1741 * the amount of memory in use by the currently open txg.
1742 */
1743 void
dnode_willuse_space(dnode_t * dn,int64_t space,dmu_tx_t * tx)1744 dnode_willuse_space(dnode_t *dn, int64_t space, dmu_tx_t *tx)
1745 {
1746 objset_t *os = dn->dn_objset;
1747 dsl_dataset_t *ds = os->os_dsl_dataset;
1748 int64_t aspace = spa_get_asize(os->os_spa, space);
1749
1750 if (ds != NULL) {
1751 dsl_dir_willuse_space(ds->ds_dir, aspace, tx);
1752 dsl_pool_dirty_space(dmu_tx_pool(tx), space, tx);
1753 }
1754
1755 dmu_tx_willuse_space(tx, aspace);
1756 }
1757
1758 /*
1759 * Scans a block at the indicated "level" looking for a hole or data,
1760 * depending on 'flags'.
1761 *
1762 * If level > 0, then we are scanning an indirect block looking at its
1763 * pointers. If level == 0, then we are looking at a block of dnodes.
1764 *
1765 * If we don't find what we are looking for in the block, we return ESRCH.
1766 * Otherwise, return with *offset pointing to the beginning (if searching
1767 * forwards) or end (if searching backwards) of the range covered by the
1768 * block pointer we matched on (or dnode).
1769 *
1770 * The basic search algorithm used below by dnode_next_offset() is to
1771 * use this function to search up the block tree (widen the search) until
1772 * we find something (i.e., we don't return ESRCH) and then search back
1773 * down the tree (narrow the search) until we reach our original search
1774 * level.
1775 */
1776 static int
dnode_next_offset_level(dnode_t * dn,int flags,uint64_t * offset,int lvl,uint64_t blkfill,uint64_t txg)1777 dnode_next_offset_level(dnode_t *dn, int flags, uint64_t *offset,
1778 int lvl, uint64_t blkfill, uint64_t txg)
1779 {
1780 dmu_buf_impl_t *db = NULL;
1781 void *data = NULL;
1782 uint64_t epbs = dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT;
1783 uint64_t epb = 1ULL << epbs;
1784 uint64_t minfill, maxfill;
1785 boolean_t hole;
1786 int i, inc, error, span;
1787
1788 dprintf("probing object %llu offset %llx level %d of %u\n",
1789 dn->dn_object, *offset, lvl, dn->dn_phys->dn_nlevels);
1790
1791 hole = ((flags & DNODE_FIND_HOLE) != 0);
1792 inc = (flags & DNODE_FIND_BACKWARDS) ? -1 : 1;
1793 ASSERT(txg == 0 || !hole);
1794
1795 if (lvl == dn->dn_phys->dn_nlevels) {
1796 error = 0;
1797 epb = dn->dn_phys->dn_nblkptr;
1798 data = dn->dn_phys->dn_blkptr;
1799 } else {
1800 uint64_t blkid = dbuf_whichblock(dn, *offset) >> (epbs * lvl);
1801 error = dbuf_hold_impl(dn, lvl, blkid, TRUE, FTAG, &db);
1802 if (error) {
1803 if (error != ENOENT)
1804 return (error);
1805 if (hole)
1806 return (0);
1807 /*
1808 * This can only happen when we are searching up
1809 * the block tree for data. We don't really need to
1810 * adjust the offset, as we will just end up looking
1811 * at the pointer to this block in its parent, and its
1812 * going to be unallocated, so we will skip over it.
1813 */
1814 return (SET_ERROR(ESRCH));
1815 }
1816 error = dbuf_read(db, NULL, DB_RF_CANFAIL | DB_RF_HAVESTRUCT);
1817 if (error) {
1818 dbuf_rele(db, FTAG);
1819 return (error);
1820 }
1821 data = db->db.db_data;
1822 }
1823
1824
1825 if (db != NULL && txg != 0 && (db->db_blkptr == NULL ||
1826 db->db_blkptr->blk_birth <= txg ||
1827 BP_IS_HOLE(db->db_blkptr))) {
1828 /*
1829 * This can only happen when we are searching up the tree
1830 * and these conditions mean that we need to keep climbing.
1831 */
1832 error = SET_ERROR(ESRCH);
1833 } else if (lvl == 0) {
1834 dnode_phys_t *dnp = data;
1835 span = DNODE_SHIFT;
1836 ASSERT(dn->dn_type == DMU_OT_DNODE);
1837
1838 for (i = (*offset >> span) & (blkfill - 1);
1839 i >= 0 && i < blkfill; i += inc) {
1840 if ((dnp[i].dn_type == DMU_OT_NONE) == hole)
1841 break;
1842 *offset += (1ULL << span) * inc;
1843 }
1844 if (i < 0 || i == blkfill)
1845 error = SET_ERROR(ESRCH);
1846 } else {
1847 blkptr_t *bp = data;
1848 uint64_t start = *offset;
1849 span = (lvl - 1) * epbs + dn->dn_datablkshift;
1850 minfill = 0;
1851 maxfill = blkfill << ((lvl - 1) * epbs);
1852
1853 if (hole)
1854 maxfill--;
1855 else
1856 minfill++;
1857
1858 *offset = *offset >> span;
1859 for (i = BF64_GET(*offset, 0, epbs);
1860 i >= 0 && i < epb; i += inc) {
1861 if (BP_GET_FILL(&bp[i]) >= minfill &&
1862 BP_GET_FILL(&bp[i]) <= maxfill &&
1863 (hole || bp[i].blk_birth > txg))
1864 break;
1865 if (inc > 0 || *offset > 0)
1866 *offset += inc;
1867 }
1868 *offset = *offset << span;
1869 if (inc < 0) {
1870 /* traversing backwards; position offset at the end */
1871 ASSERT3U(*offset, <=, start);
1872 *offset = MIN(*offset + (1ULL << span) - 1, start);
1873 } else if (*offset < start) {
1874 *offset = start;
1875 }
1876 if (i < 0 || i >= epb)
1877 error = SET_ERROR(ESRCH);
1878 }
1879
1880 if (db)
1881 dbuf_rele(db, FTAG);
1882
1883 return (error);
1884 }
1885
1886 /*
1887 * Find the next hole, data, or sparse region at or after *offset.
1888 * The value 'blkfill' tells us how many items we expect to find
1889 * in an L0 data block; this value is 1 for normal objects,
1890 * DNODES_PER_BLOCK for the meta dnode, and some fraction of
1891 * DNODES_PER_BLOCK when searching for sparse regions thereof.
1892 *
1893 * Examples:
1894 *
1895 * dnode_next_offset(dn, flags, offset, 1, 1, 0);
1896 * Finds the next/previous hole/data in a file.
1897 * Used in dmu_offset_next().
1898 *
1899 * dnode_next_offset(mdn, flags, offset, 0, DNODES_PER_BLOCK, txg);
1900 * Finds the next free/allocated dnode an objset's meta-dnode.
1901 * Only finds objects that have new contents since txg (ie.
1902 * bonus buffer changes and content removal are ignored).
1903 * Used in dmu_object_next().
1904 *
1905 * dnode_next_offset(mdn, DNODE_FIND_HOLE, offset, 2, DNODES_PER_BLOCK >> 2, 0);
1906 * Finds the next L2 meta-dnode bp that's at most 1/4 full.
1907 * Used in dmu_object_alloc().
1908 */
1909 int
dnode_next_offset(dnode_t * dn,int flags,uint64_t * offset,int minlvl,uint64_t blkfill,uint64_t txg)1910 dnode_next_offset(dnode_t *dn, int flags, uint64_t *offset,
1911 int minlvl, uint64_t blkfill, uint64_t txg)
1912 {
1913 uint64_t initial_offset = *offset;
1914 int lvl, maxlvl;
1915 int error = 0;
1916
1917 if (!(flags & DNODE_FIND_HAVELOCK))
1918 rw_enter(&dn->dn_struct_rwlock, RW_READER);
1919
1920 if (dn->dn_phys->dn_nlevels == 0) {
1921 error = SET_ERROR(ESRCH);
1922 goto out;
1923 }
1924
1925 if (dn->dn_datablkshift == 0) {
1926 if (*offset < dn->dn_datablksz) {
1927 if (flags & DNODE_FIND_HOLE)
1928 *offset = dn->dn_datablksz;
1929 } else {
1930 error = SET_ERROR(ESRCH);
1931 }
1932 goto out;
1933 }
1934
1935 maxlvl = dn->dn_phys->dn_nlevels;
1936
1937 for (lvl = minlvl; lvl <= maxlvl; lvl++) {
1938 error = dnode_next_offset_level(dn,
1939 flags, offset, lvl, blkfill, txg);
1940 if (error != ESRCH)
1941 break;
1942 }
1943
1944 while (error == 0 && --lvl >= minlvl) {
1945 error = dnode_next_offset_level(dn,
1946 flags, offset, lvl, blkfill, txg);
1947 }
1948
1949 /*
1950 * There's always a "virtual hole" at the end of the object, even
1951 * if all BP's which physically exist are non-holes.
1952 */
1953 if ((flags & DNODE_FIND_HOLE) && error == ESRCH && txg == 0 &&
1954 minlvl == 1 && blkfill == 1 && !(flags & DNODE_FIND_BACKWARDS)) {
1955 error = 0;
1956 }
1957
1958 if (error == 0 && (flags & DNODE_FIND_BACKWARDS ?
1959 initial_offset < *offset : initial_offset > *offset))
1960 error = SET_ERROR(ESRCH);
1961 out:
1962 if (!(flags & DNODE_FIND_HAVELOCK))
1963 rw_exit(&dn->dn_struct_rwlock);
1964
1965 return (error);
1966 }
1967