sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dnode_sync.c

   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 /*
  23  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
  24  * Copyright (c) 2012, 2016 by Delphix. All rights reserved.
  25  * Copyright (c) 2014 Spectra Logic Corporation, All rights reserved.
  26  */
  27
  28 #include <sys/zfs_context.h>
  29 #include <sys/dbuf.h>
  30 #include <sys/dnode.h>
  31 #include <sys/dmu.h>
  32 #include <sys/dmu_tx.h>
  33 #include <sys/dmu_objset.h>
  34 #include <sys/dsl_dataset.h>
  35 #include <sys/spa.h>
  36 #include <sys/range_tree.h>
  37 #include <sys/zfeature.h>
  38
  39 static void
  40 dnode_increase_indirection(dnode_t *dn, dmu_tx_t *tx)
  41 {
  42         dmu_buf_impl_t *db;
  43         int txgoff = tx->tx_txg & TXG_MASK;
  44         int nblkptr = dn->dn_phys->dn_nblkptr;
  45         int old_toplvl = dn->dn_phys->dn_nlevels - 1;
  46         int new_level = dn->dn_next_nlevels[txgoff];
  47         int i;
  48
  49         rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
  50
  51         /* this dnode can't be paged out because it's dirty */
  52         ASSERT(dn->dn_phys->dn_type != DMU_OT_NONE);
  53         ASSERT(RW_WRITE_HELD(&dn->dn_struct_rwlock));
  54         ASSERT(new_level > 1 && dn->dn_phys->dn_nlevels > 0);
  55
  56         db = dbuf_hold_level(dn, dn->dn_phys->dn_nlevels, 0, FTAG);
  57         ASSERT(db != NULL);
  58
  59         dn->dn_phys->dn_nlevels = new_level;
  60         dprintf("os=%p obj=%llu, increase to %d\n", dn->dn_objset,
  61             dn->dn_object, dn->dn_phys->dn_nlevels);
  62
  63         /* transfer dnode's block pointers to new indirect block */
  64         (void) dbuf_read(db, NULL, DB_RF_MUST_SUCCEED|DB_RF_HAVESTRUCT);
  65         ASSERT(db->db.db_data);
  66         ASSERT(arc_released(db->db_buf));
  67         ASSERT3U(sizeof (blkptr_t) * nblkptr, <=, db->db.db_size);
  68         bcopy(dn->dn_phys->dn_blkptr, db->db.db_data,
  69             sizeof (blkptr_t) * nblkptr);
  70         arc_buf_freeze(db->db_buf);
  71
  72         /* set dbuf's parent pointers to new indirect buf */
  73         for (i = 0; i < nblkptr; i++) {
  74                 dmu_buf_impl_t *child =
  75                     dbuf_find(dn->dn_objset, dn->dn_object, old_toplvl, i);
  76
  77                 if (child == NULL)
  78                         continue;
  79 #ifdef  DEBUG
  80                 DB_DNODE_ENTER(child);
  81                 ASSERT3P(DB_DNODE(child), ==, dn);
  82                 DB_DNODE_EXIT(child);
  83 #endif  /* DEBUG */
  84                 if (child->db_parent && child->db_parent != dn->dn_dbuf) {
  85                         ASSERT(child->db_parent->db_level == db->db_level);
  86                         ASSERT(child->db_blkptr !=
  87                             &dn->dn_phys->dn_blkptr[child->db_blkid]);
  88                         mutex_exit(&child->db_mtx);
  89                         continue;
  90                 }
  91                 ASSERT(child->db_parent == NULL ||
  92                     child->db_parent == dn->dn_dbuf);
  93
  94                 child->db_parent = db;
  95                 dbuf_add_ref(db, child);
  96                 if (db->db.db_data)
  97                         child->db_blkptr = (blkptr_t *)db->db.db_data + i;
  98                 else
  99                         child->db_blkptr = NULL;
 100                 dprintf_dbuf_bp(child, child->db_blkptr,
 101                     "changed db_blkptr to new indirect %s", "");
 102
 103                 mutex_exit(&child->db_mtx);
 104         }
 105
 106         bzero(dn->dn_phys->dn_blkptr, sizeof (blkptr_t) * nblkptr);
 107
 108         dbuf_rele(db, FTAG);
 109
 110         rw_exit(&dn->dn_struct_rwlock);
 111 }
 112
 113 static void
 114 free_blocks(dnode_t *dn, blkptr_t *bp, int num, dmu_tx_t *tx)
 115 {
 116         dsl_dataset_t *ds = dn->dn_objset->os_dsl_dataset;
 117         uint64_t bytesfreed = 0;
 118
 119         dprintf("ds=%p obj=%llx num=%d\n", ds, dn->dn_object, num);
 120
 121         for (int i = 0; i < num; i++, bp++) {
 122                 if (BP_IS_HOLE(bp))
 123                         continue;
 124
 125                 bytesfreed += dsl_dataset_block_kill(ds, bp, tx, B_FALSE);
 126                 ASSERT3U(bytesfreed, <=, DN_USED_BYTES(dn->dn_phys));
 127
 128                 /*
 129                  * Save some useful information on the holes being
 130                  * punched, including logical size, type, and indirection
 131                  * level. Retaining birth time enables detection of when
 132                  * holes are punched for reducing the number of free
 133                  * records transmitted during a zfs send.
 134                  */
 135
 136                 uint64_t lsize = BP_GET_LSIZE(bp);
 137                 dmu_object_type_t type = BP_GET_TYPE(bp);
 138                 uint64_t lvl = BP_GET_LEVEL(bp);
 139
 140                 bzero(bp, sizeof (blkptr_t));
 141
 142                 if (spa_feature_is_active(dn->dn_objset->os_spa,
 143                     SPA_FEATURE_HOLE_BIRTH)) {
 144                         BP_SET_LSIZE(bp, lsize);
 145                         BP_SET_TYPE(bp, type);
 146                         BP_SET_LEVEL(bp, lvl);
 147                         BP_SET_BIRTH(bp, dmu_tx_get_txg(tx), 0);
 148                 }
 149         }
 150         dnode_diduse_space(dn, -bytesfreed);
 151 }
 152
 153 #ifdef ZFS_DEBUG
 154 static void
 155 free_verify(dmu_buf_impl_t *db, uint64_t start, uint64_t end, dmu_tx_t *tx)
 156 {
 157         int off, num;
 158         int i, err, epbs;
 159         uint64_t txg = tx->tx_txg;
 160         dnode_t *dn;
 161
 162         DB_DNODE_ENTER(db);
 163         dn = DB_DNODE(db);
 164         epbs = dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT;
 165         off = start - (db->db_blkid * 1<<epbs);
 166         num = end - start + 1;
 167
 168         ASSERT3U(off, >=, 0);
 169         ASSERT3U(num, >=, 0);
 170         ASSERT3U(db->db_level, >, 0);
 171         ASSERT3U(db->db.db_size, ==, 1 << dn->dn_phys->dn_indblkshift);
 172         ASSERT3U(off+num, <=, db->db.db_size >> SPA_BLKPTRSHIFT);
 173         ASSERT(db->db_blkptr != NULL);
 174
 175         for (i = off; i < off+num; i++) {
 176                 uint64_t *buf;
 177                 dmu_buf_impl_t *child;
 178                 dbuf_dirty_record_t *dr;
 179                 int j;
 180
 181                 ASSERT(db->db_level == 1);
 182
 183                 rw_enter(&dn->dn_struct_rwlock, RW_READER);
 184                 err = dbuf_hold_impl(dn, db->db_level-1,
 185                     (db->db_blkid << epbs) + i, TRUE, FALSE, FTAG, &child);
 186                 rw_exit(&dn->dn_struct_rwlock);
 187                 if (err == ENOENT)
 188                         continue;
 189                 ASSERT(err == 0);
 190                 ASSERT(child->db_level == 0);
 191                 dr = child->db_last_dirty;
 192                 while (dr && dr->dr_txg > txg)
 193                         dr = dr->dr_next;
 194                 ASSERT(dr == NULL || dr->dr_txg == txg);
 195
 196                 /* data_old better be zeroed */
 197                 if (dr) {
 198                         buf = dr->dt.dl.dr_data->b_data;
 199                         for (j = 0; j < child->db.db_size >> 3; j++) {
 200                                 if (buf[j] != 0) {
 201                                         panic("freed data not zero: "
 202                                             "child=%p i=%d off=%d num=%d\n",
 203                                             (void *)child, i, off, num);
 204                                 }
 205                         }
 206                 }
 207
 208                 /*
 209                  * db_data better be zeroed unless it's dirty in a
 210                  * future txg.
 211                  */
 212                 mutex_enter(&child->db_mtx);
 213                 buf = child->db.db_data;
 214                 if (buf != NULL && child->db_state != DB_FILL &&
 215                     child->db_last_dirty == NULL) {
 216                         for (j = 0; j < child->db.db_size >> 3; j++) {
 217                                 if (buf[j] != 0) {
 218                                         panic("freed data not zero: "
 219                                             "child=%p i=%d off=%d num=%d\n",
 220                                             (void *)child, i, off, num);
 221                                 }
 222                         }
 223                 }
 224                 mutex_exit(&child->db_mtx);
 225
 226                 dbuf_rele(child, FTAG);
 227         }
 228         DB_DNODE_EXIT(db);
 229 }
 230 #endif
 231
 232 static void
 233 free_children(dmu_buf_impl_t *db, uint64_t blkid, uint64_t nblks,
 234     dmu_tx_t *tx)
 235 {
 236         dnode_t *dn;
 237         blkptr_t *bp;
 238         dmu_buf_impl_t *subdb;
 239         uint64_t start, end, dbstart, dbend, i;
 240         int epbs, shift;
 241
 242         /*
 243          * There is a small possibility that this block will not be cached:
 244          *   1 - if level > 1 and there are no children with level <= 1
 245          *   2 - if this block was evicted since we read it from
 246          *       dmu_tx_hold_free().
 247          */
 248         if (db->db_state != DB_CACHED)
 249                 (void) dbuf_read(db, NULL, DB_RF_MUST_SUCCEED);
 250
 251         dbuf_release_bp(db);
 252         bp = db->db.db_data;
 253
 254         DB_DNODE_ENTER(db);
 255         dn = DB_DNODE(db);
 256         epbs = dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT;
 257         shift = (db->db_level - 1) * epbs;
 258         dbstart = db->db_blkid << epbs;
 259         start = blkid >> shift;
 260         if (dbstart < start) {
 261                 bp += start - dbstart;
 262         } else {
 263                 start = dbstart;
 264         }
 265         dbend = ((db->db_blkid + 1) << epbs) - 1;
 266         end = (blkid + nblks - 1) >> shift;
 267         if (dbend <= end)
 268                 end = dbend;
 269
 270         ASSERT3U(start, <=, end);
 271
 272         if (db->db_level == 1) {
 273                 FREE_VERIFY(db, start, end, tx);
 274                 free_blocks(dn, bp, end-start+1, tx);
 275         } else {
 276                 for (i = start; i <= end; i++, bp++) {
 277                         if (BP_IS_HOLE(bp))
 278                                 continue;
 279                         rw_enter(&dn->dn_struct_rwlock, RW_READER);
 280                         VERIFY0(dbuf_hold_impl(dn, db->db_level - 1,
 281                             i, TRUE, FALSE, FTAG, &subdb));
 282                         rw_exit(&dn->dn_struct_rwlock);
 283                         ASSERT3P(bp, ==, subdb->db_blkptr);
 284
 285                         free_children(subdb, blkid, nblks, tx);
 286                         dbuf_rele(subdb, FTAG);
 287                 }
 288         }
 289
 290         /* If this whole block is free, free ourself too. */
 291         for (i = 0, bp = db->db.db_data; i < 1 << epbs; i++, bp++) {
 292                 if (!BP_IS_HOLE(bp))
 293                         break;
 294         }
 295         if (i == 1 << epbs) {
 296                 /* didn't find any non-holes */
 297                 bzero(db->db.db_data, db->db.db_size);
 298                 free_blocks(dn, db->db_blkptr, 1, tx);
 299         } else {
 300                 /*
 301                  * Partial block free; must be marked dirty so that it
 302                  * will be written out.
 303                  */
 304                 ASSERT(db->db_dirtycnt > 0);
 305         }
 306
 307         DB_DNODE_EXIT(db);
 308         arc_buf_freeze(db->db_buf);
 309 }
 310
 311 /*
 312  * Traverse the indicated range of the provided file
 313  * and "free" all the blocks contained there.
 314  */
 315 static void
 316 dnode_sync_free_range_impl(dnode_t *dn, uint64_t blkid, uint64_t nblks,
 317     dmu_tx_t *tx)
 318 {
 319         blkptr_t *bp = dn->dn_phys->dn_blkptr;
 320         int dnlevel = dn->dn_phys->dn_nlevels;
 321         boolean_t trunc = B_FALSE;
 322
 323         if (blkid > dn->dn_phys->dn_maxblkid)
 324                 return;
 325
 326         ASSERT(dn->dn_phys->dn_maxblkid < UINT64_MAX);
 327         if (blkid + nblks > dn->dn_phys->dn_maxblkid) {
 328                 nblks = dn->dn_phys->dn_maxblkid - blkid + 1;
 329                 trunc = B_TRUE;
 330         }
 331
 332         /* There are no indirect blocks in the object */
 333         if (dnlevel == 1) {
 334                 if (blkid >= dn->dn_phys->dn_nblkptr) {
 335                         /* this range was never made persistent */
 336                         return;
 337                 }
 338                 ASSERT3U(blkid + nblks, <=, dn->dn_phys->dn_nblkptr);
 339                 free_blocks(dn, bp + blkid, nblks, tx);
 340         } else {
 341                 int shift = (dnlevel - 1) *
 342                     (dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT);
 343                 int start = blkid >> shift;
 344                 int end = (blkid + nblks - 1) >> shift;
 345                 dmu_buf_impl_t *db;
 346
 347                 ASSERT(start < dn->dn_phys->dn_nblkptr);
 348                 bp += start;
 349                 for (int i = start; i <= end; i++, bp++) {
 350                         if (BP_IS_HOLE(bp))
 351                                 continue;
 352                         rw_enter(&dn->dn_struct_rwlock, RW_READER);
 353                         VERIFY0(dbuf_hold_impl(dn, dnlevel - 1, i,
 354                             TRUE, FALSE, FTAG, &db));
 355                         rw_exit(&dn->dn_struct_rwlock);
 356
 357                         free_children(db, blkid, nblks, tx);
 358                         dbuf_rele(db, FTAG);
 359                 }
 360         }
 361
 362         if (trunc) {
 363                 dn->dn_phys->dn_maxblkid = blkid == 0 ? 0 : blkid - 1;
 364
 365                 uint64_t off = (dn->dn_phys->dn_maxblkid + 1) *
 366                     (dn->dn_phys->dn_datablkszsec << SPA_MINBLOCKSHIFT);
 367                 ASSERT(off < dn->dn_phys->dn_maxblkid ||
 368                     dn->dn_phys->dn_maxblkid == 0 ||
 369                     dnode_next_offset(dn, 0, &off, 1, 1, 0) != 0);
 370         }
 371 }
 372
 373 typedef struct dnode_sync_free_range_arg {
 374         dnode_t *dsfra_dnode;
 375         dmu_tx_t *dsfra_tx;
 376 } dnode_sync_free_range_arg_t;
 377
 378 static void
 379 dnode_sync_free_range(void *arg, uint64_t blkid, uint64_t nblks)
 380 {
 381         dnode_sync_free_range_arg_t *dsfra = arg;
 382         dnode_t *dn = dsfra->dsfra_dnode;
 383
 384         mutex_exit(&dn->dn_mtx);
 385         dnode_sync_free_range_impl(dn, blkid, nblks, dsfra->dsfra_tx);
 386         mutex_enter(&dn->dn_mtx);
 387 }
 388
 389 /*
 390  * Try to kick all the dnode's dbufs out of the cache...
 391  */
 392 void
 393 dnode_evict_dbufs(dnode_t *dn)
 394 {
 395         dmu_buf_impl_t db_marker;
 396         dmu_buf_impl_t *db, *db_next;
 397
 398         mutex_enter(&dn->dn_dbufs_mtx);
 399         for (db = avl_first(&dn->dn_dbufs); db != NULL; db = db_next) {
 400
 401 #ifdef  DEBUG
 402                 DB_DNODE_ENTER(db);
 403                 ASSERT3P(DB_DNODE(db), ==, dn);
 404                 DB_DNODE_EXIT(db);
 405 #endif  /* DEBUG */
 406
 407                 mutex_enter(&db->db_mtx);
 408                 if (db->db_state != DB_EVICTING &&
 409                     refcount_is_zero(&db->db_holds)) {
 410                         db_marker.db_level = db->db_level;
 411                         db_marker.db_blkid = db->db_blkid;
 412                         db_marker.db_state = DB_SEARCH;
 413                         avl_insert_here(&dn->dn_dbufs, &db_marker, db,
 414                             AVL_BEFORE);
 415
 416                         dbuf_destroy(db);
 417
 418                         db_next = AVL_NEXT(&dn->dn_dbufs, &db_marker);
 419                         avl_remove(&dn->dn_dbufs, &db_marker);
 420                 } else {
 421                         db->db_pending_evict = TRUE;
 422                         mutex_exit(&db->db_mtx);
 423                         db_next = AVL_NEXT(&dn->dn_dbufs, db);
 424                 }
 425         }
 426         mutex_exit(&dn->dn_dbufs_mtx);
 427
 428         dnode_evict_bonus(dn);
 429 }
 430
 431 void
 432 dnode_evict_bonus(dnode_t *dn)
 433 {
 434         rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
 435         if (dn->dn_bonus != NULL) {
 436                 if (refcount_is_zero(&dn->dn_bonus->db_holds)) {
 437                         mutex_enter(&dn->dn_bonus->db_mtx);
 438                         dbuf_destroy(dn->dn_bonus);
 439                         dn->dn_bonus = NULL;
 440                 } else {
 441                         dn->dn_bonus->db_pending_evict = TRUE;
 442                 }
 443         }
 444         rw_exit(&dn->dn_struct_rwlock);
 445 }
 446
 447 static void
 448 dnode_undirty_dbufs(list_t *list)
 449 {
 450         dbuf_dirty_record_t *dr;
 451
 452         while (dr = list_head(list)) {
 453                 dmu_buf_impl_t *db = dr->dr_dbuf;
 454                 uint64_t txg = dr->dr_txg;
 455
 456                 if (db->db_level != 0)
 457                         dnode_undirty_dbufs(&dr->dt.di.dr_children);
 458
 459                 mutex_enter(&db->db_mtx);
 460                 /* XXX - use dbuf_undirty()? */
 461                 list_remove(list, dr);
 462                 ASSERT(db->db_last_dirty == dr);
 463                 db->db_last_dirty = NULL;
 464                 db->db_dirtycnt -= 1;
 465                 if (db->db_level == 0) {
 466                         ASSERT(db->db_blkid == DMU_BONUS_BLKID ||
 467                             dr->dt.dl.dr_data == db->db_buf);
 468                         dbuf_unoverride(dr);
 469                 } else {
 470                         mutex_destroy(&dr->dt.di.dr_mtx);
 471                         list_destroy(&dr->dt.di.dr_children);
 472                 }
 473                 kmem_free(dr, sizeof (dbuf_dirty_record_t));
 474                 dbuf_rele_and_unlock(db, (void *)(uintptr_t)txg);
 475         }
 476 }
 477
 478 static void
 479 dnode_sync_free(dnode_t *dn, dmu_tx_t *tx)
 480 {
 481         int txgoff = tx->tx_txg & TXG_MASK;
 482
 483         ASSERT(dmu_tx_is_syncing(tx));
 484
 485         /*
 486          * Our contents should have been freed in dnode_sync() by the
 487          * free range record inserted by the caller of dnode_free().
 488          */
 489         ASSERT0(DN_USED_BYTES(dn->dn_phys));
 490         ASSERT(BP_IS_HOLE(dn->dn_phys->dn_blkptr));
 491
 492         dnode_undirty_dbufs(&dn->dn_dirty_records[txgoff]);
 493         dnode_evict_dbufs(dn);
 494
 495         /*
 496          * XXX - It would be nice to assert this, but we may still
 497          * have residual holds from async evictions from the arc...
 498          *
 499          * zfs_obj_to_path() also depends on this being
 500          * commented out.
 501          *
 502          * ASSERT3U(refcount_count(&dn->dn_holds), ==, 1);
 503          */
 504
 505         /* Undirty next bits */
 506         dn->dn_next_nlevels[txgoff] = 0;
 507         dn->dn_next_indblkshift[txgoff] = 0;
 508         dn->dn_next_blksz[txgoff] = 0;
 509
 510         /* ASSERT(blkptrs are zero); */
 511         ASSERT(dn->dn_phys->dn_type != DMU_OT_NONE);
 512         ASSERT(dn->dn_type != DMU_OT_NONE);
 513
 514         ASSERT(dn->dn_free_txg > 0);
 515         if (dn->dn_allocated_txg != dn->dn_free_txg)
 516                 dmu_buf_will_dirty(&dn->dn_dbuf->db, tx);
 517         bzero(dn->dn_phys, sizeof (dnode_phys_t));
 518
 519         mutex_enter(&dn->dn_mtx);
 520         dn->dn_type = DMU_OT_NONE;
 521         dn->dn_maxblkid = 0;
 522         dn->dn_allocated_txg = 0;
 523         dn->dn_free_txg = 0;
 524         dn->dn_have_spill = B_FALSE;
 525         mutex_exit(&dn->dn_mtx);
 526
 527         ASSERT(dn->dn_object != DMU_META_DNODE_OBJECT);
 528
 529         dnode_rele(dn, (void *)(uintptr_t)tx->tx_txg);
 530         /*
 531          * Now that we've released our hold, the dnode may
 532          * be evicted, so we musn't access it.
 533          */
 534 }
 535
 536 /*
 537  * Write out the dnode's dirty buffers.
 538  */
 539 void
 540 dnode_sync(dnode_t *dn, dmu_tx_t *tx)
 541 {
 542         dnode_phys_t *dnp = dn->dn_phys;
 543         int txgoff = tx->tx_txg & TXG_MASK;
 544         list_t *list = &dn->dn_dirty_records[txgoff];
 545         static const dnode_phys_t zerodn = { 0 };
 546         boolean_t kill_spill = B_FALSE;
 547
 548         ASSERT(dmu_tx_is_syncing(tx));
 549         ASSERT(dnp->dn_type != DMU_OT_NONE || dn->dn_allocated_txg);
 550         ASSERT(dnp->dn_type != DMU_OT_NONE ||
 551             bcmp(dnp, &zerodn, DNODE_SIZE) == 0);
 552         DNODE_VERIFY(dn);
 553
 554         ASSERT(dn->dn_dbuf == NULL || arc_released(dn->dn_dbuf->db_buf));
 555
 556         if (dmu_objset_userused_enabled(dn->dn_objset) &&
 557             !DMU_OBJECT_IS_SPECIAL(dn->dn_object)) {
 558                 mutex_enter(&dn->dn_mtx);
 559                 dn->dn_oldused = DN_USED_BYTES(dn->dn_phys);
 560                 dn->dn_oldflags = dn->dn_phys->dn_flags;
 561                 dn->dn_phys->dn_flags |= DNODE_FLAG_USERUSED_ACCOUNTED;
 562                 mutex_exit(&dn->dn_mtx);
 563                 dmu_objset_userquota_get_ids(dn, B_FALSE, tx);
 564         } else {
 565                 /* Once we account for it, we should always account for it. */
 566                 ASSERT(!(dn->dn_phys->dn_flags &
 567                     DNODE_FLAG_USERUSED_ACCOUNTED));
 568         }
 569
 570         mutex_enter(&dn->dn_mtx);
 571         if (dn->dn_allocated_txg == tx->tx_txg) {
 572                 /* The dnode is newly allocated or reallocated */
 573                 if (dnp->dn_type == DMU_OT_NONE) {
 574                         /* this is a first alloc, not a realloc */
 575                         dnp->dn_nlevels = 1;
 576                         dnp->dn_nblkptr = dn->dn_nblkptr;
 577                 }
 578
 579                 dnp->dn_type = dn->dn_type;
 580                 dnp->dn_bonustype = dn->dn_bonustype;
 581                 dnp->dn_bonuslen = dn->dn_bonuslen;
 582         }
 583         ASSERT(dnp->dn_nlevels > 1 ||
 584             BP_IS_HOLE(&dnp->dn_blkptr[0]) ||
 585             BP_IS_EMBEDDED(&dnp->dn_blkptr[0]) ||
 586             BP_GET_LSIZE(&dnp->dn_blkptr[0]) ==
 587             dnp->dn_datablkszsec << SPA_MINBLOCKSHIFT);
 588         ASSERT(dnp->dn_nlevels < 2 ||
 589             BP_IS_HOLE(&dnp->dn_blkptr[0]) ||
 590             BP_GET_LSIZE(&dnp->dn_blkptr[0]) == 1 << dnp->dn_indblkshift);
 591
 592         if (dn->dn_next_type[txgoff] != 0) {
 593                 dnp->dn_type = dn->dn_type;
 594                 dn->dn_next_type[txgoff] = 0;
 595         }
 596
 597         if (dn->dn_next_blksz[txgoff] != 0) {
 598                 ASSERT(P2PHASE(dn->dn_next_blksz[txgoff],
 599                     SPA_MINBLOCKSIZE) == 0);
 600                 ASSERT(BP_IS_HOLE(&dnp->dn_blkptr[0]) ||
 601                     dn->dn_maxblkid == 0 || list_head(list) != NULL ||
 602                     dn->dn_next_blksz[txgoff] >> SPA_MINBLOCKSHIFT ==
 603                     dnp->dn_datablkszsec ||
 604                     range_tree_space(dn->dn_free_ranges[txgoff]) != 0);
 605                 dnp->dn_datablkszsec =
 606                     dn->dn_next_blksz[txgoff] >> SPA_MINBLOCKSHIFT;
 607                 dn->dn_next_blksz[txgoff] = 0;
 608         }
 609
 610         if (dn->dn_next_bonuslen[txgoff] != 0) {
 611                 if (dn->dn_next_bonuslen[txgoff] == DN_ZERO_BONUSLEN)
 612                         dnp->dn_bonuslen = 0;
 613                 else
 614                         dnp->dn_bonuslen = dn->dn_next_bonuslen[txgoff];
 615                 ASSERT(dnp->dn_bonuslen <= DN_MAX_BONUSLEN);
 616                 dn->dn_next_bonuslen[txgoff] = 0;
 617         }
 618
 619         if (dn->dn_next_bonustype[txgoff] != 0) {
 620                 ASSERT(DMU_OT_IS_VALID(dn->dn_next_bonustype[txgoff]));
 621                 dnp->dn_bonustype = dn->dn_next_bonustype[txgoff];
 622                 dn->dn_next_bonustype[txgoff] = 0;
 623         }
 624
 625         boolean_t freeing_dnode = dn->dn_free_txg > 0 &&
 626             dn->dn_free_txg <= tx->tx_txg;
 627
 628         /*
 629          * Remove the spill block if we have been explicitly asked to
 630          * remove it, or if the object is being removed.
 631          */
 632         if (dn->dn_rm_spillblk[txgoff] || freeing_dnode) {
 633                 if (dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR)
 634                         kill_spill = B_TRUE;
 635                 dn->dn_rm_spillblk[txgoff] = 0;
 636         }
 637
 638         if (dn->dn_next_indblkshift[txgoff] != 0) {
 639                 ASSERT(dnp->dn_nlevels == 1);
 640                 dnp->dn_indblkshift = dn->dn_next_indblkshift[txgoff];
 641                 dn->dn_next_indblkshift[txgoff] = 0;
 642         }
 643
 644         /*
 645          * Just take the live (open-context) values for checksum and compress.
 646          * Strictly speaking it's a future leak, but nothing bad happens if we
 647          * start using the new checksum or compress algorithm a little early.
 648          */
 649         dnp->dn_checksum = dn->dn_checksum;
 650         dnp->dn_compress = dn->dn_compress;
 651
 652         mutex_exit(&dn->dn_mtx);
 653
 654         if (kill_spill) {
 655                 free_blocks(dn, &dn->dn_phys->dn_spill, 1, tx);
 656                 mutex_enter(&dn->dn_mtx);
 657                 dnp->dn_flags &= ~DNODE_FLAG_SPILL_BLKPTR;
 658                 mutex_exit(&dn->dn_mtx);
 659         }
 660
 661         /* process all the "freed" ranges in the file */
 662         if (dn->dn_free_ranges[txgoff] != NULL) {
 663                 dnode_sync_free_range_arg_t dsfra;
 664                 dsfra.dsfra_dnode = dn;
 665                 dsfra.dsfra_tx = tx;
 666                 mutex_enter(&dn->dn_mtx);
 667                 range_tree_vacate(dn->dn_free_ranges[txgoff],
 668                     dnode_sync_free_range, &dsfra);
 669                 range_tree_destroy(dn->dn_free_ranges[txgoff]);
 670                 dn->dn_free_ranges[txgoff] = NULL;
 671                 mutex_exit(&dn->dn_mtx);
 672         }
 673
 674         if (freeing_dnode) {
 675                 dnode_sync_free(dn, tx);
 676                 return;
 677         }
 678
 679         if (dn->dn_next_nlevels[txgoff]) {
 680                 dnode_increase_indirection(dn, tx);
 681                 dn->dn_next_nlevels[txgoff] = 0;
 682         }
 683
 684         if (dn->dn_next_nblkptr[txgoff]) {
 685                 /* this should only happen on a realloc */
 686                 ASSERT(dn->dn_allocated_txg == tx->tx_txg);
 687                 if (dn->dn_next_nblkptr[txgoff] > dnp->dn_nblkptr) {
 688                         /* zero the new blkptrs we are gaining */
 689                         bzero(dnp->dn_blkptr + dnp->dn_nblkptr,
 690                             sizeof (blkptr_t) *
 691                             (dn->dn_next_nblkptr[txgoff] - dnp->dn_nblkptr));
 692 #ifdef ZFS_DEBUG
 693                 } else {
 694                         int i;
 695                         ASSERT(dn->dn_next_nblkptr[txgoff] < dnp->dn_nblkptr);
 696                         /* the blkptrs we are losing better be unallocated */
 697                         for (i = dn->dn_next_nblkptr[txgoff];
 698                             i < dnp->dn_nblkptr; i++)
 699                                 ASSERT(BP_IS_HOLE(&dnp->dn_blkptr[i]));
 700 #endif
 701                 }
 702                 mutex_enter(&dn->dn_mtx);
 703                 dnp->dn_nblkptr = dn->dn_next_nblkptr[txgoff];
 704                 dn->dn_next_nblkptr[txgoff] = 0;
 705                 mutex_exit(&dn->dn_mtx);
 706         }
 707
 708         dbuf_sync_list(list, dn->dn_phys->dn_nlevels - 1, tx);
 709
 710         if (!DMU_OBJECT_IS_SPECIAL(dn->dn_object)) {
 711                 ASSERT3P(list_head(list), ==, NULL);
 712                 dnode_rele(dn, (void *)(uintptr_t)tx->tx_txg);
 713         }
 714
 715         /*
 716          * Although we have dropped our reference to the dnode, it
 717          * can't be evicted until its written, and we haven't yet
 718          * initiated the IO for the dnode's dbuf.
 719          */
 720 }