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