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) 2013 by Delphix. All rights reserved.
  25  */
  26
  27 #include <sys/zfs_context.h>
  28 #include <sys/dbuf.h>
  29 #include <sys/dnode.h>
  30 #include <sys/dmu.h>
  31 #include <sys/dmu_tx.h>
  32 #include <sys/dmu_objset.h>
  33 #include <sys/dsl_dataset.h>
  34 #include <sys/spa.h>
  35 #include <sys/zfeature.h>
  36
  37 static void
  38 dnode_increase_indirection(dnode_t *dn, dmu_tx_t *tx)
  39 {
  40         dmu_buf_impl_t *db;
  41         int txgoff = tx->tx_txg & TXG_MASK;
  42         int nblkptr = dn->dn_phys->dn_nblkptr;
  43         int old_toplvl = dn->dn_phys->dn_nlevels - 1;
  44         int new_level = dn->dn_next_nlevels[txgoff];
  45         int i;
  46
  47         rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
  48
  49         /* this dnode can't be paged out because it's dirty */
  50         ASSERT(dn->dn_phys->dn_type != DMU_OT_NONE);
  51         ASSERT(RW_WRITE_HELD(&dn->dn_struct_rwlock));
  52         ASSERT(new_level > 1 && dn->dn_phys->dn_nlevels > 0);
  53
  54         db = dbuf_hold_level(dn, dn->dn_phys->dn_nlevels, 0, FTAG);
  55         ASSERT(db != NULL);
  56
  57         dn->dn_phys->dn_nlevels = new_level;
  58         dprintf("os=%p obj=%llu, increase to %d\n", dn->dn_objset,
  59             dn->dn_object, dn->dn_phys->dn_nlevels);
  60
  61         /* check for existing blkptrs in the dnode */
  62         for (i = 0; i < nblkptr; i++)
  63                 if (!BP_IS_HOLE(&dn->dn_phys->dn_blkptr[i]))
  64                         break;
  65         if (i != nblkptr) {
  66                 /* transfer dnode's block pointers to new indirect block */
  67                 (void) dbuf_read(db, NULL, DB_RF_MUST_SUCCEED|DB_RF_HAVESTRUCT);
  68                 ASSERT(db->db.db_data);
  69                 ASSERT(arc_released(db->db_buf));
  70                 ASSERT3U(sizeof (blkptr_t) * nblkptr, <=, db->db.db_size);
  71                 bcopy(dn->dn_phys->dn_blkptr, db->db.db_data,
  72                     sizeof (blkptr_t) * nblkptr);
  73                 arc_buf_freeze(db->db_buf);
  74         }
  75
  76         /* set dbuf's parent pointers to new indirect buf */
  77         for (i = 0; i < nblkptr; i++) {
  78                 dmu_buf_impl_t *child = dbuf_find(dn, old_toplvl, i);
  79
  80                 if (child == NULL)
  81                         continue;
  82 #ifdef  DEBUG
  83                 DB_DNODE_ENTER(child);
  84                 ASSERT3P(DB_DNODE(child), ==, dn);
  85                 DB_DNODE_EXIT(child);
  86 #endif  /* DEBUG */
  87                 if (child->db_parent && child->db_parent != dn->dn_dbuf) {
  88                         ASSERT(child->db_parent->db_level == db->db_level);
  89                         ASSERT(child->db_blkptr !=
  90                             &dn->dn_phys->dn_blkptr[child->db_blkid]);
  91                         mutex_exit(&child->db_mtx);
  92                         continue;
  93                 }
  94                 ASSERT(child->db_parent == NULL ||
  95                     child->db_parent == dn->dn_dbuf);
  96
  97                 child->db_parent = db;
  98                 dbuf_add_ref(db, child);
  99                 if (db->db.db_data)
 100                         child->db_blkptr = (blkptr_t *)db->db.db_data + i;
 101                 else
 102                         child->db_blkptr = NULL;
 103                 dprintf_dbuf_bp(child, child->db_blkptr,
 104                     "changed db_blkptr to new indirect %s", "");
 105
 106                 mutex_exit(&child->db_mtx);
 107         }
 108
 109         bzero(dn->dn_phys->dn_blkptr, sizeof (blkptr_t) * nblkptr);
 110
 111         dbuf_rele(db, FTAG);
 112
 113         rw_exit(&dn->dn_struct_rwlock);
 114 }
 115
 116 static void
 117 free_blocks(dnode_t *dn, blkptr_t *bp, int num, dmu_tx_t *tx)
 118 {
 119         dsl_dataset_t *ds = dn->dn_objset->os_dsl_dataset;
 120         uint64_t bytesfreed = 0;
 121
 122         dprintf("ds=%p obj=%llx num=%d\n", ds, dn->dn_object, num);
 123
 124         for (int i = 0; i < num; i++, bp++) {
 125                 if (BP_IS_HOLE(bp))
 126                         continue;
 127
 128                 bytesfreed += dsl_dataset_block_kill(ds, bp, tx, B_FALSE);
 129                 ASSERT3U(bytesfreed, <=, DN_USED_BYTES(dn->dn_phys));
 130
 131                 /*
 132                  * Save some useful information on the holes being
 133                  * punched, including logical size, type, and indirection
 134                  * level. Retaining birth time enables detection of when
 135                  * holes are punched for reducing the number of free
 136                  * records transmitted during a zfs send.
 137                  */
 138
 139                 uint64_t lsize = BP_GET_LSIZE(bp);
 140                 dmu_object_type_t type = BP_GET_TYPE(bp);
 141                 uint64_t lvl = BP_GET_LEVEL(bp);
 142
 143                 bzero(bp, sizeof (blkptr_t));
 144
 145                 if (spa_feature_is_active(dn->dn_objset->os_spa,
 146                     SPA_FEATURE_HOLE_BIRTH)) {
 147                         BP_SET_LSIZE(bp, lsize);
 148                         BP_SET_TYPE(bp, type);
 149                         BP_SET_LEVEL(bp, lvl);
 150                         BP_SET_BIRTH(bp, dmu_tx_get_txg(tx), 0);
 151                 }
 152         }
 153         dnode_diduse_space(dn, -bytesfreed);
 154 }
 155
 156 #ifdef ZFS_DEBUG
 157 static void
 158 free_verify(dmu_buf_impl_t *db, uint64_t start, uint64_t end, dmu_tx_t *tx)
 159 {
 160         int off, num;
 161         int i, err, epbs;
 162         uint64_t txg = tx->tx_txg;
 163         dnode_t *dn;
 164
 165         DB_DNODE_ENTER(db);
 166         dn = DB_DNODE(db);
 167         epbs = dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT;
 168         off = start - (db->db_blkid * 1<<epbs);
 169         num = end - start + 1;
 170
 171         ASSERT3U(off, >=, 0);
 172         ASSERT3U(num, >=, 0);
 173         ASSERT3U(db->db_level, >, 0);
 174         ASSERT3U(db->db.db_size, ==, 1 << dn->dn_phys->dn_indblkshift);
 175         ASSERT3U(off+num, <=, db->db.db_size >> SPA_BLKPTRSHIFT);
 176         ASSERT(db->db_blkptr != NULL);
 177
 178         for (i = off; i < off+num; i++) {
 179                 uint64_t *buf;
 180                 dmu_buf_impl_t *child;
 181                 dbuf_dirty_record_t *dr;
 182                 int j;
 183
 184                 ASSERT(db->db_level == 1);
 185
 186                 rw_enter(&dn->dn_struct_rwlock, RW_READER);
 187                 err = dbuf_hold_impl(dn, db->db_level-1,
 188                     (db->db_blkid << epbs) + i, TRUE, FTAG, &child);
 189                 rw_exit(&dn->dn_struct_rwlock);
 190                 if (err == ENOENT)
 191                         continue;
 192                 ASSERT(err == 0);
 193                 ASSERT(child->db_level == 0);
 194                 dr = child->db_last_dirty;
 195                 while (dr && dr->dr_txg > txg)
 196                         dr = dr->dr_next;
 197                 ASSERT(dr == NULL || dr->dr_txg == txg);
 198
 199                 /* data_old better be zeroed */
 200                 if (dr) {
 201                         buf = dr->dt.dl.dr_data->b_data;
 202                         for (j = 0; j < child->db.db_size >> 3; j++) {
 203                                 if (buf[j] != 0) {
 204                                         panic("freed data not zero: "
 205                                             "child=%p i=%d off=%d num=%d\n",
 206                                             (void *)child, i, off, num);
 207                                 }
 208                         }
 209                 }
 210
 211                 /*
 212                  * db_data better be zeroed unless it's dirty in a
 213                  * future txg.
 214                  */
 215                 mutex_enter(&child->db_mtx);
 216                 buf = child->db.db_data;
 217                 if (buf != NULL && child->db_state != DB_FILL &&
 218                     child->db_last_dirty == NULL) {
 219                         for (j = 0; j < child->db.db_size >> 3; j++) {
 220                                 if (buf[j] != 0) {
 221                                         panic("freed data not zero: "
 222                                             "child=%p i=%d off=%d num=%d\n",
 223                                             (void *)child, i, off, num);
 224                                 }
 225                         }
 226                 }
 227                 mutex_exit(&child->db_mtx);
 228
 229                 dbuf_rele(child, FTAG);
 230         }
 231         DB_DNODE_EXIT(db);
 232 }
 233 #endif
 234
 235 #define ALL -1
 236
 237 static void
 238 free_children(dmu_buf_impl_t *db, uint64_t blkid, uint64_t nblks,
 239     dmu_tx_t *tx)
 240 {
 241         dnode_t *dn;
 242         blkptr_t *bp;
 243         dmu_buf_impl_t *subdb;
 244         uint64_t start, end, dbstart, dbend, i;
 245         int epbs, shift;
 246
 247         /*
 248          * There is a small possibility that this block will not be cached:
 249          *   1 - if level > 1 and there are no children with level <= 1
 250          *   2 - if this block was evicted since we read it from
 251          *       dmu_tx_hold_free().
 252          */
 253         if (db->db_state != DB_CACHED)
 254                 (void) dbuf_read(db, NULL, DB_RF_MUST_SUCCEED);
 255
 256         dbuf_release_bp(db);
 257         bp = db->db.db_data;
 258
 259         DB_DNODE_ENTER(db);
 260         dn = DB_DNODE(db);
 261         epbs = dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT;
 262         shift = (db->db_level - 1) * epbs;
 263         dbstart = db->db_blkid << epbs;
 264         start = blkid >> shift;
 265         if (dbstart < start) {
 266                 bp += start - dbstart;
 267         } else {
 268                 start = dbstart;
 269         }
 270         dbend = ((db->db_blkid + 1) << epbs) - 1;
 271         end = (blkid + nblks - 1) >> shift;
 272         if (dbend <= end)
 273                 end = dbend;
 274
 275         ASSERT3U(start, <=, end);
 276
 277         if (db->db_level == 1) {
 278                 FREE_VERIFY(db, start, end, tx);
 279                 free_blocks(dn, bp, end-start+1, tx);
 280         } else {
 281                 for (i = start; i <= end; i++, bp++) {
 282                         if (BP_IS_HOLE(bp))
 283                                 continue;
 284                         rw_enter(&dn->dn_struct_rwlock, RW_READER);
 285                         VERIFY0(dbuf_hold_impl(dn, db->db_level - 1,
 286                             i, B_TRUE, FTAG, &subdb));
 287                         rw_exit(&dn->dn_struct_rwlock);
 288                         ASSERT3P(bp, ==, subdb->db_blkptr);
 289
 290                         free_children(subdb, blkid, nblks, tx);
 291                         dbuf_rele(subdb, FTAG);
 292                 }
 293         }
 294
 295         /* If this whole block is free, free ourself too. */
 296         for (i = 0, bp = db->db.db_data; i < 1 << epbs; i++, bp++) {
 297                 if (!BP_IS_HOLE(bp))
 298                         break;
 299         }
 300         if (i == 1 << epbs) {
 301                 /* didn't find any non-holes */
 302                 bzero(db->db.db_data, db->db.db_size);
 303                 free_blocks(dn, db->db_blkptr, 1, tx);
 304         } else {
 305                 /*
 306                  * Partial block free; must be marked dirty so that it
 307                  * will be written out.
 308                  */
 309                 ASSERT(db->db_dirtycnt > 0);
 310         }
 311
 312         DB_DNODE_EXIT(db);
 313         arc_buf_freeze(db->db_buf);
 314 }
 315
 316 /*
 317  * Traverse the indicated range of the provided file
 318  * and "free" all the blocks contained there.
 319  */
 320 static void
 321 dnode_sync_free_range(dnode_t *dn, uint64_t blkid, uint64_t nblks,
 322     dmu_tx_t *tx)
 323 {
 324         blkptr_t *bp = dn->dn_phys->dn_blkptr;
 325         int dnlevel = dn->dn_phys->dn_nlevels;
 326         boolean_t trunc = B_FALSE;
 327
 328         if (blkid > dn->dn_phys->dn_maxblkid)
 329                 return;
 330
 331         ASSERT(dn->dn_phys->dn_maxblkid < UINT64_MAX);
 332         if (blkid + nblks > dn->dn_phys->dn_maxblkid) {
 333                 nblks = dn->dn_phys->dn_maxblkid - blkid + 1;
 334                 trunc = B_TRUE;
 335         }
 336
 337         /* There are no indirect blocks in the object */
 338         if (dnlevel == 1) {
 339                 if (blkid >= dn->dn_phys->dn_nblkptr) {
 340                         /* this range was never made persistent */
 341                         return;
 342                 }
 343                 ASSERT3U(blkid + nblks, <=, dn->dn_phys->dn_nblkptr);
 344                 free_blocks(dn, bp + blkid, nblks, tx);
 345         } else {
 346                 int shift = (dnlevel - 1) *
 347                     (dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT);
 348                 int start = blkid >> shift;
 349                 int end = (blkid + nblks - 1) >> shift;
 350                 dmu_buf_impl_t *db;
 351
 352                 ASSERT(start < dn->dn_phys->dn_nblkptr);
 353                 bp += start;
 354                 for (int i = start; i <= end; i++, bp++) {
 355                         if (BP_IS_HOLE(bp))
 356                                 continue;
 357                         rw_enter(&dn->dn_struct_rwlock, RW_READER);
 358                         VERIFY0(dbuf_hold_impl(dn, dnlevel - 1, i,
 359                             TRUE, FTAG, &db));
 360                         rw_exit(&dn->dn_struct_rwlock);
 361
 362                         free_children(db, blkid, nblks, tx);
 363                         dbuf_rele(db, FTAG);
 364
 365                 }
 366         }
 367
 368         if (trunc) {
 369                 dn->dn_phys->dn_maxblkid = blkid == 0 ? 0 : blkid - 1;
 370
 371                 uint64_t off = (dn->dn_phys->dn_maxblkid + 1) *
 372                     (dn->dn_phys->dn_datablkszsec << SPA_MINBLOCKSHIFT);
 373                 ASSERT(off < dn->dn_phys->dn_maxblkid ||
 374                     dn->dn_phys->dn_maxblkid == 0 ||
 375                     dnode_next_offset(dn, 0, &off, 1, 1, 0) != 0);
 376         }
 377 }
 378
 379 /*
 380  * Try to kick all the dnode's dbufs out of the cache...
 381  */
 382 void
 383 dnode_evict_dbufs(dnode_t *dn)
 384 {
 385         int progress;
 386         int pass = 0;
 387
 388         do {
 389                 dmu_buf_impl_t *db, marker;
 390                 int evicting = FALSE;
 391
 392                 progress = FALSE;
 393                 mutex_enter(&dn->dn_dbufs_mtx);
 394                 list_insert_tail(&dn->dn_dbufs, &marker);
 395                 db = list_head(&dn->dn_dbufs);
 396                 for (; db != &marker; db = list_head(&dn->dn_dbufs)) {
 397                         list_remove(&dn->dn_dbufs, db);
 398                         list_insert_tail(&dn->dn_dbufs, db);
 399 #ifdef  DEBUG
 400                         DB_DNODE_ENTER(db);
 401                         ASSERT3P(DB_DNODE(db), ==, dn);
 402                         DB_DNODE_EXIT(db);
 403 #endif  /* DEBUG */
 404
 405                         mutex_enter(&db->db_mtx);
 406                         if (db->db_state == DB_EVICTING) {
 407                                 progress = TRUE;
 408                                 evicting = TRUE;
 409                                 mutex_exit(&db->db_mtx);
 410                         } else if (refcount_is_zero(&db->db_holds)) {
 411                                 progress = TRUE;
 412                                 dbuf_clear(db); /* exits db_mtx for us */
 413                         } else {
 414                                 mutex_exit(&db->db_mtx);
 415                         }
 416
 417                 }
 418                 list_remove(&dn->dn_dbufs, &marker);
 419                 /*
 420                  * NB: we need to drop dn_dbufs_mtx between passes so
 421                  * that any DB_EVICTING dbufs can make progress.
 422                  * Ideally, we would have some cv we could wait on, but
 423                  * since we don't, just wait a bit to give the other
 424                  * thread a chance to run.
 425                  */
 426                 mutex_exit(&dn->dn_dbufs_mtx);
 427                 if (evicting)
 428                         delay(1);
 429                 pass++;
 430                 ASSERT(pass < 100); /* sanity check */
 431         } while (progress);
 432
 433         rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
 434         if (dn->dn_bonus && refcount_is_zero(&dn->dn_bonus->db_holds)) {
 435                 mutex_enter(&dn->dn_bonus->db_mtx);
 436                 dbuf_evict(dn->dn_bonus);
 437                 dn->dn_bonus = NULL;
 438         }
 439         rw_exit(&dn->dn_struct_rwlock);
 440 }
 441
 442 static void
 443 dnode_undirty_dbufs(list_t *list)
 444 {
 445         dbuf_dirty_record_t *dr;
 446
 447         while (dr = list_head(list)) {
 448                 dmu_buf_impl_t *db = dr->dr_dbuf;
 449                 uint64_t txg = dr->dr_txg;
 450
 451                 if (db->db_level != 0)
 452                         dnode_undirty_dbufs(&dr->dt.di.dr_children);
 453
 454                 mutex_enter(&db->db_mtx);
 455                 /* XXX - use dbuf_undirty()? */
 456                 list_remove(list, dr);
 457                 ASSERT(db->db_last_dirty == dr);
 458                 db->db_last_dirty = NULL;
 459                 db->db_dirtycnt -= 1;
 460                 if (db->db_level == 0) {
 461                         ASSERT(db->db_blkid == DMU_BONUS_BLKID ||
 462                             dr->dt.dl.dr_data == db->db_buf);
 463                         dbuf_unoverride(dr);
 464                 } else {
 465                         list_destroy(&dr->dt.di.dr_children);
 466                         mutex_destroy(&dr->dt.di.dr_mtx);
 467                 }
 468                 kmem_free(dr, sizeof (dbuf_dirty_record_t));
 469                 dbuf_rele_and_unlock(db, (void *)(uintptr_t)txg);
 470         }
 471 }
 472
 473 static void
 474 dnode_sync_free(dnode_t *dn, dmu_tx_t *tx)
 475 {
 476         int txgoff = tx->tx_txg & TXG_MASK;
 477
 478         ASSERT(dmu_tx_is_syncing(tx));
 479
 480         /*
 481          * Our contents should have been freed in dnode_sync() by the
 482          * free range record inserted by the caller of dnode_free().
 483          */
 484         ASSERT0(DN_USED_BYTES(dn->dn_phys));
 485         ASSERT(BP_IS_HOLE(dn->dn_phys->dn_blkptr));
 486
 487         dnode_undirty_dbufs(&dn->dn_dirty_records[txgoff]);
 488         dnode_evict_dbufs(dn);
 489         ASSERT3P(list_head(&dn->dn_dbufs), ==, NULL);
 490         ASSERT3P(dn->dn_bonus, ==, NULL);
 491
 492         /*
 493          * XXX - It would be nice to assert this, but we may still
 494          * have residual holds from async evictions from the arc...
 495          *
 496          * zfs_obj_to_path() also depends on this being
 497          * commented out.
 498          *
 499          * ASSERT3U(refcount_count(&dn->dn_holds), ==, 1);
 500          */
 501
 502         /* Undirty next bits */
 503         dn->dn_next_nlevels[txgoff] = 0;
 504         dn->dn_next_indblkshift[txgoff] = 0;
 505         dn->dn_next_blksz[txgoff] = 0;
 506
 507         /* ASSERT(blkptrs are zero); */
 508         ASSERT(dn->dn_phys->dn_type != DMU_OT_NONE);
 509         ASSERT(dn->dn_type != DMU_OT_NONE);
 510
 511         ASSERT(dn->dn_free_txg > 0);
 512         if (dn->dn_allocated_txg != dn->dn_free_txg)
 513                 dmu_buf_will_dirty(&dn->dn_dbuf->db, tx);
 514         bzero(dn->dn_phys, sizeof (dnode_phys_t));
 515
 516         mutex_enter(&dn->dn_mtx);
 517         dn->dn_type = DMU_OT_NONE;
 518         dn->dn_maxblkid = 0;
 519         dn->dn_allocated_txg = 0;
 520         dn->dn_free_txg = 0;
 521         dn->dn_have_spill = B_FALSE;
 522         mutex_exit(&dn->dn_mtx);
 523
 524         ASSERT(dn->dn_object != DMU_META_DNODE_OBJECT);
 525
 526         dnode_rele(dn, (void *)(uintptr_t)tx->tx_txg);
 527         /*
 528          * Now that we've released our hold, the dnode may
 529          * be evicted, so we musn't access it.
 530          */
 531 }
 532
 533 /*
 534  * Write out the dnode's dirty buffers.
 535  */
 536 void
 537 dnode_sync(dnode_t *dn, dmu_tx_t *tx)
 538 {
 539         free_range_t *rp;
 540         dnode_phys_t *dnp = dn->dn_phys;
 541         int txgoff = tx->tx_txg & TXG_MASK;
 542         list_t *list = &dn->dn_dirty_records[txgoff];
 543         static const dnode_phys_t zerodn = { 0 };
 544         boolean_t kill_spill = B_FALSE;
 545
 546         ASSERT(dmu_tx_is_syncing(tx));
 547         ASSERT(dnp->dn_type != DMU_OT_NONE || dn->dn_allocated_txg);
 548         ASSERT(dnp->dn_type != DMU_OT_NONE ||
 549             bcmp(dnp, &zerodn, DNODE_SIZE) == 0);
 550         DNODE_VERIFY(dn);
 551
 552         ASSERT(dn->dn_dbuf == NULL || arc_released(dn->dn_dbuf->db_buf));
 553
 554         if (dmu_objset_userused_enabled(dn->dn_objset) &&
 555             !DMU_OBJECT_IS_SPECIAL(dn->dn_object)) {
 556                 mutex_enter(&dn->dn_mtx);
 557                 dn->dn_oldused = DN_USED_BYTES(dn->dn_phys);
 558                 dn->dn_oldflags = dn->dn_phys->dn_flags;
 559                 dn->dn_phys->dn_flags |= DNODE_FLAG_USERUSED_ACCOUNTED;
 560                 mutex_exit(&dn->dn_mtx);
 561                 dmu_objset_userquota_get_ids(dn, B_FALSE, tx);
 562         } else {
 563                 /* Once we account for it, we should always account for it. */
 564                 ASSERT(!(dn->dn_phys->dn_flags &
 565                     DNODE_FLAG_USERUSED_ACCOUNTED));
 566         }
 567
 568         mutex_enter(&dn->dn_mtx);
 569         if (dn->dn_allocated_txg == tx->tx_txg) {
 570                 /* The dnode is newly allocated or reallocated */
 571                 if (dnp->dn_type == DMU_OT_NONE) {
 572                         /* this is a first alloc, not a realloc */
 573                         dnp->dn_nlevels = 1;
 574                         dnp->dn_nblkptr = dn->dn_nblkptr;
 575                 }
 576
 577                 dnp->dn_type = dn->dn_type;
 578                 dnp->dn_bonustype = dn->dn_bonustype;
 579                 dnp->dn_bonuslen = dn->dn_bonuslen;
 580         }
 581
 582         ASSERT(dnp->dn_nlevels > 1 ||
 583             BP_IS_HOLE(&dnp->dn_blkptr[0]) ||
 584             BP_GET_LSIZE(&dnp->dn_blkptr[0]) ==
 585             dnp->dn_datablkszsec << SPA_MINBLOCKSHIFT);
 586
 587         if (dn->dn_next_type[txgoff] != 0) {
 588                 dnp->dn_type = dn->dn_type;
 589                 dn->dn_next_type[txgoff] = 0;
 590         }
 591
 592         if (dn->dn_next_blksz[txgoff] != 0) {
 593                 ASSERT(P2PHASE(dn->dn_next_blksz[txgoff],
 594                     SPA_MINBLOCKSIZE) == 0);
 595                 ASSERT(BP_IS_HOLE(&dnp->dn_blkptr[0]) ||
 596                     dn->dn_maxblkid == 0 || list_head(list) != NULL ||
 597                     avl_last(&dn->dn_ranges[txgoff]) ||
 598                     dn->dn_next_blksz[txgoff] >> SPA_MINBLOCKSHIFT ==
 599                     dnp->dn_datablkszsec);
 600                 dnp->dn_datablkszsec =
 601                     dn->dn_next_blksz[txgoff] >> SPA_MINBLOCKSHIFT;
 602                 dn->dn_next_blksz[txgoff] = 0;
 603         }
 604
 605         if (dn->dn_next_bonuslen[txgoff] != 0) {
 606                 if (dn->dn_next_bonuslen[txgoff] == DN_ZERO_BONUSLEN)
 607                         dnp->dn_bonuslen = 0;
 608                 else
 609                         dnp->dn_bonuslen = dn->dn_next_bonuslen[txgoff];
 610                 ASSERT(dnp->dn_bonuslen <= DN_MAX_BONUSLEN);
 611                 dn->dn_next_bonuslen[txgoff] = 0;
 612         }
 613
 614         if (dn->dn_next_bonustype[txgoff] != 0) {
 615                 ASSERT(DMU_OT_IS_VALID(dn->dn_next_bonustype[txgoff]));
 616                 dnp->dn_bonustype = dn->dn_next_bonustype[txgoff];
 617                 dn->dn_next_bonustype[txgoff] = 0;
 618         }
 619
 620         boolean_t freeing_dnode = dn->dn_free_txg > 0 &&
 621             dn->dn_free_txg <= tx->tx_txg;
 622
 623         /*
 624          * We will either remove a spill block when a file is being removed
 625          * or we have been asked to remove it.
 626          */
 627         if (dn->dn_rm_spillblk[txgoff] ||
 628             ((dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) && freeing_dnode)) {
 629                 if ((dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR))
 630                         kill_spill = B_TRUE;
 631                 dn->dn_rm_spillblk[txgoff] = 0;
 632         }
 633
 634         if (dn->dn_next_indblkshift[txgoff] != 0) {
 635                 ASSERT(dnp->dn_nlevels == 1);
 636                 dnp->dn_indblkshift = dn->dn_next_indblkshift[txgoff];
 637                 dn->dn_next_indblkshift[txgoff] = 0;
 638         }
 639
 640         /*
 641          * Just take the live (open-context) values for checksum and compress.
 642          * Strictly speaking it's a future leak, but nothing bad happens if we
 643          * start using the new checksum or compress algorithm a little early.
 644          */
 645         dnp->dn_checksum = dn->dn_checksum;
 646         dnp->dn_compress = dn->dn_compress;
 647
 648         mutex_exit(&dn->dn_mtx);
 649
 650         if (kill_spill) {
 651                 free_blocks(dn, &dn->dn_phys->dn_spill, 1, tx);
 652                 mutex_enter(&dn->dn_mtx);
 653                 dnp->dn_flags &= ~DNODE_FLAG_SPILL_BLKPTR;
 654                 mutex_exit(&dn->dn_mtx);
 655         }
 656
 657         /* process all the "freed" ranges in the file */
 658         while (rp = avl_last(&dn->dn_ranges[txgoff])) {
 659                 dnode_sync_free_range(dn, rp->fr_blkid, rp->fr_nblks, tx);
 660                 /* grab the mutex so we don't race with dnode_block_freed() */
 661                 mutex_enter(&dn->dn_mtx);
 662                 avl_remove(&dn->dn_ranges[txgoff], rp);
 663                 mutex_exit(&dn->dn_mtx);
 664                 kmem_free(rp, sizeof (free_range_t));
 665         }
 666
 667         if (freeing_dnode) {
 668                 dnode_sync_free(dn, tx);
 669                 return;
 670         }
 671
 672         if (dn->dn_next_nblkptr[txgoff]) {
 673                 /* this should only happen on a realloc */
 674                 ASSERT(dn->dn_allocated_txg == tx->tx_txg);
 675                 if (dn->dn_next_nblkptr[txgoff] > dnp->dn_nblkptr) {
 676                         /* zero the new blkptrs we are gaining */
 677                         bzero(dnp->dn_blkptr + dnp->dn_nblkptr,
 678                             sizeof (blkptr_t) *
 679                             (dn->dn_next_nblkptr[txgoff] - dnp->dn_nblkptr));
 680 #ifdef ZFS_DEBUG
 681                 } else {
 682                         int i;
 683                         ASSERT(dn->dn_next_nblkptr[txgoff] < dnp->dn_nblkptr);
 684                         /* the blkptrs we are losing better be unallocated */
 685                         for (i = dn->dn_next_nblkptr[txgoff];
 686                             i < dnp->dn_nblkptr; i++)
 687                                 ASSERT(BP_IS_HOLE(&dnp->dn_blkptr[i]));
 688 #endif
 689                 }
 690                 mutex_enter(&dn->dn_mtx);
 691                 dnp->dn_nblkptr = dn->dn_next_nblkptr[txgoff];
 692                 dn->dn_next_nblkptr[txgoff] = 0;
 693                 mutex_exit(&dn->dn_mtx);
 694         }
 695
 696         if (dn->dn_next_nlevels[txgoff]) {
 697                 dnode_increase_indirection(dn, tx);
 698                 dn->dn_next_nlevels[txgoff] = 0;
 699         }
 700
 701         dbuf_sync_list(list, tx);
 702
 703         if (!DMU_OBJECT_IS_SPECIAL(dn->dn_object)) {
 704                 ASSERT3P(list_head(list), ==, NULL);
 705                 dnode_rele(dn, (void *)(uintptr_t)tx->tx_txg);
 706         }
 707
 708         /*
 709          * Although we have dropped our reference to the dnode, it
 710          * can't be evicted until its written, and we haven't yet
 711          * initiated the IO for the dnode's dbuf.
 712          */
 713 }