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  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
  23  * Use is subject to license terms.
  24  */
  25
  26 #pragma ident   "%Z%%M% %I%     %E% SMI"
  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
  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                 ASSERT3P(child->db_dnode, ==, dn);
  83                 if (child->db_parent && child->db_parent != dn->dn_dbuf) {
  84                         ASSERT(child->db_parent->db_level == db->db_level);
  85                         ASSERT(child->db_blkptr !=
  86                             &dn->dn_phys->dn_blkptr[child->db_blkid]);
  87                         mutex_exit(&child->db_mtx);
  88                         continue;
  89                 }
  90                 ASSERT(child->db_parent == NULL ||
  91                     child->db_parent == dn->dn_dbuf);
  92
  93                 child->db_parent = db;
  94                 dbuf_add_ref(db, child);
  95                 if (db->db.db_data)
  96                         child->db_blkptr = (blkptr_t *)db->db.db_data + i;
  97                 else
  98                         child->db_blkptr = NULL;
  99                 dprintf_dbuf_bp(child, child->db_blkptr,
 100                     "changed db_blkptr to new indirect %s", "");
 101
 102                 mutex_exit(&child->db_mtx);
 103         }
 104
 105         bzero(dn->dn_phys->dn_blkptr, sizeof (blkptr_t) * nblkptr);
 106
 107         dbuf_rele(db, FTAG);
 108
 109         rw_exit(&dn->dn_struct_rwlock);
 110 }
 111
 112 static int
 113 free_blocks(dnode_t *dn, blkptr_t *bp, int num, dmu_tx_t *tx)
 114 {
 115         dsl_dataset_t *ds = dn->dn_objset->os_dsl_dataset;
 116         uint64_t bytesfreed = 0;
 117         int i, blocks_freed = 0;
 118
 119         dprintf("ds=%p obj=%llx num=%d\n", ds, dn->dn_object, num);
 120
 121         for (i = 0; i < num; i++, bp++) {
 122                 if (BP_IS_HOLE(bp))
 123                         continue;
 124
 125                 bytesfreed += dsl_dataset_block_kill(ds, bp, dn->dn_zio, tx);
 126                 ASSERT3U(bytesfreed, <=, DN_USED_BYTES(dn->dn_phys));
 127                 bzero(bp, sizeof (blkptr_t));
 128                 blocks_freed += 1;
 129         }
 130         dnode_diduse_space(dn, -bytesfreed);
 131         return (blocks_freed);
 132 }
 133
 134 #ifdef ZFS_DEBUG
 135 static void
 136 free_verify(dmu_buf_impl_t *db, uint64_t start, uint64_t end, dmu_tx_t *tx)
 137 {
 138         int off, num;
 139         int i, err, epbs;
 140         uint64_t txg = tx->tx_txg;
 141
 142         epbs = db->db_dnode->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT;
 143         off = start - (db->db_blkid * 1<<epbs);
 144         num = end - start + 1;
 145
 146         ASSERT3U(off, >=, 0);
 147         ASSERT3U(num, >=, 0);
 148         ASSERT3U(db->db_level, >, 0);
 149         ASSERT3U(db->db.db_size, ==, 1<<db->db_dnode->dn_phys->dn_indblkshift);
 150         ASSERT3U(off+num, <=, db->db.db_size >> SPA_BLKPTRSHIFT);
 151         ASSERT(db->db_blkptr != NULL);
 152
 153         for (i = off; i < off+num; i++) {
 154                 uint64_t *buf;
 155                 dmu_buf_impl_t *child;
 156                 dbuf_dirty_record_t *dr;
 157                 int j;
 158
 159                 ASSERT(db->db_level == 1);
 160
 161                 rw_enter(&db->db_dnode->dn_struct_rwlock, RW_READER);
 162                 err = dbuf_hold_impl(db->db_dnode, db->db_level-1,
 163                     (db->db_blkid << epbs) + i, TRUE, FTAG, &child);
 164                 rw_exit(&db->db_dnode->dn_struct_rwlock);
 165                 if (err == ENOENT)
 166                         continue;
 167                 ASSERT(err == 0);
 168                 ASSERT(child->db_level == 0);
 169                 dr = child->db_last_dirty;
 170                 while (dr && dr->dr_txg > txg)
 171                         dr = dr->dr_next;
 172                 ASSERT(dr == NULL || dr->dr_txg == txg);
 173
 174                 /* data_old better be zeroed */
 175                 if (dr) {
 176                         buf = dr->dt.dl.dr_data->b_data;
 177                         for (j = 0; j < child->db.db_size >> 3; j++) {
 178                                 if (buf[j] != 0) {
 179                                         panic("freed data not zero: "
 180                                             "child=%p i=%d off=%d num=%d\n",
 181                                             (void *)child, i, off, num);
 182                                 }
 183                         }
 184                 }
 185
 186                 /*
 187                  * db_data better be zeroed unless it's dirty in a
 188                  * future txg.
 189                  */
 190                 mutex_enter(&child->db_mtx);
 191                 buf = child->db.db_data;
 192                 if (buf != NULL && child->db_state != DB_FILL &&
 193                     child->db_last_dirty == NULL) {
 194                         for (j = 0; j < child->db.db_size >> 3; j++) {
 195                                 if (buf[j] != 0) {
 196                                         panic("freed data not zero: "
 197                                             "child=%p i=%d off=%d num=%d\n",
 198                                             (void *)child, i, off, num);
 199                                 }
 200                         }
 201                 }
 202                 mutex_exit(&child->db_mtx);
 203
 204                 dbuf_rele(child, FTAG);
 205         }
 206 }
 207 #endif
 208
 209 #define ALL -1
 210
 211 static int
 212 free_children(dmu_buf_impl_t *db, uint64_t blkid, uint64_t nblks, int trunc,
 213     dmu_tx_t *tx)
 214 {
 215         dnode_t *dn = db->db_dnode;
 216         blkptr_t *bp;
 217         dmu_buf_impl_t *subdb;
 218         uint64_t start, end, dbstart, dbend, i;
 219         int epbs, shift, err;
 220         int all = TRUE;
 221         int blocks_freed = 0;
 222
 223         /*
 224          * There is a small possibility that this block will not be cached:
 225          *   1 - if level > 1 and there are no children with level <= 1
 226          *   2 - if we didn't get a dirty hold (because this block had just
 227          *       finished being written -- and so had no holds), and then this
 228          *       block got evicted before we got here.
 229          */
 230         if (db->db_state != DB_CACHED)
 231                 (void) dbuf_read(db, NULL, DB_RF_MUST_SUCCEED);
 232
 233         arc_release(db->db_buf, db);
 234         bp = (blkptr_t *)db->db.db_data;
 235
 236         epbs = db->db_dnode->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT;
 237         shift = (db->db_level - 1) * epbs;
 238         dbstart = db->db_blkid << epbs;
 239         start = blkid >> shift;
 240         if (dbstart < start) {
 241                 bp += start - dbstart;
 242                 all = FALSE;
 243         } else {
 244                 start = dbstart;
 245         }
 246         dbend = ((db->db_blkid + 1) << epbs) - 1;
 247         end = (blkid + nblks - 1) >> shift;
 248         if (dbend <= end)
 249                 end = dbend;
 250         else if (all)
 251                 all = trunc;
 252         ASSERT3U(start, <=, end);
 253
 254         if (db->db_level == 1) {
 255                 FREE_VERIFY(db, start, end, tx);
 256                 blocks_freed = free_blocks(dn, bp, end-start+1, tx);
 257                 arc_buf_freeze(db->db_buf);
 258                 ASSERT(all || blocks_freed == 0 || db->db_last_dirty);
 259                 return (all ? ALL : blocks_freed);
 260         }
 261
 262         for (i = start; i <= end; i++, bp++) {
 263                 if (BP_IS_HOLE(bp))
 264                         continue;
 265                 rw_enter(&dn->dn_struct_rwlock, RW_READER);
 266                 err = dbuf_hold_impl(dn, db->db_level-1, i, TRUE, FTAG, &subdb);
 267                 ASSERT3U(err, ==, 0);
 268                 rw_exit(&dn->dn_struct_rwlock);
 269
 270                 if (free_children(subdb, blkid, nblks, trunc, tx) == ALL) {
 271                         ASSERT3P(subdb->db_blkptr, ==, bp);
 272                         blocks_freed += free_blocks(dn, bp, 1, tx);
 273                 } else {
 274                         all = FALSE;
 275                 }
 276                 dbuf_rele(subdb, FTAG);
 277         }
 278         arc_buf_freeze(db->db_buf);
 279 #ifdef ZFS_DEBUG
 280         bp -= (end-start)+1;
 281         for (i = start; i <= end; i++, bp++) {
 282                 if (i == start && blkid != 0)
 283                         continue;
 284                 else if (i == end && !trunc)
 285                         continue;
 286                 ASSERT3U(bp->blk_birth, ==, 0);
 287         }
 288 #endif
 289         ASSERT(all || blocks_freed == 0 || db->db_last_dirty);
 290         return (all ? ALL : blocks_freed);
 291 }
 292
 293 /*
 294  * free_range: Traverse the indicated range of the provided file
 295  * and "free" all the blocks contained there.
 296  */
 297 static void
 298 dnode_sync_free_range(dnode_t *dn, uint64_t blkid, uint64_t nblks, dmu_tx_t *tx)
 299 {
 300         blkptr_t *bp = dn->dn_phys->dn_blkptr;
 301         dmu_buf_impl_t *db;
 302         int trunc, start, end, shift, i, err;
 303         int dnlevel = dn->dn_phys->dn_nlevels;
 304
 305         if (blkid > dn->dn_phys->dn_maxblkid)
 306                 return;
 307
 308         ASSERT(dn->dn_phys->dn_maxblkid < UINT64_MAX);
 309         trunc = blkid + nblks > dn->dn_phys->dn_maxblkid;
 310         if (trunc)
 311                 nblks = dn->dn_phys->dn_maxblkid - blkid + 1;
 312
 313         /* There are no indirect blocks in the object */
 314         if (dnlevel == 1) {
 315                 if (blkid >= dn->dn_phys->dn_nblkptr) {
 316                         /* this range was never made persistent */
 317                         return;
 318                 }
 319                 ASSERT3U(blkid + nblks, <=, dn->dn_phys->dn_nblkptr);
 320                 (void) free_blocks(dn, bp + blkid, nblks, tx);
 321                 if (trunc) {
 322                         uint64_t off = (dn->dn_phys->dn_maxblkid + 1) *
 323                             (dn->dn_phys->dn_datablkszsec << SPA_MINBLOCKSHIFT);
 324                         dn->dn_phys->dn_maxblkid = (blkid ? blkid - 1 : 0);
 325                         ASSERT(off < dn->dn_phys->dn_maxblkid ||
 326                             dn->dn_phys->dn_maxblkid == 0 ||
 327                             dnode_next_offset(dn, 0, &off, 1, 1, 0) != 0);
 328                 }
 329                 return;
 330         }
 331
 332         shift = (dnlevel - 1) * (dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT);
 333         start = blkid >> shift;
 334         ASSERT(start < dn->dn_phys->dn_nblkptr);
 335         end = (blkid + nblks - 1) >> shift;
 336         bp += start;
 337         for (i = start; i <= end; i++, bp++) {
 338                 if (BP_IS_HOLE(bp))
 339                         continue;
 340                 rw_enter(&dn->dn_struct_rwlock, RW_READER);
 341                 err = dbuf_hold_impl(dn, dnlevel-1, i, TRUE, FTAG, &db);
 342                 ASSERT3U(err, ==, 0);
 343                 rw_exit(&dn->dn_struct_rwlock);
 344
 345                 if (free_children(db, blkid, nblks, trunc, tx) == ALL) {
 346                         ASSERT3P(db->db_blkptr, ==, bp);
 347                         (void) free_blocks(dn, bp, 1, tx);
 348                 }
 349                 dbuf_rele(db, FTAG);
 350         }
 351         if (trunc) {
 352                 uint64_t off = (dn->dn_phys->dn_maxblkid + 1) *
 353                     (dn->dn_phys->dn_datablkszsec << SPA_MINBLOCKSHIFT);
 354                 dn->dn_phys->dn_maxblkid = (blkid ? blkid - 1 : 0);
 355                 ASSERT(off < dn->dn_phys->dn_maxblkid ||
 356                     dn->dn_phys->dn_maxblkid == 0 ||
 357                     dnode_next_offset(dn, 0, &off, 1, 1, 0) != 0);
 358         }
 359 }
 360
 361 /*
 362  * Try to kick all the dnodes dbufs out of the cache...
 363  */
 364 void
 365 dnode_evict_dbufs(dnode_t *dn)
 366 {
 367         int progress;
 368         int pass = 0;
 369
 370         do {
 371                 dmu_buf_impl_t *db, marker;
 372                 int evicting = FALSE;
 373
 374                 progress = FALSE;
 375                 mutex_enter(&dn->dn_dbufs_mtx);
 376                 list_insert_tail(&dn->dn_dbufs, &marker);
 377                 db = list_head(&dn->dn_dbufs);
 378                 for (; db != &marker; db = list_head(&dn->dn_dbufs)) {
 379                         list_remove(&dn->dn_dbufs, db);
 380                         list_insert_tail(&dn->dn_dbufs, db);
 381                         ASSERT3P(db->db_dnode, ==, dn);
 382
 383                         mutex_enter(&db->db_mtx);
 384                         if (db->db_state == DB_EVICTING) {
 385                                 progress = TRUE;
 386                                 evicting = TRUE;
 387                                 mutex_exit(&db->db_mtx);
 388                         } else if (refcount_is_zero(&db->db_holds)) {
 389                                 progress = TRUE;
 390                                 dbuf_clear(db); /* exits db_mtx for us */
 391                         } else {
 392                                 mutex_exit(&db->db_mtx);
 393                         }
 394
 395                 }
 396                 list_remove(&dn->dn_dbufs, &marker);
 397                 /*
 398                  * NB: we need to drop dn_dbufs_mtx between passes so
 399                  * that any DB_EVICTING dbufs can make progress.
 400                  * Ideally, we would have some cv we could wait on, but
 401                  * since we don't, just wait a bit to give the other
 402                  * thread a chance to run.
 403                  */
 404                 mutex_exit(&dn->dn_dbufs_mtx);
 405                 if (evicting)
 406                         delay(1);
 407                 pass++;
 408                 ASSERT(pass < 100); /* sanity check */
 409         } while (progress);
 410
 411         rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
 412         if (dn->dn_bonus && refcount_is_zero(&dn->dn_bonus->db_holds)) {
 413                 mutex_enter(&dn->dn_bonus->db_mtx);
 414                 dbuf_evict(dn->dn_bonus);
 415                 dn->dn_bonus = NULL;
 416         }
 417         rw_exit(&dn->dn_struct_rwlock);
 418 }
 419
 420 static void
 421 dnode_undirty_dbufs(list_t *list)
 422 {
 423         dbuf_dirty_record_t *dr;
 424
 425         while (dr = list_head(list)) {
 426                 dmu_buf_impl_t *db = dr->dr_dbuf;
 427                 uint64_t txg = dr->dr_txg;
 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 == DB_BONUS_BLKID ||
 437                             dr->dt.dl.dr_data == db->db_buf);
 438                         dbuf_unoverride(dr);
 439                         mutex_exit(&db->db_mtx);
 440                 } else {
 441                         mutex_exit(&db->db_mtx);
 442                         dnode_undirty_dbufs(&dr->dt.di.dr_children);
 443                         list_destroy(&dr->dt.di.dr_children);
 444                         mutex_destroy(&dr->dt.di.dr_mtx);
 445                 }
 446                 kmem_free(dr, sizeof (dbuf_dirty_record_t));
 447                 dbuf_rele(db, (void *)(uintptr_t)txg);
 448         }
 449 }
 450
 451 static void
 452 dnode_sync_free(dnode_t *dn, dmu_tx_t *tx)
 453 {
 454         int txgoff = tx->tx_txg & TXG_MASK;
 455
 456         ASSERT(dmu_tx_is_syncing(tx));
 457
 458         /*
 459          * Our contents should have been freed in dnode_sync() by the
 460          * free range record inserted by the caller of dnode_free().
 461          */
 462         ASSERT3U(DN_USED_BYTES(dn->dn_phys), ==, 0);
 463         ASSERT(BP_IS_HOLE(dn->dn_phys->dn_blkptr));
 464
 465         dnode_undirty_dbufs(&dn->dn_dirty_records[txgoff]);
 466         dnode_evict_dbufs(dn);
 467         ASSERT3P(list_head(&dn->dn_dbufs), ==, NULL);
 468
 469         /*
 470          * XXX - It would be nice to assert this, but we may still
 471          * have residual holds from async evictions from the arc...
 472          *
 473          * zfs_obj_to_path() also depends on this being
 474          * commented out.
 475          *
 476          * ASSERT3U(refcount_count(&dn->dn_holds), ==, 1);
 477          */
 478
 479         /* Undirty next bits */
 480         dn->dn_next_nlevels[txgoff] = 0;
 481         dn->dn_next_indblkshift[txgoff] = 0;
 482         dn->dn_next_blksz[txgoff] = 0;
 483
 484         /* ASSERT(blkptrs are zero); */
 485         ASSERT(dn->dn_phys->dn_type != DMU_OT_NONE);
 486         ASSERT(dn->dn_type != DMU_OT_NONE);
 487
 488         ASSERT(dn->dn_free_txg > 0);
 489         if (dn->dn_allocated_txg != dn->dn_free_txg)
 490                 dbuf_will_dirty(dn->dn_dbuf, tx);
 491         bzero(dn->dn_phys, sizeof (dnode_phys_t));
 492
 493         mutex_enter(&dn->dn_mtx);
 494         dn->dn_type = DMU_OT_NONE;
 495         dn->dn_maxblkid = 0;
 496         dn->dn_allocated_txg = 0;
 497         dn->dn_free_txg = 0;
 498         mutex_exit(&dn->dn_mtx);
 499
 500         ASSERT(dn->dn_object != DMU_META_DNODE_OBJECT);
 501
 502         dnode_rele(dn, (void *)(uintptr_t)tx->tx_txg);
 503         /*
 504          * Now that we've released our hold, the dnode may
 505          * be evicted, so we musn't access it.
 506          */
 507 }
 508
 509 /*
 510  * Write out the dnode's dirty buffers.
 511  *
 512  * NOTE: The dnode is kept in memory by being dirty.  Once the
 513  * dirty bit is cleared, it may be evicted.  Beware of this!
 514  */
 515 void
 516 dnode_sync(dnode_t *dn, dmu_tx_t *tx)
 517 {
 518         free_range_t *rp;
 519         dnode_phys_t *dnp = dn->dn_phys;
 520         int txgoff = tx->tx_txg & TXG_MASK;
 521         list_t *list = &dn->dn_dirty_records[txgoff];
 522
 523         ASSERT(dmu_tx_is_syncing(tx));
 524         ASSERT(dnp->dn_type != DMU_OT_NONE || dn->dn_allocated_txg);
 525         DNODE_VERIFY(dn);
 526
 527         ASSERT(dn->dn_dbuf == NULL || arc_released(dn->dn_dbuf->db_buf));
 528
 529         mutex_enter(&dn->dn_mtx);
 530         if (dn->dn_allocated_txg == tx->tx_txg) {
 531                 /* The dnode is newly allocated or reallocated */
 532                 if (dnp->dn_type == DMU_OT_NONE) {
 533                         /* this is a first alloc, not a realloc */
 534                         /* XXX shouldn't the phys already be zeroed? */
 535                         bzero(dnp, DNODE_CORE_SIZE);
 536                         dnp->dn_nlevels = 1;
 537                 }
 538
 539                 if (dn->dn_nblkptr > dnp->dn_nblkptr) {
 540                         /* zero the new blkptrs we are gaining */
 541                         bzero(dnp->dn_blkptr + dnp->dn_nblkptr,
 542                             sizeof (blkptr_t) *
 543                             (dn->dn_nblkptr - dnp->dn_nblkptr));
 544                 }
 545                 dnp->dn_type = dn->dn_type;
 546                 dnp->dn_bonustype = dn->dn_bonustype;
 547                 dnp->dn_bonuslen = dn->dn_bonuslen;
 548                 dnp->dn_nblkptr = dn->dn_nblkptr;
 549         }
 550
 551         ASSERT(dnp->dn_nlevels > 1 ||
 552             BP_IS_HOLE(&dnp->dn_blkptr[0]) ||
 553             BP_GET_LSIZE(&dnp->dn_blkptr[0]) ==
 554             dnp->dn_datablkszsec << SPA_MINBLOCKSHIFT);
 555
 556         if (dn->dn_next_blksz[txgoff]) {
 557                 ASSERT(P2PHASE(dn->dn_next_blksz[txgoff],
 558                     SPA_MINBLOCKSIZE) == 0);
 559                 ASSERT(BP_IS_HOLE(&dnp->dn_blkptr[0]) ||
 560                     dn->dn_maxblkid == 0 || list_head(list) != NULL ||
 561                     dn->dn_next_blksz[txgoff] >> SPA_MINBLOCKSHIFT ==
 562                     dnp->dn_datablkszsec);
 563                 dnp->dn_datablkszsec =
 564                     dn->dn_next_blksz[txgoff] >> SPA_MINBLOCKSHIFT;
 565                 dn->dn_next_blksz[txgoff] = 0;
 566         }
 567
 568         if (dn->dn_next_bonuslen[txgoff]) {
 569                 if (dn->dn_next_bonuslen[txgoff] == DN_ZERO_BONUSLEN)
 570                         dnp->dn_bonuslen = 0;
 571                 else
 572                         dnp->dn_bonuslen = dn->dn_next_bonuslen[txgoff];
 573                 ASSERT(dnp->dn_bonuslen <= DN_MAX_BONUSLEN);
 574                 dn->dn_next_bonuslen[txgoff] = 0;
 575         }
 576
 577         if (dn->dn_next_indblkshift[txgoff]) {
 578                 ASSERT(dnp->dn_nlevels == 1);
 579                 dnp->dn_indblkshift = dn->dn_next_indblkshift[txgoff];
 580                 dn->dn_next_indblkshift[txgoff] = 0;
 581         }
 582
 583         /*
 584          * Just take the live (open-context) values for checksum and compress.
 585          * Strictly speaking it's a future leak, but nothing bad happens if we
 586          * start using the new checksum or compress algorithm a little early.
 587          */
 588         dnp->dn_checksum = dn->dn_checksum;
 589         dnp->dn_compress = dn->dn_compress;
 590
 591         mutex_exit(&dn->dn_mtx);
 592
 593         /* process all the "freed" ranges in the file */
 594         while (rp = avl_last(&dn->dn_ranges[txgoff])) {
 595                 dnode_sync_free_range(dn, rp->fr_blkid, rp->fr_nblks, tx);
 596                 /* grab the mutex so we don't race with dnode_block_freed() */
 597                 mutex_enter(&dn->dn_mtx);
 598                 avl_remove(&dn->dn_ranges[txgoff], rp);
 599                 mutex_exit(&dn->dn_mtx);
 600                 kmem_free(rp, sizeof (free_range_t));
 601         }
 602
 603         if (dn->dn_free_txg > 0 && dn->dn_free_txg <= tx->tx_txg) {
 604                 dnode_sync_free(dn, tx);
 605                 return;
 606         }
 607
 608         if (dn->dn_next_nlevels[txgoff]) {
 609                 dnode_increase_indirection(dn, tx);
 610                 dn->dn_next_nlevels[txgoff] = 0;
 611         }
 612
 613         dbuf_sync_list(list, tx);
 614
 615         if (dn->dn_object != DMU_META_DNODE_OBJECT) {
 616                 ASSERT3P(list_head(list), ==, NULL);
 617                 dnode_rele(dn, (void *)(uintptr_t)tx->tx_txg);
 618         }
 619
 620         /*
 621          * Although we have dropped our reference to the dnode, it
 622          * can't be evicted until its written, and we haven't yet
 623          * initiated the IO for the dnode's dbuf.
 624          */
 625 }