sys/contrib/openzfs/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 https://opensource.org/licenses/CDDL-1.0.
  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, 2020 by Delphix. All rights reserved.
  25  * Copyright (c) 2014 Spectra Logic Corporation, All rights reserved.
  26  * Copyright 2020 Oxide Computer Company
  27  */
  28
  29 #include <sys/zfs_context.h>
  30 #include <sys/dbuf.h>
  31 #include <sys/dnode.h>
  32 #include <sys/dmu.h>
  33 #include <sys/dmu_tx.h>
  34 #include <sys/dmu_objset.h>
  35 #include <sys/dmu_recv.h>
  36 #include <sys/dsl_dataset.h>
  37 #include <sys/spa.h>
  38 #include <sys/range_tree.h>
  39 #include <sys/zfeature.h>
  40
  41 static void
  42 dnode_increase_indirection(dnode_t *dn, dmu_tx_t *tx)
  43 {
  44         dmu_buf_impl_t *db;
  45         int txgoff = tx->tx_txg & TXG_MASK;
  46         int nblkptr = dn->dn_phys->dn_nblkptr;
  47         int old_toplvl = dn->dn_phys->dn_nlevels - 1;
  48         int new_level = dn->dn_next_nlevels[txgoff];
  49         int i;
  50
  51         rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
  52
  53         /* this dnode can't be paged out because it's dirty */
  54         ASSERT(dn->dn_phys->dn_type != DMU_OT_NONE);
  55         ASSERT(new_level > 1 && dn->dn_phys->dn_nlevels > 0);
  56
  57         db = dbuf_hold_level(dn, dn->dn_phys->dn_nlevels, 0, FTAG);
  58         ASSERT(db != NULL);
  59
  60         dn->dn_phys->dn_nlevels = new_level;
  61         dprintf("os=%p obj=%llu, increase to %d\n", dn->dn_objset,
  62             (u_longlong_t)dn->dn_object, dn->dn_phys->dn_nlevels);
  63
  64         /*
  65          * Lock ordering requires that we hold the children's db_mutexes (by
  66          * calling dbuf_find()) before holding the parent's db_rwlock.  The lock
  67          * order is imposed by dbuf_read's steps of "grab the lock to protect
  68          * db_parent, get db_parent, hold db_parent's db_rwlock".
  69          */
  70         dmu_buf_impl_t *children[DN_MAX_NBLKPTR];
  71         ASSERT3U(nblkptr, <=, DN_MAX_NBLKPTR);
  72         for (i = 0; i < nblkptr; i++) {
  73                 children[i] = dbuf_find(dn->dn_objset, dn->dn_object,
  74                     old_toplvl, i, NULL);
  75         }
  76
  77         /* transfer dnode's block pointers to new indirect block */
  78         (void) dbuf_read(db, NULL, DB_RF_MUST_SUCCEED|DB_RF_HAVESTRUCT);
  79         if (dn->dn_dbuf != NULL)
  80                 rw_enter(&dn->dn_dbuf->db_rwlock, RW_WRITER);
  81         rw_enter(&db->db_rwlock, RW_WRITER);
  82         ASSERT(db->db.db_data);
  83         ASSERT(arc_released(db->db_buf));
  84         ASSERT3U(sizeof (blkptr_t) * nblkptr, <=, db->db.db_size);
  85         memcpy(db->db.db_data, dn->dn_phys->dn_blkptr,
  86             sizeof (blkptr_t) * nblkptr);
  87         arc_buf_freeze(db->db_buf);
  88
  89         /* set dbuf's parent pointers to new indirect buf */
  90         for (i = 0; i < nblkptr; i++) {
  91                 dmu_buf_impl_t *child = children[i];
  92
  93                 if (child == NULL)
  94                         continue;
  95 #ifdef  ZFS_DEBUG
  96                 DB_DNODE_ENTER(child);
  97                 ASSERT3P(DB_DNODE(child), ==, dn);
  98                 DB_DNODE_EXIT(child);
  99 #endif  /* DEBUG */
 100                 if (child->db_parent && child->db_parent != dn->dn_dbuf) {
 101                         ASSERT(child->db_parent->db_level == db->db_level);
 102                         ASSERT(child->db_blkptr !=
 103                             &dn->dn_phys->dn_blkptr[child->db_blkid]);
 104                         mutex_exit(&child->db_mtx);
 105                         continue;
 106                 }
 107                 ASSERT(child->db_parent == NULL ||
 108                     child->db_parent == dn->dn_dbuf);
 109
 110                 child->db_parent = db;
 111                 dbuf_add_ref(db, child);
 112                 if (db->db.db_data)
 113                         child->db_blkptr = (blkptr_t *)db->db.db_data + i;
 114                 else
 115                         child->db_blkptr = NULL;
 116                 dprintf_dbuf_bp(child, child->db_blkptr,
 117                     "changed db_blkptr to new indirect %s", "");
 118
 119                 mutex_exit(&child->db_mtx);
 120         }
 121
 122         memset(dn->dn_phys->dn_blkptr, 0, sizeof (blkptr_t) * nblkptr);
 123
 124         rw_exit(&db->db_rwlock);
 125         if (dn->dn_dbuf != NULL)
 126                 rw_exit(&dn->dn_dbuf->db_rwlock);
 127
 128         dbuf_rele(db, FTAG);
 129
 130         rw_exit(&dn->dn_struct_rwlock);
 131 }
 132
 133 static void
 134 free_blocks(dnode_t *dn, blkptr_t *bp, int num, dmu_tx_t *tx)
 135 {
 136         dsl_dataset_t *ds = dn->dn_objset->os_dsl_dataset;
 137         uint64_t bytesfreed = 0;
 138
 139         dprintf("ds=%p obj=%llx num=%d\n", ds, (u_longlong_t)dn->dn_object,
 140             num);
 141
 142         for (int i = 0; i < num; i++, bp++) {
 143                 if (BP_IS_HOLE(bp))
 144                         continue;
 145
 146                 bytesfreed += dsl_dataset_block_kill(ds, bp, tx, B_FALSE);
 147                 ASSERT3U(bytesfreed, <=, DN_USED_BYTES(dn->dn_phys));
 148
 149                 /*
 150                  * Save some useful information on the holes being
 151                  * punched, including logical size, type, and indirection
 152                  * level. Retaining birth time enables detection of when
 153                  * holes are punched for reducing the number of free
 154                  * records transmitted during a zfs send.
 155                  */
 156
 157                 uint64_t lsize = BP_GET_LSIZE(bp);
 158                 dmu_object_type_t type = BP_GET_TYPE(bp);
 159                 uint64_t lvl = BP_GET_LEVEL(bp);
 160
 161                 memset(bp, 0, sizeof (blkptr_t));
 162
 163                 if (spa_feature_is_active(dn->dn_objset->os_spa,
 164                     SPA_FEATURE_HOLE_BIRTH)) {
 165                         BP_SET_LSIZE(bp, lsize);
 166                         BP_SET_TYPE(bp, type);
 167                         BP_SET_LEVEL(bp, lvl);
 168                         BP_SET_BIRTH(bp, dmu_tx_get_txg(tx), 0);
 169                 }
 170         }
 171         dnode_diduse_space(dn, -bytesfreed);
 172 }
 173
 174 #ifdef ZFS_DEBUG
 175 static void
 176 free_verify(dmu_buf_impl_t *db, uint64_t start, uint64_t end, dmu_tx_t *tx)
 177 {
 178         uint64_t off, num, i, j;
 179         unsigned int epbs;
 180         int err;
 181         uint64_t txg = tx->tx_txg;
 182         dnode_t *dn;
 183
 184         DB_DNODE_ENTER(db);
 185         dn = DB_DNODE(db);
 186         epbs = dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT;
 187         off = start - (db->db_blkid << epbs);
 188         num = end - start + 1;
 189
 190         ASSERT3U(dn->dn_phys->dn_indblkshift, >=, SPA_BLKPTRSHIFT);
 191         ASSERT3U(end + 1, >=, start);
 192         ASSERT3U(start, >=, (db->db_blkid << epbs));
 193         ASSERT3U(db->db_level, >, 0);
 194         ASSERT3U(db->db.db_size, ==, 1 << dn->dn_phys->dn_indblkshift);
 195         ASSERT3U(off+num, <=, db->db.db_size >> SPA_BLKPTRSHIFT);
 196         ASSERT(db->db_blkptr != NULL);
 197
 198         for (i = off; i < off+num; i++) {
 199                 uint64_t *buf;
 200                 dmu_buf_impl_t *child;
 201                 dbuf_dirty_record_t *dr;
 202
 203                 ASSERT(db->db_level == 1);
 204
 205                 rw_enter(&dn->dn_struct_rwlock, RW_READER);
 206                 err = dbuf_hold_impl(dn, db->db_level - 1,
 207                     (db->db_blkid << epbs) + i, TRUE, FALSE, FTAG, &child);
 208                 rw_exit(&dn->dn_struct_rwlock);
 209                 if (err == ENOENT)
 210                         continue;
 211                 ASSERT(err == 0);
 212                 ASSERT(child->db_level == 0);
 213                 dr = dbuf_find_dirty_eq(child, txg);
 214
 215                 /* data_old better be zeroed */
 216                 if (dr) {
 217                         buf = dr->dt.dl.dr_data->b_data;
 218                         for (j = 0; j < child->db.db_size >> 3; j++) {
 219                                 if (buf[j] != 0) {
 220                                         panic("freed data not zero: "
 221                                             "child=%p i=%llu off=%llu "
 222                                             "num=%llu\n",
 223                                             (void *)child, (u_longlong_t)i,
 224                                             (u_longlong_t)off,
 225                                             (u_longlong_t)num);
 226                                 }
 227                         }
 228                 }
 229
 230                 /*
 231                  * db_data better be zeroed unless it's dirty in a
 232                  * future txg.
 233                  */
 234                 mutex_enter(&child->db_mtx);
 235                 buf = child->db.db_data;
 236                 if (buf != NULL && child->db_state != DB_FILL &&
 237                     list_is_empty(&child->db_dirty_records)) {
 238                         for (j = 0; j < child->db.db_size >> 3; j++) {
 239                                 if (buf[j] != 0) {
 240                                         panic("freed data not zero: "
 241                                             "child=%p i=%llu off=%llu "
 242                                             "num=%llu\n",
 243                                             (void *)child, (u_longlong_t)i,
 244                                             (u_longlong_t)off,
 245                                             (u_longlong_t)num);
 246                                 }
 247                         }
 248                 }
 249                 mutex_exit(&child->db_mtx);
 250
 251                 dbuf_rele(child, FTAG);
 252         }
 253         DB_DNODE_EXIT(db);
 254 }
 255 #endif
 256
 257 /*
 258  * We don't usually free the indirect blocks here.  If in one txg we have a
 259  * free_range and a write to the same indirect block, it's important that we
 260  * preserve the hole's birth times. Therefore, we don't free any any indirect
 261  * blocks in free_children().  If an indirect block happens to turn into all
 262  * holes, it will be freed by dbuf_write_children_ready, which happens at a
 263  * point in the syncing process where we know for certain the contents of the
 264  * indirect block.
 265  *
 266  * However, if we're freeing a dnode, its space accounting must go to zero
 267  * before we actually try to free the dnode, or we will trip an assertion. In
 268  * addition, we know the case described above cannot occur, because the dnode is
 269  * being freed.  Therefore, we free the indirect blocks immediately in that
 270  * case.
 271  */
 272 static void
 273 free_children(dmu_buf_impl_t *db, uint64_t blkid, uint64_t nblks,
 274     boolean_t free_indirects, dmu_tx_t *tx)
 275 {
 276         dnode_t *dn;
 277         blkptr_t *bp;
 278         dmu_buf_impl_t *subdb;
 279         uint64_t start, end, dbstart, dbend;
 280         unsigned int epbs, shift, i;
 281
 282         /*
 283          * There is a small possibility that this block will not be cached:
 284          *   1 - if level > 1 and there are no children with level <= 1
 285          *   2 - if this block was evicted since we read it from
 286          *       dmu_tx_hold_free().
 287          */
 288         if (db->db_state != DB_CACHED)
 289                 (void) dbuf_read(db, NULL, DB_RF_MUST_SUCCEED);
 290
 291         /*
 292          * If we modify this indirect block, and we are not freeing the
 293          * dnode (!free_indirects), then this indirect block needs to get
 294          * written to disk by dbuf_write().  If it is dirty, we know it will
 295          * be written (otherwise, we would have incorrect on-disk state
 296          * because the space would be freed but still referenced by the BP
 297          * in this indirect block).  Therefore we VERIFY that it is
 298          * dirty.
 299          *
 300          * Our VERIFY covers some cases that do not actually have to be
 301          * dirty, but the open-context code happens to dirty.  E.g. if the
 302          * blocks we are freeing are all holes, because in that case, we
 303          * are only freeing part of this indirect block, so it is an
 304          * ancestor of the first or last block to be freed.  The first and
 305          * last L1 indirect blocks are always dirtied by dnode_free_range().
 306          */
 307         db_lock_type_t dblt = dmu_buf_lock_parent(db, RW_READER, FTAG);
 308         VERIFY(BP_GET_FILL(db->db_blkptr) == 0 || db->db_dirtycnt > 0);
 309         dmu_buf_unlock_parent(db, dblt, FTAG);
 310
 311         dbuf_release_bp(db);
 312         bp = db->db.db_data;
 313
 314         DB_DNODE_ENTER(db);
 315         dn = DB_DNODE(db);
 316         epbs = dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT;
 317         ASSERT3U(epbs, <, 31);
 318         shift = (db->db_level - 1) * epbs;
 319         dbstart = db->db_blkid << epbs;
 320         start = blkid >> shift;
 321         if (dbstart < start) {
 322                 bp += start - dbstart;
 323         } else {
 324                 start = dbstart;
 325         }
 326         dbend = ((db->db_blkid + 1) << epbs) - 1;
 327         end = (blkid + nblks - 1) >> shift;
 328         if (dbend <= end)
 329                 end = dbend;
 330
 331         ASSERT3U(start, <=, end);
 332
 333         if (db->db_level == 1) {
 334                 FREE_VERIFY(db, start, end, tx);
 335                 rw_enter(&db->db_rwlock, RW_WRITER);
 336                 free_blocks(dn, bp, end - start + 1, tx);
 337                 rw_exit(&db->db_rwlock);
 338         } else {
 339                 for (uint64_t id = start; id <= end; id++, bp++) {
 340                         if (BP_IS_HOLE(bp))
 341                                 continue;
 342                         rw_enter(&dn->dn_struct_rwlock, RW_READER);
 343                         VERIFY0(dbuf_hold_impl(dn, db->db_level - 1,
 344                             id, TRUE, FALSE, FTAG, &subdb));
 345                         rw_exit(&dn->dn_struct_rwlock);
 346                         ASSERT3P(bp, ==, subdb->db_blkptr);
 347
 348                         free_children(subdb, blkid, nblks, free_indirects, tx);
 349                         dbuf_rele(subdb, FTAG);
 350                 }
 351         }
 352
 353         if (free_indirects) {
 354                 rw_enter(&db->db_rwlock, RW_WRITER);
 355                 for (i = 0, bp = db->db.db_data; i < 1 << epbs; i++, bp++)
 356                         ASSERT(BP_IS_HOLE(bp));
 357                 memset(db->db.db_data, 0, db->db.db_size);
 358                 free_blocks(dn, db->db_blkptr, 1, tx);
 359                 rw_exit(&db->db_rwlock);
 360         }
 361
 362         DB_DNODE_EXIT(db);
 363         arc_buf_freeze(db->db_buf);
 364 }
 365
 366 /*
 367  * Traverse the indicated range of the provided file
 368  * and "free" all the blocks contained there.
 369  */
 370 static void
 371 dnode_sync_free_range_impl(dnode_t *dn, uint64_t blkid, uint64_t nblks,
 372     boolean_t free_indirects, dmu_tx_t *tx)
 373 {
 374         blkptr_t *bp = dn->dn_phys->dn_blkptr;
 375         int dnlevel = dn->dn_phys->dn_nlevels;
 376         boolean_t trunc = B_FALSE;
 377
 378         if (blkid > dn->dn_phys->dn_maxblkid)
 379                 return;
 380
 381         ASSERT(dn->dn_phys->dn_maxblkid < UINT64_MAX);
 382         if (blkid + nblks > dn->dn_phys->dn_maxblkid) {
 383                 nblks = dn->dn_phys->dn_maxblkid - blkid + 1;
 384                 trunc = B_TRUE;
 385         }
 386
 387         /* There are no indirect blocks in the object */
 388         if (dnlevel == 1) {
 389                 if (blkid >= dn->dn_phys->dn_nblkptr) {
 390                         /* this range was never made persistent */
 391                         return;
 392                 }
 393                 ASSERT3U(blkid + nblks, <=, dn->dn_phys->dn_nblkptr);
 394                 free_blocks(dn, bp + blkid, nblks, tx);
 395         } else {
 396                 int shift = (dnlevel - 1) *
 397                     (dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT);
 398                 int start = blkid >> shift;
 399                 int end = (blkid + nblks - 1) >> shift;
 400                 dmu_buf_impl_t *db;
 401
 402                 ASSERT(start < dn->dn_phys->dn_nblkptr);
 403                 bp += start;
 404                 for (int i = start; i <= end; i++, bp++) {
 405                         if (BP_IS_HOLE(bp))
 406                                 continue;
 407                         rw_enter(&dn->dn_struct_rwlock, RW_READER);
 408                         VERIFY0(dbuf_hold_impl(dn, dnlevel - 1, i,
 409                             TRUE, FALSE, FTAG, &db));
 410                         rw_exit(&dn->dn_struct_rwlock);
 411                         free_children(db, blkid, nblks, free_indirects, tx);
 412                         dbuf_rele(db, FTAG);
 413                 }
 414         }
 415
 416         /*
 417          * Do not truncate the maxblkid if we are performing a raw
 418          * receive. The raw receive sets the maxblkid manually and
 419          * must not be overridden. Usually, the last DRR_FREE record
 420          * will be at the maxblkid, because the source system sets
 421          * the maxblkid when truncating. However, if the last block
 422          * was freed by overwriting with zeros and being compressed
 423          * away to a hole, the source system will generate a DRR_FREE
 424          * record while leaving the maxblkid after the end of that
 425          * record. In this case we need to leave the maxblkid as
 426          * indicated in the DRR_OBJECT record, so that it matches the
 427          * source system, ensuring that the cryptographic hashes will
 428          * match.
 429          */
 430         if (trunc && !dn->dn_objset->os_raw_receive) {
 431                 uint64_t off __maybe_unused;
 432                 dn->dn_phys->dn_maxblkid = blkid == 0 ? 0 : blkid - 1;
 433
 434                 off = (dn->dn_phys->dn_maxblkid + 1) *
 435                     (dn->dn_phys->dn_datablkszsec << SPA_MINBLOCKSHIFT);
 436                 ASSERT(off < dn->dn_phys->dn_maxblkid ||
 437                     dn->dn_phys->dn_maxblkid == 0 ||
 438                     dnode_next_offset(dn, 0, &off, 1, 1, 0) != 0);
 439         }
 440 }
 441
 442 typedef struct dnode_sync_free_range_arg {
 443         dnode_t *dsfra_dnode;
 444         dmu_tx_t *dsfra_tx;
 445         boolean_t dsfra_free_indirects;
 446 } dnode_sync_free_range_arg_t;
 447
 448 static void
 449 dnode_sync_free_range(void *arg, uint64_t blkid, uint64_t nblks)
 450 {
 451         dnode_sync_free_range_arg_t *dsfra = arg;
 452         dnode_t *dn = dsfra->dsfra_dnode;
 453
 454         mutex_exit(&dn->dn_mtx);
 455         dnode_sync_free_range_impl(dn, blkid, nblks,
 456             dsfra->dsfra_free_indirects, dsfra->dsfra_tx);
 457         mutex_enter(&dn->dn_mtx);
 458 }
 459
 460 /*
 461  * Try to kick all the dnode's dbufs out of the cache...
 462  */
 463 void
 464 dnode_evict_dbufs(dnode_t *dn)
 465 {
 466         dmu_buf_impl_t *db_marker;
 467         dmu_buf_impl_t *db, *db_next;
 468
 469         db_marker = kmem_alloc(sizeof (dmu_buf_impl_t), KM_SLEEP);
 470
 471         mutex_enter(&dn->dn_dbufs_mtx);
 472         for (db = avl_first(&dn->dn_dbufs); db != NULL; db = db_next) {
 473
 474 #ifdef  ZFS_DEBUG
 475                 DB_DNODE_ENTER(db);
 476                 ASSERT3P(DB_DNODE(db), ==, dn);
 477                 DB_DNODE_EXIT(db);
 478 #endif  /* DEBUG */
 479
 480                 mutex_enter(&db->db_mtx);
 481                 if (db->db_state != DB_EVICTING &&
 482                     zfs_refcount_is_zero(&db->db_holds)) {
 483                         db_marker->db_level = db->db_level;
 484                         db_marker->db_blkid = db->db_blkid;
 485                         /*
 486                          * Insert a MARKER node with the same level and blkid.
 487                          * And to resolve any ties in dbuf_compare() use the
 488                          * pointer of the dbuf that we are evicting. Pass the
 489                          * address in db_parent.
 490                          */
 491                         db_marker->db_state = DB_MARKER;
 492                         db_marker->db_parent = (void *)((uintptr_t)db - 1);
 493                         avl_insert_here(&dn->dn_dbufs, db_marker, db,
 494                             AVL_BEFORE);
 495
 496                         /*
 497                          * We need to use the "marker" dbuf rather than
 498                          * simply getting the next dbuf, because
 499                          * dbuf_destroy() may actually remove multiple dbufs.
 500                          * It can call itself recursively on the parent dbuf,
 501                          * which may also be removed from dn_dbufs.  The code
 502                          * flow would look like:
 503                          *
 504                          * dbuf_destroy():
 505                          *   dnode_rele_and_unlock(parent_dbuf, evicting=TRUE):
 506                          *      if (!cacheable || pending_evict)
 507                          *        dbuf_destroy()
 508                          */
 509                         dbuf_destroy(db);
 510
 511                         db_next = AVL_NEXT(&dn->dn_dbufs, db_marker);
 512                         avl_remove(&dn->dn_dbufs, db_marker);
 513                 } else {
 514                         db->db_pending_evict = TRUE;
 515                         mutex_exit(&db->db_mtx);
 516                         db_next = AVL_NEXT(&dn->dn_dbufs, db);
 517                 }
 518         }
 519         mutex_exit(&dn->dn_dbufs_mtx);
 520
 521         kmem_free(db_marker, sizeof (dmu_buf_impl_t));
 522
 523         dnode_evict_bonus(dn);
 524 }
 525
 526 void
 527 dnode_evict_bonus(dnode_t *dn)
 528 {
 529         rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
 530         if (dn->dn_bonus != NULL) {
 531                 if (zfs_refcount_is_zero(&dn->dn_bonus->db_holds)) {
 532                         mutex_enter(&dn->dn_bonus->db_mtx);
 533                         dbuf_destroy(dn->dn_bonus);
 534                         dn->dn_bonus = NULL;
 535                 } else {
 536                         dn->dn_bonus->db_pending_evict = TRUE;
 537                 }
 538         }
 539         rw_exit(&dn->dn_struct_rwlock);
 540 }
 541
 542 static void
 543 dnode_undirty_dbufs(list_t *list)
 544 {
 545         dbuf_dirty_record_t *dr;
 546
 547         while ((dr = list_head(list))) {
 548                 dmu_buf_impl_t *db = dr->dr_dbuf;
 549                 uint64_t txg = dr->dr_txg;
 550
 551                 if (db->db_level != 0)
 552                         dnode_undirty_dbufs(&dr->dt.di.dr_children);
 553
 554                 mutex_enter(&db->db_mtx);
 555                 /* XXX - use dbuf_undirty()? */
 556                 list_remove(list, dr);
 557                 ASSERT(list_head(&db->db_dirty_records) == dr);
 558                 list_remove_head(&db->db_dirty_records);
 559                 ASSERT(list_is_empty(&db->db_dirty_records));
 560                 db->db_dirtycnt -= 1;
 561                 if (db->db_level == 0) {
 562                         ASSERT(db->db_blkid == DMU_BONUS_BLKID ||
 563                             dr->dt.dl.dr_data == db->db_buf);
 564                         dbuf_unoverride(dr);
 565                 } else {
 566                         mutex_destroy(&dr->dt.di.dr_mtx);
 567                         list_destroy(&dr->dt.di.dr_children);
 568                 }
 569                 kmem_free(dr, sizeof (dbuf_dirty_record_t));
 570                 dbuf_rele_and_unlock(db, (void *)(uintptr_t)txg, B_FALSE);
 571         }
 572 }
 573
 574 static void
 575 dnode_sync_free(dnode_t *dn, dmu_tx_t *tx)
 576 {
 577         int txgoff = tx->tx_txg & TXG_MASK;
 578
 579         ASSERT(dmu_tx_is_syncing(tx));
 580
 581         /*
 582          * Our contents should have been freed in dnode_sync() by the
 583          * free range record inserted by the caller of dnode_free().
 584          */
 585         ASSERT0(DN_USED_BYTES(dn->dn_phys));
 586         ASSERT(BP_IS_HOLE(dn->dn_phys->dn_blkptr));
 587
 588         dnode_undirty_dbufs(&dn->dn_dirty_records[txgoff]);
 589         dnode_evict_dbufs(dn);
 590
 591         /*
 592          * XXX - It would be nice to assert this, but we may still
 593          * have residual holds from async evictions from the arc...
 594          *
 595          * zfs_obj_to_path() also depends on this being
 596          * commented out.
 597          *
 598          * ASSERT3U(zfs_refcount_count(&dn->dn_holds), ==, 1);
 599          */
 600
 601         /* Undirty next bits */
 602         dn->dn_next_nlevels[txgoff] = 0;
 603         dn->dn_next_indblkshift[txgoff] = 0;
 604         dn->dn_next_blksz[txgoff] = 0;
 605         dn->dn_next_maxblkid[txgoff] = 0;
 606
 607         /* ASSERT(blkptrs are zero); */
 608         ASSERT(dn->dn_phys->dn_type != DMU_OT_NONE);
 609         ASSERT(dn->dn_type != DMU_OT_NONE);
 610
 611         ASSERT(dn->dn_free_txg > 0);
 612         if (dn->dn_allocated_txg != dn->dn_free_txg)
 613                 dmu_buf_will_dirty(&dn->dn_dbuf->db, tx);
 614         memset(dn->dn_phys, 0, sizeof (dnode_phys_t) * dn->dn_num_slots);
 615         dnode_free_interior_slots(dn);
 616
 617         mutex_enter(&dn->dn_mtx);
 618         dn->dn_type = DMU_OT_NONE;
 619         dn->dn_maxblkid = 0;
 620         dn->dn_allocated_txg = 0;
 621         dn->dn_free_txg = 0;
 622         dn->dn_have_spill = B_FALSE;
 623         dn->dn_num_slots = 1;
 624         mutex_exit(&dn->dn_mtx);
 625
 626         ASSERT(dn->dn_object != DMU_META_DNODE_OBJECT);
 627
 628         dnode_rele(dn, (void *)(uintptr_t)tx->tx_txg);
 629         /*
 630          * Now that we've released our hold, the dnode may
 631          * be evicted, so we mustn't access it.
 632          */
 633 }
 634
 635 /*
 636  * Write out the dnode's dirty buffers.
 637  * Does not wait for zio completions.
 638  */
 639 void
 640 dnode_sync(dnode_t *dn, dmu_tx_t *tx)
 641 {
 642         objset_t *os = dn->dn_objset;
 643         dnode_phys_t *dnp = dn->dn_phys;
 644         int txgoff = tx->tx_txg & TXG_MASK;
 645         list_t *list = &dn->dn_dirty_records[txgoff];
 646         static const dnode_phys_t zerodn __maybe_unused = { 0 };
 647         boolean_t kill_spill = B_FALSE;
 648
 649         ASSERT(dmu_tx_is_syncing(tx));
 650         ASSERT(dnp->dn_type != DMU_OT_NONE || dn->dn_allocated_txg);
 651         ASSERT(dnp->dn_type != DMU_OT_NONE ||
 652             memcmp(dnp, &zerodn, DNODE_MIN_SIZE) == 0);
 653         DNODE_VERIFY(dn);
 654
 655         ASSERT(dn->dn_dbuf == NULL || arc_released(dn->dn_dbuf->db_buf));
 656
 657         /*
 658          * Do user accounting if it is enabled and this is not
 659          * an encrypted receive.
 660          */
 661         if (dmu_objset_userused_enabled(os) &&
 662             !DMU_OBJECT_IS_SPECIAL(dn->dn_object) &&
 663             (!os->os_encrypted || !dmu_objset_is_receiving(os))) {
 664                 mutex_enter(&dn->dn_mtx);
 665                 dn->dn_oldused = DN_USED_BYTES(dn->dn_phys);
 666                 dn->dn_oldflags = dn->dn_phys->dn_flags;
 667                 dn->dn_phys->dn_flags |= DNODE_FLAG_USERUSED_ACCOUNTED;
 668                 if (dmu_objset_userobjused_enabled(dn->dn_objset))
 669                         dn->dn_phys->dn_flags |=
 670                             DNODE_FLAG_USEROBJUSED_ACCOUNTED;
 671                 mutex_exit(&dn->dn_mtx);
 672                 dmu_objset_userquota_get_ids(dn, B_FALSE, tx);
 673         } else if (!(os->os_encrypted && dmu_objset_is_receiving(os))) {
 674                 /*
 675                  * Once we account for it, we should always account for it,
 676                  * except for the case of a raw receive. We will not be able
 677                  * to account for it until the receiving dataset has been
 678                  * mounted.
 679                  */
 680                 ASSERT(!(dn->dn_phys->dn_flags &
 681                     DNODE_FLAG_USERUSED_ACCOUNTED));
 682                 ASSERT(!(dn->dn_phys->dn_flags &
 683                     DNODE_FLAG_USEROBJUSED_ACCOUNTED));
 684         }
 685
 686         mutex_enter(&dn->dn_mtx);
 687         if (dn->dn_allocated_txg == tx->tx_txg) {
 688                 /* The dnode is newly allocated or reallocated */
 689                 if (dnp->dn_type == DMU_OT_NONE) {
 690                         /* this is a first alloc, not a realloc */
 691                         dnp->dn_nlevels = 1;
 692                         dnp->dn_nblkptr = dn->dn_nblkptr;
 693                 }
 694
 695                 dnp->dn_type = dn->dn_type;
 696                 dnp->dn_bonustype = dn->dn_bonustype;
 697                 dnp->dn_bonuslen = dn->dn_bonuslen;
 698         }
 699
 700         dnp->dn_extra_slots = dn->dn_num_slots - 1;
 701
 702         ASSERT(dnp->dn_nlevels > 1 ||
 703             BP_IS_HOLE(&dnp->dn_blkptr[0]) ||
 704             BP_IS_EMBEDDED(&dnp->dn_blkptr[0]) ||
 705             BP_GET_LSIZE(&dnp->dn_blkptr[0]) ==
 706             dnp->dn_datablkszsec << SPA_MINBLOCKSHIFT);
 707         ASSERT(dnp->dn_nlevels < 2 ||
 708             BP_IS_HOLE(&dnp->dn_blkptr[0]) ||
 709             BP_GET_LSIZE(&dnp->dn_blkptr[0]) == 1 << dnp->dn_indblkshift);
 710
 711         if (dn->dn_next_type[txgoff] != 0) {
 712                 dnp->dn_type = dn->dn_type;
 713                 dn->dn_next_type[txgoff] = 0;
 714         }
 715
 716         if (dn->dn_next_blksz[txgoff] != 0) {
 717                 ASSERT(P2PHASE(dn->dn_next_blksz[txgoff],
 718                     SPA_MINBLOCKSIZE) == 0);
 719                 ASSERT(BP_IS_HOLE(&dnp->dn_blkptr[0]) ||
 720                     dn->dn_maxblkid == 0 || list_head(list) != NULL ||
 721                     dn->dn_next_blksz[txgoff] >> SPA_MINBLOCKSHIFT ==
 722                     dnp->dn_datablkszsec ||
 723                     !range_tree_is_empty(dn->dn_free_ranges[txgoff]));
 724                 dnp->dn_datablkszsec =
 725                     dn->dn_next_blksz[txgoff] >> SPA_MINBLOCKSHIFT;
 726                 dn->dn_next_blksz[txgoff] = 0;
 727         }
 728
 729         if (dn->dn_next_bonuslen[txgoff] != 0) {
 730                 if (dn->dn_next_bonuslen[txgoff] == DN_ZERO_BONUSLEN)
 731                         dnp->dn_bonuslen = 0;
 732                 else
 733                         dnp->dn_bonuslen = dn->dn_next_bonuslen[txgoff];
 734                 ASSERT(dnp->dn_bonuslen <=
 735                     DN_SLOTS_TO_BONUSLEN(dnp->dn_extra_slots + 1));
 736                 dn->dn_next_bonuslen[txgoff] = 0;
 737         }
 738
 739         if (dn->dn_next_bonustype[txgoff] != 0) {
 740                 ASSERT(DMU_OT_IS_VALID(dn->dn_next_bonustype[txgoff]));
 741                 dnp->dn_bonustype = dn->dn_next_bonustype[txgoff];
 742                 dn->dn_next_bonustype[txgoff] = 0;
 743         }
 744
 745         boolean_t freeing_dnode = dn->dn_free_txg > 0 &&
 746             dn->dn_free_txg <= tx->tx_txg;
 747
 748         /*
 749          * Remove the spill block if we have been explicitly asked to
 750          * remove it, or if the object is being removed.
 751          */
 752         if (dn->dn_rm_spillblk[txgoff] || freeing_dnode) {
 753                 if (dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR)
 754                         kill_spill = B_TRUE;
 755                 dn->dn_rm_spillblk[txgoff] = 0;
 756         }
 757
 758         if (dn->dn_next_indblkshift[txgoff] != 0) {
 759                 ASSERT(dnp->dn_nlevels == 1);
 760                 dnp->dn_indblkshift = dn->dn_next_indblkshift[txgoff];
 761                 dn->dn_next_indblkshift[txgoff] = 0;
 762         }
 763
 764         /*
 765          * Just take the live (open-context) values for checksum and compress.
 766          * Strictly speaking it's a future leak, but nothing bad happens if we
 767          * start using the new checksum or compress algorithm a little early.
 768          */
 769         dnp->dn_checksum = dn->dn_checksum;
 770         dnp->dn_compress = dn->dn_compress;
 771
 772         mutex_exit(&dn->dn_mtx);
 773
 774         if (kill_spill) {
 775                 free_blocks(dn, DN_SPILL_BLKPTR(dn->dn_phys), 1, tx);
 776                 mutex_enter(&dn->dn_mtx);
 777                 dnp->dn_flags &= ~DNODE_FLAG_SPILL_BLKPTR;
 778                 mutex_exit(&dn->dn_mtx);
 779         }
 780
 781         /* process all the "freed" ranges in the file */
 782         if (dn->dn_free_ranges[txgoff] != NULL) {
 783                 dnode_sync_free_range_arg_t dsfra;
 784                 dsfra.dsfra_dnode = dn;
 785                 dsfra.dsfra_tx = tx;
 786                 dsfra.dsfra_free_indirects = freeing_dnode;
 787                 mutex_enter(&dn->dn_mtx);
 788                 if (freeing_dnode) {
 789                         ASSERT(range_tree_contains(dn->dn_free_ranges[txgoff],
 790                             0, dn->dn_maxblkid + 1));
 791                 }
 792                 /*
 793                  * Because dnode_sync_free_range() must drop dn_mtx during its
 794                  * processing, using it as a callback to range_tree_vacate() is
 795                  * not safe.  No other operations (besides destroy) are allowed
 796                  * once range_tree_vacate() has begun, and dropping dn_mtx
 797                  * would leave a window open for another thread to observe that
 798                  * invalid (and unsafe) state.
 799                  */
 800                 range_tree_walk(dn->dn_free_ranges[txgoff],
 801                     dnode_sync_free_range, &dsfra);
 802                 range_tree_vacate(dn->dn_free_ranges[txgoff], NULL, NULL);
 803                 range_tree_destroy(dn->dn_free_ranges[txgoff]);
 804                 dn->dn_free_ranges[txgoff] = NULL;
 805                 mutex_exit(&dn->dn_mtx);
 806         }
 807
 808         if (freeing_dnode) {
 809                 dn->dn_objset->os_freed_dnodes++;
 810                 dnode_sync_free(dn, tx);
 811                 return;
 812         }
 813
 814         if (dn->dn_num_slots > DNODE_MIN_SLOTS) {
 815                 dsl_dataset_t *ds = dn->dn_objset->os_dsl_dataset;
 816                 mutex_enter(&ds->ds_lock);
 817                 ds->ds_feature_activation[SPA_FEATURE_LARGE_DNODE] =
 818                     (void *)B_TRUE;
 819                 mutex_exit(&ds->ds_lock);
 820         }
 821
 822         if (dn->dn_next_nlevels[txgoff]) {
 823                 dnode_increase_indirection(dn, tx);
 824                 dn->dn_next_nlevels[txgoff] = 0;
 825         }
 826
 827         /*
 828          * This must be done after dnode_sync_free_range()
 829          * and dnode_increase_indirection(). See dnode_new_blkid()
 830          * for an explanation of the high bit being set.
 831          */
 832         if (dn->dn_next_maxblkid[txgoff]) {
 833                 mutex_enter(&dn->dn_mtx);
 834                 dnp->dn_maxblkid =
 835                     dn->dn_next_maxblkid[txgoff] & ~DMU_NEXT_MAXBLKID_SET;
 836                 dn->dn_next_maxblkid[txgoff] = 0;
 837                 mutex_exit(&dn->dn_mtx);
 838         }
 839
 840         if (dn->dn_next_nblkptr[txgoff]) {
 841                 /* this should only happen on a realloc */
 842                 ASSERT(dn->dn_allocated_txg == tx->tx_txg);
 843                 if (dn->dn_next_nblkptr[txgoff] > dnp->dn_nblkptr) {
 844                         /* zero the new blkptrs we are gaining */
 845                         memset(dnp->dn_blkptr + dnp->dn_nblkptr, 0,
 846                             sizeof (blkptr_t) *
 847                             (dn->dn_next_nblkptr[txgoff] - dnp->dn_nblkptr));
 848 #ifdef ZFS_DEBUG
 849                 } else {
 850                         int i;
 851                         ASSERT(dn->dn_next_nblkptr[txgoff] < dnp->dn_nblkptr);
 852                         /* the blkptrs we are losing better be unallocated */
 853                         for (i = 0; i < dnp->dn_nblkptr; i++) {
 854                                 if (i >= dn->dn_next_nblkptr[txgoff])
 855                                         ASSERT(BP_IS_HOLE(&dnp->dn_blkptr[i]));
 856                         }
 857 #endif
 858                 }
 859                 mutex_enter(&dn->dn_mtx);
 860                 dnp->dn_nblkptr = dn->dn_next_nblkptr[txgoff];
 861                 dn->dn_next_nblkptr[txgoff] = 0;
 862                 mutex_exit(&dn->dn_mtx);
 863         }
 864
 865         dbuf_sync_list(list, dn->dn_phys->dn_nlevels - 1, tx);
 866
 867         if (!DMU_OBJECT_IS_SPECIAL(dn->dn_object)) {
 868                 ASSERT3P(list_head(list), ==, NULL);
 869                 dnode_rele(dn, (void *)(uintptr_t)tx->tx_txg);
 870         }
 871
 872         ASSERT3U(dnp->dn_bonuslen, <=, DN_MAX_BONUS_LEN(dnp));
 873
 874         /*
 875          * Although we have dropped our reference to the dnode, it
 876          * can't be evicted until its written, and we haven't yet
 877          * initiated the IO for the dnode's dbuf.  Additionally, the caller
 878          * has already added a reference to the dnode because it's on the
 879          * os_synced_dnodes list.
 880          */
 881 }