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 2007 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 void 113 free_blocks(dnode_t *dn, blkptr_t *bp, int num, dmu_tx_t *tx) 114 { 115 objset_impl_t *os = dn->dn_objset; 116 uint64_t bytesfreed = 0; 117 int i; 118 119 dprintf("os=%p obj=%llx num=%d\n", os, dn->dn_object, num); 120 121 for (i = 0; i < num; i++, bp++) { 122 if (BP_IS_HOLE(bp)) 123 continue; 124 125 bytesfreed += bp_get_dasize(os->os_spa, bp); 126 ASSERT3U(bytesfreed, <=, DN_USED_BYTES(dn->dn_phys)); 127 dsl_dataset_block_kill(os->os_dsl_dataset, bp, dn->dn_zio, tx); 128 bzero(bp, sizeof (blkptr_t)); 129 } 130 dnode_diduse_space(dn, -bytesfreed); 131 } 132 133 #ifdef ZFS_DEBUG 134 static void 135 free_verify(dmu_buf_impl_t *db, uint64_t start, uint64_t end, dmu_tx_t *tx) 136 { 137 int off, num; 138 int i, err, epbs; 139 uint64_t txg = tx->tx_txg; 140 141 epbs = db->db_dnode->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT; 142 off = start - (db->db_blkid * 1<<epbs); 143 num = end - start + 1; 144 145 ASSERT3U(off, >=, 0); 146 ASSERT3U(num, >=, 0); 147 ASSERT3U(db->db_level, >, 0); 148 ASSERT3U(db->db.db_size, ==, 1<<db->db_dnode->dn_phys->dn_indblkshift); 149 ASSERT3U(off+num, <=, db->db.db_size >> SPA_BLKPTRSHIFT); 150 ASSERT(db->db_blkptr != NULL); 151 152 for (i = off; i < off+num; i++) { 153 uint64_t *buf; 154 dmu_buf_impl_t *child; 155 dbuf_dirty_record_t *dr; 156 int j; 157 158 ASSERT(db->db_level == 1); 159 160 rw_enter(&db->db_dnode->dn_struct_rwlock, RW_READER); 161 err = dbuf_hold_impl(db->db_dnode, db->db_level-1, 162 (db->db_blkid << epbs) + i, TRUE, FTAG, &child); 163 rw_exit(&db->db_dnode->dn_struct_rwlock); 164 if (err == ENOENT) 165 continue; 166 ASSERT(err == 0); 167 ASSERT(child->db_level == 0); 168 dr = child->db_last_dirty; 169 while (dr && dr->dr_txg > txg) 170 dr = dr->dr_next; 171 ASSERT(dr == NULL || dr->dr_txg == txg); 172 173 /* data_old better be zeroed */ 174 if (dr) { 175 buf = dr->dt.dl.dr_data->b_data; 176 for (j = 0; j < child->db.db_size >> 3; j++) { 177 if (buf[j] != 0) { 178 panic("freed data not zero: " 179 "child=%p i=%d off=%d num=%d\n", 180 child, i, off, num); 181 } 182 } 183 } 184 185 /* 186 * db_data better be zeroed unless it's dirty in a 187 * future txg. 188 */ 189 mutex_enter(&child->db_mtx); 190 buf = child->db.db_data; 191 if (buf != NULL && child->db_state != DB_FILL && 192 child->db_last_dirty == NULL) { 193 for (j = 0; j < child->db.db_size >> 3; j++) { 194 if (buf[j] != 0) { 195 panic("freed data not zero: " 196 "child=%p i=%d off=%d num=%d\n", 197 child, i, off, num); 198 } 199 } 200 } 201 mutex_exit(&child->db_mtx); 202 203 dbuf_rele(child, FTAG); 204 } 205 } 206 #endif 207 208 static int 209 free_children(dmu_buf_impl_t *db, uint64_t blkid, uint64_t nblks, int trunc, 210 dmu_tx_t *tx) 211 { 212 dnode_t *dn = db->db_dnode; 213 blkptr_t *bp; 214 dmu_buf_impl_t *subdb; 215 uint64_t start, end, dbstart, dbend, i; 216 int epbs, shift, err; 217 int all = TRUE; 218 219 (void) dbuf_read(db, NULL, DB_RF_MUST_SUCCEED); 220 arc_release(db->db_buf, db); 221 bp = (blkptr_t *)db->db.db_data; 222 223 epbs = db->db_dnode->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT; 224 shift = (db->db_level - 1) * epbs; 225 dbstart = db->db_blkid << epbs; 226 start = blkid >> shift; 227 if (dbstart < start) { 228 bp += start - dbstart; 229 all = FALSE; 230 } else { 231 start = dbstart; 232 } 233 dbend = ((db->db_blkid + 1) << epbs) - 1; 234 end = (blkid + nblks - 1) >> shift; 235 if (dbend <= end) 236 end = dbend; 237 else if (all) 238 all = trunc; 239 ASSERT3U(start, <=, end); 240 241 if (db->db_level == 1) { 242 FREE_VERIFY(db, start, end, tx); 243 free_blocks(dn, bp, end-start+1, tx); 244 arc_buf_freeze(db->db_buf); 245 ASSERT(all || db->db_last_dirty); 246 return (all); 247 } 248 249 for (i = start; i <= end; i++, bp++) { 250 if (BP_IS_HOLE(bp)) 251 continue; 252 rw_enter(&dn->dn_struct_rwlock, RW_READER); 253 err = dbuf_hold_impl(dn, db->db_level-1, i, TRUE, FTAG, &subdb); 254 ASSERT3U(err, ==, 0); 255 rw_exit(&dn->dn_struct_rwlock); 256 257 if (free_children(subdb, blkid, nblks, trunc, tx)) { 258 ASSERT3P(subdb->db_blkptr, ==, bp); 259 free_blocks(dn, bp, 1, tx); 260 } else { 261 all = FALSE; 262 } 263 dbuf_rele(subdb, FTAG); 264 } 265 arc_buf_freeze(db->db_buf); 266 #ifdef ZFS_DEBUG 267 bp -= (end-start)+1; 268 for (i = start; i <= end; i++, bp++) { 269 if (i == start && blkid != 0) 270 continue; 271 else if (i == end && !trunc) 272 continue; 273 ASSERT3U(bp->blk_birth, ==, 0); 274 } 275 #endif 276 ASSERT(all || db->db_last_dirty); 277 return (all); 278 } 279 280 /* 281 * free_range: Traverse the indicated range of the provided file 282 * and "free" all the blocks contained there. 283 */ 284 static void 285 dnode_sync_free_range(dnode_t *dn, uint64_t blkid, uint64_t nblks, dmu_tx_t *tx) 286 { 287 blkptr_t *bp = dn->dn_phys->dn_blkptr; 288 dmu_buf_impl_t *db; 289 int trunc, start, end, shift, i, err; 290 int dnlevel = dn->dn_phys->dn_nlevels; 291 292 if (blkid > dn->dn_phys->dn_maxblkid) 293 return; 294 295 ASSERT(dn->dn_phys->dn_maxblkid < UINT64_MAX); 296 trunc = blkid + nblks > dn->dn_phys->dn_maxblkid; 297 if (trunc) 298 nblks = dn->dn_phys->dn_maxblkid - blkid + 1; 299 300 /* There are no indirect blocks in the object */ 301 if (dnlevel == 1) { 302 if (blkid >= dn->dn_phys->dn_nblkptr) { 303 /* this range was never made persistent */ 304 return; 305 } 306 ASSERT3U(blkid + nblks, <=, dn->dn_phys->dn_nblkptr); 307 free_blocks(dn, bp + blkid, nblks, tx); 308 if (trunc) { 309 uint64_t off = (dn->dn_phys->dn_maxblkid + 1) * 310 (dn->dn_phys->dn_datablkszsec << SPA_MINBLOCKSHIFT); 311 dn->dn_phys->dn_maxblkid = (blkid ? blkid - 1 : 0); 312 ASSERT(off < dn->dn_phys->dn_maxblkid || 313 dn->dn_phys->dn_maxblkid == 0 || 314 dnode_next_offset(dn, FALSE, &off, 315 1, 1, 0) != 0); 316 } 317 return; 318 } 319 320 shift = (dnlevel - 1) * (dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT); 321 start = blkid >> shift; 322 ASSERT(start < dn->dn_phys->dn_nblkptr); 323 end = (blkid + nblks - 1) >> shift; 324 bp += start; 325 for (i = start; i <= end; i++, bp++) { 326 if (BP_IS_HOLE(bp)) 327 continue; 328 rw_enter(&dn->dn_struct_rwlock, RW_READER); 329 err = dbuf_hold_impl(dn, dnlevel-1, i, TRUE, FTAG, &db); 330 ASSERT3U(err, ==, 0); 331 rw_exit(&dn->dn_struct_rwlock); 332 333 if (free_children(db, blkid, nblks, trunc, tx)) { 334 ASSERT3P(db->db_blkptr, ==, bp); 335 free_blocks(dn, bp, 1, tx); 336 } 337 dbuf_rele(db, FTAG); 338 } 339 if (trunc) { 340 uint64_t off = (dn->dn_phys->dn_maxblkid + 1) * 341 (dn->dn_phys->dn_datablkszsec << SPA_MINBLOCKSHIFT); 342 dn->dn_phys->dn_maxblkid = (blkid ? blkid - 1 : 0); 343 ASSERT(off < dn->dn_phys->dn_maxblkid || 344 dn->dn_phys->dn_maxblkid == 0 || 345 dnode_next_offset(dn, FALSE, &off, 1, 1, 0) != 0); 346 } 347 } 348 349 /* 350 * Try to kick all the dnodes dbufs out of the cache... 351 */ 352 int 353 dnode_evict_dbufs(dnode_t *dn, int try) 354 { 355 int progress; 356 int pass = 0; 357 358 do { 359 dmu_buf_impl_t *db, marker; 360 int evicting = FALSE; 361 362 progress = FALSE; 363 mutex_enter(&dn->dn_dbufs_mtx); 364 list_insert_tail(&dn->dn_dbufs, &marker); 365 db = list_head(&dn->dn_dbufs); 366 for (; db != ▮ db = list_head(&dn->dn_dbufs)) { 367 list_remove(&dn->dn_dbufs, db); 368 list_insert_tail(&dn->dn_dbufs, db); 369 ASSERT3P(db->db_dnode, ==, dn); 370 371 mutex_enter(&db->db_mtx); 372 if (db->db_state == DB_EVICTING) { 373 progress = TRUE; 374 evicting = TRUE; 375 mutex_exit(&db->db_mtx); 376 } else if (refcount_is_zero(&db->db_holds)) { 377 progress = TRUE; 378 ASSERT(!arc_released(db->db_buf)); 379 dbuf_clear(db); /* exits db_mtx for us */ 380 } else { 381 mutex_exit(&db->db_mtx); 382 } 383 384 } 385 list_remove(&dn->dn_dbufs, &marker); 386 /* 387 * NB: we need to drop dn_dbufs_mtx between passes so 388 * that any DB_EVICTING dbufs can make progress. 389 * Ideally, we would have some cv we could wait on, but 390 * since we don't, just wait a bit to give the other 391 * thread a chance to run. 392 */ 393 mutex_exit(&dn->dn_dbufs_mtx); 394 if (evicting) 395 delay(1); 396 pass++; 397 ASSERT(pass < 100); /* sanity check */ 398 } while (progress); 399 400 /* 401 * This function works fine even if it can't evict everything. 402 * If were only asked to try to evict everything then 403 * return an error if we can't. Otherwise panic as the caller 404 * expects total eviction. 405 */ 406 if (list_head(&dn->dn_dbufs) != NULL) { 407 if (try) { 408 return (1); 409 } else { 410 panic("dangling dbufs (dn=%p, dbuf=%p)\n", 411 dn, list_head(&dn->dn_dbufs)); 412 } 413 } 414 415 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 416 if (dn->dn_bonus && refcount_is_zero(&dn->dn_bonus->db_holds)) { 417 mutex_enter(&dn->dn_bonus->db_mtx); 418 dbuf_evict(dn->dn_bonus); 419 dn->dn_bonus = NULL; 420 } 421 rw_exit(&dn->dn_struct_rwlock); 422 return (0); 423 } 424 425 static void 426 dnode_undirty_dbufs(list_t *list) 427 { 428 dbuf_dirty_record_t *dr; 429 430 while (dr = list_head(list)) { 431 dmu_buf_impl_t *db = dr->dr_dbuf; 432 uint64_t txg = dr->dr_txg; 433 434 mutex_enter(&db->db_mtx); 435 /* XXX - use dbuf_undirty()? */ 436 list_remove(list, dr); 437 ASSERT(db->db_last_dirty == dr); 438 db->db_last_dirty = NULL; 439 db->db_dirtycnt -= 1; 440 if (db->db_level == 0) { 441 ASSERT(db->db_blkid == DB_BONUS_BLKID || 442 dr->dt.dl.dr_data == db->db_buf); 443 dbuf_unoverride(dr); 444 mutex_exit(&db->db_mtx); 445 } else { 446 mutex_exit(&db->db_mtx); 447 dnode_undirty_dbufs(&dr->dt.di.dr_children); 448 } 449 kmem_free(dr, sizeof (dbuf_dirty_record_t)); 450 dbuf_rele(db, (void *)(uintptr_t)txg); 451 } 452 } 453 454 static void 455 dnode_sync_free(dnode_t *dn, dmu_tx_t *tx) 456 { 457 int txgoff = tx->tx_txg & TXG_MASK; 458 459 ASSERT(dmu_tx_is_syncing(tx)); 460 461 dnode_undirty_dbufs(&dn->dn_dirty_records[txgoff]); 462 (void) dnode_evict_dbufs(dn, 0); 463 ASSERT3P(list_head(&dn->dn_dbufs), ==, NULL); 464 465 /* 466 * XXX - It would be nice to assert this, but we may still 467 * have residual holds from async evictions from the arc... 468 * 469 * zfs_obj_to_path() also depends on this being 470 * commented out. 471 * 472 * ASSERT3U(refcount_count(&dn->dn_holds), ==, 1); 473 */ 474 475 /* Undirty next bits */ 476 dn->dn_next_nlevels[txgoff] = 0; 477 dn->dn_next_indblkshift[txgoff] = 0; 478 dn->dn_next_blksz[txgoff] = 0; 479 480 /* free up all the blocks in the file. */ 481 dnode_sync_free_range(dn, 0, dn->dn_phys->dn_maxblkid+1, tx); 482 ASSERT3U(DN_USED_BYTES(dn->dn_phys), ==, 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 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_indblkshift[txgoff]) { 569 ASSERT(dnp->dn_nlevels == 1); 570 dnp->dn_indblkshift = dn->dn_next_indblkshift[txgoff]; 571 dn->dn_next_indblkshift[txgoff] = 0; 572 } 573 574 /* 575 * Just take the live (open-context) values for checksum and compress. 576 * Strictly speaking it's a future leak, but nothing bad happens if we 577 * start using the new checksum or compress algorithm a little early. 578 */ 579 dnp->dn_checksum = dn->dn_checksum; 580 dnp->dn_compress = dn->dn_compress; 581 582 mutex_exit(&dn->dn_mtx); 583 584 /* process all the "freed" ranges in the file */ 585 if (dn->dn_free_txg == 0 || dn->dn_free_txg > tx->tx_txg) { 586 for (rp = avl_last(&dn->dn_ranges[txgoff]); rp != NULL; 587 rp = AVL_PREV(&dn->dn_ranges[txgoff], rp)) 588 dnode_sync_free_range(dn, 589 rp->fr_blkid, rp->fr_nblks, tx); 590 } 591 mutex_enter(&dn->dn_mtx); 592 for (rp = avl_first(&dn->dn_ranges[txgoff]); rp; ) { 593 free_range_t *last = rp; 594 rp = AVL_NEXT(&dn->dn_ranges[txgoff], rp); 595 avl_remove(&dn->dn_ranges[txgoff], last); 596 kmem_free(last, sizeof (free_range_t)); 597 } 598 mutex_exit(&dn->dn_mtx); 599 600 if (dn->dn_free_txg > 0 && dn->dn_free_txg <= tx->tx_txg) { 601 dnode_sync_free(dn, tx); 602 return; 603 } 604 605 if (dn->dn_next_nlevels[txgoff]) { 606 dnode_increase_indirection(dn, tx); 607 dn->dn_next_nlevels[txgoff] = 0; 608 } 609 610 dbuf_sync_list(list, tx); 611 612 if (dn->dn_object != DMU_META_DNODE_OBJECT) { 613 ASSERT3P(list_head(list), ==, NULL); 614 dnode_rele(dn, (void *)(uintptr_t)tx->tx_txg); 615 } 616 617 /* 618 * Although we have dropped our reference to the dnode, it 619 * can't be evicted until its written, and we haven't yet 620 * initiated the IO for the dnode's dbuf. 621 */ 622 } 623