1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 /* 22 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. 23 * Copyright (c) 2012, 2015 by Delphix. All rights reserved. 24 * Copyright (c) 2014 Spectra Logic Corporation, All rights reserved. 25 * Copyright (c) 2014 Integros [integros.com] 26 */ 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_impl.h> 33 #include <sys/dmu_tx.h> 34 #include <sys/dmu_objset.h> 35 #include <sys/dsl_dir.h> 36 #include <sys/dsl_dataset.h> 37 #include <sys/spa.h> 38 #include <sys/zio.h> 39 #include <sys/dmu_zfetch.h> 40 #include <sys/range_tree.h> 41 42 static kmem_cache_t *dnode_cache; 43 /* 44 * Define DNODE_STATS to turn on statistic gathering. By default, it is only 45 * turned on when DEBUG is also defined. 46 */ 47 #ifdef DEBUG 48 #define DNODE_STATS 49 #endif /* DEBUG */ 50 51 #ifdef DNODE_STATS 52 #define DNODE_STAT_ADD(stat) ((stat)++) 53 #else 54 #define DNODE_STAT_ADD(stat) /* nothing */ 55 #endif /* DNODE_STATS */ 56 57 static dnode_phys_t dnode_phys_zero; 58 59 int zfs_default_bs = SPA_MINBLOCKSHIFT; 60 int zfs_default_ibs = DN_MAX_INDBLKSHIFT; 61 62 static kmem_cbrc_t dnode_move(void *, void *, size_t, void *); 63 64 static int 65 dbuf_compare(const void *x1, const void *x2) 66 { 67 const dmu_buf_impl_t *d1 = x1; 68 const dmu_buf_impl_t *d2 = x2; 69 70 if (d1->db_level < d2->db_level) { 71 return (-1); 72 } 73 if (d1->db_level > d2->db_level) { 74 return (1); 75 } 76 77 if (d1->db_blkid < d2->db_blkid) { 78 return (-1); 79 } 80 if (d1->db_blkid > d2->db_blkid) { 81 return (1); 82 } 83 84 if (d1->db_state == DB_SEARCH) { 85 ASSERT3S(d2->db_state, !=, DB_SEARCH); 86 return (-1); 87 } else if (d2->db_state == DB_SEARCH) { 88 ASSERT3S(d1->db_state, !=, DB_SEARCH); 89 return (1); 90 } 91 92 if ((uintptr_t)d1 < (uintptr_t)d2) { 93 return (-1); 94 } 95 if ((uintptr_t)d1 > (uintptr_t)d2) { 96 return (1); 97 } 98 return (0); 99 } 100 101 /* ARGSUSED */ 102 static int 103 dnode_cons(void *arg, void *unused, int kmflag) 104 { 105 dnode_t *dn = arg; 106 int i; 107 108 rw_init(&dn->dn_struct_rwlock, NULL, RW_DEFAULT, NULL); 109 mutex_init(&dn->dn_mtx, NULL, MUTEX_DEFAULT, NULL); 110 mutex_init(&dn->dn_dbufs_mtx, NULL, MUTEX_DEFAULT, NULL); 111 cv_init(&dn->dn_notxholds, NULL, CV_DEFAULT, NULL); 112 113 /* 114 * Every dbuf has a reference, and dropping a tracked reference is 115 * O(number of references), so don't track dn_holds. 116 */ 117 refcount_create_untracked(&dn->dn_holds); 118 refcount_create(&dn->dn_tx_holds); 119 list_link_init(&dn->dn_link); 120 121 bzero(&dn->dn_next_nblkptr[0], sizeof (dn->dn_next_nblkptr)); 122 bzero(&dn->dn_next_nlevels[0], sizeof (dn->dn_next_nlevels)); 123 bzero(&dn->dn_next_indblkshift[0], sizeof (dn->dn_next_indblkshift)); 124 bzero(&dn->dn_next_bonustype[0], sizeof (dn->dn_next_bonustype)); 125 bzero(&dn->dn_rm_spillblk[0], sizeof (dn->dn_rm_spillblk)); 126 bzero(&dn->dn_next_bonuslen[0], sizeof (dn->dn_next_bonuslen)); 127 bzero(&dn->dn_next_blksz[0], sizeof (dn->dn_next_blksz)); 128 129 for (i = 0; i < TXG_SIZE; i++) { 130 list_link_init(&dn->dn_dirty_link[i]); 131 dn->dn_free_ranges[i] = NULL; 132 list_create(&dn->dn_dirty_records[i], 133 sizeof (dbuf_dirty_record_t), 134 offsetof(dbuf_dirty_record_t, dr_dirty_node)); 135 } 136 137 dn->dn_allocated_txg = 0; 138 dn->dn_free_txg = 0; 139 dn->dn_assigned_txg = 0; 140 dn->dn_dirtyctx = 0; 141 dn->dn_dirtyctx_firstset = NULL; 142 dn->dn_bonus = NULL; 143 dn->dn_have_spill = B_FALSE; 144 dn->dn_zio = NULL; 145 dn->dn_oldused = 0; 146 dn->dn_oldflags = 0; 147 dn->dn_olduid = 0; 148 dn->dn_oldgid = 0; 149 dn->dn_newuid = 0; 150 dn->dn_newgid = 0; 151 dn->dn_id_flags = 0; 152 153 dn->dn_dbufs_count = 0; 154 dn->dn_unlisted_l0_blkid = 0; 155 avl_create(&dn->dn_dbufs, dbuf_compare, sizeof (dmu_buf_impl_t), 156 offsetof(dmu_buf_impl_t, db_link)); 157 158 dn->dn_moved = 0; 159 return (0); 160 } 161 162 /* ARGSUSED */ 163 static void 164 dnode_dest(void *arg, void *unused) 165 { 166 int i; 167 dnode_t *dn = arg; 168 169 rw_destroy(&dn->dn_struct_rwlock); 170 mutex_destroy(&dn->dn_mtx); 171 mutex_destroy(&dn->dn_dbufs_mtx); 172 cv_destroy(&dn->dn_notxholds); 173 refcount_destroy(&dn->dn_holds); 174 refcount_destroy(&dn->dn_tx_holds); 175 ASSERT(!list_link_active(&dn->dn_link)); 176 177 for (i = 0; i < TXG_SIZE; i++) { 178 ASSERT(!list_link_active(&dn->dn_dirty_link[i])); 179 ASSERT3P(dn->dn_free_ranges[i], ==, NULL); 180 list_destroy(&dn->dn_dirty_records[i]); 181 ASSERT0(dn->dn_next_nblkptr[i]); 182 ASSERT0(dn->dn_next_nlevels[i]); 183 ASSERT0(dn->dn_next_indblkshift[i]); 184 ASSERT0(dn->dn_next_bonustype[i]); 185 ASSERT0(dn->dn_rm_spillblk[i]); 186 ASSERT0(dn->dn_next_bonuslen[i]); 187 ASSERT0(dn->dn_next_blksz[i]); 188 } 189 190 ASSERT0(dn->dn_allocated_txg); 191 ASSERT0(dn->dn_free_txg); 192 ASSERT0(dn->dn_assigned_txg); 193 ASSERT0(dn->dn_dirtyctx); 194 ASSERT3P(dn->dn_dirtyctx_firstset, ==, NULL); 195 ASSERT3P(dn->dn_bonus, ==, NULL); 196 ASSERT(!dn->dn_have_spill); 197 ASSERT3P(dn->dn_zio, ==, NULL); 198 ASSERT0(dn->dn_oldused); 199 ASSERT0(dn->dn_oldflags); 200 ASSERT0(dn->dn_olduid); 201 ASSERT0(dn->dn_oldgid); 202 ASSERT0(dn->dn_newuid); 203 ASSERT0(dn->dn_newgid); 204 ASSERT0(dn->dn_id_flags); 205 206 ASSERT0(dn->dn_dbufs_count); 207 ASSERT0(dn->dn_unlisted_l0_blkid); 208 avl_destroy(&dn->dn_dbufs); 209 } 210 211 void 212 dnode_init(void) 213 { 214 ASSERT(dnode_cache == NULL); 215 dnode_cache = kmem_cache_create("dnode_t", 216 sizeof (dnode_t), 217 0, dnode_cons, dnode_dest, NULL, NULL, NULL, 0); 218 kmem_cache_set_move(dnode_cache, dnode_move); 219 } 220 221 void 222 dnode_fini(void) 223 { 224 kmem_cache_destroy(dnode_cache); 225 dnode_cache = NULL; 226 } 227 228 229 #ifdef ZFS_DEBUG 230 void 231 dnode_verify(dnode_t *dn) 232 { 233 int drop_struct_lock = FALSE; 234 235 ASSERT(dn->dn_phys); 236 ASSERT(dn->dn_objset); 237 ASSERT(dn->dn_handle->dnh_dnode == dn); 238 239 ASSERT(DMU_OT_IS_VALID(dn->dn_phys->dn_type)); 240 241 if (!(zfs_flags & ZFS_DEBUG_DNODE_VERIFY)) 242 return; 243 244 if (!RW_WRITE_HELD(&dn->dn_struct_rwlock)) { 245 rw_enter(&dn->dn_struct_rwlock, RW_READER); 246 drop_struct_lock = TRUE; 247 } 248 if (dn->dn_phys->dn_type != DMU_OT_NONE || dn->dn_allocated_txg != 0) { 249 int i; 250 ASSERT3U(dn->dn_indblkshift, >=, 0); 251 ASSERT3U(dn->dn_indblkshift, <=, SPA_MAXBLOCKSHIFT); 252 if (dn->dn_datablkshift) { 253 ASSERT3U(dn->dn_datablkshift, >=, SPA_MINBLOCKSHIFT); 254 ASSERT3U(dn->dn_datablkshift, <=, SPA_MAXBLOCKSHIFT); 255 ASSERT3U(1<<dn->dn_datablkshift, ==, dn->dn_datablksz); 256 } 257 ASSERT3U(dn->dn_nlevels, <=, 30); 258 ASSERT(DMU_OT_IS_VALID(dn->dn_type)); 259 ASSERT3U(dn->dn_nblkptr, >=, 1); 260 ASSERT3U(dn->dn_nblkptr, <=, DN_MAX_NBLKPTR); 261 ASSERT3U(dn->dn_bonuslen, <=, DN_MAX_BONUSLEN); 262 ASSERT3U(dn->dn_datablksz, ==, 263 dn->dn_datablkszsec << SPA_MINBLOCKSHIFT); 264 ASSERT3U(ISP2(dn->dn_datablksz), ==, dn->dn_datablkshift != 0); 265 ASSERT3U((dn->dn_nblkptr - 1) * sizeof (blkptr_t) + 266 dn->dn_bonuslen, <=, DN_MAX_BONUSLEN); 267 for (i = 0; i < TXG_SIZE; i++) { 268 ASSERT3U(dn->dn_next_nlevels[i], <=, dn->dn_nlevels); 269 } 270 } 271 if (dn->dn_phys->dn_type != DMU_OT_NONE) 272 ASSERT3U(dn->dn_phys->dn_nlevels, <=, dn->dn_nlevels); 273 ASSERT(DMU_OBJECT_IS_SPECIAL(dn->dn_object) || dn->dn_dbuf != NULL); 274 if (dn->dn_dbuf != NULL) { 275 ASSERT3P(dn->dn_phys, ==, 276 (dnode_phys_t *)dn->dn_dbuf->db.db_data + 277 (dn->dn_object % (dn->dn_dbuf->db.db_size >> DNODE_SHIFT))); 278 } 279 if (drop_struct_lock) 280 rw_exit(&dn->dn_struct_rwlock); 281 } 282 #endif 283 284 void 285 dnode_byteswap(dnode_phys_t *dnp) 286 { 287 uint64_t *buf64 = (void*)&dnp->dn_blkptr; 288 int i; 289 290 if (dnp->dn_type == DMU_OT_NONE) { 291 bzero(dnp, sizeof (dnode_phys_t)); 292 return; 293 } 294 295 dnp->dn_datablkszsec = BSWAP_16(dnp->dn_datablkszsec); 296 dnp->dn_bonuslen = BSWAP_16(dnp->dn_bonuslen); 297 dnp->dn_maxblkid = BSWAP_64(dnp->dn_maxblkid); 298 dnp->dn_used = BSWAP_64(dnp->dn_used); 299 300 /* 301 * dn_nblkptr is only one byte, so it's OK to read it in either 302 * byte order. We can't read dn_bouslen. 303 */ 304 ASSERT(dnp->dn_indblkshift <= SPA_MAXBLOCKSHIFT); 305 ASSERT(dnp->dn_nblkptr <= DN_MAX_NBLKPTR); 306 for (i = 0; i < dnp->dn_nblkptr * sizeof (blkptr_t)/8; i++) 307 buf64[i] = BSWAP_64(buf64[i]); 308 309 /* 310 * OK to check dn_bonuslen for zero, because it won't matter if 311 * we have the wrong byte order. This is necessary because the 312 * dnode dnode is smaller than a regular dnode. 313 */ 314 if (dnp->dn_bonuslen != 0) { 315 /* 316 * Note that the bonus length calculated here may be 317 * longer than the actual bonus buffer. This is because 318 * we always put the bonus buffer after the last block 319 * pointer (instead of packing it against the end of the 320 * dnode buffer). 321 */ 322 int off = (dnp->dn_nblkptr-1) * sizeof (blkptr_t); 323 size_t len = DN_MAX_BONUSLEN - off; 324 ASSERT(DMU_OT_IS_VALID(dnp->dn_bonustype)); 325 dmu_object_byteswap_t byteswap = 326 DMU_OT_BYTESWAP(dnp->dn_bonustype); 327 dmu_ot_byteswap[byteswap].ob_func(dnp->dn_bonus + off, len); 328 } 329 330 /* Swap SPILL block if we have one */ 331 if (dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) 332 byteswap_uint64_array(&dnp->dn_spill, sizeof (blkptr_t)); 333 334 } 335 336 void 337 dnode_buf_byteswap(void *vbuf, size_t size) 338 { 339 dnode_phys_t *buf = vbuf; 340 int i; 341 342 ASSERT3U(sizeof (dnode_phys_t), ==, (1<<DNODE_SHIFT)); 343 ASSERT((size & (sizeof (dnode_phys_t)-1)) == 0); 344 345 size >>= DNODE_SHIFT; 346 for (i = 0; i < size; i++) { 347 dnode_byteswap(buf); 348 buf++; 349 } 350 } 351 352 void 353 dnode_setbonuslen(dnode_t *dn, int newsize, dmu_tx_t *tx) 354 { 355 ASSERT3U(refcount_count(&dn->dn_holds), >=, 1); 356 357 dnode_setdirty(dn, tx); 358 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 359 ASSERT3U(newsize, <=, DN_MAX_BONUSLEN - 360 (dn->dn_nblkptr-1) * sizeof (blkptr_t)); 361 dn->dn_bonuslen = newsize; 362 if (newsize == 0) 363 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = DN_ZERO_BONUSLEN; 364 else 365 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = dn->dn_bonuslen; 366 rw_exit(&dn->dn_struct_rwlock); 367 } 368 369 void 370 dnode_setbonus_type(dnode_t *dn, dmu_object_type_t newtype, dmu_tx_t *tx) 371 { 372 ASSERT3U(refcount_count(&dn->dn_holds), >=, 1); 373 dnode_setdirty(dn, tx); 374 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 375 dn->dn_bonustype = newtype; 376 dn->dn_next_bonustype[tx->tx_txg & TXG_MASK] = dn->dn_bonustype; 377 rw_exit(&dn->dn_struct_rwlock); 378 } 379 380 void 381 dnode_rm_spill(dnode_t *dn, dmu_tx_t *tx) 382 { 383 ASSERT3U(refcount_count(&dn->dn_holds), >=, 1); 384 ASSERT(RW_WRITE_HELD(&dn->dn_struct_rwlock)); 385 dnode_setdirty(dn, tx); 386 dn->dn_rm_spillblk[tx->tx_txg&TXG_MASK] = DN_KILL_SPILLBLK; 387 dn->dn_have_spill = B_FALSE; 388 } 389 390 static void 391 dnode_setdblksz(dnode_t *dn, int size) 392 { 393 ASSERT0(P2PHASE(size, SPA_MINBLOCKSIZE)); 394 ASSERT3U(size, <=, SPA_MAXBLOCKSIZE); 395 ASSERT3U(size, >=, SPA_MINBLOCKSIZE); 396 ASSERT3U(size >> SPA_MINBLOCKSHIFT, <, 397 1<<(sizeof (dn->dn_phys->dn_datablkszsec) * 8)); 398 dn->dn_datablksz = size; 399 dn->dn_datablkszsec = size >> SPA_MINBLOCKSHIFT; 400 dn->dn_datablkshift = ISP2(size) ? highbit64(size - 1) : 0; 401 } 402 403 static dnode_t * 404 dnode_create(objset_t *os, dnode_phys_t *dnp, dmu_buf_impl_t *db, 405 uint64_t object, dnode_handle_t *dnh) 406 { 407 dnode_t *dn; 408 409 dn = kmem_cache_alloc(dnode_cache, KM_SLEEP); 410 ASSERT(!POINTER_IS_VALID(dn->dn_objset)); 411 dn->dn_moved = 0; 412 413 /* 414 * Defer setting dn_objset until the dnode is ready to be a candidate 415 * for the dnode_move() callback. 416 */ 417 dn->dn_object = object; 418 dn->dn_dbuf = db; 419 dn->dn_handle = dnh; 420 dn->dn_phys = dnp; 421 422 if (dnp->dn_datablkszsec) { 423 dnode_setdblksz(dn, dnp->dn_datablkszsec << SPA_MINBLOCKSHIFT); 424 } else { 425 dn->dn_datablksz = 0; 426 dn->dn_datablkszsec = 0; 427 dn->dn_datablkshift = 0; 428 } 429 dn->dn_indblkshift = dnp->dn_indblkshift; 430 dn->dn_nlevels = dnp->dn_nlevels; 431 dn->dn_type = dnp->dn_type; 432 dn->dn_nblkptr = dnp->dn_nblkptr; 433 dn->dn_checksum = dnp->dn_checksum; 434 dn->dn_compress = dnp->dn_compress; 435 dn->dn_bonustype = dnp->dn_bonustype; 436 dn->dn_bonuslen = dnp->dn_bonuslen; 437 dn->dn_maxblkid = dnp->dn_maxblkid; 438 dn->dn_have_spill = ((dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) != 0); 439 dn->dn_id_flags = 0; 440 441 dmu_zfetch_init(&dn->dn_zfetch, dn); 442 443 ASSERT(DMU_OT_IS_VALID(dn->dn_phys->dn_type)); 444 445 mutex_enter(&os->os_lock); 446 if (dnh->dnh_dnode != NULL) { 447 /* Lost the allocation race. */ 448 mutex_exit(&os->os_lock); 449 kmem_cache_free(dnode_cache, dn); 450 return (dnh->dnh_dnode); 451 } 452 453 /* 454 * Exclude special dnodes from os_dnodes so an empty os_dnodes 455 * signifies that the special dnodes have no references from 456 * their children (the entries in os_dnodes). This allows 457 * dnode_destroy() to easily determine if the last child has 458 * been removed and then complete eviction of the objset. 459 */ 460 if (!DMU_OBJECT_IS_SPECIAL(object)) 461 list_insert_head(&os->os_dnodes, dn); 462 membar_producer(); 463 464 /* 465 * Everything else must be valid before assigning dn_objset 466 * makes the dnode eligible for dnode_move(). 467 */ 468 dn->dn_objset = os; 469 470 dnh->dnh_dnode = dn; 471 mutex_exit(&os->os_lock); 472 473 arc_space_consume(sizeof (dnode_t), ARC_SPACE_OTHER); 474 return (dn); 475 } 476 477 /* 478 * Caller must be holding the dnode handle, which is released upon return. 479 */ 480 static void 481 dnode_destroy(dnode_t *dn) 482 { 483 objset_t *os = dn->dn_objset; 484 boolean_t complete_os_eviction = B_FALSE; 485 486 ASSERT((dn->dn_id_flags & DN_ID_NEW_EXIST) == 0); 487 488 mutex_enter(&os->os_lock); 489 POINTER_INVALIDATE(&dn->dn_objset); 490 if (!DMU_OBJECT_IS_SPECIAL(dn->dn_object)) { 491 list_remove(&os->os_dnodes, dn); 492 complete_os_eviction = 493 list_is_empty(&os->os_dnodes) && 494 list_link_active(&os->os_evicting_node); 495 } 496 mutex_exit(&os->os_lock); 497 498 /* the dnode can no longer move, so we can release the handle */ 499 zrl_remove(&dn->dn_handle->dnh_zrlock); 500 501 dn->dn_allocated_txg = 0; 502 dn->dn_free_txg = 0; 503 dn->dn_assigned_txg = 0; 504 505 dn->dn_dirtyctx = 0; 506 if (dn->dn_dirtyctx_firstset != NULL) { 507 kmem_free(dn->dn_dirtyctx_firstset, 1); 508 dn->dn_dirtyctx_firstset = NULL; 509 } 510 if (dn->dn_bonus != NULL) { 511 mutex_enter(&dn->dn_bonus->db_mtx); 512 dbuf_evict(dn->dn_bonus); 513 dn->dn_bonus = NULL; 514 } 515 dn->dn_zio = NULL; 516 517 dn->dn_have_spill = B_FALSE; 518 dn->dn_oldused = 0; 519 dn->dn_oldflags = 0; 520 dn->dn_olduid = 0; 521 dn->dn_oldgid = 0; 522 dn->dn_newuid = 0; 523 dn->dn_newgid = 0; 524 dn->dn_id_flags = 0; 525 dn->dn_unlisted_l0_blkid = 0; 526 527 dmu_zfetch_fini(&dn->dn_zfetch); 528 kmem_cache_free(dnode_cache, dn); 529 arc_space_return(sizeof (dnode_t), ARC_SPACE_OTHER); 530 531 if (complete_os_eviction) 532 dmu_objset_evict_done(os); 533 } 534 535 void 536 dnode_allocate(dnode_t *dn, dmu_object_type_t ot, int blocksize, int ibs, 537 dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx) 538 { 539 int i; 540 541 ASSERT3U(blocksize, <=, 542 spa_maxblocksize(dmu_objset_spa(dn->dn_objset))); 543 if (blocksize == 0) 544 blocksize = 1 << zfs_default_bs; 545 else 546 blocksize = P2ROUNDUP(blocksize, SPA_MINBLOCKSIZE); 547 548 if (ibs == 0) 549 ibs = zfs_default_ibs; 550 551 ibs = MIN(MAX(ibs, DN_MIN_INDBLKSHIFT), DN_MAX_INDBLKSHIFT); 552 553 dprintf("os=%p obj=%llu txg=%llu blocksize=%d ibs=%d\n", dn->dn_objset, 554 dn->dn_object, tx->tx_txg, blocksize, ibs); 555 556 ASSERT(dn->dn_type == DMU_OT_NONE); 557 ASSERT(bcmp(dn->dn_phys, &dnode_phys_zero, sizeof (dnode_phys_t)) == 0); 558 ASSERT(dn->dn_phys->dn_type == DMU_OT_NONE); 559 ASSERT(ot != DMU_OT_NONE); 560 ASSERT(DMU_OT_IS_VALID(ot)); 561 ASSERT((bonustype == DMU_OT_NONE && bonuslen == 0) || 562 (bonustype == DMU_OT_SA && bonuslen == 0) || 563 (bonustype != DMU_OT_NONE && bonuslen != 0)); 564 ASSERT(DMU_OT_IS_VALID(bonustype)); 565 ASSERT3U(bonuslen, <=, DN_MAX_BONUSLEN); 566 ASSERT(dn->dn_type == DMU_OT_NONE); 567 ASSERT0(dn->dn_maxblkid); 568 ASSERT0(dn->dn_allocated_txg); 569 ASSERT0(dn->dn_assigned_txg); 570 ASSERT(refcount_is_zero(&dn->dn_tx_holds)); 571 ASSERT3U(refcount_count(&dn->dn_holds), <=, 1); 572 ASSERT(avl_is_empty(&dn->dn_dbufs)); 573 574 for (i = 0; i < TXG_SIZE; i++) { 575 ASSERT0(dn->dn_next_nblkptr[i]); 576 ASSERT0(dn->dn_next_nlevels[i]); 577 ASSERT0(dn->dn_next_indblkshift[i]); 578 ASSERT0(dn->dn_next_bonuslen[i]); 579 ASSERT0(dn->dn_next_bonustype[i]); 580 ASSERT0(dn->dn_rm_spillblk[i]); 581 ASSERT0(dn->dn_next_blksz[i]); 582 ASSERT(!list_link_active(&dn->dn_dirty_link[i])); 583 ASSERT3P(list_head(&dn->dn_dirty_records[i]), ==, NULL); 584 ASSERT3P(dn->dn_free_ranges[i], ==, NULL); 585 } 586 587 dn->dn_type = ot; 588 dnode_setdblksz(dn, blocksize); 589 dn->dn_indblkshift = ibs; 590 dn->dn_nlevels = 1; 591 if (bonustype == DMU_OT_SA) /* Maximize bonus space for SA */ 592 dn->dn_nblkptr = 1; 593 else 594 dn->dn_nblkptr = 1 + 595 ((DN_MAX_BONUSLEN - bonuslen) >> SPA_BLKPTRSHIFT); 596 dn->dn_bonustype = bonustype; 597 dn->dn_bonuslen = bonuslen; 598 dn->dn_checksum = ZIO_CHECKSUM_INHERIT; 599 dn->dn_compress = ZIO_COMPRESS_INHERIT; 600 dn->dn_dirtyctx = 0; 601 602 dn->dn_free_txg = 0; 603 if (dn->dn_dirtyctx_firstset) { 604 kmem_free(dn->dn_dirtyctx_firstset, 1); 605 dn->dn_dirtyctx_firstset = NULL; 606 } 607 608 dn->dn_allocated_txg = tx->tx_txg; 609 dn->dn_id_flags = 0; 610 611 dnode_setdirty(dn, tx); 612 dn->dn_next_indblkshift[tx->tx_txg & TXG_MASK] = ibs; 613 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = dn->dn_bonuslen; 614 dn->dn_next_bonustype[tx->tx_txg & TXG_MASK] = dn->dn_bonustype; 615 dn->dn_next_blksz[tx->tx_txg & TXG_MASK] = dn->dn_datablksz; 616 } 617 618 void 619 dnode_reallocate(dnode_t *dn, dmu_object_type_t ot, int blocksize, 620 dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx) 621 { 622 int nblkptr; 623 624 ASSERT3U(blocksize, >=, SPA_MINBLOCKSIZE); 625 ASSERT3U(blocksize, <=, 626 spa_maxblocksize(dmu_objset_spa(dn->dn_objset))); 627 ASSERT0(blocksize % SPA_MINBLOCKSIZE); 628 ASSERT(dn->dn_object != DMU_META_DNODE_OBJECT || dmu_tx_private_ok(tx)); 629 ASSERT(tx->tx_txg != 0); 630 ASSERT((bonustype == DMU_OT_NONE && bonuslen == 0) || 631 (bonustype != DMU_OT_NONE && bonuslen != 0) || 632 (bonustype == DMU_OT_SA && bonuslen == 0)); 633 ASSERT(DMU_OT_IS_VALID(bonustype)); 634 ASSERT3U(bonuslen, <=, DN_MAX_BONUSLEN); 635 636 /* clean up any unreferenced dbufs */ 637 dnode_evict_dbufs(dn); 638 639 dn->dn_id_flags = 0; 640 641 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 642 dnode_setdirty(dn, tx); 643 if (dn->dn_datablksz != blocksize) { 644 /* change blocksize */ 645 ASSERT(dn->dn_maxblkid == 0 && 646 (BP_IS_HOLE(&dn->dn_phys->dn_blkptr[0]) || 647 dnode_block_freed(dn, 0))); 648 dnode_setdblksz(dn, blocksize); 649 dn->dn_next_blksz[tx->tx_txg&TXG_MASK] = blocksize; 650 } 651 if (dn->dn_bonuslen != bonuslen) 652 dn->dn_next_bonuslen[tx->tx_txg&TXG_MASK] = bonuslen; 653 654 if (bonustype == DMU_OT_SA) /* Maximize bonus space for SA */ 655 nblkptr = 1; 656 else 657 nblkptr = 1 + ((DN_MAX_BONUSLEN - bonuslen) >> SPA_BLKPTRSHIFT); 658 if (dn->dn_bonustype != bonustype) 659 dn->dn_next_bonustype[tx->tx_txg&TXG_MASK] = bonustype; 660 if (dn->dn_nblkptr != nblkptr) 661 dn->dn_next_nblkptr[tx->tx_txg&TXG_MASK] = nblkptr; 662 if (dn->dn_phys->dn_flags & DNODE_FLAG_SPILL_BLKPTR) { 663 dbuf_rm_spill(dn, tx); 664 dnode_rm_spill(dn, tx); 665 } 666 rw_exit(&dn->dn_struct_rwlock); 667 668 /* change type */ 669 dn->dn_type = ot; 670 671 /* change bonus size and type */ 672 mutex_enter(&dn->dn_mtx); 673 dn->dn_bonustype = bonustype; 674 dn->dn_bonuslen = bonuslen; 675 dn->dn_nblkptr = nblkptr; 676 dn->dn_checksum = ZIO_CHECKSUM_INHERIT; 677 dn->dn_compress = ZIO_COMPRESS_INHERIT; 678 ASSERT3U(dn->dn_nblkptr, <=, DN_MAX_NBLKPTR); 679 680 /* fix up the bonus db_size */ 681 if (dn->dn_bonus) { 682 dn->dn_bonus->db.db_size = 683 DN_MAX_BONUSLEN - (dn->dn_nblkptr-1) * sizeof (blkptr_t); 684 ASSERT(dn->dn_bonuslen <= dn->dn_bonus->db.db_size); 685 } 686 687 dn->dn_allocated_txg = tx->tx_txg; 688 mutex_exit(&dn->dn_mtx); 689 } 690 691 #ifdef DNODE_STATS 692 static struct { 693 uint64_t dms_dnode_invalid; 694 uint64_t dms_dnode_recheck1; 695 uint64_t dms_dnode_recheck2; 696 uint64_t dms_dnode_special; 697 uint64_t dms_dnode_handle; 698 uint64_t dms_dnode_rwlock; 699 uint64_t dms_dnode_active; 700 } dnode_move_stats; 701 #endif /* DNODE_STATS */ 702 703 static void 704 dnode_move_impl(dnode_t *odn, dnode_t *ndn) 705 { 706 int i; 707 708 ASSERT(!RW_LOCK_HELD(&odn->dn_struct_rwlock)); 709 ASSERT(MUTEX_NOT_HELD(&odn->dn_mtx)); 710 ASSERT(MUTEX_NOT_HELD(&odn->dn_dbufs_mtx)); 711 ASSERT(!RW_LOCK_HELD(&odn->dn_zfetch.zf_rwlock)); 712 713 /* Copy fields. */ 714 ndn->dn_objset = odn->dn_objset; 715 ndn->dn_object = odn->dn_object; 716 ndn->dn_dbuf = odn->dn_dbuf; 717 ndn->dn_handle = odn->dn_handle; 718 ndn->dn_phys = odn->dn_phys; 719 ndn->dn_type = odn->dn_type; 720 ndn->dn_bonuslen = odn->dn_bonuslen; 721 ndn->dn_bonustype = odn->dn_bonustype; 722 ndn->dn_nblkptr = odn->dn_nblkptr; 723 ndn->dn_checksum = odn->dn_checksum; 724 ndn->dn_compress = odn->dn_compress; 725 ndn->dn_nlevels = odn->dn_nlevels; 726 ndn->dn_indblkshift = odn->dn_indblkshift; 727 ndn->dn_datablkshift = odn->dn_datablkshift; 728 ndn->dn_datablkszsec = odn->dn_datablkszsec; 729 ndn->dn_datablksz = odn->dn_datablksz; 730 ndn->dn_maxblkid = odn->dn_maxblkid; 731 bcopy(&odn->dn_next_nblkptr[0], &ndn->dn_next_nblkptr[0], 732 sizeof (odn->dn_next_nblkptr)); 733 bcopy(&odn->dn_next_nlevels[0], &ndn->dn_next_nlevels[0], 734 sizeof (odn->dn_next_nlevels)); 735 bcopy(&odn->dn_next_indblkshift[0], &ndn->dn_next_indblkshift[0], 736 sizeof (odn->dn_next_indblkshift)); 737 bcopy(&odn->dn_next_bonustype[0], &ndn->dn_next_bonustype[0], 738 sizeof (odn->dn_next_bonustype)); 739 bcopy(&odn->dn_rm_spillblk[0], &ndn->dn_rm_spillblk[0], 740 sizeof (odn->dn_rm_spillblk)); 741 bcopy(&odn->dn_next_bonuslen[0], &ndn->dn_next_bonuslen[0], 742 sizeof (odn->dn_next_bonuslen)); 743 bcopy(&odn->dn_next_blksz[0], &ndn->dn_next_blksz[0], 744 sizeof (odn->dn_next_blksz)); 745 for (i = 0; i < TXG_SIZE; i++) { 746 list_move_tail(&ndn->dn_dirty_records[i], 747 &odn->dn_dirty_records[i]); 748 } 749 bcopy(&odn->dn_free_ranges[0], &ndn->dn_free_ranges[0], 750 sizeof (odn->dn_free_ranges)); 751 ndn->dn_allocated_txg = odn->dn_allocated_txg; 752 ndn->dn_free_txg = odn->dn_free_txg; 753 ndn->dn_assigned_txg = odn->dn_assigned_txg; 754 ndn->dn_dirtyctx = odn->dn_dirtyctx; 755 ndn->dn_dirtyctx_firstset = odn->dn_dirtyctx_firstset; 756 ASSERT(refcount_count(&odn->dn_tx_holds) == 0); 757 refcount_transfer(&ndn->dn_holds, &odn->dn_holds); 758 ASSERT(avl_is_empty(&ndn->dn_dbufs)); 759 avl_swap(&ndn->dn_dbufs, &odn->dn_dbufs); 760 ndn->dn_dbufs_count = odn->dn_dbufs_count; 761 ndn->dn_unlisted_l0_blkid = odn->dn_unlisted_l0_blkid; 762 ndn->dn_bonus = odn->dn_bonus; 763 ndn->dn_have_spill = odn->dn_have_spill; 764 ndn->dn_zio = odn->dn_zio; 765 ndn->dn_oldused = odn->dn_oldused; 766 ndn->dn_oldflags = odn->dn_oldflags; 767 ndn->dn_olduid = odn->dn_olduid; 768 ndn->dn_oldgid = odn->dn_oldgid; 769 ndn->dn_newuid = odn->dn_newuid; 770 ndn->dn_newgid = odn->dn_newgid; 771 ndn->dn_id_flags = odn->dn_id_flags; 772 dmu_zfetch_init(&ndn->dn_zfetch, NULL); 773 list_move_tail(&ndn->dn_zfetch.zf_stream, &odn->dn_zfetch.zf_stream); 774 ndn->dn_zfetch.zf_dnode = odn->dn_zfetch.zf_dnode; 775 776 /* 777 * Update back pointers. Updating the handle fixes the back pointer of 778 * every descendant dbuf as well as the bonus dbuf. 779 */ 780 ASSERT(ndn->dn_handle->dnh_dnode == odn); 781 ndn->dn_handle->dnh_dnode = ndn; 782 if (ndn->dn_zfetch.zf_dnode == odn) { 783 ndn->dn_zfetch.zf_dnode = ndn; 784 } 785 786 /* 787 * Invalidate the original dnode by clearing all of its back pointers. 788 */ 789 odn->dn_dbuf = NULL; 790 odn->dn_handle = NULL; 791 avl_create(&odn->dn_dbufs, dbuf_compare, sizeof (dmu_buf_impl_t), 792 offsetof(dmu_buf_impl_t, db_link)); 793 odn->dn_dbufs_count = 0; 794 odn->dn_unlisted_l0_blkid = 0; 795 odn->dn_bonus = NULL; 796 odn->dn_zfetch.zf_dnode = NULL; 797 798 /* 799 * Set the low bit of the objset pointer to ensure that dnode_move() 800 * recognizes the dnode as invalid in any subsequent callback. 801 */ 802 POINTER_INVALIDATE(&odn->dn_objset); 803 804 /* 805 * Satisfy the destructor. 806 */ 807 for (i = 0; i < TXG_SIZE; i++) { 808 list_create(&odn->dn_dirty_records[i], 809 sizeof (dbuf_dirty_record_t), 810 offsetof(dbuf_dirty_record_t, dr_dirty_node)); 811 odn->dn_free_ranges[i] = NULL; 812 odn->dn_next_nlevels[i] = 0; 813 odn->dn_next_indblkshift[i] = 0; 814 odn->dn_next_bonustype[i] = 0; 815 odn->dn_rm_spillblk[i] = 0; 816 odn->dn_next_bonuslen[i] = 0; 817 odn->dn_next_blksz[i] = 0; 818 } 819 odn->dn_allocated_txg = 0; 820 odn->dn_free_txg = 0; 821 odn->dn_assigned_txg = 0; 822 odn->dn_dirtyctx = 0; 823 odn->dn_dirtyctx_firstset = NULL; 824 odn->dn_have_spill = B_FALSE; 825 odn->dn_zio = NULL; 826 odn->dn_oldused = 0; 827 odn->dn_oldflags = 0; 828 odn->dn_olduid = 0; 829 odn->dn_oldgid = 0; 830 odn->dn_newuid = 0; 831 odn->dn_newgid = 0; 832 odn->dn_id_flags = 0; 833 834 /* 835 * Mark the dnode. 836 */ 837 ndn->dn_moved = 1; 838 odn->dn_moved = (uint8_t)-1; 839 } 840 841 #ifdef _KERNEL 842 /*ARGSUSED*/ 843 static kmem_cbrc_t 844 dnode_move(void *buf, void *newbuf, size_t size, void *arg) 845 { 846 dnode_t *odn = buf, *ndn = newbuf; 847 objset_t *os; 848 int64_t refcount; 849 uint32_t dbufs; 850 851 /* 852 * The dnode is on the objset's list of known dnodes if the objset 853 * pointer is valid. We set the low bit of the objset pointer when 854 * freeing the dnode to invalidate it, and the memory patterns written 855 * by kmem (baddcafe and deadbeef) set at least one of the two low bits. 856 * A newly created dnode sets the objset pointer last of all to indicate 857 * that the dnode is known and in a valid state to be moved by this 858 * function. 859 */ 860 os = odn->dn_objset; 861 if (!POINTER_IS_VALID(os)) { 862 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_invalid); 863 return (KMEM_CBRC_DONT_KNOW); 864 } 865 866 /* 867 * Ensure that the objset does not go away during the move. 868 */ 869 rw_enter(&os_lock, RW_WRITER); 870 if (os != odn->dn_objset) { 871 rw_exit(&os_lock); 872 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_recheck1); 873 return (KMEM_CBRC_DONT_KNOW); 874 } 875 876 /* 877 * If the dnode is still valid, then so is the objset. We know that no 878 * valid objset can be freed while we hold os_lock, so we can safely 879 * ensure that the objset remains in use. 880 */ 881 mutex_enter(&os->os_lock); 882 883 /* 884 * Recheck the objset pointer in case the dnode was removed just before 885 * acquiring the lock. 886 */ 887 if (os != odn->dn_objset) { 888 mutex_exit(&os->os_lock); 889 rw_exit(&os_lock); 890 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_recheck2); 891 return (KMEM_CBRC_DONT_KNOW); 892 } 893 894 /* 895 * At this point we know that as long as we hold os->os_lock, the dnode 896 * cannot be freed and fields within the dnode can be safely accessed. 897 * The objset listing this dnode cannot go away as long as this dnode is 898 * on its list. 899 */ 900 rw_exit(&os_lock); 901 if (DMU_OBJECT_IS_SPECIAL(odn->dn_object)) { 902 mutex_exit(&os->os_lock); 903 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_special); 904 return (KMEM_CBRC_NO); 905 } 906 ASSERT(odn->dn_dbuf != NULL); /* only "special" dnodes have no parent */ 907 908 /* 909 * Lock the dnode handle to prevent the dnode from obtaining any new 910 * holds. This also prevents the descendant dbufs and the bonus dbuf 911 * from accessing the dnode, so that we can discount their holds. The 912 * handle is safe to access because we know that while the dnode cannot 913 * go away, neither can its handle. Once we hold dnh_zrlock, we can 914 * safely move any dnode referenced only by dbufs. 915 */ 916 if (!zrl_tryenter(&odn->dn_handle->dnh_zrlock)) { 917 mutex_exit(&os->os_lock); 918 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_handle); 919 return (KMEM_CBRC_LATER); 920 } 921 922 /* 923 * Ensure a consistent view of the dnode's holds and the dnode's dbufs. 924 * We need to guarantee that there is a hold for every dbuf in order to 925 * determine whether the dnode is actively referenced. Falsely matching 926 * a dbuf to an active hold would lead to an unsafe move. It's possible 927 * that a thread already having an active dnode hold is about to add a 928 * dbuf, and we can't compare hold and dbuf counts while the add is in 929 * progress. 930 */ 931 if (!rw_tryenter(&odn->dn_struct_rwlock, RW_WRITER)) { 932 zrl_exit(&odn->dn_handle->dnh_zrlock); 933 mutex_exit(&os->os_lock); 934 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_rwlock); 935 return (KMEM_CBRC_LATER); 936 } 937 938 /* 939 * A dbuf may be removed (evicted) without an active dnode hold. In that 940 * case, the dbuf count is decremented under the handle lock before the 941 * dbuf's hold is released. This order ensures that if we count the hold 942 * after the dbuf is removed but before its hold is released, we will 943 * treat the unmatched hold as active and exit safely. If we count the 944 * hold before the dbuf is removed, the hold is discounted, and the 945 * removal is blocked until the move completes. 946 */ 947 refcount = refcount_count(&odn->dn_holds); 948 ASSERT(refcount >= 0); 949 dbufs = odn->dn_dbufs_count; 950 951 /* We can't have more dbufs than dnode holds. */ 952 ASSERT3U(dbufs, <=, refcount); 953 DTRACE_PROBE3(dnode__move, dnode_t *, odn, int64_t, refcount, 954 uint32_t, dbufs); 955 956 if (refcount > dbufs) { 957 rw_exit(&odn->dn_struct_rwlock); 958 zrl_exit(&odn->dn_handle->dnh_zrlock); 959 mutex_exit(&os->os_lock); 960 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_active); 961 return (KMEM_CBRC_LATER); 962 } 963 964 rw_exit(&odn->dn_struct_rwlock); 965 966 /* 967 * At this point we know that anyone with a hold on the dnode is not 968 * actively referencing it. The dnode is known and in a valid state to 969 * move. We're holding the locks needed to execute the critical section. 970 */ 971 dnode_move_impl(odn, ndn); 972 973 list_link_replace(&odn->dn_link, &ndn->dn_link); 974 /* If the dnode was safe to move, the refcount cannot have changed. */ 975 ASSERT(refcount == refcount_count(&ndn->dn_holds)); 976 ASSERT(dbufs == ndn->dn_dbufs_count); 977 zrl_exit(&ndn->dn_handle->dnh_zrlock); /* handle has moved */ 978 mutex_exit(&os->os_lock); 979 980 return (KMEM_CBRC_YES); 981 } 982 #endif /* _KERNEL */ 983 984 void 985 dnode_special_close(dnode_handle_t *dnh) 986 { 987 dnode_t *dn = dnh->dnh_dnode; 988 989 /* 990 * Wait for final references to the dnode to clear. This can 991 * only happen if the arc is asyncronously evicting state that 992 * has a hold on this dnode while we are trying to evict this 993 * dnode. 994 */ 995 while (refcount_count(&dn->dn_holds) > 0) 996 delay(1); 997 ASSERT(dn->dn_dbuf == NULL || 998 dmu_buf_get_user(&dn->dn_dbuf->db) == NULL); 999 zrl_add(&dnh->dnh_zrlock); 1000 dnode_destroy(dn); /* implicit zrl_remove() */ 1001 zrl_destroy(&dnh->dnh_zrlock); 1002 dnh->dnh_dnode = NULL; 1003 } 1004 1005 void 1006 dnode_special_open(objset_t *os, dnode_phys_t *dnp, uint64_t object, 1007 dnode_handle_t *dnh) 1008 { 1009 dnode_t *dn; 1010 1011 dn = dnode_create(os, dnp, NULL, object, dnh); 1012 zrl_init(&dnh->dnh_zrlock); 1013 DNODE_VERIFY(dn); 1014 } 1015 1016 static void 1017 dnode_buf_evict_async(void *dbu) 1018 { 1019 dnode_children_t *children_dnodes = dbu; 1020 int i; 1021 1022 for (i = 0; i < children_dnodes->dnc_count; i++) { 1023 dnode_handle_t *dnh = &children_dnodes->dnc_children[i]; 1024 dnode_t *dn; 1025 1026 /* 1027 * The dnode handle lock guards against the dnode moving to 1028 * another valid address, so there is no need here to guard 1029 * against changes to or from NULL. 1030 */ 1031 if (dnh->dnh_dnode == NULL) { 1032 zrl_destroy(&dnh->dnh_zrlock); 1033 continue; 1034 } 1035 1036 zrl_add(&dnh->dnh_zrlock); 1037 dn = dnh->dnh_dnode; 1038 /* 1039 * If there are holds on this dnode, then there should 1040 * be holds on the dnode's containing dbuf as well; thus 1041 * it wouldn't be eligible for eviction and this function 1042 * would not have been called. 1043 */ 1044 ASSERT(refcount_is_zero(&dn->dn_holds)); 1045 ASSERT(refcount_is_zero(&dn->dn_tx_holds)); 1046 1047 dnode_destroy(dn); /* implicit zrl_remove() */ 1048 zrl_destroy(&dnh->dnh_zrlock); 1049 dnh->dnh_dnode = NULL; 1050 } 1051 kmem_free(children_dnodes, sizeof (dnode_children_t) + 1052 children_dnodes->dnc_count * sizeof (dnode_handle_t)); 1053 } 1054 1055 /* 1056 * errors: 1057 * EINVAL - invalid object number. 1058 * EIO - i/o error. 1059 * succeeds even for free dnodes. 1060 */ 1061 int 1062 dnode_hold_impl(objset_t *os, uint64_t object, int flag, 1063 void *tag, dnode_t **dnp) 1064 { 1065 int epb, idx, err; 1066 int drop_struct_lock = FALSE; 1067 int type; 1068 uint64_t blk; 1069 dnode_t *mdn, *dn; 1070 dmu_buf_impl_t *db; 1071 dnode_children_t *children_dnodes; 1072 dnode_handle_t *dnh; 1073 1074 /* 1075 * If you are holding the spa config lock as writer, you shouldn't 1076 * be asking the DMU to do *anything* unless it's the root pool 1077 * which may require us to read from the root filesystem while 1078 * holding some (not all) of the locks as writer. 1079 */ 1080 ASSERT(spa_config_held(os->os_spa, SCL_ALL, RW_WRITER) == 0 || 1081 (spa_is_root(os->os_spa) && 1082 spa_config_held(os->os_spa, SCL_STATE, RW_WRITER))); 1083 1084 if (object == DMU_USERUSED_OBJECT || object == DMU_GROUPUSED_OBJECT) { 1085 dn = (object == DMU_USERUSED_OBJECT) ? 1086 DMU_USERUSED_DNODE(os) : DMU_GROUPUSED_DNODE(os); 1087 if (dn == NULL) 1088 return (SET_ERROR(ENOENT)); 1089 type = dn->dn_type; 1090 if ((flag & DNODE_MUST_BE_ALLOCATED) && type == DMU_OT_NONE) 1091 return (SET_ERROR(ENOENT)); 1092 if ((flag & DNODE_MUST_BE_FREE) && type != DMU_OT_NONE) 1093 return (SET_ERROR(EEXIST)); 1094 DNODE_VERIFY(dn); 1095 (void) refcount_add(&dn->dn_holds, tag); 1096 *dnp = dn; 1097 return (0); 1098 } 1099 1100 if (object == 0 || object >= DN_MAX_OBJECT) 1101 return (SET_ERROR(EINVAL)); 1102 1103 mdn = DMU_META_DNODE(os); 1104 ASSERT(mdn->dn_object == DMU_META_DNODE_OBJECT); 1105 1106 DNODE_VERIFY(mdn); 1107 1108 if (!RW_WRITE_HELD(&mdn->dn_struct_rwlock)) { 1109 rw_enter(&mdn->dn_struct_rwlock, RW_READER); 1110 drop_struct_lock = TRUE; 1111 } 1112 1113 blk = dbuf_whichblock(mdn, 0, object * sizeof (dnode_phys_t)); 1114 1115 db = dbuf_hold(mdn, blk, FTAG); 1116 if (drop_struct_lock) 1117 rw_exit(&mdn->dn_struct_rwlock); 1118 if (db == NULL) 1119 return (SET_ERROR(EIO)); 1120 err = dbuf_read(db, NULL, DB_RF_CANFAIL); 1121 if (err) { 1122 dbuf_rele(db, FTAG); 1123 return (err); 1124 } 1125 1126 ASSERT3U(db->db.db_size, >=, 1<<DNODE_SHIFT); 1127 epb = db->db.db_size >> DNODE_SHIFT; 1128 1129 idx = object & (epb-1); 1130 1131 ASSERT(DB_DNODE(db)->dn_type == DMU_OT_DNODE); 1132 children_dnodes = dmu_buf_get_user(&db->db); 1133 if (children_dnodes == NULL) { 1134 int i; 1135 dnode_children_t *winner; 1136 children_dnodes = kmem_zalloc(sizeof (dnode_children_t) + 1137 epb * sizeof (dnode_handle_t), KM_SLEEP); 1138 children_dnodes->dnc_count = epb; 1139 dnh = &children_dnodes->dnc_children[0]; 1140 for (i = 0; i < epb; i++) { 1141 zrl_init(&dnh[i].dnh_zrlock); 1142 } 1143 dmu_buf_init_user(&children_dnodes->dnc_dbu, NULL, 1144 dnode_buf_evict_async, NULL); 1145 winner = dmu_buf_set_user(&db->db, &children_dnodes->dnc_dbu); 1146 if (winner != NULL) { 1147 1148 for (i = 0; i < epb; i++) { 1149 zrl_destroy(&dnh[i].dnh_zrlock); 1150 } 1151 1152 kmem_free(children_dnodes, sizeof (dnode_children_t) + 1153 epb * sizeof (dnode_handle_t)); 1154 children_dnodes = winner; 1155 } 1156 } 1157 ASSERT(children_dnodes->dnc_count == epb); 1158 1159 dnh = &children_dnodes->dnc_children[idx]; 1160 zrl_add(&dnh->dnh_zrlock); 1161 dn = dnh->dnh_dnode; 1162 if (dn == NULL) { 1163 dnode_phys_t *phys = (dnode_phys_t *)db->db.db_data+idx; 1164 1165 dn = dnode_create(os, phys, db, object, dnh); 1166 } 1167 1168 mutex_enter(&dn->dn_mtx); 1169 type = dn->dn_type; 1170 if (dn->dn_free_txg || 1171 ((flag & DNODE_MUST_BE_ALLOCATED) && type == DMU_OT_NONE) || 1172 ((flag & DNODE_MUST_BE_FREE) && 1173 (type != DMU_OT_NONE || !refcount_is_zero(&dn->dn_holds)))) { 1174 mutex_exit(&dn->dn_mtx); 1175 zrl_remove(&dnh->dnh_zrlock); 1176 dbuf_rele(db, FTAG); 1177 return (type == DMU_OT_NONE ? ENOENT : EEXIST); 1178 } 1179 if (refcount_add(&dn->dn_holds, tag) == 1) 1180 dbuf_add_ref(db, dnh); 1181 mutex_exit(&dn->dn_mtx); 1182 1183 /* Now we can rely on the hold to prevent the dnode from moving. */ 1184 zrl_remove(&dnh->dnh_zrlock); 1185 1186 DNODE_VERIFY(dn); 1187 ASSERT3P(dn->dn_dbuf, ==, db); 1188 ASSERT3U(dn->dn_object, ==, object); 1189 dbuf_rele(db, FTAG); 1190 1191 *dnp = dn; 1192 return (0); 1193 } 1194 1195 /* 1196 * Return held dnode if the object is allocated, NULL if not. 1197 */ 1198 int 1199 dnode_hold(objset_t *os, uint64_t object, void *tag, dnode_t **dnp) 1200 { 1201 return (dnode_hold_impl(os, object, DNODE_MUST_BE_ALLOCATED, tag, dnp)); 1202 } 1203 1204 /* 1205 * Can only add a reference if there is already at least one 1206 * reference on the dnode. Returns FALSE if unable to add a 1207 * new reference. 1208 */ 1209 boolean_t 1210 dnode_add_ref(dnode_t *dn, void *tag) 1211 { 1212 mutex_enter(&dn->dn_mtx); 1213 if (refcount_is_zero(&dn->dn_holds)) { 1214 mutex_exit(&dn->dn_mtx); 1215 return (FALSE); 1216 } 1217 VERIFY(1 < refcount_add(&dn->dn_holds, tag)); 1218 mutex_exit(&dn->dn_mtx); 1219 return (TRUE); 1220 } 1221 1222 void 1223 dnode_rele(dnode_t *dn, void *tag) 1224 { 1225 mutex_enter(&dn->dn_mtx); 1226 dnode_rele_and_unlock(dn, tag); 1227 } 1228 1229 void 1230 dnode_rele_and_unlock(dnode_t *dn, void *tag) 1231 { 1232 uint64_t refs; 1233 /* Get while the hold prevents the dnode from moving. */ 1234 dmu_buf_impl_t *db = dn->dn_dbuf; 1235 dnode_handle_t *dnh = dn->dn_handle; 1236 1237 refs = refcount_remove(&dn->dn_holds, tag); 1238 mutex_exit(&dn->dn_mtx); 1239 1240 /* 1241 * It's unsafe to release the last hold on a dnode by dnode_rele() or 1242 * indirectly by dbuf_rele() while relying on the dnode handle to 1243 * prevent the dnode from moving, since releasing the last hold could 1244 * result in the dnode's parent dbuf evicting its dnode handles. For 1245 * that reason anyone calling dnode_rele() or dbuf_rele() without some 1246 * other direct or indirect hold on the dnode must first drop the dnode 1247 * handle. 1248 */ 1249 ASSERT(refs > 0 || dnh->dnh_zrlock.zr_owner != curthread); 1250 1251 /* NOTE: the DNODE_DNODE does not have a dn_dbuf */ 1252 if (refs == 0 && db != NULL) { 1253 /* 1254 * Another thread could add a hold to the dnode handle in 1255 * dnode_hold_impl() while holding the parent dbuf. Since the 1256 * hold on the parent dbuf prevents the handle from being 1257 * destroyed, the hold on the handle is OK. We can't yet assert 1258 * that the handle has zero references, but that will be 1259 * asserted anyway when the handle gets destroyed. 1260 */ 1261 dbuf_rele(db, dnh); 1262 } 1263 } 1264 1265 void 1266 dnode_setdirty(dnode_t *dn, dmu_tx_t *tx) 1267 { 1268 objset_t *os = dn->dn_objset; 1269 uint64_t txg = tx->tx_txg; 1270 1271 if (DMU_OBJECT_IS_SPECIAL(dn->dn_object)) { 1272 dsl_dataset_dirty(os->os_dsl_dataset, tx); 1273 return; 1274 } 1275 1276 DNODE_VERIFY(dn); 1277 1278 #ifdef ZFS_DEBUG 1279 mutex_enter(&dn->dn_mtx); 1280 ASSERT(dn->dn_phys->dn_type || dn->dn_allocated_txg); 1281 ASSERT(dn->dn_free_txg == 0 || dn->dn_free_txg >= txg); 1282 mutex_exit(&dn->dn_mtx); 1283 #endif 1284 1285 /* 1286 * Determine old uid/gid when necessary 1287 */ 1288 dmu_objset_userquota_get_ids(dn, B_TRUE, tx); 1289 1290 mutex_enter(&os->os_lock); 1291 1292 /* 1293 * If we are already marked dirty, we're done. 1294 */ 1295 if (list_link_active(&dn->dn_dirty_link[txg & TXG_MASK])) { 1296 mutex_exit(&os->os_lock); 1297 return; 1298 } 1299 1300 ASSERT(!refcount_is_zero(&dn->dn_holds) || 1301 !avl_is_empty(&dn->dn_dbufs)); 1302 ASSERT(dn->dn_datablksz != 0); 1303 ASSERT0(dn->dn_next_bonuslen[txg&TXG_MASK]); 1304 ASSERT0(dn->dn_next_blksz[txg&TXG_MASK]); 1305 ASSERT0(dn->dn_next_bonustype[txg&TXG_MASK]); 1306 1307 dprintf_ds(os->os_dsl_dataset, "obj=%llu txg=%llu\n", 1308 dn->dn_object, txg); 1309 1310 if (dn->dn_free_txg > 0 && dn->dn_free_txg <= txg) { 1311 list_insert_tail(&os->os_free_dnodes[txg&TXG_MASK], dn); 1312 } else { 1313 list_insert_tail(&os->os_dirty_dnodes[txg&TXG_MASK], dn); 1314 } 1315 1316 mutex_exit(&os->os_lock); 1317 1318 /* 1319 * The dnode maintains a hold on its containing dbuf as 1320 * long as there are holds on it. Each instantiated child 1321 * dbuf maintains a hold on the dnode. When the last child 1322 * drops its hold, the dnode will drop its hold on the 1323 * containing dbuf. We add a "dirty hold" here so that the 1324 * dnode will hang around after we finish processing its 1325 * children. 1326 */ 1327 VERIFY(dnode_add_ref(dn, (void *)(uintptr_t)tx->tx_txg)); 1328 1329 (void) dbuf_dirty(dn->dn_dbuf, tx); 1330 1331 dsl_dataset_dirty(os->os_dsl_dataset, tx); 1332 } 1333 1334 void 1335 dnode_free(dnode_t *dn, dmu_tx_t *tx) 1336 { 1337 int txgoff = tx->tx_txg & TXG_MASK; 1338 1339 dprintf("dn=%p txg=%llu\n", dn, tx->tx_txg); 1340 1341 /* we should be the only holder... hopefully */ 1342 /* ASSERT3U(refcount_count(&dn->dn_holds), ==, 1); */ 1343 1344 mutex_enter(&dn->dn_mtx); 1345 if (dn->dn_type == DMU_OT_NONE || dn->dn_free_txg) { 1346 mutex_exit(&dn->dn_mtx); 1347 return; 1348 } 1349 dn->dn_free_txg = tx->tx_txg; 1350 mutex_exit(&dn->dn_mtx); 1351 1352 /* 1353 * If the dnode is already dirty, it needs to be moved from 1354 * the dirty list to the free list. 1355 */ 1356 mutex_enter(&dn->dn_objset->os_lock); 1357 if (list_link_active(&dn->dn_dirty_link[txgoff])) { 1358 list_remove(&dn->dn_objset->os_dirty_dnodes[txgoff], dn); 1359 list_insert_tail(&dn->dn_objset->os_free_dnodes[txgoff], dn); 1360 mutex_exit(&dn->dn_objset->os_lock); 1361 } else { 1362 mutex_exit(&dn->dn_objset->os_lock); 1363 dnode_setdirty(dn, tx); 1364 } 1365 } 1366 1367 /* 1368 * Try to change the block size for the indicated dnode. This can only 1369 * succeed if there are no blocks allocated or dirty beyond first block 1370 */ 1371 int 1372 dnode_set_blksz(dnode_t *dn, uint64_t size, int ibs, dmu_tx_t *tx) 1373 { 1374 dmu_buf_impl_t *db; 1375 int err; 1376 1377 ASSERT3U(size, <=, spa_maxblocksize(dmu_objset_spa(dn->dn_objset))); 1378 if (size == 0) 1379 size = SPA_MINBLOCKSIZE; 1380 else 1381 size = P2ROUNDUP(size, SPA_MINBLOCKSIZE); 1382 1383 if (ibs == dn->dn_indblkshift) 1384 ibs = 0; 1385 1386 if (size >> SPA_MINBLOCKSHIFT == dn->dn_datablkszsec && ibs == 0) 1387 return (0); 1388 1389 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 1390 1391 /* Check for any allocated blocks beyond the first */ 1392 if (dn->dn_maxblkid != 0) 1393 goto fail; 1394 1395 mutex_enter(&dn->dn_dbufs_mtx); 1396 for (db = avl_first(&dn->dn_dbufs); db != NULL; 1397 db = AVL_NEXT(&dn->dn_dbufs, db)) { 1398 if (db->db_blkid != 0 && db->db_blkid != DMU_BONUS_BLKID && 1399 db->db_blkid != DMU_SPILL_BLKID) { 1400 mutex_exit(&dn->dn_dbufs_mtx); 1401 goto fail; 1402 } 1403 } 1404 mutex_exit(&dn->dn_dbufs_mtx); 1405 1406 if (ibs && dn->dn_nlevels != 1) 1407 goto fail; 1408 1409 /* resize the old block */ 1410 err = dbuf_hold_impl(dn, 0, 0, TRUE, FALSE, FTAG, &db); 1411 if (err == 0) 1412 dbuf_new_size(db, size, tx); 1413 else if (err != ENOENT) 1414 goto fail; 1415 1416 dnode_setdblksz(dn, size); 1417 dnode_setdirty(dn, tx); 1418 dn->dn_next_blksz[tx->tx_txg&TXG_MASK] = size; 1419 if (ibs) { 1420 dn->dn_indblkshift = ibs; 1421 dn->dn_next_indblkshift[tx->tx_txg&TXG_MASK] = ibs; 1422 } 1423 /* rele after we have fixed the blocksize in the dnode */ 1424 if (db) 1425 dbuf_rele(db, FTAG); 1426 1427 rw_exit(&dn->dn_struct_rwlock); 1428 return (0); 1429 1430 fail: 1431 rw_exit(&dn->dn_struct_rwlock); 1432 return (SET_ERROR(ENOTSUP)); 1433 } 1434 1435 /* read-holding callers must not rely on the lock being continuously held */ 1436 void 1437 dnode_new_blkid(dnode_t *dn, uint64_t blkid, dmu_tx_t *tx, boolean_t have_read) 1438 { 1439 uint64_t txgoff = tx->tx_txg & TXG_MASK; 1440 int epbs, new_nlevels; 1441 uint64_t sz; 1442 1443 ASSERT(blkid != DMU_BONUS_BLKID); 1444 1445 ASSERT(have_read ? 1446 RW_READ_HELD(&dn->dn_struct_rwlock) : 1447 RW_WRITE_HELD(&dn->dn_struct_rwlock)); 1448 1449 /* 1450 * if we have a read-lock, check to see if we need to do any work 1451 * before upgrading to a write-lock. 1452 */ 1453 if (have_read) { 1454 if (blkid <= dn->dn_maxblkid) 1455 return; 1456 1457 if (!rw_tryupgrade(&dn->dn_struct_rwlock)) { 1458 rw_exit(&dn->dn_struct_rwlock); 1459 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 1460 } 1461 } 1462 1463 if (blkid <= dn->dn_maxblkid) 1464 goto out; 1465 1466 dn->dn_maxblkid = blkid; 1467 1468 /* 1469 * Compute the number of levels necessary to support the new maxblkid. 1470 */ 1471 new_nlevels = 1; 1472 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT; 1473 for (sz = dn->dn_nblkptr; 1474 sz <= blkid && sz >= dn->dn_nblkptr; sz <<= epbs) 1475 new_nlevels++; 1476 1477 if (new_nlevels > dn->dn_nlevels) { 1478 int old_nlevels = dn->dn_nlevels; 1479 dmu_buf_impl_t *db; 1480 list_t *list; 1481 dbuf_dirty_record_t *new, *dr, *dr_next; 1482 1483 dn->dn_nlevels = new_nlevels; 1484 1485 ASSERT3U(new_nlevels, >, dn->dn_next_nlevels[txgoff]); 1486 dn->dn_next_nlevels[txgoff] = new_nlevels; 1487 1488 /* dirty the left indirects */ 1489 db = dbuf_hold_level(dn, old_nlevels, 0, FTAG); 1490 ASSERT(db != NULL); 1491 new = dbuf_dirty(db, tx); 1492 dbuf_rele(db, FTAG); 1493 1494 /* transfer the dirty records to the new indirect */ 1495 mutex_enter(&dn->dn_mtx); 1496 mutex_enter(&new->dt.di.dr_mtx); 1497 list = &dn->dn_dirty_records[txgoff]; 1498 for (dr = list_head(list); dr; dr = dr_next) { 1499 dr_next = list_next(&dn->dn_dirty_records[txgoff], dr); 1500 if (dr->dr_dbuf->db_level != new_nlevels-1 && 1501 dr->dr_dbuf->db_blkid != DMU_BONUS_BLKID && 1502 dr->dr_dbuf->db_blkid != DMU_SPILL_BLKID) { 1503 ASSERT(dr->dr_dbuf->db_level == old_nlevels-1); 1504 list_remove(&dn->dn_dirty_records[txgoff], dr); 1505 list_insert_tail(&new->dt.di.dr_children, dr); 1506 dr->dr_parent = new; 1507 } 1508 } 1509 mutex_exit(&new->dt.di.dr_mtx); 1510 mutex_exit(&dn->dn_mtx); 1511 } 1512 1513 out: 1514 if (have_read) 1515 rw_downgrade(&dn->dn_struct_rwlock); 1516 } 1517 1518 static void 1519 dnode_dirty_l1(dnode_t *dn, uint64_t l1blkid, dmu_tx_t *tx) 1520 { 1521 dmu_buf_impl_t *db = dbuf_hold_level(dn, 1, l1blkid, FTAG); 1522 if (db != NULL) { 1523 dmu_buf_will_dirty(&db->db, tx); 1524 dbuf_rele(db, FTAG); 1525 } 1526 } 1527 1528 void 1529 dnode_free_range(dnode_t *dn, uint64_t off, uint64_t len, dmu_tx_t *tx) 1530 { 1531 dmu_buf_impl_t *db; 1532 uint64_t blkoff, blkid, nblks; 1533 int blksz, blkshift, head, tail; 1534 int trunc = FALSE; 1535 int epbs; 1536 1537 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 1538 blksz = dn->dn_datablksz; 1539 blkshift = dn->dn_datablkshift; 1540 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT; 1541 1542 if (len == DMU_OBJECT_END) { 1543 len = UINT64_MAX - off; 1544 trunc = TRUE; 1545 } 1546 1547 /* 1548 * First, block align the region to free: 1549 */ 1550 if (ISP2(blksz)) { 1551 head = P2NPHASE(off, blksz); 1552 blkoff = P2PHASE(off, blksz); 1553 if ((off >> blkshift) > dn->dn_maxblkid) 1554 goto out; 1555 } else { 1556 ASSERT(dn->dn_maxblkid == 0); 1557 if (off == 0 && len >= blksz) { 1558 /* 1559 * Freeing the whole block; fast-track this request. 1560 * Note that we won't dirty any indirect blocks, 1561 * which is fine because we will be freeing the entire 1562 * file and thus all indirect blocks will be freed 1563 * by free_children(). 1564 */ 1565 blkid = 0; 1566 nblks = 1; 1567 goto done; 1568 } else if (off >= blksz) { 1569 /* Freeing past end-of-data */ 1570 goto out; 1571 } else { 1572 /* Freeing part of the block. */ 1573 head = blksz - off; 1574 ASSERT3U(head, >, 0); 1575 } 1576 blkoff = off; 1577 } 1578 /* zero out any partial block data at the start of the range */ 1579 if (head) { 1580 ASSERT3U(blkoff + head, ==, blksz); 1581 if (len < head) 1582 head = len; 1583 if (dbuf_hold_impl(dn, 0, dbuf_whichblock(dn, 0, off), 1584 TRUE, FALSE, FTAG, &db) == 0) { 1585 caddr_t data; 1586 1587 /* don't dirty if it isn't on disk and isn't dirty */ 1588 if (db->db_last_dirty || 1589 (db->db_blkptr && !BP_IS_HOLE(db->db_blkptr))) { 1590 rw_exit(&dn->dn_struct_rwlock); 1591 dmu_buf_will_dirty(&db->db, tx); 1592 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 1593 data = db->db.db_data; 1594 bzero(data + blkoff, head); 1595 } 1596 dbuf_rele(db, FTAG); 1597 } 1598 off += head; 1599 len -= head; 1600 } 1601 1602 /* If the range was less than one block, we're done */ 1603 if (len == 0) 1604 goto out; 1605 1606 /* If the remaining range is past end of file, we're done */ 1607 if ((off >> blkshift) > dn->dn_maxblkid) 1608 goto out; 1609 1610 ASSERT(ISP2(blksz)); 1611 if (trunc) 1612 tail = 0; 1613 else 1614 tail = P2PHASE(len, blksz); 1615 1616 ASSERT0(P2PHASE(off, blksz)); 1617 /* zero out any partial block data at the end of the range */ 1618 if (tail) { 1619 if (len < tail) 1620 tail = len; 1621 if (dbuf_hold_impl(dn, 0, dbuf_whichblock(dn, 0, off+len), 1622 TRUE, FALSE, FTAG, &db) == 0) { 1623 /* don't dirty if not on disk and not dirty */ 1624 if (db->db_last_dirty || 1625 (db->db_blkptr && !BP_IS_HOLE(db->db_blkptr))) { 1626 rw_exit(&dn->dn_struct_rwlock); 1627 dmu_buf_will_dirty(&db->db, tx); 1628 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 1629 bzero(db->db.db_data, tail); 1630 } 1631 dbuf_rele(db, FTAG); 1632 } 1633 len -= tail; 1634 } 1635 1636 /* If the range did not include a full block, we are done */ 1637 if (len == 0) 1638 goto out; 1639 1640 ASSERT(IS_P2ALIGNED(off, blksz)); 1641 ASSERT(trunc || IS_P2ALIGNED(len, blksz)); 1642 blkid = off >> blkshift; 1643 nblks = len >> blkshift; 1644 if (trunc) 1645 nblks += 1; 1646 1647 /* 1648 * Dirty all the indirect blocks in this range. Note that only 1649 * the first and last indirect blocks can actually be written 1650 * (if they were partially freed) -- they must be dirtied, even if 1651 * they do not exist on disk yet. The interior blocks will 1652 * be freed by free_children(), so they will not actually be written. 1653 * Even though these interior blocks will not be written, we 1654 * dirty them for two reasons: 1655 * 1656 * - It ensures that the indirect blocks remain in memory until 1657 * syncing context. (They have already been prefetched by 1658 * dmu_tx_hold_free(), so we don't have to worry about reading 1659 * them serially here.) 1660 * 1661 * - The dirty space accounting will put pressure on the txg sync 1662 * mechanism to begin syncing, and to delay transactions if there 1663 * is a large amount of freeing. Even though these indirect 1664 * blocks will not be written, we could need to write the same 1665 * amount of space if we copy the freed BPs into deadlists. 1666 */ 1667 if (dn->dn_nlevels > 1) { 1668 uint64_t first, last; 1669 1670 first = blkid >> epbs; 1671 dnode_dirty_l1(dn, first, tx); 1672 if (trunc) 1673 last = dn->dn_maxblkid >> epbs; 1674 else 1675 last = (blkid + nblks - 1) >> epbs; 1676 if (last != first) 1677 dnode_dirty_l1(dn, last, tx); 1678 1679 int shift = dn->dn_datablkshift + dn->dn_indblkshift - 1680 SPA_BLKPTRSHIFT; 1681 for (uint64_t i = first + 1; i < last; i++) { 1682 /* 1683 * Set i to the blockid of the next non-hole 1684 * level-1 indirect block at or after i. Note 1685 * that dnode_next_offset() operates in terms of 1686 * level-0-equivalent bytes. 1687 */ 1688 uint64_t ibyte = i << shift; 1689 int err = dnode_next_offset(dn, DNODE_FIND_HAVELOCK, 1690 &ibyte, 2, 1, 0); 1691 i = ibyte >> shift; 1692 if (i >= last) 1693 break; 1694 1695 /* 1696 * Normally we should not see an error, either 1697 * from dnode_next_offset() or dbuf_hold_level() 1698 * (except for ESRCH from dnode_next_offset). 1699 * If there is an i/o error, then when we read 1700 * this block in syncing context, it will use 1701 * ZIO_FLAG_MUSTSUCCEED, and thus hang/panic according 1702 * to the "failmode" property. dnode_next_offset() 1703 * doesn't have a flag to indicate MUSTSUCCEED. 1704 */ 1705 if (err != 0) 1706 break; 1707 1708 dnode_dirty_l1(dn, i, tx); 1709 } 1710 } 1711 1712 done: 1713 /* 1714 * Add this range to the dnode range list. 1715 * We will finish up this free operation in the syncing phase. 1716 */ 1717 mutex_enter(&dn->dn_mtx); 1718 int txgoff = tx->tx_txg & TXG_MASK; 1719 if (dn->dn_free_ranges[txgoff] == NULL) { 1720 dn->dn_free_ranges[txgoff] = 1721 range_tree_create(NULL, NULL, &dn->dn_mtx); 1722 } 1723 range_tree_clear(dn->dn_free_ranges[txgoff], blkid, nblks); 1724 range_tree_add(dn->dn_free_ranges[txgoff], blkid, nblks); 1725 dprintf_dnode(dn, "blkid=%llu nblks=%llu txg=%llu\n", 1726 blkid, nblks, tx->tx_txg); 1727 mutex_exit(&dn->dn_mtx); 1728 1729 dbuf_free_range(dn, blkid, blkid + nblks - 1, tx); 1730 dnode_setdirty(dn, tx); 1731 out: 1732 1733 rw_exit(&dn->dn_struct_rwlock); 1734 } 1735 1736 static boolean_t 1737 dnode_spill_freed(dnode_t *dn) 1738 { 1739 int i; 1740 1741 mutex_enter(&dn->dn_mtx); 1742 for (i = 0; i < TXG_SIZE; i++) { 1743 if (dn->dn_rm_spillblk[i] == DN_KILL_SPILLBLK) 1744 break; 1745 } 1746 mutex_exit(&dn->dn_mtx); 1747 return (i < TXG_SIZE); 1748 } 1749 1750 /* return TRUE if this blkid was freed in a recent txg, or FALSE if it wasn't */ 1751 uint64_t 1752 dnode_block_freed(dnode_t *dn, uint64_t blkid) 1753 { 1754 void *dp = spa_get_dsl(dn->dn_objset->os_spa); 1755 int i; 1756 1757 if (blkid == DMU_BONUS_BLKID) 1758 return (FALSE); 1759 1760 /* 1761 * If we're in the process of opening the pool, dp will not be 1762 * set yet, but there shouldn't be anything dirty. 1763 */ 1764 if (dp == NULL) 1765 return (FALSE); 1766 1767 if (dn->dn_free_txg) 1768 return (TRUE); 1769 1770 if (blkid == DMU_SPILL_BLKID) 1771 return (dnode_spill_freed(dn)); 1772 1773 mutex_enter(&dn->dn_mtx); 1774 for (i = 0; i < TXG_SIZE; i++) { 1775 if (dn->dn_free_ranges[i] != NULL && 1776 range_tree_contains(dn->dn_free_ranges[i], blkid, 1)) 1777 break; 1778 } 1779 mutex_exit(&dn->dn_mtx); 1780 return (i < TXG_SIZE); 1781 } 1782 1783 /* call from syncing context when we actually write/free space for this dnode */ 1784 void 1785 dnode_diduse_space(dnode_t *dn, int64_t delta) 1786 { 1787 uint64_t space; 1788 dprintf_dnode(dn, "dn=%p dnp=%p used=%llu delta=%lld\n", 1789 dn, dn->dn_phys, 1790 (u_longlong_t)dn->dn_phys->dn_used, 1791 (longlong_t)delta); 1792 1793 mutex_enter(&dn->dn_mtx); 1794 space = DN_USED_BYTES(dn->dn_phys); 1795 if (delta > 0) { 1796 ASSERT3U(space + delta, >=, space); /* no overflow */ 1797 } else { 1798 ASSERT3U(space, >=, -delta); /* no underflow */ 1799 } 1800 space += delta; 1801 if (spa_version(dn->dn_objset->os_spa) < SPA_VERSION_DNODE_BYTES) { 1802 ASSERT((dn->dn_phys->dn_flags & DNODE_FLAG_USED_BYTES) == 0); 1803 ASSERT0(P2PHASE(space, 1<<DEV_BSHIFT)); 1804 dn->dn_phys->dn_used = space >> DEV_BSHIFT; 1805 } else { 1806 dn->dn_phys->dn_used = space; 1807 dn->dn_phys->dn_flags |= DNODE_FLAG_USED_BYTES; 1808 } 1809 mutex_exit(&dn->dn_mtx); 1810 } 1811 1812 /* 1813 * Call when we think we're going to write/free space in open context to track 1814 * the amount of memory in use by the currently open txg. 1815 */ 1816 void 1817 dnode_willuse_space(dnode_t *dn, int64_t space, dmu_tx_t *tx) 1818 { 1819 objset_t *os = dn->dn_objset; 1820 dsl_dataset_t *ds = os->os_dsl_dataset; 1821 int64_t aspace = spa_get_asize(os->os_spa, space); 1822 1823 if (ds != NULL) { 1824 dsl_dir_willuse_space(ds->ds_dir, aspace, tx); 1825 dsl_pool_dirty_space(dmu_tx_pool(tx), space, tx); 1826 } 1827 1828 dmu_tx_willuse_space(tx, aspace); 1829 } 1830 1831 /* 1832 * Scans a block at the indicated "level" looking for a hole or data, 1833 * depending on 'flags'. 1834 * 1835 * If level > 0, then we are scanning an indirect block looking at its 1836 * pointers. If level == 0, then we are looking at a block of dnodes. 1837 * 1838 * If we don't find what we are looking for in the block, we return ESRCH. 1839 * Otherwise, return with *offset pointing to the beginning (if searching 1840 * forwards) or end (if searching backwards) of the range covered by the 1841 * block pointer we matched on (or dnode). 1842 * 1843 * The basic search algorithm used below by dnode_next_offset() is to 1844 * use this function to search up the block tree (widen the search) until 1845 * we find something (i.e., we don't return ESRCH) and then search back 1846 * down the tree (narrow the search) until we reach our original search 1847 * level. 1848 */ 1849 static int 1850 dnode_next_offset_level(dnode_t *dn, int flags, uint64_t *offset, 1851 int lvl, uint64_t blkfill, uint64_t txg) 1852 { 1853 dmu_buf_impl_t *db = NULL; 1854 void *data = NULL; 1855 uint64_t epbs = dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT; 1856 uint64_t epb = 1ULL << epbs; 1857 uint64_t minfill, maxfill; 1858 boolean_t hole; 1859 int i, inc, error, span; 1860 1861 dprintf("probing object %llu offset %llx level %d of %u\n", 1862 dn->dn_object, *offset, lvl, dn->dn_phys->dn_nlevels); 1863 1864 hole = ((flags & DNODE_FIND_HOLE) != 0); 1865 inc = (flags & DNODE_FIND_BACKWARDS) ? -1 : 1; 1866 ASSERT(txg == 0 || !hole); 1867 1868 if (lvl == dn->dn_phys->dn_nlevels) { 1869 error = 0; 1870 epb = dn->dn_phys->dn_nblkptr; 1871 data = dn->dn_phys->dn_blkptr; 1872 } else { 1873 uint64_t blkid = dbuf_whichblock(dn, lvl, *offset); 1874 error = dbuf_hold_impl(dn, lvl, blkid, TRUE, FALSE, FTAG, &db); 1875 if (error) { 1876 if (error != ENOENT) 1877 return (error); 1878 if (hole) 1879 return (0); 1880 /* 1881 * This can only happen when we are searching up 1882 * the block tree for data. We don't really need to 1883 * adjust the offset, as we will just end up looking 1884 * at the pointer to this block in its parent, and its 1885 * going to be unallocated, so we will skip over it. 1886 */ 1887 return (SET_ERROR(ESRCH)); 1888 } 1889 error = dbuf_read(db, NULL, DB_RF_CANFAIL | DB_RF_HAVESTRUCT); 1890 if (error) { 1891 dbuf_rele(db, FTAG); 1892 return (error); 1893 } 1894 data = db->db.db_data; 1895 } 1896 1897 1898 if (db != NULL && txg != 0 && (db->db_blkptr == NULL || 1899 db->db_blkptr->blk_birth <= txg || 1900 BP_IS_HOLE(db->db_blkptr))) { 1901 /* 1902 * This can only happen when we are searching up the tree 1903 * and these conditions mean that we need to keep climbing. 1904 */ 1905 error = SET_ERROR(ESRCH); 1906 } else if (lvl == 0) { 1907 dnode_phys_t *dnp = data; 1908 span = DNODE_SHIFT; 1909 ASSERT(dn->dn_type == DMU_OT_DNODE); 1910 1911 for (i = (*offset >> span) & (blkfill - 1); 1912 i >= 0 && i < blkfill; i += inc) { 1913 if ((dnp[i].dn_type == DMU_OT_NONE) == hole) 1914 break; 1915 *offset += (1ULL << span) * inc; 1916 } 1917 if (i < 0 || i == blkfill) 1918 error = SET_ERROR(ESRCH); 1919 } else { 1920 blkptr_t *bp = data; 1921 uint64_t start = *offset; 1922 span = (lvl - 1) * epbs + dn->dn_datablkshift; 1923 minfill = 0; 1924 maxfill = blkfill << ((lvl - 1) * epbs); 1925 1926 if (hole) 1927 maxfill--; 1928 else 1929 minfill++; 1930 1931 *offset = *offset >> span; 1932 for (i = BF64_GET(*offset, 0, epbs); 1933 i >= 0 && i < epb; i += inc) { 1934 if (BP_GET_FILL(&bp[i]) >= minfill && 1935 BP_GET_FILL(&bp[i]) <= maxfill && 1936 (hole || bp[i].blk_birth > txg)) 1937 break; 1938 if (inc > 0 || *offset > 0) 1939 *offset += inc; 1940 } 1941 *offset = *offset << span; 1942 if (inc < 0) { 1943 /* traversing backwards; position offset at the end */ 1944 ASSERT3U(*offset, <=, start); 1945 *offset = MIN(*offset + (1ULL << span) - 1, start); 1946 } else if (*offset < start) { 1947 *offset = start; 1948 } 1949 if (i < 0 || i >= epb) 1950 error = SET_ERROR(ESRCH); 1951 } 1952 1953 if (db) 1954 dbuf_rele(db, FTAG); 1955 1956 return (error); 1957 } 1958 1959 /* 1960 * Find the next hole, data, or sparse region at or after *offset. 1961 * The value 'blkfill' tells us how many items we expect to find 1962 * in an L0 data block; this value is 1 for normal objects, 1963 * DNODES_PER_BLOCK for the meta dnode, and some fraction of 1964 * DNODES_PER_BLOCK when searching for sparse regions thereof. 1965 * 1966 * Examples: 1967 * 1968 * dnode_next_offset(dn, flags, offset, 1, 1, 0); 1969 * Finds the next/previous hole/data in a file. 1970 * Used in dmu_offset_next(). 1971 * 1972 * dnode_next_offset(mdn, flags, offset, 0, DNODES_PER_BLOCK, txg); 1973 * Finds the next free/allocated dnode an objset's meta-dnode. 1974 * Only finds objects that have new contents since txg (ie. 1975 * bonus buffer changes and content removal are ignored). 1976 * Used in dmu_object_next(). 1977 * 1978 * dnode_next_offset(mdn, DNODE_FIND_HOLE, offset, 2, DNODES_PER_BLOCK >> 2, 0); 1979 * Finds the next L2 meta-dnode bp that's at most 1/4 full. 1980 * Used in dmu_object_alloc(). 1981 */ 1982 int 1983 dnode_next_offset(dnode_t *dn, int flags, uint64_t *offset, 1984 int minlvl, uint64_t blkfill, uint64_t txg) 1985 { 1986 uint64_t initial_offset = *offset; 1987 int lvl, maxlvl; 1988 int error = 0; 1989 1990 if (!(flags & DNODE_FIND_HAVELOCK)) 1991 rw_enter(&dn->dn_struct_rwlock, RW_READER); 1992 1993 if (dn->dn_phys->dn_nlevels == 0) { 1994 error = SET_ERROR(ESRCH); 1995 goto out; 1996 } 1997 1998 if (dn->dn_datablkshift == 0) { 1999 if (*offset < dn->dn_datablksz) { 2000 if (flags & DNODE_FIND_HOLE) 2001 *offset = dn->dn_datablksz; 2002 } else { 2003 error = SET_ERROR(ESRCH); 2004 } 2005 goto out; 2006 } 2007 2008 maxlvl = dn->dn_phys->dn_nlevels; 2009 2010 for (lvl = minlvl; lvl <= maxlvl; lvl++) { 2011 error = dnode_next_offset_level(dn, 2012 flags, offset, lvl, blkfill, txg); 2013 if (error != ESRCH) 2014 break; 2015 } 2016 2017 while (error == 0 && --lvl >= minlvl) { 2018 error = dnode_next_offset_level(dn, 2019 flags, offset, lvl, blkfill, txg); 2020 } 2021 2022 /* 2023 * There's always a "virtual hole" at the end of the object, even 2024 * if all BP's which physically exist are non-holes. 2025 */ 2026 if ((flags & DNODE_FIND_HOLE) && error == ESRCH && txg == 0 && 2027 minlvl == 1 && blkfill == 1 && !(flags & DNODE_FIND_BACKWARDS)) { 2028 error = 0; 2029 } 2030 2031 if (error == 0 && (flags & DNODE_FIND_BACKWARDS ? 2032 initial_offset < *offset : initial_offset > *offset)) 2033 error = SET_ERROR(ESRCH); 2034 out: 2035 if (!(flags & DNODE_FIND_HAVELOCK)) 2036 rw_exit(&dn->dn_struct_rwlock); 2037 2038 return (error); 2039 } 2040