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