dnode.c revision 307266
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 42static 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 57static dnode_phys_t dnode_phys_zero; 58 59int zfs_default_bs = SPA_MINBLOCKSHIFT; 60int zfs_default_ibs = DN_MAX_INDBLKSHIFT; 61 62#ifdef illumos 63static kmem_cbrc_t dnode_move(void *, void *, size_t, void *); 64#endif 65 66static int 67dbuf_compare(const void *x1, const void *x2) 68{ 69 const dmu_buf_impl_t *d1 = x1; 70 const dmu_buf_impl_t *d2 = x2; 71 72 if (d1->db_level < d2->db_level) { 73 return (-1); 74 } 75 if (d1->db_level > d2->db_level) { 76 return (1); 77 } 78 79 if (d1->db_blkid < d2->db_blkid) { 80 return (-1); 81 } 82 if (d1->db_blkid > d2->db_blkid) { 83 return (1); 84 } 85 86 if (d1->db_state == DB_SEARCH) { 87 ASSERT3S(d2->db_state, !=, DB_SEARCH); 88 return (-1); 89 } else if (d2->db_state == DB_SEARCH) { 90 ASSERT3S(d1->db_state, !=, DB_SEARCH); 91 return (1); 92 } 93 94 if ((uintptr_t)d1 < (uintptr_t)d2) { 95 return (-1); 96 } 97 if ((uintptr_t)d1 > (uintptr_t)d2) { 98 return (1); 99 } 100 return (0); 101} 102 103/* ARGSUSED */ 104static int 105dnode_cons(void *arg, void *unused, int kmflag) 106{ 107 dnode_t *dn = arg; 108 int i; 109 110 rw_init(&dn->dn_struct_rwlock, NULL, RW_DEFAULT, NULL); 111 mutex_init(&dn->dn_mtx, NULL, MUTEX_DEFAULT, NULL); 112 mutex_init(&dn->dn_dbufs_mtx, NULL, MUTEX_DEFAULT, NULL); 113 cv_init(&dn->dn_notxholds, NULL, CV_DEFAULT, NULL); 114 115 /* 116 * Every dbuf has a reference, and dropping a tracked reference is 117 * O(number of references), so don't track dn_holds. 118 */ 119 refcount_create_untracked(&dn->dn_holds); 120 refcount_create(&dn->dn_tx_holds); 121 list_link_init(&dn->dn_link); 122 123 bzero(&dn->dn_next_nblkptr[0], sizeof (dn->dn_next_nblkptr)); 124 bzero(&dn->dn_next_nlevels[0], sizeof (dn->dn_next_nlevels)); 125 bzero(&dn->dn_next_indblkshift[0], sizeof (dn->dn_next_indblkshift)); 126 bzero(&dn->dn_next_bonustype[0], sizeof (dn->dn_next_bonustype)); 127 bzero(&dn->dn_rm_spillblk[0], sizeof (dn->dn_rm_spillblk)); 128 bzero(&dn->dn_next_bonuslen[0], sizeof (dn->dn_next_bonuslen)); 129 bzero(&dn->dn_next_blksz[0], sizeof (dn->dn_next_blksz)); 130 131 for (i = 0; i < TXG_SIZE; i++) { 132 list_link_init(&dn->dn_dirty_link[i]); 133 dn->dn_free_ranges[i] = NULL; 134 list_create(&dn->dn_dirty_records[i], 135 sizeof (dbuf_dirty_record_t), 136 offsetof(dbuf_dirty_record_t, dr_dirty_node)); 137 } 138 139 dn->dn_allocated_txg = 0; 140 dn->dn_free_txg = 0; 141 dn->dn_assigned_txg = 0; 142 dn->dn_dirtyctx = 0; 143 dn->dn_dirtyctx_firstset = NULL; 144 dn->dn_bonus = NULL; 145 dn->dn_have_spill = B_FALSE; 146 dn->dn_zio = NULL; 147 dn->dn_oldused = 0; 148 dn->dn_oldflags = 0; 149 dn->dn_olduid = 0; 150 dn->dn_oldgid = 0; 151 dn->dn_newuid = 0; 152 dn->dn_newgid = 0; 153 dn->dn_id_flags = 0; 154 155 dn->dn_dbufs_count = 0; 156 dn->dn_unlisted_l0_blkid = 0; 157 avl_create(&dn->dn_dbufs, dbuf_compare, sizeof (dmu_buf_impl_t), 158 offsetof(dmu_buf_impl_t, db_link)); 159 160 dn->dn_moved = 0; 161 POINTER_INVALIDATE(&dn->dn_objset); 162 return (0); 163} 164 165/* ARGSUSED */ 166static void 167dnode_dest(void *arg, void *unused) 168{ 169 int i; 170 dnode_t *dn = arg; 171 172 rw_destroy(&dn->dn_struct_rwlock); 173 mutex_destroy(&dn->dn_mtx); 174 mutex_destroy(&dn->dn_dbufs_mtx); 175 cv_destroy(&dn->dn_notxholds); 176 refcount_destroy(&dn->dn_holds); 177 refcount_destroy(&dn->dn_tx_holds); 178 ASSERT(!list_link_active(&dn->dn_link)); 179 180 for (i = 0; i < TXG_SIZE; i++) { 181 ASSERT(!list_link_active(&dn->dn_dirty_link[i])); 182 ASSERT3P(dn->dn_free_ranges[i], ==, NULL); 183 list_destroy(&dn->dn_dirty_records[i]); 184 ASSERT0(dn->dn_next_nblkptr[i]); 185 ASSERT0(dn->dn_next_nlevels[i]); 186 ASSERT0(dn->dn_next_indblkshift[i]); 187 ASSERT0(dn->dn_next_bonustype[i]); 188 ASSERT0(dn->dn_rm_spillblk[i]); 189 ASSERT0(dn->dn_next_bonuslen[i]); 190 ASSERT0(dn->dn_next_blksz[i]); 191 } 192 193 ASSERT0(dn->dn_allocated_txg); 194 ASSERT0(dn->dn_free_txg); 195 ASSERT0(dn->dn_assigned_txg); 196 ASSERT0(dn->dn_dirtyctx); 197 ASSERT3P(dn->dn_dirtyctx_firstset, ==, NULL); 198 ASSERT3P(dn->dn_bonus, ==, NULL); 199 ASSERT(!dn->dn_have_spill); 200 ASSERT3P(dn->dn_zio, ==, NULL); 201 ASSERT0(dn->dn_oldused); 202 ASSERT0(dn->dn_oldflags); 203 ASSERT0(dn->dn_olduid); 204 ASSERT0(dn->dn_oldgid); 205 ASSERT0(dn->dn_newuid); 206 ASSERT0(dn->dn_newgid); 207 ASSERT0(dn->dn_id_flags); 208 209 ASSERT0(dn->dn_dbufs_count); 210 ASSERT0(dn->dn_unlisted_l0_blkid); 211 avl_destroy(&dn->dn_dbufs); 212} 213 214void 215dnode_init(void) 216{ 217 ASSERT(dnode_cache == NULL); 218 dnode_cache = kmem_cache_create("dnode_t", 219 sizeof (dnode_t), 220 0, dnode_cons, dnode_dest, NULL, NULL, NULL, 0); 221 kmem_cache_set_move(dnode_cache, dnode_move); 222} 223 224void 225dnode_fini(void) 226{ 227 kmem_cache_destroy(dnode_cache); 228 dnode_cache = NULL; 229} 230 231 232#ifdef ZFS_DEBUG 233void 234dnode_verify(dnode_t *dn) 235{ 236 int drop_struct_lock = FALSE; 237 238 ASSERT(dn->dn_phys); 239 ASSERT(dn->dn_objset); 240 ASSERT(dn->dn_handle->dnh_dnode == dn); 241 242 ASSERT(DMU_OT_IS_VALID(dn->dn_phys->dn_type)); 243 244 if (!(zfs_flags & ZFS_DEBUG_DNODE_VERIFY)) 245 return; 246 247 if (!RW_WRITE_HELD(&dn->dn_struct_rwlock)) { 248 rw_enter(&dn->dn_struct_rwlock, RW_READER); 249 drop_struct_lock = TRUE; 250 } 251 if (dn->dn_phys->dn_type != DMU_OT_NONE || dn->dn_allocated_txg != 0) { 252 int i; 253 ASSERT3U(dn->dn_indblkshift, >=, 0); 254 ASSERT3U(dn->dn_indblkshift, <=, SPA_MAXBLOCKSHIFT); 255 if (dn->dn_datablkshift) { 256 ASSERT3U(dn->dn_datablkshift, >=, SPA_MINBLOCKSHIFT); 257 ASSERT3U(dn->dn_datablkshift, <=, SPA_MAXBLOCKSHIFT); 258 ASSERT3U(1<<dn->dn_datablkshift, ==, dn->dn_datablksz); 259 } 260 ASSERT3U(dn->dn_nlevels, <=, 30); 261 ASSERT(DMU_OT_IS_VALID(dn->dn_type)); 262 ASSERT3U(dn->dn_nblkptr, >=, 1); 263 ASSERT3U(dn->dn_nblkptr, <=, DN_MAX_NBLKPTR); 264 ASSERT3U(dn->dn_bonuslen, <=, DN_MAX_BONUSLEN); 265 ASSERT3U(dn->dn_datablksz, ==, 266 dn->dn_datablkszsec << SPA_MINBLOCKSHIFT); 267 ASSERT3U(ISP2(dn->dn_datablksz), ==, dn->dn_datablkshift != 0); 268 ASSERT3U((dn->dn_nblkptr - 1) * sizeof (blkptr_t) + 269 dn->dn_bonuslen, <=, DN_MAX_BONUSLEN); 270 for (i = 0; i < TXG_SIZE; i++) { 271 ASSERT3U(dn->dn_next_nlevels[i], <=, dn->dn_nlevels); 272 } 273 } 274 if (dn->dn_phys->dn_type != DMU_OT_NONE) 275 ASSERT3U(dn->dn_phys->dn_nlevels, <=, dn->dn_nlevels); 276 ASSERT(DMU_OBJECT_IS_SPECIAL(dn->dn_object) || dn->dn_dbuf != NULL); 277 if (dn->dn_dbuf != NULL) { 278 ASSERT3P(dn->dn_phys, ==, 279 (dnode_phys_t *)dn->dn_dbuf->db.db_data + 280 (dn->dn_object % (dn->dn_dbuf->db.db_size >> DNODE_SHIFT))); 281 } 282 if (drop_struct_lock) 283 rw_exit(&dn->dn_struct_rwlock); 284} 285#endif 286 287void 288dnode_byteswap(dnode_phys_t *dnp) 289{ 290 uint64_t *buf64 = (void*)&dnp->dn_blkptr; 291 int i; 292 293 if (dnp->dn_type == DMU_OT_NONE) { 294 bzero(dnp, sizeof (dnode_phys_t)); 295 return; 296 } 297 298 dnp->dn_datablkszsec = BSWAP_16(dnp->dn_datablkszsec); 299 dnp->dn_bonuslen = BSWAP_16(dnp->dn_bonuslen); 300 dnp->dn_maxblkid = BSWAP_64(dnp->dn_maxblkid); 301 dnp->dn_used = BSWAP_64(dnp->dn_used); 302 303 /* 304 * dn_nblkptr is only one byte, so it's OK to read it in either 305 * byte order. We can't read dn_bouslen. 306 */ 307 ASSERT(dnp->dn_indblkshift <= SPA_MAXBLOCKSHIFT); 308 ASSERT(dnp->dn_nblkptr <= DN_MAX_NBLKPTR); 309 for (i = 0; i < dnp->dn_nblkptr * sizeof (blkptr_t)/8; i++) 310 buf64[i] = BSWAP_64(buf64[i]); 311 312 /* 313 * OK to check dn_bonuslen for zero, because it won't matter if 314 * we have the wrong byte order. This is necessary because the 315 * dnode dnode is smaller than a regular dnode. 316 */ 317 if (dnp->dn_bonuslen != 0) { 318 /* 319 * Note that the bonus length calculated here may be 320 * longer than the actual bonus buffer. This is because 321 * we always put the bonus buffer after the last block 322 * pointer (instead of packing it against the end of the 323 * dnode buffer). 324 */ 325 int off = (dnp->dn_nblkptr-1) * sizeof (blkptr_t); 326 size_t len = DN_MAX_BONUSLEN - off; 327 ASSERT(DMU_OT_IS_VALID(dnp->dn_bonustype)); 328 dmu_object_byteswap_t byteswap = 329 DMU_OT_BYTESWAP(dnp->dn_bonustype); 330 dmu_ot_byteswap[byteswap].ob_func(dnp->dn_bonus + off, len); 331 } 332 333 /* Swap SPILL block if we have one */ 334 if (dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) 335 byteswap_uint64_array(&dnp->dn_spill, sizeof (blkptr_t)); 336 337} 338 339void 340dnode_buf_byteswap(void *vbuf, size_t size) 341{ 342 dnode_phys_t *buf = vbuf; 343 int i; 344 345 ASSERT3U(sizeof (dnode_phys_t), ==, (1<<DNODE_SHIFT)); 346 ASSERT((size & (sizeof (dnode_phys_t)-1)) == 0); 347 348 size >>= DNODE_SHIFT; 349 for (i = 0; i < size; i++) { 350 dnode_byteswap(buf); 351 buf++; 352 } 353} 354 355void 356dnode_setbonuslen(dnode_t *dn, int newsize, dmu_tx_t *tx) 357{ 358 ASSERT3U(refcount_count(&dn->dn_holds), >=, 1); 359 360 dnode_setdirty(dn, tx); 361 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 362 ASSERT3U(newsize, <=, DN_MAX_BONUSLEN - 363 (dn->dn_nblkptr-1) * sizeof (blkptr_t)); 364 dn->dn_bonuslen = newsize; 365 if (newsize == 0) 366 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = DN_ZERO_BONUSLEN; 367 else 368 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = dn->dn_bonuslen; 369 rw_exit(&dn->dn_struct_rwlock); 370} 371 372void 373dnode_setbonus_type(dnode_t *dn, dmu_object_type_t newtype, dmu_tx_t *tx) 374{ 375 ASSERT3U(refcount_count(&dn->dn_holds), >=, 1); 376 dnode_setdirty(dn, tx); 377 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 378 dn->dn_bonustype = newtype; 379 dn->dn_next_bonustype[tx->tx_txg & TXG_MASK] = dn->dn_bonustype; 380 rw_exit(&dn->dn_struct_rwlock); 381} 382 383void 384dnode_rm_spill(dnode_t *dn, dmu_tx_t *tx) 385{ 386 ASSERT3U(refcount_count(&dn->dn_holds), >=, 1); 387 ASSERT(RW_WRITE_HELD(&dn->dn_struct_rwlock)); 388 dnode_setdirty(dn, tx); 389 dn->dn_rm_spillblk[tx->tx_txg&TXG_MASK] = DN_KILL_SPILLBLK; 390 dn->dn_have_spill = B_FALSE; 391} 392 393static void 394dnode_setdblksz(dnode_t *dn, int size) 395{ 396 ASSERT0(P2PHASE(size, SPA_MINBLOCKSIZE)); 397 ASSERT3U(size, <=, SPA_MAXBLOCKSIZE); 398 ASSERT3U(size, >=, SPA_MINBLOCKSIZE); 399 ASSERT3U(size >> SPA_MINBLOCKSHIFT, <, 400 1<<(sizeof (dn->dn_phys->dn_datablkszsec) * 8)); 401 dn->dn_datablksz = size; 402 dn->dn_datablkszsec = size >> SPA_MINBLOCKSHIFT; 403 dn->dn_datablkshift = ISP2(size) ? highbit64(size - 1) : 0; 404} 405 406static dnode_t * 407dnode_create(objset_t *os, dnode_phys_t *dnp, dmu_buf_impl_t *db, 408 uint64_t object, dnode_handle_t *dnh) 409{ 410 dnode_t *dn; 411 412 dn = kmem_cache_alloc(dnode_cache, KM_SLEEP); 413 ASSERT(!POINTER_IS_VALID(dn->dn_objset)); 414 dn->dn_moved = 0; 415 416 /* 417 * Defer setting dn_objset until the dnode is ready to be a candidate 418 * for the dnode_move() callback. 419 */ 420 dn->dn_object = object; 421 dn->dn_dbuf = db; 422 dn->dn_handle = dnh; 423 dn->dn_phys = dnp; 424 425 if (dnp->dn_datablkszsec) { 426 dnode_setdblksz(dn, dnp->dn_datablkszsec << SPA_MINBLOCKSHIFT); 427 } else { 428 dn->dn_datablksz = 0; 429 dn->dn_datablkszsec = 0; 430 dn->dn_datablkshift = 0; 431 } 432 dn->dn_indblkshift = dnp->dn_indblkshift; 433 dn->dn_nlevels = dnp->dn_nlevels; 434 dn->dn_type = dnp->dn_type; 435 dn->dn_nblkptr = dnp->dn_nblkptr; 436 dn->dn_checksum = dnp->dn_checksum; 437 dn->dn_compress = dnp->dn_compress; 438 dn->dn_bonustype = dnp->dn_bonustype; 439 dn->dn_bonuslen = dnp->dn_bonuslen; 440 dn->dn_maxblkid = dnp->dn_maxblkid; 441 dn->dn_have_spill = ((dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) != 0); 442 dn->dn_id_flags = 0; 443 444 dmu_zfetch_init(&dn->dn_zfetch, dn); 445 446 ASSERT(DMU_OT_IS_VALID(dn->dn_phys->dn_type)); 447 448 mutex_enter(&os->os_lock); 449 if (dnh->dnh_dnode != NULL) { 450 /* Lost the allocation race. */ 451 mutex_exit(&os->os_lock); 452 kmem_cache_free(dnode_cache, dn); 453 return (dnh->dnh_dnode); 454 } 455 456 /* 457 * Exclude special dnodes from os_dnodes so an empty os_dnodes 458 * signifies that the special dnodes have no references from 459 * their children (the entries in os_dnodes). This allows 460 * dnode_destroy() to easily determine if the last child has 461 * been removed and then complete eviction of the objset. 462 */ 463 if (!DMU_OBJECT_IS_SPECIAL(object)) 464 list_insert_head(&os->os_dnodes, dn); 465 membar_producer(); 466 467 /* 468 * Everything else must be valid before assigning dn_objset 469 * makes the dnode eligible for dnode_move(). 470 */ 471 dn->dn_objset = os; 472 473 dnh->dnh_dnode = dn; 474 mutex_exit(&os->os_lock); 475 476 arc_space_consume(sizeof (dnode_t), ARC_SPACE_OTHER); 477 return (dn); 478} 479 480/* 481 * Caller must be holding the dnode handle, which is released upon return. 482 */ 483static void 484dnode_destroy(dnode_t *dn) 485{ 486 objset_t *os = dn->dn_objset; 487 boolean_t complete_os_eviction = B_FALSE; 488 489 ASSERT((dn->dn_id_flags & DN_ID_NEW_EXIST) == 0); 490 491 mutex_enter(&os->os_lock); 492 POINTER_INVALIDATE(&dn->dn_objset); 493 if (!DMU_OBJECT_IS_SPECIAL(dn->dn_object)) { 494 list_remove(&os->os_dnodes, dn); 495 complete_os_eviction = 496 list_is_empty(&os->os_dnodes) && 497 list_link_active(&os->os_evicting_node); 498 } 499 mutex_exit(&os->os_lock); 500 501 /* the dnode can no longer move, so we can release the handle */ 502 zrl_remove(&dn->dn_handle->dnh_zrlock); 503 504 dn->dn_allocated_txg = 0; 505 dn->dn_free_txg = 0; 506 dn->dn_assigned_txg = 0; 507 508 dn->dn_dirtyctx = 0; 509 if (dn->dn_dirtyctx_firstset != NULL) { 510 kmem_free(dn->dn_dirtyctx_firstset, 1); 511 dn->dn_dirtyctx_firstset = NULL; 512 } 513 if (dn->dn_bonus != NULL) { 514 mutex_enter(&dn->dn_bonus->db_mtx); 515 dbuf_destroy(dn->dn_bonus); 516 dn->dn_bonus = NULL; 517 } 518 dn->dn_zio = NULL; 519 520 dn->dn_have_spill = B_FALSE; 521 dn->dn_oldused = 0; 522 dn->dn_oldflags = 0; 523 dn->dn_olduid = 0; 524 dn->dn_oldgid = 0; 525 dn->dn_newuid = 0; 526 dn->dn_newgid = 0; 527 dn->dn_id_flags = 0; 528 dn->dn_unlisted_l0_blkid = 0; 529 530 dmu_zfetch_fini(&dn->dn_zfetch); 531 kmem_cache_free(dnode_cache, dn); 532 arc_space_return(sizeof (dnode_t), ARC_SPACE_OTHER); 533 534 if (complete_os_eviction) 535 dmu_objset_evict_done(os); 536} 537 538void 539dnode_allocate(dnode_t *dn, dmu_object_type_t ot, int blocksize, int ibs, 540 dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx) 541{ 542 int i; 543 544 ASSERT3U(blocksize, <=, 545 spa_maxblocksize(dmu_objset_spa(dn->dn_objset))); 546 if (blocksize == 0) 547 blocksize = 1 << zfs_default_bs; 548 else 549 blocksize = P2ROUNDUP(blocksize, SPA_MINBLOCKSIZE); 550 551 if (ibs == 0) 552 ibs = zfs_default_ibs; 553 554 ibs = MIN(MAX(ibs, DN_MIN_INDBLKSHIFT), DN_MAX_INDBLKSHIFT); 555 556 dprintf("os=%p obj=%llu txg=%llu blocksize=%d ibs=%d\n", dn->dn_objset, 557 dn->dn_object, tx->tx_txg, blocksize, ibs); 558 559 ASSERT(dn->dn_type == DMU_OT_NONE); 560 ASSERT(bcmp(dn->dn_phys, &dnode_phys_zero, sizeof (dnode_phys_t)) == 0); 561 ASSERT(dn->dn_phys->dn_type == DMU_OT_NONE); 562 ASSERT(ot != DMU_OT_NONE); 563 ASSERT(DMU_OT_IS_VALID(ot)); 564 ASSERT((bonustype == DMU_OT_NONE && bonuslen == 0) || 565 (bonustype == DMU_OT_SA && bonuslen == 0) || 566 (bonustype != DMU_OT_NONE && bonuslen != 0)); 567 ASSERT(DMU_OT_IS_VALID(bonustype)); 568 ASSERT3U(bonuslen, <=, DN_MAX_BONUSLEN); 569 ASSERT(dn->dn_type == DMU_OT_NONE); 570 ASSERT0(dn->dn_maxblkid); 571 ASSERT0(dn->dn_allocated_txg); 572 ASSERT0(dn->dn_assigned_txg); 573 ASSERT(refcount_is_zero(&dn->dn_tx_holds)); 574 ASSERT3U(refcount_count(&dn->dn_holds), <=, 1); 575 ASSERT(avl_is_empty(&dn->dn_dbufs)); 576 577 for (i = 0; i < TXG_SIZE; i++) { 578 ASSERT0(dn->dn_next_nblkptr[i]); 579 ASSERT0(dn->dn_next_nlevels[i]); 580 ASSERT0(dn->dn_next_indblkshift[i]); 581 ASSERT0(dn->dn_next_bonuslen[i]); 582 ASSERT0(dn->dn_next_bonustype[i]); 583 ASSERT0(dn->dn_rm_spillblk[i]); 584 ASSERT0(dn->dn_next_blksz[i]); 585 ASSERT(!list_link_active(&dn->dn_dirty_link[i])); 586 ASSERT3P(list_head(&dn->dn_dirty_records[i]), ==, NULL); 587 ASSERT3P(dn->dn_free_ranges[i], ==, NULL); 588 } 589 590 dn->dn_type = ot; 591 dnode_setdblksz(dn, blocksize); 592 dn->dn_indblkshift = ibs; 593 dn->dn_nlevels = 1; 594 if (bonustype == DMU_OT_SA) /* Maximize bonus space for SA */ 595 dn->dn_nblkptr = 1; 596 else 597 dn->dn_nblkptr = 1 + 598 ((DN_MAX_BONUSLEN - bonuslen) >> SPA_BLKPTRSHIFT); 599 dn->dn_bonustype = bonustype; 600 dn->dn_bonuslen = bonuslen; 601 dn->dn_checksum = ZIO_CHECKSUM_INHERIT; 602 dn->dn_compress = ZIO_COMPRESS_INHERIT; 603 dn->dn_dirtyctx = 0; 604 605 dn->dn_free_txg = 0; 606 if (dn->dn_dirtyctx_firstset) { 607 kmem_free(dn->dn_dirtyctx_firstset, 1); 608 dn->dn_dirtyctx_firstset = NULL; 609 } 610 611 dn->dn_allocated_txg = tx->tx_txg; 612 dn->dn_id_flags = 0; 613 614 dnode_setdirty(dn, tx); 615 dn->dn_next_indblkshift[tx->tx_txg & TXG_MASK] = ibs; 616 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = dn->dn_bonuslen; 617 dn->dn_next_bonustype[tx->tx_txg & TXG_MASK] = dn->dn_bonustype; 618 dn->dn_next_blksz[tx->tx_txg & TXG_MASK] = dn->dn_datablksz; 619} 620 621void 622dnode_reallocate(dnode_t *dn, dmu_object_type_t ot, int blocksize, 623 dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx) 624{ 625 int nblkptr; 626 627 ASSERT3U(blocksize, >=, SPA_MINBLOCKSIZE); 628 ASSERT3U(blocksize, <=, 629 spa_maxblocksize(dmu_objset_spa(dn->dn_objset))); 630 ASSERT0(blocksize % SPA_MINBLOCKSIZE); 631 ASSERT(dn->dn_object != DMU_META_DNODE_OBJECT || dmu_tx_private_ok(tx)); 632 ASSERT(tx->tx_txg != 0); 633 ASSERT((bonustype == DMU_OT_NONE && bonuslen == 0) || 634 (bonustype != DMU_OT_NONE && bonuslen != 0) || 635 (bonustype == DMU_OT_SA && bonuslen == 0)); 636 ASSERT(DMU_OT_IS_VALID(bonustype)); 637 ASSERT3U(bonuslen, <=, DN_MAX_BONUSLEN); 638 639 /* clean up any unreferenced dbufs */ 640 dnode_evict_dbufs(dn); 641 642 dn->dn_id_flags = 0; 643 644 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 645 dnode_setdirty(dn, tx); 646 if (dn->dn_datablksz != blocksize) { 647 /* change blocksize */ 648 ASSERT(dn->dn_maxblkid == 0 && 649 (BP_IS_HOLE(&dn->dn_phys->dn_blkptr[0]) || 650 dnode_block_freed(dn, 0))); 651 dnode_setdblksz(dn, blocksize); 652 dn->dn_next_blksz[tx->tx_txg&TXG_MASK] = blocksize; 653 } 654 if (dn->dn_bonuslen != bonuslen) 655 dn->dn_next_bonuslen[tx->tx_txg&TXG_MASK] = bonuslen; 656 657 if (bonustype == DMU_OT_SA) /* Maximize bonus space for SA */ 658 nblkptr = 1; 659 else 660 nblkptr = 1 + ((DN_MAX_BONUSLEN - bonuslen) >> SPA_BLKPTRSHIFT); 661 if (dn->dn_bonustype != bonustype) 662 dn->dn_next_bonustype[tx->tx_txg&TXG_MASK] = bonustype; 663 if (dn->dn_nblkptr != nblkptr) 664 dn->dn_next_nblkptr[tx->tx_txg&TXG_MASK] = nblkptr; 665 if (dn->dn_phys->dn_flags & DNODE_FLAG_SPILL_BLKPTR) { 666 dbuf_rm_spill(dn, tx); 667 dnode_rm_spill(dn, tx); 668 } 669 rw_exit(&dn->dn_struct_rwlock); 670 671 /* change type */ 672 dn->dn_type = ot; 673 674 /* change bonus size and type */ 675 mutex_enter(&dn->dn_mtx); 676 dn->dn_bonustype = bonustype; 677 dn->dn_bonuslen = bonuslen; 678 dn->dn_nblkptr = nblkptr; 679 dn->dn_checksum = ZIO_CHECKSUM_INHERIT; 680 dn->dn_compress = ZIO_COMPRESS_INHERIT; 681 ASSERT3U(dn->dn_nblkptr, <=, DN_MAX_NBLKPTR); 682 683 /* fix up the bonus db_size */ 684 if (dn->dn_bonus) { 685 dn->dn_bonus->db.db_size = 686 DN_MAX_BONUSLEN - (dn->dn_nblkptr-1) * sizeof (blkptr_t); 687 ASSERT(dn->dn_bonuslen <= dn->dn_bonus->db.db_size); 688 } 689 690 dn->dn_allocated_txg = tx->tx_txg; 691 mutex_exit(&dn->dn_mtx); 692} 693 694#ifdef DNODE_STATS 695static struct { 696 uint64_t dms_dnode_invalid; 697 uint64_t dms_dnode_recheck1; 698 uint64_t dms_dnode_recheck2; 699 uint64_t dms_dnode_special; 700 uint64_t dms_dnode_handle; 701 uint64_t dms_dnode_rwlock; 702 uint64_t dms_dnode_active; 703} dnode_move_stats; 704#endif /* DNODE_STATS */ 705 706static void 707dnode_move_impl(dnode_t *odn, dnode_t *ndn) 708{ 709 int i; 710 711 ASSERT(!RW_LOCK_HELD(&odn->dn_struct_rwlock)); 712 ASSERT(MUTEX_NOT_HELD(&odn->dn_mtx)); 713 ASSERT(MUTEX_NOT_HELD(&odn->dn_dbufs_mtx)); 714 ASSERT(!RW_LOCK_HELD(&odn->dn_zfetch.zf_rwlock)); 715 716 /* Copy fields. */ 717 ndn->dn_objset = odn->dn_objset; 718 ndn->dn_object = odn->dn_object; 719 ndn->dn_dbuf = odn->dn_dbuf; 720 ndn->dn_handle = odn->dn_handle; 721 ndn->dn_phys = odn->dn_phys; 722 ndn->dn_type = odn->dn_type; 723 ndn->dn_bonuslen = odn->dn_bonuslen; 724 ndn->dn_bonustype = odn->dn_bonustype; 725 ndn->dn_nblkptr = odn->dn_nblkptr; 726 ndn->dn_checksum = odn->dn_checksum; 727 ndn->dn_compress = odn->dn_compress; 728 ndn->dn_nlevels = odn->dn_nlevels; 729 ndn->dn_indblkshift = odn->dn_indblkshift; 730 ndn->dn_datablkshift = odn->dn_datablkshift; 731 ndn->dn_datablkszsec = odn->dn_datablkszsec; 732 ndn->dn_datablksz = odn->dn_datablksz; 733 ndn->dn_maxblkid = odn->dn_maxblkid; 734 bcopy(&odn->dn_next_nblkptr[0], &ndn->dn_next_nblkptr[0], 735 sizeof (odn->dn_next_nblkptr)); 736 bcopy(&odn->dn_next_nlevels[0], &ndn->dn_next_nlevels[0], 737 sizeof (odn->dn_next_nlevels)); 738 bcopy(&odn->dn_next_indblkshift[0], &ndn->dn_next_indblkshift[0], 739 sizeof (odn->dn_next_indblkshift)); 740 bcopy(&odn->dn_next_bonustype[0], &ndn->dn_next_bonustype[0], 741 sizeof (odn->dn_next_bonustype)); 742 bcopy(&odn->dn_rm_spillblk[0], &ndn->dn_rm_spillblk[0], 743 sizeof (odn->dn_rm_spillblk)); 744 bcopy(&odn->dn_next_bonuslen[0], &ndn->dn_next_bonuslen[0], 745 sizeof (odn->dn_next_bonuslen)); 746 bcopy(&odn->dn_next_blksz[0], &ndn->dn_next_blksz[0], 747 sizeof (odn->dn_next_blksz)); 748 for (i = 0; i < TXG_SIZE; i++) { 749 list_move_tail(&ndn->dn_dirty_records[i], 750 &odn->dn_dirty_records[i]); 751 } 752 bcopy(&odn->dn_free_ranges[0], &ndn->dn_free_ranges[0], 753 sizeof (odn->dn_free_ranges)); 754 ndn->dn_allocated_txg = odn->dn_allocated_txg; 755 ndn->dn_free_txg = odn->dn_free_txg; 756 ndn->dn_assigned_txg = odn->dn_assigned_txg; 757 ndn->dn_dirtyctx = odn->dn_dirtyctx; 758 ndn->dn_dirtyctx_firstset = odn->dn_dirtyctx_firstset; 759 ASSERT(refcount_count(&odn->dn_tx_holds) == 0); 760 refcount_transfer(&ndn->dn_holds, &odn->dn_holds); 761 ASSERT(avl_is_empty(&ndn->dn_dbufs)); 762 avl_swap(&ndn->dn_dbufs, &odn->dn_dbufs); 763 ndn->dn_dbufs_count = odn->dn_dbufs_count; 764 ndn->dn_unlisted_l0_blkid = odn->dn_unlisted_l0_blkid; 765 ndn->dn_bonus = odn->dn_bonus; 766 ndn->dn_have_spill = odn->dn_have_spill; 767 ndn->dn_zio = odn->dn_zio; 768 ndn->dn_oldused = odn->dn_oldused; 769 ndn->dn_oldflags = odn->dn_oldflags; 770 ndn->dn_olduid = odn->dn_olduid; 771 ndn->dn_oldgid = odn->dn_oldgid; 772 ndn->dn_newuid = odn->dn_newuid; 773 ndn->dn_newgid = odn->dn_newgid; 774 ndn->dn_id_flags = odn->dn_id_flags; 775 dmu_zfetch_init(&ndn->dn_zfetch, NULL); 776 list_move_tail(&ndn->dn_zfetch.zf_stream, &odn->dn_zfetch.zf_stream); 777 ndn->dn_zfetch.zf_dnode = odn->dn_zfetch.zf_dnode; 778 779 /* 780 * Update back pointers. Updating the handle fixes the back pointer of 781 * every descendant dbuf as well as the bonus dbuf. 782 */ 783 ASSERT(ndn->dn_handle->dnh_dnode == odn); 784 ndn->dn_handle->dnh_dnode = ndn; 785 if (ndn->dn_zfetch.zf_dnode == odn) { 786 ndn->dn_zfetch.zf_dnode = ndn; 787 } 788 789 /* 790 * Invalidate the original dnode by clearing all of its back pointers. 791 */ 792 odn->dn_dbuf = NULL; 793 odn->dn_handle = NULL; 794 avl_create(&odn->dn_dbufs, dbuf_compare, sizeof (dmu_buf_impl_t), 795 offsetof(dmu_buf_impl_t, db_link)); 796 odn->dn_dbufs_count = 0; 797 odn->dn_unlisted_l0_blkid = 0; 798 odn->dn_bonus = NULL; 799 odn->dn_zfetch.zf_dnode = NULL; 800 801 /* 802 * Set the low bit of the objset pointer to ensure that dnode_move() 803 * recognizes the dnode as invalid in any subsequent callback. 804 */ 805 POINTER_INVALIDATE(&odn->dn_objset); 806 807 /* 808 * Satisfy the destructor. 809 */ 810 for (i = 0; i < TXG_SIZE; i++) { 811 list_create(&odn->dn_dirty_records[i], 812 sizeof (dbuf_dirty_record_t), 813 offsetof(dbuf_dirty_record_t, dr_dirty_node)); 814 odn->dn_free_ranges[i] = NULL; 815 odn->dn_next_nlevels[i] = 0; 816 odn->dn_next_indblkshift[i] = 0; 817 odn->dn_next_bonustype[i] = 0; 818 odn->dn_rm_spillblk[i] = 0; 819 odn->dn_next_bonuslen[i] = 0; 820 odn->dn_next_blksz[i] = 0; 821 } 822 odn->dn_allocated_txg = 0; 823 odn->dn_free_txg = 0; 824 odn->dn_assigned_txg = 0; 825 odn->dn_dirtyctx = 0; 826 odn->dn_dirtyctx_firstset = NULL; 827 odn->dn_have_spill = B_FALSE; 828 odn->dn_zio = NULL; 829 odn->dn_oldused = 0; 830 odn->dn_oldflags = 0; 831 odn->dn_olduid = 0; 832 odn->dn_oldgid = 0; 833 odn->dn_newuid = 0; 834 odn->dn_newgid = 0; 835 odn->dn_id_flags = 0; 836 837 /* 838 * Mark the dnode. 839 */ 840 ndn->dn_moved = 1; 841 odn->dn_moved = (uint8_t)-1; 842} 843 844#ifdef illumos 845#ifdef _KERNEL 846/*ARGSUSED*/ 847static kmem_cbrc_t 848dnode_move(void *buf, void *newbuf, size_t size, void *arg) 849{ 850 dnode_t *odn = buf, *ndn = newbuf; 851 objset_t *os; 852 int64_t refcount; 853 uint32_t dbufs; 854 855 /* 856 * The dnode is on the objset's list of known dnodes if the objset 857 * pointer is valid. We set the low bit of the objset pointer when 858 * freeing the dnode to invalidate it, and the memory patterns written 859 * by kmem (baddcafe and deadbeef) set at least one of the two low bits. 860 * A newly created dnode sets the objset pointer last of all to indicate 861 * that the dnode is known and in a valid state to be moved by this 862 * function. 863 */ 864 os = odn->dn_objset; 865 if (!POINTER_IS_VALID(os)) { 866 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_invalid); 867 return (KMEM_CBRC_DONT_KNOW); 868 } 869 870 /* 871 * Ensure that the objset does not go away during the move. 872 */ 873 rw_enter(&os_lock, RW_WRITER); 874 if (os != odn->dn_objset) { 875 rw_exit(&os_lock); 876 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_recheck1); 877 return (KMEM_CBRC_DONT_KNOW); 878 } 879 880 /* 881 * If the dnode is still valid, then so is the objset. We know that no 882 * valid objset can be freed while we hold os_lock, so we can safely 883 * ensure that the objset remains in use. 884 */ 885 mutex_enter(&os->os_lock); 886 887 /* 888 * Recheck the objset pointer in case the dnode was removed just before 889 * acquiring the lock. 890 */ 891 if (os != odn->dn_objset) { 892 mutex_exit(&os->os_lock); 893 rw_exit(&os_lock); 894 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_recheck2); 895 return (KMEM_CBRC_DONT_KNOW); 896 } 897 898 /* 899 * At this point we know that as long as we hold os->os_lock, the dnode 900 * cannot be freed and fields within the dnode can be safely accessed. 901 * The objset listing this dnode cannot go away as long as this dnode is 902 * on its list. 903 */ 904 rw_exit(&os_lock); 905 if (DMU_OBJECT_IS_SPECIAL(odn->dn_object)) { 906 mutex_exit(&os->os_lock); 907 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_special); 908 return (KMEM_CBRC_NO); 909 } 910 ASSERT(odn->dn_dbuf != NULL); /* only "special" dnodes have no parent */ 911 912 /* 913 * Lock the dnode handle to prevent the dnode from obtaining any new 914 * holds. This also prevents the descendant dbufs and the bonus dbuf 915 * from accessing the dnode, so that we can discount their holds. The 916 * handle is safe to access because we know that while the dnode cannot 917 * go away, neither can its handle. Once we hold dnh_zrlock, we can 918 * safely move any dnode referenced only by dbufs. 919 */ 920 if (!zrl_tryenter(&odn->dn_handle->dnh_zrlock)) { 921 mutex_exit(&os->os_lock); 922 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_handle); 923 return (KMEM_CBRC_LATER); 924 } 925 926 /* 927 * Ensure a consistent view of the dnode's holds and the dnode's dbufs. 928 * We need to guarantee that there is a hold for every dbuf in order to 929 * determine whether the dnode is actively referenced. Falsely matching 930 * a dbuf to an active hold would lead to an unsafe move. It's possible 931 * that a thread already having an active dnode hold is about to add a 932 * dbuf, and we can't compare hold and dbuf counts while the add is in 933 * progress. 934 */ 935 if (!rw_tryenter(&odn->dn_struct_rwlock, RW_WRITER)) { 936 zrl_exit(&odn->dn_handle->dnh_zrlock); 937 mutex_exit(&os->os_lock); 938 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_rwlock); 939 return (KMEM_CBRC_LATER); 940 } 941 942 /* 943 * A dbuf may be removed (evicted) without an active dnode hold. In that 944 * case, the dbuf count is decremented under the handle lock before the 945 * dbuf's hold is released. This order ensures that if we count the hold 946 * after the dbuf is removed but before its hold is released, we will 947 * treat the unmatched hold as active and exit safely. If we count the 948 * hold before the dbuf is removed, the hold is discounted, and the 949 * removal is blocked until the move completes. 950 */ 951 refcount = refcount_count(&odn->dn_holds); 952 ASSERT(refcount >= 0); 953 dbufs = odn->dn_dbufs_count; 954 955 /* We can't have more dbufs than dnode holds. */ 956 ASSERT3U(dbufs, <=, refcount); 957 DTRACE_PROBE3(dnode__move, dnode_t *, odn, int64_t, refcount, 958 uint32_t, dbufs); 959 960 if (refcount > dbufs) { 961 rw_exit(&odn->dn_struct_rwlock); 962 zrl_exit(&odn->dn_handle->dnh_zrlock); 963 mutex_exit(&os->os_lock); 964 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_active); 965 return (KMEM_CBRC_LATER); 966 } 967 968 rw_exit(&odn->dn_struct_rwlock); 969 970 /* 971 * At this point we know that anyone with a hold on the dnode is not 972 * actively referencing it. The dnode is known and in a valid state to 973 * move. We're holding the locks needed to execute the critical section. 974 */ 975 dnode_move_impl(odn, ndn); 976 977 list_link_replace(&odn->dn_link, &ndn->dn_link); 978 /* If the dnode was safe to move, the refcount cannot have changed. */ 979 ASSERT(refcount == refcount_count(&ndn->dn_holds)); 980 ASSERT(dbufs == ndn->dn_dbufs_count); 981 zrl_exit(&ndn->dn_handle->dnh_zrlock); /* handle has moved */ 982 mutex_exit(&os->os_lock); 983 984 return (KMEM_CBRC_YES); 985} 986#endif /* _KERNEL */ 987#endif /* illumos */ 988 989void 990dnode_special_close(dnode_handle_t *dnh) 991{ 992 dnode_t *dn = dnh->dnh_dnode; 993 994 /* 995 * Wait for final references to the dnode to clear. This can 996 * only happen if the arc is asyncronously evicting state that 997 * has a hold on this dnode while we are trying to evict this 998 * dnode. 999 */ 1000 while (refcount_count(&dn->dn_holds) > 0) 1001 delay(1); 1002 ASSERT(dn->dn_dbuf == NULL || 1003 dmu_buf_get_user(&dn->dn_dbuf->db) == NULL); 1004 zrl_add(&dnh->dnh_zrlock); 1005 dnode_destroy(dn); /* implicit zrl_remove() */ 1006 zrl_destroy(&dnh->dnh_zrlock); 1007 dnh->dnh_dnode = NULL; 1008} 1009 1010void 1011dnode_special_open(objset_t *os, dnode_phys_t *dnp, uint64_t object, 1012 dnode_handle_t *dnh) 1013{ 1014 dnode_t *dn; 1015 1016 dn = dnode_create(os, dnp, NULL, object, dnh); 1017 zrl_init(&dnh->dnh_zrlock); 1018 DNODE_VERIFY(dn); 1019} 1020 1021static void 1022dnode_buf_pageout(void *dbu) 1023{ 1024 dnode_children_t *children_dnodes = dbu; 1025 int i; 1026 1027 for (i = 0; i < children_dnodes->dnc_count; i++) { 1028 dnode_handle_t *dnh = &children_dnodes->dnc_children[i]; 1029 dnode_t *dn; 1030 1031 /* 1032 * The dnode handle lock guards against the dnode moving to 1033 * another valid address, so there is no need here to guard 1034 * against changes to or from NULL. 1035 */ 1036 if (dnh->dnh_dnode == NULL) { 1037 zrl_destroy(&dnh->dnh_zrlock); 1038 continue; 1039 } 1040 1041 zrl_add(&dnh->dnh_zrlock); 1042 dn = dnh->dnh_dnode; 1043 /* 1044 * If there are holds on this dnode, then there should 1045 * be holds on the dnode's containing dbuf as well; thus 1046 * it wouldn't be eligible for eviction and this function 1047 * would not have been called. 1048 */ 1049 ASSERT(refcount_is_zero(&dn->dn_holds)); 1050 ASSERT(refcount_is_zero(&dn->dn_tx_holds)); 1051 1052 dnode_destroy(dn); /* implicit zrl_remove() */ 1053 zrl_destroy(&dnh->dnh_zrlock); 1054 dnh->dnh_dnode = NULL; 1055 } 1056 kmem_free(children_dnodes, sizeof (dnode_children_t) + 1057 children_dnodes->dnc_count * sizeof (dnode_handle_t)); 1058} 1059 1060/* 1061 * errors: 1062 * EINVAL - invalid object number. 1063 * EIO - i/o error. 1064 * succeeds even for free dnodes. 1065 */ 1066int 1067dnode_hold_impl(objset_t *os, uint64_t object, int flag, 1068 void *tag, dnode_t **dnp) 1069{ 1070 int epb, idx, err; 1071 int drop_struct_lock = FALSE; 1072 int type; 1073 uint64_t blk; 1074 dnode_t *mdn, *dn; 1075 dmu_buf_impl_t *db; 1076 dnode_children_t *children_dnodes; 1077 dnode_handle_t *dnh; 1078 1079 /* 1080 * If you are holding the spa config lock as writer, you shouldn't 1081 * be asking the DMU to do *anything* unless it's the root pool 1082 * which may require us to read from the root filesystem while 1083 * holding some (not all) of the locks as writer. 1084 */ 1085 ASSERT(spa_config_held(os->os_spa, SCL_ALL, RW_WRITER) == 0 || 1086 (spa_is_root(os->os_spa) && 1087 spa_config_held(os->os_spa, SCL_STATE, RW_WRITER))); 1088 1089 if (object == DMU_USERUSED_OBJECT || object == DMU_GROUPUSED_OBJECT) { 1090 dn = (object == DMU_USERUSED_OBJECT) ? 1091 DMU_USERUSED_DNODE(os) : DMU_GROUPUSED_DNODE(os); 1092 if (dn == NULL) 1093 return (SET_ERROR(ENOENT)); 1094 type = dn->dn_type; 1095 if ((flag & DNODE_MUST_BE_ALLOCATED) && type == DMU_OT_NONE) 1096 return (SET_ERROR(ENOENT)); 1097 if ((flag & DNODE_MUST_BE_FREE) && type != DMU_OT_NONE) 1098 return (SET_ERROR(EEXIST)); 1099 DNODE_VERIFY(dn); 1100 (void) refcount_add(&dn->dn_holds, tag); 1101 *dnp = dn; 1102 return (0); 1103 } 1104 1105 if (object == 0 || object >= DN_MAX_OBJECT) 1106 return (SET_ERROR(EINVAL)); 1107 1108 mdn = DMU_META_DNODE(os); 1109 ASSERT(mdn->dn_object == DMU_META_DNODE_OBJECT); 1110 1111 DNODE_VERIFY(mdn); 1112 1113 if (!RW_WRITE_HELD(&mdn->dn_struct_rwlock)) { 1114 rw_enter(&mdn->dn_struct_rwlock, RW_READER); 1115 drop_struct_lock = TRUE; 1116 } 1117 1118 blk = dbuf_whichblock(mdn, 0, object * sizeof (dnode_phys_t)); 1119 1120 db = dbuf_hold(mdn, blk, FTAG); 1121 if (drop_struct_lock) 1122 rw_exit(&mdn->dn_struct_rwlock); 1123 if (db == NULL) 1124 return (SET_ERROR(EIO)); 1125 err = dbuf_read(db, NULL, DB_RF_CANFAIL); 1126 if (err) { 1127 dbuf_rele(db, FTAG); 1128 return (err); 1129 } 1130 1131 ASSERT3U(db->db.db_size, >=, 1<<DNODE_SHIFT); 1132 epb = db->db.db_size >> DNODE_SHIFT; 1133 1134 idx = object & (epb-1); 1135 1136 ASSERT(DB_DNODE(db)->dn_type == DMU_OT_DNODE); 1137 children_dnodes = dmu_buf_get_user(&db->db); 1138 if (children_dnodes == NULL) { 1139 int i; 1140 dnode_children_t *winner; 1141 children_dnodes = kmem_zalloc(sizeof (dnode_children_t) + 1142 epb * sizeof (dnode_handle_t), KM_SLEEP); 1143 children_dnodes->dnc_count = epb; 1144 dnh = &children_dnodes->dnc_children[0]; 1145 for (i = 0; i < epb; i++) { 1146 zrl_init(&dnh[i].dnh_zrlock); 1147 } 1148 dmu_buf_init_user(&children_dnodes->dnc_dbu, 1149 dnode_buf_pageout, NULL); 1150 winner = dmu_buf_set_user(&db->db, &children_dnodes->dnc_dbu); 1151 if (winner != NULL) { 1152 1153 for (i = 0; i < epb; i++) { 1154 zrl_destroy(&dnh[i].dnh_zrlock); 1155 } 1156 1157 kmem_free(children_dnodes, sizeof (dnode_children_t) + 1158 epb * sizeof (dnode_handle_t)); 1159 children_dnodes = winner; 1160 } 1161 } 1162 ASSERT(children_dnodes->dnc_count == epb); 1163 1164 dnh = &children_dnodes->dnc_children[idx]; 1165 zrl_add(&dnh->dnh_zrlock); 1166 dn = dnh->dnh_dnode; 1167 if (dn == NULL) { 1168 dnode_phys_t *phys = (dnode_phys_t *)db->db.db_data+idx; 1169 1170 dn = dnode_create(os, phys, db, object, dnh); 1171 } 1172 1173 mutex_enter(&dn->dn_mtx); 1174 type = dn->dn_type; 1175 if (dn->dn_free_txg || 1176 ((flag & DNODE_MUST_BE_ALLOCATED) && type == DMU_OT_NONE) || 1177 ((flag & DNODE_MUST_BE_FREE) && 1178 (type != DMU_OT_NONE || !refcount_is_zero(&dn->dn_holds)))) { 1179 mutex_exit(&dn->dn_mtx); 1180 zrl_remove(&dnh->dnh_zrlock); 1181 dbuf_rele(db, FTAG); 1182 return (type == DMU_OT_NONE ? ENOENT : EEXIST); 1183 } 1184 if (refcount_add(&dn->dn_holds, tag) == 1) 1185 dbuf_add_ref(db, dnh); 1186 mutex_exit(&dn->dn_mtx); 1187 1188 /* Now we can rely on the hold to prevent the dnode from moving. */ 1189 zrl_remove(&dnh->dnh_zrlock); 1190 1191 DNODE_VERIFY(dn); 1192 ASSERT3P(dn->dn_dbuf, ==, db); 1193 ASSERT3U(dn->dn_object, ==, object); 1194 dbuf_rele(db, FTAG); 1195 1196 *dnp = dn; 1197 return (0); 1198} 1199 1200/* 1201 * Return held dnode if the object is allocated, NULL if not. 1202 */ 1203int 1204dnode_hold(objset_t *os, uint64_t object, void *tag, dnode_t **dnp) 1205{ 1206 return (dnode_hold_impl(os, object, DNODE_MUST_BE_ALLOCATED, tag, dnp)); 1207} 1208 1209/* 1210 * Can only add a reference if there is already at least one 1211 * reference on the dnode. Returns FALSE if unable to add a 1212 * new reference. 1213 */ 1214boolean_t 1215dnode_add_ref(dnode_t *dn, void *tag) 1216{ 1217 mutex_enter(&dn->dn_mtx); 1218 if (refcount_is_zero(&dn->dn_holds)) { 1219 mutex_exit(&dn->dn_mtx); 1220 return (FALSE); 1221 } 1222 VERIFY(1 < refcount_add(&dn->dn_holds, tag)); 1223 mutex_exit(&dn->dn_mtx); 1224 return (TRUE); 1225} 1226 1227void 1228dnode_rele(dnode_t *dn, void *tag) 1229{ 1230 mutex_enter(&dn->dn_mtx); 1231 dnode_rele_and_unlock(dn, tag); 1232} 1233 1234void 1235dnode_rele_and_unlock(dnode_t *dn, void *tag) 1236{ 1237 uint64_t refs; 1238 /* Get while the hold prevents the dnode from moving. */ 1239 dmu_buf_impl_t *db = dn->dn_dbuf; 1240 dnode_handle_t *dnh = dn->dn_handle; 1241 1242 refs = refcount_remove(&dn->dn_holds, tag); 1243 mutex_exit(&dn->dn_mtx); 1244 1245 /* 1246 * It's unsafe to release the last hold on a dnode by dnode_rele() or 1247 * indirectly by dbuf_rele() while relying on the dnode handle to 1248 * prevent the dnode from moving, since releasing the last hold could 1249 * result in the dnode's parent dbuf evicting its dnode handles. For 1250 * that reason anyone calling dnode_rele() or dbuf_rele() without some 1251 * other direct or indirect hold on the dnode must first drop the dnode 1252 * handle. 1253 */ 1254 ASSERT(refs > 0 || dnh->dnh_zrlock.zr_owner != curthread); 1255 1256 /* NOTE: the DNODE_DNODE does not have a dn_dbuf */ 1257 if (refs == 0 && db != NULL) { 1258 /* 1259 * Another thread could add a hold to the dnode handle in 1260 * dnode_hold_impl() while holding the parent dbuf. Since the 1261 * hold on the parent dbuf prevents the handle from being 1262 * destroyed, the hold on the handle is OK. We can't yet assert 1263 * that the handle has zero references, but that will be 1264 * asserted anyway when the handle gets destroyed. 1265 */ 1266 dbuf_rele(db, dnh); 1267 } 1268} 1269 1270void 1271dnode_setdirty(dnode_t *dn, dmu_tx_t *tx) 1272{ 1273 objset_t *os = dn->dn_objset; 1274 uint64_t txg = tx->tx_txg; 1275 1276 if (DMU_OBJECT_IS_SPECIAL(dn->dn_object)) { 1277 dsl_dataset_dirty(os->os_dsl_dataset, tx); 1278 return; 1279 } 1280 1281 DNODE_VERIFY(dn); 1282 1283#ifdef ZFS_DEBUG 1284 mutex_enter(&dn->dn_mtx); 1285 ASSERT(dn->dn_phys->dn_type || dn->dn_allocated_txg); 1286 ASSERT(dn->dn_free_txg == 0 || dn->dn_free_txg >= txg); 1287 mutex_exit(&dn->dn_mtx); 1288#endif 1289 1290 /* 1291 * Determine old uid/gid when necessary 1292 */ 1293 dmu_objset_userquota_get_ids(dn, B_TRUE, tx); 1294 1295 mutex_enter(&os->os_lock); 1296 1297 /* 1298 * If we are already marked dirty, we're done. 1299 */ 1300 if (list_link_active(&dn->dn_dirty_link[txg & TXG_MASK])) { 1301 mutex_exit(&os->os_lock); 1302 return; 1303 } 1304 1305 ASSERT(!refcount_is_zero(&dn->dn_holds) || 1306 !avl_is_empty(&dn->dn_dbufs)); 1307 ASSERT(dn->dn_datablksz != 0); 1308 ASSERT0(dn->dn_next_bonuslen[txg&TXG_MASK]); 1309 ASSERT0(dn->dn_next_blksz[txg&TXG_MASK]); 1310 ASSERT0(dn->dn_next_bonustype[txg&TXG_MASK]); 1311 1312 dprintf_ds(os->os_dsl_dataset, "obj=%llu txg=%llu\n", 1313 dn->dn_object, txg); 1314 1315 if (dn->dn_free_txg > 0 && dn->dn_free_txg <= txg) { 1316 list_insert_tail(&os->os_free_dnodes[txg&TXG_MASK], dn); 1317 } else { 1318 list_insert_tail(&os->os_dirty_dnodes[txg&TXG_MASK], dn); 1319 } 1320 1321 mutex_exit(&os->os_lock); 1322 1323 /* 1324 * The dnode maintains a hold on its containing dbuf as 1325 * long as there are holds on it. Each instantiated child 1326 * dbuf maintains a hold on the dnode. When the last child 1327 * drops its hold, the dnode will drop its hold on the 1328 * containing dbuf. We add a "dirty hold" here so that the 1329 * dnode will hang around after we finish processing its 1330 * children. 1331 */ 1332 VERIFY(dnode_add_ref(dn, (void *)(uintptr_t)tx->tx_txg)); 1333 1334 (void) dbuf_dirty(dn->dn_dbuf, tx); 1335 1336 dsl_dataset_dirty(os->os_dsl_dataset, tx); 1337} 1338 1339void 1340dnode_free(dnode_t *dn, dmu_tx_t *tx) 1341{ 1342 int txgoff = tx->tx_txg & TXG_MASK; 1343 1344 dprintf("dn=%p txg=%llu\n", dn, tx->tx_txg); 1345 1346 /* we should be the only holder... hopefully */ 1347 /* ASSERT3U(refcount_count(&dn->dn_holds), ==, 1); */ 1348 1349 mutex_enter(&dn->dn_mtx); 1350 if (dn->dn_type == DMU_OT_NONE || dn->dn_free_txg) { 1351 mutex_exit(&dn->dn_mtx); 1352 return; 1353 } 1354 dn->dn_free_txg = tx->tx_txg; 1355 mutex_exit(&dn->dn_mtx); 1356 1357 /* 1358 * If the dnode is already dirty, it needs to be moved from 1359 * the dirty list to the free list. 1360 */ 1361 mutex_enter(&dn->dn_objset->os_lock); 1362 if (list_link_active(&dn->dn_dirty_link[txgoff])) { 1363 list_remove(&dn->dn_objset->os_dirty_dnodes[txgoff], dn); 1364 list_insert_tail(&dn->dn_objset->os_free_dnodes[txgoff], dn); 1365 mutex_exit(&dn->dn_objset->os_lock); 1366 } else { 1367 mutex_exit(&dn->dn_objset->os_lock); 1368 dnode_setdirty(dn, tx); 1369 } 1370} 1371 1372/* 1373 * Try to change the block size for the indicated dnode. This can only 1374 * succeed if there are no blocks allocated or dirty beyond first block 1375 */ 1376int 1377dnode_set_blksz(dnode_t *dn, uint64_t size, int ibs, dmu_tx_t *tx) 1378{ 1379 dmu_buf_impl_t *db; 1380 int err; 1381 1382 ASSERT3U(size, <=, spa_maxblocksize(dmu_objset_spa(dn->dn_objset))); 1383 if (size == 0) 1384 size = SPA_MINBLOCKSIZE; 1385 else 1386 size = P2ROUNDUP(size, SPA_MINBLOCKSIZE); 1387 1388 if (ibs == dn->dn_indblkshift) 1389 ibs = 0; 1390 1391 if (size >> SPA_MINBLOCKSHIFT == dn->dn_datablkszsec && ibs == 0) 1392 return (0); 1393 1394 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 1395 1396 /* Check for any allocated blocks beyond the first */ 1397 if (dn->dn_maxblkid != 0) 1398 goto fail; 1399 1400 mutex_enter(&dn->dn_dbufs_mtx); 1401 for (db = avl_first(&dn->dn_dbufs); db != NULL; 1402 db = AVL_NEXT(&dn->dn_dbufs, db)) { 1403 if (db->db_blkid != 0 && db->db_blkid != DMU_BONUS_BLKID && 1404 db->db_blkid != DMU_SPILL_BLKID) { 1405 mutex_exit(&dn->dn_dbufs_mtx); 1406 goto fail; 1407 } 1408 } 1409 mutex_exit(&dn->dn_dbufs_mtx); 1410 1411 if (ibs && dn->dn_nlevels != 1) 1412 goto fail; 1413 1414 /* resize the old block */ 1415 err = dbuf_hold_impl(dn, 0, 0, TRUE, FALSE, FTAG, &db); 1416 if (err == 0) 1417 dbuf_new_size(db, size, tx); 1418 else if (err != ENOENT) 1419 goto fail; 1420 1421 dnode_setdblksz(dn, size); 1422 dnode_setdirty(dn, tx); 1423 dn->dn_next_blksz[tx->tx_txg&TXG_MASK] = size; 1424 if (ibs) { 1425 dn->dn_indblkshift = ibs; 1426 dn->dn_next_indblkshift[tx->tx_txg&TXG_MASK] = ibs; 1427 } 1428 /* rele after we have fixed the blocksize in the dnode */ 1429 if (db) 1430 dbuf_rele(db, FTAG); 1431 1432 rw_exit(&dn->dn_struct_rwlock); 1433 return (0); 1434 1435fail: 1436 rw_exit(&dn->dn_struct_rwlock); 1437 return (SET_ERROR(ENOTSUP)); 1438} 1439 1440/* read-holding callers must not rely on the lock being continuously held */ 1441void 1442dnode_new_blkid(dnode_t *dn, uint64_t blkid, dmu_tx_t *tx, boolean_t have_read) 1443{ 1444 uint64_t txgoff = tx->tx_txg & TXG_MASK; 1445 int epbs, new_nlevels; 1446 uint64_t sz; 1447 1448 ASSERT(blkid != DMU_BONUS_BLKID); 1449 1450 ASSERT(have_read ? 1451 RW_READ_HELD(&dn->dn_struct_rwlock) : 1452 RW_WRITE_HELD(&dn->dn_struct_rwlock)); 1453 1454 /* 1455 * if we have a read-lock, check to see if we need to do any work 1456 * before upgrading to a write-lock. 1457 */ 1458 if (have_read) { 1459 if (blkid <= dn->dn_maxblkid) 1460 return; 1461 1462 if (!rw_tryupgrade(&dn->dn_struct_rwlock)) { 1463 rw_exit(&dn->dn_struct_rwlock); 1464 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 1465 } 1466 } 1467 1468 if (blkid <= dn->dn_maxblkid) 1469 goto out; 1470 1471 dn->dn_maxblkid = blkid; 1472 1473 /* 1474 * Compute the number of levels necessary to support the new maxblkid. 1475 */ 1476 new_nlevels = 1; 1477 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT; 1478 for (sz = dn->dn_nblkptr; 1479 sz <= blkid && sz >= dn->dn_nblkptr; sz <<= epbs) 1480 new_nlevels++; 1481 1482 if (new_nlevels > dn->dn_nlevels) { 1483 int old_nlevels = dn->dn_nlevels; 1484 dmu_buf_impl_t *db; 1485 list_t *list; 1486 dbuf_dirty_record_t *new, *dr, *dr_next; 1487 1488 dn->dn_nlevels = new_nlevels; 1489 1490 ASSERT3U(new_nlevels, >, dn->dn_next_nlevels[txgoff]); 1491 dn->dn_next_nlevels[txgoff] = new_nlevels; 1492 1493 /* dirty the left indirects */ 1494 db = dbuf_hold_level(dn, old_nlevels, 0, FTAG); 1495 ASSERT(db != NULL); 1496 new = dbuf_dirty(db, tx); 1497 dbuf_rele(db, FTAG); 1498 1499 /* transfer the dirty records to the new indirect */ 1500 mutex_enter(&dn->dn_mtx); 1501 mutex_enter(&new->dt.di.dr_mtx); 1502 list = &dn->dn_dirty_records[txgoff]; 1503 for (dr = list_head(list); dr; dr = dr_next) { 1504 dr_next = list_next(&dn->dn_dirty_records[txgoff], dr); 1505 if (dr->dr_dbuf->db_level != new_nlevels-1 && 1506 dr->dr_dbuf->db_blkid != DMU_BONUS_BLKID && 1507 dr->dr_dbuf->db_blkid != DMU_SPILL_BLKID) { 1508 ASSERT(dr->dr_dbuf->db_level == old_nlevels-1); 1509 list_remove(&dn->dn_dirty_records[txgoff], dr); 1510 list_insert_tail(&new->dt.di.dr_children, dr); 1511 dr->dr_parent = new; 1512 } 1513 } 1514 mutex_exit(&new->dt.di.dr_mtx); 1515 mutex_exit(&dn->dn_mtx); 1516 } 1517 1518out: 1519 if (have_read) 1520 rw_downgrade(&dn->dn_struct_rwlock); 1521} 1522 1523static void 1524dnode_dirty_l1(dnode_t *dn, uint64_t l1blkid, dmu_tx_t *tx) 1525{ 1526 dmu_buf_impl_t *db = dbuf_hold_level(dn, 1, l1blkid, FTAG); 1527 if (db != NULL) { 1528 dmu_buf_will_dirty(&db->db, tx); 1529 dbuf_rele(db, FTAG); 1530 } 1531} 1532 1533void 1534dnode_free_range(dnode_t *dn, uint64_t off, uint64_t len, dmu_tx_t *tx) 1535{ 1536 dmu_buf_impl_t *db; 1537 uint64_t blkoff, blkid, nblks; 1538 int blksz, blkshift, head, tail; 1539 int trunc = FALSE; 1540 int epbs; 1541 1542 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 1543 blksz = dn->dn_datablksz; 1544 blkshift = dn->dn_datablkshift; 1545 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT; 1546 1547 if (len == DMU_OBJECT_END) { 1548 len = UINT64_MAX - off; 1549 trunc = TRUE; 1550 } 1551 1552 /* 1553 * First, block align the region to free: 1554 */ 1555 if (ISP2(blksz)) { 1556 head = P2NPHASE(off, blksz); 1557 blkoff = P2PHASE(off, blksz); 1558 if ((off >> blkshift) > dn->dn_maxblkid) 1559 goto out; 1560 } else { 1561 ASSERT(dn->dn_maxblkid == 0); 1562 if (off == 0 && len >= blksz) { 1563 /* 1564 * Freeing the whole block; fast-track this request. 1565 * Note that we won't dirty any indirect blocks, 1566 * which is fine because we will be freeing the entire 1567 * file and thus all indirect blocks will be freed 1568 * by free_children(). 1569 */ 1570 blkid = 0; 1571 nblks = 1; 1572 goto done; 1573 } else if (off >= blksz) { 1574 /* Freeing past end-of-data */ 1575 goto out; 1576 } else { 1577 /* Freeing part of the block. */ 1578 head = blksz - off; 1579 ASSERT3U(head, >, 0); 1580 } 1581 blkoff = off; 1582 } 1583 /* zero out any partial block data at the start of the range */ 1584 if (head) { 1585 ASSERT3U(blkoff + head, ==, blksz); 1586 if (len < head) 1587 head = len; 1588 if (dbuf_hold_impl(dn, 0, dbuf_whichblock(dn, 0, off), 1589 TRUE, FALSE, FTAG, &db) == 0) { 1590 caddr_t data; 1591 1592 /* don't dirty if it isn't on disk and isn't dirty */ 1593 if (db->db_last_dirty || 1594 (db->db_blkptr && !BP_IS_HOLE(db->db_blkptr))) { 1595 rw_exit(&dn->dn_struct_rwlock); 1596 dmu_buf_will_dirty(&db->db, tx); 1597 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 1598 data = db->db.db_data; 1599 bzero(data + blkoff, head); 1600 } 1601 dbuf_rele(db, FTAG); 1602 } 1603 off += head; 1604 len -= head; 1605 } 1606 1607 /* If the range was less than one block, we're done */ 1608 if (len == 0) 1609 goto out; 1610 1611 /* If the remaining range is past end of file, we're done */ 1612 if ((off >> blkshift) > dn->dn_maxblkid) 1613 goto out; 1614 1615 ASSERT(ISP2(blksz)); 1616 if (trunc) 1617 tail = 0; 1618 else 1619 tail = P2PHASE(len, blksz); 1620 1621 ASSERT0(P2PHASE(off, blksz)); 1622 /* zero out any partial block data at the end of the range */ 1623 if (tail) { 1624 if (len < tail) 1625 tail = len; 1626 if (dbuf_hold_impl(dn, 0, dbuf_whichblock(dn, 0, off+len), 1627 TRUE, FALSE, FTAG, &db) == 0) { 1628 /* don't dirty if not on disk and not dirty */ 1629 if (db->db_last_dirty || 1630 (db->db_blkptr && !BP_IS_HOLE(db->db_blkptr))) { 1631 rw_exit(&dn->dn_struct_rwlock); 1632 dmu_buf_will_dirty(&db->db, tx); 1633 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 1634 bzero(db->db.db_data, tail); 1635 } 1636 dbuf_rele(db, FTAG); 1637 } 1638 len -= tail; 1639 } 1640 1641 /* If the range did not include a full block, we are done */ 1642 if (len == 0) 1643 goto out; 1644 1645 ASSERT(IS_P2ALIGNED(off, blksz)); 1646 ASSERT(trunc || IS_P2ALIGNED(len, blksz)); 1647 blkid = off >> blkshift; 1648 nblks = len >> blkshift; 1649 if (trunc) 1650 nblks += 1; 1651 1652 /* 1653 * Dirty all the indirect blocks in this range. Note that only 1654 * the first and last indirect blocks can actually be written 1655 * (if they were partially freed) -- they must be dirtied, even if 1656 * they do not exist on disk yet. The interior blocks will 1657 * be freed by free_children(), so they will not actually be written. 1658 * Even though these interior blocks will not be written, we 1659 * dirty them for two reasons: 1660 * 1661 * - It ensures that the indirect blocks remain in memory until 1662 * syncing context. (They have already been prefetched by 1663 * dmu_tx_hold_free(), so we don't have to worry about reading 1664 * them serially here.) 1665 * 1666 * - The dirty space accounting will put pressure on the txg sync 1667 * mechanism to begin syncing, and to delay transactions if there 1668 * is a large amount of freeing. Even though these indirect 1669 * blocks will not be written, we could need to write the same 1670 * amount of space if we copy the freed BPs into deadlists. 1671 */ 1672 if (dn->dn_nlevels > 1) { 1673 uint64_t first, last; 1674 1675 first = blkid >> epbs; 1676 dnode_dirty_l1(dn, first, tx); 1677 if (trunc) 1678 last = dn->dn_maxblkid >> epbs; 1679 else 1680 last = (blkid + nblks - 1) >> epbs; 1681 if (last != first) 1682 dnode_dirty_l1(dn, last, tx); 1683 1684 int shift = dn->dn_datablkshift + dn->dn_indblkshift - 1685 SPA_BLKPTRSHIFT; 1686 for (uint64_t i = first + 1; i < last; i++) { 1687 /* 1688 * Set i to the blockid of the next non-hole 1689 * level-1 indirect block at or after i. Note 1690 * that dnode_next_offset() operates in terms of 1691 * level-0-equivalent bytes. 1692 */ 1693 uint64_t ibyte = i << shift; 1694 int err = dnode_next_offset(dn, DNODE_FIND_HAVELOCK, 1695 &ibyte, 2, 1, 0); 1696 i = ibyte >> shift; 1697 if (i >= last) 1698 break; 1699 1700 /* 1701 * Normally we should not see an error, either 1702 * from dnode_next_offset() or dbuf_hold_level() 1703 * (except for ESRCH from dnode_next_offset). 1704 * If there is an i/o error, then when we read 1705 * this block in syncing context, it will use 1706 * ZIO_FLAG_MUSTSUCCEED, and thus hang/panic according 1707 * to the "failmode" property. dnode_next_offset() 1708 * doesn't have a flag to indicate MUSTSUCCEED. 1709 */ 1710 if (err != 0) 1711 break; 1712 1713 dnode_dirty_l1(dn, i, tx); 1714 } 1715 } 1716 1717done: 1718 /* 1719 * Add this range to the dnode range list. 1720 * We will finish up this free operation in the syncing phase. 1721 */ 1722 mutex_enter(&dn->dn_mtx); 1723 int txgoff = tx->tx_txg & TXG_MASK; 1724 if (dn->dn_free_ranges[txgoff] == NULL) { 1725 dn->dn_free_ranges[txgoff] = 1726 range_tree_create(NULL, NULL, &dn->dn_mtx); 1727 } 1728 range_tree_clear(dn->dn_free_ranges[txgoff], blkid, nblks); 1729 range_tree_add(dn->dn_free_ranges[txgoff], blkid, nblks); 1730 dprintf_dnode(dn, "blkid=%llu nblks=%llu txg=%llu\n", 1731 blkid, nblks, tx->tx_txg); 1732 mutex_exit(&dn->dn_mtx); 1733 1734 dbuf_free_range(dn, blkid, blkid + nblks - 1, tx); 1735 dnode_setdirty(dn, tx); 1736out: 1737 1738 rw_exit(&dn->dn_struct_rwlock); 1739} 1740 1741static boolean_t 1742dnode_spill_freed(dnode_t *dn) 1743{ 1744 int i; 1745 1746 mutex_enter(&dn->dn_mtx); 1747 for (i = 0; i < TXG_SIZE; i++) { 1748 if (dn->dn_rm_spillblk[i] == DN_KILL_SPILLBLK) 1749 break; 1750 } 1751 mutex_exit(&dn->dn_mtx); 1752 return (i < TXG_SIZE); 1753} 1754 1755/* return TRUE if this blkid was freed in a recent txg, or FALSE if it wasn't */ 1756uint64_t 1757dnode_block_freed(dnode_t *dn, uint64_t blkid) 1758{ 1759 void *dp = spa_get_dsl(dn->dn_objset->os_spa); 1760 int i; 1761 1762 if (blkid == DMU_BONUS_BLKID) 1763 return (FALSE); 1764 1765 /* 1766 * If we're in the process of opening the pool, dp will not be 1767 * set yet, but there shouldn't be anything dirty. 1768 */ 1769 if (dp == NULL) 1770 return (FALSE); 1771 1772 if (dn->dn_free_txg) 1773 return (TRUE); 1774 1775 if (blkid == DMU_SPILL_BLKID) 1776 return (dnode_spill_freed(dn)); 1777 1778 mutex_enter(&dn->dn_mtx); 1779 for (i = 0; i < TXG_SIZE; i++) { 1780 if (dn->dn_free_ranges[i] != NULL && 1781 range_tree_contains(dn->dn_free_ranges[i], blkid, 1)) 1782 break; 1783 } 1784 mutex_exit(&dn->dn_mtx); 1785 return (i < TXG_SIZE); 1786} 1787 1788/* call from syncing context when we actually write/free space for this dnode */ 1789void 1790dnode_diduse_space(dnode_t *dn, int64_t delta) 1791{ 1792 uint64_t space; 1793 dprintf_dnode(dn, "dn=%p dnp=%p used=%llu delta=%lld\n", 1794 dn, dn->dn_phys, 1795 (u_longlong_t)dn->dn_phys->dn_used, 1796 (longlong_t)delta); 1797 1798 mutex_enter(&dn->dn_mtx); 1799 space = DN_USED_BYTES(dn->dn_phys); 1800 if (delta > 0) { 1801 ASSERT3U(space + delta, >=, space); /* no overflow */ 1802 } else { 1803 ASSERT3U(space, >=, -delta); /* no underflow */ 1804 } 1805 space += delta; 1806 if (spa_version(dn->dn_objset->os_spa) < SPA_VERSION_DNODE_BYTES) { 1807 ASSERT((dn->dn_phys->dn_flags & DNODE_FLAG_USED_BYTES) == 0); 1808 ASSERT0(P2PHASE(space, 1<<DEV_BSHIFT)); 1809 dn->dn_phys->dn_used = space >> DEV_BSHIFT; 1810 } else { 1811 dn->dn_phys->dn_used = space; 1812 dn->dn_phys->dn_flags |= DNODE_FLAG_USED_BYTES; 1813 } 1814 mutex_exit(&dn->dn_mtx); 1815} 1816 1817/* 1818 * Call when we think we're going to write/free space in open context to track 1819 * the amount of memory in use by the currently open txg. 1820 */ 1821void 1822dnode_willuse_space(dnode_t *dn, int64_t space, dmu_tx_t *tx) 1823{ 1824 objset_t *os = dn->dn_objset; 1825 dsl_dataset_t *ds = os->os_dsl_dataset; 1826 int64_t aspace = spa_get_asize(os->os_spa, space); 1827 1828 if (ds != NULL) { 1829 dsl_dir_willuse_space(ds->ds_dir, aspace, tx); 1830 dsl_pool_dirty_space(dmu_tx_pool(tx), space, tx); 1831 } 1832 1833 dmu_tx_willuse_space(tx, aspace); 1834} 1835 1836/* 1837 * Scans a block at the indicated "level" looking for a hole or data, 1838 * depending on 'flags'. 1839 * 1840 * If level > 0, then we are scanning an indirect block looking at its 1841 * pointers. If level == 0, then we are looking at a block of dnodes. 1842 * 1843 * If we don't find what we are looking for in the block, we return ESRCH. 1844 * Otherwise, return with *offset pointing to the beginning (if searching 1845 * forwards) or end (if searching backwards) of the range covered by the 1846 * block pointer we matched on (or dnode). 1847 * 1848 * The basic search algorithm used below by dnode_next_offset() is to 1849 * use this function to search up the block tree (widen the search) until 1850 * we find something (i.e., we don't return ESRCH) and then search back 1851 * down the tree (narrow the search) until we reach our original search 1852 * level. 1853 */ 1854static int 1855dnode_next_offset_level(dnode_t *dn, int flags, uint64_t *offset, 1856 int lvl, uint64_t blkfill, uint64_t txg) 1857{ 1858 dmu_buf_impl_t *db = NULL; 1859 void *data = NULL; 1860 uint64_t epbs = dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT; 1861 uint64_t epb = 1ULL << epbs; 1862 uint64_t minfill, maxfill; 1863 boolean_t hole; 1864 int i, inc, error, span; 1865 1866 dprintf("probing object %llu offset %llx level %d of %u\n", 1867 dn->dn_object, *offset, lvl, dn->dn_phys->dn_nlevels); 1868 1869 hole = ((flags & DNODE_FIND_HOLE) != 0); 1870 inc = (flags & DNODE_FIND_BACKWARDS) ? -1 : 1; 1871 ASSERT(txg == 0 || !hole); 1872 1873 if (lvl == dn->dn_phys->dn_nlevels) { 1874 error = 0; 1875 epb = dn->dn_phys->dn_nblkptr; 1876 data = dn->dn_phys->dn_blkptr; 1877 } else { 1878 uint64_t blkid = dbuf_whichblock(dn, lvl, *offset); 1879 error = dbuf_hold_impl(dn, lvl, blkid, TRUE, FALSE, FTAG, &db); 1880 if (error) { 1881 if (error != ENOENT) 1882 return (error); 1883 if (hole) 1884 return (0); 1885 /* 1886 * This can only happen when we are searching up 1887 * the block tree for data. We don't really need to 1888 * adjust the offset, as we will just end up looking 1889 * at the pointer to this block in its parent, and its 1890 * going to be unallocated, so we will skip over it. 1891 */ 1892 return (SET_ERROR(ESRCH)); 1893 } 1894 error = dbuf_read(db, NULL, DB_RF_CANFAIL | DB_RF_HAVESTRUCT); 1895 if (error) { 1896 dbuf_rele(db, FTAG); 1897 return (error); 1898 } 1899 data = db->db.db_data; 1900 } 1901 1902 1903 if (db != NULL && txg != 0 && (db->db_blkptr == NULL || 1904 db->db_blkptr->blk_birth <= txg || 1905 BP_IS_HOLE(db->db_blkptr))) { 1906 /* 1907 * This can only happen when we are searching up the tree 1908 * and these conditions mean that we need to keep climbing. 1909 */ 1910 error = SET_ERROR(ESRCH); 1911 } else if (lvl == 0) { 1912 dnode_phys_t *dnp = data; 1913 span = DNODE_SHIFT; 1914 ASSERT(dn->dn_type == DMU_OT_DNODE); 1915 1916 for (i = (*offset >> span) & (blkfill - 1); 1917 i >= 0 && i < blkfill; i += inc) { 1918 if ((dnp[i].dn_type == DMU_OT_NONE) == hole) 1919 break; 1920 *offset += (1ULL << span) * inc; 1921 } 1922 if (i < 0 || i == blkfill) 1923 error = SET_ERROR(ESRCH); 1924 } else { 1925 blkptr_t *bp = data; 1926 uint64_t start = *offset; 1927 span = (lvl - 1) * epbs + dn->dn_datablkshift; 1928 minfill = 0; 1929 maxfill = blkfill << ((lvl - 1) * epbs); 1930 1931 if (hole) 1932 maxfill--; 1933 else 1934 minfill++; 1935 1936 *offset = *offset >> span; 1937 for (i = BF64_GET(*offset, 0, epbs); 1938 i >= 0 && i < epb; i += inc) { 1939 if (BP_GET_FILL(&bp[i]) >= minfill && 1940 BP_GET_FILL(&bp[i]) <= maxfill && 1941 (hole || bp[i].blk_birth > txg)) 1942 break; 1943 if (inc > 0 || *offset > 0) 1944 *offset += inc; 1945 } 1946 *offset = *offset << span; 1947 if (inc < 0) { 1948 /* traversing backwards; position offset at the end */ 1949 ASSERT3U(*offset, <=, start); 1950 *offset = MIN(*offset + (1ULL << span) - 1, start); 1951 } else if (*offset < start) { 1952 *offset = start; 1953 } 1954 if (i < 0 || i >= epb) 1955 error = SET_ERROR(ESRCH); 1956 } 1957 1958 if (db) 1959 dbuf_rele(db, FTAG); 1960 1961 return (error); 1962} 1963 1964/* 1965 * Find the next hole, data, or sparse region at or after *offset. 1966 * The value 'blkfill' tells us how many items we expect to find 1967 * in an L0 data block; this value is 1 for normal objects, 1968 * DNODES_PER_BLOCK for the meta dnode, and some fraction of 1969 * DNODES_PER_BLOCK when searching for sparse regions thereof. 1970 * 1971 * Examples: 1972 * 1973 * dnode_next_offset(dn, flags, offset, 1, 1, 0); 1974 * Finds the next/previous hole/data in a file. 1975 * Used in dmu_offset_next(). 1976 * 1977 * dnode_next_offset(mdn, flags, offset, 0, DNODES_PER_BLOCK, txg); 1978 * Finds the next free/allocated dnode an objset's meta-dnode. 1979 * Only finds objects that have new contents since txg (ie. 1980 * bonus buffer changes and content removal are ignored). 1981 * Used in dmu_object_next(). 1982 * 1983 * dnode_next_offset(mdn, DNODE_FIND_HOLE, offset, 2, DNODES_PER_BLOCK >> 2, 0); 1984 * Finds the next L2 meta-dnode bp that's at most 1/4 full. 1985 * Used in dmu_object_alloc(). 1986 */ 1987int 1988dnode_next_offset(dnode_t *dn, int flags, uint64_t *offset, 1989 int minlvl, uint64_t blkfill, uint64_t txg) 1990{ 1991 uint64_t initial_offset = *offset; 1992 int lvl, maxlvl; 1993 int error = 0; 1994 1995 if (!(flags & DNODE_FIND_HAVELOCK)) 1996 rw_enter(&dn->dn_struct_rwlock, RW_READER); 1997 1998 if (dn->dn_phys->dn_nlevels == 0) { 1999 error = SET_ERROR(ESRCH); 2000 goto out; 2001 } 2002 2003 if (dn->dn_datablkshift == 0) { 2004 if (*offset < dn->dn_datablksz) { 2005 if (flags & DNODE_FIND_HOLE) 2006 *offset = dn->dn_datablksz; 2007 } else { 2008 error = SET_ERROR(ESRCH); 2009 } 2010 goto out; 2011 } 2012 2013 maxlvl = dn->dn_phys->dn_nlevels; 2014 2015 for (lvl = minlvl; lvl <= maxlvl; lvl++) { 2016 error = dnode_next_offset_level(dn, 2017 flags, offset, lvl, blkfill, txg); 2018 if (error != ESRCH) 2019 break; 2020 } 2021 2022 while (error == 0 && --lvl >= minlvl) { 2023 error = dnode_next_offset_level(dn, 2024 flags, offset, lvl, blkfill, txg); 2025 } 2026 2027 /* 2028 * There's always a "virtual hole" at the end of the object, even 2029 * if all BP's which physically exist are non-holes. 2030 */ 2031 if ((flags & DNODE_FIND_HOLE) && error == ESRCH && txg == 0 && 2032 minlvl == 1 && blkfill == 1 && !(flags & DNODE_FIND_BACKWARDS)) { 2033 error = 0; 2034 } 2035 2036 if (error == 0 && (flags & DNODE_FIND_BACKWARDS ? 2037 initial_offset < *offset : initial_offset > *offset)) 2038 error = SET_ERROR(ESRCH); 2039out: 2040 if (!(flags & DNODE_FIND_HAVELOCK)) 2041 rw_exit(&dn->dn_struct_rwlock); 2042 2043 return (error); 2044} 2045