dnode.c revision 297077
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 */ 26 27#include <sys/zfs_context.h> 28#include <sys/dbuf.h> 29#include <sys/dnode.h> 30#include <sys/dmu.h> 31#include <sys/dmu_impl.h> 32#include <sys/dmu_tx.h> 33#include <sys/dmu_objset.h> 34#include <sys/dsl_dir.h> 35#include <sys/dsl_dataset.h> 36#include <sys/spa.h> 37#include <sys/zio.h> 38#include <sys/dmu_zfetch.h> 39#include <sys/range_tree.h> 40 41static kmem_cache_t *dnode_cache; 42/* 43 * Define DNODE_STATS to turn on statistic gathering. By default, it is only 44 * turned on when DEBUG is also defined. 45 */ 46#ifdef DEBUG 47#define DNODE_STATS 48#endif /* DEBUG */ 49 50#ifdef DNODE_STATS 51#define DNODE_STAT_ADD(stat) ((stat)++) 52#else 53#define DNODE_STAT_ADD(stat) /* nothing */ 54#endif /* DNODE_STATS */ 55 56static dnode_phys_t dnode_phys_zero; 57 58int zfs_default_bs = SPA_MINBLOCKSHIFT; 59int zfs_default_ibs = DN_MAX_INDBLKSHIFT; 60 61#ifdef illumos 62static kmem_cbrc_t dnode_move(void *, void *, size_t, void *); 63#endif 64 65static int 66dbuf_compare(const void *x1, const void *x2) 67{ 68 const dmu_buf_impl_t *d1 = x1; 69 const dmu_buf_impl_t *d2 = x2; 70 71 if (d1->db_level < d2->db_level) { 72 return (-1); 73 } 74 if (d1->db_level > d2->db_level) { 75 return (1); 76 } 77 78 if (d1->db_blkid < d2->db_blkid) { 79 return (-1); 80 } 81 if (d1->db_blkid > d2->db_blkid) { 82 return (1); 83 } 84 85 if (d1->db_state == DB_SEARCH) { 86 ASSERT3S(d2->db_state, !=, DB_SEARCH); 87 return (-1); 88 } else if (d2->db_state == DB_SEARCH) { 89 ASSERT3S(d1->db_state, !=, DB_SEARCH); 90 return (1); 91 } 92 93 if ((uintptr_t)d1 < (uintptr_t)d2) { 94 return (-1); 95 } 96 if ((uintptr_t)d1 > (uintptr_t)d2) { 97 return (1); 98 } 99 return (0); 100} 101 102/* ARGSUSED */ 103static int 104dnode_cons(void *arg, void *unused, int kmflag) 105{ 106 dnode_t *dn = arg; 107 int i; 108 109 rw_init(&dn->dn_struct_rwlock, NULL, RW_DEFAULT, NULL); 110 mutex_init(&dn->dn_mtx, NULL, MUTEX_DEFAULT, NULL); 111 mutex_init(&dn->dn_dbufs_mtx, NULL, MUTEX_DEFAULT, NULL); 112 cv_init(&dn->dn_notxholds, NULL, CV_DEFAULT, NULL); 113 114 /* 115 * Every dbuf has a reference, and dropping a tracked reference is 116 * O(number of references), so don't track dn_holds. 117 */ 118 refcount_create_untracked(&dn->dn_holds); 119 refcount_create(&dn->dn_tx_holds); 120 list_link_init(&dn->dn_link); 121 122 bzero(&dn->dn_next_nblkptr[0], sizeof (dn->dn_next_nblkptr)); 123 bzero(&dn->dn_next_nlevels[0], sizeof (dn->dn_next_nlevels)); 124 bzero(&dn->dn_next_indblkshift[0], sizeof (dn->dn_next_indblkshift)); 125 bzero(&dn->dn_next_bonustype[0], sizeof (dn->dn_next_bonustype)); 126 bzero(&dn->dn_rm_spillblk[0], sizeof (dn->dn_rm_spillblk)); 127 bzero(&dn->dn_next_bonuslen[0], sizeof (dn->dn_next_bonuslen)); 128 bzero(&dn->dn_next_blksz[0], sizeof (dn->dn_next_blksz)); 129 130 for (i = 0; i < TXG_SIZE; i++) { 131 list_link_init(&dn->dn_dirty_link[i]); 132 dn->dn_free_ranges[i] = NULL; 133 list_create(&dn->dn_dirty_records[i], 134 sizeof (dbuf_dirty_record_t), 135 offsetof(dbuf_dirty_record_t, dr_dirty_node)); 136 } 137 138 dn->dn_allocated_txg = 0; 139 dn->dn_free_txg = 0; 140 dn->dn_assigned_txg = 0; 141 dn->dn_dirtyctx = 0; 142 dn->dn_dirtyctx_firstset = NULL; 143 dn->dn_bonus = NULL; 144 dn->dn_have_spill = B_FALSE; 145 dn->dn_zio = NULL; 146 dn->dn_oldused = 0; 147 dn->dn_oldflags = 0; 148 dn->dn_olduid = 0; 149 dn->dn_oldgid = 0; 150 dn->dn_newuid = 0; 151 dn->dn_newgid = 0; 152 dn->dn_id_flags = 0; 153 154 dn->dn_dbufs_count = 0; 155 dn->dn_unlisted_l0_blkid = 0; 156 avl_create(&dn->dn_dbufs, dbuf_compare, sizeof (dmu_buf_impl_t), 157 offsetof(dmu_buf_impl_t, db_link)); 158 159 dn->dn_moved = 0; 160 POINTER_INVALIDATE(&dn->dn_objset); 161 return (0); 162} 163 164/* ARGSUSED */ 165static void 166dnode_dest(void *arg, void *unused) 167{ 168 int i; 169 dnode_t *dn = arg; 170 171 rw_destroy(&dn->dn_struct_rwlock); 172 mutex_destroy(&dn->dn_mtx); 173 mutex_destroy(&dn->dn_dbufs_mtx); 174 cv_destroy(&dn->dn_notxholds); 175 refcount_destroy(&dn->dn_holds); 176 refcount_destroy(&dn->dn_tx_holds); 177 ASSERT(!list_link_active(&dn->dn_link)); 178 179 for (i = 0; i < TXG_SIZE; i++) { 180 ASSERT(!list_link_active(&dn->dn_dirty_link[i])); 181 ASSERT3P(dn->dn_free_ranges[i], ==, NULL); 182 list_destroy(&dn->dn_dirty_records[i]); 183 ASSERT0(dn->dn_next_nblkptr[i]); 184 ASSERT0(dn->dn_next_nlevels[i]); 185 ASSERT0(dn->dn_next_indblkshift[i]); 186 ASSERT0(dn->dn_next_bonustype[i]); 187 ASSERT0(dn->dn_rm_spillblk[i]); 188 ASSERT0(dn->dn_next_bonuslen[i]); 189 ASSERT0(dn->dn_next_blksz[i]); 190 } 191 192 ASSERT0(dn->dn_allocated_txg); 193 ASSERT0(dn->dn_free_txg); 194 ASSERT0(dn->dn_assigned_txg); 195 ASSERT0(dn->dn_dirtyctx); 196 ASSERT3P(dn->dn_dirtyctx_firstset, ==, NULL); 197 ASSERT3P(dn->dn_bonus, ==, NULL); 198 ASSERT(!dn->dn_have_spill); 199 ASSERT3P(dn->dn_zio, ==, NULL); 200 ASSERT0(dn->dn_oldused); 201 ASSERT0(dn->dn_oldflags); 202 ASSERT0(dn->dn_olduid); 203 ASSERT0(dn->dn_oldgid); 204 ASSERT0(dn->dn_newuid); 205 ASSERT0(dn->dn_newgid); 206 ASSERT0(dn->dn_id_flags); 207 208 ASSERT0(dn->dn_dbufs_count); 209 ASSERT0(dn->dn_unlisted_l0_blkid); 210 avl_destroy(&dn->dn_dbufs); 211} 212 213void 214dnode_init(void) 215{ 216 ASSERT(dnode_cache == NULL); 217 dnode_cache = kmem_cache_create("dnode_t", 218 sizeof (dnode_t), 219 0, dnode_cons, dnode_dest, NULL, NULL, NULL, 0); 220 kmem_cache_set_move(dnode_cache, dnode_move); 221} 222 223void 224dnode_fini(void) 225{ 226 kmem_cache_destroy(dnode_cache); 227 dnode_cache = NULL; 228} 229 230 231#ifdef ZFS_DEBUG 232void 233dnode_verify(dnode_t *dn) 234{ 235 int drop_struct_lock = FALSE; 236 237 ASSERT(dn->dn_phys); 238 ASSERT(dn->dn_objset); 239 ASSERT(dn->dn_handle->dnh_dnode == dn); 240 241 ASSERT(DMU_OT_IS_VALID(dn->dn_phys->dn_type)); 242 243 if (!(zfs_flags & ZFS_DEBUG_DNODE_VERIFY)) 244 return; 245 246 if (!RW_WRITE_HELD(&dn->dn_struct_rwlock)) { 247 rw_enter(&dn->dn_struct_rwlock, RW_READER); 248 drop_struct_lock = TRUE; 249 } 250 if (dn->dn_phys->dn_type != DMU_OT_NONE || dn->dn_allocated_txg != 0) { 251 int i; 252 ASSERT3U(dn->dn_indblkshift, >=, 0); 253 ASSERT3U(dn->dn_indblkshift, <=, SPA_MAXBLOCKSHIFT); 254 if (dn->dn_datablkshift) { 255 ASSERT3U(dn->dn_datablkshift, >=, SPA_MINBLOCKSHIFT); 256 ASSERT3U(dn->dn_datablkshift, <=, SPA_MAXBLOCKSHIFT); 257 ASSERT3U(1<<dn->dn_datablkshift, ==, dn->dn_datablksz); 258 } 259 ASSERT3U(dn->dn_nlevels, <=, 30); 260 ASSERT(DMU_OT_IS_VALID(dn->dn_type)); 261 ASSERT3U(dn->dn_nblkptr, >=, 1); 262 ASSERT3U(dn->dn_nblkptr, <=, DN_MAX_NBLKPTR); 263 ASSERT3U(dn->dn_bonuslen, <=, DN_MAX_BONUSLEN); 264 ASSERT3U(dn->dn_datablksz, ==, 265 dn->dn_datablkszsec << SPA_MINBLOCKSHIFT); 266 ASSERT3U(ISP2(dn->dn_datablksz), ==, dn->dn_datablkshift != 0); 267 ASSERT3U((dn->dn_nblkptr - 1) * sizeof (blkptr_t) + 268 dn->dn_bonuslen, <=, DN_MAX_BONUSLEN); 269 for (i = 0; i < TXG_SIZE; i++) { 270 ASSERT3U(dn->dn_next_nlevels[i], <=, dn->dn_nlevels); 271 } 272 } 273 if (dn->dn_phys->dn_type != DMU_OT_NONE) 274 ASSERT3U(dn->dn_phys->dn_nlevels, <=, dn->dn_nlevels); 275 ASSERT(DMU_OBJECT_IS_SPECIAL(dn->dn_object) || dn->dn_dbuf != NULL); 276 if (dn->dn_dbuf != NULL) { 277 ASSERT3P(dn->dn_phys, ==, 278 (dnode_phys_t *)dn->dn_dbuf->db.db_data + 279 (dn->dn_object % (dn->dn_dbuf->db.db_size >> DNODE_SHIFT))); 280 } 281 if (drop_struct_lock) 282 rw_exit(&dn->dn_struct_rwlock); 283} 284#endif 285 286void 287dnode_byteswap(dnode_phys_t *dnp) 288{ 289 uint64_t *buf64 = (void*)&dnp->dn_blkptr; 290 int i; 291 292 if (dnp->dn_type == DMU_OT_NONE) { 293 bzero(dnp, sizeof (dnode_phys_t)); 294 return; 295 } 296 297 dnp->dn_datablkszsec = BSWAP_16(dnp->dn_datablkszsec); 298 dnp->dn_bonuslen = BSWAP_16(dnp->dn_bonuslen); 299 dnp->dn_maxblkid = BSWAP_64(dnp->dn_maxblkid); 300 dnp->dn_used = BSWAP_64(dnp->dn_used); 301 302 /* 303 * dn_nblkptr is only one byte, so it's OK to read it in either 304 * byte order. We can't read dn_bouslen. 305 */ 306 ASSERT(dnp->dn_indblkshift <= SPA_MAXBLOCKSHIFT); 307 ASSERT(dnp->dn_nblkptr <= DN_MAX_NBLKPTR); 308 for (i = 0; i < dnp->dn_nblkptr * sizeof (blkptr_t)/8; i++) 309 buf64[i] = BSWAP_64(buf64[i]); 310 311 /* 312 * OK to check dn_bonuslen for zero, because it won't matter if 313 * we have the wrong byte order. This is necessary because the 314 * dnode dnode is smaller than a regular dnode. 315 */ 316 if (dnp->dn_bonuslen != 0) { 317 /* 318 * Note that the bonus length calculated here may be 319 * longer than the actual bonus buffer. This is because 320 * we always put the bonus buffer after the last block 321 * pointer (instead of packing it against the end of the 322 * dnode buffer). 323 */ 324 int off = (dnp->dn_nblkptr-1) * sizeof (blkptr_t); 325 size_t len = DN_MAX_BONUSLEN - off; 326 ASSERT(DMU_OT_IS_VALID(dnp->dn_bonustype)); 327 dmu_object_byteswap_t byteswap = 328 DMU_OT_BYTESWAP(dnp->dn_bonustype); 329 dmu_ot_byteswap[byteswap].ob_func(dnp->dn_bonus + off, len); 330 } 331 332 /* Swap SPILL block if we have one */ 333 if (dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) 334 byteswap_uint64_array(&dnp->dn_spill, sizeof (blkptr_t)); 335 336} 337 338void 339dnode_buf_byteswap(void *vbuf, size_t size) 340{ 341 dnode_phys_t *buf = vbuf; 342 int i; 343 344 ASSERT3U(sizeof (dnode_phys_t), ==, (1<<DNODE_SHIFT)); 345 ASSERT((size & (sizeof (dnode_phys_t)-1)) == 0); 346 347 size >>= DNODE_SHIFT; 348 for (i = 0; i < size; i++) { 349 dnode_byteswap(buf); 350 buf++; 351 } 352} 353 354void 355dnode_setbonuslen(dnode_t *dn, int newsize, dmu_tx_t *tx) 356{ 357 ASSERT3U(refcount_count(&dn->dn_holds), >=, 1); 358 359 dnode_setdirty(dn, tx); 360 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 361 ASSERT3U(newsize, <=, DN_MAX_BONUSLEN - 362 (dn->dn_nblkptr-1) * sizeof (blkptr_t)); 363 dn->dn_bonuslen = newsize; 364 if (newsize == 0) 365 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = DN_ZERO_BONUSLEN; 366 else 367 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = dn->dn_bonuslen; 368 rw_exit(&dn->dn_struct_rwlock); 369} 370 371void 372dnode_setbonus_type(dnode_t *dn, dmu_object_type_t newtype, dmu_tx_t *tx) 373{ 374 ASSERT3U(refcount_count(&dn->dn_holds), >=, 1); 375 dnode_setdirty(dn, tx); 376 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 377 dn->dn_bonustype = newtype; 378 dn->dn_next_bonustype[tx->tx_txg & TXG_MASK] = dn->dn_bonustype; 379 rw_exit(&dn->dn_struct_rwlock); 380} 381 382void 383dnode_rm_spill(dnode_t *dn, dmu_tx_t *tx) 384{ 385 ASSERT3U(refcount_count(&dn->dn_holds), >=, 1); 386 ASSERT(RW_WRITE_HELD(&dn->dn_struct_rwlock)); 387 dnode_setdirty(dn, tx); 388 dn->dn_rm_spillblk[tx->tx_txg&TXG_MASK] = DN_KILL_SPILLBLK; 389 dn->dn_have_spill = B_FALSE; 390} 391 392static void 393dnode_setdblksz(dnode_t *dn, int size) 394{ 395 ASSERT0(P2PHASE(size, SPA_MINBLOCKSIZE)); 396 ASSERT3U(size, <=, SPA_MAXBLOCKSIZE); 397 ASSERT3U(size, >=, SPA_MINBLOCKSIZE); 398 ASSERT3U(size >> SPA_MINBLOCKSHIFT, <, 399 1<<(sizeof (dn->dn_phys->dn_datablkszsec) * 8)); 400 dn->dn_datablksz = size; 401 dn->dn_datablkszsec = size >> SPA_MINBLOCKSHIFT; 402 dn->dn_datablkshift = ISP2(size) ? highbit64(size - 1) : 0; 403} 404 405static dnode_t * 406dnode_create(objset_t *os, dnode_phys_t *dnp, dmu_buf_impl_t *db, 407 uint64_t object, dnode_handle_t *dnh) 408{ 409 dnode_t *dn; 410 411 dn = kmem_cache_alloc(dnode_cache, KM_SLEEP); 412 ASSERT(!POINTER_IS_VALID(dn->dn_objset)); 413 dn->dn_moved = 0; 414 415 /* 416 * Defer setting dn_objset until the dnode is ready to be a candidate 417 * for the dnode_move() callback. 418 */ 419 dn->dn_object = object; 420 dn->dn_dbuf = db; 421 dn->dn_handle = dnh; 422 dn->dn_phys = dnp; 423 424 if (dnp->dn_datablkszsec) { 425 dnode_setdblksz(dn, dnp->dn_datablkszsec << SPA_MINBLOCKSHIFT); 426 } else { 427 dn->dn_datablksz = 0; 428 dn->dn_datablkszsec = 0; 429 dn->dn_datablkshift = 0; 430 } 431 dn->dn_indblkshift = dnp->dn_indblkshift; 432 dn->dn_nlevels = dnp->dn_nlevels; 433 dn->dn_type = dnp->dn_type; 434 dn->dn_nblkptr = dnp->dn_nblkptr; 435 dn->dn_checksum = dnp->dn_checksum; 436 dn->dn_compress = dnp->dn_compress; 437 dn->dn_bonustype = dnp->dn_bonustype; 438 dn->dn_bonuslen = dnp->dn_bonuslen; 439 dn->dn_maxblkid = dnp->dn_maxblkid; 440 dn->dn_have_spill = ((dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) != 0); 441 dn->dn_id_flags = 0; 442 443 dmu_zfetch_init(&dn->dn_zfetch, dn); 444 445 ASSERT(DMU_OT_IS_VALID(dn->dn_phys->dn_type)); 446 447 mutex_enter(&os->os_lock); 448 if (dnh->dnh_dnode != NULL) { 449 /* Lost the allocation race. */ 450 mutex_exit(&os->os_lock); 451 kmem_cache_free(dnode_cache, dn); 452 return (dnh->dnh_dnode); 453 } 454 455 /* 456 * Exclude special dnodes from os_dnodes so an empty os_dnodes 457 * signifies that the special dnodes have no references from 458 * their children (the entries in os_dnodes). This allows 459 * dnode_destroy() to easily determine if the last child has 460 * been removed and then complete eviction of the objset. 461 */ 462 if (!DMU_OBJECT_IS_SPECIAL(object)) 463 list_insert_head(&os->os_dnodes, dn); 464 membar_producer(); 465 466 /* 467 * Everything else must be valid before assigning dn_objset 468 * makes the dnode eligible for dnode_move(). 469 */ 470 dn->dn_objset = os; 471 472 dnh->dnh_dnode = dn; 473 mutex_exit(&os->os_lock); 474 475 arc_space_consume(sizeof (dnode_t), ARC_SPACE_OTHER); 476 return (dn); 477} 478 479/* 480 * Caller must be holding the dnode handle, which is released upon return. 481 */ 482static void 483dnode_destroy(dnode_t *dn) 484{ 485 objset_t *os = dn->dn_objset; 486 boolean_t complete_os_eviction = B_FALSE; 487 488 ASSERT((dn->dn_id_flags & DN_ID_NEW_EXIST) == 0); 489 490 mutex_enter(&os->os_lock); 491 POINTER_INVALIDATE(&dn->dn_objset); 492 if (!DMU_OBJECT_IS_SPECIAL(dn->dn_object)) { 493 list_remove(&os->os_dnodes, dn); 494 complete_os_eviction = 495 list_is_empty(&os->os_dnodes) && 496 list_link_active(&os->os_evicting_node); 497 } 498 mutex_exit(&os->os_lock); 499 500 /* the dnode can no longer move, so we can release the handle */ 501 zrl_remove(&dn->dn_handle->dnh_zrlock); 502 503 dn->dn_allocated_txg = 0; 504 dn->dn_free_txg = 0; 505 dn->dn_assigned_txg = 0; 506 507 dn->dn_dirtyctx = 0; 508 if (dn->dn_dirtyctx_firstset != NULL) { 509 kmem_free(dn->dn_dirtyctx_firstset, 1); 510 dn->dn_dirtyctx_firstset = NULL; 511 } 512 if (dn->dn_bonus != NULL) { 513 mutex_enter(&dn->dn_bonus->db_mtx); 514 dbuf_evict(dn->dn_bonus); 515 dn->dn_bonus = NULL; 516 } 517 dn->dn_zio = NULL; 518 519 dn->dn_have_spill = B_FALSE; 520 dn->dn_oldused = 0; 521 dn->dn_oldflags = 0; 522 dn->dn_olduid = 0; 523 dn->dn_oldgid = 0; 524 dn->dn_newuid = 0; 525 dn->dn_newgid = 0; 526 dn->dn_id_flags = 0; 527 dn->dn_unlisted_l0_blkid = 0; 528 529 dmu_zfetch_fini(&dn->dn_zfetch); 530 kmem_cache_free(dnode_cache, dn); 531 arc_space_return(sizeof (dnode_t), ARC_SPACE_OTHER); 532 533 if (complete_os_eviction) 534 dmu_objset_evict_done(os); 535} 536 537void 538dnode_allocate(dnode_t *dn, dmu_object_type_t ot, int blocksize, int ibs, 539 dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx) 540{ 541 int i; 542 543 ASSERT3U(blocksize, <=, 544 spa_maxblocksize(dmu_objset_spa(dn->dn_objset))); 545 if (blocksize == 0) 546 blocksize = 1 << zfs_default_bs; 547 else 548 blocksize = P2ROUNDUP(blocksize, SPA_MINBLOCKSIZE); 549 550 if (ibs == 0) 551 ibs = zfs_default_ibs; 552 553 ibs = MIN(MAX(ibs, DN_MIN_INDBLKSHIFT), DN_MAX_INDBLKSHIFT); 554 555 dprintf("os=%p obj=%llu txg=%llu blocksize=%d ibs=%d\n", dn->dn_objset, 556 dn->dn_object, tx->tx_txg, blocksize, ibs); 557 558 ASSERT(dn->dn_type == DMU_OT_NONE); 559 ASSERT(bcmp(dn->dn_phys, &dnode_phys_zero, sizeof (dnode_phys_t)) == 0); 560 ASSERT(dn->dn_phys->dn_type == DMU_OT_NONE); 561 ASSERT(ot != DMU_OT_NONE); 562 ASSERT(DMU_OT_IS_VALID(ot)); 563 ASSERT((bonustype == DMU_OT_NONE && bonuslen == 0) || 564 (bonustype == DMU_OT_SA && bonuslen == 0) || 565 (bonustype != DMU_OT_NONE && bonuslen != 0)); 566 ASSERT(DMU_OT_IS_VALID(bonustype)); 567 ASSERT3U(bonuslen, <=, DN_MAX_BONUSLEN); 568 ASSERT(dn->dn_type == DMU_OT_NONE); 569 ASSERT0(dn->dn_maxblkid); 570 ASSERT0(dn->dn_allocated_txg); 571 ASSERT0(dn->dn_assigned_txg); 572 ASSERT(refcount_is_zero(&dn->dn_tx_holds)); 573 ASSERT3U(refcount_count(&dn->dn_holds), <=, 1); 574 ASSERT(avl_is_empty(&dn->dn_dbufs)); 575 576 for (i = 0; i < TXG_SIZE; i++) { 577 ASSERT0(dn->dn_next_nblkptr[i]); 578 ASSERT0(dn->dn_next_nlevels[i]); 579 ASSERT0(dn->dn_next_indblkshift[i]); 580 ASSERT0(dn->dn_next_bonuslen[i]); 581 ASSERT0(dn->dn_next_bonustype[i]); 582 ASSERT0(dn->dn_rm_spillblk[i]); 583 ASSERT0(dn->dn_next_blksz[i]); 584 ASSERT(!list_link_active(&dn->dn_dirty_link[i])); 585 ASSERT3P(list_head(&dn->dn_dirty_records[i]), ==, NULL); 586 ASSERT3P(dn->dn_free_ranges[i], ==, NULL); 587 } 588 589 dn->dn_type = ot; 590 dnode_setdblksz(dn, blocksize); 591 dn->dn_indblkshift = ibs; 592 dn->dn_nlevels = 1; 593 if (bonustype == DMU_OT_SA) /* Maximize bonus space for SA */ 594 dn->dn_nblkptr = 1; 595 else 596 dn->dn_nblkptr = 1 + 597 ((DN_MAX_BONUSLEN - bonuslen) >> SPA_BLKPTRSHIFT); 598 dn->dn_bonustype = bonustype; 599 dn->dn_bonuslen = bonuslen; 600 dn->dn_checksum = ZIO_CHECKSUM_INHERIT; 601 dn->dn_compress = ZIO_COMPRESS_INHERIT; 602 dn->dn_dirtyctx = 0; 603 604 dn->dn_free_txg = 0; 605 if (dn->dn_dirtyctx_firstset) { 606 kmem_free(dn->dn_dirtyctx_firstset, 1); 607 dn->dn_dirtyctx_firstset = NULL; 608 } 609 610 dn->dn_allocated_txg = tx->tx_txg; 611 dn->dn_id_flags = 0; 612 613 dnode_setdirty(dn, tx); 614 dn->dn_next_indblkshift[tx->tx_txg & TXG_MASK] = ibs; 615 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = dn->dn_bonuslen; 616 dn->dn_next_bonustype[tx->tx_txg & TXG_MASK] = dn->dn_bonustype; 617 dn->dn_next_blksz[tx->tx_txg & TXG_MASK] = dn->dn_datablksz; 618} 619 620void 621dnode_reallocate(dnode_t *dn, dmu_object_type_t ot, int blocksize, 622 dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx) 623{ 624 int nblkptr; 625 626 ASSERT3U(blocksize, >=, SPA_MINBLOCKSIZE); 627 ASSERT3U(blocksize, <=, 628 spa_maxblocksize(dmu_objset_spa(dn->dn_objset))); 629 ASSERT0(blocksize % SPA_MINBLOCKSIZE); 630 ASSERT(dn->dn_object != DMU_META_DNODE_OBJECT || dmu_tx_private_ok(tx)); 631 ASSERT(tx->tx_txg != 0); 632 ASSERT((bonustype == DMU_OT_NONE && bonuslen == 0) || 633 (bonustype != DMU_OT_NONE && bonuslen != 0) || 634 (bonustype == DMU_OT_SA && bonuslen == 0)); 635 ASSERT(DMU_OT_IS_VALID(bonustype)); 636 ASSERT3U(bonuslen, <=, DN_MAX_BONUSLEN); 637 638 /* clean up any unreferenced dbufs */ 639 dnode_evict_dbufs(dn); 640 641 dn->dn_id_flags = 0; 642 643 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 644 dnode_setdirty(dn, tx); 645 if (dn->dn_datablksz != blocksize) { 646 /* change blocksize */ 647 ASSERT(dn->dn_maxblkid == 0 && 648 (BP_IS_HOLE(&dn->dn_phys->dn_blkptr[0]) || 649 dnode_block_freed(dn, 0))); 650 dnode_setdblksz(dn, blocksize); 651 dn->dn_next_blksz[tx->tx_txg&TXG_MASK] = blocksize; 652 } 653 if (dn->dn_bonuslen != bonuslen) 654 dn->dn_next_bonuslen[tx->tx_txg&TXG_MASK] = bonuslen; 655 656 if (bonustype == DMU_OT_SA) /* Maximize bonus space for SA */ 657 nblkptr = 1; 658 else 659 nblkptr = 1 + ((DN_MAX_BONUSLEN - bonuslen) >> SPA_BLKPTRSHIFT); 660 if (dn->dn_bonustype != bonustype) 661 dn->dn_next_bonustype[tx->tx_txg&TXG_MASK] = bonustype; 662 if (dn->dn_nblkptr != nblkptr) 663 dn->dn_next_nblkptr[tx->tx_txg&TXG_MASK] = nblkptr; 664 if (dn->dn_phys->dn_flags & DNODE_FLAG_SPILL_BLKPTR) { 665 dbuf_rm_spill(dn, tx); 666 dnode_rm_spill(dn, tx); 667 } 668 rw_exit(&dn->dn_struct_rwlock); 669 670 /* change type */ 671 dn->dn_type = ot; 672 673 /* change bonus size and type */ 674 mutex_enter(&dn->dn_mtx); 675 dn->dn_bonustype = bonustype; 676 dn->dn_bonuslen = bonuslen; 677 dn->dn_nblkptr = nblkptr; 678 dn->dn_checksum = ZIO_CHECKSUM_INHERIT; 679 dn->dn_compress = ZIO_COMPRESS_INHERIT; 680 ASSERT3U(dn->dn_nblkptr, <=, DN_MAX_NBLKPTR); 681 682 /* fix up the bonus db_size */ 683 if (dn->dn_bonus) { 684 dn->dn_bonus->db.db_size = 685 DN_MAX_BONUSLEN - (dn->dn_nblkptr-1) * sizeof (blkptr_t); 686 ASSERT(dn->dn_bonuslen <= dn->dn_bonus->db.db_size); 687 } 688 689 dn->dn_allocated_txg = tx->tx_txg; 690 mutex_exit(&dn->dn_mtx); 691} 692 693#ifdef DNODE_STATS 694static struct { 695 uint64_t dms_dnode_invalid; 696 uint64_t dms_dnode_recheck1; 697 uint64_t dms_dnode_recheck2; 698 uint64_t dms_dnode_special; 699 uint64_t dms_dnode_handle; 700 uint64_t dms_dnode_rwlock; 701 uint64_t dms_dnode_active; 702} dnode_move_stats; 703#endif /* DNODE_STATS */ 704 705static void 706dnode_move_impl(dnode_t *odn, dnode_t *ndn) 707{ 708 int i; 709 710 ASSERT(!RW_LOCK_HELD(&odn->dn_struct_rwlock)); 711 ASSERT(MUTEX_NOT_HELD(&odn->dn_mtx)); 712 ASSERT(MUTEX_NOT_HELD(&odn->dn_dbufs_mtx)); 713 ASSERT(!RW_LOCK_HELD(&odn->dn_zfetch.zf_rwlock)); 714 715 /* Copy fields. */ 716 ndn->dn_objset = odn->dn_objset; 717 ndn->dn_object = odn->dn_object; 718 ndn->dn_dbuf = odn->dn_dbuf; 719 ndn->dn_handle = odn->dn_handle; 720 ndn->dn_phys = odn->dn_phys; 721 ndn->dn_type = odn->dn_type; 722 ndn->dn_bonuslen = odn->dn_bonuslen; 723 ndn->dn_bonustype = odn->dn_bonustype; 724 ndn->dn_nblkptr = odn->dn_nblkptr; 725 ndn->dn_checksum = odn->dn_checksum; 726 ndn->dn_compress = odn->dn_compress; 727 ndn->dn_nlevels = odn->dn_nlevels; 728 ndn->dn_indblkshift = odn->dn_indblkshift; 729 ndn->dn_datablkshift = odn->dn_datablkshift; 730 ndn->dn_datablkszsec = odn->dn_datablkszsec; 731 ndn->dn_datablksz = odn->dn_datablksz; 732 ndn->dn_maxblkid = odn->dn_maxblkid; 733 bcopy(&odn->dn_next_nblkptr[0], &ndn->dn_next_nblkptr[0], 734 sizeof (odn->dn_next_nblkptr)); 735 bcopy(&odn->dn_next_nlevels[0], &ndn->dn_next_nlevels[0], 736 sizeof (odn->dn_next_nlevels)); 737 bcopy(&odn->dn_next_indblkshift[0], &ndn->dn_next_indblkshift[0], 738 sizeof (odn->dn_next_indblkshift)); 739 bcopy(&odn->dn_next_bonustype[0], &ndn->dn_next_bonustype[0], 740 sizeof (odn->dn_next_bonustype)); 741 bcopy(&odn->dn_rm_spillblk[0], &ndn->dn_rm_spillblk[0], 742 sizeof (odn->dn_rm_spillblk)); 743 bcopy(&odn->dn_next_bonuslen[0], &ndn->dn_next_bonuslen[0], 744 sizeof (odn->dn_next_bonuslen)); 745 bcopy(&odn->dn_next_blksz[0], &ndn->dn_next_blksz[0], 746 sizeof (odn->dn_next_blksz)); 747 for (i = 0; i < TXG_SIZE; i++) { 748 list_move_tail(&ndn->dn_dirty_records[i], 749 &odn->dn_dirty_records[i]); 750 } 751 bcopy(&odn->dn_free_ranges[0], &ndn->dn_free_ranges[0], 752 sizeof (odn->dn_free_ranges)); 753 ndn->dn_allocated_txg = odn->dn_allocated_txg; 754 ndn->dn_free_txg = odn->dn_free_txg; 755 ndn->dn_assigned_txg = odn->dn_assigned_txg; 756 ndn->dn_dirtyctx = odn->dn_dirtyctx; 757 ndn->dn_dirtyctx_firstset = odn->dn_dirtyctx_firstset; 758 ASSERT(refcount_count(&odn->dn_tx_holds) == 0); 759 refcount_transfer(&ndn->dn_holds, &odn->dn_holds); 760 ASSERT(avl_is_empty(&ndn->dn_dbufs)); 761 avl_swap(&ndn->dn_dbufs, &odn->dn_dbufs); 762 ndn->dn_dbufs_count = odn->dn_dbufs_count; 763 ndn->dn_unlisted_l0_blkid = odn->dn_unlisted_l0_blkid; 764 ndn->dn_bonus = odn->dn_bonus; 765 ndn->dn_have_spill = odn->dn_have_spill; 766 ndn->dn_zio = odn->dn_zio; 767 ndn->dn_oldused = odn->dn_oldused; 768 ndn->dn_oldflags = odn->dn_oldflags; 769 ndn->dn_olduid = odn->dn_olduid; 770 ndn->dn_oldgid = odn->dn_oldgid; 771 ndn->dn_newuid = odn->dn_newuid; 772 ndn->dn_newgid = odn->dn_newgid; 773 ndn->dn_id_flags = odn->dn_id_flags; 774 dmu_zfetch_init(&ndn->dn_zfetch, NULL); 775 list_move_tail(&ndn->dn_zfetch.zf_stream, &odn->dn_zfetch.zf_stream); 776 ndn->dn_zfetch.zf_dnode = odn->dn_zfetch.zf_dnode; 777 778 /* 779 * Update back pointers. Updating the handle fixes the back pointer of 780 * every descendant dbuf as well as the bonus dbuf. 781 */ 782 ASSERT(ndn->dn_handle->dnh_dnode == odn); 783 ndn->dn_handle->dnh_dnode = ndn; 784 if (ndn->dn_zfetch.zf_dnode == odn) { 785 ndn->dn_zfetch.zf_dnode = ndn; 786 } 787 788 /* 789 * Invalidate the original dnode by clearing all of its back pointers. 790 */ 791 odn->dn_dbuf = NULL; 792 odn->dn_handle = NULL; 793 avl_create(&odn->dn_dbufs, dbuf_compare, sizeof (dmu_buf_impl_t), 794 offsetof(dmu_buf_impl_t, db_link)); 795 odn->dn_dbufs_count = 0; 796 odn->dn_unlisted_l0_blkid = 0; 797 odn->dn_bonus = NULL; 798 odn->dn_zfetch.zf_dnode = NULL; 799 800 /* 801 * Set the low bit of the objset pointer to ensure that dnode_move() 802 * recognizes the dnode as invalid in any subsequent callback. 803 */ 804 POINTER_INVALIDATE(&odn->dn_objset); 805 806 /* 807 * Satisfy the destructor. 808 */ 809 for (i = 0; i < TXG_SIZE; i++) { 810 list_create(&odn->dn_dirty_records[i], 811 sizeof (dbuf_dirty_record_t), 812 offsetof(dbuf_dirty_record_t, dr_dirty_node)); 813 odn->dn_free_ranges[i] = NULL; 814 odn->dn_next_nlevels[i] = 0; 815 odn->dn_next_indblkshift[i] = 0; 816 odn->dn_next_bonustype[i] = 0; 817 odn->dn_rm_spillblk[i] = 0; 818 odn->dn_next_bonuslen[i] = 0; 819 odn->dn_next_blksz[i] = 0; 820 } 821 odn->dn_allocated_txg = 0; 822 odn->dn_free_txg = 0; 823 odn->dn_assigned_txg = 0; 824 odn->dn_dirtyctx = 0; 825 odn->dn_dirtyctx_firstset = NULL; 826 odn->dn_have_spill = B_FALSE; 827 odn->dn_zio = NULL; 828 odn->dn_oldused = 0; 829 odn->dn_oldflags = 0; 830 odn->dn_olduid = 0; 831 odn->dn_oldgid = 0; 832 odn->dn_newuid = 0; 833 odn->dn_newgid = 0; 834 odn->dn_id_flags = 0; 835 836 /* 837 * Mark the dnode. 838 */ 839 ndn->dn_moved = 1; 840 odn->dn_moved = (uint8_t)-1; 841} 842 843#ifdef illumos 844#ifdef _KERNEL 845/*ARGSUSED*/ 846static kmem_cbrc_t 847dnode_move(void *buf, void *newbuf, size_t size, void *arg) 848{ 849 dnode_t *odn = buf, *ndn = newbuf; 850 objset_t *os; 851 int64_t refcount; 852 uint32_t dbufs; 853 854 /* 855 * The dnode is on the objset's list of known dnodes if the objset 856 * pointer is valid. We set the low bit of the objset pointer when 857 * freeing the dnode to invalidate it, and the memory patterns written 858 * by kmem (baddcafe and deadbeef) set at least one of the two low bits. 859 * A newly created dnode sets the objset pointer last of all to indicate 860 * that the dnode is known and in a valid state to be moved by this 861 * function. 862 */ 863 os = odn->dn_objset; 864 if (!POINTER_IS_VALID(os)) { 865 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_invalid); 866 return (KMEM_CBRC_DONT_KNOW); 867 } 868 869 /* 870 * Ensure that the objset does not go away during the move. 871 */ 872 rw_enter(&os_lock, RW_WRITER); 873 if (os != odn->dn_objset) { 874 rw_exit(&os_lock); 875 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_recheck1); 876 return (KMEM_CBRC_DONT_KNOW); 877 } 878 879 /* 880 * If the dnode is still valid, then so is the objset. We know that no 881 * valid objset can be freed while we hold os_lock, so we can safely 882 * ensure that the objset remains in use. 883 */ 884 mutex_enter(&os->os_lock); 885 886 /* 887 * Recheck the objset pointer in case the dnode was removed just before 888 * acquiring the lock. 889 */ 890 if (os != odn->dn_objset) { 891 mutex_exit(&os->os_lock); 892 rw_exit(&os_lock); 893 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_recheck2); 894 return (KMEM_CBRC_DONT_KNOW); 895 } 896 897 /* 898 * At this point we know that as long as we hold os->os_lock, the dnode 899 * cannot be freed and fields within the dnode can be safely accessed. 900 * The objset listing this dnode cannot go away as long as this dnode is 901 * on its list. 902 */ 903 rw_exit(&os_lock); 904 if (DMU_OBJECT_IS_SPECIAL(odn->dn_object)) { 905 mutex_exit(&os->os_lock); 906 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_special); 907 return (KMEM_CBRC_NO); 908 } 909 ASSERT(odn->dn_dbuf != NULL); /* only "special" dnodes have no parent */ 910 911 /* 912 * Lock the dnode handle to prevent the dnode from obtaining any new 913 * holds. This also prevents the descendant dbufs and the bonus dbuf 914 * from accessing the dnode, so that we can discount their holds. The 915 * handle is safe to access because we know that while the dnode cannot 916 * go away, neither can its handle. Once we hold dnh_zrlock, we can 917 * safely move any dnode referenced only by dbufs. 918 */ 919 if (!zrl_tryenter(&odn->dn_handle->dnh_zrlock)) { 920 mutex_exit(&os->os_lock); 921 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_handle); 922 return (KMEM_CBRC_LATER); 923 } 924 925 /* 926 * Ensure a consistent view of the dnode's holds and the dnode's dbufs. 927 * We need to guarantee that there is a hold for every dbuf in order to 928 * determine whether the dnode is actively referenced. Falsely matching 929 * a dbuf to an active hold would lead to an unsafe move. It's possible 930 * that a thread already having an active dnode hold is about to add a 931 * dbuf, and we can't compare hold and dbuf counts while the add is in 932 * progress. 933 */ 934 if (!rw_tryenter(&odn->dn_struct_rwlock, RW_WRITER)) { 935 zrl_exit(&odn->dn_handle->dnh_zrlock); 936 mutex_exit(&os->os_lock); 937 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_rwlock); 938 return (KMEM_CBRC_LATER); 939 } 940 941 /* 942 * A dbuf may be removed (evicted) without an active dnode hold. In that 943 * case, the dbuf count is decremented under the handle lock before the 944 * dbuf's hold is released. This order ensures that if we count the hold 945 * after the dbuf is removed but before its hold is released, we will 946 * treat the unmatched hold as active and exit safely. If we count the 947 * hold before the dbuf is removed, the hold is discounted, and the 948 * removal is blocked until the move completes. 949 */ 950 refcount = refcount_count(&odn->dn_holds); 951 ASSERT(refcount >= 0); 952 dbufs = odn->dn_dbufs_count; 953 954 /* We can't have more dbufs than dnode holds. */ 955 ASSERT3U(dbufs, <=, refcount); 956 DTRACE_PROBE3(dnode__move, dnode_t *, odn, int64_t, refcount, 957 uint32_t, dbufs); 958 959 if (refcount > dbufs) { 960 rw_exit(&odn->dn_struct_rwlock); 961 zrl_exit(&odn->dn_handle->dnh_zrlock); 962 mutex_exit(&os->os_lock); 963 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_active); 964 return (KMEM_CBRC_LATER); 965 } 966 967 rw_exit(&odn->dn_struct_rwlock); 968 969 /* 970 * At this point we know that anyone with a hold on the dnode is not 971 * actively referencing it. The dnode is known and in a valid state to 972 * move. We're holding the locks needed to execute the critical section. 973 */ 974 dnode_move_impl(odn, ndn); 975 976 list_link_replace(&odn->dn_link, &ndn->dn_link); 977 /* If the dnode was safe to move, the refcount cannot have changed. */ 978 ASSERT(refcount == refcount_count(&ndn->dn_holds)); 979 ASSERT(dbufs == ndn->dn_dbufs_count); 980 zrl_exit(&ndn->dn_handle->dnh_zrlock); /* handle has moved */ 981 mutex_exit(&os->os_lock); 982 983 return (KMEM_CBRC_YES); 984} 985#endif /* _KERNEL */ 986#endif /* illumos */ 987 988void 989dnode_special_close(dnode_handle_t *dnh) 990{ 991 dnode_t *dn = dnh->dnh_dnode; 992 993 /* 994 * Wait for final references to the dnode to clear. This can 995 * only happen if the arc is asyncronously evicting state that 996 * has a hold on this dnode while we are trying to evict this 997 * dnode. 998 */ 999 while (refcount_count(&dn->dn_holds) > 0) 1000 delay(1); 1001 ASSERT(dn->dn_dbuf == NULL || 1002 dmu_buf_get_user(&dn->dn_dbuf->db) == NULL); 1003 zrl_add(&dnh->dnh_zrlock); 1004 dnode_destroy(dn); /* implicit zrl_remove() */ 1005 zrl_destroy(&dnh->dnh_zrlock); 1006 dnh->dnh_dnode = NULL; 1007} 1008 1009void 1010dnode_special_open(objset_t *os, dnode_phys_t *dnp, uint64_t object, 1011 dnode_handle_t *dnh) 1012{ 1013 dnode_t *dn; 1014 1015 dn = dnode_create(os, dnp, NULL, object, dnh); 1016 zrl_init(&dnh->dnh_zrlock); 1017 DNODE_VERIFY(dn); 1018} 1019 1020static void 1021dnode_buf_pageout(void *dbu) 1022{ 1023 dnode_children_t *children_dnodes = dbu; 1024 int i; 1025 1026 for (i = 0; i < children_dnodes->dnc_count; i++) { 1027 dnode_handle_t *dnh = &children_dnodes->dnc_children[i]; 1028 dnode_t *dn; 1029 1030 /* 1031 * The dnode handle lock guards against the dnode moving to 1032 * another valid address, so there is no need here to guard 1033 * against changes to or from NULL. 1034 */ 1035 if (dnh->dnh_dnode == NULL) { 1036 zrl_destroy(&dnh->dnh_zrlock); 1037 continue; 1038 } 1039 1040 zrl_add(&dnh->dnh_zrlock); 1041 dn = dnh->dnh_dnode; 1042 /* 1043 * If there are holds on this dnode, then there should 1044 * be holds on the dnode's containing dbuf as well; thus 1045 * it wouldn't be eligible for eviction and this function 1046 * would not have been called. 1047 */ 1048 ASSERT(refcount_is_zero(&dn->dn_holds)); 1049 ASSERT(refcount_is_zero(&dn->dn_tx_holds)); 1050 1051 dnode_destroy(dn); /* implicit zrl_remove() */ 1052 zrl_destroy(&dnh->dnh_zrlock); 1053 dnh->dnh_dnode = NULL; 1054 } 1055 kmem_free(children_dnodes, sizeof (dnode_children_t) + 1056 children_dnodes->dnc_count * sizeof (dnode_handle_t)); 1057} 1058 1059/* 1060 * errors: 1061 * EINVAL - invalid object number. 1062 * EIO - i/o error. 1063 * succeeds even for free dnodes. 1064 */ 1065int 1066dnode_hold_impl(objset_t *os, uint64_t object, int flag, 1067 void *tag, dnode_t **dnp) 1068{ 1069 int epb, idx, err; 1070 int drop_struct_lock = FALSE; 1071 int type; 1072 uint64_t blk; 1073 dnode_t *mdn, *dn; 1074 dmu_buf_impl_t *db; 1075 dnode_children_t *children_dnodes; 1076 dnode_handle_t *dnh; 1077 1078 /* 1079 * If you are holding the spa config lock as writer, you shouldn't 1080 * be asking the DMU to do *anything* unless it's the root pool 1081 * which may require us to read from the root filesystem while 1082 * holding some (not all) of the locks as writer. 1083 */ 1084 ASSERT(spa_config_held(os->os_spa, SCL_ALL, RW_WRITER) == 0 || 1085 (spa_is_root(os->os_spa) && 1086 spa_config_held(os->os_spa, SCL_STATE, RW_WRITER))); 1087 1088 if (object == DMU_USERUSED_OBJECT || object == DMU_GROUPUSED_OBJECT) { 1089 dn = (object == DMU_USERUSED_OBJECT) ? 1090 DMU_USERUSED_DNODE(os) : DMU_GROUPUSED_DNODE(os); 1091 if (dn == NULL) 1092 return (SET_ERROR(ENOENT)); 1093 type = dn->dn_type; 1094 if ((flag & DNODE_MUST_BE_ALLOCATED) && type == DMU_OT_NONE) 1095 return (SET_ERROR(ENOENT)); 1096 if ((flag & DNODE_MUST_BE_FREE) && type != DMU_OT_NONE) 1097 return (SET_ERROR(EEXIST)); 1098 DNODE_VERIFY(dn); 1099 (void) refcount_add(&dn->dn_holds, tag); 1100 *dnp = dn; 1101 return (0); 1102 } 1103 1104 if (object == 0 || object >= DN_MAX_OBJECT) 1105 return (SET_ERROR(EINVAL)); 1106 1107 mdn = DMU_META_DNODE(os); 1108 ASSERT(mdn->dn_object == DMU_META_DNODE_OBJECT); 1109 1110 DNODE_VERIFY(mdn); 1111 1112 if (!RW_WRITE_HELD(&mdn->dn_struct_rwlock)) { 1113 rw_enter(&mdn->dn_struct_rwlock, RW_READER); 1114 drop_struct_lock = TRUE; 1115 } 1116 1117 blk = dbuf_whichblock(mdn, 0, object * sizeof (dnode_phys_t)); 1118 1119 db = dbuf_hold(mdn, blk, FTAG); 1120 if (drop_struct_lock) 1121 rw_exit(&mdn->dn_struct_rwlock); 1122 if (db == NULL) 1123 return (SET_ERROR(EIO)); 1124 err = dbuf_read(db, NULL, DB_RF_CANFAIL); 1125 if (err) { 1126 dbuf_rele(db, FTAG); 1127 return (err); 1128 } 1129 1130 ASSERT3U(db->db.db_size, >=, 1<<DNODE_SHIFT); 1131 epb = db->db.db_size >> DNODE_SHIFT; 1132 1133 idx = object & (epb-1); 1134 1135 ASSERT(DB_DNODE(db)->dn_type == DMU_OT_DNODE); 1136 children_dnodes = dmu_buf_get_user(&db->db); 1137 if (children_dnodes == NULL) { 1138 int i; 1139 dnode_children_t *winner; 1140 children_dnodes = kmem_zalloc(sizeof (dnode_children_t) + 1141 epb * sizeof (dnode_handle_t), KM_SLEEP); 1142 children_dnodes->dnc_count = epb; 1143 dnh = &children_dnodes->dnc_children[0]; 1144 for (i = 0; i < epb; i++) { 1145 zrl_init(&dnh[i].dnh_zrlock); 1146 } 1147 dmu_buf_init_user(&children_dnodes->dnc_dbu, 1148 dnode_buf_pageout, NULL); 1149 winner = dmu_buf_set_user(&db->db, &children_dnodes->dnc_dbu); 1150 if (winner != NULL) { 1151 1152 for (i = 0; i < epb; i++) { 1153 zrl_destroy(&dnh[i].dnh_zrlock); 1154 } 1155 1156 kmem_free(children_dnodes, sizeof (dnode_children_t) + 1157 epb * sizeof (dnode_handle_t)); 1158 children_dnodes = winner; 1159 } 1160 } 1161 ASSERT(children_dnodes->dnc_count == epb); 1162 1163 dnh = &children_dnodes->dnc_children[idx]; 1164 zrl_add(&dnh->dnh_zrlock); 1165 dn = dnh->dnh_dnode; 1166 if (dn == NULL) { 1167 dnode_phys_t *phys = (dnode_phys_t *)db->db.db_data+idx; 1168 1169 dn = dnode_create(os, phys, db, object, dnh); 1170 } 1171 1172 mutex_enter(&dn->dn_mtx); 1173 type = dn->dn_type; 1174 if (dn->dn_free_txg || 1175 ((flag & DNODE_MUST_BE_ALLOCATED) && type == DMU_OT_NONE) || 1176 ((flag & DNODE_MUST_BE_FREE) && 1177 (type != DMU_OT_NONE || !refcount_is_zero(&dn->dn_holds)))) { 1178 mutex_exit(&dn->dn_mtx); 1179 zrl_remove(&dnh->dnh_zrlock); 1180 dbuf_rele(db, FTAG); 1181 return (type == DMU_OT_NONE ? ENOENT : EEXIST); 1182 } 1183 if (refcount_add(&dn->dn_holds, tag) == 1) 1184 dbuf_add_ref(db, dnh); 1185 mutex_exit(&dn->dn_mtx); 1186 1187 /* Now we can rely on the hold to prevent the dnode from moving. */ 1188 zrl_remove(&dnh->dnh_zrlock); 1189 1190 DNODE_VERIFY(dn); 1191 ASSERT3P(dn->dn_dbuf, ==, db); 1192 ASSERT3U(dn->dn_object, ==, object); 1193 dbuf_rele(db, FTAG); 1194 1195 *dnp = dn; 1196 return (0); 1197} 1198 1199/* 1200 * Return held dnode if the object is allocated, NULL if not. 1201 */ 1202int 1203dnode_hold(objset_t *os, uint64_t object, void *tag, dnode_t **dnp) 1204{ 1205 return (dnode_hold_impl(os, object, DNODE_MUST_BE_ALLOCATED, tag, dnp)); 1206} 1207 1208/* 1209 * Can only add a reference if there is already at least one 1210 * reference on the dnode. Returns FALSE if unable to add a 1211 * new reference. 1212 */ 1213boolean_t 1214dnode_add_ref(dnode_t *dn, void *tag) 1215{ 1216 mutex_enter(&dn->dn_mtx); 1217 if (refcount_is_zero(&dn->dn_holds)) { 1218 mutex_exit(&dn->dn_mtx); 1219 return (FALSE); 1220 } 1221 VERIFY(1 < refcount_add(&dn->dn_holds, tag)); 1222 mutex_exit(&dn->dn_mtx); 1223 return (TRUE); 1224} 1225 1226void 1227dnode_rele(dnode_t *dn, void *tag) 1228{ 1229 mutex_enter(&dn->dn_mtx); 1230 dnode_rele_and_unlock(dn, tag); 1231} 1232 1233void 1234dnode_rele_and_unlock(dnode_t *dn, void *tag) 1235{ 1236 uint64_t refs; 1237 /* Get while the hold prevents the dnode from moving. */ 1238 dmu_buf_impl_t *db = dn->dn_dbuf; 1239 dnode_handle_t *dnh = dn->dn_handle; 1240 1241 refs = refcount_remove(&dn->dn_holds, tag); 1242 mutex_exit(&dn->dn_mtx); 1243 1244 /* 1245 * It's unsafe to release the last hold on a dnode by dnode_rele() or 1246 * indirectly by dbuf_rele() while relying on the dnode handle to 1247 * prevent the dnode from moving, since releasing the last hold could 1248 * result in the dnode's parent dbuf evicting its dnode handles. For 1249 * that reason anyone calling dnode_rele() or dbuf_rele() without some 1250 * other direct or indirect hold on the dnode must first drop the dnode 1251 * handle. 1252 */ 1253 ASSERT(refs > 0 || dnh->dnh_zrlock.zr_owner != curthread); 1254 1255 /* NOTE: the DNODE_DNODE does not have a dn_dbuf */ 1256 if (refs == 0 && db != NULL) { 1257 /* 1258 * Another thread could add a hold to the dnode handle in 1259 * dnode_hold_impl() while holding the parent dbuf. Since the 1260 * hold on the parent dbuf prevents the handle from being 1261 * destroyed, the hold on the handle is OK. We can't yet assert 1262 * that the handle has zero references, but that will be 1263 * asserted anyway when the handle gets destroyed. 1264 */ 1265 dbuf_rele(db, dnh); 1266 } 1267} 1268 1269void 1270dnode_setdirty(dnode_t *dn, dmu_tx_t *tx) 1271{ 1272 objset_t *os = dn->dn_objset; 1273 uint64_t txg = tx->tx_txg; 1274 1275 if (DMU_OBJECT_IS_SPECIAL(dn->dn_object)) { 1276 dsl_dataset_dirty(os->os_dsl_dataset, tx); 1277 return; 1278 } 1279 1280 DNODE_VERIFY(dn); 1281 1282#ifdef ZFS_DEBUG 1283 mutex_enter(&dn->dn_mtx); 1284 ASSERT(dn->dn_phys->dn_type || dn->dn_allocated_txg); 1285 ASSERT(dn->dn_free_txg == 0 || dn->dn_free_txg >= txg); 1286 mutex_exit(&dn->dn_mtx); 1287#endif 1288 1289 /* 1290 * Determine old uid/gid when necessary 1291 */ 1292 dmu_objset_userquota_get_ids(dn, B_TRUE, tx); 1293 1294 mutex_enter(&os->os_lock); 1295 1296 /* 1297 * If we are already marked dirty, we're done. 1298 */ 1299 if (list_link_active(&dn->dn_dirty_link[txg & TXG_MASK])) { 1300 mutex_exit(&os->os_lock); 1301 return; 1302 } 1303 1304 ASSERT(!refcount_is_zero(&dn->dn_holds) || 1305 !avl_is_empty(&dn->dn_dbufs)); 1306 ASSERT(dn->dn_datablksz != 0); 1307 ASSERT0(dn->dn_next_bonuslen[txg&TXG_MASK]); 1308 ASSERT0(dn->dn_next_blksz[txg&TXG_MASK]); 1309 ASSERT0(dn->dn_next_bonustype[txg&TXG_MASK]); 1310 1311 dprintf_ds(os->os_dsl_dataset, "obj=%llu txg=%llu\n", 1312 dn->dn_object, txg); 1313 1314 if (dn->dn_free_txg > 0 && dn->dn_free_txg <= txg) { 1315 list_insert_tail(&os->os_free_dnodes[txg&TXG_MASK], dn); 1316 } else { 1317 list_insert_tail(&os->os_dirty_dnodes[txg&TXG_MASK], dn); 1318 } 1319 1320 mutex_exit(&os->os_lock); 1321 1322 /* 1323 * The dnode maintains a hold on its containing dbuf as 1324 * long as there are holds on it. Each instantiated child 1325 * dbuf maintains a hold on the dnode. When the last child 1326 * drops its hold, the dnode will drop its hold on the 1327 * containing dbuf. We add a "dirty hold" here so that the 1328 * dnode will hang around after we finish processing its 1329 * children. 1330 */ 1331 VERIFY(dnode_add_ref(dn, (void *)(uintptr_t)tx->tx_txg)); 1332 1333 (void) dbuf_dirty(dn->dn_dbuf, tx); 1334 1335 dsl_dataset_dirty(os->os_dsl_dataset, tx); 1336} 1337 1338void 1339dnode_free(dnode_t *dn, dmu_tx_t *tx) 1340{ 1341 int txgoff = tx->tx_txg & TXG_MASK; 1342 1343 dprintf("dn=%p txg=%llu\n", dn, tx->tx_txg); 1344 1345 /* we should be the only holder... hopefully */ 1346 /* ASSERT3U(refcount_count(&dn->dn_holds), ==, 1); */ 1347 1348 mutex_enter(&dn->dn_mtx); 1349 if (dn->dn_type == DMU_OT_NONE || dn->dn_free_txg) { 1350 mutex_exit(&dn->dn_mtx); 1351 return; 1352 } 1353 dn->dn_free_txg = tx->tx_txg; 1354 mutex_exit(&dn->dn_mtx); 1355 1356 /* 1357 * If the dnode is already dirty, it needs to be moved from 1358 * the dirty list to the free list. 1359 */ 1360 mutex_enter(&dn->dn_objset->os_lock); 1361 if (list_link_active(&dn->dn_dirty_link[txgoff])) { 1362 list_remove(&dn->dn_objset->os_dirty_dnodes[txgoff], dn); 1363 list_insert_tail(&dn->dn_objset->os_free_dnodes[txgoff], dn); 1364 mutex_exit(&dn->dn_objset->os_lock); 1365 } else { 1366 mutex_exit(&dn->dn_objset->os_lock); 1367 dnode_setdirty(dn, tx); 1368 } 1369} 1370 1371/* 1372 * Try to change the block size for the indicated dnode. This can only 1373 * succeed if there are no blocks allocated or dirty beyond first block 1374 */ 1375int 1376dnode_set_blksz(dnode_t *dn, uint64_t size, int ibs, dmu_tx_t *tx) 1377{ 1378 dmu_buf_impl_t *db; 1379 int err; 1380 1381 ASSERT3U(size, <=, spa_maxblocksize(dmu_objset_spa(dn->dn_objset))); 1382 if (size == 0) 1383 size = SPA_MINBLOCKSIZE; 1384 else 1385 size = P2ROUNDUP(size, SPA_MINBLOCKSIZE); 1386 1387 if (ibs == dn->dn_indblkshift) 1388 ibs = 0; 1389 1390 if (size >> SPA_MINBLOCKSHIFT == dn->dn_datablkszsec && ibs == 0) 1391 return (0); 1392 1393 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 1394 1395 /* Check for any allocated blocks beyond the first */ 1396 if (dn->dn_maxblkid != 0) 1397 goto fail; 1398 1399 mutex_enter(&dn->dn_dbufs_mtx); 1400 for (db = avl_first(&dn->dn_dbufs); db != NULL; 1401 db = AVL_NEXT(&dn->dn_dbufs, db)) { 1402 if (db->db_blkid != 0 && db->db_blkid != DMU_BONUS_BLKID && 1403 db->db_blkid != DMU_SPILL_BLKID) { 1404 mutex_exit(&dn->dn_dbufs_mtx); 1405 goto fail; 1406 } 1407 } 1408 mutex_exit(&dn->dn_dbufs_mtx); 1409 1410 if (ibs && dn->dn_nlevels != 1) 1411 goto fail; 1412 1413 /* resize the old block */ 1414 err = dbuf_hold_impl(dn, 0, 0, TRUE, FALSE, FTAG, &db); 1415 if (err == 0) 1416 dbuf_new_size(db, size, tx); 1417 else if (err != ENOENT) 1418 goto fail; 1419 1420 dnode_setdblksz(dn, size); 1421 dnode_setdirty(dn, tx); 1422 dn->dn_next_blksz[tx->tx_txg&TXG_MASK] = size; 1423 if (ibs) { 1424 dn->dn_indblkshift = ibs; 1425 dn->dn_next_indblkshift[tx->tx_txg&TXG_MASK] = ibs; 1426 } 1427 /* rele after we have fixed the blocksize in the dnode */ 1428 if (db) 1429 dbuf_rele(db, FTAG); 1430 1431 rw_exit(&dn->dn_struct_rwlock); 1432 return (0); 1433 1434fail: 1435 rw_exit(&dn->dn_struct_rwlock); 1436 return (SET_ERROR(ENOTSUP)); 1437} 1438 1439/* read-holding callers must not rely on the lock being continuously held */ 1440void 1441dnode_new_blkid(dnode_t *dn, uint64_t blkid, dmu_tx_t *tx, boolean_t have_read) 1442{ 1443 uint64_t txgoff = tx->tx_txg & TXG_MASK; 1444 int epbs, new_nlevels; 1445 uint64_t sz; 1446 1447 ASSERT(blkid != DMU_BONUS_BLKID); 1448 1449 ASSERT(have_read ? 1450 RW_READ_HELD(&dn->dn_struct_rwlock) : 1451 RW_WRITE_HELD(&dn->dn_struct_rwlock)); 1452 1453 /* 1454 * if we have a read-lock, check to see if we need to do any work 1455 * before upgrading to a write-lock. 1456 */ 1457 if (have_read) { 1458 if (blkid <= dn->dn_maxblkid) 1459 return; 1460 1461 if (!rw_tryupgrade(&dn->dn_struct_rwlock)) { 1462 rw_exit(&dn->dn_struct_rwlock); 1463 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 1464 } 1465 } 1466 1467 if (blkid <= dn->dn_maxblkid) 1468 goto out; 1469 1470 dn->dn_maxblkid = blkid; 1471 1472 /* 1473 * Compute the number of levels necessary to support the new maxblkid. 1474 */ 1475 new_nlevels = 1; 1476 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT; 1477 for (sz = dn->dn_nblkptr; 1478 sz <= blkid && sz >= dn->dn_nblkptr; sz <<= epbs) 1479 new_nlevels++; 1480 1481 if (new_nlevels > dn->dn_nlevels) { 1482 int old_nlevels = dn->dn_nlevels; 1483 dmu_buf_impl_t *db; 1484 list_t *list; 1485 dbuf_dirty_record_t *new, *dr, *dr_next; 1486 1487 dn->dn_nlevels = new_nlevels; 1488 1489 ASSERT3U(new_nlevels, >, dn->dn_next_nlevels[txgoff]); 1490 dn->dn_next_nlevels[txgoff] = new_nlevels; 1491 1492 /* dirty the left indirects */ 1493 db = dbuf_hold_level(dn, old_nlevels, 0, FTAG); 1494 ASSERT(db != NULL); 1495 new = dbuf_dirty(db, tx); 1496 dbuf_rele(db, FTAG); 1497 1498 /* transfer the dirty records to the new indirect */ 1499 mutex_enter(&dn->dn_mtx); 1500 mutex_enter(&new->dt.di.dr_mtx); 1501 list = &dn->dn_dirty_records[txgoff]; 1502 for (dr = list_head(list); dr; dr = dr_next) { 1503 dr_next = list_next(&dn->dn_dirty_records[txgoff], dr); 1504 if (dr->dr_dbuf->db_level != new_nlevels-1 && 1505 dr->dr_dbuf->db_blkid != DMU_BONUS_BLKID && 1506 dr->dr_dbuf->db_blkid != DMU_SPILL_BLKID) { 1507 ASSERT(dr->dr_dbuf->db_level == old_nlevels-1); 1508 list_remove(&dn->dn_dirty_records[txgoff], dr); 1509 list_insert_tail(&new->dt.di.dr_children, dr); 1510 dr->dr_parent = new; 1511 } 1512 } 1513 mutex_exit(&new->dt.di.dr_mtx); 1514 mutex_exit(&dn->dn_mtx); 1515 } 1516 1517out: 1518 if (have_read) 1519 rw_downgrade(&dn->dn_struct_rwlock); 1520} 1521 1522static void 1523dnode_dirty_l1(dnode_t *dn, uint64_t l1blkid, dmu_tx_t *tx) 1524{ 1525 dmu_buf_impl_t *db = dbuf_hold_level(dn, 1, l1blkid, FTAG); 1526 if (db != NULL) { 1527 dmu_buf_will_dirty(&db->db, tx); 1528 dbuf_rele(db, FTAG); 1529 } 1530} 1531 1532void 1533dnode_free_range(dnode_t *dn, uint64_t off, uint64_t len, dmu_tx_t *tx) 1534{ 1535 dmu_buf_impl_t *db; 1536 uint64_t blkoff, blkid, nblks; 1537 int blksz, blkshift, head, tail; 1538 int trunc = FALSE; 1539 int epbs; 1540 1541 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 1542 blksz = dn->dn_datablksz; 1543 blkshift = dn->dn_datablkshift; 1544 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT; 1545 1546 if (len == DMU_OBJECT_END) { 1547 len = UINT64_MAX - off; 1548 trunc = TRUE; 1549 } 1550 1551 /* 1552 * First, block align the region to free: 1553 */ 1554 if (ISP2(blksz)) { 1555 head = P2NPHASE(off, blksz); 1556 blkoff = P2PHASE(off, blksz); 1557 if ((off >> blkshift) > dn->dn_maxblkid) 1558 goto out; 1559 } else { 1560 ASSERT(dn->dn_maxblkid == 0); 1561 if (off == 0 && len >= blksz) { 1562 /* 1563 * Freeing the whole block; fast-track this request. 1564 * Note that we won't dirty any indirect blocks, 1565 * which is fine because we will be freeing the entire 1566 * file and thus all indirect blocks will be freed 1567 * by free_children(). 1568 */ 1569 blkid = 0; 1570 nblks = 1; 1571 goto done; 1572 } else if (off >= blksz) { 1573 /* Freeing past end-of-data */ 1574 goto out; 1575 } else { 1576 /* Freeing part of the block. */ 1577 head = blksz - off; 1578 ASSERT3U(head, >, 0); 1579 } 1580 blkoff = off; 1581 } 1582 /* zero out any partial block data at the start of the range */ 1583 if (head) { 1584 ASSERT3U(blkoff + head, ==, blksz); 1585 if (len < head) 1586 head = len; 1587 if (dbuf_hold_impl(dn, 0, dbuf_whichblock(dn, 0, off), 1588 TRUE, FALSE, FTAG, &db) == 0) { 1589 caddr_t data; 1590 1591 /* don't dirty if it isn't on disk and isn't dirty */ 1592 if (db->db_last_dirty || 1593 (db->db_blkptr && !BP_IS_HOLE(db->db_blkptr))) { 1594 rw_exit(&dn->dn_struct_rwlock); 1595 dmu_buf_will_dirty(&db->db, tx); 1596 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 1597 data = db->db.db_data; 1598 bzero(data + blkoff, head); 1599 } 1600 dbuf_rele(db, FTAG); 1601 } 1602 off += head; 1603 len -= head; 1604 } 1605 1606 /* If the range was less than one block, we're done */ 1607 if (len == 0) 1608 goto out; 1609 1610 /* If the remaining range is past end of file, we're done */ 1611 if ((off >> blkshift) > dn->dn_maxblkid) 1612 goto out; 1613 1614 ASSERT(ISP2(blksz)); 1615 if (trunc) 1616 tail = 0; 1617 else 1618 tail = P2PHASE(len, blksz); 1619 1620 ASSERT0(P2PHASE(off, blksz)); 1621 /* zero out any partial block data at the end of the range */ 1622 if (tail) { 1623 if (len < tail) 1624 tail = len; 1625 if (dbuf_hold_impl(dn, 0, dbuf_whichblock(dn, 0, off+len), 1626 TRUE, FALSE, FTAG, &db) == 0) { 1627 /* don't dirty if not on disk and not dirty */ 1628 if (db->db_last_dirty || 1629 (db->db_blkptr && !BP_IS_HOLE(db->db_blkptr))) { 1630 rw_exit(&dn->dn_struct_rwlock); 1631 dmu_buf_will_dirty(&db->db, tx); 1632 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 1633 bzero(db->db.db_data, tail); 1634 } 1635 dbuf_rele(db, FTAG); 1636 } 1637 len -= tail; 1638 } 1639 1640 /* If the range did not include a full block, we are done */ 1641 if (len == 0) 1642 goto out; 1643 1644 ASSERT(IS_P2ALIGNED(off, blksz)); 1645 ASSERT(trunc || IS_P2ALIGNED(len, blksz)); 1646 blkid = off >> blkshift; 1647 nblks = len >> blkshift; 1648 if (trunc) 1649 nblks += 1; 1650 1651 /* 1652 * Dirty all the indirect blocks in this range. Note that only 1653 * the first and last indirect blocks can actually be written 1654 * (if they were partially freed) -- they must be dirtied, even if 1655 * they do not exist on disk yet. The interior blocks will 1656 * be freed by free_children(), so they will not actually be written. 1657 * Even though these interior blocks will not be written, we 1658 * dirty them for two reasons: 1659 * 1660 * - It ensures that the indirect blocks remain in memory until 1661 * syncing context. (They have already been prefetched by 1662 * dmu_tx_hold_free(), so we don't have to worry about reading 1663 * them serially here.) 1664 * 1665 * - The dirty space accounting will put pressure on the txg sync 1666 * mechanism to begin syncing, and to delay transactions if there 1667 * is a large amount of freeing. Even though these indirect 1668 * blocks will not be written, we could need to write the same 1669 * amount of space if we copy the freed BPs into deadlists. 1670 */ 1671 if (dn->dn_nlevels > 1) { 1672 uint64_t first, last; 1673 1674 first = blkid >> epbs; 1675 dnode_dirty_l1(dn, first, tx); 1676 if (trunc) 1677 last = dn->dn_maxblkid >> epbs; 1678 else 1679 last = (blkid + nblks - 1) >> epbs; 1680 if (last != first) 1681 dnode_dirty_l1(dn, last, tx); 1682 1683 int shift = dn->dn_datablkshift + dn->dn_indblkshift - 1684 SPA_BLKPTRSHIFT; 1685 for (uint64_t i = first + 1; i < last; i++) { 1686 /* 1687 * Set i to the blockid of the next non-hole 1688 * level-1 indirect block at or after i. Note 1689 * that dnode_next_offset() operates in terms of 1690 * level-0-equivalent bytes. 1691 */ 1692 uint64_t ibyte = i << shift; 1693 int err = dnode_next_offset(dn, DNODE_FIND_HAVELOCK, 1694 &ibyte, 2, 1, 0); 1695 i = ibyte >> shift; 1696 if (i >= last) 1697 break; 1698 1699 /* 1700 * Normally we should not see an error, either 1701 * from dnode_next_offset() or dbuf_hold_level() 1702 * (except for ESRCH from dnode_next_offset). 1703 * If there is an i/o error, then when we read 1704 * this block in syncing context, it will use 1705 * ZIO_FLAG_MUSTSUCCEED, and thus hang/panic according 1706 * to the "failmode" property. dnode_next_offset() 1707 * doesn't have a flag to indicate MUSTSUCCEED. 1708 */ 1709 if (err != 0) 1710 break; 1711 1712 dnode_dirty_l1(dn, i, tx); 1713 } 1714 } 1715 1716done: 1717 /* 1718 * Add this range to the dnode range list. 1719 * We will finish up this free operation in the syncing phase. 1720 */ 1721 mutex_enter(&dn->dn_mtx); 1722 int txgoff = tx->tx_txg & TXG_MASK; 1723 if (dn->dn_free_ranges[txgoff] == NULL) { 1724 dn->dn_free_ranges[txgoff] = 1725 range_tree_create(NULL, NULL, &dn->dn_mtx); 1726 } 1727 range_tree_clear(dn->dn_free_ranges[txgoff], blkid, nblks); 1728 range_tree_add(dn->dn_free_ranges[txgoff], blkid, nblks); 1729 dprintf_dnode(dn, "blkid=%llu nblks=%llu txg=%llu\n", 1730 blkid, nblks, tx->tx_txg); 1731 mutex_exit(&dn->dn_mtx); 1732 1733 dbuf_free_range(dn, blkid, blkid + nblks - 1, tx); 1734 dnode_setdirty(dn, tx); 1735out: 1736 1737 rw_exit(&dn->dn_struct_rwlock); 1738} 1739 1740static boolean_t 1741dnode_spill_freed(dnode_t *dn) 1742{ 1743 int i; 1744 1745 mutex_enter(&dn->dn_mtx); 1746 for (i = 0; i < TXG_SIZE; i++) { 1747 if (dn->dn_rm_spillblk[i] == DN_KILL_SPILLBLK) 1748 break; 1749 } 1750 mutex_exit(&dn->dn_mtx); 1751 return (i < TXG_SIZE); 1752} 1753 1754/* return TRUE if this blkid was freed in a recent txg, or FALSE if it wasn't */ 1755uint64_t 1756dnode_block_freed(dnode_t *dn, uint64_t blkid) 1757{ 1758 void *dp = spa_get_dsl(dn->dn_objset->os_spa); 1759 int i; 1760 1761 if (blkid == DMU_BONUS_BLKID) 1762 return (FALSE); 1763 1764 /* 1765 * If we're in the process of opening the pool, dp will not be 1766 * set yet, but there shouldn't be anything dirty. 1767 */ 1768 if (dp == NULL) 1769 return (FALSE); 1770 1771 if (dn->dn_free_txg) 1772 return (TRUE); 1773 1774 if (blkid == DMU_SPILL_BLKID) 1775 return (dnode_spill_freed(dn)); 1776 1777 mutex_enter(&dn->dn_mtx); 1778 for (i = 0; i < TXG_SIZE; i++) { 1779 if (dn->dn_free_ranges[i] != NULL && 1780 range_tree_contains(dn->dn_free_ranges[i], blkid, 1)) 1781 break; 1782 } 1783 mutex_exit(&dn->dn_mtx); 1784 return (i < TXG_SIZE); 1785} 1786 1787/* call from syncing context when we actually write/free space for this dnode */ 1788void 1789dnode_diduse_space(dnode_t *dn, int64_t delta) 1790{ 1791 uint64_t space; 1792 dprintf_dnode(dn, "dn=%p dnp=%p used=%llu delta=%lld\n", 1793 dn, dn->dn_phys, 1794 (u_longlong_t)dn->dn_phys->dn_used, 1795 (longlong_t)delta); 1796 1797 mutex_enter(&dn->dn_mtx); 1798 space = DN_USED_BYTES(dn->dn_phys); 1799 if (delta > 0) { 1800 ASSERT3U(space + delta, >=, space); /* no overflow */ 1801 } else { 1802 ASSERT3U(space, >=, -delta); /* no underflow */ 1803 } 1804 space += delta; 1805 if (spa_version(dn->dn_objset->os_spa) < SPA_VERSION_DNODE_BYTES) { 1806 ASSERT((dn->dn_phys->dn_flags & DNODE_FLAG_USED_BYTES) == 0); 1807 ASSERT0(P2PHASE(space, 1<<DEV_BSHIFT)); 1808 dn->dn_phys->dn_used = space >> DEV_BSHIFT; 1809 } else { 1810 dn->dn_phys->dn_used = space; 1811 dn->dn_phys->dn_flags |= DNODE_FLAG_USED_BYTES; 1812 } 1813 mutex_exit(&dn->dn_mtx); 1814} 1815 1816/* 1817 * Call when we think we're going to write/free space in open context to track 1818 * the amount of memory in use by the currently open txg. 1819 */ 1820void 1821dnode_willuse_space(dnode_t *dn, int64_t space, dmu_tx_t *tx) 1822{ 1823 objset_t *os = dn->dn_objset; 1824 dsl_dataset_t *ds = os->os_dsl_dataset; 1825 int64_t aspace = spa_get_asize(os->os_spa, space); 1826 1827 if (ds != NULL) { 1828 dsl_dir_willuse_space(ds->ds_dir, aspace, tx); 1829 dsl_pool_dirty_space(dmu_tx_pool(tx), space, tx); 1830 } 1831 1832 dmu_tx_willuse_space(tx, aspace); 1833} 1834 1835/* 1836 * Scans a block at the indicated "level" looking for a hole or data, 1837 * depending on 'flags'. 1838 * 1839 * If level > 0, then we are scanning an indirect block looking at its 1840 * pointers. If level == 0, then we are looking at a block of dnodes. 1841 * 1842 * If we don't find what we are looking for in the block, we return ESRCH. 1843 * Otherwise, return with *offset pointing to the beginning (if searching 1844 * forwards) or end (if searching backwards) of the range covered by the 1845 * block pointer we matched on (or dnode). 1846 * 1847 * The basic search algorithm used below by dnode_next_offset() is to 1848 * use this function to search up the block tree (widen the search) until 1849 * we find something (i.e., we don't return ESRCH) and then search back 1850 * down the tree (narrow the search) until we reach our original search 1851 * level. 1852 */ 1853static int 1854dnode_next_offset_level(dnode_t *dn, int flags, uint64_t *offset, 1855 int lvl, uint64_t blkfill, uint64_t txg) 1856{ 1857 dmu_buf_impl_t *db = NULL; 1858 void *data = NULL; 1859 uint64_t epbs = dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT; 1860 uint64_t epb = 1ULL << epbs; 1861 uint64_t minfill, maxfill; 1862 boolean_t hole; 1863 int i, inc, error, span; 1864 1865 dprintf("probing object %llu offset %llx level %d of %u\n", 1866 dn->dn_object, *offset, lvl, dn->dn_phys->dn_nlevels); 1867 1868 hole = ((flags & DNODE_FIND_HOLE) != 0); 1869 inc = (flags & DNODE_FIND_BACKWARDS) ? -1 : 1; 1870 ASSERT(txg == 0 || !hole); 1871 1872 if (lvl == dn->dn_phys->dn_nlevels) { 1873 error = 0; 1874 epb = dn->dn_phys->dn_nblkptr; 1875 data = dn->dn_phys->dn_blkptr; 1876 } else { 1877 uint64_t blkid = dbuf_whichblock(dn, lvl, *offset); 1878 error = dbuf_hold_impl(dn, lvl, blkid, TRUE, FALSE, FTAG, &db); 1879 if (error) { 1880 if (error != ENOENT) 1881 return (error); 1882 if (hole) 1883 return (0); 1884 /* 1885 * This can only happen when we are searching up 1886 * the block tree for data. We don't really need to 1887 * adjust the offset, as we will just end up looking 1888 * at the pointer to this block in its parent, and its 1889 * going to be unallocated, so we will skip over it. 1890 */ 1891 return (SET_ERROR(ESRCH)); 1892 } 1893 error = dbuf_read(db, NULL, DB_RF_CANFAIL | DB_RF_HAVESTRUCT); 1894 if (error) { 1895 dbuf_rele(db, FTAG); 1896 return (error); 1897 } 1898 data = db->db.db_data; 1899 } 1900 1901 1902 if (db != NULL && txg != 0 && (db->db_blkptr == NULL || 1903 db->db_blkptr->blk_birth <= txg || 1904 BP_IS_HOLE(db->db_blkptr))) { 1905 /* 1906 * This can only happen when we are searching up the tree 1907 * and these conditions mean that we need to keep climbing. 1908 */ 1909 error = SET_ERROR(ESRCH); 1910 } else if (lvl == 0) { 1911 dnode_phys_t *dnp = data; 1912 span = DNODE_SHIFT; 1913 ASSERT(dn->dn_type == DMU_OT_DNODE); 1914 1915 for (i = (*offset >> span) & (blkfill - 1); 1916 i >= 0 && i < blkfill; i += inc) { 1917 if ((dnp[i].dn_type == DMU_OT_NONE) == hole) 1918 break; 1919 *offset += (1ULL << span) * inc; 1920 } 1921 if (i < 0 || i == blkfill) 1922 error = SET_ERROR(ESRCH); 1923 } else { 1924 blkptr_t *bp = data; 1925 uint64_t start = *offset; 1926 span = (lvl - 1) * epbs + dn->dn_datablkshift; 1927 minfill = 0; 1928 maxfill = blkfill << ((lvl - 1) * epbs); 1929 1930 if (hole) 1931 maxfill--; 1932 else 1933 minfill++; 1934 1935 *offset = *offset >> span; 1936 for (i = BF64_GET(*offset, 0, epbs); 1937 i >= 0 && i < epb; i += inc) { 1938 if (BP_GET_FILL(&bp[i]) >= minfill && 1939 BP_GET_FILL(&bp[i]) <= maxfill && 1940 (hole || bp[i].blk_birth > txg)) 1941 break; 1942 if (inc > 0 || *offset > 0) 1943 *offset += inc; 1944 } 1945 *offset = *offset << span; 1946 if (inc < 0) { 1947 /* traversing backwards; position offset at the end */ 1948 ASSERT3U(*offset, <=, start); 1949 *offset = MIN(*offset + (1ULL << span) - 1, start); 1950 } else if (*offset < start) { 1951 *offset = start; 1952 } 1953 if (i < 0 || i >= epb) 1954 error = SET_ERROR(ESRCH); 1955 } 1956 1957 if (db) 1958 dbuf_rele(db, FTAG); 1959 1960 return (error); 1961} 1962 1963/* 1964 * Find the next hole, data, or sparse region at or after *offset. 1965 * The value 'blkfill' tells us how many items we expect to find 1966 * in an L0 data block; this value is 1 for normal objects, 1967 * DNODES_PER_BLOCK for the meta dnode, and some fraction of 1968 * DNODES_PER_BLOCK when searching for sparse regions thereof. 1969 * 1970 * Examples: 1971 * 1972 * dnode_next_offset(dn, flags, offset, 1, 1, 0); 1973 * Finds the next/previous hole/data in a file. 1974 * Used in dmu_offset_next(). 1975 * 1976 * dnode_next_offset(mdn, flags, offset, 0, DNODES_PER_BLOCK, txg); 1977 * Finds the next free/allocated dnode an objset's meta-dnode. 1978 * Only finds objects that have new contents since txg (ie. 1979 * bonus buffer changes and content removal are ignored). 1980 * Used in dmu_object_next(). 1981 * 1982 * dnode_next_offset(mdn, DNODE_FIND_HOLE, offset, 2, DNODES_PER_BLOCK >> 2, 0); 1983 * Finds the next L2 meta-dnode bp that's at most 1/4 full. 1984 * Used in dmu_object_alloc(). 1985 */ 1986int 1987dnode_next_offset(dnode_t *dn, int flags, uint64_t *offset, 1988 int minlvl, uint64_t blkfill, uint64_t txg) 1989{ 1990 uint64_t initial_offset = *offset; 1991 int lvl, maxlvl; 1992 int error = 0; 1993 1994 if (!(flags & DNODE_FIND_HAVELOCK)) 1995 rw_enter(&dn->dn_struct_rwlock, RW_READER); 1996 1997 if (dn->dn_phys->dn_nlevels == 0) { 1998 error = SET_ERROR(ESRCH); 1999 goto out; 2000 } 2001 2002 if (dn->dn_datablkshift == 0) { 2003 if (*offset < dn->dn_datablksz) { 2004 if (flags & DNODE_FIND_HOLE) 2005 *offset = dn->dn_datablksz; 2006 } else { 2007 error = SET_ERROR(ESRCH); 2008 } 2009 goto out; 2010 } 2011 2012 maxlvl = dn->dn_phys->dn_nlevels; 2013 2014 for (lvl = minlvl; lvl <= maxlvl; lvl++) { 2015 error = dnode_next_offset_level(dn, 2016 flags, offset, lvl, blkfill, txg); 2017 if (error != ESRCH) 2018 break; 2019 } 2020 2021 while (error == 0 && --lvl >= minlvl) { 2022 error = dnode_next_offset_level(dn, 2023 flags, offset, lvl, blkfill, txg); 2024 } 2025 2026 /* 2027 * There's always a "virtual hole" at the end of the object, even 2028 * if all BP's which physically exist are non-holes. 2029 */ 2030 if ((flags & DNODE_FIND_HOLE) && error == ESRCH && txg == 0 && 2031 minlvl == 1 && blkfill == 1 && !(flags & DNODE_FIND_BACKWARDS)) { 2032 error = 0; 2033 } 2034 2035 if (error == 0 && (flags & DNODE_FIND_BACKWARDS ? 2036 initial_offset < *offset : initial_offset > *offset)) 2037 error = SET_ERROR(ESRCH); 2038out: 2039 if (!(flags & DNODE_FIND_HAVELOCK)) 2040 rw_exit(&dn->dn_struct_rwlock); 2041 2042 return (error); 2043} 2044