dnode.c revision 268649
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, 2014 by Delphix. All rights reserved. 24 */ 25 26#include <sys/zfs_context.h> 27#include <sys/dbuf.h> 28#include <sys/dnode.h> 29#include <sys/dmu.h> 30#include <sys/dmu_impl.h> 31#include <sys/dmu_tx.h> 32#include <sys/dmu_objset.h> 33#include <sys/dsl_dir.h> 34#include <sys/dsl_dataset.h> 35#include <sys/spa.h> 36#include <sys/zio.h> 37#include <sys/dmu_zfetch.h> 38#include <sys/range_tree.h> 39 40static kmem_cache_t *dnode_cache; 41/* 42 * Define DNODE_STATS to turn on statistic gathering. By default, it is only 43 * turned on when DEBUG is also defined. 44 */ 45#ifdef DEBUG 46#define DNODE_STATS 47#endif /* DEBUG */ 48 49#ifdef DNODE_STATS 50#define DNODE_STAT_ADD(stat) ((stat)++) 51#else 52#define DNODE_STAT_ADD(stat) /* nothing */ 53#endif /* DNODE_STATS */ 54 55static dnode_phys_t dnode_phys_zero; 56 57int zfs_default_bs = SPA_MINBLOCKSHIFT; 58int zfs_default_ibs = DN_MAX_INDBLKSHIFT; 59 60#ifdef sun 61static kmem_cbrc_t dnode_move(void *, void *, size_t, void *); 62#endif 63 64/* ARGSUSED */ 65static int 66dnode_cons(void *arg, void *unused, int kmflag) 67{ 68 dnode_t *dn = arg; 69 int i; 70 71 rw_init(&dn->dn_struct_rwlock, NULL, RW_DEFAULT, NULL); 72 mutex_init(&dn->dn_mtx, NULL, MUTEX_DEFAULT, NULL); 73 mutex_init(&dn->dn_dbufs_mtx, NULL, MUTEX_DEFAULT, NULL); 74 cv_init(&dn->dn_notxholds, NULL, CV_DEFAULT, NULL); 75 76 /* 77 * Every dbuf has a reference, and dropping a tracked reference is 78 * O(number of references), so don't track dn_holds. 79 */ 80 refcount_create_untracked(&dn->dn_holds); 81 refcount_create(&dn->dn_tx_holds); 82 list_link_init(&dn->dn_link); 83 84 bzero(&dn->dn_next_nblkptr[0], sizeof (dn->dn_next_nblkptr)); 85 bzero(&dn->dn_next_nlevels[0], sizeof (dn->dn_next_nlevels)); 86 bzero(&dn->dn_next_indblkshift[0], sizeof (dn->dn_next_indblkshift)); 87 bzero(&dn->dn_next_bonustype[0], sizeof (dn->dn_next_bonustype)); 88 bzero(&dn->dn_rm_spillblk[0], sizeof (dn->dn_rm_spillblk)); 89 bzero(&dn->dn_next_bonuslen[0], sizeof (dn->dn_next_bonuslen)); 90 bzero(&dn->dn_next_blksz[0], sizeof (dn->dn_next_blksz)); 91 92 for (i = 0; i < TXG_SIZE; i++) { 93 list_link_init(&dn->dn_dirty_link[i]); 94 dn->dn_free_ranges[i] = NULL; 95 list_create(&dn->dn_dirty_records[i], 96 sizeof (dbuf_dirty_record_t), 97 offsetof(dbuf_dirty_record_t, dr_dirty_node)); 98 } 99 100 dn->dn_allocated_txg = 0; 101 dn->dn_free_txg = 0; 102 dn->dn_assigned_txg = 0; 103 dn->dn_dirtyctx = 0; 104 dn->dn_dirtyctx_firstset = NULL; 105 dn->dn_bonus = NULL; 106 dn->dn_have_spill = B_FALSE; 107 dn->dn_zio = NULL; 108 dn->dn_oldused = 0; 109 dn->dn_oldflags = 0; 110 dn->dn_olduid = 0; 111 dn->dn_oldgid = 0; 112 dn->dn_newuid = 0; 113 dn->dn_newgid = 0; 114 dn->dn_id_flags = 0; 115 116 dn->dn_dbufs_count = 0; 117 dn->dn_unlisted_l0_blkid = 0; 118 list_create(&dn->dn_dbufs, sizeof (dmu_buf_impl_t), 119 offsetof(dmu_buf_impl_t, db_link)); 120 121 dn->dn_moved = 0; 122 POINTER_INVALIDATE(&dn->dn_objset); 123 return (0); 124} 125 126/* ARGSUSED */ 127static void 128dnode_dest(void *arg, void *unused) 129{ 130 int i; 131 dnode_t *dn = arg; 132 133 rw_destroy(&dn->dn_struct_rwlock); 134 mutex_destroy(&dn->dn_mtx); 135 mutex_destroy(&dn->dn_dbufs_mtx); 136 cv_destroy(&dn->dn_notxholds); 137 refcount_destroy(&dn->dn_holds); 138 refcount_destroy(&dn->dn_tx_holds); 139 ASSERT(!list_link_active(&dn->dn_link)); 140 141 for (i = 0; i < TXG_SIZE; i++) { 142 ASSERT(!list_link_active(&dn->dn_dirty_link[i])); 143 ASSERT3P(dn->dn_free_ranges[i], ==, NULL); 144 list_destroy(&dn->dn_dirty_records[i]); 145 ASSERT0(dn->dn_next_nblkptr[i]); 146 ASSERT0(dn->dn_next_nlevels[i]); 147 ASSERT0(dn->dn_next_indblkshift[i]); 148 ASSERT0(dn->dn_next_bonustype[i]); 149 ASSERT0(dn->dn_rm_spillblk[i]); 150 ASSERT0(dn->dn_next_bonuslen[i]); 151 ASSERT0(dn->dn_next_blksz[i]); 152 } 153 154 ASSERT0(dn->dn_allocated_txg); 155 ASSERT0(dn->dn_free_txg); 156 ASSERT0(dn->dn_assigned_txg); 157 ASSERT0(dn->dn_dirtyctx); 158 ASSERT3P(dn->dn_dirtyctx_firstset, ==, NULL); 159 ASSERT3P(dn->dn_bonus, ==, NULL); 160 ASSERT(!dn->dn_have_spill); 161 ASSERT3P(dn->dn_zio, ==, NULL); 162 ASSERT0(dn->dn_oldused); 163 ASSERT0(dn->dn_oldflags); 164 ASSERT0(dn->dn_olduid); 165 ASSERT0(dn->dn_oldgid); 166 ASSERT0(dn->dn_newuid); 167 ASSERT0(dn->dn_newgid); 168 ASSERT0(dn->dn_id_flags); 169 170 ASSERT0(dn->dn_dbufs_count); 171 ASSERT0(dn->dn_unlisted_l0_blkid); 172 list_destroy(&dn->dn_dbufs); 173} 174 175void 176dnode_init(void) 177{ 178 ASSERT(dnode_cache == NULL); 179 dnode_cache = kmem_cache_create("dnode_t", 180 sizeof (dnode_t), 181 0, dnode_cons, dnode_dest, NULL, NULL, NULL, 0); 182 kmem_cache_set_move(dnode_cache, dnode_move); 183} 184 185void 186dnode_fini(void) 187{ 188 kmem_cache_destroy(dnode_cache); 189 dnode_cache = NULL; 190} 191 192 193#ifdef ZFS_DEBUG 194void 195dnode_verify(dnode_t *dn) 196{ 197 int drop_struct_lock = FALSE; 198 199 ASSERT(dn->dn_phys); 200 ASSERT(dn->dn_objset); 201 ASSERT(dn->dn_handle->dnh_dnode == dn); 202 203 ASSERT(DMU_OT_IS_VALID(dn->dn_phys->dn_type)); 204 205 if (!(zfs_flags & ZFS_DEBUG_DNODE_VERIFY)) 206 return; 207 208 if (!RW_WRITE_HELD(&dn->dn_struct_rwlock)) { 209 rw_enter(&dn->dn_struct_rwlock, RW_READER); 210 drop_struct_lock = TRUE; 211 } 212 if (dn->dn_phys->dn_type != DMU_OT_NONE || dn->dn_allocated_txg != 0) { 213 int i; 214 ASSERT3U(dn->dn_indblkshift, >=, 0); 215 ASSERT3U(dn->dn_indblkshift, <=, SPA_MAXBLOCKSHIFT); 216 if (dn->dn_datablkshift) { 217 ASSERT3U(dn->dn_datablkshift, >=, SPA_MINBLOCKSHIFT); 218 ASSERT3U(dn->dn_datablkshift, <=, SPA_MAXBLOCKSHIFT); 219 ASSERT3U(1<<dn->dn_datablkshift, ==, dn->dn_datablksz); 220 } 221 ASSERT3U(dn->dn_nlevels, <=, 30); 222 ASSERT(DMU_OT_IS_VALID(dn->dn_type)); 223 ASSERT3U(dn->dn_nblkptr, >=, 1); 224 ASSERT3U(dn->dn_nblkptr, <=, DN_MAX_NBLKPTR); 225 ASSERT3U(dn->dn_bonuslen, <=, DN_MAX_BONUSLEN); 226 ASSERT3U(dn->dn_datablksz, ==, 227 dn->dn_datablkszsec << SPA_MINBLOCKSHIFT); 228 ASSERT3U(ISP2(dn->dn_datablksz), ==, dn->dn_datablkshift != 0); 229 ASSERT3U((dn->dn_nblkptr - 1) * sizeof (blkptr_t) + 230 dn->dn_bonuslen, <=, DN_MAX_BONUSLEN); 231 for (i = 0; i < TXG_SIZE; i++) { 232 ASSERT3U(dn->dn_next_nlevels[i], <=, dn->dn_nlevels); 233 } 234 } 235 if (dn->dn_phys->dn_type != DMU_OT_NONE) 236 ASSERT3U(dn->dn_phys->dn_nlevels, <=, dn->dn_nlevels); 237 ASSERT(DMU_OBJECT_IS_SPECIAL(dn->dn_object) || dn->dn_dbuf != NULL); 238 if (dn->dn_dbuf != NULL) { 239 ASSERT3P(dn->dn_phys, ==, 240 (dnode_phys_t *)dn->dn_dbuf->db.db_data + 241 (dn->dn_object % (dn->dn_dbuf->db.db_size >> DNODE_SHIFT))); 242 } 243 if (drop_struct_lock) 244 rw_exit(&dn->dn_struct_rwlock); 245} 246#endif 247 248void 249dnode_byteswap(dnode_phys_t *dnp) 250{ 251 uint64_t *buf64 = (void*)&dnp->dn_blkptr; 252 int i; 253 254 if (dnp->dn_type == DMU_OT_NONE) { 255 bzero(dnp, sizeof (dnode_phys_t)); 256 return; 257 } 258 259 dnp->dn_datablkszsec = BSWAP_16(dnp->dn_datablkszsec); 260 dnp->dn_bonuslen = BSWAP_16(dnp->dn_bonuslen); 261 dnp->dn_maxblkid = BSWAP_64(dnp->dn_maxblkid); 262 dnp->dn_used = BSWAP_64(dnp->dn_used); 263 264 /* 265 * dn_nblkptr is only one byte, so it's OK to read it in either 266 * byte order. We can't read dn_bouslen. 267 */ 268 ASSERT(dnp->dn_indblkshift <= SPA_MAXBLOCKSHIFT); 269 ASSERT(dnp->dn_nblkptr <= DN_MAX_NBLKPTR); 270 for (i = 0; i < dnp->dn_nblkptr * sizeof (blkptr_t)/8; i++) 271 buf64[i] = BSWAP_64(buf64[i]); 272 273 /* 274 * OK to check dn_bonuslen for zero, because it won't matter if 275 * we have the wrong byte order. This is necessary because the 276 * dnode dnode is smaller than a regular dnode. 277 */ 278 if (dnp->dn_bonuslen != 0) { 279 /* 280 * Note that the bonus length calculated here may be 281 * longer than the actual bonus buffer. This is because 282 * we always put the bonus buffer after the last block 283 * pointer (instead of packing it against the end of the 284 * dnode buffer). 285 */ 286 int off = (dnp->dn_nblkptr-1) * sizeof (blkptr_t); 287 size_t len = DN_MAX_BONUSLEN - off; 288 ASSERT(DMU_OT_IS_VALID(dnp->dn_bonustype)); 289 dmu_object_byteswap_t byteswap = 290 DMU_OT_BYTESWAP(dnp->dn_bonustype); 291 dmu_ot_byteswap[byteswap].ob_func(dnp->dn_bonus + off, len); 292 } 293 294 /* Swap SPILL block if we have one */ 295 if (dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) 296 byteswap_uint64_array(&dnp->dn_spill, sizeof (blkptr_t)); 297 298} 299 300void 301dnode_buf_byteswap(void *vbuf, size_t size) 302{ 303 dnode_phys_t *buf = vbuf; 304 int i; 305 306 ASSERT3U(sizeof (dnode_phys_t), ==, (1<<DNODE_SHIFT)); 307 ASSERT((size & (sizeof (dnode_phys_t)-1)) == 0); 308 309 size >>= DNODE_SHIFT; 310 for (i = 0; i < size; i++) { 311 dnode_byteswap(buf); 312 buf++; 313 } 314} 315 316void 317dnode_setbonuslen(dnode_t *dn, int newsize, dmu_tx_t *tx) 318{ 319 ASSERT3U(refcount_count(&dn->dn_holds), >=, 1); 320 321 dnode_setdirty(dn, tx); 322 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 323 ASSERT3U(newsize, <=, DN_MAX_BONUSLEN - 324 (dn->dn_nblkptr-1) * sizeof (blkptr_t)); 325 dn->dn_bonuslen = newsize; 326 if (newsize == 0) 327 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = DN_ZERO_BONUSLEN; 328 else 329 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = dn->dn_bonuslen; 330 rw_exit(&dn->dn_struct_rwlock); 331} 332 333void 334dnode_setbonus_type(dnode_t *dn, dmu_object_type_t newtype, dmu_tx_t *tx) 335{ 336 ASSERT3U(refcount_count(&dn->dn_holds), >=, 1); 337 dnode_setdirty(dn, tx); 338 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 339 dn->dn_bonustype = newtype; 340 dn->dn_next_bonustype[tx->tx_txg & TXG_MASK] = dn->dn_bonustype; 341 rw_exit(&dn->dn_struct_rwlock); 342} 343 344void 345dnode_rm_spill(dnode_t *dn, dmu_tx_t *tx) 346{ 347 ASSERT3U(refcount_count(&dn->dn_holds), >=, 1); 348 ASSERT(RW_WRITE_HELD(&dn->dn_struct_rwlock)); 349 dnode_setdirty(dn, tx); 350 dn->dn_rm_spillblk[tx->tx_txg&TXG_MASK] = DN_KILL_SPILLBLK; 351 dn->dn_have_spill = B_FALSE; 352} 353 354static void 355dnode_setdblksz(dnode_t *dn, int size) 356{ 357 ASSERT0(P2PHASE(size, SPA_MINBLOCKSIZE)); 358 ASSERT3U(size, <=, SPA_MAXBLOCKSIZE); 359 ASSERT3U(size, >=, SPA_MINBLOCKSIZE); 360 ASSERT3U(size >> SPA_MINBLOCKSHIFT, <, 361 1<<(sizeof (dn->dn_phys->dn_datablkszsec) * 8)); 362 dn->dn_datablksz = size; 363 dn->dn_datablkszsec = size >> SPA_MINBLOCKSHIFT; 364 dn->dn_datablkshift = ISP2(size) ? highbit64(size - 1) : 0; 365} 366 367static dnode_t * 368dnode_create(objset_t *os, dnode_phys_t *dnp, dmu_buf_impl_t *db, 369 uint64_t object, dnode_handle_t *dnh) 370{ 371 dnode_t *dn = kmem_cache_alloc(dnode_cache, KM_SLEEP); 372 373 ASSERT(!POINTER_IS_VALID(dn->dn_objset)); 374 dn->dn_moved = 0; 375 376 /* 377 * Defer setting dn_objset until the dnode is ready to be a candidate 378 * for the dnode_move() callback. 379 */ 380 dn->dn_object = object; 381 dn->dn_dbuf = db; 382 dn->dn_handle = dnh; 383 dn->dn_phys = dnp; 384 385 if (dnp->dn_datablkszsec) { 386 dnode_setdblksz(dn, dnp->dn_datablkszsec << SPA_MINBLOCKSHIFT); 387 } else { 388 dn->dn_datablksz = 0; 389 dn->dn_datablkszsec = 0; 390 dn->dn_datablkshift = 0; 391 } 392 dn->dn_indblkshift = dnp->dn_indblkshift; 393 dn->dn_nlevels = dnp->dn_nlevels; 394 dn->dn_type = dnp->dn_type; 395 dn->dn_nblkptr = dnp->dn_nblkptr; 396 dn->dn_checksum = dnp->dn_checksum; 397 dn->dn_compress = dnp->dn_compress; 398 dn->dn_bonustype = dnp->dn_bonustype; 399 dn->dn_bonuslen = dnp->dn_bonuslen; 400 dn->dn_maxblkid = dnp->dn_maxblkid; 401 dn->dn_have_spill = ((dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) != 0); 402 dn->dn_id_flags = 0; 403 404 dmu_zfetch_init(&dn->dn_zfetch, dn); 405 406 ASSERT(DMU_OT_IS_VALID(dn->dn_phys->dn_type)); 407 408 mutex_enter(&os->os_lock); 409 list_insert_head(&os->os_dnodes, dn); 410 membar_producer(); 411 /* 412 * Everything else must be valid before assigning dn_objset makes the 413 * dnode eligible for dnode_move(). 414 */ 415 dn->dn_objset = os; 416 mutex_exit(&os->os_lock); 417 418 arc_space_consume(sizeof (dnode_t), ARC_SPACE_OTHER); 419 return (dn); 420} 421 422/* 423 * Caller must be holding the dnode handle, which is released upon return. 424 */ 425static void 426dnode_destroy(dnode_t *dn) 427{ 428 objset_t *os = dn->dn_objset; 429 430 ASSERT((dn->dn_id_flags & DN_ID_NEW_EXIST) == 0); 431 432 mutex_enter(&os->os_lock); 433 POINTER_INVALIDATE(&dn->dn_objset); 434 list_remove(&os->os_dnodes, dn); 435 mutex_exit(&os->os_lock); 436 437 /* the dnode can no longer move, so we can release the handle */ 438 zrl_remove(&dn->dn_handle->dnh_zrlock); 439 440 dn->dn_allocated_txg = 0; 441 dn->dn_free_txg = 0; 442 dn->dn_assigned_txg = 0; 443 444 dn->dn_dirtyctx = 0; 445 if (dn->dn_dirtyctx_firstset != NULL) { 446 kmem_free(dn->dn_dirtyctx_firstset, 1); 447 dn->dn_dirtyctx_firstset = NULL; 448 } 449 if (dn->dn_bonus != NULL) { 450 mutex_enter(&dn->dn_bonus->db_mtx); 451 dbuf_evict(dn->dn_bonus); 452 dn->dn_bonus = NULL; 453 } 454 dn->dn_zio = NULL; 455 456 dn->dn_have_spill = B_FALSE; 457 dn->dn_oldused = 0; 458 dn->dn_oldflags = 0; 459 dn->dn_olduid = 0; 460 dn->dn_oldgid = 0; 461 dn->dn_newuid = 0; 462 dn->dn_newgid = 0; 463 dn->dn_id_flags = 0; 464 dn->dn_unlisted_l0_blkid = 0; 465 466 dmu_zfetch_rele(&dn->dn_zfetch); 467 kmem_cache_free(dnode_cache, dn); 468 arc_space_return(sizeof (dnode_t), ARC_SPACE_OTHER); 469} 470 471void 472dnode_allocate(dnode_t *dn, dmu_object_type_t ot, int blocksize, int ibs, 473 dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx) 474{ 475 int i; 476 477 if (blocksize == 0) 478 blocksize = 1 << zfs_default_bs; 479 else if (blocksize > SPA_MAXBLOCKSIZE) 480 blocksize = SPA_MAXBLOCKSIZE; 481 else 482 blocksize = P2ROUNDUP(blocksize, SPA_MINBLOCKSIZE); 483 484 if (ibs == 0) 485 ibs = zfs_default_ibs; 486 487 ibs = MIN(MAX(ibs, DN_MIN_INDBLKSHIFT), DN_MAX_INDBLKSHIFT); 488 489 dprintf("os=%p obj=%llu txg=%llu blocksize=%d ibs=%d\n", dn->dn_objset, 490 dn->dn_object, tx->tx_txg, blocksize, ibs); 491 492 ASSERT(dn->dn_type == DMU_OT_NONE); 493 ASSERT(bcmp(dn->dn_phys, &dnode_phys_zero, sizeof (dnode_phys_t)) == 0); 494 ASSERT(dn->dn_phys->dn_type == DMU_OT_NONE); 495 ASSERT(ot != DMU_OT_NONE); 496 ASSERT(DMU_OT_IS_VALID(ot)); 497 ASSERT((bonustype == DMU_OT_NONE && bonuslen == 0) || 498 (bonustype == DMU_OT_SA && bonuslen == 0) || 499 (bonustype != DMU_OT_NONE && bonuslen != 0)); 500 ASSERT(DMU_OT_IS_VALID(bonustype)); 501 ASSERT3U(bonuslen, <=, DN_MAX_BONUSLEN); 502 ASSERT(dn->dn_type == DMU_OT_NONE); 503 ASSERT0(dn->dn_maxblkid); 504 ASSERT0(dn->dn_allocated_txg); 505 ASSERT0(dn->dn_assigned_txg); 506 ASSERT(refcount_is_zero(&dn->dn_tx_holds)); 507 ASSERT3U(refcount_count(&dn->dn_holds), <=, 1); 508 ASSERT3P(list_head(&dn->dn_dbufs), ==, NULL); 509 510 for (i = 0; i < TXG_SIZE; i++) { 511 ASSERT0(dn->dn_next_nblkptr[i]); 512 ASSERT0(dn->dn_next_nlevels[i]); 513 ASSERT0(dn->dn_next_indblkshift[i]); 514 ASSERT0(dn->dn_next_bonuslen[i]); 515 ASSERT0(dn->dn_next_bonustype[i]); 516 ASSERT0(dn->dn_rm_spillblk[i]); 517 ASSERT0(dn->dn_next_blksz[i]); 518 ASSERT(!list_link_active(&dn->dn_dirty_link[i])); 519 ASSERT3P(list_head(&dn->dn_dirty_records[i]), ==, NULL); 520 ASSERT3P(dn->dn_free_ranges[i], ==, NULL); 521 } 522 523 dn->dn_type = ot; 524 dnode_setdblksz(dn, blocksize); 525 dn->dn_indblkshift = ibs; 526 dn->dn_nlevels = 1; 527 if (bonustype == DMU_OT_SA) /* Maximize bonus space for SA */ 528 dn->dn_nblkptr = 1; 529 else 530 dn->dn_nblkptr = 1 + 531 ((DN_MAX_BONUSLEN - bonuslen) >> SPA_BLKPTRSHIFT); 532 dn->dn_bonustype = bonustype; 533 dn->dn_bonuslen = bonuslen; 534 dn->dn_checksum = ZIO_CHECKSUM_INHERIT; 535 dn->dn_compress = ZIO_COMPRESS_INHERIT; 536 dn->dn_dirtyctx = 0; 537 538 dn->dn_free_txg = 0; 539 if (dn->dn_dirtyctx_firstset) { 540 kmem_free(dn->dn_dirtyctx_firstset, 1); 541 dn->dn_dirtyctx_firstset = NULL; 542 } 543 544 dn->dn_allocated_txg = tx->tx_txg; 545 dn->dn_id_flags = 0; 546 547 dnode_setdirty(dn, tx); 548 dn->dn_next_indblkshift[tx->tx_txg & TXG_MASK] = ibs; 549 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = dn->dn_bonuslen; 550 dn->dn_next_bonustype[tx->tx_txg & TXG_MASK] = dn->dn_bonustype; 551 dn->dn_next_blksz[tx->tx_txg & TXG_MASK] = dn->dn_datablksz; 552} 553 554void 555dnode_reallocate(dnode_t *dn, dmu_object_type_t ot, int blocksize, 556 dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx) 557{ 558 int nblkptr; 559 560 ASSERT3U(blocksize, >=, SPA_MINBLOCKSIZE); 561 ASSERT3U(blocksize, <=, SPA_MAXBLOCKSIZE); 562 ASSERT0(blocksize % SPA_MINBLOCKSIZE); 563 ASSERT(dn->dn_object != DMU_META_DNODE_OBJECT || dmu_tx_private_ok(tx)); 564 ASSERT(tx->tx_txg != 0); 565 ASSERT((bonustype == DMU_OT_NONE && bonuslen == 0) || 566 (bonustype != DMU_OT_NONE && bonuslen != 0) || 567 (bonustype == DMU_OT_SA && bonuslen == 0)); 568 ASSERT(DMU_OT_IS_VALID(bonustype)); 569 ASSERT3U(bonuslen, <=, DN_MAX_BONUSLEN); 570 571 /* clean up any unreferenced dbufs */ 572 dnode_evict_dbufs(dn); 573 574 dn->dn_id_flags = 0; 575 576 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 577 dnode_setdirty(dn, tx); 578 if (dn->dn_datablksz != blocksize) { 579 /* change blocksize */ 580 ASSERT(dn->dn_maxblkid == 0 && 581 (BP_IS_HOLE(&dn->dn_phys->dn_blkptr[0]) || 582 dnode_block_freed(dn, 0))); 583 dnode_setdblksz(dn, blocksize); 584 dn->dn_next_blksz[tx->tx_txg&TXG_MASK] = blocksize; 585 } 586 if (dn->dn_bonuslen != bonuslen) 587 dn->dn_next_bonuslen[tx->tx_txg&TXG_MASK] = bonuslen; 588 589 if (bonustype == DMU_OT_SA) /* Maximize bonus space for SA */ 590 nblkptr = 1; 591 else 592 nblkptr = 1 + ((DN_MAX_BONUSLEN - bonuslen) >> SPA_BLKPTRSHIFT); 593 if (dn->dn_bonustype != bonustype) 594 dn->dn_next_bonustype[tx->tx_txg&TXG_MASK] = bonustype; 595 if (dn->dn_nblkptr != nblkptr) 596 dn->dn_next_nblkptr[tx->tx_txg&TXG_MASK] = nblkptr; 597 if (dn->dn_phys->dn_flags & DNODE_FLAG_SPILL_BLKPTR) { 598 dbuf_rm_spill(dn, tx); 599 dnode_rm_spill(dn, tx); 600 } 601 rw_exit(&dn->dn_struct_rwlock); 602 603 /* change type */ 604 dn->dn_type = ot; 605 606 /* change bonus size and type */ 607 mutex_enter(&dn->dn_mtx); 608 dn->dn_bonustype = bonustype; 609 dn->dn_bonuslen = bonuslen; 610 dn->dn_nblkptr = nblkptr; 611 dn->dn_checksum = ZIO_CHECKSUM_INHERIT; 612 dn->dn_compress = ZIO_COMPRESS_INHERIT; 613 ASSERT3U(dn->dn_nblkptr, <=, DN_MAX_NBLKPTR); 614 615 /* fix up the bonus db_size */ 616 if (dn->dn_bonus) { 617 dn->dn_bonus->db.db_size = 618 DN_MAX_BONUSLEN - (dn->dn_nblkptr-1) * sizeof (blkptr_t); 619 ASSERT(dn->dn_bonuslen <= dn->dn_bonus->db.db_size); 620 } 621 622 dn->dn_allocated_txg = tx->tx_txg; 623 mutex_exit(&dn->dn_mtx); 624} 625 626#ifdef DNODE_STATS 627static struct { 628 uint64_t dms_dnode_invalid; 629 uint64_t dms_dnode_recheck1; 630 uint64_t dms_dnode_recheck2; 631 uint64_t dms_dnode_special; 632 uint64_t dms_dnode_handle; 633 uint64_t dms_dnode_rwlock; 634 uint64_t dms_dnode_active; 635} dnode_move_stats; 636#endif /* DNODE_STATS */ 637 638static void 639dnode_move_impl(dnode_t *odn, dnode_t *ndn) 640{ 641 int i; 642 643 ASSERT(!RW_LOCK_HELD(&odn->dn_struct_rwlock)); 644 ASSERT(MUTEX_NOT_HELD(&odn->dn_mtx)); 645 ASSERT(MUTEX_NOT_HELD(&odn->dn_dbufs_mtx)); 646 ASSERT(!RW_LOCK_HELD(&odn->dn_zfetch.zf_rwlock)); 647 648 /* Copy fields. */ 649 ndn->dn_objset = odn->dn_objset; 650 ndn->dn_object = odn->dn_object; 651 ndn->dn_dbuf = odn->dn_dbuf; 652 ndn->dn_handle = odn->dn_handle; 653 ndn->dn_phys = odn->dn_phys; 654 ndn->dn_type = odn->dn_type; 655 ndn->dn_bonuslen = odn->dn_bonuslen; 656 ndn->dn_bonustype = odn->dn_bonustype; 657 ndn->dn_nblkptr = odn->dn_nblkptr; 658 ndn->dn_checksum = odn->dn_checksum; 659 ndn->dn_compress = odn->dn_compress; 660 ndn->dn_nlevels = odn->dn_nlevels; 661 ndn->dn_indblkshift = odn->dn_indblkshift; 662 ndn->dn_datablkshift = odn->dn_datablkshift; 663 ndn->dn_datablkszsec = odn->dn_datablkszsec; 664 ndn->dn_datablksz = odn->dn_datablksz; 665 ndn->dn_maxblkid = odn->dn_maxblkid; 666 bcopy(&odn->dn_next_nblkptr[0], &ndn->dn_next_nblkptr[0], 667 sizeof (odn->dn_next_nblkptr)); 668 bcopy(&odn->dn_next_nlevels[0], &ndn->dn_next_nlevels[0], 669 sizeof (odn->dn_next_nlevels)); 670 bcopy(&odn->dn_next_indblkshift[0], &ndn->dn_next_indblkshift[0], 671 sizeof (odn->dn_next_indblkshift)); 672 bcopy(&odn->dn_next_bonustype[0], &ndn->dn_next_bonustype[0], 673 sizeof (odn->dn_next_bonustype)); 674 bcopy(&odn->dn_rm_spillblk[0], &ndn->dn_rm_spillblk[0], 675 sizeof (odn->dn_rm_spillblk)); 676 bcopy(&odn->dn_next_bonuslen[0], &ndn->dn_next_bonuslen[0], 677 sizeof (odn->dn_next_bonuslen)); 678 bcopy(&odn->dn_next_blksz[0], &ndn->dn_next_blksz[0], 679 sizeof (odn->dn_next_blksz)); 680 for (i = 0; i < TXG_SIZE; i++) { 681 list_move_tail(&ndn->dn_dirty_records[i], 682 &odn->dn_dirty_records[i]); 683 } 684 bcopy(&odn->dn_free_ranges[0], &ndn->dn_free_ranges[0], 685 sizeof (odn->dn_free_ranges)); 686 ndn->dn_allocated_txg = odn->dn_allocated_txg; 687 ndn->dn_free_txg = odn->dn_free_txg; 688 ndn->dn_assigned_txg = odn->dn_assigned_txg; 689 ndn->dn_dirtyctx = odn->dn_dirtyctx; 690 ndn->dn_dirtyctx_firstset = odn->dn_dirtyctx_firstset; 691 ASSERT(refcount_count(&odn->dn_tx_holds) == 0); 692 refcount_transfer(&ndn->dn_holds, &odn->dn_holds); 693 ASSERT(list_is_empty(&ndn->dn_dbufs)); 694 list_move_tail(&ndn->dn_dbufs, &odn->dn_dbufs); 695 ndn->dn_dbufs_count = odn->dn_dbufs_count; 696 ndn->dn_unlisted_l0_blkid = odn->dn_unlisted_l0_blkid; 697 ndn->dn_bonus = odn->dn_bonus; 698 ndn->dn_have_spill = odn->dn_have_spill; 699 ndn->dn_zio = odn->dn_zio; 700 ndn->dn_oldused = odn->dn_oldused; 701 ndn->dn_oldflags = odn->dn_oldflags; 702 ndn->dn_olduid = odn->dn_olduid; 703 ndn->dn_oldgid = odn->dn_oldgid; 704 ndn->dn_newuid = odn->dn_newuid; 705 ndn->dn_newgid = odn->dn_newgid; 706 ndn->dn_id_flags = odn->dn_id_flags; 707 dmu_zfetch_init(&ndn->dn_zfetch, NULL); 708 list_move_tail(&ndn->dn_zfetch.zf_stream, &odn->dn_zfetch.zf_stream); 709 ndn->dn_zfetch.zf_dnode = odn->dn_zfetch.zf_dnode; 710 ndn->dn_zfetch.zf_stream_cnt = odn->dn_zfetch.zf_stream_cnt; 711 ndn->dn_zfetch.zf_alloc_fail = odn->dn_zfetch.zf_alloc_fail; 712 713 /* 714 * Update back pointers. Updating the handle fixes the back pointer of 715 * every descendant dbuf as well as the bonus dbuf. 716 */ 717 ASSERT(ndn->dn_handle->dnh_dnode == odn); 718 ndn->dn_handle->dnh_dnode = ndn; 719 if (ndn->dn_zfetch.zf_dnode == odn) { 720 ndn->dn_zfetch.zf_dnode = ndn; 721 } 722 723 /* 724 * Invalidate the original dnode by clearing all of its back pointers. 725 */ 726 odn->dn_dbuf = NULL; 727 odn->dn_handle = NULL; 728 list_create(&odn->dn_dbufs, sizeof (dmu_buf_impl_t), 729 offsetof(dmu_buf_impl_t, db_link)); 730 odn->dn_dbufs_count = 0; 731 odn->dn_unlisted_l0_blkid = 0; 732 odn->dn_bonus = NULL; 733 odn->dn_zfetch.zf_dnode = NULL; 734 735 /* 736 * Set the low bit of the objset pointer to ensure that dnode_move() 737 * recognizes the dnode as invalid in any subsequent callback. 738 */ 739 POINTER_INVALIDATE(&odn->dn_objset); 740 741 /* 742 * Satisfy the destructor. 743 */ 744 for (i = 0; i < TXG_SIZE; i++) { 745 list_create(&odn->dn_dirty_records[i], 746 sizeof (dbuf_dirty_record_t), 747 offsetof(dbuf_dirty_record_t, dr_dirty_node)); 748 odn->dn_free_ranges[i] = NULL; 749 odn->dn_next_nlevels[i] = 0; 750 odn->dn_next_indblkshift[i] = 0; 751 odn->dn_next_bonustype[i] = 0; 752 odn->dn_rm_spillblk[i] = 0; 753 odn->dn_next_bonuslen[i] = 0; 754 odn->dn_next_blksz[i] = 0; 755 } 756 odn->dn_allocated_txg = 0; 757 odn->dn_free_txg = 0; 758 odn->dn_assigned_txg = 0; 759 odn->dn_dirtyctx = 0; 760 odn->dn_dirtyctx_firstset = NULL; 761 odn->dn_have_spill = B_FALSE; 762 odn->dn_zio = NULL; 763 odn->dn_oldused = 0; 764 odn->dn_oldflags = 0; 765 odn->dn_olduid = 0; 766 odn->dn_oldgid = 0; 767 odn->dn_newuid = 0; 768 odn->dn_newgid = 0; 769 odn->dn_id_flags = 0; 770 771 /* 772 * Mark the dnode. 773 */ 774 ndn->dn_moved = 1; 775 odn->dn_moved = (uint8_t)-1; 776} 777 778#ifdef sun 779#ifdef _KERNEL 780/*ARGSUSED*/ 781static kmem_cbrc_t 782dnode_move(void *buf, void *newbuf, size_t size, void *arg) 783{ 784 dnode_t *odn = buf, *ndn = newbuf; 785 objset_t *os; 786 int64_t refcount; 787 uint32_t dbufs; 788 789 /* 790 * The dnode is on the objset's list of known dnodes if the objset 791 * pointer is valid. We set the low bit of the objset pointer when 792 * freeing the dnode to invalidate it, and the memory patterns written 793 * by kmem (baddcafe and deadbeef) set at least one of the two low bits. 794 * A newly created dnode sets the objset pointer last of all to indicate 795 * that the dnode is known and in a valid state to be moved by this 796 * function. 797 */ 798 os = odn->dn_objset; 799 if (!POINTER_IS_VALID(os)) { 800 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_invalid); 801 return (KMEM_CBRC_DONT_KNOW); 802 } 803 804 /* 805 * Ensure that the objset does not go away during the move. 806 */ 807 rw_enter(&os_lock, RW_WRITER); 808 if (os != odn->dn_objset) { 809 rw_exit(&os_lock); 810 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_recheck1); 811 return (KMEM_CBRC_DONT_KNOW); 812 } 813 814 /* 815 * If the dnode is still valid, then so is the objset. We know that no 816 * valid objset can be freed while we hold os_lock, so we can safely 817 * ensure that the objset remains in use. 818 */ 819 mutex_enter(&os->os_lock); 820 821 /* 822 * Recheck the objset pointer in case the dnode was removed just before 823 * acquiring the lock. 824 */ 825 if (os != odn->dn_objset) { 826 mutex_exit(&os->os_lock); 827 rw_exit(&os_lock); 828 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_recheck2); 829 return (KMEM_CBRC_DONT_KNOW); 830 } 831 832 /* 833 * At this point we know that as long as we hold os->os_lock, the dnode 834 * cannot be freed and fields within the dnode can be safely accessed. 835 * The objset listing this dnode cannot go away as long as this dnode is 836 * on its list. 837 */ 838 rw_exit(&os_lock); 839 if (DMU_OBJECT_IS_SPECIAL(odn->dn_object)) { 840 mutex_exit(&os->os_lock); 841 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_special); 842 return (KMEM_CBRC_NO); 843 } 844 ASSERT(odn->dn_dbuf != NULL); /* only "special" dnodes have no parent */ 845 846 /* 847 * Lock the dnode handle to prevent the dnode from obtaining any new 848 * holds. This also prevents the descendant dbufs and the bonus dbuf 849 * from accessing the dnode, so that we can discount their holds. The 850 * handle is safe to access because we know that while the dnode cannot 851 * go away, neither can its handle. Once we hold dnh_zrlock, we can 852 * safely move any dnode referenced only by dbufs. 853 */ 854 if (!zrl_tryenter(&odn->dn_handle->dnh_zrlock)) { 855 mutex_exit(&os->os_lock); 856 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_handle); 857 return (KMEM_CBRC_LATER); 858 } 859 860 /* 861 * Ensure a consistent view of the dnode's holds and the dnode's dbufs. 862 * We need to guarantee that there is a hold for every dbuf in order to 863 * determine whether the dnode is actively referenced. Falsely matching 864 * a dbuf to an active hold would lead to an unsafe move. It's possible 865 * that a thread already having an active dnode hold is about to add a 866 * dbuf, and we can't compare hold and dbuf counts while the add is in 867 * progress. 868 */ 869 if (!rw_tryenter(&odn->dn_struct_rwlock, RW_WRITER)) { 870 zrl_exit(&odn->dn_handle->dnh_zrlock); 871 mutex_exit(&os->os_lock); 872 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_rwlock); 873 return (KMEM_CBRC_LATER); 874 } 875 876 /* 877 * A dbuf may be removed (evicted) without an active dnode hold. In that 878 * case, the dbuf count is decremented under the handle lock before the 879 * dbuf's hold is released. This order ensures that if we count the hold 880 * after the dbuf is removed but before its hold is released, we will 881 * treat the unmatched hold as active and exit safely. If we count the 882 * hold before the dbuf is removed, the hold is discounted, and the 883 * removal is blocked until the move completes. 884 */ 885 refcount = refcount_count(&odn->dn_holds); 886 ASSERT(refcount >= 0); 887 dbufs = odn->dn_dbufs_count; 888 889 /* We can't have more dbufs than dnode holds. */ 890 ASSERT3U(dbufs, <=, refcount); 891 DTRACE_PROBE3(dnode__move, dnode_t *, odn, int64_t, refcount, 892 uint32_t, dbufs); 893 894 if (refcount > dbufs) { 895 rw_exit(&odn->dn_struct_rwlock); 896 zrl_exit(&odn->dn_handle->dnh_zrlock); 897 mutex_exit(&os->os_lock); 898 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_active); 899 return (KMEM_CBRC_LATER); 900 } 901 902 rw_exit(&odn->dn_struct_rwlock); 903 904 /* 905 * At this point we know that anyone with a hold on the dnode is not 906 * actively referencing it. The dnode is known and in a valid state to 907 * move. We're holding the locks needed to execute the critical section. 908 */ 909 dnode_move_impl(odn, ndn); 910 911 list_link_replace(&odn->dn_link, &ndn->dn_link); 912 /* If the dnode was safe to move, the refcount cannot have changed. */ 913 ASSERT(refcount == refcount_count(&ndn->dn_holds)); 914 ASSERT(dbufs == ndn->dn_dbufs_count); 915 zrl_exit(&ndn->dn_handle->dnh_zrlock); /* handle has moved */ 916 mutex_exit(&os->os_lock); 917 918 return (KMEM_CBRC_YES); 919} 920#endif /* _KERNEL */ 921#endif /* sun */ 922 923void 924dnode_special_close(dnode_handle_t *dnh) 925{ 926 dnode_t *dn = dnh->dnh_dnode; 927 928 /* 929 * Wait for final references to the dnode to clear. This can 930 * only happen if the arc is asyncronously evicting state that 931 * has a hold on this dnode while we are trying to evict this 932 * dnode. 933 */ 934 while (refcount_count(&dn->dn_holds) > 0) 935 delay(1); 936 zrl_add(&dnh->dnh_zrlock); 937 dnode_destroy(dn); /* implicit zrl_remove() */ 938 zrl_destroy(&dnh->dnh_zrlock); 939 dnh->dnh_dnode = NULL; 940} 941 942dnode_t * 943dnode_special_open(objset_t *os, dnode_phys_t *dnp, uint64_t object, 944 dnode_handle_t *dnh) 945{ 946 dnode_t *dn = dnode_create(os, dnp, NULL, object, dnh); 947 dnh->dnh_dnode = dn; 948 zrl_init(&dnh->dnh_zrlock); 949 DNODE_VERIFY(dn); 950 return (dn); 951} 952 953static void 954dnode_buf_pageout(dmu_buf_t *db, void *arg) 955{ 956 dnode_children_t *children_dnodes = arg; 957 int i; 958 int epb = db->db_size >> DNODE_SHIFT; 959 960 ASSERT(epb == children_dnodes->dnc_count); 961 962 for (i = 0; i < epb; i++) { 963 dnode_handle_t *dnh = &children_dnodes->dnc_children[i]; 964 dnode_t *dn; 965 966 /* 967 * The dnode handle lock guards against the dnode moving to 968 * another valid address, so there is no need here to guard 969 * against changes to or from NULL. 970 */ 971 if (dnh->dnh_dnode == NULL) { 972 zrl_destroy(&dnh->dnh_zrlock); 973 continue; 974 } 975 976 zrl_add(&dnh->dnh_zrlock); 977 dn = dnh->dnh_dnode; 978 /* 979 * If there are holds on this dnode, then there should 980 * be holds on the dnode's containing dbuf as well; thus 981 * it wouldn't be eligible for eviction and this function 982 * would not have been called. 983 */ 984 ASSERT(refcount_is_zero(&dn->dn_holds)); 985 ASSERT(refcount_is_zero(&dn->dn_tx_holds)); 986 987 dnode_destroy(dn); /* implicit zrl_remove() */ 988 zrl_destroy(&dnh->dnh_zrlock); 989 dnh->dnh_dnode = NULL; 990 } 991 kmem_free(children_dnodes, sizeof (dnode_children_t) + 992 (epb - 1) * sizeof (dnode_handle_t)); 993} 994 995/* 996 * errors: 997 * EINVAL - invalid object number. 998 * EIO - i/o error. 999 * succeeds even for free dnodes. 1000 */ 1001int 1002dnode_hold_impl(objset_t *os, uint64_t object, int flag, 1003 void *tag, dnode_t **dnp) 1004{ 1005 int epb, idx, err; 1006 int drop_struct_lock = FALSE; 1007 int type; 1008 uint64_t blk; 1009 dnode_t *mdn, *dn; 1010 dmu_buf_impl_t *db; 1011 dnode_children_t *children_dnodes; 1012 dnode_handle_t *dnh; 1013 1014 /* 1015 * If you are holding the spa config lock as writer, you shouldn't 1016 * be asking the DMU to do *anything* unless it's the root pool 1017 * which may require us to read from the root filesystem while 1018 * holding some (not all) of the locks as writer. 1019 */ 1020 ASSERT(spa_config_held(os->os_spa, SCL_ALL, RW_WRITER) == 0 || 1021 (spa_is_root(os->os_spa) && 1022 spa_config_held(os->os_spa, SCL_STATE, RW_WRITER))); 1023 1024 if (object == DMU_USERUSED_OBJECT || object == DMU_GROUPUSED_OBJECT) { 1025 dn = (object == DMU_USERUSED_OBJECT) ? 1026 DMU_USERUSED_DNODE(os) : DMU_GROUPUSED_DNODE(os); 1027 if (dn == NULL) 1028 return (SET_ERROR(ENOENT)); 1029 type = dn->dn_type; 1030 if ((flag & DNODE_MUST_BE_ALLOCATED) && type == DMU_OT_NONE) 1031 return (SET_ERROR(ENOENT)); 1032 if ((flag & DNODE_MUST_BE_FREE) && type != DMU_OT_NONE) 1033 return (SET_ERROR(EEXIST)); 1034 DNODE_VERIFY(dn); 1035 (void) refcount_add(&dn->dn_holds, tag); 1036 *dnp = dn; 1037 return (0); 1038 } 1039 1040 if (object == 0 || object >= DN_MAX_OBJECT) 1041 return (SET_ERROR(EINVAL)); 1042 1043 mdn = DMU_META_DNODE(os); 1044 ASSERT(mdn->dn_object == DMU_META_DNODE_OBJECT); 1045 1046 DNODE_VERIFY(mdn); 1047 1048 if (!RW_WRITE_HELD(&mdn->dn_struct_rwlock)) { 1049 rw_enter(&mdn->dn_struct_rwlock, RW_READER); 1050 drop_struct_lock = TRUE; 1051 } 1052 1053 blk = dbuf_whichblock(mdn, object * sizeof (dnode_phys_t)); 1054 1055 db = dbuf_hold(mdn, blk, FTAG); 1056 if (drop_struct_lock) 1057 rw_exit(&mdn->dn_struct_rwlock); 1058 if (db == NULL) 1059 return (SET_ERROR(EIO)); 1060 err = dbuf_read(db, NULL, DB_RF_CANFAIL); 1061 if (err) { 1062 dbuf_rele(db, FTAG); 1063 return (err); 1064 } 1065 1066 ASSERT3U(db->db.db_size, >=, 1<<DNODE_SHIFT); 1067 epb = db->db.db_size >> DNODE_SHIFT; 1068 1069 idx = object & (epb-1); 1070 1071 ASSERT(DB_DNODE(db)->dn_type == DMU_OT_DNODE); 1072 children_dnodes = dmu_buf_get_user(&db->db); 1073 if (children_dnodes == NULL) { 1074 int i; 1075 dnode_children_t *winner; 1076 children_dnodes = kmem_zalloc(sizeof (dnode_children_t) + 1077 (epb - 1) * sizeof (dnode_handle_t), KM_SLEEP); 1078 children_dnodes->dnc_count = epb; 1079 dnh = &children_dnodes->dnc_children[0]; 1080 for (i = 0; i < epb; i++) { 1081 zrl_init(&dnh[i].dnh_zrlock); 1082 dnh[i].dnh_dnode = NULL; 1083 } 1084 if (winner = dmu_buf_set_user(&db->db, children_dnodes, NULL, 1085 dnode_buf_pageout)) { 1086 kmem_free(children_dnodes, sizeof (dnode_children_t) + 1087 (epb - 1) * sizeof (dnode_handle_t)); 1088 children_dnodes = winner; 1089 } 1090 } 1091 ASSERT(children_dnodes->dnc_count == epb); 1092 1093 dnh = &children_dnodes->dnc_children[idx]; 1094 zrl_add(&dnh->dnh_zrlock); 1095 if ((dn = dnh->dnh_dnode) == NULL) { 1096 dnode_phys_t *phys = (dnode_phys_t *)db->db.db_data+idx; 1097 dnode_t *winner; 1098 1099 dn = dnode_create(os, phys, db, object, dnh); 1100 winner = atomic_cas_ptr(&dnh->dnh_dnode, NULL, dn); 1101 if (winner != NULL) { 1102 zrl_add(&dnh->dnh_zrlock); 1103 dnode_destroy(dn); /* implicit zrl_remove() */ 1104 dn = winner; 1105 } 1106 } 1107 1108 mutex_enter(&dn->dn_mtx); 1109 type = dn->dn_type; 1110 if (dn->dn_free_txg || 1111 ((flag & DNODE_MUST_BE_ALLOCATED) && type == DMU_OT_NONE) || 1112 ((flag & DNODE_MUST_BE_FREE) && 1113 (type != DMU_OT_NONE || !refcount_is_zero(&dn->dn_holds)))) { 1114 mutex_exit(&dn->dn_mtx); 1115 zrl_remove(&dnh->dnh_zrlock); 1116 dbuf_rele(db, FTAG); 1117 return (type == DMU_OT_NONE ? ENOENT : EEXIST); 1118 } 1119 mutex_exit(&dn->dn_mtx); 1120 1121 if (refcount_add(&dn->dn_holds, tag) == 1) 1122 dbuf_add_ref(db, dnh); 1123 /* Now we can rely on the hold to prevent the dnode from moving. */ 1124 zrl_remove(&dnh->dnh_zrlock); 1125 1126 DNODE_VERIFY(dn); 1127 ASSERT3P(dn->dn_dbuf, ==, db); 1128 ASSERT3U(dn->dn_object, ==, object); 1129 dbuf_rele(db, FTAG); 1130 1131 *dnp = dn; 1132 return (0); 1133} 1134 1135/* 1136 * Return held dnode if the object is allocated, NULL if not. 1137 */ 1138int 1139dnode_hold(objset_t *os, uint64_t object, void *tag, dnode_t **dnp) 1140{ 1141 return (dnode_hold_impl(os, object, DNODE_MUST_BE_ALLOCATED, tag, dnp)); 1142} 1143 1144/* 1145 * Can only add a reference if there is already at least one 1146 * reference on the dnode. Returns FALSE if unable to add a 1147 * new reference. 1148 */ 1149boolean_t 1150dnode_add_ref(dnode_t *dn, void *tag) 1151{ 1152 mutex_enter(&dn->dn_mtx); 1153 if (refcount_is_zero(&dn->dn_holds)) { 1154 mutex_exit(&dn->dn_mtx); 1155 return (FALSE); 1156 } 1157 VERIFY(1 < refcount_add(&dn->dn_holds, tag)); 1158 mutex_exit(&dn->dn_mtx); 1159 return (TRUE); 1160} 1161 1162void 1163dnode_rele(dnode_t *dn, void *tag) 1164{ 1165 uint64_t refs; 1166 /* Get while the hold prevents the dnode from moving. */ 1167 dmu_buf_impl_t *db = dn->dn_dbuf; 1168 dnode_handle_t *dnh = dn->dn_handle; 1169 1170 mutex_enter(&dn->dn_mtx); 1171 refs = refcount_remove(&dn->dn_holds, tag); 1172 mutex_exit(&dn->dn_mtx); 1173 1174 /* 1175 * It's unsafe to release the last hold on a dnode by dnode_rele() or 1176 * indirectly by dbuf_rele() while relying on the dnode handle to 1177 * prevent the dnode from moving, since releasing the last hold could 1178 * result in the dnode's parent dbuf evicting its dnode handles. For 1179 * that reason anyone calling dnode_rele() or dbuf_rele() without some 1180 * other direct or indirect hold on the dnode must first drop the dnode 1181 * handle. 1182 */ 1183 ASSERT(refs > 0 || dnh->dnh_zrlock.zr_owner != curthread); 1184 1185 /* NOTE: the DNODE_DNODE does not have a dn_dbuf */ 1186 if (refs == 0 && db != NULL) { 1187 /* 1188 * Another thread could add a hold to the dnode handle in 1189 * dnode_hold_impl() while holding the parent dbuf. Since the 1190 * hold on the parent dbuf prevents the handle from being 1191 * destroyed, the hold on the handle is OK. We can't yet assert 1192 * that the handle has zero references, but that will be 1193 * asserted anyway when the handle gets destroyed. 1194 */ 1195 dbuf_rele(db, dnh); 1196 } 1197} 1198 1199void 1200dnode_setdirty(dnode_t *dn, dmu_tx_t *tx) 1201{ 1202 objset_t *os = dn->dn_objset; 1203 uint64_t txg = tx->tx_txg; 1204 1205 if (DMU_OBJECT_IS_SPECIAL(dn->dn_object)) { 1206 dsl_dataset_dirty(os->os_dsl_dataset, tx); 1207 return; 1208 } 1209 1210 DNODE_VERIFY(dn); 1211 1212#ifdef ZFS_DEBUG 1213 mutex_enter(&dn->dn_mtx); 1214 ASSERT(dn->dn_phys->dn_type || dn->dn_allocated_txg); 1215 ASSERT(dn->dn_free_txg == 0 || dn->dn_free_txg >= txg); 1216 mutex_exit(&dn->dn_mtx); 1217#endif 1218 1219 /* 1220 * Determine old uid/gid when necessary 1221 */ 1222 dmu_objset_userquota_get_ids(dn, B_TRUE, tx); 1223 1224 mutex_enter(&os->os_lock); 1225 1226 /* 1227 * If we are already marked dirty, we're done. 1228 */ 1229 if (list_link_active(&dn->dn_dirty_link[txg & TXG_MASK])) { 1230 mutex_exit(&os->os_lock); 1231 return; 1232 } 1233 1234 ASSERT(!refcount_is_zero(&dn->dn_holds) || list_head(&dn->dn_dbufs)); 1235 ASSERT(dn->dn_datablksz != 0); 1236 ASSERT0(dn->dn_next_bonuslen[txg&TXG_MASK]); 1237 ASSERT0(dn->dn_next_blksz[txg&TXG_MASK]); 1238 ASSERT0(dn->dn_next_bonustype[txg&TXG_MASK]); 1239 1240 dprintf_ds(os->os_dsl_dataset, "obj=%llu txg=%llu\n", 1241 dn->dn_object, txg); 1242 1243 if (dn->dn_free_txg > 0 && dn->dn_free_txg <= txg) { 1244 list_insert_tail(&os->os_free_dnodes[txg&TXG_MASK], dn); 1245 } else { 1246 list_insert_tail(&os->os_dirty_dnodes[txg&TXG_MASK], dn); 1247 } 1248 1249 mutex_exit(&os->os_lock); 1250 1251 /* 1252 * The dnode maintains a hold on its containing dbuf as 1253 * long as there are holds on it. Each instantiated child 1254 * dbuf maintains a hold on the dnode. When the last child 1255 * drops its hold, the dnode will drop its hold on the 1256 * containing dbuf. We add a "dirty hold" here so that the 1257 * dnode will hang around after we finish processing its 1258 * children. 1259 */ 1260 VERIFY(dnode_add_ref(dn, (void *)(uintptr_t)tx->tx_txg)); 1261 1262 (void) dbuf_dirty(dn->dn_dbuf, tx); 1263 1264 dsl_dataset_dirty(os->os_dsl_dataset, tx); 1265} 1266 1267void 1268dnode_free(dnode_t *dn, dmu_tx_t *tx) 1269{ 1270 int txgoff = tx->tx_txg & TXG_MASK; 1271 1272 dprintf("dn=%p txg=%llu\n", dn, tx->tx_txg); 1273 1274 /* we should be the only holder... hopefully */ 1275 /* ASSERT3U(refcount_count(&dn->dn_holds), ==, 1); */ 1276 1277 mutex_enter(&dn->dn_mtx); 1278 if (dn->dn_type == DMU_OT_NONE || dn->dn_free_txg) { 1279 mutex_exit(&dn->dn_mtx); 1280 return; 1281 } 1282 dn->dn_free_txg = tx->tx_txg; 1283 mutex_exit(&dn->dn_mtx); 1284 1285 /* 1286 * If the dnode is already dirty, it needs to be moved from 1287 * the dirty list to the free list. 1288 */ 1289 mutex_enter(&dn->dn_objset->os_lock); 1290 if (list_link_active(&dn->dn_dirty_link[txgoff])) { 1291 list_remove(&dn->dn_objset->os_dirty_dnodes[txgoff], dn); 1292 list_insert_tail(&dn->dn_objset->os_free_dnodes[txgoff], dn); 1293 mutex_exit(&dn->dn_objset->os_lock); 1294 } else { 1295 mutex_exit(&dn->dn_objset->os_lock); 1296 dnode_setdirty(dn, tx); 1297 } 1298} 1299 1300/* 1301 * Try to change the block size for the indicated dnode. This can only 1302 * succeed if there are no blocks allocated or dirty beyond first block 1303 */ 1304int 1305dnode_set_blksz(dnode_t *dn, uint64_t size, int ibs, dmu_tx_t *tx) 1306{ 1307 dmu_buf_impl_t *db, *db_next; 1308 int err; 1309 1310 if (size == 0) 1311 size = SPA_MINBLOCKSIZE; 1312 if (size > SPA_MAXBLOCKSIZE) 1313 size = SPA_MAXBLOCKSIZE; 1314 else 1315 size = P2ROUNDUP(size, SPA_MINBLOCKSIZE); 1316 1317 if (ibs == dn->dn_indblkshift) 1318 ibs = 0; 1319 1320 if (size >> SPA_MINBLOCKSHIFT == dn->dn_datablkszsec && ibs == 0) 1321 return (0); 1322 1323 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 1324 1325 /* Check for any allocated blocks beyond the first */ 1326 if (dn->dn_maxblkid != 0) 1327 goto fail; 1328 1329 mutex_enter(&dn->dn_dbufs_mtx); 1330 for (db = list_head(&dn->dn_dbufs); db; db = db_next) { 1331 db_next = list_next(&dn->dn_dbufs, db); 1332 1333 if (db->db_blkid != 0 && db->db_blkid != DMU_BONUS_BLKID && 1334 db->db_blkid != DMU_SPILL_BLKID) { 1335 mutex_exit(&dn->dn_dbufs_mtx); 1336 goto fail; 1337 } 1338 } 1339 mutex_exit(&dn->dn_dbufs_mtx); 1340 1341 if (ibs && dn->dn_nlevels != 1) 1342 goto fail; 1343 1344 /* resize the old block */ 1345 err = dbuf_hold_impl(dn, 0, 0, TRUE, FTAG, &db); 1346 if (err == 0) 1347 dbuf_new_size(db, size, tx); 1348 else if (err != ENOENT) 1349 goto fail; 1350 1351 dnode_setdblksz(dn, size); 1352 dnode_setdirty(dn, tx); 1353 dn->dn_next_blksz[tx->tx_txg&TXG_MASK] = size; 1354 if (ibs) { 1355 dn->dn_indblkshift = ibs; 1356 dn->dn_next_indblkshift[tx->tx_txg&TXG_MASK] = ibs; 1357 } 1358 /* rele after we have fixed the blocksize in the dnode */ 1359 if (db) 1360 dbuf_rele(db, FTAG); 1361 1362 rw_exit(&dn->dn_struct_rwlock); 1363 return (0); 1364 1365fail: 1366 rw_exit(&dn->dn_struct_rwlock); 1367 return (SET_ERROR(ENOTSUP)); 1368} 1369 1370/* read-holding callers must not rely on the lock being continuously held */ 1371void 1372dnode_new_blkid(dnode_t *dn, uint64_t blkid, dmu_tx_t *tx, boolean_t have_read) 1373{ 1374 uint64_t txgoff = tx->tx_txg & TXG_MASK; 1375 int epbs, new_nlevels; 1376 uint64_t sz; 1377 1378 ASSERT(blkid != DMU_BONUS_BLKID); 1379 1380 ASSERT(have_read ? 1381 RW_READ_HELD(&dn->dn_struct_rwlock) : 1382 RW_WRITE_HELD(&dn->dn_struct_rwlock)); 1383 1384 /* 1385 * if we have a read-lock, check to see if we need to do any work 1386 * before upgrading to a write-lock. 1387 */ 1388 if (have_read) { 1389 if (blkid <= dn->dn_maxblkid) 1390 return; 1391 1392 if (!rw_tryupgrade(&dn->dn_struct_rwlock)) { 1393 rw_exit(&dn->dn_struct_rwlock); 1394 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 1395 } 1396 } 1397 1398 if (blkid <= dn->dn_maxblkid) 1399 goto out; 1400 1401 dn->dn_maxblkid = blkid; 1402 1403 /* 1404 * Compute the number of levels necessary to support the new maxblkid. 1405 */ 1406 new_nlevels = 1; 1407 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT; 1408 for (sz = dn->dn_nblkptr; 1409 sz <= blkid && sz >= dn->dn_nblkptr; sz <<= epbs) 1410 new_nlevels++; 1411 1412 if (new_nlevels > dn->dn_nlevels) { 1413 int old_nlevels = dn->dn_nlevels; 1414 dmu_buf_impl_t *db; 1415 list_t *list; 1416 dbuf_dirty_record_t *new, *dr, *dr_next; 1417 1418 dn->dn_nlevels = new_nlevels; 1419 1420 ASSERT3U(new_nlevels, >, dn->dn_next_nlevels[txgoff]); 1421 dn->dn_next_nlevels[txgoff] = new_nlevels; 1422 1423 /* dirty the left indirects */ 1424 db = dbuf_hold_level(dn, old_nlevels, 0, FTAG); 1425 ASSERT(db != NULL); 1426 new = dbuf_dirty(db, tx); 1427 dbuf_rele(db, FTAG); 1428 1429 /* transfer the dirty records to the new indirect */ 1430 mutex_enter(&dn->dn_mtx); 1431 mutex_enter(&new->dt.di.dr_mtx); 1432 list = &dn->dn_dirty_records[txgoff]; 1433 for (dr = list_head(list); dr; dr = dr_next) { 1434 dr_next = list_next(&dn->dn_dirty_records[txgoff], dr); 1435 if (dr->dr_dbuf->db_level != new_nlevels-1 && 1436 dr->dr_dbuf->db_blkid != DMU_BONUS_BLKID && 1437 dr->dr_dbuf->db_blkid != DMU_SPILL_BLKID) { 1438 ASSERT(dr->dr_dbuf->db_level == old_nlevels-1); 1439 list_remove(&dn->dn_dirty_records[txgoff], dr); 1440 list_insert_tail(&new->dt.di.dr_children, dr); 1441 dr->dr_parent = new; 1442 } 1443 } 1444 mutex_exit(&new->dt.di.dr_mtx); 1445 mutex_exit(&dn->dn_mtx); 1446 } 1447 1448out: 1449 if (have_read) 1450 rw_downgrade(&dn->dn_struct_rwlock); 1451} 1452 1453void 1454dnode_free_range(dnode_t *dn, uint64_t off, uint64_t len, dmu_tx_t *tx) 1455{ 1456 dmu_buf_impl_t *db; 1457 uint64_t blkoff, blkid, nblks; 1458 int blksz, blkshift, head, tail; 1459 int trunc = FALSE; 1460 int epbs; 1461 1462 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 1463 blksz = dn->dn_datablksz; 1464 blkshift = dn->dn_datablkshift; 1465 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT; 1466 1467 if (len == DMU_OBJECT_END) { 1468 len = UINT64_MAX - off; 1469 trunc = TRUE; 1470 } 1471 1472 /* 1473 * First, block align the region to free: 1474 */ 1475 if (ISP2(blksz)) { 1476 head = P2NPHASE(off, blksz); 1477 blkoff = P2PHASE(off, blksz); 1478 if ((off >> blkshift) > dn->dn_maxblkid) 1479 goto out; 1480 } else { 1481 ASSERT(dn->dn_maxblkid == 0); 1482 if (off == 0 && len >= blksz) { 1483 /* 1484 * Freeing the whole block; fast-track this request. 1485 * Note that we won't dirty any indirect blocks, 1486 * which is fine because we will be freeing the entire 1487 * file and thus all indirect blocks will be freed 1488 * by free_children(). 1489 */ 1490 blkid = 0; 1491 nblks = 1; 1492 goto done; 1493 } else if (off >= blksz) { 1494 /* Freeing past end-of-data */ 1495 goto out; 1496 } else { 1497 /* Freeing part of the block. */ 1498 head = blksz - off; 1499 ASSERT3U(head, >, 0); 1500 } 1501 blkoff = off; 1502 } 1503 /* zero out any partial block data at the start of the range */ 1504 if (head) { 1505 ASSERT3U(blkoff + head, ==, blksz); 1506 if (len < head) 1507 head = len; 1508 if (dbuf_hold_impl(dn, 0, dbuf_whichblock(dn, off), TRUE, 1509 FTAG, &db) == 0) { 1510 caddr_t data; 1511 1512 /* don't dirty if it isn't on disk and isn't dirty */ 1513 if (db->db_last_dirty || 1514 (db->db_blkptr && !BP_IS_HOLE(db->db_blkptr))) { 1515 rw_exit(&dn->dn_struct_rwlock); 1516 dmu_buf_will_dirty(&db->db, tx); 1517 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 1518 data = db->db.db_data; 1519 bzero(data + blkoff, head); 1520 } 1521 dbuf_rele(db, FTAG); 1522 } 1523 off += head; 1524 len -= head; 1525 } 1526 1527 /* If the range was less than one block, we're done */ 1528 if (len == 0) 1529 goto out; 1530 1531 /* If the remaining range is past end of file, we're done */ 1532 if ((off >> blkshift) > dn->dn_maxblkid) 1533 goto out; 1534 1535 ASSERT(ISP2(blksz)); 1536 if (trunc) 1537 tail = 0; 1538 else 1539 tail = P2PHASE(len, blksz); 1540 1541 ASSERT0(P2PHASE(off, blksz)); 1542 /* zero out any partial block data at the end of the range */ 1543 if (tail) { 1544 if (len < tail) 1545 tail = len; 1546 if (dbuf_hold_impl(dn, 0, dbuf_whichblock(dn, off+len), 1547 TRUE, FTAG, &db) == 0) { 1548 /* don't dirty if not on disk and not dirty */ 1549 if (db->db_last_dirty || 1550 (db->db_blkptr && !BP_IS_HOLE(db->db_blkptr))) { 1551 rw_exit(&dn->dn_struct_rwlock); 1552 dmu_buf_will_dirty(&db->db, tx); 1553 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 1554 bzero(db->db.db_data, tail); 1555 } 1556 dbuf_rele(db, FTAG); 1557 } 1558 len -= tail; 1559 } 1560 1561 /* If the range did not include a full block, we are done */ 1562 if (len == 0) 1563 goto out; 1564 1565 ASSERT(IS_P2ALIGNED(off, blksz)); 1566 ASSERT(trunc || IS_P2ALIGNED(len, blksz)); 1567 blkid = off >> blkshift; 1568 nblks = len >> blkshift; 1569 if (trunc) 1570 nblks += 1; 1571 1572 /* 1573 * Dirty the first and last indirect blocks, as they (and/or their 1574 * parents) will need to be written out if they were only 1575 * partially freed. Interior indirect blocks will be themselves freed, 1576 * by free_children(), so they need not be dirtied. Note that these 1577 * interior blocks have already been prefetched by dmu_tx_hold_free(). 1578 */ 1579 if (dn->dn_nlevels > 1) { 1580 uint64_t first, last; 1581 1582 first = blkid >> epbs; 1583 if (db = dbuf_hold_level(dn, 1, first, FTAG)) { 1584 dmu_buf_will_dirty(&db->db, tx); 1585 dbuf_rele(db, FTAG); 1586 } 1587 if (trunc) 1588 last = dn->dn_maxblkid >> epbs; 1589 else 1590 last = (blkid + nblks - 1) >> epbs; 1591 if (last > first && (db = dbuf_hold_level(dn, 1, last, FTAG))) { 1592 dmu_buf_will_dirty(&db->db, tx); 1593 dbuf_rele(db, FTAG); 1594 } 1595 } 1596 1597done: 1598 /* 1599 * Add this range to the dnode range list. 1600 * We will finish up this free operation in the syncing phase. 1601 */ 1602 mutex_enter(&dn->dn_mtx); 1603 int txgoff = tx->tx_txg & TXG_MASK; 1604 if (dn->dn_free_ranges[txgoff] == NULL) { 1605 dn->dn_free_ranges[txgoff] = 1606 range_tree_create(NULL, NULL, &dn->dn_mtx); 1607 } 1608 range_tree_clear(dn->dn_free_ranges[txgoff], blkid, nblks); 1609 range_tree_add(dn->dn_free_ranges[txgoff], blkid, nblks); 1610 dprintf_dnode(dn, "blkid=%llu nblks=%llu txg=%llu\n", 1611 blkid, nblks, tx->tx_txg); 1612 mutex_exit(&dn->dn_mtx); 1613 1614 dbuf_free_range(dn, blkid, blkid + nblks - 1, tx); 1615 dnode_setdirty(dn, tx); 1616out: 1617 1618 rw_exit(&dn->dn_struct_rwlock); 1619} 1620 1621static boolean_t 1622dnode_spill_freed(dnode_t *dn) 1623{ 1624 int i; 1625 1626 mutex_enter(&dn->dn_mtx); 1627 for (i = 0; i < TXG_SIZE; i++) { 1628 if (dn->dn_rm_spillblk[i] == DN_KILL_SPILLBLK) 1629 break; 1630 } 1631 mutex_exit(&dn->dn_mtx); 1632 return (i < TXG_SIZE); 1633} 1634 1635/* return TRUE if this blkid was freed in a recent txg, or FALSE if it wasn't */ 1636uint64_t 1637dnode_block_freed(dnode_t *dn, uint64_t blkid) 1638{ 1639 void *dp = spa_get_dsl(dn->dn_objset->os_spa); 1640 int i; 1641 1642 if (blkid == DMU_BONUS_BLKID) 1643 return (FALSE); 1644 1645 /* 1646 * If we're in the process of opening the pool, dp will not be 1647 * set yet, but there shouldn't be anything dirty. 1648 */ 1649 if (dp == NULL) 1650 return (FALSE); 1651 1652 if (dn->dn_free_txg) 1653 return (TRUE); 1654 1655 if (blkid == DMU_SPILL_BLKID) 1656 return (dnode_spill_freed(dn)); 1657 1658 mutex_enter(&dn->dn_mtx); 1659 for (i = 0; i < TXG_SIZE; i++) { 1660 if (dn->dn_free_ranges[i] != NULL && 1661 range_tree_contains(dn->dn_free_ranges[i], blkid, 1)) 1662 break; 1663 } 1664 mutex_exit(&dn->dn_mtx); 1665 return (i < TXG_SIZE); 1666} 1667 1668/* call from syncing context when we actually write/free space for this dnode */ 1669void 1670dnode_diduse_space(dnode_t *dn, int64_t delta) 1671{ 1672 uint64_t space; 1673 dprintf_dnode(dn, "dn=%p dnp=%p used=%llu delta=%lld\n", 1674 dn, dn->dn_phys, 1675 (u_longlong_t)dn->dn_phys->dn_used, 1676 (longlong_t)delta); 1677 1678 mutex_enter(&dn->dn_mtx); 1679 space = DN_USED_BYTES(dn->dn_phys); 1680 if (delta > 0) { 1681 ASSERT3U(space + delta, >=, space); /* no overflow */ 1682 } else { 1683 ASSERT3U(space, >=, -delta); /* no underflow */ 1684 } 1685 space += delta; 1686 if (spa_version(dn->dn_objset->os_spa) < SPA_VERSION_DNODE_BYTES) { 1687 ASSERT((dn->dn_phys->dn_flags & DNODE_FLAG_USED_BYTES) == 0); 1688 ASSERT0(P2PHASE(space, 1<<DEV_BSHIFT)); 1689 dn->dn_phys->dn_used = space >> DEV_BSHIFT; 1690 } else { 1691 dn->dn_phys->dn_used = space; 1692 dn->dn_phys->dn_flags |= DNODE_FLAG_USED_BYTES; 1693 } 1694 mutex_exit(&dn->dn_mtx); 1695} 1696 1697/* 1698 * Call when we think we're going to write/free space in open context to track 1699 * the amount of memory in use by the currently open txg. 1700 */ 1701void 1702dnode_willuse_space(dnode_t *dn, int64_t space, dmu_tx_t *tx) 1703{ 1704 objset_t *os = dn->dn_objset; 1705 dsl_dataset_t *ds = os->os_dsl_dataset; 1706 int64_t aspace = spa_get_asize(os->os_spa, space); 1707 1708 if (ds != NULL) { 1709 dsl_dir_willuse_space(ds->ds_dir, aspace, tx); 1710 dsl_pool_dirty_space(dmu_tx_pool(tx), space, tx); 1711 } 1712 1713 dmu_tx_willuse_space(tx, aspace); 1714} 1715 1716/* 1717 * Scans a block at the indicated "level" looking for a hole or data, 1718 * depending on 'flags'. 1719 * 1720 * If level > 0, then we are scanning an indirect block looking at its 1721 * pointers. If level == 0, then we are looking at a block of dnodes. 1722 * 1723 * If we don't find what we are looking for in the block, we return ESRCH. 1724 * Otherwise, return with *offset pointing to the beginning (if searching 1725 * forwards) or end (if searching backwards) of the range covered by the 1726 * block pointer we matched on (or dnode). 1727 * 1728 * The basic search algorithm used below by dnode_next_offset() is to 1729 * use this function to search up the block tree (widen the search) until 1730 * we find something (i.e., we don't return ESRCH) and then search back 1731 * down the tree (narrow the search) until we reach our original search 1732 * level. 1733 */ 1734static int 1735dnode_next_offset_level(dnode_t *dn, int flags, uint64_t *offset, 1736 int lvl, uint64_t blkfill, uint64_t txg) 1737{ 1738 dmu_buf_impl_t *db = NULL; 1739 void *data = NULL; 1740 uint64_t epbs = dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT; 1741 uint64_t epb = 1ULL << epbs; 1742 uint64_t minfill, maxfill; 1743 boolean_t hole; 1744 int i, inc, error, span; 1745 1746 dprintf("probing object %llu offset %llx level %d of %u\n", 1747 dn->dn_object, *offset, lvl, dn->dn_phys->dn_nlevels); 1748 1749 hole = ((flags & DNODE_FIND_HOLE) != 0); 1750 inc = (flags & DNODE_FIND_BACKWARDS) ? -1 : 1; 1751 ASSERT(txg == 0 || !hole); 1752 1753 if (lvl == dn->dn_phys->dn_nlevels) { 1754 error = 0; 1755 epb = dn->dn_phys->dn_nblkptr; 1756 data = dn->dn_phys->dn_blkptr; 1757 } else { 1758 uint64_t blkid = dbuf_whichblock(dn, *offset) >> (epbs * lvl); 1759 error = dbuf_hold_impl(dn, lvl, blkid, TRUE, FTAG, &db); 1760 if (error) { 1761 if (error != ENOENT) 1762 return (error); 1763 if (hole) 1764 return (0); 1765 /* 1766 * This can only happen when we are searching up 1767 * the block tree for data. We don't really need to 1768 * adjust the offset, as we will just end up looking 1769 * at the pointer to this block in its parent, and its 1770 * going to be unallocated, so we will skip over it. 1771 */ 1772 return (SET_ERROR(ESRCH)); 1773 } 1774 error = dbuf_read(db, NULL, DB_RF_CANFAIL | DB_RF_HAVESTRUCT); 1775 if (error) { 1776 dbuf_rele(db, FTAG); 1777 return (error); 1778 } 1779 data = db->db.db_data; 1780 } 1781 1782 1783 if (db != NULL && txg != 0 && (db->db_blkptr == NULL || 1784 db->db_blkptr->blk_birth <= txg || 1785 BP_IS_HOLE(db->db_blkptr))) { 1786 /* 1787 * This can only happen when we are searching up the tree 1788 * and these conditions mean that we need to keep climbing. 1789 */ 1790 error = SET_ERROR(ESRCH); 1791 } else if (lvl == 0) { 1792 dnode_phys_t *dnp = data; 1793 span = DNODE_SHIFT; 1794 ASSERT(dn->dn_type == DMU_OT_DNODE); 1795 1796 for (i = (*offset >> span) & (blkfill - 1); 1797 i >= 0 && i < blkfill; i += inc) { 1798 if ((dnp[i].dn_type == DMU_OT_NONE) == hole) 1799 break; 1800 *offset += (1ULL << span) * inc; 1801 } 1802 if (i < 0 || i == blkfill) 1803 error = SET_ERROR(ESRCH); 1804 } else { 1805 blkptr_t *bp = data; 1806 uint64_t start = *offset; 1807 span = (lvl - 1) * epbs + dn->dn_datablkshift; 1808 minfill = 0; 1809 maxfill = blkfill << ((lvl - 1) * epbs); 1810 1811 if (hole) 1812 maxfill--; 1813 else 1814 minfill++; 1815 1816 *offset = *offset >> span; 1817 for (i = BF64_GET(*offset, 0, epbs); 1818 i >= 0 && i < epb; i += inc) { 1819 if (BP_GET_FILL(&bp[i]) >= minfill && 1820 BP_GET_FILL(&bp[i]) <= maxfill && 1821 (hole || bp[i].blk_birth > txg)) 1822 break; 1823 if (inc > 0 || *offset > 0) 1824 *offset += inc; 1825 } 1826 *offset = *offset << span; 1827 if (inc < 0) { 1828 /* traversing backwards; position offset at the end */ 1829 ASSERT3U(*offset, <=, start); 1830 *offset = MIN(*offset + (1ULL << span) - 1, start); 1831 } else if (*offset < start) { 1832 *offset = start; 1833 } 1834 if (i < 0 || i >= epb) 1835 error = SET_ERROR(ESRCH); 1836 } 1837 1838 if (db) 1839 dbuf_rele(db, FTAG); 1840 1841 return (error); 1842} 1843 1844/* 1845 * Find the next hole, data, or sparse region at or after *offset. 1846 * The value 'blkfill' tells us how many items we expect to find 1847 * in an L0 data block; this value is 1 for normal objects, 1848 * DNODES_PER_BLOCK for the meta dnode, and some fraction of 1849 * DNODES_PER_BLOCK when searching for sparse regions thereof. 1850 * 1851 * Examples: 1852 * 1853 * dnode_next_offset(dn, flags, offset, 1, 1, 0); 1854 * Finds the next/previous hole/data in a file. 1855 * Used in dmu_offset_next(). 1856 * 1857 * dnode_next_offset(mdn, flags, offset, 0, DNODES_PER_BLOCK, txg); 1858 * Finds the next free/allocated dnode an objset's meta-dnode. 1859 * Only finds objects that have new contents since txg (ie. 1860 * bonus buffer changes and content removal are ignored). 1861 * Used in dmu_object_next(). 1862 * 1863 * dnode_next_offset(mdn, DNODE_FIND_HOLE, offset, 2, DNODES_PER_BLOCK >> 2, 0); 1864 * Finds the next L2 meta-dnode bp that's at most 1/4 full. 1865 * Used in dmu_object_alloc(). 1866 */ 1867int 1868dnode_next_offset(dnode_t *dn, int flags, uint64_t *offset, 1869 int minlvl, uint64_t blkfill, uint64_t txg) 1870{ 1871 uint64_t initial_offset = *offset; 1872 int lvl, maxlvl; 1873 int error = 0; 1874 1875 if (!(flags & DNODE_FIND_HAVELOCK)) 1876 rw_enter(&dn->dn_struct_rwlock, RW_READER); 1877 1878 if (dn->dn_phys->dn_nlevels == 0) { 1879 error = SET_ERROR(ESRCH); 1880 goto out; 1881 } 1882 1883 if (dn->dn_datablkshift == 0) { 1884 if (*offset < dn->dn_datablksz) { 1885 if (flags & DNODE_FIND_HOLE) 1886 *offset = dn->dn_datablksz; 1887 } else { 1888 error = SET_ERROR(ESRCH); 1889 } 1890 goto out; 1891 } 1892 1893 maxlvl = dn->dn_phys->dn_nlevels; 1894 1895 for (lvl = minlvl; lvl <= maxlvl; lvl++) { 1896 error = dnode_next_offset_level(dn, 1897 flags, offset, lvl, blkfill, txg); 1898 if (error != ESRCH) 1899 break; 1900 } 1901 1902 while (error == 0 && --lvl >= minlvl) { 1903 error = dnode_next_offset_level(dn, 1904 flags, offset, lvl, blkfill, txg); 1905 } 1906 1907 if (error == 0 && (flags & DNODE_FIND_BACKWARDS ? 1908 initial_offset < *offset : initial_offset > *offset)) 1909 error = SET_ERROR(ESRCH); 1910out: 1911 if (!(flags & DNODE_FIND_HAVELOCK)) 1912 rw_exit(&dn->dn_struct_rwlock); 1913 1914 return (error); 1915} 1916