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 2006 Sun Microsystems, Inc. All rights reserved. 23 * Use is subject to license terms. 24 */ 25 26 #pragma ident "%Z%%M% %I% %E% SMI" 27 28 #include <sys/zfs_context.h> 29 #include <sys/dbuf.h> 30 #include <sys/dnode.h> 31 #include <sys/dmu.h> 32 #include <sys/dmu_impl.h> 33 #include <sys/dmu_tx.h> 34 #include <sys/dmu_objset.h> 35 #include <sys/dsl_dir.h> 36 #include <sys/dsl_dataset.h> 37 #include <sys/spa.h> 38 #include <sys/zio.h> 39 #include <sys/dmu_zfetch.h> 40 41 static int free_range_compar(const void *node1, const void *node2); 42 43 static kmem_cache_t *dnode_cache; 44 45 static dnode_phys_t dnode_phys_zero; 46 47 int zfs_default_bs = SPA_MINBLOCKSHIFT; 48 int zfs_default_ibs = DN_MAX_INDBLKSHIFT; 49 50 /* ARGSUSED */ 51 static int 52 dnode_cons(void *arg, void *unused, int kmflag) 53 { 54 int i; 55 dnode_t *dn = arg; 56 bzero(dn, sizeof (dnode_t)); 57 58 rw_init(&dn->dn_struct_rwlock, NULL, RW_DEFAULT, NULL); 59 mutex_init(&dn->dn_mtx, NULL, MUTEX_DEFAULT, NULL); 60 mutex_init(&dn->dn_dbufs_mtx, NULL, MUTEX_DEFAULT, NULL); 61 refcount_create(&dn->dn_holds); 62 refcount_create(&dn->dn_tx_holds); 63 64 for (i = 0; i < TXG_SIZE; i++) { 65 avl_create(&dn->dn_ranges[i], free_range_compar, 66 sizeof (free_range_t), 67 offsetof(struct free_range, fr_node)); 68 list_create(&dn->dn_dirty_dbufs[i], 69 sizeof (dmu_buf_impl_t), 70 offsetof(dmu_buf_impl_t, db_dirty_node[i])); 71 } 72 73 list_create(&dn->dn_dbufs, sizeof (dmu_buf_impl_t), 74 offsetof(dmu_buf_impl_t, db_link)); 75 76 return (0); 77 } 78 79 /* ARGSUSED */ 80 static void 81 dnode_dest(void *arg, void *unused) 82 { 83 int i; 84 dnode_t *dn = arg; 85 86 rw_destroy(&dn->dn_struct_rwlock); 87 mutex_destroy(&dn->dn_mtx); 88 mutex_destroy(&dn->dn_dbufs_mtx); 89 refcount_destroy(&dn->dn_holds); 90 refcount_destroy(&dn->dn_tx_holds); 91 92 for (i = 0; i < TXG_SIZE; i++) { 93 avl_destroy(&dn->dn_ranges[i]); 94 list_destroy(&dn->dn_dirty_dbufs[i]); 95 } 96 97 list_destroy(&dn->dn_dbufs); 98 } 99 100 void 101 dnode_init(void) 102 { 103 dnode_cache = kmem_cache_create("dnode_t", 104 sizeof (dnode_t), 105 0, dnode_cons, dnode_dest, NULL, NULL, NULL, 0); 106 } 107 108 void 109 dnode_fini(void) 110 { 111 kmem_cache_destroy(dnode_cache); 112 } 113 114 115 #ifdef ZFS_DEBUG 116 void 117 dnode_verify(dnode_t *dn) 118 { 119 int drop_struct_lock = FALSE; 120 121 ASSERT(dn->dn_phys); 122 ASSERT(dn->dn_objset); 123 124 ASSERT(dn->dn_phys->dn_type < DMU_OT_NUMTYPES); 125 126 if (!(zfs_flags & ZFS_DEBUG_DNODE_VERIFY)) 127 return; 128 129 if (!RW_WRITE_HELD(&dn->dn_struct_rwlock)) { 130 rw_enter(&dn->dn_struct_rwlock, RW_READER); 131 drop_struct_lock = TRUE; 132 } 133 if (dn->dn_phys->dn_type != DMU_OT_NONE || dn->dn_allocated_txg != 0) { 134 int i; 135 ASSERT3U(dn->dn_indblkshift, >=, 0); 136 ASSERT3U(dn->dn_indblkshift, <=, SPA_MAXBLOCKSHIFT); 137 if (dn->dn_datablkshift) { 138 ASSERT3U(dn->dn_datablkshift, >=, SPA_MINBLOCKSHIFT); 139 ASSERT3U(dn->dn_datablkshift, <=, SPA_MAXBLOCKSHIFT); 140 ASSERT3U(1<<dn->dn_datablkshift, ==, dn->dn_datablksz); 141 } 142 ASSERT3U(dn->dn_nlevels, <=, 30); 143 ASSERT3U(dn->dn_type, <=, DMU_OT_NUMTYPES); 144 ASSERT3U(dn->dn_nblkptr, >=, 1); 145 ASSERT3U(dn->dn_nblkptr, <=, DN_MAX_NBLKPTR); 146 ASSERT3U(dn->dn_bonuslen, <=, DN_MAX_BONUSLEN); 147 ASSERT3U(dn->dn_datablksz, ==, 148 dn->dn_datablkszsec << SPA_MINBLOCKSHIFT); 149 ASSERT3U(ISP2(dn->dn_datablksz), ==, dn->dn_datablkshift != 0); 150 ASSERT3U((dn->dn_nblkptr - 1) * sizeof (blkptr_t) + 151 dn->dn_bonuslen, <=, DN_MAX_BONUSLEN); 152 for (i = 0; i < TXG_SIZE; i++) { 153 ASSERT3U(dn->dn_next_nlevels[i], <=, dn->dn_nlevels); 154 } 155 } 156 if (dn->dn_phys->dn_type != DMU_OT_NONE) 157 ASSERT3U(dn->dn_phys->dn_nlevels, <=, dn->dn_nlevels); 158 ASSERT(dn->dn_object == DMU_META_DNODE_OBJECT || dn->dn_dbuf != NULL); 159 if (dn->dn_dbuf != NULL) { 160 ASSERT3P(dn->dn_phys, ==, 161 (dnode_phys_t *)dn->dn_dbuf->db.db_data + 162 (dn->dn_object % (dn->dn_dbuf->db.db_size >> DNODE_SHIFT))); 163 } 164 if (drop_struct_lock) 165 rw_exit(&dn->dn_struct_rwlock); 166 } 167 #endif 168 169 void 170 dnode_byteswap(dnode_phys_t *dnp) 171 { 172 uint64_t *buf64 = (void*)&dnp->dn_blkptr; 173 int i; 174 175 if (dnp->dn_type == DMU_OT_NONE) { 176 bzero(dnp, sizeof (dnode_phys_t)); 177 return; 178 } 179 180 dnp->dn_datablkszsec = BSWAP_16(dnp->dn_datablkszsec); 181 dnp->dn_bonuslen = BSWAP_16(dnp->dn_bonuslen); 182 dnp->dn_maxblkid = BSWAP_64(dnp->dn_maxblkid); 183 dnp->dn_used = BSWAP_64(dnp->dn_used); 184 185 /* 186 * dn_nblkptr is only one byte, so it's OK to read it in either 187 * byte order. We can't read dn_bouslen. 188 */ 189 ASSERT(dnp->dn_indblkshift <= SPA_MAXBLOCKSHIFT); 190 ASSERT(dnp->dn_nblkptr <= DN_MAX_NBLKPTR); 191 for (i = 0; i < dnp->dn_nblkptr * sizeof (blkptr_t)/8; i++) 192 buf64[i] = BSWAP_64(buf64[i]); 193 194 /* 195 * OK to check dn_bonuslen for zero, because it won't matter if 196 * we have the wrong byte order. This is necessary because the 197 * dnode dnode is smaller than a regular dnode. 198 */ 199 if (dnp->dn_bonuslen != 0) { 200 /* 201 * Note that the bonus length calculated here may be 202 * longer than the actual bonus buffer. This is because 203 * we always put the bonus buffer after the last block 204 * pointer (instead of packing it against the end of the 205 * dnode buffer). 206 */ 207 int off = (dnp->dn_nblkptr-1) * sizeof (blkptr_t); 208 size_t len = DN_MAX_BONUSLEN - off; 209 dmu_ot[dnp->dn_bonustype].ot_byteswap(dnp->dn_bonus + off, len); 210 } 211 } 212 213 void 214 dnode_buf_byteswap(void *vbuf, size_t size) 215 { 216 dnode_phys_t *buf = vbuf; 217 int i; 218 219 ASSERT3U(sizeof (dnode_phys_t), ==, (1<<DNODE_SHIFT)); 220 ASSERT((size & (sizeof (dnode_phys_t)-1)) == 0); 221 222 size >>= DNODE_SHIFT; 223 for (i = 0; i < size; i++) { 224 dnode_byteswap(buf); 225 buf++; 226 } 227 } 228 229 static int 230 free_range_compar(const void *node1, const void *node2) 231 { 232 const free_range_t *rp1 = node1; 233 const free_range_t *rp2 = node2; 234 235 if (rp1->fr_blkid < rp2->fr_blkid) 236 return (-1); 237 else if (rp1->fr_blkid > rp2->fr_blkid) 238 return (1); 239 else return (0); 240 } 241 242 static void 243 dnode_setdblksz(dnode_t *dn, int size) 244 { 245 ASSERT3U(P2PHASE(size, SPA_MINBLOCKSIZE), ==, 0); 246 ASSERT3U(size, <=, SPA_MAXBLOCKSIZE); 247 ASSERT3U(size, >=, SPA_MINBLOCKSIZE); 248 ASSERT3U(size >> SPA_MINBLOCKSHIFT, <, 249 1<<(sizeof (dn->dn_phys->dn_datablkszsec) * 8)); 250 dn->dn_datablksz = size; 251 dn->dn_datablkszsec = size >> SPA_MINBLOCKSHIFT; 252 dn->dn_datablkshift = ISP2(size) ? highbit(size - 1) : 0; 253 } 254 255 static dnode_t * 256 dnode_create(objset_impl_t *os, dnode_phys_t *dnp, dmu_buf_impl_t *db, 257 uint64_t object) 258 { 259 dnode_t *dn = kmem_cache_alloc(dnode_cache, KM_SLEEP); 260 (void) dnode_cons(dn, NULL, 0); /* XXX */ 261 262 dn->dn_objset = os; 263 dn->dn_object = object; 264 dn->dn_dbuf = db; 265 dn->dn_phys = dnp; 266 267 if (dnp->dn_datablkszsec) 268 dnode_setdblksz(dn, dnp->dn_datablkszsec << SPA_MINBLOCKSHIFT); 269 dn->dn_indblkshift = dnp->dn_indblkshift; 270 dn->dn_nlevels = dnp->dn_nlevels; 271 dn->dn_type = dnp->dn_type; 272 dn->dn_nblkptr = dnp->dn_nblkptr; 273 dn->dn_checksum = dnp->dn_checksum; 274 dn->dn_compress = dnp->dn_compress; 275 dn->dn_bonustype = dnp->dn_bonustype; 276 dn->dn_bonuslen = dnp->dn_bonuslen; 277 dn->dn_maxblkid = dnp->dn_maxblkid; 278 279 dmu_zfetch_init(&dn->dn_zfetch, dn); 280 281 ASSERT(dn->dn_phys->dn_type < DMU_OT_NUMTYPES); 282 mutex_enter(&os->os_lock); 283 list_insert_head(&os->os_dnodes, dn); 284 mutex_exit(&os->os_lock); 285 286 return (dn); 287 } 288 289 static void 290 dnode_destroy(dnode_t *dn) 291 { 292 objset_impl_t *os = dn->dn_objset; 293 294 #ifdef ZFS_DEBUG 295 int i; 296 297 for (i = 0; i < TXG_SIZE; i++) { 298 ASSERT(!list_link_active(&dn->dn_dirty_link[i])); 299 ASSERT(NULL == list_head(&dn->dn_dirty_dbufs[i])); 300 ASSERT(0 == avl_numnodes(&dn->dn_ranges[i])); 301 } 302 ASSERT(NULL == list_head(&dn->dn_dbufs)); 303 #endif 304 305 mutex_enter(&os->os_lock); 306 list_remove(&os->os_dnodes, dn); 307 mutex_exit(&os->os_lock); 308 309 if (dn->dn_dirtyctx_firstset) { 310 kmem_free(dn->dn_dirtyctx_firstset, 1); 311 dn->dn_dirtyctx_firstset = NULL; 312 } 313 dmu_zfetch_rele(&dn->dn_zfetch); 314 if (dn->dn_bonus) { 315 mutex_enter(&dn->dn_bonus->db_mtx); 316 dbuf_evict(dn->dn_bonus); 317 dn->dn_bonus = NULL; 318 } 319 kmem_cache_free(dnode_cache, dn); 320 } 321 322 void 323 dnode_allocate(dnode_t *dn, dmu_object_type_t ot, int blocksize, int ibs, 324 dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx) 325 { 326 int i; 327 328 if (blocksize == 0) 329 blocksize = 1 << zfs_default_bs; 330 else if (blocksize > SPA_MAXBLOCKSIZE) 331 blocksize = SPA_MAXBLOCKSIZE; 332 else 333 blocksize = P2ROUNDUP(blocksize, SPA_MINBLOCKSIZE); 334 335 if (ibs == 0) 336 ibs = zfs_default_ibs; 337 338 ibs = MIN(MAX(ibs, DN_MIN_INDBLKSHIFT), DN_MAX_INDBLKSHIFT); 339 340 dprintf("os=%p obj=%llu txg=%llu blocksize=%d ibs=%d\n", dn->dn_objset, 341 dn->dn_object, tx->tx_txg, blocksize, ibs); 342 343 ASSERT(dn->dn_type == DMU_OT_NONE); 344 ASSERT(bcmp(dn->dn_phys, &dnode_phys_zero, sizeof (dnode_phys_t)) == 0); 345 ASSERT(dn->dn_phys->dn_type == DMU_OT_NONE); 346 ASSERT(ot != DMU_OT_NONE); 347 ASSERT3U(ot, <, DMU_OT_NUMTYPES); 348 ASSERT((bonustype == DMU_OT_NONE && bonuslen == 0) || 349 (bonustype != DMU_OT_NONE && bonuslen != 0)); 350 ASSERT3U(bonustype, <, DMU_OT_NUMTYPES); 351 ASSERT3U(bonuslen, <=, DN_MAX_BONUSLEN); 352 ASSERT(dn->dn_type == DMU_OT_NONE); 353 ASSERT3U(dn->dn_maxblkid, ==, 0); 354 ASSERT3U(dn->dn_allocated_txg, ==, 0); 355 ASSERT3U(dn->dn_assigned_txg, ==, 0); 356 ASSERT(refcount_is_zero(&dn->dn_tx_holds)); 357 ASSERT3U(refcount_count(&dn->dn_holds), <=, 1); 358 ASSERT3P(list_head(&dn->dn_dbufs), ==, NULL); 359 360 for (i = 0; i < TXG_SIZE; i++) { 361 ASSERT3U(dn->dn_next_nlevels[i], ==, 0); 362 ASSERT3U(dn->dn_next_indblkshift[i], ==, 0); 363 ASSERT3U(dn->dn_next_blksz[i], ==, 0); 364 ASSERT(!list_link_active(&dn->dn_dirty_link[i])); 365 ASSERT3P(list_head(&dn->dn_dirty_dbufs[i]), ==, NULL); 366 ASSERT3U(avl_numnodes(&dn->dn_ranges[i]), ==, 0); 367 } 368 369 dn->dn_type = ot; 370 dnode_setdblksz(dn, blocksize); 371 dn->dn_indblkshift = ibs; 372 dn->dn_nlevels = 1; 373 dn->dn_nblkptr = 1 + ((DN_MAX_BONUSLEN - bonuslen) >> SPA_BLKPTRSHIFT); 374 dn->dn_bonustype = bonustype; 375 dn->dn_bonuslen = bonuslen; 376 dn->dn_checksum = ZIO_CHECKSUM_INHERIT; 377 dn->dn_compress = ZIO_COMPRESS_INHERIT; 378 dn->dn_dirtyctx = 0; 379 380 dn->dn_free_txg = 0; 381 if (dn->dn_dirtyctx_firstset) { 382 kmem_free(dn->dn_dirtyctx_firstset, 1); 383 dn->dn_dirtyctx_firstset = NULL; 384 } 385 386 dn->dn_allocated_txg = tx->tx_txg; 387 388 dnode_setdirty(dn, tx); 389 dn->dn_next_indblkshift[tx->tx_txg & TXG_MASK] = ibs; 390 dn->dn_next_blksz[tx->tx_txg & TXG_MASK] = dn->dn_datablksz; 391 } 392 393 void 394 dnode_reallocate(dnode_t *dn, dmu_object_type_t ot, int blocksize, 395 dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx) 396 { 397 int i; 398 399 ASSERT3U(blocksize, >=, SPA_MINBLOCKSIZE); 400 ASSERT3U(blocksize, <=, SPA_MAXBLOCKSIZE); 401 ASSERT3U(blocksize % SPA_MINBLOCKSIZE, ==, 0); 402 ASSERT(dn->dn_object != DMU_META_DNODE_OBJECT || dmu_tx_private_ok(tx)); 403 ASSERT(tx->tx_txg != 0); 404 ASSERT((bonustype == DMU_OT_NONE && bonuslen == 0) || 405 (bonustype != DMU_OT_NONE && bonuslen != 0)); 406 ASSERT3U(bonustype, <, DMU_OT_NUMTYPES); 407 ASSERT3U(bonuslen, <=, DN_MAX_BONUSLEN); 408 409 for (i = 0; i < TXG_SIZE; i++) 410 ASSERT(!list_link_active(&dn->dn_dirty_link[i])); 411 412 /* clean up any unreferenced dbufs */ 413 (void) dnode_evict_dbufs(dn, 0); 414 ASSERT3P(list_head(&dn->dn_dbufs), ==, NULL); 415 416 /* 417 * XXX I should really have a generation number to tell if we 418 * need to do this... 419 */ 420 if (blocksize != dn->dn_datablksz || 421 dn->dn_bonustype != bonustype || dn->dn_bonuslen != bonuslen) { 422 /* free all old data */ 423 dnode_free_range(dn, 0, -1ULL, tx); 424 } 425 426 /* change blocksize */ 427 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 428 dnode_setdblksz(dn, blocksize); 429 dnode_setdirty(dn, tx); 430 dn->dn_next_blksz[tx->tx_txg&TXG_MASK] = blocksize; 431 rw_exit(&dn->dn_struct_rwlock); 432 433 /* change type */ 434 dn->dn_type = ot; 435 436 if (dn->dn_bonuslen != bonuslen) { 437 dmu_buf_impl_t *db = NULL; 438 439 /* change bonus size */ 440 if (bonuslen == 0) 441 bonuslen = 1; /* XXX */ 442 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 443 if (dn->dn_bonus == NULL) 444 dn->dn_bonus = dbuf_create_bonus(dn); 445 db = dn->dn_bonus; 446 rw_exit(&dn->dn_struct_rwlock); 447 if (refcount_add(&db->db_holds, FTAG) == 1) 448 dnode_add_ref(dn, db); 449 VERIFY(0 == dbuf_read(db, NULL, DB_RF_MUST_SUCCEED)); 450 mutex_enter(&db->db_mtx); 451 ASSERT3U(db->db.db_size, ==, dn->dn_bonuslen); 452 ASSERT(db->db.db_data != NULL); 453 db->db.db_size = bonuslen; 454 mutex_exit(&db->db_mtx); 455 dbuf_dirty(db, tx); 456 dbuf_rele(db, FTAG); 457 } 458 459 /* change bonus size and type */ 460 mutex_enter(&dn->dn_mtx); 461 dn->dn_bonustype = bonustype; 462 dn->dn_bonuslen = bonuslen; 463 dn->dn_nblkptr = 1 + ((DN_MAX_BONUSLEN - bonuslen) >> SPA_BLKPTRSHIFT); 464 dn->dn_checksum = ZIO_CHECKSUM_INHERIT; 465 dn->dn_compress = ZIO_COMPRESS_INHERIT; 466 ASSERT3U(dn->dn_nblkptr, <=, DN_MAX_NBLKPTR); 467 468 dn->dn_allocated_txg = tx->tx_txg; 469 mutex_exit(&dn->dn_mtx); 470 } 471 472 void 473 dnode_special_close(dnode_t *dn) 474 { 475 /* 476 * Wait for final references to the dnode to clear. This can 477 * only happen if the arc is asyncronously evicting state that 478 * has a hold on this dnode while we are trying to evict this 479 * dnode. 480 */ 481 while (refcount_count(&dn->dn_holds) > 0) 482 delay(1); 483 dnode_destroy(dn); 484 } 485 486 dnode_t * 487 dnode_special_open(objset_impl_t *os, dnode_phys_t *dnp, uint64_t object) 488 { 489 dnode_t *dn = dnode_create(os, dnp, NULL, object); 490 DNODE_VERIFY(dn); 491 return (dn); 492 } 493 494 static void 495 dnode_buf_pageout(dmu_buf_t *db, void *arg) 496 { 497 dnode_t **children_dnodes = arg; 498 int i; 499 int epb = db->db_size >> DNODE_SHIFT; 500 501 for (i = 0; i < epb; i++) { 502 dnode_t *dn = children_dnodes[i]; 503 int n; 504 505 if (dn == NULL) 506 continue; 507 #ifdef ZFS_DEBUG 508 /* 509 * If there are holds on this dnode, then there should 510 * be holds on the dnode's containing dbuf as well; thus 511 * it wouldn't be eligable for eviction and this function 512 * would not have been called. 513 */ 514 ASSERT(refcount_is_zero(&dn->dn_holds)); 515 ASSERT(list_head(&dn->dn_dbufs) == NULL); 516 ASSERT(refcount_is_zero(&dn->dn_tx_holds)); 517 518 for (n = 0; n < TXG_SIZE; n++) 519 ASSERT(!list_link_active(&dn->dn_dirty_link[n])); 520 #endif 521 children_dnodes[i] = NULL; 522 dnode_destroy(dn); 523 } 524 kmem_free(children_dnodes, epb * sizeof (dnode_t *)); 525 } 526 527 /* 528 * errors: 529 * EINVAL - invalid object number. 530 * EIO - i/o error. 531 * succeeds even for free dnodes. 532 */ 533 int 534 dnode_hold_impl(objset_impl_t *os, uint64_t object, int flag, 535 void *tag, dnode_t **dnp) 536 { 537 int epb, idx, err; 538 int drop_struct_lock = FALSE; 539 int type; 540 uint64_t blk; 541 dnode_t *mdn, *dn; 542 dmu_buf_impl_t *db; 543 dnode_t **children_dnodes; 544 545 if (object == 0 || object >= DN_MAX_OBJECT) 546 return (EINVAL); 547 548 mdn = os->os_meta_dnode; 549 550 DNODE_VERIFY(mdn); 551 552 if (!RW_WRITE_HELD(&mdn->dn_struct_rwlock)) { 553 rw_enter(&mdn->dn_struct_rwlock, RW_READER); 554 drop_struct_lock = TRUE; 555 } 556 557 blk = dbuf_whichblock(mdn, object * sizeof (dnode_phys_t)); 558 559 db = dbuf_hold(mdn, blk, FTAG); 560 if (drop_struct_lock) 561 rw_exit(&mdn->dn_struct_rwlock); 562 if (db == NULL) 563 return (EIO); 564 err = dbuf_read(db, NULL, DB_RF_CANFAIL); 565 if (err) { 566 dbuf_rele(db, FTAG); 567 return (err); 568 } 569 570 ASSERT3U(db->db.db_size, >=, 1<<DNODE_SHIFT); 571 epb = db->db.db_size >> DNODE_SHIFT; 572 573 idx = object & (epb-1); 574 575 children_dnodes = dmu_buf_get_user(&db->db); 576 if (children_dnodes == NULL) { 577 dnode_t **winner; 578 children_dnodes = kmem_zalloc(epb * sizeof (dnode_t *), 579 KM_SLEEP); 580 if (winner = dmu_buf_set_user(&db->db, children_dnodes, NULL, 581 dnode_buf_pageout)) { 582 kmem_free(children_dnodes, epb * sizeof (dnode_t *)); 583 children_dnodes = winner; 584 } 585 } 586 587 if ((dn = children_dnodes[idx]) == NULL) { 588 dnode_t *winner; 589 dn = dnode_create(os, (dnode_phys_t *)db->db.db_data+idx, 590 db, object); 591 winner = atomic_cas_ptr(&children_dnodes[idx], NULL, dn); 592 if (winner != NULL) { 593 dnode_destroy(dn); 594 dn = winner; 595 } 596 } 597 598 mutex_enter(&dn->dn_mtx); 599 type = dn->dn_type; 600 if (dn->dn_free_txg || 601 ((flag & DNODE_MUST_BE_ALLOCATED) && type == DMU_OT_NONE) || 602 ((flag & DNODE_MUST_BE_FREE) && type != DMU_OT_NONE)) { 603 mutex_exit(&dn->dn_mtx); 604 dbuf_rele(db, FTAG); 605 return (type == DMU_OT_NONE ? ENOENT : EEXIST); 606 } 607 mutex_exit(&dn->dn_mtx); 608 609 if (refcount_add(&dn->dn_holds, tag) == 1) 610 dbuf_add_ref(db, dn); 611 612 DNODE_VERIFY(dn); 613 ASSERT3P(dn->dn_dbuf, ==, db); 614 ASSERT3U(dn->dn_object, ==, object); 615 dbuf_rele(db, FTAG); 616 617 *dnp = dn; 618 return (0); 619 } 620 621 /* 622 * Return held dnode if the object is allocated, NULL if not. 623 */ 624 int 625 dnode_hold(objset_impl_t *os, uint64_t object, void *tag, dnode_t **dnp) 626 { 627 return (dnode_hold_impl(os, object, DNODE_MUST_BE_ALLOCATED, tag, dnp)); 628 } 629 630 void 631 dnode_add_ref(dnode_t *dn, void *tag) 632 { 633 ASSERT(refcount_count(&dn->dn_holds) > 0); 634 (void) refcount_add(&dn->dn_holds, tag); 635 } 636 637 void 638 dnode_rele(dnode_t *dn, void *tag) 639 { 640 uint64_t refs; 641 642 refs = refcount_remove(&dn->dn_holds, tag); 643 /* NOTE: the DNODE_DNODE does not have a dn_dbuf */ 644 if (refs == 0 && dn->dn_dbuf) 645 dbuf_rele(dn->dn_dbuf, dn); 646 } 647 648 void 649 dnode_setdirty(dnode_t *dn, dmu_tx_t *tx) 650 { 651 objset_impl_t *os = dn->dn_objset; 652 uint64_t txg = tx->tx_txg; 653 654 if (dn->dn_object == DMU_META_DNODE_OBJECT) 655 return; 656 657 DNODE_VERIFY(dn); 658 659 #ifdef ZFS_DEBUG 660 mutex_enter(&dn->dn_mtx); 661 ASSERT(dn->dn_phys->dn_type || dn->dn_allocated_txg); 662 /* ASSERT(dn->dn_free_txg == 0 || dn->dn_free_txg >= txg); */ 663 mutex_exit(&dn->dn_mtx); 664 #endif 665 666 mutex_enter(&os->os_lock); 667 668 /* 669 * If we are already marked dirty, we're done. 670 */ 671 if (list_link_active(&dn->dn_dirty_link[txg & TXG_MASK])) { 672 mutex_exit(&os->os_lock); 673 return; 674 } 675 676 ASSERT(!refcount_is_zero(&dn->dn_holds) || list_head(&dn->dn_dbufs)); 677 ASSERT(dn->dn_datablksz != 0); 678 ASSERT3U(dn->dn_next_blksz[txg&TXG_MASK], ==, 0); 679 680 dprintf_ds(os->os_dsl_dataset, "obj=%llu txg=%llu\n", 681 dn->dn_object, txg); 682 683 if (dn->dn_free_txg > 0 && dn->dn_free_txg <= txg) { 684 list_insert_tail(&os->os_free_dnodes[txg&TXG_MASK], dn); 685 } else { 686 list_insert_tail(&os->os_dirty_dnodes[txg&TXG_MASK], dn); 687 } 688 689 mutex_exit(&os->os_lock); 690 691 /* 692 * The dnode maintains a hold on its containing dbuf as 693 * long as there are holds on it. Each instantiated child 694 * dbuf maintaines a hold on the dnode. When the last child 695 * drops its hold, the dnode will drop its hold on the 696 * containing dbuf. We add a "dirty hold" here so that the 697 * dnode will hang around after we finish processing its 698 * children. 699 */ 700 dnode_add_ref(dn, (void *)(uintptr_t)tx->tx_txg); 701 702 dbuf_dirty(dn->dn_dbuf, tx); 703 704 dsl_dataset_dirty(os->os_dsl_dataset, tx); 705 } 706 707 void 708 dnode_free(dnode_t *dn, dmu_tx_t *tx) 709 { 710 int txgoff = tx->tx_txg & TXG_MASK; 711 712 dprintf("dn=%p txg=%llu\n", dn, tx->tx_txg); 713 714 /* we should be the only holder... hopefully */ 715 /* ASSERT3U(refcount_count(&dn->dn_holds), ==, 1); */ 716 717 mutex_enter(&dn->dn_mtx); 718 if (dn->dn_type == DMU_OT_NONE || dn->dn_free_txg) { 719 mutex_exit(&dn->dn_mtx); 720 return; 721 } 722 dn->dn_free_txg = tx->tx_txg; 723 mutex_exit(&dn->dn_mtx); 724 725 /* 726 * If the dnode is already dirty, it needs to be moved from 727 * the dirty list to the free list. 728 */ 729 mutex_enter(&dn->dn_objset->os_lock); 730 if (list_link_active(&dn->dn_dirty_link[txgoff])) { 731 list_remove(&dn->dn_objset->os_dirty_dnodes[txgoff], dn); 732 list_insert_tail(&dn->dn_objset->os_free_dnodes[txgoff], dn); 733 mutex_exit(&dn->dn_objset->os_lock); 734 } else { 735 mutex_exit(&dn->dn_objset->os_lock); 736 dnode_setdirty(dn, tx); 737 } 738 } 739 740 /* 741 * Try to change the block size for the indicated dnode. This can only 742 * succeed if there are no blocks allocated or dirty beyond first block 743 */ 744 int 745 dnode_set_blksz(dnode_t *dn, uint64_t size, int ibs, dmu_tx_t *tx) 746 { 747 dmu_buf_impl_t *db, *db_next; 748 int have_db0 = FALSE; 749 750 if (size == 0) 751 size = SPA_MINBLOCKSIZE; 752 if (size > SPA_MAXBLOCKSIZE) 753 size = SPA_MAXBLOCKSIZE; 754 else 755 size = P2ROUNDUP(size, SPA_MINBLOCKSIZE); 756 757 if (ibs == dn->dn_indblkshift) 758 ibs = 0; 759 760 if (size >> SPA_MINBLOCKSHIFT == dn->dn_datablkszsec && ibs == 0) 761 return (0); 762 763 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 764 765 /* Check for any allocated blocks beyond the first */ 766 if (dn->dn_phys->dn_maxblkid != 0) 767 goto fail; 768 769 mutex_enter(&dn->dn_dbufs_mtx); 770 for (db = list_head(&dn->dn_dbufs); db; db = db_next) { 771 db_next = list_next(&dn->dn_dbufs, db); 772 773 if (db->db_blkid == 0) { 774 have_db0 = TRUE; 775 } else if (db->db_blkid != DB_BONUS_BLKID) { 776 mutex_exit(&dn->dn_dbufs_mtx); 777 goto fail; 778 } 779 } 780 mutex_exit(&dn->dn_dbufs_mtx); 781 782 if (ibs && dn->dn_nlevels != 1) 783 goto fail; 784 785 db = NULL; 786 if (!BP_IS_HOLE(&dn->dn_phys->dn_blkptr[0]) || have_db0) { 787 /* obtain the old block */ 788 db = dbuf_hold(dn, 0, FTAG); 789 dbuf_new_size(db, size, tx); 790 } 791 792 dnode_setdblksz(dn, size); 793 dnode_setdirty(dn, tx); 794 dn->dn_next_blksz[tx->tx_txg&TXG_MASK] = size; 795 if (ibs) { 796 dn->dn_indblkshift = ibs; 797 dn->dn_next_indblkshift[tx->tx_txg&TXG_MASK] = ibs; 798 } 799 800 if (db) 801 dbuf_rele(db, FTAG); 802 803 rw_exit(&dn->dn_struct_rwlock); 804 return (0); 805 806 fail: 807 rw_exit(&dn->dn_struct_rwlock); 808 return (ENOTSUP); 809 } 810 811 void 812 dnode_new_blkid(dnode_t *dn, uint64_t blkid, dmu_tx_t *tx) 813 { 814 uint64_t txgoff = tx->tx_txg & TXG_MASK; 815 int drop_struct_lock = FALSE; 816 int epbs, new_nlevels; 817 uint64_t sz; 818 819 ASSERT(blkid != DB_BONUS_BLKID); 820 821 if (!RW_WRITE_HELD(&dn->dn_struct_rwlock)) { 822 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 823 drop_struct_lock = TRUE; 824 } 825 826 if (blkid <= dn->dn_maxblkid) 827 goto out; 828 829 dn->dn_maxblkid = blkid; 830 831 /* 832 * Compute the number of levels necessary to support the new maxblkid. 833 */ 834 new_nlevels = 1; 835 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT; 836 for (sz = dn->dn_nblkptr; 837 sz <= blkid && sz >= dn->dn_nblkptr; sz <<= epbs) 838 new_nlevels++; 839 840 if (new_nlevels > dn->dn_nlevels) { 841 int old_nlevels = dn->dn_nlevels; 842 dmu_buf_impl_t *db; 843 844 dn->dn_nlevels = new_nlevels; 845 846 ASSERT3U(new_nlevels, >, dn->dn_next_nlevels[txgoff]); 847 dn->dn_next_nlevels[txgoff] = new_nlevels; 848 849 /* Dirty the left indirects. */ 850 db = dbuf_hold_level(dn, old_nlevels, 0, FTAG); 851 dbuf_dirty(db, tx); 852 dbuf_rele(db, FTAG); 853 854 } 855 856 out: 857 if (drop_struct_lock) 858 rw_exit(&dn->dn_struct_rwlock); 859 } 860 861 void 862 dnode_clear_range(dnode_t *dn, uint64_t blkid, uint64_t nblks, dmu_tx_t *tx) 863 { 864 avl_tree_t *tree = &dn->dn_ranges[tx->tx_txg&TXG_MASK]; 865 avl_index_t where; 866 free_range_t *rp; 867 free_range_t rp_tofind; 868 uint64_t endblk = blkid + nblks; 869 870 ASSERT(MUTEX_HELD(&dn->dn_mtx)); 871 ASSERT(nblks <= UINT64_MAX - blkid); /* no overflow */ 872 873 dprintf_dnode(dn, "blkid=%llu nblks=%llu txg=%llu\n", 874 blkid, nblks, tx->tx_txg); 875 rp_tofind.fr_blkid = blkid; 876 rp = avl_find(tree, &rp_tofind, &where); 877 if (rp == NULL) 878 rp = avl_nearest(tree, where, AVL_BEFORE); 879 if (rp == NULL) 880 rp = avl_nearest(tree, where, AVL_AFTER); 881 882 while (rp && (rp->fr_blkid <= blkid + nblks)) { 883 uint64_t fr_endblk = rp->fr_blkid + rp->fr_nblks; 884 free_range_t *nrp = AVL_NEXT(tree, rp); 885 886 if (blkid <= rp->fr_blkid && endblk >= fr_endblk) { 887 /* clear this entire range */ 888 avl_remove(tree, rp); 889 kmem_free(rp, sizeof (free_range_t)); 890 } else if (blkid <= rp->fr_blkid && 891 endblk > rp->fr_blkid && endblk < fr_endblk) { 892 /* clear the beginning of this range */ 893 rp->fr_blkid = endblk; 894 rp->fr_nblks = fr_endblk - endblk; 895 } else if (blkid > rp->fr_blkid && blkid < fr_endblk && 896 endblk >= fr_endblk) { 897 /* clear the end of this range */ 898 rp->fr_nblks = blkid - rp->fr_blkid; 899 } else if (blkid > rp->fr_blkid && endblk < fr_endblk) { 900 /* clear a chunk out of this range */ 901 free_range_t *new_rp = 902 kmem_alloc(sizeof (free_range_t), KM_SLEEP); 903 904 new_rp->fr_blkid = endblk; 905 new_rp->fr_nblks = fr_endblk - endblk; 906 avl_insert_here(tree, new_rp, rp, AVL_AFTER); 907 rp->fr_nblks = blkid - rp->fr_blkid; 908 } 909 /* there may be no overlap */ 910 rp = nrp; 911 } 912 } 913 914 void 915 dnode_free_range(dnode_t *dn, uint64_t off, uint64_t len, dmu_tx_t *tx) 916 { 917 dmu_buf_impl_t *db; 918 uint64_t blkoff, blkid, nblks; 919 int blksz, head; 920 int trunc = FALSE; 921 922 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 923 blksz = dn->dn_datablksz; 924 925 /* If the range is past the end of the file, this is a no-op */ 926 if (off >= blksz * (dn->dn_maxblkid+1)) 927 goto out; 928 if (len == -1ULL) { 929 len = UINT64_MAX - off; 930 trunc = TRUE; 931 } 932 933 /* 934 * First, block align the region to free: 935 */ 936 if (ISP2(blksz)) { 937 head = P2NPHASE(off, blksz); 938 blkoff = P2PHASE(off, blksz); 939 } else { 940 ASSERT(dn->dn_maxblkid == 0); 941 if (off == 0 && len >= blksz) { 942 /* Freeing the whole block; don't do any head. */ 943 head = 0; 944 } else { 945 /* Freeing part of the block. */ 946 head = blksz - off; 947 ASSERT3U(head, >, 0); 948 } 949 blkoff = off; 950 } 951 /* zero out any partial block data at the start of the range */ 952 if (head) { 953 ASSERT3U(blkoff + head, ==, blksz); 954 if (len < head) 955 head = len; 956 if (dbuf_hold_impl(dn, 0, dbuf_whichblock(dn, off), TRUE, 957 FTAG, &db) == 0) { 958 caddr_t data; 959 960 /* don't dirty if it isn't on disk and isn't dirty */ 961 if (db->db_dirtied || 962 (db->db_blkptr && !BP_IS_HOLE(db->db_blkptr))) { 963 rw_exit(&dn->dn_struct_rwlock); 964 dbuf_will_dirty(db, tx); 965 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 966 data = db->db.db_data; 967 bzero(data + blkoff, head); 968 } 969 dbuf_rele(db, FTAG); 970 } 971 off += head; 972 len -= head; 973 } 974 975 /* If the range was less than one block, we're done */ 976 if (len == 0 || off >= blksz * (dn->dn_maxblkid+1)) 977 goto out; 978 979 if (!ISP2(blksz)) { 980 /* 981 * They are freeing the whole block of a 982 * non-power-of-two blocksize file. Skip all the messy 983 * math. 984 */ 985 ASSERT3U(off, ==, 0); 986 ASSERT3U(len, >=, blksz); 987 blkid = 0; 988 nblks = 1; 989 } else { 990 int tail; 991 int epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT; 992 int blkshift = dn->dn_datablkshift; 993 994 /* If the remaining range is past end of file, we're done */ 995 if (off > dn->dn_maxblkid << blkshift) 996 goto out; 997 998 if (off + len == UINT64_MAX) 999 tail = 0; 1000 else 1001 tail = P2PHASE(len, blksz); 1002 1003 ASSERT3U(P2PHASE(off, blksz), ==, 0); 1004 /* zero out any partial block data at the end of the range */ 1005 if (tail) { 1006 if (len < tail) 1007 tail = len; 1008 if (dbuf_hold_impl(dn, 0, dbuf_whichblock(dn, off+len), 1009 TRUE, FTAG, &db) == 0) { 1010 /* don't dirty if not on disk and not dirty */ 1011 if (db->db_dirtied || 1012 (db->db_blkptr && 1013 !BP_IS_HOLE(db->db_blkptr))) { 1014 rw_exit(&dn->dn_struct_rwlock); 1015 dbuf_will_dirty(db, tx); 1016 rw_enter(&dn->dn_struct_rwlock, 1017 RW_WRITER); 1018 bzero(db->db.db_data, tail); 1019 } 1020 dbuf_rele(db, FTAG); 1021 } 1022 len -= tail; 1023 } 1024 /* If the range did not include a full block, we are done */ 1025 if (len == 0) 1026 goto out; 1027 1028 /* dirty the left indirects */ 1029 if (dn->dn_nlevels > 1 && off != 0) { 1030 db = dbuf_hold_level(dn, 1, 1031 (off - head) >> (blkshift + epbs), FTAG); 1032 dbuf_will_dirty(db, tx); 1033 dbuf_rele(db, FTAG); 1034 } 1035 1036 /* dirty the right indirects */ 1037 if (dn->dn_nlevels > 1 && !trunc) { 1038 db = dbuf_hold_level(dn, 1, 1039 (off + len + tail - 1) >> (blkshift + epbs), FTAG); 1040 dbuf_will_dirty(db, tx); 1041 dbuf_rele(db, FTAG); 1042 } 1043 1044 /* 1045 * Finally, add this range to the dnode range list, we 1046 * will finish up this free operation in the syncing phase. 1047 */ 1048 ASSERT(IS_P2ALIGNED(off, 1<<blkshift)); 1049 ASSERT(off + len == UINT64_MAX || 1050 IS_P2ALIGNED(len, 1<<blkshift)); 1051 blkid = off >> blkshift; 1052 nblks = len >> blkshift; 1053 1054 if (trunc) 1055 dn->dn_maxblkid = (blkid ? blkid - 1 : 0); 1056 } 1057 1058 mutex_enter(&dn->dn_mtx); 1059 dnode_clear_range(dn, blkid, nblks, tx); 1060 { 1061 free_range_t *rp, *found; 1062 avl_index_t where; 1063 avl_tree_t *tree = &dn->dn_ranges[tx->tx_txg&TXG_MASK]; 1064 1065 /* Add new range to dn_ranges */ 1066 rp = kmem_alloc(sizeof (free_range_t), KM_SLEEP); 1067 rp->fr_blkid = blkid; 1068 rp->fr_nblks = nblks; 1069 found = avl_find(tree, rp, &where); 1070 ASSERT(found == NULL); 1071 avl_insert(tree, rp, where); 1072 dprintf_dnode(dn, "blkid=%llu nblks=%llu txg=%llu\n", 1073 blkid, nblks, tx->tx_txg); 1074 } 1075 mutex_exit(&dn->dn_mtx); 1076 1077 dbuf_free_range(dn, blkid, nblks, tx); 1078 dnode_setdirty(dn, tx); 1079 out: 1080 rw_exit(&dn->dn_struct_rwlock); 1081 } 1082 1083 /* return TRUE if this blkid was freed in a recent txg, or FALSE if it wasn't */ 1084 uint64_t 1085 dnode_block_freed(dnode_t *dn, uint64_t blkid) 1086 { 1087 free_range_t range_tofind; 1088 void *dp = spa_get_dsl(dn->dn_objset->os_spa); 1089 int i; 1090 1091 if (blkid == DB_BONUS_BLKID) 1092 return (FALSE); 1093 1094 /* 1095 * If we're in the process of opening the pool, dp will not be 1096 * set yet, but there shouldn't be anything dirty. 1097 */ 1098 if (dp == NULL) 1099 return (FALSE); 1100 1101 if (dn->dn_free_txg) 1102 return (TRUE); 1103 1104 /* 1105 * If dn_datablkshift is not set, then there's only a single 1106 * block, in which case there will never be a free range so it 1107 * won't matter. 1108 */ 1109 range_tofind.fr_blkid = blkid; 1110 mutex_enter(&dn->dn_mtx); 1111 for (i = 0; i < TXG_SIZE; i++) { 1112 free_range_t *range_found; 1113 avl_index_t idx; 1114 1115 range_found = avl_find(&dn->dn_ranges[i], &range_tofind, &idx); 1116 if (range_found) { 1117 ASSERT(range_found->fr_nblks > 0); 1118 break; 1119 } 1120 range_found = avl_nearest(&dn->dn_ranges[i], idx, AVL_BEFORE); 1121 if (range_found && 1122 range_found->fr_blkid + range_found->fr_nblks > blkid) 1123 break; 1124 } 1125 mutex_exit(&dn->dn_mtx); 1126 return (i < TXG_SIZE); 1127 } 1128 1129 /* call from syncing context when we actually write/free space for this dnode */ 1130 void 1131 dnode_diduse_space(dnode_t *dn, int64_t delta) 1132 { 1133 uint64_t space; 1134 dprintf_dnode(dn, "dn=%p dnp=%p used=%llu delta=%lld\n", 1135 dn, dn->dn_phys, 1136 (u_longlong_t)dn->dn_phys->dn_used, 1137 (longlong_t)delta); 1138 1139 mutex_enter(&dn->dn_mtx); 1140 space = DN_USED_BYTES(dn->dn_phys); 1141 if (delta > 0) { 1142 ASSERT3U(space + delta, >=, space); /* no overflow */ 1143 } else { 1144 ASSERT3U(space, >=, -delta); /* no underflow */ 1145 } 1146 space += delta; 1147 if (spa_version(dn->dn_objset->os_spa) < ZFS_VERSION_DNODE_BYTES) { 1148 ASSERT((dn->dn_phys->dn_flags & DNODE_FLAG_USED_BYTES) == 0); 1149 ASSERT3U(P2PHASE(space, 1<<DEV_BSHIFT), ==, 0); 1150 dn->dn_phys->dn_used = space >> DEV_BSHIFT; 1151 } else { 1152 dn->dn_phys->dn_used = space; 1153 dn->dn_phys->dn_flags |= DNODE_FLAG_USED_BYTES; 1154 } 1155 mutex_exit(&dn->dn_mtx); 1156 } 1157 1158 /* 1159 * Call when we think we're going to write/free space in open context. 1160 * Be conservative (ie. OK to write less than this or free more than 1161 * this, but don't write more or free less). 1162 */ 1163 void 1164 dnode_willuse_space(dnode_t *dn, int64_t space, dmu_tx_t *tx) 1165 { 1166 objset_impl_t *os = dn->dn_objset; 1167 dsl_dataset_t *ds = os->os_dsl_dataset; 1168 1169 if (space > 0) 1170 space = spa_get_asize(os->os_spa, space); 1171 1172 if (ds) 1173 dsl_dir_willuse_space(ds->ds_dir, space, tx); 1174 1175 dmu_tx_willuse_space(tx, space); 1176 } 1177 1178 static int 1179 dnode_next_offset_level(dnode_t *dn, boolean_t hole, uint64_t *offset, 1180 int lvl, uint64_t blkfill) 1181 { 1182 dmu_buf_impl_t *db = NULL; 1183 void *data = NULL; 1184 uint64_t epbs = dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT; 1185 uint64_t epb = 1ULL << epbs; 1186 uint64_t minfill, maxfill; 1187 int i, error, span; 1188 1189 dprintf("probing object %llu offset %llx level %d of %u\n", 1190 dn->dn_object, *offset, lvl, dn->dn_phys->dn_nlevels); 1191 1192 if (lvl == dn->dn_phys->dn_nlevels) { 1193 error = 0; 1194 epb = dn->dn_phys->dn_nblkptr; 1195 data = dn->dn_phys->dn_blkptr; 1196 } else { 1197 uint64_t blkid = dbuf_whichblock(dn, *offset) >> (epbs * lvl); 1198 error = dbuf_hold_impl(dn, lvl, blkid, TRUE, FTAG, &db); 1199 if (error) { 1200 if (error == ENOENT) 1201 return (hole ? 0 : ESRCH); 1202 return (error); 1203 } 1204 error = dbuf_read(db, NULL, DB_RF_CANFAIL | DB_RF_HAVESTRUCT); 1205 if (error) { 1206 dbuf_rele(db, FTAG); 1207 return (error); 1208 } 1209 data = db->db.db_data; 1210 } 1211 1212 if (lvl == 0) { 1213 dnode_phys_t *dnp = data; 1214 span = DNODE_SHIFT; 1215 ASSERT(dn->dn_type == DMU_OT_DNODE); 1216 1217 for (i = (*offset >> span) & (blkfill - 1); i < blkfill; i++) { 1218 if (!dnp[i].dn_type == hole) 1219 break; 1220 *offset += 1ULL << span; 1221 } 1222 if (i == blkfill) 1223 error = ESRCH; 1224 } else { 1225 blkptr_t *bp = data; 1226 span = (lvl - 1) * epbs + dn->dn_datablkshift; 1227 minfill = 0; 1228 maxfill = blkfill << ((lvl - 1) * epbs); 1229 1230 if (hole) 1231 maxfill--; 1232 else 1233 minfill++; 1234 1235 for (i = (*offset >> span) & ((1ULL << epbs) - 1); 1236 i < epb; i++) { 1237 if (bp[i].blk_fill >= minfill && 1238 bp[i].blk_fill <= maxfill) 1239 break; 1240 *offset += 1ULL << span; 1241 } 1242 if (i >= epb) 1243 error = ESRCH; 1244 } 1245 1246 if (db) 1247 dbuf_rele(db, FTAG); 1248 1249 return (error); 1250 } 1251 1252 /* 1253 * Find the next hole, data, or sparse region at or after *offset. 1254 * The value 'blkfill' tells us how many items we expect to find 1255 * in an L0 data block; this value is 1 for normal objects, 1256 * DNODES_PER_BLOCK for the meta dnode, and some fraction of 1257 * DNODES_PER_BLOCK when searching for sparse regions thereof. 1258 * Examples: 1259 * 1260 * dnode_next_offset(dn, hole, offset, 1, 1); 1261 * Finds the next hole/data in a file. 1262 * Used in dmu_offset_next(). 1263 * 1264 * dnode_next_offset(mdn, hole, offset, 0, DNODES_PER_BLOCK); 1265 * Finds the next free/allocated dnode an objset's meta-dnode. 1266 * Used in dmu_object_next(). 1267 * 1268 * dnode_next_offset(mdn, TRUE, offset, 2, DNODES_PER_BLOCK >> 2); 1269 * Finds the next L2 meta-dnode bp that's at most 1/4 full. 1270 * Used in dmu_object_alloc(). 1271 */ 1272 int 1273 dnode_next_offset(dnode_t *dn, boolean_t hole, uint64_t *offset, 1274 int minlvl, uint64_t blkfill) 1275 { 1276 int lvl, maxlvl; 1277 int error = 0; 1278 uint64_t initial_offset = *offset; 1279 1280 rw_enter(&dn->dn_struct_rwlock, RW_READER); 1281 1282 if (dn->dn_phys->dn_nlevels == 0) { 1283 rw_exit(&dn->dn_struct_rwlock); 1284 return (ESRCH); 1285 } 1286 1287 if (dn->dn_datablkshift == 0) { 1288 if (*offset < dn->dn_datablksz) { 1289 if (hole) 1290 *offset = dn->dn_datablksz; 1291 } else { 1292 error = ESRCH; 1293 } 1294 rw_exit(&dn->dn_struct_rwlock); 1295 return (error); 1296 } 1297 1298 maxlvl = dn->dn_phys->dn_nlevels; 1299 1300 for (lvl = minlvl; lvl <= maxlvl; lvl++) { 1301 error = dnode_next_offset_level(dn, hole, offset, lvl, blkfill); 1302 if (error != ESRCH) 1303 break; 1304 } 1305 1306 while (--lvl >= minlvl && error == 0) 1307 error = dnode_next_offset_level(dn, hole, offset, lvl, blkfill); 1308 1309 rw_exit(&dn->dn_struct_rwlock); 1310 1311 if (error == 0 && initial_offset > *offset) 1312 error = ESRCH; 1313 1314 return (error); 1315 } 1316