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