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 int err = ENOTSUP; 739 740 if (size == 0) 741 size = SPA_MINBLOCKSIZE; 742 if (size > SPA_MAXBLOCKSIZE) 743 size = SPA_MAXBLOCKSIZE; 744 else 745 size = P2ROUNDUP(size, SPA_MINBLOCKSIZE); 746 747 if (ibs == 0) 748 ibs = dn->dn_indblkshift; 749 750 if (size >> SPA_MINBLOCKSHIFT == dn->dn_datablkszsec && 751 ibs == dn->dn_indblkshift) 752 return (0); 753 754 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 755 756 /* Check for any allocated blocks beyond the first */ 757 if (dn->dn_phys->dn_maxblkid != 0) 758 goto end; 759 760 mutex_enter(&dn->dn_dbufs_mtx); 761 for (db = list_head(&dn->dn_dbufs); db; db = db_next) { 762 db_next = list_next(&dn->dn_dbufs, db); 763 764 if (db->db_blkid == 0) { 765 have_db0 = TRUE; 766 } else if (db->db_blkid != DB_BONUS_BLKID) { 767 mutex_exit(&dn->dn_dbufs_mtx); 768 goto end; 769 } 770 } 771 mutex_exit(&dn->dn_dbufs_mtx); 772 773 db = NULL; 774 if (!BP_IS_HOLE(&dn->dn_phys->dn_blkptr[0]) || have_db0) { 775 /* obtain the old block */ 776 db = dbuf_hold(dn, 0, FTAG); 777 dbuf_new_size(db, size, tx); 778 } 779 780 dnode_setdblksz(dn, size); 781 dn->dn_indblkshift = ibs; 782 dnode_setdirty(dn, tx); 783 dn->dn_next_blksz[tx->tx_txg&TXG_MASK] = size; 784 dn->dn_next_indblkshift[tx->tx_txg&TXG_MASK] = ibs; 785 786 if (db) 787 dbuf_rele(db, FTAG); 788 789 err = 0; 790 end: 791 rw_exit(&dn->dn_struct_rwlock); 792 return (err); 793 } 794 795 uint64_t 796 dnode_max_nonzero_offset(dnode_t *dn) 797 { 798 if (dn->dn_phys->dn_maxblkid == 0 && 799 BP_IS_HOLE(&dn->dn_phys->dn_blkptr[0])) 800 return (0); 801 else 802 return ((dn->dn_phys->dn_maxblkid+1) * dn->dn_datablksz); 803 } 804 805 void 806 dnode_new_blkid(dnode_t *dn, uint64_t blkid, dmu_tx_t *tx) 807 { 808 uint64_t txgoff = tx->tx_txg & TXG_MASK; 809 int drop_struct_lock = FALSE; 810 int epbs, new_nlevels; 811 uint64_t sz; 812 813 ASSERT(blkid != DB_BONUS_BLKID); 814 815 if (!RW_WRITE_HELD(&dn->dn_struct_rwlock)) { 816 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 817 drop_struct_lock = TRUE; 818 } 819 820 if (blkid <= dn->dn_maxblkid) 821 goto out; 822 823 dn->dn_maxblkid = blkid; 824 825 /* 826 * Compute the number of levels necessary to support the new maxblkid. 827 */ 828 new_nlevels = 1; 829 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT; 830 for (sz = dn->dn_nblkptr; 831 sz <= blkid && sz >= dn->dn_nblkptr; sz <<= epbs) 832 new_nlevels++; 833 834 if (new_nlevels > dn->dn_nlevels) { 835 int old_nlevels = dn->dn_nlevels; 836 dmu_buf_impl_t *db; 837 838 dn->dn_nlevels = new_nlevels; 839 840 ASSERT3U(new_nlevels, >, dn->dn_next_nlevels[txgoff]); 841 dn->dn_next_nlevels[txgoff] = new_nlevels; 842 843 /* Dirty the left indirects. */ 844 db = dbuf_hold_level(dn, old_nlevels, 0, FTAG); 845 dbuf_dirty(db, tx); 846 dbuf_rele(db, FTAG); 847 848 } 849 850 out: 851 if (drop_struct_lock) 852 rw_exit(&dn->dn_struct_rwlock); 853 } 854 855 void 856 dnode_clear_range(dnode_t *dn, uint64_t blkid, uint64_t nblks, dmu_tx_t *tx) 857 { 858 avl_tree_t *tree = &dn->dn_ranges[tx->tx_txg&TXG_MASK]; 859 avl_index_t where; 860 free_range_t *rp; 861 free_range_t rp_tofind; 862 uint64_t endblk = blkid + nblks; 863 864 ASSERT(MUTEX_HELD(&dn->dn_mtx)); 865 ASSERT(nblks <= UINT64_MAX - blkid); /* no overflow */ 866 867 dprintf_dnode(dn, "blkid=%llu nblks=%llu txg=%llu\n", 868 blkid, nblks, tx->tx_txg); 869 rp_tofind.fr_blkid = blkid; 870 rp = avl_find(tree, &rp_tofind, &where); 871 if (rp == NULL) 872 rp = avl_nearest(tree, where, AVL_BEFORE); 873 if (rp == NULL) 874 rp = avl_nearest(tree, where, AVL_AFTER); 875 876 while (rp && (rp->fr_blkid <= blkid + nblks)) { 877 uint64_t fr_endblk = rp->fr_blkid + rp->fr_nblks; 878 free_range_t *nrp = AVL_NEXT(tree, rp); 879 880 if (blkid <= rp->fr_blkid && endblk >= fr_endblk) { 881 /* clear this entire range */ 882 avl_remove(tree, rp); 883 kmem_free(rp, sizeof (free_range_t)); 884 } else if (blkid <= rp->fr_blkid && 885 endblk > rp->fr_blkid && endblk < fr_endblk) { 886 /* clear the beginning of this range */ 887 rp->fr_blkid = endblk; 888 rp->fr_nblks = fr_endblk - endblk; 889 } else if (blkid > rp->fr_blkid && blkid < fr_endblk && 890 endblk >= fr_endblk) { 891 /* clear the end of this range */ 892 rp->fr_nblks = blkid - rp->fr_blkid; 893 } else if (blkid > rp->fr_blkid && endblk < fr_endblk) { 894 /* clear a chunk out of this range */ 895 free_range_t *new_rp = 896 kmem_alloc(sizeof (free_range_t), KM_SLEEP); 897 898 new_rp->fr_blkid = endblk; 899 new_rp->fr_nblks = fr_endblk - endblk; 900 avl_insert_here(tree, new_rp, rp, AVL_AFTER); 901 rp->fr_nblks = blkid - rp->fr_blkid; 902 } 903 /* there may be no overlap */ 904 rp = nrp; 905 } 906 } 907 908 void 909 dnode_free_range(dnode_t *dn, uint64_t off, uint64_t len, dmu_tx_t *tx) 910 { 911 dmu_buf_impl_t *db; 912 uint64_t start, objsize, blkid, nblks; 913 int blkshift, blksz, tail, head, epbs; 914 int trunc = FALSE; 915 916 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 917 blksz = dn->dn_datablksz; 918 blkshift = dn->dn_datablkshift; 919 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT; 920 921 /* If the range is past the end of the file, this is a no-op */ 922 objsize = blksz * (dn->dn_maxblkid+1); 923 if (off >= objsize) 924 goto out; 925 if (len == -1ULL) { 926 len = UINT64_MAX - off; 927 trunc = TRUE; 928 } 929 930 /* 931 * First, block align the region to free: 932 */ 933 if (dn->dn_maxblkid == 0) { 934 if (off == 0) { 935 head = 0; 936 } else { 937 head = blksz - off; 938 ASSERT3U(head, >, 0); 939 } 940 start = off; 941 } else { 942 ASSERT(ISP2(blksz)); 943 head = P2NPHASE(off, blksz); 944 start = P2PHASE(off, blksz); 945 } 946 /* zero out any partial block data at the start of the range */ 947 if (head) { 948 ASSERT3U(start + head, ==, blksz); 949 if (len < head) 950 head = len; 951 if (dbuf_hold_impl(dn, 0, dbuf_whichblock(dn, off), TRUE, 952 FTAG, &db) == 0) { 953 caddr_t data; 954 955 /* don't dirty if it isn't on disk and isn't dirty */ 956 if (db->db_dirtied || 957 (db->db_blkptr && !BP_IS_HOLE(db->db_blkptr))) { 958 rw_exit(&dn->dn_struct_rwlock); 959 dbuf_will_dirty(db, tx); 960 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 961 data = db->db.db_data; 962 bzero(data + start, head); 963 } 964 dbuf_rele(db, FTAG); 965 } 966 off += head; 967 len -= head; 968 } 969 /* If the range was less than one block, we are done */ 970 if (len == 0) 971 goto out; 972 973 /* If the remaining range is past the end of the file, we are done */ 974 if (off > dn->dn_maxblkid << blkshift) 975 goto out; 976 977 if (off + len == UINT64_MAX) 978 tail = 0; 979 else 980 tail = P2PHASE(len, blksz); 981 982 ASSERT3U(P2PHASE(off, blksz), ==, 0); 983 /* zero out any partial block data at the end of the range */ 984 if (tail) { 985 if (len < tail) 986 tail = len; 987 if (dbuf_hold_impl(dn, 0, dbuf_whichblock(dn, off+len), 988 TRUE, FTAG, &db) == 0) { 989 /* don't dirty if it isn't on disk and isn't dirty */ 990 if (db->db_dirtied || 991 (db->db_blkptr && !BP_IS_HOLE(db->db_blkptr))) { 992 rw_exit(&dn->dn_struct_rwlock); 993 dbuf_will_dirty(db, tx); 994 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 995 bzero(db->db.db_data, tail); 996 } 997 dbuf_rele(db, FTAG); 998 } 999 len -= tail; 1000 } 1001 /* If the range did not include a full block, we are done */ 1002 if (len == 0) 1003 goto out; 1004 1005 /* dirty the left indirects */ 1006 if (dn->dn_nlevels > 1 && off != 0) { 1007 db = dbuf_hold_level(dn, 1, 1008 (off - head) >> (blkshift + epbs), FTAG); 1009 dbuf_will_dirty(db, tx); 1010 dbuf_rele(db, FTAG); 1011 } 1012 1013 /* dirty the right indirects */ 1014 if (dn->dn_nlevels > 1 && !trunc) { 1015 db = dbuf_hold_level(dn, 1, 1016 (off + len + tail - 1) >> (blkshift + epbs), FTAG); 1017 dbuf_will_dirty(db, tx); 1018 dbuf_rele(db, FTAG); 1019 } 1020 1021 /* 1022 * Finally, add this range to the dnode range list, we 1023 * will finish up this free operation in the syncing phase. 1024 */ 1025 ASSERT(IS_P2ALIGNED(off, 1<<blkshift)); 1026 ASSERT(off + len == UINT64_MAX || IS_P2ALIGNED(len, 1<<blkshift)); 1027 blkid = off >> blkshift; 1028 nblks = len >> blkshift; 1029 1030 if (trunc) 1031 dn->dn_maxblkid = (blkid ? blkid - 1 : 0); 1032 1033 mutex_enter(&dn->dn_mtx); 1034 dnode_clear_range(dn, blkid, nblks, tx); 1035 { 1036 free_range_t *rp, *found; 1037 avl_index_t where; 1038 avl_tree_t *tree = &dn->dn_ranges[tx->tx_txg&TXG_MASK]; 1039 1040 /* Add new range to dn_ranges */ 1041 rp = kmem_alloc(sizeof (free_range_t), KM_SLEEP); 1042 rp->fr_blkid = blkid; 1043 rp->fr_nblks = nblks; 1044 found = avl_find(tree, rp, &where); 1045 ASSERT(found == NULL); 1046 avl_insert(tree, rp, where); 1047 dprintf_dnode(dn, "blkid=%llu nblks=%llu txg=%llu\n", 1048 blkid, nblks, tx->tx_txg); 1049 } 1050 mutex_exit(&dn->dn_mtx); 1051 1052 dbuf_free_range(dn, blkid, nblks, tx); 1053 dnode_setdirty(dn, tx); 1054 out: 1055 rw_exit(&dn->dn_struct_rwlock); 1056 } 1057 1058 /* return TRUE if this blkid was freed in a recent txg, or FALSE if it wasn't */ 1059 uint64_t 1060 dnode_block_freed(dnode_t *dn, uint64_t blkid) 1061 { 1062 free_range_t range_tofind; 1063 void *dp = spa_get_dsl(dn->dn_objset->os_spa); 1064 int i; 1065 1066 if (blkid == DB_BONUS_BLKID) 1067 return (FALSE); 1068 1069 /* 1070 * If we're in the process of opening the pool, dp will not be 1071 * set yet, but there shouldn't be anything dirty. 1072 */ 1073 if (dp == NULL) 1074 return (FALSE); 1075 1076 if (dn->dn_free_txg) 1077 return (TRUE); 1078 1079 /* 1080 * If dn_datablkshift is not set, then there's only a single 1081 * block, in which case there will never be a free range so it 1082 * won't matter. 1083 */ 1084 range_tofind.fr_blkid = blkid; 1085 mutex_enter(&dn->dn_mtx); 1086 for (i = 0; i < TXG_SIZE; i++) { 1087 free_range_t *range_found; 1088 avl_index_t idx; 1089 1090 range_found = avl_find(&dn->dn_ranges[i], &range_tofind, &idx); 1091 if (range_found) { 1092 ASSERT(range_found->fr_nblks > 0); 1093 break; 1094 } 1095 range_found = avl_nearest(&dn->dn_ranges[i], idx, AVL_BEFORE); 1096 if (range_found && 1097 range_found->fr_blkid + range_found->fr_nblks > blkid) 1098 break; 1099 } 1100 mutex_exit(&dn->dn_mtx); 1101 return (i < TXG_SIZE); 1102 } 1103 1104 /* call from syncing context when we actually write/free space for this dnode */ 1105 void 1106 dnode_diduse_space(dnode_t *dn, int64_t delta) 1107 { 1108 uint64_t space; 1109 dprintf_dnode(dn, "dn=%p dnp=%p used=%llu delta=%lld\n", 1110 dn, dn->dn_phys, 1111 (u_longlong_t)dn->dn_phys->dn_used, 1112 (longlong_t)delta); 1113 1114 mutex_enter(&dn->dn_mtx); 1115 space = DN_USED_BYTES(dn->dn_phys); 1116 if (delta > 0) { 1117 ASSERT3U(space + delta, >=, space); /* no overflow */ 1118 } else { 1119 ASSERT3U(space, >=, -delta); /* no underflow */ 1120 } 1121 space += delta; 1122 if (spa_version(dn->dn_objset->os_spa) < ZFS_VERSION_DNODE_BYTES) { 1123 ASSERT((dn->dn_phys->dn_flags & DNODE_FLAG_USED_BYTES) == 0); 1124 ASSERT3U(P2PHASE(space, 1<<DEV_BSHIFT), ==, 0); 1125 dn->dn_phys->dn_used = space >> DEV_BSHIFT; 1126 } else { 1127 dn->dn_phys->dn_used = space; 1128 dn->dn_phys->dn_flags |= DNODE_FLAG_USED_BYTES; 1129 } 1130 mutex_exit(&dn->dn_mtx); 1131 } 1132 1133 /* 1134 * Call when we think we're going to write/free space in open context. 1135 * Be conservative (ie. OK to write less than this or free more than 1136 * this, but don't write more or free less). 1137 */ 1138 void 1139 dnode_willuse_space(dnode_t *dn, int64_t space, dmu_tx_t *tx) 1140 { 1141 objset_impl_t *os = dn->dn_objset; 1142 dsl_dataset_t *ds = os->os_dsl_dataset; 1143 1144 if (space > 0) 1145 space = spa_get_asize(os->os_spa, space); 1146 1147 if (ds) 1148 dsl_dir_willuse_space(ds->ds_dir, space, tx); 1149 1150 dmu_tx_willuse_space(tx, space); 1151 } 1152 1153 static int 1154 dnode_next_offset_level(dnode_t *dn, boolean_t hole, uint64_t *offset, 1155 int lvl, uint64_t blkfill) 1156 { 1157 dmu_buf_impl_t *db = NULL; 1158 void *data = NULL; 1159 uint64_t epbs = dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT; 1160 uint64_t epb = 1ULL << epbs; 1161 uint64_t minfill, maxfill; 1162 int i, error, span; 1163 1164 dprintf("probing object %llu offset %llx level %d of %u\n", 1165 dn->dn_object, *offset, lvl, dn->dn_phys->dn_nlevels); 1166 1167 if (lvl == dn->dn_phys->dn_nlevels) { 1168 error = 0; 1169 epb = dn->dn_phys->dn_nblkptr; 1170 data = dn->dn_phys->dn_blkptr; 1171 } else { 1172 uint64_t blkid = dbuf_whichblock(dn, *offset) >> (epbs * lvl); 1173 error = dbuf_hold_impl(dn, lvl, blkid, TRUE, FTAG, &db); 1174 if (error) { 1175 if (error == ENOENT) 1176 return (hole ? 0 : ESRCH); 1177 return (error); 1178 } 1179 error = dbuf_read(db, NULL, DB_RF_CANFAIL | DB_RF_HAVESTRUCT); 1180 if (error) { 1181 dbuf_rele(db, FTAG); 1182 return (error); 1183 } 1184 data = db->db.db_data; 1185 } 1186 1187 if (lvl == 0) { 1188 dnode_phys_t *dnp = data; 1189 span = DNODE_SHIFT; 1190 ASSERT(dn->dn_type == DMU_OT_DNODE); 1191 1192 for (i = (*offset >> span) & (blkfill - 1); i < blkfill; i++) { 1193 if (!dnp[i].dn_type == hole) 1194 break; 1195 *offset += 1ULL << span; 1196 } 1197 if (i == blkfill) 1198 error = ESRCH; 1199 } else { 1200 blkptr_t *bp = data; 1201 span = (lvl - 1) * epbs + dn->dn_datablkshift; 1202 minfill = 0; 1203 maxfill = blkfill << ((lvl - 1) * epbs); 1204 1205 if (hole) 1206 maxfill--; 1207 else 1208 minfill++; 1209 1210 for (i = (*offset >> span) & ((1ULL << epbs) - 1); 1211 i < epb; i++) { 1212 if (bp[i].blk_fill >= minfill && 1213 bp[i].blk_fill <= maxfill) 1214 break; 1215 *offset += 1ULL << span; 1216 } 1217 if (i >= epb) 1218 error = ESRCH; 1219 } 1220 1221 if (db) 1222 dbuf_rele(db, FTAG); 1223 1224 return (error); 1225 } 1226 1227 /* 1228 * Find the next hole, data, or sparse region at or after *offset. 1229 * The value 'blkfill' tells us how many items we expect to find 1230 * in an L0 data block; this value is 1 for normal objects, 1231 * DNODES_PER_BLOCK for the meta dnode, and some fraction of 1232 * DNODES_PER_BLOCK when searching for sparse regions thereof. 1233 * Examples: 1234 * 1235 * dnode_next_offset(dn, hole, offset, 1, 1); 1236 * Finds the next hole/data in a file. 1237 * Used in dmu_offset_next(). 1238 * 1239 * dnode_next_offset(mdn, hole, offset, 0, DNODES_PER_BLOCK); 1240 * Finds the next free/allocated dnode an objset's meta-dnode. 1241 * Used in dmu_object_next(). 1242 * 1243 * dnode_next_offset(mdn, TRUE, offset, 2, DNODES_PER_BLOCK >> 2); 1244 * Finds the next L2 meta-dnode bp that's at most 1/4 full. 1245 * Used in dmu_object_alloc(). 1246 */ 1247 int 1248 dnode_next_offset(dnode_t *dn, boolean_t hole, uint64_t *offset, 1249 int minlvl, uint64_t blkfill) 1250 { 1251 int lvl, maxlvl; 1252 int error = 0; 1253 uint64_t initial_offset = *offset; 1254 1255 rw_enter(&dn->dn_struct_rwlock, RW_READER); 1256 1257 if (dn->dn_phys->dn_nlevels == 0) { 1258 rw_exit(&dn->dn_struct_rwlock); 1259 return (ESRCH); 1260 } 1261 1262 if (dn->dn_datablkshift == 0) { 1263 if (*offset < dn->dn_datablksz) { 1264 if (hole) 1265 *offset = dn->dn_datablksz; 1266 } else { 1267 error = ESRCH; 1268 } 1269 rw_exit(&dn->dn_struct_rwlock); 1270 return (error); 1271 } 1272 1273 maxlvl = dn->dn_phys->dn_nlevels; 1274 1275 for (lvl = minlvl; lvl <= maxlvl; lvl++) { 1276 error = dnode_next_offset_level(dn, hole, offset, lvl, blkfill); 1277 if (error != ESRCH) 1278 break; 1279 } 1280 1281 while (--lvl >= minlvl && error == 0) 1282 error = dnode_next_offset_level(dn, hole, offset, lvl, blkfill); 1283 1284 rw_exit(&dn->dn_struct_rwlock); 1285 1286 if (error == 0 && initial_offset > *offset) 1287 error = ESRCH; 1288 1289 return (error); 1290 } 1291