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, Version 1.0 only 6 * (the "License"). You may not use this file except in compliance 7 * with the License. 8 * 9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10 * or http://www.opensolaris.org/os/licensing. 11 * See the License for the specific language governing permissions 12 * and limitations under the License. 13 * 14 * When distributing Covered Code, include this CDDL HEADER in each 15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16 * If applicable, add the following below this CDDL HEADER, with the 17 * fields enclosed by brackets "[]" replaced with your own identifying 18 * information: Portions Copyright [yyyy] [name of copyright owner] 19 * 20 * CDDL HEADER END 21 */ 22 /* 23 * Copyright 2005 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 #pragma ident "%Z%%M% %I% %E% SMI" 28 29 #include <sys/zfs_context.h> 30 #include <sys/dbuf.h> 31 #include <sys/dnode.h> 32 #include <sys/dmu.h> 33 #include <sys/dmu_impl.h> 34 #include <sys/dmu_tx.h> 35 #include <sys/dmu_objset.h> 36 #include <sys/dsl_dir.h> 37 #include <sys/dsl_dataset.h> 38 #include <sys/spa.h> 39 #include <sys/zio.h> 40 #include <sys/dmu_zfetch.h> 41 42 static int free_range_compar(const void *node1, const void *node2); 43 44 static kmem_cache_t *dnode_cache; 45 46 static dnode_phys_t dnode_phys_zero; 47 48 int zfs_default_bs = SPA_MINBLOCKSHIFT; 49 int zfs_default_ibs = DN_MAX_INDBLKSHIFT; 50 51 /* ARGSUSED */ 52 static int 53 dnode_cons(void *arg, void *unused, int kmflag) 54 { 55 int i; 56 dnode_t *dn = arg; 57 bzero(dn, sizeof (dnode_t)); 58 59 rw_init(&dn->dn_struct_rwlock, NULL, RW_DEFAULT, NULL); 60 mutex_init(&dn->dn_mtx, NULL, MUTEX_DEFAULT, NULL); 61 mutex_init(&dn->dn_dbufs_mtx, NULL, MUTEX_DEFAULT, NULL); 62 refcount_create(&dn->dn_holds); 63 refcount_create(&dn->dn_tx_holds); 64 65 for (i = 0; i < TXG_SIZE; i++) { 66 avl_create(&dn->dn_ranges[i], free_range_compar, 67 sizeof (free_range_t), 68 offsetof(struct free_range, fr_node)); 69 list_create(&dn->dn_dirty_dbufs[i], 70 sizeof (dmu_buf_impl_t), 71 offsetof(dmu_buf_impl_t, db_dirty_node[i])); 72 } 73 74 list_create(&dn->dn_dbufs, sizeof (dmu_buf_impl_t), 75 offsetof(dmu_buf_impl_t, db_link)); 76 77 return (0); 78 } 79 80 /* ARGSUSED */ 81 static void 82 dnode_dest(void *arg, void *unused) 83 { 84 int i; 85 dnode_t *dn = arg; 86 87 rw_destroy(&dn->dn_struct_rwlock); 88 mutex_destroy(&dn->dn_mtx); 89 mutex_destroy(&dn->dn_dbufs_mtx); 90 refcount_destroy(&dn->dn_holds); 91 refcount_destroy(&dn->dn_tx_holds); 92 93 for (i = 0; i < TXG_SIZE; i++) { 94 avl_destroy(&dn->dn_ranges[i]); 95 list_destroy(&dn->dn_dirty_dbufs[i]); 96 } 97 98 list_destroy(&dn->dn_dbufs); 99 } 100 101 void 102 dnode_init(void) 103 { 104 dnode_cache = kmem_cache_create("dnode_t", 105 sizeof (dnode_t), 106 0, dnode_cons, dnode_dest, NULL, NULL, NULL, 0); 107 } 108 109 void 110 dnode_fini(void) 111 { 112 kmem_cache_destroy(dnode_cache); 113 } 114 115 116 #ifdef ZFS_DEBUG 117 void 118 dnode_verify(dnode_t *dn) 119 { 120 int drop_struct_lock = FALSE; 121 122 ASSERT(dn->dn_phys); 123 ASSERT(dn->dn_objset); 124 125 ASSERT(dn->dn_phys->dn_type < DMU_OT_NUMTYPES); 126 127 if (!(zfs_flags & ZFS_DEBUG_DNODE_VERIFY)) 128 return; 129 130 if (!RW_WRITE_HELD(&dn->dn_struct_rwlock)) { 131 rw_enter(&dn->dn_struct_rwlock, RW_READER); 132 drop_struct_lock = TRUE; 133 } 134 if (dn->dn_phys->dn_type != DMU_OT_NONE || dn->dn_allocated_txg != 0) { 135 int i; 136 ASSERT3U(dn->dn_indblkshift, >=, 0); 137 ASSERT3U(dn->dn_indblkshift, <=, SPA_MAXBLOCKSHIFT); 138 if (dn->dn_datablkshift) { 139 ASSERT3U(dn->dn_datablkshift, >=, SPA_MINBLOCKSHIFT); 140 ASSERT3U(dn->dn_datablkshift, <=, SPA_MAXBLOCKSHIFT); 141 ASSERT3U(1<<dn->dn_datablkshift, ==, dn->dn_datablksz); 142 } 143 ASSERT3U(dn->dn_nlevels, <=, 30); 144 ASSERT3U(dn->dn_type, <=, DMU_OT_NUMTYPES); 145 ASSERT3U(dn->dn_nblkptr, >=, 1); 146 ASSERT3U(dn->dn_nblkptr, <=, DN_MAX_NBLKPTR); 147 ASSERT3U(dn->dn_bonuslen, <=, DN_MAX_BONUSLEN); 148 ASSERT3U(dn->dn_datablksz, ==, 149 dn->dn_datablkszsec << SPA_MINBLOCKSHIFT); 150 ASSERT3U(ISP2(dn->dn_datablksz), ==, dn->dn_datablkshift != 0); 151 ASSERT3U((dn->dn_nblkptr - 1) * sizeof (blkptr_t) + 152 dn->dn_bonuslen, <=, DN_MAX_BONUSLEN); 153 for (i = 0; i < TXG_SIZE; i++) { 154 ASSERT3U(dn->dn_next_nlevels[i], <=, dn->dn_nlevels); 155 } 156 } 157 if (dn->dn_phys->dn_type != DMU_OT_NONE) 158 ASSERT3U(dn->dn_phys->dn_nlevels, <=, dn->dn_nlevels); 159 ASSERT(IS_DNODE_DNODE(dn->dn_object) || dn->dn_dbuf); 160 if (dn->dn_dbuf != NULL) { 161 ASSERT3P(dn->dn_phys, ==, 162 (dnode_phys_t *)dn->dn_dbuf->db.db_data + 163 (dn->dn_object % (dn->dn_dbuf->db.db_size >> DNODE_SHIFT))); 164 } 165 if (drop_struct_lock) 166 rw_exit(&dn->dn_struct_rwlock); 167 } 168 #endif 169 170 void 171 dnode_byteswap(dnode_phys_t *dnp) 172 { 173 uint64_t *buf64 = (void*)&dnp->dn_blkptr; 174 int i; 175 176 if (dnp->dn_type == DMU_OT_NONE) { 177 bzero(dnp, sizeof (dnode_phys_t)); 178 return; 179 } 180 181 dnp->dn_type = BSWAP_8(dnp->dn_type); 182 dnp->dn_indblkshift = BSWAP_8(dnp->dn_indblkshift); 183 dnp->dn_nlevels = BSWAP_8(dnp->dn_nlevels); 184 dnp->dn_nblkptr = BSWAP_8(dnp->dn_nblkptr); 185 dnp->dn_bonustype = BSWAP_8(dnp->dn_bonustype); 186 dnp->dn_checksum = BSWAP_8(dnp->dn_checksum); 187 dnp->dn_compress = BSWAP_8(dnp->dn_compress); 188 dnp->dn_datablkszsec = BSWAP_16(dnp->dn_datablkszsec); 189 dnp->dn_bonuslen = BSWAP_16(dnp->dn_bonuslen); 190 dnp->dn_maxblkid = BSWAP_64(dnp->dn_maxblkid); 191 dnp->dn_secphys = BSWAP_64(dnp->dn_secphys); 192 193 /* 194 * dn_nblkptr is only one byte, so it's OK to read it in either 195 * byte order. We can't read dn_bouslen. 196 */ 197 ASSERT(dnp->dn_indblkshift <= SPA_MAXBLOCKSHIFT); 198 ASSERT(dnp->dn_nblkptr <= DN_MAX_NBLKPTR); 199 for (i = 0; i < dnp->dn_nblkptr * sizeof (blkptr_t)/8; i++) 200 buf64[i] = BSWAP_64(buf64[i]); 201 202 /* 203 * OK to check dn_bonuslen for zero, because it won't matter if 204 * we have the wrong byte order. This is necessary because the 205 * dnode dnode is smaller than a regular dnode. 206 */ 207 if (dnp->dn_bonuslen != 0) { 208 /* 209 * Note that the bonus length calculated here may be 210 * longer than the actual bonus buffer. This is because 211 * we always put the bonus buffer after the last block 212 * pointer (instead of packing it against the end of the 213 * dnode buffer). 214 */ 215 int off = (dnp->dn_nblkptr-1) * sizeof (blkptr_t); 216 size_t len = DN_MAX_BONUSLEN - off; 217 dmu_ot[dnp->dn_bonustype].ot_byteswap(dnp->dn_bonus + off, len); 218 } 219 } 220 221 void 222 dnode_buf_byteswap(void *vbuf, size_t size) 223 { 224 dnode_phys_t *buf = vbuf; 225 int i; 226 227 ASSERT3U(sizeof (dnode_phys_t), ==, (1<<DNODE_SHIFT)); 228 ASSERT((size & (sizeof (dnode_phys_t)-1)) == 0); 229 230 size >>= DNODE_SHIFT; 231 for (i = 0; i < size; i++) { 232 dnode_byteswap(buf); 233 buf++; 234 } 235 } 236 237 static int 238 free_range_compar(const void *node1, const void *node2) 239 { 240 const free_range_t *rp1 = node1; 241 const free_range_t *rp2 = node2; 242 243 if (rp1->fr_blkid < rp2->fr_blkid) 244 return (-1); 245 else if (rp1->fr_blkid > rp2->fr_blkid) 246 return (1); 247 else return (0); 248 } 249 250 static void 251 dnode_setdblksz(dnode_t *dn, int size) 252 { 253 ASSERT3U(P2PHASE(size, SPA_MINBLOCKSIZE), ==, 0); 254 ASSERT3U(size, <=, SPA_MAXBLOCKSIZE); 255 ASSERT3U(size, >=, SPA_MINBLOCKSIZE); 256 ASSERT3U(size >> SPA_MINBLOCKSHIFT, <, 257 1<<(sizeof (dn->dn_phys->dn_datablkszsec) * 8)); 258 dn->dn_datablksz = size; 259 dn->dn_datablkszsec = size >> SPA_MINBLOCKSHIFT; 260 dn->dn_datablkshift = ISP2(size) ? highbit(size - 1) : 0; 261 } 262 263 static dnode_t * 264 dnode_create(objset_impl_t *os, dnode_phys_t *dnp, dmu_buf_impl_t *db, 265 uint64_t object) 266 { 267 dnode_t *dn = kmem_cache_alloc(dnode_cache, KM_SLEEP); 268 (void) dnode_cons(dn, NULL, 0); /* XXX */ 269 270 dn->dn_objset = os; 271 dn->dn_object = object; 272 dn->dn_dbuf = db; 273 dn->dn_phys = dnp; 274 275 if (dnp->dn_datablkszsec) 276 dnode_setdblksz(dn, dnp->dn_datablkszsec << SPA_MINBLOCKSHIFT); 277 dn->dn_indblkshift = dnp->dn_indblkshift; 278 dn->dn_nlevels = dnp->dn_nlevels; 279 dn->dn_type = dnp->dn_type; 280 dn->dn_nblkptr = dnp->dn_nblkptr; 281 dn->dn_checksum = dnp->dn_checksum; 282 dn->dn_compress = dnp->dn_compress; 283 dn->dn_bonustype = dnp->dn_bonustype; 284 dn->dn_bonuslen = dnp->dn_bonuslen; 285 dn->dn_maxblkid = dnp->dn_maxblkid; 286 287 dmu_zfetch_init(&dn->dn_zfetch, dn); 288 289 ASSERT(dn->dn_phys->dn_type < DMU_OT_NUMTYPES); 290 mutex_enter(&os->os_lock); 291 list_insert_head(&os->os_dnodes, dn); 292 mutex_exit(&os->os_lock); 293 294 return (dn); 295 } 296 297 static void 298 dnode_destroy(dnode_t *dn) 299 { 300 objset_impl_t *os = dn->dn_objset; 301 302 mutex_enter(&os->os_lock); 303 list_remove(&os->os_dnodes, dn); 304 mutex_exit(&os->os_lock); 305 306 if (dn->dn_dirtyctx_firstset) { 307 kmem_free(dn->dn_dirtyctx_firstset, 1); 308 dn->dn_dirtyctx_firstset = NULL; 309 } 310 dmu_zfetch_rele(&dn->dn_zfetch); 311 kmem_cache_free(dnode_cache, dn); 312 } 313 314 void 315 dnode_allocate(dnode_t *dn, dmu_object_type_t ot, int blocksize, int ibs, 316 dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx) 317 { 318 int i; 319 320 if (blocksize == 0) 321 blocksize = 1 << zfs_default_bs; 322 323 blocksize = MIN(MAX(blocksize, SPA_MINBLOCKSIZE), SPA_MAXBLOCKSIZE); 324 325 if (ibs == 0) 326 ibs = zfs_default_ibs; 327 328 ibs = MIN(MAX(ibs, DN_MIN_INDBLKSHIFT), DN_MAX_INDBLKSHIFT); 329 330 dprintf("os=%p obj=%llu txg=%llu blocksize=%d ibs=%d\n", dn->dn_objset, 331 dn->dn_object, tx->tx_txg, blocksize, ibs); 332 333 ASSERT(dn->dn_type == DMU_OT_NONE); 334 ASSERT(bcmp(dn->dn_phys, &dnode_phys_zero, sizeof (dnode_phys_t)) == 0); 335 ASSERT(dn->dn_phys->dn_type == DMU_OT_NONE); 336 ASSERT(ot != DMU_OT_NONE); 337 ASSERT3U(ot, <, DMU_OT_NUMTYPES); 338 ASSERT((bonustype == DMU_OT_NONE && bonuslen == 0) || 339 (bonustype != DMU_OT_NONE && bonuslen != 0)); 340 ASSERT3U(bonustype, <, DMU_OT_NUMTYPES); 341 ASSERT3U(bonuslen, <=, DN_MAX_BONUSLEN); 342 ASSERT(dn->dn_type == DMU_OT_NONE); 343 ASSERT3U(dn->dn_maxblkid, ==, 0); 344 ASSERT3U(dn->dn_allocated_txg, ==, 0); 345 ASSERT3U(dn->dn_assigned_txg, ==, 0); 346 ASSERT(refcount_is_zero(&dn->dn_tx_holds)); 347 ASSERT3U(refcount_count(&dn->dn_holds), <=, 1); 348 ASSERT3P(list_head(&dn->dn_dbufs), ==, NULL); 349 350 for (i = 0; i < TXG_SIZE; i++) { 351 ASSERT3U(dn->dn_next_nlevels[i], ==, 0); 352 ASSERT3U(dn->dn_next_indblkshift[i], ==, 0); 353 ASSERT3U(dn->dn_dirtyblksz[i], ==, 0); 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 dnode_setdirty(dn, tx); 377 } 378 379 void 380 dnode_reallocate(dnode_t *dn, dmu_object_type_t ot, int blocksize, 381 dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx) 382 { 383 dmu_buf_impl_t *db = NULL; 384 385 ASSERT3U(blocksize, >=, SPA_MINBLOCKSIZE); 386 ASSERT3U(blocksize, <=, SPA_MAXBLOCKSIZE); 387 ASSERT3U(blocksize % SPA_MINBLOCKSIZE, ==, 0); 388 ASSERT3P(list_head(&dn->dn_dbufs), ==, NULL); 389 ASSERT(!(dn->dn_object & DMU_PRIVATE_OBJECT) || dmu_tx_private_ok(tx)); 390 ASSERT(tx->tx_txg != 0); 391 ASSERT((bonustype == DMU_OT_NONE && bonuslen == 0) || 392 (bonustype != DMU_OT_NONE && bonuslen != 0)); 393 ASSERT3U(bonustype, <, DMU_OT_NUMTYPES); 394 ASSERT3U(bonuslen, <=, DN_MAX_BONUSLEN); 395 ASSERT(dn->dn_dirtyblksz[0] == 0); 396 ASSERT(dn->dn_dirtyblksz[1] == 0); 397 ASSERT(dn->dn_dirtyblksz[2] == 0); 398 ASSERT(dn->dn_dirtyblksz[3] == 0); 399 400 /* 401 * XXX I should really have a generation number to tell if we 402 * need to do this... 403 */ 404 if (blocksize != dn->dn_datablksz || 405 dn->dn_bonustype != bonustype || dn->dn_bonuslen != bonuslen) { 406 /* free all old data */ 407 dnode_free_range(dn, 0, -1ULL, tx); 408 } 409 410 /* change blocksize */ 411 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 412 dnode_setdblksz(dn, blocksize); 413 dnode_setdirty(dn, tx); 414 /* don't need dd_dirty_mtx, dnode is already dirty */ 415 ASSERT(dn->dn_dirtyblksz[tx->tx_txg&TXG_MASK] != 0); 416 dn->dn_dirtyblksz[tx->tx_txg&TXG_MASK] = blocksize; 417 rw_exit(&dn->dn_struct_rwlock); 418 419 /* change type */ 420 dn->dn_type = ot; 421 422 if (dn->dn_bonuslen != bonuslen) { 423 /* change bonus size */ 424 if (bonuslen == 0) 425 bonuslen = 1; /* XXX */ 426 db = dbuf_hold_bonus(dn, FTAG); 427 dbuf_read(db); 428 mutex_enter(&db->db_mtx); 429 ASSERT3U(db->db.db_size, ==, dn->dn_bonuslen); 430 ASSERT(db->db.db_data != NULL); 431 db->db.db_size = bonuslen; 432 mutex_exit(&db->db_mtx); 433 dbuf_dirty(db, tx); 434 } 435 436 /* change bonus size and type */ 437 mutex_enter(&dn->dn_mtx); 438 dn->dn_bonustype = bonustype; 439 dn->dn_bonuslen = bonuslen; 440 dn->dn_nblkptr = 1 + ((DN_MAX_BONUSLEN - bonuslen) >> SPA_BLKPTRSHIFT); 441 dn->dn_checksum = ZIO_CHECKSUM_INHERIT; 442 dn->dn_compress = ZIO_COMPRESS_INHERIT; 443 ASSERT3U(dn->dn_nblkptr, <=, DN_MAX_NBLKPTR); 444 445 dn->dn_allocated_txg = tx->tx_txg; 446 mutex_exit(&dn->dn_mtx); 447 448 if (db) 449 dbuf_remove_ref(db, FTAG); 450 } 451 452 void 453 dnode_special_close(dnode_t *dn) 454 { 455 dnode_destroy(dn); 456 } 457 458 dnode_t * 459 dnode_special_open(objset_impl_t *os, dnode_phys_t *dnp, uint64_t object) 460 { 461 dnode_t *dn = dnode_create(os, dnp, NULL, object); 462 DNODE_VERIFY(dn); 463 return (dn); 464 } 465 466 static void 467 dnode_buf_pageout(dmu_buf_t *db, void *arg) 468 { 469 dnode_t **children_dnodes = arg; 470 int i; 471 int epb = db->db_size >> DNODE_SHIFT; 472 473 for (i = 0; i < epb; i++) { 474 dnode_t *dn = children_dnodes[i]; 475 int n; 476 477 if (dn == NULL) 478 continue; 479 #ifdef ZFS_DEBUG 480 /* 481 * If there are holds on this dnode, then there should 482 * be holds on the dnode's containing dbuf as well; thus 483 * it wouldn't be eligable for eviction and this function 484 * would not have been called. 485 */ 486 ASSERT(refcount_is_zero(&dn->dn_holds)); 487 ASSERT(list_head(&dn->dn_dbufs) == NULL); 488 ASSERT(refcount_is_zero(&dn->dn_tx_holds)); 489 490 for (n = 0; n < TXG_SIZE; n++) 491 ASSERT(dn->dn_dirtyblksz[n] == 0); 492 #endif 493 children_dnodes[i] = NULL; 494 dnode_destroy(dn); 495 } 496 kmem_free(children_dnodes, epb * sizeof (dnode_t *)); 497 } 498 499 /* 500 * Returns held dnode if the object number is valid, NULL if not. 501 * Note that this will succeed even for free dnodes. 502 */ 503 dnode_t * 504 dnode_hold_impl(objset_impl_t *os, uint64_t object, int flag, void *ref) 505 { 506 int epb, idx; 507 int drop_struct_lock = FALSE; 508 uint64_t blk; 509 dnode_t *mdn, *dn; 510 dmu_buf_impl_t *db; 511 dnode_t **children_dnodes; 512 513 if (object == 0 || object >= DN_MAX_OBJECT) 514 return (NULL); 515 516 mdn = os->os_meta_dnode; 517 518 DNODE_VERIFY(mdn); 519 520 if (!RW_WRITE_HELD(&mdn->dn_struct_rwlock)) { 521 rw_enter(&mdn->dn_struct_rwlock, RW_READER); 522 drop_struct_lock = TRUE; 523 } 524 525 blk = dbuf_whichblock(mdn, object * sizeof (dnode_phys_t)); 526 527 db = dbuf_hold(mdn, blk); 528 if (drop_struct_lock) 529 rw_exit(&mdn->dn_struct_rwlock); 530 dbuf_read(db); 531 532 ASSERT3U(db->db.db_size, >=, 1<<DNODE_SHIFT); 533 epb = db->db.db_size >> DNODE_SHIFT; 534 535 idx = object & (epb-1); 536 537 children_dnodes = dmu_buf_get_user(&db->db); 538 if (children_dnodes == NULL) { 539 dnode_t **winner; 540 children_dnodes = kmem_zalloc(epb * sizeof (dnode_t *), 541 KM_SLEEP); 542 if (winner = dmu_buf_set_user(&db->db, children_dnodes, NULL, 543 dnode_buf_pageout)) { 544 kmem_free(children_dnodes, epb * sizeof (dnode_t *)); 545 children_dnodes = winner; 546 } 547 } 548 549 if ((dn = children_dnodes[idx]) == NULL) { 550 dnode_t *winner; 551 dn = dnode_create(os, (dnode_phys_t *)db->db.db_data+idx, 552 db, object); 553 winner = atomic_cas_ptr(&children_dnodes[idx], NULL, dn); 554 if (winner != NULL) { 555 dnode_destroy(dn); 556 dn = winner; 557 } 558 } 559 560 mutex_enter(&dn->dn_mtx); 561 if (dn->dn_free_txg || 562 ((flag & DNODE_MUST_BE_ALLOCATED) && dn->dn_type == DMU_OT_NONE) || 563 ((flag & DNODE_MUST_BE_FREE) && dn->dn_type != DMU_OT_NONE)) { 564 mutex_exit(&dn->dn_mtx); 565 dbuf_rele(db); 566 return (NULL); 567 } 568 mutex_exit(&dn->dn_mtx); 569 570 if (refcount_add(&dn->dn_holds, ref) == 1) 571 dbuf_add_ref(db, dn); 572 573 DNODE_VERIFY(dn); 574 ASSERT3P(dn->dn_dbuf, ==, db); 575 ASSERT3U(dn->dn_object, ==, object); 576 dbuf_rele(db); 577 578 return (dn); 579 } 580 581 /* 582 * Return held dnode if the object is allocated, NULL if not. 583 */ 584 dnode_t * 585 dnode_hold(objset_impl_t *os, uint64_t object, void *ref) 586 { 587 return (dnode_hold_impl(os, object, DNODE_MUST_BE_ALLOCATED, ref)); 588 } 589 590 void 591 dnode_add_ref(dnode_t *dn, void *ref) 592 { 593 ASSERT(refcount_count(&dn->dn_holds) > 0); 594 (void) refcount_add(&dn->dn_holds, ref); 595 } 596 597 void 598 dnode_rele(dnode_t *dn, void *ref) 599 { 600 uint64_t refs; 601 602 refs = refcount_remove(&dn->dn_holds, ref); 603 /* NOTE: the DNODE_DNODE does not have a dn_dbuf */ 604 if (refs == 0 && dn->dn_dbuf) 605 dbuf_remove_ref(dn->dn_dbuf, dn); 606 } 607 608 void 609 dnode_setdirty(dnode_t *dn, dmu_tx_t *tx) 610 { 611 objset_impl_t *os = dn->dn_objset; 612 uint64_t txg = tx->tx_txg; 613 614 if (IS_DNODE_DNODE(dn->dn_object)) 615 return; 616 617 DNODE_VERIFY(dn); 618 619 #ifdef ZFS_DEBUG 620 mutex_enter(&dn->dn_mtx); 621 ASSERT(dn->dn_phys->dn_type || dn->dn_allocated_txg); 622 /* ASSERT(dn->dn_free_txg == 0 || dn->dn_free_txg >= txg); */ 623 mutex_exit(&dn->dn_mtx); 624 #endif 625 626 mutex_enter(&os->os_lock); 627 628 /* 629 * If we are already marked dirty, we're done. 630 */ 631 if (dn->dn_dirtyblksz[txg&TXG_MASK] > 0) { 632 mutex_exit(&os->os_lock); 633 return; 634 } 635 636 ASSERT(!refcount_is_zero(&dn->dn_holds) || list_head(&dn->dn_dbufs)); 637 ASSERT(dn->dn_datablksz != 0); 638 dn->dn_dirtyblksz[txg&TXG_MASK] = dn->dn_datablksz; 639 640 dprintf_ds(os->os_dsl_dataset, "obj=%llu txg=%llu\n", 641 dn->dn_object, txg); 642 643 if (dn->dn_free_txg > 0 && dn->dn_free_txg <= txg) { 644 list_insert_tail(&os->os_free_dnodes[txg&TXG_MASK], dn); 645 } else { 646 list_insert_tail(&os->os_dirty_dnodes[txg&TXG_MASK], dn); 647 } 648 649 mutex_exit(&os->os_lock); 650 651 /* 652 * The dnode maintains a hold on its containing dbuf as 653 * long as there are holds on it. Each instantiated child 654 * dbuf maintaines a hold on the dnode. When the last child 655 * drops its hold, the dnode will drop its hold on the 656 * containing dbuf. We add a "dirty hold" here so that the 657 * dnode will hang around after we finish processing its 658 * children. 659 */ 660 (void) refcount_add(&dn->dn_holds, (void *)(uintptr_t)tx->tx_txg); 661 662 dbuf_dirty(dn->dn_dbuf, tx); 663 664 dsl_dataset_dirty(os->os_dsl_dataset, tx); 665 } 666 667 void 668 dnode_free(dnode_t *dn, dmu_tx_t *tx) 669 { 670 dprintf("dn=%p txg=%llu\n", dn, tx->tx_txg); 671 672 /* we should be the only holder... hopefully */ 673 /* ASSERT3U(refcount_count(&dn->dn_holds), ==, 1); */ 674 675 mutex_enter(&dn->dn_mtx); 676 if (dn->dn_type == DMU_OT_NONE || dn->dn_free_txg) { 677 mutex_exit(&dn->dn_mtx); 678 return; 679 } 680 dn->dn_free_txg = tx->tx_txg; 681 mutex_exit(&dn->dn_mtx); 682 683 /* 684 * If the dnode is already dirty, it needs to be moved from 685 * the dirty list to the free list. 686 */ 687 mutex_enter(&dn->dn_objset->os_lock); 688 if (dn->dn_dirtyblksz[tx->tx_txg&TXG_MASK] > 0) { 689 list_remove( 690 &dn->dn_objset->os_dirty_dnodes[tx->tx_txg&TXG_MASK], dn); 691 list_insert_tail( 692 &dn->dn_objset->os_free_dnodes[tx->tx_txg&TXG_MASK], dn); 693 mutex_exit(&dn->dn_objset->os_lock); 694 } else { 695 mutex_exit(&dn->dn_objset->os_lock); 696 dnode_setdirty(dn, tx); 697 } 698 } 699 700 /* 701 * Try to change the block size for the indicated dnode. This can only 702 * succeed if there are no blocks allocated or dirty beyond first block 703 */ 704 int 705 dnode_set_blksz(dnode_t *dn, uint64_t size, int ibs, dmu_tx_t *tx) 706 { 707 dmu_buf_impl_t *db, *db_next; 708 int have_db0 = FALSE; 709 int err = ENOTSUP; 710 711 if (size == 0) 712 size = SPA_MINBLOCKSIZE; 713 if (size > SPA_MAXBLOCKSIZE) 714 size = SPA_MAXBLOCKSIZE; 715 else 716 size = P2ROUNDUP(size, SPA_MINBLOCKSIZE); 717 718 if (ibs == 0) 719 ibs = dn->dn_indblkshift; 720 721 if (size >> SPA_MINBLOCKSHIFT == dn->dn_datablkszsec && 722 ibs == dn->dn_indblkshift) 723 return (0); 724 725 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 726 727 /* Check for any allocated blocks beyond the first */ 728 if (dn->dn_phys->dn_maxblkid != 0) 729 goto end; 730 731 /* 732 * Any buffers allocated for blocks beyond the first 733 * must be evictable/evicted, because they're the wrong size. 734 */ 735 mutex_enter(&dn->dn_dbufs_mtx); 736 /* 737 * Since we have the dn_dbufs_mtx, nothing can be 738 * removed from dn_dbufs. Since we have dn_struct_rwlock/w, 739 * nothing can be added to dn_dbufs. 740 */ 741 for (db = list_head(&dn->dn_dbufs); db; db = db_next) { 742 db_next = list_next(&dn->dn_dbufs, db); 743 744 if (db->db_blkid == 0) { 745 have_db0 = TRUE; 746 } else if (db->db_blkid != DB_BONUS_BLKID) { 747 mutex_exit(&dn->dn_dbufs_mtx); 748 goto end; 749 } 750 } 751 mutex_exit(&dn->dn_dbufs_mtx); 752 753 /* Fast-track if there is no data in the file */ 754 if (BP_IS_HOLE(&dn->dn_phys->dn_blkptr[0]) && !have_db0) { 755 dnode_setdblksz(dn, size); 756 dn->dn_indblkshift = ibs; 757 dnode_setdirty(dn, tx); 758 /* don't need dd_dirty_mtx, dnode is already dirty */ 759 dn->dn_dirtyblksz[tx->tx_txg&TXG_MASK] = size; 760 dn->dn_next_indblkshift[tx->tx_txg&TXG_MASK] = ibs; 761 rw_exit(&dn->dn_struct_rwlock); 762 return (0); 763 } 764 765 /* obtain the old block */ 766 db = dbuf_hold(dn, 0); 767 768 /* Not allowed to decrease the size if there is data present */ 769 if (size < db->db.db_size) { 770 dbuf_rele(db); 771 goto end; 772 } 773 774 dbuf_new_size(db, size, tx); 775 776 dnode_setdblksz(dn, size); 777 dn->dn_indblkshift = ibs; 778 /* don't need dd_dirty_mtx, dnode is already dirty */ 779 dn->dn_dirtyblksz[tx->tx_txg&TXG_MASK] = size; 780 dn->dn_next_indblkshift[tx->tx_txg&TXG_MASK] = ibs; 781 dbuf_rele(db); 782 783 err = 0; 784 end: 785 rw_exit(&dn->dn_struct_rwlock); 786 return (err); 787 } 788 789 uint64_t 790 dnode_max_nonzero_offset(dnode_t *dn) 791 { 792 if (dn->dn_phys->dn_maxblkid == 0 && 793 BP_IS_HOLE(&dn->dn_phys->dn_blkptr[0])) 794 return (0); 795 else 796 return ((dn->dn_phys->dn_maxblkid+1) * dn->dn_datablksz); 797 } 798 799 void 800 dnode_new_blkid(dnode_t *dn, uint64_t blkid, dmu_tx_t *tx) 801 { 802 uint64_t txgoff = tx->tx_txg & TXG_MASK; 803 int drop_struct_lock = FALSE; 804 int epbs, old_nlevels, new_nlevels; 805 uint64_t sz; 806 807 if (blkid == DB_BONUS_BLKID) 808 return; 809 810 if (!RW_WRITE_HELD(&dn->dn_struct_rwlock)) { 811 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 812 drop_struct_lock = TRUE; 813 } 814 815 if (blkid > dn->dn_maxblkid) 816 dn->dn_maxblkid = blkid; 817 818 /* 819 * Compute the number of levels necessary to support the 820 * new blkid. 821 */ 822 new_nlevels = 1; 823 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT; 824 825 for (sz = dn->dn_nblkptr; sz <= blkid && sz >= dn->dn_nblkptr; 826 sz <<= epbs) 827 new_nlevels++; 828 old_nlevels = dn->dn_nlevels; 829 830 if (new_nlevels > dn->dn_next_nlevels[txgoff]) 831 dn->dn_next_nlevels[txgoff] = new_nlevels; 832 833 if (new_nlevels > old_nlevels) { 834 dprintf("dn %p increasing nlevels from %u to %u\n", 835 dn, dn->dn_nlevels, new_nlevels); 836 dn->dn_nlevels = new_nlevels; 837 } 838 839 /* 840 * Dirty the left indirects. 841 * Note: the caller should have just dnode_use_space()'d one 842 * data block's worth, so we could subtract that out of 843 * dn_inflight_data to determine if there is any dirty data 844 * besides this block. 845 * We don't strictly need to dirty them unless there's 846 * *something* in the object (eg. on disk or dirty)... 847 */ 848 if (new_nlevels > old_nlevels) { 849 dmu_buf_impl_t *db = dbuf_hold_level(dn, old_nlevels, 0, FTAG); 850 dprintf("dn %p dirtying left indirects\n", dn); 851 dbuf_dirty(db, tx); 852 dbuf_remove_ref(db, FTAG); 853 } 854 #ifdef ZFS_DEBUG 855 else if (old_nlevels > 1 && new_nlevels > old_nlevels) { 856 dmu_buf_impl_t *db; 857 int i; 858 859 for (i = 0; i < dn->dn_nblkptr; i++) { 860 db = dbuf_hold_level(dn, old_nlevels-1, i, FTAG); 861 ASSERT(! 862 list_link_active(&db->db_dirty_node[txgoff])); 863 dbuf_remove_ref(db, FTAG); 864 } 865 } 866 #endif 867 868 dprintf("dn %p done\n", dn); 869 870 out: 871 if (drop_struct_lock) 872 rw_exit(&dn->dn_struct_rwlock); 873 } 874 875 void 876 dnode_clear_range(dnode_t *dn, uint64_t blkid, uint64_t nblks, dmu_tx_t *tx) 877 { 878 avl_tree_t *tree = &dn->dn_ranges[tx->tx_txg&TXG_MASK]; 879 avl_index_t where; 880 free_range_t *rp; 881 free_range_t rp_tofind; 882 uint64_t endblk = blkid + nblks; 883 884 ASSERT(MUTEX_HELD(&dn->dn_mtx)); 885 ASSERT(nblks <= UINT64_MAX - blkid); /* no overflow */ 886 887 dprintf_dnode(dn, "blkid=%llu nblks=%llu txg=%llu\n", 888 blkid, nblks, tx->tx_txg); 889 rp_tofind.fr_blkid = blkid; 890 rp = avl_find(tree, &rp_tofind, &where); 891 if (rp == NULL) 892 rp = avl_nearest(tree, where, AVL_BEFORE); 893 if (rp == NULL) 894 rp = avl_nearest(tree, where, AVL_AFTER); 895 896 while (rp && (rp->fr_blkid <= blkid + nblks)) { 897 uint64_t fr_endblk = rp->fr_blkid + rp->fr_nblks; 898 free_range_t *nrp = AVL_NEXT(tree, rp); 899 900 if (blkid <= rp->fr_blkid && endblk >= fr_endblk) { 901 /* clear this entire range */ 902 avl_remove(tree, rp); 903 kmem_free(rp, sizeof (free_range_t)); 904 } else if (blkid <= rp->fr_blkid && 905 endblk > rp->fr_blkid && endblk < fr_endblk) { 906 /* clear the beginning of this range */ 907 rp->fr_blkid = endblk; 908 rp->fr_nblks = fr_endblk - endblk; 909 } else if (blkid > rp->fr_blkid && blkid < fr_endblk && 910 endblk >= fr_endblk) { 911 /* clear the end of this range */ 912 rp->fr_nblks = blkid - rp->fr_blkid; 913 } else if (blkid > rp->fr_blkid && endblk < fr_endblk) { 914 /* clear a chunk out of this range */ 915 free_range_t *new_rp = 916 kmem_alloc(sizeof (free_range_t), KM_SLEEP); 917 918 new_rp->fr_blkid = endblk; 919 new_rp->fr_nblks = fr_endblk - endblk; 920 avl_insert_here(tree, new_rp, rp, AVL_AFTER); 921 rp->fr_nblks = blkid - rp->fr_blkid; 922 } 923 /* there may be no overlap */ 924 rp = nrp; 925 } 926 } 927 928 void 929 dnode_free_range(dnode_t *dn, uint64_t off, uint64_t len, dmu_tx_t *tx) 930 { 931 dmu_buf_impl_t *db; 932 uint64_t start, objsize, blkid, nblks; 933 int blkshift, blksz, tail, head, epbs; 934 int trunc = FALSE; 935 936 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 937 blksz = dn->dn_datablksz; 938 blkshift = dn->dn_datablkshift; 939 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT; 940 941 /* If the range is past the end of the file, this is a no-op */ 942 objsize = blksz * (dn->dn_maxblkid+1); 943 if (off >= objsize) 944 goto out; 945 if (len == -1ULL) { 946 len = UINT64_MAX - off; 947 trunc = TRUE; 948 } 949 950 /* 951 * First, block align the region to free: 952 */ 953 if (dn->dn_maxblkid == 0) { 954 if (off == 0) { 955 head = 0; 956 } else { 957 head = blksz - off; 958 ASSERT3U(head, >, 0); 959 } 960 start = off; 961 } else { 962 ASSERT(ISP2(blksz)); 963 head = P2NPHASE(off, blksz); 964 start = P2PHASE(off, blksz); 965 } 966 /* zero out any partial block data at the start of the range */ 967 if (head) { 968 ASSERT3U(start + head, ==, blksz); 969 if (len < head) 970 head = len; 971 if (dbuf_hold_impl(dn, 0, dbuf_whichblock(dn, off), TRUE, 972 FTAG, &db) == 0) { 973 caddr_t data; 974 975 /* don't dirty if it isn't on disk and isn't dirty */ 976 if (db->db_dirtied || 977 (db->db_blkptr && !BP_IS_HOLE(db->db_blkptr))) { 978 rw_exit(&dn->dn_struct_rwlock); 979 dbuf_will_dirty(db, tx); 980 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 981 data = db->db.db_data; 982 bzero(data + start, head); 983 } 984 dbuf_remove_ref(db, FTAG); 985 } 986 off += head; 987 len -= head; 988 } 989 /* If the range was less than one block, we are done */ 990 if (len == 0) 991 goto out; 992 993 /* If the remaining range is past the end of the file, we are 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 it isn't on disk and isn't dirty */ 1010 if (db->db_dirtied || 1011 (db->db_blkptr && !BP_IS_HOLE(db->db_blkptr))) { 1012 rw_exit(&dn->dn_struct_rwlock); 1013 dbuf_will_dirty(db, tx); 1014 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 1015 bzero(db->db.db_data, tail); 1016 } 1017 dbuf_remove_ref(db, FTAG); 1018 } 1019 len -= tail; 1020 } 1021 /* If the range did not include a full block, we are done */ 1022 if (len == 0) 1023 goto out; 1024 1025 /* dirty the left indirects */ 1026 if (dn->dn_nlevels > 1 && off != 0) { 1027 db = dbuf_hold_level(dn, 1, 1028 (off - head) >> (blkshift + epbs), FTAG); 1029 dbuf_will_dirty(db, tx); 1030 dbuf_remove_ref(db, FTAG); 1031 } 1032 1033 /* dirty the right indirects */ 1034 if (dn->dn_nlevels > 1 && !trunc) { 1035 db = dbuf_hold_level(dn, 1, 1036 (off + len + tail - 1) >> (blkshift + epbs), FTAG); 1037 dbuf_will_dirty(db, tx); 1038 dbuf_remove_ref(db, FTAG); 1039 } 1040 1041 /* 1042 * Finally, add this range to the dnode range list, we 1043 * will finish up this free operation in the syncing phase. 1044 */ 1045 ASSERT(IS_P2ALIGNED(off, 1<<blkshift)); 1046 ASSERT(off + len == UINT64_MAX || IS_P2ALIGNED(len, 1<<blkshift)); 1047 blkid = off >> blkshift; 1048 nblks = len >> blkshift; 1049 1050 if (trunc) 1051 dn->dn_maxblkid = (blkid ? blkid - 1 : 0); 1052 1053 mutex_enter(&dn->dn_mtx); 1054 dnode_clear_range(dn, blkid, nblks, tx); 1055 { 1056 free_range_t *rp, *found; 1057 avl_index_t where; 1058 avl_tree_t *tree = &dn->dn_ranges[tx->tx_txg&TXG_MASK]; 1059 1060 /* Add new range to dn_ranges */ 1061 rp = kmem_alloc(sizeof (free_range_t), KM_SLEEP); 1062 rp->fr_blkid = blkid; 1063 rp->fr_nblks = nblks; 1064 found = avl_find(tree, rp, &where); 1065 ASSERT(found == NULL); 1066 avl_insert(tree, rp, where); 1067 dprintf_dnode(dn, "blkid=%llu nblks=%llu txg=%llu\n", 1068 blkid, nblks, tx->tx_txg); 1069 } 1070 mutex_exit(&dn->dn_mtx); 1071 1072 dbuf_free_range(dn, blkid, nblks, tx); 1073 dnode_setdirty(dn, tx); 1074 out: 1075 rw_exit(&dn->dn_struct_rwlock); 1076 } 1077 1078 /* return TRUE if this blkid was freed in a recent txg, or FALSE if it wasn't */ 1079 uint64_t 1080 dnode_block_freed(dnode_t *dn, uint64_t blkid) 1081 { 1082 free_range_t range_tofind; 1083 void *dp = spa_get_dsl(dn->dn_objset->os_spa); 1084 int i; 1085 1086 if (blkid == DB_BONUS_BLKID) 1087 return (FALSE); 1088 1089 /* 1090 * If we're in the process of opening the pool, dp will not be 1091 * set yet, but there shouldn't be anything dirty. 1092 */ 1093 if (dp == NULL) 1094 return (FALSE); 1095 1096 if (dn->dn_free_txg) 1097 return (TRUE); 1098 1099 /* 1100 * If dn_datablkshift is not set, then there's only a single 1101 * block, in which case there will never be a free range so it 1102 * won't matter. 1103 */ 1104 range_tofind.fr_blkid = blkid; 1105 mutex_enter(&dn->dn_mtx); 1106 for (i = 0; i < TXG_SIZE; i++) { 1107 free_range_t *range_found; 1108 avl_index_t idx; 1109 1110 range_found = avl_find(&dn->dn_ranges[i], &range_tofind, &idx); 1111 if (range_found) { 1112 ASSERT(range_found->fr_nblks > 0); 1113 break; 1114 } 1115 range_found = avl_nearest(&dn->dn_ranges[i], idx, AVL_BEFORE); 1116 if (range_found && 1117 range_found->fr_blkid + range_found->fr_nblks > blkid) 1118 break; 1119 } 1120 mutex_exit(&dn->dn_mtx); 1121 return (i < TXG_SIZE); 1122 } 1123 1124 /* call from syncing context when we actually write/free space for this dnode */ 1125 void 1126 dnode_diduse_space(dnode_t *dn, int64_t space) 1127 { 1128 uint64_t sectors; 1129 1130 dprintf_dnode(dn, "dn=%p dnp=%p secphys=%llu space=%lld\n", 1131 dn, dn->dn_phys, 1132 (u_longlong_t)dn->dn_phys->dn_secphys, 1133 (longlong_t)space); 1134 1135 ASSERT(P2PHASE(space, 1<<DEV_BSHIFT) == 0); 1136 1137 mutex_enter(&dn->dn_mtx); 1138 if (space > 0) { 1139 sectors = space >> DEV_BSHIFT; 1140 ASSERT3U(dn->dn_phys->dn_secphys + sectors, >=, 1141 dn->dn_phys->dn_secphys); 1142 dn->dn_phys->dn_secphys += sectors; 1143 } else { 1144 sectors = -space >> DEV_BSHIFT; 1145 ASSERT3U(dn->dn_phys->dn_secphys, >=, sectors); 1146 dn->dn_phys->dn_secphys -= sectors; 1147 } 1148 mutex_exit(&dn->dn_mtx); 1149 } 1150 1151 /* 1152 * Call when we think we're going to write/free space in open context. 1153 * Be conservative (ie. OK to write less than this or free more than 1154 * this, but don't write more or free less). 1155 */ 1156 void 1157 dnode_willuse_space(dnode_t *dn, int64_t space, dmu_tx_t *tx) 1158 { 1159 objset_impl_t *os = dn->dn_objset; 1160 dsl_dataset_t *ds = os->os_dsl_dataset; 1161 1162 if (space > 0) 1163 space = spa_get_asize(os->os_spa, space); 1164 1165 if (ds) 1166 dsl_dir_willuse_space(ds->ds_dir, space, tx); 1167 1168 dmu_tx_willuse_space(tx, space); 1169 } 1170 1171 static int 1172 dnode_next_offset_level(dnode_t *dn, boolean_t hole, uint64_t *offset, 1173 int lvl, uint64_t blkfill) 1174 { 1175 dmu_buf_impl_t *db = NULL; 1176 void *data = NULL; 1177 uint64_t epbs = dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT; 1178 uint64_t epb = 1ULL << epbs; 1179 uint64_t minfill, maxfill; 1180 int i, error, span; 1181 1182 dprintf("probing object %llu offset %llx level %d of %u\n", 1183 dn->dn_object, *offset, lvl, dn->dn_phys->dn_nlevels); 1184 1185 if (lvl == dn->dn_phys->dn_nlevels) { 1186 error = 0; 1187 epb = dn->dn_phys->dn_nblkptr; 1188 data = dn->dn_phys->dn_blkptr; 1189 } else { 1190 uint64_t blkid = dbuf_whichblock(dn, *offset) >> (epbs * lvl); 1191 error = dbuf_hold_impl(dn, lvl, blkid, TRUE, FTAG, &db); 1192 if (error) { 1193 if (error == ENOENT) 1194 return (hole ? 0 : ESRCH); 1195 return (error); 1196 } 1197 dbuf_read_havestruct(db); 1198 data = db->db.db_data; 1199 } 1200 1201 if (lvl == 0) { 1202 dnode_phys_t *dnp = data; 1203 span = DNODE_SHIFT; 1204 ASSERT(dn->dn_type == DMU_OT_DNODE); 1205 1206 for (i = (*offset >> span) & (blkfill - 1); i < blkfill; i++) { 1207 if (!dnp[i].dn_type == hole) 1208 break; 1209 *offset += 1ULL << span; 1210 } 1211 if (i == blkfill) 1212 error = ESRCH; 1213 } else { 1214 blkptr_t *bp = data; 1215 span = (lvl - 1) * epbs + dn->dn_datablkshift; 1216 minfill = 0; 1217 maxfill = blkfill << ((lvl - 1) * epbs); 1218 1219 if (hole) 1220 maxfill--; 1221 else 1222 minfill++; 1223 1224 for (i = (*offset >> span) & ((1ULL << epbs) - 1); 1225 i < epb; i++) { 1226 if (bp[i].blk_fill >= minfill && 1227 bp[i].blk_fill <= maxfill) 1228 break; 1229 *offset += 1ULL << span; 1230 } 1231 if (i >= epb) 1232 error = ESRCH; 1233 } 1234 1235 if (db) 1236 dbuf_remove_ref(db, FTAG); 1237 1238 return (error); 1239 } 1240 1241 /* 1242 * Find the next hole, data, or sparse region at or after *offset. 1243 * The value 'blkfill' tells us how many items we expect to find 1244 * in an L0 data block; this value is 1 for normal objects, 1245 * DNODES_PER_BLOCK for the meta dnode, and some fraction of 1246 * DNODES_PER_BLOCK when searching for sparse regions thereof. 1247 * Examples: 1248 * 1249 * dnode_next_offset(dn, hole, offset, 1, 1); 1250 * Finds the next hole/data in a file. 1251 * Used in dmu_offset_next(). 1252 * 1253 * dnode_next_offset(mdn, hole, offset, 0, DNODES_PER_BLOCK); 1254 * Finds the next free/allocated dnode an objset's meta-dnode. 1255 * Used in dmu_object_next(). 1256 * 1257 * dnode_next_offset(mdn, TRUE, offset, 2, DNODES_PER_BLOCK >> 2); 1258 * Finds the next L2 meta-dnode bp that's at most 1/4 full. 1259 * Used in dmu_object_alloc(). 1260 */ 1261 int 1262 dnode_next_offset(dnode_t *dn, boolean_t hole, uint64_t *offset, 1263 int minlvl, uint64_t blkfill) 1264 { 1265 int lvl, maxlvl; 1266 int error = 0; 1267 uint64_t initial_offset = *offset; 1268 1269 rw_enter(&dn->dn_struct_rwlock, RW_READER); 1270 1271 if (dn->dn_phys->dn_nlevels == 0) { 1272 rw_exit(&dn->dn_struct_rwlock); 1273 return (ESRCH); 1274 } 1275 1276 if (dn->dn_datablkshift == 0) { 1277 if (*offset < dn->dn_datablksz) { 1278 if (hole) 1279 *offset = dn->dn_datablksz; 1280 } else { 1281 error = ESRCH; 1282 } 1283 rw_exit(&dn->dn_struct_rwlock); 1284 return (error); 1285 } 1286 1287 maxlvl = dn->dn_phys->dn_nlevels; 1288 1289 for (lvl = minlvl; lvl <= maxlvl; lvl++) { 1290 error = dnode_next_offset_level(dn, hole, offset, lvl, blkfill); 1291 if (error == 0) 1292 break; 1293 } 1294 1295 while (--lvl >= minlvl && error == 0) 1296 error = dnode_next_offset_level(dn, hole, offset, lvl, blkfill); 1297 1298 rw_exit(&dn->dn_struct_rwlock); 1299 1300 if (initial_offset > *offset) 1301 return (ESRCH); 1302 1303 return (error); 1304 } 1305