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 2006 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 else if (blocksize > SPA_MAXBLOCKSIZE) 323 blocksize = SPA_MAXBLOCKSIZE; 324 else 325 blocksize = P2ROUNDUP(blocksize, SPA_MINBLOCKSIZE); 326 327 if (ibs == 0) 328 ibs = zfs_default_ibs; 329 330 ibs = MIN(MAX(ibs, DN_MIN_INDBLKSHIFT), DN_MAX_INDBLKSHIFT); 331 332 dprintf("os=%p obj=%llu txg=%llu blocksize=%d ibs=%d\n", dn->dn_objset, 333 dn->dn_object, tx->tx_txg, blocksize, ibs); 334 335 ASSERT(dn->dn_type == DMU_OT_NONE); 336 ASSERT(bcmp(dn->dn_phys, &dnode_phys_zero, sizeof (dnode_phys_t)) == 0); 337 ASSERT(dn->dn_phys->dn_type == DMU_OT_NONE); 338 ASSERT(ot != DMU_OT_NONE); 339 ASSERT3U(ot, <, DMU_OT_NUMTYPES); 340 ASSERT((bonustype == DMU_OT_NONE && bonuslen == 0) || 341 (bonustype != DMU_OT_NONE && bonuslen != 0)); 342 ASSERT3U(bonustype, <, DMU_OT_NUMTYPES); 343 ASSERT3U(bonuslen, <=, DN_MAX_BONUSLEN); 344 ASSERT(dn->dn_type == DMU_OT_NONE); 345 ASSERT3U(dn->dn_maxblkid, ==, 0); 346 ASSERT3U(dn->dn_allocated_txg, ==, 0); 347 ASSERT3U(dn->dn_assigned_txg, ==, 0); 348 ASSERT(refcount_is_zero(&dn->dn_tx_holds)); 349 ASSERT3U(refcount_count(&dn->dn_holds), <=, 1); 350 ASSERT3P(list_head(&dn->dn_dbufs), ==, NULL); 351 352 for (i = 0; i < TXG_SIZE; i++) { 353 ASSERT3U(dn->dn_next_nlevels[i], ==, 0); 354 ASSERT3U(dn->dn_next_indblkshift[i], ==, 0); 355 ASSERT3U(dn->dn_dirtyblksz[i], ==, 0); 356 ASSERT3P(list_head(&dn->dn_dirty_dbufs[i]), ==, NULL); 357 ASSERT3U(avl_numnodes(&dn->dn_ranges[i]), ==, 0); 358 } 359 360 dn->dn_type = ot; 361 dnode_setdblksz(dn, blocksize); 362 dn->dn_indblkshift = ibs; 363 dn->dn_nlevels = 1; 364 dn->dn_nblkptr = 1 + ((DN_MAX_BONUSLEN - bonuslen) >> SPA_BLKPTRSHIFT); 365 dn->dn_bonustype = bonustype; 366 dn->dn_bonuslen = bonuslen; 367 dn->dn_checksum = ZIO_CHECKSUM_INHERIT; 368 dn->dn_compress = ZIO_COMPRESS_INHERIT; 369 dn->dn_dirtyctx = 0; 370 371 dn->dn_free_txg = 0; 372 if (dn->dn_dirtyctx_firstset) { 373 kmem_free(dn->dn_dirtyctx_firstset, 1); 374 dn->dn_dirtyctx_firstset = NULL; 375 } 376 377 dn->dn_allocated_txg = tx->tx_txg; 378 dnode_setdirty(dn, tx); 379 } 380 381 void 382 dnode_reallocate(dnode_t *dn, dmu_object_type_t ot, int blocksize, 383 dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx) 384 { 385 dmu_buf_impl_t *db = NULL; 386 387 ASSERT3U(blocksize, >=, SPA_MINBLOCKSIZE); 388 ASSERT3U(blocksize, <=, SPA_MAXBLOCKSIZE); 389 ASSERT3U(blocksize % SPA_MINBLOCKSIZE, ==, 0); 390 ASSERT3P(list_head(&dn->dn_dbufs), ==, NULL); 391 ASSERT(!(dn->dn_object & DMU_PRIVATE_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 ASSERT(dn->dn_dirtyblksz[0] == 0); 398 ASSERT(dn->dn_dirtyblksz[1] == 0); 399 ASSERT(dn->dn_dirtyblksz[2] == 0); 400 ASSERT(dn->dn_dirtyblksz[3] == 0); 401 402 /* 403 * XXX I should really have a generation number to tell if we 404 * need to do this... 405 */ 406 if (blocksize != dn->dn_datablksz || 407 dn->dn_bonustype != bonustype || dn->dn_bonuslen != bonuslen) { 408 /* free all old data */ 409 dnode_free_range(dn, 0, -1ULL, tx); 410 } 411 412 /* change blocksize */ 413 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 414 dnode_setdblksz(dn, blocksize); 415 dnode_setdirty(dn, tx); 416 /* don't need dd_dirty_mtx, dnode is already dirty */ 417 ASSERT(dn->dn_dirtyblksz[tx->tx_txg&TXG_MASK] != 0); 418 dn->dn_dirtyblksz[tx->tx_txg&TXG_MASK] = blocksize; 419 rw_exit(&dn->dn_struct_rwlock); 420 421 /* change type */ 422 dn->dn_type = ot; 423 424 if (dn->dn_bonuslen != bonuslen) { 425 /* change bonus size */ 426 if (bonuslen == 0) 427 bonuslen = 1; /* XXX */ 428 db = dbuf_hold_bonus(dn, FTAG); 429 dbuf_read(db); 430 mutex_enter(&db->db_mtx); 431 ASSERT3U(db->db.db_size, ==, dn->dn_bonuslen); 432 ASSERT(db->db.db_data != NULL); 433 db->db.db_size = bonuslen; 434 mutex_exit(&db->db_mtx); 435 dbuf_dirty(db, tx); 436 } 437 438 /* change bonus size and type */ 439 mutex_enter(&dn->dn_mtx); 440 dn->dn_bonustype = bonustype; 441 dn->dn_bonuslen = bonuslen; 442 dn->dn_nblkptr = 1 + ((DN_MAX_BONUSLEN - bonuslen) >> SPA_BLKPTRSHIFT); 443 dn->dn_checksum = ZIO_CHECKSUM_INHERIT; 444 dn->dn_compress = ZIO_COMPRESS_INHERIT; 445 ASSERT3U(dn->dn_nblkptr, <=, DN_MAX_NBLKPTR); 446 447 dn->dn_allocated_txg = tx->tx_txg; 448 mutex_exit(&dn->dn_mtx); 449 450 if (db) 451 dbuf_remove_ref(db, FTAG); 452 } 453 454 void 455 dnode_special_close(dnode_t *dn) 456 { 457 dnode_destroy(dn); 458 } 459 460 dnode_t * 461 dnode_special_open(objset_impl_t *os, dnode_phys_t *dnp, uint64_t object) 462 { 463 dnode_t *dn = dnode_create(os, dnp, NULL, object); 464 DNODE_VERIFY(dn); 465 return (dn); 466 } 467 468 static void 469 dnode_buf_pageout(dmu_buf_t *db, void *arg) 470 { 471 dnode_t **children_dnodes = arg; 472 int i; 473 int epb = db->db_size >> DNODE_SHIFT; 474 475 for (i = 0; i < epb; i++) { 476 dnode_t *dn = children_dnodes[i]; 477 int n; 478 479 if (dn == NULL) 480 continue; 481 #ifdef ZFS_DEBUG 482 /* 483 * If there are holds on this dnode, then there should 484 * be holds on the dnode's containing dbuf as well; thus 485 * it wouldn't be eligable for eviction and this function 486 * would not have been called. 487 */ 488 ASSERT(refcount_is_zero(&dn->dn_holds)); 489 ASSERT(list_head(&dn->dn_dbufs) == NULL); 490 ASSERT(refcount_is_zero(&dn->dn_tx_holds)); 491 492 for (n = 0; n < TXG_SIZE; n++) 493 ASSERT(dn->dn_dirtyblksz[n] == 0); 494 #endif 495 children_dnodes[i] = NULL; 496 dnode_destroy(dn); 497 } 498 kmem_free(children_dnodes, epb * sizeof (dnode_t *)); 499 } 500 501 /* 502 * Returns held dnode if the object number is valid, NULL if not. 503 * Note that this will succeed even for free dnodes. 504 */ 505 dnode_t * 506 dnode_hold_impl(objset_impl_t *os, uint64_t object, int flag, void *ref) 507 { 508 int epb, idx; 509 int drop_struct_lock = FALSE; 510 uint64_t blk; 511 dnode_t *mdn, *dn; 512 dmu_buf_impl_t *db; 513 dnode_t **children_dnodes; 514 515 if (object == 0 || object >= DN_MAX_OBJECT) 516 return (NULL); 517 518 mdn = os->os_meta_dnode; 519 520 DNODE_VERIFY(mdn); 521 522 if (!RW_WRITE_HELD(&mdn->dn_struct_rwlock)) { 523 rw_enter(&mdn->dn_struct_rwlock, RW_READER); 524 drop_struct_lock = TRUE; 525 } 526 527 blk = dbuf_whichblock(mdn, object * sizeof (dnode_phys_t)); 528 529 db = dbuf_hold(mdn, blk); 530 if (drop_struct_lock) 531 rw_exit(&mdn->dn_struct_rwlock); 532 dbuf_read(db); 533 534 ASSERT3U(db->db.db_size, >=, 1<<DNODE_SHIFT); 535 epb = db->db.db_size >> DNODE_SHIFT; 536 537 idx = object & (epb-1); 538 539 children_dnodes = dmu_buf_get_user(&db->db); 540 if (children_dnodes == NULL) { 541 dnode_t **winner; 542 children_dnodes = kmem_zalloc(epb * sizeof (dnode_t *), 543 KM_SLEEP); 544 if (winner = dmu_buf_set_user(&db->db, children_dnodes, NULL, 545 dnode_buf_pageout)) { 546 kmem_free(children_dnodes, epb * sizeof (dnode_t *)); 547 children_dnodes = winner; 548 } 549 } 550 551 if ((dn = children_dnodes[idx]) == NULL) { 552 dnode_t *winner; 553 dn = dnode_create(os, (dnode_phys_t *)db->db.db_data+idx, 554 db, object); 555 winner = atomic_cas_ptr(&children_dnodes[idx], NULL, dn); 556 if (winner != NULL) { 557 dnode_destroy(dn); 558 dn = winner; 559 } 560 } 561 562 mutex_enter(&dn->dn_mtx); 563 if (dn->dn_free_txg || 564 ((flag & DNODE_MUST_BE_ALLOCATED) && dn->dn_type == DMU_OT_NONE) || 565 ((flag & DNODE_MUST_BE_FREE) && dn->dn_type != DMU_OT_NONE)) { 566 mutex_exit(&dn->dn_mtx); 567 dbuf_rele(db); 568 return (NULL); 569 } 570 mutex_exit(&dn->dn_mtx); 571 572 if (refcount_add(&dn->dn_holds, ref) == 1) 573 dbuf_add_ref(db, dn); 574 575 DNODE_VERIFY(dn); 576 ASSERT3P(dn->dn_dbuf, ==, db); 577 ASSERT3U(dn->dn_object, ==, object); 578 dbuf_rele(db); 579 580 return (dn); 581 } 582 583 /* 584 * Return held dnode if the object is allocated, NULL if not. 585 */ 586 dnode_t * 587 dnode_hold(objset_impl_t *os, uint64_t object, void *ref) 588 { 589 return (dnode_hold_impl(os, object, DNODE_MUST_BE_ALLOCATED, ref)); 590 } 591 592 void 593 dnode_add_ref(dnode_t *dn, void *ref) 594 { 595 ASSERT(refcount_count(&dn->dn_holds) > 0); 596 (void) refcount_add(&dn->dn_holds, ref); 597 } 598 599 void 600 dnode_rele(dnode_t *dn, void *ref) 601 { 602 uint64_t refs; 603 604 refs = refcount_remove(&dn->dn_holds, ref); 605 /* NOTE: the DNODE_DNODE does not have a dn_dbuf */ 606 if (refs == 0 && dn->dn_dbuf) 607 dbuf_remove_ref(dn->dn_dbuf, dn); 608 } 609 610 void 611 dnode_setdirty(dnode_t *dn, dmu_tx_t *tx) 612 { 613 objset_impl_t *os = dn->dn_objset; 614 uint64_t txg = tx->tx_txg; 615 616 if (IS_DNODE_DNODE(dn->dn_object)) 617 return; 618 619 DNODE_VERIFY(dn); 620 621 #ifdef ZFS_DEBUG 622 mutex_enter(&dn->dn_mtx); 623 ASSERT(dn->dn_phys->dn_type || dn->dn_allocated_txg); 624 /* ASSERT(dn->dn_free_txg == 0 || dn->dn_free_txg >= txg); */ 625 mutex_exit(&dn->dn_mtx); 626 #endif 627 628 mutex_enter(&os->os_lock); 629 630 /* 631 * If we are already marked dirty, we're done. 632 */ 633 if (dn->dn_dirtyblksz[txg&TXG_MASK] > 0) { 634 mutex_exit(&os->os_lock); 635 return; 636 } 637 638 ASSERT(!refcount_is_zero(&dn->dn_holds) || list_head(&dn->dn_dbufs)); 639 ASSERT(dn->dn_datablksz != 0); 640 dn->dn_dirtyblksz[txg&TXG_MASK] = dn->dn_datablksz; 641 642 dprintf_ds(os->os_dsl_dataset, "obj=%llu txg=%llu\n", 643 dn->dn_object, txg); 644 645 if (dn->dn_free_txg > 0 && dn->dn_free_txg <= txg) { 646 list_insert_tail(&os->os_free_dnodes[txg&TXG_MASK], dn); 647 } else { 648 list_insert_tail(&os->os_dirty_dnodes[txg&TXG_MASK], dn); 649 } 650 651 mutex_exit(&os->os_lock); 652 653 /* 654 * The dnode maintains a hold on its containing dbuf as 655 * long as there are holds on it. Each instantiated child 656 * dbuf maintaines a hold on the dnode. When the last child 657 * drops its hold, the dnode will drop its hold on the 658 * containing dbuf. We add a "dirty hold" here so that the 659 * dnode will hang around after we finish processing its 660 * children. 661 */ 662 (void) refcount_add(&dn->dn_holds, (void *)(uintptr_t)tx->tx_txg); 663 664 dbuf_dirty(dn->dn_dbuf, tx); 665 666 dsl_dataset_dirty(os->os_dsl_dataset, tx); 667 } 668 669 void 670 dnode_free(dnode_t *dn, dmu_tx_t *tx) 671 { 672 dprintf("dn=%p txg=%llu\n", dn, tx->tx_txg); 673 674 /* we should be the only holder... hopefully */ 675 /* ASSERT3U(refcount_count(&dn->dn_holds), ==, 1); */ 676 677 mutex_enter(&dn->dn_mtx); 678 if (dn->dn_type == DMU_OT_NONE || dn->dn_free_txg) { 679 mutex_exit(&dn->dn_mtx); 680 return; 681 } 682 dn->dn_free_txg = tx->tx_txg; 683 mutex_exit(&dn->dn_mtx); 684 685 /* 686 * If the dnode is already dirty, it needs to be moved from 687 * the dirty list to the free list. 688 */ 689 mutex_enter(&dn->dn_objset->os_lock); 690 if (dn->dn_dirtyblksz[tx->tx_txg&TXG_MASK] > 0) { 691 list_remove( 692 &dn->dn_objset->os_dirty_dnodes[tx->tx_txg&TXG_MASK], dn); 693 list_insert_tail( 694 &dn->dn_objset->os_free_dnodes[tx->tx_txg&TXG_MASK], dn); 695 mutex_exit(&dn->dn_objset->os_lock); 696 } else { 697 mutex_exit(&dn->dn_objset->os_lock); 698 dnode_setdirty(dn, tx); 699 } 700 } 701 702 /* 703 * Try to change the block size for the indicated dnode. This can only 704 * succeed if there are no blocks allocated or dirty beyond first block 705 */ 706 int 707 dnode_set_blksz(dnode_t *dn, uint64_t size, int ibs, dmu_tx_t *tx) 708 { 709 dmu_buf_impl_t *db, *db_next; 710 int have_db0 = FALSE; 711 int err = ENOTSUP; 712 713 if (size == 0) 714 size = SPA_MINBLOCKSIZE; 715 if (size > SPA_MAXBLOCKSIZE) 716 size = SPA_MAXBLOCKSIZE; 717 else 718 size = P2ROUNDUP(size, SPA_MINBLOCKSIZE); 719 720 if (ibs == 0) 721 ibs = dn->dn_indblkshift; 722 723 if (size >> SPA_MINBLOCKSHIFT == dn->dn_datablkszsec && 724 ibs == dn->dn_indblkshift) 725 return (0); 726 727 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 728 729 /* Check for any allocated blocks beyond the first */ 730 if (dn->dn_phys->dn_maxblkid != 0) 731 goto end; 732 733 /* 734 * Any buffers allocated for blocks beyond the first 735 * must be evictable/evicted, because they're the wrong size. 736 */ 737 mutex_enter(&dn->dn_dbufs_mtx); 738 /* 739 * Since we have the dn_dbufs_mtx, nothing can be 740 * removed from dn_dbufs. Since we have dn_struct_rwlock/w, 741 * nothing can be added to dn_dbufs. 742 */ 743 for (db = list_head(&dn->dn_dbufs); db; db = db_next) { 744 db_next = list_next(&dn->dn_dbufs, db); 745 746 if (db->db_blkid == 0) { 747 have_db0 = TRUE; 748 } else if (db->db_blkid != DB_BONUS_BLKID) { 749 mutex_exit(&dn->dn_dbufs_mtx); 750 goto end; 751 } 752 } 753 mutex_exit(&dn->dn_dbufs_mtx); 754 755 /* Fast-track if there is no data in the file */ 756 if (BP_IS_HOLE(&dn->dn_phys->dn_blkptr[0]) && !have_db0) { 757 dnode_setdblksz(dn, size); 758 dn->dn_indblkshift = ibs; 759 dnode_setdirty(dn, tx); 760 /* don't need dd_dirty_mtx, dnode is already dirty */ 761 dn->dn_dirtyblksz[tx->tx_txg&TXG_MASK] = size; 762 dn->dn_next_indblkshift[tx->tx_txg&TXG_MASK] = ibs; 763 rw_exit(&dn->dn_struct_rwlock); 764 return (0); 765 } 766 767 /* obtain the old block */ 768 db = dbuf_hold(dn, 0); 769 770 /* Not allowed to decrease the size if there is data present */ 771 if (size < db->db.db_size) { 772 dbuf_rele(db); 773 goto end; 774 } 775 776 dbuf_new_size(db, size, tx); 777 778 dnode_setdblksz(dn, size); 779 dn->dn_indblkshift = ibs; 780 /* don't need dd_dirty_mtx, dnode is already dirty */ 781 dn->dn_dirtyblksz[tx->tx_txg&TXG_MASK] = size; 782 dn->dn_next_indblkshift[tx->tx_txg&TXG_MASK] = ibs; 783 dbuf_rele(db); 784 785 err = 0; 786 end: 787 rw_exit(&dn->dn_struct_rwlock); 788 return (err); 789 } 790 791 uint64_t 792 dnode_max_nonzero_offset(dnode_t *dn) 793 { 794 if (dn->dn_phys->dn_maxblkid == 0 && 795 BP_IS_HOLE(&dn->dn_phys->dn_blkptr[0])) 796 return (0); 797 else 798 return ((dn->dn_phys->dn_maxblkid+1) * dn->dn_datablksz); 799 } 800 801 void 802 dnode_new_blkid(dnode_t *dn, uint64_t blkid, dmu_tx_t *tx) 803 { 804 uint64_t txgoff = tx->tx_txg & TXG_MASK; 805 int drop_struct_lock = FALSE; 806 int epbs, old_nlevels, new_nlevels; 807 uint64_t sz; 808 809 if (blkid == DB_BONUS_BLKID) 810 return; 811 812 if (!RW_WRITE_HELD(&dn->dn_struct_rwlock)) { 813 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 814 drop_struct_lock = TRUE; 815 } 816 817 if (blkid > dn->dn_maxblkid) 818 dn->dn_maxblkid = blkid; 819 820 /* 821 * Compute the number of levels necessary to support the 822 * new blkid. 823 */ 824 new_nlevels = 1; 825 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT; 826 827 for (sz = dn->dn_nblkptr; sz <= blkid && sz >= dn->dn_nblkptr; 828 sz <<= epbs) 829 new_nlevels++; 830 old_nlevels = dn->dn_nlevels; 831 832 if (new_nlevels > dn->dn_next_nlevels[txgoff]) 833 dn->dn_next_nlevels[txgoff] = new_nlevels; 834 835 if (new_nlevels > old_nlevels) { 836 dprintf("dn %p increasing nlevels from %u to %u\n", 837 dn, dn->dn_nlevels, new_nlevels); 838 dn->dn_nlevels = new_nlevels; 839 } 840 841 /* 842 * Dirty the left indirects. 843 * Note: the caller should have just dnode_use_space()'d one 844 * data block's worth, so we could subtract that out of 845 * dn_inflight_data to determine if there is any dirty data 846 * besides this block. 847 * We don't strictly need to dirty them unless there's 848 * *something* in the object (eg. on disk or dirty)... 849 */ 850 if (new_nlevels > old_nlevels) { 851 dmu_buf_impl_t *db = dbuf_hold_level(dn, old_nlevels, 0, FTAG); 852 dprintf("dn %p dirtying left indirects\n", dn); 853 dbuf_dirty(db, tx); 854 dbuf_remove_ref(db, FTAG); 855 } 856 #ifdef ZFS_DEBUG 857 else if (old_nlevels > 1 && new_nlevels > old_nlevels) { 858 dmu_buf_impl_t *db; 859 int i; 860 861 for (i = 0; i < dn->dn_nblkptr; i++) { 862 db = dbuf_hold_level(dn, old_nlevels-1, i, FTAG); 863 ASSERT(! 864 list_link_active(&db->db_dirty_node[txgoff])); 865 dbuf_remove_ref(db, FTAG); 866 } 867 } 868 #endif 869 870 dprintf("dn %p done\n", dn); 871 872 out: 873 if (drop_struct_lock) 874 rw_exit(&dn->dn_struct_rwlock); 875 } 876 877 void 878 dnode_clear_range(dnode_t *dn, uint64_t blkid, uint64_t nblks, dmu_tx_t *tx) 879 { 880 avl_tree_t *tree = &dn->dn_ranges[tx->tx_txg&TXG_MASK]; 881 avl_index_t where; 882 free_range_t *rp; 883 free_range_t rp_tofind; 884 uint64_t endblk = blkid + nblks; 885 886 ASSERT(MUTEX_HELD(&dn->dn_mtx)); 887 ASSERT(nblks <= UINT64_MAX - blkid); /* no overflow */ 888 889 dprintf_dnode(dn, "blkid=%llu nblks=%llu txg=%llu\n", 890 blkid, nblks, tx->tx_txg); 891 rp_tofind.fr_blkid = blkid; 892 rp = avl_find(tree, &rp_tofind, &where); 893 if (rp == NULL) 894 rp = avl_nearest(tree, where, AVL_BEFORE); 895 if (rp == NULL) 896 rp = avl_nearest(tree, where, AVL_AFTER); 897 898 while (rp && (rp->fr_blkid <= blkid + nblks)) { 899 uint64_t fr_endblk = rp->fr_blkid + rp->fr_nblks; 900 free_range_t *nrp = AVL_NEXT(tree, rp); 901 902 if (blkid <= rp->fr_blkid && endblk >= fr_endblk) { 903 /* clear this entire range */ 904 avl_remove(tree, rp); 905 kmem_free(rp, sizeof (free_range_t)); 906 } else if (blkid <= rp->fr_blkid && 907 endblk > rp->fr_blkid && endblk < fr_endblk) { 908 /* clear the beginning of this range */ 909 rp->fr_blkid = endblk; 910 rp->fr_nblks = fr_endblk - endblk; 911 } else if (blkid > rp->fr_blkid && blkid < fr_endblk && 912 endblk >= fr_endblk) { 913 /* clear the end of this range */ 914 rp->fr_nblks = blkid - rp->fr_blkid; 915 } else if (blkid > rp->fr_blkid && endblk < fr_endblk) { 916 /* clear a chunk out of this range */ 917 free_range_t *new_rp = 918 kmem_alloc(sizeof (free_range_t), KM_SLEEP); 919 920 new_rp->fr_blkid = endblk; 921 new_rp->fr_nblks = fr_endblk - endblk; 922 avl_insert_here(tree, new_rp, rp, AVL_AFTER); 923 rp->fr_nblks = blkid - rp->fr_blkid; 924 } 925 /* there may be no overlap */ 926 rp = nrp; 927 } 928 } 929 930 void 931 dnode_free_range(dnode_t *dn, uint64_t off, uint64_t len, dmu_tx_t *tx) 932 { 933 dmu_buf_impl_t *db; 934 uint64_t start, objsize, blkid, nblks; 935 int blkshift, blksz, tail, head, epbs; 936 int trunc = FALSE; 937 938 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 939 blksz = dn->dn_datablksz; 940 blkshift = dn->dn_datablkshift; 941 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT; 942 943 /* If the range is past the end of the file, this is a no-op */ 944 objsize = blksz * (dn->dn_maxblkid+1); 945 if (off >= objsize) 946 goto out; 947 if (len == -1ULL) { 948 len = UINT64_MAX - off; 949 trunc = TRUE; 950 } 951 952 /* 953 * First, block align the region to free: 954 */ 955 if (dn->dn_maxblkid == 0) { 956 if (off == 0) { 957 head = 0; 958 } else { 959 head = blksz - off; 960 ASSERT3U(head, >, 0); 961 } 962 start = off; 963 } else { 964 ASSERT(ISP2(blksz)); 965 head = P2NPHASE(off, blksz); 966 start = P2PHASE(off, blksz); 967 } 968 /* zero out any partial block data at the start of the range */ 969 if (head) { 970 ASSERT3U(start + head, ==, blksz); 971 if (len < head) 972 head = len; 973 if (dbuf_hold_impl(dn, 0, dbuf_whichblock(dn, off), TRUE, 974 FTAG, &db) == 0) { 975 caddr_t data; 976 977 /* don't dirty if it isn't on disk and isn't dirty */ 978 if (db->db_dirtied || 979 (db->db_blkptr && !BP_IS_HOLE(db->db_blkptr))) { 980 rw_exit(&dn->dn_struct_rwlock); 981 dbuf_will_dirty(db, tx); 982 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 983 data = db->db.db_data; 984 bzero(data + start, head); 985 } 986 dbuf_remove_ref(db, FTAG); 987 } 988 off += head; 989 len -= head; 990 } 991 /* If the range was less than one block, we are done */ 992 if (len == 0) 993 goto out; 994 995 /* If the remaining range is past the end of the file, we are done */ 996 if (off > dn->dn_maxblkid << blkshift) 997 goto out; 998 999 if (off + len == UINT64_MAX) 1000 tail = 0; 1001 else 1002 tail = P2PHASE(len, blksz); 1003 1004 ASSERT3U(P2PHASE(off, blksz), ==, 0); 1005 /* zero out any partial block data at the end of the range */ 1006 if (tail) { 1007 if (len < tail) 1008 tail = len; 1009 if (dbuf_hold_impl(dn, 0, dbuf_whichblock(dn, off+len), 1010 TRUE, FTAG, &db) == 0) { 1011 /* don't dirty if it isn't on disk and isn't dirty */ 1012 if (db->db_dirtied || 1013 (db->db_blkptr && !BP_IS_HOLE(db->db_blkptr))) { 1014 rw_exit(&dn->dn_struct_rwlock); 1015 dbuf_will_dirty(db, tx); 1016 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 1017 bzero(db->db.db_data, tail); 1018 } 1019 dbuf_remove_ref(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_remove_ref(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_remove_ref(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 || IS_P2ALIGNED(len, 1<<blkshift)); 1049 blkid = off >> blkshift; 1050 nblks = len >> blkshift; 1051 1052 if (trunc) 1053 dn->dn_maxblkid = (blkid ? blkid - 1 : 0); 1054 1055 mutex_enter(&dn->dn_mtx); 1056 dnode_clear_range(dn, blkid, nblks, tx); 1057 { 1058 free_range_t *rp, *found; 1059 avl_index_t where; 1060 avl_tree_t *tree = &dn->dn_ranges[tx->tx_txg&TXG_MASK]; 1061 1062 /* Add new range to dn_ranges */ 1063 rp = kmem_alloc(sizeof (free_range_t), KM_SLEEP); 1064 rp->fr_blkid = blkid; 1065 rp->fr_nblks = nblks; 1066 found = avl_find(tree, rp, &where); 1067 ASSERT(found == NULL); 1068 avl_insert(tree, rp, where); 1069 dprintf_dnode(dn, "blkid=%llu nblks=%llu txg=%llu\n", 1070 blkid, nblks, tx->tx_txg); 1071 } 1072 mutex_exit(&dn->dn_mtx); 1073 1074 dbuf_free_range(dn, blkid, nblks, tx); 1075 dnode_setdirty(dn, tx); 1076 out: 1077 rw_exit(&dn->dn_struct_rwlock); 1078 } 1079 1080 /* return TRUE if this blkid was freed in a recent txg, or FALSE if it wasn't */ 1081 uint64_t 1082 dnode_block_freed(dnode_t *dn, uint64_t blkid) 1083 { 1084 free_range_t range_tofind; 1085 void *dp = spa_get_dsl(dn->dn_objset->os_spa); 1086 int i; 1087 1088 if (blkid == DB_BONUS_BLKID) 1089 return (FALSE); 1090 1091 /* 1092 * If we're in the process of opening the pool, dp will not be 1093 * set yet, but there shouldn't be anything dirty. 1094 */ 1095 if (dp == NULL) 1096 return (FALSE); 1097 1098 if (dn->dn_free_txg) 1099 return (TRUE); 1100 1101 /* 1102 * If dn_datablkshift is not set, then there's only a single 1103 * block, in which case there will never be a free range so it 1104 * won't matter. 1105 */ 1106 range_tofind.fr_blkid = blkid; 1107 mutex_enter(&dn->dn_mtx); 1108 for (i = 0; i < TXG_SIZE; i++) { 1109 free_range_t *range_found; 1110 avl_index_t idx; 1111 1112 range_found = avl_find(&dn->dn_ranges[i], &range_tofind, &idx); 1113 if (range_found) { 1114 ASSERT(range_found->fr_nblks > 0); 1115 break; 1116 } 1117 range_found = avl_nearest(&dn->dn_ranges[i], idx, AVL_BEFORE); 1118 if (range_found && 1119 range_found->fr_blkid + range_found->fr_nblks > blkid) 1120 break; 1121 } 1122 mutex_exit(&dn->dn_mtx); 1123 return (i < TXG_SIZE); 1124 } 1125 1126 /* call from syncing context when we actually write/free space for this dnode */ 1127 void 1128 dnode_diduse_space(dnode_t *dn, int64_t space) 1129 { 1130 uint64_t sectors; 1131 1132 dprintf_dnode(dn, "dn=%p dnp=%p secphys=%llu space=%lld\n", 1133 dn, dn->dn_phys, 1134 (u_longlong_t)dn->dn_phys->dn_secphys, 1135 (longlong_t)space); 1136 1137 ASSERT(P2PHASE(space, 1<<DEV_BSHIFT) == 0); 1138 1139 mutex_enter(&dn->dn_mtx); 1140 if (space > 0) { 1141 sectors = space >> DEV_BSHIFT; 1142 ASSERT3U(dn->dn_phys->dn_secphys + sectors, >=, 1143 dn->dn_phys->dn_secphys); 1144 dn->dn_phys->dn_secphys += sectors; 1145 } else { 1146 sectors = -space >> DEV_BSHIFT; 1147 ASSERT3U(dn->dn_phys->dn_secphys, >=, sectors); 1148 dn->dn_phys->dn_secphys -= sectors; 1149 } 1150 mutex_exit(&dn->dn_mtx); 1151 } 1152 1153 /* 1154 * Call when we think we're going to write/free space in open context. 1155 * Be conservative (ie. OK to write less than this or free more than 1156 * this, but don't write more or free less). 1157 */ 1158 void 1159 dnode_willuse_space(dnode_t *dn, int64_t space, dmu_tx_t *tx) 1160 { 1161 objset_impl_t *os = dn->dn_objset; 1162 dsl_dataset_t *ds = os->os_dsl_dataset; 1163 1164 if (space > 0) 1165 space = spa_get_asize(os->os_spa, space); 1166 1167 if (ds) 1168 dsl_dir_willuse_space(ds->ds_dir, space, tx); 1169 1170 dmu_tx_willuse_space(tx, space); 1171 } 1172 1173 static int 1174 dnode_next_offset_level(dnode_t *dn, boolean_t hole, uint64_t *offset, 1175 int lvl, uint64_t blkfill) 1176 { 1177 dmu_buf_impl_t *db = NULL; 1178 void *data = NULL; 1179 uint64_t epbs = dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT; 1180 uint64_t epb = 1ULL << epbs; 1181 uint64_t minfill, maxfill; 1182 int i, error, span; 1183 1184 dprintf("probing object %llu offset %llx level %d of %u\n", 1185 dn->dn_object, *offset, lvl, dn->dn_phys->dn_nlevels); 1186 1187 if (lvl == dn->dn_phys->dn_nlevels) { 1188 error = 0; 1189 epb = dn->dn_phys->dn_nblkptr; 1190 data = dn->dn_phys->dn_blkptr; 1191 } else { 1192 uint64_t blkid = dbuf_whichblock(dn, *offset) >> (epbs * lvl); 1193 error = dbuf_hold_impl(dn, lvl, blkid, TRUE, FTAG, &db); 1194 if (error) { 1195 if (error == ENOENT) 1196 return (hole ? 0 : ESRCH); 1197 return (error); 1198 } 1199 dbuf_read_havestruct(db); 1200 data = db->db.db_data; 1201 } 1202 1203 if (lvl == 0) { 1204 dnode_phys_t *dnp = data; 1205 span = DNODE_SHIFT; 1206 ASSERT(dn->dn_type == DMU_OT_DNODE); 1207 1208 for (i = (*offset >> span) & (blkfill - 1); i < blkfill; i++) { 1209 if (!dnp[i].dn_type == hole) 1210 break; 1211 *offset += 1ULL << span; 1212 } 1213 if (i == blkfill) 1214 error = ESRCH; 1215 } else { 1216 blkptr_t *bp = data; 1217 span = (lvl - 1) * epbs + dn->dn_datablkshift; 1218 minfill = 0; 1219 maxfill = blkfill << ((lvl - 1) * epbs); 1220 1221 if (hole) 1222 maxfill--; 1223 else 1224 minfill++; 1225 1226 for (i = (*offset >> span) & ((1ULL << epbs) - 1); 1227 i < epb; i++) { 1228 if (bp[i].blk_fill >= minfill && 1229 bp[i].blk_fill <= maxfill) 1230 break; 1231 *offset += 1ULL << span; 1232 } 1233 if (i >= epb) 1234 error = ESRCH; 1235 } 1236 1237 if (db) 1238 dbuf_remove_ref(db, FTAG); 1239 1240 return (error); 1241 } 1242 1243 /* 1244 * Find the next hole, data, or sparse region at or after *offset. 1245 * The value 'blkfill' tells us how many items we expect to find 1246 * in an L0 data block; this value is 1 for normal objects, 1247 * DNODES_PER_BLOCK for the meta dnode, and some fraction of 1248 * DNODES_PER_BLOCK when searching for sparse regions thereof. 1249 * Examples: 1250 * 1251 * dnode_next_offset(dn, hole, offset, 1, 1); 1252 * Finds the next hole/data in a file. 1253 * Used in dmu_offset_next(). 1254 * 1255 * dnode_next_offset(mdn, hole, offset, 0, DNODES_PER_BLOCK); 1256 * Finds the next free/allocated dnode an objset's meta-dnode. 1257 * Used in dmu_object_next(). 1258 * 1259 * dnode_next_offset(mdn, TRUE, offset, 2, DNODES_PER_BLOCK >> 2); 1260 * Finds the next L2 meta-dnode bp that's at most 1/4 full. 1261 * Used in dmu_object_alloc(). 1262 */ 1263 int 1264 dnode_next_offset(dnode_t *dn, boolean_t hole, uint64_t *offset, 1265 int minlvl, uint64_t blkfill) 1266 { 1267 int lvl, maxlvl; 1268 int error = 0; 1269 uint64_t initial_offset = *offset; 1270 1271 rw_enter(&dn->dn_struct_rwlock, RW_READER); 1272 1273 if (dn->dn_phys->dn_nlevels == 0) { 1274 rw_exit(&dn->dn_struct_rwlock); 1275 return (ESRCH); 1276 } 1277 1278 if (dn->dn_datablkshift == 0) { 1279 if (*offset < dn->dn_datablksz) { 1280 if (hole) 1281 *offset = dn->dn_datablksz; 1282 } else { 1283 error = ESRCH; 1284 } 1285 rw_exit(&dn->dn_struct_rwlock); 1286 return (error); 1287 } 1288 1289 maxlvl = dn->dn_phys->dn_nlevels; 1290 1291 for (lvl = minlvl; lvl <= maxlvl; lvl++) { 1292 error = dnode_next_offset_level(dn, hole, offset, lvl, blkfill); 1293 if (error == 0) 1294 break; 1295 } 1296 1297 while (--lvl >= minlvl && error == 0) 1298 error = dnode_next_offset_level(dn, hole, offset, lvl, blkfill); 1299 1300 rw_exit(&dn->dn_struct_rwlock); 1301 1302 if (initial_offset > *offset) 1303 return (ESRCH); 1304 1305 return (error); 1306 } 1307