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 (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. 23 * Copyright (c) 2013 by Delphix. All rights reserved. 24 */ 25 26 #include <sys/zfs_context.h> 27 #include <sys/dbuf.h> 28 #include <sys/dnode.h> 29 #include <sys/dmu.h> 30 #include <sys/dmu_impl.h> 31 #include <sys/dmu_tx.h> 32 #include <sys/dmu_objset.h> 33 #include <sys/dsl_dir.h> 34 #include <sys/dsl_dataset.h> 35 #include <sys/spa.h> 36 #include <sys/zio.h> 37 #include <sys/dmu_zfetch.h> 38 39 static int free_range_compar(const void *node1, const void *node2); 40 41 static kmem_cache_t *dnode_cache; 42 /* 43 * Define DNODE_STATS to turn on statistic gathering. By default, it is only 44 * turned on when DEBUG is also defined. 45 */ 46 #ifdef DEBUG 47 #define DNODE_STATS 48 #endif /* DEBUG */ 49 50 #ifdef DNODE_STATS 51 #define DNODE_STAT_ADD(stat) ((stat)++) 52 #else 53 #define DNODE_STAT_ADD(stat) /* nothing */ 54 #endif /* DNODE_STATS */ 55 56 static dnode_phys_t dnode_phys_zero; 57 58 int zfs_default_bs = SPA_MINBLOCKSHIFT; 59 int zfs_default_ibs = DN_MAX_INDBLKSHIFT; 60 61 static kmem_cbrc_t dnode_move(void *, void *, size_t, void *); 62 63 /* ARGSUSED */ 64 static int 65 dnode_cons(void *arg, void *unused, int kmflag) 66 { 67 dnode_t *dn = arg; 68 int i; 69 70 rw_init(&dn->dn_struct_rwlock, NULL, RW_DEFAULT, NULL); 71 mutex_init(&dn->dn_mtx, NULL, MUTEX_DEFAULT, NULL); 72 mutex_init(&dn->dn_dbufs_mtx, NULL, MUTEX_DEFAULT, NULL); 73 cv_init(&dn->dn_notxholds, NULL, CV_DEFAULT, NULL); 74 75 /* 76 * Every dbuf has a reference, and dropping a tracked reference is 77 * O(number of references), so don't track dn_holds. 78 */ 79 refcount_create_untracked(&dn->dn_holds); 80 refcount_create(&dn->dn_tx_holds); 81 list_link_init(&dn->dn_link); 82 83 bzero(&dn->dn_next_nblkptr[0], sizeof (dn->dn_next_nblkptr)); 84 bzero(&dn->dn_next_nlevels[0], sizeof (dn->dn_next_nlevels)); 85 bzero(&dn->dn_next_indblkshift[0], sizeof (dn->dn_next_indblkshift)); 86 bzero(&dn->dn_next_bonustype[0], sizeof (dn->dn_next_bonustype)); 87 bzero(&dn->dn_rm_spillblk[0], sizeof (dn->dn_rm_spillblk)); 88 bzero(&dn->dn_next_bonuslen[0], sizeof (dn->dn_next_bonuslen)); 89 bzero(&dn->dn_next_blksz[0], sizeof (dn->dn_next_blksz)); 90 91 for (i = 0; i < TXG_SIZE; i++) { 92 list_link_init(&dn->dn_dirty_link[i]); 93 avl_create(&dn->dn_ranges[i], free_range_compar, 94 sizeof (free_range_t), 95 offsetof(struct free_range, fr_node)); 96 list_create(&dn->dn_dirty_records[i], 97 sizeof (dbuf_dirty_record_t), 98 offsetof(dbuf_dirty_record_t, dr_dirty_node)); 99 } 100 101 dn->dn_allocated_txg = 0; 102 dn->dn_free_txg = 0; 103 dn->dn_assigned_txg = 0; 104 dn->dn_dirtyctx = 0; 105 dn->dn_dirtyctx_firstset = NULL; 106 dn->dn_bonus = NULL; 107 dn->dn_have_spill = B_FALSE; 108 dn->dn_zio = NULL; 109 dn->dn_oldused = 0; 110 dn->dn_oldflags = 0; 111 dn->dn_olduid = 0; 112 dn->dn_oldgid = 0; 113 dn->dn_newuid = 0; 114 dn->dn_newgid = 0; 115 dn->dn_id_flags = 0; 116 117 dn->dn_dbufs_count = 0; 118 list_create(&dn->dn_dbufs, sizeof (dmu_buf_impl_t), 119 offsetof(dmu_buf_impl_t, db_link)); 120 121 dn->dn_moved = 0; 122 return (0); 123 } 124 125 /* ARGSUSED */ 126 static void 127 dnode_dest(void *arg, void *unused) 128 { 129 int i; 130 dnode_t *dn = arg; 131 132 rw_destroy(&dn->dn_struct_rwlock); 133 mutex_destroy(&dn->dn_mtx); 134 mutex_destroy(&dn->dn_dbufs_mtx); 135 cv_destroy(&dn->dn_notxholds); 136 refcount_destroy(&dn->dn_holds); 137 refcount_destroy(&dn->dn_tx_holds); 138 ASSERT(!list_link_active(&dn->dn_link)); 139 140 for (i = 0; i < TXG_SIZE; i++) { 141 ASSERT(!list_link_active(&dn->dn_dirty_link[i])); 142 avl_destroy(&dn->dn_ranges[i]); 143 list_destroy(&dn->dn_dirty_records[i]); 144 ASSERT0(dn->dn_next_nblkptr[i]); 145 ASSERT0(dn->dn_next_nlevels[i]); 146 ASSERT0(dn->dn_next_indblkshift[i]); 147 ASSERT0(dn->dn_next_bonustype[i]); 148 ASSERT0(dn->dn_rm_spillblk[i]); 149 ASSERT0(dn->dn_next_bonuslen[i]); 150 ASSERT0(dn->dn_next_blksz[i]); 151 } 152 153 ASSERT0(dn->dn_allocated_txg); 154 ASSERT0(dn->dn_free_txg); 155 ASSERT0(dn->dn_assigned_txg); 156 ASSERT0(dn->dn_dirtyctx); 157 ASSERT3P(dn->dn_dirtyctx_firstset, ==, NULL); 158 ASSERT3P(dn->dn_bonus, ==, NULL); 159 ASSERT(!dn->dn_have_spill); 160 ASSERT3P(dn->dn_zio, ==, NULL); 161 ASSERT0(dn->dn_oldused); 162 ASSERT0(dn->dn_oldflags); 163 ASSERT0(dn->dn_olduid); 164 ASSERT0(dn->dn_oldgid); 165 ASSERT0(dn->dn_newuid); 166 ASSERT0(dn->dn_newgid); 167 ASSERT0(dn->dn_id_flags); 168 169 ASSERT0(dn->dn_dbufs_count); 170 list_destroy(&dn->dn_dbufs); 171 } 172 173 void 174 dnode_init(void) 175 { 176 ASSERT(dnode_cache == NULL); 177 dnode_cache = kmem_cache_create("dnode_t", 178 sizeof (dnode_t), 179 0, dnode_cons, dnode_dest, NULL, NULL, NULL, 0); 180 kmem_cache_set_move(dnode_cache, dnode_move); 181 } 182 183 void 184 dnode_fini(void) 185 { 186 kmem_cache_destroy(dnode_cache); 187 dnode_cache = NULL; 188 } 189 190 191 #ifdef ZFS_DEBUG 192 void 193 dnode_verify(dnode_t *dn) 194 { 195 int drop_struct_lock = FALSE; 196 197 ASSERT(dn->dn_phys); 198 ASSERT(dn->dn_objset); 199 ASSERT(dn->dn_handle->dnh_dnode == dn); 200 201 ASSERT(DMU_OT_IS_VALID(dn->dn_phys->dn_type)); 202 203 if (!(zfs_flags & ZFS_DEBUG_DNODE_VERIFY)) 204 return; 205 206 if (!RW_WRITE_HELD(&dn->dn_struct_rwlock)) { 207 rw_enter(&dn->dn_struct_rwlock, RW_READER); 208 drop_struct_lock = TRUE; 209 } 210 if (dn->dn_phys->dn_type != DMU_OT_NONE || dn->dn_allocated_txg != 0) { 211 int i; 212 ASSERT3U(dn->dn_indblkshift, >=, 0); 213 ASSERT3U(dn->dn_indblkshift, <=, SPA_MAXBLOCKSHIFT); 214 if (dn->dn_datablkshift) { 215 ASSERT3U(dn->dn_datablkshift, >=, SPA_MINBLOCKSHIFT); 216 ASSERT3U(dn->dn_datablkshift, <=, SPA_MAXBLOCKSHIFT); 217 ASSERT3U(1<<dn->dn_datablkshift, ==, dn->dn_datablksz); 218 } 219 ASSERT3U(dn->dn_nlevels, <=, 30); 220 ASSERT(DMU_OT_IS_VALID(dn->dn_type)); 221 ASSERT3U(dn->dn_nblkptr, >=, 1); 222 ASSERT3U(dn->dn_nblkptr, <=, DN_MAX_NBLKPTR); 223 ASSERT3U(dn->dn_bonuslen, <=, DN_MAX_BONUSLEN); 224 ASSERT3U(dn->dn_datablksz, ==, 225 dn->dn_datablkszsec << SPA_MINBLOCKSHIFT); 226 ASSERT3U(ISP2(dn->dn_datablksz), ==, dn->dn_datablkshift != 0); 227 ASSERT3U((dn->dn_nblkptr - 1) * sizeof (blkptr_t) + 228 dn->dn_bonuslen, <=, DN_MAX_BONUSLEN); 229 for (i = 0; i < TXG_SIZE; i++) { 230 ASSERT3U(dn->dn_next_nlevels[i], <=, dn->dn_nlevels); 231 } 232 } 233 if (dn->dn_phys->dn_type != DMU_OT_NONE) 234 ASSERT3U(dn->dn_phys->dn_nlevels, <=, dn->dn_nlevels); 235 ASSERT(DMU_OBJECT_IS_SPECIAL(dn->dn_object) || dn->dn_dbuf != NULL); 236 if (dn->dn_dbuf != NULL) { 237 ASSERT3P(dn->dn_phys, ==, 238 (dnode_phys_t *)dn->dn_dbuf->db.db_data + 239 (dn->dn_object % (dn->dn_dbuf->db.db_size >> DNODE_SHIFT))); 240 } 241 if (drop_struct_lock) 242 rw_exit(&dn->dn_struct_rwlock); 243 } 244 #endif 245 246 void 247 dnode_byteswap(dnode_phys_t *dnp) 248 { 249 uint64_t *buf64 = (void*)&dnp->dn_blkptr; 250 int i; 251 252 if (dnp->dn_type == DMU_OT_NONE) { 253 bzero(dnp, sizeof (dnode_phys_t)); 254 return; 255 } 256 257 dnp->dn_datablkszsec = BSWAP_16(dnp->dn_datablkszsec); 258 dnp->dn_bonuslen = BSWAP_16(dnp->dn_bonuslen); 259 dnp->dn_maxblkid = BSWAP_64(dnp->dn_maxblkid); 260 dnp->dn_used = BSWAP_64(dnp->dn_used); 261 262 /* 263 * dn_nblkptr is only one byte, so it's OK to read it in either 264 * byte order. We can't read dn_bouslen. 265 */ 266 ASSERT(dnp->dn_indblkshift <= SPA_MAXBLOCKSHIFT); 267 ASSERT(dnp->dn_nblkptr <= DN_MAX_NBLKPTR); 268 for (i = 0; i < dnp->dn_nblkptr * sizeof (blkptr_t)/8; i++) 269 buf64[i] = BSWAP_64(buf64[i]); 270 271 /* 272 * OK to check dn_bonuslen for zero, because it won't matter if 273 * we have the wrong byte order. This is necessary because the 274 * dnode dnode is smaller than a regular dnode. 275 */ 276 if (dnp->dn_bonuslen != 0) { 277 /* 278 * Note that the bonus length calculated here may be 279 * longer than the actual bonus buffer. This is because 280 * we always put the bonus buffer after the last block 281 * pointer (instead of packing it against the end of the 282 * dnode buffer). 283 */ 284 int off = (dnp->dn_nblkptr-1) * sizeof (blkptr_t); 285 size_t len = DN_MAX_BONUSLEN - off; 286 ASSERT(DMU_OT_IS_VALID(dnp->dn_bonustype)); 287 dmu_object_byteswap_t byteswap = 288 DMU_OT_BYTESWAP(dnp->dn_bonustype); 289 dmu_ot_byteswap[byteswap].ob_func(dnp->dn_bonus + off, len); 290 } 291 292 /* Swap SPILL block if we have one */ 293 if (dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) 294 byteswap_uint64_array(&dnp->dn_spill, sizeof (blkptr_t)); 295 296 } 297 298 void 299 dnode_buf_byteswap(void *vbuf, size_t size) 300 { 301 dnode_phys_t *buf = vbuf; 302 int i; 303 304 ASSERT3U(sizeof (dnode_phys_t), ==, (1<<DNODE_SHIFT)); 305 ASSERT((size & (sizeof (dnode_phys_t)-1)) == 0); 306 307 size >>= DNODE_SHIFT; 308 for (i = 0; i < size; i++) { 309 dnode_byteswap(buf); 310 buf++; 311 } 312 } 313 314 static int 315 free_range_compar(const void *node1, const void *node2) 316 { 317 const free_range_t *rp1 = node1; 318 const free_range_t *rp2 = node2; 319 320 if (rp1->fr_blkid < rp2->fr_blkid) 321 return (-1); 322 else if (rp1->fr_blkid > rp2->fr_blkid) 323 return (1); 324 else return (0); 325 } 326 327 void 328 dnode_setbonuslen(dnode_t *dn, int newsize, dmu_tx_t *tx) 329 { 330 ASSERT3U(refcount_count(&dn->dn_holds), >=, 1); 331 332 dnode_setdirty(dn, tx); 333 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 334 ASSERT3U(newsize, <=, DN_MAX_BONUSLEN - 335 (dn->dn_nblkptr-1) * sizeof (blkptr_t)); 336 dn->dn_bonuslen = newsize; 337 if (newsize == 0) 338 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = DN_ZERO_BONUSLEN; 339 else 340 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = dn->dn_bonuslen; 341 rw_exit(&dn->dn_struct_rwlock); 342 } 343 344 void 345 dnode_setbonus_type(dnode_t *dn, dmu_object_type_t newtype, dmu_tx_t *tx) 346 { 347 ASSERT3U(refcount_count(&dn->dn_holds), >=, 1); 348 dnode_setdirty(dn, tx); 349 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 350 dn->dn_bonustype = newtype; 351 dn->dn_next_bonustype[tx->tx_txg & TXG_MASK] = dn->dn_bonustype; 352 rw_exit(&dn->dn_struct_rwlock); 353 } 354 355 void 356 dnode_rm_spill(dnode_t *dn, dmu_tx_t *tx) 357 { 358 ASSERT3U(refcount_count(&dn->dn_holds), >=, 1); 359 ASSERT(RW_WRITE_HELD(&dn->dn_struct_rwlock)); 360 dnode_setdirty(dn, tx); 361 dn->dn_rm_spillblk[tx->tx_txg&TXG_MASK] = DN_KILL_SPILLBLK; 362 dn->dn_have_spill = B_FALSE; 363 } 364 365 static void 366 dnode_setdblksz(dnode_t *dn, int size) 367 { 368 ASSERT0(P2PHASE(size, SPA_MINBLOCKSIZE)); 369 ASSERT3U(size, <=, SPA_MAXBLOCKSIZE); 370 ASSERT3U(size, >=, SPA_MINBLOCKSIZE); 371 ASSERT3U(size >> SPA_MINBLOCKSHIFT, <, 372 1<<(sizeof (dn->dn_phys->dn_datablkszsec) * 8)); 373 dn->dn_datablksz = size; 374 dn->dn_datablkszsec = size >> SPA_MINBLOCKSHIFT; 375 dn->dn_datablkshift = ISP2(size) ? highbit(size - 1) : 0; 376 } 377 378 static dnode_t * 379 dnode_create(objset_t *os, dnode_phys_t *dnp, dmu_buf_impl_t *db, 380 uint64_t object, dnode_handle_t *dnh) 381 { 382 dnode_t *dn = kmem_cache_alloc(dnode_cache, KM_SLEEP); 383 384 ASSERT(!POINTER_IS_VALID(dn->dn_objset)); 385 dn->dn_moved = 0; 386 387 /* 388 * Defer setting dn_objset until the dnode is ready to be a candidate 389 * for the dnode_move() callback. 390 */ 391 dn->dn_object = object; 392 dn->dn_dbuf = db; 393 dn->dn_handle = dnh; 394 dn->dn_phys = dnp; 395 396 if (dnp->dn_datablkszsec) { 397 dnode_setdblksz(dn, dnp->dn_datablkszsec << SPA_MINBLOCKSHIFT); 398 } else { 399 dn->dn_datablksz = 0; 400 dn->dn_datablkszsec = 0; 401 dn->dn_datablkshift = 0; 402 } 403 dn->dn_indblkshift = dnp->dn_indblkshift; 404 dn->dn_nlevels = dnp->dn_nlevels; 405 dn->dn_type = dnp->dn_type; 406 dn->dn_nblkptr = dnp->dn_nblkptr; 407 dn->dn_checksum = dnp->dn_checksum; 408 dn->dn_compress = dnp->dn_compress; 409 dn->dn_bonustype = dnp->dn_bonustype; 410 dn->dn_bonuslen = dnp->dn_bonuslen; 411 dn->dn_maxblkid = dnp->dn_maxblkid; 412 dn->dn_have_spill = ((dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) != 0); 413 dn->dn_id_flags = 0; 414 415 dmu_zfetch_init(&dn->dn_zfetch, dn); 416 417 ASSERT(DMU_OT_IS_VALID(dn->dn_phys->dn_type)); 418 419 mutex_enter(&os->os_lock); 420 list_insert_head(&os->os_dnodes, dn); 421 membar_producer(); 422 /* 423 * Everything else must be valid before assigning dn_objset makes the 424 * dnode eligible for dnode_move(). 425 */ 426 dn->dn_objset = os; 427 mutex_exit(&os->os_lock); 428 429 arc_space_consume(sizeof (dnode_t), ARC_SPACE_OTHER); 430 return (dn); 431 } 432 433 /* 434 * Caller must be holding the dnode handle, which is released upon return. 435 */ 436 static void 437 dnode_destroy(dnode_t *dn) 438 { 439 objset_t *os = dn->dn_objset; 440 441 ASSERT((dn->dn_id_flags & DN_ID_NEW_EXIST) == 0); 442 443 mutex_enter(&os->os_lock); 444 POINTER_INVALIDATE(&dn->dn_objset); 445 list_remove(&os->os_dnodes, dn); 446 mutex_exit(&os->os_lock); 447 448 /* the dnode can no longer move, so we can release the handle */ 449 zrl_remove(&dn->dn_handle->dnh_zrlock); 450 451 dn->dn_allocated_txg = 0; 452 dn->dn_free_txg = 0; 453 dn->dn_assigned_txg = 0; 454 455 dn->dn_dirtyctx = 0; 456 if (dn->dn_dirtyctx_firstset != NULL) { 457 kmem_free(dn->dn_dirtyctx_firstset, 1); 458 dn->dn_dirtyctx_firstset = NULL; 459 } 460 if (dn->dn_bonus != NULL) { 461 list_t evict_list; 462 463 dmu_buf_create_user_evict_list(&evict_list); 464 mutex_enter(&dn->dn_bonus->db_mtx); 465 dbuf_evict(dn->dn_bonus, &evict_list); 466 dmu_buf_destroy_user_evict_list(&evict_list); 467 dn->dn_bonus = NULL; 468 } 469 dn->dn_zio = NULL; 470 471 dn->dn_have_spill = B_FALSE; 472 dn->dn_oldused = 0; 473 dn->dn_oldflags = 0; 474 dn->dn_olduid = 0; 475 dn->dn_oldgid = 0; 476 dn->dn_newuid = 0; 477 dn->dn_newgid = 0; 478 dn->dn_id_flags = 0; 479 480 dmu_zfetch_rele(&dn->dn_zfetch); 481 kmem_cache_free(dnode_cache, dn); 482 arc_space_return(sizeof (dnode_t), ARC_SPACE_OTHER); 483 } 484 485 void 486 dnode_allocate(dnode_t *dn, dmu_object_type_t ot, int blocksize, int ibs, 487 dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx) 488 { 489 int i; 490 491 if (blocksize == 0) 492 blocksize = 1 << zfs_default_bs; 493 else if (blocksize > SPA_MAXBLOCKSIZE) 494 blocksize = SPA_MAXBLOCKSIZE; 495 else 496 blocksize = P2ROUNDUP(blocksize, SPA_MINBLOCKSIZE); 497 498 if (ibs == 0) 499 ibs = zfs_default_ibs; 500 501 ibs = MIN(MAX(ibs, DN_MIN_INDBLKSHIFT), DN_MAX_INDBLKSHIFT); 502 503 dprintf("os=%p obj=%llu txg=%llu blocksize=%d ibs=%d\n", dn->dn_objset, 504 dn->dn_object, tx->tx_txg, blocksize, ibs); 505 506 ASSERT(dn->dn_type == DMU_OT_NONE); 507 ASSERT(bcmp(dn->dn_phys, &dnode_phys_zero, sizeof (dnode_phys_t)) == 0); 508 ASSERT(dn->dn_phys->dn_type == DMU_OT_NONE); 509 ASSERT(ot != DMU_OT_NONE); 510 ASSERT(DMU_OT_IS_VALID(ot)); 511 ASSERT((bonustype == DMU_OT_NONE && bonuslen == 0) || 512 (bonustype == DMU_OT_SA && bonuslen == 0) || 513 (bonustype != DMU_OT_NONE && bonuslen != 0)); 514 ASSERT(DMU_OT_IS_VALID(bonustype)); 515 ASSERT3U(bonuslen, <=, DN_MAX_BONUSLEN); 516 ASSERT(dn->dn_type == DMU_OT_NONE); 517 ASSERT0(dn->dn_maxblkid); 518 ASSERT0(dn->dn_allocated_txg); 519 ASSERT0(dn->dn_assigned_txg); 520 ASSERT(refcount_is_zero(&dn->dn_tx_holds)); 521 ASSERT3U(refcount_count(&dn->dn_holds), <=, 1); 522 ASSERT3P(list_head(&dn->dn_dbufs), ==, NULL); 523 524 for (i = 0; i < TXG_SIZE; i++) { 525 ASSERT0(dn->dn_next_nblkptr[i]); 526 ASSERT0(dn->dn_next_nlevels[i]); 527 ASSERT0(dn->dn_next_indblkshift[i]); 528 ASSERT0(dn->dn_next_bonuslen[i]); 529 ASSERT0(dn->dn_next_bonustype[i]); 530 ASSERT0(dn->dn_rm_spillblk[i]); 531 ASSERT0(dn->dn_next_blksz[i]); 532 ASSERT(!list_link_active(&dn->dn_dirty_link[i])); 533 ASSERT3P(list_head(&dn->dn_dirty_records[i]), ==, NULL); 534 ASSERT0(avl_numnodes(&dn->dn_ranges[i])); 535 } 536 537 dn->dn_type = ot; 538 dnode_setdblksz(dn, blocksize); 539 dn->dn_indblkshift = ibs; 540 dn->dn_nlevels = 1; 541 if (bonustype == DMU_OT_SA) /* Maximize bonus space for SA */ 542 dn->dn_nblkptr = 1; 543 else 544 dn->dn_nblkptr = 1 + 545 ((DN_MAX_BONUSLEN - bonuslen) >> SPA_BLKPTRSHIFT); 546 dn->dn_bonustype = bonustype; 547 dn->dn_bonuslen = bonuslen; 548 dn->dn_checksum = ZIO_CHECKSUM_INHERIT; 549 dn->dn_compress = ZIO_COMPRESS_INHERIT; 550 dn->dn_dirtyctx = 0; 551 552 dn->dn_free_txg = 0; 553 if (dn->dn_dirtyctx_firstset) { 554 kmem_free(dn->dn_dirtyctx_firstset, 1); 555 dn->dn_dirtyctx_firstset = NULL; 556 } 557 558 dn->dn_allocated_txg = tx->tx_txg; 559 dn->dn_id_flags = 0; 560 561 dnode_setdirty(dn, tx); 562 dn->dn_next_indblkshift[tx->tx_txg & TXG_MASK] = ibs; 563 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = dn->dn_bonuslen; 564 dn->dn_next_bonustype[tx->tx_txg & TXG_MASK] = dn->dn_bonustype; 565 dn->dn_next_blksz[tx->tx_txg & TXG_MASK] = dn->dn_datablksz; 566 } 567 568 void 569 dnode_reallocate(dnode_t *dn, dmu_object_type_t ot, int blocksize, 570 dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx) 571 { 572 int nblkptr; 573 574 ASSERT3U(blocksize, >=, SPA_MINBLOCKSIZE); 575 ASSERT3U(blocksize, <=, SPA_MAXBLOCKSIZE); 576 ASSERT0(blocksize % SPA_MINBLOCKSIZE); 577 ASSERT(dn->dn_object != DMU_META_DNODE_OBJECT || dmu_tx_private_ok(tx)); 578 ASSERT(tx->tx_txg != 0); 579 ASSERT((bonustype == DMU_OT_NONE && bonuslen == 0) || 580 (bonustype != DMU_OT_NONE && bonuslen != 0) || 581 (bonustype == DMU_OT_SA && bonuslen == 0)); 582 ASSERT(DMU_OT_IS_VALID(bonustype)); 583 ASSERT3U(bonuslen, <=, DN_MAX_BONUSLEN); 584 585 /* clean up any unreferenced dbufs */ 586 dnode_evict_dbufs(dn); 587 588 dn->dn_id_flags = 0; 589 590 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 591 dnode_setdirty(dn, tx); 592 if (dn->dn_datablksz != blocksize) { 593 /* change blocksize */ 594 ASSERT(dn->dn_maxblkid == 0 && 595 (BP_IS_HOLE(&dn->dn_phys->dn_blkptr[0]) || 596 dnode_block_freed(dn, 0))); 597 dnode_setdblksz(dn, blocksize); 598 dn->dn_next_blksz[tx->tx_txg&TXG_MASK] = blocksize; 599 } 600 if (dn->dn_bonuslen != bonuslen) 601 dn->dn_next_bonuslen[tx->tx_txg&TXG_MASK] = bonuslen; 602 603 if (bonustype == DMU_OT_SA) /* Maximize bonus space for SA */ 604 nblkptr = 1; 605 else 606 nblkptr = 1 + ((DN_MAX_BONUSLEN - bonuslen) >> SPA_BLKPTRSHIFT); 607 if (dn->dn_bonustype != bonustype) 608 dn->dn_next_bonustype[tx->tx_txg&TXG_MASK] = bonustype; 609 if (dn->dn_nblkptr != nblkptr) 610 dn->dn_next_nblkptr[tx->tx_txg&TXG_MASK] = nblkptr; 611 if (dn->dn_phys->dn_flags & DNODE_FLAG_SPILL_BLKPTR) { 612 dbuf_rm_spill(dn, tx); 613 dnode_rm_spill(dn, tx); 614 } 615 rw_exit(&dn->dn_struct_rwlock); 616 617 /* change type */ 618 dn->dn_type = ot; 619 620 /* change bonus size and type */ 621 mutex_enter(&dn->dn_mtx); 622 dn->dn_bonustype = bonustype; 623 dn->dn_bonuslen = bonuslen; 624 dn->dn_nblkptr = nblkptr; 625 dn->dn_checksum = ZIO_CHECKSUM_INHERIT; 626 dn->dn_compress = ZIO_COMPRESS_INHERIT; 627 ASSERT3U(dn->dn_nblkptr, <=, DN_MAX_NBLKPTR); 628 629 /* fix up the bonus db_size */ 630 if (dn->dn_bonus) { 631 dn->dn_bonus->db.db_size = 632 DN_MAX_BONUSLEN - (dn->dn_nblkptr-1) * sizeof (blkptr_t); 633 ASSERT(dn->dn_bonuslen <= dn->dn_bonus->db.db_size); 634 } 635 636 dn->dn_allocated_txg = tx->tx_txg; 637 mutex_exit(&dn->dn_mtx); 638 } 639 640 #ifdef DNODE_STATS 641 static struct { 642 uint64_t dms_dnode_invalid; 643 uint64_t dms_dnode_recheck1; 644 uint64_t dms_dnode_recheck2; 645 uint64_t dms_dnode_special; 646 uint64_t dms_dnode_handle; 647 uint64_t dms_dnode_rwlock; 648 uint64_t dms_dnode_active; 649 } dnode_move_stats; 650 #endif /* DNODE_STATS */ 651 652 static void 653 dnode_move_impl(dnode_t *odn, dnode_t *ndn) 654 { 655 int i; 656 657 ASSERT(!RW_LOCK_HELD(&odn->dn_struct_rwlock)); 658 ASSERT(MUTEX_NOT_HELD(&odn->dn_mtx)); 659 ASSERT(MUTEX_NOT_HELD(&odn->dn_dbufs_mtx)); 660 ASSERT(!RW_LOCK_HELD(&odn->dn_zfetch.zf_rwlock)); 661 662 /* Copy fields. */ 663 ndn->dn_objset = odn->dn_objset; 664 ndn->dn_object = odn->dn_object; 665 ndn->dn_dbuf = odn->dn_dbuf; 666 ndn->dn_handle = odn->dn_handle; 667 ndn->dn_phys = odn->dn_phys; 668 ndn->dn_type = odn->dn_type; 669 ndn->dn_bonuslen = odn->dn_bonuslen; 670 ndn->dn_bonustype = odn->dn_bonustype; 671 ndn->dn_nblkptr = odn->dn_nblkptr; 672 ndn->dn_checksum = odn->dn_checksum; 673 ndn->dn_compress = odn->dn_compress; 674 ndn->dn_nlevels = odn->dn_nlevels; 675 ndn->dn_indblkshift = odn->dn_indblkshift; 676 ndn->dn_datablkshift = odn->dn_datablkshift; 677 ndn->dn_datablkszsec = odn->dn_datablkszsec; 678 ndn->dn_datablksz = odn->dn_datablksz; 679 ndn->dn_maxblkid = odn->dn_maxblkid; 680 bcopy(&odn->dn_next_nblkptr[0], &ndn->dn_next_nblkptr[0], 681 sizeof (odn->dn_next_nblkptr)); 682 bcopy(&odn->dn_next_nlevels[0], &ndn->dn_next_nlevels[0], 683 sizeof (odn->dn_next_nlevels)); 684 bcopy(&odn->dn_next_indblkshift[0], &ndn->dn_next_indblkshift[0], 685 sizeof (odn->dn_next_indblkshift)); 686 bcopy(&odn->dn_next_bonustype[0], &ndn->dn_next_bonustype[0], 687 sizeof (odn->dn_next_bonustype)); 688 bcopy(&odn->dn_rm_spillblk[0], &ndn->dn_rm_spillblk[0], 689 sizeof (odn->dn_rm_spillblk)); 690 bcopy(&odn->dn_next_bonuslen[0], &ndn->dn_next_bonuslen[0], 691 sizeof (odn->dn_next_bonuslen)); 692 bcopy(&odn->dn_next_blksz[0], &ndn->dn_next_blksz[0], 693 sizeof (odn->dn_next_blksz)); 694 for (i = 0; i < TXG_SIZE; i++) { 695 list_move_tail(&ndn->dn_dirty_records[i], 696 &odn->dn_dirty_records[i]); 697 } 698 bcopy(&odn->dn_ranges[0], &ndn->dn_ranges[0], sizeof (odn->dn_ranges)); 699 ndn->dn_allocated_txg = odn->dn_allocated_txg; 700 ndn->dn_free_txg = odn->dn_free_txg; 701 ndn->dn_assigned_txg = odn->dn_assigned_txg; 702 ndn->dn_dirtyctx = odn->dn_dirtyctx; 703 ndn->dn_dirtyctx_firstset = odn->dn_dirtyctx_firstset; 704 ASSERT(refcount_count(&odn->dn_tx_holds) == 0); 705 refcount_transfer(&ndn->dn_holds, &odn->dn_holds); 706 ASSERT(list_is_empty(&ndn->dn_dbufs)); 707 list_move_tail(&ndn->dn_dbufs, &odn->dn_dbufs); 708 ndn->dn_dbufs_count = odn->dn_dbufs_count; 709 ndn->dn_bonus = odn->dn_bonus; 710 ndn->dn_have_spill = odn->dn_have_spill; 711 ndn->dn_zio = odn->dn_zio; 712 ndn->dn_oldused = odn->dn_oldused; 713 ndn->dn_oldflags = odn->dn_oldflags; 714 ndn->dn_olduid = odn->dn_olduid; 715 ndn->dn_oldgid = odn->dn_oldgid; 716 ndn->dn_newuid = odn->dn_newuid; 717 ndn->dn_newgid = odn->dn_newgid; 718 ndn->dn_id_flags = odn->dn_id_flags; 719 dmu_zfetch_init(&ndn->dn_zfetch, NULL); 720 list_move_tail(&ndn->dn_zfetch.zf_stream, &odn->dn_zfetch.zf_stream); 721 ndn->dn_zfetch.zf_dnode = odn->dn_zfetch.zf_dnode; 722 ndn->dn_zfetch.zf_stream_cnt = odn->dn_zfetch.zf_stream_cnt; 723 ndn->dn_zfetch.zf_alloc_fail = odn->dn_zfetch.zf_alloc_fail; 724 725 /* 726 * Update back pointers. Updating the handle fixes the back pointer of 727 * every descendant dbuf as well as the bonus dbuf. 728 */ 729 ASSERT(ndn->dn_handle->dnh_dnode == odn); 730 ndn->dn_handle->dnh_dnode = ndn; 731 if (ndn->dn_zfetch.zf_dnode == odn) { 732 ndn->dn_zfetch.zf_dnode = ndn; 733 } 734 735 /* 736 * Invalidate the original dnode by clearing all of its back pointers. 737 */ 738 odn->dn_dbuf = NULL; 739 odn->dn_handle = NULL; 740 list_create(&odn->dn_dbufs, sizeof (dmu_buf_impl_t), 741 offsetof(dmu_buf_impl_t, db_link)); 742 odn->dn_dbufs_count = 0; 743 odn->dn_bonus = NULL; 744 odn->dn_zfetch.zf_dnode = NULL; 745 746 /* 747 * Set the low bit of the objset pointer to ensure that dnode_move() 748 * recognizes the dnode as invalid in any subsequent callback. 749 */ 750 POINTER_INVALIDATE(&odn->dn_objset); 751 752 /* 753 * Satisfy the destructor. 754 */ 755 for (i = 0; i < TXG_SIZE; i++) { 756 list_create(&odn->dn_dirty_records[i], 757 sizeof (dbuf_dirty_record_t), 758 offsetof(dbuf_dirty_record_t, dr_dirty_node)); 759 odn->dn_ranges[i].avl_root = NULL; 760 odn->dn_ranges[i].avl_numnodes = 0; 761 odn->dn_next_nlevels[i] = 0; 762 odn->dn_next_indblkshift[i] = 0; 763 odn->dn_next_bonustype[i] = 0; 764 odn->dn_rm_spillblk[i] = 0; 765 odn->dn_next_bonuslen[i] = 0; 766 odn->dn_next_blksz[i] = 0; 767 } 768 odn->dn_allocated_txg = 0; 769 odn->dn_free_txg = 0; 770 odn->dn_assigned_txg = 0; 771 odn->dn_dirtyctx = 0; 772 odn->dn_dirtyctx_firstset = NULL; 773 odn->dn_have_spill = B_FALSE; 774 odn->dn_zio = NULL; 775 odn->dn_oldused = 0; 776 odn->dn_oldflags = 0; 777 odn->dn_olduid = 0; 778 odn->dn_oldgid = 0; 779 odn->dn_newuid = 0; 780 odn->dn_newgid = 0; 781 odn->dn_id_flags = 0; 782 783 /* 784 * Mark the dnode. 785 */ 786 ndn->dn_moved = 1; 787 odn->dn_moved = (uint8_t)-1; 788 } 789 790 #ifdef _KERNEL 791 /*ARGSUSED*/ 792 static kmem_cbrc_t 793 dnode_move(void *buf, void *newbuf, size_t size, void *arg) 794 { 795 dnode_t *odn = buf, *ndn = newbuf; 796 objset_t *os; 797 int64_t refcount; 798 uint32_t dbufs; 799 800 /* 801 * The dnode is on the objset's list of known dnodes if the objset 802 * pointer is valid. We set the low bit of the objset pointer when 803 * freeing the dnode to invalidate it, and the memory patterns written 804 * by kmem (baddcafe and deadbeef) set at least one of the two low bits. 805 * A newly created dnode sets the objset pointer last of all to indicate 806 * that the dnode is known and in a valid state to be moved by this 807 * function. 808 */ 809 os = odn->dn_objset; 810 if (!POINTER_IS_VALID(os)) { 811 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_invalid); 812 return (KMEM_CBRC_DONT_KNOW); 813 } 814 815 /* 816 * Ensure that the objset does not go away during the move. 817 */ 818 rw_enter(&os_lock, RW_WRITER); 819 if (os != odn->dn_objset) { 820 rw_exit(&os_lock); 821 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_recheck1); 822 return (KMEM_CBRC_DONT_KNOW); 823 } 824 825 /* 826 * If the dnode is still valid, then so is the objset. We know that no 827 * valid objset can be freed while we hold os_lock, so we can safely 828 * ensure that the objset remains in use. 829 */ 830 mutex_enter(&os->os_lock); 831 832 /* 833 * Recheck the objset pointer in case the dnode was removed just before 834 * acquiring the lock. 835 */ 836 if (os != odn->dn_objset) { 837 mutex_exit(&os->os_lock); 838 rw_exit(&os_lock); 839 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_recheck2); 840 return (KMEM_CBRC_DONT_KNOW); 841 } 842 843 /* 844 * At this point we know that as long as we hold os->os_lock, the dnode 845 * cannot be freed and fields within the dnode can be safely accessed. 846 * The objset listing this dnode cannot go away as long as this dnode is 847 * on its list. 848 */ 849 rw_exit(&os_lock); 850 if (DMU_OBJECT_IS_SPECIAL(odn->dn_object)) { 851 mutex_exit(&os->os_lock); 852 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_special); 853 return (KMEM_CBRC_NO); 854 } 855 ASSERT(odn->dn_dbuf != NULL); /* only "special" dnodes have no parent */ 856 857 /* 858 * Lock the dnode handle to prevent the dnode from obtaining any new 859 * holds. This also prevents the descendant dbufs and the bonus dbuf 860 * from accessing the dnode, so that we can discount their holds. The 861 * handle is safe to access because we know that while the dnode cannot 862 * go away, neither can its handle. Once we hold dnh_zrlock, we can 863 * safely move any dnode referenced only by dbufs. 864 */ 865 if (!zrl_tryenter(&odn->dn_handle->dnh_zrlock)) { 866 mutex_exit(&os->os_lock); 867 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_handle); 868 return (KMEM_CBRC_LATER); 869 } 870 871 /* 872 * Ensure a consistent view of the dnode's holds and the dnode's dbufs. 873 * We need to guarantee that there is a hold for every dbuf in order to 874 * determine whether the dnode is actively referenced. Falsely matching 875 * a dbuf to an active hold would lead to an unsafe move. It's possible 876 * that a thread already having an active dnode hold is about to add a 877 * dbuf, and we can't compare hold and dbuf counts while the add is in 878 * progress. 879 */ 880 if (!rw_tryenter(&odn->dn_struct_rwlock, RW_WRITER)) { 881 zrl_exit(&odn->dn_handle->dnh_zrlock); 882 mutex_exit(&os->os_lock); 883 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_rwlock); 884 return (KMEM_CBRC_LATER); 885 } 886 887 /* 888 * A dbuf may be removed (evicted) without an active dnode hold. In that 889 * case, the dbuf count is decremented under the handle lock before the 890 * dbuf's hold is released. This order ensures that if we count the hold 891 * after the dbuf is removed but before its hold is released, we will 892 * treat the unmatched hold as active and exit safely. If we count the 893 * hold before the dbuf is removed, the hold is discounted, and the 894 * removal is blocked until the move completes. 895 */ 896 refcount = refcount_count(&odn->dn_holds); 897 ASSERT(refcount >= 0); 898 dbufs = odn->dn_dbufs_count; 899 900 /* We can't have more dbufs than dnode holds. */ 901 ASSERT3U(dbufs, <=, refcount); 902 DTRACE_PROBE3(dnode__move, dnode_t *, odn, int64_t, refcount, 903 uint32_t, dbufs); 904 905 if (refcount > dbufs) { 906 rw_exit(&odn->dn_struct_rwlock); 907 zrl_exit(&odn->dn_handle->dnh_zrlock); 908 mutex_exit(&os->os_lock); 909 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_active); 910 return (KMEM_CBRC_LATER); 911 } 912 913 rw_exit(&odn->dn_struct_rwlock); 914 915 /* 916 * At this point we know that anyone with a hold on the dnode is not 917 * actively referencing it. The dnode is known and in a valid state to 918 * move. We're holding the locks needed to execute the critical section. 919 */ 920 dnode_move_impl(odn, ndn); 921 922 list_link_replace(&odn->dn_link, &ndn->dn_link); 923 /* If the dnode was safe to move, the refcount cannot have changed. */ 924 ASSERT(refcount == refcount_count(&ndn->dn_holds)); 925 ASSERT(dbufs == ndn->dn_dbufs_count); 926 zrl_exit(&ndn->dn_handle->dnh_zrlock); /* handle has moved */ 927 mutex_exit(&os->os_lock); 928 929 return (KMEM_CBRC_YES); 930 } 931 #endif /* _KERNEL */ 932 933 void 934 dnode_special_close(dnode_handle_t *dnh) 935 { 936 dnode_t *dn = dnh->dnh_dnode; 937 938 /* 939 * Wait for final references to the dnode to clear. This can 940 * only happen if the arc is asyncronously evicting state that 941 * has a hold on this dnode while we are trying to evict this 942 * dnode. 943 */ 944 while (refcount_count(&dn->dn_holds) > 0) 945 delay(1); 946 zrl_add(&dnh->dnh_zrlock); 947 dnode_destroy(dn); /* implicit zrl_remove() */ 948 zrl_destroy(&dnh->dnh_zrlock); 949 dnh->dnh_dnode = NULL; 950 } 951 952 dnode_t * 953 dnode_special_open(objset_t *os, dnode_phys_t *dnp, uint64_t object, 954 dnode_handle_t *dnh) 955 { 956 dnode_t *dn = dnode_create(os, dnp, NULL, object, dnh); 957 dnh->dnh_dnode = dn; 958 zrl_init(&dnh->dnh_zrlock); 959 DNODE_VERIFY(dn); 960 return (dn); 961 } 962 963 static void 964 dnode_buf_pageout(dmu_buf_user_t *dbu) 965 { 966 dnode_children_t *children_dnodes = (dnode_children_t *)dbu; 967 int i; 968 969 for (i = 0; i < children_dnodes->dnc_count; i++) { 970 dnode_handle_t *dnh = &children_dnodes->dnc_children[i]; 971 dnode_t *dn; 972 973 /* 974 * The dnode handle lock guards against the dnode moving to 975 * another valid address, so there is no need here to guard 976 * against changes to or from NULL. 977 */ 978 if (dnh->dnh_dnode == NULL) { 979 zrl_destroy(&dnh->dnh_zrlock); 980 continue; 981 } 982 983 zrl_add(&dnh->dnh_zrlock); 984 dn = dnh->dnh_dnode; 985 /* 986 * If there are holds on this dnode, then there should 987 * be holds on the dnode's containing dbuf as well; thus 988 * it wouldn't be eligible for eviction and this function 989 * would not have been called. 990 */ 991 ASSERT(refcount_is_zero(&dn->dn_holds)); 992 ASSERT(refcount_is_zero(&dn->dn_tx_holds)); 993 994 dnode_destroy(dn); /* implicit zrl_remove() */ 995 zrl_destroy(&dnh->dnh_zrlock); 996 dnh->dnh_dnode = NULL; 997 } 998 kmem_free(children_dnodes, sizeof (dnode_children_t) + 999 (children_dnodes->dnc_count - 1) * sizeof (dnode_handle_t)); 1000 } 1001 1002 /* 1003 * errors: 1004 * EINVAL - invalid object number. 1005 * EIO - i/o error. 1006 * succeeds even for free dnodes. 1007 */ 1008 int 1009 dnode_hold_impl(objset_t *os, uint64_t object, int flag, 1010 void *tag, dnode_t **dnp) 1011 { 1012 int epb, idx, err; 1013 int drop_struct_lock = FALSE; 1014 int type; 1015 uint64_t blk; 1016 dnode_t *mdn, *dn; 1017 dmu_buf_impl_t *db; 1018 dnode_children_t *children_dnodes; 1019 dnode_handle_t *dnh; 1020 1021 /* 1022 * If you are holding the spa config lock as writer, you shouldn't 1023 * be asking the DMU to do *anything* unless it's the root pool 1024 * which may require us to read from the root filesystem while 1025 * holding some (not all) of the locks as writer. 1026 */ 1027 ASSERT(spa_config_held(os->os_spa, SCL_ALL, RW_WRITER) == 0 || 1028 (spa_is_root(os->os_spa) && 1029 spa_config_held(os->os_spa, SCL_STATE, RW_WRITER))); 1030 1031 if (object == DMU_USERUSED_OBJECT || object == DMU_GROUPUSED_OBJECT) { 1032 dn = (object == DMU_USERUSED_OBJECT) ? 1033 DMU_USERUSED_DNODE(os) : DMU_GROUPUSED_DNODE(os); 1034 if (dn == NULL) 1035 return (SET_ERROR(ENOENT)); 1036 type = dn->dn_type; 1037 if ((flag & DNODE_MUST_BE_ALLOCATED) && type == DMU_OT_NONE) 1038 return (SET_ERROR(ENOENT)); 1039 if ((flag & DNODE_MUST_BE_FREE) && type != DMU_OT_NONE) 1040 return (SET_ERROR(EEXIST)); 1041 DNODE_VERIFY(dn); 1042 (void) refcount_add(&dn->dn_holds, tag); 1043 *dnp = dn; 1044 return (0); 1045 } 1046 1047 if (object == 0 || object >= DN_MAX_OBJECT) 1048 return (SET_ERROR(EINVAL)); 1049 1050 mdn = DMU_META_DNODE(os); 1051 ASSERT(mdn->dn_object == DMU_META_DNODE_OBJECT); 1052 1053 DNODE_VERIFY(mdn); 1054 1055 if (!RW_WRITE_HELD(&mdn->dn_struct_rwlock)) { 1056 rw_enter(&mdn->dn_struct_rwlock, RW_READER); 1057 drop_struct_lock = TRUE; 1058 } 1059 1060 blk = dbuf_whichblock(mdn, object * sizeof (dnode_phys_t)); 1061 1062 db = dbuf_hold(mdn, blk, FTAG); 1063 if (drop_struct_lock) 1064 rw_exit(&mdn->dn_struct_rwlock); 1065 if (db == NULL) 1066 return (SET_ERROR(EIO)); 1067 err = dbuf_read(db, NULL, DB_RF_CANFAIL); 1068 if (err) { 1069 dbuf_rele(db, FTAG); 1070 return (err); 1071 } 1072 1073 ASSERT3U(db->db.db_size, >=, 1<<DNODE_SHIFT); 1074 epb = db->db.db_size >> DNODE_SHIFT; 1075 1076 idx = object & (epb-1); 1077 1078 ASSERT(DB_DNODE(db)->dn_type == DMU_OT_DNODE); 1079 children_dnodes = (dnode_children_t *)dmu_buf_get_user(&db->db); 1080 if (children_dnodes == NULL) { 1081 int i; 1082 dnode_children_t *winner; 1083 children_dnodes = kmem_alloc(sizeof (dnode_children_t) + 1084 (epb - 1) * sizeof (dnode_handle_t), KM_SLEEP); 1085 children_dnodes->dnc_count = epb; 1086 dnh = &children_dnodes->dnc_children[0]; 1087 for (i = 0; i < epb; i++) { 1088 zrl_init(&dnh[i].dnh_zrlock); 1089 dnh[i].dnh_dnode = NULL; 1090 } 1091 dmu_buf_init_user(&children_dnodes->db_evict, 1092 dnode_buf_pageout); 1093 winner = (dnode_children_t *) 1094 dmu_buf_set_user(&db->db, &children_dnodes->db_evict); 1095 if (winner) { 1096 kmem_free(children_dnodes, sizeof (dnode_children_t) + 1097 (epb - 1) * sizeof (dnode_handle_t)); 1098 children_dnodes = winner; 1099 } 1100 } 1101 ASSERT(children_dnodes->dnc_count == epb); 1102 1103 dnh = &children_dnodes->dnc_children[idx]; 1104 zrl_add(&dnh->dnh_zrlock); 1105 if ((dn = dnh->dnh_dnode) == NULL) { 1106 dnode_phys_t *phys = (dnode_phys_t *)db->db.db_data+idx; 1107 dnode_t *winner; 1108 1109 dn = dnode_create(os, phys, db, object, dnh); 1110 winner = atomic_cas_ptr(&dnh->dnh_dnode, NULL, dn); 1111 if (winner != NULL) { 1112 zrl_add(&dnh->dnh_zrlock); 1113 dnode_destroy(dn); /* implicit zrl_remove() */ 1114 dn = winner; 1115 } 1116 } 1117 1118 mutex_enter(&dn->dn_mtx); 1119 type = dn->dn_type; 1120 if (dn->dn_free_txg || 1121 ((flag & DNODE_MUST_BE_ALLOCATED) && type == DMU_OT_NONE) || 1122 ((flag & DNODE_MUST_BE_FREE) && 1123 (type != DMU_OT_NONE || !refcount_is_zero(&dn->dn_holds)))) { 1124 mutex_exit(&dn->dn_mtx); 1125 zrl_remove(&dnh->dnh_zrlock); 1126 dbuf_rele(db, FTAG); 1127 return (type == DMU_OT_NONE ? ENOENT : EEXIST); 1128 } 1129 mutex_exit(&dn->dn_mtx); 1130 1131 if (refcount_add(&dn->dn_holds, tag) == 1) 1132 dbuf_add_ref(db, dnh); 1133 /* Now we can rely on the hold to prevent the dnode from moving. */ 1134 zrl_remove(&dnh->dnh_zrlock); 1135 1136 DNODE_VERIFY(dn); 1137 ASSERT3P(dn->dn_dbuf, ==, db); 1138 ASSERT3U(dn->dn_object, ==, object); 1139 dbuf_rele(db, FTAG); 1140 1141 *dnp = dn; 1142 return (0); 1143 } 1144 1145 /* 1146 * Return held dnode if the object is allocated, NULL if not. 1147 */ 1148 int 1149 dnode_hold(objset_t *os, uint64_t object, void *tag, dnode_t **dnp) 1150 { 1151 return (dnode_hold_impl(os, object, DNODE_MUST_BE_ALLOCATED, tag, dnp)); 1152 } 1153 1154 /* 1155 * Can only add a reference if there is already at least one 1156 * reference on the dnode. Returns FALSE if unable to add a 1157 * new reference. 1158 */ 1159 boolean_t 1160 dnode_add_ref(dnode_t *dn, void *tag) 1161 { 1162 mutex_enter(&dn->dn_mtx); 1163 if (refcount_is_zero(&dn->dn_holds)) { 1164 mutex_exit(&dn->dn_mtx); 1165 return (FALSE); 1166 } 1167 VERIFY(1 < refcount_add(&dn->dn_holds, tag)); 1168 mutex_exit(&dn->dn_mtx); 1169 return (TRUE); 1170 } 1171 1172 void 1173 dnode_rele(dnode_t *dn, void *tag) 1174 { 1175 uint64_t refs; 1176 /* Get while the hold prevents the dnode from moving. */ 1177 dmu_buf_impl_t *db = dn->dn_dbuf; 1178 dnode_handle_t *dnh = dn->dn_handle; 1179 1180 mutex_enter(&dn->dn_mtx); 1181 refs = refcount_remove(&dn->dn_holds, tag); 1182 mutex_exit(&dn->dn_mtx); 1183 1184 /* 1185 * It's unsafe to release the last hold on a dnode by dnode_rele() or 1186 * indirectly by dbuf_rele() while relying on the dnode handle to 1187 * prevent the dnode from moving, since releasing the last hold could 1188 * result in the dnode's parent dbuf evicting its dnode handles. For 1189 * that reason anyone calling dnode_rele() or dbuf_rele() without some 1190 * other direct or indirect hold on the dnode must first drop the dnode 1191 * handle. 1192 */ 1193 ASSERT(refs > 0 || dnh->dnh_zrlock.zr_owner != curthread); 1194 1195 /* NOTE: the DNODE_DNODE does not have a dn_dbuf */ 1196 if (refs == 0 && db != NULL) { 1197 /* 1198 * Another thread could add a hold to the dnode handle in 1199 * dnode_hold_impl() while holding the parent dbuf. Since the 1200 * hold on the parent dbuf prevents the handle from being 1201 * destroyed, the hold on the handle is OK. We can't yet assert 1202 * that the handle has zero references, but that will be 1203 * asserted anyway when the handle gets destroyed. 1204 */ 1205 dbuf_rele(db, dnh); 1206 } 1207 } 1208 1209 void 1210 dnode_setdirty(dnode_t *dn, dmu_tx_t *tx) 1211 { 1212 objset_t *os = dn->dn_objset; 1213 uint64_t txg = tx->tx_txg; 1214 1215 if (DMU_OBJECT_IS_SPECIAL(dn->dn_object)) { 1216 dsl_dataset_dirty(os->os_dsl_dataset, tx); 1217 return; 1218 } 1219 1220 DNODE_VERIFY(dn); 1221 1222 #ifdef ZFS_DEBUG 1223 mutex_enter(&dn->dn_mtx); 1224 ASSERT(dn->dn_phys->dn_type || dn->dn_allocated_txg); 1225 ASSERT(dn->dn_free_txg == 0 || dn->dn_free_txg >= txg); 1226 mutex_exit(&dn->dn_mtx); 1227 #endif 1228 1229 /* 1230 * Determine old uid/gid when necessary 1231 */ 1232 dmu_objset_userquota_get_ids(dn, B_TRUE, tx); 1233 1234 mutex_enter(&os->os_lock); 1235 1236 /* 1237 * If we are already marked dirty, we're done. 1238 */ 1239 if (list_link_active(&dn->dn_dirty_link[txg & TXG_MASK])) { 1240 mutex_exit(&os->os_lock); 1241 return; 1242 } 1243 1244 ASSERT(!refcount_is_zero(&dn->dn_holds) || list_head(&dn->dn_dbufs)); 1245 ASSERT(dn->dn_datablksz != 0); 1246 ASSERT0(dn->dn_next_bonuslen[txg&TXG_MASK]); 1247 ASSERT0(dn->dn_next_blksz[txg&TXG_MASK]); 1248 ASSERT0(dn->dn_next_bonustype[txg&TXG_MASK]); 1249 1250 dprintf_ds(os->os_dsl_dataset, "obj=%llu txg=%llu\n", 1251 dn->dn_object, txg); 1252 1253 if (dn->dn_free_txg > 0 && dn->dn_free_txg <= txg) { 1254 list_insert_tail(&os->os_free_dnodes[txg&TXG_MASK], dn); 1255 } else { 1256 list_insert_tail(&os->os_dirty_dnodes[txg&TXG_MASK], dn); 1257 } 1258 1259 mutex_exit(&os->os_lock); 1260 1261 /* 1262 * The dnode maintains a hold on its containing dbuf as 1263 * long as there are holds on it. Each instantiated child 1264 * dbuf maintains a hold on the dnode. When the last child 1265 * drops its hold, the dnode will drop its hold on the 1266 * containing dbuf. We add a "dirty hold" here so that the 1267 * dnode will hang around after we finish processing its 1268 * children. 1269 */ 1270 VERIFY(dnode_add_ref(dn, (void *)(uintptr_t)tx->tx_txg)); 1271 1272 (void) dbuf_dirty(dn->dn_dbuf, tx); 1273 1274 dsl_dataset_dirty(os->os_dsl_dataset, tx); 1275 } 1276 1277 void 1278 dnode_free(dnode_t *dn, dmu_tx_t *tx) 1279 { 1280 int txgoff = tx->tx_txg & TXG_MASK; 1281 1282 dprintf("dn=%p txg=%llu\n", dn, tx->tx_txg); 1283 1284 /* we should be the only holder... hopefully */ 1285 /* ASSERT3U(refcount_count(&dn->dn_holds), ==, 1); */ 1286 1287 mutex_enter(&dn->dn_mtx); 1288 if (dn->dn_type == DMU_OT_NONE || dn->dn_free_txg) { 1289 mutex_exit(&dn->dn_mtx); 1290 return; 1291 } 1292 dn->dn_free_txg = tx->tx_txg; 1293 mutex_exit(&dn->dn_mtx); 1294 1295 /* 1296 * If the dnode is already dirty, it needs to be moved from 1297 * the dirty list to the free list. 1298 */ 1299 mutex_enter(&dn->dn_objset->os_lock); 1300 if (list_link_active(&dn->dn_dirty_link[txgoff])) { 1301 list_remove(&dn->dn_objset->os_dirty_dnodes[txgoff], dn); 1302 list_insert_tail(&dn->dn_objset->os_free_dnodes[txgoff], dn); 1303 mutex_exit(&dn->dn_objset->os_lock); 1304 } else { 1305 mutex_exit(&dn->dn_objset->os_lock); 1306 dnode_setdirty(dn, tx); 1307 } 1308 } 1309 1310 /* 1311 * Try to change the block size for the indicated dnode. This can only 1312 * succeed if there are no blocks allocated or dirty beyond first block 1313 */ 1314 int 1315 dnode_set_blksz(dnode_t *dn, uint64_t size, int ibs, dmu_tx_t *tx) 1316 { 1317 dmu_buf_impl_t *db, *db_next; 1318 int err; 1319 1320 if (size == 0) 1321 size = SPA_MINBLOCKSIZE; 1322 if (size > SPA_MAXBLOCKSIZE) 1323 size = SPA_MAXBLOCKSIZE; 1324 else 1325 size = P2ROUNDUP(size, SPA_MINBLOCKSIZE); 1326 1327 if (ibs == dn->dn_indblkshift) 1328 ibs = 0; 1329 1330 if (size >> SPA_MINBLOCKSHIFT == dn->dn_datablkszsec && ibs == 0) 1331 return (0); 1332 1333 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 1334 1335 /* Check for any allocated blocks beyond the first */ 1336 if (dn->dn_phys->dn_maxblkid != 0) 1337 goto fail; 1338 1339 mutex_enter(&dn->dn_dbufs_mtx); 1340 for (db = list_head(&dn->dn_dbufs); db; db = db_next) { 1341 db_next = list_next(&dn->dn_dbufs, db); 1342 1343 if (db->db_blkid != 0 && db->db_blkid != DMU_BONUS_BLKID && 1344 db->db_blkid != DMU_SPILL_BLKID) { 1345 mutex_exit(&dn->dn_dbufs_mtx); 1346 goto fail; 1347 } 1348 } 1349 mutex_exit(&dn->dn_dbufs_mtx); 1350 1351 if (ibs && dn->dn_nlevels != 1) 1352 goto fail; 1353 1354 /* resize the old block */ 1355 err = dbuf_hold_impl(dn, 0, 0, TRUE, FTAG, &db); 1356 if (err == 0) 1357 dbuf_new_size(db, size, tx); 1358 else if (err != ENOENT) 1359 goto fail; 1360 1361 dnode_setdblksz(dn, size); 1362 dnode_setdirty(dn, tx); 1363 dn->dn_next_blksz[tx->tx_txg&TXG_MASK] = size; 1364 if (ibs) { 1365 dn->dn_indblkshift = ibs; 1366 dn->dn_next_indblkshift[tx->tx_txg&TXG_MASK] = ibs; 1367 } 1368 /* rele after we have fixed the blocksize in the dnode */ 1369 if (db) 1370 dbuf_rele(db, FTAG); 1371 1372 rw_exit(&dn->dn_struct_rwlock); 1373 return (0); 1374 1375 fail: 1376 rw_exit(&dn->dn_struct_rwlock); 1377 return (SET_ERROR(ENOTSUP)); 1378 } 1379 1380 /* read-holding callers must not rely on the lock being continuously held */ 1381 void 1382 dnode_new_blkid(dnode_t *dn, uint64_t blkid, dmu_tx_t *tx, boolean_t have_read) 1383 { 1384 uint64_t txgoff = tx->tx_txg & TXG_MASK; 1385 int epbs, new_nlevels; 1386 uint64_t sz; 1387 1388 ASSERT(blkid != DMU_BONUS_BLKID); 1389 1390 ASSERT(have_read ? 1391 RW_READ_HELD(&dn->dn_struct_rwlock) : 1392 RW_WRITE_HELD(&dn->dn_struct_rwlock)); 1393 1394 /* 1395 * if we have a read-lock, check to see if we need to do any work 1396 * before upgrading to a write-lock. 1397 */ 1398 if (have_read) { 1399 if (blkid <= dn->dn_maxblkid) 1400 return; 1401 1402 if (!rw_tryupgrade(&dn->dn_struct_rwlock)) { 1403 rw_exit(&dn->dn_struct_rwlock); 1404 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 1405 } 1406 } 1407 1408 if (blkid <= dn->dn_maxblkid) 1409 goto out; 1410 1411 dn->dn_maxblkid = blkid; 1412 1413 /* 1414 * Compute the number of levels necessary to support the new maxblkid. 1415 */ 1416 new_nlevels = 1; 1417 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT; 1418 for (sz = dn->dn_nblkptr; 1419 sz <= blkid && sz >= dn->dn_nblkptr; sz <<= epbs) 1420 new_nlevels++; 1421 1422 if (new_nlevels > dn->dn_nlevels) { 1423 int old_nlevels = dn->dn_nlevels; 1424 dmu_buf_impl_t *db; 1425 list_t *list; 1426 dbuf_dirty_record_t *new, *dr, *dr_next; 1427 1428 dn->dn_nlevels = new_nlevels; 1429 1430 ASSERT3U(new_nlevels, >, dn->dn_next_nlevels[txgoff]); 1431 dn->dn_next_nlevels[txgoff] = new_nlevels; 1432 1433 /* dirty the left indirects */ 1434 db = dbuf_hold_level(dn, old_nlevels, 0, FTAG); 1435 ASSERT(db != NULL); 1436 new = dbuf_dirty(db, tx); 1437 dbuf_rele(db, FTAG); 1438 1439 /* transfer the dirty records to the new indirect */ 1440 mutex_enter(&dn->dn_mtx); 1441 mutex_enter(&new->dt.di.dr_mtx); 1442 list = &dn->dn_dirty_records[txgoff]; 1443 for (dr = list_head(list); dr; dr = dr_next) { 1444 dr_next = list_next(&dn->dn_dirty_records[txgoff], dr); 1445 if (dr->dr_dbuf->db_level != new_nlevels-1 && 1446 dr->dr_dbuf->db_blkid != DMU_BONUS_BLKID && 1447 dr->dr_dbuf->db_blkid != DMU_SPILL_BLKID) { 1448 ASSERT(dr->dr_dbuf->db_level == old_nlevels-1); 1449 list_remove(&dn->dn_dirty_records[txgoff], dr); 1450 list_insert_tail(&new->dt.di.dr_children, dr); 1451 dr->dr_parent = new; 1452 } 1453 } 1454 mutex_exit(&new->dt.di.dr_mtx); 1455 mutex_exit(&dn->dn_mtx); 1456 } 1457 1458 out: 1459 if (have_read) 1460 rw_downgrade(&dn->dn_struct_rwlock); 1461 } 1462 1463 void 1464 dnode_clear_range(dnode_t *dn, uint64_t blkid, uint64_t nblks, dmu_tx_t *tx) 1465 { 1466 avl_tree_t *tree = &dn->dn_ranges[tx->tx_txg&TXG_MASK]; 1467 avl_index_t where; 1468 free_range_t *rp; 1469 free_range_t rp_tofind; 1470 uint64_t endblk = blkid + nblks; 1471 1472 ASSERT(MUTEX_HELD(&dn->dn_mtx)); 1473 ASSERT(nblks <= UINT64_MAX - blkid); /* no overflow */ 1474 1475 dprintf_dnode(dn, "blkid=%llu nblks=%llu txg=%llu\n", 1476 blkid, nblks, tx->tx_txg); 1477 rp_tofind.fr_blkid = blkid; 1478 rp = avl_find(tree, &rp_tofind, &where); 1479 if (rp == NULL) 1480 rp = avl_nearest(tree, where, AVL_BEFORE); 1481 if (rp == NULL) 1482 rp = avl_nearest(tree, where, AVL_AFTER); 1483 1484 while (rp && (rp->fr_blkid <= blkid + nblks)) { 1485 uint64_t fr_endblk = rp->fr_blkid + rp->fr_nblks; 1486 free_range_t *nrp = AVL_NEXT(tree, rp); 1487 1488 if (blkid <= rp->fr_blkid && endblk >= fr_endblk) { 1489 /* clear this entire range */ 1490 avl_remove(tree, rp); 1491 kmem_free(rp, sizeof (free_range_t)); 1492 } else if (blkid <= rp->fr_blkid && 1493 endblk > rp->fr_blkid && endblk < fr_endblk) { 1494 /* clear the beginning of this range */ 1495 rp->fr_blkid = endblk; 1496 rp->fr_nblks = fr_endblk - endblk; 1497 } else if (blkid > rp->fr_blkid && blkid < fr_endblk && 1498 endblk >= fr_endblk) { 1499 /* clear the end of this range */ 1500 rp->fr_nblks = blkid - rp->fr_blkid; 1501 } else if (blkid > rp->fr_blkid && endblk < fr_endblk) { 1502 /* clear a chunk out of this range */ 1503 free_range_t *new_rp = 1504 kmem_alloc(sizeof (free_range_t), KM_SLEEP); 1505 1506 new_rp->fr_blkid = endblk; 1507 new_rp->fr_nblks = fr_endblk - endblk; 1508 avl_insert_here(tree, new_rp, rp, AVL_AFTER); 1509 rp->fr_nblks = blkid - rp->fr_blkid; 1510 } 1511 /* there may be no overlap */ 1512 rp = nrp; 1513 } 1514 } 1515 1516 void 1517 dnode_free_range(dnode_t *dn, uint64_t off, uint64_t len, dmu_tx_t *tx) 1518 { 1519 dmu_buf_impl_t *db; 1520 uint64_t blkoff, blkid, nblks; 1521 int blksz, blkshift, head, tail; 1522 int trunc = FALSE; 1523 int epbs; 1524 1525 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 1526 blksz = dn->dn_datablksz; 1527 blkshift = dn->dn_datablkshift; 1528 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT; 1529 1530 if (len == -1ULL) { 1531 len = UINT64_MAX - off; 1532 trunc = TRUE; 1533 } 1534 1535 /* 1536 * First, block align the region to free: 1537 */ 1538 if (ISP2(blksz)) { 1539 head = P2NPHASE(off, blksz); 1540 blkoff = P2PHASE(off, blksz); 1541 if ((off >> blkshift) > dn->dn_maxblkid) 1542 goto out; 1543 } else { 1544 ASSERT(dn->dn_maxblkid == 0); 1545 if (off == 0 && len >= blksz) { 1546 /* Freeing the whole block; fast-track this request */ 1547 blkid = 0; 1548 nblks = 1; 1549 goto done; 1550 } else if (off >= blksz) { 1551 /* Freeing past end-of-data */ 1552 goto out; 1553 } else { 1554 /* Freeing part of the block. */ 1555 head = blksz - off; 1556 ASSERT3U(head, >, 0); 1557 } 1558 blkoff = off; 1559 } 1560 /* zero out any partial block data at the start of the range */ 1561 if (head) { 1562 ASSERT3U(blkoff + head, ==, blksz); 1563 if (len < head) 1564 head = len; 1565 if (dbuf_hold_impl(dn, 0, dbuf_whichblock(dn, off), TRUE, 1566 FTAG, &db) == 0) { 1567 caddr_t data; 1568 1569 /* don't dirty if it isn't on disk and isn't dirty */ 1570 if (db->db_last_dirty || 1571 (db->db_blkptr && !BP_IS_HOLE(db->db_blkptr))) { 1572 rw_exit(&dn->dn_struct_rwlock); 1573 dbuf_will_dirty(db, tx); 1574 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 1575 data = db->db.db_data; 1576 bzero(data + blkoff, head); 1577 } 1578 dbuf_rele(db, FTAG); 1579 } 1580 off += head; 1581 len -= head; 1582 } 1583 1584 /* If the range was less than one block, we're done */ 1585 if (len == 0) 1586 goto out; 1587 1588 /* If the remaining range is past end of file, we're done */ 1589 if ((off >> blkshift) > dn->dn_maxblkid) 1590 goto out; 1591 1592 ASSERT(ISP2(blksz)); 1593 if (trunc) 1594 tail = 0; 1595 else 1596 tail = P2PHASE(len, blksz); 1597 1598 ASSERT0(P2PHASE(off, blksz)); 1599 /* zero out any partial block data at the end of the range */ 1600 if (tail) { 1601 if (len < tail) 1602 tail = len; 1603 if (dbuf_hold_impl(dn, 0, dbuf_whichblock(dn, off+len), 1604 TRUE, FTAG, &db) == 0) { 1605 /* don't dirty if not on disk and not dirty */ 1606 if (db->db_last_dirty || 1607 (db->db_blkptr && !BP_IS_HOLE(db->db_blkptr))) { 1608 rw_exit(&dn->dn_struct_rwlock); 1609 dbuf_will_dirty(db, tx); 1610 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 1611 bzero(db->db.db_data, tail); 1612 } 1613 dbuf_rele(db, FTAG); 1614 } 1615 len -= tail; 1616 } 1617 1618 /* If the range did not include a full block, we are done */ 1619 if (len == 0) 1620 goto out; 1621 1622 ASSERT(IS_P2ALIGNED(off, blksz)); 1623 ASSERT(trunc || IS_P2ALIGNED(len, blksz)); 1624 blkid = off >> blkshift; 1625 nblks = len >> blkshift; 1626 if (trunc) 1627 nblks += 1; 1628 1629 /* 1630 * Read in and mark all the level-1 indirects dirty, 1631 * so that they will stay in memory until syncing phase. 1632 * Always dirty the first and last indirect to make sure 1633 * we dirty all the partial indirects. 1634 */ 1635 if (dn->dn_nlevels > 1) { 1636 uint64_t i, first, last; 1637 int shift = epbs + dn->dn_datablkshift; 1638 1639 first = blkid >> epbs; 1640 if (db = dbuf_hold_level(dn, 1, first, FTAG)) { 1641 dbuf_will_dirty(db, tx); 1642 dbuf_rele(db, FTAG); 1643 } 1644 if (trunc) 1645 last = dn->dn_maxblkid >> epbs; 1646 else 1647 last = (blkid + nblks - 1) >> epbs; 1648 if (last > first && (db = dbuf_hold_level(dn, 1, last, FTAG))) { 1649 dbuf_will_dirty(db, tx); 1650 dbuf_rele(db, FTAG); 1651 } 1652 for (i = first + 1; i < last; i++) { 1653 uint64_t ibyte = i << shift; 1654 int err; 1655 1656 err = dnode_next_offset(dn, 1657 DNODE_FIND_HAVELOCK, &ibyte, 1, 1, 0); 1658 i = ibyte >> shift; 1659 if (err == ESRCH || i >= last) 1660 break; 1661 ASSERT(err == 0); 1662 db = dbuf_hold_level(dn, 1, i, FTAG); 1663 if (db) { 1664 dbuf_will_dirty(db, tx); 1665 dbuf_rele(db, FTAG); 1666 } 1667 } 1668 } 1669 done: 1670 /* 1671 * Add this range to the dnode range list. 1672 * We will finish up this free operation in the syncing phase. 1673 */ 1674 mutex_enter(&dn->dn_mtx); 1675 dnode_clear_range(dn, blkid, nblks, tx); 1676 { 1677 free_range_t *rp, *found; 1678 avl_index_t where; 1679 avl_tree_t *tree = &dn->dn_ranges[tx->tx_txg&TXG_MASK]; 1680 1681 /* Add new range to dn_ranges */ 1682 rp = kmem_alloc(sizeof (free_range_t), KM_SLEEP); 1683 rp->fr_blkid = blkid; 1684 rp->fr_nblks = nblks; 1685 found = avl_find(tree, rp, &where); 1686 ASSERT(found == NULL); 1687 avl_insert(tree, rp, where); 1688 dprintf_dnode(dn, "blkid=%llu nblks=%llu txg=%llu\n", 1689 blkid, nblks, tx->tx_txg); 1690 } 1691 mutex_exit(&dn->dn_mtx); 1692 1693 dbuf_free_range(dn, blkid, blkid + nblks - 1, tx); 1694 dnode_setdirty(dn, tx); 1695 out: 1696 if (trunc && dn->dn_maxblkid >= (off >> blkshift)) 1697 dn->dn_maxblkid = (off >> blkshift ? (off >> blkshift) - 1 : 0); 1698 1699 rw_exit(&dn->dn_struct_rwlock); 1700 } 1701 1702 static boolean_t 1703 dnode_spill_freed(dnode_t *dn) 1704 { 1705 int i; 1706 1707 mutex_enter(&dn->dn_mtx); 1708 for (i = 0; i < TXG_SIZE; i++) { 1709 if (dn->dn_rm_spillblk[i] == DN_KILL_SPILLBLK) 1710 break; 1711 } 1712 mutex_exit(&dn->dn_mtx); 1713 return (i < TXG_SIZE); 1714 } 1715 1716 /* return TRUE if this blkid was freed in a recent txg, or FALSE if it wasn't */ 1717 uint64_t 1718 dnode_block_freed(dnode_t *dn, uint64_t blkid) 1719 { 1720 free_range_t range_tofind; 1721 void *dp = spa_get_dsl(dn->dn_objset->os_spa); 1722 int i; 1723 1724 if (blkid == DMU_BONUS_BLKID) 1725 return (FALSE); 1726 1727 /* 1728 * If we're in the process of opening the pool, dp will not be 1729 * set yet, but there shouldn't be anything dirty. 1730 */ 1731 if (dp == NULL) 1732 return (FALSE); 1733 1734 if (dn->dn_free_txg) 1735 return (TRUE); 1736 1737 if (blkid == DMU_SPILL_BLKID) 1738 return (dnode_spill_freed(dn)); 1739 1740 range_tofind.fr_blkid = blkid; 1741 mutex_enter(&dn->dn_mtx); 1742 for (i = 0; i < TXG_SIZE; i++) { 1743 free_range_t *range_found; 1744 avl_index_t idx; 1745 1746 range_found = avl_find(&dn->dn_ranges[i], &range_tofind, &idx); 1747 if (range_found) { 1748 ASSERT(range_found->fr_nblks > 0); 1749 break; 1750 } 1751 range_found = avl_nearest(&dn->dn_ranges[i], idx, AVL_BEFORE); 1752 if (range_found && 1753 range_found->fr_blkid + range_found->fr_nblks > blkid) 1754 break; 1755 } 1756 mutex_exit(&dn->dn_mtx); 1757 return (i < TXG_SIZE); 1758 } 1759 1760 /* call from syncing context when we actually write/free space for this dnode */ 1761 void 1762 dnode_diduse_space(dnode_t *dn, int64_t delta) 1763 { 1764 uint64_t space; 1765 dprintf_dnode(dn, "dn=%p dnp=%p used=%llu delta=%lld\n", 1766 dn, dn->dn_phys, 1767 (u_longlong_t)dn->dn_phys->dn_used, 1768 (longlong_t)delta); 1769 1770 mutex_enter(&dn->dn_mtx); 1771 space = DN_USED_BYTES(dn->dn_phys); 1772 if (delta > 0) { 1773 ASSERT3U(space + delta, >=, space); /* no overflow */ 1774 } else { 1775 ASSERT3U(space, >=, -delta); /* no underflow */ 1776 } 1777 space += delta; 1778 if (spa_version(dn->dn_objset->os_spa) < SPA_VERSION_DNODE_BYTES) { 1779 ASSERT((dn->dn_phys->dn_flags & DNODE_FLAG_USED_BYTES) == 0); 1780 ASSERT0(P2PHASE(space, 1<<DEV_BSHIFT)); 1781 dn->dn_phys->dn_used = space >> DEV_BSHIFT; 1782 } else { 1783 dn->dn_phys->dn_used = space; 1784 dn->dn_phys->dn_flags |= DNODE_FLAG_USED_BYTES; 1785 } 1786 mutex_exit(&dn->dn_mtx); 1787 } 1788 1789 /* 1790 * Call when we think we're going to write/free space in open context. 1791 * Be conservative (ie. OK to write less than this or free more than 1792 * this, but don't write more or free less). 1793 */ 1794 void 1795 dnode_willuse_space(dnode_t *dn, int64_t space, dmu_tx_t *tx) 1796 { 1797 objset_t *os = dn->dn_objset; 1798 dsl_dataset_t *ds = os->os_dsl_dataset; 1799 1800 if (space > 0) 1801 space = spa_get_asize(os->os_spa, space); 1802 1803 if (ds) 1804 dsl_dir_willuse_space(ds->ds_dir, space, tx); 1805 1806 dmu_tx_willuse_space(tx, space); 1807 } 1808 1809 /* 1810 * This function scans a block at the indicated "level" looking for 1811 * a hole or data (depending on 'flags'). If level > 0, then we are 1812 * scanning an indirect block looking at its pointers. If level == 0, 1813 * then we are looking at a block of dnodes. If we don't find what we 1814 * are looking for in the block, we return ESRCH. Otherwise, return 1815 * with *offset pointing to the beginning (if searching forwards) or 1816 * end (if searching backwards) of the range covered by the block 1817 * pointer we matched on (or dnode). 1818 * 1819 * The basic search algorithm used below by dnode_next_offset() is to 1820 * use this function to search up the block tree (widen the search) until 1821 * we find something (i.e., we don't return ESRCH) and then search back 1822 * down the tree (narrow the search) until we reach our original search 1823 * level. 1824 */ 1825 static int 1826 dnode_next_offset_level(dnode_t *dn, int flags, uint64_t *offset, 1827 int lvl, uint64_t blkfill, uint64_t txg) 1828 { 1829 dmu_buf_impl_t *db = NULL; 1830 void *data = NULL; 1831 uint64_t epbs = dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT; 1832 uint64_t epb = 1ULL << epbs; 1833 uint64_t minfill, maxfill; 1834 boolean_t hole; 1835 int i, inc, error, span; 1836 1837 dprintf("probing object %llu offset %llx level %d of %u\n", 1838 dn->dn_object, *offset, lvl, dn->dn_phys->dn_nlevels); 1839 1840 hole = ((flags & DNODE_FIND_HOLE) != 0); 1841 inc = (flags & DNODE_FIND_BACKWARDS) ? -1 : 1; 1842 ASSERT(txg == 0 || !hole); 1843 1844 if (lvl == dn->dn_phys->dn_nlevels) { 1845 error = 0; 1846 epb = dn->dn_phys->dn_nblkptr; 1847 data = dn->dn_phys->dn_blkptr; 1848 } else { 1849 uint64_t blkid = dbuf_whichblock(dn, *offset) >> (epbs * lvl); 1850 error = dbuf_hold_impl(dn, lvl, blkid, TRUE, FTAG, &db); 1851 if (error) { 1852 if (error != ENOENT) 1853 return (error); 1854 if (hole) 1855 return (0); 1856 /* 1857 * This can only happen when we are searching up 1858 * the block tree for data. We don't really need to 1859 * adjust the offset, as we will just end up looking 1860 * at the pointer to this block in its parent, and its 1861 * going to be unallocated, so we will skip over it. 1862 */ 1863 return (SET_ERROR(ESRCH)); 1864 } 1865 error = dbuf_read(db, NULL, DB_RF_CANFAIL | DB_RF_HAVESTRUCT); 1866 if (error) { 1867 dbuf_rele(db, FTAG); 1868 return (error); 1869 } 1870 data = db->db.db_data; 1871 } 1872 1873 if (db && txg && 1874 (db->db_blkptr == NULL || db->db_blkptr->blk_birth <= txg)) { 1875 /* 1876 * This can only happen when we are searching up the tree 1877 * and these conditions mean that we need to keep climbing. 1878 */ 1879 error = SET_ERROR(ESRCH); 1880 } else if (lvl == 0) { 1881 dnode_phys_t *dnp = data; 1882 span = DNODE_SHIFT; 1883 ASSERT(dn->dn_type == DMU_OT_DNODE); 1884 1885 for (i = (*offset >> span) & (blkfill - 1); 1886 i >= 0 && i < blkfill; i += inc) { 1887 if ((dnp[i].dn_type == DMU_OT_NONE) == hole) 1888 break; 1889 *offset += (1ULL << span) * inc; 1890 } 1891 if (i < 0 || i == blkfill) 1892 error = SET_ERROR(ESRCH); 1893 } else { 1894 blkptr_t *bp = data; 1895 uint64_t start = *offset; 1896 span = (lvl - 1) * epbs + dn->dn_datablkshift; 1897 minfill = 0; 1898 maxfill = blkfill << ((lvl - 1) * epbs); 1899 1900 if (hole) 1901 maxfill--; 1902 else 1903 minfill++; 1904 1905 *offset = *offset >> span; 1906 for (i = BF64_GET(*offset, 0, epbs); 1907 i >= 0 && i < epb; i += inc) { 1908 if (bp[i].blk_fill >= minfill && 1909 bp[i].blk_fill <= maxfill && 1910 (hole || bp[i].blk_birth > txg)) 1911 break; 1912 if (inc > 0 || *offset > 0) 1913 *offset += inc; 1914 } 1915 *offset = *offset << span; 1916 if (inc < 0) { 1917 /* traversing backwards; position offset at the end */ 1918 ASSERT3U(*offset, <=, start); 1919 *offset = MIN(*offset + (1ULL << span) - 1, start); 1920 } else if (*offset < start) { 1921 *offset = start; 1922 } 1923 if (i < 0 || i >= epb) 1924 error = SET_ERROR(ESRCH); 1925 } 1926 1927 if (db) 1928 dbuf_rele(db, FTAG); 1929 1930 return (error); 1931 } 1932 1933 /* 1934 * Find the next hole, data, or sparse region at or after *offset. 1935 * The value 'blkfill' tells us how many items we expect to find 1936 * in an L0 data block; this value is 1 for normal objects, 1937 * DNODES_PER_BLOCK for the meta dnode, and some fraction of 1938 * DNODES_PER_BLOCK when searching for sparse regions thereof. 1939 * 1940 * Examples: 1941 * 1942 * dnode_next_offset(dn, flags, offset, 1, 1, 0); 1943 * Finds the next/previous hole/data in a file. 1944 * Used in dmu_offset_next(). 1945 * 1946 * dnode_next_offset(mdn, flags, offset, 0, DNODES_PER_BLOCK, txg); 1947 * Finds the next free/allocated dnode an objset's meta-dnode. 1948 * Only finds objects that have new contents since txg (ie. 1949 * bonus buffer changes and content removal are ignored). 1950 * Used in dmu_object_next(). 1951 * 1952 * dnode_next_offset(mdn, DNODE_FIND_HOLE, offset, 2, DNODES_PER_BLOCK >> 2, 0); 1953 * Finds the next L2 meta-dnode bp that's at most 1/4 full. 1954 * Used in dmu_object_alloc(). 1955 */ 1956 int 1957 dnode_next_offset(dnode_t *dn, int flags, uint64_t *offset, 1958 int minlvl, uint64_t blkfill, uint64_t txg) 1959 { 1960 uint64_t initial_offset = *offset; 1961 int lvl, maxlvl; 1962 int error = 0; 1963 1964 if (!(flags & DNODE_FIND_HAVELOCK)) 1965 rw_enter(&dn->dn_struct_rwlock, RW_READER); 1966 1967 if (dn->dn_phys->dn_nlevels == 0) { 1968 error = SET_ERROR(ESRCH); 1969 goto out; 1970 } 1971 1972 if (dn->dn_datablkshift == 0) { 1973 if (*offset < dn->dn_datablksz) { 1974 if (flags & DNODE_FIND_HOLE) 1975 *offset = dn->dn_datablksz; 1976 } else { 1977 error = SET_ERROR(ESRCH); 1978 } 1979 goto out; 1980 } 1981 1982 maxlvl = dn->dn_phys->dn_nlevels; 1983 1984 for (lvl = minlvl; lvl <= maxlvl; lvl++) { 1985 error = dnode_next_offset_level(dn, 1986 flags, offset, lvl, blkfill, txg); 1987 if (error != ESRCH) 1988 break; 1989 } 1990 1991 while (error == 0 && --lvl >= minlvl) { 1992 error = dnode_next_offset_level(dn, 1993 flags, offset, lvl, blkfill, txg); 1994 } 1995 1996 if (error == 0 && (flags & DNODE_FIND_BACKWARDS ? 1997 initial_offset < *offset : initial_offset > *offset)) 1998 error = SET_ERROR(ESRCH); 1999 out: 2000 if (!(flags & DNODE_FIND_HAVELOCK)) 2001 rw_exit(&dn->dn_struct_rwlock); 2002 2003 return (error); 2004 }