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) 2012 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 refcount_create(&dn->dn_holds); 76 refcount_create(&dn->dn_tx_holds); 77 list_link_init(&dn->dn_link); 78 79 bzero(&dn->dn_next_nblkptr[0], sizeof (dn->dn_next_nblkptr)); 80 bzero(&dn->dn_next_nlevels[0], sizeof (dn->dn_next_nlevels)); 81 bzero(&dn->dn_next_indblkshift[0], sizeof (dn->dn_next_indblkshift)); 82 bzero(&dn->dn_next_bonustype[0], sizeof (dn->dn_next_bonustype)); 83 bzero(&dn->dn_rm_spillblk[0], sizeof (dn->dn_rm_spillblk)); 84 bzero(&dn->dn_next_bonuslen[0], sizeof (dn->dn_next_bonuslen)); 85 bzero(&dn->dn_next_blksz[0], sizeof (dn->dn_next_blksz)); 86 87 for (i = 0; i < TXG_SIZE; i++) { 88 list_link_init(&dn->dn_dirty_link[i]); 89 avl_create(&dn->dn_ranges[i], free_range_compar, 90 sizeof (free_range_t), 91 offsetof(struct free_range, fr_node)); 92 list_create(&dn->dn_dirty_records[i], 93 sizeof (dbuf_dirty_record_t), 94 offsetof(dbuf_dirty_record_t, dr_dirty_node)); 95 } 96 97 dn->dn_allocated_txg = 0; 98 dn->dn_free_txg = 0; 99 dn->dn_assigned_txg = 0; 100 dn->dn_dirtyctx = 0; 101 dn->dn_dirtyctx_firstset = NULL; 102 dn->dn_bonus = NULL; 103 dn->dn_have_spill = B_FALSE; 104 dn->dn_zio = NULL; 105 dn->dn_oldused = 0; 106 dn->dn_oldflags = 0; 107 dn->dn_olduid = 0; 108 dn->dn_oldgid = 0; 109 dn->dn_newuid = 0; 110 dn->dn_newgid = 0; 111 dn->dn_id_flags = 0; 112 113 dn->dn_dbufs_count = 0; 114 list_create(&dn->dn_dbufs, sizeof (dmu_buf_impl_t), 115 offsetof(dmu_buf_impl_t, db_link)); 116 117 dn->dn_moved = 0; 118 return (0); 119 } 120 121 /* ARGSUSED */ 122 static void 123 dnode_dest(void *arg, void *unused) 124 { 125 int i; 126 dnode_t *dn = arg; 127 128 rw_destroy(&dn->dn_struct_rwlock); 129 mutex_destroy(&dn->dn_mtx); 130 mutex_destroy(&dn->dn_dbufs_mtx); 131 cv_destroy(&dn->dn_notxholds); 132 refcount_destroy(&dn->dn_holds); 133 refcount_destroy(&dn->dn_tx_holds); 134 ASSERT(!list_link_active(&dn->dn_link)); 135 136 for (i = 0; i < TXG_SIZE; i++) { 137 ASSERT(!list_link_active(&dn->dn_dirty_link[i])); 138 avl_destroy(&dn->dn_ranges[i]); 139 list_destroy(&dn->dn_dirty_records[i]); 140 ASSERT0(dn->dn_next_nblkptr[i]); 141 ASSERT0(dn->dn_next_nlevels[i]); 142 ASSERT0(dn->dn_next_indblkshift[i]); 143 ASSERT0(dn->dn_next_bonustype[i]); 144 ASSERT0(dn->dn_rm_spillblk[i]); 145 ASSERT0(dn->dn_next_bonuslen[i]); 146 ASSERT0(dn->dn_next_blksz[i]); 147 } 148 149 ASSERT0(dn->dn_allocated_txg); 150 ASSERT0(dn->dn_free_txg); 151 ASSERT0(dn->dn_assigned_txg); 152 ASSERT0(dn->dn_dirtyctx); 153 ASSERT3P(dn->dn_dirtyctx_firstset, ==, NULL); 154 ASSERT3P(dn->dn_bonus, ==, NULL); 155 ASSERT(!dn->dn_have_spill); 156 ASSERT3P(dn->dn_zio, ==, NULL); 157 ASSERT0(dn->dn_oldused); 158 ASSERT0(dn->dn_oldflags); 159 ASSERT0(dn->dn_olduid); 160 ASSERT0(dn->dn_oldgid); 161 ASSERT0(dn->dn_newuid); 162 ASSERT0(dn->dn_newgid); 163 ASSERT0(dn->dn_id_flags); 164 165 ASSERT0(dn->dn_dbufs_count); 166 list_destroy(&dn->dn_dbufs); 167 } 168 169 void 170 dnode_init(void) 171 { 172 ASSERT(dnode_cache == NULL); 173 dnode_cache = kmem_cache_create("dnode_t", 174 sizeof (dnode_t), 175 0, dnode_cons, dnode_dest, NULL, NULL, NULL, 0); 176 kmem_cache_set_move(dnode_cache, dnode_move); 177 } 178 179 void 180 dnode_fini(void) 181 { 182 kmem_cache_destroy(dnode_cache); 183 dnode_cache = NULL; 184 } 185 186 187 #ifdef ZFS_DEBUG 188 void 189 dnode_verify(dnode_t *dn) 190 { 191 int drop_struct_lock = FALSE; 192 193 ASSERT(dn->dn_phys); 194 ASSERT(dn->dn_objset); 195 ASSERT(dn->dn_handle->dnh_dnode == dn); 196 197 ASSERT(DMU_OT_IS_VALID(dn->dn_phys->dn_type)); 198 199 if (!(zfs_flags & ZFS_DEBUG_DNODE_VERIFY)) 200 return; 201 202 if (!RW_WRITE_HELD(&dn->dn_struct_rwlock)) { 203 rw_enter(&dn->dn_struct_rwlock, RW_READER); 204 drop_struct_lock = TRUE; 205 } 206 if (dn->dn_phys->dn_type != DMU_OT_NONE || dn->dn_allocated_txg != 0) { 207 int i; 208 ASSERT3U(dn->dn_indblkshift, >=, 0); 209 ASSERT3U(dn->dn_indblkshift, <=, SPA_MAXBLOCKSHIFT); 210 if (dn->dn_datablkshift) { 211 ASSERT3U(dn->dn_datablkshift, >=, SPA_MINBLOCKSHIFT); 212 ASSERT3U(dn->dn_datablkshift, <=, SPA_MAXBLOCKSHIFT); 213 ASSERT3U(1<<dn->dn_datablkshift, ==, dn->dn_datablksz); 214 } 215 ASSERT3U(dn->dn_nlevels, <=, 30); 216 ASSERT(DMU_OT_IS_VALID(dn->dn_type)); 217 ASSERT3U(dn->dn_nblkptr, >=, 1); 218 ASSERT3U(dn->dn_nblkptr, <=, DN_MAX_NBLKPTR); 219 ASSERT3U(dn->dn_bonuslen, <=, DN_MAX_BONUSLEN); 220 ASSERT3U(dn->dn_datablksz, ==, 221 dn->dn_datablkszsec << SPA_MINBLOCKSHIFT); 222 ASSERT3U(ISP2(dn->dn_datablksz), ==, dn->dn_datablkshift != 0); 223 ASSERT3U((dn->dn_nblkptr - 1) * sizeof (blkptr_t) + 224 dn->dn_bonuslen, <=, DN_MAX_BONUSLEN); 225 for (i = 0; i < TXG_SIZE; i++) { 226 ASSERT3U(dn->dn_next_nlevels[i], <=, dn->dn_nlevels); 227 } 228 } 229 if (dn->dn_phys->dn_type != DMU_OT_NONE) 230 ASSERT3U(dn->dn_phys->dn_nlevels, <=, dn->dn_nlevels); 231 ASSERT(DMU_OBJECT_IS_SPECIAL(dn->dn_object) || dn->dn_dbuf != NULL); 232 if (dn->dn_dbuf != NULL) { 233 ASSERT3P(dn->dn_phys, ==, 234 (dnode_phys_t *)dn->dn_dbuf->db.db_data + 235 (dn->dn_object % (dn->dn_dbuf->db.db_size >> DNODE_SHIFT))); 236 } 237 if (drop_struct_lock) 238 rw_exit(&dn->dn_struct_rwlock); 239 } 240 #endif 241 242 void 243 dnode_byteswap(dnode_phys_t *dnp) 244 { 245 uint64_t *buf64 = (void*)&dnp->dn_blkptr; 246 int i; 247 248 if (dnp->dn_type == DMU_OT_NONE) { 249 bzero(dnp, sizeof (dnode_phys_t)); 250 return; 251 } 252 253 dnp->dn_datablkszsec = BSWAP_16(dnp->dn_datablkszsec); 254 dnp->dn_bonuslen = BSWAP_16(dnp->dn_bonuslen); 255 dnp->dn_maxblkid = BSWAP_64(dnp->dn_maxblkid); 256 dnp->dn_used = BSWAP_64(dnp->dn_used); 257 258 /* 259 * dn_nblkptr is only one byte, so it's OK to read it in either 260 * byte order. We can't read dn_bouslen. 261 */ 262 ASSERT(dnp->dn_indblkshift <= SPA_MAXBLOCKSHIFT); 263 ASSERT(dnp->dn_nblkptr <= DN_MAX_NBLKPTR); 264 for (i = 0; i < dnp->dn_nblkptr * sizeof (blkptr_t)/8; i++) 265 buf64[i] = BSWAP_64(buf64[i]); 266 267 /* 268 * OK to check dn_bonuslen for zero, because it won't matter if 269 * we have the wrong byte order. This is necessary because the 270 * dnode dnode is smaller than a regular dnode. 271 */ 272 if (dnp->dn_bonuslen != 0) { 273 /* 274 * Note that the bonus length calculated here may be 275 * longer than the actual bonus buffer. This is because 276 * we always put the bonus buffer after the last block 277 * pointer (instead of packing it against the end of the 278 * dnode buffer). 279 */ 280 int off = (dnp->dn_nblkptr-1) * sizeof (blkptr_t); 281 size_t len = DN_MAX_BONUSLEN - off; 282 ASSERT(DMU_OT_IS_VALID(dnp->dn_bonustype)); 283 dmu_object_byteswap_t byteswap = 284 DMU_OT_BYTESWAP(dnp->dn_bonustype); 285 dmu_ot_byteswap[byteswap].ob_func(dnp->dn_bonus + off, len); 286 } 287 288 /* Swap SPILL block if we have one */ 289 if (dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) 290 byteswap_uint64_array(&dnp->dn_spill, sizeof (blkptr_t)); 291 292 } 293 294 void 295 dnode_buf_byteswap(void *vbuf, size_t size) 296 { 297 dnode_phys_t *buf = vbuf; 298 int i; 299 300 ASSERT3U(sizeof (dnode_phys_t), ==, (1<<DNODE_SHIFT)); 301 ASSERT((size & (sizeof (dnode_phys_t)-1)) == 0); 302 303 size >>= DNODE_SHIFT; 304 for (i = 0; i < size; i++) { 305 dnode_byteswap(buf); 306 buf++; 307 } 308 } 309 310 static int 311 free_range_compar(const void *node1, const void *node2) 312 { 313 const free_range_t *rp1 = node1; 314 const free_range_t *rp2 = node2; 315 316 if (rp1->fr_blkid < rp2->fr_blkid) 317 return (-1); 318 else if (rp1->fr_blkid > rp2->fr_blkid) 319 return (1); 320 else return (0); 321 } 322 323 void 324 dnode_setbonuslen(dnode_t *dn, int newsize, dmu_tx_t *tx) 325 { 326 ASSERT3U(refcount_count(&dn->dn_holds), >=, 1); 327 328 dnode_setdirty(dn, tx); 329 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 330 ASSERT3U(newsize, <=, DN_MAX_BONUSLEN - 331 (dn->dn_nblkptr-1) * sizeof (blkptr_t)); 332 dn->dn_bonuslen = newsize; 333 if (newsize == 0) 334 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = DN_ZERO_BONUSLEN; 335 else 336 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = dn->dn_bonuslen; 337 rw_exit(&dn->dn_struct_rwlock); 338 } 339 340 void 341 dnode_setbonus_type(dnode_t *dn, dmu_object_type_t newtype, dmu_tx_t *tx) 342 { 343 ASSERT3U(refcount_count(&dn->dn_holds), >=, 1); 344 dnode_setdirty(dn, tx); 345 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 346 dn->dn_bonustype = newtype; 347 dn->dn_next_bonustype[tx->tx_txg & TXG_MASK] = dn->dn_bonustype; 348 rw_exit(&dn->dn_struct_rwlock); 349 } 350 351 void 352 dnode_rm_spill(dnode_t *dn, dmu_tx_t *tx) 353 { 354 ASSERT3U(refcount_count(&dn->dn_holds), >=, 1); 355 ASSERT(RW_WRITE_HELD(&dn->dn_struct_rwlock)); 356 dnode_setdirty(dn, tx); 357 dn->dn_rm_spillblk[tx->tx_txg&TXG_MASK] = DN_KILL_SPILLBLK; 358 dn->dn_have_spill = B_FALSE; 359 } 360 361 static void 362 dnode_setdblksz(dnode_t *dn, int size) 363 { 364 ASSERT0(P2PHASE(size, SPA_MINBLOCKSIZE)); 365 ASSERT3U(size, <=, SPA_MAXBLOCKSIZE); 366 ASSERT3U(size, >=, SPA_MINBLOCKSIZE); 367 ASSERT3U(size >> SPA_MINBLOCKSHIFT, <, 368 1<<(sizeof (dn->dn_phys->dn_datablkszsec) * 8)); 369 dn->dn_datablksz = size; 370 dn->dn_datablkszsec = size >> SPA_MINBLOCKSHIFT; 371 dn->dn_datablkshift = ISP2(size) ? highbit(size - 1) : 0; 372 } 373 374 static dnode_t * 375 dnode_create(objset_t *os, dnode_phys_t *dnp, dmu_buf_impl_t *db, 376 uint64_t object, dnode_handle_t *dnh) 377 { 378 dnode_t *dn = kmem_cache_alloc(dnode_cache, KM_SLEEP); 379 380 ASSERT(!POINTER_IS_VALID(dn->dn_objset)); 381 dn->dn_moved = 0; 382 383 /* 384 * Defer setting dn_objset until the dnode is ready to be a candidate 385 * for the dnode_move() callback. 386 */ 387 dn->dn_object = object; 388 dn->dn_dbuf = db; 389 dn->dn_handle = dnh; 390 dn->dn_phys = dnp; 391 392 if (dnp->dn_datablkszsec) { 393 dnode_setdblksz(dn, dnp->dn_datablkszsec << SPA_MINBLOCKSHIFT); 394 } else { 395 dn->dn_datablksz = 0; 396 dn->dn_datablkszsec = 0; 397 dn->dn_datablkshift = 0; 398 } 399 dn->dn_indblkshift = dnp->dn_indblkshift; 400 dn->dn_nlevels = dnp->dn_nlevels; 401 dn->dn_type = dnp->dn_type; 402 dn->dn_nblkptr = dnp->dn_nblkptr; 403 dn->dn_checksum = dnp->dn_checksum; 404 dn->dn_compress = dnp->dn_compress; 405 dn->dn_bonustype = dnp->dn_bonustype; 406 dn->dn_bonuslen = dnp->dn_bonuslen; 407 dn->dn_maxblkid = dnp->dn_maxblkid; 408 dn->dn_have_spill = ((dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) != 0); 409 dn->dn_id_flags = 0; 410 411 dmu_zfetch_init(&dn->dn_zfetch, dn); 412 413 ASSERT(DMU_OT_IS_VALID(dn->dn_phys->dn_type)); 414 415 mutex_enter(&os->os_lock); 416 list_insert_head(&os->os_dnodes, dn); 417 membar_producer(); 418 /* 419 * Everything else must be valid before assigning dn_objset makes the 420 * dnode eligible for dnode_move(). 421 */ 422 dn->dn_objset = os; 423 mutex_exit(&os->os_lock); 424 425 arc_space_consume(sizeof (dnode_t), ARC_SPACE_OTHER); 426 return (dn); 427 } 428 429 /* 430 * Caller must be holding the dnode handle, which is released upon return. 431 */ 432 static void 433 dnode_destroy(dnode_t *dn) 434 { 435 objset_t *os = dn->dn_objset; 436 437 ASSERT((dn->dn_id_flags & DN_ID_NEW_EXIST) == 0); 438 439 mutex_enter(&os->os_lock); 440 POINTER_INVALIDATE(&dn->dn_objset); 441 list_remove(&os->os_dnodes, dn); 442 mutex_exit(&os->os_lock); 443 444 /* the dnode can no longer move, so we can release the handle */ 445 zrl_remove(&dn->dn_handle->dnh_zrlock); 446 447 dn->dn_allocated_txg = 0; 448 dn->dn_free_txg = 0; 449 dn->dn_assigned_txg = 0; 450 451 dn->dn_dirtyctx = 0; 452 if (dn->dn_dirtyctx_firstset != NULL) { 453 kmem_free(dn->dn_dirtyctx_firstset, 1); 454 dn->dn_dirtyctx_firstset = NULL; 455 } 456 if (dn->dn_bonus != NULL) { 457 mutex_enter(&dn->dn_bonus->db_mtx); 458 dbuf_evict(dn->dn_bonus); 459 dn->dn_bonus = NULL; 460 } 461 dn->dn_zio = NULL; 462 463 dn->dn_have_spill = B_FALSE; 464 dn->dn_oldused = 0; 465 dn->dn_oldflags = 0; 466 dn->dn_olduid = 0; 467 dn->dn_oldgid = 0; 468 dn->dn_newuid = 0; 469 dn->dn_newgid = 0; 470 dn->dn_id_flags = 0; 471 472 dmu_zfetch_rele(&dn->dn_zfetch); 473 kmem_cache_free(dnode_cache, dn); 474 arc_space_return(sizeof (dnode_t), ARC_SPACE_OTHER); 475 } 476 477 void 478 dnode_allocate(dnode_t *dn, dmu_object_type_t ot, int blocksize, int ibs, 479 dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx) 480 { 481 int i; 482 483 if (blocksize == 0) 484 blocksize = 1 << zfs_default_bs; 485 else if (blocksize > SPA_MAXBLOCKSIZE) 486 blocksize = SPA_MAXBLOCKSIZE; 487 else 488 blocksize = P2ROUNDUP(blocksize, SPA_MINBLOCKSIZE); 489 490 if (ibs == 0) 491 ibs = zfs_default_ibs; 492 493 ibs = MIN(MAX(ibs, DN_MIN_INDBLKSHIFT), DN_MAX_INDBLKSHIFT); 494 495 dprintf("os=%p obj=%llu txg=%llu blocksize=%d ibs=%d\n", dn->dn_objset, 496 dn->dn_object, tx->tx_txg, blocksize, ibs); 497 498 ASSERT(dn->dn_type == DMU_OT_NONE); 499 ASSERT(bcmp(dn->dn_phys, &dnode_phys_zero, sizeof (dnode_phys_t)) == 0); 500 ASSERT(dn->dn_phys->dn_type == DMU_OT_NONE); 501 ASSERT(ot != DMU_OT_NONE); 502 ASSERT(DMU_OT_IS_VALID(ot)); 503 ASSERT((bonustype == DMU_OT_NONE && bonuslen == 0) || 504 (bonustype == DMU_OT_SA && bonuslen == 0) || 505 (bonustype != DMU_OT_NONE && bonuslen != 0)); 506 ASSERT(DMU_OT_IS_VALID(bonustype)); 507 ASSERT3U(bonuslen, <=, DN_MAX_BONUSLEN); 508 ASSERT(dn->dn_type == DMU_OT_NONE); 509 ASSERT0(dn->dn_maxblkid); 510 ASSERT0(dn->dn_allocated_txg); 511 ASSERT0(dn->dn_assigned_txg); 512 ASSERT(refcount_is_zero(&dn->dn_tx_holds)); 513 ASSERT3U(refcount_count(&dn->dn_holds), <=, 1); 514 ASSERT3P(list_head(&dn->dn_dbufs), ==, NULL); 515 516 for (i = 0; i < TXG_SIZE; i++) { 517 ASSERT0(dn->dn_next_nblkptr[i]); 518 ASSERT0(dn->dn_next_nlevels[i]); 519 ASSERT0(dn->dn_next_indblkshift[i]); 520 ASSERT0(dn->dn_next_bonuslen[i]); 521 ASSERT0(dn->dn_next_bonustype[i]); 522 ASSERT0(dn->dn_rm_spillblk[i]); 523 ASSERT0(dn->dn_next_blksz[i]); 524 ASSERT(!list_link_active(&dn->dn_dirty_link[i])); 525 ASSERT3P(list_head(&dn->dn_dirty_records[i]), ==, NULL); 526 ASSERT0(avl_numnodes(&dn->dn_ranges[i])); 527 } 528 529 dn->dn_type = ot; 530 dnode_setdblksz(dn, blocksize); 531 dn->dn_indblkshift = ibs; 532 dn->dn_nlevels = 1; 533 if (bonustype == DMU_OT_SA) /* Maximize bonus space for SA */ 534 dn->dn_nblkptr = 1; 535 else 536 dn->dn_nblkptr = 1 + 537 ((DN_MAX_BONUSLEN - bonuslen) >> SPA_BLKPTRSHIFT); 538 dn->dn_bonustype = bonustype; 539 dn->dn_bonuslen = bonuslen; 540 dn->dn_checksum = ZIO_CHECKSUM_INHERIT; 541 dn->dn_compress = ZIO_COMPRESS_INHERIT; 542 dn->dn_dirtyctx = 0; 543 544 dn->dn_free_txg = 0; 545 if (dn->dn_dirtyctx_firstset) { 546 kmem_free(dn->dn_dirtyctx_firstset, 1); 547 dn->dn_dirtyctx_firstset = NULL; 548 } 549 550 dn->dn_allocated_txg = tx->tx_txg; 551 dn->dn_id_flags = 0; 552 553 dnode_setdirty(dn, tx); 554 dn->dn_next_indblkshift[tx->tx_txg & TXG_MASK] = ibs; 555 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = dn->dn_bonuslen; 556 dn->dn_next_bonustype[tx->tx_txg & TXG_MASK] = dn->dn_bonustype; 557 dn->dn_next_blksz[tx->tx_txg & TXG_MASK] = dn->dn_datablksz; 558 } 559 560 void 561 dnode_reallocate(dnode_t *dn, dmu_object_type_t ot, int blocksize, 562 dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx) 563 { 564 int nblkptr; 565 566 ASSERT3U(blocksize, >=, SPA_MINBLOCKSIZE); 567 ASSERT3U(blocksize, <=, SPA_MAXBLOCKSIZE); 568 ASSERT0(blocksize % SPA_MINBLOCKSIZE); 569 ASSERT(dn->dn_object != DMU_META_DNODE_OBJECT || dmu_tx_private_ok(tx)); 570 ASSERT(tx->tx_txg != 0); 571 ASSERT((bonustype == DMU_OT_NONE && bonuslen == 0) || 572 (bonustype != DMU_OT_NONE && bonuslen != 0) || 573 (bonustype == DMU_OT_SA && bonuslen == 0)); 574 ASSERT(DMU_OT_IS_VALID(bonustype)); 575 ASSERT3U(bonuslen, <=, DN_MAX_BONUSLEN); 576 577 /* clean up any unreferenced dbufs */ 578 dnode_evict_dbufs(dn); 579 580 dn->dn_id_flags = 0; 581 582 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 583 dnode_setdirty(dn, tx); 584 if (dn->dn_datablksz != blocksize) { 585 /* change blocksize */ 586 ASSERT(dn->dn_maxblkid == 0 && 587 (BP_IS_HOLE(&dn->dn_phys->dn_blkptr[0]) || 588 dnode_block_freed(dn, 0))); 589 dnode_setdblksz(dn, blocksize); 590 dn->dn_next_blksz[tx->tx_txg&TXG_MASK] = blocksize; 591 } 592 if (dn->dn_bonuslen != bonuslen) 593 dn->dn_next_bonuslen[tx->tx_txg&TXG_MASK] = bonuslen; 594 595 if (bonustype == DMU_OT_SA) /* Maximize bonus space for SA */ 596 nblkptr = 1; 597 else 598 nblkptr = 1 + ((DN_MAX_BONUSLEN - bonuslen) >> SPA_BLKPTRSHIFT); 599 if (dn->dn_bonustype != bonustype) 600 dn->dn_next_bonustype[tx->tx_txg&TXG_MASK] = bonustype; 601 if (dn->dn_nblkptr != nblkptr) 602 dn->dn_next_nblkptr[tx->tx_txg&TXG_MASK] = nblkptr; 603 if (dn->dn_phys->dn_flags & DNODE_FLAG_SPILL_BLKPTR) { 604 dbuf_rm_spill(dn, tx); 605 dnode_rm_spill(dn, tx); 606 } 607 rw_exit(&dn->dn_struct_rwlock); 608 609 /* change type */ 610 dn->dn_type = ot; 611 612 /* change bonus size and type */ 613 mutex_enter(&dn->dn_mtx); 614 dn->dn_bonustype = bonustype; 615 dn->dn_bonuslen = bonuslen; 616 dn->dn_nblkptr = nblkptr; 617 dn->dn_checksum = ZIO_CHECKSUM_INHERIT; 618 dn->dn_compress = ZIO_COMPRESS_INHERIT; 619 ASSERT3U(dn->dn_nblkptr, <=, DN_MAX_NBLKPTR); 620 621 /* fix up the bonus db_size */ 622 if (dn->dn_bonus) { 623 dn->dn_bonus->db.db_size = 624 DN_MAX_BONUSLEN - (dn->dn_nblkptr-1) * sizeof (blkptr_t); 625 ASSERT(dn->dn_bonuslen <= dn->dn_bonus->db.db_size); 626 } 627 628 dn->dn_allocated_txg = tx->tx_txg; 629 mutex_exit(&dn->dn_mtx); 630 } 631 632 #ifdef DNODE_STATS 633 static struct { 634 uint64_t dms_dnode_invalid; 635 uint64_t dms_dnode_recheck1; 636 uint64_t dms_dnode_recheck2; 637 uint64_t dms_dnode_special; 638 uint64_t dms_dnode_handle; 639 uint64_t dms_dnode_rwlock; 640 uint64_t dms_dnode_active; 641 } dnode_move_stats; 642 #endif /* DNODE_STATS */ 643 644 static void 645 dnode_move_impl(dnode_t *odn, dnode_t *ndn) 646 { 647 int i; 648 649 ASSERT(!RW_LOCK_HELD(&odn->dn_struct_rwlock)); 650 ASSERT(MUTEX_NOT_HELD(&odn->dn_mtx)); 651 ASSERT(MUTEX_NOT_HELD(&odn->dn_dbufs_mtx)); 652 ASSERT(!RW_LOCK_HELD(&odn->dn_zfetch.zf_rwlock)); 653 654 /* Copy fields. */ 655 ndn->dn_objset = odn->dn_objset; 656 ndn->dn_object = odn->dn_object; 657 ndn->dn_dbuf = odn->dn_dbuf; 658 ndn->dn_handle = odn->dn_handle; 659 ndn->dn_phys = odn->dn_phys; 660 ndn->dn_type = odn->dn_type; 661 ndn->dn_bonuslen = odn->dn_bonuslen; 662 ndn->dn_bonustype = odn->dn_bonustype; 663 ndn->dn_nblkptr = odn->dn_nblkptr; 664 ndn->dn_checksum = odn->dn_checksum; 665 ndn->dn_compress = odn->dn_compress; 666 ndn->dn_nlevels = odn->dn_nlevels; 667 ndn->dn_indblkshift = odn->dn_indblkshift; 668 ndn->dn_datablkshift = odn->dn_datablkshift; 669 ndn->dn_datablkszsec = odn->dn_datablkszsec; 670 ndn->dn_datablksz = odn->dn_datablksz; 671 ndn->dn_maxblkid = odn->dn_maxblkid; 672 bcopy(&odn->dn_next_nblkptr[0], &ndn->dn_next_nblkptr[0], 673 sizeof (odn->dn_next_nblkptr)); 674 bcopy(&odn->dn_next_nlevels[0], &ndn->dn_next_nlevels[0], 675 sizeof (odn->dn_next_nlevels)); 676 bcopy(&odn->dn_next_indblkshift[0], &ndn->dn_next_indblkshift[0], 677 sizeof (odn->dn_next_indblkshift)); 678 bcopy(&odn->dn_next_bonustype[0], &ndn->dn_next_bonustype[0], 679 sizeof (odn->dn_next_bonustype)); 680 bcopy(&odn->dn_rm_spillblk[0], &ndn->dn_rm_spillblk[0], 681 sizeof (odn->dn_rm_spillblk)); 682 bcopy(&odn->dn_next_bonuslen[0], &ndn->dn_next_bonuslen[0], 683 sizeof (odn->dn_next_bonuslen)); 684 bcopy(&odn->dn_next_blksz[0], &ndn->dn_next_blksz[0], 685 sizeof (odn->dn_next_blksz)); 686 for (i = 0; i < TXG_SIZE; i++) { 687 list_move_tail(&ndn->dn_dirty_records[i], 688 &odn->dn_dirty_records[i]); 689 } 690 bcopy(&odn->dn_ranges[0], &ndn->dn_ranges[0], sizeof (odn->dn_ranges)); 691 ndn->dn_allocated_txg = odn->dn_allocated_txg; 692 ndn->dn_free_txg = odn->dn_free_txg; 693 ndn->dn_assigned_txg = odn->dn_assigned_txg; 694 ndn->dn_dirtyctx = odn->dn_dirtyctx; 695 ndn->dn_dirtyctx_firstset = odn->dn_dirtyctx_firstset; 696 ASSERT(refcount_count(&odn->dn_tx_holds) == 0); 697 refcount_transfer(&ndn->dn_holds, &odn->dn_holds); 698 ASSERT(list_is_empty(&ndn->dn_dbufs)); 699 list_move_tail(&ndn->dn_dbufs, &odn->dn_dbufs); 700 ndn->dn_dbufs_count = odn->dn_dbufs_count; 701 ndn->dn_bonus = odn->dn_bonus; 702 ndn->dn_have_spill = odn->dn_have_spill; 703 ndn->dn_zio = odn->dn_zio; 704 ndn->dn_oldused = odn->dn_oldused; 705 ndn->dn_oldflags = odn->dn_oldflags; 706 ndn->dn_olduid = odn->dn_olduid; 707 ndn->dn_oldgid = odn->dn_oldgid; 708 ndn->dn_newuid = odn->dn_newuid; 709 ndn->dn_newgid = odn->dn_newgid; 710 ndn->dn_id_flags = odn->dn_id_flags; 711 dmu_zfetch_init(&ndn->dn_zfetch, NULL); 712 list_move_tail(&ndn->dn_zfetch.zf_stream, &odn->dn_zfetch.zf_stream); 713 ndn->dn_zfetch.zf_dnode = odn->dn_zfetch.zf_dnode; 714 ndn->dn_zfetch.zf_stream_cnt = odn->dn_zfetch.zf_stream_cnt; 715 ndn->dn_zfetch.zf_alloc_fail = odn->dn_zfetch.zf_alloc_fail; 716 717 /* 718 * Update back pointers. Updating the handle fixes the back pointer of 719 * every descendant dbuf as well as the bonus dbuf. 720 */ 721 ASSERT(ndn->dn_handle->dnh_dnode == odn); 722 ndn->dn_handle->dnh_dnode = ndn; 723 if (ndn->dn_zfetch.zf_dnode == odn) { 724 ndn->dn_zfetch.zf_dnode = ndn; 725 } 726 727 /* 728 * Invalidate the original dnode by clearing all of its back pointers. 729 */ 730 odn->dn_dbuf = NULL; 731 odn->dn_handle = NULL; 732 list_create(&odn->dn_dbufs, sizeof (dmu_buf_impl_t), 733 offsetof(dmu_buf_impl_t, db_link)); 734 odn->dn_dbufs_count = 0; 735 odn->dn_bonus = NULL; 736 odn->dn_zfetch.zf_dnode = NULL; 737 738 /* 739 * Set the low bit of the objset pointer to ensure that dnode_move() 740 * recognizes the dnode as invalid in any subsequent callback. 741 */ 742 POINTER_INVALIDATE(&odn->dn_objset); 743 744 /* 745 * Satisfy the destructor. 746 */ 747 for (i = 0; i < TXG_SIZE; i++) { 748 list_create(&odn->dn_dirty_records[i], 749 sizeof (dbuf_dirty_record_t), 750 offsetof(dbuf_dirty_record_t, dr_dirty_node)); 751 odn->dn_ranges[i].avl_root = NULL; 752 odn->dn_ranges[i].avl_numnodes = 0; 753 odn->dn_next_nlevels[i] = 0; 754 odn->dn_next_indblkshift[i] = 0; 755 odn->dn_next_bonustype[i] = 0; 756 odn->dn_rm_spillblk[i] = 0; 757 odn->dn_next_bonuslen[i] = 0; 758 odn->dn_next_blksz[i] = 0; 759 } 760 odn->dn_allocated_txg = 0; 761 odn->dn_free_txg = 0; 762 odn->dn_assigned_txg = 0; 763 odn->dn_dirtyctx = 0; 764 odn->dn_dirtyctx_firstset = NULL; 765 odn->dn_have_spill = B_FALSE; 766 odn->dn_zio = NULL; 767 odn->dn_oldused = 0; 768 odn->dn_oldflags = 0; 769 odn->dn_olduid = 0; 770 odn->dn_oldgid = 0; 771 odn->dn_newuid = 0; 772 odn->dn_newgid = 0; 773 odn->dn_id_flags = 0; 774 775 /* 776 * Mark the dnode. 777 */ 778 ndn->dn_moved = 1; 779 odn->dn_moved = (uint8_t)-1; 780 } 781 782 #ifdef _KERNEL 783 /*ARGSUSED*/ 784 static kmem_cbrc_t 785 dnode_move(void *buf, void *newbuf, size_t size, void *arg) 786 { 787 dnode_t *odn = buf, *ndn = newbuf; 788 objset_t *os; 789 int64_t refcount; 790 uint32_t dbufs; 791 792 /* 793 * The dnode is on the objset's list of known dnodes if the objset 794 * pointer is valid. We set the low bit of the objset pointer when 795 * freeing the dnode to invalidate it, and the memory patterns written 796 * by kmem (baddcafe and deadbeef) set at least one of the two low bits. 797 * A newly created dnode sets the objset pointer last of all to indicate 798 * that the dnode is known and in a valid state to be moved by this 799 * function. 800 */ 801 os = odn->dn_objset; 802 if (!POINTER_IS_VALID(os)) { 803 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_invalid); 804 return (KMEM_CBRC_DONT_KNOW); 805 } 806 807 /* 808 * Ensure that the objset does not go away during the move. 809 */ 810 rw_enter(&os_lock, RW_WRITER); 811 if (os != odn->dn_objset) { 812 rw_exit(&os_lock); 813 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_recheck1); 814 return (KMEM_CBRC_DONT_KNOW); 815 } 816 817 /* 818 * If the dnode is still valid, then so is the objset. We know that no 819 * valid objset can be freed while we hold os_lock, so we can safely 820 * ensure that the objset remains in use. 821 */ 822 mutex_enter(&os->os_lock); 823 824 /* 825 * Recheck the objset pointer in case the dnode was removed just before 826 * acquiring the lock. 827 */ 828 if (os != odn->dn_objset) { 829 mutex_exit(&os->os_lock); 830 rw_exit(&os_lock); 831 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_recheck2); 832 return (KMEM_CBRC_DONT_KNOW); 833 } 834 835 /* 836 * At this point we know that as long as we hold os->os_lock, the dnode 837 * cannot be freed and fields within the dnode can be safely accessed. 838 * The objset listing this dnode cannot go away as long as this dnode is 839 * on its list. 840 */ 841 rw_exit(&os_lock); 842 if (DMU_OBJECT_IS_SPECIAL(odn->dn_object)) { 843 mutex_exit(&os->os_lock); 844 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_special); 845 return (KMEM_CBRC_NO); 846 } 847 ASSERT(odn->dn_dbuf != NULL); /* only "special" dnodes have no parent */ 848 849 /* 850 * Lock the dnode handle to prevent the dnode from obtaining any new 851 * holds. This also prevents the descendant dbufs and the bonus dbuf 852 * from accessing the dnode, so that we can discount their holds. The 853 * handle is safe to access because we know that while the dnode cannot 854 * go away, neither can its handle. Once we hold dnh_zrlock, we can 855 * safely move any dnode referenced only by dbufs. 856 */ 857 if (!zrl_tryenter(&odn->dn_handle->dnh_zrlock)) { 858 mutex_exit(&os->os_lock); 859 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_handle); 860 return (KMEM_CBRC_LATER); 861 } 862 863 /* 864 * Ensure a consistent view of the dnode's holds and the dnode's dbufs. 865 * We need to guarantee that there is a hold for every dbuf in order to 866 * determine whether the dnode is actively referenced. Falsely matching 867 * a dbuf to an active hold would lead to an unsafe move. It's possible 868 * that a thread already having an active dnode hold is about to add a 869 * dbuf, and we can't compare hold and dbuf counts while the add is in 870 * progress. 871 */ 872 if (!rw_tryenter(&odn->dn_struct_rwlock, RW_WRITER)) { 873 zrl_exit(&odn->dn_handle->dnh_zrlock); 874 mutex_exit(&os->os_lock); 875 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_rwlock); 876 return (KMEM_CBRC_LATER); 877 } 878 879 /* 880 * A dbuf may be removed (evicted) without an active dnode hold. In that 881 * case, the dbuf count is decremented under the handle lock before the 882 * dbuf's hold is released. This order ensures that if we count the hold 883 * after the dbuf is removed but before its hold is released, we will 884 * treat the unmatched hold as active and exit safely. If we count the 885 * hold before the dbuf is removed, the hold is discounted, and the 886 * removal is blocked until the move completes. 887 */ 888 refcount = refcount_count(&odn->dn_holds); 889 ASSERT(refcount >= 0); 890 dbufs = odn->dn_dbufs_count; 891 892 /* We can't have more dbufs than dnode holds. */ 893 ASSERT3U(dbufs, <=, refcount); 894 DTRACE_PROBE3(dnode__move, dnode_t *, odn, int64_t, refcount, 895 uint32_t, dbufs); 896 897 if (refcount > dbufs) { 898 rw_exit(&odn->dn_struct_rwlock); 899 zrl_exit(&odn->dn_handle->dnh_zrlock); 900 mutex_exit(&os->os_lock); 901 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_active); 902 return (KMEM_CBRC_LATER); 903 } 904 905 rw_exit(&odn->dn_struct_rwlock); 906 907 /* 908 * At this point we know that anyone with a hold on the dnode is not 909 * actively referencing it. The dnode is known and in a valid state to 910 * move. We're holding the locks needed to execute the critical section. 911 */ 912 dnode_move_impl(odn, ndn); 913 914 list_link_replace(&odn->dn_link, &ndn->dn_link); 915 /* If the dnode was safe to move, the refcount cannot have changed. */ 916 ASSERT(refcount == refcount_count(&ndn->dn_holds)); 917 ASSERT(dbufs == ndn->dn_dbufs_count); 918 zrl_exit(&ndn->dn_handle->dnh_zrlock); /* handle has moved */ 919 mutex_exit(&os->os_lock); 920 921 return (KMEM_CBRC_YES); 922 } 923 #endif /* _KERNEL */ 924 925 void 926 dnode_special_close(dnode_handle_t *dnh) 927 { 928 dnode_t *dn = dnh->dnh_dnode; 929 930 /* 931 * Wait for final references to the dnode to clear. This can 932 * only happen if the arc is asyncronously evicting state that 933 * has a hold on this dnode while we are trying to evict this 934 * dnode. 935 */ 936 while (refcount_count(&dn->dn_holds) > 0) 937 delay(1); 938 zrl_add(&dnh->dnh_zrlock); 939 dnode_destroy(dn); /* implicit zrl_remove() */ 940 zrl_destroy(&dnh->dnh_zrlock); 941 dnh->dnh_dnode = NULL; 942 } 943 944 dnode_t * 945 dnode_special_open(objset_t *os, dnode_phys_t *dnp, uint64_t object, 946 dnode_handle_t *dnh) 947 { 948 dnode_t *dn = dnode_create(os, dnp, NULL, object, dnh); 949 dnh->dnh_dnode = dn; 950 zrl_init(&dnh->dnh_zrlock); 951 DNODE_VERIFY(dn); 952 return (dn); 953 } 954 955 static void 956 dnode_buf_pageout(dmu_buf_t *db, void *arg) 957 { 958 dnode_children_t *children_dnodes = arg; 959 int i; 960 int epb = db->db_size >> DNODE_SHIFT; 961 962 ASSERT(epb == children_dnodes->dnc_count); 963 964 for (i = 0; i < epb; i++) { 965 dnode_handle_t *dnh = &children_dnodes->dnc_children[i]; 966 dnode_t *dn; 967 968 /* 969 * The dnode handle lock guards against the dnode moving to 970 * another valid address, so there is no need here to guard 971 * against changes to or from NULL. 972 */ 973 if (dnh->dnh_dnode == NULL) { 974 zrl_destroy(&dnh->dnh_zrlock); 975 continue; 976 } 977 978 zrl_add(&dnh->dnh_zrlock); 979 dn = dnh->dnh_dnode; 980 /* 981 * If there are holds on this dnode, then there should 982 * be holds on the dnode's containing dbuf as well; thus 983 * it wouldn't be eligible for eviction and this function 984 * would not have been called. 985 */ 986 ASSERT(refcount_is_zero(&dn->dn_holds)); 987 ASSERT(refcount_is_zero(&dn->dn_tx_holds)); 988 989 dnode_destroy(dn); /* implicit zrl_remove() */ 990 zrl_destroy(&dnh->dnh_zrlock); 991 dnh->dnh_dnode = NULL; 992 } 993 kmem_free(children_dnodes, sizeof (dnode_children_t) + 994 (epb - 1) * sizeof (dnode_handle_t)); 995 } 996 997 /* 998 * errors: 999 * EINVAL - invalid object number. 1000 * EIO - i/o error. 1001 * succeeds even for free dnodes. 1002 */ 1003 int 1004 dnode_hold_impl(objset_t *os, uint64_t object, int flag, 1005 void *tag, dnode_t **dnp) 1006 { 1007 int epb, idx, err; 1008 int drop_struct_lock = FALSE; 1009 int type; 1010 uint64_t blk; 1011 dnode_t *mdn, *dn; 1012 dmu_buf_impl_t *db; 1013 dnode_children_t *children_dnodes; 1014 dnode_handle_t *dnh; 1015 1016 /* 1017 * If you are holding the spa config lock as writer, you shouldn't 1018 * be asking the DMU to do *anything* unless it's the root pool 1019 * which may require us to read from the root filesystem while 1020 * holding some (not all) of the locks as writer. 1021 */ 1022 ASSERT(spa_config_held(os->os_spa, SCL_ALL, RW_WRITER) == 0 || 1023 (spa_is_root(os->os_spa) && 1024 spa_config_held(os->os_spa, SCL_STATE, RW_WRITER))); 1025 1026 if (object == DMU_USERUSED_OBJECT || object == DMU_GROUPUSED_OBJECT) { 1027 dn = (object == DMU_USERUSED_OBJECT) ? 1028 DMU_USERUSED_DNODE(os) : DMU_GROUPUSED_DNODE(os); 1029 if (dn == NULL) 1030 return (ENOENT); 1031 type = dn->dn_type; 1032 if ((flag & DNODE_MUST_BE_ALLOCATED) && type == DMU_OT_NONE) 1033 return (ENOENT); 1034 if ((flag & DNODE_MUST_BE_FREE) && type != DMU_OT_NONE) 1035 return (EEXIST); 1036 DNODE_VERIFY(dn); 1037 (void) refcount_add(&dn->dn_holds, tag); 1038 *dnp = dn; 1039 return (0); 1040 } 1041 1042 if (object == 0 || object >= DN_MAX_OBJECT) 1043 return (EINVAL); 1044 1045 mdn = DMU_META_DNODE(os); 1046 ASSERT(mdn->dn_object == DMU_META_DNODE_OBJECT); 1047 1048 DNODE_VERIFY(mdn); 1049 1050 if (!RW_WRITE_HELD(&mdn->dn_struct_rwlock)) { 1051 rw_enter(&mdn->dn_struct_rwlock, RW_READER); 1052 drop_struct_lock = TRUE; 1053 } 1054 1055 blk = dbuf_whichblock(mdn, object * sizeof (dnode_phys_t)); 1056 1057 db = dbuf_hold(mdn, blk, FTAG); 1058 if (drop_struct_lock) 1059 rw_exit(&mdn->dn_struct_rwlock); 1060 if (db == NULL) 1061 return (EIO); 1062 err = dbuf_read(db, NULL, DB_RF_CANFAIL); 1063 if (err) { 1064 dbuf_rele(db, FTAG); 1065 return (err); 1066 } 1067 1068 ASSERT3U(db->db.db_size, >=, 1<<DNODE_SHIFT); 1069 epb = db->db.db_size >> DNODE_SHIFT; 1070 1071 idx = object & (epb-1); 1072 1073 ASSERT(DB_DNODE(db)->dn_type == DMU_OT_DNODE); 1074 children_dnodes = dmu_buf_get_user(&db->db); 1075 if (children_dnodes == NULL) { 1076 int i; 1077 dnode_children_t *winner; 1078 children_dnodes = kmem_alloc(sizeof (dnode_children_t) + 1079 (epb - 1) * sizeof (dnode_handle_t), KM_SLEEP); 1080 children_dnodes->dnc_count = epb; 1081 dnh = &children_dnodes->dnc_children[0]; 1082 for (i = 0; i < epb; i++) { 1083 zrl_init(&dnh[i].dnh_zrlock); 1084 dnh[i].dnh_dnode = NULL; 1085 } 1086 if (winner = dmu_buf_set_user(&db->db, children_dnodes, NULL, 1087 dnode_buf_pageout)) { 1088 kmem_free(children_dnodes, sizeof (dnode_children_t) + 1089 (epb - 1) * sizeof (dnode_handle_t)); 1090 children_dnodes = winner; 1091 } 1092 } 1093 ASSERT(children_dnodes->dnc_count == epb); 1094 1095 dnh = &children_dnodes->dnc_children[idx]; 1096 zrl_add(&dnh->dnh_zrlock); 1097 if ((dn = dnh->dnh_dnode) == NULL) { 1098 dnode_phys_t *phys = (dnode_phys_t *)db->db.db_data+idx; 1099 dnode_t *winner; 1100 1101 dn = dnode_create(os, phys, db, object, dnh); 1102 winner = atomic_cas_ptr(&dnh->dnh_dnode, NULL, dn); 1103 if (winner != NULL) { 1104 zrl_add(&dnh->dnh_zrlock); 1105 dnode_destroy(dn); /* implicit zrl_remove() */ 1106 dn = winner; 1107 } 1108 } 1109 1110 mutex_enter(&dn->dn_mtx); 1111 type = dn->dn_type; 1112 if (dn->dn_free_txg || 1113 ((flag & DNODE_MUST_BE_ALLOCATED) && type == DMU_OT_NONE) || 1114 ((flag & DNODE_MUST_BE_FREE) && 1115 (type != DMU_OT_NONE || !refcount_is_zero(&dn->dn_holds)))) { 1116 mutex_exit(&dn->dn_mtx); 1117 zrl_remove(&dnh->dnh_zrlock); 1118 dbuf_rele(db, FTAG); 1119 return (type == DMU_OT_NONE ? ENOENT : EEXIST); 1120 } 1121 mutex_exit(&dn->dn_mtx); 1122 1123 if (refcount_add(&dn->dn_holds, tag) == 1) 1124 dbuf_add_ref(db, dnh); 1125 /* Now we can rely on the hold to prevent the dnode from moving. */ 1126 zrl_remove(&dnh->dnh_zrlock); 1127 1128 DNODE_VERIFY(dn); 1129 ASSERT3P(dn->dn_dbuf, ==, db); 1130 ASSERT3U(dn->dn_object, ==, object); 1131 dbuf_rele(db, FTAG); 1132 1133 *dnp = dn; 1134 return (0); 1135 } 1136 1137 /* 1138 * Return held dnode if the object is allocated, NULL if not. 1139 */ 1140 int 1141 dnode_hold(objset_t *os, uint64_t object, void *tag, dnode_t **dnp) 1142 { 1143 return (dnode_hold_impl(os, object, DNODE_MUST_BE_ALLOCATED, tag, dnp)); 1144 } 1145 1146 /* 1147 * Can only add a reference if there is already at least one 1148 * reference on the dnode. Returns FALSE if unable to add a 1149 * new reference. 1150 */ 1151 boolean_t 1152 dnode_add_ref(dnode_t *dn, void *tag) 1153 { 1154 mutex_enter(&dn->dn_mtx); 1155 if (refcount_is_zero(&dn->dn_holds)) { 1156 mutex_exit(&dn->dn_mtx); 1157 return (FALSE); 1158 } 1159 VERIFY(1 < refcount_add(&dn->dn_holds, tag)); 1160 mutex_exit(&dn->dn_mtx); 1161 return (TRUE); 1162 } 1163 1164 void 1165 dnode_rele(dnode_t *dn, void *tag) 1166 { 1167 uint64_t refs; 1168 /* Get while the hold prevents the dnode from moving. */ 1169 dmu_buf_impl_t *db = dn->dn_dbuf; 1170 dnode_handle_t *dnh = dn->dn_handle; 1171 1172 mutex_enter(&dn->dn_mtx); 1173 refs = refcount_remove(&dn->dn_holds, tag); 1174 mutex_exit(&dn->dn_mtx); 1175 1176 /* 1177 * It's unsafe to release the last hold on a dnode by dnode_rele() or 1178 * indirectly by dbuf_rele() while relying on the dnode handle to 1179 * prevent the dnode from moving, since releasing the last hold could 1180 * result in the dnode's parent dbuf evicting its dnode handles. For 1181 * that reason anyone calling dnode_rele() or dbuf_rele() without some 1182 * other direct or indirect hold on the dnode must first drop the dnode 1183 * handle. 1184 */ 1185 ASSERT(refs > 0 || dnh->dnh_zrlock.zr_owner != curthread); 1186 1187 /* NOTE: the DNODE_DNODE does not have a dn_dbuf */ 1188 if (refs == 0 && db != NULL) { 1189 /* 1190 * Another thread could add a hold to the dnode handle in 1191 * dnode_hold_impl() while holding the parent dbuf. Since the 1192 * hold on the parent dbuf prevents the handle from being 1193 * destroyed, the hold on the handle is OK. We can't yet assert 1194 * that the handle has zero references, but that will be 1195 * asserted anyway when the handle gets destroyed. 1196 */ 1197 dbuf_rele(db, dnh); 1198 } 1199 } 1200 1201 void 1202 dnode_setdirty(dnode_t *dn, dmu_tx_t *tx) 1203 { 1204 objset_t *os = dn->dn_objset; 1205 uint64_t txg = tx->tx_txg; 1206 1207 if (DMU_OBJECT_IS_SPECIAL(dn->dn_object)) { 1208 dsl_dataset_dirty(os->os_dsl_dataset, tx); 1209 return; 1210 } 1211 1212 DNODE_VERIFY(dn); 1213 1214 #ifdef ZFS_DEBUG 1215 mutex_enter(&dn->dn_mtx); 1216 ASSERT(dn->dn_phys->dn_type || dn->dn_allocated_txg); 1217 ASSERT(dn->dn_free_txg == 0 || dn->dn_free_txg >= txg); 1218 mutex_exit(&dn->dn_mtx); 1219 #endif 1220 1221 /* 1222 * Determine old uid/gid when necessary 1223 */ 1224 dmu_objset_userquota_get_ids(dn, B_TRUE, tx); 1225 1226 mutex_enter(&os->os_lock); 1227 1228 /* 1229 * If we are already marked dirty, we're done. 1230 */ 1231 if (list_link_active(&dn->dn_dirty_link[txg & TXG_MASK])) { 1232 mutex_exit(&os->os_lock); 1233 return; 1234 } 1235 1236 ASSERT(!refcount_is_zero(&dn->dn_holds) || list_head(&dn->dn_dbufs)); 1237 ASSERT(dn->dn_datablksz != 0); 1238 ASSERT0(dn->dn_next_bonuslen[txg&TXG_MASK]); 1239 ASSERT0(dn->dn_next_blksz[txg&TXG_MASK]); 1240 ASSERT0(dn->dn_next_bonustype[txg&TXG_MASK]); 1241 1242 dprintf_ds(os->os_dsl_dataset, "obj=%llu txg=%llu\n", 1243 dn->dn_object, txg); 1244 1245 if (dn->dn_free_txg > 0 && dn->dn_free_txg <= txg) { 1246 list_insert_tail(&os->os_free_dnodes[txg&TXG_MASK], dn); 1247 } else { 1248 list_insert_tail(&os->os_dirty_dnodes[txg&TXG_MASK], dn); 1249 } 1250 1251 mutex_exit(&os->os_lock); 1252 1253 /* 1254 * The dnode maintains a hold on its containing dbuf as 1255 * long as there are holds on it. Each instantiated child 1256 * dbuf maintains a hold on the dnode. When the last child 1257 * drops its hold, the dnode will drop its hold on the 1258 * containing dbuf. We add a "dirty hold" here so that the 1259 * dnode will hang around after we finish processing its 1260 * children. 1261 */ 1262 VERIFY(dnode_add_ref(dn, (void *)(uintptr_t)tx->tx_txg)); 1263 1264 (void) dbuf_dirty(dn->dn_dbuf, tx); 1265 1266 dsl_dataset_dirty(os->os_dsl_dataset, tx); 1267 } 1268 1269 void 1270 dnode_free(dnode_t *dn, dmu_tx_t *tx) 1271 { 1272 int txgoff = tx->tx_txg & TXG_MASK; 1273 1274 dprintf("dn=%p txg=%llu\n", dn, tx->tx_txg); 1275 1276 /* we should be the only holder... hopefully */ 1277 /* ASSERT3U(refcount_count(&dn->dn_holds), ==, 1); */ 1278 1279 mutex_enter(&dn->dn_mtx); 1280 if (dn->dn_type == DMU_OT_NONE || dn->dn_free_txg) { 1281 mutex_exit(&dn->dn_mtx); 1282 return; 1283 } 1284 dn->dn_free_txg = tx->tx_txg; 1285 mutex_exit(&dn->dn_mtx); 1286 1287 /* 1288 * If the dnode is already dirty, it needs to be moved from 1289 * the dirty list to the free list. 1290 */ 1291 mutex_enter(&dn->dn_objset->os_lock); 1292 if (list_link_active(&dn->dn_dirty_link[txgoff])) { 1293 list_remove(&dn->dn_objset->os_dirty_dnodes[txgoff], dn); 1294 list_insert_tail(&dn->dn_objset->os_free_dnodes[txgoff], dn); 1295 mutex_exit(&dn->dn_objset->os_lock); 1296 } else { 1297 mutex_exit(&dn->dn_objset->os_lock); 1298 dnode_setdirty(dn, tx); 1299 } 1300 } 1301 1302 /* 1303 * Try to change the block size for the indicated dnode. This can only 1304 * succeed if there are no blocks allocated or dirty beyond first block 1305 */ 1306 int 1307 dnode_set_blksz(dnode_t *dn, uint64_t size, int ibs, dmu_tx_t *tx) 1308 { 1309 dmu_buf_impl_t *db, *db_next; 1310 int err; 1311 1312 if (size == 0) 1313 size = SPA_MINBLOCKSIZE; 1314 if (size > SPA_MAXBLOCKSIZE) 1315 size = SPA_MAXBLOCKSIZE; 1316 else 1317 size = P2ROUNDUP(size, SPA_MINBLOCKSIZE); 1318 1319 if (ibs == dn->dn_indblkshift) 1320 ibs = 0; 1321 1322 if (size >> SPA_MINBLOCKSHIFT == dn->dn_datablkszsec && ibs == 0) 1323 return (0); 1324 1325 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 1326 1327 /* Check for any allocated blocks beyond the first */ 1328 if (dn->dn_phys->dn_maxblkid != 0) 1329 goto fail; 1330 1331 mutex_enter(&dn->dn_dbufs_mtx); 1332 for (db = list_head(&dn->dn_dbufs); db; db = db_next) { 1333 db_next = list_next(&dn->dn_dbufs, db); 1334 1335 if (db->db_blkid != 0 && db->db_blkid != DMU_BONUS_BLKID && 1336 db->db_blkid != DMU_SPILL_BLKID) { 1337 mutex_exit(&dn->dn_dbufs_mtx); 1338 goto fail; 1339 } 1340 } 1341 mutex_exit(&dn->dn_dbufs_mtx); 1342 1343 if (ibs && dn->dn_nlevels != 1) 1344 goto fail; 1345 1346 /* resize the old block */ 1347 err = dbuf_hold_impl(dn, 0, 0, TRUE, FTAG, &db); 1348 if (err == 0) 1349 dbuf_new_size(db, size, tx); 1350 else if (err != ENOENT) 1351 goto fail; 1352 1353 dnode_setdblksz(dn, size); 1354 dnode_setdirty(dn, tx); 1355 dn->dn_next_blksz[tx->tx_txg&TXG_MASK] = size; 1356 if (ibs) { 1357 dn->dn_indblkshift = ibs; 1358 dn->dn_next_indblkshift[tx->tx_txg&TXG_MASK] = ibs; 1359 } 1360 /* rele after we have fixed the blocksize in the dnode */ 1361 if (db) 1362 dbuf_rele(db, FTAG); 1363 1364 rw_exit(&dn->dn_struct_rwlock); 1365 return (0); 1366 1367 fail: 1368 rw_exit(&dn->dn_struct_rwlock); 1369 return (ENOTSUP); 1370 } 1371 1372 /* read-holding callers must not rely on the lock being continuously held */ 1373 void 1374 dnode_new_blkid(dnode_t *dn, uint64_t blkid, dmu_tx_t *tx, boolean_t have_read) 1375 { 1376 uint64_t txgoff = tx->tx_txg & TXG_MASK; 1377 int epbs, new_nlevels; 1378 uint64_t sz; 1379 1380 ASSERT(blkid != DMU_BONUS_BLKID); 1381 1382 ASSERT(have_read ? 1383 RW_READ_HELD(&dn->dn_struct_rwlock) : 1384 RW_WRITE_HELD(&dn->dn_struct_rwlock)); 1385 1386 /* 1387 * if we have a read-lock, check to see if we need to do any work 1388 * before upgrading to a write-lock. 1389 */ 1390 if (have_read) { 1391 if (blkid <= dn->dn_maxblkid) 1392 return; 1393 1394 if (!rw_tryupgrade(&dn->dn_struct_rwlock)) { 1395 rw_exit(&dn->dn_struct_rwlock); 1396 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 1397 } 1398 } 1399 1400 if (blkid <= dn->dn_maxblkid) 1401 goto out; 1402 1403 dn->dn_maxblkid = blkid; 1404 1405 /* 1406 * Compute the number of levels necessary to support the new maxblkid. 1407 */ 1408 new_nlevels = 1; 1409 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT; 1410 for (sz = dn->dn_nblkptr; 1411 sz <= blkid && sz >= dn->dn_nblkptr; sz <<= epbs) 1412 new_nlevels++; 1413 1414 if (new_nlevels > dn->dn_nlevels) { 1415 int old_nlevels = dn->dn_nlevels; 1416 dmu_buf_impl_t *db; 1417 list_t *list; 1418 dbuf_dirty_record_t *new, *dr, *dr_next; 1419 1420 dn->dn_nlevels = new_nlevels; 1421 1422 ASSERT3U(new_nlevels, >, dn->dn_next_nlevels[txgoff]); 1423 dn->dn_next_nlevels[txgoff] = new_nlevels; 1424 1425 /* dirty the left indirects */ 1426 db = dbuf_hold_level(dn, old_nlevels, 0, FTAG); 1427 ASSERT(db != NULL); 1428 new = dbuf_dirty(db, tx); 1429 dbuf_rele(db, FTAG); 1430 1431 /* transfer the dirty records to the new indirect */ 1432 mutex_enter(&dn->dn_mtx); 1433 mutex_enter(&new->dt.di.dr_mtx); 1434 list = &dn->dn_dirty_records[txgoff]; 1435 for (dr = list_head(list); dr; dr = dr_next) { 1436 dr_next = list_next(&dn->dn_dirty_records[txgoff], dr); 1437 if (dr->dr_dbuf->db_level != new_nlevels-1 && 1438 dr->dr_dbuf->db_blkid != DMU_BONUS_BLKID && 1439 dr->dr_dbuf->db_blkid != DMU_SPILL_BLKID) { 1440 ASSERT(dr->dr_dbuf->db_level == old_nlevels-1); 1441 list_remove(&dn->dn_dirty_records[txgoff], dr); 1442 list_insert_tail(&new->dt.di.dr_children, dr); 1443 dr->dr_parent = new; 1444 } 1445 } 1446 mutex_exit(&new->dt.di.dr_mtx); 1447 mutex_exit(&dn->dn_mtx); 1448 } 1449 1450 out: 1451 if (have_read) 1452 rw_downgrade(&dn->dn_struct_rwlock); 1453 } 1454 1455 void 1456 dnode_clear_range(dnode_t *dn, uint64_t blkid, uint64_t nblks, dmu_tx_t *tx) 1457 { 1458 avl_tree_t *tree = &dn->dn_ranges[tx->tx_txg&TXG_MASK]; 1459 avl_index_t where; 1460 free_range_t *rp; 1461 free_range_t rp_tofind; 1462 uint64_t endblk = blkid + nblks; 1463 1464 ASSERT(MUTEX_HELD(&dn->dn_mtx)); 1465 ASSERT(nblks <= UINT64_MAX - blkid); /* no overflow */ 1466 1467 dprintf_dnode(dn, "blkid=%llu nblks=%llu txg=%llu\n", 1468 blkid, nblks, tx->tx_txg); 1469 rp_tofind.fr_blkid = blkid; 1470 rp = avl_find(tree, &rp_tofind, &where); 1471 if (rp == NULL) 1472 rp = avl_nearest(tree, where, AVL_BEFORE); 1473 if (rp == NULL) 1474 rp = avl_nearest(tree, where, AVL_AFTER); 1475 1476 while (rp && (rp->fr_blkid <= blkid + nblks)) { 1477 uint64_t fr_endblk = rp->fr_blkid + rp->fr_nblks; 1478 free_range_t *nrp = AVL_NEXT(tree, rp); 1479 1480 if (blkid <= rp->fr_blkid && endblk >= fr_endblk) { 1481 /* clear this entire range */ 1482 avl_remove(tree, rp); 1483 kmem_free(rp, sizeof (free_range_t)); 1484 } else if (blkid <= rp->fr_blkid && 1485 endblk > rp->fr_blkid && endblk < fr_endblk) { 1486 /* clear the beginning of this range */ 1487 rp->fr_blkid = endblk; 1488 rp->fr_nblks = fr_endblk - endblk; 1489 } else if (blkid > rp->fr_blkid && blkid < fr_endblk && 1490 endblk >= fr_endblk) { 1491 /* clear the end of this range */ 1492 rp->fr_nblks = blkid - rp->fr_blkid; 1493 } else if (blkid > rp->fr_blkid && endblk < fr_endblk) { 1494 /* clear a chunk out of this range */ 1495 free_range_t *new_rp = 1496 kmem_alloc(sizeof (free_range_t), KM_SLEEP); 1497 1498 new_rp->fr_blkid = endblk; 1499 new_rp->fr_nblks = fr_endblk - endblk; 1500 avl_insert_here(tree, new_rp, rp, AVL_AFTER); 1501 rp->fr_nblks = blkid - rp->fr_blkid; 1502 } 1503 /* there may be no overlap */ 1504 rp = nrp; 1505 } 1506 } 1507 1508 void 1509 dnode_free_range(dnode_t *dn, uint64_t off, uint64_t len, dmu_tx_t *tx) 1510 { 1511 dmu_buf_impl_t *db; 1512 uint64_t blkoff, blkid, nblks; 1513 int blksz, blkshift, head, tail; 1514 int trunc = FALSE; 1515 int epbs; 1516 1517 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 1518 blksz = dn->dn_datablksz; 1519 blkshift = dn->dn_datablkshift; 1520 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT; 1521 1522 if (len == -1ULL) { 1523 len = UINT64_MAX - off; 1524 trunc = TRUE; 1525 } 1526 1527 /* 1528 * First, block align the region to free: 1529 */ 1530 if (ISP2(blksz)) { 1531 head = P2NPHASE(off, blksz); 1532 blkoff = P2PHASE(off, blksz); 1533 if ((off >> blkshift) > dn->dn_maxblkid) 1534 goto out; 1535 } else { 1536 ASSERT(dn->dn_maxblkid == 0); 1537 if (off == 0 && len >= blksz) { 1538 /* Freeing the whole block; fast-track this request */ 1539 blkid = 0; 1540 nblks = 1; 1541 goto done; 1542 } else if (off >= blksz) { 1543 /* Freeing past end-of-data */ 1544 goto out; 1545 } else { 1546 /* Freeing part of the block. */ 1547 head = blksz - off; 1548 ASSERT3U(head, >, 0); 1549 } 1550 blkoff = off; 1551 } 1552 /* zero out any partial block data at the start of the range */ 1553 if (head) { 1554 ASSERT3U(blkoff + head, ==, blksz); 1555 if (len < head) 1556 head = len; 1557 if (dbuf_hold_impl(dn, 0, dbuf_whichblock(dn, off), TRUE, 1558 FTAG, &db) == 0) { 1559 caddr_t data; 1560 1561 /* don't dirty if it isn't on disk and isn't dirty */ 1562 if (db->db_last_dirty || 1563 (db->db_blkptr && !BP_IS_HOLE(db->db_blkptr))) { 1564 rw_exit(&dn->dn_struct_rwlock); 1565 dbuf_will_dirty(db, tx); 1566 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 1567 data = db->db.db_data; 1568 bzero(data + blkoff, head); 1569 } 1570 dbuf_rele(db, FTAG); 1571 } 1572 off += head; 1573 len -= head; 1574 } 1575 1576 /* If the range was less than one block, we're done */ 1577 if (len == 0) 1578 goto out; 1579 1580 /* If the remaining range is past end of file, we're done */ 1581 if ((off >> blkshift) > dn->dn_maxblkid) 1582 goto out; 1583 1584 ASSERT(ISP2(blksz)); 1585 if (trunc) 1586 tail = 0; 1587 else 1588 tail = P2PHASE(len, blksz); 1589 1590 ASSERT0(P2PHASE(off, blksz)); 1591 /* zero out any partial block data at the end of the range */ 1592 if (tail) { 1593 if (len < tail) 1594 tail = len; 1595 if (dbuf_hold_impl(dn, 0, dbuf_whichblock(dn, off+len), 1596 TRUE, FTAG, &db) == 0) { 1597 /* don't dirty if not on disk and not dirty */ 1598 if (db->db_last_dirty || 1599 (db->db_blkptr && !BP_IS_HOLE(db->db_blkptr))) { 1600 rw_exit(&dn->dn_struct_rwlock); 1601 dbuf_will_dirty(db, tx); 1602 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 1603 bzero(db->db.db_data, tail); 1604 } 1605 dbuf_rele(db, FTAG); 1606 } 1607 len -= tail; 1608 } 1609 1610 /* If the range did not include a full block, we are done */ 1611 if (len == 0) 1612 goto out; 1613 1614 ASSERT(IS_P2ALIGNED(off, blksz)); 1615 ASSERT(trunc || IS_P2ALIGNED(len, blksz)); 1616 blkid = off >> blkshift; 1617 nblks = len >> blkshift; 1618 if (trunc) 1619 nblks += 1; 1620 1621 /* 1622 * Read in and mark all the level-1 indirects dirty, 1623 * so that they will stay in memory until syncing phase. 1624 * Always dirty the first and last indirect to make sure 1625 * we dirty all the partial indirects. 1626 */ 1627 if (dn->dn_nlevels > 1) { 1628 uint64_t i, first, last; 1629 int shift = epbs + dn->dn_datablkshift; 1630 1631 first = blkid >> epbs; 1632 if (db = dbuf_hold_level(dn, 1, first, FTAG)) { 1633 dbuf_will_dirty(db, tx); 1634 dbuf_rele(db, FTAG); 1635 } 1636 if (trunc) 1637 last = dn->dn_maxblkid >> epbs; 1638 else 1639 last = (blkid + nblks - 1) >> epbs; 1640 if (last > first && (db = dbuf_hold_level(dn, 1, last, FTAG))) { 1641 dbuf_will_dirty(db, tx); 1642 dbuf_rele(db, FTAG); 1643 } 1644 for (i = first + 1; i < last; i++) { 1645 uint64_t ibyte = i << shift; 1646 int err; 1647 1648 err = dnode_next_offset(dn, 1649 DNODE_FIND_HAVELOCK, &ibyte, 1, 1, 0); 1650 i = ibyte >> shift; 1651 if (err == ESRCH || i >= last) 1652 break; 1653 ASSERT(err == 0); 1654 db = dbuf_hold_level(dn, 1, i, FTAG); 1655 if (db) { 1656 dbuf_will_dirty(db, tx); 1657 dbuf_rele(db, FTAG); 1658 } 1659 } 1660 } 1661 done: 1662 /* 1663 * Add this range to the dnode range list. 1664 * We will finish up this free operation in the syncing phase. 1665 */ 1666 mutex_enter(&dn->dn_mtx); 1667 dnode_clear_range(dn, blkid, nblks, tx); 1668 { 1669 free_range_t *rp, *found; 1670 avl_index_t where; 1671 avl_tree_t *tree = &dn->dn_ranges[tx->tx_txg&TXG_MASK]; 1672 1673 /* Add new range to dn_ranges */ 1674 rp = kmem_alloc(sizeof (free_range_t), KM_SLEEP); 1675 rp->fr_blkid = blkid; 1676 rp->fr_nblks = nblks; 1677 found = avl_find(tree, rp, &where); 1678 ASSERT(found == NULL); 1679 avl_insert(tree, rp, where); 1680 dprintf_dnode(dn, "blkid=%llu nblks=%llu txg=%llu\n", 1681 blkid, nblks, tx->tx_txg); 1682 } 1683 mutex_exit(&dn->dn_mtx); 1684 1685 dbuf_free_range(dn, blkid, blkid + nblks - 1, tx); 1686 dnode_setdirty(dn, tx); 1687 out: 1688 if (trunc && dn->dn_maxblkid >= (off >> blkshift)) 1689 dn->dn_maxblkid = (off >> blkshift ? (off >> blkshift) - 1 : 0); 1690 1691 rw_exit(&dn->dn_struct_rwlock); 1692 } 1693 1694 static boolean_t 1695 dnode_spill_freed(dnode_t *dn) 1696 { 1697 int i; 1698 1699 mutex_enter(&dn->dn_mtx); 1700 for (i = 0; i < TXG_SIZE; i++) { 1701 if (dn->dn_rm_spillblk[i] == DN_KILL_SPILLBLK) 1702 break; 1703 } 1704 mutex_exit(&dn->dn_mtx); 1705 return (i < TXG_SIZE); 1706 } 1707 1708 /* return TRUE if this blkid was freed in a recent txg, or FALSE if it wasn't */ 1709 uint64_t 1710 dnode_block_freed(dnode_t *dn, uint64_t blkid) 1711 { 1712 free_range_t range_tofind; 1713 void *dp = spa_get_dsl(dn->dn_objset->os_spa); 1714 int i; 1715 1716 if (blkid == DMU_BONUS_BLKID) 1717 return (FALSE); 1718 1719 /* 1720 * If we're in the process of opening the pool, dp will not be 1721 * set yet, but there shouldn't be anything dirty. 1722 */ 1723 if (dp == NULL) 1724 return (FALSE); 1725 1726 if (dn->dn_free_txg) 1727 return (TRUE); 1728 1729 if (blkid == DMU_SPILL_BLKID) 1730 return (dnode_spill_freed(dn)); 1731 1732 range_tofind.fr_blkid = blkid; 1733 mutex_enter(&dn->dn_mtx); 1734 for (i = 0; i < TXG_SIZE; i++) { 1735 free_range_t *range_found; 1736 avl_index_t idx; 1737 1738 range_found = avl_find(&dn->dn_ranges[i], &range_tofind, &idx); 1739 if (range_found) { 1740 ASSERT(range_found->fr_nblks > 0); 1741 break; 1742 } 1743 range_found = avl_nearest(&dn->dn_ranges[i], idx, AVL_BEFORE); 1744 if (range_found && 1745 range_found->fr_blkid + range_found->fr_nblks > blkid) 1746 break; 1747 } 1748 mutex_exit(&dn->dn_mtx); 1749 return (i < TXG_SIZE); 1750 } 1751 1752 /* call from syncing context when we actually write/free space for this dnode */ 1753 void 1754 dnode_diduse_space(dnode_t *dn, int64_t delta) 1755 { 1756 uint64_t space; 1757 dprintf_dnode(dn, "dn=%p dnp=%p used=%llu delta=%lld\n", 1758 dn, dn->dn_phys, 1759 (u_longlong_t)dn->dn_phys->dn_used, 1760 (longlong_t)delta); 1761 1762 mutex_enter(&dn->dn_mtx); 1763 space = DN_USED_BYTES(dn->dn_phys); 1764 if (delta > 0) { 1765 ASSERT3U(space + delta, >=, space); /* no overflow */ 1766 } else { 1767 ASSERT3U(space, >=, -delta); /* no underflow */ 1768 } 1769 space += delta; 1770 if (spa_version(dn->dn_objset->os_spa) < SPA_VERSION_DNODE_BYTES) { 1771 ASSERT((dn->dn_phys->dn_flags & DNODE_FLAG_USED_BYTES) == 0); 1772 ASSERT0(P2PHASE(space, 1<<DEV_BSHIFT)); 1773 dn->dn_phys->dn_used = space >> DEV_BSHIFT; 1774 } else { 1775 dn->dn_phys->dn_used = space; 1776 dn->dn_phys->dn_flags |= DNODE_FLAG_USED_BYTES; 1777 } 1778 mutex_exit(&dn->dn_mtx); 1779 } 1780 1781 /* 1782 * Call when we think we're going to write/free space in open context. 1783 * Be conservative (ie. OK to write less than this or free more than 1784 * this, but don't write more or free less). 1785 */ 1786 void 1787 dnode_willuse_space(dnode_t *dn, int64_t space, dmu_tx_t *tx) 1788 { 1789 objset_t *os = dn->dn_objset; 1790 dsl_dataset_t *ds = os->os_dsl_dataset; 1791 1792 if (space > 0) 1793 space = spa_get_asize(os->os_spa, space); 1794 1795 if (ds) 1796 dsl_dir_willuse_space(ds->ds_dir, space, tx); 1797 1798 dmu_tx_willuse_space(tx, space); 1799 } 1800 1801 /* 1802 * This function scans a block at the indicated "level" looking for 1803 * a hole or data (depending on 'flags'). If level > 0, then we are 1804 * scanning an indirect block looking at its pointers. If level == 0, 1805 * then we are looking at a block of dnodes. If we don't find what we 1806 * are looking for in the block, we return ESRCH. Otherwise, return 1807 * with *offset pointing to the beginning (if searching forwards) or 1808 * end (if searching backwards) of the range covered by the block 1809 * pointer we matched on (or dnode). 1810 * 1811 * The basic search algorithm used below by dnode_next_offset() is to 1812 * use this function to search up the block tree (widen the search) until 1813 * we find something (i.e., we don't return ESRCH) and then search back 1814 * down the tree (narrow the search) until we reach our original search 1815 * level. 1816 */ 1817 static int 1818 dnode_next_offset_level(dnode_t *dn, int flags, uint64_t *offset, 1819 int lvl, uint64_t blkfill, uint64_t txg) 1820 { 1821 dmu_buf_impl_t *db = NULL; 1822 void *data = NULL; 1823 uint64_t epbs = dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT; 1824 uint64_t epb = 1ULL << epbs; 1825 uint64_t minfill, maxfill; 1826 boolean_t hole; 1827 int i, inc, error, span; 1828 1829 dprintf("probing object %llu offset %llx level %d of %u\n", 1830 dn->dn_object, *offset, lvl, dn->dn_phys->dn_nlevels); 1831 1832 hole = ((flags & DNODE_FIND_HOLE) != 0); 1833 inc = (flags & DNODE_FIND_BACKWARDS) ? -1 : 1; 1834 ASSERT(txg == 0 || !hole); 1835 1836 if (lvl == dn->dn_phys->dn_nlevels) { 1837 error = 0; 1838 epb = dn->dn_phys->dn_nblkptr; 1839 data = dn->dn_phys->dn_blkptr; 1840 } else { 1841 uint64_t blkid = dbuf_whichblock(dn, *offset) >> (epbs * lvl); 1842 error = dbuf_hold_impl(dn, lvl, blkid, TRUE, FTAG, &db); 1843 if (error) { 1844 if (error != ENOENT) 1845 return (error); 1846 if (hole) 1847 return (0); 1848 /* 1849 * This can only happen when we are searching up 1850 * the block tree for data. We don't really need to 1851 * adjust the offset, as we will just end up looking 1852 * at the pointer to this block in its parent, and its 1853 * going to be unallocated, so we will skip over it. 1854 */ 1855 return (ESRCH); 1856 } 1857 error = dbuf_read(db, NULL, DB_RF_CANFAIL | DB_RF_HAVESTRUCT); 1858 if (error) { 1859 dbuf_rele(db, FTAG); 1860 return (error); 1861 } 1862 data = db->db.db_data; 1863 } 1864 1865 if (db && txg && 1866 (db->db_blkptr == NULL || db->db_blkptr->blk_birth <= txg)) { 1867 /* 1868 * This can only happen when we are searching up the tree 1869 * and these conditions mean that we need to keep climbing. 1870 */ 1871 error = ESRCH; 1872 } else if (lvl == 0) { 1873 dnode_phys_t *dnp = data; 1874 span = DNODE_SHIFT; 1875 ASSERT(dn->dn_type == DMU_OT_DNODE); 1876 1877 for (i = (*offset >> span) & (blkfill - 1); 1878 i >= 0 && i < blkfill; i += inc) { 1879 if ((dnp[i].dn_type == DMU_OT_NONE) == hole) 1880 break; 1881 *offset += (1ULL << span) * inc; 1882 } 1883 if (i < 0 || i == blkfill) 1884 error = ESRCH; 1885 } else { 1886 blkptr_t *bp = data; 1887 uint64_t start = *offset; 1888 span = (lvl - 1) * epbs + dn->dn_datablkshift; 1889 minfill = 0; 1890 maxfill = blkfill << ((lvl - 1) * epbs); 1891 1892 if (hole) 1893 maxfill--; 1894 else 1895 minfill++; 1896 1897 *offset = *offset >> span; 1898 for (i = BF64_GET(*offset, 0, epbs); 1899 i >= 0 && i < epb; i += inc) { 1900 if (bp[i].blk_fill >= minfill && 1901 bp[i].blk_fill <= maxfill && 1902 (hole || bp[i].blk_birth > txg)) 1903 break; 1904 if (inc > 0 || *offset > 0) 1905 *offset += inc; 1906 } 1907 *offset = *offset << span; 1908 if (inc < 0) { 1909 /* traversing backwards; position offset at the end */ 1910 ASSERT3U(*offset, <=, start); 1911 *offset = MIN(*offset + (1ULL << span) - 1, start); 1912 } else if (*offset < start) { 1913 *offset = start; 1914 } 1915 if (i < 0 || i >= epb) 1916 error = ESRCH; 1917 } 1918 1919 if (db) 1920 dbuf_rele(db, FTAG); 1921 1922 return (error); 1923 } 1924 1925 /* 1926 * Find the next hole, data, or sparse region at or after *offset. 1927 * The value 'blkfill' tells us how many items we expect to find 1928 * in an L0 data block; this value is 1 for normal objects, 1929 * DNODES_PER_BLOCK for the meta dnode, and some fraction of 1930 * DNODES_PER_BLOCK when searching for sparse regions thereof. 1931 * 1932 * Examples: 1933 * 1934 * dnode_next_offset(dn, flags, offset, 1, 1, 0); 1935 * Finds the next/previous hole/data in a file. 1936 * Used in dmu_offset_next(). 1937 * 1938 * dnode_next_offset(mdn, flags, offset, 0, DNODES_PER_BLOCK, txg); 1939 * Finds the next free/allocated dnode an objset's meta-dnode. 1940 * Only finds objects that have new contents since txg (ie. 1941 * bonus buffer changes and content removal are ignored). 1942 * Used in dmu_object_next(). 1943 * 1944 * dnode_next_offset(mdn, DNODE_FIND_HOLE, offset, 2, DNODES_PER_BLOCK >> 2, 0); 1945 * Finds the next L2 meta-dnode bp that's at most 1/4 full. 1946 * Used in dmu_object_alloc(). 1947 */ 1948 int 1949 dnode_next_offset(dnode_t *dn, int flags, uint64_t *offset, 1950 int minlvl, uint64_t blkfill, uint64_t txg) 1951 { 1952 uint64_t initial_offset = *offset; 1953 int lvl, maxlvl; 1954 int error = 0; 1955 1956 if (!(flags & DNODE_FIND_HAVELOCK)) 1957 rw_enter(&dn->dn_struct_rwlock, RW_READER); 1958 1959 if (dn->dn_phys->dn_nlevels == 0) { 1960 error = ESRCH; 1961 goto out; 1962 } 1963 1964 if (dn->dn_datablkshift == 0) { 1965 if (*offset < dn->dn_datablksz) { 1966 if (flags & DNODE_FIND_HOLE) 1967 *offset = dn->dn_datablksz; 1968 } else { 1969 error = ESRCH; 1970 } 1971 goto out; 1972 } 1973 1974 maxlvl = dn->dn_phys->dn_nlevels; 1975 1976 for (lvl = minlvl; lvl <= maxlvl; lvl++) { 1977 error = dnode_next_offset_level(dn, 1978 flags, offset, lvl, blkfill, txg); 1979 if (error != ESRCH) 1980 break; 1981 } 1982 1983 while (error == 0 && --lvl >= minlvl) { 1984 error = dnode_next_offset_level(dn, 1985 flags, offset, lvl, blkfill, txg); 1986 } 1987 1988 if (error == 0 && (flags & DNODE_FIND_BACKWARDS ? 1989 initial_offset < *offset : initial_offset > *offset)) 1990 error = ESRCH; 1991 out: 1992 if (!(flags & DNODE_FIND_HAVELOCK)) 1993 rw_exit(&dn->dn_struct_rwlock); 1994 1995 return (error); 1996 } 1997