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 dn->dn_unlisted_l0_blkid = 0; 119 list_create(&dn->dn_dbufs, sizeof (dmu_buf_impl_t), 120 offsetof(dmu_buf_impl_t, db_link)); 121 122 dn->dn_moved = 0; 123 return (0); 124 } 125 126 /* ARGSUSED */ 127 static void 128 dnode_dest(void *arg, void *unused) 129 { 130 int i; 131 dnode_t *dn = arg; 132 133 rw_destroy(&dn->dn_struct_rwlock); 134 mutex_destroy(&dn->dn_mtx); 135 mutex_destroy(&dn->dn_dbufs_mtx); 136 cv_destroy(&dn->dn_notxholds); 137 refcount_destroy(&dn->dn_holds); 138 refcount_destroy(&dn->dn_tx_holds); 139 ASSERT(!list_link_active(&dn->dn_link)); 140 141 for (i = 0; i < TXG_SIZE; i++) { 142 ASSERT(!list_link_active(&dn->dn_dirty_link[i])); 143 avl_destroy(&dn->dn_ranges[i]); 144 list_destroy(&dn->dn_dirty_records[i]); 145 ASSERT0(dn->dn_next_nblkptr[i]); 146 ASSERT0(dn->dn_next_nlevels[i]); 147 ASSERT0(dn->dn_next_indblkshift[i]); 148 ASSERT0(dn->dn_next_bonustype[i]); 149 ASSERT0(dn->dn_rm_spillblk[i]); 150 ASSERT0(dn->dn_next_bonuslen[i]); 151 ASSERT0(dn->dn_next_blksz[i]); 152 } 153 154 ASSERT0(dn->dn_allocated_txg); 155 ASSERT0(dn->dn_free_txg); 156 ASSERT0(dn->dn_assigned_txg); 157 ASSERT0(dn->dn_dirtyctx); 158 ASSERT3P(dn->dn_dirtyctx_firstset, ==, NULL); 159 ASSERT3P(dn->dn_bonus, ==, NULL); 160 ASSERT(!dn->dn_have_spill); 161 ASSERT3P(dn->dn_zio, ==, NULL); 162 ASSERT0(dn->dn_oldused); 163 ASSERT0(dn->dn_oldflags); 164 ASSERT0(dn->dn_olduid); 165 ASSERT0(dn->dn_oldgid); 166 ASSERT0(dn->dn_newuid); 167 ASSERT0(dn->dn_newgid); 168 ASSERT0(dn->dn_id_flags); 169 170 ASSERT0(dn->dn_dbufs_count); 171 ASSERT0(dn->dn_unlisted_l0_blkid); 172 list_destroy(&dn->dn_dbufs); 173 } 174 175 void 176 dnode_init(void) 177 { 178 ASSERT(dnode_cache == NULL); 179 dnode_cache = kmem_cache_create("dnode_t", 180 sizeof (dnode_t), 181 0, dnode_cons, dnode_dest, NULL, NULL, NULL, 0); 182 kmem_cache_set_move(dnode_cache, dnode_move); 183 } 184 185 void 186 dnode_fini(void) 187 { 188 kmem_cache_destroy(dnode_cache); 189 dnode_cache = NULL; 190 } 191 192 193 #ifdef ZFS_DEBUG 194 void 195 dnode_verify(dnode_t *dn) 196 { 197 int drop_struct_lock = FALSE; 198 199 ASSERT(dn->dn_phys); 200 ASSERT(dn->dn_objset); 201 ASSERT(dn->dn_handle->dnh_dnode == dn); 202 203 ASSERT(DMU_OT_IS_VALID(dn->dn_phys->dn_type)); 204 205 if (!(zfs_flags & ZFS_DEBUG_DNODE_VERIFY)) 206 return; 207 208 if (!RW_WRITE_HELD(&dn->dn_struct_rwlock)) { 209 rw_enter(&dn->dn_struct_rwlock, RW_READER); 210 drop_struct_lock = TRUE; 211 } 212 if (dn->dn_phys->dn_type != DMU_OT_NONE || dn->dn_allocated_txg != 0) { 213 int i; 214 ASSERT3U(dn->dn_indblkshift, >=, 0); 215 ASSERT3U(dn->dn_indblkshift, <=, SPA_MAXBLOCKSHIFT); 216 if (dn->dn_datablkshift) { 217 ASSERT3U(dn->dn_datablkshift, >=, SPA_MINBLOCKSHIFT); 218 ASSERT3U(dn->dn_datablkshift, <=, SPA_MAXBLOCKSHIFT); 219 ASSERT3U(1<<dn->dn_datablkshift, ==, dn->dn_datablksz); 220 } 221 ASSERT3U(dn->dn_nlevels, <=, 30); 222 ASSERT(DMU_OT_IS_VALID(dn->dn_type)); 223 ASSERT3U(dn->dn_nblkptr, >=, 1); 224 ASSERT3U(dn->dn_nblkptr, <=, DN_MAX_NBLKPTR); 225 ASSERT3U(dn->dn_bonuslen, <=, DN_MAX_BONUSLEN); 226 ASSERT3U(dn->dn_datablksz, ==, 227 dn->dn_datablkszsec << SPA_MINBLOCKSHIFT); 228 ASSERT3U(ISP2(dn->dn_datablksz), ==, dn->dn_datablkshift != 0); 229 ASSERT3U((dn->dn_nblkptr - 1) * sizeof (blkptr_t) + 230 dn->dn_bonuslen, <=, DN_MAX_BONUSLEN); 231 for (i = 0; i < TXG_SIZE; i++) { 232 ASSERT3U(dn->dn_next_nlevels[i], <=, dn->dn_nlevels); 233 } 234 } 235 if (dn->dn_phys->dn_type != DMU_OT_NONE) 236 ASSERT3U(dn->dn_phys->dn_nlevels, <=, dn->dn_nlevels); 237 ASSERT(DMU_OBJECT_IS_SPECIAL(dn->dn_object) || dn->dn_dbuf != NULL); 238 if (dn->dn_dbuf != NULL) { 239 ASSERT3P(dn->dn_phys, ==, 240 (dnode_phys_t *)dn->dn_dbuf->db.db_data + 241 (dn->dn_object % (dn->dn_dbuf->db.db_size >> DNODE_SHIFT))); 242 } 243 if (drop_struct_lock) 244 rw_exit(&dn->dn_struct_rwlock); 245 } 246 #endif 247 248 void 249 dnode_byteswap(dnode_phys_t *dnp) 250 { 251 uint64_t *buf64 = (void*)&dnp->dn_blkptr; 252 int i; 253 254 if (dnp->dn_type == DMU_OT_NONE) { 255 bzero(dnp, sizeof (dnode_phys_t)); 256 return; 257 } 258 259 dnp->dn_datablkszsec = BSWAP_16(dnp->dn_datablkszsec); 260 dnp->dn_bonuslen = BSWAP_16(dnp->dn_bonuslen); 261 dnp->dn_maxblkid = BSWAP_64(dnp->dn_maxblkid); 262 dnp->dn_used = BSWAP_64(dnp->dn_used); 263 264 /* 265 * dn_nblkptr is only one byte, so it's OK to read it in either 266 * byte order. We can't read dn_bouslen. 267 */ 268 ASSERT(dnp->dn_indblkshift <= SPA_MAXBLOCKSHIFT); 269 ASSERT(dnp->dn_nblkptr <= DN_MAX_NBLKPTR); 270 for (i = 0; i < dnp->dn_nblkptr * sizeof (blkptr_t)/8; i++) 271 buf64[i] = BSWAP_64(buf64[i]); 272 273 /* 274 * OK to check dn_bonuslen for zero, because it won't matter if 275 * we have the wrong byte order. This is necessary because the 276 * dnode dnode is smaller than a regular dnode. 277 */ 278 if (dnp->dn_bonuslen != 0) { 279 /* 280 * Note that the bonus length calculated here may be 281 * longer than the actual bonus buffer. This is because 282 * we always put the bonus buffer after the last block 283 * pointer (instead of packing it against the end of the 284 * dnode buffer). 285 */ 286 int off = (dnp->dn_nblkptr-1) * sizeof (blkptr_t); 287 size_t len = DN_MAX_BONUSLEN - off; 288 ASSERT(DMU_OT_IS_VALID(dnp->dn_bonustype)); 289 dmu_object_byteswap_t byteswap = 290 DMU_OT_BYTESWAP(dnp->dn_bonustype); 291 dmu_ot_byteswap[byteswap].ob_func(dnp->dn_bonus + off, len); 292 } 293 294 /* Swap SPILL block if we have one */ 295 if (dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) 296 byteswap_uint64_array(&dnp->dn_spill, sizeof (blkptr_t)); 297 298 } 299 300 void 301 dnode_buf_byteswap(void *vbuf, size_t size) 302 { 303 dnode_phys_t *buf = vbuf; 304 int i; 305 306 ASSERT3U(sizeof (dnode_phys_t), ==, (1<<DNODE_SHIFT)); 307 ASSERT((size & (sizeof (dnode_phys_t)-1)) == 0); 308 309 size >>= DNODE_SHIFT; 310 for (i = 0; i < size; i++) { 311 dnode_byteswap(buf); 312 buf++; 313 } 314 } 315 316 static int 317 free_range_compar(const void *node1, const void *node2) 318 { 319 const free_range_t *rp1 = node1; 320 const free_range_t *rp2 = node2; 321 322 if (rp1->fr_blkid < rp2->fr_blkid) 323 return (-1); 324 else if (rp1->fr_blkid > rp2->fr_blkid) 325 return (1); 326 else return (0); 327 } 328 329 void 330 dnode_setbonuslen(dnode_t *dn, int newsize, dmu_tx_t *tx) 331 { 332 ASSERT3U(refcount_count(&dn->dn_holds), >=, 1); 333 334 dnode_setdirty(dn, tx); 335 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 336 ASSERT3U(newsize, <=, DN_MAX_BONUSLEN - 337 (dn->dn_nblkptr-1) * sizeof (blkptr_t)); 338 dn->dn_bonuslen = newsize; 339 if (newsize == 0) 340 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = DN_ZERO_BONUSLEN; 341 else 342 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = dn->dn_bonuslen; 343 rw_exit(&dn->dn_struct_rwlock); 344 } 345 346 void 347 dnode_setbonus_type(dnode_t *dn, dmu_object_type_t newtype, dmu_tx_t *tx) 348 { 349 ASSERT3U(refcount_count(&dn->dn_holds), >=, 1); 350 dnode_setdirty(dn, tx); 351 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 352 dn->dn_bonustype = newtype; 353 dn->dn_next_bonustype[tx->tx_txg & TXG_MASK] = dn->dn_bonustype; 354 rw_exit(&dn->dn_struct_rwlock); 355 } 356 357 void 358 dnode_rm_spill(dnode_t *dn, dmu_tx_t *tx) 359 { 360 ASSERT3U(refcount_count(&dn->dn_holds), >=, 1); 361 ASSERT(RW_WRITE_HELD(&dn->dn_struct_rwlock)); 362 dnode_setdirty(dn, tx); 363 dn->dn_rm_spillblk[tx->tx_txg&TXG_MASK] = DN_KILL_SPILLBLK; 364 dn->dn_have_spill = B_FALSE; 365 } 366 367 static void 368 dnode_setdblksz(dnode_t *dn, int size) 369 { 370 ASSERT0(P2PHASE(size, SPA_MINBLOCKSIZE)); 371 ASSERT3U(size, <=, SPA_MAXBLOCKSIZE); 372 ASSERT3U(size, >=, SPA_MINBLOCKSIZE); 373 ASSERT3U(size >> SPA_MINBLOCKSHIFT, <, 374 1<<(sizeof (dn->dn_phys->dn_datablkszsec) * 8)); 375 dn->dn_datablksz = size; 376 dn->dn_datablkszsec = size >> SPA_MINBLOCKSHIFT; 377 dn->dn_datablkshift = ISP2(size) ? highbit(size - 1) : 0; 378 } 379 380 static dnode_t * 381 dnode_create(objset_t *os, dnode_phys_t *dnp, dmu_buf_impl_t *db, 382 uint64_t object, dnode_handle_t *dnh) 383 { 384 dnode_t *dn = kmem_cache_alloc(dnode_cache, KM_SLEEP); 385 386 ASSERT(!POINTER_IS_VALID(dn->dn_objset)); 387 dn->dn_moved = 0; 388 389 /* 390 * Defer setting dn_objset until the dnode is ready to be a candidate 391 * for the dnode_move() callback. 392 */ 393 dn->dn_object = object; 394 dn->dn_dbuf = db; 395 dn->dn_handle = dnh; 396 dn->dn_phys = dnp; 397 398 if (dnp->dn_datablkszsec) { 399 dnode_setdblksz(dn, dnp->dn_datablkszsec << SPA_MINBLOCKSHIFT); 400 } else { 401 dn->dn_datablksz = 0; 402 dn->dn_datablkszsec = 0; 403 dn->dn_datablkshift = 0; 404 } 405 dn->dn_indblkshift = dnp->dn_indblkshift; 406 dn->dn_nlevels = dnp->dn_nlevels; 407 dn->dn_type = dnp->dn_type; 408 dn->dn_nblkptr = dnp->dn_nblkptr; 409 dn->dn_checksum = dnp->dn_checksum; 410 dn->dn_compress = dnp->dn_compress; 411 dn->dn_bonustype = dnp->dn_bonustype; 412 dn->dn_bonuslen = dnp->dn_bonuslen; 413 dn->dn_maxblkid = dnp->dn_maxblkid; 414 dn->dn_have_spill = ((dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) != 0); 415 dn->dn_id_flags = 0; 416 417 dmu_zfetch_init(&dn->dn_zfetch, dn); 418 419 ASSERT(DMU_OT_IS_VALID(dn->dn_phys->dn_type)); 420 421 mutex_enter(&os->os_lock); 422 list_insert_head(&os->os_dnodes, dn); 423 membar_producer(); 424 /* 425 * Everything else must be valid before assigning dn_objset makes the 426 * dnode eligible for dnode_move(). 427 */ 428 dn->dn_objset = os; 429 mutex_exit(&os->os_lock); 430 431 arc_space_consume(sizeof (dnode_t), ARC_SPACE_OTHER); 432 return (dn); 433 } 434 435 /* 436 * Caller must be holding the dnode handle, which is released upon return. 437 */ 438 static void 439 dnode_destroy(dnode_t *dn) 440 { 441 objset_t *os = dn->dn_objset; 442 443 ASSERT((dn->dn_id_flags & DN_ID_NEW_EXIST) == 0); 444 445 mutex_enter(&os->os_lock); 446 POINTER_INVALIDATE(&dn->dn_objset); 447 list_remove(&os->os_dnodes, dn); 448 mutex_exit(&os->os_lock); 449 450 /* the dnode can no longer move, so we can release the handle */ 451 zrl_remove(&dn->dn_handle->dnh_zrlock); 452 453 dn->dn_allocated_txg = 0; 454 dn->dn_free_txg = 0; 455 dn->dn_assigned_txg = 0; 456 457 dn->dn_dirtyctx = 0; 458 if (dn->dn_dirtyctx_firstset != NULL) { 459 kmem_free(dn->dn_dirtyctx_firstset, 1); 460 dn->dn_dirtyctx_firstset = NULL; 461 } 462 if (dn->dn_bonus != NULL) { 463 mutex_enter(&dn->dn_bonus->db_mtx); 464 dbuf_evict(dn->dn_bonus); 465 dn->dn_bonus = NULL; 466 } 467 dn->dn_zio = NULL; 468 469 dn->dn_have_spill = B_FALSE; 470 dn->dn_oldused = 0; 471 dn->dn_oldflags = 0; 472 dn->dn_olduid = 0; 473 dn->dn_oldgid = 0; 474 dn->dn_newuid = 0; 475 dn->dn_newgid = 0; 476 dn->dn_id_flags = 0; 477 dn->dn_unlisted_l0_blkid = 0; 478 479 dmu_zfetch_rele(&dn->dn_zfetch); 480 kmem_cache_free(dnode_cache, dn); 481 arc_space_return(sizeof (dnode_t), ARC_SPACE_OTHER); 482 } 483 484 void 485 dnode_allocate(dnode_t *dn, dmu_object_type_t ot, int blocksize, int ibs, 486 dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx) 487 { 488 int i; 489 490 if (blocksize == 0) 491 blocksize = 1 << zfs_default_bs; 492 else if (blocksize > SPA_MAXBLOCKSIZE) 493 blocksize = SPA_MAXBLOCKSIZE; 494 else 495 blocksize = P2ROUNDUP(blocksize, SPA_MINBLOCKSIZE); 496 497 if (ibs == 0) 498 ibs = zfs_default_ibs; 499 500 ibs = MIN(MAX(ibs, DN_MIN_INDBLKSHIFT), DN_MAX_INDBLKSHIFT); 501 502 dprintf("os=%p obj=%llu txg=%llu blocksize=%d ibs=%d\n", dn->dn_objset, 503 dn->dn_object, tx->tx_txg, blocksize, ibs); 504 505 ASSERT(dn->dn_type == DMU_OT_NONE); 506 ASSERT(bcmp(dn->dn_phys, &dnode_phys_zero, sizeof (dnode_phys_t)) == 0); 507 ASSERT(dn->dn_phys->dn_type == DMU_OT_NONE); 508 ASSERT(ot != DMU_OT_NONE); 509 ASSERT(DMU_OT_IS_VALID(ot)); 510 ASSERT((bonustype == DMU_OT_NONE && bonuslen == 0) || 511 (bonustype == DMU_OT_SA && bonuslen == 0) || 512 (bonustype != DMU_OT_NONE && bonuslen != 0)); 513 ASSERT(DMU_OT_IS_VALID(bonustype)); 514 ASSERT3U(bonuslen, <=, DN_MAX_BONUSLEN); 515 ASSERT(dn->dn_type == DMU_OT_NONE); 516 ASSERT0(dn->dn_maxblkid); 517 ASSERT0(dn->dn_allocated_txg); 518 ASSERT0(dn->dn_assigned_txg); 519 ASSERT(refcount_is_zero(&dn->dn_tx_holds)); 520 ASSERT3U(refcount_count(&dn->dn_holds), <=, 1); 521 ASSERT3P(list_head(&dn->dn_dbufs), ==, NULL); 522 523 for (i = 0; i < TXG_SIZE; i++) { 524 ASSERT0(dn->dn_next_nblkptr[i]); 525 ASSERT0(dn->dn_next_nlevels[i]); 526 ASSERT0(dn->dn_next_indblkshift[i]); 527 ASSERT0(dn->dn_next_bonuslen[i]); 528 ASSERT0(dn->dn_next_bonustype[i]); 529 ASSERT0(dn->dn_rm_spillblk[i]); 530 ASSERT0(dn->dn_next_blksz[i]); 531 ASSERT(!list_link_active(&dn->dn_dirty_link[i])); 532 ASSERT3P(list_head(&dn->dn_dirty_records[i]), ==, NULL); 533 ASSERT0(avl_numnodes(&dn->dn_ranges[i])); 534 } 535 536 dn->dn_type = ot; 537 dnode_setdblksz(dn, blocksize); 538 dn->dn_indblkshift = ibs; 539 dn->dn_nlevels = 1; 540 if (bonustype == DMU_OT_SA) /* Maximize bonus space for SA */ 541 dn->dn_nblkptr = 1; 542 else 543 dn->dn_nblkptr = 1 + 544 ((DN_MAX_BONUSLEN - bonuslen) >> SPA_BLKPTRSHIFT); 545 dn->dn_bonustype = bonustype; 546 dn->dn_bonuslen = bonuslen; 547 dn->dn_checksum = ZIO_CHECKSUM_INHERIT; 548 dn->dn_compress = ZIO_COMPRESS_INHERIT; 549 dn->dn_dirtyctx = 0; 550 551 dn->dn_free_txg = 0; 552 if (dn->dn_dirtyctx_firstset) { 553 kmem_free(dn->dn_dirtyctx_firstset, 1); 554 dn->dn_dirtyctx_firstset = NULL; 555 } 556 557 dn->dn_allocated_txg = tx->tx_txg; 558 dn->dn_id_flags = 0; 559 560 dnode_setdirty(dn, tx); 561 dn->dn_next_indblkshift[tx->tx_txg & TXG_MASK] = ibs; 562 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = dn->dn_bonuslen; 563 dn->dn_next_bonustype[tx->tx_txg & TXG_MASK] = dn->dn_bonustype; 564 dn->dn_next_blksz[tx->tx_txg & TXG_MASK] = dn->dn_datablksz; 565 } 566 567 void 568 dnode_reallocate(dnode_t *dn, dmu_object_type_t ot, int blocksize, 569 dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx) 570 { 571 int nblkptr; 572 573 ASSERT3U(blocksize, >=, SPA_MINBLOCKSIZE); 574 ASSERT3U(blocksize, <=, SPA_MAXBLOCKSIZE); 575 ASSERT0(blocksize % SPA_MINBLOCKSIZE); 576 ASSERT(dn->dn_object != DMU_META_DNODE_OBJECT || dmu_tx_private_ok(tx)); 577 ASSERT(tx->tx_txg != 0); 578 ASSERT((bonustype == DMU_OT_NONE && bonuslen == 0) || 579 (bonustype != DMU_OT_NONE && bonuslen != 0) || 580 (bonustype == DMU_OT_SA && bonuslen == 0)); 581 ASSERT(DMU_OT_IS_VALID(bonustype)); 582 ASSERT3U(bonuslen, <=, DN_MAX_BONUSLEN); 583 584 /* clean up any unreferenced dbufs */ 585 dnode_evict_dbufs(dn); 586 587 dn->dn_id_flags = 0; 588 589 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 590 dnode_setdirty(dn, tx); 591 if (dn->dn_datablksz != blocksize) { 592 /* change blocksize */ 593 ASSERT(dn->dn_maxblkid == 0 && 594 (BP_IS_HOLE(&dn->dn_phys->dn_blkptr[0]) || 595 dnode_block_freed(dn, 0))); 596 dnode_setdblksz(dn, blocksize); 597 dn->dn_next_blksz[tx->tx_txg&TXG_MASK] = blocksize; 598 } 599 if (dn->dn_bonuslen != bonuslen) 600 dn->dn_next_bonuslen[tx->tx_txg&TXG_MASK] = bonuslen; 601 602 if (bonustype == DMU_OT_SA) /* Maximize bonus space for SA */ 603 nblkptr = 1; 604 else 605 nblkptr = 1 + ((DN_MAX_BONUSLEN - bonuslen) >> SPA_BLKPTRSHIFT); 606 if (dn->dn_bonustype != bonustype) 607 dn->dn_next_bonustype[tx->tx_txg&TXG_MASK] = bonustype; 608 if (dn->dn_nblkptr != nblkptr) 609 dn->dn_next_nblkptr[tx->tx_txg&TXG_MASK] = nblkptr; 610 if (dn->dn_phys->dn_flags & DNODE_FLAG_SPILL_BLKPTR) { 611 dbuf_rm_spill(dn, tx); 612 dnode_rm_spill(dn, tx); 613 } 614 rw_exit(&dn->dn_struct_rwlock); 615 616 /* change type */ 617 dn->dn_type = ot; 618 619 /* change bonus size and type */ 620 mutex_enter(&dn->dn_mtx); 621 dn->dn_bonustype = bonustype; 622 dn->dn_bonuslen = bonuslen; 623 dn->dn_nblkptr = nblkptr; 624 dn->dn_checksum = ZIO_CHECKSUM_INHERIT; 625 dn->dn_compress = ZIO_COMPRESS_INHERIT; 626 ASSERT3U(dn->dn_nblkptr, <=, DN_MAX_NBLKPTR); 627 628 /* fix up the bonus db_size */ 629 if (dn->dn_bonus) { 630 dn->dn_bonus->db.db_size = 631 DN_MAX_BONUSLEN - (dn->dn_nblkptr-1) * sizeof (blkptr_t); 632 ASSERT(dn->dn_bonuslen <= dn->dn_bonus->db.db_size); 633 } 634 635 dn->dn_allocated_txg = tx->tx_txg; 636 mutex_exit(&dn->dn_mtx); 637 } 638 639 #ifdef DNODE_STATS 640 static struct { 641 uint64_t dms_dnode_invalid; 642 uint64_t dms_dnode_recheck1; 643 uint64_t dms_dnode_recheck2; 644 uint64_t dms_dnode_special; 645 uint64_t dms_dnode_handle; 646 uint64_t dms_dnode_rwlock; 647 uint64_t dms_dnode_active; 648 } dnode_move_stats; 649 #endif /* DNODE_STATS */ 650 651 static void 652 dnode_move_impl(dnode_t *odn, dnode_t *ndn) 653 { 654 int i; 655 656 ASSERT(!RW_LOCK_HELD(&odn->dn_struct_rwlock)); 657 ASSERT(MUTEX_NOT_HELD(&odn->dn_mtx)); 658 ASSERT(MUTEX_NOT_HELD(&odn->dn_dbufs_mtx)); 659 ASSERT(!RW_LOCK_HELD(&odn->dn_zfetch.zf_rwlock)); 660 661 /* Copy fields. */ 662 ndn->dn_objset = odn->dn_objset; 663 ndn->dn_object = odn->dn_object; 664 ndn->dn_dbuf = odn->dn_dbuf; 665 ndn->dn_handle = odn->dn_handle; 666 ndn->dn_phys = odn->dn_phys; 667 ndn->dn_type = odn->dn_type; 668 ndn->dn_bonuslen = odn->dn_bonuslen; 669 ndn->dn_bonustype = odn->dn_bonustype; 670 ndn->dn_nblkptr = odn->dn_nblkptr; 671 ndn->dn_checksum = odn->dn_checksum; 672 ndn->dn_compress = odn->dn_compress; 673 ndn->dn_nlevels = odn->dn_nlevels; 674 ndn->dn_indblkshift = odn->dn_indblkshift; 675 ndn->dn_datablkshift = odn->dn_datablkshift; 676 ndn->dn_datablkszsec = odn->dn_datablkszsec; 677 ndn->dn_datablksz = odn->dn_datablksz; 678 ndn->dn_maxblkid = odn->dn_maxblkid; 679 bcopy(&odn->dn_next_nblkptr[0], &ndn->dn_next_nblkptr[0], 680 sizeof (odn->dn_next_nblkptr)); 681 bcopy(&odn->dn_next_nlevels[0], &ndn->dn_next_nlevels[0], 682 sizeof (odn->dn_next_nlevels)); 683 bcopy(&odn->dn_next_indblkshift[0], &ndn->dn_next_indblkshift[0], 684 sizeof (odn->dn_next_indblkshift)); 685 bcopy(&odn->dn_next_bonustype[0], &ndn->dn_next_bonustype[0], 686 sizeof (odn->dn_next_bonustype)); 687 bcopy(&odn->dn_rm_spillblk[0], &ndn->dn_rm_spillblk[0], 688 sizeof (odn->dn_rm_spillblk)); 689 bcopy(&odn->dn_next_bonuslen[0], &ndn->dn_next_bonuslen[0], 690 sizeof (odn->dn_next_bonuslen)); 691 bcopy(&odn->dn_next_blksz[0], &ndn->dn_next_blksz[0], 692 sizeof (odn->dn_next_blksz)); 693 for (i = 0; i < TXG_SIZE; i++) { 694 list_move_tail(&ndn->dn_dirty_records[i], 695 &odn->dn_dirty_records[i]); 696 } 697 bcopy(&odn->dn_ranges[0], &ndn->dn_ranges[0], sizeof (odn->dn_ranges)); 698 ndn->dn_allocated_txg = odn->dn_allocated_txg; 699 ndn->dn_free_txg = odn->dn_free_txg; 700 ndn->dn_assigned_txg = odn->dn_assigned_txg; 701 ndn->dn_dirtyctx = odn->dn_dirtyctx; 702 ndn->dn_dirtyctx_firstset = odn->dn_dirtyctx_firstset; 703 ASSERT(refcount_count(&odn->dn_tx_holds) == 0); 704 refcount_transfer(&ndn->dn_holds, &odn->dn_holds); 705 ASSERT(list_is_empty(&ndn->dn_dbufs)); 706 list_move_tail(&ndn->dn_dbufs, &odn->dn_dbufs); 707 ndn->dn_dbufs_count = odn->dn_dbufs_count; 708 ndn->dn_unlisted_l0_blkid = odn->dn_unlisted_l0_blkid; 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_unlisted_l0_blkid = 0; 744 odn->dn_bonus = NULL; 745 odn->dn_zfetch.zf_dnode = NULL; 746 747 /* 748 * Set the low bit of the objset pointer to ensure that dnode_move() 749 * recognizes the dnode as invalid in any subsequent callback. 750 */ 751 POINTER_INVALIDATE(&odn->dn_objset); 752 753 /* 754 * Satisfy the destructor. 755 */ 756 for (i = 0; i < TXG_SIZE; i++) { 757 list_create(&odn->dn_dirty_records[i], 758 sizeof (dbuf_dirty_record_t), 759 offsetof(dbuf_dirty_record_t, dr_dirty_node)); 760 odn->dn_ranges[i].avl_root = NULL; 761 odn->dn_ranges[i].avl_numnodes = 0; 762 odn->dn_next_nlevels[i] = 0; 763 odn->dn_next_indblkshift[i] = 0; 764 odn->dn_next_bonustype[i] = 0; 765 odn->dn_rm_spillblk[i] = 0; 766 odn->dn_next_bonuslen[i] = 0; 767 odn->dn_next_blksz[i] = 0; 768 } 769 odn->dn_allocated_txg = 0; 770 odn->dn_free_txg = 0; 771 odn->dn_assigned_txg = 0; 772 odn->dn_dirtyctx = 0; 773 odn->dn_dirtyctx_firstset = NULL; 774 odn->dn_have_spill = B_FALSE; 775 odn->dn_zio = NULL; 776 odn->dn_oldused = 0; 777 odn->dn_oldflags = 0; 778 odn->dn_olduid = 0; 779 odn->dn_oldgid = 0; 780 odn->dn_newuid = 0; 781 odn->dn_newgid = 0; 782 odn->dn_id_flags = 0; 783 784 /* 785 * Mark the dnode. 786 */ 787 ndn->dn_moved = 1; 788 odn->dn_moved = (uint8_t)-1; 789 } 790 791 #ifdef _KERNEL 792 /*ARGSUSED*/ 793 static kmem_cbrc_t 794 dnode_move(void *buf, void *newbuf, size_t size, void *arg) 795 { 796 dnode_t *odn = buf, *ndn = newbuf; 797 objset_t *os; 798 int64_t refcount; 799 uint32_t dbufs; 800 801 /* 802 * The dnode is on the objset's list of known dnodes if the objset 803 * pointer is valid. We set the low bit of the objset pointer when 804 * freeing the dnode to invalidate it, and the memory patterns written 805 * by kmem (baddcafe and deadbeef) set at least one of the two low bits. 806 * A newly created dnode sets the objset pointer last of all to indicate 807 * that the dnode is known and in a valid state to be moved by this 808 * function. 809 */ 810 os = odn->dn_objset; 811 if (!POINTER_IS_VALID(os)) { 812 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_invalid); 813 return (KMEM_CBRC_DONT_KNOW); 814 } 815 816 /* 817 * Ensure that the objset does not go away during the move. 818 */ 819 rw_enter(&os_lock, RW_WRITER); 820 if (os != odn->dn_objset) { 821 rw_exit(&os_lock); 822 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_recheck1); 823 return (KMEM_CBRC_DONT_KNOW); 824 } 825 826 /* 827 * If the dnode is still valid, then so is the objset. We know that no 828 * valid objset can be freed while we hold os_lock, so we can safely 829 * ensure that the objset remains in use. 830 */ 831 mutex_enter(&os->os_lock); 832 833 /* 834 * Recheck the objset pointer in case the dnode was removed just before 835 * acquiring the lock. 836 */ 837 if (os != odn->dn_objset) { 838 mutex_exit(&os->os_lock); 839 rw_exit(&os_lock); 840 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_recheck2); 841 return (KMEM_CBRC_DONT_KNOW); 842 } 843 844 /* 845 * At this point we know that as long as we hold os->os_lock, the dnode 846 * cannot be freed and fields within the dnode can be safely accessed. 847 * The objset listing this dnode cannot go away as long as this dnode is 848 * on its list. 849 */ 850 rw_exit(&os_lock); 851 if (DMU_OBJECT_IS_SPECIAL(odn->dn_object)) { 852 mutex_exit(&os->os_lock); 853 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_special); 854 return (KMEM_CBRC_NO); 855 } 856 ASSERT(odn->dn_dbuf != NULL); /* only "special" dnodes have no parent */ 857 858 /* 859 * Lock the dnode handle to prevent the dnode from obtaining any new 860 * holds. This also prevents the descendant dbufs and the bonus dbuf 861 * from accessing the dnode, so that we can discount their holds. The 862 * handle is safe to access because we know that while the dnode cannot 863 * go away, neither can its handle. Once we hold dnh_zrlock, we can 864 * safely move any dnode referenced only by dbufs. 865 */ 866 if (!zrl_tryenter(&odn->dn_handle->dnh_zrlock)) { 867 mutex_exit(&os->os_lock); 868 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_handle); 869 return (KMEM_CBRC_LATER); 870 } 871 872 /* 873 * Ensure a consistent view of the dnode's holds and the dnode's dbufs. 874 * We need to guarantee that there is a hold for every dbuf in order to 875 * determine whether the dnode is actively referenced. Falsely matching 876 * a dbuf to an active hold would lead to an unsafe move. It's possible 877 * that a thread already having an active dnode hold is about to add a 878 * dbuf, and we can't compare hold and dbuf counts while the add is in 879 * progress. 880 */ 881 if (!rw_tryenter(&odn->dn_struct_rwlock, RW_WRITER)) { 882 zrl_exit(&odn->dn_handle->dnh_zrlock); 883 mutex_exit(&os->os_lock); 884 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_rwlock); 885 return (KMEM_CBRC_LATER); 886 } 887 888 /* 889 * A dbuf may be removed (evicted) without an active dnode hold. In that 890 * case, the dbuf count is decremented under the handle lock before the 891 * dbuf's hold is released. This order ensures that if we count the hold 892 * after the dbuf is removed but before its hold is released, we will 893 * treat the unmatched hold as active and exit safely. If we count the 894 * hold before the dbuf is removed, the hold is discounted, and the 895 * removal is blocked until the move completes. 896 */ 897 refcount = refcount_count(&odn->dn_holds); 898 ASSERT(refcount >= 0); 899 dbufs = odn->dn_dbufs_count; 900 901 /* We can't have more dbufs than dnode holds. */ 902 ASSERT3U(dbufs, <=, refcount); 903 DTRACE_PROBE3(dnode__move, dnode_t *, odn, int64_t, refcount, 904 uint32_t, dbufs); 905 906 if (refcount > dbufs) { 907 rw_exit(&odn->dn_struct_rwlock); 908 zrl_exit(&odn->dn_handle->dnh_zrlock); 909 mutex_exit(&os->os_lock); 910 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_active); 911 return (KMEM_CBRC_LATER); 912 } 913 914 rw_exit(&odn->dn_struct_rwlock); 915 916 /* 917 * At this point we know that anyone with a hold on the dnode is not 918 * actively referencing it. The dnode is known and in a valid state to 919 * move. We're holding the locks needed to execute the critical section. 920 */ 921 dnode_move_impl(odn, ndn); 922 923 list_link_replace(&odn->dn_link, &ndn->dn_link); 924 /* If the dnode was safe to move, the refcount cannot have changed. */ 925 ASSERT(refcount == refcount_count(&ndn->dn_holds)); 926 ASSERT(dbufs == ndn->dn_dbufs_count); 927 zrl_exit(&ndn->dn_handle->dnh_zrlock); /* handle has moved */ 928 mutex_exit(&os->os_lock); 929 930 return (KMEM_CBRC_YES); 931 } 932 #endif /* _KERNEL */ 933 934 void 935 dnode_special_close(dnode_handle_t *dnh) 936 { 937 dnode_t *dn = dnh->dnh_dnode; 938 939 /* 940 * Wait for final references to the dnode to clear. This can 941 * only happen if the arc is asyncronously evicting state that 942 * has a hold on this dnode while we are trying to evict this 943 * dnode. 944 */ 945 while (refcount_count(&dn->dn_holds) > 0) 946 delay(1); 947 zrl_add(&dnh->dnh_zrlock); 948 dnode_destroy(dn); /* implicit zrl_remove() */ 949 zrl_destroy(&dnh->dnh_zrlock); 950 dnh->dnh_dnode = NULL; 951 } 952 953 dnode_t * 954 dnode_special_open(objset_t *os, dnode_phys_t *dnp, uint64_t object, 955 dnode_handle_t *dnh) 956 { 957 dnode_t *dn = dnode_create(os, dnp, NULL, object, dnh); 958 dnh->dnh_dnode = dn; 959 zrl_init(&dnh->dnh_zrlock); 960 DNODE_VERIFY(dn); 961 return (dn); 962 } 963 964 static void 965 dnode_buf_pageout(dmu_buf_t *db, void *arg) 966 { 967 dnode_children_t *children_dnodes = arg; 968 int i; 969 int epb = db->db_size >> DNODE_SHIFT; 970 971 ASSERT(epb == children_dnodes->dnc_count); 972 973 for (i = 0; i < epb; i++) { 974 dnode_handle_t *dnh = &children_dnodes->dnc_children[i]; 975 dnode_t *dn; 976 977 /* 978 * The dnode handle lock guards against the dnode moving to 979 * another valid address, so there is no need here to guard 980 * against changes to or from NULL. 981 */ 982 if (dnh->dnh_dnode == NULL) { 983 zrl_destroy(&dnh->dnh_zrlock); 984 continue; 985 } 986 987 zrl_add(&dnh->dnh_zrlock); 988 dn = dnh->dnh_dnode; 989 /* 990 * If there are holds on this dnode, then there should 991 * be holds on the dnode's containing dbuf as well; thus 992 * it wouldn't be eligible for eviction and this function 993 * would not have been called. 994 */ 995 ASSERT(refcount_is_zero(&dn->dn_holds)); 996 ASSERT(refcount_is_zero(&dn->dn_tx_holds)); 997 998 dnode_destroy(dn); /* implicit zrl_remove() */ 999 zrl_destroy(&dnh->dnh_zrlock); 1000 dnh->dnh_dnode = NULL; 1001 } 1002 kmem_free(children_dnodes, sizeof (dnode_children_t) + 1003 (epb - 1) * sizeof (dnode_handle_t)); 1004 } 1005 1006 /* 1007 * errors: 1008 * EINVAL - invalid object number. 1009 * EIO - i/o error. 1010 * succeeds even for free dnodes. 1011 */ 1012 int 1013 dnode_hold_impl(objset_t *os, uint64_t object, int flag, 1014 void *tag, dnode_t **dnp) 1015 { 1016 int epb, idx, err; 1017 int drop_struct_lock = FALSE; 1018 int type; 1019 uint64_t blk; 1020 dnode_t *mdn, *dn; 1021 dmu_buf_impl_t *db; 1022 dnode_children_t *children_dnodes; 1023 dnode_handle_t *dnh; 1024 1025 /* 1026 * If you are holding the spa config lock as writer, you shouldn't 1027 * be asking the DMU to do *anything* unless it's the root pool 1028 * which may require us to read from the root filesystem while 1029 * holding some (not all) of the locks as writer. 1030 */ 1031 ASSERT(spa_config_held(os->os_spa, SCL_ALL, RW_WRITER) == 0 || 1032 (spa_is_root(os->os_spa) && 1033 spa_config_held(os->os_spa, SCL_STATE, RW_WRITER))); 1034 1035 if (object == DMU_USERUSED_OBJECT || object == DMU_GROUPUSED_OBJECT) { 1036 dn = (object == DMU_USERUSED_OBJECT) ? 1037 DMU_USERUSED_DNODE(os) : DMU_GROUPUSED_DNODE(os); 1038 if (dn == NULL) 1039 return (SET_ERROR(ENOENT)); 1040 type = dn->dn_type; 1041 if ((flag & DNODE_MUST_BE_ALLOCATED) && type == DMU_OT_NONE) 1042 return (SET_ERROR(ENOENT)); 1043 if ((flag & DNODE_MUST_BE_FREE) && type != DMU_OT_NONE) 1044 return (SET_ERROR(EEXIST)); 1045 DNODE_VERIFY(dn); 1046 (void) refcount_add(&dn->dn_holds, tag); 1047 *dnp = dn; 1048 return (0); 1049 } 1050 1051 if (object == 0 || object >= DN_MAX_OBJECT) 1052 return (SET_ERROR(EINVAL)); 1053 1054 mdn = DMU_META_DNODE(os); 1055 ASSERT(mdn->dn_object == DMU_META_DNODE_OBJECT); 1056 1057 DNODE_VERIFY(mdn); 1058 1059 if (!RW_WRITE_HELD(&mdn->dn_struct_rwlock)) { 1060 rw_enter(&mdn->dn_struct_rwlock, RW_READER); 1061 drop_struct_lock = TRUE; 1062 } 1063 1064 blk = dbuf_whichblock(mdn, object * sizeof (dnode_phys_t)); 1065 1066 db = dbuf_hold(mdn, blk, FTAG); 1067 if (drop_struct_lock) 1068 rw_exit(&mdn->dn_struct_rwlock); 1069 if (db == NULL) 1070 return (SET_ERROR(EIO)); 1071 err = dbuf_read(db, NULL, DB_RF_CANFAIL); 1072 if (err) { 1073 dbuf_rele(db, FTAG); 1074 return (err); 1075 } 1076 1077 ASSERT3U(db->db.db_size, >=, 1<<DNODE_SHIFT); 1078 epb = db->db.db_size >> DNODE_SHIFT; 1079 1080 idx = object & (epb-1); 1081 1082 ASSERT(DB_DNODE(db)->dn_type == DMU_OT_DNODE); 1083 children_dnodes = dmu_buf_get_user(&db->db); 1084 if (children_dnodes == NULL) { 1085 int i; 1086 dnode_children_t *winner; 1087 children_dnodes = kmem_alloc(sizeof (dnode_children_t) + 1088 (epb - 1) * sizeof (dnode_handle_t), KM_SLEEP); 1089 children_dnodes->dnc_count = epb; 1090 dnh = &children_dnodes->dnc_children[0]; 1091 for (i = 0; i < epb; i++) { 1092 zrl_init(&dnh[i].dnh_zrlock); 1093 dnh[i].dnh_dnode = NULL; 1094 } 1095 if (winner = dmu_buf_set_user(&db->db, children_dnodes, NULL, 1096 dnode_buf_pageout)) { 1097 kmem_free(children_dnodes, sizeof (dnode_children_t) + 1098 (epb - 1) * sizeof (dnode_handle_t)); 1099 children_dnodes = winner; 1100 } 1101 } 1102 ASSERT(children_dnodes->dnc_count == epb); 1103 1104 dnh = &children_dnodes->dnc_children[idx]; 1105 zrl_add(&dnh->dnh_zrlock); 1106 if ((dn = dnh->dnh_dnode) == NULL) { 1107 dnode_phys_t *phys = (dnode_phys_t *)db->db.db_data+idx; 1108 dnode_t *winner; 1109 1110 dn = dnode_create(os, phys, db, object, dnh); 1111 winner = atomic_cas_ptr(&dnh->dnh_dnode, NULL, dn); 1112 if (winner != NULL) { 1113 zrl_add(&dnh->dnh_zrlock); 1114 dnode_destroy(dn); /* implicit zrl_remove() */ 1115 dn = winner; 1116 } 1117 } 1118 1119 mutex_enter(&dn->dn_mtx); 1120 type = dn->dn_type; 1121 if (dn->dn_free_txg || 1122 ((flag & DNODE_MUST_BE_ALLOCATED) && type == DMU_OT_NONE) || 1123 ((flag & DNODE_MUST_BE_FREE) && 1124 (type != DMU_OT_NONE || !refcount_is_zero(&dn->dn_holds)))) { 1125 mutex_exit(&dn->dn_mtx); 1126 zrl_remove(&dnh->dnh_zrlock); 1127 dbuf_rele(db, FTAG); 1128 return (type == DMU_OT_NONE ? ENOENT : EEXIST); 1129 } 1130 mutex_exit(&dn->dn_mtx); 1131 1132 if (refcount_add(&dn->dn_holds, tag) == 1) 1133 dbuf_add_ref(db, dnh); 1134 /* Now we can rely on the hold to prevent the dnode from moving. */ 1135 zrl_remove(&dnh->dnh_zrlock); 1136 1137 DNODE_VERIFY(dn); 1138 ASSERT3P(dn->dn_dbuf, ==, db); 1139 ASSERT3U(dn->dn_object, ==, object); 1140 dbuf_rele(db, FTAG); 1141 1142 *dnp = dn; 1143 return (0); 1144 } 1145 1146 /* 1147 * Return held dnode if the object is allocated, NULL if not. 1148 */ 1149 int 1150 dnode_hold(objset_t *os, uint64_t object, void *tag, dnode_t **dnp) 1151 { 1152 return (dnode_hold_impl(os, object, DNODE_MUST_BE_ALLOCATED, tag, dnp)); 1153 } 1154 1155 /* 1156 * Can only add a reference if there is already at least one 1157 * reference on the dnode. Returns FALSE if unable to add a 1158 * new reference. 1159 */ 1160 boolean_t 1161 dnode_add_ref(dnode_t *dn, void *tag) 1162 { 1163 mutex_enter(&dn->dn_mtx); 1164 if (refcount_is_zero(&dn->dn_holds)) { 1165 mutex_exit(&dn->dn_mtx); 1166 return (FALSE); 1167 } 1168 VERIFY(1 < refcount_add(&dn->dn_holds, tag)); 1169 mutex_exit(&dn->dn_mtx); 1170 return (TRUE); 1171 } 1172 1173 void 1174 dnode_rele(dnode_t *dn, void *tag) 1175 { 1176 uint64_t refs; 1177 /* Get while the hold prevents the dnode from moving. */ 1178 dmu_buf_impl_t *db = dn->dn_dbuf; 1179 dnode_handle_t *dnh = dn->dn_handle; 1180 1181 mutex_enter(&dn->dn_mtx); 1182 refs = refcount_remove(&dn->dn_holds, tag); 1183 mutex_exit(&dn->dn_mtx); 1184 1185 /* 1186 * It's unsafe to release the last hold on a dnode by dnode_rele() or 1187 * indirectly by dbuf_rele() while relying on the dnode handle to 1188 * prevent the dnode from moving, since releasing the last hold could 1189 * result in the dnode's parent dbuf evicting its dnode handles. For 1190 * that reason anyone calling dnode_rele() or dbuf_rele() without some 1191 * other direct or indirect hold on the dnode must first drop the dnode 1192 * handle. 1193 */ 1194 ASSERT(refs > 0 || dnh->dnh_zrlock.zr_owner != curthread); 1195 1196 /* NOTE: the DNODE_DNODE does not have a dn_dbuf */ 1197 if (refs == 0 && db != NULL) { 1198 /* 1199 * Another thread could add a hold to the dnode handle in 1200 * dnode_hold_impl() while holding the parent dbuf. Since the 1201 * hold on the parent dbuf prevents the handle from being 1202 * destroyed, the hold on the handle is OK. We can't yet assert 1203 * that the handle has zero references, but that will be 1204 * asserted anyway when the handle gets destroyed. 1205 */ 1206 dbuf_rele(db, dnh); 1207 } 1208 } 1209 1210 void 1211 dnode_setdirty(dnode_t *dn, dmu_tx_t *tx) 1212 { 1213 objset_t *os = dn->dn_objset; 1214 uint64_t txg = tx->tx_txg; 1215 1216 if (DMU_OBJECT_IS_SPECIAL(dn->dn_object)) { 1217 dsl_dataset_dirty(os->os_dsl_dataset, tx); 1218 return; 1219 } 1220 1221 DNODE_VERIFY(dn); 1222 1223 #ifdef ZFS_DEBUG 1224 mutex_enter(&dn->dn_mtx); 1225 ASSERT(dn->dn_phys->dn_type || dn->dn_allocated_txg); 1226 ASSERT(dn->dn_free_txg == 0 || dn->dn_free_txg >= txg); 1227 mutex_exit(&dn->dn_mtx); 1228 #endif 1229 1230 /* 1231 * Determine old uid/gid when necessary 1232 */ 1233 dmu_objset_userquota_get_ids(dn, B_TRUE, tx); 1234 1235 mutex_enter(&os->os_lock); 1236 1237 /* 1238 * If we are already marked dirty, we're done. 1239 */ 1240 if (list_link_active(&dn->dn_dirty_link[txg & TXG_MASK])) { 1241 mutex_exit(&os->os_lock); 1242 return; 1243 } 1244 1245 ASSERT(!refcount_is_zero(&dn->dn_holds) || list_head(&dn->dn_dbufs)); 1246 ASSERT(dn->dn_datablksz != 0); 1247 ASSERT0(dn->dn_next_bonuslen[txg&TXG_MASK]); 1248 ASSERT0(dn->dn_next_blksz[txg&TXG_MASK]); 1249 ASSERT0(dn->dn_next_bonustype[txg&TXG_MASK]); 1250 1251 dprintf_ds(os->os_dsl_dataset, "obj=%llu txg=%llu\n", 1252 dn->dn_object, txg); 1253 1254 if (dn->dn_free_txg > 0 && dn->dn_free_txg <= txg) { 1255 list_insert_tail(&os->os_free_dnodes[txg&TXG_MASK], dn); 1256 } else { 1257 list_insert_tail(&os->os_dirty_dnodes[txg&TXG_MASK], dn); 1258 } 1259 1260 mutex_exit(&os->os_lock); 1261 1262 /* 1263 * The dnode maintains a hold on its containing dbuf as 1264 * long as there are holds on it. Each instantiated child 1265 * dbuf maintains a hold on the dnode. When the last child 1266 * drops its hold, the dnode will drop its hold on the 1267 * containing dbuf. We add a "dirty hold" here so that the 1268 * dnode will hang around after we finish processing its 1269 * children. 1270 */ 1271 VERIFY(dnode_add_ref(dn, (void *)(uintptr_t)tx->tx_txg)); 1272 1273 (void) dbuf_dirty(dn->dn_dbuf, tx); 1274 1275 dsl_dataset_dirty(os->os_dsl_dataset, tx); 1276 } 1277 1278 void 1279 dnode_free(dnode_t *dn, dmu_tx_t *tx) 1280 { 1281 int txgoff = tx->tx_txg & TXG_MASK; 1282 1283 dprintf("dn=%p txg=%llu\n", dn, tx->tx_txg); 1284 1285 /* we should be the only holder... hopefully */ 1286 /* ASSERT3U(refcount_count(&dn->dn_holds), ==, 1); */ 1287 1288 mutex_enter(&dn->dn_mtx); 1289 if (dn->dn_type == DMU_OT_NONE || dn->dn_free_txg) { 1290 mutex_exit(&dn->dn_mtx); 1291 return; 1292 } 1293 dn->dn_free_txg = tx->tx_txg; 1294 mutex_exit(&dn->dn_mtx); 1295 1296 /* 1297 * If the dnode is already dirty, it needs to be moved from 1298 * the dirty list to the free list. 1299 */ 1300 mutex_enter(&dn->dn_objset->os_lock); 1301 if (list_link_active(&dn->dn_dirty_link[txgoff])) { 1302 list_remove(&dn->dn_objset->os_dirty_dnodes[txgoff], dn); 1303 list_insert_tail(&dn->dn_objset->os_free_dnodes[txgoff], dn); 1304 mutex_exit(&dn->dn_objset->os_lock); 1305 } else { 1306 mutex_exit(&dn->dn_objset->os_lock); 1307 dnode_setdirty(dn, tx); 1308 } 1309 } 1310 1311 /* 1312 * Try to change the block size for the indicated dnode. This can only 1313 * succeed if there are no blocks allocated or dirty beyond first block 1314 */ 1315 int 1316 dnode_set_blksz(dnode_t *dn, uint64_t size, int ibs, dmu_tx_t *tx) 1317 { 1318 dmu_buf_impl_t *db, *db_next; 1319 int err; 1320 1321 if (size == 0) 1322 size = SPA_MINBLOCKSIZE; 1323 if (size > SPA_MAXBLOCKSIZE) 1324 size = SPA_MAXBLOCKSIZE; 1325 else 1326 size = P2ROUNDUP(size, SPA_MINBLOCKSIZE); 1327 1328 if (ibs == dn->dn_indblkshift) 1329 ibs = 0; 1330 1331 if (size >> SPA_MINBLOCKSHIFT == dn->dn_datablkszsec && ibs == 0) 1332 return (0); 1333 1334 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 1335 1336 /* Check for any allocated blocks beyond the first */ 1337 if (dn->dn_maxblkid != 0) 1338 goto fail; 1339 1340 mutex_enter(&dn->dn_dbufs_mtx); 1341 for (db = list_head(&dn->dn_dbufs); db; db = db_next) { 1342 db_next = list_next(&dn->dn_dbufs, db); 1343 1344 if (db->db_blkid != 0 && db->db_blkid != DMU_BONUS_BLKID && 1345 db->db_blkid != DMU_SPILL_BLKID) { 1346 mutex_exit(&dn->dn_dbufs_mtx); 1347 goto fail; 1348 } 1349 } 1350 mutex_exit(&dn->dn_dbufs_mtx); 1351 1352 if (ibs && dn->dn_nlevels != 1) 1353 goto fail; 1354 1355 /* resize the old block */ 1356 err = dbuf_hold_impl(dn, 0, 0, TRUE, FTAG, &db); 1357 if (err == 0) 1358 dbuf_new_size(db, size, tx); 1359 else if (err != ENOENT) 1360 goto fail; 1361 1362 dnode_setdblksz(dn, size); 1363 dnode_setdirty(dn, tx); 1364 dn->dn_next_blksz[tx->tx_txg&TXG_MASK] = size; 1365 if (ibs) { 1366 dn->dn_indblkshift = ibs; 1367 dn->dn_next_indblkshift[tx->tx_txg&TXG_MASK] = ibs; 1368 } 1369 /* rele after we have fixed the blocksize in the dnode */ 1370 if (db) 1371 dbuf_rele(db, FTAG); 1372 1373 rw_exit(&dn->dn_struct_rwlock); 1374 return (0); 1375 1376 fail: 1377 rw_exit(&dn->dn_struct_rwlock); 1378 return (SET_ERROR(ENOTSUP)); 1379 } 1380 1381 /* read-holding callers must not rely on the lock being continuously held */ 1382 void 1383 dnode_new_blkid(dnode_t *dn, uint64_t blkid, dmu_tx_t *tx, boolean_t have_read) 1384 { 1385 uint64_t txgoff = tx->tx_txg & TXG_MASK; 1386 int epbs, new_nlevels; 1387 uint64_t sz; 1388 1389 ASSERT(blkid != DMU_BONUS_BLKID); 1390 1391 ASSERT(have_read ? 1392 RW_READ_HELD(&dn->dn_struct_rwlock) : 1393 RW_WRITE_HELD(&dn->dn_struct_rwlock)); 1394 1395 /* 1396 * if we have a read-lock, check to see if we need to do any work 1397 * before upgrading to a write-lock. 1398 */ 1399 if (have_read) { 1400 if (blkid <= dn->dn_maxblkid) 1401 return; 1402 1403 if (!rw_tryupgrade(&dn->dn_struct_rwlock)) { 1404 rw_exit(&dn->dn_struct_rwlock); 1405 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 1406 } 1407 } 1408 1409 if (blkid <= dn->dn_maxblkid) 1410 goto out; 1411 1412 dn->dn_maxblkid = blkid; 1413 1414 /* 1415 * Compute the number of levels necessary to support the new maxblkid. 1416 */ 1417 new_nlevels = 1; 1418 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT; 1419 for (sz = dn->dn_nblkptr; 1420 sz <= blkid && sz >= dn->dn_nblkptr; sz <<= epbs) 1421 new_nlevels++; 1422 1423 if (new_nlevels > dn->dn_nlevels) { 1424 int old_nlevels = dn->dn_nlevels; 1425 dmu_buf_impl_t *db; 1426 list_t *list; 1427 dbuf_dirty_record_t *new, *dr, *dr_next; 1428 1429 dn->dn_nlevels = new_nlevels; 1430 1431 ASSERT3U(new_nlevels, >, dn->dn_next_nlevels[txgoff]); 1432 dn->dn_next_nlevels[txgoff] = new_nlevels; 1433 1434 /* dirty the left indirects */ 1435 db = dbuf_hold_level(dn, old_nlevels, 0, FTAG); 1436 ASSERT(db != NULL); 1437 new = dbuf_dirty(db, tx); 1438 dbuf_rele(db, FTAG); 1439 1440 /* transfer the dirty records to the new indirect */ 1441 mutex_enter(&dn->dn_mtx); 1442 mutex_enter(&new->dt.di.dr_mtx); 1443 list = &dn->dn_dirty_records[txgoff]; 1444 for (dr = list_head(list); dr; dr = dr_next) { 1445 dr_next = list_next(&dn->dn_dirty_records[txgoff], dr); 1446 if (dr->dr_dbuf->db_level != new_nlevels-1 && 1447 dr->dr_dbuf->db_blkid != DMU_BONUS_BLKID && 1448 dr->dr_dbuf->db_blkid != DMU_SPILL_BLKID) { 1449 ASSERT(dr->dr_dbuf->db_level == old_nlevels-1); 1450 list_remove(&dn->dn_dirty_records[txgoff], dr); 1451 list_insert_tail(&new->dt.di.dr_children, dr); 1452 dr->dr_parent = new; 1453 } 1454 } 1455 mutex_exit(&new->dt.di.dr_mtx); 1456 mutex_exit(&dn->dn_mtx); 1457 } 1458 1459 out: 1460 if (have_read) 1461 rw_downgrade(&dn->dn_struct_rwlock); 1462 } 1463 1464 void 1465 dnode_clear_range(dnode_t *dn, uint64_t blkid, uint64_t nblks, dmu_tx_t *tx) 1466 { 1467 avl_tree_t *tree = &dn->dn_ranges[tx->tx_txg&TXG_MASK]; 1468 avl_index_t where; 1469 free_range_t *rp; 1470 free_range_t rp_tofind; 1471 uint64_t endblk = blkid + nblks; 1472 1473 ASSERT(MUTEX_HELD(&dn->dn_mtx)); 1474 ASSERT(nblks <= UINT64_MAX - blkid); /* no overflow */ 1475 1476 dprintf_dnode(dn, "blkid=%llu nblks=%llu txg=%llu\n", 1477 blkid, nblks, tx->tx_txg); 1478 rp_tofind.fr_blkid = blkid; 1479 rp = avl_find(tree, &rp_tofind, &where); 1480 if (rp == NULL) 1481 rp = avl_nearest(tree, where, AVL_BEFORE); 1482 if (rp == NULL) 1483 rp = avl_nearest(tree, where, AVL_AFTER); 1484 1485 while (rp && (rp->fr_blkid <= blkid + nblks)) { 1486 uint64_t fr_endblk = rp->fr_blkid + rp->fr_nblks; 1487 free_range_t *nrp = AVL_NEXT(tree, rp); 1488 1489 if (blkid <= rp->fr_blkid && endblk >= fr_endblk) { 1490 /* clear this entire range */ 1491 avl_remove(tree, rp); 1492 kmem_free(rp, sizeof (free_range_t)); 1493 } else if (blkid <= rp->fr_blkid && 1494 endblk > rp->fr_blkid && endblk < fr_endblk) { 1495 /* clear the beginning of this range */ 1496 rp->fr_blkid = endblk; 1497 rp->fr_nblks = fr_endblk - endblk; 1498 } else if (blkid > rp->fr_blkid && blkid < fr_endblk && 1499 endblk >= fr_endblk) { 1500 /* clear the end of this range */ 1501 rp->fr_nblks = blkid - rp->fr_blkid; 1502 } else if (blkid > rp->fr_blkid && endblk < fr_endblk) { 1503 /* clear a chunk out of this range */ 1504 free_range_t *new_rp = 1505 kmem_alloc(sizeof (free_range_t), KM_SLEEP); 1506 1507 new_rp->fr_blkid = endblk; 1508 new_rp->fr_nblks = fr_endblk - endblk; 1509 avl_insert_here(tree, new_rp, rp, AVL_AFTER); 1510 rp->fr_nblks = blkid - rp->fr_blkid; 1511 } 1512 /* there may be no overlap */ 1513 rp = nrp; 1514 } 1515 } 1516 1517 void 1518 dnode_free_range(dnode_t *dn, uint64_t off, uint64_t len, dmu_tx_t *tx) 1519 { 1520 dmu_buf_impl_t *db; 1521 uint64_t blkoff, blkid, nblks; 1522 int blksz, blkshift, head, tail; 1523 int trunc = FALSE; 1524 int epbs; 1525 1526 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 1527 blksz = dn->dn_datablksz; 1528 blkshift = dn->dn_datablkshift; 1529 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT; 1530 1531 if (len == DMU_OBJECT_END) { 1532 len = UINT64_MAX - off; 1533 trunc = TRUE; 1534 } 1535 1536 /* 1537 * First, block align the region to free: 1538 */ 1539 if (ISP2(blksz)) { 1540 head = P2NPHASE(off, blksz); 1541 blkoff = P2PHASE(off, blksz); 1542 if ((off >> blkshift) > dn->dn_maxblkid) 1543 goto out; 1544 } else { 1545 ASSERT(dn->dn_maxblkid == 0); 1546 if (off == 0 && len >= blksz) { 1547 /* 1548 * Freeing the whole block; fast-track this request. 1549 * Note that we won't dirty any indirect blocks, 1550 * which is fine because we will be freeing the entire 1551 * file and thus all indirect blocks will be freed 1552 * by free_children(). 1553 */ 1554 blkid = 0; 1555 nblks = 1; 1556 goto done; 1557 } else if (off >= blksz) { 1558 /* Freeing past end-of-data */ 1559 goto out; 1560 } else { 1561 /* Freeing part of the block. */ 1562 head = blksz - off; 1563 ASSERT3U(head, >, 0); 1564 } 1565 blkoff = off; 1566 } 1567 /* zero out any partial block data at the start of the range */ 1568 if (head) { 1569 ASSERT3U(blkoff + head, ==, blksz); 1570 if (len < head) 1571 head = len; 1572 if (dbuf_hold_impl(dn, 0, dbuf_whichblock(dn, off), TRUE, 1573 FTAG, &db) == 0) { 1574 caddr_t data; 1575 1576 /* don't dirty if it isn't on disk and isn't dirty */ 1577 if (db->db_last_dirty || 1578 (db->db_blkptr && !BP_IS_HOLE(db->db_blkptr))) { 1579 rw_exit(&dn->dn_struct_rwlock); 1580 dmu_buf_will_dirty(&db->db, tx); 1581 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 1582 data = db->db.db_data; 1583 bzero(data + blkoff, head); 1584 } 1585 dbuf_rele(db, FTAG); 1586 } 1587 off += head; 1588 len -= head; 1589 } 1590 1591 /* If the range was less than one block, we're done */ 1592 if (len == 0) 1593 goto out; 1594 1595 /* If the remaining range is past end of file, we're done */ 1596 if ((off >> blkshift) > dn->dn_maxblkid) 1597 goto out; 1598 1599 ASSERT(ISP2(blksz)); 1600 if (trunc) 1601 tail = 0; 1602 else 1603 tail = P2PHASE(len, blksz); 1604 1605 ASSERT0(P2PHASE(off, blksz)); 1606 /* zero out any partial block data at the end of the range */ 1607 if (tail) { 1608 if (len < tail) 1609 tail = len; 1610 if (dbuf_hold_impl(dn, 0, dbuf_whichblock(dn, off+len), 1611 TRUE, FTAG, &db) == 0) { 1612 /* don't dirty if not on disk and not dirty */ 1613 if (db->db_last_dirty || 1614 (db->db_blkptr && !BP_IS_HOLE(db->db_blkptr))) { 1615 rw_exit(&dn->dn_struct_rwlock); 1616 dmu_buf_will_dirty(&db->db, tx); 1617 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 1618 bzero(db->db.db_data, tail); 1619 } 1620 dbuf_rele(db, FTAG); 1621 } 1622 len -= tail; 1623 } 1624 1625 /* If the range did not include a full block, we are done */ 1626 if (len == 0) 1627 goto out; 1628 1629 ASSERT(IS_P2ALIGNED(off, blksz)); 1630 ASSERT(trunc || IS_P2ALIGNED(len, blksz)); 1631 blkid = off >> blkshift; 1632 nblks = len >> blkshift; 1633 if (trunc) 1634 nblks += 1; 1635 1636 /* 1637 * Dirty the first and last indirect blocks, as they (and/or their 1638 * parents) will need to be written out if they were only 1639 * partially freed. Interior indirect blocks will be themselves freed, 1640 * by free_children(), so they need not be dirtied. Note that these 1641 * interior blocks have already been prefetched by dmu_tx_hold_free(). 1642 */ 1643 if (dn->dn_nlevels > 1) { 1644 uint64_t first, last; 1645 1646 first = blkid >> epbs; 1647 if (db = dbuf_hold_level(dn, 1, first, FTAG)) { 1648 dmu_buf_will_dirty(&db->db, tx); 1649 dbuf_rele(db, FTAG); 1650 } 1651 if (trunc) 1652 last = dn->dn_maxblkid >> epbs; 1653 else 1654 last = (blkid + nblks - 1) >> epbs; 1655 if (last > first && (db = dbuf_hold_level(dn, 1, last, FTAG))) { 1656 dmu_buf_will_dirty(&db->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 1689 rw_exit(&dn->dn_struct_rwlock); 1690 } 1691 1692 static boolean_t 1693 dnode_spill_freed(dnode_t *dn) 1694 { 1695 int i; 1696 1697 mutex_enter(&dn->dn_mtx); 1698 for (i = 0; i < TXG_SIZE; i++) { 1699 if (dn->dn_rm_spillblk[i] == DN_KILL_SPILLBLK) 1700 break; 1701 } 1702 mutex_exit(&dn->dn_mtx); 1703 return (i < TXG_SIZE); 1704 } 1705 1706 /* return TRUE if this blkid was freed in a recent txg, or FALSE if it wasn't */ 1707 uint64_t 1708 dnode_block_freed(dnode_t *dn, uint64_t blkid) 1709 { 1710 free_range_t range_tofind; 1711 void *dp = spa_get_dsl(dn->dn_objset->os_spa); 1712 int i; 1713 1714 if (blkid == DMU_BONUS_BLKID) 1715 return (FALSE); 1716 1717 /* 1718 * If we're in the process of opening the pool, dp will not be 1719 * set yet, but there shouldn't be anything dirty. 1720 */ 1721 if (dp == NULL) 1722 return (FALSE); 1723 1724 if (dn->dn_free_txg) 1725 return (TRUE); 1726 1727 if (blkid == DMU_SPILL_BLKID) 1728 return (dnode_spill_freed(dn)); 1729 1730 range_tofind.fr_blkid = blkid; 1731 mutex_enter(&dn->dn_mtx); 1732 for (i = 0; i < TXG_SIZE; i++) { 1733 free_range_t *range_found; 1734 avl_index_t idx; 1735 1736 range_found = avl_find(&dn->dn_ranges[i], &range_tofind, &idx); 1737 if (range_found) { 1738 ASSERT(range_found->fr_nblks > 0); 1739 break; 1740 } 1741 range_found = avl_nearest(&dn->dn_ranges[i], idx, AVL_BEFORE); 1742 if (range_found && 1743 range_found->fr_blkid + range_found->fr_nblks > blkid) 1744 break; 1745 } 1746 mutex_exit(&dn->dn_mtx); 1747 return (i < TXG_SIZE); 1748 } 1749 1750 /* call from syncing context when we actually write/free space for this dnode */ 1751 void 1752 dnode_diduse_space(dnode_t *dn, int64_t delta) 1753 { 1754 uint64_t space; 1755 dprintf_dnode(dn, "dn=%p dnp=%p used=%llu delta=%lld\n", 1756 dn, dn->dn_phys, 1757 (u_longlong_t)dn->dn_phys->dn_used, 1758 (longlong_t)delta); 1759 1760 mutex_enter(&dn->dn_mtx); 1761 space = DN_USED_BYTES(dn->dn_phys); 1762 if (delta > 0) { 1763 ASSERT3U(space + delta, >=, space); /* no overflow */ 1764 } else { 1765 ASSERT3U(space, >=, -delta); /* no underflow */ 1766 } 1767 space += delta; 1768 if (spa_version(dn->dn_objset->os_spa) < SPA_VERSION_DNODE_BYTES) { 1769 ASSERT((dn->dn_phys->dn_flags & DNODE_FLAG_USED_BYTES) == 0); 1770 ASSERT0(P2PHASE(space, 1<<DEV_BSHIFT)); 1771 dn->dn_phys->dn_used = space >> DEV_BSHIFT; 1772 } else { 1773 dn->dn_phys->dn_used = space; 1774 dn->dn_phys->dn_flags |= DNODE_FLAG_USED_BYTES; 1775 } 1776 mutex_exit(&dn->dn_mtx); 1777 } 1778 1779 /* 1780 * Call when we think we're going to write/free space in open context to track 1781 * the amount of memory in use by the currently open txg. 1782 */ 1783 void 1784 dnode_willuse_space(dnode_t *dn, int64_t space, dmu_tx_t *tx) 1785 { 1786 objset_t *os = dn->dn_objset; 1787 dsl_dataset_t *ds = os->os_dsl_dataset; 1788 int64_t aspace = spa_get_asize(os->os_spa, space); 1789 1790 if (ds != NULL) { 1791 dsl_dir_willuse_space(ds->ds_dir, aspace, tx); 1792 dsl_pool_dirty_space(dmu_tx_pool(tx), space, tx); 1793 } 1794 1795 dmu_tx_willuse_space(tx, aspace); 1796 } 1797 1798 /* 1799 * Scans a block at the indicated "level" looking for a hole or data, 1800 * depending on 'flags'. 1801 * 1802 * If level > 0, then we are scanning an indirect block looking at its 1803 * pointers. If level == 0, then we are looking at a block of dnodes. 1804 * 1805 * If we don't find what we are looking for in the block, we return ESRCH. 1806 * Otherwise, return with *offset pointing to the beginning (if searching 1807 * forwards) or end (if searching backwards) of the range covered by the 1808 * block pointer we matched on (or dnode). 1809 * 1810 * The basic search algorithm used below by dnode_next_offset() is to 1811 * use this function to search up the block tree (widen the search) until 1812 * we find something (i.e., we don't return ESRCH) and then search back 1813 * down the tree (narrow the search) until we reach our original search 1814 * level. 1815 */ 1816 static int 1817 dnode_next_offset_level(dnode_t *dn, int flags, uint64_t *offset, 1818 int lvl, uint64_t blkfill, uint64_t txg) 1819 { 1820 dmu_buf_impl_t *db = NULL; 1821 void *data = NULL; 1822 uint64_t epbs = dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT; 1823 uint64_t epb = 1ULL << epbs; 1824 uint64_t minfill, maxfill; 1825 boolean_t hole; 1826 int i, inc, error, span; 1827 1828 dprintf("probing object %llu offset %llx level %d of %u\n", 1829 dn->dn_object, *offset, lvl, dn->dn_phys->dn_nlevels); 1830 1831 hole = ((flags & DNODE_FIND_HOLE) != 0); 1832 inc = (flags & DNODE_FIND_BACKWARDS) ? -1 : 1; 1833 ASSERT(txg == 0 || !hole); 1834 1835 if (lvl == dn->dn_phys->dn_nlevels) { 1836 error = 0; 1837 epb = dn->dn_phys->dn_nblkptr; 1838 data = dn->dn_phys->dn_blkptr; 1839 } else { 1840 uint64_t blkid = dbuf_whichblock(dn, *offset) >> (epbs * lvl); 1841 error = dbuf_hold_impl(dn, lvl, blkid, TRUE, FTAG, &db); 1842 if (error) { 1843 if (error != ENOENT) 1844 return (error); 1845 if (hole) 1846 return (0); 1847 /* 1848 * This can only happen when we are searching up 1849 * the block tree for data. We don't really need to 1850 * adjust the offset, as we will just end up looking 1851 * at the pointer to this block in its parent, and its 1852 * going to be unallocated, so we will skip over it. 1853 */ 1854 return (SET_ERROR(ESRCH)); 1855 } 1856 error = dbuf_read(db, NULL, DB_RF_CANFAIL | DB_RF_HAVESTRUCT); 1857 if (error) { 1858 dbuf_rele(db, FTAG); 1859 return (error); 1860 } 1861 data = db->db.db_data; 1862 } 1863 1864 1865 if (db != NULL && txg != 0 && (db->db_blkptr == NULL || 1866 db->db_blkptr->blk_birth <= txg || 1867 BP_IS_HOLE(db->db_blkptr))) { 1868 /* 1869 * This can only happen when we are searching up the tree 1870 * and these conditions mean that we need to keep climbing. 1871 */ 1872 error = SET_ERROR(ESRCH); 1873 } else if (lvl == 0) { 1874 dnode_phys_t *dnp = data; 1875 span = DNODE_SHIFT; 1876 ASSERT(dn->dn_type == DMU_OT_DNODE); 1877 1878 for (i = (*offset >> span) & (blkfill - 1); 1879 i >= 0 && i < blkfill; i += inc) { 1880 if ((dnp[i].dn_type == DMU_OT_NONE) == hole) 1881 break; 1882 *offset += (1ULL << span) * inc; 1883 } 1884 if (i < 0 || i == blkfill) 1885 error = SET_ERROR(ESRCH); 1886 } else { 1887 blkptr_t *bp = data; 1888 uint64_t start = *offset; 1889 span = (lvl - 1) * epbs + dn->dn_datablkshift; 1890 minfill = 0; 1891 maxfill = blkfill << ((lvl - 1) * epbs); 1892 1893 if (hole) 1894 maxfill--; 1895 else 1896 minfill++; 1897 1898 *offset = *offset >> span; 1899 for (i = BF64_GET(*offset, 0, epbs); 1900 i >= 0 && i < epb; i += inc) { 1901 if (bp[i].blk_fill >= minfill && 1902 bp[i].blk_fill <= maxfill && 1903 (hole || bp[i].blk_birth > txg)) 1904 break; 1905 if (inc > 0 || *offset > 0) 1906 *offset += inc; 1907 } 1908 *offset = *offset << span; 1909 if (inc < 0) { 1910 /* traversing backwards; position offset at the end */ 1911 ASSERT3U(*offset, <=, start); 1912 *offset = MIN(*offset + (1ULL << span) - 1, start); 1913 } else if (*offset < start) { 1914 *offset = start; 1915 } 1916 if (i < 0 || i >= epb) 1917 error = SET_ERROR(ESRCH); 1918 } 1919 1920 if (db) 1921 dbuf_rele(db, FTAG); 1922 1923 return (error); 1924 } 1925 1926 /* 1927 * Find the next hole, data, or sparse region at or after *offset. 1928 * The value 'blkfill' tells us how many items we expect to find 1929 * in an L0 data block; this value is 1 for normal objects, 1930 * DNODES_PER_BLOCK for the meta dnode, and some fraction of 1931 * DNODES_PER_BLOCK when searching for sparse regions thereof. 1932 * 1933 * Examples: 1934 * 1935 * dnode_next_offset(dn, flags, offset, 1, 1, 0); 1936 * Finds the next/previous hole/data in a file. 1937 * Used in dmu_offset_next(). 1938 * 1939 * dnode_next_offset(mdn, flags, offset, 0, DNODES_PER_BLOCK, txg); 1940 * Finds the next free/allocated dnode an objset's meta-dnode. 1941 * Only finds objects that have new contents since txg (ie. 1942 * bonus buffer changes and content removal are ignored). 1943 * Used in dmu_object_next(). 1944 * 1945 * dnode_next_offset(mdn, DNODE_FIND_HOLE, offset, 2, DNODES_PER_BLOCK >> 2, 0); 1946 * Finds the next L2 meta-dnode bp that's at most 1/4 full. 1947 * Used in dmu_object_alloc(). 1948 */ 1949 int 1950 dnode_next_offset(dnode_t *dn, int flags, uint64_t *offset, 1951 int minlvl, uint64_t blkfill, uint64_t txg) 1952 { 1953 uint64_t initial_offset = *offset; 1954 int lvl, maxlvl; 1955 int error = 0; 1956 1957 if (!(flags & DNODE_FIND_HAVELOCK)) 1958 rw_enter(&dn->dn_struct_rwlock, RW_READER); 1959 1960 if (dn->dn_phys->dn_nlevels == 0) { 1961 error = SET_ERROR(ESRCH); 1962 goto out; 1963 } 1964 1965 if (dn->dn_datablkshift == 0) { 1966 if (*offset < dn->dn_datablksz) { 1967 if (flags & DNODE_FIND_HOLE) 1968 *offset = dn->dn_datablksz; 1969 } else { 1970 error = SET_ERROR(ESRCH); 1971 } 1972 goto out; 1973 } 1974 1975 maxlvl = dn->dn_phys->dn_nlevels; 1976 1977 for (lvl = minlvl; lvl <= maxlvl; lvl++) { 1978 error = dnode_next_offset_level(dn, 1979 flags, offset, lvl, blkfill, txg); 1980 if (error != ESRCH) 1981 break; 1982 } 1983 1984 while (error == 0 && --lvl >= minlvl) { 1985 error = dnode_next_offset_level(dn, 1986 flags, offset, lvl, blkfill, txg); 1987 } 1988 1989 if (error == 0 && (flags & DNODE_FIND_BACKWARDS ? 1990 initial_offset < *offset : initial_offset > *offset)) 1991 error = SET_ERROR(ESRCH); 1992 out: 1993 if (!(flags & DNODE_FIND_HAVELOCK)) 1994 rw_exit(&dn->dn_struct_rwlock); 1995 1996 return (error); 1997 } 1998