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, 2014 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 #include <sys/range_tree.h> 39 40 static kmem_cache_t *dnode_cache; 41 /* 42 * Define DNODE_STATS to turn on statistic gathering. By default, it is only 43 * turned on when DEBUG is also defined. 44 */ 45 #ifdef DEBUG 46 #define DNODE_STATS 47 #endif /* DEBUG */ 48 49 #ifdef DNODE_STATS 50 #define DNODE_STAT_ADD(stat) ((stat)++) 51 #else 52 #define DNODE_STAT_ADD(stat) /* nothing */ 53 #endif /* DNODE_STATS */ 54 55 static dnode_phys_t dnode_phys_zero; 56 57 int zfs_default_bs = SPA_MINBLOCKSHIFT; 58 int zfs_default_ibs = DN_MAX_INDBLKSHIFT; 59 60 static kmem_cbrc_t dnode_move(void *, void *, size_t, void *); 61 62 /* ARGSUSED */ 63 static int 64 dnode_cons(void *arg, void *unused, int kmflag) 65 { 66 dnode_t *dn = arg; 67 int i; 68 69 rw_init(&dn->dn_struct_rwlock, NULL, RW_DEFAULT, NULL); 70 mutex_init(&dn->dn_mtx, NULL, MUTEX_DEFAULT, NULL); 71 mutex_init(&dn->dn_dbufs_mtx, NULL, MUTEX_DEFAULT, NULL); 72 cv_init(&dn->dn_notxholds, NULL, CV_DEFAULT, NULL); 73 74 /* 75 * Every dbuf has a reference, and dropping a tracked reference is 76 * O(number of references), so don't track dn_holds. 77 */ 78 refcount_create_untracked(&dn->dn_holds); 79 refcount_create(&dn->dn_tx_holds); 80 list_link_init(&dn->dn_link); 81 82 bzero(&dn->dn_next_nblkptr[0], sizeof (dn->dn_next_nblkptr)); 83 bzero(&dn->dn_next_nlevels[0], sizeof (dn->dn_next_nlevels)); 84 bzero(&dn->dn_next_indblkshift[0], sizeof (dn->dn_next_indblkshift)); 85 bzero(&dn->dn_next_bonustype[0], sizeof (dn->dn_next_bonustype)); 86 bzero(&dn->dn_rm_spillblk[0], sizeof (dn->dn_rm_spillblk)); 87 bzero(&dn->dn_next_bonuslen[0], sizeof (dn->dn_next_bonuslen)); 88 bzero(&dn->dn_next_blksz[0], sizeof (dn->dn_next_blksz)); 89 90 for (i = 0; i < TXG_SIZE; i++) { 91 list_link_init(&dn->dn_dirty_link[i]); 92 dn->dn_free_ranges[i] = NULL; 93 list_create(&dn->dn_dirty_records[i], 94 sizeof (dbuf_dirty_record_t), 95 offsetof(dbuf_dirty_record_t, dr_dirty_node)); 96 } 97 98 dn->dn_allocated_txg = 0; 99 dn->dn_free_txg = 0; 100 dn->dn_assigned_txg = 0; 101 dn->dn_dirtyctx = 0; 102 dn->dn_dirtyctx_firstset = NULL; 103 dn->dn_bonus = NULL; 104 dn->dn_have_spill = B_FALSE; 105 dn->dn_zio = NULL; 106 dn->dn_oldused = 0; 107 dn->dn_oldflags = 0; 108 dn->dn_olduid = 0; 109 dn->dn_oldgid = 0; 110 dn->dn_newuid = 0; 111 dn->dn_newgid = 0; 112 dn->dn_id_flags = 0; 113 114 dn->dn_dbufs_count = 0; 115 dn->dn_unlisted_l0_blkid = 0; 116 list_create(&dn->dn_dbufs, sizeof (dmu_buf_impl_t), 117 offsetof(dmu_buf_impl_t, db_link)); 118 119 dn->dn_moved = 0; 120 return (0); 121 } 122 123 /* ARGSUSED */ 124 static void 125 dnode_dest(void *arg, void *unused) 126 { 127 int i; 128 dnode_t *dn = arg; 129 130 rw_destroy(&dn->dn_struct_rwlock); 131 mutex_destroy(&dn->dn_mtx); 132 mutex_destroy(&dn->dn_dbufs_mtx); 133 cv_destroy(&dn->dn_notxholds); 134 refcount_destroy(&dn->dn_holds); 135 refcount_destroy(&dn->dn_tx_holds); 136 ASSERT(!list_link_active(&dn->dn_link)); 137 138 for (i = 0; i < TXG_SIZE; i++) { 139 ASSERT(!list_link_active(&dn->dn_dirty_link[i])); 140 ASSERT3P(dn->dn_free_ranges[i], ==, NULL); 141 list_destroy(&dn->dn_dirty_records[i]); 142 ASSERT0(dn->dn_next_nblkptr[i]); 143 ASSERT0(dn->dn_next_nlevels[i]); 144 ASSERT0(dn->dn_next_indblkshift[i]); 145 ASSERT0(dn->dn_next_bonustype[i]); 146 ASSERT0(dn->dn_rm_spillblk[i]); 147 ASSERT0(dn->dn_next_bonuslen[i]); 148 ASSERT0(dn->dn_next_blksz[i]); 149 } 150 151 ASSERT0(dn->dn_allocated_txg); 152 ASSERT0(dn->dn_free_txg); 153 ASSERT0(dn->dn_assigned_txg); 154 ASSERT0(dn->dn_dirtyctx); 155 ASSERT3P(dn->dn_dirtyctx_firstset, ==, NULL); 156 ASSERT3P(dn->dn_bonus, ==, NULL); 157 ASSERT(!dn->dn_have_spill); 158 ASSERT3P(dn->dn_zio, ==, NULL); 159 ASSERT0(dn->dn_oldused); 160 ASSERT0(dn->dn_oldflags); 161 ASSERT0(dn->dn_olduid); 162 ASSERT0(dn->dn_oldgid); 163 ASSERT0(dn->dn_newuid); 164 ASSERT0(dn->dn_newgid); 165 ASSERT0(dn->dn_id_flags); 166 167 ASSERT0(dn->dn_dbufs_count); 168 ASSERT0(dn->dn_unlisted_l0_blkid); 169 list_destroy(&dn->dn_dbufs); 170 } 171 172 void 173 dnode_init(void) 174 { 175 ASSERT(dnode_cache == NULL); 176 dnode_cache = kmem_cache_create("dnode_t", 177 sizeof (dnode_t), 178 0, dnode_cons, dnode_dest, NULL, NULL, NULL, 0); 179 kmem_cache_set_move(dnode_cache, dnode_move); 180 } 181 182 void 183 dnode_fini(void) 184 { 185 kmem_cache_destroy(dnode_cache); 186 dnode_cache = NULL; 187 } 188 189 190 #ifdef ZFS_DEBUG 191 void 192 dnode_verify(dnode_t *dn) 193 { 194 int drop_struct_lock = FALSE; 195 196 ASSERT(dn->dn_phys); 197 ASSERT(dn->dn_objset); 198 ASSERT(dn->dn_handle->dnh_dnode == dn); 199 200 ASSERT(DMU_OT_IS_VALID(dn->dn_phys->dn_type)); 201 202 if (!(zfs_flags & ZFS_DEBUG_DNODE_VERIFY)) 203 return; 204 205 if (!RW_WRITE_HELD(&dn->dn_struct_rwlock)) { 206 rw_enter(&dn->dn_struct_rwlock, RW_READER); 207 drop_struct_lock = TRUE; 208 } 209 if (dn->dn_phys->dn_type != DMU_OT_NONE || dn->dn_allocated_txg != 0) { 210 int i; 211 ASSERT3U(dn->dn_indblkshift, >=, 0); 212 ASSERT3U(dn->dn_indblkshift, <=, SPA_MAXBLOCKSHIFT); 213 if (dn->dn_datablkshift) { 214 ASSERT3U(dn->dn_datablkshift, >=, SPA_MINBLOCKSHIFT); 215 ASSERT3U(dn->dn_datablkshift, <=, SPA_MAXBLOCKSHIFT); 216 ASSERT3U(1<<dn->dn_datablkshift, ==, dn->dn_datablksz); 217 } 218 ASSERT3U(dn->dn_nlevels, <=, 30); 219 ASSERT(DMU_OT_IS_VALID(dn->dn_type)); 220 ASSERT3U(dn->dn_nblkptr, >=, 1); 221 ASSERT3U(dn->dn_nblkptr, <=, DN_MAX_NBLKPTR); 222 ASSERT3U(dn->dn_bonuslen, <=, DN_MAX_BONUSLEN); 223 ASSERT3U(dn->dn_datablksz, ==, 224 dn->dn_datablkszsec << SPA_MINBLOCKSHIFT); 225 ASSERT3U(ISP2(dn->dn_datablksz), ==, dn->dn_datablkshift != 0); 226 ASSERT3U((dn->dn_nblkptr - 1) * sizeof (blkptr_t) + 227 dn->dn_bonuslen, <=, DN_MAX_BONUSLEN); 228 for (i = 0; i < TXG_SIZE; i++) { 229 ASSERT3U(dn->dn_next_nlevels[i], <=, dn->dn_nlevels); 230 } 231 } 232 if (dn->dn_phys->dn_type != DMU_OT_NONE) 233 ASSERT3U(dn->dn_phys->dn_nlevels, <=, dn->dn_nlevels); 234 ASSERT(DMU_OBJECT_IS_SPECIAL(dn->dn_object) || dn->dn_dbuf != NULL); 235 if (dn->dn_dbuf != NULL) { 236 ASSERT3P(dn->dn_phys, ==, 237 (dnode_phys_t *)dn->dn_dbuf->db.db_data + 238 (dn->dn_object % (dn->dn_dbuf->db.db_size >> DNODE_SHIFT))); 239 } 240 if (drop_struct_lock) 241 rw_exit(&dn->dn_struct_rwlock); 242 } 243 #endif 244 245 void 246 dnode_byteswap(dnode_phys_t *dnp) 247 { 248 uint64_t *buf64 = (void*)&dnp->dn_blkptr; 249 int i; 250 251 if (dnp->dn_type == DMU_OT_NONE) { 252 bzero(dnp, sizeof (dnode_phys_t)); 253 return; 254 } 255 256 dnp->dn_datablkszsec = BSWAP_16(dnp->dn_datablkszsec); 257 dnp->dn_bonuslen = BSWAP_16(dnp->dn_bonuslen); 258 dnp->dn_maxblkid = BSWAP_64(dnp->dn_maxblkid); 259 dnp->dn_used = BSWAP_64(dnp->dn_used); 260 261 /* 262 * dn_nblkptr is only one byte, so it's OK to read it in either 263 * byte order. We can't read dn_bouslen. 264 */ 265 ASSERT(dnp->dn_indblkshift <= SPA_MAXBLOCKSHIFT); 266 ASSERT(dnp->dn_nblkptr <= DN_MAX_NBLKPTR); 267 for (i = 0; i < dnp->dn_nblkptr * sizeof (blkptr_t)/8; i++) 268 buf64[i] = BSWAP_64(buf64[i]); 269 270 /* 271 * OK to check dn_bonuslen for zero, because it won't matter if 272 * we have the wrong byte order. This is necessary because the 273 * dnode dnode is smaller than a regular dnode. 274 */ 275 if (dnp->dn_bonuslen != 0) { 276 /* 277 * Note that the bonus length calculated here may be 278 * longer than the actual bonus buffer. This is because 279 * we always put the bonus buffer after the last block 280 * pointer (instead of packing it against the end of the 281 * dnode buffer). 282 */ 283 int off = (dnp->dn_nblkptr-1) * sizeof (blkptr_t); 284 size_t len = DN_MAX_BONUSLEN - off; 285 ASSERT(DMU_OT_IS_VALID(dnp->dn_bonustype)); 286 dmu_object_byteswap_t byteswap = 287 DMU_OT_BYTESWAP(dnp->dn_bonustype); 288 dmu_ot_byteswap[byteswap].ob_func(dnp->dn_bonus + off, len); 289 } 290 291 /* Swap SPILL block if we have one */ 292 if (dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) 293 byteswap_uint64_array(&dnp->dn_spill, sizeof (blkptr_t)); 294 295 } 296 297 void 298 dnode_buf_byteswap(void *vbuf, size_t size) 299 { 300 dnode_phys_t *buf = vbuf; 301 int i; 302 303 ASSERT3U(sizeof (dnode_phys_t), ==, (1<<DNODE_SHIFT)); 304 ASSERT((size & (sizeof (dnode_phys_t)-1)) == 0); 305 306 size >>= DNODE_SHIFT; 307 for (i = 0; i < size; i++) { 308 dnode_byteswap(buf); 309 buf++; 310 } 311 } 312 313 void 314 dnode_setbonuslen(dnode_t *dn, int newsize, dmu_tx_t *tx) 315 { 316 ASSERT3U(refcount_count(&dn->dn_holds), >=, 1); 317 318 dnode_setdirty(dn, tx); 319 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 320 ASSERT3U(newsize, <=, DN_MAX_BONUSLEN - 321 (dn->dn_nblkptr-1) * sizeof (blkptr_t)); 322 dn->dn_bonuslen = newsize; 323 if (newsize == 0) 324 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = DN_ZERO_BONUSLEN; 325 else 326 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = dn->dn_bonuslen; 327 rw_exit(&dn->dn_struct_rwlock); 328 } 329 330 void 331 dnode_setbonus_type(dnode_t *dn, dmu_object_type_t newtype, dmu_tx_t *tx) 332 { 333 ASSERT3U(refcount_count(&dn->dn_holds), >=, 1); 334 dnode_setdirty(dn, tx); 335 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 336 dn->dn_bonustype = newtype; 337 dn->dn_next_bonustype[tx->tx_txg & TXG_MASK] = dn->dn_bonustype; 338 rw_exit(&dn->dn_struct_rwlock); 339 } 340 341 void 342 dnode_rm_spill(dnode_t *dn, dmu_tx_t *tx) 343 { 344 ASSERT3U(refcount_count(&dn->dn_holds), >=, 1); 345 ASSERT(RW_WRITE_HELD(&dn->dn_struct_rwlock)); 346 dnode_setdirty(dn, tx); 347 dn->dn_rm_spillblk[tx->tx_txg&TXG_MASK] = DN_KILL_SPILLBLK; 348 dn->dn_have_spill = B_FALSE; 349 } 350 351 static void 352 dnode_setdblksz(dnode_t *dn, int size) 353 { 354 ASSERT0(P2PHASE(size, SPA_MINBLOCKSIZE)); 355 ASSERT3U(size, <=, SPA_MAXBLOCKSIZE); 356 ASSERT3U(size, >=, SPA_MINBLOCKSIZE); 357 ASSERT3U(size >> SPA_MINBLOCKSHIFT, <, 358 1<<(sizeof (dn->dn_phys->dn_datablkszsec) * 8)); 359 dn->dn_datablksz = size; 360 dn->dn_datablkszsec = size >> SPA_MINBLOCKSHIFT; 361 dn->dn_datablkshift = ISP2(size) ? highbit64(size - 1) : 0; 362 } 363 364 static dnode_t * 365 dnode_create(objset_t *os, dnode_phys_t *dnp, dmu_buf_impl_t *db, 366 uint64_t object, dnode_handle_t *dnh) 367 { 368 dnode_t *dn = kmem_cache_alloc(dnode_cache, KM_SLEEP); 369 370 ASSERT(!POINTER_IS_VALID(dn->dn_objset)); 371 dn->dn_moved = 0; 372 373 /* 374 * Defer setting dn_objset until the dnode is ready to be a candidate 375 * for the dnode_move() callback. 376 */ 377 dn->dn_object = object; 378 dn->dn_dbuf = db; 379 dn->dn_handle = dnh; 380 dn->dn_phys = dnp; 381 382 if (dnp->dn_datablkszsec) { 383 dnode_setdblksz(dn, dnp->dn_datablkszsec << SPA_MINBLOCKSHIFT); 384 } else { 385 dn->dn_datablksz = 0; 386 dn->dn_datablkszsec = 0; 387 dn->dn_datablkshift = 0; 388 } 389 dn->dn_indblkshift = dnp->dn_indblkshift; 390 dn->dn_nlevels = dnp->dn_nlevels; 391 dn->dn_type = dnp->dn_type; 392 dn->dn_nblkptr = dnp->dn_nblkptr; 393 dn->dn_checksum = dnp->dn_checksum; 394 dn->dn_compress = dnp->dn_compress; 395 dn->dn_bonustype = dnp->dn_bonustype; 396 dn->dn_bonuslen = dnp->dn_bonuslen; 397 dn->dn_maxblkid = dnp->dn_maxblkid; 398 dn->dn_have_spill = ((dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) != 0); 399 dn->dn_id_flags = 0; 400 401 dmu_zfetch_init(&dn->dn_zfetch, dn); 402 403 ASSERT(DMU_OT_IS_VALID(dn->dn_phys->dn_type)); 404 405 mutex_enter(&os->os_lock); 406 list_insert_head(&os->os_dnodes, dn); 407 membar_producer(); 408 /* 409 * Everything else must be valid before assigning dn_objset makes the 410 * dnode eligible for dnode_move(). 411 */ 412 dn->dn_objset = os; 413 mutex_exit(&os->os_lock); 414 415 arc_space_consume(sizeof (dnode_t), ARC_SPACE_OTHER); 416 return (dn); 417 } 418 419 /* 420 * Caller must be holding the dnode handle, which is released upon return. 421 */ 422 static void 423 dnode_destroy(dnode_t *dn) 424 { 425 objset_t *os = dn->dn_objset; 426 427 ASSERT((dn->dn_id_flags & DN_ID_NEW_EXIST) == 0); 428 429 mutex_enter(&os->os_lock); 430 POINTER_INVALIDATE(&dn->dn_objset); 431 list_remove(&os->os_dnodes, dn); 432 mutex_exit(&os->os_lock); 433 434 /* the dnode can no longer move, so we can release the handle */ 435 zrl_remove(&dn->dn_handle->dnh_zrlock); 436 437 dn->dn_allocated_txg = 0; 438 dn->dn_free_txg = 0; 439 dn->dn_assigned_txg = 0; 440 441 dn->dn_dirtyctx = 0; 442 if (dn->dn_dirtyctx_firstset != NULL) { 443 kmem_free(dn->dn_dirtyctx_firstset, 1); 444 dn->dn_dirtyctx_firstset = NULL; 445 } 446 if (dn->dn_bonus != NULL) { 447 mutex_enter(&dn->dn_bonus->db_mtx); 448 dbuf_evict(dn->dn_bonus); 449 dn->dn_bonus = NULL; 450 } 451 dn->dn_zio = NULL; 452 453 dn->dn_have_spill = B_FALSE; 454 dn->dn_oldused = 0; 455 dn->dn_oldflags = 0; 456 dn->dn_olduid = 0; 457 dn->dn_oldgid = 0; 458 dn->dn_newuid = 0; 459 dn->dn_newgid = 0; 460 dn->dn_id_flags = 0; 461 dn->dn_unlisted_l0_blkid = 0; 462 463 dmu_zfetch_rele(&dn->dn_zfetch); 464 kmem_cache_free(dnode_cache, dn); 465 arc_space_return(sizeof (dnode_t), ARC_SPACE_OTHER); 466 } 467 468 void 469 dnode_allocate(dnode_t *dn, dmu_object_type_t ot, int blocksize, int ibs, 470 dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx) 471 { 472 int i; 473 474 if (blocksize == 0) 475 blocksize = 1 << zfs_default_bs; 476 else if (blocksize > SPA_MAXBLOCKSIZE) 477 blocksize = SPA_MAXBLOCKSIZE; 478 else 479 blocksize = P2ROUNDUP(blocksize, SPA_MINBLOCKSIZE); 480 481 if (ibs == 0) 482 ibs = zfs_default_ibs; 483 484 ibs = MIN(MAX(ibs, DN_MIN_INDBLKSHIFT), DN_MAX_INDBLKSHIFT); 485 486 dprintf("os=%p obj=%llu txg=%llu blocksize=%d ibs=%d\n", dn->dn_objset, 487 dn->dn_object, tx->tx_txg, blocksize, ibs); 488 489 ASSERT(dn->dn_type == DMU_OT_NONE); 490 ASSERT(bcmp(dn->dn_phys, &dnode_phys_zero, sizeof (dnode_phys_t)) == 0); 491 ASSERT(dn->dn_phys->dn_type == DMU_OT_NONE); 492 ASSERT(ot != DMU_OT_NONE); 493 ASSERT(DMU_OT_IS_VALID(ot)); 494 ASSERT((bonustype == DMU_OT_NONE && bonuslen == 0) || 495 (bonustype == DMU_OT_SA && bonuslen == 0) || 496 (bonustype != DMU_OT_NONE && bonuslen != 0)); 497 ASSERT(DMU_OT_IS_VALID(bonustype)); 498 ASSERT3U(bonuslen, <=, DN_MAX_BONUSLEN); 499 ASSERT(dn->dn_type == DMU_OT_NONE); 500 ASSERT0(dn->dn_maxblkid); 501 ASSERT0(dn->dn_allocated_txg); 502 ASSERT0(dn->dn_assigned_txg); 503 ASSERT(refcount_is_zero(&dn->dn_tx_holds)); 504 ASSERT3U(refcount_count(&dn->dn_holds), <=, 1); 505 ASSERT3P(list_head(&dn->dn_dbufs), ==, NULL); 506 507 for (i = 0; i < TXG_SIZE; i++) { 508 ASSERT0(dn->dn_next_nblkptr[i]); 509 ASSERT0(dn->dn_next_nlevels[i]); 510 ASSERT0(dn->dn_next_indblkshift[i]); 511 ASSERT0(dn->dn_next_bonuslen[i]); 512 ASSERT0(dn->dn_next_bonustype[i]); 513 ASSERT0(dn->dn_rm_spillblk[i]); 514 ASSERT0(dn->dn_next_blksz[i]); 515 ASSERT(!list_link_active(&dn->dn_dirty_link[i])); 516 ASSERT3P(list_head(&dn->dn_dirty_records[i]), ==, NULL); 517 ASSERT3P(dn->dn_free_ranges[i], ==, NULL); 518 } 519 520 dn->dn_type = ot; 521 dnode_setdblksz(dn, blocksize); 522 dn->dn_indblkshift = ibs; 523 dn->dn_nlevels = 1; 524 if (bonustype == DMU_OT_SA) /* Maximize bonus space for SA */ 525 dn->dn_nblkptr = 1; 526 else 527 dn->dn_nblkptr = 1 + 528 ((DN_MAX_BONUSLEN - bonuslen) >> SPA_BLKPTRSHIFT); 529 dn->dn_bonustype = bonustype; 530 dn->dn_bonuslen = bonuslen; 531 dn->dn_checksum = ZIO_CHECKSUM_INHERIT; 532 dn->dn_compress = ZIO_COMPRESS_INHERIT; 533 dn->dn_dirtyctx = 0; 534 535 dn->dn_free_txg = 0; 536 if (dn->dn_dirtyctx_firstset) { 537 kmem_free(dn->dn_dirtyctx_firstset, 1); 538 dn->dn_dirtyctx_firstset = NULL; 539 } 540 541 dn->dn_allocated_txg = tx->tx_txg; 542 dn->dn_id_flags = 0; 543 544 dnode_setdirty(dn, tx); 545 dn->dn_next_indblkshift[tx->tx_txg & TXG_MASK] = ibs; 546 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = dn->dn_bonuslen; 547 dn->dn_next_bonustype[tx->tx_txg & TXG_MASK] = dn->dn_bonustype; 548 dn->dn_next_blksz[tx->tx_txg & TXG_MASK] = dn->dn_datablksz; 549 } 550 551 void 552 dnode_reallocate(dnode_t *dn, dmu_object_type_t ot, int blocksize, 553 dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx) 554 { 555 int nblkptr; 556 557 ASSERT3U(blocksize, >=, SPA_MINBLOCKSIZE); 558 ASSERT3U(blocksize, <=, SPA_MAXBLOCKSIZE); 559 ASSERT0(blocksize % SPA_MINBLOCKSIZE); 560 ASSERT(dn->dn_object != DMU_META_DNODE_OBJECT || dmu_tx_private_ok(tx)); 561 ASSERT(tx->tx_txg != 0); 562 ASSERT((bonustype == DMU_OT_NONE && bonuslen == 0) || 563 (bonustype != DMU_OT_NONE && bonuslen != 0) || 564 (bonustype == DMU_OT_SA && bonuslen == 0)); 565 ASSERT(DMU_OT_IS_VALID(bonustype)); 566 ASSERT3U(bonuslen, <=, DN_MAX_BONUSLEN); 567 568 /* clean up any unreferenced dbufs */ 569 dnode_evict_dbufs(dn); 570 571 dn->dn_id_flags = 0; 572 573 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 574 dnode_setdirty(dn, tx); 575 if (dn->dn_datablksz != blocksize) { 576 /* change blocksize */ 577 ASSERT(dn->dn_maxblkid == 0 && 578 (BP_IS_HOLE(&dn->dn_phys->dn_blkptr[0]) || 579 dnode_block_freed(dn, 0))); 580 dnode_setdblksz(dn, blocksize); 581 dn->dn_next_blksz[tx->tx_txg&TXG_MASK] = blocksize; 582 } 583 if (dn->dn_bonuslen != bonuslen) 584 dn->dn_next_bonuslen[tx->tx_txg&TXG_MASK] = bonuslen; 585 586 if (bonustype == DMU_OT_SA) /* Maximize bonus space for SA */ 587 nblkptr = 1; 588 else 589 nblkptr = 1 + ((DN_MAX_BONUSLEN - bonuslen) >> SPA_BLKPTRSHIFT); 590 if (dn->dn_bonustype != bonustype) 591 dn->dn_next_bonustype[tx->tx_txg&TXG_MASK] = bonustype; 592 if (dn->dn_nblkptr != nblkptr) 593 dn->dn_next_nblkptr[tx->tx_txg&TXG_MASK] = nblkptr; 594 if (dn->dn_phys->dn_flags & DNODE_FLAG_SPILL_BLKPTR) { 595 dbuf_rm_spill(dn, tx); 596 dnode_rm_spill(dn, tx); 597 } 598 rw_exit(&dn->dn_struct_rwlock); 599 600 /* change type */ 601 dn->dn_type = ot; 602 603 /* change bonus size and type */ 604 mutex_enter(&dn->dn_mtx); 605 dn->dn_bonustype = bonustype; 606 dn->dn_bonuslen = bonuslen; 607 dn->dn_nblkptr = nblkptr; 608 dn->dn_checksum = ZIO_CHECKSUM_INHERIT; 609 dn->dn_compress = ZIO_COMPRESS_INHERIT; 610 ASSERT3U(dn->dn_nblkptr, <=, DN_MAX_NBLKPTR); 611 612 /* fix up the bonus db_size */ 613 if (dn->dn_bonus) { 614 dn->dn_bonus->db.db_size = 615 DN_MAX_BONUSLEN - (dn->dn_nblkptr-1) * sizeof (blkptr_t); 616 ASSERT(dn->dn_bonuslen <= dn->dn_bonus->db.db_size); 617 } 618 619 dn->dn_allocated_txg = tx->tx_txg; 620 mutex_exit(&dn->dn_mtx); 621 } 622 623 #ifdef DNODE_STATS 624 static struct { 625 uint64_t dms_dnode_invalid; 626 uint64_t dms_dnode_recheck1; 627 uint64_t dms_dnode_recheck2; 628 uint64_t dms_dnode_special; 629 uint64_t dms_dnode_handle; 630 uint64_t dms_dnode_rwlock; 631 uint64_t dms_dnode_active; 632 } dnode_move_stats; 633 #endif /* DNODE_STATS */ 634 635 static void 636 dnode_move_impl(dnode_t *odn, dnode_t *ndn) 637 { 638 int i; 639 640 ASSERT(!RW_LOCK_HELD(&odn->dn_struct_rwlock)); 641 ASSERT(MUTEX_NOT_HELD(&odn->dn_mtx)); 642 ASSERT(MUTEX_NOT_HELD(&odn->dn_dbufs_mtx)); 643 ASSERT(!RW_LOCK_HELD(&odn->dn_zfetch.zf_rwlock)); 644 645 /* Copy fields. */ 646 ndn->dn_objset = odn->dn_objset; 647 ndn->dn_object = odn->dn_object; 648 ndn->dn_dbuf = odn->dn_dbuf; 649 ndn->dn_handle = odn->dn_handle; 650 ndn->dn_phys = odn->dn_phys; 651 ndn->dn_type = odn->dn_type; 652 ndn->dn_bonuslen = odn->dn_bonuslen; 653 ndn->dn_bonustype = odn->dn_bonustype; 654 ndn->dn_nblkptr = odn->dn_nblkptr; 655 ndn->dn_checksum = odn->dn_checksum; 656 ndn->dn_compress = odn->dn_compress; 657 ndn->dn_nlevels = odn->dn_nlevels; 658 ndn->dn_indblkshift = odn->dn_indblkshift; 659 ndn->dn_datablkshift = odn->dn_datablkshift; 660 ndn->dn_datablkszsec = odn->dn_datablkszsec; 661 ndn->dn_datablksz = odn->dn_datablksz; 662 ndn->dn_maxblkid = odn->dn_maxblkid; 663 bcopy(&odn->dn_next_nblkptr[0], &ndn->dn_next_nblkptr[0], 664 sizeof (odn->dn_next_nblkptr)); 665 bcopy(&odn->dn_next_nlevels[0], &ndn->dn_next_nlevels[0], 666 sizeof (odn->dn_next_nlevels)); 667 bcopy(&odn->dn_next_indblkshift[0], &ndn->dn_next_indblkshift[0], 668 sizeof (odn->dn_next_indblkshift)); 669 bcopy(&odn->dn_next_bonustype[0], &ndn->dn_next_bonustype[0], 670 sizeof (odn->dn_next_bonustype)); 671 bcopy(&odn->dn_rm_spillblk[0], &ndn->dn_rm_spillblk[0], 672 sizeof (odn->dn_rm_spillblk)); 673 bcopy(&odn->dn_next_bonuslen[0], &ndn->dn_next_bonuslen[0], 674 sizeof (odn->dn_next_bonuslen)); 675 bcopy(&odn->dn_next_blksz[0], &ndn->dn_next_blksz[0], 676 sizeof (odn->dn_next_blksz)); 677 for (i = 0; i < TXG_SIZE; i++) { 678 list_move_tail(&ndn->dn_dirty_records[i], 679 &odn->dn_dirty_records[i]); 680 } 681 bcopy(&odn->dn_free_ranges[0], &ndn->dn_free_ranges[0], 682 sizeof (odn->dn_free_ranges)); 683 ndn->dn_allocated_txg = odn->dn_allocated_txg; 684 ndn->dn_free_txg = odn->dn_free_txg; 685 ndn->dn_assigned_txg = odn->dn_assigned_txg; 686 ndn->dn_dirtyctx = odn->dn_dirtyctx; 687 ndn->dn_dirtyctx_firstset = odn->dn_dirtyctx_firstset; 688 ASSERT(refcount_count(&odn->dn_tx_holds) == 0); 689 refcount_transfer(&ndn->dn_holds, &odn->dn_holds); 690 ASSERT(list_is_empty(&ndn->dn_dbufs)); 691 list_move_tail(&ndn->dn_dbufs, &odn->dn_dbufs); 692 ndn->dn_dbufs_count = odn->dn_dbufs_count; 693 ndn->dn_unlisted_l0_blkid = odn->dn_unlisted_l0_blkid; 694 ndn->dn_bonus = odn->dn_bonus; 695 ndn->dn_have_spill = odn->dn_have_spill; 696 ndn->dn_zio = odn->dn_zio; 697 ndn->dn_oldused = odn->dn_oldused; 698 ndn->dn_oldflags = odn->dn_oldflags; 699 ndn->dn_olduid = odn->dn_olduid; 700 ndn->dn_oldgid = odn->dn_oldgid; 701 ndn->dn_newuid = odn->dn_newuid; 702 ndn->dn_newgid = odn->dn_newgid; 703 ndn->dn_id_flags = odn->dn_id_flags; 704 dmu_zfetch_init(&ndn->dn_zfetch, NULL); 705 list_move_tail(&ndn->dn_zfetch.zf_stream, &odn->dn_zfetch.zf_stream); 706 ndn->dn_zfetch.zf_dnode = odn->dn_zfetch.zf_dnode; 707 ndn->dn_zfetch.zf_stream_cnt = odn->dn_zfetch.zf_stream_cnt; 708 ndn->dn_zfetch.zf_alloc_fail = odn->dn_zfetch.zf_alloc_fail; 709 710 /* 711 * Update back pointers. Updating the handle fixes the back pointer of 712 * every descendant dbuf as well as the bonus dbuf. 713 */ 714 ASSERT(ndn->dn_handle->dnh_dnode == odn); 715 ndn->dn_handle->dnh_dnode = ndn; 716 if (ndn->dn_zfetch.zf_dnode == odn) { 717 ndn->dn_zfetch.zf_dnode = ndn; 718 } 719 720 /* 721 * Invalidate the original dnode by clearing all of its back pointers. 722 */ 723 odn->dn_dbuf = NULL; 724 odn->dn_handle = NULL; 725 list_create(&odn->dn_dbufs, sizeof (dmu_buf_impl_t), 726 offsetof(dmu_buf_impl_t, db_link)); 727 odn->dn_dbufs_count = 0; 728 odn->dn_unlisted_l0_blkid = 0; 729 odn->dn_bonus = NULL; 730 odn->dn_zfetch.zf_dnode = NULL; 731 732 /* 733 * Set the low bit of the objset pointer to ensure that dnode_move() 734 * recognizes the dnode as invalid in any subsequent callback. 735 */ 736 POINTER_INVALIDATE(&odn->dn_objset); 737 738 /* 739 * Satisfy the destructor. 740 */ 741 for (i = 0; i < TXG_SIZE; i++) { 742 list_create(&odn->dn_dirty_records[i], 743 sizeof (dbuf_dirty_record_t), 744 offsetof(dbuf_dirty_record_t, dr_dirty_node)); 745 odn->dn_free_ranges[i] = NULL; 746 odn->dn_next_nlevels[i] = 0; 747 odn->dn_next_indblkshift[i] = 0; 748 odn->dn_next_bonustype[i] = 0; 749 odn->dn_rm_spillblk[i] = 0; 750 odn->dn_next_bonuslen[i] = 0; 751 odn->dn_next_blksz[i] = 0; 752 } 753 odn->dn_allocated_txg = 0; 754 odn->dn_free_txg = 0; 755 odn->dn_assigned_txg = 0; 756 odn->dn_dirtyctx = 0; 757 odn->dn_dirtyctx_firstset = NULL; 758 odn->dn_have_spill = B_FALSE; 759 odn->dn_zio = NULL; 760 odn->dn_oldused = 0; 761 odn->dn_oldflags = 0; 762 odn->dn_olduid = 0; 763 odn->dn_oldgid = 0; 764 odn->dn_newuid = 0; 765 odn->dn_newgid = 0; 766 odn->dn_id_flags = 0; 767 768 /* 769 * Mark the dnode. 770 */ 771 ndn->dn_moved = 1; 772 odn->dn_moved = (uint8_t)-1; 773 } 774 775 #ifdef _KERNEL 776 /*ARGSUSED*/ 777 static kmem_cbrc_t 778 dnode_move(void *buf, void *newbuf, size_t size, void *arg) 779 { 780 dnode_t *odn = buf, *ndn = newbuf; 781 objset_t *os; 782 int64_t refcount; 783 uint32_t dbufs; 784 785 /* 786 * The dnode is on the objset's list of known dnodes if the objset 787 * pointer is valid. We set the low bit of the objset pointer when 788 * freeing the dnode to invalidate it, and the memory patterns written 789 * by kmem (baddcafe and deadbeef) set at least one of the two low bits. 790 * A newly created dnode sets the objset pointer last of all to indicate 791 * that the dnode is known and in a valid state to be moved by this 792 * function. 793 */ 794 os = odn->dn_objset; 795 if (!POINTER_IS_VALID(os)) { 796 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_invalid); 797 return (KMEM_CBRC_DONT_KNOW); 798 } 799 800 /* 801 * Ensure that the objset does not go away during the move. 802 */ 803 rw_enter(&os_lock, RW_WRITER); 804 if (os != odn->dn_objset) { 805 rw_exit(&os_lock); 806 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_recheck1); 807 return (KMEM_CBRC_DONT_KNOW); 808 } 809 810 /* 811 * If the dnode is still valid, then so is the objset. We know that no 812 * valid objset can be freed while we hold os_lock, so we can safely 813 * ensure that the objset remains in use. 814 */ 815 mutex_enter(&os->os_lock); 816 817 /* 818 * Recheck the objset pointer in case the dnode was removed just before 819 * acquiring the lock. 820 */ 821 if (os != odn->dn_objset) { 822 mutex_exit(&os->os_lock); 823 rw_exit(&os_lock); 824 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_recheck2); 825 return (KMEM_CBRC_DONT_KNOW); 826 } 827 828 /* 829 * At this point we know that as long as we hold os->os_lock, the dnode 830 * cannot be freed and fields within the dnode can be safely accessed. 831 * The objset listing this dnode cannot go away as long as this dnode is 832 * on its list. 833 */ 834 rw_exit(&os_lock); 835 if (DMU_OBJECT_IS_SPECIAL(odn->dn_object)) { 836 mutex_exit(&os->os_lock); 837 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_special); 838 return (KMEM_CBRC_NO); 839 } 840 ASSERT(odn->dn_dbuf != NULL); /* only "special" dnodes have no parent */ 841 842 /* 843 * Lock the dnode handle to prevent the dnode from obtaining any new 844 * holds. This also prevents the descendant dbufs and the bonus dbuf 845 * from accessing the dnode, so that we can discount their holds. The 846 * handle is safe to access because we know that while the dnode cannot 847 * go away, neither can its handle. Once we hold dnh_zrlock, we can 848 * safely move any dnode referenced only by dbufs. 849 */ 850 if (!zrl_tryenter(&odn->dn_handle->dnh_zrlock)) { 851 mutex_exit(&os->os_lock); 852 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_handle); 853 return (KMEM_CBRC_LATER); 854 } 855 856 /* 857 * Ensure a consistent view of the dnode's holds and the dnode's dbufs. 858 * We need to guarantee that there is a hold for every dbuf in order to 859 * determine whether the dnode is actively referenced. Falsely matching 860 * a dbuf to an active hold would lead to an unsafe move. It's possible 861 * that a thread already having an active dnode hold is about to add a 862 * dbuf, and we can't compare hold and dbuf counts while the add is in 863 * progress. 864 */ 865 if (!rw_tryenter(&odn->dn_struct_rwlock, RW_WRITER)) { 866 zrl_exit(&odn->dn_handle->dnh_zrlock); 867 mutex_exit(&os->os_lock); 868 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_rwlock); 869 return (KMEM_CBRC_LATER); 870 } 871 872 /* 873 * A dbuf may be removed (evicted) without an active dnode hold. In that 874 * case, the dbuf count is decremented under the handle lock before the 875 * dbuf's hold is released. This order ensures that if we count the hold 876 * after the dbuf is removed but before its hold is released, we will 877 * treat the unmatched hold as active and exit safely. If we count the 878 * hold before the dbuf is removed, the hold is discounted, and the 879 * removal is blocked until the move completes. 880 */ 881 refcount = refcount_count(&odn->dn_holds); 882 ASSERT(refcount >= 0); 883 dbufs = odn->dn_dbufs_count; 884 885 /* We can't have more dbufs than dnode holds. */ 886 ASSERT3U(dbufs, <=, refcount); 887 DTRACE_PROBE3(dnode__move, dnode_t *, odn, int64_t, refcount, 888 uint32_t, dbufs); 889 890 if (refcount > dbufs) { 891 rw_exit(&odn->dn_struct_rwlock); 892 zrl_exit(&odn->dn_handle->dnh_zrlock); 893 mutex_exit(&os->os_lock); 894 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_active); 895 return (KMEM_CBRC_LATER); 896 } 897 898 rw_exit(&odn->dn_struct_rwlock); 899 900 /* 901 * At this point we know that anyone with a hold on the dnode is not 902 * actively referencing it. The dnode is known and in a valid state to 903 * move. We're holding the locks needed to execute the critical section. 904 */ 905 dnode_move_impl(odn, ndn); 906 907 list_link_replace(&odn->dn_link, &ndn->dn_link); 908 /* If the dnode was safe to move, the refcount cannot have changed. */ 909 ASSERT(refcount == refcount_count(&ndn->dn_holds)); 910 ASSERT(dbufs == ndn->dn_dbufs_count); 911 zrl_exit(&ndn->dn_handle->dnh_zrlock); /* handle has moved */ 912 mutex_exit(&os->os_lock); 913 914 return (KMEM_CBRC_YES); 915 } 916 #endif /* _KERNEL */ 917 918 void 919 dnode_special_close(dnode_handle_t *dnh) 920 { 921 dnode_t *dn = dnh->dnh_dnode; 922 923 /* 924 * Wait for final references to the dnode to clear. This can 925 * only happen if the arc is asyncronously evicting state that 926 * has a hold on this dnode while we are trying to evict this 927 * dnode. 928 */ 929 while (refcount_count(&dn->dn_holds) > 0) 930 delay(1); 931 zrl_add(&dnh->dnh_zrlock); 932 dnode_destroy(dn); /* implicit zrl_remove() */ 933 zrl_destroy(&dnh->dnh_zrlock); 934 dnh->dnh_dnode = NULL; 935 } 936 937 dnode_t * 938 dnode_special_open(objset_t *os, dnode_phys_t *dnp, uint64_t object, 939 dnode_handle_t *dnh) 940 { 941 dnode_t *dn = dnode_create(os, dnp, NULL, object, dnh); 942 dnh->dnh_dnode = dn; 943 zrl_init(&dnh->dnh_zrlock); 944 DNODE_VERIFY(dn); 945 return (dn); 946 } 947 948 static void 949 dnode_buf_pageout(dmu_buf_t *db, void *arg) 950 { 951 dnode_children_t *children_dnodes = arg; 952 int i; 953 int epb = db->db_size >> DNODE_SHIFT; 954 955 ASSERT(epb == children_dnodes->dnc_count); 956 957 for (i = 0; i < epb; i++) { 958 dnode_handle_t *dnh = &children_dnodes->dnc_children[i]; 959 dnode_t *dn; 960 961 /* 962 * The dnode handle lock guards against the dnode moving to 963 * another valid address, so there is no need here to guard 964 * against changes to or from NULL. 965 */ 966 if (dnh->dnh_dnode == NULL) { 967 zrl_destroy(&dnh->dnh_zrlock); 968 continue; 969 } 970 971 zrl_add(&dnh->dnh_zrlock); 972 dn = dnh->dnh_dnode; 973 /* 974 * If there are holds on this dnode, then there should 975 * be holds on the dnode's containing dbuf as well; thus 976 * it wouldn't be eligible for eviction and this function 977 * would not have been called. 978 */ 979 ASSERT(refcount_is_zero(&dn->dn_holds)); 980 ASSERT(refcount_is_zero(&dn->dn_tx_holds)); 981 982 dnode_destroy(dn); /* implicit zrl_remove() */ 983 zrl_destroy(&dnh->dnh_zrlock); 984 dnh->dnh_dnode = NULL; 985 } 986 kmem_free(children_dnodes, sizeof (dnode_children_t) + 987 (epb - 1) * sizeof (dnode_handle_t)); 988 } 989 990 /* 991 * errors: 992 * EINVAL - invalid object number. 993 * EIO - i/o error. 994 * succeeds even for free dnodes. 995 */ 996 int 997 dnode_hold_impl(objset_t *os, uint64_t object, int flag, 998 void *tag, dnode_t **dnp) 999 { 1000 int epb, idx, err; 1001 int drop_struct_lock = FALSE; 1002 int type; 1003 uint64_t blk; 1004 dnode_t *mdn, *dn; 1005 dmu_buf_impl_t *db; 1006 dnode_children_t *children_dnodes; 1007 dnode_handle_t *dnh; 1008 1009 /* 1010 * If you are holding the spa config lock as writer, you shouldn't 1011 * be asking the DMU to do *anything* unless it's the root pool 1012 * which may require us to read from the root filesystem while 1013 * holding some (not all) of the locks as writer. 1014 */ 1015 ASSERT(spa_config_held(os->os_spa, SCL_ALL, RW_WRITER) == 0 || 1016 (spa_is_root(os->os_spa) && 1017 spa_config_held(os->os_spa, SCL_STATE, RW_WRITER))); 1018 1019 if (object == DMU_USERUSED_OBJECT || object == DMU_GROUPUSED_OBJECT) { 1020 dn = (object == DMU_USERUSED_OBJECT) ? 1021 DMU_USERUSED_DNODE(os) : DMU_GROUPUSED_DNODE(os); 1022 if (dn == NULL) 1023 return (SET_ERROR(ENOENT)); 1024 type = dn->dn_type; 1025 if ((flag & DNODE_MUST_BE_ALLOCATED) && type == DMU_OT_NONE) 1026 return (SET_ERROR(ENOENT)); 1027 if ((flag & DNODE_MUST_BE_FREE) && type != DMU_OT_NONE) 1028 return (SET_ERROR(EEXIST)); 1029 DNODE_VERIFY(dn); 1030 (void) refcount_add(&dn->dn_holds, tag); 1031 *dnp = dn; 1032 return (0); 1033 } 1034 1035 if (object == 0 || object >= DN_MAX_OBJECT) 1036 return (SET_ERROR(EINVAL)); 1037 1038 mdn = DMU_META_DNODE(os); 1039 ASSERT(mdn->dn_object == DMU_META_DNODE_OBJECT); 1040 1041 DNODE_VERIFY(mdn); 1042 1043 if (!RW_WRITE_HELD(&mdn->dn_struct_rwlock)) { 1044 rw_enter(&mdn->dn_struct_rwlock, RW_READER); 1045 drop_struct_lock = TRUE; 1046 } 1047 1048 blk = dbuf_whichblock(mdn, object * sizeof (dnode_phys_t)); 1049 1050 db = dbuf_hold(mdn, blk, FTAG); 1051 if (drop_struct_lock) 1052 rw_exit(&mdn->dn_struct_rwlock); 1053 if (db == NULL) 1054 return (SET_ERROR(EIO)); 1055 err = dbuf_read(db, NULL, DB_RF_CANFAIL); 1056 if (err) { 1057 dbuf_rele(db, FTAG); 1058 return (err); 1059 } 1060 1061 ASSERT3U(db->db.db_size, >=, 1<<DNODE_SHIFT); 1062 epb = db->db.db_size >> DNODE_SHIFT; 1063 1064 idx = object & (epb-1); 1065 1066 ASSERT(DB_DNODE(db)->dn_type == DMU_OT_DNODE); 1067 children_dnodes = dmu_buf_get_user(&db->db); 1068 if (children_dnodes == NULL) { 1069 int i; 1070 dnode_children_t *winner; 1071 children_dnodes = kmem_alloc(sizeof (dnode_children_t) + 1072 (epb - 1) * sizeof (dnode_handle_t), KM_SLEEP); 1073 children_dnodes->dnc_count = epb; 1074 dnh = &children_dnodes->dnc_children[0]; 1075 for (i = 0; i < epb; i++) { 1076 zrl_init(&dnh[i].dnh_zrlock); 1077 dnh[i].dnh_dnode = NULL; 1078 } 1079 if (winner = dmu_buf_set_user(&db->db, children_dnodes, NULL, 1080 dnode_buf_pageout)) { 1081 kmem_free(children_dnodes, sizeof (dnode_children_t) + 1082 (epb - 1) * sizeof (dnode_handle_t)); 1083 children_dnodes = winner; 1084 } 1085 } 1086 ASSERT(children_dnodes->dnc_count == epb); 1087 1088 dnh = &children_dnodes->dnc_children[idx]; 1089 zrl_add(&dnh->dnh_zrlock); 1090 if ((dn = dnh->dnh_dnode) == NULL) { 1091 dnode_phys_t *phys = (dnode_phys_t *)db->db.db_data+idx; 1092 dnode_t *winner; 1093 1094 dn = dnode_create(os, phys, db, object, dnh); 1095 winner = atomic_cas_ptr(&dnh->dnh_dnode, NULL, dn); 1096 if (winner != NULL) { 1097 zrl_add(&dnh->dnh_zrlock); 1098 dnode_destroy(dn); /* implicit zrl_remove() */ 1099 dn = winner; 1100 } 1101 } 1102 1103 mutex_enter(&dn->dn_mtx); 1104 type = dn->dn_type; 1105 if (dn->dn_free_txg || 1106 ((flag & DNODE_MUST_BE_ALLOCATED) && type == DMU_OT_NONE) || 1107 ((flag & DNODE_MUST_BE_FREE) && 1108 (type != DMU_OT_NONE || !refcount_is_zero(&dn->dn_holds)))) { 1109 mutex_exit(&dn->dn_mtx); 1110 zrl_remove(&dnh->dnh_zrlock); 1111 dbuf_rele(db, FTAG); 1112 return (type == DMU_OT_NONE ? ENOENT : EEXIST); 1113 } 1114 mutex_exit(&dn->dn_mtx); 1115 1116 if (refcount_add(&dn->dn_holds, tag) == 1) 1117 dbuf_add_ref(db, dnh); 1118 /* Now we can rely on the hold to prevent the dnode from moving. */ 1119 zrl_remove(&dnh->dnh_zrlock); 1120 1121 DNODE_VERIFY(dn); 1122 ASSERT3P(dn->dn_dbuf, ==, db); 1123 ASSERT3U(dn->dn_object, ==, object); 1124 dbuf_rele(db, FTAG); 1125 1126 *dnp = dn; 1127 return (0); 1128 } 1129 1130 /* 1131 * Return held dnode if the object is allocated, NULL if not. 1132 */ 1133 int 1134 dnode_hold(objset_t *os, uint64_t object, void *tag, dnode_t **dnp) 1135 { 1136 return (dnode_hold_impl(os, object, DNODE_MUST_BE_ALLOCATED, tag, dnp)); 1137 } 1138 1139 /* 1140 * Can only add a reference if there is already at least one 1141 * reference on the dnode. Returns FALSE if unable to add a 1142 * new reference. 1143 */ 1144 boolean_t 1145 dnode_add_ref(dnode_t *dn, void *tag) 1146 { 1147 mutex_enter(&dn->dn_mtx); 1148 if (refcount_is_zero(&dn->dn_holds)) { 1149 mutex_exit(&dn->dn_mtx); 1150 return (FALSE); 1151 } 1152 VERIFY(1 < refcount_add(&dn->dn_holds, tag)); 1153 mutex_exit(&dn->dn_mtx); 1154 return (TRUE); 1155 } 1156 1157 void 1158 dnode_rele(dnode_t *dn, void *tag) 1159 { 1160 uint64_t refs; 1161 /* Get while the hold prevents the dnode from moving. */ 1162 dmu_buf_impl_t *db = dn->dn_dbuf; 1163 dnode_handle_t *dnh = dn->dn_handle; 1164 1165 mutex_enter(&dn->dn_mtx); 1166 refs = refcount_remove(&dn->dn_holds, tag); 1167 mutex_exit(&dn->dn_mtx); 1168 1169 /* 1170 * It's unsafe to release the last hold on a dnode by dnode_rele() or 1171 * indirectly by dbuf_rele() while relying on the dnode handle to 1172 * prevent the dnode from moving, since releasing the last hold could 1173 * result in the dnode's parent dbuf evicting its dnode handles. For 1174 * that reason anyone calling dnode_rele() or dbuf_rele() without some 1175 * other direct or indirect hold on the dnode must first drop the dnode 1176 * handle. 1177 */ 1178 ASSERT(refs > 0 || dnh->dnh_zrlock.zr_owner != curthread); 1179 1180 /* NOTE: the DNODE_DNODE does not have a dn_dbuf */ 1181 if (refs == 0 && db != NULL) { 1182 /* 1183 * Another thread could add a hold to the dnode handle in 1184 * dnode_hold_impl() while holding the parent dbuf. Since the 1185 * hold on the parent dbuf prevents the handle from being 1186 * destroyed, the hold on the handle is OK. We can't yet assert 1187 * that the handle has zero references, but that will be 1188 * asserted anyway when the handle gets destroyed. 1189 */ 1190 dbuf_rele(db, dnh); 1191 } 1192 } 1193 1194 void 1195 dnode_setdirty(dnode_t *dn, dmu_tx_t *tx) 1196 { 1197 objset_t *os = dn->dn_objset; 1198 uint64_t txg = tx->tx_txg; 1199 1200 if (DMU_OBJECT_IS_SPECIAL(dn->dn_object)) { 1201 dsl_dataset_dirty(os->os_dsl_dataset, tx); 1202 return; 1203 } 1204 1205 DNODE_VERIFY(dn); 1206 1207 #ifdef ZFS_DEBUG 1208 mutex_enter(&dn->dn_mtx); 1209 ASSERT(dn->dn_phys->dn_type || dn->dn_allocated_txg); 1210 ASSERT(dn->dn_free_txg == 0 || dn->dn_free_txg >= txg); 1211 mutex_exit(&dn->dn_mtx); 1212 #endif 1213 1214 /* 1215 * Determine old uid/gid when necessary 1216 */ 1217 dmu_objset_userquota_get_ids(dn, B_TRUE, tx); 1218 1219 mutex_enter(&os->os_lock); 1220 1221 /* 1222 * If we are already marked dirty, we're done. 1223 */ 1224 if (list_link_active(&dn->dn_dirty_link[txg & TXG_MASK])) { 1225 mutex_exit(&os->os_lock); 1226 return; 1227 } 1228 1229 ASSERT(!refcount_is_zero(&dn->dn_holds) || list_head(&dn->dn_dbufs)); 1230 ASSERT(dn->dn_datablksz != 0); 1231 ASSERT0(dn->dn_next_bonuslen[txg&TXG_MASK]); 1232 ASSERT0(dn->dn_next_blksz[txg&TXG_MASK]); 1233 ASSERT0(dn->dn_next_bonustype[txg&TXG_MASK]); 1234 1235 dprintf_ds(os->os_dsl_dataset, "obj=%llu txg=%llu\n", 1236 dn->dn_object, txg); 1237 1238 if (dn->dn_free_txg > 0 && dn->dn_free_txg <= txg) { 1239 list_insert_tail(&os->os_free_dnodes[txg&TXG_MASK], dn); 1240 } else { 1241 list_insert_tail(&os->os_dirty_dnodes[txg&TXG_MASK], dn); 1242 } 1243 1244 mutex_exit(&os->os_lock); 1245 1246 /* 1247 * The dnode maintains a hold on its containing dbuf as 1248 * long as there are holds on it. Each instantiated child 1249 * dbuf maintains a hold on the dnode. When the last child 1250 * drops its hold, the dnode will drop its hold on the 1251 * containing dbuf. We add a "dirty hold" here so that the 1252 * dnode will hang around after we finish processing its 1253 * children. 1254 */ 1255 VERIFY(dnode_add_ref(dn, (void *)(uintptr_t)tx->tx_txg)); 1256 1257 (void) dbuf_dirty(dn->dn_dbuf, tx); 1258 1259 dsl_dataset_dirty(os->os_dsl_dataset, tx); 1260 } 1261 1262 void 1263 dnode_free(dnode_t *dn, dmu_tx_t *tx) 1264 { 1265 int txgoff = tx->tx_txg & TXG_MASK; 1266 1267 dprintf("dn=%p txg=%llu\n", dn, tx->tx_txg); 1268 1269 /* we should be the only holder... hopefully */ 1270 /* ASSERT3U(refcount_count(&dn->dn_holds), ==, 1); */ 1271 1272 mutex_enter(&dn->dn_mtx); 1273 if (dn->dn_type == DMU_OT_NONE || dn->dn_free_txg) { 1274 mutex_exit(&dn->dn_mtx); 1275 return; 1276 } 1277 dn->dn_free_txg = tx->tx_txg; 1278 mutex_exit(&dn->dn_mtx); 1279 1280 /* 1281 * If the dnode is already dirty, it needs to be moved from 1282 * the dirty list to the free list. 1283 */ 1284 mutex_enter(&dn->dn_objset->os_lock); 1285 if (list_link_active(&dn->dn_dirty_link[txgoff])) { 1286 list_remove(&dn->dn_objset->os_dirty_dnodes[txgoff], dn); 1287 list_insert_tail(&dn->dn_objset->os_free_dnodes[txgoff], dn); 1288 mutex_exit(&dn->dn_objset->os_lock); 1289 } else { 1290 mutex_exit(&dn->dn_objset->os_lock); 1291 dnode_setdirty(dn, tx); 1292 } 1293 } 1294 1295 /* 1296 * Try to change the block size for the indicated dnode. This can only 1297 * succeed if there are no blocks allocated or dirty beyond first block 1298 */ 1299 int 1300 dnode_set_blksz(dnode_t *dn, uint64_t size, int ibs, dmu_tx_t *tx) 1301 { 1302 dmu_buf_impl_t *db, *db_next; 1303 int err; 1304 1305 if (size == 0) 1306 size = SPA_MINBLOCKSIZE; 1307 if (size > SPA_MAXBLOCKSIZE) 1308 size = SPA_MAXBLOCKSIZE; 1309 else 1310 size = P2ROUNDUP(size, SPA_MINBLOCKSIZE); 1311 1312 if (ibs == dn->dn_indblkshift) 1313 ibs = 0; 1314 1315 if (size >> SPA_MINBLOCKSHIFT == dn->dn_datablkszsec && ibs == 0) 1316 return (0); 1317 1318 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 1319 1320 /* Check for any allocated blocks beyond the first */ 1321 if (dn->dn_maxblkid != 0) 1322 goto fail; 1323 1324 mutex_enter(&dn->dn_dbufs_mtx); 1325 for (db = list_head(&dn->dn_dbufs); db; db = db_next) { 1326 db_next = list_next(&dn->dn_dbufs, db); 1327 1328 if (db->db_blkid != 0 && db->db_blkid != DMU_BONUS_BLKID && 1329 db->db_blkid != DMU_SPILL_BLKID) { 1330 mutex_exit(&dn->dn_dbufs_mtx); 1331 goto fail; 1332 } 1333 } 1334 mutex_exit(&dn->dn_dbufs_mtx); 1335 1336 if (ibs && dn->dn_nlevels != 1) 1337 goto fail; 1338 1339 /* resize the old block */ 1340 err = dbuf_hold_impl(dn, 0, 0, TRUE, FTAG, &db); 1341 if (err == 0) 1342 dbuf_new_size(db, size, tx); 1343 else if (err != ENOENT) 1344 goto fail; 1345 1346 dnode_setdblksz(dn, size); 1347 dnode_setdirty(dn, tx); 1348 dn->dn_next_blksz[tx->tx_txg&TXG_MASK] = size; 1349 if (ibs) { 1350 dn->dn_indblkshift = ibs; 1351 dn->dn_next_indblkshift[tx->tx_txg&TXG_MASK] = ibs; 1352 } 1353 /* rele after we have fixed the blocksize in the dnode */ 1354 if (db) 1355 dbuf_rele(db, FTAG); 1356 1357 rw_exit(&dn->dn_struct_rwlock); 1358 return (0); 1359 1360 fail: 1361 rw_exit(&dn->dn_struct_rwlock); 1362 return (SET_ERROR(ENOTSUP)); 1363 } 1364 1365 /* read-holding callers must not rely on the lock being continuously held */ 1366 void 1367 dnode_new_blkid(dnode_t *dn, uint64_t blkid, dmu_tx_t *tx, boolean_t have_read) 1368 { 1369 uint64_t txgoff = tx->tx_txg & TXG_MASK; 1370 int epbs, new_nlevels; 1371 uint64_t sz; 1372 1373 ASSERT(blkid != DMU_BONUS_BLKID); 1374 1375 ASSERT(have_read ? 1376 RW_READ_HELD(&dn->dn_struct_rwlock) : 1377 RW_WRITE_HELD(&dn->dn_struct_rwlock)); 1378 1379 /* 1380 * if we have a read-lock, check to see if we need to do any work 1381 * before upgrading to a write-lock. 1382 */ 1383 if (have_read) { 1384 if (blkid <= dn->dn_maxblkid) 1385 return; 1386 1387 if (!rw_tryupgrade(&dn->dn_struct_rwlock)) { 1388 rw_exit(&dn->dn_struct_rwlock); 1389 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 1390 } 1391 } 1392 1393 if (blkid <= dn->dn_maxblkid) 1394 goto out; 1395 1396 dn->dn_maxblkid = blkid; 1397 1398 /* 1399 * Compute the number of levels necessary to support the new maxblkid. 1400 */ 1401 new_nlevels = 1; 1402 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT; 1403 for (sz = dn->dn_nblkptr; 1404 sz <= blkid && sz >= dn->dn_nblkptr; sz <<= epbs) 1405 new_nlevels++; 1406 1407 if (new_nlevels > dn->dn_nlevels) { 1408 int old_nlevels = dn->dn_nlevels; 1409 dmu_buf_impl_t *db; 1410 list_t *list; 1411 dbuf_dirty_record_t *new, *dr, *dr_next; 1412 1413 dn->dn_nlevels = new_nlevels; 1414 1415 ASSERT3U(new_nlevels, >, dn->dn_next_nlevels[txgoff]); 1416 dn->dn_next_nlevels[txgoff] = new_nlevels; 1417 1418 /* dirty the left indirects */ 1419 db = dbuf_hold_level(dn, old_nlevels, 0, FTAG); 1420 ASSERT(db != NULL); 1421 new = dbuf_dirty(db, tx); 1422 dbuf_rele(db, FTAG); 1423 1424 /* transfer the dirty records to the new indirect */ 1425 mutex_enter(&dn->dn_mtx); 1426 mutex_enter(&new->dt.di.dr_mtx); 1427 list = &dn->dn_dirty_records[txgoff]; 1428 for (dr = list_head(list); dr; dr = dr_next) { 1429 dr_next = list_next(&dn->dn_dirty_records[txgoff], dr); 1430 if (dr->dr_dbuf->db_level != new_nlevels-1 && 1431 dr->dr_dbuf->db_blkid != DMU_BONUS_BLKID && 1432 dr->dr_dbuf->db_blkid != DMU_SPILL_BLKID) { 1433 ASSERT(dr->dr_dbuf->db_level == old_nlevels-1); 1434 list_remove(&dn->dn_dirty_records[txgoff], dr); 1435 list_insert_tail(&new->dt.di.dr_children, dr); 1436 dr->dr_parent = new; 1437 } 1438 } 1439 mutex_exit(&new->dt.di.dr_mtx); 1440 mutex_exit(&dn->dn_mtx); 1441 } 1442 1443 out: 1444 if (have_read) 1445 rw_downgrade(&dn->dn_struct_rwlock); 1446 } 1447 1448 void 1449 dnode_free_range(dnode_t *dn, uint64_t off, uint64_t len, dmu_tx_t *tx) 1450 { 1451 dmu_buf_impl_t *db; 1452 uint64_t blkoff, blkid, nblks; 1453 int blksz, blkshift, head, tail; 1454 int trunc = FALSE; 1455 int epbs; 1456 1457 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 1458 blksz = dn->dn_datablksz; 1459 blkshift = dn->dn_datablkshift; 1460 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT; 1461 1462 if (len == DMU_OBJECT_END) { 1463 len = UINT64_MAX - off; 1464 trunc = TRUE; 1465 } 1466 1467 /* 1468 * First, block align the region to free: 1469 */ 1470 if (ISP2(blksz)) { 1471 head = P2NPHASE(off, blksz); 1472 blkoff = P2PHASE(off, blksz); 1473 if ((off >> blkshift) > dn->dn_maxblkid) 1474 goto out; 1475 } else { 1476 ASSERT(dn->dn_maxblkid == 0); 1477 if (off == 0 && len >= blksz) { 1478 /* 1479 * Freeing the whole block; fast-track this request. 1480 * Note that we won't dirty any indirect blocks, 1481 * which is fine because we will be freeing the entire 1482 * file and thus all indirect blocks will be freed 1483 * by free_children(). 1484 */ 1485 blkid = 0; 1486 nblks = 1; 1487 goto done; 1488 } else if (off >= blksz) { 1489 /* Freeing past end-of-data */ 1490 goto out; 1491 } else { 1492 /* Freeing part of the block. */ 1493 head = blksz - off; 1494 ASSERT3U(head, >, 0); 1495 } 1496 blkoff = off; 1497 } 1498 /* zero out any partial block data at the start of the range */ 1499 if (head) { 1500 ASSERT3U(blkoff + head, ==, blksz); 1501 if (len < head) 1502 head = len; 1503 if (dbuf_hold_impl(dn, 0, dbuf_whichblock(dn, off), TRUE, 1504 FTAG, &db) == 0) { 1505 caddr_t data; 1506 1507 /* don't dirty if it isn't on disk and isn't dirty */ 1508 if (db->db_last_dirty || 1509 (db->db_blkptr && !BP_IS_HOLE(db->db_blkptr))) { 1510 rw_exit(&dn->dn_struct_rwlock); 1511 dmu_buf_will_dirty(&db->db, tx); 1512 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 1513 data = db->db.db_data; 1514 bzero(data + blkoff, head); 1515 } 1516 dbuf_rele(db, FTAG); 1517 } 1518 off += head; 1519 len -= head; 1520 } 1521 1522 /* If the range was less than one block, we're done */ 1523 if (len == 0) 1524 goto out; 1525 1526 /* If the remaining range is past end of file, we're done */ 1527 if ((off >> blkshift) > dn->dn_maxblkid) 1528 goto out; 1529 1530 ASSERT(ISP2(blksz)); 1531 if (trunc) 1532 tail = 0; 1533 else 1534 tail = P2PHASE(len, blksz); 1535 1536 ASSERT0(P2PHASE(off, blksz)); 1537 /* zero out any partial block data at the end of the range */ 1538 if (tail) { 1539 if (len < tail) 1540 tail = len; 1541 if (dbuf_hold_impl(dn, 0, dbuf_whichblock(dn, off+len), 1542 TRUE, FTAG, &db) == 0) { 1543 /* don't dirty if not on disk and not dirty */ 1544 if (db->db_last_dirty || 1545 (db->db_blkptr && !BP_IS_HOLE(db->db_blkptr))) { 1546 rw_exit(&dn->dn_struct_rwlock); 1547 dmu_buf_will_dirty(&db->db, tx); 1548 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 1549 bzero(db->db.db_data, tail); 1550 } 1551 dbuf_rele(db, FTAG); 1552 } 1553 len -= tail; 1554 } 1555 1556 /* If the range did not include a full block, we are done */ 1557 if (len == 0) 1558 goto out; 1559 1560 ASSERT(IS_P2ALIGNED(off, blksz)); 1561 ASSERT(trunc || IS_P2ALIGNED(len, blksz)); 1562 blkid = off >> blkshift; 1563 nblks = len >> blkshift; 1564 if (trunc) 1565 nblks += 1; 1566 1567 /* 1568 * Dirty the first and last indirect blocks, as they (and/or their 1569 * parents) will need to be written out if they were only 1570 * partially freed. Interior indirect blocks will be themselves freed, 1571 * by free_children(), so they need not be dirtied. Note that these 1572 * interior blocks have already been prefetched by dmu_tx_hold_free(). 1573 */ 1574 if (dn->dn_nlevels > 1) { 1575 uint64_t first, last; 1576 1577 first = blkid >> epbs; 1578 if (db = dbuf_hold_level(dn, 1, first, FTAG)) { 1579 dmu_buf_will_dirty(&db->db, tx); 1580 dbuf_rele(db, FTAG); 1581 } 1582 if (trunc) 1583 last = dn->dn_maxblkid >> epbs; 1584 else 1585 last = (blkid + nblks - 1) >> epbs; 1586 if (last > first && (db = dbuf_hold_level(dn, 1, last, FTAG))) { 1587 dmu_buf_will_dirty(&db->db, tx); 1588 dbuf_rele(db, FTAG); 1589 } 1590 } 1591 1592 done: 1593 /* 1594 * Add this range to the dnode range list. 1595 * We will finish up this free operation in the syncing phase. 1596 */ 1597 mutex_enter(&dn->dn_mtx); 1598 int txgoff = tx->tx_txg & TXG_MASK; 1599 if (dn->dn_free_ranges[txgoff] == NULL) { 1600 dn->dn_free_ranges[txgoff] = 1601 range_tree_create(NULL, NULL, &dn->dn_mtx); 1602 } 1603 range_tree_clear(dn->dn_free_ranges[txgoff], blkid, nblks); 1604 range_tree_add(dn->dn_free_ranges[txgoff], blkid, nblks); 1605 dprintf_dnode(dn, "blkid=%llu nblks=%llu txg=%llu\n", 1606 blkid, nblks, tx->tx_txg); 1607 mutex_exit(&dn->dn_mtx); 1608 1609 dbuf_free_range(dn, blkid, blkid + nblks - 1, tx); 1610 dnode_setdirty(dn, tx); 1611 out: 1612 1613 rw_exit(&dn->dn_struct_rwlock); 1614 } 1615 1616 static boolean_t 1617 dnode_spill_freed(dnode_t *dn) 1618 { 1619 int i; 1620 1621 mutex_enter(&dn->dn_mtx); 1622 for (i = 0; i < TXG_SIZE; i++) { 1623 if (dn->dn_rm_spillblk[i] == DN_KILL_SPILLBLK) 1624 break; 1625 } 1626 mutex_exit(&dn->dn_mtx); 1627 return (i < TXG_SIZE); 1628 } 1629 1630 /* return TRUE if this blkid was freed in a recent txg, or FALSE if it wasn't */ 1631 uint64_t 1632 dnode_block_freed(dnode_t *dn, uint64_t blkid) 1633 { 1634 void *dp = spa_get_dsl(dn->dn_objset->os_spa); 1635 int i; 1636 1637 if (blkid == DMU_BONUS_BLKID) 1638 return (FALSE); 1639 1640 /* 1641 * If we're in the process of opening the pool, dp will not be 1642 * set yet, but there shouldn't be anything dirty. 1643 */ 1644 if (dp == NULL) 1645 return (FALSE); 1646 1647 if (dn->dn_free_txg) 1648 return (TRUE); 1649 1650 if (blkid == DMU_SPILL_BLKID) 1651 return (dnode_spill_freed(dn)); 1652 1653 mutex_enter(&dn->dn_mtx); 1654 for (i = 0; i < TXG_SIZE; i++) { 1655 if (dn->dn_free_ranges[i] != NULL && 1656 range_tree_contains(dn->dn_free_ranges[i], blkid, 1)) 1657 break; 1658 } 1659 mutex_exit(&dn->dn_mtx); 1660 return (i < TXG_SIZE); 1661 } 1662 1663 /* call from syncing context when we actually write/free space for this dnode */ 1664 void 1665 dnode_diduse_space(dnode_t *dn, int64_t delta) 1666 { 1667 uint64_t space; 1668 dprintf_dnode(dn, "dn=%p dnp=%p used=%llu delta=%lld\n", 1669 dn, dn->dn_phys, 1670 (u_longlong_t)dn->dn_phys->dn_used, 1671 (longlong_t)delta); 1672 1673 mutex_enter(&dn->dn_mtx); 1674 space = DN_USED_BYTES(dn->dn_phys); 1675 if (delta > 0) { 1676 ASSERT3U(space + delta, >=, space); /* no overflow */ 1677 } else { 1678 ASSERT3U(space, >=, -delta); /* no underflow */ 1679 } 1680 space += delta; 1681 if (spa_version(dn->dn_objset->os_spa) < SPA_VERSION_DNODE_BYTES) { 1682 ASSERT((dn->dn_phys->dn_flags & DNODE_FLAG_USED_BYTES) == 0); 1683 ASSERT0(P2PHASE(space, 1<<DEV_BSHIFT)); 1684 dn->dn_phys->dn_used = space >> DEV_BSHIFT; 1685 } else { 1686 dn->dn_phys->dn_used = space; 1687 dn->dn_phys->dn_flags |= DNODE_FLAG_USED_BYTES; 1688 } 1689 mutex_exit(&dn->dn_mtx); 1690 } 1691 1692 /* 1693 * Call when we think we're going to write/free space in open context to track 1694 * the amount of memory in use by the currently open txg. 1695 */ 1696 void 1697 dnode_willuse_space(dnode_t *dn, int64_t space, dmu_tx_t *tx) 1698 { 1699 objset_t *os = dn->dn_objset; 1700 dsl_dataset_t *ds = os->os_dsl_dataset; 1701 int64_t aspace = spa_get_asize(os->os_spa, space); 1702 1703 if (ds != NULL) { 1704 dsl_dir_willuse_space(ds->ds_dir, aspace, tx); 1705 dsl_pool_dirty_space(dmu_tx_pool(tx), space, tx); 1706 } 1707 1708 dmu_tx_willuse_space(tx, aspace); 1709 } 1710 1711 /* 1712 * Scans a block at the indicated "level" looking for a hole or data, 1713 * depending on 'flags'. 1714 * 1715 * If level > 0, then we are scanning an indirect block looking at its 1716 * pointers. If level == 0, then we are looking at a block of dnodes. 1717 * 1718 * If we don't find what we are looking for in the block, we return ESRCH. 1719 * Otherwise, return with *offset pointing to the beginning (if searching 1720 * forwards) or end (if searching backwards) of the range covered by the 1721 * block pointer we matched on (or dnode). 1722 * 1723 * The basic search algorithm used below by dnode_next_offset() is to 1724 * use this function to search up the block tree (widen the search) until 1725 * we find something (i.e., we don't return ESRCH) and then search back 1726 * down the tree (narrow the search) until we reach our original search 1727 * level. 1728 */ 1729 static int 1730 dnode_next_offset_level(dnode_t *dn, int flags, uint64_t *offset, 1731 int lvl, uint64_t blkfill, uint64_t txg) 1732 { 1733 dmu_buf_impl_t *db = NULL; 1734 void *data = NULL; 1735 uint64_t epbs = dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT; 1736 uint64_t epb = 1ULL << epbs; 1737 uint64_t minfill, maxfill; 1738 boolean_t hole; 1739 int i, inc, error, span; 1740 1741 dprintf("probing object %llu offset %llx level %d of %u\n", 1742 dn->dn_object, *offset, lvl, dn->dn_phys->dn_nlevels); 1743 1744 hole = ((flags & DNODE_FIND_HOLE) != 0); 1745 inc = (flags & DNODE_FIND_BACKWARDS) ? -1 : 1; 1746 ASSERT(txg == 0 || !hole); 1747 1748 if (lvl == dn->dn_phys->dn_nlevels) { 1749 error = 0; 1750 epb = dn->dn_phys->dn_nblkptr; 1751 data = dn->dn_phys->dn_blkptr; 1752 } else { 1753 uint64_t blkid = dbuf_whichblock(dn, *offset) >> (epbs * lvl); 1754 error = dbuf_hold_impl(dn, lvl, blkid, TRUE, FTAG, &db); 1755 if (error) { 1756 if (error != ENOENT) 1757 return (error); 1758 if (hole) 1759 return (0); 1760 /* 1761 * This can only happen when we are searching up 1762 * the block tree for data. We don't really need to 1763 * adjust the offset, as we will just end up looking 1764 * at the pointer to this block in its parent, and its 1765 * going to be unallocated, so we will skip over it. 1766 */ 1767 return (SET_ERROR(ESRCH)); 1768 } 1769 error = dbuf_read(db, NULL, DB_RF_CANFAIL | DB_RF_HAVESTRUCT); 1770 if (error) { 1771 dbuf_rele(db, FTAG); 1772 return (error); 1773 } 1774 data = db->db.db_data; 1775 } 1776 1777 1778 if (db != NULL && txg != 0 && (db->db_blkptr == NULL || 1779 db->db_blkptr->blk_birth <= txg || 1780 BP_IS_HOLE(db->db_blkptr))) { 1781 /* 1782 * This can only happen when we are searching up the tree 1783 * and these conditions mean that we need to keep climbing. 1784 */ 1785 error = SET_ERROR(ESRCH); 1786 } else if (lvl == 0) { 1787 dnode_phys_t *dnp = data; 1788 span = DNODE_SHIFT; 1789 ASSERT(dn->dn_type == DMU_OT_DNODE); 1790 1791 for (i = (*offset >> span) & (blkfill - 1); 1792 i >= 0 && i < blkfill; i += inc) { 1793 if ((dnp[i].dn_type == DMU_OT_NONE) == hole) 1794 break; 1795 *offset += (1ULL << span) * inc; 1796 } 1797 if (i < 0 || i == blkfill) 1798 error = SET_ERROR(ESRCH); 1799 } else { 1800 blkptr_t *bp = data; 1801 uint64_t start = *offset; 1802 span = (lvl - 1) * epbs + dn->dn_datablkshift; 1803 minfill = 0; 1804 maxfill = blkfill << ((lvl - 1) * epbs); 1805 1806 if (hole) 1807 maxfill--; 1808 else 1809 minfill++; 1810 1811 *offset = *offset >> span; 1812 for (i = BF64_GET(*offset, 0, epbs); 1813 i >= 0 && i < epb; i += inc) { 1814 if (bp[i].blk_fill >= minfill && 1815 bp[i].blk_fill <= maxfill && 1816 (hole || bp[i].blk_birth > txg)) 1817 break; 1818 if (inc > 0 || *offset > 0) 1819 *offset += inc; 1820 } 1821 *offset = *offset << span; 1822 if (inc < 0) { 1823 /* traversing backwards; position offset at the end */ 1824 ASSERT3U(*offset, <=, start); 1825 *offset = MIN(*offset + (1ULL << span) - 1, start); 1826 } else if (*offset < start) { 1827 *offset = start; 1828 } 1829 if (i < 0 || i >= epb) 1830 error = SET_ERROR(ESRCH); 1831 } 1832 1833 if (db) 1834 dbuf_rele(db, FTAG); 1835 1836 return (error); 1837 } 1838 1839 /* 1840 * Find the next hole, data, or sparse region at or after *offset. 1841 * The value 'blkfill' tells us how many items we expect to find 1842 * in an L0 data block; this value is 1 for normal objects, 1843 * DNODES_PER_BLOCK for the meta dnode, and some fraction of 1844 * DNODES_PER_BLOCK when searching for sparse regions thereof. 1845 * 1846 * Examples: 1847 * 1848 * dnode_next_offset(dn, flags, offset, 1, 1, 0); 1849 * Finds the next/previous hole/data in a file. 1850 * Used in dmu_offset_next(). 1851 * 1852 * dnode_next_offset(mdn, flags, offset, 0, DNODES_PER_BLOCK, txg); 1853 * Finds the next free/allocated dnode an objset's meta-dnode. 1854 * Only finds objects that have new contents since txg (ie. 1855 * bonus buffer changes and content removal are ignored). 1856 * Used in dmu_object_next(). 1857 * 1858 * dnode_next_offset(mdn, DNODE_FIND_HOLE, offset, 2, DNODES_PER_BLOCK >> 2, 0); 1859 * Finds the next L2 meta-dnode bp that's at most 1/4 full. 1860 * Used in dmu_object_alloc(). 1861 */ 1862 int 1863 dnode_next_offset(dnode_t *dn, int flags, uint64_t *offset, 1864 int minlvl, uint64_t blkfill, uint64_t txg) 1865 { 1866 uint64_t initial_offset = *offset; 1867 int lvl, maxlvl; 1868 int error = 0; 1869 1870 if (!(flags & DNODE_FIND_HAVELOCK)) 1871 rw_enter(&dn->dn_struct_rwlock, RW_READER); 1872 1873 if (dn->dn_phys->dn_nlevels == 0) { 1874 error = SET_ERROR(ESRCH); 1875 goto out; 1876 } 1877 1878 if (dn->dn_datablkshift == 0) { 1879 if (*offset < dn->dn_datablksz) { 1880 if (flags & DNODE_FIND_HOLE) 1881 *offset = dn->dn_datablksz; 1882 } else { 1883 error = SET_ERROR(ESRCH); 1884 } 1885 goto out; 1886 } 1887 1888 maxlvl = dn->dn_phys->dn_nlevels; 1889 1890 for (lvl = minlvl; lvl <= maxlvl; lvl++) { 1891 error = dnode_next_offset_level(dn, 1892 flags, offset, lvl, blkfill, txg); 1893 if (error != ESRCH) 1894 break; 1895 } 1896 1897 while (error == 0 && --lvl >= minlvl) { 1898 error = dnode_next_offset_level(dn, 1899 flags, offset, lvl, blkfill, txg); 1900 } 1901 1902 if (error == 0 && (flags & DNODE_FIND_BACKWARDS ? 1903 initial_offset < *offset : initial_offset > *offset)) 1904 error = SET_ERROR(ESRCH); 1905 out: 1906 if (!(flags & DNODE_FIND_HAVELOCK)) 1907 rw_exit(&dn->dn_struct_rwlock); 1908 1909 return (error); 1910 } 1911