1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 /* 22 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. 23 * Copyright (c) 2013 by Delphix. All rights reserved. 24 */ 25 26 #include <sys/zfs_context.h> 27 #include <sys/dbuf.h> 28 #include <sys/dnode.h> 29 #include <sys/dmu.h> 30 #include <sys/dmu_impl.h> 31 #include <sys/dmu_tx.h> 32 #include <sys/dmu_objset.h> 33 #include <sys/dsl_dir.h> 34 #include <sys/dsl_dataset.h> 35 #include <sys/spa.h> 36 #include <sys/zio.h> 37 #include <sys/dmu_zfetch.h> 38 39 static int free_range_compar(const void *node1, const void *node2); 40 41 static kmem_cache_t *dnode_cache; 42 /* 43 * Define DNODE_STATS to turn on statistic gathering. By default, it is only 44 * turned on when DEBUG is also defined. 45 */ 46 #ifdef DEBUG 47 #define DNODE_STATS 48 #endif /* DEBUG */ 49 50 #ifdef DNODE_STATS 51 #define DNODE_STAT_ADD(stat) ((stat)++) 52 #else 53 #define DNODE_STAT_ADD(stat) /* nothing */ 54 #endif /* DNODE_STATS */ 55 56 static dnode_phys_t dnode_phys_zero; 57 58 int zfs_default_bs = SPA_MINBLOCKSHIFT; 59 int zfs_default_ibs = DN_MAX_INDBLKSHIFT; 60 61 static kmem_cbrc_t dnode_move(void *, void *, size_t, void *); 62 63 /* ARGSUSED */ 64 static int 65 dnode_cons(void *arg, void *unused, int kmflag) 66 { 67 dnode_t *dn = arg; 68 int i; 69 70 rw_init(&dn->dn_struct_rwlock, NULL, RW_DEFAULT, NULL); 71 mutex_init(&dn->dn_mtx, NULL, MUTEX_DEFAULT, NULL); 72 mutex_init(&dn->dn_dbufs_mtx, NULL, MUTEX_DEFAULT, NULL); 73 cv_init(&dn->dn_notxholds, NULL, CV_DEFAULT, NULL); 74 75 /* 76 * Every dbuf has a reference, and dropping a tracked reference is 77 * O(number of references), so don't track dn_holds. 78 */ 79 refcount_create_untracked(&dn->dn_holds); 80 refcount_create(&dn->dn_tx_holds); 81 list_link_init(&dn->dn_link); 82 83 bzero(&dn->dn_next_nblkptr[0], sizeof (dn->dn_next_nblkptr)); 84 bzero(&dn->dn_next_nlevels[0], sizeof (dn->dn_next_nlevels)); 85 bzero(&dn->dn_next_indblkshift[0], sizeof (dn->dn_next_indblkshift)); 86 bzero(&dn->dn_next_bonustype[0], sizeof (dn->dn_next_bonustype)); 87 bzero(&dn->dn_rm_spillblk[0], sizeof (dn->dn_rm_spillblk)); 88 bzero(&dn->dn_next_bonuslen[0], sizeof (dn->dn_next_bonuslen)); 89 bzero(&dn->dn_next_blksz[0], sizeof (dn->dn_next_blksz)); 90 91 for (i = 0; i < TXG_SIZE; i++) { 92 list_link_init(&dn->dn_dirty_link[i]); 93 avl_create(&dn->dn_ranges[i], free_range_compar, 94 sizeof (free_range_t), 95 offsetof(struct free_range, fr_node)); 96 list_create(&dn->dn_dirty_records[i], 97 sizeof (dbuf_dirty_record_t), 98 offsetof(dbuf_dirty_record_t, dr_dirty_node)); 99 } 100 101 dn->dn_allocated_txg = 0; 102 dn->dn_free_txg = 0; 103 dn->dn_assigned_txg = 0; 104 dn->dn_dirtyctx = 0; 105 dn->dn_dirtyctx_firstset = NULL; 106 dn->dn_bonus = NULL; 107 dn->dn_have_spill = B_FALSE; 108 dn->dn_zio = NULL; 109 dn->dn_oldused = 0; 110 dn->dn_oldflags = 0; 111 dn->dn_olduid = 0; 112 dn->dn_oldgid = 0; 113 dn->dn_newuid = 0; 114 dn->dn_newgid = 0; 115 dn->dn_id_flags = 0; 116 117 dn->dn_dbufs_count = 0; 118 list_create(&dn->dn_dbufs, sizeof (dmu_buf_impl_t), 119 offsetof(dmu_buf_impl_t, db_link)); 120 121 dn->dn_moved = 0; 122 return (0); 123 } 124 125 /* ARGSUSED */ 126 static void 127 dnode_dest(void *arg, void *unused) 128 { 129 int i; 130 dnode_t *dn = arg; 131 132 rw_destroy(&dn->dn_struct_rwlock); 133 mutex_destroy(&dn->dn_mtx); 134 mutex_destroy(&dn->dn_dbufs_mtx); 135 cv_destroy(&dn->dn_notxholds); 136 refcount_destroy(&dn->dn_holds); 137 refcount_destroy(&dn->dn_tx_holds); 138 ASSERT(!list_link_active(&dn->dn_link)); 139 140 for (i = 0; i < TXG_SIZE; i++) { 141 ASSERT(!list_link_active(&dn->dn_dirty_link[i])); 142 avl_destroy(&dn->dn_ranges[i]); 143 list_destroy(&dn->dn_dirty_records[i]); 144 ASSERT0(dn->dn_next_nblkptr[i]); 145 ASSERT0(dn->dn_next_nlevels[i]); 146 ASSERT0(dn->dn_next_indblkshift[i]); 147 ASSERT0(dn->dn_next_bonustype[i]); 148 ASSERT0(dn->dn_rm_spillblk[i]); 149 ASSERT0(dn->dn_next_bonuslen[i]); 150 ASSERT0(dn->dn_next_blksz[i]); 151 } 152 153 ASSERT0(dn->dn_allocated_txg); 154 ASSERT0(dn->dn_free_txg); 155 ASSERT0(dn->dn_assigned_txg); 156 ASSERT0(dn->dn_dirtyctx); 157 ASSERT3P(dn->dn_dirtyctx_firstset, ==, NULL); 158 ASSERT3P(dn->dn_bonus, ==, NULL); 159 ASSERT(!dn->dn_have_spill); 160 ASSERT3P(dn->dn_zio, ==, NULL); 161 ASSERT0(dn->dn_oldused); 162 ASSERT0(dn->dn_oldflags); 163 ASSERT0(dn->dn_olduid); 164 ASSERT0(dn->dn_oldgid); 165 ASSERT0(dn->dn_newuid); 166 ASSERT0(dn->dn_newgid); 167 ASSERT0(dn->dn_id_flags); 168 169 ASSERT0(dn->dn_dbufs_count); 170 list_destroy(&dn->dn_dbufs); 171 } 172 173 void 174 dnode_init(void) 175 { 176 ASSERT(dnode_cache == NULL); 177 dnode_cache = kmem_cache_create("dnode_t", 178 sizeof (dnode_t), 179 0, dnode_cons, dnode_dest, NULL, NULL, NULL, 0); 180 kmem_cache_set_move(dnode_cache, dnode_move); 181 } 182 183 void 184 dnode_fini(void) 185 { 186 kmem_cache_destroy(dnode_cache); 187 dnode_cache = NULL; 188 } 189 190 191 #ifdef ZFS_DEBUG 192 void 193 dnode_verify(dnode_t *dn) 194 { 195 int drop_struct_lock = FALSE; 196 197 ASSERT(dn->dn_phys); 198 ASSERT(dn->dn_objset); 199 ASSERT(dn->dn_handle->dnh_dnode == dn); 200 201 ASSERT(DMU_OT_IS_VALID(dn->dn_phys->dn_type)); 202 203 if (!(zfs_flags & ZFS_DEBUG_DNODE_VERIFY)) 204 return; 205 206 if (!RW_WRITE_HELD(&dn->dn_struct_rwlock)) { 207 rw_enter(&dn->dn_struct_rwlock, RW_READER); 208 drop_struct_lock = TRUE; 209 } 210 if (dn->dn_phys->dn_type != DMU_OT_NONE || dn->dn_allocated_txg != 0) { 211 int i; 212 ASSERT3U(dn->dn_indblkshift, >=, 0); 213 ASSERT3U(dn->dn_indblkshift, <=, SPA_MAXBLOCKSHIFT); 214 if (dn->dn_datablkshift) { 215 ASSERT3U(dn->dn_datablkshift, >=, SPA_MINBLOCKSHIFT); 216 ASSERT3U(dn->dn_datablkshift, <=, SPA_MAXBLOCKSHIFT); 217 ASSERT3U(1<<dn->dn_datablkshift, ==, dn->dn_datablksz); 218 } 219 ASSERT3U(dn->dn_nlevels, <=, 30); 220 ASSERT(DMU_OT_IS_VALID(dn->dn_type)); 221 ASSERT3U(dn->dn_nblkptr, >=, 1); 222 ASSERT3U(dn->dn_nblkptr, <=, DN_MAX_NBLKPTR); 223 ASSERT3U(dn->dn_bonuslen, <=, DN_MAX_BONUSLEN); 224 ASSERT3U(dn->dn_datablksz, ==, 225 dn->dn_datablkszsec << SPA_MINBLOCKSHIFT); 226 ASSERT3U(ISP2(dn->dn_datablksz), ==, dn->dn_datablkshift != 0); 227 ASSERT3U((dn->dn_nblkptr - 1) * sizeof (blkptr_t) + 228 dn->dn_bonuslen, <=, DN_MAX_BONUSLEN); 229 for (i = 0; i < TXG_SIZE; i++) { 230 ASSERT3U(dn->dn_next_nlevels[i], <=, dn->dn_nlevels); 231 } 232 } 233 if (dn->dn_phys->dn_type != DMU_OT_NONE) 234 ASSERT3U(dn->dn_phys->dn_nlevels, <=, dn->dn_nlevels); 235 ASSERT(DMU_OBJECT_IS_SPECIAL(dn->dn_object) || dn->dn_dbuf != NULL); 236 if (dn->dn_dbuf != NULL) { 237 ASSERT3P(dn->dn_phys, ==, 238 (dnode_phys_t *)dn->dn_dbuf->db.db_data + 239 (dn->dn_object % (dn->dn_dbuf->db.db_size >> DNODE_SHIFT))); 240 } 241 if (drop_struct_lock) 242 rw_exit(&dn->dn_struct_rwlock); 243 } 244 #endif 245 246 void 247 dnode_byteswap(dnode_phys_t *dnp) 248 { 249 uint64_t *buf64 = (void*)&dnp->dn_blkptr; 250 int i; 251 252 if (dnp->dn_type == DMU_OT_NONE) { 253 bzero(dnp, sizeof (dnode_phys_t)); 254 return; 255 } 256 257 dnp->dn_datablkszsec = BSWAP_16(dnp->dn_datablkszsec); 258 dnp->dn_bonuslen = BSWAP_16(dnp->dn_bonuslen); 259 dnp->dn_maxblkid = BSWAP_64(dnp->dn_maxblkid); 260 dnp->dn_used = BSWAP_64(dnp->dn_used); 261 262 /* 263 * dn_nblkptr is only one byte, so it's OK to read it in either 264 * byte order. We can't read dn_bouslen. 265 */ 266 ASSERT(dnp->dn_indblkshift <= SPA_MAXBLOCKSHIFT); 267 ASSERT(dnp->dn_nblkptr <= DN_MAX_NBLKPTR); 268 for (i = 0; i < dnp->dn_nblkptr * sizeof (blkptr_t)/8; i++) 269 buf64[i] = BSWAP_64(buf64[i]); 270 271 /* 272 * OK to check dn_bonuslen for zero, because it won't matter if 273 * we have the wrong byte order. This is necessary because the 274 * dnode dnode is smaller than a regular dnode. 275 */ 276 if (dnp->dn_bonuslen != 0) { 277 /* 278 * Note that the bonus length calculated here may be 279 * longer than the actual bonus buffer. This is because 280 * we always put the bonus buffer after the last block 281 * pointer (instead of packing it against the end of the 282 * dnode buffer). 283 */ 284 int off = (dnp->dn_nblkptr-1) * sizeof (blkptr_t); 285 size_t len = DN_MAX_BONUSLEN - off; 286 ASSERT(DMU_OT_IS_VALID(dnp->dn_bonustype)); 287 dmu_object_byteswap_t byteswap = 288 DMU_OT_BYTESWAP(dnp->dn_bonustype); 289 dmu_ot_byteswap[byteswap].ob_func(dnp->dn_bonus + off, len); 290 } 291 292 /* Swap SPILL block if we have one */ 293 if (dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) 294 byteswap_uint64_array(&dnp->dn_spill, sizeof (blkptr_t)); 295 296 } 297 298 void 299 dnode_buf_byteswap(void *vbuf, size_t size) 300 { 301 dnode_phys_t *buf = vbuf; 302 int i; 303 304 ASSERT3U(sizeof (dnode_phys_t), ==, (1<<DNODE_SHIFT)); 305 ASSERT((size & (sizeof (dnode_phys_t)-1)) == 0); 306 307 size >>= DNODE_SHIFT; 308 for (i = 0; i < size; i++) { 309 dnode_byteswap(buf); 310 buf++; 311 } 312 } 313 314 static int 315 free_range_compar(const void *node1, const void *node2) 316 { 317 const free_range_t *rp1 = node1; 318 const free_range_t *rp2 = node2; 319 320 if (rp1->fr_blkid < rp2->fr_blkid) 321 return (-1); 322 else if (rp1->fr_blkid > rp2->fr_blkid) 323 return (1); 324 else return (0); 325 } 326 327 void 328 dnode_setbonuslen(dnode_t *dn, int newsize, dmu_tx_t *tx) 329 { 330 ASSERT3U(refcount_count(&dn->dn_holds), >=, 1); 331 332 dnode_setdirty(dn, tx); 333 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 334 ASSERT3U(newsize, <=, DN_MAX_BONUSLEN - 335 (dn->dn_nblkptr-1) * sizeof (blkptr_t)); 336 dn->dn_bonuslen = newsize; 337 if (newsize == 0) 338 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = DN_ZERO_BONUSLEN; 339 else 340 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = dn->dn_bonuslen; 341 rw_exit(&dn->dn_struct_rwlock); 342 } 343 344 void 345 dnode_setbonus_type(dnode_t *dn, dmu_object_type_t newtype, dmu_tx_t *tx) 346 { 347 ASSERT3U(refcount_count(&dn->dn_holds), >=, 1); 348 dnode_setdirty(dn, tx); 349 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 350 dn->dn_bonustype = newtype; 351 dn->dn_next_bonustype[tx->tx_txg & TXG_MASK] = dn->dn_bonustype; 352 rw_exit(&dn->dn_struct_rwlock); 353 } 354 355 void 356 dnode_rm_spill(dnode_t *dn, dmu_tx_t *tx) 357 { 358 ASSERT3U(refcount_count(&dn->dn_holds), >=, 1); 359 ASSERT(RW_WRITE_HELD(&dn->dn_struct_rwlock)); 360 dnode_setdirty(dn, tx); 361 dn->dn_rm_spillblk[tx->tx_txg&TXG_MASK] = DN_KILL_SPILLBLK; 362 dn->dn_have_spill = B_FALSE; 363 } 364 365 static void 366 dnode_setdblksz(dnode_t *dn, int size) 367 { 368 ASSERT0(P2PHASE(size, SPA_MINBLOCKSIZE)); 369 ASSERT3U(size, <=, SPA_MAXBLOCKSIZE); 370 ASSERT3U(size, >=, SPA_MINBLOCKSIZE); 371 ASSERT3U(size >> SPA_MINBLOCKSHIFT, <, 372 1<<(sizeof (dn->dn_phys->dn_datablkszsec) * 8)); 373 dn->dn_datablksz = size; 374 dn->dn_datablkszsec = size >> SPA_MINBLOCKSHIFT; 375 dn->dn_datablkshift = ISP2(size) ? highbit(size - 1) : 0; 376 } 377 378 static dnode_t * 379 dnode_create(objset_t *os, dnode_phys_t *dnp, dmu_buf_impl_t *db, 380 uint64_t object, dnode_handle_t *dnh) 381 { 382 dnode_t *dn = kmem_cache_alloc(dnode_cache, KM_SLEEP); 383 384 ASSERT(!POINTER_IS_VALID(dn->dn_objset)); 385 dn->dn_moved = 0; 386 387 /* 388 * Defer setting dn_objset until the dnode is ready to be a candidate 389 * for the dnode_move() callback. 390 */ 391 dn->dn_object = object; 392 dn->dn_dbuf = db; 393 dn->dn_handle = dnh; 394 dn->dn_phys = dnp; 395 396 if (dnp->dn_datablkszsec) { 397 dnode_setdblksz(dn, dnp->dn_datablkszsec << SPA_MINBLOCKSHIFT); 398 } else { 399 dn->dn_datablksz = 0; 400 dn->dn_datablkszsec = 0; 401 dn->dn_datablkshift = 0; 402 } 403 dn->dn_indblkshift = dnp->dn_indblkshift; 404 dn->dn_nlevels = dnp->dn_nlevels; 405 dn->dn_type = dnp->dn_type; 406 dn->dn_nblkptr = dnp->dn_nblkptr; 407 dn->dn_checksum = dnp->dn_checksum; 408 dn->dn_compress = dnp->dn_compress; 409 dn->dn_bonustype = dnp->dn_bonustype; 410 dn->dn_bonuslen = dnp->dn_bonuslen; 411 dn->dn_maxblkid = dnp->dn_maxblkid; 412 dn->dn_have_spill = ((dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) != 0); 413 dn->dn_id_flags = 0; 414 415 dmu_zfetch_init(&dn->dn_zfetch, dn); 416 417 ASSERT(DMU_OT_IS_VALID(dn->dn_phys->dn_type)); 418 419 mutex_enter(&os->os_lock); 420 list_insert_head(&os->os_dnodes, dn); 421 membar_producer(); 422 /* 423 * Everything else must be valid before assigning dn_objset makes the 424 * dnode eligible for dnode_move(). 425 */ 426 dn->dn_objset = os; 427 mutex_exit(&os->os_lock); 428 429 arc_space_consume(sizeof (dnode_t), ARC_SPACE_OTHER); 430 return (dn); 431 } 432 433 /* 434 * Caller must be holding the dnode handle, which is released upon return. 435 */ 436 static void 437 dnode_destroy(dnode_t *dn) 438 { 439 objset_t *os = dn->dn_objset; 440 441 ASSERT((dn->dn_id_flags & DN_ID_NEW_EXIST) == 0); 442 443 mutex_enter(&os->os_lock); 444 POINTER_INVALIDATE(&dn->dn_objset); 445 list_remove(&os->os_dnodes, dn); 446 mutex_exit(&os->os_lock); 447 448 /* the dnode can no longer move, so we can release the handle */ 449 zrl_remove(&dn->dn_handle->dnh_zrlock); 450 451 dn->dn_allocated_txg = 0; 452 dn->dn_free_txg = 0; 453 dn->dn_assigned_txg = 0; 454 455 dn->dn_dirtyctx = 0; 456 if (dn->dn_dirtyctx_firstset != NULL) { 457 kmem_free(dn->dn_dirtyctx_firstset, 1); 458 dn->dn_dirtyctx_firstset = NULL; 459 } 460 if (dn->dn_bonus != NULL) { 461 mutex_enter(&dn->dn_bonus->db_mtx); 462 dbuf_evict(dn->dn_bonus); 463 dn->dn_bonus = NULL; 464 } 465 dn->dn_zio = NULL; 466 467 dn->dn_have_spill = B_FALSE; 468 dn->dn_oldused = 0; 469 dn->dn_oldflags = 0; 470 dn->dn_olduid = 0; 471 dn->dn_oldgid = 0; 472 dn->dn_newuid = 0; 473 dn->dn_newgid = 0; 474 dn->dn_id_flags = 0; 475 476 dmu_zfetch_rele(&dn->dn_zfetch); 477 kmem_cache_free(dnode_cache, dn); 478 arc_space_return(sizeof (dnode_t), ARC_SPACE_OTHER); 479 } 480 481 void 482 dnode_allocate(dnode_t *dn, dmu_object_type_t ot, int blocksize, int ibs, 483 dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx) 484 { 485 int i; 486 487 if (blocksize == 0) 488 blocksize = 1 << zfs_default_bs; 489 else if (blocksize > SPA_MAXBLOCKSIZE) 490 blocksize = SPA_MAXBLOCKSIZE; 491 else 492 blocksize = P2ROUNDUP(blocksize, SPA_MINBLOCKSIZE); 493 494 if (ibs == 0) 495 ibs = zfs_default_ibs; 496 497 ibs = MIN(MAX(ibs, DN_MIN_INDBLKSHIFT), DN_MAX_INDBLKSHIFT); 498 499 dprintf("os=%p obj=%llu txg=%llu blocksize=%d ibs=%d\n", dn->dn_objset, 500 dn->dn_object, tx->tx_txg, blocksize, ibs); 501 502 ASSERT(dn->dn_type == DMU_OT_NONE); 503 ASSERT(bcmp(dn->dn_phys, &dnode_phys_zero, sizeof (dnode_phys_t)) == 0); 504 ASSERT(dn->dn_phys->dn_type == DMU_OT_NONE); 505 ASSERT(ot != DMU_OT_NONE); 506 ASSERT(DMU_OT_IS_VALID(ot)); 507 ASSERT((bonustype == DMU_OT_NONE && bonuslen == 0) || 508 (bonustype == DMU_OT_SA && bonuslen == 0) || 509 (bonustype != DMU_OT_NONE && bonuslen != 0)); 510 ASSERT(DMU_OT_IS_VALID(bonustype)); 511 ASSERT3U(bonuslen, <=, DN_MAX_BONUSLEN); 512 ASSERT(dn->dn_type == DMU_OT_NONE); 513 ASSERT0(dn->dn_maxblkid); 514 ASSERT0(dn->dn_allocated_txg); 515 ASSERT0(dn->dn_assigned_txg); 516 ASSERT(refcount_is_zero(&dn->dn_tx_holds)); 517 ASSERT3U(refcount_count(&dn->dn_holds), <=, 1); 518 ASSERT3P(list_head(&dn->dn_dbufs), ==, NULL); 519 520 for (i = 0; i < TXG_SIZE; i++) { 521 ASSERT0(dn->dn_next_nblkptr[i]); 522 ASSERT0(dn->dn_next_nlevels[i]); 523 ASSERT0(dn->dn_next_indblkshift[i]); 524 ASSERT0(dn->dn_next_bonuslen[i]); 525 ASSERT0(dn->dn_next_bonustype[i]); 526 ASSERT0(dn->dn_rm_spillblk[i]); 527 ASSERT0(dn->dn_next_blksz[i]); 528 ASSERT(!list_link_active(&dn->dn_dirty_link[i])); 529 ASSERT3P(list_head(&dn->dn_dirty_records[i]), ==, NULL); 530 ASSERT0(avl_numnodes(&dn->dn_ranges[i])); 531 } 532 533 dn->dn_type = ot; 534 dnode_setdblksz(dn, blocksize); 535 dn->dn_indblkshift = ibs; 536 dn->dn_nlevels = 1; 537 if (bonustype == DMU_OT_SA) /* Maximize bonus space for SA */ 538 dn->dn_nblkptr = 1; 539 else 540 dn->dn_nblkptr = 1 + 541 ((DN_MAX_BONUSLEN - bonuslen) >> SPA_BLKPTRSHIFT); 542 dn->dn_bonustype = bonustype; 543 dn->dn_bonuslen = bonuslen; 544 dn->dn_checksum = ZIO_CHECKSUM_INHERIT; 545 dn->dn_compress = ZIO_COMPRESS_INHERIT; 546 dn->dn_dirtyctx = 0; 547 548 dn->dn_free_txg = 0; 549 if (dn->dn_dirtyctx_firstset) { 550 kmem_free(dn->dn_dirtyctx_firstset, 1); 551 dn->dn_dirtyctx_firstset = NULL; 552 } 553 554 dn->dn_allocated_txg = tx->tx_txg; 555 dn->dn_id_flags = 0; 556 557 dnode_setdirty(dn, tx); 558 dn->dn_next_indblkshift[tx->tx_txg & TXG_MASK] = ibs; 559 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = dn->dn_bonuslen; 560 dn->dn_next_bonustype[tx->tx_txg & TXG_MASK] = dn->dn_bonustype; 561 dn->dn_next_blksz[tx->tx_txg & TXG_MASK] = dn->dn_datablksz; 562 } 563 564 void 565 dnode_reallocate(dnode_t *dn, dmu_object_type_t ot, int blocksize, 566 dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx) 567 { 568 int nblkptr; 569 570 ASSERT3U(blocksize, >=, SPA_MINBLOCKSIZE); 571 ASSERT3U(blocksize, <=, SPA_MAXBLOCKSIZE); 572 ASSERT0(blocksize % SPA_MINBLOCKSIZE); 573 ASSERT(dn->dn_object != DMU_META_DNODE_OBJECT || dmu_tx_private_ok(tx)); 574 ASSERT(tx->tx_txg != 0); 575 ASSERT((bonustype == DMU_OT_NONE && bonuslen == 0) || 576 (bonustype != DMU_OT_NONE && bonuslen != 0) || 577 (bonustype == DMU_OT_SA && bonuslen == 0)); 578 ASSERT(DMU_OT_IS_VALID(bonustype)); 579 ASSERT3U(bonuslen, <=, DN_MAX_BONUSLEN); 580 581 /* clean up any unreferenced dbufs */ 582 dnode_evict_dbufs(dn); 583 584 dn->dn_id_flags = 0; 585 586 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 587 dnode_setdirty(dn, tx); 588 if (dn->dn_datablksz != blocksize) { 589 /* change blocksize */ 590 ASSERT(dn->dn_maxblkid == 0 && 591 (BP_IS_HOLE(&dn->dn_phys->dn_blkptr[0]) || 592 dnode_block_freed(dn, 0))); 593 dnode_setdblksz(dn, blocksize); 594 dn->dn_next_blksz[tx->tx_txg&TXG_MASK] = blocksize; 595 } 596 if (dn->dn_bonuslen != bonuslen) 597 dn->dn_next_bonuslen[tx->tx_txg&TXG_MASK] = bonuslen; 598 599 if (bonustype == DMU_OT_SA) /* Maximize bonus space for SA */ 600 nblkptr = 1; 601 else 602 nblkptr = 1 + ((DN_MAX_BONUSLEN - bonuslen) >> SPA_BLKPTRSHIFT); 603 if (dn->dn_bonustype != bonustype) 604 dn->dn_next_bonustype[tx->tx_txg&TXG_MASK] = bonustype; 605 if (dn->dn_nblkptr != nblkptr) 606 dn->dn_next_nblkptr[tx->tx_txg&TXG_MASK] = nblkptr; 607 if (dn->dn_phys->dn_flags & DNODE_FLAG_SPILL_BLKPTR) { 608 dbuf_rm_spill(dn, tx); 609 dnode_rm_spill(dn, tx); 610 } 611 rw_exit(&dn->dn_struct_rwlock); 612 613 /* change type */ 614 dn->dn_type = ot; 615 616 /* change bonus size and type */ 617 mutex_enter(&dn->dn_mtx); 618 dn->dn_bonustype = bonustype; 619 dn->dn_bonuslen = bonuslen; 620 dn->dn_nblkptr = nblkptr; 621 dn->dn_checksum = ZIO_CHECKSUM_INHERIT; 622 dn->dn_compress = ZIO_COMPRESS_INHERIT; 623 ASSERT3U(dn->dn_nblkptr, <=, DN_MAX_NBLKPTR); 624 625 /* fix up the bonus db_size */ 626 if (dn->dn_bonus) { 627 dn->dn_bonus->db.db_size = 628 DN_MAX_BONUSLEN - (dn->dn_nblkptr-1) * sizeof (blkptr_t); 629 ASSERT(dn->dn_bonuslen <= dn->dn_bonus->db.db_size); 630 } 631 632 dn->dn_allocated_txg = tx->tx_txg; 633 mutex_exit(&dn->dn_mtx); 634 } 635 636 #ifdef DNODE_STATS 637 static struct { 638 uint64_t dms_dnode_invalid; 639 uint64_t dms_dnode_recheck1; 640 uint64_t dms_dnode_recheck2; 641 uint64_t dms_dnode_special; 642 uint64_t dms_dnode_handle; 643 uint64_t dms_dnode_rwlock; 644 uint64_t dms_dnode_active; 645 } dnode_move_stats; 646 #endif /* DNODE_STATS */ 647 648 static void 649 dnode_move_impl(dnode_t *odn, dnode_t *ndn) 650 { 651 int i; 652 653 ASSERT(!RW_LOCK_HELD(&odn->dn_struct_rwlock)); 654 ASSERT(MUTEX_NOT_HELD(&odn->dn_mtx)); 655 ASSERT(MUTEX_NOT_HELD(&odn->dn_dbufs_mtx)); 656 ASSERT(!RW_LOCK_HELD(&odn->dn_zfetch.zf_rwlock)); 657 658 /* Copy fields. */ 659 ndn->dn_objset = odn->dn_objset; 660 ndn->dn_object = odn->dn_object; 661 ndn->dn_dbuf = odn->dn_dbuf; 662 ndn->dn_handle = odn->dn_handle; 663 ndn->dn_phys = odn->dn_phys; 664 ndn->dn_type = odn->dn_type; 665 ndn->dn_bonuslen = odn->dn_bonuslen; 666 ndn->dn_bonustype = odn->dn_bonustype; 667 ndn->dn_nblkptr = odn->dn_nblkptr; 668 ndn->dn_checksum = odn->dn_checksum; 669 ndn->dn_compress = odn->dn_compress; 670 ndn->dn_nlevels = odn->dn_nlevels; 671 ndn->dn_indblkshift = odn->dn_indblkshift; 672 ndn->dn_datablkshift = odn->dn_datablkshift; 673 ndn->dn_datablkszsec = odn->dn_datablkszsec; 674 ndn->dn_datablksz = odn->dn_datablksz; 675 ndn->dn_maxblkid = odn->dn_maxblkid; 676 bcopy(&odn->dn_next_nblkptr[0], &ndn->dn_next_nblkptr[0], 677 sizeof (odn->dn_next_nblkptr)); 678 bcopy(&odn->dn_next_nlevels[0], &ndn->dn_next_nlevels[0], 679 sizeof (odn->dn_next_nlevels)); 680 bcopy(&odn->dn_next_indblkshift[0], &ndn->dn_next_indblkshift[0], 681 sizeof (odn->dn_next_indblkshift)); 682 bcopy(&odn->dn_next_bonustype[0], &ndn->dn_next_bonustype[0], 683 sizeof (odn->dn_next_bonustype)); 684 bcopy(&odn->dn_rm_spillblk[0], &ndn->dn_rm_spillblk[0], 685 sizeof (odn->dn_rm_spillblk)); 686 bcopy(&odn->dn_next_bonuslen[0], &ndn->dn_next_bonuslen[0], 687 sizeof (odn->dn_next_bonuslen)); 688 bcopy(&odn->dn_next_blksz[0], &ndn->dn_next_blksz[0], 689 sizeof (odn->dn_next_blksz)); 690 for (i = 0; i < TXG_SIZE; i++) { 691 list_move_tail(&ndn->dn_dirty_records[i], 692 &odn->dn_dirty_records[i]); 693 } 694 bcopy(&odn->dn_ranges[0], &ndn->dn_ranges[0], sizeof (odn->dn_ranges)); 695 ndn->dn_allocated_txg = odn->dn_allocated_txg; 696 ndn->dn_free_txg = odn->dn_free_txg; 697 ndn->dn_assigned_txg = odn->dn_assigned_txg; 698 ndn->dn_dirtyctx = odn->dn_dirtyctx; 699 ndn->dn_dirtyctx_firstset = odn->dn_dirtyctx_firstset; 700 ASSERT(refcount_count(&odn->dn_tx_holds) == 0); 701 refcount_transfer(&ndn->dn_holds, &odn->dn_holds); 702 ASSERT(list_is_empty(&ndn->dn_dbufs)); 703 list_move_tail(&ndn->dn_dbufs, &odn->dn_dbufs); 704 ndn->dn_dbufs_count = odn->dn_dbufs_count; 705 ndn->dn_bonus = odn->dn_bonus; 706 ndn->dn_have_spill = odn->dn_have_spill; 707 ndn->dn_zio = odn->dn_zio; 708 ndn->dn_oldused = odn->dn_oldused; 709 ndn->dn_oldflags = odn->dn_oldflags; 710 ndn->dn_olduid = odn->dn_olduid; 711 ndn->dn_oldgid = odn->dn_oldgid; 712 ndn->dn_newuid = odn->dn_newuid; 713 ndn->dn_newgid = odn->dn_newgid; 714 ndn->dn_id_flags = odn->dn_id_flags; 715 dmu_zfetch_init(&ndn->dn_zfetch, NULL); 716 list_move_tail(&ndn->dn_zfetch.zf_stream, &odn->dn_zfetch.zf_stream); 717 ndn->dn_zfetch.zf_dnode = odn->dn_zfetch.zf_dnode; 718 ndn->dn_zfetch.zf_stream_cnt = odn->dn_zfetch.zf_stream_cnt; 719 ndn->dn_zfetch.zf_alloc_fail = odn->dn_zfetch.zf_alloc_fail; 720 721 /* 722 * Update back pointers. Updating the handle fixes the back pointer of 723 * every descendant dbuf as well as the bonus dbuf. 724 */ 725 ASSERT(ndn->dn_handle->dnh_dnode == odn); 726 ndn->dn_handle->dnh_dnode = ndn; 727 if (ndn->dn_zfetch.zf_dnode == odn) { 728 ndn->dn_zfetch.zf_dnode = ndn; 729 } 730 731 /* 732 * Invalidate the original dnode by clearing all of its back pointers. 733 */ 734 odn->dn_dbuf = NULL; 735 odn->dn_handle = NULL; 736 list_create(&odn->dn_dbufs, sizeof (dmu_buf_impl_t), 737 offsetof(dmu_buf_impl_t, db_link)); 738 odn->dn_dbufs_count = 0; 739 odn->dn_bonus = NULL; 740 odn->dn_zfetch.zf_dnode = NULL; 741 742 /* 743 * Set the low bit of the objset pointer to ensure that dnode_move() 744 * recognizes the dnode as invalid in any subsequent callback. 745 */ 746 POINTER_INVALIDATE(&odn->dn_objset); 747 748 /* 749 * Satisfy the destructor. 750 */ 751 for (i = 0; i < TXG_SIZE; i++) { 752 list_create(&odn->dn_dirty_records[i], 753 sizeof (dbuf_dirty_record_t), 754 offsetof(dbuf_dirty_record_t, dr_dirty_node)); 755 odn->dn_ranges[i].avl_root = NULL; 756 odn->dn_ranges[i].avl_numnodes = 0; 757 odn->dn_next_nlevels[i] = 0; 758 odn->dn_next_indblkshift[i] = 0; 759 odn->dn_next_bonustype[i] = 0; 760 odn->dn_rm_spillblk[i] = 0; 761 odn->dn_next_bonuslen[i] = 0; 762 odn->dn_next_blksz[i] = 0; 763 } 764 odn->dn_allocated_txg = 0; 765 odn->dn_free_txg = 0; 766 odn->dn_assigned_txg = 0; 767 odn->dn_dirtyctx = 0; 768 odn->dn_dirtyctx_firstset = NULL; 769 odn->dn_have_spill = B_FALSE; 770 odn->dn_zio = NULL; 771 odn->dn_oldused = 0; 772 odn->dn_oldflags = 0; 773 odn->dn_olduid = 0; 774 odn->dn_oldgid = 0; 775 odn->dn_newuid = 0; 776 odn->dn_newgid = 0; 777 odn->dn_id_flags = 0; 778 779 /* 780 * Mark the dnode. 781 */ 782 ndn->dn_moved = 1; 783 odn->dn_moved = (uint8_t)-1; 784 } 785 786 #ifdef _KERNEL 787 /*ARGSUSED*/ 788 static kmem_cbrc_t 789 dnode_move(void *buf, void *newbuf, size_t size, void *arg) 790 { 791 dnode_t *odn = buf, *ndn = newbuf; 792 objset_t *os; 793 int64_t refcount; 794 uint32_t dbufs; 795 796 /* 797 * The dnode is on the objset's list of known dnodes if the objset 798 * pointer is valid. We set the low bit of the objset pointer when 799 * freeing the dnode to invalidate it, and the memory patterns written 800 * by kmem (baddcafe and deadbeef) set at least one of the two low bits. 801 * A newly created dnode sets the objset pointer last of all to indicate 802 * that the dnode is known and in a valid state to be moved by this 803 * function. 804 */ 805 os = odn->dn_objset; 806 if (!POINTER_IS_VALID(os)) { 807 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_invalid); 808 return (KMEM_CBRC_DONT_KNOW); 809 } 810 811 /* 812 * Ensure that the objset does not go away during the move. 813 */ 814 rw_enter(&os_lock, RW_WRITER); 815 if (os != odn->dn_objset) { 816 rw_exit(&os_lock); 817 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_recheck1); 818 return (KMEM_CBRC_DONT_KNOW); 819 } 820 821 /* 822 * If the dnode is still valid, then so is the objset. We know that no 823 * valid objset can be freed while we hold os_lock, so we can safely 824 * ensure that the objset remains in use. 825 */ 826 mutex_enter(&os->os_lock); 827 828 /* 829 * Recheck the objset pointer in case the dnode was removed just before 830 * acquiring the lock. 831 */ 832 if (os != odn->dn_objset) { 833 mutex_exit(&os->os_lock); 834 rw_exit(&os_lock); 835 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_recheck2); 836 return (KMEM_CBRC_DONT_KNOW); 837 } 838 839 /* 840 * At this point we know that as long as we hold os->os_lock, the dnode 841 * cannot be freed and fields within the dnode can be safely accessed. 842 * The objset listing this dnode cannot go away as long as this dnode is 843 * on its list. 844 */ 845 rw_exit(&os_lock); 846 if (DMU_OBJECT_IS_SPECIAL(odn->dn_object)) { 847 mutex_exit(&os->os_lock); 848 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_special); 849 return (KMEM_CBRC_NO); 850 } 851 ASSERT(odn->dn_dbuf != NULL); /* only "special" dnodes have no parent */ 852 853 /* 854 * Lock the dnode handle to prevent the dnode from obtaining any new 855 * holds. This also prevents the descendant dbufs and the bonus dbuf 856 * from accessing the dnode, so that we can discount their holds. The 857 * handle is safe to access because we know that while the dnode cannot 858 * go away, neither can its handle. Once we hold dnh_zrlock, we can 859 * safely move any dnode referenced only by dbufs. 860 */ 861 if (!zrl_tryenter(&odn->dn_handle->dnh_zrlock)) { 862 mutex_exit(&os->os_lock); 863 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_handle); 864 return (KMEM_CBRC_LATER); 865 } 866 867 /* 868 * Ensure a consistent view of the dnode's holds and the dnode's dbufs. 869 * We need to guarantee that there is a hold for every dbuf in order to 870 * determine whether the dnode is actively referenced. Falsely matching 871 * a dbuf to an active hold would lead to an unsafe move. It's possible 872 * that a thread already having an active dnode hold is about to add a 873 * dbuf, and we can't compare hold and dbuf counts while the add is in 874 * progress. 875 */ 876 if (!rw_tryenter(&odn->dn_struct_rwlock, RW_WRITER)) { 877 zrl_exit(&odn->dn_handle->dnh_zrlock); 878 mutex_exit(&os->os_lock); 879 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_rwlock); 880 return (KMEM_CBRC_LATER); 881 } 882 883 /* 884 * A dbuf may be removed (evicted) without an active dnode hold. In that 885 * case, the dbuf count is decremented under the handle lock before the 886 * dbuf's hold is released. This order ensures that if we count the hold 887 * after the dbuf is removed but before its hold is released, we will 888 * treat the unmatched hold as active and exit safely. If we count the 889 * hold before the dbuf is removed, the hold is discounted, and the 890 * removal is blocked until the move completes. 891 */ 892 refcount = refcount_count(&odn->dn_holds); 893 ASSERT(refcount >= 0); 894 dbufs = odn->dn_dbufs_count; 895 896 /* We can't have more dbufs than dnode holds. */ 897 ASSERT3U(dbufs, <=, refcount); 898 DTRACE_PROBE3(dnode__move, dnode_t *, odn, int64_t, refcount, 899 uint32_t, dbufs); 900 901 if (refcount > dbufs) { 902 rw_exit(&odn->dn_struct_rwlock); 903 zrl_exit(&odn->dn_handle->dnh_zrlock); 904 mutex_exit(&os->os_lock); 905 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_active); 906 return (KMEM_CBRC_LATER); 907 } 908 909 rw_exit(&odn->dn_struct_rwlock); 910 911 /* 912 * At this point we know that anyone with a hold on the dnode is not 913 * actively referencing it. The dnode is known and in a valid state to 914 * move. We're holding the locks needed to execute the critical section. 915 */ 916 dnode_move_impl(odn, ndn); 917 918 list_link_replace(&odn->dn_link, &ndn->dn_link); 919 /* If the dnode was safe to move, the refcount cannot have changed. */ 920 ASSERT(refcount == refcount_count(&ndn->dn_holds)); 921 ASSERT(dbufs == ndn->dn_dbufs_count); 922 zrl_exit(&ndn->dn_handle->dnh_zrlock); /* handle has moved */ 923 mutex_exit(&os->os_lock); 924 925 return (KMEM_CBRC_YES); 926 } 927 #endif /* _KERNEL */ 928 929 void 930 dnode_special_close(dnode_handle_t *dnh) 931 { 932 dnode_t *dn = dnh->dnh_dnode; 933 934 /* 935 * Wait for final references to the dnode to clear. This can 936 * only happen if the arc is asyncronously evicting state that 937 * has a hold on this dnode while we are trying to evict this 938 * dnode. 939 */ 940 while (refcount_count(&dn->dn_holds) > 0) 941 delay(1); 942 zrl_add(&dnh->dnh_zrlock); 943 dnode_destroy(dn); /* implicit zrl_remove() */ 944 zrl_destroy(&dnh->dnh_zrlock); 945 dnh->dnh_dnode = NULL; 946 } 947 948 dnode_t * 949 dnode_special_open(objset_t *os, dnode_phys_t *dnp, uint64_t object, 950 dnode_handle_t *dnh) 951 { 952 dnode_t *dn = dnode_create(os, dnp, NULL, object, dnh); 953 dnh->dnh_dnode = dn; 954 zrl_init(&dnh->dnh_zrlock); 955 DNODE_VERIFY(dn); 956 return (dn); 957 } 958 959 static void 960 dnode_buf_pageout(dmu_buf_t *db, void *arg) 961 { 962 dnode_children_t *children_dnodes = arg; 963 int i; 964 int epb = db->db_size >> DNODE_SHIFT; 965 966 ASSERT(epb == children_dnodes->dnc_count); 967 968 for (i = 0; i < epb; i++) { 969 dnode_handle_t *dnh = &children_dnodes->dnc_children[i]; 970 dnode_t *dn; 971 972 /* 973 * The dnode handle lock guards against the dnode moving to 974 * another valid address, so there is no need here to guard 975 * against changes to or from NULL. 976 */ 977 if (dnh->dnh_dnode == NULL) { 978 zrl_destroy(&dnh->dnh_zrlock); 979 continue; 980 } 981 982 zrl_add(&dnh->dnh_zrlock); 983 dn = dnh->dnh_dnode; 984 /* 985 * If there are holds on this dnode, then there should 986 * be holds on the dnode's containing dbuf as well; thus 987 * it wouldn't be eligible for eviction and this function 988 * would not have been called. 989 */ 990 ASSERT(refcount_is_zero(&dn->dn_holds)); 991 ASSERT(refcount_is_zero(&dn->dn_tx_holds)); 992 993 dnode_destroy(dn); /* implicit zrl_remove() */ 994 zrl_destroy(&dnh->dnh_zrlock); 995 dnh->dnh_dnode = NULL; 996 } 997 kmem_free(children_dnodes, sizeof (dnode_children_t) + 998 (epb - 1) * sizeof (dnode_handle_t)); 999 } 1000 1001 /* 1002 * errors: 1003 * EINVAL - invalid object number. 1004 * EIO - i/o error. 1005 * succeeds even for free dnodes. 1006 */ 1007 int 1008 dnode_hold_impl(objset_t *os, uint64_t object, int flag, 1009 void *tag, dnode_t **dnp) 1010 { 1011 int epb, idx, err; 1012 int drop_struct_lock = FALSE; 1013 int type; 1014 uint64_t blk; 1015 dnode_t *mdn, *dn; 1016 dmu_buf_impl_t *db; 1017 dnode_children_t *children_dnodes; 1018 dnode_handle_t *dnh; 1019 1020 /* 1021 * If you are holding the spa config lock as writer, you shouldn't 1022 * be asking the DMU to do *anything* unless it's the root pool 1023 * which may require us to read from the root filesystem while 1024 * holding some (not all) of the locks as writer. 1025 */ 1026 ASSERT(spa_config_held(os->os_spa, SCL_ALL, RW_WRITER) == 0 || 1027 (spa_is_root(os->os_spa) && 1028 spa_config_held(os->os_spa, SCL_STATE, RW_WRITER))); 1029 1030 if (object == DMU_USERUSED_OBJECT || object == DMU_GROUPUSED_OBJECT) { 1031 dn = (object == DMU_USERUSED_OBJECT) ? 1032 DMU_USERUSED_DNODE(os) : DMU_GROUPUSED_DNODE(os); 1033 if (dn == NULL) 1034 return (SET_ERROR(ENOENT)); 1035 type = dn->dn_type; 1036 if ((flag & DNODE_MUST_BE_ALLOCATED) && type == DMU_OT_NONE) 1037 return (SET_ERROR(ENOENT)); 1038 if ((flag & DNODE_MUST_BE_FREE) && type != DMU_OT_NONE) 1039 return (SET_ERROR(EEXIST)); 1040 DNODE_VERIFY(dn); 1041 (void) refcount_add(&dn->dn_holds, tag); 1042 *dnp = dn; 1043 return (0); 1044 } 1045 1046 if (object == 0 || object >= DN_MAX_OBJECT) 1047 return (SET_ERROR(EINVAL)); 1048 1049 mdn = DMU_META_DNODE(os); 1050 ASSERT(mdn->dn_object == DMU_META_DNODE_OBJECT); 1051 1052 DNODE_VERIFY(mdn); 1053 1054 if (!RW_WRITE_HELD(&mdn->dn_struct_rwlock)) { 1055 rw_enter(&mdn->dn_struct_rwlock, RW_READER); 1056 drop_struct_lock = TRUE; 1057 } 1058 1059 blk = dbuf_whichblock(mdn, object * sizeof (dnode_phys_t)); 1060 1061 db = dbuf_hold(mdn, blk, FTAG); 1062 if (drop_struct_lock) 1063 rw_exit(&mdn->dn_struct_rwlock); 1064 if (db == NULL) 1065 return (SET_ERROR(EIO)); 1066 err = dbuf_read(db, NULL, DB_RF_CANFAIL); 1067 if (err) { 1068 dbuf_rele(db, FTAG); 1069 return (err); 1070 } 1071 1072 ASSERT3U(db->db.db_size, >=, 1<<DNODE_SHIFT); 1073 epb = db->db.db_size >> DNODE_SHIFT; 1074 1075 idx = object & (epb-1); 1076 1077 ASSERT(DB_DNODE(db)->dn_type == DMU_OT_DNODE); 1078 children_dnodes = dmu_buf_get_user(&db->db); 1079 if (children_dnodes == NULL) { 1080 int i; 1081 dnode_children_t *winner; 1082 children_dnodes = kmem_alloc(sizeof (dnode_children_t) + 1083 (epb - 1) * sizeof (dnode_handle_t), KM_SLEEP); 1084 children_dnodes->dnc_count = epb; 1085 dnh = &children_dnodes->dnc_children[0]; 1086 for (i = 0; i < epb; i++) { 1087 zrl_init(&dnh[i].dnh_zrlock); 1088 dnh[i].dnh_dnode = NULL; 1089 } 1090 if (winner = dmu_buf_set_user(&db->db, children_dnodes, NULL, 1091 dnode_buf_pageout)) { 1092 kmem_free(children_dnodes, sizeof (dnode_children_t) + 1093 (epb - 1) * sizeof (dnode_handle_t)); 1094 children_dnodes = winner; 1095 } 1096 } 1097 ASSERT(children_dnodes->dnc_count == epb); 1098 1099 dnh = &children_dnodes->dnc_children[idx]; 1100 zrl_add(&dnh->dnh_zrlock); 1101 if ((dn = dnh->dnh_dnode) == NULL) { 1102 dnode_phys_t *phys = (dnode_phys_t *)db->db.db_data+idx; 1103 dnode_t *winner; 1104 1105 dn = dnode_create(os, phys, db, object, dnh); 1106 winner = atomic_cas_ptr(&dnh->dnh_dnode, NULL, dn); 1107 if (winner != NULL) { 1108 zrl_add(&dnh->dnh_zrlock); 1109 dnode_destroy(dn); /* implicit zrl_remove() */ 1110 dn = winner; 1111 } 1112 } 1113 1114 mutex_enter(&dn->dn_mtx); 1115 type = dn->dn_type; 1116 if (dn->dn_free_txg || 1117 ((flag & DNODE_MUST_BE_ALLOCATED) && type == DMU_OT_NONE) || 1118 ((flag & DNODE_MUST_BE_FREE) && 1119 (type != DMU_OT_NONE || !refcount_is_zero(&dn->dn_holds)))) { 1120 mutex_exit(&dn->dn_mtx); 1121 zrl_remove(&dnh->dnh_zrlock); 1122 dbuf_rele(db, FTAG); 1123 return (type == DMU_OT_NONE ? ENOENT : EEXIST); 1124 } 1125 mutex_exit(&dn->dn_mtx); 1126 1127 if (refcount_add(&dn->dn_holds, tag) == 1) 1128 dbuf_add_ref(db, dnh); 1129 /* Now we can rely on the hold to prevent the dnode from moving. */ 1130 zrl_remove(&dnh->dnh_zrlock); 1131 1132 DNODE_VERIFY(dn); 1133 ASSERT3P(dn->dn_dbuf, ==, db); 1134 ASSERT3U(dn->dn_object, ==, object); 1135 dbuf_rele(db, FTAG); 1136 1137 *dnp = dn; 1138 return (0); 1139 } 1140 1141 /* 1142 * Return held dnode if the object is allocated, NULL if not. 1143 */ 1144 int 1145 dnode_hold(objset_t *os, uint64_t object, void *tag, dnode_t **dnp) 1146 { 1147 return (dnode_hold_impl(os, object, DNODE_MUST_BE_ALLOCATED, tag, dnp)); 1148 } 1149 1150 /* 1151 * Can only add a reference if there is already at least one 1152 * reference on the dnode. Returns FALSE if unable to add a 1153 * new reference. 1154 */ 1155 boolean_t 1156 dnode_add_ref(dnode_t *dn, void *tag) 1157 { 1158 mutex_enter(&dn->dn_mtx); 1159 if (refcount_is_zero(&dn->dn_holds)) { 1160 mutex_exit(&dn->dn_mtx); 1161 return (FALSE); 1162 } 1163 VERIFY(1 < refcount_add(&dn->dn_holds, tag)); 1164 mutex_exit(&dn->dn_mtx); 1165 return (TRUE); 1166 } 1167 1168 void 1169 dnode_rele(dnode_t *dn, void *tag) 1170 { 1171 uint64_t refs; 1172 /* Get while the hold prevents the dnode from moving. */ 1173 dmu_buf_impl_t *db = dn->dn_dbuf; 1174 dnode_handle_t *dnh = dn->dn_handle; 1175 1176 mutex_enter(&dn->dn_mtx); 1177 refs = refcount_remove(&dn->dn_holds, tag); 1178 mutex_exit(&dn->dn_mtx); 1179 1180 /* 1181 * It's unsafe to release the last hold on a dnode by dnode_rele() or 1182 * indirectly by dbuf_rele() while relying on the dnode handle to 1183 * prevent the dnode from moving, since releasing the last hold could 1184 * result in the dnode's parent dbuf evicting its dnode handles. For 1185 * that reason anyone calling dnode_rele() or dbuf_rele() without some 1186 * other direct or indirect hold on the dnode must first drop the dnode 1187 * handle. 1188 */ 1189 ASSERT(refs > 0 || dnh->dnh_zrlock.zr_owner != curthread); 1190 1191 /* NOTE: the DNODE_DNODE does not have a dn_dbuf */ 1192 if (refs == 0 && db != NULL) { 1193 /* 1194 * Another thread could add a hold to the dnode handle in 1195 * dnode_hold_impl() while holding the parent dbuf. Since the 1196 * hold on the parent dbuf prevents the handle from being 1197 * destroyed, the hold on the handle is OK. We can't yet assert 1198 * that the handle has zero references, but that will be 1199 * asserted anyway when the handle gets destroyed. 1200 */ 1201 dbuf_rele(db, dnh); 1202 } 1203 } 1204 1205 void 1206 dnode_setdirty(dnode_t *dn, dmu_tx_t *tx) 1207 { 1208 objset_t *os = dn->dn_objset; 1209 uint64_t txg = tx->tx_txg; 1210 1211 if (DMU_OBJECT_IS_SPECIAL(dn->dn_object)) { 1212 dsl_dataset_dirty(os->os_dsl_dataset, tx); 1213 return; 1214 } 1215 1216 DNODE_VERIFY(dn); 1217 1218 #ifdef ZFS_DEBUG 1219 mutex_enter(&dn->dn_mtx); 1220 ASSERT(dn->dn_phys->dn_type || dn->dn_allocated_txg); 1221 ASSERT(dn->dn_free_txg == 0 || dn->dn_free_txg >= txg); 1222 mutex_exit(&dn->dn_mtx); 1223 #endif 1224 1225 /* 1226 * Determine old uid/gid when necessary 1227 */ 1228 dmu_objset_userquota_get_ids(dn, B_TRUE, tx); 1229 1230 mutex_enter(&os->os_lock); 1231 1232 /* 1233 * If we are already marked dirty, we're done. 1234 */ 1235 if (list_link_active(&dn->dn_dirty_link[txg & TXG_MASK])) { 1236 mutex_exit(&os->os_lock); 1237 return; 1238 } 1239 1240 ASSERT(!refcount_is_zero(&dn->dn_holds) || list_head(&dn->dn_dbufs)); 1241 ASSERT(dn->dn_datablksz != 0); 1242 ASSERT0(dn->dn_next_bonuslen[txg&TXG_MASK]); 1243 ASSERT0(dn->dn_next_blksz[txg&TXG_MASK]); 1244 ASSERT0(dn->dn_next_bonustype[txg&TXG_MASK]); 1245 1246 dprintf_ds(os->os_dsl_dataset, "obj=%llu txg=%llu\n", 1247 dn->dn_object, txg); 1248 1249 if (dn->dn_free_txg > 0 && dn->dn_free_txg <= txg) { 1250 list_insert_tail(&os->os_free_dnodes[txg&TXG_MASK], dn); 1251 } else { 1252 list_insert_tail(&os->os_dirty_dnodes[txg&TXG_MASK], dn); 1253 } 1254 1255 mutex_exit(&os->os_lock); 1256 1257 /* 1258 * The dnode maintains a hold on its containing dbuf as 1259 * long as there are holds on it. Each instantiated child 1260 * dbuf maintains a hold on the dnode. When the last child 1261 * drops its hold, the dnode will drop its hold on the 1262 * containing dbuf. We add a "dirty hold" here so that the 1263 * dnode will hang around after we finish processing its 1264 * children. 1265 */ 1266 VERIFY(dnode_add_ref(dn, (void *)(uintptr_t)tx->tx_txg)); 1267 1268 (void) dbuf_dirty(dn->dn_dbuf, tx); 1269 1270 dsl_dataset_dirty(os->os_dsl_dataset, tx); 1271 } 1272 1273 void 1274 dnode_free(dnode_t *dn, dmu_tx_t *tx) 1275 { 1276 int txgoff = tx->tx_txg & TXG_MASK; 1277 1278 dprintf("dn=%p txg=%llu\n", dn, tx->tx_txg); 1279 1280 /* we should be the only holder... hopefully */ 1281 /* ASSERT3U(refcount_count(&dn->dn_holds), ==, 1); */ 1282 1283 mutex_enter(&dn->dn_mtx); 1284 if (dn->dn_type == DMU_OT_NONE || dn->dn_free_txg) { 1285 mutex_exit(&dn->dn_mtx); 1286 return; 1287 } 1288 dn->dn_free_txg = tx->tx_txg; 1289 mutex_exit(&dn->dn_mtx); 1290 1291 /* 1292 * If the dnode is already dirty, it needs to be moved from 1293 * the dirty list to the free list. 1294 */ 1295 mutex_enter(&dn->dn_objset->os_lock); 1296 if (list_link_active(&dn->dn_dirty_link[txgoff])) { 1297 list_remove(&dn->dn_objset->os_dirty_dnodes[txgoff], dn); 1298 list_insert_tail(&dn->dn_objset->os_free_dnodes[txgoff], dn); 1299 mutex_exit(&dn->dn_objset->os_lock); 1300 } else { 1301 mutex_exit(&dn->dn_objset->os_lock); 1302 dnode_setdirty(dn, tx); 1303 } 1304 } 1305 1306 /* 1307 * Try to change the block size for the indicated dnode. This can only 1308 * succeed if there are no blocks allocated or dirty beyond first block 1309 */ 1310 int 1311 dnode_set_blksz(dnode_t *dn, uint64_t size, int ibs, dmu_tx_t *tx) 1312 { 1313 dmu_buf_impl_t *db, *db_next; 1314 int err; 1315 1316 if (size == 0) 1317 size = SPA_MINBLOCKSIZE; 1318 if (size > SPA_MAXBLOCKSIZE) 1319 size = SPA_MAXBLOCKSIZE; 1320 else 1321 size = P2ROUNDUP(size, SPA_MINBLOCKSIZE); 1322 1323 if (ibs == dn->dn_indblkshift) 1324 ibs = 0; 1325 1326 if (size >> SPA_MINBLOCKSHIFT == dn->dn_datablkszsec && ibs == 0) 1327 return (0); 1328 1329 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 1330 1331 /* Check for any allocated blocks beyond the first */ 1332 if (dn->dn_phys->dn_maxblkid != 0) 1333 goto fail; 1334 1335 mutex_enter(&dn->dn_dbufs_mtx); 1336 for (db = list_head(&dn->dn_dbufs); db; db = db_next) { 1337 db_next = list_next(&dn->dn_dbufs, db); 1338 1339 if (db->db_blkid != 0 && db->db_blkid != DMU_BONUS_BLKID && 1340 db->db_blkid != DMU_SPILL_BLKID) { 1341 mutex_exit(&dn->dn_dbufs_mtx); 1342 goto fail; 1343 } 1344 } 1345 mutex_exit(&dn->dn_dbufs_mtx); 1346 1347 if (ibs && dn->dn_nlevels != 1) 1348 goto fail; 1349 1350 /* resize the old block */ 1351 err = dbuf_hold_impl(dn, 0, 0, TRUE, FTAG, &db); 1352 if (err == 0) 1353 dbuf_new_size(db, size, tx); 1354 else if (err != ENOENT) 1355 goto fail; 1356 1357 dnode_setdblksz(dn, size); 1358 dnode_setdirty(dn, tx); 1359 dn->dn_next_blksz[tx->tx_txg&TXG_MASK] = size; 1360 if (ibs) { 1361 dn->dn_indblkshift = ibs; 1362 dn->dn_next_indblkshift[tx->tx_txg&TXG_MASK] = ibs; 1363 } 1364 /* rele after we have fixed the blocksize in the dnode */ 1365 if (db) 1366 dbuf_rele(db, FTAG); 1367 1368 rw_exit(&dn->dn_struct_rwlock); 1369 return (0); 1370 1371 fail: 1372 rw_exit(&dn->dn_struct_rwlock); 1373 return (SET_ERROR(ENOTSUP)); 1374 } 1375 1376 /* read-holding callers must not rely on the lock being continuously held */ 1377 void 1378 dnode_new_blkid(dnode_t *dn, uint64_t blkid, dmu_tx_t *tx, boolean_t have_read) 1379 { 1380 uint64_t txgoff = tx->tx_txg & TXG_MASK; 1381 int epbs, new_nlevels; 1382 uint64_t sz; 1383 1384 ASSERT(blkid != DMU_BONUS_BLKID); 1385 1386 ASSERT(have_read ? 1387 RW_READ_HELD(&dn->dn_struct_rwlock) : 1388 RW_WRITE_HELD(&dn->dn_struct_rwlock)); 1389 1390 /* 1391 * if we have a read-lock, check to see if we need to do any work 1392 * before upgrading to a write-lock. 1393 */ 1394 if (have_read) { 1395 if (blkid <= dn->dn_maxblkid) 1396 return; 1397 1398 if (!rw_tryupgrade(&dn->dn_struct_rwlock)) { 1399 rw_exit(&dn->dn_struct_rwlock); 1400 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 1401 } 1402 } 1403 1404 if (blkid <= dn->dn_maxblkid) 1405 goto out; 1406 1407 dn->dn_maxblkid = blkid; 1408 1409 /* 1410 * Compute the number of levels necessary to support the new maxblkid. 1411 */ 1412 new_nlevels = 1; 1413 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT; 1414 for (sz = dn->dn_nblkptr; 1415 sz <= blkid && sz >= dn->dn_nblkptr; sz <<= epbs) 1416 new_nlevels++; 1417 1418 if (new_nlevels > dn->dn_nlevels) { 1419 int old_nlevels = dn->dn_nlevels; 1420 dmu_buf_impl_t *db; 1421 list_t *list; 1422 dbuf_dirty_record_t *new, *dr, *dr_next; 1423 1424 dn->dn_nlevels = new_nlevels; 1425 1426 ASSERT3U(new_nlevels, >, dn->dn_next_nlevels[txgoff]); 1427 dn->dn_next_nlevels[txgoff] = new_nlevels; 1428 1429 /* dirty the left indirects */ 1430 db = dbuf_hold_level(dn, old_nlevels, 0, FTAG); 1431 ASSERT(db != NULL); 1432 new = dbuf_dirty(db, tx); 1433 dbuf_rele(db, FTAG); 1434 1435 /* transfer the dirty records to the new indirect */ 1436 mutex_enter(&dn->dn_mtx); 1437 mutex_enter(&new->dt.di.dr_mtx); 1438 list = &dn->dn_dirty_records[txgoff]; 1439 for (dr = list_head(list); dr; dr = dr_next) { 1440 dr_next = list_next(&dn->dn_dirty_records[txgoff], dr); 1441 if (dr->dr_dbuf->db_level != new_nlevels-1 && 1442 dr->dr_dbuf->db_blkid != DMU_BONUS_BLKID && 1443 dr->dr_dbuf->db_blkid != DMU_SPILL_BLKID) { 1444 ASSERT(dr->dr_dbuf->db_level == old_nlevels-1); 1445 list_remove(&dn->dn_dirty_records[txgoff], dr); 1446 list_insert_tail(&new->dt.di.dr_children, dr); 1447 dr->dr_parent = new; 1448 } 1449 } 1450 mutex_exit(&new->dt.di.dr_mtx); 1451 mutex_exit(&dn->dn_mtx); 1452 } 1453 1454 out: 1455 if (have_read) 1456 rw_downgrade(&dn->dn_struct_rwlock); 1457 } 1458 1459 void 1460 dnode_clear_range(dnode_t *dn, uint64_t blkid, uint64_t nblks, dmu_tx_t *tx) 1461 { 1462 avl_tree_t *tree = &dn->dn_ranges[tx->tx_txg&TXG_MASK]; 1463 avl_index_t where; 1464 free_range_t *rp; 1465 free_range_t rp_tofind; 1466 uint64_t endblk = blkid + nblks; 1467 1468 ASSERT(MUTEX_HELD(&dn->dn_mtx)); 1469 ASSERT(nblks <= UINT64_MAX - blkid); /* no overflow */ 1470 1471 dprintf_dnode(dn, "blkid=%llu nblks=%llu txg=%llu\n", 1472 blkid, nblks, tx->tx_txg); 1473 rp_tofind.fr_blkid = blkid; 1474 rp = avl_find(tree, &rp_tofind, &where); 1475 if (rp == NULL) 1476 rp = avl_nearest(tree, where, AVL_BEFORE); 1477 if (rp == NULL) 1478 rp = avl_nearest(tree, where, AVL_AFTER); 1479 1480 while (rp && (rp->fr_blkid <= blkid + nblks)) { 1481 uint64_t fr_endblk = rp->fr_blkid + rp->fr_nblks; 1482 free_range_t *nrp = AVL_NEXT(tree, rp); 1483 1484 if (blkid <= rp->fr_blkid && endblk >= fr_endblk) { 1485 /* clear this entire range */ 1486 avl_remove(tree, rp); 1487 kmem_free(rp, sizeof (free_range_t)); 1488 } else if (blkid <= rp->fr_blkid && 1489 endblk > rp->fr_blkid && endblk < fr_endblk) { 1490 /* clear the beginning of this range */ 1491 rp->fr_blkid = endblk; 1492 rp->fr_nblks = fr_endblk - endblk; 1493 } else if (blkid > rp->fr_blkid && blkid < fr_endblk && 1494 endblk >= fr_endblk) { 1495 /* clear the end of this range */ 1496 rp->fr_nblks = blkid - rp->fr_blkid; 1497 } else if (blkid > rp->fr_blkid && endblk < fr_endblk) { 1498 /* clear a chunk out of this range */ 1499 free_range_t *new_rp = 1500 kmem_alloc(sizeof (free_range_t), KM_SLEEP); 1501 1502 new_rp->fr_blkid = endblk; 1503 new_rp->fr_nblks = fr_endblk - endblk; 1504 avl_insert_here(tree, new_rp, rp, AVL_AFTER); 1505 rp->fr_nblks = blkid - rp->fr_blkid; 1506 } 1507 /* there may be no overlap */ 1508 rp = nrp; 1509 } 1510 } 1511 1512 void 1513 dnode_free_range(dnode_t *dn, uint64_t off, uint64_t len, dmu_tx_t *tx) 1514 { 1515 dmu_buf_impl_t *db; 1516 uint64_t blkoff, blkid, nblks; 1517 int blksz, blkshift, head, tail; 1518 int trunc = FALSE; 1519 int epbs; 1520 1521 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 1522 blksz = dn->dn_datablksz; 1523 blkshift = dn->dn_datablkshift; 1524 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT; 1525 1526 if (len == -1ULL) { 1527 len = UINT64_MAX - off; 1528 trunc = TRUE; 1529 } 1530 1531 /* 1532 * First, block align the region to free: 1533 */ 1534 if (ISP2(blksz)) { 1535 head = P2NPHASE(off, blksz); 1536 blkoff = P2PHASE(off, blksz); 1537 if ((off >> blkshift) > dn->dn_maxblkid) 1538 goto out; 1539 } else { 1540 ASSERT(dn->dn_maxblkid == 0); 1541 if (off == 0 && len >= blksz) { 1542 /* Freeing the whole block; fast-track this request */ 1543 blkid = 0; 1544 nblks = 1; 1545 goto done; 1546 } else if (off >= blksz) { 1547 /* Freeing past end-of-data */ 1548 goto out; 1549 } else { 1550 /* Freeing part of the block. */ 1551 head = blksz - off; 1552 ASSERT3U(head, >, 0); 1553 } 1554 blkoff = off; 1555 } 1556 /* zero out any partial block data at the start of the range */ 1557 if (head) { 1558 ASSERT3U(blkoff + head, ==, blksz); 1559 if (len < head) 1560 head = len; 1561 if (dbuf_hold_impl(dn, 0, dbuf_whichblock(dn, off), TRUE, 1562 FTAG, &db) == 0) { 1563 caddr_t data; 1564 1565 /* don't dirty if it isn't on disk and isn't dirty */ 1566 if (db->db_last_dirty || 1567 (db->db_blkptr && !BP_IS_HOLE(db->db_blkptr))) { 1568 rw_exit(&dn->dn_struct_rwlock); 1569 dbuf_will_dirty(db, tx); 1570 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 1571 data = db->db.db_data; 1572 bzero(data + blkoff, head); 1573 } 1574 dbuf_rele(db, FTAG); 1575 } 1576 off += head; 1577 len -= head; 1578 } 1579 1580 /* If the range was less than one block, we're done */ 1581 if (len == 0) 1582 goto out; 1583 1584 /* If the remaining range is past end of file, we're done */ 1585 if ((off >> blkshift) > dn->dn_maxblkid) 1586 goto out; 1587 1588 ASSERT(ISP2(blksz)); 1589 if (trunc) 1590 tail = 0; 1591 else 1592 tail = P2PHASE(len, blksz); 1593 1594 ASSERT0(P2PHASE(off, blksz)); 1595 /* zero out any partial block data at the end of the range */ 1596 if (tail) { 1597 if (len < tail) 1598 tail = len; 1599 if (dbuf_hold_impl(dn, 0, dbuf_whichblock(dn, off+len), 1600 TRUE, FTAG, &db) == 0) { 1601 /* don't dirty if not on disk and not dirty */ 1602 if (db->db_last_dirty || 1603 (db->db_blkptr && !BP_IS_HOLE(db->db_blkptr))) { 1604 rw_exit(&dn->dn_struct_rwlock); 1605 dbuf_will_dirty(db, tx); 1606 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 1607 bzero(db->db.db_data, tail); 1608 } 1609 dbuf_rele(db, FTAG); 1610 } 1611 len -= tail; 1612 } 1613 1614 /* If the range did not include a full block, we are done */ 1615 if (len == 0) 1616 goto out; 1617 1618 ASSERT(IS_P2ALIGNED(off, blksz)); 1619 ASSERT(trunc || IS_P2ALIGNED(len, blksz)); 1620 blkid = off >> blkshift; 1621 nblks = len >> blkshift; 1622 if (trunc) 1623 nblks += 1; 1624 1625 /* 1626 * Read in and mark all the level-1 indirects dirty, 1627 * so that they will stay in memory until syncing phase. 1628 * Always dirty the first and last indirect to make sure 1629 * we dirty all the partial indirects. 1630 */ 1631 if (dn->dn_nlevels > 1) { 1632 uint64_t i, first, last; 1633 int shift = epbs + dn->dn_datablkshift; 1634 1635 first = blkid >> epbs; 1636 if (db = dbuf_hold_level(dn, 1, first, FTAG)) { 1637 dbuf_will_dirty(db, tx); 1638 dbuf_rele(db, FTAG); 1639 } 1640 if (trunc) 1641 last = dn->dn_maxblkid >> epbs; 1642 else 1643 last = (blkid + nblks - 1) >> epbs; 1644 if (last > first && (db = dbuf_hold_level(dn, 1, last, FTAG))) { 1645 dbuf_will_dirty(db, tx); 1646 dbuf_rele(db, FTAG); 1647 } 1648 for (i = first + 1; i < last; i++) { 1649 uint64_t ibyte = i << shift; 1650 int err; 1651 1652 err = dnode_next_offset(dn, 1653 DNODE_FIND_HAVELOCK, &ibyte, 1, 1, 0); 1654 i = ibyte >> shift; 1655 if (err == ESRCH || i >= last) 1656 break; 1657 ASSERT(err == 0); 1658 db = dbuf_hold_level(dn, 1, i, FTAG); 1659 if (db) { 1660 dbuf_will_dirty(db, tx); 1661 dbuf_rele(db, FTAG); 1662 } 1663 } 1664 } 1665 done: 1666 /* 1667 * Add this range to the dnode range list. 1668 * We will finish up this free operation in the syncing phase. 1669 */ 1670 mutex_enter(&dn->dn_mtx); 1671 dnode_clear_range(dn, blkid, nblks, tx); 1672 { 1673 free_range_t *rp, *found; 1674 avl_index_t where; 1675 avl_tree_t *tree = &dn->dn_ranges[tx->tx_txg&TXG_MASK]; 1676 1677 /* Add new range to dn_ranges */ 1678 rp = kmem_alloc(sizeof (free_range_t), KM_SLEEP); 1679 rp->fr_blkid = blkid; 1680 rp->fr_nblks = nblks; 1681 found = avl_find(tree, rp, &where); 1682 ASSERT(found == NULL); 1683 avl_insert(tree, rp, where); 1684 dprintf_dnode(dn, "blkid=%llu nblks=%llu txg=%llu\n", 1685 blkid, nblks, tx->tx_txg); 1686 } 1687 mutex_exit(&dn->dn_mtx); 1688 1689 dbuf_free_range(dn, blkid, blkid + nblks - 1, tx); 1690 dnode_setdirty(dn, tx); 1691 out: 1692 if (trunc && dn->dn_maxblkid >= (off >> blkshift)) 1693 dn->dn_maxblkid = (off >> blkshift ? (off >> blkshift) - 1 : 0); 1694 1695 rw_exit(&dn->dn_struct_rwlock); 1696 } 1697 1698 static boolean_t 1699 dnode_spill_freed(dnode_t *dn) 1700 { 1701 int i; 1702 1703 mutex_enter(&dn->dn_mtx); 1704 for (i = 0; i < TXG_SIZE; i++) { 1705 if (dn->dn_rm_spillblk[i] == DN_KILL_SPILLBLK) 1706 break; 1707 } 1708 mutex_exit(&dn->dn_mtx); 1709 return (i < TXG_SIZE); 1710 } 1711 1712 /* return TRUE if this blkid was freed in a recent txg, or FALSE if it wasn't */ 1713 uint64_t 1714 dnode_block_freed(dnode_t *dn, uint64_t blkid) 1715 { 1716 free_range_t range_tofind; 1717 void *dp = spa_get_dsl(dn->dn_objset->os_spa); 1718 int i; 1719 1720 if (blkid == DMU_BONUS_BLKID) 1721 return (FALSE); 1722 1723 /* 1724 * If we're in the process of opening the pool, dp will not be 1725 * set yet, but there shouldn't be anything dirty. 1726 */ 1727 if (dp == NULL) 1728 return (FALSE); 1729 1730 if (dn->dn_free_txg) 1731 return (TRUE); 1732 1733 if (blkid == DMU_SPILL_BLKID) 1734 return (dnode_spill_freed(dn)); 1735 1736 range_tofind.fr_blkid = blkid; 1737 mutex_enter(&dn->dn_mtx); 1738 for (i = 0; i < TXG_SIZE; i++) { 1739 free_range_t *range_found; 1740 avl_index_t idx; 1741 1742 range_found = avl_find(&dn->dn_ranges[i], &range_tofind, &idx); 1743 if (range_found) { 1744 ASSERT(range_found->fr_nblks > 0); 1745 break; 1746 } 1747 range_found = avl_nearest(&dn->dn_ranges[i], idx, AVL_BEFORE); 1748 if (range_found && 1749 range_found->fr_blkid + range_found->fr_nblks > blkid) 1750 break; 1751 } 1752 mutex_exit(&dn->dn_mtx); 1753 return (i < TXG_SIZE); 1754 } 1755 1756 /* call from syncing context when we actually write/free space for this dnode */ 1757 void 1758 dnode_diduse_space(dnode_t *dn, int64_t delta) 1759 { 1760 uint64_t space; 1761 dprintf_dnode(dn, "dn=%p dnp=%p used=%llu delta=%lld\n", 1762 dn, dn->dn_phys, 1763 (u_longlong_t)dn->dn_phys->dn_used, 1764 (longlong_t)delta); 1765 1766 mutex_enter(&dn->dn_mtx); 1767 space = DN_USED_BYTES(dn->dn_phys); 1768 if (delta > 0) { 1769 ASSERT3U(space + delta, >=, space); /* no overflow */ 1770 } else { 1771 ASSERT3U(space, >=, -delta); /* no underflow */ 1772 } 1773 space += delta; 1774 if (spa_version(dn->dn_objset->os_spa) < SPA_VERSION_DNODE_BYTES) { 1775 ASSERT((dn->dn_phys->dn_flags & DNODE_FLAG_USED_BYTES) == 0); 1776 ASSERT0(P2PHASE(space, 1<<DEV_BSHIFT)); 1777 dn->dn_phys->dn_used = space >> DEV_BSHIFT; 1778 } else { 1779 dn->dn_phys->dn_used = space; 1780 dn->dn_phys->dn_flags |= DNODE_FLAG_USED_BYTES; 1781 } 1782 mutex_exit(&dn->dn_mtx); 1783 } 1784 1785 /* 1786 * Call when we think we're going to write/free space in open context. 1787 * Be conservative (ie. OK to write less than this or free more than 1788 * this, but don't write more or free less). 1789 */ 1790 void 1791 dnode_willuse_space(dnode_t *dn, int64_t space, dmu_tx_t *tx) 1792 { 1793 objset_t *os = dn->dn_objset; 1794 dsl_dataset_t *ds = os->os_dsl_dataset; 1795 1796 if (space > 0) 1797 space = spa_get_asize(os->os_spa, space); 1798 1799 if (ds) 1800 dsl_dir_willuse_space(ds->ds_dir, space, tx); 1801 1802 dmu_tx_willuse_space(tx, space); 1803 } 1804 1805 /* 1806 * Scans a block at the indicated "level" looking for a hole or data, 1807 * depending on 'flags'. 1808 * 1809 * If level > 0, then we are scanning an indirect block looking at its 1810 * pointers. If level == 0, then we are looking at a block of dnodes. 1811 * 1812 * If we don't find what we are looking for in the block, we return ESRCH. 1813 * Otherwise, return with *offset pointing to the beginning (if searching 1814 * forwards) or end (if searching backwards) of the range covered by the 1815 * block pointer we matched on (or dnode). 1816 * 1817 * The basic search algorithm used below by dnode_next_offset() is to 1818 * use this function to search up the block tree (widen the search) until 1819 * we find something (i.e., we don't return ESRCH) and then search back 1820 * down the tree (narrow the search) until we reach our original search 1821 * level. 1822 */ 1823 static int 1824 dnode_next_offset_level(dnode_t *dn, int flags, uint64_t *offset, 1825 int lvl, uint64_t blkfill, uint64_t txg) 1826 { 1827 dmu_buf_impl_t *db = NULL; 1828 void *data = NULL; 1829 uint64_t epbs = dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT; 1830 uint64_t epb = 1ULL << epbs; 1831 uint64_t minfill, maxfill; 1832 boolean_t hole; 1833 int i, inc, error, span; 1834 1835 dprintf("probing object %llu offset %llx level %d of %u\n", 1836 dn->dn_object, *offset, lvl, dn->dn_phys->dn_nlevels); 1837 1838 hole = ((flags & DNODE_FIND_HOLE) != 0); 1839 inc = (flags & DNODE_FIND_BACKWARDS) ? -1 : 1; 1840 ASSERT(txg == 0 || !hole); 1841 1842 if (lvl == dn->dn_phys->dn_nlevels) { 1843 error = 0; 1844 epb = dn->dn_phys->dn_nblkptr; 1845 data = dn->dn_phys->dn_blkptr; 1846 } else { 1847 uint64_t blkid = dbuf_whichblock(dn, *offset) >> (epbs * lvl); 1848 error = dbuf_hold_impl(dn, lvl, blkid, TRUE, FTAG, &db); 1849 if (error) { 1850 if (error != ENOENT) 1851 return (error); 1852 if (hole) 1853 return (0); 1854 /* 1855 * This can only happen when we are searching up 1856 * the block tree for data. We don't really need to 1857 * adjust the offset, as we will just end up looking 1858 * at the pointer to this block in its parent, and its 1859 * going to be unallocated, so we will skip over it. 1860 */ 1861 return (SET_ERROR(ESRCH)); 1862 } 1863 error = dbuf_read(db, NULL, DB_RF_CANFAIL | DB_RF_HAVESTRUCT); 1864 if (error) { 1865 dbuf_rele(db, FTAG); 1866 return (error); 1867 } 1868 data = db->db.db_data; 1869 } 1870 1871 if (db && txg && 1872 (db->db_blkptr == NULL || db->db_blkptr->blk_birth <= txg)) { 1873 /* 1874 * This can only happen when we are searching up the tree 1875 * and these conditions mean that we need to keep climbing. 1876 */ 1877 error = SET_ERROR(ESRCH); 1878 } else if (lvl == 0) { 1879 dnode_phys_t *dnp = data; 1880 span = DNODE_SHIFT; 1881 ASSERT(dn->dn_type == DMU_OT_DNODE); 1882 1883 for (i = (*offset >> span) & (blkfill - 1); 1884 i >= 0 && i < blkfill; i += inc) { 1885 if ((dnp[i].dn_type == DMU_OT_NONE) == hole) 1886 break; 1887 *offset += (1ULL << span) * inc; 1888 } 1889 if (i < 0 || i == blkfill) 1890 error = SET_ERROR(ESRCH); 1891 } else { 1892 blkptr_t *bp = data; 1893 uint64_t start = *offset; 1894 span = (lvl - 1) * epbs + dn->dn_datablkshift; 1895 minfill = 0; 1896 maxfill = blkfill << ((lvl - 1) * epbs); 1897 1898 if (hole) 1899 maxfill--; 1900 else 1901 minfill++; 1902 1903 *offset = *offset >> span; 1904 for (i = BF64_GET(*offset, 0, epbs); 1905 i >= 0 && i < epb; i += inc) { 1906 if (bp[i].blk_fill >= minfill && 1907 bp[i].blk_fill <= maxfill && 1908 (hole || bp[i].blk_birth > txg)) 1909 break; 1910 if (inc > 0 || *offset > 0) 1911 *offset += inc; 1912 } 1913 *offset = *offset << span; 1914 if (inc < 0) { 1915 /* traversing backwards; position offset at the end */ 1916 ASSERT3U(*offset, <=, start); 1917 *offset = MIN(*offset + (1ULL << span) - 1, start); 1918 } else if (*offset < start) { 1919 *offset = start; 1920 } 1921 if (i < 0 || i >= epb) 1922 error = SET_ERROR(ESRCH); 1923 } 1924 1925 if (db) 1926 dbuf_rele(db, FTAG); 1927 1928 return (error); 1929 } 1930 1931 /* 1932 * Find the next hole, data, or sparse region at or after *offset. 1933 * The value 'blkfill' tells us how many items we expect to find 1934 * in an L0 data block; this value is 1 for normal objects, 1935 * DNODES_PER_BLOCK for the meta dnode, and some fraction of 1936 * DNODES_PER_BLOCK when searching for sparse regions thereof. 1937 * 1938 * Examples: 1939 * 1940 * dnode_next_offset(dn, flags, offset, 1, 1, 0); 1941 * Finds the next/previous hole/data in a file. 1942 * Used in dmu_offset_next(). 1943 * 1944 * dnode_next_offset(mdn, flags, offset, 0, DNODES_PER_BLOCK, txg); 1945 * Finds the next free/allocated dnode an objset's meta-dnode. 1946 * Only finds objects that have new contents since txg (ie. 1947 * bonus buffer changes and content removal are ignored). 1948 * Used in dmu_object_next(). 1949 * 1950 * dnode_next_offset(mdn, DNODE_FIND_HOLE, offset, 2, DNODES_PER_BLOCK >> 2, 0); 1951 * Finds the next L2 meta-dnode bp that's at most 1/4 full. 1952 * Used in dmu_object_alloc(). 1953 */ 1954 int 1955 dnode_next_offset(dnode_t *dn, int flags, uint64_t *offset, 1956 int minlvl, uint64_t blkfill, uint64_t txg) 1957 { 1958 uint64_t initial_offset = *offset; 1959 int lvl, maxlvl; 1960 int error = 0; 1961 1962 if (!(flags & DNODE_FIND_HAVELOCK)) 1963 rw_enter(&dn->dn_struct_rwlock, RW_READER); 1964 1965 if (dn->dn_phys->dn_nlevels == 0) { 1966 error = SET_ERROR(ESRCH); 1967 goto out; 1968 } 1969 1970 if (dn->dn_datablkshift == 0) { 1971 if (*offset < dn->dn_datablksz) { 1972 if (flags & DNODE_FIND_HOLE) 1973 *offset = dn->dn_datablksz; 1974 } else { 1975 error = SET_ERROR(ESRCH); 1976 } 1977 goto out; 1978 } 1979 1980 maxlvl = dn->dn_phys->dn_nlevels; 1981 1982 for (lvl = minlvl; lvl <= maxlvl; lvl++) { 1983 error = dnode_next_offset_level(dn, 1984 flags, offset, lvl, blkfill, txg); 1985 if (error != ESRCH) 1986 break; 1987 } 1988 1989 while (error == 0 && --lvl >= minlvl) { 1990 error = dnode_next_offset_level(dn, 1991 flags, offset, lvl, blkfill, txg); 1992 } 1993 1994 if (error == 0 && (flags & DNODE_FIND_BACKWARDS ? 1995 initial_offset < *offset : initial_offset > *offset)) 1996 error = SET_ERROR(ESRCH); 1997 out: 1998 if (!(flags & DNODE_FIND_HAVELOCK)) 1999 rw_exit(&dn->dn_struct_rwlock); 2000 2001 return (error); 2002 } 2003