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, 2019 by Delphix. All rights reserved. 24 * Copyright (c) 2014 Spectra Logic Corporation, All rights reserved. 25 * Copyright (c) 2014 Integros [integros.com] 26 * Copyright 2017 RackTop Systems. 27 */ 28 29 #include <sys/zfs_context.h> 30 #include <sys/dbuf.h> 31 #include <sys/dnode.h> 32 #include <sys/dmu.h> 33 #include <sys/dmu_impl.h> 34 #include <sys/dmu_tx.h> 35 #include <sys/dmu_objset.h> 36 #include <sys/dsl_dir.h> 37 #include <sys/dsl_dataset.h> 38 #include <sys/spa.h> 39 #include <sys/zio.h> 40 #include <sys/dmu_zfetch.h> 41 #include <sys/range_tree.h> 42 #include <sys/zfs_project.h> 43 44 dnode_stats_t dnode_stats = { 45 { "dnode_hold_dbuf_hold", KSTAT_DATA_UINT64 }, 46 { "dnode_hold_dbuf_read", KSTAT_DATA_UINT64 }, 47 { "dnode_hold_alloc_hits", KSTAT_DATA_UINT64 }, 48 { "dnode_hold_alloc_misses", KSTAT_DATA_UINT64 }, 49 { "dnode_hold_alloc_interior", KSTAT_DATA_UINT64 }, 50 { "dnode_hold_alloc_lock_retry", KSTAT_DATA_UINT64 }, 51 { "dnode_hold_alloc_lock_misses", KSTAT_DATA_UINT64 }, 52 { "dnode_hold_alloc_type_none", KSTAT_DATA_UINT64 }, 53 { "dnode_hold_free_hits", KSTAT_DATA_UINT64 }, 54 { "dnode_hold_free_misses", KSTAT_DATA_UINT64 }, 55 { "dnode_hold_free_lock_misses", KSTAT_DATA_UINT64 }, 56 { "dnode_hold_free_lock_retry", KSTAT_DATA_UINT64 }, 57 { "dnode_hold_free_overflow", KSTAT_DATA_UINT64 }, 58 { "dnode_hold_free_refcount", KSTAT_DATA_UINT64 }, 59 { "dnode_free_interior_lock_retry", KSTAT_DATA_UINT64 }, 60 { "dnode_allocate", KSTAT_DATA_UINT64 }, 61 { "dnode_reallocate", KSTAT_DATA_UINT64 }, 62 { "dnode_buf_evict", KSTAT_DATA_UINT64 }, 63 { "dnode_alloc_next_chunk", KSTAT_DATA_UINT64 }, 64 { "dnode_alloc_race", KSTAT_DATA_UINT64 }, 65 { "dnode_alloc_next_block", KSTAT_DATA_UINT64 }, 66 { "dnode_move_invalid", KSTAT_DATA_UINT64 }, 67 { "dnode_move_recheck1", KSTAT_DATA_UINT64 }, 68 { "dnode_move_recheck2", KSTAT_DATA_UINT64 }, 69 { "dnode_move_special", KSTAT_DATA_UINT64 }, 70 { "dnode_move_handle", KSTAT_DATA_UINT64 }, 71 { "dnode_move_rwlock", KSTAT_DATA_UINT64 }, 72 { "dnode_move_active", KSTAT_DATA_UINT64 }, 73 }; 74 75 static kstat_t *dnode_ksp; 76 static kmem_cache_t *dnode_cache; 77 78 static dnode_phys_t dnode_phys_zero; 79 80 int zfs_default_bs = SPA_MINBLOCKSHIFT; 81 int zfs_default_ibs = DN_MAX_INDBLKSHIFT; 82 83 #ifdef _KERNEL 84 static kmem_cbrc_t dnode_move(void *, void *, size_t, void *); 85 #endif /* _KERNEL */ 86 87 static int 88 dbuf_compare(const void *x1, const void *x2) 89 { 90 const dmu_buf_impl_t *d1 = x1; 91 const dmu_buf_impl_t *d2 = x2; 92 93 int cmp = TREE_CMP(d1->db_level, d2->db_level); 94 if (likely(cmp)) 95 return (cmp); 96 97 cmp = TREE_CMP(d1->db_blkid, d2->db_blkid); 98 if (likely(cmp)) 99 return (cmp); 100 101 if (d1->db_state == DB_SEARCH) { 102 ASSERT3S(d2->db_state, !=, DB_SEARCH); 103 return (-1); 104 } else if (d2->db_state == DB_SEARCH) { 105 ASSERT3S(d1->db_state, !=, DB_SEARCH); 106 return (1); 107 } 108 109 return (TREE_PCMP(d1, d2)); 110 } 111 112 /* ARGSUSED */ 113 static int 114 dnode_cons(void *arg, void *unused, int kmflag) 115 { 116 dnode_t *dn = arg; 117 int i; 118 119 rw_init(&dn->dn_struct_rwlock, NULL, RW_DEFAULT, NULL); 120 mutex_init(&dn->dn_mtx, NULL, MUTEX_DEFAULT, NULL); 121 mutex_init(&dn->dn_dbufs_mtx, NULL, MUTEX_DEFAULT, NULL); 122 cv_init(&dn->dn_notxholds, NULL, CV_DEFAULT, NULL); 123 cv_init(&dn->dn_nodnholds, NULL, CV_DEFAULT, NULL); 124 125 /* 126 * Every dbuf has a reference, and dropping a tracked reference is 127 * O(number of references), so don't track dn_holds. 128 */ 129 zfs_refcount_create_untracked(&dn->dn_holds); 130 zfs_refcount_create(&dn->dn_tx_holds); 131 list_link_init(&dn->dn_link); 132 133 bzero(&dn->dn_next_nblkptr[0], sizeof (dn->dn_next_nblkptr)); 134 bzero(&dn->dn_next_nlevels[0], sizeof (dn->dn_next_nlevels)); 135 bzero(&dn->dn_next_indblkshift[0], sizeof (dn->dn_next_indblkshift)); 136 bzero(&dn->dn_next_bonustype[0], sizeof (dn->dn_next_bonustype)); 137 bzero(&dn->dn_rm_spillblk[0], sizeof (dn->dn_rm_spillblk)); 138 bzero(&dn->dn_next_bonuslen[0], sizeof (dn->dn_next_bonuslen)); 139 bzero(&dn->dn_next_blksz[0], sizeof (dn->dn_next_blksz)); 140 bzero(&dn->dn_next_maxblkid[0], sizeof (dn->dn_next_maxblkid)); 141 142 for (i = 0; i < TXG_SIZE; i++) { 143 multilist_link_init(&dn->dn_dirty_link[i]); 144 dn->dn_free_ranges[i] = NULL; 145 list_create(&dn->dn_dirty_records[i], 146 sizeof (dbuf_dirty_record_t), 147 offsetof(dbuf_dirty_record_t, dr_dirty_node)); 148 } 149 150 dn->dn_allocated_txg = 0; 151 dn->dn_free_txg = 0; 152 dn->dn_assigned_txg = 0; 153 dn->dn_dirty_txg = 0; 154 dn->dn_dirtyctx = 0; 155 dn->dn_dirtyctx_firstset = NULL; 156 dn->dn_bonus = NULL; 157 dn->dn_have_spill = B_FALSE; 158 dn->dn_zio = NULL; 159 dn->dn_oldused = 0; 160 dn->dn_oldflags = 0; 161 dn->dn_olduid = 0; 162 dn->dn_oldgid = 0; 163 dn->dn_oldprojid = ZFS_DEFAULT_PROJID; 164 dn->dn_newuid = 0; 165 dn->dn_newgid = 0; 166 dn->dn_newprojid = ZFS_DEFAULT_PROJID; 167 dn->dn_id_flags = 0; 168 169 dn->dn_dbufs_count = 0; 170 avl_create(&dn->dn_dbufs, dbuf_compare, sizeof (dmu_buf_impl_t), 171 offsetof(dmu_buf_impl_t, db_link)); 172 173 dn->dn_moved = 0; 174 return (0); 175 } 176 177 /* ARGSUSED */ 178 static void 179 dnode_dest(void *arg, void *unused) 180 { 181 int i; 182 dnode_t *dn = arg; 183 184 rw_destroy(&dn->dn_struct_rwlock); 185 mutex_destroy(&dn->dn_mtx); 186 mutex_destroy(&dn->dn_dbufs_mtx); 187 cv_destroy(&dn->dn_notxholds); 188 cv_destroy(&dn->dn_nodnholds); 189 zfs_refcount_destroy(&dn->dn_holds); 190 zfs_refcount_destroy(&dn->dn_tx_holds); 191 ASSERT(!list_link_active(&dn->dn_link)); 192 193 for (i = 0; i < TXG_SIZE; i++) { 194 ASSERT(!multilist_link_active(&dn->dn_dirty_link[i])); 195 ASSERT3P(dn->dn_free_ranges[i], ==, NULL); 196 list_destroy(&dn->dn_dirty_records[i]); 197 ASSERT0(dn->dn_next_nblkptr[i]); 198 ASSERT0(dn->dn_next_nlevels[i]); 199 ASSERT0(dn->dn_next_indblkshift[i]); 200 ASSERT0(dn->dn_next_bonustype[i]); 201 ASSERT0(dn->dn_rm_spillblk[i]); 202 ASSERT0(dn->dn_next_bonuslen[i]); 203 ASSERT0(dn->dn_next_blksz[i]); 204 ASSERT0(dn->dn_next_maxblkid[i]); 205 } 206 207 ASSERT0(dn->dn_allocated_txg); 208 ASSERT0(dn->dn_free_txg); 209 ASSERT0(dn->dn_assigned_txg); 210 ASSERT0(dn->dn_dirty_txg); 211 ASSERT0(dn->dn_dirtyctx); 212 ASSERT3P(dn->dn_dirtyctx_firstset, ==, NULL); 213 ASSERT3P(dn->dn_bonus, ==, NULL); 214 ASSERT(!dn->dn_have_spill); 215 ASSERT3P(dn->dn_zio, ==, NULL); 216 ASSERT0(dn->dn_oldused); 217 ASSERT0(dn->dn_oldflags); 218 ASSERT0(dn->dn_olduid); 219 ASSERT0(dn->dn_oldgid); 220 ASSERT0(dn->dn_oldprojid); 221 ASSERT0(dn->dn_newuid); 222 ASSERT0(dn->dn_newgid); 223 ASSERT0(dn->dn_newprojid); 224 ASSERT0(dn->dn_id_flags); 225 226 ASSERT0(dn->dn_dbufs_count); 227 avl_destroy(&dn->dn_dbufs); 228 } 229 230 void 231 dnode_init(void) 232 { 233 ASSERT(dnode_cache == NULL); 234 dnode_cache = kmem_cache_create("dnode_t", 235 sizeof (dnode_t), 236 0, dnode_cons, dnode_dest, NULL, NULL, NULL, 0); 237 #ifdef _KERNEL 238 kmem_cache_set_move(dnode_cache, dnode_move); 239 240 dnode_ksp = kstat_create("zfs", 0, "dnodestats", "misc", 241 KSTAT_TYPE_NAMED, sizeof (dnode_stats) / sizeof (kstat_named_t), 242 KSTAT_FLAG_VIRTUAL); 243 if (dnode_ksp != NULL) { 244 dnode_ksp->ks_data = &dnode_stats; 245 kstat_install(dnode_ksp); 246 } 247 #endif /* _KERNEL */ 248 } 249 250 void 251 dnode_fini(void) 252 { 253 if (dnode_ksp != NULL) { 254 kstat_delete(dnode_ksp); 255 dnode_ksp = NULL; 256 } 257 258 kmem_cache_destroy(dnode_cache); 259 dnode_cache = NULL; 260 } 261 262 263 #ifdef ZFS_DEBUG 264 void 265 dnode_verify(dnode_t *dn) 266 { 267 int drop_struct_lock = FALSE; 268 269 ASSERT(dn->dn_phys); 270 ASSERT(dn->dn_objset); 271 ASSERT(dn->dn_handle->dnh_dnode == dn); 272 273 ASSERT(DMU_OT_IS_VALID(dn->dn_phys->dn_type)); 274 275 if (!(zfs_flags & ZFS_DEBUG_DNODE_VERIFY)) 276 return; 277 278 if (!RW_WRITE_HELD(&dn->dn_struct_rwlock)) { 279 rw_enter(&dn->dn_struct_rwlock, RW_READER); 280 drop_struct_lock = TRUE; 281 } 282 if (dn->dn_phys->dn_type != DMU_OT_NONE || dn->dn_allocated_txg != 0) { 283 int i; 284 int max_bonuslen = DN_SLOTS_TO_BONUSLEN(dn->dn_num_slots); 285 ASSERT3U(dn->dn_indblkshift, >=, 0); 286 ASSERT3U(dn->dn_indblkshift, <=, SPA_MAXBLOCKSHIFT); 287 if (dn->dn_datablkshift) { 288 ASSERT3U(dn->dn_datablkshift, >=, SPA_MINBLOCKSHIFT); 289 ASSERT3U(dn->dn_datablkshift, <=, SPA_MAXBLOCKSHIFT); 290 ASSERT3U(1<<dn->dn_datablkshift, ==, dn->dn_datablksz); 291 } 292 ASSERT3U(dn->dn_nlevels, <=, 30); 293 ASSERT(DMU_OT_IS_VALID(dn->dn_type)); 294 ASSERT3U(dn->dn_nblkptr, >=, 1); 295 ASSERT3U(dn->dn_nblkptr, <=, DN_MAX_NBLKPTR); 296 ASSERT3U(dn->dn_bonuslen, <=, max_bonuslen); 297 ASSERT3U(dn->dn_datablksz, ==, 298 dn->dn_datablkszsec << SPA_MINBLOCKSHIFT); 299 ASSERT3U(ISP2(dn->dn_datablksz), ==, dn->dn_datablkshift != 0); 300 ASSERT3U((dn->dn_nblkptr - 1) * sizeof (blkptr_t) + 301 dn->dn_bonuslen, <=, max_bonuslen); 302 for (i = 0; i < TXG_SIZE; i++) { 303 ASSERT3U(dn->dn_next_nlevels[i], <=, dn->dn_nlevels); 304 } 305 } 306 if (dn->dn_phys->dn_type != DMU_OT_NONE) 307 ASSERT3U(dn->dn_phys->dn_nlevels, <=, dn->dn_nlevels); 308 ASSERT(DMU_OBJECT_IS_SPECIAL(dn->dn_object) || dn->dn_dbuf != NULL); 309 if (dn->dn_dbuf != NULL) { 310 ASSERT3P(dn->dn_phys, ==, 311 (dnode_phys_t *)dn->dn_dbuf->db.db_data + 312 (dn->dn_object % (dn->dn_dbuf->db.db_size >> DNODE_SHIFT))); 313 } 314 if (drop_struct_lock) 315 rw_exit(&dn->dn_struct_rwlock); 316 } 317 #endif 318 319 void 320 dnode_byteswap(dnode_phys_t *dnp) 321 { 322 uint64_t *buf64 = (void*)&dnp->dn_blkptr; 323 int i; 324 325 if (dnp->dn_type == DMU_OT_NONE) { 326 bzero(dnp, sizeof (dnode_phys_t)); 327 return; 328 } 329 330 dnp->dn_datablkszsec = BSWAP_16(dnp->dn_datablkszsec); 331 dnp->dn_bonuslen = BSWAP_16(dnp->dn_bonuslen); 332 dnp->dn_extra_slots = BSWAP_8(dnp->dn_extra_slots); 333 dnp->dn_maxblkid = BSWAP_64(dnp->dn_maxblkid); 334 dnp->dn_used = BSWAP_64(dnp->dn_used); 335 336 /* 337 * dn_nblkptr is only one byte, so it's OK to read it in either 338 * byte order. We can't read dn_bouslen. 339 */ 340 ASSERT(dnp->dn_indblkshift <= SPA_MAXBLOCKSHIFT); 341 ASSERT(dnp->dn_nblkptr <= DN_MAX_NBLKPTR); 342 for (i = 0; i < dnp->dn_nblkptr * sizeof (blkptr_t)/8; i++) 343 buf64[i] = BSWAP_64(buf64[i]); 344 345 /* 346 * OK to check dn_bonuslen for zero, because it won't matter if 347 * we have the wrong byte order. This is necessary because the 348 * dnode dnode is smaller than a regular dnode. 349 */ 350 if (dnp->dn_bonuslen != 0) { 351 /* 352 * Note that the bonus length calculated here may be 353 * longer than the actual bonus buffer. This is because 354 * we always put the bonus buffer after the last block 355 * pointer (instead of packing it against the end of the 356 * dnode buffer). 357 */ 358 int off = (dnp->dn_nblkptr-1) * sizeof (blkptr_t); 359 int slots = dnp->dn_extra_slots + 1; 360 size_t len = DN_SLOTS_TO_BONUSLEN(slots) - off; 361 ASSERT(DMU_OT_IS_VALID(dnp->dn_bonustype)); 362 dmu_object_byteswap_t byteswap = 363 DMU_OT_BYTESWAP(dnp->dn_bonustype); 364 dmu_ot_byteswap[byteswap].ob_func(dnp->dn_bonus + off, len); 365 } 366 367 /* Swap SPILL block if we have one */ 368 if (dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) 369 byteswap_uint64_array(DN_SPILL_BLKPTR(dnp), sizeof (blkptr_t)); 370 371 } 372 373 void 374 dnode_buf_byteswap(void *vbuf, size_t size) 375 { 376 int i = 0; 377 378 ASSERT3U(sizeof (dnode_phys_t), ==, (1<<DNODE_SHIFT)); 379 ASSERT((size & (sizeof (dnode_phys_t)-1)) == 0); 380 381 while (i < size) { 382 dnode_phys_t *dnp = (void *)(((char *)vbuf) + i); 383 dnode_byteswap(dnp); 384 385 i += DNODE_MIN_SIZE; 386 if (dnp->dn_type != DMU_OT_NONE) 387 i += dnp->dn_extra_slots * DNODE_MIN_SIZE; 388 } 389 } 390 391 void 392 dnode_setbonuslen(dnode_t *dn, int newsize, dmu_tx_t *tx) 393 { 394 ASSERT3U(zfs_refcount_count(&dn->dn_holds), >=, 1); 395 396 dnode_setdirty(dn, tx); 397 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 398 ASSERT3U(newsize, <=, DN_SLOTS_TO_BONUSLEN(dn->dn_num_slots) - 399 (dn->dn_nblkptr-1) * sizeof (blkptr_t)); 400 dn->dn_bonuslen = newsize; 401 if (newsize == 0) 402 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = DN_ZERO_BONUSLEN; 403 else 404 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = dn->dn_bonuslen; 405 rw_exit(&dn->dn_struct_rwlock); 406 } 407 408 void 409 dnode_setbonus_type(dnode_t *dn, dmu_object_type_t newtype, dmu_tx_t *tx) 410 { 411 ASSERT3U(zfs_refcount_count(&dn->dn_holds), >=, 1); 412 dnode_setdirty(dn, tx); 413 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 414 dn->dn_bonustype = newtype; 415 dn->dn_next_bonustype[tx->tx_txg & TXG_MASK] = dn->dn_bonustype; 416 rw_exit(&dn->dn_struct_rwlock); 417 } 418 419 void 420 dnode_rm_spill(dnode_t *dn, dmu_tx_t *tx) 421 { 422 ASSERT3U(zfs_refcount_count(&dn->dn_holds), >=, 1); 423 ASSERT(RW_WRITE_HELD(&dn->dn_struct_rwlock)); 424 dnode_setdirty(dn, tx); 425 dn->dn_rm_spillblk[tx->tx_txg&TXG_MASK] = DN_KILL_SPILLBLK; 426 dn->dn_have_spill = B_FALSE; 427 } 428 429 static void 430 dnode_setdblksz(dnode_t *dn, int size) 431 { 432 ASSERT0(P2PHASE(size, SPA_MINBLOCKSIZE)); 433 ASSERT3U(size, <=, SPA_MAXBLOCKSIZE); 434 ASSERT3U(size, >=, SPA_MINBLOCKSIZE); 435 ASSERT3U(size >> SPA_MINBLOCKSHIFT, <, 436 1<<(sizeof (dn->dn_phys->dn_datablkszsec) * 8)); 437 dn->dn_datablksz = size; 438 dn->dn_datablkszsec = size >> SPA_MINBLOCKSHIFT; 439 dn->dn_datablkshift = ISP2(size) ? highbit64(size - 1) : 0; 440 } 441 442 static dnode_t * 443 dnode_create(objset_t *os, dnode_phys_t *dnp, dmu_buf_impl_t *db, 444 uint64_t object, dnode_handle_t *dnh) 445 { 446 dnode_t *dn; 447 448 dn = kmem_cache_alloc(dnode_cache, KM_SLEEP); 449 #ifdef _KERNEL 450 ASSERT(!POINTER_IS_VALID(dn->dn_objset)); 451 #endif /* _KERNEL */ 452 dn->dn_moved = 0; 453 454 /* 455 * Defer setting dn_objset until the dnode is ready to be a candidate 456 * for the dnode_move() callback. 457 */ 458 dn->dn_object = object; 459 dn->dn_dbuf = db; 460 dn->dn_handle = dnh; 461 dn->dn_phys = dnp; 462 463 if (dnp->dn_datablkszsec) { 464 dnode_setdblksz(dn, dnp->dn_datablkszsec << SPA_MINBLOCKSHIFT); 465 } else { 466 dn->dn_datablksz = 0; 467 dn->dn_datablkszsec = 0; 468 dn->dn_datablkshift = 0; 469 } 470 dn->dn_indblkshift = dnp->dn_indblkshift; 471 dn->dn_nlevels = dnp->dn_nlevels; 472 dn->dn_type = dnp->dn_type; 473 dn->dn_nblkptr = dnp->dn_nblkptr; 474 dn->dn_checksum = dnp->dn_checksum; 475 dn->dn_compress = dnp->dn_compress; 476 dn->dn_bonustype = dnp->dn_bonustype; 477 dn->dn_bonuslen = dnp->dn_bonuslen; 478 dn->dn_num_slots = dnp->dn_extra_slots + 1; 479 dn->dn_maxblkid = dnp->dn_maxblkid; 480 dn->dn_have_spill = ((dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) != 0); 481 dn->dn_id_flags = 0; 482 483 dmu_zfetch_init(&dn->dn_zfetch, dn); 484 485 ASSERT(DMU_OT_IS_VALID(dn->dn_phys->dn_type)); 486 ASSERT(zrl_is_locked(&dnh->dnh_zrlock)); 487 ASSERT(!DN_SLOT_IS_PTR(dnh->dnh_dnode)); 488 489 mutex_enter(&os->os_lock); 490 491 /* 492 * Exclude special dnodes from os_dnodes so an empty os_dnodes 493 * signifies that the special dnodes have no references from 494 * their children (the entries in os_dnodes). This allows 495 * dnode_destroy() to easily determine if the last child has 496 * been removed and then complete eviction of the objset. 497 */ 498 if (!DMU_OBJECT_IS_SPECIAL(object)) 499 list_insert_head(&os->os_dnodes, dn); 500 membar_producer(); 501 502 /* 503 * Everything else must be valid before assigning dn_objset 504 * makes the dnode eligible for dnode_move(). 505 */ 506 dn->dn_objset = os; 507 508 dnh->dnh_dnode = dn; 509 mutex_exit(&os->os_lock); 510 511 arc_space_consume(sizeof (dnode_t), ARC_SPACE_OTHER); 512 513 return (dn); 514 } 515 516 /* 517 * Caller must be holding the dnode handle, which is released upon return. 518 */ 519 static void 520 dnode_destroy(dnode_t *dn) 521 { 522 objset_t *os = dn->dn_objset; 523 boolean_t complete_os_eviction = B_FALSE; 524 525 ASSERT((dn->dn_id_flags & DN_ID_NEW_EXIST) == 0); 526 527 mutex_enter(&os->os_lock); 528 POINTER_INVALIDATE(&dn->dn_objset); 529 if (!DMU_OBJECT_IS_SPECIAL(dn->dn_object)) { 530 list_remove(&os->os_dnodes, dn); 531 complete_os_eviction = 532 list_is_empty(&os->os_dnodes) && 533 list_link_active(&os->os_evicting_node); 534 } 535 mutex_exit(&os->os_lock); 536 537 /* the dnode can no longer move, so we can release the handle */ 538 if (!zrl_is_locked(&dn->dn_handle->dnh_zrlock)) 539 zrl_remove(&dn->dn_handle->dnh_zrlock); 540 541 dn->dn_allocated_txg = 0; 542 dn->dn_free_txg = 0; 543 dn->dn_assigned_txg = 0; 544 dn->dn_dirty_txg = 0; 545 546 dn->dn_dirtyctx = 0; 547 if (dn->dn_dirtyctx_firstset != NULL) { 548 kmem_free(dn->dn_dirtyctx_firstset, 1); 549 dn->dn_dirtyctx_firstset = NULL; 550 } 551 if (dn->dn_bonus != NULL) { 552 mutex_enter(&dn->dn_bonus->db_mtx); 553 dbuf_destroy(dn->dn_bonus); 554 dn->dn_bonus = NULL; 555 } 556 dn->dn_zio = NULL; 557 558 dn->dn_have_spill = B_FALSE; 559 dn->dn_oldused = 0; 560 dn->dn_oldflags = 0; 561 dn->dn_olduid = 0; 562 dn->dn_oldgid = 0; 563 dn->dn_oldprojid = ZFS_DEFAULT_PROJID; 564 dn->dn_newuid = 0; 565 dn->dn_newgid = 0; 566 dn->dn_newprojid = ZFS_DEFAULT_PROJID; 567 dn->dn_id_flags = 0; 568 569 dmu_zfetch_fini(&dn->dn_zfetch); 570 kmem_cache_free(dnode_cache, dn); 571 arc_space_return(sizeof (dnode_t), ARC_SPACE_OTHER); 572 573 if (complete_os_eviction) 574 dmu_objset_evict_done(os); 575 } 576 577 void 578 dnode_allocate(dnode_t *dn, dmu_object_type_t ot, int blocksize, int ibs, 579 dmu_object_type_t bonustype, int bonuslen, int dn_slots, dmu_tx_t *tx) 580 { 581 int i; 582 583 ASSERT3U(dn_slots, >, 0); 584 ASSERT3U(dn_slots << DNODE_SHIFT, <=, 585 spa_maxdnodesize(dmu_objset_spa(dn->dn_objset))); 586 ASSERT3U(blocksize, <=, 587 spa_maxblocksize(dmu_objset_spa(dn->dn_objset))); 588 if (blocksize == 0) 589 blocksize = 1 << zfs_default_bs; 590 else 591 blocksize = P2ROUNDUP(blocksize, SPA_MINBLOCKSIZE); 592 593 if (ibs == 0) 594 ibs = zfs_default_ibs; 595 596 ibs = MIN(MAX(ibs, DN_MIN_INDBLKSHIFT), DN_MAX_INDBLKSHIFT); 597 598 dprintf("os=%p obj=%" PRIu64 " txg=%" PRIu64 599 " blocksize=%d ibs=%d dn_slots=%d\n", 600 dn->dn_objset, dn->dn_object, tx->tx_txg, blocksize, ibs, dn_slots); 601 DNODE_STAT_BUMP(dnode_allocate); 602 603 ASSERT(dn->dn_type == DMU_OT_NONE); 604 ASSERT(bcmp(dn->dn_phys, &dnode_phys_zero, sizeof (dnode_phys_t)) == 0); 605 ASSERT(dn->dn_phys->dn_type == DMU_OT_NONE); 606 ASSERT(ot != DMU_OT_NONE); 607 ASSERT(DMU_OT_IS_VALID(ot)); 608 ASSERT((bonustype == DMU_OT_NONE && bonuslen == 0) || 609 (bonustype == DMU_OT_SA && bonuslen == 0) || 610 (bonustype != DMU_OT_NONE && bonuslen != 0)); 611 ASSERT(DMU_OT_IS_VALID(bonustype)); 612 ASSERT3U(bonuslen, <=, DN_SLOTS_TO_BONUSLEN(dn_slots)); 613 ASSERT(dn->dn_type == DMU_OT_NONE); 614 ASSERT0(dn->dn_maxblkid); 615 ASSERT0(dn->dn_allocated_txg); 616 ASSERT0(dn->dn_dirty_txg); 617 ASSERT0(dn->dn_assigned_txg); 618 ASSERT(zfs_refcount_is_zero(&dn->dn_tx_holds)); 619 ASSERT3U(zfs_refcount_count(&dn->dn_holds), <=, 1); 620 ASSERT(avl_is_empty(&dn->dn_dbufs)); 621 622 for (i = 0; i < TXG_SIZE; i++) { 623 ASSERT0(dn->dn_next_nblkptr[i]); 624 ASSERT0(dn->dn_next_nlevels[i]); 625 ASSERT0(dn->dn_next_indblkshift[i]); 626 ASSERT0(dn->dn_next_bonuslen[i]); 627 ASSERT0(dn->dn_next_bonustype[i]); 628 ASSERT0(dn->dn_rm_spillblk[i]); 629 ASSERT0(dn->dn_next_blksz[i]); 630 ASSERT0(dn->dn_next_maxblkid[i]); 631 ASSERT(!multilist_link_active(&dn->dn_dirty_link[i])); 632 ASSERT3P(list_head(&dn->dn_dirty_records[i]), ==, NULL); 633 ASSERT3P(dn->dn_free_ranges[i], ==, NULL); 634 } 635 636 dn->dn_type = ot; 637 dnode_setdblksz(dn, blocksize); 638 dn->dn_indblkshift = ibs; 639 dn->dn_nlevels = 1; 640 dn->dn_num_slots = dn_slots; 641 if (bonustype == DMU_OT_SA) /* Maximize bonus space for SA */ 642 dn->dn_nblkptr = 1; 643 else { 644 dn->dn_nblkptr = MIN(DN_MAX_NBLKPTR, 645 1 + ((DN_SLOTS_TO_BONUSLEN(dn_slots) - bonuslen) >> 646 SPA_BLKPTRSHIFT)); 647 } 648 649 dn->dn_bonustype = bonustype; 650 dn->dn_bonuslen = bonuslen; 651 dn->dn_checksum = ZIO_CHECKSUM_INHERIT; 652 dn->dn_compress = ZIO_COMPRESS_INHERIT; 653 dn->dn_dirtyctx = 0; 654 655 dn->dn_free_txg = 0; 656 if (dn->dn_dirtyctx_firstset) { 657 kmem_free(dn->dn_dirtyctx_firstset, 1); 658 dn->dn_dirtyctx_firstset = NULL; 659 } 660 661 dn->dn_allocated_txg = tx->tx_txg; 662 dn->dn_id_flags = 0; 663 664 dnode_setdirty(dn, tx); 665 dn->dn_next_indblkshift[tx->tx_txg & TXG_MASK] = ibs; 666 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = dn->dn_bonuslen; 667 dn->dn_next_bonustype[tx->tx_txg & TXG_MASK] = dn->dn_bonustype; 668 dn->dn_next_blksz[tx->tx_txg & TXG_MASK] = dn->dn_datablksz; 669 } 670 671 void 672 dnode_reallocate(dnode_t *dn, dmu_object_type_t ot, int blocksize, 673 dmu_object_type_t bonustype, int bonuslen, int dn_slots, 674 boolean_t keep_spill, dmu_tx_t *tx) 675 { 676 int nblkptr; 677 678 ASSERT3U(blocksize, >=, SPA_MINBLOCKSIZE); 679 ASSERT3U(blocksize, <=, 680 spa_maxblocksize(dmu_objset_spa(dn->dn_objset))); 681 ASSERT0(blocksize % SPA_MINBLOCKSIZE); 682 ASSERT(dn->dn_object != DMU_META_DNODE_OBJECT || dmu_tx_private_ok(tx)); 683 ASSERT(tx->tx_txg != 0); 684 ASSERT((bonustype == DMU_OT_NONE && bonuslen == 0) || 685 (bonustype != DMU_OT_NONE && bonuslen != 0) || 686 (bonustype == DMU_OT_SA && bonuslen == 0)); 687 ASSERT(DMU_OT_IS_VALID(bonustype)); 688 ASSERT3U(bonuslen, <=, 689 DN_BONUS_SIZE(spa_maxdnodesize(dmu_objset_spa(dn->dn_objset)))); 690 ASSERT3U(bonuslen, <=, DN_BONUS_SIZE(dn_slots << DNODE_SHIFT)); 691 692 dnode_free_interior_slots(dn); 693 DNODE_STAT_BUMP(dnode_reallocate); 694 695 /* clean up any unreferenced dbufs */ 696 dnode_evict_dbufs(dn); 697 698 dn->dn_id_flags = 0; 699 700 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 701 dnode_setdirty(dn, tx); 702 if (dn->dn_datablksz != blocksize) { 703 /* change blocksize */ 704 ASSERT(dn->dn_maxblkid == 0 && 705 (BP_IS_HOLE(&dn->dn_phys->dn_blkptr[0]) || 706 dnode_block_freed(dn, 0))); 707 dnode_setdblksz(dn, blocksize); 708 dn->dn_next_blksz[tx->tx_txg&TXG_MASK] = blocksize; 709 } 710 if (dn->dn_bonuslen != bonuslen) 711 dn->dn_next_bonuslen[tx->tx_txg&TXG_MASK] = bonuslen; 712 713 if (bonustype == DMU_OT_SA) /* Maximize bonus space for SA */ 714 nblkptr = 1; 715 else 716 nblkptr = MIN(DN_MAX_NBLKPTR, 717 1 + ((DN_SLOTS_TO_BONUSLEN(dn_slots) - bonuslen) >> 718 SPA_BLKPTRSHIFT)); 719 if (dn->dn_bonustype != bonustype) 720 dn->dn_next_bonustype[tx->tx_txg&TXG_MASK] = bonustype; 721 if (dn->dn_nblkptr != nblkptr) 722 dn->dn_next_nblkptr[tx->tx_txg&TXG_MASK] = nblkptr; 723 if (dn->dn_phys->dn_flags & DNODE_FLAG_SPILL_BLKPTR && !keep_spill) { 724 dbuf_rm_spill(dn, tx); 725 dnode_rm_spill(dn, tx); 726 } 727 rw_exit(&dn->dn_struct_rwlock); 728 729 /* change type */ 730 dn->dn_type = ot; 731 732 /* change bonus size and type */ 733 mutex_enter(&dn->dn_mtx); 734 dn->dn_bonustype = bonustype; 735 dn->dn_bonuslen = bonuslen; 736 dn->dn_num_slots = dn_slots; 737 dn->dn_nblkptr = nblkptr; 738 dn->dn_checksum = ZIO_CHECKSUM_INHERIT; 739 dn->dn_compress = ZIO_COMPRESS_INHERIT; 740 ASSERT3U(dn->dn_nblkptr, <=, DN_MAX_NBLKPTR); 741 742 /* fix up the bonus db_size */ 743 if (dn->dn_bonus) { 744 dn->dn_bonus->db.db_size = 745 DN_SLOTS_TO_BONUSLEN(dn->dn_num_slots) - 746 (dn->dn_nblkptr - 1) * sizeof (blkptr_t); 747 ASSERT(dn->dn_bonuslen <= dn->dn_bonus->db.db_size); 748 } 749 750 dn->dn_allocated_txg = tx->tx_txg; 751 mutex_exit(&dn->dn_mtx); 752 } 753 754 #ifdef _KERNEL 755 static void 756 dnode_move_impl(dnode_t *odn, dnode_t *ndn) 757 { 758 int i; 759 760 ASSERT(!RW_LOCK_HELD(&odn->dn_struct_rwlock)); 761 ASSERT(MUTEX_NOT_HELD(&odn->dn_mtx)); 762 ASSERT(MUTEX_NOT_HELD(&odn->dn_dbufs_mtx)); 763 ASSERT(!RW_LOCK_HELD(&odn->dn_zfetch.zf_rwlock)); 764 765 /* Copy fields. */ 766 ndn->dn_objset = odn->dn_objset; 767 ndn->dn_object = odn->dn_object; 768 ndn->dn_dbuf = odn->dn_dbuf; 769 ndn->dn_handle = odn->dn_handle; 770 ndn->dn_phys = odn->dn_phys; 771 ndn->dn_type = odn->dn_type; 772 ndn->dn_bonuslen = odn->dn_bonuslen; 773 ndn->dn_bonustype = odn->dn_bonustype; 774 ndn->dn_nblkptr = odn->dn_nblkptr; 775 ndn->dn_checksum = odn->dn_checksum; 776 ndn->dn_compress = odn->dn_compress; 777 ndn->dn_nlevels = odn->dn_nlevels; 778 ndn->dn_indblkshift = odn->dn_indblkshift; 779 ndn->dn_datablkshift = odn->dn_datablkshift; 780 ndn->dn_datablkszsec = odn->dn_datablkszsec; 781 ndn->dn_datablksz = odn->dn_datablksz; 782 ndn->dn_maxblkid = odn->dn_maxblkid; 783 ndn->dn_num_slots = odn->dn_num_slots; 784 bcopy(&odn->dn_next_type[0], &ndn->dn_next_type[0], 785 sizeof (odn->dn_next_type)); 786 bcopy(&odn->dn_next_nblkptr[0], &ndn->dn_next_nblkptr[0], 787 sizeof (odn->dn_next_nblkptr)); 788 bcopy(&odn->dn_next_nlevels[0], &ndn->dn_next_nlevels[0], 789 sizeof (odn->dn_next_nlevels)); 790 bcopy(&odn->dn_next_indblkshift[0], &ndn->dn_next_indblkshift[0], 791 sizeof (odn->dn_next_indblkshift)); 792 bcopy(&odn->dn_next_bonustype[0], &ndn->dn_next_bonustype[0], 793 sizeof (odn->dn_next_bonustype)); 794 bcopy(&odn->dn_rm_spillblk[0], &ndn->dn_rm_spillblk[0], 795 sizeof (odn->dn_rm_spillblk)); 796 bcopy(&odn->dn_next_bonuslen[0], &ndn->dn_next_bonuslen[0], 797 sizeof (odn->dn_next_bonuslen)); 798 bcopy(&odn->dn_next_blksz[0], &ndn->dn_next_blksz[0], 799 sizeof (odn->dn_next_blksz)); 800 bcopy(&odn->dn_next_maxblkid[0], &ndn->dn_next_maxblkid[0], 801 sizeof (odn->dn_next_maxblkid)); 802 for (i = 0; i < TXG_SIZE; i++) { 803 list_move_tail(&ndn->dn_dirty_records[i], 804 &odn->dn_dirty_records[i]); 805 } 806 bcopy(&odn->dn_free_ranges[0], &ndn->dn_free_ranges[0], 807 sizeof (odn->dn_free_ranges)); 808 ndn->dn_allocated_txg = odn->dn_allocated_txg; 809 ndn->dn_free_txg = odn->dn_free_txg; 810 ndn->dn_assigned_txg = odn->dn_assigned_txg; 811 ndn->dn_dirty_txg = odn->dn_dirty_txg; 812 ndn->dn_dirtyctx = odn->dn_dirtyctx; 813 ndn->dn_dirtyctx_firstset = odn->dn_dirtyctx_firstset; 814 ASSERT(zfs_refcount_count(&odn->dn_tx_holds) == 0); 815 zfs_refcount_transfer(&ndn->dn_holds, &odn->dn_holds); 816 ASSERT(avl_is_empty(&ndn->dn_dbufs)); 817 avl_swap(&ndn->dn_dbufs, &odn->dn_dbufs); 818 ndn->dn_dbufs_count = odn->dn_dbufs_count; 819 ndn->dn_bonus = odn->dn_bonus; 820 ndn->dn_have_spill = odn->dn_have_spill; 821 ndn->dn_zio = odn->dn_zio; 822 ndn->dn_oldused = odn->dn_oldused; 823 ndn->dn_oldflags = odn->dn_oldflags; 824 ndn->dn_olduid = odn->dn_olduid; 825 ndn->dn_oldgid = odn->dn_oldgid; 826 ndn->dn_oldprojid = odn->dn_oldprojid; 827 ndn->dn_newuid = odn->dn_newuid; 828 ndn->dn_newgid = odn->dn_newgid; 829 ndn->dn_newprojid = odn->dn_newprojid; 830 ndn->dn_id_flags = odn->dn_id_flags; 831 dmu_zfetch_init(&ndn->dn_zfetch, NULL); 832 list_move_tail(&ndn->dn_zfetch.zf_stream, &odn->dn_zfetch.zf_stream); 833 ndn->dn_zfetch.zf_dnode = odn->dn_zfetch.zf_dnode; 834 835 /* 836 * Update back pointers. Updating the handle fixes the back pointer of 837 * every descendant dbuf as well as the bonus dbuf. 838 */ 839 ASSERT(ndn->dn_handle->dnh_dnode == odn); 840 ndn->dn_handle->dnh_dnode = ndn; 841 if (ndn->dn_zfetch.zf_dnode == odn) { 842 ndn->dn_zfetch.zf_dnode = ndn; 843 } 844 845 /* 846 * Invalidate the original dnode by clearing all of its back pointers. 847 */ 848 odn->dn_dbuf = NULL; 849 odn->dn_handle = NULL; 850 avl_create(&odn->dn_dbufs, dbuf_compare, sizeof (dmu_buf_impl_t), 851 offsetof(dmu_buf_impl_t, db_link)); 852 odn->dn_dbufs_count = 0; 853 odn->dn_bonus = NULL; 854 odn->dn_zfetch.zf_dnode = NULL; 855 856 /* 857 * Set the low bit of the objset pointer to ensure that dnode_move() 858 * recognizes the dnode as invalid in any subsequent callback. 859 */ 860 POINTER_INVALIDATE(&odn->dn_objset); 861 862 /* 863 * Satisfy the destructor. 864 */ 865 for (i = 0; i < TXG_SIZE; i++) { 866 list_create(&odn->dn_dirty_records[i], 867 sizeof (dbuf_dirty_record_t), 868 offsetof(dbuf_dirty_record_t, dr_dirty_node)); 869 odn->dn_free_ranges[i] = NULL; 870 odn->dn_next_nlevels[i] = 0; 871 odn->dn_next_indblkshift[i] = 0; 872 odn->dn_next_bonustype[i] = 0; 873 odn->dn_rm_spillblk[i] = 0; 874 odn->dn_next_bonuslen[i] = 0; 875 odn->dn_next_blksz[i] = 0; 876 } 877 odn->dn_allocated_txg = 0; 878 odn->dn_free_txg = 0; 879 odn->dn_assigned_txg = 0; 880 odn->dn_dirty_txg = 0; 881 odn->dn_dirtyctx = 0; 882 odn->dn_dirtyctx_firstset = NULL; 883 odn->dn_have_spill = B_FALSE; 884 odn->dn_zio = NULL; 885 odn->dn_oldused = 0; 886 odn->dn_oldflags = 0; 887 odn->dn_olduid = 0; 888 odn->dn_oldgid = 0; 889 odn->dn_oldprojid = ZFS_DEFAULT_PROJID; 890 odn->dn_newuid = 0; 891 odn->dn_newgid = 0; 892 odn->dn_newprojid = ZFS_DEFAULT_PROJID; 893 odn->dn_id_flags = 0; 894 895 /* 896 * Mark the dnode. 897 */ 898 ndn->dn_moved = 1; 899 odn->dn_moved = (uint8_t)-1; 900 } 901 902 /*ARGSUSED*/ 903 static kmem_cbrc_t 904 dnode_move(void *buf, void *newbuf, size_t size, void *arg) 905 { 906 dnode_t *odn = buf, *ndn = newbuf; 907 objset_t *os; 908 int64_t refcount; 909 uint32_t dbufs; 910 911 /* 912 * The dnode is on the objset's list of known dnodes if the objset 913 * pointer is valid. We set the low bit of the objset pointer when 914 * freeing the dnode to invalidate it, and the memory patterns written 915 * by kmem (baddcafe and deadbeef) set at least one of the two low bits. 916 * A newly created dnode sets the objset pointer last of all to indicate 917 * that the dnode is known and in a valid state to be moved by this 918 * function. 919 */ 920 os = odn->dn_objset; 921 if (!POINTER_IS_VALID(os)) { 922 DNODE_STAT_BUMP(dnode_move_invalid); 923 return (KMEM_CBRC_DONT_KNOW); 924 } 925 926 /* 927 * Ensure that the objset does not go away during the move. 928 */ 929 rw_enter(&os_lock, RW_WRITER); 930 if (os != odn->dn_objset) { 931 rw_exit(&os_lock); 932 DNODE_STAT_BUMP(dnode_move_recheck1); 933 return (KMEM_CBRC_DONT_KNOW); 934 } 935 936 /* 937 * If the dnode is still valid, then so is the objset. We know that no 938 * valid objset can be freed while we hold os_lock, so we can safely 939 * ensure that the objset remains in use. 940 */ 941 mutex_enter(&os->os_lock); 942 943 /* 944 * Recheck the objset pointer in case the dnode was removed just before 945 * acquiring the lock. 946 */ 947 if (os != odn->dn_objset) { 948 mutex_exit(&os->os_lock); 949 rw_exit(&os_lock); 950 DNODE_STAT_BUMP(dnode_move_recheck2); 951 return (KMEM_CBRC_DONT_KNOW); 952 } 953 954 /* 955 * At this point we know that as long as we hold os->os_lock, the dnode 956 * cannot be freed and fields within the dnode can be safely accessed. 957 * The objset listing this dnode cannot go away as long as this dnode is 958 * on its list. 959 */ 960 rw_exit(&os_lock); 961 if (DMU_OBJECT_IS_SPECIAL(odn->dn_object)) { 962 mutex_exit(&os->os_lock); 963 DNODE_STAT_BUMP(dnode_move_special); 964 return (KMEM_CBRC_NO); 965 } 966 ASSERT(odn->dn_dbuf != NULL); /* only "special" dnodes have no parent */ 967 968 /* 969 * Lock the dnode handle to prevent the dnode from obtaining any new 970 * holds. This also prevents the descendant dbufs and the bonus dbuf 971 * from accessing the dnode, so that we can discount their holds. The 972 * handle is safe to access because we know that while the dnode cannot 973 * go away, neither can its handle. Once we hold dnh_zrlock, we can 974 * safely move any dnode referenced only by dbufs. 975 */ 976 if (!zrl_tryenter(&odn->dn_handle->dnh_zrlock)) { 977 mutex_exit(&os->os_lock); 978 DNODE_STAT_BUMP(dnode_move_handle); 979 return (KMEM_CBRC_LATER); 980 } 981 982 /* 983 * Ensure a consistent view of the dnode's holds and the dnode's dbufs. 984 * We need to guarantee that there is a hold for every dbuf in order to 985 * determine whether the dnode is actively referenced. Falsely matching 986 * a dbuf to an active hold would lead to an unsafe move. It's possible 987 * that a thread already having an active dnode hold is about to add a 988 * dbuf, and we can't compare hold and dbuf counts while the add is in 989 * progress. 990 */ 991 if (!rw_tryenter(&odn->dn_struct_rwlock, RW_WRITER)) { 992 zrl_exit(&odn->dn_handle->dnh_zrlock); 993 mutex_exit(&os->os_lock); 994 DNODE_STAT_BUMP(dnode_move_rwlock); 995 return (KMEM_CBRC_LATER); 996 } 997 998 /* 999 * A dbuf may be removed (evicted) without an active dnode hold. In that 1000 * case, the dbuf count is decremented under the handle lock before the 1001 * dbuf's hold is released. This order ensures that if we count the hold 1002 * after the dbuf is removed but before its hold is released, we will 1003 * treat the unmatched hold as active and exit safely. If we count the 1004 * hold before the dbuf is removed, the hold is discounted, and the 1005 * removal is blocked until the move completes. 1006 */ 1007 refcount = zfs_refcount_count(&odn->dn_holds); 1008 ASSERT(refcount >= 0); 1009 dbufs = odn->dn_dbufs_count; 1010 1011 /* We can't have more dbufs than dnode holds. */ 1012 ASSERT3U(dbufs, <=, refcount); 1013 DTRACE_PROBE3(dnode__move, dnode_t *, odn, int64_t, refcount, 1014 uint32_t, dbufs); 1015 1016 if (refcount > dbufs) { 1017 rw_exit(&odn->dn_struct_rwlock); 1018 zrl_exit(&odn->dn_handle->dnh_zrlock); 1019 mutex_exit(&os->os_lock); 1020 DNODE_STAT_BUMP(dnode_move_active); 1021 return (KMEM_CBRC_LATER); 1022 } 1023 1024 rw_exit(&odn->dn_struct_rwlock); 1025 1026 /* 1027 * At this point we know that anyone with a hold on the dnode is not 1028 * actively referencing it. The dnode is known and in a valid state to 1029 * move. We're holding the locks needed to execute the critical section. 1030 */ 1031 dnode_move_impl(odn, ndn); 1032 1033 list_link_replace(&odn->dn_link, &ndn->dn_link); 1034 /* If the dnode was safe to move, the refcount cannot have changed. */ 1035 ASSERT(refcount == zfs_refcount_count(&ndn->dn_holds)); 1036 ASSERT(dbufs == ndn->dn_dbufs_count); 1037 zrl_exit(&ndn->dn_handle->dnh_zrlock); /* handle has moved */ 1038 mutex_exit(&os->os_lock); 1039 1040 return (KMEM_CBRC_YES); 1041 } 1042 #endif /* _KERNEL */ 1043 1044 static void 1045 dnode_slots_hold(dnode_children_t *children, int idx, int slots) 1046 { 1047 ASSERT3S(idx + slots, <=, DNODES_PER_BLOCK); 1048 1049 for (int i = idx; i < idx + slots; i++) { 1050 dnode_handle_t *dnh = &children->dnc_children[i]; 1051 zrl_add(&dnh->dnh_zrlock); 1052 } 1053 } 1054 1055 static void 1056 dnode_slots_rele(dnode_children_t *children, int idx, int slots) 1057 { 1058 ASSERT3S(idx + slots, <=, DNODES_PER_BLOCK); 1059 1060 for (int i = idx; i < idx + slots; i++) { 1061 dnode_handle_t *dnh = &children->dnc_children[i]; 1062 1063 if (zrl_is_locked(&dnh->dnh_zrlock)) 1064 zrl_exit(&dnh->dnh_zrlock); 1065 else 1066 zrl_remove(&dnh->dnh_zrlock); 1067 } 1068 } 1069 1070 static int 1071 dnode_slots_tryenter(dnode_children_t *children, int idx, int slots) 1072 { 1073 ASSERT3S(idx + slots, <=, DNODES_PER_BLOCK); 1074 1075 for (int i = idx; i < idx + slots; i++) { 1076 dnode_handle_t *dnh = &children->dnc_children[i]; 1077 1078 if (!zrl_tryenter(&dnh->dnh_zrlock)) { 1079 for (int j = idx; j < i; j++) { 1080 dnh = &children->dnc_children[j]; 1081 zrl_exit(&dnh->dnh_zrlock); 1082 } 1083 1084 return (0); 1085 } 1086 } 1087 1088 return (1); 1089 } 1090 1091 static void 1092 dnode_set_slots(dnode_children_t *children, int idx, int slots, void *ptr) 1093 { 1094 ASSERT3S(idx + slots, <=, DNODES_PER_BLOCK); 1095 1096 for (int i = idx; i < idx + slots; i++) { 1097 dnode_handle_t *dnh = &children->dnc_children[i]; 1098 dnh->dnh_dnode = ptr; 1099 } 1100 } 1101 1102 static boolean_t 1103 dnode_check_slots_free(dnode_children_t *children, int idx, int slots) 1104 { 1105 ASSERT3S(idx + slots, <=, DNODES_PER_BLOCK); 1106 1107 /* 1108 * If all dnode slots are either already free or 1109 * evictable return B_TRUE. 1110 */ 1111 for (int i = idx; i < idx + slots; i++) { 1112 dnode_handle_t *dnh = &children->dnc_children[i]; 1113 dnode_t *dn = dnh->dnh_dnode; 1114 1115 if (dn == DN_SLOT_FREE) { 1116 continue; 1117 } else if (DN_SLOT_IS_PTR(dn)) { 1118 mutex_enter(&dn->dn_mtx); 1119 boolean_t can_free = (dn->dn_type == DMU_OT_NONE && 1120 zfs_refcount_is_zero(&dn->dn_holds) && 1121 !DNODE_IS_DIRTY(dn)); 1122 mutex_exit(&dn->dn_mtx); 1123 1124 if (!can_free) 1125 return (B_FALSE); 1126 else 1127 continue; 1128 } else { 1129 return (B_FALSE); 1130 } 1131 } 1132 1133 return (B_TRUE); 1134 } 1135 1136 static void 1137 dnode_reclaim_slots(dnode_children_t *children, int idx, int slots) 1138 { 1139 ASSERT3S(idx + slots, <=, DNODES_PER_BLOCK); 1140 1141 for (int i = idx; i < idx + slots; i++) { 1142 dnode_handle_t *dnh = &children->dnc_children[i]; 1143 1144 ASSERT(zrl_is_locked(&dnh->dnh_zrlock)); 1145 1146 if (DN_SLOT_IS_PTR(dnh->dnh_dnode)) { 1147 ASSERT3S(dnh->dnh_dnode->dn_type, ==, DMU_OT_NONE); 1148 dnode_destroy(dnh->dnh_dnode); 1149 dnh->dnh_dnode = DN_SLOT_FREE; 1150 } 1151 } 1152 } 1153 1154 void 1155 dnode_free_interior_slots(dnode_t *dn) 1156 { 1157 dnode_children_t *children = dmu_buf_get_user(&dn->dn_dbuf->db); 1158 int epb = dn->dn_dbuf->db.db_size >> DNODE_SHIFT; 1159 int idx = (dn->dn_object & (epb - 1)) + 1; 1160 int slots = dn->dn_num_slots - 1; 1161 1162 if (slots == 0) 1163 return; 1164 1165 ASSERT3S(idx + slots, <=, DNODES_PER_BLOCK); 1166 1167 while (!dnode_slots_tryenter(children, idx, slots)) 1168 DNODE_STAT_BUMP(dnode_free_interior_lock_retry); 1169 1170 dnode_set_slots(children, idx, slots, DN_SLOT_FREE); 1171 dnode_slots_rele(children, idx, slots); 1172 } 1173 1174 void 1175 dnode_special_close(dnode_handle_t *dnh) 1176 { 1177 dnode_t *dn = dnh->dnh_dnode; 1178 1179 /* 1180 * Ensure dnode_rele_and_unlock() has released dn_mtx, after final 1181 * zfs_refcount_remove() 1182 */ 1183 mutex_enter(&dn->dn_mtx); 1184 if (zfs_refcount_count(&dn->dn_holds) > 0) 1185 cv_wait(&dn->dn_nodnholds, &dn->dn_mtx); 1186 mutex_exit(&dn->dn_mtx); 1187 ASSERT3U(zfs_refcount_count(&dn->dn_holds), ==, 0); 1188 1189 ASSERT(dn->dn_dbuf == NULL || 1190 dmu_buf_get_user(&dn->dn_dbuf->db) == NULL); 1191 zrl_add(&dnh->dnh_zrlock); 1192 dnode_destroy(dn); /* implicit zrl_remove() */ 1193 zrl_destroy(&dnh->dnh_zrlock); 1194 dnh->dnh_dnode = NULL; 1195 } 1196 1197 void 1198 dnode_special_open(objset_t *os, dnode_phys_t *dnp, uint64_t object, 1199 dnode_handle_t *dnh) 1200 { 1201 dnode_t *dn; 1202 1203 zrl_init(&dnh->dnh_zrlock); 1204 VERIFY3U(1, ==, zrl_tryenter(&dnh->dnh_zrlock)); 1205 1206 dn = dnode_create(os, dnp, NULL, object, dnh); 1207 DNODE_VERIFY(dn); 1208 1209 zrl_exit(&dnh->dnh_zrlock); 1210 } 1211 1212 static void 1213 dnode_buf_evict_async(void *dbu) 1214 { 1215 dnode_children_t *dnc = dbu; 1216 1217 DNODE_STAT_BUMP(dnode_buf_evict); 1218 1219 for (int i = 0; i < dnc->dnc_count; i++) { 1220 dnode_handle_t *dnh = &dnc->dnc_children[i]; 1221 dnode_t *dn; 1222 1223 /* 1224 * The dnode handle lock guards against the dnode moving to 1225 * another valid address, so there is no need here to guard 1226 * against changes to or from NULL. 1227 */ 1228 if (!DN_SLOT_IS_PTR(dnh->dnh_dnode)) { 1229 zrl_destroy(&dnh->dnh_zrlock); 1230 dnh->dnh_dnode = DN_SLOT_UNINIT; 1231 continue; 1232 } 1233 1234 zrl_add(&dnh->dnh_zrlock); 1235 dn = dnh->dnh_dnode; 1236 /* 1237 * If there are holds on this dnode, then there should 1238 * be holds on the dnode's containing dbuf as well; thus 1239 * it wouldn't be eligible for eviction and this function 1240 * would not have been called. 1241 */ 1242 ASSERT(zfs_refcount_is_zero(&dn->dn_holds)); 1243 ASSERT(zfs_refcount_is_zero(&dn->dn_tx_holds)); 1244 1245 dnode_destroy(dn); /* implicit zrl_remove() for first slot */ 1246 zrl_destroy(&dnh->dnh_zrlock); 1247 dnh->dnh_dnode = DN_SLOT_UNINIT; 1248 } 1249 kmem_free(dnc, sizeof (dnode_children_t) + 1250 dnc->dnc_count * sizeof (dnode_handle_t)); 1251 } 1252 1253 /* 1254 * When the DNODE_MUST_BE_FREE flag is set, the "slots" parameter is used 1255 * to ensure the hole at the specified object offset is large enough to 1256 * hold the dnode being created. The slots parameter is also used to ensure 1257 * a dnode does not span multiple dnode blocks. In both of these cases, if 1258 * a failure occurs, ENOSPC is returned. Keep in mind, these failure cases 1259 * are only possible when using DNODE_MUST_BE_FREE. 1260 * 1261 * If the DNODE_MUST_BE_ALLOCATED flag is set, "slots" must be 0. 1262 * dnode_hold_impl() will check if the requested dnode is already consumed 1263 * as an extra dnode slot by an large dnode, in which case it returns 1264 * ENOENT. 1265 * 1266 * If the DNODE_DRY_RUN flag is set, we don't actually hold the dnode, just 1267 * return whether the hold would succeed or not. tag and dnp should set to 1268 * NULL in this case. 1269 * 1270 * errors: 1271 * EINVAL - invalid object number or flags. 1272 * ENOSPC - hole too small to fulfill "slots" request (DNODE_MUST_BE_FREE) 1273 * EEXIST - Refers to an allocated dnode (DNODE_MUST_BE_FREE) 1274 * - Refers to a freeing dnode (DNODE_MUST_BE_FREE) 1275 * - Refers to an interior dnode slot (DNODE_MUST_BE_ALLOCATED) 1276 * ENOENT - The requested dnode is not allocated (DNODE_MUST_BE_ALLOCATED) 1277 * - The requested dnode is being freed (DNODE_MUST_BE_ALLOCATED) 1278 * EIO - i/o error error when reading the meta dnode dbuf. 1279 * succeeds even for free dnodes. 1280 */ 1281 int 1282 dnode_hold_impl(objset_t *os, uint64_t object, int flag, int slots, 1283 void *tag, dnode_t **dnp) 1284 { 1285 int epb, idx, err; 1286 int drop_struct_lock = FALSE; 1287 int type; 1288 uint64_t blk; 1289 dnode_t *mdn, *dn; 1290 dmu_buf_impl_t *db; 1291 dnode_children_t *dnc; 1292 dnode_phys_t *dn_block; 1293 dnode_handle_t *dnh; 1294 1295 ASSERT(!(flag & DNODE_MUST_BE_ALLOCATED) || (slots == 0)); 1296 ASSERT(!(flag & DNODE_MUST_BE_FREE) || (slots > 0)); 1297 IMPLY(flag & DNODE_DRY_RUN, (tag == NULL) && (dnp == NULL)); 1298 1299 /* 1300 * If you are holding the spa config lock as writer, you shouldn't 1301 * be asking the DMU to do *anything* unless it's the root pool 1302 * which may require us to read from the root filesystem while 1303 * holding some (not all) of the locks as writer. 1304 */ 1305 ASSERT(spa_config_held(os->os_spa, SCL_ALL, RW_WRITER) == 0 || 1306 (spa_is_root(os->os_spa) && 1307 spa_config_held(os->os_spa, SCL_STATE, RW_WRITER))); 1308 1309 ASSERT((flag & DNODE_MUST_BE_ALLOCATED) || (flag & DNODE_MUST_BE_FREE)); 1310 1311 if (object == DMU_USERUSED_OBJECT || object == DMU_GROUPUSED_OBJECT || 1312 object == DMU_PROJECTUSED_OBJECT) { 1313 if (object == DMU_USERUSED_OBJECT) 1314 dn = DMU_USERUSED_DNODE(os); 1315 else if (object == DMU_GROUPUSED_OBJECT) 1316 dn = DMU_GROUPUSED_DNODE(os); 1317 else 1318 dn = DMU_PROJECTUSED_DNODE(os); 1319 if (dn == NULL) 1320 return (SET_ERROR(ENOENT)); 1321 type = dn->dn_type; 1322 if ((flag & DNODE_MUST_BE_ALLOCATED) && type == DMU_OT_NONE) 1323 return (SET_ERROR(ENOENT)); 1324 if ((flag & DNODE_MUST_BE_FREE) && type != DMU_OT_NONE) 1325 return (SET_ERROR(EEXIST)); 1326 DNODE_VERIFY(dn); 1327 /* Don't actually hold if dry run, just return 0 */ 1328 if (!(flag & DNODE_DRY_RUN)) { 1329 (void) zfs_refcount_add(&dn->dn_holds, tag); 1330 *dnp = dn; 1331 } 1332 return (0); 1333 } 1334 1335 if (object == 0 || object >= DN_MAX_OBJECT) 1336 return (SET_ERROR(EINVAL)); 1337 1338 mdn = DMU_META_DNODE(os); 1339 ASSERT(mdn->dn_object == DMU_META_DNODE_OBJECT); 1340 1341 DNODE_VERIFY(mdn); 1342 1343 if (!RW_WRITE_HELD(&mdn->dn_struct_rwlock)) { 1344 rw_enter(&mdn->dn_struct_rwlock, RW_READER); 1345 drop_struct_lock = TRUE; 1346 } 1347 1348 blk = dbuf_whichblock(mdn, 0, object * sizeof (dnode_phys_t)); 1349 1350 db = dbuf_hold(mdn, blk, FTAG); 1351 if (drop_struct_lock) 1352 rw_exit(&mdn->dn_struct_rwlock); 1353 if (db == NULL) { 1354 DNODE_STAT_BUMP(dnode_hold_dbuf_hold); 1355 return (SET_ERROR(EIO)); 1356 } 1357 /* 1358 * We do not need to decrypt to read the dnode so it doesn't matter 1359 * if we get the encrypted or decrypted version. 1360 */ 1361 err = dbuf_read(db, NULL, DB_RF_CANFAIL | DB_RF_NO_DECRYPT); 1362 if (err) { 1363 DNODE_STAT_BUMP(dnode_hold_dbuf_read); 1364 dbuf_rele(db, FTAG); 1365 return (err); 1366 } 1367 1368 ASSERT3U(db->db.db_size, >=, 1<<DNODE_SHIFT); 1369 epb = db->db.db_size >> DNODE_SHIFT; 1370 1371 idx = object & (epb - 1); 1372 dn_block = (dnode_phys_t *)db->db.db_data; 1373 1374 ASSERT(DB_DNODE(db)->dn_type == DMU_OT_DNODE); 1375 dnc = dmu_buf_get_user(&db->db); 1376 dnh = NULL; 1377 if (dnc == NULL) { 1378 dnode_children_t *winner; 1379 int skip = 0; 1380 1381 dnc = kmem_zalloc(sizeof (dnode_children_t) + 1382 epb * sizeof (dnode_handle_t), KM_SLEEP); 1383 dnc->dnc_count = epb; 1384 dnh = &dnc->dnc_children[0]; 1385 1386 /* Initialize dnode slot status from dnode_phys_t */ 1387 for (int i = 0; i < epb; i++) { 1388 zrl_init(&dnh[i].dnh_zrlock); 1389 1390 if (skip) { 1391 skip--; 1392 continue; 1393 } 1394 1395 if (dn_block[i].dn_type != DMU_OT_NONE) { 1396 int interior = dn_block[i].dn_extra_slots; 1397 1398 dnode_set_slots(dnc, i, 1, DN_SLOT_ALLOCATED); 1399 dnode_set_slots(dnc, i + 1, interior, 1400 DN_SLOT_INTERIOR); 1401 skip = interior; 1402 } else { 1403 dnh[i].dnh_dnode = DN_SLOT_FREE; 1404 skip = 0; 1405 } 1406 } 1407 1408 dmu_buf_init_user(&dnc->dnc_dbu, NULL, 1409 dnode_buf_evict_async, NULL); 1410 winner = dmu_buf_set_user(&db->db, &dnc->dnc_dbu); 1411 if (winner != NULL) { 1412 1413 for (int i = 0; i < epb; i++) 1414 zrl_destroy(&dnh[i].dnh_zrlock); 1415 1416 kmem_free(dnc, sizeof (dnode_children_t) + 1417 epb * sizeof (dnode_handle_t)); 1418 dnc = winner; 1419 } 1420 } 1421 1422 ASSERT(dnc->dnc_count == epb); 1423 dn = DN_SLOT_UNINIT; 1424 1425 if (flag & DNODE_MUST_BE_ALLOCATED) { 1426 slots = 1; 1427 1428 while (dn == DN_SLOT_UNINIT) { 1429 dnode_slots_hold(dnc, idx, slots); 1430 dnh = &dnc->dnc_children[idx]; 1431 1432 if (DN_SLOT_IS_PTR(dnh->dnh_dnode)) { 1433 dn = dnh->dnh_dnode; 1434 break; 1435 } else if (dnh->dnh_dnode == DN_SLOT_INTERIOR) { 1436 DNODE_STAT_BUMP(dnode_hold_alloc_interior); 1437 dnode_slots_rele(dnc, idx, slots); 1438 dbuf_rele(db, FTAG); 1439 return (SET_ERROR(EEXIST)); 1440 } else if (dnh->dnh_dnode != DN_SLOT_ALLOCATED) { 1441 DNODE_STAT_BUMP(dnode_hold_alloc_misses); 1442 dnode_slots_rele(dnc, idx, slots); 1443 dbuf_rele(db, FTAG); 1444 return (SET_ERROR(ENOENT)); 1445 } 1446 1447 dnode_slots_rele(dnc, idx, slots); 1448 if (!dnode_slots_tryenter(dnc, idx, slots)) { 1449 DNODE_STAT_BUMP(dnode_hold_alloc_lock_retry); 1450 continue; 1451 } 1452 1453 /* 1454 * Someone else won the race and called dnode_create() 1455 * after we checked DN_SLOT_IS_PTR() above but before 1456 * we acquired the lock. 1457 */ 1458 if (DN_SLOT_IS_PTR(dnh->dnh_dnode)) { 1459 DNODE_STAT_BUMP(dnode_hold_alloc_lock_misses); 1460 dn = dnh->dnh_dnode; 1461 } else { 1462 dn = dnode_create(os, dn_block + idx, db, 1463 object, dnh); 1464 } 1465 } 1466 1467 mutex_enter(&dn->dn_mtx); 1468 if (dn->dn_type == DMU_OT_NONE || dn->dn_free_txg != 0) { 1469 DNODE_STAT_BUMP(dnode_hold_alloc_type_none); 1470 mutex_exit(&dn->dn_mtx); 1471 dnode_slots_rele(dnc, idx, slots); 1472 dbuf_rele(db, FTAG); 1473 return (SET_ERROR(ENOENT)); 1474 } 1475 1476 /* Don't actually hold if dry run, just return 0 */ 1477 if (flag & DNODE_DRY_RUN) { 1478 mutex_exit(&dn->dn_mtx); 1479 dnode_slots_rele(dnc, idx, slots); 1480 dbuf_rele(db, FTAG); 1481 return (0); 1482 } 1483 1484 DNODE_STAT_BUMP(dnode_hold_alloc_hits); 1485 } else if (flag & DNODE_MUST_BE_FREE) { 1486 1487 if (idx + slots - 1 >= DNODES_PER_BLOCK) { 1488 DNODE_STAT_BUMP(dnode_hold_free_overflow); 1489 dbuf_rele(db, FTAG); 1490 return (SET_ERROR(ENOSPC)); 1491 } 1492 1493 while (dn == DN_SLOT_UNINIT) { 1494 dnode_slots_hold(dnc, idx, slots); 1495 1496 if (!dnode_check_slots_free(dnc, idx, slots)) { 1497 DNODE_STAT_BUMP(dnode_hold_free_misses); 1498 dnode_slots_rele(dnc, idx, slots); 1499 dbuf_rele(db, FTAG); 1500 return (SET_ERROR(ENOSPC)); 1501 } 1502 1503 dnode_slots_rele(dnc, idx, slots); 1504 if (!dnode_slots_tryenter(dnc, idx, slots)) { 1505 DNODE_STAT_BUMP(dnode_hold_free_lock_retry); 1506 continue; 1507 } 1508 1509 if (!dnode_check_slots_free(dnc, idx, slots)) { 1510 DNODE_STAT_BUMP(dnode_hold_free_lock_misses); 1511 dnode_slots_rele(dnc, idx, slots); 1512 dbuf_rele(db, FTAG); 1513 return (SET_ERROR(ENOSPC)); 1514 } 1515 1516 /* 1517 * Allocated but otherwise free dnodes which would 1518 * be in the interior of a multi-slot dnodes need 1519 * to be freed. Single slot dnodes can be safely 1520 * re-purposed as a performance optimization. 1521 */ 1522 if (slots > 1) 1523 dnode_reclaim_slots(dnc, idx + 1, slots - 1); 1524 1525 dnh = &dnc->dnc_children[idx]; 1526 if (DN_SLOT_IS_PTR(dnh->dnh_dnode)) { 1527 dn = dnh->dnh_dnode; 1528 } else { 1529 dn = dnode_create(os, dn_block + idx, db, 1530 object, dnh); 1531 } 1532 } 1533 1534 mutex_enter(&dn->dn_mtx); 1535 if (!zfs_refcount_is_zero(&dn->dn_holds) || dn->dn_free_txg) { 1536 DNODE_STAT_BUMP(dnode_hold_free_refcount); 1537 mutex_exit(&dn->dn_mtx); 1538 dnode_slots_rele(dnc, idx, slots); 1539 dbuf_rele(db, FTAG); 1540 return (SET_ERROR(EEXIST)); 1541 } 1542 1543 /* Don't actually hold if dry run, just return 0 */ 1544 if (flag & DNODE_DRY_RUN) { 1545 mutex_exit(&dn->dn_mtx); 1546 dnode_slots_rele(dnc, idx, slots); 1547 dbuf_rele(db, FTAG); 1548 return (0); 1549 } 1550 1551 dnode_set_slots(dnc, idx + 1, slots - 1, DN_SLOT_INTERIOR); 1552 DNODE_STAT_BUMP(dnode_hold_free_hits); 1553 } else { 1554 dbuf_rele(db, FTAG); 1555 return (SET_ERROR(EINVAL)); 1556 } 1557 1558 ASSERT0(dn->dn_free_txg); 1559 1560 if (zfs_refcount_add(&dn->dn_holds, tag) == 1) 1561 dbuf_add_ref(db, dnh); 1562 1563 mutex_exit(&dn->dn_mtx); 1564 1565 /* Now we can rely on the hold to prevent the dnode from moving. */ 1566 dnode_slots_rele(dnc, idx, slots); 1567 1568 DNODE_VERIFY(dn); 1569 ASSERT3P(dn->dn_dbuf, ==, db); 1570 ASSERT3U(dn->dn_object, ==, object); 1571 dbuf_rele(db, FTAG); 1572 1573 *dnp = dn; 1574 return (0); 1575 } 1576 1577 /* 1578 * Return held dnode if the object is allocated, NULL if not. 1579 */ 1580 int 1581 dnode_hold(objset_t *os, uint64_t object, void *tag, dnode_t **dnp) 1582 { 1583 return (dnode_hold_impl(os, object, DNODE_MUST_BE_ALLOCATED, 0, tag, 1584 dnp)); 1585 } 1586 1587 /* 1588 * Can only add a reference if there is already at least one 1589 * reference on the dnode. Returns FALSE if unable to add a 1590 * new reference. 1591 */ 1592 boolean_t 1593 dnode_add_ref(dnode_t *dn, void *tag) 1594 { 1595 mutex_enter(&dn->dn_mtx); 1596 if (zfs_refcount_is_zero(&dn->dn_holds)) { 1597 mutex_exit(&dn->dn_mtx); 1598 return (FALSE); 1599 } 1600 VERIFY(1 < zfs_refcount_add(&dn->dn_holds, tag)); 1601 mutex_exit(&dn->dn_mtx); 1602 return (TRUE); 1603 } 1604 1605 void 1606 dnode_rele(dnode_t *dn, void *tag) 1607 { 1608 mutex_enter(&dn->dn_mtx); 1609 dnode_rele_and_unlock(dn, tag, B_FALSE); 1610 } 1611 1612 void 1613 dnode_rele_and_unlock(dnode_t *dn, void *tag, boolean_t evicting) 1614 { 1615 uint64_t refs; 1616 /* Get while the hold prevents the dnode from moving. */ 1617 dmu_buf_impl_t *db = dn->dn_dbuf; 1618 dnode_handle_t *dnh = dn->dn_handle; 1619 1620 refs = zfs_refcount_remove(&dn->dn_holds, tag); 1621 if (refs == 0) 1622 cv_broadcast(&dn->dn_nodnholds); 1623 mutex_exit(&dn->dn_mtx); 1624 /* dnode could get destroyed at this point, so don't use it anymore */ 1625 1626 /* 1627 * It's unsafe to release the last hold on a dnode by dnode_rele() or 1628 * indirectly by dbuf_rele() while relying on the dnode handle to 1629 * prevent the dnode from moving, since releasing the last hold could 1630 * result in the dnode's parent dbuf evicting its dnode handles. For 1631 * that reason anyone calling dnode_rele() or dbuf_rele() without some 1632 * other direct or indirect hold on the dnode must first drop the dnode 1633 * handle. 1634 */ 1635 ASSERT(refs > 0 || dnh->dnh_zrlock.zr_owner != curthread); 1636 1637 /* NOTE: the DNODE_DNODE does not have a dn_dbuf */ 1638 if (refs == 0 && db != NULL) { 1639 /* 1640 * Another thread could add a hold to the dnode handle in 1641 * dnode_hold_impl() while holding the parent dbuf. Since the 1642 * hold on the parent dbuf prevents the handle from being 1643 * destroyed, the hold on the handle is OK. We can't yet assert 1644 * that the handle has zero references, but that will be 1645 * asserted anyway when the handle gets destroyed. 1646 */ 1647 mutex_enter(&db->db_mtx); 1648 dbuf_rele_and_unlock(db, dnh, evicting); 1649 } 1650 } 1651 1652 /* 1653 * Test whether we can create a dnode at the specified location. 1654 */ 1655 int 1656 dnode_try_claim(objset_t *os, uint64_t object, int slots) 1657 { 1658 return (dnode_hold_impl(os, object, DNODE_MUST_BE_FREE | DNODE_DRY_RUN, 1659 slots, NULL, NULL)); 1660 } 1661 1662 void 1663 dnode_setdirty(dnode_t *dn, dmu_tx_t *tx) 1664 { 1665 objset_t *os = dn->dn_objset; 1666 uint64_t txg = tx->tx_txg; 1667 1668 if (DMU_OBJECT_IS_SPECIAL(dn->dn_object)) { 1669 dsl_dataset_dirty(os->os_dsl_dataset, tx); 1670 return; 1671 } 1672 1673 DNODE_VERIFY(dn); 1674 1675 #ifdef ZFS_DEBUG 1676 mutex_enter(&dn->dn_mtx); 1677 ASSERT(dn->dn_phys->dn_type || dn->dn_allocated_txg); 1678 ASSERT(dn->dn_free_txg == 0 || dn->dn_free_txg >= txg); 1679 mutex_exit(&dn->dn_mtx); 1680 #endif 1681 1682 /* 1683 * Determine old uid/gid when necessary 1684 */ 1685 dmu_objset_userquota_get_ids(dn, B_TRUE, tx); 1686 1687 multilist_t *dirtylist = os->os_dirty_dnodes[txg & TXG_MASK]; 1688 multilist_sublist_t *mls = multilist_sublist_lock_obj(dirtylist, dn); 1689 1690 /* 1691 * If we are already marked dirty, we're done. 1692 */ 1693 if (multilist_link_active(&dn->dn_dirty_link[txg & TXG_MASK])) { 1694 multilist_sublist_unlock(mls); 1695 return; 1696 } 1697 1698 ASSERT(!zfs_refcount_is_zero(&dn->dn_holds) || 1699 !avl_is_empty(&dn->dn_dbufs)); 1700 ASSERT(dn->dn_datablksz != 0); 1701 ASSERT0(dn->dn_next_bonuslen[txg&TXG_MASK]); 1702 ASSERT0(dn->dn_next_blksz[txg&TXG_MASK]); 1703 ASSERT0(dn->dn_next_bonustype[txg&TXG_MASK]); 1704 1705 dprintf_ds(os->os_dsl_dataset, "obj=%llu txg=%llu\n", 1706 dn->dn_object, txg); 1707 1708 multilist_sublist_insert_head(mls, dn); 1709 1710 multilist_sublist_unlock(mls); 1711 1712 /* 1713 * The dnode maintains a hold on its containing dbuf as 1714 * long as there are holds on it. Each instantiated child 1715 * dbuf maintains a hold on the dnode. When the last child 1716 * drops its hold, the dnode will drop its hold on the 1717 * containing dbuf. We add a "dirty hold" here so that the 1718 * dnode will hang around after we finish processing its 1719 * children. 1720 */ 1721 VERIFY(dnode_add_ref(dn, (void *)(uintptr_t)tx->tx_txg)); 1722 1723 (void) dbuf_dirty(dn->dn_dbuf, tx); 1724 1725 dsl_dataset_dirty(os->os_dsl_dataset, tx); 1726 } 1727 1728 void 1729 dnode_free(dnode_t *dn, dmu_tx_t *tx) 1730 { 1731 mutex_enter(&dn->dn_mtx); 1732 if (dn->dn_type == DMU_OT_NONE || dn->dn_free_txg) { 1733 mutex_exit(&dn->dn_mtx); 1734 return; 1735 } 1736 dn->dn_free_txg = tx->tx_txg; 1737 mutex_exit(&dn->dn_mtx); 1738 1739 dnode_setdirty(dn, tx); 1740 } 1741 1742 /* 1743 * Try to change the block size for the indicated dnode. This can only 1744 * succeed if there are no blocks allocated or dirty beyond first block 1745 */ 1746 int 1747 dnode_set_blksz(dnode_t *dn, uint64_t size, int ibs, dmu_tx_t *tx) 1748 { 1749 dmu_buf_impl_t *db; 1750 int err; 1751 1752 ASSERT3U(size, <=, spa_maxblocksize(dmu_objset_spa(dn->dn_objset))); 1753 if (size == 0) 1754 size = SPA_MINBLOCKSIZE; 1755 else 1756 size = P2ROUNDUP(size, SPA_MINBLOCKSIZE); 1757 1758 if (ibs == dn->dn_indblkshift) 1759 ibs = 0; 1760 1761 if (size >> SPA_MINBLOCKSHIFT == dn->dn_datablkszsec && ibs == 0) 1762 return (0); 1763 1764 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 1765 1766 /* Check for any allocated blocks beyond the first */ 1767 if (dn->dn_maxblkid != 0) 1768 goto fail; 1769 1770 mutex_enter(&dn->dn_dbufs_mtx); 1771 for (db = avl_first(&dn->dn_dbufs); db != NULL; 1772 db = AVL_NEXT(&dn->dn_dbufs, db)) { 1773 if (db->db_blkid != 0 && db->db_blkid != DMU_BONUS_BLKID && 1774 db->db_blkid != DMU_SPILL_BLKID) { 1775 mutex_exit(&dn->dn_dbufs_mtx); 1776 goto fail; 1777 } 1778 } 1779 mutex_exit(&dn->dn_dbufs_mtx); 1780 1781 if (ibs && dn->dn_nlevels != 1) 1782 goto fail; 1783 1784 /* resize the old block */ 1785 err = dbuf_hold_impl(dn, 0, 0, TRUE, FALSE, FTAG, &db); 1786 if (err == 0) 1787 dbuf_new_size(db, size, tx); 1788 else if (err != ENOENT) 1789 goto fail; 1790 1791 dnode_setdblksz(dn, size); 1792 dnode_setdirty(dn, tx); 1793 dn->dn_next_blksz[tx->tx_txg&TXG_MASK] = size; 1794 if (ibs) { 1795 dn->dn_indblkshift = ibs; 1796 dn->dn_next_indblkshift[tx->tx_txg&TXG_MASK] = ibs; 1797 } 1798 /* rele after we have fixed the blocksize in the dnode */ 1799 if (db) 1800 dbuf_rele(db, FTAG); 1801 1802 rw_exit(&dn->dn_struct_rwlock); 1803 return (0); 1804 1805 fail: 1806 rw_exit(&dn->dn_struct_rwlock); 1807 return (SET_ERROR(ENOTSUP)); 1808 } 1809 1810 static void 1811 dnode_set_nlevels_impl(dnode_t *dn, int new_nlevels, dmu_tx_t *tx) 1812 { 1813 uint64_t txgoff = tx->tx_txg & TXG_MASK; 1814 int old_nlevels = dn->dn_nlevels; 1815 dmu_buf_impl_t *db; 1816 list_t *list; 1817 dbuf_dirty_record_t *new, *dr, *dr_next; 1818 1819 ASSERT(RW_WRITE_HELD(&dn->dn_struct_rwlock)); 1820 1821 dn->dn_nlevels = new_nlevels; 1822 1823 ASSERT3U(new_nlevels, >, dn->dn_next_nlevels[txgoff]); 1824 dn->dn_next_nlevels[txgoff] = new_nlevels; 1825 1826 /* dirty the left indirects */ 1827 db = dbuf_hold_level(dn, old_nlevels, 0, FTAG); 1828 ASSERT(db != NULL); 1829 new = dbuf_dirty(db, tx); 1830 dbuf_rele(db, FTAG); 1831 1832 /* transfer the dirty records to the new indirect */ 1833 mutex_enter(&dn->dn_mtx); 1834 mutex_enter(&new->dt.di.dr_mtx); 1835 list = &dn->dn_dirty_records[txgoff]; 1836 for (dr = list_head(list); dr; dr = dr_next) { 1837 dr_next = list_next(&dn->dn_dirty_records[txgoff], dr); 1838 if (dr->dr_dbuf->db_level != new_nlevels-1 && 1839 dr->dr_dbuf->db_blkid != DMU_BONUS_BLKID && 1840 dr->dr_dbuf->db_blkid != DMU_SPILL_BLKID) { 1841 ASSERT(dr->dr_dbuf->db_level == old_nlevels-1); 1842 list_remove(&dn->dn_dirty_records[txgoff], dr); 1843 list_insert_tail(&new->dt.di.dr_children, dr); 1844 dr->dr_parent = new; 1845 } 1846 } 1847 mutex_exit(&new->dt.di.dr_mtx); 1848 mutex_exit(&dn->dn_mtx); 1849 } 1850 1851 int 1852 dnode_set_nlevels(dnode_t *dn, int nlevels, dmu_tx_t *tx) 1853 { 1854 int ret = 0; 1855 1856 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 1857 1858 if (dn->dn_nlevels == nlevels) { 1859 ret = 0; 1860 goto out; 1861 } else if (nlevels < dn->dn_nlevels) { 1862 ret = SET_ERROR(EINVAL); 1863 goto out; 1864 } 1865 1866 dnode_set_nlevels_impl(dn, nlevels, tx); 1867 1868 out: 1869 rw_exit(&dn->dn_struct_rwlock); 1870 return (ret); 1871 } 1872 1873 /* read-holding callers must not rely on the lock being continuously held */ 1874 void 1875 dnode_new_blkid(dnode_t *dn, uint64_t blkid, dmu_tx_t *tx, boolean_t have_read, 1876 boolean_t force) 1877 { 1878 int epbs, new_nlevels; 1879 uint64_t sz; 1880 1881 ASSERT(blkid != DMU_BONUS_BLKID); 1882 1883 ASSERT(have_read ? 1884 RW_READ_HELD(&dn->dn_struct_rwlock) : 1885 RW_WRITE_HELD(&dn->dn_struct_rwlock)); 1886 1887 /* 1888 * if we have a read-lock, check to see if we need to do any work 1889 * before upgrading to a write-lock. 1890 */ 1891 if (have_read) { 1892 if (blkid <= dn->dn_maxblkid) 1893 return; 1894 1895 if (!rw_tryupgrade(&dn->dn_struct_rwlock)) { 1896 rw_exit(&dn->dn_struct_rwlock); 1897 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 1898 } 1899 } 1900 1901 /* 1902 * Raw sends (indicated by the force flag) require that we take the 1903 * given blkid even if the value is lower than the current value. 1904 */ 1905 if (!force && blkid <= dn->dn_maxblkid) 1906 goto out; 1907 1908 /* 1909 * We use the (otherwise unused) top bit of dn_next_maxblkid[txgoff] 1910 * to indicate that this field is set. This allows us to set the 1911 * maxblkid to 0 on an existing object in dnode_sync(). 1912 */ 1913 dn->dn_maxblkid = blkid; 1914 dn->dn_next_maxblkid[tx->tx_txg & TXG_MASK] = 1915 blkid | DMU_NEXT_MAXBLKID_SET; 1916 1917 /* 1918 * Compute the number of levels necessary to support the new maxblkid. 1919 * Raw sends will ensure nlevels is set correctly for us. 1920 */ 1921 new_nlevels = 1; 1922 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT; 1923 for (sz = dn->dn_nblkptr; 1924 sz <= blkid && sz >= dn->dn_nblkptr; sz <<= epbs) 1925 new_nlevels++; 1926 1927 if (!force) { 1928 if (new_nlevels > dn->dn_nlevels) 1929 dnode_set_nlevels_impl(dn, new_nlevels, tx); 1930 } else { 1931 ASSERT3U(dn->dn_nlevels, >=, new_nlevels); 1932 } 1933 1934 out: 1935 if (have_read) 1936 rw_downgrade(&dn->dn_struct_rwlock); 1937 } 1938 1939 static void 1940 dnode_dirty_l1(dnode_t *dn, uint64_t l1blkid, dmu_tx_t *tx) 1941 { 1942 dmu_buf_impl_t *db = dbuf_hold_level(dn, 1, l1blkid, FTAG); 1943 if (db != NULL) { 1944 dmu_buf_will_dirty(&db->db, tx); 1945 dbuf_rele(db, FTAG); 1946 } 1947 } 1948 1949 /* 1950 * Dirty all the in-core level-1 dbufs in the range specified by start_blkid 1951 * and end_blkid. 1952 */ 1953 static void 1954 dnode_dirty_l1range(dnode_t *dn, uint64_t start_blkid, uint64_t end_blkid, 1955 dmu_tx_t *tx) 1956 { 1957 dmu_buf_impl_t db_search; 1958 dmu_buf_impl_t *db; 1959 avl_index_t where; 1960 1961 mutex_enter(&dn->dn_dbufs_mtx); 1962 1963 db_search.db_level = 1; 1964 db_search.db_blkid = start_blkid + 1; 1965 db_search.db_state = DB_SEARCH; 1966 for (;;) { 1967 1968 db = avl_find(&dn->dn_dbufs, &db_search, &where); 1969 if (db == NULL) 1970 db = avl_nearest(&dn->dn_dbufs, where, AVL_AFTER); 1971 1972 if (db == NULL || db->db_level != 1 || 1973 db->db_blkid >= end_blkid) { 1974 break; 1975 } 1976 1977 /* 1978 * Setup the next blkid we want to search for. 1979 */ 1980 db_search.db_blkid = db->db_blkid + 1; 1981 ASSERT3U(db->db_blkid, >=, start_blkid); 1982 1983 /* 1984 * If the dbuf transitions to DB_EVICTING while we're trying 1985 * to dirty it, then we will be unable to discover it in 1986 * the dbuf hash table. This will result in a call to 1987 * dbuf_create() which needs to acquire the dn_dbufs_mtx 1988 * lock. To avoid a deadlock, we drop the lock before 1989 * dirtying the level-1 dbuf. 1990 */ 1991 mutex_exit(&dn->dn_dbufs_mtx); 1992 dnode_dirty_l1(dn, db->db_blkid, tx); 1993 mutex_enter(&dn->dn_dbufs_mtx); 1994 } 1995 1996 #ifdef ZFS_DEBUG 1997 /* 1998 * Walk all the in-core level-1 dbufs and verify they have been dirtied. 1999 */ 2000 db_search.db_level = 1; 2001 db_search.db_blkid = start_blkid + 1; 2002 db_search.db_state = DB_SEARCH; 2003 db = avl_find(&dn->dn_dbufs, &db_search, &where); 2004 if (db == NULL) 2005 db = avl_nearest(&dn->dn_dbufs, where, AVL_AFTER); 2006 for (; db != NULL; db = AVL_NEXT(&dn->dn_dbufs, db)) { 2007 if (db->db_level != 1 || db->db_blkid >= end_blkid) 2008 break; 2009 ASSERT(db->db_dirtycnt > 0); 2010 } 2011 #endif 2012 mutex_exit(&dn->dn_dbufs_mtx); 2013 } 2014 2015 void 2016 dnode_free_range(dnode_t *dn, uint64_t off, uint64_t len, dmu_tx_t *tx) 2017 { 2018 dmu_buf_impl_t *db; 2019 uint64_t blkoff, blkid, nblks; 2020 int blksz, blkshift, head, tail; 2021 int trunc = FALSE; 2022 int epbs; 2023 2024 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 2025 blksz = dn->dn_datablksz; 2026 blkshift = dn->dn_datablkshift; 2027 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT; 2028 2029 if (len == DMU_OBJECT_END) { 2030 len = UINT64_MAX - off; 2031 trunc = TRUE; 2032 } 2033 2034 /* 2035 * First, block align the region to free: 2036 */ 2037 if (ISP2(blksz)) { 2038 head = P2NPHASE(off, blksz); 2039 blkoff = P2PHASE(off, blksz); 2040 if ((off >> blkshift) > dn->dn_maxblkid) 2041 goto out; 2042 } else { 2043 ASSERT(dn->dn_maxblkid == 0); 2044 if (off == 0 && len >= blksz) { 2045 /* 2046 * Freeing the whole block; fast-track this request. 2047 */ 2048 blkid = 0; 2049 nblks = 1; 2050 if (dn->dn_nlevels > 1) 2051 dnode_dirty_l1(dn, 0, tx); 2052 goto done; 2053 } else if (off >= blksz) { 2054 /* Freeing past end-of-data */ 2055 goto out; 2056 } else { 2057 /* Freeing part of the block. */ 2058 head = blksz - off; 2059 ASSERT3U(head, >, 0); 2060 } 2061 blkoff = off; 2062 } 2063 /* zero out any partial block data at the start of the range */ 2064 if (head) { 2065 ASSERT3U(blkoff + head, ==, blksz); 2066 if (len < head) 2067 head = len; 2068 if (dbuf_hold_impl(dn, 0, dbuf_whichblock(dn, 0, off), 2069 TRUE, FALSE, FTAG, &db) == 0) { 2070 caddr_t data; 2071 2072 /* don't dirty if it isn't on disk and isn't dirty */ 2073 if (db->db_last_dirty || 2074 (db->db_blkptr && !BP_IS_HOLE(db->db_blkptr))) { 2075 rw_exit(&dn->dn_struct_rwlock); 2076 dmu_buf_will_dirty(&db->db, tx); 2077 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 2078 data = db->db.db_data; 2079 bzero(data + blkoff, head); 2080 } 2081 dbuf_rele(db, FTAG); 2082 } 2083 off += head; 2084 len -= head; 2085 } 2086 2087 /* If the range was less than one block, we're done */ 2088 if (len == 0) 2089 goto out; 2090 2091 /* If the remaining range is past end of file, we're done */ 2092 if ((off >> blkshift) > dn->dn_maxblkid) 2093 goto out; 2094 2095 ASSERT(ISP2(blksz)); 2096 if (trunc) 2097 tail = 0; 2098 else 2099 tail = P2PHASE(len, blksz); 2100 2101 ASSERT0(P2PHASE(off, blksz)); 2102 /* zero out any partial block data at the end of the range */ 2103 if (tail) { 2104 if (len < tail) 2105 tail = len; 2106 if (dbuf_hold_impl(dn, 0, dbuf_whichblock(dn, 0, off+len), 2107 TRUE, FALSE, FTAG, &db) == 0) { 2108 /* don't dirty if not on disk and not dirty */ 2109 if (db->db_last_dirty || 2110 (db->db_blkptr && !BP_IS_HOLE(db->db_blkptr))) { 2111 rw_exit(&dn->dn_struct_rwlock); 2112 dmu_buf_will_dirty(&db->db, tx); 2113 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 2114 bzero(db->db.db_data, tail); 2115 } 2116 dbuf_rele(db, FTAG); 2117 } 2118 len -= tail; 2119 } 2120 2121 /* If the range did not include a full block, we are done */ 2122 if (len == 0) 2123 goto out; 2124 2125 ASSERT(IS_P2ALIGNED(off, blksz)); 2126 ASSERT(trunc || IS_P2ALIGNED(len, blksz)); 2127 blkid = off >> blkshift; 2128 nblks = len >> blkshift; 2129 if (trunc) 2130 nblks += 1; 2131 2132 /* 2133 * Dirty all the indirect blocks in this range. Note that only 2134 * the first and last indirect blocks can actually be written 2135 * (if they were partially freed) -- they must be dirtied, even if 2136 * they do not exist on disk yet. The interior blocks will 2137 * be freed by free_children(), so they will not actually be written. 2138 * Even though these interior blocks will not be written, we 2139 * dirty them for two reasons: 2140 * 2141 * - It ensures that the indirect blocks remain in memory until 2142 * syncing context. (They have already been prefetched by 2143 * dmu_tx_hold_free(), so we don't have to worry about reading 2144 * them serially here.) 2145 * 2146 * - The dirty space accounting will put pressure on the txg sync 2147 * mechanism to begin syncing, and to delay transactions if there 2148 * is a large amount of freeing. Even though these indirect 2149 * blocks will not be written, we could need to write the same 2150 * amount of space if we copy the freed BPs into deadlists. 2151 */ 2152 if (dn->dn_nlevels > 1) { 2153 uint64_t first, last; 2154 2155 first = blkid >> epbs; 2156 dnode_dirty_l1(dn, first, tx); 2157 if (trunc) 2158 last = dn->dn_maxblkid >> epbs; 2159 else 2160 last = (blkid + nblks - 1) >> epbs; 2161 if (last != first) 2162 dnode_dirty_l1(dn, last, tx); 2163 2164 dnode_dirty_l1range(dn, first, last, tx); 2165 2166 int shift = dn->dn_datablkshift + dn->dn_indblkshift - 2167 SPA_BLKPTRSHIFT; 2168 for (uint64_t i = first + 1; i < last; i++) { 2169 /* 2170 * Set i to the blockid of the next non-hole 2171 * level-1 indirect block at or after i. Note 2172 * that dnode_next_offset() operates in terms of 2173 * level-0-equivalent bytes. 2174 */ 2175 uint64_t ibyte = i << shift; 2176 int err = dnode_next_offset(dn, DNODE_FIND_HAVELOCK, 2177 &ibyte, 2, 1, 0); 2178 i = ibyte >> shift; 2179 if (i >= last) 2180 break; 2181 2182 /* 2183 * Normally we should not see an error, either 2184 * from dnode_next_offset() or dbuf_hold_level() 2185 * (except for ESRCH from dnode_next_offset). 2186 * If there is an i/o error, then when we read 2187 * this block in syncing context, it will use 2188 * ZIO_FLAG_MUSTSUCCEED, and thus hang/panic according 2189 * to the "failmode" property. dnode_next_offset() 2190 * doesn't have a flag to indicate MUSTSUCCEED. 2191 */ 2192 if (err != 0) 2193 break; 2194 2195 dnode_dirty_l1(dn, i, tx); 2196 } 2197 } 2198 2199 done: 2200 /* 2201 * Add this range to the dnode range list. 2202 * We will finish up this free operation in the syncing phase. 2203 */ 2204 mutex_enter(&dn->dn_mtx); 2205 int txgoff = tx->tx_txg & TXG_MASK; 2206 if (dn->dn_free_ranges[txgoff] == NULL) { 2207 dn->dn_free_ranges[txgoff] = range_tree_create(NULL, 2208 RANGE_SEG64, NULL, 0, 0); 2209 } 2210 range_tree_clear(dn->dn_free_ranges[txgoff], blkid, nblks); 2211 range_tree_add(dn->dn_free_ranges[txgoff], blkid, nblks); 2212 dprintf_dnode(dn, "blkid=%llu nblks=%llu txg=%llu\n", 2213 blkid, nblks, tx->tx_txg); 2214 mutex_exit(&dn->dn_mtx); 2215 2216 dbuf_free_range(dn, blkid, blkid + nblks - 1, tx); 2217 dnode_setdirty(dn, tx); 2218 out: 2219 2220 rw_exit(&dn->dn_struct_rwlock); 2221 } 2222 2223 static boolean_t 2224 dnode_spill_freed(dnode_t *dn) 2225 { 2226 int i; 2227 2228 mutex_enter(&dn->dn_mtx); 2229 for (i = 0; i < TXG_SIZE; i++) { 2230 if (dn->dn_rm_spillblk[i] == DN_KILL_SPILLBLK) 2231 break; 2232 } 2233 mutex_exit(&dn->dn_mtx); 2234 return (i < TXG_SIZE); 2235 } 2236 2237 /* return TRUE if this blkid was freed in a recent txg, or FALSE if it wasn't */ 2238 uint64_t 2239 dnode_block_freed(dnode_t *dn, uint64_t blkid) 2240 { 2241 void *dp = spa_get_dsl(dn->dn_objset->os_spa); 2242 int i; 2243 2244 if (blkid == DMU_BONUS_BLKID) 2245 return (FALSE); 2246 2247 /* 2248 * If we're in the process of opening the pool, dp will not be 2249 * set yet, but there shouldn't be anything dirty. 2250 */ 2251 if (dp == NULL) 2252 return (FALSE); 2253 2254 if (dn->dn_free_txg) 2255 return (TRUE); 2256 2257 if (blkid == DMU_SPILL_BLKID) 2258 return (dnode_spill_freed(dn)); 2259 2260 mutex_enter(&dn->dn_mtx); 2261 for (i = 0; i < TXG_SIZE; i++) { 2262 if (dn->dn_free_ranges[i] != NULL && 2263 range_tree_contains(dn->dn_free_ranges[i], blkid, 1)) 2264 break; 2265 } 2266 mutex_exit(&dn->dn_mtx); 2267 return (i < TXG_SIZE); 2268 } 2269 2270 /* call from syncing context when we actually write/free space for this dnode */ 2271 void 2272 dnode_diduse_space(dnode_t *dn, int64_t delta) 2273 { 2274 uint64_t space; 2275 dprintf_dnode(dn, "dn=%p dnp=%p used=%llu delta=%lld\n", 2276 dn, dn->dn_phys, 2277 (u_longlong_t)dn->dn_phys->dn_used, 2278 (longlong_t)delta); 2279 2280 mutex_enter(&dn->dn_mtx); 2281 space = DN_USED_BYTES(dn->dn_phys); 2282 if (delta > 0) { 2283 ASSERT3U(space + delta, >=, space); /* no overflow */ 2284 } else { 2285 ASSERT3U(space, >=, -delta); /* no underflow */ 2286 } 2287 space += delta; 2288 if (spa_version(dn->dn_objset->os_spa) < SPA_VERSION_DNODE_BYTES) { 2289 ASSERT((dn->dn_phys->dn_flags & DNODE_FLAG_USED_BYTES) == 0); 2290 ASSERT0(P2PHASE(space, 1<<DEV_BSHIFT)); 2291 dn->dn_phys->dn_used = space >> DEV_BSHIFT; 2292 } else { 2293 dn->dn_phys->dn_used = space; 2294 dn->dn_phys->dn_flags |= DNODE_FLAG_USED_BYTES; 2295 } 2296 mutex_exit(&dn->dn_mtx); 2297 } 2298 2299 /* 2300 * Scans a block at the indicated "level" looking for a hole or data, 2301 * depending on 'flags'. 2302 * 2303 * If level > 0, then we are scanning an indirect block looking at its 2304 * pointers. If level == 0, then we are looking at a block of dnodes. 2305 * 2306 * If we don't find what we are looking for in the block, we return ESRCH. 2307 * Otherwise, return with *offset pointing to the beginning (if searching 2308 * forwards) or end (if searching backwards) of the range covered by the 2309 * block pointer we matched on (or dnode). 2310 * 2311 * The basic search algorithm used below by dnode_next_offset() is to 2312 * use this function to search up the block tree (widen the search) until 2313 * we find something (i.e., we don't return ESRCH) and then search back 2314 * down the tree (narrow the search) until we reach our original search 2315 * level. 2316 */ 2317 static int 2318 dnode_next_offset_level(dnode_t *dn, int flags, uint64_t *offset, 2319 int lvl, uint64_t blkfill, uint64_t txg) 2320 { 2321 dmu_buf_impl_t *db = NULL; 2322 void *data = NULL; 2323 uint64_t epbs = dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT; 2324 uint64_t epb = 1ULL << epbs; 2325 uint64_t minfill, maxfill; 2326 boolean_t hole; 2327 int i, inc, error, span; 2328 2329 dprintf("probing object %llu offset %llx level %d of %u\n", 2330 dn->dn_object, *offset, lvl, dn->dn_phys->dn_nlevels); 2331 2332 hole = ((flags & DNODE_FIND_HOLE) != 0); 2333 inc = (flags & DNODE_FIND_BACKWARDS) ? -1 : 1; 2334 ASSERT(txg == 0 || !hole); 2335 2336 if (lvl == dn->dn_phys->dn_nlevels) { 2337 error = 0; 2338 epb = dn->dn_phys->dn_nblkptr; 2339 data = dn->dn_phys->dn_blkptr; 2340 } else { 2341 uint64_t blkid = dbuf_whichblock(dn, lvl, *offset); 2342 error = dbuf_hold_impl(dn, lvl, blkid, TRUE, FALSE, FTAG, &db); 2343 if (error) { 2344 if (error != ENOENT) 2345 return (error); 2346 if (hole) 2347 return (0); 2348 /* 2349 * This can only happen when we are searching up 2350 * the block tree for data. We don't really need to 2351 * adjust the offset, as we will just end up looking 2352 * at the pointer to this block in its parent, and its 2353 * going to be unallocated, so we will skip over it. 2354 */ 2355 return (SET_ERROR(ESRCH)); 2356 } 2357 error = dbuf_read(db, NULL, 2358 DB_RF_CANFAIL | DB_RF_HAVESTRUCT | DB_RF_NO_DECRYPT); 2359 if (error) { 2360 dbuf_rele(db, FTAG); 2361 return (error); 2362 } 2363 data = db->db.db_data; 2364 } 2365 2366 2367 if (db != NULL && txg != 0 && (db->db_blkptr == NULL || 2368 db->db_blkptr->blk_birth <= txg || 2369 BP_IS_HOLE(db->db_blkptr))) { 2370 /* 2371 * This can only happen when we are searching up the tree 2372 * and these conditions mean that we need to keep climbing. 2373 */ 2374 error = SET_ERROR(ESRCH); 2375 } else if (lvl == 0) { 2376 dnode_phys_t *dnp = data; 2377 2378 ASSERT(dn->dn_type == DMU_OT_DNODE); 2379 ASSERT(!(flags & DNODE_FIND_BACKWARDS)); 2380 2381 for (i = (*offset >> DNODE_SHIFT) & (blkfill - 1); 2382 i < blkfill; i += dnp[i].dn_extra_slots + 1) { 2383 if ((dnp[i].dn_type == DMU_OT_NONE) == hole) 2384 break; 2385 } 2386 2387 if (i == blkfill) 2388 error = SET_ERROR(ESRCH); 2389 2390 *offset = (*offset & ~(DNODE_BLOCK_SIZE - 1)) + 2391 (i << DNODE_SHIFT); 2392 } else { 2393 blkptr_t *bp = data; 2394 uint64_t start = *offset; 2395 span = (lvl - 1) * epbs + dn->dn_datablkshift; 2396 minfill = 0; 2397 maxfill = blkfill << ((lvl - 1) * epbs); 2398 2399 if (hole) 2400 maxfill--; 2401 else 2402 minfill++; 2403 2404 *offset = *offset >> span; 2405 for (i = BF64_GET(*offset, 0, epbs); 2406 i >= 0 && i < epb; i += inc) { 2407 if (BP_GET_FILL(&bp[i]) >= minfill && 2408 BP_GET_FILL(&bp[i]) <= maxfill && 2409 (hole || bp[i].blk_birth > txg)) 2410 break; 2411 if (inc > 0 || *offset > 0) 2412 *offset += inc; 2413 } 2414 *offset = *offset << span; 2415 if (inc < 0) { 2416 /* traversing backwards; position offset at the end */ 2417 ASSERT3U(*offset, <=, start); 2418 *offset = MIN(*offset + (1ULL << span) - 1, start); 2419 } else if (*offset < start) { 2420 *offset = start; 2421 } 2422 if (i < 0 || i >= epb) 2423 error = SET_ERROR(ESRCH); 2424 } 2425 2426 if (db) 2427 dbuf_rele(db, FTAG); 2428 2429 return (error); 2430 } 2431 2432 /* 2433 * Find the next hole, data, or sparse region at or after *offset. 2434 * The value 'blkfill' tells us how many items we expect to find 2435 * in an L0 data block; this value is 1 for normal objects, 2436 * DNODES_PER_BLOCK for the meta dnode, and some fraction of 2437 * DNODES_PER_BLOCK when searching for sparse regions thereof. 2438 * 2439 * Examples: 2440 * 2441 * dnode_next_offset(dn, flags, offset, 1, 1, 0); 2442 * Finds the next/previous hole/data in a file. 2443 * Used in dmu_offset_next(). 2444 * 2445 * dnode_next_offset(mdn, flags, offset, 0, DNODES_PER_BLOCK, txg); 2446 * Finds the next free/allocated dnode an objset's meta-dnode. 2447 * Only finds objects that have new contents since txg (ie. 2448 * bonus buffer changes and content removal are ignored). 2449 * Used in dmu_object_next(). 2450 * 2451 * dnode_next_offset(mdn, DNODE_FIND_HOLE, offset, 2, DNODES_PER_BLOCK >> 2, 0); 2452 * Finds the next L2 meta-dnode bp that's at most 1/4 full. 2453 * Used in dmu_object_alloc(). 2454 */ 2455 int 2456 dnode_next_offset(dnode_t *dn, int flags, uint64_t *offset, 2457 int minlvl, uint64_t blkfill, uint64_t txg) 2458 { 2459 uint64_t initial_offset = *offset; 2460 int lvl, maxlvl; 2461 int error = 0; 2462 2463 if (!(flags & DNODE_FIND_HAVELOCK)) 2464 rw_enter(&dn->dn_struct_rwlock, RW_READER); 2465 2466 if (dn->dn_phys->dn_nlevels == 0) { 2467 error = SET_ERROR(ESRCH); 2468 goto out; 2469 } 2470 2471 if (dn->dn_datablkshift == 0) { 2472 if (*offset < dn->dn_datablksz) { 2473 if (flags & DNODE_FIND_HOLE) 2474 *offset = dn->dn_datablksz; 2475 } else { 2476 error = SET_ERROR(ESRCH); 2477 } 2478 goto out; 2479 } 2480 2481 maxlvl = dn->dn_phys->dn_nlevels; 2482 2483 for (lvl = minlvl; lvl <= maxlvl; lvl++) { 2484 error = dnode_next_offset_level(dn, 2485 flags, offset, lvl, blkfill, txg); 2486 if (error != ESRCH) 2487 break; 2488 } 2489 2490 while (error == 0 && --lvl >= minlvl) { 2491 error = dnode_next_offset_level(dn, 2492 flags, offset, lvl, blkfill, txg); 2493 } 2494 2495 /* 2496 * There's always a "virtual hole" at the end of the object, even 2497 * if all BP's which physically exist are non-holes. 2498 */ 2499 if ((flags & DNODE_FIND_HOLE) && error == ESRCH && txg == 0 && 2500 minlvl == 1 && blkfill == 1 && !(flags & DNODE_FIND_BACKWARDS)) { 2501 error = 0; 2502 } 2503 2504 if (error == 0 && (flags & DNODE_FIND_BACKWARDS ? 2505 initial_offset < *offset : initial_offset > *offset)) 2506 error = SET_ERROR(ESRCH); 2507 out: 2508 if (!(flags & DNODE_FIND_HAVELOCK)) 2509 rw_exit(&dn->dn_struct_rwlock); 2510 2511 return (error); 2512 } 2513