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, 2020 by Delphix. All rights reserved. 24 * Copyright (c) 2014 Spectra Logic Corporation, All rights reserved. 25 */ 26 27 #include <sys/zfs_context.h> 28 #include <sys/dbuf.h> 29 #include <sys/dnode.h> 30 #include <sys/dmu.h> 31 #include <sys/dmu_impl.h> 32 #include <sys/dmu_tx.h> 33 #include <sys/dmu_objset.h> 34 #include <sys/dsl_dir.h> 35 #include <sys/dsl_dataset.h> 36 #include <sys/spa.h> 37 #include <sys/zio.h> 38 #include <sys/dmu_zfetch.h> 39 #include <sys/range_tree.h> 40 #include <sys/trace_zfs.h> 41 #include <sys/zfs_project.h> 42 43 dnode_stats_t dnode_stats = { 44 { "dnode_hold_dbuf_hold", KSTAT_DATA_UINT64 }, 45 { "dnode_hold_dbuf_read", KSTAT_DATA_UINT64 }, 46 { "dnode_hold_alloc_hits", KSTAT_DATA_UINT64 }, 47 { "dnode_hold_alloc_misses", KSTAT_DATA_UINT64 }, 48 { "dnode_hold_alloc_interior", KSTAT_DATA_UINT64 }, 49 { "dnode_hold_alloc_lock_retry", KSTAT_DATA_UINT64 }, 50 { "dnode_hold_alloc_lock_misses", KSTAT_DATA_UINT64 }, 51 { "dnode_hold_alloc_type_none", KSTAT_DATA_UINT64 }, 52 { "dnode_hold_free_hits", KSTAT_DATA_UINT64 }, 53 { "dnode_hold_free_misses", KSTAT_DATA_UINT64 }, 54 { "dnode_hold_free_lock_misses", KSTAT_DATA_UINT64 }, 55 { "dnode_hold_free_lock_retry", KSTAT_DATA_UINT64 }, 56 { "dnode_hold_free_overflow", KSTAT_DATA_UINT64 }, 57 { "dnode_hold_free_refcount", KSTAT_DATA_UINT64 }, 58 { "dnode_free_interior_lock_retry", KSTAT_DATA_UINT64 }, 59 { "dnode_allocate", KSTAT_DATA_UINT64 }, 60 { "dnode_reallocate", KSTAT_DATA_UINT64 }, 61 { "dnode_buf_evict", KSTAT_DATA_UINT64 }, 62 { "dnode_alloc_next_chunk", KSTAT_DATA_UINT64 }, 63 { "dnode_alloc_race", KSTAT_DATA_UINT64 }, 64 { "dnode_alloc_next_block", KSTAT_DATA_UINT64 }, 65 { "dnode_move_invalid", KSTAT_DATA_UINT64 }, 66 { "dnode_move_recheck1", KSTAT_DATA_UINT64 }, 67 { "dnode_move_recheck2", KSTAT_DATA_UINT64 }, 68 { "dnode_move_special", KSTAT_DATA_UINT64 }, 69 { "dnode_move_handle", KSTAT_DATA_UINT64 }, 70 { "dnode_move_rwlock", KSTAT_DATA_UINT64 }, 71 { "dnode_move_active", KSTAT_DATA_UINT64 }, 72 }; 73 74 static kstat_t *dnode_ksp; 75 static kmem_cache_t *dnode_cache; 76 77 static dnode_phys_t dnode_phys_zero __maybe_unused; 78 79 int zfs_default_bs = SPA_MINBLOCKSHIFT; 80 int zfs_default_ibs = DN_MAX_INDBLKSHIFT; 81 82 #ifdef _KERNEL 83 static kmem_cbrc_t dnode_move(void *, void *, size_t, void *); 84 #endif /* _KERNEL */ 85 86 static int 87 dbuf_compare(const void *x1, const void *x2) 88 { 89 const dmu_buf_impl_t *d1 = x1; 90 const dmu_buf_impl_t *d2 = x2; 91 92 int cmp = TREE_CMP(d1->db_level, d2->db_level); 93 if (likely(cmp)) 94 return (cmp); 95 96 cmp = TREE_CMP(d1->db_blkid, d2->db_blkid); 97 if (likely(cmp)) 98 return (cmp); 99 100 if (d1->db_state == DB_SEARCH) { 101 ASSERT3S(d2->db_state, !=, DB_SEARCH); 102 return (-1); 103 } else if (d2->db_state == DB_SEARCH) { 104 ASSERT3S(d1->db_state, !=, DB_SEARCH); 105 return (1); 106 } 107 108 return (TREE_PCMP(d1, d2)); 109 } 110 111 /* ARGSUSED */ 112 static int 113 dnode_cons(void *arg, void *unused, int kmflag) 114 { 115 dnode_t *dn = arg; 116 int i; 117 118 rw_init(&dn->dn_struct_rwlock, NULL, RW_NOLOCKDEP, NULL); 119 mutex_init(&dn->dn_mtx, NULL, MUTEX_DEFAULT, NULL); 120 mutex_init(&dn->dn_dbufs_mtx, NULL, MUTEX_DEFAULT, NULL); 121 cv_init(&dn->dn_notxholds, NULL, CV_DEFAULT, NULL); 122 cv_init(&dn->dn_nodnholds, NULL, CV_DEFAULT, NULL); 123 124 /* 125 * Every dbuf has a reference, and dropping a tracked reference is 126 * O(number of references), so don't track dn_holds. 127 */ 128 zfs_refcount_create_untracked(&dn->dn_holds); 129 zfs_refcount_create(&dn->dn_tx_holds); 130 list_link_init(&dn->dn_link); 131 132 bzero(&dn->dn_next_type[0], sizeof (dn->dn_next_type)); 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", sizeof (dnode_t), 235 0, dnode_cons, dnode_dest, NULL, NULL, NULL, 0); 236 kmem_cache_set_move(dnode_cache, dnode_move); 237 238 dnode_ksp = kstat_create("zfs", 0, "dnodestats", "misc", 239 KSTAT_TYPE_NAMED, sizeof (dnode_stats) / sizeof (kstat_named_t), 240 KSTAT_FLAG_VIRTUAL); 241 if (dnode_ksp != NULL) { 242 dnode_ksp->ks_data = &dnode_stats; 243 kstat_install(dnode_ksp); 244 } 245 } 246 247 void 248 dnode_fini(void) 249 { 250 if (dnode_ksp != NULL) { 251 kstat_delete(dnode_ksp); 252 dnode_ksp = NULL; 253 } 254 255 kmem_cache_destroy(dnode_cache); 256 dnode_cache = NULL; 257 } 258 259 260 #ifdef ZFS_DEBUG 261 void 262 dnode_verify(dnode_t *dn) 263 { 264 int drop_struct_lock = FALSE; 265 266 ASSERT(dn->dn_phys); 267 ASSERT(dn->dn_objset); 268 ASSERT(dn->dn_handle->dnh_dnode == dn); 269 270 ASSERT(DMU_OT_IS_VALID(dn->dn_phys->dn_type)); 271 272 if (!(zfs_flags & ZFS_DEBUG_DNODE_VERIFY)) 273 return; 274 275 if (!RW_WRITE_HELD(&dn->dn_struct_rwlock)) { 276 rw_enter(&dn->dn_struct_rwlock, RW_READER); 277 drop_struct_lock = TRUE; 278 } 279 if (dn->dn_phys->dn_type != DMU_OT_NONE || dn->dn_allocated_txg != 0) { 280 int i; 281 int max_bonuslen = DN_SLOTS_TO_BONUSLEN(dn->dn_num_slots); 282 ASSERT3U(dn->dn_indblkshift, <=, SPA_MAXBLOCKSHIFT); 283 if (dn->dn_datablkshift) { 284 ASSERT3U(dn->dn_datablkshift, >=, SPA_MINBLOCKSHIFT); 285 ASSERT3U(dn->dn_datablkshift, <=, SPA_MAXBLOCKSHIFT); 286 ASSERT3U(1<<dn->dn_datablkshift, ==, dn->dn_datablksz); 287 } 288 ASSERT3U(dn->dn_nlevels, <=, 30); 289 ASSERT(DMU_OT_IS_VALID(dn->dn_type)); 290 ASSERT3U(dn->dn_nblkptr, >=, 1); 291 ASSERT3U(dn->dn_nblkptr, <=, DN_MAX_NBLKPTR); 292 ASSERT3U(dn->dn_bonuslen, <=, max_bonuslen); 293 ASSERT3U(dn->dn_datablksz, ==, 294 dn->dn_datablkszsec << SPA_MINBLOCKSHIFT); 295 ASSERT3U(ISP2(dn->dn_datablksz), ==, dn->dn_datablkshift != 0); 296 ASSERT3U((dn->dn_nblkptr - 1) * sizeof (blkptr_t) + 297 dn->dn_bonuslen, <=, max_bonuslen); 298 for (i = 0; i < TXG_SIZE; i++) { 299 ASSERT3U(dn->dn_next_nlevels[i], <=, dn->dn_nlevels); 300 } 301 } 302 if (dn->dn_phys->dn_type != DMU_OT_NONE) 303 ASSERT3U(dn->dn_phys->dn_nlevels, <=, dn->dn_nlevels); 304 ASSERT(DMU_OBJECT_IS_SPECIAL(dn->dn_object) || dn->dn_dbuf != NULL); 305 if (dn->dn_dbuf != NULL) { 306 ASSERT3P(dn->dn_phys, ==, 307 (dnode_phys_t *)dn->dn_dbuf->db.db_data + 308 (dn->dn_object % (dn->dn_dbuf->db.db_size >> DNODE_SHIFT))); 309 } 310 if (drop_struct_lock) 311 rw_exit(&dn->dn_struct_rwlock); 312 } 313 #endif 314 315 void 316 dnode_byteswap(dnode_phys_t *dnp) 317 { 318 uint64_t *buf64 = (void*)&dnp->dn_blkptr; 319 int i; 320 321 if (dnp->dn_type == DMU_OT_NONE) { 322 bzero(dnp, sizeof (dnode_phys_t)); 323 return; 324 } 325 326 dnp->dn_datablkszsec = BSWAP_16(dnp->dn_datablkszsec); 327 dnp->dn_bonuslen = BSWAP_16(dnp->dn_bonuslen); 328 dnp->dn_extra_slots = BSWAP_8(dnp->dn_extra_slots); 329 dnp->dn_maxblkid = BSWAP_64(dnp->dn_maxblkid); 330 dnp->dn_used = BSWAP_64(dnp->dn_used); 331 332 /* 333 * dn_nblkptr is only one byte, so it's OK to read it in either 334 * byte order. We can't read dn_bouslen. 335 */ 336 ASSERT(dnp->dn_indblkshift <= SPA_MAXBLOCKSHIFT); 337 ASSERT(dnp->dn_nblkptr <= DN_MAX_NBLKPTR); 338 for (i = 0; i < dnp->dn_nblkptr * sizeof (blkptr_t)/8; i++) 339 buf64[i] = BSWAP_64(buf64[i]); 340 341 /* 342 * OK to check dn_bonuslen for zero, because it won't matter if 343 * we have the wrong byte order. This is necessary because the 344 * dnode dnode is smaller than a regular dnode. 345 */ 346 if (dnp->dn_bonuslen != 0) { 347 /* 348 * Note that the bonus length calculated here may be 349 * longer than the actual bonus buffer. This is because 350 * we always put the bonus buffer after the last block 351 * pointer (instead of packing it against the end of the 352 * dnode buffer). 353 */ 354 int off = (dnp->dn_nblkptr-1) * sizeof (blkptr_t); 355 int slots = dnp->dn_extra_slots + 1; 356 size_t len = DN_SLOTS_TO_BONUSLEN(slots) - off; 357 dmu_object_byteswap_t byteswap; 358 ASSERT(DMU_OT_IS_VALID(dnp->dn_bonustype)); 359 byteswap = DMU_OT_BYTESWAP(dnp->dn_bonustype); 360 dmu_ot_byteswap[byteswap].ob_func(dnp->dn_bonus + off, len); 361 } 362 363 /* Swap SPILL block if we have one */ 364 if (dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) 365 byteswap_uint64_array(DN_SPILL_BLKPTR(dnp), sizeof (blkptr_t)); 366 } 367 368 void 369 dnode_buf_byteswap(void *vbuf, size_t size) 370 { 371 int i = 0; 372 373 ASSERT3U(sizeof (dnode_phys_t), ==, (1<<DNODE_SHIFT)); 374 ASSERT((size & (sizeof (dnode_phys_t)-1)) == 0); 375 376 while (i < size) { 377 dnode_phys_t *dnp = (void *)(((char *)vbuf) + i); 378 dnode_byteswap(dnp); 379 380 i += DNODE_MIN_SIZE; 381 if (dnp->dn_type != DMU_OT_NONE) 382 i += dnp->dn_extra_slots * DNODE_MIN_SIZE; 383 } 384 } 385 386 void 387 dnode_setbonuslen(dnode_t *dn, int newsize, dmu_tx_t *tx) 388 { 389 ASSERT3U(zfs_refcount_count(&dn->dn_holds), >=, 1); 390 391 dnode_setdirty(dn, tx); 392 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 393 ASSERT3U(newsize, <=, DN_SLOTS_TO_BONUSLEN(dn->dn_num_slots) - 394 (dn->dn_nblkptr-1) * sizeof (blkptr_t)); 395 396 if (newsize < dn->dn_bonuslen) { 397 /* clear any data after the end of the new size */ 398 size_t diff = dn->dn_bonuslen - newsize; 399 char *data_end = ((char *)dn->dn_bonus->db.db_data) + newsize; 400 bzero(data_end, diff); 401 } 402 403 dn->dn_bonuslen = newsize; 404 if (newsize == 0) 405 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = DN_ZERO_BONUSLEN; 406 else 407 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = dn->dn_bonuslen; 408 rw_exit(&dn->dn_struct_rwlock); 409 } 410 411 void 412 dnode_setbonus_type(dnode_t *dn, dmu_object_type_t newtype, dmu_tx_t *tx) 413 { 414 ASSERT3U(zfs_refcount_count(&dn->dn_holds), >=, 1); 415 dnode_setdirty(dn, tx); 416 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 417 dn->dn_bonustype = newtype; 418 dn->dn_next_bonustype[tx->tx_txg & TXG_MASK] = dn->dn_bonustype; 419 rw_exit(&dn->dn_struct_rwlock); 420 } 421 422 void 423 dnode_rm_spill(dnode_t *dn, dmu_tx_t *tx) 424 { 425 ASSERT3U(zfs_refcount_count(&dn->dn_holds), >=, 1); 426 ASSERT(RW_WRITE_HELD(&dn->dn_struct_rwlock)); 427 dnode_setdirty(dn, tx); 428 dn->dn_rm_spillblk[tx->tx_txg & TXG_MASK] = DN_KILL_SPILLBLK; 429 dn->dn_have_spill = B_FALSE; 430 } 431 432 static void 433 dnode_setdblksz(dnode_t *dn, int size) 434 { 435 ASSERT0(P2PHASE(size, SPA_MINBLOCKSIZE)); 436 ASSERT3U(size, <=, SPA_MAXBLOCKSIZE); 437 ASSERT3U(size, >=, SPA_MINBLOCKSIZE); 438 ASSERT3U(size >> SPA_MINBLOCKSHIFT, <, 439 1<<(sizeof (dn->dn_phys->dn_datablkszsec) * 8)); 440 dn->dn_datablksz = size; 441 dn->dn_datablkszsec = size >> SPA_MINBLOCKSHIFT; 442 dn->dn_datablkshift = ISP2(size) ? highbit64(size - 1) : 0; 443 } 444 445 static dnode_t * 446 dnode_create(objset_t *os, dnode_phys_t *dnp, dmu_buf_impl_t *db, 447 uint64_t object, dnode_handle_t *dnh) 448 { 449 dnode_t *dn; 450 451 dn = kmem_cache_alloc(dnode_cache, KM_SLEEP); 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_DNODE); 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 dn->dn_dirtyctx_firstset = NULL; 548 if (dn->dn_bonus != NULL) { 549 mutex_enter(&dn->dn_bonus->db_mtx); 550 dbuf_destroy(dn->dn_bonus); 551 dn->dn_bonus = NULL; 552 } 553 dn->dn_zio = NULL; 554 555 dn->dn_have_spill = B_FALSE; 556 dn->dn_oldused = 0; 557 dn->dn_oldflags = 0; 558 dn->dn_olduid = 0; 559 dn->dn_oldgid = 0; 560 dn->dn_oldprojid = ZFS_DEFAULT_PROJID; 561 dn->dn_newuid = 0; 562 dn->dn_newgid = 0; 563 dn->dn_newprojid = ZFS_DEFAULT_PROJID; 564 dn->dn_id_flags = 0; 565 566 dmu_zfetch_fini(&dn->dn_zfetch); 567 kmem_cache_free(dnode_cache, dn); 568 arc_space_return(sizeof (dnode_t), ARC_SPACE_DNODE); 569 570 if (complete_os_eviction) 571 dmu_objset_evict_done(os); 572 } 573 574 void 575 dnode_allocate(dnode_t *dn, dmu_object_type_t ot, int blocksize, int ibs, 576 dmu_object_type_t bonustype, int bonuslen, int dn_slots, dmu_tx_t *tx) 577 { 578 int i; 579 580 ASSERT3U(dn_slots, >, 0); 581 ASSERT3U(dn_slots << DNODE_SHIFT, <=, 582 spa_maxdnodesize(dmu_objset_spa(dn->dn_objset))); 583 ASSERT3U(blocksize, <=, 584 spa_maxblocksize(dmu_objset_spa(dn->dn_objset))); 585 if (blocksize == 0) 586 blocksize = 1 << zfs_default_bs; 587 else 588 blocksize = P2ROUNDUP(blocksize, SPA_MINBLOCKSIZE); 589 590 if (ibs == 0) 591 ibs = zfs_default_ibs; 592 593 ibs = MIN(MAX(ibs, DN_MIN_INDBLKSHIFT), DN_MAX_INDBLKSHIFT); 594 595 dprintf("os=%p obj=%llu txg=%llu blocksize=%d ibs=%d dn_slots=%d\n", 596 dn->dn_objset, (u_longlong_t)dn->dn_object, 597 (u_longlong_t)tx->tx_txg, blocksize, ibs, dn_slots); 598 DNODE_STAT_BUMP(dnode_allocate); 599 600 ASSERT(dn->dn_type == DMU_OT_NONE); 601 ASSERT(bcmp(dn->dn_phys, &dnode_phys_zero, sizeof (dnode_phys_t)) == 0); 602 ASSERT(dn->dn_phys->dn_type == DMU_OT_NONE); 603 ASSERT(ot != DMU_OT_NONE); 604 ASSERT(DMU_OT_IS_VALID(ot)); 605 ASSERT((bonustype == DMU_OT_NONE && bonuslen == 0) || 606 (bonustype == DMU_OT_SA && bonuslen == 0) || 607 (bonustype != DMU_OT_NONE && bonuslen != 0)); 608 ASSERT(DMU_OT_IS_VALID(bonustype)); 609 ASSERT3U(bonuslen, <=, DN_SLOTS_TO_BONUSLEN(dn_slots)); 610 ASSERT(dn->dn_type == DMU_OT_NONE); 611 ASSERT0(dn->dn_maxblkid); 612 ASSERT0(dn->dn_allocated_txg); 613 ASSERT0(dn->dn_assigned_txg); 614 ASSERT(zfs_refcount_is_zero(&dn->dn_tx_holds)); 615 ASSERT3U(zfs_refcount_count(&dn->dn_holds), <=, 1); 616 ASSERT(avl_is_empty(&dn->dn_dbufs)); 617 618 for (i = 0; i < TXG_SIZE; i++) { 619 ASSERT0(dn->dn_next_nblkptr[i]); 620 ASSERT0(dn->dn_next_nlevels[i]); 621 ASSERT0(dn->dn_next_indblkshift[i]); 622 ASSERT0(dn->dn_next_bonuslen[i]); 623 ASSERT0(dn->dn_next_bonustype[i]); 624 ASSERT0(dn->dn_rm_spillblk[i]); 625 ASSERT0(dn->dn_next_blksz[i]); 626 ASSERT0(dn->dn_next_maxblkid[i]); 627 ASSERT(!multilist_link_active(&dn->dn_dirty_link[i])); 628 ASSERT3P(list_head(&dn->dn_dirty_records[i]), ==, NULL); 629 ASSERT3P(dn->dn_free_ranges[i], ==, NULL); 630 } 631 632 dn->dn_type = ot; 633 dnode_setdblksz(dn, blocksize); 634 dn->dn_indblkshift = ibs; 635 dn->dn_nlevels = 1; 636 dn->dn_num_slots = dn_slots; 637 if (bonustype == DMU_OT_SA) /* Maximize bonus space for SA */ 638 dn->dn_nblkptr = 1; 639 else { 640 dn->dn_nblkptr = MIN(DN_MAX_NBLKPTR, 641 1 + ((DN_SLOTS_TO_BONUSLEN(dn_slots) - bonuslen) >> 642 SPA_BLKPTRSHIFT)); 643 } 644 645 dn->dn_bonustype = bonustype; 646 dn->dn_bonuslen = bonuslen; 647 dn->dn_checksum = ZIO_CHECKSUM_INHERIT; 648 dn->dn_compress = ZIO_COMPRESS_INHERIT; 649 dn->dn_dirtyctx = 0; 650 651 dn->dn_free_txg = 0; 652 dn->dn_dirtyctx_firstset = NULL; 653 dn->dn_dirty_txg = 0; 654 655 dn->dn_allocated_txg = tx->tx_txg; 656 dn->dn_id_flags = 0; 657 658 dnode_setdirty(dn, tx); 659 dn->dn_next_indblkshift[tx->tx_txg & TXG_MASK] = ibs; 660 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = dn->dn_bonuslen; 661 dn->dn_next_bonustype[tx->tx_txg & TXG_MASK] = dn->dn_bonustype; 662 dn->dn_next_blksz[tx->tx_txg & TXG_MASK] = dn->dn_datablksz; 663 } 664 665 void 666 dnode_reallocate(dnode_t *dn, dmu_object_type_t ot, int blocksize, 667 dmu_object_type_t bonustype, int bonuslen, int dn_slots, 668 boolean_t keep_spill, dmu_tx_t *tx) 669 { 670 int nblkptr; 671 672 ASSERT3U(blocksize, >=, SPA_MINBLOCKSIZE); 673 ASSERT3U(blocksize, <=, 674 spa_maxblocksize(dmu_objset_spa(dn->dn_objset))); 675 ASSERT0(blocksize % SPA_MINBLOCKSIZE); 676 ASSERT(dn->dn_object != DMU_META_DNODE_OBJECT || dmu_tx_private_ok(tx)); 677 ASSERT(tx->tx_txg != 0); 678 ASSERT((bonustype == DMU_OT_NONE && bonuslen == 0) || 679 (bonustype != DMU_OT_NONE && bonuslen != 0) || 680 (bonustype == DMU_OT_SA && bonuslen == 0)); 681 ASSERT(DMU_OT_IS_VALID(bonustype)); 682 ASSERT3U(bonuslen, <=, 683 DN_BONUS_SIZE(spa_maxdnodesize(dmu_objset_spa(dn->dn_objset)))); 684 ASSERT3U(bonuslen, <=, DN_BONUS_SIZE(dn_slots << DNODE_SHIFT)); 685 686 dnode_free_interior_slots(dn); 687 DNODE_STAT_BUMP(dnode_reallocate); 688 689 /* clean up any unreferenced dbufs */ 690 dnode_evict_dbufs(dn); 691 692 dn->dn_id_flags = 0; 693 694 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 695 dnode_setdirty(dn, tx); 696 if (dn->dn_datablksz != blocksize) { 697 /* change blocksize */ 698 ASSERT0(dn->dn_maxblkid); 699 ASSERT(BP_IS_HOLE(&dn->dn_phys->dn_blkptr[0]) || 700 dnode_block_freed(dn, 0)); 701 702 dnode_setdblksz(dn, blocksize); 703 dn->dn_next_blksz[tx->tx_txg & TXG_MASK] = blocksize; 704 } 705 if (dn->dn_bonuslen != bonuslen) 706 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = bonuslen; 707 708 if (bonustype == DMU_OT_SA) /* Maximize bonus space for SA */ 709 nblkptr = 1; 710 else 711 nblkptr = MIN(DN_MAX_NBLKPTR, 712 1 + ((DN_SLOTS_TO_BONUSLEN(dn_slots) - bonuslen) >> 713 SPA_BLKPTRSHIFT)); 714 if (dn->dn_bonustype != bonustype) 715 dn->dn_next_bonustype[tx->tx_txg & TXG_MASK] = bonustype; 716 if (dn->dn_nblkptr != nblkptr) 717 dn->dn_next_nblkptr[tx->tx_txg & TXG_MASK] = nblkptr; 718 if (dn->dn_phys->dn_flags & DNODE_FLAG_SPILL_BLKPTR && !keep_spill) { 719 dbuf_rm_spill(dn, tx); 720 dnode_rm_spill(dn, tx); 721 } 722 723 rw_exit(&dn->dn_struct_rwlock); 724 725 /* change type */ 726 dn->dn_type = ot; 727 728 /* change bonus size and type */ 729 mutex_enter(&dn->dn_mtx); 730 dn->dn_bonustype = bonustype; 731 dn->dn_bonuslen = bonuslen; 732 dn->dn_num_slots = dn_slots; 733 dn->dn_nblkptr = nblkptr; 734 dn->dn_checksum = ZIO_CHECKSUM_INHERIT; 735 dn->dn_compress = ZIO_COMPRESS_INHERIT; 736 ASSERT3U(dn->dn_nblkptr, <=, DN_MAX_NBLKPTR); 737 738 /* fix up the bonus db_size */ 739 if (dn->dn_bonus) { 740 dn->dn_bonus->db.db_size = 741 DN_SLOTS_TO_BONUSLEN(dn->dn_num_slots) - 742 (dn->dn_nblkptr-1) * sizeof (blkptr_t); 743 ASSERT(dn->dn_bonuslen <= dn->dn_bonus->db.db_size); 744 } 745 746 dn->dn_allocated_txg = tx->tx_txg; 747 mutex_exit(&dn->dn_mtx); 748 } 749 750 #ifdef _KERNEL 751 static void 752 dnode_move_impl(dnode_t *odn, dnode_t *ndn) 753 { 754 int i; 755 756 ASSERT(!RW_LOCK_HELD(&odn->dn_struct_rwlock)); 757 ASSERT(MUTEX_NOT_HELD(&odn->dn_mtx)); 758 ASSERT(MUTEX_NOT_HELD(&odn->dn_dbufs_mtx)); 759 760 /* Copy fields. */ 761 ndn->dn_objset = odn->dn_objset; 762 ndn->dn_object = odn->dn_object; 763 ndn->dn_dbuf = odn->dn_dbuf; 764 ndn->dn_handle = odn->dn_handle; 765 ndn->dn_phys = odn->dn_phys; 766 ndn->dn_type = odn->dn_type; 767 ndn->dn_bonuslen = odn->dn_bonuslen; 768 ndn->dn_bonustype = odn->dn_bonustype; 769 ndn->dn_nblkptr = odn->dn_nblkptr; 770 ndn->dn_checksum = odn->dn_checksum; 771 ndn->dn_compress = odn->dn_compress; 772 ndn->dn_nlevels = odn->dn_nlevels; 773 ndn->dn_indblkshift = odn->dn_indblkshift; 774 ndn->dn_datablkshift = odn->dn_datablkshift; 775 ndn->dn_datablkszsec = odn->dn_datablkszsec; 776 ndn->dn_datablksz = odn->dn_datablksz; 777 ndn->dn_maxblkid = odn->dn_maxblkid; 778 ndn->dn_num_slots = odn->dn_num_slots; 779 bcopy(&odn->dn_next_type[0], &ndn->dn_next_type[0], 780 sizeof (odn->dn_next_type)); 781 bcopy(&odn->dn_next_nblkptr[0], &ndn->dn_next_nblkptr[0], 782 sizeof (odn->dn_next_nblkptr)); 783 bcopy(&odn->dn_next_nlevels[0], &ndn->dn_next_nlevels[0], 784 sizeof (odn->dn_next_nlevels)); 785 bcopy(&odn->dn_next_indblkshift[0], &ndn->dn_next_indblkshift[0], 786 sizeof (odn->dn_next_indblkshift)); 787 bcopy(&odn->dn_next_bonustype[0], &ndn->dn_next_bonustype[0], 788 sizeof (odn->dn_next_bonustype)); 789 bcopy(&odn->dn_rm_spillblk[0], &ndn->dn_rm_spillblk[0], 790 sizeof (odn->dn_rm_spillblk)); 791 bcopy(&odn->dn_next_bonuslen[0], &ndn->dn_next_bonuslen[0], 792 sizeof (odn->dn_next_bonuslen)); 793 bcopy(&odn->dn_next_blksz[0], &ndn->dn_next_blksz[0], 794 sizeof (odn->dn_next_blksz)); 795 bcopy(&odn->dn_next_maxblkid[0], &ndn->dn_next_maxblkid[0], 796 sizeof (odn->dn_next_maxblkid)); 797 for (i = 0; i < TXG_SIZE; i++) { 798 list_move_tail(&ndn->dn_dirty_records[i], 799 &odn->dn_dirty_records[i]); 800 } 801 bcopy(&odn->dn_free_ranges[0], &ndn->dn_free_ranges[0], 802 sizeof (odn->dn_free_ranges)); 803 ndn->dn_allocated_txg = odn->dn_allocated_txg; 804 ndn->dn_free_txg = odn->dn_free_txg; 805 ndn->dn_assigned_txg = odn->dn_assigned_txg; 806 ndn->dn_dirty_txg = odn->dn_dirty_txg; 807 ndn->dn_dirtyctx = odn->dn_dirtyctx; 808 ndn->dn_dirtyctx_firstset = odn->dn_dirtyctx_firstset; 809 ASSERT(zfs_refcount_count(&odn->dn_tx_holds) == 0); 810 zfs_refcount_transfer(&ndn->dn_holds, &odn->dn_holds); 811 ASSERT(avl_is_empty(&ndn->dn_dbufs)); 812 avl_swap(&ndn->dn_dbufs, &odn->dn_dbufs); 813 ndn->dn_dbufs_count = odn->dn_dbufs_count; 814 ndn->dn_bonus = odn->dn_bonus; 815 ndn->dn_have_spill = odn->dn_have_spill; 816 ndn->dn_zio = odn->dn_zio; 817 ndn->dn_oldused = odn->dn_oldused; 818 ndn->dn_oldflags = odn->dn_oldflags; 819 ndn->dn_olduid = odn->dn_olduid; 820 ndn->dn_oldgid = odn->dn_oldgid; 821 ndn->dn_oldprojid = odn->dn_oldprojid; 822 ndn->dn_newuid = odn->dn_newuid; 823 ndn->dn_newgid = odn->dn_newgid; 824 ndn->dn_newprojid = odn->dn_newprojid; 825 ndn->dn_id_flags = odn->dn_id_flags; 826 dmu_zfetch_init(&ndn->dn_zfetch, ndn); 827 828 /* 829 * Update back pointers. Updating the handle fixes the back pointer of 830 * every descendant dbuf as well as the bonus dbuf. 831 */ 832 ASSERT(ndn->dn_handle->dnh_dnode == odn); 833 ndn->dn_handle->dnh_dnode = ndn; 834 835 /* 836 * Invalidate the original dnode by clearing all of its back pointers. 837 */ 838 odn->dn_dbuf = NULL; 839 odn->dn_handle = NULL; 840 avl_create(&odn->dn_dbufs, dbuf_compare, sizeof (dmu_buf_impl_t), 841 offsetof(dmu_buf_impl_t, db_link)); 842 odn->dn_dbufs_count = 0; 843 odn->dn_bonus = NULL; 844 dmu_zfetch_fini(&odn->dn_zfetch); 845 846 /* 847 * Set the low bit of the objset pointer to ensure that dnode_move() 848 * recognizes the dnode as invalid in any subsequent callback. 849 */ 850 POINTER_INVALIDATE(&odn->dn_objset); 851 852 /* 853 * Satisfy the destructor. 854 */ 855 for (i = 0; i < TXG_SIZE; i++) { 856 list_create(&odn->dn_dirty_records[i], 857 sizeof (dbuf_dirty_record_t), 858 offsetof(dbuf_dirty_record_t, dr_dirty_node)); 859 odn->dn_free_ranges[i] = NULL; 860 odn->dn_next_nlevels[i] = 0; 861 odn->dn_next_indblkshift[i] = 0; 862 odn->dn_next_bonustype[i] = 0; 863 odn->dn_rm_spillblk[i] = 0; 864 odn->dn_next_bonuslen[i] = 0; 865 odn->dn_next_blksz[i] = 0; 866 } 867 odn->dn_allocated_txg = 0; 868 odn->dn_free_txg = 0; 869 odn->dn_assigned_txg = 0; 870 odn->dn_dirty_txg = 0; 871 odn->dn_dirtyctx = 0; 872 odn->dn_dirtyctx_firstset = NULL; 873 odn->dn_have_spill = B_FALSE; 874 odn->dn_zio = NULL; 875 odn->dn_oldused = 0; 876 odn->dn_oldflags = 0; 877 odn->dn_olduid = 0; 878 odn->dn_oldgid = 0; 879 odn->dn_oldprojid = ZFS_DEFAULT_PROJID; 880 odn->dn_newuid = 0; 881 odn->dn_newgid = 0; 882 odn->dn_newprojid = ZFS_DEFAULT_PROJID; 883 odn->dn_id_flags = 0; 884 885 /* 886 * Mark the dnode. 887 */ 888 ndn->dn_moved = 1; 889 odn->dn_moved = (uint8_t)-1; 890 } 891 892 /*ARGSUSED*/ 893 static kmem_cbrc_t 894 dnode_move(void *buf, void *newbuf, size_t size, void *arg) 895 { 896 dnode_t *odn = buf, *ndn = newbuf; 897 objset_t *os; 898 int64_t refcount; 899 uint32_t dbufs; 900 901 /* 902 * The dnode is on the objset's list of known dnodes if the objset 903 * pointer is valid. We set the low bit of the objset pointer when 904 * freeing the dnode to invalidate it, and the memory patterns written 905 * by kmem (baddcafe and deadbeef) set at least one of the two low bits. 906 * A newly created dnode sets the objset pointer last of all to indicate 907 * that the dnode is known and in a valid state to be moved by this 908 * function. 909 */ 910 os = odn->dn_objset; 911 if (!POINTER_IS_VALID(os)) { 912 DNODE_STAT_BUMP(dnode_move_invalid); 913 return (KMEM_CBRC_DONT_KNOW); 914 } 915 916 /* 917 * Ensure that the objset does not go away during the move. 918 */ 919 rw_enter(&os_lock, RW_WRITER); 920 if (os != odn->dn_objset) { 921 rw_exit(&os_lock); 922 DNODE_STAT_BUMP(dnode_move_recheck1); 923 return (KMEM_CBRC_DONT_KNOW); 924 } 925 926 /* 927 * If the dnode is still valid, then so is the objset. We know that no 928 * valid objset can be freed while we hold os_lock, so we can safely 929 * ensure that the objset remains in use. 930 */ 931 mutex_enter(&os->os_lock); 932 933 /* 934 * Recheck the objset pointer in case the dnode was removed just before 935 * acquiring the lock. 936 */ 937 if (os != odn->dn_objset) { 938 mutex_exit(&os->os_lock); 939 rw_exit(&os_lock); 940 DNODE_STAT_BUMP(dnode_move_recheck2); 941 return (KMEM_CBRC_DONT_KNOW); 942 } 943 944 /* 945 * At this point we know that as long as we hold os->os_lock, the dnode 946 * cannot be freed and fields within the dnode can be safely accessed. 947 * The objset listing this dnode cannot go away as long as this dnode is 948 * on its list. 949 */ 950 rw_exit(&os_lock); 951 if (DMU_OBJECT_IS_SPECIAL(odn->dn_object)) { 952 mutex_exit(&os->os_lock); 953 DNODE_STAT_BUMP(dnode_move_special); 954 return (KMEM_CBRC_NO); 955 } 956 ASSERT(odn->dn_dbuf != NULL); /* only "special" dnodes have no parent */ 957 958 /* 959 * Lock the dnode handle to prevent the dnode from obtaining any new 960 * holds. This also prevents the descendant dbufs and the bonus dbuf 961 * from accessing the dnode, so that we can discount their holds. The 962 * handle is safe to access because we know that while the dnode cannot 963 * go away, neither can its handle. Once we hold dnh_zrlock, we can 964 * safely move any dnode referenced only by dbufs. 965 */ 966 if (!zrl_tryenter(&odn->dn_handle->dnh_zrlock)) { 967 mutex_exit(&os->os_lock); 968 DNODE_STAT_BUMP(dnode_move_handle); 969 return (KMEM_CBRC_LATER); 970 } 971 972 /* 973 * Ensure a consistent view of the dnode's holds and the dnode's dbufs. 974 * We need to guarantee that there is a hold for every dbuf in order to 975 * determine whether the dnode is actively referenced. Falsely matching 976 * a dbuf to an active hold would lead to an unsafe move. It's possible 977 * that a thread already having an active dnode hold is about to add a 978 * dbuf, and we can't compare hold and dbuf counts while the add is in 979 * progress. 980 */ 981 if (!rw_tryenter(&odn->dn_struct_rwlock, RW_WRITER)) { 982 zrl_exit(&odn->dn_handle->dnh_zrlock); 983 mutex_exit(&os->os_lock); 984 DNODE_STAT_BUMP(dnode_move_rwlock); 985 return (KMEM_CBRC_LATER); 986 } 987 988 /* 989 * A dbuf may be removed (evicted) without an active dnode hold. In that 990 * case, the dbuf count is decremented under the handle lock before the 991 * dbuf's hold is released. This order ensures that if we count the hold 992 * after the dbuf is removed but before its hold is released, we will 993 * treat the unmatched hold as active and exit safely. If we count the 994 * hold before the dbuf is removed, the hold is discounted, and the 995 * removal is blocked until the move completes. 996 */ 997 refcount = zfs_refcount_count(&odn->dn_holds); 998 ASSERT(refcount >= 0); 999 dbufs = DN_DBUFS_COUNT(odn); 1000 1001 /* We can't have more dbufs than dnode holds. */ 1002 ASSERT3U(dbufs, <=, refcount); 1003 DTRACE_PROBE3(dnode__move, dnode_t *, odn, int64_t, refcount, 1004 uint32_t, dbufs); 1005 1006 if (refcount > dbufs) { 1007 rw_exit(&odn->dn_struct_rwlock); 1008 zrl_exit(&odn->dn_handle->dnh_zrlock); 1009 mutex_exit(&os->os_lock); 1010 DNODE_STAT_BUMP(dnode_move_active); 1011 return (KMEM_CBRC_LATER); 1012 } 1013 1014 rw_exit(&odn->dn_struct_rwlock); 1015 1016 /* 1017 * At this point we know that anyone with a hold on the dnode is not 1018 * actively referencing it. The dnode is known and in a valid state to 1019 * move. We're holding the locks needed to execute the critical section. 1020 */ 1021 dnode_move_impl(odn, ndn); 1022 1023 list_link_replace(&odn->dn_link, &ndn->dn_link); 1024 /* If the dnode was safe to move, the refcount cannot have changed. */ 1025 ASSERT(refcount == zfs_refcount_count(&ndn->dn_holds)); 1026 ASSERT(dbufs == DN_DBUFS_COUNT(ndn)); 1027 zrl_exit(&ndn->dn_handle->dnh_zrlock); /* handle has moved */ 1028 mutex_exit(&os->os_lock); 1029 1030 return (KMEM_CBRC_YES); 1031 } 1032 #endif /* _KERNEL */ 1033 1034 static void 1035 dnode_slots_hold(dnode_children_t *children, int idx, int slots) 1036 { 1037 ASSERT3S(idx + slots, <=, DNODES_PER_BLOCK); 1038 1039 for (int i = idx; i < idx + slots; i++) { 1040 dnode_handle_t *dnh = &children->dnc_children[i]; 1041 zrl_add(&dnh->dnh_zrlock); 1042 } 1043 } 1044 1045 static void 1046 dnode_slots_rele(dnode_children_t *children, int idx, int slots) 1047 { 1048 ASSERT3S(idx + slots, <=, DNODES_PER_BLOCK); 1049 1050 for (int i = idx; i < idx + slots; i++) { 1051 dnode_handle_t *dnh = &children->dnc_children[i]; 1052 1053 if (zrl_is_locked(&dnh->dnh_zrlock)) 1054 zrl_exit(&dnh->dnh_zrlock); 1055 else 1056 zrl_remove(&dnh->dnh_zrlock); 1057 } 1058 } 1059 1060 static int 1061 dnode_slots_tryenter(dnode_children_t *children, int idx, int slots) 1062 { 1063 ASSERT3S(idx + slots, <=, DNODES_PER_BLOCK); 1064 1065 for (int i = idx; i < idx + slots; i++) { 1066 dnode_handle_t *dnh = &children->dnc_children[i]; 1067 1068 if (!zrl_tryenter(&dnh->dnh_zrlock)) { 1069 for (int j = idx; j < i; j++) { 1070 dnh = &children->dnc_children[j]; 1071 zrl_exit(&dnh->dnh_zrlock); 1072 } 1073 1074 return (0); 1075 } 1076 } 1077 1078 return (1); 1079 } 1080 1081 static void 1082 dnode_set_slots(dnode_children_t *children, int idx, int slots, void *ptr) 1083 { 1084 ASSERT3S(idx + slots, <=, DNODES_PER_BLOCK); 1085 1086 for (int i = idx; i < idx + slots; i++) { 1087 dnode_handle_t *dnh = &children->dnc_children[i]; 1088 dnh->dnh_dnode = ptr; 1089 } 1090 } 1091 1092 static boolean_t 1093 dnode_check_slots_free(dnode_children_t *children, int idx, int slots) 1094 { 1095 ASSERT3S(idx + slots, <=, DNODES_PER_BLOCK); 1096 1097 /* 1098 * If all dnode slots are either already free or 1099 * evictable return B_TRUE. 1100 */ 1101 for (int i = idx; i < idx + slots; i++) { 1102 dnode_handle_t *dnh = &children->dnc_children[i]; 1103 dnode_t *dn = dnh->dnh_dnode; 1104 1105 if (dn == DN_SLOT_FREE) { 1106 continue; 1107 } else if (DN_SLOT_IS_PTR(dn)) { 1108 mutex_enter(&dn->dn_mtx); 1109 boolean_t can_free = (dn->dn_type == DMU_OT_NONE && 1110 zfs_refcount_is_zero(&dn->dn_holds) && 1111 !DNODE_IS_DIRTY(dn)); 1112 mutex_exit(&dn->dn_mtx); 1113 1114 if (!can_free) 1115 return (B_FALSE); 1116 else 1117 continue; 1118 } else { 1119 return (B_FALSE); 1120 } 1121 } 1122 1123 return (B_TRUE); 1124 } 1125 1126 static void 1127 dnode_reclaim_slots(dnode_children_t *children, int idx, int slots) 1128 { 1129 ASSERT3S(idx + slots, <=, DNODES_PER_BLOCK); 1130 1131 for (int i = idx; i < idx + slots; i++) { 1132 dnode_handle_t *dnh = &children->dnc_children[i]; 1133 1134 ASSERT(zrl_is_locked(&dnh->dnh_zrlock)); 1135 1136 if (DN_SLOT_IS_PTR(dnh->dnh_dnode)) { 1137 ASSERT3S(dnh->dnh_dnode->dn_type, ==, DMU_OT_NONE); 1138 dnode_destroy(dnh->dnh_dnode); 1139 dnh->dnh_dnode = DN_SLOT_FREE; 1140 } 1141 } 1142 } 1143 1144 void 1145 dnode_free_interior_slots(dnode_t *dn) 1146 { 1147 dnode_children_t *children = dmu_buf_get_user(&dn->dn_dbuf->db); 1148 int epb = dn->dn_dbuf->db.db_size >> DNODE_SHIFT; 1149 int idx = (dn->dn_object & (epb - 1)) + 1; 1150 int slots = dn->dn_num_slots - 1; 1151 1152 if (slots == 0) 1153 return; 1154 1155 ASSERT3S(idx + slots, <=, DNODES_PER_BLOCK); 1156 1157 while (!dnode_slots_tryenter(children, idx, slots)) { 1158 DNODE_STAT_BUMP(dnode_free_interior_lock_retry); 1159 cond_resched(); 1160 } 1161 1162 dnode_set_slots(children, idx, slots, DN_SLOT_FREE); 1163 dnode_slots_rele(children, idx, slots); 1164 } 1165 1166 void 1167 dnode_special_close(dnode_handle_t *dnh) 1168 { 1169 dnode_t *dn = dnh->dnh_dnode; 1170 1171 /* 1172 * Ensure dnode_rele_and_unlock() has released dn_mtx, after final 1173 * zfs_refcount_remove() 1174 */ 1175 mutex_enter(&dn->dn_mtx); 1176 if (zfs_refcount_count(&dn->dn_holds) > 0) 1177 cv_wait(&dn->dn_nodnholds, &dn->dn_mtx); 1178 mutex_exit(&dn->dn_mtx); 1179 ASSERT3U(zfs_refcount_count(&dn->dn_holds), ==, 0); 1180 1181 ASSERT(dn->dn_dbuf == NULL || 1182 dmu_buf_get_user(&dn->dn_dbuf->db) == NULL); 1183 zrl_add(&dnh->dnh_zrlock); 1184 dnode_destroy(dn); /* implicit zrl_remove() */ 1185 zrl_destroy(&dnh->dnh_zrlock); 1186 dnh->dnh_dnode = NULL; 1187 } 1188 1189 void 1190 dnode_special_open(objset_t *os, dnode_phys_t *dnp, uint64_t object, 1191 dnode_handle_t *dnh) 1192 { 1193 dnode_t *dn; 1194 1195 zrl_init(&dnh->dnh_zrlock); 1196 VERIFY3U(1, ==, zrl_tryenter(&dnh->dnh_zrlock)); 1197 1198 dn = dnode_create(os, dnp, NULL, object, dnh); 1199 DNODE_VERIFY(dn); 1200 1201 zrl_exit(&dnh->dnh_zrlock); 1202 } 1203 1204 static void 1205 dnode_buf_evict_async(void *dbu) 1206 { 1207 dnode_children_t *dnc = dbu; 1208 1209 DNODE_STAT_BUMP(dnode_buf_evict); 1210 1211 for (int i = 0; i < dnc->dnc_count; i++) { 1212 dnode_handle_t *dnh = &dnc->dnc_children[i]; 1213 dnode_t *dn; 1214 1215 /* 1216 * The dnode handle lock guards against the dnode moving to 1217 * another valid address, so there is no need here to guard 1218 * against changes to or from NULL. 1219 */ 1220 if (!DN_SLOT_IS_PTR(dnh->dnh_dnode)) { 1221 zrl_destroy(&dnh->dnh_zrlock); 1222 dnh->dnh_dnode = DN_SLOT_UNINIT; 1223 continue; 1224 } 1225 1226 zrl_add(&dnh->dnh_zrlock); 1227 dn = dnh->dnh_dnode; 1228 /* 1229 * If there are holds on this dnode, then there should 1230 * be holds on the dnode's containing dbuf as well; thus 1231 * it wouldn't be eligible for eviction and this function 1232 * would not have been called. 1233 */ 1234 ASSERT(zfs_refcount_is_zero(&dn->dn_holds)); 1235 ASSERT(zfs_refcount_is_zero(&dn->dn_tx_holds)); 1236 1237 dnode_destroy(dn); /* implicit zrl_remove() for first slot */ 1238 zrl_destroy(&dnh->dnh_zrlock); 1239 dnh->dnh_dnode = DN_SLOT_UNINIT; 1240 } 1241 kmem_free(dnc, sizeof (dnode_children_t) + 1242 dnc->dnc_count * sizeof (dnode_handle_t)); 1243 } 1244 1245 /* 1246 * When the DNODE_MUST_BE_FREE flag is set, the "slots" parameter is used 1247 * to ensure the hole at the specified object offset is large enough to 1248 * hold the dnode being created. The slots parameter is also used to ensure 1249 * a dnode does not span multiple dnode blocks. In both of these cases, if 1250 * a failure occurs, ENOSPC is returned. Keep in mind, these failure cases 1251 * are only possible when using DNODE_MUST_BE_FREE. 1252 * 1253 * If the DNODE_MUST_BE_ALLOCATED flag is set, "slots" must be 0. 1254 * dnode_hold_impl() will check if the requested dnode is already consumed 1255 * as an extra dnode slot by an large dnode, in which case it returns 1256 * ENOENT. 1257 * 1258 * If the DNODE_DRY_RUN flag is set, we don't actually hold the dnode, just 1259 * return whether the hold would succeed or not. tag and dnp should set to 1260 * NULL in this case. 1261 * 1262 * errors: 1263 * EINVAL - Invalid object number or flags. 1264 * ENOSPC - Hole too small to fulfill "slots" request (DNODE_MUST_BE_FREE) 1265 * EEXIST - Refers to an allocated dnode (DNODE_MUST_BE_FREE) 1266 * - Refers to a freeing dnode (DNODE_MUST_BE_FREE) 1267 * - Refers to an interior dnode slot (DNODE_MUST_BE_ALLOCATED) 1268 * ENOENT - The requested dnode is not allocated (DNODE_MUST_BE_ALLOCATED) 1269 * - The requested dnode is being freed (DNODE_MUST_BE_ALLOCATED) 1270 * EIO - I/O error when reading the meta dnode dbuf. 1271 * 1272 * succeeds even for free dnodes. 1273 */ 1274 int 1275 dnode_hold_impl(objset_t *os, uint64_t object, int flag, int slots, 1276 void *tag, dnode_t **dnp) 1277 { 1278 int epb, idx, err; 1279 int drop_struct_lock = FALSE; 1280 int type; 1281 uint64_t blk; 1282 dnode_t *mdn, *dn; 1283 dmu_buf_impl_t *db; 1284 dnode_children_t *dnc; 1285 dnode_phys_t *dn_block; 1286 dnode_handle_t *dnh; 1287 1288 ASSERT(!(flag & DNODE_MUST_BE_ALLOCATED) || (slots == 0)); 1289 ASSERT(!(flag & DNODE_MUST_BE_FREE) || (slots > 0)); 1290 IMPLY(flag & DNODE_DRY_RUN, (tag == NULL) && (dnp == NULL)); 1291 1292 /* 1293 * If you are holding the spa config lock as writer, you shouldn't 1294 * be asking the DMU to do *anything* unless it's the root pool 1295 * which may require us to read from the root filesystem while 1296 * holding some (not all) of the locks as writer. 1297 */ 1298 ASSERT(spa_config_held(os->os_spa, SCL_ALL, RW_WRITER) == 0 || 1299 (spa_is_root(os->os_spa) && 1300 spa_config_held(os->os_spa, SCL_STATE, RW_WRITER))); 1301 1302 ASSERT((flag & DNODE_MUST_BE_ALLOCATED) || (flag & DNODE_MUST_BE_FREE)); 1303 1304 if (object == DMU_USERUSED_OBJECT || object == DMU_GROUPUSED_OBJECT || 1305 object == DMU_PROJECTUSED_OBJECT) { 1306 if (object == DMU_USERUSED_OBJECT) 1307 dn = DMU_USERUSED_DNODE(os); 1308 else if (object == DMU_GROUPUSED_OBJECT) 1309 dn = DMU_GROUPUSED_DNODE(os); 1310 else 1311 dn = DMU_PROJECTUSED_DNODE(os); 1312 if (dn == NULL) 1313 return (SET_ERROR(ENOENT)); 1314 type = dn->dn_type; 1315 if ((flag & DNODE_MUST_BE_ALLOCATED) && type == DMU_OT_NONE) 1316 return (SET_ERROR(ENOENT)); 1317 if ((flag & DNODE_MUST_BE_FREE) && type != DMU_OT_NONE) 1318 return (SET_ERROR(EEXIST)); 1319 DNODE_VERIFY(dn); 1320 /* Don't actually hold if dry run, just return 0 */ 1321 if (!(flag & DNODE_DRY_RUN)) { 1322 (void) zfs_refcount_add(&dn->dn_holds, tag); 1323 *dnp = dn; 1324 } 1325 return (0); 1326 } 1327 1328 if (object == 0 || object >= DN_MAX_OBJECT) 1329 return (SET_ERROR(EINVAL)); 1330 1331 mdn = DMU_META_DNODE(os); 1332 ASSERT(mdn->dn_object == DMU_META_DNODE_OBJECT); 1333 1334 DNODE_VERIFY(mdn); 1335 1336 if (!RW_WRITE_HELD(&mdn->dn_struct_rwlock)) { 1337 rw_enter(&mdn->dn_struct_rwlock, RW_READER); 1338 drop_struct_lock = TRUE; 1339 } 1340 1341 blk = dbuf_whichblock(mdn, 0, object * sizeof (dnode_phys_t)); 1342 db = dbuf_hold(mdn, blk, FTAG); 1343 if (drop_struct_lock) 1344 rw_exit(&mdn->dn_struct_rwlock); 1345 if (db == NULL) { 1346 DNODE_STAT_BUMP(dnode_hold_dbuf_hold); 1347 return (SET_ERROR(EIO)); 1348 } 1349 1350 /* 1351 * We do not need to decrypt to read the dnode so it doesn't matter 1352 * if we get the encrypted or decrypted version. 1353 */ 1354 err = dbuf_read(db, NULL, DB_RF_CANFAIL | 1355 DB_RF_NO_DECRYPT | DB_RF_NOPREFETCH); 1356 if (err) { 1357 DNODE_STAT_BUMP(dnode_hold_dbuf_read); 1358 dbuf_rele(db, FTAG); 1359 return (err); 1360 } 1361 1362 ASSERT3U(db->db.db_size, >=, 1<<DNODE_SHIFT); 1363 epb = db->db.db_size >> DNODE_SHIFT; 1364 1365 idx = object & (epb - 1); 1366 dn_block = (dnode_phys_t *)db->db.db_data; 1367 1368 ASSERT(DB_DNODE(db)->dn_type == DMU_OT_DNODE); 1369 dnc = dmu_buf_get_user(&db->db); 1370 dnh = NULL; 1371 if (dnc == NULL) { 1372 dnode_children_t *winner; 1373 int skip = 0; 1374 1375 dnc = kmem_zalloc(sizeof (dnode_children_t) + 1376 epb * sizeof (dnode_handle_t), KM_SLEEP); 1377 dnc->dnc_count = epb; 1378 dnh = &dnc->dnc_children[0]; 1379 1380 /* Initialize dnode slot status from dnode_phys_t */ 1381 for (int i = 0; i < epb; i++) { 1382 zrl_init(&dnh[i].dnh_zrlock); 1383 1384 if (skip) { 1385 skip--; 1386 continue; 1387 } 1388 1389 if (dn_block[i].dn_type != DMU_OT_NONE) { 1390 int interior = dn_block[i].dn_extra_slots; 1391 1392 dnode_set_slots(dnc, i, 1, DN_SLOT_ALLOCATED); 1393 dnode_set_slots(dnc, i + 1, interior, 1394 DN_SLOT_INTERIOR); 1395 skip = interior; 1396 } else { 1397 dnh[i].dnh_dnode = DN_SLOT_FREE; 1398 skip = 0; 1399 } 1400 } 1401 1402 dmu_buf_init_user(&dnc->dnc_dbu, NULL, 1403 dnode_buf_evict_async, NULL); 1404 winner = dmu_buf_set_user(&db->db, &dnc->dnc_dbu); 1405 if (winner != NULL) { 1406 1407 for (int i = 0; i < epb; i++) 1408 zrl_destroy(&dnh[i].dnh_zrlock); 1409 1410 kmem_free(dnc, sizeof (dnode_children_t) + 1411 epb * sizeof (dnode_handle_t)); 1412 dnc = winner; 1413 } 1414 } 1415 1416 ASSERT(dnc->dnc_count == epb); 1417 1418 if (flag & DNODE_MUST_BE_ALLOCATED) { 1419 slots = 1; 1420 1421 dnode_slots_hold(dnc, idx, slots); 1422 dnh = &dnc->dnc_children[idx]; 1423 1424 if (DN_SLOT_IS_PTR(dnh->dnh_dnode)) { 1425 dn = dnh->dnh_dnode; 1426 } else if (dnh->dnh_dnode == DN_SLOT_INTERIOR) { 1427 DNODE_STAT_BUMP(dnode_hold_alloc_interior); 1428 dnode_slots_rele(dnc, idx, slots); 1429 dbuf_rele(db, FTAG); 1430 return (SET_ERROR(EEXIST)); 1431 } else if (dnh->dnh_dnode != DN_SLOT_ALLOCATED) { 1432 DNODE_STAT_BUMP(dnode_hold_alloc_misses); 1433 dnode_slots_rele(dnc, idx, slots); 1434 dbuf_rele(db, FTAG); 1435 return (SET_ERROR(ENOENT)); 1436 } else { 1437 dnode_slots_rele(dnc, idx, slots); 1438 while (!dnode_slots_tryenter(dnc, idx, slots)) { 1439 DNODE_STAT_BUMP(dnode_hold_alloc_lock_retry); 1440 cond_resched(); 1441 } 1442 1443 /* 1444 * Someone else won the race and called dnode_create() 1445 * after we checked DN_SLOT_IS_PTR() above but before 1446 * we acquired the lock. 1447 */ 1448 if (DN_SLOT_IS_PTR(dnh->dnh_dnode)) { 1449 DNODE_STAT_BUMP(dnode_hold_alloc_lock_misses); 1450 dn = dnh->dnh_dnode; 1451 } else { 1452 dn = dnode_create(os, dn_block + idx, db, 1453 object, dnh); 1454 } 1455 } 1456 1457 mutex_enter(&dn->dn_mtx); 1458 if (dn->dn_type == DMU_OT_NONE || dn->dn_free_txg != 0) { 1459 DNODE_STAT_BUMP(dnode_hold_alloc_type_none); 1460 mutex_exit(&dn->dn_mtx); 1461 dnode_slots_rele(dnc, idx, slots); 1462 dbuf_rele(db, FTAG); 1463 return (SET_ERROR(ENOENT)); 1464 } 1465 1466 /* Don't actually hold if dry run, just return 0 */ 1467 if (flag & DNODE_DRY_RUN) { 1468 mutex_exit(&dn->dn_mtx); 1469 dnode_slots_rele(dnc, idx, slots); 1470 dbuf_rele(db, FTAG); 1471 return (0); 1472 } 1473 1474 DNODE_STAT_BUMP(dnode_hold_alloc_hits); 1475 } else if (flag & DNODE_MUST_BE_FREE) { 1476 1477 if (idx + slots - 1 >= DNODES_PER_BLOCK) { 1478 DNODE_STAT_BUMP(dnode_hold_free_overflow); 1479 dbuf_rele(db, FTAG); 1480 return (SET_ERROR(ENOSPC)); 1481 } 1482 1483 dnode_slots_hold(dnc, idx, slots); 1484 1485 if (!dnode_check_slots_free(dnc, idx, slots)) { 1486 DNODE_STAT_BUMP(dnode_hold_free_misses); 1487 dnode_slots_rele(dnc, idx, slots); 1488 dbuf_rele(db, FTAG); 1489 return (SET_ERROR(ENOSPC)); 1490 } 1491 1492 dnode_slots_rele(dnc, idx, slots); 1493 while (!dnode_slots_tryenter(dnc, idx, slots)) { 1494 DNODE_STAT_BUMP(dnode_hold_free_lock_retry); 1495 cond_resched(); 1496 } 1497 1498 if (!dnode_check_slots_free(dnc, idx, slots)) { 1499 DNODE_STAT_BUMP(dnode_hold_free_lock_misses); 1500 dnode_slots_rele(dnc, idx, slots); 1501 dbuf_rele(db, FTAG); 1502 return (SET_ERROR(ENOSPC)); 1503 } 1504 1505 /* 1506 * Allocated but otherwise free dnodes which would 1507 * be in the interior of a multi-slot dnodes need 1508 * to be freed. Single slot dnodes can be safely 1509 * re-purposed as a performance optimization. 1510 */ 1511 if (slots > 1) 1512 dnode_reclaim_slots(dnc, idx + 1, slots - 1); 1513 1514 dnh = &dnc->dnc_children[idx]; 1515 if (DN_SLOT_IS_PTR(dnh->dnh_dnode)) { 1516 dn = dnh->dnh_dnode; 1517 } else { 1518 dn = dnode_create(os, dn_block + idx, db, 1519 object, dnh); 1520 } 1521 1522 mutex_enter(&dn->dn_mtx); 1523 if (!zfs_refcount_is_zero(&dn->dn_holds) || dn->dn_free_txg) { 1524 DNODE_STAT_BUMP(dnode_hold_free_refcount); 1525 mutex_exit(&dn->dn_mtx); 1526 dnode_slots_rele(dnc, idx, slots); 1527 dbuf_rele(db, FTAG); 1528 return (SET_ERROR(EEXIST)); 1529 } 1530 1531 /* Don't actually hold if dry run, just return 0 */ 1532 if (flag & DNODE_DRY_RUN) { 1533 mutex_exit(&dn->dn_mtx); 1534 dnode_slots_rele(dnc, idx, slots); 1535 dbuf_rele(db, FTAG); 1536 return (0); 1537 } 1538 1539 dnode_set_slots(dnc, idx + 1, slots - 1, DN_SLOT_INTERIOR); 1540 DNODE_STAT_BUMP(dnode_hold_free_hits); 1541 } else { 1542 dbuf_rele(db, FTAG); 1543 return (SET_ERROR(EINVAL)); 1544 } 1545 1546 ASSERT0(dn->dn_free_txg); 1547 1548 if (zfs_refcount_add(&dn->dn_holds, tag) == 1) 1549 dbuf_add_ref(db, dnh); 1550 1551 mutex_exit(&dn->dn_mtx); 1552 1553 /* Now we can rely on the hold to prevent the dnode from moving. */ 1554 dnode_slots_rele(dnc, idx, slots); 1555 1556 DNODE_VERIFY(dn); 1557 ASSERT3P(dnp, !=, NULL); 1558 ASSERT3P(dn->dn_dbuf, ==, db); 1559 ASSERT3U(dn->dn_object, ==, object); 1560 dbuf_rele(db, FTAG); 1561 1562 *dnp = dn; 1563 return (0); 1564 } 1565 1566 /* 1567 * Return held dnode if the object is allocated, NULL if not. 1568 */ 1569 int 1570 dnode_hold(objset_t *os, uint64_t object, void *tag, dnode_t **dnp) 1571 { 1572 return (dnode_hold_impl(os, object, DNODE_MUST_BE_ALLOCATED, 0, tag, 1573 dnp)); 1574 } 1575 1576 /* 1577 * Can only add a reference if there is already at least one 1578 * reference on the dnode. Returns FALSE if unable to add a 1579 * new reference. 1580 */ 1581 boolean_t 1582 dnode_add_ref(dnode_t *dn, void *tag) 1583 { 1584 mutex_enter(&dn->dn_mtx); 1585 if (zfs_refcount_is_zero(&dn->dn_holds)) { 1586 mutex_exit(&dn->dn_mtx); 1587 return (FALSE); 1588 } 1589 VERIFY(1 < zfs_refcount_add(&dn->dn_holds, tag)); 1590 mutex_exit(&dn->dn_mtx); 1591 return (TRUE); 1592 } 1593 1594 void 1595 dnode_rele(dnode_t *dn, void *tag) 1596 { 1597 mutex_enter(&dn->dn_mtx); 1598 dnode_rele_and_unlock(dn, tag, B_FALSE); 1599 } 1600 1601 void 1602 dnode_rele_and_unlock(dnode_t *dn, void *tag, boolean_t evicting) 1603 { 1604 uint64_t refs; 1605 /* Get while the hold prevents the dnode from moving. */ 1606 dmu_buf_impl_t *db = dn->dn_dbuf; 1607 dnode_handle_t *dnh = dn->dn_handle; 1608 1609 refs = zfs_refcount_remove(&dn->dn_holds, tag); 1610 if (refs == 0) 1611 cv_broadcast(&dn->dn_nodnholds); 1612 mutex_exit(&dn->dn_mtx); 1613 /* dnode could get destroyed at this point, so don't use it anymore */ 1614 1615 /* 1616 * It's unsafe to release the last hold on a dnode by dnode_rele() or 1617 * indirectly by dbuf_rele() while relying on the dnode handle to 1618 * prevent the dnode from moving, since releasing the last hold could 1619 * result in the dnode's parent dbuf evicting its dnode handles. For 1620 * that reason anyone calling dnode_rele() or dbuf_rele() without some 1621 * other direct or indirect hold on the dnode must first drop the dnode 1622 * handle. 1623 */ 1624 ASSERT(refs > 0 || dnh->dnh_zrlock.zr_owner != curthread); 1625 1626 /* NOTE: the DNODE_DNODE does not have a dn_dbuf */ 1627 if (refs == 0 && db != NULL) { 1628 /* 1629 * Another thread could add a hold to the dnode handle in 1630 * dnode_hold_impl() while holding the parent dbuf. Since the 1631 * hold on the parent dbuf prevents the handle from being 1632 * destroyed, the hold on the handle is OK. We can't yet assert 1633 * that the handle has zero references, but that will be 1634 * asserted anyway when the handle gets destroyed. 1635 */ 1636 mutex_enter(&db->db_mtx); 1637 dbuf_rele_and_unlock(db, dnh, evicting); 1638 } 1639 } 1640 1641 /* 1642 * Test whether we can create a dnode at the specified location. 1643 */ 1644 int 1645 dnode_try_claim(objset_t *os, uint64_t object, int slots) 1646 { 1647 return (dnode_hold_impl(os, object, DNODE_MUST_BE_FREE | DNODE_DRY_RUN, 1648 slots, NULL, NULL)); 1649 } 1650 1651 void 1652 dnode_setdirty(dnode_t *dn, dmu_tx_t *tx) 1653 { 1654 objset_t *os = dn->dn_objset; 1655 uint64_t txg = tx->tx_txg; 1656 1657 if (DMU_OBJECT_IS_SPECIAL(dn->dn_object)) { 1658 dsl_dataset_dirty(os->os_dsl_dataset, tx); 1659 return; 1660 } 1661 1662 DNODE_VERIFY(dn); 1663 1664 #ifdef ZFS_DEBUG 1665 mutex_enter(&dn->dn_mtx); 1666 ASSERT(dn->dn_phys->dn_type || dn->dn_allocated_txg); 1667 ASSERT(dn->dn_free_txg == 0 || dn->dn_free_txg >= txg); 1668 mutex_exit(&dn->dn_mtx); 1669 #endif 1670 1671 /* 1672 * Determine old uid/gid when necessary 1673 */ 1674 dmu_objset_userquota_get_ids(dn, B_TRUE, tx); 1675 1676 multilist_t *dirtylist = &os->os_dirty_dnodes[txg & TXG_MASK]; 1677 multilist_sublist_t *mls = multilist_sublist_lock_obj(dirtylist, dn); 1678 1679 /* 1680 * If we are already marked dirty, we're done. 1681 */ 1682 if (multilist_link_active(&dn->dn_dirty_link[txg & TXG_MASK])) { 1683 multilist_sublist_unlock(mls); 1684 return; 1685 } 1686 1687 ASSERT(!zfs_refcount_is_zero(&dn->dn_holds) || 1688 !avl_is_empty(&dn->dn_dbufs)); 1689 ASSERT(dn->dn_datablksz != 0); 1690 ASSERT0(dn->dn_next_bonuslen[txg & TXG_MASK]); 1691 ASSERT0(dn->dn_next_blksz[txg & TXG_MASK]); 1692 ASSERT0(dn->dn_next_bonustype[txg & TXG_MASK]); 1693 1694 dprintf_ds(os->os_dsl_dataset, "obj=%llu txg=%llu\n", 1695 (u_longlong_t)dn->dn_object, (u_longlong_t)txg); 1696 1697 multilist_sublist_insert_head(mls, dn); 1698 1699 multilist_sublist_unlock(mls); 1700 1701 /* 1702 * The dnode maintains a hold on its containing dbuf as 1703 * long as there are holds on it. Each instantiated child 1704 * dbuf maintains a hold on the dnode. When the last child 1705 * drops its hold, the dnode will drop its hold on the 1706 * containing dbuf. We add a "dirty hold" here so that the 1707 * dnode will hang around after we finish processing its 1708 * children. 1709 */ 1710 VERIFY(dnode_add_ref(dn, (void *)(uintptr_t)tx->tx_txg)); 1711 1712 (void) dbuf_dirty(dn->dn_dbuf, tx); 1713 1714 dsl_dataset_dirty(os->os_dsl_dataset, tx); 1715 } 1716 1717 void 1718 dnode_free(dnode_t *dn, dmu_tx_t *tx) 1719 { 1720 mutex_enter(&dn->dn_mtx); 1721 if (dn->dn_type == DMU_OT_NONE || dn->dn_free_txg) { 1722 mutex_exit(&dn->dn_mtx); 1723 return; 1724 } 1725 dn->dn_free_txg = tx->tx_txg; 1726 mutex_exit(&dn->dn_mtx); 1727 1728 dnode_setdirty(dn, tx); 1729 } 1730 1731 /* 1732 * Try to change the block size for the indicated dnode. This can only 1733 * succeed if there are no blocks allocated or dirty beyond first block 1734 */ 1735 int 1736 dnode_set_blksz(dnode_t *dn, uint64_t size, int ibs, dmu_tx_t *tx) 1737 { 1738 dmu_buf_impl_t *db; 1739 int err; 1740 1741 ASSERT3U(size, <=, spa_maxblocksize(dmu_objset_spa(dn->dn_objset))); 1742 if (size == 0) 1743 size = SPA_MINBLOCKSIZE; 1744 else 1745 size = P2ROUNDUP(size, SPA_MINBLOCKSIZE); 1746 1747 if (ibs == dn->dn_indblkshift) 1748 ibs = 0; 1749 1750 if (size >> SPA_MINBLOCKSHIFT == dn->dn_datablkszsec && ibs == 0) 1751 return (0); 1752 1753 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 1754 1755 /* Check for any allocated blocks beyond the first */ 1756 if (dn->dn_maxblkid != 0) 1757 goto fail; 1758 1759 mutex_enter(&dn->dn_dbufs_mtx); 1760 for (db = avl_first(&dn->dn_dbufs); db != NULL; 1761 db = AVL_NEXT(&dn->dn_dbufs, db)) { 1762 if (db->db_blkid != 0 && db->db_blkid != DMU_BONUS_BLKID && 1763 db->db_blkid != DMU_SPILL_BLKID) { 1764 mutex_exit(&dn->dn_dbufs_mtx); 1765 goto fail; 1766 } 1767 } 1768 mutex_exit(&dn->dn_dbufs_mtx); 1769 1770 if (ibs && dn->dn_nlevels != 1) 1771 goto fail; 1772 1773 /* resize the old block */ 1774 err = dbuf_hold_impl(dn, 0, 0, TRUE, FALSE, FTAG, &db); 1775 if (err == 0) { 1776 dbuf_new_size(db, size, tx); 1777 } else if (err != ENOENT) { 1778 goto fail; 1779 } 1780 1781 dnode_setdblksz(dn, size); 1782 dnode_setdirty(dn, tx); 1783 dn->dn_next_blksz[tx->tx_txg&TXG_MASK] = size; 1784 if (ibs) { 1785 dn->dn_indblkshift = ibs; 1786 dn->dn_next_indblkshift[tx->tx_txg&TXG_MASK] = ibs; 1787 } 1788 /* release after we have fixed the blocksize in the dnode */ 1789 if (db) 1790 dbuf_rele(db, FTAG); 1791 1792 rw_exit(&dn->dn_struct_rwlock); 1793 return (0); 1794 1795 fail: 1796 rw_exit(&dn->dn_struct_rwlock); 1797 return (SET_ERROR(ENOTSUP)); 1798 } 1799 1800 static void 1801 dnode_set_nlevels_impl(dnode_t *dn, int new_nlevels, dmu_tx_t *tx) 1802 { 1803 uint64_t txgoff = tx->tx_txg & TXG_MASK; 1804 int old_nlevels = dn->dn_nlevels; 1805 dmu_buf_impl_t *db; 1806 list_t *list; 1807 dbuf_dirty_record_t *new, *dr, *dr_next; 1808 1809 ASSERT(RW_WRITE_HELD(&dn->dn_struct_rwlock)); 1810 1811 ASSERT3U(new_nlevels, >, dn->dn_nlevels); 1812 dn->dn_nlevels = new_nlevels; 1813 1814 ASSERT3U(new_nlevels, >, dn->dn_next_nlevels[txgoff]); 1815 dn->dn_next_nlevels[txgoff] = new_nlevels; 1816 1817 /* dirty the left indirects */ 1818 db = dbuf_hold_level(dn, old_nlevels, 0, FTAG); 1819 ASSERT(db != NULL); 1820 new = dbuf_dirty(db, tx); 1821 dbuf_rele(db, FTAG); 1822 1823 /* transfer the dirty records to the new indirect */ 1824 mutex_enter(&dn->dn_mtx); 1825 mutex_enter(&new->dt.di.dr_mtx); 1826 list = &dn->dn_dirty_records[txgoff]; 1827 for (dr = list_head(list); dr; dr = dr_next) { 1828 dr_next = list_next(&dn->dn_dirty_records[txgoff], dr); 1829 1830 IMPLY(dr->dr_dbuf == NULL, old_nlevels == 1); 1831 if (dr->dr_dbuf == NULL || 1832 (dr->dr_dbuf->db_level == old_nlevels - 1 && 1833 dr->dr_dbuf->db_blkid != DMU_BONUS_BLKID && 1834 dr->dr_dbuf->db_blkid != DMU_SPILL_BLKID)) { 1835 list_remove(&dn->dn_dirty_records[txgoff], dr); 1836 list_insert_tail(&new->dt.di.dr_children, dr); 1837 dr->dr_parent = new; 1838 } 1839 } 1840 mutex_exit(&new->dt.di.dr_mtx); 1841 mutex_exit(&dn->dn_mtx); 1842 } 1843 1844 int 1845 dnode_set_nlevels(dnode_t *dn, int nlevels, dmu_tx_t *tx) 1846 { 1847 int ret = 0; 1848 1849 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 1850 1851 if (dn->dn_nlevels == nlevels) { 1852 ret = 0; 1853 goto out; 1854 } else if (nlevels < dn->dn_nlevels) { 1855 ret = SET_ERROR(EINVAL); 1856 goto out; 1857 } 1858 1859 dnode_set_nlevels_impl(dn, nlevels, tx); 1860 1861 out: 1862 rw_exit(&dn->dn_struct_rwlock); 1863 return (ret); 1864 } 1865 1866 /* read-holding callers must not rely on the lock being continuously held */ 1867 void 1868 dnode_new_blkid(dnode_t *dn, uint64_t blkid, dmu_tx_t *tx, boolean_t have_read, 1869 boolean_t force) 1870 { 1871 int epbs, new_nlevels; 1872 uint64_t sz; 1873 1874 ASSERT(blkid != DMU_BONUS_BLKID); 1875 1876 ASSERT(have_read ? 1877 RW_READ_HELD(&dn->dn_struct_rwlock) : 1878 RW_WRITE_HELD(&dn->dn_struct_rwlock)); 1879 1880 /* 1881 * if we have a read-lock, check to see if we need to do any work 1882 * before upgrading to a write-lock. 1883 */ 1884 if (have_read) { 1885 if (blkid <= dn->dn_maxblkid) 1886 return; 1887 1888 if (!rw_tryupgrade(&dn->dn_struct_rwlock)) { 1889 rw_exit(&dn->dn_struct_rwlock); 1890 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 1891 } 1892 } 1893 1894 /* 1895 * Raw sends (indicated by the force flag) require that we take the 1896 * given blkid even if the value is lower than the current value. 1897 */ 1898 if (!force && blkid <= dn->dn_maxblkid) 1899 goto out; 1900 1901 /* 1902 * We use the (otherwise unused) top bit of dn_next_maxblkid[txgoff] 1903 * to indicate that this field is set. This allows us to set the 1904 * maxblkid to 0 on an existing object in dnode_sync(). 1905 */ 1906 dn->dn_maxblkid = blkid; 1907 dn->dn_next_maxblkid[tx->tx_txg & TXG_MASK] = 1908 blkid | DMU_NEXT_MAXBLKID_SET; 1909 1910 /* 1911 * Compute the number of levels necessary to support the new maxblkid. 1912 * Raw sends will ensure nlevels is set correctly for us. 1913 */ 1914 new_nlevels = 1; 1915 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT; 1916 for (sz = dn->dn_nblkptr; 1917 sz <= blkid && sz >= dn->dn_nblkptr; sz <<= epbs) 1918 new_nlevels++; 1919 1920 ASSERT3U(new_nlevels, <=, DN_MAX_LEVELS); 1921 1922 if (!force) { 1923 if (new_nlevels > dn->dn_nlevels) 1924 dnode_set_nlevels_impl(dn, new_nlevels, tx); 1925 } else { 1926 ASSERT3U(dn->dn_nlevels, >=, new_nlevels); 1927 } 1928 1929 out: 1930 if (have_read) 1931 rw_downgrade(&dn->dn_struct_rwlock); 1932 } 1933 1934 static void 1935 dnode_dirty_l1(dnode_t *dn, uint64_t l1blkid, dmu_tx_t *tx) 1936 { 1937 dmu_buf_impl_t *db = dbuf_hold_level(dn, 1, l1blkid, FTAG); 1938 if (db != NULL) { 1939 dmu_buf_will_dirty(&db->db, tx); 1940 dbuf_rele(db, FTAG); 1941 } 1942 } 1943 1944 /* 1945 * Dirty all the in-core level-1 dbufs in the range specified by start_blkid 1946 * and end_blkid. 1947 */ 1948 static void 1949 dnode_dirty_l1range(dnode_t *dn, uint64_t start_blkid, uint64_t end_blkid, 1950 dmu_tx_t *tx) 1951 { 1952 dmu_buf_impl_t *db_search; 1953 dmu_buf_impl_t *db; 1954 avl_index_t where; 1955 1956 db_search = kmem_zalloc(sizeof (dmu_buf_impl_t), KM_SLEEP); 1957 1958 mutex_enter(&dn->dn_dbufs_mtx); 1959 1960 db_search->db_level = 1; 1961 db_search->db_blkid = start_blkid + 1; 1962 db_search->db_state = DB_SEARCH; 1963 for (;;) { 1964 1965 db = avl_find(&dn->dn_dbufs, db_search, &where); 1966 if (db == NULL) 1967 db = avl_nearest(&dn->dn_dbufs, where, AVL_AFTER); 1968 1969 if (db == NULL || db->db_level != 1 || 1970 db->db_blkid >= end_blkid) { 1971 break; 1972 } 1973 1974 /* 1975 * Setup the next blkid we want to search for. 1976 */ 1977 db_search->db_blkid = db->db_blkid + 1; 1978 ASSERT3U(db->db_blkid, >=, start_blkid); 1979 1980 /* 1981 * If the dbuf transitions to DB_EVICTING while we're trying 1982 * to dirty it, then we will be unable to discover it in 1983 * the dbuf hash table. This will result in a call to 1984 * dbuf_create() which needs to acquire the dn_dbufs_mtx 1985 * lock. To avoid a deadlock, we drop the lock before 1986 * dirtying the level-1 dbuf. 1987 */ 1988 mutex_exit(&dn->dn_dbufs_mtx); 1989 dnode_dirty_l1(dn, db->db_blkid, tx); 1990 mutex_enter(&dn->dn_dbufs_mtx); 1991 } 1992 1993 #ifdef ZFS_DEBUG 1994 /* 1995 * Walk all the in-core level-1 dbufs and verify they have been dirtied. 1996 */ 1997 db_search->db_level = 1; 1998 db_search->db_blkid = start_blkid + 1; 1999 db_search->db_state = DB_SEARCH; 2000 db = avl_find(&dn->dn_dbufs, db_search, &where); 2001 if (db == NULL) 2002 db = avl_nearest(&dn->dn_dbufs, where, AVL_AFTER); 2003 for (; db != NULL; db = AVL_NEXT(&dn->dn_dbufs, db)) { 2004 if (db->db_level != 1 || db->db_blkid >= end_blkid) 2005 break; 2006 if (db->db_state != DB_EVICTING) 2007 ASSERT(db->db_dirtycnt > 0); 2008 } 2009 #endif 2010 kmem_free(db_search, sizeof (dmu_buf_impl_t)); 2011 mutex_exit(&dn->dn_dbufs_mtx); 2012 } 2013 2014 void 2015 dnode_set_dirtyctx(dnode_t *dn, dmu_tx_t *tx, void *tag) 2016 { 2017 /* 2018 * Don't set dirtyctx to SYNC if we're just modifying this as we 2019 * initialize the objset. 2020 */ 2021 if (dn->dn_dirtyctx == DN_UNDIRTIED) { 2022 dsl_dataset_t *ds = dn->dn_objset->os_dsl_dataset; 2023 2024 if (ds != NULL) { 2025 rrw_enter(&ds->ds_bp_rwlock, RW_READER, tag); 2026 } 2027 if (!BP_IS_HOLE(dn->dn_objset->os_rootbp)) { 2028 if (dmu_tx_is_syncing(tx)) 2029 dn->dn_dirtyctx = DN_DIRTY_SYNC; 2030 else 2031 dn->dn_dirtyctx = DN_DIRTY_OPEN; 2032 dn->dn_dirtyctx_firstset = tag; 2033 } 2034 if (ds != NULL) { 2035 rrw_exit(&ds->ds_bp_rwlock, tag); 2036 } 2037 } 2038 } 2039 2040 void 2041 dnode_free_range(dnode_t *dn, uint64_t off, uint64_t len, dmu_tx_t *tx) 2042 { 2043 dmu_buf_impl_t *db; 2044 uint64_t blkoff, blkid, nblks; 2045 int blksz, blkshift, head, tail; 2046 int trunc = FALSE; 2047 int epbs; 2048 2049 blksz = dn->dn_datablksz; 2050 blkshift = dn->dn_datablkshift; 2051 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT; 2052 2053 if (len == DMU_OBJECT_END) { 2054 len = UINT64_MAX - off; 2055 trunc = TRUE; 2056 } 2057 2058 /* 2059 * First, block align the region to free: 2060 */ 2061 if (ISP2(blksz)) { 2062 head = P2NPHASE(off, blksz); 2063 blkoff = P2PHASE(off, blksz); 2064 if ((off >> blkshift) > dn->dn_maxblkid) 2065 return; 2066 } else { 2067 ASSERT(dn->dn_maxblkid == 0); 2068 if (off == 0 && len >= blksz) { 2069 /* 2070 * Freeing the whole block; fast-track this request. 2071 */ 2072 blkid = 0; 2073 nblks = 1; 2074 if (dn->dn_nlevels > 1) { 2075 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 2076 dnode_dirty_l1(dn, 0, tx); 2077 rw_exit(&dn->dn_struct_rwlock); 2078 } 2079 goto done; 2080 } else if (off >= blksz) { 2081 /* Freeing past end-of-data */ 2082 return; 2083 } else { 2084 /* Freeing part of the block. */ 2085 head = blksz - off; 2086 ASSERT3U(head, >, 0); 2087 } 2088 blkoff = off; 2089 } 2090 /* zero out any partial block data at the start of the range */ 2091 if (head) { 2092 int res; 2093 ASSERT3U(blkoff + head, ==, blksz); 2094 if (len < head) 2095 head = len; 2096 rw_enter(&dn->dn_struct_rwlock, RW_READER); 2097 res = dbuf_hold_impl(dn, 0, dbuf_whichblock(dn, 0, off), 2098 TRUE, FALSE, FTAG, &db); 2099 rw_exit(&dn->dn_struct_rwlock); 2100 if (res == 0) { 2101 caddr_t data; 2102 boolean_t dirty; 2103 2104 db_lock_type_t dblt = dmu_buf_lock_parent(db, RW_READER, 2105 FTAG); 2106 /* don't dirty if it isn't on disk and isn't dirty */ 2107 dirty = !list_is_empty(&db->db_dirty_records) || 2108 (db->db_blkptr && !BP_IS_HOLE(db->db_blkptr)); 2109 dmu_buf_unlock_parent(db, dblt, FTAG); 2110 if (dirty) { 2111 dmu_buf_will_dirty(&db->db, tx); 2112 data = db->db.db_data; 2113 bzero(data + blkoff, head); 2114 } 2115 dbuf_rele(db, FTAG); 2116 } 2117 off += head; 2118 len -= head; 2119 } 2120 2121 /* If the range was less than one block, we're done */ 2122 if (len == 0) 2123 return; 2124 2125 /* If the remaining range is past end of file, we're done */ 2126 if ((off >> blkshift) > dn->dn_maxblkid) 2127 return; 2128 2129 ASSERT(ISP2(blksz)); 2130 if (trunc) 2131 tail = 0; 2132 else 2133 tail = P2PHASE(len, blksz); 2134 2135 ASSERT0(P2PHASE(off, blksz)); 2136 /* zero out any partial block data at the end of the range */ 2137 if (tail) { 2138 int res; 2139 if (len < tail) 2140 tail = len; 2141 rw_enter(&dn->dn_struct_rwlock, RW_READER); 2142 res = dbuf_hold_impl(dn, 0, dbuf_whichblock(dn, 0, off+len), 2143 TRUE, FALSE, FTAG, &db); 2144 rw_exit(&dn->dn_struct_rwlock); 2145 if (res == 0) { 2146 boolean_t dirty; 2147 /* don't dirty if not on disk and not dirty */ 2148 db_lock_type_t type = dmu_buf_lock_parent(db, RW_READER, 2149 FTAG); 2150 dirty = !list_is_empty(&db->db_dirty_records) || 2151 (db->db_blkptr && !BP_IS_HOLE(db->db_blkptr)); 2152 dmu_buf_unlock_parent(db, type, FTAG); 2153 if (dirty) { 2154 dmu_buf_will_dirty(&db->db, tx); 2155 bzero(db->db.db_data, tail); 2156 } 2157 dbuf_rele(db, FTAG); 2158 } 2159 len -= tail; 2160 } 2161 2162 /* If the range did not include a full block, we are done */ 2163 if (len == 0) 2164 return; 2165 2166 ASSERT(IS_P2ALIGNED(off, blksz)); 2167 ASSERT(trunc || IS_P2ALIGNED(len, blksz)); 2168 blkid = off >> blkshift; 2169 nblks = len >> blkshift; 2170 if (trunc) 2171 nblks += 1; 2172 2173 /* 2174 * Dirty all the indirect blocks in this range. Note that only 2175 * the first and last indirect blocks can actually be written 2176 * (if they were partially freed) -- they must be dirtied, even if 2177 * they do not exist on disk yet. The interior blocks will 2178 * be freed by free_children(), so they will not actually be written. 2179 * Even though these interior blocks will not be written, we 2180 * dirty them for two reasons: 2181 * 2182 * - It ensures that the indirect blocks remain in memory until 2183 * syncing context. (They have already been prefetched by 2184 * dmu_tx_hold_free(), so we don't have to worry about reading 2185 * them serially here.) 2186 * 2187 * - The dirty space accounting will put pressure on the txg sync 2188 * mechanism to begin syncing, and to delay transactions if there 2189 * is a large amount of freeing. Even though these indirect 2190 * blocks will not be written, we could need to write the same 2191 * amount of space if we copy the freed BPs into deadlists. 2192 */ 2193 if (dn->dn_nlevels > 1) { 2194 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 2195 uint64_t first, last; 2196 2197 first = blkid >> epbs; 2198 dnode_dirty_l1(dn, first, tx); 2199 if (trunc) 2200 last = dn->dn_maxblkid >> epbs; 2201 else 2202 last = (blkid + nblks - 1) >> epbs; 2203 if (last != first) 2204 dnode_dirty_l1(dn, last, tx); 2205 2206 dnode_dirty_l1range(dn, first, last, tx); 2207 2208 int shift = dn->dn_datablkshift + dn->dn_indblkshift - 2209 SPA_BLKPTRSHIFT; 2210 for (uint64_t i = first + 1; i < last; i++) { 2211 /* 2212 * Set i to the blockid of the next non-hole 2213 * level-1 indirect block at or after i. Note 2214 * that dnode_next_offset() operates in terms of 2215 * level-0-equivalent bytes. 2216 */ 2217 uint64_t ibyte = i << shift; 2218 int err = dnode_next_offset(dn, DNODE_FIND_HAVELOCK, 2219 &ibyte, 2, 1, 0); 2220 i = ibyte >> shift; 2221 if (i >= last) 2222 break; 2223 2224 /* 2225 * Normally we should not see an error, either 2226 * from dnode_next_offset() or dbuf_hold_level() 2227 * (except for ESRCH from dnode_next_offset). 2228 * If there is an i/o error, then when we read 2229 * this block in syncing context, it will use 2230 * ZIO_FLAG_MUSTSUCCEED, and thus hang/panic according 2231 * to the "failmode" property. dnode_next_offset() 2232 * doesn't have a flag to indicate MUSTSUCCEED. 2233 */ 2234 if (err != 0) 2235 break; 2236 2237 dnode_dirty_l1(dn, i, tx); 2238 } 2239 rw_exit(&dn->dn_struct_rwlock); 2240 } 2241 2242 done: 2243 /* 2244 * Add this range to the dnode range list. 2245 * We will finish up this free operation in the syncing phase. 2246 */ 2247 mutex_enter(&dn->dn_mtx); 2248 { 2249 int txgoff = tx->tx_txg & TXG_MASK; 2250 if (dn->dn_free_ranges[txgoff] == NULL) { 2251 dn->dn_free_ranges[txgoff] = range_tree_create(NULL, 2252 RANGE_SEG64, NULL, 0, 0); 2253 } 2254 range_tree_clear(dn->dn_free_ranges[txgoff], blkid, nblks); 2255 range_tree_add(dn->dn_free_ranges[txgoff], blkid, nblks); 2256 } 2257 dprintf_dnode(dn, "blkid=%llu nblks=%llu txg=%llu\n", 2258 (u_longlong_t)blkid, (u_longlong_t)nblks, 2259 (u_longlong_t)tx->tx_txg); 2260 mutex_exit(&dn->dn_mtx); 2261 2262 dbuf_free_range(dn, blkid, blkid + nblks - 1, tx); 2263 dnode_setdirty(dn, tx); 2264 } 2265 2266 static boolean_t 2267 dnode_spill_freed(dnode_t *dn) 2268 { 2269 int i; 2270 2271 mutex_enter(&dn->dn_mtx); 2272 for (i = 0; i < TXG_SIZE; i++) { 2273 if (dn->dn_rm_spillblk[i] == DN_KILL_SPILLBLK) 2274 break; 2275 } 2276 mutex_exit(&dn->dn_mtx); 2277 return (i < TXG_SIZE); 2278 } 2279 2280 /* return TRUE if this blkid was freed in a recent txg, or FALSE if it wasn't */ 2281 uint64_t 2282 dnode_block_freed(dnode_t *dn, uint64_t blkid) 2283 { 2284 void *dp = spa_get_dsl(dn->dn_objset->os_spa); 2285 int i; 2286 2287 if (blkid == DMU_BONUS_BLKID) 2288 return (FALSE); 2289 2290 /* 2291 * If we're in the process of opening the pool, dp will not be 2292 * set yet, but there shouldn't be anything dirty. 2293 */ 2294 if (dp == NULL) 2295 return (FALSE); 2296 2297 if (dn->dn_free_txg) 2298 return (TRUE); 2299 2300 if (blkid == DMU_SPILL_BLKID) 2301 return (dnode_spill_freed(dn)); 2302 2303 mutex_enter(&dn->dn_mtx); 2304 for (i = 0; i < TXG_SIZE; i++) { 2305 if (dn->dn_free_ranges[i] != NULL && 2306 range_tree_contains(dn->dn_free_ranges[i], blkid, 1)) 2307 break; 2308 } 2309 mutex_exit(&dn->dn_mtx); 2310 return (i < TXG_SIZE); 2311 } 2312 2313 /* call from syncing context when we actually write/free space for this dnode */ 2314 void 2315 dnode_diduse_space(dnode_t *dn, int64_t delta) 2316 { 2317 uint64_t space; 2318 dprintf_dnode(dn, "dn=%p dnp=%p used=%llu delta=%lld\n", 2319 dn, dn->dn_phys, 2320 (u_longlong_t)dn->dn_phys->dn_used, 2321 (longlong_t)delta); 2322 2323 mutex_enter(&dn->dn_mtx); 2324 space = DN_USED_BYTES(dn->dn_phys); 2325 if (delta > 0) { 2326 ASSERT3U(space + delta, >=, space); /* no overflow */ 2327 } else { 2328 ASSERT3U(space, >=, -delta); /* no underflow */ 2329 } 2330 space += delta; 2331 if (spa_version(dn->dn_objset->os_spa) < SPA_VERSION_DNODE_BYTES) { 2332 ASSERT((dn->dn_phys->dn_flags & DNODE_FLAG_USED_BYTES) == 0); 2333 ASSERT0(P2PHASE(space, 1<<DEV_BSHIFT)); 2334 dn->dn_phys->dn_used = space >> DEV_BSHIFT; 2335 } else { 2336 dn->dn_phys->dn_used = space; 2337 dn->dn_phys->dn_flags |= DNODE_FLAG_USED_BYTES; 2338 } 2339 mutex_exit(&dn->dn_mtx); 2340 } 2341 2342 /* 2343 * Scans a block at the indicated "level" looking for a hole or data, 2344 * depending on 'flags'. 2345 * 2346 * If level > 0, then we are scanning an indirect block looking at its 2347 * pointers. If level == 0, then we are looking at a block of dnodes. 2348 * 2349 * If we don't find what we are looking for in the block, we return ESRCH. 2350 * Otherwise, return with *offset pointing to the beginning (if searching 2351 * forwards) or end (if searching backwards) of the range covered by the 2352 * block pointer we matched on (or dnode). 2353 * 2354 * The basic search algorithm used below by dnode_next_offset() is to 2355 * use this function to search up the block tree (widen the search) until 2356 * we find something (i.e., we don't return ESRCH) and then search back 2357 * down the tree (narrow the search) until we reach our original search 2358 * level. 2359 */ 2360 static int 2361 dnode_next_offset_level(dnode_t *dn, int flags, uint64_t *offset, 2362 int lvl, uint64_t blkfill, uint64_t txg) 2363 { 2364 dmu_buf_impl_t *db = NULL; 2365 void *data = NULL; 2366 uint64_t epbs = dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT; 2367 uint64_t epb = 1ULL << epbs; 2368 uint64_t minfill, maxfill; 2369 boolean_t hole; 2370 int i, inc, error, span; 2371 2372 ASSERT(RW_LOCK_HELD(&dn->dn_struct_rwlock)); 2373 2374 hole = ((flags & DNODE_FIND_HOLE) != 0); 2375 inc = (flags & DNODE_FIND_BACKWARDS) ? -1 : 1; 2376 ASSERT(txg == 0 || !hole); 2377 2378 if (lvl == dn->dn_phys->dn_nlevels) { 2379 error = 0; 2380 epb = dn->dn_phys->dn_nblkptr; 2381 data = dn->dn_phys->dn_blkptr; 2382 } else { 2383 uint64_t blkid = dbuf_whichblock(dn, lvl, *offset); 2384 error = dbuf_hold_impl(dn, lvl, blkid, TRUE, FALSE, FTAG, &db); 2385 if (error) { 2386 if (error != ENOENT) 2387 return (error); 2388 if (hole) 2389 return (0); 2390 /* 2391 * This can only happen when we are searching up 2392 * the block tree for data. We don't really need to 2393 * adjust the offset, as we will just end up looking 2394 * at the pointer to this block in its parent, and its 2395 * going to be unallocated, so we will skip over it. 2396 */ 2397 return (SET_ERROR(ESRCH)); 2398 } 2399 error = dbuf_read(db, NULL, 2400 DB_RF_CANFAIL | DB_RF_HAVESTRUCT | 2401 DB_RF_NO_DECRYPT | DB_RF_NOPREFETCH); 2402 if (error) { 2403 dbuf_rele(db, FTAG); 2404 return (error); 2405 } 2406 data = db->db.db_data; 2407 rw_enter(&db->db_rwlock, RW_READER); 2408 } 2409 2410 if (db != NULL && txg != 0 && (db->db_blkptr == NULL || 2411 db->db_blkptr->blk_birth <= txg || 2412 BP_IS_HOLE(db->db_blkptr))) { 2413 /* 2414 * This can only happen when we are searching up the tree 2415 * and these conditions mean that we need to keep climbing. 2416 */ 2417 error = SET_ERROR(ESRCH); 2418 } else if (lvl == 0) { 2419 dnode_phys_t *dnp = data; 2420 2421 ASSERT(dn->dn_type == DMU_OT_DNODE); 2422 ASSERT(!(flags & DNODE_FIND_BACKWARDS)); 2423 2424 for (i = (*offset >> DNODE_SHIFT) & (blkfill - 1); 2425 i < blkfill; i += dnp[i].dn_extra_slots + 1) { 2426 if ((dnp[i].dn_type == DMU_OT_NONE) == hole) 2427 break; 2428 } 2429 2430 if (i == blkfill) 2431 error = SET_ERROR(ESRCH); 2432 2433 *offset = (*offset & ~(DNODE_BLOCK_SIZE - 1)) + 2434 (i << DNODE_SHIFT); 2435 } else { 2436 blkptr_t *bp = data; 2437 uint64_t start = *offset; 2438 span = (lvl - 1) * epbs + dn->dn_datablkshift; 2439 minfill = 0; 2440 maxfill = blkfill << ((lvl - 1) * epbs); 2441 2442 if (hole) 2443 maxfill--; 2444 else 2445 minfill++; 2446 2447 if (span >= 8 * sizeof (*offset)) { 2448 /* This only happens on the highest indirection level */ 2449 ASSERT3U((lvl - 1), ==, dn->dn_phys->dn_nlevels - 1); 2450 *offset = 0; 2451 } else { 2452 *offset = *offset >> span; 2453 } 2454 2455 for (i = BF64_GET(*offset, 0, epbs); 2456 i >= 0 && i < epb; i += inc) { 2457 if (BP_GET_FILL(&bp[i]) >= minfill && 2458 BP_GET_FILL(&bp[i]) <= maxfill && 2459 (hole || bp[i].blk_birth > txg)) 2460 break; 2461 if (inc > 0 || *offset > 0) 2462 *offset += inc; 2463 } 2464 2465 if (span >= 8 * sizeof (*offset)) { 2466 *offset = start; 2467 } else { 2468 *offset = *offset << span; 2469 } 2470 2471 if (inc < 0) { 2472 /* traversing backwards; position offset at the end */ 2473 ASSERT3U(*offset, <=, start); 2474 *offset = MIN(*offset + (1ULL << span) - 1, start); 2475 } else if (*offset < start) { 2476 *offset = start; 2477 } 2478 if (i < 0 || i >= epb) 2479 error = SET_ERROR(ESRCH); 2480 } 2481 2482 if (db != NULL) { 2483 rw_exit(&db->db_rwlock); 2484 dbuf_rele(db, FTAG); 2485 } 2486 2487 return (error); 2488 } 2489 2490 /* 2491 * Find the next hole, data, or sparse region at or after *offset. 2492 * The value 'blkfill' tells us how many items we expect to find 2493 * in an L0 data block; this value is 1 for normal objects, 2494 * DNODES_PER_BLOCK for the meta dnode, and some fraction of 2495 * DNODES_PER_BLOCK when searching for sparse regions thereof. 2496 * 2497 * Examples: 2498 * 2499 * dnode_next_offset(dn, flags, offset, 1, 1, 0); 2500 * Finds the next/previous hole/data in a file. 2501 * Used in dmu_offset_next(). 2502 * 2503 * dnode_next_offset(mdn, flags, offset, 0, DNODES_PER_BLOCK, txg); 2504 * Finds the next free/allocated dnode an objset's meta-dnode. 2505 * Only finds objects that have new contents since txg (ie. 2506 * bonus buffer changes and content removal are ignored). 2507 * Used in dmu_object_next(). 2508 * 2509 * dnode_next_offset(mdn, DNODE_FIND_HOLE, offset, 2, DNODES_PER_BLOCK >> 2, 0); 2510 * Finds the next L2 meta-dnode bp that's at most 1/4 full. 2511 * Used in dmu_object_alloc(). 2512 */ 2513 int 2514 dnode_next_offset(dnode_t *dn, int flags, uint64_t *offset, 2515 int minlvl, uint64_t blkfill, uint64_t txg) 2516 { 2517 uint64_t initial_offset = *offset; 2518 int lvl, maxlvl; 2519 int error = 0; 2520 2521 if (!(flags & DNODE_FIND_HAVELOCK)) 2522 rw_enter(&dn->dn_struct_rwlock, RW_READER); 2523 2524 if (dn->dn_phys->dn_nlevels == 0) { 2525 error = SET_ERROR(ESRCH); 2526 goto out; 2527 } 2528 2529 if (dn->dn_datablkshift == 0) { 2530 if (*offset < dn->dn_datablksz) { 2531 if (flags & DNODE_FIND_HOLE) 2532 *offset = dn->dn_datablksz; 2533 } else { 2534 error = SET_ERROR(ESRCH); 2535 } 2536 goto out; 2537 } 2538 2539 maxlvl = dn->dn_phys->dn_nlevels; 2540 2541 for (lvl = minlvl; lvl <= maxlvl; lvl++) { 2542 error = dnode_next_offset_level(dn, 2543 flags, offset, lvl, blkfill, txg); 2544 if (error != ESRCH) 2545 break; 2546 } 2547 2548 while (error == 0 && --lvl >= minlvl) { 2549 error = dnode_next_offset_level(dn, 2550 flags, offset, lvl, blkfill, txg); 2551 } 2552 2553 /* 2554 * There's always a "virtual hole" at the end of the object, even 2555 * if all BP's which physically exist are non-holes. 2556 */ 2557 if ((flags & DNODE_FIND_HOLE) && error == ESRCH && txg == 0 && 2558 minlvl == 1 && blkfill == 1 && !(flags & DNODE_FIND_BACKWARDS)) { 2559 error = 0; 2560 } 2561 2562 if (error == 0 && (flags & DNODE_FIND_BACKWARDS ? 2563 initial_offset < *offset : initial_offset > *offset)) 2564 error = SET_ERROR(ESRCH); 2565 out: 2566 if (!(flags & DNODE_FIND_HAVELOCK)) 2567 rw_exit(&dn->dn_struct_rwlock); 2568 2569 return (error); 2570 } 2571 2572 #if defined(_KERNEL) 2573 EXPORT_SYMBOL(dnode_hold); 2574 EXPORT_SYMBOL(dnode_rele); 2575 EXPORT_SYMBOL(dnode_set_nlevels); 2576 EXPORT_SYMBOL(dnode_set_blksz); 2577 EXPORT_SYMBOL(dnode_free_range); 2578 EXPORT_SYMBOL(dnode_evict_dbufs); 2579 EXPORT_SYMBOL(dnode_evict_bonus); 2580 #endif 2581