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 static int 112 dnode_cons(void *arg, void *unused, int kmflag) 113 { 114 (void) unused, (void) kmflag; 115 dnode_t *dn = arg; 116 117 rw_init(&dn->dn_struct_rwlock, NULL, RW_NOLOCKDEP, NULL); 118 mutex_init(&dn->dn_mtx, NULL, MUTEX_DEFAULT, NULL); 119 mutex_init(&dn->dn_dbufs_mtx, NULL, MUTEX_DEFAULT, NULL); 120 cv_init(&dn->dn_notxholds, NULL, CV_DEFAULT, NULL); 121 cv_init(&dn->dn_nodnholds, NULL, CV_DEFAULT, NULL); 122 123 /* 124 * Every dbuf has a reference, and dropping a tracked reference is 125 * O(number of references), so don't track dn_holds. 126 */ 127 zfs_refcount_create_untracked(&dn->dn_holds); 128 zfs_refcount_create(&dn->dn_tx_holds); 129 list_link_init(&dn->dn_link); 130 131 bzero(&dn->dn_next_type[0], sizeof (dn->dn_next_type)); 132 bzero(&dn->dn_next_nblkptr[0], sizeof (dn->dn_next_nblkptr)); 133 bzero(&dn->dn_next_nlevels[0], sizeof (dn->dn_next_nlevels)); 134 bzero(&dn->dn_next_indblkshift[0], sizeof (dn->dn_next_indblkshift)); 135 bzero(&dn->dn_next_bonustype[0], sizeof (dn->dn_next_bonustype)); 136 bzero(&dn->dn_rm_spillblk[0], sizeof (dn->dn_rm_spillblk)); 137 bzero(&dn->dn_next_bonuslen[0], sizeof (dn->dn_next_bonuslen)); 138 bzero(&dn->dn_next_blksz[0], sizeof (dn->dn_next_blksz)); 139 bzero(&dn->dn_next_maxblkid[0], sizeof (dn->dn_next_maxblkid)); 140 141 for (int i = 0; i < TXG_SIZE; i++) { 142 multilist_link_init(&dn->dn_dirty_link[i]); 143 dn->dn_free_ranges[i] = NULL; 144 list_create(&dn->dn_dirty_records[i], 145 sizeof (dbuf_dirty_record_t), 146 offsetof(dbuf_dirty_record_t, dr_dirty_node)); 147 } 148 149 dn->dn_allocated_txg = 0; 150 dn->dn_free_txg = 0; 151 dn->dn_assigned_txg = 0; 152 dn->dn_dirty_txg = 0; 153 dn->dn_dirtyctx = 0; 154 dn->dn_dirtyctx_firstset = NULL; 155 dn->dn_bonus = NULL; 156 dn->dn_have_spill = B_FALSE; 157 dn->dn_zio = NULL; 158 dn->dn_oldused = 0; 159 dn->dn_oldflags = 0; 160 dn->dn_olduid = 0; 161 dn->dn_oldgid = 0; 162 dn->dn_oldprojid = ZFS_DEFAULT_PROJID; 163 dn->dn_newuid = 0; 164 dn->dn_newgid = 0; 165 dn->dn_newprojid = ZFS_DEFAULT_PROJID; 166 dn->dn_id_flags = 0; 167 168 dn->dn_dbufs_count = 0; 169 avl_create(&dn->dn_dbufs, dbuf_compare, sizeof (dmu_buf_impl_t), 170 offsetof(dmu_buf_impl_t, db_link)); 171 172 dn->dn_moved = 0; 173 return (0); 174 } 175 176 static void 177 dnode_dest(void *arg, void *unused) 178 { 179 (void) unused; 180 dnode_t *dn = arg; 181 182 rw_destroy(&dn->dn_struct_rwlock); 183 mutex_destroy(&dn->dn_mtx); 184 mutex_destroy(&dn->dn_dbufs_mtx); 185 cv_destroy(&dn->dn_notxholds); 186 cv_destroy(&dn->dn_nodnholds); 187 zfs_refcount_destroy(&dn->dn_holds); 188 zfs_refcount_destroy(&dn->dn_tx_holds); 189 ASSERT(!list_link_active(&dn->dn_link)); 190 191 for (int i = 0; i < TXG_SIZE; i++) { 192 ASSERT(!multilist_link_active(&dn->dn_dirty_link[i])); 193 ASSERT3P(dn->dn_free_ranges[i], ==, NULL); 194 list_destroy(&dn->dn_dirty_records[i]); 195 ASSERT0(dn->dn_next_nblkptr[i]); 196 ASSERT0(dn->dn_next_nlevels[i]); 197 ASSERT0(dn->dn_next_indblkshift[i]); 198 ASSERT0(dn->dn_next_bonustype[i]); 199 ASSERT0(dn->dn_rm_spillblk[i]); 200 ASSERT0(dn->dn_next_bonuslen[i]); 201 ASSERT0(dn->dn_next_blksz[i]); 202 ASSERT0(dn->dn_next_maxblkid[i]); 203 } 204 205 ASSERT0(dn->dn_allocated_txg); 206 ASSERT0(dn->dn_free_txg); 207 ASSERT0(dn->dn_assigned_txg); 208 ASSERT0(dn->dn_dirty_txg); 209 ASSERT0(dn->dn_dirtyctx); 210 ASSERT3P(dn->dn_dirtyctx_firstset, ==, NULL); 211 ASSERT3P(dn->dn_bonus, ==, NULL); 212 ASSERT(!dn->dn_have_spill); 213 ASSERT3P(dn->dn_zio, ==, NULL); 214 ASSERT0(dn->dn_oldused); 215 ASSERT0(dn->dn_oldflags); 216 ASSERT0(dn->dn_olduid); 217 ASSERT0(dn->dn_oldgid); 218 ASSERT0(dn->dn_oldprojid); 219 ASSERT0(dn->dn_newuid); 220 ASSERT0(dn->dn_newgid); 221 ASSERT0(dn->dn_newprojid); 222 ASSERT0(dn->dn_id_flags); 223 224 ASSERT0(dn->dn_dbufs_count); 225 avl_destroy(&dn->dn_dbufs); 226 } 227 228 void 229 dnode_init(void) 230 { 231 ASSERT(dnode_cache == NULL); 232 dnode_cache = kmem_cache_create("dnode_t", sizeof (dnode_t), 233 0, dnode_cons, dnode_dest, NULL, NULL, NULL, 0); 234 kmem_cache_set_move(dnode_cache, dnode_move); 235 236 dnode_ksp = kstat_create("zfs", 0, "dnodestats", "misc", 237 KSTAT_TYPE_NAMED, sizeof (dnode_stats) / sizeof (kstat_named_t), 238 KSTAT_FLAG_VIRTUAL); 239 if (dnode_ksp != NULL) { 240 dnode_ksp->ks_data = &dnode_stats; 241 kstat_install(dnode_ksp); 242 } 243 } 244 245 void 246 dnode_fini(void) 247 { 248 if (dnode_ksp != NULL) { 249 kstat_delete(dnode_ksp); 250 dnode_ksp = NULL; 251 } 252 253 kmem_cache_destroy(dnode_cache); 254 dnode_cache = NULL; 255 } 256 257 258 #ifdef ZFS_DEBUG 259 void 260 dnode_verify(dnode_t *dn) 261 { 262 int drop_struct_lock = FALSE; 263 264 ASSERT(dn->dn_phys); 265 ASSERT(dn->dn_objset); 266 ASSERT(dn->dn_handle->dnh_dnode == dn); 267 268 ASSERT(DMU_OT_IS_VALID(dn->dn_phys->dn_type)); 269 270 if (!(zfs_flags & ZFS_DEBUG_DNODE_VERIFY)) 271 return; 272 273 if (!RW_WRITE_HELD(&dn->dn_struct_rwlock)) { 274 rw_enter(&dn->dn_struct_rwlock, RW_READER); 275 drop_struct_lock = TRUE; 276 } 277 if (dn->dn_phys->dn_type != DMU_OT_NONE || dn->dn_allocated_txg != 0) { 278 int i; 279 int max_bonuslen = DN_SLOTS_TO_BONUSLEN(dn->dn_num_slots); 280 ASSERT3U(dn->dn_indblkshift, <=, SPA_MAXBLOCKSHIFT); 281 if (dn->dn_datablkshift) { 282 ASSERT3U(dn->dn_datablkshift, >=, SPA_MINBLOCKSHIFT); 283 ASSERT3U(dn->dn_datablkshift, <=, SPA_MAXBLOCKSHIFT); 284 ASSERT3U(1<<dn->dn_datablkshift, ==, dn->dn_datablksz); 285 } 286 ASSERT3U(dn->dn_nlevels, <=, 30); 287 ASSERT(DMU_OT_IS_VALID(dn->dn_type)); 288 ASSERT3U(dn->dn_nblkptr, >=, 1); 289 ASSERT3U(dn->dn_nblkptr, <=, DN_MAX_NBLKPTR); 290 ASSERT3U(dn->dn_bonuslen, <=, max_bonuslen); 291 ASSERT3U(dn->dn_datablksz, ==, 292 dn->dn_datablkszsec << SPA_MINBLOCKSHIFT); 293 ASSERT3U(ISP2(dn->dn_datablksz), ==, dn->dn_datablkshift != 0); 294 ASSERT3U((dn->dn_nblkptr - 1) * sizeof (blkptr_t) + 295 dn->dn_bonuslen, <=, max_bonuslen); 296 for (i = 0; i < TXG_SIZE; i++) { 297 ASSERT3U(dn->dn_next_nlevels[i], <=, dn->dn_nlevels); 298 } 299 } 300 if (dn->dn_phys->dn_type != DMU_OT_NONE) 301 ASSERT3U(dn->dn_phys->dn_nlevels, <=, dn->dn_nlevels); 302 ASSERT(DMU_OBJECT_IS_SPECIAL(dn->dn_object) || dn->dn_dbuf != NULL); 303 if (dn->dn_dbuf != NULL) { 304 ASSERT3P(dn->dn_phys, ==, 305 (dnode_phys_t *)dn->dn_dbuf->db.db_data + 306 (dn->dn_object % (dn->dn_dbuf->db.db_size >> DNODE_SHIFT))); 307 } 308 if (drop_struct_lock) 309 rw_exit(&dn->dn_struct_rwlock); 310 } 311 #endif 312 313 void 314 dnode_byteswap(dnode_phys_t *dnp) 315 { 316 uint64_t *buf64 = (void*)&dnp->dn_blkptr; 317 int i; 318 319 if (dnp->dn_type == DMU_OT_NONE) { 320 bzero(dnp, sizeof (dnode_phys_t)); 321 return; 322 } 323 324 dnp->dn_datablkszsec = BSWAP_16(dnp->dn_datablkszsec); 325 dnp->dn_bonuslen = BSWAP_16(dnp->dn_bonuslen); 326 dnp->dn_extra_slots = BSWAP_8(dnp->dn_extra_slots); 327 dnp->dn_maxblkid = BSWAP_64(dnp->dn_maxblkid); 328 dnp->dn_used = BSWAP_64(dnp->dn_used); 329 330 /* 331 * dn_nblkptr is only one byte, so it's OK to read it in either 332 * byte order. We can't read dn_bouslen. 333 */ 334 ASSERT(dnp->dn_indblkshift <= SPA_MAXBLOCKSHIFT); 335 ASSERT(dnp->dn_nblkptr <= DN_MAX_NBLKPTR); 336 for (i = 0; i < dnp->dn_nblkptr * sizeof (blkptr_t)/8; i++) 337 buf64[i] = BSWAP_64(buf64[i]); 338 339 /* 340 * OK to check dn_bonuslen for zero, because it won't matter if 341 * we have the wrong byte order. This is necessary because the 342 * dnode dnode is smaller than a regular dnode. 343 */ 344 if (dnp->dn_bonuslen != 0) { 345 /* 346 * Note that the bonus length calculated here may be 347 * longer than the actual bonus buffer. This is because 348 * we always put the bonus buffer after the last block 349 * pointer (instead of packing it against the end of the 350 * dnode buffer). 351 */ 352 int off = (dnp->dn_nblkptr-1) * sizeof (blkptr_t); 353 int slots = dnp->dn_extra_slots + 1; 354 size_t len = DN_SLOTS_TO_BONUSLEN(slots) - off; 355 dmu_object_byteswap_t byteswap; 356 ASSERT(DMU_OT_IS_VALID(dnp->dn_bonustype)); 357 byteswap = DMU_OT_BYTESWAP(dnp->dn_bonustype); 358 dmu_ot_byteswap[byteswap].ob_func(dnp->dn_bonus + off, len); 359 } 360 361 /* Swap SPILL block if we have one */ 362 if (dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) 363 byteswap_uint64_array(DN_SPILL_BLKPTR(dnp), sizeof (blkptr_t)); 364 } 365 366 void 367 dnode_buf_byteswap(void *vbuf, size_t size) 368 { 369 int i = 0; 370 371 ASSERT3U(sizeof (dnode_phys_t), ==, (1<<DNODE_SHIFT)); 372 ASSERT((size & (sizeof (dnode_phys_t)-1)) == 0); 373 374 while (i < size) { 375 dnode_phys_t *dnp = (void *)(((char *)vbuf) + i); 376 dnode_byteswap(dnp); 377 378 i += DNODE_MIN_SIZE; 379 if (dnp->dn_type != DMU_OT_NONE) 380 i += dnp->dn_extra_slots * DNODE_MIN_SIZE; 381 } 382 } 383 384 void 385 dnode_setbonuslen(dnode_t *dn, int newsize, dmu_tx_t *tx) 386 { 387 ASSERT3U(zfs_refcount_count(&dn->dn_holds), >=, 1); 388 389 dnode_setdirty(dn, tx); 390 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 391 ASSERT3U(newsize, <=, DN_SLOTS_TO_BONUSLEN(dn->dn_num_slots) - 392 (dn->dn_nblkptr-1) * sizeof (blkptr_t)); 393 394 if (newsize < dn->dn_bonuslen) { 395 /* clear any data after the end of the new size */ 396 size_t diff = dn->dn_bonuslen - newsize; 397 char *data_end = ((char *)dn->dn_bonus->db.db_data) + newsize; 398 bzero(data_end, diff); 399 } 400 401 dn->dn_bonuslen = newsize; 402 if (newsize == 0) 403 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = DN_ZERO_BONUSLEN; 404 else 405 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = dn->dn_bonuslen; 406 rw_exit(&dn->dn_struct_rwlock); 407 } 408 409 void 410 dnode_setbonus_type(dnode_t *dn, dmu_object_type_t newtype, dmu_tx_t *tx) 411 { 412 ASSERT3U(zfs_refcount_count(&dn->dn_holds), >=, 1); 413 dnode_setdirty(dn, tx); 414 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 415 dn->dn_bonustype = newtype; 416 dn->dn_next_bonustype[tx->tx_txg & TXG_MASK] = dn->dn_bonustype; 417 rw_exit(&dn->dn_struct_rwlock); 418 } 419 420 void 421 dnode_rm_spill(dnode_t *dn, dmu_tx_t *tx) 422 { 423 ASSERT3U(zfs_refcount_count(&dn->dn_holds), >=, 1); 424 ASSERT(RW_WRITE_HELD(&dn->dn_struct_rwlock)); 425 dnode_setdirty(dn, tx); 426 dn->dn_rm_spillblk[tx->tx_txg & TXG_MASK] = DN_KILL_SPILLBLK; 427 dn->dn_have_spill = B_FALSE; 428 } 429 430 static void 431 dnode_setdblksz(dnode_t *dn, int size) 432 { 433 ASSERT0(P2PHASE(size, SPA_MINBLOCKSIZE)); 434 ASSERT3U(size, <=, SPA_MAXBLOCKSIZE); 435 ASSERT3U(size, >=, SPA_MINBLOCKSIZE); 436 ASSERT3U(size >> SPA_MINBLOCKSHIFT, <, 437 1<<(sizeof (dn->dn_phys->dn_datablkszsec) * 8)); 438 dn->dn_datablksz = size; 439 dn->dn_datablkszsec = size >> SPA_MINBLOCKSHIFT; 440 dn->dn_datablkshift = ISP2(size) ? highbit64(size - 1) : 0; 441 } 442 443 static dnode_t * 444 dnode_create(objset_t *os, dnode_phys_t *dnp, dmu_buf_impl_t *db, 445 uint64_t object, dnode_handle_t *dnh) 446 { 447 dnode_t *dn; 448 449 dn = kmem_cache_alloc(dnode_cache, KM_SLEEP); 450 dn->dn_moved = 0; 451 452 /* 453 * Defer setting dn_objset until the dnode is ready to be a candidate 454 * for the dnode_move() callback. 455 */ 456 dn->dn_object = object; 457 dn->dn_dbuf = db; 458 dn->dn_handle = dnh; 459 dn->dn_phys = dnp; 460 461 if (dnp->dn_datablkszsec) { 462 dnode_setdblksz(dn, dnp->dn_datablkszsec << SPA_MINBLOCKSHIFT); 463 } else { 464 dn->dn_datablksz = 0; 465 dn->dn_datablkszsec = 0; 466 dn->dn_datablkshift = 0; 467 } 468 dn->dn_indblkshift = dnp->dn_indblkshift; 469 dn->dn_nlevels = dnp->dn_nlevels; 470 dn->dn_type = dnp->dn_type; 471 dn->dn_nblkptr = dnp->dn_nblkptr; 472 dn->dn_checksum = dnp->dn_checksum; 473 dn->dn_compress = dnp->dn_compress; 474 dn->dn_bonustype = dnp->dn_bonustype; 475 dn->dn_bonuslen = dnp->dn_bonuslen; 476 dn->dn_num_slots = dnp->dn_extra_slots + 1; 477 dn->dn_maxblkid = dnp->dn_maxblkid; 478 dn->dn_have_spill = ((dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) != 0); 479 dn->dn_id_flags = 0; 480 481 dmu_zfetch_init(&dn->dn_zfetch, dn); 482 483 ASSERT(DMU_OT_IS_VALID(dn->dn_phys->dn_type)); 484 ASSERT(zrl_is_locked(&dnh->dnh_zrlock)); 485 ASSERT(!DN_SLOT_IS_PTR(dnh->dnh_dnode)); 486 487 mutex_enter(&os->os_lock); 488 489 /* 490 * Exclude special dnodes from os_dnodes so an empty os_dnodes 491 * signifies that the special dnodes have no references from 492 * their children (the entries in os_dnodes). This allows 493 * dnode_destroy() to easily determine if the last child has 494 * been removed and then complete eviction of the objset. 495 */ 496 if (!DMU_OBJECT_IS_SPECIAL(object)) 497 list_insert_head(&os->os_dnodes, dn); 498 membar_producer(); 499 500 /* 501 * Everything else must be valid before assigning dn_objset 502 * makes the dnode eligible for dnode_move(). 503 */ 504 dn->dn_objset = os; 505 506 dnh->dnh_dnode = dn; 507 mutex_exit(&os->os_lock); 508 509 arc_space_consume(sizeof (dnode_t), ARC_SPACE_DNODE); 510 511 return (dn); 512 } 513 514 /* 515 * Caller must be holding the dnode handle, which is released upon return. 516 */ 517 static void 518 dnode_destroy(dnode_t *dn) 519 { 520 objset_t *os = dn->dn_objset; 521 boolean_t complete_os_eviction = B_FALSE; 522 523 ASSERT((dn->dn_id_flags & DN_ID_NEW_EXIST) == 0); 524 525 mutex_enter(&os->os_lock); 526 POINTER_INVALIDATE(&dn->dn_objset); 527 if (!DMU_OBJECT_IS_SPECIAL(dn->dn_object)) { 528 list_remove(&os->os_dnodes, dn); 529 complete_os_eviction = 530 list_is_empty(&os->os_dnodes) && 531 list_link_active(&os->os_evicting_node); 532 } 533 mutex_exit(&os->os_lock); 534 535 /* the dnode can no longer move, so we can release the handle */ 536 if (!zrl_is_locked(&dn->dn_handle->dnh_zrlock)) 537 zrl_remove(&dn->dn_handle->dnh_zrlock); 538 539 dn->dn_allocated_txg = 0; 540 dn->dn_free_txg = 0; 541 dn->dn_assigned_txg = 0; 542 dn->dn_dirty_txg = 0; 543 544 dn->dn_dirtyctx = 0; 545 dn->dn_dirtyctx_firstset = NULL; 546 if (dn->dn_bonus != NULL) { 547 mutex_enter(&dn->dn_bonus->db_mtx); 548 dbuf_destroy(dn->dn_bonus); 549 dn->dn_bonus = NULL; 550 } 551 dn->dn_zio = NULL; 552 553 dn->dn_have_spill = B_FALSE; 554 dn->dn_oldused = 0; 555 dn->dn_oldflags = 0; 556 dn->dn_olduid = 0; 557 dn->dn_oldgid = 0; 558 dn->dn_oldprojid = ZFS_DEFAULT_PROJID; 559 dn->dn_newuid = 0; 560 dn->dn_newgid = 0; 561 dn->dn_newprojid = ZFS_DEFAULT_PROJID; 562 dn->dn_id_flags = 0; 563 564 dmu_zfetch_fini(&dn->dn_zfetch); 565 kmem_cache_free(dnode_cache, dn); 566 arc_space_return(sizeof (dnode_t), ARC_SPACE_DNODE); 567 568 if (complete_os_eviction) 569 dmu_objset_evict_done(os); 570 } 571 572 void 573 dnode_allocate(dnode_t *dn, dmu_object_type_t ot, int blocksize, int ibs, 574 dmu_object_type_t bonustype, int bonuslen, int dn_slots, dmu_tx_t *tx) 575 { 576 int i; 577 578 ASSERT3U(dn_slots, >, 0); 579 ASSERT3U(dn_slots << DNODE_SHIFT, <=, 580 spa_maxdnodesize(dmu_objset_spa(dn->dn_objset))); 581 ASSERT3U(blocksize, <=, 582 spa_maxblocksize(dmu_objset_spa(dn->dn_objset))); 583 if (blocksize == 0) 584 blocksize = 1 << zfs_default_bs; 585 else 586 blocksize = P2ROUNDUP(blocksize, SPA_MINBLOCKSIZE); 587 588 if (ibs == 0) 589 ibs = zfs_default_ibs; 590 591 ibs = MIN(MAX(ibs, DN_MIN_INDBLKSHIFT), DN_MAX_INDBLKSHIFT); 592 593 dprintf("os=%p obj=%llu txg=%llu blocksize=%d ibs=%d dn_slots=%d\n", 594 dn->dn_objset, (u_longlong_t)dn->dn_object, 595 (u_longlong_t)tx->tx_txg, blocksize, ibs, dn_slots); 596 DNODE_STAT_BUMP(dnode_allocate); 597 598 ASSERT(dn->dn_type == DMU_OT_NONE); 599 ASSERT(bcmp(dn->dn_phys, &dnode_phys_zero, sizeof (dnode_phys_t)) == 0); 600 ASSERT(dn->dn_phys->dn_type == DMU_OT_NONE); 601 ASSERT(ot != DMU_OT_NONE); 602 ASSERT(DMU_OT_IS_VALID(ot)); 603 ASSERT((bonustype == DMU_OT_NONE && bonuslen == 0) || 604 (bonustype == DMU_OT_SA && bonuslen == 0) || 605 (bonustype != DMU_OT_NONE && bonuslen != 0)); 606 ASSERT(DMU_OT_IS_VALID(bonustype)); 607 ASSERT3U(bonuslen, <=, DN_SLOTS_TO_BONUSLEN(dn_slots)); 608 ASSERT(dn->dn_type == DMU_OT_NONE); 609 ASSERT0(dn->dn_maxblkid); 610 ASSERT0(dn->dn_allocated_txg); 611 ASSERT0(dn->dn_assigned_txg); 612 ASSERT(zfs_refcount_is_zero(&dn->dn_tx_holds)); 613 ASSERT3U(zfs_refcount_count(&dn->dn_holds), <=, 1); 614 ASSERT(avl_is_empty(&dn->dn_dbufs)); 615 616 for (i = 0; i < TXG_SIZE; i++) { 617 ASSERT0(dn->dn_next_nblkptr[i]); 618 ASSERT0(dn->dn_next_nlevels[i]); 619 ASSERT0(dn->dn_next_indblkshift[i]); 620 ASSERT0(dn->dn_next_bonuslen[i]); 621 ASSERT0(dn->dn_next_bonustype[i]); 622 ASSERT0(dn->dn_rm_spillblk[i]); 623 ASSERT0(dn->dn_next_blksz[i]); 624 ASSERT0(dn->dn_next_maxblkid[i]); 625 ASSERT(!multilist_link_active(&dn->dn_dirty_link[i])); 626 ASSERT3P(list_head(&dn->dn_dirty_records[i]), ==, NULL); 627 ASSERT3P(dn->dn_free_ranges[i], ==, NULL); 628 } 629 630 dn->dn_type = ot; 631 dnode_setdblksz(dn, blocksize); 632 dn->dn_indblkshift = ibs; 633 dn->dn_nlevels = 1; 634 dn->dn_num_slots = dn_slots; 635 if (bonustype == DMU_OT_SA) /* Maximize bonus space for SA */ 636 dn->dn_nblkptr = 1; 637 else { 638 dn->dn_nblkptr = MIN(DN_MAX_NBLKPTR, 639 1 + ((DN_SLOTS_TO_BONUSLEN(dn_slots) - bonuslen) >> 640 SPA_BLKPTRSHIFT)); 641 } 642 643 dn->dn_bonustype = bonustype; 644 dn->dn_bonuslen = bonuslen; 645 dn->dn_checksum = ZIO_CHECKSUM_INHERIT; 646 dn->dn_compress = ZIO_COMPRESS_INHERIT; 647 dn->dn_dirtyctx = 0; 648 649 dn->dn_free_txg = 0; 650 dn->dn_dirtyctx_firstset = NULL; 651 dn->dn_dirty_txg = 0; 652 653 dn->dn_allocated_txg = tx->tx_txg; 654 dn->dn_id_flags = 0; 655 656 dnode_setdirty(dn, tx); 657 dn->dn_next_indblkshift[tx->tx_txg & TXG_MASK] = ibs; 658 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = dn->dn_bonuslen; 659 dn->dn_next_bonustype[tx->tx_txg & TXG_MASK] = dn->dn_bonustype; 660 dn->dn_next_blksz[tx->tx_txg & TXG_MASK] = dn->dn_datablksz; 661 } 662 663 void 664 dnode_reallocate(dnode_t *dn, dmu_object_type_t ot, int blocksize, 665 dmu_object_type_t bonustype, int bonuslen, int dn_slots, 666 boolean_t keep_spill, dmu_tx_t *tx) 667 { 668 int nblkptr; 669 670 ASSERT3U(blocksize, >=, SPA_MINBLOCKSIZE); 671 ASSERT3U(blocksize, <=, 672 spa_maxblocksize(dmu_objset_spa(dn->dn_objset))); 673 ASSERT0(blocksize % SPA_MINBLOCKSIZE); 674 ASSERT(dn->dn_object != DMU_META_DNODE_OBJECT || dmu_tx_private_ok(tx)); 675 ASSERT(tx->tx_txg != 0); 676 ASSERT((bonustype == DMU_OT_NONE && bonuslen == 0) || 677 (bonustype != DMU_OT_NONE && bonuslen != 0) || 678 (bonustype == DMU_OT_SA && bonuslen == 0)); 679 ASSERT(DMU_OT_IS_VALID(bonustype)); 680 ASSERT3U(bonuslen, <=, 681 DN_BONUS_SIZE(spa_maxdnodesize(dmu_objset_spa(dn->dn_objset)))); 682 ASSERT3U(bonuslen, <=, DN_BONUS_SIZE(dn_slots << DNODE_SHIFT)); 683 684 dnode_free_interior_slots(dn); 685 DNODE_STAT_BUMP(dnode_reallocate); 686 687 /* clean up any unreferenced dbufs */ 688 dnode_evict_dbufs(dn); 689 690 dn->dn_id_flags = 0; 691 692 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 693 dnode_setdirty(dn, tx); 694 if (dn->dn_datablksz != blocksize) { 695 /* change blocksize */ 696 ASSERT0(dn->dn_maxblkid); 697 ASSERT(BP_IS_HOLE(&dn->dn_phys->dn_blkptr[0]) || 698 dnode_block_freed(dn, 0)); 699 700 dnode_setdblksz(dn, blocksize); 701 dn->dn_next_blksz[tx->tx_txg & TXG_MASK] = blocksize; 702 } 703 if (dn->dn_bonuslen != bonuslen) 704 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = bonuslen; 705 706 if (bonustype == DMU_OT_SA) /* Maximize bonus space for SA */ 707 nblkptr = 1; 708 else 709 nblkptr = MIN(DN_MAX_NBLKPTR, 710 1 + ((DN_SLOTS_TO_BONUSLEN(dn_slots) - bonuslen) >> 711 SPA_BLKPTRSHIFT)); 712 if (dn->dn_bonustype != bonustype) 713 dn->dn_next_bonustype[tx->tx_txg & TXG_MASK] = bonustype; 714 if (dn->dn_nblkptr != nblkptr) 715 dn->dn_next_nblkptr[tx->tx_txg & TXG_MASK] = nblkptr; 716 if (dn->dn_phys->dn_flags & DNODE_FLAG_SPILL_BLKPTR && !keep_spill) { 717 dbuf_rm_spill(dn, tx); 718 dnode_rm_spill(dn, tx); 719 } 720 721 rw_exit(&dn->dn_struct_rwlock); 722 723 /* change type */ 724 dn->dn_type = ot; 725 726 /* change bonus size and type */ 727 mutex_enter(&dn->dn_mtx); 728 dn->dn_bonustype = bonustype; 729 dn->dn_bonuslen = bonuslen; 730 dn->dn_num_slots = dn_slots; 731 dn->dn_nblkptr = nblkptr; 732 dn->dn_checksum = ZIO_CHECKSUM_INHERIT; 733 dn->dn_compress = ZIO_COMPRESS_INHERIT; 734 ASSERT3U(dn->dn_nblkptr, <=, DN_MAX_NBLKPTR); 735 736 /* fix up the bonus db_size */ 737 if (dn->dn_bonus) { 738 dn->dn_bonus->db.db_size = 739 DN_SLOTS_TO_BONUSLEN(dn->dn_num_slots) - 740 (dn->dn_nblkptr-1) * sizeof (blkptr_t); 741 ASSERT(dn->dn_bonuslen <= dn->dn_bonus->db.db_size); 742 } 743 744 dn->dn_allocated_txg = tx->tx_txg; 745 mutex_exit(&dn->dn_mtx); 746 } 747 748 #ifdef _KERNEL 749 static void 750 dnode_move_impl(dnode_t *odn, dnode_t *ndn) 751 { 752 int i; 753 754 ASSERT(!RW_LOCK_HELD(&odn->dn_struct_rwlock)); 755 ASSERT(MUTEX_NOT_HELD(&odn->dn_mtx)); 756 ASSERT(MUTEX_NOT_HELD(&odn->dn_dbufs_mtx)); 757 758 /* Copy fields. */ 759 ndn->dn_objset = odn->dn_objset; 760 ndn->dn_object = odn->dn_object; 761 ndn->dn_dbuf = odn->dn_dbuf; 762 ndn->dn_handle = odn->dn_handle; 763 ndn->dn_phys = odn->dn_phys; 764 ndn->dn_type = odn->dn_type; 765 ndn->dn_bonuslen = odn->dn_bonuslen; 766 ndn->dn_bonustype = odn->dn_bonustype; 767 ndn->dn_nblkptr = odn->dn_nblkptr; 768 ndn->dn_checksum = odn->dn_checksum; 769 ndn->dn_compress = odn->dn_compress; 770 ndn->dn_nlevels = odn->dn_nlevels; 771 ndn->dn_indblkshift = odn->dn_indblkshift; 772 ndn->dn_datablkshift = odn->dn_datablkshift; 773 ndn->dn_datablkszsec = odn->dn_datablkszsec; 774 ndn->dn_datablksz = odn->dn_datablksz; 775 ndn->dn_maxblkid = odn->dn_maxblkid; 776 ndn->dn_num_slots = odn->dn_num_slots; 777 bcopy(&odn->dn_next_type[0], &ndn->dn_next_type[0], 778 sizeof (odn->dn_next_type)); 779 bcopy(&odn->dn_next_nblkptr[0], &ndn->dn_next_nblkptr[0], 780 sizeof (odn->dn_next_nblkptr)); 781 bcopy(&odn->dn_next_nlevels[0], &ndn->dn_next_nlevels[0], 782 sizeof (odn->dn_next_nlevels)); 783 bcopy(&odn->dn_next_indblkshift[0], &ndn->dn_next_indblkshift[0], 784 sizeof (odn->dn_next_indblkshift)); 785 bcopy(&odn->dn_next_bonustype[0], &ndn->dn_next_bonustype[0], 786 sizeof (odn->dn_next_bonustype)); 787 bcopy(&odn->dn_rm_spillblk[0], &ndn->dn_rm_spillblk[0], 788 sizeof (odn->dn_rm_spillblk)); 789 bcopy(&odn->dn_next_bonuslen[0], &ndn->dn_next_bonuslen[0], 790 sizeof (odn->dn_next_bonuslen)); 791 bcopy(&odn->dn_next_blksz[0], &ndn->dn_next_blksz[0], 792 sizeof (odn->dn_next_blksz)); 793 bcopy(&odn->dn_next_maxblkid[0], &ndn->dn_next_maxblkid[0], 794 sizeof (odn->dn_next_maxblkid)); 795 for (i = 0; i < TXG_SIZE; i++) { 796 list_move_tail(&ndn->dn_dirty_records[i], 797 &odn->dn_dirty_records[i]); 798 } 799 bcopy(&odn->dn_free_ranges[0], &ndn->dn_free_ranges[0], 800 sizeof (odn->dn_free_ranges)); 801 ndn->dn_allocated_txg = odn->dn_allocated_txg; 802 ndn->dn_free_txg = odn->dn_free_txg; 803 ndn->dn_assigned_txg = odn->dn_assigned_txg; 804 ndn->dn_dirty_txg = odn->dn_dirty_txg; 805 ndn->dn_dirtyctx = odn->dn_dirtyctx; 806 ndn->dn_dirtyctx_firstset = odn->dn_dirtyctx_firstset; 807 ASSERT(zfs_refcount_count(&odn->dn_tx_holds) == 0); 808 zfs_refcount_transfer(&ndn->dn_holds, &odn->dn_holds); 809 ASSERT(avl_is_empty(&ndn->dn_dbufs)); 810 avl_swap(&ndn->dn_dbufs, &odn->dn_dbufs); 811 ndn->dn_dbufs_count = odn->dn_dbufs_count; 812 ndn->dn_bonus = odn->dn_bonus; 813 ndn->dn_have_spill = odn->dn_have_spill; 814 ndn->dn_zio = odn->dn_zio; 815 ndn->dn_oldused = odn->dn_oldused; 816 ndn->dn_oldflags = odn->dn_oldflags; 817 ndn->dn_olduid = odn->dn_olduid; 818 ndn->dn_oldgid = odn->dn_oldgid; 819 ndn->dn_oldprojid = odn->dn_oldprojid; 820 ndn->dn_newuid = odn->dn_newuid; 821 ndn->dn_newgid = odn->dn_newgid; 822 ndn->dn_newprojid = odn->dn_newprojid; 823 ndn->dn_id_flags = odn->dn_id_flags; 824 dmu_zfetch_init(&ndn->dn_zfetch, ndn); 825 826 /* 827 * Update back pointers. Updating the handle fixes the back pointer of 828 * every descendant dbuf as well as the bonus dbuf. 829 */ 830 ASSERT(ndn->dn_handle->dnh_dnode == odn); 831 ndn->dn_handle->dnh_dnode = ndn; 832 833 /* 834 * Invalidate the original dnode by clearing all of its back pointers. 835 */ 836 odn->dn_dbuf = NULL; 837 odn->dn_handle = NULL; 838 avl_create(&odn->dn_dbufs, dbuf_compare, sizeof (dmu_buf_impl_t), 839 offsetof(dmu_buf_impl_t, db_link)); 840 odn->dn_dbufs_count = 0; 841 odn->dn_bonus = NULL; 842 dmu_zfetch_fini(&odn->dn_zfetch); 843 844 /* 845 * Set the low bit of the objset pointer to ensure that dnode_move() 846 * recognizes the dnode as invalid in any subsequent callback. 847 */ 848 POINTER_INVALIDATE(&odn->dn_objset); 849 850 /* 851 * Satisfy the destructor. 852 */ 853 for (i = 0; i < TXG_SIZE; i++) { 854 list_create(&odn->dn_dirty_records[i], 855 sizeof (dbuf_dirty_record_t), 856 offsetof(dbuf_dirty_record_t, dr_dirty_node)); 857 odn->dn_free_ranges[i] = NULL; 858 odn->dn_next_nlevels[i] = 0; 859 odn->dn_next_indblkshift[i] = 0; 860 odn->dn_next_bonustype[i] = 0; 861 odn->dn_rm_spillblk[i] = 0; 862 odn->dn_next_bonuslen[i] = 0; 863 odn->dn_next_blksz[i] = 0; 864 } 865 odn->dn_allocated_txg = 0; 866 odn->dn_free_txg = 0; 867 odn->dn_assigned_txg = 0; 868 odn->dn_dirty_txg = 0; 869 odn->dn_dirtyctx = 0; 870 odn->dn_dirtyctx_firstset = NULL; 871 odn->dn_have_spill = B_FALSE; 872 odn->dn_zio = NULL; 873 odn->dn_oldused = 0; 874 odn->dn_oldflags = 0; 875 odn->dn_olduid = 0; 876 odn->dn_oldgid = 0; 877 odn->dn_oldprojid = ZFS_DEFAULT_PROJID; 878 odn->dn_newuid = 0; 879 odn->dn_newgid = 0; 880 odn->dn_newprojid = ZFS_DEFAULT_PROJID; 881 odn->dn_id_flags = 0; 882 883 /* 884 * Mark the dnode. 885 */ 886 ndn->dn_moved = 1; 887 odn->dn_moved = (uint8_t)-1; 888 } 889 890 static kmem_cbrc_t 891 dnode_move(void *buf, void *newbuf, size_t size, void *arg) 892 { 893 dnode_t *odn = buf, *ndn = newbuf; 894 objset_t *os; 895 int64_t refcount; 896 uint32_t dbufs; 897 898 /* 899 * The dnode is on the objset's list of known dnodes if the objset 900 * pointer is valid. We set the low bit of the objset pointer when 901 * freeing the dnode to invalidate it, and the memory patterns written 902 * by kmem (baddcafe and deadbeef) set at least one of the two low bits. 903 * A newly created dnode sets the objset pointer last of all to indicate 904 * that the dnode is known and in a valid state to be moved by this 905 * function. 906 */ 907 os = odn->dn_objset; 908 if (!POINTER_IS_VALID(os)) { 909 DNODE_STAT_BUMP(dnode_move_invalid); 910 return (KMEM_CBRC_DONT_KNOW); 911 } 912 913 /* 914 * Ensure that the objset does not go away during the move. 915 */ 916 rw_enter(&os_lock, RW_WRITER); 917 if (os != odn->dn_objset) { 918 rw_exit(&os_lock); 919 DNODE_STAT_BUMP(dnode_move_recheck1); 920 return (KMEM_CBRC_DONT_KNOW); 921 } 922 923 /* 924 * If the dnode is still valid, then so is the objset. We know that no 925 * valid objset can be freed while we hold os_lock, so we can safely 926 * ensure that the objset remains in use. 927 */ 928 mutex_enter(&os->os_lock); 929 930 /* 931 * Recheck the objset pointer in case the dnode was removed just before 932 * acquiring the lock. 933 */ 934 if (os != odn->dn_objset) { 935 mutex_exit(&os->os_lock); 936 rw_exit(&os_lock); 937 DNODE_STAT_BUMP(dnode_move_recheck2); 938 return (KMEM_CBRC_DONT_KNOW); 939 } 940 941 /* 942 * At this point we know that as long as we hold os->os_lock, the dnode 943 * cannot be freed and fields within the dnode can be safely accessed. 944 * The objset listing this dnode cannot go away as long as this dnode is 945 * on its list. 946 */ 947 rw_exit(&os_lock); 948 if (DMU_OBJECT_IS_SPECIAL(odn->dn_object)) { 949 mutex_exit(&os->os_lock); 950 DNODE_STAT_BUMP(dnode_move_special); 951 return (KMEM_CBRC_NO); 952 } 953 ASSERT(odn->dn_dbuf != NULL); /* only "special" dnodes have no parent */ 954 955 /* 956 * Lock the dnode handle to prevent the dnode from obtaining any new 957 * holds. This also prevents the descendant dbufs and the bonus dbuf 958 * from accessing the dnode, so that we can discount their holds. The 959 * handle is safe to access because we know that while the dnode cannot 960 * go away, neither can its handle. Once we hold dnh_zrlock, we can 961 * safely move any dnode referenced only by dbufs. 962 */ 963 if (!zrl_tryenter(&odn->dn_handle->dnh_zrlock)) { 964 mutex_exit(&os->os_lock); 965 DNODE_STAT_BUMP(dnode_move_handle); 966 return (KMEM_CBRC_LATER); 967 } 968 969 /* 970 * Ensure a consistent view of the dnode's holds and the dnode's dbufs. 971 * We need to guarantee that there is a hold for every dbuf in order to 972 * determine whether the dnode is actively referenced. Falsely matching 973 * a dbuf to an active hold would lead to an unsafe move. It's possible 974 * that a thread already having an active dnode hold is about to add a 975 * dbuf, and we can't compare hold and dbuf counts while the add is in 976 * progress. 977 */ 978 if (!rw_tryenter(&odn->dn_struct_rwlock, RW_WRITER)) { 979 zrl_exit(&odn->dn_handle->dnh_zrlock); 980 mutex_exit(&os->os_lock); 981 DNODE_STAT_BUMP(dnode_move_rwlock); 982 return (KMEM_CBRC_LATER); 983 } 984 985 /* 986 * A dbuf may be removed (evicted) without an active dnode hold. In that 987 * case, the dbuf count is decremented under the handle lock before the 988 * dbuf's hold is released. This order ensures that if we count the hold 989 * after the dbuf is removed but before its hold is released, we will 990 * treat the unmatched hold as active and exit safely. If we count the 991 * hold before the dbuf is removed, the hold is discounted, and the 992 * removal is blocked until the move completes. 993 */ 994 refcount = zfs_refcount_count(&odn->dn_holds); 995 ASSERT(refcount >= 0); 996 dbufs = DN_DBUFS_COUNT(odn); 997 998 /* We can't have more dbufs than dnode holds. */ 999 ASSERT3U(dbufs, <=, refcount); 1000 DTRACE_PROBE3(dnode__move, dnode_t *, odn, int64_t, refcount, 1001 uint32_t, dbufs); 1002 1003 if (refcount > dbufs) { 1004 rw_exit(&odn->dn_struct_rwlock); 1005 zrl_exit(&odn->dn_handle->dnh_zrlock); 1006 mutex_exit(&os->os_lock); 1007 DNODE_STAT_BUMP(dnode_move_active); 1008 return (KMEM_CBRC_LATER); 1009 } 1010 1011 rw_exit(&odn->dn_struct_rwlock); 1012 1013 /* 1014 * At this point we know that anyone with a hold on the dnode is not 1015 * actively referencing it. The dnode is known and in a valid state to 1016 * move. We're holding the locks needed to execute the critical section. 1017 */ 1018 dnode_move_impl(odn, ndn); 1019 1020 list_link_replace(&odn->dn_link, &ndn->dn_link); 1021 /* If the dnode was safe to move, the refcount cannot have changed. */ 1022 ASSERT(refcount == zfs_refcount_count(&ndn->dn_holds)); 1023 ASSERT(dbufs == DN_DBUFS_COUNT(ndn)); 1024 zrl_exit(&ndn->dn_handle->dnh_zrlock); /* handle has moved */ 1025 mutex_exit(&os->os_lock); 1026 1027 return (KMEM_CBRC_YES); 1028 } 1029 #endif /* _KERNEL */ 1030 1031 static void 1032 dnode_slots_hold(dnode_children_t *children, int idx, int slots) 1033 { 1034 ASSERT3S(idx + slots, <=, DNODES_PER_BLOCK); 1035 1036 for (int i = idx; i < idx + slots; i++) { 1037 dnode_handle_t *dnh = &children->dnc_children[i]; 1038 zrl_add(&dnh->dnh_zrlock); 1039 } 1040 } 1041 1042 static void 1043 dnode_slots_rele(dnode_children_t *children, int idx, int slots) 1044 { 1045 ASSERT3S(idx + slots, <=, DNODES_PER_BLOCK); 1046 1047 for (int i = idx; i < idx + slots; i++) { 1048 dnode_handle_t *dnh = &children->dnc_children[i]; 1049 1050 if (zrl_is_locked(&dnh->dnh_zrlock)) 1051 zrl_exit(&dnh->dnh_zrlock); 1052 else 1053 zrl_remove(&dnh->dnh_zrlock); 1054 } 1055 } 1056 1057 static int 1058 dnode_slots_tryenter(dnode_children_t *children, int idx, int slots) 1059 { 1060 ASSERT3S(idx + slots, <=, DNODES_PER_BLOCK); 1061 1062 for (int i = idx; i < idx + slots; i++) { 1063 dnode_handle_t *dnh = &children->dnc_children[i]; 1064 1065 if (!zrl_tryenter(&dnh->dnh_zrlock)) { 1066 for (int j = idx; j < i; j++) { 1067 dnh = &children->dnc_children[j]; 1068 zrl_exit(&dnh->dnh_zrlock); 1069 } 1070 1071 return (0); 1072 } 1073 } 1074 1075 return (1); 1076 } 1077 1078 static void 1079 dnode_set_slots(dnode_children_t *children, int idx, int slots, void *ptr) 1080 { 1081 ASSERT3S(idx + slots, <=, DNODES_PER_BLOCK); 1082 1083 for (int i = idx; i < idx + slots; i++) { 1084 dnode_handle_t *dnh = &children->dnc_children[i]; 1085 dnh->dnh_dnode = ptr; 1086 } 1087 } 1088 1089 static boolean_t 1090 dnode_check_slots_free(dnode_children_t *children, int idx, int slots) 1091 { 1092 ASSERT3S(idx + slots, <=, DNODES_PER_BLOCK); 1093 1094 /* 1095 * If all dnode slots are either already free or 1096 * evictable return B_TRUE. 1097 */ 1098 for (int i = idx; i < idx + slots; i++) { 1099 dnode_handle_t *dnh = &children->dnc_children[i]; 1100 dnode_t *dn = dnh->dnh_dnode; 1101 1102 if (dn == DN_SLOT_FREE) { 1103 continue; 1104 } else if (DN_SLOT_IS_PTR(dn)) { 1105 mutex_enter(&dn->dn_mtx); 1106 boolean_t can_free = (dn->dn_type == DMU_OT_NONE && 1107 zfs_refcount_is_zero(&dn->dn_holds) && 1108 !DNODE_IS_DIRTY(dn)); 1109 mutex_exit(&dn->dn_mtx); 1110 1111 if (!can_free) 1112 return (B_FALSE); 1113 else 1114 continue; 1115 } else { 1116 return (B_FALSE); 1117 } 1118 } 1119 1120 return (B_TRUE); 1121 } 1122 1123 static void 1124 dnode_reclaim_slots(dnode_children_t *children, int idx, int slots) 1125 { 1126 ASSERT3S(idx + slots, <=, DNODES_PER_BLOCK); 1127 1128 for (int i = idx; i < idx + slots; i++) { 1129 dnode_handle_t *dnh = &children->dnc_children[i]; 1130 1131 ASSERT(zrl_is_locked(&dnh->dnh_zrlock)); 1132 1133 if (DN_SLOT_IS_PTR(dnh->dnh_dnode)) { 1134 ASSERT3S(dnh->dnh_dnode->dn_type, ==, DMU_OT_NONE); 1135 dnode_destroy(dnh->dnh_dnode); 1136 dnh->dnh_dnode = DN_SLOT_FREE; 1137 } 1138 } 1139 } 1140 1141 void 1142 dnode_free_interior_slots(dnode_t *dn) 1143 { 1144 dnode_children_t *children = dmu_buf_get_user(&dn->dn_dbuf->db); 1145 int epb = dn->dn_dbuf->db.db_size >> DNODE_SHIFT; 1146 int idx = (dn->dn_object & (epb - 1)) + 1; 1147 int slots = dn->dn_num_slots - 1; 1148 1149 if (slots == 0) 1150 return; 1151 1152 ASSERT3S(idx + slots, <=, DNODES_PER_BLOCK); 1153 1154 while (!dnode_slots_tryenter(children, idx, slots)) { 1155 DNODE_STAT_BUMP(dnode_free_interior_lock_retry); 1156 cond_resched(); 1157 } 1158 1159 dnode_set_slots(children, idx, slots, DN_SLOT_FREE); 1160 dnode_slots_rele(children, idx, slots); 1161 } 1162 1163 void 1164 dnode_special_close(dnode_handle_t *dnh) 1165 { 1166 dnode_t *dn = dnh->dnh_dnode; 1167 1168 /* 1169 * Ensure dnode_rele_and_unlock() has released dn_mtx, after final 1170 * zfs_refcount_remove() 1171 */ 1172 mutex_enter(&dn->dn_mtx); 1173 if (zfs_refcount_count(&dn->dn_holds) > 0) 1174 cv_wait(&dn->dn_nodnholds, &dn->dn_mtx); 1175 mutex_exit(&dn->dn_mtx); 1176 ASSERT3U(zfs_refcount_count(&dn->dn_holds), ==, 0); 1177 1178 ASSERT(dn->dn_dbuf == NULL || 1179 dmu_buf_get_user(&dn->dn_dbuf->db) == NULL); 1180 zrl_add(&dnh->dnh_zrlock); 1181 dnode_destroy(dn); /* implicit zrl_remove() */ 1182 zrl_destroy(&dnh->dnh_zrlock); 1183 dnh->dnh_dnode = NULL; 1184 } 1185 1186 void 1187 dnode_special_open(objset_t *os, dnode_phys_t *dnp, uint64_t object, 1188 dnode_handle_t *dnh) 1189 { 1190 dnode_t *dn; 1191 1192 zrl_init(&dnh->dnh_zrlock); 1193 VERIFY3U(1, ==, zrl_tryenter(&dnh->dnh_zrlock)); 1194 1195 dn = dnode_create(os, dnp, NULL, object, dnh); 1196 DNODE_VERIFY(dn); 1197 1198 zrl_exit(&dnh->dnh_zrlock); 1199 } 1200 1201 static void 1202 dnode_buf_evict_async(void *dbu) 1203 { 1204 dnode_children_t *dnc = dbu; 1205 1206 DNODE_STAT_BUMP(dnode_buf_evict); 1207 1208 for (int i = 0; i < dnc->dnc_count; i++) { 1209 dnode_handle_t *dnh = &dnc->dnc_children[i]; 1210 dnode_t *dn; 1211 1212 /* 1213 * The dnode handle lock guards against the dnode moving to 1214 * another valid address, so there is no need here to guard 1215 * against changes to or from NULL. 1216 */ 1217 if (!DN_SLOT_IS_PTR(dnh->dnh_dnode)) { 1218 zrl_destroy(&dnh->dnh_zrlock); 1219 dnh->dnh_dnode = DN_SLOT_UNINIT; 1220 continue; 1221 } 1222 1223 zrl_add(&dnh->dnh_zrlock); 1224 dn = dnh->dnh_dnode; 1225 /* 1226 * If there are holds on this dnode, then there should 1227 * be holds on the dnode's containing dbuf as well; thus 1228 * it wouldn't be eligible for eviction and this function 1229 * would not have been called. 1230 */ 1231 ASSERT(zfs_refcount_is_zero(&dn->dn_holds)); 1232 ASSERT(zfs_refcount_is_zero(&dn->dn_tx_holds)); 1233 1234 dnode_destroy(dn); /* implicit zrl_remove() for first slot */ 1235 zrl_destroy(&dnh->dnh_zrlock); 1236 dnh->dnh_dnode = DN_SLOT_UNINIT; 1237 } 1238 kmem_free(dnc, sizeof (dnode_children_t) + 1239 dnc->dnc_count * sizeof (dnode_handle_t)); 1240 } 1241 1242 /* 1243 * When the DNODE_MUST_BE_FREE flag is set, the "slots" parameter is used 1244 * to ensure the hole at the specified object offset is large enough to 1245 * hold the dnode being created. The slots parameter is also used to ensure 1246 * a dnode does not span multiple dnode blocks. In both of these cases, if 1247 * a failure occurs, ENOSPC is returned. Keep in mind, these failure cases 1248 * are only possible when using DNODE_MUST_BE_FREE. 1249 * 1250 * If the DNODE_MUST_BE_ALLOCATED flag is set, "slots" must be 0. 1251 * dnode_hold_impl() will check if the requested dnode is already consumed 1252 * as an extra dnode slot by an large dnode, in which case it returns 1253 * ENOENT. 1254 * 1255 * If the DNODE_DRY_RUN flag is set, we don't actually hold the dnode, just 1256 * return whether the hold would succeed or not. tag and dnp should set to 1257 * NULL in this case. 1258 * 1259 * errors: 1260 * EINVAL - Invalid object number or flags. 1261 * ENOSPC - Hole too small to fulfill "slots" request (DNODE_MUST_BE_FREE) 1262 * EEXIST - Refers to an allocated dnode (DNODE_MUST_BE_FREE) 1263 * - Refers to a freeing dnode (DNODE_MUST_BE_FREE) 1264 * - Refers to an interior dnode slot (DNODE_MUST_BE_ALLOCATED) 1265 * ENOENT - The requested dnode is not allocated (DNODE_MUST_BE_ALLOCATED) 1266 * - The requested dnode is being freed (DNODE_MUST_BE_ALLOCATED) 1267 * EIO - I/O error when reading the meta dnode dbuf. 1268 * 1269 * succeeds even for free dnodes. 1270 */ 1271 int 1272 dnode_hold_impl(objset_t *os, uint64_t object, int flag, int slots, 1273 void *tag, dnode_t **dnp) 1274 { 1275 int epb, idx, err; 1276 int drop_struct_lock = FALSE; 1277 int type; 1278 uint64_t blk; 1279 dnode_t *mdn, *dn; 1280 dmu_buf_impl_t *db; 1281 dnode_children_t *dnc; 1282 dnode_phys_t *dn_block; 1283 dnode_handle_t *dnh; 1284 1285 ASSERT(!(flag & DNODE_MUST_BE_ALLOCATED) || (slots == 0)); 1286 ASSERT(!(flag & DNODE_MUST_BE_FREE) || (slots > 0)); 1287 IMPLY(flag & DNODE_DRY_RUN, (tag == NULL) && (dnp == NULL)); 1288 1289 /* 1290 * If you are holding the spa config lock as writer, you shouldn't 1291 * be asking the DMU to do *anything* unless it's the root pool 1292 * which may require us to read from the root filesystem while 1293 * holding some (not all) of the locks as writer. 1294 */ 1295 ASSERT(spa_config_held(os->os_spa, SCL_ALL, RW_WRITER) == 0 || 1296 (spa_is_root(os->os_spa) && 1297 spa_config_held(os->os_spa, SCL_STATE, RW_WRITER))); 1298 1299 ASSERT((flag & DNODE_MUST_BE_ALLOCATED) || (flag & DNODE_MUST_BE_FREE)); 1300 1301 if (object == DMU_USERUSED_OBJECT || object == DMU_GROUPUSED_OBJECT || 1302 object == DMU_PROJECTUSED_OBJECT) { 1303 if (object == DMU_USERUSED_OBJECT) 1304 dn = DMU_USERUSED_DNODE(os); 1305 else if (object == DMU_GROUPUSED_OBJECT) 1306 dn = DMU_GROUPUSED_DNODE(os); 1307 else 1308 dn = DMU_PROJECTUSED_DNODE(os); 1309 if (dn == NULL) 1310 return (SET_ERROR(ENOENT)); 1311 type = dn->dn_type; 1312 if ((flag & DNODE_MUST_BE_ALLOCATED) && type == DMU_OT_NONE) 1313 return (SET_ERROR(ENOENT)); 1314 if ((flag & DNODE_MUST_BE_FREE) && type != DMU_OT_NONE) 1315 return (SET_ERROR(EEXIST)); 1316 DNODE_VERIFY(dn); 1317 /* Don't actually hold if dry run, just return 0 */ 1318 if (!(flag & DNODE_DRY_RUN)) { 1319 (void) zfs_refcount_add(&dn->dn_holds, tag); 1320 *dnp = dn; 1321 } 1322 return (0); 1323 } 1324 1325 if (object == 0 || object >= DN_MAX_OBJECT) 1326 return (SET_ERROR(EINVAL)); 1327 1328 mdn = DMU_META_DNODE(os); 1329 ASSERT(mdn->dn_object == DMU_META_DNODE_OBJECT); 1330 1331 DNODE_VERIFY(mdn); 1332 1333 if (!RW_WRITE_HELD(&mdn->dn_struct_rwlock)) { 1334 rw_enter(&mdn->dn_struct_rwlock, RW_READER); 1335 drop_struct_lock = TRUE; 1336 } 1337 1338 blk = dbuf_whichblock(mdn, 0, object * sizeof (dnode_phys_t)); 1339 db = dbuf_hold(mdn, blk, FTAG); 1340 if (drop_struct_lock) 1341 rw_exit(&mdn->dn_struct_rwlock); 1342 if (db == NULL) { 1343 DNODE_STAT_BUMP(dnode_hold_dbuf_hold); 1344 return (SET_ERROR(EIO)); 1345 } 1346 1347 /* 1348 * We do not need to decrypt to read the dnode so it doesn't matter 1349 * if we get the encrypted or decrypted version. 1350 */ 1351 err = dbuf_read(db, NULL, DB_RF_CANFAIL | 1352 DB_RF_NO_DECRYPT | DB_RF_NOPREFETCH); 1353 if (err) { 1354 DNODE_STAT_BUMP(dnode_hold_dbuf_read); 1355 dbuf_rele(db, FTAG); 1356 return (err); 1357 } 1358 1359 ASSERT3U(db->db.db_size, >=, 1<<DNODE_SHIFT); 1360 epb = db->db.db_size >> DNODE_SHIFT; 1361 1362 idx = object & (epb - 1); 1363 dn_block = (dnode_phys_t *)db->db.db_data; 1364 1365 ASSERT(DB_DNODE(db)->dn_type == DMU_OT_DNODE); 1366 dnc = dmu_buf_get_user(&db->db); 1367 dnh = NULL; 1368 if (dnc == NULL) { 1369 dnode_children_t *winner; 1370 int skip = 0; 1371 1372 dnc = kmem_zalloc(sizeof (dnode_children_t) + 1373 epb * sizeof (dnode_handle_t), KM_SLEEP); 1374 dnc->dnc_count = epb; 1375 dnh = &dnc->dnc_children[0]; 1376 1377 /* Initialize dnode slot status from dnode_phys_t */ 1378 for (int i = 0; i < epb; i++) { 1379 zrl_init(&dnh[i].dnh_zrlock); 1380 1381 if (skip) { 1382 skip--; 1383 continue; 1384 } 1385 1386 if (dn_block[i].dn_type != DMU_OT_NONE) { 1387 int interior = dn_block[i].dn_extra_slots; 1388 1389 dnode_set_slots(dnc, i, 1, DN_SLOT_ALLOCATED); 1390 dnode_set_slots(dnc, i + 1, interior, 1391 DN_SLOT_INTERIOR); 1392 skip = interior; 1393 } else { 1394 dnh[i].dnh_dnode = DN_SLOT_FREE; 1395 skip = 0; 1396 } 1397 } 1398 1399 dmu_buf_init_user(&dnc->dnc_dbu, NULL, 1400 dnode_buf_evict_async, NULL); 1401 winner = dmu_buf_set_user(&db->db, &dnc->dnc_dbu); 1402 if (winner != NULL) { 1403 1404 for (int i = 0; i < epb; i++) 1405 zrl_destroy(&dnh[i].dnh_zrlock); 1406 1407 kmem_free(dnc, sizeof (dnode_children_t) + 1408 epb * sizeof (dnode_handle_t)); 1409 dnc = winner; 1410 } 1411 } 1412 1413 ASSERT(dnc->dnc_count == epb); 1414 1415 if (flag & DNODE_MUST_BE_ALLOCATED) { 1416 slots = 1; 1417 1418 dnode_slots_hold(dnc, idx, slots); 1419 dnh = &dnc->dnc_children[idx]; 1420 1421 if (DN_SLOT_IS_PTR(dnh->dnh_dnode)) { 1422 dn = dnh->dnh_dnode; 1423 } else if (dnh->dnh_dnode == DN_SLOT_INTERIOR) { 1424 DNODE_STAT_BUMP(dnode_hold_alloc_interior); 1425 dnode_slots_rele(dnc, idx, slots); 1426 dbuf_rele(db, FTAG); 1427 return (SET_ERROR(EEXIST)); 1428 } else if (dnh->dnh_dnode != DN_SLOT_ALLOCATED) { 1429 DNODE_STAT_BUMP(dnode_hold_alloc_misses); 1430 dnode_slots_rele(dnc, idx, slots); 1431 dbuf_rele(db, FTAG); 1432 return (SET_ERROR(ENOENT)); 1433 } else { 1434 dnode_slots_rele(dnc, idx, slots); 1435 while (!dnode_slots_tryenter(dnc, idx, slots)) { 1436 DNODE_STAT_BUMP(dnode_hold_alloc_lock_retry); 1437 cond_resched(); 1438 } 1439 1440 /* 1441 * Someone else won the race and called dnode_create() 1442 * after we checked DN_SLOT_IS_PTR() above but before 1443 * we acquired the lock. 1444 */ 1445 if (DN_SLOT_IS_PTR(dnh->dnh_dnode)) { 1446 DNODE_STAT_BUMP(dnode_hold_alloc_lock_misses); 1447 dn = dnh->dnh_dnode; 1448 } else { 1449 dn = dnode_create(os, dn_block + idx, db, 1450 object, dnh); 1451 } 1452 } 1453 1454 mutex_enter(&dn->dn_mtx); 1455 if (dn->dn_type == DMU_OT_NONE || dn->dn_free_txg != 0) { 1456 DNODE_STAT_BUMP(dnode_hold_alloc_type_none); 1457 mutex_exit(&dn->dn_mtx); 1458 dnode_slots_rele(dnc, idx, slots); 1459 dbuf_rele(db, FTAG); 1460 return (SET_ERROR(ENOENT)); 1461 } 1462 1463 /* Don't actually hold if dry run, just return 0 */ 1464 if (flag & DNODE_DRY_RUN) { 1465 mutex_exit(&dn->dn_mtx); 1466 dnode_slots_rele(dnc, idx, slots); 1467 dbuf_rele(db, FTAG); 1468 return (0); 1469 } 1470 1471 DNODE_STAT_BUMP(dnode_hold_alloc_hits); 1472 } else if (flag & DNODE_MUST_BE_FREE) { 1473 1474 if (idx + slots - 1 >= DNODES_PER_BLOCK) { 1475 DNODE_STAT_BUMP(dnode_hold_free_overflow); 1476 dbuf_rele(db, FTAG); 1477 return (SET_ERROR(ENOSPC)); 1478 } 1479 1480 dnode_slots_hold(dnc, idx, slots); 1481 1482 if (!dnode_check_slots_free(dnc, idx, slots)) { 1483 DNODE_STAT_BUMP(dnode_hold_free_misses); 1484 dnode_slots_rele(dnc, idx, slots); 1485 dbuf_rele(db, FTAG); 1486 return (SET_ERROR(ENOSPC)); 1487 } 1488 1489 dnode_slots_rele(dnc, idx, slots); 1490 while (!dnode_slots_tryenter(dnc, idx, slots)) { 1491 DNODE_STAT_BUMP(dnode_hold_free_lock_retry); 1492 cond_resched(); 1493 } 1494 1495 if (!dnode_check_slots_free(dnc, idx, slots)) { 1496 DNODE_STAT_BUMP(dnode_hold_free_lock_misses); 1497 dnode_slots_rele(dnc, idx, slots); 1498 dbuf_rele(db, FTAG); 1499 return (SET_ERROR(ENOSPC)); 1500 } 1501 1502 /* 1503 * Allocated but otherwise free dnodes which would 1504 * be in the interior of a multi-slot dnodes need 1505 * to be freed. Single slot dnodes can be safely 1506 * re-purposed as a performance optimization. 1507 */ 1508 if (slots > 1) 1509 dnode_reclaim_slots(dnc, idx + 1, slots - 1); 1510 1511 dnh = &dnc->dnc_children[idx]; 1512 if (DN_SLOT_IS_PTR(dnh->dnh_dnode)) { 1513 dn = dnh->dnh_dnode; 1514 } else { 1515 dn = dnode_create(os, dn_block + idx, db, 1516 object, dnh); 1517 } 1518 1519 mutex_enter(&dn->dn_mtx); 1520 if (!zfs_refcount_is_zero(&dn->dn_holds) || dn->dn_free_txg) { 1521 DNODE_STAT_BUMP(dnode_hold_free_refcount); 1522 mutex_exit(&dn->dn_mtx); 1523 dnode_slots_rele(dnc, idx, slots); 1524 dbuf_rele(db, FTAG); 1525 return (SET_ERROR(EEXIST)); 1526 } 1527 1528 /* Don't actually hold if dry run, just return 0 */ 1529 if (flag & DNODE_DRY_RUN) { 1530 mutex_exit(&dn->dn_mtx); 1531 dnode_slots_rele(dnc, idx, slots); 1532 dbuf_rele(db, FTAG); 1533 return (0); 1534 } 1535 1536 dnode_set_slots(dnc, idx + 1, slots - 1, DN_SLOT_INTERIOR); 1537 DNODE_STAT_BUMP(dnode_hold_free_hits); 1538 } else { 1539 dbuf_rele(db, FTAG); 1540 return (SET_ERROR(EINVAL)); 1541 } 1542 1543 ASSERT0(dn->dn_free_txg); 1544 1545 if (zfs_refcount_add(&dn->dn_holds, tag) == 1) 1546 dbuf_add_ref(db, dnh); 1547 1548 mutex_exit(&dn->dn_mtx); 1549 1550 /* Now we can rely on the hold to prevent the dnode from moving. */ 1551 dnode_slots_rele(dnc, idx, slots); 1552 1553 DNODE_VERIFY(dn); 1554 ASSERT3P(dnp, !=, NULL); 1555 ASSERT3P(dn->dn_dbuf, ==, db); 1556 ASSERT3U(dn->dn_object, ==, object); 1557 dbuf_rele(db, FTAG); 1558 1559 *dnp = dn; 1560 return (0); 1561 } 1562 1563 /* 1564 * Return held dnode if the object is allocated, NULL if not. 1565 */ 1566 int 1567 dnode_hold(objset_t *os, uint64_t object, void *tag, dnode_t **dnp) 1568 { 1569 return (dnode_hold_impl(os, object, DNODE_MUST_BE_ALLOCATED, 0, tag, 1570 dnp)); 1571 } 1572 1573 /* 1574 * Can only add a reference if there is already at least one 1575 * reference on the dnode. Returns FALSE if unable to add a 1576 * new reference. 1577 */ 1578 boolean_t 1579 dnode_add_ref(dnode_t *dn, void *tag) 1580 { 1581 mutex_enter(&dn->dn_mtx); 1582 if (zfs_refcount_is_zero(&dn->dn_holds)) { 1583 mutex_exit(&dn->dn_mtx); 1584 return (FALSE); 1585 } 1586 VERIFY(1 < zfs_refcount_add(&dn->dn_holds, tag)); 1587 mutex_exit(&dn->dn_mtx); 1588 return (TRUE); 1589 } 1590 1591 void 1592 dnode_rele(dnode_t *dn, void *tag) 1593 { 1594 mutex_enter(&dn->dn_mtx); 1595 dnode_rele_and_unlock(dn, tag, B_FALSE); 1596 } 1597 1598 void 1599 dnode_rele_and_unlock(dnode_t *dn, void *tag, boolean_t evicting) 1600 { 1601 uint64_t refs; 1602 /* Get while the hold prevents the dnode from moving. */ 1603 dmu_buf_impl_t *db = dn->dn_dbuf; 1604 dnode_handle_t *dnh = dn->dn_handle; 1605 1606 refs = zfs_refcount_remove(&dn->dn_holds, tag); 1607 if (refs == 0) 1608 cv_broadcast(&dn->dn_nodnholds); 1609 mutex_exit(&dn->dn_mtx); 1610 /* dnode could get destroyed at this point, so don't use it anymore */ 1611 1612 /* 1613 * It's unsafe to release the last hold on a dnode by dnode_rele() or 1614 * indirectly by dbuf_rele() while relying on the dnode handle to 1615 * prevent the dnode from moving, since releasing the last hold could 1616 * result in the dnode's parent dbuf evicting its dnode handles. For 1617 * that reason anyone calling dnode_rele() or dbuf_rele() without some 1618 * other direct or indirect hold on the dnode must first drop the dnode 1619 * handle. 1620 */ 1621 #ifdef ZFS_DEBUG 1622 ASSERT(refs > 0 || dnh->dnh_zrlock.zr_owner != curthread); 1623 #endif 1624 1625 /* NOTE: the DNODE_DNODE does not have a dn_dbuf */ 1626 if (refs == 0 && db != NULL) { 1627 /* 1628 * Another thread could add a hold to the dnode handle in 1629 * dnode_hold_impl() while holding the parent dbuf. Since the 1630 * hold on the parent dbuf prevents the handle from being 1631 * destroyed, the hold on the handle is OK. We can't yet assert 1632 * that the handle has zero references, but that will be 1633 * asserted anyway when the handle gets destroyed. 1634 */ 1635 mutex_enter(&db->db_mtx); 1636 dbuf_rele_and_unlock(db, dnh, evicting); 1637 } 1638 } 1639 1640 /* 1641 * Test whether we can create a dnode at the specified location. 1642 */ 1643 int 1644 dnode_try_claim(objset_t *os, uint64_t object, int slots) 1645 { 1646 return (dnode_hold_impl(os, object, DNODE_MUST_BE_FREE | DNODE_DRY_RUN, 1647 slots, NULL, NULL)); 1648 } 1649 1650 /* 1651 * Checks if the dnode contains any uncommitted dirty records. 1652 */ 1653 boolean_t 1654 dnode_is_dirty(dnode_t *dn) 1655 { 1656 mutex_enter(&dn->dn_mtx); 1657 1658 for (int i = 0; i < TXG_SIZE; i++) { 1659 if (multilist_link_active(&dn->dn_dirty_link[i])) { 1660 mutex_exit(&dn->dn_mtx); 1661 return (B_TRUE); 1662 } 1663 } 1664 1665 mutex_exit(&dn->dn_mtx); 1666 1667 return (B_FALSE); 1668 } 1669 1670 void 1671 dnode_setdirty(dnode_t *dn, dmu_tx_t *tx) 1672 { 1673 objset_t *os = dn->dn_objset; 1674 uint64_t txg = tx->tx_txg; 1675 1676 if (DMU_OBJECT_IS_SPECIAL(dn->dn_object)) { 1677 dsl_dataset_dirty(os->os_dsl_dataset, tx); 1678 return; 1679 } 1680 1681 DNODE_VERIFY(dn); 1682 1683 #ifdef ZFS_DEBUG 1684 mutex_enter(&dn->dn_mtx); 1685 ASSERT(dn->dn_phys->dn_type || dn->dn_allocated_txg); 1686 ASSERT(dn->dn_free_txg == 0 || dn->dn_free_txg >= txg); 1687 mutex_exit(&dn->dn_mtx); 1688 #endif 1689 1690 /* 1691 * Determine old uid/gid when necessary 1692 */ 1693 dmu_objset_userquota_get_ids(dn, B_TRUE, tx); 1694 1695 multilist_t *dirtylist = &os->os_dirty_dnodes[txg & TXG_MASK]; 1696 multilist_sublist_t *mls = multilist_sublist_lock_obj(dirtylist, dn); 1697 1698 /* 1699 * If we are already marked dirty, we're done. 1700 */ 1701 if (multilist_link_active(&dn->dn_dirty_link[txg & TXG_MASK])) { 1702 multilist_sublist_unlock(mls); 1703 return; 1704 } 1705 1706 ASSERT(!zfs_refcount_is_zero(&dn->dn_holds) || 1707 !avl_is_empty(&dn->dn_dbufs)); 1708 ASSERT(dn->dn_datablksz != 0); 1709 ASSERT0(dn->dn_next_bonuslen[txg & TXG_MASK]); 1710 ASSERT0(dn->dn_next_blksz[txg & TXG_MASK]); 1711 ASSERT0(dn->dn_next_bonustype[txg & TXG_MASK]); 1712 1713 dprintf_ds(os->os_dsl_dataset, "obj=%llu txg=%llu\n", 1714 (u_longlong_t)dn->dn_object, (u_longlong_t)txg); 1715 1716 multilist_sublist_insert_head(mls, dn); 1717 1718 multilist_sublist_unlock(mls); 1719 1720 /* 1721 * The dnode maintains a hold on its containing dbuf as 1722 * long as there are holds on it. Each instantiated child 1723 * dbuf maintains a hold on the dnode. When the last child 1724 * drops its hold, the dnode will drop its hold on the 1725 * containing dbuf. We add a "dirty hold" here so that the 1726 * dnode will hang around after we finish processing its 1727 * children. 1728 */ 1729 VERIFY(dnode_add_ref(dn, (void *)(uintptr_t)tx->tx_txg)); 1730 1731 (void) dbuf_dirty(dn->dn_dbuf, tx); 1732 1733 dsl_dataset_dirty(os->os_dsl_dataset, tx); 1734 } 1735 1736 void 1737 dnode_free(dnode_t *dn, dmu_tx_t *tx) 1738 { 1739 mutex_enter(&dn->dn_mtx); 1740 if (dn->dn_type == DMU_OT_NONE || dn->dn_free_txg) { 1741 mutex_exit(&dn->dn_mtx); 1742 return; 1743 } 1744 dn->dn_free_txg = tx->tx_txg; 1745 mutex_exit(&dn->dn_mtx); 1746 1747 dnode_setdirty(dn, tx); 1748 } 1749 1750 /* 1751 * Try to change the block size for the indicated dnode. This can only 1752 * succeed if there are no blocks allocated or dirty beyond first block 1753 */ 1754 int 1755 dnode_set_blksz(dnode_t *dn, uint64_t size, int ibs, dmu_tx_t *tx) 1756 { 1757 dmu_buf_impl_t *db; 1758 int err; 1759 1760 ASSERT3U(size, <=, spa_maxblocksize(dmu_objset_spa(dn->dn_objset))); 1761 if (size == 0) 1762 size = SPA_MINBLOCKSIZE; 1763 else 1764 size = P2ROUNDUP(size, SPA_MINBLOCKSIZE); 1765 1766 if (ibs == dn->dn_indblkshift) 1767 ibs = 0; 1768 1769 if (size >> SPA_MINBLOCKSHIFT == dn->dn_datablkszsec && ibs == 0) 1770 return (0); 1771 1772 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 1773 1774 /* Check for any allocated blocks beyond the first */ 1775 if (dn->dn_maxblkid != 0) 1776 goto fail; 1777 1778 mutex_enter(&dn->dn_dbufs_mtx); 1779 for (db = avl_first(&dn->dn_dbufs); db != NULL; 1780 db = AVL_NEXT(&dn->dn_dbufs, db)) { 1781 if (db->db_blkid != 0 && db->db_blkid != DMU_BONUS_BLKID && 1782 db->db_blkid != DMU_SPILL_BLKID) { 1783 mutex_exit(&dn->dn_dbufs_mtx); 1784 goto fail; 1785 } 1786 } 1787 mutex_exit(&dn->dn_dbufs_mtx); 1788 1789 if (ibs && dn->dn_nlevels != 1) 1790 goto fail; 1791 1792 /* resize the old block */ 1793 err = dbuf_hold_impl(dn, 0, 0, TRUE, FALSE, FTAG, &db); 1794 if (err == 0) { 1795 dbuf_new_size(db, size, tx); 1796 } else if (err != ENOENT) { 1797 goto fail; 1798 } 1799 1800 dnode_setdblksz(dn, size); 1801 dnode_setdirty(dn, tx); 1802 dn->dn_next_blksz[tx->tx_txg&TXG_MASK] = size; 1803 if (ibs) { 1804 dn->dn_indblkshift = ibs; 1805 dn->dn_next_indblkshift[tx->tx_txg&TXG_MASK] = ibs; 1806 } 1807 /* release after we have fixed the blocksize in the dnode */ 1808 if (db) 1809 dbuf_rele(db, FTAG); 1810 1811 rw_exit(&dn->dn_struct_rwlock); 1812 return (0); 1813 1814 fail: 1815 rw_exit(&dn->dn_struct_rwlock); 1816 return (SET_ERROR(ENOTSUP)); 1817 } 1818 1819 static void 1820 dnode_set_nlevels_impl(dnode_t *dn, int new_nlevels, dmu_tx_t *tx) 1821 { 1822 uint64_t txgoff = tx->tx_txg & TXG_MASK; 1823 int old_nlevels = dn->dn_nlevels; 1824 dmu_buf_impl_t *db; 1825 list_t *list; 1826 dbuf_dirty_record_t *new, *dr, *dr_next; 1827 1828 ASSERT(RW_WRITE_HELD(&dn->dn_struct_rwlock)); 1829 1830 ASSERT3U(new_nlevels, >, dn->dn_nlevels); 1831 dn->dn_nlevels = new_nlevels; 1832 1833 ASSERT3U(new_nlevels, >, dn->dn_next_nlevels[txgoff]); 1834 dn->dn_next_nlevels[txgoff] = new_nlevels; 1835 1836 /* dirty the left indirects */ 1837 db = dbuf_hold_level(dn, old_nlevels, 0, FTAG); 1838 ASSERT(db != NULL); 1839 new = dbuf_dirty(db, tx); 1840 dbuf_rele(db, FTAG); 1841 1842 /* transfer the dirty records to the new indirect */ 1843 mutex_enter(&dn->dn_mtx); 1844 mutex_enter(&new->dt.di.dr_mtx); 1845 list = &dn->dn_dirty_records[txgoff]; 1846 for (dr = list_head(list); dr; dr = dr_next) { 1847 dr_next = list_next(&dn->dn_dirty_records[txgoff], dr); 1848 1849 IMPLY(dr->dr_dbuf == NULL, old_nlevels == 1); 1850 if (dr->dr_dbuf == NULL || 1851 (dr->dr_dbuf->db_level == old_nlevels - 1 && 1852 dr->dr_dbuf->db_blkid != DMU_BONUS_BLKID && 1853 dr->dr_dbuf->db_blkid != DMU_SPILL_BLKID)) { 1854 list_remove(&dn->dn_dirty_records[txgoff], dr); 1855 list_insert_tail(&new->dt.di.dr_children, dr); 1856 dr->dr_parent = new; 1857 } 1858 } 1859 mutex_exit(&new->dt.di.dr_mtx); 1860 mutex_exit(&dn->dn_mtx); 1861 } 1862 1863 int 1864 dnode_set_nlevels(dnode_t *dn, int nlevels, dmu_tx_t *tx) 1865 { 1866 int ret = 0; 1867 1868 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 1869 1870 if (dn->dn_nlevels == nlevels) { 1871 ret = 0; 1872 goto out; 1873 } else if (nlevels < dn->dn_nlevels) { 1874 ret = SET_ERROR(EINVAL); 1875 goto out; 1876 } 1877 1878 dnode_set_nlevels_impl(dn, nlevels, tx); 1879 1880 out: 1881 rw_exit(&dn->dn_struct_rwlock); 1882 return (ret); 1883 } 1884 1885 /* read-holding callers must not rely on the lock being continuously held */ 1886 void 1887 dnode_new_blkid(dnode_t *dn, uint64_t blkid, dmu_tx_t *tx, boolean_t have_read, 1888 boolean_t force) 1889 { 1890 int epbs, new_nlevels; 1891 uint64_t sz; 1892 1893 ASSERT(blkid != DMU_BONUS_BLKID); 1894 1895 ASSERT(have_read ? 1896 RW_READ_HELD(&dn->dn_struct_rwlock) : 1897 RW_WRITE_HELD(&dn->dn_struct_rwlock)); 1898 1899 /* 1900 * if we have a read-lock, check to see if we need to do any work 1901 * before upgrading to a write-lock. 1902 */ 1903 if (have_read) { 1904 if (blkid <= dn->dn_maxblkid) 1905 return; 1906 1907 if (!rw_tryupgrade(&dn->dn_struct_rwlock)) { 1908 rw_exit(&dn->dn_struct_rwlock); 1909 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 1910 } 1911 } 1912 1913 /* 1914 * Raw sends (indicated by the force flag) require that we take the 1915 * given blkid even if the value is lower than the current value. 1916 */ 1917 if (!force && blkid <= dn->dn_maxblkid) 1918 goto out; 1919 1920 /* 1921 * We use the (otherwise unused) top bit of dn_next_maxblkid[txgoff] 1922 * to indicate that this field is set. This allows us to set the 1923 * maxblkid to 0 on an existing object in dnode_sync(). 1924 */ 1925 dn->dn_maxblkid = blkid; 1926 dn->dn_next_maxblkid[tx->tx_txg & TXG_MASK] = 1927 blkid | DMU_NEXT_MAXBLKID_SET; 1928 1929 /* 1930 * Compute the number of levels necessary to support the new maxblkid. 1931 * Raw sends will ensure nlevels is set correctly for us. 1932 */ 1933 new_nlevels = 1; 1934 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT; 1935 for (sz = dn->dn_nblkptr; 1936 sz <= blkid && sz >= dn->dn_nblkptr; sz <<= epbs) 1937 new_nlevels++; 1938 1939 ASSERT3U(new_nlevels, <=, DN_MAX_LEVELS); 1940 1941 if (!force) { 1942 if (new_nlevels > dn->dn_nlevels) 1943 dnode_set_nlevels_impl(dn, new_nlevels, tx); 1944 } else { 1945 ASSERT3U(dn->dn_nlevels, >=, new_nlevels); 1946 } 1947 1948 out: 1949 if (have_read) 1950 rw_downgrade(&dn->dn_struct_rwlock); 1951 } 1952 1953 static void 1954 dnode_dirty_l1(dnode_t *dn, uint64_t l1blkid, dmu_tx_t *tx) 1955 { 1956 dmu_buf_impl_t *db = dbuf_hold_level(dn, 1, l1blkid, FTAG); 1957 if (db != NULL) { 1958 dmu_buf_will_dirty(&db->db, tx); 1959 dbuf_rele(db, FTAG); 1960 } 1961 } 1962 1963 /* 1964 * Dirty all the in-core level-1 dbufs in the range specified by start_blkid 1965 * and end_blkid. 1966 */ 1967 static void 1968 dnode_dirty_l1range(dnode_t *dn, uint64_t start_blkid, uint64_t end_blkid, 1969 dmu_tx_t *tx) 1970 { 1971 dmu_buf_impl_t *db_search; 1972 dmu_buf_impl_t *db; 1973 avl_index_t where; 1974 1975 db_search = kmem_zalloc(sizeof (dmu_buf_impl_t), KM_SLEEP); 1976 1977 mutex_enter(&dn->dn_dbufs_mtx); 1978 1979 db_search->db_level = 1; 1980 db_search->db_blkid = start_blkid + 1; 1981 db_search->db_state = DB_SEARCH; 1982 for (;;) { 1983 1984 db = avl_find(&dn->dn_dbufs, db_search, &where); 1985 if (db == NULL) 1986 db = avl_nearest(&dn->dn_dbufs, where, AVL_AFTER); 1987 1988 if (db == NULL || db->db_level != 1 || 1989 db->db_blkid >= end_blkid) { 1990 break; 1991 } 1992 1993 /* 1994 * Setup the next blkid we want to search for. 1995 */ 1996 db_search->db_blkid = db->db_blkid + 1; 1997 ASSERT3U(db->db_blkid, >=, start_blkid); 1998 1999 /* 2000 * If the dbuf transitions to DB_EVICTING while we're trying 2001 * to dirty it, then we will be unable to discover it in 2002 * the dbuf hash table. This will result in a call to 2003 * dbuf_create() which needs to acquire the dn_dbufs_mtx 2004 * lock. To avoid a deadlock, we drop the lock before 2005 * dirtying the level-1 dbuf. 2006 */ 2007 mutex_exit(&dn->dn_dbufs_mtx); 2008 dnode_dirty_l1(dn, db->db_blkid, tx); 2009 mutex_enter(&dn->dn_dbufs_mtx); 2010 } 2011 2012 #ifdef ZFS_DEBUG 2013 /* 2014 * Walk all the in-core level-1 dbufs and verify they have been dirtied. 2015 */ 2016 db_search->db_level = 1; 2017 db_search->db_blkid = start_blkid + 1; 2018 db_search->db_state = DB_SEARCH; 2019 db = avl_find(&dn->dn_dbufs, db_search, &where); 2020 if (db == NULL) 2021 db = avl_nearest(&dn->dn_dbufs, where, AVL_AFTER); 2022 for (; db != NULL; db = AVL_NEXT(&dn->dn_dbufs, db)) { 2023 if (db->db_level != 1 || db->db_blkid >= end_blkid) 2024 break; 2025 if (db->db_state != DB_EVICTING) 2026 ASSERT(db->db_dirtycnt > 0); 2027 } 2028 #endif 2029 kmem_free(db_search, sizeof (dmu_buf_impl_t)); 2030 mutex_exit(&dn->dn_dbufs_mtx); 2031 } 2032 2033 void 2034 dnode_set_dirtyctx(dnode_t *dn, dmu_tx_t *tx, void *tag) 2035 { 2036 /* 2037 * Don't set dirtyctx to SYNC if we're just modifying this as we 2038 * initialize the objset. 2039 */ 2040 if (dn->dn_dirtyctx == DN_UNDIRTIED) { 2041 dsl_dataset_t *ds = dn->dn_objset->os_dsl_dataset; 2042 2043 if (ds != NULL) { 2044 rrw_enter(&ds->ds_bp_rwlock, RW_READER, tag); 2045 } 2046 if (!BP_IS_HOLE(dn->dn_objset->os_rootbp)) { 2047 if (dmu_tx_is_syncing(tx)) 2048 dn->dn_dirtyctx = DN_DIRTY_SYNC; 2049 else 2050 dn->dn_dirtyctx = DN_DIRTY_OPEN; 2051 dn->dn_dirtyctx_firstset = tag; 2052 } 2053 if (ds != NULL) { 2054 rrw_exit(&ds->ds_bp_rwlock, tag); 2055 } 2056 } 2057 } 2058 2059 static void 2060 dnode_partial_zero(dnode_t *dn, uint64_t off, uint64_t blkoff, uint64_t len, 2061 dmu_tx_t *tx) 2062 { 2063 dmu_buf_impl_t *db; 2064 int res; 2065 2066 rw_enter(&dn->dn_struct_rwlock, RW_READER); 2067 res = dbuf_hold_impl(dn, 0, dbuf_whichblock(dn, 0, off), TRUE, FALSE, 2068 FTAG, &db); 2069 rw_exit(&dn->dn_struct_rwlock); 2070 if (res == 0) { 2071 db_lock_type_t dblt; 2072 boolean_t dirty; 2073 2074 dblt = dmu_buf_lock_parent(db, RW_READER, FTAG); 2075 /* don't dirty if not on disk and not dirty */ 2076 dirty = !list_is_empty(&db->db_dirty_records) || 2077 (db->db_blkptr && !BP_IS_HOLE(db->db_blkptr)); 2078 dmu_buf_unlock_parent(db, dblt, FTAG); 2079 if (dirty) { 2080 caddr_t data; 2081 2082 dmu_buf_will_dirty(&db->db, tx); 2083 data = db->db.db_data; 2084 bzero(data + blkoff, len); 2085 } 2086 dbuf_rele(db, FTAG); 2087 } 2088 } 2089 2090 void 2091 dnode_free_range(dnode_t *dn, uint64_t off, uint64_t len, dmu_tx_t *tx) 2092 { 2093 uint64_t blkoff, blkid, nblks; 2094 int blksz, blkshift, head, tail; 2095 int trunc = FALSE; 2096 int epbs; 2097 2098 blksz = dn->dn_datablksz; 2099 blkshift = dn->dn_datablkshift; 2100 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT; 2101 2102 if (len == DMU_OBJECT_END) { 2103 len = UINT64_MAX - off; 2104 trunc = TRUE; 2105 } 2106 2107 /* 2108 * First, block align the region to free: 2109 */ 2110 if (ISP2(blksz)) { 2111 head = P2NPHASE(off, blksz); 2112 blkoff = P2PHASE(off, blksz); 2113 if ((off >> blkshift) > dn->dn_maxblkid) 2114 return; 2115 } else { 2116 ASSERT(dn->dn_maxblkid == 0); 2117 if (off == 0 && len >= blksz) { 2118 /* 2119 * Freeing the whole block; fast-track this request. 2120 */ 2121 blkid = 0; 2122 nblks = 1; 2123 if (dn->dn_nlevels > 1) { 2124 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 2125 dnode_dirty_l1(dn, 0, tx); 2126 rw_exit(&dn->dn_struct_rwlock); 2127 } 2128 goto done; 2129 } else if (off >= blksz) { 2130 /* Freeing past end-of-data */ 2131 return; 2132 } else { 2133 /* Freeing part of the block. */ 2134 head = blksz - off; 2135 ASSERT3U(head, >, 0); 2136 } 2137 blkoff = off; 2138 } 2139 /* zero out any partial block data at the start of the range */ 2140 if (head) { 2141 ASSERT3U(blkoff + head, ==, blksz); 2142 if (len < head) 2143 head = len; 2144 dnode_partial_zero(dn, off, blkoff, head, tx); 2145 off += head; 2146 len -= head; 2147 } 2148 2149 /* If the range was less than one block, we're done */ 2150 if (len == 0) 2151 return; 2152 2153 /* If the remaining range is past end of file, we're done */ 2154 if ((off >> blkshift) > dn->dn_maxblkid) 2155 return; 2156 2157 ASSERT(ISP2(blksz)); 2158 if (trunc) 2159 tail = 0; 2160 else 2161 tail = P2PHASE(len, blksz); 2162 2163 ASSERT0(P2PHASE(off, blksz)); 2164 /* zero out any partial block data at the end of the range */ 2165 if (tail) { 2166 if (len < tail) 2167 tail = len; 2168 dnode_partial_zero(dn, off + len, 0, tail, tx); 2169 len -= tail; 2170 } 2171 2172 /* If the range did not include a full block, we are done */ 2173 if (len == 0) 2174 return; 2175 2176 ASSERT(IS_P2ALIGNED(off, blksz)); 2177 ASSERT(trunc || IS_P2ALIGNED(len, blksz)); 2178 blkid = off >> blkshift; 2179 nblks = len >> blkshift; 2180 if (trunc) 2181 nblks += 1; 2182 2183 /* 2184 * Dirty all the indirect blocks in this range. Note that only 2185 * the first and last indirect blocks can actually be written 2186 * (if they were partially freed) -- they must be dirtied, even if 2187 * they do not exist on disk yet. The interior blocks will 2188 * be freed by free_children(), so they will not actually be written. 2189 * Even though these interior blocks will not be written, we 2190 * dirty them for two reasons: 2191 * 2192 * - It ensures that the indirect blocks remain in memory until 2193 * syncing context. (They have already been prefetched by 2194 * dmu_tx_hold_free(), so we don't have to worry about reading 2195 * them serially here.) 2196 * 2197 * - The dirty space accounting will put pressure on the txg sync 2198 * mechanism to begin syncing, and to delay transactions if there 2199 * is a large amount of freeing. Even though these indirect 2200 * blocks will not be written, we could need to write the same 2201 * amount of space if we copy the freed BPs into deadlists. 2202 */ 2203 if (dn->dn_nlevels > 1) { 2204 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 2205 uint64_t first, last; 2206 2207 first = blkid >> epbs; 2208 dnode_dirty_l1(dn, first, tx); 2209 if (trunc) 2210 last = dn->dn_maxblkid >> epbs; 2211 else 2212 last = (blkid + nblks - 1) >> epbs; 2213 if (last != first) 2214 dnode_dirty_l1(dn, last, tx); 2215 2216 dnode_dirty_l1range(dn, first, last, tx); 2217 2218 int shift = dn->dn_datablkshift + dn->dn_indblkshift - 2219 SPA_BLKPTRSHIFT; 2220 for (uint64_t i = first + 1; i < last; i++) { 2221 /* 2222 * Set i to the blockid of the next non-hole 2223 * level-1 indirect block at or after i. Note 2224 * that dnode_next_offset() operates in terms of 2225 * level-0-equivalent bytes. 2226 */ 2227 uint64_t ibyte = i << shift; 2228 int err = dnode_next_offset(dn, DNODE_FIND_HAVELOCK, 2229 &ibyte, 2, 1, 0); 2230 i = ibyte >> shift; 2231 if (i >= last) 2232 break; 2233 2234 /* 2235 * Normally we should not see an error, either 2236 * from dnode_next_offset() or dbuf_hold_level() 2237 * (except for ESRCH from dnode_next_offset). 2238 * If there is an i/o error, then when we read 2239 * this block in syncing context, it will use 2240 * ZIO_FLAG_MUSTSUCCEED, and thus hang/panic according 2241 * to the "failmode" property. dnode_next_offset() 2242 * doesn't have a flag to indicate MUSTSUCCEED. 2243 */ 2244 if (err != 0) 2245 break; 2246 2247 dnode_dirty_l1(dn, i, tx); 2248 } 2249 rw_exit(&dn->dn_struct_rwlock); 2250 } 2251 2252 done: 2253 /* 2254 * Add this range to the dnode range list. 2255 * We will finish up this free operation in the syncing phase. 2256 */ 2257 mutex_enter(&dn->dn_mtx); 2258 { 2259 int txgoff = tx->tx_txg & TXG_MASK; 2260 if (dn->dn_free_ranges[txgoff] == NULL) { 2261 dn->dn_free_ranges[txgoff] = range_tree_create(NULL, 2262 RANGE_SEG64, NULL, 0, 0); 2263 } 2264 range_tree_clear(dn->dn_free_ranges[txgoff], blkid, nblks); 2265 range_tree_add(dn->dn_free_ranges[txgoff], blkid, nblks); 2266 } 2267 dprintf_dnode(dn, "blkid=%llu nblks=%llu txg=%llu\n", 2268 (u_longlong_t)blkid, (u_longlong_t)nblks, 2269 (u_longlong_t)tx->tx_txg); 2270 mutex_exit(&dn->dn_mtx); 2271 2272 dbuf_free_range(dn, blkid, blkid + nblks - 1, tx); 2273 dnode_setdirty(dn, tx); 2274 } 2275 2276 static boolean_t 2277 dnode_spill_freed(dnode_t *dn) 2278 { 2279 int i; 2280 2281 mutex_enter(&dn->dn_mtx); 2282 for (i = 0; i < TXG_SIZE; i++) { 2283 if (dn->dn_rm_spillblk[i] == DN_KILL_SPILLBLK) 2284 break; 2285 } 2286 mutex_exit(&dn->dn_mtx); 2287 return (i < TXG_SIZE); 2288 } 2289 2290 /* return TRUE if this blkid was freed in a recent txg, or FALSE if it wasn't */ 2291 uint64_t 2292 dnode_block_freed(dnode_t *dn, uint64_t blkid) 2293 { 2294 void *dp = spa_get_dsl(dn->dn_objset->os_spa); 2295 int i; 2296 2297 if (blkid == DMU_BONUS_BLKID) 2298 return (FALSE); 2299 2300 /* 2301 * If we're in the process of opening the pool, dp will not be 2302 * set yet, but there shouldn't be anything dirty. 2303 */ 2304 if (dp == NULL) 2305 return (FALSE); 2306 2307 if (dn->dn_free_txg) 2308 return (TRUE); 2309 2310 if (blkid == DMU_SPILL_BLKID) 2311 return (dnode_spill_freed(dn)); 2312 2313 mutex_enter(&dn->dn_mtx); 2314 for (i = 0; i < TXG_SIZE; i++) { 2315 if (dn->dn_free_ranges[i] != NULL && 2316 range_tree_contains(dn->dn_free_ranges[i], blkid, 1)) 2317 break; 2318 } 2319 mutex_exit(&dn->dn_mtx); 2320 return (i < TXG_SIZE); 2321 } 2322 2323 /* call from syncing context when we actually write/free space for this dnode */ 2324 void 2325 dnode_diduse_space(dnode_t *dn, int64_t delta) 2326 { 2327 uint64_t space; 2328 dprintf_dnode(dn, "dn=%p dnp=%p used=%llu delta=%lld\n", 2329 dn, dn->dn_phys, 2330 (u_longlong_t)dn->dn_phys->dn_used, 2331 (longlong_t)delta); 2332 2333 mutex_enter(&dn->dn_mtx); 2334 space = DN_USED_BYTES(dn->dn_phys); 2335 if (delta > 0) { 2336 ASSERT3U(space + delta, >=, space); /* no overflow */ 2337 } else { 2338 ASSERT3U(space, >=, -delta); /* no underflow */ 2339 } 2340 space += delta; 2341 if (spa_version(dn->dn_objset->os_spa) < SPA_VERSION_DNODE_BYTES) { 2342 ASSERT((dn->dn_phys->dn_flags & DNODE_FLAG_USED_BYTES) == 0); 2343 ASSERT0(P2PHASE(space, 1<<DEV_BSHIFT)); 2344 dn->dn_phys->dn_used = space >> DEV_BSHIFT; 2345 } else { 2346 dn->dn_phys->dn_used = space; 2347 dn->dn_phys->dn_flags |= DNODE_FLAG_USED_BYTES; 2348 } 2349 mutex_exit(&dn->dn_mtx); 2350 } 2351 2352 /* 2353 * Scans a block at the indicated "level" looking for a hole or data, 2354 * depending on 'flags'. 2355 * 2356 * If level > 0, then we are scanning an indirect block looking at its 2357 * pointers. If level == 0, then we are looking at a block of dnodes. 2358 * 2359 * If we don't find what we are looking for in the block, we return ESRCH. 2360 * Otherwise, return with *offset pointing to the beginning (if searching 2361 * forwards) or end (if searching backwards) of the range covered by the 2362 * block pointer we matched on (or dnode). 2363 * 2364 * The basic search algorithm used below by dnode_next_offset() is to 2365 * use this function to search up the block tree (widen the search) until 2366 * we find something (i.e., we don't return ESRCH) and then search back 2367 * down the tree (narrow the search) until we reach our original search 2368 * level. 2369 */ 2370 static int 2371 dnode_next_offset_level(dnode_t *dn, int flags, uint64_t *offset, 2372 int lvl, uint64_t blkfill, uint64_t txg) 2373 { 2374 dmu_buf_impl_t *db = NULL; 2375 void *data = NULL; 2376 uint64_t epbs = dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT; 2377 uint64_t epb = 1ULL << epbs; 2378 uint64_t minfill, maxfill; 2379 boolean_t hole; 2380 int i, inc, error, span; 2381 2382 ASSERT(RW_LOCK_HELD(&dn->dn_struct_rwlock)); 2383 2384 hole = ((flags & DNODE_FIND_HOLE) != 0); 2385 inc = (flags & DNODE_FIND_BACKWARDS) ? -1 : 1; 2386 ASSERT(txg == 0 || !hole); 2387 2388 if (lvl == dn->dn_phys->dn_nlevels) { 2389 error = 0; 2390 epb = dn->dn_phys->dn_nblkptr; 2391 data = dn->dn_phys->dn_blkptr; 2392 } else { 2393 uint64_t blkid = dbuf_whichblock(dn, lvl, *offset); 2394 error = dbuf_hold_impl(dn, lvl, blkid, TRUE, FALSE, FTAG, &db); 2395 if (error) { 2396 if (error != ENOENT) 2397 return (error); 2398 if (hole) 2399 return (0); 2400 /* 2401 * This can only happen when we are searching up 2402 * the block tree for data. We don't really need to 2403 * adjust the offset, as we will just end up looking 2404 * at the pointer to this block in its parent, and its 2405 * going to be unallocated, so we will skip over it. 2406 */ 2407 return (SET_ERROR(ESRCH)); 2408 } 2409 error = dbuf_read(db, NULL, 2410 DB_RF_CANFAIL | DB_RF_HAVESTRUCT | 2411 DB_RF_NO_DECRYPT | DB_RF_NOPREFETCH); 2412 if (error) { 2413 dbuf_rele(db, FTAG); 2414 return (error); 2415 } 2416 data = db->db.db_data; 2417 rw_enter(&db->db_rwlock, RW_READER); 2418 } 2419 2420 if (db != NULL && txg != 0 && (db->db_blkptr == NULL || 2421 db->db_blkptr->blk_birth <= txg || 2422 BP_IS_HOLE(db->db_blkptr))) { 2423 /* 2424 * This can only happen when we are searching up the tree 2425 * and these conditions mean that we need to keep climbing. 2426 */ 2427 error = SET_ERROR(ESRCH); 2428 } else if (lvl == 0) { 2429 dnode_phys_t *dnp = data; 2430 2431 ASSERT(dn->dn_type == DMU_OT_DNODE); 2432 ASSERT(!(flags & DNODE_FIND_BACKWARDS)); 2433 2434 for (i = (*offset >> DNODE_SHIFT) & (blkfill - 1); 2435 i < blkfill; i += dnp[i].dn_extra_slots + 1) { 2436 if ((dnp[i].dn_type == DMU_OT_NONE) == hole) 2437 break; 2438 } 2439 2440 if (i == blkfill) 2441 error = SET_ERROR(ESRCH); 2442 2443 *offset = (*offset & ~(DNODE_BLOCK_SIZE - 1)) + 2444 (i << DNODE_SHIFT); 2445 } else { 2446 blkptr_t *bp = data; 2447 uint64_t start = *offset; 2448 span = (lvl - 1) * epbs + dn->dn_datablkshift; 2449 minfill = 0; 2450 maxfill = blkfill << ((lvl - 1) * epbs); 2451 2452 if (hole) 2453 maxfill--; 2454 else 2455 minfill++; 2456 2457 if (span >= 8 * sizeof (*offset)) { 2458 /* This only happens on the highest indirection level */ 2459 ASSERT3U((lvl - 1), ==, dn->dn_phys->dn_nlevels - 1); 2460 *offset = 0; 2461 } else { 2462 *offset = *offset >> span; 2463 } 2464 2465 for (i = BF64_GET(*offset, 0, epbs); 2466 i >= 0 && i < epb; i += inc) { 2467 if (BP_GET_FILL(&bp[i]) >= minfill && 2468 BP_GET_FILL(&bp[i]) <= maxfill && 2469 (hole || bp[i].blk_birth > txg)) 2470 break; 2471 if (inc > 0 || *offset > 0) 2472 *offset += inc; 2473 } 2474 2475 if (span >= 8 * sizeof (*offset)) { 2476 *offset = start; 2477 } else { 2478 *offset = *offset << span; 2479 } 2480 2481 if (inc < 0) { 2482 /* traversing backwards; position offset at the end */ 2483 ASSERT3U(*offset, <=, start); 2484 *offset = MIN(*offset + (1ULL << span) - 1, start); 2485 } else if (*offset < start) { 2486 *offset = start; 2487 } 2488 if (i < 0 || i >= epb) 2489 error = SET_ERROR(ESRCH); 2490 } 2491 2492 if (db != NULL) { 2493 rw_exit(&db->db_rwlock); 2494 dbuf_rele(db, FTAG); 2495 } 2496 2497 return (error); 2498 } 2499 2500 /* 2501 * Find the next hole, data, or sparse region at or after *offset. 2502 * The value 'blkfill' tells us how many items we expect to find 2503 * in an L0 data block; this value is 1 for normal objects, 2504 * DNODES_PER_BLOCK for the meta dnode, and some fraction of 2505 * DNODES_PER_BLOCK when searching for sparse regions thereof. 2506 * 2507 * Examples: 2508 * 2509 * dnode_next_offset(dn, flags, offset, 1, 1, 0); 2510 * Finds the next/previous hole/data in a file. 2511 * Used in dmu_offset_next(). 2512 * 2513 * dnode_next_offset(mdn, flags, offset, 0, DNODES_PER_BLOCK, txg); 2514 * Finds the next free/allocated dnode an objset's meta-dnode. 2515 * Only finds objects that have new contents since txg (ie. 2516 * bonus buffer changes and content removal are ignored). 2517 * Used in dmu_object_next(). 2518 * 2519 * dnode_next_offset(mdn, DNODE_FIND_HOLE, offset, 2, DNODES_PER_BLOCK >> 2, 0); 2520 * Finds the next L2 meta-dnode bp that's at most 1/4 full. 2521 * Used in dmu_object_alloc(). 2522 */ 2523 int 2524 dnode_next_offset(dnode_t *dn, int flags, uint64_t *offset, 2525 int minlvl, uint64_t blkfill, uint64_t txg) 2526 { 2527 uint64_t initial_offset = *offset; 2528 int lvl, maxlvl; 2529 int error = 0; 2530 2531 if (!(flags & DNODE_FIND_HAVELOCK)) 2532 rw_enter(&dn->dn_struct_rwlock, RW_READER); 2533 2534 if (dn->dn_phys->dn_nlevels == 0) { 2535 error = SET_ERROR(ESRCH); 2536 goto out; 2537 } 2538 2539 if (dn->dn_datablkshift == 0) { 2540 if (*offset < dn->dn_datablksz) { 2541 if (flags & DNODE_FIND_HOLE) 2542 *offset = dn->dn_datablksz; 2543 } else { 2544 error = SET_ERROR(ESRCH); 2545 } 2546 goto out; 2547 } 2548 2549 maxlvl = dn->dn_phys->dn_nlevels; 2550 2551 for (lvl = minlvl; lvl <= maxlvl; lvl++) { 2552 error = dnode_next_offset_level(dn, 2553 flags, offset, lvl, blkfill, txg); 2554 if (error != ESRCH) 2555 break; 2556 } 2557 2558 while (error == 0 && --lvl >= minlvl) { 2559 error = dnode_next_offset_level(dn, 2560 flags, offset, lvl, blkfill, txg); 2561 } 2562 2563 /* 2564 * There's always a "virtual hole" at the end of the object, even 2565 * if all BP's which physically exist are non-holes. 2566 */ 2567 if ((flags & DNODE_FIND_HOLE) && error == ESRCH && txg == 0 && 2568 minlvl == 1 && blkfill == 1 && !(flags & DNODE_FIND_BACKWARDS)) { 2569 error = 0; 2570 } 2571 2572 if (error == 0 && (flags & DNODE_FIND_BACKWARDS ? 2573 initial_offset < *offset : initial_offset > *offset)) 2574 error = SET_ERROR(ESRCH); 2575 out: 2576 if (!(flags & DNODE_FIND_HAVELOCK)) 2577 rw_exit(&dn->dn_struct_rwlock); 2578 2579 return (error); 2580 } 2581 2582 #if defined(_KERNEL) 2583 EXPORT_SYMBOL(dnode_hold); 2584 EXPORT_SYMBOL(dnode_rele); 2585 EXPORT_SYMBOL(dnode_set_nlevels); 2586 EXPORT_SYMBOL(dnode_set_blksz); 2587 EXPORT_SYMBOL(dnode_free_range); 2588 EXPORT_SYMBOL(dnode_evict_dbufs); 2589 EXPORT_SYMBOL(dnode_evict_bonus); 2590 #endif 2591