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 memset(dn->dn_next_type, 0, sizeof (dn->dn_next_type)); 132 memset(dn->dn_next_nblkptr, 0, sizeof (dn->dn_next_nblkptr)); 133 memset(dn->dn_next_nlevels, 0, sizeof (dn->dn_next_nlevels)); 134 memset(dn->dn_next_indblkshift, 0, sizeof (dn->dn_next_indblkshift)); 135 memset(dn->dn_next_bonustype, 0, sizeof (dn->dn_next_bonustype)); 136 memset(dn->dn_rm_spillblk, 0, sizeof (dn->dn_rm_spillblk)); 137 memset(dn->dn_next_bonuslen, 0, sizeof (dn->dn_next_bonuslen)); 138 memset(dn->dn_next_blksz, 0, sizeof (dn->dn_next_blksz)); 139 memset(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 memset(dnp, 0, 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 memset(data_end, 0, 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 ASSERT0(memcmp(dn->dn_phys, &dnode_phys_zero, sizeof (dnode_phys_t))); 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 ASSERT(!RW_LOCK_HELD(&odn->dn_struct_rwlock)); 753 ASSERT(MUTEX_NOT_HELD(&odn->dn_mtx)); 754 ASSERT(MUTEX_NOT_HELD(&odn->dn_dbufs_mtx)); 755 756 /* Copy fields. */ 757 ndn->dn_objset = odn->dn_objset; 758 ndn->dn_object = odn->dn_object; 759 ndn->dn_dbuf = odn->dn_dbuf; 760 ndn->dn_handle = odn->dn_handle; 761 ndn->dn_phys = odn->dn_phys; 762 ndn->dn_type = odn->dn_type; 763 ndn->dn_bonuslen = odn->dn_bonuslen; 764 ndn->dn_bonustype = odn->dn_bonustype; 765 ndn->dn_nblkptr = odn->dn_nblkptr; 766 ndn->dn_checksum = odn->dn_checksum; 767 ndn->dn_compress = odn->dn_compress; 768 ndn->dn_nlevels = odn->dn_nlevels; 769 ndn->dn_indblkshift = odn->dn_indblkshift; 770 ndn->dn_datablkshift = odn->dn_datablkshift; 771 ndn->dn_datablkszsec = odn->dn_datablkszsec; 772 ndn->dn_datablksz = odn->dn_datablksz; 773 ndn->dn_maxblkid = odn->dn_maxblkid; 774 ndn->dn_num_slots = odn->dn_num_slots; 775 memcpy(ndn->dn_next_type, odn->dn_next_type, 776 sizeof (odn->dn_next_type)); 777 memcpy(ndn->dn_next_nblkptr, odn->dn_next_nblkptr, 778 sizeof (odn->dn_next_nblkptr)); 779 memcpy(ndn->dn_next_nlevels, odn->dn_next_nlevels, 780 sizeof (odn->dn_next_nlevels)); 781 memcpy(ndn->dn_next_indblkshift, odn->dn_next_indblkshift, 782 sizeof (odn->dn_next_indblkshift)); 783 memcpy(ndn->dn_next_bonustype, odn->dn_next_bonustype, 784 sizeof (odn->dn_next_bonustype)); 785 memcpy(ndn->dn_rm_spillblk, odn->dn_rm_spillblk, 786 sizeof (odn->dn_rm_spillblk)); 787 memcpy(ndn->dn_next_bonuslen, odn->dn_next_bonuslen, 788 sizeof (odn->dn_next_bonuslen)); 789 memcpy(ndn->dn_next_blksz, odn->dn_next_blksz, 790 sizeof (odn->dn_next_blksz)); 791 memcpy(ndn->dn_next_maxblkid, odn->dn_next_maxblkid, 792 sizeof (odn->dn_next_maxblkid)); 793 for (int i = 0; i < TXG_SIZE; i++) { 794 list_move_tail(&ndn->dn_dirty_records[i], 795 &odn->dn_dirty_records[i]); 796 } 797 memcpy(ndn->dn_free_ranges, odn->dn_free_ranges, 798 sizeof (odn->dn_free_ranges)); 799 ndn->dn_allocated_txg = odn->dn_allocated_txg; 800 ndn->dn_free_txg = odn->dn_free_txg; 801 ndn->dn_assigned_txg = odn->dn_assigned_txg; 802 ndn->dn_dirty_txg = odn->dn_dirty_txg; 803 ndn->dn_dirtyctx = odn->dn_dirtyctx; 804 ndn->dn_dirtyctx_firstset = odn->dn_dirtyctx_firstset; 805 ASSERT(zfs_refcount_count(&odn->dn_tx_holds) == 0); 806 zfs_refcount_transfer(&ndn->dn_holds, &odn->dn_holds); 807 ASSERT(avl_is_empty(&ndn->dn_dbufs)); 808 avl_swap(&ndn->dn_dbufs, &odn->dn_dbufs); 809 ndn->dn_dbufs_count = odn->dn_dbufs_count; 810 ndn->dn_bonus = odn->dn_bonus; 811 ndn->dn_have_spill = odn->dn_have_spill; 812 ndn->dn_zio = odn->dn_zio; 813 ndn->dn_oldused = odn->dn_oldused; 814 ndn->dn_oldflags = odn->dn_oldflags; 815 ndn->dn_olduid = odn->dn_olduid; 816 ndn->dn_oldgid = odn->dn_oldgid; 817 ndn->dn_oldprojid = odn->dn_oldprojid; 818 ndn->dn_newuid = odn->dn_newuid; 819 ndn->dn_newgid = odn->dn_newgid; 820 ndn->dn_newprojid = odn->dn_newprojid; 821 ndn->dn_id_flags = odn->dn_id_flags; 822 dmu_zfetch_init(&ndn->dn_zfetch, ndn); 823 824 /* 825 * Update back pointers. Updating the handle fixes the back pointer of 826 * every descendant dbuf as well as the bonus dbuf. 827 */ 828 ASSERT(ndn->dn_handle->dnh_dnode == odn); 829 ndn->dn_handle->dnh_dnode = ndn; 830 831 /* 832 * Invalidate the original dnode by clearing all of its back pointers. 833 */ 834 odn->dn_dbuf = NULL; 835 odn->dn_handle = NULL; 836 avl_create(&odn->dn_dbufs, dbuf_compare, sizeof (dmu_buf_impl_t), 837 offsetof(dmu_buf_impl_t, db_link)); 838 odn->dn_dbufs_count = 0; 839 odn->dn_bonus = NULL; 840 dmu_zfetch_fini(&odn->dn_zfetch); 841 842 /* 843 * Set the low bit of the objset pointer to ensure that dnode_move() 844 * recognizes the dnode as invalid in any subsequent callback. 845 */ 846 POINTER_INVALIDATE(&odn->dn_objset); 847 848 /* 849 * Satisfy the destructor. 850 */ 851 for (int i = 0; i < TXG_SIZE; i++) { 852 list_create(&odn->dn_dirty_records[i], 853 sizeof (dbuf_dirty_record_t), 854 offsetof(dbuf_dirty_record_t, dr_dirty_node)); 855 odn->dn_free_ranges[i] = NULL; 856 odn->dn_next_nlevels[i] = 0; 857 odn->dn_next_indblkshift[i] = 0; 858 odn->dn_next_bonustype[i] = 0; 859 odn->dn_rm_spillblk[i] = 0; 860 odn->dn_next_bonuslen[i] = 0; 861 odn->dn_next_blksz[i] = 0; 862 } 863 odn->dn_allocated_txg = 0; 864 odn->dn_free_txg = 0; 865 odn->dn_assigned_txg = 0; 866 odn->dn_dirty_txg = 0; 867 odn->dn_dirtyctx = 0; 868 odn->dn_dirtyctx_firstset = NULL; 869 odn->dn_have_spill = B_FALSE; 870 odn->dn_zio = NULL; 871 odn->dn_oldused = 0; 872 odn->dn_oldflags = 0; 873 odn->dn_olduid = 0; 874 odn->dn_oldgid = 0; 875 odn->dn_oldprojid = ZFS_DEFAULT_PROJID; 876 odn->dn_newuid = 0; 877 odn->dn_newgid = 0; 878 odn->dn_newprojid = ZFS_DEFAULT_PROJID; 879 odn->dn_id_flags = 0; 880 881 /* 882 * Mark the dnode. 883 */ 884 ndn->dn_moved = 1; 885 odn->dn_moved = (uint8_t)-1; 886 } 887 888 static kmem_cbrc_t 889 dnode_move(void *buf, void *newbuf, size_t size, void *arg) 890 { 891 dnode_t *odn = buf, *ndn = newbuf; 892 objset_t *os; 893 int64_t refcount; 894 uint32_t dbufs; 895 896 /* 897 * The dnode is on the objset's list of known dnodes if the objset 898 * pointer is valid. We set the low bit of the objset pointer when 899 * freeing the dnode to invalidate it, and the memory patterns written 900 * by kmem (baddcafe and deadbeef) set at least one of the two low bits. 901 * A newly created dnode sets the objset pointer last of all to indicate 902 * that the dnode is known and in a valid state to be moved by this 903 * function. 904 */ 905 os = odn->dn_objset; 906 if (!POINTER_IS_VALID(os)) { 907 DNODE_STAT_BUMP(dnode_move_invalid); 908 return (KMEM_CBRC_DONT_KNOW); 909 } 910 911 /* 912 * Ensure that the objset does not go away during the move. 913 */ 914 rw_enter(&os_lock, RW_WRITER); 915 if (os != odn->dn_objset) { 916 rw_exit(&os_lock); 917 DNODE_STAT_BUMP(dnode_move_recheck1); 918 return (KMEM_CBRC_DONT_KNOW); 919 } 920 921 /* 922 * If the dnode is still valid, then so is the objset. We know that no 923 * valid objset can be freed while we hold os_lock, so we can safely 924 * ensure that the objset remains in use. 925 */ 926 mutex_enter(&os->os_lock); 927 928 /* 929 * Recheck the objset pointer in case the dnode was removed just before 930 * acquiring the lock. 931 */ 932 if (os != odn->dn_objset) { 933 mutex_exit(&os->os_lock); 934 rw_exit(&os_lock); 935 DNODE_STAT_BUMP(dnode_move_recheck2); 936 return (KMEM_CBRC_DONT_KNOW); 937 } 938 939 /* 940 * At this point we know that as long as we hold os->os_lock, the dnode 941 * cannot be freed and fields within the dnode can be safely accessed. 942 * The objset listing this dnode cannot go away as long as this dnode is 943 * on its list. 944 */ 945 rw_exit(&os_lock); 946 if (DMU_OBJECT_IS_SPECIAL(odn->dn_object)) { 947 mutex_exit(&os->os_lock); 948 DNODE_STAT_BUMP(dnode_move_special); 949 return (KMEM_CBRC_NO); 950 } 951 ASSERT(odn->dn_dbuf != NULL); /* only "special" dnodes have no parent */ 952 953 /* 954 * Lock the dnode handle to prevent the dnode from obtaining any new 955 * holds. This also prevents the descendant dbufs and the bonus dbuf 956 * from accessing the dnode, so that we can discount their holds. The 957 * handle is safe to access because we know that while the dnode cannot 958 * go away, neither can its handle. Once we hold dnh_zrlock, we can 959 * safely move any dnode referenced only by dbufs. 960 */ 961 if (!zrl_tryenter(&odn->dn_handle->dnh_zrlock)) { 962 mutex_exit(&os->os_lock); 963 DNODE_STAT_BUMP(dnode_move_handle); 964 return (KMEM_CBRC_LATER); 965 } 966 967 /* 968 * Ensure a consistent view of the dnode's holds and the dnode's dbufs. 969 * We need to guarantee that there is a hold for every dbuf in order to 970 * determine whether the dnode is actively referenced. Falsely matching 971 * a dbuf to an active hold would lead to an unsafe move. It's possible 972 * that a thread already having an active dnode hold is about to add a 973 * dbuf, and we can't compare hold and dbuf counts while the add is in 974 * progress. 975 */ 976 if (!rw_tryenter(&odn->dn_struct_rwlock, RW_WRITER)) { 977 zrl_exit(&odn->dn_handle->dnh_zrlock); 978 mutex_exit(&os->os_lock); 979 DNODE_STAT_BUMP(dnode_move_rwlock); 980 return (KMEM_CBRC_LATER); 981 } 982 983 /* 984 * A dbuf may be removed (evicted) without an active dnode hold. In that 985 * case, the dbuf count is decremented under the handle lock before the 986 * dbuf's hold is released. This order ensures that if we count the hold 987 * after the dbuf is removed but before its hold is released, we will 988 * treat the unmatched hold as active and exit safely. If we count the 989 * hold before the dbuf is removed, the hold is discounted, and the 990 * removal is blocked until the move completes. 991 */ 992 refcount = zfs_refcount_count(&odn->dn_holds); 993 ASSERT(refcount >= 0); 994 dbufs = DN_DBUFS_COUNT(odn); 995 996 /* We can't have more dbufs than dnode holds. */ 997 ASSERT3U(dbufs, <=, refcount); 998 DTRACE_PROBE3(dnode__move, dnode_t *, odn, int64_t, refcount, 999 uint32_t, dbufs); 1000 1001 if (refcount > dbufs) { 1002 rw_exit(&odn->dn_struct_rwlock); 1003 zrl_exit(&odn->dn_handle->dnh_zrlock); 1004 mutex_exit(&os->os_lock); 1005 DNODE_STAT_BUMP(dnode_move_active); 1006 return (KMEM_CBRC_LATER); 1007 } 1008 1009 rw_exit(&odn->dn_struct_rwlock); 1010 1011 /* 1012 * At this point we know that anyone with a hold on the dnode is not 1013 * actively referencing it. The dnode is known and in a valid state to 1014 * move. We're holding the locks needed to execute the critical section. 1015 */ 1016 dnode_move_impl(odn, ndn); 1017 1018 list_link_replace(&odn->dn_link, &ndn->dn_link); 1019 /* If the dnode was safe to move, the refcount cannot have changed. */ 1020 ASSERT(refcount == zfs_refcount_count(&ndn->dn_holds)); 1021 ASSERT(dbufs == DN_DBUFS_COUNT(ndn)); 1022 zrl_exit(&ndn->dn_handle->dnh_zrlock); /* handle has moved */ 1023 mutex_exit(&os->os_lock); 1024 1025 return (KMEM_CBRC_YES); 1026 } 1027 #endif /* _KERNEL */ 1028 1029 static void 1030 dnode_slots_hold(dnode_children_t *children, int idx, int slots) 1031 { 1032 ASSERT3S(idx + slots, <=, DNODES_PER_BLOCK); 1033 1034 for (int i = idx; i < idx + slots; i++) { 1035 dnode_handle_t *dnh = &children->dnc_children[i]; 1036 zrl_add(&dnh->dnh_zrlock); 1037 } 1038 } 1039 1040 static void 1041 dnode_slots_rele(dnode_children_t *children, int idx, int slots) 1042 { 1043 ASSERT3S(idx + slots, <=, DNODES_PER_BLOCK); 1044 1045 for (int i = idx; i < idx + slots; i++) { 1046 dnode_handle_t *dnh = &children->dnc_children[i]; 1047 1048 if (zrl_is_locked(&dnh->dnh_zrlock)) 1049 zrl_exit(&dnh->dnh_zrlock); 1050 else 1051 zrl_remove(&dnh->dnh_zrlock); 1052 } 1053 } 1054 1055 static int 1056 dnode_slots_tryenter(dnode_children_t *children, int idx, int slots) 1057 { 1058 ASSERT3S(idx + slots, <=, DNODES_PER_BLOCK); 1059 1060 for (int i = idx; i < idx + slots; i++) { 1061 dnode_handle_t *dnh = &children->dnc_children[i]; 1062 1063 if (!zrl_tryenter(&dnh->dnh_zrlock)) { 1064 for (int j = idx; j < i; j++) { 1065 dnh = &children->dnc_children[j]; 1066 zrl_exit(&dnh->dnh_zrlock); 1067 } 1068 1069 return (0); 1070 } 1071 } 1072 1073 return (1); 1074 } 1075 1076 static void 1077 dnode_set_slots(dnode_children_t *children, int idx, int slots, void *ptr) 1078 { 1079 ASSERT3S(idx + slots, <=, DNODES_PER_BLOCK); 1080 1081 for (int i = idx; i < idx + slots; i++) { 1082 dnode_handle_t *dnh = &children->dnc_children[i]; 1083 dnh->dnh_dnode = ptr; 1084 } 1085 } 1086 1087 static boolean_t 1088 dnode_check_slots_free(dnode_children_t *children, int idx, int slots) 1089 { 1090 ASSERT3S(idx + slots, <=, DNODES_PER_BLOCK); 1091 1092 /* 1093 * If all dnode slots are either already free or 1094 * evictable return B_TRUE. 1095 */ 1096 for (int i = idx; i < idx + slots; i++) { 1097 dnode_handle_t *dnh = &children->dnc_children[i]; 1098 dnode_t *dn = dnh->dnh_dnode; 1099 1100 if (dn == DN_SLOT_FREE) { 1101 continue; 1102 } else if (DN_SLOT_IS_PTR(dn)) { 1103 mutex_enter(&dn->dn_mtx); 1104 boolean_t can_free = (dn->dn_type == DMU_OT_NONE && 1105 zfs_refcount_is_zero(&dn->dn_holds) && 1106 !DNODE_IS_DIRTY(dn)); 1107 mutex_exit(&dn->dn_mtx); 1108 1109 if (!can_free) 1110 return (B_FALSE); 1111 else 1112 continue; 1113 } else { 1114 return (B_FALSE); 1115 } 1116 } 1117 1118 return (B_TRUE); 1119 } 1120 1121 static void 1122 dnode_reclaim_slots(dnode_children_t *children, int idx, int slots) 1123 { 1124 ASSERT3S(idx + slots, <=, DNODES_PER_BLOCK); 1125 1126 for (int i = idx; i < idx + slots; i++) { 1127 dnode_handle_t *dnh = &children->dnc_children[i]; 1128 1129 ASSERT(zrl_is_locked(&dnh->dnh_zrlock)); 1130 1131 if (DN_SLOT_IS_PTR(dnh->dnh_dnode)) { 1132 ASSERT3S(dnh->dnh_dnode->dn_type, ==, DMU_OT_NONE); 1133 dnode_destroy(dnh->dnh_dnode); 1134 dnh->dnh_dnode = DN_SLOT_FREE; 1135 } 1136 } 1137 } 1138 1139 void 1140 dnode_free_interior_slots(dnode_t *dn) 1141 { 1142 dnode_children_t *children = dmu_buf_get_user(&dn->dn_dbuf->db); 1143 int epb = dn->dn_dbuf->db.db_size >> DNODE_SHIFT; 1144 int idx = (dn->dn_object & (epb - 1)) + 1; 1145 int slots = dn->dn_num_slots - 1; 1146 1147 if (slots == 0) 1148 return; 1149 1150 ASSERT3S(idx + slots, <=, DNODES_PER_BLOCK); 1151 1152 while (!dnode_slots_tryenter(children, idx, slots)) { 1153 DNODE_STAT_BUMP(dnode_free_interior_lock_retry); 1154 cond_resched(); 1155 } 1156 1157 dnode_set_slots(children, idx, slots, DN_SLOT_FREE); 1158 dnode_slots_rele(children, idx, slots); 1159 } 1160 1161 void 1162 dnode_special_close(dnode_handle_t *dnh) 1163 { 1164 dnode_t *dn = dnh->dnh_dnode; 1165 1166 /* 1167 * Ensure dnode_rele_and_unlock() has released dn_mtx, after final 1168 * zfs_refcount_remove() 1169 */ 1170 mutex_enter(&dn->dn_mtx); 1171 if (zfs_refcount_count(&dn->dn_holds) > 0) 1172 cv_wait(&dn->dn_nodnholds, &dn->dn_mtx); 1173 mutex_exit(&dn->dn_mtx); 1174 ASSERT3U(zfs_refcount_count(&dn->dn_holds), ==, 0); 1175 1176 ASSERT(dn->dn_dbuf == NULL || 1177 dmu_buf_get_user(&dn->dn_dbuf->db) == NULL); 1178 zrl_add(&dnh->dnh_zrlock); 1179 dnode_destroy(dn); /* implicit zrl_remove() */ 1180 zrl_destroy(&dnh->dnh_zrlock); 1181 dnh->dnh_dnode = NULL; 1182 } 1183 1184 void 1185 dnode_special_open(objset_t *os, dnode_phys_t *dnp, uint64_t object, 1186 dnode_handle_t *dnh) 1187 { 1188 dnode_t *dn; 1189 1190 zrl_init(&dnh->dnh_zrlock); 1191 VERIFY3U(1, ==, zrl_tryenter(&dnh->dnh_zrlock)); 1192 1193 dn = dnode_create(os, dnp, NULL, object, dnh); 1194 DNODE_VERIFY(dn); 1195 1196 zrl_exit(&dnh->dnh_zrlock); 1197 } 1198 1199 static void 1200 dnode_buf_evict_async(void *dbu) 1201 { 1202 dnode_children_t *dnc = dbu; 1203 1204 DNODE_STAT_BUMP(dnode_buf_evict); 1205 1206 for (int i = 0; i < dnc->dnc_count; i++) { 1207 dnode_handle_t *dnh = &dnc->dnc_children[i]; 1208 dnode_t *dn; 1209 1210 /* 1211 * The dnode handle lock guards against the dnode moving to 1212 * another valid address, so there is no need here to guard 1213 * against changes to or from NULL. 1214 */ 1215 if (!DN_SLOT_IS_PTR(dnh->dnh_dnode)) { 1216 zrl_destroy(&dnh->dnh_zrlock); 1217 dnh->dnh_dnode = DN_SLOT_UNINIT; 1218 continue; 1219 } 1220 1221 zrl_add(&dnh->dnh_zrlock); 1222 dn = dnh->dnh_dnode; 1223 /* 1224 * If there are holds on this dnode, then there should 1225 * be holds on the dnode's containing dbuf as well; thus 1226 * it wouldn't be eligible for eviction and this function 1227 * would not have been called. 1228 */ 1229 ASSERT(zfs_refcount_is_zero(&dn->dn_holds)); 1230 ASSERT(zfs_refcount_is_zero(&dn->dn_tx_holds)); 1231 1232 dnode_destroy(dn); /* implicit zrl_remove() for first slot */ 1233 zrl_destroy(&dnh->dnh_zrlock); 1234 dnh->dnh_dnode = DN_SLOT_UNINIT; 1235 } 1236 kmem_free(dnc, sizeof (dnode_children_t) + 1237 dnc->dnc_count * sizeof (dnode_handle_t)); 1238 } 1239 1240 /* 1241 * When the DNODE_MUST_BE_FREE flag is set, the "slots" parameter is used 1242 * to ensure the hole at the specified object offset is large enough to 1243 * hold the dnode being created. The slots parameter is also used to ensure 1244 * a dnode does not span multiple dnode blocks. In both of these cases, if 1245 * a failure occurs, ENOSPC is returned. Keep in mind, these failure cases 1246 * are only possible when using DNODE_MUST_BE_FREE. 1247 * 1248 * If the DNODE_MUST_BE_ALLOCATED flag is set, "slots" must be 0. 1249 * dnode_hold_impl() will check if the requested dnode is already consumed 1250 * as an extra dnode slot by an large dnode, in which case it returns 1251 * ENOENT. 1252 * 1253 * If the DNODE_DRY_RUN flag is set, we don't actually hold the dnode, just 1254 * return whether the hold would succeed or not. tag and dnp should set to 1255 * NULL in this case. 1256 * 1257 * errors: 1258 * EINVAL - Invalid object number or flags. 1259 * ENOSPC - Hole too small to fulfill "slots" request (DNODE_MUST_BE_FREE) 1260 * EEXIST - Refers to an allocated dnode (DNODE_MUST_BE_FREE) 1261 * - Refers to a freeing dnode (DNODE_MUST_BE_FREE) 1262 * - Refers to an interior dnode slot (DNODE_MUST_BE_ALLOCATED) 1263 * ENOENT - The requested dnode is not allocated (DNODE_MUST_BE_ALLOCATED) 1264 * - The requested dnode is being freed (DNODE_MUST_BE_ALLOCATED) 1265 * EIO - I/O error when reading the meta dnode dbuf. 1266 * 1267 * succeeds even for free dnodes. 1268 */ 1269 int 1270 dnode_hold_impl(objset_t *os, uint64_t object, int flag, int slots, 1271 void *tag, dnode_t **dnp) 1272 { 1273 int epb, idx, err; 1274 int drop_struct_lock = FALSE; 1275 int type; 1276 uint64_t blk; 1277 dnode_t *mdn, *dn; 1278 dmu_buf_impl_t *db; 1279 dnode_children_t *dnc; 1280 dnode_phys_t *dn_block; 1281 dnode_handle_t *dnh; 1282 1283 ASSERT(!(flag & DNODE_MUST_BE_ALLOCATED) || (slots == 0)); 1284 ASSERT(!(flag & DNODE_MUST_BE_FREE) || (slots > 0)); 1285 IMPLY(flag & DNODE_DRY_RUN, (tag == NULL) && (dnp == NULL)); 1286 1287 /* 1288 * If you are holding the spa config lock as writer, you shouldn't 1289 * be asking the DMU to do *anything* unless it's the root pool 1290 * which may require us to read from the root filesystem while 1291 * holding some (not all) of the locks as writer. 1292 */ 1293 ASSERT(spa_config_held(os->os_spa, SCL_ALL, RW_WRITER) == 0 || 1294 (spa_is_root(os->os_spa) && 1295 spa_config_held(os->os_spa, SCL_STATE, RW_WRITER))); 1296 1297 ASSERT((flag & DNODE_MUST_BE_ALLOCATED) || (flag & DNODE_MUST_BE_FREE)); 1298 1299 if (object == DMU_USERUSED_OBJECT || object == DMU_GROUPUSED_OBJECT || 1300 object == DMU_PROJECTUSED_OBJECT) { 1301 if (object == DMU_USERUSED_OBJECT) 1302 dn = DMU_USERUSED_DNODE(os); 1303 else if (object == DMU_GROUPUSED_OBJECT) 1304 dn = DMU_GROUPUSED_DNODE(os); 1305 else 1306 dn = DMU_PROJECTUSED_DNODE(os); 1307 if (dn == NULL) 1308 return (SET_ERROR(ENOENT)); 1309 type = dn->dn_type; 1310 if ((flag & DNODE_MUST_BE_ALLOCATED) && type == DMU_OT_NONE) 1311 return (SET_ERROR(ENOENT)); 1312 if ((flag & DNODE_MUST_BE_FREE) && type != DMU_OT_NONE) 1313 return (SET_ERROR(EEXIST)); 1314 DNODE_VERIFY(dn); 1315 /* Don't actually hold if dry run, just return 0 */ 1316 if (!(flag & DNODE_DRY_RUN)) { 1317 (void) zfs_refcount_add(&dn->dn_holds, tag); 1318 *dnp = dn; 1319 } 1320 return (0); 1321 } 1322 1323 if (object == 0 || object >= DN_MAX_OBJECT) 1324 return (SET_ERROR(EINVAL)); 1325 1326 mdn = DMU_META_DNODE(os); 1327 ASSERT(mdn->dn_object == DMU_META_DNODE_OBJECT); 1328 1329 DNODE_VERIFY(mdn); 1330 1331 if (!RW_WRITE_HELD(&mdn->dn_struct_rwlock)) { 1332 rw_enter(&mdn->dn_struct_rwlock, RW_READER); 1333 drop_struct_lock = TRUE; 1334 } 1335 1336 blk = dbuf_whichblock(mdn, 0, object * sizeof (dnode_phys_t)); 1337 db = dbuf_hold(mdn, blk, FTAG); 1338 if (drop_struct_lock) 1339 rw_exit(&mdn->dn_struct_rwlock); 1340 if (db == NULL) { 1341 DNODE_STAT_BUMP(dnode_hold_dbuf_hold); 1342 return (SET_ERROR(EIO)); 1343 } 1344 1345 /* 1346 * We do not need to decrypt to read the dnode so it doesn't matter 1347 * if we get the encrypted or decrypted version. 1348 */ 1349 err = dbuf_read(db, NULL, DB_RF_CANFAIL | 1350 DB_RF_NO_DECRYPT | DB_RF_NOPREFETCH); 1351 if (err) { 1352 DNODE_STAT_BUMP(dnode_hold_dbuf_read); 1353 dbuf_rele(db, FTAG); 1354 return (err); 1355 } 1356 1357 ASSERT3U(db->db.db_size, >=, 1<<DNODE_SHIFT); 1358 epb = db->db.db_size >> DNODE_SHIFT; 1359 1360 idx = object & (epb - 1); 1361 dn_block = (dnode_phys_t *)db->db.db_data; 1362 1363 ASSERT(DB_DNODE(db)->dn_type == DMU_OT_DNODE); 1364 dnc = dmu_buf_get_user(&db->db); 1365 dnh = NULL; 1366 if (dnc == NULL) { 1367 dnode_children_t *winner; 1368 int skip = 0; 1369 1370 dnc = kmem_zalloc(sizeof (dnode_children_t) + 1371 epb * sizeof (dnode_handle_t), KM_SLEEP); 1372 dnc->dnc_count = epb; 1373 dnh = &dnc->dnc_children[0]; 1374 1375 /* Initialize dnode slot status from dnode_phys_t */ 1376 for (int i = 0; i < epb; i++) { 1377 zrl_init(&dnh[i].dnh_zrlock); 1378 1379 if (skip) { 1380 skip--; 1381 continue; 1382 } 1383 1384 if (dn_block[i].dn_type != DMU_OT_NONE) { 1385 int interior = dn_block[i].dn_extra_slots; 1386 1387 dnode_set_slots(dnc, i, 1, DN_SLOT_ALLOCATED); 1388 dnode_set_slots(dnc, i + 1, interior, 1389 DN_SLOT_INTERIOR); 1390 skip = interior; 1391 } else { 1392 dnh[i].dnh_dnode = DN_SLOT_FREE; 1393 skip = 0; 1394 } 1395 } 1396 1397 dmu_buf_init_user(&dnc->dnc_dbu, NULL, 1398 dnode_buf_evict_async, NULL); 1399 winner = dmu_buf_set_user(&db->db, &dnc->dnc_dbu); 1400 if (winner != NULL) { 1401 1402 for (int i = 0; i < epb; i++) 1403 zrl_destroy(&dnh[i].dnh_zrlock); 1404 1405 kmem_free(dnc, sizeof (dnode_children_t) + 1406 epb * sizeof (dnode_handle_t)); 1407 dnc = winner; 1408 } 1409 } 1410 1411 ASSERT(dnc->dnc_count == epb); 1412 1413 if (flag & DNODE_MUST_BE_ALLOCATED) { 1414 slots = 1; 1415 1416 dnode_slots_hold(dnc, idx, slots); 1417 dnh = &dnc->dnc_children[idx]; 1418 1419 if (DN_SLOT_IS_PTR(dnh->dnh_dnode)) { 1420 dn = dnh->dnh_dnode; 1421 } else if (dnh->dnh_dnode == DN_SLOT_INTERIOR) { 1422 DNODE_STAT_BUMP(dnode_hold_alloc_interior); 1423 dnode_slots_rele(dnc, idx, slots); 1424 dbuf_rele(db, FTAG); 1425 return (SET_ERROR(EEXIST)); 1426 } else if (dnh->dnh_dnode != DN_SLOT_ALLOCATED) { 1427 DNODE_STAT_BUMP(dnode_hold_alloc_misses); 1428 dnode_slots_rele(dnc, idx, slots); 1429 dbuf_rele(db, FTAG); 1430 return (SET_ERROR(ENOENT)); 1431 } else { 1432 dnode_slots_rele(dnc, idx, slots); 1433 while (!dnode_slots_tryenter(dnc, idx, slots)) { 1434 DNODE_STAT_BUMP(dnode_hold_alloc_lock_retry); 1435 cond_resched(); 1436 } 1437 1438 /* 1439 * Someone else won the race and called dnode_create() 1440 * after we checked DN_SLOT_IS_PTR() above but before 1441 * we acquired the lock. 1442 */ 1443 if (DN_SLOT_IS_PTR(dnh->dnh_dnode)) { 1444 DNODE_STAT_BUMP(dnode_hold_alloc_lock_misses); 1445 dn = dnh->dnh_dnode; 1446 } else { 1447 dn = dnode_create(os, dn_block + idx, db, 1448 object, dnh); 1449 } 1450 } 1451 1452 mutex_enter(&dn->dn_mtx); 1453 if (dn->dn_type == DMU_OT_NONE || dn->dn_free_txg != 0) { 1454 DNODE_STAT_BUMP(dnode_hold_alloc_type_none); 1455 mutex_exit(&dn->dn_mtx); 1456 dnode_slots_rele(dnc, idx, slots); 1457 dbuf_rele(db, FTAG); 1458 return (SET_ERROR(ENOENT)); 1459 } 1460 1461 /* Don't actually hold if dry run, just return 0 */ 1462 if (flag & DNODE_DRY_RUN) { 1463 mutex_exit(&dn->dn_mtx); 1464 dnode_slots_rele(dnc, idx, slots); 1465 dbuf_rele(db, FTAG); 1466 return (0); 1467 } 1468 1469 DNODE_STAT_BUMP(dnode_hold_alloc_hits); 1470 } else if (flag & DNODE_MUST_BE_FREE) { 1471 1472 if (idx + slots - 1 >= DNODES_PER_BLOCK) { 1473 DNODE_STAT_BUMP(dnode_hold_free_overflow); 1474 dbuf_rele(db, FTAG); 1475 return (SET_ERROR(ENOSPC)); 1476 } 1477 1478 dnode_slots_hold(dnc, idx, slots); 1479 1480 if (!dnode_check_slots_free(dnc, idx, slots)) { 1481 DNODE_STAT_BUMP(dnode_hold_free_misses); 1482 dnode_slots_rele(dnc, idx, slots); 1483 dbuf_rele(db, FTAG); 1484 return (SET_ERROR(ENOSPC)); 1485 } 1486 1487 dnode_slots_rele(dnc, idx, slots); 1488 while (!dnode_slots_tryenter(dnc, idx, slots)) { 1489 DNODE_STAT_BUMP(dnode_hold_free_lock_retry); 1490 cond_resched(); 1491 } 1492 1493 if (!dnode_check_slots_free(dnc, idx, slots)) { 1494 DNODE_STAT_BUMP(dnode_hold_free_lock_misses); 1495 dnode_slots_rele(dnc, idx, slots); 1496 dbuf_rele(db, FTAG); 1497 return (SET_ERROR(ENOSPC)); 1498 } 1499 1500 /* 1501 * Allocated but otherwise free dnodes which would 1502 * be in the interior of a multi-slot dnodes need 1503 * to be freed. Single slot dnodes can be safely 1504 * re-purposed as a performance optimization. 1505 */ 1506 if (slots > 1) 1507 dnode_reclaim_slots(dnc, idx + 1, slots - 1); 1508 1509 dnh = &dnc->dnc_children[idx]; 1510 if (DN_SLOT_IS_PTR(dnh->dnh_dnode)) { 1511 dn = dnh->dnh_dnode; 1512 } else { 1513 dn = dnode_create(os, dn_block + idx, db, 1514 object, dnh); 1515 } 1516 1517 mutex_enter(&dn->dn_mtx); 1518 if (!zfs_refcount_is_zero(&dn->dn_holds) || dn->dn_free_txg) { 1519 DNODE_STAT_BUMP(dnode_hold_free_refcount); 1520 mutex_exit(&dn->dn_mtx); 1521 dnode_slots_rele(dnc, idx, slots); 1522 dbuf_rele(db, FTAG); 1523 return (SET_ERROR(EEXIST)); 1524 } 1525 1526 /* Don't actually hold if dry run, just return 0 */ 1527 if (flag & DNODE_DRY_RUN) { 1528 mutex_exit(&dn->dn_mtx); 1529 dnode_slots_rele(dnc, idx, slots); 1530 dbuf_rele(db, FTAG); 1531 return (0); 1532 } 1533 1534 dnode_set_slots(dnc, idx + 1, slots - 1, DN_SLOT_INTERIOR); 1535 DNODE_STAT_BUMP(dnode_hold_free_hits); 1536 } else { 1537 dbuf_rele(db, FTAG); 1538 return (SET_ERROR(EINVAL)); 1539 } 1540 1541 ASSERT0(dn->dn_free_txg); 1542 1543 if (zfs_refcount_add(&dn->dn_holds, tag) == 1) 1544 dbuf_add_ref(db, dnh); 1545 1546 mutex_exit(&dn->dn_mtx); 1547 1548 /* Now we can rely on the hold to prevent the dnode from moving. */ 1549 dnode_slots_rele(dnc, idx, slots); 1550 1551 DNODE_VERIFY(dn); 1552 ASSERT3P(dnp, !=, NULL); 1553 ASSERT3P(dn->dn_dbuf, ==, db); 1554 ASSERT3U(dn->dn_object, ==, object); 1555 dbuf_rele(db, FTAG); 1556 1557 *dnp = dn; 1558 return (0); 1559 } 1560 1561 /* 1562 * Return held dnode if the object is allocated, NULL if not. 1563 */ 1564 int 1565 dnode_hold(objset_t *os, uint64_t object, void *tag, dnode_t **dnp) 1566 { 1567 return (dnode_hold_impl(os, object, DNODE_MUST_BE_ALLOCATED, 0, tag, 1568 dnp)); 1569 } 1570 1571 /* 1572 * Can only add a reference if there is already at least one 1573 * reference on the dnode. Returns FALSE if unable to add a 1574 * new reference. 1575 */ 1576 boolean_t 1577 dnode_add_ref(dnode_t *dn, void *tag) 1578 { 1579 mutex_enter(&dn->dn_mtx); 1580 if (zfs_refcount_is_zero(&dn->dn_holds)) { 1581 mutex_exit(&dn->dn_mtx); 1582 return (FALSE); 1583 } 1584 VERIFY(1 < zfs_refcount_add(&dn->dn_holds, tag)); 1585 mutex_exit(&dn->dn_mtx); 1586 return (TRUE); 1587 } 1588 1589 void 1590 dnode_rele(dnode_t *dn, void *tag) 1591 { 1592 mutex_enter(&dn->dn_mtx); 1593 dnode_rele_and_unlock(dn, tag, B_FALSE); 1594 } 1595 1596 void 1597 dnode_rele_and_unlock(dnode_t *dn, void *tag, boolean_t evicting) 1598 { 1599 uint64_t refs; 1600 /* Get while the hold prevents the dnode from moving. */ 1601 dmu_buf_impl_t *db = dn->dn_dbuf; 1602 dnode_handle_t *dnh = dn->dn_handle; 1603 1604 refs = zfs_refcount_remove(&dn->dn_holds, tag); 1605 if (refs == 0) 1606 cv_broadcast(&dn->dn_nodnholds); 1607 mutex_exit(&dn->dn_mtx); 1608 /* dnode could get destroyed at this point, so don't use it anymore */ 1609 1610 /* 1611 * It's unsafe to release the last hold on a dnode by dnode_rele() or 1612 * indirectly by dbuf_rele() while relying on the dnode handle to 1613 * prevent the dnode from moving, since releasing the last hold could 1614 * result in the dnode's parent dbuf evicting its dnode handles. For 1615 * that reason anyone calling dnode_rele() or dbuf_rele() without some 1616 * other direct or indirect hold on the dnode must first drop the dnode 1617 * handle. 1618 */ 1619 #ifdef ZFS_DEBUG 1620 ASSERT(refs > 0 || dnh->dnh_zrlock.zr_owner != curthread); 1621 #endif 1622 1623 /* NOTE: the DNODE_DNODE does not have a dn_dbuf */ 1624 if (refs == 0 && db != NULL) { 1625 /* 1626 * Another thread could add a hold to the dnode handle in 1627 * dnode_hold_impl() while holding the parent dbuf. Since the 1628 * hold on the parent dbuf prevents the handle from being 1629 * destroyed, the hold on the handle is OK. We can't yet assert 1630 * that the handle has zero references, but that will be 1631 * asserted anyway when the handle gets destroyed. 1632 */ 1633 mutex_enter(&db->db_mtx); 1634 dbuf_rele_and_unlock(db, dnh, evicting); 1635 } 1636 } 1637 1638 /* 1639 * Test whether we can create a dnode at the specified location. 1640 */ 1641 int 1642 dnode_try_claim(objset_t *os, uint64_t object, int slots) 1643 { 1644 return (dnode_hold_impl(os, object, DNODE_MUST_BE_FREE | DNODE_DRY_RUN, 1645 slots, NULL, NULL)); 1646 } 1647 1648 /* 1649 * Checks if the dnode contains any uncommitted dirty records. 1650 */ 1651 boolean_t 1652 dnode_is_dirty(dnode_t *dn) 1653 { 1654 mutex_enter(&dn->dn_mtx); 1655 1656 for (int i = 0; i < TXG_SIZE; i++) { 1657 if (multilist_link_active(&dn->dn_dirty_link[i])) { 1658 mutex_exit(&dn->dn_mtx); 1659 return (B_TRUE); 1660 } 1661 } 1662 1663 mutex_exit(&dn->dn_mtx); 1664 1665 return (B_FALSE); 1666 } 1667 1668 void 1669 dnode_setdirty(dnode_t *dn, dmu_tx_t *tx) 1670 { 1671 objset_t *os = dn->dn_objset; 1672 uint64_t txg = tx->tx_txg; 1673 1674 if (DMU_OBJECT_IS_SPECIAL(dn->dn_object)) { 1675 dsl_dataset_dirty(os->os_dsl_dataset, tx); 1676 return; 1677 } 1678 1679 DNODE_VERIFY(dn); 1680 1681 #ifdef ZFS_DEBUG 1682 mutex_enter(&dn->dn_mtx); 1683 ASSERT(dn->dn_phys->dn_type || dn->dn_allocated_txg); 1684 ASSERT(dn->dn_free_txg == 0 || dn->dn_free_txg >= txg); 1685 mutex_exit(&dn->dn_mtx); 1686 #endif 1687 1688 /* 1689 * Determine old uid/gid when necessary 1690 */ 1691 dmu_objset_userquota_get_ids(dn, B_TRUE, tx); 1692 1693 multilist_t *dirtylist = &os->os_dirty_dnodes[txg & TXG_MASK]; 1694 multilist_sublist_t *mls = multilist_sublist_lock_obj(dirtylist, dn); 1695 1696 /* 1697 * If we are already marked dirty, we're done. 1698 */ 1699 if (multilist_link_active(&dn->dn_dirty_link[txg & TXG_MASK])) { 1700 multilist_sublist_unlock(mls); 1701 return; 1702 } 1703 1704 ASSERT(!zfs_refcount_is_zero(&dn->dn_holds) || 1705 !avl_is_empty(&dn->dn_dbufs)); 1706 ASSERT(dn->dn_datablksz != 0); 1707 ASSERT0(dn->dn_next_bonuslen[txg & TXG_MASK]); 1708 ASSERT0(dn->dn_next_blksz[txg & TXG_MASK]); 1709 ASSERT0(dn->dn_next_bonustype[txg & TXG_MASK]); 1710 1711 dprintf_ds(os->os_dsl_dataset, "obj=%llu txg=%llu\n", 1712 (u_longlong_t)dn->dn_object, (u_longlong_t)txg); 1713 1714 multilist_sublist_insert_head(mls, dn); 1715 1716 multilist_sublist_unlock(mls); 1717 1718 /* 1719 * The dnode maintains a hold on its containing dbuf as 1720 * long as there are holds on it. Each instantiated child 1721 * dbuf maintains a hold on the dnode. When the last child 1722 * drops its hold, the dnode will drop its hold on the 1723 * containing dbuf. We add a "dirty hold" here so that the 1724 * dnode will hang around after we finish processing its 1725 * children. 1726 */ 1727 VERIFY(dnode_add_ref(dn, (void *)(uintptr_t)tx->tx_txg)); 1728 1729 (void) dbuf_dirty(dn->dn_dbuf, tx); 1730 1731 dsl_dataset_dirty(os->os_dsl_dataset, tx); 1732 } 1733 1734 void 1735 dnode_free(dnode_t *dn, dmu_tx_t *tx) 1736 { 1737 mutex_enter(&dn->dn_mtx); 1738 if (dn->dn_type == DMU_OT_NONE || dn->dn_free_txg) { 1739 mutex_exit(&dn->dn_mtx); 1740 return; 1741 } 1742 dn->dn_free_txg = tx->tx_txg; 1743 mutex_exit(&dn->dn_mtx); 1744 1745 dnode_setdirty(dn, tx); 1746 } 1747 1748 /* 1749 * Try to change the block size for the indicated dnode. This can only 1750 * succeed if there are no blocks allocated or dirty beyond first block 1751 */ 1752 int 1753 dnode_set_blksz(dnode_t *dn, uint64_t size, int ibs, dmu_tx_t *tx) 1754 { 1755 dmu_buf_impl_t *db; 1756 int err; 1757 1758 ASSERT3U(size, <=, spa_maxblocksize(dmu_objset_spa(dn->dn_objset))); 1759 if (size == 0) 1760 size = SPA_MINBLOCKSIZE; 1761 else 1762 size = P2ROUNDUP(size, SPA_MINBLOCKSIZE); 1763 1764 if (ibs == dn->dn_indblkshift) 1765 ibs = 0; 1766 1767 if (size >> SPA_MINBLOCKSHIFT == dn->dn_datablkszsec && ibs == 0) 1768 return (0); 1769 1770 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 1771 1772 /* Check for any allocated blocks beyond the first */ 1773 if (dn->dn_maxblkid != 0) 1774 goto fail; 1775 1776 mutex_enter(&dn->dn_dbufs_mtx); 1777 for (db = avl_first(&dn->dn_dbufs); db != NULL; 1778 db = AVL_NEXT(&dn->dn_dbufs, db)) { 1779 if (db->db_blkid != 0 && db->db_blkid != DMU_BONUS_BLKID && 1780 db->db_blkid != DMU_SPILL_BLKID) { 1781 mutex_exit(&dn->dn_dbufs_mtx); 1782 goto fail; 1783 } 1784 } 1785 mutex_exit(&dn->dn_dbufs_mtx); 1786 1787 if (ibs && dn->dn_nlevels != 1) 1788 goto fail; 1789 1790 /* resize the old block */ 1791 err = dbuf_hold_impl(dn, 0, 0, TRUE, FALSE, FTAG, &db); 1792 if (err == 0) { 1793 dbuf_new_size(db, size, tx); 1794 } else if (err != ENOENT) { 1795 goto fail; 1796 } 1797 1798 dnode_setdblksz(dn, size); 1799 dnode_setdirty(dn, tx); 1800 dn->dn_next_blksz[tx->tx_txg&TXG_MASK] = size; 1801 if (ibs) { 1802 dn->dn_indblkshift = ibs; 1803 dn->dn_next_indblkshift[tx->tx_txg&TXG_MASK] = ibs; 1804 } 1805 /* release after we have fixed the blocksize in the dnode */ 1806 if (db) 1807 dbuf_rele(db, FTAG); 1808 1809 rw_exit(&dn->dn_struct_rwlock); 1810 return (0); 1811 1812 fail: 1813 rw_exit(&dn->dn_struct_rwlock); 1814 return (SET_ERROR(ENOTSUP)); 1815 } 1816 1817 static void 1818 dnode_set_nlevels_impl(dnode_t *dn, int new_nlevels, dmu_tx_t *tx) 1819 { 1820 uint64_t txgoff = tx->tx_txg & TXG_MASK; 1821 int old_nlevels = dn->dn_nlevels; 1822 dmu_buf_impl_t *db; 1823 list_t *list; 1824 dbuf_dirty_record_t *new, *dr, *dr_next; 1825 1826 ASSERT(RW_WRITE_HELD(&dn->dn_struct_rwlock)); 1827 1828 ASSERT3U(new_nlevels, >, dn->dn_nlevels); 1829 dn->dn_nlevels = new_nlevels; 1830 1831 ASSERT3U(new_nlevels, >, dn->dn_next_nlevels[txgoff]); 1832 dn->dn_next_nlevels[txgoff] = new_nlevels; 1833 1834 /* dirty the left indirects */ 1835 db = dbuf_hold_level(dn, old_nlevels, 0, FTAG); 1836 ASSERT(db != NULL); 1837 new = dbuf_dirty(db, tx); 1838 dbuf_rele(db, FTAG); 1839 1840 /* transfer the dirty records to the new indirect */ 1841 mutex_enter(&dn->dn_mtx); 1842 mutex_enter(&new->dt.di.dr_mtx); 1843 list = &dn->dn_dirty_records[txgoff]; 1844 for (dr = list_head(list); dr; dr = dr_next) { 1845 dr_next = list_next(&dn->dn_dirty_records[txgoff], dr); 1846 1847 IMPLY(dr->dr_dbuf == NULL, old_nlevels == 1); 1848 if (dr->dr_dbuf == NULL || 1849 (dr->dr_dbuf->db_level == old_nlevels - 1 && 1850 dr->dr_dbuf->db_blkid != DMU_BONUS_BLKID && 1851 dr->dr_dbuf->db_blkid != DMU_SPILL_BLKID)) { 1852 list_remove(&dn->dn_dirty_records[txgoff], dr); 1853 list_insert_tail(&new->dt.di.dr_children, dr); 1854 dr->dr_parent = new; 1855 } 1856 } 1857 mutex_exit(&new->dt.di.dr_mtx); 1858 mutex_exit(&dn->dn_mtx); 1859 } 1860 1861 int 1862 dnode_set_nlevels(dnode_t *dn, int nlevels, dmu_tx_t *tx) 1863 { 1864 int ret = 0; 1865 1866 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 1867 1868 if (dn->dn_nlevels == nlevels) { 1869 ret = 0; 1870 goto out; 1871 } else if (nlevels < dn->dn_nlevels) { 1872 ret = SET_ERROR(EINVAL); 1873 goto out; 1874 } 1875 1876 dnode_set_nlevels_impl(dn, nlevels, tx); 1877 1878 out: 1879 rw_exit(&dn->dn_struct_rwlock); 1880 return (ret); 1881 } 1882 1883 /* read-holding callers must not rely on the lock being continuously held */ 1884 void 1885 dnode_new_blkid(dnode_t *dn, uint64_t blkid, dmu_tx_t *tx, boolean_t have_read, 1886 boolean_t force) 1887 { 1888 int epbs, new_nlevels; 1889 uint64_t sz; 1890 1891 ASSERT(blkid != DMU_BONUS_BLKID); 1892 1893 ASSERT(have_read ? 1894 RW_READ_HELD(&dn->dn_struct_rwlock) : 1895 RW_WRITE_HELD(&dn->dn_struct_rwlock)); 1896 1897 /* 1898 * if we have a read-lock, check to see if we need to do any work 1899 * before upgrading to a write-lock. 1900 */ 1901 if (have_read) { 1902 if (blkid <= dn->dn_maxblkid) 1903 return; 1904 1905 if (!rw_tryupgrade(&dn->dn_struct_rwlock)) { 1906 rw_exit(&dn->dn_struct_rwlock); 1907 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 1908 } 1909 } 1910 1911 /* 1912 * Raw sends (indicated by the force flag) require that we take the 1913 * given blkid even if the value is lower than the current value. 1914 */ 1915 if (!force && blkid <= dn->dn_maxblkid) 1916 goto out; 1917 1918 /* 1919 * We use the (otherwise unused) top bit of dn_next_maxblkid[txgoff] 1920 * to indicate that this field is set. This allows us to set the 1921 * maxblkid to 0 on an existing object in dnode_sync(). 1922 */ 1923 dn->dn_maxblkid = blkid; 1924 dn->dn_next_maxblkid[tx->tx_txg & TXG_MASK] = 1925 blkid | DMU_NEXT_MAXBLKID_SET; 1926 1927 /* 1928 * Compute the number of levels necessary to support the new maxblkid. 1929 * Raw sends will ensure nlevels is set correctly for us. 1930 */ 1931 new_nlevels = 1; 1932 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT; 1933 for (sz = dn->dn_nblkptr; 1934 sz <= blkid && sz >= dn->dn_nblkptr; sz <<= epbs) 1935 new_nlevels++; 1936 1937 ASSERT3U(new_nlevels, <=, DN_MAX_LEVELS); 1938 1939 if (!force) { 1940 if (new_nlevels > dn->dn_nlevels) 1941 dnode_set_nlevels_impl(dn, new_nlevels, tx); 1942 } else { 1943 ASSERT3U(dn->dn_nlevels, >=, new_nlevels); 1944 } 1945 1946 out: 1947 if (have_read) 1948 rw_downgrade(&dn->dn_struct_rwlock); 1949 } 1950 1951 static void 1952 dnode_dirty_l1(dnode_t *dn, uint64_t l1blkid, dmu_tx_t *tx) 1953 { 1954 dmu_buf_impl_t *db = dbuf_hold_level(dn, 1, l1blkid, FTAG); 1955 if (db != NULL) { 1956 dmu_buf_will_dirty(&db->db, tx); 1957 dbuf_rele(db, FTAG); 1958 } 1959 } 1960 1961 /* 1962 * Dirty all the in-core level-1 dbufs in the range specified by start_blkid 1963 * and end_blkid. 1964 */ 1965 static void 1966 dnode_dirty_l1range(dnode_t *dn, uint64_t start_blkid, uint64_t end_blkid, 1967 dmu_tx_t *tx) 1968 { 1969 dmu_buf_impl_t *db_search; 1970 dmu_buf_impl_t *db; 1971 avl_index_t where; 1972 1973 db_search = kmem_zalloc(sizeof (dmu_buf_impl_t), KM_SLEEP); 1974 1975 mutex_enter(&dn->dn_dbufs_mtx); 1976 1977 db_search->db_level = 1; 1978 db_search->db_blkid = start_blkid + 1; 1979 db_search->db_state = DB_SEARCH; 1980 for (;;) { 1981 1982 db = avl_find(&dn->dn_dbufs, db_search, &where); 1983 if (db == NULL) 1984 db = avl_nearest(&dn->dn_dbufs, where, AVL_AFTER); 1985 1986 if (db == NULL || db->db_level != 1 || 1987 db->db_blkid >= end_blkid) { 1988 break; 1989 } 1990 1991 /* 1992 * Setup the next blkid we want to search for. 1993 */ 1994 db_search->db_blkid = db->db_blkid + 1; 1995 ASSERT3U(db->db_blkid, >=, start_blkid); 1996 1997 /* 1998 * If the dbuf transitions to DB_EVICTING while we're trying 1999 * to dirty it, then we will be unable to discover it in 2000 * the dbuf hash table. This will result in a call to 2001 * dbuf_create() which needs to acquire the dn_dbufs_mtx 2002 * lock. To avoid a deadlock, we drop the lock before 2003 * dirtying the level-1 dbuf. 2004 */ 2005 mutex_exit(&dn->dn_dbufs_mtx); 2006 dnode_dirty_l1(dn, db->db_blkid, tx); 2007 mutex_enter(&dn->dn_dbufs_mtx); 2008 } 2009 2010 #ifdef ZFS_DEBUG 2011 /* 2012 * Walk all the in-core level-1 dbufs and verify they have been dirtied. 2013 */ 2014 db_search->db_level = 1; 2015 db_search->db_blkid = start_blkid + 1; 2016 db_search->db_state = DB_SEARCH; 2017 db = avl_find(&dn->dn_dbufs, db_search, &where); 2018 if (db == NULL) 2019 db = avl_nearest(&dn->dn_dbufs, where, AVL_AFTER); 2020 for (; db != NULL; db = AVL_NEXT(&dn->dn_dbufs, db)) { 2021 if (db->db_level != 1 || db->db_blkid >= end_blkid) 2022 break; 2023 if (db->db_state != DB_EVICTING) 2024 ASSERT(db->db_dirtycnt > 0); 2025 } 2026 #endif 2027 kmem_free(db_search, sizeof (dmu_buf_impl_t)); 2028 mutex_exit(&dn->dn_dbufs_mtx); 2029 } 2030 2031 void 2032 dnode_set_dirtyctx(dnode_t *dn, dmu_tx_t *tx, void *tag) 2033 { 2034 /* 2035 * Don't set dirtyctx to SYNC if we're just modifying this as we 2036 * initialize the objset. 2037 */ 2038 if (dn->dn_dirtyctx == DN_UNDIRTIED) { 2039 dsl_dataset_t *ds = dn->dn_objset->os_dsl_dataset; 2040 2041 if (ds != NULL) { 2042 rrw_enter(&ds->ds_bp_rwlock, RW_READER, tag); 2043 } 2044 if (!BP_IS_HOLE(dn->dn_objset->os_rootbp)) { 2045 if (dmu_tx_is_syncing(tx)) 2046 dn->dn_dirtyctx = DN_DIRTY_SYNC; 2047 else 2048 dn->dn_dirtyctx = DN_DIRTY_OPEN; 2049 dn->dn_dirtyctx_firstset = tag; 2050 } 2051 if (ds != NULL) { 2052 rrw_exit(&ds->ds_bp_rwlock, tag); 2053 } 2054 } 2055 } 2056 2057 static void 2058 dnode_partial_zero(dnode_t *dn, uint64_t off, uint64_t blkoff, uint64_t len, 2059 dmu_tx_t *tx) 2060 { 2061 dmu_buf_impl_t *db; 2062 int res; 2063 2064 rw_enter(&dn->dn_struct_rwlock, RW_READER); 2065 res = dbuf_hold_impl(dn, 0, dbuf_whichblock(dn, 0, off), TRUE, FALSE, 2066 FTAG, &db); 2067 rw_exit(&dn->dn_struct_rwlock); 2068 if (res == 0) { 2069 db_lock_type_t dblt; 2070 boolean_t dirty; 2071 2072 dblt = dmu_buf_lock_parent(db, RW_READER, FTAG); 2073 /* don't dirty if not on disk and not dirty */ 2074 dirty = !list_is_empty(&db->db_dirty_records) || 2075 (db->db_blkptr && !BP_IS_HOLE(db->db_blkptr)); 2076 dmu_buf_unlock_parent(db, dblt, FTAG); 2077 if (dirty) { 2078 caddr_t data; 2079 2080 dmu_buf_will_dirty(&db->db, tx); 2081 data = db->db.db_data; 2082 memset(data + blkoff, 0, len); 2083 } 2084 dbuf_rele(db, FTAG); 2085 } 2086 } 2087 2088 void 2089 dnode_free_range(dnode_t *dn, uint64_t off, uint64_t len, dmu_tx_t *tx) 2090 { 2091 uint64_t blkoff, blkid, nblks; 2092 int blksz, blkshift, head, tail; 2093 int trunc = FALSE; 2094 int epbs; 2095 2096 blksz = dn->dn_datablksz; 2097 blkshift = dn->dn_datablkshift; 2098 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT; 2099 2100 if (len == DMU_OBJECT_END) { 2101 len = UINT64_MAX - off; 2102 trunc = TRUE; 2103 } 2104 2105 /* 2106 * First, block align the region to free: 2107 */ 2108 if (ISP2(blksz)) { 2109 head = P2NPHASE(off, blksz); 2110 blkoff = P2PHASE(off, blksz); 2111 if ((off >> blkshift) > dn->dn_maxblkid) 2112 return; 2113 } else { 2114 ASSERT(dn->dn_maxblkid == 0); 2115 if (off == 0 && len >= blksz) { 2116 /* 2117 * Freeing the whole block; fast-track this request. 2118 */ 2119 blkid = 0; 2120 nblks = 1; 2121 if (dn->dn_nlevels > 1) { 2122 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 2123 dnode_dirty_l1(dn, 0, tx); 2124 rw_exit(&dn->dn_struct_rwlock); 2125 } 2126 goto done; 2127 } else if (off >= blksz) { 2128 /* Freeing past end-of-data */ 2129 return; 2130 } else { 2131 /* Freeing part of the block. */ 2132 head = blksz - off; 2133 ASSERT3U(head, >, 0); 2134 } 2135 blkoff = off; 2136 } 2137 /* zero out any partial block data at the start of the range */ 2138 if (head) { 2139 ASSERT3U(blkoff + head, ==, blksz); 2140 if (len < head) 2141 head = len; 2142 dnode_partial_zero(dn, off, blkoff, head, tx); 2143 off += head; 2144 len -= head; 2145 } 2146 2147 /* If the range was less than one block, we're done */ 2148 if (len == 0) 2149 return; 2150 2151 /* If the remaining range is past end of file, we're done */ 2152 if ((off >> blkshift) > dn->dn_maxblkid) 2153 return; 2154 2155 ASSERT(ISP2(blksz)); 2156 if (trunc) 2157 tail = 0; 2158 else 2159 tail = P2PHASE(len, blksz); 2160 2161 ASSERT0(P2PHASE(off, blksz)); 2162 /* zero out any partial block data at the end of the range */ 2163 if (tail) { 2164 if (len < tail) 2165 tail = len; 2166 dnode_partial_zero(dn, off + len, 0, tail, tx); 2167 len -= tail; 2168 } 2169 2170 /* If the range did not include a full block, we are done */ 2171 if (len == 0) 2172 return; 2173 2174 ASSERT(IS_P2ALIGNED(off, blksz)); 2175 ASSERT(trunc || IS_P2ALIGNED(len, blksz)); 2176 blkid = off >> blkshift; 2177 nblks = len >> blkshift; 2178 if (trunc) 2179 nblks += 1; 2180 2181 /* 2182 * Dirty all the indirect blocks in this range. Note that only 2183 * the first and last indirect blocks can actually be written 2184 * (if they were partially freed) -- they must be dirtied, even if 2185 * they do not exist on disk yet. The interior blocks will 2186 * be freed by free_children(), so they will not actually be written. 2187 * Even though these interior blocks will not be written, we 2188 * dirty them for two reasons: 2189 * 2190 * - It ensures that the indirect blocks remain in memory until 2191 * syncing context. (They have already been prefetched by 2192 * dmu_tx_hold_free(), so we don't have to worry about reading 2193 * them serially here.) 2194 * 2195 * - The dirty space accounting will put pressure on the txg sync 2196 * mechanism to begin syncing, and to delay transactions if there 2197 * is a large amount of freeing. Even though these indirect 2198 * blocks will not be written, we could need to write the same 2199 * amount of space if we copy the freed BPs into deadlists. 2200 */ 2201 if (dn->dn_nlevels > 1) { 2202 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 2203 uint64_t first, last; 2204 2205 first = blkid >> epbs; 2206 dnode_dirty_l1(dn, first, tx); 2207 if (trunc) 2208 last = dn->dn_maxblkid >> epbs; 2209 else 2210 last = (blkid + nblks - 1) >> epbs; 2211 if (last != first) 2212 dnode_dirty_l1(dn, last, tx); 2213 2214 dnode_dirty_l1range(dn, first, last, tx); 2215 2216 int shift = dn->dn_datablkshift + dn->dn_indblkshift - 2217 SPA_BLKPTRSHIFT; 2218 for (uint64_t i = first + 1; i < last; i++) { 2219 /* 2220 * Set i to the blockid of the next non-hole 2221 * level-1 indirect block at or after i. Note 2222 * that dnode_next_offset() operates in terms of 2223 * level-0-equivalent bytes. 2224 */ 2225 uint64_t ibyte = i << shift; 2226 int err = dnode_next_offset(dn, DNODE_FIND_HAVELOCK, 2227 &ibyte, 2, 1, 0); 2228 i = ibyte >> shift; 2229 if (i >= last) 2230 break; 2231 2232 /* 2233 * Normally we should not see an error, either 2234 * from dnode_next_offset() or dbuf_hold_level() 2235 * (except for ESRCH from dnode_next_offset). 2236 * If there is an i/o error, then when we read 2237 * this block in syncing context, it will use 2238 * ZIO_FLAG_MUSTSUCCEED, and thus hang/panic according 2239 * to the "failmode" property. dnode_next_offset() 2240 * doesn't have a flag to indicate MUSTSUCCEED. 2241 */ 2242 if (err != 0) 2243 break; 2244 2245 dnode_dirty_l1(dn, i, tx); 2246 } 2247 rw_exit(&dn->dn_struct_rwlock); 2248 } 2249 2250 done: 2251 /* 2252 * Add this range to the dnode range list. 2253 * We will finish up this free operation in the syncing phase. 2254 */ 2255 mutex_enter(&dn->dn_mtx); 2256 { 2257 int txgoff = tx->tx_txg & TXG_MASK; 2258 if (dn->dn_free_ranges[txgoff] == NULL) { 2259 dn->dn_free_ranges[txgoff] = range_tree_create(NULL, 2260 RANGE_SEG64, NULL, 0, 0); 2261 } 2262 range_tree_clear(dn->dn_free_ranges[txgoff], blkid, nblks); 2263 range_tree_add(dn->dn_free_ranges[txgoff], blkid, nblks); 2264 } 2265 dprintf_dnode(dn, "blkid=%llu nblks=%llu txg=%llu\n", 2266 (u_longlong_t)blkid, (u_longlong_t)nblks, 2267 (u_longlong_t)tx->tx_txg); 2268 mutex_exit(&dn->dn_mtx); 2269 2270 dbuf_free_range(dn, blkid, blkid + nblks - 1, tx); 2271 dnode_setdirty(dn, tx); 2272 } 2273 2274 static boolean_t 2275 dnode_spill_freed(dnode_t *dn) 2276 { 2277 int i; 2278 2279 mutex_enter(&dn->dn_mtx); 2280 for (i = 0; i < TXG_SIZE; i++) { 2281 if (dn->dn_rm_spillblk[i] == DN_KILL_SPILLBLK) 2282 break; 2283 } 2284 mutex_exit(&dn->dn_mtx); 2285 return (i < TXG_SIZE); 2286 } 2287 2288 /* return TRUE if this blkid was freed in a recent txg, or FALSE if it wasn't */ 2289 uint64_t 2290 dnode_block_freed(dnode_t *dn, uint64_t blkid) 2291 { 2292 void *dp = spa_get_dsl(dn->dn_objset->os_spa); 2293 int i; 2294 2295 if (blkid == DMU_BONUS_BLKID) 2296 return (FALSE); 2297 2298 /* 2299 * If we're in the process of opening the pool, dp will not be 2300 * set yet, but there shouldn't be anything dirty. 2301 */ 2302 if (dp == NULL) 2303 return (FALSE); 2304 2305 if (dn->dn_free_txg) 2306 return (TRUE); 2307 2308 if (blkid == DMU_SPILL_BLKID) 2309 return (dnode_spill_freed(dn)); 2310 2311 mutex_enter(&dn->dn_mtx); 2312 for (i = 0; i < TXG_SIZE; i++) { 2313 if (dn->dn_free_ranges[i] != NULL && 2314 range_tree_contains(dn->dn_free_ranges[i], blkid, 1)) 2315 break; 2316 } 2317 mutex_exit(&dn->dn_mtx); 2318 return (i < TXG_SIZE); 2319 } 2320 2321 /* call from syncing context when we actually write/free space for this dnode */ 2322 void 2323 dnode_diduse_space(dnode_t *dn, int64_t delta) 2324 { 2325 uint64_t space; 2326 dprintf_dnode(dn, "dn=%p dnp=%p used=%llu delta=%lld\n", 2327 dn, dn->dn_phys, 2328 (u_longlong_t)dn->dn_phys->dn_used, 2329 (longlong_t)delta); 2330 2331 mutex_enter(&dn->dn_mtx); 2332 space = DN_USED_BYTES(dn->dn_phys); 2333 if (delta > 0) { 2334 ASSERT3U(space + delta, >=, space); /* no overflow */ 2335 } else { 2336 ASSERT3U(space, >=, -delta); /* no underflow */ 2337 } 2338 space += delta; 2339 if (spa_version(dn->dn_objset->os_spa) < SPA_VERSION_DNODE_BYTES) { 2340 ASSERT((dn->dn_phys->dn_flags & DNODE_FLAG_USED_BYTES) == 0); 2341 ASSERT0(P2PHASE(space, 1<<DEV_BSHIFT)); 2342 dn->dn_phys->dn_used = space >> DEV_BSHIFT; 2343 } else { 2344 dn->dn_phys->dn_used = space; 2345 dn->dn_phys->dn_flags |= DNODE_FLAG_USED_BYTES; 2346 } 2347 mutex_exit(&dn->dn_mtx); 2348 } 2349 2350 /* 2351 * Scans a block at the indicated "level" looking for a hole or data, 2352 * depending on 'flags'. 2353 * 2354 * If level > 0, then we are scanning an indirect block looking at its 2355 * pointers. If level == 0, then we are looking at a block of dnodes. 2356 * 2357 * If we don't find what we are looking for in the block, we return ESRCH. 2358 * Otherwise, return with *offset pointing to the beginning (if searching 2359 * forwards) or end (if searching backwards) of the range covered by the 2360 * block pointer we matched on (or dnode). 2361 * 2362 * The basic search algorithm used below by dnode_next_offset() is to 2363 * use this function to search up the block tree (widen the search) until 2364 * we find something (i.e., we don't return ESRCH) and then search back 2365 * down the tree (narrow the search) until we reach our original search 2366 * level. 2367 */ 2368 static int 2369 dnode_next_offset_level(dnode_t *dn, int flags, uint64_t *offset, 2370 int lvl, uint64_t blkfill, uint64_t txg) 2371 { 2372 dmu_buf_impl_t *db = NULL; 2373 void *data = NULL; 2374 uint64_t epbs = dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT; 2375 uint64_t epb = 1ULL << epbs; 2376 uint64_t minfill, maxfill; 2377 boolean_t hole; 2378 int i, inc, error, span; 2379 2380 ASSERT(RW_LOCK_HELD(&dn->dn_struct_rwlock)); 2381 2382 hole = ((flags & DNODE_FIND_HOLE) != 0); 2383 inc = (flags & DNODE_FIND_BACKWARDS) ? -1 : 1; 2384 ASSERT(txg == 0 || !hole); 2385 2386 if (lvl == dn->dn_phys->dn_nlevels) { 2387 error = 0; 2388 epb = dn->dn_phys->dn_nblkptr; 2389 data = dn->dn_phys->dn_blkptr; 2390 } else { 2391 uint64_t blkid = dbuf_whichblock(dn, lvl, *offset); 2392 error = dbuf_hold_impl(dn, lvl, blkid, TRUE, FALSE, FTAG, &db); 2393 if (error) { 2394 if (error != ENOENT) 2395 return (error); 2396 if (hole) 2397 return (0); 2398 /* 2399 * This can only happen when we are searching up 2400 * the block tree for data. We don't really need to 2401 * adjust the offset, as we will just end up looking 2402 * at the pointer to this block in its parent, and its 2403 * going to be unallocated, so we will skip over it. 2404 */ 2405 return (SET_ERROR(ESRCH)); 2406 } 2407 error = dbuf_read(db, NULL, 2408 DB_RF_CANFAIL | DB_RF_HAVESTRUCT | 2409 DB_RF_NO_DECRYPT | DB_RF_NOPREFETCH); 2410 if (error) { 2411 dbuf_rele(db, FTAG); 2412 return (error); 2413 } 2414 data = db->db.db_data; 2415 rw_enter(&db->db_rwlock, RW_READER); 2416 } 2417 2418 if (db != NULL && txg != 0 && (db->db_blkptr == NULL || 2419 db->db_blkptr->blk_birth <= txg || 2420 BP_IS_HOLE(db->db_blkptr))) { 2421 /* 2422 * This can only happen when we are searching up the tree 2423 * and these conditions mean that we need to keep climbing. 2424 */ 2425 error = SET_ERROR(ESRCH); 2426 } else if (lvl == 0) { 2427 dnode_phys_t *dnp = data; 2428 2429 ASSERT(dn->dn_type == DMU_OT_DNODE); 2430 ASSERT(!(flags & DNODE_FIND_BACKWARDS)); 2431 2432 for (i = (*offset >> DNODE_SHIFT) & (blkfill - 1); 2433 i < blkfill; i += dnp[i].dn_extra_slots + 1) { 2434 if ((dnp[i].dn_type == DMU_OT_NONE) == hole) 2435 break; 2436 } 2437 2438 if (i == blkfill) 2439 error = SET_ERROR(ESRCH); 2440 2441 *offset = (*offset & ~(DNODE_BLOCK_SIZE - 1)) + 2442 (i << DNODE_SHIFT); 2443 } else { 2444 blkptr_t *bp = data; 2445 uint64_t start = *offset; 2446 span = (lvl - 1) * epbs + dn->dn_datablkshift; 2447 minfill = 0; 2448 maxfill = blkfill << ((lvl - 1) * epbs); 2449 2450 if (hole) 2451 maxfill--; 2452 else 2453 minfill++; 2454 2455 if (span >= 8 * sizeof (*offset)) { 2456 /* This only happens on the highest indirection level */ 2457 ASSERT3U((lvl - 1), ==, dn->dn_phys->dn_nlevels - 1); 2458 *offset = 0; 2459 } else { 2460 *offset = *offset >> span; 2461 } 2462 2463 for (i = BF64_GET(*offset, 0, epbs); 2464 i >= 0 && i < epb; i += inc) { 2465 if (BP_GET_FILL(&bp[i]) >= minfill && 2466 BP_GET_FILL(&bp[i]) <= maxfill && 2467 (hole || bp[i].blk_birth > txg)) 2468 break; 2469 if (inc > 0 || *offset > 0) 2470 *offset += inc; 2471 } 2472 2473 if (span >= 8 * sizeof (*offset)) { 2474 *offset = start; 2475 } else { 2476 *offset = *offset << span; 2477 } 2478 2479 if (inc < 0) { 2480 /* traversing backwards; position offset at the end */ 2481 ASSERT3U(*offset, <=, start); 2482 *offset = MIN(*offset + (1ULL << span) - 1, start); 2483 } else if (*offset < start) { 2484 *offset = start; 2485 } 2486 if (i < 0 || i >= epb) 2487 error = SET_ERROR(ESRCH); 2488 } 2489 2490 if (db != NULL) { 2491 rw_exit(&db->db_rwlock); 2492 dbuf_rele(db, FTAG); 2493 } 2494 2495 return (error); 2496 } 2497 2498 /* 2499 * Find the next hole, data, or sparse region at or after *offset. 2500 * The value 'blkfill' tells us how many items we expect to find 2501 * in an L0 data block; this value is 1 for normal objects, 2502 * DNODES_PER_BLOCK for the meta dnode, and some fraction of 2503 * DNODES_PER_BLOCK when searching for sparse regions thereof. 2504 * 2505 * Examples: 2506 * 2507 * dnode_next_offset(dn, flags, offset, 1, 1, 0); 2508 * Finds the next/previous hole/data in a file. 2509 * Used in dmu_offset_next(). 2510 * 2511 * dnode_next_offset(mdn, flags, offset, 0, DNODES_PER_BLOCK, txg); 2512 * Finds the next free/allocated dnode an objset's meta-dnode. 2513 * Only finds objects that have new contents since txg (ie. 2514 * bonus buffer changes and content removal are ignored). 2515 * Used in dmu_object_next(). 2516 * 2517 * dnode_next_offset(mdn, DNODE_FIND_HOLE, offset, 2, DNODES_PER_BLOCK >> 2, 0); 2518 * Finds the next L2 meta-dnode bp that's at most 1/4 full. 2519 * Used in dmu_object_alloc(). 2520 */ 2521 int 2522 dnode_next_offset(dnode_t *dn, int flags, uint64_t *offset, 2523 int minlvl, uint64_t blkfill, uint64_t txg) 2524 { 2525 uint64_t initial_offset = *offset; 2526 int lvl, maxlvl; 2527 int error = 0; 2528 2529 if (!(flags & DNODE_FIND_HAVELOCK)) 2530 rw_enter(&dn->dn_struct_rwlock, RW_READER); 2531 2532 if (dn->dn_phys->dn_nlevels == 0) { 2533 error = SET_ERROR(ESRCH); 2534 goto out; 2535 } 2536 2537 if (dn->dn_datablkshift == 0) { 2538 if (*offset < dn->dn_datablksz) { 2539 if (flags & DNODE_FIND_HOLE) 2540 *offset = dn->dn_datablksz; 2541 } else { 2542 error = SET_ERROR(ESRCH); 2543 } 2544 goto out; 2545 } 2546 2547 maxlvl = dn->dn_phys->dn_nlevels; 2548 2549 for (lvl = minlvl; lvl <= maxlvl; lvl++) { 2550 error = dnode_next_offset_level(dn, 2551 flags, offset, lvl, blkfill, txg); 2552 if (error != ESRCH) 2553 break; 2554 } 2555 2556 while (error == 0 && --lvl >= minlvl) { 2557 error = dnode_next_offset_level(dn, 2558 flags, offset, lvl, blkfill, txg); 2559 } 2560 2561 /* 2562 * There's always a "virtual hole" at the end of the object, even 2563 * if all BP's which physically exist are non-holes. 2564 */ 2565 if ((flags & DNODE_FIND_HOLE) && error == ESRCH && txg == 0 && 2566 minlvl == 1 && blkfill == 1 && !(flags & DNODE_FIND_BACKWARDS)) { 2567 error = 0; 2568 } 2569 2570 if (error == 0 && (flags & DNODE_FIND_BACKWARDS ? 2571 initial_offset < *offset : initial_offset > *offset)) 2572 error = SET_ERROR(ESRCH); 2573 out: 2574 if (!(flags & DNODE_FIND_HAVELOCK)) 2575 rw_exit(&dn->dn_struct_rwlock); 2576 2577 return (error); 2578 } 2579 2580 #if defined(_KERNEL) 2581 EXPORT_SYMBOL(dnode_hold); 2582 EXPORT_SYMBOL(dnode_rele); 2583 EXPORT_SYMBOL(dnode_set_nlevels); 2584 EXPORT_SYMBOL(dnode_set_blksz); 2585 EXPORT_SYMBOL(dnode_free_range); 2586 EXPORT_SYMBOL(dnode_evict_dbufs); 2587 EXPORT_SYMBOL(dnode_evict_bonus); 2588 #endif 2589