1 // SPDX-License-Identifier: CDDL-1.0 2 /* 3 * This file and its contents are supplied under the terms of the 4 * Common Development and Distribution License ("CDDL"), version 1.0. 5 * You may only use this file in accordance with the terms of version 6 * 1.0 of the CDDL. 7 * 8 * A full copy of the text of the CDDL should have accompanied this 9 * source. A copy of the CDDL is also available via the Internet at 10 * https://opensource.org/license/CDDL-1.0. 11 */ 12 /* 13 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. 14 * Copyright (c) 2012, 2020 by Delphix. All rights reserved. 15 * Copyright (c) 2014 Spectra Logic Corporation, All rights reserved. 16 */ 17 18 #include <sys/zfs_context.h> 19 #include <sys/dbuf.h> 20 #include <sys/dnode.h> 21 #include <sys/dmu.h> 22 #include <sys/dmu_impl.h> 23 #include <sys/dmu_tx.h> 24 #include <sys/dmu_objset.h> 25 #include <sys/dsl_dir.h> 26 #include <sys/dsl_dataset.h> 27 #include <sys/spa.h> 28 #include <sys/zio.h> 29 #include <sys/dmu_zfetch.h> 30 #include <sys/range_tree.h> 31 #include <sys/trace_zfs.h> 32 #include <sys/zfs_project.h> 33 34 dnode_stats_t dnode_stats = { 35 { "dnode_hold_dbuf_hold", KSTAT_DATA_UINT64 }, 36 { "dnode_hold_dbuf_read", KSTAT_DATA_UINT64 }, 37 { "dnode_hold_alloc_hits", KSTAT_DATA_UINT64 }, 38 { "dnode_hold_alloc_misses", KSTAT_DATA_UINT64 }, 39 { "dnode_hold_alloc_interior", KSTAT_DATA_UINT64 }, 40 { "dnode_hold_alloc_lock_retry", KSTAT_DATA_UINT64 }, 41 { "dnode_hold_alloc_lock_misses", KSTAT_DATA_UINT64 }, 42 { "dnode_hold_alloc_type_none", KSTAT_DATA_UINT64 }, 43 { "dnode_hold_free_hits", KSTAT_DATA_UINT64 }, 44 { "dnode_hold_free_misses", KSTAT_DATA_UINT64 }, 45 { "dnode_hold_free_lock_misses", KSTAT_DATA_UINT64 }, 46 { "dnode_hold_free_lock_retry", KSTAT_DATA_UINT64 }, 47 { "dnode_hold_free_overflow", KSTAT_DATA_UINT64 }, 48 { "dnode_hold_free_refcount", KSTAT_DATA_UINT64 }, 49 { "dnode_free_interior_lock_retry", KSTAT_DATA_UINT64 }, 50 { "dnode_allocate", KSTAT_DATA_UINT64 }, 51 { "dnode_reallocate", KSTAT_DATA_UINT64 }, 52 { "dnode_buf_evict", KSTAT_DATA_UINT64 }, 53 { "dnode_alloc_next_chunk", KSTAT_DATA_UINT64 }, 54 { "dnode_alloc_race", KSTAT_DATA_UINT64 }, 55 { "dnode_alloc_next_block", KSTAT_DATA_UINT64 }, 56 { "dnode_move_invalid", KSTAT_DATA_UINT64 }, 57 { "dnode_move_recheck1", KSTAT_DATA_UINT64 }, 58 { "dnode_move_recheck2", KSTAT_DATA_UINT64 }, 59 { "dnode_move_special", KSTAT_DATA_UINT64 }, 60 { "dnode_move_handle", KSTAT_DATA_UINT64 }, 61 { "dnode_move_rwlock", KSTAT_DATA_UINT64 }, 62 { "dnode_move_active", KSTAT_DATA_UINT64 }, 63 }; 64 65 dnode_sums_t dnode_sums; 66 67 static kstat_t *dnode_ksp; 68 static kmem_cache_t *dnode_cache; 69 70 static dnode_phys_t dnode_phys_zero __maybe_unused; 71 72 int zfs_default_bs = SPA_MINBLOCKSHIFT; 73 int zfs_default_ibs = DN_MAX_INDBLKSHIFT; 74 75 #ifdef _KERNEL 76 static kmem_cbrc_t dnode_move(void *, void *, size_t, void *); 77 #endif /* _KERNEL */ 78 79 static char * 80 rt_name(dnode_t *dn, const char *name) 81 { 82 struct objset *os = dn->dn_objset; 83 84 return (kmem_asprintf("{spa=%s objset=%llu obj=%llu %s}", 85 spa_name(os->os_spa), 86 (u_longlong_t)(os->os_dsl_dataset ? 87 os->os_dsl_dataset->ds_object : DMU_META_OBJSET), 88 (u_longlong_t)dn->dn_object, 89 name)); 90 } 91 92 static int 93 dbuf_compare(const void *x1, const void *x2) 94 { 95 const dmu_buf_impl_t *d1 = x1; 96 const dmu_buf_impl_t *d2 = x2; 97 98 int cmp = TREE_CMP(d1->db_level, d2->db_level); 99 if (likely(cmp)) 100 return (cmp); 101 102 cmp = TREE_CMP(d1->db_blkid, d2->db_blkid); 103 if (likely(cmp)) 104 return (cmp); 105 106 if (d1->db_state == DB_MARKER) { 107 ASSERT3S(d2->db_state, !=, DB_MARKER); 108 return (TREE_PCMP(d1->db_parent, d2)); 109 } else if (d2->db_state == DB_MARKER) { 110 ASSERT3S(d1->db_state, !=, DB_MARKER); 111 return (TREE_PCMP(d1, d2->db_parent)); 112 } 113 114 if (d1->db_state == DB_SEARCH) { 115 ASSERT3S(d2->db_state, !=, DB_SEARCH); 116 return (-1); 117 } else if (d2->db_state == DB_SEARCH) { 118 ASSERT3S(d1->db_state, !=, DB_SEARCH); 119 return (1); 120 } 121 122 return (TREE_PCMP(d1, d2)); 123 } 124 125 static int 126 dnode_cons(void *arg, void *unused, int kmflag) 127 { 128 (void) unused, (void) kmflag; 129 dnode_t *dn = arg; 130 131 rw_init(&dn->dn_struct_rwlock, NULL, RW_NOLOCKDEP, NULL); 132 mutex_init(&dn->dn_mtx, NULL, MUTEX_DEFAULT, NULL); 133 mutex_init(&dn->dn_dbufs_mtx, NULL, MUTEX_DEFAULT, NULL); 134 cv_init(&dn->dn_notxholds, NULL, CV_DEFAULT, NULL); 135 cv_init(&dn->dn_nodnholds, NULL, CV_DEFAULT, NULL); 136 137 /* 138 * Every dbuf has a reference, and dropping a tracked reference is 139 * O(number of references), so don't track dn_holds. 140 */ 141 zfs_refcount_create_untracked(&dn->dn_holds); 142 zfs_refcount_create(&dn->dn_tx_holds); 143 list_link_init(&dn->dn_link); 144 145 memset(dn->dn_next_type, 0, sizeof (dn->dn_next_type)); 146 memset(dn->dn_next_nblkptr, 0, sizeof (dn->dn_next_nblkptr)); 147 memset(dn->dn_next_nlevels, 0, sizeof (dn->dn_next_nlevels)); 148 memset(dn->dn_next_indblkshift, 0, sizeof (dn->dn_next_indblkshift)); 149 memset(dn->dn_next_bonustype, 0, sizeof (dn->dn_next_bonustype)); 150 memset(dn->dn_rm_spillblk, 0, sizeof (dn->dn_rm_spillblk)); 151 memset(dn->dn_next_bonuslen, 0, sizeof (dn->dn_next_bonuslen)); 152 memset(dn->dn_next_blksz, 0, sizeof (dn->dn_next_blksz)); 153 memset(dn->dn_next_maxblkid, 0, sizeof (dn->dn_next_maxblkid)); 154 155 for (int i = 0; i < TXG_SIZE; i++) { 156 multilist_link_init(&dn->dn_dirty_link[i]); 157 dn->dn_free_ranges[i] = NULL; 158 list_create(&dn->dn_dirty_records[i], 159 sizeof (dbuf_dirty_record_t), 160 offsetof(dbuf_dirty_record_t, dr_dirty_node)); 161 } 162 163 dn->dn_allocated_txg = 0; 164 dn->dn_free_txg = 0; 165 dn->dn_assigned_txg = 0; 166 dn->dn_dirtycnt = 0; 167 dn->dn_bonus = NULL; 168 dn->dn_have_spill = B_FALSE; 169 dn->dn_zio = NULL; 170 dn->dn_oldused = 0; 171 dn->dn_oldflags = 0; 172 dn->dn_olduid = 0; 173 dn->dn_oldgid = 0; 174 dn->dn_oldprojid = ZFS_DEFAULT_PROJID; 175 dn->dn_newuid = 0; 176 dn->dn_newgid = 0; 177 dn->dn_newprojid = ZFS_DEFAULT_PROJID; 178 dn->dn_id_flags = 0; 179 180 dn->dn_dbufs_count = 0; 181 avl_create(&dn->dn_dbufs, dbuf_compare, sizeof (dmu_buf_impl_t), 182 offsetof(dmu_buf_impl_t, db_link)); 183 184 dn->dn_moved = 0; 185 return (0); 186 } 187 188 static void 189 dnode_dest(void *arg, void *unused) 190 { 191 (void) unused; 192 dnode_t *dn = arg; 193 194 rw_destroy(&dn->dn_struct_rwlock); 195 mutex_destroy(&dn->dn_mtx); 196 mutex_destroy(&dn->dn_dbufs_mtx); 197 cv_destroy(&dn->dn_notxholds); 198 cv_destroy(&dn->dn_nodnholds); 199 zfs_refcount_destroy(&dn->dn_holds); 200 zfs_refcount_destroy(&dn->dn_tx_holds); 201 ASSERT(!list_link_active(&dn->dn_link)); 202 203 for (int i = 0; i < TXG_SIZE; i++) { 204 ASSERT(!multilist_link_active(&dn->dn_dirty_link[i])); 205 ASSERT0P(dn->dn_free_ranges[i]); 206 list_destroy(&dn->dn_dirty_records[i]); 207 ASSERT0(dn->dn_next_nblkptr[i]); 208 ASSERT0(dn->dn_next_nlevels[i]); 209 ASSERT0(dn->dn_next_indblkshift[i]); 210 ASSERT0(dn->dn_next_bonustype[i]); 211 ASSERT0(dn->dn_rm_spillblk[i]); 212 ASSERT0(dn->dn_next_bonuslen[i]); 213 ASSERT0(dn->dn_next_blksz[i]); 214 ASSERT0(dn->dn_next_maxblkid[i]); 215 } 216 217 ASSERT0(dn->dn_allocated_txg); 218 ASSERT0(dn->dn_free_txg); 219 ASSERT0(dn->dn_assigned_txg); 220 ASSERT0(dn->dn_dirtycnt); 221 ASSERT0P(dn->dn_bonus); 222 ASSERT(!dn->dn_have_spill); 223 ASSERT0P(dn->dn_zio); 224 ASSERT0(dn->dn_oldused); 225 ASSERT0(dn->dn_oldflags); 226 ASSERT0(dn->dn_olduid); 227 ASSERT0(dn->dn_oldgid); 228 ASSERT0(dn->dn_oldprojid); 229 ASSERT0(dn->dn_newuid); 230 ASSERT0(dn->dn_newgid); 231 ASSERT0(dn->dn_newprojid); 232 ASSERT0(dn->dn_id_flags); 233 234 ASSERT0(dn->dn_dbufs_count); 235 avl_destroy(&dn->dn_dbufs); 236 } 237 238 static int 239 dnode_kstats_update(kstat_t *ksp, int rw) 240 { 241 dnode_stats_t *ds = ksp->ks_data; 242 243 if (rw == KSTAT_WRITE) 244 return (EACCES); 245 ds->dnode_hold_dbuf_hold.value.ui64 = 246 wmsum_value(&dnode_sums.dnode_hold_dbuf_hold); 247 ds->dnode_hold_dbuf_read.value.ui64 = 248 wmsum_value(&dnode_sums.dnode_hold_dbuf_read); 249 ds->dnode_hold_alloc_hits.value.ui64 = 250 wmsum_value(&dnode_sums.dnode_hold_alloc_hits); 251 ds->dnode_hold_alloc_misses.value.ui64 = 252 wmsum_value(&dnode_sums.dnode_hold_alloc_misses); 253 ds->dnode_hold_alloc_interior.value.ui64 = 254 wmsum_value(&dnode_sums.dnode_hold_alloc_interior); 255 ds->dnode_hold_alloc_lock_retry.value.ui64 = 256 wmsum_value(&dnode_sums.dnode_hold_alloc_lock_retry); 257 ds->dnode_hold_alloc_lock_misses.value.ui64 = 258 wmsum_value(&dnode_sums.dnode_hold_alloc_lock_misses); 259 ds->dnode_hold_alloc_type_none.value.ui64 = 260 wmsum_value(&dnode_sums.dnode_hold_alloc_type_none); 261 ds->dnode_hold_free_hits.value.ui64 = 262 wmsum_value(&dnode_sums.dnode_hold_free_hits); 263 ds->dnode_hold_free_misses.value.ui64 = 264 wmsum_value(&dnode_sums.dnode_hold_free_misses); 265 ds->dnode_hold_free_lock_misses.value.ui64 = 266 wmsum_value(&dnode_sums.dnode_hold_free_lock_misses); 267 ds->dnode_hold_free_lock_retry.value.ui64 = 268 wmsum_value(&dnode_sums.dnode_hold_free_lock_retry); 269 ds->dnode_hold_free_refcount.value.ui64 = 270 wmsum_value(&dnode_sums.dnode_hold_free_refcount); 271 ds->dnode_hold_free_overflow.value.ui64 = 272 wmsum_value(&dnode_sums.dnode_hold_free_overflow); 273 ds->dnode_free_interior_lock_retry.value.ui64 = 274 wmsum_value(&dnode_sums.dnode_free_interior_lock_retry); 275 ds->dnode_allocate.value.ui64 = 276 wmsum_value(&dnode_sums.dnode_allocate); 277 ds->dnode_reallocate.value.ui64 = 278 wmsum_value(&dnode_sums.dnode_reallocate); 279 ds->dnode_buf_evict.value.ui64 = 280 wmsum_value(&dnode_sums.dnode_buf_evict); 281 ds->dnode_alloc_next_chunk.value.ui64 = 282 wmsum_value(&dnode_sums.dnode_alloc_next_chunk); 283 ds->dnode_alloc_race.value.ui64 = 284 wmsum_value(&dnode_sums.dnode_alloc_race); 285 ds->dnode_alloc_next_block.value.ui64 = 286 wmsum_value(&dnode_sums.dnode_alloc_next_block); 287 ds->dnode_move_invalid.value.ui64 = 288 wmsum_value(&dnode_sums.dnode_move_invalid); 289 ds->dnode_move_recheck1.value.ui64 = 290 wmsum_value(&dnode_sums.dnode_move_recheck1); 291 ds->dnode_move_recheck2.value.ui64 = 292 wmsum_value(&dnode_sums.dnode_move_recheck2); 293 ds->dnode_move_special.value.ui64 = 294 wmsum_value(&dnode_sums.dnode_move_special); 295 ds->dnode_move_handle.value.ui64 = 296 wmsum_value(&dnode_sums.dnode_move_handle); 297 ds->dnode_move_rwlock.value.ui64 = 298 wmsum_value(&dnode_sums.dnode_move_rwlock); 299 ds->dnode_move_active.value.ui64 = 300 wmsum_value(&dnode_sums.dnode_move_active); 301 return (0); 302 } 303 304 void 305 dnode_init(void) 306 { 307 ASSERT0P(dnode_cache); 308 dnode_cache = kmem_cache_create("dnode_t", sizeof (dnode_t), 309 0, dnode_cons, dnode_dest, NULL, NULL, NULL, KMC_RECLAIMABLE); 310 kmem_cache_set_move(dnode_cache, dnode_move); 311 312 wmsum_init(&dnode_sums.dnode_hold_dbuf_hold, 0); 313 wmsum_init(&dnode_sums.dnode_hold_dbuf_read, 0); 314 wmsum_init(&dnode_sums.dnode_hold_alloc_hits, 0); 315 wmsum_init(&dnode_sums.dnode_hold_alloc_misses, 0); 316 wmsum_init(&dnode_sums.dnode_hold_alloc_interior, 0); 317 wmsum_init(&dnode_sums.dnode_hold_alloc_lock_retry, 0); 318 wmsum_init(&dnode_sums.dnode_hold_alloc_lock_misses, 0); 319 wmsum_init(&dnode_sums.dnode_hold_alloc_type_none, 0); 320 wmsum_init(&dnode_sums.dnode_hold_free_hits, 0); 321 wmsum_init(&dnode_sums.dnode_hold_free_misses, 0); 322 wmsum_init(&dnode_sums.dnode_hold_free_lock_misses, 0); 323 wmsum_init(&dnode_sums.dnode_hold_free_lock_retry, 0); 324 wmsum_init(&dnode_sums.dnode_hold_free_refcount, 0); 325 wmsum_init(&dnode_sums.dnode_hold_free_overflow, 0); 326 wmsum_init(&dnode_sums.dnode_free_interior_lock_retry, 0); 327 wmsum_init(&dnode_sums.dnode_allocate, 0); 328 wmsum_init(&dnode_sums.dnode_reallocate, 0); 329 wmsum_init(&dnode_sums.dnode_buf_evict, 0); 330 wmsum_init(&dnode_sums.dnode_alloc_next_chunk, 0); 331 wmsum_init(&dnode_sums.dnode_alloc_race, 0); 332 wmsum_init(&dnode_sums.dnode_alloc_next_block, 0); 333 wmsum_init(&dnode_sums.dnode_move_invalid, 0); 334 wmsum_init(&dnode_sums.dnode_move_recheck1, 0); 335 wmsum_init(&dnode_sums.dnode_move_recheck2, 0); 336 wmsum_init(&dnode_sums.dnode_move_special, 0); 337 wmsum_init(&dnode_sums.dnode_move_handle, 0); 338 wmsum_init(&dnode_sums.dnode_move_rwlock, 0); 339 wmsum_init(&dnode_sums.dnode_move_active, 0); 340 341 dnode_ksp = kstat_create("zfs", 0, "dnodestats", "misc", 342 KSTAT_TYPE_NAMED, sizeof (dnode_stats) / sizeof (kstat_named_t), 343 KSTAT_FLAG_VIRTUAL); 344 if (dnode_ksp != NULL) { 345 dnode_ksp->ks_data = &dnode_stats; 346 dnode_ksp->ks_update = dnode_kstats_update; 347 kstat_install(dnode_ksp); 348 } 349 } 350 351 void 352 dnode_fini(void) 353 { 354 if (dnode_ksp != NULL) { 355 kstat_delete(dnode_ksp); 356 dnode_ksp = NULL; 357 } 358 359 wmsum_fini(&dnode_sums.dnode_hold_dbuf_hold); 360 wmsum_fini(&dnode_sums.dnode_hold_dbuf_read); 361 wmsum_fini(&dnode_sums.dnode_hold_alloc_hits); 362 wmsum_fini(&dnode_sums.dnode_hold_alloc_misses); 363 wmsum_fini(&dnode_sums.dnode_hold_alloc_interior); 364 wmsum_fini(&dnode_sums.dnode_hold_alloc_lock_retry); 365 wmsum_fini(&dnode_sums.dnode_hold_alloc_lock_misses); 366 wmsum_fini(&dnode_sums.dnode_hold_alloc_type_none); 367 wmsum_fini(&dnode_sums.dnode_hold_free_hits); 368 wmsum_fini(&dnode_sums.dnode_hold_free_misses); 369 wmsum_fini(&dnode_sums.dnode_hold_free_lock_misses); 370 wmsum_fini(&dnode_sums.dnode_hold_free_lock_retry); 371 wmsum_fini(&dnode_sums.dnode_hold_free_refcount); 372 wmsum_fini(&dnode_sums.dnode_hold_free_overflow); 373 wmsum_fini(&dnode_sums.dnode_free_interior_lock_retry); 374 wmsum_fini(&dnode_sums.dnode_allocate); 375 wmsum_fini(&dnode_sums.dnode_reallocate); 376 wmsum_fini(&dnode_sums.dnode_buf_evict); 377 wmsum_fini(&dnode_sums.dnode_alloc_next_chunk); 378 wmsum_fini(&dnode_sums.dnode_alloc_race); 379 wmsum_fini(&dnode_sums.dnode_alloc_next_block); 380 wmsum_fini(&dnode_sums.dnode_move_invalid); 381 wmsum_fini(&dnode_sums.dnode_move_recheck1); 382 wmsum_fini(&dnode_sums.dnode_move_recheck2); 383 wmsum_fini(&dnode_sums.dnode_move_special); 384 wmsum_fini(&dnode_sums.dnode_move_handle); 385 wmsum_fini(&dnode_sums.dnode_move_rwlock); 386 wmsum_fini(&dnode_sums.dnode_move_active); 387 388 kmem_cache_destroy(dnode_cache); 389 dnode_cache = NULL; 390 } 391 392 393 #ifdef ZFS_DEBUG 394 void 395 dnode_verify(dnode_t *dn) 396 { 397 int drop_struct_lock = FALSE; 398 399 ASSERT(dn->dn_phys); 400 ASSERT(dn->dn_objset); 401 ASSERT(dn->dn_handle->dnh_dnode == dn); 402 403 ASSERT(DMU_OT_IS_VALID(dn->dn_phys->dn_type)); 404 405 if (!(zfs_flags & ZFS_DEBUG_DNODE_VERIFY)) 406 return; 407 408 if (!RW_WRITE_HELD(&dn->dn_struct_rwlock)) { 409 rw_enter(&dn->dn_struct_rwlock, RW_READER); 410 drop_struct_lock = TRUE; 411 } 412 if (dn->dn_phys->dn_type != DMU_OT_NONE || dn->dn_allocated_txg != 0) { 413 int i; 414 int max_bonuslen = DN_SLOTS_TO_BONUSLEN(dn->dn_num_slots); 415 ASSERT3U(dn->dn_indblkshift, <=, SPA_MAXBLOCKSHIFT); 416 if (dn->dn_datablkshift) { 417 ASSERT3U(dn->dn_datablkshift, >=, SPA_MINBLOCKSHIFT); 418 ASSERT3U(dn->dn_datablkshift, <=, SPA_MAXBLOCKSHIFT); 419 ASSERT3U(1<<dn->dn_datablkshift, ==, dn->dn_datablksz); 420 } 421 ASSERT3U(dn->dn_nlevels, <=, 30); 422 ASSERT(DMU_OT_IS_VALID(dn->dn_type)); 423 ASSERT3U(dn->dn_nblkptr, >=, 1); 424 ASSERT3U(dn->dn_nblkptr, <=, DN_MAX_NBLKPTR); 425 ASSERT3U(dn->dn_bonuslen, <=, max_bonuslen); 426 ASSERT3U(dn->dn_datablksz, ==, 427 dn->dn_datablkszsec << SPA_MINBLOCKSHIFT); 428 ASSERT3U(ISP2(dn->dn_datablksz), ==, dn->dn_datablkshift != 0); 429 ASSERT3U((dn->dn_nblkptr - 1) * sizeof (blkptr_t) + 430 dn->dn_bonuslen, <=, max_bonuslen); 431 for (i = 0; i < TXG_SIZE; i++) { 432 ASSERT3U(dn->dn_next_nlevels[i], <=, dn->dn_nlevels); 433 } 434 } 435 if (dn->dn_phys->dn_type != DMU_OT_NONE) 436 ASSERT3U(dn->dn_phys->dn_nlevels, <=, dn->dn_nlevels); 437 ASSERT(DMU_OBJECT_IS_SPECIAL(dn->dn_object) || dn->dn_dbuf != NULL); 438 if (dn->dn_dbuf != NULL) { 439 ASSERT3P(dn->dn_phys, ==, 440 (dnode_phys_t *)dn->dn_dbuf->db.db_data + 441 (dn->dn_object % (dn->dn_dbuf->db.db_size >> DNODE_SHIFT))); 442 } 443 if (drop_struct_lock) 444 rw_exit(&dn->dn_struct_rwlock); 445 } 446 #endif 447 448 void 449 dnode_byteswap(dnode_phys_t *dnp) 450 { 451 uint64_t *buf64 = (void*)&dnp->dn_blkptr; 452 int i; 453 454 if (dnp->dn_type == DMU_OT_NONE) { 455 memset(dnp, 0, sizeof (dnode_phys_t)); 456 return; 457 } 458 459 dnp->dn_datablkszsec = BSWAP_16(dnp->dn_datablkszsec); 460 dnp->dn_bonuslen = BSWAP_16(dnp->dn_bonuslen); 461 dnp->dn_extra_slots = BSWAP_8(dnp->dn_extra_slots); 462 dnp->dn_maxblkid = BSWAP_64(dnp->dn_maxblkid); 463 dnp->dn_used = BSWAP_64(dnp->dn_used); 464 465 /* 466 * dn_nblkptr is only one byte, so it's OK to read it in either 467 * byte order. We can't read dn_bouslen. 468 */ 469 ASSERT(dnp->dn_indblkshift <= SPA_MAXBLOCKSHIFT); 470 ASSERT(dnp->dn_nblkptr <= DN_MAX_NBLKPTR); 471 for (i = 0; i < dnp->dn_nblkptr * sizeof (blkptr_t)/8; i++) 472 buf64[i] = BSWAP_64(buf64[i]); 473 474 /* 475 * OK to check dn_bonuslen for zero, because it won't matter if 476 * we have the wrong byte order. This is necessary because the 477 * dnode dnode is smaller than a regular dnode. 478 */ 479 if (dnp->dn_bonuslen != 0) { 480 dmu_object_byteswap_t byteswap; 481 ASSERT(DMU_OT_IS_VALID(dnp->dn_bonustype)); 482 byteswap = DMU_OT_BYTESWAP(dnp->dn_bonustype); 483 dmu_ot_byteswap[byteswap].ob_func(DN_BONUS(dnp), 484 DN_MAX_BONUS_LEN(dnp)); 485 } 486 487 /* Swap SPILL block if we have one */ 488 if (dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) 489 byteswap_uint64_array(DN_SPILL_BLKPTR(dnp), sizeof (blkptr_t)); 490 } 491 492 void 493 dnode_buf_byteswap(void *vbuf, size_t size) 494 { 495 int i = 0; 496 497 ASSERT3U(sizeof (dnode_phys_t), ==, (1<<DNODE_SHIFT)); 498 ASSERT0((size & (sizeof (dnode_phys_t)-1))); 499 500 while (i < size) { 501 dnode_phys_t *dnp = (void *)(((char *)vbuf) + i); 502 dnode_byteswap(dnp); 503 504 i += DNODE_MIN_SIZE; 505 if (dnp->dn_type != DMU_OT_NONE) 506 i += dnp->dn_extra_slots * DNODE_MIN_SIZE; 507 } 508 } 509 510 void 511 dnode_setbonuslen(dnode_t *dn, int newsize, dmu_tx_t *tx) 512 { 513 ASSERT3U(zfs_refcount_count(&dn->dn_holds), >=, 1); 514 515 dnode_setdirty(dn, tx); 516 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 517 ASSERT3U(newsize, <=, DN_SLOTS_TO_BONUSLEN(dn->dn_num_slots) - 518 (dn->dn_nblkptr-1) * sizeof (blkptr_t)); 519 520 if (newsize < dn->dn_bonuslen) { 521 /* clear any data after the end of the new size */ 522 size_t diff = dn->dn_bonuslen - newsize; 523 char *data_end = ((char *)dn->dn_bonus->db.db_data) + newsize; 524 memset(data_end, 0, diff); 525 } 526 527 dn->dn_bonuslen = newsize; 528 if (newsize == 0) 529 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = DN_ZERO_BONUSLEN; 530 else 531 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = dn->dn_bonuslen; 532 rw_exit(&dn->dn_struct_rwlock); 533 } 534 535 void 536 dnode_setbonus_type(dnode_t *dn, dmu_object_type_t newtype, dmu_tx_t *tx) 537 { 538 ASSERT3U(zfs_refcount_count(&dn->dn_holds), >=, 1); 539 dnode_setdirty(dn, tx); 540 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 541 dn->dn_bonustype = newtype; 542 dn->dn_next_bonustype[tx->tx_txg & TXG_MASK] = dn->dn_bonustype; 543 rw_exit(&dn->dn_struct_rwlock); 544 } 545 546 void 547 dnode_set_storage_type(dnode_t *dn, dmu_object_type_t newtype) 548 { 549 /* 550 * This is not in the dnode_phys, but it should be, and perhaps one day 551 * will. For now we require it be set after taking a hold. 552 */ 553 ASSERT3U(zfs_refcount_count(&dn->dn_holds), >=, 1); 554 dn->dn_storage_type = newtype; 555 } 556 557 void 558 dnode_rm_spill(dnode_t *dn, dmu_tx_t *tx) 559 { 560 ASSERT3U(zfs_refcount_count(&dn->dn_holds), >=, 1); 561 ASSERT(RW_WRITE_HELD(&dn->dn_struct_rwlock)); 562 dnode_setdirty(dn, tx); 563 dn->dn_rm_spillblk[tx->tx_txg & TXG_MASK] = DN_KILL_SPILLBLK; 564 dn->dn_have_spill = B_FALSE; 565 } 566 567 static void 568 dnode_setdblksz(dnode_t *dn, int size) 569 { 570 ASSERT0(P2PHASE(size, SPA_MINBLOCKSIZE)); 571 ASSERT3U(size, <=, SPA_MAXBLOCKSIZE); 572 ASSERT3U(size, >=, SPA_MINBLOCKSIZE); 573 ASSERT3U(size >> SPA_MINBLOCKSHIFT, <, 574 1<<(sizeof (dn->dn_phys->dn_datablkszsec) * 8)); 575 dn->dn_datablksz = size; 576 dn->dn_datablkszsec = size >> SPA_MINBLOCKSHIFT; 577 dn->dn_datablkshift = ISP2(size) ? highbit64(size - 1) : 0; 578 } 579 580 static dnode_t * 581 dnode_create(objset_t *os, dnode_phys_t *dnp, dmu_buf_impl_t *db, 582 uint64_t object, dnode_handle_t *dnh) 583 { 584 dnode_t *dn; 585 586 dn = kmem_cache_alloc(dnode_cache, KM_SLEEP); 587 dn->dn_moved = 0; 588 589 /* 590 * Defer setting dn_objset until the dnode is ready to be a candidate 591 * for the dnode_move() callback. 592 */ 593 dn->dn_object = object; 594 dn->dn_dbuf = db; 595 dn->dn_handle = dnh; 596 dn->dn_phys = dnp; 597 598 if (dnp->dn_datablkszsec) { 599 dnode_setdblksz(dn, dnp->dn_datablkszsec << SPA_MINBLOCKSHIFT); 600 } else { 601 dn->dn_datablksz = 0; 602 dn->dn_datablkszsec = 0; 603 dn->dn_datablkshift = 0; 604 } 605 dn->dn_indblkshift = dnp->dn_indblkshift; 606 dn->dn_nlevels = dnp->dn_nlevels; 607 dn->dn_type = dnp->dn_type; 608 dn->dn_nblkptr = dnp->dn_nblkptr; 609 dn->dn_checksum = dnp->dn_checksum; 610 dn->dn_compress = dnp->dn_compress; 611 dn->dn_bonustype = dnp->dn_bonustype; 612 dn->dn_bonuslen = dnp->dn_bonuslen; 613 dn->dn_num_slots = dnp->dn_extra_slots + 1; 614 dn->dn_maxblkid = dnp->dn_maxblkid; 615 dn->dn_have_spill = ((dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) != 0); 616 dn->dn_id_flags = 0; 617 618 dn->dn_storage_type = DMU_OT_NONE; 619 620 dmu_zfetch_init(&dn->dn_zfetch, dn); 621 622 ASSERT(DMU_OT_IS_VALID(dn->dn_phys->dn_type)); 623 ASSERT(zrl_is_locked(&dnh->dnh_zrlock)); 624 ASSERT(!DN_SLOT_IS_PTR(dnh->dnh_dnode)); 625 626 mutex_enter(&os->os_lock); 627 628 /* 629 * Exclude special dnodes from os_dnodes so an empty os_dnodes 630 * signifies that the special dnodes have no references from 631 * their children (the entries in os_dnodes). This allows 632 * dnode_destroy() to easily determine if the last child has 633 * been removed and then complete eviction of the objset. 634 */ 635 if (!DMU_OBJECT_IS_SPECIAL(object)) 636 list_insert_head(&os->os_dnodes, dn); 637 membar_producer(); 638 639 /* 640 * Everything else must be valid before assigning dn_objset 641 * makes the dnode eligible for dnode_move(). 642 */ 643 dn->dn_objset = os; 644 645 dnh->dnh_dnode = dn; 646 mutex_exit(&os->os_lock); 647 648 arc_space_consume(sizeof (dnode_t), ARC_SPACE_DNODE); 649 650 return (dn); 651 } 652 653 /* 654 * Caller must be holding the dnode handle, which is released upon return. 655 */ 656 static void 657 dnode_destroy(dnode_t *dn) 658 { 659 objset_t *os = dn->dn_objset; 660 boolean_t complete_os_eviction = B_FALSE; 661 662 ASSERT0((dn->dn_id_flags & DN_ID_NEW_EXIST)); 663 664 mutex_enter(&os->os_lock); 665 POINTER_INVALIDATE(&dn->dn_objset); 666 if (!DMU_OBJECT_IS_SPECIAL(dn->dn_object)) { 667 list_remove(&os->os_dnodes, dn); 668 complete_os_eviction = 669 list_is_empty(&os->os_dnodes) && 670 list_link_active(&os->os_evicting_node); 671 } 672 mutex_exit(&os->os_lock); 673 674 /* the dnode can no longer move, so we can release the handle */ 675 if (!zrl_is_locked(&dn->dn_handle->dnh_zrlock)) 676 zrl_remove(&dn->dn_handle->dnh_zrlock); 677 678 dn->dn_allocated_txg = 0; 679 dn->dn_free_txg = 0; 680 dn->dn_assigned_txg = 0; 681 dn->dn_dirtycnt = 0; 682 683 if (dn->dn_bonus != NULL) { 684 mutex_enter(&dn->dn_bonus->db_mtx); 685 dbuf_destroy(dn->dn_bonus); 686 dn->dn_bonus = NULL; 687 } 688 dn->dn_zio = NULL; 689 690 dn->dn_have_spill = B_FALSE; 691 dn->dn_oldused = 0; 692 dn->dn_oldflags = 0; 693 dn->dn_olduid = 0; 694 dn->dn_oldgid = 0; 695 dn->dn_oldprojid = ZFS_DEFAULT_PROJID; 696 dn->dn_newuid = 0; 697 dn->dn_newgid = 0; 698 dn->dn_newprojid = ZFS_DEFAULT_PROJID; 699 dn->dn_id_flags = 0; 700 701 dn->dn_storage_type = DMU_OT_NONE; 702 703 dmu_zfetch_fini(&dn->dn_zfetch); 704 kmem_cache_free(dnode_cache, dn); 705 arc_space_return(sizeof (dnode_t), ARC_SPACE_DNODE); 706 707 if (complete_os_eviction) 708 dmu_objset_evict_done(os); 709 } 710 711 void 712 dnode_allocate(dnode_t *dn, dmu_object_type_t ot, int blocksize, int ibs, 713 dmu_object_type_t bonustype, int bonuslen, int dn_slots, dmu_tx_t *tx) 714 { 715 int i; 716 717 ASSERT3U(dn_slots, >, 0); 718 ASSERT3U(dn_slots << DNODE_SHIFT, <=, 719 spa_maxdnodesize(dmu_objset_spa(dn->dn_objset))); 720 ASSERT3U(blocksize, <=, 721 spa_maxblocksize(dmu_objset_spa(dn->dn_objset))); 722 if (blocksize == 0) 723 blocksize = 1 << zfs_default_bs; 724 else 725 blocksize = P2ROUNDUP(blocksize, SPA_MINBLOCKSIZE); 726 727 if (ibs == 0) 728 ibs = zfs_default_ibs; 729 730 ibs = MIN(MAX(ibs, DN_MIN_INDBLKSHIFT), DN_MAX_INDBLKSHIFT); 731 732 dprintf("os=%p obj=%llu txg=%llu blocksize=%d ibs=%d dn_slots=%d\n", 733 dn->dn_objset, (u_longlong_t)dn->dn_object, 734 (u_longlong_t)tx->tx_txg, blocksize, ibs, dn_slots); 735 DNODE_STAT_BUMP(dnode_allocate); 736 737 ASSERT(dn->dn_type == DMU_OT_NONE); 738 ASSERT0(memcmp(dn->dn_phys, &dnode_phys_zero, sizeof (dnode_phys_t))); 739 ASSERT(dn->dn_phys->dn_type == DMU_OT_NONE); 740 ASSERT(ot != DMU_OT_NONE); 741 ASSERT(DMU_OT_IS_VALID(ot)); 742 ASSERT((bonustype == DMU_OT_NONE && bonuslen == 0) || 743 (bonustype == DMU_OT_SA && bonuslen == 0) || 744 (bonustype == DMU_OTN_UINT64_METADATA && bonuslen == 0) || 745 (bonustype != DMU_OT_NONE && bonuslen != 0)); 746 ASSERT(DMU_OT_IS_VALID(bonustype)); 747 ASSERT3U(bonuslen, <=, DN_SLOTS_TO_BONUSLEN(dn_slots)); 748 ASSERT(dn->dn_type == DMU_OT_NONE); 749 ASSERT0(dn->dn_maxblkid); 750 ASSERT0(dn->dn_allocated_txg); 751 ASSERT0(dn->dn_assigned_txg); 752 ASSERT(zfs_refcount_is_zero(&dn->dn_tx_holds)); 753 ASSERT3U(zfs_refcount_count(&dn->dn_holds), <=, 1); 754 ASSERT(avl_is_empty(&dn->dn_dbufs)); 755 756 for (i = 0; i < TXG_SIZE; i++) { 757 ASSERT0(dn->dn_next_nblkptr[i]); 758 ASSERT0(dn->dn_next_nlevels[i]); 759 ASSERT0(dn->dn_next_indblkshift[i]); 760 ASSERT0(dn->dn_next_bonuslen[i]); 761 ASSERT0(dn->dn_next_bonustype[i]); 762 ASSERT0(dn->dn_rm_spillblk[i]); 763 ASSERT0(dn->dn_next_blksz[i]); 764 ASSERT0(dn->dn_next_maxblkid[i]); 765 ASSERT(!multilist_link_active(&dn->dn_dirty_link[i])); 766 ASSERT3P(list_head(&dn->dn_dirty_records[i]), ==, NULL); 767 ASSERT0P(dn->dn_free_ranges[i]); 768 } 769 770 dn->dn_type = ot; 771 dnode_setdblksz(dn, blocksize); 772 dn->dn_indblkshift = ibs; 773 dn->dn_nlevels = 1; 774 dn->dn_num_slots = dn_slots; 775 if (bonustype == DMU_OT_SA) /* Maximize bonus space for SA */ 776 dn->dn_nblkptr = 1; 777 else { 778 /* 779 * Keep in sync with deduce_nblkptr() in dmu_recv.c. 780 */ 781 dn->dn_nblkptr = MIN(DN_MAX_NBLKPTR, 782 1 + ((DN_SLOTS_TO_BONUSLEN(dn_slots) - bonuslen) >> 783 SPA_BLKPTRSHIFT)); 784 } 785 786 dn->dn_bonustype = bonustype; 787 dn->dn_bonuslen = bonuslen; 788 dn->dn_checksum = ZIO_CHECKSUM_INHERIT; 789 dn->dn_compress = ZIO_COMPRESS_INHERIT; 790 791 dn->dn_free_txg = 0; 792 dn->dn_dirtycnt = 0; 793 794 dn->dn_allocated_txg = tx->tx_txg; 795 dn->dn_id_flags = 0; 796 797 dnode_setdirty(dn, tx); 798 dn->dn_next_indblkshift[tx->tx_txg & TXG_MASK] = ibs; 799 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = dn->dn_bonuslen; 800 dn->dn_next_bonustype[tx->tx_txg & TXG_MASK] = dn->dn_bonustype; 801 dn->dn_next_blksz[tx->tx_txg & TXG_MASK] = dn->dn_datablksz; 802 } 803 804 void 805 dnode_reallocate(dnode_t *dn, dmu_object_type_t ot, int blocksize, 806 dmu_object_type_t bonustype, int bonuslen, int dn_slots, 807 boolean_t keep_spill, dmu_tx_t *tx) 808 { 809 int nblkptr; 810 811 ASSERT3U(blocksize, >=, SPA_MINBLOCKSIZE); 812 ASSERT3U(blocksize, <=, 813 spa_maxblocksize(dmu_objset_spa(dn->dn_objset))); 814 ASSERT0(blocksize % SPA_MINBLOCKSIZE); 815 ASSERT(dn->dn_object != DMU_META_DNODE_OBJECT || dmu_tx_private_ok(tx)); 816 ASSERT(tx->tx_txg != 0); 817 ASSERT((bonustype == DMU_OT_NONE && bonuslen == 0) || 818 (bonustype != DMU_OT_NONE && bonuslen != 0) || 819 (bonustype == DMU_OT_SA && bonuslen == 0)); 820 ASSERT(DMU_OT_IS_VALID(bonustype)); 821 ASSERT3U(bonuslen, <=, 822 DN_BONUS_SIZE(spa_maxdnodesize(dmu_objset_spa(dn->dn_objset)))); 823 ASSERT3U(bonuslen, <=, DN_BONUS_SIZE(dn_slots << DNODE_SHIFT)); 824 825 dnode_free_interior_slots(dn); 826 DNODE_STAT_BUMP(dnode_reallocate); 827 828 /* clean up any unreferenced dbufs */ 829 dnode_evict_dbufs(dn); 830 831 dn->dn_id_flags = 0; 832 833 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 834 dnode_setdirty(dn, tx); 835 if (dn->dn_datablksz != blocksize) { 836 /* change blocksize */ 837 ASSERT0(dn->dn_maxblkid); 838 ASSERT(BP_IS_HOLE(&dn->dn_phys->dn_blkptr[0]) || 839 dnode_block_freed(dn, 0)); 840 841 dnode_setdblksz(dn, blocksize); 842 dn->dn_next_blksz[tx->tx_txg & TXG_MASK] = blocksize; 843 } 844 if (dn->dn_bonuslen != bonuslen) 845 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = bonuslen; 846 847 if (bonustype == DMU_OT_SA) /* Maximize bonus space for SA */ 848 nblkptr = 1; 849 else { 850 /* 851 * Keep in sync with deduce_nblkptr() in dmu_recv.c. 852 */ 853 nblkptr = MIN(DN_MAX_NBLKPTR, 854 1 + ((DN_SLOTS_TO_BONUSLEN(dn_slots) - bonuslen) >> 855 SPA_BLKPTRSHIFT)); 856 } 857 if (dn->dn_bonustype != bonustype) 858 dn->dn_next_bonustype[tx->tx_txg & TXG_MASK] = bonustype; 859 if (dn->dn_nblkptr != nblkptr) 860 dn->dn_next_nblkptr[tx->tx_txg & TXG_MASK] = nblkptr; 861 if (dn->dn_phys->dn_flags & DNODE_FLAG_SPILL_BLKPTR && !keep_spill) { 862 dbuf_rm_spill(dn, tx); 863 dnode_rm_spill(dn, tx); 864 } 865 866 rw_exit(&dn->dn_struct_rwlock); 867 868 /* change type */ 869 dn->dn_type = ot; 870 871 /* change bonus size and type */ 872 mutex_enter(&dn->dn_mtx); 873 dn->dn_bonustype = bonustype; 874 dn->dn_bonuslen = bonuslen; 875 dn->dn_num_slots = dn_slots; 876 dn->dn_nblkptr = nblkptr; 877 dn->dn_checksum = ZIO_CHECKSUM_INHERIT; 878 dn->dn_compress = ZIO_COMPRESS_INHERIT; 879 ASSERT3U(dn->dn_nblkptr, <=, DN_MAX_NBLKPTR); 880 881 /* fix up the bonus db_size */ 882 if (dn->dn_bonus) { 883 dn->dn_bonus->db.db_size = 884 DN_SLOTS_TO_BONUSLEN(dn->dn_num_slots) - 885 (dn->dn_nblkptr-1) * sizeof (blkptr_t); 886 ASSERT(dn->dn_bonuslen <= dn->dn_bonus->db.db_size); 887 } 888 889 dn->dn_allocated_txg = tx->tx_txg; 890 mutex_exit(&dn->dn_mtx); 891 } 892 893 #ifdef _KERNEL 894 static void 895 dnode_move_impl(dnode_t *odn, dnode_t *ndn) 896 { 897 ASSERT(!RW_LOCK_HELD(&odn->dn_struct_rwlock)); 898 ASSERT(MUTEX_NOT_HELD(&odn->dn_mtx)); 899 ASSERT(MUTEX_NOT_HELD(&odn->dn_dbufs_mtx)); 900 901 /* Copy fields. */ 902 ndn->dn_objset = odn->dn_objset; 903 ndn->dn_object = odn->dn_object; 904 ndn->dn_dbuf = odn->dn_dbuf; 905 ndn->dn_handle = odn->dn_handle; 906 ndn->dn_phys = odn->dn_phys; 907 ndn->dn_type = odn->dn_type; 908 ndn->dn_bonuslen = odn->dn_bonuslen; 909 ndn->dn_bonustype = odn->dn_bonustype; 910 ndn->dn_nblkptr = odn->dn_nblkptr; 911 ndn->dn_checksum = odn->dn_checksum; 912 ndn->dn_compress = odn->dn_compress; 913 ndn->dn_nlevels = odn->dn_nlevels; 914 ndn->dn_indblkshift = odn->dn_indblkshift; 915 ndn->dn_datablkshift = odn->dn_datablkshift; 916 ndn->dn_datablkszsec = odn->dn_datablkszsec; 917 ndn->dn_datablksz = odn->dn_datablksz; 918 ndn->dn_maxblkid = odn->dn_maxblkid; 919 ndn->dn_num_slots = odn->dn_num_slots; 920 memcpy(ndn->dn_next_type, odn->dn_next_type, 921 sizeof (odn->dn_next_type)); 922 memcpy(ndn->dn_next_nblkptr, odn->dn_next_nblkptr, 923 sizeof (odn->dn_next_nblkptr)); 924 memcpy(ndn->dn_next_nlevels, odn->dn_next_nlevels, 925 sizeof (odn->dn_next_nlevels)); 926 memcpy(ndn->dn_next_indblkshift, odn->dn_next_indblkshift, 927 sizeof (odn->dn_next_indblkshift)); 928 memcpy(ndn->dn_next_bonustype, odn->dn_next_bonustype, 929 sizeof (odn->dn_next_bonustype)); 930 memcpy(ndn->dn_rm_spillblk, odn->dn_rm_spillblk, 931 sizeof (odn->dn_rm_spillblk)); 932 memcpy(ndn->dn_next_bonuslen, odn->dn_next_bonuslen, 933 sizeof (odn->dn_next_bonuslen)); 934 memcpy(ndn->dn_next_blksz, odn->dn_next_blksz, 935 sizeof (odn->dn_next_blksz)); 936 memcpy(ndn->dn_next_maxblkid, odn->dn_next_maxblkid, 937 sizeof (odn->dn_next_maxblkid)); 938 for (int i = 0; i < TXG_SIZE; i++) { 939 list_move_tail(&ndn->dn_dirty_records[i], 940 &odn->dn_dirty_records[i]); 941 } 942 memcpy(ndn->dn_free_ranges, odn->dn_free_ranges, 943 sizeof (odn->dn_free_ranges)); 944 ndn->dn_allocated_txg = odn->dn_allocated_txg; 945 ndn->dn_free_txg = odn->dn_free_txg; 946 ndn->dn_assigned_txg = odn->dn_assigned_txg; 947 ndn->dn_dirtycnt = odn->dn_dirtycnt; 948 ASSERT0(zfs_refcount_count(&odn->dn_tx_holds)); 949 zfs_refcount_transfer(&ndn->dn_holds, &odn->dn_holds); 950 ASSERT(avl_is_empty(&ndn->dn_dbufs)); 951 avl_swap(&ndn->dn_dbufs, &odn->dn_dbufs); 952 ndn->dn_dbufs_count = odn->dn_dbufs_count; 953 ndn->dn_bonus = odn->dn_bonus; 954 ndn->dn_have_spill = odn->dn_have_spill; 955 ndn->dn_zio = odn->dn_zio; 956 ndn->dn_oldused = odn->dn_oldused; 957 ndn->dn_oldflags = odn->dn_oldflags; 958 ndn->dn_olduid = odn->dn_olduid; 959 ndn->dn_oldgid = odn->dn_oldgid; 960 ndn->dn_oldprojid = odn->dn_oldprojid; 961 ndn->dn_newuid = odn->dn_newuid; 962 ndn->dn_newgid = odn->dn_newgid; 963 ndn->dn_newprojid = odn->dn_newprojid; 964 ndn->dn_id_flags = odn->dn_id_flags; 965 ndn->dn_storage_type = odn->dn_storage_type; 966 dmu_zfetch_init(&ndn->dn_zfetch, ndn); 967 968 /* 969 * Update back pointers. Updating the handle fixes the back pointer of 970 * every descendant dbuf as well as the bonus dbuf. 971 */ 972 ASSERT(ndn->dn_handle->dnh_dnode == odn); 973 ndn->dn_handle->dnh_dnode = ndn; 974 975 /* 976 * Invalidate the original dnode by clearing all of its back pointers. 977 */ 978 odn->dn_dbuf = NULL; 979 odn->dn_handle = NULL; 980 avl_create(&odn->dn_dbufs, dbuf_compare, sizeof (dmu_buf_impl_t), 981 offsetof(dmu_buf_impl_t, db_link)); 982 odn->dn_dbufs_count = 0; 983 odn->dn_bonus = NULL; 984 dmu_zfetch_fini(&odn->dn_zfetch); 985 986 /* 987 * Set the low bit of the objset pointer to ensure that dnode_move() 988 * recognizes the dnode as invalid in any subsequent callback. 989 */ 990 POINTER_INVALIDATE(&odn->dn_objset); 991 992 /* 993 * Satisfy the destructor. 994 */ 995 for (int i = 0; i < TXG_SIZE; i++) { 996 list_create(&odn->dn_dirty_records[i], 997 sizeof (dbuf_dirty_record_t), 998 offsetof(dbuf_dirty_record_t, dr_dirty_node)); 999 odn->dn_free_ranges[i] = NULL; 1000 odn->dn_next_nlevels[i] = 0; 1001 odn->dn_next_indblkshift[i] = 0; 1002 odn->dn_next_bonustype[i] = 0; 1003 odn->dn_rm_spillblk[i] = 0; 1004 odn->dn_next_bonuslen[i] = 0; 1005 odn->dn_next_blksz[i] = 0; 1006 } 1007 odn->dn_allocated_txg = 0; 1008 odn->dn_free_txg = 0; 1009 odn->dn_assigned_txg = 0; 1010 odn->dn_dirtycnt = 0; 1011 odn->dn_have_spill = B_FALSE; 1012 odn->dn_zio = NULL; 1013 odn->dn_oldused = 0; 1014 odn->dn_oldflags = 0; 1015 odn->dn_olduid = 0; 1016 odn->dn_oldgid = 0; 1017 odn->dn_oldprojid = ZFS_DEFAULT_PROJID; 1018 odn->dn_newuid = 0; 1019 odn->dn_newgid = 0; 1020 odn->dn_newprojid = ZFS_DEFAULT_PROJID; 1021 odn->dn_id_flags = 0; 1022 odn->dn_storage_type = DMU_OT_NONE; 1023 1024 /* 1025 * Mark the dnode. 1026 */ 1027 ndn->dn_moved = 1; 1028 odn->dn_moved = (uint8_t)-1; 1029 } 1030 1031 static kmem_cbrc_t 1032 dnode_move(void *buf, void *newbuf, size_t size, void *arg) 1033 { 1034 dnode_t *odn = buf, *ndn = newbuf; 1035 objset_t *os; 1036 int64_t refcount; 1037 uint32_t dbufs; 1038 1039 #ifndef USE_DNODE_HANDLE 1040 /* 1041 * We can't move dnodes if dbufs reference them directly without 1042 * using handles and respecitve locking. Unless USE_DNODE_HANDLE 1043 * is defined the code below is only to make sure it still builds, 1044 * but it should never be used, since it is unsafe. 1045 */ 1046 #ifdef ZFS_DEBUG 1047 PANIC("dnode_move() called without USE_DNODE_HANDLE"); 1048 #endif 1049 return (KMEM_CBRC_NO); 1050 #endif 1051 1052 /* 1053 * The dnode is on the objset's list of known dnodes if the objset 1054 * pointer is valid. We set the low bit of the objset pointer when 1055 * freeing the dnode to invalidate it, and the memory patterns written 1056 * by kmem (baddcafe and deadbeef) set at least one of the two low bits. 1057 * A newly created dnode sets the objset pointer last of all to indicate 1058 * that the dnode is known and in a valid state to be moved by this 1059 * function. 1060 */ 1061 os = odn->dn_objset; 1062 if (!POINTER_IS_VALID(os)) { 1063 DNODE_STAT_BUMP(dnode_move_invalid); 1064 return (KMEM_CBRC_DONT_KNOW); 1065 } 1066 1067 /* 1068 * Ensure that the objset does not go away during the move. 1069 */ 1070 rw_enter(&os_lock, RW_WRITER); 1071 if (os != odn->dn_objset) { 1072 rw_exit(&os_lock); 1073 DNODE_STAT_BUMP(dnode_move_recheck1); 1074 return (KMEM_CBRC_DONT_KNOW); 1075 } 1076 1077 /* 1078 * If the dnode is still valid, then so is the objset. We know that no 1079 * valid objset can be freed while we hold os_lock, so we can safely 1080 * ensure that the objset remains in use. 1081 */ 1082 mutex_enter(&os->os_lock); 1083 1084 /* 1085 * Recheck the objset pointer in case the dnode was removed just before 1086 * acquiring the lock. 1087 */ 1088 if (os != odn->dn_objset) { 1089 mutex_exit(&os->os_lock); 1090 rw_exit(&os_lock); 1091 DNODE_STAT_BUMP(dnode_move_recheck2); 1092 return (KMEM_CBRC_DONT_KNOW); 1093 } 1094 1095 /* 1096 * At this point we know that as long as we hold os->os_lock, the dnode 1097 * cannot be freed and fields within the dnode can be safely accessed. 1098 * The objset listing this dnode cannot go away as long as this dnode is 1099 * on its list. 1100 */ 1101 rw_exit(&os_lock); 1102 if (DMU_OBJECT_IS_SPECIAL(odn->dn_object)) { 1103 mutex_exit(&os->os_lock); 1104 DNODE_STAT_BUMP(dnode_move_special); 1105 return (KMEM_CBRC_NO); 1106 } 1107 ASSERT(odn->dn_dbuf != NULL); /* only "special" dnodes have no parent */ 1108 1109 /* 1110 * Lock the dnode handle to prevent the dnode from obtaining any new 1111 * holds. This also prevents the descendant dbufs and the bonus dbuf 1112 * from accessing the dnode, so that we can discount their holds. The 1113 * handle is safe to access because we know that while the dnode cannot 1114 * go away, neither can its handle. Once we hold dnh_zrlock, we can 1115 * safely move any dnode referenced only by dbufs. 1116 */ 1117 if (!zrl_tryenter(&odn->dn_handle->dnh_zrlock)) { 1118 mutex_exit(&os->os_lock); 1119 DNODE_STAT_BUMP(dnode_move_handle); 1120 return (KMEM_CBRC_LATER); 1121 } 1122 1123 /* 1124 * Ensure a consistent view of the dnode's holds and the dnode's dbufs. 1125 * We need to guarantee that there is a hold for every dbuf in order to 1126 * determine whether the dnode is actively referenced. Falsely matching 1127 * a dbuf to an active hold would lead to an unsafe move. It's possible 1128 * that a thread already having an active dnode hold is about to add a 1129 * dbuf, and we can't compare hold and dbuf counts while the add is in 1130 * progress. 1131 */ 1132 if (!rw_tryenter(&odn->dn_struct_rwlock, RW_WRITER)) { 1133 zrl_exit(&odn->dn_handle->dnh_zrlock); 1134 mutex_exit(&os->os_lock); 1135 DNODE_STAT_BUMP(dnode_move_rwlock); 1136 return (KMEM_CBRC_LATER); 1137 } 1138 1139 /* 1140 * A dbuf may be removed (evicted) without an active dnode hold. In that 1141 * case, the dbuf count is decremented under the handle lock before the 1142 * dbuf's hold is released. This order ensures that if we count the hold 1143 * after the dbuf is removed but before its hold is released, we will 1144 * treat the unmatched hold as active and exit safely. If we count the 1145 * hold before the dbuf is removed, the hold is discounted, and the 1146 * removal is blocked until the move completes. 1147 */ 1148 refcount = zfs_refcount_count(&odn->dn_holds); 1149 ASSERT(refcount >= 0); 1150 dbufs = DN_DBUFS_COUNT(odn); 1151 1152 /* We can't have more dbufs than dnode holds. */ 1153 ASSERT3U(dbufs, <=, refcount); 1154 DTRACE_PROBE3(dnode__move, dnode_t *, odn, int64_t, refcount, 1155 uint32_t, dbufs); 1156 1157 if (refcount > dbufs) { 1158 rw_exit(&odn->dn_struct_rwlock); 1159 zrl_exit(&odn->dn_handle->dnh_zrlock); 1160 mutex_exit(&os->os_lock); 1161 DNODE_STAT_BUMP(dnode_move_active); 1162 return (KMEM_CBRC_LATER); 1163 } 1164 1165 rw_exit(&odn->dn_struct_rwlock); 1166 1167 /* 1168 * At this point we know that anyone with a hold on the dnode is not 1169 * actively referencing it. The dnode is known and in a valid state to 1170 * move. We're holding the locks needed to execute the critical section. 1171 */ 1172 dnode_move_impl(odn, ndn); 1173 1174 list_link_replace(&odn->dn_link, &ndn->dn_link); 1175 /* If the dnode was safe to move, the refcount cannot have changed. */ 1176 ASSERT(refcount == zfs_refcount_count(&ndn->dn_holds)); 1177 ASSERT(dbufs == DN_DBUFS_COUNT(ndn)); 1178 zrl_exit(&ndn->dn_handle->dnh_zrlock); /* handle has moved */ 1179 mutex_exit(&os->os_lock); 1180 1181 return (KMEM_CBRC_YES); 1182 } 1183 #endif /* _KERNEL */ 1184 1185 static void 1186 dnode_slots_hold(dnode_children_t *children, int idx, int slots) 1187 { 1188 ASSERT3S(idx + slots, <=, DNODES_PER_BLOCK); 1189 1190 for (int i = idx; i < idx + slots; i++) { 1191 dnode_handle_t *dnh = &children->dnc_children[i]; 1192 zrl_add(&dnh->dnh_zrlock); 1193 } 1194 } 1195 1196 static void 1197 dnode_slots_rele(dnode_children_t *children, int idx, int slots) 1198 { 1199 ASSERT3S(idx + slots, <=, DNODES_PER_BLOCK); 1200 1201 for (int i = idx; i < idx + slots; i++) { 1202 dnode_handle_t *dnh = &children->dnc_children[i]; 1203 1204 if (zrl_is_locked(&dnh->dnh_zrlock)) 1205 zrl_exit(&dnh->dnh_zrlock); 1206 else 1207 zrl_remove(&dnh->dnh_zrlock); 1208 } 1209 } 1210 1211 static int 1212 dnode_slots_tryenter(dnode_children_t *children, int idx, int slots) 1213 { 1214 ASSERT3S(idx + slots, <=, DNODES_PER_BLOCK); 1215 1216 for (int i = idx; i < idx + slots; i++) { 1217 dnode_handle_t *dnh = &children->dnc_children[i]; 1218 1219 if (!zrl_tryenter(&dnh->dnh_zrlock)) { 1220 for (int j = idx; j < i; j++) { 1221 dnh = &children->dnc_children[j]; 1222 zrl_exit(&dnh->dnh_zrlock); 1223 } 1224 1225 return (0); 1226 } 1227 } 1228 1229 return (1); 1230 } 1231 1232 static void 1233 dnode_set_slots(dnode_children_t *children, int idx, int slots, void *ptr) 1234 { 1235 ASSERT3S(idx + slots, <=, DNODES_PER_BLOCK); 1236 1237 for (int i = idx; i < idx + slots; i++) { 1238 dnode_handle_t *dnh = &children->dnc_children[i]; 1239 dnh->dnh_dnode = ptr; 1240 } 1241 } 1242 1243 static boolean_t 1244 dnode_check_slots_free(dnode_children_t *children, int idx, int slots) 1245 { 1246 ASSERT3S(idx + slots, <=, DNODES_PER_BLOCK); 1247 1248 /* 1249 * If all dnode slots are either already free or 1250 * evictable return B_TRUE. 1251 */ 1252 for (int i = idx; i < idx + slots; i++) { 1253 dnode_handle_t *dnh = &children->dnc_children[i]; 1254 dnode_t *dn = dnh->dnh_dnode; 1255 1256 if (dn == DN_SLOT_FREE) { 1257 continue; 1258 } else if (DN_SLOT_IS_PTR(dn)) { 1259 mutex_enter(&dn->dn_mtx); 1260 boolean_t can_free = (dn->dn_type == DMU_OT_NONE && 1261 dn->dn_dirtycnt == 0 && 1262 zfs_refcount_is_zero(&dn->dn_holds)); 1263 mutex_exit(&dn->dn_mtx); 1264 1265 if (!can_free) 1266 return (B_FALSE); 1267 else 1268 continue; 1269 } else { 1270 return (B_FALSE); 1271 } 1272 } 1273 1274 return (B_TRUE); 1275 } 1276 1277 static uint_t 1278 dnode_reclaim_slots(dnode_children_t *children, int idx, int slots) 1279 { 1280 uint_t reclaimed = 0; 1281 1282 ASSERT3S(idx + slots, <=, DNODES_PER_BLOCK); 1283 1284 for (int i = idx; i < idx + slots; i++) { 1285 dnode_handle_t *dnh = &children->dnc_children[i]; 1286 1287 ASSERT(zrl_is_locked(&dnh->dnh_zrlock)); 1288 1289 if (DN_SLOT_IS_PTR(dnh->dnh_dnode)) { 1290 ASSERT3S(dnh->dnh_dnode->dn_type, ==, DMU_OT_NONE); 1291 dnode_destroy(dnh->dnh_dnode); 1292 dnh->dnh_dnode = DN_SLOT_FREE; 1293 reclaimed++; 1294 } 1295 } 1296 1297 return (reclaimed); 1298 } 1299 1300 void 1301 dnode_free_interior_slots(dnode_t *dn) 1302 { 1303 dnode_children_t *children = dmu_buf_get_user(&dn->dn_dbuf->db); 1304 int epb = dn->dn_dbuf->db.db_size >> DNODE_SHIFT; 1305 int idx = (dn->dn_object & (epb - 1)) + 1; 1306 int slots = dn->dn_num_slots - 1; 1307 1308 if (slots == 0) 1309 return; 1310 1311 ASSERT3S(idx + slots, <=, DNODES_PER_BLOCK); 1312 1313 while (!dnode_slots_tryenter(children, idx, slots)) { 1314 DNODE_STAT_BUMP(dnode_free_interior_lock_retry); 1315 kpreempt(KPREEMPT_SYNC); 1316 } 1317 1318 dnode_set_slots(children, idx, slots, DN_SLOT_FREE); 1319 dnode_slots_rele(children, idx, slots); 1320 } 1321 1322 void 1323 dnode_special_close(dnode_handle_t *dnh) 1324 { 1325 dnode_t *dn = dnh->dnh_dnode; 1326 1327 /* 1328 * Ensure dnode_rele_and_unlock() has released dn_mtx, after final 1329 * zfs_refcount_remove() 1330 */ 1331 mutex_enter(&dn->dn_mtx); 1332 if (zfs_refcount_count(&dn->dn_holds) > 0) 1333 cv_wait(&dn->dn_nodnholds, &dn->dn_mtx); 1334 mutex_exit(&dn->dn_mtx); 1335 ASSERT3U(zfs_refcount_count(&dn->dn_holds), ==, 0); 1336 1337 ASSERT(dn->dn_dbuf == NULL || 1338 dmu_buf_get_user(&dn->dn_dbuf->db) == NULL); 1339 zrl_add(&dnh->dnh_zrlock); 1340 dnode_destroy(dn); /* implicit zrl_remove() */ 1341 zrl_destroy(&dnh->dnh_zrlock); 1342 dnh->dnh_dnode = NULL; 1343 } 1344 1345 void 1346 dnode_special_open(objset_t *os, dnode_phys_t *dnp, uint64_t object, 1347 dnode_handle_t *dnh) 1348 { 1349 dnode_t *dn; 1350 1351 zrl_init(&dnh->dnh_zrlock); 1352 VERIFY3U(1, ==, zrl_tryenter(&dnh->dnh_zrlock)); 1353 1354 dn = dnode_create(os, dnp, NULL, object, dnh); 1355 DNODE_VERIFY(dn); 1356 1357 zrl_exit(&dnh->dnh_zrlock); 1358 } 1359 1360 static void 1361 dnode_buf_evict_async(void *dbu) 1362 { 1363 dnode_children_t *dnc = dbu; 1364 1365 DNODE_STAT_BUMP(dnode_buf_evict); 1366 1367 for (int i = 0; i < dnc->dnc_count; i++) { 1368 dnode_handle_t *dnh = &dnc->dnc_children[i]; 1369 dnode_t *dn; 1370 1371 /* 1372 * The dnode handle lock guards against the dnode moving to 1373 * another valid address, so there is no need here to guard 1374 * against changes to or from NULL. 1375 */ 1376 if (!DN_SLOT_IS_PTR(dnh->dnh_dnode)) { 1377 zrl_destroy(&dnh->dnh_zrlock); 1378 dnh->dnh_dnode = DN_SLOT_UNINIT; 1379 continue; 1380 } 1381 1382 zrl_add(&dnh->dnh_zrlock); 1383 dn = dnh->dnh_dnode; 1384 /* 1385 * If there are holds on this dnode, then there should 1386 * be holds on the dnode's containing dbuf as well; thus 1387 * it wouldn't be eligible for eviction and this function 1388 * would not have been called. 1389 */ 1390 ASSERT(zfs_refcount_is_zero(&dn->dn_holds)); 1391 ASSERT(zfs_refcount_is_zero(&dn->dn_tx_holds)); 1392 1393 dnode_destroy(dn); /* implicit zrl_remove() for first slot */ 1394 zrl_destroy(&dnh->dnh_zrlock); 1395 dnh->dnh_dnode = DN_SLOT_UNINIT; 1396 } 1397 kmem_free(dnc, sizeof (dnode_children_t) + 1398 dnc->dnc_count * sizeof (dnode_handle_t)); 1399 } 1400 1401 /* 1402 * When the DNODE_MUST_BE_FREE flag is set, the "slots" parameter is used 1403 * to ensure the hole at the specified object offset is large enough to 1404 * hold the dnode being created. The slots parameter is also used to ensure 1405 * a dnode does not span multiple dnode blocks. In both of these cases, if 1406 * a failure occurs, ENOSPC is returned. Keep in mind, these failure cases 1407 * are only possible when using DNODE_MUST_BE_FREE. 1408 * 1409 * If the DNODE_MUST_BE_ALLOCATED flag is set, "slots" must be 0. 1410 * dnode_hold_impl() will check if the requested dnode is already consumed 1411 * as an extra dnode slot by an large dnode, in which case it returns 1412 * ENOENT. 1413 * 1414 * If the DNODE_DRY_RUN flag is set, we don't actually hold the dnode, just 1415 * return whether the hold would succeed or not. tag and dnp should set to 1416 * NULL in this case. 1417 * 1418 * errors: 1419 * EINVAL - Invalid object number or flags. 1420 * ENOSPC - Hole too small to fulfill "slots" request (DNODE_MUST_BE_FREE) 1421 * EEXIST - Refers to an allocated dnode (DNODE_MUST_BE_FREE) 1422 * - Refers to a freeing dnode (DNODE_MUST_BE_FREE) 1423 * - Refers to an interior dnode slot (DNODE_MUST_BE_ALLOCATED) 1424 * ENOENT - The requested dnode is not allocated (DNODE_MUST_BE_ALLOCATED) 1425 * - The requested dnode is being freed (DNODE_MUST_BE_ALLOCATED) 1426 * EIO - I/O error when reading the meta dnode dbuf. 1427 * 1428 * succeeds even for free dnodes. 1429 */ 1430 int 1431 dnode_hold_impl(objset_t *os, uint64_t object, int flag, int slots, 1432 const void *tag, dnode_t **dnp) 1433 { 1434 int epb, idx, err; 1435 int drop_struct_lock = FALSE; 1436 int type; 1437 uint64_t blk; 1438 dnode_t *mdn, *dn; 1439 dmu_buf_impl_t *db; 1440 dnode_children_t *dnc; 1441 dnode_phys_t *dn_block; 1442 dnode_handle_t *dnh; 1443 1444 ASSERT(!(flag & DNODE_MUST_BE_ALLOCATED) || (slots == 0)); 1445 ASSERT(!(flag & DNODE_MUST_BE_FREE) || (slots > 0)); 1446 IMPLY(flag & DNODE_DRY_RUN, (tag == NULL) && (dnp == NULL)); 1447 1448 /* 1449 * If you are holding the spa config lock as writer, you shouldn't 1450 * be asking the DMU to do *anything* unless it's the root pool 1451 * which may require us to read from the root filesystem while 1452 * holding some (not all) of the locks as writer. 1453 */ 1454 ASSERT(spa_config_held(os->os_spa, SCL_ALL, RW_WRITER) == 0 || 1455 (spa_is_root(os->os_spa) && 1456 spa_config_held(os->os_spa, SCL_STATE, RW_WRITER))); 1457 1458 ASSERT((flag & DNODE_MUST_BE_ALLOCATED) || (flag & DNODE_MUST_BE_FREE)); 1459 1460 if (object == DMU_USERUSED_OBJECT || object == DMU_GROUPUSED_OBJECT || 1461 object == DMU_PROJECTUSED_OBJECT) { 1462 if (object == DMU_USERUSED_OBJECT) 1463 dn = DMU_USERUSED_DNODE(os); 1464 else if (object == DMU_GROUPUSED_OBJECT) 1465 dn = DMU_GROUPUSED_DNODE(os); 1466 else 1467 dn = DMU_PROJECTUSED_DNODE(os); 1468 if (dn == NULL) 1469 return (SET_ERROR(ENOENT)); 1470 type = dn->dn_type; 1471 if ((flag & DNODE_MUST_BE_ALLOCATED) && type == DMU_OT_NONE) 1472 return (SET_ERROR(ENOENT)); 1473 if ((flag & DNODE_MUST_BE_FREE) && type != DMU_OT_NONE) 1474 return (SET_ERROR(EEXIST)); 1475 DNODE_VERIFY(dn); 1476 /* Don't actually hold if dry run, just return 0 */ 1477 if (!(flag & DNODE_DRY_RUN)) { 1478 (void) zfs_refcount_add(&dn->dn_holds, tag); 1479 *dnp = dn; 1480 } 1481 return (0); 1482 } 1483 1484 if (object == 0 || object >= DN_MAX_OBJECT) 1485 return (SET_ERROR(EINVAL)); 1486 1487 mdn = DMU_META_DNODE(os); 1488 ASSERT(mdn->dn_object == DMU_META_DNODE_OBJECT); 1489 1490 DNODE_VERIFY(mdn); 1491 1492 if (!RW_WRITE_HELD(&mdn->dn_struct_rwlock)) { 1493 rw_enter(&mdn->dn_struct_rwlock, RW_READER); 1494 drop_struct_lock = TRUE; 1495 } 1496 1497 blk = dbuf_whichblock(mdn, 0, object * sizeof (dnode_phys_t)); 1498 db = dbuf_hold(mdn, blk, FTAG); 1499 if (drop_struct_lock) 1500 rw_exit(&mdn->dn_struct_rwlock); 1501 if (db == NULL) { 1502 DNODE_STAT_BUMP(dnode_hold_dbuf_hold); 1503 return (SET_ERROR(EIO)); 1504 } 1505 1506 /* 1507 * We do not need to decrypt to read the dnode so it doesn't matter 1508 * if we get the encrypted or decrypted version. 1509 */ 1510 err = dbuf_read(db, NULL, DB_RF_CANFAIL | 1511 DMU_READ_NO_PREFETCH | DMU_READ_NO_DECRYPT); 1512 if (err) { 1513 DNODE_STAT_BUMP(dnode_hold_dbuf_read); 1514 dbuf_rele(db, FTAG); 1515 return (err); 1516 } 1517 1518 ASSERT3U(db->db.db_size, >=, 1<<DNODE_SHIFT); 1519 epb = db->db.db_size >> DNODE_SHIFT; 1520 1521 idx = object & (epb - 1); 1522 dn_block = (dnode_phys_t *)db->db.db_data; 1523 1524 ASSERT(DB_DNODE(db)->dn_type == DMU_OT_DNODE); 1525 dnc = dmu_buf_get_user(&db->db); 1526 dnh = NULL; 1527 if (dnc == NULL) { 1528 dnode_children_t *winner; 1529 int skip = 0; 1530 1531 dnc = kmem_zalloc(sizeof (dnode_children_t) + 1532 epb * sizeof (dnode_handle_t), KM_SLEEP); 1533 dnc->dnc_count = epb; 1534 dnh = &dnc->dnc_children[0]; 1535 1536 /* Initialize dnode slot status from dnode_phys_t */ 1537 for (int i = 0; i < epb; i++) { 1538 zrl_init(&dnh[i].dnh_zrlock); 1539 1540 if (skip) { 1541 skip--; 1542 continue; 1543 } 1544 1545 if (dn_block[i].dn_type != DMU_OT_NONE) { 1546 int interior = dn_block[i].dn_extra_slots; 1547 1548 dnode_set_slots(dnc, i, 1, DN_SLOT_ALLOCATED); 1549 dnode_set_slots(dnc, i + 1, interior, 1550 DN_SLOT_INTERIOR); 1551 skip = interior; 1552 } else { 1553 dnh[i].dnh_dnode = DN_SLOT_FREE; 1554 skip = 0; 1555 } 1556 } 1557 1558 dmu_buf_init_user(&dnc->dnc_dbu, NULL, 1559 dnode_buf_evict_async, NULL); 1560 winner = dmu_buf_set_user(&db->db, &dnc->dnc_dbu); 1561 if (winner != NULL) { 1562 1563 for (int i = 0; i < epb; i++) 1564 zrl_destroy(&dnh[i].dnh_zrlock); 1565 1566 kmem_free(dnc, sizeof (dnode_children_t) + 1567 epb * sizeof (dnode_handle_t)); 1568 dnc = winner; 1569 } 1570 } 1571 1572 ASSERT(dnc->dnc_count == epb); 1573 1574 if (flag & DNODE_MUST_BE_ALLOCATED) { 1575 slots = 1; 1576 1577 dnode_slots_hold(dnc, idx, slots); 1578 dnh = &dnc->dnc_children[idx]; 1579 1580 if (DN_SLOT_IS_PTR(dnh->dnh_dnode)) { 1581 dn = dnh->dnh_dnode; 1582 } else if (dnh->dnh_dnode == DN_SLOT_INTERIOR) { 1583 DNODE_STAT_BUMP(dnode_hold_alloc_interior); 1584 dnode_slots_rele(dnc, idx, slots); 1585 dbuf_rele(db, FTAG); 1586 return (SET_ERROR(EEXIST)); 1587 } else if (dnh->dnh_dnode != DN_SLOT_ALLOCATED) { 1588 DNODE_STAT_BUMP(dnode_hold_alloc_misses); 1589 dnode_slots_rele(dnc, idx, slots); 1590 dbuf_rele(db, FTAG); 1591 return (SET_ERROR(ENOENT)); 1592 } else { 1593 dnode_slots_rele(dnc, idx, slots); 1594 while (!dnode_slots_tryenter(dnc, idx, slots)) { 1595 DNODE_STAT_BUMP(dnode_hold_alloc_lock_retry); 1596 kpreempt(KPREEMPT_SYNC); 1597 } 1598 1599 /* 1600 * Someone else won the race and called dnode_create() 1601 * after we checked DN_SLOT_IS_PTR() above but before 1602 * we acquired the lock. 1603 */ 1604 if (DN_SLOT_IS_PTR(dnh->dnh_dnode)) { 1605 DNODE_STAT_BUMP(dnode_hold_alloc_lock_misses); 1606 dn = dnh->dnh_dnode; 1607 } else { 1608 dn = dnode_create(os, dn_block + idx, db, 1609 object, dnh); 1610 dmu_buf_add_user_size(&db->db, 1611 sizeof (dnode_t)); 1612 } 1613 } 1614 1615 mutex_enter(&dn->dn_mtx); 1616 if (dn->dn_type == DMU_OT_NONE || dn->dn_free_txg != 0) { 1617 DNODE_STAT_BUMP(dnode_hold_alloc_type_none); 1618 mutex_exit(&dn->dn_mtx); 1619 dnode_slots_rele(dnc, idx, slots); 1620 dbuf_rele(db, FTAG); 1621 return (SET_ERROR(ENOENT)); 1622 } 1623 1624 /* Don't actually hold if dry run, just return 0 */ 1625 if (flag & DNODE_DRY_RUN) { 1626 mutex_exit(&dn->dn_mtx); 1627 dnode_slots_rele(dnc, idx, slots); 1628 dbuf_rele(db, FTAG); 1629 return (0); 1630 } 1631 1632 DNODE_STAT_BUMP(dnode_hold_alloc_hits); 1633 } else if (flag & DNODE_MUST_BE_FREE) { 1634 1635 if (idx + slots - 1 >= DNODES_PER_BLOCK) { 1636 DNODE_STAT_BUMP(dnode_hold_free_overflow); 1637 dbuf_rele(db, FTAG); 1638 return (SET_ERROR(ENOSPC)); 1639 } 1640 1641 dnode_slots_hold(dnc, idx, slots); 1642 1643 if (!dnode_check_slots_free(dnc, idx, slots)) { 1644 DNODE_STAT_BUMP(dnode_hold_free_misses); 1645 dnode_slots_rele(dnc, idx, slots); 1646 dbuf_rele(db, FTAG); 1647 return (SET_ERROR(ENOSPC)); 1648 } 1649 1650 dnode_slots_rele(dnc, idx, slots); 1651 while (!dnode_slots_tryenter(dnc, idx, slots)) { 1652 DNODE_STAT_BUMP(dnode_hold_free_lock_retry); 1653 kpreempt(KPREEMPT_SYNC); 1654 } 1655 1656 if (!dnode_check_slots_free(dnc, idx, slots)) { 1657 DNODE_STAT_BUMP(dnode_hold_free_lock_misses); 1658 dnode_slots_rele(dnc, idx, slots); 1659 dbuf_rele(db, FTAG); 1660 return (SET_ERROR(ENOSPC)); 1661 } 1662 1663 /* 1664 * Allocated but otherwise free dnodes which would 1665 * be in the interior of a multi-slot dnodes need 1666 * to be freed. Single slot dnodes can be safely 1667 * re-purposed as a performance optimization. 1668 */ 1669 if (slots > 1) { 1670 uint_t reclaimed = 1671 dnode_reclaim_slots(dnc, idx + 1, slots - 1); 1672 if (reclaimed > 0) 1673 dmu_buf_sub_user_size(&db->db, 1674 reclaimed * sizeof (dnode_t)); 1675 } 1676 1677 dnh = &dnc->dnc_children[idx]; 1678 if (DN_SLOT_IS_PTR(dnh->dnh_dnode)) { 1679 dn = dnh->dnh_dnode; 1680 } else { 1681 dn = dnode_create(os, dn_block + idx, db, 1682 object, dnh); 1683 dmu_buf_add_user_size(&db->db, sizeof (dnode_t)); 1684 } 1685 1686 mutex_enter(&dn->dn_mtx); 1687 if (!zfs_refcount_is_zero(&dn->dn_holds) || dn->dn_free_txg) { 1688 DNODE_STAT_BUMP(dnode_hold_free_refcount); 1689 mutex_exit(&dn->dn_mtx); 1690 dnode_slots_rele(dnc, idx, slots); 1691 dbuf_rele(db, FTAG); 1692 return (SET_ERROR(EEXIST)); 1693 } 1694 1695 /* Don't actually hold if dry run, just return 0 */ 1696 if (flag & DNODE_DRY_RUN) { 1697 mutex_exit(&dn->dn_mtx); 1698 dnode_slots_rele(dnc, idx, slots); 1699 dbuf_rele(db, FTAG); 1700 return (0); 1701 } 1702 1703 dnode_set_slots(dnc, idx + 1, slots - 1, DN_SLOT_INTERIOR); 1704 DNODE_STAT_BUMP(dnode_hold_free_hits); 1705 } else { 1706 dbuf_rele(db, FTAG); 1707 return (SET_ERROR(EINVAL)); 1708 } 1709 1710 ASSERT0(dn->dn_free_txg); 1711 1712 if (zfs_refcount_add(&dn->dn_holds, tag) == 1) 1713 dbuf_add_ref(db, dnh); 1714 1715 mutex_exit(&dn->dn_mtx); 1716 1717 /* Now we can rely on the hold to prevent the dnode from moving. */ 1718 dnode_slots_rele(dnc, idx, slots); 1719 1720 DNODE_VERIFY(dn); 1721 ASSERT3P(dnp, !=, NULL); 1722 ASSERT3P(dn->dn_dbuf, ==, db); 1723 ASSERT3U(dn->dn_object, ==, object); 1724 dbuf_rele(db, FTAG); 1725 1726 *dnp = dn; 1727 return (0); 1728 } 1729 1730 /* 1731 * Return held dnode if the object is allocated, NULL if not. 1732 */ 1733 int 1734 dnode_hold(objset_t *os, uint64_t object, const void *tag, dnode_t **dnp) 1735 { 1736 return (dnode_hold_impl(os, object, DNODE_MUST_BE_ALLOCATED, 0, tag, 1737 dnp)); 1738 } 1739 1740 /* 1741 * Can only add a reference if there is already at least one 1742 * reference on the dnode. Returns FALSE if unable to add a 1743 * new reference. 1744 */ 1745 static boolean_t 1746 dnode_add_ref_locked(dnode_t *dn, const void *tag) 1747 { 1748 ASSERT(MUTEX_HELD(&dn->dn_mtx)); 1749 if (zfs_refcount_is_zero(&dn->dn_holds)) 1750 return (FALSE); 1751 VERIFY(1 < zfs_refcount_add(&dn->dn_holds, tag)); 1752 return (TRUE); 1753 } 1754 1755 boolean_t 1756 dnode_add_ref(dnode_t *dn, const void *tag) 1757 { 1758 mutex_enter(&dn->dn_mtx); 1759 boolean_t r = dnode_add_ref_locked(dn, tag); 1760 mutex_exit(&dn->dn_mtx); 1761 return (r); 1762 } 1763 1764 void 1765 dnode_rele(dnode_t *dn, const void *tag) 1766 { 1767 mutex_enter(&dn->dn_mtx); 1768 dnode_rele_and_unlock(dn, tag, B_FALSE); 1769 } 1770 1771 void 1772 dnode_rele_and_unlock(dnode_t *dn, const void *tag, boolean_t evicting) 1773 { 1774 uint64_t refs; 1775 /* Get while the hold prevents the dnode from moving. */ 1776 dmu_buf_impl_t *db = dn->dn_dbuf; 1777 dnode_handle_t *dnh = dn->dn_handle; 1778 1779 refs = zfs_refcount_remove(&dn->dn_holds, tag); 1780 if (refs == 0) 1781 cv_broadcast(&dn->dn_nodnholds); 1782 1783 /* 1784 * It's unsafe to release the last hold on a dnode by dnode_rele() or 1785 * indirectly by dbuf_rele() while relying on the dnode handle to 1786 * prevent the dnode from moving, since releasing the last hold could 1787 * result in the dnode's parent dbuf evicting its dnode handles. For 1788 * that reason anyone calling dnode_rele() or dbuf_rele() without some 1789 * other direct or indirect hold on the dnode must first drop the dnode 1790 * handle. 1791 */ 1792 #ifdef ZFS_DEBUG 1793 ASSERT(refs > 0 || zrl_owner(&dnh->dnh_zrlock) != curthread); 1794 #endif 1795 1796 mutex_exit(&dn->dn_mtx); 1797 /* 1798 * After the dn_mtx is released the dn and dnh may be destroyed, 1799 * they are no longer safe to use after this point. 1800 */ 1801 1802 /* NOTE: the DNODE_DNODE does not have a dn_dbuf */ 1803 if (refs == 0 && db != NULL) { 1804 /* 1805 * Another thread could add a hold to the dnode handle in 1806 * dnode_hold_impl() while holding the parent dbuf. Since the 1807 * hold on the parent dbuf prevents the handle from being 1808 * destroyed, the hold on the handle is OK. We can't yet assert 1809 * that the handle has zero references, but that will be 1810 * asserted anyway when the handle gets destroyed. 1811 */ 1812 mutex_enter(&db->db_mtx); 1813 dbuf_rele_and_unlock(db, dnh, evicting); 1814 } 1815 } 1816 1817 /* 1818 * Test whether we can create a dnode at the specified location. 1819 */ 1820 int 1821 dnode_try_claim(objset_t *os, uint64_t object, int slots) 1822 { 1823 return (dnode_hold_impl(os, object, DNODE_MUST_BE_FREE | DNODE_DRY_RUN, 1824 slots, NULL, NULL)); 1825 } 1826 1827 /* 1828 * Test if the dnode is dirty, or carrying uncommitted records. 1829 * 1830 * dn_dirtycnt is the number of txgs this dnode is dirty on. It's incremented 1831 * in dnode_setdirty() the first time the dnode is dirtied on a txg, and 1832 * decremented in either dnode_rele_task() or userquota_updates_task() when the 1833 * txg is synced out. 1834 */ 1835 boolean_t 1836 dnode_is_dirty(dnode_t *dn) 1837 { 1838 mutex_enter(&dn->dn_mtx); 1839 boolean_t dirty = (dn->dn_dirtycnt != 0); 1840 mutex_exit(&dn->dn_mtx); 1841 return (dirty); 1842 } 1843 1844 void 1845 dnode_setdirty(dnode_t *dn, dmu_tx_t *tx) 1846 { 1847 objset_t *os = dn->dn_objset; 1848 uint64_t txg = tx->tx_txg; 1849 1850 if (DMU_OBJECT_IS_SPECIAL(dn->dn_object)) { 1851 dsl_dataset_dirty(os->os_dsl_dataset, tx); 1852 return; 1853 } 1854 1855 DNODE_VERIFY(dn); 1856 1857 #ifdef ZFS_DEBUG 1858 mutex_enter(&dn->dn_mtx); 1859 ASSERT(dn->dn_phys->dn_type || dn->dn_allocated_txg); 1860 ASSERT(dn->dn_free_txg == 0 || dn->dn_free_txg >= txg); 1861 mutex_exit(&dn->dn_mtx); 1862 #endif 1863 1864 /* 1865 * Determine old uid/gid when necessary 1866 */ 1867 dmu_objset_userquota_get_ids(dn, B_TRUE, tx); 1868 1869 multilist_t *dirtylist = &os->os_dirty_dnodes[txg & TXG_MASK]; 1870 multilist_sublist_t *mls = multilist_sublist_lock_obj(dirtylist, dn); 1871 1872 /* 1873 * If we are already marked dirty, we're done. 1874 */ 1875 if (multilist_link_active(&dn->dn_dirty_link[txg & TXG_MASK])) { 1876 multilist_sublist_unlock(mls); 1877 return; 1878 } 1879 1880 ASSERT(!zfs_refcount_is_zero(&dn->dn_holds) || 1881 !avl_is_empty(&dn->dn_dbufs)); 1882 ASSERT(dn->dn_datablksz != 0); 1883 ASSERT0(dn->dn_next_bonuslen[txg & TXG_MASK]); 1884 ASSERT0(dn->dn_next_blksz[txg & TXG_MASK]); 1885 ASSERT0(dn->dn_next_bonustype[txg & TXG_MASK]); 1886 1887 dprintf_ds(os->os_dsl_dataset, "obj=%llu txg=%llu\n", 1888 (u_longlong_t)dn->dn_object, (u_longlong_t)txg); 1889 1890 multilist_sublist_insert_head(mls, dn); 1891 1892 multilist_sublist_unlock(mls); 1893 1894 /* 1895 * The dnode maintains a hold on its containing dbuf as 1896 * long as there are holds on it. Each instantiated child 1897 * dbuf maintains a hold on the dnode. When the last child 1898 * drops its hold, the dnode will drop its hold on the 1899 * containing dbuf. We add a "dirty hold" here so that the 1900 * dnode will hang around after we finish processing its 1901 * children. 1902 */ 1903 mutex_enter(&dn->dn_mtx); 1904 VERIFY(dnode_add_ref_locked(dn, (void *)(uintptr_t)tx->tx_txg)); 1905 dn->dn_dirtycnt++; 1906 ASSERT3U(dn->dn_dirtycnt, <=, 3); 1907 mutex_exit(&dn->dn_mtx); 1908 1909 (void) dbuf_dirty(dn->dn_dbuf, tx); 1910 1911 dsl_dataset_dirty(os->os_dsl_dataset, tx); 1912 } 1913 1914 void 1915 dnode_free(dnode_t *dn, dmu_tx_t *tx) 1916 { 1917 mutex_enter(&dn->dn_mtx); 1918 if (dn->dn_type == DMU_OT_NONE || dn->dn_free_txg) { 1919 mutex_exit(&dn->dn_mtx); 1920 return; 1921 } 1922 dn->dn_free_txg = tx->tx_txg; 1923 mutex_exit(&dn->dn_mtx); 1924 1925 dnode_setdirty(dn, tx); 1926 } 1927 1928 /* 1929 * Try to change the block size for the indicated dnode. This can only 1930 * succeed if there are no blocks allocated or dirty beyond first block 1931 */ 1932 int 1933 dnode_set_blksz(dnode_t *dn, uint64_t size, int ibs, dmu_tx_t *tx) 1934 { 1935 dmu_buf_impl_t *db; 1936 int err; 1937 1938 ASSERT3U(size, <=, spa_maxblocksize(dmu_objset_spa(dn->dn_objset))); 1939 if (size == 0) 1940 size = SPA_MINBLOCKSIZE; 1941 else 1942 size = P2ROUNDUP(size, SPA_MINBLOCKSIZE); 1943 1944 if (ibs == dn->dn_indblkshift) 1945 ibs = 0; 1946 1947 if (size == dn->dn_datablksz && ibs == 0) 1948 return (0); 1949 1950 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 1951 1952 /* Check for any allocated blocks beyond the first */ 1953 if (dn->dn_maxblkid != 0) 1954 goto fail; 1955 1956 mutex_enter(&dn->dn_dbufs_mtx); 1957 for (db = avl_first(&dn->dn_dbufs); db != NULL; 1958 db = AVL_NEXT(&dn->dn_dbufs, db)) { 1959 if (db->db_blkid != 0 && db->db_blkid != DMU_BONUS_BLKID && 1960 db->db_blkid != DMU_SPILL_BLKID) { 1961 mutex_exit(&dn->dn_dbufs_mtx); 1962 goto fail; 1963 } 1964 } 1965 mutex_exit(&dn->dn_dbufs_mtx); 1966 1967 if (ibs && dn->dn_nlevels != 1) 1968 goto fail; 1969 1970 dnode_setdirty(dn, tx); 1971 if (size != dn->dn_datablksz) { 1972 /* resize the old block */ 1973 err = dbuf_hold_impl(dn, 0, 0, TRUE, FALSE, FTAG, &db); 1974 if (err == 0) { 1975 dbuf_new_size(db, size, tx); 1976 } else if (err != ENOENT) { 1977 goto fail; 1978 } 1979 1980 dnode_setdblksz(dn, size); 1981 dn->dn_next_blksz[tx->tx_txg & TXG_MASK] = size; 1982 if (db) 1983 dbuf_rele(db, FTAG); 1984 } 1985 if (ibs) { 1986 dn->dn_indblkshift = ibs; 1987 dn->dn_next_indblkshift[tx->tx_txg & TXG_MASK] = ibs; 1988 } 1989 1990 rw_exit(&dn->dn_struct_rwlock); 1991 return (0); 1992 1993 fail: 1994 rw_exit(&dn->dn_struct_rwlock); 1995 return (SET_ERROR(ENOTSUP)); 1996 } 1997 1998 static void 1999 dnode_set_nlevels_impl(dnode_t *dn, int new_nlevels, dmu_tx_t *tx) 2000 { 2001 uint64_t txgoff = tx->tx_txg & TXG_MASK; 2002 int old_nlevels = dn->dn_nlevels; 2003 dmu_buf_impl_t *db; 2004 list_t *list; 2005 dbuf_dirty_record_t *new, *dr, *dr_next; 2006 2007 ASSERT(RW_WRITE_HELD(&dn->dn_struct_rwlock)); 2008 2009 ASSERT3U(new_nlevels, >, dn->dn_nlevels); 2010 dn->dn_nlevels = new_nlevels; 2011 2012 ASSERT3U(new_nlevels, >, dn->dn_next_nlevels[txgoff]); 2013 dn->dn_next_nlevels[txgoff] = new_nlevels; 2014 2015 /* dirty the left indirects */ 2016 db = dbuf_hold_level(dn, old_nlevels, 0, FTAG); 2017 ASSERT(db != NULL); 2018 new = dbuf_dirty(db, tx); 2019 dbuf_rele(db, FTAG); 2020 2021 /* transfer the dirty records to the new indirect */ 2022 mutex_enter(&dn->dn_mtx); 2023 mutex_enter(&new->dt.di.dr_mtx); 2024 list = &dn->dn_dirty_records[txgoff]; 2025 for (dr = list_head(list); dr; dr = dr_next) { 2026 dr_next = list_next(&dn->dn_dirty_records[txgoff], dr); 2027 2028 IMPLY(dr->dr_dbuf == NULL, old_nlevels == 1); 2029 if (dr->dr_dbuf == NULL || 2030 (dr->dr_dbuf->db_level == old_nlevels - 1 && 2031 dr->dr_dbuf->db_blkid != DMU_BONUS_BLKID && 2032 dr->dr_dbuf->db_blkid != DMU_SPILL_BLKID)) { 2033 list_remove(&dn->dn_dirty_records[txgoff], dr); 2034 list_insert_tail(&new->dt.di.dr_children, dr); 2035 dr->dr_parent = new; 2036 } 2037 } 2038 mutex_exit(&new->dt.di.dr_mtx); 2039 mutex_exit(&dn->dn_mtx); 2040 } 2041 2042 int 2043 dnode_set_nlevels(dnode_t *dn, int nlevels, dmu_tx_t *tx) 2044 { 2045 int ret = 0; 2046 2047 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 2048 2049 if (dn->dn_nlevels == nlevels) { 2050 ret = 0; 2051 goto out; 2052 } else if (nlevels < dn->dn_nlevels) { 2053 ret = SET_ERROR(EINVAL); 2054 goto out; 2055 } 2056 2057 dnode_set_nlevels_impl(dn, nlevels, tx); 2058 2059 out: 2060 rw_exit(&dn->dn_struct_rwlock); 2061 return (ret); 2062 } 2063 2064 /* read-holding callers must not rely on the lock being continuously held */ 2065 void 2066 dnode_new_blkid(dnode_t *dn, uint64_t blkid, dmu_tx_t *tx, boolean_t have_read, 2067 boolean_t force) 2068 { 2069 int epbs, new_nlevels; 2070 uint64_t sz; 2071 2072 ASSERT(blkid != DMU_BONUS_BLKID); 2073 2074 ASSERT(have_read ? 2075 RW_READ_HELD(&dn->dn_struct_rwlock) : 2076 RW_WRITE_HELD(&dn->dn_struct_rwlock)); 2077 2078 /* 2079 * if we have a read-lock, check to see if we need to do any work 2080 * before upgrading to a write-lock. 2081 */ 2082 if (have_read) { 2083 if (blkid <= dn->dn_maxblkid) 2084 return; 2085 2086 if (!rw_tryupgrade(&dn->dn_struct_rwlock)) { 2087 rw_exit(&dn->dn_struct_rwlock); 2088 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 2089 } 2090 } 2091 2092 /* 2093 * Raw sends (indicated by the force flag) require that we take the 2094 * given blkid even if the value is lower than the current value. 2095 */ 2096 if (!force && blkid <= dn->dn_maxblkid) 2097 goto out; 2098 2099 /* 2100 * We use the (otherwise unused) top bit of dn_next_maxblkid[txgoff] 2101 * to indicate that this field is set. This allows us to set the 2102 * maxblkid to 0 on an existing object in dnode_sync(). 2103 */ 2104 dn->dn_maxblkid = blkid; 2105 dn->dn_next_maxblkid[tx->tx_txg & TXG_MASK] = 2106 blkid | DMU_NEXT_MAXBLKID_SET; 2107 2108 /* 2109 * Compute the number of levels necessary to support the new maxblkid. 2110 * Raw sends will ensure nlevels is set correctly for us. 2111 */ 2112 new_nlevels = 1; 2113 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT; 2114 for (sz = dn->dn_nblkptr; 2115 sz <= blkid && sz >= dn->dn_nblkptr; sz <<= epbs) 2116 new_nlevels++; 2117 2118 ASSERT3U(new_nlevels, <=, DN_MAX_LEVELS); 2119 2120 if (!force) { 2121 if (new_nlevels > dn->dn_nlevels) 2122 dnode_set_nlevels_impl(dn, new_nlevels, tx); 2123 } else { 2124 ASSERT3U(dn->dn_nlevels, >=, new_nlevels); 2125 } 2126 2127 out: 2128 if (have_read) 2129 rw_downgrade(&dn->dn_struct_rwlock); 2130 } 2131 2132 static void 2133 dnode_dirty_l1(dnode_t *dn, uint64_t l1blkid, dmu_tx_t *tx) 2134 { 2135 dmu_buf_impl_t *db = dbuf_hold_level(dn, 1, l1blkid, FTAG); 2136 if (db != NULL) { 2137 dmu_buf_will_dirty(&db->db, tx); 2138 dbuf_rele(db, FTAG); 2139 } 2140 } 2141 2142 /* 2143 * Dirty all the in-core level-1 dbufs in the range specified by start_blkid 2144 * and end_blkid. 2145 */ 2146 static void 2147 dnode_dirty_l1range(dnode_t *dn, uint64_t start_blkid, uint64_t end_blkid, 2148 dmu_tx_t *tx) 2149 { 2150 dmu_buf_impl_t *db_search; 2151 dmu_buf_impl_t *db; 2152 avl_index_t where; 2153 2154 db_search = kmem_zalloc(sizeof (dmu_buf_impl_t), KM_SLEEP); 2155 2156 mutex_enter(&dn->dn_dbufs_mtx); 2157 2158 db_search->db_level = 1; 2159 db_search->db_blkid = start_blkid + 1; 2160 db_search->db_state = DB_SEARCH; 2161 for (;;) { 2162 2163 db = avl_find(&dn->dn_dbufs, db_search, &where); 2164 if (db == NULL) 2165 db = avl_nearest(&dn->dn_dbufs, where, AVL_AFTER); 2166 2167 if (db == NULL || db->db_level != 1 || 2168 db->db_blkid >= end_blkid) { 2169 break; 2170 } 2171 2172 /* 2173 * Setup the next blkid we want to search for. 2174 */ 2175 db_search->db_blkid = db->db_blkid + 1; 2176 ASSERT3U(db->db_blkid, >=, start_blkid); 2177 2178 /* 2179 * If the dbuf transitions to DB_EVICTING while we're trying 2180 * to dirty it, then we will be unable to discover it in 2181 * the dbuf hash table. This will result in a call to 2182 * dbuf_create() which needs to acquire the dn_dbufs_mtx 2183 * lock. To avoid a deadlock, we drop the lock before 2184 * dirtying the level-1 dbuf. 2185 */ 2186 mutex_exit(&dn->dn_dbufs_mtx); 2187 dnode_dirty_l1(dn, db->db_blkid, tx); 2188 mutex_enter(&dn->dn_dbufs_mtx); 2189 } 2190 2191 #ifdef ZFS_DEBUG 2192 /* 2193 * Walk all the in-core level-1 dbufs and verify they have been dirtied. 2194 */ 2195 db_search->db_level = 1; 2196 db_search->db_blkid = start_blkid + 1; 2197 db_search->db_state = DB_SEARCH; 2198 db = avl_find(&dn->dn_dbufs, db_search, &where); 2199 if (db == NULL) 2200 db = avl_nearest(&dn->dn_dbufs, where, AVL_AFTER); 2201 for (; db != NULL; db = AVL_NEXT(&dn->dn_dbufs, db)) { 2202 if (db->db_level != 1 || db->db_blkid >= end_blkid) 2203 break; 2204 if (db->db_state != DB_EVICTING) 2205 ASSERT(db->db_dirtycnt > 0); 2206 } 2207 #endif 2208 kmem_free(db_search, sizeof (dmu_buf_impl_t)); 2209 mutex_exit(&dn->dn_dbufs_mtx); 2210 } 2211 2212 static void 2213 dnode_partial_zero(dnode_t *dn, uint64_t off, uint64_t blkoff, uint64_t len, 2214 dmu_tx_t *tx) 2215 { 2216 dmu_buf_impl_t *db; 2217 int res; 2218 2219 rw_enter(&dn->dn_struct_rwlock, RW_READER); 2220 res = dbuf_hold_impl(dn, 0, dbuf_whichblock(dn, 0, off), TRUE, FALSE, 2221 FTAG, &db); 2222 rw_exit(&dn->dn_struct_rwlock); 2223 if (res == 0) { 2224 db_lock_type_t dblt; 2225 boolean_t dirty; 2226 2227 dblt = dmu_buf_lock_parent(db, RW_READER, FTAG); 2228 /* don't dirty if not on disk and not dirty */ 2229 dirty = !list_is_empty(&db->db_dirty_records) || 2230 (db->db_blkptr && !BP_IS_HOLE(db->db_blkptr)); 2231 dmu_buf_unlock_parent(db, dblt, FTAG); 2232 if (dirty) { 2233 caddr_t data; 2234 2235 dmu_buf_will_dirty(&db->db, tx); 2236 data = db->db.db_data; 2237 memset(data + blkoff, 0, len); 2238 } 2239 dbuf_rele(db, FTAG); 2240 } 2241 } 2242 2243 void 2244 dnode_free_range(dnode_t *dn, uint64_t off, uint64_t len, dmu_tx_t *tx) 2245 { 2246 uint64_t blkoff, blkid, nblks; 2247 int blksz, blkshift, head, tail; 2248 int trunc = FALSE; 2249 int epbs; 2250 2251 blksz = dn->dn_datablksz; 2252 blkshift = dn->dn_datablkshift; 2253 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT; 2254 2255 if (len == DMU_OBJECT_END) { 2256 len = UINT64_MAX - off; 2257 trunc = TRUE; 2258 } 2259 2260 /* 2261 * First, block align the region to free: 2262 */ 2263 if (ISP2(blksz)) { 2264 head = P2NPHASE(off, blksz); 2265 blkoff = P2PHASE(off, blksz); 2266 if ((off >> blkshift) > dn->dn_maxblkid) 2267 return; 2268 } else { 2269 ASSERT0(dn->dn_maxblkid); 2270 if (off == 0 && len >= blksz) { 2271 /* 2272 * Freeing the whole block; fast-track this request. 2273 */ 2274 blkid = 0; 2275 nblks = 1; 2276 if (dn->dn_nlevels > 1) { 2277 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 2278 dnode_dirty_l1(dn, 0, tx); 2279 rw_exit(&dn->dn_struct_rwlock); 2280 } 2281 goto done; 2282 } else if (off >= blksz) { 2283 /* Freeing past end-of-data */ 2284 return; 2285 } else { 2286 /* Freeing part of the block. */ 2287 head = blksz - off; 2288 ASSERT3U(head, >, 0); 2289 } 2290 blkoff = off; 2291 } 2292 /* zero out any partial block data at the start of the range */ 2293 if (head) { 2294 ASSERT3U(blkoff + head, ==, blksz); 2295 if (len < head) 2296 head = len; 2297 dnode_partial_zero(dn, off, blkoff, head, tx); 2298 off += head; 2299 len -= head; 2300 } 2301 2302 /* If the range was less than one block, we're done */ 2303 if (len == 0) 2304 return; 2305 2306 /* If the remaining range is past end of file, we're done */ 2307 if ((off >> blkshift) > dn->dn_maxblkid) 2308 return; 2309 2310 ASSERT(ISP2(blksz)); 2311 if (trunc) 2312 tail = 0; 2313 else 2314 tail = P2PHASE(len, blksz); 2315 2316 ASSERT0(P2PHASE(off, blksz)); 2317 /* zero out any partial block data at the end of the range */ 2318 if (tail) { 2319 if (len < tail) 2320 tail = len; 2321 dnode_partial_zero(dn, off + len, 0, tail, tx); 2322 len -= tail; 2323 } 2324 2325 /* If the range did not include a full block, we are done */ 2326 if (len == 0) 2327 return; 2328 2329 ASSERT(IS_P2ALIGNED(off, blksz)); 2330 ASSERT(trunc || IS_P2ALIGNED(len, blksz)); 2331 blkid = off >> blkshift; 2332 nblks = len >> blkshift; 2333 if (trunc) 2334 nblks += 1; 2335 2336 /* 2337 * Dirty all the indirect blocks in this range. Note that only 2338 * the first and last indirect blocks can actually be written 2339 * (if they were partially freed) -- they must be dirtied, even if 2340 * they do not exist on disk yet. The interior blocks will 2341 * be freed by free_children(), so they will not actually be written. 2342 * Even though these interior blocks will not be written, we 2343 * dirty them for two reasons: 2344 * 2345 * - It ensures that the indirect blocks remain in memory until 2346 * syncing context. (They have already been prefetched by 2347 * dmu_tx_hold_free(), so we don't have to worry about reading 2348 * them serially here.) 2349 * 2350 * - The dirty space accounting will put pressure on the txg sync 2351 * mechanism to begin syncing, and to delay transactions if there 2352 * is a large amount of freeing. Even though these indirect 2353 * blocks will not be written, we could need to write the same 2354 * amount of space if we copy the freed BPs into deadlists. 2355 */ 2356 if (dn->dn_nlevels > 1) { 2357 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 2358 uint64_t first, last; 2359 2360 first = blkid >> epbs; 2361 dnode_dirty_l1(dn, first, tx); 2362 if (trunc) 2363 last = dn->dn_maxblkid >> epbs; 2364 else 2365 last = (blkid + nblks - 1) >> epbs; 2366 if (last != first) 2367 dnode_dirty_l1(dn, last, tx); 2368 2369 dnode_dirty_l1range(dn, first, last, tx); 2370 2371 int shift = dn->dn_datablkshift + dn->dn_indblkshift - 2372 SPA_BLKPTRSHIFT; 2373 for (uint64_t i = first + 1; i < last; i++) { 2374 /* 2375 * Set i to the blockid of the next non-hole 2376 * level-1 indirect block at or after i. Note 2377 * that dnode_next_offset() operates in terms of 2378 * level-0-equivalent bytes. 2379 */ 2380 uint64_t ibyte = i << shift; 2381 int err = dnode_next_offset(dn, DNODE_FIND_HAVELOCK, 2382 &ibyte, 2, 1, 0); 2383 i = ibyte >> shift; 2384 if (i >= last) 2385 break; 2386 2387 /* 2388 * Normally we should not see an error, either 2389 * from dnode_next_offset() or dbuf_hold_level() 2390 * (except for ESRCH from dnode_next_offset). 2391 * If there is an i/o error, then when we read 2392 * this block in syncing context, it will use 2393 * ZIO_FLAG_MUSTSUCCEED, and thus hang/panic according 2394 * to the "failmode" property. dnode_next_offset() 2395 * doesn't have a flag to indicate MUSTSUCCEED. 2396 */ 2397 if (err != 0) 2398 break; 2399 2400 dnode_dirty_l1(dn, i, tx); 2401 } 2402 rw_exit(&dn->dn_struct_rwlock); 2403 } 2404 2405 done: 2406 /* 2407 * Add this range to the dnode range list. 2408 * We will finish up this free operation in the syncing phase. 2409 */ 2410 mutex_enter(&dn->dn_mtx); 2411 { 2412 int txgoff = tx->tx_txg & TXG_MASK; 2413 2414 FREE_RANGE_VERIFY(tx, dn); 2415 if (dn->dn_free_ranges[txgoff] == NULL) { 2416 dn->dn_free_ranges[txgoff] = 2417 zfs_range_tree_create_flags( 2418 NULL, ZFS_RANGE_SEG64, NULL, 0, 0, 2419 ZFS_RT_F_DYN_NAME, rt_name(dn, "dn_free_ranges")); 2420 } 2421 zfs_range_tree_clear(dn->dn_free_ranges[txgoff], blkid, nblks); 2422 zfs_range_tree_add(dn->dn_free_ranges[txgoff], blkid, nblks); 2423 } 2424 dprintf_dnode(dn, "blkid=%llu nblks=%llu txg=%llu\n", 2425 (u_longlong_t)blkid, (u_longlong_t)nblks, 2426 (u_longlong_t)tx->tx_txg); 2427 mutex_exit(&dn->dn_mtx); 2428 2429 dbuf_free_range(dn, blkid, blkid + nblks - 1, tx); 2430 dnode_setdirty(dn, tx); 2431 } 2432 2433 static boolean_t 2434 dnode_spill_freed(dnode_t *dn) 2435 { 2436 int i; 2437 2438 mutex_enter(&dn->dn_mtx); 2439 for (i = 0; i < TXG_SIZE; i++) { 2440 if (dn->dn_rm_spillblk[i] == DN_KILL_SPILLBLK) 2441 break; 2442 } 2443 mutex_exit(&dn->dn_mtx); 2444 return (i < TXG_SIZE); 2445 } 2446 2447 /* return TRUE if this blkid was freed in a recent txg, or FALSE if it wasn't */ 2448 uint64_t 2449 dnode_block_freed(dnode_t *dn, uint64_t blkid) 2450 { 2451 int i; 2452 2453 if (blkid == DMU_BONUS_BLKID) 2454 return (FALSE); 2455 2456 if (dn->dn_free_txg) 2457 return (TRUE); 2458 2459 if (blkid == DMU_SPILL_BLKID) 2460 return (dnode_spill_freed(dn)); 2461 2462 mutex_enter(&dn->dn_mtx); 2463 for (i = 0; i < TXG_SIZE; i++) { 2464 if (dn->dn_free_ranges[i] != NULL && 2465 zfs_range_tree_contains(dn->dn_free_ranges[i], blkid, 1)) 2466 break; 2467 } 2468 mutex_exit(&dn->dn_mtx); 2469 return (i < TXG_SIZE); 2470 } 2471 2472 /* 2473 * Check if a level-0 block was freed in a TXG after override_txg. 2474 * 2475 * When a block has been overridden (e.g., by block clone or direct I/O), 2476 * we can't use dnode_block_freed() because it checks all active TXGs. 2477 * A free from a TXG *before* the override should not make the block appear 2478 * freed. 2479 */ 2480 uint64_t 2481 dnode_block_freed_after(dnode_t *dn, uint64_t blkid, uint64_t override_txg) 2482 { 2483 ASSERT(blkid != DMU_BONUS_BLKID); 2484 ASSERT(blkid != DMU_SPILL_BLKID); 2485 2486 if (dn->dn_free_txg) 2487 return (TRUE); 2488 2489 mutex_enter(&dn->dn_mtx); 2490 uint64_t open = spa_open_txg(dmu_objset_spa(dn->dn_objset)); 2491 for (uint64_t txg = override_txg + 1; txg <= open; txg++) { 2492 int i = txg & TXG_MASK; 2493 if (dn->dn_free_ranges[i] != NULL && 2494 zfs_range_tree_contains(dn->dn_free_ranges[i], blkid, 1)) { 2495 mutex_exit(&dn->dn_mtx); 2496 return (TRUE); 2497 } 2498 } 2499 mutex_exit(&dn->dn_mtx); 2500 return (FALSE); 2501 } 2502 2503 /* call from syncing context when we actually write/free space for this dnode */ 2504 void 2505 dnode_diduse_space(dnode_t *dn, int64_t delta) 2506 { 2507 uint64_t space; 2508 dprintf_dnode(dn, "dn=%p dnp=%p used=%llu delta=%lld\n", 2509 dn, dn->dn_phys, 2510 (u_longlong_t)dn->dn_phys->dn_used, 2511 (longlong_t)delta); 2512 2513 mutex_enter(&dn->dn_mtx); 2514 space = DN_USED_BYTES(dn->dn_phys); 2515 if (delta > 0) { 2516 ASSERT3U(space + delta, >=, space); /* no overflow */ 2517 } else { 2518 ASSERT3U(space, >=, -delta); /* no underflow */ 2519 } 2520 space += delta; 2521 if (spa_version(dn->dn_objset->os_spa) < SPA_VERSION_DNODE_BYTES) { 2522 ASSERT0((dn->dn_phys->dn_flags & DNODE_FLAG_USED_BYTES)); 2523 ASSERT0(P2PHASE(space, 1<<DEV_BSHIFT)); 2524 dn->dn_phys->dn_used = space >> DEV_BSHIFT; 2525 } else { 2526 dn->dn_phys->dn_used = space; 2527 dn->dn_phys->dn_flags |= DNODE_FLAG_USED_BYTES; 2528 } 2529 mutex_exit(&dn->dn_mtx); 2530 } 2531 2532 /* 2533 * Scans the block at the indicated "level" looking for a hole or data, 2534 * depending on 'flags' starting from array position given by *index. 2535 * 2536 * If lvl > 0, then we are scanning an indirect block looking at its 2537 * pointers. If lvl == 0, then we are looking at a block of dnodes. 2538 * 2539 * If we don't find what we are looking for in the block, we return ESRCH. 2540 * Otherwise, return with *index set to the matching array position. 2541 * 2542 * In both cases, *offset is updated to point at the matched BP/dnode or 2543 * the next offset to search (unless at the limit of possible offsets). 2544 * 2545 * The basic search algorithm used below by dnode_next_offset() uses this 2546 * function to perform a block-order tree traversal. We search up the block 2547 * tree (widen the search) until we find something (i.e., we don't return 2548 * ESRCH) and then search back down the tree (narrow the search) until we 2549 * reach our original search level or backtrack up because nothing matches. 2550 */ 2551 static int 2552 dnode_next_offset_level(dnode_t *dn, int flags, int lvl, uint64_t blkid, 2553 int *index, uint64_t blkfill, uint64_t txg, uint64_t *offset) 2554 { 2555 dmu_buf_impl_t *db = NULL; 2556 void *data = NULL; 2557 uint64_t epbs = dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT; 2558 uint64_t epb = 1ULL << epbs; 2559 uint64_t minfill, maxfill; 2560 boolean_t hole; 2561 int i, inc, error, span; 2562 2563 ASSERT(RW_LOCK_HELD(&dn->dn_struct_rwlock)); 2564 2565 hole = ((flags & DNODE_FIND_HOLE) != 0); 2566 inc = (flags & DNODE_FIND_BACKWARDS) ? -1 : 1; 2567 ASSERT(txg == 0 || !hole); 2568 2569 if (lvl == dn->dn_phys->dn_nlevels) { 2570 error = 0; 2571 epb = dn->dn_phys->dn_nblkptr; 2572 data = dn->dn_phys->dn_blkptr; 2573 if (dn->dn_dbuf != NULL) 2574 rw_enter(&dn->dn_dbuf->db_rwlock, RW_READER); 2575 else if (dmu_objset_ds(dn->dn_objset) != NULL) 2576 rrw_enter(&dmu_objset_ds(dn->dn_objset)->ds_bp_rwlock, 2577 RW_READER, FTAG); 2578 } else { 2579 error = dbuf_hold_impl(dn, lvl, blkid, TRUE, FALSE, FTAG, &db); 2580 if (error) { 2581 if (error != ENOENT) 2582 return (error); 2583 if (hole) 2584 return (0); 2585 return (SET_ERROR(ESRCH)); 2586 } 2587 error = dbuf_read(db, NULL, 2588 DB_RF_CANFAIL | DB_RF_HAVESTRUCT | 2589 DMU_READ_NO_PREFETCH | DMU_READ_NO_DECRYPT); 2590 if (error) { 2591 dbuf_rele(db, FTAG); 2592 return (error); 2593 } 2594 data = db->db.db_data; 2595 rw_enter(&db->db_rwlock, RW_READER); 2596 } 2597 2598 if (db != NULL && txg != 0 && (db->db_blkptr == NULL || 2599 BP_GET_LOGICAL_BIRTH(db->db_blkptr) <= txg || 2600 BP_IS_HOLE(db->db_blkptr))) { 2601 /* 2602 * This can only happen when we are searching up the tree 2603 * and these conditions mean that we need to keep climbing. 2604 */ 2605 error = SET_ERROR(ESRCH); 2606 } else if (lvl == 0) { 2607 dnode_phys_t *dnp = data; 2608 2609 ASSERT(dn->dn_type == DMU_OT_DNODE); 2610 ASSERT(!(flags & DNODE_FIND_BACKWARDS)); 2611 2612 for (i = *index; i < blkfill; i += dnp[i].dn_extra_slots + 1) { 2613 if ((dnp[i].dn_type == DMU_OT_NONE) == hole) 2614 break; 2615 } 2616 2617 if (i == blkfill) 2618 error = SET_ERROR(ESRCH); 2619 2620 *index = i; 2621 *offset = (*offset & ~(DNODE_BLOCK_SIZE - 1)) + 2622 (i << DNODE_SHIFT); 2623 } else { 2624 blkptr_t *bp = data; 2625 span = (lvl - 1) * epbs + dn->dn_datablkshift; 2626 minfill = 0; 2627 maxfill = blkfill << ((lvl - 1) * epbs); 2628 2629 if (hole) 2630 maxfill--; 2631 else 2632 minfill++; 2633 2634 for (i = *index; i >= 0 && i < epb; i += inc) { 2635 if (BP_GET_FILL(&bp[i]) >= minfill && 2636 BP_GET_FILL(&bp[i]) <= maxfill && 2637 (hole || BP_GET_LOGICAL_BIRTH(&bp[i]) > txg)) 2638 break; 2639 } 2640 2641 if (i < 0 || i >= epb) 2642 error = SET_ERROR(ESRCH); 2643 2644 *index = i; 2645 if (span < 8 * sizeof (*offset)) { 2646 uint64_t nblk = blkid << epbs; 2647 if (i >= 0 || blkid != 0) 2648 nblk += i; 2649 if ((nblk >> (8 * sizeof (*offset) - span)) == 0) 2650 *offset = (flags & DNODE_FIND_BACKWARDS) ? 2651 /* backwards: position offset at the end */ 2652 MIN(*offset, ((nblk + 1) << span) - 1) : 2653 MAX(*offset, nblk << span); 2654 } 2655 } 2656 2657 if (db != NULL) { 2658 rw_exit(&db->db_rwlock); 2659 dbuf_rele(db, FTAG); 2660 } else { 2661 if (dn->dn_dbuf != NULL) 2662 rw_exit(&dn->dn_dbuf->db_rwlock); 2663 else if (dmu_objset_ds(dn->dn_objset) != NULL) 2664 rrw_exit(&dmu_objset_ds(dn->dn_objset)->ds_bp_rwlock, 2665 FTAG); 2666 } 2667 2668 return (error); 2669 } 2670 2671 /* 2672 * Find the next hole, data, or sparse region at or after *offset. 2673 * The value 'blkfill' tells us how many items we expect to find 2674 * in an L0 data block; this value is 1 for normal objects, 2675 * DNODES_PER_BLOCK for the meta dnode, and some fraction of 2676 * DNODES_PER_BLOCK when searching for sparse regions thereof. 2677 * 2678 * If minlvl == 0, this searches for dnodes or unallocated dnodes. 2679 * If found, *offset points to the first offset of the matched dnode. 2680 * Backwards search is not allowed for dnodes. 2681 * 2682 * If minlvl > 0, this searches for blocks at the given level. 2683 * If found, *offset points to the first L0 offset of the block 2684 * (or for backwards search, the last offset, inclusive). 2685 * 2686 * If not found, in both cases, *offset is set to the first (or last) 2687 * offset of the unallocated indirect block where the search ended or 2688 * the initial offset if no such block was encountered. 2689 * 2690 * Examples: 2691 * 2692 * dnode_next_offset(dn, flags, offset, 1, 1, 0); 2693 * Finds the next/previous hole/data in a file. 2694 * Used in dmu_offset_next(). 2695 * 2696 * dnode_next_offset(mdn, flags, offset, 0, DNODES_PER_BLOCK, txg); 2697 * Finds the next free/allocated dnode an objset's meta-dnode. 2698 * Only finds objects that have new contents since txg (ie. 2699 * bonus buffer changes and content removal are ignored). 2700 * Used in dmu_object_next(). 2701 * 2702 * dnode_next_offset(mdn, DNODE_FIND_HOLE, offset, 2, DNODES_PER_BLOCK >> 2, 0); 2703 * Finds the next L2 meta-dnode bp that's at most 1/4 full. 2704 * Used in dmu_object_alloc(). 2705 */ 2706 int 2707 dnode_next_offset(dnode_t *dn, int flags, uint64_t *offset, 2708 int minlvl, uint64_t blkfill, uint64_t txg) 2709 { 2710 uint64_t blkid; 2711 int index, epbs; 2712 int lvl, maxlvl; 2713 int error = 0; 2714 2715 if (!(flags & DNODE_FIND_HAVELOCK)) 2716 rw_enter(&dn->dn_struct_rwlock, RW_READER); 2717 2718 if (dn->dn_phys->dn_nlevels == 0) { 2719 error = SET_ERROR(ESRCH); 2720 goto out; 2721 } 2722 2723 if (dn->dn_datablkshift == 0) { 2724 if (*offset < dn->dn_datablksz) { 2725 if (flags & DNODE_FIND_HOLE) 2726 *offset = dn->dn_datablksz; 2727 } else { 2728 error = SET_ERROR(ESRCH); 2729 } 2730 goto out; 2731 } 2732 2733 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT; 2734 maxlvl = dn->dn_phys->dn_nlevels; 2735 2736 if (minlvl > 0) { 2737 uint64_t n = dbuf_whichblock(dn, minlvl - 1, *offset); 2738 blkid = n >> epbs; 2739 index = BF64_GET(n, 0, epbs); 2740 } else { 2741 blkid = dbuf_whichblock(dn, 0, *offset); 2742 index = (*offset >> DNODE_SHIFT) & (blkfill - 1); 2743 ASSERT3U(BF64_GET(*offset, 0, DNODE_SHIFT), ==, 0); 2744 } 2745 2746 for (lvl = minlvl; lvl <= maxlvl; ) { 2747 error = dnode_next_offset_level(dn, 2748 flags, lvl, blkid, &index, blkfill, txg, offset); 2749 2750 if (error == 0 && lvl > minlvl) { 2751 /* Continue search at matched block in lvl-1. */ 2752 blkid = (blkid << epbs) + index; 2753 index = 0; 2754 --lvl; 2755 } else if (error == ESRCH && lvl < maxlvl) { 2756 /* 2757 * Continue search at next/prev index in lvl+1 block. 2758 * 2759 * Usually we only search upwards at the start of the 2760 * search as higher level blocks point at a matching 2761 * minlvl block in most cases, but we backtrack if not. 2762 * 2763 * This can happen for txg > 0 searches if the block 2764 * contains only BPs/dnodes freed at that txg. It also 2765 * happens if we are still syncing out the tree, and 2766 * some BP's at higher levels are not updated yet. 2767 * 2768 * We must adjust index to avoid coming back to the 2769 * same offset and getting stuck looping forever. The 2770 * next loop goes up again if index is -1 or (1<<epbs). 2771 */ 2772 index = BF64_GET(blkid, 0, epbs) + 2773 ((flags & DNODE_FIND_BACKWARDS) ? -1 : 1); 2774 blkid = blkid >> epbs; 2775 ++lvl; 2776 } else { 2777 break; 2778 } 2779 } 2780 2781 /* 2782 * There's always a "virtual hole" at the end of the object, even 2783 * if all BP's which physically exist are non-holes. 2784 */ 2785 if ((flags & DNODE_FIND_HOLE) && error == ESRCH && txg == 0 && 2786 minlvl == 1 && blkfill == 1 && !(flags & DNODE_FIND_BACKWARDS)) { 2787 error = 0; 2788 } 2789 2790 out: 2791 if (!(flags & DNODE_FIND_HAVELOCK)) 2792 rw_exit(&dn->dn_struct_rwlock); 2793 2794 return (error); 2795 } 2796 2797 EXPORT_SYMBOL(dnode_hold); 2798 EXPORT_SYMBOL(dnode_rele); 2799 EXPORT_SYMBOL(dnode_set_nlevels); 2800 EXPORT_SYMBOL(dnode_set_blksz); 2801 EXPORT_SYMBOL(dnode_free_range); 2802 EXPORT_SYMBOL(dnode_evict_dbufs); 2803 EXPORT_SYMBOL(dnode_evict_bonus); 2804 2805 ZFS_MODULE_PARAM(zfs, zfs_, default_bs, INT, ZMOD_RW, 2806 "Default dnode block shift"); 2807 ZFS_MODULE_PARAM(zfs, zfs_, default_ibs, INT, ZMOD_RW, 2808 "Default dnode indirect block shift"); 2809