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 https://opensource.org/licenses/CDDL-1.0. 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) 2011, 2020 by Delphix. All rights reserved. 24 * Copyright (c) 2013 by Saso Kiselkov. All rights reserved. 25 * Copyright (c) 2013, Joyent, Inc. All rights reserved. 26 * Copyright (c) 2016, Nexenta Systems, Inc. All rights reserved. 27 * Copyright (c) 2015 by Chunwei Chen. All rights reserved. 28 * Copyright (c) 2019 Datto Inc. 29 * Copyright (c) 2019, Klara Inc. 30 * Copyright (c) 2019, Allan Jude 31 * Copyright (c) 2022 Hewlett Packard Enterprise Development LP. 32 * Copyright (c) 2021, 2022 by Pawel Jakub Dawidek 33 */ 34 35 #include <sys/dmu.h> 36 #include <sys/dmu_impl.h> 37 #include <sys/dmu_tx.h> 38 #include <sys/dbuf.h> 39 #include <sys/dnode.h> 40 #include <sys/zfs_context.h> 41 #include <sys/dmu_objset.h> 42 #include <sys/dmu_traverse.h> 43 #include <sys/dsl_dataset.h> 44 #include <sys/dsl_dir.h> 45 #include <sys/dsl_pool.h> 46 #include <sys/dsl_synctask.h> 47 #include <sys/dsl_prop.h> 48 #include <sys/dmu_zfetch.h> 49 #include <sys/zfs_ioctl.h> 50 #include <sys/zap.h> 51 #include <sys/zio_checksum.h> 52 #include <sys/zio_compress.h> 53 #include <sys/sa.h> 54 #include <sys/zfeature.h> 55 #include <sys/abd.h> 56 #include <sys/brt.h> 57 #include <sys/trace_zfs.h> 58 #include <sys/zfs_racct.h> 59 #include <sys/zfs_rlock.h> 60 #ifdef _KERNEL 61 #include <sys/vmsystm.h> 62 #include <sys/zfs_znode.h> 63 #endif 64 65 /* 66 * Enable/disable nopwrite feature. 67 */ 68 static int zfs_nopwrite_enabled = 1; 69 70 /* 71 * Tunable to control percentage of dirtied L1 blocks from frees allowed into 72 * one TXG. After this threshold is crossed, additional dirty blocks from frees 73 * will wait until the next TXG. 74 * A value of zero will disable this throttle. 75 */ 76 static uint_t zfs_per_txg_dirty_frees_percent = 30; 77 78 /* 79 * Enable/disable forcing txg sync when dirty checking for holes with lseek(). 80 * By default this is enabled to ensure accurate hole reporting, it can result 81 * in a significant performance penalty for lseek(SEEK_HOLE) heavy workloads. 82 * Disabling this option will result in holes never being reported in dirty 83 * files which is always safe. 84 */ 85 static int zfs_dmu_offset_next_sync = 1; 86 87 /* 88 * Limit the amount we can prefetch with one call to this amount. This 89 * helps to limit the amount of memory that can be used by prefetching. 90 * Larger objects should be prefetched a bit at a time. 91 */ 92 #ifdef _ILP32 93 uint_t dmu_prefetch_max = 8 * 1024 * 1024; 94 #else 95 uint_t dmu_prefetch_max = 8 * SPA_MAXBLOCKSIZE; 96 #endif 97 98 const dmu_object_type_info_t dmu_ot[DMU_OT_NUMTYPES] = { 99 {DMU_BSWAP_UINT8, TRUE, FALSE, FALSE, "unallocated" }, 100 {DMU_BSWAP_ZAP, TRUE, TRUE, FALSE, "object directory" }, 101 {DMU_BSWAP_UINT64, TRUE, TRUE, FALSE, "object array" }, 102 {DMU_BSWAP_UINT8, TRUE, FALSE, FALSE, "packed nvlist" }, 103 {DMU_BSWAP_UINT64, TRUE, FALSE, FALSE, "packed nvlist size" }, 104 {DMU_BSWAP_UINT64, TRUE, FALSE, FALSE, "bpobj" }, 105 {DMU_BSWAP_UINT64, TRUE, FALSE, FALSE, "bpobj header" }, 106 {DMU_BSWAP_UINT64, TRUE, FALSE, FALSE, "SPA space map header" }, 107 {DMU_BSWAP_UINT64, TRUE, FALSE, FALSE, "SPA space map" }, 108 {DMU_BSWAP_UINT64, TRUE, FALSE, TRUE, "ZIL intent log" }, 109 {DMU_BSWAP_DNODE, TRUE, FALSE, TRUE, "DMU dnode" }, 110 {DMU_BSWAP_OBJSET, TRUE, TRUE, FALSE, "DMU objset" }, 111 {DMU_BSWAP_UINT64, TRUE, TRUE, FALSE, "DSL directory" }, 112 {DMU_BSWAP_ZAP, TRUE, TRUE, FALSE, "DSL directory child map"}, 113 {DMU_BSWAP_ZAP, TRUE, TRUE, FALSE, "DSL dataset snap map" }, 114 {DMU_BSWAP_ZAP, TRUE, TRUE, FALSE, "DSL props" }, 115 {DMU_BSWAP_UINT64, TRUE, TRUE, FALSE, "DSL dataset" }, 116 {DMU_BSWAP_ZNODE, TRUE, FALSE, FALSE, "ZFS znode" }, 117 {DMU_BSWAP_OLDACL, TRUE, FALSE, TRUE, "ZFS V0 ACL" }, 118 {DMU_BSWAP_UINT8, FALSE, FALSE, TRUE, "ZFS plain file" }, 119 {DMU_BSWAP_ZAP, TRUE, FALSE, TRUE, "ZFS directory" }, 120 {DMU_BSWAP_ZAP, TRUE, FALSE, FALSE, "ZFS master node" }, 121 {DMU_BSWAP_ZAP, TRUE, FALSE, TRUE, "ZFS delete queue" }, 122 {DMU_BSWAP_UINT8, FALSE, FALSE, TRUE, "zvol object" }, 123 {DMU_BSWAP_ZAP, TRUE, FALSE, FALSE, "zvol prop" }, 124 {DMU_BSWAP_UINT8, FALSE, FALSE, TRUE, "other uint8[]" }, 125 {DMU_BSWAP_UINT64, FALSE, FALSE, TRUE, "other uint64[]" }, 126 {DMU_BSWAP_ZAP, TRUE, FALSE, FALSE, "other ZAP" }, 127 {DMU_BSWAP_ZAP, TRUE, FALSE, FALSE, "persistent error log" }, 128 {DMU_BSWAP_UINT8, TRUE, FALSE, FALSE, "SPA history" }, 129 {DMU_BSWAP_UINT64, TRUE, FALSE, FALSE, "SPA history offsets" }, 130 {DMU_BSWAP_ZAP, TRUE, TRUE, FALSE, "Pool properties" }, 131 {DMU_BSWAP_ZAP, TRUE, TRUE, FALSE, "DSL permissions" }, 132 {DMU_BSWAP_ACL, TRUE, FALSE, TRUE, "ZFS ACL" }, 133 {DMU_BSWAP_UINT8, TRUE, FALSE, TRUE, "ZFS SYSACL" }, 134 {DMU_BSWAP_UINT8, TRUE, FALSE, TRUE, "FUID table" }, 135 {DMU_BSWAP_UINT64, TRUE, FALSE, FALSE, "FUID table size" }, 136 {DMU_BSWAP_ZAP, TRUE, TRUE, FALSE, "DSL dataset next clones"}, 137 {DMU_BSWAP_ZAP, TRUE, FALSE, FALSE, "scan work queue" }, 138 {DMU_BSWAP_ZAP, TRUE, FALSE, TRUE, "ZFS user/group/project used" }, 139 {DMU_BSWAP_ZAP, TRUE, FALSE, TRUE, "ZFS user/group/project quota"}, 140 {DMU_BSWAP_ZAP, TRUE, TRUE, FALSE, "snapshot refcount tags"}, 141 {DMU_BSWAP_ZAP, TRUE, FALSE, FALSE, "DDT ZAP algorithm" }, 142 {DMU_BSWAP_ZAP, TRUE, FALSE, FALSE, "DDT statistics" }, 143 {DMU_BSWAP_UINT8, TRUE, FALSE, TRUE, "System attributes" }, 144 {DMU_BSWAP_ZAP, TRUE, FALSE, TRUE, "SA master node" }, 145 {DMU_BSWAP_ZAP, TRUE, FALSE, TRUE, "SA attr registration" }, 146 {DMU_BSWAP_ZAP, TRUE, FALSE, TRUE, "SA attr layouts" }, 147 {DMU_BSWAP_ZAP, TRUE, FALSE, FALSE, "scan translations" }, 148 {DMU_BSWAP_UINT8, FALSE, FALSE, TRUE, "deduplicated block" }, 149 {DMU_BSWAP_ZAP, TRUE, TRUE, FALSE, "DSL deadlist map" }, 150 {DMU_BSWAP_UINT64, TRUE, TRUE, FALSE, "DSL deadlist map hdr" }, 151 {DMU_BSWAP_ZAP, TRUE, TRUE, FALSE, "DSL dir clones" }, 152 {DMU_BSWAP_UINT64, TRUE, FALSE, FALSE, "bpobj subobj" } 153 }; 154 155 dmu_object_byteswap_info_t dmu_ot_byteswap[DMU_BSWAP_NUMFUNCS] = { 156 { byteswap_uint8_array, "uint8" }, 157 { byteswap_uint16_array, "uint16" }, 158 { byteswap_uint32_array, "uint32" }, 159 { byteswap_uint64_array, "uint64" }, 160 { zap_byteswap, "zap" }, 161 { dnode_buf_byteswap, "dnode" }, 162 { dmu_objset_byteswap, "objset" }, 163 { zfs_znode_byteswap, "znode" }, 164 { zfs_oldacl_byteswap, "oldacl" }, 165 { zfs_acl_byteswap, "acl" } 166 }; 167 168 int 169 dmu_buf_hold_noread_by_dnode(dnode_t *dn, uint64_t offset, 170 const void *tag, dmu_buf_t **dbp) 171 { 172 uint64_t blkid; 173 dmu_buf_impl_t *db; 174 175 rw_enter(&dn->dn_struct_rwlock, RW_READER); 176 blkid = dbuf_whichblock(dn, 0, offset); 177 db = dbuf_hold(dn, blkid, tag); 178 rw_exit(&dn->dn_struct_rwlock); 179 180 if (db == NULL) { 181 *dbp = NULL; 182 return (SET_ERROR(EIO)); 183 } 184 185 *dbp = &db->db; 186 return (0); 187 } 188 189 int 190 dmu_buf_hold_noread(objset_t *os, uint64_t object, uint64_t offset, 191 const void *tag, dmu_buf_t **dbp) 192 { 193 dnode_t *dn; 194 uint64_t blkid; 195 dmu_buf_impl_t *db; 196 int err; 197 198 err = dnode_hold(os, object, FTAG, &dn); 199 if (err) 200 return (err); 201 rw_enter(&dn->dn_struct_rwlock, RW_READER); 202 blkid = dbuf_whichblock(dn, 0, offset); 203 db = dbuf_hold(dn, blkid, tag); 204 rw_exit(&dn->dn_struct_rwlock); 205 dnode_rele(dn, FTAG); 206 207 if (db == NULL) { 208 *dbp = NULL; 209 return (SET_ERROR(EIO)); 210 } 211 212 *dbp = &db->db; 213 return (err); 214 } 215 216 int 217 dmu_buf_hold_by_dnode(dnode_t *dn, uint64_t offset, 218 const void *tag, dmu_buf_t **dbp, int flags) 219 { 220 int err; 221 int db_flags = DB_RF_CANFAIL; 222 223 if (flags & DMU_READ_NO_PREFETCH) 224 db_flags |= DB_RF_NOPREFETCH; 225 if (flags & DMU_READ_NO_DECRYPT) 226 db_flags |= DB_RF_NO_DECRYPT; 227 228 err = dmu_buf_hold_noread_by_dnode(dn, offset, tag, dbp); 229 if (err == 0) { 230 dmu_buf_impl_t *db = (dmu_buf_impl_t *)(*dbp); 231 err = dbuf_read(db, NULL, db_flags); 232 if (err != 0) { 233 dbuf_rele(db, tag); 234 *dbp = NULL; 235 } 236 } 237 238 return (err); 239 } 240 241 int 242 dmu_buf_hold(objset_t *os, uint64_t object, uint64_t offset, 243 const void *tag, dmu_buf_t **dbp, int flags) 244 { 245 int err; 246 int db_flags = DB_RF_CANFAIL; 247 248 if (flags & DMU_READ_NO_PREFETCH) 249 db_flags |= DB_RF_NOPREFETCH; 250 if (flags & DMU_READ_NO_DECRYPT) 251 db_flags |= DB_RF_NO_DECRYPT; 252 253 err = dmu_buf_hold_noread(os, object, offset, tag, dbp); 254 if (err == 0) { 255 dmu_buf_impl_t *db = (dmu_buf_impl_t *)(*dbp); 256 err = dbuf_read(db, NULL, db_flags); 257 if (err != 0) { 258 dbuf_rele(db, tag); 259 *dbp = NULL; 260 } 261 } 262 263 return (err); 264 } 265 266 int 267 dmu_bonus_max(void) 268 { 269 return (DN_OLD_MAX_BONUSLEN); 270 } 271 272 int 273 dmu_set_bonus(dmu_buf_t *db_fake, int newsize, dmu_tx_t *tx) 274 { 275 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake; 276 dnode_t *dn; 277 int error; 278 279 DB_DNODE_ENTER(db); 280 dn = DB_DNODE(db); 281 282 if (dn->dn_bonus != db) { 283 error = SET_ERROR(EINVAL); 284 } else if (newsize < 0 || newsize > db_fake->db_size) { 285 error = SET_ERROR(EINVAL); 286 } else { 287 dnode_setbonuslen(dn, newsize, tx); 288 error = 0; 289 } 290 291 DB_DNODE_EXIT(db); 292 return (error); 293 } 294 295 int 296 dmu_set_bonustype(dmu_buf_t *db_fake, dmu_object_type_t type, dmu_tx_t *tx) 297 { 298 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake; 299 dnode_t *dn; 300 int error; 301 302 DB_DNODE_ENTER(db); 303 dn = DB_DNODE(db); 304 305 if (!DMU_OT_IS_VALID(type)) { 306 error = SET_ERROR(EINVAL); 307 } else if (dn->dn_bonus != db) { 308 error = SET_ERROR(EINVAL); 309 } else { 310 dnode_setbonus_type(dn, type, tx); 311 error = 0; 312 } 313 314 DB_DNODE_EXIT(db); 315 return (error); 316 } 317 318 dmu_object_type_t 319 dmu_get_bonustype(dmu_buf_t *db_fake) 320 { 321 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake; 322 dnode_t *dn; 323 dmu_object_type_t type; 324 325 DB_DNODE_ENTER(db); 326 dn = DB_DNODE(db); 327 type = dn->dn_bonustype; 328 DB_DNODE_EXIT(db); 329 330 return (type); 331 } 332 333 int 334 dmu_rm_spill(objset_t *os, uint64_t object, dmu_tx_t *tx) 335 { 336 dnode_t *dn; 337 int error; 338 339 error = dnode_hold(os, object, FTAG, &dn); 340 dbuf_rm_spill(dn, tx); 341 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 342 dnode_rm_spill(dn, tx); 343 rw_exit(&dn->dn_struct_rwlock); 344 dnode_rele(dn, FTAG); 345 return (error); 346 } 347 348 /* 349 * Lookup and hold the bonus buffer for the provided dnode. If the dnode 350 * has not yet been allocated a new bonus dbuf a will be allocated. 351 * Returns ENOENT, EIO, or 0. 352 */ 353 int dmu_bonus_hold_by_dnode(dnode_t *dn, const void *tag, dmu_buf_t **dbp, 354 uint32_t flags) 355 { 356 dmu_buf_impl_t *db; 357 int error; 358 uint32_t db_flags = DB_RF_MUST_SUCCEED; 359 360 if (flags & DMU_READ_NO_PREFETCH) 361 db_flags |= DB_RF_NOPREFETCH; 362 if (flags & DMU_READ_NO_DECRYPT) 363 db_flags |= DB_RF_NO_DECRYPT; 364 365 rw_enter(&dn->dn_struct_rwlock, RW_READER); 366 if (dn->dn_bonus == NULL) { 367 if (!rw_tryupgrade(&dn->dn_struct_rwlock)) { 368 rw_exit(&dn->dn_struct_rwlock); 369 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 370 } 371 if (dn->dn_bonus == NULL) 372 dbuf_create_bonus(dn); 373 } 374 db = dn->dn_bonus; 375 376 /* as long as the bonus buf is held, the dnode will be held */ 377 if (zfs_refcount_add(&db->db_holds, tag) == 1) { 378 VERIFY(dnode_add_ref(dn, db)); 379 atomic_inc_32(&dn->dn_dbufs_count); 380 } 381 382 /* 383 * Wait to drop dn_struct_rwlock until after adding the bonus dbuf's 384 * hold and incrementing the dbuf count to ensure that dnode_move() sees 385 * a dnode hold for every dbuf. 386 */ 387 rw_exit(&dn->dn_struct_rwlock); 388 389 error = dbuf_read(db, NULL, db_flags); 390 if (error) { 391 dnode_evict_bonus(dn); 392 dbuf_rele(db, tag); 393 *dbp = NULL; 394 return (error); 395 } 396 397 *dbp = &db->db; 398 return (0); 399 } 400 401 int 402 dmu_bonus_hold(objset_t *os, uint64_t object, const void *tag, dmu_buf_t **dbp) 403 { 404 dnode_t *dn; 405 int error; 406 407 error = dnode_hold(os, object, FTAG, &dn); 408 if (error) 409 return (error); 410 411 error = dmu_bonus_hold_by_dnode(dn, tag, dbp, DMU_READ_NO_PREFETCH); 412 dnode_rele(dn, FTAG); 413 414 return (error); 415 } 416 417 /* 418 * returns ENOENT, EIO, or 0. 419 * 420 * This interface will allocate a blank spill dbuf when a spill blk 421 * doesn't already exist on the dnode. 422 * 423 * if you only want to find an already existing spill db, then 424 * dmu_spill_hold_existing() should be used. 425 */ 426 int 427 dmu_spill_hold_by_dnode(dnode_t *dn, uint32_t flags, const void *tag, 428 dmu_buf_t **dbp) 429 { 430 dmu_buf_impl_t *db = NULL; 431 int err; 432 433 if ((flags & DB_RF_HAVESTRUCT) == 0) 434 rw_enter(&dn->dn_struct_rwlock, RW_READER); 435 436 db = dbuf_hold(dn, DMU_SPILL_BLKID, tag); 437 438 if ((flags & DB_RF_HAVESTRUCT) == 0) 439 rw_exit(&dn->dn_struct_rwlock); 440 441 if (db == NULL) { 442 *dbp = NULL; 443 return (SET_ERROR(EIO)); 444 } 445 err = dbuf_read(db, NULL, flags); 446 if (err == 0) 447 *dbp = &db->db; 448 else { 449 dbuf_rele(db, tag); 450 *dbp = NULL; 451 } 452 return (err); 453 } 454 455 int 456 dmu_spill_hold_existing(dmu_buf_t *bonus, const void *tag, dmu_buf_t **dbp) 457 { 458 dmu_buf_impl_t *db = (dmu_buf_impl_t *)bonus; 459 dnode_t *dn; 460 int err; 461 462 DB_DNODE_ENTER(db); 463 dn = DB_DNODE(db); 464 465 if (spa_version(dn->dn_objset->os_spa) < SPA_VERSION_SA) { 466 err = SET_ERROR(EINVAL); 467 } else { 468 rw_enter(&dn->dn_struct_rwlock, RW_READER); 469 470 if (!dn->dn_have_spill) { 471 err = SET_ERROR(ENOENT); 472 } else { 473 err = dmu_spill_hold_by_dnode(dn, 474 DB_RF_HAVESTRUCT | DB_RF_CANFAIL, tag, dbp); 475 } 476 477 rw_exit(&dn->dn_struct_rwlock); 478 } 479 480 DB_DNODE_EXIT(db); 481 return (err); 482 } 483 484 int 485 dmu_spill_hold_by_bonus(dmu_buf_t *bonus, uint32_t flags, const void *tag, 486 dmu_buf_t **dbp) 487 { 488 dmu_buf_impl_t *db = (dmu_buf_impl_t *)bonus; 489 dnode_t *dn; 490 int err; 491 uint32_t db_flags = DB_RF_CANFAIL; 492 493 if (flags & DMU_READ_NO_DECRYPT) 494 db_flags |= DB_RF_NO_DECRYPT; 495 496 DB_DNODE_ENTER(db); 497 dn = DB_DNODE(db); 498 err = dmu_spill_hold_by_dnode(dn, db_flags, tag, dbp); 499 DB_DNODE_EXIT(db); 500 501 return (err); 502 } 503 504 /* 505 * Note: longer-term, we should modify all of the dmu_buf_*() interfaces 506 * to take a held dnode rather than <os, object> -- the lookup is wasteful, 507 * and can induce severe lock contention when writing to several files 508 * whose dnodes are in the same block. 509 */ 510 int 511 dmu_buf_hold_array_by_dnode(dnode_t *dn, uint64_t offset, uint64_t length, 512 boolean_t read, const void *tag, int *numbufsp, dmu_buf_t ***dbpp, 513 uint32_t flags) 514 { 515 dmu_buf_t **dbp; 516 zstream_t *zs = NULL; 517 uint64_t blkid, nblks, i; 518 uint32_t dbuf_flags; 519 int err; 520 zio_t *zio = NULL; 521 boolean_t missed = B_FALSE; 522 523 ASSERT(!read || length <= DMU_MAX_ACCESS); 524 525 /* 526 * Note: We directly notify the prefetch code of this read, so that 527 * we can tell it about the multi-block read. dbuf_read() only knows 528 * about the one block it is accessing. 529 */ 530 dbuf_flags = DB_RF_CANFAIL | DB_RF_NEVERWAIT | DB_RF_HAVESTRUCT | 531 DB_RF_NOPREFETCH; 532 533 if ((flags & DMU_READ_NO_DECRYPT) != 0) 534 dbuf_flags |= DB_RF_NO_DECRYPT; 535 536 rw_enter(&dn->dn_struct_rwlock, RW_READER); 537 if (dn->dn_datablkshift) { 538 int blkshift = dn->dn_datablkshift; 539 nblks = (P2ROUNDUP(offset + length, 1ULL << blkshift) - 540 P2ALIGN(offset, 1ULL << blkshift)) >> blkshift; 541 } else { 542 if (offset + length > dn->dn_datablksz) { 543 zfs_panic_recover("zfs: accessing past end of object " 544 "%llx/%llx (size=%u access=%llu+%llu)", 545 (longlong_t)dn->dn_objset-> 546 os_dsl_dataset->ds_object, 547 (longlong_t)dn->dn_object, dn->dn_datablksz, 548 (longlong_t)offset, (longlong_t)length); 549 rw_exit(&dn->dn_struct_rwlock); 550 return (SET_ERROR(EIO)); 551 } 552 nblks = 1; 553 } 554 dbp = kmem_zalloc(sizeof (dmu_buf_t *) * nblks, KM_SLEEP); 555 556 if (read) 557 zio = zio_root(dn->dn_objset->os_spa, NULL, NULL, 558 ZIO_FLAG_CANFAIL); 559 blkid = dbuf_whichblock(dn, 0, offset); 560 if ((flags & DMU_READ_NO_PREFETCH) == 0) { 561 /* 562 * Prepare the zfetch before initiating the demand reads, so 563 * that if multiple threads block on same indirect block, we 564 * base predictions on the original less racy request order. 565 */ 566 zs = dmu_zfetch_prepare(&dn->dn_zfetch, blkid, nblks, read, 567 B_TRUE); 568 } 569 for (i = 0; i < nblks; i++) { 570 dmu_buf_impl_t *db = dbuf_hold(dn, blkid + i, tag); 571 if (db == NULL) { 572 if (zs) 573 dmu_zfetch_run(zs, missed, B_TRUE); 574 rw_exit(&dn->dn_struct_rwlock); 575 dmu_buf_rele_array(dbp, nblks, tag); 576 if (read) 577 zio_nowait(zio); 578 return (SET_ERROR(EIO)); 579 } 580 581 /* 582 * Initiate async demand data read. 583 * We check the db_state after calling dbuf_read() because 584 * (1) dbuf_read() may change the state to CACHED due to a 585 * hit in the ARC, and (2) on a cache miss, a child will 586 * have been added to "zio" but not yet completed, so the 587 * state will not yet be CACHED. 588 */ 589 if (read) { 590 if (i == nblks - 1 && blkid + i < dn->dn_maxblkid && 591 offset + length < db->db.db_offset + 592 db->db.db_size) { 593 if (offset <= db->db.db_offset) 594 dbuf_flags |= DB_RF_PARTIAL_FIRST; 595 else 596 dbuf_flags |= DB_RF_PARTIAL_MORE; 597 } 598 (void) dbuf_read(db, zio, dbuf_flags); 599 if (db->db_state != DB_CACHED) 600 missed = B_TRUE; 601 } 602 dbp[i] = &db->db; 603 } 604 605 if (!read) 606 zfs_racct_write(length, nblks); 607 608 if (zs) 609 dmu_zfetch_run(zs, missed, B_TRUE); 610 rw_exit(&dn->dn_struct_rwlock); 611 612 if (read) { 613 /* wait for async read i/o */ 614 err = zio_wait(zio); 615 if (err) { 616 dmu_buf_rele_array(dbp, nblks, tag); 617 return (err); 618 } 619 620 /* wait for other io to complete */ 621 for (i = 0; i < nblks; i++) { 622 dmu_buf_impl_t *db = (dmu_buf_impl_t *)dbp[i]; 623 mutex_enter(&db->db_mtx); 624 while (db->db_state == DB_READ || 625 db->db_state == DB_FILL) 626 cv_wait(&db->db_changed, &db->db_mtx); 627 if (db->db_state == DB_UNCACHED) 628 err = SET_ERROR(EIO); 629 mutex_exit(&db->db_mtx); 630 if (err) { 631 dmu_buf_rele_array(dbp, nblks, tag); 632 return (err); 633 } 634 } 635 } 636 637 *numbufsp = nblks; 638 *dbpp = dbp; 639 return (0); 640 } 641 642 int 643 dmu_buf_hold_array(objset_t *os, uint64_t object, uint64_t offset, 644 uint64_t length, int read, const void *tag, int *numbufsp, 645 dmu_buf_t ***dbpp) 646 { 647 dnode_t *dn; 648 int err; 649 650 err = dnode_hold(os, object, FTAG, &dn); 651 if (err) 652 return (err); 653 654 err = dmu_buf_hold_array_by_dnode(dn, offset, length, read, tag, 655 numbufsp, dbpp, DMU_READ_PREFETCH); 656 657 dnode_rele(dn, FTAG); 658 659 return (err); 660 } 661 662 int 663 dmu_buf_hold_array_by_bonus(dmu_buf_t *db_fake, uint64_t offset, 664 uint64_t length, boolean_t read, const void *tag, int *numbufsp, 665 dmu_buf_t ***dbpp) 666 { 667 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake; 668 dnode_t *dn; 669 int err; 670 671 DB_DNODE_ENTER(db); 672 dn = DB_DNODE(db); 673 err = dmu_buf_hold_array_by_dnode(dn, offset, length, read, tag, 674 numbufsp, dbpp, DMU_READ_PREFETCH); 675 DB_DNODE_EXIT(db); 676 677 return (err); 678 } 679 680 void 681 dmu_buf_rele_array(dmu_buf_t **dbp_fake, int numbufs, const void *tag) 682 { 683 int i; 684 dmu_buf_impl_t **dbp = (dmu_buf_impl_t **)dbp_fake; 685 686 if (numbufs == 0) 687 return; 688 689 for (i = 0; i < numbufs; i++) { 690 if (dbp[i]) 691 dbuf_rele(dbp[i], tag); 692 } 693 694 kmem_free(dbp, sizeof (dmu_buf_t *) * numbufs); 695 } 696 697 /* 698 * Issue prefetch I/Os for the given blocks. If level is greater than 0, the 699 * indirect blocks prefetched will be those that point to the blocks containing 700 * the data starting at offset, and continuing to offset + len. If the range 701 * it too long, prefetch the first dmu_prefetch_max bytes as requested, while 702 * for the rest only a higher level, also fitting within dmu_prefetch_max. It 703 * should primarily help random reads, since for long sequential reads there is 704 * a speculative prefetcher. 705 * 706 * Note that if the indirect blocks above the blocks being prefetched are not 707 * in cache, they will be asynchronously read in. Dnode read by dnode_hold() 708 * is currently synchronous. 709 */ 710 void 711 dmu_prefetch(objset_t *os, uint64_t object, int64_t level, uint64_t offset, 712 uint64_t len, zio_priority_t pri) 713 { 714 dnode_t *dn; 715 int64_t level2 = level; 716 uint64_t start, end, start2, end2; 717 718 if (dmu_prefetch_max == 0 || len == 0) { 719 dmu_prefetch_dnode(os, object, pri); 720 return; 721 } 722 723 if (dnode_hold(os, object, FTAG, &dn) != 0) 724 return; 725 726 /* 727 * Depending on len we may do two prefetches: blocks [start, end) at 728 * level, and following blocks [start2, end2) at higher level2. 729 */ 730 rw_enter(&dn->dn_struct_rwlock, RW_READER); 731 if (dn->dn_datablkshift != 0) { 732 /* 733 * The object has multiple blocks. Calculate the full range 734 * of blocks [start, end2) and then split it into two parts, 735 * so that the first [start, end) fits into dmu_prefetch_max. 736 */ 737 start = dbuf_whichblock(dn, level, offset); 738 end2 = dbuf_whichblock(dn, level, offset + len - 1) + 1; 739 uint8_t ibs = dn->dn_indblkshift; 740 uint8_t bs = (level == 0) ? dn->dn_datablkshift : ibs; 741 uint_t limit = P2ROUNDUP(dmu_prefetch_max, 1 << bs) >> bs; 742 start2 = end = MIN(end2, start + limit); 743 744 /* 745 * Find level2 where [start2, end2) fits into dmu_prefetch_max. 746 */ 747 uint8_t ibps = ibs - SPA_BLKPTRSHIFT; 748 limit = P2ROUNDUP(dmu_prefetch_max, 1 << ibs) >> ibs; 749 do { 750 level2++; 751 start2 = P2ROUNDUP(start2, 1 << ibps) >> ibps; 752 end2 = P2ROUNDUP(end2, 1 << ibps) >> ibps; 753 } while (end2 - start2 > limit); 754 } else { 755 /* There is only one block. Prefetch it or nothing. */ 756 start = start2 = end2 = 0; 757 end = start + (level == 0 && offset < dn->dn_datablksz); 758 } 759 760 for (uint64_t i = start; i < end; i++) 761 dbuf_prefetch(dn, level, i, pri, 0); 762 for (uint64_t i = start2; i < end2; i++) 763 dbuf_prefetch(dn, level2, i, pri, 0); 764 rw_exit(&dn->dn_struct_rwlock); 765 766 dnode_rele(dn, FTAG); 767 } 768 769 /* 770 * Issue prefetch I/Os for the given object's dnode. 771 */ 772 void 773 dmu_prefetch_dnode(objset_t *os, uint64_t object, zio_priority_t pri) 774 { 775 if (object == 0 || object >= DN_MAX_OBJECT) 776 return; 777 778 dnode_t *dn = DMU_META_DNODE(os); 779 rw_enter(&dn->dn_struct_rwlock, RW_READER); 780 uint64_t blkid = dbuf_whichblock(dn, 0, object * sizeof (dnode_phys_t)); 781 dbuf_prefetch(dn, 0, blkid, pri, 0); 782 rw_exit(&dn->dn_struct_rwlock); 783 } 784 785 /* 786 * Get the next "chunk" of file data to free. We traverse the file from 787 * the end so that the file gets shorter over time (if we crashes in the 788 * middle, this will leave us in a better state). We find allocated file 789 * data by simply searching the allocated level 1 indirects. 790 * 791 * On input, *start should be the first offset that does not need to be 792 * freed (e.g. "offset + length"). On return, *start will be the first 793 * offset that should be freed and l1blks is set to the number of level 1 794 * indirect blocks found within the chunk. 795 */ 796 static int 797 get_next_chunk(dnode_t *dn, uint64_t *start, uint64_t minimum, uint64_t *l1blks) 798 { 799 uint64_t blks; 800 uint64_t maxblks = DMU_MAX_ACCESS >> (dn->dn_indblkshift + 1); 801 /* bytes of data covered by a level-1 indirect block */ 802 uint64_t iblkrange = (uint64_t)dn->dn_datablksz * 803 EPB(dn->dn_indblkshift, SPA_BLKPTRSHIFT); 804 805 ASSERT3U(minimum, <=, *start); 806 807 /* 808 * Check if we can free the entire range assuming that all of the 809 * L1 blocks in this range have data. If we can, we use this 810 * worst case value as an estimate so we can avoid having to look 811 * at the object's actual data. 812 */ 813 uint64_t total_l1blks = 814 (roundup(*start, iblkrange) - (minimum / iblkrange * iblkrange)) / 815 iblkrange; 816 if (total_l1blks <= maxblks) { 817 *l1blks = total_l1blks; 818 *start = minimum; 819 return (0); 820 } 821 ASSERT(ISP2(iblkrange)); 822 823 for (blks = 0; *start > minimum && blks < maxblks; blks++) { 824 int err; 825 826 /* 827 * dnode_next_offset(BACKWARDS) will find an allocated L1 828 * indirect block at or before the input offset. We must 829 * decrement *start so that it is at the end of the region 830 * to search. 831 */ 832 (*start)--; 833 834 err = dnode_next_offset(dn, 835 DNODE_FIND_BACKWARDS, start, 2, 1, 0); 836 837 /* if there are no indirect blocks before start, we are done */ 838 if (err == ESRCH) { 839 *start = minimum; 840 break; 841 } else if (err != 0) { 842 *l1blks = blks; 843 return (err); 844 } 845 846 /* set start to the beginning of this L1 indirect */ 847 *start = P2ALIGN(*start, iblkrange); 848 } 849 if (*start < minimum) 850 *start = minimum; 851 *l1blks = blks; 852 853 return (0); 854 } 855 856 /* 857 * If this objset is of type OST_ZFS return true if vfs's unmounted flag is set, 858 * otherwise return false. 859 * Used below in dmu_free_long_range_impl() to enable abort when unmounting 860 */ 861 static boolean_t 862 dmu_objset_zfs_unmounting(objset_t *os) 863 { 864 #ifdef _KERNEL 865 if (dmu_objset_type(os) == DMU_OST_ZFS) 866 return (zfs_get_vfs_flag_unmounted(os)); 867 #else 868 (void) os; 869 #endif 870 return (B_FALSE); 871 } 872 873 static int 874 dmu_free_long_range_impl(objset_t *os, dnode_t *dn, uint64_t offset, 875 uint64_t length) 876 { 877 uint64_t object_size; 878 int err; 879 uint64_t dirty_frees_threshold; 880 dsl_pool_t *dp = dmu_objset_pool(os); 881 882 if (dn == NULL) 883 return (SET_ERROR(EINVAL)); 884 885 object_size = (dn->dn_maxblkid + 1) * dn->dn_datablksz; 886 if (offset >= object_size) 887 return (0); 888 889 if (zfs_per_txg_dirty_frees_percent <= 100) 890 dirty_frees_threshold = 891 zfs_per_txg_dirty_frees_percent * zfs_dirty_data_max / 100; 892 else 893 dirty_frees_threshold = zfs_dirty_data_max / 20; 894 895 if (length == DMU_OBJECT_END || offset + length > object_size) 896 length = object_size - offset; 897 898 while (length != 0) { 899 uint64_t chunk_end, chunk_begin, chunk_len; 900 uint64_t l1blks; 901 dmu_tx_t *tx; 902 903 if (dmu_objset_zfs_unmounting(dn->dn_objset)) 904 return (SET_ERROR(EINTR)); 905 906 chunk_end = chunk_begin = offset + length; 907 908 /* move chunk_begin backwards to the beginning of this chunk */ 909 err = get_next_chunk(dn, &chunk_begin, offset, &l1blks); 910 if (err) 911 return (err); 912 ASSERT3U(chunk_begin, >=, offset); 913 ASSERT3U(chunk_begin, <=, chunk_end); 914 915 chunk_len = chunk_end - chunk_begin; 916 917 tx = dmu_tx_create(os); 918 dmu_tx_hold_free(tx, dn->dn_object, chunk_begin, chunk_len); 919 920 /* 921 * Mark this transaction as typically resulting in a net 922 * reduction in space used. 923 */ 924 dmu_tx_mark_netfree(tx); 925 err = dmu_tx_assign(tx, TXG_WAIT); 926 if (err) { 927 dmu_tx_abort(tx); 928 return (err); 929 } 930 931 uint64_t txg = dmu_tx_get_txg(tx); 932 933 mutex_enter(&dp->dp_lock); 934 uint64_t long_free_dirty = 935 dp->dp_long_free_dirty_pertxg[txg & TXG_MASK]; 936 mutex_exit(&dp->dp_lock); 937 938 /* 939 * To avoid filling up a TXG with just frees, wait for 940 * the next TXG to open before freeing more chunks if 941 * we have reached the threshold of frees. 942 */ 943 if (dirty_frees_threshold != 0 && 944 long_free_dirty >= dirty_frees_threshold) { 945 DMU_TX_STAT_BUMP(dmu_tx_dirty_frees_delay); 946 dmu_tx_commit(tx); 947 txg_wait_open(dp, 0, B_TRUE); 948 continue; 949 } 950 951 /* 952 * In order to prevent unnecessary write throttling, for each 953 * TXG, we track the cumulative size of L1 blocks being dirtied 954 * in dnode_free_range() below. We compare this number to a 955 * tunable threshold, past which we prevent new L1 dirty freeing 956 * blocks from being added into the open TXG. See 957 * dmu_free_long_range_impl() for details. The threshold 958 * prevents write throttle activation due to dirty freeing L1 959 * blocks taking up a large percentage of zfs_dirty_data_max. 960 */ 961 mutex_enter(&dp->dp_lock); 962 dp->dp_long_free_dirty_pertxg[txg & TXG_MASK] += 963 l1blks << dn->dn_indblkshift; 964 mutex_exit(&dp->dp_lock); 965 DTRACE_PROBE3(free__long__range, 966 uint64_t, long_free_dirty, uint64_t, chunk_len, 967 uint64_t, txg); 968 dnode_free_range(dn, chunk_begin, chunk_len, tx); 969 970 dmu_tx_commit(tx); 971 972 length -= chunk_len; 973 } 974 return (0); 975 } 976 977 int 978 dmu_free_long_range(objset_t *os, uint64_t object, 979 uint64_t offset, uint64_t length) 980 { 981 dnode_t *dn; 982 int err; 983 984 err = dnode_hold(os, object, FTAG, &dn); 985 if (err != 0) 986 return (err); 987 err = dmu_free_long_range_impl(os, dn, offset, length); 988 989 /* 990 * It is important to zero out the maxblkid when freeing the entire 991 * file, so that (a) subsequent calls to dmu_free_long_range_impl() 992 * will take the fast path, and (b) dnode_reallocate() can verify 993 * that the entire file has been freed. 994 */ 995 if (err == 0 && offset == 0 && length == DMU_OBJECT_END) 996 dn->dn_maxblkid = 0; 997 998 dnode_rele(dn, FTAG); 999 return (err); 1000 } 1001 1002 int 1003 dmu_free_long_object(objset_t *os, uint64_t object) 1004 { 1005 dmu_tx_t *tx; 1006 int err; 1007 1008 err = dmu_free_long_range(os, object, 0, DMU_OBJECT_END); 1009 if (err != 0) 1010 return (err); 1011 1012 tx = dmu_tx_create(os); 1013 dmu_tx_hold_bonus(tx, object); 1014 dmu_tx_hold_free(tx, object, 0, DMU_OBJECT_END); 1015 dmu_tx_mark_netfree(tx); 1016 err = dmu_tx_assign(tx, TXG_WAIT); 1017 if (err == 0) { 1018 err = dmu_object_free(os, object, tx); 1019 dmu_tx_commit(tx); 1020 } else { 1021 dmu_tx_abort(tx); 1022 } 1023 1024 return (err); 1025 } 1026 1027 int 1028 dmu_free_range(objset_t *os, uint64_t object, uint64_t offset, 1029 uint64_t size, dmu_tx_t *tx) 1030 { 1031 dnode_t *dn; 1032 int err = dnode_hold(os, object, FTAG, &dn); 1033 if (err) 1034 return (err); 1035 ASSERT(offset < UINT64_MAX); 1036 ASSERT(size == DMU_OBJECT_END || size <= UINT64_MAX - offset); 1037 dnode_free_range(dn, offset, size, tx); 1038 dnode_rele(dn, FTAG); 1039 return (0); 1040 } 1041 1042 static int 1043 dmu_read_impl(dnode_t *dn, uint64_t offset, uint64_t size, 1044 void *buf, uint32_t flags) 1045 { 1046 dmu_buf_t **dbp; 1047 int numbufs, err = 0; 1048 1049 /* 1050 * Deal with odd block sizes, where there can't be data past the first 1051 * block. If we ever do the tail block optimization, we will need to 1052 * handle that here as well. 1053 */ 1054 if (dn->dn_maxblkid == 0) { 1055 uint64_t newsz = offset > dn->dn_datablksz ? 0 : 1056 MIN(size, dn->dn_datablksz - offset); 1057 memset((char *)buf + newsz, 0, size - newsz); 1058 size = newsz; 1059 } 1060 1061 while (size > 0) { 1062 uint64_t mylen = MIN(size, DMU_MAX_ACCESS / 2); 1063 int i; 1064 1065 /* 1066 * NB: we could do this block-at-a-time, but it's nice 1067 * to be reading in parallel. 1068 */ 1069 err = dmu_buf_hold_array_by_dnode(dn, offset, mylen, 1070 TRUE, FTAG, &numbufs, &dbp, flags); 1071 if (err) 1072 break; 1073 1074 for (i = 0; i < numbufs; i++) { 1075 uint64_t tocpy; 1076 int64_t bufoff; 1077 dmu_buf_t *db = dbp[i]; 1078 1079 ASSERT(size > 0); 1080 1081 bufoff = offset - db->db_offset; 1082 tocpy = MIN(db->db_size - bufoff, size); 1083 1084 (void) memcpy(buf, (char *)db->db_data + bufoff, tocpy); 1085 1086 offset += tocpy; 1087 size -= tocpy; 1088 buf = (char *)buf + tocpy; 1089 } 1090 dmu_buf_rele_array(dbp, numbufs, FTAG); 1091 } 1092 return (err); 1093 } 1094 1095 int 1096 dmu_read(objset_t *os, uint64_t object, uint64_t offset, uint64_t size, 1097 void *buf, uint32_t flags) 1098 { 1099 dnode_t *dn; 1100 int err; 1101 1102 err = dnode_hold(os, object, FTAG, &dn); 1103 if (err != 0) 1104 return (err); 1105 1106 err = dmu_read_impl(dn, offset, size, buf, flags); 1107 dnode_rele(dn, FTAG); 1108 return (err); 1109 } 1110 1111 int 1112 dmu_read_by_dnode(dnode_t *dn, uint64_t offset, uint64_t size, void *buf, 1113 uint32_t flags) 1114 { 1115 return (dmu_read_impl(dn, offset, size, buf, flags)); 1116 } 1117 1118 static void 1119 dmu_write_impl(dmu_buf_t **dbp, int numbufs, uint64_t offset, uint64_t size, 1120 const void *buf, dmu_tx_t *tx) 1121 { 1122 int i; 1123 1124 for (i = 0; i < numbufs; i++) { 1125 uint64_t tocpy; 1126 int64_t bufoff; 1127 dmu_buf_t *db = dbp[i]; 1128 1129 ASSERT(size > 0); 1130 1131 bufoff = offset - db->db_offset; 1132 tocpy = MIN(db->db_size - bufoff, size); 1133 1134 ASSERT(i == 0 || i == numbufs-1 || tocpy == db->db_size); 1135 1136 if (tocpy == db->db_size) 1137 dmu_buf_will_fill(db, tx, B_FALSE); 1138 else 1139 dmu_buf_will_dirty(db, tx); 1140 1141 (void) memcpy((char *)db->db_data + bufoff, buf, tocpy); 1142 1143 if (tocpy == db->db_size) 1144 dmu_buf_fill_done(db, tx, B_FALSE); 1145 1146 offset += tocpy; 1147 size -= tocpy; 1148 buf = (char *)buf + tocpy; 1149 } 1150 } 1151 1152 void 1153 dmu_write(objset_t *os, uint64_t object, uint64_t offset, uint64_t size, 1154 const void *buf, dmu_tx_t *tx) 1155 { 1156 dmu_buf_t **dbp; 1157 int numbufs; 1158 1159 if (size == 0) 1160 return; 1161 1162 VERIFY0(dmu_buf_hold_array(os, object, offset, size, 1163 FALSE, FTAG, &numbufs, &dbp)); 1164 dmu_write_impl(dbp, numbufs, offset, size, buf, tx); 1165 dmu_buf_rele_array(dbp, numbufs, FTAG); 1166 } 1167 1168 /* 1169 * Note: Lustre is an external consumer of this interface. 1170 */ 1171 void 1172 dmu_write_by_dnode(dnode_t *dn, uint64_t offset, uint64_t size, 1173 const void *buf, dmu_tx_t *tx) 1174 { 1175 dmu_buf_t **dbp; 1176 int numbufs; 1177 1178 if (size == 0) 1179 return; 1180 1181 VERIFY0(dmu_buf_hold_array_by_dnode(dn, offset, size, 1182 FALSE, FTAG, &numbufs, &dbp, DMU_READ_PREFETCH)); 1183 dmu_write_impl(dbp, numbufs, offset, size, buf, tx); 1184 dmu_buf_rele_array(dbp, numbufs, FTAG); 1185 } 1186 1187 void 1188 dmu_prealloc(objset_t *os, uint64_t object, uint64_t offset, uint64_t size, 1189 dmu_tx_t *tx) 1190 { 1191 dmu_buf_t **dbp; 1192 int numbufs, i; 1193 1194 if (size == 0) 1195 return; 1196 1197 VERIFY(0 == dmu_buf_hold_array(os, object, offset, size, 1198 FALSE, FTAG, &numbufs, &dbp)); 1199 1200 for (i = 0; i < numbufs; i++) { 1201 dmu_buf_t *db = dbp[i]; 1202 1203 dmu_buf_will_not_fill(db, tx); 1204 } 1205 dmu_buf_rele_array(dbp, numbufs, FTAG); 1206 } 1207 1208 void 1209 dmu_write_embedded(objset_t *os, uint64_t object, uint64_t offset, 1210 void *data, uint8_t etype, uint8_t comp, int uncompressed_size, 1211 int compressed_size, int byteorder, dmu_tx_t *tx) 1212 { 1213 dmu_buf_t *db; 1214 1215 ASSERT3U(etype, <, NUM_BP_EMBEDDED_TYPES); 1216 ASSERT3U(comp, <, ZIO_COMPRESS_FUNCTIONS); 1217 VERIFY0(dmu_buf_hold_noread(os, object, offset, 1218 FTAG, &db)); 1219 1220 dmu_buf_write_embedded(db, 1221 data, (bp_embedded_type_t)etype, (enum zio_compress)comp, 1222 uncompressed_size, compressed_size, byteorder, tx); 1223 1224 dmu_buf_rele(db, FTAG); 1225 } 1226 1227 void 1228 dmu_redact(objset_t *os, uint64_t object, uint64_t offset, uint64_t size, 1229 dmu_tx_t *tx) 1230 { 1231 int numbufs, i; 1232 dmu_buf_t **dbp; 1233 1234 VERIFY0(dmu_buf_hold_array(os, object, offset, size, FALSE, FTAG, 1235 &numbufs, &dbp)); 1236 for (i = 0; i < numbufs; i++) 1237 dmu_buf_redact(dbp[i], tx); 1238 dmu_buf_rele_array(dbp, numbufs, FTAG); 1239 } 1240 1241 #ifdef _KERNEL 1242 int 1243 dmu_read_uio_dnode(dnode_t *dn, zfs_uio_t *uio, uint64_t size) 1244 { 1245 dmu_buf_t **dbp; 1246 int numbufs, i, err; 1247 1248 /* 1249 * NB: we could do this block-at-a-time, but it's nice 1250 * to be reading in parallel. 1251 */ 1252 err = dmu_buf_hold_array_by_dnode(dn, zfs_uio_offset(uio), size, 1253 TRUE, FTAG, &numbufs, &dbp, 0); 1254 if (err) 1255 return (err); 1256 1257 for (i = 0; i < numbufs; i++) { 1258 uint64_t tocpy; 1259 int64_t bufoff; 1260 dmu_buf_t *db = dbp[i]; 1261 1262 ASSERT(size > 0); 1263 1264 bufoff = zfs_uio_offset(uio) - db->db_offset; 1265 tocpy = MIN(db->db_size - bufoff, size); 1266 1267 err = zfs_uio_fault_move((char *)db->db_data + bufoff, tocpy, 1268 UIO_READ, uio); 1269 1270 if (err) 1271 break; 1272 1273 size -= tocpy; 1274 } 1275 dmu_buf_rele_array(dbp, numbufs, FTAG); 1276 1277 return (err); 1278 } 1279 1280 /* 1281 * Read 'size' bytes into the uio buffer. 1282 * From object zdb->db_object. 1283 * Starting at zfs_uio_offset(uio). 1284 * 1285 * If the caller already has a dbuf in the target object 1286 * (e.g. its bonus buffer), this routine is faster than dmu_read_uio(), 1287 * because we don't have to find the dnode_t for the object. 1288 */ 1289 int 1290 dmu_read_uio_dbuf(dmu_buf_t *zdb, zfs_uio_t *uio, uint64_t size) 1291 { 1292 dmu_buf_impl_t *db = (dmu_buf_impl_t *)zdb; 1293 dnode_t *dn; 1294 int err; 1295 1296 if (size == 0) 1297 return (0); 1298 1299 DB_DNODE_ENTER(db); 1300 dn = DB_DNODE(db); 1301 err = dmu_read_uio_dnode(dn, uio, size); 1302 DB_DNODE_EXIT(db); 1303 1304 return (err); 1305 } 1306 1307 /* 1308 * Read 'size' bytes into the uio buffer. 1309 * From the specified object 1310 * Starting at offset zfs_uio_offset(uio). 1311 */ 1312 int 1313 dmu_read_uio(objset_t *os, uint64_t object, zfs_uio_t *uio, uint64_t size) 1314 { 1315 dnode_t *dn; 1316 int err; 1317 1318 if (size == 0) 1319 return (0); 1320 1321 err = dnode_hold(os, object, FTAG, &dn); 1322 if (err) 1323 return (err); 1324 1325 err = dmu_read_uio_dnode(dn, uio, size); 1326 1327 dnode_rele(dn, FTAG); 1328 1329 return (err); 1330 } 1331 1332 int 1333 dmu_write_uio_dnode(dnode_t *dn, zfs_uio_t *uio, uint64_t size, dmu_tx_t *tx) 1334 { 1335 dmu_buf_t **dbp; 1336 int numbufs; 1337 int err = 0; 1338 int i; 1339 1340 err = dmu_buf_hold_array_by_dnode(dn, zfs_uio_offset(uio), size, 1341 FALSE, FTAG, &numbufs, &dbp, DMU_READ_PREFETCH); 1342 if (err) 1343 return (err); 1344 1345 for (i = 0; i < numbufs; i++) { 1346 uint64_t tocpy; 1347 int64_t bufoff; 1348 dmu_buf_t *db = dbp[i]; 1349 1350 ASSERT(size > 0); 1351 1352 offset_t off = zfs_uio_offset(uio); 1353 bufoff = off - db->db_offset; 1354 tocpy = MIN(db->db_size - bufoff, size); 1355 1356 ASSERT(i == 0 || i == numbufs-1 || tocpy == db->db_size); 1357 1358 if (tocpy == db->db_size) 1359 dmu_buf_will_fill(db, tx, B_TRUE); 1360 else 1361 dmu_buf_will_dirty(db, tx); 1362 1363 err = zfs_uio_fault_move((char *)db->db_data + bufoff, 1364 tocpy, UIO_WRITE, uio); 1365 1366 if (tocpy == db->db_size && dmu_buf_fill_done(db, tx, err)) { 1367 /* The fill was reverted. Undo any uio progress. */ 1368 zfs_uio_advance(uio, off - zfs_uio_offset(uio)); 1369 } 1370 1371 if (err) 1372 break; 1373 1374 size -= tocpy; 1375 } 1376 1377 dmu_buf_rele_array(dbp, numbufs, FTAG); 1378 return (err); 1379 } 1380 1381 /* 1382 * Write 'size' bytes from the uio buffer. 1383 * To object zdb->db_object. 1384 * Starting at offset zfs_uio_offset(uio). 1385 * 1386 * If the caller already has a dbuf in the target object 1387 * (e.g. its bonus buffer), this routine is faster than dmu_write_uio(), 1388 * because we don't have to find the dnode_t for the object. 1389 */ 1390 int 1391 dmu_write_uio_dbuf(dmu_buf_t *zdb, zfs_uio_t *uio, uint64_t size, 1392 dmu_tx_t *tx) 1393 { 1394 dmu_buf_impl_t *db = (dmu_buf_impl_t *)zdb; 1395 dnode_t *dn; 1396 int err; 1397 1398 if (size == 0) 1399 return (0); 1400 1401 DB_DNODE_ENTER(db); 1402 dn = DB_DNODE(db); 1403 err = dmu_write_uio_dnode(dn, uio, size, tx); 1404 DB_DNODE_EXIT(db); 1405 1406 return (err); 1407 } 1408 1409 /* 1410 * Write 'size' bytes from the uio buffer. 1411 * To the specified object. 1412 * Starting at offset zfs_uio_offset(uio). 1413 */ 1414 int 1415 dmu_write_uio(objset_t *os, uint64_t object, zfs_uio_t *uio, uint64_t size, 1416 dmu_tx_t *tx) 1417 { 1418 dnode_t *dn; 1419 int err; 1420 1421 if (size == 0) 1422 return (0); 1423 1424 err = dnode_hold(os, object, FTAG, &dn); 1425 if (err) 1426 return (err); 1427 1428 err = dmu_write_uio_dnode(dn, uio, size, tx); 1429 1430 dnode_rele(dn, FTAG); 1431 1432 return (err); 1433 } 1434 #endif /* _KERNEL */ 1435 1436 /* 1437 * Allocate a loaned anonymous arc buffer. 1438 */ 1439 arc_buf_t * 1440 dmu_request_arcbuf(dmu_buf_t *handle, int size) 1441 { 1442 dmu_buf_impl_t *db = (dmu_buf_impl_t *)handle; 1443 1444 return (arc_loan_buf(db->db_objset->os_spa, B_FALSE, size)); 1445 } 1446 1447 /* 1448 * Free a loaned arc buffer. 1449 */ 1450 void 1451 dmu_return_arcbuf(arc_buf_t *buf) 1452 { 1453 arc_return_buf(buf, FTAG); 1454 arc_buf_destroy(buf, FTAG); 1455 } 1456 1457 /* 1458 * A "lightweight" write is faster than a regular write (e.g. 1459 * dmu_write_by_dnode() or dmu_assign_arcbuf_by_dnode()), because it avoids the 1460 * CPU cost of creating a dmu_buf_impl_t and arc_buf_[hdr_]_t. However, the 1461 * data can not be read or overwritten until the transaction's txg has been 1462 * synced. This makes it appropriate for workloads that are known to be 1463 * (temporarily) write-only, like "zfs receive". 1464 * 1465 * A single block is written, starting at the specified offset in bytes. If 1466 * the call is successful, it returns 0 and the provided abd has been 1467 * consumed (the caller should not free it). 1468 */ 1469 int 1470 dmu_lightweight_write_by_dnode(dnode_t *dn, uint64_t offset, abd_t *abd, 1471 const zio_prop_t *zp, zio_flag_t flags, dmu_tx_t *tx) 1472 { 1473 dbuf_dirty_record_t *dr = 1474 dbuf_dirty_lightweight(dn, dbuf_whichblock(dn, 0, offset), tx); 1475 if (dr == NULL) 1476 return (SET_ERROR(EIO)); 1477 dr->dt.dll.dr_abd = abd; 1478 dr->dt.dll.dr_props = *zp; 1479 dr->dt.dll.dr_flags = flags; 1480 return (0); 1481 } 1482 1483 /* 1484 * When possible directly assign passed loaned arc buffer to a dbuf. 1485 * If this is not possible copy the contents of passed arc buf via 1486 * dmu_write(). 1487 */ 1488 int 1489 dmu_assign_arcbuf_by_dnode(dnode_t *dn, uint64_t offset, arc_buf_t *buf, 1490 dmu_tx_t *tx) 1491 { 1492 dmu_buf_impl_t *db; 1493 objset_t *os = dn->dn_objset; 1494 uint64_t object = dn->dn_object; 1495 uint32_t blksz = (uint32_t)arc_buf_lsize(buf); 1496 uint64_t blkid; 1497 1498 rw_enter(&dn->dn_struct_rwlock, RW_READER); 1499 blkid = dbuf_whichblock(dn, 0, offset); 1500 db = dbuf_hold(dn, blkid, FTAG); 1501 rw_exit(&dn->dn_struct_rwlock); 1502 if (db == NULL) 1503 return (SET_ERROR(EIO)); 1504 1505 /* 1506 * We can only assign if the offset is aligned and the arc buf is the 1507 * same size as the dbuf. 1508 */ 1509 if (offset == db->db.db_offset && blksz == db->db.db_size) { 1510 zfs_racct_write(blksz, 1); 1511 dbuf_assign_arcbuf(db, buf, tx); 1512 dbuf_rele(db, FTAG); 1513 } else { 1514 /* compressed bufs must always be assignable to their dbuf */ 1515 ASSERT3U(arc_get_compression(buf), ==, ZIO_COMPRESS_OFF); 1516 ASSERT(!(buf->b_flags & ARC_BUF_FLAG_COMPRESSED)); 1517 1518 dbuf_rele(db, FTAG); 1519 dmu_write(os, object, offset, blksz, buf->b_data, tx); 1520 dmu_return_arcbuf(buf); 1521 } 1522 1523 return (0); 1524 } 1525 1526 int 1527 dmu_assign_arcbuf_by_dbuf(dmu_buf_t *handle, uint64_t offset, arc_buf_t *buf, 1528 dmu_tx_t *tx) 1529 { 1530 int err; 1531 dmu_buf_impl_t *dbuf = (dmu_buf_impl_t *)handle; 1532 1533 DB_DNODE_ENTER(dbuf); 1534 err = dmu_assign_arcbuf_by_dnode(DB_DNODE(dbuf), offset, buf, tx); 1535 DB_DNODE_EXIT(dbuf); 1536 1537 return (err); 1538 } 1539 1540 typedef struct { 1541 dbuf_dirty_record_t *dsa_dr; 1542 dmu_sync_cb_t *dsa_done; 1543 zgd_t *dsa_zgd; 1544 dmu_tx_t *dsa_tx; 1545 } dmu_sync_arg_t; 1546 1547 static void 1548 dmu_sync_ready(zio_t *zio, arc_buf_t *buf, void *varg) 1549 { 1550 (void) buf; 1551 dmu_sync_arg_t *dsa = varg; 1552 dmu_buf_t *db = dsa->dsa_zgd->zgd_db; 1553 blkptr_t *bp = zio->io_bp; 1554 1555 if (zio->io_error == 0) { 1556 if (BP_IS_HOLE(bp)) { 1557 /* 1558 * A block of zeros may compress to a hole, but the 1559 * block size still needs to be known for replay. 1560 */ 1561 BP_SET_LSIZE(bp, db->db_size); 1562 } else if (!BP_IS_EMBEDDED(bp)) { 1563 ASSERT(BP_GET_LEVEL(bp) == 0); 1564 BP_SET_FILL(bp, 1); 1565 } 1566 } 1567 } 1568 1569 static void 1570 dmu_sync_late_arrival_ready(zio_t *zio) 1571 { 1572 dmu_sync_ready(zio, NULL, zio->io_private); 1573 } 1574 1575 static void 1576 dmu_sync_done(zio_t *zio, arc_buf_t *buf, void *varg) 1577 { 1578 (void) buf; 1579 dmu_sync_arg_t *dsa = varg; 1580 dbuf_dirty_record_t *dr = dsa->dsa_dr; 1581 dmu_buf_impl_t *db = dr->dr_dbuf; 1582 zgd_t *zgd = dsa->dsa_zgd; 1583 1584 /* 1585 * Record the vdev(s) backing this blkptr so they can be flushed after 1586 * the writes for the lwb have completed. 1587 */ 1588 if (zio->io_error == 0) { 1589 zil_lwb_add_block(zgd->zgd_lwb, zgd->zgd_bp); 1590 } 1591 1592 mutex_enter(&db->db_mtx); 1593 ASSERT(dr->dt.dl.dr_override_state == DR_IN_DMU_SYNC); 1594 if (zio->io_error == 0) { 1595 dr->dt.dl.dr_nopwrite = !!(zio->io_flags & ZIO_FLAG_NOPWRITE); 1596 if (dr->dt.dl.dr_nopwrite) { 1597 blkptr_t *bp = zio->io_bp; 1598 blkptr_t *bp_orig = &zio->io_bp_orig; 1599 uint8_t chksum = BP_GET_CHECKSUM(bp_orig); 1600 1601 ASSERT(BP_EQUAL(bp, bp_orig)); 1602 VERIFY(BP_EQUAL(bp, db->db_blkptr)); 1603 ASSERT(zio->io_prop.zp_compress != ZIO_COMPRESS_OFF); 1604 VERIFY(zio_checksum_table[chksum].ci_flags & 1605 ZCHECKSUM_FLAG_NOPWRITE); 1606 } 1607 dr->dt.dl.dr_overridden_by = *zio->io_bp; 1608 dr->dt.dl.dr_override_state = DR_OVERRIDDEN; 1609 dr->dt.dl.dr_copies = zio->io_prop.zp_copies; 1610 1611 /* 1612 * Old style holes are filled with all zeros, whereas 1613 * new-style holes maintain their lsize, type, level, 1614 * and birth time (see zio_write_compress). While we 1615 * need to reset the BP_SET_LSIZE() call that happened 1616 * in dmu_sync_ready for old style holes, we do *not* 1617 * want to wipe out the information contained in new 1618 * style holes. Thus, only zero out the block pointer if 1619 * it's an old style hole. 1620 */ 1621 if (BP_IS_HOLE(&dr->dt.dl.dr_overridden_by) && 1622 dr->dt.dl.dr_overridden_by.blk_birth == 0) 1623 BP_ZERO(&dr->dt.dl.dr_overridden_by); 1624 } else { 1625 dr->dt.dl.dr_override_state = DR_NOT_OVERRIDDEN; 1626 } 1627 cv_broadcast(&db->db_changed); 1628 mutex_exit(&db->db_mtx); 1629 1630 dsa->dsa_done(dsa->dsa_zgd, zio->io_error); 1631 1632 kmem_free(dsa, sizeof (*dsa)); 1633 } 1634 1635 static void 1636 dmu_sync_late_arrival_done(zio_t *zio) 1637 { 1638 blkptr_t *bp = zio->io_bp; 1639 dmu_sync_arg_t *dsa = zio->io_private; 1640 zgd_t *zgd = dsa->dsa_zgd; 1641 1642 if (zio->io_error == 0) { 1643 /* 1644 * Record the vdev(s) backing this blkptr so they can be 1645 * flushed after the writes for the lwb have completed. 1646 */ 1647 zil_lwb_add_block(zgd->zgd_lwb, zgd->zgd_bp); 1648 1649 if (!BP_IS_HOLE(bp)) { 1650 blkptr_t *bp_orig __maybe_unused = &zio->io_bp_orig; 1651 ASSERT(!(zio->io_flags & ZIO_FLAG_NOPWRITE)); 1652 ASSERT(BP_IS_HOLE(bp_orig) || !BP_EQUAL(bp, bp_orig)); 1653 ASSERT(zio->io_bp->blk_birth == zio->io_txg); 1654 ASSERT(zio->io_txg > spa_syncing_txg(zio->io_spa)); 1655 zio_free(zio->io_spa, zio->io_txg, zio->io_bp); 1656 } 1657 } 1658 1659 dmu_tx_commit(dsa->dsa_tx); 1660 1661 dsa->dsa_done(dsa->dsa_zgd, zio->io_error); 1662 1663 abd_free(zio->io_abd); 1664 kmem_free(dsa, sizeof (*dsa)); 1665 } 1666 1667 static int 1668 dmu_sync_late_arrival(zio_t *pio, objset_t *os, dmu_sync_cb_t *done, zgd_t *zgd, 1669 zio_prop_t *zp, zbookmark_phys_t *zb) 1670 { 1671 dmu_sync_arg_t *dsa; 1672 dmu_tx_t *tx; 1673 int error; 1674 1675 error = dbuf_read((dmu_buf_impl_t *)zgd->zgd_db, NULL, 1676 DB_RF_CANFAIL | DB_RF_NOPREFETCH); 1677 if (error != 0) 1678 return (error); 1679 1680 tx = dmu_tx_create(os); 1681 dmu_tx_hold_space(tx, zgd->zgd_db->db_size); 1682 /* 1683 * This transaction does not produce any dirty data or log blocks, so 1684 * it should not be throttled. All other cases wait for TXG sync, by 1685 * which time the log block we are writing will be obsolete, so we can 1686 * skip waiting and just return error here instead. 1687 */ 1688 if (dmu_tx_assign(tx, TXG_NOWAIT | TXG_NOTHROTTLE) != 0) { 1689 dmu_tx_abort(tx); 1690 /* Make zl_get_data do txg_waited_synced() */ 1691 return (SET_ERROR(EIO)); 1692 } 1693 1694 /* 1695 * In order to prevent the zgd's lwb from being free'd prior to 1696 * dmu_sync_late_arrival_done() being called, we have to ensure 1697 * the lwb's "max txg" takes this tx's txg into account. 1698 */ 1699 zil_lwb_add_txg(zgd->zgd_lwb, dmu_tx_get_txg(tx)); 1700 1701 dsa = kmem_alloc(sizeof (dmu_sync_arg_t), KM_SLEEP); 1702 dsa->dsa_dr = NULL; 1703 dsa->dsa_done = done; 1704 dsa->dsa_zgd = zgd; 1705 dsa->dsa_tx = tx; 1706 1707 /* 1708 * Since we are currently syncing this txg, it's nontrivial to 1709 * determine what BP to nopwrite against, so we disable nopwrite. 1710 * 1711 * When syncing, the db_blkptr is initially the BP of the previous 1712 * txg. We can not nopwrite against it because it will be changed 1713 * (this is similar to the non-late-arrival case where the dbuf is 1714 * dirty in a future txg). 1715 * 1716 * Then dbuf_write_ready() sets bp_blkptr to the location we will write. 1717 * We can not nopwrite against it because although the BP will not 1718 * (typically) be changed, the data has not yet been persisted to this 1719 * location. 1720 * 1721 * Finally, when dbuf_write_done() is called, it is theoretically 1722 * possible to always nopwrite, because the data that was written in 1723 * this txg is the same data that we are trying to write. However we 1724 * would need to check that this dbuf is not dirty in any future 1725 * txg's (as we do in the normal dmu_sync() path). For simplicity, we 1726 * don't nopwrite in this case. 1727 */ 1728 zp->zp_nopwrite = B_FALSE; 1729 1730 zio_nowait(zio_write(pio, os->os_spa, dmu_tx_get_txg(tx), zgd->zgd_bp, 1731 abd_get_from_buf(zgd->zgd_db->db_data, zgd->zgd_db->db_size), 1732 zgd->zgd_db->db_size, zgd->zgd_db->db_size, zp, 1733 dmu_sync_late_arrival_ready, NULL, dmu_sync_late_arrival_done, 1734 dsa, ZIO_PRIORITY_SYNC_WRITE, ZIO_FLAG_CANFAIL, zb)); 1735 1736 return (0); 1737 } 1738 1739 /* 1740 * Intent log support: sync the block associated with db to disk. 1741 * N.B. and XXX: the caller is responsible for making sure that the 1742 * data isn't changing while dmu_sync() is writing it. 1743 * 1744 * Return values: 1745 * 1746 * EEXIST: this txg has already been synced, so there's nothing to do. 1747 * The caller should not log the write. 1748 * 1749 * ENOENT: the block was dbuf_free_range()'d, so there's nothing to do. 1750 * The caller should not log the write. 1751 * 1752 * EALREADY: this block is already in the process of being synced. 1753 * The caller should track its progress (somehow). 1754 * 1755 * EIO: could not do the I/O. 1756 * The caller should do a txg_wait_synced(). 1757 * 1758 * 0: the I/O has been initiated. 1759 * The caller should log this blkptr in the done callback. 1760 * It is possible that the I/O will fail, in which case 1761 * the error will be reported to the done callback and 1762 * propagated to pio from zio_done(). 1763 */ 1764 int 1765 dmu_sync(zio_t *pio, uint64_t txg, dmu_sync_cb_t *done, zgd_t *zgd) 1766 { 1767 dmu_buf_impl_t *db = (dmu_buf_impl_t *)zgd->zgd_db; 1768 objset_t *os = db->db_objset; 1769 dsl_dataset_t *ds = os->os_dsl_dataset; 1770 dbuf_dirty_record_t *dr, *dr_next; 1771 dmu_sync_arg_t *dsa; 1772 zbookmark_phys_t zb; 1773 zio_prop_t zp; 1774 dnode_t *dn; 1775 1776 ASSERT(pio != NULL); 1777 ASSERT(txg != 0); 1778 1779 SET_BOOKMARK(&zb, ds->ds_object, 1780 db->db.db_object, db->db_level, db->db_blkid); 1781 1782 DB_DNODE_ENTER(db); 1783 dn = DB_DNODE(db); 1784 dmu_write_policy(os, dn, db->db_level, WP_DMU_SYNC, &zp); 1785 DB_DNODE_EXIT(db); 1786 1787 /* 1788 * If we're frozen (running ziltest), we always need to generate a bp. 1789 */ 1790 if (txg > spa_freeze_txg(os->os_spa)) 1791 return (dmu_sync_late_arrival(pio, os, done, zgd, &zp, &zb)); 1792 1793 /* 1794 * Grabbing db_mtx now provides a barrier between dbuf_sync_leaf() 1795 * and us. If we determine that this txg is not yet syncing, 1796 * but it begins to sync a moment later, that's OK because the 1797 * sync thread will block in dbuf_sync_leaf() until we drop db_mtx. 1798 */ 1799 mutex_enter(&db->db_mtx); 1800 1801 if (txg <= spa_last_synced_txg(os->os_spa)) { 1802 /* 1803 * This txg has already synced. There's nothing to do. 1804 */ 1805 mutex_exit(&db->db_mtx); 1806 return (SET_ERROR(EEXIST)); 1807 } 1808 1809 if (txg <= spa_syncing_txg(os->os_spa)) { 1810 /* 1811 * This txg is currently syncing, so we can't mess with 1812 * the dirty record anymore; just write a new log block. 1813 */ 1814 mutex_exit(&db->db_mtx); 1815 return (dmu_sync_late_arrival(pio, os, done, zgd, &zp, &zb)); 1816 } 1817 1818 dr = dbuf_find_dirty_eq(db, txg); 1819 1820 if (dr == NULL) { 1821 /* 1822 * There's no dr for this dbuf, so it must have been freed. 1823 * There's no need to log writes to freed blocks, so we're done. 1824 */ 1825 mutex_exit(&db->db_mtx); 1826 return (SET_ERROR(ENOENT)); 1827 } 1828 1829 dr_next = list_next(&db->db_dirty_records, dr); 1830 ASSERT(dr_next == NULL || dr_next->dr_txg < txg); 1831 1832 if (db->db_blkptr != NULL) { 1833 /* 1834 * We need to fill in zgd_bp with the current blkptr so that 1835 * the nopwrite code can check if we're writing the same 1836 * data that's already on disk. We can only nopwrite if we 1837 * are sure that after making the copy, db_blkptr will not 1838 * change until our i/o completes. We ensure this by 1839 * holding the db_mtx, and only allowing nopwrite if the 1840 * block is not already dirty (see below). This is verified 1841 * by dmu_sync_done(), which VERIFYs that the db_blkptr has 1842 * not changed. 1843 */ 1844 *zgd->zgd_bp = *db->db_blkptr; 1845 } 1846 1847 /* 1848 * Assume the on-disk data is X, the current syncing data (in 1849 * txg - 1) is Y, and the current in-memory data is Z (currently 1850 * in dmu_sync). 1851 * 1852 * We usually want to perform a nopwrite if X and Z are the 1853 * same. However, if Y is different (i.e. the BP is going to 1854 * change before this write takes effect), then a nopwrite will 1855 * be incorrect - we would override with X, which could have 1856 * been freed when Y was written. 1857 * 1858 * (Note that this is not a concern when we are nop-writing from 1859 * syncing context, because X and Y must be identical, because 1860 * all previous txgs have been synced.) 1861 * 1862 * Therefore, we disable nopwrite if the current BP could change 1863 * before this TXG. There are two ways it could change: by 1864 * being dirty (dr_next is non-NULL), or by being freed 1865 * (dnode_block_freed()). This behavior is verified by 1866 * zio_done(), which VERIFYs that the override BP is identical 1867 * to the on-disk BP. 1868 */ 1869 DB_DNODE_ENTER(db); 1870 dn = DB_DNODE(db); 1871 if (dr_next != NULL || dnode_block_freed(dn, db->db_blkid)) 1872 zp.zp_nopwrite = B_FALSE; 1873 DB_DNODE_EXIT(db); 1874 1875 ASSERT(dr->dr_txg == txg); 1876 if (dr->dt.dl.dr_override_state == DR_IN_DMU_SYNC || 1877 dr->dt.dl.dr_override_state == DR_OVERRIDDEN) { 1878 /* 1879 * We have already issued a sync write for this buffer, 1880 * or this buffer has already been synced. It could not 1881 * have been dirtied since, or we would have cleared the state. 1882 */ 1883 mutex_exit(&db->db_mtx); 1884 return (SET_ERROR(EALREADY)); 1885 } 1886 1887 ASSERT(dr->dt.dl.dr_override_state == DR_NOT_OVERRIDDEN); 1888 dr->dt.dl.dr_override_state = DR_IN_DMU_SYNC; 1889 mutex_exit(&db->db_mtx); 1890 1891 dsa = kmem_alloc(sizeof (dmu_sync_arg_t), KM_SLEEP); 1892 dsa->dsa_dr = dr; 1893 dsa->dsa_done = done; 1894 dsa->dsa_zgd = zgd; 1895 dsa->dsa_tx = NULL; 1896 1897 zio_nowait(arc_write(pio, os->os_spa, txg, zgd->zgd_bp, 1898 dr->dt.dl.dr_data, !DBUF_IS_CACHEABLE(db), dbuf_is_l2cacheable(db), 1899 &zp, dmu_sync_ready, NULL, dmu_sync_done, dsa, 1900 ZIO_PRIORITY_SYNC_WRITE, ZIO_FLAG_CANFAIL, &zb)); 1901 1902 return (0); 1903 } 1904 1905 int 1906 dmu_object_set_nlevels(objset_t *os, uint64_t object, int nlevels, dmu_tx_t *tx) 1907 { 1908 dnode_t *dn; 1909 int err; 1910 1911 err = dnode_hold(os, object, FTAG, &dn); 1912 if (err) 1913 return (err); 1914 err = dnode_set_nlevels(dn, nlevels, tx); 1915 dnode_rele(dn, FTAG); 1916 return (err); 1917 } 1918 1919 int 1920 dmu_object_set_blocksize(objset_t *os, uint64_t object, uint64_t size, int ibs, 1921 dmu_tx_t *tx) 1922 { 1923 dnode_t *dn; 1924 int err; 1925 1926 err = dnode_hold(os, object, FTAG, &dn); 1927 if (err) 1928 return (err); 1929 err = dnode_set_blksz(dn, size, ibs, tx); 1930 dnode_rele(dn, FTAG); 1931 return (err); 1932 } 1933 1934 int 1935 dmu_object_set_maxblkid(objset_t *os, uint64_t object, uint64_t maxblkid, 1936 dmu_tx_t *tx) 1937 { 1938 dnode_t *dn; 1939 int err; 1940 1941 err = dnode_hold(os, object, FTAG, &dn); 1942 if (err) 1943 return (err); 1944 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 1945 dnode_new_blkid(dn, maxblkid, tx, B_FALSE, B_TRUE); 1946 rw_exit(&dn->dn_struct_rwlock); 1947 dnode_rele(dn, FTAG); 1948 return (0); 1949 } 1950 1951 void 1952 dmu_object_set_checksum(objset_t *os, uint64_t object, uint8_t checksum, 1953 dmu_tx_t *tx) 1954 { 1955 dnode_t *dn; 1956 1957 /* 1958 * Send streams include each object's checksum function. This 1959 * check ensures that the receiving system can understand the 1960 * checksum function transmitted. 1961 */ 1962 ASSERT3U(checksum, <, ZIO_CHECKSUM_LEGACY_FUNCTIONS); 1963 1964 VERIFY0(dnode_hold(os, object, FTAG, &dn)); 1965 ASSERT3U(checksum, <, ZIO_CHECKSUM_FUNCTIONS); 1966 dn->dn_checksum = checksum; 1967 dnode_setdirty(dn, tx); 1968 dnode_rele(dn, FTAG); 1969 } 1970 1971 void 1972 dmu_object_set_compress(objset_t *os, uint64_t object, uint8_t compress, 1973 dmu_tx_t *tx) 1974 { 1975 dnode_t *dn; 1976 1977 /* 1978 * Send streams include each object's compression function. This 1979 * check ensures that the receiving system can understand the 1980 * compression function transmitted. 1981 */ 1982 ASSERT3U(compress, <, ZIO_COMPRESS_LEGACY_FUNCTIONS); 1983 1984 VERIFY0(dnode_hold(os, object, FTAG, &dn)); 1985 dn->dn_compress = compress; 1986 dnode_setdirty(dn, tx); 1987 dnode_rele(dn, FTAG); 1988 } 1989 1990 /* 1991 * When the "redundant_metadata" property is set to "most", only indirect 1992 * blocks of this level and higher will have an additional ditto block. 1993 */ 1994 static const int zfs_redundant_metadata_most_ditto_level = 2; 1995 1996 void 1997 dmu_write_policy(objset_t *os, dnode_t *dn, int level, int wp, zio_prop_t *zp) 1998 { 1999 dmu_object_type_t type = dn ? dn->dn_type : DMU_OT_OBJSET; 2000 boolean_t ismd = (level > 0 || DMU_OT_IS_METADATA(type) || 2001 (wp & WP_SPILL)); 2002 enum zio_checksum checksum = os->os_checksum; 2003 enum zio_compress compress = os->os_compress; 2004 uint8_t complevel = os->os_complevel; 2005 enum zio_checksum dedup_checksum = os->os_dedup_checksum; 2006 boolean_t dedup = B_FALSE; 2007 boolean_t nopwrite = B_FALSE; 2008 boolean_t dedup_verify = os->os_dedup_verify; 2009 boolean_t encrypt = B_FALSE; 2010 int copies = os->os_copies; 2011 2012 /* 2013 * We maintain different write policies for each of the following 2014 * types of data: 2015 * 1. metadata 2016 * 2. preallocated blocks (i.e. level-0 blocks of a dump device) 2017 * 3. all other level 0 blocks 2018 */ 2019 if (ismd) { 2020 /* 2021 * XXX -- we should design a compression algorithm 2022 * that specializes in arrays of bps. 2023 */ 2024 compress = zio_compress_select(os->os_spa, 2025 ZIO_COMPRESS_ON, ZIO_COMPRESS_ON); 2026 2027 /* 2028 * Metadata always gets checksummed. If the data 2029 * checksum is multi-bit correctable, and it's not a 2030 * ZBT-style checksum, then it's suitable for metadata 2031 * as well. Otherwise, the metadata checksum defaults 2032 * to fletcher4. 2033 */ 2034 if (!(zio_checksum_table[checksum].ci_flags & 2035 ZCHECKSUM_FLAG_METADATA) || 2036 (zio_checksum_table[checksum].ci_flags & 2037 ZCHECKSUM_FLAG_EMBEDDED)) 2038 checksum = ZIO_CHECKSUM_FLETCHER_4; 2039 2040 switch (os->os_redundant_metadata) { 2041 case ZFS_REDUNDANT_METADATA_ALL: 2042 copies++; 2043 break; 2044 case ZFS_REDUNDANT_METADATA_MOST: 2045 if (level >= zfs_redundant_metadata_most_ditto_level || 2046 DMU_OT_IS_METADATA(type) || (wp & WP_SPILL)) 2047 copies++; 2048 break; 2049 case ZFS_REDUNDANT_METADATA_SOME: 2050 if (DMU_OT_IS_CRITICAL(type)) 2051 copies++; 2052 break; 2053 case ZFS_REDUNDANT_METADATA_NONE: 2054 break; 2055 } 2056 } else if (wp & WP_NOFILL) { 2057 ASSERT(level == 0); 2058 2059 /* 2060 * If we're writing preallocated blocks, we aren't actually 2061 * writing them so don't set any policy properties. These 2062 * blocks are currently only used by an external subsystem 2063 * outside of zfs (i.e. dump) and not written by the zio 2064 * pipeline. 2065 */ 2066 compress = ZIO_COMPRESS_OFF; 2067 checksum = ZIO_CHECKSUM_OFF; 2068 } else { 2069 compress = zio_compress_select(os->os_spa, dn->dn_compress, 2070 compress); 2071 complevel = zio_complevel_select(os->os_spa, compress, 2072 complevel, complevel); 2073 2074 checksum = (dedup_checksum == ZIO_CHECKSUM_OFF) ? 2075 zio_checksum_select(dn->dn_checksum, checksum) : 2076 dedup_checksum; 2077 2078 /* 2079 * Determine dedup setting. If we are in dmu_sync(), 2080 * we won't actually dedup now because that's all 2081 * done in syncing context; but we do want to use the 2082 * dedup checksum. If the checksum is not strong 2083 * enough to ensure unique signatures, force 2084 * dedup_verify. 2085 */ 2086 if (dedup_checksum != ZIO_CHECKSUM_OFF) { 2087 dedup = (wp & WP_DMU_SYNC) ? B_FALSE : B_TRUE; 2088 if (!(zio_checksum_table[checksum].ci_flags & 2089 ZCHECKSUM_FLAG_DEDUP)) 2090 dedup_verify = B_TRUE; 2091 } 2092 2093 /* 2094 * Enable nopwrite if we have secure enough checksum 2095 * algorithm (see comment in zio_nop_write) and 2096 * compression is enabled. We don't enable nopwrite if 2097 * dedup is enabled as the two features are mutually 2098 * exclusive. 2099 */ 2100 nopwrite = (!dedup && (zio_checksum_table[checksum].ci_flags & 2101 ZCHECKSUM_FLAG_NOPWRITE) && 2102 compress != ZIO_COMPRESS_OFF && zfs_nopwrite_enabled); 2103 } 2104 2105 /* 2106 * All objects in an encrypted objset are protected from modification 2107 * via a MAC. Encrypted objects store their IV and salt in the last DVA 2108 * in the bp, so we cannot use all copies. Encrypted objects are also 2109 * not subject to nopwrite since writing the same data will still 2110 * result in a new ciphertext. Only encrypted blocks can be dedup'd 2111 * to avoid ambiguity in the dedup code since the DDT does not store 2112 * object types. 2113 */ 2114 if (os->os_encrypted && (wp & WP_NOFILL) == 0) { 2115 encrypt = B_TRUE; 2116 2117 if (DMU_OT_IS_ENCRYPTED(type)) { 2118 copies = MIN(copies, SPA_DVAS_PER_BP - 1); 2119 nopwrite = B_FALSE; 2120 } else { 2121 dedup = B_FALSE; 2122 } 2123 2124 if (level <= 0 && 2125 (type == DMU_OT_DNODE || type == DMU_OT_OBJSET)) { 2126 compress = ZIO_COMPRESS_EMPTY; 2127 } 2128 } 2129 2130 zp->zp_compress = compress; 2131 zp->zp_complevel = complevel; 2132 zp->zp_checksum = checksum; 2133 zp->zp_type = (wp & WP_SPILL) ? dn->dn_bonustype : type; 2134 zp->zp_level = level; 2135 zp->zp_copies = MIN(copies, spa_max_replication(os->os_spa)); 2136 zp->zp_dedup = dedup; 2137 zp->zp_dedup_verify = dedup && dedup_verify; 2138 zp->zp_nopwrite = nopwrite; 2139 zp->zp_encrypt = encrypt; 2140 zp->zp_byteorder = ZFS_HOST_BYTEORDER; 2141 memset(zp->zp_salt, 0, ZIO_DATA_SALT_LEN); 2142 memset(zp->zp_iv, 0, ZIO_DATA_IV_LEN); 2143 memset(zp->zp_mac, 0, ZIO_DATA_MAC_LEN); 2144 zp->zp_zpl_smallblk = DMU_OT_IS_FILE(zp->zp_type) ? 2145 os->os_zpl_special_smallblock : 0; 2146 2147 ASSERT3U(zp->zp_compress, !=, ZIO_COMPRESS_INHERIT); 2148 } 2149 2150 /* 2151 * Reports the location of data and holes in an object. In order to 2152 * accurately report holes all dirty data must be synced to disk. This 2153 * causes extremely poor performance when seeking for holes in a dirty file. 2154 * As a compromise, only provide hole data when the dnode is clean. When 2155 * a dnode is dirty report the dnode as having no holes by returning EBUSY 2156 * which is always safe to do. 2157 */ 2158 int 2159 dmu_offset_next(objset_t *os, uint64_t object, boolean_t hole, uint64_t *off) 2160 { 2161 dnode_t *dn; 2162 int restarted = 0, err; 2163 2164 restart: 2165 err = dnode_hold(os, object, FTAG, &dn); 2166 if (err) 2167 return (err); 2168 2169 rw_enter(&dn->dn_struct_rwlock, RW_READER); 2170 2171 if (dnode_is_dirty(dn)) { 2172 /* 2173 * If the zfs_dmu_offset_next_sync module option is enabled 2174 * then hole reporting has been requested. Dirty dnodes 2175 * must be synced to disk to accurately report holes. 2176 * 2177 * Provided a RL_READER rangelock spanning 0-UINT64_MAX is 2178 * held by the caller only a single restart will be required. 2179 * We tolerate callers which do not hold the rangelock by 2180 * returning EBUSY and not reporting holes after one restart. 2181 */ 2182 if (zfs_dmu_offset_next_sync) { 2183 rw_exit(&dn->dn_struct_rwlock); 2184 dnode_rele(dn, FTAG); 2185 2186 if (restarted) 2187 return (SET_ERROR(EBUSY)); 2188 2189 txg_wait_synced(dmu_objset_pool(os), 0); 2190 restarted = 1; 2191 goto restart; 2192 } 2193 2194 err = SET_ERROR(EBUSY); 2195 } else { 2196 err = dnode_next_offset(dn, DNODE_FIND_HAVELOCK | 2197 (hole ? DNODE_FIND_HOLE : 0), off, 1, 1, 0); 2198 } 2199 2200 rw_exit(&dn->dn_struct_rwlock); 2201 dnode_rele(dn, FTAG); 2202 2203 return (err); 2204 } 2205 2206 int 2207 dmu_read_l0_bps(objset_t *os, uint64_t object, uint64_t offset, uint64_t length, 2208 blkptr_t *bps, size_t *nbpsp) 2209 { 2210 dmu_buf_t **dbp, *dbuf; 2211 dmu_buf_impl_t *db; 2212 blkptr_t *bp; 2213 int error, numbufs; 2214 2215 error = dmu_buf_hold_array(os, object, offset, length, FALSE, FTAG, 2216 &numbufs, &dbp); 2217 if (error != 0) { 2218 if (error == ESRCH) { 2219 error = SET_ERROR(ENXIO); 2220 } 2221 return (error); 2222 } 2223 2224 ASSERT3U(numbufs, <=, *nbpsp); 2225 2226 for (int i = 0; i < numbufs; i++) { 2227 dbuf = dbp[i]; 2228 db = (dmu_buf_impl_t *)dbuf; 2229 2230 mutex_enter(&db->db_mtx); 2231 2232 if (!list_is_empty(&db->db_dirty_records)) { 2233 dbuf_dirty_record_t *dr; 2234 2235 dr = list_head(&db->db_dirty_records); 2236 if (dr->dt.dl.dr_brtwrite) { 2237 /* 2238 * This is very special case where we clone a 2239 * block and in the same transaction group we 2240 * read its BP (most likely to clone the clone). 2241 */ 2242 bp = &dr->dt.dl.dr_overridden_by; 2243 } else { 2244 /* 2245 * The block was modified in the same 2246 * transaction group. 2247 */ 2248 mutex_exit(&db->db_mtx); 2249 error = SET_ERROR(EAGAIN); 2250 goto out; 2251 } 2252 } else { 2253 bp = db->db_blkptr; 2254 } 2255 2256 mutex_exit(&db->db_mtx); 2257 2258 if (bp == NULL) { 2259 /* 2260 * The block was created in this transaction group, 2261 * so it has no BP yet. 2262 */ 2263 error = SET_ERROR(EAGAIN); 2264 goto out; 2265 } 2266 /* 2267 * Make sure we clone only data blocks. 2268 */ 2269 if (BP_IS_METADATA(bp) && !BP_IS_HOLE(bp)) { 2270 error = SET_ERROR(EINVAL); 2271 goto out; 2272 } 2273 2274 /* 2275 * If the block was allocated in transaction group that is not 2276 * yet synced, we could clone it, but we couldn't write this 2277 * operation into ZIL, or it may be impossible to replay, since 2278 * the block may appear not yet allocated at that point. 2279 */ 2280 if (BP_PHYSICAL_BIRTH(bp) > spa_freeze_txg(os->os_spa)) { 2281 error = SET_ERROR(EINVAL); 2282 goto out; 2283 } 2284 if (BP_PHYSICAL_BIRTH(bp) > spa_last_synced_txg(os->os_spa)) { 2285 error = SET_ERROR(EAGAIN); 2286 goto out; 2287 } 2288 2289 bps[i] = *bp; 2290 } 2291 2292 *nbpsp = numbufs; 2293 out: 2294 dmu_buf_rele_array(dbp, numbufs, FTAG); 2295 2296 return (error); 2297 } 2298 2299 int 2300 dmu_brt_clone(objset_t *os, uint64_t object, uint64_t offset, uint64_t length, 2301 dmu_tx_t *tx, const blkptr_t *bps, size_t nbps) 2302 { 2303 spa_t *spa; 2304 dmu_buf_t **dbp, *dbuf; 2305 dmu_buf_impl_t *db; 2306 struct dirty_leaf *dl; 2307 dbuf_dirty_record_t *dr; 2308 const blkptr_t *bp; 2309 int error = 0, i, numbufs; 2310 2311 spa = os->os_spa; 2312 2313 VERIFY0(dmu_buf_hold_array(os, object, offset, length, FALSE, FTAG, 2314 &numbufs, &dbp)); 2315 ASSERT3U(nbps, ==, numbufs); 2316 2317 /* 2318 * Before we start cloning make sure that the dbufs sizes match new BPs 2319 * sizes. If they don't, that's a no-go, as we are not able to shrink 2320 * dbufs. 2321 */ 2322 for (i = 0; i < numbufs; i++) { 2323 dbuf = dbp[i]; 2324 db = (dmu_buf_impl_t *)dbuf; 2325 bp = &bps[i]; 2326 2327 ASSERT0(db->db_level); 2328 ASSERT(db->db_blkid != DMU_BONUS_BLKID); 2329 ASSERT(db->db_blkid != DMU_SPILL_BLKID); 2330 2331 if (!BP_IS_HOLE(bp) && BP_GET_LSIZE(bp) != dbuf->db_size) { 2332 error = SET_ERROR(EXDEV); 2333 goto out; 2334 } 2335 } 2336 2337 for (i = 0; i < numbufs; i++) { 2338 dbuf = dbp[i]; 2339 db = (dmu_buf_impl_t *)dbuf; 2340 bp = &bps[i]; 2341 2342 ASSERT0(db->db_level); 2343 ASSERT(db->db_blkid != DMU_BONUS_BLKID); 2344 ASSERT(db->db_blkid != DMU_SPILL_BLKID); 2345 ASSERT(BP_IS_HOLE(bp) || dbuf->db_size == BP_GET_LSIZE(bp)); 2346 2347 dmu_buf_will_clone(dbuf, tx); 2348 2349 mutex_enter(&db->db_mtx); 2350 2351 dr = list_head(&db->db_dirty_records); 2352 VERIFY(dr != NULL); 2353 ASSERT3U(dr->dr_txg, ==, tx->tx_txg); 2354 dl = &dr->dt.dl; 2355 dl->dr_overridden_by = *bp; 2356 dl->dr_brtwrite = B_TRUE; 2357 dl->dr_override_state = DR_OVERRIDDEN; 2358 if (BP_IS_HOLE(bp)) { 2359 dl->dr_overridden_by.blk_birth = 0; 2360 dl->dr_overridden_by.blk_phys_birth = 0; 2361 } else { 2362 dl->dr_overridden_by.blk_birth = dr->dr_txg; 2363 if (!BP_IS_EMBEDDED(bp)) { 2364 dl->dr_overridden_by.blk_phys_birth = 2365 BP_PHYSICAL_BIRTH(bp); 2366 } 2367 } 2368 2369 mutex_exit(&db->db_mtx); 2370 2371 /* 2372 * When data in embedded into BP there is no need to create 2373 * BRT entry as there is no data block. Just copy the BP as 2374 * it contains the data. 2375 */ 2376 if (!BP_IS_HOLE(bp) && !BP_IS_EMBEDDED(bp)) { 2377 brt_pending_add(spa, bp, tx); 2378 } 2379 } 2380 out: 2381 dmu_buf_rele_array(dbp, numbufs, FTAG); 2382 2383 return (error); 2384 } 2385 2386 void 2387 __dmu_object_info_from_dnode(dnode_t *dn, dmu_object_info_t *doi) 2388 { 2389 dnode_phys_t *dnp = dn->dn_phys; 2390 2391 doi->doi_data_block_size = dn->dn_datablksz; 2392 doi->doi_metadata_block_size = dn->dn_indblkshift ? 2393 1ULL << dn->dn_indblkshift : 0; 2394 doi->doi_type = dn->dn_type; 2395 doi->doi_bonus_type = dn->dn_bonustype; 2396 doi->doi_bonus_size = dn->dn_bonuslen; 2397 doi->doi_dnodesize = dn->dn_num_slots << DNODE_SHIFT; 2398 doi->doi_indirection = dn->dn_nlevels; 2399 doi->doi_checksum = dn->dn_checksum; 2400 doi->doi_compress = dn->dn_compress; 2401 doi->doi_nblkptr = dn->dn_nblkptr; 2402 doi->doi_physical_blocks_512 = (DN_USED_BYTES(dnp) + 256) >> 9; 2403 doi->doi_max_offset = (dn->dn_maxblkid + 1) * dn->dn_datablksz; 2404 doi->doi_fill_count = 0; 2405 for (int i = 0; i < dnp->dn_nblkptr; i++) 2406 doi->doi_fill_count += BP_GET_FILL(&dnp->dn_blkptr[i]); 2407 } 2408 2409 void 2410 dmu_object_info_from_dnode(dnode_t *dn, dmu_object_info_t *doi) 2411 { 2412 rw_enter(&dn->dn_struct_rwlock, RW_READER); 2413 mutex_enter(&dn->dn_mtx); 2414 2415 __dmu_object_info_from_dnode(dn, doi); 2416 2417 mutex_exit(&dn->dn_mtx); 2418 rw_exit(&dn->dn_struct_rwlock); 2419 } 2420 2421 /* 2422 * Get information on a DMU object. 2423 * If doi is NULL, just indicates whether the object exists. 2424 */ 2425 int 2426 dmu_object_info(objset_t *os, uint64_t object, dmu_object_info_t *doi) 2427 { 2428 dnode_t *dn; 2429 int err = dnode_hold(os, object, FTAG, &dn); 2430 2431 if (err) 2432 return (err); 2433 2434 if (doi != NULL) 2435 dmu_object_info_from_dnode(dn, doi); 2436 2437 dnode_rele(dn, FTAG); 2438 return (0); 2439 } 2440 2441 /* 2442 * As above, but faster; can be used when you have a held dbuf in hand. 2443 */ 2444 void 2445 dmu_object_info_from_db(dmu_buf_t *db_fake, dmu_object_info_t *doi) 2446 { 2447 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake; 2448 2449 DB_DNODE_ENTER(db); 2450 dmu_object_info_from_dnode(DB_DNODE(db), doi); 2451 DB_DNODE_EXIT(db); 2452 } 2453 2454 /* 2455 * Faster still when you only care about the size. 2456 */ 2457 void 2458 dmu_object_size_from_db(dmu_buf_t *db_fake, uint32_t *blksize, 2459 u_longlong_t *nblk512) 2460 { 2461 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake; 2462 dnode_t *dn; 2463 2464 DB_DNODE_ENTER(db); 2465 dn = DB_DNODE(db); 2466 2467 *blksize = dn->dn_datablksz; 2468 /* add in number of slots used for the dnode itself */ 2469 *nblk512 = ((DN_USED_BYTES(dn->dn_phys) + SPA_MINBLOCKSIZE/2) >> 2470 SPA_MINBLOCKSHIFT) + dn->dn_num_slots; 2471 DB_DNODE_EXIT(db); 2472 } 2473 2474 void 2475 dmu_object_dnsize_from_db(dmu_buf_t *db_fake, int *dnsize) 2476 { 2477 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake; 2478 dnode_t *dn; 2479 2480 DB_DNODE_ENTER(db); 2481 dn = DB_DNODE(db); 2482 *dnsize = dn->dn_num_slots << DNODE_SHIFT; 2483 DB_DNODE_EXIT(db); 2484 } 2485 2486 void 2487 byteswap_uint64_array(void *vbuf, size_t size) 2488 { 2489 uint64_t *buf = vbuf; 2490 size_t count = size >> 3; 2491 int i; 2492 2493 ASSERT((size & 7) == 0); 2494 2495 for (i = 0; i < count; i++) 2496 buf[i] = BSWAP_64(buf[i]); 2497 } 2498 2499 void 2500 byteswap_uint32_array(void *vbuf, size_t size) 2501 { 2502 uint32_t *buf = vbuf; 2503 size_t count = size >> 2; 2504 int i; 2505 2506 ASSERT((size & 3) == 0); 2507 2508 for (i = 0; i < count; i++) 2509 buf[i] = BSWAP_32(buf[i]); 2510 } 2511 2512 void 2513 byteswap_uint16_array(void *vbuf, size_t size) 2514 { 2515 uint16_t *buf = vbuf; 2516 size_t count = size >> 1; 2517 int i; 2518 2519 ASSERT((size & 1) == 0); 2520 2521 for (i = 0; i < count; i++) 2522 buf[i] = BSWAP_16(buf[i]); 2523 } 2524 2525 void 2526 byteswap_uint8_array(void *vbuf, size_t size) 2527 { 2528 (void) vbuf, (void) size; 2529 } 2530 2531 void 2532 dmu_init(void) 2533 { 2534 abd_init(); 2535 zfs_dbgmsg_init(); 2536 sa_cache_init(); 2537 dmu_objset_init(); 2538 dnode_init(); 2539 zfetch_init(); 2540 dmu_tx_init(); 2541 l2arc_init(); 2542 arc_init(); 2543 dbuf_init(); 2544 } 2545 2546 void 2547 dmu_fini(void) 2548 { 2549 arc_fini(); /* arc depends on l2arc, so arc must go first */ 2550 l2arc_fini(); 2551 dmu_tx_fini(); 2552 zfetch_fini(); 2553 dbuf_fini(); 2554 dnode_fini(); 2555 dmu_objset_fini(); 2556 sa_cache_fini(); 2557 zfs_dbgmsg_fini(); 2558 abd_fini(); 2559 } 2560 2561 EXPORT_SYMBOL(dmu_bonus_hold); 2562 EXPORT_SYMBOL(dmu_bonus_hold_by_dnode); 2563 EXPORT_SYMBOL(dmu_buf_hold_array_by_bonus); 2564 EXPORT_SYMBOL(dmu_buf_rele_array); 2565 EXPORT_SYMBOL(dmu_prefetch); 2566 EXPORT_SYMBOL(dmu_free_range); 2567 EXPORT_SYMBOL(dmu_free_long_range); 2568 EXPORT_SYMBOL(dmu_free_long_object); 2569 EXPORT_SYMBOL(dmu_read); 2570 EXPORT_SYMBOL(dmu_read_by_dnode); 2571 EXPORT_SYMBOL(dmu_write); 2572 EXPORT_SYMBOL(dmu_write_by_dnode); 2573 EXPORT_SYMBOL(dmu_prealloc); 2574 EXPORT_SYMBOL(dmu_object_info); 2575 EXPORT_SYMBOL(dmu_object_info_from_dnode); 2576 EXPORT_SYMBOL(dmu_object_info_from_db); 2577 EXPORT_SYMBOL(dmu_object_size_from_db); 2578 EXPORT_SYMBOL(dmu_object_dnsize_from_db); 2579 EXPORT_SYMBOL(dmu_object_set_nlevels); 2580 EXPORT_SYMBOL(dmu_object_set_blocksize); 2581 EXPORT_SYMBOL(dmu_object_set_maxblkid); 2582 EXPORT_SYMBOL(dmu_object_set_checksum); 2583 EXPORT_SYMBOL(dmu_object_set_compress); 2584 EXPORT_SYMBOL(dmu_offset_next); 2585 EXPORT_SYMBOL(dmu_write_policy); 2586 EXPORT_SYMBOL(dmu_sync); 2587 EXPORT_SYMBOL(dmu_request_arcbuf); 2588 EXPORT_SYMBOL(dmu_return_arcbuf); 2589 EXPORT_SYMBOL(dmu_assign_arcbuf_by_dnode); 2590 EXPORT_SYMBOL(dmu_assign_arcbuf_by_dbuf); 2591 EXPORT_SYMBOL(dmu_buf_hold); 2592 EXPORT_SYMBOL(dmu_ot); 2593 2594 ZFS_MODULE_PARAM(zfs, zfs_, nopwrite_enabled, INT, ZMOD_RW, 2595 "Enable NOP writes"); 2596 2597 ZFS_MODULE_PARAM(zfs, zfs_, per_txg_dirty_frees_percent, UINT, ZMOD_RW, 2598 "Percentage of dirtied blocks from frees in one TXG"); 2599 2600 ZFS_MODULE_PARAM(zfs, zfs_, dmu_offset_next_sync, INT, ZMOD_RW, 2601 "Enable forcing txg sync to find holes"); 2602 2603 /* CSTYLED */ 2604 ZFS_MODULE_PARAM(zfs, , dmu_prefetch_max, UINT, ZMOD_RW, 2605 "Limit one prefetch call to this size"); 2606