dmu.c revision 323748
1/* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21/* 22 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. 23 * Copyright (c) 2011, 2017 by Delphix. All rights reserved. 24 */ 25/* Copyright (c) 2013 by Saso Kiselkov. All rights reserved. */ 26/* Copyright (c) 2013, Joyent, Inc. All rights reserved. */ 27/* Copyright (c) 2014, Nexenta Systems, Inc. All rights reserved. */ 28 29#include <sys/dmu.h> 30#include <sys/dmu_impl.h> 31#include <sys/dmu_tx.h> 32#include <sys/dbuf.h> 33#include <sys/dnode.h> 34#include <sys/zfs_context.h> 35#include <sys/dmu_objset.h> 36#include <sys/dmu_traverse.h> 37#include <sys/dsl_dataset.h> 38#include <sys/dsl_dir.h> 39#include <sys/dsl_pool.h> 40#include <sys/dsl_synctask.h> 41#include <sys/dsl_prop.h> 42#include <sys/dmu_zfetch.h> 43#include <sys/zfs_ioctl.h> 44#include <sys/zap.h> 45#include <sys/zio_checksum.h> 46#include <sys/zio_compress.h> 47#include <sys/sa.h> 48#include <sys/zfeature.h> 49#include <sys/abd.h> 50#ifdef _KERNEL 51#include <sys/racct.h> 52#include <sys/vm.h> 53#include <sys/zfs_znode.h> 54#endif 55 56/* 57 * Enable/disable nopwrite feature. 58 */ 59int zfs_nopwrite_enabled = 1; 60SYSCTL_DECL(_vfs_zfs); 61SYSCTL_INT(_vfs_zfs, OID_AUTO, nopwrite_enabled, CTLFLAG_RDTUN, 62 &zfs_nopwrite_enabled, 0, "Enable nopwrite feature"); 63 64/* 65 * Tunable to control percentage of dirtied blocks from frees in one TXG. 66 * After this threshold is crossed, additional dirty blocks from frees 67 * wait until the next TXG. 68 * A value of zero will disable this throttle. 69 */ 70uint32_t zfs_per_txg_dirty_frees_percent = 30; 71SYSCTL_INT(_vfs_zfs, OID_AUTO, per_txg_dirty_frees_percent, CTLFLAG_RWTUN, 72 &zfs_per_txg_dirty_frees_percent, 0, "Percentage of dirtied blocks from frees in one txg"); 73 74const dmu_object_type_info_t dmu_ot[DMU_OT_NUMTYPES] = { 75 { DMU_BSWAP_UINT8, TRUE, "unallocated" }, 76 { DMU_BSWAP_ZAP, TRUE, "object directory" }, 77 { DMU_BSWAP_UINT64, TRUE, "object array" }, 78 { DMU_BSWAP_UINT8, TRUE, "packed nvlist" }, 79 { DMU_BSWAP_UINT64, TRUE, "packed nvlist size" }, 80 { DMU_BSWAP_UINT64, TRUE, "bpobj" }, 81 { DMU_BSWAP_UINT64, TRUE, "bpobj header" }, 82 { DMU_BSWAP_UINT64, TRUE, "SPA space map header" }, 83 { DMU_BSWAP_UINT64, TRUE, "SPA space map" }, 84 { DMU_BSWAP_UINT64, TRUE, "ZIL intent log" }, 85 { DMU_BSWAP_DNODE, TRUE, "DMU dnode" }, 86 { DMU_BSWAP_OBJSET, TRUE, "DMU objset" }, 87 { DMU_BSWAP_UINT64, TRUE, "DSL directory" }, 88 { DMU_BSWAP_ZAP, TRUE, "DSL directory child map"}, 89 { DMU_BSWAP_ZAP, TRUE, "DSL dataset snap map" }, 90 { DMU_BSWAP_ZAP, TRUE, "DSL props" }, 91 { DMU_BSWAP_UINT64, TRUE, "DSL dataset" }, 92 { DMU_BSWAP_ZNODE, TRUE, "ZFS znode" }, 93 { DMU_BSWAP_OLDACL, TRUE, "ZFS V0 ACL" }, 94 { DMU_BSWAP_UINT8, FALSE, "ZFS plain file" }, 95 { DMU_BSWAP_ZAP, TRUE, "ZFS directory" }, 96 { DMU_BSWAP_ZAP, TRUE, "ZFS master node" }, 97 { DMU_BSWAP_ZAP, TRUE, "ZFS delete queue" }, 98 { DMU_BSWAP_UINT8, FALSE, "zvol object" }, 99 { DMU_BSWAP_ZAP, TRUE, "zvol prop" }, 100 { DMU_BSWAP_UINT8, FALSE, "other uint8[]" }, 101 { DMU_BSWAP_UINT64, FALSE, "other uint64[]" }, 102 { DMU_BSWAP_ZAP, TRUE, "other ZAP" }, 103 { DMU_BSWAP_ZAP, TRUE, "persistent error log" }, 104 { DMU_BSWAP_UINT8, TRUE, "SPA history" }, 105 { DMU_BSWAP_UINT64, TRUE, "SPA history offsets" }, 106 { DMU_BSWAP_ZAP, TRUE, "Pool properties" }, 107 { DMU_BSWAP_ZAP, TRUE, "DSL permissions" }, 108 { DMU_BSWAP_ACL, TRUE, "ZFS ACL" }, 109 { DMU_BSWAP_UINT8, TRUE, "ZFS SYSACL" }, 110 { DMU_BSWAP_UINT8, TRUE, "FUID table" }, 111 { DMU_BSWAP_UINT64, TRUE, "FUID table size" }, 112 { DMU_BSWAP_ZAP, TRUE, "DSL dataset next clones"}, 113 { DMU_BSWAP_ZAP, TRUE, "scan work queue" }, 114 { DMU_BSWAP_ZAP, TRUE, "ZFS user/group used" }, 115 { DMU_BSWAP_ZAP, TRUE, "ZFS user/group quota" }, 116 { DMU_BSWAP_ZAP, TRUE, "snapshot refcount tags"}, 117 { DMU_BSWAP_ZAP, TRUE, "DDT ZAP algorithm" }, 118 { DMU_BSWAP_ZAP, TRUE, "DDT statistics" }, 119 { DMU_BSWAP_UINT8, TRUE, "System attributes" }, 120 { DMU_BSWAP_ZAP, TRUE, "SA master node" }, 121 { DMU_BSWAP_ZAP, TRUE, "SA attr registration" }, 122 { DMU_BSWAP_ZAP, TRUE, "SA attr layouts" }, 123 { DMU_BSWAP_ZAP, TRUE, "scan translations" }, 124 { DMU_BSWAP_UINT8, FALSE, "deduplicated block" }, 125 { DMU_BSWAP_ZAP, TRUE, "DSL deadlist map" }, 126 { DMU_BSWAP_UINT64, TRUE, "DSL deadlist map hdr" }, 127 { DMU_BSWAP_ZAP, TRUE, "DSL dir clones" }, 128 { DMU_BSWAP_UINT64, TRUE, "bpobj subobj" } 129}; 130 131const dmu_object_byteswap_info_t dmu_ot_byteswap[DMU_BSWAP_NUMFUNCS] = { 132 { byteswap_uint8_array, "uint8" }, 133 { byteswap_uint16_array, "uint16" }, 134 { byteswap_uint32_array, "uint32" }, 135 { byteswap_uint64_array, "uint64" }, 136 { zap_byteswap, "zap" }, 137 { dnode_buf_byteswap, "dnode" }, 138 { dmu_objset_byteswap, "objset" }, 139 { zfs_znode_byteswap, "znode" }, 140 { zfs_oldacl_byteswap, "oldacl" }, 141 { zfs_acl_byteswap, "acl" } 142}; 143 144int 145dmu_buf_hold_noread_by_dnode(dnode_t *dn, uint64_t offset, 146 void *tag, dmu_buf_t **dbp) 147{ 148 uint64_t blkid; 149 dmu_buf_impl_t *db; 150 151 blkid = dbuf_whichblock(dn, 0, offset); 152 rw_enter(&dn->dn_struct_rwlock, RW_READER); 153 db = dbuf_hold(dn, blkid, tag); 154 rw_exit(&dn->dn_struct_rwlock); 155 156 if (db == NULL) { 157 *dbp = NULL; 158 return (SET_ERROR(EIO)); 159 } 160 161 *dbp = &db->db; 162 return (0); 163} 164int 165dmu_buf_hold_noread(objset_t *os, uint64_t object, uint64_t offset, 166 void *tag, dmu_buf_t **dbp) 167{ 168 dnode_t *dn; 169 uint64_t blkid; 170 dmu_buf_impl_t *db; 171 int err; 172 173 err = dnode_hold(os, object, FTAG, &dn); 174 if (err) 175 return (err); 176 blkid = dbuf_whichblock(dn, 0, offset); 177 rw_enter(&dn->dn_struct_rwlock, RW_READER); 178 db = dbuf_hold(dn, blkid, tag); 179 rw_exit(&dn->dn_struct_rwlock); 180 dnode_rele(dn, FTAG); 181 182 if (db == NULL) { 183 *dbp = NULL; 184 return (SET_ERROR(EIO)); 185 } 186 187 *dbp = &db->db; 188 return (err); 189} 190 191int 192dmu_buf_hold_by_dnode(dnode_t *dn, uint64_t offset, 193 void *tag, dmu_buf_t **dbp, int flags) 194{ 195 int err; 196 int db_flags = DB_RF_CANFAIL; 197 198 if (flags & DMU_READ_NO_PREFETCH) 199 db_flags |= DB_RF_NOPREFETCH; 200 201 err = dmu_buf_hold_noread_by_dnode(dn, offset, tag, dbp); 202 if (err == 0) { 203 dmu_buf_impl_t *db = (dmu_buf_impl_t *)(*dbp); 204 err = dbuf_read(db, NULL, db_flags); 205 if (err != 0) { 206 dbuf_rele(db, tag); 207 *dbp = NULL; 208 } 209 } 210 211 return (err); 212} 213 214int 215dmu_buf_hold(objset_t *os, uint64_t object, uint64_t offset, 216 void *tag, dmu_buf_t **dbp, int flags) 217{ 218 int err; 219 int db_flags = DB_RF_CANFAIL; 220 221 if (flags & DMU_READ_NO_PREFETCH) 222 db_flags |= DB_RF_NOPREFETCH; 223 224 err = dmu_buf_hold_noread(os, object, offset, tag, dbp); 225 if (err == 0) { 226 dmu_buf_impl_t *db = (dmu_buf_impl_t *)(*dbp); 227 err = dbuf_read(db, NULL, db_flags); 228 if (err != 0) { 229 dbuf_rele(db, tag); 230 *dbp = NULL; 231 } 232 } 233 234 return (err); 235} 236 237int 238dmu_bonus_max(void) 239{ 240 return (DN_MAX_BONUSLEN); 241} 242 243int 244dmu_set_bonus(dmu_buf_t *db_fake, int newsize, dmu_tx_t *tx) 245{ 246 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake; 247 dnode_t *dn; 248 int error; 249 250 DB_DNODE_ENTER(db); 251 dn = DB_DNODE(db); 252 253 if (dn->dn_bonus != db) { 254 error = SET_ERROR(EINVAL); 255 } else if (newsize < 0 || newsize > db_fake->db_size) { 256 error = SET_ERROR(EINVAL); 257 } else { 258 dnode_setbonuslen(dn, newsize, tx); 259 error = 0; 260 } 261 262 DB_DNODE_EXIT(db); 263 return (error); 264} 265 266int 267dmu_set_bonustype(dmu_buf_t *db_fake, dmu_object_type_t type, dmu_tx_t *tx) 268{ 269 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake; 270 dnode_t *dn; 271 int error; 272 273 DB_DNODE_ENTER(db); 274 dn = DB_DNODE(db); 275 276 if (!DMU_OT_IS_VALID(type)) { 277 error = SET_ERROR(EINVAL); 278 } else if (dn->dn_bonus != db) { 279 error = SET_ERROR(EINVAL); 280 } else { 281 dnode_setbonus_type(dn, type, tx); 282 error = 0; 283 } 284 285 DB_DNODE_EXIT(db); 286 return (error); 287} 288 289dmu_object_type_t 290dmu_get_bonustype(dmu_buf_t *db_fake) 291{ 292 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake; 293 dnode_t *dn; 294 dmu_object_type_t type; 295 296 DB_DNODE_ENTER(db); 297 dn = DB_DNODE(db); 298 type = dn->dn_bonustype; 299 DB_DNODE_EXIT(db); 300 301 return (type); 302} 303 304int 305dmu_rm_spill(objset_t *os, uint64_t object, dmu_tx_t *tx) 306{ 307 dnode_t *dn; 308 int error; 309 310 error = dnode_hold(os, object, FTAG, &dn); 311 dbuf_rm_spill(dn, tx); 312 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 313 dnode_rm_spill(dn, tx); 314 rw_exit(&dn->dn_struct_rwlock); 315 dnode_rele(dn, FTAG); 316 return (error); 317} 318 319/* 320 * returns ENOENT, EIO, or 0. 321 */ 322int 323dmu_bonus_hold(objset_t *os, uint64_t object, void *tag, dmu_buf_t **dbp) 324{ 325 dnode_t *dn; 326 dmu_buf_impl_t *db; 327 int error; 328 329 error = dnode_hold(os, object, FTAG, &dn); 330 if (error) 331 return (error); 332 333 rw_enter(&dn->dn_struct_rwlock, RW_READER); 334 if (dn->dn_bonus == NULL) { 335 rw_exit(&dn->dn_struct_rwlock); 336 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 337 if (dn->dn_bonus == NULL) 338 dbuf_create_bonus(dn); 339 } 340 db = dn->dn_bonus; 341 342 /* as long as the bonus buf is held, the dnode will be held */ 343 if (refcount_add(&db->db_holds, tag) == 1) { 344 VERIFY(dnode_add_ref(dn, db)); 345 atomic_inc_32(&dn->dn_dbufs_count); 346 } 347 348 /* 349 * Wait to drop dn_struct_rwlock until after adding the bonus dbuf's 350 * hold and incrementing the dbuf count to ensure that dnode_move() sees 351 * a dnode hold for every dbuf. 352 */ 353 rw_exit(&dn->dn_struct_rwlock); 354 355 dnode_rele(dn, FTAG); 356 357 VERIFY(0 == dbuf_read(db, NULL, DB_RF_MUST_SUCCEED | DB_RF_NOPREFETCH)); 358 359 *dbp = &db->db; 360 return (0); 361} 362 363/* 364 * returns ENOENT, EIO, or 0. 365 * 366 * This interface will allocate a blank spill dbuf when a spill blk 367 * doesn't already exist on the dnode. 368 * 369 * if you only want to find an already existing spill db, then 370 * dmu_spill_hold_existing() should be used. 371 */ 372int 373dmu_spill_hold_by_dnode(dnode_t *dn, uint32_t flags, void *tag, dmu_buf_t **dbp) 374{ 375 dmu_buf_impl_t *db = NULL; 376 int err; 377 378 if ((flags & DB_RF_HAVESTRUCT) == 0) 379 rw_enter(&dn->dn_struct_rwlock, RW_READER); 380 381 db = dbuf_hold(dn, DMU_SPILL_BLKID, tag); 382 383 if ((flags & DB_RF_HAVESTRUCT) == 0) 384 rw_exit(&dn->dn_struct_rwlock); 385 386 ASSERT(db != NULL); 387 err = dbuf_read(db, NULL, flags); 388 if (err == 0) 389 *dbp = &db->db; 390 else 391 dbuf_rele(db, tag); 392 return (err); 393} 394 395int 396dmu_spill_hold_existing(dmu_buf_t *bonus, void *tag, dmu_buf_t **dbp) 397{ 398 dmu_buf_impl_t *db = (dmu_buf_impl_t *)bonus; 399 dnode_t *dn; 400 int err; 401 402 DB_DNODE_ENTER(db); 403 dn = DB_DNODE(db); 404 405 if (spa_version(dn->dn_objset->os_spa) < SPA_VERSION_SA) { 406 err = SET_ERROR(EINVAL); 407 } else { 408 rw_enter(&dn->dn_struct_rwlock, RW_READER); 409 410 if (!dn->dn_have_spill) { 411 err = SET_ERROR(ENOENT); 412 } else { 413 err = dmu_spill_hold_by_dnode(dn, 414 DB_RF_HAVESTRUCT | DB_RF_CANFAIL, tag, dbp); 415 } 416 417 rw_exit(&dn->dn_struct_rwlock); 418 } 419 420 DB_DNODE_EXIT(db); 421 return (err); 422} 423 424int 425dmu_spill_hold_by_bonus(dmu_buf_t *bonus, void *tag, dmu_buf_t **dbp) 426{ 427 dmu_buf_impl_t *db = (dmu_buf_impl_t *)bonus; 428 dnode_t *dn; 429 int err; 430 431 DB_DNODE_ENTER(db); 432 dn = DB_DNODE(db); 433 err = dmu_spill_hold_by_dnode(dn, DB_RF_CANFAIL, tag, dbp); 434 DB_DNODE_EXIT(db); 435 436 return (err); 437} 438 439/* 440 * Note: longer-term, we should modify all of the dmu_buf_*() interfaces 441 * to take a held dnode rather than <os, object> -- the lookup is wasteful, 442 * and can induce severe lock contention when writing to several files 443 * whose dnodes are in the same block. 444 */ 445static int 446dmu_buf_hold_array_by_dnode(dnode_t *dn, uint64_t offset, uint64_t length, 447 boolean_t read, void *tag, int *numbufsp, dmu_buf_t ***dbpp, uint32_t flags) 448{ 449 dmu_buf_t **dbp; 450 uint64_t blkid, nblks, i; 451 uint32_t dbuf_flags; 452 int err; 453 zio_t *zio; 454 455 ASSERT(length <= DMU_MAX_ACCESS); 456 457 /* 458 * Note: We directly notify the prefetch code of this read, so that 459 * we can tell it about the multi-block read. dbuf_read() only knows 460 * about the one block it is accessing. 461 */ 462 dbuf_flags = DB_RF_CANFAIL | DB_RF_NEVERWAIT | DB_RF_HAVESTRUCT | 463 DB_RF_NOPREFETCH; 464 465 rw_enter(&dn->dn_struct_rwlock, RW_READER); 466 if (dn->dn_datablkshift) { 467 int blkshift = dn->dn_datablkshift; 468 nblks = (P2ROUNDUP(offset + length, 1ULL << blkshift) - 469 P2ALIGN(offset, 1ULL << blkshift)) >> blkshift; 470 } else { 471 if (offset + length > dn->dn_datablksz) { 472 zfs_panic_recover("zfs: accessing past end of object " 473 "%llx/%llx (size=%u access=%llu+%llu)", 474 (longlong_t)dn->dn_objset-> 475 os_dsl_dataset->ds_object, 476 (longlong_t)dn->dn_object, dn->dn_datablksz, 477 (longlong_t)offset, (longlong_t)length); 478 rw_exit(&dn->dn_struct_rwlock); 479 return (SET_ERROR(EIO)); 480 } 481 nblks = 1; 482 } 483 dbp = kmem_zalloc(sizeof (dmu_buf_t *) * nblks, KM_SLEEP); 484 485#if defined(_KERNEL) && defined(RACCT) 486 if (racct_enable && !read) { 487 PROC_LOCK(curproc); 488 racct_add_force(curproc, RACCT_WRITEBPS, length); 489 racct_add_force(curproc, RACCT_WRITEIOPS, nblks); 490 PROC_UNLOCK(curproc); 491 } 492#endif 493 494 zio = zio_root(dn->dn_objset->os_spa, NULL, NULL, ZIO_FLAG_CANFAIL); 495 blkid = dbuf_whichblock(dn, 0, offset); 496 for (i = 0; i < nblks; i++) { 497 dmu_buf_impl_t *db = dbuf_hold(dn, blkid + i, tag); 498 if (db == NULL) { 499 rw_exit(&dn->dn_struct_rwlock); 500 dmu_buf_rele_array(dbp, nblks, tag); 501 zio_nowait(zio); 502 return (SET_ERROR(EIO)); 503 } 504 505 /* initiate async i/o */ 506 if (read) 507 (void) dbuf_read(db, zio, dbuf_flags); 508#ifdef _KERNEL 509 else 510 curthread->td_ru.ru_oublock++; 511#endif 512 dbp[i] = &db->db; 513 } 514 515 if ((flags & DMU_READ_NO_PREFETCH) == 0 && 516 DNODE_META_IS_CACHEABLE(dn) && length <= zfetch_array_rd_sz) { 517 dmu_zfetch(&dn->dn_zfetch, blkid, nblks, 518 read && DNODE_IS_CACHEABLE(dn)); 519 } 520 rw_exit(&dn->dn_struct_rwlock); 521 522 /* wait for async i/o */ 523 err = zio_wait(zio); 524 if (err) { 525 dmu_buf_rele_array(dbp, nblks, tag); 526 return (err); 527 } 528 529 /* wait for other io to complete */ 530 if (read) { 531 for (i = 0; i < nblks; i++) { 532 dmu_buf_impl_t *db = (dmu_buf_impl_t *)dbp[i]; 533 mutex_enter(&db->db_mtx); 534 while (db->db_state == DB_READ || 535 db->db_state == DB_FILL) 536 cv_wait(&db->db_changed, &db->db_mtx); 537 if (db->db_state == DB_UNCACHED) 538 err = SET_ERROR(EIO); 539 mutex_exit(&db->db_mtx); 540 if (err) { 541 dmu_buf_rele_array(dbp, nblks, tag); 542 return (err); 543 } 544 } 545 } 546 547 *numbufsp = nblks; 548 *dbpp = dbp; 549 return (0); 550} 551 552static int 553dmu_buf_hold_array(objset_t *os, uint64_t object, uint64_t offset, 554 uint64_t length, int read, void *tag, int *numbufsp, dmu_buf_t ***dbpp) 555{ 556 dnode_t *dn; 557 int err; 558 559 err = dnode_hold(os, object, FTAG, &dn); 560 if (err) 561 return (err); 562 563 err = dmu_buf_hold_array_by_dnode(dn, offset, length, read, tag, 564 numbufsp, dbpp, DMU_READ_PREFETCH); 565 566 dnode_rele(dn, FTAG); 567 568 return (err); 569} 570 571int 572dmu_buf_hold_array_by_bonus(dmu_buf_t *db_fake, uint64_t offset, 573 uint64_t length, boolean_t read, void *tag, int *numbufsp, 574 dmu_buf_t ***dbpp) 575{ 576 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake; 577 dnode_t *dn; 578 int err; 579 580 DB_DNODE_ENTER(db); 581 dn = DB_DNODE(db); 582 err = dmu_buf_hold_array_by_dnode(dn, offset, length, read, tag, 583 numbufsp, dbpp, DMU_READ_PREFETCH); 584 DB_DNODE_EXIT(db); 585 586 return (err); 587} 588 589void 590dmu_buf_rele_array(dmu_buf_t **dbp_fake, int numbufs, void *tag) 591{ 592 int i; 593 dmu_buf_impl_t **dbp = (dmu_buf_impl_t **)dbp_fake; 594 595 if (numbufs == 0) 596 return; 597 598 for (i = 0; i < numbufs; i++) { 599 if (dbp[i]) 600 dbuf_rele(dbp[i], tag); 601 } 602 603 kmem_free(dbp, sizeof (dmu_buf_t *) * numbufs); 604} 605 606/* 607 * Issue prefetch i/os for the given blocks. If level is greater than 0, the 608 * indirect blocks prefeteched will be those that point to the blocks containing 609 * the data starting at offset, and continuing to offset + len. 610 * 611 * Note that if the indirect blocks above the blocks being prefetched are not in 612 * cache, they will be asychronously read in. 613 */ 614void 615dmu_prefetch(objset_t *os, uint64_t object, int64_t level, uint64_t offset, 616 uint64_t len, zio_priority_t pri) 617{ 618 dnode_t *dn; 619 uint64_t blkid; 620 int nblks, err; 621 622 if (len == 0) { /* they're interested in the bonus buffer */ 623 dn = DMU_META_DNODE(os); 624 625 if (object == 0 || object >= DN_MAX_OBJECT) 626 return; 627 628 rw_enter(&dn->dn_struct_rwlock, RW_READER); 629 blkid = dbuf_whichblock(dn, level, 630 object * sizeof (dnode_phys_t)); 631 dbuf_prefetch(dn, level, blkid, pri, 0); 632 rw_exit(&dn->dn_struct_rwlock); 633 return; 634 } 635 636 /* 637 * XXX - Note, if the dnode for the requested object is not 638 * already cached, we will do a *synchronous* read in the 639 * dnode_hold() call. The same is true for any indirects. 640 */ 641 err = dnode_hold(os, object, FTAG, &dn); 642 if (err != 0) 643 return; 644 645 rw_enter(&dn->dn_struct_rwlock, RW_READER); 646 /* 647 * offset + len - 1 is the last byte we want to prefetch for, and offset 648 * is the first. Then dbuf_whichblk(dn, level, off + len - 1) is the 649 * last block we want to prefetch, and dbuf_whichblock(dn, level, 650 * offset) is the first. Then the number we need to prefetch is the 651 * last - first + 1. 652 */ 653 if (level > 0 || dn->dn_datablkshift != 0) { 654 nblks = dbuf_whichblock(dn, level, offset + len - 1) - 655 dbuf_whichblock(dn, level, offset) + 1; 656 } else { 657 nblks = (offset < dn->dn_datablksz); 658 } 659 660 if (nblks != 0) { 661 blkid = dbuf_whichblock(dn, level, offset); 662 for (int i = 0; i < nblks; i++) 663 dbuf_prefetch(dn, level, blkid + i, pri, 0); 664 } 665 666 rw_exit(&dn->dn_struct_rwlock); 667 668 dnode_rele(dn, FTAG); 669} 670 671/* 672 * Get the next "chunk" of file data to free. We traverse the file from 673 * the end so that the file gets shorter over time (if we crashes in the 674 * middle, this will leave us in a better state). We find allocated file 675 * data by simply searching the allocated level 1 indirects. 676 * 677 * On input, *start should be the first offset that does not need to be 678 * freed (e.g. "offset + length"). On return, *start will be the first 679 * offset that should be freed. 680 */ 681static int 682get_next_chunk(dnode_t *dn, uint64_t *start, uint64_t minimum) 683{ 684 uint64_t maxblks = DMU_MAX_ACCESS >> (dn->dn_indblkshift + 1); 685 /* bytes of data covered by a level-1 indirect block */ 686 uint64_t iblkrange = 687 dn->dn_datablksz * EPB(dn->dn_indblkshift, SPA_BLKPTRSHIFT); 688 689 ASSERT3U(minimum, <=, *start); 690 691 if (*start - minimum <= iblkrange * maxblks) { 692 *start = minimum; 693 return (0); 694 } 695 ASSERT(ISP2(iblkrange)); 696 697 for (uint64_t blks = 0; *start > minimum && blks < maxblks; blks++) { 698 int err; 699 700 /* 701 * dnode_next_offset(BACKWARDS) will find an allocated L1 702 * indirect block at or before the input offset. We must 703 * decrement *start so that it is at the end of the region 704 * to search. 705 */ 706 (*start)--; 707 err = dnode_next_offset(dn, 708 DNODE_FIND_BACKWARDS, start, 2, 1, 0); 709 710 /* if there are no indirect blocks before start, we are done */ 711 if (err == ESRCH) { 712 *start = minimum; 713 break; 714 } else if (err != 0) { 715 return (err); 716 } 717 718 /* set start to the beginning of this L1 indirect */ 719 *start = P2ALIGN(*start, iblkrange); 720 } 721 if (*start < minimum) 722 *start = minimum; 723 return (0); 724} 725 726static int 727dmu_free_long_range_impl(objset_t *os, dnode_t *dn, uint64_t offset, 728 uint64_t length) 729{ 730 uint64_t object_size = (dn->dn_maxblkid + 1) * dn->dn_datablksz; 731 int err; 732 uint64_t dirty_frees_threshold; 733 dsl_pool_t *dp = dmu_objset_pool(os); 734 735 if (offset >= object_size) 736 return (0); 737 738 if (zfs_per_txg_dirty_frees_percent <= 100) 739 dirty_frees_threshold = 740 zfs_per_txg_dirty_frees_percent * zfs_dirty_data_max / 100; 741 else 742 dirty_frees_threshold = zfs_dirty_data_max / 4; 743 744 if (length == DMU_OBJECT_END || offset + length > object_size) 745 length = object_size - offset; 746 747 while (length != 0) { 748 uint64_t chunk_end, chunk_begin, chunk_len; 749 uint64_t long_free_dirty_all_txgs = 0; 750 dmu_tx_t *tx; 751 752 chunk_end = chunk_begin = offset + length; 753 754 /* move chunk_begin backwards to the beginning of this chunk */ 755 err = get_next_chunk(dn, &chunk_begin, offset); 756 if (err) 757 return (err); 758 ASSERT3U(chunk_begin, >=, offset); 759 ASSERT3U(chunk_begin, <=, chunk_end); 760 761 chunk_len = chunk_end - chunk_begin; 762 763 mutex_enter(&dp->dp_lock); 764 for (int t = 0; t < TXG_SIZE; t++) { 765 long_free_dirty_all_txgs += 766 dp->dp_long_free_dirty_pertxg[t]; 767 } 768 mutex_exit(&dp->dp_lock); 769 770 /* 771 * To avoid filling up a TXG with just frees wait for 772 * the next TXG to open before freeing more chunks if 773 * we have reached the threshold of frees 774 */ 775 if (dirty_frees_threshold != 0 && 776 long_free_dirty_all_txgs >= dirty_frees_threshold) { 777 txg_wait_open(dp, 0); 778 continue; 779 } 780 781 tx = dmu_tx_create(os); 782 dmu_tx_hold_free(tx, dn->dn_object, chunk_begin, chunk_len); 783 784 /* 785 * Mark this transaction as typically resulting in a net 786 * reduction in space used. 787 */ 788 dmu_tx_mark_netfree(tx); 789 err = dmu_tx_assign(tx, TXG_WAIT); 790 if (err) { 791 dmu_tx_abort(tx); 792 return (err); 793 } 794 795 mutex_enter(&dp->dp_lock); 796 dp->dp_long_free_dirty_pertxg[dmu_tx_get_txg(tx) & TXG_MASK] += 797 chunk_len; 798 mutex_exit(&dp->dp_lock); 799 DTRACE_PROBE3(free__long__range, 800 uint64_t, long_free_dirty_all_txgs, uint64_t, chunk_len, 801 uint64_t, dmu_tx_get_txg(tx)); 802 dnode_free_range(dn, chunk_begin, chunk_len, tx); 803 dmu_tx_commit(tx); 804 805 length -= chunk_len; 806 } 807 return (0); 808} 809 810int 811dmu_free_long_range(objset_t *os, uint64_t object, 812 uint64_t offset, uint64_t length) 813{ 814 dnode_t *dn; 815 int err; 816 817 err = dnode_hold(os, object, FTAG, &dn); 818 if (err != 0) 819 return (err); 820 err = dmu_free_long_range_impl(os, dn, offset, length); 821 822 /* 823 * It is important to zero out the maxblkid when freeing the entire 824 * file, so that (a) subsequent calls to dmu_free_long_range_impl() 825 * will take the fast path, and (b) dnode_reallocate() can verify 826 * that the entire file has been freed. 827 */ 828 if (err == 0 && offset == 0 && length == DMU_OBJECT_END) 829 dn->dn_maxblkid = 0; 830 831 dnode_rele(dn, FTAG); 832 return (err); 833} 834 835int 836dmu_free_long_object(objset_t *os, uint64_t object) 837{ 838 dmu_tx_t *tx; 839 int err; 840 841 err = dmu_free_long_range(os, object, 0, DMU_OBJECT_END); 842 if (err != 0) 843 return (err); 844 845 tx = dmu_tx_create(os); 846 dmu_tx_hold_bonus(tx, object); 847 dmu_tx_hold_free(tx, object, 0, DMU_OBJECT_END); 848 dmu_tx_mark_netfree(tx); 849 err = dmu_tx_assign(tx, TXG_WAIT); 850 if (err == 0) { 851 err = dmu_object_free(os, object, tx); 852 dmu_tx_commit(tx); 853 } else { 854 dmu_tx_abort(tx); 855 } 856 857 return (err); 858} 859 860int 861dmu_free_range(objset_t *os, uint64_t object, uint64_t offset, 862 uint64_t size, dmu_tx_t *tx) 863{ 864 dnode_t *dn; 865 int err = dnode_hold(os, object, FTAG, &dn); 866 if (err) 867 return (err); 868 ASSERT(offset < UINT64_MAX); 869 ASSERT(size == -1ULL || size <= UINT64_MAX - offset); 870 dnode_free_range(dn, offset, size, tx); 871 dnode_rele(dn, FTAG); 872 return (0); 873} 874 875static int 876dmu_read_impl(dnode_t *dn, uint64_t offset, uint64_t size, 877 void *buf, uint32_t flags) 878{ 879 dmu_buf_t **dbp; 880 int numbufs, err = 0; 881 882 /* 883 * Deal with odd block sizes, where there can't be data past the first 884 * block. If we ever do the tail block optimization, we will need to 885 * handle that here as well. 886 */ 887 if (dn->dn_maxblkid == 0) { 888 int newsz = offset > dn->dn_datablksz ? 0 : 889 MIN(size, dn->dn_datablksz - offset); 890 bzero((char *)buf + newsz, size - newsz); 891 size = newsz; 892 } 893 894 while (size > 0) { 895 uint64_t mylen = MIN(size, DMU_MAX_ACCESS / 2); 896 int i; 897 898 /* 899 * NB: we could do this block-at-a-time, but it's nice 900 * to be reading in parallel. 901 */ 902 err = dmu_buf_hold_array_by_dnode(dn, offset, mylen, 903 TRUE, FTAG, &numbufs, &dbp, flags); 904 if (err) 905 break; 906 907 for (i = 0; i < numbufs; i++) { 908 int tocpy; 909 int bufoff; 910 dmu_buf_t *db = dbp[i]; 911 912 ASSERT(size > 0); 913 914 bufoff = offset - db->db_offset; 915 tocpy = (int)MIN(db->db_size - bufoff, size); 916 917 bcopy((char *)db->db_data + bufoff, buf, tocpy); 918 919 offset += tocpy; 920 size -= tocpy; 921 buf = (char *)buf + tocpy; 922 } 923 dmu_buf_rele_array(dbp, numbufs, FTAG); 924 } 925 return (err); 926} 927 928int 929dmu_read(objset_t *os, uint64_t object, uint64_t offset, uint64_t size, 930 void *buf, uint32_t flags) 931{ 932 dnode_t *dn; 933 int err; 934 935 err = dnode_hold(os, object, FTAG, &dn); 936 if (err != 0) 937 return (err); 938 939 err = dmu_read_impl(dn, offset, size, buf, flags); 940 dnode_rele(dn, FTAG); 941 return (err); 942} 943 944int 945dmu_read_by_dnode(dnode_t *dn, uint64_t offset, uint64_t size, void *buf, 946 uint32_t flags) 947{ 948 return (dmu_read_impl(dn, offset, size, buf, flags)); 949} 950 951static void 952dmu_write_impl(dmu_buf_t **dbp, int numbufs, uint64_t offset, uint64_t size, 953 const void *buf, dmu_tx_t *tx) 954{ 955 int i; 956 957 for (i = 0; i < numbufs; i++) { 958 int tocpy; 959 int bufoff; 960 dmu_buf_t *db = dbp[i]; 961 962 ASSERT(size > 0); 963 964 bufoff = offset - db->db_offset; 965 tocpy = (int)MIN(db->db_size - bufoff, size); 966 967 ASSERT(i == 0 || i == numbufs-1 || tocpy == db->db_size); 968 969 if (tocpy == db->db_size) 970 dmu_buf_will_fill(db, tx); 971 else 972 dmu_buf_will_dirty(db, tx); 973 974 bcopy(buf, (char *)db->db_data + bufoff, tocpy); 975 976 if (tocpy == db->db_size) 977 dmu_buf_fill_done(db, tx); 978 979 offset += tocpy; 980 size -= tocpy; 981 buf = (char *)buf + tocpy; 982 } 983} 984 985void 986dmu_write(objset_t *os, uint64_t object, uint64_t offset, uint64_t size, 987 const void *buf, dmu_tx_t *tx) 988{ 989 dmu_buf_t **dbp; 990 int numbufs; 991 992 if (size == 0) 993 return; 994 995 VERIFY0(dmu_buf_hold_array(os, object, offset, size, 996 FALSE, FTAG, &numbufs, &dbp)); 997 dmu_write_impl(dbp, numbufs, offset, size, buf, tx); 998 dmu_buf_rele_array(dbp, numbufs, FTAG); 999} 1000 1001void 1002dmu_write_by_dnode(dnode_t *dn, uint64_t offset, uint64_t size, 1003 const void *buf, dmu_tx_t *tx) 1004{ 1005 dmu_buf_t **dbp; 1006 int numbufs; 1007 1008 if (size == 0) 1009 return; 1010 1011 VERIFY0(dmu_buf_hold_array_by_dnode(dn, offset, size, 1012 FALSE, FTAG, &numbufs, &dbp, DMU_READ_PREFETCH)); 1013 dmu_write_impl(dbp, numbufs, offset, size, buf, tx); 1014 dmu_buf_rele_array(dbp, numbufs, FTAG); 1015} 1016 1017void 1018dmu_prealloc(objset_t *os, uint64_t object, uint64_t offset, uint64_t size, 1019 dmu_tx_t *tx) 1020{ 1021 dmu_buf_t **dbp; 1022 int numbufs, i; 1023 1024 if (size == 0) 1025 return; 1026 1027 VERIFY(0 == dmu_buf_hold_array(os, object, offset, size, 1028 FALSE, FTAG, &numbufs, &dbp)); 1029 1030 for (i = 0; i < numbufs; i++) { 1031 dmu_buf_t *db = dbp[i]; 1032 1033 dmu_buf_will_not_fill(db, tx); 1034 } 1035 dmu_buf_rele_array(dbp, numbufs, FTAG); 1036} 1037 1038void 1039dmu_write_embedded(objset_t *os, uint64_t object, uint64_t offset, 1040 void *data, uint8_t etype, uint8_t comp, int uncompressed_size, 1041 int compressed_size, int byteorder, dmu_tx_t *tx) 1042{ 1043 dmu_buf_t *db; 1044 1045 ASSERT3U(etype, <, NUM_BP_EMBEDDED_TYPES); 1046 ASSERT3U(comp, <, ZIO_COMPRESS_FUNCTIONS); 1047 VERIFY0(dmu_buf_hold_noread(os, object, offset, 1048 FTAG, &db)); 1049 1050 dmu_buf_write_embedded(db, 1051 data, (bp_embedded_type_t)etype, (enum zio_compress)comp, 1052 uncompressed_size, compressed_size, byteorder, tx); 1053 1054 dmu_buf_rele(db, FTAG); 1055} 1056 1057/* 1058 * DMU support for xuio 1059 */ 1060kstat_t *xuio_ksp = NULL; 1061 1062int 1063dmu_xuio_init(xuio_t *xuio, int nblk) 1064{ 1065 dmu_xuio_t *priv; 1066 uio_t *uio = &xuio->xu_uio; 1067 1068 uio->uio_iovcnt = nblk; 1069 uio->uio_iov = kmem_zalloc(nblk * sizeof (iovec_t), KM_SLEEP); 1070 1071 priv = kmem_zalloc(sizeof (dmu_xuio_t), KM_SLEEP); 1072 priv->cnt = nblk; 1073 priv->bufs = kmem_zalloc(nblk * sizeof (arc_buf_t *), KM_SLEEP); 1074 priv->iovp = uio->uio_iov; 1075 XUIO_XUZC_PRIV(xuio) = priv; 1076 1077 if (XUIO_XUZC_RW(xuio) == UIO_READ) 1078 XUIOSTAT_INCR(xuiostat_onloan_rbuf, nblk); 1079 else 1080 XUIOSTAT_INCR(xuiostat_onloan_wbuf, nblk); 1081 1082 return (0); 1083} 1084 1085void 1086dmu_xuio_fini(xuio_t *xuio) 1087{ 1088 dmu_xuio_t *priv = XUIO_XUZC_PRIV(xuio); 1089 int nblk = priv->cnt; 1090 1091 kmem_free(priv->iovp, nblk * sizeof (iovec_t)); 1092 kmem_free(priv->bufs, nblk * sizeof (arc_buf_t *)); 1093 kmem_free(priv, sizeof (dmu_xuio_t)); 1094 1095 if (XUIO_XUZC_RW(xuio) == UIO_READ) 1096 XUIOSTAT_INCR(xuiostat_onloan_rbuf, -nblk); 1097 else 1098 XUIOSTAT_INCR(xuiostat_onloan_wbuf, -nblk); 1099} 1100 1101/* 1102 * Initialize iov[priv->next] and priv->bufs[priv->next] with { off, n, abuf } 1103 * and increase priv->next by 1. 1104 */ 1105int 1106dmu_xuio_add(xuio_t *xuio, arc_buf_t *abuf, offset_t off, size_t n) 1107{ 1108 struct iovec *iov; 1109 uio_t *uio = &xuio->xu_uio; 1110 dmu_xuio_t *priv = XUIO_XUZC_PRIV(xuio); 1111 int i = priv->next++; 1112 1113 ASSERT(i < priv->cnt); 1114 ASSERT(off + n <= arc_buf_lsize(abuf)); 1115 iov = uio->uio_iov + i; 1116 iov->iov_base = (char *)abuf->b_data + off; 1117 iov->iov_len = n; 1118 priv->bufs[i] = abuf; 1119 return (0); 1120} 1121 1122int 1123dmu_xuio_cnt(xuio_t *xuio) 1124{ 1125 dmu_xuio_t *priv = XUIO_XUZC_PRIV(xuio); 1126 return (priv->cnt); 1127} 1128 1129arc_buf_t * 1130dmu_xuio_arcbuf(xuio_t *xuio, int i) 1131{ 1132 dmu_xuio_t *priv = XUIO_XUZC_PRIV(xuio); 1133 1134 ASSERT(i < priv->cnt); 1135 return (priv->bufs[i]); 1136} 1137 1138void 1139dmu_xuio_clear(xuio_t *xuio, int i) 1140{ 1141 dmu_xuio_t *priv = XUIO_XUZC_PRIV(xuio); 1142 1143 ASSERT(i < priv->cnt); 1144 priv->bufs[i] = NULL; 1145} 1146 1147static void 1148xuio_stat_init(void) 1149{ 1150 xuio_ksp = kstat_create("zfs", 0, "xuio_stats", "misc", 1151 KSTAT_TYPE_NAMED, sizeof (xuio_stats) / sizeof (kstat_named_t), 1152 KSTAT_FLAG_VIRTUAL); 1153 if (xuio_ksp != NULL) { 1154 xuio_ksp->ks_data = &xuio_stats; 1155 kstat_install(xuio_ksp); 1156 } 1157} 1158 1159static void 1160xuio_stat_fini(void) 1161{ 1162 if (xuio_ksp != NULL) { 1163 kstat_delete(xuio_ksp); 1164 xuio_ksp = NULL; 1165 } 1166} 1167 1168void 1169xuio_stat_wbuf_copied(void) 1170{ 1171 XUIOSTAT_BUMP(xuiostat_wbuf_copied); 1172} 1173 1174void 1175xuio_stat_wbuf_nocopy(void) 1176{ 1177 XUIOSTAT_BUMP(xuiostat_wbuf_nocopy); 1178} 1179 1180#ifdef _KERNEL 1181static int 1182dmu_read_uio_dnode(dnode_t *dn, uio_t *uio, uint64_t size) 1183{ 1184 dmu_buf_t **dbp; 1185 int numbufs, i, err; 1186 xuio_t *xuio = NULL; 1187 1188 /* 1189 * NB: we could do this block-at-a-time, but it's nice 1190 * to be reading in parallel. 1191 */ 1192 err = dmu_buf_hold_array_by_dnode(dn, uio->uio_loffset, size, 1193 TRUE, FTAG, &numbufs, &dbp, 0); 1194 if (err) 1195 return (err); 1196 1197#ifdef UIO_XUIO 1198 if (uio->uio_extflg == UIO_XUIO) 1199 xuio = (xuio_t *)uio; 1200#endif 1201 1202 for (i = 0; i < numbufs; i++) { 1203 int tocpy; 1204 int bufoff; 1205 dmu_buf_t *db = dbp[i]; 1206 1207 ASSERT(size > 0); 1208 1209 bufoff = uio->uio_loffset - db->db_offset; 1210 tocpy = (int)MIN(db->db_size - bufoff, size); 1211 1212 if (xuio) { 1213 dmu_buf_impl_t *dbi = (dmu_buf_impl_t *)db; 1214 arc_buf_t *dbuf_abuf = dbi->db_buf; 1215 arc_buf_t *abuf = dbuf_loan_arcbuf(dbi); 1216 err = dmu_xuio_add(xuio, abuf, bufoff, tocpy); 1217 if (!err) { 1218 uio->uio_resid -= tocpy; 1219 uio->uio_loffset += tocpy; 1220 } 1221 1222 if (abuf == dbuf_abuf) 1223 XUIOSTAT_BUMP(xuiostat_rbuf_nocopy); 1224 else 1225 XUIOSTAT_BUMP(xuiostat_rbuf_copied); 1226 } else { 1227#ifdef illumos 1228 err = uiomove((char *)db->db_data + bufoff, tocpy, 1229 UIO_READ, uio); 1230#else 1231 err = vn_io_fault_uiomove((char *)db->db_data + bufoff, 1232 tocpy, uio); 1233#endif 1234 } 1235 if (err) 1236 break; 1237 1238 size -= tocpy; 1239 } 1240 dmu_buf_rele_array(dbp, numbufs, FTAG); 1241 1242 return (err); 1243} 1244 1245/* 1246 * Read 'size' bytes into the uio buffer. 1247 * From object zdb->db_object. 1248 * Starting at offset uio->uio_loffset. 1249 * 1250 * If the caller already has a dbuf in the target object 1251 * (e.g. its bonus buffer), this routine is faster than dmu_read_uio(), 1252 * because we don't have to find the dnode_t for the object. 1253 */ 1254int 1255dmu_read_uio_dbuf(dmu_buf_t *zdb, uio_t *uio, uint64_t size) 1256{ 1257 dmu_buf_impl_t *db = (dmu_buf_impl_t *)zdb; 1258 dnode_t *dn; 1259 int err; 1260 1261 if (size == 0) 1262 return (0); 1263 1264 DB_DNODE_ENTER(db); 1265 dn = DB_DNODE(db); 1266 err = dmu_read_uio_dnode(dn, uio, size); 1267 DB_DNODE_EXIT(db); 1268 1269 return (err); 1270} 1271 1272/* 1273 * Read 'size' bytes into the uio buffer. 1274 * From the specified object 1275 * Starting at offset uio->uio_loffset. 1276 */ 1277int 1278dmu_read_uio(objset_t *os, uint64_t object, uio_t *uio, uint64_t size) 1279{ 1280 dnode_t *dn; 1281 int err; 1282 1283 if (size == 0) 1284 return (0); 1285 1286 err = dnode_hold(os, object, FTAG, &dn); 1287 if (err) 1288 return (err); 1289 1290 err = dmu_read_uio_dnode(dn, uio, size); 1291 1292 dnode_rele(dn, FTAG); 1293 1294 return (err); 1295} 1296 1297static int 1298dmu_write_uio_dnode(dnode_t *dn, uio_t *uio, uint64_t size, dmu_tx_t *tx) 1299{ 1300 dmu_buf_t **dbp; 1301 int numbufs; 1302 int err = 0; 1303 int i; 1304 1305 err = dmu_buf_hold_array_by_dnode(dn, uio->uio_loffset, size, 1306 FALSE, FTAG, &numbufs, &dbp, DMU_READ_PREFETCH); 1307 if (err) 1308 return (err); 1309 1310 for (i = 0; i < numbufs; i++) { 1311 int tocpy; 1312 int bufoff; 1313 dmu_buf_t *db = dbp[i]; 1314 1315 ASSERT(size > 0); 1316 1317 bufoff = uio->uio_loffset - db->db_offset; 1318 tocpy = (int)MIN(db->db_size - bufoff, size); 1319 1320 ASSERT(i == 0 || i == numbufs-1 || tocpy == db->db_size); 1321 1322 if (tocpy == db->db_size) 1323 dmu_buf_will_fill(db, tx); 1324 else 1325 dmu_buf_will_dirty(db, tx); 1326 1327#ifdef illumos 1328 /* 1329 * XXX uiomove could block forever (eg. nfs-backed 1330 * pages). There needs to be a uiolockdown() function 1331 * to lock the pages in memory, so that uiomove won't 1332 * block. 1333 */ 1334 err = uiomove((char *)db->db_data + bufoff, tocpy, 1335 UIO_WRITE, uio); 1336#else 1337 err = vn_io_fault_uiomove((char *)db->db_data + bufoff, tocpy, 1338 uio); 1339#endif 1340 1341 if (tocpy == db->db_size) 1342 dmu_buf_fill_done(db, tx); 1343 1344 if (err) 1345 break; 1346 1347 size -= tocpy; 1348 } 1349 1350 dmu_buf_rele_array(dbp, numbufs, FTAG); 1351 return (err); 1352} 1353 1354/* 1355 * Write 'size' bytes from the uio buffer. 1356 * To object zdb->db_object. 1357 * Starting at offset uio->uio_loffset. 1358 * 1359 * If the caller already has a dbuf in the target object 1360 * (e.g. its bonus buffer), this routine is faster than dmu_write_uio(), 1361 * because we don't have to find the dnode_t for the object. 1362 */ 1363int 1364dmu_write_uio_dbuf(dmu_buf_t *zdb, uio_t *uio, uint64_t size, 1365 dmu_tx_t *tx) 1366{ 1367 dmu_buf_impl_t *db = (dmu_buf_impl_t *)zdb; 1368 dnode_t *dn; 1369 int err; 1370 1371 if (size == 0) 1372 return (0); 1373 1374 DB_DNODE_ENTER(db); 1375 dn = DB_DNODE(db); 1376 err = dmu_write_uio_dnode(dn, uio, size, tx); 1377 DB_DNODE_EXIT(db); 1378 1379 return (err); 1380} 1381 1382/* 1383 * Write 'size' bytes from the uio buffer. 1384 * To the specified object. 1385 * Starting at offset uio->uio_loffset. 1386 */ 1387int 1388dmu_write_uio(objset_t *os, uint64_t object, uio_t *uio, uint64_t size, 1389 dmu_tx_t *tx) 1390{ 1391 dnode_t *dn; 1392 int err; 1393 1394 if (size == 0) 1395 return (0); 1396 1397 err = dnode_hold(os, object, FTAG, &dn); 1398 if (err) 1399 return (err); 1400 1401 err = dmu_write_uio_dnode(dn, uio, size, tx); 1402 1403 dnode_rele(dn, FTAG); 1404 1405 return (err); 1406} 1407 1408#ifdef illumos 1409int 1410dmu_write_pages(objset_t *os, uint64_t object, uint64_t offset, uint64_t size, 1411 page_t *pp, dmu_tx_t *tx) 1412{ 1413 dmu_buf_t **dbp; 1414 int numbufs, i; 1415 int err; 1416 1417 if (size == 0) 1418 return (0); 1419 1420 err = dmu_buf_hold_array(os, object, offset, size, 1421 FALSE, FTAG, &numbufs, &dbp); 1422 if (err) 1423 return (err); 1424 1425 for (i = 0; i < numbufs; i++) { 1426 int tocpy, copied, thiscpy; 1427 int bufoff; 1428 dmu_buf_t *db = dbp[i]; 1429 caddr_t va; 1430 1431 ASSERT(size > 0); 1432 ASSERT3U(db->db_size, >=, PAGESIZE); 1433 1434 bufoff = offset - db->db_offset; 1435 tocpy = (int)MIN(db->db_size - bufoff, size); 1436 1437 ASSERT(i == 0 || i == numbufs-1 || tocpy == db->db_size); 1438 1439 if (tocpy == db->db_size) 1440 dmu_buf_will_fill(db, tx); 1441 else 1442 dmu_buf_will_dirty(db, tx); 1443 1444 for (copied = 0; copied < tocpy; copied += PAGESIZE) { 1445 ASSERT3U(pp->p_offset, ==, db->db_offset + bufoff); 1446 thiscpy = MIN(PAGESIZE, tocpy - copied); 1447 va = zfs_map_page(pp, S_READ); 1448 bcopy(va, (char *)db->db_data + bufoff, thiscpy); 1449 zfs_unmap_page(pp, va); 1450 pp = pp->p_next; 1451 bufoff += PAGESIZE; 1452 } 1453 1454 if (tocpy == db->db_size) 1455 dmu_buf_fill_done(db, tx); 1456 1457 offset += tocpy; 1458 size -= tocpy; 1459 } 1460 dmu_buf_rele_array(dbp, numbufs, FTAG); 1461 return (err); 1462} 1463 1464#else /* !illumos */ 1465 1466int 1467dmu_write_pages(objset_t *os, uint64_t object, uint64_t offset, uint64_t size, 1468 vm_page_t *ma, dmu_tx_t *tx) 1469{ 1470 dmu_buf_t **dbp; 1471 struct sf_buf *sf; 1472 int numbufs, i; 1473 int err; 1474 1475 if (size == 0) 1476 return (0); 1477 1478 err = dmu_buf_hold_array(os, object, offset, size, 1479 FALSE, FTAG, &numbufs, &dbp); 1480 if (err) 1481 return (err); 1482 1483 for (i = 0; i < numbufs; i++) { 1484 int tocpy, copied, thiscpy; 1485 int bufoff; 1486 dmu_buf_t *db = dbp[i]; 1487 caddr_t va; 1488 1489 ASSERT(size > 0); 1490 ASSERT3U(db->db_size, >=, PAGESIZE); 1491 1492 bufoff = offset - db->db_offset; 1493 tocpy = (int)MIN(db->db_size - bufoff, size); 1494 1495 ASSERT(i == 0 || i == numbufs-1 || tocpy == db->db_size); 1496 1497 if (tocpy == db->db_size) 1498 dmu_buf_will_fill(db, tx); 1499 else 1500 dmu_buf_will_dirty(db, tx); 1501 1502 for (copied = 0; copied < tocpy; copied += PAGESIZE) { 1503 ASSERT3U(ptoa((*ma)->pindex), ==, db->db_offset + bufoff); 1504 thiscpy = MIN(PAGESIZE, tocpy - copied); 1505 va = zfs_map_page(*ma, &sf); 1506 bcopy(va, (char *)db->db_data + bufoff, thiscpy); 1507 zfs_unmap_page(sf); 1508 ma += 1; 1509 bufoff += PAGESIZE; 1510 } 1511 1512 if (tocpy == db->db_size) 1513 dmu_buf_fill_done(db, tx); 1514 1515 offset += tocpy; 1516 size -= tocpy; 1517 } 1518 dmu_buf_rele_array(dbp, numbufs, FTAG); 1519 return (err); 1520} 1521#endif /* illumos */ 1522#endif /* _KERNEL */ 1523 1524/* 1525 * Allocate a loaned anonymous arc buffer. 1526 */ 1527arc_buf_t * 1528dmu_request_arcbuf(dmu_buf_t *handle, int size) 1529{ 1530 dmu_buf_impl_t *db = (dmu_buf_impl_t *)handle; 1531 1532 return (arc_loan_buf(db->db_objset->os_spa, B_FALSE, size)); 1533} 1534 1535/* 1536 * Free a loaned arc buffer. 1537 */ 1538void 1539dmu_return_arcbuf(arc_buf_t *buf) 1540{ 1541 arc_return_buf(buf, FTAG); 1542 arc_buf_destroy(buf, FTAG); 1543} 1544 1545/* 1546 * When possible directly assign passed loaned arc buffer to a dbuf. 1547 * If this is not possible copy the contents of passed arc buf via 1548 * dmu_write(). 1549 */ 1550void 1551dmu_assign_arcbuf(dmu_buf_t *handle, uint64_t offset, arc_buf_t *buf, 1552 dmu_tx_t *tx) 1553{ 1554 dmu_buf_impl_t *dbuf = (dmu_buf_impl_t *)handle; 1555 dnode_t *dn; 1556 dmu_buf_impl_t *db; 1557 uint32_t blksz = (uint32_t)arc_buf_lsize(buf); 1558 uint64_t blkid; 1559 1560 DB_DNODE_ENTER(dbuf); 1561 dn = DB_DNODE(dbuf); 1562 rw_enter(&dn->dn_struct_rwlock, RW_READER); 1563 blkid = dbuf_whichblock(dn, 0, offset); 1564 VERIFY((db = dbuf_hold(dn, blkid, FTAG)) != NULL); 1565 rw_exit(&dn->dn_struct_rwlock); 1566 DB_DNODE_EXIT(dbuf); 1567 1568 /* 1569 * We can only assign if the offset is aligned, the arc buf is the 1570 * same size as the dbuf, and the dbuf is not metadata. 1571 */ 1572 if (offset == db->db.db_offset && blksz == db->db.db_size) { 1573#ifdef _KERNEL 1574 curthread->td_ru.ru_oublock++; 1575#ifdef RACCT 1576 if (racct_enable) { 1577 PROC_LOCK(curproc); 1578 racct_add_force(curproc, RACCT_WRITEBPS, blksz); 1579 racct_add_force(curproc, RACCT_WRITEIOPS, 1); 1580 PROC_UNLOCK(curproc); 1581 } 1582#endif /* RACCT */ 1583#endif /* _KERNEL */ 1584 dbuf_assign_arcbuf(db, buf, tx); 1585 dbuf_rele(db, FTAG); 1586 } else { 1587 objset_t *os; 1588 uint64_t object; 1589 1590 /* compressed bufs must always be assignable to their dbuf */ 1591 ASSERT3U(arc_get_compression(buf), ==, ZIO_COMPRESS_OFF); 1592 ASSERT(!(buf->b_flags & ARC_BUF_FLAG_COMPRESSED)); 1593 1594 DB_DNODE_ENTER(dbuf); 1595 dn = DB_DNODE(dbuf); 1596 os = dn->dn_objset; 1597 object = dn->dn_object; 1598 DB_DNODE_EXIT(dbuf); 1599 1600 dbuf_rele(db, FTAG); 1601 dmu_write(os, object, offset, blksz, buf->b_data, tx); 1602 dmu_return_arcbuf(buf); 1603 XUIOSTAT_BUMP(xuiostat_wbuf_copied); 1604 } 1605} 1606 1607typedef struct { 1608 dbuf_dirty_record_t *dsa_dr; 1609 dmu_sync_cb_t *dsa_done; 1610 zgd_t *dsa_zgd; 1611 dmu_tx_t *dsa_tx; 1612} dmu_sync_arg_t; 1613 1614/* ARGSUSED */ 1615static void 1616dmu_sync_ready(zio_t *zio, arc_buf_t *buf, void *varg) 1617{ 1618 dmu_sync_arg_t *dsa = varg; 1619 dmu_buf_t *db = dsa->dsa_zgd->zgd_db; 1620 blkptr_t *bp = zio->io_bp; 1621 1622 if (zio->io_error == 0) { 1623 if (BP_IS_HOLE(bp)) { 1624 /* 1625 * A block of zeros may compress to a hole, but the 1626 * block size still needs to be known for replay. 1627 */ 1628 BP_SET_LSIZE(bp, db->db_size); 1629 } else if (!BP_IS_EMBEDDED(bp)) { 1630 ASSERT(BP_GET_LEVEL(bp) == 0); 1631 bp->blk_fill = 1; 1632 } 1633 } 1634} 1635 1636static void 1637dmu_sync_late_arrival_ready(zio_t *zio) 1638{ 1639 dmu_sync_ready(zio, NULL, zio->io_private); 1640} 1641 1642/* ARGSUSED */ 1643static void 1644dmu_sync_done(zio_t *zio, arc_buf_t *buf, void *varg) 1645{ 1646 dmu_sync_arg_t *dsa = varg; 1647 dbuf_dirty_record_t *dr = dsa->dsa_dr; 1648 dmu_buf_impl_t *db = dr->dr_dbuf; 1649 1650 mutex_enter(&db->db_mtx); 1651 ASSERT(dr->dt.dl.dr_override_state == DR_IN_DMU_SYNC); 1652 if (zio->io_error == 0) { 1653 dr->dt.dl.dr_nopwrite = !!(zio->io_flags & ZIO_FLAG_NOPWRITE); 1654 if (dr->dt.dl.dr_nopwrite) { 1655 blkptr_t *bp = zio->io_bp; 1656 blkptr_t *bp_orig = &zio->io_bp_orig; 1657 uint8_t chksum = BP_GET_CHECKSUM(bp_orig); 1658 1659 ASSERT(BP_EQUAL(bp, bp_orig)); 1660 VERIFY(BP_EQUAL(bp, db->db_blkptr)); 1661 ASSERT(zio->io_prop.zp_compress != ZIO_COMPRESS_OFF); 1662 ASSERT(zio_checksum_table[chksum].ci_flags & 1663 ZCHECKSUM_FLAG_NOPWRITE); 1664 } 1665 dr->dt.dl.dr_overridden_by = *zio->io_bp; 1666 dr->dt.dl.dr_override_state = DR_OVERRIDDEN; 1667 dr->dt.dl.dr_copies = zio->io_prop.zp_copies; 1668 1669 /* 1670 * Old style holes are filled with all zeros, whereas 1671 * new-style holes maintain their lsize, type, level, 1672 * and birth time (see zio_write_compress). While we 1673 * need to reset the BP_SET_LSIZE() call that happened 1674 * in dmu_sync_ready for old style holes, we do *not* 1675 * want to wipe out the information contained in new 1676 * style holes. Thus, only zero out the block pointer if 1677 * it's an old style hole. 1678 */ 1679 if (BP_IS_HOLE(&dr->dt.dl.dr_overridden_by) && 1680 dr->dt.dl.dr_overridden_by.blk_birth == 0) 1681 BP_ZERO(&dr->dt.dl.dr_overridden_by); 1682 } else { 1683 dr->dt.dl.dr_override_state = DR_NOT_OVERRIDDEN; 1684 } 1685 cv_broadcast(&db->db_changed); 1686 mutex_exit(&db->db_mtx); 1687 1688 dsa->dsa_done(dsa->dsa_zgd, zio->io_error); 1689 1690 kmem_free(dsa, sizeof (*dsa)); 1691} 1692 1693static void 1694dmu_sync_late_arrival_done(zio_t *zio) 1695{ 1696 blkptr_t *bp = zio->io_bp; 1697 dmu_sync_arg_t *dsa = zio->io_private; 1698 blkptr_t *bp_orig = &zio->io_bp_orig; 1699 1700 if (zio->io_error == 0 && !BP_IS_HOLE(bp)) { 1701 ASSERT(!(zio->io_flags & ZIO_FLAG_NOPWRITE)); 1702 ASSERT(BP_IS_HOLE(bp_orig) || !BP_EQUAL(bp, bp_orig)); 1703 ASSERT(zio->io_bp->blk_birth == zio->io_txg); 1704 ASSERT(zio->io_txg > spa_syncing_txg(zio->io_spa)); 1705 zio_free(zio->io_spa, zio->io_txg, zio->io_bp); 1706 } 1707 1708 dmu_tx_commit(dsa->dsa_tx); 1709 1710 dsa->dsa_done(dsa->dsa_zgd, zio->io_error); 1711 1712 abd_put(zio->io_abd); 1713 kmem_free(dsa, sizeof (*dsa)); 1714} 1715 1716static int 1717dmu_sync_late_arrival(zio_t *pio, objset_t *os, dmu_sync_cb_t *done, zgd_t *zgd, 1718 zio_prop_t *zp, zbookmark_phys_t *zb) 1719{ 1720 dmu_sync_arg_t *dsa; 1721 dmu_tx_t *tx; 1722 1723 tx = dmu_tx_create(os); 1724 dmu_tx_hold_space(tx, zgd->zgd_db->db_size); 1725 if (dmu_tx_assign(tx, TXG_WAIT) != 0) { 1726 dmu_tx_abort(tx); 1727 /* Make zl_get_data do txg_waited_synced() */ 1728 return (SET_ERROR(EIO)); 1729 } 1730 1731 dsa = kmem_alloc(sizeof (dmu_sync_arg_t), KM_SLEEP); 1732 dsa->dsa_dr = NULL; 1733 dsa->dsa_done = done; 1734 dsa->dsa_zgd = zgd; 1735 dsa->dsa_tx = tx; 1736 1737 /* 1738 * Since we are currently syncing this txg, it's nontrivial to 1739 * determine what BP to nopwrite against, so we disable nopwrite. 1740 * 1741 * When syncing, the db_blkptr is initially the BP of the previous 1742 * txg. We can not nopwrite against it because it will be changed 1743 * (this is similar to the non-late-arrival case where the dbuf is 1744 * dirty in a future txg). 1745 * 1746 * Then dbuf_write_ready() sets bp_blkptr to the location we will write. 1747 * We can not nopwrite against it because although the BP will not 1748 * (typically) be changed, the data has not yet been persisted to this 1749 * location. 1750 * 1751 * Finally, when dbuf_write_done() is called, it is theoretically 1752 * possible to always nopwrite, because the data that was written in 1753 * this txg is the same data that we are trying to write. However we 1754 * would need to check that this dbuf is not dirty in any future 1755 * txg's (as we do in the normal dmu_sync() path). For simplicity, we 1756 * don't nopwrite in this case. 1757 */ 1758 zp->zp_nopwrite = B_FALSE; 1759 1760 zio_nowait(zio_write(pio, os->os_spa, dmu_tx_get_txg(tx), zgd->zgd_bp, 1761 abd_get_from_buf(zgd->zgd_db->db_data, zgd->zgd_db->db_size), 1762 zgd->zgd_db->db_size, zgd->zgd_db->db_size, zp, 1763 dmu_sync_late_arrival_ready, NULL, NULL, dmu_sync_late_arrival_done, 1764 dsa, ZIO_PRIORITY_SYNC_WRITE, ZIO_FLAG_CANFAIL, zb)); 1765 1766 return (0); 1767} 1768 1769/* 1770 * Intent log support: sync the block associated with db to disk. 1771 * N.B. and XXX: the caller is responsible for making sure that the 1772 * data isn't changing while dmu_sync() is writing it. 1773 * 1774 * Return values: 1775 * 1776 * EEXIST: this txg has already been synced, so there's nothing to do. 1777 * The caller should not log the write. 1778 * 1779 * ENOENT: the block was dbuf_free_range()'d, so there's nothing to do. 1780 * The caller should not log the write. 1781 * 1782 * EALREADY: this block is already in the process of being synced. 1783 * The caller should track its progress (somehow). 1784 * 1785 * EIO: could not do the I/O. 1786 * The caller should do a txg_wait_synced(). 1787 * 1788 * 0: the I/O has been initiated. 1789 * The caller should log this blkptr in the done callback. 1790 * It is possible that the I/O will fail, in which case 1791 * the error will be reported to the done callback and 1792 * propagated to pio from zio_done(). 1793 */ 1794int 1795dmu_sync(zio_t *pio, uint64_t txg, dmu_sync_cb_t *done, zgd_t *zgd) 1796{ 1797 dmu_buf_impl_t *db = (dmu_buf_impl_t *)zgd->zgd_db; 1798 objset_t *os = db->db_objset; 1799 dsl_dataset_t *ds = os->os_dsl_dataset; 1800 dbuf_dirty_record_t *dr; 1801 dmu_sync_arg_t *dsa; 1802 zbookmark_phys_t zb; 1803 zio_prop_t zp; 1804 dnode_t *dn; 1805 1806 ASSERT(pio != NULL); 1807 ASSERT(txg != 0); 1808 1809 SET_BOOKMARK(&zb, ds->ds_object, 1810 db->db.db_object, db->db_level, db->db_blkid); 1811 1812 DB_DNODE_ENTER(db); 1813 dn = DB_DNODE(db); 1814 dmu_write_policy(os, dn, db->db_level, WP_DMU_SYNC, &zp); 1815 DB_DNODE_EXIT(db); 1816 1817 /* 1818 * If we're frozen (running ziltest), we always need to generate a bp. 1819 */ 1820 if (txg > spa_freeze_txg(os->os_spa)) 1821 return (dmu_sync_late_arrival(pio, os, done, zgd, &zp, &zb)); 1822 1823 /* 1824 * Grabbing db_mtx now provides a barrier between dbuf_sync_leaf() 1825 * and us. If we determine that this txg is not yet syncing, 1826 * but it begins to sync a moment later, that's OK because the 1827 * sync thread will block in dbuf_sync_leaf() until we drop db_mtx. 1828 */ 1829 mutex_enter(&db->db_mtx); 1830 1831 if (txg <= spa_last_synced_txg(os->os_spa)) { 1832 /* 1833 * This txg has already synced. There's nothing to do. 1834 */ 1835 mutex_exit(&db->db_mtx); 1836 return (SET_ERROR(EEXIST)); 1837 } 1838 1839 if (txg <= spa_syncing_txg(os->os_spa)) { 1840 /* 1841 * This txg is currently syncing, so we can't mess with 1842 * the dirty record anymore; just write a new log block. 1843 */ 1844 mutex_exit(&db->db_mtx); 1845 return (dmu_sync_late_arrival(pio, os, done, zgd, &zp, &zb)); 1846 } 1847 1848 dr = db->db_last_dirty; 1849 while (dr && dr->dr_txg != txg) 1850 dr = dr->dr_next; 1851 1852 if (dr == NULL) { 1853 /* 1854 * There's no dr for this dbuf, so it must have been freed. 1855 * There's no need to log writes to freed blocks, so we're done. 1856 */ 1857 mutex_exit(&db->db_mtx); 1858 return (SET_ERROR(ENOENT)); 1859 } 1860 1861 ASSERT(dr->dr_next == NULL || dr->dr_next->dr_txg < txg); 1862 1863 if (db->db_blkptr != NULL) { 1864 /* 1865 * We need to fill in zgd_bp with the current blkptr so that 1866 * the nopwrite code can check if we're writing the same 1867 * data that's already on disk. We can only nopwrite if we 1868 * are sure that after making the copy, db_blkptr will not 1869 * change until our i/o completes. We ensure this by 1870 * holding the db_mtx, and only allowing nopwrite if the 1871 * block is not already dirty (see below). This is verified 1872 * by dmu_sync_done(), which VERIFYs that the db_blkptr has 1873 * not changed. 1874 */ 1875 *zgd->zgd_bp = *db->db_blkptr; 1876 } 1877 1878 /* 1879 * Assume the on-disk data is X, the current syncing data (in 1880 * txg - 1) is Y, and the current in-memory data is Z (currently 1881 * in dmu_sync). 1882 * 1883 * We usually want to perform a nopwrite if X and Z are the 1884 * same. However, if Y is different (i.e. the BP is going to 1885 * change before this write takes effect), then a nopwrite will 1886 * be incorrect - we would override with X, which could have 1887 * been freed when Y was written. 1888 * 1889 * (Note that this is not a concern when we are nop-writing from 1890 * syncing context, because X and Y must be identical, because 1891 * all previous txgs have been synced.) 1892 * 1893 * Therefore, we disable nopwrite if the current BP could change 1894 * before this TXG. There are two ways it could change: by 1895 * being dirty (dr_next is non-NULL), or by being freed 1896 * (dnode_block_freed()). This behavior is verified by 1897 * zio_done(), which VERIFYs that the override BP is identical 1898 * to the on-disk BP. 1899 */ 1900 DB_DNODE_ENTER(db); 1901 dn = DB_DNODE(db); 1902 if (dr->dr_next != NULL || dnode_block_freed(dn, db->db_blkid)) 1903 zp.zp_nopwrite = B_FALSE; 1904 DB_DNODE_EXIT(db); 1905 1906 ASSERT(dr->dr_txg == txg); 1907 if (dr->dt.dl.dr_override_state == DR_IN_DMU_SYNC || 1908 dr->dt.dl.dr_override_state == DR_OVERRIDDEN) { 1909 /* 1910 * We have already issued a sync write for this buffer, 1911 * or this buffer has already been synced. It could not 1912 * have been dirtied since, or we would have cleared the state. 1913 */ 1914 mutex_exit(&db->db_mtx); 1915 return (SET_ERROR(EALREADY)); 1916 } 1917 1918 ASSERT(dr->dt.dl.dr_override_state == DR_NOT_OVERRIDDEN); 1919 dr->dt.dl.dr_override_state = DR_IN_DMU_SYNC; 1920 mutex_exit(&db->db_mtx); 1921 1922 dsa = kmem_alloc(sizeof (dmu_sync_arg_t), KM_SLEEP); 1923 dsa->dsa_dr = dr; 1924 dsa->dsa_done = done; 1925 dsa->dsa_zgd = zgd; 1926 dsa->dsa_tx = NULL; 1927 1928 zio_nowait(arc_write(pio, os->os_spa, txg, 1929 zgd->zgd_bp, dr->dt.dl.dr_data, DBUF_IS_L2CACHEABLE(db), 1930 &zp, dmu_sync_ready, NULL, NULL, dmu_sync_done, dsa, 1931 ZIO_PRIORITY_SYNC_WRITE, ZIO_FLAG_CANFAIL, &zb)); 1932 1933 return (0); 1934} 1935 1936int 1937dmu_object_set_blocksize(objset_t *os, uint64_t object, uint64_t size, int ibs, 1938 dmu_tx_t *tx) 1939{ 1940 dnode_t *dn; 1941 int err; 1942 1943 err = dnode_hold(os, object, FTAG, &dn); 1944 if (err) 1945 return (err); 1946 err = dnode_set_blksz(dn, size, ibs, tx); 1947 dnode_rele(dn, FTAG); 1948 return (err); 1949} 1950 1951void 1952dmu_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 1971void 1972dmu_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 1990int zfs_mdcomp_disable = 0; 1991SYSCTL_INT(_vfs_zfs, OID_AUTO, mdcomp_disable, CTLFLAG_RWTUN, 1992 &zfs_mdcomp_disable, 0, "Disable metadata compression"); 1993 1994/* 1995 * When the "redundant_metadata" property is set to "most", only indirect 1996 * blocks of this level and higher will have an additional ditto block. 1997 */ 1998int zfs_redundant_metadata_most_ditto_level = 2; 1999 2000void 2001dmu_write_policy(objset_t *os, dnode_t *dn, int level, int wp, zio_prop_t *zp) 2002{ 2003 dmu_object_type_t type = dn ? dn->dn_type : DMU_OT_OBJSET; 2004 boolean_t ismd = (level > 0 || DMU_OT_IS_METADATA(type) || 2005 (wp & WP_SPILL)); 2006 enum zio_checksum checksum = os->os_checksum; 2007 enum zio_compress compress = os->os_compress; 2008 enum zio_checksum dedup_checksum = os->os_dedup_checksum; 2009 boolean_t dedup = B_FALSE; 2010 boolean_t nopwrite = B_FALSE; 2011 boolean_t dedup_verify = os->os_dedup_verify; 2012 int copies = os->os_copies; 2013 2014 /* 2015 * We maintain different write policies for each of the following 2016 * types of data: 2017 * 1. metadata 2018 * 2. preallocated blocks (i.e. level-0 blocks of a dump device) 2019 * 3. all other level 0 blocks 2020 */ 2021 if (ismd) { 2022 if (zfs_mdcomp_disable) { 2023 compress = ZIO_COMPRESS_EMPTY; 2024 } else { 2025 /* 2026 * XXX -- we should design a compression algorithm 2027 * that specializes in arrays of bps. 2028 */ 2029 compress = zio_compress_select(os->os_spa, 2030 ZIO_COMPRESS_ON, ZIO_COMPRESS_ON); 2031 } 2032 2033 /* 2034 * Metadata always gets checksummed. If the data 2035 * checksum is multi-bit correctable, and it's not a 2036 * ZBT-style checksum, then it's suitable for metadata 2037 * as well. Otherwise, the metadata checksum defaults 2038 * to fletcher4. 2039 */ 2040 if (!(zio_checksum_table[checksum].ci_flags & 2041 ZCHECKSUM_FLAG_METADATA) || 2042 (zio_checksum_table[checksum].ci_flags & 2043 ZCHECKSUM_FLAG_EMBEDDED)) 2044 checksum = ZIO_CHECKSUM_FLETCHER_4; 2045 2046 if (os->os_redundant_metadata == ZFS_REDUNDANT_METADATA_ALL || 2047 (os->os_redundant_metadata == 2048 ZFS_REDUNDANT_METADATA_MOST && 2049 (level >= zfs_redundant_metadata_most_ditto_level || 2050 DMU_OT_IS_METADATA(type) || (wp & WP_SPILL)))) 2051 copies++; 2052 } else if (wp & WP_NOFILL) { 2053 ASSERT(level == 0); 2054 2055 /* 2056 * If we're writing preallocated blocks, we aren't actually 2057 * writing them so don't set any policy properties. These 2058 * blocks are currently only used by an external subsystem 2059 * outside of zfs (i.e. dump) and not written by the zio 2060 * pipeline. 2061 */ 2062 compress = ZIO_COMPRESS_OFF; 2063 checksum = ZIO_CHECKSUM_NOPARITY; 2064 } else { 2065 compress = zio_compress_select(os->os_spa, dn->dn_compress, 2066 compress); 2067 2068 checksum = (dedup_checksum == ZIO_CHECKSUM_OFF) ? 2069 zio_checksum_select(dn->dn_checksum, checksum) : 2070 dedup_checksum; 2071 2072 /* 2073 * Determine dedup setting. If we are in dmu_sync(), 2074 * we won't actually dedup now because that's all 2075 * done in syncing context; but we do want to use the 2076 * dedup checkum. If the checksum is not strong 2077 * enough to ensure unique signatures, force 2078 * dedup_verify. 2079 */ 2080 if (dedup_checksum != ZIO_CHECKSUM_OFF) { 2081 dedup = (wp & WP_DMU_SYNC) ? B_FALSE : B_TRUE; 2082 if (!(zio_checksum_table[checksum].ci_flags & 2083 ZCHECKSUM_FLAG_DEDUP)) 2084 dedup_verify = B_TRUE; 2085 } 2086 2087 /* 2088 * Enable nopwrite if we have secure enough checksum 2089 * algorithm (see comment in zio_nop_write) and 2090 * compression is enabled. We don't enable nopwrite if 2091 * dedup is enabled as the two features are mutually 2092 * exclusive. 2093 */ 2094 nopwrite = (!dedup && (zio_checksum_table[checksum].ci_flags & 2095 ZCHECKSUM_FLAG_NOPWRITE) && 2096 compress != ZIO_COMPRESS_OFF && zfs_nopwrite_enabled); 2097 } 2098 2099 zp->zp_checksum = checksum; 2100 zp->zp_compress = compress; 2101 ASSERT3U(zp->zp_compress, !=, ZIO_COMPRESS_INHERIT); 2102 2103 zp->zp_type = (wp & WP_SPILL) ? dn->dn_bonustype : type; 2104 zp->zp_level = level; 2105 zp->zp_copies = MIN(copies, spa_max_replication(os->os_spa)); 2106 zp->zp_dedup = dedup; 2107 zp->zp_dedup_verify = dedup && dedup_verify; 2108 zp->zp_nopwrite = nopwrite; 2109} 2110 2111int 2112dmu_offset_next(objset_t *os, uint64_t object, boolean_t hole, uint64_t *off) 2113{ 2114 dnode_t *dn; 2115 int err; 2116 2117 /* 2118 * Sync any current changes before 2119 * we go trundling through the block pointers. 2120 */ 2121 err = dmu_object_wait_synced(os, object); 2122 if (err) { 2123 return (err); 2124 } 2125 2126 err = dnode_hold(os, object, FTAG, &dn); 2127 if (err) { 2128 return (err); 2129 } 2130 2131 err = dnode_next_offset(dn, (hole ? DNODE_FIND_HOLE : 0), off, 1, 1, 0); 2132 dnode_rele(dn, FTAG); 2133 2134 return (err); 2135} 2136 2137/* 2138 * Given the ZFS object, if it contains any dirty nodes 2139 * this function flushes all dirty blocks to disk. This 2140 * ensures the DMU object info is updated. A more efficient 2141 * future version might just find the TXG with the maximum 2142 * ID and wait for that to be synced. 2143 */ 2144int 2145dmu_object_wait_synced(objset_t *os, uint64_t object) 2146{ 2147 dnode_t *dn; 2148 int error, i; 2149 2150 error = dnode_hold(os, object, FTAG, &dn); 2151 if (error) { 2152 return (error); 2153 } 2154 2155 for (i = 0; i < TXG_SIZE; i++) { 2156 if (list_link_active(&dn->dn_dirty_link[i])) { 2157 break; 2158 } 2159 } 2160 dnode_rele(dn, FTAG); 2161 if (i != TXG_SIZE) { 2162 txg_wait_synced(dmu_objset_pool(os), 0); 2163 } 2164 2165 return (0); 2166} 2167 2168void 2169dmu_object_info_from_dnode(dnode_t *dn, dmu_object_info_t *doi) 2170{ 2171 dnode_phys_t *dnp; 2172 2173 rw_enter(&dn->dn_struct_rwlock, RW_READER); 2174 mutex_enter(&dn->dn_mtx); 2175 2176 dnp = dn->dn_phys; 2177 2178 doi->doi_data_block_size = dn->dn_datablksz; 2179 doi->doi_metadata_block_size = dn->dn_indblkshift ? 2180 1ULL << dn->dn_indblkshift : 0; 2181 doi->doi_type = dn->dn_type; 2182 doi->doi_bonus_type = dn->dn_bonustype; 2183 doi->doi_bonus_size = dn->dn_bonuslen; 2184 doi->doi_indirection = dn->dn_nlevels; 2185 doi->doi_checksum = dn->dn_checksum; 2186 doi->doi_compress = dn->dn_compress; 2187 doi->doi_nblkptr = dn->dn_nblkptr; 2188 doi->doi_physical_blocks_512 = (DN_USED_BYTES(dnp) + 256) >> 9; 2189 doi->doi_max_offset = (dn->dn_maxblkid + 1) * dn->dn_datablksz; 2190 doi->doi_fill_count = 0; 2191 for (int i = 0; i < dnp->dn_nblkptr; i++) 2192 doi->doi_fill_count += BP_GET_FILL(&dnp->dn_blkptr[i]); 2193 2194 mutex_exit(&dn->dn_mtx); 2195 rw_exit(&dn->dn_struct_rwlock); 2196} 2197 2198/* 2199 * Get information on a DMU object. 2200 * If doi is NULL, just indicates whether the object exists. 2201 */ 2202int 2203dmu_object_info(objset_t *os, uint64_t object, dmu_object_info_t *doi) 2204{ 2205 dnode_t *dn; 2206 int err = dnode_hold(os, object, FTAG, &dn); 2207 2208 if (err) 2209 return (err); 2210 2211 if (doi != NULL) 2212 dmu_object_info_from_dnode(dn, doi); 2213 2214 dnode_rele(dn, FTAG); 2215 return (0); 2216} 2217 2218/* 2219 * As above, but faster; can be used when you have a held dbuf in hand. 2220 */ 2221void 2222dmu_object_info_from_db(dmu_buf_t *db_fake, dmu_object_info_t *doi) 2223{ 2224 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake; 2225 2226 DB_DNODE_ENTER(db); 2227 dmu_object_info_from_dnode(DB_DNODE(db), doi); 2228 DB_DNODE_EXIT(db); 2229} 2230 2231/* 2232 * Faster still when you only care about the size. 2233 * This is specifically optimized for zfs_getattr(). 2234 */ 2235void 2236dmu_object_size_from_db(dmu_buf_t *db_fake, uint32_t *blksize, 2237 u_longlong_t *nblk512) 2238{ 2239 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake; 2240 dnode_t *dn; 2241 2242 DB_DNODE_ENTER(db); 2243 dn = DB_DNODE(db); 2244 2245 *blksize = dn->dn_datablksz; 2246 /* add 1 for dnode space */ 2247 *nblk512 = ((DN_USED_BYTES(dn->dn_phys) + SPA_MINBLOCKSIZE/2) >> 2248 SPA_MINBLOCKSHIFT) + 1; 2249 DB_DNODE_EXIT(db); 2250} 2251 2252void 2253byteswap_uint64_array(void *vbuf, size_t size) 2254{ 2255 uint64_t *buf = vbuf; 2256 size_t count = size >> 3; 2257 int i; 2258 2259 ASSERT((size & 7) == 0); 2260 2261 for (i = 0; i < count; i++) 2262 buf[i] = BSWAP_64(buf[i]); 2263} 2264 2265void 2266byteswap_uint32_array(void *vbuf, size_t size) 2267{ 2268 uint32_t *buf = vbuf; 2269 size_t count = size >> 2; 2270 int i; 2271 2272 ASSERT((size & 3) == 0); 2273 2274 for (i = 0; i < count; i++) 2275 buf[i] = BSWAP_32(buf[i]); 2276} 2277 2278void 2279byteswap_uint16_array(void *vbuf, size_t size) 2280{ 2281 uint16_t *buf = vbuf; 2282 size_t count = size >> 1; 2283 int i; 2284 2285 ASSERT((size & 1) == 0); 2286 2287 for (i = 0; i < count; i++) 2288 buf[i] = BSWAP_16(buf[i]); 2289} 2290 2291/* ARGSUSED */ 2292void 2293byteswap_uint8_array(void *vbuf, size_t size) 2294{ 2295} 2296 2297void 2298dmu_init(void) 2299{ 2300 abd_init(); 2301 zfs_dbgmsg_init(); 2302 sa_cache_init(); 2303 xuio_stat_init(); 2304 dmu_objset_init(); 2305 dnode_init(); 2306 zfetch_init(); 2307 zio_compress_init(); 2308 l2arc_init(); 2309 arc_init(); 2310 dbuf_init(); 2311} 2312 2313void 2314dmu_fini(void) 2315{ 2316 arc_fini(); /* arc depends on l2arc, so arc must go first */ 2317 l2arc_fini(); 2318 zfetch_fini(); 2319 zio_compress_fini(); 2320 dbuf_fini(); 2321 dnode_fini(); 2322 dmu_objset_fini(); 2323 xuio_stat_fini(); 2324 sa_cache_fini(); 2325 zfs_dbgmsg_fini(); 2326 abd_fini(); 2327} 2328