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 2011 Nexenta Systems, Inc. All rights reserved. 24 * Copyright (c) 2012, 2017 by Delphix. All rights reserved. 25 * Copyright (c) 2014 Integros [integros.com] 26 */ 27 28 #include <sys/dmu.h> 29 #include <sys/dmu_impl.h> 30 #include <sys/dbuf.h> 31 #include <sys/dmu_tx.h> 32 #include <sys/dmu_objset.h> 33 #include <sys/dsl_dataset.h> 34 #include <sys/dsl_dir.h> 35 #include <sys/dsl_pool.h> 36 #include <sys/zap_impl.h> 37 #include <sys/spa.h> 38 #include <sys/sa.h> 39 #include <sys/sa_impl.h> 40 #include <sys/zfs_context.h> 41 #include <sys/varargs.h> 42 43 typedef void (*dmu_tx_hold_func_t)(dmu_tx_t *tx, struct dnode *dn, 44 uint64_t arg1, uint64_t arg2); 45 46 47 dmu_tx_t * 48 dmu_tx_create_dd(dsl_dir_t *dd) 49 { 50 dmu_tx_t *tx = kmem_zalloc(sizeof (dmu_tx_t), KM_SLEEP); 51 tx->tx_dir = dd; 52 if (dd != NULL) 53 tx->tx_pool = dd->dd_pool; 54 list_create(&tx->tx_holds, sizeof (dmu_tx_hold_t), 55 offsetof(dmu_tx_hold_t, txh_node)); 56 list_create(&tx->tx_callbacks, sizeof (dmu_tx_callback_t), 57 offsetof(dmu_tx_callback_t, dcb_node)); 58 tx->tx_start = gethrtime(); 59 return (tx); 60 } 61 62 dmu_tx_t * 63 dmu_tx_create(objset_t *os) 64 { 65 dmu_tx_t *tx = dmu_tx_create_dd(os->os_dsl_dataset->ds_dir); 66 tx->tx_objset = os; 67 return (tx); 68 } 69 70 dmu_tx_t * 71 dmu_tx_create_assigned(struct dsl_pool *dp, uint64_t txg) 72 { 73 dmu_tx_t *tx = dmu_tx_create_dd(NULL); 74 75 txg_verify(dp->dp_spa, txg); 76 tx->tx_pool = dp; 77 tx->tx_txg = txg; 78 tx->tx_anyobj = TRUE; 79 80 return (tx); 81 } 82 83 int 84 dmu_tx_is_syncing(dmu_tx_t *tx) 85 { 86 return (tx->tx_anyobj); 87 } 88 89 int 90 dmu_tx_private_ok(dmu_tx_t *tx) 91 { 92 return (tx->tx_anyobj); 93 } 94 95 static dmu_tx_hold_t * 96 dmu_tx_hold_dnode_impl(dmu_tx_t *tx, dnode_t *dn, enum dmu_tx_hold_type type, 97 uint64_t arg1, uint64_t arg2) 98 { 99 dmu_tx_hold_t *txh; 100 101 if (dn != NULL) { 102 (void) refcount_add(&dn->dn_holds, tx); 103 if (tx->tx_txg != 0) { 104 mutex_enter(&dn->dn_mtx); 105 /* 106 * dn->dn_assigned_txg == tx->tx_txg doesn't pose a 107 * problem, but there's no way for it to happen (for 108 * now, at least). 109 */ 110 ASSERT(dn->dn_assigned_txg == 0); 111 dn->dn_assigned_txg = tx->tx_txg; 112 (void) refcount_add(&dn->dn_tx_holds, tx); 113 mutex_exit(&dn->dn_mtx); 114 } 115 } 116 117 txh = kmem_zalloc(sizeof (dmu_tx_hold_t), KM_SLEEP); 118 txh->txh_tx = tx; 119 txh->txh_dnode = dn; 120 refcount_create(&txh->txh_space_towrite); 121 refcount_create(&txh->txh_memory_tohold); 122 txh->txh_type = type; 123 txh->txh_arg1 = arg1; 124 txh->txh_arg2 = arg2; 125 list_insert_tail(&tx->tx_holds, txh); 126 127 return (txh); 128 } 129 130 static dmu_tx_hold_t * 131 dmu_tx_hold_object_impl(dmu_tx_t *tx, objset_t *os, uint64_t object, 132 enum dmu_tx_hold_type type, uint64_t arg1, uint64_t arg2) 133 { 134 dnode_t *dn = NULL; 135 dmu_tx_hold_t *txh; 136 int err; 137 138 if (object != DMU_NEW_OBJECT) { 139 err = dnode_hold(os, object, FTAG, &dn); 140 if (err != 0) { 141 tx->tx_err = err; 142 return (NULL); 143 } 144 } 145 txh = dmu_tx_hold_dnode_impl(tx, dn, type, arg1, arg2); 146 if (dn != NULL) 147 dnode_rele(dn, FTAG); 148 return (txh); 149 } 150 151 void 152 dmu_tx_add_new_object(dmu_tx_t *tx, dnode_t *dn) 153 { 154 /* 155 * If we're syncing, they can manipulate any object anyhow, and 156 * the hold on the dnode_t can cause problems. 157 */ 158 if (!dmu_tx_is_syncing(tx)) 159 (void) dmu_tx_hold_dnode_impl(tx, dn, THT_NEWOBJECT, 0, 0); 160 } 161 162 /* 163 * This function reads specified data from disk. The specified data will 164 * be needed to perform the transaction -- i.e, it will be read after 165 * we do dmu_tx_assign(). There are two reasons that we read the data now 166 * (before dmu_tx_assign()): 167 * 168 * 1. Reading it now has potentially better performance. The transaction 169 * has not yet been assigned, so the TXG is not held open, and also the 170 * caller typically has less locks held when calling dmu_tx_hold_*() than 171 * after the transaction has been assigned. This reduces the lock (and txg) 172 * hold times, thus reducing lock contention. 173 * 174 * 2. It is easier for callers (primarily the ZPL) to handle i/o errors 175 * that are detected before they start making changes to the DMU state 176 * (i.e. now). Once the transaction has been assigned, and some DMU 177 * state has been changed, it can be difficult to recover from an i/o 178 * error (e.g. to undo the changes already made in memory at the DMU 179 * layer). Typically code to do so does not exist in the caller -- it 180 * assumes that the data has already been cached and thus i/o errors are 181 * not possible. 182 * 183 * It has been observed that the i/o initiated here can be a performance 184 * problem, and it appears to be optional, because we don't look at the 185 * data which is read. However, removing this read would only serve to 186 * move the work elsewhere (after the dmu_tx_assign()), where it may 187 * have a greater impact on performance (in addition to the impact on 188 * fault tolerance noted above). 189 */ 190 static int 191 dmu_tx_check_ioerr(zio_t *zio, dnode_t *dn, int level, uint64_t blkid) 192 { 193 int err; 194 dmu_buf_impl_t *db; 195 196 rw_enter(&dn->dn_struct_rwlock, RW_READER); 197 db = dbuf_hold_level(dn, level, blkid, FTAG); 198 rw_exit(&dn->dn_struct_rwlock); 199 if (db == NULL) 200 return (SET_ERROR(EIO)); 201 err = dbuf_read(db, zio, DB_RF_CANFAIL | DB_RF_NOPREFETCH); 202 dbuf_rele(db, FTAG); 203 return (err); 204 } 205 206 /* ARGSUSED */ 207 static void 208 dmu_tx_count_write(dmu_tx_hold_t *txh, uint64_t off, uint64_t len) 209 { 210 dnode_t *dn = txh->txh_dnode; 211 int err = 0; 212 213 if (len == 0) 214 return; 215 216 (void) refcount_add_many(&txh->txh_space_towrite, len, FTAG); 217 218 if (refcount_count(&txh->txh_space_towrite) > 2 * DMU_MAX_ACCESS) 219 err = SET_ERROR(EFBIG); 220 221 if (dn == NULL) 222 return; 223 224 /* 225 * For i/o error checking, read the blocks that will be needed 226 * to perform the write: the first and last level-0 blocks (if 227 * they are not aligned, i.e. if they are partial-block writes), 228 * and all the level-1 blocks. 229 */ 230 if (dn->dn_maxblkid == 0) { 231 if (off < dn->dn_datablksz && 232 (off > 0 || len < dn->dn_datablksz)) { 233 err = dmu_tx_check_ioerr(NULL, dn, 0, 0); 234 if (err != 0) { 235 txh->txh_tx->tx_err = err; 236 } 237 } 238 } else { 239 zio_t *zio = zio_root(dn->dn_objset->os_spa, 240 NULL, NULL, ZIO_FLAG_CANFAIL); 241 242 /* first level-0 block */ 243 uint64_t start = off >> dn->dn_datablkshift; 244 if (P2PHASE(off, dn->dn_datablksz) || len < dn->dn_datablksz) { 245 err = dmu_tx_check_ioerr(zio, dn, 0, start); 246 if (err != 0) { 247 txh->txh_tx->tx_err = err; 248 } 249 } 250 251 /* last level-0 block */ 252 uint64_t end = (off + len - 1) >> dn->dn_datablkshift; 253 if (end != start && end <= dn->dn_maxblkid && 254 P2PHASE(off + len, dn->dn_datablksz)) { 255 err = dmu_tx_check_ioerr(zio, dn, 0, end); 256 if (err != 0) { 257 txh->txh_tx->tx_err = err; 258 } 259 } 260 261 /* level-1 blocks */ 262 if (dn->dn_nlevels > 1) { 263 int shft = dn->dn_indblkshift - SPA_BLKPTRSHIFT; 264 for (uint64_t i = (start >> shft) + 1; 265 i < end >> shft; i++) { 266 err = dmu_tx_check_ioerr(zio, dn, 1, i); 267 if (err != 0) { 268 txh->txh_tx->tx_err = err; 269 } 270 } 271 } 272 273 err = zio_wait(zio); 274 if (err != 0) { 275 txh->txh_tx->tx_err = err; 276 } 277 } 278 } 279 280 static void 281 dmu_tx_count_dnode(dmu_tx_hold_t *txh) 282 { 283 (void) refcount_add_many(&txh->txh_space_towrite, DNODE_SIZE, FTAG); 284 } 285 286 void 287 dmu_tx_hold_write(dmu_tx_t *tx, uint64_t object, uint64_t off, int len) 288 { 289 dmu_tx_hold_t *txh; 290 291 ASSERT0(tx->tx_txg); 292 ASSERT3U(len, <=, DMU_MAX_ACCESS); 293 ASSERT(len == 0 || UINT64_MAX - off >= len - 1); 294 295 txh = dmu_tx_hold_object_impl(tx, tx->tx_objset, 296 object, THT_WRITE, off, len); 297 if (txh != NULL) { 298 dmu_tx_count_write(txh, off, len); 299 dmu_tx_count_dnode(txh); 300 } 301 } 302 303 void 304 dmu_tx_hold_remap_l1indirect(dmu_tx_t *tx, uint64_t object) 305 { 306 dmu_tx_hold_t *txh; 307 308 ASSERT(tx->tx_txg == 0); 309 txh = dmu_tx_hold_object_impl(tx, tx->tx_objset, 310 object, THT_WRITE, 0, 0); 311 if (txh == NULL) 312 return; 313 314 dnode_t *dn = txh->txh_dnode; 315 (void) refcount_add_many(&txh->txh_space_towrite, 316 1ULL << dn->dn_indblkshift, FTAG); 317 dmu_tx_count_dnode(txh); 318 } 319 320 void 321 dmu_tx_hold_write_by_dnode(dmu_tx_t *tx, dnode_t *dn, uint64_t off, int len) 322 { 323 dmu_tx_hold_t *txh; 324 325 ASSERT0(tx->tx_txg); 326 ASSERT3U(len, <=, DMU_MAX_ACCESS); 327 ASSERT(len == 0 || UINT64_MAX - off >= len - 1); 328 329 txh = dmu_tx_hold_dnode_impl(tx, dn, THT_WRITE, off, len); 330 if (txh != NULL) { 331 dmu_tx_count_write(txh, off, len); 332 dmu_tx_count_dnode(txh); 333 } 334 } 335 336 /* 337 * This function marks the transaction as being a "net free". The end 338 * result is that refquotas will be disabled for this transaction, and 339 * this transaction will be able to use half of the pool space overhead 340 * (see dsl_pool_adjustedsize()). Therefore this function should only 341 * be called for transactions that we expect will not cause a net increase 342 * in the amount of space used (but it's OK if that is occasionally not true). 343 */ 344 void 345 dmu_tx_mark_netfree(dmu_tx_t *tx) 346 { 347 tx->tx_netfree = B_TRUE; 348 } 349 350 static void 351 dmu_tx_hold_free_impl(dmu_tx_hold_t *txh, uint64_t off, uint64_t len) 352 { 353 dmu_tx_t *tx; 354 dnode_t *dn; 355 int err; 356 357 tx = txh->txh_tx; 358 ASSERT(tx->tx_txg == 0); 359 360 dn = txh->txh_dnode; 361 dmu_tx_count_dnode(txh); 362 363 if (off >= (dn->dn_maxblkid + 1) * dn->dn_datablksz) 364 return; 365 if (len == DMU_OBJECT_END) 366 len = (dn->dn_maxblkid + 1) * dn->dn_datablksz - off; 367 368 /* 369 * For i/o error checking, we read the first and last level-0 370 * blocks if they are not aligned, and all the level-1 blocks. 371 * 372 * Note: dbuf_free_range() assumes that we have not instantiated 373 * any level-0 dbufs that will be completely freed. Therefore we must 374 * exercise care to not read or count the first and last blocks 375 * if they are blocksize-aligned. 376 */ 377 if (dn->dn_datablkshift == 0) { 378 if (off != 0 || len < dn->dn_datablksz) 379 dmu_tx_count_write(txh, 0, dn->dn_datablksz); 380 } else { 381 /* first block will be modified if it is not aligned */ 382 if (!IS_P2ALIGNED(off, 1 << dn->dn_datablkshift)) 383 dmu_tx_count_write(txh, off, 1); 384 /* last block will be modified if it is not aligned */ 385 if (!IS_P2ALIGNED(off + len, 1 << dn->dn_datablkshift)) 386 dmu_tx_count_write(txh, off + len, 1); 387 } 388 389 /* 390 * Check level-1 blocks. 391 */ 392 if (dn->dn_nlevels > 1) { 393 int shift = dn->dn_datablkshift + dn->dn_indblkshift - 394 SPA_BLKPTRSHIFT; 395 uint64_t start = off >> shift; 396 uint64_t end = (off + len) >> shift; 397 398 ASSERT(dn->dn_indblkshift != 0); 399 400 /* 401 * dnode_reallocate() can result in an object with indirect 402 * blocks having an odd data block size. In this case, 403 * just check the single block. 404 */ 405 if (dn->dn_datablkshift == 0) 406 start = end = 0; 407 408 zio_t *zio = zio_root(tx->tx_pool->dp_spa, 409 NULL, NULL, ZIO_FLAG_CANFAIL); 410 for (uint64_t i = start; i <= end; i++) { 411 uint64_t ibyte = i << shift; 412 err = dnode_next_offset(dn, 0, &ibyte, 2, 1, 0); 413 i = ibyte >> shift; 414 if (err == ESRCH || i > end) 415 break; 416 if (err != 0) { 417 tx->tx_err = err; 418 (void) zio_wait(zio); 419 return; 420 } 421 422 (void) refcount_add_many(&txh->txh_memory_tohold, 423 1 << dn->dn_indblkshift, FTAG); 424 425 err = dmu_tx_check_ioerr(zio, dn, 1, i); 426 if (err != 0) { 427 tx->tx_err = err; 428 (void) zio_wait(zio); 429 return; 430 } 431 } 432 err = zio_wait(zio); 433 if (err != 0) { 434 tx->tx_err = err; 435 return; 436 } 437 } 438 } 439 440 void 441 dmu_tx_hold_free(dmu_tx_t *tx, uint64_t object, uint64_t off, uint64_t len) 442 { 443 dmu_tx_hold_t *txh; 444 445 txh = dmu_tx_hold_object_impl(tx, tx->tx_objset, 446 object, THT_FREE, off, len); 447 if (txh != NULL) 448 (void) dmu_tx_hold_free_impl(txh, off, len); 449 } 450 451 void 452 dmu_tx_hold_free_by_dnode(dmu_tx_t *tx, dnode_t *dn, uint64_t off, uint64_t len) 453 { 454 dmu_tx_hold_t *txh; 455 456 txh = dmu_tx_hold_dnode_impl(tx, dn, THT_FREE, off, len); 457 if (txh != NULL) 458 (void) dmu_tx_hold_free_impl(txh, off, len); 459 } 460 461 static void 462 dmu_tx_hold_zap_impl(dmu_tx_hold_t *txh, const char *name) 463 { 464 dmu_tx_t *tx = txh->txh_tx; 465 dnode_t *dn; 466 int err; 467 468 ASSERT(tx->tx_txg == 0); 469 470 dn = txh->txh_dnode; 471 472 dmu_tx_count_dnode(txh); 473 474 /* 475 * Modifying a almost-full microzap is around the worst case (128KB) 476 * 477 * If it is a fat zap, the worst case would be 7*16KB=112KB: 478 * - 3 blocks overwritten: target leaf, ptrtbl block, header block 479 * - 4 new blocks written if adding: 480 * - 2 blocks for possibly split leaves, 481 * - 2 grown ptrtbl blocks 482 */ 483 (void) refcount_add_many(&txh->txh_space_towrite, 484 MZAP_MAX_BLKSZ, FTAG); 485 486 if (dn == NULL) 487 return; 488 489 ASSERT3P(DMU_OT_BYTESWAP(dn->dn_type), ==, DMU_BSWAP_ZAP); 490 491 if (dn->dn_maxblkid == 0 || name == NULL) { 492 /* 493 * This is a microzap (only one block), or we don't know 494 * the name. Check the first block for i/o errors. 495 */ 496 err = dmu_tx_check_ioerr(NULL, dn, 0, 0); 497 if (err != 0) { 498 tx->tx_err = err; 499 } 500 } else { 501 /* 502 * Access the name so that we'll check for i/o errors to 503 * the leaf blocks, etc. We ignore ENOENT, as this name 504 * may not yet exist. 505 */ 506 err = zap_lookup_by_dnode(dn, name, 8, 0, NULL); 507 if (err == EIO || err == ECKSUM || err == ENXIO) { 508 tx->tx_err = err; 509 } 510 } 511 } 512 513 void 514 dmu_tx_hold_zap(dmu_tx_t *tx, uint64_t object, int add, const char *name) 515 { 516 dmu_tx_hold_t *txh; 517 518 ASSERT0(tx->tx_txg); 519 520 txh = dmu_tx_hold_object_impl(tx, tx->tx_objset, 521 object, THT_ZAP, add, (uintptr_t)name); 522 if (txh != NULL) 523 dmu_tx_hold_zap_impl(txh, name); 524 } 525 526 void 527 dmu_tx_hold_zap_by_dnode(dmu_tx_t *tx, dnode_t *dn, int add, const char *name) 528 { 529 dmu_tx_hold_t *txh; 530 531 ASSERT0(tx->tx_txg); 532 ASSERT(dn != NULL); 533 534 txh = dmu_tx_hold_dnode_impl(tx, dn, THT_ZAP, add, (uintptr_t)name); 535 if (txh != NULL) 536 dmu_tx_hold_zap_impl(txh, name); 537 } 538 539 void 540 dmu_tx_hold_bonus(dmu_tx_t *tx, uint64_t object) 541 { 542 dmu_tx_hold_t *txh; 543 544 ASSERT(tx->tx_txg == 0); 545 546 txh = dmu_tx_hold_object_impl(tx, tx->tx_objset, 547 object, THT_BONUS, 0, 0); 548 if (txh) 549 dmu_tx_count_dnode(txh); 550 } 551 552 void 553 dmu_tx_hold_bonus_by_dnode(dmu_tx_t *tx, dnode_t *dn) 554 { 555 dmu_tx_hold_t *txh; 556 557 ASSERT0(tx->tx_txg); 558 559 txh = dmu_tx_hold_dnode_impl(tx, dn, THT_BONUS, 0, 0); 560 if (txh) 561 dmu_tx_count_dnode(txh); 562 } 563 564 void 565 dmu_tx_hold_space(dmu_tx_t *tx, uint64_t space) 566 { 567 dmu_tx_hold_t *txh; 568 ASSERT(tx->tx_txg == 0); 569 570 txh = dmu_tx_hold_object_impl(tx, tx->tx_objset, 571 DMU_NEW_OBJECT, THT_SPACE, space, 0); 572 573 (void) refcount_add_many(&txh->txh_space_towrite, space, FTAG); 574 } 575 576 #ifdef ZFS_DEBUG 577 void 578 dmu_tx_dirty_buf(dmu_tx_t *tx, dmu_buf_impl_t *db) 579 { 580 boolean_t match_object = B_FALSE; 581 boolean_t match_offset = B_FALSE; 582 583 DB_DNODE_ENTER(db); 584 dnode_t *dn = DB_DNODE(db); 585 ASSERT(tx->tx_txg != 0); 586 ASSERT(tx->tx_objset == NULL || dn->dn_objset == tx->tx_objset); 587 ASSERT3U(dn->dn_object, ==, db->db.db_object); 588 589 if (tx->tx_anyobj) { 590 DB_DNODE_EXIT(db); 591 return; 592 } 593 594 /* XXX No checking on the meta dnode for now */ 595 if (db->db.db_object == DMU_META_DNODE_OBJECT) { 596 DB_DNODE_EXIT(db); 597 return; 598 } 599 600 for (dmu_tx_hold_t *txh = list_head(&tx->tx_holds); txh != NULL; 601 txh = list_next(&tx->tx_holds, txh)) { 602 ASSERT(dn == NULL || dn->dn_assigned_txg == tx->tx_txg); 603 if (txh->txh_dnode == dn && txh->txh_type != THT_NEWOBJECT) 604 match_object = TRUE; 605 if (txh->txh_dnode == NULL || txh->txh_dnode == dn) { 606 int datablkshift = dn->dn_datablkshift ? 607 dn->dn_datablkshift : SPA_MAXBLOCKSHIFT; 608 int epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT; 609 int shift = datablkshift + epbs * db->db_level; 610 uint64_t beginblk = shift >= 64 ? 0 : 611 (txh->txh_arg1 >> shift); 612 uint64_t endblk = shift >= 64 ? 0 : 613 ((txh->txh_arg1 + txh->txh_arg2 - 1) >> shift); 614 uint64_t blkid = db->db_blkid; 615 616 /* XXX txh_arg2 better not be zero... */ 617 618 dprintf("found txh type %x beginblk=%llx endblk=%llx\n", 619 txh->txh_type, beginblk, endblk); 620 621 switch (txh->txh_type) { 622 case THT_WRITE: 623 if (blkid >= beginblk && blkid <= endblk) 624 match_offset = TRUE; 625 /* 626 * We will let this hold work for the bonus 627 * or spill buffer so that we don't need to 628 * hold it when creating a new object. 629 */ 630 if (blkid == DMU_BONUS_BLKID || 631 blkid == DMU_SPILL_BLKID) 632 match_offset = TRUE; 633 /* 634 * They might have to increase nlevels, 635 * thus dirtying the new TLIBs. Or the 636 * might have to change the block size, 637 * thus dirying the new lvl=0 blk=0. 638 */ 639 if (blkid == 0) 640 match_offset = TRUE; 641 break; 642 case THT_FREE: 643 /* 644 * We will dirty all the level 1 blocks in 645 * the free range and perhaps the first and 646 * last level 0 block. 647 */ 648 if (blkid >= beginblk && (blkid <= endblk || 649 txh->txh_arg2 == DMU_OBJECT_END)) 650 match_offset = TRUE; 651 break; 652 case THT_SPILL: 653 if (blkid == DMU_SPILL_BLKID) 654 match_offset = TRUE; 655 break; 656 case THT_BONUS: 657 if (blkid == DMU_BONUS_BLKID) 658 match_offset = TRUE; 659 break; 660 case THT_ZAP: 661 match_offset = TRUE; 662 break; 663 case THT_NEWOBJECT: 664 match_object = TRUE; 665 break; 666 default: 667 ASSERT(!"bad txh_type"); 668 } 669 } 670 if (match_object && match_offset) { 671 DB_DNODE_EXIT(db); 672 return; 673 } 674 } 675 DB_DNODE_EXIT(db); 676 panic("dirtying dbuf obj=%llx lvl=%u blkid=%llx but not tx_held\n", 677 (u_longlong_t)db->db.db_object, db->db_level, 678 (u_longlong_t)db->db_blkid); 679 } 680 #endif 681 682 /* 683 * If we can't do 10 iops, something is wrong. Let us go ahead 684 * and hit zfs_dirty_data_max. 685 */ 686 hrtime_t zfs_delay_max_ns = MSEC2NSEC(100); 687 int zfs_delay_resolution_ns = 100 * 1000; /* 100 microseconds */ 688 689 /* 690 * We delay transactions when we've determined that the backend storage 691 * isn't able to accommodate the rate of incoming writes. 692 * 693 * If there is already a transaction waiting, we delay relative to when 694 * that transaction finishes waiting. This way the calculated min_time 695 * is independent of the number of threads concurrently executing 696 * transactions. 697 * 698 * If we are the only waiter, wait relative to when the transaction 699 * started, rather than the current time. This credits the transaction for 700 * "time already served", e.g. reading indirect blocks. 701 * 702 * The minimum time for a transaction to take is calculated as: 703 * min_time = scale * (dirty - min) / (max - dirty) 704 * min_time is then capped at zfs_delay_max_ns. 705 * 706 * The delay has two degrees of freedom that can be adjusted via tunables. 707 * The percentage of dirty data at which we start to delay is defined by 708 * zfs_delay_min_dirty_percent. This should typically be at or above 709 * zfs_vdev_async_write_active_max_dirty_percent so that we only start to 710 * delay after writing at full speed has failed to keep up with the incoming 711 * write rate. The scale of the curve is defined by zfs_delay_scale. Roughly 712 * speaking, this variable determines the amount of delay at the midpoint of 713 * the curve. 714 * 715 * delay 716 * 10ms +-------------------------------------------------------------*+ 717 * | *| 718 * 9ms + *+ 719 * | *| 720 * 8ms + *+ 721 * | * | 722 * 7ms + * + 723 * | * | 724 * 6ms + * + 725 * | * | 726 * 5ms + * + 727 * | * | 728 * 4ms + * + 729 * | * | 730 * 3ms + * + 731 * | * | 732 * 2ms + (midpoint) * + 733 * | | ** | 734 * 1ms + v *** + 735 * | zfs_delay_scale ----------> ******** | 736 * 0 +-------------------------------------*********----------------+ 737 * 0% <- zfs_dirty_data_max -> 100% 738 * 739 * Note that since the delay is added to the outstanding time remaining on the 740 * most recent transaction, the delay is effectively the inverse of IOPS. 741 * Here the midpoint of 500us translates to 2000 IOPS. The shape of the curve 742 * was chosen such that small changes in the amount of accumulated dirty data 743 * in the first 3/4 of the curve yield relatively small differences in the 744 * amount of delay. 745 * 746 * The effects can be easier to understand when the amount of delay is 747 * represented on a log scale: 748 * 749 * delay 750 * 100ms +-------------------------------------------------------------++ 751 * + + 752 * | | 753 * + *+ 754 * 10ms + *+ 755 * + ** + 756 * | (midpoint) ** | 757 * + | ** + 758 * 1ms + v **** + 759 * + zfs_delay_scale ----------> ***** + 760 * | **** | 761 * + **** + 762 * 100us + ** + 763 * + * + 764 * | * | 765 * + * + 766 * 10us + * + 767 * + + 768 * | | 769 * + + 770 * +--------------------------------------------------------------+ 771 * 0% <- zfs_dirty_data_max -> 100% 772 * 773 * Note here that only as the amount of dirty data approaches its limit does 774 * the delay start to increase rapidly. The goal of a properly tuned system 775 * should be to keep the amount of dirty data out of that range by first 776 * ensuring that the appropriate limits are set for the I/O scheduler to reach 777 * optimal throughput on the backend storage, and then by changing the value 778 * of zfs_delay_scale to increase the steepness of the curve. 779 */ 780 static void 781 dmu_tx_delay(dmu_tx_t *tx, uint64_t dirty) 782 { 783 dsl_pool_t *dp = tx->tx_pool; 784 uint64_t delay_min_bytes = 785 zfs_dirty_data_max * zfs_delay_min_dirty_percent / 100; 786 hrtime_t wakeup, min_tx_time, now; 787 788 if (dirty <= delay_min_bytes) 789 return; 790 791 /* 792 * The caller has already waited until we are under the max. 793 * We make them pass us the amount of dirty data so we don't 794 * have to handle the case of it being >= the max, which could 795 * cause a divide-by-zero if it's == the max. 796 */ 797 ASSERT3U(dirty, <, zfs_dirty_data_max); 798 799 now = gethrtime(); 800 min_tx_time = zfs_delay_scale * 801 (dirty - delay_min_bytes) / (zfs_dirty_data_max - dirty); 802 if (now > tx->tx_start + min_tx_time) 803 return; 804 805 min_tx_time = MIN(min_tx_time, zfs_delay_max_ns); 806 807 DTRACE_PROBE3(delay__mintime, dmu_tx_t *, tx, uint64_t, dirty, 808 uint64_t, min_tx_time); 809 810 mutex_enter(&dp->dp_lock); 811 wakeup = MAX(tx->tx_start + min_tx_time, 812 dp->dp_last_wakeup + min_tx_time); 813 dp->dp_last_wakeup = wakeup; 814 mutex_exit(&dp->dp_lock); 815 816 #ifdef _KERNEL 817 mutex_enter(&curthread->t_delay_lock); 818 while (cv_timedwait_hires(&curthread->t_delay_cv, 819 &curthread->t_delay_lock, wakeup, zfs_delay_resolution_ns, 820 CALLOUT_FLAG_ABSOLUTE | CALLOUT_FLAG_ROUNDUP) > 0) 821 continue; 822 mutex_exit(&curthread->t_delay_lock); 823 #else 824 hrtime_t delta = wakeup - gethrtime(); 825 struct timespec ts; 826 ts.tv_sec = delta / NANOSEC; 827 ts.tv_nsec = delta % NANOSEC; 828 (void) nanosleep(&ts, NULL); 829 #endif 830 } 831 832 /* 833 * This routine attempts to assign the transaction to a transaction group. 834 * To do so, we must determine if there is sufficient free space on disk. 835 * 836 * If this is a "netfree" transaction (i.e. we called dmu_tx_mark_netfree() 837 * on it), then it is assumed that there is sufficient free space, 838 * unless there's insufficient slop space in the pool (see the comment 839 * above spa_slop_shift in spa_misc.c). 840 * 841 * If it is not a "netfree" transaction, then if the data already on disk 842 * is over the allowed usage (e.g. quota), this will fail with EDQUOT or 843 * ENOSPC. Otherwise, if the current rough estimate of pending changes, 844 * plus the rough estimate of this transaction's changes, may exceed the 845 * allowed usage, then this will fail with ERESTART, which will cause the 846 * caller to wait for the pending changes to be written to disk (by waiting 847 * for the next TXG to open), and then check the space usage again. 848 * 849 * The rough estimate of pending changes is comprised of the sum of: 850 * 851 * - this transaction's holds' txh_space_towrite 852 * 853 * - dd_tempreserved[], which is the sum of in-flight transactions' 854 * holds' txh_space_towrite (i.e. those transactions that have called 855 * dmu_tx_assign() but not yet called dmu_tx_commit()). 856 * 857 * - dd_space_towrite[], which is the amount of dirtied dbufs. 858 * 859 * Note that all of these values are inflated by spa_get_worst_case_asize(), 860 * which means that we may get ERESTART well before we are actually in danger 861 * of running out of space, but this also mitigates any small inaccuracies 862 * in the rough estimate (e.g. txh_space_towrite doesn't take into account 863 * indirect blocks, and dd_space_towrite[] doesn't take into account changes 864 * to the MOS). 865 * 866 * Note that due to this algorithm, it is possible to exceed the allowed 867 * usage by one transaction. Also, as we approach the allowed usage, 868 * we will allow a very limited amount of changes into each TXG, thus 869 * decreasing performance. 870 */ 871 static int 872 dmu_tx_try_assign(dmu_tx_t *tx, uint64_t txg_how) 873 { 874 spa_t *spa = tx->tx_pool->dp_spa; 875 876 ASSERT0(tx->tx_txg); 877 878 if (tx->tx_err) 879 return (tx->tx_err); 880 881 if (spa_suspended(spa)) { 882 /* 883 * If the user has indicated a blocking failure mode 884 * then return ERESTART which will block in dmu_tx_wait(). 885 * Otherwise, return EIO so that an error can get 886 * propagated back to the VOP calls. 887 * 888 * Note that we always honor the txg_how flag regardless 889 * of the failuremode setting. 890 */ 891 if (spa_get_failmode(spa) == ZIO_FAILURE_MODE_CONTINUE && 892 !(txg_how & TXG_WAIT)) 893 return (SET_ERROR(EIO)); 894 895 return (SET_ERROR(ERESTART)); 896 } 897 898 if (!tx->tx_dirty_delayed && 899 dsl_pool_need_dirty_delay(tx->tx_pool)) { 900 tx->tx_wait_dirty = B_TRUE; 901 return (SET_ERROR(ERESTART)); 902 } 903 904 tx->tx_txg = txg_hold_open(tx->tx_pool, &tx->tx_txgh); 905 tx->tx_needassign_txh = NULL; 906 907 /* 908 * NB: No error returns are allowed after txg_hold_open, but 909 * before processing the dnode holds, due to the 910 * dmu_tx_unassign() logic. 911 */ 912 913 uint64_t towrite = 0; 914 uint64_t tohold = 0; 915 for (dmu_tx_hold_t *txh = list_head(&tx->tx_holds); txh != NULL; 916 txh = list_next(&tx->tx_holds, txh)) { 917 dnode_t *dn = txh->txh_dnode; 918 if (dn != NULL) { 919 mutex_enter(&dn->dn_mtx); 920 if (dn->dn_assigned_txg == tx->tx_txg - 1) { 921 mutex_exit(&dn->dn_mtx); 922 tx->tx_needassign_txh = txh; 923 return (SET_ERROR(ERESTART)); 924 } 925 if (dn->dn_assigned_txg == 0) 926 dn->dn_assigned_txg = tx->tx_txg; 927 ASSERT3U(dn->dn_assigned_txg, ==, tx->tx_txg); 928 (void) refcount_add(&dn->dn_tx_holds, tx); 929 mutex_exit(&dn->dn_mtx); 930 } 931 towrite += refcount_count(&txh->txh_space_towrite); 932 tohold += refcount_count(&txh->txh_memory_tohold); 933 } 934 935 /* needed allocation: worst-case estimate of write space */ 936 uint64_t asize = spa_get_worst_case_asize(tx->tx_pool->dp_spa, towrite); 937 /* calculate memory footprint estimate */ 938 uint64_t memory = towrite + tohold; 939 940 if (tx->tx_dir != NULL && asize != 0) { 941 int err = dsl_dir_tempreserve_space(tx->tx_dir, memory, 942 asize, tx->tx_netfree, &tx->tx_tempreserve_cookie, tx); 943 if (err != 0) 944 return (err); 945 } 946 947 return (0); 948 } 949 950 static void 951 dmu_tx_unassign(dmu_tx_t *tx) 952 { 953 if (tx->tx_txg == 0) 954 return; 955 956 txg_rele_to_quiesce(&tx->tx_txgh); 957 958 /* 959 * Walk the transaction's hold list, removing the hold on the 960 * associated dnode, and notifying waiters if the refcount drops to 0. 961 */ 962 for (dmu_tx_hold_t *txh = list_head(&tx->tx_holds); 963 txh != tx->tx_needassign_txh; 964 txh = list_next(&tx->tx_holds, txh)) { 965 dnode_t *dn = txh->txh_dnode; 966 967 if (dn == NULL) 968 continue; 969 mutex_enter(&dn->dn_mtx); 970 ASSERT3U(dn->dn_assigned_txg, ==, tx->tx_txg); 971 972 if (refcount_remove(&dn->dn_tx_holds, tx) == 0) { 973 dn->dn_assigned_txg = 0; 974 cv_broadcast(&dn->dn_notxholds); 975 } 976 mutex_exit(&dn->dn_mtx); 977 } 978 979 txg_rele_to_sync(&tx->tx_txgh); 980 981 tx->tx_lasttried_txg = tx->tx_txg; 982 tx->tx_txg = 0; 983 } 984 985 /* 986 * Assign tx to a transaction group; txg_how is a bitmask: 987 * 988 * If TXG_WAIT is set and the currently open txg is full, this function 989 * will wait until there's a new txg. This should be used when no locks 990 * are being held. With this bit set, this function will only fail if 991 * we're truly out of space (or over quota). 992 * 993 * If TXG_WAIT is *not* set and we can't assign into the currently open 994 * txg without blocking, this function will return immediately with 995 * ERESTART. This should be used whenever locks are being held. On an 996 * ERESTART error, the caller should drop all locks, call dmu_tx_wait(), 997 * and try again. 998 * 999 * If TXG_NOTHROTTLE is set, this indicates that this tx should not be 1000 * delayed due on the ZFS Write Throttle (see comments in dsl_pool.c for 1001 * details on the throttle). This is used by the VFS operations, after 1002 * they have already called dmu_tx_wait() (though most likely on a 1003 * different tx). 1004 */ 1005 int 1006 dmu_tx_assign(dmu_tx_t *tx, uint64_t txg_how) 1007 { 1008 int err; 1009 1010 ASSERT(tx->tx_txg == 0); 1011 ASSERT0(txg_how & ~(TXG_WAIT | TXG_NOTHROTTLE)); 1012 ASSERT(!dsl_pool_sync_context(tx->tx_pool)); 1013 1014 /* If we might wait, we must not hold the config lock. */ 1015 IMPLY((txg_how & TXG_WAIT), !dsl_pool_config_held(tx->tx_pool)); 1016 1017 if ((txg_how & TXG_NOTHROTTLE)) 1018 tx->tx_dirty_delayed = B_TRUE; 1019 1020 while ((err = dmu_tx_try_assign(tx, txg_how)) != 0) { 1021 dmu_tx_unassign(tx); 1022 1023 if (err != ERESTART || !(txg_how & TXG_WAIT)) 1024 return (err); 1025 1026 dmu_tx_wait(tx); 1027 } 1028 1029 txg_rele_to_quiesce(&tx->tx_txgh); 1030 1031 return (0); 1032 } 1033 1034 void 1035 dmu_tx_wait(dmu_tx_t *tx) 1036 { 1037 spa_t *spa = tx->tx_pool->dp_spa; 1038 dsl_pool_t *dp = tx->tx_pool; 1039 1040 ASSERT(tx->tx_txg == 0); 1041 ASSERT(!dsl_pool_config_held(tx->tx_pool)); 1042 1043 if (tx->tx_wait_dirty) { 1044 /* 1045 * dmu_tx_try_assign() has determined that we need to wait 1046 * because we've consumed much or all of the dirty buffer 1047 * space. 1048 */ 1049 mutex_enter(&dp->dp_lock); 1050 while (dp->dp_dirty_total >= zfs_dirty_data_max) 1051 cv_wait(&dp->dp_spaceavail_cv, &dp->dp_lock); 1052 uint64_t dirty = dp->dp_dirty_total; 1053 mutex_exit(&dp->dp_lock); 1054 1055 dmu_tx_delay(tx, dirty); 1056 1057 tx->tx_wait_dirty = B_FALSE; 1058 1059 /* 1060 * Note: setting tx_dirty_delayed only has effect if the 1061 * caller used TX_WAIT. Otherwise they are going to 1062 * destroy this tx and try again. The common case, 1063 * zfs_write(), uses TX_WAIT. 1064 */ 1065 tx->tx_dirty_delayed = B_TRUE; 1066 } else if (spa_suspended(spa) || tx->tx_lasttried_txg == 0) { 1067 /* 1068 * If the pool is suspended we need to wait until it 1069 * is resumed. Note that it's possible that the pool 1070 * has become active after this thread has tried to 1071 * obtain a tx. If that's the case then tx_lasttried_txg 1072 * would not have been set. 1073 */ 1074 txg_wait_synced(dp, spa_last_synced_txg(spa) + 1); 1075 } else if (tx->tx_needassign_txh) { 1076 /* 1077 * A dnode is assigned to the quiescing txg. Wait for its 1078 * transaction to complete. 1079 */ 1080 dnode_t *dn = tx->tx_needassign_txh->txh_dnode; 1081 1082 mutex_enter(&dn->dn_mtx); 1083 while (dn->dn_assigned_txg == tx->tx_lasttried_txg - 1) 1084 cv_wait(&dn->dn_notxholds, &dn->dn_mtx); 1085 mutex_exit(&dn->dn_mtx); 1086 tx->tx_needassign_txh = NULL; 1087 } else { 1088 /* 1089 * If we have a lot of dirty data just wait until we sync 1090 * out a TXG at which point we'll hopefully have synced 1091 * a portion of the changes. 1092 */ 1093 txg_wait_synced(dp, spa_last_synced_txg(spa) + 1); 1094 } 1095 } 1096 1097 static void 1098 dmu_tx_destroy(dmu_tx_t *tx) 1099 { 1100 dmu_tx_hold_t *txh; 1101 1102 while ((txh = list_head(&tx->tx_holds)) != NULL) { 1103 dnode_t *dn = txh->txh_dnode; 1104 1105 list_remove(&tx->tx_holds, txh); 1106 refcount_destroy_many(&txh->txh_space_towrite, 1107 refcount_count(&txh->txh_space_towrite)); 1108 refcount_destroy_many(&txh->txh_memory_tohold, 1109 refcount_count(&txh->txh_memory_tohold)); 1110 kmem_free(txh, sizeof (dmu_tx_hold_t)); 1111 if (dn != NULL) 1112 dnode_rele(dn, tx); 1113 } 1114 1115 list_destroy(&tx->tx_callbacks); 1116 list_destroy(&tx->tx_holds); 1117 kmem_free(tx, sizeof (dmu_tx_t)); 1118 } 1119 1120 void 1121 dmu_tx_commit(dmu_tx_t *tx) 1122 { 1123 ASSERT(tx->tx_txg != 0); 1124 1125 /* 1126 * Go through the transaction's hold list and remove holds on 1127 * associated dnodes, notifying waiters if no holds remain. 1128 */ 1129 for (dmu_tx_hold_t *txh = list_head(&tx->tx_holds); txh != NULL; 1130 txh = list_next(&tx->tx_holds, txh)) { 1131 dnode_t *dn = txh->txh_dnode; 1132 1133 if (dn == NULL) 1134 continue; 1135 1136 mutex_enter(&dn->dn_mtx); 1137 ASSERT3U(dn->dn_assigned_txg, ==, tx->tx_txg); 1138 1139 if (refcount_remove(&dn->dn_tx_holds, tx) == 0) { 1140 dn->dn_assigned_txg = 0; 1141 cv_broadcast(&dn->dn_notxholds); 1142 } 1143 mutex_exit(&dn->dn_mtx); 1144 } 1145 1146 if (tx->tx_tempreserve_cookie) 1147 dsl_dir_tempreserve_clear(tx->tx_tempreserve_cookie, tx); 1148 1149 if (!list_is_empty(&tx->tx_callbacks)) 1150 txg_register_callbacks(&tx->tx_txgh, &tx->tx_callbacks); 1151 1152 if (tx->tx_anyobj == FALSE) 1153 txg_rele_to_sync(&tx->tx_txgh); 1154 1155 dmu_tx_destroy(tx); 1156 } 1157 1158 void 1159 dmu_tx_abort(dmu_tx_t *tx) 1160 { 1161 ASSERT(tx->tx_txg == 0); 1162 1163 /* 1164 * Call any registered callbacks with an error code. 1165 */ 1166 if (!list_is_empty(&tx->tx_callbacks)) 1167 dmu_tx_do_callbacks(&tx->tx_callbacks, ECANCELED); 1168 1169 dmu_tx_destroy(tx); 1170 } 1171 1172 uint64_t 1173 dmu_tx_get_txg(dmu_tx_t *tx) 1174 { 1175 ASSERT(tx->tx_txg != 0); 1176 return (tx->tx_txg); 1177 } 1178 1179 dsl_pool_t * 1180 dmu_tx_pool(dmu_tx_t *tx) 1181 { 1182 ASSERT(tx->tx_pool != NULL); 1183 return (tx->tx_pool); 1184 } 1185 1186 void 1187 dmu_tx_callback_register(dmu_tx_t *tx, dmu_tx_callback_func_t *func, void *data) 1188 { 1189 dmu_tx_callback_t *dcb; 1190 1191 dcb = kmem_alloc(sizeof (dmu_tx_callback_t), KM_SLEEP); 1192 1193 dcb->dcb_func = func; 1194 dcb->dcb_data = data; 1195 1196 list_insert_tail(&tx->tx_callbacks, dcb); 1197 } 1198 1199 /* 1200 * Call all the commit callbacks on a list, with a given error code. 1201 */ 1202 void 1203 dmu_tx_do_callbacks(list_t *cb_list, int error) 1204 { 1205 dmu_tx_callback_t *dcb; 1206 1207 while ((dcb = list_head(cb_list)) != NULL) { 1208 list_remove(cb_list, dcb); 1209 dcb->dcb_func(dcb->dcb_data, error); 1210 kmem_free(dcb, sizeof (dmu_tx_callback_t)); 1211 } 1212 } 1213 1214 /* 1215 * Interface to hold a bunch of attributes. 1216 * used for creating new files. 1217 * attrsize is the total size of all attributes 1218 * to be added during object creation 1219 * 1220 * For updating/adding a single attribute dmu_tx_hold_sa() should be used. 1221 */ 1222 1223 /* 1224 * hold necessary attribute name for attribute registration. 1225 * should be a very rare case where this is needed. If it does 1226 * happen it would only happen on the first write to the file system. 1227 */ 1228 static void 1229 dmu_tx_sa_registration_hold(sa_os_t *sa, dmu_tx_t *tx) 1230 { 1231 if (!sa->sa_need_attr_registration) 1232 return; 1233 1234 for (int i = 0; i != sa->sa_num_attrs; i++) { 1235 if (!sa->sa_attr_table[i].sa_registered) { 1236 if (sa->sa_reg_attr_obj) 1237 dmu_tx_hold_zap(tx, sa->sa_reg_attr_obj, 1238 B_TRUE, sa->sa_attr_table[i].sa_name); 1239 else 1240 dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, 1241 B_TRUE, sa->sa_attr_table[i].sa_name); 1242 } 1243 } 1244 } 1245 1246 void 1247 dmu_tx_hold_spill(dmu_tx_t *tx, uint64_t object) 1248 { 1249 dmu_tx_hold_t *txh = dmu_tx_hold_object_impl(tx, 1250 tx->tx_objset, object, THT_SPILL, 0, 0); 1251 1252 (void) refcount_add_many(&txh->txh_space_towrite, 1253 SPA_OLD_MAXBLOCKSIZE, FTAG); 1254 } 1255 1256 void 1257 dmu_tx_hold_sa_create(dmu_tx_t *tx, int attrsize) 1258 { 1259 sa_os_t *sa = tx->tx_objset->os_sa; 1260 1261 dmu_tx_hold_bonus(tx, DMU_NEW_OBJECT); 1262 1263 if (tx->tx_objset->os_sa->sa_master_obj == 0) 1264 return; 1265 1266 if (tx->tx_objset->os_sa->sa_layout_attr_obj) { 1267 dmu_tx_hold_zap(tx, sa->sa_layout_attr_obj, B_TRUE, NULL); 1268 } else { 1269 dmu_tx_hold_zap(tx, sa->sa_master_obj, B_TRUE, SA_LAYOUTS); 1270 dmu_tx_hold_zap(tx, sa->sa_master_obj, B_TRUE, SA_REGISTRY); 1271 dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, B_TRUE, NULL); 1272 dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, B_TRUE, NULL); 1273 } 1274 1275 dmu_tx_sa_registration_hold(sa, tx); 1276 1277 if (attrsize <= DN_MAX_BONUSLEN && !sa->sa_force_spill) 1278 return; 1279 1280 (void) dmu_tx_hold_object_impl(tx, tx->tx_objset, DMU_NEW_OBJECT, 1281 THT_SPILL, 0, 0); 1282 } 1283 1284 /* 1285 * Hold SA attribute 1286 * 1287 * dmu_tx_hold_sa(dmu_tx_t *tx, sa_handle_t *, attribute, add, size) 1288 * 1289 * variable_size is the total size of all variable sized attributes 1290 * passed to this function. It is not the total size of all 1291 * variable size attributes that *may* exist on this object. 1292 */ 1293 void 1294 dmu_tx_hold_sa(dmu_tx_t *tx, sa_handle_t *hdl, boolean_t may_grow) 1295 { 1296 uint64_t object; 1297 sa_os_t *sa = tx->tx_objset->os_sa; 1298 1299 ASSERT(hdl != NULL); 1300 1301 object = sa_handle_object(hdl); 1302 1303 dmu_tx_hold_bonus(tx, object); 1304 1305 if (tx->tx_objset->os_sa->sa_master_obj == 0) 1306 return; 1307 1308 if (tx->tx_objset->os_sa->sa_reg_attr_obj == 0 || 1309 tx->tx_objset->os_sa->sa_layout_attr_obj == 0) { 1310 dmu_tx_hold_zap(tx, sa->sa_master_obj, B_TRUE, SA_LAYOUTS); 1311 dmu_tx_hold_zap(tx, sa->sa_master_obj, B_TRUE, SA_REGISTRY); 1312 dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, B_TRUE, NULL); 1313 dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, B_TRUE, NULL); 1314 } 1315 1316 dmu_tx_sa_registration_hold(sa, tx); 1317 1318 if (may_grow && tx->tx_objset->os_sa->sa_layout_attr_obj) 1319 dmu_tx_hold_zap(tx, sa->sa_layout_attr_obj, B_TRUE, NULL); 1320 1321 if (sa->sa_force_spill || may_grow || hdl->sa_spill) { 1322 ASSERT(tx->tx_txg == 0); 1323 dmu_tx_hold_spill(tx, object); 1324 } else { 1325 dmu_buf_impl_t *db = (dmu_buf_impl_t *)hdl->sa_bonus; 1326 dnode_t *dn; 1327 1328 DB_DNODE_ENTER(db); 1329 dn = DB_DNODE(db); 1330 if (dn->dn_have_spill) { 1331 ASSERT(tx->tx_txg == 0); 1332 dmu_tx_hold_spill(tx, object); 1333 } 1334 DB_DNODE_EXIT(db); 1335 } 1336 } 1337