1/* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or https://opensource.org/licenses/CDDL-1.0. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21/* 22 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. 23 * Copyright 2011 Nexenta Systems, Inc. All rights reserved. 24 * Copyright (c) 2012, 2017 by Delphix. All rights reserved. 25 */ 26 27#include <sys/dmu.h> 28#include <sys/dmu_impl.h> 29#include <sys/dbuf.h> 30#include <sys/dmu_tx.h> 31#include <sys/dmu_objset.h> 32#include <sys/dsl_dataset.h> 33#include <sys/dsl_dir.h> 34#include <sys/dsl_pool.h> 35#include <sys/zap_impl.h> 36#include <sys/spa.h> 37#include <sys/sa.h> 38#include <sys/sa_impl.h> 39#include <sys/zfs_context.h> 40#include <sys/trace_zfs.h> 41 42typedef void (*dmu_tx_hold_func_t)(dmu_tx_t *tx, struct dnode *dn, 43 uint64_t arg1, uint64_t arg2); 44 45dmu_tx_stats_t dmu_tx_stats = { 46 { "dmu_tx_assigned", KSTAT_DATA_UINT64 }, 47 { "dmu_tx_delay", KSTAT_DATA_UINT64 }, 48 { "dmu_tx_error", KSTAT_DATA_UINT64 }, 49 { "dmu_tx_suspended", KSTAT_DATA_UINT64 }, 50 { "dmu_tx_group", KSTAT_DATA_UINT64 }, 51 { "dmu_tx_memory_reserve", KSTAT_DATA_UINT64 }, 52 { "dmu_tx_memory_reclaim", KSTAT_DATA_UINT64 }, 53 { "dmu_tx_dirty_throttle", KSTAT_DATA_UINT64 }, 54 { "dmu_tx_dirty_delay", KSTAT_DATA_UINT64 }, 55 { "dmu_tx_dirty_over_max", KSTAT_DATA_UINT64 }, 56 { "dmu_tx_dirty_frees_delay", KSTAT_DATA_UINT64 }, 57 { "dmu_tx_wrlog_delay", KSTAT_DATA_UINT64 }, 58 { "dmu_tx_quota", KSTAT_DATA_UINT64 }, 59}; 60 61static kstat_t *dmu_tx_ksp; 62 63dmu_tx_t * 64dmu_tx_create_dd(dsl_dir_t *dd) 65{ 66 dmu_tx_t *tx = kmem_zalloc(sizeof (dmu_tx_t), KM_SLEEP); 67 tx->tx_dir = dd; 68 if (dd != NULL) 69 tx->tx_pool = dd->dd_pool; 70 list_create(&tx->tx_holds, sizeof (dmu_tx_hold_t), 71 offsetof(dmu_tx_hold_t, txh_node)); 72 list_create(&tx->tx_callbacks, sizeof (dmu_tx_callback_t), 73 offsetof(dmu_tx_callback_t, dcb_node)); 74 tx->tx_start = gethrtime(); 75 return (tx); 76} 77 78dmu_tx_t * 79dmu_tx_create(objset_t *os) 80{ 81 dmu_tx_t *tx = dmu_tx_create_dd(os->os_dsl_dataset->ds_dir); 82 tx->tx_objset = os; 83 return (tx); 84} 85 86dmu_tx_t * 87dmu_tx_create_assigned(struct dsl_pool *dp, uint64_t txg) 88{ 89 dmu_tx_t *tx = dmu_tx_create_dd(NULL); 90 91 TXG_VERIFY(dp->dp_spa, txg); 92 tx->tx_pool = dp; 93 tx->tx_txg = txg; 94 tx->tx_anyobj = TRUE; 95 96 return (tx); 97} 98 99int 100dmu_tx_is_syncing(dmu_tx_t *tx) 101{ 102 return (tx->tx_anyobj); 103} 104 105int 106dmu_tx_private_ok(dmu_tx_t *tx) 107{ 108 return (tx->tx_anyobj); 109} 110 111static dmu_tx_hold_t * 112dmu_tx_hold_dnode_impl(dmu_tx_t *tx, dnode_t *dn, enum dmu_tx_hold_type type, 113 uint64_t arg1, uint64_t arg2) 114{ 115 dmu_tx_hold_t *txh; 116 117 if (dn != NULL) { 118 (void) zfs_refcount_add(&dn->dn_holds, tx); 119 if (tx->tx_txg != 0) { 120 mutex_enter(&dn->dn_mtx); 121 /* 122 * dn->dn_assigned_txg == tx->tx_txg doesn't pose a 123 * problem, but there's no way for it to happen (for 124 * now, at least). 125 */ 126 ASSERT(dn->dn_assigned_txg == 0); 127 dn->dn_assigned_txg = tx->tx_txg; 128 (void) zfs_refcount_add(&dn->dn_tx_holds, tx); 129 mutex_exit(&dn->dn_mtx); 130 } 131 } 132 133 txh = kmem_zalloc(sizeof (dmu_tx_hold_t), KM_SLEEP); 134 txh->txh_tx = tx; 135 txh->txh_dnode = dn; 136 zfs_refcount_create(&txh->txh_space_towrite); 137 zfs_refcount_create(&txh->txh_memory_tohold); 138 txh->txh_type = type; 139 txh->txh_arg1 = arg1; 140 txh->txh_arg2 = arg2; 141 list_insert_tail(&tx->tx_holds, txh); 142 143 return (txh); 144} 145 146static dmu_tx_hold_t * 147dmu_tx_hold_object_impl(dmu_tx_t *tx, objset_t *os, uint64_t object, 148 enum dmu_tx_hold_type type, uint64_t arg1, uint64_t arg2) 149{ 150 dnode_t *dn = NULL; 151 dmu_tx_hold_t *txh; 152 int err; 153 154 if (object != DMU_NEW_OBJECT) { 155 err = dnode_hold(os, object, FTAG, &dn); 156 if (err != 0) { 157 tx->tx_err = err; 158 return (NULL); 159 } 160 } 161 txh = dmu_tx_hold_dnode_impl(tx, dn, type, arg1, arg2); 162 if (dn != NULL) 163 dnode_rele(dn, FTAG); 164 return (txh); 165} 166 167void 168dmu_tx_add_new_object(dmu_tx_t *tx, dnode_t *dn) 169{ 170 /* 171 * If we're syncing, they can manipulate any object anyhow, and 172 * the hold on the dnode_t can cause problems. 173 */ 174 if (!dmu_tx_is_syncing(tx)) 175 (void) dmu_tx_hold_dnode_impl(tx, dn, THT_NEWOBJECT, 0, 0); 176} 177 178/* 179 * This function reads specified data from disk. The specified data will 180 * be needed to perform the transaction -- i.e, it will be read after 181 * we do dmu_tx_assign(). There are two reasons that we read the data now 182 * (before dmu_tx_assign()): 183 * 184 * 1. Reading it now has potentially better performance. The transaction 185 * has not yet been assigned, so the TXG is not held open, and also the 186 * caller typically has less locks held when calling dmu_tx_hold_*() than 187 * after the transaction has been assigned. This reduces the lock (and txg) 188 * hold times, thus reducing lock contention. 189 * 190 * 2. It is easier for callers (primarily the ZPL) to handle i/o errors 191 * that are detected before they start making changes to the DMU state 192 * (i.e. now). Once the transaction has been assigned, and some DMU 193 * state has been changed, it can be difficult to recover from an i/o 194 * error (e.g. to undo the changes already made in memory at the DMU 195 * layer). Typically code to do so does not exist in the caller -- it 196 * assumes that the data has already been cached and thus i/o errors are 197 * not possible. 198 * 199 * It has been observed that the i/o initiated here can be a performance 200 * problem, and it appears to be optional, because we don't look at the 201 * data which is read. However, removing this read would only serve to 202 * move the work elsewhere (after the dmu_tx_assign()), where it may 203 * have a greater impact on performance (in addition to the impact on 204 * fault tolerance noted above). 205 */ 206static int 207dmu_tx_check_ioerr(zio_t *zio, dnode_t *dn, int level, uint64_t blkid) 208{ 209 int err; 210 dmu_buf_impl_t *db; 211 212 rw_enter(&dn->dn_struct_rwlock, RW_READER); 213 err = dbuf_hold_impl(dn, level, blkid, TRUE, FALSE, FTAG, &db); 214 rw_exit(&dn->dn_struct_rwlock); 215 if (err == ENOENT) 216 return (0); 217 if (err != 0) 218 return (err); 219 /* 220 * PARTIAL_FIRST allows caching for uncacheable blocks. It will 221 * be cleared after dmu_buf_will_dirty() call dbuf_read() again. 222 */ 223 err = dbuf_read(db, zio, DB_RF_CANFAIL | DB_RF_NOPREFETCH | 224 (level == 0 ? DB_RF_PARTIAL_FIRST : 0)); 225 dbuf_rele(db, FTAG); 226 return (err); 227} 228 229static void 230dmu_tx_count_write(dmu_tx_hold_t *txh, uint64_t off, uint64_t len) 231{ 232 dnode_t *dn = txh->txh_dnode; 233 int err = 0; 234 235 if (len == 0) 236 return; 237 238 (void) zfs_refcount_add_many(&txh->txh_space_towrite, len, FTAG); 239 240 if (dn == NULL) 241 return; 242 243 /* 244 * For i/o error checking, read the blocks that will be needed 245 * to perform the write: the first and last level-0 blocks (if 246 * they are not aligned, i.e. if they are partial-block writes), 247 * and all the level-1 blocks. 248 */ 249 if (dn->dn_maxblkid == 0) { 250 if (off < dn->dn_datablksz && 251 (off > 0 || len < dn->dn_datablksz)) { 252 err = dmu_tx_check_ioerr(NULL, dn, 0, 0); 253 if (err != 0) { 254 txh->txh_tx->tx_err = err; 255 } 256 } 257 } else { 258 zio_t *zio = zio_root(dn->dn_objset->os_spa, 259 NULL, NULL, ZIO_FLAG_CANFAIL); 260 261 /* first level-0 block */ 262 uint64_t start = off >> dn->dn_datablkshift; 263 if (P2PHASE(off, dn->dn_datablksz) || len < dn->dn_datablksz) { 264 err = dmu_tx_check_ioerr(zio, dn, 0, start); 265 if (err != 0) { 266 txh->txh_tx->tx_err = err; 267 } 268 } 269 270 /* last level-0 block */ 271 uint64_t end = (off + len - 1) >> dn->dn_datablkshift; 272 if (end != start && end <= dn->dn_maxblkid && 273 P2PHASE(off + len, dn->dn_datablksz)) { 274 err = dmu_tx_check_ioerr(zio, dn, 0, end); 275 if (err != 0) { 276 txh->txh_tx->tx_err = err; 277 } 278 } 279 280 /* level-1 blocks */ 281 if (dn->dn_nlevels > 1) { 282 int shft = dn->dn_indblkshift - SPA_BLKPTRSHIFT; 283 for (uint64_t i = (start >> shft) + 1; 284 i < end >> shft; i++) { 285 err = dmu_tx_check_ioerr(zio, dn, 1, i); 286 if (err != 0) { 287 txh->txh_tx->tx_err = err; 288 } 289 } 290 } 291 292 err = zio_wait(zio); 293 if (err != 0) { 294 txh->txh_tx->tx_err = err; 295 } 296 } 297} 298 299static void 300dmu_tx_count_append(dmu_tx_hold_t *txh, uint64_t off, uint64_t len) 301{ 302 dnode_t *dn = txh->txh_dnode; 303 int err = 0; 304 305 if (len == 0) 306 return; 307 308 (void) zfs_refcount_add_many(&txh->txh_space_towrite, len, FTAG); 309 310 if (dn == NULL) 311 return; 312 313 /* 314 * For i/o error checking, read the blocks that will be needed 315 * to perform the append; first level-0 block (if not aligned, i.e. 316 * if they are partial-block writes), no additional blocks are read. 317 */ 318 if (dn->dn_maxblkid == 0) { 319 if (off < dn->dn_datablksz && 320 (off > 0 || len < dn->dn_datablksz)) { 321 err = dmu_tx_check_ioerr(NULL, dn, 0, 0); 322 if (err != 0) { 323 txh->txh_tx->tx_err = err; 324 } 325 } 326 } else { 327 zio_t *zio = zio_root(dn->dn_objset->os_spa, 328 NULL, NULL, ZIO_FLAG_CANFAIL); 329 330 /* first level-0 block */ 331 uint64_t start = off >> dn->dn_datablkshift; 332 if (P2PHASE(off, dn->dn_datablksz) || len < dn->dn_datablksz) { 333 err = dmu_tx_check_ioerr(zio, dn, 0, start); 334 if (err != 0) { 335 txh->txh_tx->tx_err = err; 336 } 337 } 338 339 err = zio_wait(zio); 340 if (err != 0) { 341 txh->txh_tx->tx_err = err; 342 } 343 } 344} 345 346static void 347dmu_tx_count_dnode(dmu_tx_hold_t *txh) 348{ 349 (void) zfs_refcount_add_many(&txh->txh_space_towrite, 350 DNODE_MIN_SIZE, FTAG); 351} 352 353void 354dmu_tx_hold_write(dmu_tx_t *tx, uint64_t object, uint64_t off, int len) 355{ 356 dmu_tx_hold_t *txh; 357 358 ASSERT0(tx->tx_txg); 359 ASSERT3U(len, <=, DMU_MAX_ACCESS); 360 ASSERT(len == 0 || UINT64_MAX - off >= len - 1); 361 362 txh = dmu_tx_hold_object_impl(tx, tx->tx_objset, 363 object, THT_WRITE, off, len); 364 if (txh != NULL) { 365 dmu_tx_count_write(txh, off, len); 366 dmu_tx_count_dnode(txh); 367 } 368} 369 370void 371dmu_tx_hold_write_by_dnode(dmu_tx_t *tx, dnode_t *dn, uint64_t off, int len) 372{ 373 dmu_tx_hold_t *txh; 374 375 ASSERT0(tx->tx_txg); 376 ASSERT3U(len, <=, DMU_MAX_ACCESS); 377 ASSERT(len == 0 || UINT64_MAX - off >= len - 1); 378 379 txh = dmu_tx_hold_dnode_impl(tx, dn, THT_WRITE, off, len); 380 if (txh != NULL) { 381 dmu_tx_count_write(txh, off, len); 382 dmu_tx_count_dnode(txh); 383 } 384} 385 386/* 387 * Should be used when appending to an object and the exact offset is unknown. 388 * The write must occur at or beyond the specified offset. Only the L0 block 389 * at provided offset will be prefetched. 390 */ 391void 392dmu_tx_hold_append(dmu_tx_t *tx, uint64_t object, uint64_t off, int len) 393{ 394 dmu_tx_hold_t *txh; 395 396 ASSERT0(tx->tx_txg); 397 ASSERT3U(len, <=, DMU_MAX_ACCESS); 398 399 txh = dmu_tx_hold_object_impl(tx, tx->tx_objset, 400 object, THT_APPEND, off, DMU_OBJECT_END); 401 if (txh != NULL) { 402 dmu_tx_count_append(txh, off, len); 403 dmu_tx_count_dnode(txh); 404 } 405} 406 407void 408dmu_tx_hold_append_by_dnode(dmu_tx_t *tx, dnode_t *dn, uint64_t off, int len) 409{ 410 dmu_tx_hold_t *txh; 411 412 ASSERT0(tx->tx_txg); 413 ASSERT3U(len, <=, DMU_MAX_ACCESS); 414 415 txh = dmu_tx_hold_dnode_impl(tx, dn, THT_APPEND, off, DMU_OBJECT_END); 416 if (txh != NULL) { 417 dmu_tx_count_append(txh, off, len); 418 dmu_tx_count_dnode(txh); 419 } 420} 421 422/* 423 * This function marks the transaction as being a "net free". The end 424 * result is that refquotas will be disabled for this transaction, and 425 * this transaction will be able to use half of the pool space overhead 426 * (see dsl_pool_adjustedsize()). Therefore this function should only 427 * be called for transactions that we expect will not cause a net increase 428 * in the amount of space used (but it's OK if that is occasionally not true). 429 */ 430void 431dmu_tx_mark_netfree(dmu_tx_t *tx) 432{ 433 tx->tx_netfree = B_TRUE; 434} 435 436static void 437dmu_tx_count_free(dmu_tx_hold_t *txh, uint64_t off, uint64_t len) 438{ 439 dmu_tx_t *tx = txh->txh_tx; 440 dnode_t *dn = txh->txh_dnode; 441 int err; 442 443 ASSERT(tx->tx_txg == 0); 444 445 if (off >= (dn->dn_maxblkid + 1) * dn->dn_datablksz) 446 return; 447 if (len == DMU_OBJECT_END) 448 len = (dn->dn_maxblkid + 1) * dn->dn_datablksz - off; 449 450 /* 451 * For i/o error checking, we read the first and last level-0 452 * blocks if they are not aligned, and all the level-1 blocks. 453 * 454 * Note: dbuf_free_range() assumes that we have not instantiated 455 * any level-0 dbufs that will be completely freed. Therefore we must 456 * exercise care to not read or count the first and last blocks 457 * if they are blocksize-aligned. 458 */ 459 if (dn->dn_datablkshift == 0) { 460 if (off != 0 || len < dn->dn_datablksz) 461 dmu_tx_count_write(txh, 0, dn->dn_datablksz); 462 } else { 463 /* first block will be modified if it is not aligned */ 464 if (!IS_P2ALIGNED(off, 1 << dn->dn_datablkshift)) 465 dmu_tx_count_write(txh, off, 1); 466 /* last block will be modified if it is not aligned */ 467 if (!IS_P2ALIGNED(off + len, 1 << dn->dn_datablkshift)) 468 dmu_tx_count_write(txh, off + len, 1); 469 } 470 471 /* 472 * Check level-1 blocks. 473 */ 474 if (dn->dn_nlevels > 1) { 475 int shift = dn->dn_datablkshift + dn->dn_indblkshift - 476 SPA_BLKPTRSHIFT; 477 uint64_t start = off >> shift; 478 uint64_t end = (off + len) >> shift; 479 480 ASSERT(dn->dn_indblkshift != 0); 481 482 /* 483 * dnode_reallocate() can result in an object with indirect 484 * blocks having an odd data block size. In this case, 485 * just check the single block. 486 */ 487 if (dn->dn_datablkshift == 0) 488 start = end = 0; 489 490 zio_t *zio = zio_root(tx->tx_pool->dp_spa, 491 NULL, NULL, ZIO_FLAG_CANFAIL); 492 for (uint64_t i = start; i <= end; i++) { 493 uint64_t ibyte = i << shift; 494 err = dnode_next_offset(dn, 0, &ibyte, 2, 1, 0); 495 i = ibyte >> shift; 496 if (err == ESRCH || i > end) 497 break; 498 if (err != 0) { 499 tx->tx_err = err; 500 (void) zio_wait(zio); 501 return; 502 } 503 504 (void) zfs_refcount_add_many(&txh->txh_memory_tohold, 505 1 << dn->dn_indblkshift, FTAG); 506 507 err = dmu_tx_check_ioerr(zio, dn, 1, i); 508 if (err != 0) { 509 tx->tx_err = err; 510 (void) zio_wait(zio); 511 return; 512 } 513 } 514 err = zio_wait(zio); 515 if (err != 0) { 516 tx->tx_err = err; 517 return; 518 } 519 } 520} 521 522void 523dmu_tx_hold_free(dmu_tx_t *tx, uint64_t object, uint64_t off, uint64_t len) 524{ 525 dmu_tx_hold_t *txh; 526 527 txh = dmu_tx_hold_object_impl(tx, tx->tx_objset, 528 object, THT_FREE, off, len); 529 if (txh != NULL) { 530 dmu_tx_count_dnode(txh); 531 dmu_tx_count_free(txh, off, len); 532 } 533} 534 535void 536dmu_tx_hold_free_by_dnode(dmu_tx_t *tx, dnode_t *dn, uint64_t off, uint64_t len) 537{ 538 dmu_tx_hold_t *txh; 539 540 txh = dmu_tx_hold_dnode_impl(tx, dn, THT_FREE, off, len); 541 if (txh != NULL) { 542 dmu_tx_count_dnode(txh); 543 dmu_tx_count_free(txh, off, len); 544 } 545} 546 547static void 548dmu_tx_count_clone(dmu_tx_hold_t *txh, uint64_t off, uint64_t len) 549{ 550 551 /* 552 * Reuse dmu_tx_count_free(), it does exactly what we need for clone. 553 */ 554 dmu_tx_count_free(txh, off, len); 555} 556 557void 558dmu_tx_hold_clone_by_dnode(dmu_tx_t *tx, dnode_t *dn, uint64_t off, int len) 559{ 560 dmu_tx_hold_t *txh; 561 562 ASSERT0(tx->tx_txg); 563 ASSERT(len == 0 || UINT64_MAX - off >= len - 1); 564 565 txh = dmu_tx_hold_dnode_impl(tx, dn, THT_CLONE, off, len); 566 if (txh != NULL) { 567 dmu_tx_count_dnode(txh); 568 dmu_tx_count_clone(txh, off, len); 569 } 570} 571 572static void 573dmu_tx_hold_zap_impl(dmu_tx_hold_t *txh, const char *name) 574{ 575 dmu_tx_t *tx = txh->txh_tx; 576 dnode_t *dn = txh->txh_dnode; 577 int err; 578 extern int zap_micro_max_size; 579 580 ASSERT(tx->tx_txg == 0); 581 582 dmu_tx_count_dnode(txh); 583 584 /* 585 * Modifying a almost-full microzap is around the worst case (128KB) 586 * 587 * If it is a fat zap, the worst case would be 7*16KB=112KB: 588 * - 3 blocks overwritten: target leaf, ptrtbl block, header block 589 * - 4 new blocks written if adding: 590 * - 2 blocks for possibly split leaves, 591 * - 2 grown ptrtbl blocks 592 */ 593 (void) zfs_refcount_add_many(&txh->txh_space_towrite, 594 zap_micro_max_size, FTAG); 595 596 if (dn == NULL) 597 return; 598 599 ASSERT3U(DMU_OT_BYTESWAP(dn->dn_type), ==, DMU_BSWAP_ZAP); 600 601 if (dn->dn_maxblkid == 0 || name == NULL) { 602 /* 603 * This is a microzap (only one block), or we don't know 604 * the name. Check the first block for i/o errors. 605 */ 606 err = dmu_tx_check_ioerr(NULL, dn, 0, 0); 607 if (err != 0) { 608 tx->tx_err = err; 609 } 610 } else { 611 /* 612 * Access the name so that we'll check for i/o errors to 613 * the leaf blocks, etc. We ignore ENOENT, as this name 614 * may not yet exist. 615 */ 616 err = zap_lookup_by_dnode(dn, name, 8, 0, NULL); 617 if (err == EIO || err == ECKSUM || err == ENXIO) { 618 tx->tx_err = err; 619 } 620 } 621} 622 623void 624dmu_tx_hold_zap(dmu_tx_t *tx, uint64_t object, int add, const char *name) 625{ 626 dmu_tx_hold_t *txh; 627 628 ASSERT0(tx->tx_txg); 629 630 txh = dmu_tx_hold_object_impl(tx, tx->tx_objset, 631 object, THT_ZAP, add, (uintptr_t)name); 632 if (txh != NULL) 633 dmu_tx_hold_zap_impl(txh, name); 634} 635 636void 637dmu_tx_hold_zap_by_dnode(dmu_tx_t *tx, dnode_t *dn, int add, const char *name) 638{ 639 dmu_tx_hold_t *txh; 640 641 ASSERT0(tx->tx_txg); 642 ASSERT(dn != NULL); 643 644 txh = dmu_tx_hold_dnode_impl(tx, dn, THT_ZAP, add, (uintptr_t)name); 645 if (txh != NULL) 646 dmu_tx_hold_zap_impl(txh, name); 647} 648 649void 650dmu_tx_hold_bonus(dmu_tx_t *tx, uint64_t object) 651{ 652 dmu_tx_hold_t *txh; 653 654 ASSERT(tx->tx_txg == 0); 655 656 txh = dmu_tx_hold_object_impl(tx, tx->tx_objset, 657 object, THT_BONUS, 0, 0); 658 if (txh) 659 dmu_tx_count_dnode(txh); 660} 661 662void 663dmu_tx_hold_bonus_by_dnode(dmu_tx_t *tx, dnode_t *dn) 664{ 665 dmu_tx_hold_t *txh; 666 667 ASSERT0(tx->tx_txg); 668 669 txh = dmu_tx_hold_dnode_impl(tx, dn, THT_BONUS, 0, 0); 670 if (txh) 671 dmu_tx_count_dnode(txh); 672} 673 674void 675dmu_tx_hold_space(dmu_tx_t *tx, uint64_t space) 676{ 677 dmu_tx_hold_t *txh; 678 679 ASSERT(tx->tx_txg == 0); 680 681 txh = dmu_tx_hold_object_impl(tx, tx->tx_objset, 682 DMU_NEW_OBJECT, THT_SPACE, space, 0); 683 if (txh) { 684 (void) zfs_refcount_add_many( 685 &txh->txh_space_towrite, space, FTAG); 686 } 687} 688 689#ifdef ZFS_DEBUG 690void 691dmu_tx_dirty_buf(dmu_tx_t *tx, dmu_buf_impl_t *db) 692{ 693 boolean_t match_object = B_FALSE; 694 boolean_t match_offset = B_FALSE; 695 696 DB_DNODE_ENTER(db); 697 dnode_t *dn = DB_DNODE(db); 698 ASSERT(tx->tx_txg != 0); 699 ASSERT(tx->tx_objset == NULL || dn->dn_objset == tx->tx_objset); 700 ASSERT3U(dn->dn_object, ==, db->db.db_object); 701 702 if (tx->tx_anyobj) { 703 DB_DNODE_EXIT(db); 704 return; 705 } 706 707 /* XXX No checking on the meta dnode for now */ 708 if (db->db.db_object == DMU_META_DNODE_OBJECT) { 709 DB_DNODE_EXIT(db); 710 return; 711 } 712 713 for (dmu_tx_hold_t *txh = list_head(&tx->tx_holds); txh != NULL; 714 txh = list_next(&tx->tx_holds, txh)) { 715 ASSERT3U(dn->dn_assigned_txg, ==, tx->tx_txg); 716 if (txh->txh_dnode == dn && txh->txh_type != THT_NEWOBJECT) 717 match_object = TRUE; 718 if (txh->txh_dnode == NULL || txh->txh_dnode == dn) { 719 int datablkshift = dn->dn_datablkshift ? 720 dn->dn_datablkshift : SPA_MAXBLOCKSHIFT; 721 int epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT; 722 int shift = datablkshift + epbs * db->db_level; 723 uint64_t beginblk = shift >= 64 ? 0 : 724 (txh->txh_arg1 >> shift); 725 uint64_t endblk = shift >= 64 ? 0 : 726 ((txh->txh_arg1 + txh->txh_arg2 - 1) >> shift); 727 uint64_t blkid = db->db_blkid; 728 729 /* XXX txh_arg2 better not be zero... */ 730 731 dprintf("found txh type %x beginblk=%llx endblk=%llx\n", 732 txh->txh_type, (u_longlong_t)beginblk, 733 (u_longlong_t)endblk); 734 735 switch (txh->txh_type) { 736 case THT_WRITE: 737 if (blkid >= beginblk && blkid <= endblk) 738 match_offset = TRUE; 739 /* 740 * We will let this hold work for the bonus 741 * or spill buffer so that we don't need to 742 * hold it when creating a new object. 743 */ 744 if (blkid == DMU_BONUS_BLKID || 745 blkid == DMU_SPILL_BLKID) 746 match_offset = TRUE; 747 /* 748 * They might have to increase nlevels, 749 * thus dirtying the new TLIBs. Or the 750 * might have to change the block size, 751 * thus dirying the new lvl=0 blk=0. 752 */ 753 if (blkid == 0) 754 match_offset = TRUE; 755 break; 756 case THT_APPEND: 757 if (blkid >= beginblk && (blkid <= endblk || 758 txh->txh_arg2 == DMU_OBJECT_END)) 759 match_offset = TRUE; 760 761 /* 762 * THT_WRITE used for bonus and spill blocks. 763 */ 764 ASSERT(blkid != DMU_BONUS_BLKID && 765 blkid != DMU_SPILL_BLKID); 766 767 /* 768 * They might have to increase nlevels, 769 * thus dirtying the new TLIBs. Or the 770 * might have to change the block size, 771 * thus dirying the new lvl=0 blk=0. 772 */ 773 if (blkid == 0) 774 match_offset = TRUE; 775 break; 776 case THT_FREE: 777 /* 778 * We will dirty all the level 1 blocks in 779 * the free range and perhaps the first and 780 * last level 0 block. 781 */ 782 if (blkid >= beginblk && (blkid <= endblk || 783 txh->txh_arg2 == DMU_OBJECT_END)) 784 match_offset = TRUE; 785 break; 786 case THT_SPILL: 787 if (blkid == DMU_SPILL_BLKID) 788 match_offset = TRUE; 789 break; 790 case THT_BONUS: 791 if (blkid == DMU_BONUS_BLKID) 792 match_offset = TRUE; 793 break; 794 case THT_ZAP: 795 match_offset = TRUE; 796 break; 797 case THT_NEWOBJECT: 798 match_object = TRUE; 799 break; 800 case THT_CLONE: 801 if (blkid >= beginblk && blkid <= endblk) 802 match_offset = TRUE; 803 break; 804 default: 805 cmn_err(CE_PANIC, "bad txh_type %d", 806 txh->txh_type); 807 } 808 } 809 if (match_object && match_offset) { 810 DB_DNODE_EXIT(db); 811 return; 812 } 813 } 814 DB_DNODE_EXIT(db); 815 panic("dirtying dbuf obj=%llx lvl=%u blkid=%llx but not tx_held\n", 816 (u_longlong_t)db->db.db_object, db->db_level, 817 (u_longlong_t)db->db_blkid); 818} 819#endif 820 821/* 822 * If we can't do 10 iops, something is wrong. Let us go ahead 823 * and hit zfs_dirty_data_max. 824 */ 825static const hrtime_t zfs_delay_max_ns = 100 * MICROSEC; /* 100 milliseconds */ 826 827/* 828 * We delay transactions when we've determined that the backend storage 829 * isn't able to accommodate the rate of incoming writes. 830 * 831 * If there is already a transaction waiting, we delay relative to when 832 * that transaction finishes waiting. This way the calculated min_time 833 * is independent of the number of threads concurrently executing 834 * transactions. 835 * 836 * If we are the only waiter, wait relative to when the transaction 837 * started, rather than the current time. This credits the transaction for 838 * "time already served", e.g. reading indirect blocks. 839 * 840 * The minimum time for a transaction to take is calculated as: 841 * min_time = scale * (dirty - min) / (max - dirty) 842 * min_time is then capped at zfs_delay_max_ns. 843 * 844 * The delay has two degrees of freedom that can be adjusted via tunables. 845 * The percentage of dirty data at which we start to delay is defined by 846 * zfs_delay_min_dirty_percent. This should typically be at or above 847 * zfs_vdev_async_write_active_max_dirty_percent so that we only start to 848 * delay after writing at full speed has failed to keep up with the incoming 849 * write rate. The scale of the curve is defined by zfs_delay_scale. Roughly 850 * speaking, this variable determines the amount of delay at the midpoint of 851 * the curve. 852 * 853 * delay 854 * 10ms +-------------------------------------------------------------*+ 855 * | *| 856 * 9ms + *+ 857 * | *| 858 * 8ms + *+ 859 * | * | 860 * 7ms + * + 861 * | * | 862 * 6ms + * + 863 * | * | 864 * 5ms + * + 865 * | * | 866 * 4ms + * + 867 * | * | 868 * 3ms + * + 869 * | * | 870 * 2ms + (midpoint) * + 871 * | | ** | 872 * 1ms + v *** + 873 * | zfs_delay_scale ----------> ******** | 874 * 0 +-------------------------------------*********----------------+ 875 * 0% <- zfs_dirty_data_max -> 100% 876 * 877 * Note that since the delay is added to the outstanding time remaining on the 878 * most recent transaction, the delay is effectively the inverse of IOPS. 879 * Here the midpoint of 500us translates to 2000 IOPS. The shape of the curve 880 * was chosen such that small changes in the amount of accumulated dirty data 881 * in the first 3/4 of the curve yield relatively small differences in the 882 * amount of delay. 883 * 884 * The effects can be easier to understand when the amount of delay is 885 * represented on a log scale: 886 * 887 * delay 888 * 100ms +-------------------------------------------------------------++ 889 * + + 890 * | | 891 * + *+ 892 * 10ms + *+ 893 * + ** + 894 * | (midpoint) ** | 895 * + | ** + 896 * 1ms + v **** + 897 * + zfs_delay_scale ----------> ***** + 898 * | **** | 899 * + **** + 900 * 100us + ** + 901 * + * + 902 * | * | 903 * + * + 904 * 10us + * + 905 * + + 906 * | | 907 * + + 908 * +--------------------------------------------------------------+ 909 * 0% <- zfs_dirty_data_max -> 100% 910 * 911 * Note here that only as the amount of dirty data approaches its limit does 912 * the delay start to increase rapidly. The goal of a properly tuned system 913 * should be to keep the amount of dirty data out of that range by first 914 * ensuring that the appropriate limits are set for the I/O scheduler to reach 915 * optimal throughput on the backend storage, and then by changing the value 916 * of zfs_delay_scale to increase the steepness of the curve. 917 */ 918static void 919dmu_tx_delay(dmu_tx_t *tx, uint64_t dirty) 920{ 921 dsl_pool_t *dp = tx->tx_pool; 922 uint64_t delay_min_bytes, wrlog; 923 hrtime_t wakeup, tx_time = 0, now; 924 925 /* Calculate minimum transaction time for the dirty data amount. */ 926 delay_min_bytes = 927 zfs_dirty_data_max * zfs_delay_min_dirty_percent / 100; 928 if (dirty > delay_min_bytes) { 929 /* 930 * The caller has already waited until we are under the max. 931 * We make them pass us the amount of dirty data so we don't 932 * have to handle the case of it being >= the max, which 933 * could cause a divide-by-zero if it's == the max. 934 */ 935 ASSERT3U(dirty, <, zfs_dirty_data_max); 936 937 tx_time = zfs_delay_scale * (dirty - delay_min_bytes) / 938 (zfs_dirty_data_max - dirty); 939 } 940 941 /* Calculate minimum transaction time for the TX_WRITE log size. */ 942 wrlog = aggsum_upper_bound(&dp->dp_wrlog_total); 943 delay_min_bytes = 944 zfs_wrlog_data_max * zfs_delay_min_dirty_percent / 100; 945 if (wrlog >= zfs_wrlog_data_max) { 946 tx_time = zfs_delay_max_ns; 947 } else if (wrlog > delay_min_bytes) { 948 tx_time = MAX(zfs_delay_scale * (wrlog - delay_min_bytes) / 949 (zfs_wrlog_data_max - wrlog), tx_time); 950 } 951 952 if (tx_time == 0) 953 return; 954 955 tx_time = MIN(tx_time, zfs_delay_max_ns); 956 now = gethrtime(); 957 if (now > tx->tx_start + tx_time) 958 return; 959 960 DTRACE_PROBE3(delay__mintime, dmu_tx_t *, tx, uint64_t, dirty, 961 uint64_t, tx_time); 962 963 mutex_enter(&dp->dp_lock); 964 wakeup = MAX(tx->tx_start + tx_time, dp->dp_last_wakeup + tx_time); 965 dp->dp_last_wakeup = wakeup; 966 mutex_exit(&dp->dp_lock); 967 968 zfs_sleep_until(wakeup); 969} 970 971/* 972 * This routine attempts to assign the transaction to a transaction group. 973 * To do so, we must determine if there is sufficient free space on disk. 974 * 975 * If this is a "netfree" transaction (i.e. we called dmu_tx_mark_netfree() 976 * on it), then it is assumed that there is sufficient free space, 977 * unless there's insufficient slop space in the pool (see the comment 978 * above spa_slop_shift in spa_misc.c). 979 * 980 * If it is not a "netfree" transaction, then if the data already on disk 981 * is over the allowed usage (e.g. quota), this will fail with EDQUOT or 982 * ENOSPC. Otherwise, if the current rough estimate of pending changes, 983 * plus the rough estimate of this transaction's changes, may exceed the 984 * allowed usage, then this will fail with ERESTART, which will cause the 985 * caller to wait for the pending changes to be written to disk (by waiting 986 * for the next TXG to open), and then check the space usage again. 987 * 988 * The rough estimate of pending changes is comprised of the sum of: 989 * 990 * - this transaction's holds' txh_space_towrite 991 * 992 * - dd_tempreserved[], which is the sum of in-flight transactions' 993 * holds' txh_space_towrite (i.e. those transactions that have called 994 * dmu_tx_assign() but not yet called dmu_tx_commit()). 995 * 996 * - dd_space_towrite[], which is the amount of dirtied dbufs. 997 * 998 * Note that all of these values are inflated by spa_get_worst_case_asize(), 999 * which means that we may get ERESTART well before we are actually in danger 1000 * of running out of space, but this also mitigates any small inaccuracies 1001 * in the rough estimate (e.g. txh_space_towrite doesn't take into account 1002 * indirect blocks, and dd_space_towrite[] doesn't take into account changes 1003 * to the MOS). 1004 * 1005 * Note that due to this algorithm, it is possible to exceed the allowed 1006 * usage by one transaction. Also, as we approach the allowed usage, 1007 * we will allow a very limited amount of changes into each TXG, thus 1008 * decreasing performance. 1009 */ 1010static int 1011dmu_tx_try_assign(dmu_tx_t *tx, uint64_t txg_how) 1012{ 1013 spa_t *spa = tx->tx_pool->dp_spa; 1014 1015 ASSERT0(tx->tx_txg); 1016 1017 if (tx->tx_err) { 1018 DMU_TX_STAT_BUMP(dmu_tx_error); 1019 return (tx->tx_err); 1020 } 1021 1022 if (spa_suspended(spa)) { 1023 DMU_TX_STAT_BUMP(dmu_tx_suspended); 1024 1025 /* 1026 * If the user has indicated a blocking failure mode 1027 * then return ERESTART which will block in dmu_tx_wait(). 1028 * Otherwise, return EIO so that an error can get 1029 * propagated back to the VOP calls. 1030 * 1031 * Note that we always honor the txg_how flag regardless 1032 * of the failuremode setting. 1033 */ 1034 if (spa_get_failmode(spa) == ZIO_FAILURE_MODE_CONTINUE && 1035 !(txg_how & TXG_WAIT)) 1036 return (SET_ERROR(EIO)); 1037 1038 return (SET_ERROR(ERESTART)); 1039 } 1040 1041 if (!tx->tx_dirty_delayed && 1042 dsl_pool_need_wrlog_delay(tx->tx_pool)) { 1043 tx->tx_wait_dirty = B_TRUE; 1044 DMU_TX_STAT_BUMP(dmu_tx_wrlog_delay); 1045 return (SET_ERROR(ERESTART)); 1046 } 1047 1048 if (!tx->tx_dirty_delayed && 1049 dsl_pool_need_dirty_delay(tx->tx_pool)) { 1050 tx->tx_wait_dirty = B_TRUE; 1051 DMU_TX_STAT_BUMP(dmu_tx_dirty_delay); 1052 return (SET_ERROR(ERESTART)); 1053 } 1054 1055 tx->tx_txg = txg_hold_open(tx->tx_pool, &tx->tx_txgh); 1056 tx->tx_needassign_txh = NULL; 1057 1058 /* 1059 * NB: No error returns are allowed after txg_hold_open, but 1060 * before processing the dnode holds, due to the 1061 * dmu_tx_unassign() logic. 1062 */ 1063 1064 uint64_t towrite = 0; 1065 uint64_t tohold = 0; 1066 for (dmu_tx_hold_t *txh = list_head(&tx->tx_holds); txh != NULL; 1067 txh = list_next(&tx->tx_holds, txh)) { 1068 dnode_t *dn = txh->txh_dnode; 1069 if (dn != NULL) { 1070 /* 1071 * This thread can't hold the dn_struct_rwlock 1072 * while assigning the tx, because this can lead to 1073 * deadlock. Specifically, if this dnode is already 1074 * assigned to an earlier txg, this thread may need 1075 * to wait for that txg to sync (the ERESTART case 1076 * below). The other thread that has assigned this 1077 * dnode to an earlier txg prevents this txg from 1078 * syncing until its tx can complete (calling 1079 * dmu_tx_commit()), but it may need to acquire the 1080 * dn_struct_rwlock to do so (e.g. via 1081 * dmu_buf_hold*()). 1082 * 1083 * Note that this thread can't hold the lock for 1084 * read either, but the rwlock doesn't record 1085 * enough information to make that assertion. 1086 */ 1087 ASSERT(!RW_WRITE_HELD(&dn->dn_struct_rwlock)); 1088 1089 mutex_enter(&dn->dn_mtx); 1090 if (dn->dn_assigned_txg == tx->tx_txg - 1) { 1091 mutex_exit(&dn->dn_mtx); 1092 tx->tx_needassign_txh = txh; 1093 DMU_TX_STAT_BUMP(dmu_tx_group); 1094 return (SET_ERROR(ERESTART)); 1095 } 1096 if (dn->dn_assigned_txg == 0) 1097 dn->dn_assigned_txg = tx->tx_txg; 1098 ASSERT3U(dn->dn_assigned_txg, ==, tx->tx_txg); 1099 (void) zfs_refcount_add(&dn->dn_tx_holds, tx); 1100 mutex_exit(&dn->dn_mtx); 1101 } 1102 towrite += zfs_refcount_count(&txh->txh_space_towrite); 1103 tohold += zfs_refcount_count(&txh->txh_memory_tohold); 1104 } 1105 1106 /* needed allocation: worst-case estimate of write space */ 1107 uint64_t asize = spa_get_worst_case_asize(tx->tx_pool->dp_spa, towrite); 1108 /* calculate memory footprint estimate */ 1109 uint64_t memory = towrite + tohold; 1110 1111 if (tx->tx_dir != NULL && asize != 0) { 1112 int err = dsl_dir_tempreserve_space(tx->tx_dir, memory, 1113 asize, tx->tx_netfree, &tx->tx_tempreserve_cookie, tx); 1114 if (err != 0) 1115 return (err); 1116 } 1117 1118 DMU_TX_STAT_BUMP(dmu_tx_assigned); 1119 1120 return (0); 1121} 1122 1123static void 1124dmu_tx_unassign(dmu_tx_t *tx) 1125{ 1126 if (tx->tx_txg == 0) 1127 return; 1128 1129 txg_rele_to_quiesce(&tx->tx_txgh); 1130 1131 /* 1132 * Walk the transaction's hold list, removing the hold on the 1133 * associated dnode, and notifying waiters if the refcount drops to 0. 1134 */ 1135 for (dmu_tx_hold_t *txh = list_head(&tx->tx_holds); 1136 txh && txh != tx->tx_needassign_txh; 1137 txh = list_next(&tx->tx_holds, txh)) { 1138 dnode_t *dn = txh->txh_dnode; 1139 1140 if (dn == NULL) 1141 continue; 1142 mutex_enter(&dn->dn_mtx); 1143 ASSERT3U(dn->dn_assigned_txg, ==, tx->tx_txg); 1144 1145 if (zfs_refcount_remove(&dn->dn_tx_holds, tx) == 0) { 1146 dn->dn_assigned_txg = 0; 1147 cv_broadcast(&dn->dn_notxholds); 1148 } 1149 mutex_exit(&dn->dn_mtx); 1150 } 1151 1152 txg_rele_to_sync(&tx->tx_txgh); 1153 1154 tx->tx_lasttried_txg = tx->tx_txg; 1155 tx->tx_txg = 0; 1156} 1157 1158/* 1159 * Assign tx to a transaction group; txg_how is a bitmask: 1160 * 1161 * If TXG_WAIT is set and the currently open txg is full, this function 1162 * will wait until there's a new txg. This should be used when no locks 1163 * are being held. With this bit set, this function will only fail if 1164 * we're truly out of space (or over quota). 1165 * 1166 * If TXG_WAIT is *not* set and we can't assign into the currently open 1167 * txg without blocking, this function will return immediately with 1168 * ERESTART. This should be used whenever locks are being held. On an 1169 * ERESTART error, the caller should drop all locks, call dmu_tx_wait(), 1170 * and try again. 1171 * 1172 * If TXG_NOTHROTTLE is set, this indicates that this tx should not be 1173 * delayed due on the ZFS Write Throttle (see comments in dsl_pool.c for 1174 * details on the throttle). This is used by the VFS operations, after 1175 * they have already called dmu_tx_wait() (though most likely on a 1176 * different tx). 1177 * 1178 * It is guaranteed that subsequent successful calls to dmu_tx_assign() 1179 * will assign the tx to monotonically increasing txgs. Of course this is 1180 * not strong monotonicity, because the same txg can be returned multiple 1181 * times in a row. This guarantee holds both for subsequent calls from 1182 * one thread and for multiple threads. For example, it is impossible to 1183 * observe the following sequence of events: 1184 * 1185 * Thread 1 Thread 2 1186 * 1187 * dmu_tx_assign(T1, ...) 1188 * 1 <- dmu_tx_get_txg(T1) 1189 * dmu_tx_assign(T2, ...) 1190 * 2 <- dmu_tx_get_txg(T2) 1191 * dmu_tx_assign(T3, ...) 1192 * 1 <- dmu_tx_get_txg(T3) 1193 */ 1194int 1195dmu_tx_assign(dmu_tx_t *tx, uint64_t txg_how) 1196{ 1197 int err; 1198 1199 ASSERT(tx->tx_txg == 0); 1200 ASSERT0(txg_how & ~(TXG_WAIT | TXG_NOTHROTTLE)); 1201 ASSERT(!dsl_pool_sync_context(tx->tx_pool)); 1202 1203 /* If we might wait, we must not hold the config lock. */ 1204 IMPLY((txg_how & TXG_WAIT), !dsl_pool_config_held(tx->tx_pool)); 1205 1206 if ((txg_how & TXG_NOTHROTTLE)) 1207 tx->tx_dirty_delayed = B_TRUE; 1208 1209 while ((err = dmu_tx_try_assign(tx, txg_how)) != 0) { 1210 dmu_tx_unassign(tx); 1211 1212 if (err != ERESTART || !(txg_how & TXG_WAIT)) 1213 return (err); 1214 1215 dmu_tx_wait(tx); 1216 } 1217 1218 txg_rele_to_quiesce(&tx->tx_txgh); 1219 1220 return (0); 1221} 1222 1223void 1224dmu_tx_wait(dmu_tx_t *tx) 1225{ 1226 spa_t *spa = tx->tx_pool->dp_spa; 1227 dsl_pool_t *dp = tx->tx_pool; 1228 hrtime_t before; 1229 1230 ASSERT(tx->tx_txg == 0); 1231 ASSERT(!dsl_pool_config_held(tx->tx_pool)); 1232 1233 before = gethrtime(); 1234 1235 if (tx->tx_wait_dirty) { 1236 uint64_t dirty; 1237 1238 /* 1239 * dmu_tx_try_assign() has determined that we need to wait 1240 * because we've consumed much or all of the dirty buffer 1241 * space. 1242 */ 1243 mutex_enter(&dp->dp_lock); 1244 if (dp->dp_dirty_total >= zfs_dirty_data_max) 1245 DMU_TX_STAT_BUMP(dmu_tx_dirty_over_max); 1246 while (dp->dp_dirty_total >= zfs_dirty_data_max) 1247 cv_wait(&dp->dp_spaceavail_cv, &dp->dp_lock); 1248 dirty = dp->dp_dirty_total; 1249 mutex_exit(&dp->dp_lock); 1250 1251 dmu_tx_delay(tx, dirty); 1252 1253 tx->tx_wait_dirty = B_FALSE; 1254 1255 /* 1256 * Note: setting tx_dirty_delayed only has effect if the 1257 * caller used TX_WAIT. Otherwise they are going to 1258 * destroy this tx and try again. The common case, 1259 * zfs_write(), uses TX_WAIT. 1260 */ 1261 tx->tx_dirty_delayed = B_TRUE; 1262 } else if (spa_suspended(spa) || tx->tx_lasttried_txg == 0) { 1263 /* 1264 * If the pool is suspended we need to wait until it 1265 * is resumed. Note that it's possible that the pool 1266 * has become active after this thread has tried to 1267 * obtain a tx. If that's the case then tx_lasttried_txg 1268 * would not have been set. 1269 */ 1270 txg_wait_synced(dp, spa_last_synced_txg(spa) + 1); 1271 } else if (tx->tx_needassign_txh) { 1272 dnode_t *dn = tx->tx_needassign_txh->txh_dnode; 1273 1274 mutex_enter(&dn->dn_mtx); 1275 while (dn->dn_assigned_txg == tx->tx_lasttried_txg - 1) 1276 cv_wait(&dn->dn_notxholds, &dn->dn_mtx); 1277 mutex_exit(&dn->dn_mtx); 1278 tx->tx_needassign_txh = NULL; 1279 } else { 1280 /* 1281 * If we have a lot of dirty data just wait until we sync 1282 * out a TXG at which point we'll hopefully have synced 1283 * a portion of the changes. 1284 */ 1285 txg_wait_synced(dp, spa_last_synced_txg(spa) + 1); 1286 } 1287 1288 spa_tx_assign_add_nsecs(spa, gethrtime() - before); 1289} 1290 1291static void 1292dmu_tx_destroy(dmu_tx_t *tx) 1293{ 1294 dmu_tx_hold_t *txh; 1295 1296 while ((txh = list_head(&tx->tx_holds)) != NULL) { 1297 dnode_t *dn = txh->txh_dnode; 1298 1299 list_remove(&tx->tx_holds, txh); 1300 zfs_refcount_destroy_many(&txh->txh_space_towrite, 1301 zfs_refcount_count(&txh->txh_space_towrite)); 1302 zfs_refcount_destroy_many(&txh->txh_memory_tohold, 1303 zfs_refcount_count(&txh->txh_memory_tohold)); 1304 kmem_free(txh, sizeof (dmu_tx_hold_t)); 1305 if (dn != NULL) 1306 dnode_rele(dn, tx); 1307 } 1308 1309 list_destroy(&tx->tx_callbacks); 1310 list_destroy(&tx->tx_holds); 1311 kmem_free(tx, sizeof (dmu_tx_t)); 1312} 1313 1314void 1315dmu_tx_commit(dmu_tx_t *tx) 1316{ 1317 ASSERT(tx->tx_txg != 0); 1318 1319 /* 1320 * Go through the transaction's hold list and remove holds on 1321 * associated dnodes, notifying waiters if no holds remain. 1322 */ 1323 for (dmu_tx_hold_t *txh = list_head(&tx->tx_holds); txh != NULL; 1324 txh = list_next(&tx->tx_holds, txh)) { 1325 dnode_t *dn = txh->txh_dnode; 1326 1327 if (dn == NULL) 1328 continue; 1329 1330 mutex_enter(&dn->dn_mtx); 1331 ASSERT3U(dn->dn_assigned_txg, ==, tx->tx_txg); 1332 1333 if (zfs_refcount_remove(&dn->dn_tx_holds, tx) == 0) { 1334 dn->dn_assigned_txg = 0; 1335 cv_broadcast(&dn->dn_notxholds); 1336 } 1337 mutex_exit(&dn->dn_mtx); 1338 } 1339 1340 if (tx->tx_tempreserve_cookie) 1341 dsl_dir_tempreserve_clear(tx->tx_tempreserve_cookie, tx); 1342 1343 if (!list_is_empty(&tx->tx_callbacks)) 1344 txg_register_callbacks(&tx->tx_txgh, &tx->tx_callbacks); 1345 1346 if (tx->tx_anyobj == FALSE) 1347 txg_rele_to_sync(&tx->tx_txgh); 1348 1349 dmu_tx_destroy(tx); 1350} 1351 1352void 1353dmu_tx_abort(dmu_tx_t *tx) 1354{ 1355 ASSERT(tx->tx_txg == 0); 1356 1357 /* 1358 * Call any registered callbacks with an error code. 1359 */ 1360 if (!list_is_empty(&tx->tx_callbacks)) 1361 dmu_tx_do_callbacks(&tx->tx_callbacks, SET_ERROR(ECANCELED)); 1362 1363 dmu_tx_destroy(tx); 1364} 1365 1366uint64_t 1367dmu_tx_get_txg(dmu_tx_t *tx) 1368{ 1369 ASSERT(tx->tx_txg != 0); 1370 return (tx->tx_txg); 1371} 1372 1373dsl_pool_t * 1374dmu_tx_pool(dmu_tx_t *tx) 1375{ 1376 ASSERT(tx->tx_pool != NULL); 1377 return (tx->tx_pool); 1378} 1379 1380void 1381dmu_tx_callback_register(dmu_tx_t *tx, dmu_tx_callback_func_t *func, void *data) 1382{ 1383 dmu_tx_callback_t *dcb; 1384 1385 dcb = kmem_alloc(sizeof (dmu_tx_callback_t), KM_SLEEP); 1386 1387 dcb->dcb_func = func; 1388 dcb->dcb_data = data; 1389 1390 list_insert_tail(&tx->tx_callbacks, dcb); 1391} 1392 1393/* 1394 * Call all the commit callbacks on a list, with a given error code. 1395 */ 1396void 1397dmu_tx_do_callbacks(list_t *cb_list, int error) 1398{ 1399 dmu_tx_callback_t *dcb; 1400 1401 while ((dcb = list_remove_tail(cb_list)) != NULL) { 1402 dcb->dcb_func(dcb->dcb_data, error); 1403 kmem_free(dcb, sizeof (dmu_tx_callback_t)); 1404 } 1405} 1406 1407/* 1408 * Interface to hold a bunch of attributes. 1409 * used for creating new files. 1410 * attrsize is the total size of all attributes 1411 * to be added during object creation 1412 * 1413 * For updating/adding a single attribute dmu_tx_hold_sa() should be used. 1414 */ 1415 1416/* 1417 * hold necessary attribute name for attribute registration. 1418 * should be a very rare case where this is needed. If it does 1419 * happen it would only happen on the first write to the file system. 1420 */ 1421static void 1422dmu_tx_sa_registration_hold(sa_os_t *sa, dmu_tx_t *tx) 1423{ 1424 if (!sa->sa_need_attr_registration) 1425 return; 1426 1427 for (int i = 0; i != sa->sa_num_attrs; i++) { 1428 if (!sa->sa_attr_table[i].sa_registered) { 1429 if (sa->sa_reg_attr_obj) 1430 dmu_tx_hold_zap(tx, sa->sa_reg_attr_obj, 1431 B_TRUE, sa->sa_attr_table[i].sa_name); 1432 else 1433 dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, 1434 B_TRUE, sa->sa_attr_table[i].sa_name); 1435 } 1436 } 1437} 1438 1439void 1440dmu_tx_hold_spill(dmu_tx_t *tx, uint64_t object) 1441{ 1442 dmu_tx_hold_t *txh; 1443 1444 txh = dmu_tx_hold_object_impl(tx, tx->tx_objset, object, 1445 THT_SPILL, 0, 0); 1446 if (txh != NULL) 1447 (void) zfs_refcount_add_many(&txh->txh_space_towrite, 1448 SPA_OLD_MAXBLOCKSIZE, FTAG); 1449} 1450 1451void 1452dmu_tx_hold_sa_create(dmu_tx_t *tx, int attrsize) 1453{ 1454 sa_os_t *sa = tx->tx_objset->os_sa; 1455 1456 dmu_tx_hold_bonus(tx, DMU_NEW_OBJECT); 1457 1458 if (tx->tx_objset->os_sa->sa_master_obj == 0) 1459 return; 1460 1461 if (tx->tx_objset->os_sa->sa_layout_attr_obj) { 1462 dmu_tx_hold_zap(tx, sa->sa_layout_attr_obj, B_TRUE, NULL); 1463 } else { 1464 dmu_tx_hold_zap(tx, sa->sa_master_obj, B_TRUE, SA_LAYOUTS); 1465 dmu_tx_hold_zap(tx, sa->sa_master_obj, B_TRUE, SA_REGISTRY); 1466 dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, B_TRUE, NULL); 1467 dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, B_TRUE, NULL); 1468 } 1469 1470 dmu_tx_sa_registration_hold(sa, tx); 1471 1472 if (attrsize <= DN_OLD_MAX_BONUSLEN && !sa->sa_force_spill) 1473 return; 1474 1475 (void) dmu_tx_hold_object_impl(tx, tx->tx_objset, DMU_NEW_OBJECT, 1476 THT_SPILL, 0, 0); 1477} 1478 1479/* 1480 * Hold SA attribute 1481 * 1482 * dmu_tx_hold_sa(dmu_tx_t *tx, sa_handle_t *, attribute, add, size) 1483 * 1484 * variable_size is the total size of all variable sized attributes 1485 * passed to this function. It is not the total size of all 1486 * variable size attributes that *may* exist on this object. 1487 */ 1488void 1489dmu_tx_hold_sa(dmu_tx_t *tx, sa_handle_t *hdl, boolean_t may_grow) 1490{ 1491 uint64_t object; 1492 sa_os_t *sa = tx->tx_objset->os_sa; 1493 1494 ASSERT(hdl != NULL); 1495 1496 object = sa_handle_object(hdl); 1497 1498 dmu_buf_impl_t *db = (dmu_buf_impl_t *)hdl->sa_bonus; 1499 DB_DNODE_ENTER(db); 1500 dmu_tx_hold_bonus_by_dnode(tx, DB_DNODE(db)); 1501 DB_DNODE_EXIT(db); 1502 1503 if (tx->tx_objset->os_sa->sa_master_obj == 0) 1504 return; 1505 1506 if (tx->tx_objset->os_sa->sa_reg_attr_obj == 0 || 1507 tx->tx_objset->os_sa->sa_layout_attr_obj == 0) { 1508 dmu_tx_hold_zap(tx, sa->sa_master_obj, B_TRUE, SA_LAYOUTS); 1509 dmu_tx_hold_zap(tx, sa->sa_master_obj, B_TRUE, SA_REGISTRY); 1510 dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, B_TRUE, NULL); 1511 dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, B_TRUE, NULL); 1512 } 1513 1514 dmu_tx_sa_registration_hold(sa, tx); 1515 1516 if (may_grow && tx->tx_objset->os_sa->sa_layout_attr_obj) 1517 dmu_tx_hold_zap(tx, sa->sa_layout_attr_obj, B_TRUE, NULL); 1518 1519 if (sa->sa_force_spill || may_grow || hdl->sa_spill) { 1520 ASSERT(tx->tx_txg == 0); 1521 dmu_tx_hold_spill(tx, object); 1522 } else { 1523 dnode_t *dn; 1524 1525 DB_DNODE_ENTER(db); 1526 dn = DB_DNODE(db); 1527 if (dn->dn_have_spill) { 1528 ASSERT(tx->tx_txg == 0); 1529 dmu_tx_hold_spill(tx, object); 1530 } 1531 DB_DNODE_EXIT(db); 1532 } 1533} 1534 1535void 1536dmu_tx_init(void) 1537{ 1538 dmu_tx_ksp = kstat_create("zfs", 0, "dmu_tx", "misc", 1539 KSTAT_TYPE_NAMED, sizeof (dmu_tx_stats) / sizeof (kstat_named_t), 1540 KSTAT_FLAG_VIRTUAL); 1541 1542 if (dmu_tx_ksp != NULL) { 1543 dmu_tx_ksp->ks_data = &dmu_tx_stats; 1544 kstat_install(dmu_tx_ksp); 1545 } 1546} 1547 1548void 1549dmu_tx_fini(void) 1550{ 1551 if (dmu_tx_ksp != NULL) { 1552 kstat_delete(dmu_tx_ksp); 1553 dmu_tx_ksp = NULL; 1554 } 1555} 1556 1557#if defined(_KERNEL) 1558EXPORT_SYMBOL(dmu_tx_create); 1559EXPORT_SYMBOL(dmu_tx_hold_write); 1560EXPORT_SYMBOL(dmu_tx_hold_write_by_dnode); 1561EXPORT_SYMBOL(dmu_tx_hold_append); 1562EXPORT_SYMBOL(dmu_tx_hold_append_by_dnode); 1563EXPORT_SYMBOL(dmu_tx_hold_free); 1564EXPORT_SYMBOL(dmu_tx_hold_free_by_dnode); 1565EXPORT_SYMBOL(dmu_tx_hold_zap); 1566EXPORT_SYMBOL(dmu_tx_hold_zap_by_dnode); 1567EXPORT_SYMBOL(dmu_tx_hold_bonus); 1568EXPORT_SYMBOL(dmu_tx_hold_bonus_by_dnode); 1569EXPORT_SYMBOL(dmu_tx_abort); 1570EXPORT_SYMBOL(dmu_tx_assign); 1571EXPORT_SYMBOL(dmu_tx_wait); 1572EXPORT_SYMBOL(dmu_tx_commit); 1573EXPORT_SYMBOL(dmu_tx_mark_netfree); 1574EXPORT_SYMBOL(dmu_tx_get_txg); 1575EXPORT_SYMBOL(dmu_tx_callback_register); 1576EXPORT_SYMBOL(dmu_tx_do_callbacks); 1577EXPORT_SYMBOL(dmu_tx_hold_spill); 1578EXPORT_SYMBOL(dmu_tx_hold_sa_create); 1579EXPORT_SYMBOL(dmu_tx_hold_sa); 1580#endif 1581