dmu_tx.c revision 277585
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, 2014 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> /* for dsl_dataset_block_freeable() */ 33#include <sys/dsl_dir.h> /* for dsl_dir_tempreserve_*() */ 34#include <sys/dsl_pool.h> 35#include <sys/zap_impl.h> /* for fzap_default_block_shift */ 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/varargs.h> 41 42typedef void (*dmu_tx_hold_func_t)(dmu_tx_t *tx, struct dnode *dn, 43 uint64_t arg1, uint64_t arg2); 44 45 46dmu_tx_t * 47dmu_tx_create_dd(dsl_dir_t *dd) 48{ 49 dmu_tx_t *tx = kmem_zalloc(sizeof (dmu_tx_t), KM_SLEEP); 50 tx->tx_dir = dd; 51 if (dd != NULL) 52 tx->tx_pool = dd->dd_pool; 53 list_create(&tx->tx_holds, sizeof (dmu_tx_hold_t), 54 offsetof(dmu_tx_hold_t, txh_node)); 55 list_create(&tx->tx_callbacks, sizeof (dmu_tx_callback_t), 56 offsetof(dmu_tx_callback_t, dcb_node)); 57 tx->tx_start = gethrtime(); 58#ifdef ZFS_DEBUG 59 refcount_create(&tx->tx_space_written); 60 refcount_create(&tx->tx_space_freed); 61#endif 62 return (tx); 63} 64 65dmu_tx_t * 66dmu_tx_create(objset_t *os) 67{ 68 dmu_tx_t *tx = dmu_tx_create_dd(os->os_dsl_dataset->ds_dir); 69 tx->tx_objset = os; 70 tx->tx_lastsnap_txg = dsl_dataset_prev_snap_txg(os->os_dsl_dataset); 71 return (tx); 72} 73 74dmu_tx_t * 75dmu_tx_create_assigned(struct dsl_pool *dp, uint64_t txg) 76{ 77 dmu_tx_t *tx = dmu_tx_create_dd(NULL); 78 79 ASSERT3U(txg, <=, dp->dp_tx.tx_open_txg); 80 tx->tx_pool = dp; 81 tx->tx_txg = txg; 82 tx->tx_anyobj = TRUE; 83 84 return (tx); 85} 86 87int 88dmu_tx_is_syncing(dmu_tx_t *tx) 89{ 90 return (tx->tx_anyobj); 91} 92 93int 94dmu_tx_private_ok(dmu_tx_t *tx) 95{ 96 return (tx->tx_anyobj); 97} 98 99static dmu_tx_hold_t * 100dmu_tx_hold_object_impl(dmu_tx_t *tx, objset_t *os, uint64_t object, 101 enum dmu_tx_hold_type type, uint64_t arg1, uint64_t arg2) 102{ 103 dmu_tx_hold_t *txh; 104 dnode_t *dn = NULL; 105 int err; 106 107 if (object != DMU_NEW_OBJECT) { 108 err = dnode_hold(os, object, tx, &dn); 109 if (err) { 110 tx->tx_err = err; 111 return (NULL); 112 } 113 114 if (err == 0 && tx->tx_txg != 0) { 115 mutex_enter(&dn->dn_mtx); 116 /* 117 * dn->dn_assigned_txg == tx->tx_txg doesn't pose a 118 * problem, but there's no way for it to happen (for 119 * now, at least). 120 */ 121 ASSERT(dn->dn_assigned_txg == 0); 122 dn->dn_assigned_txg = tx->tx_txg; 123 (void) refcount_add(&dn->dn_tx_holds, tx); 124 mutex_exit(&dn->dn_mtx); 125 } 126 } 127 128 txh = kmem_zalloc(sizeof (dmu_tx_hold_t), KM_SLEEP); 129 txh->txh_tx = tx; 130 txh->txh_dnode = dn; 131#ifdef ZFS_DEBUG 132 txh->txh_type = type; 133 txh->txh_arg1 = arg1; 134 txh->txh_arg2 = arg2; 135#endif 136 list_insert_tail(&tx->tx_holds, txh); 137 138 return (txh); 139} 140 141void 142dmu_tx_add_new_object(dmu_tx_t *tx, objset_t *os, uint64_t object) 143{ 144 /* 145 * If we're syncing, they can manipulate any object anyhow, and 146 * the hold on the dnode_t can cause problems. 147 */ 148 if (!dmu_tx_is_syncing(tx)) { 149 (void) dmu_tx_hold_object_impl(tx, os, 150 object, THT_NEWOBJECT, 0, 0); 151 } 152} 153 154static int 155dmu_tx_check_ioerr(zio_t *zio, dnode_t *dn, int level, uint64_t blkid) 156{ 157 int err; 158 dmu_buf_impl_t *db; 159 160 rw_enter(&dn->dn_struct_rwlock, RW_READER); 161 db = dbuf_hold_level(dn, level, blkid, FTAG); 162 rw_exit(&dn->dn_struct_rwlock); 163 if (db == NULL) 164 return (SET_ERROR(EIO)); 165 err = dbuf_read(db, zio, DB_RF_CANFAIL | DB_RF_NOPREFETCH); 166 dbuf_rele(db, FTAG); 167 return (err); 168} 169 170static void 171dmu_tx_count_twig(dmu_tx_hold_t *txh, dnode_t *dn, dmu_buf_impl_t *db, 172 int level, uint64_t blkid, boolean_t freeable, uint64_t *history) 173{ 174 objset_t *os = dn->dn_objset; 175 dsl_dataset_t *ds = os->os_dsl_dataset; 176 int epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT; 177 dmu_buf_impl_t *parent = NULL; 178 blkptr_t *bp = NULL; 179 uint64_t space; 180 181 if (level >= dn->dn_nlevels || history[level] == blkid) 182 return; 183 184 history[level] = blkid; 185 186 space = (level == 0) ? dn->dn_datablksz : (1ULL << dn->dn_indblkshift); 187 188 if (db == NULL || db == dn->dn_dbuf) { 189 ASSERT(level != 0); 190 db = NULL; 191 } else { 192 ASSERT(DB_DNODE(db) == dn); 193 ASSERT(db->db_level == level); 194 ASSERT(db->db.db_size == space); 195 ASSERT(db->db_blkid == blkid); 196 bp = db->db_blkptr; 197 parent = db->db_parent; 198 } 199 200 freeable = (bp && (freeable || 201 dsl_dataset_block_freeable(ds, bp, bp->blk_birth))); 202 203 if (freeable) 204 txh->txh_space_tooverwrite += space; 205 else 206 txh->txh_space_towrite += space; 207 if (bp) 208 txh->txh_space_tounref += bp_get_dsize(os->os_spa, bp); 209 210 dmu_tx_count_twig(txh, dn, parent, level + 1, 211 blkid >> epbs, freeable, history); 212} 213 214/* ARGSUSED */ 215static void 216dmu_tx_count_write(dmu_tx_hold_t *txh, uint64_t off, uint64_t len) 217{ 218 dnode_t *dn = txh->txh_dnode; 219 uint64_t start, end, i; 220 int min_bs, max_bs, min_ibs, max_ibs, epbs, bits; 221 int err = 0; 222 223 if (len == 0) 224 return; 225 226 min_bs = SPA_MINBLOCKSHIFT; 227 max_bs = highbit64(txh->txh_tx->tx_objset->os_recordsize) - 1; 228 min_ibs = DN_MIN_INDBLKSHIFT; 229 max_ibs = DN_MAX_INDBLKSHIFT; 230 231 if (dn) { 232 uint64_t history[DN_MAX_LEVELS]; 233 int nlvls = dn->dn_nlevels; 234 int delta; 235 236 /* 237 * For i/o error checking, read the first and last level-0 238 * blocks (if they are not aligned), and all the level-1 blocks. 239 */ 240 if (dn->dn_maxblkid == 0) { 241 delta = dn->dn_datablksz; 242 start = (off < dn->dn_datablksz) ? 0 : 1; 243 end = (off+len <= dn->dn_datablksz) ? 0 : 1; 244 if (start == 0 && (off > 0 || len < dn->dn_datablksz)) { 245 err = dmu_tx_check_ioerr(NULL, dn, 0, 0); 246 if (err) 247 goto out; 248 delta -= off; 249 } 250 } else { 251 zio_t *zio = zio_root(dn->dn_objset->os_spa, 252 NULL, NULL, ZIO_FLAG_CANFAIL); 253 254 /* first level-0 block */ 255 start = off >> dn->dn_datablkshift; 256 if (P2PHASE(off, dn->dn_datablksz) || 257 len < dn->dn_datablksz) { 258 err = dmu_tx_check_ioerr(zio, dn, 0, start); 259 if (err) 260 goto out; 261 } 262 263 /* last level-0 block */ 264 end = (off+len-1) >> dn->dn_datablkshift; 265 if (end != start && end <= dn->dn_maxblkid && 266 P2PHASE(off+len, dn->dn_datablksz)) { 267 err = dmu_tx_check_ioerr(zio, dn, 0, end); 268 if (err) 269 goto out; 270 } 271 272 /* level-1 blocks */ 273 if (nlvls > 1) { 274 int shft = dn->dn_indblkshift - SPA_BLKPTRSHIFT; 275 for (i = (start>>shft)+1; i < end>>shft; i++) { 276 err = dmu_tx_check_ioerr(zio, dn, 1, i); 277 if (err) 278 goto out; 279 } 280 } 281 282 err = zio_wait(zio); 283 if (err) 284 goto out; 285 delta = P2NPHASE(off, dn->dn_datablksz); 286 } 287 288 min_ibs = max_ibs = dn->dn_indblkshift; 289 if (dn->dn_maxblkid > 0) { 290 /* 291 * The blocksize can't change, 292 * so we can make a more precise estimate. 293 */ 294 ASSERT(dn->dn_datablkshift != 0); 295 min_bs = max_bs = dn->dn_datablkshift; 296 } else { 297 /* 298 * The blocksize can increase up to the recordsize, 299 * or if it is already more than the recordsize, 300 * up to the next power of 2. 301 */ 302 min_bs = highbit64(dn->dn_datablksz - 1); 303 max_bs = MAX(max_bs, highbit64(dn->dn_datablksz - 1)); 304 } 305 306 /* 307 * If this write is not off the end of the file 308 * we need to account for overwrites/unref. 309 */ 310 if (start <= dn->dn_maxblkid) { 311 for (int l = 0; l < DN_MAX_LEVELS; l++) 312 history[l] = -1ULL; 313 } 314 while (start <= dn->dn_maxblkid) { 315 dmu_buf_impl_t *db; 316 317 rw_enter(&dn->dn_struct_rwlock, RW_READER); 318 err = dbuf_hold_impl(dn, 0, start, FALSE, FTAG, &db); 319 rw_exit(&dn->dn_struct_rwlock); 320 321 if (err) { 322 txh->txh_tx->tx_err = err; 323 return; 324 } 325 326 dmu_tx_count_twig(txh, dn, db, 0, start, B_FALSE, 327 history); 328 dbuf_rele(db, FTAG); 329 if (++start > end) { 330 /* 331 * Account for new indirects appearing 332 * before this IO gets assigned into a txg. 333 */ 334 bits = 64 - min_bs; 335 epbs = min_ibs - SPA_BLKPTRSHIFT; 336 for (bits -= epbs * (nlvls - 1); 337 bits >= 0; bits -= epbs) 338 txh->txh_fudge += 1ULL << max_ibs; 339 goto out; 340 } 341 off += delta; 342 if (len >= delta) 343 len -= delta; 344 delta = dn->dn_datablksz; 345 } 346 } 347 348 /* 349 * 'end' is the last thing we will access, not one past. 350 * This way we won't overflow when accessing the last byte. 351 */ 352 start = P2ALIGN(off, 1ULL << max_bs); 353 end = P2ROUNDUP(off + len, 1ULL << max_bs) - 1; 354 txh->txh_space_towrite += end - start + 1; 355 356 start >>= min_bs; 357 end >>= min_bs; 358 359 epbs = min_ibs - SPA_BLKPTRSHIFT; 360 361 /* 362 * The object contains at most 2^(64 - min_bs) blocks, 363 * and each indirect level maps 2^epbs. 364 */ 365 for (bits = 64 - min_bs; bits >= 0; bits -= epbs) { 366 start >>= epbs; 367 end >>= epbs; 368 ASSERT3U(end, >=, start); 369 txh->txh_space_towrite += (end - start + 1) << max_ibs; 370 if (start != 0) { 371 /* 372 * We also need a new blkid=0 indirect block 373 * to reference any existing file data. 374 */ 375 txh->txh_space_towrite += 1ULL << max_ibs; 376 } 377 } 378 379out: 380 if (txh->txh_space_towrite + txh->txh_space_tooverwrite > 381 2 * DMU_MAX_ACCESS) 382 err = SET_ERROR(EFBIG); 383 384 if (err) 385 txh->txh_tx->tx_err = err; 386} 387 388static void 389dmu_tx_count_dnode(dmu_tx_hold_t *txh) 390{ 391 dnode_t *dn = txh->txh_dnode; 392 dnode_t *mdn = DMU_META_DNODE(txh->txh_tx->tx_objset); 393 uint64_t space = mdn->dn_datablksz + 394 ((mdn->dn_nlevels-1) << mdn->dn_indblkshift); 395 396 if (dn && dn->dn_dbuf->db_blkptr && 397 dsl_dataset_block_freeable(dn->dn_objset->os_dsl_dataset, 398 dn->dn_dbuf->db_blkptr, dn->dn_dbuf->db_blkptr->blk_birth)) { 399 txh->txh_space_tooverwrite += space; 400 txh->txh_space_tounref += space; 401 } else { 402 txh->txh_space_towrite += space; 403 if (dn && dn->dn_dbuf->db_blkptr) 404 txh->txh_space_tounref += space; 405 } 406} 407 408void 409dmu_tx_hold_write(dmu_tx_t *tx, uint64_t object, uint64_t off, int len) 410{ 411 dmu_tx_hold_t *txh; 412 413 ASSERT(tx->tx_txg == 0); 414 ASSERT(len < DMU_MAX_ACCESS); 415 ASSERT(len == 0 || UINT64_MAX - off >= len - 1); 416 417 txh = dmu_tx_hold_object_impl(tx, tx->tx_objset, 418 object, THT_WRITE, off, len); 419 if (txh == NULL) 420 return; 421 422 dmu_tx_count_write(txh, off, len); 423 dmu_tx_count_dnode(txh); 424} 425 426static void 427dmu_tx_count_free(dmu_tx_hold_t *txh, uint64_t off, uint64_t len) 428{ 429 uint64_t blkid, nblks, lastblk; 430 uint64_t space = 0, unref = 0, skipped = 0; 431 dnode_t *dn = txh->txh_dnode; 432 dsl_dataset_t *ds = dn->dn_objset->os_dsl_dataset; 433 spa_t *spa = txh->txh_tx->tx_pool->dp_spa; 434 int epbs; 435 uint64_t l0span = 0, nl1blks = 0; 436 437 if (dn->dn_nlevels == 0) 438 return; 439 440 /* 441 * The struct_rwlock protects us against dn_nlevels 442 * changing, in case (against all odds) we manage to dirty & 443 * sync out the changes after we check for being dirty. 444 * Also, dbuf_hold_impl() wants us to have the struct_rwlock. 445 */ 446 rw_enter(&dn->dn_struct_rwlock, RW_READER); 447 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT; 448 if (dn->dn_maxblkid == 0) { 449 if (off == 0 && len >= dn->dn_datablksz) { 450 blkid = 0; 451 nblks = 1; 452 } else { 453 rw_exit(&dn->dn_struct_rwlock); 454 return; 455 } 456 } else { 457 blkid = off >> dn->dn_datablkshift; 458 nblks = (len + dn->dn_datablksz - 1) >> dn->dn_datablkshift; 459 460 if (blkid > dn->dn_maxblkid) { 461 rw_exit(&dn->dn_struct_rwlock); 462 return; 463 } 464 if (blkid + nblks > dn->dn_maxblkid) 465 nblks = dn->dn_maxblkid - blkid + 1; 466 467 } 468 l0span = nblks; /* save for later use to calc level > 1 overhead */ 469 if (dn->dn_nlevels == 1) { 470 int i; 471 for (i = 0; i < nblks; i++) { 472 blkptr_t *bp = dn->dn_phys->dn_blkptr; 473 ASSERT3U(blkid + i, <, dn->dn_nblkptr); 474 bp += blkid + i; 475 if (dsl_dataset_block_freeable(ds, bp, bp->blk_birth)) { 476 dprintf_bp(bp, "can free old%s", ""); 477 space += bp_get_dsize(spa, bp); 478 } 479 unref += BP_GET_ASIZE(bp); 480 } 481 nl1blks = 1; 482 nblks = 0; 483 } 484 485 lastblk = blkid + nblks - 1; 486 while (nblks) { 487 dmu_buf_impl_t *dbuf; 488 uint64_t ibyte, new_blkid; 489 int epb = 1 << epbs; 490 int err, i, blkoff, tochk; 491 blkptr_t *bp; 492 493 ibyte = blkid << dn->dn_datablkshift; 494 err = dnode_next_offset(dn, 495 DNODE_FIND_HAVELOCK, &ibyte, 2, 1, 0); 496 new_blkid = ibyte >> dn->dn_datablkshift; 497 if (err == ESRCH) { 498 skipped += (lastblk >> epbs) - (blkid >> epbs) + 1; 499 break; 500 } 501 if (err) { 502 txh->txh_tx->tx_err = err; 503 break; 504 } 505 if (new_blkid > lastblk) { 506 skipped += (lastblk >> epbs) - (blkid >> epbs) + 1; 507 break; 508 } 509 510 if (new_blkid > blkid) { 511 ASSERT((new_blkid >> epbs) > (blkid >> epbs)); 512 skipped += (new_blkid >> epbs) - (blkid >> epbs) - 1; 513 nblks -= new_blkid - blkid; 514 blkid = new_blkid; 515 } 516 blkoff = P2PHASE(blkid, epb); 517 tochk = MIN(epb - blkoff, nblks); 518 519 err = dbuf_hold_impl(dn, 1, blkid >> epbs, FALSE, FTAG, &dbuf); 520 if (err) { 521 txh->txh_tx->tx_err = err; 522 break; 523 } 524 525 txh->txh_memory_tohold += dbuf->db.db_size; 526 527 /* 528 * We don't check memory_tohold against DMU_MAX_ACCESS because 529 * memory_tohold is an over-estimation (especially the >L1 530 * indirect blocks), so it could fail. Callers should have 531 * already verified that they will not be holding too much 532 * memory. 533 */ 534 535 err = dbuf_read(dbuf, NULL, DB_RF_HAVESTRUCT | DB_RF_CANFAIL); 536 if (err != 0) { 537 txh->txh_tx->tx_err = err; 538 dbuf_rele(dbuf, FTAG); 539 break; 540 } 541 542 bp = dbuf->db.db_data; 543 bp += blkoff; 544 545 for (i = 0; i < tochk; i++) { 546 if (dsl_dataset_block_freeable(ds, &bp[i], 547 bp[i].blk_birth)) { 548 dprintf_bp(&bp[i], "can free old%s", ""); 549 space += bp_get_dsize(spa, &bp[i]); 550 } 551 unref += BP_GET_ASIZE(bp); 552 } 553 dbuf_rele(dbuf, FTAG); 554 555 ++nl1blks; 556 blkid += tochk; 557 nblks -= tochk; 558 } 559 rw_exit(&dn->dn_struct_rwlock); 560 561 /* 562 * Add in memory requirements of higher-level indirects. 563 * This assumes a worst-possible scenario for dn_nlevels and a 564 * worst-possible distribution of l1-blocks over the region to free. 565 */ 566 { 567 uint64_t blkcnt = 1 + ((l0span >> epbs) >> epbs); 568 int level = 2; 569 /* 570 * Here we don't use DN_MAX_LEVEL, but calculate it with the 571 * given datablkshift and indblkshift. This makes the 572 * difference between 19 and 8 on large files. 573 */ 574 int maxlevel = 2 + (DN_MAX_OFFSET_SHIFT - dn->dn_datablkshift) / 575 (dn->dn_indblkshift - SPA_BLKPTRSHIFT); 576 577 while (level++ < maxlevel) { 578 txh->txh_memory_tohold += MAX(MIN(blkcnt, nl1blks), 1) 579 << dn->dn_indblkshift; 580 blkcnt = 1 + (blkcnt >> epbs); 581 } 582 } 583 584 /* account for new level 1 indirect blocks that might show up */ 585 if (skipped > 0) { 586 txh->txh_fudge += skipped << dn->dn_indblkshift; 587 skipped = MIN(skipped, DMU_MAX_DELETEBLKCNT >> epbs); 588 txh->txh_memory_tohold += skipped << dn->dn_indblkshift; 589 } 590 txh->txh_space_tofree += space; 591 txh->txh_space_tounref += unref; 592} 593 594/* 595 * This function marks the transaction as being a "net free". The end 596 * result is that refquotas will be disabled for this transaction, and 597 * this transaction will be able to use half of the pool space overhead 598 * (see dsl_pool_adjustedsize()). Therefore this function should only 599 * be called for transactions that we expect will not cause a net increase 600 * in the amount of space used (but it's OK if that is occasionally not true). 601 */ 602void 603dmu_tx_mark_netfree(dmu_tx_t *tx) 604{ 605 dmu_tx_hold_t *txh; 606 607 txh = dmu_tx_hold_object_impl(tx, tx->tx_objset, 608 DMU_NEW_OBJECT, THT_FREE, 0, 0); 609 610 /* 611 * Pretend that this operation will free 1GB of space. This 612 * should be large enough to cancel out the largest write. 613 * We don't want to use something like UINT64_MAX, because that would 614 * cause overflows when doing math with these values (e.g. in 615 * dmu_tx_try_assign()). 616 */ 617 txh->txh_space_tofree = txh->txh_space_tounref = 1024 * 1024 * 1024; 618} 619 620void 621dmu_tx_hold_free(dmu_tx_t *tx, uint64_t object, uint64_t off, uint64_t len) 622{ 623 dmu_tx_hold_t *txh; 624 dnode_t *dn; 625 int err; 626 zio_t *zio; 627 628 ASSERT(tx->tx_txg == 0); 629 630 txh = dmu_tx_hold_object_impl(tx, tx->tx_objset, 631 object, THT_FREE, off, len); 632 if (txh == NULL) 633 return; 634 dn = txh->txh_dnode; 635 dmu_tx_count_dnode(txh); 636 637 if (off >= (dn->dn_maxblkid+1) * dn->dn_datablksz) 638 return; 639 if (len == DMU_OBJECT_END) 640 len = (dn->dn_maxblkid+1) * dn->dn_datablksz - off; 641 642 643 /* 644 * For i/o error checking, we read the first and last level-0 645 * blocks if they are not aligned, and all the level-1 blocks. 646 * 647 * Note: dbuf_free_range() assumes that we have not instantiated 648 * any level-0 dbufs that will be completely freed. Therefore we must 649 * exercise care to not read or count the first and last blocks 650 * if they are blocksize-aligned. 651 */ 652 if (dn->dn_datablkshift == 0) { 653 if (off != 0 || len < dn->dn_datablksz) 654 dmu_tx_count_write(txh, 0, dn->dn_datablksz); 655 } else { 656 /* first block will be modified if it is not aligned */ 657 if (!IS_P2ALIGNED(off, 1 << dn->dn_datablkshift)) 658 dmu_tx_count_write(txh, off, 1); 659 /* last block will be modified if it is not aligned */ 660 if (!IS_P2ALIGNED(off + len, 1 << dn->dn_datablkshift)) 661 dmu_tx_count_write(txh, off+len, 1); 662 } 663 664 /* 665 * Check level-1 blocks. 666 */ 667 if (dn->dn_nlevels > 1) { 668 int shift = dn->dn_datablkshift + dn->dn_indblkshift - 669 SPA_BLKPTRSHIFT; 670 uint64_t start = off >> shift; 671 uint64_t end = (off + len) >> shift; 672 673 ASSERT(dn->dn_indblkshift != 0); 674 675 /* 676 * dnode_reallocate() can result in an object with indirect 677 * blocks having an odd data block size. In this case, 678 * just check the single block. 679 */ 680 if (dn->dn_datablkshift == 0) 681 start = end = 0; 682 683 zio = zio_root(tx->tx_pool->dp_spa, 684 NULL, NULL, ZIO_FLAG_CANFAIL); 685 for (uint64_t i = start; i <= end; i++) { 686 uint64_t ibyte = i << shift; 687 err = dnode_next_offset(dn, 0, &ibyte, 2, 1, 0); 688 i = ibyte >> shift; 689 if (err == ESRCH) 690 break; 691 if (err) { 692 tx->tx_err = err; 693 return; 694 } 695 696 err = dmu_tx_check_ioerr(zio, dn, 1, i); 697 if (err) { 698 tx->tx_err = err; 699 return; 700 } 701 } 702 err = zio_wait(zio); 703 if (err) { 704 tx->tx_err = err; 705 return; 706 } 707 } 708 709 dmu_tx_count_free(txh, off, len); 710} 711 712void 713dmu_tx_hold_zap(dmu_tx_t *tx, uint64_t object, int add, const char *name) 714{ 715 dmu_tx_hold_t *txh; 716 dnode_t *dn; 717 dsl_dataset_phys_t *ds_phys; 718 uint64_t nblocks; 719 int epbs, err; 720 721 ASSERT(tx->tx_txg == 0); 722 723 txh = dmu_tx_hold_object_impl(tx, tx->tx_objset, 724 object, THT_ZAP, add, (uintptr_t)name); 725 if (txh == NULL) 726 return; 727 dn = txh->txh_dnode; 728 729 dmu_tx_count_dnode(txh); 730 731 if (dn == NULL) { 732 /* 733 * We will be able to fit a new object's entries into one leaf 734 * block. So there will be at most 2 blocks total, 735 * including the header block. 736 */ 737 dmu_tx_count_write(txh, 0, 2 << fzap_default_block_shift); 738 return; 739 } 740 741 ASSERT3P(DMU_OT_BYTESWAP(dn->dn_type), ==, DMU_BSWAP_ZAP); 742 743 if (dn->dn_maxblkid == 0 && !add) { 744 blkptr_t *bp; 745 746 /* 747 * If there is only one block (i.e. this is a micro-zap) 748 * and we are not adding anything, the accounting is simple. 749 */ 750 err = dmu_tx_check_ioerr(NULL, dn, 0, 0); 751 if (err) { 752 tx->tx_err = err; 753 return; 754 } 755 756 /* 757 * Use max block size here, since we don't know how much 758 * the size will change between now and the dbuf dirty call. 759 */ 760 bp = &dn->dn_phys->dn_blkptr[0]; 761 if (dsl_dataset_block_freeable(dn->dn_objset->os_dsl_dataset, 762 bp, bp->blk_birth)) 763 txh->txh_space_tooverwrite += MZAP_MAX_BLKSZ; 764 else 765 txh->txh_space_towrite += MZAP_MAX_BLKSZ; 766 if (!BP_IS_HOLE(bp)) 767 txh->txh_space_tounref += MZAP_MAX_BLKSZ; 768 return; 769 } 770 771 if (dn->dn_maxblkid > 0 && name) { 772 /* 773 * access the name in this fat-zap so that we'll check 774 * for i/o errors to the leaf blocks, etc. 775 */ 776 err = zap_lookup(dn->dn_objset, dn->dn_object, name, 777 8, 0, NULL); 778 if (err == EIO) { 779 tx->tx_err = err; 780 return; 781 } 782 } 783 784 err = zap_count_write(dn->dn_objset, dn->dn_object, name, add, 785 &txh->txh_space_towrite, &txh->txh_space_tooverwrite); 786 787 /* 788 * If the modified blocks are scattered to the four winds, 789 * we'll have to modify an indirect twig for each. 790 */ 791 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT; 792 ds_phys = dsl_dataset_phys(dn->dn_objset->os_dsl_dataset); 793 for (nblocks = dn->dn_maxblkid >> epbs; nblocks != 0; nblocks >>= epbs) 794 if (ds_phys->ds_prev_snap_obj) 795 txh->txh_space_towrite += 3 << dn->dn_indblkshift; 796 else 797 txh->txh_space_tooverwrite += 3 << dn->dn_indblkshift; 798} 799 800void 801dmu_tx_hold_bonus(dmu_tx_t *tx, uint64_t object) 802{ 803 dmu_tx_hold_t *txh; 804 805 ASSERT(tx->tx_txg == 0); 806 807 txh = dmu_tx_hold_object_impl(tx, tx->tx_objset, 808 object, THT_BONUS, 0, 0); 809 if (txh) 810 dmu_tx_count_dnode(txh); 811} 812 813void 814dmu_tx_hold_space(dmu_tx_t *tx, uint64_t space) 815{ 816 dmu_tx_hold_t *txh; 817 ASSERT(tx->tx_txg == 0); 818 819 txh = dmu_tx_hold_object_impl(tx, tx->tx_objset, 820 DMU_NEW_OBJECT, THT_SPACE, space, 0); 821 822 txh->txh_space_towrite += space; 823} 824 825int 826dmu_tx_holds(dmu_tx_t *tx, uint64_t object) 827{ 828 dmu_tx_hold_t *txh; 829 int holds = 0; 830 831 /* 832 * By asserting that the tx is assigned, we're counting the 833 * number of dn_tx_holds, which is the same as the number of 834 * dn_holds. Otherwise, we'd be counting dn_holds, but 835 * dn_tx_holds could be 0. 836 */ 837 ASSERT(tx->tx_txg != 0); 838 839 /* if (tx->tx_anyobj == TRUE) */ 840 /* return (0); */ 841 842 for (txh = list_head(&tx->tx_holds); txh; 843 txh = list_next(&tx->tx_holds, txh)) { 844 if (txh->txh_dnode && txh->txh_dnode->dn_object == object) 845 holds++; 846 } 847 848 return (holds); 849} 850 851#ifdef ZFS_DEBUG 852void 853dmu_tx_dirty_buf(dmu_tx_t *tx, dmu_buf_impl_t *db) 854{ 855 dmu_tx_hold_t *txh; 856 int match_object = FALSE, match_offset = FALSE; 857 dnode_t *dn; 858 859 DB_DNODE_ENTER(db); 860 dn = DB_DNODE(db); 861 ASSERT(tx->tx_txg != 0); 862 ASSERT(tx->tx_objset == NULL || dn->dn_objset == tx->tx_objset); 863 ASSERT3U(dn->dn_object, ==, db->db.db_object); 864 865 if (tx->tx_anyobj) { 866 DB_DNODE_EXIT(db); 867 return; 868 } 869 870 /* XXX No checking on the meta dnode for now */ 871 if (db->db.db_object == DMU_META_DNODE_OBJECT) { 872 DB_DNODE_EXIT(db); 873 return; 874 } 875 876 for (txh = list_head(&tx->tx_holds); txh; 877 txh = list_next(&tx->tx_holds, txh)) { 878 ASSERT(dn == NULL || dn->dn_assigned_txg == tx->tx_txg); 879 if (txh->txh_dnode == dn && txh->txh_type != THT_NEWOBJECT) 880 match_object = TRUE; 881 if (txh->txh_dnode == NULL || txh->txh_dnode == dn) { 882 int datablkshift = dn->dn_datablkshift ? 883 dn->dn_datablkshift : SPA_MAXBLOCKSHIFT; 884 int epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT; 885 int shift = datablkshift + epbs * db->db_level; 886 uint64_t beginblk = shift >= 64 ? 0 : 887 (txh->txh_arg1 >> shift); 888 uint64_t endblk = shift >= 64 ? 0 : 889 ((txh->txh_arg1 + txh->txh_arg2 - 1) >> shift); 890 uint64_t blkid = db->db_blkid; 891 892 /* XXX txh_arg2 better not be zero... */ 893 894 dprintf("found txh type %x beginblk=%llx endblk=%llx\n", 895 txh->txh_type, beginblk, endblk); 896 897 switch (txh->txh_type) { 898 case THT_WRITE: 899 if (blkid >= beginblk && blkid <= endblk) 900 match_offset = TRUE; 901 /* 902 * We will let this hold work for the bonus 903 * or spill buffer so that we don't need to 904 * hold it when creating a new object. 905 */ 906 if (blkid == DMU_BONUS_BLKID || 907 blkid == DMU_SPILL_BLKID) 908 match_offset = TRUE; 909 /* 910 * They might have to increase nlevels, 911 * thus dirtying the new TLIBs. Or the 912 * might have to change the block size, 913 * thus dirying the new lvl=0 blk=0. 914 */ 915 if (blkid == 0) 916 match_offset = TRUE; 917 break; 918 case THT_FREE: 919 /* 920 * We will dirty all the level 1 blocks in 921 * the free range and perhaps the first and 922 * last level 0 block. 923 */ 924 if (blkid >= beginblk && (blkid <= endblk || 925 txh->txh_arg2 == DMU_OBJECT_END)) 926 match_offset = TRUE; 927 break; 928 case THT_SPILL: 929 if (blkid == DMU_SPILL_BLKID) 930 match_offset = TRUE; 931 break; 932 case THT_BONUS: 933 if (blkid == DMU_BONUS_BLKID) 934 match_offset = TRUE; 935 break; 936 case THT_ZAP: 937 match_offset = TRUE; 938 break; 939 case THT_NEWOBJECT: 940 match_object = TRUE; 941 break; 942 default: 943 ASSERT(!"bad txh_type"); 944 } 945 } 946 if (match_object && match_offset) { 947 DB_DNODE_EXIT(db); 948 return; 949 } 950 } 951 DB_DNODE_EXIT(db); 952 panic("dirtying dbuf obj=%llx lvl=%u blkid=%llx but not tx_held\n", 953 (u_longlong_t)db->db.db_object, db->db_level, 954 (u_longlong_t)db->db_blkid); 955} 956#endif 957 958/* 959 * If we can't do 10 iops, something is wrong. Let us go ahead 960 * and hit zfs_dirty_data_max. 961 */ 962hrtime_t zfs_delay_max_ns = MSEC2NSEC(100); 963int zfs_delay_resolution_ns = 100 * 1000; /* 100 microseconds */ 964 965/* 966 * We delay transactions when we've determined that the backend storage 967 * isn't able to accommodate the rate of incoming writes. 968 * 969 * If there is already a transaction waiting, we delay relative to when 970 * that transaction finishes waiting. This way the calculated min_time 971 * is independent of the number of threads concurrently executing 972 * transactions. 973 * 974 * If we are the only waiter, wait relative to when the transaction 975 * started, rather than the current time. This credits the transaction for 976 * "time already served", e.g. reading indirect blocks. 977 * 978 * The minimum time for a transaction to take is calculated as: 979 * min_time = scale * (dirty - min) / (max - dirty) 980 * min_time is then capped at zfs_delay_max_ns. 981 * 982 * The delay has two degrees of freedom that can be adjusted via tunables. 983 * The percentage of dirty data at which we start to delay is defined by 984 * zfs_delay_min_dirty_percent. This should typically be at or above 985 * zfs_vdev_async_write_active_max_dirty_percent so that we only start to 986 * delay after writing at full speed has failed to keep up with the incoming 987 * write rate. The scale of the curve is defined by zfs_delay_scale. Roughly 988 * speaking, this variable determines the amount of delay at the midpoint of 989 * the curve. 990 * 991 * delay 992 * 10ms +-------------------------------------------------------------*+ 993 * | *| 994 * 9ms + *+ 995 * | *| 996 * 8ms + *+ 997 * | * | 998 * 7ms + * + 999 * | * | 1000 * 6ms + * + 1001 * | * | 1002 * 5ms + * + 1003 * | * | 1004 * 4ms + * + 1005 * | * | 1006 * 3ms + * + 1007 * | * | 1008 * 2ms + (midpoint) * + 1009 * | | ** | 1010 * 1ms + v *** + 1011 * | zfs_delay_scale ----------> ******** | 1012 * 0 +-------------------------------------*********----------------+ 1013 * 0% <- zfs_dirty_data_max -> 100% 1014 * 1015 * Note that since the delay is added to the outstanding time remaining on the 1016 * most recent transaction, the delay is effectively the inverse of IOPS. 1017 * Here the midpoint of 500us translates to 2000 IOPS. The shape of the curve 1018 * was chosen such that small changes in the amount of accumulated dirty data 1019 * in the first 3/4 of the curve yield relatively small differences in the 1020 * amount of delay. 1021 * 1022 * The effects can be easier to understand when the amount of delay is 1023 * represented on a log scale: 1024 * 1025 * delay 1026 * 100ms +-------------------------------------------------------------++ 1027 * + + 1028 * | | 1029 * + *+ 1030 * 10ms + *+ 1031 * + ** + 1032 * | (midpoint) ** | 1033 * + | ** + 1034 * 1ms + v **** + 1035 * + zfs_delay_scale ----------> ***** + 1036 * | **** | 1037 * + **** + 1038 * 100us + ** + 1039 * + * + 1040 * | * | 1041 * + * + 1042 * 10us + * + 1043 * + + 1044 * | | 1045 * + + 1046 * +--------------------------------------------------------------+ 1047 * 0% <- zfs_dirty_data_max -> 100% 1048 * 1049 * Note here that only as the amount of dirty data approaches its limit does 1050 * the delay start to increase rapidly. The goal of a properly tuned system 1051 * should be to keep the amount of dirty data out of that range by first 1052 * ensuring that the appropriate limits are set for the I/O scheduler to reach 1053 * optimal throughput on the backend storage, and then by changing the value 1054 * of zfs_delay_scale to increase the steepness of the curve. 1055 */ 1056static void 1057dmu_tx_delay(dmu_tx_t *tx, uint64_t dirty) 1058{ 1059 dsl_pool_t *dp = tx->tx_pool; 1060 uint64_t delay_min_bytes = 1061 zfs_dirty_data_max * zfs_delay_min_dirty_percent / 100; 1062 hrtime_t wakeup, min_tx_time, now; 1063 1064 if (dirty <= delay_min_bytes) 1065 return; 1066 1067 /* 1068 * The caller has already waited until we are under the max. 1069 * We make them pass us the amount of dirty data so we don't 1070 * have to handle the case of it being >= the max, which could 1071 * cause a divide-by-zero if it's == the max. 1072 */ 1073 ASSERT3U(dirty, <, zfs_dirty_data_max); 1074 1075 now = gethrtime(); 1076 min_tx_time = zfs_delay_scale * 1077 (dirty - delay_min_bytes) / (zfs_dirty_data_max - dirty); 1078 if (now > tx->tx_start + min_tx_time) 1079 return; 1080 1081 min_tx_time = MIN(min_tx_time, zfs_delay_max_ns); 1082 1083 DTRACE_PROBE3(delay__mintime, dmu_tx_t *, tx, uint64_t, dirty, 1084 uint64_t, min_tx_time); 1085 1086 mutex_enter(&dp->dp_lock); 1087 wakeup = MAX(tx->tx_start + min_tx_time, 1088 dp->dp_last_wakeup + min_tx_time); 1089 dp->dp_last_wakeup = wakeup; 1090 mutex_exit(&dp->dp_lock); 1091 1092#ifdef _KERNEL 1093#ifdef illumos 1094 mutex_enter(&curthread->t_delay_lock); 1095 while (cv_timedwait_hires(&curthread->t_delay_cv, 1096 &curthread->t_delay_lock, wakeup, zfs_delay_resolution_ns, 1097 CALLOUT_FLAG_ABSOLUTE | CALLOUT_FLAG_ROUNDUP) > 0) 1098 continue; 1099 mutex_exit(&curthread->t_delay_lock); 1100#else 1101 pause_sbt("dmu_tx_delay", wakeup * SBT_1NS, 1102 zfs_delay_resolution_ns * SBT_1NS, C_ABSOLUTE); 1103#endif 1104#else 1105 hrtime_t delta = wakeup - gethrtime(); 1106 struct timespec ts; 1107 ts.tv_sec = delta / NANOSEC; 1108 ts.tv_nsec = delta % NANOSEC; 1109 (void) nanosleep(&ts, NULL); 1110#endif 1111} 1112 1113static int 1114dmu_tx_try_assign(dmu_tx_t *tx, txg_how_t txg_how) 1115{ 1116 dmu_tx_hold_t *txh; 1117 spa_t *spa = tx->tx_pool->dp_spa; 1118 uint64_t memory, asize, fsize, usize; 1119 uint64_t towrite, tofree, tooverwrite, tounref, tohold, fudge; 1120 1121 ASSERT0(tx->tx_txg); 1122 1123 if (tx->tx_err) 1124 return (tx->tx_err); 1125 1126 if (spa_suspended(spa)) { 1127 /* 1128 * If the user has indicated a blocking failure mode 1129 * then return ERESTART which will block in dmu_tx_wait(). 1130 * Otherwise, return EIO so that an error can get 1131 * propagated back to the VOP calls. 1132 * 1133 * Note that we always honor the txg_how flag regardless 1134 * of the failuremode setting. 1135 */ 1136 if (spa_get_failmode(spa) == ZIO_FAILURE_MODE_CONTINUE && 1137 txg_how != TXG_WAIT) 1138 return (SET_ERROR(EIO)); 1139 1140 return (SET_ERROR(ERESTART)); 1141 } 1142 1143 if (!tx->tx_waited && 1144 dsl_pool_need_dirty_delay(tx->tx_pool)) { 1145 tx->tx_wait_dirty = B_TRUE; 1146 return (SET_ERROR(ERESTART)); 1147 } 1148 1149 tx->tx_txg = txg_hold_open(tx->tx_pool, &tx->tx_txgh); 1150 tx->tx_needassign_txh = NULL; 1151 1152 /* 1153 * NB: No error returns are allowed after txg_hold_open, but 1154 * before processing the dnode holds, due to the 1155 * dmu_tx_unassign() logic. 1156 */ 1157 1158 towrite = tofree = tooverwrite = tounref = tohold = fudge = 0; 1159 for (txh = list_head(&tx->tx_holds); txh; 1160 txh = list_next(&tx->tx_holds, txh)) { 1161 dnode_t *dn = txh->txh_dnode; 1162 if (dn != NULL) { 1163 mutex_enter(&dn->dn_mtx); 1164 if (dn->dn_assigned_txg == tx->tx_txg - 1) { 1165 mutex_exit(&dn->dn_mtx); 1166 tx->tx_needassign_txh = txh; 1167 return (SET_ERROR(ERESTART)); 1168 } 1169 if (dn->dn_assigned_txg == 0) 1170 dn->dn_assigned_txg = tx->tx_txg; 1171 ASSERT3U(dn->dn_assigned_txg, ==, tx->tx_txg); 1172 (void) refcount_add(&dn->dn_tx_holds, tx); 1173 mutex_exit(&dn->dn_mtx); 1174 } 1175 towrite += txh->txh_space_towrite; 1176 tofree += txh->txh_space_tofree; 1177 tooverwrite += txh->txh_space_tooverwrite; 1178 tounref += txh->txh_space_tounref; 1179 tohold += txh->txh_memory_tohold; 1180 fudge += txh->txh_fudge; 1181 } 1182 1183 /* 1184 * If a snapshot has been taken since we made our estimates, 1185 * assume that we won't be able to free or overwrite anything. 1186 */ 1187 if (tx->tx_objset && 1188 dsl_dataset_prev_snap_txg(tx->tx_objset->os_dsl_dataset) > 1189 tx->tx_lastsnap_txg) { 1190 towrite += tooverwrite; 1191 tooverwrite = tofree = 0; 1192 } 1193 1194 /* needed allocation: worst-case estimate of write space */ 1195 asize = spa_get_asize(tx->tx_pool->dp_spa, towrite + tooverwrite); 1196 /* freed space estimate: worst-case overwrite + free estimate */ 1197 fsize = spa_get_asize(tx->tx_pool->dp_spa, tooverwrite) + tofree; 1198 /* convert unrefd space to worst-case estimate */ 1199 usize = spa_get_asize(tx->tx_pool->dp_spa, tounref); 1200 /* calculate memory footprint estimate */ 1201 memory = towrite + tooverwrite + tohold; 1202 1203#ifdef ZFS_DEBUG 1204 /* 1205 * Add in 'tohold' to account for our dirty holds on this memory 1206 * XXX - the "fudge" factor is to account for skipped blocks that 1207 * we missed because dnode_next_offset() misses in-core-only blocks. 1208 */ 1209 tx->tx_space_towrite = asize + 1210 spa_get_asize(tx->tx_pool->dp_spa, tohold + fudge); 1211 tx->tx_space_tofree = tofree; 1212 tx->tx_space_tooverwrite = tooverwrite; 1213 tx->tx_space_tounref = tounref; 1214#endif 1215 1216 if (tx->tx_dir && asize != 0) { 1217 int err = dsl_dir_tempreserve_space(tx->tx_dir, memory, 1218 asize, fsize, usize, &tx->tx_tempreserve_cookie, tx); 1219 if (err) 1220 return (err); 1221 } 1222 1223 return (0); 1224} 1225 1226static void 1227dmu_tx_unassign(dmu_tx_t *tx) 1228{ 1229 dmu_tx_hold_t *txh; 1230 1231 if (tx->tx_txg == 0) 1232 return; 1233 1234 txg_rele_to_quiesce(&tx->tx_txgh); 1235 1236 /* 1237 * Walk the transaction's hold list, removing the hold on the 1238 * associated dnode, and notifying waiters if the refcount drops to 0. 1239 */ 1240 for (txh = list_head(&tx->tx_holds); txh != tx->tx_needassign_txh; 1241 txh = list_next(&tx->tx_holds, txh)) { 1242 dnode_t *dn = txh->txh_dnode; 1243 1244 if (dn == NULL) 1245 continue; 1246 mutex_enter(&dn->dn_mtx); 1247 ASSERT3U(dn->dn_assigned_txg, ==, tx->tx_txg); 1248 1249 if (refcount_remove(&dn->dn_tx_holds, tx) == 0) { 1250 dn->dn_assigned_txg = 0; 1251 cv_broadcast(&dn->dn_notxholds); 1252 } 1253 mutex_exit(&dn->dn_mtx); 1254 } 1255 1256 txg_rele_to_sync(&tx->tx_txgh); 1257 1258 tx->tx_lasttried_txg = tx->tx_txg; 1259 tx->tx_txg = 0; 1260} 1261 1262/* 1263 * Assign tx to a transaction group. txg_how can be one of: 1264 * 1265 * (1) TXG_WAIT. If the current open txg is full, waits until there's 1266 * a new one. This should be used when you're not holding locks. 1267 * It will only fail if we're truly out of space (or over quota). 1268 * 1269 * (2) TXG_NOWAIT. If we can't assign into the current open txg without 1270 * blocking, returns immediately with ERESTART. This should be used 1271 * whenever you're holding locks. On an ERESTART error, the caller 1272 * should drop locks, do a dmu_tx_wait(tx), and try again. 1273 * 1274 * (3) TXG_WAITED. Like TXG_NOWAIT, but indicates that dmu_tx_wait() 1275 * has already been called on behalf of this operation (though 1276 * most likely on a different tx). 1277 */ 1278int 1279dmu_tx_assign(dmu_tx_t *tx, txg_how_t txg_how) 1280{ 1281 int err; 1282 1283 ASSERT(tx->tx_txg == 0); 1284 ASSERT(txg_how == TXG_WAIT || txg_how == TXG_NOWAIT || 1285 txg_how == TXG_WAITED); 1286 ASSERT(!dsl_pool_sync_context(tx->tx_pool)); 1287 1288 /* If we might wait, we must not hold the config lock. */ 1289 ASSERT(txg_how != TXG_WAIT || !dsl_pool_config_held(tx->tx_pool)); 1290 1291 if (txg_how == TXG_WAITED) 1292 tx->tx_waited = B_TRUE; 1293 1294 while ((err = dmu_tx_try_assign(tx, txg_how)) != 0) { 1295 dmu_tx_unassign(tx); 1296 1297 if (err != ERESTART || txg_how != TXG_WAIT) 1298 return (err); 1299 1300 dmu_tx_wait(tx); 1301 } 1302 1303 txg_rele_to_quiesce(&tx->tx_txgh); 1304 1305 return (0); 1306} 1307 1308void 1309dmu_tx_wait(dmu_tx_t *tx) 1310{ 1311 spa_t *spa = tx->tx_pool->dp_spa; 1312 dsl_pool_t *dp = tx->tx_pool; 1313 1314 ASSERT(tx->tx_txg == 0); 1315 ASSERT(!dsl_pool_config_held(tx->tx_pool)); 1316 1317 if (tx->tx_wait_dirty) { 1318 /* 1319 * dmu_tx_try_assign() has determined that we need to wait 1320 * because we've consumed much or all of the dirty buffer 1321 * space. 1322 */ 1323 mutex_enter(&dp->dp_lock); 1324 while (dp->dp_dirty_total >= zfs_dirty_data_max) 1325 cv_wait(&dp->dp_spaceavail_cv, &dp->dp_lock); 1326 uint64_t dirty = dp->dp_dirty_total; 1327 mutex_exit(&dp->dp_lock); 1328 1329 dmu_tx_delay(tx, dirty); 1330 1331 tx->tx_wait_dirty = B_FALSE; 1332 1333 /* 1334 * Note: setting tx_waited only has effect if the caller 1335 * used TX_WAIT. Otherwise they are going to destroy 1336 * this tx and try again. The common case, zfs_write(), 1337 * uses TX_WAIT. 1338 */ 1339 tx->tx_waited = B_TRUE; 1340 } else if (spa_suspended(spa) || tx->tx_lasttried_txg == 0) { 1341 /* 1342 * If the pool is suspended we need to wait until it 1343 * is resumed. Note that it's possible that the pool 1344 * has become active after this thread has tried to 1345 * obtain a tx. If that's the case then tx_lasttried_txg 1346 * would not have been set. 1347 */ 1348 txg_wait_synced(dp, spa_last_synced_txg(spa) + 1); 1349 } else if (tx->tx_needassign_txh) { 1350 /* 1351 * A dnode is assigned to the quiescing txg. Wait for its 1352 * transaction to complete. 1353 */ 1354 dnode_t *dn = tx->tx_needassign_txh->txh_dnode; 1355 1356 mutex_enter(&dn->dn_mtx); 1357 while (dn->dn_assigned_txg == tx->tx_lasttried_txg - 1) 1358 cv_wait(&dn->dn_notxholds, &dn->dn_mtx); 1359 mutex_exit(&dn->dn_mtx); 1360 tx->tx_needassign_txh = NULL; 1361 } else { 1362 txg_wait_open(tx->tx_pool, tx->tx_lasttried_txg + 1); 1363 } 1364} 1365 1366void 1367dmu_tx_willuse_space(dmu_tx_t *tx, int64_t delta) 1368{ 1369#ifdef ZFS_DEBUG 1370 if (tx->tx_dir == NULL || delta == 0) 1371 return; 1372 1373 if (delta > 0) { 1374 ASSERT3U(refcount_count(&tx->tx_space_written) + delta, <=, 1375 tx->tx_space_towrite); 1376 (void) refcount_add_many(&tx->tx_space_written, delta, NULL); 1377 } else { 1378 (void) refcount_add_many(&tx->tx_space_freed, -delta, NULL); 1379 } 1380#endif 1381} 1382 1383void 1384dmu_tx_commit(dmu_tx_t *tx) 1385{ 1386 dmu_tx_hold_t *txh; 1387 1388 ASSERT(tx->tx_txg != 0); 1389 1390 /* 1391 * Go through the transaction's hold list and remove holds on 1392 * associated dnodes, notifying waiters if no holds remain. 1393 */ 1394 while (txh = list_head(&tx->tx_holds)) { 1395 dnode_t *dn = txh->txh_dnode; 1396 1397 list_remove(&tx->tx_holds, txh); 1398 kmem_free(txh, sizeof (dmu_tx_hold_t)); 1399 if (dn == NULL) 1400 continue; 1401 mutex_enter(&dn->dn_mtx); 1402 ASSERT3U(dn->dn_assigned_txg, ==, tx->tx_txg); 1403 1404 if (refcount_remove(&dn->dn_tx_holds, tx) == 0) { 1405 dn->dn_assigned_txg = 0; 1406 cv_broadcast(&dn->dn_notxholds); 1407 } 1408 mutex_exit(&dn->dn_mtx); 1409 dnode_rele(dn, tx); 1410 } 1411 1412 if (tx->tx_tempreserve_cookie) 1413 dsl_dir_tempreserve_clear(tx->tx_tempreserve_cookie, tx); 1414 1415 if (!list_is_empty(&tx->tx_callbacks)) 1416 txg_register_callbacks(&tx->tx_txgh, &tx->tx_callbacks); 1417 1418 if (tx->tx_anyobj == FALSE) 1419 txg_rele_to_sync(&tx->tx_txgh); 1420 1421 list_destroy(&tx->tx_callbacks); 1422 list_destroy(&tx->tx_holds); 1423#ifdef ZFS_DEBUG 1424 dprintf("towrite=%llu written=%llu tofree=%llu freed=%llu\n", 1425 tx->tx_space_towrite, refcount_count(&tx->tx_space_written), 1426 tx->tx_space_tofree, refcount_count(&tx->tx_space_freed)); 1427 refcount_destroy_many(&tx->tx_space_written, 1428 refcount_count(&tx->tx_space_written)); 1429 refcount_destroy_many(&tx->tx_space_freed, 1430 refcount_count(&tx->tx_space_freed)); 1431#endif 1432 kmem_free(tx, sizeof (dmu_tx_t)); 1433} 1434 1435void 1436dmu_tx_abort(dmu_tx_t *tx) 1437{ 1438 dmu_tx_hold_t *txh; 1439 1440 ASSERT(tx->tx_txg == 0); 1441 1442 while (txh = list_head(&tx->tx_holds)) { 1443 dnode_t *dn = txh->txh_dnode; 1444 1445 list_remove(&tx->tx_holds, txh); 1446 kmem_free(txh, sizeof (dmu_tx_hold_t)); 1447 if (dn != NULL) 1448 dnode_rele(dn, tx); 1449 } 1450 1451 /* 1452 * Call any registered callbacks with an error code. 1453 */ 1454 if (!list_is_empty(&tx->tx_callbacks)) 1455 dmu_tx_do_callbacks(&tx->tx_callbacks, ECANCELED); 1456 1457 list_destroy(&tx->tx_callbacks); 1458 list_destroy(&tx->tx_holds); 1459#ifdef ZFS_DEBUG 1460 refcount_destroy_many(&tx->tx_space_written, 1461 refcount_count(&tx->tx_space_written)); 1462 refcount_destroy_many(&tx->tx_space_freed, 1463 refcount_count(&tx->tx_space_freed)); 1464#endif 1465 kmem_free(tx, sizeof (dmu_tx_t)); 1466} 1467 1468uint64_t 1469dmu_tx_get_txg(dmu_tx_t *tx) 1470{ 1471 ASSERT(tx->tx_txg != 0); 1472 return (tx->tx_txg); 1473} 1474 1475dsl_pool_t * 1476dmu_tx_pool(dmu_tx_t *tx) 1477{ 1478 ASSERT(tx->tx_pool != NULL); 1479 return (tx->tx_pool); 1480} 1481 1482 1483void 1484dmu_tx_callback_register(dmu_tx_t *tx, dmu_tx_callback_func_t *func, void *data) 1485{ 1486 dmu_tx_callback_t *dcb; 1487 1488 dcb = kmem_alloc(sizeof (dmu_tx_callback_t), KM_SLEEP); 1489 1490 dcb->dcb_func = func; 1491 dcb->dcb_data = data; 1492 1493 list_insert_tail(&tx->tx_callbacks, dcb); 1494} 1495 1496/* 1497 * Call all the commit callbacks on a list, with a given error code. 1498 */ 1499void 1500dmu_tx_do_callbacks(list_t *cb_list, int error) 1501{ 1502 dmu_tx_callback_t *dcb; 1503 1504 while (dcb = list_head(cb_list)) { 1505 list_remove(cb_list, dcb); 1506 dcb->dcb_func(dcb->dcb_data, error); 1507 kmem_free(dcb, sizeof (dmu_tx_callback_t)); 1508 } 1509} 1510 1511/* 1512 * Interface to hold a bunch of attributes. 1513 * used for creating new files. 1514 * attrsize is the total size of all attributes 1515 * to be added during object creation 1516 * 1517 * For updating/adding a single attribute dmu_tx_hold_sa() should be used. 1518 */ 1519 1520/* 1521 * hold necessary attribute name for attribute registration. 1522 * should be a very rare case where this is needed. If it does 1523 * happen it would only happen on the first write to the file system. 1524 */ 1525static void 1526dmu_tx_sa_registration_hold(sa_os_t *sa, dmu_tx_t *tx) 1527{ 1528 int i; 1529 1530 if (!sa->sa_need_attr_registration) 1531 return; 1532 1533 for (i = 0; i != sa->sa_num_attrs; i++) { 1534 if (!sa->sa_attr_table[i].sa_registered) { 1535 if (sa->sa_reg_attr_obj) 1536 dmu_tx_hold_zap(tx, sa->sa_reg_attr_obj, 1537 B_TRUE, sa->sa_attr_table[i].sa_name); 1538 else 1539 dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, 1540 B_TRUE, sa->sa_attr_table[i].sa_name); 1541 } 1542 } 1543} 1544 1545 1546void 1547dmu_tx_hold_spill(dmu_tx_t *tx, uint64_t object) 1548{ 1549 dnode_t *dn; 1550 dmu_tx_hold_t *txh; 1551 1552 txh = dmu_tx_hold_object_impl(tx, tx->tx_objset, object, 1553 THT_SPILL, 0, 0); 1554 1555 dn = txh->txh_dnode; 1556 1557 if (dn == NULL) 1558 return; 1559 1560 /* If blkptr doesn't exist then add space to towrite */ 1561 if (!(dn->dn_phys->dn_flags & DNODE_FLAG_SPILL_BLKPTR)) { 1562 txh->txh_space_towrite += SPA_OLD_MAXBLOCKSIZE; 1563 } else { 1564 blkptr_t *bp; 1565 1566 bp = &dn->dn_phys->dn_spill; 1567 if (dsl_dataset_block_freeable(dn->dn_objset->os_dsl_dataset, 1568 bp, bp->blk_birth)) 1569 txh->txh_space_tooverwrite += SPA_OLD_MAXBLOCKSIZE; 1570 else 1571 txh->txh_space_towrite += SPA_OLD_MAXBLOCKSIZE; 1572 if (!BP_IS_HOLE(bp)) 1573 txh->txh_space_tounref += SPA_OLD_MAXBLOCKSIZE; 1574 } 1575} 1576 1577void 1578dmu_tx_hold_sa_create(dmu_tx_t *tx, int attrsize) 1579{ 1580 sa_os_t *sa = tx->tx_objset->os_sa; 1581 1582 dmu_tx_hold_bonus(tx, DMU_NEW_OBJECT); 1583 1584 if (tx->tx_objset->os_sa->sa_master_obj == 0) 1585 return; 1586 1587 if (tx->tx_objset->os_sa->sa_layout_attr_obj) 1588 dmu_tx_hold_zap(tx, sa->sa_layout_attr_obj, B_TRUE, NULL); 1589 else { 1590 dmu_tx_hold_zap(tx, sa->sa_master_obj, B_TRUE, SA_LAYOUTS); 1591 dmu_tx_hold_zap(tx, sa->sa_master_obj, B_TRUE, SA_REGISTRY); 1592 dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, B_TRUE, NULL); 1593 dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, B_TRUE, NULL); 1594 } 1595 1596 dmu_tx_sa_registration_hold(sa, tx); 1597 1598 if (attrsize <= DN_MAX_BONUSLEN && !sa->sa_force_spill) 1599 return; 1600 1601 (void) dmu_tx_hold_object_impl(tx, tx->tx_objset, DMU_NEW_OBJECT, 1602 THT_SPILL, 0, 0); 1603} 1604 1605/* 1606 * Hold SA attribute 1607 * 1608 * dmu_tx_hold_sa(dmu_tx_t *tx, sa_handle_t *, attribute, add, size) 1609 * 1610 * variable_size is the total size of all variable sized attributes 1611 * passed to this function. It is not the total size of all 1612 * variable size attributes that *may* exist on this object. 1613 */ 1614void 1615dmu_tx_hold_sa(dmu_tx_t *tx, sa_handle_t *hdl, boolean_t may_grow) 1616{ 1617 uint64_t object; 1618 sa_os_t *sa = tx->tx_objset->os_sa; 1619 1620 ASSERT(hdl != NULL); 1621 1622 object = sa_handle_object(hdl); 1623 1624 dmu_tx_hold_bonus(tx, object); 1625 1626 if (tx->tx_objset->os_sa->sa_master_obj == 0) 1627 return; 1628 1629 if (tx->tx_objset->os_sa->sa_reg_attr_obj == 0 || 1630 tx->tx_objset->os_sa->sa_layout_attr_obj == 0) { 1631 dmu_tx_hold_zap(tx, sa->sa_master_obj, B_TRUE, SA_LAYOUTS); 1632 dmu_tx_hold_zap(tx, sa->sa_master_obj, B_TRUE, SA_REGISTRY); 1633 dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, B_TRUE, NULL); 1634 dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, B_TRUE, NULL); 1635 } 1636 1637 dmu_tx_sa_registration_hold(sa, tx); 1638 1639 if (may_grow && tx->tx_objset->os_sa->sa_layout_attr_obj) 1640 dmu_tx_hold_zap(tx, sa->sa_layout_attr_obj, B_TRUE, NULL); 1641 1642 if (sa->sa_force_spill || may_grow || hdl->sa_spill) { 1643 ASSERT(tx->tx_txg == 0); 1644 dmu_tx_hold_spill(tx, object); 1645 } else { 1646 dmu_buf_impl_t *db = (dmu_buf_impl_t *)hdl->sa_bonus; 1647 dnode_t *dn; 1648 1649 DB_DNODE_ENTER(db); 1650 dn = DB_DNODE(db); 1651 if (dn->dn_have_spill) { 1652 ASSERT(tx->tx_txg == 0); 1653 dmu_tx_hold_spill(tx, object); 1654 } 1655 DB_DNODE_EXIT(db); 1656 } 1657} 1658