dmu_tx.c revision 276081
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 uint64_t nblocks; 718 int epbs, err; 719 720 ASSERT(tx->tx_txg == 0); 721 722 txh = dmu_tx_hold_object_impl(tx, tx->tx_objset, 723 object, THT_ZAP, add, (uintptr_t)name); 724 if (txh == NULL) 725 return; 726 dn = txh->txh_dnode; 727 728 dmu_tx_count_dnode(txh); 729 730 if (dn == NULL) { 731 /* 732 * We will be able to fit a new object's entries into one leaf 733 * block. So there will be at most 2 blocks total, 734 * including the header block. 735 */ 736 dmu_tx_count_write(txh, 0, 2 << fzap_default_block_shift); 737 return; 738 } 739 740 ASSERT3P(DMU_OT_BYTESWAP(dn->dn_type), ==, DMU_BSWAP_ZAP); 741 742 if (dn->dn_maxblkid == 0 && !add) { 743 blkptr_t *bp; 744 745 /* 746 * If there is only one block (i.e. this is a micro-zap) 747 * and we are not adding anything, the accounting is simple. 748 */ 749 err = dmu_tx_check_ioerr(NULL, dn, 0, 0); 750 if (err) { 751 tx->tx_err = err; 752 return; 753 } 754 755 /* 756 * Use max block size here, since we don't know how much 757 * the size will change between now and the dbuf dirty call. 758 */ 759 bp = &dn->dn_phys->dn_blkptr[0]; 760 if (dsl_dataset_block_freeable(dn->dn_objset->os_dsl_dataset, 761 bp, bp->blk_birth)) 762 txh->txh_space_tooverwrite += MZAP_MAX_BLKSZ; 763 else 764 txh->txh_space_towrite += MZAP_MAX_BLKSZ; 765 if (!BP_IS_HOLE(bp)) 766 txh->txh_space_tounref += MZAP_MAX_BLKSZ; 767 return; 768 } 769 770 if (dn->dn_maxblkid > 0 && name) { 771 /* 772 * access the name in this fat-zap so that we'll check 773 * for i/o errors to the leaf blocks, etc. 774 */ 775 err = zap_lookup(dn->dn_objset, dn->dn_object, name, 776 8, 0, NULL); 777 if (err == EIO) { 778 tx->tx_err = err; 779 return; 780 } 781 } 782 783 err = zap_count_write(dn->dn_objset, dn->dn_object, name, add, 784 &txh->txh_space_towrite, &txh->txh_space_tooverwrite); 785 786 /* 787 * If the modified blocks are scattered to the four winds, 788 * we'll have to modify an indirect twig for each. 789 */ 790 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT; 791 for (nblocks = dn->dn_maxblkid >> epbs; nblocks != 0; nblocks >>= epbs) 792 if (dn->dn_objset->os_dsl_dataset->ds_phys->ds_prev_snap_obj) 793 txh->txh_space_towrite += 3 << dn->dn_indblkshift; 794 else 795 txh->txh_space_tooverwrite += 3 << dn->dn_indblkshift; 796} 797 798void 799dmu_tx_hold_bonus(dmu_tx_t *tx, uint64_t object) 800{ 801 dmu_tx_hold_t *txh; 802 803 ASSERT(tx->tx_txg == 0); 804 805 txh = dmu_tx_hold_object_impl(tx, tx->tx_objset, 806 object, THT_BONUS, 0, 0); 807 if (txh) 808 dmu_tx_count_dnode(txh); 809} 810 811void 812dmu_tx_hold_space(dmu_tx_t *tx, uint64_t space) 813{ 814 dmu_tx_hold_t *txh; 815 ASSERT(tx->tx_txg == 0); 816 817 txh = dmu_tx_hold_object_impl(tx, tx->tx_objset, 818 DMU_NEW_OBJECT, THT_SPACE, space, 0); 819 820 txh->txh_space_towrite += space; 821} 822 823int 824dmu_tx_holds(dmu_tx_t *tx, uint64_t object) 825{ 826 dmu_tx_hold_t *txh; 827 int holds = 0; 828 829 /* 830 * By asserting that the tx is assigned, we're counting the 831 * number of dn_tx_holds, which is the same as the number of 832 * dn_holds. Otherwise, we'd be counting dn_holds, but 833 * dn_tx_holds could be 0. 834 */ 835 ASSERT(tx->tx_txg != 0); 836 837 /* if (tx->tx_anyobj == TRUE) */ 838 /* return (0); */ 839 840 for (txh = list_head(&tx->tx_holds); txh; 841 txh = list_next(&tx->tx_holds, txh)) { 842 if (txh->txh_dnode && txh->txh_dnode->dn_object == object) 843 holds++; 844 } 845 846 return (holds); 847} 848 849#ifdef ZFS_DEBUG 850void 851dmu_tx_dirty_buf(dmu_tx_t *tx, dmu_buf_impl_t *db) 852{ 853 dmu_tx_hold_t *txh; 854 int match_object = FALSE, match_offset = FALSE; 855 dnode_t *dn; 856 857 DB_DNODE_ENTER(db); 858 dn = DB_DNODE(db); 859 ASSERT(tx->tx_txg != 0); 860 ASSERT(tx->tx_objset == NULL || dn->dn_objset == tx->tx_objset); 861 ASSERT3U(dn->dn_object, ==, db->db.db_object); 862 863 if (tx->tx_anyobj) { 864 DB_DNODE_EXIT(db); 865 return; 866 } 867 868 /* XXX No checking on the meta dnode for now */ 869 if (db->db.db_object == DMU_META_DNODE_OBJECT) { 870 DB_DNODE_EXIT(db); 871 return; 872 } 873 874 for (txh = list_head(&tx->tx_holds); txh; 875 txh = list_next(&tx->tx_holds, txh)) { 876 ASSERT(dn == NULL || dn->dn_assigned_txg == tx->tx_txg); 877 if (txh->txh_dnode == dn && txh->txh_type != THT_NEWOBJECT) 878 match_object = TRUE; 879 if (txh->txh_dnode == NULL || txh->txh_dnode == dn) { 880 int datablkshift = dn->dn_datablkshift ? 881 dn->dn_datablkshift : SPA_MAXBLOCKSHIFT; 882 int epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT; 883 int shift = datablkshift + epbs * db->db_level; 884 uint64_t beginblk = shift >= 64 ? 0 : 885 (txh->txh_arg1 >> shift); 886 uint64_t endblk = shift >= 64 ? 0 : 887 ((txh->txh_arg1 + txh->txh_arg2 - 1) >> shift); 888 uint64_t blkid = db->db_blkid; 889 890 /* XXX txh_arg2 better not be zero... */ 891 892 dprintf("found txh type %x beginblk=%llx endblk=%llx\n", 893 txh->txh_type, beginblk, endblk); 894 895 switch (txh->txh_type) { 896 case THT_WRITE: 897 if (blkid >= beginblk && blkid <= endblk) 898 match_offset = TRUE; 899 /* 900 * We will let this hold work for the bonus 901 * or spill buffer so that we don't need to 902 * hold it when creating a new object. 903 */ 904 if (blkid == DMU_BONUS_BLKID || 905 blkid == DMU_SPILL_BLKID) 906 match_offset = TRUE; 907 /* 908 * They might have to increase nlevels, 909 * thus dirtying the new TLIBs. Or the 910 * might have to change the block size, 911 * thus dirying the new lvl=0 blk=0. 912 */ 913 if (blkid == 0) 914 match_offset = TRUE; 915 break; 916 case THT_FREE: 917 /* 918 * We will dirty all the level 1 blocks in 919 * the free range and perhaps the first and 920 * last level 0 block. 921 */ 922 if (blkid >= beginblk && (blkid <= endblk || 923 txh->txh_arg2 == DMU_OBJECT_END)) 924 match_offset = TRUE; 925 break; 926 case THT_SPILL: 927 if (blkid == DMU_SPILL_BLKID) 928 match_offset = TRUE; 929 break; 930 case THT_BONUS: 931 if (blkid == DMU_BONUS_BLKID) 932 match_offset = TRUE; 933 break; 934 case THT_ZAP: 935 match_offset = TRUE; 936 break; 937 case THT_NEWOBJECT: 938 match_object = TRUE; 939 break; 940 default: 941 ASSERT(!"bad txh_type"); 942 } 943 } 944 if (match_object && match_offset) { 945 DB_DNODE_EXIT(db); 946 return; 947 } 948 } 949 DB_DNODE_EXIT(db); 950 panic("dirtying dbuf obj=%llx lvl=%u blkid=%llx but not tx_held\n", 951 (u_longlong_t)db->db.db_object, db->db_level, 952 (u_longlong_t)db->db_blkid); 953} 954#endif 955 956/* 957 * If we can't do 10 iops, something is wrong. Let us go ahead 958 * and hit zfs_dirty_data_max. 959 */ 960hrtime_t zfs_delay_max_ns = MSEC2NSEC(100); 961int zfs_delay_resolution_ns = 100 * 1000; /* 100 microseconds */ 962 963/* 964 * We delay transactions when we've determined that the backend storage 965 * isn't able to accommodate the rate of incoming writes. 966 * 967 * If there is already a transaction waiting, we delay relative to when 968 * that transaction finishes waiting. This way the calculated min_time 969 * is independent of the number of threads concurrently executing 970 * transactions. 971 * 972 * If we are the only waiter, wait relative to when the transaction 973 * started, rather than the current time. This credits the transaction for 974 * "time already served", e.g. reading indirect blocks. 975 * 976 * The minimum time for a transaction to take is calculated as: 977 * min_time = scale * (dirty - min) / (max - dirty) 978 * min_time is then capped at zfs_delay_max_ns. 979 * 980 * The delay has two degrees of freedom that can be adjusted via tunables. 981 * The percentage of dirty data at which we start to delay is defined by 982 * zfs_delay_min_dirty_percent. This should typically be at or above 983 * zfs_vdev_async_write_active_max_dirty_percent so that we only start to 984 * delay after writing at full speed has failed to keep up with the incoming 985 * write rate. The scale of the curve is defined by zfs_delay_scale. Roughly 986 * speaking, this variable determines the amount of delay at the midpoint of 987 * the curve. 988 * 989 * delay 990 * 10ms +-------------------------------------------------------------*+ 991 * | *| 992 * 9ms + *+ 993 * | *| 994 * 8ms + *+ 995 * | * | 996 * 7ms + * + 997 * | * | 998 * 6ms + * + 999 * | * | 1000 * 5ms + * + 1001 * | * | 1002 * 4ms + * + 1003 * | * | 1004 * 3ms + * + 1005 * | * | 1006 * 2ms + (midpoint) * + 1007 * | | ** | 1008 * 1ms + v *** + 1009 * | zfs_delay_scale ----------> ******** | 1010 * 0 +-------------------------------------*********----------------+ 1011 * 0% <- zfs_dirty_data_max -> 100% 1012 * 1013 * Note that since the delay is added to the outstanding time remaining on the 1014 * most recent transaction, the delay is effectively the inverse of IOPS. 1015 * Here the midpoint of 500us translates to 2000 IOPS. The shape of the curve 1016 * was chosen such that small changes in the amount of accumulated dirty data 1017 * in the first 3/4 of the curve yield relatively small differences in the 1018 * amount of delay. 1019 * 1020 * The effects can be easier to understand when the amount of delay is 1021 * represented on a log scale: 1022 * 1023 * delay 1024 * 100ms +-------------------------------------------------------------++ 1025 * + + 1026 * | | 1027 * + *+ 1028 * 10ms + *+ 1029 * + ** + 1030 * | (midpoint) ** | 1031 * + | ** + 1032 * 1ms + v **** + 1033 * + zfs_delay_scale ----------> ***** + 1034 * | **** | 1035 * + **** + 1036 * 100us + ** + 1037 * + * + 1038 * | * | 1039 * + * + 1040 * 10us + * + 1041 * + + 1042 * | | 1043 * + + 1044 * +--------------------------------------------------------------+ 1045 * 0% <- zfs_dirty_data_max -> 100% 1046 * 1047 * Note here that only as the amount of dirty data approaches its limit does 1048 * the delay start to increase rapidly. The goal of a properly tuned system 1049 * should be to keep the amount of dirty data out of that range by first 1050 * ensuring that the appropriate limits are set for the I/O scheduler to reach 1051 * optimal throughput on the backend storage, and then by changing the value 1052 * of zfs_delay_scale to increase the steepness of the curve. 1053 */ 1054static void 1055dmu_tx_delay(dmu_tx_t *tx, uint64_t dirty) 1056{ 1057 dsl_pool_t *dp = tx->tx_pool; 1058 uint64_t delay_min_bytes = 1059 zfs_dirty_data_max * zfs_delay_min_dirty_percent / 100; 1060 hrtime_t wakeup, min_tx_time, now; 1061 1062 if (dirty <= delay_min_bytes) 1063 return; 1064 1065 /* 1066 * The caller has already waited until we are under the max. 1067 * We make them pass us the amount of dirty data so we don't 1068 * have to handle the case of it being >= the max, which could 1069 * cause a divide-by-zero if it's == the max. 1070 */ 1071 ASSERT3U(dirty, <, zfs_dirty_data_max); 1072 1073 now = gethrtime(); 1074 min_tx_time = zfs_delay_scale * 1075 (dirty - delay_min_bytes) / (zfs_dirty_data_max - dirty); 1076 if (now > tx->tx_start + min_tx_time) 1077 return; 1078 1079 min_tx_time = MIN(min_tx_time, zfs_delay_max_ns); 1080 1081 DTRACE_PROBE3(delay__mintime, dmu_tx_t *, tx, uint64_t, dirty, 1082 uint64_t, min_tx_time); 1083 1084 mutex_enter(&dp->dp_lock); 1085 wakeup = MAX(tx->tx_start + min_tx_time, 1086 dp->dp_last_wakeup + min_tx_time); 1087 dp->dp_last_wakeup = wakeup; 1088 mutex_exit(&dp->dp_lock); 1089 1090#ifdef _KERNEL 1091#ifdef illumos 1092 mutex_enter(&curthread->t_delay_lock); 1093 while (cv_timedwait_hires(&curthread->t_delay_cv, 1094 &curthread->t_delay_lock, wakeup, zfs_delay_resolution_ns, 1095 CALLOUT_FLAG_ABSOLUTE | CALLOUT_FLAG_ROUNDUP) > 0) 1096 continue; 1097 mutex_exit(&curthread->t_delay_lock); 1098#else 1099 pause_sbt("dmu_tx_delay", wakeup * SBT_1NS, 1100 zfs_delay_resolution_ns * SBT_1NS, C_ABSOLUTE); 1101#endif 1102#else 1103 hrtime_t delta = wakeup - gethrtime(); 1104 struct timespec ts; 1105 ts.tv_sec = delta / NANOSEC; 1106 ts.tv_nsec = delta % NANOSEC; 1107 (void) nanosleep(&ts, NULL); 1108#endif 1109} 1110 1111static int 1112dmu_tx_try_assign(dmu_tx_t *tx, txg_how_t txg_how) 1113{ 1114 dmu_tx_hold_t *txh; 1115 spa_t *spa = tx->tx_pool->dp_spa; 1116 uint64_t memory, asize, fsize, usize; 1117 uint64_t towrite, tofree, tooverwrite, tounref, tohold, fudge; 1118 1119 ASSERT0(tx->tx_txg); 1120 1121 if (tx->tx_err) 1122 return (tx->tx_err); 1123 1124 if (spa_suspended(spa)) { 1125 /* 1126 * If the user has indicated a blocking failure mode 1127 * then return ERESTART which will block in dmu_tx_wait(). 1128 * Otherwise, return EIO so that an error can get 1129 * propagated back to the VOP calls. 1130 * 1131 * Note that we always honor the txg_how flag regardless 1132 * of the failuremode setting. 1133 */ 1134 if (spa_get_failmode(spa) == ZIO_FAILURE_MODE_CONTINUE && 1135 txg_how != TXG_WAIT) 1136 return (SET_ERROR(EIO)); 1137 1138 return (SET_ERROR(ERESTART)); 1139 } 1140 1141 if (!tx->tx_waited && 1142 dsl_pool_need_dirty_delay(tx->tx_pool)) { 1143 tx->tx_wait_dirty = B_TRUE; 1144 return (SET_ERROR(ERESTART)); 1145 } 1146 1147 tx->tx_txg = txg_hold_open(tx->tx_pool, &tx->tx_txgh); 1148 tx->tx_needassign_txh = NULL; 1149 1150 /* 1151 * NB: No error returns are allowed after txg_hold_open, but 1152 * before processing the dnode holds, due to the 1153 * dmu_tx_unassign() logic. 1154 */ 1155 1156 towrite = tofree = tooverwrite = tounref = tohold = fudge = 0; 1157 for (txh = list_head(&tx->tx_holds); txh; 1158 txh = list_next(&tx->tx_holds, txh)) { 1159 dnode_t *dn = txh->txh_dnode; 1160 if (dn != NULL) { 1161 mutex_enter(&dn->dn_mtx); 1162 if (dn->dn_assigned_txg == tx->tx_txg - 1) { 1163 mutex_exit(&dn->dn_mtx); 1164 tx->tx_needassign_txh = txh; 1165 return (SET_ERROR(ERESTART)); 1166 } 1167 if (dn->dn_assigned_txg == 0) 1168 dn->dn_assigned_txg = tx->tx_txg; 1169 ASSERT3U(dn->dn_assigned_txg, ==, tx->tx_txg); 1170 (void) refcount_add(&dn->dn_tx_holds, tx); 1171 mutex_exit(&dn->dn_mtx); 1172 } 1173 towrite += txh->txh_space_towrite; 1174 tofree += txh->txh_space_tofree; 1175 tooverwrite += txh->txh_space_tooverwrite; 1176 tounref += txh->txh_space_tounref; 1177 tohold += txh->txh_memory_tohold; 1178 fudge += txh->txh_fudge; 1179 } 1180 1181 /* 1182 * If a snapshot has been taken since we made our estimates, 1183 * assume that we won't be able to free or overwrite anything. 1184 */ 1185 if (tx->tx_objset && 1186 dsl_dataset_prev_snap_txg(tx->tx_objset->os_dsl_dataset) > 1187 tx->tx_lastsnap_txg) { 1188 towrite += tooverwrite; 1189 tooverwrite = tofree = 0; 1190 } 1191 1192 /* needed allocation: worst-case estimate of write space */ 1193 asize = spa_get_asize(tx->tx_pool->dp_spa, towrite + tooverwrite); 1194 /* freed space estimate: worst-case overwrite + free estimate */ 1195 fsize = spa_get_asize(tx->tx_pool->dp_spa, tooverwrite) + tofree; 1196 /* convert unrefd space to worst-case estimate */ 1197 usize = spa_get_asize(tx->tx_pool->dp_spa, tounref); 1198 /* calculate memory footprint estimate */ 1199 memory = towrite + tooverwrite + tohold; 1200 1201#ifdef ZFS_DEBUG 1202 /* 1203 * Add in 'tohold' to account for our dirty holds on this memory 1204 * XXX - the "fudge" factor is to account for skipped blocks that 1205 * we missed because dnode_next_offset() misses in-core-only blocks. 1206 */ 1207 tx->tx_space_towrite = asize + 1208 spa_get_asize(tx->tx_pool->dp_spa, tohold + fudge); 1209 tx->tx_space_tofree = tofree; 1210 tx->tx_space_tooverwrite = tooverwrite; 1211 tx->tx_space_tounref = tounref; 1212#endif 1213 1214 if (tx->tx_dir && asize != 0) { 1215 int err = dsl_dir_tempreserve_space(tx->tx_dir, memory, 1216 asize, fsize, usize, &tx->tx_tempreserve_cookie, tx); 1217 if (err) 1218 return (err); 1219 } 1220 1221 return (0); 1222} 1223 1224static void 1225dmu_tx_unassign(dmu_tx_t *tx) 1226{ 1227 dmu_tx_hold_t *txh; 1228 1229 if (tx->tx_txg == 0) 1230 return; 1231 1232 txg_rele_to_quiesce(&tx->tx_txgh); 1233 1234 /* 1235 * Walk the transaction's hold list, removing the hold on the 1236 * associated dnode, and notifying waiters if the refcount drops to 0. 1237 */ 1238 for (txh = list_head(&tx->tx_holds); txh != tx->tx_needassign_txh; 1239 txh = list_next(&tx->tx_holds, txh)) { 1240 dnode_t *dn = txh->txh_dnode; 1241 1242 if (dn == NULL) 1243 continue; 1244 mutex_enter(&dn->dn_mtx); 1245 ASSERT3U(dn->dn_assigned_txg, ==, tx->tx_txg); 1246 1247 if (refcount_remove(&dn->dn_tx_holds, tx) == 0) { 1248 dn->dn_assigned_txg = 0; 1249 cv_broadcast(&dn->dn_notxholds); 1250 } 1251 mutex_exit(&dn->dn_mtx); 1252 } 1253 1254 txg_rele_to_sync(&tx->tx_txgh); 1255 1256 tx->tx_lasttried_txg = tx->tx_txg; 1257 tx->tx_txg = 0; 1258} 1259 1260/* 1261 * Assign tx to a transaction group. txg_how can be one of: 1262 * 1263 * (1) TXG_WAIT. If the current open txg is full, waits until there's 1264 * a new one. This should be used when you're not holding locks. 1265 * It will only fail if we're truly out of space (or over quota). 1266 * 1267 * (2) TXG_NOWAIT. If we can't assign into the current open txg without 1268 * blocking, returns immediately with ERESTART. This should be used 1269 * whenever you're holding locks. On an ERESTART error, the caller 1270 * should drop locks, do a dmu_tx_wait(tx), and try again. 1271 * 1272 * (3) TXG_WAITED. Like TXG_NOWAIT, but indicates that dmu_tx_wait() 1273 * has already been called on behalf of this operation (though 1274 * most likely on a different tx). 1275 */ 1276int 1277dmu_tx_assign(dmu_tx_t *tx, txg_how_t txg_how) 1278{ 1279 int err; 1280 1281 ASSERT(tx->tx_txg == 0); 1282 ASSERT(txg_how == TXG_WAIT || txg_how == TXG_NOWAIT || 1283 txg_how == TXG_WAITED); 1284 ASSERT(!dsl_pool_sync_context(tx->tx_pool)); 1285 1286 /* If we might wait, we must not hold the config lock. */ 1287 ASSERT(txg_how != TXG_WAIT || !dsl_pool_config_held(tx->tx_pool)); 1288 1289 if (txg_how == TXG_WAITED) 1290 tx->tx_waited = B_TRUE; 1291 1292 while ((err = dmu_tx_try_assign(tx, txg_how)) != 0) { 1293 dmu_tx_unassign(tx); 1294 1295 if (err != ERESTART || txg_how != TXG_WAIT) 1296 return (err); 1297 1298 dmu_tx_wait(tx); 1299 } 1300 1301 txg_rele_to_quiesce(&tx->tx_txgh); 1302 1303 return (0); 1304} 1305 1306void 1307dmu_tx_wait(dmu_tx_t *tx) 1308{ 1309 spa_t *spa = tx->tx_pool->dp_spa; 1310 dsl_pool_t *dp = tx->tx_pool; 1311 1312 ASSERT(tx->tx_txg == 0); 1313 ASSERT(!dsl_pool_config_held(tx->tx_pool)); 1314 1315 if (tx->tx_wait_dirty) { 1316 /* 1317 * dmu_tx_try_assign() has determined that we need to wait 1318 * because we've consumed much or all of the dirty buffer 1319 * space. 1320 */ 1321 mutex_enter(&dp->dp_lock); 1322 while (dp->dp_dirty_total >= zfs_dirty_data_max) 1323 cv_wait(&dp->dp_spaceavail_cv, &dp->dp_lock); 1324 uint64_t dirty = dp->dp_dirty_total; 1325 mutex_exit(&dp->dp_lock); 1326 1327 dmu_tx_delay(tx, dirty); 1328 1329 tx->tx_wait_dirty = B_FALSE; 1330 1331 /* 1332 * Note: setting tx_waited only has effect if the caller 1333 * used TX_WAIT. Otherwise they are going to destroy 1334 * this tx and try again. The common case, zfs_write(), 1335 * uses TX_WAIT. 1336 */ 1337 tx->tx_waited = B_TRUE; 1338 } else if (spa_suspended(spa) || tx->tx_lasttried_txg == 0) { 1339 /* 1340 * If the pool is suspended we need to wait until it 1341 * is resumed. Note that it's possible that the pool 1342 * has become active after this thread has tried to 1343 * obtain a tx. If that's the case then tx_lasttried_txg 1344 * would not have been set. 1345 */ 1346 txg_wait_synced(dp, spa_last_synced_txg(spa) + 1); 1347 } else if (tx->tx_needassign_txh) { 1348 /* 1349 * A dnode is assigned to the quiescing txg. Wait for its 1350 * transaction to complete. 1351 */ 1352 dnode_t *dn = tx->tx_needassign_txh->txh_dnode; 1353 1354 mutex_enter(&dn->dn_mtx); 1355 while (dn->dn_assigned_txg == tx->tx_lasttried_txg - 1) 1356 cv_wait(&dn->dn_notxholds, &dn->dn_mtx); 1357 mutex_exit(&dn->dn_mtx); 1358 tx->tx_needassign_txh = NULL; 1359 } else { 1360 txg_wait_open(tx->tx_pool, tx->tx_lasttried_txg + 1); 1361 } 1362} 1363 1364void 1365dmu_tx_willuse_space(dmu_tx_t *tx, int64_t delta) 1366{ 1367#ifdef ZFS_DEBUG 1368 if (tx->tx_dir == NULL || delta == 0) 1369 return; 1370 1371 if (delta > 0) { 1372 ASSERT3U(refcount_count(&tx->tx_space_written) + delta, <=, 1373 tx->tx_space_towrite); 1374 (void) refcount_add_many(&tx->tx_space_written, delta, NULL); 1375 } else { 1376 (void) refcount_add_many(&tx->tx_space_freed, -delta, NULL); 1377 } 1378#endif 1379} 1380 1381void 1382dmu_tx_commit(dmu_tx_t *tx) 1383{ 1384 dmu_tx_hold_t *txh; 1385 1386 ASSERT(tx->tx_txg != 0); 1387 1388 /* 1389 * Go through the transaction's hold list and remove holds on 1390 * associated dnodes, notifying waiters if no holds remain. 1391 */ 1392 while (txh = list_head(&tx->tx_holds)) { 1393 dnode_t *dn = txh->txh_dnode; 1394 1395 list_remove(&tx->tx_holds, txh); 1396 kmem_free(txh, sizeof (dmu_tx_hold_t)); 1397 if (dn == NULL) 1398 continue; 1399 mutex_enter(&dn->dn_mtx); 1400 ASSERT3U(dn->dn_assigned_txg, ==, tx->tx_txg); 1401 1402 if (refcount_remove(&dn->dn_tx_holds, tx) == 0) { 1403 dn->dn_assigned_txg = 0; 1404 cv_broadcast(&dn->dn_notxholds); 1405 } 1406 mutex_exit(&dn->dn_mtx); 1407 dnode_rele(dn, tx); 1408 } 1409 1410 if (tx->tx_tempreserve_cookie) 1411 dsl_dir_tempreserve_clear(tx->tx_tempreserve_cookie, tx); 1412 1413 if (!list_is_empty(&tx->tx_callbacks)) 1414 txg_register_callbacks(&tx->tx_txgh, &tx->tx_callbacks); 1415 1416 if (tx->tx_anyobj == FALSE) 1417 txg_rele_to_sync(&tx->tx_txgh); 1418 1419 list_destroy(&tx->tx_callbacks); 1420 list_destroy(&tx->tx_holds); 1421#ifdef ZFS_DEBUG 1422 dprintf("towrite=%llu written=%llu tofree=%llu freed=%llu\n", 1423 tx->tx_space_towrite, refcount_count(&tx->tx_space_written), 1424 tx->tx_space_tofree, refcount_count(&tx->tx_space_freed)); 1425 refcount_destroy_many(&tx->tx_space_written, 1426 refcount_count(&tx->tx_space_written)); 1427 refcount_destroy_many(&tx->tx_space_freed, 1428 refcount_count(&tx->tx_space_freed)); 1429#endif 1430 kmem_free(tx, sizeof (dmu_tx_t)); 1431} 1432 1433void 1434dmu_tx_abort(dmu_tx_t *tx) 1435{ 1436 dmu_tx_hold_t *txh; 1437 1438 ASSERT(tx->tx_txg == 0); 1439 1440 while (txh = list_head(&tx->tx_holds)) { 1441 dnode_t *dn = txh->txh_dnode; 1442 1443 list_remove(&tx->tx_holds, txh); 1444 kmem_free(txh, sizeof (dmu_tx_hold_t)); 1445 if (dn != NULL) 1446 dnode_rele(dn, tx); 1447 } 1448 1449 /* 1450 * Call any registered callbacks with an error code. 1451 */ 1452 if (!list_is_empty(&tx->tx_callbacks)) 1453 dmu_tx_do_callbacks(&tx->tx_callbacks, ECANCELED); 1454 1455 list_destroy(&tx->tx_callbacks); 1456 list_destroy(&tx->tx_holds); 1457#ifdef ZFS_DEBUG 1458 refcount_destroy_many(&tx->tx_space_written, 1459 refcount_count(&tx->tx_space_written)); 1460 refcount_destroy_many(&tx->tx_space_freed, 1461 refcount_count(&tx->tx_space_freed)); 1462#endif 1463 kmem_free(tx, sizeof (dmu_tx_t)); 1464} 1465 1466uint64_t 1467dmu_tx_get_txg(dmu_tx_t *tx) 1468{ 1469 ASSERT(tx->tx_txg != 0); 1470 return (tx->tx_txg); 1471} 1472 1473dsl_pool_t * 1474dmu_tx_pool(dmu_tx_t *tx) 1475{ 1476 ASSERT(tx->tx_pool != NULL); 1477 return (tx->tx_pool); 1478} 1479 1480 1481void 1482dmu_tx_callback_register(dmu_tx_t *tx, dmu_tx_callback_func_t *func, void *data) 1483{ 1484 dmu_tx_callback_t *dcb; 1485 1486 dcb = kmem_alloc(sizeof (dmu_tx_callback_t), KM_SLEEP); 1487 1488 dcb->dcb_func = func; 1489 dcb->dcb_data = data; 1490 1491 list_insert_tail(&tx->tx_callbacks, dcb); 1492} 1493 1494/* 1495 * Call all the commit callbacks on a list, with a given error code. 1496 */ 1497void 1498dmu_tx_do_callbacks(list_t *cb_list, int error) 1499{ 1500 dmu_tx_callback_t *dcb; 1501 1502 while (dcb = list_head(cb_list)) { 1503 list_remove(cb_list, dcb); 1504 dcb->dcb_func(dcb->dcb_data, error); 1505 kmem_free(dcb, sizeof (dmu_tx_callback_t)); 1506 } 1507} 1508 1509/* 1510 * Interface to hold a bunch of attributes. 1511 * used for creating new files. 1512 * attrsize is the total size of all attributes 1513 * to be added during object creation 1514 * 1515 * For updating/adding a single attribute dmu_tx_hold_sa() should be used. 1516 */ 1517 1518/* 1519 * hold necessary attribute name for attribute registration. 1520 * should be a very rare case where this is needed. If it does 1521 * happen it would only happen on the first write to the file system. 1522 */ 1523static void 1524dmu_tx_sa_registration_hold(sa_os_t *sa, dmu_tx_t *tx) 1525{ 1526 int i; 1527 1528 if (!sa->sa_need_attr_registration) 1529 return; 1530 1531 for (i = 0; i != sa->sa_num_attrs; i++) { 1532 if (!sa->sa_attr_table[i].sa_registered) { 1533 if (sa->sa_reg_attr_obj) 1534 dmu_tx_hold_zap(tx, sa->sa_reg_attr_obj, 1535 B_TRUE, sa->sa_attr_table[i].sa_name); 1536 else 1537 dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, 1538 B_TRUE, sa->sa_attr_table[i].sa_name); 1539 } 1540 } 1541} 1542 1543 1544void 1545dmu_tx_hold_spill(dmu_tx_t *tx, uint64_t object) 1546{ 1547 dnode_t *dn; 1548 dmu_tx_hold_t *txh; 1549 1550 txh = dmu_tx_hold_object_impl(tx, tx->tx_objset, object, 1551 THT_SPILL, 0, 0); 1552 1553 dn = txh->txh_dnode; 1554 1555 if (dn == NULL) 1556 return; 1557 1558 /* If blkptr doesn't exist then add space to towrite */ 1559 if (!(dn->dn_phys->dn_flags & DNODE_FLAG_SPILL_BLKPTR)) { 1560 txh->txh_space_towrite += SPA_OLD_MAXBLOCKSIZE; 1561 } else { 1562 blkptr_t *bp; 1563 1564 bp = &dn->dn_phys->dn_spill; 1565 if (dsl_dataset_block_freeable(dn->dn_objset->os_dsl_dataset, 1566 bp, bp->blk_birth)) 1567 txh->txh_space_tooverwrite += SPA_OLD_MAXBLOCKSIZE; 1568 else 1569 txh->txh_space_towrite += SPA_OLD_MAXBLOCKSIZE; 1570 if (!BP_IS_HOLE(bp)) 1571 txh->txh_space_tounref += SPA_OLD_MAXBLOCKSIZE; 1572 } 1573} 1574 1575void 1576dmu_tx_hold_sa_create(dmu_tx_t *tx, int attrsize) 1577{ 1578 sa_os_t *sa = tx->tx_objset->os_sa; 1579 1580 dmu_tx_hold_bonus(tx, DMU_NEW_OBJECT); 1581 1582 if (tx->tx_objset->os_sa->sa_master_obj == 0) 1583 return; 1584 1585 if (tx->tx_objset->os_sa->sa_layout_attr_obj) 1586 dmu_tx_hold_zap(tx, sa->sa_layout_attr_obj, B_TRUE, NULL); 1587 else { 1588 dmu_tx_hold_zap(tx, sa->sa_master_obj, B_TRUE, SA_LAYOUTS); 1589 dmu_tx_hold_zap(tx, sa->sa_master_obj, B_TRUE, SA_REGISTRY); 1590 dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, B_TRUE, NULL); 1591 dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, B_TRUE, NULL); 1592 } 1593 1594 dmu_tx_sa_registration_hold(sa, tx); 1595 1596 if (attrsize <= DN_MAX_BONUSLEN && !sa->sa_force_spill) 1597 return; 1598 1599 (void) dmu_tx_hold_object_impl(tx, tx->tx_objset, DMU_NEW_OBJECT, 1600 THT_SPILL, 0, 0); 1601} 1602 1603/* 1604 * Hold SA attribute 1605 * 1606 * dmu_tx_hold_sa(dmu_tx_t *tx, sa_handle_t *, attribute, add, size) 1607 * 1608 * variable_size is the total size of all variable sized attributes 1609 * passed to this function. It is not the total size of all 1610 * variable size attributes that *may* exist on this object. 1611 */ 1612void 1613dmu_tx_hold_sa(dmu_tx_t *tx, sa_handle_t *hdl, boolean_t may_grow) 1614{ 1615 uint64_t object; 1616 sa_os_t *sa = tx->tx_objset->os_sa; 1617 1618 ASSERT(hdl != NULL); 1619 1620 object = sa_handle_object(hdl); 1621 1622 dmu_tx_hold_bonus(tx, object); 1623 1624 if (tx->tx_objset->os_sa->sa_master_obj == 0) 1625 return; 1626 1627 if (tx->tx_objset->os_sa->sa_reg_attr_obj == 0 || 1628 tx->tx_objset->os_sa->sa_layout_attr_obj == 0) { 1629 dmu_tx_hold_zap(tx, sa->sa_master_obj, B_TRUE, SA_LAYOUTS); 1630 dmu_tx_hold_zap(tx, sa->sa_master_obj, B_TRUE, SA_REGISTRY); 1631 dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, B_TRUE, NULL); 1632 dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, B_TRUE, NULL); 1633 } 1634 1635 dmu_tx_sa_registration_hold(sa, tx); 1636 1637 if (may_grow && tx->tx_objset->os_sa->sa_layout_attr_obj) 1638 dmu_tx_hold_zap(tx, sa->sa_layout_attr_obj, B_TRUE, NULL); 1639 1640 if (sa->sa_force_spill || may_grow || hdl->sa_spill) { 1641 ASSERT(tx->tx_txg == 0); 1642 dmu_tx_hold_spill(tx, object); 1643 } else { 1644 dmu_buf_impl_t *db = (dmu_buf_impl_t *)hdl->sa_bonus; 1645 dnode_t *dn; 1646 1647 DB_DNODE_ENTER(db); 1648 dn = DB_DNODE(db); 1649 if (dn->dn_have_spill) { 1650 ASSERT(tx->tx_txg == 0); 1651 dmu_tx_hold_spill(tx, object); 1652 } 1653 DB_DNODE_EXIT(db); 1654 } 1655} 1656