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) 2013 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 42 typedef void (*dmu_tx_hold_func_t)(dmu_tx_t *tx, struct dnode *dn, 43 uint64_t arg1, uint64_t arg2); 44 45 46 dmu_tx_t * 47 dmu_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 65 dmu_tx_t * 66 dmu_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 74 dmu_tx_t * 75 dmu_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 87 int 88 dmu_tx_is_syncing(dmu_tx_t *tx) 89 { 90 return (tx->tx_anyobj); 91 } 92 93 int 94 dmu_tx_private_ok(dmu_tx_t *tx) 95 { 96 return (tx->tx_anyobj); 97 } 98 99 static dmu_tx_hold_t * 100 dmu_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 } 140 141 void 142 dmu_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 } 153 154 static int 155 dmu_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 } 169 170 static void 171 dmu_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 */ 215 static void 216 dmu_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 = SPA_MAXBLOCKSHIFT; 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 } 297 298 /* 299 * If this write is not off the end of the file 300 * we need to account for overwrites/unref. 301 */ 302 if (start <= dn->dn_maxblkid) { 303 for (int l = 0; l < DN_MAX_LEVELS; l++) 304 history[l] = -1ULL; 305 } 306 while (start <= dn->dn_maxblkid) { 307 dmu_buf_impl_t *db; 308 309 rw_enter(&dn->dn_struct_rwlock, RW_READER); 310 err = dbuf_hold_impl(dn, 0, start, FALSE, FTAG, &db); 311 rw_exit(&dn->dn_struct_rwlock); 312 313 if (err) { 314 txh->txh_tx->tx_err = err; 315 return; 316 } 317 318 dmu_tx_count_twig(txh, dn, db, 0, start, B_FALSE, 319 history); 320 dbuf_rele(db, FTAG); 321 if (++start > end) { 322 /* 323 * Account for new indirects appearing 324 * before this IO gets assigned into a txg. 325 */ 326 bits = 64 - min_bs; 327 epbs = min_ibs - SPA_BLKPTRSHIFT; 328 for (bits -= epbs * (nlvls - 1); 329 bits >= 0; bits -= epbs) 330 txh->txh_fudge += 1ULL << max_ibs; 331 goto out; 332 } 333 off += delta; 334 if (len >= delta) 335 len -= delta; 336 delta = dn->dn_datablksz; 337 } 338 } 339 340 /* 341 * 'end' is the last thing we will access, not one past. 342 * This way we won't overflow when accessing the last byte. 343 */ 344 start = P2ALIGN(off, 1ULL << max_bs); 345 end = P2ROUNDUP(off + len, 1ULL << max_bs) - 1; 346 txh->txh_space_towrite += end - start + 1; 347 348 start >>= min_bs; 349 end >>= min_bs; 350 351 epbs = min_ibs - SPA_BLKPTRSHIFT; 352 353 /* 354 * The object contains at most 2^(64 - min_bs) blocks, 355 * and each indirect level maps 2^epbs. 356 */ 357 for (bits = 64 - min_bs; bits >= 0; bits -= epbs) { 358 start >>= epbs; 359 end >>= epbs; 360 ASSERT3U(end, >=, start); 361 txh->txh_space_towrite += (end - start + 1) << max_ibs; 362 if (start != 0) { 363 /* 364 * We also need a new blkid=0 indirect block 365 * to reference any existing file data. 366 */ 367 txh->txh_space_towrite += 1ULL << max_ibs; 368 } 369 } 370 371 out: 372 if (txh->txh_space_towrite + txh->txh_space_tooverwrite > 373 2 * DMU_MAX_ACCESS) 374 err = SET_ERROR(EFBIG); 375 376 if (err) 377 txh->txh_tx->tx_err = err; 378 } 379 380 static void 381 dmu_tx_count_dnode(dmu_tx_hold_t *txh) 382 { 383 dnode_t *dn = txh->txh_dnode; 384 dnode_t *mdn = DMU_META_DNODE(txh->txh_tx->tx_objset); 385 uint64_t space = mdn->dn_datablksz + 386 ((mdn->dn_nlevels-1) << mdn->dn_indblkshift); 387 388 if (dn && dn->dn_dbuf->db_blkptr && 389 dsl_dataset_block_freeable(dn->dn_objset->os_dsl_dataset, 390 dn->dn_dbuf->db_blkptr, dn->dn_dbuf->db_blkptr->blk_birth)) { 391 txh->txh_space_tooverwrite += space; 392 txh->txh_space_tounref += space; 393 } else { 394 txh->txh_space_towrite += space; 395 if (dn && dn->dn_dbuf->db_blkptr) 396 txh->txh_space_tounref += space; 397 } 398 } 399 400 void 401 dmu_tx_hold_write(dmu_tx_t *tx, uint64_t object, uint64_t off, int len) 402 { 403 dmu_tx_hold_t *txh; 404 405 ASSERT(tx->tx_txg == 0); 406 ASSERT(len < DMU_MAX_ACCESS); 407 ASSERT(len == 0 || UINT64_MAX - off >= len - 1); 408 409 txh = dmu_tx_hold_object_impl(tx, tx->tx_objset, 410 object, THT_WRITE, off, len); 411 if (txh == NULL) 412 return; 413 414 dmu_tx_count_write(txh, off, len); 415 dmu_tx_count_dnode(txh); 416 } 417 418 static void 419 dmu_tx_count_free(dmu_tx_hold_t *txh, uint64_t off, uint64_t len) 420 { 421 uint64_t blkid, nblks, lastblk; 422 uint64_t space = 0, unref = 0, skipped = 0; 423 dnode_t *dn = txh->txh_dnode; 424 dsl_dataset_t *ds = dn->dn_objset->os_dsl_dataset; 425 spa_t *spa = txh->txh_tx->tx_pool->dp_spa; 426 int epbs; 427 uint64_t l0span = 0, nl1blks = 0; 428 429 if (dn->dn_nlevels == 0) 430 return; 431 432 /* 433 * The struct_rwlock protects us against dn_nlevels 434 * changing, in case (against all odds) we manage to dirty & 435 * sync out the changes after we check for being dirty. 436 * Also, dbuf_hold_impl() wants us to have the struct_rwlock. 437 */ 438 rw_enter(&dn->dn_struct_rwlock, RW_READER); 439 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT; 440 if (dn->dn_maxblkid == 0) { 441 if (off == 0 && len >= dn->dn_datablksz) { 442 blkid = 0; 443 nblks = 1; 444 } else { 445 rw_exit(&dn->dn_struct_rwlock); 446 return; 447 } 448 } else { 449 blkid = off >> dn->dn_datablkshift; 450 nblks = (len + dn->dn_datablksz - 1) >> dn->dn_datablkshift; 451 452 if (blkid > dn->dn_maxblkid) { 453 rw_exit(&dn->dn_struct_rwlock); 454 return; 455 } 456 if (blkid + nblks > dn->dn_maxblkid) 457 nblks = dn->dn_maxblkid - blkid + 1; 458 459 } 460 l0span = nblks; /* save for later use to calc level > 1 overhead */ 461 if (dn->dn_nlevels == 1) { 462 int i; 463 for (i = 0; i < nblks; i++) { 464 blkptr_t *bp = dn->dn_phys->dn_blkptr; 465 ASSERT3U(blkid + i, <, dn->dn_nblkptr); 466 bp += blkid + i; 467 if (dsl_dataset_block_freeable(ds, bp, bp->blk_birth)) { 468 dprintf_bp(bp, "can free old%s", ""); 469 space += bp_get_dsize(spa, bp); 470 } 471 unref += BP_GET_ASIZE(bp); 472 } 473 nl1blks = 1; 474 nblks = 0; 475 } 476 477 lastblk = blkid + nblks - 1; 478 while (nblks) { 479 dmu_buf_impl_t *dbuf; 480 uint64_t ibyte, new_blkid; 481 int epb = 1 << epbs; 482 int err, i, blkoff, tochk; 483 blkptr_t *bp; 484 485 ibyte = blkid << dn->dn_datablkshift; 486 err = dnode_next_offset(dn, 487 DNODE_FIND_HAVELOCK, &ibyte, 2, 1, 0); 488 new_blkid = ibyte >> dn->dn_datablkshift; 489 if (err == ESRCH) { 490 skipped += (lastblk >> epbs) - (blkid >> epbs) + 1; 491 break; 492 } 493 if (err) { 494 txh->txh_tx->tx_err = err; 495 break; 496 } 497 if (new_blkid > lastblk) { 498 skipped += (lastblk >> epbs) - (blkid >> epbs) + 1; 499 break; 500 } 501 502 if (new_blkid > blkid) { 503 ASSERT((new_blkid >> epbs) > (blkid >> epbs)); 504 skipped += (new_blkid >> epbs) - (blkid >> epbs) - 1; 505 nblks -= new_blkid - blkid; 506 blkid = new_blkid; 507 } 508 blkoff = P2PHASE(blkid, epb); 509 tochk = MIN(epb - blkoff, nblks); 510 511 err = dbuf_hold_impl(dn, 1, blkid >> epbs, FALSE, FTAG, &dbuf); 512 if (err) { 513 txh->txh_tx->tx_err = err; 514 break; 515 } 516 517 txh->txh_memory_tohold += dbuf->db.db_size; 518 519 /* 520 * We don't check memory_tohold against DMU_MAX_ACCESS because 521 * memory_tohold is an over-estimation (especially the >L1 522 * indirect blocks), so it could fail. Callers should have 523 * already verified that they will not be holding too much 524 * memory. 525 */ 526 527 err = dbuf_read(dbuf, NULL, DB_RF_HAVESTRUCT | DB_RF_CANFAIL); 528 if (err != 0) { 529 txh->txh_tx->tx_err = err; 530 dbuf_rele(dbuf, FTAG); 531 break; 532 } 533 534 bp = dbuf->db.db_data; 535 bp += blkoff; 536 537 for (i = 0; i < tochk; i++) { 538 if (dsl_dataset_block_freeable(ds, &bp[i], 539 bp[i].blk_birth)) { 540 dprintf_bp(&bp[i], "can free old%s", ""); 541 space += bp_get_dsize(spa, &bp[i]); 542 } 543 unref += BP_GET_ASIZE(bp); 544 } 545 dbuf_rele(dbuf, FTAG); 546 547 ++nl1blks; 548 blkid += tochk; 549 nblks -= tochk; 550 } 551 rw_exit(&dn->dn_struct_rwlock); 552 553 /* 554 * Add in memory requirements of higher-level indirects. 555 * This assumes a worst-possible scenario for dn_nlevels and a 556 * worst-possible distribution of l1-blocks over the region to free. 557 */ 558 { 559 uint64_t blkcnt = 1 + ((l0span >> epbs) >> epbs); 560 int level = 2; 561 /* 562 * Here we don't use DN_MAX_LEVEL, but calculate it with the 563 * given datablkshift and indblkshift. This makes the 564 * difference between 19 and 8 on large files. 565 */ 566 int maxlevel = 2 + (DN_MAX_OFFSET_SHIFT - dn->dn_datablkshift) / 567 (dn->dn_indblkshift - SPA_BLKPTRSHIFT); 568 569 while (level++ < maxlevel) { 570 txh->txh_memory_tohold += MAX(MIN(blkcnt, nl1blks), 1) 571 << dn->dn_indblkshift; 572 blkcnt = 1 + (blkcnt >> epbs); 573 } 574 } 575 576 /* account for new level 1 indirect blocks that might show up */ 577 if (skipped > 0) { 578 txh->txh_fudge += skipped << dn->dn_indblkshift; 579 skipped = MIN(skipped, DMU_MAX_DELETEBLKCNT >> epbs); 580 txh->txh_memory_tohold += skipped << dn->dn_indblkshift; 581 } 582 txh->txh_space_tofree += space; 583 txh->txh_space_tounref += unref; 584 } 585 586 void 587 dmu_tx_hold_free(dmu_tx_t *tx, uint64_t object, uint64_t off, uint64_t len) 588 { 589 dmu_tx_hold_t *txh; 590 dnode_t *dn; 591 int err; 592 zio_t *zio; 593 594 ASSERT(tx->tx_txg == 0); 595 596 txh = dmu_tx_hold_object_impl(tx, tx->tx_objset, 597 object, THT_FREE, off, len); 598 if (txh == NULL) 599 return; 600 dn = txh->txh_dnode; 601 dmu_tx_count_dnode(txh); 602 603 if (off >= (dn->dn_maxblkid+1) * dn->dn_datablksz) 604 return; 605 if (len == DMU_OBJECT_END) 606 len = (dn->dn_maxblkid+1) * dn->dn_datablksz - off; 607 608 609 /* 610 * For i/o error checking, we read the first and last level-0 611 * blocks if they are not aligned, and all the level-1 blocks. 612 * 613 * Note: dbuf_free_range() assumes that we have not instantiated 614 * any level-0 dbufs that will be completely freed. Therefore we must 615 * exercise care to not read or count the first and last blocks 616 * if they are blocksize-aligned. 617 */ 618 if (dn->dn_datablkshift == 0) { 619 if (off != 0 || len < dn->dn_datablksz) 620 dmu_tx_count_write(txh, off, len); 621 } else { 622 /* first block will be modified if it is not aligned */ 623 if (!IS_P2ALIGNED(off, 1 << dn->dn_datablkshift)) 624 dmu_tx_count_write(txh, off, 1); 625 /* last block will be modified if it is not aligned */ 626 if (!IS_P2ALIGNED(off + len, 1 << dn->dn_datablkshift)) 627 dmu_tx_count_write(txh, off+len, 1); 628 } 629 630 /* 631 * Check level-1 blocks. 632 */ 633 if (dn->dn_nlevels > 1) { 634 int shift = dn->dn_datablkshift + dn->dn_indblkshift - 635 SPA_BLKPTRSHIFT; 636 uint64_t start = off >> shift; 637 uint64_t end = (off + len) >> shift; 638 639 ASSERT(dn->dn_datablkshift != 0); 640 ASSERT(dn->dn_indblkshift != 0); 641 642 zio = zio_root(tx->tx_pool->dp_spa, 643 NULL, NULL, ZIO_FLAG_CANFAIL); 644 for (uint64_t i = start; i <= end; i++) { 645 uint64_t ibyte = i << shift; 646 err = dnode_next_offset(dn, 0, &ibyte, 2, 1, 0); 647 i = ibyte >> shift; 648 if (err == ESRCH) 649 break; 650 if (err) { 651 tx->tx_err = err; 652 return; 653 } 654 655 err = dmu_tx_check_ioerr(zio, dn, 1, i); 656 if (err) { 657 tx->tx_err = err; 658 return; 659 } 660 } 661 err = zio_wait(zio); 662 if (err) { 663 tx->tx_err = err; 664 return; 665 } 666 } 667 668 dmu_tx_count_free(txh, off, len); 669 } 670 671 void 672 dmu_tx_hold_zap(dmu_tx_t *tx, uint64_t object, int add, const char *name) 673 { 674 dmu_tx_hold_t *txh; 675 dnode_t *dn; 676 uint64_t nblocks; 677 int epbs, err; 678 679 ASSERT(tx->tx_txg == 0); 680 681 txh = dmu_tx_hold_object_impl(tx, tx->tx_objset, 682 object, THT_ZAP, add, (uintptr_t)name); 683 if (txh == NULL) 684 return; 685 dn = txh->txh_dnode; 686 687 dmu_tx_count_dnode(txh); 688 689 if (dn == NULL) { 690 /* 691 * We will be able to fit a new object's entries into one leaf 692 * block. So there will be at most 2 blocks total, 693 * including the header block. 694 */ 695 dmu_tx_count_write(txh, 0, 2 << fzap_default_block_shift); 696 return; 697 } 698 699 ASSERT3P(DMU_OT_BYTESWAP(dn->dn_type), ==, DMU_BSWAP_ZAP); 700 701 if (dn->dn_maxblkid == 0 && !add) { 702 blkptr_t *bp; 703 704 /* 705 * If there is only one block (i.e. this is a micro-zap) 706 * and we are not adding anything, the accounting is simple. 707 */ 708 err = dmu_tx_check_ioerr(NULL, dn, 0, 0); 709 if (err) { 710 tx->tx_err = err; 711 return; 712 } 713 714 /* 715 * Use max block size here, since we don't know how much 716 * the size will change between now and the dbuf dirty call. 717 */ 718 bp = &dn->dn_phys->dn_blkptr[0]; 719 if (dsl_dataset_block_freeable(dn->dn_objset->os_dsl_dataset, 720 bp, bp->blk_birth)) 721 txh->txh_space_tooverwrite += SPA_MAXBLOCKSIZE; 722 else 723 txh->txh_space_towrite += SPA_MAXBLOCKSIZE; 724 if (!BP_IS_HOLE(bp)) 725 txh->txh_space_tounref += SPA_MAXBLOCKSIZE; 726 return; 727 } 728 729 if (dn->dn_maxblkid > 0 && name) { 730 /* 731 * access the name in this fat-zap so that we'll check 732 * for i/o errors to the leaf blocks, etc. 733 */ 734 err = zap_lookup(dn->dn_objset, dn->dn_object, name, 735 8, 0, NULL); 736 if (err == EIO) { 737 tx->tx_err = err; 738 return; 739 } 740 } 741 742 err = zap_count_write(dn->dn_objset, dn->dn_object, name, add, 743 &txh->txh_space_towrite, &txh->txh_space_tooverwrite); 744 745 /* 746 * If the modified blocks are scattered to the four winds, 747 * we'll have to modify an indirect twig for each. 748 */ 749 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT; 750 for (nblocks = dn->dn_maxblkid >> epbs; nblocks != 0; nblocks >>= epbs) 751 if (dn->dn_objset->os_dsl_dataset->ds_phys->ds_prev_snap_obj) 752 txh->txh_space_towrite += 3 << dn->dn_indblkshift; 753 else 754 txh->txh_space_tooverwrite += 3 << dn->dn_indblkshift; 755 } 756 757 void 758 dmu_tx_hold_bonus(dmu_tx_t *tx, uint64_t object) 759 { 760 dmu_tx_hold_t *txh; 761 762 ASSERT(tx->tx_txg == 0); 763 764 txh = dmu_tx_hold_object_impl(tx, tx->tx_objset, 765 object, THT_BONUS, 0, 0); 766 if (txh) 767 dmu_tx_count_dnode(txh); 768 } 769 770 void 771 dmu_tx_hold_space(dmu_tx_t *tx, uint64_t space) 772 { 773 dmu_tx_hold_t *txh; 774 ASSERT(tx->tx_txg == 0); 775 776 txh = dmu_tx_hold_object_impl(tx, tx->tx_objset, 777 DMU_NEW_OBJECT, THT_SPACE, space, 0); 778 779 txh->txh_space_towrite += space; 780 } 781 782 int 783 dmu_tx_holds(dmu_tx_t *tx, uint64_t object) 784 { 785 dmu_tx_hold_t *txh; 786 int holds = 0; 787 788 /* 789 * By asserting that the tx is assigned, we're counting the 790 * number of dn_tx_holds, which is the same as the number of 791 * dn_holds. Otherwise, we'd be counting dn_holds, but 792 * dn_tx_holds could be 0. 793 */ 794 ASSERT(tx->tx_txg != 0); 795 796 /* if (tx->tx_anyobj == TRUE) */ 797 /* return (0); */ 798 799 for (txh = list_head(&tx->tx_holds); txh; 800 txh = list_next(&tx->tx_holds, txh)) { 801 if (txh->txh_dnode && txh->txh_dnode->dn_object == object) 802 holds++; 803 } 804 805 return (holds); 806 } 807 808 #ifdef ZFS_DEBUG 809 void 810 dmu_tx_dirty_buf(dmu_tx_t *tx, dmu_buf_impl_t *db) 811 { 812 dmu_tx_hold_t *txh; 813 int match_object = FALSE, match_offset = FALSE; 814 dnode_t *dn; 815 816 DB_DNODE_ENTER(db); 817 dn = DB_DNODE(db); 818 ASSERT(tx->tx_txg != 0); 819 ASSERT(tx->tx_objset == NULL || dn->dn_objset == tx->tx_objset); 820 ASSERT3U(dn->dn_object, ==, db->db.db_object); 821 822 if (tx->tx_anyobj) { 823 DB_DNODE_EXIT(db); 824 return; 825 } 826 827 /* XXX No checking on the meta dnode for now */ 828 if (db->db.db_object == DMU_META_DNODE_OBJECT) { 829 DB_DNODE_EXIT(db); 830 return; 831 } 832 833 for (txh = list_head(&tx->tx_holds); txh; 834 txh = list_next(&tx->tx_holds, txh)) { 835 ASSERT(dn == NULL || dn->dn_assigned_txg == tx->tx_txg); 836 if (txh->txh_dnode == dn && txh->txh_type != THT_NEWOBJECT) 837 match_object = TRUE; 838 if (txh->txh_dnode == NULL || txh->txh_dnode == dn) { 839 int datablkshift = dn->dn_datablkshift ? 840 dn->dn_datablkshift : SPA_MAXBLOCKSHIFT; 841 int epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT; 842 int shift = datablkshift + epbs * db->db_level; 843 uint64_t beginblk = shift >= 64 ? 0 : 844 (txh->txh_arg1 >> shift); 845 uint64_t endblk = shift >= 64 ? 0 : 846 ((txh->txh_arg1 + txh->txh_arg2 - 1) >> shift); 847 uint64_t blkid = db->db_blkid; 848 849 /* XXX txh_arg2 better not be zero... */ 850 851 dprintf("found txh type %x beginblk=%llx endblk=%llx\n", 852 txh->txh_type, beginblk, endblk); 853 854 switch (txh->txh_type) { 855 case THT_WRITE: 856 if (blkid >= beginblk && blkid <= endblk) 857 match_offset = TRUE; 858 /* 859 * We will let this hold work for the bonus 860 * or spill buffer so that we don't need to 861 * hold it when creating a new object. 862 */ 863 if (blkid == DMU_BONUS_BLKID || 864 blkid == DMU_SPILL_BLKID) 865 match_offset = TRUE; 866 /* 867 * They might have to increase nlevels, 868 * thus dirtying the new TLIBs. Or the 869 * might have to change the block size, 870 * thus dirying the new lvl=0 blk=0. 871 */ 872 if (blkid == 0) 873 match_offset = TRUE; 874 break; 875 case THT_FREE: 876 /* 877 * We will dirty all the level 1 blocks in 878 * the free range and perhaps the first and 879 * last level 0 block. 880 */ 881 if (blkid >= beginblk && (blkid <= endblk || 882 txh->txh_arg2 == DMU_OBJECT_END)) 883 match_offset = TRUE; 884 break; 885 case THT_SPILL: 886 if (blkid == DMU_SPILL_BLKID) 887 match_offset = TRUE; 888 break; 889 case THT_BONUS: 890 if (blkid == DMU_BONUS_BLKID) 891 match_offset = TRUE; 892 break; 893 case THT_ZAP: 894 match_offset = TRUE; 895 break; 896 case THT_NEWOBJECT: 897 match_object = TRUE; 898 break; 899 default: 900 ASSERT(!"bad txh_type"); 901 } 902 } 903 if (match_object && match_offset) { 904 DB_DNODE_EXIT(db); 905 return; 906 } 907 } 908 DB_DNODE_EXIT(db); 909 panic("dirtying dbuf obj=%llx lvl=%u blkid=%llx but not tx_held\n", 910 (u_longlong_t)db->db.db_object, db->db_level, 911 (u_longlong_t)db->db_blkid); 912 } 913 #endif 914 915 /* 916 * If we can't do 10 iops, something is wrong. Let us go ahead 917 * and hit zfs_dirty_data_max. 918 */ 919 hrtime_t zfs_delay_max_ns = MSEC2NSEC(100); 920 int zfs_delay_resolution_ns = 100 * 1000; /* 100 microseconds */ 921 922 /* 923 * We delay transactions when we've determined that the backend storage 924 * isn't able to accommodate the rate of incoming writes. 925 * 926 * If there is already a transaction waiting, we delay relative to when 927 * that transaction finishes waiting. This way the calculated min_time 928 * is independent of the number of threads concurrently executing 929 * transactions. 930 * 931 * If we are the only waiter, wait relative to when the transaction 932 * started, rather than the current time. This credits the transaction for 933 * "time already served", e.g. reading indirect blocks. 934 * 935 * The minimum time for a transaction to take is calculated as: 936 * min_time = scale * (dirty - min) / (max - dirty) 937 * min_time is then capped at zfs_delay_max_ns. 938 * 939 * The delay has two degrees of freedom that can be adjusted via tunables. 940 * The percentage of dirty data at which we start to delay is defined by 941 * zfs_delay_min_dirty_percent. This should typically be at or above 942 * zfs_vdev_async_write_active_max_dirty_percent so that we only start to 943 * delay after writing at full speed has failed to keep up with the incoming 944 * write rate. The scale of the curve is defined by zfs_delay_scale. Roughly 945 * speaking, this variable determines the amount of delay at the midpoint of 946 * the curve. 947 * 948 * delay 949 * 10ms +-------------------------------------------------------------*+ 950 * | *| 951 * 9ms + *+ 952 * | *| 953 * 8ms + *+ 954 * | * | 955 * 7ms + * + 956 * | * | 957 * 6ms + * + 958 * | * | 959 * 5ms + * + 960 * | * | 961 * 4ms + * + 962 * | * | 963 * 3ms + * + 964 * | * | 965 * 2ms + (midpoint) * + 966 * | | ** | 967 * 1ms + v *** + 968 * | zfs_delay_scale ----------> ******** | 969 * 0 +-------------------------------------*********----------------+ 970 * 0% <- zfs_dirty_data_max -> 100% 971 * 972 * Note that since the delay is added to the outstanding time remaining on the 973 * most recent transaction, the delay is effectively the inverse of IOPS. 974 * Here the midpoint of 500us translates to 2000 IOPS. The shape of the curve 975 * was chosen such that small changes in the amount of accumulated dirty data 976 * in the first 3/4 of the curve yield relatively small differences in the 977 * amount of delay. 978 * 979 * The effects can be easier to understand when the amount of delay is 980 * represented on a log scale: 981 * 982 * delay 983 * 100ms +-------------------------------------------------------------++ 984 * + + 985 * | | 986 * + *+ 987 * 10ms + *+ 988 * + ** + 989 * | (midpoint) ** | 990 * + | ** + 991 * 1ms + v **** + 992 * + zfs_delay_scale ----------> ***** + 993 * | **** | 994 * + **** + 995 * 100us + ** + 996 * + * + 997 * | * | 998 * + * + 999 * 10us + * + 1000 * + + 1001 * | | 1002 * + + 1003 * +--------------------------------------------------------------+ 1004 * 0% <- zfs_dirty_data_max -> 100% 1005 * 1006 * Note here that only as the amount of dirty data approaches its limit does 1007 * the delay start to increase rapidly. The goal of a properly tuned system 1008 * should be to keep the amount of dirty data out of that range by first 1009 * ensuring that the appropriate limits are set for the I/O scheduler to reach 1010 * optimal throughput on the backend storage, and then by changing the value 1011 * of zfs_delay_scale to increase the steepness of the curve. 1012 */ 1013 static void 1014 dmu_tx_delay(dmu_tx_t *tx, uint64_t dirty) 1015 { 1016 dsl_pool_t *dp = tx->tx_pool; 1017 uint64_t delay_min_bytes = 1018 zfs_dirty_data_max * zfs_delay_min_dirty_percent / 100; 1019 hrtime_t wakeup, min_tx_time, now; 1020 1021 if (dirty <= delay_min_bytes) 1022 return; 1023 1024 /* 1025 * The caller has already waited until we are under the max. 1026 * We make them pass us the amount of dirty data so we don't 1027 * have to handle the case of it being >= the max, which could 1028 * cause a divide-by-zero if it's == the max. 1029 */ 1030 ASSERT3U(dirty, <, zfs_dirty_data_max); 1031 1032 now = gethrtime(); 1033 min_tx_time = zfs_delay_scale * 1034 (dirty - delay_min_bytes) / (zfs_dirty_data_max - dirty); 1035 if (now > tx->tx_start + min_tx_time) 1036 return; 1037 1038 min_tx_time = MIN(min_tx_time, zfs_delay_max_ns); 1039 1040 DTRACE_PROBE3(delay__mintime, dmu_tx_t *, tx, uint64_t, dirty, 1041 uint64_t, min_tx_time); 1042 1043 mutex_enter(&dp->dp_lock); 1044 wakeup = MAX(tx->tx_start + min_tx_time, 1045 dp->dp_last_wakeup + min_tx_time); 1046 dp->dp_last_wakeup = wakeup; 1047 mutex_exit(&dp->dp_lock); 1048 1049 #ifdef _KERNEL 1050 mutex_enter(&curthread->t_delay_lock); 1051 while (cv_timedwait_hires(&curthread->t_delay_cv, 1052 &curthread->t_delay_lock, wakeup, zfs_delay_resolution_ns, 1053 CALLOUT_FLAG_ABSOLUTE | CALLOUT_FLAG_ROUNDUP) > 0) 1054 continue; 1055 mutex_exit(&curthread->t_delay_lock); 1056 #else 1057 hrtime_t delta = wakeup - gethrtime(); 1058 struct timespec ts; 1059 ts.tv_sec = delta / NANOSEC; 1060 ts.tv_nsec = delta % NANOSEC; 1061 (void) nanosleep(&ts, NULL); 1062 #endif 1063 } 1064 1065 static int 1066 dmu_tx_try_assign(dmu_tx_t *tx, txg_how_t txg_how) 1067 { 1068 dmu_tx_hold_t *txh; 1069 spa_t *spa = tx->tx_pool->dp_spa; 1070 uint64_t memory, asize, fsize, usize; 1071 uint64_t towrite, tofree, tooverwrite, tounref, tohold, fudge; 1072 1073 ASSERT0(tx->tx_txg); 1074 1075 if (tx->tx_err) 1076 return (tx->tx_err); 1077 1078 if (spa_suspended(spa)) { 1079 /* 1080 * If the user has indicated a blocking failure mode 1081 * then return ERESTART which will block in dmu_tx_wait(). 1082 * Otherwise, return EIO so that an error can get 1083 * propagated back to the VOP calls. 1084 * 1085 * Note that we always honor the txg_how flag regardless 1086 * of the failuremode setting. 1087 */ 1088 if (spa_get_failmode(spa) == ZIO_FAILURE_MODE_CONTINUE && 1089 txg_how != TXG_WAIT) 1090 return (SET_ERROR(EIO)); 1091 1092 return (SET_ERROR(ERESTART)); 1093 } 1094 1095 if (!tx->tx_waited && 1096 dsl_pool_need_dirty_delay(tx->tx_pool)) { 1097 tx->tx_wait_dirty = B_TRUE; 1098 return (SET_ERROR(ERESTART)); 1099 } 1100 1101 tx->tx_txg = txg_hold_open(tx->tx_pool, &tx->tx_txgh); 1102 tx->tx_needassign_txh = NULL; 1103 1104 /* 1105 * NB: No error returns are allowed after txg_hold_open, but 1106 * before processing the dnode holds, due to the 1107 * dmu_tx_unassign() logic. 1108 */ 1109 1110 towrite = tofree = tooverwrite = tounref = tohold = fudge = 0; 1111 for (txh = list_head(&tx->tx_holds); txh; 1112 txh = list_next(&tx->tx_holds, txh)) { 1113 dnode_t *dn = txh->txh_dnode; 1114 if (dn != NULL) { 1115 mutex_enter(&dn->dn_mtx); 1116 if (dn->dn_assigned_txg == tx->tx_txg - 1) { 1117 mutex_exit(&dn->dn_mtx); 1118 tx->tx_needassign_txh = txh; 1119 return (SET_ERROR(ERESTART)); 1120 } 1121 if (dn->dn_assigned_txg == 0) 1122 dn->dn_assigned_txg = tx->tx_txg; 1123 ASSERT3U(dn->dn_assigned_txg, ==, tx->tx_txg); 1124 (void) refcount_add(&dn->dn_tx_holds, tx); 1125 mutex_exit(&dn->dn_mtx); 1126 } 1127 towrite += txh->txh_space_towrite; 1128 tofree += txh->txh_space_tofree; 1129 tooverwrite += txh->txh_space_tooverwrite; 1130 tounref += txh->txh_space_tounref; 1131 tohold += txh->txh_memory_tohold; 1132 fudge += txh->txh_fudge; 1133 } 1134 1135 /* 1136 * If a snapshot has been taken since we made our estimates, 1137 * assume that we won't be able to free or overwrite anything. 1138 */ 1139 if (tx->tx_objset && 1140 dsl_dataset_prev_snap_txg(tx->tx_objset->os_dsl_dataset) > 1141 tx->tx_lastsnap_txg) { 1142 towrite += tooverwrite; 1143 tooverwrite = tofree = 0; 1144 } 1145 1146 /* needed allocation: worst-case estimate of write space */ 1147 asize = spa_get_asize(tx->tx_pool->dp_spa, towrite + tooverwrite); 1148 /* freed space estimate: worst-case overwrite + free estimate */ 1149 fsize = spa_get_asize(tx->tx_pool->dp_spa, tooverwrite) + tofree; 1150 /* convert unrefd space to worst-case estimate */ 1151 usize = spa_get_asize(tx->tx_pool->dp_spa, tounref); 1152 /* calculate memory footprint estimate */ 1153 memory = towrite + tooverwrite + tohold; 1154 1155 #ifdef ZFS_DEBUG 1156 /* 1157 * Add in 'tohold' to account for our dirty holds on this memory 1158 * XXX - the "fudge" factor is to account for skipped blocks that 1159 * we missed because dnode_next_offset() misses in-core-only blocks. 1160 */ 1161 tx->tx_space_towrite = asize + 1162 spa_get_asize(tx->tx_pool->dp_spa, tohold + fudge); 1163 tx->tx_space_tofree = tofree; 1164 tx->tx_space_tooverwrite = tooverwrite; 1165 tx->tx_space_tounref = tounref; 1166 #endif 1167 1168 if (tx->tx_dir && asize != 0) { 1169 int err = dsl_dir_tempreserve_space(tx->tx_dir, memory, 1170 asize, fsize, usize, &tx->tx_tempreserve_cookie, tx); 1171 if (err) 1172 return (err); 1173 } 1174 1175 return (0); 1176 } 1177 1178 static void 1179 dmu_tx_unassign(dmu_tx_t *tx) 1180 { 1181 dmu_tx_hold_t *txh; 1182 1183 if (tx->tx_txg == 0) 1184 return; 1185 1186 txg_rele_to_quiesce(&tx->tx_txgh); 1187 1188 /* 1189 * Walk the transaction's hold list, removing the hold on the 1190 * associated dnode, and notifying waiters if the refcount drops to 0. 1191 */ 1192 for (txh = list_head(&tx->tx_holds); txh != tx->tx_needassign_txh; 1193 txh = list_next(&tx->tx_holds, txh)) { 1194 dnode_t *dn = txh->txh_dnode; 1195 1196 if (dn == NULL) 1197 continue; 1198 mutex_enter(&dn->dn_mtx); 1199 ASSERT3U(dn->dn_assigned_txg, ==, tx->tx_txg); 1200 1201 if (refcount_remove(&dn->dn_tx_holds, tx) == 0) { 1202 dn->dn_assigned_txg = 0; 1203 cv_broadcast(&dn->dn_notxholds); 1204 } 1205 mutex_exit(&dn->dn_mtx); 1206 } 1207 1208 txg_rele_to_sync(&tx->tx_txgh); 1209 1210 tx->tx_lasttried_txg = tx->tx_txg; 1211 tx->tx_txg = 0; 1212 } 1213 1214 /* 1215 * Assign tx to a transaction group. txg_how can be one of: 1216 * 1217 * (1) TXG_WAIT. If the current open txg is full, waits until there's 1218 * a new one. This should be used when you're not holding locks. 1219 * It will only fail if we're truly out of space (or over quota). 1220 * 1221 * (2) TXG_NOWAIT. If we can't assign into the current open txg without 1222 * blocking, returns immediately with ERESTART. This should be used 1223 * whenever you're holding locks. On an ERESTART error, the caller 1224 * should drop locks, do a dmu_tx_wait(tx), and try again. 1225 * 1226 * (3) TXG_WAITED. Like TXG_NOWAIT, but indicates that dmu_tx_wait() 1227 * has already been called on behalf of this operation (though 1228 * most likely on a different tx). 1229 */ 1230 int 1231 dmu_tx_assign(dmu_tx_t *tx, txg_how_t txg_how) 1232 { 1233 int err; 1234 1235 ASSERT(tx->tx_txg == 0); 1236 ASSERT(txg_how == TXG_WAIT || txg_how == TXG_NOWAIT || 1237 txg_how == TXG_WAITED); 1238 ASSERT(!dsl_pool_sync_context(tx->tx_pool)); 1239 1240 /* If we might wait, we must not hold the config lock. */ 1241 ASSERT(txg_how != TXG_WAIT || !dsl_pool_config_held(tx->tx_pool)); 1242 1243 if (txg_how == TXG_WAITED) 1244 tx->tx_waited = B_TRUE; 1245 1246 while ((err = dmu_tx_try_assign(tx, txg_how)) != 0) { 1247 dmu_tx_unassign(tx); 1248 1249 if (err != ERESTART || txg_how != TXG_WAIT) 1250 return (err); 1251 1252 dmu_tx_wait(tx); 1253 } 1254 1255 txg_rele_to_quiesce(&tx->tx_txgh); 1256 1257 return (0); 1258 } 1259 1260 void 1261 dmu_tx_wait(dmu_tx_t *tx) 1262 { 1263 spa_t *spa = tx->tx_pool->dp_spa; 1264 dsl_pool_t *dp = tx->tx_pool; 1265 1266 ASSERT(tx->tx_txg == 0); 1267 ASSERT(!dsl_pool_config_held(tx->tx_pool)); 1268 1269 if (tx->tx_wait_dirty) { 1270 /* 1271 * dmu_tx_try_assign() has determined that we need to wait 1272 * because we've consumed much or all of the dirty buffer 1273 * space. 1274 */ 1275 mutex_enter(&dp->dp_lock); 1276 while (dp->dp_dirty_total >= zfs_dirty_data_max) 1277 cv_wait(&dp->dp_spaceavail_cv, &dp->dp_lock); 1278 uint64_t dirty = dp->dp_dirty_total; 1279 mutex_exit(&dp->dp_lock); 1280 1281 dmu_tx_delay(tx, dirty); 1282 1283 tx->tx_wait_dirty = B_FALSE; 1284 1285 /* 1286 * Note: setting tx_waited only has effect if the caller 1287 * used TX_WAIT. Otherwise they are going to destroy 1288 * this tx and try again. The common case, zfs_write(), 1289 * uses TX_WAIT. 1290 */ 1291 tx->tx_waited = B_TRUE; 1292 } else if (spa_suspended(spa) || tx->tx_lasttried_txg == 0) { 1293 /* 1294 * If the pool is suspended we need to wait until it 1295 * is resumed. Note that it's possible that the pool 1296 * has become active after this thread has tried to 1297 * obtain a tx. If that's the case then tx_lasttried_txg 1298 * would not have been set. 1299 */ 1300 txg_wait_synced(dp, spa_last_synced_txg(spa) + 1); 1301 } else if (tx->tx_needassign_txh) { 1302 /* 1303 * A dnode is assigned to the quiescing txg. Wait for its 1304 * transaction to complete. 1305 */ 1306 dnode_t *dn = tx->tx_needassign_txh->txh_dnode; 1307 1308 mutex_enter(&dn->dn_mtx); 1309 while (dn->dn_assigned_txg == tx->tx_lasttried_txg - 1) 1310 cv_wait(&dn->dn_notxholds, &dn->dn_mtx); 1311 mutex_exit(&dn->dn_mtx); 1312 tx->tx_needassign_txh = NULL; 1313 } else { 1314 txg_wait_open(tx->tx_pool, tx->tx_lasttried_txg + 1); 1315 } 1316 } 1317 1318 void 1319 dmu_tx_willuse_space(dmu_tx_t *tx, int64_t delta) 1320 { 1321 #ifdef ZFS_DEBUG 1322 if (tx->tx_dir == NULL || delta == 0) 1323 return; 1324 1325 if (delta > 0) { 1326 ASSERT3U(refcount_count(&tx->tx_space_written) + delta, <=, 1327 tx->tx_space_towrite); 1328 (void) refcount_add_many(&tx->tx_space_written, delta, NULL); 1329 } else { 1330 (void) refcount_add_many(&tx->tx_space_freed, -delta, NULL); 1331 } 1332 #endif 1333 } 1334 1335 void 1336 dmu_tx_commit(dmu_tx_t *tx) 1337 { 1338 dmu_tx_hold_t *txh; 1339 1340 ASSERT(tx->tx_txg != 0); 1341 1342 /* 1343 * Go through the transaction's hold list and remove holds on 1344 * associated dnodes, notifying waiters if no holds remain. 1345 */ 1346 while (txh = list_head(&tx->tx_holds)) { 1347 dnode_t *dn = txh->txh_dnode; 1348 1349 list_remove(&tx->tx_holds, txh); 1350 kmem_free(txh, sizeof (dmu_tx_hold_t)); 1351 if (dn == NULL) 1352 continue; 1353 mutex_enter(&dn->dn_mtx); 1354 ASSERT3U(dn->dn_assigned_txg, ==, tx->tx_txg); 1355 1356 if (refcount_remove(&dn->dn_tx_holds, tx) == 0) { 1357 dn->dn_assigned_txg = 0; 1358 cv_broadcast(&dn->dn_notxholds); 1359 } 1360 mutex_exit(&dn->dn_mtx); 1361 dnode_rele(dn, tx); 1362 } 1363 1364 if (tx->tx_tempreserve_cookie) 1365 dsl_dir_tempreserve_clear(tx->tx_tempreserve_cookie, tx); 1366 1367 if (!list_is_empty(&tx->tx_callbacks)) 1368 txg_register_callbacks(&tx->tx_txgh, &tx->tx_callbacks); 1369 1370 if (tx->tx_anyobj == FALSE) 1371 txg_rele_to_sync(&tx->tx_txgh); 1372 1373 list_destroy(&tx->tx_callbacks); 1374 list_destroy(&tx->tx_holds); 1375 #ifdef ZFS_DEBUG 1376 dprintf("towrite=%llu written=%llu tofree=%llu freed=%llu\n", 1377 tx->tx_space_towrite, refcount_count(&tx->tx_space_written), 1378 tx->tx_space_tofree, refcount_count(&tx->tx_space_freed)); 1379 refcount_destroy_many(&tx->tx_space_written, 1380 refcount_count(&tx->tx_space_written)); 1381 refcount_destroy_many(&tx->tx_space_freed, 1382 refcount_count(&tx->tx_space_freed)); 1383 #endif 1384 kmem_free(tx, sizeof (dmu_tx_t)); 1385 } 1386 1387 void 1388 dmu_tx_abort(dmu_tx_t *tx) 1389 { 1390 dmu_tx_hold_t *txh; 1391 1392 ASSERT(tx->tx_txg == 0); 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 dnode_rele(dn, tx); 1401 } 1402 1403 /* 1404 * Call any registered callbacks with an error code. 1405 */ 1406 if (!list_is_empty(&tx->tx_callbacks)) 1407 dmu_tx_do_callbacks(&tx->tx_callbacks, ECANCELED); 1408 1409 list_destroy(&tx->tx_callbacks); 1410 list_destroy(&tx->tx_holds); 1411 #ifdef ZFS_DEBUG 1412 refcount_destroy_many(&tx->tx_space_written, 1413 refcount_count(&tx->tx_space_written)); 1414 refcount_destroy_many(&tx->tx_space_freed, 1415 refcount_count(&tx->tx_space_freed)); 1416 #endif 1417 kmem_free(tx, sizeof (dmu_tx_t)); 1418 } 1419 1420 uint64_t 1421 dmu_tx_get_txg(dmu_tx_t *tx) 1422 { 1423 ASSERT(tx->tx_txg != 0); 1424 return (tx->tx_txg); 1425 } 1426 1427 dsl_pool_t * 1428 dmu_tx_pool(dmu_tx_t *tx) 1429 { 1430 ASSERT(tx->tx_pool != NULL); 1431 return (tx->tx_pool); 1432 } 1433 1434 1435 void 1436 dmu_tx_callback_register(dmu_tx_t *tx, dmu_tx_callback_func_t *func, void *data) 1437 { 1438 dmu_tx_callback_t *dcb; 1439 1440 dcb = kmem_alloc(sizeof (dmu_tx_callback_t), KM_SLEEP); 1441 1442 dcb->dcb_func = func; 1443 dcb->dcb_data = data; 1444 1445 list_insert_tail(&tx->tx_callbacks, dcb); 1446 } 1447 1448 /* 1449 * Call all the commit callbacks on a list, with a given error code. 1450 */ 1451 void 1452 dmu_tx_do_callbacks(list_t *cb_list, int error) 1453 { 1454 dmu_tx_callback_t *dcb; 1455 1456 while (dcb = list_head(cb_list)) { 1457 list_remove(cb_list, dcb); 1458 dcb->dcb_func(dcb->dcb_data, error); 1459 kmem_free(dcb, sizeof (dmu_tx_callback_t)); 1460 } 1461 } 1462 1463 /* 1464 * Interface to hold a bunch of attributes. 1465 * used for creating new files. 1466 * attrsize is the total size of all attributes 1467 * to be added during object creation 1468 * 1469 * For updating/adding a single attribute dmu_tx_hold_sa() should be used. 1470 */ 1471 1472 /* 1473 * hold necessary attribute name for attribute registration. 1474 * should be a very rare case where this is needed. If it does 1475 * happen it would only happen on the first write to the file system. 1476 */ 1477 static void 1478 dmu_tx_sa_registration_hold(sa_os_t *sa, dmu_tx_t *tx) 1479 { 1480 int i; 1481 1482 if (!sa->sa_need_attr_registration) 1483 return; 1484 1485 for (i = 0; i != sa->sa_num_attrs; i++) { 1486 if (!sa->sa_attr_table[i].sa_registered) { 1487 if (sa->sa_reg_attr_obj) 1488 dmu_tx_hold_zap(tx, sa->sa_reg_attr_obj, 1489 B_TRUE, sa->sa_attr_table[i].sa_name); 1490 else 1491 dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, 1492 B_TRUE, sa->sa_attr_table[i].sa_name); 1493 } 1494 } 1495 } 1496 1497 1498 void 1499 dmu_tx_hold_spill(dmu_tx_t *tx, uint64_t object) 1500 { 1501 dnode_t *dn; 1502 dmu_tx_hold_t *txh; 1503 1504 txh = dmu_tx_hold_object_impl(tx, tx->tx_objset, object, 1505 THT_SPILL, 0, 0); 1506 1507 dn = txh->txh_dnode; 1508 1509 if (dn == NULL) 1510 return; 1511 1512 /* If blkptr doesn't exist then add space to towrite */ 1513 if (!(dn->dn_phys->dn_flags & DNODE_FLAG_SPILL_BLKPTR)) { 1514 txh->txh_space_towrite += SPA_MAXBLOCKSIZE; 1515 } else { 1516 blkptr_t *bp; 1517 1518 bp = &dn->dn_phys->dn_spill; 1519 if (dsl_dataset_block_freeable(dn->dn_objset->os_dsl_dataset, 1520 bp, bp->blk_birth)) 1521 txh->txh_space_tooverwrite += SPA_MAXBLOCKSIZE; 1522 else 1523 txh->txh_space_towrite += SPA_MAXBLOCKSIZE; 1524 if (!BP_IS_HOLE(bp)) 1525 txh->txh_space_tounref += SPA_MAXBLOCKSIZE; 1526 } 1527 } 1528 1529 void 1530 dmu_tx_hold_sa_create(dmu_tx_t *tx, int attrsize) 1531 { 1532 sa_os_t *sa = tx->tx_objset->os_sa; 1533 1534 dmu_tx_hold_bonus(tx, DMU_NEW_OBJECT); 1535 1536 if (tx->tx_objset->os_sa->sa_master_obj == 0) 1537 return; 1538 1539 if (tx->tx_objset->os_sa->sa_layout_attr_obj) 1540 dmu_tx_hold_zap(tx, sa->sa_layout_attr_obj, B_TRUE, NULL); 1541 else { 1542 dmu_tx_hold_zap(tx, sa->sa_master_obj, B_TRUE, SA_LAYOUTS); 1543 dmu_tx_hold_zap(tx, sa->sa_master_obj, B_TRUE, SA_REGISTRY); 1544 dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, B_TRUE, NULL); 1545 dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, B_TRUE, NULL); 1546 } 1547 1548 dmu_tx_sa_registration_hold(sa, tx); 1549 1550 if (attrsize <= DN_MAX_BONUSLEN && !sa->sa_force_spill) 1551 return; 1552 1553 (void) dmu_tx_hold_object_impl(tx, tx->tx_objset, DMU_NEW_OBJECT, 1554 THT_SPILL, 0, 0); 1555 } 1556 1557 /* 1558 * Hold SA attribute 1559 * 1560 * dmu_tx_hold_sa(dmu_tx_t *tx, sa_handle_t *, attribute, add, size) 1561 * 1562 * variable_size is the total size of all variable sized attributes 1563 * passed to this function. It is not the total size of all 1564 * variable size attributes that *may* exist on this object. 1565 */ 1566 void 1567 dmu_tx_hold_sa(dmu_tx_t *tx, sa_handle_t *hdl, boolean_t may_grow) 1568 { 1569 uint64_t object; 1570 sa_os_t *sa = tx->tx_objset->os_sa; 1571 1572 ASSERT(hdl != NULL); 1573 1574 object = sa_handle_object(hdl); 1575 1576 dmu_tx_hold_bonus(tx, object); 1577 1578 if (tx->tx_objset->os_sa->sa_master_obj == 0) 1579 return; 1580 1581 if (tx->tx_objset->os_sa->sa_reg_attr_obj == 0 || 1582 tx->tx_objset->os_sa->sa_layout_attr_obj == 0) { 1583 dmu_tx_hold_zap(tx, sa->sa_master_obj, B_TRUE, SA_LAYOUTS); 1584 dmu_tx_hold_zap(tx, sa->sa_master_obj, B_TRUE, SA_REGISTRY); 1585 dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, B_TRUE, NULL); 1586 dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, B_TRUE, NULL); 1587 } 1588 1589 dmu_tx_sa_registration_hold(sa, tx); 1590 1591 if (may_grow && tx->tx_objset->os_sa->sa_layout_attr_obj) 1592 dmu_tx_hold_zap(tx, sa->sa_layout_attr_obj, B_TRUE, NULL); 1593 1594 if (sa->sa_force_spill || may_grow || hdl->sa_spill) { 1595 ASSERT(tx->tx_txg == 0); 1596 dmu_tx_hold_spill(tx, object); 1597 } else { 1598 dmu_buf_impl_t *db = (dmu_buf_impl_t *)hdl->sa_bonus; 1599 dnode_t *dn; 1600 1601 DB_DNODE_ENTER(db); 1602 dn = DB_DNODE(db); 1603 if (dn->dn_have_spill) { 1604 ASSERT(tx->tx_txg == 0); 1605 dmu_tx_hold_spill(tx, object); 1606 } 1607 DB_DNODE_EXIT(db); 1608 } 1609 } 1610