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, 2015 by Delphix. All rights reserved. 25 * Copyright (c) 2014 Integros [integros.com] 26 */ 27 28 #include <sys/dmu.h> 29 #include <sys/dmu_impl.h> 30 #include <sys/dbuf.h> 31 #include <sys/dmu_tx.h> 32 #include <sys/dmu_objset.h> 33 #include <sys/dsl_dataset.h> /* for dsl_dataset_block_freeable() */ 34 #include <sys/dsl_dir.h> /* for dsl_dir_tempreserve_*() */ 35 #include <sys/dsl_pool.h> 36 #include <sys/zap_impl.h> /* for fzap_default_block_shift */ 37 #include <sys/spa.h> 38 #include <sys/sa.h> 39 #include <sys/sa_impl.h> 40 #include <sys/zfs_context.h> 41 #include <sys/varargs.h> 42 43 typedef void (*dmu_tx_hold_func_t)(dmu_tx_t *tx, struct dnode *dn, 44 uint64_t arg1, uint64_t arg2); 45 46 47 dmu_tx_t * 48 dmu_tx_create_dd(dsl_dir_t *dd) 49 { 50 dmu_tx_t *tx = kmem_zalloc(sizeof (dmu_tx_t), KM_SLEEP); 51 tx->tx_dir = dd; 52 if (dd != NULL) 53 tx->tx_pool = dd->dd_pool; 54 list_create(&tx->tx_holds, sizeof (dmu_tx_hold_t), 55 offsetof(dmu_tx_hold_t, txh_node)); 56 list_create(&tx->tx_callbacks, sizeof (dmu_tx_callback_t), 57 offsetof(dmu_tx_callback_t, dcb_node)); 58 tx->tx_start = gethrtime(); 59 #ifdef ZFS_DEBUG 60 refcount_create(&tx->tx_space_written); 61 refcount_create(&tx->tx_space_freed); 62 #endif 63 return (tx); 64 } 65 66 dmu_tx_t * 67 dmu_tx_create(objset_t *os) 68 { 69 dmu_tx_t *tx = dmu_tx_create_dd(os->os_dsl_dataset->ds_dir); 70 tx->tx_objset = os; 71 tx->tx_lastsnap_txg = dsl_dataset_prev_snap_txg(os->os_dsl_dataset); 72 return (tx); 73 } 74 75 dmu_tx_t * 76 dmu_tx_create_assigned(struct dsl_pool *dp, uint64_t txg) 77 { 78 dmu_tx_t *tx = dmu_tx_create_dd(NULL); 79 80 ASSERT3U(txg, <=, dp->dp_tx.tx_open_txg); 81 tx->tx_pool = dp; 82 tx->tx_txg = txg; 83 tx->tx_anyobj = TRUE; 84 85 return (tx); 86 } 87 88 int 89 dmu_tx_is_syncing(dmu_tx_t *tx) 90 { 91 return (tx->tx_anyobj); 92 } 93 94 int 95 dmu_tx_private_ok(dmu_tx_t *tx) 96 { 97 return (tx->tx_anyobj); 98 } 99 100 static dmu_tx_hold_t * 101 dmu_tx_hold_object_impl(dmu_tx_t *tx, objset_t *os, uint64_t object, 102 enum dmu_tx_hold_type type, uint64_t arg1, uint64_t arg2) 103 { 104 dmu_tx_hold_t *txh; 105 dnode_t *dn = NULL; 106 int err; 107 108 if (object != DMU_NEW_OBJECT) { 109 err = dnode_hold(os, object, tx, &dn); 110 if (err) { 111 tx->tx_err = err; 112 return (NULL); 113 } 114 115 if (err == 0 && tx->tx_txg != 0) { 116 mutex_enter(&dn->dn_mtx); 117 /* 118 * dn->dn_assigned_txg == tx->tx_txg doesn't pose a 119 * problem, but there's no way for it to happen (for 120 * now, at least). 121 */ 122 ASSERT(dn->dn_assigned_txg == 0); 123 dn->dn_assigned_txg = tx->tx_txg; 124 (void) refcount_add(&dn->dn_tx_holds, tx); 125 mutex_exit(&dn->dn_mtx); 126 } 127 } 128 129 txh = kmem_zalloc(sizeof (dmu_tx_hold_t), KM_SLEEP); 130 txh->txh_tx = tx; 131 txh->txh_dnode = dn; 132 #ifdef ZFS_DEBUG 133 txh->txh_type = type; 134 txh->txh_arg1 = arg1; 135 txh->txh_arg2 = arg2; 136 #endif 137 list_insert_tail(&tx->tx_holds, txh); 138 139 return (txh); 140 } 141 142 void 143 dmu_tx_add_new_object(dmu_tx_t *tx, objset_t *os, uint64_t object) 144 { 145 /* 146 * If we're syncing, they can manipulate any object anyhow, and 147 * the hold on the dnode_t can cause problems. 148 */ 149 if (!dmu_tx_is_syncing(tx)) { 150 (void) dmu_tx_hold_object_impl(tx, os, 151 object, THT_NEWOBJECT, 0, 0); 152 } 153 } 154 155 static int 156 dmu_tx_check_ioerr(zio_t *zio, dnode_t *dn, int level, uint64_t blkid) 157 { 158 int err; 159 dmu_buf_impl_t *db; 160 161 rw_enter(&dn->dn_struct_rwlock, RW_READER); 162 db = dbuf_hold_level(dn, level, blkid, FTAG); 163 rw_exit(&dn->dn_struct_rwlock); 164 if (db == NULL) 165 return (SET_ERROR(EIO)); 166 err = dbuf_read(db, zio, DB_RF_CANFAIL | DB_RF_NOPREFETCH); 167 dbuf_rele(db, FTAG); 168 return (err); 169 } 170 171 static void 172 dmu_tx_count_twig(dmu_tx_hold_t *txh, dnode_t *dn, dmu_buf_impl_t *db, 173 int level, uint64_t blkid, boolean_t freeable, uint64_t *history) 174 { 175 objset_t *os = dn->dn_objset; 176 dsl_dataset_t *ds = os->os_dsl_dataset; 177 int epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT; 178 dmu_buf_impl_t *parent = NULL; 179 blkptr_t *bp = NULL; 180 uint64_t space; 181 182 if (level >= dn->dn_nlevels || history[level] == blkid) 183 return; 184 185 history[level] = blkid; 186 187 space = (level == 0) ? dn->dn_datablksz : (1ULL << dn->dn_indblkshift); 188 189 if (db == NULL || db == dn->dn_dbuf) { 190 ASSERT(level != 0); 191 db = NULL; 192 } else { 193 ASSERT(DB_DNODE(db) == dn); 194 ASSERT(db->db_level == level); 195 ASSERT(db->db.db_size == space); 196 ASSERT(db->db_blkid == blkid); 197 bp = db->db_blkptr; 198 parent = db->db_parent; 199 } 200 201 freeable = (bp && (freeable || 202 dsl_dataset_block_freeable(ds, bp, bp->blk_birth))); 203 204 if (freeable) 205 txh->txh_space_tooverwrite += space; 206 else 207 txh->txh_space_towrite += space; 208 if (bp) 209 txh->txh_space_tounref += bp_get_dsize(os->os_spa, bp); 210 211 dmu_tx_count_twig(txh, dn, parent, level + 1, 212 blkid >> epbs, freeable, history); 213 } 214 215 /* ARGSUSED */ 216 static void 217 dmu_tx_count_write(dmu_tx_hold_t *txh, uint64_t off, uint64_t len) 218 { 219 dnode_t *dn = txh->txh_dnode; 220 uint64_t start, end, i; 221 int min_bs, max_bs, min_ibs, max_ibs, epbs, bits; 222 int err = 0; 223 224 if (len == 0) 225 return; 226 227 min_bs = SPA_MINBLOCKSHIFT; 228 max_bs = highbit64(txh->txh_tx->tx_objset->os_recordsize) - 1; 229 min_ibs = DN_MIN_INDBLKSHIFT; 230 max_ibs = DN_MAX_INDBLKSHIFT; 231 232 if (dn) { 233 uint64_t history[DN_MAX_LEVELS]; 234 int nlvls = dn->dn_nlevels; 235 int delta; 236 237 /* 238 * For i/o error checking, read the first and last level-0 239 * blocks (if they are not aligned), and all the level-1 blocks. 240 */ 241 if (dn->dn_maxblkid == 0) { 242 delta = dn->dn_datablksz; 243 start = (off < dn->dn_datablksz) ? 0 : 1; 244 end = (off+len <= dn->dn_datablksz) ? 0 : 1; 245 if (start == 0 && (off > 0 || len < dn->dn_datablksz)) { 246 err = dmu_tx_check_ioerr(NULL, dn, 0, 0); 247 if (err) 248 goto out; 249 delta -= off; 250 } 251 } else { 252 zio_t *zio = zio_root(dn->dn_objset->os_spa, 253 NULL, NULL, ZIO_FLAG_CANFAIL); 254 255 /* first level-0 block */ 256 start = off >> dn->dn_datablkshift; 257 if (P2PHASE(off, dn->dn_datablksz) || 258 len < dn->dn_datablksz) { 259 err = dmu_tx_check_ioerr(zio, dn, 0, start); 260 if (err) 261 goto out; 262 } 263 264 /* last level-0 block */ 265 end = (off+len-1) >> dn->dn_datablkshift; 266 if (end != start && end <= dn->dn_maxblkid && 267 P2PHASE(off+len, dn->dn_datablksz)) { 268 err = dmu_tx_check_ioerr(zio, dn, 0, end); 269 if (err) 270 goto out; 271 } 272 273 /* level-1 blocks */ 274 if (nlvls > 1) { 275 int shft = dn->dn_indblkshift - SPA_BLKPTRSHIFT; 276 for (i = (start>>shft)+1; i < end>>shft; i++) { 277 err = dmu_tx_check_ioerr(zio, dn, 1, i); 278 if (err) 279 goto out; 280 } 281 } 282 283 err = zio_wait(zio); 284 if (err) 285 goto out; 286 delta = P2NPHASE(off, dn->dn_datablksz); 287 } 288 289 min_ibs = max_ibs = dn->dn_indblkshift; 290 if (dn->dn_maxblkid > 0) { 291 /* 292 * The blocksize can't change, 293 * so we can make a more precise estimate. 294 */ 295 ASSERT(dn->dn_datablkshift != 0); 296 min_bs = max_bs = dn->dn_datablkshift; 297 } else { 298 /* 299 * The blocksize can increase up to the recordsize, 300 * or if it is already more than the recordsize, 301 * up to the next power of 2. 302 */ 303 min_bs = highbit64(dn->dn_datablksz - 1); 304 max_bs = MAX(max_bs, highbit64(dn->dn_datablksz - 1)); 305 } 306 307 /* 308 * If this write is not off the end of the file 309 * we need to account for overwrites/unref. 310 */ 311 if (start <= dn->dn_maxblkid) { 312 for (int l = 0; l < DN_MAX_LEVELS; l++) 313 history[l] = -1ULL; 314 } 315 while (start <= dn->dn_maxblkid) { 316 dmu_buf_impl_t *db; 317 318 rw_enter(&dn->dn_struct_rwlock, RW_READER); 319 err = dbuf_hold_impl(dn, 0, start, 320 FALSE, FALSE, FTAG, &db); 321 rw_exit(&dn->dn_struct_rwlock); 322 323 if (err) { 324 txh->txh_tx->tx_err = err; 325 return; 326 } 327 328 dmu_tx_count_twig(txh, dn, db, 0, start, B_FALSE, 329 history); 330 dbuf_rele(db, FTAG); 331 if (++start > end) { 332 /* 333 * Account for new indirects appearing 334 * before this IO gets assigned into a txg. 335 */ 336 bits = 64 - min_bs; 337 epbs = min_ibs - SPA_BLKPTRSHIFT; 338 for (bits -= epbs * (nlvls - 1); 339 bits >= 0; bits -= epbs) 340 txh->txh_fudge += 1ULL << max_ibs; 341 goto out; 342 } 343 off += delta; 344 if (len >= delta) 345 len -= delta; 346 delta = dn->dn_datablksz; 347 } 348 } 349 350 /* 351 * 'end' is the last thing we will access, not one past. 352 * This way we won't overflow when accessing the last byte. 353 */ 354 start = P2ALIGN(off, 1ULL << max_bs); 355 end = P2ROUNDUP(off + len, 1ULL << max_bs) - 1; 356 txh->txh_space_towrite += end - start + 1; 357 358 start >>= min_bs; 359 end >>= min_bs; 360 361 epbs = min_ibs - SPA_BLKPTRSHIFT; 362 363 /* 364 * The object contains at most 2^(64 - min_bs) blocks, 365 * and each indirect level maps 2^epbs. 366 */ 367 for (bits = 64 - min_bs; bits >= 0; bits -= epbs) { 368 start >>= epbs; 369 end >>= epbs; 370 ASSERT3U(end, >=, start); 371 txh->txh_space_towrite += (end - start + 1) << max_ibs; 372 if (start != 0) { 373 /* 374 * We also need a new blkid=0 indirect block 375 * to reference any existing file data. 376 */ 377 txh->txh_space_towrite += 1ULL << max_ibs; 378 } 379 } 380 381 out: 382 if (txh->txh_space_towrite + txh->txh_space_tooverwrite > 383 2 * DMU_MAX_ACCESS) 384 err = SET_ERROR(EFBIG); 385 386 if (err) 387 txh->txh_tx->tx_err = err; 388 } 389 390 static void 391 dmu_tx_count_dnode(dmu_tx_hold_t *txh) 392 { 393 dnode_t *dn = txh->txh_dnode; 394 dnode_t *mdn = DMU_META_DNODE(txh->txh_tx->tx_objset); 395 uint64_t space = mdn->dn_datablksz + 396 ((mdn->dn_nlevels-1) << mdn->dn_indblkshift); 397 398 if (dn && dn->dn_dbuf->db_blkptr && 399 dsl_dataset_block_freeable(dn->dn_objset->os_dsl_dataset, 400 dn->dn_dbuf->db_blkptr, dn->dn_dbuf->db_blkptr->blk_birth)) { 401 txh->txh_space_tooverwrite += space; 402 txh->txh_space_tounref += space; 403 } else { 404 txh->txh_space_towrite += space; 405 if (dn && dn->dn_dbuf->db_blkptr) 406 txh->txh_space_tounref += space; 407 } 408 } 409 410 void 411 dmu_tx_hold_write(dmu_tx_t *tx, uint64_t object, uint64_t off, int len) 412 { 413 dmu_tx_hold_t *txh; 414 415 ASSERT(tx->tx_txg == 0); 416 ASSERT(len < DMU_MAX_ACCESS); 417 ASSERT(len == 0 || UINT64_MAX - off >= len - 1); 418 419 txh = dmu_tx_hold_object_impl(tx, tx->tx_objset, 420 object, THT_WRITE, off, len); 421 if (txh == NULL) 422 return; 423 424 dmu_tx_count_write(txh, off, len); 425 dmu_tx_count_dnode(txh); 426 } 427 428 static void 429 dmu_tx_count_free(dmu_tx_hold_t *txh, uint64_t off, uint64_t len) 430 { 431 uint64_t blkid, nblks, lastblk; 432 uint64_t space = 0, unref = 0, skipped = 0; 433 dnode_t *dn = txh->txh_dnode; 434 dsl_dataset_t *ds = dn->dn_objset->os_dsl_dataset; 435 spa_t *spa = txh->txh_tx->tx_pool->dp_spa; 436 int epbs; 437 uint64_t l0span = 0, nl1blks = 0; 438 439 if (dn->dn_nlevels == 0) 440 return; 441 442 /* 443 * The struct_rwlock protects us against dn_nlevels 444 * changing, in case (against all odds) we manage to dirty & 445 * sync out the changes after we check for being dirty. 446 * Also, dbuf_hold_impl() wants us to have the struct_rwlock. 447 */ 448 rw_enter(&dn->dn_struct_rwlock, RW_READER); 449 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT; 450 if (dn->dn_maxblkid == 0) { 451 if (off == 0 && len >= dn->dn_datablksz) { 452 blkid = 0; 453 nblks = 1; 454 } else { 455 rw_exit(&dn->dn_struct_rwlock); 456 return; 457 } 458 } else { 459 blkid = off >> dn->dn_datablkshift; 460 nblks = (len + dn->dn_datablksz - 1) >> dn->dn_datablkshift; 461 462 if (blkid > dn->dn_maxblkid) { 463 rw_exit(&dn->dn_struct_rwlock); 464 return; 465 } 466 if (blkid + nblks > dn->dn_maxblkid) 467 nblks = dn->dn_maxblkid - blkid + 1; 468 469 } 470 l0span = nblks; /* save for later use to calc level > 1 overhead */ 471 if (dn->dn_nlevels == 1) { 472 int i; 473 for (i = 0; i < nblks; i++) { 474 blkptr_t *bp = dn->dn_phys->dn_blkptr; 475 ASSERT3U(blkid + i, <, dn->dn_nblkptr); 476 bp += blkid + i; 477 if (dsl_dataset_block_freeable(ds, bp, bp->blk_birth)) { 478 dprintf_bp(bp, "can free old%s", ""); 479 space += bp_get_dsize(spa, bp); 480 } 481 unref += BP_GET_ASIZE(bp); 482 } 483 nl1blks = 1; 484 nblks = 0; 485 } 486 487 lastblk = blkid + nblks - 1; 488 while (nblks) { 489 dmu_buf_impl_t *dbuf; 490 uint64_t ibyte, new_blkid; 491 int epb = 1 << epbs; 492 int err, i, blkoff, tochk; 493 blkptr_t *bp; 494 495 ibyte = blkid << dn->dn_datablkshift; 496 err = dnode_next_offset(dn, 497 DNODE_FIND_HAVELOCK, &ibyte, 2, 1, 0); 498 new_blkid = ibyte >> dn->dn_datablkshift; 499 if (err == ESRCH) { 500 skipped += (lastblk >> epbs) - (blkid >> epbs) + 1; 501 break; 502 } 503 if (err) { 504 txh->txh_tx->tx_err = err; 505 break; 506 } 507 if (new_blkid > lastblk) { 508 skipped += (lastblk >> epbs) - (blkid >> epbs) + 1; 509 break; 510 } 511 512 if (new_blkid > blkid) { 513 ASSERT((new_blkid >> epbs) > (blkid >> epbs)); 514 skipped += (new_blkid >> epbs) - (blkid >> epbs) - 1; 515 nblks -= new_blkid - blkid; 516 blkid = new_blkid; 517 } 518 blkoff = P2PHASE(blkid, epb); 519 tochk = MIN(epb - blkoff, nblks); 520 521 err = dbuf_hold_impl(dn, 1, blkid >> epbs, 522 FALSE, FALSE, FTAG, &dbuf); 523 if (err) { 524 txh->txh_tx->tx_err = err; 525 break; 526 } 527 528 txh->txh_memory_tohold += dbuf->db.db_size; 529 530 /* 531 * We don't check memory_tohold against DMU_MAX_ACCESS because 532 * memory_tohold is an over-estimation (especially the >L1 533 * indirect blocks), so it could fail. Callers should have 534 * already verified that they will not be holding too much 535 * memory. 536 */ 537 538 err = dbuf_read(dbuf, NULL, DB_RF_HAVESTRUCT | DB_RF_CANFAIL); 539 if (err != 0) { 540 txh->txh_tx->tx_err = err; 541 dbuf_rele(dbuf, FTAG); 542 break; 543 } 544 545 bp = dbuf->db.db_data; 546 bp += blkoff; 547 548 for (i = 0; i < tochk; i++) { 549 if (dsl_dataset_block_freeable(ds, &bp[i], 550 bp[i].blk_birth)) { 551 dprintf_bp(&bp[i], "can free old%s", ""); 552 space += bp_get_dsize(spa, &bp[i]); 553 } 554 unref += BP_GET_ASIZE(bp); 555 } 556 dbuf_rele(dbuf, FTAG); 557 558 ++nl1blks; 559 blkid += tochk; 560 nblks -= tochk; 561 } 562 rw_exit(&dn->dn_struct_rwlock); 563 564 /* 565 * Add in memory requirements of higher-level indirects. 566 * This assumes a worst-possible scenario for dn_nlevels and a 567 * worst-possible distribution of l1-blocks over the region to free. 568 */ 569 { 570 uint64_t blkcnt = 1 + ((l0span >> epbs) >> epbs); 571 int level = 2; 572 /* 573 * Here we don't use DN_MAX_LEVEL, but calculate it with the 574 * given datablkshift and indblkshift. This makes the 575 * difference between 19 and 8 on large files. 576 */ 577 int maxlevel = 2 + (DN_MAX_OFFSET_SHIFT - dn->dn_datablkshift) / 578 (dn->dn_indblkshift - SPA_BLKPTRSHIFT); 579 580 while (level++ < maxlevel) { 581 txh->txh_memory_tohold += MAX(MIN(blkcnt, nl1blks), 1) 582 << dn->dn_indblkshift; 583 blkcnt = 1 + (blkcnt >> epbs); 584 } 585 } 586 587 /* account for new level 1 indirect blocks that might show up */ 588 if (skipped > 0) { 589 txh->txh_fudge += skipped << dn->dn_indblkshift; 590 skipped = MIN(skipped, DMU_MAX_DELETEBLKCNT >> epbs); 591 txh->txh_memory_tohold += skipped << dn->dn_indblkshift; 592 } 593 txh->txh_space_tofree += space; 594 txh->txh_space_tounref += unref; 595 } 596 597 /* 598 * This function marks the transaction as being a "net free". The end 599 * result is that refquotas will be disabled for this transaction, and 600 * this transaction will be able to use half of the pool space overhead 601 * (see dsl_pool_adjustedsize()). Therefore this function should only 602 * be called for transactions that we expect will not cause a net increase 603 * in the amount of space used (but it's OK if that is occasionally not true). 604 */ 605 void 606 dmu_tx_mark_netfree(dmu_tx_t *tx) 607 { 608 dmu_tx_hold_t *txh; 609 610 txh = dmu_tx_hold_object_impl(tx, tx->tx_objset, 611 DMU_NEW_OBJECT, THT_FREE, 0, 0); 612 613 /* 614 * Pretend that this operation will free 1GB of space. This 615 * should be large enough to cancel out the largest write. 616 * We don't want to use something like UINT64_MAX, because that would 617 * cause overflows when doing math with these values (e.g. in 618 * dmu_tx_try_assign()). 619 */ 620 txh->txh_space_tofree = txh->txh_space_tounref = 1024 * 1024 * 1024; 621 } 622 623 void 624 dmu_tx_hold_free(dmu_tx_t *tx, uint64_t object, uint64_t off, uint64_t len) 625 { 626 dmu_tx_hold_t *txh; 627 dnode_t *dn; 628 int err; 629 zio_t *zio; 630 631 ASSERT(tx->tx_txg == 0); 632 633 txh = dmu_tx_hold_object_impl(tx, tx->tx_objset, 634 object, THT_FREE, off, len); 635 if (txh == NULL) 636 return; 637 dn = txh->txh_dnode; 638 dmu_tx_count_dnode(txh); 639 640 if (off >= (dn->dn_maxblkid+1) * dn->dn_datablksz) 641 return; 642 if (len == DMU_OBJECT_END) 643 len = (dn->dn_maxblkid+1) * dn->dn_datablksz - off; 644 645 /* 646 * For i/o error checking, we read the first and last level-0 647 * blocks if they are not aligned, and all the level-1 blocks. 648 * 649 * Note: dbuf_free_range() assumes that we have not instantiated 650 * any level-0 dbufs that will be completely freed. Therefore we must 651 * exercise care to not read or count the first and last blocks 652 * if they are blocksize-aligned. 653 */ 654 if (dn->dn_datablkshift == 0) { 655 if (off != 0 || len < dn->dn_datablksz) 656 dmu_tx_count_write(txh, 0, dn->dn_datablksz); 657 } else { 658 /* first block will be modified if it is not aligned */ 659 if (!IS_P2ALIGNED(off, 1 << dn->dn_datablkshift)) 660 dmu_tx_count_write(txh, off, 1); 661 /* last block will be modified if it is not aligned */ 662 if (!IS_P2ALIGNED(off + len, 1 << dn->dn_datablkshift)) 663 dmu_tx_count_write(txh, off+len, 1); 664 } 665 666 /* 667 * Check level-1 blocks. 668 */ 669 if (dn->dn_nlevels > 1) { 670 int shift = dn->dn_datablkshift + dn->dn_indblkshift - 671 SPA_BLKPTRSHIFT; 672 uint64_t start = off >> shift; 673 uint64_t end = (off + len) >> shift; 674 675 ASSERT(dn->dn_indblkshift != 0); 676 677 /* 678 * dnode_reallocate() can result in an object with indirect 679 * blocks having an odd data block size. In this case, 680 * just check the single block. 681 */ 682 if (dn->dn_datablkshift == 0) 683 start = end = 0; 684 685 zio = zio_root(tx->tx_pool->dp_spa, 686 NULL, NULL, ZIO_FLAG_CANFAIL); 687 for (uint64_t i = start; i <= end; i++) { 688 uint64_t ibyte = i << shift; 689 err = dnode_next_offset(dn, 0, &ibyte, 2, 1, 0); 690 i = ibyte >> shift; 691 if (err == ESRCH || i > end) 692 break; 693 if (err) { 694 tx->tx_err = err; 695 return; 696 } 697 698 err = dmu_tx_check_ioerr(zio, dn, 1, i); 699 if (err) { 700 tx->tx_err = err; 701 return; 702 } 703 } 704 err = zio_wait(zio); 705 if (err) { 706 tx->tx_err = err; 707 return; 708 } 709 } 710 711 dmu_tx_count_free(txh, off, len); 712 } 713 714 void 715 dmu_tx_hold_zap(dmu_tx_t *tx, uint64_t object, int add, const char *name) 716 { 717 dmu_tx_hold_t *txh; 718 dnode_t *dn; 719 dsl_dataset_phys_t *ds_phys; 720 uint64_t nblocks; 721 int epbs, err; 722 723 ASSERT(tx->tx_txg == 0); 724 725 txh = dmu_tx_hold_object_impl(tx, tx->tx_objset, 726 object, THT_ZAP, add, (uintptr_t)name); 727 if (txh == NULL) 728 return; 729 dn = txh->txh_dnode; 730 731 dmu_tx_count_dnode(txh); 732 733 if (dn == NULL) { 734 /* 735 * We will be able to fit a new object's entries into one leaf 736 * block. So there will be at most 2 blocks total, 737 * including the header block. 738 */ 739 dmu_tx_count_write(txh, 0, 2 << fzap_default_block_shift); 740 return; 741 } 742 743 ASSERT3P(DMU_OT_BYTESWAP(dn->dn_type), ==, DMU_BSWAP_ZAP); 744 745 if (dn->dn_maxblkid == 0 && !add) { 746 blkptr_t *bp; 747 748 /* 749 * If there is only one block (i.e. this is a micro-zap) 750 * and we are not adding anything, the accounting is simple. 751 */ 752 err = dmu_tx_check_ioerr(NULL, dn, 0, 0); 753 if (err) { 754 tx->tx_err = err; 755 return; 756 } 757 758 /* 759 * Use max block size here, since we don't know how much 760 * the size will change between now and the dbuf dirty call. 761 */ 762 bp = &dn->dn_phys->dn_blkptr[0]; 763 if (dsl_dataset_block_freeable(dn->dn_objset->os_dsl_dataset, 764 bp, bp->blk_birth)) 765 txh->txh_space_tooverwrite += MZAP_MAX_BLKSZ; 766 else 767 txh->txh_space_towrite += MZAP_MAX_BLKSZ; 768 if (!BP_IS_HOLE(bp)) 769 txh->txh_space_tounref += MZAP_MAX_BLKSZ; 770 return; 771 } 772 773 if (dn->dn_maxblkid > 0 && name) { 774 /* 775 * access the name in this fat-zap so that we'll check 776 * for i/o errors to the leaf blocks, etc. 777 */ 778 err = zap_lookup(dn->dn_objset, dn->dn_object, name, 779 8, 0, NULL); 780 if (err == EIO) { 781 tx->tx_err = err; 782 return; 783 } 784 } 785 786 err = zap_count_write(dn->dn_objset, dn->dn_object, name, add, 787 &txh->txh_space_towrite, &txh->txh_space_tooverwrite); 788 789 /* 790 * If the modified blocks are scattered to the four winds, 791 * we'll have to modify an indirect twig for each. 792 */ 793 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT; 794 ds_phys = dsl_dataset_phys(dn->dn_objset->os_dsl_dataset); 795 for (nblocks = dn->dn_maxblkid >> epbs; nblocks != 0; nblocks >>= epbs) 796 if (ds_phys->ds_prev_snap_obj) 797 txh->txh_space_towrite += 3 << dn->dn_indblkshift; 798 else 799 txh->txh_space_tooverwrite += 3 << dn->dn_indblkshift; 800 } 801 802 void 803 dmu_tx_hold_bonus(dmu_tx_t *tx, uint64_t object) 804 { 805 dmu_tx_hold_t *txh; 806 807 ASSERT(tx->tx_txg == 0); 808 809 txh = dmu_tx_hold_object_impl(tx, tx->tx_objset, 810 object, THT_BONUS, 0, 0); 811 if (txh) 812 dmu_tx_count_dnode(txh); 813 } 814 815 void 816 dmu_tx_hold_space(dmu_tx_t *tx, uint64_t space) 817 { 818 dmu_tx_hold_t *txh; 819 ASSERT(tx->tx_txg == 0); 820 821 txh = dmu_tx_hold_object_impl(tx, tx->tx_objset, 822 DMU_NEW_OBJECT, THT_SPACE, space, 0); 823 824 txh->txh_space_towrite += space; 825 } 826 827 int 828 dmu_tx_holds(dmu_tx_t *tx, uint64_t object) 829 { 830 dmu_tx_hold_t *txh; 831 int holds = 0; 832 833 /* 834 * By asserting that the tx is assigned, we're counting the 835 * number of dn_tx_holds, which is the same as the number of 836 * dn_holds. Otherwise, we'd be counting dn_holds, but 837 * dn_tx_holds could be 0. 838 */ 839 ASSERT(tx->tx_txg != 0); 840 841 /* if (tx->tx_anyobj == TRUE) */ 842 /* return (0); */ 843 844 for (txh = list_head(&tx->tx_holds); txh; 845 txh = list_next(&tx->tx_holds, txh)) { 846 if (txh->txh_dnode && txh->txh_dnode->dn_object == object) 847 holds++; 848 } 849 850 return (holds); 851 } 852 853 #ifdef ZFS_DEBUG 854 void 855 dmu_tx_dirty_buf(dmu_tx_t *tx, dmu_buf_impl_t *db) 856 { 857 dmu_tx_hold_t *txh; 858 int match_object = FALSE, match_offset = FALSE; 859 dnode_t *dn; 860 861 DB_DNODE_ENTER(db); 862 dn = DB_DNODE(db); 863 ASSERT(tx->tx_txg != 0); 864 ASSERT(tx->tx_objset == NULL || dn->dn_objset == tx->tx_objset); 865 ASSERT3U(dn->dn_object, ==, db->db.db_object); 866 867 if (tx->tx_anyobj) { 868 DB_DNODE_EXIT(db); 869 return; 870 } 871 872 /* XXX No checking on the meta dnode for now */ 873 if (db->db.db_object == DMU_META_DNODE_OBJECT) { 874 DB_DNODE_EXIT(db); 875 return; 876 } 877 878 for (txh = list_head(&tx->tx_holds); txh; 879 txh = list_next(&tx->tx_holds, txh)) { 880 ASSERT(dn == NULL || dn->dn_assigned_txg == tx->tx_txg); 881 if (txh->txh_dnode == dn && txh->txh_type != THT_NEWOBJECT) 882 match_object = TRUE; 883 if (txh->txh_dnode == NULL || txh->txh_dnode == dn) { 884 int datablkshift = dn->dn_datablkshift ? 885 dn->dn_datablkshift : SPA_MAXBLOCKSHIFT; 886 int epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT; 887 int shift = datablkshift + epbs * db->db_level; 888 uint64_t beginblk = shift >= 64 ? 0 : 889 (txh->txh_arg1 >> shift); 890 uint64_t endblk = shift >= 64 ? 0 : 891 ((txh->txh_arg1 + txh->txh_arg2 - 1) >> shift); 892 uint64_t blkid = db->db_blkid; 893 894 /* XXX txh_arg2 better not be zero... */ 895 896 dprintf("found txh type %x beginblk=%llx endblk=%llx\n", 897 txh->txh_type, beginblk, endblk); 898 899 switch (txh->txh_type) { 900 case THT_WRITE: 901 if (blkid >= beginblk && blkid <= endblk) 902 match_offset = TRUE; 903 /* 904 * We will let this hold work for the bonus 905 * or spill buffer so that we don't need to 906 * hold it when creating a new object. 907 */ 908 if (blkid == DMU_BONUS_BLKID || 909 blkid == DMU_SPILL_BLKID) 910 match_offset = TRUE; 911 /* 912 * They might have to increase nlevels, 913 * thus dirtying the new TLIBs. Or the 914 * might have to change the block size, 915 * thus dirying the new lvl=0 blk=0. 916 */ 917 if (blkid == 0) 918 match_offset = TRUE; 919 break; 920 case THT_FREE: 921 /* 922 * We will dirty all the level 1 blocks in 923 * the free range and perhaps the first and 924 * last level 0 block. 925 */ 926 if (blkid >= beginblk && (blkid <= endblk || 927 txh->txh_arg2 == DMU_OBJECT_END)) 928 match_offset = TRUE; 929 break; 930 case THT_SPILL: 931 if (blkid == DMU_SPILL_BLKID) 932 match_offset = TRUE; 933 break; 934 case THT_BONUS: 935 if (blkid == DMU_BONUS_BLKID) 936 match_offset = TRUE; 937 break; 938 case THT_ZAP: 939 match_offset = TRUE; 940 break; 941 case THT_NEWOBJECT: 942 match_object = TRUE; 943 break; 944 default: 945 ASSERT(!"bad txh_type"); 946 } 947 } 948 if (match_object && match_offset) { 949 DB_DNODE_EXIT(db); 950 return; 951 } 952 } 953 DB_DNODE_EXIT(db); 954 panic("dirtying dbuf obj=%llx lvl=%u blkid=%llx but not tx_held\n", 955 (u_longlong_t)db->db.db_object, db->db_level, 956 (u_longlong_t)db->db_blkid); 957 } 958 #endif 959 960 /* 961 * If we can't do 10 iops, something is wrong. Let us go ahead 962 * and hit zfs_dirty_data_max. 963 */ 964 hrtime_t zfs_delay_max_ns = MSEC2NSEC(100); 965 int zfs_delay_resolution_ns = 100 * 1000; /* 100 microseconds */ 966 967 /* 968 * We delay transactions when we've determined that the backend storage 969 * isn't able to accommodate the rate of incoming writes. 970 * 971 * If there is already a transaction waiting, we delay relative to when 972 * that transaction finishes waiting. This way the calculated min_time 973 * is independent of the number of threads concurrently executing 974 * transactions. 975 * 976 * If we are the only waiter, wait relative to when the transaction 977 * started, rather than the current time. This credits the transaction for 978 * "time already served", e.g. reading indirect blocks. 979 * 980 * The minimum time for a transaction to take is calculated as: 981 * min_time = scale * (dirty - min) / (max - dirty) 982 * min_time is then capped at zfs_delay_max_ns. 983 * 984 * The delay has two degrees of freedom that can be adjusted via tunables. 985 * The percentage of dirty data at which we start to delay is defined by 986 * zfs_delay_min_dirty_percent. This should typically be at or above 987 * zfs_vdev_async_write_active_max_dirty_percent so that we only start to 988 * delay after writing at full speed has failed to keep up with the incoming 989 * write rate. The scale of the curve is defined by zfs_delay_scale. Roughly 990 * speaking, this variable determines the amount of delay at the midpoint of 991 * the curve. 992 * 993 * delay 994 * 10ms +-------------------------------------------------------------*+ 995 * | *| 996 * 9ms + *+ 997 * | *| 998 * 8ms + *+ 999 * | * | 1000 * 7ms + * + 1001 * | * | 1002 * 6ms + * + 1003 * | * | 1004 * 5ms + * + 1005 * | * | 1006 * 4ms + * + 1007 * | * | 1008 * 3ms + * + 1009 * | * | 1010 * 2ms + (midpoint) * + 1011 * | | ** | 1012 * 1ms + v *** + 1013 * | zfs_delay_scale ----------> ******** | 1014 * 0 +-------------------------------------*********----------------+ 1015 * 0% <- zfs_dirty_data_max -> 100% 1016 * 1017 * Note that since the delay is added to the outstanding time remaining on the 1018 * most recent transaction, the delay is effectively the inverse of IOPS. 1019 * Here the midpoint of 500us translates to 2000 IOPS. The shape of the curve 1020 * was chosen such that small changes in the amount of accumulated dirty data 1021 * in the first 3/4 of the curve yield relatively small differences in the 1022 * amount of delay. 1023 * 1024 * The effects can be easier to understand when the amount of delay is 1025 * represented on a log scale: 1026 * 1027 * delay 1028 * 100ms +-------------------------------------------------------------++ 1029 * + + 1030 * | | 1031 * + *+ 1032 * 10ms + *+ 1033 * + ** + 1034 * | (midpoint) ** | 1035 * + | ** + 1036 * 1ms + v **** + 1037 * + zfs_delay_scale ----------> ***** + 1038 * | **** | 1039 * + **** + 1040 * 100us + ** + 1041 * + * + 1042 * | * | 1043 * + * + 1044 * 10us + * + 1045 * + + 1046 * | | 1047 * + + 1048 * +--------------------------------------------------------------+ 1049 * 0% <- zfs_dirty_data_max -> 100% 1050 * 1051 * Note here that only as the amount of dirty data approaches its limit does 1052 * the delay start to increase rapidly. The goal of a properly tuned system 1053 * should be to keep the amount of dirty data out of that range by first 1054 * ensuring that the appropriate limits are set for the I/O scheduler to reach 1055 * optimal throughput on the backend storage, and then by changing the value 1056 * of zfs_delay_scale to increase the steepness of the curve. 1057 */ 1058 static void 1059 dmu_tx_delay(dmu_tx_t *tx, uint64_t dirty) 1060 { 1061 dsl_pool_t *dp = tx->tx_pool; 1062 uint64_t delay_min_bytes = 1063 zfs_dirty_data_max * zfs_delay_min_dirty_percent / 100; 1064 hrtime_t wakeup, min_tx_time, now; 1065 1066 if (dirty <= delay_min_bytes) 1067 return; 1068 1069 /* 1070 * The caller has already waited until we are under the max. 1071 * We make them pass us the amount of dirty data so we don't 1072 * have to handle the case of it being >= the max, which could 1073 * cause a divide-by-zero if it's == the max. 1074 */ 1075 ASSERT3U(dirty, <, zfs_dirty_data_max); 1076 1077 now = gethrtime(); 1078 min_tx_time = zfs_delay_scale * 1079 (dirty - delay_min_bytes) / (zfs_dirty_data_max - dirty); 1080 if (now > tx->tx_start + min_tx_time) 1081 return; 1082 1083 min_tx_time = MIN(min_tx_time, zfs_delay_max_ns); 1084 1085 DTRACE_PROBE3(delay__mintime, dmu_tx_t *, tx, uint64_t, dirty, 1086 uint64_t, min_tx_time); 1087 1088 mutex_enter(&dp->dp_lock); 1089 wakeup = MAX(tx->tx_start + min_tx_time, 1090 dp->dp_last_wakeup + min_tx_time); 1091 dp->dp_last_wakeup = wakeup; 1092 mutex_exit(&dp->dp_lock); 1093 1094 #ifdef _KERNEL 1095 mutex_enter(&curthread->t_delay_lock); 1096 while (cv_timedwait_hires(&curthread->t_delay_cv, 1097 &curthread->t_delay_lock, wakeup, zfs_delay_resolution_ns, 1098 CALLOUT_FLAG_ABSOLUTE | CALLOUT_FLAG_ROUNDUP) > 0) 1099 continue; 1100 mutex_exit(&curthread->t_delay_lock); 1101 #else 1102 hrtime_t delta = wakeup - gethrtime(); 1103 struct timespec ts; 1104 ts.tv_sec = delta / NANOSEC; 1105 ts.tv_nsec = delta % NANOSEC; 1106 (void) nanosleep(&ts, NULL); 1107 #endif 1108 } 1109 1110 static int 1111 dmu_tx_try_assign(dmu_tx_t *tx, txg_how_t txg_how) 1112 { 1113 dmu_tx_hold_t *txh; 1114 spa_t *spa = tx->tx_pool->dp_spa; 1115 uint64_t memory, asize, fsize, usize; 1116 uint64_t towrite, tofree, tooverwrite, tounref, tohold, fudge; 1117 1118 ASSERT0(tx->tx_txg); 1119 1120 if (tx->tx_err) 1121 return (tx->tx_err); 1122 1123 if (spa_suspended(spa)) { 1124 /* 1125 * If the user has indicated a blocking failure mode 1126 * then return ERESTART which will block in dmu_tx_wait(). 1127 * Otherwise, return EIO so that an error can get 1128 * propagated back to the VOP calls. 1129 * 1130 * Note that we always honor the txg_how flag regardless 1131 * of the failuremode setting. 1132 */ 1133 if (spa_get_failmode(spa) == ZIO_FAILURE_MODE_CONTINUE && 1134 txg_how != TXG_WAIT) 1135 return (SET_ERROR(EIO)); 1136 1137 return (SET_ERROR(ERESTART)); 1138 } 1139 1140 if (!tx->tx_waited && 1141 dsl_pool_need_dirty_delay(tx->tx_pool)) { 1142 tx->tx_wait_dirty = B_TRUE; 1143 return (SET_ERROR(ERESTART)); 1144 } 1145 1146 tx->tx_txg = txg_hold_open(tx->tx_pool, &tx->tx_txgh); 1147 tx->tx_needassign_txh = NULL; 1148 1149 /* 1150 * NB: No error returns are allowed after txg_hold_open, but 1151 * before processing the dnode holds, due to the 1152 * dmu_tx_unassign() logic. 1153 */ 1154 1155 towrite = tofree = tooverwrite = tounref = tohold = fudge = 0; 1156 for (txh = list_head(&tx->tx_holds); txh; 1157 txh = list_next(&tx->tx_holds, txh)) { 1158 dnode_t *dn = txh->txh_dnode; 1159 if (dn != NULL) { 1160 mutex_enter(&dn->dn_mtx); 1161 if (dn->dn_assigned_txg == tx->tx_txg - 1) { 1162 mutex_exit(&dn->dn_mtx); 1163 tx->tx_needassign_txh = txh; 1164 return (SET_ERROR(ERESTART)); 1165 } 1166 if (dn->dn_assigned_txg == 0) 1167 dn->dn_assigned_txg = tx->tx_txg; 1168 ASSERT3U(dn->dn_assigned_txg, ==, tx->tx_txg); 1169 (void) refcount_add(&dn->dn_tx_holds, tx); 1170 mutex_exit(&dn->dn_mtx); 1171 } 1172 towrite += txh->txh_space_towrite; 1173 tofree += txh->txh_space_tofree; 1174 tooverwrite += txh->txh_space_tooverwrite; 1175 tounref += txh->txh_space_tounref; 1176 tohold += txh->txh_memory_tohold; 1177 fudge += txh->txh_fudge; 1178 } 1179 1180 /* 1181 * If a snapshot has been taken since we made our estimates, 1182 * assume that we won't be able to free or overwrite anything. 1183 */ 1184 if (tx->tx_objset && 1185 dsl_dataset_prev_snap_txg(tx->tx_objset->os_dsl_dataset) > 1186 tx->tx_lastsnap_txg) { 1187 towrite += tooverwrite; 1188 tooverwrite = tofree = 0; 1189 } 1190 1191 /* needed allocation: worst-case estimate of write space */ 1192 asize = spa_get_asize(tx->tx_pool->dp_spa, towrite + tooverwrite); 1193 /* freed space estimate: worst-case overwrite + free estimate */ 1194 fsize = spa_get_asize(tx->tx_pool->dp_spa, tooverwrite) + tofree; 1195 /* convert unrefd space to worst-case estimate */ 1196 usize = spa_get_asize(tx->tx_pool->dp_spa, tounref); 1197 /* calculate memory footprint estimate */ 1198 memory = towrite + tooverwrite + tohold; 1199 1200 #ifdef ZFS_DEBUG 1201 /* 1202 * Add in 'tohold' to account for our dirty holds on this memory 1203 * XXX - the "fudge" factor is to account for skipped blocks that 1204 * we missed because dnode_next_offset() misses in-core-only blocks. 1205 */ 1206 tx->tx_space_towrite = asize + 1207 spa_get_asize(tx->tx_pool->dp_spa, tohold + fudge); 1208 tx->tx_space_tofree = tofree; 1209 tx->tx_space_tooverwrite = tooverwrite; 1210 tx->tx_space_tounref = tounref; 1211 #endif 1212 1213 if (tx->tx_dir && asize != 0) { 1214 int err = dsl_dir_tempreserve_space(tx->tx_dir, memory, 1215 asize, fsize, usize, &tx->tx_tempreserve_cookie, tx); 1216 if (err) 1217 return (err); 1218 } 1219 1220 return (0); 1221 } 1222 1223 static void 1224 dmu_tx_unassign(dmu_tx_t *tx) 1225 { 1226 dmu_tx_hold_t *txh; 1227 1228 if (tx->tx_txg == 0) 1229 return; 1230 1231 txg_rele_to_quiesce(&tx->tx_txgh); 1232 1233 /* 1234 * Walk the transaction's hold list, removing the hold on the 1235 * associated dnode, and notifying waiters if the refcount drops to 0. 1236 */ 1237 for (txh = list_head(&tx->tx_holds); txh != tx->tx_needassign_txh; 1238 txh = list_next(&tx->tx_holds, txh)) { 1239 dnode_t *dn = txh->txh_dnode; 1240 1241 if (dn == NULL) 1242 continue; 1243 mutex_enter(&dn->dn_mtx); 1244 ASSERT3U(dn->dn_assigned_txg, ==, tx->tx_txg); 1245 1246 if (refcount_remove(&dn->dn_tx_holds, tx) == 0) { 1247 dn->dn_assigned_txg = 0; 1248 cv_broadcast(&dn->dn_notxholds); 1249 } 1250 mutex_exit(&dn->dn_mtx); 1251 } 1252 1253 txg_rele_to_sync(&tx->tx_txgh); 1254 1255 tx->tx_lasttried_txg = tx->tx_txg; 1256 tx->tx_txg = 0; 1257 } 1258 1259 /* 1260 * Assign tx to a transaction group. txg_how can be one of: 1261 * 1262 * (1) TXG_WAIT. If the current open txg is full, waits until there's 1263 * a new one. This should be used when you're not holding locks. 1264 * It will only fail if we're truly out of space (or over quota). 1265 * 1266 * (2) TXG_NOWAIT. If we can't assign into the current open txg without 1267 * blocking, returns immediately with ERESTART. This should be used 1268 * whenever you're holding locks. On an ERESTART error, the caller 1269 * should drop locks, do a dmu_tx_wait(tx), and try again. 1270 * 1271 * (3) TXG_WAITED. Like TXG_NOWAIT, but indicates that dmu_tx_wait() 1272 * has already been called on behalf of this operation (though 1273 * most likely on a different tx). 1274 */ 1275 int 1276 dmu_tx_assign(dmu_tx_t *tx, txg_how_t txg_how) 1277 { 1278 int err; 1279 1280 ASSERT(tx->tx_txg == 0); 1281 ASSERT(txg_how == TXG_WAIT || txg_how == TXG_NOWAIT || 1282 txg_how == TXG_WAITED); 1283 ASSERT(!dsl_pool_sync_context(tx->tx_pool)); 1284 1285 /* If we might wait, we must not hold the config lock. */ 1286 ASSERT(txg_how != TXG_WAIT || !dsl_pool_config_held(tx->tx_pool)); 1287 1288 if (txg_how == TXG_WAITED) 1289 tx->tx_waited = B_TRUE; 1290 1291 while ((err = dmu_tx_try_assign(tx, txg_how)) != 0) { 1292 dmu_tx_unassign(tx); 1293 1294 if (err != ERESTART || txg_how != TXG_WAIT) 1295 return (err); 1296 1297 dmu_tx_wait(tx); 1298 } 1299 1300 txg_rele_to_quiesce(&tx->tx_txgh); 1301 1302 return (0); 1303 } 1304 1305 void 1306 dmu_tx_wait(dmu_tx_t *tx) 1307 { 1308 spa_t *spa = tx->tx_pool->dp_spa; 1309 dsl_pool_t *dp = tx->tx_pool; 1310 1311 ASSERT(tx->tx_txg == 0); 1312 ASSERT(!dsl_pool_config_held(tx->tx_pool)); 1313 1314 if (tx->tx_wait_dirty) { 1315 /* 1316 * dmu_tx_try_assign() has determined that we need to wait 1317 * because we've consumed much or all of the dirty buffer 1318 * space. 1319 */ 1320 mutex_enter(&dp->dp_lock); 1321 while (dp->dp_dirty_total >= zfs_dirty_data_max) 1322 cv_wait(&dp->dp_spaceavail_cv, &dp->dp_lock); 1323 uint64_t dirty = dp->dp_dirty_total; 1324 mutex_exit(&dp->dp_lock); 1325 1326 dmu_tx_delay(tx, dirty); 1327 1328 tx->tx_wait_dirty = B_FALSE; 1329 1330 /* 1331 * Note: setting tx_waited only has effect if the caller 1332 * used TX_WAIT. Otherwise they are going to destroy 1333 * this tx and try again. The common case, zfs_write(), 1334 * uses TX_WAIT. 1335 */ 1336 tx->tx_waited = B_TRUE; 1337 } else if (spa_suspended(spa) || tx->tx_lasttried_txg == 0) { 1338 /* 1339 * If the pool is suspended we need to wait until it 1340 * is resumed. Note that it's possible that the pool 1341 * has become active after this thread has tried to 1342 * obtain a tx. If that's the case then tx_lasttried_txg 1343 * would not have been set. 1344 */ 1345 txg_wait_synced(dp, spa_last_synced_txg(spa) + 1); 1346 } else if (tx->tx_needassign_txh) { 1347 /* 1348 * A dnode is assigned to the quiescing txg. Wait for its 1349 * transaction to complete. 1350 */ 1351 dnode_t *dn = tx->tx_needassign_txh->txh_dnode; 1352 1353 mutex_enter(&dn->dn_mtx); 1354 while (dn->dn_assigned_txg == tx->tx_lasttried_txg - 1) 1355 cv_wait(&dn->dn_notxholds, &dn->dn_mtx); 1356 mutex_exit(&dn->dn_mtx); 1357 tx->tx_needassign_txh = NULL; 1358 } else { 1359 txg_wait_open(tx->tx_pool, tx->tx_lasttried_txg + 1); 1360 } 1361 } 1362 1363 void 1364 dmu_tx_willuse_space(dmu_tx_t *tx, int64_t delta) 1365 { 1366 #ifdef ZFS_DEBUG 1367 if (tx->tx_dir == NULL || delta == 0) 1368 return; 1369 1370 if (delta > 0) { 1371 ASSERT3U(refcount_count(&tx->tx_space_written) + delta, <=, 1372 tx->tx_space_towrite); 1373 (void) refcount_add_many(&tx->tx_space_written, delta, NULL); 1374 } else { 1375 (void) refcount_add_many(&tx->tx_space_freed, -delta, NULL); 1376 } 1377 #endif 1378 } 1379 1380 void 1381 dmu_tx_commit(dmu_tx_t *tx) 1382 { 1383 dmu_tx_hold_t *txh; 1384 1385 ASSERT(tx->tx_txg != 0); 1386 1387 /* 1388 * Go through the transaction's hold list and remove holds on 1389 * associated dnodes, notifying waiters if no holds remain. 1390 */ 1391 while (txh = list_head(&tx->tx_holds)) { 1392 dnode_t *dn = txh->txh_dnode; 1393 1394 list_remove(&tx->tx_holds, txh); 1395 kmem_free(txh, sizeof (dmu_tx_hold_t)); 1396 if (dn == NULL) 1397 continue; 1398 mutex_enter(&dn->dn_mtx); 1399 ASSERT3U(dn->dn_assigned_txg, ==, tx->tx_txg); 1400 1401 if (refcount_remove(&dn->dn_tx_holds, tx) == 0) { 1402 dn->dn_assigned_txg = 0; 1403 cv_broadcast(&dn->dn_notxholds); 1404 } 1405 mutex_exit(&dn->dn_mtx); 1406 dnode_rele(dn, tx); 1407 } 1408 1409 if (tx->tx_tempreserve_cookie) 1410 dsl_dir_tempreserve_clear(tx->tx_tempreserve_cookie, tx); 1411 1412 if (!list_is_empty(&tx->tx_callbacks)) 1413 txg_register_callbacks(&tx->tx_txgh, &tx->tx_callbacks); 1414 1415 if (tx->tx_anyobj == FALSE) 1416 txg_rele_to_sync(&tx->tx_txgh); 1417 1418 list_destroy(&tx->tx_callbacks); 1419 list_destroy(&tx->tx_holds); 1420 #ifdef ZFS_DEBUG 1421 dprintf("towrite=%llu written=%llu tofree=%llu freed=%llu\n", 1422 tx->tx_space_towrite, refcount_count(&tx->tx_space_written), 1423 tx->tx_space_tofree, refcount_count(&tx->tx_space_freed)); 1424 refcount_destroy_many(&tx->tx_space_written, 1425 refcount_count(&tx->tx_space_written)); 1426 refcount_destroy_many(&tx->tx_space_freed, 1427 refcount_count(&tx->tx_space_freed)); 1428 #endif 1429 kmem_free(tx, sizeof (dmu_tx_t)); 1430 } 1431 1432 void 1433 dmu_tx_abort(dmu_tx_t *tx) 1434 { 1435 dmu_tx_hold_t *txh; 1436 1437 ASSERT(tx->tx_txg == 0); 1438 1439 while (txh = list_head(&tx->tx_holds)) { 1440 dnode_t *dn = txh->txh_dnode; 1441 1442 list_remove(&tx->tx_holds, txh); 1443 kmem_free(txh, sizeof (dmu_tx_hold_t)); 1444 if (dn != NULL) 1445 dnode_rele(dn, tx); 1446 } 1447 1448 /* 1449 * Call any registered callbacks with an error code. 1450 */ 1451 if (!list_is_empty(&tx->tx_callbacks)) 1452 dmu_tx_do_callbacks(&tx->tx_callbacks, ECANCELED); 1453 1454 list_destroy(&tx->tx_callbacks); 1455 list_destroy(&tx->tx_holds); 1456 #ifdef ZFS_DEBUG 1457 refcount_destroy_many(&tx->tx_space_written, 1458 refcount_count(&tx->tx_space_written)); 1459 refcount_destroy_many(&tx->tx_space_freed, 1460 refcount_count(&tx->tx_space_freed)); 1461 #endif 1462 kmem_free(tx, sizeof (dmu_tx_t)); 1463 } 1464 1465 uint64_t 1466 dmu_tx_get_txg(dmu_tx_t *tx) 1467 { 1468 ASSERT(tx->tx_txg != 0); 1469 return (tx->tx_txg); 1470 } 1471 1472 dsl_pool_t * 1473 dmu_tx_pool(dmu_tx_t *tx) 1474 { 1475 ASSERT(tx->tx_pool != NULL); 1476 return (tx->tx_pool); 1477 } 1478 1479 1480 void 1481 dmu_tx_callback_register(dmu_tx_t *tx, dmu_tx_callback_func_t *func, void *data) 1482 { 1483 dmu_tx_callback_t *dcb; 1484 1485 dcb = kmem_alloc(sizeof (dmu_tx_callback_t), KM_SLEEP); 1486 1487 dcb->dcb_func = func; 1488 dcb->dcb_data = data; 1489 1490 list_insert_tail(&tx->tx_callbacks, dcb); 1491 } 1492 1493 /* 1494 * Call all the commit callbacks on a list, with a given error code. 1495 */ 1496 void 1497 dmu_tx_do_callbacks(list_t *cb_list, int error) 1498 { 1499 dmu_tx_callback_t *dcb; 1500 1501 while (dcb = list_head(cb_list)) { 1502 list_remove(cb_list, dcb); 1503 dcb->dcb_func(dcb->dcb_data, error); 1504 kmem_free(dcb, sizeof (dmu_tx_callback_t)); 1505 } 1506 } 1507 1508 /* 1509 * Interface to hold a bunch of attributes. 1510 * used for creating new files. 1511 * attrsize is the total size of all attributes 1512 * to be added during object creation 1513 * 1514 * For updating/adding a single attribute dmu_tx_hold_sa() should be used. 1515 */ 1516 1517 /* 1518 * hold necessary attribute name for attribute registration. 1519 * should be a very rare case where this is needed. If it does 1520 * happen it would only happen on the first write to the file system. 1521 */ 1522 static void 1523 dmu_tx_sa_registration_hold(sa_os_t *sa, dmu_tx_t *tx) 1524 { 1525 int i; 1526 1527 if (!sa->sa_need_attr_registration) 1528 return; 1529 1530 for (i = 0; i != sa->sa_num_attrs; i++) { 1531 if (!sa->sa_attr_table[i].sa_registered) { 1532 if (sa->sa_reg_attr_obj) 1533 dmu_tx_hold_zap(tx, sa->sa_reg_attr_obj, 1534 B_TRUE, sa->sa_attr_table[i].sa_name); 1535 else 1536 dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, 1537 B_TRUE, sa->sa_attr_table[i].sa_name); 1538 } 1539 } 1540 } 1541 1542 1543 void 1544 dmu_tx_hold_spill(dmu_tx_t *tx, uint64_t object) 1545 { 1546 dnode_t *dn; 1547 dmu_tx_hold_t *txh; 1548 1549 txh = dmu_tx_hold_object_impl(tx, tx->tx_objset, object, 1550 THT_SPILL, 0, 0); 1551 1552 dn = txh->txh_dnode; 1553 1554 if (dn == NULL) 1555 return; 1556 1557 /* If blkptr doesn't exist then add space to towrite */ 1558 if (!(dn->dn_phys->dn_flags & DNODE_FLAG_SPILL_BLKPTR)) { 1559 txh->txh_space_towrite += SPA_OLD_MAXBLOCKSIZE; 1560 } else { 1561 blkptr_t *bp; 1562 1563 bp = &dn->dn_phys->dn_spill; 1564 if (dsl_dataset_block_freeable(dn->dn_objset->os_dsl_dataset, 1565 bp, bp->blk_birth)) 1566 txh->txh_space_tooverwrite += SPA_OLD_MAXBLOCKSIZE; 1567 else 1568 txh->txh_space_towrite += SPA_OLD_MAXBLOCKSIZE; 1569 if (!BP_IS_HOLE(bp)) 1570 txh->txh_space_tounref += SPA_OLD_MAXBLOCKSIZE; 1571 } 1572 } 1573 1574 void 1575 dmu_tx_hold_sa_create(dmu_tx_t *tx, int attrsize) 1576 { 1577 sa_os_t *sa = tx->tx_objset->os_sa; 1578 1579 dmu_tx_hold_bonus(tx, DMU_NEW_OBJECT); 1580 1581 if (tx->tx_objset->os_sa->sa_master_obj == 0) 1582 return; 1583 1584 if (tx->tx_objset->os_sa->sa_layout_attr_obj) 1585 dmu_tx_hold_zap(tx, sa->sa_layout_attr_obj, B_TRUE, NULL); 1586 else { 1587 dmu_tx_hold_zap(tx, sa->sa_master_obj, B_TRUE, SA_LAYOUTS); 1588 dmu_tx_hold_zap(tx, sa->sa_master_obj, B_TRUE, SA_REGISTRY); 1589 dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, B_TRUE, NULL); 1590 dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, B_TRUE, NULL); 1591 } 1592 1593 dmu_tx_sa_registration_hold(sa, tx); 1594 1595 if (attrsize <= DN_MAX_BONUSLEN && !sa->sa_force_spill) 1596 return; 1597 1598 (void) dmu_tx_hold_object_impl(tx, tx->tx_objset, DMU_NEW_OBJECT, 1599 THT_SPILL, 0, 0); 1600 } 1601 1602 /* 1603 * Hold SA attribute 1604 * 1605 * dmu_tx_hold_sa(dmu_tx_t *tx, sa_handle_t *, attribute, add, size) 1606 * 1607 * variable_size is the total size of all variable sized attributes 1608 * passed to this function. It is not the total size of all 1609 * variable size attributes that *may* exist on this object. 1610 */ 1611 void 1612 dmu_tx_hold_sa(dmu_tx_t *tx, sa_handle_t *hdl, boolean_t may_grow) 1613 { 1614 uint64_t object; 1615 sa_os_t *sa = tx->tx_objset->os_sa; 1616 1617 ASSERT(hdl != NULL); 1618 1619 object = sa_handle_object(hdl); 1620 1621 dmu_tx_hold_bonus(tx, object); 1622 1623 if (tx->tx_objset->os_sa->sa_master_obj == 0) 1624 return; 1625 1626 if (tx->tx_objset->os_sa->sa_reg_attr_obj == 0 || 1627 tx->tx_objset->os_sa->sa_layout_attr_obj == 0) { 1628 dmu_tx_hold_zap(tx, sa->sa_master_obj, B_TRUE, SA_LAYOUTS); 1629 dmu_tx_hold_zap(tx, sa->sa_master_obj, B_TRUE, SA_REGISTRY); 1630 dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, B_TRUE, NULL); 1631 dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, B_TRUE, NULL); 1632 } 1633 1634 dmu_tx_sa_registration_hold(sa, tx); 1635 1636 if (may_grow && tx->tx_objset->os_sa->sa_layout_attr_obj) 1637 dmu_tx_hold_zap(tx, sa->sa_layout_attr_obj, B_TRUE, NULL); 1638 1639 if (sa->sa_force_spill || may_grow || hdl->sa_spill) { 1640 ASSERT(tx->tx_txg == 0); 1641 dmu_tx_hold_spill(tx, object); 1642 } else { 1643 dmu_buf_impl_t *db = (dmu_buf_impl_t *)hdl->sa_bonus; 1644 dnode_t *dn; 1645 1646 DB_DNODE_ENTER(db); 1647 dn = DB_DNODE(db); 1648 if (dn->dn_have_spill) { 1649 ASSERT(tx->tx_txg == 0); 1650 dmu_tx_hold_spill(tx, object); 1651 } 1652 DB_DNODE_EXIT(db); 1653 } 1654 } 1655