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