1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 /* 22 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. 23 * Copyright 2011 Nexenta Systems, Inc. All rights reserved. 24 * Copyright (c) 2013 by Delphix. All rights reserved. 25 */ 26 27 #include <sys/dmu.h> 28 #include <sys/dmu_impl.h> 29 #include <sys/dbuf.h> 30 #include <sys/dmu_tx.h> 31 #include <sys/dmu_objset.h> 32 #include <sys/dsl_dataset.h> /* for dsl_dataset_block_freeable() */ 33 #include <sys/dsl_dir.h> /* for dsl_dir_tempreserve_*() */ 34 #include <sys/dsl_pool.h> 35 #include <sys/zap_impl.h> /* for fzap_default_block_shift */ 36 #include <sys/spa.h> 37 #include <sys/sa.h> 38 #include <sys/sa_impl.h> 39 #include <sys/zfs_context.h> 40 #include <sys/varargs.h> 41 42 typedef void (*dmu_tx_hold_func_t)(dmu_tx_t *tx, struct dnode *dn, 43 uint64_t arg1, uint64_t arg2); 44 45 46 dmu_tx_t * 47 dmu_tx_create_dd(dsl_dir_t *dd) 48 { 49 dmu_tx_t *tx = kmem_zalloc(sizeof (dmu_tx_t), KM_SLEEP); 50 tx->tx_dir = dd; 51 if (dd != NULL) 52 tx->tx_pool = dd->dd_pool; 53 list_create(&tx->tx_holds, sizeof (dmu_tx_hold_t), 54 offsetof(dmu_tx_hold_t, txh_node)); 55 list_create(&tx->tx_callbacks, sizeof (dmu_tx_callback_t), 56 offsetof(dmu_tx_callback_t, dcb_node)); 57 tx->tx_start = gethrtime(); 58 #ifdef ZFS_DEBUG 59 refcount_create(&tx->tx_space_written); 60 refcount_create(&tx->tx_space_freed); 61 #endif 62 return (tx); 63 } 64 65 dmu_tx_t * 66 dmu_tx_create(objset_t *os) 67 { 68 dmu_tx_t *tx = dmu_tx_create_dd(os->os_dsl_dataset->ds_dir); 69 tx->tx_objset = os; 70 tx->tx_lastsnap_txg = dsl_dataset_prev_snap_txg(os->os_dsl_dataset); 71 return (tx); 72 } 73 74 dmu_tx_t * 75 dmu_tx_create_assigned(struct dsl_pool *dp, uint64_t txg) 76 { 77 dmu_tx_t *tx = dmu_tx_create_dd(NULL); 78 79 ASSERT3U(txg, <=, dp->dp_tx.tx_open_txg); 80 tx->tx_pool = dp; 81 tx->tx_txg = txg; 82 tx->tx_anyobj = TRUE; 83 84 return (tx); 85 } 86 87 int 88 dmu_tx_is_syncing(dmu_tx_t *tx) 89 { 90 return (tx->tx_anyobj); 91 } 92 93 int 94 dmu_tx_private_ok(dmu_tx_t *tx) 95 { 96 return (tx->tx_anyobj); 97 } 98 99 static dmu_tx_hold_t * 100 dmu_tx_hold_object_impl(dmu_tx_t *tx, objset_t *os, uint64_t object, 101 enum dmu_tx_hold_type type, uint64_t arg1, uint64_t arg2) 102 { 103 dmu_tx_hold_t *txh; 104 dnode_t *dn = NULL; 105 int err; 106 107 if (object != DMU_NEW_OBJECT) { 108 err = dnode_hold(os, object, tx, &dn); 109 if (err) { 110 tx->tx_err = err; 111 return (NULL); 112 } 113 114 if (err == 0 && tx->tx_txg != 0) { 115 mutex_enter(&dn->dn_mtx); 116 /* 117 * dn->dn_assigned_txg == tx->tx_txg doesn't pose a 118 * problem, but there's no way for it to happen (for 119 * now, at least). 120 */ 121 ASSERT(dn->dn_assigned_txg == 0); 122 dn->dn_assigned_txg = tx->tx_txg; 123 (void) refcount_add(&dn->dn_tx_holds, tx); 124 mutex_exit(&dn->dn_mtx); 125 } 126 } 127 128 txh = kmem_zalloc(sizeof (dmu_tx_hold_t), KM_SLEEP); 129 txh->txh_tx = tx; 130 txh->txh_dnode = dn; 131 #ifdef ZFS_DEBUG 132 txh->txh_type = type; 133 txh->txh_arg1 = arg1; 134 txh->txh_arg2 = arg2; 135 #endif 136 list_insert_tail(&tx->tx_holds, txh); 137 138 return (txh); 139 } 140 141 void 142 dmu_tx_add_new_object(dmu_tx_t *tx, objset_t *os, uint64_t object) 143 { 144 /* 145 * If we're syncing, they can manipulate any object anyhow, and 146 * the hold on the dnode_t can cause problems. 147 */ 148 if (!dmu_tx_is_syncing(tx)) { 149 (void) dmu_tx_hold_object_impl(tx, os, 150 object, THT_NEWOBJECT, 0, 0); 151 } 152 } 153 154 static int 155 dmu_tx_check_ioerr(zio_t *zio, dnode_t *dn, int level, uint64_t blkid) 156 { 157 int err; 158 dmu_buf_impl_t *db; 159 160 rw_enter(&dn->dn_struct_rwlock, RW_READER); 161 db = dbuf_hold_level(dn, level, blkid, FTAG); 162 rw_exit(&dn->dn_struct_rwlock); 163 if (db == NULL) 164 return (SET_ERROR(EIO)); 165 err = dbuf_read(db, zio, DB_RF_CANFAIL | DB_RF_NOPREFETCH); 166 dbuf_rele(db, FTAG); 167 return (err); 168 } 169 170 static void 171 dmu_tx_count_twig(dmu_tx_hold_t *txh, dnode_t *dn, dmu_buf_impl_t *db, 172 int level, uint64_t blkid, boolean_t freeable, uint64_t *history) 173 { 174 objset_t *os = dn->dn_objset; 175 dsl_dataset_t *ds = os->os_dsl_dataset; 176 int epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT; 177 dmu_buf_impl_t *parent = NULL; 178 blkptr_t *bp = NULL; 179 uint64_t space; 180 181 if (level >= dn->dn_nlevels || history[level] == blkid) 182 return; 183 184 history[level] = blkid; 185 186 space = (level == 0) ? dn->dn_datablksz : (1ULL << dn->dn_indblkshift); 187 188 if (db == NULL || db == dn->dn_dbuf) { 189 ASSERT(level != 0); 190 db = NULL; 191 } else { 192 ASSERT(DB_DNODE(db) == dn); 193 ASSERT(db->db_level == level); 194 ASSERT(db->db.db_size == space); 195 ASSERT(db->db_blkid == blkid); 196 bp = db->db_blkptr; 197 parent = db->db_parent; 198 } 199 200 freeable = (bp && (freeable || 201 dsl_dataset_block_freeable(ds, bp, bp->blk_birth))); 202 203 if (freeable) 204 txh->txh_space_tooverwrite += space; 205 else 206 txh->txh_space_towrite += space; 207 if (bp) 208 txh->txh_space_tounref += bp_get_dsize(os->os_spa, bp); 209 210 dmu_tx_count_twig(txh, dn, parent, level + 1, 211 blkid >> epbs, freeable, history); 212 } 213 214 /* ARGSUSED */ 215 static void 216 dmu_tx_count_write(dmu_tx_hold_t *txh, uint64_t off, uint64_t len) 217 { 218 dnode_t *dn = txh->txh_dnode; 219 uint64_t start, end, i; 220 int min_bs, max_bs, min_ibs, max_ibs, epbs, bits; 221 int err = 0; 222 223 if (len == 0) 224 return; 225 226 min_bs = SPA_MINBLOCKSHIFT; 227 max_bs = SPA_MAXBLOCKSHIFT; 228 min_ibs = DN_MIN_INDBLKSHIFT; 229 max_ibs = DN_MAX_INDBLKSHIFT; 230 231 if (dn) { 232 uint64_t history[DN_MAX_LEVELS]; 233 int nlvls = dn->dn_nlevels; 234 int delta; 235 236 /* 237 * For i/o error checking, read the first and last level-0 238 * blocks (if they are not aligned), and all the level-1 blocks. 239 */ 240 if (dn->dn_maxblkid == 0) { 241 delta = dn->dn_datablksz; 242 start = (off < dn->dn_datablksz) ? 0 : 1; 243 end = (off+len <= dn->dn_datablksz) ? 0 : 1; 244 if (start == 0 && (off > 0 || len < dn->dn_datablksz)) { 245 err = dmu_tx_check_ioerr(NULL, dn, 0, 0); 246 if (err) 247 goto out; 248 delta -= off; 249 } 250 } else { 251 zio_t *zio = zio_root(dn->dn_objset->os_spa, 252 NULL, NULL, ZIO_FLAG_CANFAIL); 253 254 /* first level-0 block */ 255 start = off >> dn->dn_datablkshift; 256 if (P2PHASE(off, dn->dn_datablksz) || 257 len < dn->dn_datablksz) { 258 err = dmu_tx_check_ioerr(zio, dn, 0, start); 259 if (err) 260 goto out; 261 } 262 263 /* last level-0 block */ 264 end = (off+len-1) >> dn->dn_datablkshift; 265 if (end != start && end <= dn->dn_maxblkid && 266 P2PHASE(off+len, dn->dn_datablksz)) { 267 err = dmu_tx_check_ioerr(zio, dn, 0, end); 268 if (err) 269 goto out; 270 } 271 272 /* level-1 blocks */ 273 if (nlvls > 1) { 274 int shft = dn->dn_indblkshift - SPA_BLKPTRSHIFT; 275 for (i = (start>>shft)+1; i < end>>shft; i++) { 276 err = dmu_tx_check_ioerr(zio, dn, 1, i); 277 if (err) 278 goto out; 279 } 280 } 281 282 err = zio_wait(zio); 283 if (err) 284 goto out; 285 delta = P2NPHASE(off, dn->dn_datablksz); 286 } 287 288 min_ibs = max_ibs = dn->dn_indblkshift; 289 if (dn->dn_maxblkid > 0) { 290 /* 291 * The blocksize can't change, 292 * so we can make a more precise estimate. 293 */ 294 ASSERT(dn->dn_datablkshift != 0); 295 min_bs = max_bs = dn->dn_datablkshift; 296 } 297 298 /* 299 * If this write is not off the end of the file 300 * we need to account for overwrites/unref. 301 */ 302 if (start <= dn->dn_maxblkid) { 303 for (int l = 0; l < DN_MAX_LEVELS; l++) 304 history[l] = -1ULL; 305 } 306 while (start <= dn->dn_maxblkid) { 307 dmu_buf_impl_t *db; 308 309 rw_enter(&dn->dn_struct_rwlock, RW_READER); 310 err = dbuf_hold_impl(dn, 0, start, FALSE, FTAG, &db); 311 rw_exit(&dn->dn_struct_rwlock); 312 313 if (err) { 314 txh->txh_tx->tx_err = err; 315 return; 316 } 317 318 dmu_tx_count_twig(txh, dn, db, 0, start, B_FALSE, 319 history); 320 dbuf_rele(db, FTAG); 321 if (++start > end) { 322 /* 323 * Account for new indirects appearing 324 * before this IO gets assigned into a txg. 325 */ 326 bits = 64 - min_bs; 327 epbs = min_ibs - SPA_BLKPTRSHIFT; 328 for (bits -= epbs * (nlvls - 1); 329 bits >= 0; bits -= epbs) 330 txh->txh_fudge += 1ULL << max_ibs; 331 goto out; 332 } 333 off += delta; 334 if (len >= delta) 335 len -= delta; 336 delta = dn->dn_datablksz; 337 } 338 } 339 340 /* 341 * 'end' is the last thing we will access, not one past. 342 * This way we won't overflow when accessing the last byte. 343 */ 344 start = P2ALIGN(off, 1ULL << max_bs); 345 end = P2ROUNDUP(off + len, 1ULL << max_bs) - 1; 346 txh->txh_space_towrite += end - start + 1; 347 348 start >>= min_bs; 349 end >>= min_bs; 350 351 epbs = min_ibs - SPA_BLKPTRSHIFT; 352 353 /* 354 * The object contains at most 2^(64 - min_bs) blocks, 355 * and each indirect level maps 2^epbs. 356 */ 357 for (bits = 64 - min_bs; bits >= 0; bits -= epbs) { 358 start >>= epbs; 359 end >>= epbs; 360 ASSERT3U(end, >=, start); 361 txh->txh_space_towrite += (end - start + 1) << max_ibs; 362 if (start != 0) { 363 /* 364 * We also need a new blkid=0 indirect block 365 * to reference any existing file data. 366 */ 367 txh->txh_space_towrite += 1ULL << max_ibs; 368 } 369 } 370 371 out: 372 if (txh->txh_space_towrite + txh->txh_space_tooverwrite > 373 2 * DMU_MAX_ACCESS) 374 err = SET_ERROR(EFBIG); 375 376 if (err) 377 txh->txh_tx->tx_err = err; 378 } 379 380 static void 381 dmu_tx_count_dnode(dmu_tx_hold_t *txh) 382 { 383 dnode_t *dn = txh->txh_dnode; 384 dnode_t *mdn = DMU_META_DNODE(txh->txh_tx->tx_objset); 385 uint64_t space = mdn->dn_datablksz + 386 ((mdn->dn_nlevels-1) << mdn->dn_indblkshift); 387 388 if (dn && dn->dn_dbuf->db_blkptr && 389 dsl_dataset_block_freeable(dn->dn_objset->os_dsl_dataset, 390 dn->dn_dbuf->db_blkptr, dn->dn_dbuf->db_blkptr->blk_birth)) { 391 txh->txh_space_tooverwrite += space; 392 txh->txh_space_tounref += space; 393 } else { 394 txh->txh_space_towrite += space; 395 if (dn && dn->dn_dbuf->db_blkptr) 396 txh->txh_space_tounref += space; 397 } 398 } 399 400 void 401 dmu_tx_hold_write(dmu_tx_t *tx, uint64_t object, uint64_t off, int len) 402 { 403 dmu_tx_hold_t *txh; 404 405 ASSERT(tx->tx_txg == 0); 406 ASSERT(len < DMU_MAX_ACCESS); 407 ASSERT(len == 0 || UINT64_MAX - off >= len - 1); 408 409 txh = dmu_tx_hold_object_impl(tx, tx->tx_objset, 410 object, THT_WRITE, off, len); 411 if (txh == NULL) 412 return; 413 414 dmu_tx_count_write(txh, off, len); 415 dmu_tx_count_dnode(txh); 416 } 417 418 static void 419 dmu_tx_count_free(dmu_tx_hold_t *txh, uint64_t off, uint64_t len) 420 { 421 uint64_t blkid, nblks, lastblk; 422 uint64_t space = 0, unref = 0, skipped = 0; 423 dnode_t *dn = txh->txh_dnode; 424 dsl_dataset_t *ds = dn->dn_objset->os_dsl_dataset; 425 spa_t *spa = txh->txh_tx->tx_pool->dp_spa; 426 int epbs; 427 uint64_t l0span = 0, nl1blks = 0; 428 429 if (dn->dn_nlevels == 0) 430 return; 431 432 /* 433 * The struct_rwlock protects us against dn_nlevels 434 * changing, in case (against all odds) we manage to dirty & 435 * sync out the changes after we check for being dirty. 436 * Also, dbuf_hold_impl() wants us to have the struct_rwlock. 437 */ 438 rw_enter(&dn->dn_struct_rwlock, RW_READER); 439 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT; 440 if (dn->dn_maxblkid == 0) { 441 if (off == 0 && len >= dn->dn_datablksz) { 442 blkid = 0; 443 nblks = 1; 444 } else { 445 rw_exit(&dn->dn_struct_rwlock); 446 return; 447 } 448 } else { 449 blkid = off >> dn->dn_datablkshift; 450 nblks = (len + dn->dn_datablksz - 1) >> dn->dn_datablkshift; 451 452 if (blkid > dn->dn_maxblkid) { 453 rw_exit(&dn->dn_struct_rwlock); 454 return; 455 } 456 if (blkid + nblks > dn->dn_maxblkid) 457 nblks = dn->dn_maxblkid - blkid + 1; 458 459 } 460 l0span = nblks; /* save for later use to calc level > 1 overhead */ 461 if (dn->dn_nlevels == 1) { 462 int i; 463 for (i = 0; i < nblks; i++) { 464 blkptr_t *bp = dn->dn_phys->dn_blkptr; 465 ASSERT3U(blkid + i, <, dn->dn_nblkptr); 466 bp += blkid + i; 467 if (dsl_dataset_block_freeable(ds, bp, bp->blk_birth)) { 468 dprintf_bp(bp, "can free old%s", ""); 469 space += bp_get_dsize(spa, bp); 470 } 471 unref += BP_GET_ASIZE(bp); 472 } 473 nl1blks = 1; 474 nblks = 0; 475 } 476 477 lastblk = blkid + nblks - 1; 478 while (nblks) { 479 dmu_buf_impl_t *dbuf; 480 uint64_t ibyte, new_blkid; 481 int epb = 1 << epbs; 482 int err, i, blkoff, tochk; 483 blkptr_t *bp; 484 485 ibyte = blkid << dn->dn_datablkshift; 486 err = dnode_next_offset(dn, 487 DNODE_FIND_HAVELOCK, &ibyte, 2, 1, 0); 488 new_blkid = ibyte >> dn->dn_datablkshift; 489 if (err == ESRCH) { 490 skipped += (lastblk >> epbs) - (blkid >> epbs) + 1; 491 break; 492 } 493 if (err) { 494 txh->txh_tx->tx_err = err; 495 break; 496 } 497 if (new_blkid > lastblk) { 498 skipped += (lastblk >> epbs) - (blkid >> epbs) + 1; 499 break; 500 } 501 502 if (new_blkid > blkid) { 503 ASSERT((new_blkid >> epbs) > (blkid >> epbs)); 504 skipped += (new_blkid >> epbs) - (blkid >> epbs) - 1; 505 nblks -= new_blkid - blkid; 506 blkid = new_blkid; 507 } 508 blkoff = P2PHASE(blkid, epb); 509 tochk = MIN(epb - blkoff, nblks); 510 511 err = dbuf_hold_impl(dn, 1, blkid >> epbs, FALSE, FTAG, &dbuf); 512 if (err) { 513 txh->txh_tx->tx_err = err; 514 break; 515 } 516 517 txh->txh_memory_tohold += dbuf->db.db_size; 518 519 /* 520 * We don't check memory_tohold against DMU_MAX_ACCESS because 521 * memory_tohold is an over-estimation (especially the >L1 522 * indirect blocks), so it could fail. Callers should have 523 * already verified that they will not be holding too much 524 * memory. 525 */ 526 527 err = dbuf_read(dbuf, NULL, DB_RF_HAVESTRUCT | DB_RF_CANFAIL); 528 if (err != 0) { 529 txh->txh_tx->tx_err = err; 530 dbuf_rele(dbuf, FTAG); 531 break; 532 } 533 534 bp = dbuf->db.db_data; 535 bp += blkoff; 536 537 for (i = 0; i < tochk; i++) { 538 if (dsl_dataset_block_freeable(ds, &bp[i], 539 bp[i].blk_birth)) { 540 dprintf_bp(&bp[i], "can free old%s", ""); 541 space += bp_get_dsize(spa, &bp[i]); 542 } 543 unref += BP_GET_ASIZE(bp); 544 } 545 dbuf_rele(dbuf, FTAG); 546 547 ++nl1blks; 548 blkid += tochk; 549 nblks -= tochk; 550 } 551 rw_exit(&dn->dn_struct_rwlock); 552 553 /* 554 * Add in memory requirements of higher-level indirects. 555 * This assumes a worst-possible scenario for dn_nlevels and a 556 * worst-possible distribution of l1-blocks over the region to free. 557 */ 558 { 559 uint64_t blkcnt = 1 + ((l0span >> epbs) >> epbs); 560 int level = 2; 561 /* 562 * Here we don't use DN_MAX_LEVEL, but calculate it with the 563 * given datablkshift and indblkshift. This makes the 564 * difference between 19 and 8 on large files. 565 */ 566 int maxlevel = 2 + (DN_MAX_OFFSET_SHIFT - dn->dn_datablkshift) / 567 (dn->dn_indblkshift - SPA_BLKPTRSHIFT); 568 569 while (level++ < maxlevel) { 570 txh->txh_memory_tohold += MAX(MIN(blkcnt, nl1blks), 1) 571 << dn->dn_indblkshift; 572 blkcnt = 1 + (blkcnt >> epbs); 573 } 574 } 575 576 /* account for new level 1 indirect blocks that might show up */ 577 if (skipped > 0) { 578 txh->txh_fudge += skipped << dn->dn_indblkshift; 579 skipped = MIN(skipped, DMU_MAX_DELETEBLKCNT >> epbs); 580 txh->txh_memory_tohold += skipped << dn->dn_indblkshift; 581 } 582 txh->txh_space_tofree += space; 583 txh->txh_space_tounref += unref; 584 } 585 586 void 587 dmu_tx_hold_free(dmu_tx_t *tx, uint64_t object, uint64_t off, uint64_t len) 588 { 589 dmu_tx_hold_t *txh; 590 dnode_t *dn; 591 int err; 592 zio_t *zio; 593 594 ASSERT(tx->tx_txg == 0); 595 596 txh = dmu_tx_hold_object_impl(tx, tx->tx_objset, 597 object, THT_FREE, off, len); 598 if (txh == NULL) 599 return; 600 dn = txh->txh_dnode; 601 dmu_tx_count_dnode(txh); 602 603 if (off >= (dn->dn_maxblkid+1) * dn->dn_datablksz) 604 return; 605 if (len == DMU_OBJECT_END) 606 len = (dn->dn_maxblkid+1) * dn->dn_datablksz - off; 607 608 /* 609 * For i/o error checking, we read the first and last level-0 610 * blocks if they are not aligned, and all the level-1 blocks. 611 * 612 * Note: dbuf_free_range() assumes that we have not instantiated 613 * any level-0 dbufs that will be completely freed. Therefore we must 614 * exercise care to not read or count the first and last blocks 615 * if they are blocksize-aligned. 616 */ 617 if (dn->dn_datablkshift == 0) { 618 if (off != 0 || len < dn->dn_datablksz) 619 dmu_tx_count_write(txh, 0, dn->dn_datablksz); 620 } else { 621 /* first block will be modified if it is not aligned */ 622 if (!IS_P2ALIGNED(off, 1 << dn->dn_datablkshift)) 623 dmu_tx_count_write(txh, off, 1); 624 /* last block will be modified if it is not aligned */ 625 if (!IS_P2ALIGNED(off + len, 1 << dn->dn_datablkshift)) 626 dmu_tx_count_write(txh, off+len, 1); 627 } 628 629 /* 630 * Check level-1 blocks. 631 */ 632 if (dn->dn_nlevels > 1) { 633 int shift = dn->dn_datablkshift + dn->dn_indblkshift - 634 SPA_BLKPTRSHIFT; 635 uint64_t start = off >> shift; 636 uint64_t end = (off + len) >> shift; 637 638 ASSERT(dn->dn_indblkshift != 0); 639 640 /* 641 * dnode_reallocate() can result in an object with indirect 642 * blocks having an odd data block size. In this case, 643 * just check the single block. 644 */ 645 if (dn->dn_datablkshift == 0) 646 start = end = 0; 647 648 zio = zio_root(tx->tx_pool->dp_spa, 649 NULL, NULL, ZIO_FLAG_CANFAIL); 650 for (uint64_t i = start; i <= end; i++) { 651 uint64_t ibyte = i << shift; 652 err = dnode_next_offset(dn, 0, &ibyte, 2, 1, 0); 653 i = ibyte >> shift; 654 if (err == ESRCH) 655 break; 656 if (err) { 657 tx->tx_err = err; 658 return; 659 } 660 661 err = dmu_tx_check_ioerr(zio, dn, 1, i); 662 if (err) { 663 tx->tx_err = err; 664 return; 665 } 666 } 667 err = zio_wait(zio); 668 if (err) { 669 tx->tx_err = err; 670 return; 671 } 672 } 673 674 dmu_tx_count_free(txh, off, len); 675 } 676 677 void 678 dmu_tx_hold_zap(dmu_tx_t *tx, uint64_t object, int add, const char *name) 679 { 680 dmu_tx_hold_t *txh; 681 dnode_t *dn; 682 uint64_t nblocks; 683 int epbs, err; 684 685 ASSERT(tx->tx_txg == 0); 686 687 txh = dmu_tx_hold_object_impl(tx, tx->tx_objset, 688 object, THT_ZAP, add, (uintptr_t)name); 689 if (txh == NULL) 690 return; 691 dn = txh->txh_dnode; 692 693 dmu_tx_count_dnode(txh); 694 695 if (dn == NULL) { 696 /* 697 * We will be able to fit a new object's entries into one leaf 698 * block. So there will be at most 2 blocks total, 699 * including the header block. 700 */ 701 dmu_tx_count_write(txh, 0, 2 << fzap_default_block_shift); 702 return; 703 } 704 705 ASSERT3P(DMU_OT_BYTESWAP(dn->dn_type), ==, DMU_BSWAP_ZAP); 706 707 if (dn->dn_maxblkid == 0 && !add) { 708 blkptr_t *bp; 709 710 /* 711 * If there is only one block (i.e. this is a micro-zap) 712 * and we are not adding anything, the accounting is simple. 713 */ 714 err = dmu_tx_check_ioerr(NULL, dn, 0, 0); 715 if (err) { 716 tx->tx_err = err; 717 return; 718 } 719 720 /* 721 * Use max block size here, since we don't know how much 722 * the size will change between now and the dbuf dirty call. 723 */ 724 bp = &dn->dn_phys->dn_blkptr[0]; 725 if (dsl_dataset_block_freeable(dn->dn_objset->os_dsl_dataset, 726 bp, bp->blk_birth)) 727 txh->txh_space_tooverwrite += SPA_MAXBLOCKSIZE; 728 else 729 txh->txh_space_towrite += SPA_MAXBLOCKSIZE; 730 if (!BP_IS_HOLE(bp)) 731 txh->txh_space_tounref += SPA_MAXBLOCKSIZE; 732 return; 733 } 734 735 if (dn->dn_maxblkid > 0 && name) { 736 /* 737 * access the name in this fat-zap so that we'll check 738 * for i/o errors to the leaf blocks, etc. 739 */ 740 err = zap_lookup(dn->dn_objset, dn->dn_object, name, 741 8, 0, NULL); 742 if (err == EIO) { 743 tx->tx_err = err; 744 return; 745 } 746 } 747 748 err = zap_count_write(dn->dn_objset, dn->dn_object, name, add, 749 &txh->txh_space_towrite, &txh->txh_space_tooverwrite); 750 751 /* 752 * If the modified blocks are scattered to the four winds, 753 * we'll have to modify an indirect twig for each. 754 */ 755 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT; 756 for (nblocks = dn->dn_maxblkid >> epbs; nblocks != 0; nblocks >>= epbs) 757 if (dn->dn_objset->os_dsl_dataset->ds_phys->ds_prev_snap_obj) 758 txh->txh_space_towrite += 3 << dn->dn_indblkshift; 759 else 760 txh->txh_space_tooverwrite += 3 << dn->dn_indblkshift; 761 } 762 763 void 764 dmu_tx_hold_bonus(dmu_tx_t *tx, uint64_t object) 765 { 766 dmu_tx_hold_t *txh; 767 768 ASSERT(tx->tx_txg == 0); 769 770 txh = dmu_tx_hold_object_impl(tx, tx->tx_objset, 771 object, THT_BONUS, 0, 0); 772 if (txh) 773 dmu_tx_count_dnode(txh); 774 } 775 776 void 777 dmu_tx_hold_space(dmu_tx_t *tx, uint64_t space) 778 { 779 dmu_tx_hold_t *txh; 780 ASSERT(tx->tx_txg == 0); 781 782 txh = dmu_tx_hold_object_impl(tx, tx->tx_objset, 783 DMU_NEW_OBJECT, THT_SPACE, space, 0); 784 785 txh->txh_space_towrite += space; 786 } 787 788 int 789 dmu_tx_holds(dmu_tx_t *tx, uint64_t object) 790 { 791 dmu_tx_hold_t *txh; 792 int holds = 0; 793 794 /* 795 * By asserting that the tx is assigned, we're counting the 796 * number of dn_tx_holds, which is the same as the number of 797 * dn_holds. Otherwise, we'd be counting dn_holds, but 798 * dn_tx_holds could be 0. 799 */ 800 ASSERT(tx->tx_txg != 0); 801 802 /* if (tx->tx_anyobj == TRUE) */ 803 /* return (0); */ 804 805 for (txh = list_head(&tx->tx_holds); txh; 806 txh = list_next(&tx->tx_holds, txh)) { 807 if (txh->txh_dnode && txh->txh_dnode->dn_object == object) 808 holds++; 809 } 810 811 return (holds); 812 } 813 814 #ifdef ZFS_DEBUG 815 void 816 dmu_tx_dirty_buf(dmu_tx_t *tx, dmu_buf_impl_t *db) 817 { 818 dmu_tx_hold_t *txh; 819 int match_object = FALSE, match_offset = FALSE; 820 dnode_t *dn; 821 822 DB_DNODE_ENTER(db); 823 dn = DB_DNODE(db); 824 ASSERT(tx->tx_txg != 0); 825 ASSERT(tx->tx_objset == NULL || dn->dn_objset == tx->tx_objset); 826 ASSERT3U(dn->dn_object, ==, db->db.db_object); 827 828 if (tx->tx_anyobj) { 829 DB_DNODE_EXIT(db); 830 return; 831 } 832 833 /* XXX No checking on the meta dnode for now */ 834 if (db->db.db_object == DMU_META_DNODE_OBJECT) { 835 DB_DNODE_EXIT(db); 836 return; 837 } 838 839 for (txh = list_head(&tx->tx_holds); txh; 840 txh = list_next(&tx->tx_holds, txh)) { 841 ASSERT(dn == NULL || dn->dn_assigned_txg == tx->tx_txg); 842 if (txh->txh_dnode == dn && txh->txh_type != THT_NEWOBJECT) 843 match_object = TRUE; 844 if (txh->txh_dnode == NULL || txh->txh_dnode == dn) { 845 int datablkshift = dn->dn_datablkshift ? 846 dn->dn_datablkshift : SPA_MAXBLOCKSHIFT; 847 int epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT; 848 int shift = datablkshift + epbs * db->db_level; 849 uint64_t beginblk = shift >= 64 ? 0 : 850 (txh->txh_arg1 >> shift); 851 uint64_t endblk = shift >= 64 ? 0 : 852 ((txh->txh_arg1 + txh->txh_arg2 - 1) >> shift); 853 uint64_t blkid = db->db_blkid; 854 855 /* XXX txh_arg2 better not be zero... */ 856 857 dprintf("found txh type %x beginblk=%llx endblk=%llx\n", 858 txh->txh_type, beginblk, endblk); 859 860 switch (txh->txh_type) { 861 case THT_WRITE: 862 if (blkid >= beginblk && blkid <= endblk) 863 match_offset = TRUE; 864 /* 865 * We will let this hold work for the bonus 866 * or spill buffer so that we don't need to 867 * hold it when creating a new object. 868 */ 869 if (blkid == DMU_BONUS_BLKID || 870 blkid == DMU_SPILL_BLKID) 871 match_offset = TRUE; 872 /* 873 * They might have to increase nlevels, 874 * thus dirtying the new TLIBs. Or the 875 * might have to change the block size, 876 * thus dirying the new lvl=0 blk=0. 877 */ 878 if (blkid == 0) 879 match_offset = TRUE; 880 break; 881 case THT_FREE: 882 /* 883 * We will dirty all the level 1 blocks in 884 * the free range and perhaps the first and 885 * last level 0 block. 886 */ 887 if (blkid >= beginblk && (blkid <= endblk || 888 txh->txh_arg2 == DMU_OBJECT_END)) 889 match_offset = TRUE; 890 break; 891 case THT_SPILL: 892 if (blkid == DMU_SPILL_BLKID) 893 match_offset = TRUE; 894 break; 895 case THT_BONUS: 896 if (blkid == DMU_BONUS_BLKID) 897 match_offset = TRUE; 898 break; 899 case THT_ZAP: 900 match_offset = TRUE; 901 break; 902 case THT_NEWOBJECT: 903 match_object = TRUE; 904 break; 905 default: 906 ASSERT(!"bad txh_type"); 907 } 908 } 909 if (match_object && match_offset) { 910 DB_DNODE_EXIT(db); 911 return; 912 } 913 } 914 DB_DNODE_EXIT(db); 915 panic("dirtying dbuf obj=%llx lvl=%u blkid=%llx but not tx_held\n", 916 (u_longlong_t)db->db.db_object, db->db_level, 917 (u_longlong_t)db->db_blkid); 918 } 919 #endif 920 921 /* 922 * If we can't do 10 iops, something is wrong. Let us go ahead 923 * and hit zfs_dirty_data_max. 924 */ 925 hrtime_t zfs_delay_max_ns = MSEC2NSEC(100); 926 int zfs_delay_resolution_ns = 100 * 1000; /* 100 microseconds */ 927 928 /* 929 * We delay transactions when we've determined that the backend storage 930 * isn't able to accommodate the rate of incoming writes. 931 * 932 * If there is already a transaction waiting, we delay relative to when 933 * that transaction finishes waiting. This way the calculated min_time 934 * is independent of the number of threads concurrently executing 935 * transactions. 936 * 937 * If we are the only waiter, wait relative to when the transaction 938 * started, rather than the current time. This credits the transaction for 939 * "time already served", e.g. reading indirect blocks. 940 * 941 * The minimum time for a transaction to take is calculated as: 942 * min_time = scale * (dirty - min) / (max - dirty) 943 * min_time is then capped at zfs_delay_max_ns. 944 * 945 * The delay has two degrees of freedom that can be adjusted via tunables. 946 * The percentage of dirty data at which we start to delay is defined by 947 * zfs_delay_min_dirty_percent. This should typically be at or above 948 * zfs_vdev_async_write_active_max_dirty_percent so that we only start to 949 * delay after writing at full speed has failed to keep up with the incoming 950 * write rate. The scale of the curve is defined by zfs_delay_scale. Roughly 951 * speaking, this variable determines the amount of delay at the midpoint of 952 * the curve. 953 * 954 * delay 955 * 10ms +-------------------------------------------------------------*+ 956 * | *| 957 * 9ms + *+ 958 * | *| 959 * 8ms + *+ 960 * | * | 961 * 7ms + * + 962 * | * | 963 * 6ms + * + 964 * | * | 965 * 5ms + * + 966 * | * | 967 * 4ms + * + 968 * | * | 969 * 3ms + * + 970 * | * | 971 * 2ms + (midpoint) * + 972 * | | ** | 973 * 1ms + v *** + 974 * | zfs_delay_scale ----------> ******** | 975 * 0 +-------------------------------------*********----------------+ 976 * 0% <- zfs_dirty_data_max -> 100% 977 * 978 * Note that since the delay is added to the outstanding time remaining on the 979 * most recent transaction, the delay is effectively the inverse of IOPS. 980 * Here the midpoint of 500us translates to 2000 IOPS. The shape of the curve 981 * was chosen such that small changes in the amount of accumulated dirty data 982 * in the first 3/4 of the curve yield relatively small differences in the 983 * amount of delay. 984 * 985 * The effects can be easier to understand when the amount of delay is 986 * represented on a log scale: 987 * 988 * delay 989 * 100ms +-------------------------------------------------------------++ 990 * + + 991 * | | 992 * + *+ 993 * 10ms + *+ 994 * + ** + 995 * | (midpoint) ** | 996 * + | ** + 997 * 1ms + v **** + 998 * + zfs_delay_scale ----------> ***** + 999 * | **** | 1000 * + **** + 1001 * 100us + ** + 1002 * + * + 1003 * | * | 1004 * + * + 1005 * 10us + * + 1006 * + + 1007 * | | 1008 * + + 1009 * +--------------------------------------------------------------+ 1010 * 0% <- zfs_dirty_data_max -> 100% 1011 * 1012 * Note here that only as the amount of dirty data approaches its limit does 1013 * the delay start to increase rapidly. The goal of a properly tuned system 1014 * should be to keep the amount of dirty data out of that range by first 1015 * ensuring that the appropriate limits are set for the I/O scheduler to reach 1016 * optimal throughput on the backend storage, and then by changing the value 1017 * of zfs_delay_scale to increase the steepness of the curve. 1018 */ 1019 static void 1020 dmu_tx_delay(dmu_tx_t *tx, uint64_t dirty) 1021 { 1022 dsl_pool_t *dp = tx->tx_pool; 1023 uint64_t delay_min_bytes = 1024 zfs_dirty_data_max * zfs_delay_min_dirty_percent / 100; 1025 hrtime_t wakeup, min_tx_time, now; 1026 1027 if (dirty <= delay_min_bytes) 1028 return; 1029 1030 /* 1031 * The caller has already waited until we are under the max. 1032 * We make them pass us the amount of dirty data so we don't 1033 * have to handle the case of it being >= the max, which could 1034 * cause a divide-by-zero if it's == the max. 1035 */ 1036 ASSERT3U(dirty, <, zfs_dirty_data_max); 1037 1038 now = gethrtime(); 1039 min_tx_time = zfs_delay_scale * 1040 (dirty - delay_min_bytes) / (zfs_dirty_data_max - dirty); 1041 if (now > tx->tx_start + min_tx_time) 1042 return; 1043 1044 min_tx_time = MIN(min_tx_time, zfs_delay_max_ns); 1045 1046 DTRACE_PROBE3(delay__mintime, dmu_tx_t *, tx, uint64_t, dirty, 1047 uint64_t, min_tx_time); 1048 1049 mutex_enter(&dp->dp_lock); 1050 wakeup = MAX(tx->tx_start + min_tx_time, 1051 dp->dp_last_wakeup + min_tx_time); 1052 dp->dp_last_wakeup = wakeup; 1053 mutex_exit(&dp->dp_lock); 1054 1055 #ifdef _KERNEL 1056 mutex_enter(&curthread->t_delay_lock); 1057 while (cv_timedwait_hires(&curthread->t_delay_cv, 1058 &curthread->t_delay_lock, wakeup, zfs_delay_resolution_ns, 1059 CALLOUT_FLAG_ABSOLUTE | CALLOUT_FLAG_ROUNDUP) > 0) 1060 continue; 1061 mutex_exit(&curthread->t_delay_lock); 1062 #else 1063 hrtime_t delta = wakeup - gethrtime(); 1064 struct timespec ts; 1065 ts.tv_sec = delta / NANOSEC; 1066 ts.tv_nsec = delta % NANOSEC; 1067 (void) nanosleep(&ts, NULL); 1068 #endif 1069 } 1070 1071 static int 1072 dmu_tx_try_assign(dmu_tx_t *tx, txg_how_t txg_how) 1073 { 1074 dmu_tx_hold_t *txh; 1075 spa_t *spa = tx->tx_pool->dp_spa; 1076 uint64_t memory, asize, fsize, usize; 1077 uint64_t towrite, tofree, tooverwrite, tounref, tohold, fudge; 1078 1079 ASSERT0(tx->tx_txg); 1080 1081 if (tx->tx_err) 1082 return (tx->tx_err); 1083 1084 if (spa_suspended(spa)) { 1085 /* 1086 * If the user has indicated a blocking failure mode 1087 * then return ERESTART which will block in dmu_tx_wait(). 1088 * Otherwise, return EIO so that an error can get 1089 * propagated back to the VOP calls. 1090 * 1091 * Note that we always honor the txg_how flag regardless 1092 * of the failuremode setting. 1093 */ 1094 if (spa_get_failmode(spa) == ZIO_FAILURE_MODE_CONTINUE && 1095 txg_how != TXG_WAIT) 1096 return (SET_ERROR(EIO)); 1097 1098 return (SET_ERROR(ERESTART)); 1099 } 1100 1101 if (!tx->tx_waited && 1102 dsl_pool_need_dirty_delay(tx->tx_pool)) { 1103 tx->tx_wait_dirty = B_TRUE; 1104 return (SET_ERROR(ERESTART)); 1105 } 1106 1107 tx->tx_txg = txg_hold_open(tx->tx_pool, &tx->tx_txgh); 1108 tx->tx_needassign_txh = NULL; 1109 1110 /* 1111 * NB: No error returns are allowed after txg_hold_open, but 1112 * before processing the dnode holds, due to the 1113 * dmu_tx_unassign() logic. 1114 */ 1115 1116 towrite = tofree = tooverwrite = tounref = tohold = fudge = 0; 1117 for (txh = list_head(&tx->tx_holds); txh; 1118 txh = list_next(&tx->tx_holds, txh)) { 1119 dnode_t *dn = txh->txh_dnode; 1120 if (dn != NULL) { 1121 mutex_enter(&dn->dn_mtx); 1122 if (dn->dn_assigned_txg == tx->tx_txg - 1) { 1123 mutex_exit(&dn->dn_mtx); 1124 tx->tx_needassign_txh = txh; 1125 return (SET_ERROR(ERESTART)); 1126 } 1127 if (dn->dn_assigned_txg == 0) 1128 dn->dn_assigned_txg = tx->tx_txg; 1129 ASSERT3U(dn->dn_assigned_txg, ==, tx->tx_txg); 1130 (void) refcount_add(&dn->dn_tx_holds, tx); 1131 mutex_exit(&dn->dn_mtx); 1132 } 1133 towrite += txh->txh_space_towrite; 1134 tofree += txh->txh_space_tofree; 1135 tooverwrite += txh->txh_space_tooverwrite; 1136 tounref += txh->txh_space_tounref; 1137 tohold += txh->txh_memory_tohold; 1138 fudge += txh->txh_fudge; 1139 } 1140 1141 /* 1142 * If a snapshot has been taken since we made our estimates, 1143 * assume that we won't be able to free or overwrite anything. 1144 */ 1145 if (tx->tx_objset && 1146 dsl_dataset_prev_snap_txg(tx->tx_objset->os_dsl_dataset) > 1147 tx->tx_lastsnap_txg) { 1148 towrite += tooverwrite; 1149 tooverwrite = tofree = 0; 1150 } 1151 1152 /* needed allocation: worst-case estimate of write space */ 1153 asize = spa_get_asize(tx->tx_pool->dp_spa, towrite + tooverwrite); 1154 /* freed space estimate: worst-case overwrite + free estimate */ 1155 fsize = spa_get_asize(tx->tx_pool->dp_spa, tooverwrite) + tofree; 1156 /* convert unrefd space to worst-case estimate */ 1157 usize = spa_get_asize(tx->tx_pool->dp_spa, tounref); 1158 /* calculate memory footprint estimate */ 1159 memory = towrite + tooverwrite + tohold; 1160 1161 #ifdef ZFS_DEBUG 1162 /* 1163 * Add in 'tohold' to account for our dirty holds on this memory 1164 * XXX - the "fudge" factor is to account for skipped blocks that 1165 * we missed because dnode_next_offset() misses in-core-only blocks. 1166 */ 1167 tx->tx_space_towrite = asize + 1168 spa_get_asize(tx->tx_pool->dp_spa, tohold + fudge); 1169 tx->tx_space_tofree = tofree; 1170 tx->tx_space_tooverwrite = tooverwrite; 1171 tx->tx_space_tounref = tounref; 1172 #endif 1173 1174 if (tx->tx_dir && asize != 0) { 1175 int err = dsl_dir_tempreserve_space(tx->tx_dir, memory, 1176 asize, fsize, usize, &tx->tx_tempreserve_cookie, tx); 1177 if (err) 1178 return (err); 1179 } 1180 1181 return (0); 1182 } 1183 1184 static void 1185 dmu_tx_unassign(dmu_tx_t *tx) 1186 { 1187 dmu_tx_hold_t *txh; 1188 1189 if (tx->tx_txg == 0) 1190 return; 1191 1192 txg_rele_to_quiesce(&tx->tx_txgh); 1193 1194 /* 1195 * Walk the transaction's hold list, removing the hold on the 1196 * associated dnode, and notifying waiters if the refcount drops to 0. 1197 */ 1198 for (txh = list_head(&tx->tx_holds); txh != tx->tx_needassign_txh; 1199 txh = list_next(&tx->tx_holds, txh)) { 1200 dnode_t *dn = txh->txh_dnode; 1201 1202 if (dn == NULL) 1203 continue; 1204 mutex_enter(&dn->dn_mtx); 1205 ASSERT3U(dn->dn_assigned_txg, ==, tx->tx_txg); 1206 1207 if (refcount_remove(&dn->dn_tx_holds, tx) == 0) { 1208 dn->dn_assigned_txg = 0; 1209 cv_broadcast(&dn->dn_notxholds); 1210 } 1211 mutex_exit(&dn->dn_mtx); 1212 } 1213 1214 txg_rele_to_sync(&tx->tx_txgh); 1215 1216 tx->tx_lasttried_txg = tx->tx_txg; 1217 tx->tx_txg = 0; 1218 } 1219 1220 /* 1221 * Assign tx to a transaction group. txg_how can be one of: 1222 * 1223 * (1) TXG_WAIT. If the current open txg is full, waits until there's 1224 * a new one. This should be used when you're not holding locks. 1225 * It will only fail if we're truly out of space (or over quota). 1226 * 1227 * (2) TXG_NOWAIT. If we can't assign into the current open txg without 1228 * blocking, returns immediately with ERESTART. This should be used 1229 * whenever you're holding locks. On an ERESTART error, the caller 1230 * should drop locks, do a dmu_tx_wait(tx), and try again. 1231 * 1232 * (3) TXG_WAITED. Like TXG_NOWAIT, but indicates that dmu_tx_wait() 1233 * has already been called on behalf of this operation (though 1234 * most likely on a different tx). 1235 */ 1236 int 1237 dmu_tx_assign(dmu_tx_t *tx, txg_how_t txg_how) 1238 { 1239 int err; 1240 1241 ASSERT(tx->tx_txg == 0); 1242 ASSERT(txg_how == TXG_WAIT || txg_how == TXG_NOWAIT || 1243 txg_how == TXG_WAITED); 1244 ASSERT(!dsl_pool_sync_context(tx->tx_pool)); 1245 1246 /* If we might wait, we must not hold the config lock. */ 1247 ASSERT(txg_how != TXG_WAIT || !dsl_pool_config_held(tx->tx_pool)); 1248 1249 if (txg_how == TXG_WAITED) 1250 tx->tx_waited = B_TRUE; 1251 1252 while ((err = dmu_tx_try_assign(tx, txg_how)) != 0) { 1253 dmu_tx_unassign(tx); 1254 1255 if (err != ERESTART || txg_how != TXG_WAIT) 1256 return (err); 1257 1258 dmu_tx_wait(tx); 1259 } 1260 1261 txg_rele_to_quiesce(&tx->tx_txgh); 1262 1263 return (0); 1264 } 1265 1266 void 1267 dmu_tx_wait(dmu_tx_t *tx) 1268 { 1269 spa_t *spa = tx->tx_pool->dp_spa; 1270 dsl_pool_t *dp = tx->tx_pool; 1271 1272 ASSERT(tx->tx_txg == 0); 1273 ASSERT(!dsl_pool_config_held(tx->tx_pool)); 1274 1275 if (tx->tx_wait_dirty) { 1276 /* 1277 * dmu_tx_try_assign() has determined that we need to wait 1278 * because we've consumed much or all of the dirty buffer 1279 * space. 1280 */ 1281 mutex_enter(&dp->dp_lock); 1282 while (dp->dp_dirty_total >= zfs_dirty_data_max) 1283 cv_wait(&dp->dp_spaceavail_cv, &dp->dp_lock); 1284 uint64_t dirty = dp->dp_dirty_total; 1285 mutex_exit(&dp->dp_lock); 1286 1287 dmu_tx_delay(tx, dirty); 1288 1289 tx->tx_wait_dirty = B_FALSE; 1290 1291 /* 1292 * Note: setting tx_waited only has effect if the caller 1293 * used TX_WAIT. Otherwise they are going to destroy 1294 * this tx and try again. The common case, zfs_write(), 1295 * uses TX_WAIT. 1296 */ 1297 tx->tx_waited = B_TRUE; 1298 } else if (spa_suspended(spa) || tx->tx_lasttried_txg == 0) { 1299 /* 1300 * If the pool is suspended we need to wait until it 1301 * is resumed. Note that it's possible that the pool 1302 * has become active after this thread has tried to 1303 * obtain a tx. If that's the case then tx_lasttried_txg 1304 * would not have been set. 1305 */ 1306 txg_wait_synced(dp, spa_last_synced_txg(spa) + 1); 1307 } else if (tx->tx_needassign_txh) { 1308 /* 1309 * A dnode is assigned to the quiescing txg. Wait for its 1310 * transaction to complete. 1311 */ 1312 dnode_t *dn = tx->tx_needassign_txh->txh_dnode; 1313 1314 mutex_enter(&dn->dn_mtx); 1315 while (dn->dn_assigned_txg == tx->tx_lasttried_txg - 1) 1316 cv_wait(&dn->dn_notxholds, &dn->dn_mtx); 1317 mutex_exit(&dn->dn_mtx); 1318 tx->tx_needassign_txh = NULL; 1319 } else { 1320 txg_wait_open(tx->tx_pool, tx->tx_lasttried_txg + 1); 1321 } 1322 } 1323 1324 void 1325 dmu_tx_willuse_space(dmu_tx_t *tx, int64_t delta) 1326 { 1327 #ifdef ZFS_DEBUG 1328 if (tx->tx_dir == NULL || delta == 0) 1329 return; 1330 1331 if (delta > 0) { 1332 ASSERT3U(refcount_count(&tx->tx_space_written) + delta, <=, 1333 tx->tx_space_towrite); 1334 (void) refcount_add_many(&tx->tx_space_written, delta, NULL); 1335 } else { 1336 (void) refcount_add_many(&tx->tx_space_freed, -delta, NULL); 1337 } 1338 #endif 1339 } 1340 1341 void 1342 dmu_tx_commit(dmu_tx_t *tx) 1343 { 1344 dmu_tx_hold_t *txh; 1345 1346 ASSERT(tx->tx_txg != 0); 1347 1348 /* 1349 * Go through the transaction's hold list and remove holds on 1350 * associated dnodes, notifying waiters if no holds remain. 1351 */ 1352 while (txh = list_head(&tx->tx_holds)) { 1353 dnode_t *dn = txh->txh_dnode; 1354 1355 list_remove(&tx->tx_holds, txh); 1356 kmem_free(txh, sizeof (dmu_tx_hold_t)); 1357 if (dn == NULL) 1358 continue; 1359 mutex_enter(&dn->dn_mtx); 1360 ASSERT3U(dn->dn_assigned_txg, ==, tx->tx_txg); 1361 1362 if (refcount_remove(&dn->dn_tx_holds, tx) == 0) { 1363 dn->dn_assigned_txg = 0; 1364 cv_broadcast(&dn->dn_notxholds); 1365 } 1366 mutex_exit(&dn->dn_mtx); 1367 dnode_rele(dn, tx); 1368 } 1369 1370 if (tx->tx_tempreserve_cookie) 1371 dsl_dir_tempreserve_clear(tx->tx_tempreserve_cookie, tx); 1372 1373 if (!list_is_empty(&tx->tx_callbacks)) 1374 txg_register_callbacks(&tx->tx_txgh, &tx->tx_callbacks); 1375 1376 if (tx->tx_anyobj == FALSE) 1377 txg_rele_to_sync(&tx->tx_txgh); 1378 1379 list_destroy(&tx->tx_callbacks); 1380 list_destroy(&tx->tx_holds); 1381 #ifdef ZFS_DEBUG 1382 dprintf("towrite=%llu written=%llu tofree=%llu freed=%llu\n", 1383 tx->tx_space_towrite, refcount_count(&tx->tx_space_written), 1384 tx->tx_space_tofree, refcount_count(&tx->tx_space_freed)); 1385 refcount_destroy_many(&tx->tx_space_written, 1386 refcount_count(&tx->tx_space_written)); 1387 refcount_destroy_many(&tx->tx_space_freed, 1388 refcount_count(&tx->tx_space_freed)); 1389 #endif 1390 kmem_free(tx, sizeof (dmu_tx_t)); 1391 } 1392 1393 void 1394 dmu_tx_abort(dmu_tx_t *tx) 1395 { 1396 dmu_tx_hold_t *txh; 1397 1398 ASSERT(tx->tx_txg == 0); 1399 1400 while (txh = list_head(&tx->tx_holds)) { 1401 dnode_t *dn = txh->txh_dnode; 1402 1403 list_remove(&tx->tx_holds, txh); 1404 kmem_free(txh, sizeof (dmu_tx_hold_t)); 1405 if (dn != NULL) 1406 dnode_rele(dn, tx); 1407 } 1408 1409 /* 1410 * Call any registered callbacks with an error code. 1411 */ 1412 if (!list_is_empty(&tx->tx_callbacks)) 1413 dmu_tx_do_callbacks(&tx->tx_callbacks, ECANCELED); 1414 1415 list_destroy(&tx->tx_callbacks); 1416 list_destroy(&tx->tx_holds); 1417 #ifdef ZFS_DEBUG 1418 refcount_destroy_many(&tx->tx_space_written, 1419 refcount_count(&tx->tx_space_written)); 1420 refcount_destroy_many(&tx->tx_space_freed, 1421 refcount_count(&tx->tx_space_freed)); 1422 #endif 1423 kmem_free(tx, sizeof (dmu_tx_t)); 1424 } 1425 1426 uint64_t 1427 dmu_tx_get_txg(dmu_tx_t *tx) 1428 { 1429 ASSERT(tx->tx_txg != 0); 1430 return (tx->tx_txg); 1431 } 1432 1433 dsl_pool_t * 1434 dmu_tx_pool(dmu_tx_t *tx) 1435 { 1436 ASSERT(tx->tx_pool != NULL); 1437 return (tx->tx_pool); 1438 } 1439 1440 1441 void 1442 dmu_tx_callback_register(dmu_tx_t *tx, dmu_tx_callback_func_t *func, void *data) 1443 { 1444 dmu_tx_callback_t *dcb; 1445 1446 dcb = kmem_alloc(sizeof (dmu_tx_callback_t), KM_SLEEP); 1447 1448 dcb->dcb_func = func; 1449 dcb->dcb_data = data; 1450 1451 list_insert_tail(&tx->tx_callbacks, dcb); 1452 } 1453 1454 /* 1455 * Call all the commit callbacks on a list, with a given error code. 1456 */ 1457 void 1458 dmu_tx_do_callbacks(list_t *cb_list, int error) 1459 { 1460 dmu_tx_callback_t *dcb; 1461 1462 while (dcb = list_head(cb_list)) { 1463 list_remove(cb_list, dcb); 1464 dcb->dcb_func(dcb->dcb_data, error); 1465 kmem_free(dcb, sizeof (dmu_tx_callback_t)); 1466 } 1467 } 1468 1469 /* 1470 * Interface to hold a bunch of attributes. 1471 * used for creating new files. 1472 * attrsize is the total size of all attributes 1473 * to be added during object creation 1474 * 1475 * For updating/adding a single attribute dmu_tx_hold_sa() should be used. 1476 */ 1477 1478 /* 1479 * hold necessary attribute name for attribute registration. 1480 * should be a very rare case where this is needed. If it does 1481 * happen it would only happen on the first write to the file system. 1482 */ 1483 static void 1484 dmu_tx_sa_registration_hold(sa_os_t *sa, dmu_tx_t *tx) 1485 { 1486 int i; 1487 1488 if (!sa->sa_need_attr_registration) 1489 return; 1490 1491 for (i = 0; i != sa->sa_num_attrs; i++) { 1492 if (!sa->sa_attr_table[i].sa_registered) { 1493 if (sa->sa_reg_attr_obj) 1494 dmu_tx_hold_zap(tx, sa->sa_reg_attr_obj, 1495 B_TRUE, sa->sa_attr_table[i].sa_name); 1496 else 1497 dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, 1498 B_TRUE, sa->sa_attr_table[i].sa_name); 1499 } 1500 } 1501 } 1502 1503 1504 void 1505 dmu_tx_hold_spill(dmu_tx_t *tx, uint64_t object) 1506 { 1507 dnode_t *dn; 1508 dmu_tx_hold_t *txh; 1509 1510 txh = dmu_tx_hold_object_impl(tx, tx->tx_objset, object, 1511 THT_SPILL, 0, 0); 1512 1513 dn = txh->txh_dnode; 1514 1515 if (dn == NULL) 1516 return; 1517 1518 /* If blkptr doesn't exist then add space to towrite */ 1519 if (!(dn->dn_phys->dn_flags & DNODE_FLAG_SPILL_BLKPTR)) { 1520 txh->txh_space_towrite += SPA_MAXBLOCKSIZE; 1521 } else { 1522 blkptr_t *bp; 1523 1524 bp = &dn->dn_phys->dn_spill; 1525 if (dsl_dataset_block_freeable(dn->dn_objset->os_dsl_dataset, 1526 bp, bp->blk_birth)) 1527 txh->txh_space_tooverwrite += SPA_MAXBLOCKSIZE; 1528 else 1529 txh->txh_space_towrite += SPA_MAXBLOCKSIZE; 1530 if (!BP_IS_HOLE(bp)) 1531 txh->txh_space_tounref += SPA_MAXBLOCKSIZE; 1532 } 1533 } 1534 1535 void 1536 dmu_tx_hold_sa_create(dmu_tx_t *tx, int attrsize) 1537 { 1538 sa_os_t *sa = tx->tx_objset->os_sa; 1539 1540 dmu_tx_hold_bonus(tx, DMU_NEW_OBJECT); 1541 1542 if (tx->tx_objset->os_sa->sa_master_obj == 0) 1543 return; 1544 1545 if (tx->tx_objset->os_sa->sa_layout_attr_obj) 1546 dmu_tx_hold_zap(tx, sa->sa_layout_attr_obj, B_TRUE, NULL); 1547 else { 1548 dmu_tx_hold_zap(tx, sa->sa_master_obj, B_TRUE, SA_LAYOUTS); 1549 dmu_tx_hold_zap(tx, sa->sa_master_obj, B_TRUE, SA_REGISTRY); 1550 dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, B_TRUE, NULL); 1551 dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, B_TRUE, NULL); 1552 } 1553 1554 dmu_tx_sa_registration_hold(sa, tx); 1555 1556 if (attrsize <= DN_MAX_BONUSLEN && !sa->sa_force_spill) 1557 return; 1558 1559 (void) dmu_tx_hold_object_impl(tx, tx->tx_objset, DMU_NEW_OBJECT, 1560 THT_SPILL, 0, 0); 1561 } 1562 1563 /* 1564 * Hold SA attribute 1565 * 1566 * dmu_tx_hold_sa(dmu_tx_t *tx, sa_handle_t *, attribute, add, size) 1567 * 1568 * variable_size is the total size of all variable sized attributes 1569 * passed to this function. It is not the total size of all 1570 * variable size attributes that *may* exist on this object. 1571 */ 1572 void 1573 dmu_tx_hold_sa(dmu_tx_t *tx, sa_handle_t *hdl, boolean_t may_grow) 1574 { 1575 uint64_t object; 1576 sa_os_t *sa = tx->tx_objset->os_sa; 1577 1578 ASSERT(hdl != NULL); 1579 1580 object = sa_handle_object(hdl); 1581 1582 dmu_tx_hold_bonus(tx, object); 1583 1584 if (tx->tx_objset->os_sa->sa_master_obj == 0) 1585 return; 1586 1587 if (tx->tx_objset->os_sa->sa_reg_attr_obj == 0 || 1588 tx->tx_objset->os_sa->sa_layout_attr_obj == 0) { 1589 dmu_tx_hold_zap(tx, sa->sa_master_obj, B_TRUE, SA_LAYOUTS); 1590 dmu_tx_hold_zap(tx, sa->sa_master_obj, B_TRUE, SA_REGISTRY); 1591 dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, B_TRUE, NULL); 1592 dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, B_TRUE, NULL); 1593 } 1594 1595 dmu_tx_sa_registration_hold(sa, tx); 1596 1597 if (may_grow && tx->tx_objset->os_sa->sa_layout_attr_obj) 1598 dmu_tx_hold_zap(tx, sa->sa_layout_attr_obj, B_TRUE, NULL); 1599 1600 if (sa->sa_force_spill || may_grow || hdl->sa_spill) { 1601 ASSERT(tx->tx_txg == 0); 1602 dmu_tx_hold_spill(tx, object); 1603 } else { 1604 dmu_buf_impl_t *db = (dmu_buf_impl_t *)hdl->sa_bonus; 1605 dnode_t *dn; 1606 1607 DB_DNODE_ENTER(db); 1608 dn = DB_DNODE(db); 1609 if (dn->dn_have_spill) { 1610 ASSERT(tx->tx_txg == 0); 1611 dmu_tx_hold_spill(tx, object); 1612 } 1613 DB_DNODE_EXIT(db); 1614 } 1615 } 1616