/* * CDDL HEADER START * * The contents of this file are subject to the terms of the * Common Development and Distribution License (the "License"). * You may not use this file except in compliance with the License. * * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE * or http://www.opensolaris.org/os/licensing. * See the License for the specific language governing permissions * and limitations under the License. * * When distributing Covered Code, include this CDDL HEADER in each * file and include the License file at usr/src/OPENSOLARIS.LICENSE. * If applicable, add the following below this CDDL HEADER, with the * fields enclosed by brackets "[]" replaced with your own identifying * information: Portions Copyright [yyyy] [name of copyright owner] * * CDDL HEADER END */ /* * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. * Copyright 2011 Nexenta Systems, Inc. All rights reserved. * Copyright (c) 2012, 2014 by Delphix. All rights reserved. */ #include #include #include #include #include #include /* for dsl_dataset_block_freeable() */ #include /* for dsl_dir_tempreserve_*() */ #include #include /* for fzap_default_block_shift */ #include #include #include #include #include typedef void (*dmu_tx_hold_func_t)(dmu_tx_t *tx, struct dnode *dn, uint64_t arg1, uint64_t arg2); dmu_tx_t * dmu_tx_create_dd(dsl_dir_t *dd) { dmu_tx_t *tx = kmem_zalloc(sizeof (dmu_tx_t), KM_SLEEP); tx->tx_dir = dd; if (dd != NULL) tx->tx_pool = dd->dd_pool; list_create(&tx->tx_holds, sizeof (dmu_tx_hold_t), offsetof(dmu_tx_hold_t, txh_node)); list_create(&tx->tx_callbacks, sizeof (dmu_tx_callback_t), offsetof(dmu_tx_callback_t, dcb_node)); tx->tx_start = gethrtime(); #ifdef ZFS_DEBUG refcount_create(&tx->tx_space_written); refcount_create(&tx->tx_space_freed); #endif return (tx); } dmu_tx_t * dmu_tx_create(objset_t *os) { dmu_tx_t *tx = dmu_tx_create_dd(os->os_dsl_dataset->ds_dir); tx->tx_objset = os; tx->tx_lastsnap_txg = dsl_dataset_prev_snap_txg(os->os_dsl_dataset); return (tx); } dmu_tx_t * dmu_tx_create_assigned(struct dsl_pool *dp, uint64_t txg) { dmu_tx_t *tx = dmu_tx_create_dd(NULL); ASSERT3U(txg, <=, dp->dp_tx.tx_open_txg); tx->tx_pool = dp; tx->tx_txg = txg; tx->tx_anyobj = TRUE; return (tx); } int dmu_tx_is_syncing(dmu_tx_t *tx) { return (tx->tx_anyobj); } int dmu_tx_private_ok(dmu_tx_t *tx) { return (tx->tx_anyobj); } static dmu_tx_hold_t * dmu_tx_hold_object_impl(dmu_tx_t *tx, objset_t *os, uint64_t object, enum dmu_tx_hold_type type, uint64_t arg1, uint64_t arg2) { dmu_tx_hold_t *txh; dnode_t *dn = NULL; int err; if (object != DMU_NEW_OBJECT) { err = dnode_hold(os, object, tx, &dn); if (err) { tx->tx_err = err; return (NULL); } if (err == 0 && tx->tx_txg != 0) { mutex_enter(&dn->dn_mtx); /* * dn->dn_assigned_txg == tx->tx_txg doesn't pose a * problem, but there's no way for it to happen (for * now, at least). */ ASSERT(dn->dn_assigned_txg == 0); dn->dn_assigned_txg = tx->tx_txg; (void) refcount_add(&dn->dn_tx_holds, tx); mutex_exit(&dn->dn_mtx); } } txh = kmem_zalloc(sizeof (dmu_tx_hold_t), KM_SLEEP); txh->txh_tx = tx; txh->txh_dnode = dn; #ifdef ZFS_DEBUG txh->txh_type = type; txh->txh_arg1 = arg1; txh->txh_arg2 = arg2; #endif list_insert_tail(&tx->tx_holds, txh); return (txh); } void dmu_tx_add_new_object(dmu_tx_t *tx, objset_t *os, uint64_t object) { /* * If we're syncing, they can manipulate any object anyhow, and * the hold on the dnode_t can cause problems. */ if (!dmu_tx_is_syncing(tx)) { (void) dmu_tx_hold_object_impl(tx, os, object, THT_NEWOBJECT, 0, 0); } } static int dmu_tx_check_ioerr(zio_t *zio, dnode_t *dn, int level, uint64_t blkid) { int err; dmu_buf_impl_t *db; rw_enter(&dn->dn_struct_rwlock, RW_READER); db = dbuf_hold_level(dn, level, blkid, FTAG); rw_exit(&dn->dn_struct_rwlock); if (db == NULL) return (SET_ERROR(EIO)); err = dbuf_read(db, zio, DB_RF_CANFAIL | DB_RF_NOPREFETCH); dbuf_rele(db, FTAG); return (err); } static void dmu_tx_count_twig(dmu_tx_hold_t *txh, dnode_t *dn, dmu_buf_impl_t *db, int level, uint64_t blkid, boolean_t freeable, uint64_t *history) { objset_t *os = dn->dn_objset; dsl_dataset_t *ds = os->os_dsl_dataset; int epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT; dmu_buf_impl_t *parent = NULL; blkptr_t *bp = NULL; uint64_t space; if (level >= dn->dn_nlevels || history[level] == blkid) return; history[level] = blkid; space = (level == 0) ? dn->dn_datablksz : (1ULL << dn->dn_indblkshift); if (db == NULL || db == dn->dn_dbuf) { ASSERT(level != 0); db = NULL; } else { ASSERT(DB_DNODE(db) == dn); ASSERT(db->db_level == level); ASSERT(db->db.db_size == space); ASSERT(db->db_blkid == blkid); bp = db->db_blkptr; parent = db->db_parent; } freeable = (bp && (freeable || dsl_dataset_block_freeable(ds, bp, bp->blk_birth))); if (freeable) txh->txh_space_tooverwrite += space; else txh->txh_space_towrite += space; if (bp) txh->txh_space_tounref += bp_get_dsize(os->os_spa, bp); dmu_tx_count_twig(txh, dn, parent, level + 1, blkid >> epbs, freeable, history); } /* ARGSUSED */ static void dmu_tx_count_write(dmu_tx_hold_t *txh, uint64_t off, uint64_t len) { dnode_t *dn = txh->txh_dnode; uint64_t start, end, i; int min_bs, max_bs, min_ibs, max_ibs, epbs, bits; int err = 0; if (len == 0) return; min_bs = SPA_MINBLOCKSHIFT; max_bs = SPA_MAXBLOCKSHIFT; min_ibs = DN_MIN_INDBLKSHIFT; max_ibs = DN_MAX_INDBLKSHIFT; if (dn) { uint64_t history[DN_MAX_LEVELS]; int nlvls = dn->dn_nlevels; int delta; /* * For i/o error checking, read the first and last level-0 * blocks (if they are not aligned), and all the level-1 blocks. */ if (dn->dn_maxblkid == 0) { delta = dn->dn_datablksz; start = (off < dn->dn_datablksz) ? 0 : 1; end = (off+len <= dn->dn_datablksz) ? 0 : 1; if (start == 0 && (off > 0 || len < dn->dn_datablksz)) { err = dmu_tx_check_ioerr(NULL, dn, 0, 0); if (err) goto out; delta -= off; } } else { zio_t *zio = zio_root(dn->dn_objset->os_spa, NULL, NULL, ZIO_FLAG_CANFAIL); /* first level-0 block */ start = off >> dn->dn_datablkshift; if (P2PHASE(off, dn->dn_datablksz) || len < dn->dn_datablksz) { err = dmu_tx_check_ioerr(zio, dn, 0, start); if (err) goto out; } /* last level-0 block */ end = (off+len-1) >> dn->dn_datablkshift; if (end != start && end <= dn->dn_maxblkid && P2PHASE(off+len, dn->dn_datablksz)) { err = dmu_tx_check_ioerr(zio, dn, 0, end); if (err) goto out; } /* level-1 blocks */ if (nlvls > 1) { int shft = dn->dn_indblkshift - SPA_BLKPTRSHIFT; for (i = (start>>shft)+1; i < end>>shft; i++) { err = dmu_tx_check_ioerr(zio, dn, 1, i); if (err) goto out; } } err = zio_wait(zio); if (err) goto out; delta = P2NPHASE(off, dn->dn_datablksz); } min_ibs = max_ibs = dn->dn_indblkshift; if (dn->dn_maxblkid > 0) { /* * The blocksize can't change, * so we can make a more precise estimate. */ ASSERT(dn->dn_datablkshift != 0); min_bs = max_bs = dn->dn_datablkshift; } /* * If this write is not off the end of the file * we need to account for overwrites/unref. */ if (start <= dn->dn_maxblkid) { for (int l = 0; l < DN_MAX_LEVELS; l++) history[l] = -1ULL; } while (start <= dn->dn_maxblkid) { dmu_buf_impl_t *db; rw_enter(&dn->dn_struct_rwlock, RW_READER); err = dbuf_hold_impl(dn, 0, start, FALSE, FTAG, &db); rw_exit(&dn->dn_struct_rwlock); if (err) { txh->txh_tx->tx_err = err; return; } dmu_tx_count_twig(txh, dn, db, 0, start, B_FALSE, history); dbuf_rele(db, FTAG); if (++start > end) { /* * Account for new indirects appearing * before this IO gets assigned into a txg. */ bits = 64 - min_bs; epbs = min_ibs - SPA_BLKPTRSHIFT; for (bits -= epbs * (nlvls - 1); bits >= 0; bits -= epbs) txh->txh_fudge += 1ULL << max_ibs; goto out; } off += delta; if (len >= delta) len -= delta; delta = dn->dn_datablksz; } } /* * 'end' is the last thing we will access, not one past. * This way we won't overflow when accessing the last byte. */ start = P2ALIGN(off, 1ULL << max_bs); end = P2ROUNDUP(off + len, 1ULL << max_bs) - 1; txh->txh_space_towrite += end - start + 1; start >>= min_bs; end >>= min_bs; epbs = min_ibs - SPA_BLKPTRSHIFT; /* * The object contains at most 2^(64 - min_bs) blocks, * and each indirect level maps 2^epbs. */ for (bits = 64 - min_bs; bits >= 0; bits -= epbs) { start >>= epbs; end >>= epbs; ASSERT3U(end, >=, start); txh->txh_space_towrite += (end - start + 1) << max_ibs; if (start != 0) { /* * We also need a new blkid=0 indirect block * to reference any existing file data. */ txh->txh_space_towrite += 1ULL << max_ibs; } } out: if (txh->txh_space_towrite + txh->txh_space_tooverwrite > 2 * DMU_MAX_ACCESS) err = SET_ERROR(EFBIG); if (err) txh->txh_tx->tx_err = err; } static void dmu_tx_count_dnode(dmu_tx_hold_t *txh) { dnode_t *dn = txh->txh_dnode; dnode_t *mdn = DMU_META_DNODE(txh->txh_tx->tx_objset); uint64_t space = mdn->dn_datablksz + ((mdn->dn_nlevels-1) << mdn->dn_indblkshift); if (dn && dn->dn_dbuf->db_blkptr && dsl_dataset_block_freeable(dn->dn_objset->os_dsl_dataset, dn->dn_dbuf->db_blkptr, dn->dn_dbuf->db_blkptr->blk_birth)) { txh->txh_space_tooverwrite += space; txh->txh_space_tounref += space; } else { txh->txh_space_towrite += space; if (dn && dn->dn_dbuf->db_blkptr) txh->txh_space_tounref += space; } } void dmu_tx_hold_write(dmu_tx_t *tx, uint64_t object, uint64_t off, int len) { dmu_tx_hold_t *txh; ASSERT(tx->tx_txg == 0); ASSERT(len < DMU_MAX_ACCESS); ASSERT(len == 0 || UINT64_MAX - off >= len - 1); txh = dmu_tx_hold_object_impl(tx, tx->tx_objset, object, THT_WRITE, off, len); if (txh == NULL) return; dmu_tx_count_write(txh, off, len); dmu_tx_count_dnode(txh); } static void dmu_tx_count_free(dmu_tx_hold_t *txh, uint64_t off, uint64_t len) { uint64_t blkid, nblks, lastblk; uint64_t space = 0, unref = 0, skipped = 0; dnode_t *dn = txh->txh_dnode; dsl_dataset_t *ds = dn->dn_objset->os_dsl_dataset; spa_t *spa = txh->txh_tx->tx_pool->dp_spa; int epbs; uint64_t l0span = 0, nl1blks = 0; if (dn->dn_nlevels == 0) return; /* * The struct_rwlock protects us against dn_nlevels * changing, in case (against all odds) we manage to dirty & * sync out the changes after we check for being dirty. * Also, dbuf_hold_impl() wants us to have the struct_rwlock. */ rw_enter(&dn->dn_struct_rwlock, RW_READER); epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT; if (dn->dn_maxblkid == 0) { if (off == 0 && len >= dn->dn_datablksz) { blkid = 0; nblks = 1; } else { rw_exit(&dn->dn_struct_rwlock); return; } } else { blkid = off >> dn->dn_datablkshift; nblks = (len + dn->dn_datablksz - 1) >> dn->dn_datablkshift; if (blkid > dn->dn_maxblkid) { rw_exit(&dn->dn_struct_rwlock); return; } if (blkid + nblks > dn->dn_maxblkid) nblks = dn->dn_maxblkid - blkid + 1; } l0span = nblks; /* save for later use to calc level > 1 overhead */ if (dn->dn_nlevels == 1) { int i; for (i = 0; i < nblks; i++) { blkptr_t *bp = dn->dn_phys->dn_blkptr; ASSERT3U(blkid + i, <, dn->dn_nblkptr); bp += blkid + i; if (dsl_dataset_block_freeable(ds, bp, bp->blk_birth)) { dprintf_bp(bp, "can free old%s", ""); space += bp_get_dsize(spa, bp); } unref += BP_GET_ASIZE(bp); } nl1blks = 1; nblks = 0; } lastblk = blkid + nblks - 1; while (nblks) { dmu_buf_impl_t *dbuf; uint64_t ibyte, new_blkid; int epb = 1 << epbs; int err, i, blkoff, tochk; blkptr_t *bp; ibyte = blkid << dn->dn_datablkshift; err = dnode_next_offset(dn, DNODE_FIND_HAVELOCK, &ibyte, 2, 1, 0); new_blkid = ibyte >> dn->dn_datablkshift; if (err == ESRCH) { skipped += (lastblk >> epbs) - (blkid >> epbs) + 1; break; } if (err) { txh->txh_tx->tx_err = err; break; } if (new_blkid > lastblk) { skipped += (lastblk >> epbs) - (blkid >> epbs) + 1; break; } if (new_blkid > blkid) { ASSERT((new_blkid >> epbs) > (blkid >> epbs)); skipped += (new_blkid >> epbs) - (blkid >> epbs) - 1; nblks -= new_blkid - blkid; blkid = new_blkid; } blkoff = P2PHASE(blkid, epb); tochk = MIN(epb - blkoff, nblks); err = dbuf_hold_impl(dn, 1, blkid >> epbs, FALSE, FTAG, &dbuf); if (err) { txh->txh_tx->tx_err = err; break; } txh->txh_memory_tohold += dbuf->db.db_size; /* * We don't check memory_tohold against DMU_MAX_ACCESS because * memory_tohold is an over-estimation (especially the >L1 * indirect blocks), so it could fail. Callers should have * already verified that they will not be holding too much * memory. */ err = dbuf_read(dbuf, NULL, DB_RF_HAVESTRUCT | DB_RF_CANFAIL); if (err != 0) { txh->txh_tx->tx_err = err; dbuf_rele(dbuf, FTAG); break; } bp = dbuf->db.db_data; bp += blkoff; for (i = 0; i < tochk; i++) { if (dsl_dataset_block_freeable(ds, &bp[i], bp[i].blk_birth)) { dprintf_bp(&bp[i], "can free old%s", ""); space += bp_get_dsize(spa, &bp[i]); } unref += BP_GET_ASIZE(bp); } dbuf_rele(dbuf, FTAG); ++nl1blks; blkid += tochk; nblks -= tochk; } rw_exit(&dn->dn_struct_rwlock); /* * Add in memory requirements of higher-level indirects. * This assumes a worst-possible scenario for dn_nlevels and a * worst-possible distribution of l1-blocks over the region to free. */ { uint64_t blkcnt = 1 + ((l0span >> epbs) >> epbs); int level = 2; /* * Here we don't use DN_MAX_LEVEL, but calculate it with the * given datablkshift and indblkshift. This makes the * difference between 19 and 8 on large files. */ int maxlevel = 2 + (DN_MAX_OFFSET_SHIFT - dn->dn_datablkshift) / (dn->dn_indblkshift - SPA_BLKPTRSHIFT); while (level++ < maxlevel) { txh->txh_memory_tohold += MAX(MIN(blkcnt, nl1blks), 1) << dn->dn_indblkshift; blkcnt = 1 + (blkcnt >> epbs); } } /* account for new level 1 indirect blocks that might show up */ if (skipped > 0) { txh->txh_fudge += skipped << dn->dn_indblkshift; skipped = MIN(skipped, DMU_MAX_DELETEBLKCNT >> epbs); txh->txh_memory_tohold += skipped << dn->dn_indblkshift; } txh->txh_space_tofree += space; txh->txh_space_tounref += unref; } /* * This function marks the transaction as being a "net free". The end * result is that refquotas will be disabled for this transaction, and * this transaction will be able to use half of the pool space overhead * (see dsl_pool_adjustedsize()). Therefore this function should only * be called for transactions that we expect will not cause a net increase * in the amount of space used (but it's OK if that is occasionally not true). */ void dmu_tx_mark_netfree(dmu_tx_t *tx) { dmu_tx_hold_t *txh; txh = dmu_tx_hold_object_impl(tx, tx->tx_objset, DMU_NEW_OBJECT, THT_FREE, 0, 0); /* * Pretend that this operation will free 1GB of space. This * should be large enough to cancel out the largest write. * We don't want to use something like UINT64_MAX, because that would * cause overflows when doing math with these values (e.g. in * dmu_tx_try_assign()). */ txh->txh_space_tofree = txh->txh_space_tounref = 1024 * 1024 * 1024; } void dmu_tx_hold_free(dmu_tx_t *tx, uint64_t object, uint64_t off, uint64_t len) { dmu_tx_hold_t *txh; dnode_t *dn; int err; zio_t *zio; ASSERT(tx->tx_txg == 0); txh = dmu_tx_hold_object_impl(tx, tx->tx_objset, object, THT_FREE, off, len); if (txh == NULL) return; dn = txh->txh_dnode; dmu_tx_count_dnode(txh); if (off >= (dn->dn_maxblkid+1) * dn->dn_datablksz) return; if (len == DMU_OBJECT_END) len = (dn->dn_maxblkid+1) * dn->dn_datablksz - off; /* * For i/o error checking, we read the first and last level-0 * blocks if they are not aligned, and all the level-1 blocks. * * Note: dbuf_free_range() assumes that we have not instantiated * any level-0 dbufs that will be completely freed. Therefore we must * exercise care to not read or count the first and last blocks * if they are blocksize-aligned. */ if (dn->dn_datablkshift == 0) { if (off != 0 || len < dn->dn_datablksz) dmu_tx_count_write(txh, 0, dn->dn_datablksz); } else { /* first block will be modified if it is not aligned */ if (!IS_P2ALIGNED(off, 1 << dn->dn_datablkshift)) dmu_tx_count_write(txh, off, 1); /* last block will be modified if it is not aligned */ if (!IS_P2ALIGNED(off + len, 1 << dn->dn_datablkshift)) dmu_tx_count_write(txh, off+len, 1); } /* * Check level-1 blocks. */ if (dn->dn_nlevels > 1) { int shift = dn->dn_datablkshift + dn->dn_indblkshift - SPA_BLKPTRSHIFT; uint64_t start = off >> shift; uint64_t end = (off + len) >> shift; ASSERT(dn->dn_indblkshift != 0); /* * dnode_reallocate() can result in an object with indirect * blocks having an odd data block size. In this case, * just check the single block. */ if (dn->dn_datablkshift == 0) start = end = 0; zio = zio_root(tx->tx_pool->dp_spa, NULL, NULL, ZIO_FLAG_CANFAIL); for (uint64_t i = start; i <= end; i++) { uint64_t ibyte = i << shift; err = dnode_next_offset(dn, 0, &ibyte, 2, 1, 0); i = ibyte >> shift; if (err == ESRCH) break; if (err) { tx->tx_err = err; return; } err = dmu_tx_check_ioerr(zio, dn, 1, i); if (err) { tx->tx_err = err; return; } } err = zio_wait(zio); if (err) { tx->tx_err = err; return; } } dmu_tx_count_free(txh, off, len); } void dmu_tx_hold_zap(dmu_tx_t *tx, uint64_t object, int add, const char *name) { dmu_tx_hold_t *txh; dnode_t *dn; uint64_t nblocks; int epbs, err; ASSERT(tx->tx_txg == 0); txh = dmu_tx_hold_object_impl(tx, tx->tx_objset, object, THT_ZAP, add, (uintptr_t)name); if (txh == NULL) return; dn = txh->txh_dnode; dmu_tx_count_dnode(txh); if (dn == NULL) { /* * We will be able to fit a new object's entries into one leaf * block. So there will be at most 2 blocks total, * including the header block. */ dmu_tx_count_write(txh, 0, 2 << fzap_default_block_shift); return; } ASSERT3P(DMU_OT_BYTESWAP(dn->dn_type), ==, DMU_BSWAP_ZAP); if (dn->dn_maxblkid == 0 && !add) { blkptr_t *bp; /* * If there is only one block (i.e. this is a micro-zap) * and we are not adding anything, the accounting is simple. */ err = dmu_tx_check_ioerr(NULL, dn, 0, 0); if (err) { tx->tx_err = err; return; } /* * Use max block size here, since we don't know how much * the size will change between now and the dbuf dirty call. */ bp = &dn->dn_phys->dn_blkptr[0]; if (dsl_dataset_block_freeable(dn->dn_objset->os_dsl_dataset, bp, bp->blk_birth)) txh->txh_space_tooverwrite += SPA_MAXBLOCKSIZE; else txh->txh_space_towrite += SPA_MAXBLOCKSIZE; if (!BP_IS_HOLE(bp)) txh->txh_space_tounref += SPA_MAXBLOCKSIZE; return; } if (dn->dn_maxblkid > 0 && name) { /* * access the name in this fat-zap so that we'll check * for i/o errors to the leaf blocks, etc. */ err = zap_lookup(dn->dn_objset, dn->dn_object, name, 8, 0, NULL); if (err == EIO) { tx->tx_err = err; return; } } err = zap_count_write(dn->dn_objset, dn->dn_object, name, add, &txh->txh_space_towrite, &txh->txh_space_tooverwrite); /* * If the modified blocks are scattered to the four winds, * we'll have to modify an indirect twig for each. */ epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT; for (nblocks = dn->dn_maxblkid >> epbs; nblocks != 0; nblocks >>= epbs) if (dn->dn_objset->os_dsl_dataset->ds_phys->ds_prev_snap_obj) txh->txh_space_towrite += 3 << dn->dn_indblkshift; else txh->txh_space_tooverwrite += 3 << dn->dn_indblkshift; } void dmu_tx_hold_bonus(dmu_tx_t *tx, uint64_t object) { dmu_tx_hold_t *txh; ASSERT(tx->tx_txg == 0); txh = dmu_tx_hold_object_impl(tx, tx->tx_objset, object, THT_BONUS, 0, 0); if (txh) dmu_tx_count_dnode(txh); } void dmu_tx_hold_space(dmu_tx_t *tx, uint64_t space) { dmu_tx_hold_t *txh; ASSERT(tx->tx_txg == 0); txh = dmu_tx_hold_object_impl(tx, tx->tx_objset, DMU_NEW_OBJECT, THT_SPACE, space, 0); txh->txh_space_towrite += space; } int dmu_tx_holds(dmu_tx_t *tx, uint64_t object) { dmu_tx_hold_t *txh; int holds = 0; /* * By asserting that the tx is assigned, we're counting the * number of dn_tx_holds, which is the same as the number of * dn_holds. Otherwise, we'd be counting dn_holds, but * dn_tx_holds could be 0. */ ASSERT(tx->tx_txg != 0); /* if (tx->tx_anyobj == TRUE) */ /* return (0); */ for (txh = list_head(&tx->tx_holds); txh; txh = list_next(&tx->tx_holds, txh)) { if (txh->txh_dnode && txh->txh_dnode->dn_object == object) holds++; } return (holds); } #ifdef ZFS_DEBUG void dmu_tx_dirty_buf(dmu_tx_t *tx, dmu_buf_impl_t *db) { dmu_tx_hold_t *txh; int match_object = FALSE, match_offset = FALSE; dnode_t *dn; DB_DNODE_ENTER(db); dn = DB_DNODE(db); ASSERT(tx->tx_txg != 0); ASSERT(tx->tx_objset == NULL || dn->dn_objset == tx->tx_objset); ASSERT3U(dn->dn_object, ==, db->db.db_object); if (tx->tx_anyobj) { DB_DNODE_EXIT(db); return; } /* XXX No checking on the meta dnode for now */ if (db->db.db_object == DMU_META_DNODE_OBJECT) { DB_DNODE_EXIT(db); return; } for (txh = list_head(&tx->tx_holds); txh; txh = list_next(&tx->tx_holds, txh)) { ASSERT(dn == NULL || dn->dn_assigned_txg == tx->tx_txg); if (txh->txh_dnode == dn && txh->txh_type != THT_NEWOBJECT) match_object = TRUE; if (txh->txh_dnode == NULL || txh->txh_dnode == dn) { int datablkshift = dn->dn_datablkshift ? dn->dn_datablkshift : SPA_MAXBLOCKSHIFT; int epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT; int shift = datablkshift + epbs * db->db_level; uint64_t beginblk = shift >= 64 ? 0 : (txh->txh_arg1 >> shift); uint64_t endblk = shift >= 64 ? 0 : ((txh->txh_arg1 + txh->txh_arg2 - 1) >> shift); uint64_t blkid = db->db_blkid; /* XXX txh_arg2 better not be zero... */ dprintf("found txh type %x beginblk=%llx endblk=%llx\n", txh->txh_type, beginblk, endblk); switch (txh->txh_type) { case THT_WRITE: if (blkid >= beginblk && blkid <= endblk) match_offset = TRUE; /* * We will let this hold work for the bonus * or spill buffer so that we don't need to * hold it when creating a new object. */ if (blkid == DMU_BONUS_BLKID || blkid == DMU_SPILL_BLKID) match_offset = TRUE; /* * They might have to increase nlevels, * thus dirtying the new TLIBs. Or the * might have to change the block size, * thus dirying the new lvl=0 blk=0. */ if (blkid == 0) match_offset = TRUE; break; case THT_FREE: /* * We will dirty all the level 1 blocks in * the free range and perhaps the first and * last level 0 block. */ if (blkid >= beginblk && (blkid <= endblk || txh->txh_arg2 == DMU_OBJECT_END)) match_offset = TRUE; break; case THT_SPILL: if (blkid == DMU_SPILL_BLKID) match_offset = TRUE; break; case THT_BONUS: if (blkid == DMU_BONUS_BLKID) match_offset = TRUE; break; case THT_ZAP: match_offset = TRUE; break; case THT_NEWOBJECT: match_object = TRUE; break; default: ASSERT(!"bad txh_type"); } } if (match_object && match_offset) { DB_DNODE_EXIT(db); return; } } DB_DNODE_EXIT(db); panic("dirtying dbuf obj=%llx lvl=%u blkid=%llx but not tx_held\n", (u_longlong_t)db->db.db_object, db->db_level, (u_longlong_t)db->db_blkid); } #endif /* * If we can't do 10 iops, something is wrong. Let us go ahead * and hit zfs_dirty_data_max. */ hrtime_t zfs_delay_max_ns = MSEC2NSEC(100); int zfs_delay_resolution_ns = 100 * 1000; /* 100 microseconds */ /* * We delay transactions when we've determined that the backend storage * isn't able to accommodate the rate of incoming writes. * * If there is already a transaction waiting, we delay relative to when * that transaction finishes waiting. This way the calculated min_time * is independent of the number of threads concurrently executing * transactions. * * If we are the only waiter, wait relative to when the transaction * started, rather than the current time. This credits the transaction for * "time already served", e.g. reading indirect blocks. * * The minimum time for a transaction to take is calculated as: * min_time = scale * (dirty - min) / (max - dirty) * min_time is then capped at zfs_delay_max_ns. * * The delay has two degrees of freedom that can be adjusted via tunables. * The percentage of dirty data at which we start to delay is defined by * zfs_delay_min_dirty_percent. This should typically be at or above * zfs_vdev_async_write_active_max_dirty_percent so that we only start to * delay after writing at full speed has failed to keep up with the incoming * write rate. The scale of the curve is defined by zfs_delay_scale. Roughly * speaking, this variable determines the amount of delay at the midpoint of * the curve. * * delay * 10ms +-------------------------------------------------------------*+ * | *| * 9ms + *+ * | *| * 8ms + *+ * | * | * 7ms + * + * | * | * 6ms + * + * | * | * 5ms + * + * | * | * 4ms + * + * | * | * 3ms + * + * | * | * 2ms + (midpoint) * + * | | ** | * 1ms + v *** + * | zfs_delay_scale ----------> ******** | * 0 +-------------------------------------*********----------------+ * 0% <- zfs_dirty_data_max -> 100% * * Note that since the delay is added to the outstanding time remaining on the * most recent transaction, the delay is effectively the inverse of IOPS. * Here the midpoint of 500us translates to 2000 IOPS. The shape of the curve * was chosen such that small changes in the amount of accumulated dirty data * in the first 3/4 of the curve yield relatively small differences in the * amount of delay. * * The effects can be easier to understand when the amount of delay is * represented on a log scale: * * delay * 100ms +-------------------------------------------------------------++ * + + * | | * + *+ * 10ms + *+ * + ** + * | (midpoint) ** | * + | ** + * 1ms + v **** + * + zfs_delay_scale ----------> ***** + * | **** | * + **** + * 100us + ** + * + * + * | * | * + * + * 10us + * + * + + * | | * + + * +--------------------------------------------------------------+ * 0% <- zfs_dirty_data_max -> 100% * * Note here that only as the amount of dirty data approaches its limit does * the delay start to increase rapidly. The goal of a properly tuned system * should be to keep the amount of dirty data out of that range by first * ensuring that the appropriate limits are set for the I/O scheduler to reach * optimal throughput on the backend storage, and then by changing the value * of zfs_delay_scale to increase the steepness of the curve. */ static void dmu_tx_delay(dmu_tx_t *tx, uint64_t dirty) { dsl_pool_t *dp = tx->tx_pool; uint64_t delay_min_bytes = zfs_dirty_data_max * zfs_delay_min_dirty_percent / 100; hrtime_t wakeup, min_tx_time, now; if (dirty <= delay_min_bytes) return; /* * The caller has already waited until we are under the max. * We make them pass us the amount of dirty data so we don't * have to handle the case of it being >= the max, which could * cause a divide-by-zero if it's == the max. */ ASSERT3U(dirty, <, zfs_dirty_data_max); now = gethrtime(); min_tx_time = zfs_delay_scale * (dirty - delay_min_bytes) / (zfs_dirty_data_max - dirty); if (now > tx->tx_start + min_tx_time) return; min_tx_time = MIN(min_tx_time, zfs_delay_max_ns); DTRACE_PROBE3(delay__mintime, dmu_tx_t *, tx, uint64_t, dirty, uint64_t, min_tx_time); mutex_enter(&dp->dp_lock); wakeup = MAX(tx->tx_start + min_tx_time, dp->dp_last_wakeup + min_tx_time); dp->dp_last_wakeup = wakeup; mutex_exit(&dp->dp_lock); #ifdef _KERNEL mutex_enter(&curthread->t_delay_lock); while (cv_timedwait_hires(&curthread->t_delay_cv, &curthread->t_delay_lock, wakeup, zfs_delay_resolution_ns, CALLOUT_FLAG_ABSOLUTE | CALLOUT_FLAG_ROUNDUP) > 0) continue; mutex_exit(&curthread->t_delay_lock); #else hrtime_t delta = wakeup - gethrtime(); struct timespec ts; ts.tv_sec = delta / NANOSEC; ts.tv_nsec = delta % NANOSEC; (void) nanosleep(&ts, NULL); #endif } static int dmu_tx_try_assign(dmu_tx_t *tx, txg_how_t txg_how) { dmu_tx_hold_t *txh; spa_t *spa = tx->tx_pool->dp_spa; uint64_t memory, asize, fsize, usize; uint64_t towrite, tofree, tooverwrite, tounref, tohold, fudge; ASSERT0(tx->tx_txg); if (tx->tx_err) return (tx->tx_err); if (spa_suspended(spa)) { /* * If the user has indicated a blocking failure mode * then return ERESTART which will block in dmu_tx_wait(). * Otherwise, return EIO so that an error can get * propagated back to the VOP calls. * * Note that we always honor the txg_how flag regardless * of the failuremode setting. */ if (spa_get_failmode(spa) == ZIO_FAILURE_MODE_CONTINUE && txg_how != TXG_WAIT) return (SET_ERROR(EIO)); return (SET_ERROR(ERESTART)); } if (!tx->tx_waited && dsl_pool_need_dirty_delay(tx->tx_pool)) { tx->tx_wait_dirty = B_TRUE; return (SET_ERROR(ERESTART)); } tx->tx_txg = txg_hold_open(tx->tx_pool, &tx->tx_txgh); tx->tx_needassign_txh = NULL; /* * NB: No error returns are allowed after txg_hold_open, but * before processing the dnode holds, due to the * dmu_tx_unassign() logic. */ towrite = tofree = tooverwrite = tounref = tohold = fudge = 0; for (txh = list_head(&tx->tx_holds); txh; txh = list_next(&tx->tx_holds, txh)) { dnode_t *dn = txh->txh_dnode; if (dn != NULL) { mutex_enter(&dn->dn_mtx); if (dn->dn_assigned_txg == tx->tx_txg - 1) { mutex_exit(&dn->dn_mtx); tx->tx_needassign_txh = txh; return (SET_ERROR(ERESTART)); } if (dn->dn_assigned_txg == 0) dn->dn_assigned_txg = tx->tx_txg; ASSERT3U(dn->dn_assigned_txg, ==, tx->tx_txg); (void) refcount_add(&dn->dn_tx_holds, tx); mutex_exit(&dn->dn_mtx); } towrite += txh->txh_space_towrite; tofree += txh->txh_space_tofree; tooverwrite += txh->txh_space_tooverwrite; tounref += txh->txh_space_tounref; tohold += txh->txh_memory_tohold; fudge += txh->txh_fudge; } /* * If a snapshot has been taken since we made our estimates, * assume that we won't be able to free or overwrite anything. */ if (tx->tx_objset && dsl_dataset_prev_snap_txg(tx->tx_objset->os_dsl_dataset) > tx->tx_lastsnap_txg) { towrite += tooverwrite; tooverwrite = tofree = 0; } /* needed allocation: worst-case estimate of write space */ asize = spa_get_asize(tx->tx_pool->dp_spa, towrite + tooverwrite); /* freed space estimate: worst-case overwrite + free estimate */ fsize = spa_get_asize(tx->tx_pool->dp_spa, tooverwrite) + tofree; /* convert unrefd space to worst-case estimate */ usize = spa_get_asize(tx->tx_pool->dp_spa, tounref); /* calculate memory footprint estimate */ memory = towrite + tooverwrite + tohold; #ifdef ZFS_DEBUG /* * Add in 'tohold' to account for our dirty holds on this memory * XXX - the "fudge" factor is to account for skipped blocks that * we missed because dnode_next_offset() misses in-core-only blocks. */ tx->tx_space_towrite = asize + spa_get_asize(tx->tx_pool->dp_spa, tohold + fudge); tx->tx_space_tofree = tofree; tx->tx_space_tooverwrite = tooverwrite; tx->tx_space_tounref = tounref; #endif if (tx->tx_dir && asize != 0) { int err = dsl_dir_tempreserve_space(tx->tx_dir, memory, asize, fsize, usize, &tx->tx_tempreserve_cookie, tx); if (err) return (err); } return (0); } static void dmu_tx_unassign(dmu_tx_t *tx) { dmu_tx_hold_t *txh; if (tx->tx_txg == 0) return; txg_rele_to_quiesce(&tx->tx_txgh); /* * Walk the transaction's hold list, removing the hold on the * associated dnode, and notifying waiters if the refcount drops to 0. */ for (txh = list_head(&tx->tx_holds); txh != tx->tx_needassign_txh; txh = list_next(&tx->tx_holds, txh)) { dnode_t *dn = txh->txh_dnode; if (dn == NULL) continue; mutex_enter(&dn->dn_mtx); ASSERT3U(dn->dn_assigned_txg, ==, tx->tx_txg); if (refcount_remove(&dn->dn_tx_holds, tx) == 0) { dn->dn_assigned_txg = 0; cv_broadcast(&dn->dn_notxholds); } mutex_exit(&dn->dn_mtx); } txg_rele_to_sync(&tx->tx_txgh); tx->tx_lasttried_txg = tx->tx_txg; tx->tx_txg = 0; } /* * Assign tx to a transaction group. txg_how can be one of: * * (1) TXG_WAIT. If the current open txg is full, waits until there's * a new one. This should be used when you're not holding locks. * It will only fail if we're truly out of space (or over quota). * * (2) TXG_NOWAIT. If we can't assign into the current open txg without * blocking, returns immediately with ERESTART. This should be used * whenever you're holding locks. On an ERESTART error, the caller * should drop locks, do a dmu_tx_wait(tx), and try again. * * (3) TXG_WAITED. Like TXG_NOWAIT, but indicates that dmu_tx_wait() * has already been called on behalf of this operation (though * most likely on a different tx). */ int dmu_tx_assign(dmu_tx_t *tx, txg_how_t txg_how) { int err; ASSERT(tx->tx_txg == 0); ASSERT(txg_how == TXG_WAIT || txg_how == TXG_NOWAIT || txg_how == TXG_WAITED); ASSERT(!dsl_pool_sync_context(tx->tx_pool)); /* If we might wait, we must not hold the config lock. */ ASSERT(txg_how != TXG_WAIT || !dsl_pool_config_held(tx->tx_pool)); if (txg_how == TXG_WAITED) tx->tx_waited = B_TRUE; while ((err = dmu_tx_try_assign(tx, txg_how)) != 0) { dmu_tx_unassign(tx); if (err != ERESTART || txg_how != TXG_WAIT) return (err); dmu_tx_wait(tx); } txg_rele_to_quiesce(&tx->tx_txgh); return (0); } void dmu_tx_wait(dmu_tx_t *tx) { spa_t *spa = tx->tx_pool->dp_spa; dsl_pool_t *dp = tx->tx_pool; ASSERT(tx->tx_txg == 0); ASSERT(!dsl_pool_config_held(tx->tx_pool)); if (tx->tx_wait_dirty) { /* * dmu_tx_try_assign() has determined that we need to wait * because we've consumed much or all of the dirty buffer * space. */ mutex_enter(&dp->dp_lock); while (dp->dp_dirty_total >= zfs_dirty_data_max) cv_wait(&dp->dp_spaceavail_cv, &dp->dp_lock); uint64_t dirty = dp->dp_dirty_total; mutex_exit(&dp->dp_lock); dmu_tx_delay(tx, dirty); tx->tx_wait_dirty = B_FALSE; /* * Note: setting tx_waited only has effect if the caller * used TX_WAIT. Otherwise they are going to destroy * this tx and try again. The common case, zfs_write(), * uses TX_WAIT. */ tx->tx_waited = B_TRUE; } else if (spa_suspended(spa) || tx->tx_lasttried_txg == 0) { /* * If the pool is suspended we need to wait until it * is resumed. Note that it's possible that the pool * has become active after this thread has tried to * obtain a tx. If that's the case then tx_lasttried_txg * would not have been set. */ txg_wait_synced(dp, spa_last_synced_txg(spa) + 1); } else if (tx->tx_needassign_txh) { /* * A dnode is assigned to the quiescing txg. Wait for its * transaction to complete. */ dnode_t *dn = tx->tx_needassign_txh->txh_dnode; mutex_enter(&dn->dn_mtx); while (dn->dn_assigned_txg == tx->tx_lasttried_txg - 1) cv_wait(&dn->dn_notxholds, &dn->dn_mtx); mutex_exit(&dn->dn_mtx); tx->tx_needassign_txh = NULL; } else { txg_wait_open(tx->tx_pool, tx->tx_lasttried_txg + 1); } } void dmu_tx_willuse_space(dmu_tx_t *tx, int64_t delta) { #ifdef ZFS_DEBUG if (tx->tx_dir == NULL || delta == 0) return; if (delta > 0) { ASSERT3U(refcount_count(&tx->tx_space_written) + delta, <=, tx->tx_space_towrite); (void) refcount_add_many(&tx->tx_space_written, delta, NULL); } else { (void) refcount_add_many(&tx->tx_space_freed, -delta, NULL); } #endif } void dmu_tx_commit(dmu_tx_t *tx) { dmu_tx_hold_t *txh; ASSERT(tx->tx_txg != 0); /* * Go through the transaction's hold list and remove holds on * associated dnodes, notifying waiters if no holds remain. */ while (txh = list_head(&tx->tx_holds)) { dnode_t *dn = txh->txh_dnode; list_remove(&tx->tx_holds, txh); kmem_free(txh, sizeof (dmu_tx_hold_t)); if (dn == NULL) continue; mutex_enter(&dn->dn_mtx); ASSERT3U(dn->dn_assigned_txg, ==, tx->tx_txg); if (refcount_remove(&dn->dn_tx_holds, tx) == 0) { dn->dn_assigned_txg = 0; cv_broadcast(&dn->dn_notxholds); } mutex_exit(&dn->dn_mtx); dnode_rele(dn, tx); } if (tx->tx_tempreserve_cookie) dsl_dir_tempreserve_clear(tx->tx_tempreserve_cookie, tx); if (!list_is_empty(&tx->tx_callbacks)) txg_register_callbacks(&tx->tx_txgh, &tx->tx_callbacks); if (tx->tx_anyobj == FALSE) txg_rele_to_sync(&tx->tx_txgh); list_destroy(&tx->tx_callbacks); list_destroy(&tx->tx_holds); #ifdef ZFS_DEBUG dprintf("towrite=%llu written=%llu tofree=%llu freed=%llu\n", tx->tx_space_towrite, refcount_count(&tx->tx_space_written), tx->tx_space_tofree, refcount_count(&tx->tx_space_freed)); refcount_destroy_many(&tx->tx_space_written, refcount_count(&tx->tx_space_written)); refcount_destroy_many(&tx->tx_space_freed, refcount_count(&tx->tx_space_freed)); #endif kmem_free(tx, sizeof (dmu_tx_t)); } void dmu_tx_abort(dmu_tx_t *tx) { dmu_tx_hold_t *txh; ASSERT(tx->tx_txg == 0); while (txh = list_head(&tx->tx_holds)) { dnode_t *dn = txh->txh_dnode; list_remove(&tx->tx_holds, txh); kmem_free(txh, sizeof (dmu_tx_hold_t)); if (dn != NULL) dnode_rele(dn, tx); } /* * Call any registered callbacks with an error code. */ if (!list_is_empty(&tx->tx_callbacks)) dmu_tx_do_callbacks(&tx->tx_callbacks, ECANCELED); list_destroy(&tx->tx_callbacks); list_destroy(&tx->tx_holds); #ifdef ZFS_DEBUG refcount_destroy_many(&tx->tx_space_written, refcount_count(&tx->tx_space_written)); refcount_destroy_many(&tx->tx_space_freed, refcount_count(&tx->tx_space_freed)); #endif kmem_free(tx, sizeof (dmu_tx_t)); } uint64_t dmu_tx_get_txg(dmu_tx_t *tx) { ASSERT(tx->tx_txg != 0); return (tx->tx_txg); } dsl_pool_t * dmu_tx_pool(dmu_tx_t *tx) { ASSERT(tx->tx_pool != NULL); return (tx->tx_pool); } void dmu_tx_callback_register(dmu_tx_t *tx, dmu_tx_callback_func_t *func, void *data) { dmu_tx_callback_t *dcb; dcb = kmem_alloc(sizeof (dmu_tx_callback_t), KM_SLEEP); dcb->dcb_func = func; dcb->dcb_data = data; list_insert_tail(&tx->tx_callbacks, dcb); } /* * Call all the commit callbacks on a list, with a given error code. */ void dmu_tx_do_callbacks(list_t *cb_list, int error) { dmu_tx_callback_t *dcb; while (dcb = list_head(cb_list)) { list_remove(cb_list, dcb); dcb->dcb_func(dcb->dcb_data, error); kmem_free(dcb, sizeof (dmu_tx_callback_t)); } } /* * Interface to hold a bunch of attributes. * used for creating new files. * attrsize is the total size of all attributes * to be added during object creation * * For updating/adding a single attribute dmu_tx_hold_sa() should be used. */ /* * hold necessary attribute name for attribute registration. * should be a very rare case where this is needed. If it does * happen it would only happen on the first write to the file system. */ static void dmu_tx_sa_registration_hold(sa_os_t *sa, dmu_tx_t *tx) { int i; if (!sa->sa_need_attr_registration) return; for (i = 0; i != sa->sa_num_attrs; i++) { if (!sa->sa_attr_table[i].sa_registered) { if (sa->sa_reg_attr_obj) dmu_tx_hold_zap(tx, sa->sa_reg_attr_obj, B_TRUE, sa->sa_attr_table[i].sa_name); else dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, B_TRUE, sa->sa_attr_table[i].sa_name); } } } void dmu_tx_hold_spill(dmu_tx_t *tx, uint64_t object) { dnode_t *dn; dmu_tx_hold_t *txh; txh = dmu_tx_hold_object_impl(tx, tx->tx_objset, object, THT_SPILL, 0, 0); dn = txh->txh_dnode; if (dn == NULL) return; /* If blkptr doesn't exist then add space to towrite */ if (!(dn->dn_phys->dn_flags & DNODE_FLAG_SPILL_BLKPTR)) { txh->txh_space_towrite += SPA_MAXBLOCKSIZE; } else { blkptr_t *bp; bp = &dn->dn_phys->dn_spill; if (dsl_dataset_block_freeable(dn->dn_objset->os_dsl_dataset, bp, bp->blk_birth)) txh->txh_space_tooverwrite += SPA_MAXBLOCKSIZE; else txh->txh_space_towrite += SPA_MAXBLOCKSIZE; if (!BP_IS_HOLE(bp)) txh->txh_space_tounref += SPA_MAXBLOCKSIZE; } } void dmu_tx_hold_sa_create(dmu_tx_t *tx, int attrsize) { sa_os_t *sa = tx->tx_objset->os_sa; dmu_tx_hold_bonus(tx, DMU_NEW_OBJECT); if (tx->tx_objset->os_sa->sa_master_obj == 0) return; if (tx->tx_objset->os_sa->sa_layout_attr_obj) dmu_tx_hold_zap(tx, sa->sa_layout_attr_obj, B_TRUE, NULL); else { dmu_tx_hold_zap(tx, sa->sa_master_obj, B_TRUE, SA_LAYOUTS); dmu_tx_hold_zap(tx, sa->sa_master_obj, B_TRUE, SA_REGISTRY); dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, B_TRUE, NULL); dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, B_TRUE, NULL); } dmu_tx_sa_registration_hold(sa, tx); if (attrsize <= DN_MAX_BONUSLEN && !sa->sa_force_spill) return; (void) dmu_tx_hold_object_impl(tx, tx->tx_objset, DMU_NEW_OBJECT, THT_SPILL, 0, 0); } /* * Hold SA attribute * * dmu_tx_hold_sa(dmu_tx_t *tx, sa_handle_t *, attribute, add, size) * * variable_size is the total size of all variable sized attributes * passed to this function. It is not the total size of all * variable size attributes that *may* exist on this object. */ void dmu_tx_hold_sa(dmu_tx_t *tx, sa_handle_t *hdl, boolean_t may_grow) { uint64_t object; sa_os_t *sa = tx->tx_objset->os_sa; ASSERT(hdl != NULL); object = sa_handle_object(hdl); dmu_tx_hold_bonus(tx, object); if (tx->tx_objset->os_sa->sa_master_obj == 0) return; if (tx->tx_objset->os_sa->sa_reg_attr_obj == 0 || tx->tx_objset->os_sa->sa_layout_attr_obj == 0) { dmu_tx_hold_zap(tx, sa->sa_master_obj, B_TRUE, SA_LAYOUTS); dmu_tx_hold_zap(tx, sa->sa_master_obj, B_TRUE, SA_REGISTRY); dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, B_TRUE, NULL); dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, B_TRUE, NULL); } dmu_tx_sa_registration_hold(sa, tx); if (may_grow && tx->tx_objset->os_sa->sa_layout_attr_obj) dmu_tx_hold_zap(tx, sa->sa_layout_attr_obj, B_TRUE, NULL); if (sa->sa_force_spill || may_grow || hdl->sa_spill) { ASSERT(tx->tx_txg == 0); dmu_tx_hold_spill(tx, object); } else { dmu_buf_impl_t *db = (dmu_buf_impl_t *)hdl->sa_bonus; dnode_t *dn; DB_DNODE_ENTER(db); dn = DB_DNODE(db); if (dn->dn_have_spill) { ASSERT(tx->tx_txg == 0); dmu_tx_hold_spill(tx, object); } DB_DNODE_EXIT(db); } }