diff options
Diffstat (limited to 'usr/src/uts/common/fs/zfs/dmu.c')
| -rw-r--r-- | usr/src/uts/common/fs/zfs/dmu.c | 124 |
1 files changed, 124 insertions, 0 deletions
diff --git a/usr/src/uts/common/fs/zfs/dmu.c b/usr/src/uts/common/fs/zfs/dmu.c index fde295d851..41600208c8 100644 --- a/usr/src/uts/common/fs/zfs/dmu.c +++ b/usr/src/uts/common/fs/zfs/dmu.c @@ -65,6 +65,13 @@ int zfs_nopwrite_enabled = 1; */ uint32_t zfs_per_txg_dirty_frees_percent = 30; +/* + * This can be used for testing, to ensure that certain actions happen + * while in the middle of a remap (which might otherwise complete too + * quickly). + */ +int zfs_object_remap_one_indirect_delay_ticks = 0; + const dmu_object_type_info_t dmu_ot[DMU_OT_NUMTYPES] = { { DMU_BSWAP_UINT8, TRUE, "unallocated" }, { DMU_BSWAP_ZAP, TRUE, "object directory" }, @@ -1014,6 +1021,123 @@ dmu_write_by_dnode(dnode_t *dn, uint64_t offset, uint64_t size, dmu_buf_rele_array(dbp, numbufs, FTAG); } +static int +dmu_object_remap_one_indirect(objset_t *os, dnode_t *dn, + uint64_t last_removal_txg, uint64_t offset) +{ + uint64_t l1blkid = dbuf_whichblock(dn, 1, offset); + int err = 0; + + rw_enter(&dn->dn_struct_rwlock, RW_READER); + dmu_buf_impl_t *dbuf = dbuf_hold_level(dn, 1, l1blkid, FTAG); + ASSERT3P(dbuf, !=, NULL); + + /* + * If the block hasn't been written yet, this default will ensure + * we don't try to remap it. + */ + uint64_t birth = UINT64_MAX; + ASSERT3U(last_removal_txg, !=, UINT64_MAX); + if (dbuf->db_blkptr != NULL) + birth = dbuf->db_blkptr->blk_birth; + rw_exit(&dn->dn_struct_rwlock); + + /* + * If this L1 was already written after the last removal, then we've + * already tried to remap it. + */ + if (birth <= last_removal_txg && + dbuf_read(dbuf, NULL, DB_RF_MUST_SUCCEED) == 0 && + dbuf_can_remap(dbuf)) { + dmu_tx_t *tx = dmu_tx_create(os); + dmu_tx_hold_remap_l1indirect(tx, dn->dn_object); + err = dmu_tx_assign(tx, TXG_WAIT); + if (err == 0) { + (void) dbuf_dirty(dbuf, tx); + dmu_tx_commit(tx); + } else { + dmu_tx_abort(tx); + } + } + + dbuf_rele(dbuf, FTAG); + + delay(zfs_object_remap_one_indirect_delay_ticks); + + return (err); +} + +/* + * Remap all blockpointers in the object, if possible, so that they reference + * only concrete vdevs. + * + * To do this, iterate over the L0 blockpointers and remap any that reference + * an indirect vdev. Note that we only examine L0 blockpointers; since we + * cannot guarantee that we can remap all blockpointer anyways (due to split + * blocks), we do not want to make the code unnecessarily complicated to + * catch the unlikely case that there is an L1 block on an indirect vdev that + * contains no indirect blockpointers. + */ +int +dmu_object_remap_indirects(objset_t *os, uint64_t object, + uint64_t last_removal_txg) +{ + uint64_t offset, l1span; + int err; + dnode_t *dn; + + err = dnode_hold(os, object, FTAG, &dn); + if (err != 0) { + return (err); + } + + if (dn->dn_nlevels <= 1) { + if (issig(JUSTLOOKING) && issig(FORREAL)) { + err = SET_ERROR(EINTR); + } + + /* + * If the dnode has no indirect blocks, we cannot dirty them. + * We still want to remap the blkptr(s) in the dnode if + * appropriate, so mark it as dirty. + */ + if (err == 0 && dnode_needs_remap(dn)) { + dmu_tx_t *tx = dmu_tx_create(os); + dmu_tx_hold_bonus(tx, dn->dn_object); + if ((err = dmu_tx_assign(tx, TXG_WAIT)) == 0) { + dnode_setdirty(dn, tx); + dmu_tx_commit(tx); + } else { + dmu_tx_abort(tx); + } + } + + dnode_rele(dn, FTAG); + return (err); + } + + offset = 0; + l1span = 1ULL << (dn->dn_indblkshift - SPA_BLKPTRSHIFT + + dn->dn_datablkshift); + /* + * Find the next L1 indirect that is not a hole. + */ + while (dnode_next_offset(dn, 0, &offset, 2, 1, 0) == 0) { + if (issig(JUSTLOOKING) && issig(FORREAL)) { + err = SET_ERROR(EINTR); + break; + } + if ((err = dmu_object_remap_one_indirect(os, dn, + last_removal_txg, offset)) != 0) { + break; + } + offset += l1span; + } + + dnode_rele(dn, FTAG); + return (err); +} + void dmu_prealloc(objset_t *os, uint64_t object, uint64_t offset, uint64_t size, dmu_tx_t *tx) |