diff options
Diffstat (limited to 'module/zfs/dmu_object.c')
| -rw-r--r-- | module/zfs/dmu_object.c | 525 |
1 files changed, 525 insertions, 0 deletions
diff --git a/module/zfs/dmu_object.c b/module/zfs/dmu_object.c new file mode 100644 index 0000000000000..453a2842ce6e6 --- /dev/null +++ b/module/zfs/dmu_object.c @@ -0,0 +1,525 @@ +/* + * 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 (c) 2013, 2017 by Delphix. All rights reserved. + * Copyright 2014 HybridCluster. All rights reserved. + */ + +#include <sys/dbuf.h> +#include <sys/dmu.h> +#include <sys/dmu_impl.h> +#include <sys/dmu_objset.h> +#include <sys/dmu_tx.h> +#include <sys/dnode.h> +#include <sys/zap.h> +#include <sys/zfeature.h> +#include <sys/dsl_dataset.h> + +/* + * Each of the concurrent object allocators will grab + * 2^dmu_object_alloc_chunk_shift dnode slots at a time. The default is to + * grab 128 slots, which is 4 blocks worth. This was experimentally + * determined to be the lowest value that eliminates the measurable effect + * of lock contention from this code path. + */ +int dmu_object_alloc_chunk_shift = 7; + +static uint64_t +dmu_object_alloc_impl(objset_t *os, dmu_object_type_t ot, int blocksize, + int indirect_blockshift, dmu_object_type_t bonustype, int bonuslen, + int dnodesize, dnode_t **allocated_dnode, void *tag, dmu_tx_t *tx) +{ + uint64_t object; + uint64_t L1_dnode_count = DNODES_PER_BLOCK << + (DMU_META_DNODE(os)->dn_indblkshift - SPA_BLKPTRSHIFT); + dnode_t *dn = NULL; + int dn_slots = dnodesize >> DNODE_SHIFT; + boolean_t restarted = B_FALSE; + uint64_t *cpuobj = NULL; + int dnodes_per_chunk = 1 << dmu_object_alloc_chunk_shift; + int error; + + kpreempt_disable(); + cpuobj = &os->os_obj_next_percpu[CPU_SEQID % + os->os_obj_next_percpu_len]; + kpreempt_enable(); + + if (dn_slots == 0) { + dn_slots = DNODE_MIN_SLOTS; + } else { + ASSERT3S(dn_slots, >=, DNODE_MIN_SLOTS); + ASSERT3S(dn_slots, <=, DNODE_MAX_SLOTS); + } + + /* + * The "chunk" of dnodes that is assigned to a CPU-specific + * allocator needs to be at least one block's worth, to avoid + * lock contention on the dbuf. It can be at most one L1 block's + * worth, so that the "rescan after polishing off a L1's worth" + * logic below will be sure to kick in. + */ + if (dnodes_per_chunk < DNODES_PER_BLOCK) + dnodes_per_chunk = DNODES_PER_BLOCK; + if (dnodes_per_chunk > L1_dnode_count) + dnodes_per_chunk = L1_dnode_count; + + /* + * The caller requested the dnode be returned as a performance + * optimization in order to avoid releasing the hold only to + * immediately reacquire it. Since they caller is responsible + * for releasing the hold they must provide the tag. + */ + if (allocated_dnode != NULL) { + ASSERT3P(tag, !=, NULL); + } else { + ASSERT3P(tag, ==, NULL); + tag = FTAG; + } + + object = *cpuobj; + for (;;) { + /* + * If we finished a chunk of dnodes, get a new one from + * the global allocator. + */ + if ((P2PHASE(object, dnodes_per_chunk) == 0) || + (P2PHASE(object + dn_slots - 1, dnodes_per_chunk) < + dn_slots)) { + DNODE_STAT_BUMP(dnode_alloc_next_chunk); + mutex_enter(&os->os_obj_lock); + ASSERT0(P2PHASE(os->os_obj_next_chunk, + dnodes_per_chunk)); + object = os->os_obj_next_chunk; + + /* + * Each time we polish off a L1 bp worth of dnodes + * (2^12 objects), move to another L1 bp that's + * still reasonably sparse (at most 1/4 full). Look + * from the beginning at most once per txg. If we + * still can't allocate from that L1 block, search + * for an empty L0 block, which will quickly skip + * to the end of the metadnode if no nearby L0 + * blocks are empty. This fallback avoids a + * pathology where full dnode blocks containing + * large dnodes appear sparse because they have a + * low blk_fill, leading to many failed allocation + * attempts. In the long term a better mechanism to + * search for sparse metadnode regions, such as + * spacemaps, could be implemented. + * + * os_scan_dnodes is set during txg sync if enough + * objects have been freed since the previous + * rescan to justify backfilling again. + * + * Note that dmu_traverse depends on the behavior + * that we use multiple blocks of the dnode object + * before going back to reuse objects. Any change + * to this algorithm should preserve that property + * or find another solution to the issues described + * in traverse_visitbp. + */ + if (P2PHASE(object, L1_dnode_count) == 0) { + uint64_t offset; + uint64_t blkfill; + int minlvl; + if (os->os_rescan_dnodes) { + offset = 0; + os->os_rescan_dnodes = B_FALSE; + } else { + offset = object << DNODE_SHIFT; + } + blkfill = restarted ? 1 : DNODES_PER_BLOCK >> 2; + minlvl = restarted ? 1 : 2; + restarted = B_TRUE; + error = dnode_next_offset(DMU_META_DNODE(os), + DNODE_FIND_HOLE, &offset, minlvl, + blkfill, 0); + if (error == 0) { + object = offset >> DNODE_SHIFT; + } + } + /* + * Note: if "restarted", we may find a L0 that + * is not suitably aligned. + */ + os->os_obj_next_chunk = + P2ALIGN(object, dnodes_per_chunk) + + dnodes_per_chunk; + (void) atomic_swap_64(cpuobj, object); + mutex_exit(&os->os_obj_lock); + } + + /* + * The value of (*cpuobj) before adding dn_slots is the object + * ID assigned to us. The value afterwards is the object ID + * assigned to whoever wants to do an allocation next. + */ + object = atomic_add_64_nv(cpuobj, dn_slots) - dn_slots; + + /* + * XXX We should check for an i/o error here and return + * up to our caller. Actually we should pre-read it in + * dmu_tx_assign(), but there is currently no mechanism + * to do so. + */ + error = dnode_hold_impl(os, object, DNODE_MUST_BE_FREE, + dn_slots, tag, &dn); + if (error == 0) { + rw_enter(&dn->dn_struct_rwlock, RW_WRITER); + /* + * Another thread could have allocated it; check + * again now that we have the struct lock. + */ + if (dn->dn_type == DMU_OT_NONE) { + dnode_allocate(dn, ot, blocksize, + indirect_blockshift, bonustype, + bonuslen, dn_slots, tx); + rw_exit(&dn->dn_struct_rwlock); + dmu_tx_add_new_object(tx, dn); + + /* + * Caller requested the allocated dnode be + * returned and is responsible for the hold. + */ + if (allocated_dnode != NULL) + *allocated_dnode = dn; + else + dnode_rele(dn, tag); + + return (object); + } + rw_exit(&dn->dn_struct_rwlock); + dnode_rele(dn, tag); + DNODE_STAT_BUMP(dnode_alloc_race); + } + + /* + * Skip to next known valid starting point on error. This + * is the start of the next block of dnodes. + */ + if (dmu_object_next(os, &object, B_TRUE, 0) != 0) { + object = P2ROUNDUP(object + 1, DNODES_PER_BLOCK); + DNODE_STAT_BUMP(dnode_alloc_next_block); + } + (void) atomic_swap_64(cpuobj, object); + } +} + +uint64_t +dmu_object_alloc(objset_t *os, dmu_object_type_t ot, int blocksize, + dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx) +{ + return dmu_object_alloc_impl(os, ot, blocksize, 0, bonustype, + bonuslen, 0, NULL, NULL, tx); +} + +uint64_t +dmu_object_alloc_ibs(objset_t *os, dmu_object_type_t ot, int blocksize, + int indirect_blockshift, dmu_object_type_t bonustype, int bonuslen, + dmu_tx_t *tx) +{ + return dmu_object_alloc_impl(os, ot, blocksize, indirect_blockshift, + bonustype, bonuslen, 0, NULL, NULL, tx); +} + +uint64_t +dmu_object_alloc_dnsize(objset_t *os, dmu_object_type_t ot, int blocksize, + dmu_object_type_t bonustype, int bonuslen, int dnodesize, dmu_tx_t *tx) +{ + return (dmu_object_alloc_impl(os, ot, blocksize, 0, bonustype, + bonuslen, dnodesize, NULL, NULL, tx)); +} + +/* + * Allocate a new object and return a pointer to the newly allocated dnode + * via the allocated_dnode argument. The returned dnode will be held and + * the caller is responsible for releasing the hold by calling dnode_rele(). + */ +uint64_t +dmu_object_alloc_hold(objset_t *os, dmu_object_type_t ot, int blocksize, + int indirect_blockshift, dmu_object_type_t bonustype, int bonuslen, + int dnodesize, dnode_t **allocated_dnode, void *tag, dmu_tx_t *tx) +{ + return (dmu_object_alloc_impl(os, ot, blocksize, indirect_blockshift, + bonustype, bonuslen, dnodesize, allocated_dnode, tag, tx)); +} + +int +dmu_object_claim(objset_t *os, uint64_t object, dmu_object_type_t ot, + int blocksize, dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx) +{ + return (dmu_object_claim_dnsize(os, object, ot, blocksize, bonustype, + bonuslen, 0, tx)); +} + +int +dmu_object_claim_dnsize(objset_t *os, uint64_t object, dmu_object_type_t ot, + int blocksize, dmu_object_type_t bonustype, int bonuslen, + int dnodesize, dmu_tx_t *tx) +{ + dnode_t *dn; + int dn_slots = dnodesize >> DNODE_SHIFT; + int err; + + if (dn_slots == 0) + dn_slots = DNODE_MIN_SLOTS; + ASSERT3S(dn_slots, >=, DNODE_MIN_SLOTS); + ASSERT3S(dn_slots, <=, DNODE_MAX_SLOTS); + + if (object == DMU_META_DNODE_OBJECT && !dmu_tx_private_ok(tx)) + return (SET_ERROR(EBADF)); + + err = dnode_hold_impl(os, object, DNODE_MUST_BE_FREE, dn_slots, + FTAG, &dn); + if (err) + return (err); + + dnode_allocate(dn, ot, blocksize, 0, bonustype, bonuslen, dn_slots, tx); + dmu_tx_add_new_object(tx, dn); + + dnode_rele(dn, FTAG); + + return (0); +} + +int +dmu_object_reclaim(objset_t *os, uint64_t object, dmu_object_type_t ot, + int blocksize, dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx) +{ + return (dmu_object_reclaim_dnsize(os, object, ot, blocksize, bonustype, + bonuslen, DNODE_MIN_SIZE, B_FALSE, tx)); +} + +int +dmu_object_reclaim_dnsize(objset_t *os, uint64_t object, dmu_object_type_t ot, + int blocksize, dmu_object_type_t bonustype, int bonuslen, int dnodesize, + boolean_t keep_spill, dmu_tx_t *tx) +{ + dnode_t *dn; + int dn_slots = dnodesize >> DNODE_SHIFT; + int err; + + if (dn_slots == 0) + dn_slots = DNODE_MIN_SLOTS; + + if (object == DMU_META_DNODE_OBJECT) + return (SET_ERROR(EBADF)); + + err = dnode_hold_impl(os, object, DNODE_MUST_BE_ALLOCATED, 0, + FTAG, &dn); + if (err) + return (err); + + dnode_reallocate(dn, ot, blocksize, bonustype, bonuslen, dn_slots, + keep_spill, tx); + + dnode_rele(dn, FTAG); + return (err); +} + +int +dmu_object_rm_spill(objset_t *os, uint64_t object, dmu_tx_t *tx) +{ + dnode_t *dn; + int err; + + err = dnode_hold_impl(os, object, DNODE_MUST_BE_ALLOCATED, 0, + FTAG, &dn); + if (err) + return (err); + + rw_enter(&dn->dn_struct_rwlock, RW_WRITER); + if (dn->dn_phys->dn_flags & DNODE_FLAG_SPILL_BLKPTR) { + dbuf_rm_spill(dn, tx); + dnode_rm_spill(dn, tx); + } + rw_exit(&dn->dn_struct_rwlock); + + dnode_rele(dn, FTAG); + return (err); +} + +int +dmu_object_free(objset_t *os, uint64_t object, dmu_tx_t *tx) +{ + dnode_t *dn; + int err; + + ASSERT(object != DMU_META_DNODE_OBJECT || dmu_tx_private_ok(tx)); + + err = dnode_hold_impl(os, object, DNODE_MUST_BE_ALLOCATED, 0, + FTAG, &dn); + if (err) + return (err); + + ASSERT(dn->dn_type != DMU_OT_NONE); + /* + * If we don't create this free range, we'll leak indirect blocks when + * we get to freeing the dnode in syncing context. + */ + dnode_free_range(dn, 0, DMU_OBJECT_END, tx); + dnode_free(dn, tx); + dnode_rele(dn, FTAG); + + return (0); +} + +/* + * Return (in *objectp) the next object which is allocated (or a hole) + * after *object, taking into account only objects that may have been modified + * after the specified txg. + */ +int +dmu_object_next(objset_t *os, uint64_t *objectp, boolean_t hole, uint64_t txg) +{ + uint64_t offset; + uint64_t start_obj; + struct dsl_dataset *ds = os->os_dsl_dataset; + int error; + + if (*objectp == 0) { + start_obj = 1; + } else if (ds && dsl_dataset_feature_is_active(ds, + SPA_FEATURE_LARGE_DNODE)) { + uint64_t i = *objectp + 1; + uint64_t last_obj = *objectp | (DNODES_PER_BLOCK - 1); + dmu_object_info_t doi; + + /* + * Scan through the remaining meta dnode block. The contents + * of each slot in the block are known so it can be quickly + * checked. If the block is exhausted without a match then + * hand off to dnode_next_offset() for further scanning. + */ + while (i <= last_obj) { + error = dmu_object_info(os, i, &doi); + if (error == ENOENT) { + if (hole) { + *objectp = i; + return (0); + } else { + i++; + } + } else if (error == EEXIST) { + i++; + } else if (error == 0) { + if (hole) { + i += doi.doi_dnodesize >> DNODE_SHIFT; + } else { + *objectp = i; + return (0); + } + } else { + return (error); + } + } + + start_obj = i; + } else { + start_obj = *objectp + 1; + } + + offset = start_obj << DNODE_SHIFT; + + error = dnode_next_offset(DMU_META_DNODE(os), + (hole ? DNODE_FIND_HOLE : 0), &offset, 0, DNODES_PER_BLOCK, txg); + + *objectp = offset >> DNODE_SHIFT; + + return (error); +} + +/* + * Turn this object from old_type into DMU_OTN_ZAP_METADATA, and bump the + * refcount on SPA_FEATURE_EXTENSIBLE_DATASET. + * + * Only for use from syncing context, on MOS objects. + */ +void +dmu_object_zapify(objset_t *mos, uint64_t object, dmu_object_type_t old_type, + dmu_tx_t *tx) +{ + dnode_t *dn; + + ASSERT(dmu_tx_is_syncing(tx)); + + VERIFY0(dnode_hold(mos, object, FTAG, &dn)); + if (dn->dn_type == DMU_OTN_ZAP_METADATA) { + dnode_rele(dn, FTAG); + return; + } + ASSERT3U(dn->dn_type, ==, old_type); + ASSERT0(dn->dn_maxblkid); + + /* + * We must initialize the ZAP data before changing the type, + * so that concurrent calls to *_is_zapified() can determine if + * the object has been completely zapified by checking the type. + */ + mzap_create_impl(dn, 0, 0, tx); + + dn->dn_next_type[tx->tx_txg & TXG_MASK] = dn->dn_type = + DMU_OTN_ZAP_METADATA; + dnode_setdirty(dn, tx); + dnode_rele(dn, FTAG); + + spa_feature_incr(dmu_objset_spa(mos), + SPA_FEATURE_EXTENSIBLE_DATASET, tx); +} + +void +dmu_object_free_zapified(objset_t *mos, uint64_t object, dmu_tx_t *tx) +{ + dnode_t *dn; + dmu_object_type_t t; + + ASSERT(dmu_tx_is_syncing(tx)); + + VERIFY0(dnode_hold(mos, object, FTAG, &dn)); + t = dn->dn_type; + dnode_rele(dn, FTAG); + + if (t == DMU_OTN_ZAP_METADATA) { + spa_feature_decr(dmu_objset_spa(mos), + SPA_FEATURE_EXTENSIBLE_DATASET, tx); + } + VERIFY0(dmu_object_free(mos, object, tx)); +} + +EXPORT_SYMBOL(dmu_object_alloc); +EXPORT_SYMBOL(dmu_object_alloc_ibs); +EXPORT_SYMBOL(dmu_object_alloc_dnsize); +EXPORT_SYMBOL(dmu_object_alloc_hold); +EXPORT_SYMBOL(dmu_object_claim); +EXPORT_SYMBOL(dmu_object_claim_dnsize); +EXPORT_SYMBOL(dmu_object_reclaim); +EXPORT_SYMBOL(dmu_object_reclaim_dnsize); +EXPORT_SYMBOL(dmu_object_rm_spill); +EXPORT_SYMBOL(dmu_object_free); +EXPORT_SYMBOL(dmu_object_next); +EXPORT_SYMBOL(dmu_object_zapify); +EXPORT_SYMBOL(dmu_object_free_zapified); + +/* BEGIN CSTYLED */ +ZFS_MODULE_PARAM(zfs, , dmu_object_alloc_chunk_shift, INT, ZMOD_RW, + "CPU-specific allocator grabs 2^N objects at once"); +/* END CSTYLED */ |