From 753c38392ddff9d3cf140bb4d28f3bfba52c92d2 Mon Sep 17 00:00:00 2001 From: Matthew Ahrens Date: Sun, 23 Dec 2012 15:57:14 -0800 Subject: [PATCH] Illumos #3104: eliminate empty bpobjs 3104 eliminate empty bpobjs Reviewed by: George Wilson Reviewed by: Adam Leventhal Reviewed by: Christopher Siden Reviewed by: Garrett D'Amore Approved by: Eric Schrock References: illumos/illumos-gate@f17457368189aa911f774c38c1f21875a568bdca illumos changeset: 13782:8f78aae28a63 https://www.illumos.org/issues/3104 Ported-by: Brian Behlendorf --- include/sys/bpobj.h | 3 ++ include/sys/dmu.h | 1 + include/sys/dsl_pool.h | 1 + include/sys/zap.h | 2 ++ include/zfeature_common.h | 1 + man/man5/zpool-features.5 | 28 +++++++++++++++++ module/zfs/bpobj.c | 58 +++++++++++++++++++++++++++++++++++- module/zfs/dsl_deadlist.c | 54 +++++++++++++++++++++++++++------ module/zfs/dsl_pool.c | 9 ++++++ module/zfs/zap.c | 10 +++++++ module/zfs/zfeature.c | 7 ++++- module/zfs/zfeature_common.c | 3 ++ 12 files changed, 166 insertions(+), 11 deletions(-) diff --git a/include/sys/bpobj.h b/include/sys/bpobj.h index 3771a9541..af975c734 100644 --- a/include/sys/bpobj.h +++ b/include/sys/bpobj.h @@ -20,6 +20,7 @@ */ /* * Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved. + * Copyright (c) 2012 by Delphix. All rights reserved. */ #ifndef _SYS_BPOBJ_H @@ -67,7 +68,9 @@ typedef struct bpobj { typedef int bpobj_itor_t(void *arg, const blkptr_t *bp, dmu_tx_t *tx); uint64_t bpobj_alloc(objset_t *mos, int blocksize, dmu_tx_t *tx); +uint64_t bpobj_alloc_empty(objset_t *os, int blocksize, dmu_tx_t *tx); void bpobj_free(objset_t *os, uint64_t obj, dmu_tx_t *tx); +void bpobj_decr_empty(objset_t *os, dmu_tx_t *tx); int bpobj_open(bpobj_t *bpo, objset_t *mos, uint64_t object); void bpobj_close(bpobj_t *bpo); diff --git a/include/sys/dmu.h b/include/sys/dmu.h index ce3169731..7fc876be7 100644 --- a/include/sys/dmu.h +++ b/include/sys/dmu.h @@ -309,6 +309,7 @@ typedef void dmu_buf_evict_func_t(struct dmu_buf *db, void *user_ptr); #define DMU_POOL_SCAN "scan" #define DMU_POOL_FREE_BPOBJ "free_bpobj" #define DMU_POOL_BPTREE_OBJ "bptree_obj" +#define DMU_POOL_EMPTY_BPOBJ "empty_bpobj" /* * Allocate an object from this objset. The range of object numbers diff --git a/include/sys/dsl_pool.h b/include/sys/dsl_pool.h index 61c91f06c..ff5df1414 100644 --- a/include/sys/dsl_pool.h +++ b/include/sys/dsl_pool.h @@ -96,6 +96,7 @@ typedef struct dsl_pool { uint64_t dp_tmp_userrefs_obj; bpobj_t dp_free_bpobj; uint64_t dp_bptree_obj; + uint64_t dp_empty_bpobj; struct dsl_scan *dp_scan; diff --git a/include/sys/zap.h b/include/sys/zap.h index 4d7b31559..092669c8b 100644 --- a/include/sys/zap.h +++ b/include/sys/zap.h @@ -300,6 +300,8 @@ int zap_increment_int(objset_t *os, uint64_t obj, uint64_t key, int64_t delta, /* Here the key is an int and the value is a different int. */ int zap_add_int_key(objset_t *os, uint64_t obj, uint64_t key, uint64_t value, dmu_tx_t *tx); +int zap_update_int_key(objset_t *os, uint64_t obj, + uint64_t key, uint64_t value, dmu_tx_t *tx); int zap_lookup_int_key(objset_t *os, uint64_t obj, uint64_t key, uint64_t *valuep); diff --git a/include/zfeature_common.h b/include/zfeature_common.h index 27f8f00a0..cb1d02fd7 100644 --- a/include/zfeature_common.h +++ b/include/zfeature_common.h @@ -51,6 +51,7 @@ typedef int (zfeature_func_t)(zfeature_info_t *fi, void *arg); typedef enum spa_feature { SPA_FEATURE_ASYNC_DESTROY, + SPA_FEATURE_EMPTY_BPOBJ, SPA_FEATURES } spa_feature_t; diff --git a/man/man5/zpool-features.5 b/man/man5/zpool-features.5 index 3c1930c35..0ab179ef7 100644 --- a/man/man5/zpool-features.5 +++ b/man/man5/zpool-features.5 @@ -169,5 +169,33 @@ through the \fBfreeing\fR property. This feature is only \fBactive\fR while \fBfreeing\fR is non\-zero. .RE + +.sp +.ne 2 +.na +\fB\fBempty_bpobj\fR\fR +.ad +.RS 4n +.TS +l l . +GUID com.delphix:empty_bpobj +READ\-ONLY COMPATIBLE yes +DEPENDENCIES none +.TE + +This feature increases the performance of creating and using a large +number of snapshots of a single filesystem or volume, and also reduces +the disk space required. + +When there are many snapshots, each snapshot uses many Block Pointer +Objects (bpobj's) to track blocks associated with that snapshot. +However, in common use cases, most of these bpobj's are empty. This +feature allows us to create each bpobj on-demand, thus eliminating the +empty bpobjs. + +This feature is \fBactive\fR while there are any filesystems, volumes, +or snapshots which were created after enabling this feature. +.RE + .SH "SEE ALSO" \fBzpool\fR(1M) diff --git a/module/zfs/bpobj.c b/module/zfs/bpobj.c index 022921c66..d5f8d4072 100644 --- a/module/zfs/bpobj.c +++ b/module/zfs/bpobj.c @@ -20,13 +20,61 @@ */ /* * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. - * Copyright (c) 2011 by Delphix. All rights reserved. + * Copyright (c) 2012 by Delphix. All rights reserved. */ #include #include #include #include +#include +#include + +/* + * Return an empty bpobj, preferably the empty dummy one (dp_empty_bpobj). + */ +uint64_t +bpobj_alloc_empty(objset_t *os, int blocksize, dmu_tx_t *tx) +{ + zfeature_info_t *empty_bpobj_feat = + &spa_feature_table[SPA_FEATURE_EMPTY_BPOBJ]; + spa_t *spa = dmu_objset_spa(os); + dsl_pool_t *dp = dmu_objset_pool(os); + + if (spa_feature_is_enabled(spa, empty_bpobj_feat)) { + if (!spa_feature_is_active(spa, empty_bpobj_feat)) { + ASSERT3U(dp->dp_empty_bpobj, ==, 0); + dp->dp_empty_bpobj = + bpobj_alloc(os, SPA_MAXBLOCKSIZE, tx); + VERIFY(zap_add(os, + DMU_POOL_DIRECTORY_OBJECT, + DMU_POOL_EMPTY_BPOBJ, sizeof (uint64_t), 1, + &dp->dp_empty_bpobj, tx) == 0); + } + spa_feature_incr(spa, empty_bpobj_feat, tx); + ASSERT(dp->dp_empty_bpobj != 0); + return (dp->dp_empty_bpobj); + } else { + return (bpobj_alloc(os, blocksize, tx)); + } +} + +void +bpobj_decr_empty(objset_t *os, dmu_tx_t *tx) +{ + zfeature_info_t *empty_bpobj_feat = + &spa_feature_table[SPA_FEATURE_EMPTY_BPOBJ]; + dsl_pool_t *dp = dmu_objset_pool(os); + + spa_feature_decr(dmu_objset_spa(os), empty_bpobj_feat, tx); + if (!spa_feature_is_active(dmu_objset_spa(os), empty_bpobj_feat)) { + VERIFY3U(0, ==, zap_remove(dp->dp_meta_objset, + DMU_POOL_DIRECTORY_OBJECT, + DMU_POOL_EMPTY_BPOBJ, tx)); + VERIFY3U(0, ==, dmu_object_free(os, dp->dp_empty_bpobj, tx)); + dp->dp_empty_bpobj = 0; + } +} uint64_t bpobj_alloc(objset_t *os, int blocksize, dmu_tx_t *tx) @@ -53,6 +101,7 @@ bpobj_free(objset_t *os, uint64_t obj, dmu_tx_t *tx) int epb; dmu_buf_t *dbuf = NULL; + ASSERT(obj != dmu_objset_pool(os)->dp_empty_bpobj); VERIFY3U(0, ==, bpobj_open(&bpo, os, obj)); mutex_enter(&bpo.bpo_lock); @@ -320,6 +369,12 @@ bpobj_enqueue_subobj(bpobj_t *bpo, uint64_t subobj, dmu_tx_t *tx) ASSERT(bpo->bpo_havesubobj); ASSERT(bpo->bpo_havecomp); + ASSERT(bpo->bpo_object != dmu_objset_pool(bpo->bpo_os)->dp_empty_bpobj); + + if (subobj == dmu_objset_pool(bpo->bpo_os)->dp_empty_bpobj) { + bpobj_decr_empty(bpo->bpo_os, tx); + return; + } VERIFY3U(0, ==, bpobj_open(&subbpo, bpo->bpo_os, subobj)); VERIFY3U(0, ==, bpobj_space(&subbpo, &used, &comp, &uncomp)); @@ -388,6 +443,7 @@ bpobj_enqueue(bpobj_t *bpo, const blkptr_t *bp, dmu_tx_t *tx) blkptr_t *bparray; ASSERT(!BP_IS_HOLE(bp)); + ASSERT(bpo->bpo_object != dmu_objset_pool(bpo->bpo_os)->dp_empty_bpobj); /* We never need the fill count. */ stored_bp.blk_fill = 0; diff --git a/module/zfs/dsl_deadlist.c b/module/zfs/dsl_deadlist.c index 1e89a68d7..909b5f8fc 100644 --- a/module/zfs/dsl_deadlist.c +++ b/module/zfs/dsl_deadlist.c @@ -20,7 +20,7 @@ */ /* * Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved. - * Copyright (c) 2011 by Delphix. All rights reserved. + * Copyright (c) 2012 by Delphix. All rights reserved. */ #include @@ -165,12 +165,49 @@ dsl_deadlist_free(objset_t *os, uint64_t dlobj, dmu_tx_t *tx) for (zap_cursor_init(&zc, os, dlobj); zap_cursor_retrieve(&zc, &za) == 0; - zap_cursor_advance(&zc)) - bpobj_free(os, za.za_first_integer, tx); + zap_cursor_advance(&zc)) { + uint64_t obj = za.za_first_integer; + if (obj == dmu_objset_pool(os)->dp_empty_bpobj) + bpobj_decr_empty(os, tx); + else + bpobj_free(os, obj, tx); + } zap_cursor_fini(&zc); VERIFY3U(0, ==, dmu_object_free(os, dlobj, tx)); } +static void +dle_enqueue(dsl_deadlist_t *dl, dsl_deadlist_entry_t *dle, + const blkptr_t *bp, dmu_tx_t *tx) +{ + if (dle->dle_bpobj.bpo_object == + dmu_objset_pool(dl->dl_os)->dp_empty_bpobj) { + uint64_t obj = bpobj_alloc(dl->dl_os, SPA_MAXBLOCKSIZE, tx); + bpobj_close(&dle->dle_bpobj); + bpobj_decr_empty(dl->dl_os, tx); + VERIFY3U(0, ==, bpobj_open(&dle->dle_bpobj, dl->dl_os, obj)); + VERIFY3U(0, ==, zap_update_int_key(dl->dl_os, dl->dl_object, + dle->dle_mintxg, obj, tx)); + } + bpobj_enqueue(&dle->dle_bpobj, bp, tx); +} + +static void +dle_enqueue_subobj(dsl_deadlist_t *dl, dsl_deadlist_entry_t *dle, + uint64_t obj, dmu_tx_t *tx) +{ + if (dle->dle_bpobj.bpo_object != + dmu_objset_pool(dl->dl_os)->dp_empty_bpobj) { + bpobj_enqueue_subobj(&dle->dle_bpobj, obj, tx); + } else { + bpobj_close(&dle->dle_bpobj); + bpobj_decr_empty(dl->dl_os, tx); + VERIFY3U(0, ==, bpobj_open(&dle->dle_bpobj, dl->dl_os, obj)); + VERIFY3U(0, ==, zap_update_int_key(dl->dl_os, dl->dl_object, + dle->dle_mintxg, obj, tx)); + } +} + void dsl_deadlist_insert(dsl_deadlist_t *dl, const blkptr_t *bp, dmu_tx_t *tx) { @@ -199,7 +236,7 @@ dsl_deadlist_insert(dsl_deadlist_t *dl, const blkptr_t *bp, dmu_tx_t *tx) dle = avl_nearest(&dl->dl_tree, where, AVL_BEFORE); else dle = AVL_PREV(&dl->dl_tree, dle); - bpobj_enqueue(&dle->dle_bpobj, bp, tx); + dle_enqueue(dl, dle, bp, tx); } /* @@ -219,7 +256,7 @@ dsl_deadlist_add_key(dsl_deadlist_t *dl, uint64_t mintxg, dmu_tx_t *tx) dle = kmem_alloc(sizeof (*dle), KM_PUSHPAGE); dle->dle_mintxg = mintxg; - obj = bpobj_alloc(dl->dl_os, SPA_MAXBLOCKSIZE, tx); + obj = bpobj_alloc_empty(dl->dl_os, SPA_MAXBLOCKSIZE, tx); VERIFY3U(0, ==, bpobj_open(&dle->dle_bpobj, dl->dl_os, obj)); avl_add(&dl->dl_tree, dle); @@ -245,8 +282,7 @@ dsl_deadlist_remove_key(dsl_deadlist_t *dl, uint64_t mintxg, dmu_tx_t *tx) dle = avl_find(&dl->dl_tree, &dle_tofind, NULL); dle_prev = AVL_PREV(&dl->dl_tree, dle); - bpobj_enqueue_subobj(&dle_prev->dle_bpobj, - dle->dle_bpobj.bpo_object, tx); + dle_enqueue_subobj(dl, dle_prev, dle->dle_bpobj.bpo_object, tx); avl_remove(&dl->dl_tree, dle); bpobj_close(&dle->dle_bpobj); @@ -304,7 +340,7 @@ dsl_deadlist_clone(dsl_deadlist_t *dl, uint64_t maxtxg, if (dle->dle_mintxg >= maxtxg) break; - obj = bpobj_alloc(dl->dl_os, SPA_MAXBLOCKSIZE, tx); + obj = bpobj_alloc_empty(dl->dl_os, SPA_MAXBLOCKSIZE, tx); VERIFY3U(0, ==, zap_add_int_key(dl->dl_os, newobj, dle->dle_mintxg, obj, tx)); } @@ -402,7 +438,7 @@ dsl_deadlist_insert_bpobj(dsl_deadlist_t *dl, uint64_t obj, uint64_t birth, dle = avl_find(&dl->dl_tree, &dle_tofind, &where); if (dle == NULL) dle = avl_nearest(&dl->dl_tree, where, AVL_BEFORE); - bpobj_enqueue_subobj(&dle->dle_bpobj, obj, tx); + dle_enqueue_subobj(dl, dle, obj, tx); } static int diff --git a/module/zfs/dsl_pool.c b/module/zfs/dsl_pool.c index 089a7f092..704f034e9 100644 --- a/module/zfs/dsl_pool.c +++ b/module/zfs/dsl_pool.c @@ -322,6 +322,15 @@ dsl_pool_open(dsl_pool_t *dp) goto out; } + if (spa_feature_is_active(dp->dp_spa, + &spa_feature_table[SPA_FEATURE_EMPTY_BPOBJ])) { + err = zap_lookup(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT, + DMU_POOL_EMPTY_BPOBJ, sizeof (uint64_t), 1, + &dp->dp_empty_bpobj); + if (err != 0) + goto out; + } + err = zap_lookup(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_TMP_USERREFS, sizeof (uint64_t), 1, &dp->dp_tmp_userrefs_obj); diff --git a/module/zfs/zap.c b/module/zfs/zap.c index 59f62fa3a..fd3021be6 100644 --- a/module/zfs/zap.c +++ b/module/zfs/zap.c @@ -1093,6 +1093,16 @@ zap_add_int_key(objset_t *os, uint64_t obj, return (zap_add(os, obj, name, 8, 1, &value, tx)); } +int +zap_update_int_key(objset_t *os, uint64_t obj, + uint64_t key, uint64_t value, dmu_tx_t *tx) +{ + char name[20]; + + (void) snprintf(name, sizeof (name), "%llx", (longlong_t)key); + return (zap_update(os, obj, name, 8, 1, &value, tx)); +} + int zap_lookup_int_key(objset_t *os, uint64_t obj, uint64_t key, uint64_t *valuep) { diff --git a/module/zfs/zfeature.c b/module/zfs/zfeature.c index 24ff18fc3..c09b32d17 100644 --- a/module/zfs/zfeature.c +++ b/module/zfs/zfeature.c @@ -229,7 +229,12 @@ feature_get_refcount(objset_t *os, uint64_t read_obj, uint64_t write_obj, uint64_t refcount; uint64_t zapobj = feature->fi_can_readonly ? write_obj : read_obj; - ASSERT(0 != zapobj); + /* + * If the pool is currently being created, the feature objects may not + * have been allocated yet. Act as though all features are disabled. + */ + if (zapobj == 0) + return (ENOTSUP); err = zap_lookup(os, zapobj, feature->fi_guid, sizeof (uint64_t), 1, &refcount); diff --git a/module/zfs/zfeature_common.c b/module/zfs/zfeature_common.c index 33d15133e..40066991b 100644 --- a/module/zfs/zfeature_common.c +++ b/module/zfs/zfeature_common.c @@ -157,4 +157,7 @@ zpool_feature_init(void) zfeature_register(SPA_FEATURE_ASYNC_DESTROY, "com.delphix:async_destroy", "async_destroy", "Destroy filesystems asynchronously.", B_TRUE, B_FALSE, NULL); + zfeature_register(SPA_FEATURE_EMPTY_BPOBJ, + "com.delphix:empty_bpobj", "empty_bpobj", + "Snapshots use less space.", B_TRUE, B_FALSE, NULL); }