From 94aa0ec3e9f7145cdf177ad6f6d3d8b7d5bdbef7 Mon Sep 17 00:00:00 2001 From: Luke Shumaker Date: Wed, 29 Mar 2023 10:00:18 -0600 Subject: btrfstree: Change the NodeSource API so that it can do caching --- lib/btrfs/btrfstree/btree.go | 3 ++- lib/btrfs/btrfstree/btree_tree.go | 4 +-- lib/btrfs/btrfstree/types_node.go | 4 ++- lib/btrfs/io2_lv.go | 3 +++ lib/btrfs/io3_btree.go | 57 +++++++++++++++++++++++++++++++-------- 5 files changed, 56 insertions(+), 15 deletions(-) (limited to 'lib/btrfs') diff --git a/lib/btrfs/btrfstree/btree.go b/lib/btrfs/btrfstree/btree.go index dde485a..4f5d21b 100644 --- a/lib/btrfs/btrfstree/btree.go +++ b/lib/btrfs/btrfstree/btree.go @@ -97,5 +97,6 @@ func (e *TreeError) Error() string { type NodeSource interface { Superblock() (*Superblock, error) - ReadNode(ctx context.Context, addr btrfsvol.LogicalAddr, exp NodeExpectations) (*Node, error) + AcquireNode(ctx context.Context, addr btrfsvol.LogicalAddr, exp NodeExpectations) (*Node, error) + ReleaseNode(*Node) } diff --git a/lib/btrfs/btrfstree/btree_tree.go b/lib/btrfs/btrfstree/btree_tree.go index a6311f9..86eab11 100644 --- a/lib/btrfs/btrfstree/btree_tree.go +++ b/lib/btrfs/btrfstree/btree_tree.go @@ -46,8 +46,8 @@ func (tree *RawTree) walk(ctx context.Context, path Path, cbs TreeWalkHandler) { if !ok { return } - node, err := tree.Forrest.NodeSource.ReadNode(ctx, nodeAddr, nodeExp) - defer node.Free() + node, err := tree.Forrest.NodeSource.AcquireNode(ctx, nodeAddr, nodeExp) + defer tree.Forrest.NodeSource.ReleaseNode(node) if ctx.Err() != nil { return } diff --git a/lib/btrfs/btrfstree/types_node.go b/lib/btrfs/btrfstree/types_node.go index 082be2c..e29431f 100644 --- a/lib/btrfs/btrfstree/types_node.go +++ b/lib/btrfs/btrfstree/types_node.go @@ -308,7 +308,9 @@ type ItemHeader struct { var itemPool containers.SlicePool[Item] -func (node *Node) Free() { +// RawFree is for low-level use by caches; don't use .RawFree, use +// ReleaseNode. +func (node *Node) RawFree() { if node == nil { return } diff --git a/lib/btrfs/io2_lv.go b/lib/btrfs/io2_lv.go index 03b2107..72e97f3 100644 --- a/lib/btrfs/io2_lv.go +++ b/lib/btrfs/io2_lv.go @@ -16,6 +16,7 @@ import ( "git.lukeshu.com/btrfs-progs-ng/lib/btrfs/btrfsprim" "git.lukeshu.com/btrfs-progs-ng/lib/btrfs/btrfstree" "git.lukeshu.com/btrfs-progs-ng/lib/btrfs/btrfsvol" + "git.lukeshu.com/btrfs-progs-ng/lib/containers" "git.lukeshu.com/btrfs-progs-ng/lib/diskio" ) @@ -27,6 +28,8 @@ type FS struct { cacheSuperblocks []*diskio.Ref[btrfsvol.PhysicalAddr, btrfstree.Superblock] cacheSuperblock *btrfstree.Superblock + cacheNodes containers.Cache[btrfsvol.LogicalAddr, nodeCacheEntry] + cacheObjID2All map[btrfsprim.ObjID]treeInfo cacheUUID2ObjID map[btrfsprim.UUID]btrfsprim.ObjID } diff --git a/lib/btrfs/io3_btree.go b/lib/btrfs/io3_btree.go index 4d1ebe3..8aa485f 100644 --- a/lib/btrfs/io3_btree.go +++ b/lib/btrfs/io3_btree.go @@ -12,6 +12,8 @@ import ( "git.lukeshu.com/btrfs-progs-ng/lib/btrfs/btrfsprim" "git.lukeshu.com/btrfs-progs-ng/lib/btrfs/btrfstree" "git.lukeshu.com/btrfs-progs-ng/lib/btrfs/btrfsvol" + "git.lukeshu.com/btrfs-progs-ng/lib/containers" + "git.lukeshu.com/btrfs-progs-ng/lib/textui" ) // This file is ordered from low-level to high-level. @@ -80,23 +82,56 @@ var _ btrfstree.NodeFile = (*FS)(nil) // btrfstree.NodeSource //////////////////////////////////////////////////////// -// ReadNode implements btrfstree.NodeSource. -func (fs *FS) ReadNode(_ context.Context, addr btrfsvol.LogicalAddr, exp btrfstree.NodeExpectations) (*btrfstree.Node, error) { - sb, err := fs.Superblock() - if err != nil { - return nil, fmt.Errorf("btrfs.FS.ReadNode: %w", err) +type nodeCacheEntry struct { + node *btrfstree.Node + err error +} + +// AcquireNode implements btrfstree.NodeSource. +func (fs *FS) AcquireNode(ctx context.Context, addr btrfsvol.LogicalAddr, exp btrfstree.NodeExpectations) (*btrfstree.Node, error) { + if fs.cacheNodes == nil { + fs.cacheNodes = containers.NewARCache[btrfsvol.LogicalAddr, nodeCacheEntry]( + textui.Tunable(4*(btrfstree.MaxLevel+1)), + containers.SourceFunc[btrfsvol.LogicalAddr, nodeCacheEntry](fs.readNode), + ) } - node, err := btrfstree.ReadNode[btrfsvol.LogicalAddr](fs, *sb, addr) - if err != nil { - return node, err + nodeEntry := fs.cacheNodes.Acquire(ctx, addr) + if nodeEntry.err != nil { + err := nodeEntry.err + fs.cacheNodes.Release(addr) + return nil, err } - if err := exp.Check(node); err != nil { - return node, fmt.Errorf("btrfstree.ReadNode: node@%v: %w", addr, err) // fmt.Errorf("btrfs.FS.ReadNode: node@%v: %w", addr, err) + if nodeEntry.node != nil { + if err := exp.Check(nodeEntry.node); err != nil { + fs.cacheNodes.Release(addr) + return nil, fmt.Errorf("btrfstree.ReadNode: node@%v: %w", addr, err) // fmt.Errorf("btrfs.FS.AcquireNode: node@%v: %w", addr, err) + } + } + + return nodeEntry.node, nil +} + +// ReleaseNode implements btrfstree.NodeSource. +func (fs *FS) ReleaseNode(node *btrfstree.Node) { + if node == nil { + return + } + fs.cacheNodes.Release(node.Head.Addr) +} + +func (fs *FS) readNode(_ context.Context, addr btrfsvol.LogicalAddr, nodeEntry *nodeCacheEntry) { + nodeEntry.node.RawFree() + nodeEntry.node = nil + + sb, err := fs.Superblock() + if err != nil { + nodeEntry.err = err + return } - return node, nil + nodeEntry.node, nodeEntry.err = btrfstree.ReadNode[btrfsvol.LogicalAddr](fs, *sb, addr) } var _ btrfstree.NodeSource = (*FS)(nil) -- cgit v1.2.3-54-g00ecf