mirror of
https://github.com/octoleo/restic.git
synced 2024-11-05 12:57:53 +00:00
f17ffa0283
Much simpler implementation that guarantees each required pack is downloaded only once (and hence does not need to manage pack cache). Also improves large file restore performance. Signed-off-by: Igor Fedorenko <igor@ifedorenko.com>
343 lines
9.5 KiB
Go
343 lines
9.5 KiB
Go
package restorer
|
|
|
|
import (
|
|
"context"
|
|
"os"
|
|
"path/filepath"
|
|
|
|
"github.com/restic/restic/internal/crypto"
|
|
"github.com/restic/restic/internal/errors"
|
|
|
|
"github.com/restic/restic/internal/debug"
|
|
"github.com/restic/restic/internal/fs"
|
|
"github.com/restic/restic/internal/restic"
|
|
)
|
|
|
|
// Restorer is used to restore a snapshot to a directory.
|
|
type Restorer struct {
|
|
repo restic.Repository
|
|
sn *restic.Snapshot
|
|
|
|
Error func(location string, err error) error
|
|
SelectFilter func(item string, dstpath string, node *restic.Node) (selectedForRestore bool, childMayBeSelected bool)
|
|
}
|
|
|
|
var restorerAbortOnAllErrors = func(location string, err error) error { return err }
|
|
|
|
// NewRestorer creates a restorer preloaded with the content from the snapshot id.
|
|
func NewRestorer(repo restic.Repository, id restic.ID) (*Restorer, error) {
|
|
r := &Restorer{
|
|
repo: repo,
|
|
Error: restorerAbortOnAllErrors,
|
|
SelectFilter: func(string, string, *restic.Node) (bool, bool) { return true, true },
|
|
}
|
|
|
|
var err error
|
|
|
|
r.sn, err = restic.LoadSnapshot(context.TODO(), repo, id)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
return r, nil
|
|
}
|
|
|
|
type treeVisitor struct {
|
|
enterDir func(node *restic.Node, target, location string) error
|
|
visitNode func(node *restic.Node, target, location string) error
|
|
leaveDir func(node *restic.Node, target, location string) error
|
|
}
|
|
|
|
// traverseTree traverses a tree from the repo and calls treeVisitor.
|
|
// target is the path in the file system, location within the snapshot.
|
|
func (res *Restorer) traverseTree(ctx context.Context, target, location string, treeID restic.ID, visitor treeVisitor) error {
|
|
debug.Log("%v %v %v", target, location, treeID)
|
|
tree, err := res.repo.LoadTree(ctx, treeID)
|
|
if err != nil {
|
|
debug.Log("error loading tree %v: %v", treeID, err)
|
|
return res.Error(location, err)
|
|
}
|
|
|
|
for _, node := range tree.Nodes {
|
|
|
|
// ensure that the node name does not contain anything that refers to a
|
|
// top-level directory.
|
|
nodeName := filepath.Base(filepath.Join(string(filepath.Separator), node.Name))
|
|
if nodeName != node.Name {
|
|
debug.Log("node %q has invalid name %q", node.Name, nodeName)
|
|
err := res.Error(location, errors.Errorf("invalid child node name %s", node.Name))
|
|
if err != nil {
|
|
return err
|
|
}
|
|
continue
|
|
}
|
|
|
|
nodeTarget := filepath.Join(target, nodeName)
|
|
nodeLocation := filepath.Join(location, nodeName)
|
|
|
|
if target == nodeTarget || !fs.HasPathPrefix(target, nodeTarget) {
|
|
debug.Log("target: %v %v", target, nodeTarget)
|
|
debug.Log("node %q has invalid target path %q", node.Name, nodeTarget)
|
|
err := res.Error(nodeLocation, errors.New("node has invalid path"))
|
|
if err != nil {
|
|
return err
|
|
}
|
|
continue
|
|
}
|
|
|
|
// sockets cannot be restored
|
|
if node.Type == "socket" {
|
|
continue
|
|
}
|
|
|
|
selectedForRestore, childMayBeSelected := res.SelectFilter(nodeLocation, nodeTarget, node)
|
|
debug.Log("SelectFilter returned %v %v", selectedForRestore, childMayBeSelected)
|
|
|
|
sanitizeError := func(err error) error {
|
|
if err != nil {
|
|
err = res.Error(nodeLocation, err)
|
|
}
|
|
return err
|
|
}
|
|
|
|
if node.Type == "dir" {
|
|
if node.Subtree == nil {
|
|
return errors.Errorf("Dir without subtree in tree %v", treeID.Str())
|
|
}
|
|
|
|
if selectedForRestore {
|
|
err = sanitizeError(visitor.enterDir(node, nodeTarget, nodeLocation))
|
|
if err != nil {
|
|
return err
|
|
}
|
|
}
|
|
|
|
if childMayBeSelected {
|
|
err = sanitizeError(res.traverseTree(ctx, nodeTarget, nodeLocation, *node.Subtree, visitor))
|
|
if err != nil {
|
|
return err
|
|
}
|
|
}
|
|
|
|
if selectedForRestore {
|
|
err = sanitizeError(visitor.leaveDir(node, nodeTarget, nodeLocation))
|
|
if err != nil {
|
|
return err
|
|
}
|
|
}
|
|
|
|
continue
|
|
}
|
|
|
|
if selectedForRestore {
|
|
err = sanitizeError(visitor.visitNode(node, nodeTarget, nodeLocation))
|
|
if err != nil {
|
|
return err
|
|
}
|
|
}
|
|
}
|
|
|
|
return nil
|
|
}
|
|
|
|
func (res *Restorer) restoreNodeTo(ctx context.Context, node *restic.Node, target, location string) error {
|
|
debug.Log("restoreNode %v %v %v", node.Name, target, location)
|
|
|
|
err := node.CreateAt(ctx, target, res.repo)
|
|
if err != nil {
|
|
debug.Log("node.CreateAt(%s) error %v", target, err)
|
|
}
|
|
if err == nil {
|
|
err = res.restoreNodeMetadataTo(node, target, location)
|
|
}
|
|
|
|
return err
|
|
}
|
|
|
|
func (res *Restorer) restoreNodeMetadataTo(node *restic.Node, target, location string) error {
|
|
debug.Log("restoreNodeMetadata %v %v %v", node.Name, target, location)
|
|
err := node.RestoreMetadata(target)
|
|
if err != nil {
|
|
debug.Log("node.RestoreMetadata(%s) error %v", target, err)
|
|
}
|
|
return err
|
|
}
|
|
|
|
func (res *Restorer) restoreHardlinkAt(node *restic.Node, target, path, location string) error {
|
|
if err := fs.Remove(path); !os.IsNotExist(err) {
|
|
return errors.Wrap(err, "RemoveCreateHardlink")
|
|
}
|
|
err := fs.Link(target, path)
|
|
if err != nil {
|
|
return errors.Wrap(err, "CreateHardlink")
|
|
}
|
|
// TODO investigate if hardlinks have separate metadata on any supported system
|
|
return res.restoreNodeMetadataTo(node, path, location)
|
|
}
|
|
|
|
func (res *Restorer) restoreEmptyFileAt(node *restic.Node, target, location string) error {
|
|
wr, err := os.OpenFile(target, os.O_CREATE|os.O_TRUNC|os.O_WRONLY, 0600)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
err = wr.Close()
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
return res.restoreNodeMetadataTo(node, target, location)
|
|
}
|
|
|
|
// RestoreTo creates the directories and files in the snapshot below dst.
|
|
// Before an item is created, res.Filter is called.
|
|
func (res *Restorer) RestoreTo(ctx context.Context, dst string) error {
|
|
var err error
|
|
if !filepath.IsAbs(dst) {
|
|
dst, err = filepath.Abs(dst)
|
|
if err != nil {
|
|
return errors.Wrap(err, "Abs")
|
|
}
|
|
}
|
|
|
|
restoreNodeMetadata := func(node *restic.Node, target, location string) error {
|
|
return res.restoreNodeMetadataTo(node, target, location)
|
|
}
|
|
noop := func(node *restic.Node, target, location string) error { return nil }
|
|
|
|
idx := restic.NewHardlinkIndex()
|
|
|
|
filerestorer := newFileRestorer(dst, res.repo.Backend().Load, res.repo.Key(), res.repo.Index().Lookup)
|
|
|
|
// first tree pass: create directories and collect all files to restore
|
|
err = res.traverseTree(ctx, dst, string(filepath.Separator), *res.sn.Tree, treeVisitor{
|
|
enterDir: func(node *restic.Node, target, location string) error {
|
|
// create dir with default permissions
|
|
// #leaveDir restores dir metadata after visiting all children
|
|
return fs.MkdirAll(target, 0700)
|
|
},
|
|
|
|
visitNode: func(node *restic.Node, target, location string) error {
|
|
// create parent dir with default permissions
|
|
// second pass #leaveDir restores dir metadata after visiting/restoring all children
|
|
err := fs.MkdirAll(filepath.Dir(target), 0700)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
if node.Type != "file" {
|
|
return nil
|
|
}
|
|
|
|
if node.Size == 0 {
|
|
return nil // deal with empty files later
|
|
}
|
|
|
|
if node.Links > 1 {
|
|
if idx.Has(node.Inode, node.DeviceID) {
|
|
return nil
|
|
}
|
|
idx.Add(node.Inode, node.DeviceID, location)
|
|
}
|
|
|
|
filerestorer.addFile(location, node.Content)
|
|
|
|
return nil
|
|
},
|
|
leaveDir: noop,
|
|
})
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
err = filerestorer.restoreFiles(ctx)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
// second tree pass: restore special files and filesystem metadata
|
|
return res.traverseTree(ctx, dst, string(filepath.Separator), *res.sn.Tree, treeVisitor{
|
|
enterDir: noop,
|
|
visitNode: func(node *restic.Node, target, location string) error {
|
|
if node.Type != "file" {
|
|
return res.restoreNodeTo(ctx, node, target, location)
|
|
}
|
|
|
|
// create empty files, but not hardlinks to empty files
|
|
if node.Size == 0 && (node.Links < 2 || !idx.Has(node.Inode, node.DeviceID)) {
|
|
if node.Links > 1 {
|
|
idx.Add(node.Inode, node.DeviceID, location)
|
|
}
|
|
return res.restoreEmptyFileAt(node, target, location)
|
|
}
|
|
|
|
if idx.Has(node.Inode, node.DeviceID) && idx.GetFilename(node.Inode, node.DeviceID) != location {
|
|
return res.restoreHardlinkAt(node, filerestorer.targetPath(idx.GetFilename(node.Inode, node.DeviceID)), target, location)
|
|
}
|
|
|
|
return res.restoreNodeMetadataTo(node, target, location)
|
|
},
|
|
leaveDir: restoreNodeMetadata,
|
|
})
|
|
}
|
|
|
|
// Snapshot returns the snapshot this restorer is configured to use.
|
|
func (res *Restorer) Snapshot() *restic.Snapshot {
|
|
return res.sn
|
|
}
|
|
|
|
// VerifyFiles reads all snapshot files and verifies their contents
|
|
func (res *Restorer) VerifyFiles(ctx context.Context, dst string) (int, error) {
|
|
// TODO multithreaded?
|
|
|
|
count := 0
|
|
err := res.traverseTree(ctx, dst, string(filepath.Separator), *res.sn.Tree, treeVisitor{
|
|
enterDir: func(node *restic.Node, target, location string) error { return nil },
|
|
visitNode: func(node *restic.Node, target, location string) error {
|
|
if node.Type != "file" {
|
|
return nil
|
|
}
|
|
|
|
count++
|
|
stat, err := os.Stat(target)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
if int64(node.Size) != stat.Size() {
|
|
return errors.Errorf("Invalid file size: expected %d got %d", node.Size, stat.Size())
|
|
}
|
|
|
|
file, err := os.Open(target)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
offset := int64(0)
|
|
for _, blobID := range node.Content {
|
|
blobs, _ := res.repo.Index().Lookup(blobID, restic.DataBlob)
|
|
length := blobs[0].Length - uint(crypto.Extension)
|
|
buf := make([]byte, length) // TODO do I want to reuse the buffer somehow?
|
|
_, err = file.ReadAt(buf, offset)
|
|
if err != nil {
|
|
_ = file.Close()
|
|
return err
|
|
}
|
|
if !blobID.Equal(restic.Hash(buf)) {
|
|
_ = file.Close()
|
|
return errors.Errorf("Unexpected contents starting at offset %d", offset)
|
|
}
|
|
offset += int64(length)
|
|
}
|
|
|
|
err = file.Close()
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
return nil
|
|
},
|
|
leaveDir: func(node *restic.Node, target, location string) error { return nil },
|
|
})
|
|
|
|
return count, err
|
|
}
|