// +build !openbsd // +build !windows package fuse import ( "restic/errors" "restic" "restic/debug" scontext "context" "bazil.org/fuse" "bazil.org/fuse/fs" "golang.org/x/net/context" ) // The default block size to report in stat const blockSize = 512 // Statically ensure that *file implements the given interface var _ = fs.HandleReader(&file{}) var _ = fs.HandleReleaser(&file{}) // BlobLoader is an abstracted repository with a reduced set of methods used // for fuse operations. type BlobLoader interface { LookupBlobSize(restic.ID, restic.BlobType) (uint, error) LoadBlob(scontext.Context, restic.BlobType, restic.ID, []byte) (int, error) } type file struct { repo BlobLoader node *restic.Node ownerIsRoot bool sizes []int blobs [][]byte } func newFile(repo BlobLoader, node *restic.Node, ownerIsRoot bool, blobsize *BlobSizeCache) (fusefile *file, err error) { debug.Log("create new file for %v with %d blobs", node.Name, len(node.Content)) var bytes uint64 sizes := make([]int, len(node.Content)) for i, id := range node.Content { size, ok := blobsize.Lookup(id) if !ok { size, err = repo.LookupBlobSize(id, restic.DataBlob) if err != nil { return nil, err } } sizes[i] = int(size) bytes += uint64(size) } if bytes != node.Size { debug.Log("sizes do not match: node.Size %v != size %v, using real size", node.Size, bytes) node.Size = bytes } return &file{ repo: repo, node: node, sizes: sizes, blobs: make([][]byte, len(node.Content)), ownerIsRoot: ownerIsRoot, }, nil } func (f *file) Attr(ctx context.Context, a *fuse.Attr) error { debug.Log("Attr(%v)", f.node.Name) a.Inode = f.node.Inode a.Mode = f.node.Mode a.Size = f.node.Size a.Blocks = (f.node.Size / blockSize) + 1 a.BlockSize = blockSize a.Nlink = uint32(f.node.Links) if !f.ownerIsRoot { a.Uid = f.node.UID a.Gid = f.node.GID } a.Atime = f.node.AccessTime a.Ctime = f.node.ChangeTime a.Mtime = f.node.ModTime return nil } func (f *file) getBlobAt(ctx context.Context, i int) (blob []byte, err error) { debug.Log("getBlobAt(%v, %v)", f.node.Name, i) if f.blobs[i] != nil { return f.blobs[i], nil } // release earlier blobs for j := 0; j < i; j++ { f.blobs[j] = nil } buf := restic.NewBlobBuffer(f.sizes[i]) n, err := f.repo.LoadBlob(ctx, restic.DataBlob, f.node.Content[i], buf) if err != nil { debug.Log("LoadBlob(%v, %v) failed: %v", f.node.Name, f.node.Content[i], err) return nil, err } f.blobs[i] = buf[:n] return buf[:n], nil } func (f *file) Read(ctx context.Context, req *fuse.ReadRequest, resp *fuse.ReadResponse) error { debug.Log("Read(%v, %v, %v), file size %v", f.node.Name, req.Size, req.Offset, f.node.Size) offset := req.Offset if uint64(offset) > f.node.Size { debug.Log("Read(%v): offset is greater than file size: %v > %v", f.node.Name, req.Offset, f.node.Size) return errors.New("offset greater than files size") } // handle special case: file is empty if f.node.Size == 0 { resp.Data = resp.Data[:0] return nil } // Skip blobs before the offset startContent := 0 for offset > int64(f.sizes[startContent]) { offset -= int64(f.sizes[startContent]) startContent++ } dst := resp.Data[0:req.Size] readBytes := 0 remainingBytes := req.Size for i := startContent; remainingBytes > 0 && i < len(f.sizes); i++ { blob, err := f.getBlobAt(ctx, i) if err != nil { return err } if offset > 0 { blob = blob[offset:] offset = 0 } copied := copy(dst, blob) remainingBytes -= copied readBytes += copied dst = dst[copied:] } resp.Data = resp.Data[:readBytes] return nil } func (f *file) Release(ctx context.Context, req *fuse.ReleaseRequest) error { for i := range f.blobs { f.blobs[i] = nil } return nil } func (f *file) Listxattr(ctx context.Context, req *fuse.ListxattrRequest, resp *fuse.ListxattrResponse) error { debug.Log("Listxattr(%v, %v)", f.node.Name, req.Size) for _, attr := range f.node.ExtendedAttributes { resp.Append(attr.Name) } return nil } func (f *file) Getxattr(ctx context.Context, req *fuse.GetxattrRequest, resp *fuse.GetxattrResponse) error { debug.Log("Getxattr(%v, %v, %v)", f.node.Name, req.Name, req.Size) attrval := f.node.GetExtendedAttribute(req.Name) if attrval != nil { resp.Xattr = attrval return nil } return fuse.ErrNoXattr }