/
fuse.go
119 lines (108 loc) · 2.56 KB
/
fuse.go
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package snap
import (
"fmt"
"io"
"os"
"syscall"
"bazil.org/bazil/cas/blobs"
"bazil.org/bazil/cas/chunks"
"bazil.org/bazil/fs/readonly"
"bazil.org/bazil/fs/snap/wire"
"bazil.org/bazil/util/env"
"bazil.org/fuse"
fusefs "bazil.org/fuse/fs"
"golang.org/x/net/context"
)
// Serve this snapshot with FUSE, with this object store.
func Open(chunkStore chunks.Store, de *wire.Dirent) (fusefs.Node, error) {
switch {
case de.File != nil:
manifest, err := de.File.Manifest.ToBlob("file")
if err != nil {
return nil, err
}
child, err := readonly.NewFile(chunkStore, manifest)
if err != nil {
return nil, fmt.Errorf("snap file open error: %v", err)
}
return child, nil
case de.Dir != nil:
manifest, err := de.Dir.Manifest.ToBlob("dir")
if err != nil {
return nil, err
}
blob, err := blobs.Open(chunkStore, manifest)
if err != nil {
return nil, err
}
child := fuseDir{
chunkStore: chunkStore,
blob: blob,
align: de.Dir.Align,
}
return child, nil
default:
return nil, fmt.Errorf("unknown entry in tree, %v", de)
}
}
type fuseDir struct {
chunkStore chunks.Store
blob *blobs.Blob
align uint32
}
var _ fusefs.Node = fuseDir{}
var _ fusefs.NodeStringLookuper = fuseDir{}
var _ fusefs.NodeCreater = fuseDir{}
var _ fusefs.Handle = fuseDir{}
var _ fusefs.HandleReadDirAller = fuseDir{}
func (d fuseDir) Attr(ctx context.Context, a *fuse.Attr) error {
a.Mode = os.ModeDir | 0555
a.Uid = env.MyUID
a.Gid = env.MyGID
return nil
}
func (d fuseDir) Lookup(ctx context.Context, name string) (fusefs.Node, error) {
r, err := NewReader(d.blob.IO(ctx), d.align)
if err != nil {
return nil, err
}
de, err := r.Lookup(name)
if err != nil {
if os.IsNotExist(err) {
return nil, fuse.ENOENT
}
return nil, fmt.Errorf("snap lookup error: %v", err)
}
return Open(d.chunkStore, de)
}
func (d fuseDir) ReadDirAll(ctx context.Context) ([]fuse.Dirent, error) {
r, err := NewReader(d.blob.IO(ctx), d.align)
if err != nil {
return nil, err
}
var list []fuse.Dirent
it := r.Iter()
var de *wire.Dirent
for {
de, err = it.Next()
if err == io.EOF {
break
}
if err != nil {
return list, fmt.Errorf("snap readdir error: %v", err)
}
fde := fuse.Dirent{
Name: de.Name,
}
if de.File != nil {
fde.Type = fuse.DT_File
} else if de.Dir != nil {
fde.Type = fuse.DT_Dir
}
list = append(list, fde)
}
return list, nil
}
func (d fuseDir) Create(ctx context.Context, req *fuse.CreateRequest, resp *fuse.CreateResponse) (fusefs.Node, fusefs.Handle, error) {
return nil, nil, fuse.Errno(syscall.EROFS)
}