fuse: support readdirplus, combines readdir and lookup/getattr.

This adds ReadDirPlus to RawFileSystem. Node and path filesystems take
advantage of ReadDirPlus automatically.

fuse/api.go

@@ -61,7 +61,7 @@ type MountOptions struct {
 	// small.
 	Name string
 
-	// If set, wrap the file system in a single-threaded wrapper.
+	// If set, wrap the file system in a single-threaded locking wrapper.
 	SingleThreaded bool
 }
 
@@ -119,6 +119,7 @@ type RawFileSystem interface {
 	// Directory handling
 	OpenDir(out *raw.OpenOut, context *Context, input *raw.OpenIn) (status Status)
 	ReadDir(out *DirEntryList, context *Context, input *raw.ReadIn) Status
+	ReadDirPlus(out *DirEntryList, context *Context, input *raw.ReadIn) Status
 	ReleaseDir(context *Context, input *raw.ReleaseIn)
 	FsyncDir(context *Context, input *raw.FsyncIn) (code Status)
 

fuse/defaultraw.go

@@ -134,6 +134,10 @@ func (fs *defaultRawFileSystem) ReadDir(l *DirEntryList, context *Context, input
 	return ENOSYS
 }
 
+func (fs *defaultRawFileSystem) ReadDirPlus(l *DirEntryList, context *Context, input *raw.ReadIn) Status {
+	return ENOSYS
+}
+
 func (fs *defaultRawFileSystem) ReleaseDir(context *Context, input *raw.ReleaseIn) {
 }
 

fuse/direntry.go

@@ -3,13 +3,12 @@ package fuse
 // all of the code for DirEntryList.
 
 import (
-	"log"
+	"fmt"
 	"unsafe"
 
 	"github.com/hanwen/go-fuse/raw"
 )
 
-var _ = log.Print
 var eightPadding [8]byte
 
 const direntSize = int(unsafe.Sizeof(raw.Dirent{}))
@@ -21,6 +20,10 @@ type DirEntry struct {
 	Name string
 }
 
+func (d DirEntry) String() string {
+	return fmt.Sprintf("%o: %q", d.Mode, d.Name)
+}
+
 type DirEntryList struct {
 	buf  []byte
 	size int
@@ -39,12 +42,12 @@ func NewDirEntryList(data []byte, off uint64) *DirEntryList {
 
 // AddDirEntry tries to add an entry.
 func (l *DirEntryList) AddDirEntry(e DirEntry) bool {
-	return l.Add(e.Name, uint64(raw.FUSE_UNKNOWN_INO), e.Mode)
+	return l.Add(nil, e.Name, uint64(raw.FUSE_UNKNOWN_INO), e.Mode)
 }
 
-func (l *DirEntryList) Add(name string, inode uint64, mode uint32) bool {
+func (l *DirEntryList) Add(prefix []byte, name string, inode uint64, mode uint32) bool {
 	padding := (8 - len(name)&7) & 7
-	delta := padding + direntSize + len(name)
+	delta := padding + direntSize + len(name) + len(prefix)
 	oldLen := len(l.buf)
 	newLen := delta + oldLen
 
@@ -52,6 +55,8 @@ func (l *DirEntryList) Add(name string, inode uint64, mode uint32) bool {
 		return false
 	}
 	l.buf = l.buf[:newLen]
+	copy(l.buf[oldLen:], prefix)
+	oldLen += len(prefix)
 	dirent := (*raw.Dirent)(unsafe.Pointer(&l.buf[oldLen]))
 	dirent.Off = l.Offset + 1
 	dirent.Ino = inode
@@ -69,6 +74,12 @@ func (l *DirEntryList) Add(name string, inode uint64, mode uint32) bool {
 	return true
 }
 
+func (l *DirEntryList) AddDirLookupEntry(e DirEntry, entryOut *raw.EntryOut) bool {
+	var lookup []byte
+	toSlice(&lookup, unsafe.Pointer(entryOut), unsafe.Sizeof(raw.EntryOut{}))
+	return l.Add(lookup, e.Name, uint64(raw.FUSE_UNKNOWN_INO), e.Mode)
+}
+
 func (l *DirEntryList) Bytes() []byte {
 	return l.buf
 }

fuse/lockingfs.go

@@ -179,6 +179,11 @@ func (fs *lockingRawFileSystem) ReadDir(out *DirEntryList, header *Context, inpu
 	return fs.RawFS.ReadDir(out, header, input)
 }
 
+func (fs *lockingRawFileSystem) ReadDirPlus(out *DirEntryList, header *Context, input *raw.ReadIn) Status {
+	defer fs.locked()()
+	return fs.RawFS.ReadDirPlus(out, header, input)
+}
+
 func (fs *lockingRawFileSystem) FsyncDir(header *Context, input *raw.FsyncIn) (code Status) {
 	defer fs.locked()()
 	return fs.RawFS.FsyncDir(header, input)

fuse/nodefs/dir.go

@@ -11,16 +11,18 @@ type connectorDir struct {
 	node       Node
 	stream     []fuse.DirEntry
 	lastOffset uint64
+	rawFS      fuse.RawFileSystem
+	lookups    []raw.EntryOut
 }
 
-func (d *connectorDir) ReadDir(list *fuse.DirEntryList, input *raw.ReadIn) (code fuse.Status) {
+func (d *connectorDir) ReadDir(list *fuse.DirEntryList, input *raw.ReadIn, context *fuse.Context) (code fuse.Status) {
 	if d.stream == nil {
 		return fuse.OK
 	}
 	// rewinddir() should be as if reopening directory.
 	// TODO - test this.
 	if d.lastOffset > 0 && input.Offset == 0 {
-		d.stream, code = d.node.OpenDir(nil)
+		d.stream, code = d.node.OpenDir(context)
 		if !code.Ok() {
 			return code
 		}
@@ -40,11 +42,55 @@ func (d *connectorDir) ReadDir(list *fuse.DirEntryList, input *raw.ReadIn) (code
 	return fuse.OK
 }
 
+func (d *connectorDir) ReadDirPlus(list *fuse.DirEntryList, input *raw.ReadIn, context *fuse.Context) (code fuse.Status) {
+	if d.stream == nil {
+		return fuse.OK
+	}
+
+	// rewinddir() should be as if reopening directory.
+	if d.lastOffset > 0 && input.Offset == 0 {
+		d.stream, code = d.node.OpenDir(context)
+		if !code.Ok() {
+			return code
+		}
+		d.lookups = nil
+	}
+
+	if d.lookups == nil {
+		d.lookups = make([]raw.EntryOut, len(d.stream))
+		for i, n := range d.stream {
+			if n.Name == "." || n.Name == ".." {
+				continue
+			}
+			// We ignore the return value
+			code := d.rawFS.Lookup(&d.lookups[i], context, n.Name)
+			if !code.Ok() {
+				d.lookups[i] = raw.EntryOut{}
+			}
+		}
+	}
+
+	todo := d.stream[input.Offset:]
+	for i, e := range todo {
+		if e.Name == "" {
+			log.Printf("got empty directory entry, mode %o.", e.Mode)
+			continue
+		}
+		if !list.AddDirLookupEntry(e, &d.lookups[i]) {
+			break
+		}
+	}
+	d.lastOffset = list.Offset
+	return fuse.OK
+
+}
+
 // Read everything so we make goroutines exit.
 func (d *connectorDir) Release() {
 }
 
 type rawDir interface {
-	ReadDir(out *fuse.DirEntryList, input *raw.ReadIn) fuse.Status
+	ReadDir(out *fuse.DirEntryList, input *raw.ReadIn, c *fuse.Context) fuse.Status
+	ReadDirPlus(out *fuse.DirEntryList, input *raw.ReadIn, c *fuse.Context) fuse.Status
 	Release()
 }

fuse/nodefs/fsops.go

@@ -157,6 +157,7 @@ func (c *rawBridge) OpenDir(out *raw.OpenOut, context *fuse.Context, input *raw.
 		stream: append(stream,
 			fuse.DirEntry{fuse.S_IFDIR, "."},
 			fuse.DirEntry{fuse.S_IFDIR, ".."}),
+		rawFS: c,
 	}
 	h, opened := node.mount.registerFileHandle(node, de, nil, input.Flags)
 	out.OpenFlags = opened.FuseFlags
@@ -167,7 +168,13 @@ func (c *rawBridge) OpenDir(out *raw.OpenOut, context *fuse.Context, input *raw.
 func (c *rawBridge) ReadDir(l *fuse.DirEntryList, context *fuse.Context, input *raw.ReadIn) fuse.Status {
 	node := c.toInode(context.NodeId)
 	opened := node.mount.getOpenedFile(input.Fh)
-	return opened.dir.ReadDir(l, input)
+	return opened.dir.ReadDir(l, input, context)
+}
+
+func (c *rawBridge) ReadDirPlus(l *fuse.DirEntryList, context *fuse.Context, input *raw.ReadIn) fuse.Status {
+	node := c.toInode(context.NodeId)
+	opened := node.mount.getOpenedFile(input.Fh)
+	return opened.dir.ReadDirPlus(l, input, context)
 }
 
 func (c *rawBridge) Open(out *raw.OpenOut, context *fuse.Context, input *raw.OpenIn) (status fuse.Status) {

fuse/opcode.go

@@ -82,7 +82,9 @@ func doInit(state *Server, req *request) {
 
 	state.reqMu.Lock()
 	state.kernelSettings = *input
-	state.kernelSettings.Flags = input.Flags & (raw.CAP_ASYNC_READ | raw.CAP_BIG_WRITES | raw.CAP_FILE_OPS | raw.CAP_AUTO_INVAL_DATA)
+	state.kernelSettings.Flags = input.Flags & (raw.CAP_ASYNC_READ | raw.CAP_BIG_WRITES | raw.CAP_FILE_OPS |
+		raw.CAP_AUTO_INVAL_DATA | raw.CAP_READDIRPLUS)
+
 	if input.Minor >= 13 {
 		state.setSplice()
 	}
@@ -130,6 +132,16 @@ func doReadDir(state *Server, req *request) {
 	req.status = code
 }
 
+func doReadDirPlus(server *Server, req *request) {
+	in := (*raw.ReadIn)(req.inData)
+	buf := server.allocOut(req, in.Size)
+	entries := NewDirEntryList(buf, uint64(in.Offset))
+
+	code := server.fileSystem.ReadDirPlus(entries, &req.context, in)
+	req.flatData = entries.Bytes()
+	req.status = code
+}
+
 func doOpenDir(state *Server, req *request) {
 	out := (*raw.OpenOut)(req.outData)
 	status := state.fileSystem.OpenDir(out, &req.context, (*raw.OpenIn)(req.inData))
@@ -417,6 +429,7 @@ func init() {
 		_OP_IOCTL:        unsafe.Sizeof(raw.IoctlIn{}),
 		_OP_POLL:         unsafe.Sizeof(raw.PollIn{}),
 		_OP_FALLOCATE:    unsafe.Sizeof(raw.FallocateIn{}),
+		_OP_READDIRPLUS:  unsafe.Sizeof(raw.ReadIn{}),
 	} {
 		operationHandlers[op].InputSize = sz
 	}
@@ -531,6 +544,7 @@ func init() {
 		_OP_IOCTL:        doIoctl,
 		_OP_DESTROY:      doDestroy,
 		_OP_FALLOCATE:    doFallocate,
+		_OP_READDIRPLUS:  doReadDirPlus,
 	} {
 		operationHandlers[op].Func = v
 	}
@@ -576,6 +590,7 @@ func init() {
 		_OP_RELEASE:      func(ptr unsafe.Pointer) interface{} { return (*raw.ReleaseIn)(ptr) },
 		_OP_RELEASEDIR:   func(ptr unsafe.Pointer) interface{} { return (*raw.ReleaseIn)(ptr) },
 		_OP_FALLOCATE:    func(ptr unsafe.Pointer) interface{} { return (*raw.FallocateIn)(ptr) },
+		_OP_READDIRPLUS:  func(ptr unsafe.Pointer) interface{} { return (*raw.ReadIn)(ptr) },
 	} {
 		operationHandlers[op].DecodeIn = f
 	}

fuse/request_linux.go

@@ -5,5 +5,5 @@ const outputHeaderSize = 160
 const (
 	_FUSE_KERNEL_VERSION   = 7
 	_MINIMUM_MINOR_VERSION = 12
-	_OUR_MINOR_VERSION     = 20
+	_OUR_MINOR_VERSION     = 21
 )