support read

18 files changed, 1257 insertions, 24 deletions

diff --git a/weed/mount/dirty_pages_chunked.go b/weed/mount/dirty_pages_chunked.go
new file mode 100644
index 000000000..5ffcff83a
--- /dev/null
+++ b/weed/mount/dirty_pages_chunked.go
@@ -0,0 +1,99 @@
+package mount
+
+import (
+	"fmt"
+	"github.com/chrislusf/seaweedfs/weed/filesys/page_writer"
+	"github.com/chrislusf/seaweedfs/weed/glog"
+	"github.com/chrislusf/seaweedfs/weed/pb/filer_pb"
+	"io"
+	"sync"
+	"time"
+)
+
+type ChunkedDirtyPages struct {
+	fh             *FileHandle
+	writeWaitGroup sync.WaitGroup
+	lastErr        error
+	collection     string
+	replication    string
+	uploadPipeline *page_writer.UploadPipeline
+	hasWrites      bool
+}
+
+var (
+	_ = page_writer.DirtyPages(&ChunkedDirtyPages{})
+)
+
+func newMemoryChunkPages(fh *FileHandle, chunkSize int64) *ChunkedDirtyPages {
+
+	dirtyPages := &ChunkedDirtyPages{
+		fh: fh,
+	}
+
+	dirtyPages.uploadPipeline = page_writer.NewUploadPipeline(fh.wfs.concurrentWriters, chunkSize, dirtyPages.saveChunkedFileIntevalToStorage, fh.wfs.option.ConcurrentWriters)
+
+	return dirtyPages
+}
+
+func (pages *ChunkedDirtyPages) AddPage(offset int64, data []byte) {
+	pages.hasWrites = true
+
+	glog.V(4).Infof("%v memory AddPage [%d, %d)", pages.fh, offset, offset+int64(len(data)))
+	pages.uploadPipeline.SaveDataAt(data, offset)
+
+	return
+}
+
+func (pages *ChunkedDirtyPages) FlushData() error {
+	if !pages.hasWrites {
+		return nil
+	}
+	pages.uploadPipeline.FlushAll()
+	if pages.lastErr != nil {
+		return fmt.Errorf("flush data: %v", pages.lastErr)
+	}
+	return nil
+}
+
+func (pages *ChunkedDirtyPages) ReadDirtyDataAt(data []byte, startOffset int64) (maxStop int64) {
+	if !pages.hasWrites {
+		return
+	}
+	return pages.uploadPipeline.MaybeReadDataAt(data, startOffset)
+}
+
+func (pages *ChunkedDirtyPages) GetStorageOptions() (collection, replication string) {
+	return pages.collection, pages.replication
+}
+
+func (pages *ChunkedDirtyPages) saveChunkedFileIntevalToStorage(reader io.Reader, offset int64, size int64, cleanupFn func()) {
+
+	mtime := time.Now().UnixNano()
+	defer cleanupFn()
+
+	fileFullPath := pages.fh.FullPath()
+	fileName := fileFullPath.Name()
+	chunk, collection, replication, err := pages.fh.wfs.saveDataAsChunk(fileFullPath)(reader, fileName, offset)
+	if err != nil {
+		glog.V(0).Infof("%v saveToStorage [%d,%d): %v", fileFullPath, offset, offset+size, err)
+		pages.lastErr = err
+		return
+	}
+	chunk.Mtime = mtime
+	pages.collection, pages.replication = collection, replication
+	pages.fh.addChunks([]*filer_pb.FileChunk{chunk})
+	pages.fh.entryViewCache = nil
+	glog.V(3).Infof("%v saveToStorage %s [%d,%d)", fileFullPath, chunk.FileId, offset, offset+size)
+
+}
+
+func (pages ChunkedDirtyPages) Destroy() {
+	pages.uploadPipeline.Shutdown()
+}
+
+func (pages *ChunkedDirtyPages) LockForRead(startOffset, stopOffset int64) {
+	pages.uploadPipeline.LockForRead(startOffset, stopOffset)
+}
+func (pages *ChunkedDirtyPages) UnlockForRead(startOffset, stopOffset int64) {
+	pages.uploadPipeline.UnlockForRead(startOffset, stopOffset)
+}
diff --git a/weed/mount/filehandle.go b/weed/mount/filehandle.go
new file mode 100644
index 000000000..0d5481b30
--- /dev/null
+++ b/weed/mount/filehandle.go
@@ -0,0 +1,94 @@
+package mount
+
+import (
+	"github.com/chrislusf/seaweedfs/weed/filer"
+	"github.com/chrislusf/seaweedfs/weed/glog"
+	"github.com/chrislusf/seaweedfs/weed/pb/filer_pb"
+	"github.com/chrislusf/seaweedfs/weed/util"
+	"io"
+	"sort"
+	"sync"
+)
+
+type FileHandleId uint64
+
+type FileHandle struct {
+	fh           FileHandleId
+	counter      int64
+	entry        *filer_pb.Entry
+	chunkAddLock sync.Mutex
+	inode        uint64
+	wfs          *WFS
+
+	// cache file has been written to
+	dirtyPages     *PageWriter
+	entryViewCache []filer.VisibleInterval
+	reader         io.ReaderAt
+	contentType    string
+	handle         uint64
+	sync.Mutex
+
+	isDeleted bool
+}
+
+func newFileHandle(wfs *WFS, handleId FileHandleId, inode uint64, entry *filer_pb.Entry) *FileHandle {
+	fh := &FileHandle{
+		fh:      handleId,
+		counter: 1,
+		inode:   inode,
+		wfs:     wfs,
+	}
+	// dirtyPages: newContinuousDirtyPages(file, writeOnly),
+	fh.dirtyPages = newPageWriter(fh, wfs.option.ChunkSizeLimit)
+	if entry != nil {
+		entry.Attributes.FileSize = filer.FileSize(entry)
+	}
+
+	return fh
+}
+
+func (fh *FileHandle) FullPath() util.FullPath {
+	return fh.wfs.inodeToPath.GetPath(fh.inode)
+}
+
+func (fh *FileHandle) addChunks(chunks []*filer_pb.FileChunk) {
+
+	// find the earliest incoming chunk
+	newChunks := chunks
+	earliestChunk := newChunks[0]
+	for i := 1; i < len(newChunks); i++ {
+		if lessThan(earliestChunk, newChunks[i]) {
+			earliestChunk = newChunks[i]
+		}
+	}
+
+	if fh.entry == nil {
+		return
+	}
+
+	// pick out-of-order chunks from existing chunks
+	for _, chunk := range fh.entry.Chunks {
+		if lessThan(earliestChunk, chunk) {
+			chunks = append(chunks, chunk)
+		}
+	}
+
+	// sort incoming chunks
+	sort.Slice(chunks, func(i, j int) bool {
+		return lessThan(chunks[i], chunks[j])
+	})
+
+	glog.V(4).Infof("%s existing %d chunks adds %d more", fh.FullPath(), len(fh.entry.Chunks), len(chunks))
+
+	fh.chunkAddLock.Lock()
+	fh.entry.Chunks = append(fh.entry.Chunks, newChunks...)
+	fh.entryViewCache = nil
+	fh.chunkAddLock.Unlock()
+}
+
+func lessThan(a, b *filer_pb.FileChunk) bool {
+	if a.Mtime == b.Mtime {
+		return a.Fid.FileKey < b.Fid.FileKey
+	}
+	return a.Mtime < b.Mtime
+}
diff --git a/weed/mount/filehandle_map.go b/weed/mount/filehandle_map.go
index ca010dabb..50ca6bcea 100644
--- a/weed/mount/filehandle_map.go
+++ b/weed/mount/filehandle_map.go
@@ -5,20 +5,12 @@ import (
 	"sync"
 )
 
-type FileHandleId uint64
-
 type FileHandleToInode struct {
 	sync.RWMutex
 	nextFh   FileHandleId
 	inode2fh map[uint64]*FileHandle
 	fh2inode map[FileHandleId]uint64
 }
-type FileHandle struct {
-	fh      FileHandleId
-	counter int64
-	entry   *filer_pb.Entry
-	inode   uint64
-}
 
 func NewFileHandleToInode() *FileHandleToInode {
 	return &FileHandleToInode{
@@ -28,16 +20,22 @@ func NewFileHandleToInode() *FileHandleToInode {
 	}
 }
 
-func (i *FileHandleToInode) GetFileHandle(inode uint64) *FileHandle {
+func (i *FileHandleToInode) GetFileHandle(fh FileHandleId) *FileHandle {
+	i.RLock()
+	defer i.RUnlock()
+	inode, found := i.fh2inode[fh]
+	if found {
+		return i.inode2fh[inode]
+	}
+	return nil
+}
+
+func (i *FileHandleToInode) AcquireFileHandle(wfs *WFS, inode uint64, entry *filer_pb.Entry) *FileHandle {
 	i.Lock()
 	defer i.Unlock()
 	fh, found := i.inode2fh[inode]
 	if !found {
-		fh = &FileHandle{
-			fh:      i.nextFh,
-			counter: 1,
-			inode:   inode,
-		}
+		fh = newFileHandle(wfs, i.nextFh, inode, entry)
 		i.nextFh++
 		i.inode2fh[inode] = fh
 		i.fh2inode[fh.fh] = inode
diff --git a/weed/mount/filehandle_read.go b/weed/mount/filehandle_read.go
new file mode 100644
index 000000000..71166169e
--- /dev/null
+++ b/weed/mount/filehandle_read.go
@@ -0,0 +1,114 @@
+package mount
+
+import (
+	"context"
+	"fmt"
+	"github.com/chrislusf/seaweedfs/weed/filer"
+	"github.com/chrislusf/seaweedfs/weed/glog"
+	"github.com/chrislusf/seaweedfs/weed/pb/filer_pb"
+	"io"
+	"math"
+)
+
+func (fh *FileHandle) lockForRead(startOffset int64, size int) {
+	fh.dirtyPages.LockForRead(startOffset, startOffset+int64(size))
+}
+func (fh *FileHandle) unlockForRead(startOffset int64, size int) {
+	fh.dirtyPages.UnlockForRead(startOffset, startOffset+int64(size))
+}
+
+func (fh *FileHandle) readFromDirtyPages(buff []byte, startOffset int64) (maxStop int64) {
+	maxStop = fh.dirtyPages.ReadDirtyDataAt(buff, startOffset)
+	return
+}
+
+func (fh *FileHandle) readFromChunks(buff []byte, offset int64) (int64, error) {
+
+	fileFullPath := fh.FullPath()
+
+	entry := fh.entry
+	if entry == nil {
+		return 0, io.EOF
+	}
+
+	if entry.IsInRemoteOnly() {
+		glog.V(4).Infof("download remote entry %s", fileFullPath)
+		newEntry, err := fh.downloadRemoteEntry(entry)
+		if err != nil {
+			glog.V(1).Infof("download remote entry %s: %v", fileFullPath, err)
+			return 0, err
+		}
+		entry = newEntry
+	}
+
+	fileSize := int64(filer.FileSize(entry))
+
+	if fileSize == 0 {
+		glog.V(1).Infof("empty fh %v", fileFullPath)
+		return 0, io.EOF
+	}
+
+	if offset+int64(len(buff)) <= int64(len(entry.Content)) {
+		totalRead := copy(buff, entry.Content[offset:])
+		glog.V(4).Infof("file handle read cached %s [%d,%d] %d", fileFullPath, offset, offset+int64(totalRead), totalRead)
+		return int64(totalRead), nil
+	}
+
+	var chunkResolveErr error
+	if fh.entryViewCache == nil {
+		fh.entryViewCache, chunkResolveErr = filer.NonOverlappingVisibleIntervals(fh.wfs.LookupFn(), entry.Chunks, 0, math.MaxInt64)
+		if chunkResolveErr != nil {
+			return 0, fmt.Errorf("fail to resolve chunk manifest: %v", chunkResolveErr)
+		}
+		fh.reader = nil
+	}
+
+	reader := fh.reader
+	if reader == nil {
+		chunkViews := filer.ViewFromVisibleIntervals(fh.entryViewCache, 0, math.MaxInt64)
+		glog.V(4).Infof("file handle read %s [%d,%d) from %d views", fileFullPath, offset, offset+int64(len(buff)), len(chunkViews))
+		for _, chunkView := range chunkViews {
+			glog.V(4).Infof("  read %s [%d,%d) from chunk %+v", fileFullPath, chunkView.LogicOffset, chunkView.LogicOffset+int64(chunkView.Size), chunkView.FileId)
+		}
+		reader = filer.NewChunkReaderAtFromClient(fh.wfs.LookupFn(), chunkViews, fh.wfs.chunkCache, fileSize)
+	}
+	fh.reader = reader
+
+	totalRead, err := reader.ReadAt(buff, offset)
+
+	if err != nil && err != io.EOF {
+		glog.Errorf("file handle read %s: %v", fileFullPath, err)
+	}
+
+	glog.V(4).Infof("file handle read %s [%d,%d] %d : %v", fileFullPath, offset, offset+int64(totalRead), totalRead, err)
+
+	return int64(totalRead), err
+}
+
+func (fh *FileHandle) downloadRemoteEntry(entry *filer_pb.Entry) (*filer_pb.Entry, error) {
+
+	fileFullPath := fh.FullPath()
+	dir, _ := fileFullPath.DirAndName()
+
+	err := fh.wfs.WithFilerClient(false, func(client filer_pb.SeaweedFilerClient) error {
+
+		request := &filer_pb.CacheRemoteObjectToLocalClusterRequest{
+			Directory: string(dir),
+			Name:      entry.Name,
+		}
+
+		glog.V(4).Infof("download entry: %v", request)
+		resp, err := client.CacheRemoteObjectToLocalCluster(context.Background(), request)
+		if err != nil {
+			return fmt.Errorf("CacheRemoteObjectToLocalCluster file %s: %v", fileFullPath, err)
+		}
+
+		entry = resp.Entry
+
+		fh.wfs.metaCache.InsertEntry(context.Background(), filer.FromPbEntry(request.Directory, resp.Entry))
+
+		return nil
+	})
+
+	return entry, err
+}
diff --git a/weed/mount/page_writer.go b/weed/mount/page_writer.go
new file mode 100644
index 000000000..eaf1fc176
--- /dev/null
+++ b/weed/mount/page_writer.go
@@ -0,0 +1,95 @@
+package mount
+
+import (
+	"github.com/chrislusf/seaweedfs/weed/filesys/page_writer"
+	"github.com/chrislusf/seaweedfs/weed/glog"
+)
+
+type PageWriter struct {
+	fh          *FileHandle
+	collection  string
+	replication string
+	chunkSize   int64
+
+	randomWriter page_writer.DirtyPages
+}
+
+var (
+	_ = page_writer.DirtyPages(&PageWriter{})
+)
+
+func newPageWriter(fh *FileHandle, chunkSize int64) *PageWriter {
+	pw := &PageWriter{
+		fh:           fh,
+		chunkSize:    chunkSize,
+		randomWriter: newMemoryChunkPages(fh, chunkSize),
+		// randomWriter: newTempFileDirtyPages(fh.f, chunkSize),
+	}
+	return pw
+}
+
+func (pw *PageWriter) AddPage(offset int64, data []byte) {
+
+	glog.V(4).Infof("%v AddPage [%d, %d)", pw.fh, offset, offset+int64(len(data)))
+
+	chunkIndex := offset / pw.chunkSize
+	for i := chunkIndex; len(data) > 0; i++ {
+		writeSize := min(int64(len(data)), (i+1)*pw.chunkSize-offset)
+		pw.addToOneChunk(i, offset, data[:writeSize])
+		offset += writeSize
+		data = data[writeSize:]
+	}
+}
+
+func (pw *PageWriter) addToOneChunk(chunkIndex, offset int64, data []byte) {
+	pw.randomWriter.AddPage(offset, data)
+}
+
+func (pw *PageWriter) FlushData() error {
+	return pw.randomWriter.FlushData()
+}
+
+func (pw *PageWriter) ReadDirtyDataAt(data []byte, offset int64) (maxStop int64) {
+	glog.V(4).Infof("ReadDirtyDataAt %v [%d, %d)", pw.fh, offset, offset+int64(len(data)))
+
+	chunkIndex := offset / pw.chunkSize
+	for i := chunkIndex; len(data) > 0; i++ {
+		readSize := min(int64(len(data)), (i+1)*pw.chunkSize-offset)
+
+		maxStop = pw.randomWriter.ReadDirtyDataAt(data[:readSize], offset)
+
+		offset += readSize
+		data = data[readSize:]
+	}
+
+	return
+}
+
+func (pw *PageWriter) GetStorageOptions() (collection, replication string) {
+	return pw.randomWriter.GetStorageOptions()
+}
+
+func (pw *PageWriter) LockForRead(startOffset, stopOffset int64) {
+	pw.randomWriter.LockForRead(startOffset, stopOffset)
+}
+
+func (pw *PageWriter) UnlockForRead(startOffset, stopOffset int64) {
+	pw.randomWriter.UnlockForRead(startOffset, stopOffset)
+}
+
+func (pw *PageWriter) Destroy() {
+	pw.randomWriter.Destroy()
+}
+
+func max(x, y int64) int64 {
+	if x > y {
+		return x
+	}
+	return y
+}
+func min(x, y int64) int64 {
+	if x < y {
+		return x
+	}
+	return y
+}
diff --git a/weed/mount/page_writer/chunk_interval_list.go b/weed/mount/page_writer/chunk_interval_list.go
new file mode 100644
index 000000000..e6dc5d1f5
--- /dev/null
+++ b/weed/mount/page_writer/chunk_interval_list.go
@@ -0,0 +1,115 @@
+package page_writer
+
+import "math"
+
+// ChunkWrittenInterval mark one written interval within one page chunk
+type ChunkWrittenInterval struct {
+	StartOffset int64
+	stopOffset  int64
+	prev        *ChunkWrittenInterval
+	next        *ChunkWrittenInterval
+}
+
+func (interval *ChunkWrittenInterval) Size() int64 {
+	return interval.stopOffset - interval.StartOffset
+}
+
+func (interval *ChunkWrittenInterval) isComplete(chunkSize int64) bool {
+	return interval.stopOffset-interval.StartOffset == chunkSize
+}
+
+// ChunkWrittenIntervalList mark written intervals within one page chunk
+type ChunkWrittenIntervalList struct {
+	head *ChunkWrittenInterval
+	tail *ChunkWrittenInterval
+}
+
+func newChunkWrittenIntervalList() *ChunkWrittenIntervalList {
+	list := &ChunkWrittenIntervalList{
+		head: &ChunkWrittenInterval{
+			StartOffset: -1,
+			stopOffset:  -1,
+		},
+		tail: &ChunkWrittenInterval{
+			StartOffset: math.MaxInt64,
+			stopOffset:  math.MaxInt64,
+		},
+	}
+	list.head.next = list.tail
+	list.tail.prev = list.head
+	return list
+}
+
+func (list *ChunkWrittenIntervalList) MarkWritten(startOffset, stopOffset int64) {
+	interval := &ChunkWrittenInterval{
+		StartOffset: startOffset,
+		stopOffset:  stopOffset,
+	}
+	list.addInterval(interval)
+}
+
+func (list *ChunkWrittenIntervalList) IsComplete(chunkSize int64) bool {
+	return list.size() == 1 && list.head.next.isComplete(chunkSize)
+}
+func (list *ChunkWrittenIntervalList) WrittenSize() (writtenByteCount int64) {
+	for t := list.head; t != nil; t = t.next {
+		writtenByteCount += t.Size()
+	}
+	return
+}
+
+func (list *ChunkWrittenIntervalList) addInterval(interval *ChunkWrittenInterval) {
+
+	p := list.head
+	for ; p.next != nil && p.next.StartOffset <= interval.StartOffset; p = p.next {
+	}
+	q := list.tail
+	for ; q.prev != nil && q.prev.stopOffset >= interval.stopOffset; q = q.prev {
+	}
+
+	if interval.StartOffset <= p.stopOffset && q.StartOffset <= interval.stopOffset {
+		// merge p and q together
+		p.stopOffset = q.stopOffset
+		unlinkNodesBetween(p, q.next)
+		return
+	}
+	if interval.StartOffset <= p.stopOffset {
+		// merge new interval into p
+		p.stopOffset = interval.stopOffset
+		unlinkNodesBetween(p, q)
+		return
+	}
+	if q.StartOffset <= interval.stopOffset {
+		// merge new interval into q
+		q.StartOffset = interval.StartOffset
+		unlinkNodesBetween(p, q)
+		return
+	}
+
+	// add the new interval between p and q
+	unlinkNodesBetween(p, q)
+	p.next = interval
+	interval.prev = p
+	q.prev = interval
+	interval.next = q
+
+}
+
+// unlinkNodesBetween remove all nodes after start and before stop, exclusive
+func unlinkNodesBetween(start *ChunkWrittenInterval, stop *ChunkWrittenInterval) {
+	if start.next == stop {
+		return
+	}
+	start.next.prev = nil
+	start.next = stop
+	stop.prev.next = nil
+	stop.prev = start
+}
+
+func (list *ChunkWrittenIntervalList) size() int {
+	var count int
+	for t := list.head; t != nil; t = t.next {
+		count++
+	}
+	return count - 2
+}
diff --git a/weed/mount/page_writer/chunk_interval_list_test.go b/weed/mount/page_writer/chunk_interval_list_test.go
new file mode 100644
index 000000000..b22f5eb5d
--- /dev/null
+++ b/weed/mount/page_writer/chunk_interval_list_test.go
@@ -0,0 +1,49 @@
+package page_writer
+
+import (
+	"github.com/stretchr/testify/assert"
+	"testing"
+)
+
+func Test_PageChunkWrittenIntervalList(t *testing.T) {
+	list := newChunkWrittenIntervalList()
+
+	assert.Equal(t, 0, list.size(), "empty list")
+
+	list.MarkWritten(0, 5)
+	assert.Equal(t, 1, list.size(), "one interval")
+
+	list.MarkWritten(0, 5)
+	assert.Equal(t, 1, list.size(), "duplicated interval2")
+
+	list.MarkWritten(95, 100)
+	assert.Equal(t, 2, list.size(), "two intervals")
+
+	list.MarkWritten(50, 60)
+	assert.Equal(t, 3, list.size(), "three intervals")
+
+	list.MarkWritten(50, 55)
+	assert.Equal(t, 3, list.size(), "three intervals merge")
+
+	list.MarkWritten(40, 50)
+	assert.Equal(t, 3, list.size(), "three intervals grow forward")
+
+	list.MarkWritten(50, 65)
+	assert.Equal(t, 3, list.size(), "three intervals grow backward")
+
+	list.MarkWritten(70, 80)
+	assert.Equal(t, 4, list.size(), "four intervals")
+
+	list.MarkWritten(60, 70)
+	assert.Equal(t, 3, list.size(), "three intervals merged")
+
+	list.MarkWritten(59, 71)
+	assert.Equal(t, 3, list.size(), "covered three intervals")
+
+	list.MarkWritten(5, 59)
+	assert.Equal(t, 2, list.size(), "covered two intervals")
+
+	list.MarkWritten(70, 99)
+	assert.Equal(t, 1, list.size(), "covered one intervals")
+
+}
diff --git a/weed/mount/page_writer/dirty_pages.go b/weed/mount/page_writer/dirty_pages.go
new file mode 100644
index 000000000..25b747fad
--- /dev/null
+++ b/weed/mount/page_writer/dirty_pages.go
@@ -0,0 +1,30 @@
+package page_writer
+
+type DirtyPages interface {
+	AddPage(offset int64, data []byte)
+	FlushData() error
+	ReadDirtyDataAt(data []byte, startOffset int64) (maxStop int64)
+	GetStorageOptions() (collection, replication string)
+	Destroy()
+	LockForRead(startOffset, stopOffset int64)
+	UnlockForRead(startOffset, stopOffset int64)
+}
+
+func max(x, y int64) int64 {
+	if x > y {
+		return x
+	}
+	return y
+}
+func min(x, y int64) int64 {
+	if x < y {
+		return x
+	}
+	return y
+}
+func minInt(x, y int) int {
+	if x < y {
+		return x
+	}
+	return y
+}
diff --git a/weed/mount/page_writer/page_chunk.go b/weed/mount/page_writer/page_chunk.go
new file mode 100644
index 000000000..4e8f31425
--- /dev/null
+++ b/weed/mount/page_writer/page_chunk.go
@@ -0,0 +1,16 @@
+package page_writer
+
+import (
+	"io"
+)
+
+type SaveToStorageFunc func(reader io.Reader, offset int64, size int64, cleanupFn func())
+
+type PageChunk interface {
+	FreeResource()
+	WriteDataAt(src []byte, offset int64) (n int)
+	ReadDataAt(p []byte, off int64) (maxStop int64)
+	IsComplete() bool
+	WrittenSize() int64
+	SaveContent(saveFn SaveToStorageFunc)
+}
diff --git a/weed/mount/page_writer/page_chunk_mem.go b/weed/mount/page_writer/page_chunk_mem.go
new file mode 100644
index 000000000..dfd54c19e
--- /dev/null
+++ b/weed/mount/page_writer/page_chunk_mem.go
@@ -0,0 +1,69 @@
+package page_writer
+
+import (
+	"github.com/chrislusf/seaweedfs/weed/util"
+	"github.com/chrislusf/seaweedfs/weed/util/mem"
+)
+
+var (
+	_ = PageChunk(&MemChunk{})
+)
+
+type MemChunk struct {
+	buf             []byte
+	usage           *ChunkWrittenIntervalList
+	chunkSize       int64
+	logicChunkIndex LogicChunkIndex
+}
+
+func NewMemChunk(logicChunkIndex LogicChunkIndex, chunkSize int64) *MemChunk {
+	return &MemChunk{
+		logicChunkIndex: logicChunkIndex,
+		chunkSize:       chunkSize,
+		buf:             mem.Allocate(int(chunkSize)),
+		usage:           newChunkWrittenIntervalList(),
+	}
+}
+
+func (mc *MemChunk) FreeResource() {
+	mem.Free(mc.buf)
+}
+
+func (mc *MemChunk) WriteDataAt(src []byte, offset int64) (n int) {
+	innerOffset := offset % mc.chunkSize
+	n = copy(mc.buf[innerOffset:], src)
+	mc.usage.MarkWritten(innerOffset, innerOffset+int64(n))
+	return
+}
+
+func (mc *MemChunk) ReadDataAt(p []byte, off int64) (maxStop int64) {
+	memChunkBaseOffset := int64(mc.logicChunkIndex) * mc.chunkSize
+	for t := mc.usage.head.next; t != mc.usage.tail; t = t.next {
+		logicStart := max(off, int64(mc.logicChunkIndex)*mc.chunkSize+t.StartOffset)
+		logicStop := min(off+int64(len(p)), memChunkBaseOffset+t.stopOffset)
+		if logicStart < logicStop {
+			copy(p[logicStart-off:logicStop-off], mc.buf[logicStart-memChunkBaseOffset:logicStop-memChunkBaseOffset])
+			maxStop = max(maxStop, logicStop)
+		}
+	}
+	return
+}
+
+func (mc *MemChunk) IsComplete() bool {
+	return mc.usage.IsComplete(mc.chunkSize)
+}
+
+func (mc *MemChunk) WrittenSize() int64 {
+	return mc.usage.WrittenSize()
+}
+
+func (mc *MemChunk) SaveContent(saveFn SaveToStorageFunc) {
+	if saveFn == nil {
+		return
+	}
+	for t := mc.usage.head.next; t != mc.usage.tail; t = t.next {
+		reader := util.NewBytesReader(mc.buf[t.StartOffset:t.stopOffset])
+		saveFn(reader, int64(mc.logicChunkIndex)*mc.chunkSize+t.StartOffset, t.Size(), func() {
+		})
+	}
+}
diff --git a/weed/mount/page_writer/page_chunk_swapfile.go b/weed/mount/page_writer/page_chunk_swapfile.go
new file mode 100644
index 000000000..486557629
--- /dev/null
+++ b/weed/mount/page_writer/page_chunk_swapfile.go
@@ -0,0 +1,121 @@
+package page_writer
+
+import (
+	"github.com/chrislusf/seaweedfs/weed/glog"
+	"github.com/chrislusf/seaweedfs/weed/util"
+	"github.com/chrislusf/seaweedfs/weed/util/mem"
+	"os"
+)
+
+var (
+	_ = PageChunk(&SwapFileChunk{})
+)
+
+type ActualChunkIndex int
+
+type SwapFile struct {
+	dir                     string
+	file                    *os.File
+	logicToActualChunkIndex map[LogicChunkIndex]ActualChunkIndex
+	chunkSize               int64
+}
+
+type SwapFileChunk struct {
+	swapfile         *SwapFile
+	usage            *ChunkWrittenIntervalList
+	logicChunkIndex  LogicChunkIndex
+	actualChunkIndex ActualChunkIndex
+}
+
+func NewSwapFile(dir string, chunkSize int64) *SwapFile {
+	return &SwapFile{
+		dir:                     dir,
+		file:                    nil,
+		logicToActualChunkIndex: make(map[LogicChunkIndex]ActualChunkIndex),
+		chunkSize:               chunkSize,
+	}
+}
+func (sf *SwapFile) FreeResource() {
+	if sf.file != nil {
+		sf.file.Close()
+		os.Remove(sf.file.Name())
+	}
+}
+
+func (sf *SwapFile) NewTempFileChunk(logicChunkIndex LogicChunkIndex) (tc *SwapFileChunk) {
+	if sf.file == nil {
+		var err error
+		sf.file, err = os.CreateTemp(sf.dir, "")
+		if err != nil {
+			glog.Errorf("create swap file: %v", err)
+			return nil
+		}
+	}
+	actualChunkIndex, found := sf.logicToActualChunkIndex[logicChunkIndex]
+	if !found {
+		actualChunkIndex = ActualChunkIndex(len(sf.logicToActualChunkIndex))
+		sf.logicToActualChunkIndex[logicChunkIndex] = actualChunkIndex
+	}
+
+	return &SwapFileChunk{
+		swapfile:         sf,
+		usage:            newChunkWrittenIntervalList(),
+		logicChunkIndex:  logicChunkIndex,
+		actualChunkIndex: actualChunkIndex,
+	}
+}
+
+func (sc *SwapFileChunk) FreeResource() {
+}
+
+func (sc *SwapFileChunk) WriteDataAt(src []byte, offset int64) (n int) {
+	innerOffset := offset % sc.swapfile.chunkSize
+	var err error
+	n, err = sc.swapfile.file.WriteAt(src, int64(sc.actualChunkIndex)*sc.swapfile.chunkSize+innerOffset)
+	if err == nil {
+		sc.usage.MarkWritten(innerOffset, innerOffset+int64(n))
+	} else {
+		glog.Errorf("failed to write swap file %s: %v", sc.swapfile.file.Name(), err)
+	}
+	return
+}
+
+func (sc *SwapFileChunk) ReadDataAt(p []byte, off int64) (maxStop int64) {
+	chunkStartOffset := int64(sc.logicChunkIndex) * sc.swapfile.chunkSize
+	for t := sc.usage.head.next; t != sc.usage.tail; t = t.next {
+		logicStart := max(off, chunkStartOffset+t.StartOffset)
+		logicStop := min(off+int64(len(p)), chunkStartOffset+t.stopOffset)
+		if logicStart < logicStop {
+			actualStart := logicStart - chunkStartOffset + int64(sc.actualChunkIndex)*sc.swapfile.chunkSize
+			if _, err := sc.swapfile.file.ReadAt(p[logicStart-off:logicStop-off], actualStart); err != nil {
+				glog.Errorf("failed to reading swap file %s: %v", sc.swapfile.file.Name(), err)
+				break
+			}
+			maxStop = max(maxStop, logicStop)
+		}
+	}
+	return
+}
+
+func (sc *SwapFileChunk) IsComplete() bool {
+	return sc.usage.IsComplete(sc.swapfile.chunkSize)
+}
+
+func (sc *SwapFileChunk) WrittenSize() int64 {
+	return sc.usage.WrittenSize()
+}
+
+func (sc *SwapFileChunk) SaveContent(saveFn SaveToStorageFunc) {
+	if saveFn == nil {
+		return
+	}
+	for t := sc.usage.head.next; t != sc.usage.tail; t = t.next {
+		data := mem.Allocate(int(t.Size()))
+		sc.swapfile.file.ReadAt(data, t.StartOffset+int64(sc.actualChunkIndex)*sc.swapfile.chunkSize)
+		reader := util.NewBytesReader(data)
+		saveFn(reader, int64(sc.logicChunkIndex)*sc.swapfile.chunkSize+t.StartOffset, t.Size(), func() {
+		})
+		mem.Free(data)
+	}
+	sc.usage = newChunkWrittenIntervalList()
+}
diff --git a/weed/mount/page_writer/upload_pipeline.go b/weed/mount/page_writer/upload_pipeline.go
new file mode 100644
index 000000000..53641e66d
--- /dev/null
+++ b/weed/mount/page_writer/upload_pipeline.go
@@ -0,0 +1,182 @@
+package page_writer
+
+import (
+	"fmt"
+	"github.com/chrislusf/seaweedfs/weed/glog"
+	"github.com/chrislusf/seaweedfs/weed/util"
+	"sync"
+	"sync/atomic"
+	"time"
+)
+
+type LogicChunkIndex int
+
+type UploadPipeline struct {
+	filepath             util.FullPath
+	ChunkSize            int64
+	writableChunks       map[LogicChunkIndex]PageChunk
+	writableChunksLock   sync.Mutex
+	sealedChunks         map[LogicChunkIndex]*SealedChunk
+	sealedChunksLock     sync.Mutex
+	uploaders            *util.LimitedConcurrentExecutor
+	uploaderCount        int32
+	uploaderCountCond    *sync.Cond
+	saveToStorageFn      SaveToStorageFunc
+	activeReadChunks     map[LogicChunkIndex]int
+	activeReadChunksLock sync.Mutex
+	bufferChunkLimit     int
+}
+
+type SealedChunk struct {
+	chunk            PageChunk
+	referenceCounter int // track uploading or reading processes
+}
+
+func (sc *SealedChunk) FreeReference(messageOnFree string) {
+	sc.referenceCounter--
+	if sc.referenceCounter == 0 {
+		glog.V(4).Infof("Free sealed chunk: %s", messageOnFree)
+		sc.chunk.FreeResource()
+	}
+}
+
+func NewUploadPipeline(writers *util.LimitedConcurrentExecutor, chunkSize int64, saveToStorageFn SaveToStorageFunc, bufferChunkLimit int) *UploadPipeline {
+	return &UploadPipeline{
+		ChunkSize:         chunkSize,
+		writableChunks:    make(map[LogicChunkIndex]PageChunk),
+		sealedChunks:      make(map[LogicChunkIndex]*SealedChunk),
+		uploaders:         writers,
+		uploaderCountCond: sync.NewCond(&sync.Mutex{}),
+		saveToStorageFn:   saveToStorageFn,
+		activeReadChunks:  make(map[LogicChunkIndex]int),
+		bufferChunkLimit:  bufferChunkLimit,
+	}
+}
+
+func (up *UploadPipeline) SaveDataAt(p []byte, off int64) (n int) {
+	up.writableChunksLock.Lock()
+	defer up.writableChunksLock.Unlock()
+
+	logicChunkIndex := LogicChunkIndex(off / up.ChunkSize)
+
+	memChunk, found := up.writableChunks[logicChunkIndex]
+	if !found {
+		if len(up.writableChunks) < up.bufferChunkLimit {
+			memChunk = NewMemChunk(logicChunkIndex, up.ChunkSize)
+		} else {
+			fullestChunkIndex, fullness := LogicChunkIndex(-1), int64(0)
+			for lci, mc := range up.writableChunks {
+				chunkFullness := mc.WrittenSize()
+				if fullness < chunkFullness {
+					fullestChunkIndex = lci
+					fullness = chunkFullness
+				}
+			}
+			up.moveToSealed(up.writableChunks[fullestChunkIndex], fullestChunkIndex)
+			delete(up.writableChunks, fullestChunkIndex)
+			fmt.Printf("flush chunk %d with %d bytes written", logicChunkIndex, fullness)
+			memChunk = NewMemChunk(logicChunkIndex, up.ChunkSize)
+		}
+		up.writableChunks[logicChunkIndex] = memChunk
+	}
+	n = memChunk.WriteDataAt(p, off)
+	up.maybeMoveToSealed(memChunk, logicChunkIndex)
+
+	return
+}
+
+func (up *UploadPipeline) MaybeReadDataAt(p []byte, off int64) (maxStop int64) {
+	logicChunkIndex := LogicChunkIndex(off / up.ChunkSize)
+
+	// read from sealed chunks first
+	up.sealedChunksLock.Lock()
+	sealedChunk, found := up.sealedChunks[logicChunkIndex]
+	if found {
+		sealedChunk.referenceCounter++
+	}
+	up.sealedChunksLock.Unlock()
+	if found {
+		maxStop = sealedChunk.chunk.ReadDataAt(p, off)
+		glog.V(4).Infof("%s read sealed memchunk [%d,%d)", up.filepath, off, maxStop)
+		sealedChunk.FreeReference(fmt.Sprintf("%s finish reading chunk %d", up.filepath, logicChunkIndex))
+	}
+
+	// read from writable chunks last
+	up.writableChunksLock.Lock()
+	defer up.writableChunksLock.Unlock()
+	writableChunk, found := up.writableChunks[logicChunkIndex]
+	if !found {
+		return
+	}
+	writableMaxStop := writableChunk.ReadDataAt(p, off)
+	glog.V(4).Infof("%s read writable memchunk [%d,%d)", up.filepath, off, writableMaxStop)
+	maxStop = max(maxStop, writableMaxStop)
+
+	return
+}
+
+func (up *UploadPipeline) FlushAll() {
+	up.writableChunksLock.Lock()
+	defer up.writableChunksLock.Unlock()
+
+	for logicChunkIndex, memChunk := range up.writableChunks {
+		up.moveToSealed(memChunk, logicChunkIndex)
+	}
+
+	up.waitForCurrentWritersToComplete()
+}
+
+func (up *UploadPipeline) maybeMoveToSealed(memChunk PageChunk, logicChunkIndex LogicChunkIndex) {
+	if memChunk.IsComplete() {
+		up.moveToSealed(memChunk, logicChunkIndex)
+	}
+}
+
+func (up *UploadPipeline) moveToSealed(memChunk PageChunk, logicChunkIndex LogicChunkIndex) {
+	atomic.AddInt32(&up.uploaderCount, 1)
+	glog.V(4).Infof("%s uploaderCount %d ++> %d", up.filepath, up.uploaderCount-1, up.uploaderCount)
+
+	up.sealedChunksLock.Lock()
+
+	if oldMemChunk, found := up.sealedChunks[logicChunkIndex]; found {
+		oldMemChunk.FreeReference(fmt.Sprintf("%s replace chunk %d", up.filepath, logicChunkIndex))
+	}
+	sealedChunk := &SealedChunk{
+		chunk:            memChunk,
+		referenceCounter: 1, // default 1 is for uploading process
+	}
+	up.sealedChunks[logicChunkIndex] = sealedChunk
+	delete(up.writableChunks, logicChunkIndex)
+
+	up.sealedChunksLock.Unlock()
+
+	up.uploaders.Execute(func() {
+		// first add to the file chunks
+		sealedChunk.chunk.SaveContent(up.saveToStorageFn)
+
+		// notify waiting process
+		atomic.AddInt32(&up.uploaderCount, -1)
+		glog.V(4).Infof("%s uploaderCount %d --> %d", up.filepath, up.uploaderCount+1, up.uploaderCount)
+		// Lock and Unlock are not required,
+		// but it may signal multiple times during one wakeup,
+		// and the waiting goroutine may miss some of them!
+		up.uploaderCountCond.L.Lock()
+		up.uploaderCountCond.Broadcast()
+		up.uploaderCountCond.L.Unlock()
+
+		// wait for readers
+		for up.IsLocked(logicChunkIndex) {
+			time.Sleep(59 * time.Millisecond)
+		}
+
+		// then remove from sealed chunks
+		up.sealedChunksLock.Lock()
+		defer up.sealedChunksLock.Unlock()
+		delete(up.sealedChunks, logicChunkIndex)
+		sealedChunk.FreeReference(fmt.Sprintf("%s finished uploading chunk %d", up.filepath, logicChunkIndex))
+
+	})
+}
+
+func (up *UploadPipeline) Shutdown() {
+}
diff --git a/weed/mount/page_writer/upload_pipeline_lock.go b/weed/mount/page_writer/upload_pipeline_lock.go
new file mode 100644
index 000000000..47a40ba37
--- /dev/null
+++ b/weed/mount/page_writer/upload_pipeline_lock.go
@@ -0,0 +1,63 @@
+package page_writer
+
+import (
+	"sync/atomic"
+)
+
+func (up *UploadPipeline) LockForRead(startOffset, stopOffset int64) {
+	startLogicChunkIndex := LogicChunkIndex(startOffset / up.ChunkSize)
+	stopLogicChunkIndex := LogicChunkIndex(stopOffset / up.ChunkSize)
+	if stopOffset%up.ChunkSize > 0 {
+		stopLogicChunkIndex += 1
+	}
+	up.activeReadChunksLock.Lock()
+	defer up.activeReadChunksLock.Unlock()
+	for i := startLogicChunkIndex; i < stopLogicChunkIndex; i++ {
+		if count, found := up.activeReadChunks[i]; found {
+			up.activeReadChunks[i] = count + 1
+		} else {
+			up.activeReadChunks[i] = 1
+		}
+	}
+}
+
+func (up *UploadPipeline) UnlockForRead(startOffset, stopOffset int64) {
+	startLogicChunkIndex := LogicChunkIndex(startOffset / up.ChunkSize)
+	stopLogicChunkIndex := LogicChunkIndex(stopOffset / up.ChunkSize)
+	if stopOffset%up.ChunkSize > 0 {
+		stopLogicChunkIndex += 1
+	}
+	up.activeReadChunksLock.Lock()
+	defer up.activeReadChunksLock.Unlock()
+	for i := startLogicChunkIndex; i < stopLogicChunkIndex; i++ {
+		if count, found := up.activeReadChunks[i]; found {
+			if count == 1 {
+				delete(up.activeReadChunks, i)
+			} else {
+				up.activeReadChunks[i] = count - 1
+			}
+		}
+	}
+}
+
+func (up *UploadPipeline) IsLocked(logicChunkIndex LogicChunkIndex) bool {
+	up.activeReadChunksLock.Lock()
+	defer up.activeReadChunksLock.Unlock()
+	if count, found := up.activeReadChunks[logicChunkIndex]; found {
+		return count > 0
+	}
+	return false
+}
+
+func (up *UploadPipeline) waitForCurrentWritersToComplete() {
+	up.uploaderCountCond.L.Lock()
+	t := int32(100)
+	for {
+		t = atomic.LoadInt32(&up.uploaderCount)
+		if t <= 0 {
+			break
+		}
+		up.uploaderCountCond.Wait()
+	}
+	up.uploaderCountCond.L.Unlock()
+}
diff --git a/weed/mount/page_writer/upload_pipeline_test.go b/weed/mount/page_writer/upload_pipeline_test.go
new file mode 100644
index 000000000..816fb228b
--- /dev/null
+++ b/weed/mount/page_writer/upload_pipeline_test.go
@@ -0,0 +1,47 @@
+package page_writer
+
+import (
+	"github.com/chrislusf/seaweedfs/weed/util"
+	"testing"
+)
+
+func TestUploadPipeline(t *testing.T) {
+
+	uploadPipeline := NewUploadPipeline(nil, 2*1024*1024, nil, 16)
+
+	writeRange(uploadPipeline, 0, 131072)
+	writeRange(uploadPipeline, 131072, 262144)
+	writeRange(uploadPipeline, 262144, 1025536)
+
+	confirmRange(t, uploadPipeline, 0, 1025536)
+
+	writeRange(uploadPipeline, 1025536, 1296896)
+
+	confirmRange(t, uploadPipeline, 1025536, 1296896)
+
+	writeRange(uploadPipeline, 1296896, 2162688)
+
+	confirmRange(t, uploadPipeline, 1296896, 2162688)
+
+	confirmRange(t, uploadPipeline, 1296896, 2162688)
+}
+
+// startOff and stopOff must be divided by 4
+func writeRange(uploadPipeline *UploadPipeline, startOff, stopOff int64) {
+	p := make([]byte, 4)
+	for i := startOff / 4; i < stopOff/4; i += 4 {
+		util.Uint32toBytes(p, uint32(i))
+		uploadPipeline.SaveDataAt(p, i)
+	}
+}
+
+func confirmRange(t *testing.T, uploadPipeline *UploadPipeline, startOff, stopOff int64) {
+	p := make([]byte, 4)
+	for i := startOff; i < stopOff/4; i += 4 {
+		uploadPipeline.MaybeReadDataAt(p, i)
+		x := util.BytesToUint32(p)
+		if x != uint32(i) {
+			t.Errorf("expecting %d found %d at offset [%d,%d)", i, x, i, i+4)
+		}
+	}
+}
diff --git a/weed/mount/weedfs.go b/weed/mount/weedfs.go
index 1e9f07df9..b7f50cd13 100644
--- a/weed/mount/weedfs.go
+++ b/weed/mount/weedfs.go
@@ -2,14 +2,18 @@ package mount
 
 import (
 	"context"
+	"github.com/chrislusf/seaweedfs/weed/filer"
 	"github.com/chrislusf/seaweedfs/weed/filesys/meta_cache"
 	"github.com/chrislusf/seaweedfs/weed/pb"
 	"github.com/chrislusf/seaweedfs/weed/pb/filer_pb"
 	"github.com/chrislusf/seaweedfs/weed/storage/types"
 	"github.com/chrislusf/seaweedfs/weed/util"
+	"github.com/chrislusf/seaweedfs/weed/util/chunk_cache"
 	"github.com/chrislusf/seaweedfs/weed/util/grace"
+	"github.com/chrislusf/seaweedfs/weed/wdclient"
 	"github.com/hanwen/go-fuse/v2/fuse"
 	"google.golang.org/grpc"
+	"math/rand"
 	"os"
 	"path"
 	"path/filepath"
@@ -54,13 +58,15 @@ type WFS struct {
 	// follow https://github.com/hanwen/go-fuse/blob/master/fuse/api.go
 	fuse.RawFileSystem
 	fs.Inode
-	option      *Option
-	metaCache   *meta_cache.MetaCache
-	stats       statsCache
-	root        Directory
-	signature   int32
-	inodeToPath *InodeToPath
-	fhmap       *FileHandleToInode
+	option            *Option
+	metaCache         *meta_cache.MetaCache
+	stats             statsCache
+	root              Directory
+	chunkCache        *chunk_cache.TieredChunkCache
+	signature         int32
+	concurrentWriters *util.LimitedConcurrentExecutor
+	inodeToPath       *InodeToPath
+	fhmap             *FileHandleToInode
 }
 
 func NewSeaweedFileSystem(option *Option) *WFS {
@@ -79,12 +85,21 @@ func NewSeaweedFileSystem(option *Option) *WFS {
 		parent: nil,
 	}
 
+	wfs.option.filerIndex = rand.Intn(len(option.FilerAddresses))
+	wfs.option.setupUniqueCacheDirectory()
+	if option.CacheSizeMB > 0 {
+		wfs.chunkCache = chunk_cache.NewTieredChunkCache(256, option.getUniqueCacheDir(), option.CacheSizeMB, 1024*1024)
+	}
+
 	wfs.metaCache = meta_cache.NewMetaCache(path.Join(option.getUniqueCacheDir(), "meta"), util.FullPath(option.FilerMountRootPath), option.UidGidMapper, func(filePath util.FullPath, entry *filer_pb.Entry) {
 	})
 	grace.OnInterrupt(func() {
 		wfs.metaCache.Shutdown()
 	})
 
+	if wfs.option.ConcurrentWriters > 0 {
+		wfs.concurrentWriters = util.NewLimitedConcurrentExecutor(wfs.option.ConcurrentWriters)
+	}
 	return wfs
 }
 
@@ -132,6 +147,19 @@ func (wfs *WFS) maybeLoadEntry(fullpath util.FullPath) (*filer_pb.Entry, fuse.St
 	return cachedEntry.ToProtoEntry(), fuse.OK
 }
 
+func (wfs *WFS) LookupFn() wdclient.LookupFileIdFunctionType {
+	if wfs.option.VolumeServerAccess == "filerProxy" {
+		return func(fileId string) (targetUrls []string, err error) {
+			return []string{"http://" + wfs.getCurrentFiler().ToHttpAddress() + "/?proxyChunkId=" + fileId}, nil
+		}
+	}
+	return filer.LookupFn(wfs)
+}
+
+func (wfs *WFS) getCurrentFiler() pb.ServerAddress {
+	return wfs.option.FilerAddresses[wfs.option.filerIndex]
+}
+
 func (option *Option) setupUniqueCacheDirectory() {
 	cacheUniqueId := util.Md5String([]byte(option.MountDirectory + string(option.FilerAddresses[0]) + option.FilerMountRootPath + util.Version()))[0:8]
 	option.uniqueCacheDir = path.Join(option.CacheDir, cacheUniqueId)
diff --git a/weed/mount/weedfs_file_read.go b/weed/mount/weedfs_file_read.go
index d9ad1f4ea..00143a5b4 100644
--- a/weed/mount/weedfs_file_read.go
+++ b/weed/mount/weedfs_file_read.go
@@ -1,7 +1,9 @@
 package mount
 
 import (
+	"github.com/chrislusf/seaweedfs/weed/glog"
 	"github.com/hanwen/go-fuse/v2/fuse"
+	"io"
 )
 
 /**
@@ -29,6 +31,29 @@ import (
  * @param off offset to read from
  * @param fi file information
  */
-func (wfs *WFS) Read(cancel <-chan struct{}, in *fuse.ReadIn, buf []byte) (fuse.ReadResult, fuse.Status) {
-	return nil, fuse.ENOSYS
+func (wfs *WFS) Read(cancel <-chan struct{}, in *fuse.ReadIn, buff []byte) (fuse.ReadResult, fuse.Status) {
+	fh := wfs.GetHandle(FileHandleId(in.Fh))
+	if fh == nil {
+		return nil, fuse.ENOENT
+	}
+
+	offset := int64(in.Offset)
+	fh.lockForRead(offset, len(buff))
+	defer fh.unlockForRead(offset, len(buff))
+
+	totalRead, err := fh.readFromChunks(buff, offset)
+	if err == nil || err == io.EOF {
+		maxStop := fh.readFromDirtyPages(buff, offset)
+		totalRead = max(maxStop-offset, totalRead)
+	}
+	if err == io.EOF {
+		err = nil
+	}
+
+	if err != nil {
+		glog.Warningf("file handle read %s %d: %v", fh.FullPath(), totalRead, err)
+		return nil, fuse.EIO
+	}
+
+	return fuse.ReadResultData(buff[:totalRead]), fuse.OK
 }
diff --git a/weed/mount/weedfs_filehandle.go b/weed/mount/weedfs_filehandle.go
index 551394262..03f72282e 100644
--- a/weed/mount/weedfs_filehandle.go
+++ b/weed/mount/weedfs_filehandle.go
@@ -5,7 +5,7 @@ import "github.com/hanwen/go-fuse/v2/fuse"
 func (wfs *WFS) AcquireHandle(inode uint64, uid, gid uint32) (fileHandle *FileHandle, code fuse.Status) {
 	_, entry, status := wfs.maybeReadEntry(inode)
 	if status == fuse.OK {
-		fileHandle = wfs.fhmap.GetFileHandle(inode)
+		fileHandle = wfs.fhmap.AcquireFileHandle(wfs, inode, entry)
 		fileHandle.entry = entry
 	}
 	return
@@ -14,3 +14,7 @@ func (wfs *WFS) AcquireHandle(inode uint64, uid, gid uint32) (fileHandle *FileHa
 func (wfs *WFS) ReleaseHandle(handleId FileHandleId) {
 	wfs.fhmap.ReleaseByHandle(handleId)
 }
+
+func (wfs *WFS) GetHandle(handleId FileHandleId) *FileHandle {
+	return wfs.fhmap.GetFileHandle(handleId)
+}
diff --git a/weed/mount/weedfs_write.go b/weed/mount/weedfs_write.go
new file mode 100644
index 000000000..723ce9c34
--- /dev/null
+++ b/weed/mount/weedfs_write.go
@@ -0,0 +1,84 @@
+package mount
+
+import (
+	"context"
+	"fmt"
+	"io"
+
+	"github.com/chrislusf/seaweedfs/weed/filer"
+	"github.com/chrislusf/seaweedfs/weed/glog"
+	"github.com/chrislusf/seaweedfs/weed/operation"
+	"github.com/chrislusf/seaweedfs/weed/pb/filer_pb"
+	"github.com/chrislusf/seaweedfs/weed/security"
+	"github.com/chrislusf/seaweedfs/weed/util"
+)
+
+func (wfs *WFS) saveDataAsChunk(fullPath util.FullPath) filer.SaveDataAsChunkFunctionType {
+
+	return func(reader io.Reader, filename string, offset int64) (chunk *filer_pb.FileChunk, collection, replication string, err error) {
+		var fileId, host string
+		var auth security.EncodedJwt
+
+		if err := wfs.WithFilerClient(false, func(client filer_pb.SeaweedFilerClient) error {
+			return util.Retry("assignVolume", func() error {
+				request := &filer_pb.AssignVolumeRequest{
+					Count:       1,
+					Replication: wfs.option.Replication,
+					Collection:  wfs.option.Collection,
+					TtlSec:      wfs.option.TtlSec,
+					DiskType:    string(wfs.option.DiskType),
+					DataCenter:  wfs.option.DataCenter,
+					Path:        string(fullPath),
+				}
+
+				resp, err := client.AssignVolume(context.Background(), request)
+				if err != nil {
+					glog.V(0).Infof("assign volume failure %v: %v", request, err)
+					return err
+				}
+				if resp.Error != "" {
+					return fmt.Errorf("assign volume failure %v: %v", request, resp.Error)
+				}
+
+				fileId, auth = resp.FileId, security.EncodedJwt(resp.Auth)
+				loc := resp.Location
+				host = wfs.AdjustedUrl(loc)
+				collection, replication = resp.Collection, resp.Replication
+
+				return nil
+			})
+		}); err != nil {
+			return nil, "", "", fmt.Errorf("filerGrpcAddress assign volume: %v", err)
+		}
+
+		fileUrl := fmt.Sprintf("http://%s/%s", host, fileId)
+		if wfs.option.VolumeServerAccess == "filerProxy" {
+			fileUrl = fmt.Sprintf("http://%s/?proxyChunkId=%s", wfs.getCurrentFiler(), fileId)
+		}
+		uploadOption := &operation.UploadOption{
+			UploadUrl:         fileUrl,
+			Filename:          filename,
+			Cipher:            wfs.option.Cipher,
+			IsInputCompressed: false,
+			MimeType:          "",
+			PairMap:           nil,
+			Jwt:               auth,
+		}
+		uploadResult, err, data := operation.Upload(reader, uploadOption)
+		if err != nil {
+			glog.V(0).Infof("upload data %v to %s: %v", filename, fileUrl, err)
+			return nil, "", "", fmt.Errorf("upload data: %v", err)
+		}
+		if uploadResult.Error != "" {
+			glog.V(0).Infof("upload failure %v to %s: %v", filename, fileUrl, err)
+			return nil, "", "", fmt.Errorf("upload result: %v", uploadResult.Error)
+		}
+
+		if offset == 0 {
+			wfs.chunkCache.SetChunk(fileId, data)
+		}
+
+		chunk = uploadResult.ToPbFileChunk(fileId, offset)
+		return chunk, collection, replication, nil
+	}
+}