mount: rewrite ReadDir to respect input.Offset to fix partial results

weed/mount/weedfs_dir_read.go

@@ -12,9 +12,22 @@ import (
 
 type DirectoryHandleId uint64
 
+const (
+	directoryStreamBaseOffset = 2 // . & ..
+)
+
 type DirectoryHandle struct {
-	isFinished    bool
-	lastEntryName string
+	isFinished        bool
+	entryStream       []*filer.Entry
+	entryStreamOffset uint64
+}
+
+func (dh *DirectoryHandle) reset() {
+	*dh = DirectoryHandle{
+		isFinished:        false,
+		entryStream:       []*filer.Entry{},
+		entryStreamOffset: directoryStreamBaseOffset,
+	}
 }
 
 type DirectoryHandleToInode struct {
@@ -37,10 +50,8 @@ func (wfs *WFS) AcquireDirectoryHandle() (DirectoryHandleId, *DirectoryHandle) {
 
 	wfs.dhmap.Lock()
 	defer wfs.dhmap.Unlock()
-	dh := &DirectoryHandle{
-		isFinished:    false,
-		lastEntryName: "",
-	}
+	dh := new(DirectoryHandle)
+	dh.reset()
 	wfs.dhmap.dir2inode[DirectoryHandleId(fh)] = dh
 	return DirectoryHandleId(fh), dh
 }
@@ -51,11 +62,8 @@ func (wfs *WFS) GetDirectoryHandle(dhid DirectoryHandleId) *DirectoryHandle {
 	if dh, found := wfs.dhmap.dir2inode[dhid]; found {
 		return dh
 	}
-	dh := &DirectoryHandle{
-		isFinished:    false,
-		lastEntryName: "",
-	}
-
+	dh := new(DirectoryHandle)
+	dh.reset()
 	wfs.dhmap.dir2inode[dhid] = dh
 	return dh
 }
@@ -130,13 +138,12 @@ func (wfs *WFS) ReadDirPlus(cancel <-chan struct{}, input *fuse.ReadIn, out *fus
 }
 
 func (wfs *WFS) doReadDirectory(input *fuse.ReadIn, out *fuse.DirEntryList, isPlusMode bool) fuse.Status {
-
 	dh := wfs.GetDirectoryHandle(DirectoryHandleId(input.Fh))
 	if input.Offset == 0 {
-		dh.isFinished = false
-		dh.lastEntryName = ""
-	} else {
-		if dh.isFinished {
+		dh.reset()
+	} else if dh.isFinished && input.Offset >= directoryStreamBaseOffset {
+		entryCurrentIndex := input.Offset - dh.entryStreamOffset
+		if uint64(len(dh.entryStream)) <= entryCurrentIndex {
 			return fuse.OK
 		}
 	}
@@ -148,29 +155,17 @@ func (wfs *WFS) doReadDirectory(input *fuse.ReadIn, out *fuse.DirEntryList, isPl
 	}
 
 	var dirEntry fuse.DirEntry
-	if input.Offset == 0 {
-		if !isPlusMode {
-			out.AddDirEntry(fuse.DirEntry{Mode: fuse.S_IFDIR, Name: "."})
-			out.AddDirEntry(fuse.DirEntry{Mode: fuse.S_IFDIR, Name: ".."})
-		} else {
-			out.AddDirLookupEntry(fuse.DirEntry{Mode: fuse.S_IFDIR, Name: "."})
-			out.AddDirLookupEntry(fuse.DirEntry{Mode: fuse.S_IFDIR, Name: ".."})
-		}
-	}
-
-	processEachEntryFn := func(entry *filer.Entry, isLast bool) bool {
+	processEachEntryFn := func(entry *filer.Entry) bool {
 		dirEntry.Name = entry.Name()
 		dirEntry.Mode = toSyscallMode(entry.Mode)
+		inode := wfs.inodeToPath.Lookup(dirPath.Child(dirEntry.Name), entry.Crtime.Unix(), entry.IsDirectory(), len(entry.HardLinkId) > 0, entry.Inode, isPlusMode)
+		dirEntry.Ino = inode
 		if !isPlusMode {
-			inode := wfs.inodeToPath.Lookup(dirPath.Child(dirEntry.Name), entry.Crtime.Unix(), entry.IsDirectory(), len(entry.HardLinkId) > 0, entry.Inode, false)
-			dirEntry.Ino = inode
 			if !out.AddDirEntry(dirEntry) {
 				isEarlyTerminated = true
 				return false
 			}
 		} else {
-			inode := wfs.inodeToPath.Lookup(dirPath.Child(dirEntry.Name), entry.Crtime.Unix(), entry.IsDirectory(), len(entry.HardLinkId) > 0, entry.Inode, true)
-			dirEntry.Ino = inode
 			entryOut := out.AddDirLookupEntry(dirEntry)
 			if entryOut == nil {
 				isEarlyTerminated = true
@@ -182,37 +177,60 @@ func (wfs *WFS) doReadDirectory(input *fuse.ReadIn, out *fuse.DirEntryList, isPl
 			}
 			wfs.outputFilerEntry(entryOut, inode, entry)
 		}
-		dh.lastEntryName = entry.Name()
 		return true
 	}
 
-	entryChan := make(chan *filer.Entry, 128)
-	var err error
-	go func() {
-		if err = meta_cache.EnsureVisited(wfs.metaCache, wfs, dirPath, entryChan); err != nil {
-			glog.Errorf("dir ReadDirAll %s: %v", dirPath, err)
+	if input.Offset < directoryStreamBaseOffset {
+		if !isPlusMode {
+			if input.Offset == 0 {
+				out.AddDirEntry(fuse.DirEntry{Mode: fuse.S_IFDIR, Name: "."})
+			}
+			out.AddDirEntry(fuse.DirEntry{Mode: fuse.S_IFDIR, Name: ".."})
+		} else {
+			if input.Offset == 0 {
+				out.AddDirLookupEntry(fuse.DirEntry{Mode: fuse.S_IFDIR, Name: "."})
+			}
+			out.AddDirLookupEntry(fuse.DirEntry{Mode: fuse.S_IFDIR, Name: ".."})
 		}
-		close(entryChan)
-	}()
-	hasData := false
-	for entry := range entryChan {
-		hasData = true
-		processEachEntryFn(entry, false)
-	}
-	if err != nil {
-		return fuse.EIO
+		input.Offset = directoryStreamBaseOffset
 	}
 
-	if !hasData {
-		listErr := wfs.metaCache.ListDirectoryEntries(context.Background(), dirPath, dh.lastEntryName, false, int64(math.MaxInt32), func(entry *filer.Entry) bool {
-			return processEachEntryFn(entry, false)
-		})
-		if listErr != nil {
-			glog.Errorf("list meta cache: %v", listErr)
-			return fuse.EIO
+	var lastEntryName string
+	if input.Offset >= directoryStreamBaseOffset {
+		if input.Offset > directoryStreamBaseOffset {
+			entryPreviousIndex := (input.Offset - dh.entryStreamOffset) - 1
+			if uint64(len(dh.entryStream)) > entryPreviousIndex {
+				lastEntryName = dh.entryStream[entryPreviousIndex].Name()
+				dh.entryStream = dh.entryStream[entryPreviousIndex:]
+				dh.entryStreamOffset = input.Offset - 1
+			}
+		}
+		entryCurrentIndex := input.Offset - dh.entryStreamOffset
+		for uint64(len(dh.entryStream)) > entryCurrentIndex {
+			entry := dh.entryStream[entryCurrentIndex]
+			if processEachEntryFn(entry) {
+				lastEntryName = entry.Name()
+				entryCurrentIndex++
+			} else {
+				// early terminated
+				return fuse.OK
+			}
 		}
 	}
 
+	var err error
+	if err = meta_cache.EnsureVisited(wfs.metaCache, wfs, dirPath, nil); err != nil {
+		glog.Errorf("dir ReadDirAll %s: %v", dirPath, err)
+	}
+	listErr := wfs.metaCache.ListDirectoryEntries(context.Background(), dirPath, lastEntryName, false, int64(math.MaxInt32), func(entry *filer.Entry) bool {
+		dh.entryStream = append(dh.entryStream, entry)
+		return processEachEntryFn(entry)
+	})
+	if listErr != nil {
+		glog.Errorf("list meta cache: %v", listErr)
+		return fuse.EIO
+	}
+
 	if !isEarlyTerminated {
 		dh.isFinished = true
 	}