fix nfs list with prefix batch scan (#7694)

* fix nfs list with prefix batch scan

* remove else branch

weed/mount/weedfs_dir_read.go

@@ -2,7 +2,6 @@ package mount
 
 import (
 	"context"
-	"math"
 	"sync"
 
 	"github.com/hanwen/go-fuse/v2/fuse"
@@ -16,6 +15,7 @@ type DirectoryHandleId uint64
 
 const (
 	directoryStreamBaseOffset = 2 // . & ..
+	batchSize                 = 1000
 )
 
 // DirectoryHandle represents an open directory handle.
@@ -166,11 +166,17 @@ func (wfs *WFS) doReadDirectory(input *fuse.ReadIn, out *fuse.DirEntryList, isPl
 	}
 
 	var dirEntry fuse.DirEntry
-	processEachEntryFn := func(entry *filer.Entry) bool {
+
+	// index is the position in entryStream, used to calculate the offset for next readdir
+	processEachEntryFn := func(entry *filer.Entry, index int64) 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, false)
 		dirEntry.Ino = inode
+
+		// Set Off to the next offset so client can resume from correct position
+		dirEntry.Off = dh.entryStreamOffset + uint64(index) + 1
+
 		if !isPlusMode {
 			if !out.AddDirEntry(dirEntry) {
 				isEarlyTerminated = true
@@ -195,59 +201,92 @@ func (wfs *WFS) doReadDirectory(input *fuse.ReadIn, out *fuse.DirEntryList, isPl
 	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: ".", Off: 1})
 			}
-			out.AddDirEntry(fuse.DirEntry{Mode: fuse.S_IFDIR, Name: ".."})
+			out.AddDirEntry(fuse.DirEntry{Mode: fuse.S_IFDIR, Name: "..", Off: 2})
 		} else {
 			if input.Offset == 0 {
-				out.AddDirLookupEntry(fuse.DirEntry{Mode: fuse.S_IFDIR, Name: "."})
+				out.AddDirLookupEntry(fuse.DirEntry{Mode: fuse.S_IFDIR, Name: ".", Off: 1})
 			}
-			out.AddDirLookupEntry(fuse.DirEntry{Mode: fuse.S_IFDIR, Name: ".."})
+			out.AddDirLookupEntry(fuse.DirEntry{Mode: fuse.S_IFDIR, Name: "..", Off: 2})
 		}
 		input.Offset = directoryStreamBaseOffset
 	}
 
 	var lastEntryName string
+
+	// Read from cache first, then load next batch if needed
 	if input.Offset >= dh.entryStreamOffset {
+		// Handle case: new handle with non-zero offset but empty cache
+		// This happens when NFS-Ganesha opens multiple directory handles
+		if len(dh.entryStream) == 0 && input.Offset > dh.entryStreamOffset {
+			skipCount := int64(input.Offset - dh.entryStreamOffset)
+
+			if err := meta_cache.EnsureVisited(wfs.metaCache, wfs, dirPath); err != nil {
+				glog.Errorf("dir ReadDirAll %s: %v", dirPath, err)
+				return fuse.EIO
+			}
+
+			// Load entries from beginning to fill cache up to the requested offset
+			loadErr := wfs.metaCache.ListDirectoryEntries(context.Background(), dirPath, "", false, skipCount+int64(batchSize), func(entry *filer.Entry) (bool, error) {
+				dh.entryStream = append(dh.entryStream, entry)
+				return true, nil
+			})
+			if loadErr != nil {
+				glog.Errorf("list meta cache: %v", loadErr)
+				return fuse.EIO
+			}
+		}
+
 		if input.Offset > dh.entryStreamOffset {
 			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 {
+
+		entryCurrentIndex := int64(input.Offset - dh.entryStreamOffset)
+		for int64(len(dh.entryStream)) > entryCurrentIndex {
 			entry := dh.entryStream[entryCurrentIndex]
-			if processEachEntryFn(entry) {
+			if processEachEntryFn(entry, entryCurrentIndex) {
 				lastEntryName = entry.Name()
 				entryCurrentIndex++
 			} else {
-				// early terminated
 				return fuse.OK
 			}
 		}
-	}
 
-	if err := meta_cache.EnsureVisited(wfs.metaCache, wfs, dirPath); err != nil {
-		glog.Errorf("dir ReadDirAll %s: %v", dirPath, err)
-		return fuse.EIO
-	}
-	listErr := wfs.metaCache.ListDirectoryEntries(context.Background(), dirPath, lastEntryName, false, int64(math.MaxInt32), func(entry *filer.Entry) (bool, error) {
-		dh.entryStream = append(dh.entryStream, entry)
-		if !processEachEntryFn(entry) {
-			return false, nil
-		}
-		return true, nil
-	})
-	if listErr != nil {
-		glog.Errorf("list meta cache: %v", listErr)
-		return fuse.EIO
-	}
+		// Cache exhausted, load next batch
+		if !isEarlyTerminated {
+			if err := meta_cache.EnsureVisited(wfs.metaCache, wfs, dirPath); err != nil {
+				glog.Errorf("dir ReadDirAll %s: %v", dirPath, err)
+				return fuse.EIO
+			}
+
+			// Batch loading: fetch batchSize entries starting from lastEntryName
+			loadedCount := 0
+			bufferFull := false
+			loadErr := wfs.metaCache.ListDirectoryEntries(context.Background(), dirPath, lastEntryName, false, int64(batchSize), func(entry *filer.Entry) (bool, error) {
+				currentIndex := int64(len(dh.entryStream))
+				dh.entryStream = append(dh.entryStream, entry)
+				loadedCount++
+				if !processEachEntryFn(entry, currentIndex) {
+					bufferFull = true
+					return false, nil
+				}
+				return true, nil
+			})
+			if loadErr != nil {
+				glog.Errorf("list meta cache: %v", loadErr)
+				return fuse.EIO
+			}
 
-	if !isEarlyTerminated {
-		dh.isFinished = true
+			// Mark finished only when loading completed normally (not buffer full)
+			// and we got fewer entries than requested
+			if !bufferFull && loadedCount < batchSize {
+				dh.isFinished = true
+			}
+		}
 	}
 
 	return fuse.OK