Fix volume.fsck -forcePurging -reallyDeleteFromVolume to fail fast on filer traversal errors (#8015)

* Add TraverseBfsWithContext and fix race conditions in error handling

- Add TraverseBfsWithContext function to support context cancellation
- Fix race condition in doTraverseBfsAndSaving using atomic.Bool and sync.Once
- Improve error handling with fail-fast behavior and proper error propagation
- Update command_volume_fsck to use error-returning saveFn callback
- Enhance error messages in readFilerFileIdFile with detailed context

* refactoring

* fix error format

* atomic

* filer_pb: make enqueue return void

* shell: simplify fs.meta.save error handling

* filer_pb: handle enqueue return value

* Revert "atomic"

This reverts commit 712648bc35.

* shell: refine fs.meta.save logic

---------

Co-authored-by: Chris Lu <chris.lu@gmail.com>

weed/command/filer_meta_backup.go

@@ -157,26 +157,18 @@ func (metaBackup *FilerMetaBackupOptions) shouldInclude(fullpath string) bool {
 }
 
 func (metaBackup *FilerMetaBackupOptions) traverseMetadata() (err error) {
-	var saveErr error
-
-	traverseErr := filer_pb.TraverseBfs(metaBackup, util.FullPath(*metaBackup.filerDirectory), func(parentPath util.FullPath, entry *filer_pb.Entry) {
+	return filer_pb.TraverseBfs(context.Background(), metaBackup, util.FullPath(*metaBackup.filerDirectory), func(parentPath util.FullPath, entry *filer_pb.Entry) error {
 		fullpath := string(parentPath.Child(entry.Name))
 		if !metaBackup.shouldInclude(fullpath) {
-			return
+			return nil
 		}
 
 		println("+", fullpath)
 		if err := metaBackup.store.InsertEntry(context.Background(), filer.FromPbEntry(string(parentPath), entry)); err != nil {
-			saveErr = fmt.Errorf("insert entry error: %w\n", err)
-			return
+			return fmt.Errorf("insert entry error: %w", err)
 		}
-
+		return nil
 	})
-
-	if traverseErr != nil {
-		return fmt.Errorf("traverse: %w", traverseErr)
-	}
-	return saveErr
 }
 
 var (

weed/pb/filer_pb/filer_client_bfs.go

@@ -12,58 +12,93 @@ import (
 	"github.com/seaweedfs/seaweedfs/weed/util"
 )
 
-func TraverseBfs(filerClient FilerClient, parentPath util.FullPath, fn func(parentPath util.FullPath, entry *Entry)) (err error) {
+func TraverseBfs(ctx context.Context, filerClient FilerClient, parentPath util.FullPath, fn func(parentPath util.FullPath, entry *Entry) error) (err error) {
 	K := 5
 
-	var jobQueueWg sync.WaitGroup
+	ctx, cancel := context.WithCancel(ctx)
+	defer cancel()
+
 	queue := util.NewQueue[util.FullPath]()
-	jobQueueWg.Add(1)
+	var pending sync.WaitGroup
+	pending.Add(1)
 	queue.Enqueue(parentPath)
-	terminates := make([]chan bool, K)
 
+	var once sync.Once
+	var firstErr error
+
+	enqueue := func(p util.FullPath) bool {
+		// Stop expanding traversal once canceled (e.g. first error encountered).
+		if ctx.Err() != nil {
+			return false
+		}
+		pending.Add(1)
+		queue.Enqueue(p)
+		return true
+	}
+
+	done := make(chan struct{})
+	var workers sync.WaitGroup
 	for i := 0; i < K; i++ {
-		terminates[i] = make(chan bool)
-		go func(j int) {
+		workers.Add(1)
+		go func() {
+			defer workers.Done()
 			for {
 				select {
-				case <-terminates[j]:
+				case <-done:
 					return
 				default:
-					t := queue.Dequeue()
-					if t == "" {
-						time.Sleep(329 * time.Millisecond)
+				}
+
+				dir := queue.Dequeue()
+				if dir == "" {
+					// queue is empty for now
+					select {
+					case <-done:
+						return
+					case <-time.After(50 * time.Millisecond):
 						continue
 					}
-					dir := t
-					processErr := processOneDirectory(filerClient, dir, queue, &jobQueueWg, fn)
+				}
+
+				// Always mark the directory as done so the closer can finish.
+				if ctx.Err() == nil {
+					processErr := processOneDirectory(ctx, filerClient, dir, enqueue, fn)
 					if processErr != nil {
-						err = processErr
+						once.Do(func() {
+							firstErr = processErr
+							cancel()
+						})
 					}
-					jobQueueWg.Done()
 				}
+				pending.Done()
 			}
-		}(i)
-	}
-	jobQueueWg.Wait()
-	for i := 0; i < K; i++ {
-		close(terminates[i])
+		}()
 	}
-	return
+
+	pending.Wait()
+	close(done)
+
+	workers.Wait()
+
+	return firstErr
 }
 
-func processOneDirectory(filerClient FilerClient, parentPath util.FullPath, queue *util.Queue[util.FullPath], jobQueueWg *sync.WaitGroup, fn func(parentPath util.FullPath, entry *Entry)) (err error) {
+func processOneDirectory(ctx context.Context, filerClient FilerClient, parentPath util.FullPath, enqueue func(p util.FullPath) bool, fn func(parentPath util.FullPath, entry *Entry) error) (err error) {
 
-	return ReadDirAllEntries(context.Background(), filerClient, parentPath, "", func(entry *Entry, isLast bool) error {
+	return ReadDirAllEntries(ctx, filerClient, parentPath, "", func(entry *Entry, isLast bool) error {
 
-		fn(parentPath, entry)
+		if err := fn(parentPath, entry); err != nil {
+			return err
+		}
 
 		if entry.IsDirectory {
 			subDir := fmt.Sprintf("%s/%s", parentPath, entry.Name)
 			if parentPath == "/" {
 				subDir = "/" + entry.Name
 			}
-			jobQueueWg.Add(1)
-			queue.Enqueue(util.FullPath(subDir))
+			if !enqueue(util.FullPath(subDir)) {
+				return ctx.Err()
+			}
 		}
 		return nil
 	})

weed/shell/command_fs_merge_volumes.go

@@ -109,9 +109,9 @@ func (c *commandFsMergeVolumes) Do(args []string, commandEnv *CommandEnv, writer
 	defer util_http.GetGlobalHttpClient().CloseIdleConnections()
 
 	return commandEnv.WithFilerClient(false, func(filerClient filer_pb.SeaweedFilerClient) error {
-		return filer_pb.TraverseBfs(commandEnv, util.FullPath(dir), func(parentPath util.FullPath, entry *filer_pb.Entry) {
+		return filer_pb.TraverseBfs(context.Background(), commandEnv, util.FullPath(dir), func(parentPath util.FullPath, entry *filer_pb.Entry) error {
 			if entry.IsDirectory {
-				return
+				return nil
 			}
 			for _, chunk := range entry.Chunks {
 				chunkVolumeId := needle.VolumeId(chunk.Fid.VolumeId)
@@ -141,6 +141,7 @@ func (c *commandFsMergeVolumes) Do(args []string, commandEnv *CommandEnv, writer
 					fmt.Printf("failed to update %s: %v\n", path, err)
 				}
 			}
+			return nil
 		})
 	})
 }

weed/shell/command_fs_meta_change_volume_id.go

@@ -75,13 +75,13 @@ func (c *commandFsMetaChangeVolumeId) Do(args []string, commandEnv *CommandEnv,
 	}
 
 	return commandEnv.WithFilerClient(false, func(client filer_pb.SeaweedFilerClient) error {
-		return filer_pb.TraverseBfs(commandEnv, util.FullPath(*dir), func(parentPath util.FullPath, entry *filer_pb.Entry) {
+		return filer_pb.TraverseBfs(context.Background(), commandEnv, util.FullPath(*dir), func(parentPath util.FullPath, entry *filer_pb.Entry) error {
 			if !entry.IsDirectory {
 				var hasChanges bool
 				for _, chunk := range entry.Chunks {
 					if chunk.IsChunkManifest {
 						fmt.Printf("Change volume id for large file is not implemented yet: %s/%s\n", parentPath, entry.Name)
-						return
+						return nil
 					}
 					chunkVolumeId := chunk.Fid.VolumeId
 					if toVolumeId, found := mapping[needle.VolumeId(chunkVolumeId)]; found {
@@ -102,6 +102,7 @@ func (c *commandFsMetaChangeVolumeId) Do(args []string, commandEnv *CommandEnv,
 					}
 				}
 			}
+			return nil
 		})
 	})
 }

weed/shell/command_fs_meta_notify.go

@@ -1,6 +1,7 @@
 package shell
 
 import (
+	"context"
 	"fmt"
 	"io"
 
@@ -51,7 +52,7 @@ func (c *commandFsMetaNotify) Do(args []string, commandEnv *CommandEnv, writer i
 
 	var dirCount, fileCount uint64
 
-	err = filer_pb.TraverseBfs(commandEnv, util.FullPath(path), func(parentPath util.FullPath, entry *filer_pb.Entry) {
+	err = filer_pb.TraverseBfs(context.Background(), commandEnv, util.FullPath(path), func(parentPath util.FullPath, entry *filer_pb.Entry) error {
 
 		if entry.IsDirectory {
 			dirCount++
@@ -69,7 +70,7 @@ func (c *commandFsMetaNotify) Do(args []string, commandEnv *CommandEnv, writer i
 		if notifyErr != nil {
 			fmt.Fprintf(writer, "fail to notify new entry event for %s: %v\n", parentPath.Child(entry.Name), notifyErr)
 		}
-
+		return nil
 	})
 
 	if err == nil {

weed/shell/command_fs_meta_save.go

@@ -118,14 +118,21 @@ func (c *commandFsMetaSave) Do(args []string, commandEnv *CommandEnv, writer io.
 
 		outputChan <- bytes
 		return nil
-	}, func(outputChan chan interface{}) {
+	}, func(outputChan chan interface{}) error {
 		sizeBuf := make([]byte, 4)
 		for item := range outputChan {
 			b := item.([]byte)
 			util.Uint32toBytes(sizeBuf, uint32(len(b)))
-			dst.Write(sizeBuf)
-			dst.Write(b)
+			_, err := dst.Write(sizeBuf)
+			if err != nil {
+				return err
+			}
+			_, err = dst.Write(b)
+			if err != nil {
+				return err
+			}
 		}
+		return nil
 	})
 
 	if err == nil {
@@ -136,17 +143,21 @@ func (c *commandFsMetaSave) Do(args []string, commandEnv *CommandEnv, writer io.
 
 }
 
-func doTraverseBfsAndSaving(filerClient filer_pb.FilerClient, writer io.Writer, path string, verbose bool, genFn func(entry *filer_pb.FullEntry, outputChan chan interface{}) error, saveFn func(outputChan chan interface{})) error {
+func doTraverseBfsAndSaving(filerClient filer_pb.FilerClient, writer io.Writer, path string, verbose bool, genFn func(entry *filer_pb.FullEntry, outputChan chan interface{}) error, saveFn func(outputChan chan interface{}) error) error {
 
 	var wg sync.WaitGroup
 	wg.Add(1)
 	outputChan := make(chan interface{}, 1024)
+	saveErrChan := make(chan error, 1)
 	go func() {
-		saveFn(outputChan)
+		saveErrChan <- saveFn(outputChan)
 		wg.Done()
 	}()
 
 	var dirCount, fileCount uint64
+	var once sync.Once
+	var firstErr error
+	var hasErr atomic.Bool
 
 	// also save the directory itself (path) if it exists in the filer
 	if e, getErr := filer_pb.GetEntry(context.Background(), filerClient, util.FullPath(path)); getErr != nil {
@@ -160,8 +171,13 @@ func doTraverseBfsAndSaving(filerClient filer_pb.FilerClient, writer io.Writer,
 			Dir:   parentDir,
 			Entry: e,
 		}
+
 		if genErr := genFn(protoMessage, outputChan); genErr != nil {
-			fmt.Fprintf(writer, "marshall error: %v\n", genErr)
+			once.Do(func() {
+				firstErr = genErr
+				hasErr.Store(true)
+			})
+			return genErr
 		} else {
 			if e.IsDirectory {
 				atomic.AddUint64(&dirCount, 1)
@@ -171,10 +187,13 @@ func doTraverseBfsAndSaving(filerClient filer_pb.FilerClient, writer io.Writer,
 		}
 	}
 
-	err := filer_pb.TraverseBfs(filerClient, util.FullPath(path), func(parentPath util.FullPath, entry *filer_pb.Entry) {
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+	err := filer_pb.TraverseBfs(ctx, filerClient, util.FullPath(path), func(parentPath util.FullPath, entry *filer_pb.Entry) error {
 
-		if strings.HasPrefix(string(parentPath), filer.SystemLogDir) {
-			return
+		parent := string(parentPath)
+		if parent == filer.SystemLogDir || strings.HasPrefix(parent, filer.SystemLogDir+"/") {
+			return nil
 		}
 
 		protoMessage := &filer_pb.FullEntry{
@@ -182,9 +201,17 @@ func doTraverseBfsAndSaving(filerClient filer_pb.FilerClient, writer io.Writer,
 			Entry: entry,
 		}
 
-		if err := genFn(protoMessage, outputChan); err != nil {
-			fmt.Fprintf(writer, "marshall error: %v\n", err)
-			return
+		if hasErr.Load() {
+			// fail-fast: stop traversal once an error is observed.
+			return firstErr
+		}
+		if genErr := genFn(protoMessage, outputChan); genErr != nil {
+			once.Do(func() {
+				firstErr = genErr
+				hasErr.Store(true)
+				cancel()
+			})
+			return genErr
 		}
 
 		if entry.IsDirectory {
@@ -197,14 +224,23 @@ func doTraverseBfsAndSaving(filerClient filer_pb.FilerClient, writer io.Writer,
 			println(parentPath.Child(entry.Name))
 		}
 
+		return nil
 	})
 
 	close(outputChan)
 
 	wg.Wait()
+	saveErr := <-saveErrChan
 
-	if err == nil && writer != nil {
+	if err != nil {
+		return err
+	}
+	if saveErr != nil {
+		return saveErr
+	}
+
+	if writer != nil {
 		fmt.Fprintf(writer, "total %d directories, %d files\n", dirCount, fileCount)
 	}
-	return err
+	return nil
 }

weed/shell/command_fs_verify.go

@@ -300,7 +300,7 @@ func (c *commandFsVerify) verifyTraverseBfs(path string) (fileCount uint64, errC
 			}
 			return nil
 		},
-		func(outputChan chan interface{}) {
+		func(outputChan chan interface{}) error {
 			var wg sync.WaitGroup
 			itemErrCount := atomic.NewUint64(0)
 			for itemEntry := range outputChan {
@@ -315,5 +315,6 @@ func (c *commandFsVerify) verifyTraverseBfs(path string) (fileCount uint64, errC
 			}
 			wg.Wait()
 			errCount = itemErrCount.Load()
+			return nil
 		})
 }

weed/shell/command_volume_fsck.go

@@ -266,7 +266,7 @@ func (c *commandVolumeFsck) collectFilerFileIdAndPaths(dataNodeVolumeIdToVInfo m
 			}
 			return nil
 		},
-		func(outputChan chan interface{}) {
+		func(outputChan chan interface{}) error {
 			buffer := make([]byte, readbufferSize)
 			for item := range outputChan {
 				i := item.(*Item)
@@ -274,8 +274,12 @@ func (c *commandVolumeFsck) collectFilerFileIdAndPaths(dataNodeVolumeIdToVInfo m
 					util.Uint64toBytes(buffer, i.fileKey)
 					util.Uint32toBytes(buffer[8:], i.cookie)
 					util.Uint32toBytes(buffer[12:], uint32(len(i.path)))
-					f.Write(buffer)
-					f.Write([]byte(i.path))
+					if _, err := f.Write(buffer); err != nil {
+						return err
+					}
+					if _, err := f.Write([]byte(i.path)); err != nil {
+						return err
+					}
 				} else if *c.findMissingChunksInFiler && len(c.volumeIds) == 0 {
 					fmt.Fprintf(c.writer, "%d,%x%08x %s volume not found\n", i.vid, i.fileKey, i.cookie, i.path)
 					if purgeAbsent {
@@ -284,6 +288,7 @@ func (c *commandVolumeFsck) collectFilerFileIdAndPaths(dataNodeVolumeIdToVInfo m
 					}
 				}
 			}
+			return nil
 		})
 }
 
@@ -482,10 +487,10 @@ func (c *commandVolumeFsck) readFilerFileIdFile(volumeId uint32, fn func(needleI
 			break
 		}
 		if readErr != nil {
-			return readErr
+			return fmt.Errorf("read fid header for volume %d: %w", volumeId, readErr)
 		}
 		if readSize != readbufferSize {
-			return fmt.Errorf("readSize mismatch")
+			return fmt.Errorf("read fid header size mismatch for volume %d: got %d want %d", volumeId, readSize, readbufferSize)
 		}
 		item.fileKey = util.BytesToUint64(buffer[:8])
 		item.cookie = util.BytesToUint32(buffer[8:12])
@@ -493,10 +498,10 @@ func (c *commandVolumeFsck) readFilerFileIdFile(volumeId uint32, fn func(needleI
 		pathBytes := make([]byte, int(pathSize))
 		n, err := io.ReadFull(br, pathBytes)
 		if err != nil {
-			fmt.Fprintf(c.writer, "%d,%x%08x in unexpected error: %v\n", volumeId, item.fileKey, item.cookie, err)
+			return fmt.Errorf("read fid path for volume %d,%x%08x: %w", volumeId, item.fileKey, item.cookie, err)
 		}
 		if n != int(pathSize) {
-			fmt.Fprintf(c.writer, "%d,%x%08x %d unexpected file name size %d\n", volumeId, item.fileKey, item.cookie, pathSize, n)
+			return fmt.Errorf("read fid path size mismatch for volume %d,%x%08x: got %d want %d", volumeId, item.fileKey, item.cookie, n, pathSize)
 		}
 		item.path = util.FullPath(pathBytes)
 		needleId := types.NeedleId(item.fileKey)
@@ -748,10 +753,10 @@ func writeToFile(bytes []byte, fileName string) error {
 	flags := os.O_WRONLY | os.O_CREATE | os.O_TRUNC
 	dst, err := os.OpenFile(fileName, flags, 0644)
 	if err != nil {
-		return nil
+		return err
 	}
 	defer dst.Close()
 
-	dst.Write(bytes)
-	return nil
+	_, err = dst.Write(bytes)
+	return err
 }