From 6e8dbf8868c8c5f32a82e89985984758b10a16e5 Mon Sep 17 00:00:00 2001
From: chrislu <chris.lu@gmail.com>
Date: Sun, 29 Jan 2023 22:51:58 -0800
Subject: [PATCH] add fs.meta.changeVolumeId

---
 .../shell/command_fs_meta_change_volume_id.go | 121 ++++++++++++++++++
 1 file changed, 121 insertions(+)
 create mode 100644 weed/shell/command_fs_meta_change_volume_id.go

diff --git a/weed/shell/command_fs_meta_change_volume_id.go b/weed/shell/command_fs_meta_change_volume_id.go
new file mode 100644
index 000000000..c11c5092f
--- /dev/null
+++ b/weed/shell/command_fs_meta_change_volume_id.go
@@ -0,0 +1,121 @@
+package shell
+
+import (
+	"flag"
+	"fmt"
+	"github.com/seaweedfs/seaweedfs/weed/pb/filer_pb"
+	"github.com/seaweedfs/seaweedfs/weed/storage/needle"
+	"github.com/seaweedfs/seaweedfs/weed/util"
+	"io"
+	"os"
+	"strconv"
+	"strings"
+)
+
+func init() {
+	Commands = append(Commands, &commandFsMetaChangeVolumeId{})
+}
+
+type commandFsMetaChangeVolumeId struct {
+}
+
+func (c *commandFsMetaChangeVolumeId) Name() string {
+	return "fs.meta.changeVolumeId"
+}
+
+func (c *commandFsMetaChangeVolumeId) Help() string {
+	return `change volume id in existing metadata.
+
+	fs.meta.changeVolumeId -dir=/path/to/a/dir -fromVolumeId=x -toVolumeId=y -force
+	fs.meta.changeVolumeId -dir=/path/to/a/dir -mapping=/path/to/mapping/file -force
+
+	The mapping file should have these lines, each line is: [fromVolumeId]=>[toVolumeId]
+	e.g.
+		1 => 2
+		3 => 4
+
+`
+}
+
+func (c *commandFsMetaChangeVolumeId) Do(args []string, commandEnv *CommandEnv, writer io.Writer) (err error) {
+
+	fsMetaChangeVolumeIdCommand := flag.NewFlagSet(c.Name(), flag.ContinueOnError)
+	dir := fsMetaChangeVolumeIdCommand.String("dir", "/", "fix all metadata under this folder")
+	mappingFileName := fsMetaChangeVolumeIdCommand.String("mapping", "", "a file with multiple volume id changes, with each line as x=>y")
+	fromVolumeId := fsMetaChangeVolumeIdCommand.Uint("fromVolumeId", 0, "change metadata with this volume id")
+	toVolumeId := fsMetaChangeVolumeIdCommand.Uint("toVolumeId", 0, "change metadata to this volume id")
+	isForce := fsMetaChangeVolumeIdCommand.Bool("force", false, "applying the metadata changes")
+	if err = fsMetaChangeVolumeIdCommand.Parse(args); err != nil {
+		return err
+	}
+
+	// load the mapping
+	mapping := make(map[needle.VolumeId]needle.VolumeId)
+	if *mappingFileName != "" {
+		readMappingFromFile(*mappingFileName, mapping)
+	} else {
+		if *fromVolumeId == *toVolumeId {
+			return fmt.Errorf("no volume id changes")
+		}
+		if *fromVolumeId == 0 || *toVolumeId == 0 {
+			return fmt.Errorf("volume id can not be zero")
+		}
+		mapping[needle.VolumeId(*fromVolumeId)] = needle.VolumeId(*toVolumeId)
+	}
+
+	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) {
+			if !entry.IsDirectory {
+				var hasChanges bool
+				for _, chunk := range entry.Chunks {
+					chunkVolumeId := chunk.Fid.VolumeId
+					if toVolumeId, found := mapping[needle.VolumeId(chunkVolumeId)]; found {
+						hasChanges = true
+						chunk.Fid.VolumeId = uint32(toVolumeId)
+						chunk.FileId = ""
+					}
+				}
+				if hasChanges {
+					println("Updating", parentPath, entry.Name)
+					if *isForce {
+						if updateErr := filer_pb.UpdateEntry(client, &filer_pb.UpdateEntryRequest{
+							Directory: string(parentPath),
+							Entry:     entry,
+						}); updateErr != nil {
+							fmt.Printf("failed to update %s/%s: %v\n", parentPath, entry.Name, updateErr)
+						}
+					}
+				}
+			}
+		})
+	})
+}
+
+func readMappingFromFile(filename string, mapping map[needle.VolumeId]needle.VolumeId) error {
+	mappingFile, openErr := os.Open(filename)
+	if openErr != nil {
+		return fmt.Errorf("failed to open file %s: %v", filename, openErr)
+	}
+	defer mappingFile.Close()
+	mappingContent, readErr := io.ReadAll(mappingFile)
+	if readErr != nil {
+		return fmt.Errorf("failed to read file %s: %v", filename, readErr)
+	}
+	for _, line := range strings.Split(string(mappingContent), "\n") {
+		parts := strings.Split(line, "=>")
+		if len(parts) != 2 {
+			println("unrecognized line:", line)
+			continue
+		}
+		x, errX := strconv.ParseUint(strings.TrimSpace(parts[0]), 10, 64)
+		if errX != nil {
+			return errX
+		}
+		y, errY := strconv.ParseUint(strings.TrimSpace(parts[1]), 10, 64)
+		if errY != nil {
+			return errY
+		}
+		mapping[needle.VolumeId(x)] = needle.VolumeId(y)
+	}
+	return nil
+}