add a tool to recover files from trash

cmd/main.go

@@ -72,6 +72,7 @@ func Main(args []string) error {
 			cmdMdtest(),
 			cmdWarmup(),
 			cmdRmr(),
+			cmdRecover(),
 			cmdSync(),
 		},
 	}

cmd/recover.go

@@ -0,0 +1,112 @@
+package cmd
+
+import (
+	"bytes"
+	"math/rand"
+	"strconv"
+	"sync"
+	"syscall"
+
+	"github.com/juicedata/juicefs/pkg/meta"
+	"github.com/juicedata/juicefs/pkg/utils"
+	"github.com/urfave/cli/v2"
+)
+
+func cmdRecover() *cli.Command {
+	return &cli.Command{
+		Name:      "recover",
+		Action:    recover,
+		Category:  "ADMIN",
+		Usage:     "recover files from trash",
+		ArgsUsage: "META HOUR ...",
+		Description: `
+Rebuild the tree structure for trash files, and move them back to original directories.
+
+Examples:
+$ juicefs recover redis://localhost/1 2023-10-10-01`,
+		Flags: []cli.Flag{
+			&cli.BoolFlag{
+				Name:  "move-to-original",
+				Usage: "move the recovered files into original directory",
+			},
+			&cli.IntFlag{
+				Name:  "threads",
+				Value: 10,
+				Usage: "number of threads",
+			},
+		},
+	}
+}
+
+func recover(ctx *cli.Context) error {
+	setup(ctx, 1)
+	removePassword(ctx.Args().Get(0))
+	m := meta.NewClient(ctx.Args().Get(0), &meta.Config{Retries: 10, Strict: true})
+	for i := 0; i+1 < ctx.NArg(); i++ {
+		path := ctx.Args().Get(i + 1)
+		doRecover(m, path, ctx.Bool("move-to-original"), ctx.Int("threads"))
+	}
+	return nil
+}
+
+func doRecover(m meta.Meta, path string, move bool, threads int) syscall.Errno {
+	logger.Infof("recover files in %s", path)
+	ctx := meta.Background
+	var parent meta.Ino
+	var attr meta.Attr
+	err := m.Lookup(ctx, meta.TrashInode, path, &parent, &attr)
+	if err != 0 {
+		return err
+	}
+	var entries []*meta.Entry
+	err = m.Readdir(meta.Background, parent, 0, &entries)
+	if err != 0 {
+		return err
+	}
+	entries = entries[2:]
+	// to avoid conflict
+	rand.Shuffle(len(entries), func(i, j int) {
+		entries[i], entries[j] = entries[j], entries[i]
+	})
+
+	var parents = make(map[meta.Ino]bool)
+	if !move {
+		for _, e := range entries {
+			if e.Attr.Typ == meta.TypeDirectory {
+				parents[e.Inode] = true
+			}
+		}
+	}
+
+	todo := make(chan *meta.Entry, 1000)
+	p := utils.NewProgress(false, true)
+	recovered := p.AddCountBar("recovered", int64(len(entries)))
+	skipped := p.AddCountBar("skipped", int64(len(entries)))
+	var wg sync.WaitGroup
+	for i := 0; i < threads; i++ {
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			for e := range todo {
+				ps := bytes.SplitN(e.Name, []byte("-"), 3)
+				dst, _ := strconv.Atoi(string(ps[0]))
+				if move || parents[meta.Ino(dst)] {
+					m.Rename(ctx, parent, string(e.Name), meta.Ino(dst), string(ps[2]), 0, nil, nil)
+					recovered.Increment()
+				} else {
+					skipped.Increment()
+				}
+			}
+		}()
+	}
+
+	for _, e := range entries {
+		todo <- e
+	}
+	close(todo)
+	wg.Wait()
+	recovered.Done()
+	p.Done()
+	logger.Infof("recovered %d files in %s", recovered.Current(), path)
+	return 0
+}