juicefs sync error：juicefs sync --dirs -f --threads 10 /mnt/kkk/1.txt nfs://10.200.88.213:/mnt/hhh/1.txt --debug

[xiaoyanjia-94]

When the 1.txt file already exists in the DST NFS directory，juicefs sync error happened。

• JuiceFS version： 1.2.0-rc1+2024-06-03.f5bf1d03e88
  ----cmd/sync.go ---- The bug may occur here
  375 store, err := object.CreateStorage(name, endpoint, accessKey, secretKey, token)
  376 if name == "nfs" && err != nil {
  377 p := u.Path
  378 for err != nil && strings.Contains(err.Error(), "MNT3ERR_NOENT") {
  379 p = filepath.Dir(p)
  380 store, err = object.CreateStorage(name, u.Host+p, accessKey, secretKey, token)
  381 }
  382 if err == nil {
  383 store = object.WithPrefix(store, u.Path[len(p):])
  384 }
  385 }

---

When the 1.txt file already exists in the destination NFS directory, line 375 does not return an MNT3ERR_NOTDIR error as expected. Instead, it returns nil and the go-nfs-client proceeds to mount the NFS storage client normally, even in an abnormal situation. Subsequently, an error arises during the data copying process.

[SandyXSD]

It's more like a bug (or maybe by design, IDK) of NFS server, because it returns OK for mount request with a regular file as the dirpath here.

[xiaoyanjia-94]

error log:
2024/06/07 18:01:31.704360 juicefs[94967] : maxprocs: Leaving GOMAXPROCS=32: CPU quota undefined [maxprocs.go:47]
2024/06/07 18:01:31.704652 juicefs[94967] : Debug agent listening on 127.0.0.1:6060 [main.go:321]
2024/06/07 18:01:31.704737 juicefs[94967] : Creating file storage at endpoint /mnt/kkk/1.txt [object_storage.go:167]
2024/06/07 18:01:31.704952 juicefs[94967] : Creating nfs storage at endpoint 10.200.88.213:/mnt/hhh/1.txt [object_storage.go:167]
2024/06/07 18:01:31.731339 juicefs[94967] : Prometheus metrics listening on 127.0.0.1:39805 [mount.go:135]
2024/06/07 18:01:31.731967 juicefs[94967] : Syncing from file:///mnt/kkk/1.txt to nfs://[email protected]:/mnt/hhh/1.txt [sync.go:1342]
2024/06/07 18:01:31.732039 juicefs[94967] : maxResults: 1000, defaultPartSize: 5242880, maxBlock: 10485760 [sync.go:767]
2024/06/07 18:01:31.732082 juicefs[94967] : Iterating objects from file:///mnt/kkk/1.txt with prefix start "" [sync.go:81]
2024/06/07 18:01:31.732155 juicefs[94967] : Listing objects from file:///mnt/kkk/1.txt marker "" [sync.go:110]
2024/06/07 18:01:31.746930 juicefs[94967] : Try 1 failed: NFS3ERR_NOTDIR [sync.go:190]
2024/06/07 18:01:31.748298 juicefs[94967] : Try 2 failed: NFS3ERR_NOTDIR [sync.go:190]
2024/06/07 18:01:32.763607 juicefs[94967] : Try 3 failed: NFS3ERR_NOTDIR [sync.go:190]

[SandyXSD]

We will leave this issue as it is for now, because it is not simple and is only encountered in a very specific scenario.