nfs (or ceph, or k8s) works strange: ls/tree not working, but i can read files

I have some problems and i want to know where i have to check.

• my env: ceph nfs mount to a k8s pod

• problem:

  • at mounted path (on k8s node and inside the pod too), ls/tree not working, but i can read/write files

  • because i can read files and only can't see in filesystem, so i thought inode is weird.

  • mounted volume has negative IUsed and increasing Inodes when i create/modify files, which i don't know why.

  • here is the command/result and my mount option(on the machine)

    sh-4.2# ls -al
    total 0
    drwx--x--x   1  root root 7 6 02:45 .
    drwxrwxrwx 216  root root 7 6 02:45 ..
    sh-4.2# 
    sh-4.2# cd 03
    sh-4.2# 
    sh-4.2# ls -al
    total 0
    drwxr-xr-x   1  root root 7 6 02:45 .
    drwx--x--x 216  root root 7 6 02:45 ..
    sh-4.2# 
    sh-4.2# cat test
    cat: test: No such file or directory
    sh-4.2# 
    sh-4.2# echo "FILE EXISTS" > test
    sh-4.2# 
    sh-4.2# ls -al
    total 0
    drwxr-xr-x   1  root root 7 6 02:45 .
    drwx--x--x 216  root root 7 6 02:45 ..
    sh-4.2# 
    sh-4.2# cat test
    FILE EXISTS
    sh-4.2# 
    sh-4.2# df -iH --type=nfs4
    Filysystem                  Inodes  IUsed  IFree  IUse%  Mounted on 
    some.ceph.url.com/path1        657  -1.7G   1.7G      -  /data0/kubelet/pods/**/volumes/kubernetes.io~nfs/path1
    sh-4.2#
    sh-4.2# cat /etc/mtab | grep nfs4
    some.ceph.url.com/path1 /data0/kubelet/pods/**/volumes/kubernetes.io~nfs/**** 
    nfs4 rw,relatime,vers=4.1,rsize=1048576,wsize=1048576,namlen=255,hard,proto=tcp,
    timeo=600,retrans=2,sec=sys,clientaddr=172.30.*.*,local_lock=none,addr=172.30.*.* 0 0
    

Thank you in advance. where can i find the root cause or searching keyword?