Filestore directory becomes inaccessible/undeletable when containing long link - "Remote I/O error "

[bgulko]

Summary:

I recently created a Compute Engine instance (with boot image, ubuntu 24.04), and successfully created and mounted a FileStore share (NFS4) via NFS/mount.

When restoring my data from a 500GB+ .tar file, I found that some (just a few) directories could not be listed nor deleted.

Details:

for problematic directory "foo" in restored ./bar/foo/ I can

$ cd bar 

and

ls -1 .

, which produces "foo". In addition

cd ./bar/foo

works but, then

ls 

results in  

reading directory '.': Remote I/O error

while trying to remove foo by

 cd ./bar; sudo rm -rf foo

( or a variety of similar actions) results in

rm: cannot remove 'foo': Remote I/O error

I CAN mv/rename "foo" to something else (e.g. "baz") but then I can not delete the "something else".

A bit of exploration in creating directories, files, and links shows that after moving foo to a new name, I can recreate a new subdirectory called foo, and then create regular files and links in the recreated foo. However, when I create a symbolic link in foo AND the that link's target file name length exceeds 127  (!) , the problem manifests, then any preexisting contents of foo become unreadable and foo itself becomes undeletable (as above) .

This is not intermittent, I have over a dozen examples of this behavior.

Request (Help!):

1. How can I manage links with targets longer than 127 characters on FileStore with NFS4.1 ? (so I can usefully restore my tar files. The archive command (tar -xvf ) seems to complete without error and the archive contains a few links with long targets, generally long absolute paths)
2. How can I delete these old directories and release their content (short of a backup and restore to a new fileshare). Given that any attempt to remove them (or rename / remove) results in "rm: cannot remove 'foo': Remote I/O error" [considered alternative seems backup and restore to a new FS share, backup may simply not save the problematic links].

Note this problem does not arise on AWS EC2/EFS/NFS4, nor on my local directories local Ubuntu 20.04 VM.  

Many thanks in advance,