Missing pipe /var/lib/nfs/rpc_pipefs/nfsd/cld on OpenWrt

Missing pipe /var/lib/nfs/rpc_pipefs/nfsd/cld on OpenWrt

[John]

I want to modify the nfs-kernel-server package to use nfsdcld for client tracking, but am hitting a snag: I can't figure out why the pipe /var/lib/nfs/rpc_pipefs/nfsd/cld is missing or what creates it.

Here is my current version: https://github.com/graysky2/packages/commit/c68d0ca16b3b69a0ffcad3dbb20bad58ee49a638

I have the lines in the init script to start /usr/sbin/nfsdcld commented out so it can be run manually with the debug option on the shell to see why it fails. What creates the pipe /var/lib/nfs/rpc_pipefs/nfsd/cld and why is it not doing so is the questions I cannot answer. Any insights are appreciated.

# nfsdcld -F -d
nfsdcld: sqlite_startup_query_grace: current_epoch=1 recovery_epoch=0
nfsdcld: sqlite_check_db_health: returning 0
nfsdcld: sqlite_copy_cltrack_records: returning -1
nfsdcld: sqlite_prepare_dbh: num_cltrack_records = 0

nfsdcld: sqlite_prepare_dbh: num_legacy_records = 0

nfsdcld: cld_pipe_init: init pipe handlers
nfsdcld: cld_pipe_open: opening upcall pipe /var/lib/nfs/rpc_pipefs/nfsd/cld
nfsdcld: cld_pipe_open: open of /var/lib/nfs/rpc_pipefs/nfsd/cld failed: No such file or directory
nfsdcld: main: Starting event dispatch handler.

Re: Missing pipe /var/lib/nfs/rpc_pipefs/nfsd/cld on OpenWrt

[Scott Mayhew]

On Sat, 02 Aug 2025, John wrote:

> I want to modify the nfs-kernel-server package to use nfsdcld for client tracking, but am hitting a snag: I can't figure out why the pipe /var/lib/nfs/rpc_pipefs/nfsd/cld is missing or what creates it.
> 
> Here is my current version: https://github.com/graysky2/packages/commit/c68d0ca16b3b69a0ffcad3dbb20bad58ee49a638
> 
> I have the lines in the init script to start /usr/sbin/nfsdcld commented out so it can be run manually with the debug option on the shell to see why it fails. What creates the pipe /var/lib/nfs/rpc_pipefs/nfsd/cld and why is it not doing so is the questions I cannot answer. Any insights are appreciated.
> 
> # nfsdcld -F -d
> nfsdcld: sqlite_startup_query_grace: current_epoch=1 recovery_epoch=0
> nfsdcld: sqlite_check_db_health: returning 0
> nfsdcld: sqlite_copy_cltrack_records: returning -1
> nfsdcld: sqlite_prepare_dbh: num_cltrack_records = 0
> 
> nfsdcld: sqlite_prepare_dbh: num_legacy_records = 0
> 
> nfsdcld: cld_pipe_init: init pipe handlers
> nfsdcld: cld_pipe_open: opening upcall pipe /var/lib/nfs/rpc_pipefs/nfsd/cld
> nfsdcld: cld_pipe_open: open of /var/lib/nfs/rpc_pipefs/nfsd/cld failed: No such file or directory
> nfsdcld: main: Starting event dispatch handler.
> 

It gets created when nfsd starts up (see nfsd4_cld_register_sb() in
fs/nfsd/nfs4recover.c).  At that point you should see nfsdcld get an
inotify event, open the cld file, and continue doing its thing.

-Scott