NAME

lockfs − exclusive access file server

SYNOPSIS

lockfs [ -A ] [ -a alg ]... [ -p addr ] dir [ mountpoint ]

DESCRIPTION

Lockfs acts as a filesystem layer above an existing namespace, allowing multiple-reader, exclusive writer access to the files therein. Opening a file served by lockfs obtains a lock on the file, or blocks until a lock can be obtained.  Lockfs serves a single-level directory that initially contains the files in dir. If the -p option is provided, lockfs will listen for incoming connections on addr, authenticating them as required. Each -a argument provides an acceptable algorithm to run on the connection.  The list of all algs is passed to server (see security-auth(2)). If no -a arguments are given, -a none is assumed.  If the -A option is given, then no authentication will be performed. 

If the -p option is not given, the lockfs file system will be mounted on mountpoint, or dir if mountpoint is not given. 

EXAMPLE

Run a lock server guarding access to /lib/datafiles:

locksrv -p ’tcp!*!32454’ /lib/datafiles

Mount the above server (where locksrv was originally run on a server named machine.

mount -c tcp!machine!32454 /n/remote

SOURCE

/appl/lockfs

BUGS

There’s no way to break a lock held by a malingering process. 

Should probably support multi-level directories.