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:

lockfs -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/cmd/lockfs.b

BUGS

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

Should probably support multi-level directories.

LOCKFS(4)

Rev:  Mon Aug 05 16:49:19 GMT 2002