LOCKFS(4) LOCKFS(4)
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 names-
pace, 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 con-
tains 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 pro-
cess.
Should probably support multi-level directories.
Page 1 Plan 9 (printed 12/22/24)