ref: 0ec1cfd78b495e9be40e4aa24e35b2aa5d5e5704
dir: /man/4/lockfs/
.TH LOCKFS 4 .SH NAME lockfs \- exclusive access file server .SH SYNOPSIS .B lockfs [ .B -A ] [ .B -a .I alg ]... [ .B -p .I addr ] .I dir [ .I mountpoint ] .SH DESCRIPTION .I 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 .I lockfs obtains a lock on the file, or blocks until a lock can be obtained. .I Lockfs serves a single-level directory that initially contains the files in .IR dir . If the .B -p option is provided, .I lockfs will listen for incoming connections on .IR addr , authenticating them as required. Each .B -a argument provides an acceptable algorithm to run on the connection. The list of all .IR alg s is passed to .B server (see .IR security-auth (2)). If no .B -a arguments are given, .B "-a none" is assumed. If the .B -A option is given, then no authentication will be performed. .PP If the .B -p option is not given, the lockfs file system will be mounted on .IR mountpoint , or .I dir if .I mountpoint is not given. .SH EXAMPLE Run a lock server guarding access to .BR /lib/datafiles : .IP .EX lockfs -p 'tcp!*!32454' /lib/datafiles .EE .PP Mount the above server (where .I locksrv was originally run on a server named .IR machine . .IP .EX mount -c tcp!\fImachine\fP!32454 /n/remote .EE .SH SOURCE .B /appl/cmd/lockfs.b .SH BUGS There's no way to break a lock held by a malingering process. .PP Should probably support multi-level directories.