.\"
.TH LOCKDEV 8 "SEPTEMBER 2009" "" ""
.\"
.\" Man page written by Jiri Popelka <jpopelka AT redhat DOT com>
.\"
.SH NAME
\fBLockdev\fR is a setgid binary,
which provides a reliable way to put an exclusive lock
in /var/lock to devices (e.g. ttyS0) using both FSSTND and SVr4 methods,
so regular users don't need write access there.

This task is achieved through calls to the liblockdev(3) API.

.SH SYNOPSIS
.B /usr/sbin/lockdev
.RB [< operation >]
.RB < device >

.SH DESCRIPTION
The \fBlockdev\fR command can perform one of the following operations (calls to liblockdev(3) API):

\fB-l\fR - lock device with \fBdev_lock()\fR function

\fB-u\fR - unlock device with \fBdev_unlock()\fR function

\fBno operation\fR - test lock with \fBdev_testlock()\fR function

.SH RETURN VALUES
   Value  dev_lock         dev_unlock       dev_testlock
   0      OK               OK               not locked
   1      locked other     locked other     locked
   2      EACCES
   3      EROFS
   4      EFAULT
   5      EINVAL
   6      ENAMETOOLONG
   7      ENOENT
   8      ENOTDIR
   9      ENOMEM
  10      ELOOP
  11      EIO
 255      error               error               error

.SH SEE ALSO
.BR lockdev (3).