path: root/usr/src/man/man1m/lockfs.1m

'\" te
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.TH LOCKFS 1M "Jan 2, 2008"
.SH NAME
lockfs \- change or report file system locks
.SH SYNOPSIS
.LP
.nf
\fB/usr/sbin/lockfs\fR [\fB-adefhnuw\fR] [\fB-c\fR \fIstring\fR] [\fIfile-system\fR]...
.fi

.SH DESCRIPTION
.sp
.LP
\fBlockfs\fR is used to change and report the status of file system locks.
\fBlockfs\fR reports the lock status and unlocks the file systems that were
improperly left locked.
.sp
.LP
Using \fBlockfs\fR to lock a file system is discouraged because this requires
extensive knowledge of SunOS internals to be used effectively and correctly.
.sp
.LP
When invoked with no arguments, \fBlockfs\fR lists the \fBUFS\fR file systems
that are locked. If \fIfile-system\fR is not specified, and \fB-a\fR is
specified, \fBlockfs\fR is run on all mounted, \fBUFS\fR type file systems.
.SH OPTIONS
.sp
.LP
The options are mutually exclusive: \fBwndheuf\fR. If you do specify more than
one of these options on a \fBlockfs\fR command line, the utility does not
protest and invokes only the last option specified. In particular, you cannot
specify a flush (\fB-f\fR) and a lock (for example, \fB-w\fR) on the same
command line. However, all locking operations implicitly perform a flush, so
the \fB-f\fR is superfluous when specifying a lock.
.sp
.LP
You must be super-user to use any of the following options, with the exception
of \fB-a\fR, \fB-f\fR and \fB-v\fR.
.sp
.LP
The following options are supported.
.sp
.ne 2
.na
\fB\fB-a\fR\fR
.ad
.sp .6
.RS 4n
Apply command to all mounted, \fBUFS\fR type file systems. \fIfile-system\fR is
ignored when \fB-a\fR is specified.
.RE

.sp
.ne 2
.na
\fB\fB-c\fR \fIstring\fR\fR
.ad
.sp .6
.RS 4n
Accept a string that is passed as the comment field. The \fB-c\fR only takes
affect when the lock is being set using the \fB-d\fR, \fB-h\fR, \fB-n\fR,
\fB-u\fR, or \fB-w\fR options.
.RE

.sp
.ne 2
.na
\fB\fB-d\fR\fR
.ad
.sp .6
.RS 4n
Delete-lock (\fBdlock\fR) the specified \fIfile-system\fR. dlock suspends
access that could remove directory entries.
.RE

.sp
.ne 2
.na
\fB\fB-e\fR\fR
.ad
.sp .6
.RS 4n
Error-lock (\fBelock\fR) the specified \fIfile-system\fR. elock blocks all
local access to the locked file system and returns \fBEWOULDBLOCK\fR on all
remote access. File systems are elocked by \fBUFS\fR on detection of internal
inconsistency. They may only be unlocked after successful repair by \fBfsck\fR,
which is usually done automatically (see \fBmount_ufs\fR(1M)). elocked file
systems can be unmounted.
.RE

.sp
.ne 2
.na
\fB\fB-f\fR\fR
.ad
.sp .6
.RS 4n
Force a synchronous flush of all data that is dirty at the time \fBfsflush\fR
is run to its backing store for the named file system (or for all file
systems.)
.sp
It is a more reliable method than using \fBsync\fR(1M) because it does not
return until all possible data has been pushed. In the case of \fBUFS\fR
filesystems with logging enabled, the log is also rolled before returning.
Additional data can be modified by the time \fBfsflush\fR exits, so using one
of the locking options is more likely to be of general use.
.RE

.sp
.ne 2
.na
\fB\fB-h\fR\fR
.ad
.sp .6
.RS 4n
Hard-lock (\fBhlock\fR) the specified \fIfile-system\fR. hlock returns an error
on every access to the locked file system, and cannot be unlocked. hlocked file
systems can be unmounted.
.RE

.sp
.ne 2
.na
\fB\fB-n\fR\fR
.ad
.sp .6
.RS 4n
Name-lock (\fBnlock\fR) the specified \fIfile-system\fR. nlock suspends
accesses that could change or remove existing directories entries.
.RE

.sp
.ne 2
.na
\fB\fB-u\fR\fR
.ad
.sp .6
.RS 4n
Unlock (\fBulock\fR) the specified \fIfile-system\fR. ulock awakens suspended
accesses.
.RE

.sp
.ne 2
.na
\fB\fB-v\fR\fR
.ad
.sp .6
.RS 4n
Enable verbose output.
.RE

.sp
.ne 2
.na
\fB\fB-w\fR\fR
.ad
.sp .6
.RS 4n
Write-lock (\fBwlock\fR) the specified \fIfile-system\fR. wlock suspends writes
that would modify the file system. Access times are not kept while a file
system is write-locked.
.RE

.SH OPERANDS
.sp
.LP
The following operands are supported.
.sp
.ne 2
.na
\fB\fIfile-system\fR\fR
.ad
.sp .6
.RS 4n
A list of path names separated by whitespace. Note that \fIfile-system\fR can
be a directory rather than the specific name of a file system, such as \fB/\fR
or \fB/usr\fR. For example, if you specify \fB/export/home\fR as an argument to
a \fBlockfs\fR command and \fB/export/home\fR is mounted on the root (\fB/\fR)
file system, the \fBlockfs\fR command will take effect on the root file system.
.RE

.SH USAGE
.sp
.LP
See \fBlargefile\fR(5) for the description of the behavior of \fBlockfs\fR when
encountering files greater than or equal to 2 Gbyte ( 2^31 bytes).
.SH EXAMPLES
.LP
\fBExample 1 \fRUsing \fBlockfs\fR \fB-a\fR
.sp
.LP
In the following examples, \fIfilesystem\fR is the pathname of the mounted-on
directory (mount point). \fBLocktype\fR is one of "\fBwrite\fR," "\fIname\fR,"
"\fIdelete\fR," "\fIhard\fR," or "\fIunlock\fR". When enclosed in parenthesis,
the lock is being set. \fBComment\fR is a string set by the process that last
issued a lock command.

.sp
.LP
The following example shows the \fBlockfs\fR output when only the \fB-a\fR
option is specified.

.sp
.in +2
.nf
example#  \fB/usr/sbin/lockfs -a\fR
.fi
.in -2
.sp

.sp

.sp
.TS
l l l
l l l .
Filesystem	Locktype	 Comment
/	unlock	
/var	unlock	
.TE

.sp
.in +2
.nf
example#
.fi
.in -2
.sp

.LP
\fBExample 2 \fRUsing \fBlockfs\fR \fB-w\fR
.sp
.LP
The following example shows the \fBlockfs\fR output when the \fB-w\fR option is
used to write lock the \fB/var\fR file system and the comment string is set
using the \fB-c\fR option.  The \fB-a\fR option is then specified on a separate
command line.

.sp
.in +2
.nf
example#  \fB/usr/sbin/lockfs -w -c "lockfs: write lock example" /var\fR
example#  \fB/usr/sbin/lockfs -a\fR
.fi
.in -2
.sp

.sp

.sp
.TS
l l l
l l l .
Filesystem	Locktype	Comment
/	unlock	
/var	write	lockfs: write lock example
.TE

.sp
.in +2
.nf
example#
.fi
.in -2
.sp

.LP
\fBExample 3 \fRUsing \fBlockfs\fR \fB-u\fR
.sp
.LP
The following example shows the \fBlockfs\fR output when the \fB-u\fR option is
used to unlock the \fB/var\fR file system and the comment string is set using
the \fB-c\fR option.

.sp
.in +2
.nf
example#  \fB/usr/sbin/lockfs -uc "lockfs: unlock example" /var\fR
example#  \fB/usr/sbin/lockfs /var\fR
.fi
.in -2
.sp

.sp

.sp
.TS
l l l
l l l .
Filesystem	Locktype	Comment
/var	unlock	lockfs: unlock example
.TE

.sp
.in +2
.nf
example#
.fi
.in -2
.sp

.SH SEE ALSO
.sp
.LP
\fBkill\fR(1), \fBmount_ufs\fR(1M), \fBsync\fR(1M), \fBattributes\fR(5),
\fBlargefile\fR(5), \fBufs\fR(7FS),
.sp
.LP
\fI\fR
.SH DIAGNOSTICS
.sp
.ne 2
.na
\fB\fIfile system\fR\fB: Not owner\fR\fR
.ad
.sp .6
.RS 4n
You must be root to use this command.
.RE

.sp
.ne 2
.na
\fB\fIfile system\fR \fB:Deadlock condition detected/avoided\fR\fR
.ad
.sp .6
.RS 4n
A file is enabled for accounting or swapping, on \fIfile system\fR.
.RE

.sp
.ne 2
.na
\fB\fIfile system\fR\fB: Device busy\fR\fR
.ad
.sp .6
.RS 4n
Another process is setting the lock on \fIfile system\fR.
.RE