1.\"- 2.\" Copyright (c) 2000 Robert N. M. Watson 3.\" All rights reserved. 4.\" 5.\" Redistribution and use in source and binary forms, with or without 6.\" modification, are permitted provided that the following conditions 7.\" are met: 8.\" 1. Redistributions of source code must retain the above copyright 9.\" notice, this list of conditions and the following disclaimer. 10.\" 2. Redistributions in binary form must reproduce the above copyright 11.\" notice, this list of conditions and the following disclaimer in the 12.\" documentation and/or other materials provided with the distribution. 13.\" 14.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24.\" SUCH DAMAGE. 25.\" 26.\" $FreeBSD$ 27.\" 28.Dd March 30, 2000 29.Dt EXTATTRCTL 8 30.Os 31.Sh NAME 32.Nm extattrctl 33.Nd manage FFS extended attributes 34.Sh SYNOPSIS 35.Nm 36.Cm start 37.Ar path 38.Nm 39.Cm stop 40.Ar path 41.Nm 42.Cm initattr 43.Op Fl f 44.Op Fl p Ar path 45.Ar attrsize 46.Ar attrfile 47.Nm 48.Cm enable 49.Ar path 50.Ar attrname 51.Ar attrfile 52.Nm 53.Cm disable 54.Ar path 55.Ar attrname 56.Sh DESCRIPTION 57.Nm 58is the management utility for extended attributes over the FFS file system. 59.Nm 60allows the starting and stopping of extended attributes on a file system, 61as well as initialization of attribute backing files, and enabling and 62disabling of specific extended attributes on a file system. 63.Pp 64The first argument on the command line indicates the operation to be 65performed. 66Operation must be one of the following: 67.Bl -tag -width indent 68.It Cm start Ar path 69Start extended attribute support on the file system named using 70.Ar path . 71The file system must be an FFS file system, and the FFS_EXTATTR kernel 72option must have been enabled. 73.It Cm stop Ar path 74Stop extended attribute support on the file system named using 75.Ar path . 76Extended attribute support must previously have been started. 77.It Xo 78.Cm initattr 79.Op Fl f 80.Op Fl p Ar path 81.Ar attrsize attrfile 82.Xc 83Create and initialize a file to use as an attribute backing file. 84You must specify a maximum per-inode size for the attribute in bytes in 85.Ar attrsize , 86as well as the file where the attribute will be stored, using 87.Ar attrfile . 88.Pp 89The 90.Fl f 91argument may be used to indicate that it is alright to overwrite an 92existing attribute backing file; otherwise, if the target file exists, 93an error will be returned. 94.Pp 95The 96.Fl p Ar path 97argument may be used to preallocate space for all attributes rather than 98relying on sparse files to conserve space. 99This has the advantage of guaranteeing that space will be available 100for attributes when they are written, preventing low disk space conditions 101from denying attribute service. 102.Pp 103This file should not exist before running 104.Cm initattr. 105.It Cm enable Ar path Ar attrname Ar attrfile 106Enable an attribute named 107.Ar attrname 108on the file system identified using 109.Ar path , 110and backed by initialized attribute file 111.Ar attrfile . 112The backing file must have been initialized using 113.Cm initattr 114before its first use. 115Attributes must have been started on the file system prior to the 116enabling of any attributes. 117.It Cm disable Ar path Ar attrname 118Disable the attributed named 119.Ar attrname 120on the file system identified by 121.Ar path . 122The file system must have attributes started on it, and the attribute 123most have been enabled using 124.Cm enable . 125.Sh EXAMPLES 126.Pp 127.Dl extattrctl start / 128.Pp 129Start extended attributes on the root file system. 130.Pp 131.Dl extattrctl initattr 17 /.attribute/md5 132.Pp 133Create an attribute backing file in /.attribute/md5, and set the maximum 134size of each attribute to 17 bytes, with a sparse file used for storing 135the attributes. 136.Pp 137.Dl extattrctl enable / md5 /.attribute/md5 138.Pp 139Enable an attribute named md5 on the root file system, backed from the file 140/.attribute/md5. 141.Pp 142.Dl extattrctl disable / md5 143.Pp 144Disable the attribute named md5 on the root file system. 145.Pp 146.Dl extattrctl stop / 147.Pp 148Stop extended attributes on the root file system. 149.Sh SEE ALSO 150.Xr getextattr 8 , 151.Xr setextattr 8 , 152.Xr extattr 9 153.Sh HISTORY 154Extended attribute support was developed as part of the TrustedBSD Project, 155and introduced in 156.Fx 5.0 . 157It was developed to support security extensions requiring additional labels 158to be associated with each file or directory. 159.Sh AUTHORS 160Robert N M Watson 161