freebsd-dev/share/man/man5/tmpfs.5

.\"-
.\" Copyright (c) 2007 Xin LI
.\" All rights reserved.
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.\" Copyright (c) 2005, 2006 The NetBSD Foundation, Inc.
.\" All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
.\" PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
.\" POSSIBILITY OF SUCH DAMAGE.
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.\" $FreeBSD$
.\"
.Dd April 23, 2012
.Dt TMPFS 5
.Os
.Sh NAME
.Nm tmpfs
.Nd "efficient memory file system"
.Sh SYNOPSIS
To compile this driver into the kernel,
place the following line in your
kernel configuration file:
.Bd -ragged -offset indent
.Cd "options TMPFS"
.Ed
.Pp
Alternatively, to load the driver as a
module at boot time, place the following line in
.Xr loader.conf 5 :
.Bd -literal -offset indent
tmpfs_load="YES"
.Ed
.Sh DESCRIPTION
The
.Nm
driver will permit the
.Fx
kernel to access
.Tn tmpfs
file systems.
.Sh OPTIONS
The following options are available when
mounting
.Nm
file systems:
.Bl -tag -width indent
.It Cm gid
Specifies the group ID of the root inode of the file system.
Defaults to the mount point's GID.
.It Cm uid
Specifies the user ID of the root inode of the file system.
Defaults to the mount point's UID.
.It Cm mode
Specifies the mode (in octal notation) of the root inode of the file system.
Defaults to the mount point's mode.
.It Cm inodes
Specifies the maximum number of nodes available to the file system.
If not specified, the file system chooses a reasonable maximum based on
the file system size, which can be limited with the
.Cm size
option.
.It Cm size
Specifies the total file system size in bytes.
If zero (the default) or a value larger than SIZE_MAX - PAGE_SIZE
is given, the available amount of memory (including
main memory and swap space) will be used.
.It Cm maxfilesize
Specifies the maximum file size in bytes.
Defaults to the maximum possible value.
.El
.Sh EXAMPLES
To mount a
.Nm
memory file system:
.Pp
.Dl "mount -t tmpfs tmpfs /tmp"
.Sh SEE ALSO
.Xr nmount 2 ,
.Xr unmount 2 ,
.Xr fstab 5 ,
.Xr mdmfs 8 ,
.Xr mount 8
.Sh HISTORY
The
.Nm
driver first appeared in
.Fx 7.0 .
.Sh AUTHORS
.An -nosplit
The
.Nm
kernel implementation was written by
.An Julio M. Merino Vidal Aq jmmv@NetBSD.org
as a Google SoC project.
.Pp
.An Rohit Jalan
and others ported it from
.Nx
to
.Fx .
.Pp
This manual page was written by
.An Xin LI Aq delphij@FreeBSD.org .
.Sh BUGS
Some file system mount time options may not be well-supported.
Improve descriptions for tmpfs mount options. The descriptions have been mostly obtained from NetBSD mount_tmpfs(8) manual page. Obtained from: NetBSD Discussed with: delphij 2010-02-16 19:59:10 +00:00			`.\"-`
Add a manual page for tmpfs(5). 2007-06-16 02:35:29 +00:00			`.\" Copyright (c) 2007 Xin LI`
			`.\" All rights reserved.`
			`.\"`
			`.\" Redistribution and use in source and binary forms, with or without`
			`.\" modification, are permitted provided that the following conditions`
			`.\" are met:`
			`.\" 1. Redistributions of source code must retain the above copyright`
			`.\" notice, this list of conditions and the following disclaimer.`
			`.\" 2. Redistributions in binary form must reproduce the above copyright`
			`.\" notice, this list of conditions and the following disclaimer in the`
			`.\" documentation and/or other materials provided with the distribution.`
			`.\"`
			.\" THIS DOCUMENTATION IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
			`.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES`
			`.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.`
			`.\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,`
			`.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT`
			`.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,`
			`.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY`
			`.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT`
			`.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF`
			`.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.`
			`.\"`
Improve descriptions for tmpfs mount options. The descriptions have been mostly obtained from NetBSD mount_tmpfs(8) manual page. Obtained from: NetBSD Discussed with: delphij 2010-02-16 19:59:10 +00:00			`.\"-`
			`.\" Copyright (c) 2005, 2006 The NetBSD Foundation, Inc.`
			`.\" All rights reserved.`
			`.\"`
			`.\" Redistribution and use in source and binary forms, with or without`
			`.\" modification, are permitted provided that the following conditions`
			`.\" are met:`
			`.\" 1. Redistributions of source code must retain the above copyright`
			`.\" notice, this list of conditions and the following disclaimer.`
			`.\" 2. Redistributions in binary form must reproduce the above copyright`
			`.\" notice, this list of conditions and the following disclaimer in the`
			`.\" documentation and/or other materials provided with the distribution.`
			`.\"`
			`.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS`
			.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
			`.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR`
			`.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS`
			`.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR`
			`.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF`
			`.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS`
			`.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN`
			`.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)`
			`.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE`
			`.\" POSSIBILITY OF SUCH DAMAGE.`
			`.\"`
Add a manual page for tmpfs(5). 2007-06-16 02:35:29 +00:00			`.\" $FreeBSD$`
			`.\"`
Update the bugs section. We don't consider tmpfs as experimental, though we do not claim to support all mount options equally well. Approved by: delphij@ MFC after: 3 days 2012-04-23 17:15:06 +00:00			`.Dd April 23, 2012`
Add a manual page for tmpfs(5). 2007-06-16 02:35:29 +00:00			`.Dt TMPFS 5`
			`.Os`
			`.Sh NAME`
			`.Nm tmpfs`
Complete SYNOPSIS and some cleanup. 2007-06-18 18:58:15 +00:00			`.Nd "efficient memory file system"`
Add a manual page for tmpfs(5). 2007-06-16 02:35:29 +00:00			`.Sh SYNOPSIS`
Complete SYNOPSIS and some cleanup. 2007-06-18 18:58:15 +00:00			`To compile this driver into the kernel,`
			`place the following line in your`
			`kernel configuration file:`
			`.Bd -ragged -offset indent`
			`.Cd "options TMPFS"`
			`.Ed`
			`.Pp`
			`Alternatively, to load the driver as a`
			`module at boot time, place the following line in`
			`.Xr loader.conf 5 :`
			`.Bd -literal -offset indent`
			`tmpfs_load="YES"`
			`.Ed`
Add a manual page for tmpfs(5). 2007-06-16 02:35:29 +00:00			`.Sh DESCRIPTION`
			`The`
			`.Nm`
			`driver will permit the`
			`.Fx`
			`kernel to access`
			`.Tn tmpfs`
			`file systems.`
Document more tmpfs mount options that are already available. PR: 124488 Submitted by: gahr 2008-06-12 18:49:24 +00:00			`.Sh OPTIONS`
			`The following options are available when`
			`mounting`
			`.Nm`
			`file systems:`
			`.Bl -tag -width indent`
			`.It Cm gid`
Improve descriptions for tmpfs mount options. The descriptions have been mostly obtained from NetBSD mount_tmpfs(8) manual page. Obtained from: NetBSD Discussed with: delphij 2010-02-16 19:59:10 +00:00			`Specifies the group ID of the root inode of the file system.`
			`Defaults to the mount point's GID.`
Document more tmpfs mount options that are already available. PR: 124488 Submitted by: gahr 2008-06-12 18:49:24 +00:00			`.It Cm uid`
Improve descriptions for tmpfs mount options. The descriptions have been mostly obtained from NetBSD mount_tmpfs(8) manual page. Obtained from: NetBSD Discussed with: delphij 2010-02-16 19:59:10 +00:00			`Specifies the user ID of the root inode of the file system.`
			`Defaults to the mount point's UID.`
Document more tmpfs mount options that are already available. PR: 124488 Submitted by: gahr 2008-06-12 18:49:24 +00:00			`.It Cm mode`
Improve descriptions for tmpfs mount options. The descriptions have been mostly obtained from NetBSD mount_tmpfs(8) manual page. Obtained from: NetBSD Discussed with: delphij 2010-02-16 19:59:10 +00:00			`Specifies the mode (in octal notation) of the root inode of the file system.`
			`Defaults to the mount point's mode.`
Document more tmpfs mount options that are already available. PR: 124488 Submitted by: gahr 2008-06-12 18:49:24 +00:00			`.It Cm inodes`
Improve descriptions for tmpfs mount options. The descriptions have been mostly obtained from NetBSD mount_tmpfs(8) manual page. Obtained from: NetBSD Discussed with: delphij 2010-02-16 19:59:10 +00:00			`Specifies the maximum number of nodes available to the file system.`
			`If not specified, the file system chooses a reasonable maximum based on`
			`the file system size, which can be limited with the`
			`.Cm size`
			`option.`
Document more tmpfs mount options that are already available. PR: 124488 Submitted by: gahr 2008-06-12 18:49:24 +00:00			`.It Cm size`
Improve descriptions for tmpfs mount options. The descriptions have been mostly obtained from NetBSD mount_tmpfs(8) manual page. Obtained from: NetBSD Discussed with: delphij 2010-02-16 19:59:10 +00:00			`Specifies the total file system size in bytes.`
			`If zero (the default) or a value larger than SIZE_MAX - PAGE_SIZE`
			`is given, the available amount of memory (including`
			`main memory and swap space) will be used.`
Add "maxfilesize" mount option for tmpfs to allow specifying the maximum file size limit. Default is UINT64_MAX when the option is not specified. It was useless to set the limit to the total amount of memory and swap in the system. Use tmpfs_mem_info() rather than get_swpgtotal() in tmpfs_mount() to check if there is enough memory available. Remove now unused get_swpgtotal(). Reviewed by: Gleb Kurtsou Approved by: trasz (mentor) 2010-01-29 12:09:14 +00:00			`.It Cm maxfilesize`
Improve descriptions for tmpfs mount options. The descriptions have been mostly obtained from NetBSD mount_tmpfs(8) manual page. Obtained from: NetBSD Discussed with: delphij 2010-02-16 19:59:10 +00:00			`Specifies the maximum file size in bytes.`
			`Defaults to the maximum possible value.`
Add a missing .El. Founded by: make manlint 2009-08-25 01:04:15 +00:00			`.El`
Add a manual page for tmpfs(5). 2007-06-16 02:35:29 +00:00			`.Sh EXAMPLES`
			`To mount a`
			`.Nm`
			`memory file system:`
			`.Pp`
			`.Dl "mount -t tmpfs tmpfs /tmp"`
			`.Sh SEE ALSO`
			`.Xr nmount 2 ,`
			`.Xr unmount 2 ,`
			`.Xr fstab 5 ,`
Xref mdmfs(8). 2010-02-16 20:00:20 +00:00			`.Xr mdmfs 8 ,`
Add a manual page for tmpfs(5). 2007-06-16 02:35:29 +00:00			`.Xr mount 8`
			`.Sh HISTORY`
			`The`
			`.Nm`
			`driver first appeared in`
			`.Fx 7.0 .`
			`.Sh AUTHORS`
			`.An -nosplit`
			`The`
			`.Nm`
			`kernel implementation was written by`
			`.An Julio M. Merino Vidal Aq jmmv@NetBSD.org`
			`as a Google SoC project.`
			`.Pp`
			`.An Rohit Jalan`
			`and others ported it from`
			`.Nx`
			`to`
			`.Fx .`
			`.Pp`
			`This manual page was written by`
			`.An Xin LI Aq delphij@FreeBSD.org .`
			`.Sh BUGS`
Update the bugs section. We don't consider tmpfs as experimental, though we do not claim to support all mount options equally well. Approved by: delphij@ MFC after: 3 days 2012-04-23 17:15:06 +00:00			`Some file system mount time options may not be well-supported.`