plan9-gpl/sys/man/4/ext2srv

.TH EXT2SRV 4
.SH NAME
ext2srv \- ext2 file system
.SH SYNOPSIS
.B ext2srv
[
.B -vrs
] [
.B -f
.I file
] [
.B -p
.I passwd
] [
.B -g
.I group
] [
.I service
]
.SH DESCRIPTION
.I Ext2srv
is a file server that interprets the Linux Second Extended File System.
A single instance of
.I ext2srv
can provide access to multiple ext2 partitions simultaneously.
.PP
.I Ext2srv
posts a file descriptor named
.I service
(default
.BR ext2 )
in the
.B /srv
directory.
To access an ext2 file system on a device, use
.B mount
with the
.I spec
argument
(see
.IR bind (1))
the name of the file holding the raw ext2 file system, typically the disk or partition.
If
.I spec
is undefined in the
.BR mount ,
.I ext2srv
will use
.I file
as the default name for the device holding the file system.
.PP
Normally
.I ext2srv
creates a pipe to act as the communications channel between
itself and its clients.
The
.B -s
flag instructs
.I ext2srv
to use its standard input and output instead.
This flag also prevents the creation of an explicit service file in
.BR /srv .
.PP
The
.B -v
flag causes verbose output for debugging, while
the
.B -r
flag (recommended) makes the file system read-only.
The optional
.B -p
and
.B -g
flags specify Unix-format password (respectively group) files
that give the mapping between the numeric user- and group-ID
numbers in the ext2 file system and the strings reported by Plan 9 status
inquiries.
.PP
There is no authentication or permission checking.
Anyone who can access the ext2 file system will have full access
to all its files, including write access if
.I ext2srv
is not started with the
.B -r
flag, irrespective of file ownership and permission flags.
.PP
Some file system state is cached in memory, and may
be flushed only when the file system is unmounted.
Therefore if
.I ext2srv
is stopped or the machine is rebooted while an ext2 file system
is still mounted,
the superblock on the device will have been marked `not valid'
(unless the
.B -r
flag was used),
and a
.I fsck
will be required before that file system may be mounted again.
.SH BUGS
There is no authentication or permission checking.
The implementation has not tracked any changes to the ext2
specification since it was written.
There may be other bugs.
It is advisable to use
.I ext2srv
in read-only mode whenever possible.
.SH AUTHOR
Bodet Laurent (bl@mime.univ-paris8.fr),
with later updates by Russ Cox and Richard Miller.