fdmount
Hurricane Electric Internet Services
NAME
fdmount - Floppy disk mount utility
SYNOPSIS
fdmount [-l] [--list] [-d] [--daemon] [--detach] [-i
interval ] [--interval interval ] [-o options ] [-r]
[--readonly] [-s] [--sync] [--nosync] [--nodev] [--nosuid]
[--noexec] [-f] [--force] [-h] [--help] [drivename
[mountpoint] ]
fdumount [-f] [--force] [drivename]
fdlist
fdmountd [-i interval ] [--interval interval ] [-r]
[--readonly] [-s] [--sync] [--nodev] [--nosuid] [--noexec]
[drivename [mountpoint] ]
DESCRIPTION
The fdmount program mounts a floppy disk in the specified
drive. It tries to figure out the exact format and
filesystem type of the disk from data in the disk's boot
sector or super block and the auto-detected track layout.
Currently, fdmount supports the filesystems minix, ext,
ext2, xia, and msdos, and includes special support for
disks formatted by the ms-dos 2M utility.
It also checks whether the disk is write protected, in
which case it is mounted read-only.
The symbolic drivename is (currently) one of fd[0-7], cor-
responding to the special device files /dev/fd[0-7]. If
drivename is not specified, fd0 is assumed.
The disk is mounted on the directory mountpoint, if speci-
fied, or on /fd[0-7]. In either case, the mount point
must be an existing, writable directory.
OPTIONS
-l --list
List all known drives with their symbolic name,
type, and mount status.
-d --daemon
Run in daemon mode (see below).
--detach
Runs daemon in background, and detaches it from its
tty. Messages produced after the fork are logged to
syslog.
-p --pidfile file
Dumps the process id of the daemon to file. This
makes killing the daemon easier: kill -9 `cat file`
-i --interval interval
Set the polling interval for daemon mode. Unit is
0.1 seconds, default is 10 (1 second).
-o --options options
Sets filesystem-specific options. So far, these are
only available for DOS and Ext2 disks. The follow-
ing DOS options are supported: check, conv, dotsOK,
debug, fat, quiet, blocksize. The following Ext2
options are supported: check, errors, grpid, bsd-
groups, nogrpid, sysvgroups, bsddf, minixdf, res-
gid, debug, nocheck . When running as a daemon,
options not applying to the disk that is inserted
(because of its filesystem type) are not passed to
mount.
-r --readonly
Mount the disk read-only. This is automatically as-
sumed if the disk is write protected.
-s --sync
Mount with the SYNC option.
--nosync
Mounts without the SYNC option, even when not run-
ning as daemon.
--nodev
Mount with the NODEV option. Ignored for msdos
filesystems, otherwise always set for non-root
users.
--nosuid
Mount with the NOSUID option. Ignored for msdos
filesystems, otherwise always set for non-root
users.
--noexec
Mount with the NOEXEC option.
-f --force
Attempt a mount or unmount operation even /etc/mtab
says that the drive is already mounted, or not
mounted, respectively. This option is useful if
/etc/mtab got out of sync with the actual state for
some reason.
-h --help
Show short parameter description
SECURITY
When mounting on the default mount point, the mount
points' owner is set to the current user, and the access
flags according to the user's umask. For a specified
mountpoint, owner and permissions are left unchanged. De-
fault mount points are called /fd0, /fd1, ... , /fd7 .
The user running fdmount must have read access to the
floppy device for read only mounts, and read/write access
for read/write mounts.
Fdmount can be run suid root, allowing users to mount
floppy disks. The following restrictions are placed upon
non-root users:
If a mountpoint is specified explicitly, it must be owned
by the user.
A user may only unmount a disk if the mount point is owned
by the user, or if it the disk has been mounted by the
same user.
non-msdos disks are automatically mounted with the nodev
and nosuid flags set.
However, Do not rely on fdmount being secure at the mo-
ment.
DAEMON MODE
In daemon mode, the specified drive is periodically
checked and if a disk is inserted, it is automatically
mounted.
When the disk is removed, it is automatically unmounted.
However, it is recommended to unmount the disk manually
before removing it. In order to limit corruption, disks
are mounted with the SYNC option when running in daemon
mode, unless the --nosync flag is given.
Note that this mode has some potential drawbacks:
Some floppy drives have to move the drive head physically
in order to reset the disk change signal. It is strongly
recommended not to use daemon mode with these drives. Re-
fer to the floppycontrol(1) documentation for details.
It is not possible to specify special options, like
--readonly, to modify the mount process.
If a disk does not contain a filesystem (e.g. a tar
archive), the mount attempt may slow down initial access.
As fdmount cannot identify the user trying to use the disk
drive, there is no way to protect privacy. Disks are al-
ways mounted with public access permissions set.
DIAGNOSTICS
error opening device <name>
error reading boot/super block
fdmount failed to read the first 1K of the disk.
The disk might be damaged, unformatted, or have a
format unsupported by the FDC/Linux kernel.
unknown filesystem type
No magic number of any of the supported filesystems
(see above) could be identified.
sorry, can't figure out format (<fs> filesystem)
The size of the filesystem on the disk is incompat-
ible with the track layout detected by the kernel
and an integer number of tracks. This may occur if
the filesystem uses only part of the disk, or the
track layout was detected incorrectly by the ker-
nel.
failed to mount <fs> <size>K-disk
The actual mount(2) system call failed.
failed to unmount
The actual unmount(2) system call failed.
cannot create lock file /etc/mtab~
If /etc/mtab~ exists, you should probably delete
it. Otherwise, check permissions.
Can't access <mountpoint>
Most probably, the default or specified mount point
does not exist. Use mkdir.
<mountpoint> is not a directory
not owner of <mountpoint>
Non-root users must own the directory specified as
mount point. (This does not apply for the default
mount points, /fd[0-3].)
No write permission to <mountpoint>
Non-root users must have write permission on the
mount point directory.
Not owner of mounted directory: UID=<uid>
Non-root users cannot unmount if the mount point is
owned (i.e. the disk was mounted) by another user.
invalid drive name
Valid drive names are fd0, fd1, fd2, fd3, fd4, fd5,
fd6, fd7
drive <name> does not exist
The drive does not exist physically, is unknown to
the Linux kernel, or is an unknown type.
Drive <name> is mounted already
Trying to mount a drive which appears to be mounted
already. Use the --force option if you think this
is wrong.
Drive <name> is not mounted
Trying to unmount a drive which does not appear to
be mounted. Use the --force option if you think
this is wrong.
ioctl(...) failed
If this occurs with FDGETDRVTYP or FDGETDRVSTAT,
you should probably update your Linux kernel.
mounted <fs> <size>K-disk (<options>)
Success message.
BUGS
chown() fails for non-msdos filesystems mounted read-only,
so the mount point may have the wrong owner.
Fdmount should be more flexible about drive names and de-
fault mount points (currently hard coded).
Probably not very secure yet (when running suid root).
Untested with ext and xia filesystems.
Can't specify filesystem type and disk layout explicitly.
In daemon mode, the drive light stays on all the time.
FILES
/dev/fd[0-7] - Floppy devices
/etc/mtab - Mounted filesystems table
AUTHORS
Rainer Zimmermann, zimmerm@mathematik.uni-marburg.de Alain
Knaff, Alain.Knaff@inrialpes.fr
SEE ALSO
mount(1), mmount(1), superformat(1), floppycontrol(1),
setfdprm(1)
Hurricane Electric Internet Services
Copyright (C) 1998
Hurricane Electric.
All Rights Reserved.