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(fdutils.info)fdmount
fdmount
=======
`fdmount' [`-l'] [`--list'] [`-d'] [`--daemon'] [`--detach']
[`-i' INTERVAL] [`--interval' INTERVAL] [`-o' MOUNT-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'] [`--nosync'] [`--nodev']
[`--nosuid'] [`--noexec'] [`--help'] [DRIVENAME] [MOUNTPOINT]]
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 `2M' utility for MS-DOS.
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]',
corresponding 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 specified, or on
`/fd[0-7]'. In either case, the mount point must be an existing,
writable directory.
*Due to a bug in the floppy driver (?), the polling interval (-i
flag) must be longer than the spindown offset. Thus you need to do (for
example) floppycontrol -spindown 99 before starting fdmountd in daemon
mode*
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 FILE'
`--pidfile FILE'
Dumps the process id of the daemon to FILE. This makes killing the
daemon easier: `kill -9 `cat FILE`'
`-i INTERVAL'
`--interval INTERVAL'
Set the polling interval for daemon mode. The unit for INTERVAL is
0.1 seconds, the default value is 10 (i.e. 1 second).
`-o OPTIONS'
`--options OPTIONS'
Sets filesystem-specific options. So far, these are only available
for DOS and Ext2 disks. The following DOS options are supported:
`check', `conv', `dotsOK', `debug', `fat', `quiet', `blocksize'.
The following Ext2 options are supported: `check', `errors',
`grpid', `bsdgroups', `nogrpid', `sysvgroups', `bsddf', `minixdf',
`resgid', `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 assumed if the
disk is write protected.
`-s -SYNC'
Mount with the `SYNC' option.
`--nosync'
Mounts without the `SYNC' option, even when running 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. Default 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 moment*.
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. Note: floppycontrol for
details.
* 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 always 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 it may have a format wich is unsupported
by the FDC or the 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 incompatible 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 kernel.
`failed to mount FS> <SIZEK-disk'
The actual `mount' system call failed.
`failed to unmount'
The actual `unmount' 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'
The 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', etc.
`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 the `FDGETDRVTYP' or `FDGETDRVSTAT', ioctl's
you should probably update your Linux kernel.
`mounted FS SIZE-disk (OPTIONS)'
Success message.
Bugs
----
* Fdmount should be more flexible about drive names and default
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.
* Some newer filesystem types, such as vfat are not yet supported.
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