@node fdmount, fdrawcmd, diskseekd, Commands
@section fdmount
@pindex fdmount
@pindex fdmountd
@pindex fdlist
@pindex fdumount
@cindex automounting


@example
@code{fdmount} [@code{-l}] [@code{--list}] [@code{-d}] [@code{--daemon}] [@code{--detach}]
[@code{-i} @var{interval}] [@code{--interval} @var{interval}] [@code{-o} @var{mount-options}]
[@code{-r}] [@code{-readonly}] [@code{-s}] [@code{--sync}] [@code{--nosync}] [@code{--nodev}]
[@code{--nosuid}] [@code{--noexec}] [@code{-f}] [@code{--force}] [@code{-h}] [@code{--help}]
[@var{drivename}] [@var{mountpoint}]

@code{fdumount} [@code{-f}] [@code{--force}] [@var{drivename}]

@code{fdlist}

@code{fdmountd} [@code{-i} @var{interval}] [@code{--interval} @var{interval}] [@code{-r}]
[@code{-readonly}] [@code{-s}] [@code{--sync}] [@code{--nosync}] [@code{--nodev}]
[@code{--nosuid}] [@code{--noexec}] [@code{--help}] [@var{drivename}] [@var{mountpoint}]]

@end example


The @code{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 @code{minix}, @code{ext},
@code{ext2}, @code{xia}, and @code{msdos}, and includes special support
for disks formatted by the @code{2M} utility for MS-DOS.

It also checks whether the disk is write protected, in which case 
it is mounted read-only.

The symbolic @var{drivename} is (currently) one of @file{fd[0-7]},
corresponding to the special device files @file{/dev/fd[0-7]}. If
@var{drivename} is not specified, @file{fd0} is assumed.

The disk is mounted on the directory @var{mountpoint}, if specified, or
on @file{/fd[0-7]}.  In either case, the mount point must be an
existing, writable directory.


@strong{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}

@subsection Options

@table @code

@item -l @var{--list}
List all known drives with their symbolic name, type, and mount
status. 

@item -d @var{--daemon}
Run in daemon mode (see below).

@item --detach
Runs daemon in background, and detaches it from its tty. Messages
produced after the fork are logged to syslog.

@item -p @var{file}
@itemx --pidfile @var{file}

Dumps the process id of the daemon to
@var{file}. This makes killing the daemon easier:
@code{kill -9 `cat @var{file}`}

@item -i @var{interval}
@itemx --interval @var{interval}
Set the polling interval for daemon mode. The unit for @var{interval} is
0.1 seconds, the default value is 10 (i.e. 1 second).

@item -o @var{options}
@itemx --options @var{options}
Sets filesystem-specific options. So far, these are only available for
DOS and Ext2 disks. The following DOS options are supported:
@code{check}, @code{conv}, @code{dotsOK}, @code{debug}, @code{fat},
@code{quiet}, @code{blocksize}.  The following Ext2 options are
supported: @code{check}, @code{errors}, @code{grpid}, @code{bsdgroups},
@code{nogrpid}, @code{sysvgroups}, @code{bsddf}, @code{minixdf},
@code{resgid}, @code{debug}, @code{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.

@item -r @var{--readonly}
Mount the disk read-only. This is automatically assumed if the
disk is write protected.

@item -s @var{--sync}
Mount with the @code{SYNC} option.

@item --nosync
Mounts without the @code{SYNC} option, even when running as daemon.

@item --nodev
Mount with the @code{NODEV} option. Ignored for @code{msdos}
filesystems, otherwise always set for non-root users.

@item --nosuid
Mount with the @code{NOSUID} option. Ignored for @code{msdos}
filesystems, otherwise always set for non-root users.

@item --noexec
Mount with the @code{NOEXEC} option.

@item -f @var{--force}
Attempt a mount or unmount operation even @file{/etc/mtab} says that
the drive is already mounted, or not mounted, respectively.
This option is useful if @file{/etc/mtab} got out of sync with the
actual state for some reason.

@item -h @var{--help}
Show short parameter description

@end table

@subsection 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 @code{/fd0}, @code{/fd1},
@dots{} , @code{/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:

@itemize @bullet
@item
If a mountpoint is specified explicitly, it must be owned by the user.
@item
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.
@item
Non-msdos disks are automatically mounted with the @code{nodev} and
@code{nosuid} flags set.
@end itemize

However, @strong{do not rely on fdmount being secure at the moment}.

@subsection 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 @emph{before} removing it. In
order to limit corruption, disks are mounted with the SYNC option when
running in daemon mode, unless the @code{--nosync} flag is given.

Note that this mode has some potential drawbacks:
@itemize @bullet
@item
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.  @xref{floppycontrol}, for details.
@item
If a disk does not contain a filesystem (e.g. a tar archive),
the mount attempt may slow down initial access.
@item
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.
@end itemize

@subsection Diagnostics

@table @code

@item error opening device @var{name}

@item 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.

@item unknown filesystem type
No magic number of any of the supported filesystems (see above) 
could be identified.

@item sorry, can't figure out format (@var{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.

@item failed to mount @var{fs> <size}K-disk
The actual @code{mount} system call failed.

@item failed to unmount
The actual @code{unmount} system call failed.

@item cannot create lock file /etc/mtab~
If @file{/etc/mtab~} exists, you should probably delete it. Otherwise,
check permissions.

@item Can't access @var{mountpoint}
Most probably, the default or specified mount point does not exist.
Use mkdir.

@item @var{mountpoint} is not a directory
The mountpoint is not a directory.

@item not owner of @var{mountpoint}
Non-root users must own the directory specified as mount point.
(This does not apply for the default mount points, /fd[0-3].)

@item No write permission to @var{mountpoint}
Non-root users must have write permission on the mount point
directory.

@item Not owner of mounted directory: UID=@var{uid}
Non-root users cannot unmount if the mount point is owned
(i.e. the disk was mounted) by another user.

@item invalid drive name
Valid drive names are @file{fd0}, @file{fd1}, etc.

@item drive @var{name} does not exist
The drive does not exist physically, is unknown to the Linux kernel, or
is an unknown type.

@item Drive @var{name} is mounted already
Trying to mount a drive which appears to be mounted already.  Use the
@code{--force} option if you think this is wrong.

@item Drive @var{name} is not mounted
Trying to unmount a drive which does not appear to be mounted.  Use the
@code{--force} option if you think this is wrong.

@item ioctl(...) failed
If this occurs with the @code{FDGETDRVTYP} or @code{FDGETDRVSTAT},
ioctl's you should probably update your Linux kernel.

@item mounted @var{fs} @var{size}-disk (@var{options})
Success message.

@end table

@subsection Bugs

@itemize @bullet
@item
Fdmount should be more flexible about drive names and default
mount points (currently hard coded).

@item
Probably not very secure yet (when running suid root).
Untested with ext and xia filesystems.

@item
Can't specify filesystem type and disk layout explicitly.

@item
In daemon mode, the drive light stays on all the time.

@item
Some newer filesystem types, such as vfat are not yet supported.

@end itemize
