Provided by: pmount_0.9.23-6_amd64 
NAME
pmount - mount arbitrary hotpluggable devices as normal user
SYNOPSIS
pmount [ options ] device
pmount [ options ] device label
pmount --lock [ options ] device pid
pmount --unlock [ options ] device pid
pmount
DESCRIPTION
pmount ("policy mount") is a wrapper around the standard mount program which permits
normal users to mount removable devices without a matching /etc/fstab entry.
pmount also supports encrypted devices which use dm-crypt and have LUKS metadata. If a
LUKS-capable cryptsetup is installed, pmount will use it to decrypt the device first and
mount the mapped unencrypted device instead.
pmount is invoked like this:
pmount device [ label ]
This will mount device to a directory below /media if policy is met (see below). If label
is given, the mount point will be /media/label, otherwise it will be /media/device.
The device will be mounted with the following flags:
async,atime,nodev,noexec,noauto,nosuid,user,rw
Some applications like CD burners modify a raw device which must not be mounted while the
burning process is in progress. To prevent automatic mounting, pmount offers a locking
mechanism: pmount --lock device pid will prevent the pmounting of device until it is
unlocked again using pmount --unlock device pid. The process id pid assigns the lock to a
particular process; this allows one to lock a device by several processes.
During mount, the list of locks is cleaned, i. e. all locks whose associated process does
not exist any more are removed. This prevents forgotten indefinite locks from crashed
programs.
Running pmount without arguments prints the list of mounted removable devices, a bit in
the fashion of mount (1).
Please note that you can use labels and uuids as described in fstab (5) for devices
present in /etc/fstab. In this case, the device name need to match exactly the
corresponding entry in /etc/fstab, including the LABEL= or UUID= part.
Important note for Debian: The permission to execute pmount is restricted to members of
the system group plugdev. Please add all desktop users who shall be able to use pmount to
this group by executing
adduser user plugdev
(as root).
POLICY
The mount will succeed if all of the following conditions are met:
• device is a block device in /dev/
• device is not in /etc/fstab (if it is, pmount executes mount device as the calling user
to handle this transparently). See below for more details.
• device is not already mounted according to /etc/mtab and /proc/mounts
• if the mount point already exists, there is no device already mounted at it and the
directory is empty
• device is removable (USB, FireWire, or MMC device, or /sys/block/drive/removable is 1)
or whitelisted in /etc/pmount.allow.
• device is not locked
OPTIONS
-r, --read-only
Force the device to be mounted read only. If neither -r nor -w is specified, the
kernel will choose an appropriate default.
-w, --read-write
Force the device to be mounted read/write. If neither -r nor -w is specified, the
kernel will choose an appropriate default.
-s, --sync
Mount the device with the sync option, i. e. without write caching. Default is
async (write-back). With this option, write operations are much slower and due to
the massive increase of updates of inode/FAT structures, flash devices may suffer
heavily if you write large files. This option is intended to make it safe to just
rip out USB drives without proper unmounting.
-A, --noatime
Mount the device with the noatime option. Default is atime.
-e, --exec
Mount the device with the exec option. Default is noexec.
-t filesystem, --type filesystem
Mount as specified file system type. The file system type is automatically
determined if this option is not given. See at the bottom for a list of currently
supported filesystems.
-c charset, --charset charset
Use given I/O character set (default: utf8 if called in an UTF-8 locale, otherwise
mount default). This corresponds with the mount option iocharset (or nls for NTFS).
This option is ignored for file systems that do not support setting the character
set (see mount (8) for details). Important note: pmount will now mount VFAT
filesystems with iocharset=iso8859-1 as iocharset=utf8 currently makes the
filesystem case-sensitive (which is pretty bad...).
-u umask, --umask umask
Use specified umask instead of the default one. For UDF, the default is '000', for
VFAT and NTFS the default is '077'. This value is ignored for file systems which do
not support setting an umask. Note that you can use a value of 077 to forbid anyone
else to read/write the files, 027 to allow your group to read the files and 022 to
allow anyone to read the files (but only you can write).
--dmask dmask
--fmask fmask
Some filesystems (essentially VFAT and HFS) supports separate umasks (see the -u
option just above) for directories and files, to avoid the annoying effect of
having all files executable. For these filesystems, you can specify separately the
masks using these options. By default, fmask is umask without all executable
permissions and dmask is umask. Most of the times, these settings should just do
what you want, so there should be seldom any need for using directly the --fmask
and --dmask options.
-p file --passphrase file
If the device is encrypted (dm-crypt with LUKS metadata), read the passphrase from
specified file instead of prompting at the terminal.
-h, --help
Print a help message and exit successfully.
-d, --debug
Enable verbose debug messages.
-V, --version
Print the current version number and exit successfully.
FILES
/etc/pmount.allow
List of devices (one device per line) which are additionally permitted for
pmounting. Globs, such as /dev/sda[123] are permitted. See see glob (7) for a more
complete syntax.
SEE ALSO
pumount(1), mount(8)
SUPPORTED FILESYSTEMS
For now, pmount supports the following filesystems: udf, iso9660, vfat, ntfs, hfsplus,
hfs, ext3, ext2, ext4, reiserfs, reiser4, xfs, jfs and omfs. They are tried sequentially
in that exact order when the filesystem is not specified.
Additionally, pmount supports the filesystem types ntfs-fuse and ntfs-3g to mount NTFS
volumes respectively with ntfsmount (1) or ntfs-3g (1). If the file /sbin/mount.ntfs-3g is
found, then pmount will mount NTFS filestystems with type ntfs-3g rather than plain ntfs.
To disable this behavior, just specify -t ntfs on the command-line, as this happens only
for autodetection.
MORE ABOUT FSTAB
pmount now fully resolve all symlinks both in its input and in the /etc/fstab file, which
means that if /dev/cdrom is a symlink to /dev/hdc and you try to mount /dev/hdc directly,
pmount will delegate this to mount(1). This is a feature, and it contrasts with previous
unclear behavior of pmount about symlinks in /etc/fstab.
KNOWN ISSUES
Though we believe pmount is pretty much free from security problems, there are quite a few
glitches that probably will never be fixed.
• pmount needs to try several different times to mount to get the filesystem right in the
end; it is vital that pmount does know which precise filesystem to mount in order to
give it the right options not to cause security holes. This is rather different from the
behaviour of mount with the -t auto options, which can have a look at the device it is
trying to mount and find out what its filesystem is. pmount will never try to open a
device and look at it to find out which filesystem it is, as it might open quite a few
security holes. Moreover, the order in which the filesystems are tried are what we
could call the most commonly used filesystems on removable media. This order is unlikely
to change as well. In particular, that means that when you mount an ext3 filesystem
using pmount, you might get a lot of fs-related kernel error messages. Sorry !
NOTE: Starting from version 0.9.17, pmount uses the same mechanism as mount (1) to
autodetect the filesystem type, so this kind of problems should not happen anymore.
AUTHOR
pmount was originally developed by Martin Pitt <martin.pitt@canonical.com>. It is now
maintained by Vincent Fourmond <fourmond@debian.org>.