pmount(1)						      General Commands Manual							 pmount(1)

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  auto-
       matic 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 to lock a device by several pro-
       cesses.

       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:

       o device is a block device in /dev/

       o 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.

       o device is not already mounted according to /etc/mtab and /proc/mounts

       o if the mount point already exists, there is no device already mounted at it and the directory is empty

       o device is removable (USB, FireWire, or MMC device, or /sys/block/drive/removable is 1) or whitelisted in /etc/pmount.allow.

       o 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 opera-
	      tions 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 termi-
	      nal.

       -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  dis-
       able 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.

       o 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 pre-
	 cise 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.   More-
	 over,	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  <four-
       mond@debian.org>.

Martin Pitt							  August 27, 2004							 pmount(1)