NAME¶
mount.lockfs - helper script for the mount command
SYNOPSIS¶
mount.lockfs FILESYSTEM MOUNTPOINT -o
MOUNTOPTIONS
DESCRIPTION¶
/sbin/mount.lockfs is a symlink to
/lib/bilibop/lockfs_mount_helper. It is used as an helper program by
the
mount(8) command for the '
lockfs' filesystem type entries in
/etc/fstab. This script cannot be run manually, and fails if the root
filesystem is not already managed by
bilibop-lockfs. The expected way
to run it and how it does its job are the followings:
- 1.
- Enable bilibop-lockfs: set the BILIBOP_LOCKFS
variable to true in bilibop.conf(5) and reboot the computer;
or reboot the computer and append the 'lockfs' kernel parameter to
the boot commandline.
- 2.
- One time the future '/' is set as an aufs(5)
mountpoint from into the initramfs environment, the temporary and writable
fstab(5) on it is modified to replace filesystem types of some
entries by 'lockfs'. Options are also modified to remember the
original fstype.
- 3.
- One time the aufs mountpoint is the new root filesystem,
initscripts are executed: fstab(5) is parsed by 'mount
-a', and then mount(8) calls mount.lockfs with the
proper arguments when a 'lockfs' fstype is encountered.
- 4.
- mount.lockfs parses arguments and checks if the
filesystem has been whitelisted in bilibop.conf(5), or not. If it
is the case, the filesystem is mounted normally and the fstab entry is
modified to reflect the actual mount call. If neither the filesystem nor
the mountpoint have been whitelisted, then the filesystem is mounted
elsewhere and readonly, a temporary filesystem is mounted with proper
options, size, permissions and ownership, and an aufs is mounted on the
MOUNTPOINT given as argument with the lower/readonly and
upper/writable branches previously set. The fstab entry is replaced by
three lines reflecting the actual mount calls. If something fails,
mount.lockfs acts as if the filesystem was whitelisted. See
/usr/share/doc/bilibop-lockfs/README.Debian for details.
OPTIONS¶
lockfs_mount_helper uses options and arguments as they are given by
mount(8) after it has parsed the corresponding
fstab(5) entry.
So, options and arguments are mandatory and come in the following order:
- FILESYSTEM
- Corresponding to the first field in fstab. This must be a
block device, or a symlink to a block device. If this field is given with
one of the UUID=* or LABEL=* formats, then the mount command
translates it to the corresponding device name before to call the helper
program.
- MOUNTPOINT
- Corresponding to the second field in fstab.
- -o MOUNTOPTIONS
- Corresponding to the fourth field in fstab. The mount
options are parsed by the helper script: if fstype=* is
encountered, it is removed from the options and used to mount the readonly
branch with this filesystem type. If ro, noexec,
nosuid or nodev options are encountered, they are added to
the list of mount options of the writable branch.
FILES¶
/etc/fstab
/lib/bilibop/lockfs_mount_helper
/usr/share/doc/bilibop-lockfs/README.Debian
SEE ALSO¶
aufs(5),
bilibop(7),
bilibop.conf(5),
fstab(5),
mount(8)
AUTHOR¶
This manual page has been written by Bilibop Project
<quidame@poivron.org>.