Mount posixovl using fstab

Question

The following line:

/path1  /path2  posixovl    none    0   0

fails with the error:

/sbin/mount.posixovl: invalid option -- 'o'
Usage: /sbin/mount.posixovl [-F] [-S source] mountpoint [-- fuseoptions]

This is because mount.posixovl uses a non standard mount syntax, and fstab will call it assuming default mount syntax, eg.

mount.posixovl /path1 /path2 -o [whatsoever_/etc/fstab_options]

EDIT #1: Same problem, solved with an uglier hack in this linuxquestions.org Q&A titled: [SOLVED] How to get a fuse-posixovl partition mounted at bootup?

Answer 1

Thanks vehystrix for sharing your wrapper script. I recently used it to mount a directory inside a users's home. I found two issues I wanted to improve with your script:

1. renaming the original mont.posixovl binary means it could brake as soon as the packet manager of your distribution installs a new update
2. the original mount.posixovl is always started as root and it seems to ignore uid= and gid= mount options. This resulted int he filesytem being inaccessible for the user who's home it was mounted to

I slightly changed your script and saved it to /sbin/mount.fuse-posixovl instead (which correlates with the ubuntu package name), so i could use a type fuse-posixovl in fstab to mount it.

Here is the modified version of your script:

#!/bin/bash
# wrapper for mount.posixovl to conform with common mount syntax
# with this wrapper posixovl can be used in fstab
 
# location of the original mount.posixovl
origposixovl="/sbin/mount.posixovl"
 
# gather inputs
while [ $# -gt 0 ]; do
        if [[ "$1" == -* ]]; then
                # var is an input switch
                # we can only use the -o or -F switches
                if [[ "$1" == *F* ]]; then
                        optsF="-F"
                else
                        optsF=""
                fi
                if [[ "$1" == *o* ]]; then
                        shift
                        if [[ "$1" == *uid=* ]]; then
                                runas=$(getent passwd $(echo "$1" | sed -E -e 's/^.*uid=([^,]+)(,.*)?$/\1/') | cut -d: -f1)
                        fi
                        optsfuse="-- -o $1"
                else
                        optsfuse=""
                fi
                shift
        else
                # var is a main argument
                sourcedir="$1"
                shift
                if [[ "$1" != -* ]]; then
                        targetdir="$1"
                        shift
                else
                        targetdir="$sourcedir"
                fi
        fi
done
 
# verify inputs
if [ "$sourcedir" == "" ]; then
        echo "no source specified"
        exit 1
fi
if [ "$targetdir" == "" ]; then
        echo "no target specified"
        exit 1
fi
 
# build mount.posixovl command
if [[ -n "$runas" ]]; then
        su - "${runas}" -c "\"$origposixovl\" $optsF -S \"$sourcedir\" \"$targetdir\" $optsfuse"
else
        "$origposixovl" $optsF -S "$sourcedir" "$targetdir" $optsfuse
fi

and here is an example of a fstab line using it:

/home/myuser/Nextcloud/homebin            /home/myuser/bin fuse-posixovl   uid=1000,gid=1000    0 0

Answer 2

I wrote a wrapper for mount.posixovl that enables it to be used with fstab

First, rename /sbin/mount.posixovl to something else, like /sbin/mount.posixovl.orig

Finally, create a new file /sbin/mount.posixovl whith the following contents:

#!/bin/bash
# wrapper for mount.posixovl to conform with common mount syntax
# with this wrapper posixovl can be used in fstab

# location of the original mount.posixovl
origposixovl="/sbin/mount.posixovl.orig"

# gather inputs
while [ $# -gt 0 ]; do
        if [[ "$1" == -* ]]; then
                # var is an input switch
                # we can only use the -o or -F switches
                if [[ "$1" == *F* ]]; then
                        optsF="-F"
                else
                        optsF=""
                fi
                if [[ "$1" == *o* ]]; then
                        shift
                        optsfuse="-- -o $1"
                else
                        optsfuse=""
                fi
                shift
        else
                # var is a main argument
                sourcedir="$1"
                shift
                if [[ "$1" != -* ]]; then
                        targetdir="$1"
                        shift
                else
                        targetdir="$sourcedir"
                fi
        fi
done

# verify inputs
if [ "$sourcedir" == "" ]; then
        echo "no source specified"
        exit 1
fi
if [ "$targetdir" == "" ]; then
        echo "no target specified"
        exit 1
fi

# build mount.posixovl command
"$origposixovl" $optsF -S "$sourcedir" "$targetdir" $optsfuse

Naturally, set the newly created /sbin/mount.posixovl to be executeable (chmod +x /sbin/mount.posixovl)

It is useful mounting posixovl trough fstab