[SOLVED] Internal drive automount

fede93 · 2016-06-30 10:03:26

Hi guys, is there a way to:
-automatically mount all /dev in /media/$USER at boot without using fstab
-unmount all previously mounted devices before shutdown or reboot
P.S: i'm running archlinux with i3 window manager.
Thanks, Federico.

Last edited by fede93 (2016-07-20 08:44:50)

Spider.007 · 2016-07-02 11:21:26

This should already be handled just fine by udisks2. This is also described in the wiki @ https://wiki.archlinux.org/index.php/Udisks

Trilby · 2016-07-02 12:10:07

Why do you want to do this "without using fstab"? That is the simplest method for handling internal drives (simplest meaning requiring no additional tools or background daemons).

fede93 · 2016-07-20 08:39:21

Spider.007 wrote:

This should already be handled just fine by udisks2. This is also described in the wiki @ https://wiki.archlinux.org/index.php/Udisks

I tried to use udisks2 and it worked perfectly, but I wanted to recreate its behaviour with my bare hands .

Trilby wrote:

Why do you want to do this "without using fstab"? That is the simplest method for handling internal drives (simplest meaning requiring no additional tools or background daemons).

Because i want something more dynamic .

I've found a way to auto mount/unmount usb drives in /media instead of internal partitions, but the logic is the same.
So, here is what i've come up to:
-In /lib/systemd/system/systemd-udevd.service I've changed the option MountFlags from slave to shared
-I've created a udev rule in /etc/udev/rules.d/ named 99-usb-handler.rules

ATTRS{removable}=="0", GOTO="usb-storage-end"
ENV{ID_FS_TYPE}=="", ENV{ID_USB_DRIVER}!="usb-storage", ENV{ID_BUS}!="usb", ENV{DEVTYPE}!="usb-device", GOTO="usb-storage-end"
ACTION=="add|remove", KERNEL=="s[a-z]*[0-9]", SUBSYSTEM=="block", RUN+="/etc/udev/usb-handler"
LABEL="usb-storage-end"

-I've created a bash script in /etc/udev/ named usb-handler, which handles the mount/unmount operations, and I've made it executable (chmod +x /etc/udev/usb-handler)

#!/bin/bash

function getMountpoint() {
	i=0;
	dirs=($(ls -S /media | grep -P "^($1)_[1-9]+$|^($1)$"));
	while ((i < ${#dirs[@]})) && mountpoint -q /media/${dirs[$i]}; do
		i=$(($i+1));
	done
	if ((${#dirs[@]} == 0)); then
		mountpoint=$1;
	elif (($i < ${#dirs[@]})); then
		mountpoint=${dirs[$i]};
	else
		lastChar=${dirs[$i-1]##*_};
		if [ $lastChar == $1 ]; then
			mountpoint=$1_1;
		else
			mountpoint=${dirs[$i-1]%_*}_$(($lastChar+1));
		fi
	fi
	if mountpoint -q /media/$mountpoint; then
		echo $(getMountpoint $mountpoint);
	else
		echo $mountpoint;
	fi
	exit 0;	
}

log="\n[$(date +%D-%T:%3N)] -> pid $$: waiting for mutex";
#This is from preventing udev to go in  race condition during boot
while ! /usr/bin/mutex lock /var/lock/usb-handler-lock $$; do 
	:
done ;
log+="\n[$(date +%D-%T:%3N)] -> pid $$: done waiting";
WHITESPACES=$(printf "%-23s" " ");
if ! [ -d /media ]; then
	mkdir /media;
fi	
if [ $ACTION == add ]; then
	log+="\n[$(date +%D-%T:%3N)] -> $DEVNAME has been added. Trying to mount it";
	if [ ! -z $ID_FS_LABEL ]; then
		mountpoint=/media/$(getMountpoint $ID_FS_LABEL);  	
       	else
       		mountpoint=/media/$(getMountpoint $ID_FS_UUID);
	fi
	if mkdir $mountpoint; then
		log+="\n[$(date +%D-%T:%3N)] -> no matching mountpoint found\n[$(date +%D-%T:%3N)] -> creating $mountpoint";
	else
		log+="\n[$(date +%D-%T:%3N)] -> matching mountpoint found in $mountpoint";
	fi			
       	if mount -t $ID_FS_TYPE $DEVNAME $mountpoint; then
       		log+="\n[$(date +%D-%T:%3N)] -> mounted $DEVNAME to $mountpoint";
       	else
       		rmdir $mountpoint;
       		log+="\n[$(date +%D-%T:%3N)] -> Error: cannot mount $DEVNAME to $mountpoint with $ID_FS_TYPE filesystem";
		log+="\n[$(date +%D-%T:%3N)] -> deleted $mountpoint";
       		echo -e "$log" >> /var/log/usb-handler.log
       		exit 1;	
       	fi
	log+="\n${WHITESPACES// /' '} -> UUID: $ID_FS_UUID, LABEL: $ID_FS_LABEL, FS: $ID_FS_TYPE";
else
	log+="\n[$(date +%D-%T:%3N)] -> $DEVNAME has been removed. Trying to unmount it";
	mountpoint=$(cat /proc/mounts | grep -w $DEVNAME | awk '{print $2}')
	if [ $mountpoint != "" ]; then
		umount $mountpoint;
		rm -r $mountpoint/;
		log+="\n[$(date +%D-%T:%3N)] -> unmounted $DEVNAME from $mountpoint";		
		log+="\n[$(date +%D-%T:%3N)] -> deleted $mountpoint";
	else
		log+="\n[$(date +%D-%T:%3N)] -> $DEVNAME is not mounted";
		exit 1;	
	fi
fi
echo -e "$log" >> /var/log/usb-handler.log;
exit 0;

-I've downloaded a bash script for preventing race conditions from http://wiki.grzegorz.wierzowiecki.pl/code:mutex-in-bash, renamed to mutex and placed it in /usr/bin (remember to made it executable)
I'm a lazy human being, so I've written the code only to accomplish the job. I know for sure that in here there are people more talented than me, so i beg you to give me any advice on how i can improve the script or the rule.
Hope it helps.
Regards, Federico.

References:
http://www.reactivated.net/writing_udev_rules.html
https://wiki.archlinux.org/index.php/Udev
http://wiki.grzegorz.wierzowiecki.pl/code:mutex-in-bash

Alad · 2016-07-20 09:20:04

Wow. There's much simpler means in achieving this if you use the right tools—parsing ls and mount are anything but the right tools. Mounting from udev also wouldn't work with long running process, like mount.ntfs.

Read the following man pages: findmnt, mount, udev, udevadm, lsblk, flock

Note that if you didn't dismiss the fstab idea, you could do automount with the correct user permissions in about 5 lines of bash.

Last edited by Alad (2016-07-20 09:29:18)

Arch Linux

#1 2016-06-30 10:03:26

[SOLVED] Internal drive automount

#2 2016-07-02 11:21:26

Re: [SOLVED] Internal drive automount

#3 2016-07-02 12:10:07

Re: [SOLVED] Internal drive automount

#4 2016-07-20 08:39:21

Re: [SOLVED] Internal drive automount

#5 2016-07-20 09:20:04

Re: [SOLVED] Internal drive automount

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