How to display quota limit on btrfs subvolume?

I cannot determine how to get the quota limit which is currently set on a btrfs subvolume. The btrfs wiki on quota doesn't seem to show this.

This is what I think I know:

• set a quota: btrfs qgroup limit 21G /path
• check used space: btrfs qgroup show /path

But how to check the already set limit?

Solution 1:

Use options -r and -e:

btrfs qgroup show -pcre /path

Solution 2:

I created a simple script that will show the quota limit for each sub-volume in the specified path and the used space too. The syntax is pretty simple:

./quota.sh path

To print the used space for all sub-volumes use the -a flag:

./quota.sh path -a

Don't forget to add execution permissions to the script.

Script:

#! /bin/sh
volumes=$(btrfs subvolume list  $1 | cut -d " " -f 9 )
snapshots=$(btrfs subvolume list -s  $1 | cut -d " " -f 14 )
regsnap=$(echo $snapshots | sed 's/ /,/g')
normalv=$(echo $volumes | sed "s/\($regsnap\)//g" )

if [ ! -z "$snapshots" ] ; then
    echo SNAPSHOTS
for p in $snapshots; do 
    quot=$(btrfs qgroup show -rF $1/$p | tail -1)
    if [ -z $2 ]; then
        (echo $quot | grep -q none) || echo $p $quot
    else
     [ "$2" == "-a" ] && echo $p $quot
    fi
done
fi

if [ ! -z "$normalv" ] ; then
    echo SUBVOLUMES
for p in $normalv; do 
    quot=$(btrfs qgroup show -rF $1/$p | tail -1)
    if [ -z $2 ]; then
        (echo $quot | grep -q none) || echo $p $quot
    else
     [ "$2" == "-a" ] && echo $p $quot
    fi
done

fi

It will print first the traditional sub-volumes and below the snapshots volumes. Sample output:

SNAPSHOTS
apple 0/258 1.32MiB 16.00KiB 20.00MiB
SUBVOLUMES
citrus/orange 0/256 1.32MiB 16.00KiB 20.00MiB