tmpdir-setup

#! /usr/bin/bash

usage() {
    cat <<EOF >&2
usage:
    $0 create JOBID SIZE UID  # create SIZE GiB /dev/shm/mxqd/mnt/job/$JOBID
    $0 cleanup JOBID          # cleanup
EOF
    exit 1
}

tmpdir=/scratch/local2/mxqd/tmp
mntdir=/dev/shm/mxqd/mnt/job

cmd_create() {
    (( $# == 3 )) || usage
    MXQ_JOBID=$1
    MXQ_SIZE=$2
    MXQ_UID=$3

    filename=$tmpdir/$MXQ_JOBID.tmp
    mountpoint=$mntdir/$MXQ_JOBID

    umask 006
    mkdir -p $tmpdir
    mkdir -p $mntdir

    status=1;

    if fallocate -l ${MXQ_SIZE}G $filename; then
        if loopdevice=$(losetup --find --show $filename); then
            if mkfs.ext4 \
                    -q \
                    -m 0 \
                    -E nodiscard,mmp_update_interval=300,lazy_journal_init=1,root_owner=$MXQ_UID:0 \
                    -O '64bit,ext_attr,filetype,^has_journal,huge_file,inline_data,^mmp,^quota,sparse_super2' \
                    $loopdevice \
                    && mkdir -p $mountpoint && mount -Odata=writeback,barrier=0  $loopdevice $mountpoint; then
                rmdir $mountpoint/lost+found
                status=0
            fi
            losetup -d $loopdevice
        fi
        rm $filename
    else
        test -e $filename && rm $filename
    fi
    exit $status
}

cmd_cleanup() {
    (( $# == 1 )) || usage
    MXQ_JOBID=$1

    mountpoint=$mntdir/$MXQ_JOBID

    umount -l $mountpoint
    rmdir $mountpoint
}

(( $# > 0 )) || usage
cmd="$1"
shift;
case "$cmd" in
    create)
        cmd_create "$@"
        ;;
    cleanup)
        cmd_cleanup "$@"
        ;;
    *)
        usage
        ;;
esac