#!/bin/sh

#-----------------------------------------------------------
#
# Get proper disk to install OS
#
# 1. Check all partitions list in /proc/partitions, whether
#    there is disk had OS installed. If there is, add it to
#    the disk array.
# 2. If there is disk had OS installed, check disks list
#    generated in Step 1. Else, check all disks get from
#    /proc/partitions file. Sort them by WWN/PATH and driver
#    type, select the first one.
# 3. Select the default one: /dev/sda.
#
# Output: /tmp/xcat.install_disk
#
#-----------------------------------------------------------

install_disk=""
install_disk_file="/tmp/xcat.install_disk"

tmpdir="/tmp/xcat.getinstalldisk"
mkdir -p $tmpdir

has_awk=$(find /usr/* -name "awk")

utolcmd="sed -e y/ABCDEFGHIJKLMNOPQRSTUVWXYZ/abcdefghijklmnopqrstuvwxyz/"

tmpfile="$tmpdir/getinstalldisk_"

if [ -z "$install_disk" ]; then

    echo "[get_install_disk]Information from /proc/partitions:"
    cat /proc/partitions
    echo ""

    # Get all partitions and disks from /proc/partitions file
    if [ -z "$has_awk" ]; then
        entries=$(cat /proc/partitions | sed 's/  */ /g' | cut -d " " -f5 | grep -v "name" | grep -E '^[s|h|v]d|nvme')
    else
        entries=$(awk -F ' '  '{print $4}' /proc/partitions | grep -v "name" | grep -E '^[s|h|v]d|nvme')
    fi

    # Classify entries by DEVTYPE
    for entry in $entries; do
        DEVSIZE=$(udevadm info --attribute-walk --name=$entry|grep size| sed -e 's/[^"]*"//' -e 's/"//'|tail -n 1)
        if [ -z "$DEVSIZE" -o $DEVSIZE -lt 262144 ]; then
            # ignore small devices, that are likely remote media or similar
            continue
        fi

        if [ -z "$has_awk" ]; then
            dev_type=$(udevadm info --query=property --name=/dev/$entry | grep -i "DEVTYPE" | cut -d "=" -f2 | $utolcmd)
        else
            dev_type=$(udevadm info --query=property --name=/dev/$entry | grep -i "DEVTYPE" | awk -F = '{print $2}' | $utolcmd)
        fi

        if [ "$dev_type" == "disk" ]; then
            disks=$disks"$entry "
        elif [ "$dev_type" == "partition" ]; then
            partitions=$partitions"$entry "
        fi
    done

    mount_dir=$tmpdir"/xcat.getinstalldisk.mount"
    mkdir -p $mount_dir;

    disk_array=""

    for partition in $partitions; do
        echo "[get_install_disk]Check the partition $partition."

        if [ -e "$tmpfile${partition%%[0-9]*}" ]; then
            echo "[get_install_disk]    The disk ${partition%%[0-9]*} had OS installed, check next partition."
            continue
        fi

        # Get partition's fs_type
        if [ -z "$has_awk" ]; then
            fs_type=$(udevadm info --query=property --name=/dev/$partition | grep -i "FS_TYPE" | cut -d "=" -f2)
        else
            fs_type=$(udevadm info --query=property --name=/dev/$partition | grep -i "FS_TYPE" | awk -F = '{print $2}')
        fi

        rc=255

        # Mount partition based on fs type, if fs_type is "swap", do not mount it, jump to next partition.
        if [ -z "$fs_type" ]; then
            mount /dev/$partition $mount_dir
            rc=$?
        elif [ "$fs_type" != "swap" ]; then
            mount -t $fs_type /dev/$partition $mount_dir
            rc=$?
        fi

        # Check whether mount successfully
        if [ $rc -eq 0 ]; then
            echo "[get_install_disk]    Partition $partition mount success."

            ker_dir=$mount_dir
            if [ -d "$mount_dir/boot" ]; then
                ker_dir="$mount_dir/boot"
            fi

            # If there is kernel file, add partition's disk into disk_array
            # It seems the kernel file in ubuntu and sles are named like vmlinux, but in RH it is called vmlinuz
            # To check both vmlinux and vmlinuz, use regular expression "vmlinu*" to match them
            for i in $ker_dir/vmlinu*; do
                disk_part=${partition%%[0-9]*}
                touch "$tmpfile$disk_part"
                disk_array=$disk_array"$disk_part "
                echo "[get_install_disk]    The partition $partition has kernel file."
                break
            done

            umount -l $mount_dir || echo "[get_install_disk]    $partition umount failed."
        else
            echo "[get_install_disk]    Partition $partition mount failed or the partition is swap."
        fi
    done

    # If disk_array is not empty, make disks equal disk_array for next step to sort
    if [ "$disk_array" ]; then
        disks=$disk_array
        echo "[get_install_disk]The disks which have kernel:"
        echo "[get_install_disk]    $disks"
        echo ""
    fi

    rmdir $mount_dir;

    for file in $tmpfile*; do
        rm $file;
    done

    has_wwn=0
    has_path=0
    file_pre=""
    disk_data=""

    # Check disks which had installed OS, or check all disks in /proc/partitions
    for disk in $disks; do
        # Get disk's information: WWN, PATH and DRIVER
        disk_info=$(udevadm info --query=property --name=$disk)
        output_for_wwn=$(IFS= ;echo $disk_info | grep '\<ID_WWN\>' | cut -d "=" -f2)
        disk_wwn=$(echo $output_for_wwn | $utolcmd)
        output_for_path=$(IFS= ;echo $disk_info | grep DEVPATH | cut -d "=" -f2)
        disk_path=$(echo $output_for_path | $utolcmd)
        disk_driver=$(udevadm info --attribute-walk --name=$disk | grep DRIVERS| grep -v '""'| grep -v '"sd"'|
                    \head -n 1| sed -e 's/[^"]*"//' -e 's/"//' | $utolcmd)

        echo "[get_install_disk]The disk $disk information: "
        echo "[get_install_disk]    disk_wwn=$disk_wwn"
        echo "[get_install_disk]    disk_path=$disk_path"
        echo "[get_install_disk]    disk_driver=$disk_driver"

        # Check whether there is WWN, PATH information
        if [ "$disk_wwn" ]; then
            has_wwn=1
            file_pre="wwn"
            disk_data=$disk_wwn
        elif [ $has_wwn -eq 1 ]; then
            echo "[get_install_disk]    The disk $disk has no wwn info."
            echo "[get_install_disk]    There is other disk has wwn info, so don't record this disk."
            continue;
        elif [ "$disk_path" ]; then
            has_path=1
            file_pre="path"
            disk_data=$disk_path
        elif [ $has_path -eq 1 ]; then
            echo "[get_install_disk]    The disk $disk has no wwn or path info."
            echo "[get_install_disk]    There is other disk has path info, so don't record this disk."
            continue;
        else
           file_pre="other"
           disk_data=""
        fi

        # Sort disks by DRIVER type
        case "$disk_driver" in
        "ata_piix"*|"PMC MaxRAID"|"ahci"|"megaraid_sas")
            echo "$disk $disk_data" >> "$tmpfile""$file_pre""firstchoicedisks"
            echo "[get_install_disk]    Add disk: $disk $disk_data into $file_pre firstchoicedisks"
            ;;
        "mptsas"|"mpt2sas"|"mpt3sas")
            echo "$disk $disk_data" >> "$tmpfile""$file_pre""secondchoicedisks"
            echo "[get_install_disk]    Add disk: $disk $disk_data into $file_pre secondchoicedisks"
            ;;
        *)
            echo "$disk $disk_data" >> "$tmpfile""$file_pre""thirdchoicedisks"
            echo "[get_install_disk]    Add disk: $disk $disk_data into $file_pre thirdchoicedisks"
            ;;
        esac
    done

    for seq in first second third; do
        if [ -s $tmpfile$file_pre${seq}choicedisks ]; then
            install_file="$tmpfile$file_pre${seq}choicedisks"
            break
        fi
    done

    if [ "$install_file" ] && [ -s $install_file ]; then
        install_disk=/dev/$(cat $install_file | grep -v "^$" | sort -k 2 -b | cut -d " " -f1 | head -n 1)
        echo "[get_install_disk]The install_disk is $install_disk by sorting $file_pre and DRIVER."
    fi

    for file in $tmpfile*; do
        rm $file;
    done
fi
rm -rf $tmpdir;

# Cannot find proper disk for OS install, select the default one "/dev/sda"
if [ -z "$install_disk" ]; then
    install_disk="/dev/sda"
    echo "[get_install_disk]The default install_disk is $install_disk."
fi

# Output the result to $install_disk_file
echo $install_disk > $install_disk_file
