#!/bin/bash

run_quiet () {
    shift
    "$@"
}

test_zero_corruption () {
    local disk="/dev/dm-21"
    local table_fe="0 2000000 linear $disk 0"
    local table_be1="0 8000000 linear $disk 2000000"
    local table_be2="0 4000000 linear $disk 10000000"
    local table_be3="0 4000000 linear $disk 14000000"

    dmsetup create fe <<< $table_fe
    dmsetup create be1 <<< $table_be1
    dmsetup create be2 <<< $table_be2
    dmsetup create be3 <<< $table_be3

    run_quiet "" bcachefs format    \
        --error_action=panic        \
        --data_replicas=2           \
        --metadata_replicas=3       \
        --group ssd /dev/mapper/fe  \
        --group hdd /dev/mapper/be*

    mount -t bcachefs /dev/mapper/fe:/dev/mapper/be1:/dev/mapper/be2:/dev/mapper/be3 /mnt

    echo ssd > /sys/fs/bcachefs/*/options/foreground_target
    echo ssd > /sys/fs/bcachefs/*/options/promote_target
    echo hdd > /sys/fs/bcachefs/*/options/background_target

    pushd /mnt > /dev/null

    # Initial test
    dd if=/dev/urandom of=test0 bs=1M count=10 oflag=direct
    sha256sum test0 > test0.sha256
    sync

    # I/O error test
    dmsetup suspend be1
    dmsetup reload be1 <<< "0 8000000 error"
    dmsetup resume be1
    dd if=/dev/urandom of=test1 bs=1M count=10 oflag=direct
    sha256sum test1 > test1.sha256
    sync

    # Zero test
    dmsetup suspend be2
    dmsetup reload be2 <<< "0 4000000 zero"
    dmsetup resume be2
    dd if=/dev/urandom of=test2 bs=1M count=10 oflag=direct
    sha256sum test2 > test2.sha256
    sync

    # Second I/O error test
    dmsetup suspend be3
    dmsetup reload be3 <<< "0 4000000 error"
    dmsetup resume be3
    dd if=/dev/urandom of=test3 bs=1M count=10 oflag=direct
    sha256sum test3 > test3.sha256
    sync

    # Un-mount
    popd > /dev/null
    umount /mnt

    # Restore original tables
    dmsetup suspend be1
    dmsetup reload be1 <<< $table_be1
    dmsetup resume be1
    dmsetup suspend be2
    dmsetup reload be2 <<< $table_be2
    dmsetup resume be2
    dmsetup suspend be3
    dmsetup reload be3 <<< $table_be3
    dmsetup resume be3

    # Mount without be1 and files test0 + test0.sha256 are unreadable.
    pushd /mnt > /dev/null
    mount -t bcachefs -o degraded /dev/mapper/fe:/dev/mapper/be2:/dev/mapper/be3 /mnt
    bcachefs fs usage /mnt
    sha256sum -c *.sha256
    popd > /dev/null

    # Remove device with corruption, causes kernel bug + freeze FS: https://pastebin.com/gD3MsE5R
    bcachefs device remove /dev/mapper/be2
}