#!/usr/bin/env bash
#
# Test filesystem path with fio database simulation
#  - 4k blocks, 5% read, 95% write
#  - threaded mode, 128 request queue depth
#  - fewer large files, random I/O
#
# Required:
#  - FS mounted at /fiotest (or use -d / -x)
#  - 5G space free in filesystem path
#  - 'fio' installed (yum/dnf/apt)
#
# Will create:
#  - /fiotest/fio/4x0595.fio             (config)
#  - /fiotest/fio/4x0595_$(uname -r).txt (results)
#  - /fiotest/fio/cache                  (cache)
#
# SPDX-License-Identifier: MIT

_VERSION="0.0.1"
_NAME=$(basename "${0}")

# usage
function usage() {
  echo "${_NAME} version ${_VERSION}"
  echo
  echo "Usage: ${_NAME} [OPTIONS...]"
  echo
  echo " Options:"
  echo "  -d <dir>  Directory to use (default: /fiotest)"
  echo "  -o        Overwrite existing fio config"
  echo "  -x        Do not test if dir is a mount point"
  echo "  -V        Version of program"
  echo "  -h        This help text"
  echo
}

# defaults
declare FMOUNT="/fiotest"
declare _OCFG=0
declare _XMNT=1

# user input
while getopts "d:oxVh" opt; do
  case "$opt" in
    d)
      FMOUNT="${OPTARG}" ;;
    o)
      _OCFG=1 ;;
    x)
      _XMNT=0 ;;
    V)
      echo "${_NAME} version ${_VERSION}"
      exit 0 ;;
    h)
      usage
      exit 0 ;;
    *)
      echo "Unrecognized option: $OPTARG (Run '$_NAME -h' for help)"
      exit 1 ;;
  esac
done
shift $((OPTIND-1))

# strip trailing slash if present
FMOUNT=${FMOUNT%/}

# runtime vars
FDIR="${FMOUNT}/fio"
FCONF="${FDIR}/4x0595.fio"
FLOG="${FDIR}/4x0595_$(uname -r).txt"
FCACHE="${FDIR}/cache"

# ensure we can run fio properly
function preflight() {
  # fio test
  if [[ -z "$(command -v fio 2>/dev/null)" ]]; then
    echo "Install 'fio' with yum/dnf/apt first. Exiting."
    exit 99
  fi
  # mount/dir test
  if [[ $_XMNT -eq 1 ]]; then
    if ! mountpoint -q "${FMOUNT}"; then
      echo "${FMOUNT} is not a mount point, use -x to override. Exiting."
      exit 1
    fi
  else
    # -x was used
    if [[ ! -d "${FMOUNT}" ]]; then
      echo "${FMOUNT} is not a directory. Exiting."
      exit 2
    fi
  fi
  # mkdirs
  mkdir -p "${FCACHE}"
  if [[ ! -d "${FCACHE}" ]]; then
    echo "Cannot create ${FCACHE}. Exiting."
    exit 3
  fi
}

# ensure we have a fio config
function writeconf() {
  # -o was used, or does not exist
  if [[ $_OCFG -eq 1 ]] || [[ ! -f "${FCONF}" ]]; then
    cat << EOF > "${FCONF}"
;; Generic database simulation
;; - 4k blocks, 5% read, 95% write
;; - threaded mode, 128 request queue depth
;; - fewer large files, random I/O

[4x0595]
; this directory will need numjobs*size free!
directory=${FCACHE}
numjobs=4
size=1G
; run this many loops
loops=10
; instead of loops, run 10 mins
;time_based
;runtime=600
; params for 5/95 read/write randomly
thread
ioengine=libaio
iodepth=128
rw=randrw
rwmixread=5
rwmixwrite=95
randrepeat=0
bs=4k
file_service_type=random
overwrite=1
direct=1
softrandommap=1
random_generator=lfsr
invalidate=1
unlink=0
refill_buffers
group_reporting
EOF
  fi
  if [[ ! -f "${FCONF}" ]]; then
    echo "Cannot create or find ${FCONF}"
    exit 2
  fi
}

# these could fail and exit
preflight
writeconf

# do the needful
echo "Running: fio --output=${FLOG} ${FCONF}"
echo
fio --output="${FLOG}" "${FCONF}"