bindfs-120-repro.sh

#!/bin/sh
# See the validate_env function for dependencies

if [ $# -lt 2 ]; then
  echo "Usage: [testing directory] [mirror user]";
  echo "Make sure the testing directory can be access by both mirror user and this script's user"
  exit 1;
fi

export test_dir="$(realpath $1)"
export mirror_user="$2"

mkdir -p $test_dir

# Make sure everything goes away when done
trap "umount -l ${test_dir}/b; trap - SIGTERM; kill -- -$$" SIGINT SIGTERM EXIT

check_cmd() {
  cmd="$1"
  command -v $cmd > /dev/null;
  if [ $? -eq 1 ]; then echo "==> You don't have $cmd, exiting."; exit 1; fi
}

validate_env() {
  set +e
  check_cmd bindfs
  check_cmd sudo
  check_cmd strace
  check_cmd find
  check_cmd xargs
  check_cmd umount
  check_cmd bash

  ls "$test_dir" > /dev/null
  if [ $? -ne 0 ]; then
    echo "==> Unable to access test dir as script user ($(whoami)), exiting";
    exit 1;
  fi

  if [ "$(id -u)" -eq "$(id -u ${mirror_user})" ]; then
    echo "==> Mirror user must be different than the user running this script, exiting";
    exit 1;
  fi

  echo "==> Changing to user '$mirror_user' via sudo, may prompt sudo password:"
  sudo -u "$mirror_user" echo > /dev/null
  if [ $? -ne 0 ]; then echo "==> Unable to switch to mirror user with sudo, exiting"; exit 1; fi

  sudo -u "$mirror_user" ls "$test_dir" > /dev/null
  if [ $? -ne 0 ]; then
    echo "==> Unable to access test dir as mirror user (${mirror_user}), exiting";
    exit 1;
  fi
}

setup() {
  set -e
  mkdir -p "$test_dir"
  cd "$test_dir"
  echo -n "Setting up..."
  mkdir -p a b
  bindfs --mirror=$mirror_user a/ b/
  sleep 1 # Wait for bindfs to start
  mkdir -p b/sub/
  chmod 777 "$test_dir"

  filecount="$(find b/sub/ -type f | wc -l)"

  if [ $filecount -lt 20000 ]; then
    for f in {1..20000}; do touch b/sub/$f; done
  fi

  echo "done"
}

statter() {
  set -e
  while true; do
    find $1 -print0 | xargs -0 -n 100 -P 100 stat 2>/dev/null >/dev/null;
  done > /dev/null
}

try_for_error() {
  echo "Trying to produce error"

  set +e
  while true; do
    strace -o /tmp/bindfs-repro-strace1 rm -f "${test_dir}/b/foo";
    if [ $? -ne 0 ]; then
      echo -e "\n==> Successfully reproduced: Error occured in rm, see /tmp/bindfs-repro-strace1";
      break;
    fi

    strace -o /tmp/bindfs-repro-strace2 touch "${test_dir}/b/foo";
    if [ $? -ne 0 ]; then
      echo -e "\n==> Successfully reproduced: Error occured in touch, see /tmp/bindfs-repro-strace2";
      break;
    fi
  done
}

validate_env
setup
cd "$test_dir"
sudo -u "$mirror_user" bash -c "$(declare -f statter); statter ${test_dir}/b &"
echo "C-c to stop, will automatically stop on error"
try_for_error