tests/test-cache-max-size.sh

   1 #!/usr/bin/env bash
   2 # nbdkit
   3 # Copyright (C) 2018 Red Hat Inc.
   4 #
   5 # Redistribution and use in source and binary forms, with or without
   6 # modification, are permitted provided that the following conditions are
   7 # met:
   8 #
   9 # * Redistributions of source code must retain the above copyright
  10 # notice, this list of conditions and the following disclaimer.
  11 #
  12 # * Redistributions in binary form must reproduce the above copyright
  13 # notice, this list of conditions and the following disclaimer in the
  14 # documentation and/or other materials provided with the distribution.
  15 #
  16 # * Neither the name of Red Hat nor the names of its contributors may be
  17 # used to endorse or promote products derived from this software without
  18 # specific prior written permission.
  19 #
  20 # THIS SOFTWARE IS PROVIDED BY RED HAT AND CONTRIBUTORS ''AS IS'' AND
  21 # ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
  22 # THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
  23 # PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL RED HAT OR
  24 # CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  25 # SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  26 # LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
  27 # USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  28 # ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  29 # OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  30 # OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31 # SUCH DAMAGE.
  32
  33 source ./functions.sh
  34 set -e
  35 set -x
  36
  37 # Check that this is a Linux-like system supporting /proc/$pid/fd.
  38 requires test -d /proc/self/fd
  39 requires qemu-io --version
  40 # Need the stat command from coreutils.
  41 requires stat --version
  42
  43 sock=`mktemp -u`
  44 d=cache-max-size.d
  45 rm -rf $d
  46 mkdir -p $d
  47 cleanup_fn rm -rf $d
  48 cleanup_fn rm -f $sock
  49
  50 # Create a cache directory.
  51 mkdir $d/cache
  52 TMPDIR=$d/cache
  53 export TMPDIR
  54
  55 # Create an empty base image.
  56 truncate -s 1G $d/cache-max-size.img
  57
  58 # Run nbdkit with the caching filter and a low size limit to ensure
  59 # that the reclaim code is exercised.
  60 start_nbdkit -P $d/cache-max-size.pid -U $sock \
  61              --filter=cache \
  62              file $d/cache-max-size.img \
  63              cache-max-size=10M cache-on-read=true
  64
  65 # Write > 10M to the plugin.
  66 qemu-io -f raw "nbd+unix://?socket=$sock" \
  67         -c "w -P 0 0 10M" \
  68         -c "w -P 0 20M 10M" \
  69         -c "r 20M 10M" \
  70         -c "r 30M 10M" \
  71         -c "w -P 0 40M 10M"
  72
  73 # We can't use ‘du’ on the cache directory because the cache file is
  74 # deleted by the filter, and so is only accessible via /proc/$pid/fd.
  75 # Get the /proc link to the cache file, and the size of it in bytes.
  76 fddir="/proc/$( cat $d/cache-max-size.pid )/fd"
  77 ls -l $fddir ||:
  78 fd="$fddir/$( ls -l $fddir | grep $TMPDIR/ | head -1 | awk '{print $9}' )"
  79 stat -L $fd
  80 size=$(( $(stat -L -c '%b * %B' $fd) ))
  81
  82 if [ "$size" -gt $(( 11 * 1024 * 1024 )) ]; then
  83     echo "$0: cache size is larger than 10M (actual size: $size bytes)"
  84     exit 1
  85 fi