tests/test-cow.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 requires guestfish --version
  38
  39 sock=`mktemp -u`
  40 files="cow-base.img cow-diff.qcow2 $sock cow.pid"
  41 rm -f $files
  42 cleanup_fn rm -f $files
  43
  44 # Create a base image which is partitioned with an empty filesystem.
  45 rm -rf cow.d
  46 mkdir cow.d
  47 cleanup_fn rm -rf cow.d
  48 nbdkit -fv -U - linuxdisk cow.d size=100M \
  49        --run 'qemu-img convert $nbd cow-base.img'
  50 lastmod="$(stat -c "%y" cow-base.img)"
  51
  52 # Run nbdkit with a COW overlay.
  53 start_nbdkit -P cow.pid -U $sock --filter=cow file cow-base.img
  54
  55 # Write some data into the overlay.
  56 guestfish --format=raw -a "nbd://?socket=$sock" -m /dev/sda1 <<EOF
  57   fill-pattern "abcde" 128K /large
  58   write /hello "hello, world"
  59 EOF
  60
  61 # The original file must not be modified.
  62 currmod="$(stat -c "%y" cow-base.img)"
  63
  64 if [ "$lastmod" != "$currmod" ]; then
  65     echo "$0: FAILED last modified time of base file changed"
  66     exit 1
  67 fi
  68
  69 # If we have qemu-img, try the hairy rebase operation documented
  70 # in the nbdkit-cow-filter manual.
  71 if qemu-img --version >/dev/null 2>&1; then
  72     qemu-img create -f qcow2 -b nbd:unix:$sock cow-diff.qcow2
  73     time qemu-img rebase -b cow-base.img cow-diff.qcow2
  74     qemu-img info cow-diff.qcow2
  75
  76     # This checks the file we created exists.
  77     guestfish --ro -a cow-diff.qcow2 -m /dev/sda1 cat /hello
  78 fi