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xen/tools/hotplug/Linux/block-dummy
T
George Dunlap 5806acf503 tools/hotplug: Add a "dummy" hotplug script for testing
Testing the hotplug external script path at the moment involves
actually setting up one of the alternate datapaths (blktap, iscsi,
&c).  Simplify testing by making a script which does a simple loopback,
but still has a target that can't be used directly.

To use:

script=block-dummy,vdev=xvda,target=dummy:<file>

Signed-off-by: George Dunlap <george.dunlap@eu.citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Tested-by: George Dunlap <george.dunlap@citrix.com>
2016-04-04 17:47:39 +01:00

108 lines
2.4 KiB
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#!/bin/bash -e
#
# dummy Xen block device hotplug script
#
# Author George Dunlap <george.dunlap@eu.citrix.com>
#
# Based on block-iscsi by Roger Pau Monné <roger.pau@citrix.com>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License as published
# by the Free Software Foundation; version 2.1 only. with the special
# exception on linking described in file LICENSE.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU Lesser General Public License for more details.
#
# Usage:
#
# Target should be specified using the following syntax:
#
# script=block-dummy,vdev=xvda,target=dummy:<file>
dir=$(dirname "$0")
. "$dir/block-common.sh"
check_tools()
{
if ! command -v losetup > /dev/null 2>&1; then
fatal "Unable to find losetup"
fi
}
# Sets the following global variables based on the params field passed in as
# a parameter: type file
parse_target()
{
params=($(echo "$1" | tr ":" "\n"))
type=${params[0]}
file=${params[1]}
if [ -z "$type" ] || [ -z "$file" ]; then
fatal "Cannot parse required parameters"
fi
if [ "$type" != "dummy" ] ; then
fatal "Invalid type: $type"
fi
}
# Attaches the device and writes xenstore backend entries to connect
# the device
add()
{
test -f "$file" || fatal "$file does not exist."
loopdev=$(losetup -f 2>/dev/null || find_free_loopback_dev)
if [ "$loopdev" = '' ]
then
fatal 'Failed to find an unused loop device'
fi
if LANG=C losetup -h 2>&1 | grep read-only >/dev/null
then
roflag="-$mode"; roflag="${roflag#-w}"; roflag="${roflag#-!}"
else
roflag=''
fi
do_or_die losetup $roflag "$loopdev" "$file"
# FIXME Is this OK?
xenstore_write "$XENBUS_PATH/node" "$loopdev"
write_dev "$loopdev"
}
# Disconnects the device
remove()
{
node=$(xenstore_read "$XENBUS_PATH/node")
losetup -d "$node"
}
command=$1
target=$(xenstore-read $XENBUS_PATH/params || true)
if [ -z "$target" ]; then
fatal "No information about the target"
fi
parse_target "$target"
mode=$(xenstore_read "$XENBUS_PATH/mode")
mode=$(canonicalise_mode "$mode")
check_tools || exit 1
case $command in
add)
add
;;
remove)
remove
;;
*)
exit 1
;;
esac