Index: root/xen-unstable.hg/tools/examples/locking.sh =================================================================== --- /dev/null +++ root/xen-unstable.hg/tools/examples/locking.sh @@ -0,0 +1,98 @@ +# +# Copyright (c) 2005 XenSource Ltd. +# +# This library is free software; you can redistribute it and/or +# modify it under the terms of version 2.1 of the GNU Lesser General Public +# License as published by the Free Software Foundation. +# +# This library 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. +# +# You should have received a copy of the GNU Lesser General Public +# License along with this library; if not, write to the Free Software +# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA +# + +# +# Serialisation +# + +LOCK_SLEEPTIME=1 +LOCK_SPINNING_RETRIES=5 +LOCK_RETRIES=10 +LOCK_BASEDIR=/var/run/xen-hotplug + + +claim_lock() +{ + local lockdir="$LOCK_BASEDIR/$1" + mkdir -p "$LOCK_BASEDIR" + _claim_lock "$lockdir" +} + + +release_lock() +{ + _release_lock "$LOCK_BASEDIR/$1" +} + + +_claim_lock() +{ + local lockdir="$1" + local owner=$(_lock_owner "$lockdir") + local retries=0 + + while [ $retries -lt $LOCK_RETRIES ] + do + mkdir "$lockdir" 2>/dev/null && trap "release_lock $1; sigerr" ERR && + _update_lock_info "$lockdir" && return + + local new_owner=$(_lock_owner "$lockdir") + if [ "$new_owner" != "$owner" ] + then + owner="$new_owner" + retries=0 + fi + + if [ $retries -gt $LOCK_SPINNING_RETRIES ] + then + sleep $LOCK_SLEEPTIME + else + sleep 0 + fi + retries=$(($retries + 1)) + done + _steal_lock "$lockdir" +} + + +_release_lock() +{ + trap sigerr ERR + rm -rf "$1" 2>/dev/null || true +} + + +_steal_lock() +{ + local lockdir="$1" + local owner=$(cat "$lockdir/owner" 2>/dev/null || echo "unknown") + log err "Forced to steal lock on $lockdir from $owner!" + _release_lock "$lockdir" + _claim_lock "$lockdir" +} + + +_lock_owner() +{ + cat "$1/owner" 2>/dev/null || echo "unknown" +} + + +_update_lock_info() +{ + echo "$$: $0" >"$1/owner" +} Index: root/xen-unstable.hg/tools/examples/xen-hotplug-common.sh =================================================================== --- root.orig/xen-unstable.hg/tools/examples/xen-hotplug-common.sh +++ root/xen-unstable.hg/tools/examples/xen-hotplug-common.sh @@ -17,7 +17,9 @@ dir=$(dirname "$0") +. "$dir/logging.sh" . "$dir/xen-script-common.sh" +. "$dir/locking.sh" exec 2>>/var/log/xen-hotplug.log @@ -25,12 +27,6 @@ export PATH="/sbin:/bin:/usr/bin:/usr/sb export LANG="POSIX" unset $(set | grep ^LC_ | cut -d= -f1) -log() { - local level="$1" - shift - logger -p "daemon.$level" -- "$0:" "$@" || echo "$0 $@" >&2 -} - fatal() { xenstore_write "$XENBUS_PATH"/hotplug-status error log err "$@" @@ -93,87 +89,4 @@ xenstore_write() { } -# -# Serialisation -# - -LOCK_SLEEPTIME=1 -LOCK_SPINNING_RETRIES=5 -LOCK_RETRIES=10 -LOCK_BASEDIR=/var/run/xen-hotplug - - -claim_lock() -{ - local lockdir="$LOCK_BASEDIR/$1" - mkdir -p "$LOCK_BASEDIR" - _claim_lock "$lockdir" -} - - -release_lock() -{ - _release_lock "$LOCK_BASEDIR/$1" -} - - -_claim_lock() -{ - local lockdir="$1" - local owner=$(_lock_owner "$lockdir") - local retries=0 - - while [ $retries -lt $LOCK_RETRIES ] - do - mkdir "$lockdir" 2>/dev/null && trap "release_lock $1; sigerr" ERR && - _update_lock_info "$lockdir" && return - - local new_owner=$(_lock_owner "$lockdir") - if [ "$new_owner" != "$owner" ] - then - owner="$new_owner" - retries=0 - fi - - if [ $retries -gt $LOCK_SPINNING_RETRIES ] - then - sleep $LOCK_SLEEPTIME - else - sleep 0 - fi - retries=$(($retries + 1)) - done - _steal_lock "$lockdir" -} - - -_release_lock() -{ - trap sigerr ERR - rm -rf "$1" 2>/dev/null || true -} - - -_steal_lock() -{ - local lockdir="$1" - local owner=$(cat "$lockdir/owner" 2>/dev/null || echo "unknown") - log err "Forced to steal lock on $lockdir from $owner!" - _release_lock "$lockdir" - _claim_lock "$lockdir" -} - - -_lock_owner() -{ - cat "$1/owner" 2>/dev/null || echo "unknown" -} - - -_update_lock_info() -{ - echo "$$: $0" >"$1/owner" -} - - log debug "$@" "XENBUS_PATH=$XENBUS_PATH" Index: root/xen-unstable.hg/tools/examples/Makefile =================================================================== --- root.orig/xen-unstable.hg/tools/examples/Makefile +++ root/xen-unstable.hg/tools/examples/Makefile @@ -27,7 +27,7 @@ XEN_SCRIPTS += network-nat vif-nat XEN_SCRIPTS += block XEN_SCRIPTS += block-enbd block-nbd XEN_SCRIPTS += vtpm -XEN_SCRIPT_DATA = xen-script-common.sh +XEN_SCRIPT_DATA = xen-script-common.sh locking.sh logging.sh XEN_SCRIPT_DATA += xen-hotplug-common.sh xen-network-common.sh vif-common.sh XEN_SCRIPT_DATA += block-common.sh vtpm-common.sh Index: root/xen-unstable.hg/tools/examples/logging.sh =================================================================== --- /dev/null +++ root/xen-unstable.hg/tools/examples/logging.sh @@ -0,0 +1,22 @@ +# +# Copyright (c) 2005 XenSource Ltd. +# +# This library is free software; you can redistribute it and/or +# modify it under the terms of version 2.1 of the GNU Lesser General Public +# License as published by the Free Software Foundation. +# +# This library 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. +# +# You should have received a copy of the GNU Lesser General Public +# License along with this library; if not, write to the Free Software +# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA +# + +log() { + local level="$1" + shift + logger -p "daemon.$level" -- "$0:" "$@" || echo "$0 $@" >&2 +}