simplify some shell code

[invirt/packages/invirt-xen-config.git] / debian / invirt-xen-config.init

diff --git a/debian/invirt-xen-config.init b/debian/invirt-xen-config.init
index 787343d..430ae9e 100755 (executable)
--- a/debian/invirt-xen-config.init
+++ b/debian/invirt-xen-config.init
@@ -11,18 +11,57 @@
 
 PACKAGE=invirt-xen-config
 NAME="$PACKAGE"
-DESC="Startup script for the Invirt Xen host"
+DESC="Invirt Xen host"
 PARENTPACKAGE=xend
-GEN_FILES=/etc/xen/xend-config.sxp.invirt
+SYSVMS=(s_master s_remote s_console)
+GEN_FILES=(/etc/xen/xend-config.sxp.invirt "${SYSVMS[@]/#//etc/xen/sysvms/}")
 
 dpkg -s "$PACKAGE" >/dev/null 2>/dev/null || exit 0
 
 . /lib/init/gen-files.sh
 . /lib/init/std-init.sh
 
+start_sysvm() {
+    # Attempt to start a sysvm, but only if it's not running already
+    # somewhere on the cluster
+    
+    VM="$1"
+    DISK="/dev/xenvg/${VM}_hda"
+    
+    # Don't bother trying to start the VM if it's already running
+    if xm list "$1" >/dev/null 2>&1; then
+        return 1
+    fi
+    
+    if lvchange -a n "$DISK" >/dev/null 2>&1 && lvchange -a ey "$DISK" >/dev/null 2>&1; then
+        # If we can disable and then re-enable the VMs disk, then the
+        # VM can't be running. If the lvchange -a ey succeeds, then we
+        # have an exclusive lock across the cluster on enabling the
+        # disk, which avoids the potential race condition of two hosts
+        # starting a VM at the same time
+        [ "$VERBOSE" != no ] && log_daemon_msg "Starting sysvm $VM"
+        xm create "sysvms/$VM" >/dev/null
+        [ "$VERBOSE" != no ] && log_end_msg $?
+        RET=0
+    else
+        RET=1
+    fi
+    
+    # Regardless of whether we could get the lock or not, the
+    # lvchange -a n probably disabled the LV somewhere; be sure we
+    # clean up
+    lvchange -a y "$DISK" >/dev/null 2>&1
+    
+    return $RET
+}
+
 do_startup() {
     gen_files
     
+    for vm in "${SYSVMS[@]}"; do
+        start_sysvm "$vm"
+    done
+    
     echo 1 >/proc/sys/net/ipv4/ip_forward
     for i in all default; do
         echo 1 >/proc/sys/net/ipv4/conf/$i/rp_filter