Add a mechanism to detect block device setup failure

PATCH In review Murillo Fernandes Bernardes 2 participants 2 messages Oct 29, 2005 – Oct 31, 2005

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Murillo Fernandes Bernardes

author

2005-10-29 03:11 UTC #0 lore raw

PATCH 1/1 Add a mechanism to detect block device setup failure

The problem is: There is no mechanism to detect block device setup failure

Network devices have the same problem, and are fixed with this too.

I handling this problem in the way suggested by aliguori:
- hotplug scripts write a "hotplug-status" node on store
- Xend DevController.createDevice() check verify this node and return success or throw an exception on failure.
- If no changes in "hotplug-status" node after DEVICE_CREATE_TIMEOUT seconds Xend throw an exception showing the problem with hotplug scripts.

Comments?

Regards

Signature · 1 line

Murillo Fernandes Bernardes

tools/examples/block-common.sh +8 -1

diff -r 20d1a79ebe31 tools/examples/block-common.sh
@@ -42,10 +42,17 @@
   local major
   local minor
   local pdev
-	
+
   major=$(stat -L -c %t "$1")
   minor=$(stat -L -c %T "$1")
+  
+  if [ -z $major  -o -z $minor ]; then
+    fatal "Backend device does not exist"
+  fi
+  
   pdev=$(printf "0x%02x%02x" "0x$major" "0x$minor")
   xenstore_write "$XENBUS_PATH"/physical-device "$pdev" \
                  "$XENBUS_PATH"/node "$1"
+		 
+  success
 }

tools/examples/vif-bridge +2 -0

diff -r 20d1a79ebe31 tools/examples/vif-bridge
@@ -45,6 +45,7 @@
           fatal "brctl addif $bridge $vif failed"
 
         ifconfig "$vif" up || fatal "ifconfig $vif up failed"
+        success
         ;;
     down)
         # vifs are auto-removed from bridge.

@@ -55,3 +56,4 @@
 handle_iptable
 
 log debug "vif-bridge operation for $vif successful."
+

tools/examples/vif-nat +2 -0

diff -r 20d1a79ebe31 tools/examples/vif-nat
@@ -54,3 +54,5 @@
 ip r ${ipcmd} ${ip} dev ${vif} src ${main_ip}
 
 handle_iptable()
+
+success

tools/examples/vif-route +2 -0

diff -r 20d1a79ebe31 tools/examples/vif-route
@@ -46,3 +46,5 @@
 fi
 
 handle_iptable()
+
+success

tools/examples/xen-hotplug-common.sh +6 -0

diff -r 20d1a79ebe31 tools/examples/xen-hotplug-common.sh
@@ -29,8 +29,14 @@
 }
 
 fatal() {
+  xenstore_write "$XENBUS_PATH"/hotplug-status error
   log err "$@"
   exit 1
+}
+
+success() {
+  # Tell DevController that backend is "connected"
+  xenstore_write "$XENBUS_PATH"/hotplug-status connected
 }
 
 xenstore_read() {

tools/python/xen/xend/server/DevController.py +43 -1

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Ewan Mellor

2005-10-31 16:16 UTC #1 lore raw

Quoted 4 lines · Murillo Fernandes Bernardes

The problem is: There is no mechanism to detect block device setup failure
Network devices have the same problem, and are fixed with this too.

Quoted 8 lines

I handling this problem in the way suggested by aliguori:
- hotplug scripts write a "hotplug-status" node on store
- Xend DevController.createDevice() check verify this node and return success or throw an exception on failure.
- If no changes in "hotplug-status" node after DEVICE_CREATE_TIMEOUT seconds Xend throw an exception showing the problem with hotplug scripts.
Comments?

Thanks a lot for this, Murillo. I have a concern that this patch only protects us against failure of hotplugging, and not, for example, a failure of the backend driver, but it's certainly a good step in the right direction, so I've applied it. I'll be working myself in this area over the next day or two to improve this further.

Thanks again,

Ewan.