Modify to assume transactions

Signed-off-by: Rusty Russel <rusty@rustcorp.com.au>
Signed-off-by: Christian Limpach <Christian.Limpach@cl.cam.ac.uk>

diff --git a/linux-2.6-xen-sparse/drivers/xen/xenbus/xenbus_probe.c b/linux-2.6-xen-sparse/drivers/xen/xenbus/xenbus_probe.c
index f6f29bfaf05684f5a7d3a171882cbc2bac95b2b6..6a4126fdd1e5b4782f2b557dcb6fd3fb52d7a02c 100644 (file)
--- a/linux-2.6-xen-sparse/drivers/xen/xenbus/xenbus_probe.c
+++ b/linux-2.6-xen-sparse/drivers/xen/xenbus/xenbus_probe.c
@@ -220,8 +220,16 @@ unlock:
        return err;
 }
 
-/* FIXME: When all tools use transactions, we can ignore events on
- * subpaths. */
+static unsigned int char_count(const char *str, char c)
+{
+       unsigned int i, ret = 0;
+
+       for (i = 0; str[i]; i++)
+               if (str[i] == c)
+                       ret++;
+       return ret;
+}
+
 static void dev_changed(struct xenbus_watch *watch, const char *node)
 {
        char busid[BUS_ID_SIZE];
@@ -231,28 +239,26 @@ static void dev_changed(struct xenbus_watch *watch, const char *node)
        char *type;
 
        /* Node is of form device/<type>/<identifier>[/...] */
-       type = strchr(node, '/');
-       if (!type)
+       if (char_count(node, '/') != 3)
                return;
-       type++;
 
+       type = strchr(node, '/');
+       type++;
        typelen = strcspn(type, "/");
-       if (!typelen)
-               return;
        idlen = strcspn(type + typelen + 1, "/");
-       if (!idlen)
-               return;
        if (typelen + strlen("-") + idlen + 1 > BUS_ID_SIZE) {
                printk("Device for node %s is too big!\n", node);
                return;
        }
 
+       /* Does it exist? */
+       exists = xenbus_exists(node, "");
+
        /* Create it with a / so we can see if it exists. */
-       sprintf(busid, "%.*s/%.*s", typelen, type, idlen, type + typelen + 1);
-       exists = xenbus_exists("device", busid);
-       busid[typelen] = '-';
+       sprintf(busid, "%.*s-%.*s", typelen, type, idlen, type + typelen + 1);
 
        dev = xenbus_device_find(busid);
+       printk("xenbus: device %s %s\n", busid, dev ? "exists" : "new");
        if (dev && !exists) {
                printk("xenbus: Unregistering device %s\n", busid);
                /* FIXME: free? */