[PATCH v3 4/8] tools/init-dom0less: Switch domain_exists to check xenstore name

[Jason Andryuk <jason.andryuk@amd.com>]

Previously, the xenstore "introduced" state was used to avoid running
init-dom0less twice on the same domain.  With xenstored
auto-introduction, that can no longer be used.  Instead check of the
domain's name has been set and use that to determine whether or not to
bail out.

Signed-off-by: Jason Andryuk <jason.andryuk@amd.com>
---
v3:
Move xenstore reading into domain_exists()
Reorder
---
 tools/helpers/init-dom0less.c | 21 ++++++++++++++++++++-
 1 file changed, 20 insertions(+), 1 deletion(-)

diff --git a/tools/helpers/init-dom0less.c b/tools/helpers/init-dom0less.c
index 3906c4b61a..eb793c7aab 100644
--- a/tools/helpers/init-dom0less.c
+++ b/tools/helpers/init-dom0less.c
@@ -60,6 +60,19 @@ static int get_xs_page(libxl_dominfo *info, uint64_t *xenstore_pfn)
     return 0;
 }
 
+static char *do_xs_read_dom(struct xs_handle *xsh, xs_transaction_t t,
+                            domid_t domid, char *path)
+{
+    char full_path[STR_MAX_LENGTH];
+    int rc;
+
+    rc = snprintf(full_path, STR_MAX_LENGTH,
+                  "/local/domain/%u/%s", domid, path);
+    if (rc < 0 || rc >= STR_MAX_LENGTH)
+        return NULL;
+    return xs_read(xsh, t, full_path, NULL);
+}
+
 static bool do_xs_write_dom(struct xs_handle *xsh, xs_transaction_t t,
                             domid_t domid, char *path, char *val)
 {
@@ -332,7 +345,13 @@ static int init_domain(libxl_dominfo *info)
 /* Check if domain has been configured in XS */
 static bool domain_exists(int domid)
 {
-    return xs_is_domain_introduced(xsh, domid);
+    char *name = do_xs_read_dom(xsh, XBT_NULL, domid, "name");
+    if (name) {
+        free(name);
+        return true;
+    }
+
+    return false;
 }
 
 int main(int argc, char **argv)
-- 
2.50.1