When calling saLckResourceClose, we must remove that resource from the
cleanup list for the process calling saLckResourceClose. Without this,
it is possible that when the process exits and calls lck_lib_exit_fn,
the resource will have its reference count decremented again. This can
result in a resource not being removed correctly, since reference
count would be corrupt and would fail the the check we make before
removing a resource.
Once the details of the problem (and test case) are sorted out, the
fix is obvious: remove the resource from the cleanup list for every
close.
Thanks for Honza for finding this and Steve for his help diagnosing
the problem.
Ryan
Index: services/lck.c
===================================================================
--- services/lck.c (revision 2025)
+++ services/lck.c (working copy)
@@ -1593,6 +1593,28 @@
return (0);
}
+static struct resource_cleanup *lck_resource_cleanup_find (
+ void *conn,
+ const mar_name_t *resource_name)
+{
+ struct lck_pd *lck_pd = (struct lck_pd *)api->ipc_private_data_get
(conn);
+
+ struct resource_cleanup *cleanup;
+ struct list_head *cleanup_list;
+
+ for (cleanup_list = lck_pd->resource_cleanup_list.next;
+ cleanup_list != &lck_pd->resource_cleanup_list;
+ cleanup_list = cleanup_list->next)
+ {
+ cleanup = list_entry (cleanup_list, struct resource_cleanup,
cleanup_list);
+
+ if (mar_name_match (resource_name, &cleanup->resource_name)) {
+ return (cleanup);
+ }
+ }
+ return (0);
+}
+
static void lck_resourcelock_response_send (
struct resource_lock *resource_lock,
SaAisErrorT error)
@@ -2240,6 +2262,7 @@
SaAisErrorT error = SA_AIS_OK;
struct resource *resource = NULL;
+ struct resource_cleanup *cleanup = NULL;
/* DEBUG */
log_printf (LOGSYS_LEVEL_DEBUG, "EXEC request: saLckResourceClose\n");
@@ -2259,6 +2282,10 @@
req_exec_lck_resourceclose->exit_flag,
&req_exec_lck_resourceclose->source);
+ /*
+ * If reference count is zero and there are no granted locks,
+ * we can remove this resource.
+ */
if ((resource->refcount == 0) &&
(resource->ex_lock_granted == NULL) &&
(list_empty (&resource->pr_lock_granted_list_head)))
@@ -2267,6 +2294,18 @@
free (resource);
}
+ /*
+ * Remove the cleanup entry for this resource.
+ */
+ cleanup = lck_resource_cleanup_find (
+ req_exec_lck_resourceclose->source.conn,
+ &req_exec_lck_resourceclose->resource_name);
+
+ assert (cleanup != NULL);
+
+ list_del (&cleanup->cleanup_list);
+ free (cleanup);
+
error_exit:
if (api->ipc_source_is_local (&req_exec_lck_resourceclose->source))
{
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