[T106][ZXW-22]7520V3SCV2.01.01.02P42U09_VEC_V0.8_AP_VEC origin source commit
Change-Id: Ic6e05d89ecd62fc34f82b23dcf306c93764aec4b
diff --git a/ap/os/linux/linux-3.4.x/ipc/ipcns_notifier.c b/ap/os/linux/linux-3.4.x/ipc/ipcns_notifier.c
new file mode 100644
index 0000000..b9b31a4
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/ipc/ipcns_notifier.c
@@ -0,0 +1,92 @@
+/*
+ * linux/ipc/ipcns_notifier.c
+ * Copyright (C) 2007 BULL SA. Nadia Derbey
+ *
+ * Notification mechanism for ipc namespaces:
+ * The callback routine registered in the memory chain invokes the ipcns
+ * notifier chain with the IPCNS_MEMCHANGED event.
+ * Each callback routine registered in the ipcns namespace recomputes msgmni
+ * for the owning namespace.
+ */
+
+#include <linux/msg.h>
+#include <linux/rcupdate.h>
+#include <linux/notifier.h>
+#include <linux/nsproxy.h>
+#include <linux/ipc_namespace.h>
+
+#include "util.h"
+
+
+
+static BLOCKING_NOTIFIER_HEAD(ipcns_chain);
+
+
+static int ipcns_callback(struct notifier_block *self,
+ unsigned long action, void *arg)
+{
+ struct ipc_namespace *ns;
+
+ switch (action) {
+ case IPCNS_MEMCHANGED: /* amount of lowmem has changed */
+ case IPCNS_CREATED:
+ case IPCNS_REMOVED:
+ /*
+ * It's time to recompute msgmni
+ */
+ ns = container_of(self, struct ipc_namespace, ipcns_nb);
+ /*
+ * No need to get a reference on the ns: the 1st job of
+ * free_ipc_ns() is to unregister the callback routine.
+ * blocking_notifier_chain_unregister takes the wr lock to do
+ * it.
+ * When this callback routine is called the rd lock is held by
+ * blocking_notifier_call_chain.
+ * So the ipc ns cannot be freed while we are here.
+ */
+ recompute_msgmni(ns);
+ break;
+ default:
+ break;
+ }
+
+ return NOTIFY_OK;
+}
+
+int register_ipcns_notifier(struct ipc_namespace *ns)
+{
+ int rc;
+
+ memset(&ns->ipcns_nb, 0, sizeof(ns->ipcns_nb));
+ ns->ipcns_nb.notifier_call = ipcns_callback;
+ ns->ipcns_nb.priority = IPCNS_CALLBACK_PRI;
+ rc = blocking_notifier_chain_register(&ipcns_chain, &ns->ipcns_nb);
+ if (!rc)
+ ns->auto_msgmni = 1;
+ return rc;
+}
+
+int cond_register_ipcns_notifier(struct ipc_namespace *ns)
+{
+ int rc;
+
+ memset(&ns->ipcns_nb, 0, sizeof(ns->ipcns_nb));
+ ns->ipcns_nb.notifier_call = ipcns_callback;
+ ns->ipcns_nb.priority = IPCNS_CALLBACK_PRI;
+ rc = blocking_notifier_chain_cond_register(&ipcns_chain,
+ &ns->ipcns_nb);
+ if (!rc)
+ ns->auto_msgmni = 1;
+ return rc;
+}
+
+void unregister_ipcns_notifier(struct ipc_namespace *ns)
+{
+ blocking_notifier_chain_unregister(&ipcns_chain, &ns->ipcns_nb);
+ ns->auto_msgmni = 0;
+}
+
+int ipcns_notify(unsigned long val)
+{
+ return blocking_notifier_call_chain(&ipcns_chain, val, NULL);
+}