1 files changed, 52 insertions, 0 deletions
diff --git a/fs/xfs/xfs_hooks.c b/fs/xfs/xfs_hooks.c
new file mode 100644
index 000000000000..a58d1de2d37d
--- /dev/null
+++ b/fs/xfs/xfs_hooks.c
@@ -0,0 +1,52 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2022-2024 Oracle.  All Rights Reserved.
+ * Author: Darrick J. Wong <djwong@kernel.org>
+ */
+#include "xfs.h"
+#include "xfs_fs.h"
+#include "xfs_shared.h"
+#include "xfs_format.h"
+#include "xfs_trans_resv.h"
+#include "xfs_mount.h"
+#include "xfs_ag.h"
+#include "xfs_trace.h"
+
+/* Initialize a notifier chain. */
+void
+xfs_hooks_init(
+	struct xfs_hooks	*chain)
+{
+	BLOCKING_INIT_NOTIFIER_HEAD(&chain->head);
+}
+
+/* Make it so a function gets called whenever we hit a certain hook point. */
+int
+xfs_hooks_add(
+	struct xfs_hooks	*chain,
+	struct xfs_hook		*hook)
+{
+	ASSERT(hook->nb.notifier_call != NULL);
+	BUILD_BUG_ON(offsetof(struct xfs_hook, nb) != 0);
+
+	return blocking_notifier_chain_register(&chain->head, &hook->nb);
+}
+
+/* Remove a previously installed hook. */
+void
+xfs_hooks_del(
+	struct xfs_hooks	*chain,
+	struct xfs_hook		*hook)
+{
+	blocking_notifier_chain_unregister(&chain->head, &hook->nb);
+}
+
+/* Call a hook.  Returns the NOTIFY_* value returned by the last hook. */
+int
+xfs_hooks_call(
+	struct xfs_hooks	*chain,
+	unsigned long		val,
+	void			*priv)
+{
+	return blocking_notifier_call_chain(&chain->head, val, priv);
+}