1 files changed, 43 insertions, 0 deletions
diff --git a/fs/cachefiles/namei.c b/fs/cachefiles/namei.c
new file mode 100644
index 000000000000..913f83f1c900
--- /dev/null
+++ b/fs/cachefiles/namei.c
@@ -0,0 +1,43 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* CacheFiles path walking and related routines
+ *
+ * Copyright (C) 2021 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#include <linux/fs.h>
+#include "internal.h"
+
+/*
+ * Mark the backing file as being a cache file if it's not already in use.  The
+ * mark tells the culling request command that it's not allowed to cull the
+ * file or directory.  The caller must hold the inode lock.
+ */
+static bool __cachefiles_mark_inode_in_use(struct cachefiles_object *object,
+					   struct dentry *dentry)
+{
+	struct inode *inode = d_backing_inode(dentry);
+	bool can_use = false;
+
+	if (!(inode->i_flags & S_KERNEL_FILE)) {
+		inode->i_flags |= S_KERNEL_FILE;
+		trace_cachefiles_mark_active(object, inode);
+		can_use = true;
+	} else {
+		pr_notice("cachefiles: Inode already in use: %pd\n", dentry);
+	}
+
+	return can_use;
+}
+
+/*
+ * Unmark a backing inode.  The caller must hold the inode lock.
+ */
+static void __cachefiles_unmark_inode_in_use(struct cachefiles_object *object,
+					     struct dentry *dentry)
+{
+	struct inode *inode = d_backing_inode(dentry);
+
+	inode->i_flags &= ~S_KERNEL_FILE;
+	trace_cachefiles_mark_inactive(object, inode);
+}