vfs, cachefiles: Mark a backing file in use with an inode flag

[linux-2.6-microblaze.git] / fs / cachefiles / namei.c

diff --git a/fs/cachefiles/namei.c b/fs/cachefiles/namei.c
new file mode 100644 (file)
index 0000000..913f83f
--- /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);
+}