Merge tag 'efi-next' of git://git.kernel.org/pub/scm/linux/kernel/git/mfleming/efi...

[firefly-linux-kernel-4.4.55.git] / fs / kernfs / dir.c

diff --git a/fs/kernfs/dir.c b/fs/kernfs/dir.c
index 2d48d28e164015668dcc8d04ff72148f07f28e38..91e004518237f78b0e48b58ca1a233b0dc15c75d 100644 (file)
--- a/fs/kernfs/dir.c
+++ b/fs/kernfs/dir.c
@@ -91,6 +91,29 @@ int kernfs_name(struct kernfs_node *kn, char *buf, size_t buflen)
        return ret;
 }
 
+/**
+ * kernfs_path_len - determine the length of the full path of a given node
+ * @kn: kernfs_node of interest
+ *
+ * The returned length doesn't include the space for the terminating '\0'.
+ */
+size_t kernfs_path_len(struct kernfs_node *kn)
+{
+       size_t len = 0;
+       unsigned long flags;
+
+       spin_lock_irqsave(&kernfs_rename_lock, flags);
+
+       do {
+               len += strlen(kn->name) + 1;
+               kn = kn->parent;
+       } while (kn && kn->parent);
+
+       spin_unlock_irqrestore(&kernfs_rename_lock, flags);
+
+       return len;
+}
+
 /**
  * kernfs_path - build full path of a given node
  * @kn: kernfs_node of interest