vfs: mnt_drop_write_file()

new helper (wrapper around mnt_drop_write()) to be used in pair with
mnt_want_write_file().

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 6 insertions, 0 deletions

diff --git a/fs/namespace.c b/fs/namespace.c
index 7a8f949cec1b..86b4f6406470 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -392,6 +392,12 @@ void mnt_drop_write(struct vfsmount *mnt)
 }
 EXPORT_SYMBOL_GPL(mnt_drop_write);
 
+void mnt_drop_write_file(struct file *file)
+{
+	mnt_drop_write(file->f_path.mnt);
+}
+EXPORT_SYMBOL(mnt_drop_write_file);
+
 static int mnt_make_readonly(struct vfsmount *mnt)
 {
 	int ret = 0;