Commit 935a074f authored May 11, 2018 by Vivek Goyal Committed by Miklos Szeredi Jul 20, 2018

ovl: Do not do metacopy only for ioctl modifying file attr



ovl_copy_up() by default will only do metadata only copy up (if enabled).
That means when ovl_real_ioctl() calls ovl_real_file(), it will still get
the lower file (as ovl_real_file() opens data file and not metacopy).  And
that means "chattr +i" will end up modifying lower inode.

There seem to be two ways to solve this.
A. Open metacopy file in ovl_real_ioctl() and do operations on that
B. Force full copy up when FS_IOC_SETFLAGS is called.

I am resorting to option B for now as it feels little safer option.  If
there are performance issues due to this, we can revisit it.

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

parent 997336f2

fs/overlayfs/file.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -372,7 +372,7 @@ static long ovl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
		if (ret)
		return ret;

		ret = ovl_copy_up(file_dentry(file));
		ret = ovl_copy_up_with_data(file_dentry(file));
		if (!ret) {
		ret = ovl_real_ioctl(file, cmd, arg);