Re: [PATCH 1/4] fs: split update_time() into update_time() and write_time()

[Theodore Ts'o <tytso@xxxxxxx>]

On Mon, Nov 24, 2014 at 05:38:30PM +0100, David Sterba wrote:
> 
> It is necessary and the whole .update_time callback was added
> intentionally, see commits
> 
> c3b2da314834499f34cba94f7053e55f6d6f92d8
> fs: introduce inode operation ->update_time
> 
> e41f941a23115e84a8550b3d901a13a14b2edc2f
> Btrfs: move over to use ->update_time

Being able to signal an error if the time update fails is still
possible even if we drop update_time(), because the new write_time()
function will return an error.

> 2bc5565286121d2a77ccd728eb3484dff2035b58
> Btrfs: don't update atime on RO subvolumes

Yes, but this doesn't answer my question about other places where the
VFS is only checking MS_RDONLY and MNT_READONLY besides just
update_atime().  Maybe we should be exposing an "is_readonly(inode)"
inode operations function to address this?

                                                - Ted