Re: [PATCH] fs: push file_update_time into ->page_mkwrite

[Dave Chinner <david@fromorbit.com>]

On Tue, Nov 29, 2011 at 04:50:20PM +0100, Jan Kara wrote:
> On Tue 29-11-11 10:40:59, Josef Bacik wrote:
> > The fault code has been calling file_update_time after ->page_mkwrite after it
> > drops the page lock, but this is annoying because this calls mark_inode_dirty
> > which can fail in Btrfs, so we want to be able to do these updates in
> > ->page_mkwrite so we can get an error back to the user.  So get rid of the
> > file_update_time calls in the fault code and push it into everybody who has a
> > ->page_mkwrite.  I didn't do this for ubifs because it appears that ubifs
> > already updates the time itself in ->page_mkwrite, presumebly for the same
> > reasons as btrfs, so I left it as is.  Thanks,
>   But this effectively disables atime updates on mmaped writes for ext2,
> ext3, and similar filesystems which is a no-go IMHO.

Only because it requires all filesystems to implement ->page_mkwrite
to maintain existing functionality.  .  The alternative is to say
that if the filesystem implements the page-mkwrite method it must
update the file times in that call, and then change the generic
fault code to only update the file times if the filesystem doesn't
implement page_mkwrite...

Cheers,

Dave.
-- 
Dave Chinner
david@fromorbit.com