Re: [PATCH-v4 1/7] vfs: split update_time() into update_time() and write_time()

[Jan Kara <jack@xxxxxxx>]

On Wed 26-11-14 11:23:28, Christoph Hellwig wrote:
> As mentioned last round please move the addition of the is_readonly
> operation to the first thing in the series, so that the ordering makes
> more sense.
> 
> Second I think this patch is incorrect for XFS - XFS uses ->update_time
> to set the time stampst in the dinode.  These two need to be coherent
> as we can write out a dirty inode any time, so it needs to have the
> timestamp uptodate.
  But Ted changed XFS to copy timestamps to on-disk structure from the
in-memory inode fields after VFS updated the timestamps. So the stamps
should be coherent AFAICT, shouldn't they?

> Third update_time now calls mark_inode_dirty unconditionally, while
> previously it wasn't called when ->update_time was set.  At least
> for XFS that's a major change in behavior as XFS never used VFS dirty
> tracking for metadata updates.
  We don't call mark_inode_dirty() when ->write_time is set (note the
return, I missed it on the first reading) which looks sensible to me.

                                                                Honza
-- 
Jan Kara <jack@xxxxxxx>
SUSE Labs, CR