[btrfs-devel][patch]fix for btrfs_truncate_in_trans

[David Chinner]

On Tue, Sep 18, 2007 at 04:22:33PM +0200, Christoph Hellwig wrote:
> On Tue, Sep 18, 2007 at 10:13:13AM -0400, Chris Mason wrote:
> > try_release_extent_mapping should also be changed not to drop things
> > from the extent mapping tree if they are EXTENT_MAP_DELALLOC.
> 
> What XFS does here and what I plan to port over to the extent_map
> code is that ->releasepage will start the delalloc conversion so that
> the page is a simple dirty page and we can drop it, but not actually
> start I/O.

Christoph, do we really need to do the delalloc conversion in
->releasepage in XFS? xfs_bunmapi() correctly handles the
truncation of delalloc extents so any truncate that comes
through xfs_setattr() should work just fine without needed
to do delalloc conversion first....

Or is there some other reason it's done that I'm missing
(after only half a cup of coffee)?

Cheers,

Dave.
-- 
Dave Chinner
Principal Engineer
SGI Australian Software Group