Re: Ext4 devel interlock meeting minutes (October 1, 2007)

[Eric Sandeen <sandeen@redhat.com>]

Andreas Dilger wrote:
> On Oct 01, 2007  15:10 -0700, Avantika Mathur wrote:
>> Delayed Allocation:
>> - There has been an lkml thread about these patches.
>> - We have and approach that works for ext4, implemented at the vfs 
>> level, but unless we can prove it can work for other filesystems, it 
>> will not be accepted.  
>> - Christoph Hellwig has commented that these patches will not work for 
>> XFS.  
> 
> Hmm, but I thought that Christoph also agreed that it would be OK to
> get the ext4 delalloc code merged separately, so long as it doesn't
> need big/any changes to the VFS to implement it.  It might be that the
> ext4 and XFS code is different enough that they cannot share the
> delayed allocation code.

IIRC there is only one change to the VFS, a test for buffer_delay() in
__block_write_full_page().  XFS is the only current caller of
set_buffer_delay, and XFS does not even use the block_write_full_page path.

The rest was a huge chunk dropped into mpage.c, but not interfering with
anything else.

So, I don't see any conflict.

-Eric