I'm a bit worried about one thing ... it looks like XFS and ext4
use different techniques to order data and metadata referencing
them. now I'm not that optimistic that we can separate ordering
from delalloc itself clean and reasonable way. In general, I'd
prefer common code in fs/ (mm/?) of course, for number of reasons.

thanks, Alex


Christoph Hellwig wrote:

I'm a big proponent of having proper common delalloc code, but the
one proposed here is not generic for the existing filesystem using
delalloc.  It's still on my todo list to revamp the xfs code to get
rid of some of the existing mess and make it useable genericly.  If
the ext4 users are fine with the end result we could move to generic
code.

Note that moving to VFS is bullshit either way, writeback code is
nowhere near the VFS nor should it.