tree e33d9a25fc5ec8e03c1f0d5a4775c865e0520811
parent e5bc2458293b2af6c0b94435965c68cc70974b56
author Chris Mason <chris.mason@oracle.com> 1288114845 -0400
committer Chris Mason <chris.mason@oracle.com> 1288365936 -0400

Btrfs: use the flusher threads for delalloc throttling

We have a fairly complex set of loops around walking our list of
delalloc inodes when we find metadata delalloc space running low.
It doesn't work very well, can use large amounts of CPU and doesn't
do very efficient writeback.

This switches us to kick the bdi flusher threads instead.  All dirty
data in btrfs is accounted as delalloc data, so this is very similar
in terms of what it writes, but we're able to just kick off the IO
and wait for progress.

Signed-off-by: Chris Mason <chris.mason@oracle.com>