tree bdb0f5783e821edb482247c161692ba9528aa060
parent 21b568350861a2c6eedfef95b70f88faf2fbd32a
author Charlie Shepherd <charlie@ctshepherd.com> 1384541221 +0100
committer Kevin Wolf <kwolf@redhat.com> 1385728836 +0100

COW: Speed up writes

Process a whole sector's worth of COW bits by reading a sector, setting
the bits after skipping any already set bits, then writing it out again.
Make sure we only flush once before writing metadata, and only if we
need to write metadata.

Signed-off-by: Charlie Shepherd <charlie@ctshepherd.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>