From: Mikulas Patocka Send barrier requests when updating the exception area. Exception area updates need to be ordered w.r.t. data writes, so that the writes are not reordered in hardware disk cache. Signed-off-by: Mikulas Patocka Signed-off-by: Alasdair G Kergon --- drivers/md/dm-snap-persistent.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) Index: linux-2.6.30/drivers/md/dm-snap-persistent.c =================================================================== --- linux-2.6.30.orig/drivers/md/dm-snap-persistent.c +++ linux-2.6.30/drivers/md/dm-snap-persistent.c @@ -636,7 +636,7 @@ static void persistent_commit_exception( /* * Commit exceptions to disk. */ - if (ps->valid && area_io(ps, WRITE)) + if (ps->valid && area_io(ps, WRITE_BARRIER)) ps->valid = 0; /*